description stringlengths 2.98k 3.35M | abstract stringlengths 94 10.6k | cpc int64 0 8 |
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CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This Application claims priority as a non-provisional perfection of prior filed U.S. Provisional Application 60/884,617, filed on Jan. 11, 2007 and incorporates the same by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to the field of firearms and more particularly relates to a gunstock and adapters so that the gunstock may be attached to existing rifle platforms.
BACKGROUND OF THE INVENTION
[0003] The present invention is a replacement gunstock for various rifle platforms. It should be noted, that while technically not rifles, the invention may be practiced with other long guns, like shot guns, and the term “rifle” should be read to include any type of personal long gun. Replacement stocks are known in the prior art and are usually made for one particular rifle platform, e.g either the M16/AR15, AK-47, FAL or other existing platforms. However, replacement stocks made for one of these platforms are usually not made for another. As such, adapters are occasionally made to convert one type of stock to fit on another. These adapters typically become a weak point on the rifle or create extra length which makes a rifle more cumbersome. The factor causing these drawbacks is simple, a replacement stock is made and then an adapter is made to accommodate platforms other than the one for which it was created. No replacement stock on the market is made with universal use on rifle platforms in mind.
[0004] The present invention represents a departure from the prior art in that the gunstock of the present invention is actually designed from the onset as being used on all platforms. As such it is specially structured to interface with an adapter which is likewise structured for enhanced strength and adaptability to a given platform. The resultant gunstock is therefore stronger, has a better interface with the platform and more ergonomically desirable than replacement gunstocks on the market.
SUMMARY OF THE INVENTION
[0005] In view of the foregoing disadvantages inherent in the known types of gunstocks, this invention provides a gunstock designed to be adaptable to any platform without sacrificing strength and ergonomics. As such, the present invention's general purpose is to provide a new and improved gunstock that is adaptable for use on any rifle platform.
[0006] To accomplish these objectives, the gunstock comprises a stock body component of any design desired but also having a uniform structured interface for cooperation with an adapter. The invention also comprises an adapter which cooperates with the stock body's interface and presents the stock interface for a given rifle platform. The structure of the adapter and stock component are such that they cooperatively strengthen each other in use, and not merely serve as a means of attaching the stock to a given rifle. As such the ergonomic and durability features of the gunstock as a whole are superior to those found in the prior art.
[0007] The more important features of the invention have thus been outlined in order that the more detailed description that follows may be better understood and in order that the present contribution to the art may better be appreciated. Additional features of the invention will be described hereinafter and will form the subject matter of the claims that follow.
[0008] Many objects of this invention will appear from the following description and appended claims, reference being made to the accompanying drawings forming a part of this specification wherein like reference characters designate corresponding parts in the several views.
[0009] Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.
[0010] As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a perspective view of a gunstock according to the present invention with an adapter for a G3 style rifle.
[0012] FIG. 2 is a right plan view of the gunstock of FIG. 1 .
[0013] FIG. 3 is a left plan view of the gunstock of FIG. 1 .
[0014] FIG. 4 is a rear plan view of the gunstock of FIG. 1 .
[0015] FIG. 5 is a front plan view of the gunstock of FIG. 1 .
[0016] FIG. 6 is a cross-sectional view, taken along line 6 - 6 of FIG. 4 , of the gunstock of FIG. 1 .
[0017] FIG. 7 is a perspective view of just the stock component of the gunstock of FIG. 1 .
[0018] FIG. 8 is a perspective view of the adapter shown in FIG. 1 .
[0019] FIG. 9 is a front plan view of the adapter of FIG. 8 .
[0020] FIG. 10 is a rear plan view of the adapter of FIG. 8 .
[0021] FIG. 11 is a cross-sectional view, taken along line 11 - 11 in FIG. 9 , of the adapter of FIG. 8 .
[0022] FIG. 12 is a perspective view of the gunstock according to the present invention with an adapter for an AK-47 style rifle.
[0023] FIG. 12 is a perspective view of the gunstock according to the present invention with an adapter for a FAL style rifle.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0024] With reference now to the drawings, the preferred embodiment of the gunstock and the adapters therefore are herein described. It should be noted that the articles “a”, “an” and “the”, as used in this specification, include plural referents unless the content clearly dictates otherwise.
[0025] With reference to FIG. 1 , the whole gunstock system comprises a stock body 10 an adapter 20 and connection means to join them together. In FIG. 1 , the adapter 20 is designed for a G3 style rifle and the stock body 10 is a precision rifle stock, or sniper stock. The type of stock body is, in itself, not relevant to the invention, except that whatever type of stock is chosen, the stock body 10 must have structure to interface with the adapter 20 . The structure of the stock body is shown in greater detail in FIGS. 6 and 7 . Stock body 10 presents the desired features of the chosen stock, in this case adjustable plates 2 , 6 and adjustment dials 4 , 8 and attachment structure. The attachment structure of the stock body 10 includes a spur 16 extending from a forward position of the stock body 10 and interfacing grooves 18 to accommodate the adapter 20 . Pass through holes 15 and a central bore 17 are located on the spur 16 .
[0026] The adapter, shown in FIGS. 7-11 , comprises a central body 24 and two interfacing ends 22 , 26 . Hind end 22 interfaces with the stock body 10 with access to sleeve 28 for the spur 16 and a pair of ear like structures 27 that rest within interfacing grooves 18 of the stock body 10 . Structure for attachment also includes two sets of pass through holes 21 on either ear structure 27 that correspond to stock body pass through holes 15 .
[0027] In assembly, the spur 16 is inserted into the adapter 20 through a sleeve 28 located on a distal side of the adapter's main body 24 ( FIG. 6 ). Ear-like projections 27 then rest in cut out surfaces 18 of the stock body when the adapter 20 and stock body 10 are assembled. The preferred connection means is a pair of bolts 14 driven through the pass-through holes of the adapter 21 and of the stock body 15 ( FIG. 1 ) and bracing at least one pressure plate 12 against the adapter hind section 22 ( FIG. 2 ). Opposite the pressure plate 12 is a fastening means 13 , shown in FIG. 3 . The means depicted are two simple nuts that secure threaded bolt ends. Other possible means are a receiving pressure plate, with threaded bolt holes, or a specialized sling fitting which could provide fastening means. The structures described are usable on either side of the adapter front section 22 , which is particularly useful as pass through bore 17 is designed to accommodate a sling fitting in a switchable manner, that is the user may decide for right or left mounting of the sling fitting, and connection means should be likewise adaptable. Ideally, a detent 25 is provided in the adapter 20 to seat the pressure plate 12 .
[0028] Attachment to the rifle is accomplished in regular means for the rifle's stock. Different rifles will require different adapters. Two examples of such are shown in FIGS. 12 and 13 , which depict adapters for AK and FAL type rifles respectively. The utility of the invention lies in the fact that the stock body 10 is itself common and made specifically to interact with an adapter as a whole stock for a rifle. As such any adapter, including the G3 adapter 20 , the AK adapter 30 , the FAL adapter 40 , or any other desired to be made, will have the same structures at its hind end 22 while the structure at the fore end 26 will vary with the known structure to attach a regular stock for a given rifle style. As such, instead of creating molds or three or more separate stocks, the stock body of the present invention needs only be made from one mold or procedure while each adapter may then be molded as needed for demand. Each adapter's mold is also much less complicated and smaller than a mold for each stock that the present invention is to replace. Other adapters may of course be made for future platforms or other current platforms such as the AR15.
[0029] Although the present invention has been described with reference to preferred embodiments, numerous modifications and variations can be made and still the result will come within the scope of the invention. No limitation with respect to the specific embodiments disclosed herein is intended or should be inferred. | The present invention is a replacement gunstock assembly for rifles. The assembly comprises a stock body with a uniform mounting structure and one of a series of adapters made to accept the mounting structure and then mount, in turn, on a given rifle platform. Also disclosed is attachment means for holding the stock body and adapter together. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a setting tool for driving fastening elements in a constructional component and including a piston guide having a hollow chamber, a setting piston axially displaceable in the hollow chamber and having a piston head and a piston stem adjoining the piston head, a bolt guide adjoining the piston guide in a setting direction of the setting tool, and a piston stop device for braking the setting piston, located at an end region of the hollow chamber adjacent to the bolt guide, the piston stop device having a damping element supported against a bottom and a stop element for the setting piston and adjoining the damping element in a direction of the hollow chamber.
2. Description of the Prior Art
Setting tools of the type described above can be operated with solid, gaseous, or fluid fuels or with compressed air. With combustion-operated setting tool, the setting piston is driven by combustion gases. The setting tool can drive fastening elements such as, e.g., nails or bolts in a constructional component.
In setting tools such as disclosed in German Publication DE 39 30 592 A1, the setting piston is displaceably arranged in a piston guide axially displaceable in a housing sleeve of the setting tool. For initiating a setting process, the setting tool has to be pressed against a constructional component so that the piston guide is pushed into the housing sleeve. In order to reduce the piston energy at faulty settings or to reduce an excessive setting energy, there is provided, in the front portion of the piston guide, in the end region of the piston guide adjacent to the bolt guide, an elastic annular member for braking the setting piston.
The drawback of the known setting tool consists in that when the wear of the elastic annular member is too large and the wear is not recognized, essential and expensive tool components can be damaged. Further, the piston collar that impacts the annular member, should have as large a diameter as possible to prevent a premature damage of the annular member. This increases the weight of the setting tool. On the other hand, because of the elasticity of the annular member, the setting piston rebounds after impacting the annular member, and this leads, in particular at a high setting energy, to undesirable second blows with the setting piston.
German patent DE 196 17 671 C1, from which the present invention proceeds, discloses a powder charge-operated bolt setting tool with a setting piston displaceable in a guide bore. The setting piston has a piston head and a piston stem, with the piston head forming, at its side adjacent to the piston stem, a conical section. A conical receptacle, which is provided at the mouth-side end of the guide part, is arranged opposite the conical section formed by the piston head. At a faulty setting or an excessive setting energy, the conical section of the piston head passes into the conical receptacle. A damping disc, which is arranged behind the conical receptacle in the setting direction, dampens the impact of the piston.
In the setting tool of the above-mentioned German patent, an increased wear of the elastic damping disc, which takes place in the setting tool of DE 39 30 592 A1, is prevented. However, in the setting tool of the German patent, the other drawback of DE 39 30 592 A1, namely, rebound of the setting piston, leading to secondary blows, remains.
U.S. Pat. No. 4,824,003 discloses a setting tool in which between the piston guide and the bolt guide, there are provided a first rigid ring and an elastic ring arranged one after another. In the elastic ring, there is provided a further, more rigid ring that limits the stroke of the first rigid ring. The first rigid ring has a through-guide for the piston stem tapering in the setting direction. The piston collar surface adjacent to the first rigid ring is formed as a conical surface, with the profiles of the conical surface of the through-guide and the conical surface of the piston collar complementing each other.
The setting tool of the U.S. patent has the same drawback as the setting tool of the German patent. Here, likewise, possible rebounds of the setting piston can lead to the secondary blows.
Accordingly, an object of the present invention is to provide a setting tool of the type discussed above in which the foregoing drawbacks are eliminated, and the rebound speed of the setting piston is reduced to a minimum.
SUMMARY OF THE INVENTION
This and other objects of the present invention, which will become apparent hereinafter, are achieved by providing a setting tool including an inertia body cooperating with the stop element and displaceable in a direction parallel to a longitudinal extent of the setting piston between a first stop and a second stop both of which are connected with the stop element. A distance between the first stop and the second stop, in a direction parallel to the longitudinal extent of the setting piston, is greater than a length of the inertia body in a same direction by a length of a decoupling path.
Addition of the inertia body leads to a new mass distribution. As a result of mass distribution, at the first contact between the setting piston and the stop element, it is not the inertia force of the total mass of the stop element and the inertia body that acts as a counter-force on the setting piston for braking the setting piston. Rather, only a portion of the inertia force ascribed to the mass of the stop element acts on the setting piston. Thereby, the force peak, which appears on an impact, is reduced, and the setting piston is less loaded. Further, the multi-stage braking of the setting piston is achieved with a smaller resilient deflection, which positively influences the service life of the setting piston and the bolt guide. Still further, the stop element, upon rebound of the damping element, shortly after its change of direction, is displaced away from the inertia body in a direction opposite the setting direction, while the inertia body, because of its mass moment of inertia continues to displace in the setting direction within limits of the decoupling path. This displacement is stopped when the inertia body contacts the second stop. This leads to a low, non-critical rebound speed of the setting piston.
Advantageously, the inertia body is ring-shaped at least regionwise and is displaceable along a circumferential track provided on the stop element. Thereby, tilting and an outside function of the inertia body is prevented. Alternatively, the track can be provided on the piston guide.
Advantageously, the decoupling path has a length from about 0.2 mm to 3 mm, preferably, from 0.25 mm to 2 mm, which insures an optimal effect of the inertia body.
According to an advantageous embodiment of the present invention, the inertia body is formed as an elongate body projecting beyond the stop element in a direction opposite the bolt guide and has a collar embracing the stop element. This formation of the inertia body further increases its mass, which further reduces the rebound speed of the setting piston.
The novel features of the present invention, which are considered as characteristic for the invention, are set forth in the appended claims. The invention itself, however, both as to its construction and its mode of operation, together with additional advantages and objects thereof, will be best understood from the following detailed description of preferred embodiments, when read with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The drawings show:
FIG. 1 a longitudinal, partially cross-sectional view of a setting tool according to the present invention with a piston stop device;
FIG. 2 a view of a detail of the setting tool shown in FIG. 1 marked with reference character II at an increased, in comparison with FIG. 1 , scale; and
FIG. 3 a view similar to that of FIG. 2 of another embodiment of a setting tool according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A setting tool 10 according to the present invention, which is shown in FIGS. 1-2 , has a piston stop device generally designated with a reference numeral 30 . The setting tool 10 further includes a one- or multi-piece housing 11 and a piston guide 13 arranged in the housing 11 . In the hollow chamber 14 of the piston guide 13 , a setting piston 20 is displaceably arranged. The setting piston 20 is driven by a propellant or its reaction products, e.g., combustion gases or the like. The setting piston 20 has a piston stem 21 that adjoins, in a setting direction 40 of the setting tool 10 , a piston head 23 . On a piston stem 21 , there is provided a piston collar 22 in a spaced relationship to the piston head 23 . The piston collar 22 has a counter-stop surface 24 facing in a direction of the piston stop device. The counter-stop surface 24 is formed, in the embodiment shown in FIGS. 1-2 , as a conical surface. The piston collar 22 can be arranged differently than shown in the drawings but always should be located in a region of the piston head 23 lying in the setting direction. The piston guide 13 is displaceably supported in the sleeve-shaped housing 11 and is supported against the housing 11 by a spring 19 . At an end of the piston guide 13 facing in a direction opposite the setting direction 40 , there is provided a cartridge socket 25 for receiving a propellant in the form of a cartridge, pellet or blister.
A setting process with the setting tool 10 is only then possible when the setting tool 10 is pressed with a bolt guide 12 , which is located in front of the piston guide 13 in the setting direction 40 , against a constructional component (not shown). An interface 26 , at which the bolt guide 12 is connected with the piston guide 13 , is formed, e.g., as a threaded section. For activating the setting tool 10 for initiating a setting process, there is provided on the setting tool 10 , an actuation switch 18 .
At the end of the piston guide 13 adjacent to the bolt guide 12 , the above-mentioned piston stop device 30 is located. The piston stop device 30 is supported against bottom 15 of a receptacle 16 formed in the bolt guide 12 . In the embodiment shown in the drawings, the piston stop device has a damping element 31 , which is formed as an elastomeric ring, and stop element 32 which is formed as a metal sleeve member or a thrust member. The damping element 31 can be vulcanized or pinned on the stop element 32 . In this way, the stop element 32 is damped indirectly and elastically by the damping element 31 , and is supported, indirectly, against the bottom 15 that forms a stop. On the stop element 32 , there is arranged an annular inertia body 33 displaceable along a track 37 provided on the stop element 32 between a first stop 35 and a second stop 36 . The first stop 35 is formed by a projection of the stop element 32 . The second stop 36 is formed on a retaining ring 34 fixedly connected with the stop element 32 , e.g., by soldering. The axial length of the track 37 is greater than the axial width of the inertia body 33 by a decoupling path 38 . The decoupling path 38 has a length of from about 0.2 mm to 3 mm, preferably, between 0.25 mm and 2 mm.
On the side of the stop element 32 remote from the bolt guide 12 , there is provided a stop surface 17 which in the embodiment shown in the drawings, is formed as a conical surface against which the setting piston 20 can rebound with the counter-stop surface 24 , which is formed on the piston collar 22 , in order for the piston stop device 30 to brake the setting piston 20 when the setting piston 20 advances up to the stop element 32 as a result of a faulty setting or because of an excessive setting energy caused by the use of a too strong propellant. The counter-stop surface 24 is complementary to the stop surface 17 and is likewise formed as a conical surface. There is further formed, in the stop element 32 , a cylindrical through-opening 39 through which the piston stem 32 extends.
When the setting piston 20 , which is displaceable in the setting direction 40 , strikes the stop element 32 , the stop element 32 is pressed in the direction of arrow 41 against the elastic damping element 31 which, as result, jolts. As a result of mass distribution, at the first contact between the setting piston 20 and the stop element 32 , it is not the inertia force of the total mass of the stop element 32 and the inertia body 33 that acts as a counter-force on the setting piston 20 for braking the setting piston 20 . Rather, only a portion ascribed to the stop element 32 . The inertia body 33 , upon ignition, is displaced by inertia forces in an initial position shown in FIG. 2 . Thereby, the force peak, which appears upon the impact, is reduced, and the piston 20 is less loaded.
Over the length of the decoupling path 38 , the setting piston 20 is displaced in the direction of arrow 41 together with the stop element 32 , without entraining the inertia body 33 . After crossing the decoupling path 38 , the first stop 35 , which is formed by the displaceable stop element 32 , abuts the inertia body 33 . As a result, the mass of the inertia body 33 is added to the mass of the stop element 32 , with the inertia member 33 movable in direction of arrow 42 , and the setting piston 20 is subjected to a new braking effect. Also, the resilient deflection of the stop element 32 by the damping element 31 , which is located in the receptacle 16 of the bolt guide 12 , is reduced in comparison with a case when a stop element is used without an axially displaceable inertia body. The multi-stage braking of the setting piston 20 and a smaller resilient deflection positively influence the service life of the setting piston 20 and the bolt guide 12 .
Upon the stop element 32 being displaced by a maximum resilient deflection path, the speed of the stop element 32 is reduced to zero within the system. At that time, decoupling between the stop element 32 and the inertia body 33 takes place. The stop element 32 , upon rebound of the damping element 31 , shortly after its change of direction, is displaced away from the inertia body 33 in a direction opposite the direction of arrow 41 . The inertia body 33 , because of its mass moment of inertia continues to displace in he direction of arrow 42 within limits of the decoupling path 38 . This displacement is stopped when the inertia body 33 contacts the second stop 36 . This leads to a low, non-critical rebound speed of the setting piston.
Alternatively to the above-described embodiment, the inertia body 33 can be formed, e.g., of two parts, e.g., in form of two ring halves. This is an advantage for assembly purposes because the retaining ring 34 can be eliminated, with the second stop 36 being also formed on the stop element 32 . The two-part inertia body 33 can be placed, during assembly, between the two stops 35 , 36 and, after mounting of the stop element 32 at the end of the piston guide 13 , be held in its position on the track 37 of the stop element 32 by the piston guide 13 .
The setting toot shown in FIG. 3 differs from the setting tool shown in FIGS. 1-2 in that in the embodiment shown in FIG. 3 , the piston stop device 30 has an elongate, sleeve-shaped inertia body 33 which is connected with the stop element 32 by a bayonet connection. To form this connection, the stop element 32 has bayonet recesses 43 through which bayonet studs 44 , which are provided on the inertia body 33 , are extendable, with the inertia body 33 being secured on the stop element 32 by being rotated relative to the stop element 32 . The inertia body 33 forms a collar 45 extending perpendicular to the piston stem 21 and embracing the end of the stop element 32 remote from the bolt guide 12 . This construction of the inertia body 33 permits an increase of its mass, whereby the rebound speed of the setting piston can be further reduced. Further, a better guidance of the inertia body 33 is achieved because of a large guide surface in the piston guide.
Though the present invention was shown and described with references to the preferred embodiments, such are merely illustrative of the present invention and are not to be construed as a limitation thereof and various modifications of the present invention will be apparent to those skilled in the art. It is therefore not intended that the present invention be limited to the disclosed embodiments or details thereof, and the present invention includes all variations and/or alternative embodiments within the spirit and scope of the present invention as defined by the appended claims. | A setting tool for driving fastening elements in a constructional component includes piston stop device for braking the setting piston, and is located at an end region of the hollow chamber of the piston guide in which the setting piston is displaceable, and has a damping element supported against a bottom, a stop element for the setting piston and adjoining the damping element in a direction of the hollow chamber, and an inertia body cooperating with the stop element and displaceable in a direction parallel to a longitudinal extent of the setting piston between first and second stops both of which are connected with the stop element and a distance between which, in a direction parallel to the longitudinal extent of the setting piston, is greater than a length of the inertia body in a same direction by length of a decoupling path. | 1 |
The invention described herein was funded, in part, by grant number R43NS34616 from the National Institutes of Health, and is subject to a nonexclusive licensing agreement with the United States government.
1. Technical Field
The present invention relates to neurological diagnostic tools. More particularly, the present invention relates to an improved radiant heatbeam dolorimeter for determining a subject's cutaneous pain tolerance level at any site on the body.
2. Background Art
Pain is the single most common symptom for which patients seek medical treatment and there is currently no objective method available for its measurement. Present methods of quantifying "pain" are little more than lexicons for its verbal description or biomechanical methods for measuring the restriction of articular range of motion or activities of daily living associated with the pain. Some psychometric methods attempt to quantify the personality or cognitive distortions from which the pain patient suffers. In no case, however, do these methods reveal the covert and subjective sensory perception that is the pain experience in a way that can be quantified by an outside observer (for review, see Lipman 1991). The need for pain measurement methods was recently addressed by both the Social Security Administration and the United States Congress. A report ordered by Congress through the Secretary of Health and Human Services by a Commission on the Evaluation of Pain, recommended that some sort of objective measurement of pain be developed to assist in determining disability (see: Fordice 1995, Fields 1995, APS 1990).
The need for objective pain measurement goes beyond the economics of forensic disability assessment. Objective methods of pain measurement are required for accurate assessment of patient complaint and to assure appropriate treatment. For example, the need to appropriately medicate severe acute and chronic pain and also cancer pain requires an objective method of pain measurement. A corollary need is to avoid inappropriate treatment of pain--or claimed pain--where the possibility of malingering for secondary gain is a possibility. Such "secondary gains" are believed to account for an appreciable portion of chronic pain treatment demand, and forensically include the desire for disability payments, for insurance damage settlements or for other fiduciary incentives. Such secondary gains are not always conscious and may derive from psychological reasons related to the psychosocial set and setting of the patient and their disease. The inappropriate desire for opiate drugs probably accounts for a significant fraction of pain therapy prescription drug demand, yet absent any objective method of establishing the existence of "pain", the physician has no objective standards by which to prohibit such demand, and frequently feels ethically bound to take claims of pain at face value, or risk accusation of ineffective care and inhumane treatment.
Furthermore, an objective pain measurement device that is operable in the general practitioner's office would fulfill a pressing diagnostic need. It is from the general practitioner's office that referrals to neurologists are made. For example, patient complaints of subjective numbness arc often not detectable on clinical examination because present diagnostic methods are not sensitive enough to detect the early stage sensory impairments of such neurological disorders as nerve root entrapment or peripheral neuropathy. As a result, patients with these types of neurological disorders cannot be diagnosed until the disorder progresses to a detectable level. The availability of a pain measurement device sensitive enough to detect the presence or absence of these and other abnormalities at an early stage would provide more effective medical intervention, or avoid unnecessary medical intervention. In order for such a device to be cost-effective for the general practitioner it should not require valuable dedicated space, and thus should be portable. Similarly, greater cost-effectiveness would be realized if the device were operable by a single person.
Basic psychophysical methods for the estimation of pain sensibility have a long history of questionable clinical relevance. Psychophysical methods seek to quantify pain intensity in an objective fashion despite the fact that pain is a complex and multi-faceted sensory mode, intrinsically containing dimensions of set, setting, ideation, memory, anxiety, and experiential import.
Subjective pain perception does not bear a simple relationship to stimulus intensity, but it nevertheless has some quantifiable dimensions and limits; a lower level of identity (the pain threshold) and an upper level of identity (the tolerance level). Below the pain threshold, stimuli of increasing intensity destined to broach this level are perceived as noxious yet non-painful (prepain). The pain threshold itself is highly labile and subject to psychological manipulation either of imposed suggestion (experimenter bias) or autosuggestion bias (the placebo response) or both. No studies have been able to demonstrate a relationship between pain threshold and the underlying pain state; in fact, pain threshold measurement procedures arc unable to quantitatively demonstrate analgesic states engendered by clinically proven drugs as, for example, morphine (for review, see Chapman, et al.). Furthermore, the method suffers from major disadvantages when transferred to the clinical situation where the test subject, who may suffer excruciating pain of endogenous pathological origin, is less able to attend to the minor sensory nuances of the pain threshold.
The pain sensitivity range constitutes a psychophysical region between the pain threshold level, where prepain becomes subjectively painful, and the pain tolerance level, which represents the greatest intensity of a noxious stimulus that a subject can tolerate (Hardy et al). In contrast to the pain threshold level, the pain tolerance level is subjectively distinct and unequivocal. Further, the pain tolerance level exhibits a linear change with stimulus intensity and yet it shares a sufficient commonality with the physiological processes of endogenous pathological pain perception that are positively influenced by changes in the endogenous pain state.
Pain tolerance levels are usually assessed by the use of a continuous, rather than a discrete, noxious stimulus, the cut-off of which is always the maximum limit of the subject's subjective pain tolerance. Pain tolerance has been measured by several means including the cold pressor test in which the hand or a limb is immersed in ice water until unendurable pain results, focal pressure, tourniquet ischemia and radiant heat. (For review see Lipman, 1991.) Tolerance methods using these techniques, unlike threshold methods, also evoke some not inconsiderable anxiety and apprehension on the part of the subject, which may resemble the anxiety of the pain-suffering patient. However, studies have shown that tactile stimulation interferes with that aspect of cutaneous tolerance limit responsive to internal pain interference and thus methods that utilize a contact stimulus invalidate pain tolerance level results. While the cold pressor, focal pressure and tourniquet ischemia tests all involve tactile stimulation, radiant heat methods do not require direct contact with the subject.
The concept of a radiant heat pain stimulator for human use was initially developed by Hardy, Wolff and Goodell in 1952. However, most radiant heat pain stimulators have been designed to measure the pain threshold level and thus are prone to thc disadvantages inherent in measuring pain threshold. Recently, a concept prototype heat pain stimulator was developed that measures the pain tolerance level (see Lipman, et al 1987; Lipman and Blumenkopf 1989; and Lipman, et al. 1990). The concept prototype was a nonportable, electromechanical device that did not allow for automatic data acquisition. As such, the concept prototype required dedicated laboratory space and also required one person to operate the device and a second person to record data. Accordingly, there remains a need in the art for a non-contact, radiant heatbeam dolorimeter that provides a quantitative, objective measure of the pain tolerance level, is portable and allows for automatic data acquisition.
SUMMARY OF THE INVENTION.
The present invention fulfills the need for a non-contact, radiant heatbeam dolorimeter that provides a quantitative, objective measure of the pain tolerance level, is portable and allows for automatic data acquisition. These features of the present invention allow for its use as a cost-effective diagnostic tool in the general practitioner s office, thereby allowing for earlier assessment of neurological abnormalities than is possible with currently available pain measurement devices. The present invention allows for chronic pain diagnosis, the diagnosis of subtle sensory abnormalities, and pain measurement quality assurance. The present invention is currently alone in its ability to address both the clinical and commercial needs in quantitative pain measurement.
A first object of the present invention is to provide a portable apparatus for determining a subject's cutaneous pain tolerance level at any site on the body.
According to this object, the present invention provides, as an embodiment of the invention, an improved dolorimeter which comprises a non-contact heat projector, set inside a housing assembly, for delivering a radiant heat stimulus, to cause pain in the subject; a targeting device, attached to the heat source housing assembly, for accurately positioning the heat projector for stimulus delivery; a thermopile, also attached to the heat source housing assembly, for detecting movement in response to the stimulus that indicates the subject has reached the pain tolerance level; and computer connections to the non-contact heat projector, the targeting device and the thermopile that allow the computer to control the output of the heat projector and the targeting device, and also allows automatic data acquisition from the thermopile as to movement by the subject, thereby allowing the invention to be operated by a single person.
In a preferred embodiment of the present invention, both the heat source and the targeting device are focused on the same point on a subject's skin to allow measurement of the temperature over time at the site of heat contact. When a subject moves in response to reaching the pain tolerance level, the heat source and targeting device will then be focused on a different point of the subject's skin, resulting in the targeting device recording a drop in temperature.
Additionally, in accordance with an embodiment of the present invention, the computer allows for interfacing between the computer and the subject, as well as between the computer and the computer operator, to allow for input by the subject or the operator. Moreover, in accordance with an embodiment of the present invention, the computer automatically acquires and records input from the interface between the subject and the computer, the interface between the computer and the computer operator, thereby facilitating the invention's operability by a single person.
The present invention further provides for a method of determining a subject's cutaneous pain tolerance level at any site on the body.
According to this object, the present invention discloses, as an embodiment of the invention a method which comprises providing a portable apparatus comprising:
a non-contact heat projector, set inside a housing assembly, for delivering a radiant heat stimulus, to cause pain in the subject; a targeting device, attached to the heat source housing assembly, for accurately positioning the heat projector for stimulus delivery; a thermopile, also attached to the heat source housing assembly, for detecting movement in response to the stimulus that indicates the subject has reached the pain tolerance level; and computer connections to the non-contact heat projector, the targeting device and the thermopile that allow the computer to control the output of the heat projector and the targeting device, and also allows automatic data acquisition from the thermopile as to movement by the subject, thereby allowing the invention to be operated by a single person. Additionally, in accordance with an embodiment of the present invention, the computer allows for interfacing between the computer and the subject, as well as between the computer and the computer operator, to allow for input by the subject or the operator. Moreover, in accordance with an embodiment of the present invention, the computer automatically acquires and records input from the interface between the subject and the computer, the interface between the computer and the computer operator, thereby facilitating the invention's operability by a single person.
The method of the invention further comprises initiating a stimulus of a controlled intensity from the non-contact heat projector; monitoring the time interval between initiation of the stimulus and detection by the thermopile that the subject has reached pain tolerance level, the interval, or the power-time integral thereof, being a measure of pain tolerance latency at the monitoring site, and automatically acquiring and recording the pain tolerance latency data generated by the thermopile via the computer connection with the thermopile.
Moreover, in accordance with an embodiment of the present invention, the computer processes the pain tolerance latency data to obtain statistical data, which it stores.
Finally, in accordance with an embodiment of the present invention, the computer displays both the pain tolerance latency data and statistical data obtained by processing the pain tolerance latency data.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A and 1B are illustrations of the operation of the dolorimeter.
FIG. 2 is a representative graph recording the change in temperature over time measured by the targeting device of the dolorimeter.
FIG. 3 is a generalized block diagram illustration of a top view of the dolorimeter instrument package in accordance with a preferred embodiment of the invention.
FIG. 4 is a side view of an assembled dolorimeter heating assembly in accordance with a preferred embodiment of the invention.
FIG. 5 is a top view of an assembled dolorimeter heating assembly in accordance with a preferred embodiment of the invention.
FIG. 6 is a block diagram of the computer connections with the dolorimeter apparatus in accordance with a preferred embodiment of the invention.
FIG. 7 is a flow chart detailing a method for determining a subject's cutaneous pain tolerance level at any site on the body in accordance with a preferred embodiment of the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to FIG. 1A-1B there is illustrated a method for determining a subject's cutaneous pain tolerance level at any site on the body. As illustrated in FIG. 1A a heat source 1 and a targeting device 19 are focused on the same site of a subject's skin 31 where the pain tolerance level is to be measured. The targeting device 19 continually measures the increase in skin temperature caused by the heat source 1 at that site on the subject's skin 31. Upon reaching the pain tolerance level (PT), the subject moves and thereby the site that the heat source 1 and targeting device 19 are focused upon changes (FIG. 1A) to a previously unheated site. As a result or reaching the pain tolerance level (PT), the targeting device records a sharp drop in temperature at the site of focus, as illustrated in FIG. 2. In a preferred embodiment, the targeting device comprises an infrared-sensing thermopile, such as an Omega OP65 device.
Referring now to FIG. 3, there is illustrated a portable apparatus for determining a subject's cutaneous pain tolerance level at any site on the body in accordance with a preferred embodiment of the invention. The apparatus comprises a heating head I associated with a double linkage parallelogram arm 2, preferably fabricated out of hollow steel tubing. The linkage arm is further connected to a pivot base 3, which is present in the dolorimeter instrument package. The dolorimeter instrument package is encased in a portable container and comprises, in addition to the pivot base, a lap top computer 4, such as an IBM 760C portable computer, which receives electrical power from an internal battery. The computer has two PCMCIA card slots, and one of the slots contains an interface card, such as a ComputerBoards PCM-DAS 16/12D interface card. This card contains four digital inputs, 8 differential analog-to-digital input channels and four digital outputs. The internal computer battery inputs its voltage status to the computer via a differential analog-to-digital input channel. Associated with the computer in the dolorimeter instrument package is a battery 5 to provide electrical power to the components of the heatbeam dolorimeter, an electrical strip 6, a battery charger 7 for recharging the heatbeam dolorimeter battery and the computer battery, and a lap top computer power supply 8.
Reference is now made to FIGS. 4-5, the heatbeam dolorimeter comprises a heat projector 9, such as a Sylvania type DNE 150 watt, 24 volt, tungsten-halogen projector lamp, which gives approximately concentric radiance as measured by the naked eye when viewing the projected light on a screen 18 centimeters from the bulb. Other bulbs can be used having the same or similar projected radiance pattern and power-temperature profile, provided the bulb is first calibrated. The calibration criteria are that the bulb must create (i) a broad focal spot size of peak heat delivery of 20+/-0.2 mm at 5.08 centimeters from the edge of the lamp housing, measured using Sharp OF-20PrW thermal paper over 20 seconds exposure; and (ii) a temperature rise of 5.2+/-0.1 centigrade degrees at the calibrating thermocouple at the tenth second of irradiation.
The heat projector 9 is set in a lamp socket 10 inside a heat source housing assembly comprising a heat source cover 11, a stove 12, a carriage trap 13, a bottom cover 14, a front aperture cover 15, a back cover 16, and a carriage 17. The heat source housing assembly is preferably constructed of 2024 aluminum for optimal heat dissipation, except for the front aperture cover 15 of the housing, which is preferably milled from 1045 steel. Associated with the heat projector is a miniature cooling fan 18 within the posterior of the heat projector housing assembly. Also associated with the heat projector is an infrared sensing thermopile 19, such as an Omega OP65 device. The thermopile 19 receives electrical power from the battery 5 in the dolorimeter instrument package. Also associated with the heat projector are two laser positioning diodes 20 with integrated optics and driver, such as those made by Coherent Applied Laser Systems, part number 0220-058-00, with output power of 4.2 mW and an emission wavelength at 670 nM (visible, red). The laser positioning diodes 20 of the targeting device 19 receive electrical power from the battery 5 in the dolorimeter instrument package. The two positioning diodes 20 and the thermopile 19 are mounted 120 degrees from each other on the exterior of the heat projector housing.
Referring now to FIG. 6, the heat projector 9 is controlled by a digital output connection, through the PCMCIA interface card 22 with the computer 4. The digital output controlling the heat projector has the capability of pulse frequency modulation. By having this digital output drive a one shot circuit, the pulse frequency is changed to pulse width modulation. This pulse width modulation is used to control the intensity of the heat beam. The computer determines the width of the pulse driving the heat projector using a calculation based on desired heat projector intensity and the battery voltage reading 23. As the battery is discharged, its voltage decreases and without some compensation, the heat projector intensity would also decrease. For this reason, the computer must modify the pulse width to compensate for the measured battery voltage.
The two laser positioning diodes 20 are connected to laser drivers 24 that are controlled by the computer 4 via a digital output connection 25 through the PCMCIA interface card 22. The miniature cooling fan 18 is connected to a fan driver 26 that is controlled by the computer 4 via a digital output connection 27 through the PCMCIA interface card 22. The infrared-sensing thermopile 19 is connected to an amplifier 28 delivering a signal which is related to the skin temperature target but not calibrated to read exact temperature. When the temperature measured by the thermopile 19 drops significantly, as occurs when the patient moves at their pain tolerance point, the heat projector 9 disengages and reports the time--the tolerance latency--to the database via a differential analog-to-digital input channel 29, through the PCMCIA interface card 22. The battery which powers the heat projector 9 also communicates to the computer via a differential analog-to-digital input channel 30 through the PCMCIA interface card 22.
The start button is depressed a second time and the lasers extinguish while the heat beam initiates 40. The heatbeam stimulus is stopped, and the "beam on" time recorded, either when the patient moves, as detected by the infrared sensing thermopile, or when the subject presses the patient stop button 42. A third button, the abort button, is pressed by the operator when some distracting event occurs in the room which could invalidate the reading. Referring to FIG. 6, the status of the stop 42, abort 43 and start buttons 44 are all communicated to the computer via a digital input connection through the PCMCIA interface card.
Referring now to FIG. 7, there is illustrated a method for determining a subject's cutaneous pain tolerance level at any site on the body in accordance with a preferred embodiment of the invention. The method comprises providing a portable, computerized heatbeam dolorimeter apparatus as disclosed above. An embodiment of the method comprises painting the subject's skin 31 at the site to be tested with a matt black skin stain, such as Avery-Dennison type 42 non-toxic ink, to enhance absorption of the radiant heat generated by the heat projector.
In a preferred embodiment, the computer software was written in Microsoft Visual Basic, running under Windows 95. Each screen (called a "Form") is provided with "buttons" to operate choices. The buttons are selected by the mouse on the computer. When the computer powers up 32 the first form displayed is called the MainHeat Form. This form provides selections to either calibrate the dolorimeter apparatus or to input demographic data for the experiment. The calibration form allows the operator to record the temperature caused by the heatbeam when focused on a temperature sensing device. The demographics screen 33 has text boxes for entry of relevant demographic data 34 concerning the subject. From the demographics form one can press a button to go to either the therapeutic exam setup form 35, for use when the subject is to be tested both before and after some type of therapy, or the standard exam setup form 35, which presents an outline of the subject's body with sites to be tested designated as such 36. This information is processed to the standard exam setup form, and the data is automatically entered into a table in the sensorium form 37, where the technician also inputs data from the subject's pain questionnaire 38. The recorded data is then archived to the database.
To measure tolerance latency at a particular site, the exam form 39 is recalled on the computer, and the heatbeam dolorimeter head is pointed at the approximate body site on the subject and the start button on the computer is depressed one time. The two laser diodes then illuminate and the dolorimeter head is adjusted so that the two laser beams converge at the center of the black spot on the subject's skin. The start button is depressed a second time and the lasers extinguish while the heat beam initiates 40. The heatbeam stimulus is stopped, and the "beam on" time recorded, either when the patient moves, as detected by the infrared sensing thermopile, or when the subject presses the patient stop button 41. A third button, the abort button, is pressed by the operator when some distracting event occurs in the room which could invalidate the reading. Referring to FIG. 6, the status of the stop 42, abort 43 and start buttons 44 are all communicated to the computer via a digital input connection through the PCMCIA interface card.
From the exam form, means are provided on the screen for going to the sensorium form where the data may be viewed to verify completeness before permanently saving it. From that screen, the operator may return to the demographics form and process another subject, or may test the next site indicated on the exam screen 45.
It will be appreciated by persons with skill in the art that the present invention is not limited to what has been particularly shown and described hereinabove. Rather, the scope of the present invention is defined only by the claims that follow: | The present invention provides both devices and methods for determining a subject's cutaneous pain tolerance level at any site on the body so as to provide both for examiner and subject input as well as automatic data acquisition.
The present invention fulfills a need for a devices and methods that provide a quantitative, objective measure of the pain tolerance level. The portability and automatic data acquisition capability of the present invention allow for its use as a cost-effective diagnostic tool in the general practitioner's office, thereby allowing for earlier assessment of neurological abnormalities than is possible with currently available pain measurement devices. The present invention further allows for chronic pain diagnosis, the diagnosis of subtle sensory abnormalities, and pain measurement quality assurance. The present invention is currently alone in its ability to address both the clinical and commercial needs in quantitative pain measurement. | 0 |
BACKGROUND OF THE INVENTION
(1) Field of the Invention
This invention relates to a method for correcting measurement errors due to radial runout of rims and/or of a load wheel in a tire uniformity inspecting machine.
(2) Description of the Prior Art
In tire uniformity inspecting machines, the uniformity of a tire is inspected by measuring variations in the reaction force of a tire as imposed on the circumferential surface of a load wheel which is maintained at a constant distance from the center of tire-supporting rims. However, it is often the case that the measured values contain errors due to rotational deflections of the rims which grip the inspecting tire and/or of the load wheel. For example, if a rim with a rotational deflection of 25 microns is used for the inspection of a tire with a spring constant of 20 kgf/mm, the measured RFV (radial force variation) contains an error of 0.5 kgf which is a value obtained by multiplying the amount of radial runout by the spring constant. Recently, tires have been considerably improved in the value of uniformity and usually are required to have a RFV value smaller than 10 kgf, in some cases a RFV value of 8 kgf or 5 kgf. Therefore, the error component of 0.5 kgf in such a small RFV value is unignorable and should be suppressed to a minimum. Of course, the rotational component parts of the tire uniformity inspecting machines are manufactured with an extremely high precision, including the upper and lower rims, the mechanism for rotating the rims, and the load wheel. However, as a matter of fact, it is impossible to make zero the deflections of the machined rotational component parts partly because of technical difficulties and partly because of uneconomically large expenses involved in the machining operations. In addition, small deflections also occur due to deteriorations of the rotational component parts or due to rust or bruises which are developed on the tire retaining portions during use of the inspecting machines. Even if the rotational component parts are fabricated with an accuracy on the order of 10 microns as unit bodies, a radial runout builds up to a value on the order of 20 microns and are developed when they are assembled. Since complete elimination of the rotational defections of the rims and load wheels is difficult, it is more practical to accept a certain degree of deflections and to correct errors of measurement due to deflections of rims and/or a load wheel by subtracting influences of rotational deflections from measured values.
SUMMARY OF THE INVENTION
With the foregoing situations in view, the present invention has as its object the provision of a method for correcting errors of measurement as caused in tire uniformity inspecting machines due to radial runout of tire-supporting rims and/or a load wheel.
It is a more specific object of the present invention to provide a method for eliminating an erroneous component which creeps into the measured value of radial force of a tire due to rotational deflection of the rims and/or load wheel.
According to one aspect of the present invention, there is provided a method for correcting errors of measurement in a tire uniforming inspecting machine having a pair of upper and lower rims engageable with bead portions of a tire for gripping the tire securely for rotation at a predetermined position and a load wheel engageable with the circumference of the tire at one side thereof to check for variations in the radial force. The method includes: measuring radial runout of the rims and/or load wheel to obtain an erroneous deflection signal indicating the amount of radial runout of the rims and/or load wheel; obtaining and storing a primary harmonic component of the erroneous deflection signal; measuring variations in radial force of a tire rotated on the rims to obtain a radial variation signal for a period of one revolution of the tire; multiplying the erroneous deflection signal by a spring constant of the tire to obtain an erroneous variation signal; and subtracting the erroneous variation signal from the radial variation signal to eliminate influence of radial runout of the rims and/or load wheel from the measured value of the radial force of the tire.
The rims are usually rigidly fixed to an end portion of a drive shaft, so that it may occur that the rotational deflections of one rim remain the same and the data of one measurement is effective until it is replaced. However, actually this is not the case. One rim shows different radial deflections due to wear of the rim itself by contact with tires, production of rust or other factors. Therefore, it is desirable to measure the rotational deflections of rims every other week or at suitable time intervals.
A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic perspective view of a tire uniformity inspecting machine incorporating the method of the present invention;
FIG. 2 is a diagrammatic front elevational view of the same inspecting machine;
FIG. 3 is a diagrammatic vertical cross-sectional view showing on an enlarged scale main component parts of upper and lower rim assemblies;
FIG. 4 is a diagrammatic perspective view showing relative positions of rotating component parts by various detectors;
FIG. 5 is a diagrammatic plan view of the rotating component parts and detectors shown in FIG. 4;
FIG. 6 is a diagram showing waveforms of signals appearing at various points of a correcting circuit;
FIG. 7 is a diagrammatic illustration showing flow of various signals;
FIG. 8 is a block diagram of an arithmetic operation circuit;
FIG. 9 is a diagram showing waveforms of signals appearing at various points of the arithmetic operation circuit;
FIG. 10 is a diagrammatic illustration showing another embodiment of the invention;
FIG. 11 is a diagrammatic illustration of a load wheel in contact with a tire in still another embodiment applying the principles of the invention to the correction of errors due to radial deflections of the load wheel;
FIG. 12 is a diagrammatic illustration showing flow of various signals;
FIG. 13 is a block diagram of an arithmetic operation circuit; and
FIG. 14 is diagram showing waveforms of signals appearing at various points of a correcting circuit.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now to the accompanying drawings wherein like reference numerals designate identical or corresponding parts throughout the several views, and first to FIGS. 1 to 3, there is shown a tire uniformity testing machine incorporating the correcting method according to the present invention, in which indicated at (a) is a tire to be inspected, and at 1 a conveyer with a multitude of rollers 2 which are rotatingly driven in one direction for transferring the tire (a). Centrally at a predetermined position of the conveyer 1, there is provided an opening 3 which is formed by removing part of the rollers 2 and which has a size small enough for preventing the tire (a) from falling. Designated at 4 is an upper rim which is located above the opening 3 and which is provided with a circular flange 5 which snugly engages with the inner peripheral edge of one bead portion of the tire (a). The upper rim 4 is detachably secured to a seat member 7 at the lower end of a drive shaft 6 by screws 8. The drive shaft 6 is axially provided with a compressed air passage 9 in communication with a downwardly diverging conical bore 10 which is formed in the seat member 7. The seat member 7 is attached to the lower end of the drive shaft 6 by screws 11. The drive shaft 6 is supported by a pair of conical roller bearings 12 and 13 in a bearing case 14 for rotation about a vertical axis alone, and rotatingly driven in an arbitrary direction from a motor 15 through a belt 17 lapped around pulleys 16 and 18. The bearing case 14 is mounted on an overhanging support beam 20 of a machine frame 19 which supports the roller conveyer 1. Denoted at 21 is a lower rim which is located immediately beneath the opening 3. The lower rim 21 is provided with a circular flange 22 which snugly engages with the inner peripheral edge of the other bead portion of the tire (a) and which is detachably mounted at the upper end of an elevator shaft 24 by screws 23. The elevator shaft 24 is provided with an axially projected nose portion 25 which is disengageably engageable from beneath with the conical bore 10 in the seat member 7. When the nose portion 25 is held in pressed engagement with the conical bore 10, air ports 26 which are in communication with the air passage 9 in the drive shaft 6 are opened in radial directions to supply compressed air into the tire (a) which is gripped between the upper and lower rims 4 and 21. The elevator shaft 24 is supported by a pair of upper and lower conical bearings 27 and 28 in a bearing case 29 for rotation about a vertical axis alone. The bearing case 29 is formed integrally at the upper end of a piston rod 31 of a piston-cylinder 30. The piston-cylinder 30 is mounted on a lower beam 32 of the machine frame 19 for lifting up and down the lower rim 21 relative to the conveyer 1. The reference numeral 33 denotes a load wheel which is provided with load cells 34 on opposite sides thereof. The load wheel 33 is rotatably supported on a retractably movable frame 35 for idling operation about a vertical axis. The frame 35 is movable toward and away from the tire (a) along the upper beam 20 of the machine frame 19 and driven back and forth from a reversible motor 39, through a screw shaft 36 which is fixedly mounted on the frame 35 in meshed engagement with a ball screw type rotation-only female screw 37 which is linked to the motor 39 through a chain transmission mechanism 38. A tire (a) which has been delivered to a position immediately above the lower rim 21 by the conveyer 1 is guided into a centered position in alignment with the axes of the upper and lower rims 4 and 21 by a plural number of swingable pressing arms (not shown) which are provided centrally over the conveyer 1.
In operation, as soon as a tire (a) to be inspected is delivered by the conveyer 1 to a position above the lower rim 21, the conveyer 1 is stopped and the pressing arms are swung in to center the tire (a) in alignment with the axes of the upper and lower rims 4 and 21. Then, pressurized fluid is supplied to the piston-cylinder 30 to lift up the lower rim 21 through the piston rod 31 and elevator shaft 24, the lower rim 21 simultaneously lifting up the tire (a) from the conveyer 1. By this upward movement of the elevator shaft 24 the conical nose portion 25 is fitted into the conical bore 10 to bring the drive shaft 6 and elevator shaft 24 axially in alignment with each other, and the tire (a) is gripped air-tightly between the upper and lower rims 4 and 21. In the next phase of operation, compressed air is fed into the tire (a) through the air passage 9 and air ports 26. In this state, the upper and lower rims 4 and 21 and tire (a) are integrally rotated by the drive shaft 6, while the load wheel 33 is pressed at one side of the rotating tire (a) to check for variations in reaction force of the tire (a) around its entire circumference by the load cells 34, judging the uniformity of the tire (a) according to the results of the inspection.
Provided in the upper portion of the drive shaft 6 are a position detector 42 and a pulse sensor 43 which are associated with the drive shaft 6 through a rotary arm 40 and gears 41, respectively. The position detector 42 detects the reference point of rotational angle of the upper rim 4, while the pulse sensor 43 detects the rotational angle at the rate of 360° per revolution when the upper and lower rims 4 and 21 are rotated in synchronism with each other by engagement of the seat member 7 and elevator shaft 24. On the other hand, a position detector 44 which detects the reference point of rotational angle of the lower rim 21 is mounted on the bearing case 29. This position detector 44 is operated by a rotary arm 45 which is downwardly projected from a marginal edge portion of the lower rim 21.
Each time a tire (a) is mounted and dismantled before and after an inspection, the seat member 7 and elevator shaft 24 are coupled and uncoupled. As the seat member 7 of the upper assembly is continuedly put in rotation, there occurs a change in the relative angle (phase) in the rotational direction of the upper and lower rims 4 and 21 each time a new tire is mounted. Therefore, it becomes necessary to check the phase angles by providing position detectors 42 and 44 for the respective rims 4 and 21. With this arrangement, the reference points of the rotational angles of the upper and lower rims 4 and 21 are detected by the upper and lower position detectors 42 and 44, respectively, while sensing pulse signals at each rotational angle of 1° of the upper and lower rims 4 and 21 by the pulse sensor 43, thereby to correct errors which occur to the values of measurement in the tire uniformity inspection due to radial runout of the upper and lower rims 4 and 21, by the method as will be described hereinafter.
In order to check the radial runout, the upper and lower rims 4 and 21 which are indirectly coupled by engagement of the seat member 7 and elevator shaft 24 are rotated, without mounting a tire (a). Then, deflection detectors 46 and 47 are contacted radially from outside respectively with the upper and lower rims 4 and 21 which are in rotation to measure the amount of radial runout of each rim around the entire circumference thereof. Simultaneously, the rotational angles and reference points of the respective rims 4 and 21 are detected by the position detectors 42 and 44, respectively, sensing up the angle pulses of the indirectly coupled rims 4 and 21 by the pulse sensor 43. The positional relations in this operation are diagrammatically illustrated in FIGS. 4 and 5, and waveforms of resulting signals are shown in FIG. 6.
As shown in FIGS. 4 and 5, if the position detectors 42 and 44 are located on a line passing through the centers of the tire (rim) and the load wheel, while the flutter detectors 46 and 47 are located in positions at an angle θ with a line passing through the centers of the tire and load wheel, the amounts of radial runout of the rims 3 and 21 which are measured by the deflection detectors 46 and 47 are advanced in phase by the angle θ than the line passing through the centers of the tire and load wheel. Since the force which is produced by tire (a) under the influence of deflections of the rims 4 and 21 occurs at its contact point with the load wheel 33, the signals indicative of the amounts of radial runout measured by deflection detectors 46 and 47 have to be delayed by the angle θ in order to bring the measured amounts of radial runout on the line passing through the centers of the tire and load wheel. As shown in FIG. 6, the waveform of the deflection signal which is delayed by the angle θ from a reference point pulse, that is to say, the waveform in the period from point A 1 or A 2 to point B 1 or B 2 , which corresponds to one revolution (360°) of the rim, is the waveform of the deflection signal effective for the correction and stored in an electric circuit as will be described hereinafter. On the other hand, the lower rim 21 is uncoupled from the upper rim 4 each time a tire (a) is mounted or dismantled, so that its phase relative to the upper rim 4 changes from one inspecting operation to another. Therefore, it becomes necessary to make corrections by shifting the waveform of the deflection signal of the lower rim according to a change in phase. This can be attained by detecting by the use of the output signal Z the phase angle φ of the reference points X and Y of rotating upper and lower rims 4 and 21 with a tire (a) actually mounted therebetween, and delaying the effective period A2-B2 further by the angle φ to a period A3-B3. By these operations, the heads A1 and A3 of the effective signal periods are synchronized when the position detector 42 is actuated by the rotary arm 40 which is mounted on the drive shaft, thus reproducing the stored signals of radial runout of the upper and lower rims 4 and 21. In FIG. 6, shown at (1) is the amount of radial runout of the upper rim, at (2) the reference point signals of the upper rim 4, at (3) the runout of radial amount of the lower rim 21, at (4) the reference point signals of the lower rim 21, and at (5) the signals of the pulse sensor 43.
Now, the method of the present invention is described more particularly with reference to FIG. 7. As seen therein, the signals from a pair of load cells 34 which are mounted on the load wheel 33 are separately amplified by amplifiers 48, added by an adder 49 and, after being passed through a low-pass filter 50 for stabilization, fed to an arithmetic operation circuit 51. The two deflection detectors 46 and 47 which detect radial runout of the upper and lower rims 4 and 21 are located opposingly with respect to the respective rims 4 and 21 and in positions of the angle θ from a line passing through the centers of the tire and load wheel. The deflection detectors 46 and 47 are radially retractably supported on a piston-cylinder 52 so that they are sufficiently retracted to a position free of a tire (a) which is mounted between the upper and lower rims 4 and 21, and can be advanced into contact with the rims 4 and 21 when a tire is not mounted thereon. The output signals of the deflection detectors 46 and 47 (signals indicating the amounts of radial runout of the respective rims) are separately amplified by amplifiers 53 and passed through low-pass filters 54 for amplification and stabilization of the signals and then fed to the arithmetic operation circuit 51. The pulse signals of the pulse sensor 43 which produces 360 pulses per revolution of the drive shaft 6 as well as the signals from the position detectors 42 and 44 of the upper and lower rims are also fed to the arithmetic operation circuit 51.
The arithmetic operation unit 51 which is arranged as shown in FIG. 8 performs the operations as will be described hereafter. The signals to input terminals 105, 103, 106, 104 and 102 of the arithmetic operation unit 51 correspond to the signals (1) to (3), respectively. The signals from deflection detectors 46 and 47 indicative of the amounts of radial runout of the upper and lower rims 4 and 21, which are rotated without mounting a tire (a), are passed through the amplifiers 48 and low-pass filter 54 and fed to input terminals 105 and 106 of the arithmetic operation circuit 51. The analog quantities of these signals are digitized by A/D converters 201 and fed to θ-correction circuits 202 which offset the lead angle of lead θ of the detected signal phase. The θ-correction circuit 202 delays the received signals by θ°, for example, by the use of shift registers, in response to the output signal of a θ-setting unit 203 indicating an arbitrarily selected lead angle θ. The pulse signals of the pulse sensor 43 which produces 360 pulses per revolution of the drive shaft are used as clock pulses for the delay of θ°. On the basis of the pulse signals fed to the arithmetic operation unit 51 and θ-correction circuit 202, the deflection signals in the shift registers are delayed by the arithmetic operation unit 51 at a rate of 1° per pulse to offset the lead angle θ. After the correction of the angle θ, the deflection signals of the upper and lower rims 4 and 21 are temporarily stored in memories 204a and 204b.
Now, in an operation for inspecting uniformity of a tire (a) which is mounted between the upper and lower rims 4 and 21, if the phase angle formed by the reference points of the coupled upper and lower rims is φ, the position detectors 42 and 44 produce output signals as shown at (2) and (4) as the two rims are rotated in the same direction after coupling. The arithmetic operation unit 51 receives the output signals of the position detectors 42 and 44 at its terminals 103 and 104 and the pulse signals of the pulse sensor at its terminal 102, which is connected to φ-detection circuit 205 to determine the phase angle φ. A φ-correction circuit 206 receives the output of the φ-detection circuit 205, and the deflection signals of the lower rim 21 from the memory circuit 204b to make correction of the phase angle φ thereto. Then, the memory circuits 204a and 204b send out deflection signals of the upper and lower rims 4 and 21 to a sum-averaging circuit 207 where the signals are added and averaged. The sum-averaged deflection signal is sent, if desired, to a harmonic analyzer 208 through a switch 207, extracting a primary harmonic component of the waveform by the harmonic analyzer 208 before sending the signal to a multiplier 209 for multiplication by the spring constant of the tire (a), or the averaged signal is sent directly to the multiplier 209 without being passed through the harmonic analyzer 208 and multiplied by the spring constant of the tire which is specified by a spring constant setting unit 55. The extraction of the primary component of waveform serves to eliminate deflections of relatively small ranges due to small depressions or bruises which might be present on the rims 4 and 21, since such depressions and bruises have a great influence on the correction although not much on the tire (a) itself. FIG. 9 illustrates the foregoing signal processing operations in analog form.
The output signal 306 of the multiplier 209 is fed to a subtractor 210 which subtracts the deflection signal 306 from a variation signal which represents a variation in radial force of the tire (a) and which is fed to the input terminal 101 and A/D converter 201 of the arithmetic operation unit 51 after necessary amplification and stabilization. Thus, there is obtained a signal of variations in the radial force of the tire which is free of errors due to radial runout of the rims 4 and 21. The corrected signal is fed to a P--P (peak to peak) value calculator 56 to determine a varying component of the signal and to indicate it on a display 57. The P--P value calculator 56 and display 57 functions in the same manner as in the conventional tire uniformity inspecting machines and thus description of their functions is omitted.
It is needless to mention that the φ-correction by the arithmetic operation unit 51 can be omitted in a case where the upper and lower rims 4 and 21 are in constant relation in phase. FIG. 10 illustrates an embodiment where the upper and lower rims 4 and 21 are matched in phase.
More specifically, in the embodiment of FIG. 10, a timing pulley 58 is provided on the drive shaft 6 which rotatingly drives the upper rim 4, transmitting the rotation of the timing pulley 58 to a transmission shaft 61 through a timing belt 59 and a timing pulley 60 in order to match the phases of the upper and lower rims 4 and 21 at the time of coupling. The transmission shaft 61 which is disposed parallel with the drive shaft 6 has its upper end supported by a bearing 62 and its lower end linked to an input shaft 65 of a bevel gear box 64 through a coupling 63. The output shaft 66 of the bevel gear box 64 is linked to a transmission shaft 70 of a bearing case 29 through a universal joint 67, spline coupling 68 and a universal joint 69. In turn, the transmission shaft 70 is linked to the lower rim 21 through bevel gears 71 and 72. Thus, if the reduction ratio of the bevel gear box 64 is 1:1 and if the reduction ratio of the upper timing pulleys 58 and 60 is a reciprocal number of the reduction ratio of the lower bevel gears 71 and 72, the upper and lower rims 4 and 21 are rotated constantly in the same direction and at the same speed, thus maintaining the same phase angle.
FIGS. 11 and 12 illustrate a further embodiment of the present invention, in which the principles of the invention are applied to correct errors due to radial runout of the load wheel and which includes a deflection detector 316 located on a line passing through the centers of the tire (a) and load wheel 33 for detecting radial runout of the load wheel 33, a position detector 117 for detecting rotational angle of the load wheel 33 by way of a reference point provided on the load wheel 33, and a pulse sensor 318 associated with the load wheel 33 through a gear system 319 and rotatable with the load wheel 33 at a speed ratio of 1:1 to produce a predetermined number of pulses per revolution of the load wheel 33 in the same manner as in the preceding embodiments.
In order to check the radial runout of the load wheel 33 prior to an inspecting operation, the position detector 316 is moved forward by suitable means (not shown) for contact with the load wheel 33 when no tire is mounted on the upper and lower rims 4 and 21, and the load wheel 33 is rotated manually or by a suitable rotating mechanism (not shown), detecting radial deflections of the load wheel 33 with respect to the entire circumference thereof. Alternatively, arrangements may be made to detect radial deflections of a load wheel which is rotated in contact with an inspecting tire (a) by a position detector 316 which is located in a position free of the tire (a) as shown in FIGS. 11 and 12. The output signals of a pair of load cells 34 which are mounted in the upper end portion of the load wheel shaft are separately amplified by amplifiers 320 and added by an adder 321, which is, after being passed through a low-pass filter 323 for stabilization, fed to an arithmetic operation circuit 324. On the other hand, the output signal of the deflection detector 316 which detects radial runout of the load wheel 33 is amplified by an amplifier 325 and, after being passed through a low-pass filter 326 for stabilization, fed to the arithmetic operation circuit 324. Besides the just-mentioned two signals, the arithmetic operation circuit 324 receives the output signal of an arbitrary detector 317 which detects the reference point of rotation of the load wheel 33, the output signal of the pulse sensor 318, and the output signal of the position detector 327 which detects the reference point of rotation of the tire (a).
The arithmetic operation circuit 324 which is arranged as shown in FIG. 13 processes the received signals in the following manner. The load wheel deflection signal supplied to the terminal 401 is digitized by an A/D converter 501 and fed to a primary harmonic component extractor 502. The waveform of this signal is shown in analog form at (2) of FIG. 14. The extractor 502 has a function of calculating the primary harmonic component of the load wheel deflection signal waveform for one period of revolution of the load wheel. The signal 601 of the thus calculated primary harmonic component for one period of revolution of the load wheel is stored in a memory circuit 203. The waveform of the signal at this stage is shown in analog form at (2) of FIG. 14 with respect to one revolution of the load wheel 33. Thus, all the amount of radial runout of the load wheel 33 in one period of rotation is stored in the memory circuit 503. On the other hand, the signal of reference point is fed to an extractor 504 through terminal 405 per revolution of the drive shaft 6 which rotates the tire (a). The extractor 504 is at the same time supplied with the output signal of the pulse pick-up which detects the rotational angle of the load wheel 33 and with the load wheel deflection signal from the memory circuit 503. The extractor 504 functions to extract the signal of deflection of the load wheel 33 which is in contact with the tire (a) with respect to a period corresponding to one revolution of the tire (a). The extracted signal is shown in analog form at (5) of FIG. 14. The deflection signal for one tire revolution is fed to a multiplier 505 where it is multiplied by a signal of spring constant which is received at terminal 406 and specified by a tire spring constant setter 328, to obtain a force variation signal 606. The waveform of the signal at this stage is shown in analog form at (7) of FIG. 14. The variation in the force which occurs between the tire (a) and load wheel 33 is fed to terminal 404 without removing the influence of runout of the load wheel 33 and, after digitization at the converter 501, fed to a subtractor 506. It is at the subtractor 506 that the erroneous component due to load wheel runout is removed from the tire variation signal by subtracting therefrom the erroneous variation signal which is simultaneously fed from the multiplier 505. The signal of radial force variations of the tire (a), if expressed in analog form, has a waveform as shown at 8 of FIG. 14, while the signal of the subtracting erroneous variations has, as shown at 9 of the same figure, a reproducible waveform. The corrected signal which appears at terminal 407 represents the variations in the radial force of the tire (a), and it is fed to a P--P (peak to peak) calculator 329. The P--P value calculated by the P--P calculator 329 is indicated on a display 320 as a variable component of the radial force in the known manner as mentioned hereinbefore.
As clear from the foregoing description of preferred embodiments, the accuracy of measurement in the tire uniformity inspecting machine can be enhanced to a significant degree by correcting the errors of measurement due to radial runout of the upper and lower rims and/or of the load wheel according to the method of the present invention. It follows that the fabrication or maintenance and service of the inspecting machine can be facilitated since it becomes possible to employ broader tolerances in the machining process. Besides, the influences owing to small bruises or other defects on the part of the rims can be eliminated by extraction of the primary harmonic component by the harmonic analysis.
Obviously, numerous additional modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein. | A method for correcting errors of measurement in a tire uniforming inspecting machine having a pair of upper and lower rims engageable with bead portions of a tire for gripping the tire securely for rotation at a predetermined position and a load wheel engageable with the circumference of the tire at one side thereof to check for variations in the radial force, including: measuring radial runout of the rims and/or load wheel to obtain an erronous deflection signal indicating the amount of radial runout of the rims and/or load wheel; obtaining and storing a primary harmonic component of the erroneous deflection signal; measuring variations in radial force of a tire rotated on the rims to obtain a radial variation signal for a period of one revolution of the tire; multiplying the erroneous deflection signal by a spring constant of the tire to obtain an erroneous variation signal; and subtracting the erroneous variation signal from the radial variation signal to eliminate influence of radial runout of the rims and/or load wheel from the measured value of the radial force of the tire. | 6 |
BACKGROUND OF THE INVENTION
This invention relates to label holders and product identification tags for merchandise suspended from a horizontally extending support hook or the like. More particularly, the present invention relates to label holders which are easily attached to and removed from product support hooks without being subject to inadvertent removal.
Label holders or product identification tags are known in the art. They are conventionally formed from a plastic sheet which is die cut into the appropriate shape so as to display product information forwardly of items suspended from a horizontally extending hook. The hook can extend from a pegboard or the like. The holder includes a mounting portion arranged to be temporarily deformed while being attached to and removed from the hook at a location adjacent to the board, an intermediate portion which projects forwardly over the support hook, and the merchandise supported thereon, and a display portion which bends downwardly from the distal end of the intermediate portion in front of the hook so as to display the desired product identification and information data.
Many known label holders are prone to lateral bending or flexing of the holder along its intermediate portion as a result of customers contacting the holder. This results in the display portion of the holder being positioned beside the suspended merchandise and not in front of it. Thus, the label holder is out of view of customers. Such bending or flexing can occur when a merchandise item is being removed from an adjacent hook by a customer who accidentally brushes against the holder. In order to deal with this problem, one known product employs longitudinally extending ribs or longitudinal rows of perforations along the intermediate portion. These are meant to promote transverse flexure of the intermediate portion of the holder into a bowed configuration to reinforce the holder against longitudinal and lateral flexure. Another known product employs side wings which are integral with and extend downwardly from the side edges or margins of the intermediate portion to impart longitudinal stiffness to the intermediate portion. The side wings are folded downwardly from the intermediate portion along longitudinally extending preformed fold lines so that the wings are located substantially perpendicular to the plane of the intermediate portion and are co-extensive in length with the intermediate portion. Other manufacturers simply use thicker sheet material for the intermediate portion in order to provide more stability and resistance to lateral bending.
Still another known product uses scalloping on downwardly turned edges of the intermediate portion to stabilize the intermediate portion. This structure also prevents packages supported on the hook from sliding forward or backward along the hook. Another way of stabilizing the intermediate portion of the label holder on the hook, while at the same time preventing movement of articles on the hook, is by means of a tab which folds downwardly out of the intermediate portion and around the hook via at least one aperture in the tab to accommodate the hook.
It is also known to provide a slot near the distal end of the intermediate portion in order to accommodate a tip of the hook. This design is meant to prevent both a drooping of the intermediate portion and lateral movement of the label holder in relation to the hook.
All of these means for preventing longitudinal flexure of the intermediate portion and a drooping of the distal end of the intermediate portion have drawbacks.
Perforations or creases which promote transverse flexure of this strip into a bowed configuration when the strip is squeezed laterally necessitate a means for perforating or creasing the intermediate portion and an additional means for squeezing the strip laterally to produce the bowed configuration. Employing wings along the sides of the intermediate portion necessitates the use of additional material for the intermediate portion. It also necessitates a means for folding down the wings before use of the label holder so that the wings can perform their stiffening function. The provision of an aperture near the distal end of the intermediate portion to accommodate a tip of the hook does not prevent a lateral motion of the intermediate portion and only prevents further sagging of the intermediate portion.
Further, it is known to provide a hanger guard which has a series of spaced ribs extending along an intermediate portion of the guard at a location rearwardly of a bubble which enshrouds the top and sides of the tip. This guard is a one piece member molded of resiliently flexible plastic. However, such a design would need to be modified to be used as a label holder. In addition, the provision of multiple spaced ribs means that the part requires a complex mold to manufacture.
Accordingly, it has been considered desirable to develop a new and improved label holder which would overcome the foregoing difficulties and others while providing better and more advantageous overall results.
BRIEF SUMMARY OF THE INVENTION
In accordance with the present invention, a label holder is provided.
More particularly in accordance with this aspect of the invention, the label holder comprises a mounting portion by which the holder is mounted on a back end of an associated hook and an elongated portion extending from the mounting portion. The elongated portion includes a centrally positioned plateau which serves as a stiffening element for the elongated portion. Also provided is a display portion connected to the elongated portion with the display portion extending in front of a tip of the associated hook.
In accordance with another aspect of the invention, a merchandise display assembly is provided.
More particularly in accordance with this aspect of the invention, the assembly comprises a support member and a hook projecting from the support member for slidably suspending associated merchandise items. The hook includes a back end which is mounted in the support member and a front end having a retainer member for preventing merchandise items from sliding off the hook. Also provided is a one piece label holder for displaying a label in front of the tip of the hook. The label holder comprises a mounting portion by which the holder is mounted on the back end of the hook and an elongated portion extending forwardly from the mounting portion. The elongated portion includes a centrally positioned stiffening plateau extending over the hook. Also provided is a display portion positioned forwardly of the tip of the hook with the display portion being connected to the elongated portion.
One advantage of the present invention is the provision of a new and improved merchandise display assembly including a label holder.
Another advantage of the present invention is the provision of a resilient one piece label holder which has a display portion positioned forwardly of a tip of a merchandise supporting hook mounted on a support structure.
Still another advantage of the present invention is the provision of a label holder made from a sheet of conventional thermoplastic material via vacuum forming.
Yet another advantage of the present invention is the provision of a label holder which installs quickly without the need to remove either the packaged product from the hook or the hook from the pegboard or other support member to which the hook is secured.
Still yet another advantage of the present invention is the provision of a one piece label holder having a mounting section, an elongated intermediate section, including a stiffening member, and a display portion. The stiffening member is a rectangular plateau--having a pair of end walls and a pair of side walls--formed in the intermediate section.
A further advantage of the present invention is the provision of a label holder which can hold a UPC (Uniform Price Code) label at the front end of a hook, either via adhesive or via a pocket formed in the label holder.
A still further advantage of the present invention is the provision of a label holder which includes a plurality of mounting constructions so as to accommodate mounting of the label holder on a variety of types of hooks such as two pronged hooks mounted in a pegboard, over the top hooks, corrugated or wire grid hooks, butterfly hooks and hooks which are accommodated in slots cut in cardboard.
Still other benefits and advantages of the present invention will become apparent to those of average skill in the art upon a reading and understanding of the following detailed specification.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention may take physical form in certain parts and arrangements of parts preferred embodiments of which will be described in detail in this specification and illustrated in the accompanying drawings which form a part hereof and wherein:
FIG. 1 is a top plan view of a label holder blank from which a label holder according to a first preferred embodiment of the present invention is formed by appropriate folding;
FIG. 2 is an enlarged cross-sectional view of the label holder of FIG. 1 along line 2--2;
FIG. 3 is an enlarged cross-sectional view of the label holder of FIG. 1 along line 3--3;
FIG. 4 is a perspective view of the label holder of FIG. 1 as it is mounted on a hook fastened on a pegboard;
FIG. 5 is a perspective view of a front portion of a label holder according to a second preferred embodiment of the present invention;
FIG. 6 is a perspective view of a front portion of a label holder according to a third preferred embodiment of the present invention;
FIG. 7 is a perspective view of a front portion of a label holder according to a fourth preferred embodiment of the present invention;
FIG. 8 is an enlarged side elevational view of a front end of the label holder of FIG. 7;
FIG. 9 is an exploded perspective view of a rear end of a label holder adapted for use with a display hook;
FIG. 10 is an exploded perspective view of a rear end of a label holder adapted for use with an over-the-top hook;
FIG. 11 is an exploded perspective view of a rear end of a label holder adapted for use with a corrugated/wire grid hook;
FIG. 12 is an exploded perspective view of a rear end of a label holder adapted for use with a butterfly hook; and,
FIG. 13 is a side elevational view of the label holder and hook of FIG. 12 in an assembled condition.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings wherein the showings are for purposes of illustrating several preferred embodiments of the invention only and not for purposes of limiting same, FIG. 4 shows a merchandise display assembly including a label holder A mounted above a hook B wherein the hook is secured to a pegboard C. While a particular type of hook B is illustrated in FIG. 4 and this hook is shown as being secured to a known type of pegboard C, it should be appreciated by those of average skill in the art that there are many varieties of known hooks other than the hook B and there are also many varieties of support structures other than the pegboard C to which such conventional merchandising support hooks can be secured.
With reference now to FIG. 1, the label holder A includes a body 10 having a mounting section 12, an intermediate section 14 separated from the mounting section by a first crease line 16 and a display section 18 separated from the intermediate section by a second crease line 20. The mounting section includes a rear edge 30 on which is provided a first indented portion 32 leading to a first aperture 34 via a first cut line 35 and a second indented portion 36 leading to a second aperture 38 via a second cut line 39. Also provided on the mounting section 12 are first, second and third spaced reinforcing ribs 40, 42 and 44. The ribs are preferably oriented perpendicular to the rear edge 30 and are so spaced that the first and third ribs 40, 44 are located outboard of the first and second apertures 34 and 38 whereas the second rib 42 is located on a tongue 46 defined between the two apertures.
The intermediate section 14 comprises a plateau 50 which is positioned out of the plane of the remainder of the intermediate section. The plateau comprises first and second side walls 52 and 54 and first and second end walls 56 and 58, as well as a top wall 60. Defined around the plateau and forming the remainder of the intermediate section is a racetrack shaped border 62. As shown in FIG. 2, the plane of the top wall 60 is located above the plane of the border 62. It is apparent from FIG. 1 that the surface area of the plateau 50 is greater than is the surface area of the border 62. It should be noted from FIG. 2 that the walls 52-58 of the plateau are angled outwardly somewhat from the top wall 60, toward border 62.
The display section 18 of the body 10 includes a planar panel 70 having a front surface 72 which is particularly adapted for mounting adhesive labels therein. It is apparent from FIG. 1 that the panel 70 is wider than is the intermediate section 14 such that a pair of side portions 74 and 76 of the panel 70 extend past the sides of the intermediate section 14. This feature enables the label holder to accept wider labels.
With reference now again to FIG. 4, the hook B includes a mounting portion 82 having a first arm 84 and a second arm 86 which are spaced from each other, a central portion 88 and a tip 90. The pegboard C includes a series of apertures 92 which are so sized and spaced as to accommodate the two arms 84 and 86 of the hook B. The label holder is mounted on the hook B such taht the mounting section 12 is located between the hook's mounting portion 82 and the pegboard; the intermediate section 14 overlies the hook central portion 88 and the display section 18 is located in front of the hook tip 90.
The plateau 50 adds stiffness to the intermediate section 14 of the label holder and prevents a sagging of the intermediate section down onto the hook B. Moreover, the plateau enhances the lateral stability of the intermediate section retarding any sideways movement of the intermediate section. The relative size of the plateau 50 in relation to the border 62 increases the resistance of the intermediate section to sagging and to sideways movement. The border region 62 preferably substantially surrounds at least three sides of the plateau. In the embodiment of FIG. 2, the border region 62 completely surrounds all four sides of the plateau 50.
Preferably, the label holder A is made from a suitable conventional thermoplastic material, such as a clear or transparent PETG. It can have a thickness of 0.015 inches if desired. The plateau is formed in the intermediate section by the known process of vacuum forming. The shape of the plateau is advantageous from the standpoint of ease of vacuum forming. The holder is then die cut out of a sheet of the thermoplastic material and folded into the appropriate shape via crease lines 16 and 20.
The label holder of the present invention can have a variety of mounting sections and display sections, as will be discussed hereafter.
With reference now to FIG. 5, a label holder D according to a second preferred embodiment of the invention is there illustrated. In this embodiment, the label holder comprises a body 100 having an intermediate portion 102 with a plateau 104. A display section 106 is spaced from the intermediate portion 102 by a crease line 108. The display section comprises a front panel 110 and a rear panel 112 which define between them a slot 114. The two panels are connected at a connecting wall 116. At least the front panel 110 is made from a clear material. A label 118 can be accommodated between the front and rear panels 110 and 112. Since the rear panel 112 is shorter than is the front panel, access can be had to the slot 114 by simply bending the rear panel backwards. Due to the resilience of the thermoplastic material from which the label holder is made, the rear panel will return to its normal position when no longer bent.
The embodiment of FIG. 5 is useful in a situation where the label is a non-adhesive label and could not be accommodated by the label holder illustrated in FIGS. 1-4. Once a label 118 is held in the slot, the label is prevented from falling out of the slot, due to gravity by the provision of the connecting wall 116.
With reference now to FIG. 6, a label holder E according to a third preferred embodiment of the invention is there illustrated. This label holder includes a body 130 having an intermediate portion 132 with a plateau 134. A display section 136 is separated from the intermediate portion via a crease line 138. The display section includes a front wall panel 140. Defined in the front wall panel are first and second cut lines 142 and 144 disposed along opposing side edges of the front panel. The display section also includes a rear panel 148 which is provided with spaced first and second tabs 150 and 152 that are so sized and located as to engage in the respective cuts 142 and 144. The front and rear panels are joined along a bottom connecting wall 154. This label holder can accommodate a non-adhesive label in such a way to lock the label in place between the front and rear panels when the tabs 150 and 152 are inserted in the cuts 142 and 144.
With reference now to FIG. 7, a fourth preferred embodiment of the present invention includes a label holder F having a body 160 with an intermediate section 162 on which is located a plateau 164. Also provided is a display section 166 which is separated from the intermediate section by a crease line 168. The display section comprises a wall panel 172 having a bottom edge 174. Spaced from the bottom edge is a U-shaped cut 176 forming a central tab 178 (FIG. 8). Spaced from a top edge 180 of the panel 172 are a second U-shaped cut 182 forming a first side tab 184 (FIG. 8) and a third Ushaped cut 186 forming a second side tab (not visible in FIG. 7 or FIG. 8). As illustrated in FIG. 8, this embodiment of the invention allows a label 192 to be held against a rear surface 194 of the panel 172 by the three tabs which have been bent out of the plane of the wall panel 172.
With reference now to FIG. 9, a label holder G according to another preferred embodiment of the present invention includes a body 200 with an intermediate section 202 and a mounting section 204 separated therefrom by a crease line 206. The mounting section 204 comprises a panel 210 having a distal edge 212 in which there is provided an indented portion 214 communicating with a cut 216 which leads to an opening 218.
The label holder is meant for use with a display hook 222 having a mounting section 224 comprising a first wall member 226 and, spaced therefrom and approximately parallel thereto, a second wall member 228. These are joined by a connecting wall 230. The connecting wall is somewhat rectangular in shape. The label holder can be mounted on the display hook 222. The opening 218 of the mounting section 204 is also somewhat rectangular in shape in order to accommodate the connecting wall 230. The mounting section can be slid onto the connecting wall via the cut 216 as the label holder is made from a suitable resilient material such as a thermoplastic.
With reference now to FIG. 10, a label holder H according to another preferred embodiment of the present invention comprises a body 240 with an intermediate section 242 separated from a mounting section 244 by a crease line 246. The mounting section comprises a panel 250 having a distal edge 252 in which there is provided a T-shaped slot 254. This label holder is meant to be employed with an over-the-top hook 260 having a mounting section 262 comprising a first wall 264 separated from a second, smaller, wall 266 by a connecting wall 268. It is apparent that the connecting wall is narrower in width than are the first and second walls. The T-shaped slot 254 of the label holder H accommodates the connecting wall 268. To this end, the label holder H is made from a suitable known thermoplastic material which can flex to allow the connecting wall 268 to pass through the narrow section of the T-shaped slot 254 and be held in the wide section thereof. In this fashion, the label holder can be held on the hook 260.
With reference now to FIG. 11, a label holder I according to another preferred embodiment of the present invention includes a body having an intermediate section 282 and a mounting section 284 which are connected along a crease line 286. The mounting section includes a panel 290 having a distal edge 292 which communicates with a T-shaped slot 294 formed in the panel.
The label holder 280 is meant to be accommodated on a corrugated wire or grid hook 300 having a mounting section 302 including a wall panel 304 and a curved finger 306 extending rearwardly from a top edge 308 of the wall panel. The T-shaped slot 294 in the mounting section 284 accommodates the curved finger 306.
With reference now to FIG. 12, another form of a label holder J according to still a further preferred embodiment of the present invention comprises a body 320 with an intermediate portion 322 and a mounting portion 324. A crease line 326 separates the two. The mounting portion comprises a panel 330 having a distal edge 332 in which is located an indented section 334 leading to a narrowed channel 336. The channel communicates with a widened slot 338 defined in the panel 330. This label holder is meant to be accommodated on a butterfly hook 340 having a mounting section 342 which comprises a first wall 344 and a second wall 346 spaced therefrom. The two walls are substantially parallel to each other and defined between them is a slot 347. A bridge or a connecting wall 348 secures the two walls 344 and 346 to each other.
With reference now to FIG. 13, the butterfly hook 340 is meant to be accommodated in a slot in a cardboard panel. The label holder, in turn, is held on the butterfly hook mounting section 342 by cooperation of first and second locking tabs 354 and 356 defined on the panel 330 with the bridge 348 of the butterfly hook 340.
The invention has been described with reference to several preferred embodiments. Obviously, modifications and alterations will occur to others upon a reading and understanding of this specification. It is intended to include all such modifications and alterations insofar as they come within the scope of the appended claims and the equivalents thereof. | A merchandise display assembly includes a support member and a hook projecting from the support member for slideably suspending associated merchandise items. The hook includes a back end which is mounted to the support member and a front end having a retainer construction for preventing merchandise items from sliding off the hook. A resilient one piece label holder is mounted on the hook for providing product information concerning merchandise items suspended on the hook. The holder includes a mounting section by which the holder is mounted on a back end of the hook. The holder also includes an intermediate section extending from the mounting section. The intermediate section includes a plateau and a border region surrounding the plateau. The plateau is located out of a plane of the border region to add stiffness to the intermediate section. A display section, which extends forwardly from the intermediate section, is so positioned and located as to extend in front of a tip of the hook. | 0 |
BACKGROUND
[0001] In many wellbore applications, connections are formed between coiled tubing and wellbore tools or other components such as subsequent sections of coiled tubing. Often, the coiled tubing connector must form a pressure tight seal with the coiled tubing. The connector end often is threaded for connecting the wellbore tool to the coiled tubing. Coiled tubing connectors can be designed to attach and seal to either the inside or the outside of the coiled tubing.
[0002] Examples of internal connectors include roll-on connectors, grapple connectors and dimple connectors. Roll-on connectors align circumferential depressions in the coiled tubing with preformed circumferential grooves in the connector to secure the connector to the coiled tubing in an axial direction. Grapple connectors utilize internal slips that engage the inside of the coiled tubing to retain the coiled tubing in an axial direction. Dimple connectors rely on a dimpling device to form dimples in the coiled tubing. The dimples are aligned with preformed pockets in the connector to secure the connector to the coiled tubing both axially and torsionally. Elastomeric seals can be used to provide pressure integrity between the connector and the coiled tubing. However, internal connectors constrict the flow area through the connector which can limit downhole tool operations.
[0003] Examples of external connectors include dimple connectors, grapple connectors and threaded connectors. This type of dimple connector relies on a dimpling device to create dimples in the coiled tubing. The dimple connector comprises set screws that are aligned with the dimples in the coiled tubing and threaded into the dimples. The set screws provide both an axial and a torsional connectivity between the connector and the coiled tubing. External grapple connectors use external slips to engage the outside of the coiled tubing for providing axial connectivity to the tubing. External threaded connectors rely on a standard pipe thread which engages a corresponding standard external pipe thread on the end of the coiled tubing. The threaded connection provides axial connectivity, but the technique has had limited success due to the normal oval shape of the coiled tubing which limits the capability of forming a good seal between the connector and the coiled tubing. External connectors, in general, are problematic in many applications because such connectors cannot pass through a coiled tubing injector or stripper. This limitation requires that external connectors be attached to the coiled tubing after the tubing is installed in the injector.
SUMMARY
[0004] The present invention comprises a system and method for forming coiled tubing connections, such as connections between coiled tubing and downhole tools. A connector is used to couple the coiled tubing and a downhole tool by forming a secure connection with an end of the coiled tubing. The connector comprises a unique engagement end having engagement features that enable a secure, rigorous connection without limiting the ability of the connector to pass through a coiled tubing injector. The connector design also enables maximization of the flow area through the connector. In some embodiments, additional retention mechanisms can be used to prevent inadvertent separation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] Certain embodiments of the invention will hereafter be described with reference to the accompanying drawings, wherein like reference numerals denote like elements, and:
[0006] FIG. 1 is a front elevation view of a coiled tubing connection system deployed in a wellbore, according to one embodiment of the present invention;
[0007] FIG. 2 is an orthogonal view of a bayonet style connector that can be used in the system illustrated in FIG. 1 , according to an embodiment of the present invention;
[0008] FIG. 3 is another view of the connector illustrated in FIG. 2 , according to an embodiment of the present invention;
[0009] FIG. 4 is an orthogonal view of the connector coupled to an end of coiled tubing that has been formed with protrusions to engage the connector, according to an embodiment of the present invention;
[0010] FIG. 5 is an alternate embodiment of the connector illustrated in FIG. 2 , according to another embodiment of the present invention;
[0011] FIG. 6 is a cross-sectional view of an alternate embodiment of the connector threadably coupled with a coiled tubing end, according to an embodiment of the present invention;
[0012] FIG. 7 is a cross-sectional view of a coiled tubing end that has been expanded and then threaded internally for engagement with the connector, according to an embodiment of the present invention;
[0013] FIG. 8 is a view similar to that of FIG. 7 but showing a connector engaged with the coiled tubing end, according to an embodiment of the present invention;
[0014] FIG. 9 is a cross-sectional view of a coiled tubing end that has been swaged radially inward and threaded for engagement with the connector, according to an embodiment of the present invention;
[0015] FIG. 10 is a view similar to that of FIG. 9 but showing a connector engaged with the coiled tubing end, according to an embodiment of the present invention;
[0016] FIG. 11 is a cross-sectional view of a coiled tubing end that has been swaged radially and threaded externally for engagement with the connector, according to an embodiment of the present invention;
[0017] FIG. 12 is a view similar to that of FIG. 11 but showing the connector engaged with the coiled tubing end, according to an embodiment of the present invention;
[0018] FIG. 13 is a flow chart illustrating a methodology for engaging a threaded connector with coiled tubing at a well site, according to an embodiment of the present invention;
[0019] FIG. 14 is a flow chart illustrating a more detailed methodology for engaging a threaded connector with coiled tubing at a well site, according to an embodiment of the present invention;
[0020] FIG. 15 is an orthogonal view of a retention system for rotationally retaining a connector with respect to coiled tubing, according to an embodiment of the present invention;
[0021] FIG. 16 is another embodiment of a retention system for rotationally retaining a connector with respect to coiled tubing, according to an embodiment of the present invention;
[0022] FIG. 17 is another embodiment of a retention system for rotationally retaining a connector with respect to coiled tubing, according to an embodiment of the present invention;
[0023] FIG. 18 is a view similar to that of FIG. 17 but showing the retention mechanism in a locked position, according to an embodiment of the present invention;
[0024] FIG. 19 is another embodiment of a retention system for rotationally retaining a connector with respect to coiled tubing, according to an embodiment of the present invention;
[0025] FIG. 20 is a view similar to that of FIG. 19 but showing the retention mechanism in a locked position, according to an embodiment of the present invention;
[0026] FIG. 21 is another embodiment of a retention device for rotationally retaining a connector with respect to coiled tubing, according to an embodiment of the present invention;
[0027] FIG. 22 illustrates the retention device of FIG. 21 incorporated into a retention system between a coiled tubing end and a wellbore component, according to an embodiment of the present invention;
[0028] FIG. 23 illustrates another embodiment of a retention device, according to an embodiment of the present invention; and
[0029] FIG. 24 illustrates a fixture used to form depressions in the coiled tubing for engagement with devices, such as those illustrated in FIGS. 2 and 5 , according to an embodiment of the present invention.
DETAILED DESCRIPTION
[0030] In the following description, numerous details are set forth to provide an understanding of the present invention. However, it will be understood by those of ordinary skill in the art that the present invention may be practiced without these details and that numerous variations or modifications from the described embodiments may be possible.
[0031] The present invention relates to a system and methodology for forming coiled tubing connections. The coiled tubing connections typically are formed between coiled tubing and a well tool for use downhole, however the coiled tubing connections can be formed between coiled tubing and other components, such as subsequent sections of coiled tubing. The coiled tubing connections are formed with a connector that is of similar outside diameter to the coiled tubing and uniquely designed to provide a secure, rigorous connection without limiting the ability of the connector to pass through a coiled tubing injector. Additionally, some coiled tubing connection embodiments utilize a retention mechanism to further guard against inadvertent separation of the coiled tubing connection.
[0032] Referring generally to FIG. 1 , a well system 30 is illustrated according to one embodiment of the present invention. The well system 30 comprises, for example, a well intervention system 32 deployed for use in a well 34 having a wellbore 36 drilled into a reservoir 38 containing desirable fluids, such as hydrocarbon based fluids. In many applications, wellbore 36 is lined with a wellbore casing 40 having perforations 42 through which fluids can flow between wellbore 36 and the reservoir 38 . Well intervention system 32 can be formed in a variety of configurations with a variety of components depending on the specific well intervention application for which it is used. By way of example, well intervention system 32 comprises a well tool 44 located downhole and coupled to a coiled tubing 46 by a connector 48 . Connector 48 is securely attached to coiled tubing 46 . The connection is sized to pass through a coiled tubing injector when rigging up to the well. The tool 44 is securely attached to the connector 48 after the connector is installed through the injector and well intervention system 32 is run downhole.
[0033] One embodiment of connector 48 is illustrated in FIGS. 2 and 3 . In this embodiment, connector 48 comprises a midsection 50 , a first engagement end or region 52 extending axially from the midsection 50 , and a second engagement end or region 54 extending from midsection 50 in a direction generally opposite first engagement region 52 . First engagement region 52 is designed for engagement with coiled tubing 46 , and second engagement region 54 is designed for engagement with a component, such as well tool 44 . As illustrated, midsection 50 may be radially expanded, i.e. comprise a greater diameter, relative to engagement regions 52 and 54 .
[0034] The first engagement region 52 is sized for insertion into coiled tubing 46 and comprises one or more bayonet slots 56 recessed radially inwardly into engagement region 52 . This form of engagement region can be referred to as a breech lock engagement region. Each bayonet slot comprises a generally longitudinal slot portion 58 intersected by one or more generally transverse slot portions 60 . Transverse slot portions 60 may be substantially linear, curved, J-shaped, helical, or formed in other suitable shapes. Additionally, one or more seals 62 , such as elastomeric seals, may be mounted on engagement region 52 in a location placing the seals 62 between the engagement region 52 and coiled tubing 46 when engagement region 52 is inserted into coiled tubing 46 . Seals 62 may comprise O-rings, poly-pak seals or other seals able to form a sealed region between the coiled tubing 46 and connector 48 . Connector 48 further comprises a hollow interior 64 that maximizes flow area for conducting well fluids therethrough, as best illustrated in FIG. 3 .
[0035] The second engagement region 54 may have a variety of shapes and configurations depending on the specific type of well tool 44 or other component to be connected to coiled tubing 46 via connector 48 . By way of example, engagement region 54 is a tubular threaded end sized for insertion into and threaded engagement with a corresponding receptacle of the component, e.g. well tool 44 . One or more seals 66 , such as O-rings, poly-pak seals or other suitable seals can be mounted around the engagement region 54 , as illustrated, to form a fluid seal with well tool 44 .
[0036] The coiled tubing 46 is formed with one or more protrusions 68 that are sized and spaced to engage bayonet slots 56 , as further illustrated in FIG. 4 . Protrusions 68 extend radially inward into the interior of coiled tubing 46 and may be formed with pins, bolts, weldments, externally formed depressions or other suitable elements that protrude inwardly. In the embodiment illustrated, protrusions 68 are formed by applying localized pressure at selected locations along the exterior of coiled tubing 46 to create depressions that extended inwardly into the interior of coiled tubing 46 . By way of example, the depressions can be formed in coiled tubing 46 with a screw type forming tool (see FIG. 24 ). Additionally, a depression forming mandrel can be placed inside the coiled tubing while the depressions are formed to accurately control the final shape of the protrusions 68 extending into the interior of the coiled tubing 46 . In other applications, however, the depressions can be formed in the tubing without an inner mandrel or they can be formed while the coiled tubing is positioned directly on the connector 48 . Regardless of the method of formation, the protrusions 68 are located such that longitudinal slot portions 58 of bayonet slots 56 can be aligned with the protrusions. The protrusions 68 are then moved along longitudinal slot portions 58 as engagement region 52 moves into the interior of coiled tubing 46 . Once connector 48 is axially inserted, the connector 48 and coiled tubing 46 are rotationally twisted relative to each other to move the plurality of protrusions into the generally transverse slot portions 60 .
[0037] After the coiled tubing 46 and connector 48 are joined through the relative axial and rotational movement, a retention mechanism 70 may be used to rotationally secure the coiled tubing protrusions 68 within their corresponding bayonet slots 56 . One example of retention mechanism 70 comprises an interference mechanism, e.g. simple detents 72 (see FIG. 2 ), that hold protrusions 68 in transverse slot portions 60 once protrusions 68 are inserted longitudinally along longitudinal slot portions 58 and rotated into transverse slot portion 60 . Another example of retention mechanism 70 (see FIG. 4 ) comprises a snap ring, e.g. a C-ring, member 74 that may be positioned within a corresponding slot 76 located, for example, circumferentially along midsection 50 of connector 48 . C-ring member 74 further comprises a transverse pin 78 that is positioned in corresponding recesses 80 , 82 of connector 48 and coiled tubing 46 , respectively, when C-ring member 74 is pressed into slot 76 . A variety of other retention mechanisms 70 also can be used, some of which are discussed in greater detail below.
[0038] In the embodiment illustrated in FIGS. 2-4 , each bayonet slot 56 is illustrated as having two transverse slot portions 60 for receiving corresponding pairs of protrusions 68 . However, the bayonet slots 56 can be designed in other configurations with different numbers of longitudinal slot portions 58 and a different numbers of transverse slot portions 60 associated with each longitudinal slot portion. As illustrated in FIG. 5 , for example, each longitudinal slot portion 58 is intersected by four transverse slot portions 60 . Additionally, each transverse slot portion 60 has a generally J-shape as opposed to the linear shape illustrated best in FIG. 2 . The embodiment illustrated in FIG. 5 provides one example of other potential bayonet slot configurations that can be used in coupling connector 48 with coiled tubing 46 .
[0039] In another embodiment, engagement region 52 of connector 48 comprises a threaded portion 84 having threads 86 for engaging a corresponding coiled tubing threaded portion 88 having threads 90 , as illustrated in FIG. 6 . In the embodiment illustrated, threads 86 are formed externally on engagement region 52 of connector 48 , and the corresponding threads 90 are formed on the interior end of coiled tubing 46 . The threads 86 and 90 are designed to absorb substantial axial loading. In some embodiments, an additional seal 92 , such as an elastomeric seal, also may be deployed between engagement region 52 of connector 48 and the surrounding coiled tubing 46 . Examples of seals 92 include O-ring seals, poly-pak seals or other seals able to form a seal between the coiled tubing 46 and connector 48 . The seal area on either side of the elastomeric seal 92 is designed to form a metal to metal seal. In addition, threads that form a metal to metal seal can be used. Regardless, the threads also are selected such that they may be formed at the well site as opposed to being pre-manufactured in a factory environment. Examples of suitable threads include locking tapered threads, such as the Hydril 511 thread, the Tapered Stub Acme thread, the Tapered Buttress thread, and certain straight threads. The interference of the threads also can be designed such that the threads are sacrificial threads. In other words, once connector 48 and coiled tubing 46 are threaded together, the threads are plastically deformed and typically unusable for any subsequent connections, i.e. sacrificed, and the connector cannot be released from the coiled tubing.
[0040] The connectors illustrated herein enable preparation of the coiled tubing and formation of rigorous, secure connections while at the well site. Whether the connector utilizes bayonet slots or threads, the connection with coiled tubing 46 can be improved by preparing the coiled tubing end for connection. For example, the strength of the connection and the ability to form a seal at the connection can be improved by rounding the connection end of the coiled tubing through, for example, a swaging process performed at the well site. As illustrated in FIGS. 7-12 , the coiled tubing 46 can be prepared with an internal swage or an external swage.
[0041] Referring first to FIGS. 7 and 8 , an end 94 of coiled tubing 46 is illustrated after being subjected to an internal swage that creates a swage area 96 . Swage area 96 results from expanding the coiled tubing 46 at end 94 to a desired, e.g. maximum, outside diameter condition. The coiled tubing end 94 is caused to yield during swaging such that end 94 is near round and the outside diameter is formed to the desired, predetermined diameter. The interior of end 94 can then be threaded with threads 90 for engagement with connector 48 , as illustrated in FIG. 8 . In addition to rounding and preparing end 94 for a secure and sealing engagement with connector 48 , the internal swaging can be used to maximize the flow path through connector 48 . Furthermore, the swaging enables a single size connector 48 to be joined with coiled tubing sections having a given outside diameter but different tubing thicknesses. An external rounding fixture also can be used to round the coiled tubing for threading.
[0042] Alternatively, the coiled tubing end 94 can be prepared via external swaging in which, for example, an external swage is used to yield the coiled tubing in a radially inward direction. In this embodiment, the coiled tubing 46 can be yielded back to nominal outside diameter dimensions. As illustrated in FIGS. 9 and 10 , the external swaging creates a swage area 98 that is yielded inwardly and rounded for engagement with connector 48 . As with the previous embodiment, threads 90 can be formed along the interior of swaged end 94 for a rigorous and sealing engagement with connector 48 , as best illustrated in FIG. 10 . In another alternative, swage area 98 can be created, and threads 90 can be formed on the rounded exterior end of coiled tubing 46 , as illustrated in FIGS. 11 and 12 . In this embodiment, threads 86 of connector 48 are formed on an interior of engagement region 52 , as best illustrated in FIG. 12 .
[0043] The methodology involved in rounding and otherwise preparing the coiled tubing for attachment to connector 48 enables field preparation of the coiled tubing at the well site. An example of one methodology for forming connections at a well site can be described with reference to the flowchart of FIG. 13 . As illustrated in block 100 of the flowchart, the coiled tubing 46 and connectors 48 initially are transported to a well site having at least one well 34 . Once at the well site, the end 94 of the coiled tubing 46 is swaged, as illustrated by a block 102 . The swaging can utilize either an internal swage or an external swage, depending on the application and/or the configuration of connector 48 . The swaging process properly rounds the coiled tubing for a secure, sealing engagement with the connector. In some applications, the swaging portion of the process requires that the coiled tubing seam be removed. When using an internal swage, for example, the coiled tubing seam formed during manufacture of the coiled tubing can be removed with an appropriate grinding tool.
[0044] If connector 48 comprises a threaded portion 84 along its engagement region 52 , the threads 86 are cut into coiled tubing end 94 , as illustrated by block 104 . The threads can be cut at the well site with a tap having an appropriate thread configuration to form the desired thread profile along either the interior or the exterior of coiled tubing end 94 . It should be noted that if connector 48 comprises an engagement region having bayonet slots 56 , the swaging process can still be used to properly round the coiled tubing end 94 and to create the desired tubing diameter for a secure, sealing fit with the breech lock style connector. Once the end 94 is prepared, engagement region 52 of connector 48 is engaged with the coiled tubing. When using a threaded engagement region, the connector 48 is to threadably engaged with the coiled tubing 46 , as illustrated by block 106 . The connector 48 and coiled tubing 46 are then continually threaded together until an interfering threaded connection is formed, as illustrated by block 108 . The interfering threaded connection forms a metal-to-metal seal and a rigorous connection able to withstand the potential axial loads incurred in a downhole application. Of course, the well tool 44 or other appropriate component can be coupled to engagement region 54 according to the specific coupling mechanism of the well tool prior to running the well tool and coiled tubing downhole.
[0045] FIG. 14 illustrates a slightly more detailed methodology of forming connections at a well site. In this embodiment, the coiled tubing 46 and connectors 48 are initially transported to the well site, as illustrated by block 110 . The connection end of the coiled tubing 46 is then swaged, as described above and as illustrated by block 112 . In this particular embodiment, an internal interference thread is cut into the interior of the rounded connection end 94 with a tap having an appropriate thread configuration, as illustrated by block 114 . The cut interference threads are then finished with a second tap, as illustrated by block 116 . A supplemental seal, such as elastomeric seal 92 , is located between the connector 48 and the coiled tubing 46 , as illustrated by block 118 . The connector 48 and the coiled tubing 46 are then threadably engaged, as illustrated by block 120 . In this example, the connector 48 and the coiled tubing 46 are threaded together until a sacrificial threaded connection is formed, as illustrated by block 122 . The embodiments described with reference to FIGS. 13 and 14 are examples of methodologies that can be used to form stable, rigorous, sealed connections at a well site. However, alternate or additional procedures can be used including additional preparation of the coiled tubing end, e.g. chamfering or otherwise forming the end for a desired connection. Additionally, the connector 48 can be torsionally, i.e. rotationally, locked with respect to the coiled tubing 46 and/or the well device 44 via a variety of locking mechanisms, as described more fully below.
[0046] Depending on the type of engagement regions 52 and 54 used to engage the coiled tubing 46 and well tool 44 , respectively, the use of retention mechanism 70 may be desired to lock the components together and prevent inadvertent separation. In addition to the examples of retention mechanism 70 illustrated in FIGS. 2 and 4 , another embodiment of retention mechanism 70 is illustrated in FIG. 15 . In this embodiment, a snap ring member 124 , such as a C-ring, is designed to snap into a corresponding groove 126 formed, for example, in connector 48 . However, groove 126 also can be formed in coiled tubing 46 or well tool 44 . The snap ring member 124 further comprises a transverse pin 128 , such as a shear pin. When snap ring member 124 is properly placed into groove 126 , pin 128 extends through corresponding recesses or castellations 130 , 132 formed in connector 48 and the adjacent component, e.g. coiled tubing 46 , respectively. In the embodiment illustrated in FIG. 15 , connector 48 comprises a plurality of castellations 130 circumferentially spaced, and coiled tubing 46 comprises a plurality of corresponding castellations 132 also circumferentially spaced. In one specific example, 15 castellations 130 are machined between groove 126 and the end of midsection 50 adjacent coiled tubing 46 . In this same example, 12 corresponding castellations are machined into the corresponding end 94 of coiled tubing 46 . This particular pattern of castellations provides matching notches within plus or minus one degree around the circumference of the connector. When pin 128 is disposed within corresponding castellations, the connected components are prevented from rotating with respect each other and are thus retained in a connected position, regardless of whether the connection is formed with bayonet slots 56 or threads 86 . This method can be used for all tool joint connections within the downhole tool.
[0047] Another retention mechanism 70 is illustrated in FIG. 16 . In this embodiment, one or more split ring locking mechanisms 134 can be used to connect sequentially adjacent components, such as coiled tubing 46 , connector 48 and well tool 44 . Each split ring locking mechanism 134 comprises a separate ring sections 136 that can be coupled together around the connection region between adjacent components. The split ring locking mechanism 134 comprises, for example, an internal thread that can be used to pull the adjacent components together when torque is applied to the split ring locking mechanism. Corresponding castellations 138 may be machined into each split ring locking mechanism 134 and an adjacent component to prevent unintended separation of the components, as discussed above. For example, a plurality of castellations can be machined into both the split ring locking mechanism 134 and the adjacent component. A snap ring member 124 can be positioned to prevent the split ring 134 from loosening, thereby securing the adjacent components. By way of specific example, each split ring locking mechanism 134 may comprise a pair of castellations, and each of adjacent component may comprise 12 castellations to facilitate alignment of the corresponding castellations for placement of the snap ring member 124 . In this type of embodiment, the adjacent components, e.g. connector 48 and well tool 44 , can be designed with connector ends having corresponding splines that mate with each other when the adjacent components are initially engaged. The one or more split ring locking mechanisms 134 are used to retain the adjacent components in this engaged position.
[0048] Another embodiment of the split ring locking mechanism 134 is illustrated in FIGS. 17 and 18 . In this embodiment, the split ring locking mechanism 134 comprises a split ring portion 140 and a wedge ring portion 142 . The wedge ring portion 142 has a mechanical stop 144 and one or more inclined or ramp regions 146 that cooperate with corresponding inclined or ramp regions 148 of split ring portion 140 . With this type of split ring, the adjacent components are assembled as described above with reference to FIG. 16 , and the split ring 134 is threaded onto an adjacent component until contacting a component shoulder and “shouldering out” on the inside of the connection. The ramp regions 146 , 148 of the wedge ring portion 142 and the split ring portion 140 interfere with each other such that the wedge ring portion 142 rotates with the split ring portion 140 . When the connection is tight, the split ring portion 140 is held in position and the wedge ring portion 142 is turned in the tightening direction. The ramp regions 146 force wedge ring portion 142 away from split ring portion 140 (see FIG. 18 ) and into a shoulder of the adjacent component. Friction holds the wedge ring portion 142 in place. If an external force acts on the split ring locking mechanism 134 in a manner that would tend to loosen the connection, ramp regions 146 are further engaged, thereby tightening the wedge and preventing the split ring mechanism from loosening.
[0049] In another alternate embodiment, retention mechanism 70 may comprise a belleville washer or wave spring 150 positioned to prevent inadvertent loosening of adjacent components, such as connector 48 and coiled tubing 46 . As illustrated in FIGS. 19 and 20 , belleville washer 150 may be positioned between a shoulder 152 of a first component, e.g. connector 48 , and the mating end of the adjacent component, e.g. coiled tubing 46 . When the connection is tightened, such as by threading connector 48 into coiled tubing 46 as described above, the belleville washer 150 is transitioned from a relaxed state, as illustrated in FIG. 19 , to a flattened or energized state, as illustrated in FIG. 20 . The belleville washer 150 may be designed so the washer is fully flattened when the desired torque is applied to the connection. In the event a large axial load is applied to the connection, loosening of the connection is prevented by the washer due to the highly elastic nature of the belleville washer 150 relative to the elasticity of the connected components.
[0050] Another embodiment of retention mechanism 70 is illustrated in FIGS. 21 and 22 . In this embodiment, a key 154 is used in combination with a split ring locking mechanism 134 that may be similar to the design described above with reference to FIG. 16 . Prior to installation, key 154 is slid into a corresponding slot 156 formed in the split ring locking mechanism 134 . The corresponding slot 156 may have one or more undercut regions 158 with which side extensions 160 of key 154 are engaged as key 154 is moved into slot 156 . The side extensions 160 allow the key to move back and forth in slot 156 but prevent the key 154 from falling out of slot 156 once the split ring locking mechanism 134 is engaged with adjacent components.
[0051] The key 154 retains adjacent components in a rotationally locked position by preventing rotation of split ring locking mechanism 134 in the same manner as pin 128 of the snap ring member 124 described above with reference to FIGS. 15 and 16 . In operation, the split ring locking mechanism 134 is rotated until sufficiently tight and until the key 154 can be moved into an aligned castellation 138 of an adjacent component, as best illustrated in FIG. 22 . The key 154 is then slid into the aligned castellation until it engages both the split ring locking mechanism 134 and the adjacent component. In this position, key 154 prevents relative rotation between the split ring locking mechanism and the adjacent component. The key 154 may be prevented from sliding back into slot 156 by an appropriate blocking member 162 , such as a set screw positioned behind the key after the key is moved into its locking position. The set screw 162 prevents the key 154 from moving fully back into slot 156 until removal of the set screw. It should be noted that many of these retention mechanisms also can be used in combination. For example, interlocking castellations 130 , 132 can be combined with belleville washers 150 , keys 154 , wedge ring portions 142 , or other locking devices in these and other combinations.
[0052] Another embodiment of retention mechanism 70 is illustrated in FIG. 23 . In this embodiment, a jam nut 164 prevents inadvertent separation of adjacent components, such as separation of coiled tubing 46 from an adjacent component. The jam nut 164 can be used to force coiled tubing 46 and specifically protrusions 68 into more secure engagement with slots 56 , e.g. against the wall surfaces forming slots 56 . In one embodiment, jam nut 164 is used to securely move protrusions 68 into a J-slot portion of each slot 56 . A split ring 134 may be used with the connector 48 to prevent loosening of jam nut 164 , thereby ensuring a secure connection. It should be further noted that additional retention mechanisms can be used for other types of connections, such as threaded connections. For example, threaded connections can be secured with a thread locking compound, such as a Baker™-lock and loctite™ thread locking compound.
[0053] As briefly referenced above, a forming tool 166 can be used to form depressions in the exterior of coiled tubing 46 that result in inwardly directed protrusions 68 , as illustrated in FIG. 24 . The forming tool 166 comprises a tool body 168 with an interior, longitudinal opening 170 sized to receive an end of the coiled tubing 46 therein. A mandrel 172 can be inserted into the interior of coiled tubing 46 to support the coiled tubing during formation of protrusions 68 . Additionally, a plurality of tubing deformation members 174 are mounted radially through tool body 168 . The tubing deformation members 174 are threadably engaged with tool body 168 such that rotation of the tubing deformation members drives them into the coiled tubing to form inwardly directed protrusions 68 . Mandrel 172 can be designed with appropriate recesses to receive the newly formed protrusions 68 , as illustrated.
[0054] The connectors described herein can be used to connect coiled tubing to a variety of components used in well applications. Additionally, the unique design of the connector enables maximization of flow area while maintaining the ability to pass the connector through a coiled tubing injector. The connector and the methodology of using the connector also enable preparation of coiled tubing connections while at a well site. Additionally, a variety of locking mechanisms can be combined with the connector, if necessary, to prevent inadvertent disconnection of the connector from an adjacent component. The techniques discussed above can be used for all tool joints in a downhole tool string.
[0055] Accordingly, although only a few embodiments of the present invention have been described in detail above, those of ordinary skill in the art will readily appreciate that many modifications are possible without materially departing from the teachings of this invention. Such modifications are intended to be included within the scope of this invention as defined in the claims. | A coiled tubing connection system is used in a well. A connector having an engagement end is used to couple a wellbore device to the end of a coiled tubing. The connector is spoolable, and the engagement end comprises engagement features that facilitate formation of a connection that is dependable and less susceptible to separation. | 4 |
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a circuit, suitable for CMOS technology, for the fast driving of a capacitive load. A typical application of the circuit according to the invention is in the driving of the output nodes of an integrated circuit for which a high switching speed is required, such as in a memory storage device.
BACKGROUND OF THE INVENTION
When the output buffer of an integrated circuit switches the voltage on the output node in order to change a given logic level, an inductive extra voltage is generated on the power supply lines. This extra voltage is determined by the product of the parasitic inductance L of the line (which is typically comprised between a few nH and over 10 nH) and the time derivative of the current I out supplied by the buffer in order to rapidly charge or discharge the load capacitor. This extra voltage (often termed "switching noise") can reach such values as to compromise the correct operation of the integrated circuit to which the buffer belongs. The problem is more serious in the case where several nodes in the same integrated circuit have the same driving requirements in terms of speed and capacitive load (for example the data outputs in a memory circuit), and there is the potential for simultaneous logic switching on a plurality of these nodes.
FIG. 1 shows a known output circuit. The block indicated schematically by the broken line, contains a P-channel pull-up transistor MU' and an N-channel pull-down transistor MD' which have their sources connected to power supply lines V DDI , and V SSI , respectively. The output circuit includes a common node which is connected to the output node OUT to be switched.
The internal power supply lines are connected to respective external power supplies V DD and V SS through parasitic inductances L VDD and L VSS . The transistors MU' and MD' are controlled by respective UPN and DW gate signals which can assume a low level (or "0"), typically equal to 0 V, or a high level (or "1"), typically 5 V. Each of the two signals shifts from one level to the other very rapidly, so as to have a low output voltage switching time (hereinafter more simply termed "switching time").
The two signals UPN and DW often coincide, but can be different in order to switch off both transistors. Switching off both transistors places the output node OUT in a high-impedance state ("tristate" operation). Additionally, this state minimizes the flow of direct current between V DD , and V SS , by means of appropriate timings of the signals.
In order to switch the output voltage V OUT , for example from high to low, the two signals UPN and DW are both raised high. The transistor MU' switches off, and the transistor MD' starts to conduct, with a consequent sudden variation in the current which it delivers.
Current flows in the parasitic inductance L VSS . This current flow creates switching noise. If the delivered current is reduced in order to reduce switching noise, the consequence is an undesirable increase in switching time.
A similar problem occurs when the opposite switching of the output voltage is performed.
Various proposals have been offered to solve the problem of switching noise without incurring excessive penalties in switching time. For example, the European patent application No. 284,357, filed on Mar. 22, 1988 in the name of S. Oshima et al., entitled "Semiconductor Integrated Circuit Having a Data Output Buffer Circuit", proposes to separate the pads and the metal lines for the power supply of the internal circuitry of the device and for the power supply of the buffer. These separated pads and metal lines would reduce the noise induced on the power supply lines of the internal circuitry of the integrated circuit during the switchings of the output voltage by reducing the greatest contribution to the parasitic inductance of a line; that is, by reducing the inductance given by the wire which connects the pad and the lead (termed "bonding wire"). This refinement may be useful but it is not a complete or substantially complete solution to the problem.
Another known method for reducing switching noise consists of introducing appropriate offsets among the switchings of different output nodes in order to prevent the adding of current variations related to different nodes. This solution is most effective in the case of simultaneous switching of a plurality of nodes.
Another method consists in replacing the pull-up and pull-down transistors of the buffer with a plurality of transistors in parallel, and by appropriately offsetting the switchings of the various transistors of an individual buffer (see D.T. Wong et al., "An 11-ns 8K×18 CMOS Static RAM with 0.5-μm Devices", IEEE J. Solid-State Circuits, vol. SC-23, No. 5, Oct. 1988, pages 1095-1103). These methods have the disadvantages of depending heavily on the manufacturing process and require in any case accurate experimental characterization.
Methods for preloading the output node at a level intermediate between V SS and V DD before performing actual switching are also well-known in the art (see for example T. Wada et al., "A 34-ns 1-Mbit CMOS SRAM Using Triple Polysilicon", IEEE J. Solid-State Circuits, vol. SC-22, No. 5, Oct. 1987, pages 727-732, or H. Okuyama et al., "A 7-ns 32K=8 CMOS SRAM", IEEE J. Solid-State Circuits, vol. SC-23, No. 5, Oct. 1988, pages 1054-1059). In this manner, the voltage change on the node when actual switching occurs is obviously reduced. Additionally, this method reduces the time variation of the associated current. This method is useful in those cases in which there is a dead time between the request for a new datum and its reading, for example in memory circuits.
Similarly, a method is described in the European patent application No. 271,331, filed on Dec. 9, 1987 in the name of S. Takayasu, entitled "Semiconductor Integrated Circuit". In this method, the output node is preloaded only when the initial output level is "1" and is also performed when an input value of an electronic circuit appears to be a high level (for example 2.5 V). The output node is not preloaded if the initial output level is "0" because this situation is considered non-critical.
All of the above described preloading methods reduce the extent of the problem but do not eliminate the problem. Furthermore, some of these methods may only be used with some types of device, such as memories.
Another method in widespread use for reducing switching noise consists of controlling the driving of the pull-up and pull-down transistors. The driving of the transistors is controlled such that the peak value of the time derivative dI out /dt of the current I out supplied by said transistors is as low as possible compatibly with the switching speed requirements. For example, it has been proposed to drive the gate electrodes of the output pull-up and pull-down transistors through a resistor which is arranged in series to said electrodes or to the positive and/or negative power supply of the logic gates which drive said electrodes. These resistors slow down, with a preset time constant, the rise and drop of the voltage applied to said electrodes; and, thus reduce the sudden variation in the current delivered by the buffer (see for example European patent application No. 251,910, filed on Jun. 25, 1987 in the name of M. Naganuma, entitled "CMOS Output Buffer Circuit"; or K.L. Wang et al., "A 21-ns 32K=8 CMOS Static RAM with a Selectively Pumped p-Well Array", IEEE J. Solid-State Circuits, vol. SC-22, No. 5, Oct. 1987, pages 704-711).
In other cases it has been proposed to perform this control of the driving voltages by means of active networks (see for example W.C.H. Gubbels et al., "A 40-ns/1OOpF Low-Power Full-CMOS 256K (32K×8) SRAM", IEEE J. Solid-State Circuits, vol. SC-22, No. 5, Oct. 1987, pages 741-747; or S.T. Chu et al., "A 25-ns Low-Power Full-CMOS 1-Mbit (128K×8) SRAM", IEEE J. Solid-State Circuits, vol. SC-23, No. 5, Oct. 1988, pages 1078-1084).
However, the above mentioned methods for controlling the driving of the transistors of the buffer have led to solutions which predominantly depend on the manufacturing process. Dependence on the manufacturing process necessarily leads to the need to comply with rather wide design margins. For instance, a design margin might include the setting for the maximum peak value of the time derivative of the output current. Compliance with these wide design margins result in the reduction of the switching speed of the output buffer. Thus, there is a need for a fast driving current generator which minimizes switching noise at high switching speeds even with heavy capacitive loads.
SUMMARY OF THE INVENTION
The aim of the invention is to provide a current generation circuit for the fast driving of even heavy capacitive loads, which minimizes the switching noise due to the parasitic inductance coils on the power supply lines while still ensuring a high switching speed. Another object of the invention is to provide such a circuit so as to allow the circuit designer to set the best compromise between switching speed and switching noises.
The invention achieves this aim, and other objects and advantages as will become apparent hereinafter, with a fast capacitive-load driving circuit for integrated circuits, particularly memories. The invention comprises at least one pull-down output transistor which is suitable for driving capacitive load. Additionally, the invention comprises a ramp voltage generation circuit, a voltage/current conversion circuit, and a current-mirroring circuit. The ramp voltage generation circuit can be controlled by a timing signal in order to generate a voltage which varies in time in a linear manner during a desired interval. The voltage/current conversion circuit is driven by the output of said ramp voltage generation circuit and is suitable for generating a current which is proportional to said voltage. Further, the current-mirroring circuit is driven by the output of the voltage/current conversion circuit and mirrors the current generated by the conversion circuit in the pull-down output transistor by a preset mirroring ratio.
Another embodiment of a fast capacitive-load driving circuit for integrated circuits, particularly memories, includes at least one pull-down output transistor and a pull-up output transistor which are suitable for driving said capacitive load. This embodiment includes a ramp voltage generation circuit and a voltage/current conversion. The voltage-generation circuit can be controlled by a timing signal in order to generate a voltage which varies in time in a linear manner during a desired interval. The voltage/current conversion circuit is driven by the output of said ramp voltage-generation circuit and is suitable for generating a current which is proportional to the voltage. The current-mirroring circuit is driven by the output of said voltage/current conversion circuit and mirrors the current from the voltage/current conversion circuit in the pull-down output transistor with a preset mirroring ratio when a first control signal is present. The current-mirroring circuit is also driven by the output of said voltage/current conversion circuit and mirrors the current from the voltage/current conversion circuit in the pull-up output transistor with a selected mirroring ratio when a second control signal is present.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is now described in greater detail with reference to some preferred embodiments thereof, illustrated in the accompanying drawings, given only by way of non-limitative example.
FIG. 1 is a simplified circuit diagram of an elementary output buffer of an integrated circuit according to the prior art.
FIG. 2 is a partial block diagram of a buffer executed according to the teachings of the invention.
FIG. 3 is a more detailed circuit diagram of an implementation of the block diagram of FIG. 2.
FIG. 4 is a circuit diagram of a first variated embodiment of the block B2 of FIG. 3.
FIG. 5 is a circuit diagram of a second variated embodiment of the block B2 of FIG. 3.
FIG. 6 is a circuit diagram of a variated embodiment of the block B3 of FIG. 3.
FIG. 7 is a circuit diagram, partially in block form, of a complete buffer according to the invention.
FIGS. 8, 9 and 10 are circuit diagrams of modifications of the circuits in the preceding FIGURES in order to reduce current consumption.
DETAILED DESCRIPTION
For the sake of simplicity in the description, only a part of an output buffer according to the invention, suitable for performing only switching from "1" to "0", is illustrated in FIG. 2. The execution of a complete buffer also requires a circuit which performs the function of switching from "0" to "1". This type of circuit can be configured in a complementary manner to the one of FIG. 2, or can be provided in a more advantageous manner, as will be described hereinafter with reference to FIG. 7.
In FIG. 2, a block B1 generates a voltage ramp which is applied to a block B2 for converting the voltage ramp into a current ramp. The current from the current ramp is applied to an output stage B3 which directly drives an output node OUT to which a capacitive load C L is connected. The three blocks B1, B2 and B3 are controlled by a single timing signal S1 which is raised to a high level only in a specified time interval assigned to output switching. The signal S1 is low outside said specified interval. The block B1 receives as input a current I REF which has a constant value. The output stage B3 is controlled by a signal DLN which is kept at "0" if the logic level to be provided in output OUT is low and at "1" if the logic level to be provided in output OUT is high.
When the signal S1 becomes high, the voltage ramp in the output from the block B1 begins. Consequently, the current ramp in the output from the block B2 also begins. In the block B3, the current ramp is mirrored in the pull-down transistor with a mirroring factor sufficient to allow the discharge of the load capacitor within the desired time.
FIG. 3 is a more detailed illustration of the circuit of FIG. 2.
Generation of the voltage ramp
In the block B1, two N-channel transistors M12 and M13 are connected in parallel to each other. These transistors are connected in series to an N-channel transistor Mil into which a constant current is injected by a reference current source I REF . The transistor M12 is diode-connected in order to conduct permanently, whereas M11 and M13 are controlled respectively by the direct signal S1 and by the corresponding negated signal S1*. The voltage on the node between the transistors M11 and M12 is applied to the gate electrode of an N-channel transistor M14. The drain electrode on transistor M14 constitutes the output node 01 of the block B1. The drain of transistor M14 is also connected to the power supply through a capacitor C 1 in which the parasitic capacitors of the node 01 are included.
The node 01 is also connected to a resistive divider R1 and R2. This resistive divider is connected between the power supplies in order to generate a constant reference voltage V RI through a P-channel transistor M15. The gate electrode of transistor M15 is driven by the signal S1.
When S1="0", M11 is "off", M13 is "on", and therefore M14 is turned "off". The transistor M15 is "on" and keeps the output node 01 at the voltage value V RI .
When S1 shifts to the "1" level, M11 is switched "on" and M13 and M15 are switched "off". The current I REF is thus mirrored with an adequate mirroring factor in the transistor M14. Additionally, when M14 is switched "on", the capacitor C 1 is charged with a constant current I 14 , The voltage V 01 at the node 01 will thus have a plot which decreases in time in a linear manner, according to the relation ##EQU1##
When the signal S1 returns to "0", the node 01 is returned to its initial conditions, i.e. to the voltage V RI . The voltage V RI is chosen with a criterion which will be explained hereinafter.
Naturally, the generation of the voltage V RI by means of a resistive divider is indicated only by way of example and might be implemented in another manner. For example, V RI may be generated by a chain of two or more MOS transistors, or might be supplied from outside the circuit.
Generation of the Current Ramp
The voltage ramp on the node 01 is converted into a current ramp by operating a MOS transistor in the triode area. The relation between the drain current I d and the gate-source voltage V gs of a transistor which operates in this area is given, as a first approximation, by the equation:
I.sub.d =μC.sub.ox (W.sub.e /L.sub.e)V.sub.ds [(V.sub.gs -V.sub.th)-1/2V.sub.ds ] (2)
In equation (2), μ is the effective mobility of the carriers in the channel, C ox is the capacitance of the gate oxide per unit area, V th , W e and L e are respectively the threshold voltage, the effective width and the effective length of the transistor, and V ds is the voltage applied between the drain and the source of the transistor.
From relation (2) it can be seen that, if the voltage V ds is kept constant, a linear variation in time of the voltage V gs is matched by an also linear variation of the drain current I d . This relationship is used in the conversion performed by the block B2.
The block B2 comprises a pair of P-channel transistors M21 and M25 connected in series. The source of M21 is connected to the power supply line V DDI . The drain of M25 is connected to the power supply line V SSI through a diode-connected N-channel transistor M22. The block also comprises a transistor M23 and a transistor M24, both of which are N-channel type transistors. Transistor M24 is diode-connected and forms a source follower which controls the gate of M25. The node 01 of the block B1 is connected to the gate electrodes of the transistors M21 and M23. The drain of the transistor M22 constitutes the output node 02 of the block B2. The voltage V RI in the block B1 is chosen so that it keeps the transistor M21 of the block B2 at the conduction limit when the signal S1 is "0".
In order to explain the operation of the above described circuit, it is noted that the transistors M22, M23, M24 and M25 operate in the saturation area and the following relation is therefore valid for them:
I.sub.d =1/2μC.sub.ox (W.sub.e /L.sub.e) (V.sub.gs -V.sub.th).sup.2(3)
The symbols in equation (3) have the same meaning as the symbols in relation (2).
The current which flows through M25 is equal, as a first approximation, to the current which flows through M21, but increases as the voltage V 01 decreases. This increase in current flow leads to an increase in the modulus of the gate-source voltage of M25, as expressed by relation (3). However, the voltage applied to the gate of M25 decreases in time during the voltage ramp. Therefore the net effect is to keep the voltage V DD -V 21 across M21 approximately constant.
If V d21 is chosen appropriately, so as to make transistor M21 operate in the triode area and thus in compliance with relation (2) (for example V DD -V d21 ≈500 mV), this operation of transistor M21 produces a current which increases proportionally to V gs , (i.e., a current I ramp whose plot is a linear ramp), and flows in the transistor M21 during the voltage ramp which arrives from the block B1. This current is substantially identical to the current flowing in M22 (by virtue of the adequate speed of the block B2) and is mirrored in the stage B3.
The transistor M21 operates in the saturation area for a short time at the beginning of the switching step because the voltage applied between its gate and source electrodes is initially very close to the threshold voltage. However, in practice this causes no problems because it simply produces a non-linearity in the plot of the current which passes through M21 for low values of current and for a very short period of time.
FIG. 4 illustrates another embodiment of the block B2 which includes the same components as the one described above, but has additional transistors M26, M28 (both of the P-channel type) and M27 (of the N-channel type). The current which flows through M22 is substantially I ramp . This current is mirrored in the branch constituted by the transistors M27 and M28 which operate in the saturation area. The voltage applied to the gate electrode of M26 decreases as the current I ramp increases.
The transistor M26, which is initially off, starts to conduct when I ramp exceeds a preset value, and then operates in the saturation area. It therefore drains part of the current I ramp , reduces the requirements imposed on the set formed by M23, M24 and M25, and contributes to the control of the voltage V d21 . An increase in the drain current simultaneously with a reduction of the gate-voltage also occurs for the transistor M26 and M25.
Another simpler embodiment of the block B2 is illustrated in FIG. 5, which again comprises the transistors M21 and M22. This embodiment functions identically to those already described, but transistor M25, with the associated control circuit, is replaced with the transistor M29, whose gate is controlled by a source of a fixed voltage VREF which has an appropriate value. The transistor M29 must have a very high aspect ratio W e /L e . This very high aspect ratio allows the voltage V gs -V th to remain low when the current I ramp reaches its maximum value (for example, lower than 100 mV). In this manner, the variation of the voltage V d21 during the output switching phase is contained and the current which flows in M21 has a plot which increases in a substantially linear manner in time.
When the buffer is integrated in a circuit manufactured with mixed bipolar-CMOS technology, the MOS transistor M29 can be advantageously replaced with a bipolar transistor. The voltage between the base and the emitter of a bipolar transistor has very small variations even in the presence of a large change in collector current, so the variation of the voltage V d21 is small as the current I ramp varies.
Output stage
With reference again to FIG. 3, a preferred embodiment of the output stage B3 is now described. Said output stage comprises a pull-down output N-channel transistor MD' whose gate GMD is connected to the output node 02 of the block B2 through switch means constituted by a pair of complementary transistors M31 (of the N-channel type) and M32 (of the P-channel type). Transistors M31 and M32 are connected in parallel and are controlled respectively by the direct and negated versions of the timing signal S1. The drain of the transistor MD' is connected to the output node OUT of the circuit for connection to the capacitive load (not illustrated in FIG. 3). When the timing signal S1 is high, the two transistors M31 and M32 are "on", and the transistors M22 of the block B2 and MD' of the block B3 form a current mirror.
In order to maintain control of the transistor MD', the gate of transistor MD is preferably connected respectively to the two power supplies V SSI and V DDI by means of transistors M33 (of the N-channel type) and M34 (of the P-channel type). Transistors M33 and M34 are controlled by the signal DLN as described above, which is low if and only if it is necessary to provide a low level in the output. In static conditions, MD is kept "on" by the transistor M34 when a low output level is desired. MD is kept "off" by the transistor M33 in the opposite case. The size of M34 is such as to not affect significantly the time plot of the voltage on the node GMD during the output switching step, when said output must pass from "1" to "0". In practice it is sufficient for the aspect ratio W e /L e of M24 to be very low, so that it is capable of delivering a current which is much smaller than I ramp .
The transistor M22 of the block B2 is coupled to the output transistor MD in a substantially direct manner (except for the interposed switching means) in FIG. 3. This coupling can be provided in a more sophisticated manner. FIG. 6 illustrates a variated embodiment of the output stage B3 which differs from the one described above with reference to FIG. 3 by virtue of the presence of two current mirroring stages between the node 02 and the output transistor MD .
In this case the node 02 drives (always through the switching means M31 and M32) an N-channel transistor M35 which controls a current mirror formed by P-channel transistors M36 and M37. This current mirror in turn controls a current mirror composed of an N-channel transistor M38 and already described transistor MD . The transistors M33 and M34 are still present and function as described above. This implementation allows for the optimization of the coupling between the transistor M22 and the pull-down output transistor MD . This optimization in turn minimizes the degradation of the speed of the circuit which might occur in the circuit of FIG. 3 due to the high capacitive load of the transistor MD.
COMPLETE BUFFER
A complete buffer can be executed, as mentioned above, by duplicating the pull-down circuit of FIG. 3 with another exactly complementary circuit which can perform the pull-up function. A more advantageous and complete buffer solution, however, is now described with reference to FIG. 7.
This solution requires, in addition to the timing signal S1 (which becomes high in order to cause switching) and signal DLN (which becomes loll in order to provide a low level in output), a new signal DH which is kept at "1" to provide a high level in the output and at "0" in the other cases.
The circuit of FIG. 7 comprises two blocks B1 and B2 according to FIG. 3 or to another variation. The output node 02 of the block B2 is connected to the pull-down transistor MD on one side with a circuital arrangement similar to the one already described for FIG. 3. This embodiment requires for the interposition of further switching means constituted by two transistors M39 and M40, respectively of the N-channel and P-channel type. Transistors M39 and M40 are controlled by the signal DLN in the negated and direct forms. On the other side of the buffer circuit, the connection reaches an N-channel transistor M43 through switching means constituted by a pair of transistors M41 (of the N-channel type) and M42 (of the P-channel type). Transistors M41 and M42 are controlled by the signal DH in its direct form and in its negated form (DH*).
The transistor M43 controls a P-channel current mirror which comprises a transistor M44 and a pull-up transistor MU. The drain electrode of MU is connected to the output OUT which is connected in common with the drain of the pull-down transistor MD . The gate electrode GMU of the transistor MU is controlled by two transistors M45 (of the N-channel type) and M46 (of the P-channel type). Transistors M45 and M45 are controlled by the signal DH.
This part of the circuit also comprises two N-channel transistors M47 and M48 which are connected between the gate of M43 and the power supply V SSI . Transistors M47 and M48 are controlled by S1* and DH*, respectively, in order to eliminate the absorption of current on the part of the branch formed by M43 and M44 when the switching from "0" to "1" in the output is not performed. M47 and M48 eliminate current absorption because S1 must be equal to "0" and/or DH must be equal to "0" in cases where the switching from "0 to "1" in the output is not performed.
The operation of the circuital arrangement of FIG. 7 is evident to the person skilled in the art because of its similarity to the circuits of the preceding figures. When the signals DLN and DH are both "0" , the current ramp generated by the block B2 is mirrored on the pull-down transistor MD. When the signals DLN and DH are both at "1", the current ramp is mirrored on the pull-up transistor MU. It should be noted that if one imposes DH ="0", DLN="1", the current ramp is not transferred to the output at all, because both output transistors MD and MU are "off". This situation places the buffer in a high output impedance state. It can therefore be used as "tristate"buffer.
When it is necessary to drive several output pins having the same switching-speed and capacitive-load requirements in a device, blocks B1 for voltage ramp generation and B2 for current ramp generation, can be shared by a plurality of buffers. Such sharing is possible because the operation of these blocks does not depend on the logic level which must be transferred to the output.
In this case it is obviously necessary to insert a circuit which optimizes the coupling between the block B2 and the individual output stages (blocks B3) associated with the various pins. Direct driving of a plurality of output stages would lead to an excessively high load for the block B2. Optimization of coupling is therefore necessary in order to avoid degrading the resulting electric characteristics of the circuit. This optimization circuit is typically composed of some type of current mirroring stages, such as those already illustrated with reference to FIG. 6.
If it is necessary to reduce current absorption substantially to zero when the integrated circuit in which the buffer is inserted is in standby conditions, the described circuits can be easily modified in order to provide this feature. Reduction in current absorption to substantially zero can be accomplished with the addition of a few auxiliary transistors controlled by an additional standby signal SB. SB is high when the circuit must be put in standby conditions and is low otherwise. FIG. 8 illustrates the insertion of an N-channel transistor MA1 in series to the divider R1 and R2 of FIG. 3. Transistor MA1 is controlled by the negated signal SB* of said standby signal.
FIG. 9 illustrates a similar circuit to FIG. 4, but modified with the addition of N-channel transistors MA2 and MA3. Transistors MA2 and MA3 are respectively controlled by SB* and SB.
Finally, FIG. 10 is substantially the diagram of FIG. 7, but with the addition of transistors MA4, MA6 (of the P-channel type) and MA5, MA7 (of the N-channel type). MA4 and MA5 are always driven by the signal SB in direct form, and MA6 and MA7 are driven by the signal SB*. One skilled in the art will immediately understand that the activation of signal SB switches the transistors MA1-MA7 so as to interrupt all the current paths which would give rise to absorptions during standby conditions (naturally, S1="0" during standby).
Some preferred embodiments of the invention have been described, but the person skilled in the art can devise other equivalent variations and modifications, within the scope of the present invention. For example, a voltage ramp might be designed with a circuit which is complementary to the one illustrated in FIG. 3, thereby obtaining a rising ramp rather than a falling one. This type of voltage ramp could be applied between the gate and source electrodes (with the source electrode connected to V SSI ) of an N-channel transistor which is forced to operate in the triode area with a constant voltage between drain and source. | A fast capacitive-load driving circuit for driving output nodes on an integrated circuit. This circuit reduces noise interference caused by parasitic inductance by lowering the inductance voltage on the power supply lines during the switching process. This invention includes a voltage ramp, a voltage-to-current converter, and an output buffer having at least one pull-down transistor. A further embodiment includes an output buffer possessing a pull-down and a pull-up transistor. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of commonly owned, co-pending provisional application Ser. No. 60/525,481, filed Nov. 25, 2003 and entitled “TOUCHLESS TFT PANEL LAMINATION FIXTURE AND PROCESS”, the entire contents of which are incorporated by reference herein.
FIELD
This patent specification relates to laminating a TFT panel with a glass support plate. More particularly, this patent specification pertains to a method and apparatus for laminating a TFT panel with a glass support plate while refraining from making contact with any portion of the TFT panel's front face other than on peripheral strips that are free of TFTs.
BACKGROUND
Thin film transistor (TFT) panels are frequently fabricated on very thin substrates such as 0.7 mm thick glass panels. The back faces of the TFT panels, i.e. the sides opposite the front faces carrying the TFTs, are subsequently laminated onto glass support plates, commonly using a UV-curable resin, so that subsequent process steps can be performed without damaging or distorting the fragile TFT panels. This approach is well known in the art and is described in U.S. Pat. No. 5,827,757 issued Oct. 27, 1998 to Robinson, et al., which is hereby incorporated by reference. During this process, solid objects should not make contact with the front face of the TFT panel because burrs or dust particles found on solid objects can crush films on the TFT panel.
A previous approach for laminating a TFT panel onto a glass support plate involves holding the TFT panel using a vacuum chuck with a piece of lint-free paper forming a cushion between the chuck and the front face of the TFT panel to avoid having the metal chuck make direct contact with the front face of the TFT panel. Lint-free paper can be used as a cushion because it is both porous and cushioning. Panel laminated according to this approach are offered commercially in this country by the assignee hereof, and further information therein is available at its website, HOLOGIC.COM.
Artifacts can sometimes be found on images captured using TFT panels that have been manufactured using lint-free paper. These artifacts are a result of uneven curing of UV resin used in the TFT panels due to reflection of UV light from the lint-free free paper to the TFT panels. Lint-free paper can also leave small paper particle on the TFT panel that must subsequently be removed using a spin cleaning process. Spin cleaning can add cost and complexity to the TFT panel manufacturing process and can occasionally promote crazing of the TFT panel thereby lowering the manufacturing yield. The vacuum chuck used in this process does not shield the TFT panel from potentially harmful vapors that emanate from the UV-curable resin used to laminate the TFT panel to the glass support plate.
SUMMARY
An object of the disclosed system and method is to solve problems discussed above relating to laminating TFT panels onto glass support plates.
Specifically, an object is to provide a system and method for laminating TFT panels onto glass support plates without making contact with the front face of the TFT panel (the face carrying the TFTs) other than on peripheral strips that are free of TFTs. It is also an object to provide a system and method for laminating TFT arrays onto sturdy glass plates without the use of lint-free paper. It is also an object to reduce artifacts found on images captured using TFT panels relative to images captured from TFT panels manufactured using a previous approach involving lint-free paper. It is also an object to provide a system and method for laminating TFT panels onto glass support plates that may avoid the need for spin cleaning, shield the TFT panel from potentially harmful vapors that emanate from UV-curable resins used to laminate the TFT panel to the glass support plate, and reduce instances of crazing over TFT panels that have been laminated pursuant to the previous approach.
The disclosed system and method laminate TFT panels onto glass support plates without making contact with the front face of the TFT panel other than on peripheral strips that are free of TFTs, while reducing artifacts found on images captured using TFT panels, avoiding the need for spin cleaning, shielding the TFT panel from potentially harmful vapors that emanate from UV-curable resins, and reducing instances of crazing.
The disclosed system comprises a lamination chuck which contacts the TFT panel only on the peripheral strips. The TFT panel is oriented horizontally with the face to be laminated (the back face) facing up and the sensitive front face facing down. The TFT panel is supported by a cushion of gas, preferably dry nitrogen (N 2 ), to prevent the thin TFT panel from sagging under its own weight and to cause the TFT panel to bow up at the start of the lamination process. The gas is prevented from escaping by sealing the perimeter of the lamination chuck with sealing tape. The pressure within the cushion of gas is monitored by a manometer and regulated by a bleed valve, a gas inlet, and a pressure regulator. The peripheral strips are held to the chuck by vacuum channels that are built into the rim of the chuck. While the TFT panel is held firmly in place and bowed up, a UV-curable resin is applied to the TFT panel. The glass support plate is gradually brought into contact with the TFT panel as the pressure within the cushion of gas is reduced. The resin spreads out as the area of contact between the TFT panel and the glass support plate increases. After the TFT panel is flat against the glass support plate, the resin is cured.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 a and 1 b illustrate a laminating chuck in accordance with a preferred embodiment.
FIG. 2 is a plan view of the laminating chuck shown in FIG. 1 detailing the chuck's gas connections and instrumentation.
FIGS. 3 a and 3 b illustrate a sealing cover in accordance with a preferred embodiment.
FIGS. 4 a and 4 b illustrate another view of the sealing cover shown in FIG. 4 .
FIG. 5 illustrates a TFT panel being laminated in accordance with a preferred embodiment.
DESCRIPTION OF PREFERRED EMBODIMENTS
FIGS. 1 a and 1 b illustrate a lamination chuck 10 machined out of a cast aluminum plate to maintain its flatness and dimensional stability. The top surface of the chuck 10 is machined into a 3 mm deep tray or pressure chamber cavity 11 , which is slightly larger in length and width than the active area of a TFT panel, thereby forming a ridge 12 on a second edge 17 of the chuck 10 , third edge 18 of the chuck 10 , and fourth edge 19 of the chuck 10 , leaving the first edge 16 of the chuck 10 without a ridge. No ridge is formed on the first edge 16 of the chuck 10 because the TFT panel 100 (see FIG. 5 ) preferably has active elements extending all the way to the first edge of the panel (the chest wall edge). Sealing tape (not shown) is affixed to the ridge 12 to help maintain desired pressure. The side walls 13 of the chuck 10 are recessed to form a shoulder 14 on all four sides, onto which an adhesive tape drip skirt (not shown) is attached. The drip skirt is used to help catch excess UV-curable resin that escapes from the sides of the chuck 10 during lamination. Vacuum channels 15 are machined into all three sides of the ridge 12 so that the TFT panel can be held firmly in place by three of its edges.
FIG. 2 illustrates the lamination chuck 10 in plan view. An input port 20 leads to a recess 11 that serves as a pressure chamber during the lamination process. N 2 gas enters the input port 20 through a pressure hose 26 and pressure regulator 26 a. Two bleed holes 21 allow excess gas to escape through a needle bleed valve 22 , and two pressure sensing holes 23 allow the pressure inside the pressure chamber 11 to be monitored by a manometer 24 . A second pressure hose 27 connects the manometer 24 to the pressure sensing holes 23 . Suction is applied to the vacuum channels 15 by a vacuum connection hose 25 leading to a vacuum pump (not shown), which may be of the type used for vacuum chucks using lint-free paper.
Preferably, the holes 21 , 23 are positioned as close to the ridge 12 as practical to avoid uneven reflection of UV radiation that is used for curing the UV-curable resin. Preferably, the pressure chamber 11 is sandblasted and the entire chuck 10 is anodized black to minimize reflection of the UV radiation that may cause exposure intensity variations. Preferably, all four sides of the chuck 10 are covered with a Teflon tape 101 ( FIG. 6 ) to avoid scratching the TFT panel, and in particular, bonding pads and pad routing lines on the TFT panel's peripheral strips.
FIGS. 3 a and 3 b illustrate a vacuum sealing cover 40 that is used to prevent the TFT panel 100 from sagging while on the chuck 10 . Two handles 41 are mounted on the top side of the sealing cover 40 . A sealing cover vacuum channel 42 is formed at the underside of the sealing cover 40 . This sealing cover vacuum channel 42 is connected to a vacuum port 43 positioned at the top side of the sealing cover 40 , and the vacuum port 43 is connected to a vacuum pump (not shown). Suction may then be applied through the sealing cover vacuum channel 42 to allow the sealing cover 40 to hold the TFT panel 100 straight and prevent it from sagging down. A bleeder valve port 44 located on the underside of the sealing cover 40 is connected to a bleeder valve knob 45 on the top side of the sealing cover 40 to regulate suction within the sealing cover vacuum channel 42 . Sealing tape 46 is affixed around the vacuum channel 42 and around the edges of the underside of the sealing cover 40 to help maintain the desired suction. FIGS. 4 a and 4 b also illustrate the sealing cover 42 of FIG. 3 .
The chuck 10 , the glass support plate and a UV-curable resin are preheated to 50° C. to reduce the viscosity of the resin. The chuck 10 is preferably heated with a resistance element (chuck heater)(not shown) and a thermocouple (not shown) is used to monitor the temperature of the chuck 10 . The glass support plate and the resin are preferably heated in a convection oven.
As illustrated in FIG. 5 , the TFT panel 100 is positioned on the chuck 10 with the back face (the face to be laminated) up and the front face (the face carrying the TFTs) down. Locating pins (not shown) are used to precisely align the TFT panel 100 on the chuck 10 . The vacuum hoses 25 ( FIG. 2 ) are connected and the vacuum pump is turned on. The drip skirt (not shown) is applied to the second edge 17 , third edge 18 , and fourth edge 19 of the chuck 10 ( FIG. 1 ). The sealing cover 40 is placed on top of the TFT panel 100 with the vacuum channel 42 near the chest wall edge of the TFT panel 100 . Vacuum is applied to the channel 42 to straighten the TFT panel 100 so the drip skirt can be applied to the panel while the panel is straight. The pressure is regulated, preferably to a pressure of 1.2 inch water column (WC). The bleed valve 22 is partly opened to stabilize the pressure and to allow for pressure reduction later. At a pressure of 1.2 inch WC the TFT panel 100 bows up and out to form a dome that is approximately 1 mm high in the center. The resin is poured onto the glass support plate 102 or on the bottom face of the TFT panel 100 , preferably in a dog-bone shape or an oval shape puddle, with the long axis of the puddle parallel to the longer dimension of the glass support plate 102 . The glass support plate 102 is then guided by locating pins (not shown) onto the TFT panel 100 where it is let stand for a length of time, preferably five minutes. In this position, initially only the center of the TFT panel 100 makes contact with the glass support plate 102 causing the excess resin to be squeezed away from the center. Over another length of time, also preferably five minutes, the pressure in the pressure chamber 11 is reduced linearly from 1.2 inch WC to 0.3 inch WC. As the pressure is reduced, the dome flattens out and the excess resin is squeezed out into the drip skirt (not shown). At 0.3 inch WC, the TFT panel 100 is planar. This technique helps to minimize the occurrence of air-bubbles in the resin. Over a settling time, preferably five minutes, potential variations in resin thickness will smooth out. The resin is UV cured with light from a UV source (not shown), preferably for 240 seconds, a shorter length of time than that which is required for the previous method of manufacture. | A method and apparatus for laminating a TFT panel with a glass support plate without the need to touch an active area of the TFT panel. To accomplish this result, a touchless vacuum lamination chuck secures the TFT panel by its outer margins that do not carry TFTs. To facilitate lamination of the TFT panel, a pressure chamber is formed within the laminating chuck to provide support to the center region of the TFT panel as it is brought into contact with the glass support plate. | 8 |
GOVERNMENT INTEREST
The invention described herein may be manufactured, used and licensed by or for the Government of governmental purposes without the payment to me of any royalties thereon.
BACKGROUND OF THE INVENTION
The present invention relates to trigger mechanisms for an automatic weapon and, in particular, to a device having a rapidly operable hammer for firing a weapon.
It is known to have a spring-biased bolt carrier that reciprocates with the assistance of a gas system driven by high pressure gas from the firing of a cartridge. These known systems allow the weapon to rapidly fire successive rounds without the need for operator intervention, provided the trigger is continuouslly depressed.
A disadvantage with the known mechanisms is that their components are too numerous and therefore unreliable and prone to jamming.
Accordingly, there is a need for a triggering mechanism useful for rapidly triggering an automatic weapon and employing relatively few parts.
SUMMARY OF THE INVENTION
In accordance with the illustrative embodiment demonstrating features and advantages of the present invention, there is provided a trigger mechanism for an automatic weapon having a receiver and a bolt carrier reciprocatably mounted in the receiver. The bolt carrier is biased to slide from a recoiled position to a firing position. The mechanism also has a hammer positioned alongside the bolt carrier and pivotally mounted on the receiver for reciprocating between a retracted and a striking position. Also included is a bias means attached to the hammer for urging it into a striking position. The mechanism also has a trigger rotatably mounted on the receiver and a catch means connected between the trigger and the hammer. The catch means can releasably hold the hammer and can retract the hammer in response to rotation of the trigger. The bolt carrier has a stop means and a toggle means. The stop means can engage the hammer and hold the bolt carrier at the recoiled position. The catch means is operable to release the bolt carrier from the stop means by retracting the hammer. The toggle means is positioned for engaging the catch means and causing it to release the hammer as the bolt carrier arrives at the firing position.
By employing such apparatus, a highly improved trigger mechanism is provided. In the preferred embodiment, an automatic weapon uses a spring loaded bolt carrier that uses a gas system to recoil the bolt carrier backwardly to compress the spring. This preferred mechanism employs a pivotally mounted trigger from which a lever articulates. This lever is used as a catch to hold a hammer. The hammer itself is used to hold the bolt carrier.
The preferred mechanism uses the trigger to rotate the lever and thus the hammer, causing it to retreat from a notch on the bolt carrier so that latter is driven forward. When the bolt carrier is driven to a firing position, preferably, a ridge on the carrier strikes the catch lever to release the hammer. Afterward the bolt carrier is returned by the preferred gas system and the hammer and lever are restored to a prefiring position by a ramp on the preferred bolt carrier. It will be noticed that this mechanism can work quickly with relatively few parts.
BRIEF DESCRIPTION OF THE DRAWING
The above brief description as well as other features and advantages of the present invention will be more fully appreciated by reference to the following detailed description of a presently preferred but nonetheless illustrative embodiment in accordance with the present invention when taken in conjunction with the accompanying drawings, wherein:
FIG. 1 is a side view of an automatic weapon incorporating principles of the present inventions;
FIG. 2 is a side view of the bolt carrier in the weapon in FIG. 1;
FIG. 3 is a cross-sectional view through lines 3--3 of FIG. 2;
FIG. 4 is a bottom view (reduced scale) of the carrier of FIG. 2;
FIG. 5 is a front view of the hammer used in the weapon of FIG. 1;
FIG. 6 is a back view of a lever used in the weapon of FIG. 1;
FIG. 7 is a side view, partially in sections of the receiver and associated components of FIG. 1;
FIG. 8A shows a portion of the mechanism of FIG. 7 placed in a safe, seared position;
FIG. 8B shows the condition of the mechanism of FIG. 8A immediately after pulling the trigger;
FIG. 8C shows the mechanism of FIG. 8B just prior to release of the hammer;
FIG. 8D shows the position of the mechanism of FIG. 8C at the instant of firing;
FIG. 8E shows the mechanism of FIG. 8D as the gas system causes the bolt carrier to recoil; and
FIG. 8F shows the mechanism of FIG. 8E with the bolt carrier recoiled backwardly to the maximum extent.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, a weapon 10 is shown having a barrel 12, a receiver 14 and a compression spring 16 for forwardly biasing bolt carrier 18. The receiver 14 has a carrying handle 20 associated with it. Receiver 14 also has a butt handle 22 and a cartridge clip 24. The trigger 26 is rotatably mounted within the body of receiver 14.
Referring to FIG. 2, the bolt carrier 18 is shown separately and in further detail. Generally the bolt carrier has a cylindrical shape and supports on its forward end a breech member 28 for locking a bullet or cartridge (neither shown) into the chamber of the barrel of the weapon.
Coaxially mounted in the central body 18A of bolt carrier 18, is firing pin 30. Firing pin 30 extends forwardly through bolt carrier 18 to engage the cartridge that may lodge against the forward end of the breech 28. In a well known fashion, striking the firing pin 30 can cause a firing of the cartridge.
Referring to FIGS. 2 and 3, bolt carrier 18 is seen to have a pair of flanges or splines 18C and 18D bordering a pair of longitudinal grooves 18E and 18F running the length of the section 18A of bolt carrier 18.
Referring to FIGS. 2, 3 and 4, an axial ramp 18G is shown on the underside of bolt carrier section 18A. Axial ramp 18G diverges from bolt carrier section 18A in a rearward direction. Ramp 18G terminates at its aft end in a rounded, hammer-driving surface 18H. The opposite end of ramp 18G is bordered by a stop means, shown herein as notch 18J. Forward of notch 18J is another ramp 18K similar in construction to ramp 18G.
Aft of bolt section 18A is section 18B. Bolt section 18B is a hollow cylindrical member having on its underside an opening into an aft recess 18L. This opening is illustrated in FIG. 4 as having a narrow rear portion and a wider forward portion. A toggle means is shown herein as a pair of shoulder 18M forming what is referred to herein as the ridge of the aft recess 18L. Connected to the aft end of section 18B is the spring carrier 32 (FIG. 2) described hereinafter in further detail.
Referring to FIGS. 5, 6 and 7, previously mentioned receiver 14 is shown in a longitudinal, cross sectional view. The receiver 14 has an upper frame 44 connected to receiver 14 by bosses such as boss 46. Threaded to a rear aperture of receiver 14 is a spring case 36 closed at its aft end by threaded plug 38. Previously mentioned compression spring 16 is shown mounted around previously mentioned spring carrier 32. Carrier 32 is shown mounted on the open end of bolt section 18B, the insertion length being limited by flange 32B. The aft end of compression spring 16 is lodged against the head of support plate 40, which has a dependent central pin fitting into the illustrated bore of plug 38.
Bolt carrier 18 is illustrated with several splines, such as spline 18N. These and the other splines are the sliding surfaces which contact a cylindrical bore through upper frame 44.
Butt handle 22 is attached to receiver 14 by screw 23. Clip 24 is held to receiver 14 by a magazine latch. Receiver 14 has an outline formed into a alcove spanned by trigger guard 48. A trigger 50 is shown rotatably mounted to receiver 14 at pivot point 52. The outwardly projecting, fingering portion 54 of trigger 50 is approximately at right angles to tang 56. The remaining arm of trigger 50 (shown more clearly hereinafter) projecting upwardly at an angle of approximately 110° with respect to tang 56. An eccentric 61 is rotatably mounted in receiver 14. The eccentric 61 is in the form of a cylindrical rod having a central flattened surface. As illustrated the eccentric faces the outer end of tang 56 and acts as a stop against clockwise motion of the tang.
This upper arm of trigger 50 has articulating from it a lever 58, also referred to as a catch means. From the side, lever 58 generally has an inverted Y shape. Lever 58 also has upper bifurcated arm 58A (bifurcation a pair of members shown more clearly hereinafter). The aft, notched, lower arm 58B acts as a stop against the central hub of trigger 50 while the forward, lower arm 58C acts as a spur.
Rotatably mounted in receiver 14 is hammer 60 having a thickened outer end 60A. Projecting at an acute angle with respect to the thickened end 60A is a tripping arm 60B, sized and positioned to engage the spur 58C.
A bias means is shown herein as coil spring 62, coaxially mounted around the hub 60C of hammer 60. As disclosed hereinafter in further detail, spring 62 urges hammer 60 and lever 58 to rotate in opposite directions, clockwise and counterclockwise, respectively.
Referring to FIG. 5, the forward side of hammer 60 is shown with spring 62 coiled about hub 60C. Spring 62 is a symmetrical spring with the right portion (this view) broken away for clarity. The left coil 62a terminates in an upper arm 62C. Coil 62A and a right coil (not shown) is spanned by inverted, U-shaped wired 62D.
Referring to FIG. 6, the previously illustrated lever 58 is shown having a pair of arms 58A forming a bifurcation in this rear view. Spur 58C is partially visible through a lower notch in aft arm 58B. Members 58A are shown with their upper reaches narrowed to provide shoulders 58D. Shoulders 58D, act as a surface against which the upper end 62E of the spring can act. (End 62E is the end complementing end 62C of FIG. 5). The bore 58F for journaling lever 58 is shown herein in phantom.
Referring to FIG. 8A a partially sectioned view of some of the components from FIG. 7 are given, special attention being given to trigger 50, hammer 60 and bolt carrier 18. A portion of spline 18C is broken away for illustrative purposes and to reveal more clearly the notch 18G. Because it is sectional, lever 58 is seen as composed of two symmetrical, Y-shaped halves spanned by transverse spur 58C and the transverse element composing arm 58B. The tip of the upper portion of lever 58A is shown in phantom since it is on the far side of carrier section 18A, riding in the groove flanked by spline 18D (not visible this view but complementary to spline 18C).
Also clearly shown in this view is that trigger 50 is formed by a lower fingering portion 54 that extends backwardly and underlies the bulk of the tang section 56. Tang section 56 essentially lays in a U-shaped channel cut into the upper surface of triggering portion 54. The tang portion 56 extends forwardly and is crooked upwardly at about 110°, pivot 52 being located at the crook. The upper end 57 of tang portion 56 has a transverse bore for pivotally supporting lever 58. It is noted that the upper reach of portion 57 is surrounded on all sides by the framework of lever 58. Due to the proximity of the transverse members 58B and 58C, the freedom of motion of lever 58 about portion 57 is limited.
In this view, eccentric 61 is shown rotated 90° in comparison to the position shown in FIG. 7. Accordingly, the eccentric bears upon the rearmost end of tang 56, thereby holding it against the wall of receiver 14. Under these circumstances, trigger 50, including its tang section 56, cannot move. Therefore, the striking face of hammer head 60A remains lodged in notch 18G. Although bolt carrier 18 is urged forward by compression spring 16 (FIG. 7) the connection between hammer head 60A and notch 18G prevents any movement.
To facilitate an understanding of the principles associated with the foregoing apparatus its operation will now be brief described. To allow firing of the weapon, eccentric 61 is rotated 90° to the position shown in FIG. 8B. It will be noticed the coil of spring 62, is translationally fixed at the pivot of hammer 60 and urges lever 58 and hammer 60 in opposite directions. Spring 62 urges lever 58 to rotate counterclockwise so that the stop 58B of the lever is driven fully against the rearward face of arm 57. Similarly, hammer 60 is urged to rotate clockwise but the contact between tripping arm 60b and spur 58c prevents further rotation.
When the trigger 50 is pulled, it rotates arm 57 clockwise to drive spur 58C into arm 60B and rotates hammer 60 counterclockwise. The rotation of hammer 60 is sufficient to draw it away from notch 18J so that bolt carrier 18 begins to move into the position illustrated in FIG. 8B. As bolt carrier 18 travels forwardly, it does not immediately disturb lever 58. Accordingly, the spur 58C remains in contact with the arm 60B so that hammer 60 is not free to rotate clockwise.
As bolt carrier 18 travels forwardly, it does, to a limited extent, drive hammer 60 counterclockwise through the inclined surface of axial ramp 18G. Eventually, hammer head 60A rides past the rounded edge 18H marking the transition between the forward and rear sections 18A and 18B, respectively, of bolt carrier 18. However, hammer 60 does not rotate into recess 18L because of the previously described holding action provided by spur 58C. It will be noted that as bolt carrier 18 travels forwardly, the upper sections 58A of the lever 58 are not immediately disturbed since they ride in the grooves flanked by the splines such as spline 18C.
Eventually, bolt carrier 18 travels sufficiently forward that the upper portions 58A of lever 58 and hammer 60 are protruding into recess 18L. It will be noted that for the positions illustrated in FIG. 8C, the corner of hammer 60 protruding into recess 18L does not touch the sides of recess 18L since hammer head 60A is sized to fit within the narrower opening on the underside of recess 18L. The shoulder 18M of recess 18L, however, engages the tip of lever arm 58A. Consequently, continued forward motion of bolt carrier 18 from the position illustrated in FIG. 8C causes clockwise rotation of lever 58, in opposition spring 62. As a result, spur 58C begins to move away from its seared position on arm 60B of hammer 60.
Eventually hammer 60 is released and is driven clockwise under the driving force of spring 62 against firing pin 30, as illustrated in FIG. 8D. Lever 58 has also rotated clockwise somewhat due to the momentum imparted to it by its collision with the shoulder 18M of bolt carrier 18. The striking of firing pin 30 causes a shock that fires the cartridge adjacent to the forward end of the bolt carrier 18. Such firing produces high pressure gas from the combustion of the explosives of the cartridge. In a well known fashion, this explosive gas may be used to drive bolt carrier 18 backwards as shown in FIG. 8E. This backward motion causes the shoulder 18H of bolt carrier 18 to engage the forward face of hammer head 60A and drive it counterclockwise as shown.
Since hammer head 60A is now riding on the elevated portion of axial ramp 18G, it has freed itself from the connection to spur 58C of lever 58. Therefore, lever 58 is free to rotate counterclockwise under the driving action of spring 62 until stopped by element 58b touching trigger 50. Trigger 50 has cylindrical bosses protruding coaxially with pivot pin 52, through which pin 52 passes. Element 58b contacts these bosses. As hammerhead 60A rides down axial ramp 18G, its spur 58G returns clockwise against hammer arm 60B returns clockwise against spur 58C so that hammer 60 is now seared.
The inertia of bolt carrier 18 due to the force from the gas driving system (not shown) drives carrier 18 fully backwards to the position illustrated in FIG. 8F, the rearward travel being limited by impact with a rubber buffer through support plate 40. If the trigger 50 is kept in the position shown then hammer head 60A will remain sufficiently withdrawn to escape notch 18J. Consequently, hammer head 60A will pass notch 18J and return to the position shown in FIG. 8B to repeat another cycle. If the trigger 50 is released before hammer head 60A reaches notch 18J, a different result occurs. In particular, trigger arm 57 will rotate counterclockwise to so move spur 58C that hammer head 60A will descend onto ramp 18K. Consequently, the forward motion of carrier 18 will result in hammer head 60A sliding down ramp 18K into notch 18J to prevent further motion of bolt carrier 18. If the eccentric 61 is now engaged, the apparatus returns to the condition initially illustrated in FIG. 8A.
It is to be appreciated that various modifications may be implemented with respect to the above described preferred embodiment. While a single spring is shown for driving the lever, hammer and trigger, in some embodiments two or more springs may be used to separately drive these components. While a torsional spring is shown, in some embodiments a compression spring may be linked to various extensions of the components to drive them in the desired direction. Also while the hammer is shown engaging a notch, in some embodiments it may engage a shoulder of a simple protusion. Furthermore, the trigger tang illustrated for safety purposes may be eliminated where an alternate safety is employed. While a bifurcated lever is shown as a catch, in some embodiments bifurcation may be unnecessary and a single, upwardly extended lever arm may be employed instead. Moreover, various shapes, sizes and dimensions of the various illustrated components can be altered depending upon the desired strength, capacity, speed of operation, reliability, etc.
Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described. | A trigger mechanism for an automatic weapon which has a bolt carrier recicatably mounted in a receiver and biased to slide from a recoiled position to a firing position. The mechanism has a hammer positioned alongside the bolt carrier and pivotally mounted on the receiver for reciprocating between a retracted and a striking position. Also included are a bias spring, a trigger and a catch. The trigger is rotatably mounted on the receiver while the bias spring is attached to the hammer for urging it into a striking position. The catch is connected between the trigger and the hammer for releasably holding the hammer. The catch can retract the hammer in response to rotation of the trigger. The bolt carrier has a stop for engaging the hammer and holding the bolt carrier at its recoiled position. The catch is operable to release the bolt carrier from the stop by retracting the hammer. The bolt carrier also has a shoulder positioned for engaging the catch and causing it to release the hammer as the bolt carrier arrives at the firing position. | 5 |
This is a continuation of application Ser. No. 729,676, filed May 2, 1985, and now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus for marking a contaminated area or the like with a signal element set on a support tube and provided with warning symbols.
Such apparatuses are perhaps pennants for delimiting sections of terrain and are stuck there with a shaft end in the ground. A pennant is then located at the upper end of the shaft, to indicate the marking point more clearly. Such pennants are also known with warning expressions of various kinds.
Knowing these circumstances, the inventor set himself the task of creating a marking apparatus which enables contaminated regions to be marked from the air without having to be entered on foot. This apparatus is both to be manipulated without problems and also to be easily stored, and to be suitable for different circumstances. In particular, it is the object of the invention to improve the manipulability and also the availability of the pennant.
SUMMARY OF THE INVENTION
The foregoing object is solved by making the pennant a foil pennant, and connected to the support pipe by a permanent magnet strip. It is also within the scope of the invention for the foil pennant to have a polyester foil which can be rolled up, or a retroreflecting foil of a thickness of 0.1-0.45 mm, or for it to consist of a phosphorescent or fluorescent luminous foil of low thickness.
It has been found to be favorable here to print the luminous foil or even the polyester foil with retroreflecting symbols, for example, with the warning expressions, "ATOM", "BIO", "GAS", "MINES". The warning notices are thus of particular optical intensity and visible for a considerable distance.
Since the foil pennant according to the invention is provided with at least one magnetic strip, it remains easily manipulable and can also be released without difficulty from the support pipe. This needs a steel core as a counter-magnet and is preferably produced as an aluminum tube with a thin-walled steel tube pressed into it.
According to a further feature of the invention, the triangular foil pennant is provided, both on its hypotenuse and also at the vertex opposite this, with a magnetic inlay, which is of particular importance when the foil pennant is to be fixed by this corner on the support tube to reach its stretched position.
The attachment of the magnetic strip to the foil pennant is effected by adhesion, welding or pressing. For example, a resilient yoke can be utilized to hold this magnetic strip.
The foil pennant is easily rolled up, and stored and transported in large numbers in the usual roll-up containers, to be joinable onto the support tube immediately before being ejected from the aircraft or the like.
A good position of the foil pennant is in particular achieved when the support tube ends in a foot part, occupying the center of gravity of the whole signal element; the foot part is either a heavy metal point, which then penetrates into the ground in a known manner, or a synclastically curved surface, preferably a spherical half shell. When the apparatus is ejected from an aircraft, the support tube inserted into the spherical half shell automatically straightens, under the influence of gravity, into the signal or use position and thus does not need correction by human hand.
The spherical half shell preferably consists of impact-resistant material, principally of nylon 66, which is filled with cast lead or the like weighting metal, which has plastic cast over it.
Both this heavy metal tip and also the spherical half shell are coupled to the support tube by a plug connection, and can thus be released from the latter without difficulty.
The releasable connection between the foot part and the support tube mainly serves for adaptation to the requirements at any given time, but also for storage, which is already very advantageous per se with the foil pennant according to the invention.
It has been found to be advantageous if the pennant, rolled up around the shaft in the inoperative position, unrolls under the action of at least one leaf spring; this leaf spring can be wound with the pennant around the holding tube in the inoperative position, and can be fixed there, for example, by the said magnetic corner of the foil pennant.
The said leaf spring can also be fitted radially on the support tube, so that the pennant is laterally stretched; in this case it is particularly simple to fix the foil pennant to the leaf spring by means of the magnetic strip.
Further advantages, features and characteristics of the invention will be gathered from the following description of examples of preferred embodiments and also with reference to the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a side view of a marking apparatus in partially sectioned inoperative position;
FIG. 2 shows the marking apparatus of FIG. 1 in the use position;
FIG. 3 shows a part of another marking apparatus in inoperative position, in front view;
FIG. 4 shows a sectioned detail of another embodiment;
FIG. 5 shows an enlarged cross section of the detail of FIG. 2 according to its area V which is enlarged; and
FIG. 6 shows parts of FIG. 3 in side view.
DETAILED DESCRIPTION
A marking apparatus 1, principally for marking terrain, plant, and the like which are contaminated radioactively, by biological weapons, or with poison gas, has a triangular pennant 4 at one end of the shaft embodied as the support tube 3; in FIG. 1, the pennant 4 is wound, in its inoperative position, about the support tube 3 and is surrounded by a holding ring 5. A magnetic strip 6 is pressed, welded or adhered into the pennant 4 on its hypotenuse and connects the pennant 4 to the counter-magnetic support tube 3.
Due to the a spring 7 incorporated in the pennant 4 and rolled up in the inoperative position, the pennant 4 unrolls according to FIG. 2 when, after the marking apparatus 1 has struck an obstacle 8, the holding ring 5 has fallen downward from the rolled-up pennant.
Instead of the slidable holding ring 5, one of brittle rupturable material can be used; it breaks, and thus releases the pennant 4, when the marking apparatus 1 hits.
The support tube 3 of the marking apparatus 1 is seated in a concave foot 9, which is made from a spherical half shell 10 with a tube stump 11 internally molded on as a coupling part for the support tube 3. The remaining concave space is filled with weighting material 13, principally cast lead. This concave foot 9 enables the marking apparatus 1 to be thrown out of an aircraft, for example, and in fact even where the ground would not permit penetration of a point 15 (FIG. 4), which can be used as an alternative to the concave foot 9 and can be coupled to the support tube 3 in the manner described. Due to the weighting property of the concave foot 9, the marking apparatus always seats on this, after which the support tube 3 swings into the vertical position.
The point 15 is a hollow spike of forged steel, in which a friction bushing (not shown) of plastic is mounted in the manner of a releasable hose seal, to receive the support tube 3 of light alloy.
The spherical half shell 10 consists of impact-resistant plastic (nylon 66) and is cast with the weighting material 13 (in special cases activated with Pm-147 or C-14) and also with plastic (UP/polyester).
The pennant 4 can also be fixed to a crossbar 16 in the manner described; the latter is jointed by two hinge flaps 17 and a hinge bolt 18 to the shaft end 3 e flanked by those hinge flaps 17, but can also, not shown, be pivotable in the direction of the arrow t.
A triangular permanent magnet inlay 19 is provided at the lower end of the pennant and holds the pennant 4, secure against fluttering, on the support tube 3.
The foil material of the symbol foil 30, of thickness Z between 0.1 and 0.45 mm, for the pennant 4, or as a coating for the marker shield 16, is a polyester foil, a phosphorescent luminous foil, or a fluorescent luminous foil with retroreflecting, e.g., containing so-called ballotini glass beads, symbols 31 or symbols (ATOM; GAS; MINES; BIO) in normal printing. A retroreflecting reflex foil with normal symbol printing can also be utilized.
For the sake of clarity, it is not shown in the drawing that the support tube 3 consists of an aluminum profile with an inserted iron tube as core.
FIG. 6 shows the upper part of a support tube 3, with rigid marking shield 41, pivotable about the hinge bolt 18. A coil spring 46 is stretched, as a force accumulator in the interior of the tube, between the hinge bolt 18 and a retaining pin 47 crossing the support tube 3.
It is to be understood that the invention is not limited to the illustrations described and shown herein, which are deemed to be merely illustrative of the best modes of carrying out the invention, and which are susceptible of modification of form, size, arrangement of parts and details of operation. The invention rather is intended to encompass all such modifications which are within its spirit and scope as defined by the claims. | An apparatus for marking a contaminated area comprising a support tube having on one end thereof a device for supporting the tube upright and at a distance spaced from the device with a signal element. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an image forming apparatus such as a copying machine, and more particularly, to an image processing controller of the image forming apparatus.
2. Description of the Prior Art
As shown in FIG. 2, a digital color copying machine has an image processing controller 5 as well as in a copying machine 1, a scanner unit 2 which reads out an original image to convert it into an electric signal and outputs the signal, an operation unit 3 and a printer unit 4. The operation unit 3 includes a central processing unit (CPU) which generates commands to control processings based on operation of an operation key, the scanner unit 2 and the printer unit 4.
The image processing controller 5 also has a CPU which performs data communication with the operation unit 3 and sets data in accordance with circumstances. For example, the magnification of a zoom circuit and the coefficient of a filter are set by the controller 5. When a copy key is depressed at the operation unit 3, a handshaking as shown in Table 1 is performed between the operation unit 3 and the image processing controller 5. Prior to the depression of the copy key, various mode data and original/sheet data are transmitted from the operation unit 3 of the copying machine 1 to the image processing controller 5.
When the copy key is depressed, the operation unit 3 requests the image processing controller 5 to set a scanner mode. Receiving this request, the image processing controller 5 sets the scanner mode. When the setting is completed, the image processing controller 5 transmits a reply in the form of a recognition. Then, the operation unit 3 prepares for shading and transmits a shading request to the image processing controller 5. The image processing controller 5 performs shading and transmits a shading recognition. The shading is performed for both black image data and white image data.
Then, the operation unit 3 transmits a pre-scanning request. Receiving this, the image processing controller 5 sets a pre-scanning data and returns a pre-scanning recognition. The operation unit 3 performs a pre-scanning operation and transmits an image processing request. Receiving this request, the image processing controller 5 performs processings such as an original sensing, an original area processing, a color sensing and an automatic exposure. The original sensing is the sensing of the size of an original. The color sensing is the sensing of a specified color in color conversion. When these processings are completed, the results are returned in the form of an image processing recognition.
Receiving the results, the operation unit 3 performs various calculation processings. For example, when an original size data is transmitted, if the size of the original is A4 although the A3 size cassette is selected, a zoom magnification calculation is performed by using an automatic magnification selecting function. The calculation results are transmitted to the image processing controller 5. In the full-color copying where the development is performed in the order of magenta, cyan, yellow and black, the operation unit 3 transmits a command that the color developed at first be magenta to the image processing controller 5 and requests copying. When the calculation of the image processing data and the setting of the development of magenta are completed, the image processing controller 5 returns a recognition representing that copying is possible.
The operation unit 3 performs a copying operation of magenta. Then, the operation unit 3 transmits a command that the development color be cyan and requests copying. Thereafter, a handshaking and a copying operation similar to those of magenta are performed with respect to magenta, yellow and black to complete the color copying operation.
The image processing controller 5 sets the data through the handshaking with the operation unit 3. In other words, the conventional image processing controller 5 cannot set the data if the communication data are not transmitted from the operation unit 3. The image processing controller 5 is formed on one circuit board to be incorporated in the copying machine, and the function of the image processing controller 5 cannot be checked unless the controller 5 is connected to the copying machine to perform data transfer. This is frequently inconvenient when the manufacture of the image processing controller 5 is consigned to a subcontractor or a collaborator. For example, even if a copying machine is lent to a consignee, the maintenance of the copying machine is sometimes necessary. If the consignee is far away, a quick maintenance is difficult.
SUMMARY OF THE INVENTION
An object of the present invention is to provide an image processing controller capable of checking its own function by performing a pseudo copying operation.
To achieve the above-mentioned object, according to the resent invention, in an image processing controller which sets various data necessary for an image forming operation by performing a data communication with an operation unit of an image forming apparatus, pseudo operation means having a function equivalent to the function of the operation unit with respect to data transfer and means for performing a handshaking with the pseudo operation means.
With such a feature, the image processing controller is capable of obtaining pseudo copying information without being connected to the copying machine, so that the processing and setting of data can be performed based on the information. Thus, the function of the image processing controller is checked without the copying machine.
BRIEF DESCRIPTION OF THE DRAWINGS
This and other objects and features of this invention will become clear from the following description, taken in conjunction with the preferred embodiments with reference to the accompanied drawings in which:
FIG. 1 is a block diagram of an image processing controller embodying the present invention;
FIG. 2 shows the arrangement of a signal transfer between the image processing controller and the copying machine; and
FIG. 3 is a view of assistance in explaining a pseudo communication operation in the image processing controller of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinafter, an embodiment shown in the drawings will be described. Referring to FIG. 1, there is shown the arrangement of a data communication arrangement for setting data in checking the function of an image processing controller 5. The image processing controller 5 is connected to a pseudo signal generator 6. The pseudo signal generator 6 isformed as a pattern generator which outputs an image data S1, a vertical synchronizing signal S2 which synchronizes with the front end of an original and a horizontal synchronizing signal S3 which supplies synchronism in the main scanning direction. Further, the pseudo signal generator 6 also outputs a second vertical synchronizing signal S6 which synchronizes with the front end of a copy sheet. The image processing controller 5 has a CPU 7, and has an image processing control task 8 and apseudo operation unit task 9 as the programs for the CPU 7. In addition thereto, a task for simultaneously operating (transmitting) those tasks isprovided. This task is not shown.
A data S4 is transmitted from the pseudo operation unit task 9 to the imageprocessing control task 8, and a data S5 is transmitted from the image processing control task 8 to the pseudo operation unit task 9. A video data S7 is outputted from the image processing controller 5. The video data is a pulse width modulation (PWM) signal and serves as a drive signalfor a laser apparatus to form a latent image on a photoreceptor drum.
When the image processing controller 5 operates to check its own function, the above-mentioned transmission of the signals S4 and S5 is permitted. Atthis time, the pseudo operation unit task 9 plays a part similar to that ofthe operation unit 3 of FIG. 2. Therefore, a handshaking as shown in Table 2 is performed between the pseudo operation unit task 9 and the image processing control task 8. This handshaking is substantially the same as the handshaking of Table 1 performed with the actual operation unit 3 of the copying machine. However, the setting of the scanner data does not exist. This is because it is unnecessary to set the scanner data since thescanner is not used in checking the function of the image processing controller 5.
Referring to FIG. 3, there is shown a conceptional arrangement centered on the image processing control task 8 and the pseudo operation unit task 9 in the image processing controller 5. Reference numeral 10 represents a read only memory (ROM) incorporating a data table in which pseudo operation unit data D1, D2, . . . are stored. Reference numeral 11 represents a random access memory (RAM) including a reception area 12 for receiving the pseudo operation unit data and a transmission area 13 for receiving the results of the processings performed by the image processingcontroller 5.
First, the pseudo operation unit task 9 transfers (sets) the data D1 of theROM 10 in the reception area 12 of the RAM 11. The image processing controltask 8 sees this. Since the data D1 has been received, the task 8 performs a processing to the image processing controller 5. After the processing iscompleted, the task 8 sets the result of the processing in the transmissionarea 13 (i.e. returns the result as a recognition). The pseudo operation unit task 9 sees the contents of the result written in the transmission area 13. After confirming the result, the task 9 transmits the next step data D2 from the ROM 10 to the reception area 12. By successively performing this operation, a handshaking is seemingly performed between the pseudo operation unit task 9 and the image processing control task 8.
The image processing control task 8 and the pseudo operation unit task 9 are programs on the CPU. These programs must run simultaneously. Therefore, a base program to simultaneously run these programs is providedin the image processing controller 5.
When the image processing controller 5 of this embodiment is incorporated in an electrographic copying machine to perform an actual copying operation, the image processing controller 5 is connected as shown in FIG.2 to perform data communication with the actual operation unit 3. Therefore, the pseudo operation unit task 9 is not operated.
As described above, according to the present invention, the image processing controller is capable of checking its own function in the function check performed at the time of the manufacture of the image processing controller, so that only the pattern generator is necessarily connected to the image processing controller and that no actual image forming apparatus in which the image processing controller is to be incorporated is necessary. Thus, the present invention is convenient and the manufacture and test processes are smoothly performed.
Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understoodthat within the scope of the appended claims, the invention may be practiced other than as specifically described.
TABLE 1______________________________________ ##STR1## ##STR2##Copy key ON ##STR3## ##STR4## ##STR5## ##STR6## ##STR7## ##STR8## ##STR9## ##STR10## ##STR11## ##STR12## ##STR13## ##STR14## ##STR15## ##STR16## ##STR17## ##STR18## ##STR19## ##STR20## ##STR21##______________________________________
TABLE 2______________________________________ ##STR22## ##STR23##Copy key ON ##STR24## ##STR25## ##STR26## ##STR27## ##STR28## ##STR29## ##STR30## ##STR31## ##STR32## ##STR33## ##STR34## ##STR35## ##STR36##______________________________________ | An image processing controller sets various data necessary for an image forming operation by performing a data communication with an operation unit of an electrographic copying machine. The image processing controller has a pseudo operation task having a function equivalent to the function of the operation unit with respect to data transfer and an image processing control task for performing a handshaking with the pseudo operation task. The pseudo operation task and the image processing control task are constituted by operation programs of a CPU provided in the image processing controller. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The subject invention relates to a switched-mode power supply which stabilizes an output voltage by sampling feedback information during a certain time interval.
2. Description of the Related Art
U.S. patent application Ser. No. 08/927,831, filed Sep. 11, 1997, now U.S. Pat. No. 5,831,839 (Attorney Docket No. PHN 16,282), discloses a switched-mode power supply which comprises a transformer with a primary winding and a secondary winding. The primary winding is connected to an input supply voltage via a switching device in order to obtain a periodically interrupted primary current through the primary winding by opening and closing the switching device under the control of a drive signal. The secondary winding is connected, via a rectifying diode, to a parallel arrangement of a smoothing capacitor and a load to supply a DC output voltage to the load. The transformer also includes an auxiliary winding which, due to coupling with the secondary winding, supplies an auxiliary voltage which is closely related to the DC output voltage of the secondary winding during a period of time when the rectifying diode conducts. A controller circuit is coupled to the auxiliary winding and receives feedback information for generating a drive signal for the switching device.
The controller circuit includes a sample-and-hold circuit for periodically sampling a current in the auxiliary winding, and for storing the sampled signal on a storage element. A drive circuit, coupled to the storage element, determines the drive signal for the switching device based on the sampled signal stored on the storage element. It is the object of the storage element to store an averaged sampled signal which is indicative of the DC output voltage. Due to the switching of the switching device, there are times when the auxiliary voltage drops below a regulation level. To prevent an erroneous level in the stored sampled signal, the sampling is only conducted when the current in the auxiliary winding is above a predetermined level which is equivalent to approximately 83% of the regulation level.
While this sampling control works adequately, Applicants have found that this type of control is subject to errors. In particular, the auxiliary voltage only remains at the intended level when there is current flowing in the secondary winding of the transformer. When this current drops to zero, the auxiliary voltage begins to ring. Any information sampled during the time that the auxiliary voltage is ringing is error information.
SUMMARY OF THE INVENTION
It is an object of the subject invention to provide a switched-mode power supply having a sampling circuit which avoids sampling when the auxiliary voltage is ringing.
This object is achieved in a switched-mode power supply comprising a transformer having a primary winding, a secondary winding, and an auxiliary winding, the secondary winding being coupled to a smoothing capacitor via a rectifier element to supply a DC output voltage; a switching device having a main current path arranged in series with the primary winding of the transformer; and a controller circuit having an output for supplying a drive signal to a control input of the switching device for periodically switching the switching device on and off, and an input coupled to the auxiliary winding of the transformer for receiving information indicative of the DC output voltage, said controller circuit controlling the on and/or off periods of the switching device in order to obtain a desired value of the information from the auxiliary winding in a steady state situation, wherein said controller circuit comprises a sample-and-hold circuit for periodically sampling said information at the input of said controller circuit; storage means coupled to an output of said sample-and-hold circuit for storing a sampling signal; and means coupled to said storage means for generating the drive signal applied to the output of said controller circuit; and wherein said sample-and-hold circuit comprises means for controlling said sample-and-hold circuit to sample said information when said switching device is off and only when current is flowing in said secondary winding.
BRIEF DESCRIPTION OF THE DRAWINGS
With the above and additional objects and advantages in mind as will hereinafter appear, the invention will be described with reference to the accompanying drawings, in which:
FIG. 1 is a schematic block diagram of a switched-mode power supply;
FIG. 2 is a block diagram of a controller used in the switched-mode power supply of FIG. 1;
FIG. 3 is a schematic diagram of a prior art sample-and-hold circuit for use in the controller of FIG. 2;
FIGS. 4A-4G show waveforms in the switched-mode power supply; and
FIG. 5 is a schematic diagram of a sample-and-hold circuit in accordance with the subject invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a schematic diagram of a known switched-mode power supply. In particular, a diode rectifier bridge REC is connected to a line voltage source. An output from the rectifier bridge REC is connected to ground through a capacitor C11 and to one end of a primary winding L11 of a transformer TR. The other end of primary winding L11 is connected to one terminal of a switching device Tr11, the other terminal of which being connected to ground through a sense resistor R SENSE . A first secondary winding L12 of the transformer TR has a first end and a second end connected to each other through a series arrangement of a diode D11 and a main output capacitor C12, the second end of the first secondary winding L12 also being connected to ground. A load (not shown) may be connected across the main output capacitor C12.
The transformer TR also includes a second secondary winding L13 having a first end and a second end connected to each other through a series arrangement of a diode D12 and a control output capacitor C13, the second end of the second secondary winding L13 also being connected to ground. A microprocessor (not shown), for controlling, for example, a television receiver in which the switched-mode power supply circuit is installed, is connected across the control output capacitor C13 to receive operating power.
The first end of the first primary winding L12 is also connected via a diode D13 and a controllable switch Sw1 to one end of the control output capacitor C13, while the control output capacitor C13 is shunted by a series arrangement of a light emitting diode D14 of an opto-coupler, a Zener diode Z1 and a controllable switch Sw2. The controllable switches Sw1 and Sw2 are controlled by a signal from the microprocessor to initiate the stand-by mode of the switched-mode power supply circuit.
The transformer TR further includes an auxiliary primary winding L14 which has one end connected to a diode D15, and then to ground through a V AUX capacitor C14, to a V AUX input of a controller IC, and to one terminal of a light sensor Tr12 of the opto-coupler, the other terminal of the light sensor Tr12 being connected to ground via resistor R11, and to a stand-by mode detecting input (OOB)of the controller IC. In addition, a series arrangement of two resistors, R12 and R13, and a Zener diode Z2 connect the output of the rectifier bridge REC to ground. The junction between resistor R13 and Zener diode Z2 is connected to the OOB input via a power switch Sw3. The other end of the auxiliary primary winding L14 is connected to ground. The controller IC also has a V IN input connected to the output of the rectifier bridge REC, a D MAG input connected through a resistor R14 to the one end of the auxiliary primary winding L14, a driver output connected to the control input of switching device Tr11, an I SENSE input connected to the resistor R SENSE , and a V CTRL terminal connected to ground by a discharge capacitor C15.
FIG. 2 shows a block diagram of a known controller IC. The controller IC includes a start-up current source 30 coupled to the V IN input and a Vcc management circuit 32 connected to the V AUX and I REF inputs. The OOB input is connected to a first comparator 34 for comparing the voltage thereon to +2.4 V, and generates an "OFF/ON" signal. This OFF/ON signal is applied to an input of the Vcc management circuit 32. The OOB input is also connected to a second comparator 36 for comparing the voltage thereon to +5.6 V, for generating a "Burst Mode Stand-by" signal S6. This signal S6 is applied to the start-up current source 30 and to a first input of an OR-gate 38. An output (S5) from the Vcc management circuit 32 is also applied to the start-up current source 30 and to an inverting second input of OR-gate 38. An output from OR-gate 38 is applied to the reset input of an RS flip-flop 40, the set input being connected to an output of an oscillator 42 which is connected to the output of a frequency control circuit 44 having an input connected to the I SENSE input. The Q output from the RS flip-flop 40 is connected to one input of an AND-gate 46 which has an output connected to a driver 48 for driving the switching device Tr11. The other input of the AND-gate 46 is connected to the output of an over-current protection circuit 50 which monitors the current through the VDMOS via the I SENSE input. The D MAG input is connected to a demagnetization management circuit 52 and a negative clamp 54 for protection against saturation of the inductor in the power supply. The presence of demagnetization protection guarantees discontinuous conduction mode operation which simplifies the design of feedback control and gives faster transient response for the system. An output from the demagnetization management circuit 52 is connected to the oscillator 42. In addition, the D MAG input is connected to an over-voltage protection circuit 56 having an output connected to a third input of the OR-gate 38, which also has a fourth input connected to the output of an over-temperature protection circuit 58.
The D MAG input is also connected to a sample-and-hold circuit 60 the output of which is connected to the V CTRL terminal of the controller IC and to one input of an error amplifier 62 which receives a 2.5 V. reference voltage at another input. The output from the error amplifier 62 is connected to one input of a pulse width modulation (PWM) comparator 64 which receives an output from the oscillator 42 at a second input. The output from the PWM comparator 64 is connected to a fifth input of the OR-gate 38. The error amplifier 62 and the PWM comparator 64 form a PWM circuit which compares the voltage on the discharge capacitor C15, which is supposed to be a sampled representation of the output voltage, to the oscillator waveform to determine the duty cycle of the switching device.
FIG. 3 shows a schematic diagram of a sample-and-hold circuit in accordance with U.S. patent application Ser. No. 08/927,831, now U.S. Pat. No. 5,831,839 filed Sep. 11, 1997 (PHN 16,282). An input of the sample-and-hold circuit, connected to the D MAG input, is connected to a first current mirror 70 which is connected to ground. The current I AUX at the D MAG input is then mirrored to the output of the first current mirror 70 and is, in turn, applied to an input 72 of a second current mirror 74. A first output 76 of the second current mirror 74 is connected to ground via a first current source 78 which supplies a current 0.83*I REF . The first output 76 is further connected to the input of a buffer 80 having an output connected to a first input of an AND-gate 82. A second output 84 of the second current mirror 74 is connected to ground via a second current source 86 which supplies a current I REF , The second output 84 is also connected to an input terminal of a controllable switch Sw4 having an output terminal forming the output of the sample-and-hold circuit, and which is connected to the V CTRL terminal of the controller IC. An output from the AND-gate 82 is connected to a control input of the controllable switch Sw4. A second input of the AND-gate 82 receives a demagnetizing signal from a demagnitizing sensing circuit (not shown), the demagnetizing signal being high during demagnetization of the transformer and low during the remainder of the switching cycle.
FIGS. 4A-4G show various waveforms in the switched-mode power supply. In particular, FIG. 4A shows gate pulses generated by the controller IC which are applied to the gate of the switching device Tr11 causing the switching device Tr11 to periodically close. FIG. 4B shows a waveform of the current in the primary winding L11 which steadily increases until the switching device Tr11 opens, at which time the current rapidly drops to zero. FIG. 4C shows the current in the secondary winding L12 which, at t1, rapidly increases to a predetermined value and then steadily decreases to zero at t2. FIG. 4D shows the auxiliary voltage V AUX generated by the auxiliary winding L14 which is representative of the DC output voltage from the secondary winding L12. When the switching device Tr11 opens, the auxiliary voltage V AUX rapidly rises to its nominal regulation value V REF , which is equivalent to I REF . When the auxiliary voltage V AUX rises above 83% of the nominal regulation value, the current I AUX at the first output 76 of the second current mirror exceeds that of the first current source 78 and causes the buffer 80 to apply a high level signal to the AND-gate 82 which, in turn, closes the controllable switch Sw4 causing the sample-and-hold circuit to begin sampling the current I AUX supplied by the auxiliary winding L14 and storing the sampled signal on discharge capacitor C15. This sampling continues until the auxiliary voltage V AUX drops below the 83% level. However, as shown in FIG. 4D, the period between t2 and t3 includes a time when the auxiliary voltage V AUX begins to ring which leads to an incorrect sampled signal being stored on discharge capacitor C15.
The sample-and-hold circuit of the subject invention seeks to avoid these erroneous samplings. As shown in FIG. 5, an input of the sample-and-hold circuit, connected to the D MAG input of the controller IC, is connected to a current mirror circuit 90 formed by an input transistor T1 and two output transistors T2 and T3. The applied current I AUX from transistor T2 is compared, in current comparator 95, to the current 0.83*I REF which is supplied by a current source 94 and mirrored by current mirror 92. When the I AUX current exceeds 0.83*I REF , current comparator 95 applies a signal to a logic circuit 96, having an input connected to the output of transistor T2. The output from the transistor T3 of the current mirror circuit 90 is applied to an input of a second current mirror 98, having an output connected to a current source for generating the current I REF . The output from the second current mirror 98 is also connected to an input of the controllable switch Sw4, having a control input connected to an output of the logic circuit 96, and an output terminal forming the output of the sample-and-hold circuit which is, in turn, connected to the V CTRL terminal of the controller IC having the discharge capacitor C15 connected thereto.
In order to further control the switching of the controllable switch Sw4, the sample-and-hold circuit includes the series arrangement of a current source 102 for generating a current I1, a first controllable switch Sw5, a second controllable switch Sw6 and a current source 104 for generating a current I2. the junction between the first and second controllable switches Sw5 and Sw6 is connected to ground through a capacitor C16 and to a first input of a comparator 106, having a second input connected to ground. The output from the comparator 106 is connected to an input of the logic circuit 96. The first and second controllable switches Sw5 and Sw6 have control inputs connected, respectively, to outputs from the logic circuit 96. Similarly, the sample-and-hold circuit includes the series arrangement of a current source 108 also providing the current Ii, third and fourth controllable switches Sw7 and Sw8, and a current source 110 providing the current I2. The junction between the third and fourth controllable switches Sw7 and Sw8 is connected to ground through a capacitor C16 and to a first input of a comparator 112, having a second input connected to ground. The output from the comparator 112 is connected to another input of the logic circuit 96. The third and fourth controllable switches Sw7 and Sw8 have control inputs which are connected, respectively, to outputs of the logic circuit 96. The capacitors C16 and C17 have the same capacitance value.
In a switched-mode power supply, due to the output capacitor C12 having a high value, the change in the DC output voltage is small from one cycle to the next, unless a special situation occurs, e.g., a short circuit at the output. With this in mind, a circuit with two time constants is implemented. In particular, one time constant (τ1) is produced by the current source 102 (108) and the capacitor C16 (C17) while the other time constant (τ2) is produced by the current source 104 (110) and the capacitor C16 (C17). The currents II and I2 and the capacitors C16 and C17 are dimensioned such that the time constant τ1 is equal to the time interval from, for example, t1 to t3, and the time constant τ2 is equal to the time interval from t1 to t2.
In operation, referring to FIGS. 4E and 4F, the logic circuit 96 closes the controllable switches Sw4 and Sw5 (controllable switch Sw6 having already been opened) when the input current I AUX to current mirror 92 exceeds 0.83*I REF (t1), causing the current source 102 to charge the capacitor C16 at the first time constant τ1. At the same time, the logic circuit 96 closes the fourth controllable switch Sw8 causing the current source 110 to discharge the capacitor C17 at the second time constant τ2. When the voltage across capacitor C17 reaches zero, the signal from the comparator 112 causes the logic circuit 96 to open the controllable switches Sw4 and Sw8. Then when the current I AUX drops below 0.83*I REF , the logic circuit opens switch Sw5. In the next cycle, the logic circuit 96 closes the controllable switches Sw4 and Sw7 (controllable switch Sw8 having already been opened) when the input current I AUX to current mirror 92 exceeds 0.83*I REF (t1), causing the current source 108 to charge the capacitor C17 at the first time constant τ1. At the same time, the logic circuit 96 closes the fourth controllable switch Sw6 causing the current source 104 to discharge the capacitor C16 at the second time constant τ2. When the voltage across capacitor C16 reaches zero, the signal from the comparator 106 causes the logic circuit 96 to open the controllable switches Sw4 and Sw6. When I AUX drops below 0.83*I REF , the logic circuit 96 opens the controllable switch Sw7. FIG. 4G shows the switching signal applied to the controllable switch Sw4 by the logic circuit 96. As shown, the controllable switch Sw4 is closed only during the time t1 to t2 (t4 to t5), and as such, the erroneous value of the current I AUX occurring between t2 and t3 (t5 and t6) does not affect the sampled signal stored on the discharge capacitor C15.
Numerous alterations and modifications of the structure herein disclosed will present themselves to those skilled in the art. However, it is to be understood that the above described embodiment is for purposes of illustration only and not to be construed as a limitation of the invention. All such modifications which do not depart from the spirit of the invention are intended to be included within the scope of the appended claims. | A switched-mode power supply includes a transformer having a primary winding, a secondary winding and an auxiliary winding. A switching device is included in series with the primary winding for alternately interrupting the flow of current through the primary winding. The switched-mode power supply further includes a controller circuit connected to the auxiliary winding for receiving information related to an output voltage across the secondary winding and for controlling the switching of the switching device so as to maintain the information at a desired level. The controller circuit including a sample-and-hold circuit which is controlled to sample the information related to the output voltage only when there is current flowing in the secondary winding. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority to U.S. Patent Application No. 61/520,201, filed Jun. 6, 2011, which is incorporated herein by reference in its entirety.
BACKGROUND
People regularly hunt birds, animals, and even other people (e.g., fugitives or enemies) using firearms. Firearms are typically, though clearly not always, used outdoors and are by their very nature dangerous. As such, proper training for firearm use is often emphasized.
Currently, firearm training that uses live fire often occurs at local firing ranges where physical targets are displayed and fired upon in designated, linear areas. Hunting, on the other hand, generally involves traveling to locations having sought prey, and often requires one or more licenses. While some prior art systems use lasers or other non-live fire for training purposes, such systems may fail to provide an accurate experience that fully simulates (or prepares the user for) live fire.
SUMMARY
Virtual environment hunting systems and methods are provided. According to one embodiment, a virtual environment hunting system includes a platform, at least one wall surrounding the platform, at least one projector, at least one housing sensor, at least one shooter sensor, and at least one processor. The at least one wall is separated from the platform by a floor, defines an opening above the platform, and is configured such that all bullets fired to the at least one wall from a shooter on the platform reflect into the floor. The at least one projector is configured to apply images to the at least one wall. The processor is in data communication with the at least one projector, the at least one housing sensor, the at least one shooter sensor, and programming. The programming causing the processor to: (a) actuate the at least one projector to apply images to the at least one wall to represent an environment, the images including a visual representation of prey; (b) determine a trajectory of a fired bullet using data from the at least one housing sensor and the at least one shooter sensor; (c) determine how the trajectory of the fired bullets interacts with the represented environment; and (d) actuate the at least one projector to update the images applied to the at least one wall to account for the trajectory of the fired bullets.
According to another embodiment, a virtual environment hunting system includes a first area having a first platform and at least one wall surrounding the first platform. The at least one wall is separated from the first platform by a first floor, defines an opening above the first platform, and is configured such that all bullets fired to the at least one wall from a shooter on the first platform reflect into the first floor.
BRIEF DESCRIPTION OF THE DRAWINGS
Illustrative embodiments of the present invention are described in detail below with reference to the attached drawings.
FIG. 1 is a sectional view of a virtual environment hunting system according to one embodiment, in use.
FIG. 2 is a block diagram showing certain components of the system of FIG. 1 .
FIG. 3 is a section view of a part of a wall of the system of FIG. 1 .
FIG. 4 is a flow chart showing an exemplary set of steps performed by the system of FIG. 1 .
FIG. 5 shows an alternate embodiment of a housing of the system of FIG. 1 .
DETAILED DESCRIPTION
Firearms have become a common household item, and it is estimated that over seventy million people in the United States alone own at least one firearm. Firearms may be used for a variety of purposes. For example, people may use firearms to defend their homes and workplaces (e.g., shops or banks) against invaders, to hunt animals, to defend against enemies in wars, or for mere recreation.
To improve their shooting accuracy, firearm owners often practice their shooting at firing ranges. One type of firing range generally comprises an enclosed area that is divided into multiple linear shooting lanes. Each shooting lane may include a pulley (or other comparable) system that allows the shooter to set up a target paper within the lane at a desirable distance. The shooter may set up the target paper at the desired distance, shoot at the target paper, and then reel the target paper back towards him to analyze the accuracy of his shots.
This type of a firing range, however, has several drawbacks. Consider, for example, a bird (e.g., pheasant) hunter who uses a conventional firing range to improve his bird hunting skills. In practice, the bird hunter may encounter target birds flying in all directions. The firing range, however, may only allow the bird hunter to practice his shots in a linear direction. Moreover, the target paper may not be shaped like a bird, and the stationery target paper may not prepare the bird hunter to shoot at flying targets. Additionally, the overall ambiance and environment of the firing range may fail to emulate an actual hunting environment (e.g., a forest or hunting ground).
Another type of firing range is less confined and launches clay targets as targets for shooters. Those firing ranges may require a relatively large amount of space, and the movement of the clay targets may fail to accurately depict the flight of a bird.
Because of these drawbacks, the bird hunter may prefer to practice shooting at birds on an actual hunting ground instead of a firing range. This too, however, has its drawbacks. For example, if a bird hunter shoots at a live bird and misses, he may not get any feedback to help him correct his mistake (e.g., the bird hunter may not know whether his shot was too high, or too much to the left, et cetera). Furthermore, shooting on the hunting ground may require costly licenses, and the hunting ground may only be open during particular seasons and not allow the hunter to practice his shooting year round.
Virtual shooting ranges may solve some of these problems. Virtual shooting ranges, akin to certain shooting video games available on the market today, may display targets on a screen and allow a user to shoot at these targets with a dummy gun that emits, for example, infrared signals or lasers. Such virtual shooting ranges, however, have their own drawbacks; the most noticeable of which is that they do not simulate live fire. Those who have fired firearms will appreciate that the experience of firing a live gun, because of gun recoil and other such factors (e.g., loading and reloading, gun heft and feel, et cetera), cannot be accurately replicated with dummy guns.
Attention is now directed to FIG. 1 , which shows a cross sectional view of a virtual environment hunting system 100 in accordance with one embodiment of the current invention. The hunting system 100 comprises a housing or shooting area 102 which generally surrounds a platform 200 . As discussed in more detail below, a user may shoot live rounds at the housing 102 while standing (or sitting, kneeling, et cetera) on the platform 200 .
As people of skill in the art will appreciate, shooting live rounds in an enclosed space presents serious safety concerns. Specifically, a bullet from a firearm (such as a rifle, hand gun, etc.), once it hits a surface of an enclosed space, may ricochet and injure (or even kill) the shooter or others in the vicinity. The housing 102 may be designed to prevent such unintended consequences. While the system 100 is generally described in use with “bullets”, it should be understood that the term “bullet” is used herein both to refer to a single projectile such as that fired from a rifle as well as pellets (or “shot”) such as those fired from a shotgun.
To prevent such unintended consequences, the housing 102 may generally be dome shaped and have a curved portion 104 and a top portion 106 as shown in FIG. 1 . The curved portion 104 may be configured to ensure that a bullet fired by a shooter on the platform 200 does not ricochet back to the platform 200 , irrespective of where it strikes the curved portion 104 , and irrespective of the position of the shooter on the platform 200 . More specifically, a shooter 108 may shoot at the curved portion 104 a bullet having an angled trajectory 110 from a rifle 112 while standing towards a side 200 L of the platform 200 ; as can be seen, the bullet, because of the arced shape of the curved portion 104 , may be reflected along a trajectory 114 into the ground 116 (away from the platform 200 ). Similarly, the shooter 108 may kneel and shoot at the curved portion 104 a bullet having generally horizontal trajectory 118 ; this bullet too, because of the arced shape of the curved portion 104 , may be reflected along a trajectory 120 into the ground 116 . While the trajectories 110 , 118 of two bullets are shown in FIG. 1 , people of skill in the art will appreciate that any bullet shot by the shooter 108 at the curved portion 104 , as he stands, sits, kneels, et cetera on the platform 200 (regardless of whether the shooter 108 is located at the side 200 L, a side 200 R, or anywhere else on the platform 200 ), may ricochet into the ground 116 and not contact the platform 200 . The ground 116 may be configured to ensure that the bullets will not ricochet off it; for example, the ground 116 may comprise loose dirt and be capable of absorbing hundreds of bullets. From time to time, the bullets and shells on the ground 116 may be removed (e.g., by replacing the loose dirt on the ground 116 ).
To ensure that a bullet shot generally vertically by the shooter 108 does not reflect back towards the platform 200 , the top portion 106 may have various configurations. In one embodiment, the top portion 106 is shaped like a cone and have angled walls 106 W. The angled walls 106 W may be tilted so as to deflect any bullet away from the platform 200 . For example, a bullet fired at the top portion 106 along trajectory 122 may be deflected towards the ground 116 along trajectory 124 after hitting the angled walls 106 W more than once. It will be appreciated that a bullet fired at an edge 126 of the top portion 106 may deflect straight back towards the platform 200 , as this bullet may not contact the angled walls 106 W. The edge 126 may thus be constructed of materials configured to absorb and retain bullets (e.g., shock absorbing concrete such as SACON®, or other suitable materials). In other embodiments, the top 126 may be offset from above a center point of the platform 200 . And in still other embodiments, much or all of the walls 106 W may be configured to absorb and retain bullets.
Thus, as has been described, the shooter 108 may stand (or walk around, sit, kneel, lie down, et cetera) on the platform 200 and shoot live rounds anywhere at the housing 102 indiscriminately without risking injury from ricocheting bullets. People of skill in the art will appreciate that the platform 200 may be circular or any other desirable shape (e.g., rectangular, triangular, octagonal, et cetera).
Attention is now directed to FIG. 2 . The hunting system 100 may be interactive, and may include a processor or controller 300 that is in data communication with projectors 302 , platform sensors 304 , housing sensors 306 , shooter sensors 308 , input devices 310 , and output devices 312 . The hunting system 100 may also include a storage unit 314 and a computer memory 316 in data communication with the processor 300 . The storage unit 314 may be, for example, a disk drive that stores programs and data, and the storage unit 314 is illustratively shown storing a program 318 embodying the steps and methods set forth below. It should be understood that the program 318 could be broken into subprograms and stored in storage units of separate computers and that data could be transferred between those storage units using methods known in the art. A dashed outline within the computer memory 316 represents the software program 318 loaded into the computer memory 316 , and a dashed line between the storage unit 314 and the computer memory 316 illustrates the transfer of the program 318 between the storage unit 314 and the computer memory 316 . The processor 300 , the storage unit 314 , and the computer memory 316 may be placed within the housing 102 (e.g., underneath the platform 200 ) or may be external to the housing 102 .
The projectors 302 may be any appropriate type of projectors, for example, HD projectors, LCD projectors, DLP projectors, CRT projectors, et cetera. The projectors 302 may be placed underneath the platform 200 ( FIG. 1 ) and/or on the sides 200 L, 200 R of the platform 200 . The projectors 302 may also be placed within the top portion 106 or the curved portion 104 of the housing 102 . When the projectors 302 are placed within the top portion 106 or the curved portion 104 , protective coverings may be provided to shield the projectors 302 from damage by bullets and ensure proper deflection of bullets.
The projectors 302 may be configured to project videos onto the curved portion 104 and the angled walls 106 W. In some embodiments, the videos may be projected by the projectors 302 on part of the curved portion 104 and/or the angled walls 106 W to create a virtual environment. Alternatively, the videos may be projected by the projectors 302 in continuous fashion on the entire curved portion 104 and/or the angled walls 106 W to generate a virtual environment that surrounds the shooter 108 standing on the platform 200 on all sides. The projectors 302 may also display still images. In some embodiments, the projectors 302 may be 3D projectors that are configured to display 3D images and videos on the curved portion 104 and/or the angled walls 106 W.
The platform 200 may include one or more of the platform sensors 304 , which may be, for example, weight sensors or relays that are configured to determine whether or not the shooter 108 is standing on the platform 200 . Where multiple platform sensors 304 are provided, the platform sensors 304 may also be used to determine the location of the shooter 108 on the platform 200 (e.g., shooter 108 is standing towards the side 200 L of the platform 200 ). The platform sensors 304 may also act as part of a kill switch. More specifically, as discussed in more detail below, the processor 300 may be configured to immediately shut down the projectors 302 and terminate the program 318 as soon as the shooter 108 steps off the platform 200 .
The housing sensors 306 may be any type of sensors that can detect that a bullet has impacted the housing 102 . In the preferred embodiment, the housing sensors 306 may be configured to detect vibrations (for example, the housing sensors 306 may be piezoelectric accelerometers). As shown in FIG. 3 , the curved portion 104 of the housing 102 may include an inner wall 1041 , an intermediate wall 104 B backing the inner wall 1041 , and an outer wall 1040 . The inner wall 1041 of the curved portion 104 may be metallic, and in conjunction with the intermediate wall 104 B and the outer wall 1040 , may be configured to deflect bullets towards the ground 116 . Multiple housing sensors 306 may be secured at known intervals to the intermediate wall 104 B. These housing sensors 306 may also be in contact with the inner wall 1041 . A shooter 108 standing on the platform 200 may shoot a bullet B having a trajectory A at the inner wall 1041 , which may cause vibrations to flow along the inner wall 1041 in direction D. The housing sensors 306 may be configured to evaluate these vibrations to enable the processor 300 to quantify the point of impact of the bullet B on the inner wall 1041 .
Specifically, as will be appreciated, the vibrations from the bullet B will reach different housing sensors 306 at different times depending on the proximity of the housing sensors 306 to the point of impact (i.e., a housing sensor 306 that is closer to the point of impact of the bullet B on the inner wall 1041 may detect these vibrations before a housing sensor 306 that is further away from the point of impact.) Based on the different times at which these vibrations are detected by the various housing sensors 306 , and the known distances between the various housing sensors 306 , the processor 300 may triangulate the point of impact of the bullet B on the inner wall 1041 with precision. The top portion 106 of the housing 102 may similarly include housing sensors 306 to determine the point of impact of a bullet that strikes the angled walls 106 W. In other embodiments, the sensors 306 may for example include audio and/or optical sensors.
Additional information may be provided to the processor 300 by the shooter sensors 308 . The shooter sensors 308 may be configured to determine or approximate the location of the firearm 112 when the bullet B is fired by the shooter 108 . By way of example, the shooter sensors 308 may be optical or audio position sensors that have an emitting element and sensing elements. The emitting element may for example be adhered to the firearm 112 (e.g., on the scope of a rifle or the butt of a handgun) or incorporated into the apparel of the shooter 108 (e.g., on a shooter's earmuffs or helmet). The corresponding sensing elements may reside within the platform 200 or the housing 102 . The emitting element may emit, for example, laser beams or radio frequency waves that are sensed by the sensing elements. The processor 300 , based for example on the time that elapses between the emissions by the emitting element and the sensing by the sensing element, the known speed of the emissions, and the strength of the received signal, may triangulate or otherwise determine the location of the firearm 112 at the time the bullet B was fired by the shooter 108 . From this information, the processor 300 may ascertain whether the shooter 108 was kneeling on the platform 200 as he fired the bullet B, or whether the shooter 108 was standing up or lying down, et cetera while firing. Where the platform sensors 304 are configured to determine the position of the shooter 108 on the platform 200 , the processor 300 may nevertheless triangulate the position of the shooter 108 on the platform 200 using the shooter sensors 308 to verify (or determine with improved accuracy) the position of the shooter 108 —and particularly the firearm 112 . People of skill in the art will appreciate that the number of sensing elements and emitting elements of the shooter sensors 308 need not be equal, and that positioning of the sensing elements and emitting elements may be reversed.
The input devices 310 may include, for example, a keyboard, a mouse, a microphone, et cetera. The input devices 310 may be wired to the processor 300 or may be configured to communicate with the processor 300 wirelessly (e.g., over a wireless internet or intranet network). As discussed in more detail below, the input devices 310 may allow an administrator or user of the virtual hunting system 100 to access, configure, and tailor the program 318 to meet the specific requirements of the user. The output devices 312 may include, for example, printers, speakers, video and/or audio recorders, et cetera.
Attention is now directed to FIG. 4 , which shows example steps performed by the processor 300 in accordance with the program 318 according to one embodiment. The program 318 begins at step 400 , and at step 402 asks the shooter 108 whether he would like to select a shooting environment 403 . This inquiry (and the remaining inquiries) may for example be displayed by the projectors 302 for the shooter 108 on the inner wall 1041 of the curved portion 104 . The shooter 108 may respond to the inquiries by using one or more of the input devices 310 . If the shooter 108 conveys that he does not want to select a shooting environment 403 , the program 318 may end at step 402 E (or alternatively, randomly select a shooting environment 403 for the shooter 108 ). If, on the other hand, the shooter 108 answers at step 402 that he would like to select a shooting environment 403 , at step 404 , the program 318 may cause the projectors 302 to display various available shooting environments 403 . By way of example, these shooting environments 403 may include a hunting environment 403 A and a military environment 403 B.
The hunting environment 403 A may be configured to emulate hunting experiences. For example, selection of the hunting environment 403 A may cause the projectors 302 to display onto the inner wall 1041 of the curved portion 104 and the angled walls 106 W of the top portion 106 a forest as it appears during the day time, a hunting ground as it appears at dusk, a wooded area with a water body as it appears in the evening, et cetera. The military environment 403 B may be configured to emulate militaristic scenarios. For example, if the shooter 108 chooses the military environment 403 B, the projectors may simulate residential areas with tanks and other military vehicles and weapons, et cetera. It will be appreciated that the hunting environment 403 A and the military environment 403 B are exemplary only and that various other environments 403 C may be provided (e.g., a futuristic environment depicting robots and space vehicles, a medieval environment with knights on horses, an environment simulating a burglary, an environment simulating a kidnapping, et cetera).
The shooting environments 403 may be customized further to meet the unique requirements of the shooter 108 . For example, if the shooter 108 chooses the hunting environment 403 A at step 404 , then at step 406 the program 318 may inquire whether the shooter 108 wishes to shoot at birds, deer, or other animals. Similarly, if the shooter 108 had chosen a military environment 403 B, the program 318 could have inquired at step 406 , for example, whether the shooter 108 wishes to emulate the Cold War, World War I or II, the Iraqi invasion, et cetera.
Assume that the shooter 108 chooses birds at step 406 . At step 408 , then, the program 318 may provide the shooter 108 with different types of birds to choose from (e.g., pheasants, doves, ducks, et cetera). If the shooter 108 had chosen the military environment 403 B at step 404 and the Iraqi invasion at step 406 , for example, then at step 408 , the program 318 may have inquired whether the shooter 108 wishes to practice his shooting in a crowded or uncongested area. For purposes of illustration, ducks 411 have been chosen at step 408 in FIG. 4 .
Steps 402 , 404 , 406 , 408 in the embodiment of FIG. 4 may be collectively thought of as setup or user input steps. Those skilled in the art will appreciate that some (or even all) of those steps may be combined together or omitted, and that additional setup steps may be included. For example, the type of firearm 112 and ammunition and/or a duration (e.g., one hundred targets, one hundred shots, a time limit, etc.) may be selected.
At step 410 , the program 318 may cause the projectors 302 to project onto the internal wall 1041 and/or the angled walls 106 W one or more target ducks 411 (see FIG. 1 ). The ducks 411 may be displayed as being at rest or in flight, and the ducks 411 may be blended in with the hunting environment 403 A (e.g., the ducks 411 may be shown as resting in a pond) which may remain stationary or which may constantly change to simulate wind, cloud cover, or other environmental factors. At the same time, the program 318 may cause the speakers 312 to provide audio inside the housing 102 to further simulate the hunting environment and prey.
After causing the projectors 302 to display the target ducks 411 , the processor 300 may poll the housing sensors 306 to determine whether the bullet B has been fired by the shooter 108 . If the housing sensors 306 indicate that the bullet B has been fired (i.e., if some or all of the housing sensors 306 detect significant vibrations), then at step 414 the program 318 may determine the point of impact of the bullet B on the internal wall 1041 and/or the angled walls 106 W (e.g., through triangulation). As discussed above, the processor 300 may quantify the point of impact of the bullet B by using the difference in the times at which the vibrations caused by the bullet B are detected by the various sensors 306 , and the known distance between these sensors 306 .
At step 416 , the processor 300 may determine the location of the shooter 108 on the platform 200 —and specifically the location of the firearm 112 —at the time the bullet B was fired by using the platform sensors 304 and/or the shooter sensors 308 . At step 418 , as discussed above, the processor 300 may also determine whether the shooter 108 was standing up, kneeling, lying down, et cetera while shooting the bullet B by using the shooter sensors 308 .
At step 420 , the processor 300 may determine whether the bullet B struck any of the target ducks 411 . Specifically, the processor 300 may keep track of the location of the projected target ducks 411 on the inner wall 1041 and/or the angled walls 106 W at all times. The processor 300 may also determine the time of impact of the bullet B by using the housing sensors 306 , and may determine the trajectory of the bullet B using the firing location, the point of impact, and information about the firearm 112 and the bullet B such as orientation of the firearm 112 (which may be provided by a gyroscope attached to the firearm 112 , through analyzing visual data captured by the video recorder 312 , etc.), velocity of the bullet B upon firing, the shape of the bullet B, et cetera. The processor 300 may then compare the location of the target ducks 411 to the trajectory of the bullet B and determine whether the bullet B struck any of the target ducks 411 .
If the bullet B did not strike a target duck 411 , then at step 421 the processor 318 may save the information from steps 414 to 420 in a report 421 R and loop back to step 412 to wait for the next bullet B. If, on the other hand, the processor 300 determines that the bullet B struck a duck 411 , the processor 300 may save the information from steps 414 to 420 in the report 421 R at step 422 and simulate death of the duck 411 at step 424 . For example, the processor 300 may cause the projectors 302 to display the duck 411 falling down from flight onto the ground. Next, at step 426 , the processor 300 may project one or more other target ducks 411 , and according to step 428 , repeat steps 412 to 426 until a run time 427 elapses. Steps 412 , 414 , 416 , 418 , 420 , 421 , 422 , 424 , 426 may be repeated very quickly to analyze shots fired in quick succession (or generally simultaneously, such as with shotgun shot).
The run time 427 may be, for example, a fixed length of time such as ten minutes, twenty minutes, an hour, et cetera. Alternatively, the run time 427 may be performance based; for example, the run time 427 may elapse when the shooter 108 successfully shoots down (or misses) ten target ducks 411 , twenty target ducks 411 , et cetera. After the run time 427 elapses, the processor 300 may finalize the report 421 R. The program 318 may then end at step 432 .
Those skilled in the art will appreciate that various described steps may occur in different orders, and that steps may be omitted or added. For example, in some embodiments, step 416 and step 418 may occur before step 414 ; or step 418 may be omitted.
The report 421 R may be, for example, computer printouts that outline the performance of the shooter 108 . For example, the report 421 R may include the number of target ducks 411 that the shooter 108 was able to shoot successfully, and the number of bullets B that were off-target. In the case of shotgun shot, the number of off-target shots taken (instead of the number of bullets B) may be provided. In addition, the report 421 R may include, for example, the number of ducks 411 that the shooter 108 was able to shoot in the head or body, as opposed to the wing. The report 421 R may also include suggestions for the shooter 108 . For example, the report 421 R may outline that the shooter 108 is generally off-target towards the left and that the he should aim further towards the right. Or, for example, the report 421 R may convey that the shooter 108 was kneeling when he should have been standing up, or that the shooter 108 should have moved to the left 200 L of the platform 200 to get a clear line of sight to shoot a duck 411 that was otherwise obstructed by a tree. The report 421 R may also include a video and audio recording of the shooter's experience with the virtual hunting system 100 , captured by the output device(s) 312 . The shooter 108 may utilize the video and the instructional feedback in the report 421 R to improve his shooting.
In some embodiments, the program 318 may allow the shooter 108 to shoot at the target ducks 411 with different types of firearms and ammunition. For example, shooter 411 may shoot at the first ten target ducks 411 with a twelve gauge shotgun 112 , and at the next ten target ducks 411 with a twenty gauge shotgun 112 . For different types of prey, a rifle 112 , a nine mm handgun 112 , a .38 caliber pistol 112 , etc. may be used. As people of skill in the art will appreciate, parameters of the calculations performed by the processor 300 may vary based on the type of firearm and ammunition; for example, the duration between firing and impact on the housing 102 may be different for different types of firearms and ammunition. Similarly, the vibrations sensed by the housing sensors 306 may be different for different firearms (e.g., the housing sensors 306 may sense greater vibrations from a bullet fired by a nine mm handgun than from a bullet fired by a .22 caliber handgun). The program 318 may allow the shooter 108 to input via the input devices 310 the types of firearms 112 and ammunition that the shooter 108 wants to shoot with so that the processor 300 accounts for them in its computations. In some embodiments, the program 318 may allow the shooter 108 to enter these and other preferences into the system 100 by using a firearm instead of the input devices 310 (i.e., the program may display the options and allow the shooter 108 to choose a particular option by shooting at it).
As set forth above, while the system 100 is generally described in use with “bullets”, it should be understood that the term “bullet” is used herein both to refer to a single projectile such as that fired from a rifle as well as pellets (or “shot”) such as those fired from a shotgun. When a shotgun and shot are used, it may be desirable for the processor 300 to track the travel of all or substantially all of the pellets in the manner discussed above, treating individual pellets in generally the same way that a projectile from a rifle is treated.
The program 318 may also be configured to generate targeted advertisements for the shooter 108 by using the report 421 R. For example, if the report 421 R indicates that the shooter 108 is unable to consistently hit the chosen target with the rifle 112 but that the shooter 108 is able to consistently hit the chosen target with a 9 mm handgun and a .38 caliber pistol, the report 421 R may suggest that the shooter 108 purchase a different rifle 112 , a different type of rifle 112 , different ammunition for the rifle 112 , a scope, et cetera. The program 318 may also include for the shooter 108 coupons and other promotional offers from stores in the area where such items may be purchased. Similarly, if the report 421 R indicates that the shooter 108 is unable to consistently shoot the chosen target with any type of firearm, then the report 421 R may suggest that the shooter 108 retain a personal trainer and provide to the shooter 108 promotional offers from such personal trainers. An owner (or administrator) of the hunting system 100 may charge the shooter 108 to use the system 100 , and/or the targeted advertisements may generate revenue for the owners. Further, the video and audio recording of the experience (captured by the output devices 312 ) may be made available (e.g., online or through a disc or other media), either for a fee or free of charge, and with or without advertising added.
As discussed above, when the shooter 108 successfully shoots at a target duck 411 , at step 424 , the program 318 may simulate death of the duck 411 (e.g., display the duck 411 falling down). In some embodiments, the simulation may be more interactive. Consider, for example, that the shooter 108 chooses the military environment 403 B as the shooting environment 403 . The processor 300 may then cause the projectors 302 to display enemy targets (e.g., enemy soldiers on foot, enemy soldiers in tanks, et cetera). The projected enemy targets may be configured to shoot back at the shooter 108 . In this embodiment, the platform 200 may (but need not) include barricades (e.g., barrels, walls, et cetera) which the shooter 108 may use to evade the projected enemy fire. The processor 300 may determine whether the projected enemy fire struck the shooter 108 by evaluating the known trajectories of the enemy fire along with the position and location of the shooter 108 on the platform 200 as ascertained via the platform sensors 304 and the shooter sensors 308 . The report 421 R may outline whether the shooter 108 was struck by enemy fire, and the steps that the shooter 108 could have taken to better evade the enemy fire.
According to another embodiment, the virtual environment hunting system 100 may include multiple housings 102 that are in data communication with each other. For example, a warehouse or other such structure may include four separate housings 102 to enable four different shooters 108 to simultaneously experience the virtual environment of the hunting system 100 . Or the housings 102 may be remote from each other but connected through a network. Each of the housings 102 may display on their inner walls 1041 and the angled walls 106 W the same shooting environment 403 , either from the same or different vantage points. Consider, for example, that the four shooters 108 choose the hunting environment 403 A as the shooting environment 403 and the ducks 411 as targets. Then, a duck 411 that is shot by one of the shooters 108 may be displayed as being shot in all four housings 102 . Each of the four shooters 108 may attempt to shoot the ducks 411 before the ducks 411 are shot by the other three shooters 108 . The report 421 R may include the number of target ducks 411 that each shooter 108 shot successfully, to enable the shooters 108 to compare their performances with each other. The report 421 R may also include other information. For example, the report 421 R may outline which shooter 108 was most accurate (i.e., had the best ratio of shots fired versus targets 411 struck), or where applicable, which shooter 108 was best able to evade enemy fire. Such versatility may make the hunting system 100 particularly attractive for militaristic applications (e.g., for conducting comparative tests on a large scale). Families and friends may also enjoy interacting with each other via the hunting system 100 in this fashion.
In some embodiments, the shooting environment 403 of the interconnected housings 102 may allow the shooters 108 to shoot at (the projections of) other shooters 108 . Consider, for example, a hunting system 100 that includes two housings 102 that are in data communication with each other. The projectors 302 of each housing 102 may display on the inner wall 1041 and the angled walls 106 W a target that emulates the shooter 108 in the other housing 102 . For example, if a shooter 108 in one housing 108 is kneeling behind a barricade on the platform 200 , the target in the other housing 102 may be projected as kneeling behind a barricade. Alternatively, a video of the actual shooter 108 in one housing 102 may be projected in the other housing 102 in real time. The shooters 108 may thus safely shoot at each other (i.e., at the projections of each other) with live rounds.
As noted above, for safety, it is important that the shooters 108 stay on the platforms 200 while shooting, as otherwise, the shooters 108 may be struck unintentionally with ricocheting bullets. The processor 300 may thus be configured to continuously poll the platform sensors 304 to ensure that the shooters 108 are situated on the platform 200 . If the platform sensors 304 indicate that a shooter 108 has stepped off the platform 200 , even momentarily, the processor 300 may generate an audible warning signal and immediately shut down the program 318 , including the projectors 302 , and not restart the program 318 until the shooter 108 steps back onto the platform 200 . In some embodiments, if a shooter 108 steps off the platform 200 , the processor 300 may terminate the program 318 and not restart the program 318 until an administrator of the system 100 follows up with the shooter 108 .
While each housing 102 and platform 200 have been described herein as accommodating a single shooter 108 at a time, it will be appreciated by those skilled in the art that the housing 102 and the platform 200 may be designed to accommodate multiple shooters 108 simultaneously. Additionally, the housing 102 need not be generally dome shaped as shown in FIG. 1 . Rather, the housing 102 may take any shape, so long as it is ensured that bullets will not reflect off the walls of the housing 102 onto the platform 200 . As shown in FIG. 5 , for example, a housing 502 generally shaped as a pyramid may be used for the virtual environment hunting system 100 .
Many different arrangements of the various components depicted, as well as components not shown, are possible without departing from the spirit and scope of the present invention. Embodiments of the present invention have been described with the intent to be illustrative rather than restrictive. Alternative embodiments will become apparent to those skilled in the art that do not depart from its scope. A skilled artisan may develop alternative means of implementing the aforementioned improvements without departing from the scope of the present invention. It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations and are contemplated within the scope of the claims. Not all steps listed in the various figures need be carried out in the specific order described. | One virtual environment hunting system includes a platform, a wall surrounding the platform, a projector system configured to apply images to the wall, and at least one processor. The wall is separated from the platform by a floor, defines an opening above the platform, and is configured such that all bullets fired to the wall from a shooter on the platform reflect into the floor. Programming causes the processor to: (a) actuate the projector system to apply images to the wall to represent an environment; (b) determine a trajectory of a fired bullet using data from at least one housing sensor and at least one shooter sensor; (c) determine how the trajectory of the fired bullets interacts with the represented environment; and (d) actuate the projector system to update the images applied to the wall to account for the trajectory of the fired bullets. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an apparatus for grinding semiconductor wafers, and more particularly to means for keeping a semiconductor wafer, which is fixedly held on the wafer-gripping surface, parallel to the grinding surface of the grinding means in the semiconductor wafer grinding apparatus.
2. Description of Related Art
FIG. 8 shows a conventional grinding apparatus 100 having a semiconductor wafer holder 117 and a grinding means 107 set up on its L-shaped stand. A screw rod 102 is rotatably fixed to the rear side of the vertical wall 101 of the L-shaped stand, extending parallel to the vertical wall 101. The screw rod 102 is driven by an associated power drive 103 so that its movable part 104 may be moved up and down. The movable part 104 has a slide 105 integrally connected thereto for moving on vertical rails 106 laid on the front side of the vertical wall 101. The slide 105 carries grinding means 107. The vertical position of the movable part 104 can be determined by a linear scale 108, which is fixed to the rear side of the vertical wall 101.
The grinding means 107 comprises a spindle 109 and a spindle housing 110 for rotatably holding the spindle 109, which has a grindstone mount 111 on its end. The grindstone mount 111 has a grinding wheel 113 fixed to its bottom, and a grindstone 112 is attached to the grinding wheel 113, which can be rotated by the spindle 109.
The rotary holder 117 is positioned on the base 114 of the L-shaped stand. It can be rotated by an associated servomotor 116, which has an encoder 115 equipped therewith. The wafer-gripping surface 118 of the rotary holder 117 can hold a semiconductor wafer by applying a negative pressure to the semiconductor wafer. The rotary holder 117 is seated on a support member 119, which has three level adjusting screws 120 equal angular distance apart from each other, thereby permitting the wafer-gripping surface 118 to be set parallel to the grindstone 112.
In operation a selected semiconductor wafer is put on the wafer-gripping surface, which is sucked and fixedly held thereon. The spindle 109 is put in rotation, and at the same time, the grinding means 107 is lowered. The spindle 109 is rotated at high speeds, and accordingly the grinding wheel 113 is rotated at high speeds. The rotating grindstone 112 is pushed against the semiconductor wafer to make its surface smooth by rubbing on the hard grindstone 112.
In grinding it is required that the grinding accuracy be increased to the extent that the wafer has an even thickness over its whole area with keeping the total thickness variation (TTV) constant as possible. To meet this requirement it is necessary that the wafer-gripping surface 118 is put in exact parallelism relative to the undersurface of the grindstone 112.
The rotary holder 117 and the grinding means 107 are set up very carefully to assure the strict parallelism as required therebetween. No matter how carefully these parts may be set up, however, a minimum misalignment in the order of several microns cannot be reduced. To reduce such a minimum misalignment the three leveling screws 120 are used in the grinding apparatus 100.
As a recent tendency the degree of integration in semiconductor devices has been increasing, and the semiconductor wafer size has been increasing, too. Accordingly it is required that the permissible minimum misalignment be reduced to the order of nanometer. The leveling screws 120, however, cannot meet such requirement.
SUMMARY OF THE INVENTION
One object of the present invention is to provide a grinding apparatus equipped with means for putting semiconductor wafers in most strict parallelism relative to the undersurface of the grindstone.
To attain this object an apparatus for grinding semiconductor wafers comprising at least means for holding semiconductor wafers and means for grinding semiconductor wafers is improved according to the present invention in that said means for holding semiconductor wafers comprises holder means having wafer-gripping surface for sucking and holding semiconductor wafers and liquid bearing means for rotatably supporting said holder means, said liquid bearing means having inclination control means formed therein, said inclination control means including first, second and third sets of inclination controlling areas for suspending said holder means, each having first and second pockets formed at upper and lower levels, said first set of inclination controlling area having a first flow rate control means connected thereto, said second set of inclination controlling area having a second flow rate control means connected thereto, and said third set of inclination controlling area having a third flow rate control means, whereby the parallelism of said wafer-gripping surface relative to said means for grinding is assured by controlling the flow rate of the liquid to each of said first, second and third sets of inclination controlling areas.
Said first, second and third sets of inclination controlling areas may have first, second and third channels respectively connected to a pressurized liquid supply in common, said first, second and third channels having first, second and third flow rate controlling means equipped therewith.
Each of said first, second and third flow rate controlling means may include a liquid inlet, first and second liquid outlets and a branching section for separating the flow of liquid from said liquid inlet and for directing the flow of liquid thus separated to said first and second liquid outlets, said first and second liquid outlets being connected to said first and second pockets respectively.
Each of said first, second and third flow rate controlling means may include a cylinder, a piston slidably fitted in said cylinder with a very narrow gap left therebetween, thereby defining said branching section, said piston having means for setting the initial position thereof in said cylinder, said cylinder having said liquid inlet formed at its intermediate section, and said first and second liquid outlets formed at its opposite sides, thereby permitting the liquid from said liquid inlet to flow to said first and second liquid outlets via said very narrow gap, whereby the flow rates to said first and second liquid outlets may be controlled by permitting the liquid to flow in said very narrow gap in opposite directions and by adjusting the distances of said very narrow gap passage from said liquid inlet to said first and second liquid outlets. Said liquid may be water.
With the above described arrangement the holder means is supported at three selected areas at which the flow rates of the liquid to be supplied there are so controlled that the wafer-gripping surface may be put in the parallelism of nanometer order relative to the bottom surface of the grindstone.
The parallelism as required can be easily attained simply by controlling the flow rates of the liquid to the three pockets, and the parallelism thus attained can be retained in stable condition. Water used in the liquid bearing has the effect of increasing the rigidity of the established suspension system, thereby permitting the parallelism once attained to be retained with precision, and advantageously there is no fear of contamination of semiconductor wafers.
Other objects and advantages of the present invention will be understood from the following description of a semiconductor wafer grinding apparatus having equipped with parallelizing means according to the present invention, one embodiment of which is shown in accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the grinding apparatus according to the present invention;
FIG. 2 illustrates the holder means of the grinding apparatus;
FIG. 3 is a plane view of the holder means, showing its inclination controls;
FIG. 4 shows how the holder means are connected to the pressurizing liquid supply via the flow rate control means;
FIG. 5 is a front view of the flow rate control means;
FIG. 6 is a longitudinal section of the flow rate control means;
FIG. 7 illustrates how the liquid flows into the flow rate control means to be separated and discharged; and
FIG. 8 illustrates a conventional grinding apparatus.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, a semiconductor wafer grinding apparatus 10 comprises: on its L-shaped stand, wafer cassettes 11 and 12 for storing semiconductor wafers W; means 13 for taking semiconductor wafers W out from the wafer cassette 11 and putting them in the wafer cassette 12; centering tables 14 and 15 for centering semiconductor wafers W; first and second transporting means 16 and 17; a turntable 22 having four holders 18 to 21 thereon, each holder having wafer-gripping surface for sucking and holding a selected semiconductor wafer W thereon; grinding means 23 and 24 for grinding semiconductor wafers W on the holders 18 to 21; and washing means 25 for washing each holder.
The cassette 11 contains a pile of wafers W to be ground, and these wafers W are brought one after another to the centering table 14 by the transporting means 13. After the required centering is effected on the wafer W, it is sucked by the first transporting means 16. Then, the first transporting means 16 is made to turn and bring the wafer W to the washing area 34. After the wafer W is washed there, it is put on a selected holder 18 in the turntable 22. The washing area 34 uses a disk having six brushes fixed thereon, permitting water to be flushed between adjacent brushes or from each brush while the disk is rotated.
When the turntable 22 is rotated a predetermined angle (for instance, 90 degrees if it has four holders as in this particular embodiment), a selected holder 18 bearing a semiconductor wafer W is brought under the coarse-grinding means 23, and then, the subsequent holder 19 is brought to the place which was occupied by the preceding holder 18. A subsequent semiconductor wafer W is taken out from the cassette 11 to be put on the centering table 14. After centering, the second wafer W is brought to the washing area 34. After the second wafer W is washed, it is put on the holder 19. The first wafer W is coarse-ground by the grinding means 23.
The turntable 22 is rotated another predetermined angle subsequent to the coarse-grinding of the first wafer W to bring and put the first wafer W under the fine-grinding means 24. The first wafer W is fine-ground there. At the same time, the subsequent wafer W is coarse-ground by the coarse-grinding means 23.
The coarse- and fine-grinding means 23 and 24 can be moved up and down on the vertical wall 26 of the L-shaped stand. These grinding means 23 and 24 are same in structure, and therefore their parts are indicated by same reference numerals in the following description. A pair of rails 28 are laid on the upright wall 26 to carry a slide plate 29, which can be driven along the rails 28 by an associated power drive 27. The grinding means 23 or 24 is fixed to the slide plate 29.
The grinding means 23 or 24 has a rotary spindle 30 rotatably supported in its housing, and the rotary spindle 30 has a grinding wheel 32 fixed to its end via an associated mount 31. The grinding wheel 32 has a grindstone 33 fixed to its bottom. The coarse-grinding means 23 has a coarse grindstone attached thereto whereas the fine-grinding means 24 has a fine grindstone attached thereto.
When the turntable 22 turns still another predetermined angle, the holder 18 bearing the fine-ground wafer W is brought close to the second transporting means 17, and then the fine-ground wafer is brought to the washing station 35 by the second transporting means 17. At the washing station 35 the wafer W is put on a spinner table while being washed with water. In place of water NaOH at a raised temperature ranging from 70 to 80 degrees C. may be used to remove grinding distortion or prominent saw marks, if any. After being washed the wafer is brought to the centering table 15 by the second transporting means 17.
After centering the wafer W, it is picked up and put in the cassette 12 by the transporting means 13. In this way semiconductor wafers are coarse- and fine-ground sequentially to be put in the cassette 12.
When the holders 18 to 21 are contaminated with debris, a holder washing station 25 is put in operation. It comprises a holder washing part 38, a carrier 36 for bearing and transporting the holder washing part 38, a pair of horizontal rails 37 and a vertical drive 39 for moving the holder washing part 38 up and down. In operation the holder washing part 38 is lowered close to holders to be washed, and the carrier 36 is made to traverse along the rails 37 a certain distance across the turntable 22 while the holder washing part 38 is rotated, thereby washing all holders 18 to 21 one after another.
As seen from FIG. 1, parallelism controlling panels 40 each allotted to each of the holders 18 to 21 appear on the opposite sides of the base of the L-shaped stand.
Referring to FIG. 2, the holder 18 (19, 20 or 21) has a wafer-gripping surface 41 on its top. The holder 18 is suspended rotatably by a liquid bearing device 42, and is connected to an associated servomotor 44 via a clutch 43. Thus, the holder 18 can be rotated by the servo motor 44 while being suspended by the liquid bearing device 42. The holder 18 (19, 20 or 21), the liquid bearing 42, the clutch 43 and the servo motor 44 make up together a wafer holding means 45.
The liquid bearing device 42 is a hollow cylinder having an annular U-shaped shelf formed close to its top, functioning as a thrust bearing to support the holder 18 (19, 20 or 21) vertically in floating condition. The thrust bearing functions as an inclination control means, too. In addition, a radial bearing 47 is formed on the inner surface of the center hole of the cylinder, thereby supporting the holder 18 (19, 20 or 21) radially.
As seen from FIG. 3, the inclination control means 46 has a plurality of ejection ports 48 arranged in circular arcs both on the top and bottom surfaces of the annular shelf. These ejection ports 48 are grouped in three circular arc areas. The three circular arc areas on the top side of the annular shelf are called first pockets" 49 whereas the three circular arc areas on the bottom side of the annular shelf are called second pockets" 50. The first and second pockets aligned vertically make up first, second and third inclination controlling areas 51, 52 and 53.
Referring to FIG. 4, first, second and third flow rate control means 54, 55 and 56 are positioned in first, second and third feeding passages 58a, 58b and 58c extending from a pressurized liquid supply 57 to the first, second and third inclination controlling areas 51, 52 and 53 respectively, thereby permitting the liquid to be fed to the different areas at separately controlled pressure. Drainage ports 59 are formed to confront the rotary axle of the holder 18 (19, 20 or 21), thereby allowing the liquid to be discharged outward from the inclination controlling areas 51, 52 and 53.
Referring to FIG. 5, each flow rate controlling means 54, 55 or 56 is a piston-and-cylinder assembly, which has a liquid inlet 61 formed at the intermediate position of the cylinder 60, and first and second liquid outlets 62 and 63 formed at either side of the liquid inlet 61.
The cylinder 60 has a rotary knob 64 attached to its left end, and a scale 66 formed on its right side. The scale 66 has pointers 65 and 66 horizontally movable with rotation of the knob 64. The cylinder 60 has a bracket 67 fixed thereto, permitting the flow rate controlling means 54, 55 or 56 to be fixed to either side of the L-shaped stand, as indicated at 40 in FIG. 1.
Referring to FIG. 6, the flow rate controlling means 54, 55 or 56 has a branching section 69 for separating the flow of liquid from the liquid inlet 61 into two separate flows to direct to the first and second liquid outlets 62 and 63. When the liquid is made to flow into the branching section 69 from the pressurized liquid supply 57 through the liquid inlet 61, and then, the separate flows are discharged from the first and second liquid outlets 62 and 63. The liquid is directed from the first liquid outlet 62 to the first pocket 49, and from the second liquid outlet 63 to the second pocket 50. The liquid may be oil or water. Water is preferably used because it has the effect of increasing the rigidity of the liquid-suspension system to maintain the parallelism of the wafer-gripping surface 41 relative to the grindstone with good precision.
Specifically the branching section 69 is formed by the hollow cylinder 60 and the piston 70 movable therein. A rotary axle 71 projects from the left end of the cylinder 60 to be maintained horizontal by a flange 73, which is press-fitted and fixed to the left end of the cylinder 60 with bolts 72. The rotary axle 71 is rotatably supported a radial bearing 74, and it has a knob 64 fixed to its end. The knob 64 may be positively fixed to the rotary axle 71 by inserting and driving a screw in its tapped hole 75 until the screw has abutted against the rotary axle 71.
The rotary axle 71 has a screw rod 76 integrally connected thereto, and the screw rod 76 is inserted in the elongated cavity 78 of one of the opposite shafts 77 of the piston 70 in non-contact condition. The screw rod 76 can be rotated by rotating the knob 64. The piston shaft 77 has a cap 81 fixed to its end by bolts 82, and a nut 79 is fixed to the cap 81 by bolts 80. The screw rod 76 is threadedly engaged with the nut 79. Thus, rotation of the knob 64 causes the nut 79 to move horizontally through the agency of the rotary screw rod 76, and accordingly the piston shaft 77 moves horizontally. Each piston shaft 77 has O-ring 83 fixed to its end to prevent leakage of water.
As seen from FIG. 6, the piston 70 is larger in diameter than either shaft 77. The right shaft 77 has a pointer 65 fixed to its right end with a stud bolt 84. It is moved horizontally with the shaft 77 to indicate the instantaneous position on the scale 66, which is fixed to the right end of the cylinder 60 with a stud bolt 85.
A very narrow gap 86 of several tens of micrometers is defined between the piston 70 and the hollow cylinder 60, thereby allowing the liquid flowing in the cylinder 60 from the liquid inlet 61 to the first and second liquid outlets 62 and 63. As shown in FIG. 6, the hollow cylinder 60 has an annular groove 87 made at its center, thereby permitting the liquid flowing in the hollow cylinder 60 to run on the circumference of the piston 70.
Referring to FIG. 7, the circumferential gap 86 is L1 plus L2 long, where L1 stands for the length measured from the left side wall 88 of the annular groove 87 to the left end 70a of the piston 70, and L2 stands for the length measured from the right side wall 89 of the annular groove 87 to the right end 70b of the piston 70. These lengths L1 and L2 vary with the instantaneous position of the piston 70 relative to the liquid inlet 61.
The flow rate of the liquid directed from the liquid inlet 61 to the first liquid outlet 62 varies inversely with the gap length L1, and the flow rate of the liquid directed from the liquid inlet 61 to the second liquid outlet 63 varies inversely with the gap length L2. Specifically when the center of the piston 70 is put in alignment with the center of the annular gap 87, the flow rate from the first liquid outlet 62 is equal to that from the second liquid outlet 63 (equilibrium condition). When the piston 70 is shifted rightward (L1<L2), the flow rate from the first liquid outlet 62 is larger than in equilibrium condition, and the flow rate from the second liquid outlet 63 is smaller than in equilibrium condition. Conversely when the piston 70 is shifted leftward (L1>L2), the flow rate from the first liquid outlet 62 is smaller than in equilibrium condition, and the flow rate from the second liquid outlet 63 is larger than in equilibrium condition.
As the knob 64 is rotated to move the piston 70, the ratio of the flow rate from the first liquid outlet 62 to that from the second liquid outlet 63 varies, and accordingly the ratio of the amount of liquid ejecting from the ejection ports 48 of the upper, first pocket 49 to that of liquid ejecting from the ejection ports 48 of the lower, second pocket 50 varies, and accordingly the inclination of the holder, and hence the wafer-gripping surface 41 varies so that its parallelism may be controlled relative to the confronting grindstone 33. The worker can determine the instantaneous position of the piston from the pointer 65 and the scale 66 to know how the liquid is distributed.
As may be understood from the above, the flow rates from the first and second liquid outlets 62 and 63 can be controlled simply by rotating the knob 64 for changing the distances L1 and L2 from the liquid inlet 61 to the first and second liquid outlets 62 and 63, thus permitting the parallelism of the wafer-gripping surfaces 41 relative to the grindstone to be controlled in the order of nanometer, beyond what would be possible with the conventional screw adjustment as described above.
The flow rate controlling means is preferably connected to the inclination controlling means for instance, by using a rotary joint, which is fixed to the rotary axle of the turntable 22 lest the joint should interfere with rotation of the turntable.
As may be apparent from the above, a semiconductor wafer grinding apparatus according to the present invention has wafer holders each suspended at three points, particularly in three sets of inclination controlling areas, in which the liquid is distributed at controlled pressure to put the wafer-gripping surface in strict parallelism relative to the confronting grindstone with such a precision that the conventional mechanical adjustment cannot attain, say in the order of nanometer. Accordingly semiconductor wafers thus ground can have equal thickness (constant TTV), meeting the requirements for production of semiconductor devices of high-quality, which are composed of semiconductor wafers with integrated circuits built at high densities therein, or production of semiconductor wafers of large diameter.
The parallelism as required can be provided simply by controlling the flow rates of liquid. This facilitates the required inclination-controlling in such a stable fashion that semiconductor wafers of one and same quality can be provided.
When water is used in the liquid bearing, the stiffness of the bearing system is made large enough to assure that the parallelism of the wafer-gripping surfaces relative to the counter grindstones is maintained with good precision, and advantageously semiconductor wafers cannot be contaminated even if they are wet with water. | Disclosed is an improved semiconductor wafer grinding apparatus comprising at least wafer holding means and wafer grinding means. The wafer holding means comprises a holder having a wafer-gripping surface for sucking and holding a selected semiconductor wafer and liquid bearing means for rotatably supporting the holder. The liquid bearing means has inclination control means formed therein, and the inclination control means includes discrete inclination controlling areas for suspending the holder at upper and lower levels. Each inclination controlling area has flow rate control means connected thereto. The parallelism of the wafer-gripping surface relative to the wafer grinding means is assured by controlling the flow rate of the liquid to each inclination controlling area. | 1 |
RELATED APPLICATION
This application is related to copending application Ser. No. 08/560,727, filed Nov. 20, 1995, which is entitled "PENTACLETHRA MACROLOBA PROTEIN HAVING INSECTICIDAL PROPERTIES" whose teachings are incorporated herein by reference.
FIELD OF THE INVENTION
The invention relates to methods and materials for controlling insect species. In particular, the invention relates to a substance or mixture of substances extracted from the plant Pentaclethra macroloba, which substance or mixture of substances have leucine aminopeptidase inhibition activity and hemagglutinin activity, the latter being a characteristic of lectins, and has been found to exhibit insecticidal activity when applied at levels comparable to Bacillus thuringiensis protein endotoxin levels.
BACKGROUND OF THE INVENTION
Numerous insect species are serious pests to common agricultural crops such as corn, soybeans, peas and similar food and fiber crops. During the last century, the primary method of controlling such pests has been through the application of synthetic chemical insecticide compounds. However, as the use of such chemical compounds proliferated and continued, it became evident that such wide-spread use posed problems with regard to the environment, the non-selectivity of the compounds, increasing insect resistance to the chemicals and the effect of such compounds, after run-off, on higher order species such as fish and birds among others. As a result of such problems, other methods of controlling insect pests were sought and tried.
One such alternative method of pest control has been the use of biological organisms which are typically "natural predators" of the species sought to be controlled. Such predators may include other insects, fungi (milky-spore) and bacteria such as Bacillus thuringiensis. Alternatively, large colonies of an insect pest have been raised in captivity, sterilized and released into the environment in the hope that mating between the sterilized insects and fecund wild insects will decrease the insect population. While both these approaches have had some success, they entail considerable expense and present several major difficulties. For example, it is difficult both to apply biological organisms to large areas and to cause such living organisms to remain in the treated area or on the treated plant species for an extended time. Predator insects can migrate and fungi or bacteria can be washed off a plant or removed from a treated area by rain. Consequently, while the use of such biological controls has desirable characteristics and has met with some success, in practice these methods seem severely limited. However, scientific advances seem to offer new opportunities for controlling insect pests.
The advances in biotechnology in the last two decades have presented new opportunities for pest control through genetic engineering. In particular, advances in plant genetics coupled with the identification of insect growth factors and naturally-occurring plant defensive compounds or agents offer the opportunity to create transgenic crop plants capable of producing such defensive agents to thereby protect the plants against insect attack.
The resistance of plants to insect or parasite infection relies on a variety of structural and chemical defense mechanisms. These mechanisms can be pre-formed or can be activated upon parasite attack. The plant resistance created by these mechanisms can be limited to specific races of pathogens or can be effective against a broad spectrum of parasitic species. The biochemical and genetic characterization of such defense mechanisms and the chemical substances involved has led to the identification of plant gene sequences that may be used to genetically engineer plants expressing these mechanisms and chemicals.
Transgenic plants that are resistant to specific insect pests are known and have been transgenically created using genes encoding Bacillus thuringiensis (BT) endotoxins or plant protease inhibitors (PIs). The resistance of plants through the use of transgenically inserted BT genetic material encoding for BT toxins has been shown to be very effective and the first cultivars expressing this genetic material are now commercially available. Effective plant protection using transgenically inserted PI genetic material has not yet been demonstrated in the field. While cultivars expressing BT genetic material may presently exhibit resistance to pests, resistance based on the expression of a single gene might eventually be lost due to the evolution of BT resistance in the insect pests. Consequently, the search continues for additional genetic material which can be transgenically inserted into plants to provide them protection against insect pests.
Scientists have identified some specific plant components or compounds which act as defensive agents to protect a plant from attack by insect pests and pathogens. While such components are usually present at only low levels in various plant tissues, some of them are also capable of being induced to higher levels upon attack by an insect pest or a pathogen. Examples of such defensive compounds include alkaloids, terpenes and various proteins such as enzymes, enzyme inhibitors and lectins (14, 24, 27 and 28). Of particular interest are plant derived compounds which can block or alter normal biomolecular activity and thus inhibit insect growth or kill the insect. For example, trypsin is a digestive enzyme secreted by the midgut cells into the endo and exo peritropic space, and leucine aminopeptidase (LAP) is a digestive enzyme. The role of both in the body is to hydrolyze polypeptides into smaller units which can then be utilized by the host subject, for example, an insect. An enzyme such as trypsin which catalyzes the hydrolysis of peptide bonds is called a protease. Blocking trypsin activity will inhibit insect growth. A trypsin inhibitor (abbreviated TI) or leucine aminopeptidase inhibitor (herein abbreviated LAPI) is thus a compound which will block or decrease trypsin or leucine aminopeptidase protease activity, respectively. As a result of such blockage or decrease in trypsin or LAP protease activity, a host subject which has ingested TI or LAPI with its food will obtain liffle or no benefit from the polypeptides contained in the food. The host may thus fail to grow, mature and may indeed ultimately starve and die.
Plant lectins are group of proteins which may stimulate mitosis, a process which takes place in the nucleus of a dividing cell, involves a series of steps (prophase, metaphase, anaphase and telophase), and results in the formation of two new nuclei, each of which have the same number of chromosomes as the parent nucleus. The lectin molecule binds to specific receptors on the cell surface, possibly analogous to or identical to the receptor sites on the cell surface which normally bind certain hormones such as insulin (whose action lectins can mimic on some cells). Once the lectin is bound, a molecular signal is set off within the cell which greatly effects the rate of cell division and the tendency to differentiate.
One of the best known lectins is wheat phytohemagglutinin which is so named because it agglutinates red blood cells. Red blood cell agglutination is a rather general property of lectins. Introduction of a lectin into blood samples causes the red blood cells to cluster together. In a host such as an insect, this would effectively remove the cells from their role of transporting oxygen and/or cause blockage of the smaller arteries and veins, and effectively result in the insect's death. Agglutination reactions also serve as an analytical tool. Properly performed, agglutination reactions have a high degree of sensitivity and can detect an enormous variety of substances. Inhibition of agglutination is likewise important. If carefully standardized using highly purified substances, inhibition of agglutination can be used as an indicator of the amount of a substance, typically an antigen or antibody, in animal, including human, or plant tissue or cells. Agglutination and techniques: see D. P. Stites et al., Basic & Clinical Immunology, 6th Ed. (Appleton & Lange, Norwalk, Conn., 1987), pages 274-277.!
Aminopeptidases are proteases which remove the N-terminal amino acid of polypeptides. They are found in a wide variety of animals (12) and some plant species (8) at various locations in the subject such as the midgut in insects (4, 7) and mammalian kidneys, liver and lens (12). The aminopeptidases are classified according to the N-terminal amino acid the enzyme prefers and they commonly contain a divalent metal ion, usually Zn +2 . On the cellular scale, aminopeptidases have been found in the cytosol, various organelles and as components of the cellular membrane (12).
Aminopeptidases have been implicated in a variety of biological functions. For example, they are believed to enhance cell-mediated immunity (2), and to be involved in the regulation of hormones and the digestion of polypeptides (12) in food. They are also believed to play a role in some human diseases such as hypertension (3) and cancer (10). Especially important among aminopeptidases, at least from a digestive viewpoint, is leucine aminopeptidase (LAP), an exopeptidase which has a preference for leucine-terminated polypeptides or proteins as described by Taylor (12). LAP isolated from porcine liver has an estimated molecular weight of 318 kilodaltons (kDa) and is composed of at least six subunits of 35 kDa molecular weight.
The art has shown that there are, in microbes and animals, naturally occurring compounds which inhibit the activity of aminopeptidases. Two such aminopeptidase inhibitors, bestatin and amastatin, have been isolated from microbial sources such as Streptomyces sp. These two inhibitors are small peptides which have been shown to completely inhibit the activity of several aminopeptidases (13, 1). Synthetic aminopeptidase inhibitors such as aminophosphonates (6) and catechoyl-dipeptides (9) are also known. However, until the disclosure of the instant invention, the art has not previously known or shown that aminopeptidase inhibitors are present in and can be isolated from plants.
An ideal source of plant species to investigate for potential inhibitory substances is the tropical forests. The diversity of tropical forest plant and insect life provides an ideal evolutionary background for the development of inhibitory substances. For example, a given tropical plant species might be the subject of attack by a variety of insect species. Consequently, the plant may develop a particularly strong or effective inhibitory substance for use as a protective agent against such a diversity of insect life. Janzen et al. (19), studying trypsin inhibition and lectins, investigated seeds from 59 legumes from the tropical dry forest and showed that while all were capable of inhibiting bovine trypsin, they did so at different levels. Likewise, the presence and levels of lectins varied with seeds of different species. That is, some were stronger inhibitors than others. One such tropical plant not tested by Janzen was the legume Pentaclethra macroloba (hereinafter P. macroloba or Pm, (17)). Recently, Chun et al. (29) showed that aqueous seed extracts from P. macroloba had an inhibitory effect on insect herbivores.
The LAPI substance disclosed herein is believed to be the first aminopeptidase inhibitor isolated from a plant source. The results shown herein indicate that it effectively kills insects when administered at microbial Bacillus thuringiensis (BT) insecticidal protein levels. The LAPI substance described herein appears to be the most effective non-BT insecticidal protein ever isolated. The toxicity of the Pm derived toxin was retained in dialysis tubing and could be precipitated with ammonium sulfate. This suggests that the toxicity is caused by a protein, a proteinaceous substance or a mixture containing a proteinaceous substance rather than low molecular weight secondary metabolites. In addition, the Pm extracts were found to cause the agglutination of rabbit and human blood cells. No similarity to known agglutinins was found. The active substance(s) in the Pm extract are apparently comprised of a protein, a proteinaceous substance or an amino acid containing substance, an ethidium bromide binding substance, a fluorochrome of as yet unidentified nature, and sugars including glucose, rhamniose and arabinose.
The purpose of the present invention is to identify and characterize one or a plurality of substances which are not trypsin inhibitors and which are obtainable from P. macroloba, said substance(s) reducing insect growth, increasing insect mortality, agglutinating red blood cells and inhibiting leucine aminopeptidase activity.
It is a further purpose of the invention to provide a method for the separation and isolation of such substance(s) obtainable from P. macroloba and to demonstrate the inhibitory nature of such inhibitory substance.
It is a further purpose of the invention to identify an antinopeptidase inhibitor which has sufficient insect growth inhibitory effects to warrant the genetic sequence producing the inhibitor being transgenically inserted into a food crop gene where it will be expressed and will provide protection from one or a plurality of insect species including, but not limited to, European corn borer (Ostrinia nubilalis), Diabrotica species such as the Western, Southern and Northern corn rootworms, corn earworm (Helicoverpa zea), cowpea weevil (Callosobruchus maculatus) and similar insect pests known to those skilled in the art.
It is a further purpose of the invention to identify one or a plurality of substances which exhibit red blood cell agglutination activity.
It is a further purpose of the invention to identify one or a plurality of substances which have an inhibitory effect on digestive or regulatory enzymes, and in particular on the activity of leucine aminopeptidase.
SUMMARY OF THE INVENTION
The invention identifies and provides one or a plurality of substance(s) obtainable from Pentaclethra macroloba which have a molecular weight in the range 1.5 to 60 kilodaltons (kDa) in size; said substance being designated herein as either LAPI or Pentin-2.
The invention is also directed to one or a plurality of purified insecticidal substance(s) obtained from Pentaclethra macroloba by a method comprising the steps of extracting sliced, crushed or powdered Pentaclethra macroloba seeds, extracting said sliced, crushed or powdered seeds with an aqueous solution to obtain a crude extract having one or a plurality of substance(s) which increase insect mortality, inhibit leucine aminopeptidase activity, have lectin hemagglutinin characteristics and a molecular weight in the range 1.5 to 60 kDa; said substance or plurality of substances comprising protein or amino acid containing material, an ethidium bromide binding substance, an unknown fluorochrome and various sugars.
The invention is further directed to a process for protecting plants against insect attack by European corn borer, Helicoverpa zea, corn rootworms and similar insects by exposing said insects to an insecticidal substance obtained from P. macroloba, said insecticidal substance being a non-trypsin affecting substance contained within a crude or purified extract of P. macroloba seed and identified as having one or a plurality of active components whose molecular weights are in the range 1.5-60 kDa. The insecticidal substance of the invention may be topically or systemically applied to a plant using methods and means known to those skilled in the art. The insecticidal substance of the invention may be produced by a plant into which has been inserted genetic material encoding the P. macroloba insecticidal substance disclosed herein.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a hydrophobic interaction chromatograph of a P. macroloba extract obtained using a phenyl Sepharose coluim and indicates with an arrow the position of the peak containing the substance(s) having agglutination and LAPI activity, and capable of increasing insect mortality.
FIG. 2 illustrates the gel filtration of the active substance(s) obtained as shown in FIG. 1, the active component being shown in FIG. 2 as the shoulder and peak indicated by the arrow.
FIG. 3 illustrates the reverse phase high pressure liquid chromatograph (HPLC) of the peak and shoulder substance(s) illustrated in FIG. 2, the active material being indicated by the arrows.
FIG. 4 illustrates the wavelength scan of a preparative SDS-PAGE fraction which eluted after the bromophenol blue marker dye.
FIG. 5 generally illustrates the ethidium bromide binding fluorescence of the active substance(s) of the invention on an ethidium bromide stained gel; FIG. 5A showing ethidium bromide binding fluorescent material collected after hydrophobic interaction chromatography and FIG. 5B showing ethidium bromide binding fluorescent material after gel filtration.
FIG. 6 illustrates the inhibition of 10 μg porcine kidney leucine aminopeptidase by different quantities of the active substance(s) of the invention collected after purification and separations using isoelectric focusing and hydrophobic interaction chromatography.
FIG. 7 graphically illustrates the toxicity of the active substance(s) obtained from P. macroloba to European corn borer larvae after seven days. "Crude" signifies extract after removal of particulate matter with or without trypsin affinity chromatography to remove trypsin inhibitors. "HIC" signifies extract obtained after hydrophobic interaction chromatography. "PAG" signifies extract obtained after preparative, non-denaturing acrylamide gel electrophoresis.
FIG. 8 illustrates insect mortality resulting from the application of the various fractions separated on a Superose 12 column as described in Example 1.
FIG. 9 illustrates the inhibition of insect growth resulting from the application of the various fractions separated on a Superose 12 column as described in Example 1.
DETAILED DESCRIPTION OF THE INVENTION
References
The teachings of the following publications, which are known to those skilled in the art of the field of the invention, are incorporated herein by reference.
1. T. Aoyagi et al., J Antibiotics 31: 636-638 (1978); amastatin, an aminopeptide inhibitor.
2. R. K. Barclay et al., Biochem Biophys Res. Commun., 96: 1732-1738(1980); inhibition of enkephalin-degrading aminopeptidase activity by selected peptides.
3. O. A. Carretero et al., Hypertension 68: 366-371 (1991); the use of metallopeptidase inhibitors for treating hypertension.
4. J. G. Houseman et al., Insect Biochem. 17: 213-218 (1987); a preliminary characterization of the digestive proteases in the posterior midgut of the stable fly Stomoxys calcitrans (Diptera: muscidae).
5. C. A. Lee et al., Anal. Biochem. 166: 308-312 (1987); copper staining used in sodium dodecyl sulfate--polyacrylamide gels.
6. B. P. Lejczak et al., Biochem. 28: 3549-3555 (1989); inhibition of aminopeptides by aminophosphonates.
7. C. J. Lenz-Goodman et al., Archives Insect Biochem. Physiol. 16: 201-212 (1991); the digestive proteases of the larvae of corn earworm, Heliothis zea: characterization, distribution and dietary relationships.
8. L. Mikola and J. Mikola, Plant Proteolytic Enzymes, ed. M. J. Dalling, (CRC Press, Boca Raton, Florida 1986 ), Vol. 1, pages 97-117.
9. L. J. Nakonieczna et al., Z. Naturforsch. 44b: 811-816 (1989); catechoyl-dipeptides as leucine aminopeptidase inhibitors.
10. K. Ota, Biomed Pharmacol. 45: 55-60 (1991), a review of bestatin clinical research.
11. H. Schagger et al, Anal. Biochem. 166: 368-379 (1987); describes the use of tricine-SDS-PAGE to separate proteins in the 1-100 kDA range.
12. A. Taylor, FASEB, J 7: 290-298 (1993), describing the structure and function of aminopeptidases.
13. H. T. Umezawa et al., J Antibiotics 29: 97-99 (1976), bestatin, an aminopeptidase inhibitor.
14. L. T. Baldwin, Oecologia 75: 367-370 (1990).
15. J. T Christeller et al., Insect Biochem. 19: 233-241 (1989).
16. B. C. Hammer et al., Phytochemistry 28: 3019-3026 (1989).
17. G. S. Hartshorn in Costa Rica Natural History, Janzen Ed. (Univ. Chicago Press, Chicago 1983), pages 301-303.
18. V. A. Hilder et al., Nature 330: 160-163 (1987).
19. D. H. Janzen et al., J Chem. Ecol. 12: 1469-1480 (1986).
20. R. Johnson et al., Proc. Natl. Acad. Sci. 86:9871-9875 (1989).
21. U. K. Laemmli, Nature 227: 680-685 (1970).
22. G. Pearce et al., Plant Physiol. 102: 639-644 (1993).
23. H. Rathburn et al., J Econo. Ento. Submitted (1996).
24. C. A. Ryan, Ann. Rev. of Phytopathol. 28: 425-449 (1990).
25. Ureil et al., Nature 218: 578-580 (1968).
26. T. H. Czapla and B. A. Lang, J Econo Ento. 83 (6): 2480-2485 (1990).
27. M. J. Chrispeel et al., Plant Cell 3: 1-9 (1991).
28. D. H. Janzen et al., Phytochemistry 16: 223-227 (1977).
29. J. Chun et al., J Econo Ento. 87: 1754-1760 (1990).
Terminology and Abbreviations
1. TI=trypsin inhibitor.
2. pI=the pH of a solution containing a molecule at which there is no charge on that molecule.
3. IEF=Isoelectric focusing.
4. SDS-PAGE=Sodium dodecyl sulfate-Polyacrylamide gel electrophoresis.
5. NaOAc=sodium acetate.
6. Tris-Cl 32 Trizma base molecular biology reagent.
7. LAP=leucine aminopeptidase.
8. LAPI=leucine aminopeptidase inhibitor of the invention.
9. BT--Bacillus thuringiensis.
10. Pentin-2 =the leucine aminopeptidase inhibitor which exhibits agglutination activity and increases insect mortality as disclosed herein.
While various procedures may be used to separate and isolate the active substances comprising the invention, the examples given herein describe the preferred procedures for so doing. Additional methods, all of which use the crude P. macroloba extracts, include a combination of ion exchange chromatography, dialysis and other techniques. P. macroloba seeds were collected from the lowland tropical plain forest of Costa Rica and transported to the inventors'laboratories where they were sliced, lyophilized and stored at -20° C. prior to use.
Those skilled in the art, while observing that the claimed invention may be suitable for encoding into the genetic code of plants, will also recognize that the active substance(s) of the invention can be formulated for topical or systemic application to plants in order to afford such plants insect protection.
EXAMPLE 1.
Active fractions from Pentaclethra macroloba were purified using bioassay-directed and biochemically-directed approaches. Initially, crude and dialyzed extracts of Pentaclethra macroloba were tested for their effects on neonate ECB larvae. Seeds of P. macroloba were homogenized in cold 10 mM sodium phosphate buffer, pH 7.5. Insoluble polyvinylpyrrolidone was added to the extract to help remove phenolic compounds. The extracts were either filtered through Miracloth and centrifuged to remove debris and other insoluble materials, or simply centrifuged. The supernatant fluid was filtered to remove lipids and other materials which did not pellet during centrifugation. The crude extract was dialyzed extensively against 10 mM sodium phosphate buffer, pH 7.5, at 4° C. over a period of two to four days. During this time, additional proteins and other materials precipitated. These insoluble materials were removed by centrifugation at 18,000 rpm in a Sorvall SS34 rotor at 4° C. prior to use of the material for ECB bioassays. Both crude extracts and dialyzed extracts caused reduction in insect growth and development, and increased insect mortality when incorporated into an artificial diet or overlaid on the diet upon which the ECB larvae were reared. The activity was moderately heat stable.
The active components present in P. macroloba seed extracts were fractionated and purified by conventional methods of protein purification. In some instances, dialyzed extracts were heated prior to further fractionation to remove some proteins. Extracts were heated in a water bath at 70° to 100° C. for one to five minutes. After heating, the extract was cooled rapidly on ice and centrifuged at 18,000 rpm in a Sorvall SS34 rotor at 4° C. to remove denatured proteins. Proteins present in the heated and/or dialyzed extracts were concentrated either by ammonium sulfate precipitation or by centrifugal concentration in Centricon filters. For ammonium sulfate precipitation, solid enzyme grade ammonium sulfate was ground to a fine powder with a mortar and pestle. The ammonium sulfate was added very slowly to the extract and stirred with a magnetic stirrer. The extract was maintained in an ice bath at all times. The ammonium sulfate was added to a final concentration of 0.6 g ammonium sulfate per ml of extract. After all of the ammonium sulfate was added, the extract was kept on ice for 15-30 minutes to allow the proteins to precipitate. At this time, the precipitated proteins and other materials were collected by centinfugation at 18,000 rpm in a Sorvall SS34 rotor at 4° C. The pellet was resuspended in a minimal amount of 10 mM sodium phosphate buffer, pH 7.5. Extracts were concentrated in Centricon filtration devices according to the manufacturer's instructions.
The concentrated proteins and associated materials were applied to a size exclusion column packed with either Sephacryl 200 or Superose 12, Prep grade. The volume of the packed columns were approximately 100 ml. The column was equilibrated with about five volumes of 10 mM sodium phosphate buffer, pH 7.5. Sample was applied in a volume of 0.5 to 1 ml. Proteins and other constituents were eluted with 10 mM sodium phosphate buffer, pH 7.5. Twenty fractions were collected and tested for their effects on ECB larvae. Protein concentrations were estimated using the Bradford assay. Results of ECB bioassay from a typical fractionation of P. macroloba seed extracts are shown in FIGS. 8 and 9. Several fractions caused very high mortalities (FIG. 8) and prevented growth of the neonate larvae (FIG. 9). The active component was designated Pentin 2.
Extracts were also fractionated by anion-exchange chromatography on Pharmacia Q Sepharose Fast Flow as the media and using standard methods known to those skilled in the art. A 10-ml column was packed with Q Sepharose and washed extensively in low-salt and high salt buffers. In general, 25 mM Tris-HCl buffer was used as the primary chromatography buffer in the pH range from 8.0 to 9.0, although other buffers were used for chromatography at other pH's. The following is an example of the normal methods used for ion-exchange chromatography.
The column was equilibrated with 25 mM Tris-HCl buffer, pH 8.0. Sample was dialyzed at 4° C. into 25 mM Tris-HCl buffer, pH 8.0, with several buffer exchanges. Sample was applied to the column and all fractions from the column were collected. After all the sample was on the column, the column was washed with 25 mM Tris-HCl buffer, pH 8.0 until most of the unbound protein was washed from the column. Proteins bound to the column were eluted with a linear or step gradient of sodium chloride in 25 mM Tris-HCl buffer, pH 8.0. Fractions were collected and tested for their effects on ECB larvae. Protein concentrations were estimated using the Bradford assay. Results of fractionation by anion-exchange chromatography are not shown.
Fractions from size-exclusion chromatography were subjected to analysis on 12% SDS polyacrylamide gels. Fractions from ion-exchange chromatography were first dialyzed into 10 mM Tris-HCl, pH 8.0 to remove salts and then subjected to SDS-PAGE. Gels were either stained with Coomassie Blue R250 using standard protocols or silver stained. Fractions demonstrating activity against ECB larvae contained only one or two faint protein bands. The native molecular weight of the active material was estimated by size-exclusion chromatography. Based on this analysis, the active component had a molecular weight in the range of 40-60,000 Daltons. Seed extracts were also fractionated based on the ability to inhibit leucine aminopeptidase and to agglutinate red blood cells.
FIGS. 8 and 9 illustrate the effects of highly purified Pentin 2 on the growth and survival of ECB larvae. Pentin 2 was extensively purified as described on a Superose 12 column. Fractions were collected and a 100 μl sample from each fraction applied to the surface of the diet in each well and allowed to dry. Two neonate larvae were placed on the diet in each well and 8 wells were used per treatment. The weight of the larvae and mortality were recorded after 7-10 days. Several fractions showed increased insect mortality, the highest mortalities being shown by factions 3-7.
EXAMPLE 2.
This example and Example 3 were directed to determining the leucine aminopeptidase and agglutination activities of the substance of Example 1, and to show that the same substance is responsible for all three effects. Seed extract was prepared as described by Rathburn et al. (23) with and without heating as noted herein. Heating was accomplished by boiling sliced seeds in 0.1 M Tris-Cl, pH 8.5, 5 mM MgCl 2 before homogenization. Briefly, the seeds were homogenized in buffer with polyvinylpyrrolidone. The extract was filtered and centrifuged. The supernatant fluid was heated at 70° C. and subjected to trypsin affinity chromatography (TAC) to remove trypsin inhibitors. The resulting eluant was lyophilized, resuspended in distilled water and dialyzed using a 3,500 molecular weight cut-off (MWCO) membrane against 10 mM NaCl to remove low molecular weight metabolites. TAC was performed according to the method of Rathburn (23). Absorbance at 280 nm (nanometers) was used to follow the elution of the bound proteins.
A sample of the dialyzed material containing 40 mg of protein was separated into components by preparative isoelectric focusing (IEF) using the Rotofor system (Bio-Rad). The Rotofor separates molecules on the basis of their pI or isoelectric point. Every molecule will have a specific net charge, either positive, negative or zero, at a specific pH. The Rotofor, using an electrical current, moves molecules through a pH gradient until they reach their pI; i.e., the pH at which they have zero net charge. The molecule stops migrating at its pI because it is no longer affected by the electrical current. The focusing chamber of the Rotofor is separated into twenty (20) smaller chambers by permeable membranes. These twenty samples are removed simultaneously to ensure as little mixing as possible.
The sample was placed in the focusing medium, a buffered solution (see manufacturer's instructions) which included 12.5% (w/v) glycerol and 2.5% of pH 3-10 Ampholytes (Bio-Rad). After focusing, the fractions were collected, the pH of each determined and each fraction was then dialyzed against 1 M NaCl using a 3,500 MWCO membrane to remove the Ampholytes. The samples were then dialyzed against deionized water to remove the NaCl. Each fraction was lyophilized, resuspended in 0.4 ml of 10 mM NaCl. Fifteen microliters of each fraction was then analyzed using denaturing 12-20% gradient SDS-PAGE (for estimating molecular weight and determining purity) and tested for LAP inhibition and agglutination activity. Most of the agglutination activity and LAP inhibition were found in the acidic fractions. Those fractions with the strongest agglutination activity were also found to be most effective in causing ECB mortality in the bioassays. Fractions that showed LAP inhibition were pooled and further purified by the addition of ammonium sulfate to 75% saturation. The ammonium sulfate preparation was then centrifuged at 10,000 g and 4° C. for 10 minutes. The supernatant liquid was first dialyzed against 10 mM NaCl and then subjected to ion exchange chromatography.
Ion exchange chromatography was used to separate inhibitors from other fractions. A 1.5 ×5.0 cm column containing Q5 Sepharose (Pharmacia) was prepared and equilibrated using 25 mM Tris-Cl, pH 8.0. The column was eluted using a linear gradient of 0 to 0.15 M NaCl. Five milliliter fractions were collected at a flow rate of 1.5 ml/min, the elution being monitored at 280 nm, and the fractions tested for LAP inhibition. Fractions that showed inhibition were pooled, dialyzed against deionized water, lyophilized, dissolved in PBS buffer, pH 8.0, and subjected to gel filtration chromatography to separate the inhibitors from other fractions based on their size. The molecular weight, estimated by gel filtration chromatography, was 45-55,000 Daltons.
Proteins were assayed using the bicinchoninic acid (BCA) system (Pierce. Ref. 22). Bovine serum albumin was used as the standard.
SDS-PAGE, using Rotofor fractions which exhibited inhibitory activity, was used to separate components and determine their subunit molecular weights. The procedure was carried out according to the method of Laemmli (21) using two types of gel, a 12 or 15% acrylamide gel or a 10-20% gradient acrylamide gel. Protein samples were denatured by boiling for three minutes in SDS buffer (BioRad) with 3 mM 2-mercaptoethanol prior to their placement on the gel. For analysis of polypeptides with a molecular weight less than 10 kDa, the discontinuous method of Schagger et al. (11) was employed. After electrophoresis, the proteins were detected by staining with Coomassie Brilliant Blue 250 (12), silver staining or reverse copper staining (5). A band which corresponds with the activity was detected on an SDS-PAGE gel stained with copper. The subunit molecular weight of the substances which exhibit LAP inhibition activity, agglutination, and ECB mortality effects as described and claimed herein was deterrnined by SDS-PAGE to be the range 1.5-10 kDa.
It was noted that different procedures seemingly give different molecular weights. However, it is here noted that the active substance described herein seems capable of forming a complex, conjugate, adduct or a multimeric species with itself or with another substance, presumably proteins or proteinaceous material and sugars, which may be present in a Pm extract. These multimers, conjugates, etc., when characterized by molecular weight determining methods and some separatory techniques, may separate or appear as species having molecular weights over 10 kDa or under 10 kDa. However, all such multimers, conjugates, etc., exhibit insecticidal properties. Consequently, for some applications such a topical spraying, it may not be necessary to use the "purified` insecticidal substance. One may use a crude extract or other preparation which contains such complex, conjugate, adduct, multimer, or similar species.
The above observation explains why one finds that gel filtration or size exclusion chromatography indicates a molecular weight in the range 40-60 kDa and SDS-PAGE gives results in the range 1.5-10 kDa. The 40-60 kDa species may be a multimeric species comprising many units of the active component and possibly other components such as, for example, sugars.
Leucine aminopeptidase inhibition was assayed using two units of porcine kidney LAP (cytosol, type III-CP, EC 3.4.11.1) containing 0.1 M Tris-Cl, 5 mM MgCl 2 , pH 9.5, at 25° C. in a final volume of 1 ml. The reaction was initiated by the addition of 27 μl of 40 mg/ml L-leucine p-nitroanilide dissolved in dimethyl sulfoxide (DMSO). The increase in absorbance at A 410 was followed for five minutes. To measure inhibition, an aliquot of the Pm-derived LAP inhibitor was added to the porcine kidney LAP preparation prior to the addition of the substrate. The volume of the buffer was adjusted accordingly. Percent inhibition was determined as described by Rathbun et al. (23).
Normally, the inhibition of a protease by an inhibitor exhibits a linear relationship and the effectiveness of an inhibitor is measured by the amount required to achieve 50% inhibition. The crude LAP inhibitor which was isolated from Pentaclethra macroloba seeds behaved quite differently. The LAPI extract obtained from P. macroloba inhibited porcine LAP linearly until about 35% inhibition whereupon the percent inhibition relative to increasing amounts of inhibitor began to plateau. To achieve 50% inhibition would have required very large amounts of crude inhibitor and would not have been a realistic expression of inhibition. Consequently, 20% inhibition, approximately the midpoint of the linear portion of a percent inhibition curve, was chosen to express the effectiveness of inhibition during the early steps of purification. Highly purified LAPI inhibited LAP activity as shown in FIG. 6.
Table 1 gives the LAP inhibition results which were obtained using the twenty Rotofor LAPI fractions obtained in a single Rotofor separation. The results, which are repeatable over numerous tests, indicate the LAPI protein is focused in the acidic region and concentrated mainly in Fractions 1-5. Fraction 1 always yields the largest amount of protein and consequently has the greatest amount of activity per Rotofor unit volume. The results indicate that the P. macroloba LAP inhibitor has pI equal to approximately 3.
TABLE 1______________________________________Rotofor Fractions, Their pH, % LAP Inhibitionand Relative AgglutinationRotofor % LAP RelativeFraction pH μg protein Inhibition Agglutination______________________________________ 1 3.21 1375 54.5 + 2 3.65 985 48.0 ++ 3 4.18 930 46.8 +++ 4 4.56 755 43.4 +++ 5 4.93 660 38.7 ++ 6 5.37 385 11.1 ++ 7 5.73 375 8.4 ++ 8 6.05 355 4.1 + 9 6.37 350 3.8 +10 6.69 375 2.2 011 6.95 400 0 012 7.23 425 0 013 7.45 490 0 014 7.87 620 0 015 8.12 595 0 016 8.32 755 0 017 8.7 750 0 018 9.27 880 0 019 9.81 1135 0 020 10.85 885 0 0______________________________________
EXAMPLE 3.
In this Example, the analysis of P. macroloba seed extract was pursued from two different aspects. The first was from the point of isolating and identifying the substance(s) responsible for agglutination activity. The second was from the point of isolating and identifying the substance(s) responsible for leucine aminopeptidase activity. The results set forth herein indicate that the same substance(s) are responsible for both agglutination and leucine aminopeptidase inhibition, and for Ostrina nubilalis (ECB) mortality in the bioassays.
A. Purification of the Agglutinating Substance(s)
Crude extracts of P. macroloba seed were obtained as described above. The extract was separated into fractions using the Rotofor device. The Rotofor fractions were dialyzed and tested for agglutination and ECB mortality. Agglutination and ECB mortality activity were found in the acidic fractions.
Protein assays and SDS-PAGE results indicated that most of the protein contained in the P. macroloba extracts focused in the basic Rotofor fractions. When tested or assayed, the basic fractions exhibited little or no agglutination as shown in Example 2, Table 1 and also did not cause significant insect mortality (results not shown).
Rotofor fractions exhibiting agglutination activity were further separated by hydrophobic interaction chromatography using a phenyl Sepharose column and 25 mM sodium phosphate buffer, pH 7. Proteins were eluted with a gradient from 0-6.0 M guanidine hydrochloride in 25 mM sodium phosphate, pH 7.0. Most of the material having agglutination activity eluted late in the guanidine hydrochloride gradient as shown in FIG. 1. Agglutination and insect mortality activity were found in the same fractions.
Active fractions after hydrophobic interaction chromatography were pooled, dialyzed, concentrated by lyophilization, and loaded onto a Sepharose 12 gel filtration column. Proteins were eluted with 25 mM sodium phosphate, pH 7.0, containing 150 mM NaCl. The separation was monitored at 280 nm as shown in Fig. 2. Only one major peak, which has a leading shoulder, was eluted from the Sepharose 12 column, suggesting that most of the impurities in the sample were removed during the previous separation steps. Agglutination, insect mortality and leucine aminopeptidase inhibition activity was concentrated in the material of the major peak and shoulder shown in FIG. 2.
The material in the major peak and shoulder of FIG. 2 was dialyzed, concentrated by lyophilization and subjected to reverse phase chromatography, the results of which are shown in FIG. 3. Disregarding the broad injection peak between about 0-4 min, the reverse phase HPLC shows two major peaks (arrows) which were determined to contain the active agglutinin, LAPI and insect mortality substance(s). However, the activity was at a reduced level compared to the active gel filtration and hydrophobic interaction chromatography fractions described above.
While it was possible, using the chromatograms described above, to isolate and identify substances having agglutination, insect mortality and LAPI activity, attempts to identify these substances using silver or Coomassie Blue stained SDS-PAGE or non-denaturing acrylamide gels were not successful. However, it was noted that on the SDS-PAGE gels, a diffuse clear zone was found close to the position of the bromophenol blue tracking dye in the lanes containing material from Rotofor fractions after the material had been chromatographed and negative Cu ++ stained. When material from the reverse phase chromatograph of FIG. 3 was likewise subjected to SDS-PAGE, one broad band was found after the bromophenol blue tracking dye. These two sets of results indicate that the active material is of low subunit molecular weight, on the order of 1.5-10 kDa.
In order to obtain larger quantities of the above substance(s), those Rotofor fractions which contain the active material were further purified using preparative tube SDS-PAGE gels. The active material, which eluted immediately after the bromophenol blue marker, was collected in dialysis bags and was analyzed by UV spectrophotometry. The spectrophotometry results, FIG. 4, shows two absorbance maxima at 256 and 280 nm, suggesting that the eluant might contain nucleic acid in addition to protein.
On the basis of the spectrophotometry results, fractions containing active material which had been subjected to hydrophobic interaction chromatography and gel filtration chromatography were loaded onto agarose gels containing ethidium bromide (EtBr) and subjected to electrophoresis. Under ultraviolet illumination, a fluorescent zone appeared only in lanes which contained agglutinating material as shown in FIG. 5A. Similar results were obtained using Rotofor fractions, ion-exchange chromatography fractions and reverse phase HPLC fractions which were subjected to electrophoresis on agarose gels stained with EtBr. When Rotofor fractions with agglutination activity were loaded onto non-denaturing acrylamide gels, a large fluorescing zone appeared close to the bromophenol blue dye front after staining with EtBr as shown in FIG. 5B.
In order to verify that the EtBr stainable material was indeed the active substance or substances in the various fractions, preparative scale agarose gels and non-denaturing acrylamide tube gels were used to obtain quantities of the material. The material was then tested for agglutination activity and insect mortality. This procedure was facilitated by the weak fluorescence of the material which made it possible to omit staining of the preparative gels with EtBr. Both agglutination activity and insect mortality were found in the fluorescent bands which were collected in both separations. Similar results were obtained when material prepared by agarose gel electrophoresis or non-denaturing acrylamide tube gels was analyzed by reverse phase HPLC. Both peaks bound EtBr and exhibited agglutination activity and insect mortality. No agglutination activity or insect mortality was found in any non-fluorescent material.
The HPLC fractions shown in FIG. 3 were further analyzed and it was determined that the second peak could be converted into the first peak upon rechromatography. Based on results obtained after rechromatography, it appears that the second peak contains the unknown substance which absorbs more strongly at 280 nm and is carried along or conjugated or complexed to the material of the first peak.
B. inhibition of Leucine Aminopeptidase
P. macroloba seeds were ground and extracted as described above. In some cases, trypsin inhibitors were removed as described above. Extract was fractionated using the Rotofor apparatus and the fractions tested for the inhibition of digestive enzymes. The acidic fractions from the Rotofor separation were found to inhibit leucine aminopeptidase activity. Using the various separation techniques described above, it was determined that the same substances or substances which affected agglutination and insect mortality would also inhibit leucine aminopeptidase activity. FIG. 6 illustrates the inhibition of 10 μg of porcine aminopeptidase by increasing amounts of the active substance prepared by hydrophobic interaction chromatography. It was determined that 10-50 μg of protein was sufficient to cause 50% LAP inhibition. Similar results were obtained for material purified by preparative electrophoresis or gel filtration.
Biological Assays
Neonate Ostrina nubilalis (European corn borer, ECB) larvae were reared on artificial diets containing the leucine aminopeptidase inhibitor (LAPI) obtained from P. macroloba as described herein. The LAPI substance(s) may be used as either crude extract or purified as taught herein. The LAPI was either topically applied to the diet surface or incorporated into the diet as taught by Czapla and Lang (26). The culture tray used in the bioassays was divided into treatment groups. One or a plurality of LAPI preparations or fractions from the various separations were screened in each tray, each preparation or fraction being applied to a plurality of cells. Each cell was infested with one or two neonate larvae. A Mylar film with ventilation holes was affixed to the top of each tray to prevent escape and provide air.
For the topical (overlay) assays, a solution containing different concentrations of LAPI was prepared in 0. 1 M phosphate buffered saline (PBS), pH 7.8. Seventy-five microliters of LAPI in buffer solution were pipetted onto the surface of the Stoneville diet medium in each cell. The culture tray was rotated to ensure equal distribution of the inhibitor solution on the diet medium. Neonates were placed on the diet and the cells were sealed as described above. The control was 75 μl of 0.1 M PBS, only, per cell.
For the diet incorporation assays, Stoneville medium was prepared in standard fashion, but with only 90% of the prescribed water. LAPI was added such that the amount in the diet was in the range of 1-5 μg protein per milliliter diet. The control treatment consisted of 0.9 ml PBS buffer added to 8.1 g of medium. The medium was poured into the cells and the cells were then infested and covered as described above. Insect weights (Weight or Avg. Wt.) were determined 7-10 days after placing the neonates on the diet. The results of the assays are given in the tables.
Table 2 gives the results of the LAPI substance(s) on European corn borer larvae in topical assays. The percent mortality was determined at the end of a standard 7-day assay. The relative agglutination results were obtained using rabbit blood and standard agglutination procedures. The designation Rotofor/Q5 # X-Y indicates that the sample being used was Rotofor fractions 1-5 (see Table 1) which were subsequently chromatographed on a Sepharose Q5 column using standard techniques and isolated as fractions No. X to Y. The agglutination symbols +++ and ++ signify increasing agglutination titres, respectively. The results clearly indicate that the substance(s) responsible for leucine aminopeptidase inhibition is also responsible for insect mortality and agglutination activity.
TABLE 2______________________________________Effects of P. macroloba Substances on ECB Larval MortalityUsing an Overlay Assay. Diet Cell Protein % RelativeFractions Protein (μg/ml) (μg/ml) Mortality Agglutination______________________________________Prep 1A 26.1 2.6 100 ++B 19.4 1.9 100 +++C 14.3 1.4 100 ++Prep 2A 30.9 3.1 100 +++B 21.7 2.2 100 +++C 15.8 1.6 100 ++Prep 3A 51.7 5.1 100 +++B 19.0 1.9 69 ++______________________________________Notes:Prep 1: A = Rotofor/Q5 Sepharose, fractions 9-11. B = Rotofor/Q5 Sepharose, fractions 12-14. C = Rotofor/Q5 Sepharose, fractions 15-18.Prep 2: A = Rotofor/Q5 Sepharose, fractions 7-11. B = Rotofor/Q5 Sepharose, fractions 12-14. C = Rotofor/Q5 Sepharose, fractions 15-18.Prep 3: A = Rotofor/Q5 19-22/Superose, 12 fraction 12 B = Rotofor/Q5/Superose, 12 fraction 13.
FIG. 7 graphically illustrates the toxicity of the active substance(s) extracted from P. macroloba to European corn borer larvae. Crude extract is material which has particulate matter removed. HIC signifies extract which has been purified through hydrophobic interaction chromatography as described herein. PAG material that has been purified using preparative, non-denaturing acrylamide gel electrophoresis as described herein. Toxicity tests were performed using material topically applied to diet as described herein.
The results indicate that the agglutinating, leucine aminopeptidase inhibiting material obtained from P. macroloba is highly toxic to ECB. The toxicity is comparable to that of B. thuringiensis.
Amino Acid Analyses
Table 3 gives the amino acid analysis of the substance disclosed herein which exhibits agglutination activity, ECB toxicity and leucine aminopeptidase inhibition. Column A represents the calculated amino acid values obtained in one early analysis. Columns B, C, D and E represent four additional preparations which were analyzed, and the amino acid values for these analyses are reported as integers for simplicity. The analytical results for B, C, D and E were averaged to reduce error. The averaged results are shown in the Average column (Avg). The active material represented by the indicated peaks of FIG. 3 were analyzed. In all analyses, the most abundant residues were glycine, serine, alanine, threonine, aspartic acid and glutamic acid. All analyses indicated the absence of or low levels of cysteine, methionine, tryptophan, hydroxyproline and hydroxylysine residues. On the basis of all the analytical results, including the amino acid analyses, the active substance(s) obtained from P. macroloba appear to comprise a component which is fluorescent and binds EtBr, a low molecular weight protein or proteinaceous component which has the indicated amino acid analysis, and sugars.
Table 4 gives multiple amino acid analyses representing repeat separations of the substance disclosed herein which exhibits agglutination activity, ECB toxicity and leucine aminopeptidase activity after treatment in solution with HF (hydrofluoric acid) at 0° C., by methods known in the art, to remove carbohydrates. These analyses, although indicating a greater number of amino acids than the data in Table 3, are nonetheless consistent with Table 3 and serve to indicate that the active substance derived from P. macroloba is capable of forming multimers and/or adducts with other substances such as proteinaceous substances, carbohydrates and sugars which may be present with the active substance. The fact that these multimers or adducts persist through various separatory and analytical procedures indicates that they are of at least moderate strength and stability, and further indicates and explains why active substances of different molecular weight may have insecticidal properties as is indicated herein.
Treating the active substance with NaOH, nucleases or proteases did not destroy the fluorescence of EtBr stained gels. However, NaOH and protease treatment did lead to a change in mobility. Treatment with chlostripan argC-protease did not change the retention time on reverse phase HPLC.
Extracting active fractions separated by gel filtration chromatography, anion exchange chromatography or preparative Rotofor fractions with phenol and chloroform resulted in the loss of most of the fluorescence in the aqueous layer. A faint residual fluorescence remained which could be due to residual material or some substance derived from the original fluorescent substance.
TABLE 3______________________________________Amino Acid Analysis of Pentin-2 A B* C* D* E* Avg.______________________________________Aspartate 2.13 2 3 3 4 3Threonine 4.09 4 4 2 2 3Serine 5.18 5 5 4 4 4.5Glutamic 4.27 4 4 3 4 3.75Glycine 9.23 9 7 6 4 6.5Alanine 3.32 3 4 4 4 3.5Valine 1.85 2 2 2 3 2.25Methionine 0 0 0 0 0 0Isoleucine 0.97 1 1 1 2 1.25Leucine 1.33 1 2 2 3 2Tyrosine 0 1 1 1 0.75Phenylalanine 0 2 1 2 1.25Lysine 5.59 5 8 5 3 5.25Histidine 0 1 1 1 0.75Arginine 3.08 3 2 2 2 2.25Proline 2.25 0.625Total 39 46 36 41.5 40.625Residues______________________________________ Note: = Early detailed analysis of Pentin2. * = Analyses for different preparations of Pentin2. Avg. = average number of amino acids in B, C, D, and E.
TABLE 4______________________________________Amino Acid Analysis of Carbohydrate-Free Pentin-2 F G H I J Avg.______________________________________Aspartate 4 5 5 5 5 4.8Threonine 2 5 2 3 2 2.8Serine 9 5 4 6 8 6.4Glutamic 4 6 6 6 9 6.2Glycine 25 16 15 17 11 18.8Alanine 6 5 6 6 4 5.2Valine 3 3 3 4 3 3.2Methionine 1 0 0 0 0 0.2Isoleucine 1 1 1 2 2 1.4Leucine 1 2 3 3 3 2.4Tyrosine 1 0 1 1 2 1Phenylalanine 1 0 1 1 2 1Lysine 2 4 4 4 4 3.6Histidine 0 0 0 0 0 0Arginine 1 2 3 3 3 2.4Proline 0 3 5 0 3 2.2Cysteine 1 2 0 0 0 0.6Total 62 59 59 61 615 60.4Residues______________________________________ Note: The amino acid analyses F-J of Table 4 were carried out using material which had been treated, by methods known in the art, with HF to remove carbohydrates. Avg. = average number of amino acids in F through J.
During amino acid analysis, a ninhydrin positive, unidentified component was detected. This component appears to be relatively abundant. This component does not correspond to any of the unusual amino acids such as hydroxyproline. Based on its peak, it is more abundant than the most abundant amino acid present in the analyses given above. The fact that it is ninhydrin positive suggests that it is an amino acid or an amino acid derivative.
It is also noted that an amino acid analysis gives a ratio of the various amino acids present in a substance. In the actual substance, the amino acids may actually be present as some multiple of that ratio. This fact also helps to explain why by some techniques the molecular weight may appear to be in the range 1.5-10 kDa, and by other techniques the molecular weight may appear in the range 40-60 kDa., or in the range 10-40kDa.
The data and descriptions which have been presented herein are for the purpose of illustrating the invention and are not to be taken as limiting the scope of the invention. Other tropical forest plants, or plants from other locations, can be evaluated with regard to their containing the LAPI inhibitory and insecticidal compounds described herein. It is within the scope of this invention that those skilled in the art, using the teachings herein, will be able to extract, purify and isolate, from the plants of tropical forests and other locations, LAP inhibitors analogous to that which is described herein.
Transgenic Uses
Those skilled in the art of plant genetics, using the genetic techniques which have been developed over the last several decades, can transfer the gene encoding for the production of the leucine aminopeptidase inhibitor (LAPI) of the present invention into the genetic code of food and fiber crops such as corn, soybeans, squashes, cotton and similar food and fiber crops. Expression of the gene encoding the P. macroloba aminopeptidase inhibitor will enable the crops to produce the LAPI compound and thus protect themselves against attack by insect pests such as those described herein. Methods for producing transgelic plants are well known to those skilled in the art. For example, one may use, among others known to those skilled in the art, the teachings of Koziel et al., BIO/TECHNOLOGY 11: 194 200 (1993), Vaeck et al., Nature 327: 33-37 (1987), Hilder et al., Transgenic Research 4: 18-25 (1995) and Nature 330: 160-167 (1987), and Johnson et al., Proc. Natl. Acad. Sci. 86: 9871-9875, all of which are incorporated herein by reference. The sequence of the LAPI inhibitor and the gene which encodes it may be determined by methods, automated or manual, known to those skilled in the art.
While the gene encoding the LAPI substance of the claimed invention may be introduced into plants using known techniques, care must be taken that such gene is expressed. For example, Ryan et al. (24) reported on the presence of proteinaceous trypsin inhibitors and lectins in the seeds of a number of leguminous plants and suggested that these proteins may play a role in the plants' defenses against insect attack. Hilder et al. (18) introduced the Bowman-Birk trypsin inhibitor gene from soybeans into tobacco plants and showed that the transgenic plants were able to resist damage from a lepidopteran insect. Likewise, transformation and expression of other trypsin inhibitor genes such a Potato TI I and II also resulted in transgenic plants which showed resistance to insect attack. However, transgenic plants which contained an unexpressed gene were susceptible to insect attack (20). Consequently, in order to have pest protection, a plant must not only contain the protective gene or genetic sequence, but must also express it. That is, the transgenically inserted gene must be producing, or be capable of producing upon pest attack, the inhibitor or defensive agent. Furthermore, the choice of substance to be inserted into a plant species for pest control is also critical. Christeller et al. (15), using trypsin inhibitors from different plant species, have demonstrated that TI's have considerably different inhibitory constants (K i values). | The invention comprises a leucine aminopeptidase inhibitor (LAPI) having hemagglutination activity which is extracted from the seeds of Pentaclethra macroloba. The crude extract was found to comprise an active species having a molecular weight in the range 1.5-60 kilodaltons and further comprises an amino acid containing component, a fluorescent component and sugars. The basic unit of the active species contains approximately the following type and number of amino acid residues averaged over a plurality of separations and analyses: 3 aspartate, 3 threonine, 4.5 serine, 3.75 glutamic, 6.5 glycine, 3.5 alanine, 2.25 valine, 1.25 isoleucine, 2 leucine, 0.75 tyrosine, 1.25 phenylalanine, 5.25 lysine, 0.75 histidine, 2.25 arginine and 0.625 proline, and forms multimers, adduct, conjugate and similar species between by itself or with proteinaceous, fluorescent and sugar substance which may also be present. The active substance(s) act as an insecticide and have been found to increase insect mortality in bioassays. The active substance(s) are particularly effective against European corn borer larvae. | 0 |
BACKGROUND OF THE INVENTION
The present invention generally relates to communication systems and equipments having a plurality of terminals and an exchange network and, more particularly, to a system for interconnecting an exchange network and a terminal having a communication ability with a plurality of communication band widths as a television conference system.
In a prior art system, a control circuit in a distributed module sets a communication band at a send/receive line circuit according to an idle band of a communication channel as disclosed in JP-A-63-296530, whereas a controller in a network interface instructs a communication band to the terminal controller of a terminal interface according to the value of a traffic status from a network to take a coincidence in communication band between variable band terminals as disclosed in JP-A-1-138837.
However, the prior art system has had such a problem that no consideration is paid to such a system as to perform direct communication band data exchange between terminals to take a communication band coincidence therebetween and thus the prior art system cannot be applied to a television conference system or the like.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a communication system and equipment which can execute a communication procedure necessary for setting of a communication band width with a party variable band terminal to make the most of the characteristic of a terminal which can change its communication band width during communication and to obtain as many call interconnections as possible.
In accordance with the present invention, a system for connecting an exchange network and a plurality of communicatable terminals each having a plurality of communication bands is arranged so that the exchange network can issue a communication band width change request notification to the associated terminal, whereas the terminal, when receiving the notification, decides whether or not its band width is changed depending on the then state of the terminal and when determining the change of the band width, executes a procedure necessary for the band width change with the party communication terminal.
Since the communication band is determined depending on the communication between the terminals in this way, the communication system can have many call interconnections even during communication between such terminals demanding a wide band as television conference devices.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A, FIG. 1B, FIG. 1C are an arrangement of a communication system in accordance with an embodiment of the present invention;
FIG. 2 is a diagram for explaining a communication start procedure between moving picture transmission devices;
FIG. 3 is a diagram for explaining a procedure of decreasing a communication band;
FIG. 4 is a diagram for explaining a procedure of increasing a communication band; and
FIGS. 5(A) and 5(B) are examples of respective tables stored in terminal data memories.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
An embodiment of the present invention will be explained with reference to the accompanying drawings. FIG. 1 (FIG. 1A, FIG. 1B, FIG. 1C) is an arrangement of a communication system in accordance with an embodiment of the present invention, while FIGS. 2, 3, 4 and 5 are diagrams for explaining the protocol and table structure used in the system.
Referring first to FIG. 1, the system of FIG. 1 includes an exchange network 400 which in turn has exchanges 100 and 200. More in detail, the exchanges 100 and 200 comprise integrated services digital network (ISDN) basic rate interface line controllers 103, 104 and 203 and 204 connected respectively to ISDN basic rate interface lines 160, 170 and 260, 270, ISDN primary rate interface line controllers 102, 105 and 202, 205 connected respectively to an ISDN primary rate interface lines 150, 180 and 250, 280, analog telephone line controllers 106 and 206 connected to analog telephone lines 190 and 290, high-speed digital leased line controllers 107 and 207 connected to a high-speed digital leased line 300 connected between the exchanges 100 and 200, exchange switches 108 and 208 for performing switching operations between the extension lines of terminals 110, 120, 130, 140 and 210, 220, 230, 240 connected to the exchanges, e.g., between the extension lines of the terminals 120, 140 and 220, 240 or between these extension lines and the high-speed digital leased line, terminal data memories 109 and 209 for storing therein terminal data including the communication band type of a variable band terminal which can change its communication band therein, e.g., of such a moving picture transmission device as a television conference device and also including its communication range, and main controllers 101 and 201 connected to the above parts for controlling the parts, respectively. The terminal data memories 109 and 209 have such tables, for example, as shown in FIG. 5 respectively. More specifically, each table shows a relationship between the extension terminal No. for each terminal, the band type indicative of whether or not the associated communication band is variable and the associated range data (such as 384 kbps/768 kbps, etc.).
The terminals 110 and 210, which can change their communication bands, comprise respectively such a moving picture transmission device as a television conference device mentioned above. The moving picture transmission devices 110 and 210 have control channel controllers 111 and 211 connected to the ISDN basic rate interface lines 160 and 260 (including a D channel), data channel controllers 113 and 213 connected to the ISDN primary rate interface lines 150 and 250, cameras 117 and 217, moving picture compressors 114 and 214 for compressing respective moving pictures from the cameras, moving picture expanders 115 and 215 for expanding the respective moving pictures of the cameras, displays 118 and 216 for displaying the moving pictures thereon, control panels 119 and 219, control panel interfaces 116 and 216, and terminal controllers 112 and 212 connected to the aforementioned controllers 111, 113, compressor 114, expander 115, interfaces 116, 212, 213, 114, 215, 216 for controlling these parts, respectively. The moving picture transmission devices 110 and 210 use the respective D channels of the ISDN basic rate interface lines 160 and 260 in the control of call setting (call setting message, answering message) between the terminals and in the communication of band data (allocated-band notifying message), and also use one or more than one HO channel of the ISDN primary rate interface lines 150 and 250 in the transmission of the moving picture.
As an example, the terminals 120 and 220 may be such ISDN basic rate interface terminals as a telephone set(s) and/or a G4 facsimile machine(s) connected to the ISDN basic rate interface lines 170 and 270, the terminals 130 and 230 may be such an ISDN primary rate interface terminals as a computer(s) and/or a picture terminal(s) having a fixed communication band connected to the ISDN primary rate interface lines 180 and 280, and the teminals 140 and 240 may be such terminals as a telephone set(s) and/or a G3 facsimile machine(s) connected to the analog telephone lines 190 and 290.
Although each of the terminals comprises a single terminal in the above embodiment, each terminal may comprise a plurality of terminals or some of the terminals may be omitted with the same arrangement.
Explanation will next be made as to the call setting (communication start) protocol between the moving picture transmission devices 110 and 210 and as to the protocols for increasing and decreasing the communication band, by referring to the drawings.
First of all, the call setting (communication start) protocol will be explained with reference to FIGS. 1 and 2. In FIG. 2, single lines represent communication lines on the D channel of the ISDN basic rate interface lines 160 and 260; while double lines represent communication lines on the HO channel of the ISDN primary rate interface lines 150 and 250. FIG. 2, further, shows the case where two of the HO channels can be used. Explanation of the other part of the procedure, which is not directly related to the present invention, is omitted.
In the drawing, the terminal controller 112 of the moving picture transmission device 110, when receiving a user's call setting operation from the control panel 119, i.e., a call setting command (setting operation for the first HO channel), sends an instruction to the control channel controller 111 to issue a call setting message therefrom. The control channel controller 111, when receiving the command from the terminal controller 112, sends a call setting message 1a to the ISDN basic rate interface line 160. That is, the call setting message 1a is supplied from the control channel controller 111 to the ISDN based interface line controller 103 of the exchange 100. The controller 103, when receiving the message 1a, issues a notification indicative of the reception of the message to the main controller 101. The main controller 101, when receiving the notification, issues to the high-speed digital leased line controller 107 a command to output a call setting data 1a' of the call setting message 1a onto the high-speed digital leased line 300 from the controller 107. The controller 107, when receiving the command, outputs the call setting data 1a' onto the high-speed digital leased line 300. The call setting data 1a' is supplied to the high-speed digital leased controller 207 of the exchange 200. The controller 207, when receiving the call setting data 1a', issues to the main controller 201 a notification indicative of the reception of the call setting data. The main controller 201, when receiving the notification, issues to the ISDN basic rate interface line controller 203 a command indicative of output of a call setting message 2a from the controller 203 to the ISDN basic rate interface line 260. The controller 203, when receiving the command from the controller 207, outputs the call setting message 2a onto the line 260. The call setting message 2a is then supplied to the control channel controller 211 of the moving picture transmission device 210.
The controller 211, when receiving the call setting message 2a, issues to the terminal controller 212 a notification indicative of the reception of the call setting message. The terminal controller 212, when receiving the notification from the controller 211, issues to the control channel controller 211 a command indicative of output of an answering message 2b from the control channel controller 211 to the line 260. The controller 211 responsive to the command outputs the answering message 2b to the line 260. The the answering message 2b is then supplied to the line controller 203 of the exchange 200. The controller 203, when receiving the answering message 2b, issues to the main controller 201 a notification indicative of the reception of the answering message. The main controller 201, when receiving the notification, issues to the controller 207 a command indicative of output of an answering data 2b' of the answering message 2b from the controller 207 to the high-speed digital leased line controller 300.
The main controller 201 retrieves the terminal data memory 209, decides the usable communication band and range of the moving picture transmission device 210 as well as a communication allocation band to the moving picture transmission device 210 on the basis of the usage ratio of the high-speed digital leased line 300, issues to the controller 203 a command indicative of output of an allocated-band notification message 2c (communication band change request) from the controller 203 to the line 260 based on the communication band data, and also control the exchange switch 208 to set a communication path between the ISDN primary rate interface line controller 202 and the high-speed digital leased line controller 207 (connect the controllers 202 and 207). The control channel controller 211 of the moving picture transmission device 210 receives the aforementioned allocated-band notification message 2c and informs the terminal controller 212 of the reception of the allocated-band notification message 2c. The controller 212 controls the data channel controller 213 which in turn, under control of the controller 212, outputs onto the ISDN primary rate interface line 250 an ability data exchange message 2d indicative of use of a band width specified by the allocated band data of the allocated-band notification message 2c as its own terminal transfer rate ability. The ability data exchange message 2d is sent to the high-speed digital leased line 300 through the communication path set by the exchange switch 208 as mentioned above.
The high-speed digital leased line controller 107 of the exchange 100 receives the answering data 2b' from the line 300 and issues to the main controller 101 a notification indicative of the reception of the answering data. The main controller 101, when receiving the notification, controls the line controller 103 which in turn outputs an answering message 1b onto the line 160 under control of the controller 101.
The main controller 101 retrieves the terminal data memory 109, decides the usable communication band and range of the moving picture transmission device 110 as well as a communication allocation band to the moving picture transmission device 110 on the basis of the use frequency of the high-speed digital leased line 300, issues to the controller 103 a command indicative of output of an allocated-band notification message 1c (communication band change request) from the controller 103 to the line 160 based on the communication band data, and also control the exchange switch 108 to set a communication path between the ISDN primary rate interface line controller 102 and the high-speed digital leased line controller 107 (connect the controllers 102 and 107). The controller 107 transmits the ability data exchange message 2d of the leased line 300 to the exchange switch 108 and then is guided via the aforementioned communication path to the interface line 150.
The control channel controller 111 of the moving picture transmission device 110 receives the answering message 1b and the allocated-band notification message 1c, and issues to the terminal controller 112 a notification indicative of the reception of these messages. The terminal controller 112, when receiving the notification from the controller 111, controls the data channel controller 113, which in turn, under control of the controller 111, outputs onto the ISDN primary rate interface line 150 an ability data exchange message 1d indicative of use of a band width specified by an allocated band data 1c' of the allocated-band notification message 1c as its own terminal transfer rate ability. The ability data exchange message 1d is sent to the ISDN primary rate interface line 250 via such a communication path as mentioned above, that is, via the ISDN primary rate interface line controller 102, exchange switch 108, the high-speed digital leased line controller 107, the high-speed digital leased line 300, the high-speed digital leased line controller 207, exchange switch 208 and the ISDN primary rate interface line 202. The data channel controller 213 of the moving picture transmission device 210 receives the ability data exchange message 1d and issues to the terminal controller 112 a notification indicative of the reception of the ability data exchange message. The terminal controller 112 compares the communication band indicated in the ability data exchange message 1d with the communication band indicated in the ability data exchange message 2d and decides smaller one of the both communication bands as a communication band to be actually used. In the example of FIG. 2, the two HO channels are used so that, after setting of the first HO channel is completed, setting of the second HO channel is carried in the same manner as mentioned above. That is, the moving picture transmission device 110 sends a call setting message 1e to the exchange 100. The exchange network 400 operates in the same manner as the above and sends a call setting message 2e to the moving picture transmission device 210. The moving picture transmission device 210 sends a answering message 2f to the exchange network 400, which in turn sends an answering message 1f to the moving picture transmission device 110. As a result, the second HO channel can be used. The terminal controllers 112 and 212 of the moving picture transmission devices 110 and 210 set a moving picture compression rate between the moving picture compressors 114, 214 and the moving picture expanders 115, 215 to correspond to 2 HO (=768 kbps), and operate the data channel controllers 111 and 211 to start the transmission of the moving picture, respectively.
Explanation will then be made as to a procedure of reducing the communication band during the communication after the aforementioned call setting operation, by referring to FIG. 3. The main controller 101 of the exchange 100, when detecting that the use frequency of the high-speed digital leased line 300 becomes higher than a predetermined value, retrieves the terminal data memory 109 to examine the presence or absence of at least one moving picture transmission device in the terminals 110, 120, 130 and 140 in communication. This is realized by checking the presence or absence of the extension terminal No. having a variable communication band in the table (refer to FIG. 5) of the memory 109. When the moving picture transmission device 110 is present as shown in FIG. 1 and can communicate below the communication band currently being used by the terminal, the moving picture transmission device 110 controls the ISDN primary rate interface line 103 which in turn, under control of the controller 110, sets a reduced allocated-band data in an allocated-band notification message 1g and sends the message 1g onto the ISDN basic rate interface line 160. Whether or not the terminal 110 is communicatable below the communication band currently being used can be known by checking the associated communication band range of the table of the memory 109. The control channel controller 111 of the moving picture transmission device 110, when receiving the allocated-band notification message 1g, informs the terminal controller 112 of the reception of the message 1g. The terminal controller 112 controls the data channel controller 113 which in turn, under control of the controller 112, sends to the exchange network 400 an ability data exchange message 1h indicative of use of the band width specified by the allocated-band data within the allocated-band notification message 1g as its own terminal transfer rate ability. The exchange network 400 sends the ability data exchange message 1h to the moving picture transmission device 210. The data channel controller 213 of the moving picture transmission device 210, when receiving the ability data exchange message 1h, informs the terminal controller 212 of the reception of the message 1h. The terminal controller 212, when receiving the message 1h, controls the moving picture compressor 214, moving picture expander 215 and data channel controller 213, sets the moving picture companding ratio of the moving picture transmission device 210 to correspond to one HO (=384 kbps), and stops the use of the second HO channel. The terminal controller 212 controls the data channel controller 213 and sends to the exchange network 400 an ability data exchange message 2h indicative of use of the same communication band as the specification band of the ability data exchange message 1h. The ability data exchange message 1h is used to be transferred between the moving picture transmission devices 110 and 210 to know whether or not the communication band can be changed to the allocated band by the exchange network 400. The exchange network 400 sends the ability data exchange message 2h to the moving picture transmission device 110. The data channel controller 113 of the moving picture transmission device 110, when receiving the ability data exchange message 2h, informs the terminal controller 112 of the reception of the message 2h. The terminal controller 112 operates the moving picture compressor 114, the moving picture expander 115 and data channel controller 113 to stop the use of the second HO channel. The terminal controller 112 also controls the control channel controller 111 to send a disconnect message 1i to ISDN basic rate interface line 160. The ISDN basic rate interface line controller 103 of the exchange 100, when receiving the disconnect message 1i, informs the main controller 101 of the reception of the message 1i. The main controller 101 controls the high-speed digital leased line controller 107 which in turn, under control of the controller 101, sends a disconnect data 1i' to the high-speed digital leased line 300. The main controller 101 controls the ISDN basic rate interface line controller 103 which in turn, under control of the controller 101, sends a release message 1j to the ISDN basic rate interface line controller 103. The main controller 101 also controls the exchange switch 108 to release the communication path which has been allocated to the second HO channel. The high-speed digital leased line controller 207 of the exchange 200 informs the main controller 201 of the disconnect data 1i' received from the high-speed digital leased line 300. The main controller 201 controls the ISDN basic rate interface line controller 203 which in turn, under control of the controller 201, sends to the ISDN basic rate interface line 260 the disconnect data 1i' as a disconnect message 2i. The main controller 201 also controls the high-speed digital leased line controller 207 and exchange switch 208 to release the communication path allocated to the second HO channel. The control channel controller 211 of the moving picture transmission device 210, when receiving the disconnect message 2i, informs the terminal controller 212 of the reception of the message 2i. The terminal controller 212 controls the control channel controller 211 which in turn, under control of the controller 212, sends a release message 2j to the ISDN basic rate interface line 260. The ISDN basic rate interface line controller 203 of the exchange 200 informs the main controller 201 of the reception of the release message 2j. The main controller 201 controls the ISDN basic rate interface line controller 203 which in turn, under control of the controller 201, sends a release completion message 2k to the ISDN basic rate interface line 260. The control channel controller 211 of the moving picture transmission device 210 informs the terminal controller 212 of the reception of the release completion message 2k. The control channel controller 111 of the moving picture transmission device 110 informs the terminal controller 112 of the reception of the release message 1j. The terminal controller 112 operates the control channel controller 111 to send a release completion message 1k to the ISDN basic rate interface line 160. The ISDN basic rate interface line controller 103 of the exchange 100 informs the main controller 101 of the reception of the release completion message 1k.
When part of the communication path is released according to such a procedure as mentioned above, the use frequency of the high-speed digital leased line 300 can be decreased by an amount corresponding to the HO channel, and thus the other ISDN basic rate interface terminal 120, the ISDN primary rate interface terminal 130 and analog terminal 140 can use the high-speed digital leased line 300.
Explanation will next be made as to a procedure of expanding the communication band being communicated. The main controller 101 of the exchange 100, when detecting that the use frequency of the high-speed digital leased line 300 becomes larger than a predetermined value, retrieves the terminal data memory 109 to examine whether or not the terminal in communication is of the moving picture transmission device. When the moving picture transmission device 110 is present and is communicatable above the communication band currently being used by the terminal, the moving picture transmission device 110 controls the based ISDN basic rate interface line controller 103 which in turn, under control of the device 110, sets an enlarged allocated-band data in an allocated-band notification message 11 to send the message 1g to the ISDN basic rate interface line 160. The control channel controller 111 of the moving picture transmission device 110 informs the terminal controller 112 of the reception of the allocated-band notification message 11. The terminal controller 112 controls the data channel controller 113 which in turn, in order to change the communication band to the allocated band, sends to the exchange network 400 an ability data exchange message 1m indicative of use of the band width specified by the allocated band data within the allocated-band notification message 1l as its own terminal transfer rate ability under control of the controller 112. The exchange network 400 sends the ability data exchange message 1m to the moving picture transmission device 210. The data channel controller 213 of the moving picture transmission device 210 informs the terminal controller 212 of the reception of the ability data exchange message 1m. The terminal controller 212 receives the message 1m and controls the data channel controller 213 which in turn, under control of the controller 212, send to the exchange network 400 an ability data exchange message 2m indicative of use of smaller one of its own terminal transfer rate ability and the allocated band indicated in the allocated band notification received lastly from the exchange 200 as its own terminal transfer rate ability. The exchange network 400 sends the ability data exchange message 2m to the moving picture transmission device 110. The data channel controller 113 of the moving picture transmission device 110 informs the terminal controller 112 of the reception of the ability data exchange message 2m. The terminal controller 112 determines smaller one of the communication band indicated in the ability data exchange message 1m and the communication band indicated in the ability data exchange message 2m as a communication band to be actually used. FIG. 4 shows the case where an additional one HO channel can be used. More specifically, the second HO channel can be used through the transfer of call setting messages 1n and 2n and answering messages 1o and 2o between the moving picture transmission devices 110 and 210 in the same manner as the call setting message 1e and 2e and answering messages 1f and 2f in FIG. 2. The terminal controllers 112 and 212 of the moving picture transmission devices 110 and 210 set the moving picture companding ration between the moving picture compressors 114 and 214 and the moving picture expanders 115 and 215 to correspond to 2HO (=768 kbps) and operate the data channel controller 111 and 211 to restart the transmission of the moving picture.
Although the allocated band from the exchange network 400 has been unconditionally used for the moving picture transmission device 110 in the foregoing embodiment, the control panel 119 may have a function of, for example, turning ON/OFF the setting of a high definition mode, whereby, when the terminal user set the high definition mode, band reduction can be carried out. To this end, the moving picture transmission device 110 is arranged merely to ignore the allocated-band notification from the exchange network 400.
As an alternative, the moving picture transmission device 110 may be arranged, when receiving the allocated-band notification from the exchange network 400, to operate the moving picture expander 115 and to display on the display 118 an inquiry saying whether or not the band change is effected by the terminal user and to determine the change or non-change of the band change through user's input from the control panel 119.
Further, picture transmission device 110 may be arranged to operate the moving picture expander 115 and to display the communication band width being used on the display to allow the terminal user to visually know the communication band width on the display.
Though the exchange 100 performs its band width changing operation depending on the use frequency of the relay line in the foregoing embodiment, band widths previously allocated to the moving picture transmission device 110 with respect to different time bands may be set for the exchange 100 so that the moving picture transmission device 110 can perform its band width changing operation according to the set data therein.
Further, the exchange 100 may perform its band width changing operation based on the use frequency of the exchange switch 108.
The communication band data which picture transmission device 110 can use is previously set in the terminal data memory 109 in the foregoing embodiment. However, a procedure for informing the exchange 100 of the communication band data which the picture transmission device 110 can use may be added to the calling procedure between the picture transmission device 110 and the exchange 100, so that, each time the picture transmission device 110 calls, the communication band data can be stored in the exchange.
The communication mode of the picture transmission device 110 may be changed during communication through the control panel 119 so that, each time the usable communication band width is changed, the procedure for informing the exchange 100 of the usable communication band data can be added.
Further, the moving picture transmission device 110 is used as the variable band terminal in the foregoing embodiment, but a television conference device may be similarly employed for the variable band terminal.
Furthermore, transmission band width of zero may be set as one of the usable communication band widths in the moving picture transmission device 110, zero may be provided in the communication band range in the table of the terminal data memory of the exchange 400, in which case, a moving picture frame, which has been already received prior to it, may also be displayed in the form of a still picture.
In accordance with the present invention, the communication band to be used between the moving picture transmission devices can be controlled from the exchange network. As a result, the moving picture transmission device can use its maximum band when a sufficient amount of resources are provided within the exchange network, while the band to be used by the moving picture transmission device is decreased to allow communication of another terminal when a less amount of resources are provided within the exchange network, whereby the moving picture transmission device can connect as many calls as possible even in its communication mode. | A communication system having an exchange network which can execute a communication procedure necessary for setting of a communication bandwidth with a party variable bandwidth terminal to make the most of characteristic of a terminal which can change its communication bandwidth during communication and to obtain as many call interconnections as possible. The exchange network includes a variable terminal attribute memory device for storing therein the types and ranges of variable bandwidths of the terminals, a bandwidth decision device for determining bandwidths allocated to the respective terminals, and a control data communication device for transmitting at least an allocated bandwidth data to the associated terminal. The variable bandwidth terminal at least includes a control data communication device for receiving the allocated bandwidth data from the exchange network, a line management device for performing access management of lines, and a terminal control device for determining a communication band-width based on the allocated bandwidth data received from the exchange network and the then terminal state to execute a communication procedure with the party terminal and to operate the line management device to increase or decrease the communication bandwidth. | 7 |
CROSS REFERENCE TO RELATED INFORMATION
[0001] This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/471,484, filed Apr. 4, 2011.
TECHNICAL FIELD
[0002] The present disclosure is directed to machine-to-machine communications and monitoring, and more particularly to monitoring the usage of communications networks by each of a large number of distributed mobile units.
BACKGROUND OF THE INVENTION
[0003] Many companies use large numbers of mobile assets such as vehicles, shipping containers, barges, commercial equipment, palettes, and other similar objects in their everyday business. Other companies and industries use remote sensors to collect data that is used in their businesses. More and more companies are turning to remote asset tags, sensors and tracking devices to obtain access to remotely collected data, continuous location and status updates on those mobile objects and sensors. These remote devices use a wide range of existing satellite, cellular and other tracking services to keep tabs on the mobile or remote objects. In many instances, those remote devices also use cellular, wireless networking, or even satellite communications to report their location, data and/or status to a monitoring center.
[0004] The cellular (or satellite) operators may charge by the minute or by the kilobyte for their services, or may have a flat fee per month, or other billing period, for usage below a threshold with per minute or per kilobyte charges over the threshold. These additional charges can mount quickly and can incur large excess charges for the owner of the mobile objects. These overages can result from the normal operation of the devices or can result from a malfunctioning device that uses far more cellular bandwidth than intended.
[0005] What is needed is a system that can monitor communication and communication patterns of mobile objects/units and to act when those units approach a usage threshold.
BRIEF SUMMARY OF THE INVENTION
[0006] An embodiment of a method for monitoring the communications of remote devices is described where the method receives data on communications usage from each of a plurality of remote devices and analyzes the communications for each of the plurality of remote devices to determine when that remote device is approaching a usage threshold. The method then can take appropriate corrective action in response to the analysis.
[0007] In another embodiment, a method for monitoring the communications of remote devices is described that receives data on communications usage from each of a plurality of remote devices, and analyzes the communications for each of the plurality of remote devices against a historical pattern of usage for that remote device to determine when that remote device is malfunctioning. The method then can take appropriate corrective action in response to the analysis.
[0008] In yet another embodiment, a system and method of monitoring the communications of remote devices is described. The system includes a plurality of remote devices, where each remote device has one or more sensors and a communications transceiver. A control center, which includes a historical usage database reflecting historical usage patterns for each of the plurality of remote units, analyzes the communications for each of the plurality of remote devices against the historical usage patterns for that remote device to determine when that remote device is malfunctioning or approaching a usage threshold. The control center is then operable to take appropriate corrective action in response to the analysis.
[0009] The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that, the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. The novel features which are believed to be characteristic of the invention, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] For a more complete understanding of the present invention, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:
[0011] FIG. 1 is a block diagram of an embodiment of a system for monitoring the communications and communication patterns of multiple mobile units;
[0012] FIG. 2 is a block diagram of an embodiment of an asset tag for a mobile unit having location and status determining capabilities; and
[0013] FIG. 3 is a flow chart for an embodiment of a method for monitoring and managing the communications of remote devices.
DETAILED DESCRIPTION OF THE INVENTION
[0014] Excess usage of the communications networks by the mobile units can result in large overage charges by the network providers. Excess usage can come from deviations from normal operating conditions, such as a device that is in the field longer than normal, or more devices in the field that is usual, or can come as a result of a malfunctioning device that transmits data more often than intended. In either event, the operator or owner of the devices would only become aware of the problem after they have received a bill for the excess airtime. Embodiments of the present invention monitor the communications of each mobile device and analyze that information in view of historical usage and patterns to detect malfunctioning devices or devices that are approaching a usage threshold.
[0015] Referring now to FIG. 1 , the present invention describes an embodiment of a system 100 for monitoring the communications of a large number of remote or mobile units 101 a through 101 e that are programmed to report location, data and/or status periodically, in response to an event, or in response to a request by a monitoring center. The mobile units use cellular or satellite (not shown) networks to send data to a control or monitoring center 105 which collects the location and/or status data for each of the mobile units 101 a through 101 e. While a cellular network having cell stations 102 and carrier network 103 are shown communicating with a provider network 104 connected to control center 105 , any type or combination of communications network can be used without departing from the scope of the concepts described herein. Other examples of communications networks may include satellite, wireless networking, radio frequency or any other network with the requisite functionality.
[0016] The control or monitoring center 105 monitors each device 101 a through 101 e. In addition to a historical usage database for the mobile units 106 , the control center 105 can keep a current usage database 107 for each device and groups of devices. By monitoring the communications, the monitoring center can detect deviations from historical communication patterns that result from malfunctioning devices and can also detect devices that are approaching usage threshold and can either disable those devices or send alerts to the operator/owner/manager 108 of the device to allow the owner to take corrective action if desired.
[0017] The system preferably uses the data channels of cellular networks 103 to communicate with the remote devices, but can use any wireless communications technology available to the mobile unit, including satellite and wireless networking technologies. In addition the protocols used in preferred embodiments of the system are agnostic to technical details of the specific devices and can be used across a spectrum of devices and technologies. While a particular number of mobile units are represented in FIG. 1 , any number of mobile units can be accommodated using the concepts described herein.
[0018] Referring now to FIG. 2 , an embodiment of a remote sensor or mobile asset tag that can be used with each remote or mobile unit is described. The unit, or tag, 200 includes a microprocessor 201 programmable to execute desired instructions and to control the operation of tag 200 . The processor 201 may have internal memory capable of storing data and programming information or may use memory external to the microprocessor. The tag 200 also includes a cellular transceiver 202 and associated cellular antenna 203 to perform cellular communications. Power for the cellular transceiver is supplied by RF power module 208 . The tag 200 also includes a satellite location determination device 204 , which can be GPS or satellite service based, and a satellite transmitter, receiver or transceiver 206 , which uses satellite antenna 205 .
[0019] As described, communications with the control center can be done using satellite, cellular or other long range communication systems. Sensors 209 , 210 can be embedded in or connected to the device to collect data, detect motion, detect the presence of another object, or any other type of data or environmental information. Such information can be collected and reported to the data center or can also be used to trigger actions by the mobile device. Reed switch 207 is an electrical switch that is activated by a magnetic field and can be used to enable or disable the device. While unit 200 is shown with a particular combination of sensors and communication elements, the specific configuration of each device can vary according to its intended use and may include a particular sensor or array of sensor, may include one communications system or multiple communications systems, and may include any of a variety of location determination modules or none at all.
[0020] Referring now to FIG. 3 , a flow chart of an embodiment of a method 300 for monitoring and managing the communications of remote devices/mobile units is described. The method, as shown in block 301 , receives or tracks usage data for each mobile unit by either directly monitoring the communications, receiving usage updates from the mobile unit or receiving usage data from the network carrier. That data is then analyzed, as shown in block 302 , in conjunction with historical usage data 303 for the device. The method then proceeds to determine, based on the analysis, whether that particular mobile unit is approaching a usage threshold, as shown in block 304 . If a usage threshold is approaching, the monitoring center can take appropriate action, as shown by block 306 . The method also determines, shown by block 305 , if the mobile unit is operating outside of historical norms and could be malfunctioning. If there is deviation from the historical usage pattern, the monitoring center can again take appropriate action, as shown by block 306 .
[0021] Appropriate action in preferred embodiments includes sending notices to the owner/operator/manager of the mobile unit, or disabling the communications of the mobile unit in question. Disabling the mobile unit can involve sending new instructions to the unit, or more preferably removing the mobile unit from the associated home location register (HLR). The disabling action could be temporary, i.e. until the start of the next billing cycle, or could be more permanent in the case of a malfunctioning device, disabling it until the device can be serviced to correct the error.
[0022] The data collection and analysis can be performed on any time frame, but is preferably done regularly over short intervals to ensure that a malfunctioning device is caught quickly. For example, the usage data can be analyzed hourly looking for deviations from historical patterns.
[0023] Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present invention, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps. | A system and method of monitoring the communications of remote devices is described. The system includes a plurality of remote devices, where each remote device has one or more sensors and a communications transceiver. A control center, which includes a historical usage database reflecting historical usage patterns for each of the plurality of remote units, analyzes the communications for each of the plurality of remote devices against the historical usage patterns for that remote device to determine when that remote device is malfunctioning or approaching a usage threshold. The control center is then operable to take appropriate corrective action in response to the analysis. | 7 |
BACKGROUND AND SUMMARY OF THE INVENTION
In the processing of tubular knitted fabric, it is common to pass the tubular fabric over an internal spreader, which distends the fabric tube laterally to relatively flat form and uniform width. When processed in "dry" condition, the fabric is often steamed while on the spreader, and then discharged directly into a processing station, such as a pair of calender rolls, a compressive shrinkage station, or the like. In some cases, the spread fabric is discharged from the spreader into a wet processing apparatus, such as a pad. Representative forms of prior art spreaders are reflected in, for example, the Robert Frezza U.S. Pat. No. 3,875,624 and in the S. Cohn et al U.S. Pat. No. 2,228,001. In those representative spreading apparatuses, a spreader frame comprises spaced, opposed spreader frame sections, typically carrying movable belts which engage the inner edge walls of the distended fabric.
At the transverse working axis of the spreader frame, there are provided opposed pairs of so-called radius rolls which engage through the fabric wall with grooved edge drive rolls. When the edge drive rolls are moved laterally into contact with a horizontally disposed spreader frame, the spreader frame is positioned and supported both vertically and horizontally by the inter-engaging geometry of the external edge drive rolls and the internal pairs of radius rolls.
Typically, the width of a tubular fabric spreader is adjustably established by means of an internal spacer bar, extending from one side to the other of the frame along the transverse working axis, and various arrangements have been provided in the prior art apparatus for adjusting the length of the spacer bar. One advantageous form of such adjustment is reflected in the S. Cohn et al U.S. Pat. No. 2,228,001. The mechanism includes a movable latch lever, which may be gripped by the hand, to permit telescopic movement of elements of the spacer bar.
In prior art equipment of which the applicant is aware, it has always been necessary to stop the processing line in order to effect width adjustment of the spreader frame. This is required by the fact that the spreader is completely enclosed by the moving tubular fabric, and the only way that access can be gained to the internal mechanism is through the wall of the fabric. Once the processing line has been stopped, it is usually possible to manipulate the adjusting mechanism by distorting the wall of the fabric, working by "feel". In some cases, however, it is necessary to cut an opening in the fabric in order to make a width adjustment.
Even in cases where it has not been necessary to cut or distort the fabric, the practical problems involved in temporarily stopping the processing line for width adjustment of the spreader seriously discourage the making of any such adjustments during a processing run. In this respect, if the fabric is held motionless for a period of time in a processing stage, such as a calender, compactor or pad, the fabric may be off specification in the area exposed to excessive time in the processing stage, and may have to be cut out and discarded. Under the best of circumstances, width adjustment involves at least an undesirable and time-consuming interruption in an otherwise continuous processing operation.
Efforts in the past have been made to provide automatic adjustment by utilization of spring arrangements in conjunction with the spacer bar, urging the opposite side of the spreader frames in a separating direction. These arrangements have proved impractical, however, because effective spring force decreases markedly with increasing width, while, in general, greater force is required to retain the spreader frames at wider widths than at narrower widths.
Pursuant to the invention, a novel and improved spreader frame structure is provided, in which a relatively constant force yieldable means is provided for yieldably maintaining separation of the spreader frames, in a manner accommodating expansion and contraction of the spreader width, under the control of the external edge drive rolls, within a reasonable range of adjustment, and without excessive variation in contact pressure on the fabric wall which is interposed between the radius rolls and the edge drive rolls. More particularly, the apparatus of the invention includes a spreader frame in which the opposed spreader frame elements are connected by a telescopic spacer assembly, urged in an extending or widening direction by a so-called gas spring which, within the limits of its extension, has a reasonably uniform range of extending force. The arrangement is such that, within the range of operation of the telescoping spacer unit, the width of the spreader frame may be effectively controlled by increasing and decreasing the spacing of the external edge drive rolls. This may be accomplished as an in-process adjustment, either manually or from a remotely located control station. Moreover, the arrangement lends itself to automatic, continuous width monitoring and adjustment, in order to achieve greater uniformity in the processed width of the fabric.
In its simplest form, the spreader apparatus of the invention incorporates a telescopic spacer assembly, which extends between opposed spreader frame sections at the transverse working axis and serves to provide mechanical alignment of the frame sections to maintain the sections substantially in parallel relation. Associated with the telescoping assembly is an extendable gas spring unit, which is connected so as to be isolated from non-axial forces and which is contained within a telescoping type of housing structure, so as to be free of contact with the fabric passing over the spreader. Typically, a spreader or frame installation may be provided with a series of two or three spacer units of graduated size ranges covering the full width capacity of the processing line. The operating range of any one of the units is sufficient to accommodate automatic width adjustment during the processing of a given fabric, but it may be necessary or desirable to exchange spacer units when the processing line is set up to handle a different type or size of fabric, as will be understood. In this respect, the yieldable spacer units are adapted for quick-disconnect association with the primary spreader frame sections, so that changeover of the equipment for processing different types of fabric may be accomplished in an expedited manner.
In a particularly advantageous specific form of the invention, the yieldable telescopic spacer unit is comprised of a pair of telescopically interfitting tubular sections, which may be of irregular cross section, which serve not only to enclose and protect the gas spring unit, but also to provide mechanical support for the spreader frame sections against translational displacement. Where the tubular sections are of irregular cross section, they serve additionally to resist rotational displacement. In another advantageous form of the invention, structural support of the spreader frame sections is provided by spaced, telescopically associated elements straddling the gas spring element, and the entire telescopic structure, including the gas spring, is enclosed within a flexible, bellows-type housing.
For a more complete understanding of the above and other features and advantages of the invention, reference should be made to the following detailed description of a preferred embodiment and to the accompanying drawings.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan view of a fabric finishing line incorporating an automatically adjustable spreader frame arrangement in accordance with the invention.
FIG. 2 is a top plan view of a spreader frame of the type incorporated in the processing line of FIG. 1.
FIG. 3 is an enlarged, fragmentary view of a resilient spacer unit constructed in accordance with the teachings of the invention and adapted for incorporation in the apparatuses of FIGS. 1 and 2.
FIG. 4 is a fragmentary cross sectional view as taken generally on line 4--4 of FIG. 3.
FIG. 5 is a longitudinal cross sectional view of a modified form of resiliently biased spacer unit for incorporation in the apparatuses of FIGS. 1 and 2.
FIG. 6 is a cross sectional view as taken on line 6--6 of FIG. 5
FIG. 7 is a longitudinal cross sectional view of a further modified form of resiliently biased spacer unit for incorporation in the apparatuses of FIGS. 1 and 2.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now to the drawings, and initially to FIG. 1 thereof, there is shown a typical finishing line for tubular knitted fabric, which is operative to spread the fabric to flat form and uniform width, steam and then calender the spread fabric, and then wind the fabric as it emerges from the calender station. A spreader frame 10 (see FIG. 2) is comprised of spaced, opposed spreader frame sections 11, 12 joined centrally by a spacer assembly, generally designated by the numeral 13, to be described in further detail. The respective spreader frame sections 11, 12 include central brackets 14, 15 mounting spaced pairs of radius rolls 16, 17. Frame extensions 18, 19 and 20, 21 extend in opposite directions from the respective brackets 14, 15 and mount a plurality of guide pulleys 22. The guide pulleys 22 and the radius rolls 16, 17 mount respective pairs of upstream belts 23 and downstream belts 24, which are engageable with internal edges of a tubular knitted fabric passing over the spreader frame assembly.
In accordance with known principles, the pairs of radius rolls 16, 17 are convexly contoured on their outer peripheries, for reception within concavely contoured outer peripheries of external edge drive rolls 25, 26. The arrangement is such that, when the edge drive rolls are moved into firm engagement with the respective pairs of radius rolls, the entire spreader frame is both positioned and supported by the edge drive rolls.
As illustrated in FIG. 1, the edge drive rolls 25, 26 are mounted on carriages 27 slidably supported on transverse guide rods 28, 29. A splined shaft 30 is slidably associated with the carriages 27 and is arranged to be driven by an external power source (not shown) to rotate the edge drive rolls 25, 26 at predetermined controllable speeds. The edge drive carriages 27 are also connected to a screw shaft 31, which is oppositely threaded at each end and is controllably rotatable by means such as a motor 32. When the shaft 30 is rotated, the edge drive carriages 27 are moved inwardly or outwardly, as the case may be, in unison, with respect to the longitudinal center line of the equipment.
When the edge drive rolls are in supporting engagement with the pairs of radius rolls 16, 17, rotation of the edge drive rolls, acting through a fabric wall, will cause rotation of the radius rolls 16, 17 and corresponding movement of the upstream and downstream belts 23, 24. Pursuant to known principles, the downstream radius rolls may be more deeply grooved than the upstream rolls, so that the downstream belts will travel at a somewhat lower rate of speed than the upstream belts. When this is done, the fabric is controllably overfed onto the downstream section of the spreader, from the upstream section, which is desirable in many cases.
In the specific apparatus illustrated in FIG. 1, the spreader frame is provided with a flexible wire lead-in section 33. The incoming fabric tube is applied over the lead-in section, distended laterally, and engaged internally by the upstream belts 23. Thereafter, the fabric is controllably drawn onto the spreader frame and advanced by movement of the belts. After entering the downstream section of the spreader frame, the fabric typically passes through a steaming section 34, which may be of known construction, and may typically thereafter pass through a calendering stage 35, comprising a pair of opposed calender rolls which apply rolling pressure to the fabric. The particular processing operation, however, is not significant to the invention, and it should be understood that the spreading section may deliver the fabric to any one of a variety of processing operations. In the illustrated system, the calendered fabric enters a winding stage 36, where it is wound around a core rod 37 for convenient subsequent handling.
In accordance with past practice, spacer bar assemblies incorporated with the spreader frames have been arranged to lockingly secure the spreader frame in any pre-set width-adjusted position. After pre-setting the width of the spreader, the spreader is positioned between the edge drive rolls, which are then controllably moved toward each other sufficiently to engage and mechanically support the spreader frame. The inward adjustment of the edge drive rolls is, of course, carefully done so as not to apply excessive transverse pressure to the spreader frame, and in some prior equipment, provisions are made for controllably limiting the amount of such pressure by the utilization of a controllably stalled drive motor 32 and/or switch means associated with the carriage positioning mechanism. In any case, the width of the spreader frame was previously established, and the edge drive rolls were brought into engagement with the pre-set frame.
In accordance with the present invention, however, a unique and novel arrangement is provided for yieldably separating the spreader frame sections 11, 12, such that the working width of the spreader frame, in operation, is determined by the position of the edge drive rolls 25, 26, within the operating limits of the spacer assembly 13.
Referring now more particularly to FIGS. 2-4, the spacer bar assembly 13 comprises a spaced pair of telescopically interfitting tubes 40 and rods 41. At one end, the tubes 40 are rigidly secured to a yoke bar 42, and at the opposite side, the rods 41 are secured rigidly to a similar yoke bar 43. Connecting pins 44, 45 are secured to and extend outwardly from the respective yoke bars 42, 43 and are arranged to be telescopically received within sleeves 46, 47 mounted rigidly on the respective spreader frame sections 11, 12. As shown in FIG. 3, the outer ends of the connecting pins 44, 45 are provided with outwardly opening slots 48 arranged for the reception of pins 49 extending diametrically across the insides of the tubular coupling sleeves 46, 47. The fit between the connecting pins 44, 45 and their respective coupling sleeves 46, 47 is relatively close, such that when the pins are inserted into the sleeves and engaged with the pins 49, the spacer bar assembly serves to support the spreader frame sections 11, 12 against swinging movement toward and away from each other at either end and also against rotational motion around the transverse working axis through the spacer bar assembly, assuring that the spreader frame sections 11, 12 are at all times retained in substantially parallel relation, if that is desired, or at least in a predetermined, coplanar relation. The respective spreader frame sections may move toward and away from each other, within the telescoping limits of the tubes and rods 40, 41, but will otherwise remain in a constant relationship.
Pursuant to a significant feature of the invention, the spacer bar assembly 13 is constantly urged in an extending or frame-widening direction, within pre-set limits, by means of a so-called gas spring unit 50, which is a device in the nature of an air cylinder, having a cylinder body 51 and rod 52. The gas spring unit may be of the type made commercially available as of the filing date hereof by Gas Spring Corporation, 17 Commerce Drive, Montgomeryville, Pa. In general, the gas spring unit is in the form of a sealed gas cylinder, pre-charged with a positive gas pressure and having controlled flow passage means connecting opposite sides of the piston. Under the pre-charged, permanent gas pressure, an unbalanced force is acting at all times to urge the piston and rod in an extending direction. There being a somewhat greater effective area at the closed end of the cylinder than at the rod end, in any position of the rod 52, within the limits of its travel, the pre-pressurized internal gas will continue to exert a net outward or extending force on the rod. Inasmuch as the effective area is slightly less on the rod side than on the closed side, there will be a slight decrease in gas pressure as the piston and rod moves in an extending direction, and a slight increase in pressure as the piston and rod move in the retractive direction. By appropriate selection of the relative diameters of the cylinder 51 and rod 52, the pressure differential can easily be held within acceptable limits. For example, with a gas spring unit having a cylinder diameter of 22 mm and a rod diameter of 10 mm, the reduction in pressure between fully retracted and fully extended positions may be on the order of 20-25%, over an extension of as much as 260-300 mm.
Inasmuch as the gas spring unit 50 should be as free as possible of non-linear forces, it is connected to the spacer bar assembly 13 by ball and socket joints 53, 54. As reflected in FIG. 4, for example, the yoke bars 42, 43 are provided with short, inwardly extending brackets 55, to which are secured ball posts 56 forming part of the ball and socket joints. The arrangement is such that the linear axis of the gas spring unit is substantially aligned with the connecting pins 44, 45.
In the apparatus of FIGS. 1-4, the entire telescopic mechanism of the spacer bar 13 is enclosed within a flexible bellows housing 57, so that the cloth is isolated from the mechanism and vice versa.
A modified form of the spacer post assembly is illustrated in FIGS. 5 and 6 of the drawing. In the modified form, a gas spring unit 150 is housed within a tubular telescopic assembly 151. The telescopic assembly is comprised of inner and outer tubular elements 152, 153 which are slideably received one within the other. The respective tubular members 152, 153 are of complementary, irregular cross section, typically square, so as to be restricted against relative rotation. Ball posts 154, 155 are mounted in the closed ends of the respective tubular sections 152, 153 and are engaged with sockets 156, 157 of the gas spring unit 150. End plates 158, 159 are welded or otherwise secured to the ends of the tubular sections, and these in turn mount slotted connecting pins 160, 161.
The modified spacer bar unit of FIGS. 5 and 6 functions the same as the unit of FIGS. 1-4, but is generally more compact and more easily handled. The telescoping tubular sections 152, 153, in the embodiment of FIGS. 5 and 6, serve a multiple function of providing mechanical support against swinging and rotating movement of the spreader frame section, and of housing and protecting the gas spring unit 150. The modification of FIGS. 5 and 6 is advantageous for many commercial applications of the invention, because its small size enables it to be easily handled and stored.
In FIG. 7, there is shown a further modified form of the invention, which is of highly simplified and economical construction and ideally suited for typical commerical utilization. The unit of FIG. 7 includes a gas spring element 200, which is housed within telescopically interfitting tubular guide sleeves 201, 202. In the illustration of FIG. 7, guide sleeves 201, 202 are of circular cross section, in which case they do not resist rotational displacement of the spreader frame elements to which they may be connected. In practice, rotational resistance may be unnecessary in many instances, inasmuch as the spreader frame sections will tend to be held in the proper geometric relationships by engagement with the edge drive rolls and/or other elements of the processing line.
Secured to the opposite ends of the tubular guide sleeves 201, 202 are end caps 203, 204 provided with threaded openings 205 for the reception of end-slotted connecting pins 206, 207. The inner ends of the connecting pins 206, 207 are provided with semi-spherical sockets 208 for the reception of semi-spherical end fittings 209, 210 provided respectively on the closed end 211 and the operating rod 212 of the gas spring element 200. The end fittings 209, 210 are arranged to slip freely into the sockets 208, and are held loosely therein by split roll pins 213 or the like which are inserted in bores provided therefor in the connecting pins 206, 207. Portions of the roll pins 213 project into annular grooves 214 in the gas spring end fittings, so as to maintain a loose connection.
In the assembly of the device of FIG. 7, the connecting pins 206, 207 are first attached to the ends of the gas spring element 200 and loosely fixed thereto by means of the roll pins 213. Thereafter, the telescopically fitting tubular guide sleeves 201, 202 are applied over the opposite ends of the unit, causing the ends of the connecting pins to project outward through the threaded openings 205 in the end caps. The base portion of each of the connecting pins is threaded at 215 and shouldered at 216, such that the pin may be threadedly joined to the end caps 204 to form a secure and complete assembly.
In the assembled relationship, the length of the inner telescoping tubular section 202 is such that it bottoms against the opposite end cap 204 at least a short distance prior to bottoming of the operating rod 212 of the gas spring. This prevents the gas spring element, which may be fairly delicate in construction, from having to resist the full closing force of the edge drive rolls, in the event the equipment were accidentally to be adjusted to the narrow limit position of the unit.
In either of the embodiments of FIGS. 5-6 or 7, the telescopic tubular sections advantageously may be formed of a material such as aluminum, which in turn may be coated on the working surfaces with a friction-reducing material such as "Tufram" or the like.
For a typical processing installation, a spreader frame assembly according to the invention likely would include a single pair of spreader frame sections 11, 12 and a series of two or perhaps three spacer bar units 13 arranged for interchangeable assembly with the spreader bar section and each covering a given range of width variation. In setting up the equipment for processing fabric of a given width, the spreader frame sections are assembled with a spacer bar unit of an appropriate width range. When initially assembled, the spreader frame would, of course, be at the maximum width of the range, because the gas spring unit 50 would be fully extended. The assembled spreader is then positioned between the edge drive rolls 25, 26 and the edge drive rolls are then brought together, into contact with the radius rolls 16, 17, in order to position and support the spreader frame. Thereafter, the spreader may be set to the precise desired width by moving the edge drive rolls 25, 26 further inward by appropriate rotation of the threaded shaft 31.
Desirably, adjustable stop means are provided to limit subsequent outward movement of the edge drive carriages, such that the edge drive rolls are not separated farther than the expansion limit of the spreader frame assembly. Any suitable arrangement may be provided for this purpose, such as the provision of an adjustable stop collar 58 on the shaft 31, arranged either to stall the motor 32 or to cooperate with a switch or other control device to terminate its motion when a predetermined maximum width limit is reached.
One of the outstanding advantages of the new apparatus is the ability of the operator to adjust the width of the spreader as an in-process adjustment, for optimum control over the finished width of the fabric. As will be appreciated, tubular knitted fabric is subject to a large number of variables in its construction and processing, so that there can be considerable variation even between supposedly similar fabrics, and it is not always possible to predict accurately the width at which a spreader frame should be set in order to achieve a desired finished width in the fabric. Utilizing the mechanisms of the invention, the spreader frame may be initially set to an approximate width, and the processing commenced. The operator is then able to observe the actual condition of the processed fabric and determine whether any further adjustment in width is required. If so, he is able to make precise adjustments in the fabric width by manipulating the edge drive roll carriages 27 slightly inward or slightly outward, as needed.
By appropriately locating controls for the edge drive carriages, it is possible for an operator to station himself at an appropriate process point for observation of the fabric while width adjustments are being made in the spreader frame. In the past, it has been necessary for the operator to stop the processing line and physically manipulate the spacer mechanism for the spreader frame, either by feeling through the wall of the fabric, or, in some cases, by actually cutting an opening in the fabric to gain access to the spacer adjusting mechanism. As will be readily appreciated, stoppage of the processing line under such circumstances for minor adjustment by the operator is inconvenient and so therefore the operator may be restrained from accomplishing this function.
With the apparatus of the invention, it is also possible to provide for continuous monitoring and automatic adjustment of the finished width of the fabric. For this purpose, a photocell or other sensing device 59 may be positioned adjacent to the windup station 36, or at some other appropriate stage of the process, in a position to sense the location of the fabric edge. If at any time the fabric edge wanders out of a predetermined tolerance range, the sensor 59 actuates a control circuit 60, energizing the motor 32 to either increase or decrease the spacing of the edge drive rolls 25, 26, as indicated by sensor 59.
In any of its forms, the apparatus of the invention represents a significant advance in the art of processing tubular knitted fabric involving spreading to width. In this respect, the processing of knitted fabric by various techniques, which include the step of spreading the fabric to flat form and predetermined width, is an old and well developed art. Nevertheless, it has been impracticable heretofore to make in-process width adjustments, because of the fact that the spreader frame is completely enclosed within the moving fabric tube. The mechanism of the present invention, utilizing a gas spring actuator, having relatively constant force throughout its full range of extension, enables the width of the spreader frame and hence the width of the processed fabric to be regulated and varied as an in-process adjustment, by controlling the position of the edge drive roll carriages 27. In a typical installation, a series of two or more self-adjustable spacer bar assemblies may be provided, adapted for quick interchange with the spreader frame sections, so that the proper range of width adjustment may be accommodated when setting up the equipment to handle a specific type and size of fabric.
Additional important advantages are derived from the invention by reason of the fact that the in-process width adjustment may be easily accomplished from a remote location, enabling the operator to make adjustments from a suitable observation point, such as the point at which the processed fabric is being gathered by winding, folding, etc. Additionally, the equipment lends itself to continuous, automatic edge-sensing of the finished fabric, such that automatic width adjustment of the spreader frame may be accomplished. This enables extremely uniform finished fabric to be produced with a minimum of operator attention and a maximum of efficiency in the overall processing operation.
In its several forms, the apparatus of the invention enables the spreader frame to be of very lightweight construction, yet adequately strong to withstand service in a commercial production line. Lightness of weight is important because the entire weight of the spreader frame assembly must be supported by the edge drive rolls, acting through the fabric wall, and excessive weight and/or pressure could mark sensitive fabrics.
It should be understood, of course, that the specific forms of the invention herein illustrated and described are intended to be representative only, as certain changes may be made therein without departing from the clear teachings of the disclosure. Accordingly, reference should be made to the following appended claims in determining the full scope of the invention. | The disclosure is directed to apparatus for processing of tubular knitted fabric, including an internal flat spreader and width-adjustable edge drives, typically used in connection with other processing apparatus, such as calenders, padding equipment, compressive shrinking stations, etc. The apparatus utilizes a pre-loaded, resiliently biased spreader frame which, within its operating limits, presses outwardly against adjustably movable, opposed edge drive rolls. The spreader frame, which is positioned internally of the moving fabric tube during processing operations, is capable of in-process width adjustments, without either stopping the processing line or damaging the fabric. Width adjustment of the internal spreader frame may be accomplished from a remote operator station. Moreover, the apparatus may incorporate edge-sensing means operative automatically to adjust the width of the spreader to maintain uniformity of width in the processed fabric. | 3 |
BACKGROUND
1. Field of the Invention
The invention relates generally to computing systems which multiply signed and unsigned binary numbers. The invention relates more specifically to digital computers which perform multiplication using a modified Booth algorithm.
2. Cross Reference to Related Patents
The following U.S. patent(s) is/are assigned to the assignee of the present application, is/are related to the present application and its/their disclosures is/are incorporated herein by reference:
(A) U.S. Pat. No. 3,840,727 issued Oct. 8, 1974 to Amdahl et al, and entitled, BINARY MULTIPLICATION BY ADDITION WITH NON-OVERLAPPING MULTIPLIER RECODING; and
(B) U.S. Pat. No. 4,761,756 issued Aug. 2, 1988 to Lee et al, and entitled, SIGNED MULTIPLIER WITH THREE PORT ADDER AND AUTOMATIC ADJUSTMENT FOR SIGNED OPERANDS.
3. Description of the Related Art
Digital computers can multiply binary numbers using a process equivalent to that used in the long hand multiplication of decimal digits.
In such a process, each bit (single digit) of the multiplier is taken by itself and applied against all the bits (digits) of the multiplicand to produce a corresponding partial product. Next, each partial product is shifted according to the power of its multiplier bit. And finally, all the shifted partial products are summed to form a complete product.
The long hand method is generally disadvantageous in computer applications because an undesirably large amount of computer circuitry and/or time is typically required to carry out multiplications involving large numbers.
As the number of bits in the multiplier and multiplicand increase, the number of partial products increase. The size of each partial product also increases. Consequently, the total number of bits to be processed in the partial product summation step increases.
Because some amount of computer circuitry and time is required for processing each bit of each partial product, the total amount of processing time and/or the overall size of the computer circuitry used to carry out multiplications by the long hand method tends to become disadvantageously large.
A number of techniques have been developed in the past for reducing this disadvantageous trend.
The Booth algorithm is a well known example. It reduces the number of partial products generated during multiplication and thereby reduces the total number of partial product bits.
The operation and advantage of the Booth algorithm can be best understood by way of a simple example.
Consider the multiplication of the number 5 (multiplicand) by the number 7 (multiplier). This may be represented in binary form as 101×111. Using the long hand approach, one moves right to left across the multiplier bits, and produces the following sum of partial products:
(101×001)+(101×010)+(101×100).
It is seen that three partial products are to be generated and summed together to produce the answer.
This of itself is not difficult to do with present day computer technology. One merely needs to provide three memory areas (registers), each with a storage capacity for storing one of the partial products, and to provide a serial or parallel adding unit for summing the contents of the memory areas either serially over time or simultaneously, in parallel.
Consider what happens, however, as the number of bits in the multiplier and multiplicand progressively increase by powers of two. (Consider 101010×111111 as a second problem.) The length of each partial product increases by the same scaling factor and the number of partial products increases by the same scaling factor. The amount of computer circuitry and/or computer time required for carrying out the multiplication using long hand approach increases correspondingly.
The Booth algorithm reduces the total number of partial products by taking advantage of a mathematical property which occurs whenever repetitive strings of ones are found within the multiplier.
Each continuous string of binary ones (e.g., 111) is replaced by the next highest power of two, less one. By way of example, 111=1000-1. In decimal terms this is expressed as 7=8-1.
For the first given example (5×7), the final product is obtained by summing the positive partial product (101×1000) with the negative partial product (101×-1). The number of partial product additions is reduced (from 3 to 2 in the present example) and a savings in computation time or circuit size is realized.
Many variations to the Booth algorithm have been devised over the years.
One common variation is referred to as the "three-bit modified Booth algorithm". The number of partial products created by this method is approximately (L M +1)/2 where L M is the number of bits in the multiplier.
The method is summarized with reference to the below TABLES 1 and 2. A dummy zero is appended to the right of the least significant bit in the multiplier and an encoding window is defined for processing the dummy appended multiplier, 3 bits at a time.
The window starts with the rightmost triplet of bits (the dummy plus bits 0 and 1 of the multiplier) and shifts left two positions for each iteration. One bit is shared between two successive iterations, serving as the leftmost window bit in a first iteration and the rightmost window bit in a second iteration. The bit position at the center of the window is considered the active bit position.
For each iteration, the encoding scheme of the below Table-1 is applied. C represents the multiplicand. Each output of the encoding scheme (C×m, where m=-2,-1,0,+1 or +2) is deposited in a successively lower row of a summation array with the rightmost bit of the output located in the active bit position of the encoding window.
For negative outputs, a ones complement of C is formed and a "hot carry" bit ("1") is added to an appropriate bit position of a next lower row of the summation array to thereby effectively form a two's complement of C. If the output is C×-2, the one's complement of C is also shifted left one position within its array row.
TABLE-1______________________________________WINDOW INPUTS OUTPUT______________________________________0 0 0 C × 00 0 1 C × 10 1 0 C × 10 1 1 C × 21 0 0 C × -21 0 1 C × -11 1 0 C × -11 1 1 C × 0______________________________________
Table-2 shows an example in which the decimal problem 5×12 is carried out by the 3-bit modified Booth algorithm. In Table-2, the binary form of the multiplicand (5), the multiplier (12) and part of the resulting summation array are shown in top to bottom order with bit position numbers 0 to 12 (C h in hexadecimal notation) and so forth being aligned vertically on top.
TABLE-2__________________________________________________________________________bit position: . . . C B A 9 8 7 6 5 4 3 2 1 0multiplicand: 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 1multiplier: x 0 0 0 0 0 0 0 0 0 0 0 0 1 1 0 0 (o)C × 0 → . . . . 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 pp1C × -1 → . . 1 1 1 1 1 1 1 1 1 1 1 1 1 0 1 0 pp2C × +1 → 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 1 (1) pp3. . 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 pp4. . . . . . . . . . . . . . . . . . .. . 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 0 0 sum__________________________________________________________________________
The multiplicand and multiplier fields are each 16 bits long here. Although not shown, it is to be understood that the length of the sum field (L S ) is equal to that of the multiplier (L M ) plus that of the multiplicand (L C ). So, L S =32 bits in the illustrated case. The sum field extends from the rightmost bit position 0 to the leftmost bit position 31 (1F h in hexadecimal notation).
The dummy zero is shown to the right of bit position 0 in the multiplier row. Partial product rows are respectively labelled pp1, pp2, pp3, etc
Let N represent the number of partial products. N is approximately equal to (L M 1)/2 which, in the above example becomes (16+1)/2=9.
If all the partial product rows, pp1, pp2, . . . , ppN had been written out in the above Table-2, it would be seen that the shape of the summation array turns out to be roughly trapezoidal (if one ignores the details of a staircase border at the right side of the array).
The top and bottom sides of the trapezoidal-shaped array are parallel to one another. The right side of the trapezoidal shape slopes to the left as one moves in the top to bottom direction. The left side of the trapezoidal shape extends vertically.
More specifically, the right side of each successive partial-product row (pp1, pp2, pp3, etc.) aligns two positions to the left of a previous row, thereby creating a leftward sloping staircase border at the right side of the trapezoidal shape. The left side of each successive partial-product row (pp1, pp2, pp3, etc.) extends to and aligns vertically with the leftmost bit position of the total sum field (position 31) because sign-extension bits have to be provided in each row to take care of carry bits, as will be explained in more detail shortly.
The top side of the trapezoid is equal in length to that of the sum field (L S ) located just below the base of the trapezoid. The base of the trapezoid is roughly half as long as the sum field.
The height of the trapezoidal shape is equal to N, which is the total number of rows (pp1, pp2, . . . , ppN) in the summation array. As explained earlier, N is approximately equal to one-half the number of bits in the multiplier plus one divided by two (N≃[L M +1]/2). N can vary slightly around this norm depending on the modulo-3 value of the multiplier bit length, L M .
For L M =L C =L S /2, the total number of bits in the created when the encoding window covers the dummy zero (c) plus multiplier bit positions 0 and 1. The value of the encoding output, C×0 is written across partial product row pp1 with the least significant bit aligned most significant bit of the C×0 encoding output is written into bit position 15 (F h in hex notation) of row pp1. However, because the sum line is 32 bits long, a string of sixteen "sign-extension" bits have to be further written into bit positions 16-31 of row pp1.
The encoding output written into the next lower row, pp2, is C×-1 since the window covers multiplier bits 3, 2 and 1 (input pattern 110) for that row. To form a negative version of C, the ones complement of C is written across the pp2 row with the hot carry set in bit position 2 of next lower row pp3 as indicated by the symbol "(1)".
Note that the value, C×-1 can be written across just sixteen bit positions (2 through 17) of row pp2, but sign extension bits have to be filled in across the of row pp2, from bit position 18 through bit position 31.
Row pp3 is further filled with C×1 as the 3-bit encoding window covers bit positions 5, 4 and 3 (input pattern 001).
For remaining operations of the encoding window on the more leftward parts of the multiplier (00. . . 01100), the output is always zero as illustrated in the fourth row, pp4, and indicated to continue into the remaining rows (pp5, pp6,. . . , ppN) below it.
It is to be noted that although the length L C of the multiplicand, C, is only 16 bits, and its corresponding partial product C×m is therefore only 16 or 17 bits long (depending on whether m is a +/-2 or not), the sign extension bits have to be replicated from the leftmost position of each partial product C×m (where m=-2, -1,0,1, or 2), to the leftmost bit position of the sum field (bit position 31) to assure that proper summation takes place.
The sign extension bits are all ones ("111. . . ") if the C×m output is negative and all zeroes ("000. . . ") if the C×m output is positive.
A variety of software and/or hardware techniques may be used for writing all the sign extension bits into the sign-extension bit positions of each row, pp1, pp2, . . . , ppN. A variety of software or hardware techniques may also be used for carrying out the partial product generation and summation operations of the modified Booth algorithm. Partial product summation can be carried out either as one massively parallel operation or as a few less massively-parallel operations or as a sequential series of smaller operations whose final effect is to produce the sum field (the complete product).
Regardless of the technique chosen (software versus hardware, parallel versus serial), a common problem develops as one attempts to scale upwardly from 16-bit by 16-bit multiplication operations, to 32×32 bit operations, to 64×64 operations, and so forth.
The amount of circuitry and/or time needed for writing the sign-extension bits into each row grows with scaling. The overall size of the summation array (pp1, . . . , ppN) grows in both height and width at a rate proportional to the scaling factor. The cost for preparing the sign extension bits and processing the numbers within the summation array, as measured in terms of either hardware resources (e.g., number of logic gates) or time for completion, grows in proportion to the area of the summation array.
Since area is a function of height times width, and these parameters respectively grow in rough proportion to the number of bits in the multiplier, costs increase as the square of the multiplier field length.
More specifically, for the case where there are L M bits in each of the multiplier and multiplicand, the area of the trapezoidal-shaped summation array is approximately 0.75 times (L M 2 +L M ) and the cost for implementing such an array is proportional to this scaling factor.
Despite the speed and circuit size savings obtained from use of the 3-bit modified Booth algorithm, hardware and/or software costs nonetheless become prohibitively large as one tries to construct multipliers with larger and larger multiplier fields. A method for further reducing costs is needed.
SUMMARY OF THE INVENTION
The invention reduces the above-mentioned problem by providing an improved method and apparatus for processing the sign-extension bits of partial-products generated by the modified Booth algorithm or like algorithms which generate signed partial products.
Rather than extending the left side of each partial product row to align with the leftmost bit position of the sum field (e.g., the full product field), the length of each partial product row is preferably held equal to that of the multiplicand (not counting one additional left-side bit position for handling times-two operations and a further right-side bit position for handling hot carries if needed). A special sign-extension "correction" row of the same length is introduced at the bottom of the resulting, parallelogram-shaped, summation array for generating a correction factor which mimics the effect of summing the sign-extension bits in the eliminated portions of each of the partial product rows.
The special correction row contains fewer bits than the total number of bits contained in all the eliminated sign extension portions, and accordingly, less computer circuitry and/or computer time is required for performing the partial product summation operation.
More importantly, the size of the computer circuitry and/or the amount of time needed for generating the correction row can be made smaller than that needed for summing the eliminated sign extension fields. An overall improvement in cost versus performance is obtained.
A fast and simple apparatus or method for generating the correction row is disclosed below.
BRIEF DESCRIPTION OF THE DRAWINGS
The below detailed description makes reference to the accompanying drawings, in which:
FIG. 1 is a block diagram showing how the area of a partial product summation array is reduced in accordance with the invention.
FIG. 2 is a schematic diagram of a first correction row encoder in accordance with the invention.
FIG. 3 is a block diagram of a parallel multiplier circuit in accordance with the invention.
FIG. 4 is a schematic diagram illustrating a circuit for generating the bits of a sign-correction row rr(N+1) for a 3-bit modified Booth algorithm in accordance with the invention.
DETAILED DESCRIPTION
In the explanation below, the part of each prior art partial product row which was not filled with sign extension bits will be called the "nonextension subfield" and the other part which was filled with extension bits will be called the "sign-extension subfield". The most significant bit of each nonextension subfield is referred to as the sign bit of the partial product.
FIG. 1 shows a multiplication system 100 in accordance with invention. Elements within system 100 are referenced by numbers in the "100"series. A "ghost" section comprising non-existing elements 6, 10 and 30 is additionally shown to illustrate the savings over prior art multiplying schemes.
In the illustrated system 100, a multiplicand register 102 of length L C and a multiplier register 104 of length L M =L C supply respective multiplicand (C) and multiplier (M) bits to a partial product encoder 106.
Encoder 106 receives the values held in registers 102 and 104, and in response, outputs partial product bits to fill summation array 120.
Summation array 120 consists of N register rows each having capacity for storing at least L C bits. The register rows of array 120 are respectively labelled rr1 through rrN.
In one embodiment, encoder 106 encodes partial products according to a 3-bit modified Booth algorithm. In another, less preferred embodiment, encoder 106 encodes partial products according to the long hand method.
Of importance, partial product encoder 106 does not generate sign extension subfields. The nongenerated sign extension subfields are represented by horizontal series of lower case e's in ghost triangular area 10. Each ghost subfield, eee . . . eee, corresponds to one of the partial products stored in summation array 120. The nonexistent circuitry or computer time that would have been used for generating the ghost subfields of area 10 is represented by a ghost sign-generator 6.
A correction-row encoder 130 receives some of the outputs from the partial product encoder 106 and generates bits for a sign correction row 140 which is appended to the summation array 120, as shown. The bits in the correction row 140 are equivalent to the sum of the bits in the ghost sign-extension area 10 as indicated by ghost adder 30.
Of importance, the circuitry for implementing correction encoder 130 and correction row 140 is smaller in size and/or faster in speed than the sign-generating means 6 that would have been needed to generate the sign extension bits of ghost area 10 and the storage circuitry 10 that would have been needed to store those bits and the summing means 30 that would have been needed to sum the contents of ghost area 10.
Summing means 150 sums only the bits of array 120 and of correction row 140 to produce a complete product.
The overall multiplication system 100 is smaller in size and/or faster in speed than would have been possible with the conventional approach because summing means 150 does not include ghost summing means 30, because correction row 140 stores less bits than ghost area 10, because encoder means 106 does not include generator means 6, and because encoder means 130 is relatively simple, as will be seen shortly.
Basic to the invention is a realization that the sign-extension subfields in the prior art summation array, when taken as a whole, have the over-all shape of a right triangle as denoted by the "ghost" triangle 10 in FIG. 1. The right edge 11 of the ghost triangle 10 slopes to the left by at least one bit position per row as one moves down the rows rr1, rr2, . . . , rrN of the adjacent summary array 120.
A special arithmetic is developed below to take advantage of this geometric characteristic. A correction row which is equivalent to the sum of the sign-extension subfields in the ghost triangle 10 is generated using a relatively simple hardware and/or software means 130.
The correction row 140 is substituted for the previous sign-extension subfields of the ghost triangle 10 and a corresponding saving in circuit size and/or processing time is realized within the summing means 150 which processes the data.
It is easiest to appreciate the invention by developing it out of series of simple modifications.
Consider first the two rows of binary coded numbers which are illustrated in the below DIAGRAM-1. The rows are referenced as rows rr1 and rr2. The numbers in rows rr1 and rr2 are to be summed together to produce a total value in a total row, rrT placed below a bottom line. ##STR1##
The second row, rr2, contains a negative number whose nonextension bits are denoted by NNN . . . NNN and a sign-extension subfield whose bits are denoted by eee . . . eee. It is understood that the sign bit (the leftmost "N") in the nonextension subfield is a "1" and the bits of the sign-extension subfield (eee . . . eee) are also ones.
The upper row, rr1, contains a positive number whose nonextension bits are denoted by PPP . . . PPP. There is no sign extension subfield for the upper row, rr1.
The string of lower-case s's placed below the bottom line represent the sum of the numbers in rows rr1 and rr2. The sum sss . . . sss can be positive or negative, depending on the relative magnitudes of the numbers in rows rr1 and rr2.
Consider first what happens if the absolute value of the negative number in row rr2 is less than the magnitude of the positive number in row rr1. The result in total row rrT will be positive as illustrated in the below DIAGRAM-2. ##STR2##
The sign extension subfield of row rr2 is now shown in more detail as consisting of all ones (111 . . . 111). The sign bit in the nonextension subfield of row rr2 is still shown as "N" to differentiate it from the "1's" of the sign-extension subfield. The bit positions in total row rrT which correspond to the sign-extension bits of row rr2 are all zeroes (000 . . . 000).
How do the sign extension bits of total row rrT become all zeroes when the bits in the sigh-extension subfield of second row rr2 are all ones? The answer is that a carry bit equal to one, (c)=1, develops in the bit position just to the left of the nonextension subfields when the subfields, (PPP . . . PPP) and (NNN . . . NNN) are summed together.
This carry bit (c) can be visualized as dropping onto the rightmost "1" bit in the sign extension subfield of row rr2, and in so doing, initiating two simultaneous functions. It erases the string of "1's" by carry propagation and thus blocks the sign-extension subfield of row rr2 from dropping down to the bottom line, rrT. It also annihilates itself by combining with the rightmost one of the sign extension subfield and thereby blocks its own value (c=1) from dropping down to the bottom line, rrT.
Suppose for a moment that the sign extension subfield of row rr2 were to be removed from DIAGRAM-2. The carry bit (c) would drop into the sum field sss . . . sss and produce an erroneous result.
With the sign extension subfield present in row rr2, however, the ensuing carry propagation sweeps the carry bit (c) leftward, away from the sum field sss . . . sss and into oblivion. The sign extension subfield thus functions to block the carry bit (c) from erroneously dropping down to the bottom line.
Now consider what happens when the absolute value of the negative number in row rr2 is greater than the magnitude of the positive number in row rr1. The result in total row rrT is negative as illustrated in the below DIAGRAM-3. ##STR3##
The sign extension subfield of row rr2 is again shown as consisting of all ones (111 . . . 111). The corresponding bit positions in the total row, rrT, are now also all ones (111 . . . 111).
This happens because the sum of the nonextension subfields, (PPP . . . PPP) and (NNN . . . NNN), fails to produce a carry bit as indicated by the empty parentheses to the left of and above first row rr1 of DIAGRAM-3. All the ones of the sign extension subfield in row rr2 drop down into the bottom line to thereby define a negative result.
Next, consider a modified summation array as illustrated in below DIAGRAM-4. ##STR4##
The sign-extension subfield (eee . . . eee) of second row rr2 has been eliminated and a new "sign-correction" row rr(N+1) has been inserted. It is positioned below rows rr1 and rr2 but above the bottom line.
The bits of the sign-correction row rr(N+1) are all ones (111 . . . 111), and therefore substitute for the eliminated sign-extension subfield (eee . . . eee) of the second row rr2. The blank positions at the right side of the sign-correction row rr(N+1) do not contribute to the bottom line sum (sss . . . sss).
The sum (sss . . . sss) that is obtained from summing the three rows, rr1, rr2 and rr(N+1) of DIAGRAM-4, is, of course, equivalent to the result obtained from summing rows rr1 and rr2 in either DIAGRAM-2 or DIAGRAM-3.
When the sum of the nonextension subfields (PPP . . . PPP) and (NNN . . . NNN) in rows rr1 and rr2 of DIAGRAM-4 produce a carry bit, the carry bit will annihilate the ones in the sign-correction row rr(N+1) and the ones in the sign-correction row rr(N+1) will correspondingly annihilate the carry bit so that a positive result drops down to the total row, rrT. If the sum of the nonextension subfields (PPP . . . PPP) and (NNN . . . NNN) in rows rr1 and rr2 do not produce a carry bit, the ones of the sign-correction row rr(N+1) will drop down to the total row, rrT, thereby defining a negative result.
From a purely mathematical standpoint, DIAGRAM-4 is equivalent to DIAGRAMS 1-3. From the viewpoint of physical circuitry, however, DIAGRAM-4 suggests a rather unusual concept.
The memory area (or register or bus or combinatorial logic unit) which stores or carries the negative number (NNN . . . NNN) is reduced in size (width) because it no longer supports the sign extension bits for that number NNN . . . NNN. A separate memory area (or register or bus or combinatorial logic unit) is at the same time added to store (or propagate) a correction factor whose contents are applicable to the entire summation array (to rows rr1 and rr2).
With this in mind, we advance to a next modification, and insert a new row, rr3, between rows rr2 and rr(N+1), as shown in the below DIAGRAM-5. ##STR5##
The sign-extension subfield (eee . . . eee) of the newly added, third row rr3 is not defined yet as being either all ones or all zeroes. Of importance, however, the rightmost bit of the new sign extension subfield (eee . . . eee) is positioned at least one bit position to the left of the corresponding rightmost bit in the eliminated sign-extension subfield previously associated with row rr2. The nonextension subfield of third row rr3 is denoted by a series of X's to indicate that it could represent either a positive or negative number.
Assume that the third row rr3 contains a negative number. If we eliminate the sign-extension subfield (eee . . . eee) of row rr3 and add a corresponding set of ones to the sign-correction row rr(N+1), the result will appear as shown in DIAGRAM-6. ##STR6##
Note that the second to right bit position of the sign-correction subfield has been toggled to the zero
This is in accordance with a simple rule of binary addition. As seen in the below DIAGRAM-7, whenever two strings of all ones are added, the rightmost "1" in the leftward indexed extension subfield toggles the corresponding bit in the sum row while leaving the remaining bits of the sum row as all ones. ##STR7## Going back to DIAGRAM-5, if we assume that the newly inserted third row rr3 contains a positive number, the contribution to the sign-correction row rr(N+1) from the third row rr3 will be all zeroes and the second from the right bit of the sign-correction subfield will remain as a one ("1") in such a case.
Let us assume for our next modification that the third row rr3 definitely contains a positive number and that we now wish to expand the summation array by inserting yet a fourth row rr4 as shown in the below DIAGRAM-8. ##STR8##
As was the case with our previous expansion, the sign-extension subfield (eee . . . eee) of the newly added fourth row rr4 is not defined yet to be either all ones or all zeroes. But of importance, the rightmost bit of the new subfield (eee . . . eee) is positioned at least one bit position to the left of the corresponding rightmost bit in the eliminated sign-extension subfield previously associated with the third row rr3. The nonextension subfield of row rr4 is denoted by a series of X's to indicate that it could represent either a positive or a negative number.
Let us now assume that the fourth row rr4 contains a negative number. If we eliminate the sign-extension subfield (eee . . . eee) of row rr4 and add a corresponding set of ones to the sign-correction row rr(N+1), the result will appear as shown in DIAGRAM-9. ##STR9##
Note that a zero has been inserted into the third from the right bit position of the sign-correction subfield rr(N+1). If third row rr3 of above DIAGRAM-9 had also contained a negative number (instead of a positive number), the result in the sign-correction row rr(N+1) would have been 1111111001. That is, zeroes would have been overwritten into the bit positions of correction row rr(N+1) that correspond to rows rr3 and rr4.
Strangely, the rightmost bit of rr(N+1) contains a "1" even though its corresponding partial product rr2 is negative.
If we were to discount this strange phenomenon and we continued the above sequence by adding rows of rr5 through rrN, a simple method for generating the sign-correction row rr(N+1) would begin to reveal itself. Simply toggle the corresponding "one" in the correction row for each corresponding negative number.
But, there is that troublesome exception at the right end of row rr(N+1). One additional step is called for to better understand what is going on here. Add a zero bit ("0") to the right of the rightmost one bit in row rr(N+1) and assign that zero bit as corresponding to the positive number (PPP . . . PPP) in row rr1. The following "1" bit of row rr(N+1) then corresponds to row rr2, the third from the right bit corresponds to row rr3, and so on.
We can then present the following rule. For any summation array having partial product rows rr1 through rrN, where the left end of each nonextension subfield successively indexes one bit position to the left of a previous row, the correction-row generating method comprises the steps of:
(1) Point to the topmost row, rr1, of the summation array and to the rightmost bit position of the sign-correction row, rr(N+1);
(2) Does the pointed-to row contain a negative number? If the answer is yes, proceed to step number (5). If the answer is NO, write a zero into the pointed-to bit position of the sign-correction row rr(N+1);
(3) Point to the next partial product row and also point to the next bit position of the sign-correction row, rr(N+1);
(4) Repeat step numbers (2) and (3) either until the answer is yes or until there are no more partial product rows.
(5) Write a one into the sign-correction row rr(N+1) bit position corresponding to the first found partial product row having a negative number and proceed to step number (6).
(6) Point to the next partial product row. Point to the next bit position of the sign-correction row, rr(N+1). Does the pointed-to row contain a negative number? If YES, write a zero into the pointed-to bit position of the sign-correction row rr(N+1); otherwise write a one into the same bit position. Repeat this step number (6) until there are no more partial product rows.
As seen from the above method, the right side bits of the correction row remain zero for each of the corresponding positive numbers in the upper rows as long as there are no negative partial products in the corresponding upper rows of the summation array. The first negative number gets a one ("1") in its corresponding bit position of the correction row. Thereafter, the rule is inverted. Each negative number gets a zero ("0") and each positive number gets a one ("1").
Another way of looking at the same phenomenon is to stand in the position of each bit in the sign-correction row rr(N+1) and to look up to the overlaying partial product rows. We can then define the following process:
(1) For each correction bit CB(i); in row rr(N+1), point to its corresponding row, rr(i), in the summation array.
(2) Does the pointed-to row rr(i) or any row rr(i-j) above it (for j equal 1 to i-1) contain a negative number? If NO, set CB(i) equal to zero.
(3) Does the pointed-to row rr(i) contain a negative number while all other rows rr(i-j) above it contain positive numbers? If YES, set CB(i) equal to one.
(4) Does the pointed-to row rr(i) contain a negative number while one or more rows rr(i-j) above it also contain negative numbers? If YES, set CB(i) equal to zero.
(5) Does the pointed-to row rr(i) contain a positive number while one or more rows rr(i-j) above it contains a negative number? If YES, set CB(i) equal to one.
The above rules can be converted into a truth table as shown in below DIAGRAM-10. Input logic values are shown in columns A and B. Output logic values are shown in column C.
______________________________________DIAGRAM-10INPUTS OUTPUTA B CSr(i) = Does Sr(j) = 1 Correspondingsign bit of in any row rr(j) Correction Bitrow rr(i) above row rr(i) ? CB(i)______________________________________0 0 0 (rule 2)0 1 1 (rule 5)1 0 1 (rule 3)1 1 0 (rule 4)______________________________________
Note that for the case of (i)=1, there are no situations where the answer to the column-B question, Sr(j)=1 ? is true because there are no rows above row(i=1). Therefore, for the case of (i)=1, input conditions AB=01 and AB=11 of the above truth table are don't-care conditions; they never happen. The truth table reduces to one having just the input conditions AB=00 and AB=10 for this special case.
FIG. 2 is a schematic of a simple encoder circuit 230 which may be used for carrying out the input/output translation defined by DIAGRAM-10.
Sr1 represents the leftmost "sign bit" of row rr1. Sr2 is the sign bit of row rr2, and so on. SrN, therefore represents the leftmost "sign bit" of row rrN.
Correction bit CB(1) is simply a copy of Sr1, as indicated at 231. This can be done because of the above-mentioned don't-care condition for the case of (i)=1.
For the case of correction bit CB(2), an exclusive OR of the two left input columns, A and B, in above DIAGRAM 10 produces the result shown in output column-C. A simple XOR gate generates correction bit CB(2) as shown at 232.
For the case of CB(i) where i>2, the answer to the question of column-B is produced by ORring together the sign bits of previous rows, as indicated, for example, at 233b, 234b and 23Nb. Then, the result in column-C is produced by exclusive-ORring the column B answer with the sign bit for the current row (i) as indicated, for example, at 233a, 234a and 23Na.
The general case encoder circuit for producing correction bit CB(N) is shown to comprise OR gate 23Nb which receives as its inputs, Sr1, Sr2, . . . , Sr(N-1). The output of OR gate 23Nb drives a first input of XOR gate 23Na while the second input of the XOR gate receives sign bit SrN. An advantage of having separate OR gates 233b, 234b, 23Nb for producing each column-b answer is that the corresponding bits CB(3), CB(4), CB(N) of the correction row are all generated in parallel and this speeds the overall production of not only the correction row bits, but also the final product (the output of summing means 150 in FIG. 1).
With the above principles in mind, we need to take a closer look at the structure of the summation array created by a 3-bit modified Booth algorithm. The general structure is illustrated in below DIAGRAM 11.
__________________________________________________________________________DIAGRAM-11__________________________________________________________________________Alt BP ID: 5 4 3 2 1 b a b a b a b a b a | | . . | | . . | | . . . . . . . . . .Bit Position: I H G F E D C B A 9 8 7 6 5 4 3 2 1 0 .ROW NAME . . . . . . . . . . . . . . . . . . . .C × +1 → . . . . . . . . . . P P P P P P P P P . pp1C × -1 → . . . . . . . . N N N N N N N N N . . . pp2C × +1 → . . . . . . P P P P P P P P P . . . . . pp3C × -2 → . . . N N N N N N N N N O . . . . . . . pp4C × +1 → . . P P P P P P P P P . . . . . . . . . pp5EE1 → 0 0 0 0 0 0 0 0 0 0 . . . . . . . . . .EE2 → 1 1 1 1 1 1 1 1 . . . . . . . . . . . .EE3 → 0 0 0 0 0 0 . . . . . . . . . . . . . .EE4 → 1 1 1 0 . . . . . . . . . . . . . . . .EE5 → 0 0 . . . . . . . . . . . . . . . . . .__________________________________________________________________________
The topmost two rows are referenced as "alternate bit positions identifiers" (Alt BP ID) for reasons that will become apparent shortly. The corresponding, more traditional bit position designations: 0, 1, 2, . . . , 9 and A, B, . . . , F are shown two rows lower with positions to the left of hexadecimal F, being labelled G, H and I for convenience sake.
Shown below this are the bits of the partial product rows, pp1, pp2, pp3, pp4 and pp5.
The Booth algorithm operations which generate the bits of rows pp1, pp2, etc., are respectively illustrated as C×+1→, C×-1→, and so on at the left side of each partial product row. The bits within each nonextension subfield (with the exception of the rightmost bit in row pp4) are respectively designated as P or N depending on whether a positive or negative result is produced by the corresponding Booth operation, C×m(i), where m(i) is the effective multiplier for row pp(i).
Unlike previous diagrams in which the sign extension contributions from all the partial product rows were compressed into a single correction row, the sign extension subfields from partial product rows pp1, pp2, pp5 are initially shown shifted down to respective rows EE1, EE2, . . . , EE5. This layout will help explain the arithmetic behind the addition of the EE rows with more clarity. A zero is padded to the right of sign-extension subfield EE4 for reasons that will become apparent shortly.
Ultimately, rows EE1 through EE5 are summed to produce a single sign-correction row rr(N+1). Note, however, that to generate such a correction row, each of rows EE1 through EE5 contributes its rightmost two bits to a corresponding pair of bit positions in the correction row.
The rightmost two bits, "00", of row EE1 drop down along the columns of bit positions A and 9 to define the corresponding bit positions A and 9 of the correction row. The rightmost two bits, "11", of row EE2 drop down along bit positions C and B. The rightmost two bits, "00", of row EE3 drop down along the columns of bit positions E and D. The rightmost two bits, "10", of row EE4 drop down along bit positions G and F. The rightmost two bits, "00", of row EE5 drop down along the columns of bit positions I and H.
This occurs because the window of the three-bit modified Booth algorithm shifts by two places on every iteration and thereby shifts the right end of each successive partial product C×m(i) two bit positions to the left of the preceding partial product.
Note, however, that in row pp4 the multiplier m(4) is equal to minus two (-2). This shifts the left end of the nonextension subfield (NNNNNNNNN0) one additional position to the left (into bit position F rather than E) and leaves a zero in bit position 6.
Consequently, the rightmost logic one ("1") of row EE4 is positioned within the left-handed one of corresponding bit positions G and F. At the same time, the rightmost logic one ("1") of row EE2 is positioned in the right-handed one of its corresponding bit positions C and B because its corresponding multiplier, m(2), is equal to minus one (-1).
It is advantageous to switch now to the nomenclature of the alternate BP identifiers.
Bit position 9 is alternatively referred to as bit
position (1a). Bit position A is alternatively referred to as bit position (1b). Bit position B is alternatively referred to as bit position (2a). Bit position C is alternatively referred to as bit position (2b). And so on.
Generally speaking, for the case where a negative partial product, (NNNNNNNNN) or (NNNNNNNNN0), arises in a given row pp(i), the rightmost logic one ("1") of the corresponding sign extension subfield row EE(i) will reside either in the left-handed one or right-handed one of alternate bit positions (ib) and (ia) depending on whether the "m(i)" factor in the Booth operation, C×m(i), was a -2 or a -1.
The earlier discussed "toggling effect" which begins in the sign-correction row rr(N+1) after the first negative partial product is encountered, and which is attributed to the "rightmost" logic one ("1") of each negative sign extension subfield, correspondingly shifts into either bit position (ib) or (ia) depending on the value of multiplying factor "m(i)".
Note that multiplying factor "m(i)" cannot be simultaneously equal to -1 or -2 for any given row number, i. These are mutually exclusive states.
Note further that when multiplying factor "m(i)" is equal to either -1 or -2, it cannot be simultaneously equal to 0, or +1 or +2. These are also mutually exclusive conditions for any given row number, i.
In the below DIAGRAM-12, the case of "m(i)" being equal to 0, or +1 or +2 is referred to as a "Class-A condition". The case of "m(i)" being equal to -1 is referred to as a "Class-B condition". The case of "m(i)" being equal to -2 is referred to as a "Class-C condition".
______________________________________DIAGRAM-12INPUTSAA BB OUTPUTSMutually Does m(j) CCExclusive of any row pp(j) CorrespondingClasses above row pp(i) Correctionof each belong to Class-B Bitsm(i) or to Class-C? CB(ib) CB(ia)______________________________________A m(i) = 0 0 0 0 or 1 1 1 +1 or +2B m(i) = 0 1 1 -1 1 1 0C m(i) = 0 1 0 -2 1 0 1______________________________________ respectively referenced as "AA", "BB" and "CC". Note that for the case of (i)=1, there are no situations where the answer to the column-BB question, m(j) not in Class-C? is always true. This is because there are no rows above row(i=1). Therefore, for the case of (i)=1, the above DIAGRAM-12 reduces to one where rows satisfying BB=1 are stripped out.
Comparing DIAGRAM-11 with DIAGRAM-12, it is seen that rows pp1 and EE1 are examples satisfying AA=Class-A and BB=0. The two rightmost bits contributed from row EE1 are therefore CB(ib), CB(ia)=00.
Referring to rows pp2 and EE2 of DIAGRAM-11, it is seen that this is an example of AA=Class-B and BB=0. It is the first time that a negative partial product appears and the multiplier is minus one, therefore the correction contribution is 11.
If the multiplier factor, m(2) for column pp2 had been a minus two instead of a minus one, the contributed bits would have been, as shown for the case of AA=Class-C and BB=0. The contributed correction bits would have been 10.
Referring to row pp3 of DIAGRAM-11, this is an occurrence of a positive partial product coming after the occurrence of a negative partial product. The corresponding sections of DIAGRAM-12 are AA=Class-A and BB=1. The rightmost two zero bits of row EE3 do not toggle the contributions from row EE2, and therefore the resulting correction row bits are 11.
Referring to row pp4 of DIAGRAM-11, this is an example of a second-occurring negative partial product. The logic one ("1") at bit position (4b) of row EE4 toggles the logic one ("1") of row EE2, bit position (4b), and therefore the corresponding correction bits of positions (4b) and (4a) will be 01, as shown in DIAGRAM12, at AA=Class-C for the case of BB=1.
If the multiplying factor, m(4) of row pp4 had been a minus one instead of a minus two, the rightmost logic one ("1") of row EE4 would have been located at bit position (4a) and the corresponding correction bits would have been 10. This is shown in DIAGRAM-12, for the case of AA=Class-B and BB=1.
FIG. 4 illustrates a gate-level schematic of a circuit which carries out the logic operations of DIAGRAM-12. This correction encoder 330 is designed for use within a parallel Booth-algorithm multiplying circuit 300 shown in FIG. 3.
Referring first to FIG. 3, the overall design of the parallel multiplying circuit 300 will be described.
Multiplicand register 302 stores a multiplicand value with as many as fifty-six bits. Multiplier register 304, likewise stores a multiplier value with as many as fifty-six bits. Window encoders 306.1, 306.2, . . . , 306.29 respectively receive triplets of bits 0-55 from multiplier register 304 and encode them in accordance with the three-bit modified booth algorithm. Each window encoder 306.x outputs a corresponding five-bit multiplier value m(x) to indicate whether the multiplicand in register 302 should be correspondingly multiplied by +2, +1, 0, -1 or -2. The five lines for multiplier bus m1 are illustrated and understood to be similarly repeated for multiplier buses m2, m3 . . . , m29.
Each m(x) bus (x=1, 2, 3, . . . 29) feeds into a corresponding C-encoder unit 307.x as shown. The fifty-six bit wide multiplicand value from register 302 is also input into all the C-encoders 307.1-307.29.
Each C-encoder unit 307.x outputs a fifty-seven bit corresponding value C×m(x) to a Wallace tree circuit 350. The last C-encoder unit 307.29 needs no more than fifty-six bits to represent its output C×m(29). Because of the peculiar way in which the window of the three-bit modified Booth-algorithm aligns with the fifty-six-bit multiplicand of register 302, the absolute value of multiplying factor m(29) is never greater than one. Thus, output bus C×m(29) of encoder 307.29 needs only fifty-six wires.
The Wallace tree circuit 350 is well known and does not need to be described in detail here. Briefly, a Wallace tree circuit 350 may be described as having a plurality of layers which successively reduce the number of bits to be added using a three-to-two compression algorithm in each layer.
Each of the m(x) busses also feeds into extension bit correction encoder 330, as shown. The correction row encoder 330 generates its own fifty-six bit wide correction factor CB(1a:28a, 1b:28b) which is also input into the Wallace tree circuit 350.
Referring to FIG. 4, the internal circuit of the correction row encoder 330 will now be described in greater detail.
As already mentioned, for the case of (i)=1, the rows of DIAGRAM-12 corresponding to BB=1 can be stripped out. When this is done, it is seen that correction bit CB(1a) is at logic one ("1") only in the row of Class-B, or put another way, only when multiplying factor m(1)=-1. Thus, correction bit CB(1a) is simply a copy of the logic level appearing on the -1 line of bus m(1) (see FIG. 3). This is shown at 431a of FIG. 4.
Correction bit CB(1b) is at logic one in the Class-B and Class-C rows of the reduced DIAGRAM-12. As seen in FIG. 4, correction bit CB(1b) is generated by an exclusive-OR gate (XOR) 431b. XOR gate 431b receives logic levels representing the truth of the respective propositions, m(1)=-2 and m(1)=-1. Since Class-B and could be replaced by a simple OR gate if desired.
For the case where (i) is greater than one, the full logic of DIAGRAM-12 has to be implemented.
Consider first the output row labeled CB(ia). For Class-A and Class-C, the output CB(ia) is simply a copy of the bits in column BB. For Class-B, the output term CB(ia) are the inverse of the corresponding bits in column BB.
Thus, for the case of (i)=2, OR gate 452a generates the bits of column BB by ORring together all m(j) terms where j is less than i. Exclusive-OR gate (XOR) 432a inverts the result produced by OR gate 452a if m(2)=-1 is true.
Consider next, the output column labelled CB(ib) in DIAGRAM-12. For the case of Class-A, CB(ib) is simply a copy of the bits in column BB. For the case of Class-B, the output correction bit CB(ib) is always logic one regardless of what bits appear in column BB. For the case of Class-C, the output bit CB(ib) is the inverse of the bits appearing in column BB.
Referring to the gates 432b and 452b, it is seen that these generate correction bit CB(2b) in FIG. 4. Assume first that the proposition m(2)=-1 is false. We only have to deal with the conditions of Class-A and Class-C. OR gate 452b generates the bits of column BB (as long as our assumption stands) and exclusive-OR gate (XOR) 432b inverts the result for the case of Class-C.
So what happens for the case of Class-B? Recall that Class-B is mutually exclusive of Class-A and Class-C for any given value of i. For the case of i=2, our assumption regarding the falsehood of m(2)=-1 is correct if m(2) resides in either of Class-A or Class-C. When m(2) resides in Class-B, the value of m(2)=-2 is false by definition (because Class-C is mutually exclusive of Class-B). Accordingly, for the case of m(2)=-1 being true, that true bit passes through OR gate 452a and through XOR gate 432a to hold CB(2a) at logic one ("1") irrespective of the value of BB.
The circuitry for generating correction bit CB(3a) is shown to comprise OR gate 453a and XOR gate 433a. OR gate 453a receives as its inputs the logic levels on lines: m(2)=-2, m(2)=-1, m(1)=-2, and m(1)=-1. XOR gate 433a receives as its inputs, the output of OR gate 453a and the logic level on line m(3)=-1.
The fifty-sixth bit generated by encoder 330 is CB(28b) As seen, OR gate 45(N-1)b collects the logic levels of lines m(1)=-1, m(1)=-2, . . . , m(28)=-1. XOR gate 43(N)b receives as its inputs, the output of OR gate 45(N-1)b and the logic level on line m(28)=-2.
Since correction bits CB(1a) through CB(28b) are all generated in parallel from the signals generated on buses m1 through m28 (see FIG. 3), the output from correction encoder 330 becomes valid for processing by the Wallace tree circuit 350 at the same time that the outputs from the C-encoders 307.1-307.29 become valid. This advantageously quickens the speed at which multiplying circuit 300 produces results. Naturally, if speed is not of the essence, the parallel architecture shown in FIG. 3 could be converted partly or wholly into one of a serial nature while still complying with the truth table set forth in DIAGRAM-12. (Note with respect to FIG. 3, that in this particular implementation, the E encoder 330 does not need to receive the m(29) bus since there is no CB (29a) or CB(29b). The E encoder 330 receives only m1-m28.)
The above disclosure is to be taken as illustrative of the invention, not as limiting its scope or spirit. Numerous modifications and variations will become apparent to those skilled in the art after studying the above disclosure.
By way of example, the invention is not limited to systems which carry out long-hand multiplication or multiplication in accordance with the 3-bit modified Booth algorithm. All computational circuits which add signed partial products can benefit. The invention is not limited to circuits which carry out computations in a massively parallel fashion. Serial implementations are equally contemplated. The correction row encoding step does not have to be carried out in hardware. The logic OR and XOR operations of the correction row generating algorithm are simple enough to be quickly carried out in software.
Given the above disclosure of general concepts and specific embodiments, the scope of protection sought is to be defined by the following claims. | A method and apparatus for adding signed partial products without generating sign extension subfields is disclosed. The method and apparatus are particularly useful when employed in conjunction with multiplication algorithms such as the 3-bit modified Booth algorithm and the like. Rather than adding a sign extension subfield to extend the left side of each partial product row into alignment with the leftmost bit position of the sum field (e.g., the full product field), a special sign-extension "correction" factor is added to the nonextended partial products. The correction factor mimics the effect of summing the sign-extension bits which would conventionally have been added to the partial product rows. The special correction factor contains fewer bits than the total number of bits contained in all the eliminated sign extension portions, and accordingly, less computer circuitry and/or computer time is required for performing the partial product summation operation. A method which minimizes the computer circuitry or time needed for generating the correction factor is also disclosed. | 6 |
FIELD OF THE INVENTION AND RELATED ART STATEMENT
The present invention relates to an embroidering sewing machine and more particularly to stitching embroidery patterns at high speed and with a stabilized condition.
The embroidery stitching by use of a sewing machine is generally performed by moving in the X-Y directions the embroidery frame relative to the machine needle, which has a cloth extended thereon to be stitched.
It is therefore required that the embroidery frame is moved while the machine needle is located above the cloth irrespectively of the distance in which the embroidery frame is moved. The driving speed, that is, the stitching speed of the sewing machine is therefore so set as to allow the embroidery frame to traverse a maximum distance while the vertically reciprocating machine needle is above the cloth.
With the way of setting speed as mentioned above, the stitching speed remains slow if the distance is short, in which the embroidery frame traverses, and it will take a long time to stitch up the embroidery pattern. Therefore it has been proposed that the stitch data are divided into a plurality of blocks N in consideration of the sequential movements and the rates of moving the distance of the embroidery frame, and each of the data blocks is given a specific rate of stitching speed, thereby to provide a plurality of speed blocks for controlling the stitching speed of the sewing machine. In this case, however, if there is one stitch which requires the embroidery frame to move a long distance, all the speed blocks are influenced by the stitch and must effect speed control on the basis of the long distance, resulting in failure of high speed stitching control of the sewing machine.
Further it has been proposed that each of the stitches is set with a specific speed in dependence on the moving rates of the embroidery frame, so that the speed control may be made to each of the vertical reciprocating movements of the needle in accordance with each rate of the distance in which the embroidery frame traverses.
However in this case, if the moving distance of the embroidery frame varies with high frequency, the machine needle is required to vertically reciprocate at the different rates of speed with the frequency of the change of distance accordingly. This will give rise to a problem that the actuator including the machine motor for driving the machine needle will not be able to positively follow up the speed change.
In particular the common machine motor can not be abruptly switched from high speed to low speed. In order to make the machine motor positively follow up such abrupt speed change, it is required that the machine motor is provided with a braking mechanism which is considerably costly.
Further the repetition of abrupt acceleration and deceleration will give a heavy burden to the machine drive mechanism and will reduce the endurance of the mechanism.
SUMMARY OF THE INVENTION
The present invention has been provided to eliminate the defects and the disadvantages of the prior art. According to the invention, the embroidery stitching is performed to a cloth extended on an embroidery frame which is moved relative to the machine needle in the X-Y directions. The stitch data comprise the data for deciding the relative positions between the machine needle and the embroidery frame. The stitch data are divided into a plurality of blocks in the order of stitches to be formed. Each of the stitch blocks comprises N series of stitch data with each of the subsequent stitch data being elected as the initial stitch data. Each of the stitch data blocks is designated with a specific minimum rate of speed which is then set as the vertically reciprocating speed of the machine needle.
The minimum rate of speed designated to each of the data blocks may be amended. Precisely the minimum rate of speed Vm is compared with the set speed Vs of the immediately preceded data of the block. If Vm is higher than Vs by a predetermined value, the speed may be recognized to be abruptly accelerated. In this case, Vm is amended to obtain a minimum speed Vm to avoid the abrupt acceleration. This amendment may be implemented, for example, by subtracting a predetermined value from Vm or by adding a predetermined value to Vs. On the contrary, if Vm is not higher than Vs by a predetermined value, the minimum rate of speed Vm is amended to be set as Vs.
It is desirable that the minimum rate of speed is determined in consideration of the distance in which the embroidery frame is required to traverse between two stitches. Further it is desirable that the blocked N number of stitch data may be optionally set by the user.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing an embodiment of substantial structure according to the invention;
FIG. 2 is a perspective view of a sewing machine having the invention provided therewith;
FIG. 3 is a table showing a data structure as a first embodiment of the invention;
FIG. 4 is a table showing the relations between distances and speeds according to the invention;
FIG. 5 is a graphic representation of the relations between the original rates of speed and the set rates of speeds as shown in FIGS. 3 and 7;
FIG. 6 is a first flow chart showing the operations of the embodiment according to the invention;
FIG. 7 is a table showing a data structure as a second embodiment of the invention; and
FIG. 8 is a second flow chart showing the operations of the embodiment according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention will now be described in reference to the preferred embodiments as shown in the attached drawings.
In reference to FIG. 2, the sewing machine X of the invention has a needle 121 which is secured to the lower end of a needle bar 120 which is vertically reciprocated as a part of a stitch forming mechanism 112 which will be mentioned hereinlater and further has a carriage 118 which is a part of an X-Y drive mechanism 117 which will be mentioned hereinlater and carries an embroidery frame 119 thereon.
The embroidery frame 119 has a cloth extended thereon to be stitched with relative movements of the carriage 118 in the X-Y directions and of the needle bar 120 and the needle 121 which are reciprocated in the vertical directions. This embroidery stitching may be selected by manual operation of a stitch mode selecting button 104. At the time of normal mode stitching, the cloth is stitched with the vertically reciprocating needle 121 and the cloth feeding mechanism (not shown) for feeding the cloth relative to the needle thereunder.
Now in reference to FIG. 1 showing a substantial structure of the invention in a block diagram and further to FIG. 2, CPU 100 is operated to control the operations of the sewing machine in accordance with the programs stored in a program memory 101. At the time of normal stitching, the CPU 100 is responsive to the orders from a rotation speed ordering device 103 such as a foot operated controller, thereby to control a motor drive circuit 110 so as to rotate a machine motor 111 at an ordered speed, thus to drive the stitch forming mechanism 112 at the ordered speed. On the other hand, at the time of embroidery stitching, the CPU 100 is operated in accordance with the programs stored in a speed setting program memory 13, thereby to operate the X-Y drive mechanism 117 at a speed set by the speed setting programs.
As shown in FIG. 2, the stitch forming mechanism 112 includes the needle bar 120, the needle 121 and the cloth feeding mechanism (not shown) and performs the normal stitching for formation of the various utility stitches including various pattern stitches other than the embroidery stitches. The rotation number of the machine motor 111 is detected by a motor rotation sensor 113 and is feedbacked to the CPU 100 so as to be used for controlling the rotation speed of the machine motor 111.
The embroidering sewing machine has an X-Y motor drive circuit 115 and an X-Y motor 116 in addition to the aforementioned machine motor drive circuit 110 and X-Y drive mechanism 117, and is operated under the control of the stitch data stored in a stitch data memory 10 to perform embroidery stitching. The X-Y drive mechanism 117 includes the carriage 118 and the embroidery frame 119 as shown in FIG. 2 and is operated to move the embroidery frame 119 through the carriage 118 in the X-Y directions relative to the machine needle 121, so that the cloth held by the embroidery frame may be stitched.
A timing signal producing device 114 is operated in cooperation with a main rotation shaft of the sewing machine and detects the rotation phases of the main rotation shaft, thereby to detect the upper and lower positions of the machine needle 121 and produce the corresponding timing signals. The CPU 100 is responsive to the timing signals from the timing signal producing device 114 to control the X-Y motor drive circuit 115, thereby to operate the X-Y drive mechanism 115 through the X-Y motor 116 in timed relation with the machine needle 121.
The above mentioned normal stitching and embroidery stitching are optionally selected by manual operation of the stitch mode selecting button 104 which is provided on the sewing machine X as shown in FIG. 2.
Further the sewing machine X has a display 106 provided thereon for indicating various information thereon under the control of a display control device 105 which is operated by the orders from the CPU 100. The sewing machine further has a temporary memory 11 incorporated therein.
The CPU 100 has further connected thereto a data blocking program memory 12, a speed setting program memory 13, a distance/speed reference table 14 and a block setting button 15.
FIG. 3 shows one example of the stitch data structure stored in the stitch data memory 10. In this example, there are addresses from 0 to 30 (stitching order), each of which has x-y relative coordinates Δx and Δy so set thereto representing a rate of distance in which the embroidery frame 119 is required to traverse.
The distance/speed reference table 14 has set therein the rates of distance and the corresponding rates of speed as shown in FIG. 4.
Each of the addresses further has a speed set corresponding to the relative coordinates (distance). This speed is set in correspondence to the greater one of the coordinates Δx and Δy and in compliance with the speed as specified in the distance/speed reference table 14. For example, since the address 2 has the moving amount 3 in the x direction and the moving amount 2 in the y direction, the speed 400 is set in correspondence to the moving amount 3.
The data blocking program memory 12 has data blocking programs stored therein. The CPU 100 is operated in accordance with the data blocking programs to block the stitch data stored in the stitch data memory 10. This data blocking may be performed prior to the stitching operation or in the process of the stitching operation.
The stitch data are blocked with each of which being successively elected as the initial data (initial address). Each block comprises N series of stitch data as shown in FIG. 3. For example, if N=3, the addresses 1 to 3 belong to block 1, the addresses 2 to 4 belong to block 2 the addresses 3 to 5 belong to block 3, . . . In this way, the stitch data are blocked.
Then a minimum rate of speed is decided in each block in accordance with the programs stored in the speed setting program memory 13. The minimum rate of speed is set as the speed of the initial address of the block.
In case of the block 1, the rates of speed of the addresses are 500, 400 and 300 respectively, and the minimum rate of speed is 300. Therefore the speed of the initial address 1 is set to 300.
In case of the block 2, the rates of speed of the addresses are 400, 300 and 200 respectively, and the minimum rate of speed is 200. Therefore the speed of the initial address is set to 200. In the same way, the following blocks are designated with the minimum rates of speed respectively.
The addresses 29 and 30 have no stitch data to be followed, that is, no N=3 data to be followed. In this case, the minimum rate of speed 100 of FIG. 4 is set to these addresses.
In case of N=5, the same procedure is employed to set a minimum rate of speed to each block.
FIG. 5 shows the set rates of speed of the data blocks plotted in comparison with the original rates of speed (conventional rates of speed), wherein the marks ◯ show the rates of speed of the conventional art, the marks Δ show the set rates of speed in case the blocked stitch data are N=3, and the marks x show the set rates of speed in case that the blocked stitch data are N=5.
As is apparent from the graphs as shown in FIG. 5, the new set rates of speed show few abrupt changes of speed, and the speed change is milder while the speed is slower the increase of N.
According to this embodiment, since the sewing machine is provided with the block setting button 15, the user may optionally set the number N of stitch data to select a high speed stitching operation or a slow and smooth stitching operation.
FIG. 6 shows a flow chart for explaining the operations of blocking the stitch data and setting the rates of speed.
At first, the operation is as follows: setting a point at one address from which the block is formed (step S1), confirming if there are following N number of stitch data (step S2), if there are so many stitch data, reading out the N number of stitch data (step S3), deciding a minimum rate of speed in place of the speed of a maximum rate of distance of the following N number of stitch data (step 4), and setting the minimum rate of speed as the speed of the initial address (step S5), and setting the point at following another one address (step S6), and then the routine is returned to step S2.
In case there are no following N number of stitch data from the pointed address at step S2, the operation is as follows: setting the minimum rate of speed of FIG. 4 as the speed of the pointed address (step S7), setting the point the next address (step S8) and confirming if the data blocking operation is finished or not (step S9). If the operation is not finished, the routine is returned to step S2.
However there may often remain abrupt acceleration of speed even in the blocks of stitch data as mentioned above. This problem may be solved by amending the minimum rate of speed Vm. For example, as shown in FIG. 7, the minimum rate of speed Vm in the data block which is N=3 is compared with the set speed Vs of the immediately preceded stitch data. If the speed difference is more than a predetermined value k, Vm is amended. According to the embodiment, the set speed Vs is added by a predetermined value "a", that is, V'm=Vs+a. The amended V'm is set as the minimum rate of speed V's of the stitch data block. Alternatively, various ways of amendment may be employed. For example, Vm is subtracted by a predetermined value, or Vs and Vm are multiplied by a predetermined value.
On the basis of the minimum rate of speed obtained from the data block N=3 in FIG. 7, the predetermined values may be set such as k=80, a=40 and a=70 to actually amend the set minimum rate of speed.
For example, at the address 1, since the speed acceleration is from 0 to 300, it becomes Vm-Vs>k(=80) which is the object for amendment. Then the calculation Vs+a=0+40 is performed, and thus the amended rate of speed 40 is obtained. This amended rate of speed is newly set to control the machine motor drive circuit 110. The graph shown with the marks and dotted line in FIG. 5 represents the amended rate of speed of the sewing machine, that is, of the vertical reciprocating movement of the machine needle, wherein the abrupt acceleration of speed is moderated.
FIG. 8 shows the operations for amendment of the set minimum rate of speed.
At first, the operation is as follows: setting the point at one address from which the stitch data block is formed (step S11), confirming if there are N number of following stitch data or not (step S12). If there are so many stitch data, the operation continues as follows reading out the N number of stitch data (step S13), deciding the speed of the maximum rate of distance of the stitch data block as the minimum rate of speed Vm (step S14). These operations are the same as those of FIG. 6. Then the minimum rate of speed Vm with the set speed Vs of the immediately preceded stitch data (step S15) is compared, it is determined if Vs-Vm≧k or not (step S16). If Vs-Vm is less than k, the minimum rate of speed Vm as the speed of the initial stitch data of the block (step S17) is set. On the contrary, if Vs-Vm is more the k, a predetermined value "a" is added to the set speed Vs of the immediately preceded stitch data, thereby to set the calculated rate of speed as the speed of the block (step S18). Then the point at another one address from which another block is to be formed (step S19 is newly set), and the routine is returned to the step S12.
In case there are no following N number of stitch data from the step S12, the operation is as follows: setting there the minimum rate of speed of FIG. 4 (step S20), and setting the point at the next address (step S21), and then confirming if the operation is finished or not (step S22). If the operation is not finished, the routine is returned to the step S12.
In the above mentioned embodiment, though amendment is not performed when the deceleration is more than a predetermined value, such deceleration may be amended by Vs-a when Vs-Vm≧k. However in case of deceleration, it is required that the deceleration will always reach the minimum rate of speed Vm, and this is desired to be achieved in each block. Namely if N=3, the set speed must reach Vm at the third stitch without fail. This may be realized by providing a brake.
As mentioned above, according to the embodiments of the invention, instead of deciding the vertical reciprocating speed of the needle per stitch data, each of the stitch data in series is elected as the initial stitch data in each of the blocks including a predetermined number of stitch data, and a maximum rate of speed represented by one of the stitch data in each block is set as the speed for the stitch data constituting the block. Thus the abrupt change of stitching speed of the machine needle may be moderated. This may enable the vertical reciprocating mechanism of machine needle by use of a common machine motor to positively follow the change of speed due to the different rates of distance in which the embroidery frame is required to traverse.
Further an operating button may be provided so as to enable the user to optionally select the number of stitch data for forming each of the stitch data block, that is, to optionally select the speed control of the machine needle. Thus the invention will realize a high speed and steady stitching operation without the risk of abrupt change of movements of the machine needle.
The entire disclosures of Japanese Patent Applications No.8-137441 filed on May 8, 1996 and No.8-168726 filed on Jun. 10, 1996 including specifications, claims, drawings and summaries are incorporated herein by reference in its entirety. | An embroidering sewing machine which is electronically controlled is described, wherein a plurality of addresses of stitch data for controlling the stitching operation are divided into a plurality of blocks each of which comprises N number of stitch data each of which is successively elected as the initial stitch data of each block and provides a distance between the adjacent stitches. The speed of the vertical movement of the machine needle is decided by setting a specific rate of speed corresponding to the maximum rate of distance of each block. The number N may be optionally selected to avoid the abrupt change of speed which may otherwise occur depending upon the embroidery patterns to be stitched. | 3 |
BACKGROUND OF THE INVENTION
[0001] The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
[0002] The present disclosure relates generally to wellbore treatment and development of a reservoir and, in particular, to a method for determining flow distribution in a wellbore during a treatment.
[0003] Hydraulic fracturing, matrix acidizing, and other types of stimulation treatments are routinely conducted in oil and gas wells to enhance hydrocarbon production. The wells being stimulated often include a large section of perforated casing or an open borehole having significant variation in rock petrophysical and mechanical properties. As a result, a treatment fluid pumped into the well may not flow to all desired hydrocarbon bearing layers that need stimulation. To achieve effective stimulation, the treatments often involve the use of diverting agents in the treating fluid, such as chemical or particulate material, to help reduce the flow into the more permeable layers that no longer need stimulation and increase the flow into the lower permeability layers.
[0004] One method includes conducting the treatment through a coiled tubing, which can be positioned in the wellbore to direct the fluid immediately adjacent to layers that need to be plugged when pumping a diverter and adjacent to layers that need stimulation when pumping stimulation fluid. However, the coiled tubing technique requires an operator to know which layers need to be treated by a diverter and which layers need to be treated by a stimulation fluid. In a well with long perforated or open intervals with highly non-uniform and unknown rock properties, typical of horizontal wells, effective treatment requires knowledge of the flow distribution in the treated interval.
[0005] Traditional flow measurement in a well is typically done through production logging using a flow meter to measure the hydrocarbon production rate or injection rate in the wellbore as a function of depth. Based on the logged wellbore flow rate, the production from or injection rate into each formation depth interval is determined based on a measured axial flow rate over that interval. Traditional flow measurement is valid as long as the flow distribution in the well does not change over the time period when logging is conducted.
[0006] However, during a stimulation treatment, the flow distribution in a well can change quickly due to either stimulation of the formation layers to increase their flow capacity or temporary reduction in flow capacity as a result of diverting agents. To determine the effectiveness of stimulation or diversion in the well, an instantaneous measurement that gives a “snap shot” of the flow distribution in a well is desired. Unfortunately, there are few such techniques available.
[0007] One technique for substantially instantaneous measurement is fiber optic Distributed Temperature Sensing (DTS) technology. DTS typical includes an optical fiber disposed in the wellbore (e.g. via a permanent fiber optic line cemented in the casing, a fiber optic line deployed using a coiled tubing, or a slickline unit). The optical fiber measures a temperature distribution along a length thereof based on an optical time-domain (e.g. optical time-domain reflectometry (OTDR), which is used extensively in the telecommunication industry).
[0008] One advantage of DTS technology is the ability to acquire in a short time interval the temperature distribution along the well without having to move the sensor as in traditional well logging which can be time consuming. DTS technology effectively provides a “snap shot” of the temperature profile in the well. DTS technology has been utilized to measure temperature changes in a wellbore after a stimulation injection, from which a flow distribution of an injected fluid can be qualitatively estimated. The inference of flow distribution is typically based on magnitude of temperature “warm-back” during a shut-in period after injecting a fluid into the wellbore and surrounding portions of the formation. The injected fluid is typically colder than the formation temperature and a formation layer that receives a greater fluid flow rate during the injection has a longer “warm back” time compared to a layer or zone of the formation that receives relatively less flow of the fluid.
[0009] As a non-limiting example, FIG. 1 illustrates a graphical plot 2 of a plurality of simulated temperature profiles 4 of a laminated formation 6 during a six hour time period of “warm back”, according to the prior art. As shown, the X-axis 8 of the graphical plot 2 represents temperature in Kelvin (K) and the Y-axis 9 of the graphical plot 2 represents a depth in meters (m) measured from a pre-determined surface level. As shown, a permeability of each layer of the laminated formation 6 is estimated in units of millidarcies (mD). The layers of the formation 6 having a relatively high permeability receive more fluid during injection and a time period for “warm back” is relatively long (i.e. after a given time period, a change in temperature is less than a change in temperature of the layers having a lower permeability). The layers of the formation 6 having a relatively low permeability receive less fluid during injection and a time period for “warm back” is relatively short (i.e. after a given time period, a change in temperature is greater than a change in temperature of the layers having a higher permeability).
[0010] By obtaining and analyzing multiple DTS temperature traces during the shut-in period, the injection rate distribution among different formation layers can be determined. However, current DTS interpretation techniques and methods are based on visualization of the temperature change in the DTS data log, and is qualitative in nature, at best. The current interpretation methods are further complicated in applications where a reactive fluid, such as acid, is pumped into the wellbore, wherein the reactive fluid reacts with the formation rock and can affect a temperature of the formation, leading to erroneous interpretation. In order to achieve effective stimulation, more accurate DTS interpretation methods are needed to help engineers determine the flow distribution in the well and make adjustments in the treatment accordingly.
[0011] This disclosure proposes several methods for quantitatively determining the flow distribution from DTS measurement. These methods are discussed in detail below.
SUMMARY OF THE INVENTION
[0012] An embodiment of a method for determining flow distribution in a formation having a wellbore formed therein comprises the steps of: positioning a sensor within the wellbore, wherein the sensor generates a feedback signal representing at least one of a temperature and a pressure measured by the sensor; injecting a fluid into the wellbore and into at least a portion of the formation adjacent the sensor; shutting-in the wellbore for a pre-determined shut-in period; generating a simulated model representing at least one of simulated temperature characteristics and simulated pressure characteristics of the formation during the shut-in period; generating a data model representing at least one of actual temperature characteristics and actual pressure characteristics of the formation during the shut-in period, wherein the data model is derived from the feedback signal; comparing the data model to the simulated model; and adjusting parameters of the simulated model to substantially match the data model.
[0013] In an embodiment, a method for determining flow distribution in a formation having a wellbore formed therein comprises the steps of: positioning a sensor within the wellbore, wherein the sensor provides a substantially continuous temperature monitoring along a pre-determined interval, and wherein the sensor generates a feedback signal representing temperature measured by the sensor; injecting a fluid into the wellbore and into at least a portion of the formation adjacent the interval; shutting-in the wellbore for a pre-determined shut-in period; generating a simulated model representing simulated thermal characteristics of at least a sub-section of the interval during the shut-in period; generating a data model representing actual thermal characteristics of the at least a sub-section of the interval, wherein the data model is derived from the feedback signal; comparing the data model to the simulated model; and adjusting parameters of the simulated model to substantially match the data model.
[0014] In an embodiment, a method for determining flow distribution in a formation having a wellbore formed therein comprises the steps of: a) positioning a distributed temperature sensor on a fiber extending along an interval within the wellbore, wherein the distributed temperature sensor provides substantially continuous temperature monitoring along the interval, and wherein the sensor generates a feedback signal representing temperature measured by the sensor; b) injecting a fluid into the wellbore and into at least a portion of the formation adjacent the interval; c) shutting-in the wellbore for a pre-determined shut-in period; d) generating a simulated model representing simulated thermal characteristics of a sub-section of the interval during the shut-in period; e) generating a data model representing actual thermal characteristics of the sub-section of the interval, wherein the data model is derived from the feedback signal; f) comparing the data model to the simulated model; g) adjusting parameters of the simulated model to substantially match the data model; and h) repeating steps d) through g) for each of a plurality of sub-sections defining the interval within the wellbore to generate a flow profile representative of the entire interval.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] These and other features and advantages of the present invention will be better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings wherein:
[0016] FIG. 1 is a graphical plot of a plurality of simulated temperature profiles of a laminated formation during a six hour time period of warm back, according to the prior art;
[0017] FIG. 2 is a schematic diagram of an embodiment of a wellbore treatment system;
[0018] FIG. 3 is a graphical plot showing an embodiment of a simulated temperature profile and an actual measured temperature profile for a wellbore treatment at a first time period;
[0019] FIG. 4 is a graphical plot showing a simulated temperature profile and an actual measured temperature profile for the wellbore treatment shown in FIG. 3 , taken at a second time period;
[0020] FIG. 5 is a schematic plot showing an embodiment of a plurality of measured temperature profiles, each of the measured temperature profiles taken at a discrete time period during a shut-in period of a wellbore treatment;
[0021] FIG. 6 is a graphical representation of temperature vs. time for a sub interval of the profile represented in FIG. 5 ;
[0022] FIG. 7 is a graphical representation of an interpreted flow profile of the wellbore treatment represented in FIG. 5 ;
[0023] FIG. 8A is a graphical plot of a measured temperature profile of the laminated formation of FIG. 1 ;
[0024] FIG. 8B is graphical plot of an interpreted temperature of a fluid prior to injection into the laminated formation of FIG. 1 ;
[0025] FIG. 8C is graphical plot of an interpreted temperature of the laminated formation of FIG. 1 , prior to an injection procedure; and
[0026] FIG. 8D is graphical plot of an interpreted volume of fluid injected into the laminated formation of FIG. 1 at various depths thereof.
DETAILED DESCRIPTION OF THE INVENTION
[0027] Referring now to FIG. 2 , there is shown an embodiment of a wellbore treatment system according to the invention, indicated generally at 10 . As shown, the system 10 includes a fluid injector(s) 12 , a sensor 14 , and a processor 16 . It is understood that the system 10 may include additional components.
[0028] The fluid injector 12 is typically a coiled tubing, which can be positioned in a wellbore formed in a formation to selectively direct a fluid to a particular depth or layer of the formation. For example, the fluid injector 12 can direct a diverter immediately adjacent a layer of the formation to plug the layer and minimize a permeability of the layer. As a further example, the fluid injector 12 can direct a stimulation fluid adjacent a layer for stimulation. It is understood that other means for directing fluids to various depths and layers can be used, as appreciated by one skilled in the art of wellbore treatment. It is further understood that various treating fluids, diverters, and stimulation fluids can be used to treat various layers of a particular formation.
[0029] The sensor 14 is typically of Distributed Temperature Sensing (DTS) technology including an optical fiber 18 disposed in the wellbore (e.g. via a permanent fiber optic line cemented in the casing, a fiber optic line deployed using a coiled tubing, or a slickline unit). The optical fiber 18 measures the temperature distribution along a length thereof based on optical time-domain (e.g. optical time-domain reflectometry). In certain embodiments, the sensor 14 includes a pressure measurement device 19 for measuring a pressure distribution in the wellbore and surrounding formation. In certain embodiments, the sensor 14 is similar to the DTS technology disclosed in U.S. Pat. No. 7,055,604 B2, hereby incorporated herein by reference in its entirety.
[0030] The processor 16 is in data communication with the sensor 14 to receive data signals (e.g. a feedback signal) therefrom and analyze the signals based upon a pre-determined algorithm, mathematical process, or equation, for example. As shown in FIG. 2 , the processor 16 analyzes and evaluates a received data based upon an instruction set 20 . The instruction set 20 , which may be embodied within any computer readable medium, includes processor executable instructions for configuring the processor 16 to perform a variety of tasks and calculations. As a non-limiting example, the instruction set 20 may include a comprehensive suite of equations governing a physical phenomena of fluid flow in the formation, a fluid flow in the wellbore, a fluid/formation (e.g. rock) interaction in the case of a reactive stimulation fluid, a fluid flow in a fracture and its deformation in the case of hydraulic fracturing, and a heat transfer in the wellbore and in the formation. As a further non-limiting example, the instruction set 20 includes a comprehensive numerical model for carbonate acidizing such as described in Society of Petroleum Engineers (SPE) Paper 107854, titled “An Experimentally Validated Wormhole Model for Self-Diverting and Conventional Acids in Carbonate Rocks Under Radial Flow Conditions,” and authored by P. Tardy, B. Lecerf and Y. Christanti, hereby incorporated herein by reference in its entirety. It is understood that any equations can be used to model a fluid flow and a heat transfer in the wellbore and adjacent formation, as appreciated by one skilled in the art of wellbore treatment. It is further understood that the processor 16 may execute a variety of functions such as controlling various settings of the sensor 14 and the fluid injector 12 , for example.
[0031] As a non-limiting example, the processor 16 includes a storage device 22 . The storage device 22 may be a single storage device or may be multiple storage devices. Furthermore, the storage device 22 may be a solid state storage system, a magnetic storage system, an optical storage system or any other suitable storage system or device. It is understood that the storage device 22 is adapted to store the instruction set 20 . In certain embodiments, data retrieved from the sensor 14 is stored in the storage device 22 such as a temperature measurement and a pressure measurement, and a history of previous measurements and calculations, for example. Other data and information may be stored in the storage device 22 such as the parameters calculated by the processor 16 and a database of petrophysical and mechanical properties of various formations, for example. It is further understood that certain known parameters and numerical models for various formations and fluids may be stored in the storage device 22 to be retrieved by the processor 16 .
[0032] As a further non-limiting example, the processor 16 includes a programmable device or component 24 . It is understood that the programmable device or component 24 may be in communication with any other component of the system 10 such as the fluid injector 12 and the sensor 14 , for example. In certain embodiments, the programmable component 24 is adapted to manage and control processing functions of the processor 16 . Specifically, the programmable component 24 is adapted to control the analysis of the data signals (e.g. feedback signal generated by the sensor 14 ) received by the processor 16 . It is understood that the programmable component 24 may be adapted to store data and information in the storage device 22 , and retrieve data and information from the storage device 22 .
[0033] In certain embodiments, a user interface 26 is in communication, either directly or indirectly, with at least one of the fluid injector 12 , the sensor 14 , and the processor 16 to allow a user to selectively interact therewith. As a non-limiting example, the user interface 26 is a human-machine interface allowing a user to selectively and manually modify parameters of a computational model generated by the processor 16 .
[0034] In use, a fluid is injected into a formation (e.g. laminated rock formation) to remove or by-pass a near well damage, which may be caused by drilling mud invasion or other mechanisms, or to create a hydraulic fracture that extends hundreds of feet into the formation to enhance well flow capacity. A temperature of the injected fluid is typically lower than a temperature of each of the layers of the formation. Throughout the injection period, the colder fluid removes thermal energy from the wellbore and surrounding areas of the formation. Typically, the higher the inflow rate into the formation, the greater the injected fluid volume (i.e. its penetration depth into the formation), and the greater the cooled region. In the case of hydraulic fracturing, the injected fluid enters the created hydraulic fracture and cools the region adjacent to the fracture surface. When pumping stops, the heat conduction from the reservoir gradually warms the fluid in the wellbore. Where a portion of the formation does not receive inflow during injection will warm back faster due to a smaller cooled region, while the formation that received greater inflow warms back more slowly.
[0035] FIG. 3 illustrates a graphical plot 28 showing a simulated temperature profile 30 and an actual measured temperature profile 32 for a wellbore treatment (e.g. an acid treatment in a horizontal well in a carbonate formation) at a first time period. As a non-limiting example, the first time period is immediately after the shut-in procedure (i.e, stopping the wellbore treatment and ceasing fluid flow into the formation or the like) has been initiated. As shown, the X-axis 34 of the graphical plot 28 represents temperature in degrees Celsius (° C.) and the Y-axis 36 of the graphical plot 28 represents a depth of the formation in meters (m), measured from a pre-determined surface level. In certain embodiments, the simulated temperature profile 30 is based on at least one of estimated petrophysical, mechanical, and thermal properties of the formation, thermal properties (e.g. thermal conductivity and heat capacity) of the inject fluid, and flow properties of the inject fluid and formation. As a non-limiting example, the estimated properties of the formation can be manually provided by a user. As a further non-limiting example, the estimated properties can be generated by the processor 16 based upon stored data and known or estimated information about the formation. It is understood that a simulated pressure profile (not shown) can be generated by the processor 16 based on the estimated properties of the formation. The actual measured temperature profile 32 is based upon a data acquired by the sensor 14 during the shut-in after a period of fluid injection.
[0036] FIG. 4 illustrates a graphical plot 38 showing a simulated temperature profile 40 and an actual measured temperature profile 42 for a wellbore treatment (e.g. an acid treatment in a horizontal well in a carbonate formation) at a second time period. As a non-limiting example, the second time period is approximately four hours after the first time period. It is understood that any time period can be used. As shown, the X-axis 44 of the graphical plot 38 represents temperature in degrees Celsius (° C.) and the Y-axis 46 of the graphical plot 38 represents a depth of the formation in meters (m), measured from a pre-determined surface level. In certain embodiments, the simulated temperature profile 40 is based on at least one of estimated petrophysical, mechanical, and thermal properties of the formation, thermal properties (e.g. thermal conductivity and heat capacity) of the inject fluid, and flow properties of the inject fluid and formation. As a non-limiting example, the estimated properties of the formation can be manually provided by a user. As a further non-limiting example, the estimated properties can be generated by the processor 16 based upon stored data and known information about a location of the formation. It is understood that a simulated pressure profile (not shown) can be generated by the processor 16 based on the estimated properties of the formation. The actual measured temperature 32 is based upon a data acquired by the sensor 14 during the shut-in after a period of fluid injection.
[0037] As an illustrative example a layer of the formation at a particular depth is estimated to have a first set of petrophysical properties having a particular permeability and the simulated temperature profiles 30 , 40 are generated based upon a model of the estimated properties of the formation (i.e. forward model simulation). However, where the actual measured temperatures 32 , 42 are not aligned with the simulated temperature profiles 30 , 40 the user modifies at least one of the estimated properties of the formation and the parameters of the model relied upon to generate the simulated temperature profiles 30 , 40 such that the simulated temperature profiles 30 , 40 substantially match the actual measured temperatures 32 , 42 . In this way, the model used to generate the simulated temperature profiles 30 , 40 is updated based upon the actual measurements of the sensor 14 . It is understood that the updated model can be used as a base model for future applications on the same or similar formation. It is further understood that the flow distribution in the formation can be quantitatively determined from the updated model.
[0038] FIGS. 5-7 illustrate a method for determining a flow distribution in a formation according to another embodiment of the present invention. As a non-limiting example, the flow distribution in the formation is determined using a numerical inversion algorithm. As a further non-limiting example, a simulated temperature curve (i.e. simulated model) is generated for a given flow rate, an injection fluid temperature, and an initial formation temperature for any given depth by solving a numerical finite difference heat transfer model for modeling a convective flow of a cooler fluid into a permeable formation, as appreciated by one skilled in the art.
[0039] FIG. 5 illustrates a schematic plot 47 showing a plurality of measured temperature profiles 48 , each of the measured temperature profiles 48 taken at a discrete time period t 1 , t 2 , t 3 , t 4 during the shut-in period after an injection. As shown, the X-axis 49 of the graphical plot 47 represents temperature and the Y-axis 50 of the graphical plot 47 represents a depth of the formation measured from a pre-determined surface level. In certain embodiments, a wellbore interval of interest 52 is divided into a plurality of sub sections 54 of pre-determined cross-sectional length. For each of the sub sections 54 the measured temperature profile is plotted against time, as shown in FIG. 6 .
[0040] Specifically FIG. 6 illustrates a graphical plot 56 showing a plurality of discrete temperature measurements 58 of the sensor 14 , each of the measurements taken at the discrete time periods t 1 , t 2 , t 3 , t 4 , respectively. A theoretical temperature curve 60 (i.e. simulated model) is modeled to intersect the discrete measurements 58 . As shown, the X-axis 62 of the graphical plot 56 represents time and the Y-axis 64 of the graphical plot 56 represents a temperature.
[0041] In particular, the temperature measurements 58 for a particular one of the sub sections 54 are compared to the theoretical temperature curve 60 . In certain embodiments a numerical optimization algorithm is applied to the measured temperature measurements 58 and the theoretical temperature curve 60 to find a “best match” and to minimize an error difference therebetween. For example, the numerical optimization algorithm is a sum of squares of the difference between the data values of temperature measurements 58 and corresponding points along the theoretical temperature curve 60 . As a further example, a plurality of input parameters for generating the theoretical temperature curve 60 (i.e. simulated model) are automatically modified to obtain a best match between the theoretical temperature curve 60 and the temperature measurements 58 . In certain embodiments, the input parameters include a flow rate during injection, a fluid temperature, an initial formation temperature, and a flow rate during shut-in, for example. It is understood that a number of discrete combinations of the input parameters may generate the same theoretical temperature curve. As such, an average of the input parameters can be used for the fitting procedure between the theoretical temperature curve 60 and the temperature measurements 58 .
[0042] Once the theoretical temperature curve 60 is “fitted” to the temperature measurements 58 , the modified input parameters of the theoretical temperature curve 60 represent the average flow rate, the fluid temperature, and the initial formation temperature. A flow profile (i.e. the profile of the fluid volume injected during the injection period) can be obtained by repeating the comparison and fitting process described above for the remainder of the sub sections 54 . As an example, FIG. 7 illustrates a graphical plot 65 showing a flow profile 66 (i.e. a flow distribution). As shown, the X-axis 67 of the graphical plot 65 represents a volume of injected fluid and the Y-axis 68 of the graphical plot 65 represents a depth of the formation measured from a pre-determined surface level.
[0043] FIGS. 8A-8D illustrate an example of applying a numerical inversion algorithm to the synthetic data generated by a numerical simulator, as shown in FIG. 1 . In particular, FIG. 8A illustrates a graphical plot 69 showing a first measured temperature profile 70 taken at a first time period and a second measured temperature profile 72 taken at a second time period. As a non-limiting example the first time period is immediately after a shut-in procedure is initiated and the second time period is six hours after the first time period. It is understood that any time period can be used. As shown, the X-axis 74 of the graphical plot 69 represents temperature in Kelvin (K) and the Y-axis 76 of the graphical plot 69 represents a depth of the formation in meters (m), measured from a pre-determined surface level.
[0044] In operation, a theoretical temperature curve (i.e. simulated model) is generated based upon a numerical finite difference heat transfer model for modeling a convective flow of a cooler fluid into a permeable formation, as appreciated by one skilled in the art. As a non-limiting example, the input parameters of the heat transfer model include estimates for a flow rate during injection, a fluid temperature, an initial formation temperature, and a flow rate during shut-in. The temperature profiles 70 , 72 are compared to the theoretical curve in a manner similar to that shown in FIG. 6 . In certain embodiments a numerical optimization algorithm is applied to the measured temperature profiles 70 , 72 and the theoretical curve to automatically find a “best match” and to minimize an error difference between the temperature profiles 70 , 72 and the theoretical curve. As a non-limiting example, the input parameters are modified so that the resultant theoretical temperature curve substantially matches an appropriate one of the temperature profiles 70 , 72 . Once the theoretical curve is “fitted” to the appropriate one of the temperature profiles 70 , 72 , the modified input parameters of the theoretical curve represent the average flow rate, the fluid temperature, and the initial formation temperature, as shown in FIGS. 8B , 8 C, and 8 D respectively. It is understood that a number of discrete combinations of the input parameters may generate the same theoretical temperature curve. As such, an average of the input parameters can be used for the fitting procedure between the theoretical temperature curve and the temperature the temperature profiles 70 , 72 .
[0045] Specifically, FIG. 8B is a graphical plot 78 showing an inversed (i.e. interpreted from the inversion algorithm) temperature curve 80 for the injected fluid. As shown, the X-axis 82 of the graphical plot 78 represents temperature in Kelvin (K) and the Y-axis 84 of the graphical plot 78 represents a depth of the formation in meters (m), measured from a pre-determined surface level. FIG. 8C is a graphical plot 86 showing an average temperature profile 88 for the formation prior to receiving the injected fluid (with a standard deviation shown as a shaded region). As shown, the X-axis 90 of the graphical plot 86 represents temperature in Kelvin (K) and the Y-axis 92 of the graphical plot 86 represents a depth of the formation in meters (m), measured from a pre-determined surface level. FIG. 8D is a graphical plot 94 showing a simulated average volume curve 96 for the injected fluid (with a standard deviation shown as a shaded region). As shown, the X-axis 98 of the graphical plot 94 represents volume in cubic meters of fluid injected into one meter of the formation (m 3 /m) and the Y-axis 100 of the graphical plot 94 represents a depth of the formation in meters (m), measured from a pre-determined surface level. As such, the temperature curve 80 , temperature profile 88 , and the volume curve 96 provide an accurate flow distribution profile for the formation, which can be relied upon for subsequent treatment processes.
[0046] In an embodiment, a temperature data measured by the sensor 14 is compared against a set of pre-generated theoretical curves called type curves. The type curves are typically in dimensionless form, with dimensionless variables expressed as a combination of physical variables. The temperature data received from the sensor 14 is pre-processed to be presented in dimensionless form and to overlay on the theoretical type curves. By shifting the measured temperature data to find a best matched type curve, one can determine the physical parameters that correspond to the matched type curve, including the flow rate into the formation. Carrying out the same procedure for all depths, one can construct a flow profile along the wellbore as in the previous methods. An example of type curve techniques for DTS interpretation is disclosed in U.S. Pat. Appl. Pub. No. 2009/0216456, hereby incorporated herein by reference in its entirety.
[0047] Several DTS interpretation methods have been discussed herein. The methods involve using a mathematical model (simulated model) to predict the expected temperature response and compare the prediction with actual measurements (measured data model). By adjusting the simulated model parameters to match the measured data model, a flow distribution in the well is deduced. For those skilled in the art, different temperature models can be used, or different techniques could be used to attain the match with the DTS measured data. However, such variations fall under the spirit of this invention.
[0048] The interpreted flow profile provides stimulation field practitioners with detailed knowledge to make real time decisions to tailor the stimulation operation to maximize the stimulation effectiveness. The stimulation operations may include the following activities: position coiled tubing to a zone that has not been effectively stimulated to maximize stimulation fluid contact/inflow into that zone; position coiled tubing to a zone that has already been fully stimulated to spot a diverting agent to temporarily plug the zone so the subsequent stimulation fluid can flow into other zones that need further stimulation, rather than wasting fluid in the already stimulated zone; switch a treating fluid if it is shown ineffective; switch a diverter if it is shown ineffective; and set a temporary plug or other types of mechanical barrier in the well to isolate the already stimulated zones to allow separate treatment of the remaining zones. Other operations may rely on the flow profile generated by embodiments of the methods disclosed herein.
[0049] To maximize stimulation effectiveness, a stimulation operation can be designed to consist of multiple injection cycles followed by shut-in periods in which DTS data is acquired. The DTS data is analyzed immediately to provide the field operator with the flow distribution in the well, which can be used to make adjustments of the subsequent treatment schedule if necessary to maximize stimulation effectiveness. Well production can hence be maximized as a result of the optimized stimulation.
[0050] The preceding description has been presented with reference to presently preferred embodiments of the invention. Persons skilled in the art and technology to which this invention pertains will appreciate that alterations and changes in the described structures and methods of operation can be practiced without meaningfully departing from the principle, and scope of this invention. Accordingly, the foregoing description should not be read as pertaining only to the precise structures described and shown in the accompanying drawings, but rather should be read as consistent with and as support for the following claims, which are to have their fullest and fairest scope. | A method for determining flow distribution in a formation having a wellbore formed therein includes the steps of positioning a sensor within the wellbore, wherein the sensor generates a feedback signal representing at least one of a temperature and a pressure measured by the sensor, injecting a fluid into the wellbore and into at least a portion of the formation adjacent the sensor, shutting-in the wellbore for a pre-determined shut-in period, generating a simulated model representing at least one of simulated temperature characteristics and simulated pressure characteristics of the formation during the shut-in period, generating a data model representing at least one of actual temperature characteristics and actual pressure characteristics of the formation during the shut-in period, wherein the data model is derived from the feedback signal, comparing the data model to the simulated model, and adjusting parameters of the simulated model to substantially match the data model. | 4 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates generally to a tie-down securing method for motorcycles.
[0003] 2. Prior Art
[0004] Motorcycles come in various styles, sizes, and utility function. Some are designed for recreational cruising and travel, while others are designed for performance, racing, or off road use. Invariably at some point in the association with the motorcycling experience it becomes necessary to transport the motorcycle in a truck, or on a trailer. Motorcycles intended for off road use such as dirt bikes or racing motorcycles offer no other legal means of being moved other than on a trailer or in a truck. This necessitates securing the motorcycle in a manner that keeps the motorcycle safely attached to the transport medium while attempting to minimize or eliminate damage to the motorcycle. Typically, the motorcycle is lashed or tied to the transport medium using a combination of straps, ropes, bungee cords, or commercial style tie-down straps.
[0005] Numerous devices and methods exist for securing or tying a motorcycle to a transport medium. For example, U.S. Pat. Nos. 6,171,034B1-6,109,494-6,065,914-5,701,771-5,529,448-5,326,202 all offer various methods and equipment intended to provide the securing method necessary to provide stable and secure attachment of the motorcycle to the transport medium. While these prior art devices disclosed in the cited patents do offer a means of securing the motorcycle, they are not without certain limiting and inconvenience factors, most often associated with damage potential as a result of misapplication of the installation or an inherent design oversight. Herewith are two examples. In U.S. Pat. No. 6,065,914 no provision is made that prevents the handlebar Shook attachment device 32 from sliding on the handlebar 50 . Any inward movement of the attachment device 32 toward the motorcycle 12 could potentially loosen the apparatus. In U.S. Pat. No. 6.171.034 B1, the shackle 14 is bolted around the motorcycle fork tubes. Potential misapplication of the shackle 14 to a fork tube of a diameter not applicable to the specified application could result in potential indentation damage to the fork tube resultant of over tightening of the bolt 24 in the fastening attempt. The potential for damage to the fork tubes or the whole motorcycle as a result of failure to remove the shackle 14 exists in any possible attempt to operate the motorcycle with these shackles 14 still attached. There is also the additional inconvenience of the installation and removal process of the shackle 14 required of every use. It is therefor desirable to provide a restraint system that not only removes any subjective installation decision making on the part of the user, but makes the process as expedient and uncomplicated as possible.
OBJECTIVES OF THE INVENTION
[0006] Accordingly, objectives of the quick disconnect motorcycle tie down system are:
[0007] to provide a conveniently located metal to metal attachment point for a motorcycle securing device consisting of a quick disconnect coupling feature, one part of which is incorporated on the end of a nylon or material tie down strap, the other part of which is attached to the motorcycle handlebars, frame, or frame component;
[0008] to be very quickly and easily installed or removed;
[0009] to provide a multiplicity of applications irrespective of motorcycle manufacturer, model, style, or intended use or function;
[0010] to provide an attachment method which eliminates potential damage resultant of contact between the securing straps and the motorcycle.
[0011] Additional objectives and advantages of the invention will become apparent to all from a consideration of the drawings and ensuing descriptions.
BRIEF SUMMARY OF THE INVENTION
[0012] The applicant has invented a motorcycle securing method incorporating a quick disconnect coupling feature between the securing device, typically a strap, and the motorcycle. Attachment of the quick disconnect male end to the motorcycle can be done in one of two ways. 1.) By inserting a goose neck expander inside the handlebar, secured by utilizing a specially machined bolt incorporating the quick disconnect male end portion as the bolt head, thereby providing both the gooseneck securing bolt and the male quick disconnect fitting in one. This becomes the interconnect attachment point for the female disconnect coupler end of the tie down strap. 2.) By replacement of a motorcycle frame assembly bolt with a bolt incorporating the male quick disconnect fitting as the bolt head, again providing the interconnect attachment point for the female disconnect coupler end of the tie down strap. Incorporation of a quick disconnect coupling feature with the traditional tie down strap arrangement provides both a secure hard point attachment location on the motorcycle itself along with a hard point attachment connection on the end of the tie down strap. Additionally, once the male disconnect coupler-headed bolts are permanently installed on the motorcycle, either inside the handlebar as a part of the internal gooseneck expander, or as a frame replacement bolt, this method of anchoring a motorcycle is devoid of any decision making required of attempting to discern the most potentially damage free and balance point secure location or attachment point on the motorcycle.
BREIF DESCRIPTION OF THE SEVERAL DRAWING VIEWS
[0013] [0013]FIG. 1 schematically shows the tie down system in place as a front view of a motorcycle secured in a truck bed utilizing the embodiment of the invention mounted inside the handlebar ends and anchored with the tie down straps to the truck bed floor (top view) or truck bed side (bottom view).
[0014] [0014]FIG. 2 is a closer view of the embodiment of the invention inserted into the motorcycle handlebar end to which is attached the tie down strap utilizing the quick disconnect coupler.
[0015] [0015]FIG. 3 is a closer view of the embodiment of the invention with the end cover cap in place.
[0016] [0016]FIG. 4 is a close up view of an optional variation of the invention embodiment using a D-ring style bar end in place of the quick disconnect coupler, thus becoming a permanently installed component through which the tie down strap is inserted.
[0017] [0017]FIG. 5 is an exploded view of the embodiment of the invention showing the component pieces and their relative assembly and fitment relationship.
[0018] [0018]FIG. 6 shows the motorcycle handlebar with inserted invention embodiment and connected female quick disconnect coupler.
[0019] [0019]FIG. 7 is a cutaway view of the invention embodiment showing the assembled components fit and in place inside the motorcycle handle bar end with the female quick disconnect coupler attached.
[0020] [0020]FIG. 8 shows motorcycle handlebar end with cutaway view of installed components (lower drawing) with attached bar end cover cap in place (upper and lower drawing).
[0021] [0021]FIG. 9 shows a cutaway view (lower drawing) of the optional invention embodiment consisting of the non-disconnecting D-ring bar end tie down strap attachment fitting (upper and lower drawing).
DRAWING REFERENCE NUMERALS
[0022] [0022] 1. motorcycle 2. tie down strap 3. handlebar grip 4. handlebar 5. quick disconnect coupler 6. D-ring 7. truck bed 8. truck bed tie down anchor 9. brake lever 10. gas tank 11. bar end 12. bar end cap 13. fixed D-ring style bar end 14. threaded gooseneck bolt 15. male detent end of threaded gooseneck bolt 16. thrust washer 17. internal gooseneck threaded expander 18. quick disconnect actuating spring 19. internal locking detent ball bearings 20. bar end insert shank 21. plain end screwdriver slot 22. D-ring coupling insert
DETAILED DESCRIPTION OF THE INVENTION
[0023] In FIG. 1, a motorcycle 1 containing the preferred embodiment of the invention installed in the handlebar grip 3 is depicted secured to a truck bed 7 , and secured using the tie down strap 2 attached to the quick disconnect coupler 5 utilizing the D-ring 6 . The tie down strap 2 is then secured to the truck bed anchor 8 . Motorcycles are manufactured using a Multiplicity of various handlebar 4 shapes, sizes, styles, and dimensions, without uniformity of handlebar grip 3 size, distance of the grips from each other, or distance from the ground. Depiction of the motorcycle 1 and the included embodiment of the invention is not to be construed as any application specificity limitation concerning the motorcycle 1 , the handlebar 4 or handlebar grip 3 size, shape, or dimension.
[0024] [0024]FIG. 5 shows the exploded view components which comprise the embodiment of the invention. The internal gooseneck threaded expander 17 is comprised of an internally threaded solid metal plug of an outside diameter determined by the application specificity and cut on an angle in such manner as to allow the contact face surfaces of the cut pieces to override each other when tightened together by the threaded gooseneck bolt 14 . These pieces are adjoined to the end of the bar end 11 by insertion of the threaded gooseneck bolt 14 through the thrust washer 16 and continuing through the hole in the end of bar end 11 which is manufactured in such manner as to provide a bar end insert shank 20 which is the same diameter as the internal threaded gooseneck expander 17 , the diameter being determined by the specific application. Once inserted inside the hollow handlebar grip 3 the assembly is then tightened by means of a screwdriver blade engaged in the plain end screwdriver slot 21 on the end of the threaded gooseneck bolt 14 . The tightening force applied to the threaded gooseneck bolt 14 serves to further wedge the internal threaded gooseneck expander 17 inside the hollow handlebar grip 3 as a function of the angular cut of the component pieces.
[0025] [0025]FIG. 6 shows an external view of the invention embodiment in place inside the handlebar grip with the quick disconnect coupler 5 attached. Incorporated with the quick disconnect coupler 5 is the D-ring 6 attached by means of the D-ring coupling insert 22 . The coupling insert 22 would be manufactured in such manner as to allow the D-ring 6 to pivot or move as may be required of the angular plane of attachment determined by the anchor point to which the opposite end of the tie down strap 2 is attached. This insert 22 could be a threaded rod or bolt screwed into the threaded end of the quick disconnect coupler 5 , or could be a rod or bolt welded in place in the end of the quick disconnect coupler 5 dependent upon the manufacturing particulars of the coupler. The size, shape and dimension of the D-ring 6 as illustrated is not to be construed as any specificity limitation as may apply to this component of the embodiment of the invention.
[0026] [0026]FIG. 7 is a cutaway view of the invention embodiment in place inside the handlebar grip 3 . The internal gooseneck threaded expander 17 is secured using the threaded gooseneck bolt 14 . The threaded gooseneck bolt 14 passes through the thrust washer 16 and the bar end 11 . The bar end insert shank 20 is then inserted into the handlebar grip 3 , and the components secured in place by tightening of the threaded gooseneck bolt 14 . On the end of the threaded gooseneck bolt 14 is the male detent end 15 machined in such manner as to provide the locking surface against which are positioned the internal locking detent ball bearings 19 incorporated inside the quick disconnect coupler 5 . A rearward movement of the outside cylindrical housing cover of the quick disconnect coupler 5 against the internal quick disconnect actuating spring 18 allows release of the lock position of the internal locking detent ball bearings 19 . The rearward most position of the outside cylindrical housing cover of the quick disconnect coupler 5 allows insertion of the open end of the coupler 5 over the male detent end 15 of the threaded gooseneck bolt 14 . Once the outside cylindrical housing cover of the quick disconnect coupler 5 is released, the quick disconnect actuating spring 18 returns the cover to the closed position, forcing the internal locking indent ball bearings 19 into a locked position against the male detent end 15 of the threaded gooseneck bolt 14 . The positive lock function of the quick disconnect coupler 5 over the threaded gooseneck bolt 14 is a function of the internal clearance tolerance between the internal detent ball bearings 19 and the threaded gooseneck bolt 14 male detent end 15 . This male detent end 15 is manufactured in such manner as to provide a recessed mating surface against which the internal detent ball bearings 19 are recessed and held into position once any rearward actuating force is removed from the outside cylindrical housing cover of the quick disconnect coupler 5 . The quick disconnect actuating spring 18 returns the housing cover to the static position which is designed to lock the internal locking detent ball bearings 19 effectively against the male detent end 15 of the threaded gooseneck bolt 14 when so engaged. It is the positive locking aspect of this coupling device which forms the basis of the security this interconnect system offers as it applies to securing a motorcycle for transport.
[0027] [0027]FIG. 4 and FIG. 9 depict an optional variation of the invention embodiment which employs use of the same internal gooseneck threaded expander 17 tightened with the threaded gooseneck bolt 14 affixed as an extension of the bar end insert shank 20 . This bar end insert shank 20 is additionally manufactured incorporating a fixed D-ring style bar end 13 which thus provides a fixed attachment point for the S hook end of any tie down strap 2 as may be such affixed. While not offering the quick disconnect aspect of the preferred embodiment of the invention, it does offer a convenient, readily accessible alternative style access point to which may be affixed a securing strap. FIG. 4 illustrates this installation as it would appear in relation to the handlebar grip 3 while incorporating a threaded-thru style tie down strap 2 .
[0028] [0028]FIG. 8 illustrates the preferred embodiment of the invention with the quick disconnect coupler 5 removed and a snap on bar end cap 12 secured in place. This cap acts as an aesthetic enhancement to the installation while protecting the installed components against the abrasive or contamination effects of any dirt and debris. This bar end cap 12 could be manufactured of plastic, metal, nylon, or any material providing the aesthetics or functionality as may be deemed necessary by virtue of the applicability. FIG. 3 illustrates the embodiment of the invention inclusive of this bar end cap 12 .
[0029] To secure the motorcycle to a trailer or truck bed, the motorcycle 1 is placed in an upright position in the truck bed 7 . The bar end cap 12 is removed and the quick disconnect coupler 5 end of the tie down strap 2 is inserted into the open bar end 11 . Rearward actuation of the quick disconnect coupler 5 outside cylindrical housing cover allows engagement of the coupler end with the male detent end 15 of the threaded gooseneck bolt 14 . Quick disconnect actuating spring 18 assistance in return of the outside cylindrical housing cover to the forward static position locks the internal locking detent ball bearings 19 in position against the male detent end 15 of the threaded gooseneck bolt 14 . Once connected, tightening of the tie down strap 2 against the truck bed anchor 8 secures the motorcycle in position.
[0030] An optional alternative method of utilizing the quick coupling aspect of this invention as it applies to securing a motorcycle is to use the threaded gooseneck bolt 14 as a replacement bolt in the frame, or a frame member component of the motorcycle 1 . Utilization of an application specific version of this bolt would be threaded and sized in such manner as to become a direct replacement of the chosen frame bolt(s). Incorporating the male detent end 15 of the threaded gooseneck bolt 14 would provide an additional metal to metal securing point on the motorcycle 1 . Utilization of this bolt devoid of the components 11 and 17 required of the handlebar grip 3 mount allows esthetic embellishment as may be desired, dependent upon the application. It retains the secure interconnectivity feature afforded the invention by utilization of the quick disconnect coupler 5 equipped tie down strap 2 being positively connected to the male detent end 15 of the bolt.
[0031] Installation of both the handlebar grip 3 mounting method of the preferred embodiment of the invention, combined with the optional frame replacement bolt version of the threaded gooseneck bolt 14 on the same motorcycle would provide a fast, convenient, easily used method able to be utilized in a manner that effectively secures both ends of the motorcycle, a situation not afforded by other prior art motorcycle restraint devices. | An apparatus for securing a motorcycle in an upright position for transport. It consists of a female quick disconnect coupler attached to one end of a tie down strap, used to connect to a male coupler fitting machined as the end of an attachment bolt affixed either inside the open end of the handlebar, or threaded into the motorcycle frame or frame component. This provides a fast, convenient metal to metal securing point at the front end of the motorcycle at the outward end of the handlebars, as well as a coupling point located in another position as may be necessary to secure the motorcycle. Utilization of the quick disconnect coupler system provides the fastest means of attaching the tie down strap in a positive lock, metal to metal connection. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an optical scanning device for scanning a plurality of media and an image forming apparatus using the optical scanning device.
2. Discussion of the Background
A color electrophotographic image forming apparatus includes in a housing a plurality of optical devices which respectively emit as scanning beams a plurality of laser beams output by a plurality of light sources. The scanning beams emitted from the housing scan their corresponding photoconductors, serving as a plurality of media, to form thereupon latent images of an image in their corresponding colors, respectively, each corresponding to a different color. The latent images are developed, i.e., made into visible images, with developers of corresponding colors, respectively, and the developed images are sequentially transferred onto a transfer sheet (recording sheet), superimposing one upon another, thereby forming a color image on the transfer sheet.
More specifically, a color electrophotographic image forming apparatus such as a digital copier and a laser printer includes four photoconductor drums arranged in a direction in which a transfer sheet is conveyed. Charged surfaces of the photoconductor drums are exposed by scanning beams corresponding to yellow, magenta, cyan, and black, respectively, so that latent images corresponding to yellow, magenta, cyan, and black are formed thereupon. Then, the latent images are developed into visible images by developing devices using developers of corresponding colors. The visible images are sequentially transferred onto a transfer sheet, superimposing one upon another, thereby forming a color image on the transfer sheet.
In the above-described color image forming apparatus, for scanning the four photoconductor drums with laser beams, respectively, a plurality of scanning devices, one for each photoconductor drum, are used. Accordingly, a large space is necessary, and thus the size of the image forming apparatus is increased.
Japanese Patent Laid-open publication No. 4-127115 discloses an optical scanning device for color image forming apparatuses in which a plurality of optical beams are incident on a single deflector and respective scanning image forming optical systems including mirrors are arranged in a vertically layered manner so that the whole parts of the optical scanning device are accommodated in one housing.
FIGS. 5 and 6 illustrate an optical scanning device described above. FIG. 5 is a plane view for explaining arrangement of a reflecting device and an optical detecting device in the optical scanning device, and FIG. 6 is a side view illustrating a relation between the optical scanning device and each photoconductor drum.
In the optical scanning device illustrated in FIG. 5 , laser beams are emitted from laser light sources 100 , and shaped by a coupling lens 200 , respectively. After passing an aperture 300 , a cylindrical lens 400 , serving as a first image forming optical system, forms a respective one of the laser beams into a line image long in the main scanning direction in the vicinity of a deflecting reflective surface of a polygon mirror ( 500 a ) of a rotating deflector 500 . Then, each of the laser beams is deflected by the polygon mirror ( 500 a ) so as to sweep a predetermined plane. Further, first and second scanning lenses 600 , 700 , serving as a second image forming optical system, and three mirrors 800 (illustrated in FIG. 6 ) project the laser beam on a surface 1200 of a photoconductor drum 1100 , thereby scanning the surface 1200 .
In the optical scanning device illustrated in FIG. 5 , two laser beams emitted from different laser light sources 100 are incident on different deflecting reflective surfaces of the single polygon mirrors ( 500 a ) of the rotating deflector 500 at the same time. Thus, the two laser beams are deflected simultaneously by the single polygon mirror ( 500 a ).
Referring to FIG. 6 , the rotating deflector 500 includes the polygon mirror ( 500 a ) and another polygon mirror ( 500 b ) arranged in upper and lower steps, respectively, and two optical systems projecting the laser beams from the two laser light sources 100 on the surfaces 1200 , respectively, are provided for the polygon mirror ( 500 a ) at the upper step and two other similar optical systems are provided for the polygon mirror ( 500 b ) at the lower step. Thus, four optical systems in total are arranged in one housing.
Thus, the above-described scanning device scans the surfaces 1200 of the four photoconductor drums 1100 at the same time with four laser beams emitted from four laser light sources 100 for forming images of magenta (M), cyan (C), yellow (Y), and black (BK), respectively. In FIG. 6 , colors of images formed on the four photoconductor drums 1100 are indicated by M, C, Y, and BK, respectively.
In the optical scanning device described above, to detect each timing of scanning the surfaces 1200 with the laser beams, generally, synchronizing sensors 1000 are provided as illustrated in FIG. 5 . Further, synchronizing mirrors 900 are arranged in the vicinity of both ends of optical paths of the laser beams scanning the surfaces 1200 , respectively, so that the laser beams deflected by the deflector 500 are reflected toward the synchronizing sensors 1000 , respectively.
However, providing a synchronizing mirror 900 and a synchronizing sensor 1000 for each of the four laser beams increases the cost of the scanning device. Further, the size of the housing for the scanning device is increased, leading to increase in the size of an image forming apparatus using such a scanning device.
SUMMARY OF THE INVENTION
According to one aspect of the present invention, an optical scanning device for scanning plural surfaces includes a plurality of laser light units each configured to emit a laser beam, a deflecting device configured to deflect the laser beams from the plurality of laser light units to sweep a plurality of predetermined planes, respectively, and a scanning image forming optical unit configured to project the laser beams deflected by the deflecting device on the plural surfaces, respectively, to scan the plural surfaces with the laser beams. The scanning image forming optical unit includes a plurality of optical detecting devices configured to detect the laser beams and a first plurality of reflecting devices positioned to reflect at least two laser beams of the laser beams toward one of the plurality of optical detecting devices.
According to another aspect of the present invention, an image forming apparatus includes a plurality of photoconductors, and an optical scanning device configured to scan the plurality of photoconductors to form a latent image in a color thereupon. The optical scanning device includes a plurality of laser light units each configured to emit a laser beam, a deflecting device configured to deflect the laser beams from the plurality laser light units to sweep a plurality of predetermined planes, respectively, and a scanning image forming optical unit configured to project the laser beams deflected by the deflecting device on the plurality of photoconductors, respectively, to scan the plurality of photoconductors with the laser beams. The scanning image forming optical unit includes a plurality of optical detecting devices configured to detect the laser beams and a first plurality of reflecting devices positioned to reflect at least two laser beams of the laser beams toward one of the plurality of optical detecting devices.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete appreciation of the present invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in conjunction with accompanying drawings, wherein:
FIG. 1 is a side view of an optical scanning device according to an embodiment of the present invention;
FIG. 2 is a plane view of the optical scanning device schematically illustrating the overall construction of the optical scanning device;
FIG. 3 is a plane view illustrating an optical scanning device according to another embodiment of the present invention;
FIG. 4 is a schematic drawing illustrating an image forming apparatus according to an embodiment of the present invention;
FIG. 5 is a plane view for explaining a construction of a background optical scanning device; and
FIG. 6 is a side view illustrating a relation between the optical scanning device and photoconductor drums of an image forming apparatus.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views, preferred embodiments of the present invention are described.
FIG. 1 is a side view of an optical scanning device according to one embodiment of the present invention, illustrating an arrangement of optical elements and photoconductor drums with respect to one side of a rotating deflector. FIG. 2 is a plane view of the optical scanning device, schematically illustrating the overall construction of the optical scanning device.
The optical scanning device n FIG. 2 includes four light source units each having a laser light source 1 , a coupling lens 2 , and an aperture 3 , and four cylindrical lenses 4 each serving as a first image forming optical system for a laser beam emitted from each light source unit. The light source units emit laser beams, Lm, Lc, Ly and Lk, for magenta (M), cyan (C), yellow (Y) and black (BK) colors, respectively.
At the laser light sources, laser beams from the laser light sources 1 are shaped by the coupling lenses 2 , and pass the apertures 3 to be emitted as the laser beams (Lm, Lc, Ly, Lk) for respective colors. Each of the laser beams (Lm, Lc, Ly, Lk) is formed by the cylindrical lens 4 as the first image forming optical system into a line image long in the main scanning direction in the vicinity of a deflecting reflective surface of a rotating deflector 5 serving as a deflecting device.
The rotating deflector 5 includes polygon mirrors ( 5 a , 5 b ) arranged in upper and lower steps, as illustrated in FIG. 1 . The laser beams, Lc and Ly, for cyan and yellow colors are incident on the polygon mirror ( 5 a ) at the upper step, and the laser beams, Lm and Lk, for magenta and black colors are incident on the polygon mirror ( 5 b ) at the lower step.
The laser light source 1 for magenta and the laser light source 1 for cyan, and the laser light source 1 for yellow and the laser light source 1 for black are respectively arranged deviated from each other in the horizontal direction as illustrated in FIG. 1 for facilitating assembling of the optical scanning device. Thereby, the laser beams, Lm and Lc, and the laser beams, Ly and Lk, emerge in directions different from each other, respectively.
Accordingly, two mirrors ( 13 a , 13 b ) are provided so that the laser beam, Lm, is reflected by the mirror ( 13 a ) so as to be incident on the rotating deflector 5 in the same incident direction as for the laser beam, Lc, and so that the laser beam, Lk, is reflected by the mirror ( 13 b ) so as to be incident on the rotating deflector 5 in the same incident direction as for the laser beam, Ly.
Each of the laser beams (Lm, Lc, Ly, Lk) reaching the polygon mirror ( 5 a , 5 b ) is deflected by the polygon mirror ( 5 a , 5 b ) so as to sweep a predetermined sweeping plane. Each of the laser beams (Lm, Lc, Ly, Lk) scans a surface 12 of a corresponding one of four photoconductor drums 11 and forms an image in a respective color. The surface 12 serves as a surface for forming an image in a corresponding color, first and second scanning lenses 6 , 7 serve as a second image forming optical system, and first, second and third reflecting mirrors 81 , 82 , 83 , illustrated in FIG. 1 , serve in scanning the surface 12 . The first scanning lens 6 is an fθ lens, and the second scanning lens 7 is a troidal lens having a long plate-like shape.
Thus, the surfaces 12 of the four photoconductor drums 11 for forming images of magenta, cyan, yellow and black colors are scanned at the same time by the four laser beams (Lm, Lc, Ly, Lk).
In FIG. 1 , out of the four photoconductor drums 11 , only two of them, the photoconductor drums 11 for magenta and cyan colors, at the right side of the rotating deflector 5 , and the first and second scanning lenses 6 , 7 and the first, second and third mirrors 81 , 82 , 83 for the laser beams, Lm and Lc, for scanning the surfaces 12 of the two photoconductor drums 11 in their axial directions, i.e., in the direction perpendicular to the sheet surface, are shown.
In FIG. 2 , the reflecting mirrors 81 , 82 are not arranged perpendicular to the sheet surface. However, only the parts of the mirrors 81 , 82 where laser beams are actually incident on are illustrated in straight lines for the sake of illustration. Further, the third mirrors 83 and the photoconductor drums 11 are not shown. In FIG. 1 , illustration has been omitted for the optical path from each laser light source 1 to the polygon mirror ( 5 a , 5 b ) and for the optical elements on the optical path.
In the optical scanning device illustrated in FIG. 2 , the laser beams emitted from the different light sources 1 are incident at the same time on the different deflecting reflective surfaces of the polygon mirrors ( 5 a , 5 b ) of the rotating deflector 5 , so that two laser beams each, the laser beams, Lm and Lc, and the laser beams, Ly and Lk, are deflected by the polygon mirrors ( 5 a , 5 b ), respectively. Thereby, the construction of the optical scanning device is simplified.
Further, in the optical scanning device, synchronizing mirrors ( 9 m , 9 c , 9 y , 9 k ) for the four laser beams (Lm, Lc, Ly, Lk) are provided, as illustrated in FIGS. 1 and 2 , on a plane parallel to each sweeping plane of the laser beams (Lm, Lc, Ly, Lk) deflected by the polygon mirrors ( 5 a , 5 b ) in the vicinity of respective one ends of optical paths of the laser beams scanning the surfaces 12 of the photoconductor drums 11 in the main scanning direction.
The two laser beams, Lc and Lm, deflected by the polygon mirrors ( 5 a , 5 b ) are caused to be incident on a synchronizing sensor ( 10 a ) serving as a common optical detecting device by the synchronizing mirrors, 9 c and 9 m . Similarly, the two laser beams, Ly and Lk, deflected by the polygon mirrors ( 5 a , 5 b ) are caused to be incident on a synchronizing sensor ( 10 b ) serving as another common optical detecting device by the synchronizing mirrors, 9 y and 9 k , illustrated in FIG. 2 .
The timings of emitting the laser beams, Lc and Lm, and those of emitting the laser beams, Ly and Lk, at the light sources 1 are controlled so that the laser beams, Lc and Lm, and the laser beams, Ly and Lk, will not be incident at the same time on the synchronizing sensor ( 10 a ) and the synchronizing sensor ( 10 b ), respectively.
Further, in the embodiment, to make each laser beam easily incident on the synchronizing sensor ( 10 a , 10 b ), a condensing lens ( 14 a ) may be provided in front of the synchronizing sensor ( 10 a ), and a condensing lens ( 14 b ) may be provided in front of the synchronizing sensor ( 14 b ).
Furthermore, additional mirrors may be arranged to guide the laser beams (Lm, Lc, Ly, Lk) reflected by the synchronizing mirrors ( 9 m , 9 c , 9 y , 9 k ) to the synchronizing sensors ( 10 a , 10 b ).
In an optical scanning device for scanning a plurality of media with a plurality of laser beams emitted from a plurality of light sources, by arranging synchronizing mirrors at the positions described above, the plurality of laser beams reflected by a single surface of a polygon mirror can be made incident on a single synchronizing sensor. Thereby, the number of synchronizing sensors can be reduced, the construction of the optical scanning device can be simplified, the size of the optical scanning device can be reduced, and the cost of the optical scanning device can be reduced.
In particular, in an optical scanning device scanning a plurality of media, a plurality of laser beams deflected by a rotating deflector so as to sweep different sweeping planes respectively, for example, those laser beams deflected by the polygon mirrors ( 5 a , 5 b ) arranged in upper and lower steps illustrated in FIG. 1 , can be made incident on a common synchronizing sensor by providing synchronizing mirrors on a plane parallel to each of the different sweeping planes of the plurality of laser beams deflected by the rotating deflector in the vicinity of respective optical paths of the deflected laser beams after having been reflected by reflecting mirrors.
Now, an optical scanning device according to another embodiment of the present invention is described referring to FIG. 3 . FIG. 3 is a drawing similar to FIG. 2 , illustrating a construction of the optical scanning device. In FIG. 3 , parts identical or corresponding to those in FIG. 2 are denoted by like reference numerals, and the description thereof is omitted.
In this embodiment, as illustrated in FIG. 3 , with respect to the laser beams (Lm, Lc, Ly, Lk), second synchronizing mirrors ( 9 m 2 , 9 c 2 , 9 ys , 9 k 2 ) are provided as second reflecting devices on a plane parallel to each sweeping plane of the laser beams (Lm, Lc, Ly, Lk) deflected by the polygon mirrors ( 5 a , 5 b ) in the vicinity of respective ends of optical paths of the laser beams (Lm, Lc, Ly, Lk) scanning the photoconductor drums as media at the side opposite to the side where the synchronizing mirrors ( 9 m , 9 c , 9 y , 9 k ) are provided as in the previous embodiment.
Further, in FIG. 3 , the laser beams, Lm and Lc, at the right side, reflected by the second synchronizing mirrors ( 9 m 2 , 9 c 2 ) to pass a common condensing lens ( 14 c ) are made incident onto a synchronizing sensor ( 10 c ) serving as a common optical detecting device separate from the synchronizing sensor ( 10 a ).
Furthermore, in FIG. 3 , the laser beams, Ly and Lk, at the left side, reflected by the second synchronizing mirrors ( 9 y 2 , 9 k 2 ) to pass a common condensing lens ( 14 d ) are made incident onto a synchronizing sensor ( 10 d ) serving as a common optical detecting device separate from the synchronizing sensor ( 10 b ).
With the configuration as described above, the timings when the four laser beams (Lm, Lc, Ly, Lk) for respective colors pass predetermined positions near both ends of the optical paths of the laser beams (Lm, Lc, Ly, Lk) scanning the surfaces 12 can be detected by the four synchronizing sensors ( 10 a , 10 b , 10 c , 10 d ). Thereby, a period of time each laser beam scans a surface in the main scanning direction can be precisely measured.
Furthermore, by adjusting a frequency of a control clock of each laser light source 1 to be lower when the period of time measured as above is longer than a predetermined period of time and higher when the measured period of time is shorter than the predetermined period of time, an error in a length of a scanning area on the surface 12 with each laser beam due to an error in a shape of each optical element or an error in a mounting position of each optical element can be corrected.
In the embodiment described above, the single rotating deflector 5 having the polygon mirrors ( 5 a , 5 b ) arranged in upper and lower steps is provided as a deflecting device, and four laser beams in total are deflected by the single deflecting device, two laser beams each by different reflecting surfaces of the polygon mirrors ( 5 a , 5 b ), and the two laser beams are detected by a common synchronizing sensor. However, the above-described advantages of the present invention can be obtained in an optical scanning device having a configuration different from the above-described one. For example, in an optical scanning device for performing optical writing of information using laser beams from a plurality of laser light sources, the above-described advantage can be obtained by providing a synchronizing mirror as a reflecting device, with respect to each of the laser beams from two or more laser light sources, on a plane parallel to sweeping planes of the laser beams deflected by the rotating deflector 5 in the vicinity of respective one ends of optical paths of the laser beams scanning surfaces, and making each of the laser beams incident on a common synchronizing sensor.
Furthermore, the above-described deflecting device is not limited to a polygon mirror of a rotating deflector. Still furthermore, the present invention can be practiced in an optical scanning device having a plurality of rotating deflectors.
Now, an electrphotographic image forming apparatus according to an embodiment of the present invention is described. FIG. 4 illustrates an exemplary construction of the image forming apparatus.
The image forming apparatus is a color laser printer, and includes a housing 30 in which sheet feeding cassettes ( 31 A, 31 B) are arranged in two steps. Feeding rollers ( 15 A, 15 B) are provided in the housing 30 to feed sheets of different sizes accommodated in the sheet feeding cassettes ( 31 A, 31 B) one by one from the uppermost sheets in the sheet feeding cassettes ( 31 A, 31 B). Furthermore, a conveying roller 16 to convey each of the sheets, a conveying belt to convey a sheet to a transfer part where a toner image is transferred onto the sheet, a fixing roller 18 to fix the transferred image onto the sheet, and a discharging roller 19 to discharge the sheet are arranged to form a transfer sheet conveying path on a substantially same plane.
Four photoconductor drums ( 11 m , 11 c , 11 y , 11 k ) for forming images of magenta (M), cyan (C), yellow (Y), and black (BK) colors, serving as media to be scanned, are arranged along the sheet conveying path. The photoconductor drums ( 11 m , 11 c , 11 y , 11 k ) rotate in directions indicated by arrows.
An optical scanning device 21 is arranged above the photoconductor drums ( 11 m , 11 c , 11 y , 11 k ). The optical scanning device 21 is the one illustrated in and described with respect to FIGS. 1 and 2 . The above-described rotating deflector 5 and optical elements are accommodated in a single case ( 21 a ).
Four laser beams (Lm, Lc, Ly, Lk) are emerged through four windows provided at a lower surface of the case ( 21 a ) to scan surfaces (surfaces to be scanned) charged by charging devices in the main scanning direction to thereby form electrostatic latent images thereupon.
Developing devices ( 25 m , 25 c , 25 y , 25 k ) accommodating magenta, cyan, yellow and black developers, respectively, are provided downstream of scanning positions on the photoconductor drums ( 11 m , 11 c , 11 y , 11 k ) scanned by the laser beams (Lm, Lc, Ly, Lk) in the rotating directions of the photoconductor drums ( 11 m , 11 c , 11 y , 11 k ). Each of the developing devices ( 25 m , 25 c , 25 y , 25 k ) includes a unit case 251 , a developer cartridge 252 , e.g., a toner cartridge, and a developing roller 253 .
Transfer rollers may be arranged at positions opposing the photoconductor drums ( 11 m , 11 c , 11 y , 11 k ) sandwiching the transfer belt 17 with the transfer rollers and the photoconductor drums ( 11 m , 11 c , 11 y , 11 k ). Cleaning units may be arranged downstream of respective transfer positions of the photoconductor drums ( 11 m , 11 c , 11 y , 11 k ).
Latent images formed on the surfaces of the photoconductor drums ( 11 m , 11 c , 11 y , 11 k ) scanned by the laser beams (Lm, Lc, Ly, Lk) are developed by the developing devices ( 25 m , 25 c , 25 y , 25 k ) to make them visible with magenta, cyan, yellow, and black developers, e.g., toners, respectively.
The toner images in the respective colors formed on the surfaces of the photoconductor drums ( 11 m , 11 c , 11 y , 11 k ) are sequentially transferred onto a sheet fed by one of the sheet feeding cassettes ( 31 A, 31 B) and conveyed by the conveying belt 17 in a direction indicated by arrow. Thereby, a full color toner image is formed on that sheet. The sheet is then passed through the fixing roller 18 , thereby fixing the toner image onto the sheet, and discharged by the discharging roller 19 .
The optical scanning device 21 of the embodiment according to the present invention can be made compact and inexpensive as described above. Furthermore, by using the optical scanning device 21 for an image writing device of an image forming apparatus, the image forming apparatus can be made compact and inexpensive.
The present invention can be applied to image forming apparatuses including an optical scanning device using laser beams, other than laser printers, such as copying machines and facsimile apparatuses.
Numerous additional modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the present invention may be practiced otherwise than as specifically described herein.
The present application claims priority and contains subject matter related to Japanese Patent Application No. 2001-024739 filed in the Japanese Patent Office on Jan. 31, 2001, and the entire contents of which are hereby incorporated by reference. | An optical scanning device for scanning plural surfaces including a plurality of laser light units each configured to emit a laser beam, a deflecting device configured to deflect the laser beams from the plurality laser light units to sweep a plurality of predetermined planes, respectively, and a scanning image forming optical unit configured to project the laser beams deflected by the deflecting device on the plural surfaces, respectively, to scan the plural surfaces with the laser beams. The scanning image forming optical unit includes a plurality of optical detecting devices configured to detect the laser beams and a first plurality of reflecting devices positioned to reflect at least two laser beams of the laser beams toward one of the plurality of optical detecting devices. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is the U.S. national phase of PCT/KP2007/000010 filed Jul. 15, 2007, which claims priority of Korean Patent Application No. KP-06-249 filed Jul. 17, 2006.
FIELD OF THE INVENTION
The present invention generally relates to a novel die assembly for extruding and drawing ferrous and non-ferrous metal, and also to a method of making the same.
BACKGROUND OF THE INVENTION
Since a die was first invented, no innovative changes have been made in its structure; it has been improved only in the aspect of its material and now came to a state, where coating technique was combined. Structural innovation that enables reduction of production cost and improvement of operational capabilities is highly important in the art. It is to develop a novel die container system with high strength and a safe method of assembling die core to such system by a great force.
The U.S. Pat. No. 4,270,380 provides a die assembly having an interlayer between a die nib and a casing composed of all-crystalline ceramic material having a heating liquidus temperature within the range of 500° C.-570° C. The solidified interlayer maintains uniform shrink-fitted compression on the nib during usage of the assembly, and thus makes it possible to overcome die cracking, its operational capability being improved.
International Patent Application WO 2005058519 describes a diamond die having a die core and at least two pre-stressed rings housing the die core and a method of making the same. The rings may be shrink fit, press-fit, or otherwise formed around each other such that elastic and plastic deformation occurs and the rings are at near yield state, but not yielded state.
A die having an interlayer between the die core and the casing is also explained in Russian Patent No. 1477497, which is characterized in that the yield strength of the interlayer material is 0.5-0.9 times that of the casing material. An interlayer with 0.25 mm thickness is formed by dipping the core in the dissolved interlayer material. The die core coated with interlayer is then shrink-fitted to the pre-heated casing, the inside surface of which is threaded to a meta screw using a chaser prior to fitting. As a result, an easily removable die with longer life time is obtained.
By utilizing the die casings and assembling methods that have been known until now, it is impossible to considerably improve its operational capabilities by fitting the die core with a great force and prevent die cracking when fitting the light weight die core with a great force.
If a die made of wear-resistant materials like hard alloy and extra hard alloy having low tensile strength and high compression strength is assembled by a great force in a safe mode without cracking the die core, its operating capability would be significantly improved.
The aim of the present invention is to attain a long lasting die assembly with an improved operational capability by providing a rigid die container system with great strength and a new method of assembling the die core to it by a great force without die cracking.
SUMMARY OF THE INVENTION
A die assembly provided by the present invention comprises a die core; at least one pre-stressed ring placed around the die core; and a die casing surrounding the ring. The ring is plastically deformed and hardened via compression stress exceeding its material yield limit, and the mating geometric feature of the core and the ring is tapered towards the exit.
According to the present invention, die core material is selected preferably from hard alloy, extra hard alloy, nitride, carbide, man-made diamond or combination of them.
In an embodiment of the present invention, the die casing material is selected from steel or alloy steel with hardness preferably in the range of HRC 40-55.
In a preferred embodiment of the present invention, the pre-stressed ring has the dimensionless thickness D 2 /d 2 of 1.15-1.3, in which D 2 and d 2 are respectively outer and inner diameter of the ring.
According to the present invention, ring material is selected preferably from steel, alloy steel or ferrous/non-ferrous metal alloy of the same strength and plastic deformation characteristics as those of steel and alloy steel, its hardness preferably being in the range of HRC 30-45.
In an embodiment, the mating geometrical feature of the die and the ring is tapered towards the exit at an angle of 1-3°.
The present invention also provides a method of forming a die assembly according to the present invention comprising steps of:
a) grinding of the tapered outer surface of the die; b) machining and heat-treating of the ring and the die casing, and grinding or finish-machining of interface between the casing and the ring; c) plastically press-fitting the ring to the inner surface of the die casing such that the ring has compression stress exceeding its material yield strength by 10-40%; d) machining of the inner surface of the press-fitted ring to a taper fitted to the taper of the die core; e) press-fitting of the die core to the tapered inner surface of the ring.
According to the present invention, in step a) the die core is ground or finish-machined to the outer surface roughness of Ra 1.25 or more.
In an embodiment of the present invention, in step b) the interface of the casing and the ring is ground or finish-machined to the roughness of Ra 2.5 or more.
In step d) the inner surface of the ring may be ground or finish-machined to the roughness of Ra 2.5 or more.
The present invention, with its unique die container system and novel method of assembling the core to the system by a great force without die cracking, makes it possible to provide a long lasting die assembly with surprisingly high performance, lower production cost and smaller dimension.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-section view of a die assembly according to the present invention, wherein a die core is press-fitted to the ring housed in a casing.
FIG. 2 is a cross-section view of a die core according to the present invention, wherein the outer surface of the core is tapered; numerals 10 and 7 respectively refer to entrance and exit for passage of stock; 13 refers to bearing zone.
DETAILED DESCRIPTION OF THE INVENTION
An Improved Die Container System with High Strength
It is generally known to those skilled in the art that the working pressure formed on the die container with a single cylinder is at most half of material yield strength; when the container has more than one casings, the working pressure is more than half of material yield strength, which is expressed by the formula (1)
P = σ S n ( K 2 n - 1 ) 2 K 2 n ( 1 )
wherein σ s denotes yield strength of cylindrical casing material; n denotes number of cylinders; K denotes proportion (b/a) of its outer radius b to its inner radius a. According to the above formula, P is 0.5σ s for n=1, and P is 0.66σ s for n=2.
The formula (1) based on Lame formula corresponds to thick cylindrical container system with more than one cylinder. Container systems of drawing dies designed on the basis of the formula is of large dimensions and hard to be used in practice.
When a relatively thin ring is plastically press-fitted to a thicker cylindrical body, a die container which is particularly high in strength and rigidity, but small in dimensions can be obtained. It was verified by the practice that such die container system is of great effect if used in die assemblies for extruding and drawing and axisymmetric holes, of various sizes and types.
FIG. 1 shows a die assembly according to an embodiment of the present invention wherein a die core is assembled in such a die container. In FIG. 1 , 1 indicates cylindrical casing with larger thickness, 2 indicates a ring press-fitted to the casing 1 , 3 indicates the die core.
D 1 and H 1 respectively refer to the outer diameter and the height of the die casing 1 ; and d 1 and h 1 refer to the inner diameter and the depth of cavity of the die casing 1 where the die core and the ring are assembled; D 2 , d 2 and h 1 respectively refer to outer and inner diameter and height of the ring 2 prior to being fitted to the casing. The bottom 12 of the die casing 1 has sufficient thickness and the opening 8 for discharging the stock is tapered at an angle of 40-45°.
The die container system is comprised of thicker die casing and relatively thinner pre-stressed ring, wherein the dimensionless thickness of the casing 1 is expressed in α 1 =D 1 /d 1 , the dimensionless thickness of the ring is expressed in α 2 =D 2 /d 2 . α 1 is always above 1.6 and α 2 is in the range from 1.12 to 1.3.
The casing 1 is made of steel or alloy steel, and the ring 2 is made of steel, alloy steel or ferrous/non-ferrous metal alloy of the same strength and plastic deformation characteristics as those of steel or alloy steel.
To sufficiently increase casing strength and ring's effect, the casing 1 and the ring 2 are heat-treated to a required hardness.
The relatively thinner ring 2 is plastically press-fitted to the thicker casing 1 in such a way that the ring 2 is strain hardened. As a result, while less high tensile stress is created on the die casing 1 , higher compression stress is formed on the ring 2 , the strength of the casing being increased by 20%.
When ring 2 is press-fitted to the state of plastic deformation with great negative allowance, a compression stress (pre-stress) exceeding its material yield strength is created on the ring 2 , under which crystallization of ring metal becomes closer, its strength being increased.
The resulting die container system, with its high strength, makes it possible to fit a die core to the container by a greater force. Besides, due to its small dimensions, it becomes ideal die container.
Fitting of the ring 2 is done by means of a press.
When the casing 1 and the ring 2 are fitted on the interface 6 by a press, the negative allowance is expressed with reference to the diameter by formula (2)
δ 1 =D 2 −d 1 (2)
wherein D 2 and d 1 respectively denote the outer diameter of the ring 2 and the inner diameter of the casing 1 prior to fitting.
A Novel Method of Assembling.
The present invention also provides a novel assembling mode and mating geometric feature of the core 3 and the container system, which enable minimal chances of die cracking when it is fitted to the system using great force. The mating geometrical feature 5 of the die core 3 and the ring 2 is conically tapered, which results in gradual increase of uniform pressure throughout the mating feature when fining the core 3 into the ring 2 . Thus, the die core 3 is safely fitted to the ring 1 without cracking.
The outer surface of the die core is made to be tapered at angle in the range of 1-3° considering dimension of the die core 3 , the thickness of the ring 2 , working condition and task of die, as shown in FIG. 2 .
The outer diameter of upper surface 9 of the die core prior to fitting is indicated by D 3 , its height by H 3 , the outer dimension of the core is not bigger than the ISO 1684 (1975) standards.
After the ring 2 is assembled to the casing 1 , the inner surface of the ring is finish-machined to a taper fitted to the taper of the die core.
The die core 3 is press-fitted to the tapered inner surface of the ring 2 with a certain negative allowance δ 2 by utilizing a press.
The ring 2 already press-fitted to the casing 1 is once again compressed and hardened between the die core 3 and the casing 1 to be precisely and firmly fitted to die core 3 .
The negative allowance of the die core 3 and the ring 2 is expressed with reference to the diameter by formula (3)
δ 2 =D 3 −d 2 ′ (3)
, wherein D 3 denotes the diameter of the upper surface 9 of the die core; d 2 ′ denotes the inner diameter of the ring 2 at the height H 3 from the bottom of the casing cavity when it is machined to a taper that fitted to the taper of the core 3 .
The interfaces between the casing 1 , the ring 2 and the core 3 are finished by grinding or machining in such a manner that they are precisely fitted with each other.
δ 1 and δ 2 expressed by formulas (2) and (3) are determined referring to material used for the die core and the casing, their structures and dimensions.
Effect of the Ring
To improve operational capability of the die assembly by maximizing ring effect and thus assembling die core by a great force in a safe mode, it is very important to make proper selection of the angle at which the die core is tapered, ring material, its thickness α 2 , and negative allowances δ 1 and δ 2 .
If the die core is tapered at an angle less than 1°, local assembling pressure may occur during assembly. If that angle exceeds 3°, it is difficult to provide required thickness of the ring as the ring thickness prior to fitting is relatively thin.
The value of negative allowance δ 1 is determined such that the ring can be compressed and hardened via a great compression stress exceeding its material yield strength by 10-40%.
The value of negative allowance δ 2 is determined in such a manner that the die core is fitted via compression stress not less than elastic limit.
To take suitable ring material, accurate selection of hardness and thickness of the ring is particularly important for increasing intermediate ring effect. If hardness or rigidity is not high enough, it is impossible to increase the strength of intermediate ring during press-fitting and attain a rigid container with a great pre-stress and strength. If the hardness of the ring is too high, it will lead to die cracking due to imperfection of accuracy in machining and assembling the interfaces.
If dimensionless thickness of the ring α 2 is less than 1.12, it is too thin to accomplish high strength and fitting rigidity of the ring. Furthermore, if it is more than 1.3, it is too thick to be compressed and hardened via great compression stress and a light-weight die container can not be obtained.
According to value of δ 1 and δ 2 , press-fitting force of the ring P 1 and press-fitting force of the core P 2 are determined. A reasonable state of deformation via compression stress, which is favorable for improving operational capability of shaping metal, may occur depending on P 2 .
Since the die container system with pre-stressed ring has high strength, the die core press-fitted by a great force is hardened via high compression stress, which is favorable for die operational capabilities.
Conical interface of the die core 3 and the ring 2 maintains a uniform press-fitted pressure all around the core during assembly, the pressure being gradually increased and thus effectively prevents cracking of die.
The ring 2 permits the die container system to have higher strength as well as long term capability during operation.
During operation of die, the force of bonding core is relaxed by repeated working pressure and heat load, which results in change of die operating capability and fatigue cracking. However, as the inner and outer surfaces of the ring according to the present invention is firmly bond to the casing 1 and the core 3 and deformation in volume of the ring is controlled due to conical outer surface of the core, the bonding force is mainly maintained, which results in long term capability of the die core.
As is shown above, the ring has a surprisingly high effect in increasing the casing strength, preventing die cracking during assembly and improving die capability.
If two or more rings are likewise press-fitted plastically, the strength of the container system can be further increased. Such assembling method can be applied in manufacturing higher pressure equipment such as dies for making boron nitride and diamond.
Method of Making the Die Assembly of the Present Invention
The die core 3 is made of hard alloy or other wear resistant die materials having high compression strength, its outer dimension not exceeding ISO standards 1684. Its outer surface is tapered at an angle in the range of 1-3°. It is ground to the roughness of Ra 1.25 or more.
The core of the present invention may have reasonable inner profiles 11 which are already known to those skilled in the art, that is, circular, elliptical, polygonal, or trapezoidal in shape with rounded corners, to optimally support uniform radial compression for uniform internal stresses.
With respect to D 3 , the inner diameter of the ring is expressed in d 2 <D 3 −δ 2 , the outer diameter in D 2 =α 2 d 2 . Then the height of the ring is equal to h 1 ; the inner diameter d 1 is machined to δ 1 shorter than D 2 , the outer diameter of the ring.
The inner diameter of the casing 1 and the outer diameter of the ring 2 are chamfered prior to press-Fitting, which is favorable for press-fitting.
The casing is made of steel or alloy steel; the ring is made of steel, alloy steel or ferrous/non-ferrous metal alloy having the same strength and plastic deformation characteristics as those of steel or alloy steel.
The casing 1 and the ring 2 are heat-treated at the temperature in the range of 800-900° C., and then oil-cooled and tempered to the hardness of HRC 40-55 of casing and HRC 30-45 of the ring.
The interface between the casing 1 and the ring 2 is finish-machined to the roughness of Ra 2.5 or more, which is followed by press-fitting the ring to the casing with negative allowance δ 1 , the interface being lubricated.
After the ring is press-fitted to the casing, the inner diameter is being tapered by grinding or finish-machining it to the roughness of Ra 2.5 or more.
The die core 3 is press-fitted into the ring by a press. The pressing force is imposed until the core reaches the bottom 4 of the casing 1 . The interface between the core and the ring is also lubricated.
Example
Table 1 shows dimensions and assembling characteristics of dies of two types. Their casings were composed of alloy steel 40 Cr and heat-treated to the hardness of HRC 42 and 40; their rings were made of alloy steel 20 Cr and heat-treated to the hardness of HRC 35 and 32.
The rings, which were fitted to the casing with negative allowances as shown in Table 1, got compressed and hardened to a state of plastic deformation (compression deformation) exceeding their material yield strengths.
TABLE 1
Negative
Die core 3
Casing 1
Ring 2
allowance
Tested
D 3
H 3
D
D 1
H 1
h 1
hardness,
D 2
d 2
hardness
δ 1
δ 2
die
(mm)
(mm)
(mm)
(mm)
(mm)
(mm)
(HRC)
(mm)
(mm)
(HRC)
(mm)
(mm)
1
22
20
7.5-0.1
48
36
24
42
26.4
21.5
35
0.5
0.185
2
20
17
6.5-0.1
43
32
22
40
23.6
19.5
32
0.4
0.174
Their die cores were all made of hard alloy WCO 8 with the hardness of HRA 88. Their entrance opening 10 of the core was tapered at an angle of 16°, the exit opening 7 was tapered at 40°, dimensions of the bearing zone were 3 and 2.5 mm respectively.
If the outer diameter D 2 was given, the inner diameter d 1 of the casing 1 , was δ 1 shorter.
The mating geometrical feature of the ring and the die core was tapered at an angle of 1.95°.
The two dies were then press-fitted with negative allowance of δ 2 . As a result, the die cores were safely assembled in the rings and hardened via 2100 Mpa compression stress exceeding the elastic strength of WCO8 and, thus, they were in a state of deformation favorable for die capability. With higher strength of the casing, press-fitting were safely accomplished.
Evaluation of operational capabilities of the two tested dies in drawing the steel 40 are shown in Table 2.
TABLE 2
Drawing Condition
Metal stock
Drawing
Drawed
Drawing
Tested
diameter,
speed,
amount,
force,
Abrasion
die
(mm)
Material
Ovality
lubricant
(m/min)
(t)
(t)
(mm)
1
8.5
Steel 40
0.02
Neutral
100
30
0.86
0.03
soap
2
7.5
Steel 40
0.003
Neutral
100
38
0.6
0.045
soap
As shown in the table, when 30 t of steel 40 with 8.5 mm diameter was drawn by 7.5 mm die, the core was worn by 0.03 mm in diameter and not fractured. When 38 t of steel 40 with 7.5 mm diameter was drawn by 6.5 mm die, the core was worn by 0.045 mm in diameter and not fractured. | The present invention provides a novel die assembly for extruding and drawing ferrous and non-ferrous metal, and also to a method of making the same. The die assembly according to the present invention comprises a die core ( 3 ); at least one pre-stressed ring ( 2 ) placed around the die core ( 3 ); and a die casing ( 1 ) surrounding the ring ( 2 ), wherein the ring ( 2 ) is plastically deformed and hardened by press fitting it to the casing ( 1 ) so that the ring has compression stress exceeding its material yield limit by 10-40%, and the mating geometric feature ( 5 ) of the core and the ring is tapered towards the exit, to thereby obtain a rigid container system in which a die core can be press fitted with a great force without die cracking. As a result, a long lasting die assembly with surprisingly high performance, small dimension and low production cost is obtained by assembling the die core by a great force without die cracking. | 1 |
BACKGROUND OF THE INVENTION
Low dielectric constant materials are used as interlayer dielectrics in microelectronic devices, such as semiconductor devices, to reduce the RC delay and improve device performance. As device sizes continue to shrink, the dielectric constant of the material between metal lines must also decrease to maintain the improvement. Certain low-k materials have been proposed, including various carbon-containing materials such as organic polymers and carbon-doped oxides. Although such materials may serve to lower the dielectric constant, they may offer inferior mechanical properties such as poor strength and low fracture toughness. The eventual limit for a dielectric constant is k=1, which is the value for a vacuum. Methods and structures have been proposed to incorporate void spaces or “air gaps” in attempts to obtain dielectric constants closer to k=1. One major issue facing air gap technology is how to remove sacrificial material to facilitate multi-layer structures. Another major issue facing air gap technology is how to facilitate air gap creation while providing a structure which can withstand modern processing steps, such as chemical-mechanical polishing and thermal treatment, as well as post processing mechanical and thermo-mechanical rigors.
Accordingly, there is a need for a microelectronic device structure incorporating air gaps which has low-k dielectric properties, can be used in multi-layer structures, and has acceptable mechanical characteristics during and after processing.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is illustrated by way of example and is not limited in the figures of the accompanying drawings, in which like references indicate similar elements. Features shown in the drawings are not intended to be drawn to scale, nor are they intended to be shown in precise positional relationship.
FIGS. 1A-1I depict cross-sectional views of various aspects of an embodiment of the present invention wherein a sacrificial dielectric layer is decomposed to form a volatile gas which forms deposits around an exhaust vent, the deposits at least partially occluding the exhaust vent.
FIGS. 2A-2H depict cross-sectional views of various aspects of another embodiment of the present invention having at least one additional dielectric layer disposed between the sacrificial dielectric layer and the substrate layer.
DETAILED DESCRIPTION
In the following detailed description of embodiments of the invention, reference is made to the accompanying drawings in which like references indicate similar elements. The illustrative embodiments described herein are disclosed in sufficient detail to enable those skilled in the art to practice the invention. The following detailed description is therefore not to be taken in a limiting sense, and the scope of the invention is defined only by the appended claims.
Referring to FIG. 1A , a cross-sectional view of a microelectronic structure is shown having a substrate layer ( 100 ) adjacent a first dielectric layer ( 102 ), which is depicted adjacent a sacrificial dielectric layer ( 104 ). The sacrificial dielectric layer ( 104 ), selected for its relatively low dielectric constant, controllable dissolution or decomposition characteristics, compatibility with adjacent materials, and mechanical properties, is positioned between the first dielectric layer ( 102 ) and a second dielectric layer ( 106 ) in one direction, and between two conductive layers ( 108 , 110 ) in a substantially perpendicular direction, as is convention for semiconductor interconnect structures. Relatively simple structures such as the one depicted in FIG. 1A are well known in semiconductor processing, and are produced using conventional techniques, depending upon the materials selected.
The substrate layer ( 100 ) may be any surface generated when making an integrated circuit, upon which a conductive layer may be formed. The substrate layer ( 100 ) thus may comprise, for example, active and passive devices that are formed on a silicon wafer, such as transistors, capacitors, resistors, diffused junctions, gate electrodes, local interconnects, etcetera. The substrate layer ( 100 ) may also comprise insulating materials (e.g., silicon dioxide, either undoped or doped with phosphorus or boron and phosphorus; silicon nitride; silicon oxynitride; or a polymer) that separate active and passive devices from the conductive layer or layers that are formed adjacent them, and may comprise other previously formed conductive layers.
A first dielectric layer ( 102 ) may be integrated to protect, isolate, and/or provide etch stop functionality adjacent the substrate layer ( 100 ). Referring to FIG. 1A , the first dielectric layer ( 102 ) preferably comprises a material, such as silicon nitride or other known etch stop material appropriately matched with the etchability of adjacent layers, which selectively does not substantially etch when the layer above ( 104 ) is being etched. Other ceramic and glass materials conventionally employed as etch stops also are suitable, and materials for the first dielectric layer ( 102 ) preferably have thermal decomposition temperatures higher than about 500 degrees, Celsius. The first dielectric layer ( 102 ) may be deposited using conventional chemical vapor deposition (“CVD”), plasma enhanced CVD, or low-pressure CVD techniques, as are well known in the art, in a layer preferably a thickness between about 10 nanometers and about 200 nanometers.
The sacrificial dielectric layer ( 104 ), depicted in FIG. 1A between the first dielectric layer ( 102 ) and the second dielectric layer ( 106 ), is denominated “sacrificial” because it is selected for removability, at least in part, from the volume it occupies as depicted in FIGS. 1A-1D . The sacrificial layer ( 104 ) preferably has a thickness between about 10 nanometers and about 2,000 nanometers. Preferred sacrificial dielectric layers comprise organic polymeric materials including but not limited to polynorbomene; cross-linked photoresist; photosensitive polyimide; polyarylene-based dielectrics such as those sold under the tradenames “SiLK™” and “GX-3™”, distributed by Dow Chemical Corporation and Honeywell Corporation, respectively; and poly(aryl ether)-based materials such as that sold under the tradename “FLARE™”, distributed by Honeywell Corporation. Polyarylene-based materials, such as SiLK™, and poly(aryl ether)-based materials, such as FLARE™, may have thermal decomposition temperatures of about 450 degrees Celsius. Variants of polynorbornene and polyimide, which generally have a thermal decomposition temperature of about 400 degrees Celsius, are available from suppliers such as Tokyo Ohka Kogyo Corporation and JSR Corporation. As would be apparent to one skilled in the art, photoresist may comprise a polynorbornene polymer backbone with photo-acid generating groups (“PAGs”) based on phenyl-sulfonates which are tuned to specific wavelengths of radiation by adding various substituents, while photosensitive polyimide may comprise a polyimide backbone with appropriate PAGs. The sacrificial dielectric layer ( 104 ) may be formed using conventional deposition techniques such as spin-on for suitable polymers, conventional CVD, or physical vapor deposition (“PVD”).
Referring to FIG. 1A , each of the conductive layers ( 108 , 110 ), comprising materials conventionally used to form conductive layers in integrated circuits, and preferably comprising metals such as copper, aluminum, and alloys thereof, is formed using known techniques. For example, the depicted conductive layers ( 108 , 110 ) may be formed using known dual damascene techniques, wherein a trench is formed using conventional lithography, etching, and cleaning techniques, the trench having a via portion ( 140 ) and a line portion ( 138 ). The trench may then be lined with a barrier layer (not shown) to isolate conductive material, after which the trench is filled with a conductive material using, for example, known electroplating, electroless plating, chemical vapor deposition, or physical deposition techniques, to form the conductive layers ( 108 , 110 ) shown. Alternatively, the conductive layers ( 108 , 110 ) may be formed using known subtractive metallization techniques, wherein a larger layer of conductive material is etched away to form conductive layers which are electrically isolated from one another, as are the specimens depicted in FIG. 1 A. The resultant interconnect structure has conductive layers ( 108 , 110 ) positioned between the sacrificial dielectric layer ( 104 ). Alternatively, conductive layers ( 108 , 110 ) may be made from doped polysilicon or a silicide, e.g., a silicide comprising tungsten, titanium, nickel, or cobalt, using known techniques. The conductive layers ( 108 , 110 ) preferably have line widths between about 10 nanometers and about 2,000 nanometers. The spacing between the conductive layers ( 108 , 110 ) may vary with the feature size of the microelectronic structure as would be apparent to one skilled in the art, and is related to the volume of sacrificial material per each exhaust vent, as is discussed below in reference to FIG. 1 G. Preferably the spacing is between about 20 nanometers and about 1,000 nanometers. Depending upon the selected conductive material, a shunt layer may be formed over the conductive layers using conventional techniques and materials, to isolate the conductive layers from subsequent treatments and materials. With copper metal conductive layers, a metal shunt layer comprising, for example, cobalt or tungsten, is effective for isolating the copper. The shunt material (not shown) is deposited using conventional techniques such as chemical vapor deposition, subsequent to a planarization using known techniques such as chemical-mechanical planarization (hereinafter “CMP”). Shunt material deposited upon the exposed portions of the sacrificial dielectric layer ( 104 ) may be removed using subsequent CMP or etch back, as would be apparent to those skilled in the art.
Subsequent to formation of the conductive layers ( 108 , 110 ), a second dielectric layer ( 106 ) is formed. Preferably the second dielectric layer ( 106 ) is not a “sacrificial” layer, in that it remains substantially intact during subsequent decomposition or dissolution and removal treatments which modify the sacrificial dielectric layer ( 104 ), with the exception that an exhaust vent, as described in further detail below, may be defined across the second dielectric layer ( 106 ) to facilitate removal of portions of the sacrificial dielectric layer ( 104 ). The second dielectric layer ( 106 ) preferably comprises a material, such as silicon nitride other known etch stop material appropriately matched with the etchability of adjacent layers, which selectively does not substantially etch when a subsequently-formed layers is being etched. Other suitable materials include but are not limited to silicon carbide, silicon dioxide, carbon doped oxides, as further described below, and other ceramics or amorphous glasses, such as aluminosilicate, which have relatively high thermal decomposition temperatures in the ranges over 500 degrees Celsius. The high thermal decomposition temperatures of preferred materials for the second dielectric layer ( 106 ) facilitate thermal decomposition and removal of associated sacrificial materials without thermal decomposition of the second dielectric layer ( 106 ). The second dielectric layer ( 106 ) may be deposited using conventional chemical vapor deposition (“CVD”), plasma enhanced CVD, or low-pressure CVD techniques, as are well known in the art. The second dielectric layer ( 106 ) is preferably between about 10 nanometers and about 500 nanometers in thickness.
Referring to FIG. 1B , a structure similar to that depicted in FIG. 1A is shown, with the exception that an etching pattern layer ( 112 ) has been formed adjacent the second dielectric layer ( 106 ), the etching pattern layer ( 112 ) preferably comprising conventional photoresist material formed and patterned using known lithography techniques. Referring to FIG. 1C , trenches ( 114 ) are etched to the sacrificial dielectric layer ( 104 ) employing the etching pattern layer ( 112 ) and appropriately selective etching techniques, such as conventional acid-based wet etching or plasma-enhanced dry etching. The trenches ( 114 ) define exhaust vents ( 118 ), which may be used to facilitate removal of portions of the sacrificial dielectric layer ( 104 ), as described below. As shown in FIG. 1D , the etching pattern layer ( 112 ) previously depicted in FIG. 1C has been removed, preferably using known ashing or polishing techniques, leaving the second dielectric layer ( 106 ), with exhaust vents ( 118 ) defined therethrough, exposed. In another embodiment, the etching pattern layer ( 112 ) is left intact to be ashed during a subsequent thermal decomposition treatment, described below, to streamline the overall process.
Referring to FIG. 1E , a closer cross-sectional view of the microelectronic structure is depicted wherein a transformation is partially depicted. As shown in FIG. 1E , a volatile gas ( 199 ), comprising at least a portion of the sacrificial dielectric layer ( 104 in FIGS. 1A-1E ) in thermally decomposed form, escapes through an exhaust vent ( 118 ) along an escape pathway ( 124 ) defined by the exhaust vent ( 118 ). As the volatile gas passes by the portions of the second dielectric layer ( 106 ) which define the exhaust vent ( 118 ), residue ( 122 ) accumulates. The accumulated residue ( 122 ) decreases the size of the exhaust vent ( 118 ), eventually forming a plug ( 126 ), as depicted in FIG. 1 F. The plug ( 126 ) isolates the void ( 144 ) from the environment opposite the second dielectric layer ( 106 ) by at least partially, and preferably substantially completely occluding, or blocking, the exhaust vent to a degree enabling subsequent layers to be deposited upon the surface defined by the plug ( 126 ) and second dielectric layer ( 106 ) without substantial infilling of the adjacently positioned air gap or void ( 144 ). The fit or seal provided between the plug ( 106 ) and second dielectric layer ( 106 ) need not be perfect or hermetic to achieve this objective, given the viscosity, particle size, and other relevant properties of materials commonly used in such positions. As shown in FIG. 1F , the result is a void ( 144 ) confined cross-sectionally by the substrate layer ( 100 ) or first dielectric layer ( 102 ), the conductive layers ( 108 , 110 ), the second dielectric layer ( 106 ), and the plug ( 126 ).
Thermal processing is a critical aspect to the successful formation of structures like those depicted in FIGS. 1E and 1F . In particular, at least a portion of the intact sacrificial dielectric layer ( 104 ), as shown in FIG. 1D , must be decomposed without substantial decomposition of surrounding structures such as the first and second dielectric layers ( 102 , 106 ), barrier layers which may be present (not shown), or adjacent conductive layers ( 108 , 110 ). Generally this is accomplished by selecting a sacrificial dielectric layer material having a lower thermal decomposition temperature threshold than suitable materials for surrounding structures, to enable heating past the decomposition temperature of the sacrificial dielectric layer material, which also is below the thermal decomposition thresholds for adjacent materials. The aforementioned preferred sacrificial dielectric materials, for example, have thermal decomposition temperatures between about 400 and about 450 degrees Celsuis, while the preferred second dielectric layer materials thermally decompose at temperatures above 500 degrees Celsius. The result of thermally decomposing at least a portion of the sacrificial dielectric layer ( 104 ) is a gas phase dielectric decomposition. When combined with a carrier plasma (not shown), such as an oxygen, hydrogen, or nitrogen rich plasma, as are known in the art for their reactivity and/or ability to act as carriers, a volatile gas ( 199 ) may be formed from the gas phase dielectric decomposition and carrier plasma, which deposits residue ( 122 ) around an exhaust vent ( 118 ) when exhausted through such a vent during a process of cooling from the temperature of formation of the volatile gas, substantially the same as the decomposition temperature for the material comprising the sacrificial dielectric layer ( 104 ), to room temperature, or about 25 degrees Celsius. Cooling the environment around the volatile gas preferably occurs by removing the heated structure, including the volatile gas, from heating chamber and exposing it to room temperature. In other words, taking such a structure out of the oven and into a laboratory atmosphere generally is enough of a temperature transformation to cause high-speed exhausting of the volatile gas ( 199 ) through the exhaust vent ( 118 ), as residue ( 122 ) is concomitantly formed into a plug ( 126 ), and at least one air gap or void ( 144 ) occupying the volume ( 105 ) previously occupied by the intact sacrificial dielectric layer ( 104 ) is defined. As is further described below, the embodiment of the exhaust vent depicted in FIGS. 1D and 1G , for example, defines a substantially cylindrical geometry. With this exhaust geometry, the plug ( 126 ), as shown in FIG. 1F , preferably has a substantially cylindrical shape where confined by the second dielectric layer ( 106 ), and may have a substantially convex top surface ( 150 ) and a stem-shaped bottom surface ( 152 ) due to the deposition pattern of the exhausting volatile gas. The plug ( 126 ) and residue ( 122 ) preferably comprise the same material as the sacrificial dielectric layer ( 104 ), although modifications may occur during the carrier plasma treatment depending upon locally available precursors, as would be apparent to one skilled in the art.
As shown in FIG. 1F , a plug ( 126 ) may have a greater thickness than that ( 146 ) of the associated second dielectric layer ( 106 ). Such a geometric discrepancy subsequently may be remedied with known planarization techniques, such as CMP, before or after formation of additional adjacent layers. Additional layers preferably are formed upon the second dielectric layer ( 106 ) and plug ( 126 ) before any planarization of the plug ( 126 ), since one of the primary reasons for forming a plug ( 126 ) is to establish a subsequent layer above an air gap ( 144 ), and planarization may cause the plug ( 126 ) to be repositioned in an orientation or position unfavorable in terms of subsequent layer formation and retention of the air gap ( 144 ).
Referring to FIG. 1G , a notion of allocated volume of sacrificial dielectric material, per exhaust vent, is introduced. The microelectronic structure, shown in top view cross section, via a plane perpendicular to that of the plane of FIG. 1F , has three exhaust vents spaced apart approximately equally. In this variation, each exhaust vent ( 118 ) has a substantially cylindrical ( 128 ) three-dimensional geometry, as may be achieved using conventional etching procedures such as those employed for creating via trenches having substantially circular geometries. A representation of the total sacrificial dielectric material volume is outlined with a dashed line ( 130 ). A line of larger dashes ( 134 ) outlines approximately ⅓ of such volume ( 130 ), which is associated by geometry and fluid dynamics, assuming similar associated materials and processing schedules, with the center vent ( 132 ). The sacrificial material allocatable to the center vent ( 132 ) should be at least the same volume as the volume defined by the vent itself, in this case a cylindrical vent volume ( 128 ), or the chances of occlusion during the aforementioned processing is unlikely. In other words, the sacrificial material allocatable based upon factors such as heating, geometry, and fluid dynamics factors, must be voluminous enough to fill the vent volume, or occlusion may not be accomplished. Fluid dynamics factors, such as greater fluid pass-through restriction in certain adjacent vents, geometric factors, such as nonuniform vent geometry, or nonuniform heating and/or cooling, are likely to have significant affect on such a model, as would be obvious to one skilled in the art. Adjacent vent geometries preferably are substantially uniform, as is thermodynamic treatment and relevant geometry, and exhaust vents with substantially cylindrical shapes preferably have diameters between about 200 nanometers and about 500 nanometers. Substantially complete occlusion may be preferable for structural integrity of the layer comprising the second dielectric layer and associated plugs, and may also be preferred for sealing the voids ( 144 ) created from other surrounding materials and environmental factors.
Referring to FIGS. 1H and 1L , two variations of an embodiment of the invention wherein some residual sacrificial dielectric material ( 136 , 142 ) remains located in the volume previously occupied ( 105 ) by the intact sacrificial layer ( 104 in FIGS. 1 A- 1 D). Such residual sacrificial dielectric material generally is the result of an allocatable volume of sacrificial dielectric material which is larger than that which is needed to form a plug ( 126 ) in the pertinent vent.
As shown in FIG. 1H , the residual sacrificial dielectric material ( 136 ) forms a layer positioned between the first dielectric layer ( 102 ) and a void ( 144 ), and between the two conductive layers ( 108 , 110 ), the layer being substantially segregated from the void ( 144 ) within the volume previously occupied by the intact sacrificial dielectric layer ( 104 in FIGS. 1 A- 1 D), and being formed as a result of a plasma-assisted thermal decomposition wherein a portion of the sacrificial dielectric material is dry etched during heating, which improves reactivity with the carrier plasma and creates a relatively low temperature thermal decomposition, at a temperature not substantially greater than the thermal decomposition temperature for the sacrificial dielectric material. With such as scenario, the plasma reacts with the most immediately exposed surfaces of the sacrificial dielectric material ( 136 ) first, creating a concave surface into the residual sacrificial dielectric material ( 136 ) as shown, then gradually works through the first dielectric layer ( 102 ) toward the substrate layer ( 100 ), producing volatile gas ( 199 in FIG. 1 E), which escapes and concomitantly contributes to the formation of a plug ( 126 ). The layer formed by the residual sacrificial dielectric material ( 136 ) preferably is between about 10 nanometers and about 1,000 nanometers with such an embodiment. As shown in FIG. 1H , portions of the residual sacrificial dielectric material ( 136 ) may be substantially aligned with the via portions ( 140 ) of the conductive members, while the void ( 144 ) is substantially aligned with the line portions ( 138 ). Such a construction may be desirable since the via portions, relatively unstable due to their geometry, are supported by adjacent solid material, and since the highly conductive line portions ( 138 ) are positioned adjacent the low-k dielectric properties of the void ( 144 ).
Referring to FIG. 1I , a variation is depicted wherein the residual sacrificial dielectric material ( 142 ), substantially segregated from the void ( 144 ) within the volume previously occupied by the intact sacrificial dielectric layer ( 104 in FIGS. 1 A- 1 D), is positioned substantially evenly about the borders of the volume, preferably with a thickness between about 10 nanometers and about 100 nanometers. Such a variation may be formed by rapidly quenching a thermally-driven volatile gas ( 199 in FIG. 1E ) to room temperature in a manner wherein portions of the volatile gas condensate upon the adjacent solid surfaces, such as the surfaces of conductive layers and other dielectric layers, because the adjacent solid surfaces would cool faster than the region no longer occupied by a solid. A centrally located air gap ( 144 ) results, providing low-k dielectric benefits along the associated lengths of conductive members ( 108 , 110 ), as well as some support of the associated structures through the thin layer comprising the residual sacrificial dielectric material ( 142 ).
Referring to FIGS. 2A-2H , an analog of the structures and processes described in reference to FIG. 1 are presented, with FIGS. 2A-2H paralleling FIGS. 1A-1F and 1 H- 1 I and like references indicating similar elements. Referring to FIG. 2A , the depicted structure varies from that of FIG. 1A in that a third dielectric layer ( 248 ) is disposed between the first dielectric layer ( 102 ) and the sacrificial dielectric layer ( 104 ), which is decreased in geometry in this variation to provide room for the third dielectric layer ( 248 ). In the depicted variation, the third dielectric layer ( 248 ) is positioned adjacent via portions ( 140 ) of the conductive layers and not adjacent to the line portions ( 138 ). In a similar manner as with the residual sacrificial dielectric material ( 136 ) of FIG. 1H , such a geometric configuration may be desirable because support is provided to the narrowed via portions ( 140 ), which may be more susceptible to undesirable bending or deformation due to their smaller relative size, while the highly-conductive line portions ( 138 ) are more likely surrounded by a void or voids resulting from the decomposition and removal of a portion of the sacrificial dielectric layer ( 104 ).
The third dielectric layer ( 248 ) may comprise any material that may insulate one conductive layer from another, and preferably comprises a dielectric material having a higher thermal decomposition temperature than that of the sacrificial dielectric layer ( 104 ) with which it is paired. For example, the third dielectric layer may comprise silicon dioxide (either undoped or doped with phosphorus or boron and phosphorus); silicon nitride; silicon oxy-nitride; porous oxide; an organic containing silicon oxide; fluorine silicate glass (“FSG”), or a polymer. Preferred are polymers or carbon doped oxides, as further described below, with a low dielectric constant: preferably less than about 3.5 and more preferably between about 1.5 and about 3.0. When other adjacent dielectric layers comprise materials having a low dielectric constants, the capacitance between various conductive elements that are separated by such layers should be reduced, when compared to the capacitance resulting from use of other conventionally used dielectric materials such as silicon dioxide. Such reduced capacitance may decrease the RC delay that would otherwise exist and may also decrease undesirable cross-talk between conductive lines.
The third dielectric layer ( 248 ) may comprise an organic polymer selected from the group consisting of polyimide, polyarylene, poly(aryl ether), organosilicate, polynaphthalene, and polyquinoline, or copolymers thereof. When the third dielectric layer ( 248 ) comprises a polymer, it is preferably formed by spin coating or chemical vapor depositing the polymer onto the surface of the first dielectric layer ( 102 ), using conventional equipment and process treatments.
The third dielectric layer ( 248 ) may alternatively comprise a compound having the molecular structure Si x O y R z , in which R is selected from the group consisting of hydrogen, carbon, an aliphatic hydrocarbon and an aromatic hydrocarbon. When “R” is an alkyl or aryl group, the resulting composition is often referred to as carbon-doped oxide (“CDO”). When the third dielectric layer ( 248 ) comprises a carbon-doped oxide, it preferably comprises between about 5 and about 50 atom % carbon. More preferably, such a compound includes about 15 atom % carbon.
Examples of other types of materials that may be used to form the third dielectric layer ( 248 ) include aerogel, xerogel, and spin-on-glass (“SOG”). In addition, the third dielectric layer ( 248 ) may comprise either hydrogen silsesquioxane (“HSQ”), methyl silsesquioxane (“MSQ”), or other materials having the molecular structure specified above, which may be coated onto the surface of a semiconductor wafer using a conventional spin coating process. Although spin coating may be a preferred way to form the third dielectric layer ( 248 ) for some materials, for others chemical vapor deposition, plasma enhanced chemical vapor deposition, a SolGel process, or foaming techniques may be preferred. The third dielectric layer ( 248 ) preferably has a thickness between about 10 nanometers and about 500 nanometers.
Referring to Figures and 2 B, after the third dielectric layer ( 248 ) has been formed adjacent the first dielectric layer, subsequent formation of the sacrificial dielectric layer ( 104 ), conductive layers ( 108 , 110 ), second dielectric layer ( 106 ), and etching pattern layer ( 112 ) proceeds as described above using conventional techniques. In reference to FIGS. 2C and 2D , trenching ( 114 ) to define each vent ( 118 ) also proceeds as described above.
As depicted in FIG. 2E , subsequent to thermal decomposition of at least a portion of the sacrificial dielectric layer ( 104 ), and introduction of a carrier plasma (not shown), such as a hydrogen, nitrogen, or oxygen rich plasma, a volatile gas is formed ( 199 ) which escapes during cooling, forming residue ( 122 ) around the exhaust vent ( 118 ), to preferably result in a structure such as that depicted in FIG. 2F , wherein at least one void ( 144 ) is positioned within the volume previously occupied ( 105 ) by the sacrificial dielectric material, the void being isolated by a plug ( 126 ) through the second dielectric layer ( 106 ) from the environment opposite the second dielectric layer ( 106 ). In a similar manner to that of the variations of FIGS. 1H and 1I , residual portions ( 136 , 142 ) may continue to occupy portions of the volume previously occupied ( 105 ) by the intact sacrificial dielectric layer ( 104 ), and may form shapes such as those depicted in FIGS. 2G and 2H ( 136 , 142 , respectively).
Thus, a novel dielectric solution is disclosed. Although the invention is described herein with reference to specific embodiments, many modifications therein will readily occur to those of ordinary skill in the art. Accordingly, all such variations and modifications are included within the intended scope of the invention as defined by the following claims. | A low-k dielectric sacrificial material is formed within a microelectronic structure covered with a layer defining an exhaust vent. At an appropriate time, the underlying sacrificial material is decomposed and exhausted away through the exhaust vent. Residue from the exhausted sacrificial material accumulates at the vent location during exhaustion until the vent is substantially occluded. As a result, an air gap is created having desirable characteristics as a dielectric. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to liposome preparations and more particularly, to liposome preparations comprising cholesterol derivatives having a negative charge as a liposome membrane constituent, in which Adriamycin is entrappped. The preparations are utilized in the medical field.
2. Statement of the Prior Art
Adriamycin has been widely used as an anti-tumor agent. Due to its positive charge in physiological pH region, however, Adriamycin encounters problems that Adriamycin binds to membrane constituents such as cells, mitochondria, etc., especially to phospholipids negatively charged, thus leading to accumulative cardiotoxicity as a cause therefor. Accordingly, its dosage is limited. In addition, Adriamycin has a high affinity to vital tissues so that even when it is intravenously administered, Adriamycin rapidly disappears out of blood.
In order to solve the foregoing problems, there are provided Adriamycin-entrapped liposome preparations in which acidic glycolipids such as Sulfatides having a negative charge in a physiological pH region, or glycolipids having a sulfo group, especially Sulfatides (Japanese Patent Application Laid-Open Nos. 62-129221 and 63-112512).
On the other hand, in Adriamycin-entrapped liposome preparations, it is known to use sterols having a negative charge such as cholesterol sulfate and cholesterol hemisuccinate as the liposome membrane constituent (International Patent Application No. PCT/US88/01573 : International Publication No. W088/09168).
The aforesaid liposome preparations obtained by incorporating Sulfatide into the liposome membrane constituent exhibit effects that they have a high content of Adriamycin to keep a high blood level of Adriamycin over a long period of time and less accumulate Adriamycin on the heart, as compared to the case where Adriamycin is administered in an aqueous solution and therefore, cardiotoxicity can be reduced.
However, it has not yet been established to chemically synthesize Sulfatides, but they are obtained by extracting and purifying from animal, e.g., bovine brain.
For this reason, it is difficult to obtain pure compounds. In addition, extraction and purification take much time. In the case of utilizing commercially available compounds, costs are extremely high. Thus, there was a problem that liposome preparations containing these components as liposome membrane constituents could not be produced in large quantities from an industrial viewpoint.
As a result of extensive investigations on liposome membrane constituents which can be easily synthesized at low costs, the present inventors have found that cholesterol derivatives having a negative charge and represented by general formula:
R--CO--A.sub.1
(wherein R represents a cholesterol residue, and A 1 represents an amino acid residue), and represented by general formula:
R--A.sub.2
(wherein R represents a cholesterol residue, and A 2 represents a fatty acid residue), had effects equivalent to Sulfatide.
That is, it has been found that Adriamycin-entrapped liposome preparations comprising these cholesterol derivatives having a negative charge as liposome membrane constituents have a high content of Adriamycin and when administered in a living body, can maintain high blood level of Adriamycin over a long period of time, reduce distribution of Adriamycin on the heart and reduce systemic toxicity. The present invention has thus been completed.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
In the present specification, the cholesterol residue refers to a group obtained by removing hydrogen atom from the hydroxy group at the 3-position of cholesterol, and the amino acid residue refers to a group obtained by removing one hydrogen atom from the amino moiety of an amino acid. The fatty acid residue refers to a group obtained by removing one hydrogen atom from the hydrocarbon moiety of a fatty acid.
As the amino acid, an aliphatic amino acid is preferred. Among them, particularly preferred are a monoamino-monocarboxylic acid (for example, glycine, alanine, etc.) and a monoaminodicarboxylic acid (for example, aspartic acid, glutamic acid, etc.).
As the fatty acid, a lower fatty acid having 2 to 7 carbon atoms (for example, propionic acid, butyric acid, etc.) is preferred.
Examples of the cholesterol derivatives represented by general formula:
R--CO--A.sub.1
(wherein R and A 1 have the same significances as described above) include:
N-(cholest-5-ene-3β-oxycarbonyl)glycine,
N-(cholest-5-ene-3β-oxycarbonyl)glycylglycine,
N-(cholest-5-ene-3β-oxycarbonyl)glycylglycylglycine,
N-(cholest-5-ene-3β-oxycarbonyl)-β-alanine,
N-(cholest-5-ene-3β-oxycarbonyl)-6-amino-n-caproic acid,
N (cholest-5-ene-3β-oxycarbonyl)-4-aminomethylbenzoic acid,
N-(cholest-5-ene-3β-oxycarbonyl)-4-aminophenylacetic acid,
N-(cholest-5-ene-3β-oxycarbonyl)-β-alanyl-β-alanine,
N-(cholest-5-ene-3β-oxycarbonyl)-β-alanyl-β-alanyl-β-alanine,
N-(cholest-5-ene-3β-oxycarbonyl)-β-alanyl-glycine,
N-(cholest-5-ene-3β-oxycarbonyl)phenylalanine,
N-(cholest 5-ene-3β-oxycarbonyl)aspartic acid, etc.
Examples of the cholesterol derivatives represented by general formula:
R--A.sub.2
(wherein R and A 2 have the same significances as described above) include cholest-5-ene-3β-oxyacetic acid, cholest-5-ene-3β-oxypropionic acid, cholest-5-ene-3β-oxybutyric acid, etc.
Of these cholesterol derivatives, the cholesterol derivatives represented by general formula:
R--CO--A.sub.1
(wherein R and A 1 have the same significances as described above) can be prepared, for example, by reacting reactive derivatives at the 3-hydroxy group of cholesterol with amino acid compounds.
As the reactive derivatives at the 3-hydroxy group of cholesterol, there are compounds in which the hydroxy group is converted into an acid residue, for example, a haloformyloxy (e.g., chloroformyloxy, etc.).
The reaction is generally carried out in a conventional solvent such as methanol, ethanol, acetone, dioxan, acetonitrile, chloroform, methylene chloride, ethylene chloride, tetrahydrofuran, ethyl acetate, N,N-dimethylformamide, pyridine, etc. The reaction may be carried out in any other solvent as far as the solvent is inert to the reaction. These conventional solvents may be used as admixture with water.
The reaction may also be carried out in the presence of an inorganic base or an organic base such as alkali metal hydrogencarbonate (e.g., sodium hydrogen-carbonate, etc.), tri(lower)alkylamine (e.g., trimethylamine, triethylamine, etc.), pyridine, N-(lower)alkylmorpholine, N,N-di(lower)alkylbenzylamine, etc. The reaction temperature is not particularly limited; in general, the reaction is carried out under cooling or at normal temperature.
Furthermore, the cholesterol derivatives represented by general formula:
R--A.sub.2
wherein R and A 2 have the same significances as described above) can be prepared in accordance with the process described in Aust. J. Chem., 24, 143-151 (1971).
As the phospholipid used as the liposome membrane constituent upon preparing the liposome preparation of the present invention, together with the cholesterol derivatives described above, there are phospholipids derived from yolk, soybean and other animal tissues such as phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, phosphatidylserine, sphingomyelin, etc., soybean lecithin which is a mixture of the phospholipids described above; and synthetic lecithin such as dipalmitoyllecithin, distearoyllecithin, etc.
In preparing the liposome preparation of this invention, it is desired to add the cholesterol derivative and Adriamycin in equimolar amounts. A constitutional molar ratio of the cholesterol derivative to the phospholipid in the liposome membrane constituents is approximately 1:1000 to 1:1.
In addition to the cholesterol derivative and the phospholipid, the liposome preparation of the present invention may appropriately contain ordinary additives, for example, cholesterol, dicetyl phosphate, α-tocopherol, etc.
The liposome preparation of the present invention can be prepared by known methods. That is, Adriamycin and the cholesterol derivative and the liposome membrane constituents such as phospholipids, additives, etc. are dissolved in a suitable solvent such as chloroform, methanol, ethanol, etc. The solution is charged in an appropriate vessel and the solvent is distilled off under reduced pressure. Next, a surfactant (e.g., sodium cholate, etc.) and an aqueous solution (e.g., phosphate buffered physiological saline, etc.) are added to the residue followed by shaking. After solubilizing the residue, the surfactant is removed from the solution using a device for removing surfactant. The liposome preparation can thus be prepared.
Alternatively, the liposome preparation can also be prepared by dissolving the liposome membrane constituents described above in an organic solvent such as chloroform, ethanol, etc., charging the solution in an appropriate vessel, distilling off the solvent under reduced pressure to form a thin membrane onto the inner surface of the vessel, then charging an aqueous solution of Adriamycin in the vessel, and shaking or performing sonication.
Furthermore, the liposome preparation can also be prepared by dissolving the liposome membrane constituents described above and Adriamycin in an organic solvent such as chloroform, ethanol, methanol, etc., charging the solution in an appropriate vessel, distilling off the solvent under reduced pressure to form a thin membrane onto the inner surface of the vessel, then charging phosphate buffer in the vessel, and shaking or performing sonication.
Furthermore, the liposome preparation may also be prepared in a conventional method such a ether injection method, etc. The method for preparing the liposome preparation of the present invention is not particularly limited.
The thus prepared liposome preparation of the present invention is administered, for example, by parenteral administration (e.g., intravenous injection, intramuscular injection, injection into tumor, etc.), oral administration, rectal administration, etc.
Hereafter the effects of the present invention are explained with reference to test examples.
TEST EXAMPLE 1
Method
The liposome suspensions prior to and after dialysis obtained in Examples 1 through 5 and Reference Example 1 later described were diluted with ethanol, respectively. An amount of Adriamycin was determined by high performance liquid chromatography (UV 254 nm) and the content of Adriamycin included was calculated by the following equation. ##EQU1##
TABLE 1______________________________________ResultsLiposome Preparation Amount of Adriamycin Entrapped______________________________________Example 1 84.8%Example 2 74.1%Example 3 51.1%Example 4 74.8%Example 5 83.8%Reference Example 1 20.0%______________________________________
In the liposome preparation of the present invention, the amount of Adriamycin entrapped is higher than the liposome preparation of Reference Example 1 (no cholesterol derivative was added).
TEST EXAMPLE 2
Method
A solution of Adriamycin in physiological saline (concentration: 2 mg/ml) and the liposome preparation obtained in Example 1 later described were administered to male ICR strain mice weighing 30 to 35 g from the tail vein, in doses of 20 mg/kg and 8 mg/kg, respectively, when calculated as Adriamycin. After a definite period of time, the heart was ectomized. The heart was washed with physiological saline and an amount of Adriamycin distributed was determined by a modification of the method described in Cancer Chemother. Rep., 54(2), 89-94 (1970).
TABLE 2______________________________________Results Distribution of Adriamycin in Heart (% of dose/tissue) 5 min. 15 min. 30 min. 4 hour.______________________________________Example 1 0.42 ± 0.02 0.30 ± 0.00 0.20 ± 0.01 0.18 ± 0.02Aqueous 0.77 ± 0.13 0.65 ± 0.01 0.76 ± 0.10 0.36 ± 0.03solution______________________________________ (n = 3, mean ± standard error)
When the liposome preparation of the present invention was administered, it is understood that distribution of Adriamycin in heart is prevented, as compared to the case of administering the aqueous solution.
TEST EXAMPLE 3
Method
A solution of Adriamycin in physiological saline (concentration; 2 mg/ml) and the liposome preparations obtained in Examples 1 through 4 later described were administered to SD strain male rats weighing 290 to 320 g from the femoral vein, in doses of 1 to 4 mg/kg, respectively, when calculated as Adriamycin. At each time point, blood was collected from the infraclavicular vein. Using 0.2 ml of whole blood, blood concentration of Adriamycin was determined by a modification of the method described in Cancer Chemother. Rep., 54(2), 89-94 (1970).
TABLE 3__________________________________________________________________________ResultsConcentration of Adriamycin in Whole Blood (% of dose/ml)2.5 min 5 min 15 min 30 min 1 hr 2 hr 4 hr 6 hr__________________________________________________________________________Example 1 3.196 ± 2.844 ± 2.159 ± 1.495 ± 0.880 ± 0.259 ± 0.072 ± 0.035 ± 0.333 0.167 0.218 0.139 0.097 0.039 0.010 0.009Example 2 3.383 ± 2.659 ± 1.679 ± 1.231 ± 0.816 ± 0.433 ± 0.165 ± 0.065 ± 0.217 0.177 0.150 0.116 0.089 0.062 0.036 0.016Example 3 2.661 ± 1.658 ± 0.772 ± 0.483 ± 0.316 ± 0.142 ± 0.049 ± 0.040 ± 0.011 0.100 0.126 0.079 0.065 0.029 0.010 0.002Example 4 2.046 ± 1.378 0.851 ± 0.527 ± 0.333 ± 0.170 ± 0.061 ± 0.030 ± 0.116 (n = 2) 0.178 0.119 0.086 0.046 0.031 0.015aqueous 0.640 ± 0.161 ± 0.042 ± 0.026 ± 0.018 ± 0.019 ± 0.014 ± 0.013 ±solution 0.032 0.010 0.001 0.001 0.001 0.001 0.000 0.001__________________________________________________________________________ (n = 2 to 4, mean ± standard error)
When the liposome preparation of the present invention was administered, it is understood that high blood concentration of Adriamycin can be maintained, as compared to the case of administering the aqueous solution.
TEST EXAMPLE 4
Method
A solution of Adriamycin in physiological saline (concentration: 2 mg/ml) and the liposome preparation obtained in Example 1 later described were administered to ICR strain male mice weighing 30 to 35 g from the tail vein, all in a dose of 32 mg/kg, when calculated as Adriamycin. A survival rate and body weight change of mice on Day 14 were observed and the results were compared with those obtained with mice for control group to which no Adriamycin was administered.
TABLE 4______________________________________Results Survival Body Weight Rate (%) Change (%)______________________________________Example 1 89 96.2Aqueous solution 30 85.2Control 100 116.9______________________________________
On Day 14 after the aqueous solution of Adriamycin, the survival rate of mice was reduced to 30% (3 out of 10 cases) and the body weight decreased to 85.2% prior to the administration; whereas on Day 14 after administration of the liposome preparation of this invention, the survival rate of mice was 89% (8 out of 9 cases) and the body weight showed 96.2%, indicating that the degree of decrease was small. It is noted from the results that systemic toxicity was alleviated.
REFERENCED EXAMPLE 1
After 10.9 ml of a solution of 37.5 μmoles of Adriamycin in methanol was charged in an Erlenmeyer's flask, the organic solvent was distilled off by an evaporator. Then 14.4 ml of a solution of 225.2 μmoles of yolk lecithin and 150 μmoles of cholesterol in chloroform was further charged in the flask. Chloroform was then distilled off by the evaporator.
After 10 ml of 0.01 M of phosphate buffered saline was added to the residue, the mixture was shaken to give a liposome suspension. The resulting liposome suspension was sequentially extruded through polycarbonate membranes (3.0, 1.0, 0.8, 0.6 and 0.4 μm). Thereafter, Adriamycin which was not entrapped in liposome was removed by dialysis in 0.001 M phosphate buffered saline at 4° C. for 48 to 72 hours. Thus, Adriamycin-entrapped liposome preparation was obtained.
Hereafter the present invention is described in more detail with reference to preparation examples and examples.
PREPARATION EXAMPLE 1
To a suspension of glycine (1.50 g) in water (100 ml) was added triethylamine (4.04 g). After dioxan (200 ml) and cholesteryl chloroformate (8.98 g) were added to the resulting clear solution at 0° C., the mixture was stirred for 3 hours. The reaction mixture was concentrated under reduced pressure and, 1 N hydrochloric acid (23 ml) and chloroform (100 ml) were added to the residue. The organic phase was separated and washed with water and then dried over magnesium sulfate. The solvent was distilled off to give crude crystals. After washing with ethanol, the crystals were filtered to give N-(cholest-5-ene-3β-oxycarbonyl)glycine (6.64 g) as white crystals.
Melting point: 175-177° C. (decomposed)
IR (nujol): 3320, 1750, 1665, 1570 cm -1
PREPARATION EXAMPLE 2
Sodium hydrogencarbonate (0.168 g) and tetrahydrofuran (20 ml) were added to a suspension of glycylglycine (0.15 g) in water (20 ml). After tetrahydrofuran (20 ml) and cholesteryl chloroformate (0.898 g) were added to the resulting transparent solution at 0° C., the mixture was stirred for an hour. The reaction mixture was concentrated under reduced pressure and, methanl (10 ml) and chloroform (10 ml) were added to the residue. By filtration, the transparent solution was obtained. The solvent was distilled off to give crude crystals (0.98 g). The crude crystals were then purified by silica gel chromatography to give N-(cholest-5-ene-3β-oxycarbonyl)glycylglycine (0.5 g) as white powders.
Melting point: 223-225° C (decomposed)
PREPARATION EXAMPLE 3
N-(Cholest-5-ene-3β-oxycarbonyl)glycylglycylglycine (0.41 g) was obtained as white powders in a manner similar to Preparation Example 2, except for using glycylglycylglycine (0.22 g) instead of glycylglycine (0.15 g).
Melting point: 235-239° C. (decomposed)
PREPARATION EXAMPLE 4
Sodium hydrogencarbonate (168 mg) was added to a solution of p-aminomethylbenzoic acid (303 mg) in a mixture of tetrahydrofuran (5 ml) and water (20 ml). Tetrahydrofuran (20 ml) and cholesteryl chloroforamate (898 mg) were added to the solution at 0° C. The mixture was stirred for 3 hours. The reaction mixture was concentrated under reduced pressure and, 1 N hydrochloric acid (30 ml) and chloroform (30 ml) were added to the residue. The organic phase was separated and washed with water and then dried over magnesium sulfate. The solvent was distilled off to give crude crystals. After washing with ethanol, the crystals were filtered to give N-(cholest-5-ene-3β-oxycarbonyl)-4-aminomethylbenzoic acid (500 mg) as white solids.
Melting point: 175-177° C. (decomposed)
PREPARATION EXAMPLE 5
The following compound was obtained in a manner similar to Preparation Example 4, except for using p-aminophenylacetic acid instead of p-aminomethylbenzoic acid. N-(cholest 5-ene-3β-oxycarbonyl)-4-aminophenylacetic acid (907 mg)
Melting point: 170-172° C. (decomposed)
PREPARATION EXAMPLE 6
Tetrahydrofuran (20 ml) and cholesteryl chloroformate (449 mg) were added to a solution of β-alanine (56 mg) and sodium hydrogencarbonate (84 mg) in water (10 ml) at 0° C. The mixture was stirred for an hour. The reaction mixture was concentrated under reduced pressure and, 0.1 N hydrochloric acid (10 ml) and chloroform (40 ml) were added to the residue. The organic phase was separated and washed with water and then dried over magnesium sulfate. The solvent was distilled off to give crude crystals. The crude crystals were dissolved in chloroform and the solution was subjected to silica gel column chromatography (40 g). Elution was performed with a mixture of chloroform and methanol to give N-(cholest-5-ene-3β-oxycarbonyβ-alanine (187 mg) as white powders.
Melting point : 127-130° C.
IR (chloroform); 3450, 1705 cm -1
PREPARATION EXAMPLE 7
Tetrahydrofuran (10 ml) and cholesteryl chloroformate (449 mg) were added to a solution of 6-amino-n-caproic acid (131 mg) and sodium hydrogencarbonate (84 mg) in a mixture of tetrahydrofuran (10 ml) and water (10 ml) at 0° C. Then, following the same procedures as in Preparation Example 6, N-(cholest-5-ene-3β-oxycarbonyl)-6-amino n-caproic acid (126 mg) was obtained as white powders.
IR (chloroform): 3440, 1700 cm -1
PREPARATION EXAMPLE 8
Cholest 5-ene-3β-oxyacetic acid (667 mg) was obtained in accordance with the method described in Aust. J. Chem., 24, 143-151 (1971).
Melting point: 160° C.
EXAMPLE 1
A solution (10.9 ml) containing 37.5 μmoles of Adriamycin in methanol and 25.9 ml of chloroform/methanol solution containing 37.5 μmoles of N-(cholest-5-ene-3β-oxycarbonyl)glycine were charged in an Erlenmeyer's flask. The organic solvent was distilled off by an evaporator. After 14.4 ml of chloroform solution containing 225.2 μmoles of yolk lecithin and 150 μmoles of cholesterol was further charged in the flask, chloroform was distilled off by the evaporator.
Next, 10 ml of 0.01 M phosphate buffered saline was added to the residue and the mixture was shaken to give the liposome suspension. The resulting liposome suspension was sequentially extruded through polycarbonate membranes (3.0, 1.0, 0.8, 0.6 and 0.4 μm). Thereafter, Adriamycin which was not entrapped in liposome was removed by dialysis in 0.001 M phosphate buffered saline at 4° C. for 48 to 72 hours. Thus, Adriamycin-entrapped liposome preparation was obtained.
EXAMPLE 2
Adriamycin-entrapped liposome preparation was obtained in a manner similar to Example 1, except for using 37.5 μmoles of N-(cholest-5-ene-3β-oxycarbonyl)glycyl-glycine in place of 37.5 μmoles of N-(cholest-5-ene-3β-oxycarbonyl)glycine of Example 1.
EXAMPLE 3
Adriamycin-entrapped liposome preparation was obtained in a manner similar to Example 1, except for using 37.5 μmoles of N-(cholest-5-ene-3β-oxycarbonyl)glycyl-glycylglycine in place of 37.5 μmoles of N-(cholest-5-ene-3β-oxycarbonyl)glycine of Example 1.
EXAMPLE 4
Adriamycin-entrapped liposome preparation was obtained in a manner similar to Example 1, except for using 37.5 μmoles of N-(cholest-5-ene-3β-oxycarbonyl)-4-amino-methylbenzoic acid in place of 37.5 μmoles of N-(cholest-5-ene-3β-oxycarbonyl)glycine of Example 1.
EXAMPLE 5
Adriamycin-entrapped liposome preparation was obtained in a manner similar to Example 1, except for using 37.5 μmoles of N-(cholest-5-ene-3β-oxycarbonyl)-4-aminophenylacetic acid in place of 37.5 μmoles of N-(cholest-5-ene-3β-oxycarbonyl)glycine of Example 1.
EXAMPLE 6
Adriamycin-entrapped liposome preparation was obtained in a manner similar to Example 1, except for using 37.5 μmoles of N-(cholest-5-ene-3β-oxycarbonyl)-β-alanine in place of 37.5 μmoles of N-(cholest-5-ene-3β-oxy-carbonyl)glycine of Example 1.
EXAMPLE 7
Adriamycin-entrapped liposome preparation was obtained in a manner similar to Example 1, except for using 37.5 μmoles of N-(cholest-5-ene-3β-oxycarbonyl)-6-amino-n-caproic acid in place of 37.5 μmoles of N-(cholest-5-ene-3β-oxycarbonyl)glycine of Example 1.
EXAMPLE 8
Adriamycin-entrapped liposome preparation was obtained in a manner similar to Example 1, except for using 37.5 μmoles of cholest-5-ene-3β-oxyacetic acid in place of 37.5 μmoles of N-(cholest-5-ene-3β-oxycarbonyl)glycine of Example 1.
While the invention has been described in detail and with reference to specific embodiments thereof, it is apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and the scope of the present invention. | The present invention relates to liposome preparations. In particular, the present invention relates to Adriamycin-entrapped liposome preparations comprising cholesterol derivatives having a negative charge as a liposome membrane constituent. Adriamycin-entrapped liposome preparations have many uses in the medical field such as maintaining high Adriamycin blood levels over a long period of time and reducing systemic toxicity, for example. | 0 |
PRIOR APPLICATION
This application is a U.S. national phase application based on International Application No. PCT/SE02/002330, filed 16 Dec. 2002, claiming priority from Swedish Patent Application No. 0104272-0, filed 17 Dec. 2001.
The present invention concerns a method and an arrangement for impregnating chips during the manufacture of chemical pulp.
THE PRIOR ART
During the cooking of chemical cellulose pulp with continuous digesters it has been conventional to use a pre-treatment arrangement with a chip bin, steaming vessel and an impregnating chip chute, before the cooking process is established in the digester. Steaming has been carried out in one or several steps in the chip bin, prior to the subsequent formation of a slurry of the chips in an impregnation fluid or a transport fluid. The steaming has been considered to be absolutely necessary in order to be certain of expelling the air and water that is bound in the chips, such that the impregnation fluid can fully penetrate the chips, and such that air is not drawn into the system. For example, U.S. Pat. No. 3,330,088 demonstrates the principle of such a system with a chip bin and a subsequent steaming vessel.
A great deal of development has taken place in order to optimise the steaming processin the chip bin, of which CA1154622, U.S. Pat. No. 6,199,299 and U.S. Pat. No. 6,284,095 only constitute examples of such development.
Attempts have been made to integrate the chip bin with the impregnation vessel in order to obtain in this manner a simpler system.
Already in U.S. Pat. No. 2,803,540, a system was revealed in which the chips from a chip bin were fed to a vessel in which a combined steaming and impregnation was achieved. In this vessel, the chips were steamed at the upper part of the vessel and impregnation fluid at the same temperature was added at various levels in the vessel.
These principles were applied in a process known as “Mumin cooking”, which is described in “Continuous Pulping Processes”, Technical Association of the Pulp and Paper Industry, 1970, Sven Rydholm, page 144. In this process, unsteamed chips were passed to a combined impregnation vessel, where steaming was obtained in the upper part, and to which impregnation fluid was added at a point in the upper part of the vessel during forced circulation. The impregnation fluid was in this case carried exclusively in the same direction of flow as the chips.
A system is shown in U.S. Pat. No. 5,635,025 in which the chips are fed without prior steaming to a vessel in the form of a combined chip bin, impregnation vessel and chip chute. Steaming of the chips takes place here, the chips lying above the fluid level, and a simple addition of impregnation fluid takes place in the lower part of the vessel.
A further such system is revealed in U.S. Pat. No. 6,280,567, in which the chips are fed without prior steaming to an atmospheric impregnation vessel in which the chips are heated by the addition of warm black liquor that maintains a temperature around 130-140° C. The black liquor at high temperature is added is just below the fluid level and is subjected to a reduction of pressure up through the bed of chips, after which foul-smelling released gases are removed from the top of the vessel. This creates large volumes of foul-smelling gases, which must be handled and destroyed in special systems. In this case, the impregnation fluid passes strictly in a concurrent flow direction, that is, impregnation fluid and chips move in a downwards direction. An alternative system is revealed by SE,A,9802879-8, in which pressurised black liquor is added to the upper part of the steaming vessel, whereby the black liquor after being subjected to a pressure reduction releases steam for the steaming process. In this case, excess fluid, black liquor, can be drawn off from the lower part of the vessel.
The prior art has mostly exploited steaming as a major part of the heating of the chips, in which the steam that is used is either constituted by fresh steam or by steam flashed off from pressurised black liquor obtained from the cooking process. This involves a relatively large flow of steam, and its associated consumption of energy, and it requires a steaming system that can be regulated.
The steaming has also involved the generation of large amounts of foul-smelling gases, and, at certain concentrations, a serious risk of explosion. Problems arise when handling these volatile and readily condensed gases, which, for example, are constituted by turpentine and other hydrocarbons. Special systems for handling these waste gases are required, and these must be dimensioned to cope with the volumes generated. Expensive systems with high capacity are required when these waste gases are created in large volumes.
THE OBJECT AND PURPOSE OF THE INVENTION
The principle object of the invention is to obtain an improved arrangement for the impregnation and heating of unsteamed chips, which arrangement does not demonstrate the disadvantages that are associated with other known solutions as described above.
A second object is to enable that the major part of the heating of the chips is made with impregnation fluid, a process that hereafter will be referred to as “fluid steaming” in which it is possible to obtain a natural reduction in temperature of the impregnation fluid by the establishment of an upper counterflow zone since the cold chips are progressively warmed by direct heat exchange during their downwards sinking motion in the vessel. In this way, it is possible in one preferred embodiment to balance the counterflow in this upper zone such that a suitable temperature is obtained in the upper part of the fluid zone, this temperature preferably being sufficiently low to prevent an extensive flashing of steam upwards through the bed of chips. This reduces the amount of foul-smelling gases released, these being to a large extent bound to the withdrawn impregnation fluid. A direct heat exchange with the cold sinking chips is obtained in the counterflow that is being considered, which is the reason that the impregnation fluid that is withdrawn can be maintained at such a low temperature that the volatile gases that are otherwise expelled can be retained in solution in the colder impregnation fluid, and finally withdrawn to a major degree together with the impregnation fluid.
A further object is to make it possible to control the heating process more accurately by the use of impregnation fluids with increasing temperatures at different positions down through the impregnation vessel, whereby the risk of steam blowing through the bed of chips is eliminated, while it is at the same time possible to obtain a high final temperature of the chips when in slurry form. This fluid steaming, which is thus established over a large section of the impregnation vessel, has surprisingly proved to expel the major part of the air and inert gases that are bound in the chips.
In particular, when cooking eucalyptus and other easily cooked wood raw materials, and in cases when the chips maintain a temperature that is in excess of normal ambient temperature, i.e. over 20° C., the steaming operation using externally applied steam can be completely omitted.
In certain operational situations, such as the use of cold chips during the winter, light steaming may be necessary in order to raise the temperature of the chips to the normal value of 20-30° C., but with a severely reduced requirement for steaming compared with that needed by previously known technology.
A requirement for a certain degree of steaming may arise when using material that requires more cooking, such as softwood, with a high content of turpentine, etc., but this is severely reduced compared with that needed by previously known technology, and thus represents a major reduction in the volume of waste gases generated.
It was also an advantage if a withdrawal strainer was used, with which an efficient separation of not only foul-smelling gases but also impregnation fluid could be achieved. Much of the foul-smelling gases are bound to the withdrawn impregnation fluid when using the wet-steaming technology that is under consideration.
The invention can advantageously be used when cooking eucalyptus, bagasse and other annual plants, and it can also be used in association with the cooking of coniferous and deciduous pulp.
DESCRIPTION OF DRAWINGS
FIG. 1 shows an impregnation vessel according to the invention;
FIG. 2 shows schematically the temperature profile in the impregnation vessel;
FIG. 3 shows a used withdrawal strainer;
FIG. 4 shows the establishment of a counterflow in the upper zone.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
An arrangement for the impregnation of chips during the manufacture of chemical pulp is shown in FIG. 1 . The arrangement comprises an essentially cylindrical impregnation vessel 30 arranged vertically into which unsteamed chips are continuously fed into the top of the impregnation vessel via feed means, in the form of a small chip bin 1 without steaming and a chute feed (chip feed) 2 . The chips that are fed into the impregnation vessel are thus unheated chips that normally have the same temperature as the ambient temperature ±5° C.
The pressure in the vessel can be adjusted as necessary through a control valve 31 arranged in a valve line 4 at the top of the impregnation vessel, possibly also in combination with control of the steam ST via input lines 5 . When atmospheric pressure is to be established, this valve line can open out directly to the atmosphere. It is preferable that a pressure is established at the level of atmospheric pressure, or a slight deficit pressure by the outlet 4 of magnitude −0.5 bar (−50 kPa), or a slight excess pressure of magnitude up to 0.5 bar (50 kPa).
Input of a ventilating flow, SW_AIR (sweep air), can be applied at the top as necessary, which ensures the removal of any gases present.
The impregnated chips are continuously output via output means, here in the form of an outlet 10 , possibly also in combination with bottom scrapers (not shown in the drawing), at the bottom of the impregnation vessel 30 .
According to the invention, a first input line 7 a with impregnation fluid BL 1 is connected to the impregnation vessel at a first height P 1 on the impregnation vessel corresponding to distance H 1 below the strainer 6 , which height is arranged under a maximum level LIQ_LEV of the chips in the impregnation vessel. The temperature of the impregnation fluid BL 1 is adjusted by temperature-regulation means 32 to a first temperature before its addition at this first height, in this case a shunt circuit with cooled and with uncooled impregnation fluid.
Furthermore, at least one other input line 7 b with impregnation fluid is connected to the impregnation vessel at a second height, P 2 , corresponding to distance H 1 +H 2 below the strainer 6 , which second height is arranged under the first height P 1 on the impregnation vessel. The temperature of the impregnation fluid is adjusted by temperature-regulation means 32 to a second temperature before its addition at this second height. This second temperature exceeds the first temperature by at least 5° C.
A withdrawal strainer 6 is arranged in the wall of the impregnation vessel 30 at a height above the first height, whereby a maximum liquid level LIQ_LEV can be established in the impregnation vessel under the highest level CH_LEV of the chips in the impregnation vessel. Control of the level occurs by adjusting the balance between the addition of impregnation fluid BL 1 , BL 2 , (BL 3 ) through the input lines 7 a , 7 b , ( 7 c ) and the current withdrawal REC through the withdrawal strainer 6 and output from the bottom 10 . The liquid level must thus be established such that it lies under the highest level CH_LEV of the chips in the impregnation vessel.
The level CH_LEV of the chips above the level LIQ_LEV of the liquid must be at least 2 meters and preferably at least 5 meters when impregnating eucalyptus. In the case of wood raw material of lower density, for example, softwood, which has a density that is up to 30% lower, a corresponding increase in the height of the column of chips over the surface of the fluid is established. This height is important in order to provide an optimal passage of the chips in a column.
Since the outlet 6 for impregnation fluid is located at a position in the impregnation vessel that lies above the position for addition of the first impregnation fluid BL 1 , a flow in the opposite direction to the sinking motion of the chips is established, indicated by lightly drawn upwards-pointing arrows in FIG. 1 , in at least the upper part of the fluid-filled zone Z 1 in the impregnation vessel 30 .
It is appropriate that the temperature of the first impregnation fluid BL 1 , the first temperature, lies within the interval 105±5° C., and it is appropriate that addition of the first impregnation fluid takes place through a first input line 7 a under a liquid level LIQ_LEV that has been established by added impregnation fluid in the impregnation vessel 30 at a position in the impregnation vessel at which the ambient pressure corresponds to or exceeds the saturation pressure, which corresponds at a temperature of 105° C. to a level at least 2 meters under the established liquid level LIQ_LEV if the impregnation vessel is not subject to an externally applied pressure.
The temperature of the second impregnation fluid BL 2 , the second temperature, lies within the interval 120±10° C. and addition of the second impregnation fluid through the second input line 7 b occurs under the position of addition in the impregnation vessel of the first input line, and at a position in the impregnation vessel at which the ambient pressure corresponds to or exceeds the saturation pressure, which corresponds at a temperature of 125° C. to a level at least 13 meters under the established liquid level LIQ_LEV if the impregnation vessel is not subject to an externally applied pressure.
It is advantageous if at least one third input line 7 c with impregnation fluid is connected to the impregnation vessel at a third height, P 3 , corresponding to distance H 1 +H 2 +H 3 under the strainer 6 , which third height is arranged under the second height P 2 on the impregnation vessel. The temperature of the impregnation fluid is adjusted by temperature-regulation means 32 to a third temperature before its addition at this third height. This third temperature exceeds the second temperature by at least 5° C.
The temperature of the third impregnation fluid BL 3 , the third temperature, lies within the interval 130±15° C. Addition of the third impregnation fluid occurs through the third input line 7 c under the position of addition in the impregnation vessel of the second input line, and at a position in the impregnation vessel at which the ambient pressure corresponds to or exceeds the saturation pressure, which corresponds at a temperature of 130° C. to a level at least 17 meters under the established liquid level LIQ_LEV if the impregnation vessel is not subject to an externally applied pressure.
It is preferable that the added impregnation fluid is obtained from a common flow of withdrawn black liquor BL, preferably a withdrawal of black liquor directly from a subsequent digester or via a pressurised impregnation stage. It is appropriate if this withdrawn black liquor BL is constituted by a non-pressurised withdrawal flow direct from the digester, or from a pressurised impregnation stage.
FIG. 1 shows that the first, second and third impregnation fluids, BL 1 , BL 2 and BL 3 , are to a major degree established from a common flow BL of black liquor that has been withdrawn from a subsequent cooking stage. It is appropriate if this flow is constituted by more than 50%, preferably more than 75%, of black liquor from the digester.
Temperature control of the different temperature levels is obtained by the use of a shunt circuit 32 . This controls the common original flow BL in such a manner that the first impregnation fluid BL 1 is set to the first temperature by cooling means 20 . The cooling means may be an indirect heat exchanger, a pressure drop cyclone or another form of evaporative cooling, or the addition of cold fluid, preferably colder process fluids, basic or washing filtrate.
The third impregnation fluid BL 3 can be obtained directly from the common flow BL of black liquor at the existing temperature of the black liquor. If this temperature is initially too high, cooling of the common flow BL can, naturally, take place first.
The temperature of the second impregnation fluid BL 2 is set by the mixing by means of mixing means, suitably by simple flow regulation in the shunt circuit 32 in a known manner, of the cooled flow BL 1 and the non-cooled sub-flow BL 3 of black liquor.
Even though steaming is not required for readily cooked pulps such as eucalyptus and annual plants, at a normal outdoor around 20° C., addition of extra steam ST can take place through addition means 5 arranged in the wall of the impregnation vessel, or through central pipes, above the fluid level LIQ_LEV established by the impregnation fluid.
Through the arrangement according to the invention using fluid steaming, it is possible to apply a method for the impregnation of chips during the manufacture of chemical pulp in which the chips, without preceding steaming with steam, are continuously fed into the top of an impregnation vessel, in which a pressure, at essentially the same pressure as atmospheric pressure, ±0.5 bar, is established at the top, and from which impregnated chips are continuously fed out from the bottom of the vessel. The chips are subsequently warmed in an upper fluid-filled zone Z 1 of the impregnation vessel by the addition of a first impregnation fluid BL 1 at a first temperature. The chips are subsequently warmed in a second fluid-filled zone Z 2 , under the upper zone, by the addition of at least one second impregnation fluid BL 2 at a second temperature that exceeds the first temperature by at least 5° C. A flow of impregnation fluid in the direction opposite to the sinking motion of the chips is established in at least the upper zone Z 1 of the impregnation vessel by the establishment in the impregnation vessel of a fluid level LIQ_LEV through the addition and withdrawal of impregnation fluid, where the fluid level lies below the maximum level CH_LEV reached by the chips in the impregnation vessel, and by the withdrawal REC of impregnation fluid taking place at a position in the impregnation vessel above the location of addition of the first impregnation fluid.
A better and more accurately controlled heating of the chips can be achieved with this method, during simultaneous impregnation with successively warmer impregnation fluids.
The first temperature of BL 1 is adjusted such that the temperature appropriately exceeds 100° C., preferably within the interval 100-110° C., and addition of the first impregnation fluid takes place under a fluid level in the impregnation vessel that has been established by the added impregnation fluid at a position in the impregnation vessel at which the ambient pressure corresponds to or exceeds the saturation pressure.
The second temperature of BL 2 exceeds 110° C., preferably within the interval 110-130° C., and addition of the second impregnation fluid takes place under the position of addition of the first impregnation fluid in the impregnation vessel, and at a position in the impregnation vessel at which the ambient pressure corresponds to or exceeds the saturation pressure.
In one preferred embodiment, shown in the drawing, the chips are heated in a third fluid-filled zone Z 3 under the second zone by the addition of a third impregnation fluid BL 3 at a third temperature that exceeds the second temperature by at least 5° C. The third temperature is adjusted to exceed 115° C., preferably within the interval 115-145° C., and addition of the third impregnation fluid takes place under the position of addition of the second impregnation fluid in the impregnation vessel, and at a position in the impregnation vessel at which the ambient pressure corresponds to or exceeds the saturation pressure.
An impregnation vessel that is at least 25 meters high, preferably 30-50 meters high, is used in one implementation of the method.
The upper part of the impregnation vessel above the strainer 6 , the height of the chips H 0 together with the empty volume above, can correspond to at least 6 meters (3+3 meters), and a more advantageous approximately 8 meters (5 meters chip height+3 meters empty volume, buffer volume).
Impregnation fluids with progressively increasing temperatures are added according to the invention at increasing distances below the strainer 6 and below the established fluid level LIQ_LEV.
With atmospheric pressure, approximately 100 kPa (1 bar), at the top of the impregnation vessel, the first impregnation fluid having the lowest temperature, a temperature, however, that must exceed 100 degrees, is added at a position at which the hydrostatic pressure from the column of fluid that lies above it corresponds to or exceeds the saturation pressure.
At a temperature of BL 1 of 105° C., this corresponds to a saturation pressure of 120.8 kPa, that is, a fluid column of just over 2 meters height. Thus the line 7 a must open at a location more than 2 meters below the fluid level LIQ_LEV that has been established.
At a temperature of BL 2 of 125° C., this corresponds to a saturation pressure of 232.1 kPa, that is, a fluid column of just over 13 meters height. Thus the line 7 b must open at a location more than 13 meters below the fluid level LIQ_LEV that has been established.
At a temperature of BL 3 of 130° C., this corresponds to a saturation pressure of 270.1 kPa, that is, a fluid column of approximately 17 meters height. Thus the line 7 c must open at a location more than 17 meters below the fluid level LIQ_LEV that has been established.
Naturally, more or fewer additions of impregnation fluids can take place through the impregnation vessel. However, according to the invention, these must always be added such that pressure reduction does not take place, with its associated risk of steam blowing through up through the column of chips, which can disturb the passage of chips and generate foul-smelling gases that are expelled from the chips and are not bound in the withdrawn impregnation fluid REC.
The following table gives suitable positions for the addition of different impregnation fluids at different temperatures, at atmospheric pressure or at a pressures of ±0.5 bar at the top of the impregnation vessel.
Temperature
Height under
Height under
Height under
of
Saturation
fluid level, with
fluid level,
fluid level,
impregnation
pressure
atm pressure
with +50 kPa
with −50 kPa
fluid
kPa
at top
at top
at top
105° C.
120.8
>2 meter
—
>7 meter
110° C.
143.3
>4.3 meter
—
>9.3 meter
115° C.
169.1
>6.9 meter
>1.9 meter
>11.9 meter
120° C.
198.5
>9.8 meter
>4.8 meter
>14.8 meter
125° C.
232.1
>13.2 meter
>8.2 meter
>18.2 meter
130° C.
270.1
>17.0 meter
>12 meter
>23 meter
135° C.
313.0
>23.3 meter
>18.3 meter
>28.3 meter
140° C.
361.3
>26.1 meter
>21.1 meter
>31.1 meter
145° C.
415.4
>31.5 meter
>26.5 meter
The first, second and third impregnation fluids, BL 1 , Bl 2 and BL 3 are in the method according to the invention principally established from one common flow of black liquor that has been withdrawn from a subsequent cooking stage. It is appropriate that the black liquor, which already has a high temperature when withdrawn form the digester, constitutes more than 50% and preferably more than 75% of the impregnation fluid. Energy can be managed in this way in an efficient manner.
The relevant subflows BL 1 , BL 2 and BL 3 with different temperatures are obtained in that the common flow BL is divided into at least two flows: one cooled flow and one non-cooled flow. The temperature of the first impregnation fluid BL 1 is adjusted by cooling the black liquor BL. The third impregnation fluid BL 3 is obtained directly from the common flow of black liquor. The temperature of the second impregnation fluid BL 2 is adjusted by mixing the cooled flow and the non-cooled flow of black liquor.
When impregnation primarily easily cooked types of wood, such as eucalyptus and other annual plants, steaming can be essentially avoided. Steam is thus not added to the chips that lie on top of the fluid level established by the impregnation fluid during normal steady-sate operation. The invention can also be applied even if coniferous and deciduous wood (softwood and hardwood) are used as raw material, giving a markedly reduced need for steaming, that is, a reduced addition of steam.
When treating primarily wood raw material that is difficult to cook, coniferous and deciduous wood, and in operational cases with extremely low temperature of the chips, (such as during the winter), the chips that lie above the fluid level established by the impregnation fluid can be heated by the addition to the impregnation vessel of external steam such that a temperature of the chips of at least 20° C. and of 80° C. at the most is obtained on the chips before the chips reach the fluid level that has been established by the impregnation fluid.
FIG. 2 shows schematically the temperature profile in the impregnation vessel during the use of an arrangement equivalent to that shown in FIG. 1 , when operating conditions are advantageous. The reduced energy supply that is required to raise the temperature by steaming from a low chip temperature to the standard value of 30° C. is shown in the drawing as the diagonally shaded area.
This case is based on chips with a moisture content around 35%, a temperature of approximately 30° C. and a production amount of 1500 ADMT/day. In this case, an input of 0.68 tonne/tonne of wood moisture is obtained, that is, 0.68 tonnes of wood moisture per tonne of chips accompanies the chips.
The arrangement can be adjusted such that the temperature of the impregnation fluid REC that is withdrawn lies around 30° C. The following standard amounts and temperatures apply in these operational conditions:
BL 1 : 105° C., and a flow of 2.85 tonne/hour BL 2 : 125° C., and a flow of 1.5 tonne/hour BL 3 : 132° C., and a flow of 1.5 tonne/hour REC: 30° C., and a flow of 0.96 tonne/tonne (i.e. 0.96 tonne fluid per tonne of chips).
A temperature of the mixture of approximately 117° C. is obtained under these conditions, which, together with the exothermic reaction with the black liquor, which corresponds to a temperature rise of approximately 5° C., ensures a final temperature of approximately 122° C. of the chips when fed out from the impregnation vessel.
At this level of the flow in the counterflow zone Z 1 , which preferably lies within the interval 50-150% of the flow of chips, calculated as a weight percentage, i.e. that 0.50-1.50 tonnes of fluid per tonne of chips is withdrawn at the flow REC, a first heating of the chips is obtained in direct heat exchange between the chips and the counterflow of impregnation fluid, which means that the temperature of the impregnation fluid is gradually reduced up through the zone Z 1 from its value of 105° C. down to 30° C. By adjusting the withdrawal flow, or by adjusting the cooling (in the heat exchanger 20 ), the withdrawal temperature can be maintained essentially constant at such a low value that the impregnation fluid does not cause evaporation of the volatile components of the chips, and/or the black liquor, and instead binds these in the impregnation fluid, with these components being successively withdrawn through the withdrawal flow REC.
FIG. 3 shows an advantageous design of the withdrawal strainer 6 , which can be used in association with the fluid steaming system according to the invention. The withdrawal strainer 6 withdraws impregnation fluid from a fluid steaming arrangement according to FIG. 1 , but is here arranged in the wall of the vessel directly prior to an increase in diameter of the vessel in a conventional manner. The unsteamed chips lie above the fluid level LIQ_LEV in the form of columns of chips with a predetermined height. The fluid level LIQ_LEV is established with the aid of a level sensor 63 that controls the evacuation pump 62 in the lower outlet. The region behind the withdrawal strainer 6 external to the column of chips is divided into an upper and a lower region, whereby a first evacuation channel is connected, via a pump or ejector 61 , to the upper part of the region, and a second evacuation channel is connected, via a pump 62 , to the lower part of the region, for evacuation of volatile gases (and/or foam 65 ) and impregnation fluid in the different evacuation channels. An unlinking plate 64 can be mounted in order to prevent that part of the column of chips that has not yet reached the fluid level from being subjected to too great a deficit of pressure. It is also possible for the pump 62 to drive an ejector 61 such that the fluid that is withdrawn via the pump 62 carries foam and gases with it.
FIG. 4 shows how a counterflow of impregnation fluid can be established by the addition of the first impregnation fluid BL 1 . If a lower temperature of around 100° C. is used for the first impregnation fluid BL 1 , the addition can take place directly under the established fluid level LIQ_LEV, with the subsequent withdrawal radially external to the level of addition P 1 . In this case it is important to establish at least one radial flow BL 1 , with a vertical component of flow BL 1 V and a horizontal component of flow BL 1 H . It is preferable that the ratio of BL 1 V to BL 1 H is maintained above a minimum value 1:10 if the temperature lies around 100° C. and under atmospheric conditions in an impregnation vessel with a diameter of 6 meters. At an increased temperature around 105° C. and under atmospheric conditions in an impregnation vessel of diameter 6 meters, the ratio of BL 1 V :BL 1 H can correspond to 2:3.
The invention can be modified in a number of ways within the framework of the attached claims. Considerably more than 2-3 impregnation fluids of different temperatures can be added at different heights in the impregnation vessel, either through central pipes (that open out in the center of the column of chips) or through inlet nozzles in the wall of the vessel. In the same manner, several locations of addition (different heights) of impregnation fluid at the same temperature can be used, in particular in the lower part of the impregnation vessel.
Withdrawal strainers in addition to that shown in FIG. 1 , strainer 6 , can be used in the lower part of the impregnation vessel. This is particularly true if very high fluid/woods ratios are established in the impregnation vessel, and if the fluid/wood ratio is to be reduced in the outlet or if another fluid is to replace the impregnation fluid in association with the output.
The impregnation fluids BL 1 , BL 2 and BL 3 can also be established from totally separate sources, that is, not from one common flow BL of black liquor. For example, BL 1 may be a wash filtrate, obtained, for example, from the washing zone of the digester, while BL 2 /BL 3 may be impregnation fluid obtained from the cooking circuits of the digester.
The impregnation fluids can also be provided with a basic supplement with the object of establishing alkali profiles that are necessary for the process, in particular if the residual alkali in the black liquor is low. A rapid initial consumption of alkali normally takes place, while it is desired to keep the final withdrawal REC low. This is the reason that progressively increasing supplements of alkali can be added to the impregnation fluids as the chips successively sink downwards through the impregnation vessel.
It is appropriate if the flow REC withdrawn from the impregnation vessel is carried directly to evaporation/recycling.
It is also possible that more than one counterflow zone can be established in the upper fluid-filled part of the impregnation vessel.
An additional supplement of colder impregnation fluid, in the region 60-90° C., may also be added at the top of the fluid-filled counterflow zone. This fluid at a lower temperature can be added continuously or it can be added as required. | The method and an arrangement are for improved impregnation of chips in association with the manufacture of chemical cellulose pulp. Un-steamed chips are fed into an impregnation vessel ( 30 ) in which a fluid level (LIQ_LEV) is established under the highest level (CH_LEV) of the chips. An improved impregnation arrangement for the chips is obtained by the addition of impregnation fluids (BL 1/ BL 2/ BL 3 ) with increasing temperatures at different heights (P 1 , P 2 , P 3 ), and by the establishment of a counter-flow zone (Z 1 ) in the uppermost part of the impregnation vessel. The requirement for steaming may in this way be dramatically reduced while at the same time the amount of expelled waste gases may be minimized. A major part of the volatile compounds present in the wood are bound to the impregnation fluid (REC) that is withdrawn. | 3 |
BACKGROUND
[0001] Generally, information handling devices (or embedded devices) such as mobile phones or tablet computers involve the use of firmware-based images. Conventionally, image files corresponding to an intended geographical region (for sale/distribution), or to another identifying aspect of a device, are installed at manufacture. Put another way, in order to support a preload image, manufacturers currently tend to include one image per country on an information handling device. It can thus become very costly and time consuming to create and maintain a large number of unique images, with considerable complexity being imparted to the process overall.
[0002] In contexts such as those described above, conventional arrangements can also involve the use of multiple partitions, wherein one partition is accorded for each possible customizing option. This, by extension, can occupy an inordinately a large amount of valuable space on a device.
[0003] Generally, it can further be noted that information handling devices have OS images that are monolithic in nature. A process of compiling and building produces an image that contains needed components; however, variations in devices (especially, in their identifying aspects as noted above) normally warrant more patches and updates to be provided that are unique in nature. In other words, to the extent that information handling devices may need to include images or other components that are uniquely tailored to one or more identifying aspects of the device, one or more patches or updates may be needed by way of altering or amending the OS or its functioning in order that such unique variations may adequately be supported. Conventional solutions, accordingly, tend to involve binary patches or partition/image fragmentation in order to permit discrete elements to be updated. This can prove to be an immensely complex and costly task, given the possibly wide range of variability at hand.
BRIEF SUMMARY
[0004] In summary, one aspect provides an information handling device comprising: a base image; one or more processors; one or more memories storing program instructions accessible by the one or more processors; and wherein, responsive to execution of program instructions accessible to the one or more processors, the one or more processors are configured to: communicate an aspect of the information handling device; and assimilate additional image content at the information handling device responsive to communication of the aspect of the device; wherein the base image and additional image content combine to form a unitary device image.
[0005] Another aspect provides a method comprising communicating an aspect of an information handling device; and assimilating additional image content at the information handling device responsive to communication of the aspect of the device; wherein a base image and the additional image content are combined to form a unitary device image.
[0006] An additional aspect provides a program product comprising: a storage medium having program code embodied therewith, the program code comprising: program code configured to communicate an aspect of an information handling device; and program code configured to assimilate additional image content at the information handling device responsive to communication of the aspect of the device; wherein a base image and the additional image content combine to form a unitary device image.
[0007] The foregoing is a summary and thus may contain simplifications, generalizations, and omissions of detail; consequently, those skilled in the art will appreciate that the summary is illustrative only and is not intended to be in any way limiting.
[0008] For a better understanding of the embodiments, together with other and further features and advantages thereof, reference is made to the following description, taken in conjunction with the accompanying drawings. The scope of the invention will be pointed out in the appended claims.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0009] FIG. 1 illustrates an example circuitry of an information handling device system.
[0010] FIG. 2 illustrates another example circuitry of an information handling device system.
[0011] FIG. 3 schematically illustrates an image installing arrangement.
[0012] FIG. 4 schematically illustrates an image installing process.
[0013] FIG. 5 schematically illustrates a device with operating system and application modules.
[0014] FIG. 6 schematically illustrates a device with application package modules.
[0015] FIG. 7 schematically illustrates a process for system image boot to prepare for accommodating at least one update.
[0016] FIG. 8 schematically illustrates an operating system file recovery process.
DETAILED DESCRIPTION
[0017] It will be readily understood that the components of the embodiments, as generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations in addition to the described example embodiments. Thus, the following more detailed description of the example embodiments, as represented in the figures, is not intended to limit the scope of the embodiments, as claimed, but is merely representative of example embodiments.
[0018] Reference throughout this specification to “one embodiment” or “an embodiment” (or the like) means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases “in one embodiment” or “in an embodiment” or the like in various places throughout this specification are not necessarily all referring to the same embodiment.
[0019] Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a thorough understanding of embodiments. One skilled in the relevant art will recognize, however, that the various embodiments can be practiced without one or more of the specific details, or with other methods, components, materials, etc. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obfuscation. The following description is intended only by way of example, and simply illustrates certain example embodiments.
[0020] While various other circuits, circuitry or components may be utilized, FIG. 1 depicts a block diagram of one example of Win-Tel type information handling device circuits, circuitry or components. The example depicted in FIG. 1 may correspond to computing systems such as the THINKPAD series of personal computers sold by Lenovo (US) Inc. of Morrisville, NC, or other devices. As is apparent from the description herein, embodiments may include other features or only some of the features of the example illustrated in FIG. 1 .
[0021] The example of FIG. 1 includes a so-called chipset 110 (a group of integrated circuits, or chips, that work together, chipsets) with an architecture that may vary depending on manufacturer (for example, INTEL, AMD, ARM, et cetera). The architecture of the chipset 110 includes a core and memory control group 120 and an I/O controller hub 150 that exchanges information (for example, data, signals, commands, et cetera) via a direct management interface (DMI) 142 or a link controller 144 . In FIG. 1 , the DMI 142 is a chip-to-chip interface (sometimes referred to as being a link between a “northbridge” and a “southbridge”). The core and memory control group 120 include one or more processors 122 (for example, single or multi-core) and a memory controller hub 126 that exchange information via a front side bus (FSB) 124 ; noting that components of the group 120 may be integrated in a chip that supplants the conventional “northbridge” style architecture.
[0022] In FIG. 1 , the memory controller hub 126 interfaces with memory 140 (for example, to provide support for a type of RAM that may be referred to as “system memory” or “memory”). The memory controller hub 126 further includes a LVDS interface 132 for a display device 192 (for example, a CRT, a flat panel, a projector, et cetera). A block 138 includes some technologies that may be supported via the LVDS interface 132 (for example, serial digital video, HDMI/DVI, display port). The memory controller hub 126 also includes a PCI-express interface (PCI-E) 134 that may support discrete graphics 136 .
[0023] In FIG. 1 , the I/O hub controller 150 includes a SATA interface 151 (for example, for HDDs, SDDs, 180 et cetera), a PCIe interface 152 (for example, for wireless connections 182 ), a USB interface 153 (for example, for devices 184 such as a digitizer, keyboard, mice, cameras, phones, storage, other connected devices, et cetera), a network interface 154 (for example, LAN), a GPIO interface 155 , a LPC interface 170 (for ASICs 171 , a TPM 172 , a super I/O 173 , a firmware hub 174 , BIOS support 175 as well as various types of memory 176 such as ROM 177 , Flash 178 , and NVRAM 179 ), a power management interface 161 , a clock generator interface 162 , an audio interface 163 (for example, for speakers 194 ), a TCO interface 164 , a system management bus interface 165 , and SPI Flash 167 , which can include BIOS 168 and boot code 190 . The I/O hub controller 150 may include gigabit Ethernet support.
[0024] The system, upon power on, may be configured to execute boot code 190 for the BIOS 168 , as stored within the SPI Flash 167 , and thereafter processes data under the control of one or more operating systems and application software (for example, stored in system memory 140 ). An operating system may be stored in any of a variety of locations and accessed, for example, according to instructions of the BIOS 168 . As described herein, a device may include fewer or more features than shown in the system of FIG. 1 .
[0025] Referring to FIG. 2 , with regard to smart phone and/or tablet circuitry 200 , an example includes an ARM based system design, with software and processor(s) combined in a single chip 210 . Internal busses and the like depend on different vendors, but essentially all the peripheral devices ( 220 ) may attach to a single chip 210 . In contrast to the circuitry illustrated in FIG. 2 , the tablet circuitry 200 may combine the processor, memory control, and I/O controller hub all into a single chip 210 , commonly referred to a “system on a chip” (SOC). Also, ARM based systems 200 do not typically use SATA or PCI or LPC. Common interfaces for example include SDIO and I2C. There are power management chip(s) 230 , which manage power as supplied for example via a rechargeable battery 240 , which may be recharged by a connection to a power source (not shown), and in at least one design, a single chip, such as 210 , may be used to supply BIOS like functionality and DRAM memory.
[0026] ARM based systems 200 typically include one or more wireless transceivers, including, but not limited to, WWAN 260 and WLAN 250 transceivers for connecting to various networks, such as telecommunications networks and wireless base stations. Commonly, an ARM based system 200 will include a touchscreen 270 for data input and display. ARM based systems 200 also typically include various memory devices, for example flash memory 280 and SDRAM 290 .
[0027] In addition to the types of devices described and illustrated herein with respect to FIGS. 1 and 2 , embodiments can provide for a hybrid computing system comprising a primary environment (PE) (for example, a conventional computing device platform, such as a Win-Tel platform) and a secondary environment (SE) (for example, a mobile device platform, such as an ANDROID platform) in a single computing system.
[0028] Specific reference will now be made herebelow to FIGS. 3-8 . To facilitate easier reference, in advancing from FIG. 3 to and through FIG. 8 , a reference numeral is advanced by a multiple of 100 in indicating a substantially similar or analogous component or element with respect to at least one component or element found in at least one earlier figure among FIGS. 3-8 .
[0029] It should be clearly understood that the various arrangements and processes broadly described and illustrated with respect to FIGS. 3-8 , and/or one or more individual components or elements of such arrangements and/or one or more process steps associated of such processes, can be employed independently from or together with one or more other components, elements and/or process steps described and illustrated herein. Accordingly, while various arrangements and processes are broadly contemplated, described and illustrated herein, it should be understood that they are provided merely in illustrative and non-restrictive fashion, and furthermore can be regarded as but mere examples of possible working environments in which one or more arrangements or processes may function or operate.
[0030] In accordance with at least one embodiment, there are broadly contemplated herein methods and arrangements for providing, for an information handling device (e.g., a tablet computer or mobile telephone), a limited number of images with common content at a manufacturing stage, whereupon image-unique content can be downloaded and installed at a first boot of the device. Accordingly, a number of images provided at a manufacturing stage can thereby be greatly reduced by breaking up, dividing or delineating device content into common base content and image-unique content. The base content is thereby installed during manufacturing and the first boot content is gathered and installed during a first boot process.
[0031] In accordance with at least one embodiment, by way of an illustrative and non-restrictive example, base content can generally be common across multiple regions and languages while image-unique (first-boot) content can be region- and/or language-specific. (In this vein, region-specific content could be specific to a country or group of countries.)
[0032] In accordance with at least one embodiment, in the context of information handling devices such as mobile phones or tablet computers, a small subset of image content that is common to different geographical regions (or other identifying aspects of a device) are preloaded at manufacture, while region-specific (or aspect-specific) content is downloaded and installed at another time, such as at first boot. This can considerably streamline the process in that easily 70 to 75 percent of image content of a given device can be common with that of other devices (that otherwise may differ in terms of their intended geographical regions or other identifying aspects). For instance, common content can include a base OS as well as language-specific content that may be usable across different regions or countries sharing a common language. On the other hand, region-specific or aspect-specific content can include applications (“apps”) that may be allowed in one country or not another, or may take on a different appearance or functionality in one country as compared to others. Default web browsers, for instance, can emerge as region-specific content.
[0033] FIG. 3 schematically illustrates an image installing arrangement, in accordance with at least one embodiment. As shown, an information handling device 302 includes an image 304 configurable for the device 302 in question. As such, and by way of an illustrative and non-restrictive example, image 304 can include individual apps or other items of content 306 that are common to device 302 and at least one other information handling device (e.g., mobile phones or tablet computers that are to be sold/distributed in a variety of countries or regions). On the other hand, indicated at 308 is a content item that has two components, namely, a component of common content 308 a and a component of unique content 308 b . Finally, indicated at 310 is a content item that represents content unique to device 302 alone or to device 302 and other devices of common aspect (e.g., devices intended for sale/distribution in a common geographical area).
[0034] In accordance with at least one embodiment, device 302 leaves the factory with a pre-loaded image containing content items 306 , and partial item 308 a , already installed. Upon first boot, or at another predetermined or user-selected time, device 302 communicates with a cloud server 312 , which itself includes a catalogue or other database 314 of items of unique content that can be downloaded by devices. Downloading then takes place, whereby a unique content item 310 and partial content item 308 b can be installed. By way of an illustrative and non-restrictive example, cloud server 312 could represent or be associated with an “app store” connected with the manufacturer of device 302 , and the call to initiate downloading unique content items (or partial content items) can be an API (application programming interface) call that is automatically triggered upon first boot or otherwise user-initiated.
[0035] FIG. 4 schematically illustrates an image installing process, in accordance with at least one embodiment. At manufacture, base or common content is obtained by a device ( 416 ). During or upon first boot of the device ( 418 ), either the device will automatically detect a region where the device is located, or the user will specify the region (e.g., from a drop-down menu) ( 420 ). In the former case, the device can determine its location (and thus the region in which it is located) via GPS, network IP or cell tower location/orientation. In either event, the device can then transmit the region along with other device data, the MTM (machine type model; i.e., the type and/or version of the device), user ID, etc., to a preload cloud server ( 422 ). As touched on further above, the cloud server then consults a catalogue of content ( 424 ) that is intended for each MTM/region combination, and the unique content is downloaded and installed at the device ( 426 ). It can be appreciated that, since the unique content is stored at or via a cloud server, the content is easily updatable and does not require a change to a device or manufacturing line when updating of the content needs to take place.
[0036] In accordance with a specific working example, in accordance with at least one embodiment, a cloud server is embodied by an “app store” or “app shop”. Based on data sent to the cloud server, the “app store” decides on additional preload modules that would be intended for a specific MTM/region combination. For example, a tablet computer can be shipped out with a basic OS installed, but during first boot the device will detect, or the user will select, a location where the tablet is first being booted (e.g., a specific country such as Japan). It can also be appreciated that, in the alternative, a user can select a geographic location other than that where the tablet is being booted; e.g., he/she may purchase the tablet and boot it in the U.S. but select another country (e.g., Japan) as a country of destination or residence, for which relevant unique content is to be sought.
[0037] In accordance with at least one embodiment, content does not need to be tied to a specific user of the device in question. However, the user could be asked to register to an “app store” at first boot, whereupon bonus or customer-specific content could be downloaded as further “unique content”.
[0038] In accordance with at least one embodiment, it can be appreciated that there is broadly contemplated herein a combination of device manufacturing with cloud delivery in order to produce a complete image once a customer is in possession of a device. Some discrete components are thereby contemplated in place of a single, monolithic image and associated OS. As such, and as schematically shown in FIG. 5 , a “common” area (or OS core) 528 of an information handling device 502 may contain a kernel, DRM (digital rights management system) and any and all other components that would be common to different devices (e.g., boot code, a partition layout and/or proprietary items such as encryption and enterprise management). Interchangeable first and second core modules 528 a and 528 b , respectively, can represent different versions of a core wherein one includes DRM code and one does not. It is possible to install one core module 528 a / 528 b or the other, and not both, depending on which version of a core is desired for the device 502 in question. However, it is also conceivable to have both 528 a / 528 b installed, wherein the one needed or desired for device 502 can then be activated.
[0039] On the other hand, in accordance with at least one embodiment, additional modules can be constituted by a preload install area (PIA) 530 and a cloud-based delivery area 532 . Each of the three areas 528 / 530 / 532 can contribute components to produce what the customer might expect to get with a device when he/she purchase it, based on an intended geographical region and/or other identifying aspect of the device.
[0040] In accordance with at least one embodiment, the common area (or OS core) 528 covers many images that would be common to different information handling devices. Components of PIA area 530 , on the other hand, can be unique to a customer, or for a region. Further, cloud content, delivered to the cloud delivery area 532 , can be delivered at first boot, is not tied to the manufacturing process, and provides flexibility by allowing the cloud content to be defined in the servers, such that the user can get predefined packages at first boot. Such packages may be based on an intended geographical region and/or another identifying aspect of the device.
[0041] In accordance with at least one embodiment, it can be appreciated that a modular device is accorded, that flexibly can be tailored or customized to devices associated with an intended geographical region and/or one or more other identifying aspects of devices. At the point of manufacture, the PIA area 530 and OS core 502 are present. However, the PIA area 530 is configured to accommodate additional patches for configuring the device for an intended geographical region and/or one or more other identifying aspect. Such patches can already be present in the device 502 at manufacture (e.g., in a repository within the device, which may, e.g., be within or constituted by the PIA area 530 ), to then be activated at a predetermined time (e.g., at first boot), or could be downloadable (e.g., from a cloud server) at a predetermined time (e.g., at first boot). (Device 502 can even accommodate both scenarios if desired, i.e., activate one or more patches already present in the device and download one or more from elsewhere [e.g., a cloud server], each at the same or different predetermined times.) Though OS patches can take on a very wide variety of forms, by way of illustrative and non-restrictive example they can include a patch to tether a given app to the device and/or to disable such an app (in the OS core).
[0042] In accordance with at least one embodiment, to the extent that OS patches are discussed herein, it can be appreciated that downloadable items such as those found in an “app store” present a different task in that such items are end user items and can be installed, removed, modified. In other words, OS patches and related items are beyond the sight or control of an end user, while downloadable items such as apps are not, and embodiments herein variously address both types of components to the extent that an information handling device can be customized or tailored for a particular intended geographical region and/or other identifying aspect of the device.
[0043] FIG. 6 schematically illustrates an embodiment in which apps and predefined packages are involved. As shown, a core OS 628 and core common apps 634 can be loaded at manufacture. On the other hand, a number (five are shown here) of country- or region-specific packages 636 can be downloaded from an app shop or cloud server. The packages 636 can each include, among other things, “mandatory” apps 638 that would be shared by at least some devices, and others 640 that would be unique to some devices (e.g., based on intended geographical region) and not shared by some others. (In accordance with the present illustrative example, “mandatory” apps 638 can be common to some devices, e.g., within a very broadly defined geographic region, or could even be common to all devices. These can be distinguished from core common apps 634 based on given criteria, or in some cases need not necessarily be distinguishable from core common apps 634 but for the manner in which they are provided to device 602 . By way of a non-restrictive example, mandatory apps 638 can be considered at a given point in time to be required for a large number of devices, with a recognition that their necessity may not be of a permanent nature and that they could easily be replaced or reconfigured with other apps at some point in the future. While this can also hold true for core common apps 634 , it is conceivable to include apps among core common apps 634 that are considred to be more permanent in nature, or less likely to be replaced or reconfigured at a future timepoint. In this manner, a hierarchy of common apps can be afforded, wherein those thought to be more permanent can be included in core common apps 634 while those thought to be less permanent and more changeable can be included in mandatory apps 638 .)
[0044] In accordance with at least one embodiment of the invention, to the extent that geographical regions are discussed herein as representing a parameter for identifying a device and determining content to be supplied to the device, one or more other identifying aspects of a device, instead or in addition, could be employed to assist in making such a determination. Thus, for instance, instead of identifying a geographical region of or for a device, the device could be identified by a device identifier not associated with a geographical region. For example, such a device identifier could be an MTM (machine type model, or model number), wherein devices presenting a given model number would trigger the downloading or supplying of additional (and/or unique) image or operating system content to a device. Other device identifiers can include, by way of example, a serial number, a user or a company associated with the device.
[0045] In accordance with at least one embodiment, to the extent that OS patches may have been included in or downloaded to a device, thus altering the basic makeup and functioning of the OS itself, broadly contemplated herein are arrangements for recovering any missing or altered components of an original OS at least to such a degree as to adequately accommodate updates to the OS or other area of the device. As can be appreciated from the foregoing, a system image can be split generally into two portions, wherein one portion is common to a majority or large number of information handling devices in a given distribution, with the other portion representing an overlay of distribution-specific files. At first boot, a program can be run just after the file systems are mounted to create a series of links to region-specific files in another partition (e.g., a PIA area such as that indicated at 504 in FIG. 5 ). This program can check for the existence of a recovery list to quickly exit so as to not slow the device down during subsequent boots, wherein such a recovery list would contain files or portions thereof that would need to be recovered at a subsequent time in connection with accommodating an OS update or OTA patch (see below). The program can also process a list of files to delete from the system image and then creates links from a parallel system image and the common system image. Files are not then removed but are renamed to a backup name, to prevent actual installation or usage of these files.
[0046] In accordance with at least one embodiment, all files that are modified are indeed written to a list of files, or recovery list that would need to be corrected when an update such as an OTA (over-the-air) patch is applied. (An “OTA patch” can be recognized herein as a specific type of update that can be accommodated by a device; it is provided here as but an illustrative and non-restrictive example of an update.) On boot of the device into recovery mode to apply an OTA patch or other update, the recovery list is read in and the links are removed. Also, any backup files are restored so that when the OTA patch (or other update) is applied the system partition appears similarly to the base partition. Thence, again at reboot, the process of recreating the links occurs to re-customize the device for distribution. It can thus be appreciated that, throughout the process, certain files and actions relating thereto are hidden to the end-user, and only are exploited to the extent that would be needed to accommodate an OTA patch (or other update).
[0047] Accordingly, FIG. 7 schematically illustrates a process for system image boot to prepare for accommodating at least one update, such as an update (e.g., OTA patch) to an OS, in accordance with at least one embodiment. First, a check is made for a recovery list ( 738 ). If the list does exist, then the process exits. Otherwise, a check ( 740 ) is made for a PIA in the device (e.g., as indicated at 530 in FIG. 5 ) and, if one is not found, the process exits, while the process continues if indeed a PIA is present.
[0048] As such, in accordance with at least one embodiment, the system remounts (i.e., there is a disconnect from the file system, followed by reconnect to the file system) and system read-write is permitted temporarily ( 742 ). If a log file cannot be written into, then the process finishes with an error ( 744 ). Otherwise, a check is made as to whether a delete file list is present ( 746 ), for example (but not necessarily), in the PIA. (The delete file list, for its part, may be sight-unseen to the user in embodiments, or alternatively could be visible to the user.) If such a file exists, then it is opened for read ( 748 ) and, for each file listed, if the named file exists, then that file is renamed (e.g., to “name_orig”) and the file is then dispensed with (e.g., archived, backed up, or deleted, and/or [for instance] written to the recovery list file) ( 750 ). The delete file list is then closed ( 752 ). In accordance with at least one embodiment, “/system” is pushed onto the work stack ( 754 ) and, for as long as the work stack is not empty, a “top entry” is opened and the status of a PIA file is checked ( 756 ) to see if it is a directory or file ( 758 ). (It should be noted that “/system” can be a location where the OS and device-specific apps. [e.g., that were added during manufacturing] can be stored, and which location is typically read-only to the end user. On the other hand, “/data” can be a location where end-user content is stored and typically could be writable to by the end-user.) If a directory, then a check is made to see if “/system/name” exists ( 760 ); if not, a directory is created and the name is written to the recovery list file ( 762 ). If not a directory, then if ( 764 ) there exists a file “/system/file”, this file is renamed to “/system/file orig” ( 766 ). A symbolic link is then created between “pia/system/file” and “/system/file”, and the name (the file in the PIA that was linked to, or the file that was renamed in step 766 ) is written to the recovery list ( 768 ). (It should be noted that the written name, as just mentioned, need only represent some sort of unique identifier that will permit the recovery list to find the change). If the work stack is not empty, then ( 770 ) a reversion is made to step 756 ; otherwise, the recovery list file is then closed, and then the system remounts and reverts to read-only ( 772 ).
[0049] In accordance with at least one embodiment of the invention, and as schematically illustrated in FIG. 8 , during recovery the following process is undertaken. The existence of a recovery list file is checked for ( 839 ). If it does not exist, then the process exits. Otherwise, the system remounts and an attempt at read-write is made ( 841 ), but if ( 843 ) the attempt is not successful then a log file is created in cache ( 845 ) and the process exits with an error. As the process continues, the recovery list file is opened ( 847 ) and each line in the file is pushed onto a work stack ( 849 ). The recovery list is then closed ( 851 ).
[0050] In accordance with at least one embodiment of the invention, for as long as the work stack is not empty, the top of the stack and stat file are removed. If ( 855 ) the removed file is a directory, the directory is removed ( 857 ); else, the file is unlinked ( 859 ). Continuing, if the file is not a directory, then (by way of an illustrative and non-restrictive example) a check is made as to whether ( 861 ) a file with the name, “name orig” exists; if so, then it is renamed to “name” ( 863 ). In all eventualities here, if the work stack is not empty, a reversion ( 865 ) is made back to step 853 ; otherwise, the recovery list is removed, the system remounts, and read-only is reverted to ( 867 ).
[0051] In accordance with at least one embodiment of the invention, to the extent that information handling devices are discussed herein, it should be understood that they can represent a very wide range of devices, applicable to a very wide range of settings. Thus, by way of illustrative and non-restrictive examples, such devices and/or settings can include mobile telphones, tablet computers, other portable computers such as portable laptop computers, and appliances, such as televisions, which may contain or incorporate an information handling device and/or aspects thereof
[0052] As will be appreciated by one skilled in the art, various aspects may be embodied as a system, method or computer (device) program product. Accordingly, aspects may take the form of an entirely hardware embodiment or an embodiment including software that may all generally be referred to herein as a “circuit,” “module” or “system.” Furthermore, aspects may take the form of a computer (device) program product embodied in one or more computer (device) readable medium(s) having computer (device) readable program code embodied thereon.
[0053] Any combination of one or more non-signal computer (device) readable medium(s) may be utilized. The non-signal medium may be a storage medium. A storage medium may be, for example, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of a storage medium would include the following: a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.
[0054] Program code embodied on a storage medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, et cetera, or any suitable combination of the foregoing.
[0055] Program code for carrying out operations may be written in any combination of one or more programming languages. The program code may execute entirely on a single device, partly on a single device, as a stand-alone software package, partly on single device and partly on another device, or entirely on the other device. In some cases, the devices may be connected through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made through other devices (for example, through the Internet using an Internet Service Provider) or through a hard wire connection, such as over a USB connection.
[0056] Aspects are described herein with reference to the figures, which illustrate example methods, devices and program products according to various example embodiments. It will be understood that the actions and functionality illustrated may be implemented at least in part by program instructions. These program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing device or information handling device to produce a machine, such that the instructions, which execute via a processor of the device implement the functions/acts specified.
[0057] The program instructions may also be stored in a device readable medium that can direct a device to function in a particular manner, such that the instructions stored in the device readable medium produce an article of manufacture including instructions which implement the function/act specified.
[0058] The program instructions may also be loaded onto a device to cause a series of operational steps to be performed on the device to produce a device implemented process such that the instructions which execute on the device provide processes for implementing the functions/acts specified.
[0059] This disclosure has been presented for purposes of illustration and description but is not intended to be exhaustive or limiting. Many modifications and variations will be apparent to those of ordinary skill in the art. The example embodiments were chosen and described in order to explain principles and practical application, and to enable others of ordinary skill in the art to understand the disclosure for various embodiments with various modifications as are suited to the particular use contemplated.
[0060] Thus, although illustrative example embodiments have been described herein with reference to the accompanying figures, it is to be understood that this description is not limiting and that various other changes and modifications may be affected therein by one skilled in the art without departing from the scope or spirit of the disclosure. | Systems, methods and products directed toward creating device preloads via employing base and additional image content. One aspect includes communicating an aspect of an information handling device, and assimilating additional image content at the information handling device responsive to communication of the aspect of the device, wherein a base image and the additional image content are combined to form a unitary device image. Other embodiments are described herein. | 6 |
BACKGROUND OF THE INVENTION
The invention relates to a speed control device that can be used to vary the speed at which a motor operates. This invention is particularly useful for increasing or decreasing the speed of an air compressor for keeping the air compressor operating at or near its maximum capacity. In one of the more specific aspects of the present invention, the air compressor contains a variable drive means for increasing or decreasing the speed on the air compressor.
The application for the speed control device of the present invention can be appreciated by reviewing the prior art in the air compressor area. Air compressors are one application where the present invention can most advantageously be utilized. Most traditional air compressors contain a motor that is used to drive a compressor. The compressed air produced by the compressor is directed to an air reservoir where the compressed air is maintained until it is used. In most applications a constant speed electrical motor is used to drive the compressor. A belt or other suitable drive means is used to connect the motor and compressor. The constant speed motor will normally have a maximum amperage rating at which it can be safely operated.
When the compressor first begins to supply air to the air reservoir there is little or no pressure in the reservoir and the compressor can easily supply the compressed air to the reservoir. At this initial state there is very little loading on the motor that drives the compressor. As the pressure in the reservoir increases the motor and the compressor will have to work harder to supply additional air to the reservoir. This results because the air being supplied from the compressor will have to be at a higher pressure than the air in the reservoir for additional air to enter the reservoir. As the air pressure in the reservoir increases the motor and compressor will be forced to work harder to supply the higher pressure air to the reservoir. In most applications the motor is sized so that it is working at or near its maximum amperage rating when the compressor is supplying air to the reservoir at the maximum designed pressure for the compressor.
Over much of the operating range for the air compressor the constant speed electrical motor is working below its maximum designed rating. The motor is being under utilized except during the limited time that the compressor is supplying air at the maximum rated air pressure for the compressor. The under utilization of the motor on the air compressor reduces the efficiency and performance of the compressor.
Therefore, it would be desirable to have a speed control device for use with an air compressor where the motor that drives the compressor operates at or near its maximum rated amperage level throughout the operational cycle of the air compressor. By having the motor operating at its maximum rated capacity the compressor would be capable of producing greater volumes of lower pressure air and the compressor would reach its maximum rated air pressure more quickly.
SUMMARY OF THE INVENTION
According to the invention, there is provided motor control apparatus comprising a motor and means for loading the motor. The load means is spaced apart from the motor and operatively connected to the motor. A variable drive means is operatively connected between the motor and the load means. The variable drive means includes means for changing the loading on the motor. A sensing means is provided for actuating the variable drive means whereby the speed and the loading on the motor can be varied.
There is also provided an air compressor apparatus comprising motor means and a compressor spaced from the motor means. An air receiving container is provided for receiving air from the compressor. A variable drive means is operatively connected between the motor means and the compressor. The variable drive means includes means for increasing or decreasing the loading on the motor. A sensing means is providcd for actuating the variable drive means.
According to the invention there is further provided a method for controlling the speed of a motor. The motor drives a load means. A variable drive means is operatively connected between the motor and the load means. The operating conditions of the motor are sensed during the operation of the motor. The variable drive means is activated in response to the operating condition of the motor to vary the speed and the loading on the motor.
There is also provided according to the invention a method for varying the load on the motor of an air compressor The motor drives a compressor to supply air under pressure to an air receiving container. The motor is movably mounted with respect to the compressor and a variable drive means is operatively connected between the motor and the compressor. The air pressure in the air receiving container is sensed by a monitoring means. The motor is moved with respect to the compressor in response to the air pressure in the air receiving container. As the motor moves the variable drive means changes the drive ratio between the motor and the compressor whereby the loading on the motor is varied.
It is an object of the invention to provide an improved means for controlling a motor.
It is an object of the invention to provide an improved air compressor apparatus.
It is also an object of the invention to provide an improved method of operating an air compressor.
It is a further object of the invention to provide an improved air compressor apparatus and method for operating the air compressor to maximize the output of the air compressor.
Other objects and advantages of the invention will become apparent as the invention is described hereinafter in detail and with reference to the acoompanying drawings.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an improved air compressor in accordance with the present invention.
FIG. 2 is a partial front elevation view with a cross sectional view of a portion of the air compressor.
FIG. 3 is a cross sectional view of one feature of the air compressor.
FIG. 4 is a perspective view of another embodiment of an air compressor of this invention.
FIG. 5 is a side elevation view of another embodiment of an air compressor of this invention.
FIG. 6 is a graph comparing the performance of an air compressor utilizing the present invention and traditional air compressors.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
This invention relates to a motor control containing a variable drive means for increasing or decreasing the speed and the loading on the motor. The invention is particularly useful on air compressors. To facilitate the description of the invention; the invention will be described as used in connection with an air compressor. However, it should be understood that the invention can be used in other areas, such as, fan, pump and conveyor drives. Features of this invention will be more fully understood by referring to the attached drawings in connection with the following description.
FIG. 1 shows one embodiment of the air compressor of this invention. The air compressor 1 contains an air reservoir 3 in which compressed air is stored. Mounted on the air reservoir 3 is a compressor 5 and there is a pulley 7 positioned on the shaft 9 of the compressor. A constant speed electrical motor 15 is also positioned on the air reservoir 3. A variable drive means in the form of a variable pitch pulley 18 is positioned on the output shaft of the motor. The variable pitch pulley 18 is shown in more detail in FIG. 3. The motor 15 is mounted on a pivotable base 19. A continuous drive belt 21 passes around the pulley 7 and the variable pitch pulley 18 to operatively connect the motor 15 and the air compressor 5. An idler pulley 23 can be positioned at a point along the path of the drive belt 21 to insure that the drive belt is properly tensioned.
FIG. 2 shows additional detail of the pivotal base 19 that is used to support the motor 15. The base 26 of the motor 15 is mounted on member 27. The member 27 is pivotally connected to support 29 by means of a pin 31 or other suitable securement means. The member 27 is mounted on the support 29 so that the member is free to pivot about the longitudinal axis of the pin 31.
An air cylinder 35 is positioned in the air reservior. The air cylinder contains a piston 37 having a shaft 39 connected to the piston. One end of the shaft 39 projects through an aperture in the air reservoir and contacts the member 27. The end 43 of the air cylinder is open to the air reservoir. A spring 51 is positioned in the air cylinder between the piston 37 and a snap ring 45. The spring acts to bias the piston 37 and shaft 39 towards the member 27. Suitable seals can be provided on the piston 37 and around the shaft 39 to prevent or reduce the leakage of air from the air cylinder 35.
FIG. 3 shows additional details of the variable pitch pulley 18 which can be used as the variable drive means associated with this invention. The variable pitch pulley 18 is mounted upon the drive shaft for the motor 15. The variable pitch pulley 18 contains a center shaft 59 that is securable to the drive shaft of the motor. The first side wall 61 of the pulley is securely attached to the shaft 59. The second side wall 65 of the pulley is slideably mounted upon the shaft 59. A cap 67 is positioned on the end of the shaft 59 that is spaced apart from the motor 15. A spring 69 extends between the second side wall 65 of the pulley and the cap 67. The spring 69 acts to bias the second side wall 65 towards the first side wall 61. Although a variable pitch pulley 18 has been shown as the variable drive means that is associated with the motor 15, it should be understood that other variable drive means can be used in the present invention.
The operation of the present invention will best be understood by referring to FIGS. 1,2 and 3 in connection with the following description. The constant speed motor 15 is energized which causes the drive shaft of the motor to rotate at a constant speed. The rotation of the drive shaft of the motor 15 will cause the variable pitch pulley 18 to rotate and the drive belt 21 to advance. As the drive belt 21 operatively connects the variable pitch pulley 18 with the pulley 7 on the compressor 5, the compressor 5 will be engaged or caused to rotate by the advancement of the belt 21. Rotation of the compressor 5 will cause air under pressure to be directed into the air reservoir 3. An idler pulley 23 can be positioned along the path of the drive belt 21 to insure that there is proper tension on the drive belt 21.
The motor 15 is designed to operate at a constant speed over the operating range for the air compressor. The motor also has a maximum amperage rating at which the motor can be operated. The motor 15 produces its greatest output at this maximum amperage rating. Accordingly, it is desirable to have the motor operate at this maximum amperage level over the entire operational spectrum of the air compressor to continuously derive the maximum output from the motor 15.
To keep the motor 15 operating at its maximum capacity a variable pitch pulley 18 and a pivotal base 19 have been connected to the motor 15. Details of a variable pitch pulley 18, which is suitable for use with this invention, are shown in FIG. 3. The pivotal base 19 is used in connection with the variable pitch pulley to alter the position of the motor 15 with respect to the compressor 5 and to alter the drive ratio between the motor and the compressor. By altering the drive ratio between the motor and the compressor the speed at which the compressor rotates can be varied.
The air cylinder 35 is used to control the position of the motor 15. When the motor 15 is initially started and there is little or no built up pressure in the air reservoir 3 the motor 15 will be biased towards the compressor 5 by the tension on the drive belt 21. The tension on the drive belt 21 will be created by the variable pitch pulley 18. The spring 69 on the pulley 18 biases the second side wall 65 of the pulley towards the first side wall 61 of the pulley. The biasing of the second side wall 65 reduces the v-shaped opening formed between the two side walls of the pulley and forces the drive belt further from the center of the variable pitch pulley. The tension on the drive belt 21 causes the member 27 to pivot on the support 29 so that the motor 15 is positioned closer to the compressor 5.
When the drive belt 21 is displaced from the center of the variable pitch pulley 18 by the spring 69 the drive ratio between the pulley on the motor 15 and the pulley on the compressor 5 will change. As the drive belt 21 moves further from the center of the pulley 18 the drive belt 21 will be advanced further by each rotation of the pulley 18 and the speed at which the belt is traveling will increase. As shown in the upper half of FIG. 3 the drive belt 21 is displaced the maximum distance from the center of the variable pitch pulley 18. In this position each rotation of the motor 15 and the pulley 18 will cause the drive belt 21 to be advanced the maximum distance. Thus, the drive belt will be advancing at its maximum speed. Accordingly, when the drive belt is in the position shown in the upper portion of FIG. 3 the drive belt 21 will cause the compressor to operate at the fastest speed.
As the air pressure in the air reservoir 3 increases the load on the compressor increases and the compressor 5 will have to work harder to supply additional compressed air to the reservoir. As the load on the compressor 5 increases the speed at which the compressor is operating must be reduced to avoid overloading the motor 15.
The pivotal base 13, air cylinder 35 and variable pitch pulley 18 are utilized to vary the operating speed of the compressor 5 and the motor 15. The end 43 of the air cylinder 35 is open to the air reservoir 3. The pressure of the air in the reservoir acts directly on the piston 37 of the air cylinder. As the pressure of the air in the reservoir 3 increases the force on the piston 37 will increase. The force of the air pressure on the piston acts to cause the piston and shaft to move towards the motor 15. The spring 51 in the air cylinder 35 is also positioned to supply a force that biases the piston 37 and shaft 39 towards the motor. As the shaft 39 moves toward the motor 15 it acts against the member 27 and causes the member 27 to pivot on support, 29. The pivoting of the member 27 caused by the shaft 39 moves the motor 15 away from the compressor 5. As the motor 15 moves away from the compressor 5 the tension on the drive belt 21 will be increased. As the tension on the drive belt 21 increases the force on the second side wall 65 of the pulley will become greater than the biasing force of the spring 69. Thus, the second side wall 65 will slide along the shaft 59 of the variable pitch pulley 18 towards the cap 67. The second side wall 65 will continue to slide on the shaft 59 until the motor 15 stops moving away from the compressor 5. The motor will stop moving away from the compressor when the biasing force of the spring 69 equals the force on the piston 37 from the air pressure in the reservoir 3 and the biasing force on the piston from the spring 51.
The movement of the second side wall 65 will expand the v-shaped section that is formed between the first and second side walls of the pulley. The tension on the belt 21 will cause the belt to move towards the center of the pulley 18 into the expanded v-shaped section formed between the first and second side walls. As the drive belt 21 moves closer to the center of the variable pitch pulley 18 the drive ratio between the variable pitch pulley 18 and the pulley 7 on the compressor 5 will change. Each rotation of the variable pitch pulley 18 will not advance the drive belt as far as the drive belt moves towards the center of the pulley 18. Thus, as the belt 21 moves towards the center of the pulley 18 the belt will advanced at a slower speed and the compressor 5 will be caused to rotate at a slower speed. The lower portion of FIG. 3 shows the second side wall 65 displaced towards the end cap 67 to such an extent that the drive belt 21 is adjacent the center section of the pulley. In this position the drive belt 21 will cause the compressor to operate at the slowest speed.
As the pressure in the air reservoir 3 increases the piston 37 and shaft 39 will continue to move toward the motor 15.
The air cylinder 35, pivotal base 19 and variable pitch pulley 18 are constructed so that they cooperate to insure that the compressor 5 is receiving as close as possible the maximum driving force from the motor 15 during the operation of the air compressor. When the air reservoir 3 is at a low pressure the compressor 5 can be operated at a higher speed so that larger quantities of low pressure air are delivered to the reservoir. As the pressure in the reservoir increases the speed of the compressor 5 will be reduced and smaller quantities of higher pressure air are delivered to the reservoir 3. The speed of the compressor 15 is directly proportional to the air pressure in the air reservoir. As the air pressure increases the compressor will have to operate at a lower speed to avoid over loading the motor. If the pressure in the reservoir decreases the compressor can be operated at a faster speed to compensate for the lower pressure. Although the speed of the compressor 5 will vary the motor 15 will always operate at a constant speed and the load on the motor will always be at or near the maximum load rating for the motor.
The biasing force of the spring 69, biasing force of spring 51 and the cross sectional area of the piston 37 can be selected to require that a preselected air pressure be established in the reservoir 3 before the piston and shaft begin to move towards the motor. Thus, a preselected pressure will have to be reached before the speed of the compressor is reduced. This mode of operation will insure that the compressor will supply the largest quantity of low pressure air to the reservoir. However, the preselected air pressure cannot be set at a point that will cause the motor to become overloaded before the motor moves away from the compressor and reduces the speed at which the compressor is rotating.
FIG. 4 shows another embodiment of the air compressor invention. In this embodiment an idler pulley 73 is positioned so that the drive belt 21 engages the idler pulley. The idler pulley is mounted on a bracket 72 and the idler pulley 73 and bracket 75 are slideably mounted on a frame 77. An air cylinder 79 containing a shaft 81 and a piston (not shown), similar to the piston and shaft shown for the, previously described air clyinder 35, is mounted on the frame 77. The shaft 81 of the air clyinder 72 engages the bracket 75 which is slideably mounted in the frame 77. A conduit 83 connects the air reservoir 3 with the air clyinder 79.
In operation the embodiment shown in FIG. 4 will operate essentially as the previously described pivotal base 19 and air cylinder 35 to vary the position of the drive belt 21 in the variable pitch pulley 18 on the motor 15. The pressure in the air reservoir 3 is supplied to the air cylinder 79 through conduit 83. An increase in the air pressure in the reservoir will cause the piston in the air cylinder 79 to move towards the bracket 75. The movement of the piston will cause the shaft 81 to also move towards the bracket 75. The motion of the shaft 81 will cause the bracket 75 and the idler pulley 73 to move in a direction towards the drive belt 21. Thus, as the air pressure in the air reservoir 3 increases the shaft 81 will cause the bracket 75 and idler pulley 73 to move in a direction that will increase the tension on the drive belt 21. The increased tension on the drive belt 21 will cause the second side wall 65 of the variable pitch pulley 18 to slide on the shaft 59 of the variable pitch pulley. As the second side wall 65 moves along the shaft 59 the drive belt 21 will move into the increased width of the slot, formed between the first side wall 61 and the second side wall 65, towards the center region of the pulley 18. As previously explained, when the drive belt moves to a different position in the variable pitch pulley 18 the speed of the belt will vary. As the speed of the belt 21 varies the speed at which the compressor 5 is rotating will also vary. Thus, the speed of the compressor will be caused to vary with the air pressure in the air reservoir 3.
The idler pulley 73, air cylinder 79, and variable pitch pulley 18 of this embodiment are constructed so that the compressor 5 will be operating at a speed, throughout the operational range of the air compressor, that keeps the motor 15 operating at or near the maximum capacity for the motor.
FIG. 5 shows another embodiment of the present invention. In this embodiment a drive motor 87 is supported on a pivotal base 86. A variable pitch pully 18 is mounted on the output shaft of the motor 87. A drive belt 21 operatively engages the variable pitch pulley 18. The drive belt 21 operatively connects the motor 87 to a suitable compressor or load means (not shown). Power is supplied to the constant speed motor 87 by a power line having a first conductor 89 and a second conductor 90. A resistor 91 is positioned in the second conductor 90 adjacent to the motor 87. A first electrical connector 92 is connected to the second conductor 90 between the resistor 91 and the motor 97. A second electrical connector 93 connects to the second conductor 90 on the other side of the resistor 91. The first and second electrical connectors are connected to a rectifier 94. The rectifier 94 is electrically connected to a solid state control chip 95. An example of a suitable control chip is an AIRPAX SAA 1-27 Driver. The resistor 91, rectifier 94 and control chip 95 provide a means for sensing the operating condition of the motor. The control chip 95 is electrically connected to a stepper motor driven linear actuator 97. The linear actuator has a threaded member 96 that is connected to the pivotal base 86 for the motor 87. An example of a suitable stepper motor driven linear actuator is an AIRPAX Series 92400 linear actuator.
In operation the first conductor 89 and second conductor 90 supply power to the motor 87 for operating the motor and driving the compressor (not shown). There is a voltage drop across the resistor 91 which is proportional to the current which is passing through the resisitor. The voltage drop across the resistor 91 will be transmitted to the rectifier 94 through first electrical connector 92 and second electrical connector 93. The rectifier 94 converts the voltage drop across the resistor 91 to a D.C. signal. The D.C. signal will be transmitted from the rectifier to the control chip 95. The control chip analyzes the signal to determine the load on the motor 87. If the load on the motor is not at the level to provide optimum performance of the air compressor, the control chip will send a signal to activate the linear actuator. The signal from the control chip will cause the stepper motor to rotate which in turn will rotate the threaded shaft 96 of the linear actuator. Rotation of the threaded shaft will cause the shaft to be displaced in a direction that is parallel to the longitudinal axis of the shaft. The shaft will move in a direction that is generally either toward or away from the motor 87 depending on the direction of rotation of the shaft. Since the shaft 96 is connected to the pivotal member 86 the member and the motor 87 will move in response to movement of the threaded shaft 96. Thus, the control chip 95 can activate the linear actuator to change the position of the motor 87 with respect to the compressor to vary the loading on the motor.
By changing the position of the motor 87 with respect to the compressor, the drive belt and variable pitch pulley will cooperate to vary the drive ratio between the motor and the compressor. As the drive ratio changes the loading on the motor 87 will also change. The variable pitch pulley 18 and drive belt 21 cooperate to vary the loading on the compressor in response to the movement of the motor in the manner that has previously been described.
The control chip 95 is normally constructed so that when maximum rated loading for the motor 87 is reached the control chip will send a signal to the linear actuator 97 to advance the threaded shaft 96 so that the motor 87 will pivot away from the compressor. As the motor pivots away from the compressor, the loading on the motor will be reduced and the maximum rated loading for the motor will not be exceeded. There will also be a low point on the loading range for the motor 87 and when this low point is reached the control chip will send a signal to the linear actuator 97 to rotate the threaded shaft 96 so that the motor 87 moves towards the compressor. As the motor moves towards the compressor the loading on the motor will increase and the motor will be kept operating in a range where substantially the maximum amount of work is received from the motor. In between the high and low load values established in the control chip 95 for the motor, the control chip 95 will not send a signal to the linear actuator and the position of the motor with respect the compressor will not be changed. Accordingly, the load on the motor will also not be changed. Normally the acceptable load range in which the motor will be allowed to operate will be very small. For example, if the maximum rated load for the motor is set at 20 amps. the control chip 95 would send a signal to the linear actuator 97 to reduce the loading on the motor when this maximum loading is obtained. The minimum loading point established in the control chip for this example could be set at 19 amps. When the load on the motor fell to 19 amps. the control chip 95 would send a signal to the linear actuator 97 to increase the loading on the motor. When the motor was operating at a load level between 19 and 20 amps., the control chip 95 would not send a signal to the linear actuator 97 and the load on the motor would not be changed. Thus, in this example, the control mechanism in this embodiment would operate to cause the motor 87 to operate in a very narrow load range. This narrow load range is also very close to the maximum rated loading for the motor. Accordingly, the motor would be caused to operate at a level close to the maximum rated load for the motor and substantially the maximum output of the motor would be utilized over the entire operational range for the air compressor.
FIG. 6 is a graph which demonstrates the improved performance that can be expected by utilizing the present invention on an air compressor. The abscissa of the graph represents the pressure of the air in pounds per square inch gauge that is produced by the compressor. The ordinant of the graph represents the volumetric output of the compressor in cubic feet per minute.
Line A is a graph of the performance of a traditional air compressor having a one horse power electrical motor. Line B is a graph of the performance of a traditional air compressor having a two horse power electrical motor. Line C represents a graph of the performance of an air compressor having a one horse power electrical motor and utilizing the present invention.
As can be seen from FIG. 6, in the lower pressure range for the air compressors, the compressor having a one horse power motor utilizing the present invention has a performance that is substantially the same as a traditional compressor having a two horse power motor. At 40 pounds pressure the compressor of this invention produces approximately 13/4 cubic feet per minute more volumetric outputs than the traditional compressor having a one horse power motor.
The performance of the one horse power compressor utilizing the present invention is superior to the performance of the traditional one horse power compressor over substantially the entire operating range for the compressors. At the maximum rated output for the compressors the performance of the one horse power compressor utilizing the present invention is substantially the same as the performance for the traditional one horse power compressor. Thus, as can be seen in FIG. 6 the present invention substantially improves the performance of an air compressor over a substantial portion of the operating range for the compressor. It should be noted that this increase in performance is accomplished without increasing the horse power rating for the motor that drives the compressor.
Having described the invention in detail with reference to the drawings, it will be understood that such specifications are given for the sake of explanation. Various modifications and substitutions other than those cited can be made without departing from the spirit and scope of the invention as defined by the following claims. | A method and apparatus for controlling a motor is disclosed in this application. A means for loading the motor is provided and the loading means is operatively connected to the motor. A variable drive means is operatively connected between the motor and the drive means. The variable drive means is capable of changing the loading on the motor. A sensing means is provided for actuating the variable drive means so the loading on the motor can be varied to keep the motor operating at substantially the maximum capacity of the motor. | 5 |
[0001] This application claims priority from U.S. provisional applications Nos. 61/330,993 and 61/331,092, both filed May 4, 2010.
FIELD OF THE INVENTION
[0002] The present application relates generally to providing pay per view content for Internet video clients including but not limited to TVs.
BACKGROUND OF THE INVENTION
[0003] Internet access through TVs is typically provided by essentially programming the TV as though it were a computer executing a browser. Such Internet access is thus uncontrolled except as a firewall or filtering program might block certain sites.
[0004] As understood herein, uncontrolled Internet access may not be desirable in the context of a TV. A firewall or filtering program may not always be installed on the TV and even when one is installed, access remains much more uncontrolled than conventional TV programming traditionally has expected. Also, a locally installed filter can be unloaded or defeated by a user.
[0005] Accordingly, uncontrolled Internet access has several drawbacks. From a viewer's standpoint, exposure to inappropriate subject matter particularly when young viewers are watching is one concern; a much lower threshold of quality screening is another. That is, while many TV shows might not be widely considered as “quality” shows, nonetheless a TV program is usually much more selectively screened than, say, an Internet video. The expectations of TV viewers for such higher level quality screening as a consequence cannot be met by simply providing unfettered Internet access through the TV. Furthermore, TV-related entities, from content providers, manufacturers, and carriers, in most cases derive no benefit from the extension of TV to the Internet, such as, e.g., might be derived, as understood herein, by pay-per-view based on one or more options.
SUMMARY OF THE INVENTION
[0006] Accordingly, a content server assembly has at least one processor, at least one network interface communicating with the processor to establish communication between the processor and a wide area network, and at least one computer readable storage medium accessible to the processor and bearing logic causing the processor to provide a respective client-unique service user identification token (SUIT) to a management server for each of plural user accounts identified by the management server. The processor receives from a client device accessing the content server assembly over a network path obtained by the client device from the management server at least a request for a content list and the SUIT. Also, the processor determines whether the SUIT is valid and responsive to a determination that the SUIT is valid and only if the SUIT is valid, provides a content list to the client device.
[0007] In some embodiments the content server assembly can include a content server and a proxy server communicating with the content server and interfacing the content server with the client device. An access type indicator in the proxy server, such as a three-value software flag, may indicate that the client device is authorized to access individual content asset titles.
[0008] If desired, the content server assembly can receive a request for a content list and information pertaining thereto and transmit the content list to the client device only if both the SUIT and a user token received from the client device are valid. The user token can be originated by a management server to indicate that the client device is properly enrolled with the management server. In response to the request for a content list and a determination that the user token indicates that the client device is properly enrolled, the content server assembly can use the SUIT to ascertain an account of the client device. Token validity may be executed by verifying that the token appears in a table of authorized tokens accessible to the content server assembly. The content server assembly may receive a copy of the user token from the management server and may transmit a user interface (UI) form to the client device usable for generating billing information to the account of the client device responsive to receiving a selection of content from the client device. The content list can present pay per view (PPV) entries, with each entry representing an individual content asset title available for purchase by the client device.
[0009] In another aspect, a consumer electronic (CE) device includes a housing, a display on the housing, a network interface, and a processor in the housing controlling the display and communicating with the Internet through the network interface. The processor executes logic that includes receiving from a management server a service list and user token. The service list has entries corresponding to content server assemblies. The logic also includes receiving from the input device a selection of an entry on the list and responsive to the selection sending the user token and selection to the management server. The processor receives from the management server a network path corresponding to the entry on the list that was selected along with a service user identification token (SUIT) and responsive to receiving the network path and SUIT, establishes communication with the content server assembly using the network path. The processor provides to the content server assembly the SUIT and a request for a content listing.
[0010] In yet another aspect, a management server has a processor, network interface communicating with the processor to establish communication between the processor and a wide area network, and a computer readable storage medium accessible to the processor and bearing logic causing the processor to receive from a content server assembly a service user identification token (SUIT) unique to a client account associated with at least one client device. The processor receives from the client device a selection of the content server assembly from a service list provided by the management server to the client device and also receives from the client device a user token. The processor then determines whether the user token is valid and only if the user token is valid, sends to the client device a network path to the content server assembly and the SUIT.
[0011] The details of the present invention, both as to its structure and operation, can best be understood in reference to the accompanying drawings, in which like reference numerals refer to like parts, and in which:
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a block diagram of an example system in accordance with present principles;
[0013] FIG. 2 is a block diagram of another example system in accordance with present principles;
[0014] FIG. 3 is a flow chart of example registration logic according to present principles;
[0015] FIG. 4 is a flow chart of further example registration logic;
[0016] FIG. 5 is a flow chart of example management server logic;
[0017] FIG. 6 is a flow chart of example proxy server logic; and
[0018] FIG. 7 is a flow chart of example post-registration client logic.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0019] Referring initially to FIG. 1 , a consumer electronics (CE) device 12 such as a TV, game player, video disk player, camera, digital clock radio, mobile telephone, personal digital assistant, laptop computer, etc. includes a portable lightweight plastic housing 14 bearing a digital processor 16 . The processor 16 can control a visual display 18 and an audible display 20 such as one or more speakers.
[0020] To undertake present principles, the processor 16 may access one or more computer readable storage media such as but not limited to RAM-based storage 22 (e.g., a chip implementing dynamic random access memory (DRAM)) or flash memory 24 . Among other things, in example non-limiting embodiments video thumbnails may be stored on the RAM 22 while the below-described service list and tokens as well as user interface icons may be stored on the flash 24 . Software code implementing present logic executable by the CE device 12 may also be stored on one of the memories shown to undertake present principles.
[0021] The processor 16 can receive user input signals from various input devices 26 , including a remote control device, a point and click device such as a mouse, a keypad, etc. A TV tuner 28 may be provided in some implementations particularly when the CE device is embodied by a TV to receive TV signals from a source such as a set-top box, satellite receiver, cable head end, terrestrial TV signal antenna, etc. Signals from the tuner 28 are sent to the processor 16 for presentation on the display 18 and speakers 20 .
[0022] As shown in FIG. 1 , a network interface 30 such as a wired or wireless modem or wireless telephony transceiver communicates with the processor 16 to provide connectivity to a management server 32 on the Internet and to one or more content servers 34 . If desired, each content server 34 may be associated with a respective proxy server 35 which interfaces the content server 34 with the device 12 , it being understood that the below-described proxy server logic may be consolidated within the content server 34 and a physically separate proxy server eliminated if desired. In any case, the servers 32 34 , 35 have respective processors 32 a, 34 a, 35 a accessing respective non-transitory computer readable storage media 32 b, 34 b, 35 b which may be, without limitation, disk-based and/or solid state storage. The servers communicate with a wide area network such as the Internet via respective network interfaces 32 c, 34 c, 35 c. It is to be understood in view of disclosure below that the CE device 12 particularly when implemented by a non-PC device such as a TV or game console or camera can communicate only with the management server 32 and with content servers 34 that appear on a service list provided to the processor 16 by the management server 32 , with the service list not being modifiable by the processor 16 .
[0023] FIG. 2 shows a CE device 12 a that in all essential respects is identical to the device 12 shown in FIG. 1 , except that a network interface 30 a is not located within the device housing 14 a but instead is supported in a separate Internet link module housing 36 that may be mounted on the device housing 14 a.
[0024] Now referring to FIG. 3 , example registration logic can be seen. Commencing at block 38 the CE device 12 sends account information to the management server 32 preferably using a secure means of communication such as secure socket layer (SSL). Accordingly, it will be appreciated that private key-public key encryption need not be executed by the processor 16 to reduce the processing requirements thereon. The account information may include, e.g., user name and password.
[0025] At block 40 , the CE device 12 sends to the management server 32 its unique identification, again using SSL so that no key encryption is required. The value of the ID can be preloaded at the factory or at client creation time and may be a unique “fingerprint” of the CE device 12 , for example, a secret concatenation of its model number and serial number.
[0026] Moving to block 42 , if the ID of the CE device is on an approved list of IDs it is associated by the management server in a database with one or more service lists that have been approved for the CE device 12 . This in effect creates an “association token”, which correlates the CE device ID with the approved service lists. A service list contains the network addresses of the content servers 34 that are approved for providing content to the CE device 12 and that typically are portal sites established by business partners of the provisioner of the Internet access logic or module discussed herein. Since the portals are established by approved providers they can be designed to contain only links to approved content as discussed below and thus can be made devoid of hyperlinks to elsewhere on the Internet.
[0027] Now referring to FIG. 4 , at block 44 the management server 32 provides account data of the client 12 to the content servers 34 (in some embodiments, with respective proxy servers 35 ) that have entered into a business relationship with the entity associated with the management server 32 for the purpose of providing Internet video content to the client device 12 . Moving to block 46 , each content server/proxy server combination provides a client-unique service user identification token (SUIT) to the management server 32 . In preferred implementations a single client account is associated by each respective content server/proxy server combination with a single unique SUIT even though, as explained further below, the client account may be associated with multiple devices which may access a content server.
[0028] The logic moves from block 46 to block 48 wherein each client account is associated with one or more devices 12 and with services that are approved for that client account. Each device 12 in the client account has access to the user token and service list so that a user may access the features herein using any device registered to his account. The services which are approved for the account typically are agreed on by the entities associated with the management server and the content servers as part of the above-mentioned business relationship, and may include, e.g., “basic content only”, “access premium pay-per-view (PPV) content by individual title, or by service, or by category”, etc. Also, in some embodiments to facilitate easily adding a new device to the user's account, a unique key such as a four digit key is provided to the client device 12 employed by the user to access the management server.
[0029] With this feature, if the user associated with the client device purchases a new device at decision diamond 50 and chooses to add the new device to the existing account, at block 52 the management server 32 can prompt the user to enter the key provided at block 48 . This prompt may occur when, for instance, the user first starts up the new device and the device is programmed to access the management server 32 , with the server 32 downloading a prompt page to the new device. Upon entry of the key and after verifying at block 54 that the key is correct, the new device is added (by, e.g., entering the device serial number and if desired model number into a table of the user's account devices accessible to the management server 32 ) to the user's account and provided access to the service list and user token. The device information added to the account may be automatically sent by the device to the server or discovered by the server. In any case, the various content servers 34 /proxy servers 35 may be provided with the updated account information at block 56 so that they to know what devices are authorized access for a particular user account.
[0030] FIG. 5 illustrates example management server 32 logic post-registration when the client device 12 seeks to access content from a content server 34 . Commencing at block 58 , a user interface is presented on a client device in use indicating that content is available through the TV tuner and the approved content servers (e.g., the service list), one of which sources may be selected by a user of the client device. At block 60 , a selection of one of the content servers on the above-described service list is received from the client device along with the user token and the identification of the device. At block 62 the server 32 verifies that the user token is correct and that the identification of the device is authorized as part of the user account and if so, the network path to the requested content server (or its proxy server when one is provided) is downloaded to the requesting device at block 64 , along with the SUIT appertaining to the user account that was provided by the content server at block 46 in FIG. 4 .
[0031] The logic of a proxy server 35 that is associated with the selected content server whose network path was provided to the client device at block 64 may be seen in FIG. 6 . At block 66 the proxy server receives from its content server or other source affiliated with the entity operating the pair of servers 34 / 35 a global client access type applicable to all users, or a user-by-user access type. The access type in one implementation is selected from one of three types, namely, access content by content category, by service, or by individual asset (title). Examples of content categories include sports, first run movies, classic movies, cooking shows, weather shows, etc. Examples of services include specific names of Internet-based audio-video service providers which may be accessed through the content server 34 . Block 68 indicates that the proxy server 35 sets a flag indicating which access type pertains to each particular user (or when a global access type is implemented, which access type pertains to all users).
[0032] Then, at block 70 a client device request for content is received from a client device using the network path provided by the management server at block 64 of FIG. 5 . As part of the request the client provides the SUIT originated by the content server 34 which the client device received from the management server in FIG. 5 , and it also provides the user token from the management server to indicate that the device is properly enrolled with the management server. The request essentially is in two parts, namely, a request for a content list and a request for information pertaining to the content on the list. The request may be relayed by the proxy server 35 to its associated content server 34 .
[0033] Block 72 indicates that in response to the client request, assuming the user token indicates that the requesting device is properly enrolled (with the associated content server 34 in some embodiments executing this initial verification), the proxy server 35 uses the SUIT to ascertain the account of the requesting device the proxy server 35 . Or, the proxy server 35 may relay the SUIT to the content server 34 , which verifies that the SUIT is valid. If either the user token or SUIT is not valid, an error message can be returned to the client device. Token validity may be as simple as verifying that the provided user token/SUIT appears in a table of authorized tokens accessible to the verifying server.
[0034] Assuming both the user token and SUIT are valid, the proxy server 35 checks the access type flag associated with the requesting device account. Based on the flag value the content server 34 /proxy server 35 assembly returns to the client device 12 the appropriate content list, namely, a list of individual asset titles, a list of approved content categories, or a list of approved services, along with explanatory information regarding the elements of the list.
[0035] When the list returned to the client presents PPV asset titles or PPV categories or PPV services and the client selects an element on the list, in response at block 74 a user interface (UI) form is sent to the client device for display thereof. The form may be simply a prompt to verify that the user wishes to access content for which the user will be billed, or it may include a credit card entry field, etc. Regardless, the information from the form as selected or input by the user through the client device is received at block 76 . The proxy server 35 may then generate electronic billing information that is provided to the user of the client device using the account information related to the user, or this task may be executed by the content server 34 or other affiliated server.
[0036] FIG. 7 shows related logic implemented by the client device 12 and can be more easily understood in light of the disclosure above. At block 80 the above-described service list is presented on the display 18 and a user selection of an Internet source on the list is received at block 82 from, e.g., the input device 26 . The user token and selection are sent to the management server 32 at block 84 . In response, at block 86 the SUIT associated with the selected source and the path to the related content server (proxy server) are received from the management server. Then at block 88 the path is invoked to establish communication with the selected content server (proxy server) and the SUIT and user token provided as described above.
[0037] Proceeding to block 90 , the client device also requests of the content server (proxy server) the content list and information related thereto. Assuming the user token and SUIT both pass the validity tests mentioned above, at block 92 the requested list and information are presented on the display 18 . A user selection of an entry on the list is received at block 94 and sent to the proxy server 35 , with the returned content being received and displayed at block 96 .
[0038] As indicated above, the entity associated with a particular content server 34 can limit access by a user to particular categories, or services, or individual asset titles, with the above-mentioned flag set in the proxy server 35 accordingly. In an example non-limiting embodiment when a client device 12 makes a request for the assets in a specific category an STSgetAuthorization request is made by the proxy server 35 with a parameter type set to “category” and a parameter identifier set to the name of the category, including the hierarchy of its parent categories. In an extended markup language (XML) response, the content server 34 can specify if the client device has authorization to access the requested category. A successful response may contain an authorization tag with a result attribute having a value of “success”. In contrast, if the user is not authorized for the category, the result XML can contain an authorization tag with the result attribute having a value of fail. The XML may also contain a form tag, which may contain one background image, one or more message tags to display to the user, and an account registration progress tag to indicate the registration status. The message or one of the messages may contain a placeholder for the registration code. The proxy server 35 can insert the registration code into this placeholder. The message(s) may be localized in the user's language when a language parameter is included in the STSgetAuthorization request.
[0039] The above process is substantially the same when the content server 34 sets the access type to “service” or “individual asset title”, with the flag being set accordingly and the messages changed to appropriately reflect “service” or “individual asset title”.
[0040] Below are examples of the messages discussed above by way of illustration and not by way of limitation:
[0000]
STSgetAuthorizationRequest
id
Name of a service, fully qualified category
name, or ID number of an asset. For a nested
category, the semi-colon (;) character is used
as the delimiter to indicate parent and child
relationship. The top-level parent category's
name comes first. Each category name may
be encoded before it is used to make the fully
qualified name by escaping the backslash
characters by repeating them (\ → \\) and
replacing the semi-colon characters with a
backslash and the character s (; → \s) (string
maxlen 37 for asset and service and length of
a fully qualified category name varies).
service_name
Name of a service and is the same as ‘id’ if
the request type is service (string maximum
length (maxlen) 37 for service).
provider
Name of a service provider (string maxlen
37).
suit
Service User ID Token (SUIT) - A provider-
generated value for the identity of the user
that is associated with the token request. The
possible values are an actual SUIT and
NO_SUIT (string maxlen 64).
sig
A signature generated on the URL string
using an MD5 hash [Error! Reference
source not found.] of the portion prior to
the ‘&sig=’ concatenated with a secret string
value unique to each Service Provider
(string).
reg_status
Flag indicating whether the client is
registered with the entity associated with the
management server (string maxlen 5).
Possible values are true or false.
type
Type of data access requested by the user
(service, category, or asset) for authorization
(string maxlen 32).
request_timestamp
A string containing the date and time that the
authorization request was issued (string
maxlen 64).
Optional fields:
language
User's preferred language as set on the
attached television (string maxlen 2).
ip_address
Internet location of the IPTV product (string
maxlen 32).
version
An unsigned integer field indicating the
version and/or format of the message
structure. If omitted, version 0 is assumed
(string maxlen 5).
[0041] Response to STSgetAuthorizationRequest
[0042] Two tags are returned along with the command, namely, an authorization tag defining the result of user account verification and a code tag indicating the status of the command.
[0000]
tags:
authorization
Defines the result of user account verification
with the Service Provider (string maxlen 64).
Optional tags:
playlist
A container for the play list information about
an asset.
asset
A single asset record that groups information
regarding the location of the video content be
retrieved by the client. This field is not
required for service or category GET
response, and is not required when the user is
not authorized (string maxlen 64).
contents
Defines the location of the video content to
be retrieved by the client. This field is not
required for service or category GET
response, and is not required when the user is
not authorized (string maxlen 64).
speed_check
Defines the location of the media content for
link speed check to be retrieved by the client.
This field is not required for service or
category GET response, and is not required
when the user is not authorized (string
maxlen 64).
source
Defines the URL where the content media is
available for a successful asset GET request.
This field is not required for service or
category GET response, and is not required
when the user is not authorized (string
maxlen 64).
categories
A hierarchy of categories offered by a Service
Provider (string maxlen 128).
category
A category offered by a Service Provider
(string maxlen 128).
service
A service offered by a Service Provider
(string maxlen 64).
form
Defines a background image and a list of text
message(s) to be displayed for an
unregistered user.
message
The command code status meaning for a
failed authorization (string maxlen 128).
background
Defines a background image to be displayed
for a failed authorization. The background
image must be PNG type 6, TrueColor,
interlace method 0 or JPEG JFIF type.
reg_in_progress
Flag indicating user registration is in progress
(string maxlen 5). Possible values are true or
false.
[0043] While the particular ENABLEMENT OF PREMIUM CONTENT FOR INTERNET VIDEO CLIENT is herein shown and described in detail, it is to be understood that the subject matter which is encompassed by the present invention is limited only by the claims. | A device is enabled to display Internet TV by accessing a management server and receiving back from the server a user token and a service list of predefined content servers. A user can select a content server on the service list which causes the device to upload its user token to the management server, which in turn sends back the network path to the content server along with a content server-user-unique service token (SUIT) that the device uses to access the content on the content server, in some embodiments on per-title PPV access, per-content category PPV access, or per-service PPV access. | 7 |
RELATED APPLICATIONS
This application claims priority to provisional application Ser. No. 61/074,883, entitled “AN ANTENNA PEDESTAL INCLUDING A PORTAL STRUCTURE PROVIDING ELECTROMAGNETIC INTERFERENCE SHIELDING FEATURES,” filed Jun. 23, 2008, which is incorporated herein in its entirety.
GOVERNMENT SPONSORED RESEARCH
This invention was made with Government support under Contract Number N00039-04-C-0012 awarded by the Department of the Navy. The United States Government has certain rights in the invention.
BACKGROUND
Electromagnetic interference (EMI) can cause disruption to electrical systems. One way to prevent EMI from affecting electronic circuitry is to shield the electronic circuit, a technique generally known as EMI shielding. Typically, EMI is performed by encasing the electronic components in metal having no gaps in the metal that would allow EMI to penetrate, for example, a Faraday cage. In general, a continuous metal contact is provided to ensure EMI shielding.
SUMMARY
In one aspect, a portal structure to access an inner cavity of a body includes a threaded structure disposed around a portal accessing the inner cavity of the body, a cover comprising threads configured to engage the threads of the threaded structure and a lid comprising a metal and configured to be placed over the port and held securely by the cover to provide electromagnetic interference (EMI) shielding when the cover and the threaded structure are screwed together.
In another aspect, a portal structure to access an inner cavity of a body includes a threaded structure disposed around a portal accessing the inner cavity of the body; and a cover that includes threads configured to engage the threads of the threaded structure and configured to be placed over the port to provide electromagnetic interference (EMI) shielding when the cover and the threaded structure are screwed together.
In a further aspect, an antenna pedestal includes a body having an inner cavity. The antenna pedestal includes a portal structure to access the inner cavity of the antenna pedestal. The portal structure also includes a threaded structure disposed around a portal accessing the inner cavity and comprising threads and a cover comprising threads configured to engage the threads of the threaded structure to close the portal.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a prior art diagram of an environment of a radar system.
FIG. 2 is a side-view of an antenna pedestal.
FIG. 3 is a diagram of an antenna pedestal of FIG. 2 taken along the reference line A-A.
FIG. 4 is a diagram of a portal structure.
FIG. 5A is a top view of the portal structure.
FIG. 5B is a cross-section view of the portal structure taken along the reference line B-B.
FIG. 6 is a view of an internal cavity of the antenna pedestal.
FIG. 7 is a cross-section view of the antenna pedestal of FIG. 2 taken along the reference line C-C.
FIG. 8 is a cross-section view of the antenna pedestal of FIG. 2 taken along the reference line D-D.
FIG. 9 is view of a rotary cable configuration.
FIG. 10 is viewed of an example of a rotary connector.
FIG. 11A is a partial cross-sectional view of a first connector portion.
FIG. 11B is a partial cross-sectional view of a second connector portion.
FIG. 11C is partial cross-sectional view of the rotary connector with the first connector portion separated from the second connector portion by springs.
FIGS. 12A , 12 B are views of another example of the rotary connector as a Y-connector FIG. 13 is a view of further example of the rotary connector as a T-connector.
FIG. 14 is a view of a still further example of a rotary connector as an elbow connector.
DETAILED DESCRIPTION
Referring to FIG. 1 , in a signal environment 10 , a system 12 may be susceptible to electromagnetic interference (EMI) 18 emanating from an EMI source 16 . The system may be a radar system, a communications system and so forth. The EMI source may be a radar system, a communications system and so forth. In one particular environment, aboard a naval vessel, the EMI source may be a communications antenna in close proximity to the system 12 . In one example, the system 12 includes an antenna 24 attached to the antenna pedestal 22 and cables 26 providing and receiving electrical signals with the system 12 . The cables 26 may provide, for example, electrical signals to motors (not shown) that orientate the antenna 24 to point in various directions. In this configuration the cables 26 are exposed to EMI and the flow of the electrical signals may be disrupted. Therefore, the cables 26 providing the electrical signals to the system 12 are EMI shielded. One solution is to place the cables within the antenna pedestal 22 . However, placing cables within the antenna pedestal 22 poses significant problems in that access to the cables 26 is limited in order to affect repairs, for example. Also, by being within the antenna pedestal 22 the cables 26 need to be able to move in at least two axes of rotation.
Referring to FIGS. 2 and 3 , an antenna pedestal 50 includes a base section 52 , a trunk section 56 , an arm section 62 and an antenna attachment section 68 for connecting to an antenna (not shown). The antenna pedestal 50 may move in at least two axes of rotation to orientate the antenna. For example, the arm section 62 is configured to rotate about an axis, J. The rotation about the J-axis forms an angle θ, which is measured from an axis J′ that is perpendicular to the J-axis. In one example, θ ranges from −45° to 45° (90° total). The antenna attachment section 68 is configured to rotate about an axis K. The rotation about the K-axis forms an angle α, which is measured from an axis K′ that is perpendicular to the K axis. In one example, a ranges from −30° to 120° (150° total).
The antenna pedestal 50 includes an inner cavity (an inner cavity 180 in FIG. 6 ) that is EMI shielded. For example, the base section 52 , the trunk section 56 , the arm section 62 and the antenna attachment section 68 form a continuous metal barrier protecting components within the inner cavity of the antenna pedestal 50 from EMI.
The antenna pedestal 50 includes a number of portal structures 72 a - 72 c used to access components within the inner cavity 180 of the antenna pedestal 50 that contribute to EMI shielding. For example, the trunk section 56 includes the portal structures 72 a , 72 b , the arm section 62 includes the portal structure 72 c and the antenna attachment section 68 includes the portal structures 72 d , 72 e.
Referring to FIG. 4 , the portal structure 72 includes a cover 82 having threads (not shown), a lid 86 including metal and a threaded structure 92 including threads 96 formed around a portal 100 . The portal structure 72 also includes a wire 98 connected to the cover 82 by an anchor 102 and connected to the threaded structure 92 by an anchor 104 . The lid 86 is shaped to completely cover the portal 100 to provide a continuous metal-to-metal contact for EMT shielding. In one example, the cover 82 and the threaded structure 92 are similar to ajar cover and jar arrangement (e.g., a BALL® Jar). For example, by screwing the cover 82 to the threaded structure 92 , the lid 86 is held fixed to completely cover the portal 100 thereby forming an EMI shield. In other examples, the threaded structure 92 includes threads within an interior of the portal 100 while the cover 82 includes the threads 92 on its exterior (not shown). In one example, the lid 86 is made of a metal including a metal alloy. The threaded structure 92 being attached to the antenna pedestal 50 is also made of metal including a metal alloy to contribute to EMI shielding. Since the lid 86 completely covers the portal 100 and is contact with the threaded structure 92 , there is not a requirement that the cover 82 be composed of metal. For example, the cover 82 including its threads (not shown) may be made of nylon. In other examples, the lid 86 is integrated with the cover 82 to form a single piece.
Prior art techniques of portal structures, used covers that required ten to twenty screws that took minutes to remove and replace. Because the screws were small, over time they were easily lost by technicians. By using the portal structure 72 , technicians are able to access key components within the antenna pedestal 50 for maintenance or repair within seconds. FIG. 5A is a top view of the portal structure 72 and FIG. 5B is a cross-sectional view of the portal structure 72 taken along the reference line B-B.
Referring to FIGS. 6 to 8 , within a cavity 180 of the antenna pedestal 50 , rotary cables 190 run from the base 52 through the antenna attachment section 68 and contain wires (e.g., wires 200 a - 200 d in FIG. 9 ) to carry signals to and from various electrical components within the antenna pedestal 50 . For example, rotary cables 190 provide electrical signals to motor assemblies (e.g., a motor assembly 184 a and a motor assembly 184 b ) that control rotation of the antenna about the J-axis and the K-axis. In one example, the motor assemblies 184 a , 184 b include an elevation motor along with a rotor and a stator. As will be shown, rotary connectors such as a rotary connector 192 ( FIGS. 6 , 8 and 10 ) and a rotary connector 292 ( FIGS. 8 , 12 A and 12 B), for example, allow portions of the rotary cables 190 to rotate to accommodate movements by the antenna pedestal 50 about the J-axis and the K-axis. In other examples, rotary connectors 392 , 492 ( FIGS. 13 and 14 ) may also be used.
Referring to FIGS. 9 and 10 , one example of a rotary cable 190 is a rotary cable 190 ′. The rotary cable 190 ′ includes the rotary connector 192 including a first connector portion 194 , a second connector portion 196 and springs (e.g., a spring 210 a and a spring 210 b ( FIG. 11C )). The rotary cable 190 ′ also includes cable hoses 198 a , 198 b . The cable hose 198 a is connected to the first connector portion 194 and the cable hose 198 b is connected to the second connector portion 196 . The cable hoses 198 a , 198 b , are similar to garden hoses except the cable hoses 198 a , 198 b are EMI shielded and carry wires instead of water. For example, cable hoses 198 a , 198 b are EMI shielded cable hoses that carry wires 200 a - 200 d . In one example, wires 200 a - 200 d supply power to the motor assemblies (e.g., the motor assemblies 184 a , 184 b ) that rotate the antenna pedestal 50 . Like garden hoses, cables hoses 198 a , 198 b individually cannot rotate more than a few degrees about their longitudinal axis M. However, as will be shown further below, the rotary connector 192 ( FIG. 10 ) allows for rotation of one cable hose 198 a or 198 b about the longitudinal axis M while the other cable hose 198 b or 198 a remains substantially fixed with respect to the longitudinal axis M while ensuring that wires 200 a - 200 d are EMI shielded.
Referring to FIG. 11A , the first connector portion 194 includes threads 204 a for connection with the cable hose 198 a . The first connector portion 194 is shaped to form a channel 206 a to carry the wires 200 a - 200 d.
Referring to FIG. 11B , the second connector 196 includes threads 204 b for connection with the cable hose 198 b . The second connector portion 196 is shaped to form a channel 206 b to carry the wires 200 a - 200 d . The second connector portion 196 is also shaped to form grooves (e.g., a groove 208 a and a groove 208 b ). Each groove 208 a , 208 b runs in a concentric circle about longitudinal axis M.
Referring to FIG. 11C , the first connector portion 194 and the second connector portion 196 are separated by springs (e.g., a spring 210 a and a spring 210 b ). The springs 210 a , 210 b ensures that at any point in time there is a continuous metal-to-metal contact between the first connector portion 194 and the second connector portion 196 . In one example, the springs 210 a , 210 b include a metal. In one example, springs 210 a , 210 b include a metal alloy. In other examples, the springs 210 a , 210 b are made of beryllium copper.
In one example, the first connector portion 194 rotates about the longitudinal axis M while the second connector portion 196 is substantially fixed relative to the longitudinal axis M. In another example, the second connector portion 196 rotates about the longitudinal axis M while the first connector portion 194 is substantially fixed relative to the longitudinal axis M.
FIGS. 12A and 12B are views of another example of a rotary connector, a rotary connector 292 . In this example, the rotary connector 292 is a Y-connector. The rotary connector 292 includes a first connector portion 294 and a second connector portion 296 . The first connector portion 294 includes two ports (a port 298 a and a port 298 b ) for connection to two cable hoses (not shown). In one example, the first connector portion 294 rotates about a longitudinal axis P while the second connector portion 296 is substantially fixed relative to the longitudinal axis P. In another example, the second connector portion 296 rotates about the longitudinal axis P while the first connector portion 294 is substantially fixed relative to the longitudinal axis P.
FIG. 13 is a view of further example of a rotary connector, a rotary connector 392 . In this example, the rotary connector 392 is a T-connector. The rotary connector 392 includes a first connector portion 394 and a second connector portion 396 . The first connector portion 394 includes two ports (a port 398 a and a port 398 b ) for connection to two cable hoses (not shown). In one example, the first connector portion 394 rotates about a longitudinal axis Q while the second connector portion 396 is substantially fixed relative to the longitudinal axis P. In another example, the second connector portion 396 rotates about the longitudinal axis Q while the first connector portion 394 is substantially fixed relative to the longitudinal axis P.
FIG. 14 is a view of a still further example of a rotary connector as a rotary connector 492 . In this example, the rotary connector 492 is an elbow connector. The rotary connector 492 includes a first connector portion 494 and a second connector portion 496 . In one example, the first connector portion 494 rotates about a longitudinal axis R while the second connector portion 496 is substantially fixed relative to the longitudinal axis R. In another example, the second connector portion 496 rotates about the longitudinal axis R while the first connector portion 494 is substantially fixed relative to the longitudinal axis R.
Elements of different embodiments described herein may be combined to form other embodiments not specifically set forth above. Other embodiments not specifically described herein are also within the scope of the following claims. | In one aspect, an antenna pedestal includes a body having an inner cavity. The antenna pedestal includes a portal structure to access the inner cavity of the antenna pedestal. The portal structure also includes a threaded structure disposed around a portal accessing the inner cavity and comprising threads and a cover comprising threads configured to engage the threads of the threaded structure to close the portal. In another aspect, a portal structure to access an inner cavity of a body includes a threaded structure disposed around a portal accessing the inner cavity of the body and a cover that includes threads configured to engage the threads of the threaded structure and configured to be placed over the port to provide electromagnetic interference (EMI) shielding when the cover and the threaded structure are screwed together. One or more of the aspects above may be used for EMI shielding in antenna pedestals. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application incorporates by reference and claims priority to U.S. Provisional Application 61/780,875 filed on Mar. 13, 2013.
BACKGROUND OF THE INVENTION
The present subject matter relates generally to a hydraulic dampener system, wherein a user controls the degree of dampening by rotating a cylindrical housing of the system.
Conventional hydraulic dampeners incorporate an adjustment means to control the flow of hydraulic fluid, which in turn controls the degree of dampening. Conventional adjustment techniques typically include the application of a separate tool to adjust the dampening effect. Further, conventional designs only allow a user to adjust the dampening before the dampener is mounted into place. Once the dampener is installed, a user cannot adjust the dampening without removing the dampener from the mounting. After which, a user must remount and reinstall the dampener.
In other dampeners, the degree of dampening may be adjusted by the rotation of the dampener housing, but only when the dampener is in a fully closed position. In these dampeners, corresponding mating portions in the housing and piston mate only at the extreme end of the piston's travel within the housing. As a result, the degree of dampening can only be modified when in the “closed” position. This limitation is less than ideal and can be improved upon.
Accordingly, there is a need for a dampening system wherein the degree of dampening may be altered while the dampener is in use.
BRIEF SUMMARY OF THE INVENTION
The present disclosure provides improved hydraulic dampener systems. The systems disclosed here are designed for a sealed self-contained hydraulic dampener in which the dampening may be controlled by rotating the cylindrical housing body of the system. For example, rotating the housing body in one direction may increase the dampening and rotating the housing in the opposite direction may decrease the dampening. The system allows the rate of dampening to be controlled when the system is at rest or in motion. In addition, the dampening setting does not change unless it is intentionally adjusted. Further, the dampener system may be mounted and used in a horizontal or vertical orientation.
In an example, the system includes a piston including a front disk and a back disk, wherein a washer is positioned between the front disk and back disk. The washer may include triangular tabs molded onto a surface of the washer that face the front disk of the piston. In an example, the tabs interact with at least a portion of the perimeter of the front disk of the piston.
The dampener system may also include a piston housing including a cylindrical housing, a housing front end, and a housing back end, wherein the housing back end includes a housing back end opening for the shaft connected to the piston to exit the housing. The housing front end and the housing back end may include grooves for the ends of the cylindrical housing to engage. In other words, the housing front end and housing back may be free and not integrally formed with the cylindrical housing, therefore, allowing the cylindrical housing to float and rotate freely. The system may include a plurality of seals, such as O-rings, that are positioned within the grooves of the housing front end and the housing back end. The seals serve to seal the hydraulic fluid within the interior of the cylindrical housing. The seals may include lubrication that is applied during assembly, wherein the lubrication serves to ensure a seal between the cylindrical body and the housing front end and the housing back end. Lubrication also enables a user to easily twist and rotate the housing to alter the degree of dampening. Similarly, the seals may be made from self-lubricating materials that help to maintain easy rotation of the housing throughout the life of the system.
As the cylindrical housing is rotated, the inner diameter of the housing body frictionally engages with the outer diameter of the washer. As a result, the washer rotates with the housing body. As the washer rotates, the tabs on the washer come in contact with a portion of the piston front disk. At that point, further rotation of the housing body results in rotation of the piston. As the piston is rotated, the threaded central opening of the piston is screwed along a threaded portion of the shaft, which may include a slot having a milled radius. Hydraulic fluid passes from one side of the piston to the other by flowing through a passage created by the slot. As the piston is screwed along the thread of the shaft, hydraulic fluid flow is decreased as a function of the size of the passage decreasing, thus increasing the dampening. As the rotation of the cylindrical housing is reversed, the piston is screwed in the opposite direction, increasing the size of the passage, and decreasing the dampening.
In an example, the piston back disk includes notches along the perimeter of the back disk to act as by-pass valves on the return stroke of the dampener. Hydraulic fluid passes through the notches and cause the washer to curl slightly, allowing the hydraulic fluid to pass from one side of the piston to the other side without any dampening action.
The present disclosure provides a hydraulic dampener system comprising a threaded central opening, a piston front disk, and a piston back disk, wherein a measurement across a front face of the piston front disk is smaller than a diameter of the piston back disk, wherein the measurement across the front face extends through the threaded center opening. In an example, the piston back disk includes at least one notch in its perimeter.
The system includes a washer positioned between the piston front disk and the piston back disk, wherein the washer includes a front side and back side, wherein the front side faces the piston front disk and the back side faces the piston back disk, wherein the front side includes at least one washer tab. The diameter of the piston back disk is smaller than a diameter of the washer. In an example, the washer tab is triangular.
The system also includes a shaft including a shaft back end and shaft front end, wherein the shaft front end includes a threaded surface to engage the threaded central opening of the piston, wherein the shaft front end further includes a slot. In an example, the slot includes a milled radius.
When the threaded central opening of the piston engages the threaded surface of the shaft front end, a passage is formed through the slot from the piston front disk to the piston back disk such that, when the threaded central opening of the piston is rotated along the threaded surface of the shaft, a size of the passage is altered.
In addition, when the washer is rotated, the washer tab engages with a portion of the piston front disk to rotate the piston along the threaded surface of the shaft front end. For example, the piston front disk includes two flat sections along its perimeter, wherein, when the washer is rotated, the washer tab engages with one of the flat sections to rotate the piston along the threaded surface of the shaft front end.
In an example, the system includes a piston housing including a cylindrical body to receive the piston, the washer, and a portion of the shaft, wherein an inner diameter of the piston housing is sized to frictionally engage an outer diameter of the washer. The piston housing also includes a housing front end and a housing back end including a housing back end opening, wherein the shaft back end extends through the housing back end opening. When the piston housing is rotated, the piston washer is rotated such that the tab engages with a portion of the piston front disk.
The present disclosure also provides a hydraulic dampener system including a piston including a threaded central opening, a piston front disk, and a piston back disk, wherein a measurement across a front face of the piston front disk is smaller than a diameter of the piston back disk, wherein the measurement across the front face extends through the threaded center opening. The system also includes a washer positioned between the piston front disk and the piston back disk, wherein the washer includes a front side and back side, wherein the front side faces the piston front disk and the back side faces the piston back disk, wherein the front side includes at least one washer tab. In addition, the system includes a shaft including a shaft back end and shaft front end, wherein the shaft front end includes a threaded surface to engage the threaded central opening of the piston, wherein the shaft front end further includes a slot.
The system also includes a piston housing including a cylindrical body to receive the piston and a portion of the shaft, wherein an inner diameter of the piston housing is sized to frictionally engage an outer diameter of the washer. The piston housing also includes a housing front end and a housing back end, wherein the back end includes a housing back end opening, wherein the shaft back end extends through the housing back end opening.
When the piston housing is rotated, the piston washer is rotated such that the tab engages with a portion of the piston front disk. When the piston washer is rotated while the tab is engaged with the piston front disk, the piston is rotated along the threaded portion of the shaft front end. Also, when the piston is rotated along the threaded portion of the shaft front end, the size of a passage formed between the threaded central opening of the piston and the slot is altered, wherein the size of the passage restricts the amount of hydraulic fluid that passes from one side of the piston to the other side.
In an example, the piston back disk includes at least one notch in its perimeter. In another example, a perimeter of the piston front disk includes two flat sections, wherein, when the washer is rotated, the washer tab engages with one of the flat sections to rotate the piston along the threaded surface of the shaft front end.
In an example, the housing cylinder includes hydraulic fluid, wherein, when the piston is moved toward the housing back end, hydraulic fluid moves through a notch in the perimeter of the piston back disk and bends a portion of the washer away from the piston back disk. When the piston is moved toward the housing front end, the washer may cover a notch in the perimeter of the piston back disk, preventing hydraulic fluid from flowing through the notch.
In an example, the washer tab is triangular. In another example, the slot includes a milled radius.
The housing front end and the housing back end may not be integrally formed with the cylindrical body of the piston housing.
The housing front end may include a front end groove to receive a body front end of the cylindrical body, and the housing back end may include a back end groove to receive a body back end of the cylindrical body.
An advantage of the present system is providing a hydraulic dampener that may be adjusted during use to achieve the desired dampening. In other words, the dampener does not need to be uninstalled to adjust the dampening degree.
A further advantage of the present system is that a user may both increase or decrease the dampening effect of the hydraulic dampener.
Another advantage of the present system is providing a means to control the speed of dampening when the dampener is at rest or in motion over the entire length of the stroke.
Additional objects, advantages and novel features of the examples will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following description and the accompanying drawings or may be learned by production or operation of the examples. The objects and advantages of the concepts may be realized and attained by means of the methodologies, instrumentalities and combinations particularly pointed out in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The drawing figures depict one or more implementations in accord with the present concepts, by way of example only, not by way of limitations. In the figures, like reference numerals refer to the same or similar elements.
FIG. 1 is a perspective view of a washer, piston, and shaft.
FIG. 2 is a perspective view of an example the washer disclosed herein.
FIG. 3 is a cross-sectional side view of an example of a hydraulic dampener according to the teachings presented herein.
FIG. 4A is a front view of an example of the piston washer in combination with the piston second disk, as the washer is rotated counter-clockwise.
FIG. 4B is a front view of an example of the piston washer in combination with the piston second disk, as the washer is rotated clockwise.
FIG. 5A is a side cross-sectional view of an embodiment of the piston in combination with the shaft, as the piston is away from the housing front end.
FIG. 5B is a side cross-sectional view of an embodiment the piston in combination with the shaft, as the piston is moved towards the housing front end.
DETAILED DESCRIPTION OF THE INVENTION
The present disclosure provides hydraulic dampener systems 100 including a piston 50 , a washer 15 , and a shaft 2 , as shown in FIG. 1 . The piston 50 includes a threaded central opening 28 that is configured to engage a threaded surface of the shaft 2 . In an example, the threaded surface of the shaft 2 and the threaded central opening 28 of the piston 50 define a class 5 interference fit. The piston 50 may be made of any suitable material including, but not limited to, metal, plastic, resin, among others. For example, the piston 50 may be made of fiberglass reinforced nylon, such as, Zytel®.
The piston 50 includes a piston front disk 17 and a piston back disk 20 . As shown in FIG. 1 , a measurement taken across the face of the piston front disk 17 and extending through the threaded central opening 28 is smaller than a diameter of the piston back disk 20 . In an example, the reduced size is achieved because the piston front disk 17 includes two flat sections 38 along its perimeter. Although, it is contemplated that there are numerous designs for the piston front disk 17 that would provide a reduced size to accomplish the advantages described herein. For example, the piston front disk 17 may include an ovular shape, wherein a measurement across at least one section of the piston front disk 17 is less than the diameter of the piston back disk 20 . Alternatively, the piston front disk 17 may be circular with sections cut away from the perimeter of the piston front disk 17 .
The piston back disk 20 may be generally circular. In an example, the piston back disk 20 includes at least one notch 32 in its perimeter, as is discussed further below.
The system 100 also includes a washer 15 positioned between the piston front disk 17 and the piston back disk 20 , as shown in FIGS. 5A-5B . The washer may be made of rubber, plastic, or combinations thereof, among other materials. The washer 15 includes a front side 34 and a back side 36 , wherein the front side 34 faces the piston front disk 17 and the back side 36 faces the piston back disk 20 . The diameter of the piston back disk 20 is smaller than a diameter of the washer 15 .
The front side 34 of the washer 15 includes at least one washer tab 16 . The tab 16 may be any suitable shape including, but not limited to, square, triangular, circular, spherical, or rectangular, among other shapes. In the example shown in FIG. 2 , the washer tab 16 is triangular. The tab 16 protrudes from a surface of the front side 34 of the washer 15 . The extent of the protrusion is such that the tab 16 is capable of engaging at least one portion of the piston front disk 17 . The tab 16 may be made from the same or different material as the washer 15 .
The system 100 also includes a shaft 2 including a shaft front end 19 and a shaft back end 22 , wherein the shaft front end 19 includes a threaded surface to engage the threaded central opening 28 of the piston 50 . The shaft 2 is typically a rod shape. The shaft 2 may be made of any suitable material including, but not limited to, metal, plastic, or combinations thereof, among other materials. The threaded surface of the shaft front end 19 may include class 5 interference threads, which ensure that the threaded central opening 28 does not drift to a different position along the shaft front end 19 without user manipulation, such as, physically rotating the cylindrical body 6 .
In the example wherein the piston front disk 17 includes at least two flat sections 38 , when the washer 15 is rotated, the washer tab 16 engages with one of the flat sections 38 to rotate the piston 50 along the threaded surface of the shaft front end 19 , as shown in FIGS. 4A-4B .
The shaft front end 19 further includes a slot 18 , as shown in FIGS. 5A-5B . In an example, the slot 18 includes a milled radius. When the threaded central opening 28 of the piston 50 engages the threaded surface of the shaft front end 19 , a passage 30 is formed through the slot 18 from the piston front disk 17 to the piston back disk 20 , as shown in FIGS. 5A-5B . When the threaded central opening 28 is rotated along the threaded surface of the shaft front end 19 , a size of the passage 30 is altered.
As shown in FIG. 3 , the system 100 may include a piston housing 40 including a cylindrical body 6 to receive the piston 50 , washer 15 , and a portion of the shaft 2 , wherein an inner diameter of the cylindrical body 6 is sized to frictionally engage an outer diameter of the washer 15 . The piston housing 40 also includes a housing front end 4 and a housing back end 8 including a housing back end opening 26 , wherein the shaft back end 22 extends through the housing back end opening 26 . The cylindrical body 6 may not be integrally formed with the housing front end 4 . As a result, the cylindrical body 6 is free to float allowing a user to grasp and rotate the cylindrical body 6 independent of the housing front end 4 . The cylindrical body 6 may also not be integrally formed with the housing back end 8 .
The housing front end 4 may include a front end groove 24 to receive a body front end 5 of the cylindrical body 6 . Similarly, the housing back end 8 may include a back end groove 9 to receive a body back end 10 of the cylindrical body 6 . A seal 7 , such as an O-ring, may be positioned between the housing front end 4 and the cylindrical body 6 , and between the housing back end 8 and the cylindrical body 6 , as shown in FIG. 3 . The seals 7 may be impregnated with lubricant during the molding process, such that the lubricant “weeps” to the surface of the seal 7 in order to maintain contact between the outer diameter of the seal 7 and the inner diameter of the cylindrical body 6 . Without the continual weeping of the lubricant from the seal 7 , the seal 7 may take a compression set in contact with the inner diameter of the cylindrical tube 6 and produce enough friction to hinder twisting of the cylindrical body 6 .
The housing back end 8 may also include a shaft seal 11 including molded wipers on the inner diameter of the shaft seal that seals and compresses shaft 2 between the housing back end 8 and a rear bearing 12 . The rear bearing 12 may also include a groove for receiving a seal 7 , such as an O-ring, as shown in FIG. 3 . The housing back end 8 , the shaft seal 11 , and the rear bearing 12 may be held in position by indentation 14 within the cylindrical body 6 , as shown in FIG. 3 .
The housing front end 4 may include a housing front end opening 3 that may be used for mounting the dampener system 100 . Similarly, the shaft back end 22 may include a shaft opening 1 that may be used for mounting the dampener system 100 .
When the cylindrical body 6 of the piston housing 40 is rotated, the washer 15 is rotated because the washer 15 is frictionally engaged with an inner surface of the cylindrical body 6 of the piston housing 40 . As the washer 15 is rotated, the tab 16 engages with a portion of the piston front disk 17 . When the washer 15 is rotated while the tab 16 is engaged with the piston front disk 17 , the piston 50 is rotated along the threaded portion of the shaft front end 19 . Further, when the piston 50 is rotated along the threaded portion of the shaft front end 19 , the size of a passage 30 formed between the threaded central opening 28 of the piston 50 and the slot 18 is altered, wherein the size of the passage 30 restricts the amount of hydraulic fluid that passes from one side of the piston 50 to the other side. Therefore, by rotating the cylindrical body 6 of the piston housing 40 , a user may alter the dampening effect of the system 100 .
As shown in FIG. 4A , when the cylindrical body 6 is rotated counter-clockwise, the washer 15 rotates with the cylindrical body 6 because the washer 15 is frictionally engaged with the cylindrical body 6 . As a result, the washer tabs 16 engage the flat section 38 of the piston front disk 17 , thereby rotating the piston 50 along the threaded surface of the shaft front end 19 . As a result, the size of passage 30 may be increased and the dampening is decreased. In contrast, as shown in FIG. 4B , when the cylindrical body 6 is rotated clockwise, the size of the passage 30 is decreased, which increases the dampening effect. Of course, it is contemplated that the cylindrical body 6 may be rotated counter-clockwise to increase the size of the passage 30 .
In an example, the piston back disk 20 includes at least one notch 32 in its perimeter. For example, the housing cylinder 6 may include hydraulic fluid, wherein, when the piston 50 is moved toward the housing back end 8 , as shown in FIG. 5A , hydraulic fluid moves through a notch 32 in the perimeter of the piston back disk 20 and bends a portion of the washer 15 away from the piston back disk 20 . When the piston 50 is moved toward the housing front end 4 , as shown in FIG. 5B , the washer 15 may cover a notch 32 in the perimeter of the piston back disk 20 , preventing hydraulic fluid from flowing through the at least one notch 32 , and allowing hydraulic fluid to pass only through passage 30 . As a result, the return stroke of the piston 50 allows the hydraulic fluid to flow through both the slot 18 and the at least one notch 32 , which reduces the dampening when compared to the forward stroke. The notch 32 or notches 32 may take on various sizes and shapes, which can affect the volume of hydraulic fluid that passes through the at least one notch 32 on the return stroke.
It should be noted that various changes and modifications to the embodiments described herein will be apparent to those skilled in the art. Such changes and modifications may be made without departing from the spirit and scope of the present invention and without diminishing its attendant advantages. For example, various embodiments of the method and portable electronic device may be provided based on various combinations of the features and functions from the subject matter provided herein. | The present disclosure provides hydraulic dampening systems wherein the dampening effect may be controlled by rotating a body of the dampener, after the dampening system has been installed and in use. The system includes a piston including a front disk and back disk, wherein the front disk has a reduced diameter with respect to the back disk. A washer is positioned between the two piston disks, wherein the diameter of the washer is greater than the piston back disk, wherein the washer includes at least two protruding tabs. The washer is frictionally engaged with the body of the dampener. As the body is rotated, the washer is rotated such that the washer tabs engage at least a portion of the piston front disk to rotate the piston along a threaded surface of a shaft of the system. | 5 |
CROSS-REFERENCE TO RELATED APPLICATION
The present application claims priority to and the benefit of Korean Patent Application No. 10-2016-0028484 filed Mar. 9, 2016, which is incorporated herein by reference in its entirety.
FIELD
The present disclosure relates to an automatic transmission for a vehicle. More particularly, the present disclosure relates to a planetary gear train of an automatic transmission for a vehicle.
BACKGROUND
The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Generally, an automatic transmission achieving more speed stages has been developed to enhance fuel economy and optimize drivability.
Such an automatic transmission achieving more speed stages is preferred to maximize power performance and driving efficiency according to downsizing of an engine. Particularly, we have discovered that a high efficiency multiple-speeds transmission having excellent linearity of step ratios can be used as an index closely related to drivability such as acceleration before and after shift and rhythmical engine speed in order to secure competitiveness in the automatic transmission field.
However, in the automatic transmission, as the number of speed stages increase, the number of internal components increase, and as a result, mountability, cost, weight, transmission efficiency, and the like may still deteriorate.
Accordingly, development of a planetary gear train which may achieve maximum efficiency with a small number of components can increase a fuel efficiency enhancement effect through the multiple-speeds.
In this aspect, in recent years, 8-speed automatic transmissions tend to be implemented and the research and development of a planetary gear train capable of implementing more speed stages has also been actively conducted.
However, since a conventional 8-speed automatic transmission has gear ratio span of 6.5-7.5 (gear ratio span is an important factor for securing linearity of step ratios), improvement of power performance and fuel economy may not be very good.
In addition, if an 8-speed automatic transmission has gear ratio span larger than 9.0, it is hard to secure linearity of step ratios. Therefore, driving efficiency of an engine and drivability of a vehicle may be deteriorated.
Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
SUMMARY
The present disclosure has been made in an effort to provide a planetary gear train of an automatic transmission for a vehicle having advantages of improving power delivery performance and fuel economy by achieving at least ten forward speed stages and one reverse speed stage, and widening gear ratio span and of securing linearity of step ratios.
One embodiment of the present disclosure provides a planetary gear train of an automatic transmission for a vehicle having advantages of maintaining durability of pinion shafts by avoiding applying load to planet carriers at stopped states when the vehicle runs at a high speed stage.
A planetary gear train of an automatic transmission for a vehicle according to an embodiment of the present disclosure may include: an input shaft receiving torque of an engine; an output shaft outputting torque; a first planetary gear set including first, second, and third rotation elements; a second planetary gear set including fourth, fifth, and sixth rotation elements; a third planetary gear set including seventh, eighth, and ninth rotation elements; a fourth planetary gear set including tenth, eleventh, and twelfth rotation elements; a first shaft connected to the first rotation element; a second shaft connected to the second rotation element and directly connected to the input shaft; a third shaft connecting the third rotation element, the sixth rotation element and the tenth rotation element with each other; a fourth shaft connected to the fourth rotation element and selectively connected to the second shaft; a fifth shaft connecting the fifth rotation element with the ninth rotation element and selectively connected to the second shaft; and a sixth shaft connecting the seventh rotation element with the twelfth rotation element.
The first shaft and the sixth shaft may be selectively connected to a transmission housing, the fifth shaft may be selectively connected to the transmission housing in a state of being disconnected from the second shaft, and the planetary gear train may further include a seventh shaft connected to the eighth rotation element and selectively connected to the third shaft; and an eighth shaft connected to the eleventh rotation element, selectively connected to the seventh shaft, and directly connected to the output shaft.
The first, second, and third rotation elements of the first planetary gear set may be a first sun gear, a first planet carrier, and a first ring gear, the fourth, fifth, and sixth rotation elements of the second planetary gear set may be a second sun gear, a second planet carrier, and a second ring gear, the seventh, eighth, and ninth rotation elements of the third planetary gear set may be a third sun gear, a third planet carrier, and a third ring gear, and a tenth, eleventh, and twelfth rotation elements of the fourth planetary gear set may be a fourth sun gear, a fourth planet carrier, and a fourth ring gear, respectively.
The first, second, third, and fourth planetary gear sets may be disposed in a sequence of the first planetary gear set, the second planetary gear set, the third planetary gear set, and the fourth planetary gear set from the engine.
The planetary gear train may further include: a first clutch selectively connecting the seventh shaft with the eighth shaft; a second clutch selectively connecting the second shaft with the fifth shaft; a third clutch selectively connecting the second shaft with the fourth shaft; a fourth clutch selectively connecting the third shaft with the seventh shaft; a first brake selectively connecting the fifth shaft with the transmission housing; a second brake selectively connecting the sixth shaft with the transmission housing; and a third brake selectively connecting the first shaft with the transmission housing.
A planetary gear train of an automatic transmission for a vehicle according to another embodiment of the present disclosure may include: an input shaft receiving torque of an engine; an output shaft outputting torque; a first planetary gear set including first, second, and third rotation elements; a second planetary gear set including fourth, fifth, and sixth rotation elements; a third planetary gear set including seventh, eighth, and ninth rotation elements; and a fourth planetary gear set including tenth, eleventh, and twelfth rotation elements, wherein the input shaft is directly connected to the second rotation element, the output shaft is directly connected to the eleventh rotation element, the first rotation element is selectively connected to a transmission housing, the third rotation element is directly connected to the sixth rotation element and the tenth rotation element, the fifth rotation element is directly connected to the ninth rotation element and is selectively connected to the transmission housing, and the seventh rotation element is directly connected to the twelfth rotation element and is selectively connected to the transmission housing.
The second rotation element may be selectively connected to the fourth rotation element, the second rotation element may be selectively connected to the fifth rotation element when the fifth rotation element is disconnected from the transmission housing, and the eighth rotation element may be selectively connected to the third rotation element or the eleventh rotation element.
The first, second, and third rotation elements of the first planetary gear set may be a first sun gear, a first planet carrier, and a first ring gear, the fourth, fifth, and sixth rotation elements of the second planetary gear set may be a second sun gear, a second planet carrier, and a second ring gear, the seventh, eighth, and ninth rotation elements of the third planetary gear set may be a third sun gear, a third planet carrier, and a third ring gear, and the tenth, eleventh, and twelfth rotation elements of the fourth planetary gear set may be a fourth sun gear, a fourth planet carrier, and a fourth ring gear, respectively.
The first, second, third, and fourth planetary gear sets may be disposed in a sequence of the first planetary gear set, the second planetary gear set, the third planetary gear set, and the fourth planetary gear set from the engine.
The planetary gear train may further include: a first clutch selectively connecting the eighth rotation element with the eleventh rotation element; a second clutch selectively connecting the second rotation element with the fifth rotation element; a third clutch selectively connecting the second rotation element with the fourth rotation element; a fourth clutch selectively connecting the sixth rotation element with the eighth rotation element; a first brake selectively connecting the fifth rotation element with the transmission housing; a second brake selectively connecting the seventh rotation element with the transmission housing; and a third brake selectively connecting the first rotation element with the transmission housing.
An embodiment of the present disclosure may achieve at least ten forward speed stages and one reverse speed stage by combining four planetary gear sets being simple planetary gear sets with seven control elements.
In addition, since gear ratio span greater than 10.0 is secured, driving efficiency of the engine may be maximized. In addition, since linearity of step ratios can be secured due to multiple speed stages, drivability such as acceleration before and after shift, rhythmical engine speed, and the like may be improved.
In addition, durability of pinion shafts connected to pinion gears may be maintained due to smooth lubrication by avoiding applying load to planet carriers at stopped states when the vehicle runs at a high forward speed stage.
DRAWINGS
In order that the disclosure may be well understood, there will now be described various forms thereof, given by way of example, reference being made to the accompanying drawings, in which:
FIG. 1 is a schematic diagram of a planetary gear train according to an embodiment of the present disclosure.
FIG. 2 is an operation chart of control elements at each speed stage in the planetary gear train according to an embodiment of the present disclosure.
The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.
DESCRIPTION OF SYMBOLS
B 1 , B 2 , B 3 : first, second, and third brakes
C 1 , C 2 , C 3 , C 4 : first, second, third, and fourth clutches
PG 1 , PG 2 , PG 3 , PG 4 : first, second, third, and fourth planetary gear sets
S 1 , S 2 , S 3 , S 4 : first, second, third, and fourth sun gears
PC 1 , PC 2 , PC 3 , PC 4 : first, second, third, and fourth planet carriers
R 1 , R 2 , R 3 , R 4 : first, second, third, and fourth ring gears
IS: input shaft OS: output shaft
TM 1 , TM 2 , TM 3 , TM 4 , TM 5 , TM 6 , TM 7 , TM 8 : first, second, third, fourth, fifth, sixth, seventh, and eighth shafts
DETAILED DESCRIPTION
The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.
Hereinafter, an embodiment of the present disclosure will be described in detail with reference to the accompanying drawings.
However, parts which are not related with the description are omitted for clearly describing the embodiments of the present disclosure and like reference numerals refer to like or similar elements throughout the specification.
In the following description, dividing names of components into first, second, and the like is to divide the names because the names of the components are the same as each other and an order thereof is not particularly limited. As used herein, “connect” and its variants includes connection for transmission of force such as torque, e.g., a first component connected to a second component for rotation therewith, or a first component connected to a second component for fixation of the components, e.g. braking or resisting movement.
FIG. 1 is a schematic diagram of a planetary gear train according to an embodiment of the present disclosure.
Referring to FIG. 1 , a planetary gear train according to first embodiment of the present disclosure includes first, second, third, and fourth planetary gear sets PG 1 , PG 2 , PG 3 , and PG 4 disposed on the same axis, an input shaft IS, an output shaft OS, eight shafts TM 1 to TM 8 connected to at least one of rotation elements of the first, second, third, and fourth planetary gear sets PG 1 , PG 2 , PG 3 , and PG 4 , four clutches C 1 to C 4 and three brakes B 1 to B 3 that are control elements, and a transmission housing H.
Torque input from the input shaft IS is changed by cooperation of the first, second, third, and fourth planetary gear sets PG 1 , PG 2 , PG 3 , and PG 4 , and the changed torque is output through the output shaft OS.
Herein, the planetary gear sets are disposed in a sequence of the first, second, third, and fourth planetary gear sets PG 1 , PG 2 , PG 3 , and PG 4 from the engine.
The input shaft IS is an input member and torque from a crankshaft of the engine is torque-converted through a torque converter to be input into the input shaft IS.
The output shaft OS is an output member, is disposed in parallel with the input shaft IS, and transmits driving torque to a driving wheel through a differential apparatus.
The first planetary gear set PG 1 is a single pinion planetary gear set and includes a first sun gear S 1 , a first planet carrier PC 1 rotatably supporting a first pinion P 1 that is externally meshed with the first sun gear S 1 , and a first ring gear R 1 that is internally meshed with the first pinion P 1 respectively as first, second, and third rotation elements N 1 , N 2 , and N 3 .
The second planetary gear set PG 2 is a single pinion planetary gear set and includes a second sun gear S 2 , a second planet carrier PC 2 rotatably supporting a second pinion P 2 that is externally meshed with the second sun gear S 2 , and a second ring gear R 2 that is internally meshed with the second pinion P 2 respectively as fourth, fifth, and sixth rotation elements N 4 , N 5 , and N 6 .
The third planetary gear set PG 3 is a single pinion planetary gear set and includes a third sun gear S 3 , a third planet carrier PC 3 rotatably supporting a third pinion P 3 that is externally meshed with the third sun gear S 3 , and a third ring gear R 3 that is internally meshed with the third pinion P 3 respectively as seventh, eighth, and ninth rotation elements N 7 , N 8 , and N 9 .
The fourth planetary gear set PG 4 is a single pinion planetary gear set and includes a fourth sun gear S 4 , a fourth planet carrier PC 4 rotatably supporting a fourth pinion P 4 that is externally meshed with the fourth sun gear S 4 , and a fourth ring gear R 4 that is internally meshed with the fourth pinion P 4 respectively as tenth, eleventh, and twelfth rotation elements N 10 , N 11 , and N 12 .
The third rotation element N 3 is directly connected to the sixth rotation element N 6 and the tenth rotation element N 10 , the fifth rotation element N 5 is directly connected to the ninth rotation element N 9 , and the seventh rotation element N 7 is directly connected to the twelfth rotation element N 12 by three shafts among the eight shafts TM 1 to TM 8 .
The eight shafts TM 1 to TM 8 will be described in further detail.
The eight shafts TM 1 to TM 8 directly connect a plurality of rotation elements among the rotation elements of the planetary gear sets PG 1 , PG 2 , PG 3 , and PG 4 , and are rotation members that are directly connected to any one rotation element (or more) of the planetary gear sets PG 1 , PG 2 , PG 3 , and PG 4 and rotate with the any one rotation element to transmit torque, or are fixed members that directly connect any one rotation element of the planetary gear sets PG 1 , PG 2 , PG 3 , and PG 4 to the transmission housing H to fix the any one rotation element.
The first shaft TM 1 is connected to the first rotation element N 1 (first sun gear S 1 ) and is selectively connected to the transmission housing H.
The second shaft TM 2 is connected to the second rotation element N 2 (first planet carrier PC 1 ) and is directly connected to the input shaft IS so as to be operated as an input element continuously.
The third shaft TM 3 directly connects the third rotation element N 3 (first ring gear R 1 ), the sixth rotation element N 6 (second ring gear R 2 ) and the tenth rotation element N 10 (fourth sun gear S 4 ) with each other.
The fourth shaft TM 4 is connected to the fourth rotation element N 4 (second sun gear S 2 ) and is selectively connected to the second shaft TM 2 that is directly connected to the input shaft IS so as to be operated as a selective input element.
The fifth shaft TM 5 directly connects the fifth rotation element N 5 (second planet carrier PC 2 ) with the ninth rotation element N 9 (third ring gear R 3 ), and is selectively connected to the second shaft TM 2 directly connected to the input shaft IS so as to be operated as a selective input element or is selectively connected to the transmission housing H.
The sixth shaft TM 6 directly connects the seventh rotation element N 7 (third sun gear S 3 ) with the twelfth rotation element N 12 (fourth ring gear R 4 ) and is selectively connected to the transmission housing H.
The seventh shaft TM 7 is connected to the eighth rotation element N 8 (third planet carrier PC 3 ) and is selectively connected to the third shaft TM 3 .
The eighth shaft TM 8 is connected to the eleventh rotation element N 11 (fourth planet carrier PC 4 ), is selectively connected to the seventh shaft TM 7 , and is directly connected to the output shaft OS so as to be operated as an output element continuously.
In addition, four clutches C 1 , C 2 , C 3 , and C 4 are disposed at portions at which any two shafts among the eight shafts TM 1 to TM 8 including the input shaft IS and the output shaft OS are selectively connected to each other.
In addition, three brakes B 1 , B 2 , and B 3 are disposed at portions at which any one shaft among the eight shafts TM 1 to TM 8 is selectively connected to the transmission housing H.
Arrangements of the four clutches C 1 to C 4 and the three brakes B 1 to B 3 are described in detail.
The first clutch C 1 is disposed between the seventh shaft TM 7 and the eighth shaft TM 8 and selectively connects the seventh shaft TM 7 with the eighth shaft TM 8 .
The second clutch C 2 is disposed between the second shaft TM 2 and the fifth shaft TM 5 and selectively connects the second shaft TM 2 with the fifth shaft TM 5 .
The third clutch C 3 is disposed between the second shaft TM 2 and the fourth shaft TM 4 and selectively connects the second shaft TM 2 with the fourth shaft TM 4 .
The fourth clutch C 4 is disposed between the third shaft TM 3 and the seventh shaft TM 7 and selectively connects the third shaft TM 3 with the seventh shaft TM 7 .
The first brake B 1 is disposed between the fifth shaft TM 5 and the transmission housing H and selectively connects the fifth shaft TM 5 with the transmission housing H.
The second brake B 2 is disposed between the sixth shaft TM 6 and the transmission housing H and selectively connects the sixth shaft TM 6 with the transmission housing H.
The third brake B 3 is disposed between the first shaft TM 1 and the transmission housing H and selectively connects the first shaft TM 1 with the transmission housing H.
The control elements including the first, second, third, and fourth clutches C 1 , C 2 , C 3 , and C 4 and the first, second, and third brakes B 1 , B 2 , and B 3 may be multi-plate friction elements of wet type that are operated by hydraulic pressure, although other types of clutches or brakes may also be employed.
FIG. 2 is an operation chart of control elements at each speed stage in the planetary gear train according to an exemplary embodiment of the present disclosure.
Referring to FIG. 2 , three control elements among the first, second, third, and fourth clutches C 1 , C 2 , C 3 , and C 4 and the first, second, and third brakes B 1 , B 2 , and B 3 that are control elements are operated at each speed stage in the planetary gear train according to the embodiment of the present disclosure. The embodiment of the present disclosure can achieve one reverse speed stage and ten forward speed stages.
The second brake B 2 and the second and fourth clutches C 2 and C 4 are simultaneously operated at a first forward speed stage D 1 .
In a state that the second shaft TM 2 is connected to the fifth shaft TM 5 by operation of the second clutch C 2 and the third shaft TM 3 is connected to the seventh shaft TM 7 by operation of the fourth clutch C 4 , torque of the input shaft IS is input to the second shaft TM 2 and the fifth shaft TM 5 . In addition, the sixth shaft TM 6 is operated as the fixed element by operation of the second brake B 2 . Therefore, the torque of the input shaft IS is shifted into the first forward speed stage, and the first forward speed stage is output to the output shaft OS connected to the eighth shaft TM 8 .
The second brake B 2 and the second and third clutches C 2 and C 3 are simultaneously operated at a second forward speed stage D 2 .
In a state that the second shaft TM 2 is connected to the fifth shaft TM 5 by operation of the second clutch C 2 and the second shaft TM 2 is connected to the fourth shaft TM 4 by operation of the third clutch C 3 , the torque of the input shaft IS is input to the second shaft TM 2 , the fifth shaft TM 5 and the fourth shaft TM 4 . In addition, the sixth shaft TM 6 is operated as the fixed element by operation of the second brake B 2 . Therefore, the torque of the input shaft IS is shifted into the second forward speed stage, and the second forward speed stage is output to the output shaft OS connected to the eighth shaft TM 8 .
The second and third brakes B 2 and B 3 and the second clutch C 2 are simultaneously operated at a third forward speed stage D 3 .
In a state that the second shaft TM 2 is connected to the fifth shaft TM 5 by operation of the second clutch C 2 , the torque of the input shaft IS is input to the second shaft TM 2 and the fifth shaft TM 5 . In addition, the sixth shaft TM 6 and the first shaft TM 1 are operated as the fixed elements by operation of the second and third brakes B 2 and B 3 . Therefore, the torque of the input shaft IS is shifted into the third forward speed stage, and the third forward speed stage is output to the output shaft OS connected to the eighth shaft TM 8 .
The second brake B 2 and the first and second clutches C 1 and C 2 are simultaneously operated at a fourth forward speed stage D 4 .
In a state that the seventh shaft TM 7 is connected to the eighth shaft TM 8 by operation of the first clutch C 1 and the second shaft TM 2 is connected to the fifth shaft TM 5 by operation of the second clutch C 2 , the torque of the input shaft IS is input to the second shaft TM 2 and the fifth shaft TM 5 . In addition, the sixth shaft TM 6 is operated as the fixed element by operation of the second brake B 2 . Therefore, the torque of the input shaft IS is shifted into the fourth forward speed stage, and the fourth forward speed stage is output to the output shaft OS connected to the eighth shaft TM 8 .
The third brake B 3 and the first and second clutches C 1 and C 2 are simultaneously operated at a fifth forward speed stage D 5 .
In a state that the seventh shaft TM 7 is connected to the eighth shaft TM 8 by operation of the first clutch C 1 and the second shaft TM 2 is connected to the fifth shaft TM 5 by operation of the second clutch C 2 , the torque of the input shaft IS is input to the second shaft TM 2 and the fifth shaft TM 5 . In addition, the first shaft TM 1 is operated as the fixed element by operation of the third brake B 3 . Therefore, the torque of the input shaft IS is shifted into the fifth forward speed stage, and the fifth forward speed stage is output to the output shaft OS connected to the eighth shaft TM 8 .
The first, second, and third clutches C 1 , C 2 , and C 3 are simultaneously operated at a sixth forward speed stage D 6 .
Since the seventh shaft TM 7 is connected to the eighth shaft TM 8 by operation of the first clutch C 1 , the second shaft TM 2 is connected to the fifth shaft TM 5 by operation of the second clutch C 2 , and the second shaft TM 2 is connected to the fourth shaft TM 4 by operation of the third clutch C 3 , all the planetary gear sets become lock-up states. In this state, the torque of the input shaft IS is input to the second shaft TM 2 , the fifth shaft TM 5 and the fourth shaft TM 4 , and the sixth forward speed stage is output to the output shaft OS connected to the eighth shaft TM 8 . Rotation speed that is the same as rotation speed of the input shaft IS is output at the sixth forward speed stage.
The third brake B 3 and the first and third clutches C 1 and C 3 are simultaneously operated at a seventh forward speed stage D 7 .
In a state that the seventh shaft TM 7 is connected to the eighth shaft TM 8 by operation of the first clutch C 1 and the second shaft TM 2 is connected to the fourth shaft TM 4 by operation of the third clutch C 3 , the torque of the input shaft IS is input to the second shaft TM 2 and the fourth shaft TM 4 . In addition, the first shaft TM 1 is operated as the fixed element by operation of the third brake B 3 . Therefore, the torque of the input shaft IS is shifted into the seventh forward speed stage, and the seventh forward speed stage is output to the output shaft OS connected to the eighth shaft TM 8 .
The third brake B 3 and the first and fourth clutches C 1 and C 4 are simultaneously operated at an eighth forward speed stage D 8 .
In a state that the seventh shaft TM 7 is connected to the eighth shaft TM 8 by operation of the first clutch C 1 and the third shaft TM 3 is connected to the seventh shaft TM 7 by operation of the fourth clutch C 4 , the torque of the input shaft IS is input to the second shaft TM 2 . In addition, the first shaft TM 1 is operated as the fixed element by operation of the third brake B 3 . Therefore, the torque of the input shaft IS is shifted into the eighth forward speed stage, and the eighth forward speed stage is output to the output shaft OS connected to the eighth shaft TM 8 .
The third brake B 3 and the third and fourth clutches C 3 and C 4 are simultaneously operated at a ninth forward speed stage D 9 .
In a state that the second shaft TM 2 is connected to the fourth shaft TM 4 by operation of the third clutch C 3 and the third shaft TM 3 is connected to the seventh shaft TM 7 by operation of the fourth clutch C 4 , the torque of the input shaft IS is input to the second shaft TM 2 and the fourth shaft TM 4 . In addition, the first shaft TM 1 is operated as the fixed element by operation of the third brake B 3 . Therefore, the torque of the input shaft IS is shifted into the ninth forward speed stage, and the ninth forward speed stage is output to the output shaft OS connected to the eighth shaft TM 8 .
The third brake B 3 and the second and fourth clutches C 2 and C 4 are simultaneously operated at a tenth forward speed stage D 10 .
In a state that the second shaft TM 2 is connected to the fifth shaft TM 5 by operation of the second clutch C 2 and the third shaft TM 3 is connected to the seventh shaft TM 7 by operation of the fourth clutch C 4 , the torque of the input shaft IS is input to the second shaft TM 2 and the fifth shaft TM 5 . In addition, the first shaft TM 1 is operated as the fixed element by operation of the third brake B 3 . Therefore, the torque of the input shaft IS is shifted into the tenth forward speed stage, and the tenth forward speed stage is output to the output shaft OS connected to the eighth shaft TM 8 .
The first and second brakes B 1 and B 2 and the third clutch C 3 are simultaneously operated at a reverse speed stage REV.
In a state that the second shaft TM 2 is connected to the fourth shaft TM 4 by operation of the third clutch C 3 , the torque of the input shaft IS is input to the second shaft TM 2 and the fourth shaft TM 4 . In addition, the fifth shaft TM 5 and the sixth shaft TM 6 are operated as the fixed elements by operation of the first and second brakes B 1 and B 2 . Therefore, the torque of the input shaft IS is shifted into the reverse speed stage, and the reverse speed stage is output to the output shaft OS connected to the eighth shaft TM 8 .
The planetary gear train according to the embodiments of the present disclosure may achieve at least ten forward speed stage and one reverse speed stage by combining four planetary gear sets PG 1 , PG 2 , PG 3 , and PG 4 with the four clutches C 1 , C 2 , C 3 , and C 4 and the three brakes B 1 , B 2 , and B 3 .
In addition, since a gear ratio span greater than 10.0 is secured, driving efficiency of the engine may be maximized.
In addition, since linearity of step ratios can be secured due to multiple speed stages, drivability such as acceleration before and after shift, rhythmical engine speed, and on the like may be improved.
In addition, durability of pinion shafts connected to pinion gears may be maintained due to smooth lubrication by avoiding applying load to planet carriers at stopped states when the vehicle runs at a high forward speed stage (e.g., higher than or equal to the seventh forward speed stage).
While this disclosure has been described in connection with what is presently considered to be practical embodiments, it is to be understood that the disclosure is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. The description of the disclosure is merely exemplary in nature and, thus, variations that do not depart from the substance of the disclosure are intended to be within the scope of the disclosure. Such variations are not to be regarded as a departure from the spirit and scope of the disclosure. | A planetary gear train of an automatic transmission for a vehicle may include: an input shaft receiving torque of an engine; an output shaft outputting changed torque; a first planetary gear set including first, second, and third rotation elements; a second planetary gear set including fourth, fifth, and sixth rotation elements; a third planetary gear set including seventh, eighth, and ninth rotation elements; a fourth planetary gear set including tenth, eleventh, and twelfth rotation elements. The planetary gear train improves power delivery performance and fuel economy by achieving at least ten forward speed stages and one reverse speed stage, and widens gear ratio span and secures linearity of step ratios. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to a cooling system for an internal combustion engine wherein a liquid coolant is permitted to boil and the vapor used as a vehicle for removing heat from the engine, and more specifically to such a system which maintains the cooling circuit essentially free of contaminating air while minimizing both the complexity of the system and the amount of additional coolant which must be stored in an auxiliary reservoir which forms a vital part of the system.
2. Description of the Prior Art
In currently used `water cooled` internal combustion engine such as shown in FIG. 1 of the drawings, the engine coolant (liquid) is forcefully circulated by a water pump, through a cooling circuit including the engine coolant jacket and an air cooled radiator. This type of system encounters the drawback that a large volume of water is required to be circulated between the radiator and the coolant jacket in order to remove the necessary amount of heat. Further, due to the large mass of water inherently required, the warm-up characteristics of the engine are undesirably sluggish. For example, if the temperature difference between the inlet and discharge ports of the coolant jacket is 4 degrees, the amount of heat which 1 Kgm of water may effectively remove from the engine under such conditions is 4 Kcal. Accordingly, in the case of an engine having 1800 cc displacement (by way of example) is operated full throttle, the cooling system is required to removed approximately 4000 Kcal/h. In order to achieve this, a flow rate of 167 liter/min (viz., 4000-60×1/4) must be produced by the water pump. This of course undesirably consumes a number of useful horsepower.
FIG. 2 shows an arrangement disclosed in Japanese Patent Application Second Provisional Publication Sho. No. 57-57608. This arrangement has attempted to vaporize a liquid coolant and use the gaseous form thereof as a vehicle for removing heat from the engine. In this system the radiator 1 and the coolant jacket 2 are in constant and free communication via conduits 3, 4 whereby the coolant which condenses in the radiator 1 is returned to the coolant jacket 2 little by little under the influence of gravity.
This arrangement while eliminating the need for the the power consuming circulation pump which plagues the above described arrangement, has suffered from the drawbacks that the radiator, depending on its position with respect to the engine proper, tends to be at least partially filled with liquid coolant. This greatly reduces the surface area via which the gaseous coolant (for example steam) can effectively release its latent heat of vaporization and accordingly condense, and thus has lacked any notable improvement in cooling efficiency.
Further, with this system in order to maintain the pressure within the coolant jacket and radiator at atmospheric level, a gas permeable water shedding filter 5 is arranged as shown, to permit the entry of air into and out of the system. However, this filter permits gaseous coolant to gradually escape from the system, inducing the need for frequent topping up of the coolant level.
A further problem with this arrangement has come in that some of the air, which is sucked into the cooling system as the engine cools, tends to dissolve in the water, whereby upon start up of the engine, the dissolved air tends to form small bubbles in the radiator which adhere to the walls thereof forming an insulating layer. The undissolved air also tends to collect in the upper section of the radiator and inhibit the convention-like circulation of the vapor from the cylinder block to the radiator. This of course further deteriorates the performance of the device.
European Patent Application Provisional Publication No. 0 059 423 published on Sept. 8, 1982 discloses another arrangement wherein, liquid coolant in the coolant jacket of the engine, is not forcefully circulated therein and permitted to absorb heat to the point of boiling. The gaseous coolant thus generated is adiabatically compressed in a compressor so as to raise the temperature and pressure thereof and thereafter introduced into a heat exchanger (radiator). After condensing, the coolant is temporarily stored in a reservoir and recycled back into the coolant jacket via a flow control valve.
This arrangement has suffered from the drawback that air tends to leak into the system upon cooling thereof. This air tends to be forced by the compressor along with the gaseous coolant into the radiator. Due to the difference in specific gravity, the air tends to rise in the hot environment while the coolant which has condensed moves downwardly. Accordingly, air, due to this inherent tendency to rise, forms pockets of air which cause a kind of `embolism` in the radiator and badly impair the heat exchange ability thereof.
U.S. Pat. No. 4,367,699 issued on Jan. 11, 1983 in the name of Evans (see FIG. 3 of the drawings) discloses an engine system wherein the coolant is boiled and the vapor used to remove heat from the engine. This arrangement features a separation tank 6 wherein gaseous and liquid coolant are initially separated. The liquid coolant is fed back to the cylinder block 7 under the influence of gravity while the `dry` gaseous coolant (steam for example) is condensed in a fan cooled radiator 8. The temperature of the radiator is controlled by selective energizations of the fan 9 to maintain a rate of condensation therein sufficient to maintain a liquid seal at the bottom of the device. Condensate discharged from the radiator via the above mentioned liquid seal is collected in a small reservoir-like arrangement 10 and pumped back up to the separation tank via a small constantly energized pump 11.
This arrangement, while providing an arrangement via which air can be initially purged to some degree from the system tends to, due to the nature of the arrangement which permits said initial non-condensible matter to be forced out of the system, suffer from rapid loss of coolant when operated at relatively high altitudes. Further, once the engine cools air is relatively freely admitted back into the system.
The provision of the separation tank 6 also renders engine layout difficult in that such a tank must be placed at relatively high position with respect to the engine, and contain a relatively large amount of coolant so as to buffer the fluctuations in coolant consumption in the coolant jacket. That is to say, as the pump 11 which lifts the coolant from the small reservoir arrangement located below the radiator, is constantly energized (apparently to obivate the need for level sensors and the like arrangement which could control the amount of coolant returned to the coolant jacket) the amount of coolant stored in the seperation tank must be sufficient as to allow for sudden variations in the amount of coolant consumed in the coolant jacket due to sudden changes in the amount of fuel combusted in the combustion chambers of the engine.
Japanese patent application First Provisional Publication sho. No. 56-32026 (see FIG. 4 of the drawings) discloses an arrangement wherein the structure defining the cylinder head and cylinder liners are covered in a porous layer of ceramic material 12 and coolant sprayed into the cylinder block from shower-like arrangements 13 located above the cylinder heads 14. The interior of the coolant jacket defined within the engine proper is essentially filled with only gaseous coolant during engine operation during which liquid coolant is sprayed onto the ceramic layers 12. However, this arrangement has proven totally unsatisfactory in that upon boiling of the liquid coolant absorbed into the eramic layers, the vapor thus produced and which escapes into the coolant jacket inhibits the penetration of fresh liquid coolant and induces the situation wherein rapid overheat and thermal damage of the ceramic layers 12 and/or engine soon results. Further, this arrangement is plagued with air contamination and blockages in the radiator similar to the compressor equipped arrangement discussed above.
FIG. 7 shows an arrangement which is disclosed in copending U.S. patent application Ser. No. 663,911 filed on Oct. 23, 1984 in the name of Hirano now U.S. Pat. No. 4,549,505. The disclosure of this application is hereby incorporated by reference thereto. For convenience the same numerals as used in the just mentioned application are also used in FIG. 7 so as to facilitate ready understanding of same.
However, this arrangement while overcoming many of the problems encountered by the prior art by (a) filling the cooling circuit defined by coolant jacket, radiator and interconnecting conduiting with coolant from an auxiliary reservoir when the engine is stopped and (b) performing non-condensible matter purges when the engine is subject to cold starts, has itself encountered the drawback that in order to execute the purge operation which is executed during cold engine starts, sufficient coolant must be stored in the reservoir 146 and requires valves and conduits which tend to clutter the already crowded environment of the modern automotive vehicle engine compartment. Hence, the system tends to be heavier and more complex than preferred.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an evaporative type cooling system for an automotive internal combustion engine or the like which is relatively simple in construction and which reduces the amount of reserve coolant which must be carried with the engine for the purposes of preventing the entry of non-condensible matter such as atmospheric air into the system when the engine is stopped and/or operating under conditions when sub-atmosperic conditions tend to prevail within the cooling circuit of the system.
In brief, the above object is achieved by an arrangement wherein in order to minimize the number of valves and conduits and the amount of coolant must be carried in an auxiliary reservoir of an evaporative type automotive cooling system, the valve and conduit arrangement which communicates the normally closed circuit cooling system with the resevoir consists of only two conduits and two valves. When the engine is stopped the cooling circuit is allowed to fill completely with the coolant from the reservoir. When the engine is started, a low temperature non-condensible matter purge operation is avoided and if the temperature rises above a target value, either coolant is pumped out of the system (if excess coolant is available therein) or high temperature vapor is vented from the bottom of the radiator in bursts to purge out the non-condensible matter.
More specifically, a first aspect of the present invention takes the form of an internal combustion engine having a structure subject to high heat flux and a cooling system which is characterized by: (a) a cooling circuit for removing heat from the structure, the cooling circuit comprising: a coolant jacket disposed about the structure and into which coolant is introduced in liquid form and permitted to boil; radiator in which coolant vapor is condensed to its liquid form; a vapor transfer conduit leading from a vapor collection space defined in the coolant jacket to the radiator; means for returning liquid coolant from the radiator to the coolant jacket in a manner which maintains the structure immersed in a predetermined depth of liquid coolant, the liquid coolant returning means including: a coolant return conduit leading from the bottom of the radiator to the coolant jacket, and a pump disposed in the coolant return conduit, the pump being selectively energizable to return coolant from the radiator to the coolant jacket through the coolant return conduit; (b) a reservoir in which liquid coolant is stored; and (c) valve and conduit means for selectively providing fluid communication between the reservoir and the cooling circuit, the valve and conduit means consisting of: a first valve disposed in the coolant return conduit at a location between the pump and the coolant jacket, the first valve having a first position wherein communication between the pump and the coolant jacket is established and a second position wherein communication between the reservoir and the pump is established via a level control conduit which leads from the reservoir to the first valve, the pump being reversible so as to enable coolant to be pumped into or out of the coolant circuit when the first valve is in the second position; a fill/discharge conduit which leads from the reservoir to the bottom of the radiator; and a second valve disposed in the fill/discharge conduit; the second valve having a first position wherein communication between the reservoir and the radiator is cut-off and a second position wherein communication is permitted.
A further aspect of the present invention comes in a method of cooling an internal combustion engine having a structure subject to high heat flux comprising the steps of: introducing liquid coolant into a coolant jacket disposed about the structure; permitting the coolant to boil and produce coolant vapor; condensing the coolant vapor produced in the coolant jacket to its liquid form in a radiator; using a pump to return the liquid coolant from the radiator to the coolant jacket in a manner which maintains the structure immersed in a predetermined depth of coolant; storing liquid coolant in a reservoir; controlling the communication between the reservoir and a cooling circuit including the coolant jacket and the radiator using a first conduit which leads from the reservoir to the cooling circuit at a location between the pump and the coolant jacket; a first valve which selectively provides communication between the pump and the reservoir via the first conduit and communication between the pump and the coolant jacket; a second conduit which leads from the bottom of the radiator to the reservoir; and a second valve which selectively provides and cuts-off fluid commuication between the radiator and the reservoir via the second conduit; permitting coolant from the reservoir to be inducted into the coolant jacket and radiator when the engine is stopped and below a predetermined temperature; displacing coolant from the coolant jacket and radiator to the reservoir via the second conduit when the engine is started and warming up; and controlling the temperature and pressure in the coolant jacket and radiator by: (i) increasing the exchange of heat between the radiator and a cooling medium surrounding same, (ii) pumping coolant into and out of the radiator and coolant jacket using the pump; and (iii) venting coolant vapor from the radiator via the second conduit when the temperature of the coolant in the coolant jacket rises above a maximum permissible level.
BRIEF DESCRIPTION OF THE DRAWINGS
The features and advantages of the arrangement of the present invention will become more clearly appreciated from the following description taken in conjunction with the following drawings in which:
FIGS. 1 to 4 show the prior art arrangements discussed in the opening paragraphs of the instant disclosure;
FIG. 5 is a graph showing in terms of induction vacuum (load) and engine speed the various load zones encountered by an automotive internal combustion engine;
FIG. 6 is a graph showing in terms of pressure and temperature, the change which occurs in the coolant boiling point with change in pressure;
FIG. 7 shows in schematic elevation the arrangement disclosed in the opening paragraphs of the instant disclosure in conjunction with copending U.S. patent application Ser. No. 663,911;
FIG. 8 shows an embodiment of the present invention; and
FIGS. 9 to 13 show flow charts which depict the operations which characterize the control of the arrangement shown in FIG. 8.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Before proceeding with the description of the embodiments of the present invention, it is deemed appropriate to discuss some of the features of the type of cooling system to which the present invention is directed.
FIG. 5 graphically shows in terms of engine torque and engine speed the various load `zones` which are encountered by an automotive vehicle engine. In this graph, the curve F denotes full throttle torque characteristics, trace L denote the resistance encountered when a vehicle is running on a level surface, and zones I, II and III denote respectively `urban cruising`, `high speed cruising` and `high load operation` (such as hillclimbing, towing etc.).
A suitable coolant temperature for zone I is approximately 110° C. while 90°-80° C. for zones II and III. The high temperature during `urban cruising` promotes improved thermal efficiency while simultaneously removing sufficient heat from the engine and associated structure to prevent engine knocking and/or engine damage in the other zones. For operational modes which fall between the aforementioned first, second and third zones, it is possible to maintain the engine coolant temperature at approximately 100° C.
With the present invention, in order to control the temperature of the engine, advantage is taken of the fact that with a cooling system wherein the coolant is boiled and the vapor used a heat transfer medium, the amount of coolant actually circulated between the coolant jacket and the radiator is very small, the amount of heat removed from the engine per unit volume of coolant is very high, and upon boiling, the pressure prevailing within the coolant jacket and consequently the boiling point of the coolant rises if the system employed is closed. Thus, by circulating only a limited amount of cooling air over the radiator, it is possible reduce the rate of condensation therein and cause the pressure within the cooling system to rise above atmospheric and thus induce the situation, as shown in FIG. 7, wherein the engine coolant boils at temperatures above 100° C. for example as high as approximately 119° C. (corresponding to a pressure of approximately 1.9 Atmospheres).
On the other hand, during high speed cruising, it is further possible by increasing the flow cooling air passing over the radiator, to increase the rate of condensation within the radiator to a level which reduces the pressure prevailing in the cooling system below atmospheric and thus induce the situation wherein the coolant boils at temperatures in the order of 80° to 90° C. However, under such conditions the tendency for air to find its way into the interior of the cooling circuit becomes excessively high and it is desirable under these circumstances to limit the degree to which a negative pressure is permitted to develop. This can be achieved by permitting coolant to be introduced into the cooling circuit from the reservoir and thus raise the pressure in the system to a suitable level.
FIG. 8 shows an embodiment of the present invention. In this arrangement an engine 200 includes a cylinder block 202 on which a cylinder head 204 is detachably mounted. The cylinder block and cylinder head are formed with cavities which define a coolant jacket 206 about the heated structure of the engine.
A vapor manifold 208 is detachably mounted on the cylinder head 204 and arranged to communicate with a condensor or radiator (as it will be referred to hereinafter) 210 via a vapor transfer conduit 212.
In this embodiment the radiator 210 comprises a plurality of relatively small diameter conduits which terminate in a small collection vessel or lower tank 214. A coolant return conduit 216 leads from the lower tank 214 to the coolant jacket 206. In this embodiment the return conduit 216 communicates with the cylinder head 204 at a location proximate the most highly heated structure of the engine 200. This arrangement introduces the relatively cool coolant into a section of the coolant jacket 206 where the most vigorous boiling tends to occur and therefore tends to attenuate the bumping and frothing which normally accompanies same. However, it is also within the scope of the present invention to connect the return conduit 216 to a port formed in the section of the coolant jacket 206 defined within the cylinder block 202 if so desired.
A small capacity coolant reversible return pump 218 is disposed in conduit 216 as shown. This pump is aranged to be selectively energizable to pump coolant from said lower tank 214 toward the coolant jacket 206 (viz., a first flow direction) and in the reverse direction (second flow direction). The reason for this arrangement will become clear hereinlater.
In order to control the operation of pump 218 (in the first flow direction) a first level sensor 220 is disposed in the coolant jacket. As shown, this level sensor 220 is arranged at a level H1 which is selected to be a predetermined height above the structure which defines the cylinder heads, exhaust ports and valves of the engine (viz., structure subject to a high heat flux) so as to maintain same immersed in sufficient coolant and thus obviate the formation of localized dryouts (induced by excessively violent bumping and frothing of the coolant) and thus avoid engine damage due to localized overheating and the like. This sensor may be arranged to exhibit hysteresis characteristics so as to prevent rapid ON/OFF cycling of pump 218.
Disposed below the level sensor 220 so as to be securely immersed in liquid coolant and in relatively close proximity to the most highly heated structure of the engine is a temperature sensor 222.
A reservoir 224, the interior of which is maintained constantly at atmospheric pressure, is arranged to fluidly communicate with what shall be referred to as a `cooling circuit` (viz., a circuit comprised of the coolant jacket 206, the vapor manifold 208, the vapor transfer conduit 212 and coolant return conduit 216) via a `valve and conduit` arrangement. In this embodiment the valve and conduit arrangement comprises a three-way valve 232 disposed in the coolant return conduit 216 and which is arranged to have a first position wherein communication between the pump 218 and the reservoir 224 is established via an level control conduit 234 which leads from the reservoir to three-way valve 232 (viz., establish flow path A) and a second position wherein communication between the pump 216 and the coolant jacket 206 established (flow path B); a fill/displacement conduit 240 which leads from the reservoir 224 to the lower tank 214; and an ON/OFF valve 242 which is disposed in conduit 240 and which permits communication between the lower tank 214 and the reservoir 224 when de-energized and which cuts-off said communication upon energization.
In order to sense the pressure prevailing in the cooling circuit a pressure differential responsive switch arrangement 246 is arranged to communication with a riser section 247 formed in the vapor manifold 208. This device is set so as to issue a signal upon the pressure in the cooling circuit dropping by a predetermined small amount below atmospheric.
A small electric fan 248 or like device is disposed beside the radiator 210 and arranged to force a draft of air over the surface thereof and thus induce an increase in the heat exchange between the radiator and the surrounding atmospheric air.
A control cirucit 250 which in this embodiment includes a microprocessor comprising a CPU, a RAM a ROM and an in/out interface I/O, is arranged to receive inputs from temperature sensor 222 and level sensor 220. This circuit also receives data inputs from an engine speed sensor 252, a engine load sensor 254 and a second level sensor 256 disposed in lower tank 214 at a level essentially equal to that at which the fill/discharge conduit 240 communicates with same.
The ROM of the microprocessor contains various control programs which are used to control the operation of the fan, pump and valves, and of the valve and conduit arrangement. These programs will be discussed in some detail hereinlater.
Prior being put into use it is necessary to completely fill the cooling circuit with coolant and displace any non-condensible matter. To do this it is possible to remove the cap 258 which closes the riser 247 and manually fill the system with liquid coolant (for example water or a mixture of water and anti-freeze). Alternatively, or in combination with the above, it is possible to introduce excess coolant into reservoir 224, condition valve 232 to produce flow path A and energize pump 218 to pump in the second flow direction until such time as coolant may be visibly seen spilling out of the open riser 228. By securing the cap in place at this time it is possible to hermetically seal the system in a completely filled condition.
SYSTEM CONTROL ROUTINE
FIG. 9 shows in flow chart form a control routine which manages the overall operation of the cooling system shown in FIG. 8. As shown, subsequent to start of the engine and initialization of the system, at step 1001 the valves of the system are conditioned so that valve 232 establishes flow path B while valve 242 is closed. It should be noted that throughout the discussion of the flow charts of FIGS. 9 to 13 a convention wherein valve 232 will be referred to as valve I and valve 242 to as valve II will be adopted for simplicity.
At step 1003 a coolant jacket (C/J) level control routine is implemented. Following this at step 1004 the temperature of the coolant is determined by sampling the output of temperature sensor 222. In the event that the temperature of the coolant is below 80° C. then the program flows to step 1005 wherein valve II is opened to render the system open circuit and thus permit coolant to be inducted to displaced from the lower tank 214 in accordance with the pressure differential which exists between the interior of the radiator and the ambient atmosphere. Following step 1005 the program recycles to step 1004. However, if the temperature of the coolant is found to be between 80° C. and a value equal to Target+α1 (wherein the Target temperature is a temperature determined in view of the instant set of engine operating conditions and a1 is equal to 2° C. - note that the nature and method of deriving the target temperature will be discussed in some detail in connection with the flow chart shown in FIG. 13 hereinlater) then the program goes to step 1006 wherein an order to close valve II is issued. On the other hand, if the instant coolant temperature is found to be above target+α1 then valve II is closed in step 1007 so as to hermetically seal the system into a closed state and thus prevent the situation wherein coolant and or coolant vapor can be undesirably forced out of the system by superatmospheric pressures. Following this, the output of level sensor 256 is sampled and in the event that the coolant in the lower tank is not above level H2 then the program flows to step 1009 wherein commands to stop the operation of the coolant return pump 218 and to condition valve I to produce flow path B are issued. Following this an abnormally high temperature control routine is run in step 1010. However, if the enquiry carried out in step 1008 reveals that the coolant level in lower tank 214 is in fact below level H2 then at step 1011 the coolant jacket level control program is run again. Following this, at step 1012 commands are issued to establish flow path A and to energize pump 218 in the first flow direction (viz., condition the system to pump coolant from the lower tank 214 to the reservoir 224.)
At step 1013 the temperature of the coolant is determined by sampling the output of temperature sensor 222 and ranged in a manner wherein if the temperature is above target+α1 then the program recycles to step 1008 while if less than said value, at step 1014 the operation of pump 218 is stopped and valve I condition to produce flow path B. At step 1015 a command to stop the operation of fan 248 is issued and the program recycles to step 1003.
As will be appreciated while the temperature of the coolant is low (viz., below 80° C.) the system is held in an open state. However, upon the temperature of the coolant entering an acceptable range the program will recycle between steps 1004 and 1003 until such time as the goes above an upper limit which varies with operational conditions of the engine. Thus, in cold climates wherein the heat exchange efficiency the radiator need not be particlularly high by way of example), as soon as the temperture of the coolant enters the above mentioned acceptable range the system will be placed in a closed state even if the radiator is still partially filled with liquid coolant. This state will be maintained until such time as the inclusion of atmsopheric air or the like induces the situation wherein the temperature exceeds the optimal temperature by 2° C. Under such conditions the level of coolant in the lower tank 214 is determined. If excess coolant is found to be still contained in the radiator 210 steps are implemented to firstly maintain the coolant jacket level at H1 then pump an amount of coolant out to the reservoir 224. However, if the coolant level in the radiator 210 has been lowered to the minimum level (viz., H2) then it is deemed that air rather than excess coolant is the cause of the elevated temperautres and accordingly a suitable control routine is entered. Until such time as the temperature of the coolant drops sufficiently the program recycles from step 1013 to 1008 so as to repeat either the coolant displacement procedure or the `hot purge` venting of non-condensible matter which characterizes the routine of step 1009.
COOLANT JACKET LEVEL CONTROL ROUTINE
FIG. 10 shows in flow chart form the steps which characterize the coolant jacket level conrol routine.
As shown, the first step of this routine is such as to sample the output of level sensor 220 and determine if the level of coolant is below H1 or not. In the event that the level of coolant is above level H1 then at steps 2002 and 2003 a commmand to stop the operation of pump 218 is issued and a soft clock or `time 1` is cleared and the program returns. On the other hand if the level of coolant in the coolant jacket is found to be insufficient (viz., below level H1) then the program goes to step 2004 wherein a command to stop the operation of the pump is issued. This step clears the pump control and ensures that the pump will not be energized in the wrong direction at step 2005. At step 2006 the soft clock or `timer 1` is set counting for a period of ten seconds. In the event that the level of coolant in the coolant jacket comes up to H1 within this period then the program is switched at step 2001 and the program returns via steps 2002 and 2003. However, if the pump should be maintained on for the full count (10 seconds) then at step 2007 timer 1 is reset and at step 2008 a commands to stop the operation of pump 218 and condition valve 232 to establish flow path A are issued. Subsequently, at step 2009 pump 218 is energized to pump in the second flow direction and thus pump coolant from the reservoir 224 to the lower tank. This condition is maintained for a period of 5 seconds (see steps 2010 and 2011). Following this valve 232 is induced to switch back to flow path B and the program recycles. As will be appreciated steps 2008 to 2012 are such as to pump a little additional coolant into the system and thus slightly increase the total amount of coolant therein. This in combination with the control induced at steps 1012 and 1013 tends to hunt the amount of coolant toward exactly the desired level.
ABNORMALLY HIGH TEMPERATURE CONTROL ROUTINE
FIG. 11 shows the steps which characterize the abnormally high temperature control routine. As shown, at step 3001 the temperature of the coolant is determined and if within a rage of target+α2 to 115° C. then at step commands to energize fan 248 and close valve II are issued. Following this at step 3003 a soft clock `timer 3` is cleared in readiness for hot purge control. However, if the temperature determined in step 3001 is found to be lower than target+α2 then at steps 3004 and 3005 commands to stop the operation of fan 248 and open valve II are issued and timer 3 cleared. On the other hand, if the temperature is determined to be above a maximum permissible limit (in this case 115° C.) then at step 3006 fan 248 is energized, at step 3007 the coolant jacket level control routine is run and at step 3008 valve II is conditioned to assume and open condition and thus permit coolant vapor to vent out of the radiator 210 via conduit 240 and thus perform what is is referred to in this specification as a `hot purge`. As will be appreciated. As conduit 240 communicates with lower tank 224 at essentially the same level as sensor 256, this venting will tend to discharge little or no liquid coolant as the coolant level under such high temperature conditions will invariably be at H2. Further, the sudden momentary switch to open circuit status allows the pressurized coolant vapor to flow rapidly down through the radiator 210 carrying any traces of air (or the like) along therewith. Several runs of this program is usually sufficient to rid the system of any non-condensible matter and bring the temperature rapidly back into a desirable range.
Following step 3008 timer 3 is set counting (step 3009). In this embodiment counter 3 is arranged to count over a period of 60 seconds. In the event that the overheat condition is not controlled within this period then at step 3010 a warning is issued indicating that normal control measures have not proven effective and a prolonged overheat condition has been detected whereby the engine should be stopped and the cooling system inspected for apparatus malfuction.
INTERRUPT ROUTINE
FIG. 12 shows an interrupt routine which is run at frequent intervals to determine the status of the engine and if it is necessary to implement a shutdown control routine which controls the cooling of the engine after the engine is stopped in a manner which obivates the loss of coolant and/or the induction of large amount of atmospheric air.
SHUT-DOWN CONTROL ROUTINE
The first step (5001) of this routine is such as to evacuate the current fan ON/OFF control data from the CPU and thus clear the way for a new set of control conditions. At step 5002 the status of the ignition switch is determined so as ascertain if the engine has been stopped by the driver or is still running. In the event that the engine is still in use (viz., the ignition key is still ON) then the program goes to steps 5003 and 5004 wherein the value of the target temperature is determined and timers 4 and 5 are cleared. However, if the igntion key is OFF, then at step 5005 the instant coolant temperature is sampled. In the event that the temperature is below 80° C. then the program flows directly to step 5010 wherein the power to the entire system is cut-off. However, if the coolant temperature is still above the minimum permissible level then at step the target value is set to 80° C. and a timer 4 set counting in a manner which prevents the operation of the fan 248 from being stopped for a period of 10 seconds. At step 5009 an enquiry is performed to determine if the instant coolant temperature is below 97° C. and the pressure prevailing within the cooling circuit is sub-atmospheric. The latter mentioned parameter is determined by sampling the output of the pressure differential switch arrangement 246.
If both of the conditions are simultaneously met then the program flows to step 5010 wherein the power supply is terminated otherwise at step 5011 timer 5 is set and while the count of this timer remains within 60 seconds and the both of the requirements of step 5009 are not met then the program is forced to return. As the coolant is above the newly set target temperature (80° C.) the operation of the cooling fan 248 will be induced as at step 3002 of the high temperature control routine. | In order to minimize the number of valves and conduits and the amount of coolant must be carried in an auxiliary reservoir of an evaporative type automotive cooling system, the valve and conduit arrangement which communicates the normally closed circuit cooling system with the reservoir consists of only two conduits and two valves. When the engine is stopped the cooling circuit is allowed to fill completely with the coolant from the reservoir. When the engine is started a low temperature non-condensible matter purge operation is avoided and if the temperature rises above a target value, either coolant is pumped out of the system (if excess coolant is available therein) or high temperature vapor is vented from the bottom of the radiator in bursts to purge out the non-condensible matter. | 5 |
BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
From one aspect, the present invention relates to a universal joint of the kind, hereinafter called the kind specified, normally referred to as a Hooke's joint and comprising two yoke elements which in use rotate about respective axes (hereinafter called the rotatry axes) and a connecting member connected to each of the yoke elements for pivotal movement about respective axes (hereinafter called the pivot axes) which are mutually perpendicular, the pivot axis of each yoke element also being perpendicular to the rotary axis of that yoke element, each yoke element comprising a base portion and a pair of arms projecting from the base portion in a direction longitudinally of the rotary axis, each yoke arm being formed with an opening in which a respective trunnion of the connecting member is received and the joint further including retaining elements associated with respective yoke arms for controlling movement of the associated trunnion relative to the arm in a direction away from the rotary axis.
Joints of the kind specified generally also include bearing cups situated one within the opening of each yoke arm to receive the associated trunnion of the connecting member, each bearing cup containing a plurality of needle bearings interposed between the trunnion and the peripheral wall of the cup. A form of retaining element which has commonly been used is a circlip. When such a retaining element is used, an annular groove to receive the circlip must be machined in the yoke arm adjacent to the outer end of the opening therein. Such groove can be formed by a turning operation, but it is difficult to control the position of the groove within close tolerances. Furthermore, the tool used in the turning operation is necessarily small and is liable to break.
A further problem which arises in this known construction is that the most satisfactory position for the groove is not known exactly at the stage when the groove is formed in the yoke arm. It is desirable that no substantial clearance should exist between the components in the assembled joint. If such clearances exist, relative movement of the components can occur after the joint has been assembled and it will not be possible to ensure that the joint remains balanced about the rotary axes during use. Such imbalance as may occur gives rise to vibration of the joint in use which gives rise to undesirable noise and may lead to excessive wear of components of the joint or associated members. It is not possible to manufacture the components of the joint economically to within very close tolerances and therefore if the position of the groove is determined before the components of the joint are assembled, in at least some cases, there will be undesirable play between components of the joint.
A further form of retaining element which has been proposed has a plurality of arms which project radially from the centre of the retaining element. With this further form of retaining element, it is not necessary to preform a groove in the yoke arm. The retaining element is inserted into the opening of the yoke arm from the outer end thereof and is forced into engagement with an end wall of the bearing cup. The arms of the retaining element are so formed that they deflect as the retaining element is forced into the opening and tend to bite into the wall of the opening when the retaining element moves in a direction away from the rotary axis.
This further known construction has several disadvantages. If the joint is disassembled for servicing purposes, it is difficult or impossible to ensure that, upon reassembly of the joint, the retaining element is returned to its original position. If the retaining element is fitted in a new position, it is likely that the reassembled joint will be unbalanced. Although if the retaining element is urged outwardly of the opening in the yoke arm by the adjacent bearing cup, the arms of the retaining element will bite into the walls of the opening and thereby oppose such outward movement, movement of the retaining element in the outward direction is not completely prevented. The resistance to outward movement reaches a value sufficient to prevent further outward movement of the adjacent bearing cup and associated trunnion only when there has occurred sufficient outward movement to cause the arms to bite deeply into the walls, of the opening. Accordingly, this form of retaining element cannot prevent play between components of the joint. Furthermore, the shape of the indentations made in the wall of the opening by the arms of the retaining element is such that the boundary of each indentation remote from the rotary axis is inclined at an obtuse angle to the adjacent surface of the wall of the opening. Abutment of the retaining element against this inclined surface does not provide secure retention of the retaining element within the opening and there is a risk that the retaining element will fail to remain in position throughout the service life of the joint.
It is an object of the present invention to provide a joint of the kind specified and a method of assembling such joint which reduces or overcomes one or more of the foregoing disadvantages.
SUMMARY OF THE INVENTION
According to a first aspect of the invention we provide a method of making a joint of the kind specified wherein a groove for receiving portions of a retaining element is formed in the wall of the opening of an associated yoke arm by inserting the retaining element into the opening and turning the retaining element relative to the yoke arm about the pivot axis to cut the groove.
Preferably a bearing cup is inserted before the retaining element into the opening, the bearing cup is displaced relative to the yoke arm to the position which the bearing cup is required to occupy during use of the joint, the retaining element is engaged with an end wall of the bearing cup and remains so engaged whilst being turned to cut the groove.
The retaining element may be contracted, during or prior to insertion into the opening, elastically from its unstressed size and, whilst being turned, be permitted to expand radially of the pivot axis towards its unstressed size.
According to a second aspect of the invention, we provide a joint of the kind specified wherein the wall of the opening in at least one of said yoke arms is formed with an annular groove and the retaining element associated with said yoke arm includes a plurality of fingers projecting radially of the pivot axis, a free end portion of each finger being seated in the groove.
The groove would normally have been cut by the retaining element engaged therein, but if the joint is diassembled, for example for maintenance purposes, a new retaining element may be fitted into the groove without any further cutting.
Preferably, the retaining element is formed at the free end of one or more of the fingers with a cutting edge which is parallel to the pivot axis. With this arrangement cutting of the groove by rotation of the retaining element about the pivot axis without movement therealong will result in the formation of a groove of rectangular shape in cross-section, the boundaries of the groove being parallel to and perpendicular to the pivot axis respectively.
According to a third aspect of the invention we provide a retaining element for a joint of the kind specified, the retaining element comprising a mid-portion which includes the centre of the retaining element and a plurality of fingers projecting from the mid-portion and extending radially with respect to the centre, the retaining element having a dished shape such that free end portions of the fingers are substantially co-planar and the mid-portion is off-set from the plane of the free end portions, a cutting edge being provided on each of said free end portions at the periphery of the retaining element and such cutting edge being perpendicular to the plane of the free end portions.
According to a fourth aspect of the invention we provide, for use in performance of the method of the invention, a tool comprising a hollow outer member and an inner member disposed therein, the outer member having abutments near to but spaced from one end of the outer member, these abutments facing towards said one end, and a plurality of legs projecting from positions between successive ones of said abutments to said one end of the outer member, and the inner member having abutments near to a corresponding end of the inner member and facing away from said corresponding end.
In use, the abutments of the outer member would be engaged with one face of an outer part of the retaining element, the abutments of the inner part would be engaged with the opposite face of an inner part of the retaining element and the inner member would be displaced relative to the outer member to dish the retaining element, or increase the extent to which the retaining element is dished, thereby contracting the retaining element radially for insertion into the opening of the yoke arm.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described by way of example with reference to the accompanying drawings wherein:
FIG. 1 is a fragmentary view, partly in cross-section, of a joint of the kind specified,
FIG. 1a is a perspective view of a retaining element of the joint of FIG. 1,
FIG. 2 illustrates a method of assembly of the joint shown in FIG. 1 and shows, partly in cross-section, on the line A--A of FIG. 1, a portion of the joint and a tool used in assembly of the joint.
FIG. 3 is a perspective view of an inner part of the tool of FIG. 2, and
FIG. 4 is a fragmentary perspective view of an end portion of an outer part of the tool.
DETAILED DESCRIPTION
The joint illustrated in FIG. 1 comprises two yoke elements 10 and 11 respectively which in use rotate about respective rotary axes. In the straight position of the joint, which is illustrated in FIG. 1 these axes coincide and are indicated in FIG. 1 by reference numeral 12. Each yoke element includes a base portion 13 and a pair of arms 14 and 15 integral with the base portion and projecting therefrom in the axial direction.
A circular opening 16 is formed in each of the yoke arms adjacent to the free end thereof, the openings of the yoke element 10 being aligned with each other and the openings 16 of the yoke element 11 being aligned with each other. In each of the openings 16 there is received a bearing cup 17 which in turn receives a corresponding trunnion of a connecting member 18. The bearing cups contain needle bearings interposed between the trunnions and the peripheral walls of the cups, so that the connecting member is free to pivot relative to the yoke element 10 about a pivot axis 19 perpendicular to the rotary axis of the yoke element 10, and the yoke element 11 is free to pivot relative to the connecting member about a pivot axis 20 perpendicular to the pivot axis 19 and to the rotary axis of the yoke element 11.
The construction thus far described is conventional. It is also conventional to provide in the openings 16 of each yoke arm a retaining element for controlling movement of the associated bearing cup 17 and the trunnion contained therein in a direction along the pivot axis outwardly of the joint, the retaining elements collectively retaining the yoke elements, the bearing cups and the connecting member in assembled relation with one another.
In the particular example of joint shown in FIG. 1, identical retaining elements are provided in each of the four openings 16. Alternatively, it would be possible to provide a retaining element of the form illustrated in only one of the openings 16 of each of the yoke elements 10 and 11, and to provide a retaining element of conventional form, for example a circlip, in the other opening 16 of each of the yoke elements 10 and 11.
The retaining element 21 provided in the opening 16 of the yoke arm 14 of the yoke element 11 is formed from steel strip which can be hardened to a hardness considerably greater than that of the mild steel of which the yoke elements 10 and 11 are formed. The retaining element has a mid-portion 22 from which radiate four fingers 23 spaced apart by gaps 24. As shown in FIG. 1, the gaps 24 extend from the periphery of the retaining element rather more than half-way towards the centre.
The retaining element 21 is of dished shape, the mid-portion 22 and adjacent parts of the fingers 23 lying in a first plane and free end portions 25 of the fingers lying in a second plane off-set from the first plane. At the periphery of the retaining element, each of the free end portions 25 is formed with a pair of cutting edges 26 which are perpendicular to the plane of the mid-portion 22. The distance between diametrically opposite cutting edges 26 is a little greater than the diamter of the opening 16 in which the retaining element is to be received. After forming to this size and shape, the retaining element is hardened and tempered.
Prior to assembly of the components of the joint shown in FIG. 1, an annular groove 27 is formed in the opening 16 of the yoke arm 15 of each yoke element. The yoke elements 10 and 11, the intermediate member 18, the bearing cups 17 and the needle bearings are then assembled together. A retaining element 28, which may be identical with the retaining element 21, is then contracted radially, in the manner to be described hereinafter, is inserted into the opening 16 of the yoke arm 15 to a position in which the free end portions of the retaining element fingers are aligned with the groove 27. The retaining element is then permitted to expand so that the free end portions seat in the groove 27. It will be appreciated that contraction of the retaining element to a size such that it will pass into the opening 16 is within the elastic limit of the retaining element. Accordingly, the free end portions of the fingers will engage the groove 27 without application to the retaining element 28 of a force tending to expand same radially.
The intermediate member 18, the yoke element 10 and the bearing cups 17 associated therewith are then set to the required positions, such that there is no play between these components in a direction along the pivot axis 19. The retaining element 21, which has previously been contracted in the manner to be described to a size such that it can be inserted into the opening 16, is then inserted into the opening of the yoke arm 14 and is displaced into engagement with an end wall of the adjacent bearing cup 17. The retaining element is then permitted to expand radially and is turned about the axis 19 so that the cutting edges 26 cut an annular groove in the wall of the opening 16. It will be noted that although the free end portions 25 of the retaining element are engaged with the end wall of the bearing cup, the mid-portion 22 is spaced from this end wall. If required, pressure may be applied to the mid-portion 22 to urge the latter towards the adjacent bearing cup. Such pressure would tend to expand the retaining element and increase the pressure under which the cutting edges 26 engage with the yoke arm 14.
It will be noted that as the cutting edges 26 are parallel to the axis 19 and the retaining element 21 is turned about this axis without movment therealong, the groove cut in the wall of the opening 16 is of rectangular shape in cross-section, boundaries of the groove being parallel to and perpendicular to the pivot axis 19 respectively.
It will be noted that in the completed joint, the free end portions 25 of the retaining elements 21 and 22 engage with the outer surfaces of end walls of adjacent bearing cups 17 at positions immediately adjacent to the grooves formed in the walls of the openings 16. Furthermore, within these grooves, the free end portions engage shoulders which are perpendicular to the pivot axis 19 and face towards the rotary axis 12. Accordingly, the free end portions of the retaining element will not yield under pressure from the adjacent bearing cup to permit any displacement of such bearing cup in a direction along the pivot axis 19 away from the rotary axis 12. The retaining elements can be removed by applying to the mid-portion 22 a force in a direction away from the rotary axis 12. This will cause radial contraction of the retaining element and withdraw the free end portions from the grooves. However, as the mid-portion 22 is spaced from the end wall of the adjacent bearing cup, such force cannot be applied to the retaining element by the bearing cup itself.
The tool for contracting the retaining element 21 is illustrated in FIGS. 2, 3 and 4. The tool comprises an outer tubular member 29 and an inner tubular member 30 which is a sliding fit therein. At one end, the outer member 29 is formed with four short legs 31 which are spaced apart around the periphery of the outer member. Between the legs 31, the outer member presents towards the adjacent end abutment surfaces 31 which are spaced from the adjacent end of the outer member by a distance slightly less than the depth of the retaining element 21.
The inner member 30 of the tool is provided, at the end which corresponds to the end of the outer member 29 provided with the legs 31, with two diametrically opposed hook-like elements 33. These hook-like elements are integral with respective legs 34 of the inner member which are long, as compared with the legs 31 of the outer member. The free ends of the hooks 33 face each other across a longitudinal axis of the tool and the hook-like elements present respective abutment faces 35 which face in a direction along the longitudinal axis of the tool and away from the adjacent end of the inner member.
The tool further comprises screw means for acting between the inner and outer members to draw the inner member in a direction away from the legs 31 of the outer member. This screw means is in the form of a bolt, whereof the head 36 overlies an end face of the outer member 29 remote from the legs 31. A shank 37 of the bolt is in threaded engagement with the inner member 30 which is keyed against rotation relative to the outer member. The outer member is formed with flats which can be engaged by a spanner and accordingly the bolt 36 can be turned relative to the tubular members 29 and 30 to draw the inner tubular member towards the bolt head 36.
The tool is used by inserting the hook-like elements 33 through a pair of diametrically-opposite gaps 24 in the retaining element 21 and engaging the abutment faces 35 of the tool with that face of the mid-portion 22 of the retaining element which faces towards the rotary axis 12 in the assembled joint. The legs 31 of the outer member are received in the gaps 24 between the fingers of the retaining element, thereby keying the retaining element to the outer member for rotation therewith. The bolt head 36 is then turned to draw the inner member 30 in a direction away from the legs 31 and the retaining element is thereby drawn into engagement with the abutment faces 32 of the outer member. Continued rotation of the bolt head 36 dishes the retaining element more strongly, as shown in FIG. 2, thereby contracting it radially.
When the retaining element has been contracted to a size such that it can pass into the opening 16, the retaining element is so inserted and engaged with the adjacent bearing cup 17. The bolt head 36 is then rotated in the reverse direction to permit the retaining element to expand and the outer member 29 is subsequently turned about the pivot axis 19 to turn the retaining element relative to the yoke arm 14 and cut the groove therein. | A Hooke's joint comprises four bearing cups received in openings in respective yoke arms and retained therein by respective retaining elements. At least one retaining element associated with each yoke has radially-projecting fingers which terminate in cutting edges and which are seated in a groove cut in the wall of the corresponding opening by rotation of the retaining element. There is also described a tool for contracting the retaining element to enable it to be inserted into the opening and for rotating the retaining element. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the use of tenidap and the pharmaceutically-acceptable base salts thereof for inhibiting the release of elastase by neutrophils in a mammal. Tenidap and its salts are useful for inhibiting the release of elastase by neutrophils in a mammal, per se, and in treating elastase-mediated diseases and dysfunctions in a mammal. Such elastase-mediated diseases and dysfunctions include, but are not limited to, arteritis, proteinuria and pulmonary emphysema. The use of tenidap and its salts comprises administering an effective amount thereof to a mammal.
2. General Background
Tenidap, 5-chloro-2,3-dihydro-2-oxo-3-(2-thienylcarbonyl)-indole-1-carboxamide, has the structural formula ##STR1## Tenidap, among other 3-substituted-2-oxindole-1-carboxamides are disclosed and claimed in U.S. Pat. No. 4,556,672 which is assigned to the assignee hereof. That patent discloses that those compounds, in addition to being useful as antiinflammatory and analgesic agents, are inhibitors of both cyclooxygenase (CO) and lipoxygenase (LO). The teachings thereof are incorporated herein by reference.
The use of tenidap and its pharmaceutically-accceptable base salts, among certain other 3-substituted-2-oxindole-1-carboxamides, to inhibit interleukin-1 biosynthesis in a mammal and to treat interleukin-1 mediated disorders and dysfunctions is disclosed in U.S. Pat. No. 4,861,794 which is assigned to the assignee hereof.
U.S. Pat. No. 4,853,409, assigned to the assignee hereof, discloses the use of tenidap and its pharmaceutically-acceptable base salts, among certain other 3-substituted-2-oxindole-1-carboxamides, to suppress T-cell function in a mammal and to treat T-cell mediated autoimmune disorders of the systemic or organ specific type.
An anhydrous, crystalline form of the sodium salt of tenidap is disclosed in European Patent Application 277,738, which has been filed in the name of the assignee hereof.
Elastase is a protease which is released by neutrophils in a mammal and mediates certain diseases and dysfunctions. [Janoff, A., American Journal of Pathology 68:579-591 (1972).] Such elastase mediated diseases and dysfunctions include, but are not limited to, arteritis, proteinuria and pulmonary emphysema [Janoff, A., Op. cit. and Johnson, R. J., et al., J. Exp. Med. 168:1169-1174 (1988).]
Until the invention herein, there was no report of use or intent to use tenidap or its salts to inhibit release of elastase by neutrophils in a mammal and to treat elastase-mediated diseases and dysfunctions with such compounds nor any appreciation of their role in such treatments.
SUMMARY OF THE INVENTION
It has been found that tenidap and the pharmaceutically-acceptable base salts thereof inhibit the release of elastase by neutrophils and are useful in inhibiting the release of elastase by neutrophils in a mammal, per se, and in treating elastase-mediated diseases and dysfunctions. Such elastase-mediated diseases and dysfunctions include, but are not limited to, arteritis, proteinuria and pulmonary emphysema.
The methods of using tenidap and its pharmaceutically-acceptable base salts comprise administering to a mammal an effective amount thereof. Administration can comprise any known method for therapeutically providing a compound to a mammal such as by oral or parenteral administration as defined hereinbelow.
DETAILED DESCRIPTION OF THE INVENTION
Tenidap, which has the chemical structure ##STR2## its pharmaceutically-acceptable base salts and the preparation thereof are described in U.S. Pat. No. 4,556,672, the teachings of which are incorporated herein by reference. This invention concerns new uses for tenidap and its salts which comprise methods for inhibiting the release of elastase by neutrophils in a mammal in need thereof. Also within the scope of this invention are methods of treating elastase-mediated disorders and dysfunctions in a mammal which include, but are not limited to, arteritis, proteinuria and pulmonary emphysema.
As disclosed in U.S. Pat. No. 4,556,672, tenidap is acidic and forms base salts. All such base salts are within the scope of this invention and can be formed as taught by that patent. Such suitable salts, within the scope of this invention, include both the organic and inorganic types and include, but are not limited to, the salts formed with ammonia, organic amines, alkali metal hydroxides, alkali metal carbonates, alkali metal bicarbonates, alkali metal hydrides, alkali metal alkoxides, alkaline earth metal hydroxides, alkaline earth metal carbonates, alkaline earth metal hydrides and alkaline earth metal alkoxides. Representative examples of bases which form such base salts include ammonia, primary amines, such as n-propylamine, n-butylamine, aniline, cyclohexylamine, benzylamine, p-toluidine, ethanolamine and glucamine; secondary amines, such as diethylamine, diethanolamine, N-methylglucamine, N-methylaniline, morpholine, pyrrolidine and piperidine; tertiary amines, such as triethylamine, triethanolamine, N,N-dimethylaniline, N-ethylpiperidine and N-methylmorpholine; hydroxides, such as sodium hydroxide; alkoxides such as sodium ethoxide and potassium methoxide; hydrides such as calcium hydride and sodium hydride; and carbonates such as potassium carbonate and sodium carbonate. Preferred salts are those of sodium, potassium, ammonium, ethanolamine, diethanolamine and triethanolamine. Particularly preferred is the sodium salt. European Patent Application 277,738, which has been filed in the name of the assignee hereof, discloses an anhydrous, crystalline form of such a salt. The teachings thereof are incorporated herein by reference.
Also within the scope of this invention are the solvates such as the hemihydrates and monohydrates of the compounds hereinabove described.
The methods of this invention comprise administering tenidap and the pharmaceutically-acceptable base salts thereof to a mammal. Such compounds and their salts can be administered to said mammal either alone or, preferably, in combination with pharmaceutically-acceptable carriers or diluents in a pharmaceutical composition, according to standard pharmaceutical practice. Such administration can be oral or parenteral. Parenteral administration as used herein includes, but is not limited to, intravenous, intramuscular, intraperitoneal, subcutaneous, transdermal and topical including, but not limited to oral lavage and inhalation, administration. While it is generally preferred to administer such compounds and their salts orally, other methods may be preferred depending upon the particular elastase-mediated disease or dysfunction being treated.
In general, tenidap and its salts are most desirably administered in doses ranging from about 20 mg up to about 200 mg per day, with a preferred range of about 40 mg up to about 120 mg per day, for oral administration and from about 1 mg up to about 200 mg per day for parenteral administration, although variations will still necessarily occur depending upon the weight of the subject being treated. The appropriate dose for inhibiting the release of elastase by neutrophils in a mammal and for treatment of elastase-mediated disorders and dysfunctions with tenidap and its salts will be readily determined by those skilled in the art of prescribing and/or administering such compounds. Nevertheless, it is still to be appreciated that other variations may also occur in this respect, depending upon the species of mammal being treated and its individual response to said medicament, as well as on the particular type of pharmaceutical formulation chosen and the time period and interval at which such administration is carried out. In some instances, dosage levels below the lower limit of the aforesaid range may be more than adequate, while in other cases still larger doses may be employed without causing any harmful or deleterious side effects to occur, provided that such higher dose levels are first divided into several smaller doses that are to be administered throughout the day.
For purposes of oral administration, tablets containing excipients such as sodium citrate, calcium carbonate and dicalcium phosphate may be employed along with various disintegrants such as starch and preferably potato or tapioca starch, alginic acid and certain complex silicates, together with binding agents such as polyvinylpyrrolidone, sucrose, gelatin and acacia. Additionally, lubricating agents such as, but not limited to, magnesium stearate, sodium lauryl sulfate and talc are often very useful for tableting purposes. Solid compositions of a similar type may also be employed as fillers in soft elastic and hard-filled gelatin capsules; preferred materials in this connection also include, by way of example and not of limitation, lactose or milk sugar as well as high molecular weight polyethylene glycols. When aqueous suspensions and/or elixirs are desired for oral administration, the essential active ingredient may be combined with various sweetening or flavoring agents, coloring matter or dyes and, if so desired, emulsifying and/or suspending agents, together with diluents such as water, ethanol, propylene glycol, glycerin and various like combinations thereof.
Although the generally preferred mode of administration of tenidap or its pharmaceutically-acceptable base salts is oral, they may be administered parenterally as well. Such parenteral administration may be the preferred mode of administration for the treatment of certain elastase-mediated diseases or dysfunctions.
For purposes of parenteral administration, solutions of tenidap or a salt thereof in sesame or peanut oil or in aqueous propylene glycol may be employed, as well as sterile aqueous solutions of the corresponding water soluble base salts previously enumerated. Such aqueous solutions should be suitably buffered if necessary, and the liquid diluent rendered isotonic with sufficient saline or glucose. These particular aqueous solutions are especially suitable for intravenous, intramuscular and subcutaneous injection purposes. In this connection, the sterile aqueous media employed are readily obtained by standard techniques well known to those skilled in the art. For instance, distilled water is ordinarily used as the liquid diluent and the final preparation is passed through a suitable bacterial filter such as a sintered glass filter or a diatomaceous-earth or unglazed porcelain filter. Preferred filters of this type include the Berkefeld, the Chamberland and the Asbestos Disk-Metal Seitz filter, wherein the fluid is sucked into a sterile container with the aid of a suction pump. The necessary steps should be taken throughout the preparation of these injectable solutions to insure that the final products are obtained in a sterile condition. For purposes of transdermal administration, the dosage form of the particular compound may include, by way of example, solutions, lotions, ointments, creams, gels, suppositories, rate-limiting sustained release formulations and devices therefor. Such dosage forms comprise the particular compound and may include ethanol, water, penetration enhancer and inert carriers such as gel-producing materials, mineral oil, emulsifying agents, benzyl alcohol and the like. Specific transdermal flux enhancing compositions are disclosed in European Patent Application 271,983 and European Patent Application 331,382, which have been filed in the name of the assignee of this invention, the teachings of which are incorporated herein by reference. For purposes of topical administration, the dosage form of the particular compound may include, by way of example and not of limitation, solutions, lotions, ointments, creams and gels. Further, administration by inhalation can be achieved by menas and methods well known to those skilled in the art. Such means include the use of nebulizers or atomizers whereby a solution of tenidap or a salt thereof is inhaled as a mist.
The ability of the compounds of this invention to inhibit the release of elastase by neutrophils was demonstrated by the assay procedure described in Dunn, T. L., et al., Analytical Biochemistry 150:18-24 (1985) and references cited therein. Neutrophils for the assay were obtain as follows. Whole human blood from normal volunteers was obtained by venipuncture into heparinized syringes. The majority of the red cells were removed by dextran sedimentation and neutrophils were separated by density centrifugation over hypaque ficoll. The neutrophil rich fraction was washed and residual red cells were removed by hypotonic lysis according to the procedure described by Blackburn, W. D. et al., Arthritis Rheum. 30:1006-1014 (1987). The neutrophils so prepared were used in the assay described below and cell viability was assured by determining their ability to exclude typan blue. In each assay the cell viability routinely exceeded 95%.
Affinity purified anti-human neutrophil elastase (anti-HNE) antibody was labeled with carrier free 125 I-Na by using a modification of the lactoperoxidase method of Marchelonis, J. J., Biochem. J. 113:229-305 (1969). Generally, 10 μg quantities of protein were labeled to an initial specific activity of 2.2×10 -5 mCi/ng. Free iodine was separated from bound 125 I by Sephadex G-25 column chromatography. The 125 I-labeled anti-HNE was aliquoted and stored at -70° C. for up to one month prior to use.
Neutrophil cell suspensions, prepared as described above, were incubated at 37° C. for 15-30 minutes in the presence of varying concentrations of tenidap. Tenidap was dissolved and diluted in water and added to the cells directly therefrom. After the cells had been incubated in the presence of tenidap, the cell suspensions (5×10 6 cells/ml, 125 μl well) were added to IgG coated and bovine serum albumin (BSA) blocked wells of microtiter plates and incubated for 45 minutes at 37° C. As controls, similar incubations were performed in the absence of IgG. Following incubation, the cell suspensions were centrifuged (750×g) for 5 minutes at 4° C.
DE-52 cellulose-purified IgG fraction goat anti-HNE (10 mg/ml), diluted at 1/1000 in PBS, was used to coat vinyl assay wells (125 μl ) for 4 hours at 25° C. The wells were then blocked with PBS-1% BSA (100 μl ) for 1 hour at 25° C. to eliminate nonspecific binding, washed with PBS three times and 100 μl samples of the supernatants obtained as described above were then added to each well and allowed to incubate 16 hours at 25° C. Standard curves were generated with serial dilutions of the DFP inactivated enzyme (500 μg/ml) in PBS-1% BSA. After three washings with PBS, affinity purified 125 I-labeled anti-HNE was added to each well (100,000 cpm/100 μl ). The wells were incubated for 16 hours at 25° C. and washed three times with PBS and each well was counted for 1 minute in a gamma counter. 125 I-Anti-HNE (cpm bound)×10 -3 was plotted against protein concentration in nanograms per milliliter. Standard binding curves using other purified proteins instead of HNE were used as described above. | This invention relates to the use of tenidap, 5-chloro-2,3-dihydro-2-oxo-3-(2-thienylcarbonyl)-indole-1-carboxamide, and the pharmaceutically-acceptable base salts thereof to inhibit the release of elastase by neutrophils in a mammal. This invention also relates to the use of tenidap and its salts for treating elastase-mediated diseases and dysfunctions such as arteritis, proteinuria and pulmonary emphysema in mammals. The methods of this invention comprise administering an effective amount of tenidap or salts thereof to a mammal. | 8 |
[0001] This application is a divisional application of a pending U.S. patent application, Ser. No. 09/099,632, entitled MICROCHANNELED ACTIVE FLUID HEAT EXCHANGER, filed on Jun. 18, 1998.
FIELD OF THE INVENTION
[0002] The present invention relates to methods of manufacturing heat exchangers that include a microchanneled structured surface defining small discrete channels for active fluid flow as a heat transfer medium.
BACKGROUND
[0003] Heat flow is a form of energy transfer that occurs between parts of a system at different temperatures. Heat flows between a first media at one temperature and a second media at another temperature by way of one or more of three heat flow mechanisms: convection, conduction, and radiation. Heat transfer occurs by convection through the flow of a gas or a liquid, such as a part being cooled by circulation of a coolant around the part. Conduction, on the other hand, is the transfer of heat between non-moving parts of system, such as through the interior of solid bodies, liquids, and gases. The rate of heat transfer through a solid, liquid, or gas by conduction depends upon certain properties of the solid, liquid, or gas being thermally effected, including its thermal capacity, thermal conductivity, and the amount of temperature variation between different portions of the solid, liquid, or gas. In general, metals are good conductors of heat, while cork, paper, fiberglass, and asbestos are poor conductors of heat. Gases are also generally poor conductors due to their dilute nature.
[0004] Common examples of heat exchangers include burners on an electric stove and immersion heaters. In both applications, an electrically conductive coil is typically used that is subjected to an electric current. The resistance in the electric coil generates heat, which can then be transferred to a media to be thermally effected through either conduction or convention by bringing the media into close proximity or direct contact with the conductive coil. In this manner, liquids can be maintained at a high temperature or can be chilled, and food can be cooked for consumption.
[0005] Because of the favorable conductive and convective properties associated with many types of fluid media and the transportability of fluids (i.e. the ability to pump, for example, a fluid from one location to another), many heat exchangers utilize a moving fluid to promote heat transfer to or from an object or other fluid to be thermally affected. A common type of such a heat exchanger is one in which a heat transfer fluid is contained within and flows through a confined body, such as a tube. The transfer of heat is accomplished from the heat transfer fluid to the wall of the tube or other confinement surface of the body by convection, and through the confinement surface by conduction. Heat transfer to a media desired to be thermally affected can then occur through convection, as when the confinement surface is placed in contact with a moving media, such as another liquid or a gas that is to be thermally affected by the heat exchanger, or through conduction, such as when the confinement surface is placed in direct contact with the media or other object desired to be thermally affected. To effectively promote heat transfer, the confinement surface should be constructed of a material having favorable conductive properties, such as a metal.
[0006] Specific applications in which heat exchangers have been advantageously employed include the microelectronics industry and the medical industry. For example, heat exchangers are used in connection with microelectronic circuits to dissipate the concentrations of heat produced by integrated circuit chips, microelectronic packages, and other components or hybrids thereof. In such an application, cooled forced air or cooled forced liquid can be used to reduce the temperature of a heat sink located adjacent to the circuit device to be cooled. An example of a heat exchanger used within the medical field is a thermal blanket used to either warm or cool patients.
[0007] Fluid transport by a conduit or other device in a heat exchanger to effect heat transfer may be characterized based on the mechanism that causes flow within the conduit or device. Where fluid transport pertains to a nonspontaneous fluid flow regime where the fluid flow results, for the most part, from an external force applied to the device, such fluid transport is considered active. In active transport, fluid flow is maintained through a device by means of a potential imposed over the flow field. This potential results from a pressure differential or concentration gradient, such as can be created using a vacuum source or a pump. Regardless of the mechanism, in active fluid transport it is a potential that motivates fluid flow through a device. A catheter that is attached to a vacuum source to draw liquid through the device is a well-known example of an active fluid transport device.
[0008] On the other hand, where the fluid transport pertains to a spontaneous flow regime where the fluid movement stems from a property inherent to the transport device, the fluid transport is considered passive. An example of spontaneous fluid transport is a sponge absorbing water. In the case of a sponge, it is the capillary geometry and surface energy of the sponge that allows water to be taken up and transported through the sponge. In passive transport, no external potential is required to motivate fluid flow through a device. A passive fluid transport device commonly used in medical procedures is an absorbent pad.
[0009] The present invention is directed to heat exchangers utilizing active fluid transport. The design of active fluid transport devices in general depends largely on the specific application to which it is to be applied. Specifically, fluid transport devices are designed based upon the volume, rate and dimensions of the particular application. This is particularly evident in active fluid transport heat exchangers, which are often required to be used in a specialized environment involving complex geometries. Moreover, the manner by which the fluid is introduced into the fluid transport device affects its design. For example, where fluid flow is between a first and second manifold, as is often the case with heat exchangers, one or multiple discrete paths can be defined between the manifolds.
[0010] In particular, in an active fluid transport heat exchanger, it is often desirable to control the fluid flow path. In one sense, the fluid flow path can be controlled for the purpose of running a particular fluid nearby an object or another fluid to remove heat from or to transfer heat to the object or other fluid in a specific application. In another sense, control of the fluid flow path can be desirable so that fluid flows according to specific flow characteristics. That is, fluid flow may be facilitated simply through a single conduit, between layers, or by way of plural channels. The fluid transport flow path may be defined by multiple discrete channels to control the fluid flow so as to, for example, minimize crossover or mixing between the discrete fluid channels. Heat exchange devices utilizing active fluid transport are also designed based upon the desired rate of heat transfer, which affects the volume and rate of the fluid flow through the heat exchanger, and on the dimensions of the heat exchanger.
[0011] Rigid heat exchangers having discrete microchannels are described in each of U.S. Pat. Nos. 5,527,588 to Camarda et al., 5,317,805 to Hoopman et al. (the '805 patent), and 5,249,358 to Tousignant et al. In each case, a microchanneled heat exchanger is produced by material deposition (such as by electroplating) about a sacrificial core, which is later removed to form the microchannels. In Camarda, the filaments are removed after deposition to form tubular passageways into which a working fluid is sealed. In the '805 patent to Hoopman et al, a heat exchanger comprising a first and second manifolds connected by a plurality of discrete microchannels is described. Similarly, U.S. Pat. No. 5,070,606 to Hoopman et al. describes a rigid apparatus having microchannels that can be used as a heat exchanger. The rigid microchanneled heat exchanger is made by forming a solid body about an arrangement of fibers that are subsequently removed to leave rmicrochannels within the solid formed body. A heat exchanger is also described in U.S. Pat. No. 4,871,623 to Hoopman et al. The heat exchanger provides a plurality of elongated enclosed electroformed channels that are formed by electrodepositing material on a mandrel having a plurality of elongated ridges. Material is deposited on the edges of the ridges at a faster rate than on the inner surfaces of the ridges to envelope grooves and thus create a solid body having microchannels. Rigid heat exchangers are also known having a series of micropatterned metal platelets that are stacked together. Rectangular channels (as seen in cross section) are defined by milling channels into the surfaces of the metal platelets by microtooling.
SUMMARY OF THE INVENTION
[0012] The present invention overcomes the shortcomings and disadvantages of known heat exchangers by providing a heat exchanger that utilizes active fluid transport through a highly distributed system of small discrete passages. More specifically, the present invention provides a method of manufacturing heat exchanger having plural channels, preferably microstructured channels, formed in a layer of polymeric material having a microstructured surface. The microstructured surface defines a plurality of microchannels that are completed by an adjacent layer to form discrete passages. The passages are utilized to permit active transport of a fluid to remove heat from or transfer heat to an object or fluid in proximity with the heat exchanger.
[0013] By the present invention, a heat exchanger is produced that can be designed for a wide variety of applications. The heat exchanger can be flexible or rigid depending on the material from which the layers, including the layer containing the microstructured channels, are comprised. The system of microchannels can be used to effectively control fluid flow through the device while minimizing mixing or crossover between channels. Preferably, the microstructure is replicated onto inexpensive but versatile polymeric films to define flow channels, preferably a microchanneled surface. This microstructure provides for effective and efficient active fluid transport while being suitable in the manufacturing of a heat exchanger for thermally effecting a fluid or object in proximity to the heat exchanger. Further, the small size of the flow channels, as well as their geometry, enable relatively high forces to be applied to the heat exchanger without collapse of the flow channels. This allows the fluid transport heat exchanger to be used in situations where it might otherwise collapse, i.e. under heavy objects or to be walked upon. In addition, such a microstructured film layer maintains its structural integrity over time.
[0014] The microstructure of the film layer defines at least a plurality of individual flow channels in the heat exchanger, which are preferably uninterrupted and highly ordered. These flow channels can take the form of linear, branching or dendritic type structures. A layer of thermally conductive material is applied to cover the microstructured surface so as to define plural substantially discrete flow passages. A source of potential—which means any source that provides a potential to move a fluid from one point to another—is also applied to the heat exchanger for the purpose of causing active fluid transport through the device. Preferably, the source is provided external to the microstructured surface so as to provide a potential over the flow passages to promote fluid movement through the flow passages from a first potential to a second potential. The use of a film layer having a microstructured surface in the heat exchanger facilitates the ability to highly distribute the potential across the assembly of channels.
[0015] By utilizing microstructured channels within the present invention, the heat transfer fluid is transported through a plurality of discrete passages that define thin fluid flows in the microstructured channels, which minimizes flow stagnation within the conducted fluid, and which promotes uniform residence time of the heat transfer fluid across the device in the direction of active fluid transport. These factors contribute to the overall efficiency of the device and allow for smaller temperature differentials between the heat transfer fluid and the media to be thermally effected. Moreover, the film surfaces having the microstructured channels can provide a high contact heat transfer surface area per unit volume of heat transfer fluid to increase the system's volumetric efficiency.
[0016] The above advantages of the present invention can be achieved by an active fluid transport heat exchanger including a layer of polymeric material having first and second major surfaces, wherein the first major surface is defined by a structured polymeric surface formed within the layer, the structured polymeric surface having a plurality of flow channels that extend from a first point to a second point along the surface of the layer. The flow channels preferably have a minimum aspect ratio of about 10:1, defined as the channel length divided by the hydraulic radius, and a hydraulic radius no greater than about 300 micrometers. A cover layer of material having favorable thermal conductive properties is positioned over the at least a plurality of the flow channels of the structured polymeric surface to define discrete flow passages from at least a plurality of the flow channels. A source is also provided external to the structured polymeric surface so as to provide a potential over the discrete flow passages to promote movement of fluid through the flow passages from a first potential to a second potential. In this manner, heat transfer between the moving fluid and the cover layer of thermally conductive material, and thus to a media to be thermally affected, can be achieved.
[0017] Preferably, also at least one manifold is provided in combination with the plurality of channels for supplying or receiving fluid flow through the channels of the structured surface of the heat exchanger.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] [0018]FIG. 1 is a perspective view of an active fluid transport heat exchanger in accordance with the invention having a structured layer combined with a cover layer of thermally conductive material to provide multiple discrete flow passages, and which passages are connected between a first manifold and a second manifold, the first manifold being connected to a source to provide a potential across the multiple discrete passages;
[0019] [0019]FIG. 2 is an enlarged partial cross-sectional view in perspective of the active fluid transport heat exchanger of FIG. 1 taken along line 2 - 2 of FIG. 1;
[0020] [0020]FIGS. 3 a through 3 c are end views of structured layers for illustrating possible flow channel configurations that may be used in a heat exchanger in accordance with the present invention;
[0021] [0021]FIG. 4 is an end view of a stack of microstructured layers that are disposed upon one another with thermally conductive cover layers interleaved within the stack so that bottom major surfaces of the cover layers close off the microstructured surface of a lower layer for defining multiple discrete flow passages;
[0022] [0022]FIGS. 5 a and 5 b are top views of structured layers for illustrating alternative non-linear channel structures that may be used in a heat exchanger in accordance with the present invention;
[0023] [0023]FIG. 6 is a perspective representation of a portion of an active fluid transport heat exchanger having a stack of microstructured layers disposed upon one another, with cover layers of thermally conductive material positioned between adjacent and opposing structured surfaces of the stacked layers to define discrete flow passages, the layers positioned in a manner that permits active fluid transport of two separate fluids through the flow passages to promote heat transfer from one fluid to the other fluid;
[0024] [0024]FIGS. 7 a and 7 b are partial end views of a pair of microstructured layers showing possible channel configurations with a layer of thermally conductive material disposed between the structured surfaces of the layers for permitting heat transfer between two fluids; and
[0025] [0025]FIG. 8 shows multiple uses of active fluid transfer devices, including the use of a flexible active fluid transfer heat exchanger positioned beneath a patient during a medical procedure to thermally affect the patient.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0026] With reference to the attached Figures, like components are labeled with like numerals throughout the several Figures. In FIGS. 1 and 2, an active fluid transfer heat exchanger 10 is illustrated. The active fluid transfer heat exchanger 10 basically includes a layer 12 of material having a structured surface 13 on one of its two major surfaces, a cover layer 20 of thermally conductive material, and a source 14 for providing a potential to the active fluid transfer heat exchanger 10 . Structured surface 13 of layer 12 can be provided defining a large number and high density of fluid flow channels 16 on a major surface thereof. The channels 16 (best shown in FIG. 2) are preferably arranged so that inlets are in fluidic communication with an inlet manifold 18 , while at another edge of the device 10 , an outlet manifold 19 can be fluidically connected to outlets of the channels 16 . Such an active fluid transfer device 10 provides for the circulation of a particular fluid through the device 10 by way of the inlet manifold 18 and outlet manifold 19 , whereby the fluid passing through the device 10 can be utilized to promote heat transfer through one or both of the layer 12 and the cover layer 20 of the device 10 .
[0027] The layer 12 may comprise flexible, semi-rigid, or rigid material, which may be chosen depending on the particular application of the active fluid transfer heat exchanger 10 . Preferably, the layer 12 comprises a polymeric material because such materials are typically less expensive and in that such polymeric materials can be accurately formed with a structured surface 13 . Structured surface 13 is preferably a microstructured surface. A great deal of versatility is available because of the many different properties of polymeric materials that are suitable for making microstructured surfaces. Polymeric materials may be chosen, for example, based on flexibility, rigidity, permeability, etc. Polymeric material provide numerous advantages as compared with other materials, including having reduced thermal expansion and contraction characteristics, and being compression conformable to the contours of an interface, non-corrosive, thermo-chromatic, electrically non-conductive, and having a wide range of thermal conductivity. Moreover, by the use of a polymeric layer 12 comprising, for example, a film layer, a structured surface can be provided defining a large number of and high density of fluid flow channels 16 on a major surface thereof. Thus, a highly distributed fluid transport system can be provided that is amenable to being manufactured with a high level of accuracy and economy.
[0028] The first and second manifolds 18 and 19 , respectively, preferably are in fluid communication with each of the fluid flow channels 16 through inlets and outlets (not shown) thereof, and are each provided with an internal chamber (not shown) that is defined therein and which is in fluid communication with channels 16 . Manifolds 18 and 19 are preferably fluidly sealed to the layers 12 and 20 by any known or developed technique, such as by conventional sealant. The internal chamber of inlet and outlet manifolds 18 and 19 are also thus sealingly connected to at least a plurality of the channels 16 . The manifolds 18 and 19 may be flexible, semi-rigid, or rigid, like the layer 12 .
[0029] To close off at least a plurality of the channels 16 and thus define discrete fluid flow passages, a cover layer 20 is preferably provided. At least a plurality of the channels 16 may be completed as flow passages by a closing surface 21 of the cover layer 20 . The cover layer 20 is also sealingly connected with the manifolds 18 and 19 so that plural discrete flow passages are formed that provide active fluid transport through heat exchanger 10 based upon the creation of a potential difference across the channels 16 from a first potential to a second potential. Cover layer 20 is preferably formed from a thermally conductive material to promote heat transfer between the fluid flowing through the flow passages and an element 17 , for example, that is desired to be thermally affected. It is contemplated that the element 17 to be thermally affected can comprise any number of objects, fluids, gases, or combinations thereof, depending upon a particular application.
[0030] Cover layer 20 can have a thermal conductivity that is greater than the layer 12 . Thermal conductivity is a quantifiable property of a specific material that characterizes its ability to transfer heat and in part determines the heat transfer rate through the material. Specifically, heat transfer rate is proportional to the physical dimensions, including cross-sectional profile and thickness, of a material and the difference in temperature in the material. The proportionality constant is defined as the material's thermal conductivity, and is expressed in terms of power per unit distance times degree. That is, when measuring heat transfer using metric units, thermal conductivity is expressed in terms of watts per meter-degree Celsius ((W/(m*° C.)). Substances that are good heat conductors have large thermal conductivity, while insulation substances have low thermal conductivity.
[0031] Moreover, it is contemplated that closing surface 21 may be provided from other than a cover layer 20 , such as by a surface of the object that is desired to be thermally affected. That is, the closing surface 21 can be part of any object which is intended to be thermally affected and to which layer 12 can be brought into contact. Such a construction can thus be used to promote heat transfer between fluid flowing in the passages defined between layer 12 and the closing surface 21 and the object to be thermally affected. As above, the closing surface 21 of an object may only close off at least a plurality of the channels 16 to thus define plural discrete fluid flow passages. The object and the layer 12 having a structured surface 13 may be constructed as a unit by assembling them together in a permanent manner, or the structured surface of the layer 12 may be temporarily held or otherwise maintained against the closing surface of the object. In the case of the former, one or more manifolds may be sealingly provided as part of the assembly. To the latter, one or more manifolds may be sealingly connected to just the layer 12 .
[0032] In accordance with the present invention, the potential source may comprise any means that provides a potential difference across a plurality of the flow passages from a first potential to a second potential. The potential difference should be sufficient to cause, or assist in causing, fluid flow through the discrete passages defined by plural flow channels 16 and cover layer 20 , which is based in part on the fluid characteristics of any particular application. As shown in FIG. 1, with the direction of fluid flow defined through inlet manifold 18 , through the body of heat exchanger 10 made up of layers 12 and 20 , and through outlet manifold 19 as indicated by the arrows, a potential source 14 may comprise a vacuum generator that is conventionally connected with a collector receptacle 26 . The collector receptacle 26 is fluidically connected with the outlet manifold 19 by way of a conventional flexible tube 24 . Thus, by the provision of a vacuum at the potential source 14 , fluid can be drawn from a fluid source 25 , provided outside the active fluid transfer heat exchanger 10 , through inlet manifold 18 , into the inlets (not shown), through the flow passages, through outlet manifold 19 , through tube 24 and into the collection receptacle 26 . The receptacle 26 may advantageously be connected with the source 25 to provide a recirculating system, in which case, it may be desirable to reheat or recool the fluid therein, prior to reuse. That is, receptacle 26 may be connected to a system whereby heat is transferred into or out of the fluid contained within receptacle 26 to restore the fluid to its initial temperature prior to being drawn through heat exchanger 10 . This restored fluid can then be supplied to fluid source 25 for reuse in heat exchanger 10 .
[0033] With flexible materials used for layers 12 and 20 , the mechanically flexible nature of such a heat exchanger 10 would allow it to be beneficially used in contoured configurations. Flexible devices may be relatively large so as to provide a highly distributed fluid flow, whereby a large area can be affected by the device. A flexible fluid transfer heat exchanger can take the form of a blanket, for example, for cooling or heating a patient. Such a flexible device can be conformable to an object, wrapped about an object, or may be conformable along with an object (e.g. provided on a cushion) to promote heat transfer therethrough. More specifically, the flexible nature of such a heat exchanger device improves the surface contact between it and the object to be thermally affected, which in turn promotes heat transfer. Although the fluid transfer device can be flexible, it can also demonstrate resistances to collapse from loads and kinking. The microstructure of the layer 12 , which may comprise a polymeric film, provides sufficient structure that can be utilized within an active fluid transfer heat exchanger in accordance with the present invention to have sufficient load-bearing integrity to support, for example, a standing person or a prone person.
[0034] As shown in FIG. 3 a , flow channels 16 can be defined in accordance with the illustrated embodiment by a series of peaks 28 . In some cases, it will be desirable to extend the peaks 28 entirely from one edge of the layer 12 to another; although, for other applications, it may be desirable to extend the peaks 28 only along a portion of the structured surface 13 . That is, channels 16 that are defined between peaks 28 may extend entirely from one edge to another edge of the layer 12 , or such channels 16 may only be defined to extend over a portion of the layer 12 . That channel portion may begin from an edge of the layer 12 , or may be entirely intermediately provided within the structured surface 13 of the layer 12 .
[0035] The closing surface 21 of a cover layer 20 or of a surface to be thermally affected may be bonded to peaks 28 of some or all of the structured surface 13 to enhance the creation of discrete flow passages within heat exchanger 10 . This can be done by the use of conventional adhesives that are compatible with the materials of the closing surface 21 and layer 12 , or may comprise other heat bonding, ultrasonic bonding or other mechanical devices, or the like. Bonds may be provided entirely along the peaks 28 to the closing surface 21 , or may be spot bonds that may be provided in accordance with an ordered pattern or randomly.
[0036] In the case where the potential source 14 comprises a vacuum generator, the vacuum provided to the channels 16 via outlet manifold 19 can be sufficient to adequately seal the closing surface 21 to the peaks 28 . That is, the vacuum itself will tend to hold the closing surface 21 against peaks 28 to form the discrete flow passages of heat exchanger 10 . Preferably, each of the channels 16 that are defined by the structured surface 13 is completely closed off by the closing surface 21 so as to define a maximum number of substantially discrete flow passages. Thus, crossover of fluid between channels 16 is effectively minimized, and the potential provided from an external source can be more effectively and efficiently distributed over the structured surface 13 of layer 12 . It is contemplated, however, that the structured surface 13 can include features within channels 16 that permit fluid crossover between the flow passages at certain points. This can be accomplished by not attaching portions of intermediate peaks 28 to closing surface 21 , or by providing openings through the peaks 28 at selected locations.
[0037] Other potential sources 14 are useable in accordance with the present invention instead of or in conjunction with a vacuum generation device. Generally, any manner of causing fluid flow through the flow passages is contemplated. That is, any external device or source of potential that causes or assists in fluid to be transported through the passages is contemplated. Examples of other potential sources include but are not limited to, vacuum pumps, pressure pumps and pressure systems, magnetic systems, magneto hydrodynamic drives, acoustic flow systems, centrifugal spinning, gravitational forces, and any other known or developed fluid drive system utilizing the creation of a potential difference that causes fluid flow to at least to some degree.
[0038] Although the embodiment of FIG. 1 is shown as having a structured surface comprising multiple peaks 28 continuously provided from one side edge to another (as shown in FIG. 3 a ), other configurations are contemplated. For example, as shown in FIG. 3 b , channels 16 ′ have a wider flat valley between slightly flattened peaks 28 ′. Like the FIG. 3 a embodiment, the thermally conductive cover layer 20 can be secured along one or more of the peaks 28 ′ to define discrete channels 16 ′. In this case, bottom surfaces 30 extend between channel sidewalls 31 , whereas in the FIG. 3 a embodiment, sidewalls 17 connect together along lines.
[0039] In FIG. 3 c , yet another configuration is illustrated. Wide channels 32 are defined between peaks 28 ″, but instead of providing a flat surface between channel sidewalls, a plurality of smaller peaks 33 are provided between the sidewalls of the peaks 28 ″. These smaller peaks 33 thus define secondary channels 34 therebetween. Peaks 33 may or may not rise to the same level as peaks 28 ″, and as illustrated create a first wide channel 32 including smaller channels 34 distributed therein. The peaks 28 ″ and 33 need not be evenly distributed with respect to themselves or each other.
[0040] Although FIGS. 1, 2, and 3 a - 3 c illustrate elongated, linearly-configured channels in layer 12 , the channels may be provided in many other configurations. For example, the channels could have varying cross-sectional widths along the channel length; that is, the channels could diverge and/or converge along the length of the channel. The channel sidewalls could also be contoured rather than being straight in the direction of extension of the channel, or in the channel height. Generally, any channel configuration that can provide at least multiple discrete channel portions that extend from a first point to a second point within the fluid transfer device are contemplated.
[0041] In FIG. 5 a , a channel configuration is illustrated in plan view that may be applied to the layer 12 to define the structured surface 13 . As shown, plural converging channels 36 having inlets (not shown) that can be connected to a manifold for receiving heat transfer fluid can be provided. Converging channels 36 are each fluidly connected with a single, common channel 38 . This minimizes the provision of outlet ports (not shown) to one. As shown in FIG. 5 b , a central channel 39 may be connected to a plurality of channel branches 37 that may be designed to cover a particular area for similar reasons. Again, generally any pattern is contemplated in accordance with the present invention as long as a plurality of individual channels are provided over a portion of the structured surface 13 from a first point to a second point. Like the above embodiments, the patterned channels shown in FIGS. 5 a and 5 b are preferably completed as flow passages by a closing surface such as provided by a surface of an object to be thermally affected or by a cover layer of thermally conductive material to define discrete flow passages and to promote heat transfer to a body to be thermally affected.
[0042] Individual flow channels of the microstructured surfaces of the invention may be substantially discrete. If so, fluid will be able to move through the channels independent of fluid in adjacent channels. Thus the channels can independently accommodate the potential relative to one another to direct a fluid along or through a particular channel independent of adjacent channels. Preferably, fluid that enters one flow channel does not, to any significant degree, enter an adjacent channel, although there may be some diffusion between adjacent channels. By maintaining discreteness of the micro-channels in order to effectively transport heat exchanger fluid, heat transfer to or from an object can be better promoted. Such benefits are detailed below.
[0043] As used here, aspect ratio means the ratio of a channel's length to its hydraulic radius, and hydraulic radius is the wettable cross-sectional area of a channel divided by its wettable channel circumference. The structured surface is a microstructured surface that preferably defines discrete flow channels that have a minimum aspect ratio (length/hydraulic radius) of 10:1, in some embodiments exceeding approximately 100:1, and in other embodiments at least about 1000:1. At the top end, the aspect ratio could be indefinitely high but generally would be less than about 1,000,000:1. The hydraulic radius of a channel is no greater than about 300 μm. In many embodiments, it can be less than 100 μm, and may be less than 10 μm. Although smaller is generally better for many applications (and the hydraulic radius could be submicron in size), the hydraulic radius typically would not be less than 1 μm for most embodiments. As more fully described below, channels defined within these parameters can provide efficient bulk fluid transport through an active fluid transport device.
[0044] The structured surface can also be provided with a very low profile. Thus, active fluid transport devices are contemplated where the structured polymeric layer has a thickness of less than 5000 micrometers, and even possibly less than 1500 micrometers. To do this, the channels may be defined by peaks that have a height of approximately 5 to 1200 micrometers and that have a peak distance of about 10 to 2000 micrometers.
[0045] Microstructured surfaces in accordance with the present invention provide flow systems in which the volume of the system is highly distributed. That is, the fluid volume that passes through such flow systems is distributed over a large area. Microstructure channel density from about 10 per lineal cm (25/in) and up to one thousand per lineal cm (2500/in) (measured across the channels) provide for high fluid transport rates. Generally, when a common manifold is employed, each individual channel has an aspect ratio that is at least 400 percent greater, and more preferably is at least 900 percent greater than a manifold that is disposed at the channel inlets and outlets. This significant increase in aspect ratio distributes the potential's effect to contribute to the noted benefits of the invention.
[0046] Distributing the volume of fluid through such a heat exchanger over a large area is particularly beneficial for many heat exchanger applications. Specifically, channels formed from microstructured surfaces provide for a large quantity of heat transfer to or from the volume of fluid passing through the device 10 . This volumetric flow of fluid is maintained in a plurality of thin uniform layers through the discrete passages defined by the microchannels of the structured surface and the cover layer, which minimizes flow stagnation in the conducted flow.
[0047] In another aspect, a plurality of layers 12 , each having a microstructured surface 13 , can be constructed to form a stack 40 , as shown in FIG. 4. This construction clearly multiples the ability of the structure to transport fluid. That is, each layer adds a multiple of the number of channels and flow capacity. It is understood that the layers may comprise different channel configurations and/or number of channels, depending on a particular application. Furthermore, it is noted that this type of stacked construction can be particularly suitable for applications that are restricted in width and therefore require a relatively narrow fluid transport heat exchanger from which a certain heat transfer rate, and thus a certain fluid transfer capacity, is desired. Thus, a narrow device can be made having increased flow capacity for heat exchange capacity.
[0048] In the stack 40 illustrated in FIG. 4, cover layers 20 are interleaved within the stack 40 to enhance heat exchange between adjacent structures. The cover layers 20 preferably comprise material having better thermal conductivity than the layers 12 for facilitating heat exchange between fluid flowing through the structured surface of one layer 12 and an adjacent layer 12 .
[0049] The stack 40 can comprise less cover layers 20 than the number of layers 12 or no cover layers 20 with a plurality of layers 12 . A second major surface (that is, the oppositely facing surface than structured surface 13 ) of any one of or all of the layers 12 can be utilized to directly contact an adjacent structured surface so as to close off at least a plurality of the channels 16 of an adjacent layer 12 and to define the plural discrete flow passages. That is, one layer 12 can comprise the cover layer for an adjacent layer 12 . Specifically, the second major surface of one layer 12 can function for closing plural channels 16 of an adjacent layer 12 in the same manner as a non-structured cover layer 20 . In the case where it is desirable to facilitate heat transfer with an object external to the stack 40 , intermediate non-structured cover layers 20 may not be needed although one cover layer 20 may be provided as the top surface (as viewed in FIG. 4) for thermally affecting the object by that top cover layer 20 . The layers of stack 40 (plural layers 12 with or without non-structured cover layers 20 ) may be bonded to one another in any number of conventional ways, or they may simply be stacked upon one another whereby the structural integrity of the stack can adequately define discrete flow passages. This ability is enhanced, as above, in the case where a vacuum is to be utilized as the potential source which will tend to secure the layers of stack 40 against each other or against cover layers interposed between the individual layers. The channels 16 of any one layer 12 may be connected to a different fluid source from another or all to the same source. Thus, heat exchange can be accomplished between two or more fluids circulated within the stack 40 .
[0050] A layered construction comprising a stack of polymeric layers, each having a microstructured surface, is advantageously useable in the making of a heat exchanger 110 for rapidly cooling or heating a second fluid source, such as is represented in FIG. 6. The heat exchanger 110 of FIG. 6 employs a stack of individual polymeric layers 112 having a structured surface 113 over one major surface thereof which define flow channels 116 in layer 112 . The direction of the flow channels 116 of each individual layer 112 may be different from, and, as shown can be substantially perpendicular to, the direction of the flow channels of an adjacent layer 112 . In this manner, channels 116 of layer 112 a of heat exchanger 110 can promote fluid flow in a longitudinal direction, while channels 116 of layer 112 b promote fluid flow in a transverse direction through heat exchanger 110 .
[0051] As above, the second major surface of layers 112 can act as a cover layer closing the channels 116 defined by the microstructured surface 113 of an adjacent layer 112 . Alternatively, as shown in FIG. 6, cover layers 120 can be interposed between the opposing first major surfaces in which structured surfaces 113 are formed of adjacent layers 112 a and 112 b . That is, the layers 112 a having channels 116 aligned in a longitudinal direction are inverted from the configuration associated with stack 40 of FIG. 4 so that structured surface 113 of these longitudinal layers 112 a face the structured surface 113 of the transverse layer 112 b immediately beneath layer 112 a . In this manner, cover layer 120 is directly interposed between flow channels 116 of opposing layers 112 to close off channels 116 of each adjacent layer 112 , and thus define longitudinal and transverse discrete flow passages.
[0052] A first potential can be applied across the longitudinal layers 112 a to promote fluid flow from a first fluid source through the flow passages of longitudinal layers 112 a . A second potential can be applied across the transverse layers 112 b to promote flow fluid from a second fluid source. In this manner, cover layer 120 is interposed between a pair of opposing fluid flows. Heat transfer from the first fluid flow can thereby be effected across cover layer 120 to rapidly heat or chill the second fluid source. As above, microstructured surfaces 113 of layers 112 promote a plurality of uniform thin fluid flows through the flow passages of heat exchanger 110 , thus aiding in the rapid heat transfer between the opposing flows. Any number of sources can be used for selectively generating fluid flow within any number of the channels within a layer or between any of the layers.
[0053] [0053]FIG. 6 further illustrates a cover layer 120 attached to the second major surface of the top layer 112 a of heat exchanger 110 . This top cover layer 120 can be beneficially used to thermally affect a desired media or other fluid by receiving heat transfer from the first fluid in flow channels 116 through the second major surface of the layer 112 a . Depending on the material chosen for layer 112 a , the top cover layer 120 can provide less heat transfer than the cover layers 120 that are interposed directly between the opposing fluid flows of heat exchanger 110 for beneficially providing a lower rate of heat transfer to sensitive media to be thermally affected, such as for example, living tissue, while still permitting heat exchanger 110 to act as a rapid fluid-to-fluid heat transfer device.
[0054] While heat exchanger 110 of FIG. 6 shows the flow channels 116 of alternating layers 112 aligned substantially perpendicular to each other, the microstructure channels of the alternating layers associated with the separate fluid flows can be arranged in any number of manners as required by a specific application. For example, FIG. 7 a illustrates a layer 212 a that can receive fluid from a first source and a second layer 212 b that can receive fluid from a second source that is distinct from the first source. Each of the layers 212 a and 212 b have channels 216 formed on a first major surface of the respective layers. Cover layer 220 of thermally conductive material is interposed between the channels 216 of layers 212 a and 212 b to define discrete flow passages and to promote heat transfer between a first fluid flow across layer 212 a and a second fluid flow across layer 212 b . Channels 216 of layers 212 a and 212 b are aligned substantially parallel with respect to each other. In the embodiment of FIG. 7 a , peaks 228 of the channels 216 of layers 212 a and 212 b are aligned opposite each other. FIG. 7 b shows layers 212 a and 212 b having peaks 228 of layers 212 a that are aligned between peaks 228 of opposing layer 212 b.
[0055] Many other configurations of a stack of layers having a microstructured surface are also contemplated. For example, the channels may be aligned parallel to each other as in FIGS. 7 a and 7 b , or perpendicular as in FIG. 6, or arranged in any other angular relation to each other as required by a specific application. Individual layers of a heat exchanger having a plurality of stacked layers can contain more or less microstructured channels as compared to other layers in the stack, and the flow channels may be linear or non-linear in one or more layers of a stacked structure.
[0056] It is further contemplated that a stacked construction of layers in accordance with those described herein may include plural stacks arranged next to one another. That is, a stack such as shown in FIG. 4 or FIG. 6 may be arranged adjacent to a similar or different stack. Then, they can be collected together by an adapter, or may be individually attached to fluid transfer tubing, or the like to provide heat transfer in a desired manner.
[0057] An example of an active fluid transfer heat exchanger in accordance with the present invention is illustrated in FIG. 8. In the medical field of usage, a patient is shown positioned on an active fluid transport heat exchanger 70 (that may be in the form of a flexible blanket) such as is described above for thermally affecting the patient (e.g. with heating or cooling).
[0058] Heat transfer devices of these constructions possess some benefits. Because the heat transfer fluid can be maintained in very small channels, there would be minimal fluid stagnation in the channels. Fluids in laminar flow in channels exhibit a velocity flow profile where the fluid at the channel's center has the greatest velocity. Fluid at the channel boundary in such flow regimes is essentially stagnate. Depending on the size of a channel, the thermal conductivity of the fluid, and the amount of time a fluid spends moving down the channel, this flow profile can create a significant temperature gradient across the channel. In contrast, channels that have a minimum aspect ratio and a hydraulic radius in accordance with the invention will display a smaller temperature gradient across the channel because of the small heat transfer distance. A smaller temperature gradient is advantageous as the fluid will experience a uniform heat load as it passes through the channel.
[0059] Residence time of the heat transfer fluid throughout the system of small channels also can be essentially uniform from an inlet manifold to an outlet manifold. A uniform residence time is beneficial because it minimizes non-uniformity in the heat load a fluid experiences.
[0060] The reduction in temperature gradient and the expression of a uniform residence time also contribute to overall efficiency and, for a given rate of heat transfer, allow for smaller temperature differentials between the heat transfer fluid and the element to be heated or cooled. The smaller temperature differentials reduce the chance for local hot or cold zones that would be undesirable when the heat exchanger is used in thermally sensitive applications such as skin or tissue contact. The high contact surface area, per unit volume of heat transfer fluid, within the heat transfer module increases the system's volumetric efficiency.
[0061] The heat transfer device may also be particularly useful in confined areas. For example, a heat exchanger in accordance with the present invention can be used to provide cooling to a computer microchip within the small spaces of a data storage or processing unit. The material economics of a microstructure-bearing film based unit would make them appropriate for limited or single use applications, such as in medical devices, where disposal is required to address contamination concerns.
[0062] A heat transfer device of the invention is beneficial in that it can be flexible, allowing its use in various applications. The device can be contoured around tight bends or curves. The flexibility allows the devices to be used in situations that require intimate contact to irregular surfaces. The inventive fluid transport heat exchanger, may be fashioned to be so flexible that the devices can be conformed about a mandrel that has a diameter of approximately one inch (2.54 cm) or greater without significantly constricting the flow channels or the structured polymeric layer. The inventive devices also could be fashioned from polymeric materials that allow the heat exchanger to be non-detrimentally conformed about a mandrel that is approximately 1 cm in diameter.
[0063] The making of structured surfaces, and in particular microstructured surfaces, on a polymeric layer such as a polymeric film are disclosed in U.S. Pat. Nos. 5,069,403 and 5,133,516, both to Marentic et al. Structured layers may also be continuously microreplicated using the principles or steps described in U.S. Pat. No. 5,691,846 to Benson, Jr. et al. Other patents that describe microstructured surfaces include U.S. Pat. Nos. 5,514,120 to Johnston et al., 5,158,557 to Noreen et al., 5,175,030 to Lu et al., and 4,668,558 to Barber.
[0064] Structured polymeric layers produced in accordance with such techniques can be microreplicated. The provision of microreplicated structured layers is beneficial because the surfaces can be mass produced without substantial variation from product-to-product and without using relatively complicated processing techniques. “Microreplication” or “microreplicated” means the production of a microstructured surface through a process where the structured surface features retain an individual feature fidelity during manufacture, from product-to-product, that varies no more than about 50 μm. The microreplicated surfaces preferably are produced such that the structured surface features retain an individual feature fidelity during manufacture, from product-to-product, which varies no more than 25 μm.
[0065] Fluid transport layers for any of the embodiments in accordance with the present invention can be formed from a variety of polymers or copolymers including thermoplastic, thermoset, and curable polymers. As used here, thermoplastic, as differentiated from thermoset, refers to a polymer which softens and melts when exposed to heat and re-solidifies when cooled and can be melted and solidified through many cycles. A thermoset polymer, on the other hand, irreversibly solidifies when heated and cooled. A cured polymer system, in which polymer chains are interconnected or crosslinked, can be formed at room temperature through use of chemical agents or ionizing irradiation.
[0066] Polymers useful in forming a structured layer in articles of the invention include but are not limited to polyolefins such as polyethylene and polyethylene copolymers, polyvinylidene diflouride (PVDF), and polytetrafluoroethylene (PTFE). Other polymeric materials include acetates, cellulose ethers, polyvinyl alcohols, polysaccharides, polyolefins, polyesters, polyamids, poly(vinyl chloride), polyurethanes, polyureas, polycarbonates, and polystyrene. Structured layers can be cast from curable resin materials such as acrylates or epoxies and cured through free radical pathways promoted chemically, by exposure to heat, UV, or electron beam radiation.
[0067] As indicated above, there are applications where flexible active fluid transport heat exchangers are desired. Flexibility may be imparted to a structured polymeric layer using polymers described in U.S. Pat. Nos. 5,450,235 to Smith et al. and 5,691,846 to Benson, Jr. et al. The whole polymeric layer need not be made from a flexible polymeric material. A main portion of the layer, for example, could comprise a flexible polymer, whereas the structured portion or portion thereof could comprise a more rigid polymer. The patents cited in this paragraph describe use of polymers in this fashion to produce flexible products that have microstructured surfaces.
[0068] Polymeric materials including polymer blends can be modified through melt blending of plasticizing active agents such as surfactants or antimicrobial agents. Surface modification of the structured surfaces can be accomplished through vapor deposition or covalent grafting of functional moieties using ionizing radiation. Methods and techniques for graft-polymerization of monomers onto polypropylene, for example, by ionizing radiation are disclosed in U.S. Pat. Nos. 4,950,549 and 5,078,925. The polymers may also contain additives that impart various properties into the polymeric structured layer. For example, plasticisers can be added to decrease elastic modulus to improve flexibility.
[0069] Preferred embodiments of the invention may use thin flexible polymer films that have parallel linear topographies as the microstructure-bearing element. For purposes of this invention, a “film” is considered to be a thin (less than 5 mm thick) generally flexible sheet of polymeric material. The economic value in using inexpensive films with highly defined microstructure-bearing film surfaces is great. Flexible films can be used in combination with a wide range of cover layer materials and can be used unsupported or in conjunction with a supporting body where desired. The heat exchanger devices formed from such microstructured surfaces and cover layers may be flexible for many applications but also may be associated with a rigid structural body where applications warrant.
[0070] Because the active fluid transport heat exchangers of the invention preferably include microstructured channels, the devices commonly employ a multitude of channels per device. As shown in some of the embodiments illustrated above, inventive active fluid transport heat exchangers can easily possess more than 10 or 100 channels per device. Some applications, the active fluid transport heat exchanger may have more than 1,000 or 10,000 channels per device. The more channels that are connected to an individual potential source allow the potential's effect to be more highly distributed.
[0071] The inventive active fluid transport heat exchangers of the invention may have as many as 10,000 channel inlets per square centimeter cross section area. Active fluid transport heat exchangers of the invention may have at least 50 channel inlets per square centimenter. Typical devices can have about 1,000 channel inlets per square centimeter.
[0072] As noted above in the Background section, examples of heat exchangers having microscale flow pathways are known in the art. Sacrificial cores or fibers are removed from a body of deposited material to form the microscale pathways. The application range of such devices formed from these fibers are limited, however. Fiber fragility and the general difficulty of handling bundles of small individual elements hampers their use. High unit cost, fowling, and lack of geometric (profile) flexibility further limits application of these fibers as fluid transport means. The inability to practically order long lengths and large numbers of hollow fibers into useful transport arrays make their use inappropriate for all but a limited range of active fluid transport heat exchange applications.
[0073] The cover layer material, described above with respect to the illustrated embodiments, or the surface of an object to be thermally affected provide the closing surface that encloses at least a portion of at least one microstructured surface so as to create plural discrete flow passages through which fluid may move. A cover layer provides a thermally conductive material for promoting heat transfer to a desired object or media. The interior surface of the cover layer material is defined as the closing surface facing and in at least partial contact with the microstructured polymeric surface. The cover layer material is preferably selected for the particular heat exchange application, and may be of similar or dissimilar composition to the microstructure-bearing surface. Materials useful as the cover layer include but are not limited to copper and aluminum foils, a metalisized coated polymer, a metal doped polymer, or any other material that enhances heat transfer in the sense that the material is a good conductor of heat as required for a desired application. In particular, a material that has improved thermal conductivity properties as compared to the polymer of the layer containing the microstructure surface and that can be made on a film or a foil is desirable.
EXAMPLE
[0074] To determine the efficacy of an active fluid transport heat exchanger having a plurality of discrete flow passages defined by a layer having microchannels in a microstructured surface and a cover layer, a heating and cooling device was constructed using a capillary module formed from a microstructure-bearing film element, capped with a layer of metal foil. The microstructure-bearing film was formed by casting a molten polymer onto a microstructured nickel tool to form a continuous film with channels on one surface. The channels were formed in the continuous length of the cast film. The nickel casting tool was produced by shaping a smooth copper surface with diamond scoring tools to produce the desired structure followed by an electroless nickel plating step to form a nickel tool. The tool used to form the film produced a microstructured surface with abutted ‘V’ channels with a nominal depth of 459 μm and an opening width of 420 μm. This resulted in a channel, when closed with a cover layer, with a mean hydraulic radius of 62.5 μm. The polymer used to form the film was low density polyethylene, Tenite™ 1550P from Eastman Chemical Company. A nonionic surfactant, Triton X-102 from Rohm & Haas Company, was melt blended into the base polymer to increase the surface energy of the film.
[0075] The surface dimension of the laminate was 80 mm×60 mm. The metal foil used was a sheet of aluminum with a thickness of 0.016 mm, from Reynolds Co. The foil and film were heat welded along the two sides parallel to the linear microstructure of the film. In this manner, substantially discrete flow passages were formed.
[0076] A pair of manifolds were then fitted over the ends of the capillary module. The manifolds were formed by placing a cut in the side wall of a section of tubing, VI grade 3.18 mm inner diameter, 1.6 mm wall thickness tubing from Nalge Co. of Rochester, N.Y. The slit was cut with a razor in a straight line along the axis of each tube. The length of the slit was approximately the width of the capillary module. Each tube was then fitted over an end of the capillary module and hot melt glued in place. One open end of the tubes, at the capillary module, was sealed closed with hot melt adhesive.
[0077] To evaluate the heat transfer capacity of the test module, water was drawn through the module and cooled by an ice bath placed in direct contact with the foil surface. The temperature of the inlet water to the heat exchange module was 34° C. with the corresponding bath temperature at 0° C. Water was drawn through the unit at the rate of 150 ml/min while a slight agitation of the ice bath was maintained. The volume of water drawn through the test module was 500 ml. Temperature of the conditioned water was 20° C. The drop in temperature of the transported fluid demonstrates the effectiveness of the test module to transfer and remove heat.
[0078] All of the patents and patent applications cited above are wholly incorporated by reference into this document. Also, this application also wholly incorporates by reference the following patent applications that are commonly owned by the assignee of the subject application and were filed on the same day as the parent application: U.S. patent application Ser. No. 09/099,269, to Insley et al. and entitled “Microchanneled Active Fluid Transport Devices”; U.S. patent application Ser. No. 09/106,506, to Insley et al. and entitled “Structured Surface Filtration Media”; U.S. patent application Ser. No. 09/100,163, to Insley et al. and entitled “Microstructured Separation Device”; and U.S. patent application Ser. No. 09/099,565, to Insley et al. and entitled “Fluid Guide Device Having an Open Microstructured Surface for Attachment to a Fluid Transport Device.”
[0079] Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. | A heat exchanger utilizing active fluid transport of a heat transfer fluid is manufactured with multiple discrete flow passages provided by a simple but versatile construction. The microstructured channels are replicated onto a film layer which is utilized in the fluid transfer heat exchanger. The surface structure defines the flow channels which are generally uninterrupted and highly ordered. These flow channels can take the form of linear, branching or dendritic type structures. A cover layer having favorably thermal conductive properties is provided on the structured bearing film surface. Such structured bearing film surfaces and the cover layer are thus used to define microstructure flow passages. The use of a film layer having a microstructured surface facilitates the ability to highly distribute a potential across the assembly of passages to promote active transport of a heat transfer fluid. The thermally conductive cover layer then effects heat transfer to an object, gas, or liquid in proximity with the heat exchanger. | 8 |
BACKGROUND AND SUMMARY OF THE INVENTION
This application claims the priority of German Patent No. 19918513.1, filed Apr. 23, 1999, the disclosure of which is expressly incorporated by reference herein.
The invention relates to an electric drive arrangement for internal combustion engines in motor vehicles having an electric starter coupled to the internal combustion engine, and an electric generator drive connected with the internal combustion engine.
For decades, internal combustion engines in road vehicles have been started by means of an electronic starter which is connected mechanically to the crankshaft of the internal combustion engine via its starter pinion and the ring gear on the flywheel only during the starting phase. Nowadays, all starter motors have the torque characteristic of a series-wound machine, which is characterized essentially by an output torque which falls continuously to zero as the speed increases, beginning with the maximum possible torque at standstill. During the starting operation this characteristic leads to a torque equilibrium between the starter torque and the drag torque of the internal combustion engine at crankshaft speeds of between 80 and 200 rpm, which are sufficient for starting according to the requirements which have applied hitherto. To make these starter motors as small, light and cheap as possible, d.c. machines of series-wound construction or with permanent-magnetic excitation and as large as possible a transmission ratio relative to the crankshaft have been used. A total transmission ratio of the intermediate gear in the starter and the transmission ratio of the starter pinion relative to the crankshaft is about 60:1. This high transmission ratio necessitates an engagement device which establishes a driving connection with the crankshaft only when the starter is actuated and hence protects the starter motor from extreme speeds.
Future exhaust regulations will make the design of the above-described starting system inadequate. The minimum starting speeds hitherto stipulated at the crankshaft lead to high pollutant emissions in the current starting operation and it is known that there is considerable potential for improvement in this area by raising the starting speed to values within the range of the idling speed of the internal combustion engine.
Another disadvantage of current starting systems is that starting operations last a relatively long time and are relatively loud due to the high transmission ratio of the starter relative to the crankshaft and the necessary engagement and disengagement of the starter pinion. This is becoming less and less acceptable to the customer, especially as future operating concepts for vehicles aimed at achieving fleet consumption targets will require a significantly larger number of starting operations. This will result in problems with the life of current starting systems.
European Patent 0 793 013 A1 discloses a starting operation using a belt-driven generator instead of a conventional starter. Problems arise at very low temperatures since the maximum torque of such an arrangement is no longer sufficient to start the engine reliably under such circumstances. Therefore such systems are restricted to internal combustion engines with small displacements, at best. If a design for large internal combustion engines were implemented which also operated reliably at low temperatures, this would lead to unacceptable large, heavy and expensive generators.
European Patent 0 406 182 B1 attempts to solve this problem by using a boost circuit to generate a higher voltage for starting, briefly bringing about higher currents in the generator—operated as a motor—and hence increasing torque. However, this solution has the disadvantage that the belt drive loses adhesion at low temperatures and tends to slip. In addition, the charging time of the starting energy storage is disruptive, thereby rendering it impossible to perform starting operations is rapid succession. The life of such an arrangement is furthermore inadequate for the future concepts, which necessitate a large number of starting operations.
One object of the present invention is an economical electric drive arrangement for internal combustion engines which provides more rapid and more comfortable starting operation, and which also takes place reliably at low temperatures.
In particular, the drive arrangement according to the invention has the advantage that, in combined operation, the driving torques of the generator and the starter are superimposed in an effective manner since the torque of the active generator cuts in precisely when the starter begins to slacken off. The crankshaft of the internal combustion engine is thereby accelerated very rapidly to well beyond the speed that can currently be achieved by a starter, thus ensuring rapid and reliable starting even at low temperatures. In the case of a cold start, a division of tasks occurs between the conventional starter (overcoming the break-away torque) and the generator (increasing the cranking torque in the range of higher crankshaft speeds). Over dimensioning of the generator together with the power electronics and an unwanted intervention in the drive line can be avoided, and a starter, can be used virtually unaltered. The solution according to the invention thus represents an optimum cost solution. At higher outside temperatures and/or with a warm engine, the starting operation can be performed solely with the generator, thereby enabling particularly comfortable starting with particularly little noise. The electronic control device advantageously decides the starting operation mode as a function of at least on temperature sensor.
The semiconductor circuit to accomplish the present invention can advantageously be connected as an inverter for motor operation of the generator, which is designed as an a.c. or d.c. generator, and as a rectifier for generator operation, making it possible to use a single semiconductor circuit for both modes of operation, with a corresponding improvement in efficiency by active rectification in the generator mode.
The decision as to whether the starting operation should be performed solely by means of the generator operated as a motor or by means of this generator in combination with the starter is made in an optimum manner by the electronic control device as a function of the engine-oil temperature and/or the outside temperature and/or the off time of the internal combustion engine. To start the internal combustion engine at low temperature, the generator and the starter can be switched on simultaneously or in succession with or without a time overlap. These variants can, for example, be chosen as alternatives depending on the respective starting parameters.
It is further advantageous that the electronic control device be designed to set a defined angular position of the crankshaft of the internal combustion engine when switching the engine off with the aid of the generator, which is operated as a motor. For this purpose, the generator is, for example, designed as a fully functional four-quadrant positioning drive. This allows the next starting operation to take place from a defined initial position, thereby considerably speeding up the starting operation and considerably reducing pollutant emissions. Moreover, one of the hitherto customary sensors, either the TDC (Top Dead Center) sensor or the camshaft sensor can be omitted. Activating the ignition and/or injection during the starting operation of the internal combustion engine only at speeds close to the starting speed, e.g. at 80% of the starting speed is particularly favourable for low energy consumption and low pollutant emissions.
The electronic control device can also advantageously be used to support deceleration operations of the internal combustion engine by switching on the generator, operated in the generator mode, and/or to assist acceleration operations of the internal combustion engine by switching on the generator, which operated in the motor mode. For example, operation of the generator as a motor can be used to assist driving dynamics while the internal combustion engine is running, i.e. as an intervention of the active generator for the purpose of assistance during all acceleration processes of the internal combustion engine. On the other hand, it is also possible for rotational energy of the internal combustion engine to be recovered when the generator is operated as a generator, especially in overrun and braking mode, with the result that the generator additionally assists the desired deceleration process. This mode selection takes place most efficiently as a function of the speed of the internal combustion engine.
The active generator can also advantageously be involved in synchronizing the engine and gearbox speeds during gear changes in manual gearboxes. The energy which has to be converted in the synchronizer rings of the gearbox to equalize the rotational speeds can be recovered by means of the generator, and, in addition, more rapid gear changes are obtained, possibly even eliminating the need for synchronizer rings and a clutch, given appropriate design. During a prospective gear change, the engine is controlled in such a way with the assistance of the generator that no torque is transmitted in the drive line. The respective gear can then be disengaged. Re-equalization of the speed then takes place with the aid of an electronic accelerator or with the aid of an electronic throttle valve and electronic assistance. When the engine speed has been synchronized with the new gearbox speed, no jerking movement occurs during the new gear engagement.
It is also possible to prevent excessive device belt slip between the internal combustion engine and the generator by switching on generator operation of the generator or motor operation of the generator. Additional torques at the belt drive can thereby be connected and disconnected or compensated for in a manner which spares the belt, thus increasing the life of the drive belt and largely preventing defects.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a schematic representation of an internal combustion engine provided with a starter and an electric generator and
FIG. 2 shows a diagram to illustrate the mode of operation.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In the exemplary embodiment illustrated in FIG. 1, a schematically represented internal combustion engine 10 of a motor vehicle is provided with a starter 11 and an electric generator 12 , the electric generator 12 being coupled to the internal combustion engine 10 by a (not shown) belt drive.
The starter 11 is connected directly to a supply battery 14 , and the electric generator 12 is connected to the battery via a semiconductor circuit arrangement 13 .
An electronic control device 15 controls the starter 11 and the semiconductor circuit arrangement 13 as a function of sensor signals and start control signals which the control device 15 obtains by means of a starter switch 16 , which can be integrated into the ignition lock and/or designed as a separate starter switch. In the exemplary embodiment, the control device 15 is supplied with sensor signals by an external temperature sensor 17 , an oil temperature sensor 18 and an intake-pipe pressure sensor 19 . However, the control device 15 can, in addition, be supplied with, for example, sensor signals which are dependent on the battery load state, the battery voltage, the current of the battery and the on-board electrical system, the engine speed, pedal positions or parameter switches.
Depending on the operating condition, the semiconductor circuit arrangement 13 receives control signals, from the control device 15 , for motor (active) or generator operation of the generator 12 . For generator operation, the semiconductor switch arrangement 13 is connected as a rectifier or rectifier bridge while, for motor operation, the switch is connected as an inverter for the generator 12 designed as an a.c. or d.c. generator.
In response to a starting signal from the starter switch 16 , the electronic control device 15 activates the starter 11 and connects the semiconductor circuit arrangement 13 as an inverter. As a result, the starter 11 and the generator 12 perform the starting operation of the internal combustion engine 10 jointly. FIG. 2 shows the torques and the mechanical power of the starter 11 and the generator 12 at the crankshaft, the solid lines representing the torques and the broken lines the powers as a function of the crankshaft speed. This illustration shows that the initially high torque of the starter falls rapidly and continuously to vanishingly small values as the rotational speed increases, and the initially increasing power likewise falls below even 300 rpm, to a value of essentially zero. In contrast, the torque of the generator 12 is constant and the power rises in an essentially linear manner. The diagram thus shows that the torque of the active generator cuts in precisely when that of the starter begins to slacken off. The superimposition of the two driving torques takes effect at the crankshaft and accelerates it well beyond the speed that can be achieved nowadays with a starter.
This combined operation is necessary particularly in the case of a cold start and low outside temperatures since the conventional starter 11 has an initially very high driving torque which is effective even at low temperatures.
When the internal combustion engine 10 is warm or the outside temperatures are high, only the electric generator 12 is required for the starting operation. Thus, the semiconductor circuit arrangement 13 is accordingly merely connected as an inverter to provide motor operation of the generator 12 .
These two different starting processes, i.e. cold starting and warm starting, are stored as an algorithm in the control device 15 as a function of corresponding sensor signals. For example, a cold start can be defined by the engine-oil temperature and the outside temperature being below a predeterminable value and/or by the off time since the last operation of the internal combustion engine being greater than a predeterminable time period. A warm start is defined engine-oil temperatures and outside temperatures above definable values and/or at off times smaller than a predeterminable time period. It is also possible for the relationship between these sensor variables to be defined by a particular function.
For cold starting, two different starting methods can be implemented. In one starting method, the generator operates as a motor in parallel with the starter 11 . In this case, the starter is deactivated at a certain speed and the generator, operating as a motor, accelerates the crankshaft further to the starting speed.
In the second variant, the starter 11 is switched on first and only when a certain speed has been reached is it deactivated and the generator, operated as a motor, is activated. To lower consumption and reduce noxious exhaust gases, no injection and no ignition are carried out until a speed value corresponding, for example, to 80% of the starting speed is reached, and the internal combustion engine 10 is thus only started at this point. This starting operation takes place very rapidly by means of an electronic engine control system (not shown), which can be operatively connected to the electronic control device 15 . This delayed onset of ignition and injection also takes place in a corresponding manner in the case of a starting operation solely by means of the generator 12 .
Customary starters 11 have a total transmission ratio of about 60:1, this being obtained from the transmission ratio of the starter pinion to the crankshaft and by the intermediate-gear transmission ratio. In the arrangement according to the invention, this transmission ratio can be significantly reduced. That is, the intermediate gear can, for example, be omitted, thus giving a total transmission ratio of 15:1.
Independently of the starting operation, the electronic control device 15 can also control the generator 12 to assist with driving dynamics, for example, while the internal combustion engine 10 is running. In all acceleration operations of the internal combustion engine 10 , for example, the generator 12 —operated as a motor—can assist these acceleration operations. On the other hand, it can also assist deceleration operations in generator mode, i.e. it is operated as a generator in overrun mode and braking mode, with the result that not only is electric energy recovered, depending on the driving situation, but the deceleration process is also actively assisted.
The electronic control device 15 can furthermore actively assist shift operations during gear changing in the gearbox of the internal combustion engine 10 and be used to synchronize engine and gearbox speeds. To increase the speed, the generator 12 is operated as a motor and to reduce the speed the generator 12 is operated as a generator. This leads to faster gear changes, thereby making it possible to omit even a clutch under certain circumstances.
The electronic control device 15 can furthermore be used to prevent belt slip of the generator 12 . A measuring device (not shown) for detecting belt slip transmits its measurement signals to the electronic control device 15 , which uses the active generator 12 to couple or decouple or compensate, in a manner which reduces additional torque on the belt. This measurement device for detecting belt slip can also be part of the electronic control device 15 , where the speeds of the generator 12 and the internal combustion engine 10 are compared with one another. For belt slip detection, it is possible, for example, for a measurement roller to be resiliently and pivotally connected to the forward strand and the return strand of the drive belt, these measurement rollers detecting the stretching of the drive belt due to different torques. Detection of the belt slip allows preventive belt diagnosis and the risk of a problem with the belt can be communicated to the driver of a motor vehicle at an early stage, e.g. by means of an optical and/or acoustic warning device or a display.
The electronic control device 15 can furthermore be used to position the crankshaft. When the internal combustion engine is switched off, a favourable well-defined initial position is imposed on the crankshaft by the generator 12 , which is operated as a motor. For this purpose, the generator is, for example, designed as a fully functional four-quadrant positioning drive. As a result, the next starting operation of the internal combustion engine can be performed from a defined initial position, thereby considerably speeding up the starting operation.
The arrangement according to the invention is also suitable for controlling or influencing the running down of the internal combustion engine 10 . Undefined quantities of fuel often remain in the intake system and the cylinders when the internal combustion engine 10 is switched off. The highly volatile components of the fuel evaporate, however, the poorly combustible components do not evaporate. They impair the quality of the exhaust gas when the internal combustion engine is restarted. This problem is circumvented in a refinement of the invention by switching off the fuel supply or fuel injection when the internal combustion engine 10 is switched off. The revolution of the internal combustion engine 10 is maintained for a certain time by the generator 12 in motor mode, thereby flushing the internal combustion engine and harmlessly disposing of fuel residues, which may also be in the catalytic converter. When the internal combustion engine is restarted, the engine control unit or control device 15 can assume that the internal combustion engine is “empty” and this makes a defined start easier.
After flushing and the disposal of the fuel residues, the internal combustion engine 10 can be braked to a halt in a defined manner with the generator 12 in generator mode since a long after-running phase is not desirable.
Another application of the drive arrangement according to the invention is the improvement of the start/stop operations of the internal combustion engine 10 , e.g. at traffic lights. Opportunities for implementation increase especially if the internal combustion engine or motor vehicle can be started without delay. Even the slightest delays are viewed by an operator as being extremely irritating. With the aid of the electronic control device 15 in conjunction with the generator 12 , it is possible to stop the vehicle without disconnecting the internal combustion engine. Any other torque shocks which occur can be compensated for by the generator in a comfortable manner. Starting is then likewise performed once more without operating a clutch, by “electrical” drive-away, this being possible completely without a delay. This can, of course, also be performed with the internal combustion engine disconnected. In motor operation of the generator 12 , purely electrical drive-away may take place with assistance from the starter 11 , particularly when the internal combustion engine is cold or temperatures are very low. The starting or connection of the internal combustion engine 10 can then be performed with something of a time delay, in particular in a pulsed manner. Since, during starting of the internal combustion engine, the vehicle is then already in motion, the kinetic energy of the entire vehicle, not just individual parts of the drive line, is involved in starting the internal combustion engine, thus ensuring reliable starting.
Such a start/stop system preferably operates in connection with a road-condition detection system, such as an electronic stabilization system or traction control system.
The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof. | An electric drive arrangement for internal combustion engines in motor vehicles having an electric starter coupled to the internal combustion engine, and an electric generator drive connected with the internal combustion engine. The arrangement is connected to a supply battery via a semiconductor circuit arrangement, which determines the operation of the generator either in a generator mode or a motor mode. An electronic control device is used for controlling the starting operation of the internal combustion engine as a function of the signal of at least one temperature sensor with the aid of the generator operated as a motor, either alone or together with the starter. This arrangement makes it possible to achieve quicker and more comfortable starting operations in combination with lower pollutant emissions. The starting operations can be carried out reliably even at very low temperatures. | 5 |
RELATED APPLICATION
[0001] This application is a continuation in part of U.S. patent application Ser. No. 15/089,998 which was filed on Apr. 4, 2016, which is incorporated herein by reference in its entirety.
TECHNICAL FIELD
[0002] A cassette driver for a freewheel hub.
BACKGROUND
[0003] Freewheeling bicycle hubs are generally known. For example, U.S. Pat. No. 2,211,548 to Frank W. Schwinn issued on Jun. 24, 1940 is directed to a freewheeling bicycle hub configuration. Freewheeling bicycle hubs are configured to enable rotation of the pedals to drive the rotation of the wheels while also allowing the wheels to rotate independently of the rotation of the pedals. This functionality enables the pedals of the bike to be held stationary while the wheels rotate as the bike coasts. Often freewheeling hubs are configured for geared applications that include a rear cassette. A cassette driver is a portion of the hub that supports a cassette and drives the rotation of the cassette.
SUMMARY
[0004] Forward movement of a bicycle results when force is transferred from the chain or belt to a sprocket on a cassette. The cassette is splined to the cassette driver and causes the wheel of the bike to rotate when torque is applied from the cassette to the cassette driver. The cassette driver is typically made of a strong hard material such as steel to withstand the forces in parted thereon by the cassette. The present disclosure provides a hub configuration and method that enables the cassette driver to be constructed of a lighter weight material such as aluminum yet still withstand the toque applied thereto.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 is an isometric view of a hub according to the principles of the present disclosure;
[0006] FIG. 2 is a longitudinal cross-sectional view of the hub of FIG. 1 ;
[0007] FIG. 3 is a cross-sectional view of the hub along line 3 - 3 of FIG. 2 ;
[0008] FIG. 4 is a cross-sectional view of the hub along line 4 - 4 of FIG. 2 ;
[0009] FIG. 5 is an exploded assembly view of the hub of FIG. 1 ;
[0010] FIG. 6 is a first perspective view of a first embodiment of the cassette driver;
[0011] FIG. 7 is a second perspective view of the embodiment of the cassette driver of FIG. 6 ;
[0012] FIG. 8 is an assembly view of the first embodiment of the cassette driver of FIG. 6 ;
[0013] FIG. 9 is a cross sectional view of the cassette driver of FIG. 6 along line 9 - 9 of FIG. 10 ;
[0014] FIG. 10 is a cross sectional view of the cassette driver of FIG. 6 along line 10 - 10 of FIG. 9 ;
[0015] FIG. 11 is an enlarged view of a portion of FIG. 10 ;
[0016] FIG. 12 is an enlarged view of a portion of FIG. 8 ;
[0017] FIG. 13 is a first perspective view of a second embodiment of the cassette driver;
[0018] FIG. 14 is a second perspective view of the embodiment of the cassette driver of FIG. 13 ;
[0019] FIG. 15 is an assembly view of the first embodiment of the cassette driver of FIG. 13 ;
[0020] FIG. 16 is a cross sectional view of the cassette driver of FIG. 13 along line 16 - 16 of FIG. 17 ;
[0021] FIG. 17 is a cross/sectional view of the cassette driver of FIG. 13 along line 17 - 17 of FIG. 16 ;
[0022] FIG. 18 is a perspective view of a component of a hub shown in FIG. 2 according to the present disclosure;
[0023] FIG. 19 is a first perspective view of a third embodiment of the cassette driver;
[0024] FIG. 20 is a second perspective view of the cassette driver of FIG. 19 ;
[0025] FIG. 21 is a third perspective view of the cassette driver of FIG. 19 ;
[0026] FIG. 22 is an first assembly view of the cassette driver of FIG. 19 ;
[0027] FIG. 23 is a second assembly view of the cassette driver of FIG. 19 ;
[0028] FIG. 24 is a third assembly view of the cassette driver of FIG. 19 ;
[0029] FIG. 25 is an end view of the cassette driver of FIG. 19 ; and
[0030] FIG. 26 is a cross sectional view of the cassette driver of FIG. 19 along lines 26 - 26 .
DETAILED DESCRIPTION
[0031] Referring to FIG. 1 , a first embodiment of a hub according to the present disclosure is shown. In the depicted embodiment, the hub 10 includes a hub body 12 , an axle 14 , and cassette driver 16 . In the depicted embodiment, the hub 10 is configured to freewheel. In other words, a cassette driver 16 rotates with the hub body 12 when the wheel is driven by the cassette driver 16 and the cassette driver 16 rotates relative to the hub body 12 when the wheel is coasting (rotating and not being driven).
[0032] Referring to the FIGS. generally, the configuration of hub 10 is described in greater detail. In the depicted embodiment, the hub 10 is configured for use with multiple speed bicycles (e.g., road bikes, mountain bikes, etc.) that utilize an external cassette driven by a chain. In the depicted embodiment, the axle 14 is co-axially arranged within the hub body 12 . In particular, the axle 14 extends through the hub body 12 . The axle 14 includes a first end portion 18 that is positioned within the first end portion 22 of the hub body 12 and a second opposed end portion 24 that includes a portion that extend outwardly from the second end 26 of the hub body 12 . It should be appreciate that the principles of the present disclosure can alternatively be integrated into a single speed bicycle.
[0033] In the depicted embodiment, the first end portion 18 of the axle includes a shoulder 28 . The hub body 12 includes a snap ring groove 30 aligned with the shoulder 28 in a radial direction such that a snap ring 32 and the shoulder 28 cooperatively limit the axial movement of a bearing set 34 in a direction toward the second end 26 of the hub body 12 . The bearing set 34 engages an exterior surface of the axle and an interior surface of the internal cavity 56 of the hub body 12 .
[0034] In the depicted embodiment, the second end portion 24 of the axle 14 is co-axially arranged within both the hub body 12 and drive end portion 48 of the cassette driver 16 . In the depicted embodiment, a portion of the second end portion 24 of the axle 14 extends into the driven end of the cassette. In the depicted embodiment, the second end of portion 24 of the axle 14 interfaces with the cassette driver 16 via bearing set 52 .
[0035] In the depicted embodiment, the hub body 12 includes a one-piece construction. The hub body 12 is machined from a single piece of aluminum (e.g., aluminum 7075T651). The hub body 12 defines a longitudinal rotational axis A-A. The hub body 12 includes an internal cavity 56 that receives the axle 14 as well as the drive end portion 48 of the cassette driver 16 . The hub body 12 includes a first radially extending flange 58 located at the first end portion 22 of the hub body 12 , and a second radially extending flange 60 located at the second end of the hub body. Each of the radially extending flanges 58 , 60 includes a plurality of spaced apart through apertures 62 that are configured to secure spokes. Adjacent the first radially extending flange 58 is a disk brake mount flange 64 configured to support a disk of a disk brake system. The external cylindrical body of the hub body 12 tapers from the second flange 60 towards the first flange 58 . In other words, the exterior diameter of the hub body 12 adjacent the second flange 60 is greater than the exterior diameter of the hub body 12 adjacent the first flange 58 .
[0036] In the depicted embodiment, the wall thickness of the hub body 12 is greater in the portion that radially overlaps the drive end portion 48 of the cassette driver 16 as compared to the portion that does not overlap the cassette driver 16 . In the depicted embodiment, the internal cavity 56 of the second end portion 26 of the hub body defines two internal cylindrical surfaces. A first cylindrical surface 66 is defined as being a distance D 1 from the longitudinal rotational axis A-A, and a second cylindrical surface 68 is defined as being a distance D 2 from the longitudinal rotational axis A-A. In the depicted embodiment, D 2 is greater than D 1 and the first surface 66 is closer to the first end portion 22 of the hub body 12 than the second cylindrical surface 68 . In the depicted embodiment, the hub body is machined in a process whereby the hub body is not removed from a spindle until both the first and second cylindrical surfaces 66 , 68 are machined.
[0037] In the depicted embodiment, the cassette driver 16 includes an internal cavity 70 that extends from a drive end portion 48 to an opposed driven end portion 72 . The cavity receives the axle 14 , which extends into the drive end portion 48 of the cassette driver 16 . The cassette driver 16 defines a longitudinal axis of rotation that is coaxial and coincident with the axis of rotation A-A of the hub body 12 .
[0038] In the depicted embodiment, the drive end 48 of the cassette driver 16 includes a plurality of coaxial cylindrical surfaces that are positioned within the hub body 12 opposite the internal cylindrical surfaces 66 , 68 of the hub body 12 . In the depicted embodiment, an annular snap ring groove 76 is located in the first cylindrical surface 66 of the inner cavity 56 of the hub body 12 opposite an end face 78 of the drive end portion 48 of the cassette driver 16 . A first cylindrical surface 80 extends from the end face 78 of the cassette driver towards the driven end 72 of the cassette driver 16 . The first cylindrical surface 80 of the drive end 48 together with the first cylindrical surface 66 defines a first annular cavity that receives bearing set 82 that interfaces between the drive end 48 of the cassette driver 16 and the hub body 12 .
[0039] In the depicted embodiment, a second cylindrical surface 84 having a larger diameter than the first cylindrical surface 80 extends from the first cylindrical surface 80 towards the driven end 72 of the cassette driver 16 . The second cylindrical surface 84 of the drive end 48 together with the second cylindrical surface 68 defines an annular cavity that receives a sprag clutch assembly. In the depicted embodiment, the surface finish of the second cylindrical surface 84 is less than or equal to Rz of 2.5 micrometers and has a HRC hardness of at least 56 (e.g., between 58 to 62). In the depicted embodiment, the second cylindrical surface 84 has a diameter of greater than 22 mm (e.g., 29 mm). In the depicted embodiment, the second cylindrical surface is constructed of stainless steel.
[0040] In the depicted embodiment, the sprag clutch assembly includes a sprag sleeve 86 , a sprag retaining cage 88 , sprags 90 , and a tensioning band 92 . In the depicted embodiment, the surface finish of the inside surface of the sprag sleeve is less than or equal to Rz of 2.5 micrometers and the inside surface of the sprag sleeve has a HRC hardness of at least 56 (e.g., between 58 to 62). In the depicted embodiment, the sprag sleeve 86 has a diameter of less than 40 mm (e.g., 37 mm). The sprag sleeve has a height dimension that is greater than the height dimension of the sprag retaining cage 88 . The sprag sleeve 86 includes a snap ring groove that receives a snap ring that limits the axial movement of the sprag cage 88 in the axial direction towards the driven end 72 of the cassette driver.
[0041] In the depicted embodiment, the sprag sleeve is constructed of a 5210 bearing race type steel which is pressed fit/interference fit into the second cylindrical surface 68 of the hub body 12 . The construction of the sprag sleeve 98 and the hub body 12 cooperatively provide the structural stiffness needed for reliable and long lasting operation of the hub despite the strong radial forces that are generated by the sprags 90 . The sprags and sprag cages used in the depicted embodiment are currently available commercially from GMN Paul Müller Industrie GmbH & Co. KG.
[0042] In the depicted embodiment, a third cylindrical surface 94 extends coaxially from the second cylindrical surface 84 towards the driven end 72 of the cassette driver 16 . The third cylindrical surface 94 has a diameter that is greater than the diameter of the second cylindrical surface 84 . A shoulder 96 is provided on the cassette driver 16 between the third cylindrical surface 94 and the driven end 72 of the cassette driver 16 . The third cylindrical surface 94 of the drive end 48 of the cassette driver 16 together with the second cylindrical surface 68 defines a first annular cavity that receives bearing set 98 that interfaces between the drive end 48 of the cassette driver 16 and the hub body 12 . The shoulder 96 limits axial movement of the bearing set 98 in the direction towards the driven end 72 of the cassette driver 16 . An end face of the sprag sleeve 86 limits axial movement of the bearing set 98 on the axial direction towards the first cylindrical surface 80 of the drive end 48 of the cassette driver 16 . In the depicted embodiment the third cylindrical surface 94 includes an annular o-ring groove configured to receive an o-ring that seals the interface between the third cylindrical surface 94 and the bearing set 98 .
[0043] In the depicted embodiment, the internal cavity of the drive end 48 of the cassette driver includes a first cylindrical surface 100 defined by a first diameter that is greater than the diameter of the axle. The configuration results in further weight savings and strength of the cassette driver and facilitates precision manufacturing thereof.
[0044] In the depicted embodiment the configuration results in a high performance hub as it has the strength and durability to withstand intense use while also being lightweight and smooth in operation. The hub body 12 is constructed of lightweight, relatively softer aluminum material, and it is designed so that it can be manufactured with high precision as the above-referenced cylindrical surfaces 66 , 68 can be machined without detaching the hub body 12 from the chuck that holds the part during machining. The hard and robust sprag sleeve 86 is pressed into the softer aluminum. The pressing process creates a tight interference fit between the sprag sleeve 86 and cylindrical surface 68 . This interface allows the hub body 12 to work together to resist the radial forces generated by the sprags. The sprag sleeve 86 provides the hardened surface that interfaces with the sprags and also provides additional structural strength to the hub. The hub of the depicted embodiment does not require rebuilding and can operate in extreme environments including environments as cold as −50 degrees Fahrenheit.
[0045] In the depicted embodiment, the sprag cage moves with the cassette driver 16 . The tensioning member (e.g., spring) on the sprag cage biases the individual sprags against the cylindrical surface 84 of the cassette driver 16 resulting in the sprag cage being essentially tension mounted to cassette driver 16 . The internal ends of the sprags contact the second external surface 84 of the cassette driver and are biased radially outwardly against a spring and extend radially slightly beyond the periphery edge of the sprag cage. This configuration results in little and light contact between the sprags and the sprag sleeve 86 during coasting, which results in a very low friction configuration as the clutch configuration is disengaged during coasting. The non-drive forces applied between the hub body 12 and the cassette driver 16 are transferred through the bearing sets 82 , 98 that sandwich the sprag clutch assembly.
[0046] In the depicted embodiment, as soon as the driven end 72 is rotated in the drive direction at a rotational speed that exceeds the rotational speed in the drive direction of the hub body 12 , the sprags engage and lock against the sprag sleeve 86 and transfer torque from the cassette driver 16 to the hub body 12 . In the depicted embodiment, the sprag clutch assembly transfers torque to drive the hub forward. However, the sprag clutch assembly is not relied on as a bearing set support the relative rotation between the cassette driver 16 and the hub body 12 . This configuration results in a clutch configuration that immediately engages when the driven end is driven. For example, in the depicted configuration the driven end cannot be rotated relative to the hub body in the drive direction more than a small amount before it fully engages and transfers torque from the cassette driver 16 to the hub body 12 , thereby causing the hub body to rotate with the cassette driver 16 . The amount of relative rotation in the drive direction, commonly referred to as play or slop, can be less than five degrees (e.g., less than two degrees, less than one degree, or one half of a degree).
[0047] In the depicted embodiment, the driven end portion 72 is connected to the drive end portion. As discussed above, the drive end portion includes a plurality of coaxial cylindrical surfaces. In the depicted embodiment, the driven end portion 72 is formed of aluminum and includes a cylindrical body portion 110 with a plurality of axially extending raised splines 112 spaced apart on the cylindrical body portion 110 . In the depicted embodiment, adjacent splines define channels 134 therebetween. In the depicted embodiment the splines extend axially from a back wall 138 located at an end portion of the cylindrical body portion. The splines 112 are configured to engage a cassette comprised of sprockets and spacers. It should be appreciated that in alternative embodiments, the driven end portion is not integral connected to the drive end portion (e.g., they are separate components).
[0048] In the depicted embodiment, at least one of the splines is integrally formed on the surface of the cylindrical body portion 110 of the cassette driver. The at least one spline 114 includes a drive side 116 , which including a reinforcement engagement member 118 . In the depicted embodiment, at least three of the splines 114 , 120 , 122 are integrally formed on the surface of the driven end portion of the cassette driver. In the depicted embodiment, all of the splines are integrally formed on the surface of the cassette driver. However, many other alternative are also possible.
[0049] In the depicted embodiment, the at least three splines each includes a drive side 116 , 124 , 126 . Each of the drive sides of the splines includes a reinforcement engagement member 118 , 128 , 130 . The reinforcement engagement members can include a portion having a radius surface 132 (see FIG. 8 ). Additionally or alternatively, the reinforcement engagement member can include an undercut surface 136 on the drive side of the spline (see FIG. 9 ). Also, additionally or alternatively, the reinforcement member can be at least partially recessed into grooves 144 in the channel 134 between adjacent splines (see FIG. 6 ). Additionally or alternatively, the reinforcement member can include round pin receiving aperture 142 configured to receive an end of a round pin (see FIGS. 10 and 11 ). Additionally or alternatively, the reinforcement engagement member is configured to receive a reinforcement member radially and secure the reinforcement member adjacent the drive side of the spline (see FIG. 8 ). Alternatively, reinforcement engagement member is configured to receive a reinforcement member axially and secure the reinforcement member adjacent the drive side of the spline (see FIGS. 10 and 11 ). It should be appreciated that many configurations are possible.
[0050] In the depicted embodiment, the drive end portion of the cassette drive includes at least one reinforcement member 140 . In the depicted embodiment, the reinforcement member has a HRC hardness of at least at least 56 (e.g., between 58 to 62) and is engaged with the reinforcement engagement member. In the depicted embodiment, the reinforcement member is a round steel pin. In some embodiments, the round pin can be snap into engagement with the reinforcement engagement member ( FIG. 8 ). In some embodiments, the end of the reinforcement member (e.g., round pin) is pressed into an aperture 142 on the back wall 138 ( FIGS. 10 and 11 ). In the depicted embodiment, the distance from a rotational axis to a far edge of the reinforcement member does not exceed the distance from the rotational axis to a top surface of the spline (i.e., the reinforcement member is flush with or less than flush with the top of the spline).
[0051] The present disclosure also provides a method of manufacturing a hub. The method includes the step of machining a cassette driver from an aluminum body. The step of machining includes forming a drive end portion 48 and a driven end portion 72 , wherein the drive end portion includes a plurality of coaxial cylindrical surfaces and the driven end portion includes a cylindrical body portion including a plurality axially extending raised splines 112 spaced apart on the cylindrical body portion 110 , wherein the splines define a plurality of channels 134 between adjacent spline. In the depicted embodiment, at least one spline includes a drive side, the drive side including a reinforcement engagement member 140 .
[0052] The method can further include the step of securing a reinforcement member to the reinforcement engagement member. The method can further include connecting a steel insert 150 over the drive end portion of the cassette driver and machining the steel insert thereafter. The step of connecting the steel insert can include the step of pressing the steel insert into engagement with the drive end portion of the cassette driver or threading the insert thereon. The step of connecting the steel insert can include the step of axially aligning tangs with notches in the drive end of the cassette driver. The tangs once engaged with the notches prevent relative rotation of the steel insert relative to the cassette driver. In the depicted embodiments the steel insert include two tangs where are opposed and have curved exterior and interior surfaces. It should be appreciated that many other configurations are possible including for example configuration with more or less tangs (e.g., four tangs). The step of machine the steel insert after connecting it to the steel driver can be used to ensure its concentricity with the other cylindrical surface of the drive end portion 48 of the cassette driver. Many other connection methods are also possible.
[0053] Referring to FIGS. 19-26 , an alternative embodiment of the cassette driver is shown. In the depicted embodiment, the cassette driver 160 includes splines 162 , 164 each includes a longitudinal side 166 , 168 , 170 , 172 . Opposed sides of the adjacent splines includes a reinforcement engagement members. The reinforcement engagement members can include a portion having a radius surface. Additionally or alternatively, the reinforcement engagement member can include an undercut surface on the longitudinal side of the spline. It should be appreciated that many configurations are possible.
[0054] In the depicted embodiment, the drive end portion of the cassette drive includes at least one reinforcement member 180 . In the depicted embodiment, the reinforcement member has a HRC hardness of at least at least 56 (e.g., between 58 to 62) and is engaged with the reinforcement engagement member. In the depicted embodiment, the reinforcement member 180 is a steel spring clip having a circular cross section. In the depicted embodiment, the spring clip 180 includes a first leg 190 and a second leg 192 that are connected to each other via a base portion 182 . In some embodiments, the spring clip 180 is snap or axially slide into engagement with the reinforcement engagement member. In the depicted embodiment the spring force of the spring clip 180 acting outwardly against the longitudinal sides 168 , 170 of the adjacent splines 162 , 164 retains the spring clip in place against the opposed longitudinal surfaces of adjacent splines.
[0055] In the depicted embodiment, the distance from a rotational axis to a far edge of the reinforcement member does not exceed the distance from the rotational axis to a top surface of the spline (i.e., the reinforcement member is flush with or less than flush with the top of the spline).
[0056] In the depicted embodiment, the base portion 182 of the spring clip 180 is received within an undercut portion 184 of a rear shoulder 186 that creates a cavity 188 . The based portion 182 facilitates retention of the spring clip 180 . In the depicted embodiment, the spring clip 180 can be fitted onto the cassette driver prior to installing the cassette thereon. In the depicted embodiment, the spring clip is can be assembled onto the cassette drive during manufacturing thereof prior to being ship and sold.
[0057] In alternative embodiment, the spring clip could be installed onto the cassette driver during the assembling the bicycle or even after the cassette is installed on the cassette driver. In the depicted embodiment wherein the cassette driver is installed first, the spring clip can be installed with the ends retained in the cavity 188 and the based 182 located at the distal end of the cassette driver. It should be appreciated that many alternative configurations are possible.
[0058] In the depicted embodiment, the cassette drive includes three spring clips that are spaced apart on the cassette driver. In the depicted embodiment, the spring clips are retained between alternating splines. In the depicted embodiment, the spring clips are evenly spaced around the periphery of the cassette body approximately 120 degrees apart. It should be appreciated that many alternative configurations are possible.
[0059] The above specification, examples, and data provide a complete description of the manufacture and use of the composition of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended. | Forward movement of a bicycle results when force is transfer from the chain or belt to a sprocket on a cassette. The cassette is splined to the cassette driver and causes the wheel of the bike to rotate when torque is applied from the cassette to the cassette driver. The cassette driver is typically made of a strong hard material such as steel to withstand the forces in parted thereon by the cassette. The present disclosure provide a hub configuration and method that enables the cassette driver to be made with construction of a lighter weight material such as aluminum yet still withstand the toque applied thereto. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of application no. PCT/DE2009/001705, filed Dec. 3, 2009, which claims the priority of German application no. 10 2008 060 659.6, filed Dec. 8, 2008, and each of which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The invention relates to a clamping device for cylinder sleeves of a pump system, and a piston pump or plunger pump for conveying drilling fluid during drilling of boreholes, in particular in the field of oil and natural gas production. This pump system consists of a pump unit and a driving rotary drive unit. The invention further relates to the use of a clamping device in a piston pump or plunger pump.
BACKGROUND OF THE INVENTION
[0003] In the drilling of boreholes, the injection of mud, and drilling mud, respectively, into the drill string or the borehole via the pump system serves several purposes. The drilling mud is used to remove the extracted drill cuttings and spoils, and to cool and lubricate the drilling tool or its drive located at the bottom of the borehole. The pressure generated in the borehole must be equalized with the gases and liquids present in the surrounding rock.
[0004] Extremely powerful pump systems are necessary for producing the required volumetric flow, which is in the range of 3000 l/min, and for generating the required pressure, which may be as high as 500 bar.
[0005] It is standard practice to produce pressure and volumetric flow via the motion of one or more displacement elements (pistons) which provide a periodically changing work space which is sealed from the outside.
[0006] These reciprocating piston machines are characterized in that they carry out the rotating motion of the rotary drive unit via a crank mechanism in an axial motion, which moves the piston. The design of the piston as a plunger represents one variation.
[0007] The work space is formed by the cylinder sleeve and the piston which travels therein.
[0008] In its specialized use in mud pumps, the cylinder sleeve has distinctive features compared to internal combustion engines or other piston pumps, for example.
[0009] On the one hand, these cylinder sleeves are subjected to greater wear due to the pumping medium, i.e., the drilling mud, which is extremely corrosive and in particular is abrasive due to solids.
[0010] On the other hand, the pressure and volumetric flow in a mud pump may be adjusted not just by varying the rotational speed, but also by varying the piston that is used. This is achieved by inserting various pistons together with matching cylinder sleeves into the pumps.
[0011] Thus, the following requirements are imposed on the cylinder sleeve and in particular on its fastening:
[0012] Due to wear as well as adjustments and changes to the system at different pressures and volumes, the fastening must allow short setup times and a low expenditure of effort.
[0013] The cylinder sleeve must be pressed with a defined contact force against the receptacle in order to ensure the function of the seal at that location. Both components form the high-pressure partial region of the system. Leaks in this region are hazardous as well as costly.
[0014] The working environment as well as the tool that is used must be characterized in the field of the drilling industry as extremely rough and harsh. In addition, the drilling mud that is used is generally corrosive. Thus, robustness and resistance to corrosion represents another requirement of a fastening device.
[0015] According to the known prior art, cylinder sleeves are connected to the pressure-conducting part of the mud pump, referred to as the water portion, using three different systems.
[0016] The first system has a wing clamp having a conical flank, for which the contact force is produced by a cone. The contact force is produced by screws which tighten the clamp around the cylinder sleeve and the receptacle. The straight flank of the clamp lies against the cylinder sleeve, and the conical portion of the clamp lies against the receptacle on the corresponding counterpart.
[0017] The wing clamps have the major disadvantage that they are very unwieldy, and the torque may be applied to the cylinder sleeve only in a very imprecise manner using a torque wrench. In addition, this factor varies greatly as a result of the conical surface, which may become worn or soiled (oily), which has a direct influence on the contact force that is being transmitted. Installing the clamp requires a great expenditure of force and also entails a certain risk of injury. Monitoring of the contact force is not possible without retightening.
[0018] The second system has a hydraulically pretensioned bolt having a spring clamp. In this system the supporting bolts are elongated using a hydraulic pump, or the hydraulic force acts against a separate spring assembly, thus causing a deflection. The system is screwed on without torque. After the pressure is released, the required contact force present in the system is solely mechanical.
[0019] The hydraulic system offers the major advantage of a precise contact force on the cylinder sleeve, which is also referred to as a liner. However, it is disadvantageous that the cylinder sleeve and the clamping element must be lifted in two crane hoisting operations, and therefore separately. In addition, a hydraulic pump and hydraulic fluid must be present. The hydraulic components and in particular the filler are susceptible to damage, or are subject to failure and the need for frequent repairs. Due to the more complex design, the system is approximately twice as expensive as the wing clamp having a liner receptacle. Here as well, subsequent monitoring of the contact force is not possible, although there is a risk of the cylinder sleeve or liner detaching or loosening as the result of vibration from the drilling operation or the drilling mud injection process.
[0020] The third system clamps the cylinder sleeve by means of an external thread. The clamp has an element with an external thread which is placed over the cylinder sleeve and is supported on same. These elements are jointly screwed into an internal thread provided on the water portion, the required contact force being applied as a result of the pitch of the thread.
[0021] This system has a very simple mechanical design and is also easy to operate. A very uniform contact force is applied to the seal via the thread. However, the only possibility for applying torque, which, however, is very imprecise, is for the nut to be continuously struck with a hammer with the full strength of the installer. The only monitoring is leak inspection during operation. The thread is also susceptible to corrosion and damage, which together with the accompanying wear results in even greater variation of the contact force. In addition, the strength of the installer is a factor that is not easily calculated.
[0022] DE 3831909 A1 discloses a hydraulic cylinder having a cylindrical pipe and an end flange with a guide bore for a piston rod. The end flange is inserted into the cylindrical pipe using a plug-in socket. The cylindrical pipe is surrounded by a clamping ring in the region of the plug-in socket. In addition, mounting holes for accommodating clamping screws are provided, orthogonal to the longitudinal axis of the guide bore, which pass through the clamping ring, the cylindrical pipe, and the plug-in socket. An end flange/cylindrical pipe connection may thus be easily and quickly established in a modular system composed of prefabricated component parts, thus saving on manufacturing costs. This pipe/flange connection is used as a pneumatic or hydraulic motor, in particular as a drive for swivel arms in the field of robotics. In one particular design, it is described that the end flange and the plug-in socket are designed as a one-part component, and have a shared guide bore for the piston rod, sealing rings being supported in the guide bore and on the plug-in socket, resulting in proper sealing of the plug-in socket with the cylindrical pipe and the piston rod in the piston rod guide. During installation, the clamping ring is prevented from twisting by means of a centering pin on the cylindrical pipe for introduction of the mounting holes, by means of which the centering pin penetrates through the cylindrical pipe until reaching the plug-in socket. DE 3831909 A1 also discloses that a closed end flange without a guide bore for the piston rod is clamped with its plug-in socket in the other end of the cylindrical pipe in the same manner as the end flange having a guide bore for the piston rod, forming a cylinder cover and base.
[0023] The disadvantage of DE 3831909 A1 is the guiding of the piston rod in the cylinder, resulting in a statically indeterminate bearing of the piston rod, which causes increased wear on multiple wearing parts. This guiding also requires time-consuming replacement of the piston. Rapid installation and deinstallation of the piston and the cylinder sleeve is therefore not possible. In addition, the supplying of pressure media is complicated, and cannot be used in a pump having an integrated pressure media supply system. Another disadvantage is the action on the described pipe/flange connection, which is directed orthogonally with respect to the longitudinal axis of the plug-in socket.
[0024] U.S. Pat. No. 4,981,401 discloses an adjustable clamping screw having an adjustable stress level. The publication describes a screw which is introduced into an axial cavity, by means of which the stress within the component may be measured. The screw also includes a display which indicates, as soon as the screw is in use, that a preset value has been reached.
[0025] The adjustable stress-measuring bolt disclosed in U.S. Pat. No. 4,981,401 has a complicated mechanism which allows incorrect operation, and which due to the prevailing harsh conditions is not suitable for applications for conveying drilling fluid in the drilling of boreholes.
[0026] WO 2008/074428 A1 describes a fluid processing machine for compressing or conveying fluids, preferably for compressing gases to high pressures, having a linear motor, at least one cylinder, a solid piston which is axially movable in the cylinder or an axially movable liquid piston, and at least one compression space which is formed between the cylinder and the solid piston or the liquid piston. The linear motor transfers a translational driving force to the solid piston or to the liquid piston. In the described fluid processing machine, the leakage-free and lubricant-free compression and conveying of fluids at high pressures is made possible by a simple design, the solid piston being translationally driven by the traveling magnetic field of the linear motor which is generated by coils.
[0027] The cited document does not disclose a particular fastening of the cylinder of the fluid processing machine which is suitable for ensuring short setup times and a low expenditure of effort, especially in a harsh environment.
OBJECTS AND SUMMARY OF THE INVENTION
[0028] An object of the invention, therefore, is to provide a fastening device which avoids the disadvantages of the prior art and at the same time is inexpensive and easy to use, and which ensures a uniform and defined contact force on the sealing face of the cylinder sleeve, and therefore ensures its function. A further object of the invention is a piston pump or plunger pump that is suited for this purpose, and a method for installation.
[0029] The object is achieved by each of the embodiments of the clamping devices according to the invention and by each of the embodiments of the method for installing a cylinder sleeve for a piston pump or a plunger pump using a clamping device according to the invention.
[0030] The clamping device according to the invention for a cylinder sleeve of a piston pump or plunger pump includes that a cylinder sleeve receptacle and a clamping element are provided at the piston pump or plunger pump, and the sleeve or a portion of the cylinder sleeve is situated between the clamping element and the cylinder sleeve receptacle, and the clamping element and the cylinder sleeve receptacle are connected to one another by connecting apparatus, the connecting apparatus or the clamping element having devices for measuring or monitoring at least one elongation stress. Using this device, it is advantageously possible to provide the contact force uniformly on the sealing face of the cylinder sleeve, and during installation and operation of the pump to easily, reliably, and quickly measure and thus monitor the contact force or elongation stress without additional tools or measuring devices.
[0031] One preferred clamping device includes that the outer diameter of the cylinder sleeve or of a portion of the cylinder sleeve is configured to be larger than the inner diameter of the cylinder sleeve receptacle and/or of the clamping element, thus advantageously allowing the use of existing or available liners or cylinder sleeves. In addition, handling is simplified, and the design of the clamping device is optimized for use. Cylinder sleeves having an inner diameter of 3 to 10 inches, preferably 5 to 7.5 inches, are preferably used.
[0032] Another advantageous embodiment of the clamping device according to the invention provides that the clamping element is configured as part of the cylinder sleeve. Handling during installation or deinstallation may thus be improved due to the fewer number of parts.
[0033] One particularly preferred embodiment of the clamping device according to the invention includes that a guide element for the cylinder sleeve, preferably in the form of a shell, is situated on the clamping element, thus allowing improved and easier guiding and handling of the cylinder sleeve during installation and deinstallation, and providing better protection against tilting as well as damage.
[0034] Another very advantageous clamping device according to the invention includes that at least one device for the insertion and removal, preferably a hoisting eye, is situated on the clamping element and/or the guide element and/or the cylinder sleeve. This allows easier handling, in particular when the configuration is matched to the design of the device. The configuration of the insertion and removal device is optimally matched to the clamping element, the guide element, and/or the cylinder sleeve when the cylinder sleeve is oriented approximately axially with respect to the cylinder sleeve receptacle when the cylinder sleeve is lifted.
[0035] One preferred clamping device is configured in such a way that the cylinder sleeve receptacle is configured as part of the piston pump or plunger pump housing or of the valve block of the piston pump or plunger pump, resulting in the advantage of an improved and simpler design.
[0036] Another advantageous clamping device provides that the connecting apparatus in each case is composed of a fastening element, preferably a stay bolt having an axially extending borehole in the form of a shank, in which a measuring or monitoring device is situated, composed of a measuring pin which projects beyond the end face of the fastening element, and which at its inner end is preferably anchored to the shank, and which has a rotatable display element at the projecting end which is freely rotatable when the fastening element is not under stress, but which cooperates with the end face of the fastening element under pressure, and is protected against twisting when the fastening element is subjected to a predefined tensile stress or elongation stress. As the result of this preferred embodiment it is not necessary to use a tool or additional measuring devices to carry out measurement and monitoring of the elongation stress or the contact pressure on the cylinder sleeve during installation or operation of the mud pump.
[0037] One particularly advantageously configured clamping device includes that a further measuring or monitoring device, composed of a second measuring pin which projects beyond the end face of the first measuring pin, is situated on a measuring or monitoring device, the first measuring pin having an axially extending borehole in the form of a shank, and the second measuring pin at its inner end preferably being anchored to the shank of the first measuring pin or to the shank of the fastening element, and having a second rotatable display element at the projecting end which is freely rotatable when the fastening element is not under stress, but which cooperates with the end face of the first measuring pin or with the first display element under pressure, and is protected against twisting when the first measuring pin is subjected to a second predefined tensile stress. This preferred clamping device may be used to measure not only a specified minimum force, but also a maximum force, which in particular allows excessive stress on the clamping device or the cylinder sleeve to be monitored. In addition to monitoring of all fastening elements for uniform elongation stress and therefore contact force on the cylinder sleeve, this also allows monitoring of the first measuring device.
[0038] One preferred variant of the clamping device according to the invention provides that cylinder sleeves having the same outer diameter and different inner diameters may be used, thus advantageously allowing the same clamping device to be used for cylinder sleeves having different sizes of pistons or plungers, and thus to be used in different power ranges of the mud pumps.
[0039] A piston or plunger which is matched to the inner diameter of the cylinder sleeve, and with which the cylinder sleeve cooperates and which is connected to a drive, is provided in each cylinder sleeve.
[0040] In further advantageous embodiments of the clamping device according to the invention, a seal is situated between the cylinder sleeve and the wear plate or between the cylinder sleeve and the valve block. The seal for the cylinder sleeve or for the injection system is thus improved and optimized.
[0041] Also advantageous is the configuration of the clamping device according to the invention in which indentations are provided externally on the cylinder sleeve and/or internally in the cylinder sleeve receptacle. The indentations facilitate the guiding during installation and deinstallation of the cylinder sleeves, as the friction surfaces are reduced while still ensuring optimal guiding.
[0042] The piston pump or plunger pump according to the invention for use as a mud pump has at least one of the above-described advantageous clamping devices for a cylinder sleeve. The disadvantages of the mud pumps according to the prior art are thus avoided, and the conveying of drilling mud of the type described at the outset is optimized due to less complexity, in particular in the simplified installation and deinstallation of the cylinder sleeves.
[0043] The method according to the invention for installing a cylinder sleeve of a piston pump or plunger pump includes the advantageous use of one of the clamping devices described herein, resulting in simpler and more reliable installation.
[0044] One embodiment of the invention is illustrated in the drawings and described in greater detail below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0045] FIG. 1 shows a clamping device for a cylinder sleeve as part of a mud pump,
[0046] FIG. 2 shows a clamping device for a cylinder sleeve of a mud pump in an oblique view, and
[0047] FIG. 3 shows a cross section of the clamping device together with a cylinder sleeve.
DETAILED DESCRIPTION OF THE INVENTION
[0048] FIG. 1 shows a clamping device for a cylinder sleeve 5 as part of a mud pump. The cross section of the front portion of a mud pump is illustrated, a mud pump having the clamping device 5 according to the invention being represented by reference numeral 100 . Depending on the configuration, a mud pump may have multiple cylinder sleeves together with the corresponding piston or plunger.
[0049] The piston rod 36 projects from the left into the pump housing 13 , which is shown in a cutaway view in a partial illustration. The piston rod is composed of a crosshead piston rod 30 on which is mounted a baffle plate 35 which protects the portion of the pump behind the baffle plate from drilling mud discharge in the event of seal failure. A connecting element 33 is fastened to the crosshead piston rod 30 via a wing clamp. The actual piston rod 36 is connected to the connecting element 33 via a further wing clamp 34 . The actual piston 14 is fastened at its front end via the piston nut 38 . The connecting element 33 , wing clamp 34 , and piston nut 38 are used for rapid installation and deinstallation of the piston 14 and cylinder sleeve 5 .
[0050] The cylinder sleeve 5 is sealed via its sealing face 20 with respect to the valve block 25 . In the illustrated case, the seal assembly is represented as follows: a seal 19 is situated in front of the cylinder sleeve 5 , i.e., at the sealing face 20 thereof. The seal presses on a wear plate 17 which is used to keep flushed materials away from, and prevent damage to, the valve block 25 . The wear plate 17 likewise seals off the actual valve block via a seal 18 . The cylinder sleeve 5 is pressed against the seal assembly via the cylinder sleeve receptacle 2 and the fastening elements 3 , whereby the required pressure must be applied to the sealing face 20 or seal 18 . The illustrated device is shown enlarged and described in greater detail with reference to FIGS. 2 and 3 .
[0051] The piston 14 is set in translational motion by means of the crosshead piston rod 30 and the crank mechanism and rotary drive unit connected thereto. Drilling mud is drawn in and discharged by the back-and-forth motion of the piston 14 and the production of a pressure-tight space via the sealing face 37 . The fluid is drawn into the suction-side valve block 22 by means of the drilling mud flow 21 via the internally situated valve 23 . In the pre-stroke this valve 23 closes, and the fluid is pressed under pressure into the central pressure line 26 via the pressure-side valve 24 , the central pressure line interconnecting all other cylinders (not illustrated here). The fluid exits the mud pump at 27 .
[0052] Valve blocks 22 and 25 are interconnected, and together are screwed via the screw connection 28 to the front plate 1 of the mud pump housing 13 . The entire housing 13 is mounted on a stable frame or carriage 32 .
[0053] FIG. 2 shows a clamping device for cylinder sleeves of a mud pump. The cylinder sleeve receptacle 2 is mounted on the front plate 1 of a pump housing 13 , only partially illustrated, of a mud pump. The cylinder sleeve receptacle 2 accommodates the front portion of the liner or the cylinder sleeve 5 , and together with the water portion of the mud pump forms a pressure space which in the present embodiment is configured for an operating pressure of up to 350 bar. At its rear end the cylinder sleeve 5 is guided by a clamping element 4 , which on the pump side is connected to a further shell-shaped cylinder sleeve guide element 8 . This cylinder sleeve guide element 8 is fixedly connected to the clamping element 4 . For easier and faster insertion and removal of the cylinder sleeve 5 , a hoisting eye 6 is situated on the top part of the cylinder sleeve guide element 8 , by means of which the clamping element 4 , including the cylinder sleeve 5 located therein, may be more easily connected to the cylinder sleeve receptacle 2 , i.e., the valve block 25 , or the front plate 1 of the pump housing. The hoisting eye 6 may also be provided on the clamping element 4 , and is advantageously used as an installation aid for the cylinder sleeve 5 . Providing the hoisting eye 6 on the clamping element 4 or the cylinder sleeve guide element 8 in such a way that in the lifting position the cylinder sleeve 5 is in an approximately horizontal position is particularly advantageous for easier insertion, without tilting or damage, into the cylinder sleeve receptacle 2 . Multiple hoisting eyes may also be provided on the clamping element 4 and/or the cylinder sleeve guide element 8 as an installation aid.
[0054] The piston (not illustrated), which is matched to the cylinder sleeve 5 , is axially guided therein. Depending on the requirements, the inner diameter of the cylinder sleeve 5 may have different diameters. In the present embodiment, the outer diameter of the cylinder sleeve 5 , except for a clamping shoulder 7 , corresponds to the inner diameter of the clamping element 4 and to the cylinder sleeve guide element 8 . In its front side facing the valve block 25 , the cylinder sleeve 5 in a partial region (the clamping shoulder 7 ) has an outer diameter that is larger than the inner diameter of the clamping element 4 and of the cylinder sleeve guide element 8 , and of the inner diameter of the cylinder sleeve receptacle 2 . By means of the stay bolts as fastening elements 3 , the portion of the cylinder sleeve 5 having the larger outer diameter is fixedly clamped between the clamping element 4 and, in the present preferred embodiment, the cylinder sleeve guide element 8 on the one side, and the cylinder sleeve receptacles 2 on the other side. Four stay bolts are used in this embodiment. However, three, or more than four, connecting elements 3 may also be used. The stay bolts are screwed to the cylinder sleeve receptacle 2 . On their side opposite from the cylinder sleeve receptacle 2 the fastening elements 3 , i.e., stay bolts, have a head 11 of the fastening element 3 , at the end face 10 of which a measuring device 9 projects. The measuring device 9 is a device for measuring or monitoring at least one elongation stress. The elongation measurement is used in particular for monitoring the contact force of the sealing face on the cylinder sleeve 5 at the pressure-conducting element of the mud pump—in the current example, the wear plate 17 or the valve block 25 . Such fastening elements 3 having a torque or stress measuring device 9 at the head are generally also referred to as “RotaBolts.”
[0055] The portion of the cylinder sleeve 5 having a larger outer diameter than the remainder of the cylinder sleeve 5 is referred to in the present case as the clamping shoulder 7 of the cylinder sleeve 5 . The clamping shoulder 7 is designed in such a way that it is to be securely and tightly clamped between the cylinder sleeve receptacle 2 and the clamping element 4 .
[0056] FIG. 3 illustrates a cross section of the clamping device in cooperation with the cylinder sleeve. The manner in which the cylinder sleeve 5 is pressed against the valve block 25 by means of the clamping shoulder 7 and the clamping element 4 is readily apparent. As illustrated in the present example, the cylinder sleeve 5 and/or the cylinder sleeve receptacle 2 may have indentations on the fitting surface 15 which advantageously reduce the friction surface and allow easier guiding during insertion and removal of the cylinder sleeve 5 .
[0057] To produce a pressure-tight space between the two elements, namely, the valve block 25 and the cylinder sleeve 5 , in the present example the seal elements have the following arrangement. At the sealing face 20 the cylinder sleeve 5 presses against the wear plate 17 , thus compressing the seal 19 .
[0058] The cylinder sleeve 5 is guided on one side in the shell 8 of the clamping element 4 , and on the other side is guided in the cylinder sleeve receptacle 2 . The cylinder sleeve receptacle is fixedly connected to the valve block 25 via the screw connection 12 , and for deinstallation may be removed via the extraction holes 16 .
[0059] The valve block 25 is also connected to the front plate 1 of the mud pump via the screw connection 28 .
[0060] While this invention has been described as having a preferred design, it is understood that it is capable of further modifications, and uses and/or adaptations of the invention and following in general the principle of the invention and including such departures from the present disclosure as come within the known or customary practice in the art to which the invention pertains, and as may be applied to the central features hereinbefore set forth, and fall within the scope of the invention.
LIST OF REFERENCE NUMERALS
[0000]
1 . Front plate of pump housing
2 . Cylinder sleeve receptacle
3 . Fastening element together with measuring device
4 . Clamping element
5 . Cylinder sleeve
6 . Hoisting eye
7 . Clamping shoulder of cylinder sleeve 5
8 . Guide element (shell shaped)
9 . Measuring device on fastening element 3
10 . End face on the head 11 of fastening element 3
11 . Head of fastening element 3
12 . Screw connection of cylinder sleeve receptacle 2 to valve block 25
13 . Mud pump housing
14 . Piston
15 . Fitting surface between cylinder sleeve 5 and receptacle 2
16 . Extraction holes for cylinder sleeve receptacle 2
17 . Wear plate between cylinder sleeve 5 and valve block 25
18 . Sealing element between wear plate 17 and valve block 25
19 . Sealing element between cylinder sleeve 5 and wear plate 17
20 . Sealing face of cylinder sleeve 5
21 . Drilling mud flow
22 . Valve block (suction side)
23 . Valve (suction side)
24 . Valve (pressure side)
25 . Valve block (pressure side)
26 . Central pressure line between the valve blocks
27 . Pressurized discharge exit
28 . Screw connection of front plate 1 to valve block 25
29 . Opening to cylinder sleeve chamber
30 . Crosshead piston rod
31 . Tool support shoulders for deinstallation
32 . Fastening frame for mud pump
33 . Connecting element between crosshead piston rod 30 and piston rod 36
34 . Wing clamp for connecting element 33 and piston rod 36
35 . Baffle plate for drilling mud discharge
36 . Piston rod
37 . Sealing face of piston 14 with respect to cylinder sleeve 5
38 . Piston nut
39 . Valve cover
100 . Mud pump | Clamping device for cylinder sleeves of a pump system, and a piston pump or plunger pump for conveying drilling fluid during drilling of boreholes, particularly in the field of oil and natural gas production, and its use. Pump system includes a pump unit and a driving rotary drive unit. Clamping device for cylinder sleeve of a piston pump or plunger pump includes a cylinder sleeve receptacle, a clamping element provided at the pump, and cylinder sleeve or a portion of the cylinder sleeve provided between the clamping element and the cylinder sleeve receptacle, Clamping element and cylinder sleeve receptacle are connected by a connecting apparatus. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates generally to side-release buckles of the type having a female receptacle member and a mating male latch member which are releasably lockable together. More particularly, the invention relates to such a side-release buckle wherein the female receptacle member includes a tooth which is adapted to engage with a centrally aligned groove and latch in a leg of the male latch member, whereby the latch and tooth provide a resistance force in opposition to and in central alignment with a loading force acting to separate the male latch member from the female receptacle member.
2. Description of Related Art
Assorted two-piece buckles are known in the art. These buckles typically include a female receptacle or socket member which is engageable with a male latch or plug member. One or both of the members adjustably or fixedly holds a strap or belt around crossbars or the like. One particularly common form of a two-piece buckle is one in which the plug member includes a pair of legs which, when inserted into the socket member, flex inwardly and slide past opposing stop members (e.g., latches) in the socket until they snap fit into respective side openings in the socket. The stop members are typically inwardly projecting surfaces of the socket member around the periphery of the opening which engage with shoulders defined on the outside edges of the legs of the male member. The two buckle pieces are unlocked and disengaged by squeezing the legs of the male member through the openings in the female member between the thumb and forefinger, thereby freeing the shoulders defined in the legs from the respective stop members in the female member and allowing the two buckle pieces to become separated.
An example of such a buckle is disclosed in U.S. Pat. No. 4,150,464, and a basic configuration of this type of buckle is illustrated in FIGS. 3 and 4. It can be seen that the female member defines apertures in opposing side walls thereof for engagement with shoulders of the latch arms belonging to the male member. The shoulders are positioned on the outside side surfaces of the latch arms and engage the stop members which project inwardly from the side walls of the female member. However, it has been recognized that with this arrangement, the buckle is susceptible to failure during heavy loading for the following reasons. The load in the latch arms which urges removal of the latch arms from the female member is ordinarily directed along the longitudinal axis or center line X of each latch arm. However, the line Y, which represents the location of the latch resistance or engagement force opposing the load, is offset from center line X because it is directed between the side walls of the female member and the shoulders on the outside side surfaces of the latch arms. Accordingly, it has been recognized that during loading on the buckle, a torque develops between the latch arms and the female member which tends to cause inward rotation of the latch arms in the direction of arrow Z (see FIG. 4), and consequently release of the buckle (see also U.S. Pat. No. 5,222,279 (col. 1, 1. 43-48).
U.S. Pat. No. 5,222,279 proposes a solution to this problem. In accordance with this patent, the shoulders on the latch arms are relocated from the outside side surfaces thereof to the top and bottom surface of each arm (see FIGS. 1 and 2). Thus, each arm has a pair of shoulders on opposite top and bottom sides of the arm (i.e., the top and bottom of the arm), and the shoulders are on opposite sides of the longitudinal axis or central line of each latch arm. The shoulders engage corresponding stop members in the female member of the buckle. Since the shoulders are no longer positioned on the outside side surfaces of the latch arms, and since the shoulders are aligned, in one direction, with the central or longitudinal axis of the latch arms, the latch resistance force which opposes the load on the buckle is aligned, in one direction, with the load force.
However, since the shoulders on the latch arms of the buckle described in U.S. Pat. No. 5,222,279 are located on opposite sides (i.e., the top and bottom) of the longitudinal axis of the latch arm, the latch resistance force opposing the load is merely aligned in one direction (i.e., in the "width" direction) with the load force. The latch resistance force is not aligned with the longitudinal or central axis of the latch arms in all planes and directions.
Published U.K. Patent Application GB 2 262 962 also proposes a solution to the problem of misalignment of the latch resistance or engagement force with the load force which occurs in the prior art buckles wherein the shoulders are defined in the outside side surfaces of the latch arms. The proposed solution is similar to the one described in U.S. Pat. No. 5,222,279 in that it involves the provision of engagement shoulders on the top and bottom surfaces of the latch arms. The engagement shoulders or surfaces on the latch arms are grooves which are adapted to mate with corresponding ridges in the female member of the buckle. The engagement or latch resistance force between the grooves on the latch arms and the ridges in the female member is aligned, in one direction, with the longitudinal or center axis of the latch arms. However, like the buckle described in U.S. Pat. No. 5,222,279, the latch resistance force is not aligned along the longitudinal axis of the latch arms in all directions, but rather it is located on opposite (i.e., top and bottom) surfaces of the latch arms.
It would therefore be desirable to provide a side-release buckle wherein the engagement force between the male and female members, which opposes the load force, is aligned in all directions with the longitudinal or central axis of the latch arms belonging to the male member, rather than being aligned merely in one direction, in order to further improve the locking strength of the buckle.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the invention to provide a side-release buckle wherein the engagement force between the male and female members of the buckle, opposing the load force, is aligned in all directions with the longitudinal or central axis of the arms belonging to the male member of the buckle.
It is a further object of the invention to provide a side-release buckle having an improved locking mechanism as compared to the side-release buckles of the prior art.
These and other objects of the invention, which will become apparent from the following Detailed Description of the Invention, are achieved by a side-release buckle having the following structure.
The invention is a side-release type buckle having a female socket member which defines a socket or receptacle therein having an open end. A male latch or plug member having at least one arm for insertion into the socket through the open end of the female member is provided. The plug member includes at least one resiliently flexible arm projecting from a base thereof which is adapted to be inserted into the socket member. A region at or near the distal end of the arm(s) defines a rounded protrusion on the outside side surface of the arm. The rounded protrusion defines a groove along a center line thereof, the groove being aligned in one direction with the longitudinal axis of the arm. The groove includes a proximal notch or recess which is deeper than the remaining distal portion of the groove so as to define a shoulder in the arm located on the central, longitudinal axis of the arm.
The female socket member includes at least one aperture defined through a side wall thereof for exposing the rounded protrusion of the arm belonging to the plug member, when the plug member is fully inserted into the socket member. An inner surface of the side wall of the socket member, adjacent to or near the distal end of the aperture defined in the side wall, includes an inwardly projecting tooth which is adapted to engage with the shoulder defined in the arm of the male member as follows. The tooth includes a ramp surface on its distal side to permit the groove defined in the rounded protrusion of the arm belonging to the male member to slide over it. As the male member is inserted into the socket, its resilient arm will flex inwardly as the groove slides over the ramp surface of the tooth until the shoulder defined in the arm clears the proximal side of the tooth. At this point, the arm will snap back outward through the aperture in the side wall of the socket member. In this position, the proximal face of the tooth will abut the shoulder defined in the arm of the plug member thereby locking the two buckle pieces together. Since the tooth and the shoulder are now aligned along the central, longitudinal axis of the arm, it will be appreciated that the engagement force, which opposes the load force on the buckle, is aligned along the same axis with the load force so that the two forces oppose each other by 180°.
If desired, the aperture defined in the side wall of the socket member may also include a conventional stop member at the distal end of the opening and the rounded protrusion of the arm may also include a conventional shoulder defined along its outside side surface for engagement with the stop member for additional holding strength.
To separate the two buckle pieces, the rounded protrusion of the arm is merely pushed into the aperture in the side wall of the socket until the shoulder clears the tooth. The resilient force now supplied by the arm will urge the plug member to spring out of the socket member, thereby disengaging the buckle pieces.
In another embodiment, the disengagement means (e.g., the rounded protrusion belonging to the arm which can be pushed into the aperture in the side wall of the socket) is provided on the socket member rather than the plug member. In this embodiment, the plug member still includes a centrally disposed groove aligned along the center line of the arm and a shoulder defined in said groove, however, the arm does not include any protrusion portion which projects out of the side wall of the socket member. Instead, the socket member includes at least one resiliently flexible arm in its side wall which can be pushed inward through an aperture in the side wall to force the arm belonging to the plug member inward and away from the tooth. The tooth which projects from an inner surface of the side wall of the socket member engages and disengages from the shoulder defined in the arm belonging to the plug member as in the other embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS
Various other objects, features and advantages of the present invention will be more fully appreciated from the following detailed description of the preferred embodiments, when considered in connection with the accompanying drawings, in which like reference characters designate like or corresponding parts throughout the several views, and wherein:
FIG. 1 is an exploded perspective view of a side release type buckle of the prior art showing the male and female members separated.
FIG. 2 is an isolated enlarged side elevational view of the locking mechanism of the prior art buckle of FIG. 1 wherein the male and female members are coupled.
FIG. 3 is an exploded perspective view of another prior art buckle showing the female and male members separated.
FIG. 4 is an enlarged isolated view of a portion of the prior art buckle of FIG. 3, illustrating the engagement and failure positions between the male and female members.
FIG. 5 is an exploded perspective view of a first embodiment of a buckle in accordance with the invention.
FIG. 6 is an elevational view of a side of the buckle of FIG. 5 in the coupled or locked state which is partially cut away to expose the locking mechanism.
FIG. 7 is a bottom cross-sectional view of the buckle of FIG. 6 taken along the line 7--7.
FIG. 8 is a cross-sectional view of the of the buckle illustrated in FIG. 7 taken along the line 8--8.
FIG. 9 is an isolated view of the buckle illustrated in FIG. 7 showing disengagement of the locking mechanism.
FIG. 10 is an exploded perspective view of a buckle in accordance with a second embodiment of the invention.
FIG. 11 is a side elevational view of the buckle of FIG. 10 in the coupled or locked state which is partially broken away to expose the engaged locking mechanism.
FIG. 12 is a bottom cross-sectional view of the buckle illustrated in FIG. 11 taken along the line 12--12.
FIG. 13 is a staggered cross-sectional view of the buckle illustrated in FIG. 12 taken along the staggered line 13--13.
FIG. 14 is a side isolated cross-sectional view of the locking mechanism of the buckle illustrated in FIG. 11.
FIG. 15 is an isolated bottom cross-sectional view of the buckle of FIG. 12 showing disengagement or release of the locking mechanism.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIGS. 5-9, a buckle in accordance with a first embodiment of the invention is designated generally by the reference numeral 1. The buckle 1 is typically used to connect free-ends of straps 2 and 3 (see FIG. 6). The buckle 1 is generally comprised of two pieces, a female socket member 4 and a complementary male plug member 5.
The buckle 1 is preferably molded from some type of plastic or resin, but any suitable material known in the art for molding or machining side-release type buckles may be used.
The socket member 4 includes a single cross bar 6 at its proximal end. The strap 2 is looped around the cross bar 6 and then stitched to itself to permanently secure the strap to the cross bar. The male plug member 5 includes a pair of cross bars 8 and 9 at its proximal end which can receive the strap 3 in a well known manner such that the strap 3 is adjustable, for example, as described in my U.S. Pat. No. 5,216,786. Alternatively, the pair of cross bars may be provided on the female socket member and the single cross bar may be provided on the male member, or both the male and the female members may include a single cross bar, in which event both strap 2 and strap 3 would not be adjustable.
The socket member 4 preferably has a flat rectangular tubular cross-sectional configuration as illustrated in FIG. 5, having a substantially rectangular shaped interior cavity 10 (see FIG. 8). The cavity 10 is defined as the area between a top wall 11, an opposing bottom wall 12 and a pair of side walls 13 and 14, each of which connects the top wall to the bottom wall at the side edges thereof. The top and bottom walls 11 and 12 are typically much wider than the side walls 13 and 14, as illustrated, so that the socket member has a substantially flat or rectangular shape.
As will be explained in detail below, the male plug member 5 is received and releasably locked within the cavity 10 of the female socket member 4 via latch means which are associated with the male member. The female socket member 4 includes an aperture 15 defined in each side wall 13 and 14 thereof. The apertures 15 cooperate with the latch means associated with the male plug member 5 to retain and lock the plug member 5 within the socket member 4. The apertures 15 also enable the user to access the male plug member 5 from the exterior of the socket member 4 to allow for release of the two buckle pieces (see FIGS. 7 and 9). Each aperture 15 extends at least through a portion of the top and bottom walls 11 and 12, as well as through the opposing side walls 13 and 14, to form a side-release type buckle 1. However, as will be appreciated by those skilled in the art, the particular shape, location, position and number of apertures 15 can vary so long as the side-release buckle 1 functions substantially as described herein.
To facilitate in guiding the male plug member 5 as it is inserted into the cavity 10 of the socket member 4, the inner surfaces of the top and bottom walls 11 and 12 of the socket member 4 may be formed with a pair of inwardly projecting guides 16 (see FIG. 8) which extend from the distal end 17 (i.e., the open end) of the socket member toward the proximal end near the cross bar 6. The area between the guides 16 will receive a distally projecting and centrally disposed guide bar 18 on the male plug member 5 as will be described hereinafter.
To retain and lock the plug member 5 in the socket member 4, the inner surface of each side wall 13 and 14 of the socket 4 includes an inwardly projecting tooth 19. Each tooth 19 is positioned along the inner surface of the side wall 13 or 14 to which it belongs substantially along the central longitudinal axis of the side wall, which is the midway line between the top wall 11 and the bottom wall 12. Each tooth 19 includes a proximal surface 20 (see FIG. 9) which projects inwardly from the inner surface of its associated side wall toward the interior of the cavity 10. Each tooth 19 also includes a ramped surface 21 which extends from a tip in the distal direction toward the inner surface of the side wall to which the tooth is attached to eventually merge with the inner surface of said side wall. Each tooth 19 is positioned adjacent to or near the distal end of the aperture 15 in the side wall 13 or 14.
The male plug member 5 includes a proximal base portion 22 which is attached to two resiliently flexible arm members 23. Arm members 23 project in the distal direction from the base 22. The pair of arm members 23 have a predetermined length, and run along opposite sides of the male plug member 5. Guide bar 18 (if provided) also projects in the distal direction from the base 22.
Each arm member 23 includes a first proximal end 24 which is attached to the base portion 22 and a second opposite distal end 25. To facilitate access to the user of the buckle, the distal end 25 of each arm member 23 is formed with a rounded protrusion or bulbous region 26 on its outer side surface. A groove 27 is cut into the outside side surface of the protrusion 26 from the distal end 25 (see FIGS. 5 and 6). The groove 27 is aligned in one direction along the central longitudinal axis of the arm member 23 (i.e., the midway line between the top surface 28 and the bottom surface 29 of each arm member) (see FIG. 6). The groove 27 is of a size to enable it to receive the tooth 19 when the plug member 5 is inserted into the cavity 10 of the socket member 4.
Each groove 27 is formed with a notch 30 (see FIG. 9) at some point proximal to the distal end 25 of the arm 23. The notch 30 is deeper than the groove 27 so as to define a locking shoulder in the arm with which the locking surface 20 of the tooth 19 is adapted to engage. The notch 30 should be positioned along the arm 23 at a predetermined point such that it engages the tooth 19 when the plug member 5 is fully inserted into the socket member 4. Preferably, the notch 30 is deep enough to extend through the central longitudinal axis of the arm member 23 to which it belongs. The notch 30 may go deep enough to extend completely through the arm 23 all the way to the inner side surface of the arm to form a hole. The notch 30 may also be extended proximally along the outside side surface of arm 23 all the way to the proximal end 24 to define a channel (or slot if the notch goes all the way through the arm to the inner side surface thereof), if desired for ease of molding. Thus, it is to be understood that the term "notch" used herein means any recessed area defining a shoulder, including a depression, a hole, a channel, a slot, etc. . . .
To releasably connect the male plug member 5 to the socket member 4, the distal end 25 of each arm member 23 is first inserted within the cavity 10, with the guide bar 18 being positioned within the guides 16 of the socket member 4. Upon continued insertion, the distal ends 25 and grooves 27 will contact the ramped surface 21 of each tooth 19, and each arm member 23 will be flexed toward the interior of the cavity 10. Further insertion will result in the ramped surface 21 to ride along the groove 27 until the proximal locking surface 20 of the tooth 19 reaches the notch 30, at which point each arm member 23 snaps outward with respect to the cavity 10 so that the tooth 19 sits inside the notch 30. In this position, the proximal locking surface 20 of the tooth 19 will abut the shoulder defined by the notch 30 to lock the plug member 5 to the socket member 4 (see FIGS. 6 and 7). It can be seen from FIG. 7 that in this locked position, the rounded protrusions 26 extend out from the sides of the socket member through the apertures 15.
As FIG. 9 illustrates, to release the male plug member from the cavity 10, a user presses the protrusions 26 into the cavity to flex the arm members 23 inward with respect to the cavity 10. Once the shoulders defined by the notches 30 clear the locking surfaces 20 of the teeth 19, the male plug member can be removed from the socket member. The resilient force exerted by the arm members so flexed inwardly will facilitate the "springing out" of the plug member from the cavity 10. In addition, the rounded outside side surfaces of the protrusions 26 will also facilitate easy separation of the plug member 5 from the socket member 4.
As described earlier, the prior art buckle 110 illustrated in FIGS. 3 and 4 includes shoulders 112 located on the outer side edges of the arm members 114 of the male latch member. Accordingly, the force provided under load is centered along line "X", which runs through the longitudinal center line or axis of each arm member 114, while the engagement or retaining force provided by the shoulders 112 is centered along line "Y", which runs through the shoulders 112 and is slightly offset from the line "X". The offset between lines "X" and "Y" produces a torque on the arm members 114 substantially in the direction of arrow "Z" in FIG. 4 causing premature unlocking of the arm members 112 from the stop members 116 and/or release of the buckle 110.
As described earlier, the buckle 210 of U.S. Pat. No. 5,222,279 (illustrated in FIGS. 1 and 2) does not provide a complete solution to this problem, because the shoulders 212 which supply the engagement or retaining force are aligned with the longitudinal axis "X" of the arm member only in one direction (i.e., referred to in the prior art patent as the "width" direction). The retaining force is not aligned in all directions because the shoulders are located on the top and bottom of each arm member (see FIGS. 1 and 2) (i.e., on opposite sides of the central longitudinal axis in the other direction).
In contrast, as FIGS. 5, 6 and 8 illustrate, the buckle 1 of the present invention provides alignment of both the load force through the longitudinal center line or axis of each arm member 23 and the engagement or retaining force provided by the engagement of the shoulder in the notch 30 with the proximal surface 20 of tooth 19. This alignment of forces in all directions is possible due to the central positioning of the notch 30 along the longitudinal axis of the arm member 23 midway between the top surface 28 and the bottom surface 29, see FIG. 6, as well as midway between the outer side surface and the inner side surface) and the corresponding central positioning of the tooth 19 along the midway line of the side wall between the top wall 11 and bottom wall 12 of the socket member 4.
For additional strength, the buckle 1 of this first embodiment of the invention may also be provided with a conventional releasable locking means for two-piece side release buckles. For this purpose, the proximal end of each of the rounded protrusions 26 defines a conventional shoulder 31 (see FIG. 5) on the outer side surface of each arm member 23. A complementary stop member 32 is provided at the distal end of each aperture 15 in the socket member 4. It can be seen that each stop member 32 is simply an extension of the side wall 13 or 14 which projects inwardly toward the cavity 10. As known in the art, the locations of the shoulder 31 and stop member 32, as well as the dimensions of the various features of the buckle are predetermined such that shoulders 31 abut against stop members 32 when the arm members 23 are fully inserted into the socket member 4. Of course, in this locked position, the proximal locking surface 20 of the tooth 19 will abut against the shoulder defined by notch 30. Unlocking of the buckle occurs in the same manner described above - - - the user merely squeezes the rounded protrusions 26 toward the interior of the cavity 10 until the shoulders 31 clear the stop members 32 and the notches 30 clear the teeth 19, whereupon the resilient force exerted by the inwardly flexed legs, in cooperation with the rounded surfaces of the protrusions 26, will urge the plug member to spring out of the cavity 10.
It can be seen that in the first embodiment of the invention, the user must have access to the rounded protrusions 26 through the apertures 15 in order to release the buckle and separate the two buckle pieces. In a second embodiment of the invention, the disengagement means is provided exclusively on the socket member 4 rather than on the plug member 5. The second embodiment is illustrated in FIGS. 10-15 in which like reference numerals designate like or corresponding parts which are present in the first embodiment.
It can be seen that in the second embodiment, no portion of the arm members 23 project out from the openings 15 in the side walls 13 and 14 of the socket member 4. Rather, the socket member 4 includes a pair of pivotable releasing members 33 formed in opposite sides 13 and 14, respectively. Each releasing member 33 includes a stem portion 34 and a head portion 35. The distal end of the stem portion 34 is attached to side wall 13 or 14 as the case may be, and the releasing member 33 is pivotable about this point of attachment through aperture 15 in each side wall. The head 35 of each releasing member 33 includes an inwardly projecting finger 36 which projects inwardly toward cavity 10.
A bridge 37 extends across each aperture 15 between the top wall 11 and the bottom wall 12 of the socket member 4. Bridge 37 is positioned inwardly of releasing member 33 so that releasing member 33 remains pivotable over the bridge 37. The purpose of the bridge is to support tooth 19 which, as will be described below, is adapted to lock into the notch 30 (see FIG. 15) of arm member 23 when the plug member 5 is fully inserted into the socket member 4. As in the previous embodiment, the tooth 19 includes a locking surface 20 on its proximal face and a ramped surface 21 on its distal face.
As in the first embodiment, the outer side surface of each arm member 23 has a centrally disposed groove 27 extending from the distal end 25 of the arm in a proximal direction toward a notch 30. The groove 27 lies along the midway line on the outer side surface between the top surface 28 and the bottom surface 29 (see FIGS. 11 and 14). The notch 30 is deeper than the groove 27, and preferably is deep enough to extend through the central longitudinal axis of the arm member 23 (i.e., the midway line between the inner side surface and the outer side surface, as well as the midway line between the top surface 28 and the bottom surface 29 of arm member 23). The groove 27 is adapted to slidably receive the ramped surface 21 of the tooth 19 in the socket member 4. As in the previous embodiment, the notch 30 defines a shoulder 38 (see FIG. 15) inside the arm member 23 which is adapted to engage with the locking surface 20 on the tooth 19.
To releasably connect the male plug member 5 to the female socket member 4, the distal end 25 of each arm member 23 is first inserted within the cavity 10 through the opening in the distal end of the socket member 4. Upon continued insertion, the distal ends 25 and grooves 27 will contact the ramped surfaces 21 of each tooth 19, and each arm member 23 will be flexed toward the interior of cavity 10. Further insertion causes the ramped surfaces 21 to ride along the grooves 27 until the notch 30 receives the tooth 19. At this point, each arm member 23 snaps outward with respect to the cavity 10 and, as FIGS. 12 and 14 illustrate, the shoulder defined by the notch 30 is seated against the locking surface 20 of tooth 19. At this point, the finger 36 of each releasing member 33 just rests against each arm member 23, or rests only a very short distance from the arm member as depicted in FIG. 12.
As FIG. 15 illustrates, to release the male plug member 5 from the socket member 4, the user simply squeezes the heads 35 of the opposing releasing members 33 toward the interior of cavity 10. This causes each finger 36 to engage each arm member 23 to cause the arm members 23 to flex inwardly toward the center of cavity 10. Eventually, the shoulders 38 defined by notches 30 will clear the locking surfaces 20 of teeth 19 thereby freeing the arm members 23 from teeth 19. The resilient force now exerted by the inwardly flexed arm members 23, in cooperation with the ramped surfaces 21, will urge the plug member 5 to spring out of the cavity 10.
As in the first embodiment, since the grooves 27 are disposed along the midway line between the top and bottom surfaces 28 and 29 of the arm members 23, and since the shoulders defined by the notches 30 extend toward the central longitudinal axis of the arm members 23, the engagement or retaining force provided by engagement of the notches 30 with the teeth 19 runs through the central longitudinal axis of each arm member 23 and is aligned with the load force tending to separate the coupled buckle pieces.
In addition to the stop member provided by shoulder 38 in notch 30, each arm member 23 may have a pair of wings 39 at the distal end 25 thereof (see FIGS. 11 and 14). The wings 39 define shoulders 40 on the proximal face thereof, the shoulders 40 being situated on opposite top and bottom sides of the arms 23. The shoulders are adapted to abut against retaining members 41 which project from the inner surfaces of the top 11 and bottom 12 walls of the socket member 4 to lock the plug member 4 in the socket. To disengage this locking mechanism, the heads 35 of the releasing members are squeezed inwardly toward the center of cavity 10 to force the wings 39 clear of the retaining members 41. The structure and operation of this optional additional locking mechanism is described more fully in my copending application Ser. No. 08/286,610 filed on Aug. 5, 1994 which is incorporated herein by reference.
In the preceding specification, the invention has been described with reference to specific exemplary embodiments thereof. It will, however, be evident that various modifications and changes may be made thereunto without departing from the broader spirit and scope of the invention as set forth in the claims which follow. The specification and drawings are accordingly to be regarded in an illustrative rather than a restrictive sense. | A side release buckle having an improved locking mechanism includes a male plug member and a female socket member. The plug member has a pair of resiliently flexible arm members. Each arm member includes a recess or notch disposed along the central longitudinal axis of the arm member which is adapted to engage a tooth arranged in a corresponding position in the socket member when the plug member is fully inserted into the socket member. Since the engagement or retaining force between the recess and the tooth lies along the central longitudinal axis of the arm members, this force directly opposes the load force on the buckle which acts to separate the two buckle pieces. Because of the proper positioning and arrangement of the recess and the tooth, the load force and the retaining force are aligned along the same axis, thereby providing increased holding power. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
Clutches are commonly used in various mechanical applications where it is desired optionally to connect or disconnect a rotating input member with a rotatable output load. One type of clutch utilized centrifugal force generated by rotation of the input member to move frictional members radially outwardly and into engagement with the output load, thereby to achieve a frictional connection between the two parts.
This invention relates to a centrifugal clutch and, more particularly, to electromagnetic means for interrupting a frictional driving connection between an input driving member and an output driven member at any time it is desired, regardless of speed of rotation of the clutched parts.
2. Description of the Prior Art
Various structures have been previously employed in clutch assemblies to effect a driving connection between an input member, usually a drive shaft, and an output member or load. U.S. Pat. No. 1,782,513 to Roos describes a centrifugal clutch in which the input member carries weighted pivot arms. Normally, coil springs urge the arms into contact with an output member, but at a predetermined rate of rotation of the input member, centrifugal force throws the weighted ends of the arms outwardly to interrupt the two frictionally joined parts.
U.S. Pat. No. 2,400,586 to Zimmermann describes a mercury actuated centrifugal clutch in which radially moveable members are forced into driving engagement with a driven member by the pressure of mercury contained in an expansible driving member chamber. This action occurs atuomatically upon rotation of the driving member.
The clutches of the two foregoing patents lack the advantages of electro-actuation or electro-deactuation of a driving frictional connection and are subject to still other shortcomings. As an example, making or breaking a driving connection between input and output members depends wholly upon the speed of rotation a certain member, usually the driving member. Further, as the springs of the Roos patent weaken, the desired moment of declutching is unavoidably varied. In the mercury-actuated clutch of the type described in the Zimmermann patent, difficulties arise in introducing the mercury into suitable container as well as sealing the container and preventing it from subsequent rupture, especially under the inertia and fluid pressure developed by the relatively heavy mercury under centrifugal force.
An electromagnetic clutch is disclosed by U.S. Pat. No. 2,606,638 to Russell which, however, is not of the centrifugal type. The magnetic circuit of this clutch includes a pair of radially disposed discs which are placed in parallel, close proximity. One disc is fixed to an input member, and the other disc is fixed to the output member. The flux of the electromagnetic circuit locks the two discs together. In this case, therefore, the electromagnetic circuit is used to effect the actual coupling of the two parts rather than their disconnection. Also, since this type of clutch is not of the centrifugal type, it has no components responsive to centrifugal force.
SUMMARY OF THE INVENTION
The principal object of the present invention is to provide an improved centrifugal clutch in which electromagnetic means disconnects the driving and driven components. More particularly, the present clutch couples a rotatable input member to a rotatable output member by centrifugal force only, that is, in the absence of other electrical or hydraulically-actuated assits, and then disengages the indicated parts at any speed and any load value desired by electromagnetic power. Thus, centrifugal force moves a friction member outwardly to generate the friction forces for torque transmission, while an electromagnetic structure built into the clutch assembly retracts the frictional member upon energization to break the driving connection.
In one form, the clutch assembly includes rotatable input and output members, the latter being circumferentially disposed about the former. The input member carries friction means mounted for radial movement toward and away from the output member. The friction means has a magnetic pole and, in response to rotation of the input member, moves radially outwardly and frictionally contacts the output member to unite the two in joint rotation. An electromagnetic coil that is stationery with respect to the two rotatable members is stationed between the input member and its friction means to attract the friction means magnetically toward the coil when it is energized and thereby interrupt the joint rotation of the input and output members.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings:
FIG. 1 is an offset radial section of the present clutch assembly taken on the line 1--1 of FIG. 3;
FIG. 2 is a section of FIG. 1 on the plane of the line 2--2 with the driven drum member removed, and with parts broken away to illustrate a friction shoe; and
FIG. 3 is a section of FIG. 1 on the plane of the line 3--3.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A presently preferred embodiment includes a driving member having an input, rotatable shaft provided with a plurality of friction shoes mounted circumferentially about the shaft. Each shoe has a magnetic pole and is adapted for radial movement away from the shaft in response to its rotation. An electromagnetic coil disposed between the shoes and the rotatable shaft is held against rotation with the shaft. A driven output member disposed circumferentially about the driving member and its friction shoes is mounted on the same rotatable shaft of the input member but is free to rotate relatively to the shaft. In this position, the output member frictionally contacts the friction shoes upon their radial outward movement to unite the input and output members in common rotation. Upon energization, the coil attracts the friction shoes toward the coil and out of a friction-engaging union with the driven output member. A more detailed description of the clutch assembly follows with reference to the figures.
Driving Member
A driving member generally represented at 10 includes an input, rotatable shaft 11, a pair of friction shoes 12, a coil-retaining ring 13 that is held against rotation with shaft 11 and shoes 12 and disposed between them, and an electromagnetic coil 14 within ring 13.
More particularly, shaft 11 has a sleeve 15, conventionally fixed to a splined end of the shaft. The sleeve has various stepped annular portions to receive or support other components of the driving member. A radially extending plate 16 tightly seats against a shoulder 17 on sleeve 15 and with companion plate 18 jointly support friction shoes 12 for pivotal motion. The shoes may be fabricated from light-weight metal such as aluminum. Plate 18 has a relatively large central opening 20 to pass easily shaft 11 and coil-retaining ring 13. Bolts 29 secure plates 16 and 18 together. Each shoe 12 has the same construction and consists of a longitudinally-extending, curved backing strip 21 (FIG. 2) to which bolts 22 secure a longitudinally-extending, curved magnetic pole 23 which may be of any conventional magnetic material such as iron oxide, ferrites, and the like. The curvature of pole 23 matches that of backing strip 21.
A pivot pin 24 fixed at its ends to plates 16 and 18 passes through each backing strip 21 and is journalled for rotation therewith in a bearing sleeve 24a. Counterweights 25 tend to urge shoe 12 counterclockwise around pin 24 as viewed in the upper portion of FIG. 2. The end of strip 21 opposite to that having the counterweights is bifurcated, each leg 26 straddling an eccentric pin 27 and having an oversize eccentric opening 28 through which pin 27 passes. Pin 27 has a central, enlarged lobe 30 and with opening 28 permits limited radial movement of shoe 12 with respect to shaft 11 and circular movement about pin 24 as an axis. Plates 16 and 18 also support the eccentric pins 27 in split bushings 31. There is a gap 32 at all times between shoes 12 and coil-retaining ring 13, regardless of the positions of the shoes. Intermediate its ends, each shoe 12 has a conventional brake, frictional facing 33 riveted or otherwise secured to an outer surface of the shoe.
Shaft 11 and its fixed sleeve 15 also support means to hold ring 13 and its coil 14 against rotation with shaft 11 and thereby also against rotation with friction shoes 12. A conventional roller bearing generally indicated at 34 is butted against shoulder 35 of sleeve 15 and is also held against lateral displacement by a snap ring 36 which seats in a circumferential groove in coil-retaining ring 13. A retaining ring 37 press fits against another shoulder 38 of sleeve 15 and bears against the lower race of bearing 34, while a sealing ring 40 bears against snap ring 36. A spring 41 compresses an elastomeric tail 42 of sealing ring 40. A locking ring 39 threaded on sleeve 15 buts against retaining ring 37 and is used to tighten the parts in assembly as illustrated.
Coil-retaining ring 13 is of general U-shape in cross-section with an open slot 42 outwardly directed toward poles 23 of friction shoes 12. One leg 13a of ring 13 can be separately formed to aid assembly of the clutch. The bight portion 13b of U-shaped ring 13 seats on the outer race of roller bearing 34 and has a threaded opening 43 used to receive a tool to assemble or dissassemble the ring in the clutch assembly.
Positive hold means are used to keep coil-retaining ring 13 from rotating. In the illustrated embodiment, a mounting plate 44, which can be conventionally fixed to any rigid supporting structure (not shown) such as the end of the motor, has a relative large central opening 45 to pass shaft 11 and locking ring 39 and buts against the left-hand side of coil-retaining ring 13 as viewed in FIG. 1. Screws 46 pass through suitable openings in end plate 44 and engage threaded openings 49 in coil-retaining ring 13 to hold the plate and ring together. A circular plate 47 fits tightly into central opening 45 of end plate 44 and has a flange 47a which seats under the inner annular surface of ring 13. Screws 48 pass through openings in plate 47 and engage threaded openings 50 in coil-retaining ring 13 to hold these parts together. A relatively thin metal sheet 52 lines the three sides of slot 42 defined by ring 13, and a conventional electromagnetic coil 53, which can be encapsulated, thus within slot 42.
Driven Member
The driven member generally represented at 54 (FIGS. 1 and 3) includes a drum 55 having a flange 56 which extends axially over and around friction shoes 12 so as to be cirumferentiall disposed thereabout. Shaft 11 supports drum 55, but since a driving connection is to be made between shoes 12 and flange 56, drum 55 is mounted on the shaft for free rotation therewith. Drum 55 has a hub 57 which rides about shaft 11 on a conventional ball bearing represented at 58. The inner race seats against a shoulder 60 on sleeve 15, while the outer race seats against a shoulder 61 formed in hub 57. A snap ring 62 seated in an annular groove within the bore of hub 57 prevents lateral movement to the left of the driven member as viewed in FIG. 1.
The torque transmission to the driven member can, in turn, be further transmitted by any known means. In the embodiment illustrated, a splined ring 63 is fixed to the exposed side of drum 55 for such torque transmission. Ring 63 has a peripheral rim 64 provided with openings 65. Bolts 66 pass through these openings and engage threaded openings 67 in drum 55. The drum may have holes 68 drilled therein to reduce its weight.
Operation
In operation, shaft 11 is rotated by any standard prime mover, such as an electric motor. With coil 13 de-energized, centrifugal forces generated by rotation of shaft 11 move frictional shoes 12 radially outwardly so that friction facing 33 engages the underside of flange 56, resulting in frictional and radial forces being applied to drum 55. This unites shaft 11 and drum 55 in common rotation and transmits torque to spline ring 63. During this time, coil 13 is stationery with respect to shaft 11, held in place by mounting flange 44 over roller bearing 34.
When it is desired to break the driving connection between the described input and output members, electromagnetic coil is energized through electrical conduit 70, and the resulting current produces magnetic flux. The flux travels a magnetic circuit illustrated by the dotted lines 71 in FIG. 1 and attracts poles 23 on friction shoes 12 toward coil 13, thereby disengaging the input and output members and, more particularly, shaft 11 from drum 55.
It will be appreciated that various changes in the illustrated embodiment are possible without departing from the inventive concept. Although the foregoing describes a presently preferred embodiment, it is understood that the invention may be practiced in still other forms within the scope of the following claims. | A centrifugal clutch is disclosed characterized by the use of an electromagnet to disengage a driven output load from a driving input member. In the clutch assembly, a rotatable output load is disposed about a rotatable drive shaft that carries centrifugal-responsive friction shoes. The shoes contain a magnetic pole an under centrifugal force move radially outwardly during rotation of the shaft to engage frictionally the output load for common rotation. A stationary electromagnetic coil disposed between the shaft and friction shoes attracts the shoes upon energization away from the output load to interrupt the frictional drive connection. | 5 |
FIELD OF THE INVENTION
The present invention relates to fixtures for supporting electronic modules, and more particularly to a fixture for supporting an electronic module in a manner that allows the module to be quickly and easily removed from spaces within a mobile platform that would otherwise be inaccessible or difficult to access by a worker.
BACKGROUND OF THE INVENTION
Present day communication systems used on mobile platforms, and in particular on aircraft, often require multiple electronic modules (i.e., units) to be installed in close physical proximity to other subsystems used on the aircraft. This is particularly true when the electronic units are used in connection with an antenna and/or radio frequency communication system employed on the aircraft. The location of such electronic units in close physical proximity to an antenna mounted on the aircraft is often critical to meet predetermined radio frequency performance requirements. The placement of electronic modules in certain areas of the aircraft may also be dictated by aircraft dynamics or other technical constraints.
In the case of single aisle aircraft, space may be quite limited in the crown area of the aircraft inside the fuselage, just below where the antenna may be mounted. This space can be limited due to high ceiling interiors that leave little space between the top of the ceiling panels and the aircraft fuselage. Typically, this limited space is already quite crowded with existing aircraft systems such as air ducts, power cables, signal cables, control cables and other various conduits necessary for controlling the wide ranging and numerous subsystems typically employed on a commercial aircraft.
In addition to the space limitations on single aisle aircraft described above, there is a trend to use overhead space in twin aisle aircraft for purposes of crew rest quarters or for other storage needs. Thus, the use of this space for these functions further reduces the use of such space for the installation of systems such as inflight entertainment equipment and other electronic components. Thus, the areas within a commercial aircraft where an electronic module can be located where it will be easily accessible without the need to first remove other subsystems, conduits or cabling, can be very limited.
With commercial aircraft applications, still another area where space exists for the installation of electronics units is adjacent the aircraft frame behind the overhead passenger luggage bins. However, access to this space typically requires removal of the luggage bins, which can be very time consuming and expensive. Removal of the passenger luggage bins, simply to gain access to one or more electronic units, is often not a viable option in view of the time and expense needed to remove and reinstall such luggage bins.
The need to remove various aircraft subsystems, conduits, cabling or other components before being able to remove an electronic unit for periodic service, maintenance or repair can significantly add to the time and cost required to perform such maintenance, service or repair work. Removal of existing aircraft subsystems, cables, duct work or hoses before being able to access an electronic unit can result in significant time consuming, costly and complex re-installation procedures. Furthermore, once an aircraft subsystem is removed in order to gain access to an electronic module, the aircraft subsystem often needs to be retested once it is reinstalled. Often times, the removal of such subsystems is necessary because attempted removal of the electronic unit without first removing other subsystems, cables or duct work, which is in the way of access to the electronic module, can easily result in damage to the subsystem, cables or other elements if same are not first removed. Likewise, periodic removal and replacement of existing aircraft systems can result in damage to the existing aircraft systems resulting in the need for time consuming and costly repair of existing systems before an aircraft can be returned to service.
It will also be appreciated that in many applications, and particularly in commercial aircraft maintenance and repair work, the ability to quickly remove electronic units from an aircraft is crucial to minimizing down time of the aircraft and ensuring that the aircraft returns to service as quickly as possible.
Similar constraints apply to other mobile platforms such as business aircraft, all types of military aircraft, submarines and other marine vessels. Often the space constraints on these other mobile platforms are even more serious and available space is even harder to access.
In view of the foregoing there is a need for an apparatus that enables quick and easy removal and replacement of an electronic unit within a difficult to access area of a structure. In particular, there is a need for such an apparatus which can be easily used within a mobile platform, for example, an aircraft, and which permits an electronic module supported on the apparatus to be quickly and easily removed from otherwise inaccessible areas without the need to first remove other various subsystems, conduits, cables or control elements typically located within an aircraft.
SUMMARY OF THE INVENTION
The present invention is directed to an apparatus and method for supporting a subcomponent in a manner that allows the subcomponent to be quickly and easily removed from an area within a structure, where the subcomponent would otherwise be difficult or impossible to access by a worker without removal of other additional significant components before removal of the subcomponent. In one preferred form the apparatus comprises a fixture which is fixedly mounted to an interior wall or frame of the structure. Merely by way of example, the structure may comprise a commercial aircraft, although it will be appreciated that any fixed structure or other mobile platform would benefit from the use of the apparatus of the present invention, provided such structure or mobile platform requires removal of one or more important subcomponents for periodic maintenance, repair or testing, where such subcomponents may be located in congested areas which make access difficult.
In one preferred form the apparatus of the present invention comprises a fixture having a frame onto which the subcomponent may be disposed. One preferred embodiment allows for the insertion of the subcomponent, which comprises an electronics module, into the frame. The frame-includes one or more components that allow it to be fixedly secured to a frame like portion of the structure or mobile platform. The frame allows for an external cable, such as an electrical cable, to be coupled to the electronics module. In one preferred form the frame also allows for an external cooling supply conduit to be coupled to the electronics module to supply cooling airflow to the electronics module.
It is a principal advantage of the present invention that the fixture allows insertion and supporting of the electronics module without the need to remove additional structure or components which may otherwise impede direct removal of the electronics module. Thus, the fixture allows the electronics module to be inserted or removed quickly and easily from the frame thereof, thus obviating the need to remove other components that would be necessary in order to remove the electronics unit were it to be supported directly from a frame of the structure or mobile platform.
In alternative preferred embodiments the apparatus further comprises a track upon which the subcomponent (e.g., electronics module) can be moved along into a very tight, confined area that is otherwise impossible to access with one or more hands of the user. A tether coupled to the electronics module allows it to be guided into and out of the frame of the apparatus.
In yet another preferred embodiment the frame of the apparatus is sufficiently large to accommodate a plurality of subcomponents (e.g., electronic modules) disposed adjacent one another within the frame. Each of the preferred embodiments of the present invention enable a subcomponent, e.g. an electronics module, to be quickly and easily removed from a very confined area where removal would otherwise necessitate first removing various other subcomponents, conduits or tubing before the user would actually be able to have sufficient access to the subcomponent to remove same directly from the structure to which it is supported. The present invention thus significantly reduces the time needed to remove and replace various electronic modules, which often need to be periodically removed, tested and then reinstalled on a mobile platform, such as a commercial aircraft.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
FIG. 1 is a perspective view of a fixture in accordance with a preferred embodiment of the present invention with an electronics module inserted into the fixture;
FIG. 2 is a side elevational view of the electronics module of FIG. 1 installed within the fixture frame;
FIG. 3 is a simplified side view of the fixture installed behind a luggage bin in a commercial aircraft;
FIG. 4 shows the electronic module shown in FIG. 3 installed in the frame of the fixture without the need to first remove the luggage bin;
FIG. 5 illustrates an alternative preferred mounting location for the fixture above wiring and tubing in the crown area of a commercial aircraft;
FIG. 6 illustrates an alternative preferred form of the fixture of the present invention wherein a telescoping cooling conduit is employed with an electronics module;
FIG. 7 illustrates an alternative preferred form of the present invention wherein the fixture has a length sufficient to support a plurality of independent modules therein adjacent one another;
FIG. 7A is a simplified perspective view of the fixture of FIG. 7 ;
FIG. 8 illustrates an alternative preferred embodiment of the fixture of the present invention wherein a guide track and a tether are employed for aiding insertion and removal of an electronics module;
FIG. 9 illustrates a cross sectional end view of the guide track shown in FIG. 8 in accordance with section line 9 — 9 in FIG. 8 and
FIG. 10 illustrates a cross sectional end view, similar to FIG. 9 , of an alternative preferred form of the guide track of FIG. 8 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.
Referring to FIG. 1 , there is shown an apparatus 10 in accordance with a preferred embodiment of the present invention. The apparatus 10 essentially forms a fixture to which a subcomponent, for example an electronics module 12 , can be coupled to and supported from. As will be described in the following paragraphs, the fixture 10 is supported from a structure or frame in an area that would be generally inaccessible to a worker without the need to first remove various other components to gain access to the electronics module 12 . For example, the fixture 10 could be located to an interior structural wall of a mobile platform such as an aircraft where access would generally be limited because of other aircraft subsystems, conduits, tubing or other structural elements that would impede access to the module 12 . Thus, the fixture 10 forms a means by which the module 12 can be quickly and easily removed by a worker without the need to first remove other subsystems, cabling, conduits, etc. to permit removal and re-installation of the module 12 into the fixture 10 .
Throughout the following discussion, the subcomponent 12 will be referred to as the “electronics module” 12 . However, it will be appreciated the fixture 10 is not limited to use with only an electronics module. The electronics module 12 , as will be appreciated by those skilled in the art, could comprise any type of electrical or electromechanical subsystem or component that may need to be periodically removed for maintenance, repair, testing, etc., from an area of a fixed structured or a mobile platform where access would be difficult without first removing various other components in the vicinity of the module 12 .
With further reference to FIG. 1 , the fixture 10 comprises a frame 14 forming a generally box-like structure into which the electronics module 12 is inserted. The frame 14 includes one or more flanges or components 16 which allow the frame 14 to be secured to a structural wall or other structural element via one or more brackets or like elements in a desired location within a fixed structure or mobile platform. Each flange 16 preferably includes at least one over-sized opening 16 a through which an external fastening element may be inserted. In this manner the weight of the module 12 can be supported directly from the structure to which the fixture 10 is secured. The frame 14 further includes a rear portion 18 to which a gasket 20 is secured. The gasket 20 is adapted to matingly engage an opening, or potentially a flange, associated with the electronics module 12 such that a cooling airflow can be supplied through a conduit 24 and a manifold 26 to help cool an interior area of the electronics module 12 . It is anticipated that the electronics module 12 will in most instances include a connector or other coupling element 28 to which a suitable electrical cable 30 can be releasably coupled. Thus, insertion of the electronics module 12 within the frame 14 allows essentially an automatic coupling of the air flow conduit 24 to the opening of the electronics module 12 . It will be appreciated immediately, however, that the airflow conduit 24 , manifold 26 and gasket 20 are not essential to the functioning to the fixture 10 . Components 18 , 20 , 24 and 26 are illustrated merely to highlight the advantage that the frame 14 provides should it be necessary to provide a cooling airflow to the electronics module 12 . Alternatively, end portion 14 a of the frame 14 may merely comprise an opening through which a user can manually couple a suitable airflow conduit (or alternatively another electrical cable) to the electronics module 12 if such access is available to the user.
Referring further to FIG. 1 , the frame 14 also preferably includes at least one channel, and more preferably a pair of channels 32 (only one being visible in FIG. 1 ) into which flanges 34 of the electronics module 12 can slide. However, again, it will be appreciated that while this feature enhances alignment of the electronics module 12 with the frame 14 , this feature is not absolutely essential to the functioning of the frame 14 . Instead, electronics module 12 could be adapted to simply be lowered or raised, or otherwise slid into, the frame 14 . The use of channels 32 and flanges 34 , however, serves to help the user align and guide the module 12 into the frame 14 .
The frame 14 further preferably includes a suitable latch 36 which can be moved between an open position, wherein the electronic module 12 can be slid into the frame, as shown in FIG. 1 , and a closed position in which the latch overlies a portion of the electronics module 12 and prevents ready removal of the module from the frame 14 . To aid insertion and removal of the electronics module 12 , it will be appreciated that this component could include a handle 38 or another suitable member to aid the user in grasping and controlling the module 12 as it is removed or installed relative to the frame 14 . The module 12 is shown installed in the frame in FIG. 2 .
Referring to FIG. 3 , the electronics module 12 is shown within an aircraft fuselage 40 . In this example, a luggage bin 42 would otherwise impede access to the area that the electronics module 12 is preferably located, that area being designated by reference numeral 43 . The frame 14 of the fixture 10 is first secured to either an outer surface of the luggage bin 42 or an interior surface 44 of the fuselage 44 in an area generally behind the luggage bin 42 . The electrical cabling 30 is then secured to the electronics module 12 . A maintenance worker, technician, etc. then manually guides the electronics module 12 into the frame 14 where it automatically engages with the gasket 20 (FIG. 1 ). Thus, a cooling airflow can be provided through conduit 24 into the module 12 , as well as the needed electrical signals via electrical cable 30 . Most importantly, the worker is not required to first remove the luggage bin 42 to gain direct access to the electronics module 12 . The fixture 14 allows the worker to insert the electronics module merely by guiding it behind the luggage bin 42 , and even where the frame 14 is mostly obscured by the luggage bin 42 .
It will also be appreciated that while the electrical cabling 30 and the conduit 24 have been shown as independent components, that suitable cabling and conduits could be coupled within a common sheath or housing such that both electrical and airflow connections are made with the electronics unit 12 before the electronics module 12 is inserted into the frame 14 . Alternatively, the use of the airflow conduit 24 can be omitted entirely. FIG. 4 shows the electronics module 12 installed within the fixture 10 .
Referring to FIG. 5 , an alternative preferred mounting location for the apparatus 10 of the present invention is shown partially above the luggage bin 42 . In this example the electrical cable 30 is routed around existing aircraft cabling and duct work 44 . Still further, other aircraft subsystems such as tubing and ducting 46 , which would otherwise impede removal and insertion of an electronics module 12 ′, still does not pose an obstacle to removal of the module 12 ′. In this example, the electronics module 12 ′ has coupled to it the electronics cable 30 at one end and the cooling airflow conduit 24 at the other end. To remove the module 12 ′ the electronics cable 30 and cooling airflow cable 24 are each uncoupled from the module 12 ′. The module is then moved initially to the right in the drawing of FIG. 5 , and then below the ducting 46 to the left. In aircraft applications, it will also be appreciated that standard plug-like components, such as ARINC 600 connectors, can be employed for facilitating the electrical and/or cooling connections if desired. Regardless of the specific type of connectors employed for the purpose of supplying electrical signals, electrical power or a cooling airflow to the electronics module 12 ′, insertion and removal of the module from the apparatus 10 is not impeded by the components 44 and 46 disposed in close proximity to the frame 14 of the fixture 10 .
Referring now to FIG. 6 , a fixture 50 in accordance with an alternative preferred embodiment of the present invention is shown. Fixture 50 is essentially identical to fixture 10 with the exception that the fixture 50 includes a telescoping cooling interface 52 which receives a first portion 54 of a cooling conduit and places portion 54 in airflow communication with a second airflow conduit 56 . Instead of a telescoping interface, however, a telescoping electrical cable-like structure could just as readily be employed. Thus, as electronics module 12 is removed from the fixture 50 , first conduit portion 54 is withdrawn from portion 56 . When the module 12 is reattached to the fixture 50 , first conduit portion 54 is telescopically engaged within second conduit portion 56 . Electrical cabling 30 is also removably coupled to the electronics module 12 . With this embodiment, the electronics module 12 can be easily withdrawn from an area generally behind the luggage bin 42 within the fuselage 40 of an aircraft. The first conduit portion 54 can be constructed such that it can only be removed from the second conduit portion 56 a limited amount or, alternatively, such that it can be removed from second conduit portion 56 entirely.
Referring now to FIGS. 7 and 7A , a fixture 60 in accordance with yet another alternative preferred embodiment of the present invention is shown. Fixture 60 has a length, designated by arrow 62 , which is sufficient to hold a plurality of electronic modules 12 a , 12 b , 12 c adjacent one another. It will be appreciated that each electronics module 12 a , 12 b and 12 c needs to include a suitable interface such that electrical signals and/or power from cabling 30 can be supplied from a first one of the electronic units 12 a successively to the second and third electronics modules 12 b and 12 c . The construction of the fixture 60 is otherwise similar to fixture 10 and includes flanges 60 a or other mounting components 64 for enabling a frame 66 of the fixture 60 to be secured to a structural member, wall, etc. as needed. The frame 66 includes a pair of flanges 66 a that receive the modules 12 a , 12 b and 12 c . In this example the majority of the fixture 60 is disposed behind the luggage bin 42 and the modules 12 a , 12 b and 12 c would be difficult, if not impossible, to remove directly without first removing the entire luggage bin 42 , without use of the fixture 60 . The modules 12 a - 12 c are removed along a path designated by arrow 69 . It will also be appreciated that with the fixture 60 , a supply of cooling airflow from a cooling airflow conduit 68 can be directed around each of the electronic modules 12 a , 12 b and 12 c or alternatively, if suitable interfaces are provided, through interior portions of each of the electronic modules 12 a - 12 c . Alternatively, cooling airflow conduit 68 could comprise another electrical cable for coupling with a rear mounted connector on the module 12 c.
Referring now to FIG. 8 , a fixture 70 in accordance with yet another alternative preferred embodiment of the present invention is shown. In this embodiment a track 72 is coupled to supports 74 associated with the luggage bin 42 or with the fuselage 40 of the aircraft.
Referring briefly to FIG. 8 and FIG. 9 , the track 72 can be seen in greater detail as comprising two facing U-shaped portions which are adapted to engage with two oppositely extending flanges 78 a formed on an electronics module 78 . The track 72 serves to guide the electronics module 78 towards a frame 80 of the fixture 70 . In this regard it will be appreciated that the track 72 preferably extends within an interior area of the fixture 70 . As such, the fixture 70 , which is otherwise substantially identical in construction to fixture 10 , does not require the channels 32 described in connection with fixture 10 . Fixture 70 may also include an airflow supply conduit 82 coupled to the frame 80 for supplying a cooling airflow into the fixture 70 . Importantly, a tether or other form of cabling 84 is provided that is attached at a first end 86 to attachment structure 88 on the electronics module 78 , and at a second end 90 to a permanent attachment point 92 associated either with the luggage bin 42 or with other permanent structure in the vicinity of the luggage bin. A portion of the tether 84 is also secured to a manifold 98 to prevent the possibility of the manifold and/or conduit 82 falling behind and below the luggage bin 42 when the module 78 is removed. Removal of the electronics module 78 is accomplished by the user pulling on the tether in the direction of arrow 94 , which causes the electronics module 78 to be withdrawn along the path defined by track 72 to a position where same can be easily grasped by the user. Re-insertion of the electronics module 78 into the fixture 70 is accomplished by the user initially urging the electronics module along the track 72 in the direction of arrow 96 . As the electronics module 78 begins to pass behind the luggage bin 42 , gravity urges it down into the fixture 70 where a coupling is made with the electrical cable 30 . Thus, removal of the electronics module 78 , as well as reinsertion of the electronics module 78 into the fixture 70 , can be accomplished even without the user having visual access of any portion of the fixture 70 . The use of the tether 84 also eliminates the possibility of the electronics cable 30 being lost behind the luggage bin 42 .
With brief reference to FIG. 10 , an alternative preferred track 100 is shown. In this embodiment, track 100 includes a pair of ledges 102 and a central opening 104 . An electronics module 106 having a pair of oppositely extending flanges 108 is adapted to slide within the track 100 . It will be appreciated that a wide range of different track shapes could be employed to perform the needed function of allowing the electronics module 78 or 106 to be guided into position into the fixture 70 . Accordingly, the present invention is not limited to one specific form of track.
The various preferred embodiments of the present invention all provide for quick and easy removal and installation of an electronics module or other form of component into a fixture disposed in a generally difficult to access area of a structure or mobile platform. While the fixture of the present invention is particularly well suited for use on mobile platforms such as aircraft, it will be appreciated that the fixture can be employed in any difficult to access area which would otherwise require the removal of various components before an electronics module or other like component can be removed for service or testing.
The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention. | A fixture for supporting an electronics module or like component in a generally inaccessible area within a structure. In one preferred form the fixture is adapted to be mounted within a fuselage of an aircraft or other mobile platform in an area that would not permit direct removal of an electronics module for maintenance or repair without first removing other aircraft subsystems, tubing or ducting. The fixture allows the electronics module to be slidably inserted and supported in an area in a manner that allows easy installation and removal of the electronics module without the need to remove other subcomponents disposed adjacent the fixture. The fixture includes provisions for coupling of an air supply thereto such that the electronics module can be cooled. The fixture is lightweight, compact and can be secured in a wide variety of orientations and locations within an aircraft or other structure to make most efficient use of the limited available space in commercial aircraft and other structures. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to mattresses for use in association with beds and other support platforms. The present invention relates more specifically to a foam containing mattress assembly having a pressure relieving structure comprising semi-independent foam pillars, a method of manufacture thereof, and a method of treating decubitus ulcers therewith.
2. Description of the Related Art
Patients and other persons restricted to bed for extended periods incur the risk of decubitus ulcers formation. Decubitus ulcers (also referred to as bed sores, pressure sores or pressure ulcers) are formed due to an interruption of blood flow in the capillaries below skin tissue due to pressure against the skin. The highest risk areas for such ulcer formation are those areas where there exists a bony prominence, which tends to shut down capillaries sandwiched between the bony prominence and the underlying support surface. When considering the redistribution of body weight and the formation of decubitus ulcers, historically, the trochanter (hip) and the heels are the body sites of greatest concern because these are the areas most frequently involved in decubitus ulcer formations which afflict bedridden or otherwise immobile patients. Generally, as is well known in the art, blood flows through the capillaries at an approximate pressure of 32 millimeters of mercury (mm Hg). This pressure can be somewhat lower for elderly individuals or individuals in poor health or with nutritional deficiencies. Once the net external pressure on a capillary exceeds its internal blood pressure, occlusion occurs, preventing the afflicted capillaries from supplying oxygen and nutrition to the skin in close proximity thereto. Tissue trauma may then set in with the resultant tissue decay and ulcer formation. Movement of the afflicted individual into different positions generally helps in restoring blood circulation into the effected areas. However, such movement is, either not always possible or is in some instances neglected.
Additionally, even shorter bed rest periods by healthy individuals on a mattress that does not relieve or reduce the pressure exerted on the user is likely to be considered uncomfortable. Conversely, a mattress that does not provide sufficient firmness or support is also likely to be uncomfortable.
In attempting to avoid the problem of decubitus ulcers in bedridden individuals and to provide greater user comfort to those spending substantial amounts of time in bed, a variety of techniques and devices have been used in the past. For instance, air mattress overlays, air mattresses (static and dynamic), water mattress overlays, water mattresses, gel-like overlays, specialty care beds, foam overlays and various types of other mattresses have been introduced in an attempt to avoid the above noted problems with decubitus ulcers and general user discomfort. Some relatively expensive motorized and/or dynamic devices have been quite successful in solving these problems. However, their cost and relative complexity drastically reduce the breadth of market to which such devices can be effectively offered.
Therefore, to date, no non mechanized device has been wholly successful in meeting these needs, at a cost which, in view of government cutbacks in such programs as Medicare, and stringent, and in some case draconian, cost restrictions, would make such devices readily accessible. The meeting of these needs, in a reasonably economical fashion, is the goal of the present invention.
BRIEF SUMMARY OF THE INVENTION
The present invention provides a non-mechanized mattress assembly that possesses a plurality of semi-independent foam pillars comprising an upper portion of the mattress. This mattress assembly may be fabricated from a single piece of deformable material, such as foam, or, in the presently preferred embodiment, comprises a plurality of core components, for example, a foam base, a foam body support cushion, and a foot cushion insert, which are placed in a contiguous operatively coactive manner. In a multiple component embodiment, these components may be held in place by appropriate contouring of their structures, may be bonded together, or may be fixedly attached in any other suitable manner as is presently known in the art, so as to fix their relative orientation.
Once so placed, or assembled, or in the single component embodiment, after fabrication, a removable fabric cover envelops this mattress core assembly. Most usually, the completed mattress core is generally rectangular in shape.
In the multiple component embodiment, the base component supports the other elements of the mattress core, and, therefore has the same lateral and longitudinal dimensions, as does the entire assembled mattress core. The overall height of the covered mattress assembly, in either the single component, or the multiple component embodiment will generally approximate the thickness of a present day medical mattress, from about 5 to about 7 inches. The height (or depth) of the base generally ranges from about 1 to about 2 inches, except as may be necessitated by any applicable contouring requirements. The base is less deformable than is either the body support cushion or the foot support insert. Though the base is generally symmetrical, during the process of placing the components into alignment, one of the short edges of the base is designated as the top edge of the base, and thereby also of the assembled mattress core.
The body support cushion component is made from a rectangular solid foam element whose upper surface is cut into a plurality of solid pillars, which are most commonly arranged in some systematic manner. This cushion is longitudinally symmetrical about its central longitudinal axis. In the presently preferred embodiment, the rectangular solid pillars are grouped into a central array comprising pillars with generally square top surfaces, and edge rows of rectangular solid pillars having rectangular top faces. Making repeated cuts into the top of the body cushion creates these pillars. The depth of the cuts into the surface of the body support cushion is preferably approximately one half to three quarters of the shortest dimension of the face of the pillar, or roughly one third to two thirds the overall thickness of the body support cushion, in the multi component embodiment.
The foot cushion insert, in the multi component embodiment, is a generally trapezoidal geometric solid comprised of polyurethane foam, or other suitable material, which could include air, or other fluid. This trapezoid is oriented so that its thickness is greater in that portion proximate to the body support cushion, and lesser in that portion remote from the body support cushion, thereby resulting in the insert having a thick edge and a thin edge, and a downward slope from the direction of the designated top edge of the mattress, to the designated bottom edge of the mattress.
Viewed from the top, the trapezoid is substantially rectangular in shape. The insert is, most usually, more easily deformable than both the base and the body support cushion. The same slope will generally be fabricated into the single component embodiment, in the same relative location.
The multiple component embodiment of the present invention is assembled in the following manner. The base is placed in the desired orientation. The body support cushion is aligned so that the top edge of the cushion is in registry with the selected top edge of the base. The foot insert is then placed so that the thick edge of the insert abuts the bottom edge of the body support cushion, the thin edge of the insert is in registry with the bottom edge of the base, and the sides of the assembled cushion are in substantial registry with the sides of the base. The base, body support cushion, and insert, are then secured in position.
A zippered fabric cover then removeably envelops the assembled mattress core. The resultant structure defines a plurality of semi-independently compressible pillars that provide appropriate support to the upper portion of a person in a supine, or reclining position on the mattress, and an inclined uniform surface that supports the feet and connective portions of the person in question.
An object of the present invention is to provide a non-mechanized pressure-reducing mattress that provides therapeutic benefits to a person confined thereto for a substantial period.
Another object of the present invention is to provide a mattress, which prevents or minimizes capillary damage to those who are confined thereto.
A further object of the present invention is to provide a reasonably economical pressure relieving mattress that provides therapeutic benefits to a mammal confined thereto for a substantial period.
Yet another object of the present invention is to provide a relatively lightweight pressure-relieving mattress.
A still further object of the present invention is to provide a mattress, that, when hot wires are used to cut the slots which create the semi-independent pillars, is easy and relatively affordable to manufacture.
Still another object of the present invention is to provide a method of alleviating or minimizing the occurrence of decubitus ulcers on a person confined to a bed for a significant period of time, by the use of the semi-independent pillar containing mattress disclosed herein.
A yet further object of the present invention is to provide a decubitus preventing or alleviating mattress containing semi-independent pressure relieving pillars which is more economical than those of equal efficacy known to the prior art.
These and still further objects as shall hereinafter appear are readily fulfilled by the novel pressure relieving mattress of the present invention in a remarkably unexpected manner as will be readily discerned from the following detailed description of an exemplary embodiment thereof especially when read in conjunction with the accompanying drawings in which like parts bear like numerals throughout the several views.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is an exploded perspective view of the cushioning components of the mattress of the present invention.
FIG. 2 a is a top plan view of the body support cushion component of the present invention.
FIG. 2 b is a side view of the body support cushion component of the present invention.
FIG. 2 c is an end view of the body support cushion component of the present invention.
FIG. 2 d is a detailed view of a cut made into the body support cushion component of the present invention.
FIG. 3 a is a detailed top plan view of the central pillars of the body support cushion component of the present invention.
FIG. 3 b is a detailed cross-sectional view of a number of the central pillars in the body support cushion component of the present invention.
FIG. 4 a is a top plan view of the foot cushion insert component of the present invention.
FIG. 4 b is an end view of the foot cushion insert component of the present invention.
FIG. 4 c is a side view of the foot cushion insert component of the present invention.
FIG. 5 a is an exploded view of the upper and lower components of a cover appropriate for use in conjunction with the present invention.
FIG. 5 b is an assembled view of the cover shown in FIG. 5 a.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The cushioning components of the first embodiment 10 are displayed in an exploded view shown in FIG. 1 . The three basic components of mattress assembly 11 include foam base 12 , foam body support cushion 14 , and foot cushion insert 16 .
Foam base 12 is a substantially rectangular solid structure having end walls 18 sidewalls 20 , surfaces 22 , and body 23 . The dimensions of foam base 12 viewed from above may be similar to those of any standard mattress, particularly medical mattresses, but are preferably approximately 35 inches wide by 80 inches long. The thickness of foam base 12 may vary according to the needs of the application and would range anywhere from about one inch to about two inches, or even more than two inches. In addition, the choice of foam material for base 12 permits variations in the overall resiliency of the mattress. In the preferred embodiment, foam base 12 is presently preferably constructed from a polyurethane core material having 1.8 lb. per cubic foot density and 33 lb. IFD (Indention Force Deflection). However any suitable similar foam presently used in this field of endeavor may be used within the spirit of the present invention.
As shown in FIG. 4, foot insert cushion 16 comprises a generally trapezoidal solid having thick end wall 24 , thin end wall 25 , top surface 26 , and sidewalls 28 . In the preferred embodiment, foot cushion ( 16 ) is constructed from a polyurethane viscoelastil foam core material having 3.8 lb. density and 10 lb. IFD. However, any material possessing the desired softness and deformability characteristics may be employed within the spirit of the present invention. As viewed in FIG. 1 cushion 16 , when viewed from either the top or the bottom, is generally rectangular in shape.
As shown in FIG. 2 the detailed structure of foam body support cushion 14 is described below. Body support cushion 14 is a generally rectangular solid foam element having top surface 30 , bottom surface 32 , body 34 , side walls 36 , top end wall 38 , and bottom end wall 39 .
Body 34 is cut, into a plurality of foam pillars including central pillars 40 , and edge pillars 42 . The cuts into body 34 which define pillars 40 , 42 begin at the top of surface 30 of body 34 , and extend approximately ½ of the way from top surface 30 towards bottom surface 32 . The degree of independence of the pillars depends, at least in part, upon the depths of the cuts used to create these pillars. Plainly if the cuts extend 100% of the way through body 34 , the pillars would be substantially 100% independent. Equally plainly, if the cuts extend a minuscule percentage of the way through body 34 , the pillars would be substantially dependent such that compression or movement of one pillar is readily transmitted to the adjacent pillar. Therefore, a cut that extends part way into body 34 from top surface 30 provides pillars 40 , 42 , with a limited amount of independence. Applicant believes, but does not desire to be bound by, that the independence of such pillars is also related to the relationship between the dimension of the face of a pillar, 40 , 42 , having the smallest value, and the depth of such a cut. Applicant believes that in certain circumstances, the depth of the cuts could range from about one sixth to about five sixths of the depth of the body cushion 14 , and that more optimally, the depth of the cuts could range from about 25% to about 75% of the depth of body cushion 14 , or also about 50% of to approximately 100% or more, of the face dimension noted above.
In the presently preferred embodiment pillars 40 are substantially square, while pillars 42 are substantially rectangular. Pillars 42 are adjacent sidewalls 36 , while pillars 40 are not adjacent to the longitudinal sidewalls 36 . In the preferred embodiment, body support cushion 14 is constructed from a polyurethane core material having 1.8 lb. density per cubic foot, and 21 lb. IFD. This provides a softer top layer compared to the firmer under layer comprising foam base 12 . However many such foams are currently available, and could well be used within the spirit of the present invention.
Each of the three cushioning components of foam mattress assembly 11 are secured one to another in a manner sufficient to prevent layer shifting between the components, after they have been placed in the proper arrangement. Thick end wall 24 of insert 16 is placed in intimate contact with bottom end wall 39 of body support cushion 14 . In the presently preferred embodiment, this configuration has the result of causing the top surface 26 of foot insert 16 to slope downward away from body cushion 14 . Body support cushion 14 and insert 16 are both placed atop foam base 12 , while the intimate contact between walls 29 and 39 is either maintained or reestablished prior to securing theses to components in place.
Such securing could be accomplished in a variety of manners well known in the art. For example the cushioning components could be contoured so as to allow for a force fit intimate contact between components. In the presently preferred embodiment, the cushioning components could also be bonded together in the proper configuration.
This bonding would typically take the form of an adhesive agent that does not alter the foam core shape or the cushioning performance of the foam components. In addition, the bonding agent should not emit appreciable odors after curing and no bonding agent residue should extend beyond the outer edges of the foam core components. A variety of bonding agents known in the industry are suitable for assembling the mattress core 11 in the manner described.
Reference is now made to FIG. 2 for a detailed description of the structure of body support cushion 14 of the present invention. FIG. 2 a is a top plan view showing the array of foam pillars exposed on top surface 30 of body support cushion 14 . In this view the array of central support pillars 40 is seen intermediate edge row pillars 42 . In this view it can also be seen that central support pillars 40 have a generally square upper surface, while edge row support pillars 42 have a generally rectangular upper surface. The larger top surfaces afforded edge row pillars 42 provide enclosing support to the patient positioned within a central area of the mattress. The larger pillars 42 at the longitudinal edges of the mattress incorporated within the present embodiment 10 tend to contain the patient within the central portion of the mattress over the smaller square-faced central foam pillars 40 .
In the presently preferred embodiment, the array of central support pillars 40 positioned along the center of support cushion 14 comprises 32 columns by 14 rows for a total of 448 discrete support pillars. The two sets of edge row pillars 42 which border central support pillars 40 , each comprise 32 discrete support pillars. Central support pillars 40 present 2 inch by 2-inch top surfaces in the preferred embodiment as described in more detail below; edge row pillars 42 present 2 inch by 3.5 inch top surfaces. These dimensions provide overall dimensions of approximately 35 inches by 64 inches for body support cushion 14 . Variations are possible in the overall size of support cushion 14 by adding or removing rows of central support pillars 40 to vary the width of embodiment 10 , and/or by adding or removing columns of central support pillars 40 bounded by edge row pillars 42 to vary the length thereof. As is referenced elsewhere herein, the size of the pillars 40 from the plan view may vary to some degree, although approximately two inches by two inches plus or minus about a half inch is preferred, though central pillars ranging from about 1 inch square to about 4 inches square could be used in various applications of the present invention, particularly if the mattress thickness is increased, for example to possibly 9 inches for a home health care product, or even possibly to as much as 12 inches for a hyperbaric mattress.
FIG. 2 b is a side view of the structure of body support cushion 14 of the present invention showing the manner in which the array of central support pillars 40 are cut into top surface 30 of body support cushion 14 . The dashed line in FIG. 2 b indicates the approximate depth to which the cuts in top surface 30 are made into the solid rectangular body structure 34 of support cushion 14 .
An exemplary row of foam pillars 40 is displayed.
FIG. 2 c is an end view of support cushion 14 of the present invention showing a complete column of pillars comprising central support foam pillars 40 , and two of edge row pillars 42 . This dashed line also indicates the approximate depth of the cuts made in order to form the semi-independent foam pillars 40 .
FIG. 2 d is a detail of section A shown in FIG. 2 c, disclosing the manner in which slot 50 is made in the top surface 30 of body support cushion 14 . The method of using a hot wire or an array of hot wires to make cuts into foam solids is well known in the art. The process includes heating a wire, typically with electrical current, and forcing the hot wire into a foam element in a manner that cuts a void of relatively narrow width into the foam core. In the present invention the array of cuts necessary to create the array of semi-independent foam pillars could be accomplished with a predefined array of hot wires or a movable hot wire that cuts in sequence each of the necessary slots in the top surface of the foam support cushion.
Although certain aspects of the present invention can be appreciated while still using a saw-cut foam the hot wire cutting technique is most preferred. One of the important advantages of utilizing hot wire cuts as opposed to cuts made with a saw, for the purpose of creating the slot in the top surface of the mattress, relates to the resultant structure walls of the foam pillars 40 , 42 . A saw cut generally leaves the walls of the foam pillars more jagged, or open-celled, for most types of foam. A hot wire cut will slightly sear (melt) and partially seal the walls of the foam pillars in the process of cutting the slot into the top surface of the foam core. In the preferred embodiment of the present invention, the most preferred width of the slot cut in this manner is between approximately {fraction (1/16)}′″ and approximately ⅛″. The slightly seared walls of the foam pillars that result from this process have a smoother surface than those that might result from cutting with a saw. Applicant believes that this smoother surface reduces the coefficient of friction between adjacent pillars 40 , 42 and permits greater independent movement of one pillar of foam with respect to adjacent pillars. Applicant does not desire to be bound by this theory; however, saw cut structures of this geometry are thought to have an increased frictional coefficient between the walls of adjacent pillars. The present invention overcomes problems associated with this increased friction by utilizing a hot wire method for cutting the slots that create foam pillars 40 , 42 . Other cutting techniques (such as laser cutting techniques) that produce a smoother cut than a saw may be utilized in alternate embodiments.
The hot wire cutting process is also believed to obtain another unobvious benefit. Leaving the heated wire in place at the bottom of each slot for some interval after the time necessary to complete cutting the slot in question can incrementally increase the width of the slot at that location. This is believed to be particularly beneficial in the present invention in that the increased width in the base of the slots is believed to distribute the foam stress that would otherwise be concentrated at the bottom of each slot, which reduces the likelihood of tearing or other damage to the pillars. This should add to the durability of a mattress embodying the present invention,
Reference is now made to FIG. 3 a for a detailed view and description of the structure of foam pillar components 40 of the present invention. FIG. 3 a is a plan view of the surface of body support cushion 14 showing the full upper surface of one foam pillar 40 , and a partial view of eight adjacent foam pillars. In the preferred embodiment of the present invention, the upper surface of these central foam support pillars is substantially square in geometry.
Dimension a shown in FIG. 3 a, comprises a fraction of the length of embodiment 10, and is therefore approximately equal to dimension b, which comprises a fraction of the width of embodiment 10. As indicated above, the width of slots 50 cut into upper surface 30 of body support cushion 14 is approximately {fraction (1/16)}′-⅛″ in the preferred embodiment. Applicant believes that slots that are substantially larger than ⅛″ may decrease the amount of the patient interface surface, and thereby increases the amount of interface pressure. Dimension a and dimension b in the preferred embodiment, that is for a medical mattress having the dimensions discussed above, are approximately 2″ each, thereby providing a 2″×2″ square upper surface for each foam pillar 40 .
FIG. 3 b is a partial cross-sectional detailed view of body support cushion 14 , again showing one complete foam pillar 40 . In this view, the depth of slots 50 , disclosed in the preferred embodiment shown as dimension c, is approximately 2″. This is an appropriate depth for an overall thickness of body support cushion 14 having dimension d, which in the preferred embodiment is approximately 6″. Preferably, the dimension c, should be from about ¾ of to even greater than the smaller of dimensions a and b to obtain optimum pressure relief. This would hold true for the multiple component embodiment, as well as the single component embodiment of the present invention.
A variety of dimensions are possible for those dimensions a and b shown in FIG. 3 a, and those dimensions c and d shown in FIG. 3 b. Applicant believes that the a:b ratio for central pillars 40 could range from about 1.5:1 to about 0.67:1 without materially affecting the efficacy of the present invention. Similarly the nominal a:b ratio for the edge pillars is approximately 0.56:1. Applicant believes that this could range from about 0.8:1 to about 0.28:1.
Applicant also believes that a graduated ratio, particularly where the a:b ratio is greatest about the longitudinal axis of the mattress assembly 11 could be employed, to provide even greater lateral support to the occupant of the embodiment 10. Plainly, the inverse of the a:b ratio could also be used within the spirit of the present invention.
In addition various shaped pillars could be employed if desired. For example, if the slots 50 were made with an array of wires, and the body cushion 14 were subjected to lateral compression during the cutting process, then the slots 50 would be in a curvilinear configuration. Further, the wires or wire array could be arranged to obtain almost any desired shape slots 50 and pillars 40 , 42 . For instance, rather than the one-eighth inch slot with an enlarged radius at its lower end (caused by leaving the hot wire in place), each slot could be shaped in teardrop fashion by moving the hot-wire through a tear-drop path during the cutting operation.
Slots could also be cut in a two-step process, which process is presently preferred. In this process, a set of wires is arranged in a parallel array. The wires are heated. The heated wires cut the first set of slots. The relative orientation between the mattress component being cut, and the wires, is shifted by approximately 90 degrees, and the second set of slots are then also cut by the same heated wire array.
Reference is now made to FIGS. 4 a - 4 c for a description of the structure and geometry of the foot cushion component 16 of the present invention. In FIG. 4 a, top surface 26 of foot cushion 16 is displayed. The dimensions of insert 16 are defined primarily by the width of the assembled foam mattress, which, in the preferred embodiment, is approximately 35″. The short dimension of the upper surface 26 of foot cushion 16 is approximately 16″ but is sloped as described in more detail below.
Foot cushion 16 is a generally rectangular foam solid who's top surface 26 that inclines downward from thick end wall 24 towards thin end wall 25 , which comprises the outward edge the insert. This downward inclination provides what has been found to be an appropriate pressure relief for the heels of a patient positioned on the mattress 11 of the present embodiment 10. The thickness of the foot cushion at its thickest dimension, the edge of thick end wall 24 where it abuts support cushion 14 , is approximately the same as the thickness of body support cushion 14 .
FIG. 4 b is an end view of foot cushion component 16 of the present invention showing thin end wall 25 and sloping upper surface 26 . Thin end wall 25 has a thickness approximately one-half that of the thickness of foot cushion 16 where it meets with support cushion 14 , at thick end wall 24 , as previously discussed. This provides adequate inclination to upper surface 26 for insert 16 as described above.
FIG. 4 c is a side view of foot cushion 16 showing in detail the inclined upper surface 26 sloping downward toward thin end wall 25 . While this inclined surface has been shown to have beneficial pressure relieving characteristics, it is of course possible to simplify the structure further by using a rectangular foam core with an orthogonal top surface.
Reference is now made briefly to FIGS. 5 a and 5 b, which disclose the structure of an appropriate fabric cover 60 for enveloping the mattress assembly 11 of the present invention. The cover shown in FIGS. 5 a and 5 b is well known in the art and is marketed in conjunction with various mattresses under the trademark THERAREST® manufactured and sold by Kinetic Concepts, Inc. of San Antonio, Tex., the applicant, and assignee of the present invention.
The basic structure of the fabric cover 60 comprises two components; a lower component 61 is matched with and mated to an upper component 62 . Lower component 61 comprises a bottom cover material 64 having sidewalls 66 , 68 , 70 , and 72 . In the preferred embodiment, bottom cover material 64 is manufactured from a laminated vinyl fabric material, possibly double laminated vinyl material, and has surface dimensions generally equal to those dimensions for the foam mattress, namely 35″×80″. Lower component 61 also contains a plurality of lifting straps 74 that are attached, possibly by stitching, on to the fabric of lower component 60 and facilitate the movement and positioning of the assembled and enclosed mattress. Upper component 62 comprises top cover material 76 and sidewalls 78 , 80 , 82 , and 84 . In a preferred embodiment, top cover material ( 76 ) is manufactured from a poly/nylon denim fabric and is sewn in the configuration shown in FIG. 5 a.
Upper component 62 is permanently and fixedly attached to lower component 61 along a “non-zipper” side of the enclosure 88 (best seen in FIG. 5 b ). This side thereby becomes a “hinge” side of the enclosure and permits the assembled cover to encompass the assembled foam cushion components mating zipper components 90 sewn on to upper cover component 62 and lower cover component 61 provide means for repeatedly opening and closing the cover.
FIG. 5 b also shows the assembled mattress cover with top cover material 76 exposed as indicated. As mentioned above, zipper 90 is shown positioned around approximately three-fourths of the perimeter of the cover to provide closure to the fabric material around the foam components described above. The fabric should have no tension on the surface upon which the patient is intended to rest, so as not to interfere with the therapeutic action of the present invention.
From the foregoing, it is readily apparent that a new and useful embodiment of the present invention has been herein described and illustrated which fulfills all of the aforestated objects in a remarkably unexpected fashion. It is of course understood that such modifications, alterations and adaptations as may readily occur to the artisan confronted with this disclosure are intended within the spirit of this disclosure, which is limited only by the scope of the claims appended hereto. | A foam core cushion mattress assembly provides semi-independent foam pillars on the upper surface of the mattress. The mattress may be unitary, or comprise three cushioning components: a base, a body support cushion, and a foot cushion insert. A removable fabric cover envelops the mattress assembly. The body support cushion is constructed from a flat, rectangular solid, foam element whose upper surface is cut into an array of rectangular solid pillars, preferably by a hot wire cutting method. The array of rectangular solid pillars is grouped into a central array comprising pillars with generally square top surfaces and edge rows of rectangular solid pillars having rectangular top surfaces. The depth of the hot wire cuts into the surface of the body support cushion is preferably approximately one-half the overall thickness of the body support cushion or approximately three fourths of the length of the shortest face of the pillar. A zippered fabric cover removably envelops the assembled cushioning components. The resultant structure defines a plurality of semi-independently compressible pillars, which supports a reclining, or in the supine, position on the mattress. Methods of manufacture, and treatment and alleviation of decubitus ulcer formation are also presented. | 0 |
The invention relates to axle end equipment for a vehicle, in particular an aircraft.
BACKGROUND OF THE INVENTION
Axle end equipments for vehicles, in particular aircraft, are known that comprise a stationary portion for being placed in the axle and a rotary portion for being secured to a wheel carried by the axle.
For example, such equipment may include a tachometer for measuring the speed of rotation of the wheel, and a pressure sensor for measuring the pressure that exists in a tire fitted to the wheel.
The pressure sensor is connected by a cable to the rotary portion. When the wheel is removed, the operator must disassemble the rotary portion and the pressure sensor, and as a result the pressure sensor and the connection between the rotary portion and the pressure sensor run the risk of being damaged.
OBJECT OF THE INVENTION
An object of the invention is to provide equipment that does not present the above-specified drawback.
BRIEF DESCRIPTION OF THE INVENTION
In order to achieve this object, the invention provides axle end equipment for a vehicle, in particular an aircraft, the equipment comprising a stationary portion for securing to the axle and a rotary portion for securing to the wheel carried by the axle, the equipment including first remote connection means for putting a sensor mounted on the wheel into contactless electro-magnetic relationship with the rotary portion of the equipment.
It is thus possible to remove the rotary portion without worrying about the sensor, which, since it has no mechanical or electrical connection with the rotary portion, can be left on the wheel without any risk of damage.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention can be better understood in the light of the following description given with reference to the accompanying drawings, in which:
FIG. 1 is a section view of the end of an aircraft axle fitted with equipment constituting a first embodiment of the invention;
FIG. 2 is a perspective view of a portion of the equipment shown in FIG. 1 , the sleeve and the tachometer being removed;
FIG. 3 is a section view of the end of an aircraft axle fitted with equipment constituting a second embodiment of the invention, integrating a fan for cooling the brake with which the wheel is fitted;
FIG. 4 is a section view of the end of an aircraft axle fitted with equipment constituting a third embodiment of the invention;
FIG. 5 is a perspective view of the equipment shown in FIG. 4 ;
FIG. 6 is a section view analogous to that of FIG. 1 showing a variant of the first embodiment;
FIG. 7 is a section view of the end of an axle fitted with equipment constituting a fourth embodiment of the invention; and
FIG. 8 is a fragmentary perspective view of the FIG. 7 wheel showing the pressure sensor.
DETAILED DESCRIPTION OF THE INVENTION
In a first embodiment shown in FIGS. 1 and 2 , the equipment of the invention is associated with an axle end 1 carrying a wheel 2 of which one half-rim 3 can be seen (the other half-rim being silhouetted as a dashed line).
The equipment shown serves to measure continuously the speed of rotation of the wheel 2 and also the pressure that exists in the tire mounted on the wheel 2 (shown in dashed-line outline).
For this purpose, the equipment comprises a stationary portion 100 comprising a sleeve 101 inserted in the axle 1 and carrying a tachometer 102 having a shaft 103 that extends along the axis of rotation X of the wheel 2 .
The equipment also comprises a rotary portion 200 comprising a cap 201 secured to the half-rim 3 by a clamping collar 202 . The cap 201 carries internally a driver 203 adapted to co-operate with the shaft 103 of the tachometer 102 in order to drive said shaft in rotation when the wheel 2 is rotating. The tachometer 102 includes a first connector 104 having a first cable (not shown) connected thereto and passing along the inside of the axle.
According to the invention, the stationary portion 100 includes a cylindrical portion 105 that extends concentrically about the axis of rotation X of the wheel 2 and that carries a first antenna 106 , in this case a winding of an electrical conductor. The first antenna 106 is connected to a second connector 107 carried by an extension of the sleeve 101 to which a second cable (not shown) is connected that passes along the inside of the cable.
The rotary portion has a cylindrical portion 205 that extends concentrically about the axis of rotation X of the wheel 2 and that carries a second antenna 207 also constituted by a winding of electrical conductor. This antenna extends facing the first antenna 106 of the stationary portion 100 , such that the two antennas interact electromagnetically.
The second antenna 207 is connected by a cable 208 to a third antenna 109 carried by a projection 210 of the cap 201 and constituted by a winding of an electrical conductor.
Facing the third antenna 209 there extends a pressure sensor 211 , which in this example is screwed on a self-closing valve 212 , itself screwed to the half-rim 3 and enabling the pressure sensor 211 to be removed without deflating the tire. The valve 212 is placed at the end of an orifice that communicates with the inside of the tire through the half-rim 3 .
The pressure sensor 211 has a fourth antenna 214 constituted by a winding of an electrical conductor that extends facing the third antenna 209 such that these two antennas interact electromagnetically. The pressure sensor 211 comprises a pressure-sensitive member associated with the fourth antenna 214 so as to cause at least one electromagnetic characteristic of the fourth antenna 214 to vary in response to a pressure level inside the tire.
The device of the invention operates as follows. When the wheel 2 is rotating, the driver 203 that rotates with the wheel 2 drives the shaft 103 of the tachometer so that it rotates, and thus causes a signal to be produced in response that is representative of the speed of rotation of the wheel 2 .
In addition, regardless of whether the wheel 2 is rotating or stationary, the first and second antennas and also the third and fourth antennas continue to remain in electromagnetic interaction, while the second and third antennas are interconnected electrically. As a result, the electromagnetic characteristics of the first antenna 106 , i.e. the antenna that is connected directly to the connector 107 , are influenced by means of the pressure sensor via the electromagnetic connection thus established. It then suffices to apply a current to the first antenna 106 and to read the voltage that appears across the terminals of said antenna in order to obtain a signal that is representative of the pressure that exists inside the tire.
The device of the invention presents several advantages:
it is very easy to remove the wheel 2 . It suffices to remove the clamping collar 202 so as to be able to remove the cap 201 . Since the cap is not connected by any electrical wiring, whether to the connectors 104 , 107 or to the pressure sensor 211 , it is removed very easily without any risk of damaging a connection. In addition, the only mechanical connection between the stationary portion 100 and the rotary portion 200 is constituted by co-operation between the driver 203 and the shaft 103 of the tachometer 102 . Removing the cap 201 disconnects the driver 203 from the shaft 103 and gives access to the nut that holds on the wheel 2 . To put the cap 201 back into place, it suffices to ensure that the driver 203 co-operates properly with the shaft 103 of the tachometer 102 , and that the third antenna 209 is generally in register with the pressure sensor 211 ; the pressure sensor 211 can be changed independently of the remainder of the device of the invention. In addition, making use of a self-closing valve makes such a changeover much easier; it is possible without any disassembly to test the pressure sensor 211 by means of an external unit 300 provided with an antenna 301 that is moved up to the antenna 214 of the pressure sensor 211 , such that these two antennas interact electromagnetically. The external unit should include its own electrical power supply adapted to cause a current to flow in the antenna 301 . The voltage across the terminals of said antenna depends on the pressure that exists inside the tire, thus enabling the operator to measure the pressure inside the tire and possibly decide on taking maintenance action (re-inflation, changing the wheel, or changing the sensor if the sensor is found to be faulty); and the electrical and mechanical systems of the tachometer and of the pressure sensor are completely segregated, such that the failure of one does not lead to the failure of the other.
In a second embodiment of the invention, as shown in FIG. 3 , the equipment of the invention may also incorporate a fan for cooling a brake with which the wheel 2 is fitted. References for elements that are common with the first embodiment have the same numbers as in FIGS. 1 and 2 , together with prime symbols.
In the same manner as before, the sleeve 101 ′ carries a first antenna 106 ′. The cap 102 ′ carries a second antenna 207 ′ facing the first antenna 106 ′ so that the first and second antennas interact electro-magnetically. The cap 201 ′ carries a third antenna 209 ′ electrically connected to the second antenna 207 ′. A pressure sensor 211 ′ is implanted on the half-rim 3 and includes a fourth antenna 214 ′ that faces the third antenna 209 ′ so that the third and fourth antennas interact electromagnetically.
This equipment differs from the above equipment by the tachometer 102 being replaced by a combined motor and tachometer unit 112 ′. The combined unit 112 ′ comprises a motor 113 ′ that is secured to the sleeve 101 ′ and that has a hollow shaft 114 that can be seen projecting towards the end of the axle 1 , and that receives at its end the impeller 115 ′ of a cooling fan. The combined unit 112 ′ also includes a tachometer 116 ′ placed behind the motor 113 ′ and having its shaft 117 ′ extending inside the hollow shaft 114 ′ of the motor 113 ′ so as to project beyond the end thereof.
The rotary portion 200 ′ of the equipment includes a cap 201 ′ that receives a casing 220 ′ for protecting the impeller 115 ′, and also a mask 221 ′ that covers the entire hollow portion of the half-rim 3 .
In order to remove the wheel 2 , the casing 220 ′ and the mask 221 ′ are removed initially so as to gain access to the impeller 115 ′. The nut that secures the impeller 115 ′ to the hollow shaft 114 ′ of the motor 113 is removed in order to enable the impeller 115 ′ to be removed, and then the cap 201 ′ is removed so as to give access to the nut that holds on the wheel 2 .
In the same manner as before, none of the elements constituting the equipment of the invention that are disassembled in order to gain access to the wheel has any electrical connection with the pressure sensor or any other element, such that disassembling these elements leads to no risk of damaging a connection. In addition, the only mechanical connection between the stationary portion 100 ′ and the rotary portion 200 ′ is constituted by the co-operation between the driver 203 ′ (in this case secured to the casing 220 ′) and the shaft 117 ′ of the tachometer 116 ′. This connection is easily disconnected merely by removing the casing 220 ′.
In a third embodiment shown in FIGS. 4 and 5 , use continues to be made of a combined motor and tachometer unit. Nevertheless, the tachometer is no longer placed behind the motor, but instead it is placed around it. In these figures, the references for elements that are common with similar elements in the second embodiment are given the same numbers as in FIG. 3 , associated with double primes.
As can be seen in FIG. 4 , the sleeve 101 ″ has a rear face that carries the motor 113 ″ of the combined unit 112 ″. The motor has a shaft 114 ″ that extends to receive an impeller 115 ″ of the fan.
The sleeve 101 ″ receives the tachometer directly, and for this purpose it includes bearings 120 ″ that guide a pushing 121 ″ in rotation. Between the sleeve 101 ″ and the bushing 121 ″ there extend means 122 ″ for measuring speed of rotation (represented by a cross in the drawings), e.g. variable reluctance means. The bushing 121 ″ extends around the end of the motor 113 ″, and is free to rotate relative thereto.
The bushing 121 ″ is constrained to rotate with the cap 201 ″ of the rotary portion 200 ″ by means of screws 123 ″ (only one screw is visible in FIG. 4 ). Thus, the rotation of the wheel 2 is transmitted to the bushing 121 ″ so that the measurement means 122 ″ generate an electrical signal in response to rotation of the bushing 121 ″.
In the same manner as above, the sleeve 101 ″ carries a first antenna 106 ″. The cap 201 ″ carries a second antenna 207 ″ in register with the first antenna 106 ″ so that the first and second antennas interact electro-magnetically. The cap 201 ″ carries a third antenna 209 ″ electrically connected to the second antenna 207 ″. A pressure sensor 211 ″ is implanted in the half-rim 3 and includes a fourth antenna 214 ″ that extends in register with the third antenna 209 ″ so that the third and fourth antennas interact electromagnetically.
As above, none of the elements of the equipment of the invention that are disassembled in order to gain access to the wheel has any electrical connection with the pressure sensor or any other element, such that disassembling these elements does not lead to any risk of damaging a connection. In addition, the only mechanical connection between the stationary portion 100 ″ and the rotary portion 200 ″ is constituted by screws 123 ″ between the bushing 121 ″ and the cap 201 ″. This drive is easily disassembled merely by unscrewing the screws 123 ″ that become accessible once the impeller 115 ″ has been removed.
Preferably, between the second and third antennas ( 207 / 209 , 207 ′/ 209 ′, 207 ″/ 209 ″), i.e. between the antennas that are secured to the rotary portion, electro-magnetic tuning is provided, e.g. by means of capacitors, so that the circuit comprising the second antenna and the third antenna is resonant at the frequency of the power supply current fed to the first antenna ( 106 , 106 ′, 106 ″). This increases the transmission quality of the pressure acquisition connection, thus making it possible to have a greater distance between the third antenna and the fourth antenna (the antenna secured to the pressure sensor), thus making it possible to reduce the risk of collision between the pressure sensor and the cap when the cap is being removed from the wheel.
FIG. 6 shows a variant of the first embodiment in which the first antenna 106 is carried at the end of the sleeve 101 which extends outwards from the axle 1 . Thus, the stationary portion of the equipment need not be contained completely within the axle, but may project therefrom, at least in part.
The second antenna 207 is still carried by the cylindrical portion 205 secured to the cap 201 , but in this variant the cylindrical portion 205 extends inside the sleeve 101 , such that the second antenna 207 extends inside the first antenna 106 . It should be observed that the second antenna does not penetrate into the axle 101 .
In a fourth embodiment shown in FIGS. 7 and 8 and that does not include a tachometer, the fourth antenna 214 is no longer secured directly to the pressure sensor 211 but is offset so as to be closer to the cap 201 of the rotary portion 200 .
For this purpose, the pressure sensor 211 is associated with a carrier member 220 having two branches that extend against the flanks of spokes of the half-rim 3 of the wheel 2 , matching the shape of the gaps between the spokes. The ends of the branches meet in order to receive the fourth antenna 214 which is thus located close to the cap 201 of the rotary portion 200 . The carrier member 220 is designed to be lightly forced between the spokes of the half-rim 3 , so as to avoid any vibration of the fourth antenna 214 .
The carrier member 220 houses connection wires between the pressure sensor 211 and the fourth antenna 214 , so as to ensure that the wires are protected from impacts.
The third antenna 209 is carried by a projection 221 that extends from the cap 201 but that is much shorter than the projection 210 of the first embodiment shown in FIG. 1 , such that the cap 210 is generally more compact and easier to handle.
The connection wires 208 connecting the third antenna 209 to the second antenna 207 is completely sheltered by the cap and by the projection 221 .
It should be observed that the third antenna 209 is designed to overlap the fourth antenna 214 , thus informing the person carrying out assembly about the angular position of the cap 201 relative to the pressure sensor 211 . The third antenna 209 and the fourth antenna are thus much closer together, thereby improving the efficiency of transmission.
The invention is not limited to the description above, but on the contrary covers any variant coming within the ambit defined by the claims.
In particular, although the sensor implanted on the rim is described as being a pressure sensor, the invention naturally covers the use of other sensors, e.g. a temperature sensor.
Although the equipment shown herein has remote connection means each comprising a pair of antennas in electromagnetic interaction, it is possible to use any other remote connection means, for example infrared means.
Although it is stated that two remote connection means are used, such that the rotary portion has no physical electrical connection either with the sensor or with the rotary portion, the invention also covers equipment in which the only remote connection extends between the rotary portion and the sensor. Under such circumstances, it is necessary to provide an electrical connection of some other type between the rotary portion and the stationary portion, for example a connection by means of brushes. | The invention relates to axle end equipment for a vehicle, in particular an aircraft, the equipment comprising a stationary portion for securing to the axle and a rotary portion for securing to the wheel carried by the axle. According to the invention, the rotary portion comprises first remote connection means in communication with a sensor mounted on the wheel so as to put the sensor and the rotary portion of the equipment into contactless electromagnetic relationship. | 1 |
BACKGROUND OF THE INVENTION
[0001] This invention relates to toilet flush systems that are in wide use and characterized by a floating flapper valve and a float operated water supply valve.
[0002] In the flushing and refill process, a manually operated lever on the holding tank opens a flapper value in the bottom of the tank. This releases the water from the tank into the toilet bowl, displacing the contents of the bowl through an air lock, or “P” trap and into the sewer system. After the tank has emptied from the flush, the flapper valve automatically closes, allowing a fresh supply of water to be retained by the tank. Common toilet designs use a float to control the fresh water supply valve. This assembly is located inside the tank. Upon flushing, the float lowers with the water level to a down position causing the water supply valve to open, filling the empty tank and bowl simultaneously.
[0003] In typical toilet designs, approximately twenty percent of the fresh water from the water supply valve is delivered to the overflow pipe through a tube into the toilet bowl. The remaining eighty percent is discharged directly into the tank. As the tank fills, the float rises with the water to a preset level to an up position causing the water supply valve to close. This stops the filling of both the tank and the bowl.
[0004] Toilets are normally designed so that a more than adequate amount of water is delivered to the bowl at each flush to fully flush out the contents thereof, solid or liquid. A considerable amount of water can be saved by individually adjusting the minimum amount of flush water used for a partial flush containing liquids only. Some known devices address this issue but suffer one primary disadvantage; their control is extremely limited. One type of control addresses the closing of the flapper valve; other types address the closing of the float controlled water supply valve. At the present time, there is no method of interrupting both flushing and filling operations simultaneously, in case of an emergency situation.
[0005] Another problem in an emergency situation is getting access to the plumbing water stop valve usually located outside or below the toilet tank. It is typically very difficult to reach and is usually either seized (stuck open) or cannot be closed without extraordinary effort. On many toilets the water stop is not installed. When this occurs, the toilet tank lid must be removed and the water valve must be closed inside the tank. In addition, when using this method, in order for the valve in the tank to remain closed, the operator must continue to hold the float or else the valve reopens and refilling resumes.
[0006] Interrupting and closing the flapper valve does stop water flow from the tank to the toilet bowl which works fine for partial flushes and toilet bowl cleaning. It does not address emergency situations such as bowl overflows since water will continue into the overflow pipe and into the bowl if the water supply valve is not in a closed position. The closing of the water supply valve insures complete water stoppage for short or prolong occurrences each time the cord's pull knob is actuated.
[0007] Shutting off the water stop valve or accessing the automatic refill mechanism is only available if the operator is aware of them. Often it is the case that individuals do not possess this knowledge. Heretofore, neither the toilet manufacturers nor the product distributors have made efforts to make this information known.
[0008] In the past, the common widespread usage of common toilets was due to the widespread availability of water. However, water in some areas of the world is becoming not so available. Also, the fact that the population is ever increasing creates an even greater demand for water. Many communities are restricting the maximum allowable water to be used within toilets.
[0009] Some communities are now even further giving incentives for users to incorporate some form of water save mechanism within their toilets. The amount of water that is used in a conventional toilet is actually more than is required to effectively remove human waste. It has been found that in most instances the amount of water could be decreased as much as fifty percent and still adequate removal of the waste will occur.
[0010] Prior art toilets are characterized in lacking structural flexibility for adjusting the discharge amount of the flush water therein so that every time when the flush device is actuated, a tankful of water is discharged totally, regardless whether such a large amount of water is needed. This causes a waste of water source, which is uneconomical and detrimental to the environment.
[0011] As mentioned, a problem often encountered is toilet bowl overflow. It is not uncommon for the waste lines which drain the bowl of a conventional toilet to become clogged or otherwise impassable due to waste or some foreign object blocking or slowing the passage. In conventional toilets, once the flush cycle is commenced, all the water in the tank will empty into the bowl whether the bowl can accept it or not.
[0012] The operator of the toilet may not notice the line stoppage until after flushing. If the bowl is unable to drain, the water from the tank fills the bowl and then overflows onto the floor. This overflow can cause extensive damage to the flooring as well as leaving the operator with an unsightly mess to clean.
[0013] Several water saving methods are in current use to conserve water during the toilet flushing operation. One such method is to place a filled water bag or a solid object, such as a brick, in the water tank to displace an equivalent volume of water to thus reduce the volume of water consumed with each flushing.
[0014] In summary, the design of the prior art apparatuses with respect to the design of the instant invention are relatively complicated, require modification of the existing hardware and in some cases, the toilet tank itself requires modification.
SUMMARY OF THE INVENTION
[0015] The present invention solves the problems discussed above by providing a finger-tip access to a water saving retrofiable or original equipped device having a free traveling flexible cord routed from a toilet holding tank to inside non-frictional orifices located at strategic points on major toilet components, able to allow free water flow for full flushes or able to limit flow for partial flushes and stop or interrupt water flow for unusual or emergency functional operations such as toilet bowl cleaning, preventing a bowl overflow, slowing or stopping a flapper valve leak, or help prevent a drowning from occurring simply by pulling a cord.
[0016] Accordingly, besides the objects and advantages of the prior art apparatuses described above, several objects and advantages of the present invention are:
[0017] (a) to provide the usual means of flushing a toilet;
[0018] (b) to provide a means of creating a partial flush;
[0019] (c) to provide a means to ease toilet bowl cleaning;
[0020] (d) to provide a means to prevent toilet bowl overflow;
[0021] (e) to provide a means of slowing or stopping flapper valve leakage;
[0022] (f) to provide finger tip access to a supply water stop;
[0023] (g) to provide a means of automatically resetting the flapper valve zapper whenever the toilet flush handle has been actuated;
[0024] (h) to provide a means of accomplishing all the above with a pull of a cord attached to the flush handle of a toilet, or having the cord strung over the outside wall of a toilet.
[0025] Still further objects and advantages will become apparent from a consideration of the ensuing description and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIG. 1 shows the operating hardware that is found in most standard toilets, and the location of the operating cord, a front view without toilet tank walls.
[0027] FIG. 2 shows a top view of a flapper valve zapper attached to an overflow pipe positioned above the flapper value.
[0028] FIG. 3 shows a top, side, and front view of a flapper zapper.
[0029] FIG. 4 shows a top and side view of one of the locations where the cord will be attached to the water supply valve float.
[0030] FIGS. 5A and 5B show a top view of two diverters used to divert the cord from the flapper zapper to the float diverters that are attached to the overflow pipe.
[0031] FIG. 6A to 6C shows a side view of three locations of attaching or threading a cord in a loose and free sliding mode on a water supply valve float.
[0032] FIG. 7A shows a top view of a cord with no flattened cord area threaded through the flush handle in a loose and free sliding mode.
[0033] FIGS. 7B and 7C show two cords with flattened cord areas in a loose and free sliding mode being protected by spacers or shims placed around the tank top or lid.
[0034] FIG. 7D shows a blown-up view of a flattened cord area which will insure a positive locked position for the sliding cord-lock when felt necessary for complete water stoppage.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0035] The preferred embodiment of the device 10 as shown in FIG. 1 is comprised of four major elements: a flapper zapper 17 , a cord diverter 24 , a sliding cord-lock 13 , and a flexible cord 19 . The device is designed to be installed in a toilet water tank 39 that incorporates a flapper valve 16 , an overflow pipe 29 , a water fill valve 22 , and a flush chain 15 , that is controlled through a flush arm 14 , which is connected to the flush handle 11 , of the toilet. As shown in FIG. 1 , the device also has a bowl refill adjuster 25 , a level adjuster clip 26 , and a supply inlet 27 , with an adjustable height 30 .
[0036] All major elements of the device may be constructed of plastic or a non-corrosive metal, with plastic preferred. The flapper zapper 17 , consists of an elongated structure which fits around the over flow pipe 29 that includes a means for allowing it to be held in place on the overflow pipe at the flapper valve pivot arms 18 . As best shown in FIG. 2 , the flapper zapper 17 , is comprised of a closed oval elongated structure that includes a means for allowing it to move or pivot freely with a pull of the cord 19 , or pushed up by the flapper valve 16 , when flushing occurs, which is also attached to the pivot arms 18 , of the overflow pipe 29 . As shown in FIG. 3 , flapper zapper 17 also may include flexible legs 34 and a zapper legs orifice 36 . As shown in FIG. 4 , the float 21 has a float water supply orifice 25 .
[0037] State of the art flush flapper valves are characterized by an integral float chamber by which they are buoyant in order to remain elevated once lifted off the toilet bowl valve seat 45 , until the water level subsides in the flush tank 39 . This is an automatic function inherent in the operation of state of the art toilets, by means of a flexible lanyard or a loosely linked chain 15 , attached to chain orifice 32 to initially lift the flapper valve 16 . The lanyard or chain 15 , requires no guide, being lifted by a manually operated flush arm 14 . The toilet mechanism thus far described is standard.
[0038] The flapper valve 16 , of the preferred embodiment is show in FIGS. 1 and 2 , and is comprised of a large diameter body of rubber or the like, having a downwardly faced planar sealing face to engage on the upwardly faced toilet bowl valve seat 45 , with the lift chain 15 coupled to the flapper valve 16 , through a loop or suitable connector, there being a depending peripheral ball within the working component is the cord, a flexible appendage made of material such as polyethylene, polypropylene, vinyl, nylon, rubber, various plasticized impregnated or laminated fibrous materials and etc. The slide cord-lock 13 , is also made of similar materials.
[0039] The cord is attached to an orifice 33 , at the flapper zapper 17 , from where it is routed up and through diverter 24 , held by hose clamp 23 , through the orifice 20 on float 21 (see also FIG. 4 ) shown at FIG. 1 , or as seen at 18 A and 24 B in FIG. 5 which is attached to the upper part of the overflow pipe 29 . From the diverter 5 A and 5 B, having diverter posts 37 and cord protector 38 and diverter leaf spring 40 it is routed to the float 21 , as seen in FIG. 1 , located on the upper part of the water fill valve 22 . The float 21 , shown in FIG. 6 , shows three potential locations of attaching cord 19 , at A 42 , at B 20 , and C 44 , having nylon cable tie 43 in a loose and free sliding mode, at the discretion on the manufacturer or the installer.
[0040] In the leaving the float 21 , and prior to entering the orifice on flush arm 14 , and flush handle 11 , a cord stop 31 , is shown in FIG. 1 and FIG. 7 , that is installed on cord 19 , which prevents an over-pull by the toilet operator which could damage the water saving device 10 , and make it inoperable. The end of cord 19 , is routed through the orifice in the flush arm 14 , and protrudes past the flush handle 11 , with an ample length of cord 19 , that allows attaching the sliding cord-lock 13 , and the cords pull knob 12 . When pushed into the flush handle 11 , which is the reset position, the cord 19 does not interfere with the operation of a normal flush of a toilet. Same holds true if cord is routed over the side of the tank as shown in FIG. 7 utilizing tank lip shims 41 and flattened cord area 46 .
[0041] When cord 19 is pulled out of the flush handle 11 , to comply with various operations the operator might be selecting, the sliding cord-lock 13 , can be activated and slid into the flatten cord area for a more positive locking position to keep cord 19 , from resetting or retreating back into the flush handle 11 , which is the normal position of the cord 19 , if routed over the side of the tank between the shimmed tank and lid.
[0042] From the description above, a number of advantages of the device become evident by the added versatility:
[0043] (a) The device allows the operator of a common toilet to cause a full flush.
[0044] (b) Will permit the average user to provide a water saving mini or partial flush.
[0045] (c) Allows one to flush and empty a toilet bowl for toilet bowl cleaning.
[0046] (d) Permits the user to have finger-tip access to a means of shutting water flow from the water supply valve, done right on the toilet tank.
[0047] (e) Allows the operator to prevent a toilet bowl overflow whenever a toilet or sewer line becomes plugged or stopped up.
[0048] (f) The user will be able to pull and lock the cord on the flush handle and add additional pressure to the top of the flapper valve to either stop or slow the water leak thereby saving precious water, same holds true if cord is routed over and out the side of the toilet tank.
[0049] (g) An inherent automatic result of flushing with this device installed is that the flapper zapper always gets reset with the next flush and does not interfere with future flush operations.
[0050] The manner of using a toilet with this device installed is identical to some of the widely known common toilets in use today. Referring to FIG. 1 , a front view of the controlling device is shown of the toilet tank 39 , with walls cut away to show the device. To initiate a full flush, the user makes sure that the cord 19 , is pushed in or in a reset position on the flush handle, and the same holds true if cord is routed out and over the side of the toilet tank as shown in FIGS. 7A , 7 B, & 7 C. The toilet will now operate normal and the user need only to depress flush handle 11 , to cause flush arm 14 , to lift chain 15 , which lifts flapper valve 16 , making it become buoyant and empties the water stored in the toilet tank 39 , allowing a full flush to take place.
[0051] To initiate a partial flush, one first depresses the flush handle 11 , as if causing a full flush but immediately interrupts the flush by pulling the cord's pull knob 12 as seen at FIG. 7A , B, or 7 C. This stops water flow to and from the toilet tank 39 . Pulling the cord's pull knob lifts float 21 , which stops water flow to tank 39 , and forces the flapper zapper 17 , to push and close the flapper valve 16 , as seen in FIG. 1 , which stops water from getting into the toilet bowl drain 28 , and into the toilet bowl.
[0052] As to how soon should the operator pull the cord's pull knob 12 , after depressing the flush handle 11 , to cause a partial flush is determined by the user visually observing the drop in the toilet bowl water level and making a decision as to what makes for a satisfactory elimination of liquid waste matter.
[0053] Pushing in or resetting the cord's pull knob 12 , allows the float 21 , to move freely to replenish the tank and bowl with water to a normal level and allow the flapper zapper 17 , to relax against the closed flapper valve 16 . The next flush caused by a user will automatically reset the flapper zapper 17 .
[0054] To initiate toilet bowl cleaning, the same action is taken by the operator as in a partial flush. The only difference is allowing the bowl water level to drop to the bottom of the bowl and then pulling cord pull knob 12 A, B, or C, and locking the cord 19 with sliding cord-lock 13 . Once cleaning is accomplished, the sliding cord-lock is reset and the pull knob 12 and cord 19 is pushed into a reset position allowing tank 39 , and bowl to come back to normal. A full flush may be necessary to remove the cleaning solutions and etc.
[0055] A toilet bowl overflow can be prevented after flushing by pulling the cord pull knob 12 A, B, or C which stops water flow to the toilet bowl and to the toilet tank 39 , preventing extensive damage to the flooring as well as leaving the operator with an unsightly mess to clean.
[0056] There will come a time that an old or warn-out flapper valve will start leaking and for various reasons can not be replaced soon enough. To stop or slow the leak, the operator simply pulls and holds the cords pull knob 12 A, B, or C all the way out and slides the sliding cord-lock 13 , against the flush handle 11 , or against the tanks side wall. This locks the cord 19 , and forces the flapper zapper 17 , against the flapper valve 16 . It then stands to reason that with the flapper zapper 17 , adding additional pressure along with the normal tank's water height pressure against the flapper valve 16 , the leak will surly slow or completely stop. This does not mean that the leaky and worn-out flapper valve 16 , shouldn't be replaced, and the sooner, the better.
[0057] An inherent operation this device offers right on the toilet tank 39 , is being able to stop the incoming water supply without having to rely on the standard plumber's shut-off valve in case of an emergency. In many cases it is hard to get to and at times it is seized (stuck open) and cannot be closed. Pulling on the cord's pull-knob 12 A, B, or C and locking it in place with the sliding cord-lock 13 , will lift the float 21 , on the water fill valve 22 which stops water flow to tank 39 , and forces flapper zapper 17 , to close flapper valve 16 , which stops water flow to the toilet bowl.
[0058] Another inherent operation this device does automatically is that it resets the flapper zapper 17 , each time the toilet is flushed if cord 19 is in a pushed-in or reset position. Flushing the toilet lifts the flapper valve 16 , which forces the flapper zapper 17 back into a normal reset position. Most importantly, with either the cord at flush handle 11 , or routed over the side of the toilet tank 39 , operations remain the same.
SCOPE
[0059] Accordingly, the present invention is directed to a cord configured to be pulled by the operator outside of a toilet tank that will stop water flow to the toilet tank and flow to the toilet bowl, allowing a full flush or a partial flush so that water conservation can be achieved.
[0060] In addition, extreme simplicity and practicality is the essence of this invention. It is another object and advantage of the invention to provide a control device which is useful both in new equipment and in retrofitting existing toilet structures so that a reliable and economic control device can be readily achieved in existing standard toilets.
[0061] It is another object and advantage of this invention to provide a device which is economic of construction, reliable in operation, easy to understand, and easily installed so that the water conservation advantages of the device can be widely enjoyed. Furthermore, the device has additional advantages in that;
it permits a means to ease toilet bowl cleaning by allowing the operator to empty the toilet bowl by just pulling the cord's pull knob after the bowl empties; it permits a means of preventing a toilet bowl overflow by allowing the operator to stop the flow of water to the toilet tank and water flow to the toilet bowl by pulling a cord that is routed to the outside of the toilet, either at the flush handle or on the side of the toilet tank; it allows an operator a means to slow or stop a flapper valve leak simply by pulling and locking the cord with a novel sliding cord-lock 13 stationed on the cord, thus allowing additional pressure against the flapper valve which slows or stops the leak; It permits the operator to have easy finger-tip access to a means of stopping water flow to the toilet in case of an emergency right on the toilet tank. Having to locate and then trying to close the plumbing's water stop valve can be very annoying; by pushing in or resetting the cord, a remarkable inherent result takes place. No matter which of the above operations it performs, the next flush resets the flapper zapper away from the flapper valve, thus not interfering with the next flush or operation picked by the operator.
[0067] These together with other objects of the invention, along with the various features of novelty which characterize the invention, are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of this invention, its' operation advantages and the specific objects attainted by its uses, reference should be made to the accompanying drawings and descriptive matter in which there are illustrated preferred embodiments of the invention. | A finger-tip access to a water saving retrofiable or original equipped device having a free traveling flexible cord routed from a toilet holding tank to inside non-frictional orifices located at strategic points on major toilet components, able to allow free water flow for full flushes or able to limit flow for partial flushes and stop or interrupt water flow for unusual or emergency functional operations such as toilet bowl cleaning, preventing a bowl overflow, slowing or stopping a flapper valve leak, or help prevent a drowning from occurring simply by pulling a cord. | 4 |
This is a National Stage Application of PCT/GB2009/001288 filed May 21, 2009, published as WO 2009/141622 A1, and claiming priority from GB0809252.0 filed May 21, 2008.
FIELD OF INVENTION
This invention relates to hyperspectral imaging of aquatic specimens and scenes.
BACKGROUND OF THE INVENTION
When viewing a scene using a traditional digital imaging sensor or by eye, the intensity of light from each point or pixel of the imaged scene can be determined for each of three wavelength bands (centred around red, green and blue for a digital camera, and yellowish-green, green and bluish-violet for the human eye). Information about the full spectral emissions (i.e. a continuous graph of intensity over wavelength) of the scene can, at best, be represented in only a three-dimension colour space, necessitating a loss of information.
Multispectral sensors have been used in research into aquatic (freshwater, brackish water and salt water) environments for about 30 years. Multispectral sensors are divided into more than three discrete colour bands and so give more detailed spectral information. They typically have a minimum wavelength resolution of 10 nm. They have typically been carried in satellites, aeroplanes, buoys and boats to analyse upwelling radiance remotely, and in underwater vehicles to measure both upwelling and downwelling radiance in situ. In both cases the light measured by the sensor comes from natural illumination that is incident on the water.
Hyperspectral sensors are also known. These have a much better wavelength resolution than multispectral sensors—at least 10 nm or better and can operate over a broad range of wavelengths including visible light and typically also into ultraviolet and infrared frequencies. It is also known to use hyperspectral sensors for imaging purposes in passive remote sensing. A hyperspectral imager (also known as an imaging spectrometer, imaging spectroscope, imaging spectroradiometer, superspectral or ultraspectral imager), is capable of determining the light intensity from each point or pixel of a scene for each of a large number (typically hundreds) of wavelength bands, each no more than 10 nm wide. This results in far more spectral information about the scene being preserved than is the case when just three bands are available, as for conventional imaging.
Because hyperspectral imagers give such detailed spectral information for each pixel in the image, independently of each other, it is possible to identify regions containing particular types of matter, such as chemical substances and organisms, by using their known unique spectra.
Applications for hyperspectral imagers include mineral exploration, agriculture, astronomy and environmental monitoring. They are typically used in aeroplanes (so-called “remote” viewing).
An overview of the use of hyperspectral sensors in oceanography is given is “The New Age of Hyperspectral Oceanography” by Chang et al. in Oceanography , June 2004, pp. 23-29. WO 2005/054799 discloses the use of a hyperspectral imager from airborne platforms to observe coastal marine environments remotely. The use of an airborne hyperspectral imager for mapping kelp forest distribution close to the shore is described in “Kelp forest mapping by use of airborne hyperspectral imager” by Volent et al. in Journal of Applied Remote Sensing , Vol. 1, 011503 (2007).
However, the applicant has realised that taking hyperspectral images remotely from the air or from space has several limitations. For example, even for very optically clear water, such as can be found in the Arctic, it is not possible to distinguish features of the sea bottom or of suspended matter beyond a depth of a few meters. In more typical marine waters, even this limited visibility is drastically reduced and is normally less than a meter or so—in murkier waters maybe only a few centimeters might be penetrable by light. This limits the usefulness of this technique. Additional problems occur due to interference from the air between the water surface and the remote imager; for example, due to clouds and to Rayleigh scattering. It is also necessary to take into account the angle of the sun in the sky.
BRIEF SUMMARY OF THE INVENTION
Furthermore, the spatial resolution of conventional remote sensing systems, such as a hyperspectral imager mounted in an aeroplane, is typically relatively low.
When viewed from a first aspect the invention provides an apparatus for placement on or in a body of water for hyperspectral imaging of material in the water comprising an artificial light source and a hyperspectral imager which are arranged so that in use light exits the apparatus beneath the surface of the water and is reflected by said material before re-entering the apparatus beneath the surface of the water and entering said hyperspectral imager, wherein said hyperspectral imager is adapted to produce hyperspectral image data having at least two spatial dimensions.
In accordance with the invention there is provided a new method and apparatus for aquatic hyperspectral imaging (optical measurements by using artificial light sources) which open up the possibility for wider and more accurate uses of hyperspectral imagers in underwater environments. Two-dimensional hyperspectral images of underwater material can be obtained from in situ apparatus; i.e. apparatus that is at least partially submerged. By having control of the light source, more accurate measurements of reflectance and transmission characteristics can be made, since there is no need to calibrate for solar angle above the horizon, and there are no atmospheric distortions to worry about. Moreover hyperspectral imaging can be carried out at any depth, rather than just at the surface as with remote sensing approaches.
Moreover by carrying its own artificial light source, the apparatus can be used to image material at much greater depths; either because it can be made bright enough to penetrate further, or because the apparatus itself can be submerged to the required depth. A further advantage given by the on-board light source is that the emission spectrum of the light source can be chosen or tailored to the reflectance spectrum of the material being looked for or expected and the optical properties of the water. These optical properties are affected by coloured dissolved organic matter, suspended matter, phytoplankton etc. Thus if a particular material is being searched for, the light source can be chosen to ensure that it is illuminated by all the desired wavelengths corresponding to peaks in its reflection spectrum. Equally the appropriate light source can be chosen absorption and scattering properties of the water in which the unit is operating can be
For example an apparatus in accordance with the invention, such as an autonomous underwater vehicle (AUV), remotely operated vehicle (ROV), could be provided with a plurality of light sources. Each light source could be used in different conditions or when looking for different materials; or indeed they could be blended together in varying proportions to give further lighting options.
Indeed in a set of preferred embodiments the apparatus comprises means for adjusting the spectrum of light emitted by the light source or by a plurality of light source. This allows the possibility of “tuning” the overall spectral output of the light source(s) as needed. This could be an adjustment made for each mission or could be adjusted dynamically—either manually or under programmed or feedback control. For example a calibration surface having known reflectance characteristics could be deployed and feedback control used to alter the output spectrum depending on the spectrum of the light reflected from the calibration surface until a desired spectrum is achieved. A non-limiting example of such a calibration surface is a white Teflon® (polytetrafluoroethylene) disc deployed in front of the hyperspectral imager at a given distance.
The hyperspectral imager could though be calibrated using other instruments such as a (non-imaging) spectroradiometer, spectrophotometer or a spectrofluorometer. The apparatus may comprise further instruments such as a spectrophotometer, a spectrofluorometer, an acoustic Doppler current profiler (ADCP), a chlorophyll fluorescence sensor (passive Ch 1 a fluorometer (no artificial excitation light source), blue excitation light stimulated Ch 1 a fluorometer or LED laser Ch 1 a fluorometer), a coloured dissolved organic matter (cDOM) sensor, a backscattering meter, a turbidity meter, a temperature sensor or a salinity meter. Determinations from these other instruments may be used to adjust the output of the hyperspectral imager and/or the light source.
In one example the spectrum adjusting means could comprise one or more optical filters selectably placeable in the path of the emitted light. Preferably more than one filter is available, each filter having a unique spectral-filtering characteristic. Alternatively or additionally the light source may comprise a plurality of light-emitting elements each with differing emission spectra, the spectrum adjusting means comprising means for altering the power supplied to respective elements in order to give a required overall output spectrum. The light emitting elements could comprise light emitting diodes (LEDs). The LEDs could emit light substantially at a single-frequency—e.g. red, green or blue light—or could contain phosphors that emit light across a range of frequencies—e.g. white light. A mixture of coloured and white LEDs could be employed.
It is important to note that the present invention is not concerned with simple hyperspectrometers (e.g. spectroradiometers) providing a spectral analysis of effectively a single light beam travelling along a single path. A hyperspectral imager on the other hand can produce a two-dimensional representation of a scene containing hyperspectral information for each of many points across the scene.
The addition of spatial dimension information over simple hyperspectral sensor output data, allows hyperspectral imagers to be used in a wide variety of applications. In general it allows the identification of underwater material of interest in situ in an aquatic environment (bio-geo-chemistry). This can have many useful applications such as enhanced environmental monitoring; developing theme-maps of materials of interest that are geolocalized and have a time tag; creating a time-series of hyperspectral images of a region including a given material of interest; monitoring and surveillance of materials of interests in a given region; identification of unusual activities (e.g. mass occurrence of a given organism, planktonic or benthic; oil leakage; leakage of other minerals/chemicals; metal disintegration).
The hyperspectral imager could, for example, use dispersive spectrography (DS), Fourier transform spectrography (FTS) or Hadamard transform spectrography (HTS). Dispersive spectrography generates a spectrum by optically dispersing incoming radiation according to its spectral components while FTS and HTS use the Michelson interferometer principle to generate a spectrum by modulating incoming radiation in the time domain through interference by use of moving mirrors or a Hadamard array respectively; the modulated radiation in the time domain is then Fourier transformed into spectral components. Preferably the imager uses dispersive spectrography; this reduces the need for moving parts and permits a compact, robust and low-cost construction with relatively low power consumption, and good resistance to the low temperatures that may be experienced underwater. Preferably the imager operates using the push-broom technique. Preferably movement of the whole apparatus (e.g. forward motion of an underwater vehicle) enables an area of interest to be continuously imaged; this contrasts with FTS and HTS approaches in which separate, discrete images would need to be formed and then assembled to image a large area. Preferably it has no independently moving parts; this contrast with FTS which requires a moving mirror and HTS which requires a moving grating or mask.
The apparatus could be tethered to a ship or other vessel. Such a tether could comprise an umbilical power supply. Alternatively and preferably the apparatus could move independently; e.g. it might comprise a portable power supply such as batteries or means for generating its own power. Whether tethered or untethered, control of the apparatus could be exercised from a support vessel, or even from land, or the apparatus could be completely autonomous. In some preferred embodiments the apparatus is not physically connected to any above-surface apparatus, and comprises a battery power supply, which may be lead-acid or nickel-based, but is preferably lithium-based so as to be relatively compact and light-weight. Alternatively or additionally, the apparatus may comprise any other suitable power supply such as a combustion engine, a nuclear reactor, or a capacitor (e.g. a super capacitors).
The apparatus preferably comprises image capture means, such as a digital video camera, for capturing frames from the hyperspectral imager for subsequent analysis; it may additionally or alternatively comprise image processing means arranged to process captured images from the hyperspectral imager; it may, for example, be arranged to compile time-sequential frames into a representation of a scene.
The apparatus could be a floating vessel. In a set of preferred embodiments however it is adapted to be fully submersible. Embodiments of the invention comprise a housing made substantially of metal, e.g. aluminium or marine steel. In a preferred set of embodiments part of the housing or hull is transparent to permit the exit and entrance of light from/to the light source and imager. For example it could comprise one or more transparent panels, e.g. made of soda glass, quartz, acrylic glass or other suitable material. In some embodiments, the entire housing could be constructed of transparent material.
Alternatively the light source and/or hyperspectral imager (or at least an optical part thereof) could be provided in a separate pod attached to the rest of the vessel.
The housing is advantageously designed to withstand external pressures of at least 2 bars; preferably at least 10 bars; and possibly at least 100 bars. In some embodiments where a vessel in accordance with the invention is required to be used in the very deepest parts of the ocean it may be necessary for the housing to withstand pressures of the order of 1000 bars.
The invention also extends to a method of generating hyperspectral images. When viewed from a further aspect, the invention provides a method of imaging material beneath the surface of a body of water comprising:
illuminating said material with an artificial light source from beneath the surface of the water; receiving from beneath the surface of the water light reflected from said material into a hyperspectral imager; and said imager generating hyperspectral image data from said material, said image data having at least two spatial dimensions.
Preferably the apparatus is as described in accordance with the first aspect of the invention. Preferably the artificial light source is provided in the same unit, such as a vessel or underwater platform, as the imager. It is envisaged however that it could be provided on an attached unit, or even a separate, unconnected unit.
In a set of embodiments the method comprises the further step of adjusting the output spectrum of the artificial light source. In some embodiments the hyperspectral imager is used to determine whether a desired spectrum for the artificial light is achieved. The method may comprise the further step of locating a spectral filter in the path of the artificial light; it may also or instead comprise the step of selectively illuminating elements from among a set of spectrally-distinct light-emitting elements.
In a set of preferred embodiments the apparatus is used to locate or map the extent of one or more organisms or other material by the characteristic spectral fingerprint(s) thereof. However this relies on these spectral fingerprints being known. The spectral fingerprints might be obtainable from an existing library, database or other source. However in a preferred set of embodiments a library is built up or extended by using a hyperspectral imager to obtain a spectral profile of a specimen (object of interest). That specimen can be identified by other means—e.g. visually by an expert or by independent analysis—and the profile associated with the identity of the material. In some preferred embodiments, a combination of analysis methods are used to build up the database; especially preferred is to use a hyperspectral imager in combination with high-precision liquid chromatography (HPLC) and/or liquid-chromatography mass spectrometry (LC-MS). These latter techniques are preferably used to isolate and characterise a substance (e.g. molecules) that contributes to an optical signature for a specimen. For example, HPLC may be used to characterise optically different types of chlorophylls and/or carotenoids.
This is considered to be novel and inventive in its own right and thus when viewed from a further aspect, the invention also provides a method of identifying an underwater material comprising:
analysing a specimen of a material extracted from a body of water using a hyperspectral imager to determine a hyperspectral profile of said material and storing said hyperspectral profile; taking an image of an underwater scene in a body of water using said hyperspectral imager or a further hyperspectral imager; generating an observed hyperspectral profile from said scene; and comparing said observed hyperspectral profile with said stored hyperspectral profile to identify said material and recording a positive identification if the comparison is sufficiently close.
Thus it will be seen by the person skilled in the art that underwater material can be identified based on a prior analysis of a sample of that material. The specimen may, for example, be a mineral; a protein; a pigment; oil; a metal (e.g. copper, iron); disintegrating metal (e.g. rust); a bacterium; a eukaryote; a marine invertebrate; a marine vertebrate; microphytobenthos; macrobenthos; a benthic filter feeder; a phytoplankton; a zooplankton; a larva; a fish; kelp; an alga; sediment; a biological mat (bacteria and microscopic eukaryotes covering sediments); a hydrocarbon; vegetation; wood; an artefact (e.g. a ship-wreck or a lost item); a hydrothermal vent; a cold seep; or a plurality, or any combination, of the above.
Imaging may be conducted near the water surface, within the water column or on the bottom, both for marine and fresh water.
Once reflectance, R(lamda), and/or transmission, T(lamda) (where lamda is the wavelength of light) characteristics are obtained for an object of interest, preferably embedded in water to mimic natural conditions, this information can further be used to calibrate and compensate for the effects of optical path length in water masses of different types (e.g. case I and II waters where the content of phytoplankton, coloured dissolved organic matter and suspended matter needs top be adjusted for since they will alter the spectral characteristics of the emitted light to the hyperspectral imager due to different spectral attenuation coefficients, K(lambda), in the water).
Measurements of R(lamda) from a given object of interest made under controlled conditions may be used to adjust for the optical path length (distance from the light source to the object and back to the hyperspectral imager) and/or to determine optical characteristics of the intervening water.
Preferably the apparatus comprises an optical sensor and means for estimating a spectral attenuation coefficient of the ambient water using an output from said optical sensor. Preferably such estimations are made continually or continuously. Preferably these estimations are used to adjust the output of the artificial light source; e.g. to tune the spectral output of one or more lamps (LED, halogen, HID, etc.) so that a predetermined light spectrum will be received at a target object and/or to compensate for the attenuation of reflected or emitted light returning to the apparatus. The predetermined light spectrum may be a substantially uniform energy across the visible spectrum e.g. 400-700 nm (i.e. white light), or it may be of any other appropriate shape.
Preferably the method comprises the step of storing said hyperspectral profile in a database of hyperspectral profiles. Preferably the method then also comprises the step of retrieving the hyperspectral profile from the database. This allows, for example, entirely new chemical species and/or biological entities, previously unknown to man, to be highlighted as they will not be found to be in the database of known substances. Such discoveries may have applications to the food, energy and pharmaceutical industries (e.g. bio-prospecting), among others.
Preferably the same hyperspectral imager, or one with the same optical characteristics is used. In this way, no correction for optical artefacts unique to a particular imager is required.
Preferably the step of taking an image of an underwater scene comprises use of apparatus according to the first aspect of the invention.
Data are preferably stored on a hard disk. Analysis of the data may be performed; e.g. discriminant analysis, principal component analysis, standard error of replicate measurements, or mean coefficient of variation. The step of recording a positive identification could comprise displaying on a display or storing in a volatile or non-volatile memory or other digital data storage medium.
Preferably the step of analysing comprises using the hyperspectral imager in an apparatus comprising an objective lens, e.g. by coupling the hyperspectral imager to a microscope. Preferably the specimen is submerged in liquid, preferably water, preferably seawater. Many materials and objects, including aquatic specimens such as algae, have different spectral characteristics when they are in water compared with in air. There are therefore significant advantages in analysing them in a liquid.
It will be appreciated that, in addition to having advantageous optical effects (e.g. no reflected light from light source, imitating the spectral characteristics of the object of interest in situ under controlled conditions in the laboratory), the apparatus of this aspect of the invention allows controlled measurements in the laboratory of marine organisms of different taxa to be taken in vivo (i.e. with the specimen alive and in good shape). Nonetheless, it may be desirable on occasions to generate hyperspectral images of specimens that are dead or decaying.
The apparatus may further comprise additional means for determining in vivo spectral absorption or fluorescence excitation spectra; or for performing high precision liquid chromatography (HPLC), liquid chromatography mass spectrometry (LC-MS), or nuclear magnetic resonance spectroscopy (NMR). These additional means may facilitate the isolation, identification, characterisation and quantification of entities such as pigments or other bio-molecules or bio-active molecules; this information may subsequently be used for in situ underwater bio-prospecting of substances of interests (e.g. bioactive substances). It may thereby be possible in situ to identify an object of interest and also to determine its optically-active chemical composition.
For example, a mat of cyanobacteria on a seafloor may give an hyperspectral image reflectance drop at 440, 490, 545 and 680 nm. From previous HPLC analysis it is known that the 440 and 680 nm peaks are related to the absorption peaks of Ch 1 a; the 490 nm peak corresponds to zeaxanthin; and the 545 nm peak corresponds to phycoerythrin. If some of the pigments were unknown, subsequent analysis could be performed using LC-MS to find the molecular weight of the given compound; this would allow it to be characterised and added to the database.
This is considered to be novel and inventive in its own right and thus when viewed from a further aspect, the invention also provides a method of identifying an underwater material comprising:
taking an image of an underwater scene in a body of water using a hyperspectral imager; generating an observed hyperspectral profile from said scene; and using a database to compare said observed hyperspectral profile with a stored optical profile to identify a molecule and recording a positive identification of that molecule in the scene if the comparison is sufficiently close.
The molecule may be a pigment such as a chlorophyll, carotenoid, phycobiliprotein or axylene. Preferably a plurality of different molecules are identified in the scene and preferably the method further comprises the step of identifying said material from said identification of the molecule(s).
In any of the foregoing aspects, the hyperspectral imaging component is preferably arranged to distinguish between wavelengths to a resolution finer than 10 nm; more preferably between 0.5 and 2 nm; and most preferably finer than 1 nm; e.g. 0.5 run. Advantageously, the spectral resolution of the imaging component is adjustable; preferably while the apparatus is deployed. Thus the spectral resolution can be set to match the prevailing conditions, noting that the signal-to-noise ratio may be improved if the spectral resolution is made coarser. For example in murky waters or when imaging far-away objects, the spectral resolution may be made coarser to, say, between 5 and 10 nm, so as to enhance the signal-to-noise ratio (at the expense of spectral resolution). The hyperspectral imaging component is preferably arranged to image over the whole spectrum of visible light; e.g. 400-700 nm. It may alternatively or additionally be arranged to image outside the visible spectrum; e.g. at wavelengths below 400 nm and/or above 700 nm.
The hyperspectral imaging component preferably has a maximum dimension less than 1 meter and more preferably less than 50 cm; e.g. between 20 and 30 cm. Preferably it has a second-largest dimension less than 50 cm; more preferably less than 10 cm; e.g. approximately 5 cm. The person skilled in the art will appreciate that this is considerably smaller than many previous hyperspectral imagers; this allows the present imaging component to fit into commercially-available UUVs, AUVs, underwater gliders and ROVs.
The hyperspectral imaging component of the present invention is preferably also under 5 kg in weight; more preferably under 1 kg; e.g. between 500 and 1000 g. It preferably has a power consumption of less than 10 W; more preferably less than 5 W; most preferably less than 2 W.
When viewed from another aspect the invention provides an apparatus for imaging a specimen comprising an objective lens, a hyperspectral imager in optical communication with said lens, a vessel suitable for holding a specimen in liquid such that at least a part of said specimen is situated in the focal plane of said lens.
The invention extends to a method of imaging a specimen immersed in liquid in a container using a hyperspectral imager.
Thus it will be seen that an apparatus is provided which may be used in a laboratory situation to analyse samples in a fluid using a hyperspectral imager. As above preferably the liquid is water such as seawater.
The specimen could be static during the analysis. Preferably however the apparatus comprises means operable to move said vessel relative to said lens in a direction parallel to said focal plane. This allows a hyperspectral image with two spatial dimensions to be built up. This might be useful for example in establishing an area of an object comprising a certain material and obtaining an averaged hyperspectral profile across that area. Thus a preferred method comprises moving the specimen relative to an objective lens of said imager in a direction parallel to the focal plane of the lens and forming a two-dimensional image of the specimen.
Preferably the apparatus comprises an artificial light source e.g. a halogen, xenon, metal halide (HID, light arc) lamp. The advantages of an artificial light source are discussed above in relation to the first aspect of the invention. Light from the light source may be directed onto or through the specimen by optical diffusers, optical fibres and/or mirrors. The apparatus may be arranged to generate images using light reflected from the specimen, or light transmitted through the specimen, or both.
There may be an air gap between the front of the objective lens and the surface of the fluid, but preferably the objective lens is at least partially immersed in the fluid. Thus optical interference due to the light passing through air between the fluid surface and the objective lens is avoided.
Preferably this method uses apparatus as set out in the preceding aspect of the invention.
Various aspects and features of the invention have been set out above. Features described with reference to one aspect should not be understood as being limited to that aspect only, but rather as also being applicable to any of the other aspects where appropriate.
Certain preferred embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic, perspective drawing of the principle components of a hyperspectral imager as used in embodiments of the invention;
FIG. 2 is figurative diagram showing a vertical cross-section through an underwater vehicle embodying the invention;
FIG. 3 is a perspective drawing of the exterior of an underwater hyperspectral imager embodying the invention;
FIG. 4 is a perspective drawing of a light source for use with embodiments of the invention;
FIG. 5 is a perspective view of a hyperspectral microscopic imager in accordance with the invention; and
FIG. 6 shows the analysis of a specimen of a red alga using a magnifying hyperspectral imager in accordance with the invention.
DETAILED DESCRIPTION OF INVENTION
First an example of the use of a hyperspectral imager to form an image having two spatial dimensions will be described with reference to FIG. 1 . FIG. 1 shows how light passes from a scene 2 through the optics of a push-broom hyperspectral imager during the capture of a single frame. Only a thin strip 4 of the scene is imaged during each time frame, extending in the direction of the Y axis and having width ΔX. Light from the scene first passes through an objective lens 8 which focuses it through an entrance slit 10 . The slit excludes light other than that emanating from the strip 4 . Its width is set to relate desired width ΔX to the width of a single row of pixels of a CCD image sensor 18 . A collector lens 12 then directs light through a grism 14 , which is a combination of a grating and a prism arranged to create a dispersed spectrum. The spectral dispersion occurs over the X axis, orthogonal to the spatial dimension Y of the strip 4 . A camera lens 16 then focuses the spectrally dispersed light onto a CCD image sensor 18 .
In order to build up an image of a two-dimensional scene, the objective lens 8 and other optics are, over time, moved laterally relative to the scene 2 in the direction of the X axis. The speed of motion is determined such that each sequential frame captures a strip 4 of the scene along the Y axis immediately adjacent the preceding strip. The sequential frames can be processed and composed to generate a hypercube. If desired, this hypercube can be used to generate two-dimensional flat greyscale images indicating light intensity at each pixel for a given single optical wavelength range. The wavelength resolution of the apparatus is determined by the number of pixels on the CCD sensor 18 in the direction of the X axis.
FIG. 2 shows an autonomous underwater vehicle (AUV) 20 according to an embodiment of the invention in a body of water 22 above a seabed 24 . A suitable AUV is the REMUS developed by the Woods Hole Oceanographic Institution. The AUV 20 comprises a tail section 26 containing the propulsion motor and controller circuitry for a propeller 28 . A mid-body section 30 houses various operational components of the vehicle. Between the mid-body section 30 and a nose cone 32 is an optics section 34 . The optics section 34 comprises a watertight chamber carrying a hyperspectral imager and a light source (not shown). A transparent outlet window 36 allows light 40 from the light source to emerge towards a scene of interest, such as the seabed 24 . Light 42 returning from the scene enters through a transparent inlet window 38 behind which is located the objective lens 8 of a hyperspectral imager.
FIG. 3 shows another embodiment of an underwater apparatus 44 embodying the invention. This apparatus 44 is not self-propelling but rather can be lowered into the water attached to a floater and so be immersed in the water for towing by a boat for example, or carried by a human diver. It comprises a watertight housing 46 made of aluminium or marine steel having a transparent window 48 made of soda glass or quartz to allow the passage of light into, and optionally out of, the imager 44 . It also has a display panel 50 for turning the system on and off, tuning the frame, gain, iris and gamma controls. Inside the housing 46 , there is a hyperspectral imager, batteries and video recorder and there may be one or more lamps. The apparatus 44 may also carry external underwater lamps (not shown) such as an Underwater Kinetics Light Cannon 100 , which can be used to obtain 6000 degrees Kelvin colour temperature. The imager can be used in any orientation; i.e. it can be pointed horizontally, up or down.
In both cases above the apparatus could carry several lamps which can be used individually or in combination to provide a customised illumination. This can be used to minimise the effects of absorption and scattering in the water between the light source, imaged material and the imager, and can also ensure that the correct wavelengths in the imaged material are excited.
The lamp 52 shown in FIG. 4 is also suitable for use with imagers embodying the invention, such as those of FIGS. 2 and 3 and takes the idea of blending light sources one step further. The lamp 52 comprises a plurality of light emitting diode (LED) lamps 54 which can be selectively illuminated. Some of the LEDs are white, emitting light in the range 350-800 nm. Others are blue (emitting light in 400-500 nm range), green (500-600 nm), and red (600-700 nm).
The spectrum of light emanating from the lamp 52 can be tuned by selecting which LEDs to activate, depending on the optical properties of the water (which vary with distance to the target object due to the spectral attenuation coefficient of water, and which can vary due to optically-active components such as phytoplankton, coloured dissolved organic matter and total suspended matter).
Either of the two underwater apparatus described above can be used to capture and record two-dimensional hyperspectral images beneath the water. By carrying its own artificial light source, the imaging apparatus can measure much more accurate hyperspectral information than is possible using airborne remote sensing. For example the effects of solar horizontal, and of atmospheric scattering and distortion are removed. Moreover the path length of the emitted and reflected light through the water can be relatively short, whatever depth the imaged material is at.
One application of the principles of the invention is in mapping or prospecting for materials by using a database of spectral profiles that correspond to known materials such as particular compounds, substances or organisms to compare against the spectral profiles measured from the captured images. The spectral profiles on the database might be commercially or publicly available. However below a method of building up or adding to such a database will be described.
FIG. 5 shows a hyperspectral microscopic imager 56 for use in the method mentioned above forming an embodiment of another part of the invention. The imager 56 comprises a microscope component 60 , adapted from a conventional optical microscope, such as a Leitz Leca MS5 microscope (1-80x), and a hyperspectral imaging component 58 , such as an Astrovid StellaCam II Video Camera [AV-STCA2] with a pixel array of 640×480, containing optics as described with reference to FIG. 1 . The objective lens of the hyperspectral imaging component 58 may, by way of example, have a focal length of 25 mm and f:1.6.
The hyperspectral imaging component 58 has an image capture means; for example an ARCOS pocket video recorder AV400 capturing AVI video at 25 frames/sec. In one example, each video frame recorded (spectral profile), consists of the light spectrum from 363 to 685 nm dispersed over 640 pixels, giving a resolution of 0.5 nm/pixel. The spatial resolution perpendicular to the moving direction in this example is 193 pixels.
The imager 56 further comprises a moveable platform 62 , which can be moved in the direction indicated by the arrow by a stepper motor located underneath the platform. By way of example, the stepper motor may have a gear exchange of 1:500 giving a speed of 2.59 mm/sec. The platform 62 carries a watertight sample container 64 , such as a Petri dish, which can hold a specimen in a volume of liquid. The container 64 is also arranged to direct light through a specimen from beneath, for example by means of a mirror and a diffuser, when determining optical transmission characteristics of a specimen; or with a light source above for determining optical reflectance. The imager 56 also comprises one or more light sources directable onto the upper surface of a specimen, preferably from an off axis angle such as at 45 degree to the vertical. The same light source may be used for either transmissive or reflective analysis and may consist of a halogen or other light source directed appropriately through two fibre optic bundles. This light source can be used when determining the reflectance characteristics of a specimen. The objective lens of the microscope component 60 may be lowered into the fluid carried in the sample container 64 , to mitigate any optical interference that might be caused due to the fluid-air and air-lens boundaries when the objective lens is located out of the fluid.
In use, a sample is placed in fluid; such as sea water, in the sample container 64 . The stepper motor moves the platform 62 in the direction of the arrow while the hyperspectral imaging component 58 captures sequential spectral image strips across the specimen orthogonal to the direction of motion. These strips can be combined as explained above with reference to FIG. 1 . In particular, processing may be performed using YaPlaySpecX software (Fred Sigemes, UNIS, cf. Sigemes et al. 2000 Applied Optics) to compose monochromatic images from an AVI video, forming an spectral image cube. Depending on the light source selected, two- dimensional images of either spectral transmittance or spectral reflectance of the specimen in the liquid can be generated at high magnification through use of the imager 56 .
If desired, average spectral characteristics (with statistical information on e.g. error estimates) for an area of interest captured with the hyperspectral microscopic imager 56 , can be found by averaging information from an image hypercube in the spectral direction. The average spectral characteristics measured for reflection, E r (lamda) (mW/nm), or transmission, E t (lamda) (mW/nm), may be adjusted for the halogen lamp (or other light source) radiant intensity spectrum for reflection, E hr (lamda) (mW/nm), and for transmission, E ht (lamda) (mW/nm), to give a comparable reflectance or transmittance spectrum with optical density. The dimensionless reflectance spectra is then R(λ)=E r (lamda)/E hr (lamda) and the dimensionless transmittance spectra is T(lamda)=Et(lamda)/E ht (lamda).
FIG. 6 shows an image A of a specimen of a red alga to be analysed using a magnifying hyperspectral imager in accordance with the invention. It also shows a magnified monochromatic image B of the specimen in water (at 600 nm wavelength) captured using the hyperspectral imager. Three distinct regions 1 , 2 , 3 are indicated, for which the average reflectance, R(lamda), over the region is to be determined. FIG. 6-C shows the R(lamda) spectra 1 , 2 , 3 obtained. It also shows the corresponding spectral absorbance spectrum OD, measured with a spectrophotometer, which validates the reflectance measurements (they should be inversely related). The reflectance measurements have been adjusted to compensate for the halogen lamp radiant intensity spectrum, E h (λ).
Once an averaged spectrum for a region of interest has been obtained, this can be used to identify other instances of the same material in other situations; in particular, it can be used with the apparatus described earlier to identify the same material underwater using in situ hyperspectral imaging apparatus. | An apparatus for placement on or in a body of water for hyperspectral imaging of material in the water comprises an artificial light source and a hyperspectral imager. These are arranged so that in use light exits the apparatus beneath the surface of the water and is reflected by said material before re-entering the apparatus beneath the surface of the water and entering the hyperspectral imager. The hyperspectral imager is adapted to produce hyperspectral image data having at least two spatial dimensions. | 6 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a divisional of co-pending U.S. application Ser. No. 14/479,535 filed Sep. 8, 2014, which is incorporated by reference herein.
BACKGROUND
[0002] The present invention relates to hydraulic valves and more particularly to valves typically utilized to control fluid flow in a toilet tank.
DESCRIPTION OF THE PRIOR ART
[0003] Hydraulic valves have long been employed to control flow of liquid such as in a toilet tank. These valves often rely on buoyant floats for actuation to turn the incoming water off when the water reaches a predetermined level and to turn the water back on when a flush handle has been actuated to exhaust the fluid from the tank into the toilet bowl. An example of these types of valves and arrangements is shown my U.S. Pat. No. 6,712,090.
[0004] Many efforts have been made over the years to improve the construction of these valves, often referred to as ball cock valves and even to lock the valves against opening except when toilet has been flushed.
[0005] As disclosed in my prior U.S. Pat. No. 6,712,090, existing ball cock valves, in some instances, incorporate a valve body which sits on an upright supply pipe to control flow from the outlet at the top of the pipe via a flexible diaphragm which may be raised and lowered to open and close such outlet. It has been common practice for such diaphragms to incorporate a central vertical pilot passage which receives a vertically elongated pilot pin or stem having longitudinally spaced apart, diametrically enlarged cross sections spaced for selective registration with respective reduced-in diameter ports spaced along the length of the pilot passage for selectively blocking flow through the annulus formed between such enlarged cross sections and ports. When the enlarged sections are out of registration with the respective ports, water may flow upwardly through the pilot passage to pressurize the topside of the diaphragm to force it down into engagement with a seat formed at the pipe outlet to thereby block flow. A lever arm is pivotally mounted at one end to engage the pilot pin medially for raising and lowering of the pilot pin in response to raising and lowering of a donut shaped float mounted concentrically about the feed pipe to selectively control flow through the pilot passage.
[0006] While a significant improvement over the art at the time, this prior construction can sometimes suffer the shortcoming that stopping of flow through the pilot passage is dependent on registration of the enlarged sections with the respective ports and, over time, one or the other may be damaged or worn to the point where positive registration for control of flow is no longer effective. Further, the annuli between the pilot pin and ports in the passage provides for direct flow from the inlet pipe into the pilot passage and, with the relatively low volume of flow which can carry sediment, scum or residue, the annuli may become plugged or clogged.
[0007] Another example of a pilot valve construction for a ball cock assembly is a pilot pin carried from one end of a lever arm mounted pivotally to a pivot pin and projecting through an aperture in a seal element to be formed on its lower extremity with an enlarged bulbous portion apparently intended to be, when the valve is closed, engaged with the lower surface of the seal element to block flow there-through. A device of this type, while in theory providing for some degree of control for the seal to close off the water inlet, fails to provide for positive exhausting of fluid above the seal element in a manner which will result in positively releasing pressure above the seal element for raising thereof and, further, fails to provide for diverting the water during inlet flow in a positive manner to direct any sediment in such water away from the central underside of the seal element in a manner which will serve to minimize the tendency for such sediment to be directed into the pilot passage.
[0008] One commercially available ball cock valve is marketed under the mark FLUIDMASTER® and is well known in the field. Systems employing valves of this type, while popular in the marketplace, often incorporate a great number of parts, in some instances over 40, thus making them expensive to manufacture and requiring some degree of skill to assemble and install.
SUMMARY OF THE INVENTION
[0009] The present invention includes an upright inlet pipe terminating at its upper extremity in a housing defining a chamber sitting over an inlet port for introduction of water. A flexible valve diaphragm is received in a chamber above an inlet port and includes a central, through, pilot passage which receives a pilot pin disposed longitudinally therein and including enlarged portions to be aligned with respective ports spaced along the passage. The enlarged portions are formed with a peripheral fluted areas for escape of pilot control fluid. The pilot pin projects below the lower surface of the diaphragm and is formed with an enlarged poppet which, upon raising of the pin within the passage, serves to abut a valve seat formed on the underside of such diaphragm to close flow in the passage to thereby decrease the pressure on the top side of the diaphragm causing the water pressure on the underside to raise the diaphragm for flow of water from the inlet port outwardly into the toilet tank.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a front view, partially broken away, of a toilet storage tank which incorporates the improved flow control valve of the present invention;
[0011] FIG. 1 A is a partial perspective view, in enlarged scale, of the upper portion of a control tube included in the catch device shown in FIG. 1 and depicting the control valve being installed;
[0012] FIG. 1 B is a perspective view similar to 1 A but showing the control valve fully installed;
[0013] FIG. 2 is an exploded, vertical, sectional view, in enlarged scale, of an inlet pipe device and the control valve shown in FIG. 1 ;
[0014] FIG. 3 is a vertical, sectional view similar to FIG. 2 but in enlarged scale and the components assembled;
[0015] FIG. 4 is a vertical, sectional view, in enlarged scale, of the upper portion of the flow control valve shown in FIG. 3 ;
[0016] FIG. 5 is a vertical, sectional view, in enlarged scale, of the lower portion of the inlet pipe device shown in FIGS. 2 & 3 ;
[0017] FIG. 6 is a partial vertical sectional view, in enlarged scale and partially broken away, of the flow control valve shown in FIG. 4 and depicting the valve in its closed position;
[0018] FIG. 7 is a vertical, sectional view similar to FIG. 6 but showing the flow control valve in its open position;
[0019] FIG. 8 is a vertical, sectional view, in enlarged scale, of the catch device shown in FIG. 3 and depicting a catch device blocking downward travel of a float tube device controlling the control valve shown in FIG. 7 ;
[0020] FIG. 9 is a vertical, sectional view, similar to FIG. 8 but showing the catch device released;
[0021] FIG. 10 is a transverse, sectional view, in enlarged scale, of a locking flange incorporated in the catch mechanism shown in FIG. 9 ; and
[0022] FIG. 11 is vertical, sectional view, partially broken away, of a second embodiment of the flow control device shown in FIG. 2 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0023] Referring to FIG. 4 , the control valve 13 of the present invention has utility for mounting on top of an upright inlet pipe device 15 which includes an outlet 17 surrounded by an upwardly facing valve seat 19 ( FIGS. 6 and 7 ) against which a diaphragm 20 will seat when a pilot valve 23 is opened. The diaphragm 20 is formed with a central structure defining an axial pilot stem passage 26 ( FIG. 7 ) formed with a pair of reduced-in-diameter, vertically spaced apart ports 27 and 29 with which respective enlarged portions 33 and 35 of a valve stem 37 are selectively registered. The passage terminates at its bottom end in an inlet port surrounded by a downwardly facing pilot valve seat 28 . The valve stem 37 projects downwardly below the port pilot seat 28 ( FIG. 7 ) and is formed with an enlarged poppet 41 configured in its lower portion with downwardly facing upwardly and radially outwardly angled deflecting surfaces 60 , ( FIG. 7 ) to deflect upwardly flowing, incoming water to flow radially outwardly as it passes the poppet. The stem 37 is controlled by a control lever 42 having a projecting extremity 43 controlled by a concentrically disposed cylindrical control tube 51 encircled and carried, by a donut shaped float 47 .
[0024] Thus, when the float 47 is lowered, the projecting extremity 43 of the lever arm 42 will be lowered thereby raising the pilot stem 37 to raise the poppet 41 to seat against the seat 28 on the underside of the diaphragm 20 ( FIG. 7 ) to block flow of water upwardly through the passage 26 to thereby allow for pressurization of the underside of the diaphragm as shown in FIG. 7 to raise the diaphragm off its seat 19 thereby allowing flow of water up through the passage 87 defined by the upper extremity if the pipe device to flow outwardly into the toilet tank and bowl as will be described below.
[0025] As will be appreciated by those of skill, lowering of the float may be selectively restricted to prevent the pilot valve 23 from opening the control valve 13 . Referring to FIG. 1 , control of the pilot valve 23 to control flow from the inlet pipe device 15 may be via the concentric control tube 51 . The inlet pipe device is typically disposed spaced laterally from a flapper flush valve 53 .
[0026] Referring to FIG. 8 , a catch device, generally designated 55 , is disposed on the side of the fill pipe facing the flush valve and, in the preferred embodiment, is formed by a generally hairpin shaped somewhat stiff but resilient spring wire 57 mounted medially from a mount device 58 which may include a radially projecting hinge arm 59 constructed of elastomeric material such as flexible rubber to provide for rocking or slight rotation of such catch device about the arm. Carried at the upper extremity of the catch device is a keeper 61 to be selectively disposed in the downward path of the control tube 51 to block the downward path thereof ( FIG. 8 ). The lower extremity of the catch device 55 is connected with the flush control lever 75 by means of a link 65 such that, when the flush control lever is actuated, the catch device is rotated a few degrees counterclockwise on the hinge arm 59 , as viewed in FIGS. 1 and 9 , to move the keeper 61 to the left out from under the bottom edge of the control tube 51 thereby freeing the tube to lower as the water in the tank is lowered to thereby rotate the lever arm 42 counterclockwise as viewed in FIG. 7 to open the flow control valve 13 . Concurrently, the lever arm will lift the free side of the flapper valve 53 to flush the water from the tank into the bowl.
[0027] On the other hand, should the water level in the tank 71 be lowered, by a leak, from the level shown in FIG. 1 without actuation of the flush lever, the keeper 61 will remain positioned in the path of the control tube 51 ( FIG. 8 ) to prevent lowering thereof to retain the pilot valve 23 open and the flow control valve closed ( FIG. 6 ).
[0028] Referring to FIGS. 1 A and 1 B, the control tube 51 may be constructed of plastic and the upper extremity thereof formed at one diametrical side with a pair of annularly spaced apart, longitudinal slits 126 defining there-between a narrow, upwardly projecting resilient tongue 128 formed at its free extremity with the bore 129 . In this manner, when the control valve is installed, the distal extremity 43 of lever arm 42 will ride downwardly on the inner surface of the free extremity of the tongue 128 to drive the free end radially outwardly, as it is viewed in FIG. 1 A, until the bore 129 is registered with the lever arm for projection into such bore as shown in FIG. 1 B allowing the tongue to snap back into its neutral position.
[0029] Toilet tanks 71 typically incorporate an upstanding inlet pipe and an upstanding overflow pipe 72 ( FIG. 1 ). The overflow pipe is formed on its top end 73 for when the water reaches a certain level, allow escape of the water thereby preventing overflow of the water from the tank. Overflow pipes of the type of the pipe 72 typically incorporate a network of water channels leading to the toilet bowl for replenishing bowl water after a flush.
[0030] With continued reference to FIG. 1 , such toilet tanks also typically incorporate an actuation knob or lever which might actuate a flush lever 75 to rotate a free end 77 between a lowered fill position and a raised flush position.
[0031] Referring to FIGS. 6 and 7 , the inlet pipe device 15 includes a lower pipe 131 typically connected through the bottom wall of the tank 71 and an upper pipe 141 telescoped downwardly therein. The pipe 141 is formed on its upper extremity 87 with a radially enlarged flange 81 constructed with an upwardly facing annular surface defining the control valve seat 19 .
[0032] The control valve device 13 includes a tubular housing, generally designated 91 , formed on its periphery with longitudinal guide ribs spaced equidistant annularly around the housing to provide a generally annular siphon break space between the housing and the control tube 51 . The lower portion of the housing is configured in part, by an interior annular flange and an exterior connector flange 21 ( FIG. 6 ). The housing is further formed with an annular top wall 93 ( FIG. 6 ). The top wall is formed centrally with a downwardly projecting cylindrical shell defining a central, stepped, vertical bore 95 which, in the upward direction, progressively reduces in diameter to terminate at its upper extremity in an upwardly opening O-ring gland for receipt of an O-ring 97 ( FIG. 7 ).
[0033] The diaphragm is then formed centrally with a upstanding, stepped tower 109 received complimentary in the stepped bore 95 and configured centrally with the pilot passage 26 . The tower is further configured at the upper extremity with an annular flange 111 receiving a reduced-in-diameter neck 113 of the stem.
[0034] The tower 109 is formed with a plurality of radially, outwardly opening bleed passages 115 for selectively bleeding fluid from the pilot passage 26 when the pilot valve is open.
[0035] In the preferred embodiment, the lever arm 42 is pivotally mounted on a pivot pin 121 carried from a yoke 123 standing up from the top side of the housing 93 . Referring to FIG. 6 , the right hand end of the lever arm includes a ball socket couple with a ball 125 formed at the upper extremity of the stem 37 .
[0036] Referring to FIGS. 4 , 6 and 7 , a pair of posts 132 and 133 stand up from the top of the housing 93 and project through spaced apart bores 136 in a top wall 140 of a cap 143 having an annular, downwardly projecting skirt 147 sitting on an annular flange 159 formed about the periphery of the valve housing.
[0037] As noted above, in one preferred embodiment, a donut shaped buoyant float 47 is telescoped over the control tube. The float is configured with an annular air chamber 154 and is formed on its interior diameter with one or more friction devices such a rib 161 ( FIG. 3 ) to form an interference fit with the exterior wall of the control tube 51 to releasably hold the float in position along the vertical length of such tube.
[0038] Referring to FIGS. 1 , 3 and 4 the valve housing is conveniently formed with a downwardly depending nipple 88 which is connected on its lower extremity with a fill tube 90 leading to the top end of the overflow pipe 72 for filling the bowl.
[0039] The diaphragm 20 is typically constructed of elastomeric material and includes a central body having a downwardly facing sealing surface 101 ( FIG. 7 ) to seat against the seat 19 . The diaphragm is concentrically formed about its periphery with an annular, flexible web 102 carrying the body from an anchor ring 104 trapped in an annular channel 106 formed between the top and bottom walls of the housing. The body incorporates a upwardly projecting, concentric rim 103 received in an annular clearance groove 105 formed in the underside of the top wall 93 .
[0040] It will be appreciated by those skilled in the art that the poppet 41 is enlarged in diameter and is preferably formed on its bottom side with upwardly and outwardly angled deflecting surfaces 60 . This serves to, when the valve is open or closing, deflect upwardly flowing water radially outwardly to then flow back radially inwardly under the seat 28 and upwardly into the annulus formed in the passage 26 .
[0041] Turning now back to FIGS. 5 and 8 , the fill pipe device 15 includes upper and lower pipes 141 and 131 respectively. The lower fill pipe 131 is configured in its upper extremity with a pair of interior annular ribs 137 formed to receive in overlapping radial relationship corresponding pairs of annular ribs 139 spaced along the exterior of the upper pipe 141 . The upper pipe is telescoped the desired distance downwardly into the lower pipe for selective registration of the ribs 137 in respective grooves formed between the ribs 139 on the upper tube 141 .
[0042] Referring to FIGS. 8 and 10 , the upper extremity of the lower pipe 131 is configured with four longitudinal, upwardly opening slots 142 spaced equidistant about the periphery to form four resilient, upstanding, cantilevered fingers 144 disposed in respective quadrants. As will be appreciated, each finger is formed at its upper extremity with a respective segment of the radially, inwardly projecting ribs 137 . Consequently, I provide a snap in feature facilitated by outwardly flared flange segments defining respective lips 138 at the upper extremities of the fingers having, when the fingers are in their relaxed position, a combined maximum outside diameter larger than the inside diameter at the top of the fitting flange 149 .
[0043] Formed in the lower extremity of the upper pipe 141 are a pair of O-ring grooves for receipt of O-rings 145 for sealing against the interior of the lower pipe 131 .
[0044] With continued reference to FIG. 8 , a spool shaped lock fitting, generally designated 149 , is received in telescopical relationship over the upper extremity of the lower pipe 131 and is formed with upper and lower radial flanges 151 and 155 .
[0045] As mentioned, in one preferred embodiment, the fitting 149 is formed with an upwardly narrowing tapered interior diameter sized to, be dropped down over the upper extremity of the lower pipe 131 during assembly to leave a concentric annulus between the pipe 131 and such inside diameter as shown in FIG. 8 for free rotation of the fitting on such pipe. In any event, as the fitting is brought into position the upper end will compress the upper ends of the fingers 144 in each quadrant radially inwardly to the point where the rib segments 137 will be diminished in their respective combined diameters to allow for relative longitudinal shifting to align with a selected groove formed between the ribs 139 to, upon release, register in the groove to lock the fill pipe device at the desired height. The fitting will thus be dropped down to the level where the lip segments will be disposed above the top of the fitting 149 to thus block the fitting from shifting upwardly, as for instance, under the force of the link 65 being drawn upwardly to the right during flush ( FIG. 5 ).
[0046] The flanges 151 and 155 ( FIGS. 8 and 10 ) are configured with a plurality of through, vertical bores 156 , respectively, spaced equidistant thereabout for receipt of the tube 90 . The flanges are further formed on their respective one sides with diametrical, outwardly opening clearance slots 157 for receipt of the catch device 55 and to act as a radial guide. The closed end of the slot in the upper flange acts as a stop 158 to limit counter clockwise rotation of the catch device.
[0047] With continued reference to FIG. 8 , conveniently, the fitting 149 is further formed below the flange 155 with a downwardly projecting annular skirt 167 . The mount device 58 is conveniently formed with an elastomeric ring 168 to be telescoped over the skirt 167 and is formed in its lower extremity with the radially, outwardly projecting, flexible hinge arm 59 . The hinge arm 59 is formed with a through vertical bore 174 for frictional receipt of one leg 173 of the catch device 55 . The other leg 175 of the catch device 55 is constructed of spring wire to project parallel to the leg 173 and cooperate in mounting the slider 187 . The leg 175 is formed at its lower extremity with a orthogonal tab 177 which, in the preferred embodiment, is turned radially inwardly toward the first leg 173 to terminate in an end spaced therefrom. In some embodiments, the tab 177 is turned radially outwardly so that the catch device can be mounted via that tab. As will be apparent to those skilled in the art, some embodiments do not include such a tab 177 . A U-shaped slider 187 , formed with bores and maintaining a keeper 61 , may be telescoped over the parallel legs 173 and 175 .
[0048] In the preferred embodiment, the leg 173 projects below the hinge arm 59 to define a lever arm formed with an eye 181 connected with the link 65 . As will be appreciated by those skilled in the art, the link 65 may take many different forms such as a chain, rigid link, coil spring or even an elastomeric strip.
[0049] The slider 187 is configured with a pair of horizontally spaced apart vertical bores into which spring wire legs 173 and 175 are friction fit for slidable adjustment of the slider 187 to the desired elevation on the catch device. As will be appreciated, such bores may merely be in the form of a single transverse, through slot, vertically receiving such legs at the opposite sides thereof.
[0050] In operation, it will be appreciated that the subject device can easily be installed in a conventional toilet tank 71 and the vertical adjustment made for the vertical profile of the tank and desired water level. Hence, when the water valve under the tank is opened, the water will flow upwardly through the inlet pipe device 15 through the upper tube 87 to pressurize under the diaphragm as shown in FIG. 7 thereby raising the diaphragm off its seat 19 allowing water to flow upwardly and radially outwardly under the diaphragm as indicated by the directional arrows 201 ( FIG. 7 ) to flow downwardly through the passages 166 into the tank 71 thereby commencing filling of such tank water will also flow downwardly through the nipple 88 through the tube 90 to the overflow pipe 72 to fill the toilet bowl. As the water level in the tank rises, the float 47 will be raised causing it to raise the control tube 51 thereby raising the free end 43 of the control lever arm 42 as shown in FIG. 6 to rotate such lever arm clockwise about its pivot pin 121 to drive the stem 37 downwardly. This will then lower the poppet 41 downwardly from its seat 28 to enable flow about such poppet and upwardly through the fluted grooves in the enlarged sections 33 and 35 and upwardly in the tower to flow radially inwardly through the bleed ports 115 to flow downwardly in the tower and radially outwardly above the top of the diaphragm 20 as indicated by the directional arrows 203 ( FIG. 6 ) to pressurize the top side of such diaphragm driving it downwardly to seat on the seat 19 and block further escape of incoming water from the upper tube 87 thereby serving to maintain the water in the tank 71 at the desired level.
[0051] Concurrently, as the control tube 51 is raised by elevation of the float 47 the bottom edge thereof will clear the elevation of the keeper 61 allowing the bias of the hinge arm 59 to rotate the catch device 55 clockwise about such hinge arm, as viewed in FIGS. 8 and 9 , to drive the keeper 61 radially outwardly under the wall of the tube 51 to block the downward path of such tube until such time as the toilet is flushed again.
[0052] As will be appreciated by those skilled in the art, water in the tank 71 will thus remain at the desired level prepared for the next flush. In the event, however, that water should accidentally leak from the tank, as by a loose or failing connection or crack in the tank, it will be appreciated that as the water level lowers in the tank without actuation of the flush control lever (not shown), the catch 55 will remain in the catch position shown in FIG. 8 , thus blocking the control tube 51 from lowering below the position shown. This then serves to prevent such control tube from lowering the free extremity 43 of the lever arm 42 ( FIG. 6 ) thus leaving the valve poppet off its seat and the top side of the diaphragm 20 pressurized to maintain the diaphragm on its seat 19 to block inflow of water from the upper inlet tube 87 .
[0053] Consequently, the total loss of water will be only that which is stored in the tank 71 and inflow of additional water from the upper inlet tube 87 will be blocked until such time as the homeowner or attendant note that the tank 71 has been evacuated without refill. This then alerts the homeowner of the leak thus allowing for repair work before the tank 71 is again filled with water.
[0054] With continued reference to FIG. 7 , when the poppet is closed it will thus be appreciated that water flowing upwardly from the upper inlet tube 87 it will strike the facing conical surface of the poppet 41 to be diverted radially, outwardly, and downwardly as indicated by directional arrows 201 to the outlets 166 to be defined by annular deflectors 85 .
[0055] Referring to FIG. 6 , when the poppet is open the incoming water will be directed to flow outwardly around the conical surface of the poppet to flow upwardly in the passage 26 , through the annuli formed with the respective ports 27 and 29 , via the grooves in the flutes of the enlarged sections 33 and 35 ( FIG. 6 ). Flow will continue on upwardly in the tower to flow outwardly in the bleed ports 115 ( FIG. 7 ) to maintain a positive pressure differential acting down on the top of the diaphragm 20 . The control valve will thus remain closed until such time as the float and control tube are lowered as by a toilet flush.
[0056] It will be appreciated that as the float carries the control tube 51 up, the lower edge of such tube will be raised above the level of the keeper 61 to free the catch to be rotated clockwise under the influence of the elastomeric hinge arm 59 to the position shown in FIG. 8 disposed under the bottom edge of such tube.
[0057] Then, when the flush handle is operated to flush the toilet, the outlet valve 53 ( FIG. 1 ) will be opened and the link 65 drawn to the right as viewed in FIG. 9 to rotate the catch device 55 counter clockwise about the point defined by the hinge arm 59 to drive the upper end of such catch device 55 to the left to strike the stop 158 as the keeper 61 is likewise shifted to the left from under the edge of the tube 51 freeing such tube to lower. This then serves to lower the free end 43 of the lever 42 ( FIG. 7 ) to raise the poppet 41 to discontinue bleed of fluid up the passage 26 and pressurize the underside of the diaphragm to raise such diaphragm off its seat. This then allows for pressurized water to flow out of the upper inlet tube 87 to flow radially outwardly and down through the ports 166 as depicted by the directional arrows ( FIG. 7 ) to again fill the tank.
[0058] As will be appreciated by those of skill, for different types of water tanks 71 , such as the ever-popular low profile tanks, the vertical adjustment of the inlet pipe device 15 will be made to establish the desired level of water in the tank. Thus, for a low profile tank, the upper inlet pipe 141 may easily be telescoped downwardly into the lower pipe 131 as the ribs 139 flexibly pass the ribs 137 until the desired height of the inlet device is established thereby positioning the float 47 at the desired level for causing the control tube 51 to actuate the control lever 42 at the desired water level.
[0059] In that regard, the reader will understand that when the inlet pipe device is telescoped down, it is possible to slide the slider 187 down a corresponding amount on the catch device 55 to thus coordinate actuation of and blocking in accordance with the desired height of the water in the tank 71 .
[0060] The embodiment of the present invention shown in FIG. 11 is similar to that shown in FIG. 7 except that the pilot stem 37 is configured at its lower extremity with an enlarged poppet in the form of a spherical poppet 191 configured to seat upwardly on the downwardly facing pilot seat 28 .
[0061] From the foregoing it will be appreciated that the valve control device of the present invention is made up of a minimal number of parts making it economical to manufacture and assemble to provide an economical and convenient and effective means for controlling flow of water from an inlet pipe and will provide for a long trouble free life with minimal or no clogging due to residue, scum or the like as might be carried by the water.
[0062] Although the present invention has been described in detail with regard to the preferred embodiments and drawings thereof, it should be apparent to those of ordinary skill in the art that various adaptations and modifications of the present invention may be accomplished without departing from the spirit and the scope of the invention. Accordingly, it is to be understood that the detailed description and the accompanying drawings as set forth hereinabove are not intended to limit the breadth of the present invention. | In one aspect, the device includes a control apparatus including a pilot valve projecting through a passage in a control diaphragm to be formed with an enlarged poppet to seat the underside of the diaphragm and formed with a poppet head shaped to direct incoming flow away from the pilot passage to minimize entry of residue.
In another aspect, the present invention includes an elongated catch device pivotally mounted intermediately to an inlet pipe device and carrying at its upper extremity a keeper selectively disposed in the path of a float device to, unless a toilet has been flushed, block lowering of the float device and consequent opening of the control valve. | 4 |
BACKGROUND OF THE INVENTION
Vented, gas-fired appliances relying on a natural draft for the removal of products of combustion are equipped with a draft hood which isolates the combustion chamber from excessive updraft or backdraft in the vent. The conduit between the draft hood relief opening and the outside is permanently open and therefore causes heat loss, especially during cold and windy weather.
Automatic vent dampers have been designed to reduce this loss. Examples are the thermally controlled vent dampers described in U.S. Pat. Nos. 3,228,605 and 3,510,059. These automatic, thermally controlled vent dampers are installed between the draft hood and the vent connector. They are open during the operating phase of the appliance and are closed during standby and shutdown periods.
OBJECTS AND SUMMARY OF THE INVENTION
Under certain normal operating conditions the buoyancy force for moving the vent gases from the heating appliance to the outside is small. Draft hoods, as well as vent dampers even in their fully open position, pose a certain resistance to the flow of vent gases. This resistance to flow in the vent system sometimes results in the incomplete removal of products of combustion and causes spillage of vent gases at the draft hood relief opening. It is therefore desirable to reduce to a practical minimum the resistance to flow of vent gases in natural draft appliance-vent systems.
One object of the invention is to reduce the resistance to flow of vent systems containing draft hoods and automatic, thermally controlled vent dampers.
Another object of the invention is the improvement of the performance of the above-described draft hood-vent damper combination.
A further object of the invention is an arrangement that prevents possible permanent deformation of bimetal damper elements caused by temperature-induced bending forces if the damper elements are mechanically prevented from moving beyond the fully open position at temperatures above that corresponding to fully open position.
Another object is an arrangement that does not increase flow resistance due to the damper elements bending beyond the fully open position at temperatures above that corresponding to such position.
The invention in summary includes bimetallic damper elements which are shaped and arranged in the draft hood so that the draft hood outlet is closed during the non-operating phases of the heating apparatus and so that the damper elements either move out of the flow of the vent gases altogether or assume, in conjunction with the adjacent stationary parts of the draft hood, a shape that minimizes resistances to flow of vent gases during full main burner firing. The draft control arrangement includes: (a) a damper in which the sensing element and the throttling element is the same part, i.e., no transmission of movements, forces or signals from one component to another is required for its function; (b) damper elements arranged in such a manner among themselves and in relationship to the surrounding stationary components that a small flexing movement of the bimetallic damper element, during its opening movement, opens a relatively large area for the passage of vent gases; (c) installation of the damper elements in the flow path in a manner that minimizes resistance to flow of the vent gases in natural draft vent systems containing draft hood and vent damper; (d) reducing the tendency for spillage at the relief opening of the draft hood during startup and in weak-draft situations by elongating the draft hood and thereby increasing its capacity to absorb fluctuations in flow; (e) reducing the tendency for said spillage further by having the bimetallic sensing elements installed in the draft hood, rather than above the draft hood as a separate unit, thereby having them positioned close to the source of the hot products of combustion, causing the damper elements to open faster; (f) an arrangement that avoids possible permanent deformation of bimetal damper elements caused by temperature-induced bending forces if the damper elements are mechanically prevented from moving beyond the fully open position at temperatures above that corresponding to fully open position of the damper; (g) providing modulating draft control by the continuous and nearly instantaneous response of the bimetallic damper elements to temperature differences in the vent gases. When a strong draft aspirates an excessive amount of dilution air through the draft hood relief opening the temperature of the mixture of flue gases and dilution air decreases and the bimetal damper elements close partially, until a new equilibrium at a lower rate of dilution air is established. In addition to their primary job of saving energy by closing the vent during the standby phases of the heating apparatus the embodiments of this invention reduce heat loss also during the operating phases by the described modulating action.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of a typical prior art combination of heating apparatus, draft hood, vent damper and vent connector.
FIG. 2 is a perspective view of a prior art thermally controlled vent damper.
FIG. 3 is a longitudinal section view of one embodiment of the present invention.
FIG. 4 is a sectional view taken along the line 4--4 of FIG. 3.
FIG. 5 is a longitudinal section view of another embodiment of the invention.
FIG. 6 is a section view taken along the line 6--6 of FIG. 5.
FIG. 7 is a longitudinal section view of another embodiment of the invention.
FIG. 8 is a section view taken along the line 8--8 of FIG. 7.
FIG. 9 is a perspective view, partially broken-away, of another embodiment of the invention.
FIG. 10 is a longitudinal section view taken along the line 10--10 of FIG. 9.
BRIEF DESCRIPTION OF THE PRIOR ART
FIG. 1 shows a typical prior art assembly comprising heating apparatus 10, draft hood 12, vent damper 14 and vent connector 16. During normal operation the vent gases flow upward from the heating apparatus through draft hood inlet 18, hood 12, outlet 22, vent damper 14 and into vent connector 16. If excessive draft prevails considerable amounts of dilution air are drawn into the vent through the annular draft hood relief opening 24. If a backdraft reverses the flow in the vent the gases from the vent, entering through draft hood outlet 22, and the products of combustion coming from the heating apparatus through draft hood inlet 18 flow out of the draft hood at the relief opening 24, as shown by arrow 26. In the case of excessive updraft or downdraft the draft hood isolates the combustion process in the heating apparatus from disturbing flows. Draft hoods are therefore required components of natural draft gas-fired heating systems.
FIG. 2 shows a prior art thermally controlled vent damper. The damper comprises tubular housing 28 which is subdivided by partitions 30 into sections, illustrated as four quadrants. Each quadrant is covered by a thin slotted bimetal flap 32. The flaps are attached at their upper edges to the partitions and curve upward into abutting relationship with the partitions when the damper is closed. The temperature of hot flue gases causes the flaps to change shape and uncurl to open the throttle area. When temperatures above that corresponding to fully open position are encountered the flaps could move beyond that position creating increased flow resistance.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 3 and 4 illustrate a first embodiment of the invention comprising a round, tubular draft hood inlet 34 which connects with the heating apparatus, a draft hood 36, annular relief opening 38 and round, tubular outlet 40 which connects with a vent. Double-cone baffle 42 is concentrically mounted within the draft hood by suitable brackets, not shown, which can be attached to the hood inlet. A plurality of bimetallic damper elements 44 are mounted at their upper ends about the lower rim of outlet 40. The damper elements are petal-shaped and can be formed of juxtaposed strips, or of one or more plates having slots which form a plurality of distal ends. The damper elements assume at ambient temperature an approximately spherical shape and cooperate with the baffle to form a closure across the passage through the draft hood. When the heating apparatus is turned on the hot flue gases rise from the combustion chamber through inlet 34 into the draft hood. The gases heat the bimetallic damper elements which are caused to flex away from baffle 42 and thereby open the passage for flue gases and dilution air through outlet 40 into the vent.
In addition to the annular opening which is established between baffle 42 and the tips of the bimetal elements 44 by the initial opening movement, passages open laterally between the tips of the individual elements resulting from their spreading movement. The total opening available for passage of vent gases shortly after the opening movement starts is therefore disproportionately high and helps reduce the tendency for spillage at startup. When fully open the damper elements assume a straight shape at position 44' in abutting surface-to-surface contact with the hood. At the fully open position the resistance to flow due to the damper elements becomes negligible due to the streamlining as the elements conform to the inner contour of the draft hood. The hood could also be slightly widened at its circumference between points 46 and 48, thereby creating a shallow depression inside the hood. The bimetallic elements would move into such a depression in their fully opened position, thereby being flush with the inner surfaces of the hood and the outlet.
It is generally desirable that a thermally controlled vent damper starts opening at a certain temperature, e.g., 160° F., and that it reaches its fully open position at the minimum temperature prevailing at the damper during full flame operation. However temperatures much higher than the said minimum operating temperature may occur at the damper during the operation of the heating apparatus during which no further movement of the bimetal blades is desirable. Yet the bimetal elements tend to react to higher temperature by further flexing beyond the fully open position. When a movement beyond the fully open position is prevented by a mechanical stop the bending force may be strong enough to cause a permanent deformation of the bimetal elements. In all embodiments shown in this specification a movement beyond the fully open position is prevented by the walls of the draft hood or damper housing respectively. However in the embodiments shown in FIGS. 3, 4, 9 and 10 a buildup of bending forces in the bimetal blades at higher then "fully open" temperatures is effectively reduced. The close proximity or contact of the bimetal blades with the wall of the draft hood or damper housing prevents circulation of hot vent gases between the bimetal blades and wall, while surface-to-surface contact allows heat to transfer from the bimetal blades to the wall and from the wall to the ambient air.
FIGS. 5 and 6 show another embodiment comprising a round, tubular inlet 50, a pyramid-shaped hood 52, a relief opening 54, and an outlet 56 which forms a transition from square at 58 to round at 60 where it connects with a vent. A double-pyramid baffle 62 is concentrically mounted with the draft hood by suitable brackets, not shown, which can be attached to the hood inlet. The bimetallic damper elements in this embodiment comprise four rectangular, slotted plates 64-70 fastened to the respective sides which form the square, lower part of outlet 56. The slots determine the direction in which the bimetal elements curve under the influence of temperature changes. At room temperature the four plates cooperate with the baffle to form a closure across the passage between the draft hood inlet and outlet.
When the heating apparatus is turned on the hot flue gases rise through inlet 50 into the draft hood. The gases heat the bimetal damper elements 64-70 and cause them to flex away from baffle 62 and thereby open the passage for the flue gases through outlet 56 into the vent. In the fully open position the damper plates, as shown by dashed line 64', are smoothly curved against the draft hood wall so that the flow passage is streamlined.
FIGS. 7 and 8 illustrate a further embodiment which includes a round, tubular inlet 72, a draft hood 74 with essentially rectangular cross section, relief opening 76 and a laterally offset outlet 78 which forms a transition from square at 80 to round at 82 where it connects with a vent.
A bimetallic slotted damper blade or plate 84 is secured by fasteners 86 to one side of the square portion of outlet 78. At room temperature both opposite sides and the freely moving lower end of the damper plate contact frame 88 so as to form a closure across the passage through outlet 78.
When the heating apparatus is turned on the hot flue gases rise through inlet 72 into the draft hood. The gases heat the bimetal damper plate 84 and cause it to flex away from frame 88. When fully open, the damper plate is at position 84' with the curvature indicated by the dashed line. In this position the damper plate provides a streamlined shape presenting a minimum resistance to the flow of gases.
FIGS. 9 and 10 illustrate a vent damper 89 incorporating a further embodiment of the invention. Under certain circumstances, e.g., if the draft hood is an integral part of an existing heating apparatus which cannot or should not be modified, the vent damper 89 can be placed in the conventional manner between the draft hood and the vent connector. Vent damper 89 comprises a round inlet 90, a housing 92 shown here as having essentially square cross-section with two indentations or recesses 94, 95 in opposite walls, and a round outlet 98. Two essentially rectangular, slotted, curved bimetal blades 100 and 102 are fastened at their upper ends to the housing. The bimetal blades are narrower that the inside width of the housing, thereby providing ample lateral clearance for their unrestricted movement. The inner sides of the recesses are curved to conform and overlap with the side margins of the respective blades when in their closed position.
At ambient temperature the bimetal blades are curved inward and their lower ends touch each other. Lateral edges of the blades also touch the curved inner sides of the recesses 94, 95 formed in the housing and thereby essentially close the flow passage through the damper.
When hot products of combustion rise from the heating apparatus the bimetal blades start to uncurl and at the full, steady state operating temperature assume a straight shape parallel to, and essentially touching, the walls of the housing to which they are fastened as indicated by dashed line 100'. Shallow depressions 104, 106 are formed in opposite sides of housing 92 by the increase in lateral dimension of the housing walls in comparison to the diameter of the round inlet and outlet. There is a gradual transition from round to square at the inlet, and from square to round at the outlet. The damper blades when straight are seated flat against the walls of the housing inside the depressions where the blades are out of the gas flow passage.
The embodiment of damper 89 thereby achieves the following new combination of functions: (a) the sensing and throttling element is the same part; (b) the housing, including the shallow depressions, the bimetal blades are shaped and arranged in such a way that resistance to flow is minimized; (c) modulating draft control is provided and (d) buildup of excessive bending forces in the bimetal damper elements is high temperatures is avoided, as explained in connection with the embodiment of FIGS 3-4.
An effect mentioned previously in the description of FIGS. 3 and 4, namely the formation of a disproportionately large opening during the initial phase of the opening movement by passages opening laterally between the strips of bimetal resulting from their spreading movement, can also be achieved in a vent damper. For that purpose a number of individual, curved bimetal strips would be shaped and fastened inside the circumference of a round damper housing in such a manner that their tips, at ambient temperature, touch a small double-cone or similar streamlined, round stop installed in the center of the damper housing.
While the foregoing embodiments are at present considered preferred it is understood that numerous variations and modifications may be made therein by those skilled in the art and it is intended to cover in the appended claims all such variations and modifications as fall within the true spirit and scope of the invention. | A draft control arrangement having bimetallic damper elements mounted in a draft hood and adapted to change shape in response to temperature change to open and close the flow passage for vent gases from a combustion apparatus. The damper elements are positioned in the hood relatively close to the source of hot flue gases to provide faster opening and less tendency for vent gas spillage. When open the damper elements cooperate with stationary walls of the draft hood so that the resulting streamlined passage presents minimum flow resistance. In certain embodiments the damper elements are arranged to undergo a spreading action during opening movement to achieve a disproportionately large passage for the vent gases during the initial phase of opening. In another embodiment a damper unit is mounted separate from the draft hood and provides the same operating results as the other embodiments. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a process for producing an optically active 2-alkoxycyclohexanol derivative, and more particularly, to a process for producing an (S,S)-2-alkoxycyclohexanol.
2. Prior Art
It is known that optically active 2-alkoxycyclohexanol derivatives such as (S,S)-2-alkoxycyclohexanol are important synthetic intermediates in the productions of medicines and agricultural chemicals.
As a process for producing an optically active 2-alkoxycyclohexanol derivative, for example, the following methods have been investigated: 1 the process in which a carboxylic ester of a (±)-trans-2-methoxycyclohexanol is hydrolyzed selectively in R-configuration in the presence of hydrolase to give a carboxylic ester of an (S,S)-2-alkoxycyclohexanol and an (R,R)-2-methoxycyclohexanol (Tetrahedron, 50 (35), 10521-30 (1994), Synthesis, 12, 1137-40 (1990), and J. Chem. Soc. Chem. Commun., 3, 148-50 (1989)), 2 the process in which a carboxylic ester of a (±)-trans-2-methoxycyclohexanol is hydrolyzed selectively in S-configuration in the presence of hydrolase to give an (S,S)-2-methoxycyclohexanol and a carboxylic ester of an (R,R)-2-alkoxyhexanol (WO94/20634), and 3 the process for obtaining an (R,R)-2-methoxycyclohexanol by asymmetric hydroboration of 1-methoxycyclohexene (J. Org. Chem., 53 (9), 1903-7 (1988)).
Though the process 1 is highly stereoselective, the configuration of an optically active 2-alkoxycyclohexanol obtained is (R,R)-configuration and a further hydrolysis of the carboxylic ester of (S,S)-2-alkoxycyclohexanol produced must be carried out in order to obtain (S,S)-2-alkoxycyclohexanol.
Though (S,S)-2-alkoxycyclohexanol can be obtained through the process 2, this method is not sufficiently stereoselective and there are some problems in productive efficiency and economical efficiency.
A stereoselectivity of process 3 is low, and further, there are such problems as reagents used in this process are expensive and etc.
SUMMARY OF THE INVENTION
Taking an account of the above-mentioned circumstances, the object of the present invention is to provide a process for efficiently producing an (S,S)-2-alkoxycyclohexanol in a single step from a (±)-trans-2-alkoxycyclohexanol which is inexpensive and easily available.
The gist of this invention is a process for producing an (S,S)-2-alkoxycyclohexanol which comprises treating a (±)-trans-2-alkoxycyclohexanol which is expressed by the general formula (1); ##STR1## (wherein R 1 represents a lower alkyl, an alkenyl, a cycloalkyl, a substituted or unsubstituted aryl, or a substituted or unsubstituted aralkyl group) with a hydrolase originating in a microorganism which is capable of esterifying the R-isomer stereospecifically in the presence of an acyl donor under a condition that no hydrolysis occurs substantially to thereby give an (S,S)-2-alkoxycyclohexanol which is expressed by the general formula (2); ##STR2## (wherein R 1 is the same as previously defined), and a carboxylic ester of an (R,R)-2-alkoxycyclohexanol which is expressed by the general formula (3) ##STR3## (wherein R 1 is the same as previously defined and R 2 represents a hydrogen, straight-chain or branched alkyl having 1 to 17 carbon atoms, or straight-chain or branched alkenyl group having 1 to 17 carbon atoms), and then taking up said (S,S)-2-alkoxycyclohexanol.
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention is explained in more details.
A (±)-trans-2-alkoxycyclohexanol which is used in this invention is a compound given in the above general formula (1). R 1 in the above formula is not specially limited to but includes a lower alkyl group such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, t-butyl, sec-butyl and the like; an alkenyl group such as vinyl, allyl, isobutenyl and the like; a cycloalkyl group such as cyclohexyl, cyclopentyl and the like; a substituted or unsubstituted aryl group such as p-nitrophenyl, a phenyl and the like; and a substituted or unsubstituted aralkyl group such as p-nitrobenzyl, benzyl and the like. Among these, a methyl group is preferable.
The above (±)-trans-2-alkoxycyclohexanol can be synthesized easily from cyclohexene oxide which can be obtained commercially, and a corresponding alcohol, for example, by the method which proposed in J. Am. Chem. Soc., 65, 2196 (1943).
Preferable examples of an acyl donor which is used in the present invention can be either compounds expressed by a general formula (4);
(R.sup.2 CO).sub.2 O (4)
(wherein R 2 represents a hydrogen atom, straight-chain or branched alkyl having 1 to 17 carbon atoms, or straight-chain or branched alkenyl group having 1 to 17 carbon atoms), compounds expressed by a general formula (5);
R.sup.3 OOCR.sup.2 (5)
(wherein R 2 is the same as previously defined, R 3 is a straight-chain or branched alkyl having 1 to 17 carbon atoms, straight-chain or branched alkenyl group having 2 to 17 carbon atoms, 2,2,2-trihalogenoethyl group, or a substituted or unsubstituted phenyl), or compounds expressed by a general formula (6); ##STR4## (wherein R 2 is the same as previously defined).
R 2 mentioned above is not particularly limited to but includes a hydrogen; an alkyl group such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, t-butyl, sec-butyl, pentyl, heptyl and the like; and an alkenyl group such as vinyl, allyl, isopropenyl, isobutenyl and the like. Among these, a propyl group is preferable.
R 3 mentioned above is not particularly limited to but includes an alkyl group such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, t-butyl, sec-butyl and the like; an alkenyl group such as vinyl, isopropenyl and the like; a trihalogenoethyl group such as 2,2,2-trichloroethyl, 2,2,2-tribromoethyl, 2,2,2-trifluoroethyl and the like; and a substituted or unsubstituted aryl group such as p-nitrophenyl, phenyl and the like. Among these, a vinyl group is preferable.
The above acyl donor preferably includes butyric anhydride, vinyl butyrate, tributyrin and so on.
The hydrolase originating in a microorganism which is capable of esterifying the R-isomer stereospecifically, which is used in the present invention, is not particularly limited to but includes lipase, esterase, acylase, and so on.
Preferable are a lipase derived from microorganisms which belong to Alkaligenes, a lipase derived from microorganisms which belong to Candida, a lipase derived from microorganisms which belong to Pseudomonas, a lipase derived from microorganisms which belong to Mucor, and the like.
The above lipase derived from microorganisms which belong to Alkaligenes includes "Lipase PL" (a registered trademark of product of MEITO SANGYO Co.) and so on. The above lipase derived from microorganisms which belong to Candida includes "Novozym 435" (a registered trademark of product of Novo-Nordisk A/S), "Lipase OF" (a registered trademark of product of MEITO SANGYO Co.), "Lipase MY" (a registered trademark of product of MEITO SANGYO Co.) and so on. The above lipase derived from microorganisms which belong to Pseudomonas includes "Lipase PS AMANO" (a registered trademark of product of AMANO PHARMACEUTICAL Co.) and so on. The above lipase derived from microorganisms which belong to Mucor includes "Lipozyme IM" (a registered trademark of product of Novo-Nordisk A/S).
The above hydrolase originating in microorganisms which is capable of esterifying the R-isomer stereospecifically can also be used in the form of microorganisms cells containing said hydrolase. The example of the above microorganism cells includes a yeast which belongs to Alkaligenes, Candida, Pseudomonas, Mucor and etc. and cells such as filamentous fungi, bacteria and so on.
In the present invention, the above microorganism cells can be used in any treatment cells forms such as freeze-dried cells, cells treated by acetone, toluene and so on, cell homogenate, an extract from cells and so on.
The above microorganism cells and treatment cells can be used as they are, or after immobilized.
The producing process for an optically active 2-alkoxycyclohexanol derivative in the present invention can be carried out, for example, as follows.
A (±)-trans-2-alkoxycyclohexanol as a stating material is dissolved in a solvent in the concentration of 0.1 to 70 w/v %, preferably 1 to 50 w/v %, and there are added 0.5 to 10 times equivalent, preferably 0.5 to 2 times equivalent of above-mentioned acyl donor to the (±)-trans-2-alkoxycyclohexanol and 0.001 to 10 parts by weight, preferably 0.01 to 1 parts by weight of the above-mentioned hydrolase which is capable of esterifying the R-isomer stereospecifically to the (±)-trans-2-alkoxycyclohexanol, and the solution was mixed under stirring to carry out asymmetric esterification.
After completion of the asymmetric esterification, the hydrolase described above is recovered by filtration or centrifugation as insoluble material. Purified (S,S)-2-alkoxycyclohexanol and purified carboxylic ester of (R,R)-2-alkoxycyclohexanol are obtained by concentration and distillation of the filtrate.
In the present invention, the asymmetric esterification described above is carried out under the condition where no hydrolysis reaction occurs substantially. For example, because hydrolysis which is reverse reaction of an above esterification proceeds in the case of the presence of water in the system, it is preferable that above-described asymmetric esterification is performed in the solvent that contains no water or a very little amount of water.
The solvent used in the present invention is not particularly limited to but includes solvents which do not inactivate the hydrolase, for example, a hydrocarbon type solvents such as toluene, hexane and so on; ether type solvents such as diisopropyl ether, tetrahydrofuran, methyl tert-butyl ether and so on; ketone type solvents such as acetone and methyl ethyl ketone; and ester type solvents such as ethyl butyrate.
In the present invention, the above asymmetric esterification can be carried out without the above solvent except the above substrate and the reaction reagent.
The reaction temperature in the process of the above asymmetric esterification is preferably 0° C. to 80° C., and more preferably 10° C. to 50° C.
The reaction time in the process of the above asymmetric esterification is preferably 1 to 240 hours, and more preferably 1 to 72 hours.
BEST MODE FOR CARRYING OUT THE INVENTION
The invention will be described in more detail with reference to the following example, which are not intended to restrict the scope of the invention.
EXAMPLES 1 to 6
The mixture of 260 mg of (±)-trans-2-methoxycyclohexanol, 1.27 ml of vinyl butyrate and 130 mg of various kinds of lipase was poured in 15 ml-screw tubes and a reaction was carried out for 24 hours at room temperature during agitating. The resulted reaction mixture was filtered. The conversion rate was determined by GC analysis of the filtrate. From the residual trans-2-methoxycyclohexanol, a derivative thereof was given (DNB derivative), and the optical purity was measured by HPLC analysis. Every configuration of the trans-2-methoxycyclohexanol was (S,S)-configuration. The conversion rate and the optical purity are shown in table 1.
EXAMPLES 7 to 30
After 130 mg of (±)-trans-2-methoxycyclohexanol and 127 μl of vinyl butyrate were poured in 15 ml-screw tubes, dissolved in 1 ml of various kind of solvent, and there was added 65 mg of various kind of lipase. The mixture was reacted at 30° C. for 24 hours during stirring. The solution was filtered and the conversion rate was determined by GC analysis of the filtrate. From the residual trans-2-methoxycyclohexanol, a derivative thereof was given (DNB derivative), and the optical purity was measured by HPLC analysis. Every configuration of the trans-2-methoxycyclohexanol was (S,S)-configuration. The conversion rate and the optical purity are shown in table 2.
EXAMPLES 31 to 54
After 130 mg of (±)-trans-2-methoxycyclohexanol and 127 μl of various kind of acyl donor were poured in 15 ml-screw tubes, dissolved in 1 ml of toluene, and there was added 65 mg of various kind of lipase. The mixture was reacted at 30° C. for 24 to 96 hours during stirring. The solution was filtered and the conversion rate was determined by GC analysis of the filtrate. From the residual trans-2-methoxycyclohexanol, a derivative thereof was given (DNB derivative), and the optical purity was measured by HPLC.
Every configuration of the trans-2-methoxycyclohexanol was (S,S)-configuration. The conversion rate and the optical purity are shown in table 3.
TABLE 1__________________________________________________________________________ Conversion OpticalExampleEnzyme for use rate (%) purity (% ee)__________________________________________________________________________1 Lipase PL (Alkaligenes origin, MEITO SANGYO Co.) 54.9 21.42 Novozym 435 (Candida origin, Novo-Nordisk A/S) 51.5 1003 Lipase OF (Candida origin, MEITO SANGYO Co.) 48.7 794 Lipase MY (Candida origin, MEITO SANGYO Co.) 22.1 21.45 Lipase PS AMANO (Pseudomonas origin, AMANO PHARMACEUTICALS 47.7 94.86 Lipozyme IM (Mucor origin, Novo-Nordisk A/S) 51.2 100__________________________________________________________________________
TABLE 2__________________________________________________________________________ Conversion OpticalExampleEnzyme for use Reaction solvent rate (%) purity (%__________________________________________________________________________ ee) 7 Novozym 435 (Candida origin, Novo-Nordisk A/S) Hexane 57.8 96.6 8 Novozym 435 (Candida origin, Novo-Nordisk A/S) Toluene 52.6 98.7 9 Novozym 435 (Candida origin, Novo-Nordisk A/S) Diisopropyl ether 54.6 95.710 Novozym 435 (Candida origin, Novo-Nordisk A/S) Tetrahydrofuran 51.4 97.811 Novozym 435 (Candida origin, Novo-Nordisk A/s) Methyl tert-butyl 53.8r 93.312 Novozym 435 (Candida origin, Novo-Nordisk A/S) Acetone 41.8 77.713 Novozym 435 (Candida origin, Novo-Nordisk A/S) Methyl ethyl ketone 53.3 98.714 Novozym 435 (Candida origin, Novo-Nordisk A/S) Ethyl butyrate 53.5 98.915 Lipase PS AMANO (Pseudomonas origin, AMANO PHARMACEUTICALS Hexane 50.3 95.916 Lipase PS AMANO (Pseudomonas origin, AMANO PHARMACEUTICALS Toluene 51.8 10017 Lipase PS AMANO (Pseudomonas origin, AMANO PHARMACEUTICALS Diisopropyl ether 52.4 10018 Lipase PS AMANO (Pseudomonas origin, AMANO PHARMACEUTICALS Tetrahydrofuran 51.5 98.219 Lipase PS AMANO (Pseudomonas origin, AMANG PHARMACEUTICALS Methyl tert-butyl 52.6r 10020 Lipase PS AMANO (Pseudomonas origin, AMANO PHARMACEUTICALS Acetone 50.7 10021 Lipase PS AMANO (Pseudomonas origin, AMANO PHARMACEUTICALS Methyl ethyl ketone 44 77.522 Lipase PS AMkNO (Pseudomonas origin, AMAND PHARMACEUTICALS Ethyl butyrate 50.3 95.923 Lipozyme IM (Mucor origin, Novo-Nordisk A/S) Hexane 49.3 87.824 Lipozyme IM (Mucor origin, Novo-Nordisk A/S) Toluene 51.9 10025 Lipozyme IM (Mucor origin, Novo-Nordisk A/S) Diisopropyl ether 51.5 95.826 Lipozyme IM (Mucor origin, Novo-Nordisk A/S) Tetrahydrofuran 42.4 76.227 Lipozyme IM (Mucor origin, Novo-Nordisk A/S) Methyl tert-butyl 52.1r 95.328 Lipozyme IM (Mucor origin, Novo-Nordisk A/S) Acetone 26.6 49.329 Lipozyme IM (Mucor origin, Novo-Nordisk A/S) Methyl ethyl ketone 44.7 82.330 Lipozyme IM (Mucor origin, Novo-Nordisk A/S) Ethyl butyrate 46.9 84.8__________________________________________________________________________
TABLE 3__________________________________________________________________________ Conversion OpticalExample Enzyme for use Acyl donor rate (%) purity (%__________________________________________________________________________ ee)31 Novozym 435 (Candida origin, Novo-Nordisk A/S) Acetic anhydride 31.9 54.832 Novozym 435 (Candida origin, Novo-Nordisk A/S) Vinyl acetate 48.4 86.333 Novozym 435 (Candida origin, Novo-Nordisk A/S) Isopropenyl acetate 52.6 95.634 Novozym 435 (Candida origin, Novo-Nordisk A/S) Butyric anhydride 49.1 96.235 Novozym 435 (Candida origin, Novo-Nordisk A/S) Vinyl butyrate 57.1 95.936 Novozym 435 (Candida origin, Novo-Nordisk A/S) Tributyrin 38.3 57.937 Novozym 435 (Candida origin, Novo-Nordisk A/S) Ethyl butyrate 30.7 44.638 Novozym 435 (Candida origin1 Novo-Nordisk A/S) Vinyl capronate 51.5 95.939 Lipase PS AMANO (Pseudomonas origin, AMANO PHARMACEUTICALS Acetic anhydride 46.1 81.840 Lipase PS AMANO (Pseudomonas origin, AMANO PHARMACEUTICALS Vinyl acetate 40.7 73.841 Lipase PS AMANO (Pseudomonas origin, AMANO PHARMACEUTICALS Isopropenyl acetate 15. 8 --42 Lipase PS AMANO (Pseudomonas origin, AMANG PHARMACEUTICALS Eutyric anhydride 15.2 --43 Lipase PS AMANO (Pseudomonas origin, AMANO PHRAMACEUTICALS Vinyl butyrate 51.9 95.844 Lipase PS AMANO (Pseudomonas origin, AMANO PHARMACEUTICALS Tributyrin 24.2 --45 Lipase PS AMANO (Pseudomonas origin, AMANO PHARMACEUTICALS Ethyl butyrate 15.5 --46 Lipase PS AMANO (Pseudomonas origin, AMANO PHARMACEUTICALS Vinyl capronate 54.8 94.947 Lipozyme IM (Mucor origin, Novo-Nordisk A/S) Acetic anhydride 17.2 --48 Lipozyme IM (Mucor origin, Novo-Nordisk A/S) Vinyl acetate 46.3 87.349 Lipozyme IM (Mucor origin, Ncvo-Nordisk A/S) Isopropenyl acetate 35.8 64.450 Lipozyme IM (Mucor origin, Novo-Nordisk A/S) Butyric anhydride 40.1 64.151 Lipozyme IM (Mucor origin, Novo-Nordisk A/S) Vinyl butyrate 52.3 9652 Lipozyme IM (Mucor origin, Novo-Nordisk A/S) Tributyrin 34.8 53.853 Lipozyme IM (Mucor origin, Novo-Nordisk A/S) Ethyl butyrate 23.2 --54 Lipozyme IM (Mucor origin, NovO-Nordisk A/S) Vinyl capronate 54.8 95.7__________________________________________________________________________
Industrial Applicability
Because of the above-mentioned constitute according to the present invention, we can produce an (S,S)-2-alkoxycyclohexanol efficiently and easily, which are useful for intermediates on production of medicines. | A process for efficiently producing (S,S)-2-alkoxycyclohexanols in a single step by using (±)-trans-2-alkoxycyclohexanols which are inexpensive and can be easily obtained. The process comprises treating a (±)-trans-2-alkoxycyclohexanol with a hydrolase originating in a microorganism and being capable of esterifying stereospecifically the R-isomer in the presence of an acyl donor under such conditions that no hydrolysis occurs substantially to thereby give (S,S)-2-alkoxycyclohexanols and (R,R)-2-alkoxycyclohexanol carboxylate and then taking up the (S,S)-2-alkoxycyclohexanols. | 8 |
TECHNICAL FIELD
[0001] This invention relates to benzoxazine compounds and varnishes which may be cured to form polymeric networks which are difficultly inflammable and resistant to high temperatures, as well as to the use of such polymeric resins. More particularly, this invention relates to 3,3′-bis(3,4-dihydro-3-phenyl-2H-1,3-benzoxazin-6-yl)-1(3H)-isobenzofuranone and analogues based on phenolphthalein, formaldehyde and a primary amine.
BACKGROUND OF THE INVENTION
[0002] Benzoxazine compounds have been employed satisfactorily to produce prepregs, laminates, PWB's, moulding compounds, sealants, sinter powders, cast articles, structural composites parts and electrical and electronic components by impregnating operations and infusion processes. Such resins are dimensionally stable and have good electrical and mechanical resistance, low shrinkage, low water absorption, medium to high glass transition temperatures and good retaining properties, in terms of mechanical properties.
[0003] Benzoxazine compounds can be produced in several ways. First of all, by using a process based on solvents cf. U.S. Pat. No. 5,152,993 or U.S. Pat. No. 5,266,695. Secondly, as for example described in U.S. Pat. No. 5,543,516, the preparation of benzoxazines is disclosed without using solvents.
[0004] The flame resistance, despite the fact that it compares favorably with that of other polymeric resins resistant to high temperatures, such as for instance epoxy resins is still not sufficient for many uses. In order to make benzoxazines flame retardant the addition of bromine, phosphorous, chlorine containing compounds, fillers or the use of special flame retarded backbones in benzoxazines as it is described for example in EP 0458739, EP 356 379, U.S. Pat. No. 5,200,452, U.S. Pat. No. 5,152,939 or in EP 1366053, JP2001220455 is necessary. Very often the offered solutions to make a composition flame retardant is based on inert fillers or halogen containing compounds or other additives which have as a rule one or several drawbacks:
They are not soluble in solvents and hence cause problems in terms of processing. They show poor oxidative stabilities at elevated temperatures. Additives are very often responsible for a decrease of the glass transition levels. Very often poor physical properties of the cured resins are been observed, cf. U.S. Pat. No. 512,939. Toxic gases of combustion may form in case of fire, especially when halogenated compounds are present.
SUMMARY OF THE INVENTION
[0010] It now has surprisingly been found that articles made from specific benzoxazine compounds, formally derived from phenolphthalein, formaldehyde and a primary amine, show a greatly improved flammability while the mechanical properties are maintained. Such benzoxazine compounds are therefore particularly suitable for use in aerospace, industrial, electronics or other applications such as automotive, adhesives, sealants, prepregs and laminates, coatings and PCB's. They can also be processed by using infusion techniques such as RTM or VaRTM.
DETAILED DESCRIPTION OF THE INVENTION
[0011] A first aspect of the present invention is a compound of the general formula
[0000]
[0000] wherein R is, independently from one another, allyl, unsubstituted or substituted phenyl, unsubstituted or substituted C 1 -C 8 -alkyl or unsubstituted or substituted C 3 -C 8 -cycloalkyl. Suitable substituents on said R-groups include amino, C 1 -C 4 -alkyl and allyl. Typically, one to four substituents may be present on said R-group.
[0012] Preferably both substituents R are the same and especially preferred phenyl.
[0013] Another aspect of the present invention is a benzoxazine compound obtainable by reacting, under removal of water, phenolphthalein with formaldehyde and a primary amine,
[0000] whereby the molar ratio of phenolphthalein and formaldehyde is from 1:3 to 1:10, preferred from 1:4 to 1:7, particularly preferred from 1:4.5 to 1:5 and
the molar ratio of phenolphthalein and the primary amine groups is from 1:1 to 1:3, preferred from 1:1.4 to 1:2.5, particularly preferred from 1:2.1 to 1:2.2
[0014] The reaction time can vary widely with reactant concentration, reactivity and temperature. Times desirably vary from a few minutes for solventless to a few hours, e.g. 2 or 10 for diluted reactants. If a water based solution of formaldehyde is used as one reactant then a water miscible organic solvent is sometimes desirable. If one or more reactant is a liquid it may be used to dissolve the other components. If all of the components are solids they may be premixed as solids and then melted or first melted and then mixed. The temperature of reaction can be determined by routine experimentation noting the formation of benzoxazine and less desired products and optimizing temperature and time for a desirable product. Desirable temperatures are from about 0° C. to about 250° C., preferably from about 0 or 50° C. to about 150° C., and most preferred from about 80° C. to about 120° C.
[0015] The benzoxazine synthesis reaction may be conducted at atmospheric pressure or at a pressure up to about 100 psi. In some instances, a reaction carried out under pressure constitutes a preferred mode since fewer byproducts are produced. When a polyfunctional benzoxazine is being prepared, higher pressures generally results in relatively higher amounts of difunctional benzoxazine monomers.
[0016] The ultimate reaction mixture contains the desired benzoxazine monomer, which may be present as an open ring structure depending, for example, on the ratio of educts, and oligomers thereof, as well as impurities. If desired, the mixture may be purified to obtain a more concentrated form of the product described, for example by well-known crystallization or solvent washing techniques.
[0017] Examples of primary amines that are particularly useful include:
[0018] Aromatic mono- or di-amines, aliphatic amines, cycloaliphatic amines and heterocyclic monoamines; specifically, Aniline, o-, m- and p-phenylene diamine, benzidine, 4,4′-diaminodiphenyl methane, cyclohexylamine, butylamine, methylamine, hexylamine, allylamine, furfurylamine ethylenediamine, and propylenediamine. The amines may, in their respective carbon part, be substituted by C 1 -C 8 -alkyl or allyl.
[0019] Preferred primary amines are according to the general formula RNH 2 (II), wherein R is allyl, unsubstituted or substituted phenyl, unsubstituted or substituted C 1 -C 8 -alkyl or unsubstituted or substituted C 3 -C 8 -cycloalkyl. Suitable substituents on said R-group include amino, C 1 -C 4 -alkyl and allyl. Typically, one to four substituents may be present on said R-group.
[0020] Preferably R is phenyl.
[0021] Preferably, the reaction is carried out in the absence of a catalyst.
[0022] Typically the reaction is carried out in a solvent. Suitable solvents include: aromatic solvents, like toluene and xylene, dioxane, ketones, like methylethylketone, methyl-isobutylketone, and alcohols, like isopropanol, sec-butanol and amyl alcohol. The sovents may also be used as a solvent mixture. Particularly suitable solvents are toluene and sec-butanol. However, in analogy to known reactions from the literature, a solvent may be dispensed with.
[0023] By thermally curing said benzoxazine compounds at temperatures above 100° C., preferably at a temperature from 140° to 220° C., difficultly inflammable (flame retarded) polymeric resins are obtained.
[0024] Another aspect of the present invention is the use of a benzoxazine compound, as described before, in the process of preparation of flame retarded castings, prepregs or laminates and infusion systems as well.
[0025] Flame retarded in the context of the present invention means, preferably, meeting the UL 94 standard (“Underwriters Laboratory” test method UL 94) criterion V0.
[0026] The properties of the polymeric resins produced as described above can be tailored for certain applications by addition of usual additives. The following additives are of particular importance:
[0000] reinforcement fibers, such as glass, quartz, carbon, mineral and synthetic fibers (Keflar, Nomex), natural fibres, such as (flax, jute, sisal, hemp) in the usual forms of short fibers, staple fibers, threads, fabrics or mats;
plasticizers, especially phosphorus compounds;
carbon black or graphite;
fillers;
dyestuffs;
micro hollow spheres;
metal powders.
[0027] The processes known for thermosetting resins, such as phenol formaldehyde resins or epoxy resins, such as hot-pressing of prepregs, SMC (Sheet Molding Compound); or molding; casting; filament winding; infusion techniques or vacuum impregnating (RTM, VaRTM) are suitable for processing the resins according to the invention. With respect to vacuum impregnating, very fine additives having a particle size of 0.2 to 0.001 mm are particularly suitable.
[0028] Another aspect of the present invention is a laminating composition comprising 30 to 80% by weight, preferably 60 to 70% by weight, of a benzoxazine compound as described above. In addition, the laminating composition will typically contain a solvent or solvent mixture, a catalyst or a combination of catalysts and a flame retardant.
[0029] The weight of a flame retardant used in a formulation will depend upon the effectiveness of that component in the formulation in achieving the desired V0 criterion according to UL-94 standard. A weight range of 0.1 to 50 parts by weight has to be taken into account.
[0030] Examples of solvents that are particularly suitable include methylethylketone, acetone, N-methyl-2-pyrrolidone, N,N-dimethyl formamide, pentanol, butanol, dioxolane, isopropanol, methoxy propanol, methoxy propanol acetate, dimethylformamide, glycols, glycol acetates and toluene, xylene. The ketones and the glycols are especially preferred. Typically, the laminating composition will contain 20 to 30% by weight, preferably 30% by weight, of a solvent.
[0031] Examples of catalysts that are particularly suitable include thiodipropionic acid, phenols, thiodiphenol benzoxazine and sulfonyl benzoxazine, sulfonyl diphenol. Certain flame retardants, for example Fyroflex PMP and CN 2465, will act as catalysts. The catalyst concentration will also depend on the effectiveness of that component in achieving the desired reactivity. Typically, the laminating composition will contain 0.001-2, preferably 0.1-2% by weight of a catalyst
[0032] Examples of flame retardants that are particularly suitable include: phosphorous flame retardants, such as DOPO (9,10-dihydro-9-oxa-phosphaphenanthrene-10-oxide), fyroflex PMP (Akzo; a reactive organophosphorus additive modified with hydroxylgroups at its chain ends and able to react with epoxy resins), CN2645A (Great Lakes; a material which is based on phosphine oxide chemistry and contains phenolic functionality able to react with epoxy resins), and OP 930 (Clariant), brominated polyphenylene oxid and ferrocene. Typically, the laminating composition will contain 0.1 to 50% by weight of a flame retardant. For example, for ferrocene an amount of about 2% by weight is particularly suitable.
[0033] Also, the laminating composition may contain an epoxy resin. The selection of the epoxy resins depends on the property enhancement that is needed. Typical epoxy resins that are especially useful are bisphenol A and bisphenol F based epoxy resins, epoxy cresol novolac, epoxy phenol novolac, Tactix 742, Tactix 556, and Taxtix 756, cycloaliphatic epoxy resins, PT 810, MY 720, MY 0500, etc. They may be used in amounts of about 2% to 60% by weight in the laminating composition.
[0034] Typically, the laminating compositions will contain about a minimum of 2 parts of epoxy resin to every 8 parts of benzoxazine up to a maximum of 9 parts of epoxy resin to one part of benzoxazine
[0035] Beyond this, it is possible to incorporate fillers like ammonium polyphosphates and inorganic and organic phosphorus compounds a described in EP 356379 and U.S. Pat. No. 5,200,452.
[0036] The laminating compositions are useful to make electrical laminates and other composites from fibrous reinforcement and a matrix resin. Examples of suitable processes usually contain the following steps:
Solvent Based Impregnation Process
[0037] (1) A benzoxazin-containing formulation is applied to or impregnated into a substrate by rolling, dipping, spraying, other known techniques and/or combinations thereof. The substrate is typically a woven or nonwoven fiber mat containing, for instance, glass fibers or paper.
[0038] (2) The impregnated substrate is “B-staged” by heating at a temperature sufficient to draw off solvent in the benzoxazin formulation and optionally to partially cure the benzoxazin formulation, so that the impregnated substrate can be handled easily. The “B-staging” step is usually carried out at a temperature of from 90° C. to 210° C. and for a time of from 1 minute to 15 minutes. The impregnated substrate that results from “B-staging” is called a “prepreg”. The temperature is most commonly 100° C. for composites and 130° C. to 200° C. for electrical laminates.
[0039] (3) One or more sheets of prepreg are stacked or laid up in alternating layers with one or more sheets of a conductive material, such as copper foil, if an electrical laminate is desired.
[0040] (4) The laid-up sheets are pressed at high temperature and pressure for a time sufficient to cure the resin and form a laminate. The temperature of this lamination step is usually between 100° C. and 230° C., and is most often between 165° C. and 190° C. The lamination step may also be carried out in two or more stages, such as a first stage between 100° C. and 150° C. and a second stage at between 165° C. and 190° C. The pressure is usually between 50 N/cm 2 and 500 N/cm 2 . The lamination step is usually carried out for a time of from 1 minute to 200 minutes, and most often for 45 minutes to 90 minutes. The lamination step may optionally be carried out at higher temperatures for shorter times (such as in continuous lamination processes) or for longer times at lower temperatures (such as in low energy press processes).
[0041] (5) Optionally, the resulting laminate, for example, a copper-clad laminate, may be post-treated by heating for a time at high temperature and ambient pressure. The temperature of post-treatment is usually between 120° C. and 250° C. The post-treatment time usually is between 30 minutes and 12 hours.
EXAMPLES
[0042] All tests were performed according to IPC TM 650.
The IPC test methods are the electrical laminate industry standard (The Institute For Interconnection and Pachaging Electronic Circuits, 3451 Church Street, Evanston, Ill. 60203) as follows:
[0000]
Method
IPC-Test Method Number:
Reactivity (varnish)
IPC-TM-650-5.410
Rest Gel time at 170° C., seconds
IPC-TM-650-2.3.18
Mil Flow, weight percent
IPC-TM-650-2.3.17
Glass Transition Temp., T g [° C.]
IPC-TM-650-2.4.25
Copper Peel Strength
IPC-TM-650-2.4.8
Pressure Cooker Test, weight percent
IPC-TM-650-2.6.16
water pick-up & percent passed solder
bath at 260° C.
UL-94 Standard
IPC-TM-650-2.3.10
A) Preparation of 3,3′-bis(3,4-dihydro-3-phenyl-2H-1,3-benzoxazin-6-yl)-1(3H)-isobenzofuranone
[0044] In a 22 liters glass jacketed Belatec reactor fitted with an addition funnel, thermocouple and a condensor 3884.1 g (12.2 mol) of phenoplphthalein is charged. Subsequently the reactor is charged with 1721.5 g (59.3 mol) of paraformaldehyde, 2420 ml of xylene and 4840 ml of sec-butanol under stirring (ca. 350 rpm). That reaction mixture is preheated to 80° C.-82° C. with stirring.
[0045] 2383.7 g (25.6 mol) aniline is added over a period of 45 min to 1 hour with simultaneous heating to the refluxing point at 94-95° C., maintaining intensive refluxing with separation of water.
[0046] When 25% of the solvents are removed, additionally 600 ml of xylene and 1200 ml sec-butanol are slowly added to the reaction mixture such that the drop of the reaction temperature is minimized. The xylene/sec.-butanol/water azeotrope distills at a higher temperature as the water is removed, so the temperature must be increased to maintain a steady distillation rate. After the water removal is complete, the condensor is replaced by with a distillation head and a receiver.
[0047] When the boiling temperature reaches a value of 100-105° C. (within 6-7 hours of the initial reflux), the water removal and condensation process is over, and the solvent distillation is started until the temperature of the solution is 120° C.-122° C. (no vacuum is applied). At this point the concentration of the solids is determined. At a concentration of 70.5% to 71.5% of solids the process is over and the product can be discharged or used for the preparation of the laminating composition in the same reactor.
[0048] Melting point: 98-103° C.
[0049] 1 H-NMR (d 6 acetone):
δ=4.59 ppm (s); δ=5.4 ppm (s); δ=6.5-7.3 ppm (m); δ=7.5 ppm (m);
[0052] Infrared spectrum (KBr pill) IR (neat): 3600 cm −1 -3150 cm −1 ; 3100 cm −1 -3000 cm −1 ; 2950 cm −1 ; 2850 cm −1 ; 1750 cm −1 ; 1600 cm −1 ; 1450 cm −1 ; 1220 cm −1 ; 1090 cm −1 ; 950 cm −1 ; 725 cm −1 ; 650 cm −1 .
B) Neat Resin Castings
[0053] Neat resin castings for flammability testing are made from the benzoxazine obtained according to example A). The benzoxazine is melted, degassed and poured into a mold. The resin in the mold is then cured for 2 hours at 400° F. (215.5° C.) to produce a casting suitable for testing. These castings are evaluated for their flammability resistance and thermal properties.
[0054] Flammability testing is done by using a UL 94 flammability test chamber. The chamber is equipped with a Bunsen burner supplied with industrial grade methane.
[0055] All testing is done as per UL 94 test. Five specimens per sample are cut to 5 inch×0.5 inch×0.12 inch.
[0000]
TABLE 1
UL 94 Flammability Testing of Neat Resin Castings
1 st Burn
2 nd Burn
Average
Average
Average
Burn Length,
UL 94
Resin
Time, [s]
time, [s]
[inch]
rating
Bisphenol A
31.0
19.2
4.2
HB
benzoxazine
Phenolpthalein
4.9
2.0
0.3
V0
benzoxazine
[0056] The phenolphthalein benzoxazine casting (resin prepared according to Example A) meets the V0 criterion whereas a bisphenol A benzoxazine casting (resin prepared in analogy to Example A but replacing phenolphthalein with bisphenol A) failed.
C) Laminates
[0057] Benzoxazine fiberglass laminate composites are made by the solvent impregnating process. The benzoxazine is dissolved into a solvent along with a soluble catalyst and then coated onto 7628, an industry standard fiberglass weave type as defined by the glass strands, thickness and weight of the glass weave (Porcher SA, with a silane finish). The solvent is then evaporated and B-staged (Table 3). The prepreg with copper is then laminated under heat and pressure to produce a copper clad laminate. The temperature of the hot air in the oven is 150-180° C. and the times to generate the B-stage range in-between 2-5 seconds. The resin content ranges in-between 35-42%. These laminates are then evaluated for their thermal and flammability properties (Table 4).
[0058] All properties are based on 8 plies 7628 glass fabric laminate as per IPC TMI 3949, except for burning behavior and dielectric analysis. The laminates always have the fiberglass plies oriented such that all plies are laid in the same fill and warp direction.
[0000]
TABLE 2
Laminating Compositions:
A
B
1-Pentanol
3%
1-Butanol
3%
2-Butanone
27%
27%
Ferrocene
4%
4%
1,1,2,2-Tetrakis(4-glycidyloxy
6%
6%
phenyl)ethane
3,3-bis(3,4-dihydro-3-phenyl-2H-1,3-
60%
60%
benzoxazin-6-yl)-1(3H)-
isobenzofuranone
[0059] To the composition, 2 parts by weight of methylimidazol is added as a catalyst.
[0060] Typical Solution Properties for A:
[0000] Viscosity: [cps]: 1000-3000
Solids [%]: 69-71
[0061] Appearance: clear amber liquid
Solvent: Methylethylketone and 1-Pentanol [up to 5%]
[0062] The composition A can be formulated with any solvent typically used to manufacture prepregs for PWB applications. Dilution can be done with acetone, MEK; glycols, glycol acetates, toluene, and other solvents.
[0000]
Varnish compositon
Component
Formulation
Composition A
100 phr
2-Methylimidazol
0.4-0.8 phr
Varnish solids
40-60%
Gel time 171° C., [s]
150-200
[0000]
TABLE 3
Initial Press Temperature
room temperature
Heating rate, ° C./min
3-5
Pressure, psi
≧100
Final Press Temperature
190° C.-200° C.
Time at press temperature
120 minutes
Post cure [2 hours]
240° C.-250° C.
[0000]
TABLE 4
Test
Value
Thermal properties
Glass Transition Temperature, ° C.
DSC
190-305
TMA
170-180
Thermal Oxidative Stability
T260
TMA
>30 Minutes
T288
TMA
>30 Minutes
Solder float at 260° C.
>20 Minutes
pass/no
degradation
Decomposition
TGA
325° C.
(Burning behaviour)
UL-94
V0
Chemical Properties:
Water absorption
24 hours
0.03%
Pressure cooker (2 atm, 121° C.)
2 hours
pass
Laminating Compositon C
[0063]
[0000]
Phenolpthalein Benzoxazine
20%
Tactix 742
32%
GY281
12%
Fyroflex PMP
12%
XB4399
4%
Methoxy propanol
10%
MEK
10%
Trithiotriazine
0.5 phr
[0064] Tactix742 is tris(phenylglycidylether)methane.
[0065] GY281 is bisphenol F epoxy resin.
[0066] Fyroflex PMP is a phosphorous based phenol Flame Retardant from Akzo.
[0067] XB4399 is 1,1,2,2-tetrakis(4-glycidyloxyphenyl)ethane.
Typical Solution Properties
[0068]
[0000]
Viscosity, cps
5000-10000
Solids %
79-81
Appearance
Clear amber liquid
Solvent
MEK 10% & Methoxy propanol 10%
Epoxy Equivalent Weight
450-550 [on solids]
Phosphorus content %
2-3
Varnish Preparation
[0069] The system can be formulated with any solvent typically used to manufacture prepregs for PCB applications. To the varnish, 2-Methyl-imidazol is added as a catalyst. The recommended formulation is
[0000]
Component
Formulation
Formulation C
100 phr
2-Methylimidazol
0.002-0.1 phr
Varnish solids
50-65%
Gel time 171° C., [s]
110-400
[0070] Dilution of the system can be performed with acetone, MEK, glycols, glycol acetates, and other solvents.
[0071] For optimum bonding between resin and glass, it is recommended that a glass fabric treated with a silane-sizing agent suitable for epoxy resins is used.
[0000] Typical Prepreg properties:
[0000]
Glass Cloth
7628
Finish
CS440
Resin Content, %
35-42
Mil Flow, %
15-20
Gel Time at 171° C.
75-110
Press Cycle:
[0072]
[0000]
Initial Press Temperature
room temperature
Heating rate, ° C./min
3-5 min
Pressure, psi
50-150
Final Press Temperature
205° C.-218° C.
Time at Press Temperature
90-120 Minutes
[0073] Laminate Properties:
[0074] All properties are based on 8 plies 7628 glass fabric laminate as per IPC TMI 3949, except for burning behavior and dielectric analysis for which neat resin castings are used as described above.
[0000]
Test
Value
Thermal Properties
Glass Transition Temperature, ° C.
DSC
210-235
Thermal Oxidative Stability
T260
TMS
>60 minutes
T288
TMA
>5 minutes
Solder float at 260° C.
>20 Minutes
pass
Solder Foat at 288° C.
5 Minutes
pass
Decomposition, ° C.
TGA
340° C.
Burning Test
UL-94
V0
Chemical Properties
Pressure Cooker
2 hours
pass | The instant invention relates to 3,3′-bis(3,4-dihydro-3-phenyl-2H-1,3-benzoxazin-6-yl)-1(3H)-isobenzofuranone and analogues based on phenolphthalein, formaldehyde and a primary amine. Such compounds are, when cured to form polymeric networks, difficultly inflammable and resistant to high temperatures. Such compounds may especially be used in the production of printed wiring boards. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of and incorporates by reference prior filed copending U.S. Provisional Application Serial No. 60/466,277, Filed Apr. 30, 2003.
BACKGROUND OF THE INVENTION
SUMMARY OF THE INVENTION
[0002] A concealed holster for a weapon such as a pistol, characterized by a downwardly-extending holster pocket of selected material, size and shape for typically mounting on a belt and receiving the barrel of the pistol, and a preferably resilient grip receiver extending upwardly from the holster pocket and having a face recess or inlay for receiving and recessing the grip and action of the pistol. An auxiliary case is attached to the grip receiver for simulating or actually carrying a radio, cellular telephone, pager, compact disc player or the like. The holster pocket is designed to fit between the lower torso clothing, such as slacks or pants, and the leg, abdomen or side of the user, with the grip receiver and auxiliary case projecting above the belt. This facilitates concealing the holster pocket inside the pants or slacks and the pistol inside the holster pocket and the grip receiver, while revealing only the auxiliary case, ostensibly as a carrier for the cellular telephone or the like. The pistol is accessed by forcing the grip receiver outwardly with the bendable or yieldable auxiliary case to clear the pistol grip and action from the recessed face inlay in the grip receiver and allow rapid withdrawal of the pistol from the grip receiver and the holster pocket by the user. Other weapons such as knives, “stun guns” and the like can be hidden in a concealed holster designed to receive such weapons according to the teachings of this invention.
BRIEF DESCRIPTION OF THE SUMMARY
[0003] The invention will be better understood by reference to the accompanying drawings, which are illustrative of a concealed holster for concealing a pistol, wherein:
[0004] [0004]FIG. 1 is an outside perspective view of a preferred embodiment of the concealed holster of this invention mounted on the belt of a user by means of a belt clip;
[0005] [0005]FIG. 2 is an enlarged perspective view of a typical belt clip attached to the holster pocket of the concealed holster and the belt, as illustrated in FIG. 1;
[0006] [0006]FIG. 3 is an inside perspective view of the concealed holster illustrated in FIG. 1, more particularly illustrating a preferred design of the grip receiver, showing the pistol grip and action recessed in a face inlay provided in the typically resilient grip receiver face, to facilitate rapid access to the pistol by a user;
[0007] [0007]FIG. 4 is a top view of the concealed holster illustrated in FIGS. 1 and 3;
[0008] [0008]FIG. 5 is a front view of the concealed holster illustrated in FIGS. 1, 3 and 4 ;
[0009] [0009]FIG. 6 is an inside view of the concealed holster illustrated in FIG. 3;
[0010] [0010]FIG. 7 is an outside view of the concealed holster illustrated in FIG. 1;
[0011] [0011]FIG. 8 is a perspective view of the concealed holster illustrated in FIGS. 1 and 3- 7 , with the holster pocket concealed between the slacks or pants of a user and the user's body, with the auxiliary case exposed and the hand of the user reaching for the concealed pistol;
[0012] [0012]FIG. 9 is a perspective view of the concealed holster illustrated in FIG. 8, more particularly illustrating the user gripping the pistol as the grip receiver and the auxiliary case are pivoted outwardly in concert by the user's hand;
[0013] [0013]FIG. 10 is a perspective view of the concealed holster illustrated in FIG. 9, more particularly illustrating further withdrawal of the pistol from the concealed holster responsive to pivoting of the grip receiver and auxiliary case away from the user's body; and
[0014] [0014]FIG. 11 is a perspective view of the concealed holster illustrated in FIG. 10, more particularly illustrating complete withdrawal of the pistol from the concealed holster.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0015] Referring initially to FIGS. 1-7 of the drawings, in a preferred embodiment the concealed holster of this invention is generally illustrated by reference numeral 1 . The concealed holster 1 is designed to conceal a pistol and is typically constructed of leather, plastic or other resilient material and includes a downwardly-extending, shaped holster pocket 2 , typically having a pocket break 2 a in the rear surface, or pocket back 6 . The holster pocket 2 is further characterized by pocket sides 3 , joined by a pocket front 4 and the pocket back 6 and terminating at a pocket bottom 5 , as illustrated. A grip receiver 7 extends from the top of the holster pocket 2 and may be constructed in one piece with the holster pocket 2 or connected to the holster pocket 2 by glue, brads or other fasteners, as desired. The grip receiver 7 is further characterized by grip receiver sides 8 , which are typically substantially coterminous with the pocket front 4 and the pocket back 6 , respectively, of the holster pocket 2 and the grip receiver 7 includes a downwardly-tapered grip receiver top 9 that spans the top of the grip receiver sides 8 , as further illustrated in FIGS. 1 and 3 of the drawings. A typically resilient grip receiver face 10 is provided in the inside face of the grip receiver 7 and is bounded by the grip receiver sides 8 and the grip receiver top 9 , as further illustrated in FIG. 3 of the drawings. A face inlay 11 is provided in the grip receiver face 10 and is shaped to receive the pistol grip 27 and action 28 of an automatic pistol 26 , as further illustrated in FIG. 3. Accordingly, it will be appreciated that the pistol grip 27 and the action 28 of the pistol 26 are recessed in the face inlay 11 of the resilient, typically expanded foam grip receiver face 10 , when the concealed holster 1 is positioned in functional configuration illustrated in FIG. 3, for the purpose hereinafter described.
[0016] Referring now to FIGS. 1 and 5- 8 of the drawings a pivot, tilt or hinge line 12 is defined by the resilient (typically leather or plastic) case bottom 16 of an auxiliary case 13 and the top edge of the belt 20 . The auxiliary case 13 is attached to the grip receiver 7 by glue, brads or other fasteners, and may also be similarly attached to the holster pocket 2 , to facilitate pivoting, bending and/or tilting of the case bottom 16 of the auxiliary case 13 and the grip receiver 7 in concert along the hinge line 12 at the belt 20 , upon reaching for and grasping the pistol 26 , as hereinafter further described. The auxiliary case 13 is further typically defined by case sides 14 , a case front 15 and a case flap 17 that extends over the top of the auxiliary case 13 to define a flap hinge and is typically releasably attached to the case front 15 by means of a flap closure 18 , such as a snap or the like.
[0017] As further illustrated in FIGS. 1-3 of the drawings, in a preferred embodiment of the invention the holster pocket 2 of the concealed holster 1 is attached to the belt 20 by means of a belt clip 21 , having spaced-apart belt legs 22 that extend from a pocket mount 24 , mounted by any suitable means on the pocket side 3 of the holster pocket 2 , across the top and downwardly across the outside face of the belt 20 . The belt clip 21 is further characterized by a pocket leg 23 that also extends from the pocket mount 24 on the holster pocket 2 and projects around the bottom of the belt 20 and upwardly between the belt legs 22 , as illustrated in FIG. 2 of the drawings, to removably mount the concealed holster 1 on the belt 20 .
[0018] In operation and referring now to FIGS. 3 and 8- 11 of the drawings, in FIG. 8 the concealed holster 1 is illustrated in mounted position on the belt 20 of a user, with the pistol 26 in concealed configuration and the holster pocket 2 extended and concealed between the slacks 25 and the torso of the user, with the auxiliary case 13 and grip receiver 7 protruding above the belt 20 . As described above, the holster pocket 2 is typically connected to the belt clip 21 and the belt clip 21 , to the belt 20 . The user's hand is illustrated in functional configuration moving downwardly as indicated by the arrow, to position the fingers between the grip receiver 7 and the user's side, with the knuckles located adjacent to the grip receiver face 10 , illustrated in FIG. 3. As illustrated in FIG. 9 the hand is further extended downwardly to project the fingers between the grip receiver 7 and the user's side or torso and force the grip receiver 7 and the auxiliary case 13 in concert outwardly in the direction of the arrow, as the user's hand grasps the pistol grip 27 and the auxiliary case 13 bends, pivots and/or tilts along the hinge line 12 (FIG. 8). This movement facilitates gripping of the pistol grip 27 and removal of the pistol grip 27 and the action 28 from the face inlay 11 of the grip receiver face 10 , as the grip receiver 7 and auxiliary case 13 are pivoted or otherwise deflected further outwardly along the hinge line 12 , further illustrated in FIG. 8. The user's arm is now ready to move upwardly and draw the pistol 26 from the holster pocket 2 of the concealed holster 1 . As illustrated in FIG. 10 of the drawings, the pistol 26 is substantially retrieved from the concealed holster 1 , with the barrel 29 extended from the holster pocket 2 and the grip receiver 7 and auxiliary case 13 further pivoted or deflected outwardly above the belt 20 , as indicated by the arrow, to facilitate upward movement of the user's arm and allow complete, full and rapid clearance of the pistol 26 from the concealed holster 1 . FIG. 11 further illustrates complete removal of the pistol 26 from the concealed holster 1 with the grip receiver 7 and auxiliary case 13 returned to substantially the same configuration illustrated in FIG. 8 on the hinge line 12 , as a result of the “memory” in the resilient auxiliary case 13 .
[0019] It will be appreciated from a consideration of the drawings and the above description that the concealed holster of this invention is designed for use under circumstances where it is desired to conceal a weapon such as a handgun of any design, the automatic pistol 26 being shown in the drawings for illustrative purposes only. It will be further understood, that depending upon the design of the weapon to be concealed, including a knife, “stun gun”, automatic pistol or revolver or other weapon, the holster pocket 2 , face inlay 11 and grip receiver 7 can be shaped to accommodate any such weapon, as desired. Furthermore, as illustrated in FIG. 8 of the drawings, under circumstances where the concealed holster 1 is positioned in weapon-concealed configuration, only the auxiliary case 13 , the grip receiver sides 8 and the grip receiver top 9 are presented in full view of an observer and since the pistol grip 27 and action 28 illustrated in the drawings are recessed in the face inlay 11 of the grip receiver face 10 , the pistol grip 27 and action 28 are not visible. The holster pocket 2 , containing the barrel 29 of the pistol 26 , is also concealed, as it is extended downwardly between the slacks 25 and the torso of a user, to completely conceal the pistol 26 inside the holster pocket 2 and the grip receiver 7 . Accordingly, the concealed holster 1 of this invention features three-dimensional concealment of a weapon, with quick access to the weapon, without the necessity of wearing additional concealment devices, including clothing.
[0020] Furthermore, the auxiliary case 13 can be utilized to contain a cellular telephone or a radio, pager, compact disc player or the like (not illustrated) or can remain empty, to simulate such containment, as desired. Moreover, the size and shape of the auxiliary case 13 can be varied as desired, to further enhance concealment of the desired weapon. It will be further understood by those skilled in the art that the holster pocket 2 can be shaped and sized as desired to contain a weapon such as a knife having a blade of selected length, a “stun gun” or a pistol 26 having a desired barrel length and design, for example, a revolver having a longer or shorter barrel than the pistol 26 illustrated in the drawings. The holster pocket 2 , grip receiver 7 and/or the auxiliary case 13 can also be typically constructed of leather or other resilient material such as plastic and the like, in non-exclusive particular, according to the weapon size, shape and design and the desires of the manufacturer and the user.
[0021] While the preferred embodiments of the invention have been described above, it will be recognized and understood that various modifications may be made in the invention and the appended claims are intended to cover all such modifications which may fall within the spirit and scope of the invention. | A concealed holster for a weapon, characterized by a holster pocket typically mounted on the belt of a user for receiving a weapon such as the barrel of a pistol, a typically resilient grip receiver extending upwardly from the holster pocket for receiving and concealing the pistol grip and action in recessed configuration and a resilient or pivotal auxiliary case attached to the grip receiver for containing or simulating containment of a cellular telephone, radio or the like, wherein the holster pocket is designed to fit inside the slacks or pants of the user, with the auxiliary case and grip receiver extending above the belt, to facilitate quick access to the concealed pistol by forcing the grip receiver away from the pistol grip and action as the auxiliary case is pivoted outwardly, grasping the pistol grip and drawing the pistol from the holster pocket. | 0 |
FIELD OF THE INVENTION
The present invention relates to a power supply assembly to be used in, for example, a semiconductor testing system, for finding an error against a set voltage by feeding back an applied voltage applied to a load (for example, a device as a test subject), and applying a predetermined voltage to the load by causing an output amplifier to increase and decrease amperage to be fed to the load on the basis of the error, and a semiconductor testing system using the same, and more particularly, to a power supply assembly that can be miniaturized even though a voltage applied to a load is rendered variable, and a semiconductor testing system using the same.
BACKGROUND OF THE INVENTION
With a semiconductor testing system (including so-called an IC tester, LSI tester, and so forth; hereinafter referred to merely as a tester), it is necessary to supply a device as a test subject {hereinafter referred to as a DUT (Device Under Test)} with a voltage with high precision in order to inspect and test the DUT with good precision. Accordingly, a tester is provided with a power supply assembly capable of outputting a voltage with high precision. Determination on whether or not a DUT is acceptable has been made by taking measurements on current flowing from the power supply assembly to the DUT. The DUT includes, for example, an IC, LSI, and so forth (refer to, for example, Patent Document 1).
FIG. 6 is a block diagram showing a configuration of a tester using a conventional power supply assembly.
In FIG. 6 , a power supply assembly 100 is installed in a tester main body, and comprises a voltage buffer 1 , a DAC 2 , an error amplifier 3 , an output amplifier 4 , a current detection circuit 5 , and a current measurement circuit 6 , wherein the power supply assembly 100 outputs voltage and current to a DUT 7 while monitoring a level of a voltage applied to the DUT 7 .
The DUT 7 is a load, and has a plurality of terminals for input/output, and a predetermined voltage Vout is applied from the power supply assembly 100 to a desired terminal (a DUT terminal). Further, the DUT 7 is placed on the top of a performance board (not shown) of a test head (not shown) of the tester.
The voltage buffer 1 has a noninverting input terminal, to which an applied voltage Vout to the DUT 7 is inputted. The DAC 2 is a kind of a voltage generation circuit, and outputs a predetermined set voltage Vout. An output voltage from the voltage buffer 1 , and an output voltage from the DAC 2 are inputted to the error amplifier 3 .
An error signal from the error amplifier 3 is inputted to the output amplifier 4 , which either increase or decrease amperage to the DUT terminal of the DUT 7 , thereby applying a voltage Vout as corrected by an error portion to the DUT 7 . Further, with the output amplifier 4 , an output terminal is connected to an inverting input terminal. Still further, the output amplifier 4 is driven by a power supply voltage (voltage level: VDD on the plus side, and VEE on the minus side) from a power supply unit U 1 . In this case, the power supply unit U 1 constantly outputs a voltage at a given level regardless of an output voltage, and an output current of the output amplifier 4 .
The current detection circuit 5 is provided between the output amplifier 4 , and the DUT 7 . The current measurement circuit 6 takes measurements on current by the agency of a signal from the current detection circuit 5 . Further, the power supply voltage from the power supply unit U 1 is also fed to the voltage buffer 1 , the DAC 2 , the error amplifier 3 , the current detection circuit 5 , and so forth, although not shown in the figure.
Operation of the tester is described hereinafter.
The DAC 2 outputs the predetermined set voltage Vout. A voltage signal from the DAC 2 is inputted to a noninverting input terminal of the error amplifier 3 , and a voltage being applied to the DUT 7 is inputted to an inverting input terminal of the error amplifier 3 via the voltage buffer 1 , as being fed back.
Further, the error amplifier 3 amplifies an error within a amplifier 4 . Then, the output amplifier 4 increases or decreases the amperage fed to the DUT 7 on the basis of the error signal from the error amplifier 3 so as to reduce a voltage error at the error amplifier 3 . That is, the set voltage of the DAC 2 is used as a reference.
The applied voltage to the DUT 7 , after varied by an increase or a decrease in amperage, is fed back again to the error amplifier 3 via the voltage buffer 1 , and the error amplifier 3 detects an error. Further, the output amplifier 4 causes an increase or a decrease in amperage so as to reduce the error. Thus, a level of the voltage applied to the DUT 7 is finally rendered equivalent to that of the set voltage Vout of the DAC 2 to be subsequently maintained.
Meanwhile, the current detection circuit 5 converts current applied to the DUT 7 into voltage, and an ADC (not shown) of the current measurement circuit 6 executes A/D conversion of the voltage to be then outputted to a determination circuit (not shown) in a later stage, whereupon the determination circuit determines whether or not the DUT 7 is acceptable.
FIG. 7 is a block diagram showing a configuration of a tester with a plurality of channels of the power supply assemblies 100 mounted therein. The power supply assemblies 100 each apply a voltage to different terminals of a DUT 7 , however, the power supply voltage (VDD, VEE) from the same power supply unit U 1 is supplied to respective output amplifiers 4 .
Further, a primary cause for occurrence of the error between the set voltage of the DAC 2 , and the applied voltage to the DUT 7 is occurrence of a potential difference between a preference potential of the DAC 2 , and a reference potential of the DUT 7 . The DUT 7 is normally connected to the ground at a reference potential of a whole tester (the reference potential of the DAC 2 as well is equivalent to the ground potential as the reference potential of the whole tester). Upon flow of current at a large amperage to the DUT 7 , however, a voltage drop occurs to a signal line form the DUT 7 to the ground. Accordingly, the reference potential of a system ground differs from the reference potential of the DUT 7 (voltages at respective terminals of the DUT 7 , at the reference potential thereof), thereby causing a difference between the reference potential of the DAC 2 , and the reference potential of the DUT 7 . Other causes for the error include, for example, a voltage drop accompanying resistance in flow paths up to the current detection circuit 5 , and up to the DUT 7 , respectively.
[Patent Document 1] JP 2005-98896 A
With the structure of the power supply assembly and semiconductor testing system using same, the output voltage of the power supply assembly 100 has a variable voltage level, that is, the set voltage that can be outputted by the DAC 2 is rendered variable so as to be able to cope with the kind of a device, and various test items. To give an example of a specification, the output voltage is set in a range of 0 to 10 V. The power supply voltage level of the output amplifier 4 need to have a potential difference equivalent to the output voltage outputted by the output amplifier 4 with a bias voltage added thereto. For example, there is the need for the potential difference ΔV=approx. 5 V. Accordingly, because the level of the power supply voltage (VDD, VEE) supplied to the output amplifier 4 is fixed, the level of the power supply voltage VDD on the plus side need be at least 15 V in order to meet the specification in respect of the output voltage of the power supply assembly 100 .
Further, in the case where a plus current Iout is consumed at the DUT 7 , the current lout is fed to the DUT 7 via a plus side power supply voltage terminal (the voltage level VDD side) of the output amplifier 4 . In the case where a minus current Iout is consumed at the DUT 7 , the current Iout is absorbed from the DUT 7 via a minus side power supply voltage terminal (the voltage level VEE side) of the output amplifier 4 .
And, the power supply voltage levels VDD, VEE (that is, the respective levels of the voltages outputted by the power supply unit U 1 ) of the output amplifier 4 are under control by a constant voltage operation without depending on the set voltage of the DAC 2 , and the current Iout consumed at the DUT 7 .
Now, FIG. 8 is a conceptual view showing consumed power of the output amplifier 4 , as a loss of a plus side output. Assuming by way of example that VDD=15 V, Vout=1 V, and Iout=5 A, power loss at the output amplifier 4 will be 70 W={(the power supply voltage level−the output voltage level)×the output current}. Further, if Vout=0 V, a loss of consumed power will be 75 W at the maximum. Then, the consumed power is released in the form of heat from the output amplifier 4 .
FIG. 9 is a conceptual view showing the total current and output power which the power supply assemblies 100 in whole can output when the plurality of the channels of the power supply assemblies 100 are mounted as shown in FIG. 7 . Assuming by way of example that Vout=10 V (the maximum output level), ΔV=5 V, and rated output power of the power supply unit U 1 =150 W, the total current will be 10 A at the maximum regardless of the set voltage of the DAC 2 , so that the lower the voltage level of the set voltage, the lower will be utilization efficiency of electric power.
In particular, there have lately been seen trends for lower voltage and lager amperage in the case of a device used as the DUT 7 to be measured by a semiconductor testing system. In the case of outputting a large amperage at such a low voltage to the device, a heat release problem with the conventional power supply assembly 100 has posed a very significant problem. Accordingly, a heat release design for the power supply assembly 100 becomes larger in scale, thereby creating causes for an increase in size as well as cost of the power supply assembly 100 .
In addition, because the semiconductor testing system has a multitude of the power supply assemblies 100 , magnitude of heat release becomes significant, and reduction in size of the power supply assembly is difficult to implement, so that there has arisen a problem of difficulty in checking the cost thereof.
SUMMARY OF THE INVENTION
It is therefore an object of the invention to provide a power supply assembly that can be miniaturized even though an applied voltage to a load is rendered variable, and to provide a semiconductor testing system using the same.
In accordance with a first aspect of the invention, there is provided a power supply assembly for finding an error against a set voltage by feeding back an applied voltage applied to a load, and applying a predetermined voltage to the load by causing an output amplifier to increase and decrease amperage to be fed to the load on the basis of the error, wherein a voltage converter causing a voltage level of a power supply voltage of the output amplifier to follow up a voltage level of the set voltage is provided.
The voltage converter preferably comprises a level-shift circuit for adding a bias voltage to the voltage level of the set voltage, and a DC-DC converter for outputting a power supply voltage to the output amplifier on the basis of a voltage level from the level-shift circuit.
The DC-DC converter may be a step-down converter.
The invention in its second aspect provides a semiconductor testing system used for inspection of devices, comprising a power supply unit, and any one of the power supply assemblies described in the foregoing, driven by power supplied from the power supply unit, wherein the load is a device under test.
With some of the power supply assemblies described in the foregoing, the DC-DC converter is a switching power supply, and preferably executes switching control in sync with a clock signal for system control.
The semiconductor testing system preferably comprises a current measurement circuit for taking measurements on current fed from some of the power supply assemblies described in the foregoing to the device under test, and a timing adjuster for causing the switching power supply to stop switching while the current measurement circuit takes measurements on the current.
A plurality of any of the power supply assemblies described in the foregoing may be provided, and electric power may be fed thereto from the same power supply unit.
Further, a plurality of any of the power supply assemblies described in the foregoing may be provided, electric power may be fed thereto from the same power supply unit, and switching control may be executed through synchronization among the power supply assemblies.
The invention has the following advantageous effects.
Since the voltage converter causes the voltage level of the power supply voltage of the output amplifier to follow up the voltage level of the set voltage, consumed power (a loss) at the output amplifier 4 can be rendered constant regardless of an output voltage level of the output amplifier 4 . By so doing, it is possible to suppress heat release, and considerably reduce content of dependency on heat-release designing (for example, heat-release designing is caused to be easy and not to take time, and the power supply assembly is caused to be manufactured with ease), thereby implementing miniaturization in circuit configuration, and reduction in cost as well.
Further, since any of the power supply assemblies described in the foregoing is used in the semiconductor testing system, it is possible to suppress heat release from the power supply assembly, and to considerably reduce content of dependency on heat-release designing, thereby implementing miniaturization of the system as a whole, and reduction in cost as well.
Still further, since the consumed power (the loss) of the output amplifier 4 is constant, rated output power of the power supply unit can be checked even in the case where the plurality of the power supply assemblies are provided, and the output voltage of the output amplifier 4 is low.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a bock diagram showing a first embodiment of a power supply assembly according to the invention;
FIG. 2 is a conceptual view showing consumed power of the output amplifier 4 of the power supply assembly 200 shown in FIG. 1 , as a loss of a plus side power.
FIG. 3 is a conceptual view showing the total current and output power which the power supply assemblies 200 in whole can output when a plurality the power supply assemblies 200 are mounted;
FIG. 4 is a bock diagram showing a second embodiment of a power supply assembly according to the invention;
FIG. 5 is a bock diagram showing a third embodiment of a power supply assembly according to the invention;
FIG. 6 is a block diagram showing a configuration of a semiconductor testing system using a conventional power supply assembly;
FIG. 7 is a block diagram showing a configuration of a semiconductor testing system using a plurality of the conventional power supply assemblies;
FIG. 8 is a conceptual view showing consumed power of an output amplifier 4 of a power supply assembly 100 shown in FIG. 6 , as a loss of a plus side power; and
FIG. 9 is a conceptual view showing the total current and output power which the power supply assemblies 100 in whole can output when a plurality of the channels of the power supply assemblies 100 are mounted.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Preferred embodiments of the invention are described hereinafter with reference to the accompanying drawings
First Embodiment
FIG. 1 is a bock diagram showing a first embodiment of a power supply assembly (when used in a tester) according to the invention. In the figure, parts corresponding to those in FIG. 6 are denoted by like reference numerals, omitting therefore description thereof. In FIG. 1 , a power supply assembly 200 is installed in a tester main body, and is equivalent to a power supply assembly 100 shown in FIG. 6 , additionally provided with a step-down converter (step-down type converter) 8 as a kind of a switching power supply, and a bias power supply 9 .
The step-down converter 8 is a DC-DC converter for stepping down a power supply voltage level VDD from a power supply unit U 1 to thereby convert the same to a voltage level VTR identical to a reference voltage from the bias power supply 9 to be subsequently outputted to a plus side power supply voltage terminal of an output amplifier 4 . In this connection, the step-down converter 8 outputs an output voltage which is lower than an input voltage. The term “lower” in the case means that an absolute value of an amplitude of the input voltage of the converter 8 >absolute value of an amplitude of the output voltage of the converter 8 . For example, if the input voltage to the plus side of the converter 8 is +15 V, the output voltage to the output amplifier 4 is in a range of +5 to +10V while if the input voltage to the minus side of the converter 8 is −15 V, the output voltage a range of −10 to −5 V is outputted. Further, the step-down converter 8 is generally capable of executing power conversion at high efficiency on the order of 95%, and charge current flows to an output side capacitor for smooth rectification for the entire period (both the “on” and the “off” periods of a switching transistor incorporated therein). Accordingly, DC output has small ripples, exhibiting excellent characteristics.
The bias power supply 9 is a level-shift circuit, and adds a bias voltage (a potential difference: ΔV) to a voltage level on a path between an output terminal of an error amplifier 3 , and a noninverting input terminal of the output amplifier 4 , thereby outputting the reference voltage to the step-down converter 8 . In this case, the step-down converter 8 , and the bias power supply 9 make up a voltage converter.
Now, operation of the tester is described hereinafter.
The level-shift circuit 9 adds the bias voltage to a voltage level of an error signal from the error amplifier 3 , thereby generating the reference voltage to be outputted to the step-down converter 8 . Then, the step-down converter 8 converts the power supply voltage level VDD from the power supply unit U 1 into the voltage level VTR identical to the reference voltage, thereby outputting the same as a power supply voltage VTR to the output amplifier 4 . In such a case, the step-down converter 8 preferably executes switching in sync with a clock signal to serve as a base for the power supply assembly 200 . More specifically, with the tester, the clock signal for synchronizing all parts of the tester is fed from a clock unit (not shown) to a DAC 2 and a current measurement circuit 6 of the power supply assembly 200 . And, the step-down converter 8 preferably generates a triangular wave in sync with a frequency of the clock signal on the basis of the clock signal from a clock unit (not shown), thereby switching at a frequency identical to that of the clock signal.
The output amplifier 4 is a voltage buffer that acts as a current drive circuit, and effects one-fold (1×) amplification in terms of voltage. That is, the voltage level of the reference voltage fed to the step-down converter 8 will be equivalent to the voltage level of an output voltage of the power supply assembly 200 (that is, a voltage applied to a DUT 7 ) plus the bias voltage (Vout+ΔV). Further, the output voltage of the power supply assembly 200 is based on a set voltage of a DAC 2 . Accordingly, the voltage level VTR of the power supply voltage fed from the step-down converter 8 to the output amplifier 4 follows up a voltage level of the set voltage of the DAC 2 .
Then, the power supply voltage of the output amplifier 4 will be at the voltage level VTR on the plus side (variable depending on the set voltage), and at the voltage level VEE on the minus side. Further, in the case where the output amplifier 4 causes a plus current Iout to be consumed at the DUT 7 on the basis of an error signal from the error amplifier 3 , the current Iout is fed to the DUT 7 via a plus side power supply voltage terminal (the voltage level VTR side) of the output amplifier 4 . In the case where a minus current Iout is consumed at the DUT 7 , the current Iout is absorbed from the DUT 7 via a minus side power supply voltage terminal (the voltage level VEE side) of the output amplifier 4 .
Respective operations of a voltage buffer 1 , the DAC 2 , a current detection circuit 5 , and the current measurement circuit 6 , other than those parts described as above, are the same as respective operations of those of the assembly shown in FIG. 6 , omitting therefore description thereof.
FIG. 2 is a conceptual view showing consumed power of the output amplifier 4 , as a loss of a plus side power. Assuming that VDD=15 V, Vout=1 V, Iout=5 A, and ΔV=5 V according to the example shown in FIG. 8 , there is obtained VTR=6 V. Then, a power loss at the output amplifier 4 will be constant as follows.
consumed
power
=
(
the
power
supply
voltage
level
VTR
-
the
output
voltage
Vout
)
×
output
current
Iout
=
ΔV
×
output
current
Iout
=
5
V
×
5
A
=
25
W
Further, FIG. 3 is a conceptual view showing the total current and output power which the power supply assemblies 200 in whole can output when a plurality of channels of the power supply assemblies 200 , each as shown in FIG. 1 , are mounted as shown in FIG. 7 . Assuming that Vout=10 V (the maximum output level), bias voltage ΔV=5 V, and the rated output power of the power supply unit U 1 =150 W, according to the example shown in FIG. 9 , the output current Iout will undergo variations according to the set voltage of the DAC 2 . For example, the maximum output current in total will be 10 A at the output voltage Vout=10 V, and the maximum output current in total will increase to 25 A at the output voltage Vout=1 V.
In FIG. 3 , calculation is made on the assumption that the step-down converter 8 has conversion efficiency at 100%. The conversion efficiency is actually on the order of 95%, however, the lower the voltage level Vout of the set voltage, the greater will be improvement on the utilization efficiency of electric power.
Thus, the bias voltage ΔV is added to the set voltage having a variable voltage level by the level-shift circuit 9 , thereby generating the reference voltage. Then, the step-down converter 8 causes the voltage level VTR of the power supply voltage to be identical in level to the reference voltage to be subsequently outputted to the output amplifier 4 , so that consumed power (a loss) at the output amplifier 4 can be rendered constant (ΔV×Iout) regardless of an output voltage level of the output amplifier 4 . By so doing, it is possible to suppress heat release, and considerably reduce the content of dependency on heat-release designing, thereby implementing miniaturization in circuit configuration, and reduction in cost as well.
Further, since the step-down converter 8 feed the output amplifier 4 with the voltage level following up the set voltage, the power supply voltage level VDD of the power supply unit U 1 can be rendered higher. By so doing, respective feed currents flowing through interconnection paths from the power supply unit U 1 to the error amplifier 3 , the output amplifier 4 , the DAC 2 , and so forth, respectively, can be rendered lower in amperage. Accordingly, a tester low in cost can be made up.
Furthermore, since the consumed power (the loss) of the output amplifier 4 is constant, the rated output power of the power supply unit U 1 can be checked even in the case where the plurality of the channels of the power supply assemblies 200 are mounted in a tester, and the output voltage of the output amplifier 4 is low. In other words, it is possible to draw output power out of each of the plurality of the channels of the power supply assemblies 200 without increasing the output power of the power supply unit U 1 . With a tester, there have lately been seen recent trends that the lower the voltage level of the power supply voltage is, the greater will become amperage of current fed from the power supply assembly to the DUT 7 . Hence, the greater the number of the power supply assemblies 200 mounted in the tester, and the lower a level of voltages applied to the DUT 7 , the greater will be improvement on utilization efficiency of the power supply unit U 1 .
Second Embodiment
FIG. 4 is a bock diagram showing a second embodiment of a power supply assembly according to the invention. In the figure, parts corresponding to those in FIG. 1 are denoted by like reference numerals, omitting therefore description thereof. In FIG. 4 , there is newly installed a timing adjuster 10 . The timing adjuster 10 executes adjustments on conversion timing of an ADC (not shown) of a current measurement circuit 6 , and switching timing of a step-down converter 8 , on the basis of a clock signal from a clock unit (not shown). More specifically, the timing adjuster 10 causes the step-down converter 8 to stop switching while causing the current measurement circuit 6 to execute A/D conversion to take measurements on current. For example, the timing adjuster 10 generates an INH signal in sync with the clock signal, and the INH signal causes the current measurement circuit 6 to execute the A/D conversion at its low level timing. Then, the timing adjuster 10 obtains AND between the INH signal and the clock signal to be subsequently outputted to the step-down converter 8 .
That is, with a tester, there is the need for taking measurements on an output current Iout to a DUT 7 with high precision. In taking measurements on the current as described above, the current to the DUT 7 is converted into voltage by a current detection circuit 5 , and the voltage is subjected to A/D conversion by the ADC (not shown) of the current measurement circuit 6 to be then outputted to a determination circuit (not shown) in a later stage. Thereafter, the determination circuit (not shown) determines whether or not the DUT 7 is acceptable. An output of the step-down converter 8 contains voltage noises and current noises due to switching of the step-down converter 8 . In general, voltage noises from the power supply assembly 200 are removed by a capacitor provided at a terminal of the DUT 7 . Meanwhile, when taking measurements on the current of the power supply assembly 200 , accuracy of current measurement will undergo deterioration.
Accordingly, with a circuitry shown in FIG. 4 , the timing adjuster 10 stops switching operation of the step-down converter 8 during current measurement by the current measurement circuit 6 (during A/D conversion of data for use in measurement). As a result, it is possible to reduce the current noises due to the switching of the step-down converter 8 , thereby measuring the output current with high precision.
Further, it is to be pointed out that the invention is not limited in scope to those described as above, but may include the following.
There is shown a configuration wherein the step-down converter 8 causes the plus side power supply voltage level of the output amplifier 4 to follow up the set voltage, however, the minus side power supply voltage level of the output amplifier 4 may be alternatively caused to follow up the set voltage. That is, a configuration shown in FIG. 5 may be adopted. In the figure, parts corresponding to those in FIG. 1 are denoted by like reference numerals, omitting therefore description thereof. In FIG. 5 , a step-down converter 11 , and a bias power supply 12 are additionally provided. The bias power supply 12 generates a reference voltage by adding a bias voltage ΔV to the set voltage. Further, the step-down converter 11 lowers a level of the power supply voltage VEE from a power supply unit U 1 to be converted into a voltage level VTR′ equivalent in level to the reference voltage from the bias power supply 12 to be subsequently outputted to a minus side power supply voltage terminal of the output amplifier 4 . Needless to say, the step-down converter 8 and the bias power supply 9 , for the plus side, may not be provided and only the minus side power supply voltage level of the output amplifier 4 may be caused to follow up the set voltage.
Still further, there is shown the configuration wherein the plurality of the channels of the power supply assemblies 200 are mounted, and electric power is fed thereto from the same power supply unit U 1 , however, there may be provided a switching controller (not shown), so that the switching controller executes switching control for synchronization of the step-down converters among the power supply assemblies 200 .
Yet further, there is shown the configuration where the bias voltage ΔV of the bias power supply 9 is 5 V, however, the potential difference ΔV may be of any other value. Similarly, a range of the output voltage of the power supply assembly 200 , the rated output power of the power supply unit U 1 , and so forth may be of any value.
Further, there is shown the configuration wherein the power supply assembly 200 is provided with the current detection circuit 5 and the current measurement circuit 6 , however, for example, in the case where measurements on current are unnecessary, the current detection circuit 5 and the current measurement circuit 6 need not be provided.
Still further, there is shown the configuration wherein the bias power supplies 9 , 11 are provided by way of example of the level-shift circuit, however, use may be alternatively made of any unit capable of adding a predetermined bias voltage to the set voltage.
Further, there is shown the configuration wherein the power supply assembly 200 is used in a tester, however, the power supply assembly according to the invention is not limited in application to the tester and the load is not limited to the DUT. In other words, the invention may be applied to other cases including the case where high efficiency is intended, the case where a DC amplifier is tested, and so forth. | A power supply assembly that can be miniaturized even though an applied voltage to a load is rendered variable, and a semiconductor testing system using the same are put into practice. With an improvement of the power supply assembly for finding an error against a set voltage by feeding back an applied voltage applied to a load, and applying a predetermined voltage to the load by causing an output amplifier to increase and decrease amperage to be fed to the load on the basis of the error, it is characterized in provided a voltage converter causing a voltage level of a power supply voltage of the output amplifier to follow up a voltage level of the set voltage. | 6 |
BACKGROUND OF THE INVENTION
This invention relates to ice making and more particularly to ice makers for producing pieces of disc shaped ice submerged in a tank of water held at a temperature near freezing. This water becomes the storage medium for the commonly called ice cubes.
This invention employs an external coil evaporator utilizing a liquid refrigerant for freezing and its hot gas state to effect harvesting. External evaporators have previously been employed for producing ice uner water.
An improvement over present coils by the herein disclosed evaporator is the unique configuration of the coil which lends it to lower cost for fabrication and ease of maintenance.
The deformation of the evaporator coil is accomplished by a mechanical press. The coil then is applied to the exterior of the storage tank by clamping, thus eliminating all soldering procedures.
Other methods of attaching the coil to the exterior of the storage tank such as spot welding, cold soldering or similar methods is recognized herewith and considered as common to the art.
The interior freezing surfaces are readily available for cleaning by removing the enclosing head unit and its various components. This configuration provides for a highly compact arrangement which is efficient in initial cost for construction, space requirements for the several elements and also for the energy requirements needed to effect heat transfer from the stored water.
Ice dispensing machines are well known to the art. Most of these devices deliver the ice from a delivery spout attached to the machine. This in many cases is an inconvenience in that a bulky machine or storage bin is required in a convenient location to the user. Often valuable counter space is sacrificed for this equipment.
An improvement over this arrangement is provided by the design of a remote dispensing head requireing comparatively little counter space.
The two embodiments of this invention provide for a compact ice making machine and dispensing head, constructed essentially as set forth in the Abstract, the dispensing head being incorporated in the machine and all suitable for installing in a serving counter line.
SUMMARY OF THE INVENTION
An ice making machine is provided which utilizes an evaporator coil constructed of any suitable material in tubing form which is flattened at intervals and deformed so as to bring these flattened portion of the coil into contact with the exterior surface of the ice/water storage tank. Pure ice cubes are formed on the interior surface of the storage tank at these contact points. The area of these contact points determines the shape and size of the ice cubes. A refrigerant is circulated through this coil until ice of the desired thickness is formed. Upon application of the hot gas harvesting cycle the cubes float to the surface of the water in the storage tank. A circulating pump, located at the surface of the ice/water mixture provides the means for delivering the mixture, by constant circulation, through insulated conduits to the remote dispensing head or heads. When ice is required at any dispensing head a diverter valve is actuated from the head and a controlled quantity of ice is dispensed. The remaining ice/water mixture is returned to the freezing compartment of the ice making machine via a return insulated conduit.
A syrup storage compartment is provided. Syrup is transported through suitable small bore tubing held in contact with the ice/water mixture conduits, thus effectively chilling the syrup as it is delivered to the remote dispensing head. This dispensing head is designed with manual/electric dispensing control valves for ice and syrup dispensing. The electric element of the control valves is designed for use with computer circuitry.
In the first embodiment of the invention the pure ice cubes are formed as set forth in the basic disclosure and the ice/water circulating pump is utilized. The remote dispensing head is replaced by an integral head constructed within the machine cabinet. Internal conduits for transporting the ice/water mixture from the storage tank to the dispensing head are incorporated and the external ice/water conduits are eliminated. The dispensing head is contructed and used as set forth in the basic disclosure.
In the second embodiment of the invention the ice cubes are formed as set forth in the basic disclosure and the ice/water mixture pump is eliminated by the use of carbon dioxide gas to pressurize the ice/water mixture in the storage tank. This produces a carbonated ice/water mixture being suitable for use in the finished beverage is delivered to the dispensing head by pressure of the carbonating gas. A motor driven agitator is utilized for effecting complete carbonation of the stored water. The dispensing head is as set forth in the basic disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric view of an ice making machine embodying various features of the present invention.
FIG. 2 is an isometric view of a remote dispensing unit for use with the ice making machine shown in FIG. 1.
FIG. 3 is a sectional plan of the ice making machine taken generally along the line 1--1 of FIG. 4.
FIG. 4 is a vertical sectional view taken generally along the line 2--2 of FIG. 3.
FIG. 5 is a schematic view of ice/water conduits and syrup conduits connecting the ice making machine to the remote dispensing unit. Also shown is the three-way diverter valve used to divert the ice/water mixture flow either to the dispension head or back to the ice making machine. A return water pump for pumping drained chilled water back to the ice making machine is shown. Also shown is an electrical schmatic view of the control circuitry for operating the diverter valve, return chilled water pump and the syrup valves.
FIG. 6 is a sectional elevation view of the freezing coil.
FIG. 7 is a cross section view of the coil taken on the line 3--3 of FIG. 8.
FIG. 8 is a partial view of the freezing coil.
FIG. 9 is an isometric view of a section of the freezing coil applied to the exterior surface of the ice/water storage tank.
FIG. 10 is a plan view of the manual/electrical variable flow-rate control valve and the associated electric operating solenoid for dispensing water, soda water, syrup, alcoholic beverages and other liquids.
FIG. 11 is a side view of the manual/electric variable flow-rate valve.
FIG. 12 is a front view showing the spring return operator of this valve.
FIG. 13 is a rear view of the valve showing the connecting rod for attaching the electrical operating solenoid.
FIG. 14 is a front elevation view of the operating panel showing the disposition of the manual operating levers of the dispensing valves, the ice delivery chute and liquid dispensing tubing. Also shown is the location of the beverage container and the conveyor belt.
FIG. 15 is a sectional view taken generally along lines 4--4 of FIG. 14.
FIG. 16 is a front view of manual operating lever for the control mechanism for ice dispensing.
FIG. 17 is a sectional view of the complete control mechanism of the manual/electric operating devices taken generally along line 5--5 of FIG. 16.
FIG. 18 is an isometric view of the two emebodiments designed for use in a serving counter line, the remote dispensing units being eliminated.
FIG. 19 is a sectional view of one embodiment taken generally along line 6--6 of FIG. 18.
FIG. 20 is a sectional view taken generally along line 7--7 of FIG. 19.
FIG. 21 is a sectional plan view taken generally along line 8--8 of FIG. 19.
FIG. 22 is a sectional view of the second embodiment taken generally along line 6--6 of FIG. 18.
FIG. 23 is a vertical sectional view taken along line 9--9 of FIG. 22.
FIG. 24 is a plan view taken generally along line 10--10 of FIG. 22.
FIG. 25 is a partial sectional view of the upper portion of the storage tank taken generally along line 12--12 of FIG. 24 showing the control mechanism for the control of the carbon dioxide gas and the water level.
FIG. 26 is a side view of the ice discharger chute with water drain-off tube shown also in FIG. 15.
FIG. 27 is a plan view of the ice discharger chute with water drain-off tube.
FIG. 28 is a schematic electrical diagram showing control wiring of the various components of the basic invention and the two embodiments.
FIG. 29 is a sectional view of manually/electrically operated variable flow-rate dispensing valve 40, taken generally along line 2--2 of FIG. 30.
FIG. 30 is a sectional view of this same valve 40, taken generally along the line 1--1 of FIG. 29.
FIG. 31 is a longitudinal section view of a delayed action electrical switch.
FIG. 32 is a diagrammatic presentation of the control system for the simultaneous dispensing of multiple beverage ingredients.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Illustrated isometrically in FIG. 1 is an ice making machine comprised of an ice making compartment a compressor compartment 3. Ice/water mixture and syrup conduits 4 are provided for conveying the ice/water mixture and syrup to the remote dispensing unit 5 of FIG. 2. Shown diagrammatically in FIG. 3 is the insulated ice/water mixture storage container 6, the ice forming evaporator 7, syrup storage compartment 3 disposed above the compressor compartment 2, syrup containers 9, and a refrigeration system, better seen in FIG. 4, consisting of a receiver 10 which collects the liquid refrigerant from the condenser 11 and supplied it through refrigerant line 12 to liquid header 13 of the evaporator 7. All refrigerated lines are provided with thermal insulation.
A suitable refrigerant compressor 14 draws refrigerant gas from the suction header 15 of the evaporator 7 through refrigerant suction line 16 and heat exchanger 16a and delivers high pressure refrigerant gas through gas line 17 to condenser 11 producing liquid refrigerant in receiver 10. During the freezing cycle this liquid is circulated through liquid line 12 to heat exchanger 16a and then to liquid header 13 of evaporator 7 through expansion valve 13a.
During the defrost cycle hot gas solenoid valve 17a is opened allowing the hot gas to pass directly to the liquid header 13. A resistance heater 98 is provided in contact with the hot gas line 17 to produce sufficient heat to complete the defrost cycle.
The hot gas valve 17a is actuated by a suitable timer 56 shown in FIG. 28, which senses the lapsed time of the freezing cycle to actuate the opening of the hot gas solenoid operated valve 17a and energizing heater 98, FIGS. 3, 4 and 28, to provide heat to effect the defrost cycle.
During the defrost cycle when the hot gas flows through the evaporator, heat melts the icebond between the ice and the internal surface of the storage tank 6 allowing the formed internal surface of the storage tank 6 allowing the formed ice cubes 18 to float to the surface of the water storage tank 6 thus forming the ice/water mixture. The level of this water is maintained by automatic operation of float valve 21. A circulating ice/water pump and motor 20 is mounted in such a position that the intake of the pump is slightly submerged in the mixture. The mixture is circulated continuously through heat insulated conduits 22 and 23 during periods of activation of the refrigeration compressor 14. Conduit 23 is the return conduit which returns the ice/water mixture to the storage tank through ice restrictor nozzle 24 and water nozzle 25. As the return water is passed through nozzle 25 the velocity is increased sufficiently to cause circulation of the water across the freezing surface of the internal wall of the storage tank, thus removing impurities from the freezing ice cubes and insuring a pure water ice cube supply. The circulating ice/water mixture is circulated through conduit 22 to the three-way diverting valve 26 located in the remote dispensing unit 5 and diagrammatically shown in FIG. 5. This valve in a normal position returns the circulating ice/water mixture into conduit 23 and thus back to the ice-making compartment of the ice making machine. When ice is required at the remote dispensing head 27 the activation of its controls shown in detail in FIGS. 16 and 17 and described below, causes the diverter valve to move from the normally closed position to the delivery position thus feeding the ice/water mixture to the dispensing head conduit 28, FIG. 5. As this mixture moves through this conduit it passes over open drain 29 allowing the water to drain free leaving only ice cubes to be delivered to the dispensing head 27. A chilled water return pump 30 is provided to recover chilled water discharged to drain. Controls for this pump are shown in FIGS. 5, 14 and 28. Also shown in FIGS. 3 and 4 is a soda water compression tank 46, pump and motor 47 and soda delivery tubing 48, all of which delivers soda water through dispensing valve 40a. Suction tubing to pump 47 is provided with strainer 47a. Control for the soda water pump is as shown in FIG. 28 and consists of a pressure operated on-off controller 70. Syrup lines 49, 49a, 49b and 49c, FIG. 5 deliver syrup from the pressurized storage tanks 9, through the dispensing valves 40b, FIG. 5 and similar ones not shown, to dispensing chute 27 through tubing 41b, 41c and 41d, FIG. 15.
Controls associated with the operation of the ice dispensing chute 27 are shown in FIGS. 5, 15, 28 and 32 and consist of a manually operated lever 38a, a manual/electric delayed action switch 31b, electrical conduits 43d, computer control 42b and computer electrical conduit 43a, FIGS. 5 and 15. When electrical delayed action switch 31b is closed for ice delivery the diverter valve operator 35 is activated to divert the ice/water mixture through conduit 28 to dispensing chute 27. The water is drained through tube 29.
The syrup, soda, alcohol beverage and drinking water have associated controls as described below:
Manual operating levers 38, 38a, 38b, 38c and 38d, FIG. 5 are provided for operating delayed action electrical switches 31, 31b and 31d which operate variable flow-rate valves 40, 40a and 40b, which disperse the respective liquids through suitable tubing 41, 41a, 41b, 41c and 41d, shown in FIGS. 14 and 15.
When computer controls 42, 42a, 42b, 42c and 42d are operated through computer electrical conduits 43a, 43b and 43c the desired liquid syrup, soda, alcohol beverage or water is dispensed through their respective tubes 41, 41a, 41b, 41c and 41d located at the dispensing head.
In FIGS. 14 and 15 beverage container 44 is disposed beneath the dispensing head. A conveyor belt 45 is shown as an optional adjunct.
Control circuits for the various elements of the basic invention are shown diagrammatically in FIG. 28 and described below.
An external source of suitable electrical current is conducted through electrical conductors 50 to contactor 51. When control circuit 52 is energized by operating manual on-off switch 53, and low water ice/water storage tank cut-off switch 54 is in the "on" position contact points of the contactor 51 are pulled into contact, the compressor circuit 55 is energized thus operating compressor motor 14 through high pressure cutout switch 57 and low pressure switch 58. The compressor operates continuously under control of the low pressure switch and is protected from damage by automatic operation of the high pressure switch 57. Ice/water circulating pump 20 is energized through electrical conductor 66 and motor over-load circuit breaker 61 when contact points of contractor 51 are contacted. The above control sequence controls the freezing cycle. The ice harvesting cycle is accomplished by operating the hot gas valve 17a and resistance heater 98, by energizing the hot gas valve operator 68 through time clock 69. Electrical energy is fed to circuit 67 during operation of the compressor.
Ice diverter valve operator 35 is supplied with a suitable source of electrical current through electrical conductor 121. In the manual mode when lever 36 is activated mini switch 310 allows current to flow to valve operator 35 which changes the valve 26 to the diverter position sending ice/water mixture to the delivery head. At the same time the chilled water return pump 30 is activated by current flow through extended electrical conductors 121. The drained chilled water is thus returned to the ice making machine.
In the computer mode FIG. 32 a suitable electric signal current is sent from the computer through electrical conductors 43a through time clock 115 to solenoid operator 311. This then activated delayed action switch 31b repeating operation of the manual cycle under control of timer 115.
To effect the delivery of syrups, soda, alcohol beverages and water the associated valves 40, 40a and 40b are actuated by either manual or computer operation. It is noted that the invention includes any number of valves required for each class of function.
When manual operations 38, 38a and 38b are depressed their respective delayed action switches 31, 31a and 31b are closed causing operation of the respective variable flow-rate dispensing valves 40, 40a and 40b. These valves are under automatic control of their preset time clocks. Upon their opening the desired liquid flows through tubing 37, 49, 49a, 49b or 49c to the dispensing head. Delayed action switch 31, FIG. 31, functions as follows:
When manual operator 38 is depressed movement is conveyed through pin 110 to cause blade 111 to make electrical contact with contactor 112 thus energizing holding coil 113 through conductors 114 internal of the body 109 of the switch and conductors 117 external of the switch. Also energized is the clock mechanism 119 of the normally closed timer 115 and the electrical operator 116 of the respective dispensing valve. The switch holding coil 113 maintains operation of the timer clock mechanism 119 until the desired lapsed time for each dispensing valve is obtained and automatically opens electrical switch 120 thus terminating the flow of the delivered product, ice, soda, syrup, etc. Time clock mechanism 119 of timer 115 is provided with a return spring to reset the timer to the starting time after each operation.
Dispensing valve 40 of FIG. 29 consists of a body 99, liquid passageways 100, 101, 102 and 103, a poppet 104, a seat 105, an activating rod 106, bushing elements 107 and 108 and adjusting mechanism 108a to vary the flow-rate. In the computer mode FIGS. 5 and 28, a suitable electric signal current is sent from the computer through electrical conductors 42, 42a or 43b through timeclock 56a, 56b or 56c to solenoid operator 42, 42a, 42b or 42c which opens the dispensing valve to dispense the liquid to the delivery head.
In FIG. 28 soda pump 47 is operated by utilizing a pressure switch 70 mounted on the soda water tubing 48. Upon a drop in pressure the pressure switch activates electrical circuit through electric conductor 71 and maintains operation of the pump until pressure is reestablished in the system.
In addition to the basic invention there is disclosed two embodiments both being shown in FIG. 18. Both embodiments in essence combine the remote dispensing head of the basic invention into the body of the ice making machine thus rendering it suitable for use in a counter serving line.
FIG. 18 is an isometric view of the machine consisting of an ice making compartment 1, a compressor compartment 2, a syrup storage compartment 3, and ice and beverage dispensing compartment 5.
FIG. 19 is a sectional view of the first embodiment of the machine taken generally along line 6--6 of FIG. 18. The construction of this embodiment is similar to the basic machine and incorporates the ice-water storage tank 6, external ice freezing evaporator 7, the complete refrigeration system marked CHILLER, syrup storage compartment 3, soda water tank 46 with its associated elements, the ice/water mixture circulating pump 20 and all tubing, dispensing elements including dispensing head 27, ice diverting valve 35, the ice/water mixture circulating tubing supply 22 and return 23.
The two major modifications of the basic machine to effect a compact unit as envisioned in embodiment one is a redesign of the ice/water tubing 22 and 23 so as to be completely contained within the cabinet of the machine and a change in the configuration of the syrup, soda, alcohol beverage and water tubing 37, 49, 49a, 49b and 49c so that the cooling of these liquids is accomplished by disposing this tubing in contact with the external surface of the ice/water storage tank.
All controls are essentially similar to the controls for the basic unit except that the return chilled water pump is omitted. The return water returns directly by gravity to the ice/water storage tank through conduit 29.
FIG. 22 is a sectional view of the second embodiment of the machine taken generally along line 6--6 of FIG. 18. The construction of this embodiment is an alteration of the basic unit in the following aspects:
The ice/water mixture storage tank 6 is designed as a closed pressure vessel and is provided with a layer of pressurized carbon dioxide gas 79. The ice/water mixture conveyor tube 80 connects the ice consentrating shield 81 to the control valve 82. When the control valve operator 83 is energized carbonized ice/water mixture is fed to the delivery head. This carbonized ice/water mixture is produced by the absorption of carbon dioxide gas into the ice/water mixture. This absorption is assisted by operation of agitator 84.
When ice only is required control lever 78, of FIG. 28 is depressed opening the flow control valve 82 through operator 83 and actuating chilled water return pump 85 to return the water through conduit 86 to the pressurized ice/water storage tank. Check valve 87 prevents back-flow of the ice/water mixture.
The syrup, soda, alcohol beverage and water tubing 37, 49, 49a, 49b and 49c is disposed around and in contact with the external surface of the ice/water storage tank 6 thus accomplishing the cooling of these liquids.
Agitator motor 88 is provided for operation of the agitator 84 and controlled through its electrical conductor 89, FIG. 28, being connected through contractor 51 to operate the agitator continuously during periods of operation of the refrigerant compressor 14.
Mechanism for maintaining carbon dioxide gas 79 for pressure and water level 90, FIGS. 24 and 25 consists of a float switch 91, a three-way valve 92, operator 93 and electrical conductors 94, shown in FIGS. 24, 25 and 28. Connected to the three-way valve are carbon dioxide gas tube 95, water tube 96 and common supply tube 97.
Carbon dioxide gas pressure is maintained constantly through carbon dioxide gas tube 95, to the open side of the three-way diverter valve 92 which maintains a set pressure within the ice/water storage tank. When water is required to maintain the water level the float switch 91 actuates the three-way diverter valve to its diverter side to which the water tubing 96 is connected. Water is then supplied through the common tube 97 to the ice/water storage tank. When the water level is restored, three-way valve 92 is returned to its open position to maintain constant gas pressure.
When ice or ice/water carbonated mixture is required appropriate operating levers at the delivery head are actuated either manually or by computer to effect the proper dispensing. The dispensing is actuated by pressure of the compressed carbon dioxide.
The control system for the simultaneous dispensing of multiple beverage ingredients shown diagrammatically in FIG. 32 operates as follows:
Suitable electrical current is supplied to normally closed time clock 115 through conductors 121. Description and operation of this clock is given under delayed action switch shown in FIG. 31. Upon activation of delayed action switch 31b by manual operation of member 38a or computer operation through conductors 121 to any number of dispensing valve operators. For clarification only, and not to be taken as a restriction of the scope of this control system, these valve operators are designated 42b for dispensing one flavor of syrup through variable flow-rate valve 40b, 42a for dispensing soda water through variable flow-rate valve 40a and 35 for dispensing ice through diverter valve 26. Delayed action switch 31b maintains electric current to all operators for a preset time period. Upon reaching this time period, time clock 115 opens its normally closed circuit through its switch 120 thus allowing each operator to return to its close position closing all dispensing valves. Activator 38b manual and 312 computer, activate through conductor 121a a second flavored syrup dispensing valve and the soda and ice dispensing valves. Conduit 121 b carries operating current to similar operators and dispensing valves.
A manually operated mini switch 310 is activated through manual operator 36 which activates diverter valve 26 to deliver ice to bulk containers such as pitchers, bowls and similar utensils. | An ice making and dispensing machine comprising a chamber for holding a layer of ice particles floating in water held at approximately freezing temperature, a remote dispensing head, an external freezing coil evaporator for freezing water into particulate ice forms, a pump disposed at the surface of the ice-water mixture for moving the mixture to the remote dispensing head, a system of conduits through which the mixture is circulated to the remote dispensing head, a return water pump with appropriate control mechanism and control mechanism with combination manual and electric control variable low-rate dispensing valves and operators, suitable for use with computer circuitry for delivering the ice, soda and syrups through the dispensing head directly into the beverage glass, pitcher or other container. | 5 |
FIELD OF THE INVENTION
[0001] This invention relates to a method and apparatus for utilizing a cryogen including the manipulation, management and control of a cryogen. Cryogen can be utilized in the production of frozen and/or solidified small volumes of desired substances. The small volumes of solidified substances, also called pellets or granules in prior art, are hereinafter referred to as units.
[0002] The invention also relates to a method and apparatus for the manipulation, management, and control of the main body of the cryogen in combination with its internal currents.
BACKGROUND OF THE INVENTION
[0003] The desire for small volumes of substances, individually frozen or solidified has become greater as the technology has improved and the awareness and availability of such a product has increased. This demand includes food type products, bioactive products, chemical products, and in general any liquid, semi-liquid, semisolid or solid that may be desired to be frozen or solidified in small individual units. Small individual units do not demand the thawing of a large amount of product for utilization. Measurability, novelty, convenience, reduced waste, higher quality, ease of use, flowability, handling, minimizing cellular damage, and maximizing product efficacy are also advantages that industry is discovering with small frozen or solidified units. This demand has created a need for a product that has reasonable consistency of size, shape and other physical characteristics.
[0004] In the field of bio-active products, small frozen or solidified units have significant advantages. The freezing process is very fast and results in minimal cellular and structural damage, which provides maintenance of the desired bioactive characteristics.
[0005] The rapid freezing minimizes cellular damage caused by the formation of ice crystals, normally associated with freezing. Bioactive products are often freeze dried for storage. The characteristics of the units make them excellent for freeze drying. The more consistent the size and form of the units, the more favorable they are for a freeze drying process.
[0006] One of the advantages of a small volume of frozen or solidified product is that it can be made to flow like ball bearings (flowability). Thus, the handling of specific amounts of units that may vary with demand is possible. Agglomeration and deformed individual units inhibit the ability to flow as desired.
[0007] Measurement and utilization is also an important feature. If an average weight of the product is known, a specific amount can be utilized without thawing a larger block of product. The thawing of the desired amount of product is faster as a direct result of the relatively large surface area per unit of weight as compared to a frozen block of product. Many characteristics are improved significantly as a result of the rapid freezing or solidification of the small volume of liquids.
[0008] There is prior art in the field of production of frozen units by utilizing a cryogenic liquid. Much of the known art utilizes a particular cryogenic liquid, such as Liquid Nitrogen (LN2).
[0009] The main problem with the prior art is that the small volumes of substance are introduced into the cryogen with relatively little consideration of the manipulation and management of the cryogen itself. This results in the formation of random or poorly formed units. Creation of deformed units is commonly referred to as the “popcorn” effect. The units look like “popcorn” rather than smooth spheres.
[0010] Consistency of size, structure, texture and surface quality as well as control of agglomeration has not been able to be a manageable and controllable feature previously.
[0011] All of these variances result from the inability to control and manage the rapid heat transfer that occurs in the process. This rapid heat transfer results in remarkably violent gasification, which results from introduction of a relatively warm substance into the extremely cold cryogen. Gasification occurs at the interface between the cryogen and the forming units. Violent gasification results in cavitations at the surface of the cryogen resulting from the creation of gas bubbles, which can break the surface of the cryogen. Gas bubbles bursting at the surface of the cryogen can lead to incomplete and non-uniform immersion of the introduced substance into the cryogen. It also causes the units to violently interact. This violent interaction results in significant structural alterations of the units.
[0012] Agglomeration is also often a problem as the rapidly forming units often combine with other units resulting in multiple units combining and solidifying together. This agglomeration affects the flowability of the product as well as affecting other desired qualities
[0013] The relevant prior art is referenced as follows:
[0000] Canadian Patent # 937450:
[0014] This patent describes the deformation that would naturally occur when a small volume of liquid is entered into a body of cryogenic material.
[0000] Canadian Patent # 964921:
[0015] This art describes a small volume of liquid being introduced into an unmanaged and static body of cryogenic liquid.
[0000] Canadian Patent # 1217351 and U.S. Pat. No. 4,655,047:
[0016] This patent describes the improved formation frozen pellets. This patent describes the introduced liquid relative to speed into the body of cryogenic liquid.
[0000] Canadian Patent # 2013094 and U.S. Pat. No. 4,982,577:
[0017] This patent identifies the previous patents' lack of ability to control the exposure of the cryogenic liquid to external heat sources and thereby the subsequent waste of the cryogenic liquid. Although it establishes a good method of handling the liquid for the purposes of cost, it does not identify, mention or claim the benefits of a process of manipulation of the fluid dynamics of the cryogenic liquid to produce the ability to manage the characteristics of the introduced liquid as it solidifies.
[0000] U.S. Pat. No. 4,687,672:
[0018] This patent describes a freezing of large volume of product and its subsequent fracturing and grinding to produce a granular product.
[0000] U.S. Pat. No. 5,126,156:
[0019] This art describes a liquid being introduced into a cryogenic liquid without any reference to manipulation or management of the cryogenic liquid only referring to the removal of the pellets from the liquid after freezing and a screening process to extract only the pellets from the liquid via an auger in a similar fashion to Canadian patent 964921.
[0000] U.S. Pat. No. 6,000,229:
[0020] The art is basically a tub of cryogen with an introduction point of cryogen. In addition an auger for the removal of solidified pellets. There is not any attempt to manage the heat transfer, gasification or other destructive aspects.
[0021] Generally, the prior art in the field focuses on the actual small volume of liquid being introduced and the handling and removal of subsequently frozen product from the liquid cryogen. The prior art typically does not identify or discuss what actually occurs within the body of the cryogen or any methods or apparatus for managing the heat transfer and gasification that directly affects the structure and formation of the pellet being produced.
OBJECTS OF THE INVENTION
[0022] The synergistic effects of the type of management of the present invention include but are not limited to:
a) The dispersion of gas produced by the heat transfer between the thermally different introduced substance and cryogen. b) The dispersion of the heat transfer between the introduced substance and cryogen into the general body of the cryogen. c) Maintaining a physical distance between individual units such that the destructive aspects of physical interactions are minimized.
[0026] This enables the improved management, control and determination of the desired characteristics of the individual units. The characteristics managed are the shape, size, surface texture, deformation, frozen satellites, fines, and agglomeration of the introduced units as they are frozen or solidified.
[0027] Accordingly, several objects and advantages of the present invention include the manipulation and subsequent management of the cryogen utilized in the solidification of a series and/or multiple units of small volumes of a substance introduced into the cryogen. In general practice the cryogen utilized may be Liquid Nitrogen (LN2) or other suitable low temperature liquid.
[0028] Accordingly a primary objective of the present invention is the creation of the synergistic effects resulting from a method and apparatus for the manipulation and management of both the general fluid body (Fluid Body Movement) as well as the internal fluid dynamics (Currents) of the cryogen. These synergistic effects are utilized to control the characteristics of the frozen unit resulting from the introduction of that unit into the body of cryogen, such as Liquid Nitrogen (LN2). The controlled characteristics may include the surface structure, agglomeration, fines, satellites, average size, roundness and the prevention of ice crystallization.
[0029] Another object of the present invention is the physical movement of an introduced unit out of the introduction area of subsequently introduced units as a result of the unit being carried by the flow of the LN2.
[0030] Another object of the present invention is the reduction of physical interaction of forming and formed units with each other thereby avoiding the obvious physical damage that the firmer formed unit would cause to the forming units.
[0031] Another object of the present invention is to facilitate the dispersion of the gasification resulting from the interface between the small introduced unit and the cryogen. This dispersed gasification also assists in the enhancement of currents within the body of the cryogen.
[0032] Another object of the heat and gasification dispersion resulting from operation of the present invention is faster heat transfer from the introduced units into the liquid cryogen, as a result of increased direct contact between the forming unit and the LN2.
[0033] Another object of gas dispersion resulting from operation of the present invention is the minimizing of physical damage done as a result of the violent gasification on the forming unit.
[0034] Another object of the invention is the ability to regulate properties of the units, including these characteristics of the solidified or frozen unit, as the market requires. Properties can range from “popcorn” type products with or without agglomeration to smooth sphere like units that are individual in nature and of primarily similar size and shape.
[0035] An additional object of the invention is the utilization of a recycling system to create the desired flow of the cryogen.
[0036] An additional object of the invention is the utilization of a sloped raceway of varying designs to maintain the flow of the cryogen.
[0037] Another object of the invention is the length of the raceway. The length of the raceway, from the point of introduction of units into the cryogen to the point of units/cryogen separation at the removal mechanism for said units, can be calculated utilizing cryogen flow speed and desired retention time of the units in the cryogen.
[0038] Another object of the invention is the encouragement or discouragement of the internal currents within the body of the cryogen as a result of the recycling process to assist in desired results.
[0039] Additional objects, advantages, and other novel features of the invention will be set forth in part in the description and scientific explanation that follows and in part will become apparent to those skilled in the art upon examination of the following or may discerned from the practice of the invention.
[0040] The prior art does not manipulate, manage or utilize any of the described factors that occur in the cryogen. Previous patents simply introduce a unit into a body of cryogen. The gasification of the LN2 is sufficiently violent that the introduced unit appears to float or levitate on top of the LN2 as a result of the lift power of the gasification. This occurs in spite of the fact that units, in general, are heavier than the LN2. The units at the surface or near the surface are a combination of individual units in all three stages of formation moving violently and randomly. With the violent gasification and the combination of all stages of formation in close proximity it can easily be understood by anyone skilled in the art why the deformation, damage, fragmentation and agglomeration and other characteristics result.
[0041] To achieve the foregoing and other objects and advantages, and in accordance with the purposes of the present invention as described herein, a method and apparatus for producing the desired synergistic effects by manipulation of both the body and internal fluid dynamics of the cryogen utilized in the production of a free flowing frozen or solidified product resulting from the introduction of small volumes of liquid called units into the body of liquid cryogen.
SUMMARY OF INVENTION
[0042] The cryogen, preferably Liquid Nitrogen (LN2), may be drawn from a reservoir or sump at the bottom of the apparatus, by a means to remove said cryogen from the reservoir, such as a recycling system. The recycling system may comprise one or more augers; however, other recycling methods could be utilized. One or more augers may be utilized depending upon desired results. Multiple augers can provide a greater recycling volume as well as increased internal currents. An apparatus which creates a suction effect, or another means to elevate the cryogen from the reservoir may be suitable.
[0043] The recycled LN2 may be moved substantially vertically or upwards from the sump by rotation of an auger. The upward motion of the cryogen may result in a bubbling spring effect when the cryogen begins to transition to horizontal flow. Also, there may be internal currents created within the body of the cryogen that are initially caused by the auger or other recycling system.
[0044] A cryogen auger (as example of pumping methodology) does not have to be completely vertical however the preferred arrangement for lift is an auger that is substantially vertical with a plurality of flutes to be machined at a preferred angle of about 14 degrees from center with a quantity of flute flights of between about 8 and 10 per auger. The flutes preferred spacing is about 2.5 inches apart. The most preferred condition is a substantially vertical auger with a flute angle of 14 degrees from center with a quantity of flute flights of 8 with a spacing between flutes of 2.5 inches. If it is decided to employ an auger angle other than substantially vertical all flute angles and quantity of flutes thereof can be adjusted accordingly to offset the other than substantially vertical condition to allow for similar lifting volume of the cryogen. Large numbers of flutes are possible but can result in added vibration.
[0045] The vertical movement of the cryogen can develop into a fundamentally horizontal movement as it flows away from this transition point. At the transition point, back currents created by a vertical flow may dissipate and before the introduction of the small volume of substances at the introduction point. Once the flow evolves to a fundamentally horizontal flow the currents created by the recycling system disperse any minor gasification that results, resulting in a reasonably smooth surface on the LN2. The initial slope of the raceway at the product/cryogen interface will assist in the management of the speed and depth of the body of LN2 at this juncture with the preferred slope being between about −5 degrees (upward slope) up to about +15 degrees downward slope from the horizontal and the most preferred slope being +5 degrees downward from the horizontal. The subsequent angle of travel along the raceway beyond the interface point is preferred to be about +5 to about +15 degrees downward slope with the most preferred at +7 degrees.
[0046] If the current is too strong for the desired results, a screen or baffles can be utilized in advance of the introduction point of the small volumes of liquid to slow down the internal currents.
[0047] The distance of the exit of the recycling system at the point of transition from vertical to horizontal flow to the introduction point of the small volume of desired substance may be of sufficient distance such that the vertically moving LN2 being recycled converts to horizontal flow, thereby allowing any back eddies created by the vertical flowing liquid changing to a horizontal flow to dissipate and settle and become a non-factor in the current of the cryogen. This distance may be a factor associated with the maximum flow that the recycling system is capable of creating.
[0048] Once the LN2 has achieved a smooth surface and a substantially mono-directional horizontal flow, a desired substance may be introduced into the cryogen via a nozzle either under pressure or by gravity feed. The substance that is introduced may be a stream, or as individual measured droplets in varying degrees of frequency or precision depending upon the desired production outcome required. The height of the nozzle above the introduction zone may be adjustable due to desired characteristics of units. Preferably, the nozzle may be at a height sufficient to limit disruptive current resulting from introduction of the substance. Also, preferably the introduction of the substance will not cause upward spray of the cryogen. The horizontal movement of the LN2 can move the forming unit out of the introduction zone where subsequent units may be continuously introduced into the cryogen.
[0049] The inherent and artificial currents in the LN2 may disperse the gasification created by the introduction of the small volumes of relatively warm substance into the cryogen. Dispersion of this violent gasification at a point away from the introduction zone may enhance the internal currents within cryogen.
[0050] The LN2 can be guided down a sloped raceway. The raceway is constructed in a variety of formats depending upon the desired effect, substance being frozen or solidified, and desired retention time. The raceway may have a stainless steel surface, such as a “mirror” finish applicable in stainless steel polishing in the pharmaceutical industry, or other applications where a smooth finish is utilized. Finishes are typically determined pursuant to the regulatory bodies governing such things for individual industries, such as the FDA. These surface finishes can facilitate cleaning and disinfection of the system when required. In industry, often when there is a change from one product type to another it is essential that substantially the entire previous product be removed and cleaned. This is particularly imperative with bio-active products. In addition the smoother the surface the less the frictional resistance of the surface becomes a parameter in the movement of the cryogen or the individual units.
[0051] The cross section shape of the raceway may be an expanded “U” shape in order to facilitate cleaning and disinfection after use of the equipment. However, the raceway may be enclosed, such as a tube. A “U” shape can minimize corners that would affect the desired currents and flow for the cryogen. The “U” shape may also minimize damming or conglomerations of the units as they proceed down the raceway.
[0052] One embodiment of a raceway may be a spiral raceway. The slope of the raceway can be a function of the desired speed of the body of LN2 that is desired. The length of the spiral can be a function of the desired retention time of the forming and formed units. The longer the raceway or spiral the greater the retention time of the units. The slope of the spiral may also be a function of the desired retention time of the units and the desired speed of the cryogen. A greater the slope of the spiral will increase the rate of flow of the cryogen through the spiral.
[0053] The spiral formation can present additional benefits in that the currents and flow may not develop the opportunity to stabilize as easily as they would in a linear raceway.
[0054] Another embodiment of a raceway may be a series of linear raceways. The linear raceways may have a similar expanded “U” shape, or may be enclosed in a tube form.
[0055] The raceway can be made up of a series of cascading linear raceways, whereby a first linear raceway feeds into a receiving linear raceway running in a substantially different direction. This cascading of the cryogen from a first raceway into the receiving raceway may cause a general mixing of the cryogen and the units. This cascading effect may enhance the internal currents within the cryogen.
[0056] Again, the overall length of the embodiment of the linear raceway can be a function of desired retention time of the introduced units. A particular velocity of the cryogen and a specific length of raceway may result in different durations that the units are in the body of cryogen in advance of being removed by the extraction system.
[0057] The actual number of cascades utilized can be a function of the desired size of the equipment and the enhancement of the currents desired. However, the more cascades that are utilized the more that the internal currents may be enhanced.
[0058] A further embodiment of the present invention may be a linear raceway without any cascading or spiral action. Again, the slope and length of this design may be a function of desired speed and retention time of the units.
[0059] Upon exiting the raceway, the cryogen may travel through a moving screen or wire mesh belt. Preferably, the screen or wire mesh is of a conveyor belt style. The porous screen or mesh can be designed to allow the passage of the cryogen through it while removing the resultant solidified unit. The separation of the unit from the cryogen can be referred to as the removal point.
[0060] The escape of the gasification that has occurred in the cryogen may be via the same exit point as the units on the conveyor belt. Similarly, another advantage may be the utilization of heat transfer from the units to the gas as it escapes with the extraction of the units from the equipment.
[0061] Once passing through the screen or belt, the cryogen may be returned to the sump. There, the returned cryogen can be re-fed into the recycling system, and the process be made continuous.
EXAMPLES
[0062] In order to effectively describe the advantages of the invention, the physics and science of the introduction of a small volume of substance, preferably a liquid, semi-liquid, semisolid or solid, into a body of cryogen, such as LN2, is presented as follows.
Example 1
[0063] For this example water (H 2 O) will be utilized as the sample introduced liquid and Liquid Nitrogen (LN2) will be utilized as the cryogenic liquid.
[0064] Definitions and standards utilized:
[0065] Temperatures will be presented in Kelvin (K), with a conversion to Celsius (C) and Fahrenheit (F).
1. “Freezing Point” of water (H 2 O)=273.15 K 2. 273.15 K=32 degrees F=0 degrees C. 3. 1 degree Celsius=1 degree Kelvin 4. 1 gram (gm) of H 2 O=1 cubic centimeter (cc) of H 2 O 5. 1 cc.=1 cubic centimeter=1 gram of H 2 O 6. calories=1 calorie=the heat required to raise 1 gram of H 2 O 1 degree K 7. “Heat of Fusion” of H 2 O=79.7 cal/gm=79.7 cal/cc 8. “Vaporization Point” of Liquid Nitrogen (LN2)=77.4 K 9. “Heat of Vaporization” of LN2=2.7929 kJ/mol of LN2 10. 1 Mol of LN2=28.0134 gm. 11. 1 cal=4.184 joules 12. LN2=0.807 gm/cc=1.239 cc/gm. 13. 2.79 kJ/mol=23.83 cal/gm=29.526 cal/cc. 14. 1 cal converts 0.642 grn of LN2 to gas or 0.034 cc of LN2 to 5.91 cc of Nitrogen gas. 15. Expansion factor of LN2 liquid to a gas at vaporization temperature=174.6 volume of expansion.
[0081] When 1 gram (1 cc) of H 2 O is introduced into a body of cryogen, being LN2, the heat transfer falls into three main categories:
1. The energy exchange in the lowering of the temperature of the introduced liquid to the point where a ‘Phase Change’ of the introduced H 2 O occurs. 2. The energy exchange associated with the change of phase “Heat of Fusion” 273.15 K or 0 C or 32 F. 3. The energy exchange as the temperature of the units decreases to the desired exiting temperature, below 273.15 K, 0 C or 32 F.
[0085] Above the fusion temperature of water, or pre-solidification:
[0086] It requires 1 cal of energy release from the H 2 O for each degree K of change above the “Fusion” temperature of the introduced water. Therefore it utilizes 0.0411 gm or 0.0339 cc of LN2 for each degree change with a subsequent gas release of 5.9134 cc of Nitrogen gas per degree of change of the H 2 O.
[0087] The physical properties of the introduced small volume of liquid may be very vulnerable during this stage as the unit retains its fluid properties, and hence, most susceptible to deformation, separation and fragmentation as well as agglomeration with previously introduced units and each other. As the crust is formed and solidification is initiated, any physical interaction may cause significant deformation of the forming unit, and possible agglomeration with other forming or formed units.
[0088] The phase change of the introduced liquid:
[0089] It requires 79.7 cal of heat exchange for the “Heat of Fusion” of the introduced product. Therefore this heat exchange vaporizes 79.7×0.0411 gm or 79.7×0.0339 cc of LN2. This result is the release of 471.28 cc of nitrogen gas.
[0090] In a practical application the “Heat of Fusion,” as well as the temperature at which the phase change occurs will vary depending upon the number of solids in the unit and the percentages of other liquids in the units such as lipids (fats), salts, spices, etc.
[0091] The physical properties of the forming unit at this stage can be vulnerable to a more limited extent. In a practical application the solidification may not occur as rapidly as in the H 2 O example. The presence of oils, solids, etc. in the liquid will result in the product being plastic or soft for a greater range of temperature. This results in a product that can be sensitive to physical damage such as deformation, as well as agglomeration with other units until complete solidification occurs.
[0092] Below the fusion temperature, or post-solidification:
[0093] It requires 1 cal of energy release from the H 2 O for each degree of change below the “Fusion” temperature of the introduced water. Therefore, it utilizes 0.0411 gm or 0.0339 cc of LN2 for each degree change with a subsequent gas release of 5.9134 cc of Nitrogen gas per degree of desired change.
[0094] The ability of the unit, when solidified, to transfer heat may increase once it is solidified.
[0095] The physical properties of the frozen or solidified fluid below the fusion temperature are essentially constant, and additional damage or deformation is minimal, if even evident. A benefit to dispersion of gas produced and maintenance of distance between forming units is during the forming, pre-solidification, stage of the units.
[0096] In a model where the water is introduced at 278.15 K or 5 C or 41 F and the removal temperature is 165 K that is −108 C or −162 F, the gas production per cc of introduced H 2 O input is:
Stage 1=5 cal×5.91 cc/cal=29.6 cc of gas released Stage 2=79.7 cal×5.91 cc/cal=471.28 cc of gas released Stage 3=108 cal×5.91 cc/cal=638.62 cc of gas released
[0100] This is a total of 1139.5 cc of gas produced within the body structure of the LN2 per gram or cc of H 2 O introduced. As evident by this example, rapid Nitrogen buildup, or violent gasification, can result from the introduction of the relatively hot units into the LN2. This violent gasification may have a significant affect upon the internal currents and movement of the units within the body of the LN2.
[0101] Escaped gas can be utilized for additional cooling when the units are removed from the equipment on the conveyor screen.
[0102] Once the basic structure of the unit has taken place, the gas release of the individual unit slows down and the unit then sinks into the body of the LN2. Without management, virtually all the damage that would have been done to the physical characteristics would have occurred.
[0103] In a production system there is also a steady state loss of LN2 due to the operation of the equipment. The LN2 will vaporize even without the introduction of external units. This gasification is approximately 5,500 cc or 5.5 liters or 0.2 cubic feet per minute.
[0104] A system producing 200 lbs/hr and operating at an LN2 flow rate of 50% of motor capacity for a single auger LN2 pump and producing a product of approximately 15% to 25% solids will result in the following: The equipment-caused gasification would be approximately 5,500 cc of gas per minute, while the gas production from introduced units would be 1,730,000 cc of gas per min.
Example 2
[0105] A production system processing approximately 90 kilograms or 200 lbs of output per hour will release in excess of 1,730 liters or 61 cubic feet of gas per minute. Over 95% of that gas would be released normally at the interface of the introduced units and the LN2. This substantial gas release at the introduction point can lead to many adverse formation conditions, such as those previously mentioned.
[0106] In a production example, actual units range in size depending upon the introduction nozzles utilized and the particular characteristics of the liquid, semi-liquid, semisolid or solid. The average size may be from about 0.1 cc to 0.5 cc in size, but not limited to these sizes. The size of the unit will not affect the amount of gasification; however, the speed of the heat transfer will increase as the total surface area per total weight of product increases.
[0107] It can also be easily seen by anyone skilled in the art that violent gasification does occur and occurs very quickly at the interface between a forming unit and the LN2. In addition this violent gasification would affect the movement and interaction of units in the body of the cryogen. This type of reaction explains the deformation, size variances, surface characteristics and agglomeration that are noted to occur in the prior art.
BRIEF DESCRIPTION OF THE DRAWINGS
[0108] FIG. 1 is a cutaway view of the apparatus of the present invention.
[0109] FIG. 2 is a cutaway view of the introduction point of the apparatus of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0110] Having summarized various aspects of the present invention, reference will now be made in detail to the description of the invention as illustrated in the drawings and described in the scientific description. While the invention will be described in connection to these drawings and description, there is no attempt to limit the invention to the embodiment or embodiments disclosed herein. On the contrary, the intent is to cover all alternatives, modifications and equivalents included within the spirit and scope of the invention as defined by the appended claims.
[0111] Reference is now made to FIG. 1 showing the apparatus of the present invention. Cryogenic liquid ( 10 ) may be stored in a sump ( 20 ), or reservoir, at the bottom gravitational location of the apparatus. The cryogen may be lifted to the entrance of the raceway ( 24 ) via one or more augers ( 22 ). Alternatively, an impellor-type pump may be used to created vertical flow of cryogen up to the raceway ( 24 ). The cryogen may then transition from vertical movement to horizontal flow, and initiate its travel down a sloped raceway ( 28 ).
[0112] The slope of the raceway can be a factor in the management of cryogen movement in the preferred embodiments for the slope being as follows for the top of the raceway at the product/cryogen interface. The length of the raceway, from the point of introduction of units into the cryogen to the point of units/cryogen separation at the removal mechanism for said units, can be calculated utilizing cryogen flow speed and desired retention time of the units in the cryogen.
[0113] The preferred slope can range from about −5 degrees (upward slope) to about +15 degrees (downward slope) from horizontal. Most preferably the slope is +5 degrees (downward slope from horizontal). The raceway slope can be produced to be adjustable across a desired range. Beyond the product/cryogen interface the raceway slope is preferred at about +5 to about +15 degrees downward slope with the most preferred at +7 degrees.
[0114] The cryogen with units contained therein can pass though a moving screen conveyor belt ( 30 ) that removes the solidified units from the cryogen. The conveyor belt ( 30 ) may be made of a screen, a wire mesh, or any suitable porous material that will filter the solidified or frozen units from the cryogen. The cryogen may then return to the sump ( 20 ) where it is recycled again.
[0115] The pumping capacity of the auger can be in excess of the ability of the cryogen in the sump to keep the entrance full of cryogen. If this operational condition was created, cavitations in the cryogen may occur if the auger is run too fast thereby introducing gas into the auger process. Cavitations in the cryogen may result in the vertical flow not being consistent. Also, an embodiment of the recycling system that consists of two or more augers thereby enables an increased flow without causing the undesirable cavitations and subsequent flow inconsistency.
[0116] The cryogen auger (as example of pumping methodology) does not have to be completely vertical however the preferred arrangement for lift is as follows: The auger can be substantially vertical with a plurality of flutes to be machined at about a 14 degree angle from center with a quantity of flute flights of between about 8 and 10 per auger. The flutes preferred spacing is about 2.5 inches apart. The most preferred condition is a substantially vertical auger with a flute angle of 14 degrees from center with a quantity of flute flights of 8 per auger, with a spacing between flutes of 2.5 inches. If it is decided to employ an auger angle other than substantially vertical all flute angles and quantity of flutes thereof can be adjusted accordingly to offset the other than substantially vertical condition to allow for similar lifting volume of the cryogen. Large numbers of flutes are possible but can result in added vibration.
[0117] Reference is now made to FIG. 2 in which the flow transition point is depicted. The cryogen may be lifted by the auger to enter the raceway ( 24 ). Motion of the auger ( 22 ) may create a circular and vertical direction ( 34 ) of the cryogen. Upon exiting the recycling system at the top of the auger, the direction of the fluid body movement is vertical and circular. The flow may change to a fundamentally horizontal flow. The transition from vertical to horizontal flow may result in the production of back eddies and reverse currents ( 36 ). Back eddies and reverse currents ( 36 ) can result in a spring bubbling-effect up into a body of cryogen then flowing in a horizontal direction.
[0118] These back eddies and reverse currents can be allowed to settle out as the fluid converts to basically horizontal flow ( 38 ) in advance of the introduction point ( 42 ) of the small volumes of a desired substance, such as liquid, semi-liquid, semisolid or solid. Upon introduction into the cryogen, these small volumes may be referred to as units. In another embodiment, a control means ( 40 ) may be introduced at the flow transition point to decrease the intensity of the back eddies and reverse currents. The control means may be a barrier, screen, baffle or dam. In a further embodiment, the apparatus may be adapted to inject a time delay for flow transition. In this embodiment, the auger may rotate with slower speed, there may be a dam before the introduction zone, or a diffusion pool may be added after the introduction zone.
[0119] The length of the raceway can determine the retention time of the units as a function of desired exiting temperature or required time necessary to ensure solidification in the cryogen given a particular speed of motion. In some cases the depth or speed of the cryogen can be adjusted to adjust retention time. In such cases a baffle, screen or a dam is placed in the raceway after the introduction point. A dam obviously increases the depth of the cryogen. A baffle aids in the direction of flow of the cryogen and units. A screen aids in the control of the internal currents in the cryogen.
[0120] The recycling of the cryogen can maintain a constant circular flow as it travels down the raceway back to the sump and up again to the entrance to the raceway ( 24 ).
[0121] The small volumes of substance can be introduced to the cryogen flow via a series of introduction nozzles ( 44 ) that introduce the liquid by streaming, or as individual droplets, either by gravity feed or under pressure. Droplets ( 46 ) can be predefined in volume by a specialized pump or can be determined by the particular surface tension of the liquid and form a droplet that can be released like a drip from a dripping tap.
[0122] The number of nozzles utilized for the introduction of small volumes of liquid, are a function of the engineering of the total unit. Preferably, multiple nozzles may be utilized. The actual number of nozzles utilized is a function of the total volume of liquid that the system can sustain while still maintaining the desired results. In general, the faster the speed of individual units being introduced, the faster the lateral movement of the cryogen required in order to achieve the results desired. In addition to pure cryogen velocity the higher the number of individual units being introduced the greater the surface area of the introduction point required.
[0123] The introduction point ( 42 ) may be positioned downstream from the introduction of the recycled cryogen such that eddies and back currents may have time to settle and a consistent forward flow is achieved. However, the introduction point ( 42 ) may be the same position as the entrance point ( 35 ). The distance from the recycled cryogen entrance ( 35 ) to the introduction point ( 42 ) can be dependent upon the maximum flow capacity desired for the equipment. An example of a desired result at the introduction point is a reasonably smooth surface on the flowing cryogen.
[0124] Preferably, the distance between the nozzles is sufficiently distant such that the droplets or steams will not combine with each other before hitting the surface of the cryogen. Combination of droplets may also be a function of the height of the nozzles above the cryogen surface. Also, the nature of the product being processed can influence the combination of the droplets. The distance between nozzles, height above cryogen surface and nature of product being processed are variable and may be adjusted by user-designation.
[0125] When a droplet is introduced into a horizontally moving body of cryogen, the resulting unit may be moved away from the introduction point ( 42 ). The faster droplets are introduced, the faster the flow of cryogen that is required to move the unit out of the way of the next introduced unit. Preferably, the unit is transported immediately from the introduction zone by the horizontal cryogen flow, thereby reducing the interaction between droplets and unformed units. The speed of the process may be controlled partly by the volume of cryogen recycled, the speed of the recycling of the cryogen, and the slope of the raceway.
[0126] Another management tool is the distance that the droplet will pass through before coming into contact with the LN2. The distance of the droplet height or individual liquid unit height from the body of LN2 can be dependent upon the liquid product to be frozen and could range from very low to very high. The preferred variance is from about 4 inches to about 36 inches above the cryogen. Depending on the product makeup (i.e. solid contents, viscosity and surface tension) and the desired results one wishes to achieve (i.e. consistent shaped pellets of varying degrees or misshapen and agglomerated pellets (i.e. Popcorn shaped) or many other combinations including frozen splatter) the height variance can be substantial. Also, liquid product pumping capacity may require establishment as to not overburden the system with too much liquid to be frozen and hence compromise the results desired or efficiencies of a certain type and size of unit/equipment. Testing of these parameters can be established to correlate to the needs of a particular end user and hence management for said requirements can be forecasted and built in to satisfying the existing and future needs of a user.
[0127] The distance of drop or droplet combined with its size and mass will to an extent demand that a particular depth and speed of LN2 be available in order to inhibit the droplet from hitting the actual bottom of the raceway in advance of the droplet forming its initial crust.
[0128] This methodology results in the gasification created by a particular unit not being added to the gasification of the next unit. In addition, increased flow may prevent the physical interaction of units while they are very susceptible to physical damage, as they are remote from each other.
[0129] The violent gasification results in cavitations. Cavitations are individual bubbles that eventually break the surface of the cryogen. In effect the surface becomes covered with cavitations, which present a jagged surface to which the droplets contact. However, these cavitations can be remarkably destructive to droplets when they are introduced into the flow of cryogen. Maintenance of a smooth cryogen surface at the introduction area can be one of the essential parameters in managing the form and structure of the resultant units. This may be accomplished by maintaining a steady horizontal flow of cryogen.
[0130] As the heat is transferred from the units to the body of cryogen, the currents may move the actual cryogen molecules that are in the process of going through a change of phase or vaporization. Since the actual molecules that are absorbing heat are continually being moved away from the solidifying unit much of the gasification that would normally occur at the interface may be delayed or occur at a point away from the interface.
[0131] The internal currents, still active due to the recycling systems' motion, assist in the dispersion of the gas and heat from the interface. The gasification that occurs within the body of the cryogen can create additional currents that assist in the dispersion of subsequent gasification and heat. The movement of the gas bubbles through the fluid body of the cryogen enhances the existing currents and creates new ones. These currents can aid in the desired effect created by the currents. This can minimize physical damage as a result of the violent gasification. The movement of the gasification and heat away from the interface minimizes the normal encapsulation of the forming unit by the gasification. When a unit is encapsulated in gasification the speed of heat transfer is inhibited, as the gas does not absorb heat as quickly as the liquid cryogen absorbs heat. The result of minimizing encapsulation is that physical contact with the liquid cryogen is maximized, thereby maximizing heat transfer.
[0132] The newly forming units are physically moved out of the way of the next introduction of units as a result of this controlled lateral flow of cryogen, thereby minimizing the physical interaction of forming and formed units with each other. The continued flow down the sloped raceway can maintain this distance between the units. This may assist in controlling the agglomeration that would be expected to occur, as well as the physical interaction and resulting deformation or structural damage to the units that would result.
[0133] Depending upon the product and the management desired in general it is preferred that the cryogen flow be such that product is moved away from subsequent newly introduced product. However for some products minimal or substantial no flow of the cryogen may be advantageous. This is because even without any river type flow of the cryogen there is substantial currents and resulting movement thereof caused within the body of the cryogen as a result of the significant gasification that occurs at the interface between the introduced product and the cryogen. This substantial movement is over and above the great deal of movement that already occurs from the steady state gasification that occurs even without the introduction of the substance to be frozen.
[0134] The preferred rate of cryogen flow is relative to the individual liquid units to be frozen however for each product there can be established of a most preferred rate. This is ultimately accomplished through the testing of each individual liquid type product to be frozen and adjusting the parameter for cryogen flow accordingly to establish a most preferred rate. As well the amount of pumping capacity can vary with the size of each piece of equipment constructed and the number of pumping sources available. For some of what may be considered larger sized pieces of equipment produced (this is of course somewhat subjective to individual industry definition of larger scale) a preferred range for cryogen pumping capacity for example would be about 100 to about 150 liters of cryogen per minute into a river width of about 8 to 12 inches. A most preferred rate would be 120 liters per minute of pumping capacity with a river width of 10 inches. It is important to note that this technology is scaleable (small and large). For comparative purposes for smaller sized equipment than that as cited above the above ranges could be about 50% of those values (once again dependent upon industry definition and need). The cryogen depth can be managed to be within a preferred rate of from about 1 inch to about 3 inches deep by adjusting the cryogen flow rate and/or the horizontal slope of the tray and/or by introducing a downstream flood gate/dam or a narrowing of the raceway that will allow more or less cryogen to flow over it past its point of location depending upon the cryogen depth desired.
[0135] For example, a product of composition such as skim milk dropping simultaneously from approximately 48 nozzles from a height of between 20 and 25 inches into a flowing cryogen source moving along a 10″ trough at a +5 degree angle at the point of interface and then descending at a rate of approximately 2.5 feet per second for a time of approximately 20 seconds (residence time) will produce a consistent size and shape of pellet in a quantity of approximately 325 to 375 pounds per hour.
[0136] In specialized product situations, individual channels can be built in the raceway such that each nozzle utilized at the introduction point directs the droplets to follow a particular channel thereby stopping any horizontal interaction between units that were introduced at the same time.
[0137] When the gasification is removed remotely from the interface and mixed into the general body of the cryogen, the gasification can create additional random mini-currents within the body of the cryogen that assist in the general manipulation of the inherent currents and their subsequent effect as well as encouraging continued movement of the gasification.
[0138] This movement of the gasification away from the interface inhibits the initial floatation or levitation of droplets caused by the violent gasification ( 52 ), thereby minimizing the interaction of floating units that are randomly thrown around and have the possibility of hitting the sides of the raceway and/or each other.
[0139] The form of the raceway can also assist in this management and manipulation. A spiral raceway can continually change the direction of the flow of the cryogen thereby not allowing it to stabilize in a particular direction. A cascading raceway may cause the cryogen to cascade thereby enhancing internal currents and thereby fortifying random currents and flow. A linear raceway may allow the flow to stabilize.
[0140] The solidified units may be removed from the flow of cryogen via a conveyor belt screen with spacing in the screen such that the cryogen flows through the belt while the formed units do not flow through the belt. The belt may take the formed units to the exterior of the equipment where they are stored or utilized as desired. The exit of the cryogen gas due to evaporation or gasification from the equipment can be where the conveyor belt removes the solidified units. Therefore, the units after removal from the cryogen may be in an atmosphere of very cold gas. By adjusting the speed of the belt, the time that the units are exposed to this cold gas can be determined. There may be additional cooling of the units from this exposure to the expelled gas. | A method and apparatus for the manipulation and management process of cryogen such that it controls both the fluid body movement as well as internal currents within the cryogen. Small volumes of a desired substance introduced into this managed cryogen for the production of frozen or solidified pellets or granules are better managed as to shape, size, deformation, frozen satellites, fines and agglomeration and overall desired quality. These benefits result from the dispersion of the gas produced, as well as the heat transferred, resulting from the introduction of the relatively hot substance to the cryogen. The fluid body movement assists in maintaining a distance between the individual solidifying pellets or granules thereby minimizing deformation as a result of physical contact. The output characteristics and desired quality of the pellets can be more effectively controlled and managed, as desired. | 5 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of Invention
[0002] The present invention relates to a steel cord which is used as a reinforcement by being embedded in a tire or the like, and a process for producing the same. More specifically, it relates to an elastomer and steel cord composite which, when used as, for example, a tire reinforcement, can exhibit a satisfactory corrosion resistance and a satisfactory fatigue resistance and which can shorten a curing time in tire component assembling and attain energy saving, and a process for producing the same.
[0003] 2. Description of the Prior Art
[0004] A single layer close-type steel cord obtained by stranding, for example, 3 to 6 filaments (steel filaments) has been so far used as a steel cord for tire reinforcement. FIG. 13 shows a sectional view of a so-called 1×3 steel cord 12 obtained by tightly stranding 3 steel filaments 11 as an example of such close-type steel cord.
[0005] In the single layer steel cord obtained by stranding 3 to 6 steel filaments, a close space 13 is formed in the central portion as shown in FIG. 13 . This space 13 extends in the longitudinal direction of the cord in a straw state.
[0006] The example shown in FIG. 13 is a 1×3 cord. This is the same with 1×4, 1×5 and 1×6 cords, and the space 13 is formed in the central portion.
[0007] However, when the space 13 is formed in the central portion of the cord in the close type, a rubber 14 does not permeate the space 13 in the central portion of the cord as shown in FIG. 14 in forming a composite of the steel cord and the rubber in a tire component assembling step, and the space remains as a hollow portion. And, moisture or the like enters the inside of the cord by external damage of a tire surface, reaches the space 13 in the central portion of the cord as the hollow portion, and permeates the inside of the cord by capillarity in a longitudinal direction. As a result, corrosion proceeds from inside the cord, which might decrease fatigue resistance of the steel cord to shorten the life of the tire.
[0008] Therefore, with respect to a single layer steel cord, for example, open-type cords in which spaces are formed between filaments and rubber permeates the inside of the cord through the spaces, such as a loose open cord obtained by loosely stranding helically formed filaments as shown in JP-A 62-170594 or the like and a flat open cord obtained by loosely stranding filaments formed in a oval helical shape as shown in JP-A 2-133687 or the like have been proposed and used.
[0009] In these open-type steel cords, the spaces inside the cords are filled by permeating the rubber inside the cord in tire component assembling. Accordingly, even when moisture or the like enters owing to external damage in the tire surface, it does not permeate the inside of the cord immediately, solving a problem of corrosion from inside the cord to increase fatigue resistance.
[0010] Nevertheless, the open-type steel cord has, in comparison with the close-type steel cord, a large volume of the space inside the cord, and an amount of air remaining within the cord is large. Accordingly, an amount of air incorporated in a rubber at the time of tire component assembling is increased, and air pushed out from inside the cord in tire component assembling remains as voids (air trapping), in the tire rubber which results in damaging the strength of the tire body. Therefore, for diffusing such air and eliminating voids, it is required to prolong curing time in tire component assembling, which decreases productivity and increases consumption energy.
[0011] Further, a close-type steel cord in which a space in the central portion of a cord is filled with a non-metallic core material to prevent formation of a hollow portion in the central portion of the cord and moisture or the like entered owing to external damage in the tire surface does not permeate the inside of the cord to prevent corrosion and improve fatigue resistance has been also proposed. For example, in a steel cord demonstrated in JP-A 61-138789, a central portion of a cord is filled with an organic core material. Further, in a steel cord demonstrated in JP-B 59-24239, a cured rubber is used as a core material.
[0012] When the space in the central portion of the cord is filled with such non-metallic core material, a problem of corrosion caused by permeating moisture or the like entered owing to external damage in the tire surface can be solved to increase fatigue resistance. However, with respect to the use of the core material such as the organic material or the like, both adhesion with rubber of a tire body and adhesion with steel filaments have to be taken into account, and designing is much restricted. Thus, it is indeed disadvantageous in view of the technique and the cost.
[0013] Further, as the steel cord for tire reinforcement, a 2-layer steel cord obtained by stranding plural filaments (steel filaments) in inner and outer 2 layers has been so far used. As an example of the 2-layer steel cord, FIG. 15 shows a sectional view of a so-called 3+9 steel cord 24 in which 3 steel filaments 21 are stranded to form a core strand 22 and 0.9 steel filaments 23 as outer layer filaments are arranged around the resulting core strand 22 and stranded in a different direction or at a different pitch from that of the core strand 22 .
[0014] In the steel cord obtained by thus stranding the plural steel filaments in 2 layers, as shown in FIG. 15 , a space 25 extending in a straw state in a longitudinal direction of the strand is formed in the central portion of the core strand 22 , and spaces 26 are formed within outer layer steel filaments (between the steel filaments 23 and the core strand 22 ).
[0015] The example shown in FIG. 15 is a 3+9 steel cord, and this is also the case with an (m+n) (m=2 to 4) 2-layer steel cord. Spaces are formed within outer layer steel filaments (between the outer layer steel filaments and a core strand), and air is trapped in these spaces. These spaces are reduced by permeating the rubber coated on the cord surface inside the cord, for example, when curing and pressing the rubber in a tire component assembling step. However, the rubber hardly permeates the space in the central portion of the strand, and a hollow portion longitudinally extending in a straw state remains in the central portion of the steel cord while being embedded in rubber material of a tire. As a result, a fretting abrasion occurs within the steel cord during use of the tire. Further, moisture or the like incorporated into the tire owing to external damage or crack of the tire sometimes reaches the space in the central portion of the strand. The moisture is permeated in a longitudinal direction of the cord by capillarity, and corrosion proceeds within the cord. Consequently, properties (strength and fatigue resistance) of the steel cord in the tire are notably decreased to shorten the product life of the tire.
[0016] Moreover, the influence of the space remaining within the steel cord is not only that, but air remaining in the space is exhausted in tire component assembling to cause air trapping, and this air remains in the rubber to impair the strength of the tire body too. Accordingly, for diffusing such air and eliminating air trapping, a curing time has to be prolonged in tire component assembling, which decreases productivity and increases consumption energy.
[0017] As an improvement of such (m+n) steel cord, there is also a proposal of a steel cord in which outer layer filaments are slightly decreased in number as compared with filaments in tight stranding to provide spaces between the outer layer filaments for facilitating permeation of rubber in tire component assembling. For example, in a steel cord shown in JP-A 7-109685, the number of sheath filaments (outer layer filaments) is set at 7 or 8 relative to 3 core filaments for enabling permeation of rubber in spaces between the sheath filaments and the core filaments. In such a structure, however, it is also difficult to completely fill the spaces within the steel cord with the rubber. In comparison with tight stranding, a life of a tire can slightly be prolonged, however not satisfactory.
[0018] Further, in the 2-layer steel cord obtained by stranding the outer layer filaments around the core strand, stranding is conducted in 2 steps, which involves high production cost. Therefore, a 2-layer steel cord produced at low production cost is required. There is also a proposal of a 2-layer steel cord of 1 stranding process in which plural outer layer filaments (n-filaments) are arranged around plural core filaments (m-filaments) and all of these steel filaments are stranded in a 2-layer structure in the same direction at the same pitch. As an example of such a 2-layer steel cord of 1 stranding process, FIG. 16 shows a sectional view of a so-called 3/9 structure of steel cord 27 in which 9 steel filaments 23 ′ as outer layer filaments are arranged around 3 steel filaments 21 ′ as core filaments and all of these filaments are stranded in a 2-layer structure in the same direction at the same pitch.
[0019] Nevertheless, in the steel cord obtained by stranding the plural core filaments and the plural outer layer filaments at once in the same direction at the same pitch, the stranding direction and the stranding pitch of the core filaments are the same as those of the outer layer filaments. Consequently, drop occurs in the outer layer filaments in the form adhered to the filaments of the core strand obtained by stranding the plural core filaments. Thus, as shown in FIG. 16 , not only space 28 in the central portion of the strand but also spaces 29 inside the outer layer filaments 23 ′ become closed.
[0020] Accordingly, the volumes of the spaces inside the outer layer filaments are decreased in comparison with a 2-layer steel cord of 2 stranding process to decrease an amount of air exhausted in the rubber at the time of tire component assembling. However, the rubber hardly permeates the inside of the cord in tire component assembling. As a result, a fretting abrasion also occurs within the steel cord during use of the tire, and moisture or the like enters the inside of the steel cord owing to external damage in the tire surface, which might decrease fatigue resistance of the tire cord to shorten the life of the tire.
[0021] Moreover, although the volumes are decreased in comparison with the 2-layer steel cord of 2 stranding process, spaces remain. Air remaining in the spaces in the central portion is exhausted in tire component assembling to cause air trapping, and this air remains in the rubber to impair the strength of the tire body. For diffusing such an air and eliminating air trapping, a curing time has to be prolonged in tire component assembling, which decreases a productivity and increases a consumption energy.
[0022] There is further proposal that in the 2-layer steel cord of 1 stranding process a diameter of a core filament is larger than that of an outer layer filament to secure a space between filaments for permeating the rubber into the cord as described in, for example, JP-A 62-125085. However, in this structure, it is also hard to completely fill the spaces inside the cord with the rubber. The life of the tire can slightly be prolonged, however not satisfactory.
[0023] Moreover, there are proposals that a water-absorbent polymer is present in spaces inside a steel cord as described in JP-A 6-49786, that an organic core material is filled in a steel cord as described in JP-A 61-138789 and that a cured rubber is used as a core material of a steel cord as described in JP-B 59-24238. However, in the use of the water-absorbent polymer, the organic material or the like, it is necessary to take both an adhesion with a rubber of a tire body and an adhesion with steel filaments into account. Thus, designing is much restricted. It is indeed disadvantageous in view of the technique and the cost.
[0024] In the ordinary single layer steel cord obtained by stranding 3 to 6 steel filaments, especially in case of the close type, there is a problem that the space in the central portion of the cord remains as a hollow portion in tire component assembling or the like and moisture or the like enters the hollow portion to cause corrosion from inside the cord. In case of the open type, such a problem of corrosion from inside the cord by incorporation of moisture or the like is solved, but the amount of air incorporated in the rubber in tire component assembling or the like is increased. For diffusing this air and eliminating voids, the curing time has to be prolonged, posing a problem of consuming huge energy. Moreover, when the space in the central portion of the close-type cord is filled with a non-metallic core material, adhesion between the core material and the rubber of the tire body and adhesion with steel filaments have to be taken into account, which is disadvantageous in view of the technique and the cost.
[0025] In addition, in the ordinary 2-layer steel cord, the spaces are formed in the central portion of the core strand and inside the outer layer filaments (between the outer layer filaments and the core strand), and a sufficient amount of rubber does not permeate the inside of the cord in tire component assembling. Especially, the rubber does not permeate the space in the central portion of the core strand in tire component assembling or the like, and the space remains as a hollow portion in a straw state. The spaces also remain inside the outer layer filaments. Consequently, a fretting abrasion occurs inside the steel cord during use of the tire. Further, moisture or the like entered into the tire owing to outer damage or crack of the tire during use of the tire reaches the space in the central portion of the core strand, and permeates the inside of the cord in a longitudinal direction. Accordingly, corrosion proceeds from inside, which might notably decrease strength or fatigue resistance of the steel cord in the tire to shorten the life of the tire. Further, when air in the spaces inside the steel cord remains in the rubber owing to air trapping, the strength of the tire body is impaired. For eliminating the air trapping, curing time has to be prolonged in tire component assembling, which poses problems of decreasing productivity and increasing consumption energy.
[0026] Even when the number of outer layer filaments is decreased, for solving these problems, to provide spaces between filaments for facilitating permeation of the rubber, it is difficult to completely fill the space in the central portion of the core strand with the rubber. Further, in the 2-layer steel cord of 1 stranding process for decreasing the production cost, drop occurs in the outer layer filaments, and the spaces between the filaments are in a close state, which causes fretting abrasion and decreases fatigue resistance by incorporation of moisture or the like. For eliminating air trapping, curing time has to be prolonged, which poses problems of decreasing productivity and increasing consumption energy. Still further, in the use of the water-absorbent polymer, the organic material and the like, both the adhesion with the rubber of the tire body and the adhesion with the steel filaments have to be taken into account, which is disadvantageous in view of the technique and the cost.
OBJECTS AND SUMMARY OF THE INVENTION
[0027] The invention is for solving these problems. Objects of the invention are that the life of a single layer or 2-layer steel cord itself which is used as a reinforcement by being embedded in a tire or the like is prolonged by satisfactorily exhibiting corrosion resistance and fatigue resistance, the life of a tire or the like using the same as a reinforcement is prolonged, and curing time in tire component assembling or the like is shortened to attain energy saving and allow production at low cost.
[0028] The invention provides, as a steel cord to solve the foregoing problems, an elastomer and steel cord composite which is a single layer steel cord obtained by stranding 3 to 6 steel filaments, characterized in that an uncured rubber is coated on at least one of the steel filaments and this uncured rubber fills a space in the central portion of the cord.
[0029] And, it provides, as a process for producing the same, a process for producing an elastomer and steel cord composite, characterized by previously coating an uncured rubber on at least one of steel filaments, and simultaneously stranding 3 to 6 steel filaments including the uncured rubber-coated filament to form a single layer elastomer and steel cord composite.
[0030] By this process, 3 to 6 steel filaments including the uncured rubber-coated filament are simultaneously stranded to obtain the single layer elastomer and steel cord composite in which the space in the central portion of the cord is filled with the uncured rubber.
[0031] And, the elastomer and steel cord composite is embedded in the rubber of a tire body in a tire component assembling step as, for example, a tire reinforcement, whereby the uncured rubber is cured to fill the space in the central portion of the cord, which can prevent, for example, a hollow portion from remaining in the central portion of the cord inside the tire and stop corrosion from inside the cord owing to moisture or the like, improve fatigue resistance of the steel cord and prolong the life of a rubber product such as a tire or the like.
[0032] Further, since the space in the central portion of the cord is filled and the amount of air incorporated in the rubber by the cord in tire component assembling is decreased, the curing time in tire component assembling or the like can be minimized to reduce energy loss.
[0033] The uncured rubber is good in adhesion with the rubber of a tire body and adhesion with steel filaments, posing no problem in view of the technique and the cost.
[0034] For completely filling the space in the central portion of the cord, it is advisable to coat the uncured rubber on all of the steel filaments to be stranded.
[0035] It is further advisable that the uncured rubber to be previously coated on the steel filament(s) has the same quality as the tire rubber in view of the adhesion, the cost and the like.
[0036] In this manner, the single layer elastomer and steel cord composite is obtained in which the uncured rubber fills the space in the central portion of the cord. When the elastomer and steel cord composite is used for tire reinforcement or the like, the hollow portion in the central portion of the cord is completely filled, whereby corrosion from inside the cord by incorporation of moisture or the like can be prevented to improve fatigue resistance of the steel cord and the amount of air incorporated in the rubber by the cord in tire component assembling can be decreased to shorten the curing time and suppress wasteful energy consumption.
[0037] Moreover, the invention provides, as a steel cord for solving the foregoing problems, an elastomer and steel cord composite which is a 2-layer steel cord obtained by stranding plural steel filaments as core filaments to form a core strand and stranding plural steel filaments as outer layer filaments around this core strand, characterized in that an uncured rubber is coated on all of the plural steel filaments as core filaments and this uncured rubber fills the spaces inside the cord.
[0038] And, the invention provides, as one process for producing the same, a process for producing an elastomer and steel cord composite, characterized by coating an uncured rubber on all of 2 to 4 steel filaments as core filaments, then simultaneously stranding all of the 2 to 4 steel filaments to form a core strand, and thereafter stranding plural steel filaments as outer layer filaments around the core strand.
[0039] According to this process, the 2 to 4 steel filaments coated with the uncured rubber are stranded to form the core strand, and the plural steel filaments are then stranded around the core strand to obtain the 2-layer elastomer and steel cord composite.
[0040] In this case, the uncured rubber is previously coated on all of the 2 to 4 steel filaments as the core filaments, and these steel filaments are stranded to obtain the core strand in which, when forming an inner space, the uncured rubber fills the very space and the surroundings are coated with the uncured rubber. And, the plural steel filaments as the outer layer filaments are stranded around the core strand so that the spaces inside the outer layer steel filaments (between the outer layer steel filaments and the core strand) are filled with the uncured rubber.
[0041] Thus, the elastomer and steel cord composite is obtained in which all of the inner spaces are filled with the uncured rubber without bleeding the uncured rubber on the surface is obtained. This steel cord is embedded in the rubber of the tire body in tire component assembling as, for example, a tire reinforcement to cure the uncured rubber and completely fill the spaces inside the cord with the rubber. Therefore, no fretting abrasion occurs, and corrosion from inside the cord owing to moisture or the like can be prevented to improve fatigue resistance of the steel cord and prolong the life of a rubber product such as a tire or the like. Further, the spaces inside the cord are filled to decrease the amount of air incorporated into the rubber in tire component assembling, which can allow stable production of a tire and shorten the curing time to reduce energy loss. Still further, the uncured rubber is good in adhesion with the rubber of a tire body and adhesion with steel filaments, and is not problematic in view of the technique and the cost.
[0042] In this process, it is advisable that the uncured rubber to be previously coated on the steel filaments has the same quality as a tire rubber in view of the adhesion, the cost and the like.
[0043] Thus, the 2-layer elastomer and steel cord composite of 2 stranding process is obtained in which the uncured rubber is filled in the space in the central portion and also the spaces inside the outer layer steel filaments (between the outer layer steel filaments and the core strand). When this elastomer and steel cord composite is used in tire reinforcement or the like, the spaces inside the cord are completely filled with the rubber. As a result, no fretting abrasion occurs, and corrosion from inside the cord owing to moisture or the like can be prevented to improve fatigue resistance of the steel cord. An amount of air incorporated into the rubber in tire component assembling is reduced, which can allow stable production of a tire and shorten the curing time to reduce energy loss.
[0044] Moreover, the invention provides, as another process for producing the 2-layer steel cord, the process for producing an elastomer and steel cord composite, characterized by coating an uncured rubber on all of plural steel filaments as core filaments with an uncured rubber, arranging plural steel filaments as outer layer filaments around the plural steel filaments coated with the uncured rubber, and stranding all of the steel filaments in the same direction at the same pitch in a 2-layer structure.
[0045] According to this process, the plural steel filaments as the outer layer filaments are arranged around the plural steel filaments coated with the uncured rubber, and all of the steel filaments are stranded in the same direction at the same pitch to obtain the 2-layer elastomer and steel cord composite.
[0046] In the thus-obtained elastomer and steel cord composite, the uncured rubber is previously coated on all of the plural steel filaments as core filaments, and these filaments are stranded at once along with the plural steel filaments as outer layer filaments, whereby the spaces in the central portion and between the filaments therearound are in close state, and the uncured rubber is filled in the closed spaces. The steel cord is embedded in the rubber of the tire body in tire component assembling as, for example, a tire reinforcement to cure the uncured rubber and completely fill the spaces inside the cord with the rubber. Accordingly, no fretting abrasion occurs, and corrosion from inside the cord owing to moisture or the like can be prevented to improve fatigue resistance of the steel cord and prolong the life of a rubber product such as a tire or the like. Further, since the spaces inside the cord are completely filled with the rubber even in the 2-layer steel cord of 1 stranding process, the amount of air incorporated into the rubber in tire component assembling is decreased, which can allow stable production of a tire and shorten the curing time to reduce energy loss. The uncured rubber is good in adhesion with the rubber of a tire body and adhesion with steel filaments, which is not problematic in view of the technique and the cost.
[0047] In this case as well, it is advisable that the uncured rubber to be previously coated on the steel filaments has the same quality as a tire rubber in view of the adhesion, the cost and the like.
[0048] Thus, the 2-layer elastomer and steel cord composite of 1 stranding process is obtained in which the uncured rubber is filled in the closed spaces in the central portion and between the filaments therearound. When the elastomer and steel cord composite is used for tire reinforcement or the like, the spaces inside the cord are completely filled with the rubber even in the 2-layer steel cord of 1 stranding process, no fretting abrasion occurs, and corrosion from inside the cord owing to moisture or the like can be prevented to improve fatigue resistance of the steel cord. The amount of air incorporated in the rubber in tire component assembling is decreased, which can allow stable production of a tire and shorten the curing time to reduce energy loss.
[0049] Moreover, the invention provides, as a steel cord for solving the foregoing problems, an elastomer and steel cord composite which is a 2-layer steel cord comprising a core layer obtained by stranding 3 or 4 steel filaments and an outer layer formed of plural steel filaments stranded around the core layer, characterized in that an uncured rubber is coated on at least one of the 3 or 4 steel filaments constituting the core layer, and this uncured rubber fills a space in the central portion of the core layer.
[0050] And, the invention provides, as a process for producing the same, a process for producing an elastomer and steel cord composite, characterized by coating an uncured rubber on at least one of 3 or 4 steel filaments as core filaments, simultaneously stranding the 3 or 4 steel filaments including the steel filament(s) coated with the uncured rubber to form a core strand, and then stranding plural steel filaments as outer layer filaments around the core strand.
[0051] According to this process, there is obtained the 2-layer elastomer and steel cord composite with the uncured rubber filled in the space in the central portion of the core layer, the 2-layer elastomer and steel cord composite comprising the core layer and the outer layer and obtained by stranding the 3 or 4 steel filaments including the steel filament(s) coated with the uncured rubber to form the core strand and then stranding the plural steel filaments around the core strand.
[0052] In the thus-obtained elastomer and steel cord composite, the uncured rubber is coated on the part of the 3 to 4 steel filaments constituting the core layer to fill the space in the central portion of the core layer with this uncured rubber. Accordingly, the cord is embedded in the rubber of a tire body in tire component assembling as, for example, a tire reinforcement, whereby the uncured rubber is cured and completely fills the space in the central portion of the core layer. Further, the rubber can be permeated inside the outer layer filaments and between the filaments where the spaces remain. Therefore, corrosion from the central portion of the cord owing to moisture or the like can be prevented to improve fatigue resistance of the steel cord and prolong the life of a rubber product such as a tire or the like. Moreover, the amount of air incorporated in the rubber in tire component assembling is decreased to eliminate air trapping, making it easy to increase the strength of a tire body. The uncured rubber is good in an adhesion with the rubber of a tire body and adhesion with steel filaments, which is not problematic in view of the technique and the cost.
[0053] In the elastomer and steel cord composite, it is advisable to set the diameter and the number of filaments of the core layer and the outer layer such that the average clearance between the steel filaments constituting the outer layer is 2/100 mm or more.
[0054] In the elastomer and steel cord composite, the uncured rubber is coated on only at least one of the 3 or 4 steel filaments constituting the core layer, and the space in the central portion of the core layer is filled with the uncured rubber, while the spaces inside the outer filaments and between the filaments remain. Accordingly, it is required to permeate the rubber into these spaces when combining the rubber of a rubber product (a tire or the like) with the cord by curing and pressing. When the average clearance between the steel filaments constituting the outer layer is 2/100 mm or more, the rubber is easily permeated into the remaining spaces in combining the rubber of a rubber product with the cord to surely achieve the foregoing problem.
[0055] In this case as well, it is advisable that the uncured rubber to be previously coated on the steel filament(s) has the same quality as the tire rubber in view of the adhesion, the cost and the like.
[0056] In this manner, the elastomer and steel cord composite is obtained in which the uncured rubber is coated on at least one of the 3 or 4 steel filaments constituting the core layer and fills the space in the central portion of the core layer. The cord is embedded in the rubber of a tire body in tire component assembling as, for example, a tire reinforcement, whereby the uncured rubber is cured and the space in the central portion of the core layer is completely filled with the rubber. Consequently, corrosion from the central portion of the cord owing to moisture or the like can be prevented to improve fatigue resistance of the steel cord and prolong the life of a tire. Further, the amount of air incorporated in the rubber in tire component assembling is reduced to eliminate air trapping, making it easy to increase the strength of the rubber of a tire body. And, the average clearance between the outer layer filaments is set at 2/100 mm or more, whereby the rubber is permeated inside the outer layer filaments and between the filaments to completely fill the spaces inside the cord with the rubber, making it possible to more improve corrosion resistance and fatigue resistance.
[0057] The above and other objects, features and advantages of the invention will become apparent from the following detailed description which is to be read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0058] FIG. 1 is a schematic view of a step of producing an elastomer and steel cord composite in 1st Example of the invention;
[0059] FIG. 2 is a sectional view of the elastomer and steel cord composite in 1st Example of the invention;
[0060] FIG. 3 is a schematic view of a step of forming a core strand in 2nd Example of the invention;
[0061] FIG. 4 is a schematic view of a step of stranding outer layer filaments around the core strand in 2nd Example of the invention;
[0062] FIG. 5 is a sectional view of the core strand in 2nd Example of the invention;
[0063] FIG. 6 is a sectional view of an elastomer and steel cord composite in 2nd Example of the invention;
[0064] FIG. 7 is a schematic view of a step of producing an elastomer and steel cord composite in 3rd Example of the invention;
[0065] FIG. 8 is a sectional view of an elastomer and steel cord composite in 3rd Example of the invention;
[0066] FIG. 9 is a schematic view of a step of forming a core strand in 4th Example of the invention;
[0067] FIG. 10 is a schematic view of a step of stranding outer layer filaments around the core strand in 4th Example of the invention;
[0068] FIG. 11 is a sectional view of an elastomer and steel cord composite in 4th Example of the invention;
[0069] FIG. 12 is a sectional view of another elastomer and steel cord composite according to 4th Example of the invention;
[0070] FIG. 13 is a unit sectional view of an example of an ordinary 1×3 steel cord;
[0071] FIG. 14 is a sectional view of an ordinary 1×3 steel cord shown in a composite state with the rubber in a tire component assembling step;
[0072] FIG. 15 is a sectional view of an ordinary 2-layer steel cord of 2 stranding process; and
[0073] FIG. 16 is a sectional view of an ordinary 2-layer steel cord of 1 stranding process.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
1st Example
[0074] FIG. 1 shows a step of producing an elastomer and steel cord composite in 1st Example of the invention. In FIG. 1 , 111 is an uncured rubber coating unit, 112 a wire separator, 113 an inlet die, and 114 a buncher (double twist stranding machine). All the units are those known per se.
[0075] This Example is a case of producing a 1×3 elastomer and steel cord composite. Three steel filaments 115 are fed in parallel, and supplied toward an inlet of the buncher (double twist stranding machine) 114 . During the supply, each of the three steel filaments 115 is coated with an uncured rubber through the uncured rubber coating unit 111 . And, the rubber-coated steel filaments are separated into the three with the wire separator 112 , sent to the inlet die 113 , gathered in the inlet die 113 , and supplied to the buncher (double twist stranding machine) 114 where the three filaments are simultaneously stranded at a predetermined pitch.
[0076] In this manner, an elastomer and steel cord composite 116 having a sectional shape shown in FIG. 2 is obtained. In this elastomer and steel cord composite 116 , the uncured rubber 117 is coated on all of the steel filaments 115 before stranding, and these filaments coated with the uncured rubber 117 are stranded to fill a cord central portion 118 with the uncured rubber 117 as shown in FIG. 2 .
[0077] This elastomer and steel cord composite 116 is embedded in a rubber of a tire body in tire component assembling as, for example, a tire reinforcement. In this case, the same material as a tire rubber is used as the uncured rubber 117 previously coated on the steel filaments. And, the uncured rubber 117 is cured in tire component assembling (curing) to completely fill the space in the cord central portion 118 , which can prevent the hollow portion from remaining in the cord central portion inside a tire and prevent corrosion from inside the cord owing to moisture or the like to improve fatigue resistance and prolong the life of a tire. Further, since the space in the cord central portion is filled and the amount of air incorporated into the rubber by the cord in tire component assembling is decreased, it is possible to minimize the curing time in tire component assembling or the like and reduce energy loss.
[0078] Incidentally, the shown example is a case of a 1×3 close cord. The invention can be applied to 1×4, 1×5 and 1×6 close cords too.
[0079] Further, in the shown example, the uncured rubber is previously coated on all of the steel filaments to be stranded. It is also possible to completely fill the space in the central portion of the cord by coating the uncured rubber on a part (at least one) of steel filaments.
2nd Example
[0080] FIG. 3 and FIG. 4 show a process for producing an elastomer and steel cord composite in 2nd Example of the invention. This example is a case of producing a 3+9 structure of elastomer and, steel cord composite. The process comprises a step of forming a core strand (shown in FIG. 3 ) and a step of stranding outer layer filaments around the core strand (shown in FIG. 4 ). In FIG. 3 , 211 is an uncured rubber coating unit, 212 a wire separator, 213 an inlet die and 214 a buncher (double twist stranding machine). In FIG. 4 , 215 is a wire separator, 216 an inlet die and 217 a buncher (double twist stranding machine). All the units are those known per se.
[0081] In the step of forming the core strand as shown in FIG. 3 , 3 steel filaments 218 as core filaments are fed in parallel, and supplied toward an inlet of the buncher (double twist stranding machine) 214 . During the supply, each of the 3 steel filaments 218 is coated with an uncured rubber through the uncured rubber coating unit 211 . And, the rubber-coated steel filaments are separated into the three with the wire separator 212 , sent to the inlet die 213 , gathered in the inlet die 213 , and supplied to the buncher (double twist stranding machine) 214 where the 3 filaments are simultaneously stranded at a predetermined pitch.
[0082] In this manner, the core strand 219 having a sectional shape shown in FIG. 5 is obtained. In this core strand 219 , the uncured rubber 220 is coated on all of the steel filaments 218 before stranding, and these filaments coated with the uncured rubber 220 are stranded to fill a strand central portion 221 with the uncured rubber 220 and coat the surroundings with the uncured rubber 220 as shown in FIG. 5 .
[0083] This core strand 219 is once taken up on a reel. In the subsequent step, as shown in FIG. 4 , the core strand 219 and the 9 steel filaments 222 as outer layer filaments are fed in parallel such that the 9 outer layer filaments are arranged around the core strand 219 , and supplied toward the inlet of the buncher (double twist stranding machine) 217 . The core strand 219 and the 9 outer layer steel filaments 222 were separated with the wire separator 215 , sent to the inlet die 216 , gathered in the inlet die 216 , and supplied to the buncher (double twist stranding machine) 217 to strand the 9 outer layer steel filaments 222 around the core strand 219 .
[0084] In this manner, a 2-layer elastomer and steel cord composite 223 of which the sectional shape is shown in FIG. 6 is obtained. In this elastomer and steel cord composite 223 , the core strand 219 has, as mentioned above, such a structure that the uncured rubber 220 is filled in the strand central portion 221 and the surroundings are coated with the uncured rubber 220 . The 9 outer layer steel filaments 222 are stranded therearound to fill the spaces inside the outer layer steel filaments 222 (between the outer layer steel filaments and the core strand) with the uncured rubber 220 .
[0085] This elastomer and steel cord composite 223 is embedded in the rubber of a tire body in tire component assembling as, for example, a tire reinforcement. In this case, the same material as the tire rubber is used as the uncured rubber 220 to be coated on the steel filaments 218 as core filaments. And, this uncured rubber 220 is cured in tire component assembling (curing), and the spaces inside the cord are completely filled with the rubber. Accordingly, no fretting abrasion occurs, and corrosion from inside the cord owing to moisture or the like can be prevented to improve fatigue resistance of the steel cord and prolong the life of a rubber product such as a tire or the like. Further, since the spaces inside the cord are filled, the amount of air incorporated in the rubber in tire component assembling is decreased, which can allow stable production of a tire and shorten the curing time to reduce energy loss.
[0086] Further, the shown example is a case of the (3+9) structure. Another 2-layer steel cord of 2 stranding process in which a core strand is formed of 2 to 4 steel filaments can also be produced.
3rd Example
[0087] FIG. 7 shows a step of producing an elastomer and steel cord composite in 3rd Example of the invention. This 3rd example is a case of producing a 3/9 structure of elastomer and steel cord composite. In FIG. 7 , 324 is an uncured rubber coating unit, 325 and 326 wire separators, 327 an inlet die and 328 a buncher (double twist stranding machine). All the units are those known per se.
[0088] In this 3rd Example, 3 steel filaments 329 as core filaments and 9 steel filaments 330 as outer layer filaments are simultaneously fed in parallel such that the 3 steel filaments 329 as core filaments are arranged inside and the 9 outer steel filaments 330 as outer layer filaments are arranged therearound, and supplied toward an inlet of the buncher (double twist stranding machine) 328 . During the supply, the uncured rubber is coated on the 3 steel filaments 329 as core filaments with the uncured rubber coating unit 324 , passed through the former separator 325 , and gathered in the latter wire separator 326 . Further, the outer layer steel filaments 330 are directly sent to the latter wire separator 326 . The gathered steel filaments 329 coated with the uncured rubber and the 9 outer layer steel filaments 330 are separated with the latter wire separator 326 , sent to the inlet die 327 , gathered in the inlet die 327 , and supplied to the buncher (double twist stranding machine) 328 where the core filaments and the outer layer filaments are stranded in the same direction at the same pitch.
[0089] In this manner, the 2-layer elastomer and steel cord composite 331 of which the sectional shape is shown in FIG. 8 is obtained. In the elastomer and steel cord composite 331 , the uncured rubber is previously coated on all of the 3 steel filaments 329 as core filaments, and these are stranded along with the 9 steel filaments 330 as outer layer filaments at once, whereby the spaces in the central portion and between the filaments therearound are in a close state, and the uncured rubber 332 is filled in the close spaces.
[0090] This elastomer and steel cord composite 331 is also embedded in a rubber of a tire body in tire component assembling as, for example, a tire reinforcement. In this case, the same material as a tire rubber is used as the uncured rubber 332 to be coated on the steel filaments 329 as core filaments. And, this uncured rubber 332 is cured in tire component assembling (curing), and the spaces inside the cord are completely filled with the rubber. Accordingly, no fretting abrasion occurs, and corrosion from inside the cord owing to moisture or the like can be prevented to improve fatigue resistance of the steel cord and prolong the life of a rubber product such as a tire or the like. Further, since the spaces inside the cord are completely filled with the rubber even in the 2-layer steel cord of 1 stranding process, the amount of air incorporated in the rubber in tire component assembling is decreased, which can allow stable production of a tire and shorten the curing time to reduce, energy loss.
[0091] By the way, the shown example is a case of the 3/9 structure. Another 2-layer steel cord of 1 stranding process in which plural steel filaments are used as core filaments can also be produced.
4th Example
[0092] FIG. 9 and FIG. 10 show a process for producing an elastomer and steel cord composite in 4th Example of the invention. This example is a case of producing a (3+8) structure of elastomer and steel cord composite. The process comprises a step of forming a core strand (shown in FIG. 9 ) and a step of stranding outer layer filaments around the core strand (shown in FIG. 10 ). In FIG. 9 , 401 is an uncured rubber coating unit, 402 a wire separator, 403 an inlet die and 404 a buncher (double twist stranding machine). In FIG. 10 , 405 is a wire separator, 406 an inlet die and 407 a buncher (double twist stranding machine). All the units are those known per se.
[0093] In the step of forming the core strand as shown in FIG. 9 , 3 steel filaments 408 as core filaments are fed in parallel, and supplied toward an inlet of the buncher (double twist stranding machine) 404 . During the supply, at least one of the 3 steel filaments 408 is coated with an uncured rubber through the uncured rubber, coating unit 401 . And, these 3 steel filaments 408 are separated into the three with the wire separator 402 , sent to the inlet die 403 , gathered in the inlet die 403 , and supplied to the buncher (double twist stranding machine) 404 where the 3 filaments are simultaneously stranded at a predetermined pitch. In this manner, the core strand is formed, and once taken up on a reel.
[0094] And, in the subsequent step, as shown in FIG. 10 , the core strand 409 and the 8 steel filaments 410 as outer layer filaments are fed in parallel such that the 8 outer layer filaments are arranged around the core strand 409 , and supplied toward an inlet of the buncher (double twist stranding machine) 407 . The core strand 409 and the 8 outer layer steel filaments 410 are separated with the wire separator 405 , sent to the inlet die 406 , gathered in the inlet die 406 , and supplied to the buncher (double twist stranding machine) 407 to strand the 8 outer layer steel filaments 410 around the core strand 409 .
[0095] In this manner, the 2-layer elastomer and steel cord composite 412 of which the sectional shape is shown in, for example, FIG. 11 is obtained. In this elastomer and steel cord composite 412 , the uncured rubber 413 coated on one of the 3 steel filaments 408 constituting the core strand 409 fills the space in the central portion 414 of the strand.
[0096] This elastomer and steel cord composite 412 is embedded in a rubber of a tire body in tire component assembling as, for example, a tire reinforcement. In this case, the same material as the tire rubber is used as the uncured rubber 413 to be coated on one of the steel filaments 408 as core filaments. And, this uncured rubber 413 is cured in tire component assembling (curing) and the space in the central portion 414 of the strand is completely filled with the rubber. Further, in the spaces inside the outer layer filaments and between the filaments, the rubber is permeated in combining the rubber of a tire or the like with the cord by curing and pressing.
[0097] An elastomer and steel cord composite 412 shown in FIG. 11 is a (3+8) structure using filaments of the same diameter in a core layer and an outer layer. The average clearance t 1 between the steel filaments 410 constituting the outer layer can be set at 2/100 mm or more to provide a good permeability of rubber into the cord when combining the rubber of the rubber product with the cord.
[0098] FIG. 12 is a sectional view of another elastomer and steel cord composite in 4th Example, and shows a (3+9) structure of elastomer and steel cord composite 422 in which the diameter of each steel filament 408 ′ constituting a core filament 421 is larger than the diameter of each steel filament 410 ′ constituting an outer layer.
[0099] This is also produced in the same manner. In a step of forming the core strand, 3 steel filaments 408 ′ as core filaments 421 are fed in parallel, and supplied to a buncher (double twist stranding machine). During the supply, an uncured rubber 413 ′ is coated on one of the 3 steel filaments 408 ′. In a step of stranding the outer layer filaments, the 9 outer layer steel filaments 410 ′ each having a smaller diameter are arranged around the core strand 421 , and supplied to a buncher (double twist stranding machine) where they are stranded.
[0100] In the elastomer and steel cord composite 422 as well, the uncured rubber 413 ′ coated on one of the 3 steel filaments 408 ′ constituting the core strand 421 ′ fills the space in the central portion 423 of the strand. And, the uncured rubber 413 ′ is cured in tire component assembling (curing), and the space in the central portion 423 of the strand is completely filled with the rubber. The rubber permeates the spaces inside the outer layer filaments and between the filaments in combining a rubber of a tire or the like with the cord by curing and pressing.
[0101] Further, the elastomer and steel cord composite 422 shown in FIG. 12 is a 3+9 structure in which the diameter of the core filament is larger than the diameter of the outer layer filament, so that an average clearance t 2 between the steel filaments 410 ′ constituting the outer layer can also be 2/100 mm or more to provide a good permeability of rubber into the cord when combining a rubber of a rubber product with the cord.
[0102] Further, the shown examples indicate the 3+8 or 3+9 structure. A 2-layer steel cord of 2 stranding process in which a core strand is formed of 4 steel filaments can also be produced.
[0103] Further, in the shown examples, the uncured rubber is coated on one of the steel filaments constituting the core strand. The number of filaments on which to coat the uncured rubber may be 2.
[0104] The steel cord for tire reinforcement has been thus far described. The invention can of course be applied to steel cords other than the steel cord for tire reinforcement.
[0105] It should be understood that we intend to cover by the appended claims all modifications falling within the true spirit and scope of our invention. | In order that spaces, including a space in the central portion, inside a steel cord used as a reinforcement by being embedded in a tire or the like are filled with an uncured rubber, the uncured rubber is coated on plural steel core filaments which are then stranded to form a single layer steel cord, the core then being stranded with uncoated outer layer filaments. Consequently, it is possible to exhibit satisfactory corrosion resistance and satisfactory fatigue resistance as a steel cord, shorten a curing time in tire component assembling or the like to attain energy saving and prolong the life of a steel cord itself and the life of a tire or the like using the same as a reinforcement. Further, production can be performed at low cost. | 1 |
CROSS REFERENCE TO RELATED APPLICATION
This is a division of U.S. patent application Ser. No. 06/941,649 filed Dec. 15, 1986 now U.S. Pat. No. 4,848,362.
FIELD OF THE INVENTION
This invention relates to a transducer and apparatus for deep heat therapy in the treatment of musculoskeletal disorders, and more particularly to low leakage radio frequency (RF) contact applicator design with skin and subcutaneous cooling, applicator manufacturing, including applicator testing for quality assurance, and for detection of therapeutic response to achieve treatment control that may use the same transducer simultaneously for effector and sensor functions.
BACKGROUND OF THE INVENTION
That dielectric heating of musculoskeletal tissue is more efficacious and more efficiently accomplished by contact applicators was established by Kantor, U.S. Pat. No. 4,108,147.
Subsequent improvements deal with broad band tuning to accomplish efficient transfer of microwave energy from applicator into tissue over a wide band of frequencies, and cooling using air as well as water, or convective as well as conductive.
A slotted, metallic cover over the radiating aperature of a waveguide applicator was the subject of the Potzl patent, U.S. Pat. No. 3,065,752.
Vaguine in U.S. Pat. No. 4,446,874 made claims concerning coupling and tuning involving discoupling input coupling of the magnetic loop whereby the frequency of operation and input match are adjusted
The design procedures cited in the referenced patents were not viable because these procedures did not provide for compensation and control of evanescent modes in the waveguide applicator. These modes exist principally in the area of the feed that couples microwave energy from the generator via a coaxial cable into the applicator, and on into the patient.
As a result of these modes, the guide wavelength is not equal to the free space wavelength at the frequency of operation, i.e. the TEM mode referred to by Kantor in U.S. Pat. No. 4,108,147 is not necessarily established. The TEM mode cannot exist in a hollow tube waveguide, nevertheless, uniformity of the electric field across the aperture can be improved when the guide wave length is shortened to that of the free space by the use of partial filling with dielectric material parallel to the narrow wall of the guide.
The reduction of the guide wavelength to the free space value is, therefore, a necessary, but not a sufficient condition to accomplish more nearly uniform electric fields across the aperture. Although the guide wavelength may also be shortened by partial filling by dielectric parallel to the broad wall, this does not yield the uniform electric field distribution across the aperture.
The instant invention shows that the length of the dielectric material in the waveguide applicator must also be an appreciable fraction of a wavelength in order to establish the desired guide wavelength and provides for confirmation of the guide wavelength and methods of quality assurance; no methods for confirmation of the guide wavelength or for quality assurance exist in the prior art.
Additionally, this invention establishes the relationship between aperture electric field distribution, guide wavelength, and specific absorption rates at depth sites, none of which is provided for by the prior art.
The instant invention also improves air cooling methods of prior designs which were non-contacting in order to allow egress of air over the patient's skin. The necessary spacing promoted RF leakage as well as tuning variation as the air gap varied with breathing or other motions. RF leakage was not controlled at the point of air ingress and the simple propeller fan mounted within the applicator of the prior design introduces undesirable vibration that modulates the match by alteration of the air gap.
The invention provides for detection of therapeutic response to control dielectric heating during the treatment. Until this invention, no specific individual treatment response has been possible. Prior art was subjective, and at best, the manufacturer provided tabled standards of power and duration for the general population which failed to accomodate for the variations between individuals and were no more than general recommendations. The instant invention makes use of the increase in local blood flow in muscle consequent to local temperature elevation and wave impedance change due to the change in tissue electrical properties, i.e., the instant invention both provokes and detects reactive hyperemia which is the therapeutic response.
The technology of combined microwave heating with sensing has been recognized in other areas. The Furihata patent, U.S. Pat. No. 4,409,993, addressed the need to control dose in an endoscopic device that uses microwave power to heat cancerous tissue to the point of eschar as verified by optical visualization of necrosis. The Converse patent, U.S. Pat. No 4,312,364, and its progeny, the Carr patents, U.S. Pat. Nos. 4,346,716 and 4,557,272, use microwave radiometry to sense heating from an exogenous microwave source.
The instant invention uniquely provides for both heating and sensing of the therapeutic response through the dual use of an antenna. No prior art utilizes the combined effector/sensor action of the instant invention, using the change in complex permittivity of the target tissue due to local vasodilation, nor were the prior methods based on a closely coupled antenna whereby antenna impedance alterations are used to infer changes in the wave impedance of the tissue secondary to the desired reactive hyperemia. Prior technology did not use the critical guide wavelength, design methods, a radome, or surface cooling incorporated as with the instant invention.
SUMMARY OF THE INVENTION
This invention provides new, improved treatment apparatus for dielectric heating as a therapy for musculoskeletal disorders. Implemented are improved methods for contact applicator design which produce more nearly uniform heating in the transverse plane, greater depth of microwave penetration, and apparatus construction which can utilize a dual role of the transducer for both application of power as well as a transducer for sensing the therapeutic response during the treatment without interruption of power delivery.
Quality assurance provides for guide wavelength verification, input match as a function of frequency as well as guide wavelength, and air cooling of the skin which has eliminated spaced applicators and does not promote RF leakage.
A thin radome with a dielectric constant approximately that of subcutaneous fat is employed to interface the applicator to the patient. The radome serves to both prevent fringe field coupling to the patient (leading to excessive heating at the narrow walls of the wave guide where they would otherwise contact the patient), and to provide a low thermal impedance between the air cooling that is applied on its inner surface and the patient's skin that is in contact with its outer surface.
The invention provides for use of the applicator additionally as a sensor for detection of therapeutic response, and use of the sensor response to control the dielectric heating treatment on an individual basis. This is accomplished by measurement and control of the net power absorbed at a level sufficient to produce the desired therapeutic response of increased muscle blood flow. The increased muscle blood flow is a reactive hyperemia in response to temperature elevation. Local temperature elevation in the muscle provokes local vasodilation, opening capillary beds and arterioles. The desired therapeutic response is this reactive hypermia, i.e., increased local blood flow which promotes, for example, resolution of inflammatory infiltrates. The detection of reactive hyperemia also provides an indirect and qualitative measure of muscle temperature in the pattern of the applicator since the local vascular response is triggered at temperatures near 40 degrees centigrade.
An object of this invention is to provide improved treatment apparatus for dielectric heating as a therapy for musculoskeletal disorders.
Another object of this invention is to use increased muscle blood flow which is reactive hyperemia in response to temperature elevation.
Yet another object is to provide a contact applicator design that produces more nearly uniform heating in the transverse plane.
A further object of this invention is to provide an apparatus for treatment which facilitates treatment at greater depths of penetration.
Still another object of this invention is to provide apparatus which acts as both a transducer for application of power, as well as a transducer for sensing the therapeutic response, reactive hyperemia, during the treatment.
Yet another object of this invention is to permit sensing of therapeutic responses without interruption of power delivery.
A further object of this invention is to provide for optimization of the critical parameter of guide wavelength and for the quality assurance for each applicator that includes input match as a function of frequency as well as actual guide wavelength.
Yet another object of this invention is to provide for air cooling of the skin that does not require a spaced applicator and does not promote RF leakage.
It is also an object of this invention to employ a thin radome with a dielectric constant near that of subcutaneous fat to interface the applicator to the patient.
It is a further object of the invention to provide a thin radome to interface the applicator to the patient which prevents fringe field coupling to the patient that normally leads to unwanted heating at the narrow walls of the wave guide where they would otherwise contact the patient.
Yet another object of the invention is to provide a thin radome to interface the applicator to the patient which yields a low thermal impedance between the air cooling that is applied on its inner surface and the skin of the patient that is in contact with its outer surface.
Another object of the invention is to use an applicator as a sensor for detection of therapeutic response, reactive hyperemia, as a means to control the dielectric heating treatment on an individual basis.
Further objects and advantages of this invention will become more apparent in light of the following drawings and description of the preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1, 2 and 3 are the top, side and end orthographic projections, respectively, of one configuration of a preferred embodiment of the invention for applicator/sensor showing a monopole type of electric field feed as the coax to waveguide adapter;
FIGS. 4 and 5 are top and side orthographic projections, respectively, analogous to FIGS. 1 and 2 above, of another embodiment using a magnetic field feed in the form of a shorted loop;
FIGS. 6, 7 and 8 illustrate a high dielectric constant (above critical value), the critical value dielectric constant, and a low dielectric constant, respectively, in diagramatic views of the waveguide showing the expected electric field distribution in the dielectric material and air filled portion of the waveguide;
FIGS. 9 and 10 are a perspective and an end projection, respectively, of one configuration of a preferred embodiment of the invention which is used for manufacturing quality assurance, e.g., to establish the guide wavelength at the critical value;
FIG. 11 is a functional block diagram of the quality assurance apparatus;
FIGS. 12 and 13 are analogous to FIGS. 1 and 2, respectively, with added functional block detail showing the method and apparatus for gas cooling and the means for suppression of RF leakage;
FIG. 14 shows a schematic functional block diagram of the system for the noninvasive detection of the therapeutic response, i.e., reactive hyperemia; and
FIG. 15 is a block diagram showing changes illustrating non-electromagnetic heating modalities.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings, FIGS. 1, 2 and 3 generally depict a typical applicator 18 of length 20, to be substantially equal to one wavelength at the free space phase velocity, an electric field feed 22, encased in a polystyrene cylinder 24, placed at a distance 26 of one quarter of the guide wavelength (previously established to be equal to the free space wavelength at the frequency of operation).
The high dielectric constant (k'=10) and low loss (tan delta=0.002) ceramic (>96%Al1 203) material 28 is placed against the narrow walls of the waveguide 36 and held by mechanical fasteners 30 to the narrow wall. The access to the mechanical fixation on the inside of the applicator is closed by a ceramic plug 32 of substantially the same dielectric properties as material 28, and a thin, e.g. 0.030", radome 34 fabricated from high thermal conductivity material such as Kapton or composite (e.g. G10 with a k'=4 and oriented such that the fiber is cross polarized to the electric field in the waveguide 36).
The input match is tuned by means of the depth of penetration of the cylindrical feed 22 into the waveguide 36. An optional spring loaded inductive post tuning device 21 is placed between the feed 22 and the short circuit 38.
There is a connector 40 for the coax cable transmission line from the generator. Only coarse tuning to a return loss of less than 10 db is effected by use of the tuning device 21 with the radome 34 of the applicator being in contact with simulated fat and muscle phantom prepared according to the methods of prior art. A selected gap is produced by low loss dielectric shims 41.
Provision for tuning the input impedance to the source are also shown in FIGS. 1, 2 and 3. The thickness of the longitudinal dielectric material is selected to produce a critical guide wavelength in a test fixture. Small adjustments in the guide wavelength are made by the insertion of low loss shims 41 between the narrow wall and the dielectric to shorten the guide wavelength.
A second embodiment is shown in FIGS. 4 and 5 which are the top and right side orthographic projection analogous to FIGS. 1 and 2 above. The length 20 of the applicator 18 and the dielectric material 28 is substantially one wavelength at the free space phase velocity. The feed 42 is a magnetic loop shorted at a quarter guide wavelength 44. It is tuned for input impedance by a capacitive shaft 48 and shaft lock 50.
This is preferable to a tuning screw since the shaft lock 50 is a collet and clamp that make more reproducible RF ground than a jamb nut and screw. Another degree of tuning is provided by a stub 52 extending from the post 54. Only coarse tuning to a return loss less than 10 db is effected by the use of the tuning device with simulated fat and muscle against the radome 43.
FIGS. 6, 7 and 8 illustrate the conditions of guide wavelength shorter than the critical value, that for the critical value (the free space value), and guide wavelength longer than the critical value, respectively and represent the electric field distribution 56 in the transverse E plane of guide 58. Use of the design procedure from Kantor and/or Turner will result in the condition shown in FIG. 8 where the electric field peak is outside of the dielectric material and in the air filled region of the guide. The critical condition shown in FIG. 7 is also the one where specific absorption rates (SAR) are highest at distances in the order of 1 to 3 cm below the fat-muscle interface.
The dielectric material 28 is shown in opposition to the narrow wall of the applicator 18 and of equal thickness, but of three values of dielectric constant (high, critical and low) for purposes of illustration.
The electric field distribution 56 in the transverse plane is effected by the guide wavelength as the latter relates to the critical value. When the dielectric material 28 decreases the phase velocity excessively, in comparison to a guide completely filled with air, it may produce a guide wavelength that is too short and the electric field peak exists inside the dielectric as shown in FIG. 6. If the dielectric material 28 does not sufficiently contract the guide wavelength, i.e., the guide wavelength is too long, then the peak occurs in the air filled portion of the guide as shown in FIG. 8. At the critical guide wavelength, the peak is just inside the dielectric at the air interface as shown in FIG. 7.
A third embodiment is shown in FIGS. 9 and 10 which is the apparatus used with the method for assuring manufacturing quality and optimizing applicator operation. This is composed of a waveguide applicator of twice normal length, shorted at both ends to establish a standing wave, and with a movable carriage/probe to sample the electric field distribution via a narrow slot in the center of the guide as shown in FIG. 9. The test fixture guide is of dimensions equal to the applicator and contains the feed and dielectric material as shown in either of the first two preferred embodiments. The electric field feed, for example, and carriage are shown in cross section in FIG. 10. The instrumentation block diagram shown in FIG. 11 illustrates typical results as well as the selected node-to-node distance.
FIG. 9 shows a test fixture 58 of length 60, twice the length of the applicator, with a narrow slot 62, milled into one broad wall. The test fixture 58 is fitted with dielectric of the same thickness and constitutive properties as that used in the applicator.
The waveguide test fixture interior dimensions are also identical to the applicator 18 in the transverse plane. The feed is placed at the shorted proximal end 64 whereas the distal end 66 is shorted to produce an electric standing wave pattern as shown in FIG. 11. The standing wave pattern is measured by a carriage assembly 68 that is scanned along a track 70 on either side of the slot 62.
The carriage assembly 68 holds a probe 72 connected to a variable line stretcher 74 and thence to a crystal diode detector 76. The carriage runs on the two piece track 70 by means of conductive wheels 78 and spring contacts 80. This permits scanning the probe 72, at an adjustable, but minimal penetration, over a large fraction of the length of the test fixture 58.
FIG. 11 shows a signal source 81, a low pass filter 82, with a cut-off 10% above the frequency of operation, and the test fixture 58 shown schematically. The feed energized in the test fixture 58 is also identical to that used in the applicator 18. The RF drive produced by the signal source 81 is square wave modulated at an audio frequency and the detector output is amplified by a tuned amplifier 86.
A typical pattern of electric field standing waves is shown as a function of distance from the shorting plate 64 at the feed end. The first null of the test fixture 58 is 90, the second null is 92, and so on to the last null 98 at the distal shorting plate 66. The distance between null 92, and null 94 is used to estimate half the guide wavelength as it would exist in the applicator 18.
Additional null-to-null values, e.g., 94 and 96, are used to establish that the desired mode has been stabilized, i.e. that the undesired evanescent modes are dampened over the distance or length used for the applicator 18. Lengths substantially less than one wavelength are not sufficient to accomplish the desired mode selection.
Furthermore, the specific absorption rate (SAR) produced at various depths in a bilayer phantom comprised of 1 cm of simulated fat and 10 cm of simulated muscle is improved as the guide wavelength is adjusted for the critical value. This feature is related to, but different from, the uniformity of transverse heating.
For example, at a given thickness of dielectric material 28 shaped as a taper in the feed region and uniform in the load region, the SARs are significantly lower than those produced by the same thickness in full length as shown in Table I.
TABLE I______________________________________GUIDE HALF-WAVELENGTHS T.sub.1 T.sub.2 T.sub.3______________________________________238 mm 77 mW/g 28 mW/g 10 mW/g tapered212 mm 111 mW/g 40 mW/g 14 mW/g 1.062"160 mm 116 mW/g 50 mW/g 16 mW/g +3/16"______________________________________ Notes: All measurements are distance to node #3 minus distance to node #2 in 24" test fixture with electric field feed. Location T1 was 12 mm below the fatmuscle interface. This distance is nearly 1/e depth; thus, the SAR at the interface is ca. 2.7 times higher or 208 mW/g for the longest guide wavelength and 313 mW/g for the near optimal guide wavelength. Since the net power was 50 W in all cases, the efficiency of the applicator is about 4 mW/g/Watt for the longest guide wavelength and about 6 mW/g/Watt for the near optimal case. This is a 50% increase in efficiency. Lastly, the three sites of temperature measurement are 10 mm apart. In th case of the longest guide wavelength, the second site is 36% of the first site and the third site is 35% of the second site. In the case of the nea optimal guide wavelength, the second site is 43% of the first site and th third site is 32% of the second site. This implies that the rate of attenuation with depth of propagation is improved with the near optimal guide wavelength for the bilayer fat/muscle model studied here.
The guide wavelength is adjusted by the use of low loss shims 41 to space the dielectric material 28 away from the wall until the critical guide wavelength is established and the SARs increase. The shims 41 must be thin because although the fields are low near the wall, excessive space prevents stable null-to-null distances.
In FIGS. 12 and 13 the supply ducts 100 and 102 are waveguide below cut-off with attenuation of 60 dB at the frequency of operation. They are connected by flexible hose 106 to a remote fan and source of air at a temperature not higher than 23 degrees C. FIGS. 12 and 13 demonstrate the method and apparatus for air cooling while maintaining contact with the patient and the means for supression of RF leakage by the use of waveguide below cut off for cooling gas supply and return ducts.
The return duct 104 and 110 are also waveguide below cut-off and connected to the low pressure side of the fan by flexible hose 108. The supply ducts 100 and 102 are located on one side to leave room for attachment of the applicator to a positioner. The air flow sensor(s) 112 is used to interrupt the power source via fault control 122 in order to not overheat the skin and superficial subcutaneous tissues in the event of fan failure.
FIG. 14 shows a system for detection of the individual therapeutic response and for treatment control. The method is based on change in the wave impedance of muscle as its blood flow and blood content increase. The change in wave impedance of the muscle is detected by a change in the self impedance of the applicator measured at the terminals of the antenna, or at an integral number of half wavelengths from it, by means of a reflectometer and complex ratiometer. The onset of muscle blood flow is detected by a phase shift in applicator terminal impedance (toward the source) preceded by an increase of the reflection coefficient as the heating takes place.
The power source 114 is selected for frequency stability (1 part/1000 drift) and sufficient power output to produce SARs between 150 and 250 mW/g in bilayer fat/muscle phantoms using the applicator 18. Based on measurements in phantoms and human studies, 30 to 50 watts of CW power are needed. The power source is protected by a three port circulator 116 with a load to protect the power source should the applicator be operated when not matched to or in contact with the patient. The circulator output is connected to the main line of a dual directional coupler 118. The main line continues to a tuner 120, comprised of a stub and a line stretcher then to the applicator/sensor 18. The air flow sensor 112, detects loss of air flow 111 to the applicator/sensor 18, and activates a fault control 122 to interrupt the power source.
The forward and reverse coupled arms are connected to separate power dividers 124 and 126. Attenuation to power levels appropriate for the subsequent instrumentation is accomplished by separate attenuators 128 and 130. When divided, the forward coupled arm enters a bolometer mount, or other power sensor, to measure the forward power via the meter
The other half becomes the reference signal for a complex ratiometer 134. The reverse coupled arm after power division is sampled by the reverse power meter 136 and becomes the test channel for the complex ratiometer 134. The forward and reverse powers, 132 and 136, are subtracted in the differential amplifier 138 and displayed by the dosimeter 140 as the net absorbed energy per unit time. Failure to maintain the selected net absorbed energy per unit time also activates the fault control 122 to interrupt the power source. Net absorbed power is used, therefore, for three purposes: (1) to assist regulation of the net energy per unit time delivered to the patient; (2) to establish a very good match to the patient at the baseline power level; and (3) to detect coupling faults.
Tests have shown that a return loss of 30 dB or better is advantageous. Similarly, the directivity of the reflectometer tuner 120 should be 40 dB or better. The tuner 120 is adjusted to maximize the ratio of forward to reverse power by a procedure well known to those skilled in the art. The complex ratiometer produces two output signals as functions of time as shown in FIG. 15, the magnitude 142 and phase 144 of power wave scattering parameter S 11 .
With reference to FIG. 14, if another form of heating is used, such as ultrasound, the sensor functions may still be implemented. The changes in the instrumentation block diagram are to replace the high power generator 114, with a low power source at the same frequency, and to reduce the value of attenuation in attenuators 128 and 130 to be appropriate for the complex ratiometer 134 input levels. For example, the high power source of 30 to 50 watts would be reduced by 30 dB and the attenuators 128 and 130 would be changed for 30 dB less attenuation in order to set proper signal levels at the complex ratiometer 134.
With reference to the complex ratiometer outputs shown in FIG. 15, the time course of the complex scattering parameter discloses biophysical events in the muscle by virtue of the effect of changes in the wave impedance due to the blood flow and blood content of that tissue. Since the applicator/sensor 18 is closely coupled to the tissue being heated, the self impedance of the applicator is effected by the change in wave impedance in the tissue as the blood flow and blood content increase.
The change in applicator/sensor self impedance is monitored at the antenna's terminals, or at an integral number of half wavelengths toward the generator, by changes in the complex reflection coefficient as normalized by the forward wave.
Furthermore, in reference to the complex ratiometer outputs 142 and 144 shown in FIGS. 14 and 15, the observed changes in the magnitude of S 11 recorded over time in as 142 are a gradual increase in the magnitude, without a significant change in phase, as the tissues heat. These events are illustrated at time reference 146 when the specified net energy per unit time is first established. The latency, time at 148 minus time at 146, to onset of phase shift 144 is shown in rectangular coordinates. The end of power application is shown at 150 and start of the range of motion/strength exercises during the cool-down period at 152 is also shown in FIG. 15.
In terms of a polar display of S 11 the magnitude increases substantially along a radius of constant phase. As the change of magnitude approaches a plateau, a latency of several minutes, shown at 146 and 148, is required before the phase rotates toward the generator on the Smith chart.
This phase rotation often takes place coincident with a reduction in the subjective feeling of deep heat. This sequence of events takes typically 10 to 20 minutes at the stated reference SARs. The latency, time at 148 minus time at 146, corresponds to the time necessary to elevate muscle temperatures to the point where local vasodilation takes place. At that point, the phase rotation takes place with characteristically small additional changes in magnitude.
Whereas certain specific embodiments of the improved apparatus for deep heat treatment of musculoskeletal disorders have been disclosed in the foregoing description, it will be understood that various modifications within the scope of the invention may occur to those skilled in the art.
Therefore, it is intended that adaptations and modifications should be comprehended within the meaning and range of functional equivalents of the preferred embodiments. For example, changes in material and dimensions that are subsumed in the teaching of the instant patent may be used in place.
Likewise the display options for detection of the therapeutic response may use any of the equivalent parameters of impedance, reflection coefficient, scattering parameters S 11 , or admittance displayed in rectangular or equivalent polar co-ordinates or coordinate transformations such as the Smith chart or Carter chart.
Similarly broader bandwidth (10% to 20%) impedance matching may be employed to augment the narrow band reactive tuner as is well known to those skilled in the art. | Therapeutic deep heating of musculoskeletal tissues is accomplished with an improved transducer that serves simultaneously to couple the power from the generator into the patient and to sense the therapeutic response for treatment control including a method of manufacture and testing of contact applicators for dielectric heating of musculoskeletal tissue. The applicator has a rectangular waveguide in which dielectric material is placed to reduce the guide wave length to the free space value at the frequency of operation. The noninvasive detection of therapeutic response in muscle tissue to dielectric heating is then used to control the treatment. Both heating and sensing are accomplished by one transducer and one apparatus if dielectric heating is employed. If other forms of heating are used, such as ultrasound, the sensor still occurs but the apparatus must be modified, the modifications including replacement of the high power electromagnetic source with a low power source version. | 0 |
FIELD OF THE INVENTION
The invention relates to use of enzymes for sustainable wash water treatment and maintenance. In particular, the invention relates to use of enzymes for effectively removing soils from wash water sources, such as the wash liquor or wash water solutions in a variety of cleaning applications, namely sumps. The invention cleans wash water sources and prevents the re-deposition of soils on treated surfaces. The methods according to the invention provide further benefits of improving the efficacy of detergents in treating surfaces, such as ware and wash equipment, as a result of cleaning wash water sources. Methods of wash water maintenance according to the invention provide sustainable practices by improving water quality and minimizing water and energy consumption in wash systems.
BACKGROUND OF THE INVENTION
Enzymes have been employed in cleaning compositions since early in the 20 th century. It was not until the mid 1960's when enzymes were commercially available with both the pH stability and soil reactivity for detergent applications. Enzymes are known as effective chemicals for use with detergents and other cleaning agents to break down soils. Enzymes break down soils making them more soluble and enabling surfactants to remove them from a surface and provided enhanced cleaning of a substrate.
Enzymes can provide desirable activity for removal of protein-based, carbohydrate-based, or triglyceride-based stains from substrates. As a result, enzymes have been used for various cleaning applications in order to digest or degrade soils such as grease, oils (e.g., vegetable oils or animal fat), protein, carbohydrate, or the like. For example, enzymes may be added as a component of a composition for laundry, textiles, ware washing, cleaning-in-place, drains, floors, carpets, medical or dental instruments, meat cutting tools, hard surfaces, personal care, or the like. However, enzyme cleaning products only focused on ability to remove soils from substrates. Although enzyme products have evolved from simple powders containing alkaline protease to more complex granular compositions containing multiple enzymes and still further to liquid compositions containing enzymes, there remains a need for alternative cleaning applications for enzymes.
Accordingly, it is an objective of the invention to develop methods for use of enzymes to remove soils from wash water sources.
A further object of the invention is to develop methods for improving sustainability of cleaning processes, such as decreasing the amounts of water and energy required for such processes through the cleaning of wash water sources with enzymes.
BRIEF SUMMARY OF THE INVENTION
A method for washing a wash water source is provided according to the invention. The method includes steps of generating an enzyme composition and cleaning a wash water source. A method for removing soils and improving quality of waste water from a wash water source is also provided according to the invention. The method includes generating an enzyme composition and washing a wash water source with an aqueous use solution, wherein the washing removes soils from the wash water source to improve the quality of a waste water source generated from said wash water source.
The enzyme composition according to embodiments of the invention forms an aqueous use solution that can be obtained by contacting the enzyme composition with water, and allowing the formed aqueous use solution to drain from the enzyme composition. According to an alternative embodiment, the aqueous use solution can be obtained by contacting a detergent composition and an enzyme composition or a combination detergent/enzyme composition with water, and allowing the formed aqueous use solution to drain from the detergent and enzyme compositions. The detergent composition and enzyme composition may be formulated in combination or separately according to use in the methods of the invention. The active level of the aqueous use solution is adjusted to a desired level through control of variables such as the amount of active enzymes in the detergent and enzyme compositions, length of time and the temperature at which the water contacts the detergent and enzyme compositions.
The particular enzyme or combination of enzymes for use in the methods of the invention depends upon the conditions of final utility, including the physical product form, use pH, use temperature, and soil types to be cleaned with a wash water source. The enzyme or combination of enzymes are selected to provide optimum activity and stability for a given set of utility conditions as one skilled in the art will recognize based on the disclosure of the claimed invention.
These and other methods described herein according to the invention provide the benefit of sustainably treating wash water sources. For example, methods of cleaning wash water sources with enzymes decrease the total amount of water needed for cleaning applications. Such water reduction is a result of significantly decreasing the frequency at which wash water needs to be replaced with a clean wash water source. This presents a significant advantage over prior art cleaning applications, where wash water sources need to be frequently replaced in order to minimize the re-depositing of soils from wash water sources that are recirculated in a cleaning system. Traditionally, without the frequent replacement of soiled wash water sources with clean wash water such soils will re-deposit in a cleaning system. This need is significantly minimized, if not obviated, according to the advantages provided by the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The embodiments of this invention are not limited to particular methods of cleaning wash water sources, removing soils from wash water and improving the quality of wash water, which can vary and are understood by skilled artisans. It is further to be understood that all terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting in any manner or scope. For example, as used in this specification and the appended claims, the singular forms “a,” “an” and “the” can include plural referents unless the content clearly indicates otherwise. Further, all units, prefixes, and symbols may be denoted in its SI accepted form. Numeric ranges recited within the specification are inclusive of the numbers defining the range and include each integer within the defined range.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which embodiments of the invention pertain. Many methods and materials similar, modified, or equivalent to those described herein can be used in the practice of the embodiments of the present invention without undue experimentation, the preferred materials and methods are described herein. In describing and claiming the embodiments of the present invention, the following terminology will be used in accordance with the definitions set out below.
The term “about,” as used herein, refers to variation in the numerical quantity that can occur, for example, through typical measuring and liquid handling procedures used for making concentrates or use solutions in the real world; through inadvertent error in these procedures; through differences in the manufacture, source, or purity of the ingredients used to make the compositions or carry out the methods; and the like. The term “about” also encompasses amounts that differ due to different equilibrium conditions for a composition resulting from a particular initial mixture. Whether or not modified by the term “about”, the claims include equivalents to the quantities refers to variation in the numerical quantity that can occur.
The term “wash water,” “wash water source,” “wash liquor,” “wash water solution,” and the like, as used herein, refer to water sources that have been contaminated with soils from a cleaning application and are used to circulate or re-circulate water containing detergents or other cleaning agents used in cleaning applications to treat various surfaces. According to certain regulated cleaning applications, wash water is required to be regularly discarded and replaced with clean water for use as wash water in cleaning applications. For example, certain regulations require wash water to be replaced at least every four hours to maintain sufficiently clean water sources for cleaning applications. Wash water, according to the invention, is not limited according to the source of water. Exemplary water sources suitable for use as a wash water source include, but are not limited to, water from a municipal water source, or private water system, e.g., a public water supply or a well, or any water source containing some hardness ions. Accordingly, wash water is understood to only exclude deionized water sources which are known to deactivate enzymes.
The term “weight percent,” “wt-%,” “percent by weight,” “% by weight,” and variations thereof, as used herein, refer to the concentration of a substance as the weight of that substance divided by the total weight of the composition and multiplied by 100. It is understood that, as used here, “percent,” “%,” and the like are intended to be synonymous with “weight percent,” “wt-%,” etc.
According to an embodiment of the invention, wash water solutions are cleaned by enzymes in order to provide sustainable water maintenance methods and enhance cleaning of treated surfaces through improvements in detergency. Enzymes are used according to the methods of the invention to effectively remove soils from wash water in order to clean wash water and provide enhanced longevity of use of such wash water for cleaning applications as well as enhance the quality of discarded waste water sources. In addition, the methods of using enzymes to clean a wash water source further promote cleaning of various surfaces, including ware, sump and the wash equipment surfaces itself, such as the interior of a washing machine by improving the detergency of the cleaning application.
Methods of Use
The methods of using enzyme compositions according to the invention include cleaning a wash water solution. The methods of use of enzyme compositions according to the invention further include methods of removing soils and improving the quality of waste water sources from wash water in various cleaning applications. According to embodiments of the invention, enzymes reduce or eliminate soil content in wash water sources. Preferred embodiments of the invention provide complete elimination of soil levels in a wash water source with the use of enzymes according to the methods of the invention. Additional benefits of providing enhanced cleaning and sustainability are also described according to the invention.
According to a further embodiment of the invention, methods of cleaning wash water sources further result in the prevention of and removal of soil buildup on the interior surfaces of cleaning equipment and treated surfaces contained therein. Such surfaces may be either removable or permanent surfaces of cleaning equipment.
According to the methods of the invention, enzyme compositions may be introduced, for example, manually or by a dispenser, pump, pump and control system or other means into a wash water source. According to the invention, an aqueous use solution for cleaning a wash water source is generated by adding an enzyme composition to a water source. In numerous cleaning applications the water source will be the wash water source. According to an alternative embodiment of the invention, an aqueous use solution may be generated by adding an enzyme composition, detergent composition or a combined enzyme and detergent composition to a water source, such as the wash water source. According to the invention, the detergent composition and enzyme composition may be formulated either in combination or separately.
According to the invention, the active level of enzyme in the aqueous use solution may be modified according to the precise requirements of the cleaning application. For example, the amount of enzyme formulated into the enzyme composition may vary. Alternatively, as one skilled in the art will appreciate, the active level of the aqueous use solution may be adjusted to a desired level through control of the wash time, water temperature at which the water source contacts the enzyme composition or the enzyme and detergent composition in order to form the aqueous use solution and the detergent selection and concentration. According to a preferred embodiment, an aqueous use solution comprises between approximately 0.1 ppm and 100 ppm enzyme, preferably between about 0.5 ppm and about 50 ppm, and more preferably between approximately 1 ppm and 20 ppm enzyme.
According to further embodiments of the invention, the amount of enzyme needed to clean and remove soils from a particular wash water source varies according to the type of cleaning application and the soils encountered in such applications. According to various embodiments of the invention, levels of enzymes in an aqueous use solution are effective at or below approximately 0.1 ppm, 0.5 ppm or 1 ppm. According to alternative embodiments, use levels of enzymes may be as great as 100 ppm, with most applications utilizing enzymes in aqueous use solutions between approximately 1-10 ppm.
One skilled in the art will appreciate that the methods according to the invention can be used for a variety of cleaning applications, such as ware washing, laundry washing, and other applications. For example, ware washing applications according to the invention may include ware wash sump cleaning, ware wash machine cleaning (automated and/or manual) and holding tank cleaning. Laundry applications according to the invention may include the cleaning of laundry sumps. Additional cleaning applications may include cleaning of waste water in vehicle care applications, such as the cleaning of wash water solutions contacting oils, grease and other soils. Still further, cleaning applications in health care may further benefit from the methods according to the invention, including for example, cleaning waste water or rinse water sources for cleaning applications used in health care facilities.
The methods according to the invention may further be used in any wash water treatment application wherein water sustainability is desired. According to the embodiments of the invention, cleaning a wash water source by removing soils from the water increases the time frame in which water changes are required, such that less water is used due to decreased need to replace wash water. The use of enzymes to clean the wash water source improves the wash water quality and permits prolonged use of the wash water source. Such prolonged use decreases the volume of clean water used in a cleaning application and decreases the amount of energy used to heat wash water sources for various cleaning applications. As an additional benefit, the quality of waste water disposed of from a cleaning application is improved, providing environmental benefits.
Enzyme Compositions
The enzyme compositions for use in the methods according to the invention provide enzymes for washing, removing soils and improving the quality of waste water from a wash water source. The purpose of the enzyme composition is to break down adherent soils, such as starch or proteinaceous materials, typically found in soiled surfaces and removed by a detergent composition into a wash water source. The enzyme compositions decrease and/or eliminate the soils in wash water sources once the soils become readily dispersed into the wash water by a detergent or other cleaning agent.
Exemplary types of enzymes which can be incorporated into the enzyme composition according to the invention include amylase, protease, lipase, cellulase, cutinase, gluconase, peroxidase and/or mixtures thereof. An enzyme composition according to the invention may employ more than one enzyme, from any suitable origin, such as vegetable, animal, bacterial, fungal or yeast origin. According to an embodiment of the invention, the enzyme composition includes at least two different enzymes. According to a further embodiment of the invention, mixtures of the same class of enzymes are incorporated into an enzyme composition, such as a mixture of various amylase enzymes.
Examples of commercially-available amylase enzymes are available under the following trade names: Purastar, Purastar ST, HP AmL, Maxamyl, Duramyl, Termamyl and Stainzyme. Examples of commercially-available protease enzymes are available under the following trade names: Purafect, Purafect L, Purafect Ox, Everlase, Liquanase, Savinase, Esperase, Prime L, Prosperase and Blap. Lipases are commercially available, for example, under the trade name Lipex and Lipolase. Cellulase enzymes are commercially-available, for example, under the trade name Celluzyme.
According to the invention, the enzyme composition may be varied based on the particular cleaning application and the types of soils in need of cleaning. For example, the temperature of a particular cleaning application will impact the enzymes selected for an enzyme composition according to the invention. Ware wash applications, for example, clean substrates at temperatures in excess of approximately 105° F. and enzymes such as amylases and proteases are desirable due to their ability to retain activity at such elevated temperatures.
In addition, as one skilled in the art shall ascertain, enzymes are designed to work with specific types of soils. For example, according to an embodiment of the invention, ware wash applications may use an amylase enzyme as it is effective at the high temperatures of the ware wash machines and is effective in reducing starchy, carbohydrate-based soils. Although not limiting the present invention, it is believed that amylase can be advantageous for cleaning soils containing starch. Amylase enzymes can be obtained from any suitable source, such as bacterial strains, barley malt, certain animal glandular tissues and any others known to the art. Amylase enzymes may include those which are referred to as alpha-amylases, beta-amylases, iso-amylases, pullulanases, maltogenic amylases, amyloglucosidases, and glucoamylases, as well as other amylases enzymes not particularly identified herein. These also include endo- and exo-active amylases.
According to an alternative embodiment, methods of cleaning wash water sources in a laundry machine may use a combination of amylase and protease enzymes in order to most effectively prevent starch, proteins and oils from hindering detergent performance. Although not limiting the present invention, it is believed that protease can be advantageous for cleaning soils containing protein, such as blood, cutaneous scales, mucus, grass, food (e.g., egg, milk, spinach, meat residue, tomato sauce), or the like. Protease enzymes are capable of cleaving macromolecular protein links of amino acid residues and convert substrates into small fragments that are readily dissolved or dispersed into a wash water source. Proteases are often referred to as detersive enzymes due to the ability to break soils through the chemical reaction known as hydrolysis. Protease enzymes can be obtained, for example, from Bacillus subtilis, Bacillus licheniformis and Streptomyces griseus . Protease enzymes are also commercially available as serine endoproteases.
According to an additional embodiment of the invention, a cellulose or lipase enzyme may be incorporated into an enzyme composition. Although not limiting the present invention, it is believed that cellulase can be advantageous for cleaning soils containing cellulose or containing cellulose fibers that serve as attachment points for other soil. Although not limiting to the present invention, it is believed that lipase enzymes can be advantageous for cleaning soils containing fat, oil, or wax, such as animal or vegetable fat, oil, or wax (e.g., salad dressing, butter, lard, chocolate, lipstick). Both cellulase and lipase enzymes can be derived from a plant, an animal, or a microorganism, such as a fungus or a bacterium. A cellulase or lipase enzyme can be purified or a component of an extract, and either wild type or variant (either chemical or recombinant).
Additional enzymes suitable for certain embodiments of the invention include cutinase, peroxidase, gluconase, and the like. Suitable enzymes are described for example in WO 8809367 (cutinase), WO 89099813 and WO 8909813 (peroxidases), and WO 9307263 and WO 9307260 (gluconase). Known peroxidase enzymes include horseradish peroxidase, ligninase, and haloperoxidases such as chloro- or bromo-peroxidase. Peroxidase enzymes can be used in combination with oxygen sources, e.g., percarbonate, perborate, hydrogen peroxide, and the like. Each of these enzymes may be derived from a plant, an animal, or a microorganism and can be purified or a component of an extract, and either wild type or variant (either chemical or recombinant).
The enzyme compositions according to the invention may be an independent entity and/or may be formulated in combination with a detergent composition. According to an embodiment of the invention, an enzyme composition may be formulated into a detergent composition in either liquid or solid formulations. In addition, enzyme compositions may be formulated into various delayed or controlled release formulations. For example, a solid molded detergent composition may be prepared without the addition of heat. As a skilled artisan will appreciate, enzymes tend to become denatured by the application of heat and therefore use of enzymes within detergent compositions require methods of forming a detergent compositions that does not rely upon heat as a step in the formation process, such as solidification.
The enzyme composition may further be obtained commercially in a solid (i.e., puck, powder, etc.) or liquid formulation. Commercially-available enzymes are generally combined with stabilizers, buffers, cofactors and inert vehicles. The actual active enzyme content depends upon the method of manufacture, which is well known to a skilled artisan and such methods of manufacture are not critical to the present invention.
Additional description of enzyme compositions suitable for use according to the invention is disclosed for example in U.S. Pat. Nos. 7,670,549, 7,723,281, 7,670,549, 7,553,806, 7,491,362, 6,638,902, 6,624,132, 6,197,739 and U.S. patent application Ser. No. 12/642,091 filed Dec. 18, 2009 titled “Multiple Enzyme Cleaner for Surgical Instruments and Endoscopes,” Ser. No. 11/279,654, filed Apr. 13, 2006 titled “Stable Solid Compositions of Spores, Bacteria, Fungi and/or Enzyme,” Ser. No. 10/654,333, filed Sep. 2, 2003 titled “Stable Solid Enzyme Compositions and Methods Employing Them,” the contents of which are incorporated by reference in its entirety. In addition, the reference “Industrial Enzymes”, Scott, D., in Kirk-Othmer Encyclopedia of Chemical Technology, 3rd Edition, (editors Grayson, M. and EcKroth, D.) Vol. 9, pp. 173-224, John Wiley & Sons, New York, 1980 is incorporated herein in its entirety.
Enzyme Stabilizers
The enzyme compositions for use in the methods of the present invention may further include enzyme stabilizers. One skilled in the art will ascertain suitable enzyme stabilizers and/or stabilizing systems for enzyme compositions suitable for use according to the invention, such as those described, for example, in U.S. Pat. Nos. 7,569,532 and 6,638,902, which are incorporated herein in their entirety. According to an embodiment of the invention, an enzyme stabilizing system may include a mixture of carbonate and bicarbonate and can also include other ingredients to stabilize certain enzymes or to enhance or maintain the effect of the mixture of carbonate and bicarbonate. An enzyme stabilizer may further include boron compounds or calcium salts. For example, enzyme stabilizers may be boron compounds selected from the group consisting of boronic acid, boric acid, borate, polyborate and combinations thereof.
Enzyme stabilizers may also include chlorine bleach scavengers added to prevent chlorine bleach species present from attacking and inactivating the enzymes especially under alkaline conditions. As one skilled in the art shall ascertain, methods according to the invention are based upon the activity of enzyme compositions cleaning wash water sources. Therefore, suitable chlorine scavenger anions may be added as an enzyme stabilizer to prevent the deactivation of the enzyme compositions according to the invention. Exemplary chlorine scavenger anions include salts containing ammonium cations with sulfite, bisulfite, thiosulfite, thiosulfate, iodide, etc. Antioxidants such as carbamate, ascorbate, etc., organic amines such as ethylenediaminetetracetic acid (EDTA) or alkali metal salt thereof, monoethanolamine (MEA), and mixtures thereof can also be used.
According to alternative embodiments of the invention, the enzyme compositions for use in the methods of the present invention are preferably free of enzyme stabilizers. According to a preferred embodiment, the enzyme compositions are free of any enzyme-stabilizing Ca or Mg source.
Detergent Compositions
Methods according to the invention use an aqueous use solution which may comprise a detergent composition in combination with the enzyme composition. The methods according to the invention are directed to cleaning a wash water source, having numerous beneficial results, including enhancing the detergency of a cleaning agent used in combination with the methods of the invention. According to an embodiment of the invention, enzymes are cleaning the wash water and not substrates within a cleaning application, largely due to the short duration of contact between enzymes and a substrate. However, the enzyme compositions according to the invention assist in cleaning substrates of a cleaning application by enhancing the ability of a detergent to work in the water rather than being consumed by the soils in the wash water. As a result, a detergent composition is more effective on the surface of the substrates for cleaning purposes.
According to the invention, the detergent composition may be liquids or solids, including for example molded compositions, as are appreciated by those skilled in the art. Pastes and gels can be considered types of liquid. Powders, agglomerates, pellets, tablets, and blocks can be considered types of solid. For example, detergent compositions may be provided in the form of blocks, pellets, powders (i.e., mixture of granular dry material), agglomerates and/or liquids under room temperature and atmosphere pressure conditions. Powder detergents are often prepared by mixing dry materials or by mixing a slurry and drying the slurry. Pellets and blocks are typically provided with a size that is determined by the shape or configuration of the mold or extruder through which the detergent composition is compressed. Pellets are generally characterized as having an average diameter of about 0.5 cm to about 2 cm. Blocks are generally characterized as having an average diameter of greater than about 2 cm, preferably between about 2 cm and about 2 ft, and can have an average diameter of between about 2 cm and about 1 ft. According to a preferred embodiment, a solid block is at least 50 grams.
According to certain embodiments of the invention, the detergent composition is substantially free of phosphorous. Substantially phosphorous-free refers to a composition to which phosphorous-containing compounds are not added. In an exemplary embodiment, the cleaning composition includes less than approximately 10% phosphates, phosphonates, and phosphites, or mixtures thereof by weight. Preferably, the detergent composition includes less than approximately 5% phosphates, phosphonates, and phosphites by weight. More preferably, the detergent composition includes less than approximately 1% phosphates, phosphonates, and phosphites by weight. Most preferably, the detergent composition includes less than approximately 0.1% phosphates, phosphonates, and phosphites by weight.
Additional description of detergent compositions, and methods of formation of the same, suitable for use according to the invention are disclosed, for example, in U.S. Pat. Nos. 7,674,763, 7,153,820, 7,094,746 and 6,924,257 and U.S. patent application Ser. No. 12/695,370, filed Jan. 28, 2010 titled “Method for Washing an Article using a Molded Detergent Composition,” the contents of which are incorporated by reference in its entirety.
Use of detergent compositions with the aqueous use solution according to the invention can be used in conventional detergent dispensing equipment. For example, commercially available detergent dispensing equipment which can be used according to the invention are available under the name Solid System™ from Ecolab, Inc. Use of such dispensing equipment results in the erosion of a detergent composition by a water source to form the aqueous use solution according to the invention.
Additional Components
Methods according to the invention using an aqueous use solution may further comprise additional components to be used in combination with the enzyme composition, detergent composition and/or combination enzyme and detergent composition. Additional components which can be incorporated into the enzyme composition, detergent composition, combined enzyme and detergent composition and/or added independently to the water source include solvents, dyes, fragrances, anti-redeposition agents, corrosion inhibitors, buffering agents, defoamers, antimicrobial agents, preservatives, chelators, bleaching agents and combinations of the same.
Exemplary aesthetic additives which can be used as additional components include dyes and fragrances, such as dye #2, and a preferred fragrance includes lemon fragrance. Exemplary anti-redeposition agents which can be incorporated according to the invention include sodium carboxy methylcellulose, sodium polyacrylate, and hydroxypropyl cellulose. Exemplary corrosion inhibitors which can be incorporated according to the invention include triethanolamine, and doderylamine. Numerous additional corrosion inhibitors can be incorporated and are described, for example, in U.S. patent application Ser. No. 12/617,419, filed Nov. 12, 2009 titled “Warewashing Composition for Use in Automatic Dishwashing Machines, and Methods for Manufacturing and Using,” the contents of which are incorporated by reference in its entirety. Additional anti-etch agents can be further utilized to reduce the etching or corrosion found on certain surfaces treated with detergent compositions. Examples of suitable anti-etch agents include adding metal ions to the composition such as zinc, zinc chloride, zinc gluconate, aluminum, and beryllium. However, according to certain embodiments of the invention, anti-etch agents are not required for use of the methods of the present invention.
Exemplary buffering agents which can be incorporated according to the invention include sodium acetate, potassium dihydrogen phosphate, and sodium borate. Exemplary defoamers which can be incorporated according to the invention include polymeric silicone derivatives, and alkynol derivatives. Exemplary antimicrobial agents which can be incorporated may include paraben materials such as propyl paraben. Additional antimicrobial agents which can be incorporated according to the invention include tert-amylphenol, quaternary ammonium compounds, and active halogen containing compounds. Exemplary chelators which can be incorporated according to the invention include nitrilotriacetic acid (NTA) and ethylenediaminetetraacetic acid (EDTA) to help control scale, remove soils, and/or sequester metal ions such as calcium, magnesium and iron.
Bleaching agents may also be incorporated according to the invention in order to lighten or whiten a substrate, and can include bleaching compounds capable of liberating an active halogen species, such as Cl 2 , Br 2 —OCl— and/or —OBr—, or the like, under conditions typically encountered during the cleansing process. Examples of suitable bleaching agents include, but are not limited to: chlorine-containing compounds such as chlorine, a hypochlorite or chloramines. Examples of suitable halogen-releasing compounds include, but are not limited to: alkali metal dichloroisocyanurates, alkali metal hypochlorites, monochloramine, and dichloroamine. Encapsulated chlorine sources may also be used to enhance the stability of the chlorine source in the composition (see, for example, U.S. Pat. Nos. 4,618,914 and 4,830,773, the disclosures of which are incorporated by reference herein). The bleaching agent may also include an agent containing or acting as a source of active oxygen. The active oxygen compound acts to provide a source of active oxygen and may release active oxygen in aqueous solutions. An active oxygen compound can be inorganic, organic or a mixture thereof. Examples of suitable active oxygen compounds include, but are not limited to: peroxygen compounds, peroxygen compound adducts, hydrogen peroxide, perborates, sodium carbonate peroxyhydrate, phosphate peroxyhydrates, potassium permonosulfate, and sodium perborate mono and tetrahydrate, with and without activators such as tetraacetylethylene diamine. It is to be appreciated by a skilled artisan that certain embodiments of the invention preferably use compositions that are chlorine-free to promote the use of enzymes according to the invention.
One skilled in the art shall ascertain additional components that may be used in combination with the methods of the present invention.
All publications and patent applications in this specification are indicative of the level of ordinary skill in the art to which this invention pertains. All publications and patent applications are herein incorporated by reference to the same extent as if each individual publication or patent application was specifically and individually indicated by reference.
EXAMPLES
Embodiments of the present invention are further defined in the following non-limiting Examples. It should be understood that these Examples, while indicating certain embodiments of the invention, are given by way of illustration only. From the above discussion and these Examples, one skilled in the art can ascertain the essential characteristics of this invention, and without departing from the spirit and scope thereof, can make various changes and modifications of the embodiments of the invention to adapt it to various usages and conditions. Thus, various modifications of the embodiments of the invention, in addition to those shown and described herein, will be apparent to those skilled in the art from the foregoing description. Such modifications are also intended to fall within the scope of the appended claims.
Example 1
Field testing evaluated the viability of adding an enzyme to Apex™ ware washing detergent in order to reduce starch levels in the wash water of a commercial dish machine sump. Testing hypothesized that achieving a reduction in starch would necessitate less detergent for food soils while yielding better glassware results. A positive test result for a product was achieved if compared to baseline product the formulation with the enzyme composition demonstrated decrease in starch levels in the dish machine sump. In addition comparable capsule yield and glassware results were analyzed. Power Fusion™ was used as the baseline product (control) having the following formulation:
Raw Material
% of Formula
Potassium Hydroxide
9.1
Hydroxyethylidene-diphosphonic acid
6.3
Corrosion Inhibitor
0.1
Nonionic Surfactant
3.7
Sodium Carbonate
49.5
STPP
25.0
Silicate
3
Enzyme
0
Chlorine
3.3
TOTAL
100.0
Baseline testing consisted of monitoring detergent product usage through total rinse time, rack counts and product inventory for several months. In addition, the general condition of the glassware was observed. Weekly field testing was completed to obtain the following data for the enzyme-containing formulation: product yield (rinse time, rack counts and product inventory); product performance (glass and silverware samples were monitored to check for significant increases or decreases in ware quality); customer perception; and starch levels (water samples were taken from the dish machine sump and tested for the presence of starch). Starch levels were obtained and measured according to the following methods: (1) Obtain sump sample and store in refrigerator to halt the enzyme process and preserves the sample from spoilage; (2) Remove sample from refrigerator and shake to mix solution; (3) Dose out a volumetric amount of 50 mls into a graduated cylinder; (4) Using suction filtration, pour sample into the filter apparatus; (5) Add two disposable pipets of iodine solution (taken from a starch amylase test) to the solution in the filter apparatus (approximately 4 mL); (6) Wait until all liquid is drawn through and only the soil remains on the filter paper; (7) Turn off suction and remove filter paper to set aside to dry.
The enzyme tested was an amylase enzyme. Formulations were adjusted to remove chlorine and increase sodium carbonate concentration from the above baseline ware wash formula. The amylase enzymes are commercially available as Purastar ST (RM320039) and Stainzyme 12T (320100). Formulations using a 1% Amylase and 0.1% Amylase were tested. The enzyme was subsequently switched to Stainzyme for further testing of a different amylase enzyme. Formulations using a 0.1% Stainzyme and 0.05% Stainzyme were also tested. Starch levels were tested weekly in the sump and were analyzed by visual assessments obtained from gross quantification through filtration. The presence of starch on the filter paper was indicated by blue and brown specs on the filter paper.
The tested enzyme products had the following formulations:
% of
% of
% of
Raw Material
Formula
Formula
Formula
Potassium Hydroxide
9.1
9.1
9.1
Hydroxyethylidene-diphosphonic acid
6.3
6.3
6.3
Corrosion Inhibitor
0.1
0.1
0.1
Nonionic Surfactant
3.7
3.7
3.7
Sodium Carbonate
51.8
52.7
52.75
STPP
25.0
25.0
25.0
Silicate
3
3
3
Enzyme
1.0
0.1
0.05
Chlorine
0
0
0
TOTAL
100
100
100
Results. Change from baseline detergent use to 1.0% Amylase resulted in an initial increase in starch levels, hypothesized to result from the enzymes removal of starch built-up on the sump walls. Once this starch was removed, the enzyme was able to handle the normal, daily starch load, with little to no starch detected in the sump by week four. The ware wash systems were subsequently switched from 1% to 0.1% Amylase product. An initial increase in starch levels were observed in the sump. This elevated starch level was observed for four weeks. Thereafter, the level detected increased over the next five weeks.
After completed testing with the Amylase formulas, the enzyme Stainzyme was tested. First, another Apex™ baseline was conducted for two weeks and tested for the presence of starch. Thereafter, the 0.1% Stainzyme formula was used. An initial increase in the starch levels was again detected. The peak, similar to the one observed in the Apex™ baseline for the Amylase test was hypothesized to result from the enzyme cleaning the starch build-up off the walls of the sump that had accumulated during normal Apex™ use. By week three the starch levels subsided. The ware wash systems were subsequently switched from 0.1% Stainzyme product to the 0.05% formulation. Immediately upon switching to the 0.05% Stainzyme formula, starch level increased. Notably, a reverse osmosis water treatment system was installed for the ware wash machine during testing with the 0.05% Stainzyme formulation, likely deactivating the enzyme.
Both amylase enzyme formulations, Amylase and Stainzyme, reduced starch levels in the sump of the treated ware wash systems, while maintaining good cleaning performance on the wares. Increased concentration of the enzymes provided enhanced results. For the Amylase product, the 1.0% formulation took approximately four weeks to clean out the sump and then maintained a very low starch level compared to the Apex™ baseline. However, when the concentration of Amylase was reduced the starch levels increased. For the Stainzyme product, the 0.1% formula took only three weeks to clean out the sump and to yield low starch levels. When the Stainzyme concentration was reduced, the starch levels in the sump increased as this lower level of enzyme was unable to keep up with the starch loads introduced to the sump.
In addition to monitoring starch levels, customer feedback and product performance did not change throughout the testing, illustrating no significant change, either increase or decrease, in the amount of streaking and spotting on glassware.
The inventions being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the inventions and all such modifications are intended to be included within the scope of the following claims. | Methods for use of enzymes for sustainable wash water maintenance are disclosed. The invention relates to use of enzymes for removing soils from wash water sources in a variety of cleaning applications. The invention cleans wash water sources, prevents the re-deposition of soils on treated surfaces and enhances detergency. Methods of wash water maintenance according to the invention provide sustainable practices by improving water quality and minimizing water and energy consumption in wash systems. | 2 |
FIELD OF THE INVENTION
[0001] The present invention relates to a crosslinked composition comprising a core-shell copolymer, to a process for obtaining it and to its uses. In particular, it describes a crosslinked composition comprising an elastomer and a core-shell copolymer, a process for obtaining it based on high-temperature crosslinking, and its uses.
[0002] The crosslinked composition of the invention is applicable in the manufacture of certain articles, such as tyres, isolating seals and gaskets, and pipes for transporting fluids such as those used in the automobile industry, for example in the brake or cooling circuits. Tyre technology is described in applications WO 00/05300, WO 00/05301 and EP 501 227, the content of which is incorporated in the present application. Examples of tyre parts that can benefit from these compositions that may be mentioned include, non-limitingly, the crown (padding on the bead or apex), the sidewalls, the carcass and rubber mixes containing steel wires, the shoulders, but also the beads, the impermeable plies, the chafers and the tread. Other applications may make use of the compositions of the invention, such as for the manufacture of belts (such as transmission belts), electrical cable jackets, shoe soles, seals, resilient links, pipes and hoses, membranes or anti-vibration devices, and also for applications in the mechanical industry, in the aeronautical industry, in transportation, in the electrical industry, in the building industry, in medicine and in pharmacy, and in the nuclear industry. In these various applications, the elastomers may of course be combined with other materials, such as metals, textiles and certain plastics.
[0003] In one particular embodiment, the crosslinked compositions of the invention may be converted like thermoplastics. This is because, for some applications (isolating seals and gaskets or fluid transfer pipes), it is desirable to have materials which, while still having properties similar to those of elastomers, and especially an ability to withstand large deformations without breaking and the capability of returning to their initial geometry after the application of tensile or compressive forces, even repeatedly applied, and also good heat resistance, chemical resistance and weatherability, can be processed by the techniques and equipment used by thermoplastic converters, and to do so mainly in order to allow these articles and the scrap produced during their manufacture to be recycled, which recycling is not permitted when elastomers are used.
PRIOR ART AND THE TECHNICAL PROBLEM
[0004] U.S. Pat. No. 4,130,535 discloses “thermoplastic elastomers” based on polyolefins that have a structure consisting of an uncrosslinked polypropylene matrix and crosslinked nodules of an ethylene-propylene-diene monomer (EPDM) terpolymer, so as to have, at the operating temperature (which is below the melting point of polypropylene) a behaviour similar to that of elastomers after vulcanization, while heating them above this melting point allows them to be processed like thermoplastics. Although these materials do have a number of properties equivalent to those of elastomers, they exhibit a high tension set (greater than 50%) at temperatures above 100° C., which makes their use hardly appropriate for the manufacture of articles intended to be used in regions where temperatures above 100° C. prevail, as may be the case for isolating seals and gaskets or else pipes, hoses, tubes and the like designed to transport fluids in the engine coMPartment of a motor vehicle.
[0005] To solve this problem, Patent EP 0 840 763 A1 proposes a solution based on the use of a crosslinked elastomer of the thermoplastic conversion type obtained by crosslinking a blend, denoted hereafter by “Vegaprene®”, comprising a poly(octene/ethylene)-based elastomer obtained by metallocene catalysis and a maleic-anhydride-grafted polyolefin. Although this solution is satisfactory, it nevertheless remains limited to certain applications.
[0006] This is because the properties of the blends are in general different from those expected by simple linear interpolation of the properties of the constituents taken separately (elastomers and plastics). Synergy effects may sometimes be present, but other cases exist in which the properties are slightly inferior. This may be connected with the morphology of the various phases, the distribution of the fillers and plasticizers, the nature of the interfaces or the distribution of the vulcanization bridges in the various phases. To alleviate these effects it is general practice to use coMPatibilizers or co-agents, but these are expensive and difficult to incorporate into the blends.
[0007] In particular in the case of repeated-stress resistance properties, the fatigue behaviour of the compounds is of paramount importance. This may be achieved using co-agents such as zinc methacrylate. However, because of the polarity of this compound it is difficult to disperse it in the blends. Furthermore, its high reactivity with metal at high temperature results in blends that adhere to the mixing equipment. Consequently, it is little used. Another useful property may be the high-elongation resistance. This property is difficult to obtain with the blends described in EP 0 840 763 A1.
[0008] Finally, in certain cases the improvement in compression set, generally termed S C , obtained by applying the method described in EP 840 763 A1 may prove to be insufficient.
[0009] To solve the problems described above, and many others, a solution has been found based on a crosslinked composition comprising at least one elastomer and at least one core-shell copolymer and optionally a thermoplastic polymer. This solves the aforementioned problems without adversely modifying the other mechanical characteristics of the blends (dynamic properties, dissipation, hardness, rebound, etc.). The polymer blend is easy to disperse using the method described in the present application. In addition, it has the advantage of not adhering to the equipment.
[0010] Another approach for solving these problems has been described in Patent Application WO 2005/082996, which discloses a crosslinked composition comprising:
at least one elastomer; at least one triblock copolymer; and at least one thermoplastic polymer.
[0014] As this solution is satisfactory, a person skilled in the art would have no reason to substitute the triblock copolymer with a core-shell copolymer. The present invention is therefore an alternative to the solution of WO 2005/082996, making it possible to enlarge the range of products and applications associated with this technology.
BRIEF DESCRIPTION OF THE INVENTION
[0015] The first subject of the invention is therefore a crosslinked composition comprising, in parts by weight, the following different constituents:
>20 to 100 parts of at least one elastomer (I); >2 to 50 parts of at least one core-shell copolymer (II); and 0 to 100 parts of at least one thermoplastic polymer (III),
the components (I), (II) and (III) being different in chemical nature and/or of different structure.
[0019] According to the invention, the elastomer (I) and the thermoplastic (III) are not of core-shell form.
[0020] The subject of the present invention is also a process for producing a crosslinked composition as defined above, characterized in that it comprises:
the blending of an elastomer (I) with a core-shell copolymer (II) optionally in the presence of a thermoplastic polymer (III), in particular a grafted polyolefin, a plasticizer, fillers and/or additives, and a suitably chosen crosslinking system, followed by the crosslinking of this blend at a suitable temperature.
[0023] In a preferred method of implementing the process according to the invention, the temperature at which the crosslinking is carried out is between 150 and 320° C.
[0024] This process may be carried out in an internal mixer, or, as a variant, in a twin-screw extruder or a Buss® co-kneader. The resulting mass is, in this case, calendared or extruded, then cooled and granulated. The granules thus obtained are ready to be converted (by heating these granules) into sheets, plates, extrusions, tubes or other desired products.
[0025] The subject of the present invention is also the use of a crosslinked composition as defined above for the production of seals and/or gaskets for isolating and/or for sealing, such as those employed for thermal or acoustic insulation and/or for sealing against water and moisture, especially in buildings, and for the motor vehicle industry (for example door seals).
[0026] The subject of the present invention is also the use of such a composition in the production of pipes, tubes, hoses, nozzles, fittings or the like for transporting fluids. As examples, mention may be made of pipes, hoses and other elements designed to convey fluids used by the motor vehicle industry in brake, cooling, power-steering or air-conditioning circuits. Thus, the subject of the invention is especially seals and gaskets for isolating and/or for sealing that comprise the crosslinked composition defined above. In addition, however, the invention covers ducts such as pipes, hoses, nozzles and fittings comprising the crosslinked composition defined above.
[0027] Mention may also be made of the use of the crosslinked composition of the invention in the production of belts, tyres, electrical cable jackets, and shoe soles.
[0028] According to the invention, the composition may contain one or more elastomers (I) associated with one or more core-shell copolymers (II) and optionally one or more thermoplastic polymers.
[0029] The Applicant has found, surprisingly, that the use of a core-shell copolymer blended with several elastomers (I) allows the use of elastomers that are normally chemically incoMPatible (for example a blend of natural rubber (NR) with 2-chloro-1,3-butadiene, usually called chloroprene (CR), by coMPatibilizing them. This advantage allows the composition of the invention to be used in a wide range of applications, greater than those of the compositions of the prior art. The term “coMpatibilize” is understood to mean that the physico-chemical properties of each of the elastomers are retained.
DETAILED DESCRIPTION OF THE INVENTION
[0030] With regard to the elastomer (I), this may be chosen from the group comprising natural rubbers (NR), synthetic rubbers (BR), elastomers polymerized by metallocene catalysis, modified or unmodified polyolefin elastomers, ethylene-propylene rubbers (EPR), ethylene-propylene-diene monomers (EPDM), long-chain polyacrylates, such as polybutyl acrylate or poly(2-ethylhexyl acrylate), fluoroelastomers (FPM), such as tetrafluoroethylene-based copolymers, and silicone elastomers.
[0031] The term “synthetic rubber (BR)” is understood to mean conjugated polydienes such as polybutadiene, polyisoprene and their block or random copolymers, especially styrene-diene copolymers with a predominantly diene content.
[0032] For the purpose of the present invention, the expression “elastomer polymerized by a metallocene catalyst” is understood to mean any elastomer consisting of a homopolymer, copolymer or terpolymer polymerized by means of a metallocene catalyst, such as octene/ethylene polymers, also called polyoctenes, which are available from DuPont Dow Elastomers (DDE) under the trade name ENGAGE.
[0033] With regard to the core-shell copolymer (II), this is in the form of fine particles having an elastomer core and at least one thermoplastic shell, the particle size being generally less than 1 μm and advantageously between 50 and 300 nm. By way of example, of the core, mention may be made of isoprene homopolymers or butadiene homopolymers, isoprene-butadiene copolymers, copolymers of isoprene with at most 98 wt % of a vinyl monomer and copolymers of butadiene with at most 98 wt % of a vinyl monomer. The vinyl monomer may be styrene, an alkylstyrene, acrylonitrile, an alkyl(meth)acrylate, or butadiene or isoprene. The core of the core-shell copolymer may be completely or partly crosslinked. All that is required is to add at least difunctional monomers during the preparation of the core; these monomers may be chosen from poly(meth)acrylic esters of polyols, such as butylene di(meth)acrylate and trimethylolpropane trimethacrylate. Other difunctional monomers are, for example, divinylbenzene, trivinylbenzene, vinyl acrylate, vinyl methacrylate and triallyl cyanurate. The core can also be crosslinked by introducing into it, by grafting or as a comonomer during the polymerization, unsaturated functional monomers such as anhydrides of unsaturated carboxylic acids, unsaturated carboxylic acids and unsaturated epoxides. Mention may be made, by way of example, of maleic anhydride, (meth)acrylic acid and glycidyl methacrylate. The crosslinking may also be carried out by using the intrinsic reactivity of the monomers, for example the diene monomers.
[0034] The shell(s) are styrene homopolymers, alkylstyrene homopolymers or methyl methacrylate homopolymers, or copolymers comprising at least 70 wt % of one of the above monomers and at least one comonomer chosen from the other above monomers, another alkyl(meth)acrylate, vinyl acetate and acrylonitrile. The shell may be functionalized by introducing into it, by grafting or as a comonomer during the polymerization, unsaturated functional monomers such as anhydrides of unsaturated carboxylic acids, unsaturated carboxylic acids and unsaturated epoxides. Mention may be made, for example, of maleic anhydride, (meth)acrylic acid glycidyl methacrylate, hydroxyethyl methacrylate and alkyl(meth)acrylamides. By way of example, mention may be made of core-shell copolymers having a polystyrene shell and core-shell copolymers having a PMMA shell. The shell may also contain imide functional groups, either by copolymerization with a maleimide or by chemical modification of the PMMA by a primary amine. Advantageously, the molar concentration of the imide functional groups is 30 to 60% (relative to the entire shell). There are also core-shell copolymers having two shells, one made of polystyrene and the other, on the outside, made of PMMA. Examples of copolymers and their method of preparation are described in the following patents: U.S. Pat. No. 4,180,494, U.S. Pat. No. 3,808,180, U.S. Pat. No. 4,096,202, U.S. Pat. No. 4,260,693, U.S. Pat. No. 3,287,443, U.S. Pat. No. 3,657,391, U.S. Pat. No. 4,299,928, U.S. Pat. No. 3,985,704 and U.S. Pat. No. 5,773,320.
[0035] Advantageously, the core represents in this invention, by weight, 5 to 90% of the core-shell copolymer and the shell 95 to 10%.
[0036] By way of example of a copolymer, mention may be made of that consisting (i) of 70 to 75 parts of a core comprising at least 93 mol % of butadiene, 5 mol % of styrene and 0.5 to 1 mol % of divinylbenzene and (ii) of 25 to 30 parts of two shells essentially of the same weight, the inner one made of polystyrene and the outer one made of PMMA.
[0037] Another example that may be mentioned has a core made of a butyl acrylate/butadiene copolymer and a shell made of PMMA.
[0038] All these core-shell copolymers are sometimes called soft/hard copolymers because the core is made of an elastomer.
[0039] It would not be outside the scope of the invention to use core-shell copolymers such as hard/soft/hard copolymers, that is to say copolymers having, in this order, a hard core, a soft shell and a hard shell. The hard parts may consist of the polymers of the shell of the above soft/hard copolymers and the soft part may consist of the polymers of the core of the above soft/hard copolymers.
[0040] For example, mention may be made of those described in EP 270 865 and those consisting, in the following order, of
a core made of a methyl methacrylate/ethyl acrylate copolymer; a shell made of a butyl acrylate/styrene copolymer; and
[0043] a shell made of a methyl methacrylate/ethyl acrylate copolymer.
[0044] There are also other types of core-shell copolymer such as hard (core)/soft/semi-hard copolymers. CoMPared with the previous ones, the difference stems from the “semi-hard” outer shell which consists of two shells, namely the intermediate shell and the outer shell. The intermediate shell is a copolymer of methyl methacrylate, styrene and at least one monomer chosen from alkyl acrylates, butadiene and isoprene. The outer shell is a PMMA homopolymer or copolymer.
[0045] Mention may be made, for example, of those consisting, in the following order, of:
a core made of a methyl methacrylate/ethyl acrylate copolymer; a shell made of a butyl acrylate/styrene copolymer; a shell made of a methyl methacrylate/butyl acrylate/styrene copolymer; and a shell made of a methyl methacrylate/ethyl acrylate copolymer.
[0050] With regard to the thermoplastic polymer (III), this is chosen for example from modified or unmodified polyolefins, polyamides, polyesters, thermoplastic polyurethanes, fluoropolymers and chlorinated polymers such as polyvinyl chloride (PVC). Advantageously, the thermoplastic polymer (III) is a functionalized polyolefin. Preferably, the thermoplastic polymer (III) is a grafted polyethylene chosen from the group comprising polyethylenes, polypropylenes and ethylene-propylene polymers grafted with acrylic acid, maleic anhydride or glycidyl methacrylate.
[0051] With regard to the constituents of the composition of the invention, the proportions of the elastomer (I), the core-shell copolymer (II) and the thermoplastic polymer (III) are advantageously 60 to 90 parts of (I), 5 to 20 parts of (II) and 48 to 5 parts of (III).
[0052] According to one embodiment of the invention, the contents of elastomer (I), core-shell copolymer (II) and thermoplastic polymer (III) of the composition are between 30 and 80% in the case of (I), 2 to 35% in the case of (II) and 5 to 80% in the case of (III).
[0053] According to a preferred embodiment of the invention, the contents of elastomer (I), core-shell copolymer (II) and thermoplastic polymer (III) of the composition are between 40 and 70% in the case of (I), 2 to 20% in the case of (II) and 10 to 70% in the case of (III).
Other Constituents of the Composition:
[0054] Advantageously, the crosslinked composition according to the invention may also include a polyacrylic elastomer, such as an ethylene/acrylate/acrylic acid terpolymer or a styrene/acrylonitrile/acrylate terpolymer, which acts both as a UV stabilize and as a film-forming agent and which makes it possible to improve the surface appearance of the composition when it is processed by extrusion. When such a polyacrylic elastomer is used, it is preferably with a content of 2 to 20 parts by weight per 100 parts by weight of the elastomer/core-shell copolymer blend.
[0055] Also advantageously, the composition of the invention may contain, in addition, a plasticizer whose presence makes it possible to increase its melt flow index and thereby make it easier to process it, and to adjust the hardness of the products resulting from this processing, depending on the desired hardness value. Preferably, this plasticizer is a paraffinic plasticizer of the type of those sold by Total under the brand name PLAXENE or by Exxon under the brand name FLEXON, and is used in an amount of 5 to 120 parts by weight per 100 parts by weight of the elastomer/core-shell copolymer (II) blend and optionally of the elastomer/core-shell copolymer (II)/thermoplastic polymer (III) blend. However, other plasticizers such as a polyalkylbenzene may also be suitable.
[0056] The composition may also include fillers of the light-coloured type (silicas, carbonates, clays, chalk, kaolin, etc.) or carbon blacks. The use of the latter fillers proves to be particularly advantageous as they make it possible not only to adjust certain mechanical properties of the composition according to the invention, such as the tensile strength and the tensile modulus, but also to give it excellent UV resistance. When such fillers are present in the composition, their content is advantageously from 5 to 100 parts by weight per 100 parts by weight of the elastomer (I)/core-shell copolymer (II)/optional thermoplastic polymer (III) blend.
[0057] When it is necessary to add fillers, and especially carbon black, into the composition so as to give them good mechanical properties and/or UV resistance (properties needed for some applications), the Applicant has found, surprisingly, that the composition based on a core-shell polymer, which facilitates the processing of the filled composition, reduces its heat-up when blending its various constituents and reduces its viscosity, coMPared with filled compositions of the prior art.
[0058] The composition may further contain a certain proportion of triblock copolymers, for example in an amount of 0.01 to 200 and especially 0.1 to 10% of the composition.
[0059] The crosslinked composition may furthermore contain other additives conventionally employed in the polymer industry such as, for example, antistatic agents, lubricants, antioxidants, coupling agents, pigments, dyes, processing aids and adhesion promoters, depending on the properties that it is desired to give it, provided that, of course, these additives are coMPatible with the other constituents of the composition of the invention.
[0060] The composition according to the invention is said to be “crosslinked” because its production involves crosslinking the elastomer that forms part of its composition. Consequently, the composition according to the invention contains, before crosslinking, at least one crosslinking system comprising one or more crosslinking agents suitably chosen according to the nature of its constituent polymers, especially its constituent elastomers, and one or more crosslinking promoters, the function of which is to activate the crosslinking reaction kinetics and increase the crosslinking density. The crosslinking agent is chosen according to the temperature for processing and crosslinking the constituent elastomers of the composition.
[0061] According to a preferred embodiment of the invention, this crosslinking system comprises, as crosslinking agent(s), one or more organic peroxides chosen from the group comprising dicumyl peroxide, 1,3-bis(t-butylperoxyisopropyl)benzene, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane and 1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane and, as crosslinking promoter(s), one or more compounds chosen from the group comprising zinc oxide, stearic acid, N,N-m-phenylenedimaleimide, triallyl or triisoallyl cyanurates, methacrylates (such as tetrahydrofurfuryl or 2-phenoxyethyl methacrylates), dimethacrylates (such as ethylene glycol, tetraethylene glycol, 1,4-butanediol or zinc dimethacrylates), trimethacrylates (such as trimethylolpropane trimethacrylate), diacrylates (such as zinc diacrylate) and triacrylates.
[0062] According to another preferred embodiment of the invention, the crosslinking system is a sulphur-based system that comprises, apart from zinc oxide and/or stearic acid as crosslinking promoter(s), one or more sulphur-donor accelerators such as 4,4-dithiomorpholine, tetramethylthiuram disulphide, dipentamethylenethiuram tetrasulphide or zinc dibutyldithiocarbamate, and optionally an anti-reversion agent such as 1,3-bis(citraconimidomethyl)benzene.
[0063] According to one particularly preferred embodiment of the invention, the crosslinking system comprises, as crosslinking agent, a phenolic resin chosen from reactive alkylated methylphenol-formaldehyde and bromomethylphenol-formaldehyde resins and, as crosslinking promoter, a chlorinated polymer such as a chlorinated or chlorosulphonated polyethylene or a polychloroprene, optionally combined with zinc oxide and/or stearic acid. The latter crosslinking system makes it possible to obtain elastomers which, apart from having extremely satisfactory mechanical properties and tension and compression set values, are characterized by an attractive surface appearance.
[0064] In all cases, the crosslinking agent or agents are preferably present in the formulation in an amount from 1 to 10 parts by weight per 100 parts by weight of the elastomer (I)/core-shell copolymer (II)/optional thermoplastic polymer (III) blend, whereas the crosslinking promoters are preferably present in an amount from 0.5 to 12 parts by weight per 100 parts by weight of the blend.
[0065] When the vulcanization system is a sulphur-based system, the sulphur-donor accelerator or accelerators are preferably present in the formulation in an amount from 1 to 7 parts by weight per 100 parts by weight of the elastomer (I)/core-shell copolymer (II)/optional thermoplastic polymer (III) blend.
[0066] According to the invention, the crosslinking of the composition may be carried out by means of two crosslinking systems. As an example, it is possible to use a sulphur-based crosslinking system combined with a crosslinking system based on organic peroxides or a crosslinking system based on a phenolic resin and a crosslinking system based on organic peroxides.
[0067] Depending on the nature and the proportions of (I) and (III), the compositions of the invention may be mentioned using the techniques and equipment employed for processing thermoplastics, namely thermoforming, injection moulding, extrusion, forming, etc. In this particular case, the compositions of the invention are referred to as being “thermoplastic-processable”. As examples of such compositions, mention may be made of those in which the elastomer I consists of a homopolymer, copolymer or terpolymer polymerized by means of a metallocene catalyst and the polymer III is present. Advantageously, the polymer III is a functionalized polyolefin, preferably a grafted polyolefin. It may be chosen from the grafted polyolefins mentioned above. For example, the I/III blends known by the name “Vegaprene®”, such as those described for example in the patents FR 2 667 016, WO 97/44390, U.S. Pat. No. 4,130,535 or EP 0 840 763 B1, may be mentioned.
[0068] The crosslinked thermoplastic-processable compositions according to the invention, while still exhibiting mechanical properties, in terms of hardness, tensile strength and elongation at break, which are equivalent to those of the abovementioned thermoplastic elastomers of the prior art, have better compression set and tension set properties than those elastomers. This advantage is observed not only in the short term but also in the long term, where the compositions according to the invention have a lower tendency to creep.
[0069] With regard to the production process, this comprises the compounding of at least one elastomer (I), at least one core-shell copolymer (II) optionally in the presence of a thermoplastic polymer (III), a plasticizer and fillers and additives, and the crosslinking of this compound by an appropriate crosslinking system at a suitably chosen temperature.
[0070] According to one particularly preferred method of implementation, the production process according to the invention comprises the following:
a) the elastomer, core-shell copolymer (II) and the crosslinking system, optionally in the presence of the thermoplastic polymer, the polyacrylic elastomer, the plasticizer, the fillers and/or the additives, are compounded; b) this compound is heated to a temperature of between 150 and 320° C.; and c) this temperature is maintained for a time of between 1 and 15 minutes.
EXAMPLES
[0074] Various formulations were prepared according to the following method: the ingredients needed to produce the crosslinked composition were introduced into an internal mixer and compounded with suitable shear. While continuing the shearing, the internal temperature of the mixer was raised to 170° C. and, when this temperature was reached, the compounds were maintained thereat for about 5 minutes. The compounds thus obtained on exiting the mixer were cooled and granulated.
[0000] The following were determined:
the Shore A hardness according to the method described in the NF standard T 46-052;
the tensile strength (TS) and the elongation at break (EB), according to the method described in the ISO 37 standard, of each of the compositions thus produced, and also: the compression set (S C ) after being compressed by 25% for 22 hours at 100° C., according to the method described in the ISO 815 standard; and the tension set (S T ) after being stretched by 20% for 70 hours according to the method described in the ISO 2285 standard.
[0079] The following tables give the compositions studied, expressed in parts by weight, and the results obtained.
[0080] In the following tables:
ML and MH denote the minimum and maximum torques, Max-Min denotes the difference between these two torques, and tc(5), tc(50) and tc(95) denote the times to reach 5%, 50% and 95% of the maximum torque respectively; MBS1 denotes a core-shell copolymer having an essentially butadiene/styrene-based core and a PMMA shell, sold by Arkema®; MBS2 denotes a 50/50 wt % core-shell copolymer composed of an essentially butadiene/styrene-based core and a PMMA shell; and
[0084] MBS3 denotes a core-shell copolymer made up essentially from a substructured core, consisting of predominantly a PMMA central portion with a butadiene-based peripheral layer, and from a PMMA shell.
[0085] The compounding of the rubber was carried out in two steps using a direct method: the first step used an internal mixer in which the NR was preheated for one minute with a rotor temperature of 60° C. and a rotor speed of 60 rpm. Next, all the reactants with the exception of the vulcanization system were added and the speed of the rotors was increased to 80 rpm, taking measures to ensure that the compounding temperature did not exceed 140° C. The compound was dropped after 6 minutes. The peak temperature of the compound was about 160° C. The second step consisted in manually working the rubber on an open mixer using a cutting tool. The temperature of the rolls was 40° C. and the coefficient of friction 1.2. The vulcanization system was incorporated and at least three passes were made in the end. This working lasted about twenty minutes. The results are given in Table 1 below:
[0000]
TABLE 1
A
C
Natural rubber (NR)
phe
80
80
Butadiene (BR)
phe
20
20
MBS1
phe
10
ZnO
phe
5
5
Stearic acid
phe
2
2
Paraffin
phe
2
2
Black
phe
35
35
Plasticizer
phe
4
4
Protective agent
phe
4.5
4.5
Accelerators
phe
1.5
1.5
Sulphur
phe
1.55
1.55
MDR rheometer, 160° C.:
ML
dNm
0.53
0.52
MH
dNm
9.52
8.37
Max-Min
dNm
8.99
7.85
tc(5)
min
2.13
2.25
tc(50)
min
3.32
3.72
tc(95)
min
7.67
8.15
Physical properties:
Hardness (Shore A)
48
49
Rebound
%
77
73
S c (22 h at 125° C.)
%
47
49
Stress at 50%
MPa
0.8
0.9
Stress at 100%
MPa
1.4
1.6
Stress at 200%
MPa
2.9
3.2
Stress at 300%
MPa
5.4
5.9
Stress at break
MPa
17.2
16
Standard deviation
MPa
0.9
0.9
Elongation at break
%
542
513
Standard deviation
%
22
21
Tear strength
N/mm
20.18
26.86
Standard deviation
N/mm
0.92
4.75
[0086] This table shows that there is a considerable improvement in the Delft tear strength, which is an indicator of better behaviour in fatigue (under repeated mechanical stressing) and without the other properties important for the application (S C and rebound) being modified. This is an improvement made to the crosslinked formulations, whether or not they have a thermoplastic processing mode.
[0087] In Table 2 below, the compounds were produced by the reverse method, that is to say, in the case of the first step, by firstly introducing all the additives and then the elastomers. The internal mixer was used at 30° C. with a rotor speed of 120 rpm. The working lasted about 7 minutes. The second step was similar to the procedure used for the NR. Scorch corresponds to premature vulcanization of a rubber compound.
[0000]
TABLE 2
A
C
D
E
EPDM (at 5% of
phe
175
175
175
175
ethylidene norbornene
(ENB))
Filler
phe
80
80
80
80
Plasticizer
phe
10
10
10
10
Additives
phe
6
6
6
6
Vulc. system S
phe
1.43
1.43
1.43
1.43
MBS1
phe
18
MBS2
phe
18
MBS3
phe
18
Mooney viscometer
100° C. viscosity
MU
61.5
67.3
67.8
66.9
Scorch, t5-125° C.
min
14.12
21.31
20.08
16.47
MDR rheometer, 170° C.
ML
dNm
1.37
1.55
1.33
1.49
MH
dNm
8.79
5.26
5.22
7.24
Max-Min
dNm
7.41
3.71
3.89
5.75
tc(5)
min
1.1
1.32
1.28
1.13
tc(50)
min
2.08
2.07
2.12
1.97
tc(95)
min
5.58
4.42
4.61
4.48
Physical properties:
Hardness (Shore A)
46
42
43
48
Rebound
%
65
60
60
63
S c (22 h at 125° C.)
%
52
53
51
50
Stress at 50%
MPa
0.7
0.7
0.7
0.7
Stress at 100%
MPa
1.3
0.8
0.9
1.2
Stress at 200%
MPa
3.2
1.7
2.1
2.7
Stress at 300%
MPa
5.7
2.9
3.5
4.5
Stress at break
MPa
19.5
10.9
12.5
11
Standard deviation
MPa
0.6
0.5
0.5
0.8
Elongation at break
%
693
875
798
617
Standard deviation
%
9
17
27
39
Tear strength
N/mm
22.02
22.09
23.57
23.13
Standard deviation
N/mm
0.29
0.38
0.28
0.41
[0088] These results show that, despite a reduction in the torque difference Max-Min, there is an improvement in the elongation and the Delft tear strength, this being important for fitting the part and for its resistance.
[0000]
TABLE 3
F
H
I
J
EPDM (10% ENB level)
phe
115
115
115
115
MBS1
phe
18
MBS2
phe
18
MBS3
phe
18
Filler
phe
78
78
78
63
Plasticizer
phe
15
15
15
12
Additives
phe
6
6
6
6
Vulc. system S
phe
3.6
3.6
3.6
3.6
Mooney viscometer
100° C. viscosity
MU
96.6
104.5
104.9
110.6
Scorch, t5-125° C.
min
9.93
15.22
13.42
13.03
MDR rheometer, 170° C.
ML
dNm
2
2.35
2.25
2.35
MH
dNm
27.09
12.53
12.47
20.18
Max-Min
dNm
25.08
10.18
10.23
17.83
tc(5)
min
0.88
1
0.98
1
tc(50)
min
1.57
1.7
1.55
1.68
tc(95)
min
4.23
4.88
3.75
3.73
Physical properties:
Hardness (Shore A)
66
62
63
68
Rebound
%
56
52
51
50
S c (22 h at 125° C.)
%
50
46
48
47
Stress at 50%
MPa
1.9
1.6
1.6
2.1
Stress at 100%
MPa
4
2.9
2.8
4.2
Stress at 200%
MPa
9.2
6.7
6.4
9.4
Stress at 300%
MPa
14.2
10.4
9.8
13.7
Stress at break
MPa
16.1
16.1
15.5
15.8
Standard deviation
MPa
1.5
0.6
0.8
0.9
Elongation at break
%
344
439
462
354
Standard deviation
%
36
17
15
22
Tear strength
N/mm
23.56
25.92
25.67
25.2
Standard deviation
N/mm
1.17
0.48
0.61
0.76
[0089] These results (Table 3) show that, despite a reduction in the torque difference Max-Min, there is an improvement in the elongation and the Delft tear strength, this being important for fitting the part and for its resistance.
[0000]
TABLE 4
A
D
EPDM
phe
100
100
PP
phe
50
50
Plasticizer
phe
30
30
Filler
phe
30
30
Peroxides
phe
4
4
Processing aids
phe
10.5
10.5
MBS1
phe
15
Physical properties:
Hardness (Shore A)
81
81
S c (22 h at 125° C.)
%
61
54
Stress at 50%
MPa
5.8
5.8
Stress at 100%
MPa
7.1
7.2
Stress at 200%
MPa
9.5
9.8
Stress at 300%
MPa
12
Stress at break
MPa
12.1
10.9
Standard deviation
MPa
0.4
0.2
Elongation at break
%
306
246
Standard deviation
%
9
6
Tear strength
N/mm
29.41
29.98
Standard deviation
N/mm
0.08
0.12
[0090] This Table 4 shows that the high-temperature compression set is improved.
[0000]
TABLE 5
Composition of the compounds
Composition
T0
T1
T2
T3
SBR Buna VSL 5525-1
103.12
103.12
103.12
103.12
1,4-cis BR
25
25
25
25
(Cariflex 1220)
1165 MP silica
80
80
80
80
Mobilsol K oil
4.38
4.38
4.38
4.38
B-grade white ZnO
2.5
2.5
2.5
2.5
Stearic acid
2.5
2.5
2.5
2.5
6PPD
2
2
2
2
Antilux 500
1.5
1.5
1.5
1.5
X50S silane
12.8
12.8
12.8
12.8
MBS
0
5
10
20
N300 black
2.4
2.4
2.4
2.4
Micronized sulphur,
1.4
1.4
1.4
1.4
300 mesh
CBS
1.7
1.7
1.7
1.7
DPG
2
2
2
2
[0091] Operating Method for Producing the Compounds:
[0092] All the ingredients were introduced at the start with the rubber, with the exception of the cure agents (sulphur, etc.). The compound was then mixed until it reached the temperature of 170° C. by self-heating. It was then cooled on a calendar and the cure agents were then added to it.
[0000]
TABLE 6
Rheometric properties at 170° C. (ISO 3417)
Min. torque
Max. torque
ts(2)
tc(90)
t(RH)
RH
Reference
ML (N · m)*
MH (N · m)*
(min, s)
(min, s)
(min, s)
(N · m)*
T0
1.66 (14.7)
7.93 (70.2)
2.23
15.06
4.26
0.037 (0.33)
T1
1.73 (15.3)
7.67 (67.9)
2.30
20.15
4.57
0.030 (0.27)
T2
1.75 (15.5)
7.74 (68.5)
2.41
21.43
5.09
0.028 (0.25)
T3
1.60 (14.2)
7.32 (64.8)
2.53
22.33
5.38
0.025 (0.22)
*values in brackets are in lb. inch.
[0000]
TABLE 7
Mooney viscosity index ML(1 + 4) at 100° C. (ISO 289-1)
T0
66
T1
68
T2
67
T3
65
[0000]
TABLE 8
135° C. precure test (ISO 289-2)
min.
t5 (min,
t35
t35-5
torque
RH
Reference
sec)
(min, sec)
(min, sec)
(N · m)*
(N · m)*
T0
13.18
19.46
6.28
6.45 (57.1)
0.008 (0.08)
T1
14.09
20.55
6.46
6.61 (58.5)
0.007 (0.07)
T2
14.46
21.45
6.59
6.63 (58.7)
0.007 (0.07)
T3
15.06
20.44
6.38
6.2 (56.8)
0.006 (0.06)
*values in brackets are in lb. inch.
[0000]
TABLE 9
170° C. cure time for sheets and test specimens
Reference
T0
T1
T2
T3
2-mm thick sheets (min, sec)
16
20
24
25
Goodrich blocks (min, sec)
18
22
26
29
[0000]
TABLE 10
Shore 1 hardness measurement (ISO 7619)
Reference
Instantaneous
after 15 seconds
T0
73
67.9 ± 0.5
T1
75
67.6 ± 0.2
T2
76
67.0 ± 0.3
T3
76
69.1 ± 0.3
[0000]
TABLE 11
Tensile properties (ISO 37)
Elongation
Tensile strength
at break
σ (50%)
σ (100%)
σ (200%)
σ (300%)
Ref.
(MPa)
(MPa)
(MPa)
(MPa)
(MPa)
(MPa)
σ 300 /σ 100
T0
20.2
404
1.55
2.72
7.50
13.9
5.1
T1
21.5
444
1.59
2.84
7.91
14.6
5.1
T2
22.6
472
1.62
2.55
7.01
13.4
5.25
T3
22.3
518
1.65
2.51
6.46
12.1
4.8
[0000]
TABLE 12
Tear strength (ISO 34-2)
Reference
Delft (N)
T0
46.6
T1
49.5
T2
54.3
T3
59.5
[0000]
TABLE 13
Dynamic viscoelastic characterization
Reference
E* (MPa)
E′ (MPa)
E″ (MPa)
tan δ
at 0° C.
T0
52.3
45.5
25.8
0.57
T1
52.5
46.3
24.7
0.53
T2
53.3
46.4
25.0
0.54
T3
54.5
47.6
24.0
0.50
at 70° C.
T0
16.0
15.8
2.1
0.14
T1
14.4
14.0
1.8
0.13
T2
16.7
16.4
2.7
0.17
T3
14.6
14.4
2.1
0.15
[0093] These examples show that by introducing the MBS in tyre formulations, the compositions are given an increase in their tear strength. This is an indication (under repeated mechanical stressing in use) of a reduction in crack propagation speed and better fatigue behaviour, without the other characteristics important for the application (hardness, tensile properties, dynamic viscoelastic properties) being modified. This is an improvement over the existing crosslinked formulations.
[0000]
TABLE 14
1
2
BR (Budene 1207G)
25.00
25.00
SSBR (VSL 5025-1HM)
75.00
75.00
MBS
10.00
IPPD
2.00
2.00
Budene 1207G
VSL 5025-1HM
Silica (Zeopol 8745)
65.00
65.00
Silane (Z6945)
10.40
10.40
Processing aid (Sundex 790 TN)
5.00
5.00
Stearic acid
1.00
1.00
Sulphur
1.40
1.40
Zinc oxide
2.50
2.50
Accelerator (CBS)
1.70
1.70
Accelerator (TMTD)
1.00
1.00
ML (dNm)
8.4
8.2
MH (dNm)
37.20
38
MH-ML (dNm)
29.80
29.80
ts2 (min)
0.75
0.80
tc90 (min)
1.61
1.84
Shore A (ASTM D 2240)
Hardness
65
67
Tests according to ASTM D 412, D 624)
Tensile strength* (MPa)
17.53 (2543)
16.63 (2412)
Elongation (%)
277 (277)
305 (305)
Stress 50% (MPa)*
2.38 (345)
3.31 (480)
Stress 100% (MPa)*
4.98 (722)
6.03 (875)
Stress 300% (MPa)*
6.65 (964)
9.73 (1412)
Tear strength $ (N · m)
28.70 (254)
35.59 (315)
*values in brackets are in psi;
$ values in brackets are in lb · inch.
[0094] It may be seen in these formulations (also used for manufacturing tyres) that again the incorporation of MBS significantly increases the tear strength, while at the same time, in this example, increasing the module. Again this provides a useful compromise of properties, limiting the deformation while reinforcing the composition. | The invention relates to is a crosslinked composition containing in parts by weight: 20 to 100 parts of at least one elastomer (I), 2 to 50 parts of at least one core/shell copolymer (II), and 0 to 100 parts of at least one thermoplastic polymer (III). The invention also relates to a method of producing one such crosslinked composition, which is characterized in that it consists in: mixing an elastomer and a core/shell copolymer optionally in the presence of: a grafted polyolefin, a plasticizer, fillers and/or additives, and a suitably-selected crosslinking system, and subsequently crosslinking said mixture at a suitable temperature. In a preferred embodiment of the invention, the mixture is crosslinked at a temperature of between 150 and 320° C. The invention method be carried out in an internal mixer, or, alternately, in a twin-screw extruder or a Buss®-type co-kneader. Depending on the case, the resulting mass is calendared or extruded, cooled and subsequently granulated. The granules thus obtained are then ready to be transformed, by means of heating, into sheets, plates, extrusions, tubes or other desired products. The invention further relates to the use of one such composition in the production of ducts, pipes, tubing, couplers or similar for conveying fluids, such as the fluid transfer conduits, pipes and other elements which are used in the automobile industry in braking, cooling, steering and air-conditioning systems. The inventive crosslinked composition can also be used in the production of belts, tires, electrical cable sheaths, and shoe soles.” | 2 |
CROSS-REFERENCE TO RELATED APPLICATION(S)
[0001] This application is based upon and claims the benefit of priority from U.S. Patent Application Ser. No. 60/760,588, filed on Jan. 20, 2006, the entire disclosure of which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates generally to optical imaging, and more particularly to a method, arrangement and system for performing optical imaging of scattering and phase phenomena in the mid-infrared (MIR) portion of the electromagnetic spectrum, e.g., with wavenumbers ranging from 600 cm −1 to 5000 cm −1 .
BACKGROUND INFORMATION
[0003] Gaining knowledge of biology at the molecular level may be one of the important challenges of the post-genomic era. While the development and application of fluorescent molecular probes may continue to provide the basis for many future advancements, there is a considerable need to address molecular characterization from an endogenous contrast alone. Endogenous-contrast molecular imaging may have the following exemplary advantages: a) it is non-destructive and generally does not alter the molecular composition of the specimen, b) specimen preparation is less substantial or nonexistent, c) knowledge of molecular structure is not required a priori, d) many unknown proteins/molecules may be studied simultaneously, e) biodistribution and delivery are not at issue, and f) techniques may be more easily translated to investigation and diagnosis of human tissues in vivo. Endogenous contrast approaches that determine structure, location, and function of molecules may therefore offer a clear window for observing natural biological processes.
[0004] Mid-infrared (MIR; 2 16 μm, 5000-600 cm-1) light may be preferable for endogenous chemical characterization since it can probe many native molecular vibrations simultaneously, with a high degree of specificity. To date, however, physical constraints and technological shortcomings may limit MIR molecular concentration sensitivities and imaging resolutions. Vibrational spectroscopies, including Raman and mid-infrared (e.g., MIR, 2-12 μm) are exemplary tools for an endogenous chemical characterization.
[0005] Studies have been conducted to investigate the potential of Fourier transform infrared (“FTIR”) spectroscopy and microscopy to obtain the chemical composition of proteins, biomembranes, cells, and diseased human tissue. However, MIR imaging remains a relatively unexplored area for biological samples and tissues for a number of reasons, some of which include: a) high absorption of water in mid-infrared, b) lack of high-resolution, high-sensitivity detectors and high-brightness sources that span the fingerprint regions, c) inadequate imaging optics, and d) complexity of biological spectra. One of the objects of the exemplary embodiments of the present invention is to leverage its signal-to-noise advantages for high-sensitivity molecular imaging and microscopy.
[0006] Accordingly, it may be beneficial to address and/or overcome at least some of the deficiencies described herein above.
SUMMARY OF THE INVENTION
[0007] The exemplary embodiments of the present invention can overcome the above-described impediments to the MIR imaging, e.g., by utilizing MIR spectral changes in refractive index to obtain chemical information from tissue or biological specimens. For example, exemplary embodiments of the present invention described herein below describe various exemplary methods, arrangements and systems (e.g., which can use the MIR technology) to achieve molecular characterization in unlabeled samples with higher spatial resolutions and at much lower molecular concentrations than previously thought to be possible. It may therefore provide the ability to perform, e.g., multiplexed, sub-cellular mapping of low concentration molecules in unlabeled and unaltered specimens.
[0008] The mainstay of mid-infrared analysis is absorption spectroscopy, which can provide information on molecular vibrations through measurements of wavelength-dependent attenuation of light. Absorption, however, is only one component of the complex index of refraction, the quantity that describes in detail the interaction of light with matter. However, techniques based on wavelength-dependent refractive index fluctuations have been relatively unexplored. Occurring in the vicinity of molecular absorption transitions, these rapid changes in refractive index can affect wavelength-dependent phase and scattering, which are in turn controlled by the molecular composition of the sample.
[0009] These optical phenomena may be probed in unlabeled specimens with highly sensitive mid-infrared phase and scattering measurement techniques. In so doing, detailed spectra of molecular species can be obtained in situ at much lower concentrations than any other method available today. When combined with certain techniques for improving the resolution of mid-infrared microspectroscopy, phase/scattering imaging may provide detailed sub-cellular maps of protein and metabolite composition. Since these mid-infrared signatures can be measured in a backscattering geometry, they may be obtained from thick tissue specimens, making endogenous-contrast molecular imaging in living animals and human patients possible.
[0010] Accordingly, exemplary systems and processes for generating information associated with at least one portion of a sample are provided. In one exemplary embodiment, at least one electromagnetic radiation can be received from the at least one portion, whereas the electro-magnetic radiation has a wavenumber that is between approximately 5,000 cm −1 and 600 cm −1 . The information can be generated which includes structural data, molecular data and/or chemical data of the portion. The information can be generated based on (a) at least one phase of the at least one electromagnetic radiation, and/or (b) at least one refractive index of the at least one portion. The above exemplary procedures can be provided by at least one arrangement.
[0011] In another exemplary embodiment of the present invention, the information can be generated based on at least one refractive index gradient of the portion. A wave guide arrangement (e.g., a mirror tunnel arrangement) can be provided which is adapted to transmit the electromagnetic radiation to the arrangement. The arrangement can include an interferometric arrangement (e.g., a common path interferometric arrangement) which may receive at least the electromagnetic radiation which can be based on a radiation received from a sample arm and a radiation received from a reference arm. The interferometric arrangement can utilize a multiple-beam interferometric arrangement and/or an active stabilization technique. The electromagnetic radiation can pass through the portion a plurality of times.
[0012] In yet another exemplary embodiment of the present invention, the arrangement can receives the electromagnetic radiation from a confocal microscopy arrangement, a spatial filter class, dark-ground, phase-contrast, and diffraction-contrast microscopy arrangement, a Nomarski or differential interference contrast microscopy arrangement, and/or a multi-focus radiative transport of intensity equation microscopy arrangement. An image of the at least one portion can be generated based on the information. The image can be generated using a computed tomography technique. The image can be a two-dimensional image and/or a three-dimensional image. The sample may include a biological sample. The biological sample can be an anatomical structure. At least one image of the at least one of the structural, molecular or chemical data of the portion can be generated based on at least one mathematical operation on one or more of data associated with one or more wave numbers.
[0013] According to another exemplary embodiment, the electromagnetic radiation having a first wavenumber can be transmitted to the portion which has at least two substances, whereas a refractive index of one of the substances at a second wavenumber is approximately the same as a refractive index of another one of the substances at the second wavenumber. The electro-magnetic radiation can be controlled such that the first wavenumber substantially matches the first wavenumber to reduce scattering within the portion.
[0014] Other features and advantages of the present invention will become apparent upon reading the following detailed description of embodiments of the invention, when taken in conjunction with the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Further objects, features and advantages of the present invention will become apparent from the following detailed description taken in conjunction with the accompanying figures showing illustrative embodiments of the present invention, in which:
[0016] FIG. 1 is a schematic diagram of an exemplary embodiment of a waveguide microscope;
[0017] FIG. 2 is a graph of exemplary absorption characteristics of a water substance (shown as a darker line) and a lipid-based substance (shown as a lighter line);
[0018] FIG. 3 is a graph of exemplary refractive index characteristics of a water substance (shown as a darker line) and a lipid-based substance (shown as a lighter line);
[0019] FIG. 4 is a schematic diagram of an exemplary embodiment of a MIR OCPM apparatus according to the present invention; and
[0020] FIG. 5 is a graph of an exemplary normalized scattering cross-section for a 1 μm lipid sphere immersed in water (e.g., determined using Mie theory).
[0021] Throughout the figures, the same reference numerals and characters, unless otherwise stated, are used to denote like features, elements, components or portions of the illustrated embodiments. Moreover, while the subject invention will now be described in detail with reference to the figures, it is done so in connection with the illustrative embodiments. It is intended that changes and modifications can be made to the described embodiments without departing from the true scope and spirit of the subject invention as defined by the appended claims.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0022] An exemplary embodiment of a system according to the present invention can utilize a light source irradiating a specimen with MIR light. The sample can absorb, scatter, transmit or reemit the light. According to one exemplary embodiment of the present invention, scattering of light from the specimen can be detected and analyzed. In another exemplary embodiment of the present invention, the phase of the light transmitted or remitted from the specimen can be detected. In a further exemplary embodiment of the present invention, the intensity of light as it is transmitted through or remitted by the specimen can be detected and analyzed.
[0023] The scattering, phase, and transmission of a specimen may be affected by the refractive index of the specimen or refractive index heterogeneities or refractive index gradients therein. MIR wavelengths may be selected or controlled or MIR spectroscopy may be conducted to probe these refractive index changes by measuring scattering, phase, and absorption. The refractive index changes are related to the molecular and chemical composition of the sample, and therefore, the measurement of phase, scattering, and transmission can provide this information. These measurements may be conducted using a microscopic instrument, providing high spatial resolution images of molecular composition, or may be conducted using a macroscopic instrument that measures a low-resolution image of the specimen or the bulk properties of the specimen.
[0024] Conventional implementations of MIR microscopy may be less beneficial since they generally have small fields of view and relatively low spatial resolutions. A variety of technical issues can be reviewed such as, e.g., a small number and large size of pixels available in HgCdTe focal plane arrays (FPA), a lack of accessible high-brightness sources, and a relatively low numerical aperture (NA<0.6) of MIR reflective objectives, some or all of which can make a wide-field sub-cellular imaging difficult. In order to address the challenges of full-slide digital histopathology imaging, another exemplary embodiment of the present invention can provide a wide-field microscopy technique to be utilized in devices and processes that can use a multi-mode rectangular waveguide or mirror tunnel 110 as the objective lens (shown in FIG. 1 )
[0025] FIG. 1 shows a schematic diagram of an exemplary embodiment of a waveguide microscope. For simplicity of presentation, only two mirrors are shown in FIG. 1 . However, it may be preferable to use three, four or more mirrors to fully confine the spatial modes in two-dimensions. Following an MIR illumination 100 of a specimen 120 , a diffracted light can propagate through the waveguide or mirror tunnel 110 . The lowest diffraction order can pass directly through the waveguide, whereas higher (n) orders may reflect off the mirrors n-times. If a lens 130 is placed at the output of the waveguide/mirror tunnel 110 , an array of images can be formed on the image plane 140 , where each successive image 150 of order (n=0,±1,±2 . . . ) can be formed from a spatially band passed version of the original image with low-pass cutoff <(n−1) and high-pass cutoff <(n) defined approximately by, e.g.,:
[0000]
α
(
n
)
=
k
sin
[
tan
-
1
[
(
2
n
+
1
)
d
2
L
]
]
.
[0000] where d is a distance 115 between the two mirrors 115 , L is a length 117 of the waveguide 110 and k is a wavenumber.
[0026] Following the detection of the amplitude and phase of each band passed image, the original image can be reconstructed at full-resolution by coherent addition of the band passed images. To mitigate cost and complexity, each band passed image can be deflected onto a single FPA, and its amplitude and phase can be obtained in a serial fashion. Using this exemplary technique, large field of view, megapixel images can be recreated on a 64×64 pixel FPA without moving the specimen. A resolution can also be improved as the mirror tunnel behaves like a diffraction-limited reflective objective lens with a NA nearly equal to the refractive index of the waveguide. When filled with water, the theoretical spatial resolution of the mirror tunnel ranges from ˜1.5-6.0 μm in the fingerprint region (3600 -800 cm −1 ), which is approximately a factor of four better than that of commercially available FPA infrared microscopes. As opposed to micro-Attenuated Total Reflection (“ATR”) microscopy, which provides comparable resolution, the water-filled mirror tunnel does not require specimen contact, and is therefore much more amenable to imaging live cells. If contact is permissible, the same principles of micro-ATR can be applied by constructing the mirror tunnel from a high-index waveguide (e.g. Germanium) to provide ˜0.5-2.0 μm spatial resolution throughout the fingerprint region.
[0027] Waveguide microscopy can be used for absorption spectroscopy at preferential spatial resolutions. While useful for determining functional groups, the amount of chemical information that can be obtained from absorption signatures may be limited in part by absorption signatures of dominant molecules, such as water, which tend to overwhelm the spectral contribution of molecules at lower concentrations. The inherent refractive index change that takes place at absorption fundamental wavelengths can be analyzed. This change in the refractive index may result in a phase or scattering modulation of the infrared signal at characteristic wavelengths corresponding to vibrational transitions (see graph of FIG. 5 ). Unlike absorption features, phase and scattering signatures can be more easily detected, since the unwanted background can be removed optically to reveal smaller molecular perturbations. Furthermore, the detected spectral features would likely be sharper, similar to derivative spectra. For visible microscopy, phase and scattering can be commonly exploited to image unstained samples by several conventional microscopy techniques, including, e.g.,: a) the spatial filter class: dark-ground, phase-contrast, and diffraction-contrast microscopy, b) Nomarski or differential interference contrast microscopy (“DIC”), and c) multi-focus radiative transport of intensity equation microscopy. When applied in the mid-infrared and in conjunction with waveguide microspectroscopy, these exemplary phase and scattering-sensitive techniques can enable imaging of endogenous, subcellular molecular features at lower concentrations than that possible by conventional MIR microspectroscopy methods.
[0028] The exemplary embodiments of the microscopies according to the present invention as described herein above may improve the sensitivity of endogenous molecular characterization by eliminating background, e.g., but for proteins and metabolites at very low concentrations, the phase and scattering perturbations may still be below the limits of direct detection. When applied in the mid-infrared, the exemplary embodiments of quantitative interferometric techniques according to the present invention—termed “optical coherence phase microscopy” (“OCPM”) herein—may allow endogenous imaging of phase changes induced by nanomolar concentrations of molecules in living cells. One exemplary variant of OCPM can use common-path interferometry to measure the electric field cross-correlation between a reflector above and a reflector below the sample (see FIG. 4 ). In the exemplary illustration of FIG. 4 , MIR light 400 irradiates a cell 420 positioned between two reflectors, i.e., reflector 1 410 and reflector 2 430 . MIR light 400 is reflected off the reflector 1 410 , the cell 420 , and the reflector 2 430 . Reflected light from the cell, e.g., the reflected light from the first reflector 415 and reflected light from the second reflector 425 are detected by a spectrometer. The spectrometer can detect the interference as a function of wavenumber. When the spectral interference of the returned light is measured, the phase relationship between the light transmitted through the sample and the reference light may be determined with extremely high precision, on the order of <0.1 μrad. If a 10 μm cell path length is considered, a refractive index change of 5×10 −9 can therefore be detectable by OCPM.
[0029] FIG. 2 shows a graph of exemplary absorption characteristics of a water substance (shown as a darker line 200 ) and a lipid-based substance (shown as a lighter line 210 ). FIG. 3 shows a graph of exemplary refractive index characteristics of a water substance (shown as a darker line 300 ) and a lipid-based substance (shown as a lighter line 310 ). In the exemplary graphs of FIGS. 2 and 3 , where the lipid absorption signature (CH 2 stretch) of the lipid-based substance 210 arises from approximately 0.5 molar oleic acid, a rapid refractive index fluctuation of the lipid-based substance 310 of ˜0.1 around 3.5 μm (2850 cm −1 ) can be seen. As a result, it is possible to detect ˜25 nmol oleic acid via the OCPM technique at this mid-infrared transition.
[0030] Further enhancements, including the use of 3-beam interferometry, multiply passing the specimen, high-power/brightness sources, or active stabilization techniques, could enable microscopic imaging with endogenous molecular sensitivities in the picomolar range. Mid-infrared OCPM can also be conducted in conjunction with waveguide microscopy (e.g., using the exemplary system/arrangement of FIG. 1 ) for a high-sensitivity imaging of subcellular proteins. The large field of view of the waveguide microscope opens up an additional possibility of using OCPM for endogenous, high-throughput detection of proteins on live cell and tissue microarrays.
[0031] The phase changes in the mid-IR may facilitate a better observation of molecular scattering in thick tissues. FIG. 5 shows a graph of an exemplary wavelength dependent normalized scattering cross-section (Q sca ) 505 for a 1 μm diameter lipid sphere in water. Certain features may be seen in this shown scattering spectrum. For example, optical scattering by this particle fluctuates by many orders of magnitude in the vicinity of water 500 and lipid 510 absorption peaks. The nature of this fluctuation is specific for a given solute and could form a basis for recovering the chemical composition of a thick tissue sample in back reflection. By using high-brightness sources and heterodyne interferometry, individual large organelles such as nuclei, mitochondria, vesicles, lysozomes, and mmolar concentrations of macromolecules may be detected, which may be important for a non-invasive optical diagnosis. This is substantiated supported by a recent report demonstrating information-rich, but as of yet, poorly understood FPA MIR images from tissue at 100-200 μm depths [see Wang et al., J. Biomed. Optics. 12:208 (2004)]. Further, at two distinct wavelengths in the mid-IR (3.04 μm 520 and 3.48 μm 530 ), the refractive index of lipid and water can equalize. At these index-crossing wavelengths, the normalized scattering cross-section approaches zero. Therefore, at these wavelengths, optical losses would likely be due to absorption alone. This phenomenon can be utilized in many ways, including, e.g., a) to construct images of individual molecular vibrations by subtracting images obtained at index-crossing wavelengths from images acquired at adjacent frequencies, and b) to conduct absorption tomography of water-based organisms (e.g., developing embryos) near the optical diffraction limit.
[0032] The foregoing merely illustrates the principles of the invention. Various modifications and alterations to the described embodiments will be apparent to those skilled in the art in view of the teachings herein. Indeed, the arrangements, systems and methods according to the exemplary embodiments of the present invention can be used with and/or implement any OCT system, OFDI system, SD-OCT system or other imaging systems, and for example with those described in International Patent Application PCT/US2004/029148, filed Sep. 8, 2004, U.S. patent application Ser. No. 11/266,779, filed Nov. 2, 2005, and U.S. patent application Ser. No. 10/501,276, filed Jul. 9, 2004, the disclosures of which are incorporated by reference herein in their entireties. It will thus be appreciated that those skilled in the art will be able to devise numerous systems, arrangements and methods which, although not explicitly shown or described herein, embody the principles of the invention and are thus within the spirit and scope of the present invention. In addition, to the extent that the prior art knowledge has not been explicitly incorporated by reference herein above, it is explicitly being incorporated herein in its entirety. All publications referenced herein above are incorporated herein by reference in their entireties. | Exemplary systems and processes for generating information associated with at least one portion of a sample are provided. In one exemplary embodiment, at least one electromagnetic radiation can be received from the at least one portion, whereas the electromagnetic radiation has a wavenumber that is between approximately 5,000 cm −1 and 600 cm −1 . The information can be generated which includes structural data, molecular data and/or chemical data of the portion. The information can be generated based on (a) at least one phase of the at least one electromagnetic radiation, and/or (b) at least one refractive index of the at least one portion. According to another exemplary embodiment, the electromagnetic radiation having a first wavenumber can be transmitted to the portion which has at least two substances, whereas a refractive index of one of the substances at a second wavenumber is approximately the same as a refractive index of another one of the substances at the second wavenumber. The electromagnetic radiation can be controlled such that the first wavenumber substantially matches the first wavenumber to reduce scattering within the portion. | 6 |
RELATED APPLICATIONS
This application claims the benefit of the filing date of a provisional application with Ser. No. 61/305,289 which was filed on Feb. 17, 2010, the disclosure of which is incorporated herein by reference.
TECHNICAL FIELD
The disclosed subject matter is directed to the production of pre-cast blocks for constructing modular columns.
BACKGROUND
Decorative stone columns are widely used by homeowners and businesses for a variety of purposes such as the monuments at the entrance of a driveway, as supports between fence sections, as a base for a statue, and as pillars at the entrance to a building to name just a few uses. The construction of decorative stone columns normally requires the services of a skilled mason and the utilization of specialized masonry tools. The average individual does not typically have the necessary tools or requisite skill for constructing appropriate concrete forms or for completing decorative stone column construction. As a result, most decorative stone columns are usually constructed by a skilled mason and at a high cost. Producing a high quality, durable and aesthetically pleasing column at a reasonable cost can be accomplished with the assistance of modular column construction as is outlined below.
SUMMARY
The present invention pertains to the construction of a decorative column and the method of producing the modular blocks that comprise the decorative column. The column comprises a rigid center post surrounded by a plurality of modular blocks. Each modular block has a hole extending through it so the block can fit onto the rigid center post and remain fixed in place on the post. Each modular block is stackable upon another block of similar construction. The present invention pertains to a method for not only producing the modular blocks with compressible inserts but also the erecting of a decorative column that is capable of accommodating ground heaving due to freezing temperatures and thermal expansion which is particularly important, for example, when the column is utilized to support fence sections.
The method comprises the steps of producing a flexible mold for forming the modular blocks, positioning a compressible insert into the mold, filling the open area created by the walls of the mold and the exterior surfaces of the compressible insert with a lightweight cementitious material, waiting for the cementitious material to cure and then removing the modular block from the flexible mold.
Once the modular blocks with the compressible inserts are removed from the mold they are positioned onto the rigid center post so that the compressible insert center opening is aligned with the rigid post and can slide down the post to either the ground or atop another modular block. The process of placing the modular blocks on the center post can be repeated as necessary to produce a decorative column of the desired height.
The compressible inserts are instrumental in reducing the weight of the modular blocks as the inserts are preferably comprised of materials such as EPS foam or cellular PVC to name but a few available options. In addition, the compressible inserts facilitate placement of the modular blocks on the rigid center post particularly for posts of a substantial height as the compressible and flexible material will not bind against the post as the blocks are lowered into position on the post.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a perspective view of a three rail fence constructed with modular columns;
FIG. 2 is a perspective view of a panel fence constructed with modular columns;
FIG. 3 is a perspective view of a center post of a modular column being constructed with pre-cast ornamental blocks;
FIG. 4 is a plan view of an embodiment of a pre-cast block without side slots utilized in a modular column;
FIG. 5 is a plan view of an embodiment of a pre-cast block with single dimension side slots utilized in a modular column;
FIG. 6 is a plan view of an embodiment of a block with dual dimension side slots utilized in a modular column;
FIG. 7 is a plan view of an embodiment of a block with single dimension side slots utilized in a modular column;
FIG. 8 is a cross sectional view of FIG. 2 revealing the interior features of a modular column;
FIG. 9 is a perspective view of an empty mold with a center post for forming a block for use in a modular column;
FIG. 10 is a perspective view of a mold showing a compressible insert surrounding the center post used for forming a block for use in a modular column;
FIG. 11 is a perspective view of a mold showing the addition of a cementitious material to the open area of the mold for forming a block for use in a modular column; and
FIG. 12 is a perspective view of a mold showing the cementitious material leveled at the top of the mold for purposes of forming a block for use in a decorative modular column.
DETAILED DESCRIPTION
Referring now to the drawings wherein like reference numerals refer to similar of identical parts throughout the several views. FIG. 1 reveals a fence section comprised of two modular columns 10 connected by fence rails 54 . FIG. 3 details the process by which a modular block 58 is lowered being lowered into position over a post 12 onto several pre-cast blocks 14 , 16 , 18 already in position. Pre-cast blocks can be used to efficiently and with high aesthetic appeal produce columns 10 for various embodiments of a rail fence such as seen in FIG. 1 as well as for various embodiments of a panel fence such as seen in FIG. 2 . Numerous other embodiments and uses of columns utilizing this modular pre-cast block technology are also contemplated and are only limited by the imagination.
The production of a pre-cast block 58 begins with the use of a flexible mold 20 such as one produced from silicone and as depicted in FIG. 9 . The mold 20 includes four sides 22 A, B, C and D a center post 24 as well as textured interior walls 26 . The textured interior walls 26 are intended to replicate on the finished modular block a stone face including a desirable and contrasting coloration. Prior to the addition of any cementitious material into the mold 20 the textured interior walls are coated with a coloration mixture of mineral iron oxides, cement, water and an acrylic modifier. The coating is applied consistent with the stone facing molded into the interior walls 26 so as to give the impression that the stone faces are of varying color as might be created by a mason using natural stone. Varying the mineral iron oxides content allows different colors to be formulated to satisfy customer preferences. This coloration mixture may be hand applied to specified portions of the interior wall. Alternatively, automated techniques may also be employed such as the use of robotic systems to apply the coloration mixture.
Once the subset of the textured interior walls 26 are coated with the above referenced mixture a compressible insert 28 is positioned over the center post 24 as shown in FIG. 10 . The compressible insert 28 is lightweight, and preferably comprised of materials such as EPS foam or cellular PVC. The insert 28 includes an upper surface 32 , and creates an interior space 33 that will prevent the intrusion of cementitious material and also includes a plurality of exterior walls 34 . The insert upper surface 32 is preferably at the same elevation and not above the upper surface 36 of the textured interior walls 26 .
Once the compressible insert 28 is secured in position over the center post 24 , the open space 38 between the mold walls 26 and the exterior walls 34 of the compressible insert 28 is filled with a cementitious material 40 as seen in FIG. 11 . The cementitious material 40 is preferably a light weight wet cement that readily flows to fill the open space 38 . An exemplary mixture of cementitious material would comprise an expanded slate lightweight concrete, such as Stalite™, a dry pigment, aggregates and water combined to form a flowable, lightweight mixture.
Once the open space 38 is completely filled the mold 20 is vibrated to remove voids from the cementitious material 40 , allow for settling and to facilitate the movement of the coloration mixture painted onto the mold interior walls 26 into the cementitious material 40 instead of remaining at the surface thereby giving a three dimensional penetration of the coloration mixture into the block and improving the weatherability of the block's surface coloration. In addition, as best seen in FIG. 12 , the cementitious material 40 is leveled at the upper surface 36 to create a smooth even surface that facilitates the stackability of the blocks when the cement is cured.
In about twelve hours the cementitious material is fully cured and the block, along with the compressible insert, can be removed from the mold 20 . Manipulation of the flexible mold 20 , either manually by overturning the mold and popping out the block as is well known in the art, or by injection of air into an orifice in the mold bottom effectively inverting the silicone mold, will facilitate release of the block from the mold 20 . Because the cementitious material 40 permeates the pores of the exterior walls 34 of the compressible insert 28 , the insert is securely bound to the cementitious material and will not separate during use.
As seen in FIGS. 4 through 7 , alternative embodiments of the block may be cast in the mold 20 with or without slots. FIG. 4 reveals a standard block 42 without slots that would properly be employed, for example, as shown at the lowermost block 18 in the column in FIG. 3 . This lowermost slotless block 18 would typically be employed in a column utilizing between one and four fence rails, such as exemplified in FIG. 1 .
An alternative block embodiment as depicted in FIG. 5 reveals a block 50 with slots 52 on opposed sides of the compressible insert 28 . These opposing slots 52 serve to hold rails 54 in position as is best seen in FIG. 1 . FIG. 3 also serves to highlight how the slot 52 of block 58 integrates with the slot and block 14 positioned immediately below it in the column to create an opening for securing the rail 54 in position. It will be readily apparent to one versed in the construction of columns that the placement of the slots 52 in a modular block 10 may be offset by 90 degrees, instead of 180 degrees, should a block be needed for a corner column with fence rails extending outwardly at 90 degrees instead of 180 degrees. In addition, a block may have only a single slot 52 should a column be needed that is adjacent a building or other structure and the rails need only extend in a single direction.
FIG. 6 depicts a third embodiment of a block 60 that is utilized in the construction of a panel fence such as that shown in FIG. 2 . The narrower and shorter slot 62 serves to secure in place the edge of the entire height of the fence panel 67 . The configuration of this slot 62 can also be viewed in cross section in FIG. 8 which shows four separate blocks 61 A, 61 B, 61 C and 61 D positioned at the top of the column. Block 61 A serves as a capping block and includes no slots since the fence panel does not extend upwardly to that height. Block 61 B includes an upper exterior surface 65 with no slot and a lower portion with a slot 64 . The slot 64 on block 61 B, in conjunction with slot 64 in block 61 C serves to secure one end of the upper rail 66 , as best seen in FIG. 2 , in position within the column. Block 61 C also includes a small slot 62 that is intended to facilitate securing the top portion of the panel 67 in position. Finally, block 61 D includes only a small slot 62 but no larger slot 64 , such as that depicted in FIG. 7 . The configuration of block 61 D is repeated on blocks lower in the column until reaching the lower rail 68 where a similar configuration of blocks is utilized to support the rail 68 and the panel 67 as seen at the top of the column with blocks 61 B and 61 C. The dimensions of the slots 62 , 64 may be tailored to any preferred dimension during production to suit the specific dimensions of the fence rails 66 , 68 and panels 67 that are being utilized. To produce slots of the desired dimension one or more inserts are positioned within the mold prior to introduction of the cementitious material 40 or the molds may have the inserts already included. Whether specifically designed into the mold for purpose of occluding the presence of the cementitious material or removable inserts are positioned within the mold 20 , once the cementitious material 40 has been cured the slots are formed into the finished block and they are ready for column construction.
The various embodiments of the present invention may be utilized to create a structurally sound and aesthetically pleasing column that can stand alone or be incorporated into a fence of a wide range of configurations including rail fences or panel fences. The use of pre-cast blocks 58 with their aesthetically pleasing exterior surfaces, preconfigured slots and lightweight but structurally rigid material greatly facilitates the construction of the columns. Turning again to FIG. 3 , a rigid center post 12 is placed into the ground or secured by some other means so that it stands in a substantially vertical orientation. The center post 12 is preferably a vinyl composition post because of its resistance to weathering and insects, but may be of any sturdy material such as wood, metal or concrete. Additionally, the center post 12 can be of a wide range of dimensions such as 5 inches square or 3 inches square. Alternatively a rectangular of circular configuration for the rigid center post 12 also may be employed. The center post 12 must, however, be of only slightly lesser dimensions than the hole dimension of the compressible insert 28 so that proper alignment of the pre-cast blocks on the modular column 10 can be accomplished.
As seen in FIG. 3 , once the center post 12 is secured in a substantially vertical orientation, the central opening 33 of the pre-cast block's 58 compressible insert 28 is aligned over the center post 12 . The first pre-cast block 18 to be installed is then moved onto the lowermost support surface which will either typically be a ground surface or a prepared level surface such as concrete. The process of placing additional pre-cast blocks on the column is greatly simplified with the use of a compressible insert 28 . The compressible insert material is soft and pliable and therefore will not bind against the center post 12 because of interference between the insert 28 and the post 12 . Moreover, as noted above, because of the light weight of the compressible insert and the fact that it occupies a significant percentage of the block interior volume that otherwise would be occupied by cementitious material 40 the pre-cast block weighs far less than a pre-cast block constructed without a compressible insert 28 . The nominal weight of a pre-cast block greatly facilitates the construction of a decorative modular column as placement of a pre-cast block with a compressible insert onto a center post 12 requires lesser physical exertion than installation of blocks comprised entirely of cementitious material 40 .
As further seen in FIG. 3 , a multitude of modular blocks 14 , 16 , 18 , 58 may be placed onto the rigid center post 12 to create a decorative column of any desired height depending upon how the columns is to be employed, for example, as a fence post, a support column or a mailbox stand. If building a fence rail column then, as previously discussed, slots 52 , 62 , 64 may be configured to satisfy the dimensional requirements of the fence rails and panels. Advantageously, no mortar need be placed between the pre-cast blocks to secure them in position as the blocks simply reside one atop the other creating a seamless textured stone exterior along the entire length of the column. Also advantageously, the compressible insert 28 greatly facilitates the resiliency and longevity of the decorative column 12 in areas where there is heaving of the ground due to the freeze-thaw cycle. Because of these compressible inserts 28 , the pre-cast blocks can float on the center post 12 thereby avoiding the accumulation of tensile and compressive forces that can readily fracture hand crafted stone columns or even those with pre-cast blocks that are mortared and locked into fixed positions. For stone columns, such as those shown in FIG. 1 , that are employed as fence columns, the thermal expansion of the fencing segments can produce significant lateral loads on the stone columns that can be absorbed by the compressible inserts 28 thereby avoiding damage to the stone columns through cracking of the column materials.
Those skilled in the art appreciate that variations from the specified embodiments disclosed above are contemplated herein and that the described embodiments are not limiting. The description should not be restricted to the above embodiments, but should be measured by the following claims. | A decorative column comprising a rigid center post, a plurality of pre-cast pieces with each piece having a hole extending therethrough so the pre-cast piece slides onto the center post and remains in place on the center post. Each pre-cast piece being stacked upon another pre-cast piece, the pre-cast pieces being of a predefined shape, and a compressible center core liner filling a portion of the hole of the pre-cast piece. The compressible center core including a cutout shape consistent with the cross sectional shape of the rigid center post thereby allowing passage of the center post through the compressible center core. | 4 |
RELATED APPLICATIONS
This application is a national stage entry under 35 U.S.C. § 371 of PCT/IN03/00043, filed Mar., 3, 2003.
FIELD OF THE INVENTION
The present invention relates to novel polymorphic forms of quetiapine fumarate, processes for their preparation and pharmaceutical compositions containing them.
BACKGROUND OF THE INVENTION
2-[2-(4-Dibenzo[b,f]-[1,4]thiazepin-11-yl-1-piperazinyl)ethoxy]ethanol (quetiapine) and its salts were disclosed in Eur. Pat. No. 0240228 and they are useful for their antidopaminergic activity, for example, as an antipsychotic or neuroleptic.
Various processes for preparation of quetiapine and 2-[2-(4-Dibenzo[b,f]-[1,4]thiazepin-11-yl-1-piperazinyl)ethoxy]ethanol hemifumarate (quetiapine fumarate) were described in EP 0240 228, EP 0282236, WO 01/55125 and WO 99/06381. According to the teachings of literature, quetiapine fumarate was crystallized from ethanolic solution containing quetiapine free base and fumaric acid. Quetiapine fumarate prepared according this method fails to produce well defined reproducible crystalline form.
It has now been discovered stable, reproducible two crystalline forms of quetiapine fumarate. It has also been discovered that the crystalline forms of quetiapine fumarate can be obtained in very pure state. Thus, they can be used as active ingredients in pharmaceutical preparations.
Thus, the object of the present invention is to provide quetiapine fumarate in stable and reproducible crystalline forms, processes for their preparation and pharmaceutical composition containing them.
The present invention also provides amorphous form of quetiapine with adequate stability and good dissolution properties.
Thus another object of the present invention is to provide amorphous form of quetiapine fumarate, a process for preparing it and a pharmaceutical composition containing it.
DETAILED DESCRIPTION OF THE INVENTION
The present invention provides a novel crystalline form of quetiapine fumarate, which is designated as form I. Quetiapine fumarate crystalline Form I is characterized by x-ray powder diffraction pattern having significant reflections expressed as 2θ values at about 7.3, 9.2, 11.6, 13.3, 14.4, 14.8, 15.3, 15.9, 16.2, 16.7, 17.6, 19.1, 19.7, 20.1, 20.8, 21.1, 21.8, 22.3, 23.4, 24.3, 24.7, 25.1, 25.6, 27.1, 28.5, 29.5, 33.2, 40.4 deg.
x-Ray powder diffractogram of quetiapine fumarate crystalline Form I is shown in FIG. 1 . The major peaks and their intensities of x-ray powder diffractogram are shown in Table 1. The intensities of the reflections are expressed as percent of most intense reflection.
A further aspect of the present invention provides a process for the preparation of quetiapine fumarate crystalline Form I.
Quetiapine fumarate crystalline Form I is prepared by dissolving quetiapine free base and fumaric acid in a suitable solvent and crystallizing fumarate salt. This crystallization from the suitable solvent is an effective method of removing impurities.
A further aspect of the present invention thus provides quetiapine fumarate crystalline Form I which is substantially pure, for example at least 98% preferably at least 99%, more preferably at least 99.5% pure.
Preferably molar ratio of quetiapine free base to fumaric acid is between about 1:0.4 to about 1:1.
The suitable solvents are ketones like acetone, methyl iso butyl ketone; esters like ethyl acetate, ethyl formate, methyl acetate; and mixture thereof.
The preparation of quetiapine free base is described, for example in EP 0240228.
Crystallization of quetiapine fumarate from solution may be initiated by conventional means such as addition of a non-solvent, evaporation of solvent, cooling or seeding the solution.
The present invention also provides another novel crystalline form of quetiapine fumarate, which is designated as Form II. Quetiapine fumarate crystalline Form II is characterized by x-ray powder diffraction pattern having significant reflections expressed as 2θ values at about 4.9, 7.4, 9.2, 11.7, 13.4, 14.4, 14.9, 15.4, 15.9, 16.3, 16.7, 17.7, 18.6, 19.8, 20.2, 20.8, 21.2, 21.9, 22.4, 22.9, 23.4, 24.3, 24.7, 25.2, 25.7, 26.9, 27.8, 28.8, 29.4, 33.2, 35.9, 38.0, 38.7, 39.9, 42.8 deg.
x-Ray powder diffractogram of quetiapine fumarate Form II is shown in FIG. 2 . The major peaks and their intensities of x-ray powder diffractogram are shown in table 2. The intensities of the peaks are expressed as percent of most intense reflection.
A further aspect of the present invention provides a process for the preparation of quetiapine fumarte Form II.
Quetiapine fumarate crystalline Form II is prepared by dissolving quetiapine free base in methyl tert. butyl ether, heating to reflux, adding fumaric acid at reflux, maintaining at reflux for about 30 minutes to about 1 hour, cooling to 20–30° C., maintaining for about 30 minutes with or without stirring, optionally seeding with quetiapine fumarate crystalline Form II, filtering and washing the crystals formed with methyl tert. butyl ether.
Preferably molar ratio of quetiapine free base to fumaric acid is between about 1:0.4 to about 1:1.
The present invention also provides a novel amorphous form of quetiapine fumarate, which is designated as amorphous quetiapine fumarate. The amorphous quetiapine fumarate is characterized by having broad x-ray diffraction maximum expressed as 2θ between about 10 and about 30 deg.
A further aspect of the present invention provides a process for the preparation of amorphous quetiapine fumarate. Amorphous quetiapine fumarate may be prepared by dissolving quetiapine fumarate in a solvent mixture, removing the solvent from the solution. Quetiapine fumarate crystalline Form I or Form II, which are obtained as described herein above, or quetiapine fumarate obtained by previously known methods may be used for the preparation of amorphous quetiapine fumarate.
The solvent mixture comprises chloroform and methanol in a ratio between about 1:0.5 and 1:2 volume/volume, preferably in the ratio of 1:1 volume/volume. The solvent can be removed form the solution by techniques such as vacuum drying or spray drying.
A further aspect of the present invention provides a pharmaceutical composition comprising an effective amount of quetiapine fumarate polymorphic form and a pharmaceutically acceptable carrier.
The quetiapine fumarate polymorphic forms include quetiapine fumarate crystalline Form I, quetiapine fumarate crystalline Form II and amorphous quetiapine fumarate.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is x-ray powder diffraction pattern of quetiapine fumarate crystalline Form I.
FIG. 2 is x-ray powder diffraction pattern of quetiapine fumarate crystalline Form II.
FIG. 3 is x-ray powder diffractogram of amorphous quetiapine fumarate.
The x-ray powder diffraction spectra was measured on a Siemens D-5000 diffractometer.
TABLE 1
2θ (degree)
% Intensity
7.3
30.4
9.2
39.9
11.6
39.3
13.3
33.1
14.4
12.9
14.8
27.1
15.3
42.2
15.9
16.8
16.2
83.3
16.7
39.0
17.6
41.6
19.1
13.4
19.7
48.1
20.1
100.0
20.8
30.8
21.1
91.8
21.8
43.3
22.3
57.2
23.4
57.2
24.3
21.7
24.7
13.8
25.1
32.6
25.6
28.9
27.1
13.7
28.5
20.4
29.5
13.0
33.2
26.3
40.4
13.0
TABLE 2
2θ (degree)
% Intensity
4.9
9.9
7.4
24.0
9.2
41.0
11.7
37.7
13.4
25.5
14.4
22.2
14.9
32.0
15.4
33.2
15.9
25.2
16.3
52.5
16.7
36.4
17.7
28.4
18.6
22.3
19.8
53.1
20.2
82.2
20.8
24.7
21.2
77.3
21.9
41.8
22.4
43.6
22.9
100.0
23.4
49.5
24.3
20.2
24.7
20.4
25.2
24.7
25.7
38.5
26.9
25.4
27.8
20.2
28.8
80.8
29.4
53.2
33.2
23.8
35.9
11.8
38.0
28.7
38.7
24.9
39.9
13.8
42.8
14.3
The following examples are presented for illustrative purposes only and are not intended as a restriction on the scope of the invention.
EXAMPLE 1
Quetiapine free base (5 gm) obtained by the process described in EP 0240228 (example 1) is dissolved in acetone (60 ml). To this solution, fumaric acid (0.9 gm) is added and then heated for complete dissolution. The solution is cooled to 20 to 25° C. and maintained for 1 hour. The product obtained is filtered washed with acetone and dried to give 4.9 gm of quetiapine fumarate Form I. (HPLC purity: 99.8%).
EXAMPLE 2
Example 1 is repeated using 60 ml ethyl acetate instead of acetone. Yield of quetiapine fumarate Form I is 5.2 gm (HPLC purity: 99.6%).
EXAMPLE 3
Example 1 is repeated by seeding the solution with quetiapine fumarate Form 1 during maintenance at 20 to 25° C. Yield of quetiapine fumarate Form I is 5.2 gm (HPLC purity: 99.8%).
EXAMPLE 4
Quetiapine free base (10 gm), obtained by the process described in example 1 of EP 0240228 is dissolved in methyl tert. butyl ether (100 ml). The solution is heated to reflux and fumaric acid (1.5 gm) is added at reflux. The refluxing is continued for 45 minutes, cooled to 20–25° C. and stirred for 30 minutes. The resulting crystals are filtered washed with methyl tert. butyl ether and dried to give 19.2 gm of quetiapine fumarate Form II.
EXAMPLE 5
Example 4 is repeated by seeding the contents during maintenance at 20 to 25° C. with quetiapine fumarate Form II. The yield of quetiapine fumarate Form II is 19.5 gm.
EXAMPLE 6
Quetiapine fumarate (2 gm) obtained by the process described in example 4 of EP 0240228 added to a solvent mixture containing methanol (10 ml) and chloroform (10 ml). The contents are heated to 40–45° C. for dissolution and the clear solution is subjected to vacuum drying at 35–40° C. for 15 to 20 hours to give 1.9 gm of amorphous quetiapine fumarate.
EXAMPLE 7
Example 6 is repeated using quetiapine fumarate Form I instead of quetiapine fumarate. The yield of amorphous quetiapine fumarate is 1.8 gm.
EXAMPLE 8
Example 6 is repeated by subjecting the clear solution to spray drying instead of vacuum drying to give 1.8 gm of amorphous quetiapine fumarate. | The present invention relates to novel polymorphic forms of quetiapine fumarate, processes for their preparation and pharmaceutical compositions containing them. | 2 |
FIELD OF THE INVENTION
The present invention relates generally to detecting surface characteristics of a sample surface, and more particularly to continuous detecting of surface characteristics of a moving sample surface.
BACKGROUND OF THE INVENTION
During the paper making process water, refined pulp and other additives are combined to give the finished paper the desired properties. The mix is spread over a mesh screen which forms the paper and lets the water be extracted. The paper then travels through different processes and machines designed to remove the water from the paper. After the paper is dry, the paper is run between drums to give the desired smoothness. This process may be referred to as calendering the paper. The more times paper is calendered the less bulk it has but the smoother the finish of the paper. To create glossy paper, uncoated paper may be coated with a paint-like product and buffed by rollers under very high pressure, to create a shiny appearance. This process may be referred to as supercalendering. Additional varnish layers may be applied to paper during the printing process to provide a gloss surface on the paper. The gloss surface may also protect the paper from the surrounding environment. During the various manufacturing process a continuous roll of paper weaves throughout the machinery of the press. Rolls and presses are used to move the paper between the various manufacturing processes.
To ensure that the paper surface has received the correct amount of gloss, sensors are used to measure the gloss of sample surfaces. Referring to FIG. 1A , sensor 100 A may have a light source 102 A for providing a light beam 104 A to illuminate sample surface 106 A at a pass-line. Light beam 104 A is reflected off sample surface 106 A. The intensity of the reflected light is measured with light detector 108 A. The reflected light is measured by light detecting surface 110 A of light detector 108 A to determine the light intensity of the reflected light. The gloss level is calculated by determining the ratio of the reflecting light beam intensity to the intensity of the illuminating light beam. The intensities of the reflected light are compared with known values of intensity for various gloss sample surfaces.
Referring to FIG. 1B , as the paper moves along the manufacturing process, sample surface 106 B of a web of paper may flutter or wave due to vibrations imparted by the devices, applicators, and other machinery used in the manufacturing process. The flutter or wave may cause the sample surface 106 B to move to a new sample surface location 112 B. The movement of the sample surface 106 B may cause errors to the measured gloss values because the optical arrangement of the gloss sensor system may require a very precise geometry in order to operate in a correct manner.
Referring to FIG. 1C , as the paper moves along the manufacturing process, the sample surface 106 C of the web of paper may tilt and/or cup due to shifts in the web of paper in both lateral and longitudinal directions. The tilt may cause the sample surface 106 C to shift to a new sample surface angle 112 C. This may be problematic with on-line measurement applications. The tilt of the sample surface 106 C may cause errors to the measured gloss values. The erratic sensor response is caused by the optical arrangement of the gloss measurement. The optics may require a very precise geometry. The light source 102 C may reflect the light beam 104 C off the sample surface 106 C exactly onto the light detecting surface 108 C of the light detector 110 C.
If sample surface 106 B, 106 C moves or tilts, some part of the reflected light rays may be lost and the measured signal will be erratic. The current state of the art may provide for precise measurements in a laboratory setting when the sample position can be easily controlled but, as explained above, such control is not easily obtained in a manufacturing environment.
In paper and board manufacturing, non-touching measurement principles may be preferred over sensor techniques that make contact with the paper web. In addition, paper web stabilization techniques such as mechanical sheet stabilizers are also not preferred. For example, the use of mechanical sheet stabilizers can cause scoring on the product surface. Due to such markings, it may be impossible to use sheet stabilizers in certain applications. Also, sheet stabilizers may tend to increase dust and dirt problems by rubbing the moving web. The cross-direction profiles of paper and board webs can have many types of deviations from a straight line. For example, the base cross profile can be warped in many different directions. Because warping or scoring of paper the optimal position of the paper web for on-line gloss measurement is very difficult and sometimes impossible to guarantee.
Accordingly, an efficient and effective device, method, and system is needed for detecting surface characteristics of a sample surface. In addition, the system and method may provide for detecting surface characteristics of a moving sample surface.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to provide devices, systems, and methods for detecting surface characteristics of a sample surface at a tilt where the surface is stable or moving. According to an exemplary embodiment of the present invention, the device may have a conveying device for moving a sample surface. The device may also have a light source for reflecting a beam of light off the sample surface and a light detector with a light detection surface for continuous light detection. A lens may be used for receiving the beam of light reflected from the sample surface and focusing the beam of light on the light detection surface of the light detector. The area of the beam of light prior to the lens may be unequal to an area of a lens receiving surface. A reference analyzer may determine the optical properties of the analyzed surface based on a comparison of the reflected light received with known reflected light values for known sample surfaces.
In an alternate embodiment, the area of the focused beam of light may be larger than the area of the light detection surface and the reference analyzer comparison may be based on the area of the detection surface. In another embodiment, the area of the focused beam of light may be smaller than the area of the light detection surface and the reference analyzer comparison may be based on the area of the focused beam of light prior to the lens. In another embodiment, the reference analyzer may determine the gloss, the deviation of gloss, the sparkle spot size, or the number of spot sizes. In another embodiment, the light detector may be a Charge Coupled Device (CCD) camera., Charge Coupled Device (CCD) array, Complementary Metal Oxide Semiconductor (CMOS) camera, Complementary Metal Oxide Semiconductor (CMOS) array, photodiode array or photodiode. In yet another embodiment, the sample surface may be the surface of a moving web of paper. In yet another embodiment, the reference analyzer may compare the intensity of reflected light received with known intensity reflected light values of known sample surfaces.
According to an exemplary embodiment of the present invention, the method may involve the following steps. The sample surface may be conveyed along a mechanized process at a tilt. A beam of light is emitted onto the sample surface and reflected off the sample surface. The beam of light reflected from the sample surface is focused onto a light detection surface of a light detector. The area of the beam of light prior to the lens is unequal to an area of a lens receiving surface. The beam of light is focused by the lens onto the light detection surface of the light detector continuously. The optical surface is determined based on a comparison of the reflected beam of light received with known reflected light values for known sample surfaces.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objectives and advantages of the present invention will be apparent upon consideration of the following detailed description, taken in conjunction with the accompanying drawings, in which like reference numbers refer to like parts throughout, and in which:
FIG. 1A is a generalized schematic of a prior art gloss sensor.
FIG. 1B is a generalized schematic of a prior art gloss sensor with flutters and waves of the sample surface at the pass-line.
FIG. 1C is a generalized schematic of a prior art gloss sensor with tilt of the sample surface at the pass-line.
FIG. 2A is a generalized schematic of a sensor used to implement the exemplary light source embodiment of the present invention.
FIG. 2B is a generalized schematic of a sensor used to implement the exemplary light source embodiment of the present invention with flutters and waves of the sample surface at the pass-line.
FIG. 2C is a generalized schematic of a sensor used to implement the exemplary light source embodiment of the present invention with a tilted sample surface at the pass-line.
FIG. 3 is a flow chart illustrating an exemplary method for the sensor used to implement the light source embodiment of the present invention.
FIG. 4A is a generalized schematic of a sensor used to implement the exemplary light detector embodiment of the present invention.
FIG. 4B is a generalized schematic of a sensor used to implement the exemplary light source embodiment of the present invention with flutters and waves of the sample surface at the pass-line.
FIG. 4C is a generalized schematic of a sensor used to implement the exemplary light detector embodiment of the present invention with a tilted sample surface at the pass-line.
FIG. 5 is a flow chart illustrating an exemplary method for the sensor used to implement the light detector embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
A sensor is used to measure the gloss of a sample surface by directing a beam of light at the sample surface and electronically comparing the reflectance of the sample surface to that of a standardization surface having a known gloss. According to an exemplary light source embodiment of the present invention, the light beam illuminating the sample surface may have a larger area than the light beam accepted and detected by the light detector. The illuminated area of the sample surface is larger than the area, which is seen by the light detector. The illuminated area of the sample surface is larger than the measurement area, which is seen by the light detector. This arrangement allows the sample surface to change its position within predefined geometrical limits. The measurement area of the light detector remains in the illuminated area as the sample surface moves. The intensity of reflected light received by the light detector is compared with known values of intensity for various gloss sample surfaces based on the area of the light detector.
According to an exemplary light detector embodiment, a narrow light beam is used to illuminate the sample surface and is reflected onto a light detector. The illuminated area of the sample surface is smaller than the area which is seen by the light detector. The illuminated area of the sample surface is smaller than the measurement area, which is seen by the light detector. This arrangement allows the sample surface to change its position within the geometrical limits. The measurement area of the beam remains within the detection area of the light detector as the sample surface moves. The intensity of reflected light received by the light detector is compared with known values of intensity for various gloss sample surfaces based on the area of the beam of light. The various embodiments described herein may comply with various known standards, for example, the Technical Association of the Pulp and Paper Industry (TAPPI) standards as well as other known industry and government standards.
According to an exemplary lens embodiment, a light beam may illuminate the sample surface and is reflected onto a light detector. The illuminated area of the sample surface may be collimated to a beam smaller than the area which is seen by the light detector. The illuminated area of the sample surface may be collimated to a beam larger than the area which is seen by the light detector. This arrangement allows the sample surface to change its position within the geometrical limits in a similar fashion as previously described in the light detector and light source embodiment. The measurement area of the beam remains within the detection area of the light detector as the sample surface moves. The intensity of reflected light received by the light detector is compared with known values of intensity for various gloss sample surfaces based on the area of the beam of light or the area of the light detector, respectively.
Referring to FIG. 2 , sensor 200 A may include light source 202 A with lens 203 A for providing light beam 204 A to illuminate sample surface 206 A at a pass-line. Light source 202 A and lens 203 A provide light beam 204 A with an area larger than light detection surface 210 A of the light detector 208 A. Light source 202 A provides a focused beam of light or collimated light beam for example a laser or other method of providing a focused beam of light. Light source 202 A may be a variety of electromagnetic energy sources. For example, the light source may emit a non-visible wavelength of light energy to prevent interference by overhead lighting or other sources of light within the manufacturing process.
Sample surface 206 A may be a variety of materials handled in a manufacturing process or mechanized process. For example, sample surface 206 A may be a web of paper or board. The web is continuously moved throughout the manufacturing process using various rollers, presses, and other machinery. Sample surface 206 A is not limited to a web of paper. Sample surface 206 A may be individual sheets of material that are advanced on a conveyor belt or devices for transporting sheets of material.
Sensor 200 A provides accurate measurements of the sample surface without or with a reduced need for stabilization. Light beam 204 A is reflected off the sample surface 206 A. The intensity of the reflected light is measured with a light detector 208 A. The reflected light is measured by light detecting surface 210 A of light detector 208 A to determine the light intensity of the reflected beam of light 204 A. The light detecting surface 210 A may define the area seen by the light detector 208 A. The measurement geometry and optics may be regulated by industry standards, for example, Technical Association of the Pulp and Paper Industry (TAPPI) T480.
The light detecting surface 210 A converts the beam of light 204 A into electrical current. The light detecting surface 210 A may be composed of a variety of devices, for example, Charge Coupled Device (CCD) camera, Charge Coupled Device (CCD) array, Complementary Metal Oxide Semiconductor (CMOS) camera, digital Complementary Metal Oxide Semiconductor (CMOS) imaging, or photodiodes. The light detector 208 A may be a continuous detecting device, for example, a video camera. The signal generated by light detector 208 A may be analog or converted to a digital signal for processing. The signal of light detector 208 A is fed into a reference analyzer (not shown).
Referring to FIG. 2B , as the paper moves along the manufacturing process, sample surface 206 B of the web of paper may dip, flutter, and wave due to shifts in the web of paper in both lateral and longitudinal directions. The sensor 200 B has the light source 202 B for providing the light beam 204 B to illuminate the sample surface 206 B at the pass-line. The light source 202 B provides the light beam 204 B with an area larger than a light detection surface 210 B of the light detector 208 B. The sensor 200 B provides accurate measurements of the sample surface without or with a reduced need for stabilization. The light beam 204 B is reflected off the sample surface 206 B. The intensity of the reflected light is measured with the light detector 208 B. The reflected light is measured by the light detecting surface 210 B of the light detector 208 B to determine the light intensity of the reflected beam of light 204 B. The shift of the sample surface 206 B to a new sample surface angle 212 B does not affect the gloss measurement. As long as the light detecting surface 210 B remains in the area of the light beam, the intensity detected will remain consistent based on the area of the light detection surface 210 B.
Referring to FIG. 2C , as the paper moves along the manufacturing process, sample surface 206 C of the web of paper may tilt and/or cup due to shifts in the web of paper in both lateral and longitudinal directions. The sensor 200 C has the light source 202 C for providing the light beam 204 C to illuminate the sample surface 206 C at the pass-line. The light source 202 B provides the light beam 204 C with an area larger than a light detection surface 210 C of the light detector 208 C. The sensor 200 C provides accurate measurements of the sample surface without or with a reduced need for stabilization. The light beam 204 C is reflected off the sample surface 206 C. The intensity of the reflected light is measured with the light detector 208 C. The reflected light is measured by the light detecting surface 210 C of the light detector 208 C to determine the light intensity of the reflected beam of light 204 C. The tilt of the sample surface 206 C to a new sample surface angle 212 C does not affect the gloss measurement. As long as the light detecting surface 210 C remains in the area of the light beam, the intensity detected will remain consistent based on the area of the light detection surface 210 C.
The reference analyzer compares the intensity of the signal received from light detector 210 with known values of intensity for various gloss sample surfaces. Architecturally in terms of hardware, the reference analyzer may include a processor, memory, and one or more input and output interface devices. The local interface may have additional elements, which are omitted for simplicity, such as controllers, buffers (caches), drivers, repeaters, and receivers, to enable communications. Further, the local interface may include address, control, and/or data connections to enable appropriate communications among the components of a network.
The reference analyzer may determine the gloss level of sample surface 206 by determining the ratio of the reflecting light beam intensity to the intensity of the illuminating light beam from the light source 202 . The amount of light dispersed by sample surface 206 is used to determine the gloss level of sample surface 206 . The reference analyzer may use a stored table or equations to compute the gloss level of the sample surface 206 . The gloss level is determined by comparing the ratio of intensity with the intensity of the gloss level for known sample tables of the gloss level.
The systems and methods may also be incorporated in software used with a computer or other suitable operating device of the reference analyzer. The reference analyzer may also include a Graphic User Interface (GUI) to allow the administrator or user to enter, view and store the gloss level or enter constraints associated with the desired gloss level to control other devices of the manufacturing process.
Referring to FIG. 3 , a flow chart illustrates an exemplary method for the sensor used to implement the light source embodiment 300 of the present invention. The manufacturing process advances sample surface 206 to the pass-line of sensor 200 (block 302 ). The light source 202 directs beam of light 204 onto sample surface 206 (block 304 ). The beam of light 204 is reflected by sample surface 206 (block 306 ).
The beam of light reflected by the sample surface is detected on a light detection surface 210 of the light detector 208 (block 308 ). The light detection surface 210 has an area smaller than the area of the beam of light 204 . This allows the sample surface 206 to flutter or tilt within a designated geometry. The designated geometry is controlled by the area of the beam of light 204 relative to the area of detection on the light detecting surface 210 . Increasing the area of the light beam 204 may increase the amount of movement allowed by the sample surface 206 to a new location of the sample surface 212 . Generally, the area of the beam of light 204 is circular; however, the invention may utilize a variety of shapes with either the beam of light 204 or the area of the light detection surface 210 . For example, the beam of light 204 may be a circle and the light detection surface 208 may be a square with a width larger than the diameter of the beam of light 204 . The reference analyzer determines the gloss level of the sample surface 206 by comparing the reflected light received from the area of the light detection surface 210 with known reflected light values for known sample surfaces based on the area of the light detection surface 210 (block 310 ).
Referring to FIG. 4A , the sensor 400 A may have a light source 402 A with lens 403 A for providing a light beam 404 A to illuminate the sample surface 406 A at a pass-line. The light source 402 A and lens 403 A provide a light beam 404 A with an area smaller than a light detection surface 410 A of the light detector 408 A. The light source 402 A provides a focused beam of light 404 A as previously described with regard to the exemplary light detector embodiment. The sample surface 406 A may also be a variety of materials as previously described with regard to the exemplary light source embodiment.
Sensor 400 A provides accurate measurements of sample surface 406 A without or with a reduced need for stabilization. Light beam 404 A is reflected off sample surface 406 A. The intensity of the reflected light is measured with light detector 408 A. The reflected light is measured by light detecting surface 410 of light detector 408 A to determine the light intensity of the reflected beam of light 404 A. The light detecting surface 410 A may define the area seen by light detector 408 .
Light detecting surface 410 A converts the beam of light 404 A into electrical current using a variety of light detecting elements as previously described with regard to the exemplary light source embodiment. The signal of light detector 408 A is fed into a reference analyzer (not shown). The reference analyzer compares the intensity of the signal received from light detector 410 A with known values of intensity for various gloss sample surfaces. Architecturally in terms of hardware, the reference analyzer is similar to the reference analyzer of the exemplary light source embodiment as previously described.
Referring to FIG. 4B , as the paper moves along the manufacturing process, sample surface 406 B of the web of paper may shift, flutter, and wave due to shifts in the web of paper in both lateral and longitudinal directions. Sensor 400 B has light source 402 B for providing light beam 404 B to illuminate sample surface 406 B at the pass-line. Light source 402 B provides light beam 404 B with an area smaller than a light detection surface 410 B of light detector 408 B. Sensor 400 B provides accurate measurements of the sample surface without or with a reduced need for stabilization. Light beam 404 B is reflected off sample surface 406 B. The intensity of the reflected light is measured with light detector 408 B. The reflected light is measured by light detecting surface 410 B of light detector 408 B to determine the light intensity of the reflected beam of light 404 B. The shift of sample surface 406 B to a new sample surface angle 412 B does not affect the gloss measurement. As long as the beam of light 404 B remains in the area of light detecting surface 410 B, the intensity detected will remain consistent based on the area of the beam of light 404 B.
Referring to FIG. 4C , as the paper moves along the manufacturing process, sample surface 406 C of the web of paper may tilt and/or cup due to shifts in the web of paper in both lateral and longitudinal directions. Sensor 400 C has light source 402 C for providing light beam 404 C to illuminate sample surface 406 C at the pass-line. Light source 402 C provides light beam 404 C with an area smaller than a light detection surface 410 C of light detector 408 C. Sensor 400 C provides accurate measurements of the sample surface without or with a reduced need for stabilization. Light beam 404 C is reflected off sample surface 406 C. The intensity of the reflected light is measured with light detector 408 C. The reflected light is measured by light detecting surface 410 C of light detector 408 C to determine the light intensity of the reflected beam of light 404 C. The tilt of sample surface 406 C to a new sample surface angle 412 C does not affect the gloss measurement. As long as the beam of light 404 C remains in the area of light detecting surface 410 C, the intensity detected will remain consistent based on the area of the beam of light 404 C.
The reference analyzer may determine the gloss level of the sample surface 406 by determining the ratio of the reflecting light beam intensity to the intensity of the illuminating light beam from light source 408 . The amount of light dispersed by sample surface 406 is used to determine the gloss level of sample surface 406 . The reference analyzer may use a stored table or equations to compute the gloss level of sample surface 406 . The gloss level is determined by comparing the ratio of intensity with the intensity of gloss levels for known sample tables of the gloss level.
Referring to FIG. 5 , a flow chart illustrates an exemplary method for the sensor used to implement the light detector embodiment 400 of the present invention. The manufacturing process advances sample surface 406 to the pass-line of sensor 400 (block 502 ). Light source 402 directs beam of light 404 onto sample surface 406 (block 504 ). Beam of light 404 is reflected by sample surface 406 (block 506 ).
Beam of light 404 reflected by the sample surface 406 is detected on light detection surface 410 of light detector 408 (block 508 ). Light detection surface 410 has an area larger than the area of the beam of light 404 . This allows sample surface 406 to flutter or tilt within a designated geometry. The designated geometry is controlled by the area of the beam of light 404 relative to the area of detection on light detecting surface 410 . Increasing the area of light beam 404 may increase the amount of movement allowed by sample surface 406 to a new location of sample surface 412 . The reference analyzer determines the gloss level of sample surface 406 by comparing the reflected light received from light detection surface 410 with known reflected light values for known sample surfaces based on the area of the beam of light 404 (block 510 ).
It will be understood that the foregoing is only illustrative of the principles of the invention and that various modifications can be made by those skilled in the art without departing from the scope and spirit of the invention. Accordingly, such embodiments will be recognized as within the scope of the present invention. For example, the exemplary embodiments are illustrated as being implemented to determine the gloss level of the sample surface, however, one skilled in the art will appreciate that embodiments of the invention may be implemented with a variety of other surface characteristics.
Persons skilled in the art will also appreciate that the present invention can be practiced by other than the described embodiments, which are presented for purposes of illustration rather than of limitation and that the present invention is limited only by the claims that follow. | The devices, systems and methods may continuously detect surface characteristics of a sample surface at a tilt. The exemplary system may have a conveying device for moving a sample surface, a light source for reflecting a beam of light off the sample surface, and a light detector with a light detection surface for continuous light detection. A lens may be used to reflect the beam of light from the sample surface and focus the beam of light on the light detection surface of the light detector. The area of the beam of light at the point of focus on the light detection surface may be unequal to the light detection surface. A reference analyzer may be used to determine the optical surface based on a comparison of the reflected light received with known reflected light values for known sample surfaces. | 6 |
The invention relates to reducing the aerodynamic noise that is generated by a deployed retractable aircraft undercarriage during takeoff and/or landing.
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a National Stage of International Application No. PCT/EP2010/054988 filed Apr. 15, 2010, claiming priority based on French Patent Application No. 0901845 filed Apr. 16, 2009, the contents of all of which are incorporated herein by reference in their entirety.
BACKGROUND OF THE INVENTION
It is found that a major source of the noise generated during takeoff and landing of an aircraft comes from its retractable undercarriages. Specifically, a retractable undercarriage comprises a set of wheels carried by a structure that is designed to be movable so as to enable the entire undercarriage to be retracted once the aircraft is in flight.
Given the various constraints that such an undercarriage needs to satisfy, such as withstanding forces while landing and taxiing, or the necessity of ensuring that the undercarriage can be deployed under all circumstances, the structure carrying the wheels is relatively complex.
Such a structure comprises a central leg that is pivotally mounted about a top transverse axis, and that carries the set of wheels at its bottom end. The structure also includes a plurality of bars or rods that are hinged to the leg, to the structure of the aircraft, and to one another, by as many hinges, each of which includes a pin about which the elements that are hinged together pivot. In order to reduce weight, the pins are generally hollow.
The undercarriage thus includes two rods forming a side brace for locking the leg in its deployed position, and, when the undercarriage is a nose undercarriage, two other rods that constitute a scissors linkage capable of transmitting steering movement about a vertical axis from an upper portion to the set of wheels in order to steer the aircraft.
Furthermore, the undercarriage also includes a series of flexible hydraulic and other pipes that are provided in redundant manner, going from a top portion of the undercarriage down to brakes that are fitted to the set of wheels, the pipes serving to convey the hydraulic power needed for braking.
The flexible pipes are secured to the components of the structure at particular points, e.g. by means of collars, in such a manner as to ensure they retain sufficient flexibility to enable the undercarriage to be deployed and to be retracted without damaging the pipes.
Specifically, such a retractable structure with its pieces of equipment presents a geometrical shape that is complex with a multitude of openings, baffles, and passages that generate a very large amount of aerodynamic noise when a stream of air traveling at high speed passes therethrough.
Furthermore, reducing the noise generated by an aircraft while landing and taking off nowadays constitutes a major concern.
OBJECT OF THE INVENTION
The object of the invention is to propose a solution for remedying that drawback.
SUMMARY OF THE INVENTION
To this end, the invention provides a device for limiting aerodynamic noise from a deployed aircraft undercarriage while landing and/or takeoff, the device comprising two end plates for closing respective ends of a hollow pin of the undercarriage, such as a hinge pin between two rods of the undercarriage, together with at least one tie for engaging inside the hollow pin to connect the two end plates together so as to hold them pressed against the ends of the pin.
With this solution, the aerodynamic noise of any undercarriage can be reduced without there being any need to modify the undercarriage in question, merely by means of an operation that consists in fastening two end plates to each hollow hinge pin, with the end plates being connected together by a central tie that holds them in position.
The invention also provides a device as defined above, wherein the end plates and/or the tie are made of natural fibers such as hemp or flax fibers agglomerated in a resin of reusable type.
Since the end plates and the tie are made of material that is relatively weak, they do not run any risk of damaging the blades of a jet of the aircraft itself or of a later aircraft should they become detached and drop onto the runway. Under such circumstances, the end plates also do not run any risk of damaging tires, nor do they run any risk of jamming the undercarriage while it is being raised or deployed on the aircraft itself or on a later aircraft.
The device may thus be in the form of a consumable that is made of a composite material that is degradable and/or reusable, such that the device can be considered to be an “eco-product”. Furthermore, the flexibility of the materials used enables the device to adapt to mechanical deformation of the pin.
The invention also provides a device as defined above, wherein at least one end plate includes a central orifice for having the tie pass therethrough in order to secure the tie to the end plate by means of the end of the tie passing through the end plate.
A single central tie can thus be used for holding the two end plates pressed against the ends of the hollow pin. Each end of the tie projecting through an end plate may then be connected to the end plate by any means, e.g. by attaching the end to the central orifice or to the outer face of the end plate by means of a knot, crimping, etc.
The invention also provides a device as defined above, wherein at least one locking means such as a staple for securing rigidly to an end of a tie passing through an end plate via its orifice, the locking means presenting a section greater than that of the orifice so as to bear against an outer face of the end plate.
With this solution, securing a tie to the end plate consists merely in crimping an additional staple to each end of the tie passing through an end plate when the assembly is in place.
The invention also provides a device as defined above, wherein the end plate is provided with means for locking an end of the tie passing through the central orifice therein.
By way of example, the central orifice may be itself designed to constitute a locking member, e.g. by presenting a star-shaped cutout in which the inwardly-directed tips then constitute teeth for locking the tie.
The invention also provides a device as defined above, wherein the material of the tie is a thermoplastic for connecting said tie to an end plate by using a source of heat to flatten the termination of the end of the tie passing through the central orifice of the end plate.
The invention also provides a device as defined above, wherein one face of one of the end plates includes centering means whereby it is engaged in the end of the pin that it is to close.
The invention also provides a device as defined above, wherein the centering means are formed by a reduction in the diameter of the outside edge of the end plate.
The invention also provides a device as defined above, wherein at least one end plate includes one or more openings to avoid moist air accumulating inside the pin.
BRIEF DESCRIPTION OF THE SOLE FIGURE
The sole FIGURE is a longitudinal section view showing a hollow pin of a hinge between two undercarriage elements and fitted with a device of the invention.
DETAILED DESCRIPTION OF THE INVENTION
The idea on which the invention is based lies in the observation that in a retractable undercarriage, the hollow pins that are used for hinging the various moving elements to one another, themselves constitute a significant source of aerodynamic noise.
In the invention, the ends of a hollow pin are closed by a pair of end plates that are connected together by an internal tie that presses or locks each of them against the end that it closes. The end plates and the tie are made of relatively weak material so that in the event of them becoming detached and dropping onto a runway, they will not damage the aircraft itself or a later aircraft.
The assembly constituted by the end plates and the tie may then be made out of a material that is of low cost, preferably a recyclable material, so that the device constitutes a consumable for single use. By way of example, when it is necessary to inspect the hollow pin, the existing end plates and tie are destroyed on being removed, and new end plates with a new tie are put into place after the inspection.
As shown in FIG. 1 , a hollow pin 1 of an undercarriage hinge (not shown) is cylindrical in shape, extending along and around a hinge axis AX. It comprises first and second ends 2 a and 2 b , each formed by a right section defining a respective end face, these end faces being referenced respectively 3 a and 3 b . Each end face is in the form of a plane circular annulus extending in a plane that is normal to the axis AX.
The first and second ends 2 a and 2 b are closed by respective first and second end plates 4 a and 4 b that are connected to each other by a tie 6 that is engaged in the hollow pin 1 , these end plates also being centered against the inner face 5 of the hollow pin 1 .
The first end plate 4 a is generally disk-shaped, being defined by a plane outer face 7 a and a plane inner face 8 a , and it includes a central orifice 9 a that passes right through it. This end plate presents an outer edge 11 a that comprises in succession: a first cylindrical portion 12 a joining the plane outer face 7 a ; extended by a bearing face 13 a in the shape of a plane circular annulus; and itself extended by a second cylindrical portion 14 a joining the plane inner face 8 a.
The second end plate 4 b has the same shape as the first end plate 4 a , and likewise comprises an outer face and an inner face 7 b and 8 b that are plane, together with a central orifice 9 b . Its edge 11 b is likewise constituted by three portions 12 b to 14 b , identical to the portions 12 a to 14 a.
As can be seen in the FIGURES, the first cylindrical portions 12 a and 12 b are of a diameter that corresponds to the outside diameter of the pin 1 . The second cylindrical portions 14 a and 14 b have a smaller diameter that corresponds to the diameter of the inside face 5 of the pin 1 , for the purpose of centering each of the end plates in the corresponding end of the pin 1 .
These end plates are thus generally axially symmetrical in shape and they present thickness that is small, being of the order of a few millimeters.
In addition, at least one of the end plates includes one or more additional openings that constitute vents for the purpose of preventing moist air or other fluids remaining trapped in the space defined by the hollow pin and the end plates, in order to reduce the risks of the pin oxidizing.
When the plates are in place, as shown in the FIGURE, each of them is pressed via its bearing face 13 a , 13 b against the corresponding end face 3 a , 3 b of the pin 1 . The two end plates are held pressed against the ends of the pin by the central tie 6 which connects the two end plates together while being substantially under tension.
In the example of FIG. 1 , the ends 5 a and 5 b of the central tie 6 pass through respective central orifices 9 a and 9 b , and the terminations 6 a and 6 b of these ends are flattened after the assembly has been installed on the hollow pin 1 so that these terminations present diameters that are greater than the diameters of the orifices 9 a and 9 b.
When the entire device is in place, as shown in the FIGURE, the tie 6 prevents the end plates from separating from the tube, and it is optionally under a small amount of tension in order to urge the end plates towards each other, the terminations 6 a and 6 b bearing respectively against the outer faces 7 a and 7 b of the end plates.
In practice, the material constituting the tie 6 may be a thermoplastic material so as to make the operation of flattening its ends easier during installation. Under such circumstances, the operator makes use of a source of heat initially for flattening the end 6 a of the tie 6 and engaging the tie through the orifice 9 a in the first end plate 4 a prior to engaging the tie through the hollow pin 1 so that it projects from the end 2 b of the pin 1 .
The operator can then engage the free end of the tie 6 in the orifice 9 b of the second end plate 4 b and engage the second end plate 4 b in the end 2 b of the hollow pin 1 . At this stage, the operator takes hold of the free end of the tie 6 , pulling it outwards so as to put the tie under a relatively large amount of tension, with the tie being held by pliers placed against the outer face 7 b of the second end plate. In this situation, the operator uses the source of heat to flatten the end 6 b of the tie against the sides of the pliers being used.
Once the end 6 b has been flattened, the operator allows it to cool down before releasing the pliers so that the end comes to bear against the outer face 7 b of the second end plate, in elastic manner. It will readily be understood that once installed, the tie is under tension and is connected to both end plates so as to hold them in position.
Other embodiments of the device can be envisaged concerning the general way in which the end plates are secured by one or more ties passing along the hollow pin.
For example, the system may be provided in such a manner that the tie is initially secured to one of the pins, e.g. being fastened to its inside face.
Furthermore, a tie may be secured to an end plate by means of an external staple that is crimped onto the end of the tie where it passes through an end plate. Under such circumstances, the installation is analogous to that in which the tie is made of thermoplastic material, except that instead of flattening its ends, the operator crimps a staple onto each end of the tie, e.g. using a crimping tool.
It is also possible to provide means for locking a tie end carried by one or the other or both of the end plates. For this purpose, the central orifice of one of the end plates may be provided with a star or other shape such that the inwardly-directed tips of the star-shaped cutout constitute teeth that lock the tie when it is passed through the central orifice.
The locking means may also be of any other shape, e.g. being situated on the outer face of the end plate in question.
Each end plate may also include a tie that is previously fastened to its inner face, with one of the ties then having an end provided with a clamp of the strap-tensioner type including a jaw that is closed by resilient return means.
Under such circumstances, the operator engages the tie carrying the clamp inside the hollow pin 1 , and then engages that tie in the clamp situated at the end of the other tie, and passes it back into the pin. The operator can then pull on the free tie to move the two end plates towards each other while ensuring that both ties are both under tension, which ties are joined together inside the hollow pin by the clamp forming a strap-tensioner or brake.
Furthermore, the device may be made out of materials based on fibers of biological origin and on resin of reusable type in order to reduce the impact of fabrication on the environment, while also obtaining a device at low cost.
The end plates may be fabricated from short fibers of natural origin such as hemp or flax fibers, and from a thermoplastic resin or biopolymers in which the fibers are agglomerated.
The tie may be made from one or more strands of hemp or flax fibers of natural origin and coated or embedded in a thermoplastic resin or biopolymers.
In general, the device constitutes a non-stressed member since forces other than those that serve to hold it in place do not pass through this member. The flexibility of the end plates and of the tie serve to absorb impacts, e.g. while landing. If an impact is too great, then the device may be separated from the pin and may be destroyed without damaging the aircraft itself or any later aircraft. | In the field of aviation, a device for limiting aerodynamic noise from a deployed aircraft undercarriage during landing and/or takeoff. The device comprises two end plates ( 4 a , 4 b ) for closing respective ends ( 2 a , 2 b ) of a hollow pin ( 1 ) of the undercarriage, such as a hinge pin between two rods of the undercarriage, together with at least one tie ( 6 ) for engaging inside the hollow pin ( 1 ) to connect the two end plates ( 4 a , 4 b ) together so as to hold them pressed against the ends ( 2 a , 2 b ) of the pin ( 1 ). | 1 |
BACKGROUND OF THE INVENTION
This invention relates to variable area exhaust nozzles for gas turbine engines and, more particularly, to sealing means for nozzle flaps of turbojet engines.
The exhaust nozzle of a gas turbine engine, such as a turbojet or turbofan engine, has as its purpose a transformation of the pressure and thermal energy of the combustion discharge into velocity, with the forward thrust of the engine being directly proportional to the increase in velocity of the gas from the entrance of the engine to the exit plane of the nozzle. In high performance engines and, in particular, in engines having some sort of thrust augmentation such as an afterburner, it has been found desirable to cause a variation of nozzle flow area to maintain high engine performance under a wide range of operating conditions. For example, it is desirable to provide a larger nozzle flow area during a take-off mode of operation than during a cruise mode. In addition to the function of maintaining the exhaust gas temperature within allowable limits, variable area exhaust nozzles may be employed to bring about noise, thrust and fuel economy benefits. One means for varying the nozzle flow area is by the so-called iris mechanism wherein a plurality of concentrically disposed movable members or flaps are pivotably supported about the nozzle axis. One of the problems associated with such an arrangement is the need to maintain effective sealing between the flaps as the flaps are adjusted to vary the nozzle flow area. Therefore, it is desirable to provide an exhaust nozzle whose area can be flexibly varied between minimum and maximum positions while maintaining a circumferentially continuous aerodynamic structure throughout the entire range.
Early method of locating seals with respect to exhaust nozzle flaps relied entirely on a combination of bolts and spectacles wherein, when the nozzle was in the closed position the seals were relatively free to move in the circumferential direction, and when the flaps moved toward the open position, the position of the seals was still not positively enough controlled so as to maintain circumferential sealing integrity around the entire nozzle periphery. Some of the problems encountered were those of dimensional stack-up, limited seal overlap within the circumferential envelope, and misalignment due to nozzle sag on or near the horizontal plane. These problems caused nozzle leakage and seal "blow-out", thereby resulting in decreased nozzle efficiency.
Recent methods of effecting positive placement of seals within exhaust nozzles employ a combination of linkage pairs interconnecting the flaps to the seal wherein an axial track is located on the seal for the purpose of varying the effective lengths of the links. Such an arrangement has been recognized as being somewhat complex and requiring an excess number of moving parts which are susceptible to wear and malfunction.
Accordingly, a primary object of the present invention is to provide an improved seal arrangement for a jet engine variable exhaust nozzle flap.
Another object of this invention is the provision in a variable exhaust nozzle for the maintaining of circumferential sealing integrity throughout the range of nozzle areas.
Yet another object of the present invention is the provision for maintaining a variable area exhaust nozzle seal in a centered relationship between adjacent flaps during all modes of nozzle operation.
These objects and other features and advantages become more readily apparent upon reference to the following description when taken in conjunction with the appended drawings.
SUMMARY OF THE INVENTION
Briefly, in accordance with one aspect of the invention, the individual seal members which are located in overlapping relationship between each adjacent pair of flaps, are mechanically connected to the flaps by way of a three-bar linkage, or bellcrank, combination. The end bars which are attached to opposite ends of the center bar, provide positive connection to the respective flaps while the center bar is rotatable to accommodate the variable effective lengths of the end bars as the flaps are modulated throughout the operating range. In this way the axial track and associated moving parts are eliminated.
By another aspect of the invention, a circumferential track is provided on the respective flaps to receive a mating projection from the interposed seal in such a manner as to stabilize the axial position of the seal over the entire range of nozzle flap movement.
By yet another aspect of the invention, the clevises of adjacent flaps, which are mechanically connected to the respective end bars, are axially misaligned in such a manner as to reduce the axial loads on the center pin which connects the center bar to the seal member. Further, the respective lengths of the two end bars are different to the extent necessary to enable balanced mechanical operation in view of the fact that one is located axially forward of the other and is therefore exposed to a smaller arc of movement for a given variable exhaust area.
In the drawings as hereinafter described, the preferred embodiment is depicted; however, various other modifications and alternative constructions can be made thereto without departing from the true spirit and scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a jet engine exhaust nozzle with a preferred embodiment of the present invention incorporated therein.
FIG. 2 is a fragmentary rear view of the exhaust nozzle showing the bellcrank portion thereof in accordance with a preferred embodiment of the invention.
FIG. 3 is a fragmentary top view of the bellcrank portion thereof in a position which represents a closed-nozzle position.
FIG. 4 is a top view thereof showing the bellcrank in an open nozzle position.
FIG. 5 is a fragmented longitudinal section view of the nozzle with the preferred embodiment of the present invention incorporated therein.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, the present invention is shown generally at 10 as being incorporated into an iris-type jet engine exhaust nozzle 11 comprising in serial flow relationship a fixed area duct 12 and a variable area downstream section 13. Although the nozzle as shown is of the convergent-divergent type wherein the downstream section 13 includes both a convergent and a divergent section as will be discussed hereinafter, the present invention is not intended to be limited to such a structure.
The variable area section 13 includes at its outer periphery a plurality of circumferentially spaced, outer flaps 14 having their forward end 16 hinged on a common circle in such a way as to collectively define a continuous downstream converging frustum of a cone when the nozzle is in the closed position, and forming a discontinuous frustum of a cone when in the open position, the discontinuity being pie-shaped in form. In order to offset the aerodynamic effect of these discontinuities, a plurality of outer seals 17 are placed in close relationship with the inner sides of the flaps, with an outer seal being placed between each pair of outer flaps so as to effectively seal off the discontinuities whenever the nozzle is not in the fully closed position. Together the nozzle outer flaps 14 and the outer seal 17 define the outer flow path of the variable area section 13 of the nozzle.
Referring now to the inner flow path of the variable area section 13 of the nozzle, a plurality of circumferentially spaced, internal convergent flaps (not shown) comprise the upstream convergent section and a plurality of circumferentially spaced divergent flaps, immediately downstream, comprise the divergent section. When the divergent flaps are in the closed position, they define a circumferentially continuous inner flow annulus and when opened by rotation of the individual flaps about their axes located on a common circle at their forward ends, they tend to create pie-shaped discontinuities which are sealed by a plurality of inner seals 19 which are disposed in close-sealing relationship with the inner surface of the divergent flaps 18. It will be recognized that as the divergent flaps 18 are opened, in order to maintain an optimum sealing relationship with the inner seals 19, it is necessary to maintain the position of the seals in a centered relationship with respect to the adjacent flaps 18. For this purpose, the bellcrank arrangement shown generally at 10 is incorporated and will be more fully discussed hereinafter. It should be noted that in order to maintain the inner seal in alignment it will be necessary to have a pair of axially spaced centering devices, at least one of which comprises the present bellcrank arrangement; however, for purposes of description only a single such device is shown in FIG. 1.
Variations in the nozzle area are generally controlled by either a crew command or automatically in accordance with engine performance requirements and are generally accomplished by hydraulic means. The plurality of hydraulic actuators 21 are disposed around the duct portion 12 of the nozzle with their one end 22 connected by a mounting plate 23 to a ring 24 which tends to fix the radial position of the actuators. The other end 26 of the actuator 21 is connected by a bolt 27 to a clevis 28 which extends from a fixed diameter actuation ring 29. Similarly, a pair of support links 31 and 32 located one on either side of the actuator 21 rigidly attach the mounting plate 23 to a stationary collar 33, their purpose being to transfer the axial forces of the actuator back to a stable portion of the structure. Also connected to the stationary collar 33 by way of the secondary drive links 34 are each of the divergent flaps 18.
Briefly, variation in the area of the nozzle is accomplished as follows. When it is desired to open the nozzle from its fully closed position, hydraulic fluid is supplied to the actuators so as to extend their length and move the actuation ring 29 axially rearward. Simultaneously, the cammed surface 36, which forms a part of the convergent flap (not shown), and which engages a roller 37 on the actuation ring 29, is allowed to move radially outward with rearward movement of the actuation ring 29. In this way, the area of the variable area section portion of the nozzle (including both the convergent and divergent sections) is increased. To close the nozzle, the process is reversed.
Referring to that portion of the nozzle as shown in FIGS. 2 and 5, the divergent flap 18 is connected to the secondary drive link 34 by way of a bracket 38 and included bolt 39. The inner seals 19 are located radially inward from the divergent flap 18, one on either side of the flap, with each having a beveled portion 41 which fits flatly against and closely engages the inner side 42 of the divergent flap 18. Disposed in each of the inner seals 19, at the circumferential center thereof, is a post 43 extending radially outward for receiving the apparatus which interconnects with the adjacent flaps. An elongate, angled follower 44 fits over the post 43 and extends outwardly on either side thereof to engage with its opposite ends 46 and 47, the respective circumferential tracks 48 and 49 formed in the outer sides of the adjacent inner flaps. The follower 44 and associated tracks function to maintain the axial position of the inner seal 19 relative to the inner flaps as will be described more fully hereinafter.
Also mounted to each of the posts 43 is an elongate center bar 51 which is rotatably mounted on or near its center. On the opposite ends of the center bar 51 are clevises 52 and 53 for receiving pins 54 and 56, respectively. Connection to the adjacent inner flaps is then effected by end links 57 and 58 and associated clevises 59 and 61.
Operation of the bellcrank apparatus comprising the center bar 51 and end bars 57 and 58 can be seen in FIGS. 3 and 4. In FIG. 3 the flaps 18 are in the closed position and the inner seal 19 is centered therebetween and overlaps to the maximum extent on either side. The bellcrank is in the retracted position and rigidly holds the inner seal 19 transversely with respect to the flaps, and the follower and track combination fixes the axial position of the inner seal with respect to the flaps. As the flaps are opened by operation of the actuators 21 in the manner discussed hereinabove, the center bar 51 begins to rotate in the clockwise direction to extend the bellcrank arrangement to the fully opened position as shown in FIG. 4. At the same time the follower ends 46 and 47 are allowed to slide within the tracks 48 and 49 to allow the flaps to separate while at the same time fixing the axial position of the inner seal with respect to the flaps. It will be seen by reference to FIGS. 3 and 4 that the centerbar 51 is attached substantially at its centerpoint and that the end links 57 and 58 are of substantially equal length and aligned in parallel relationship at all times. Considering the differences between the arcs of movement of the forward link 57 and that of the aft link 58 when the flaps and seals are rotated about a forward axis, it has been found desirable to shorten or lengthen the links appropriately in order to accommodate these differences and balance the loads. For example, for these reasons it is desirable to have the forward portion (that connected to link 57) of the center bar slightly shorter than the aft section thereof. Similarly, it is also desirable to have the link 57 slightly shorter than the link 58 for the same reason.
Further, it can be seen from FIG. 2 that the connection of the end link 57 to the clevis 52 is not squarely in line and, in fact, the axis of the end link 57 will move as the flaps are opened. For this reason it is desirable to have a three-dimensionally flexible connection such as a uniball or the like between the end link and the center bar.
It will be understood that while the present invention has been described in terms of a preferred embodiment, it may take on any number of other forms while remaining within the scope and intent of the invention. | A variable area exhaust nozzle is provided with seals between adjacent flaps to minimize flow loss therebetween when the flaps are modulated between minimum and maximum nozzle area positions. The overlapping seals is linked to the adjacent flaps by means of a bellcrank which operates to maintain the seal in a centered position between the flaps. A circumferential track is provided on the flaps to stabilize the seal in the axial direction. | 5 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is related to U.S. application Ser. No. 08/167,519, filed Dec. 15, 1993, now abandoned, which is incorporated herein by reference in its entirety.
CROSS REFERENCE TO RELATED APPLICATIONS
This application is related to U.S. application Ser. No. 08/167,519, filed Dec. 15, 1993, now abandoned, which is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to methods and compositions for treating human immunodeficiency virus (HIV) infected individuals by administering to such individuals, compositions which inhibit or prevent replication of the HIV. In particular, the present invention relates to compositions which inhibit or prevent the replicatire and other essential functions of HIV viral protein R (vpr) by competitively binding to the vpr target in human cells, the vpr binding protein (rip-1). More particularly, the present invention relates to compositions which are glucocorticoid receptor (GR) antagonists, which by binding to rip-1, a GR type molecule, prevent vpr from binding to rip-1, and thereby interfere in the essential activities of the complex necessary for HIV replication. In particular, the antagonist prevents translocation of the vpr/rip-1 complex from the cytosol to the nucleus, or signaling of said translocated complex, whereby vpr would otherwise carry on its various activities essential to replication of HIV. The present invention also relates to methods of identifying such compositions which inhibit or prevent replication of HIV.
2. Brief Description of the Prior Art
One approach to treating individuals infected with HIV is to administer to such individuals compounds which directly intervene in and interfere with the machinery by which HIV replicates itself within human cells. With that approach in mind, it is first noted that HIV is a lentivirus whose genome contains only about 9-11 kb of genetic material and less than 10 open reading frames. Thus, each HIV gene is likely to play a vital role in the natural history of the virus in vivo. Further, HIV possesses a collection of small, positive strand open reading frames which encode 1-2 exon genes whose protein products regulate various aspects of the virus' life cycle. Some of these genes are genetic transactivating factors which are necessary for virus replication in all permissive cell types.
The complexity of HIV can thus be attributed to the intricate patterns of regulation of gene expression observed during the vital lifecycle. Since all such regulatory mechanisms are accomplished by the interaction of virally encoded proteins with distinct host cell factors, it is possible to discover compounds which directly interfere with the binding and translocation of those proteins which are essential to replication of HIV.
The progression from HIV infection to AIDS is in large part determined by the effects of HIV on the cells that it infects, including CD4 + T lymphocytes and macrophages. On the other hand, cell activation, differentiation and proliferation in turn regulate HIV infection and replication in T cells and macrophages. Gallo, R. C. et al. (1984) Science 224:500; Levy, J. A. et al., (1984) Science 225:840; Zack, J. A. et al. (1988) Science 240:1026; Griffin, G. E. et al., (1988) Nature 339:70; Valentin, A. et al. (1991) J. AIDS 4:751; Rich, E. A. et al., (1992) J. Clin. Invest. 89:176; and Schuitemaker, H. et al. (1992) J. Virol. 66:1354. Cell division per se may not be required since HIV and other lentiviruses can proliferate in nonproliferating, terminally differentiated macrophages and growth-arrested T lymphocytes. Rose, R. M. et al. (1986) Am. Rev. Respir. Dis. 143:850; Salahuddin, S. Z. et al. (1986) Blood 68:281; and Li, G. et al. (1993) J. Virol. 67:3969. The ability of lentiviruses, including HIV, to replicate in nonproliferating cells, particularly in macrophages, is believed to be unique among retroviruses and it is significant that several lentiviruses contain a vpr-like gene. Myers, G. et al. (1992) AIDS Res. Hum. Retrovir. 8:373. HIV infection of myeloid cell lines can result in a more differentiated phenotype and increase the expression of factors such as NF-KB which are necessary for HIV replication. Roulston, A. et al. (1992) J. Exp. Med. 175:751; and Chantal Petit, A. J. et al. (1987) J. Clin. Invest. 79:1883.
Since the demonstration in 1987 that the small open reading frame within HIV-1 designated R encodes a 15 KD protein (Wong-Staal, F., et al., (1987) AIDS Res. Hum. Retroviruses 3:33-39), there has been a growing body of literature regarding the function of the virat protein R (vpr). The vpr open reading frame is conserved within all genomes of HIV-1 and HIV-2 and within all pathogenic isolates of simian immunodeficiency virus (SIV) genomes. The evolutionary requirement for economy in design is deemed to require that the presence of vpr in the HIV genome is related to a specific and non dispensable function in the vital life cycle. Furthermore, the vpr protein is the only HIV-1 regulatory gene product which has been shown to be incorporated into virions. This would normally suggest a structural role for vpr, but since vpr deleted viruses are able to produce normal virions, this is deemed to be further evidence of a regulatory role for this molecule.
Further, the presence of vpr in virions has been associated with increased replication kinetics in T lymphocytes, and with the ability of HIV to establish productive infection in monocytes and macrophages. Thus, it has been reported that mutations in the vpr gene result in a decrease in the replication and cytopathogenicity of HIV-1, HIV-2, and SIV in primary CD4 + T lymphocytes and transformed T cell lines. See, e.g., Ogawa, K., et al., (1989) J. Virol. 63:4110-4114; Shibata, R., et al. (1990a) J. Med. Primatol. 19:217-225; Shibata, R., et al. (1990b) J. Virol. 64:742-747 and Westervelt, P. et al. (1992) J. Virol. 66:3925, although others have reported that mutated vpr gene had no effect on replication (Dedera, D., et al. (1989) Virol. 63:3205-3208).
Importantly, HIV-2 mutated for vpr has been reported unable to infect primary monocyte/macrophages (Hattori, N., et al. (1990) Proc. Natl. Acad. Sci. U.S.A. 87:8080-8084). Further, viral replication in macrophages may be almost completely inhibited by antisense ribonucleotides targeting the vpr open reading frame. This, together with the induction of rhabdomyosarcoma cellular differentiation, are deemed to dictate a crucial function for vpr in HIV pathogenesis.
The presence of vpr protein in vital particles means an early function for vpr during the infection process, following virus penetration and uncoating. This role is considered to involve vpr interaction with cellular regulatory mechanisms resulting in an increase in cell permissiveness to sustain viral replication processes. See, e.g., Cohen, E. A., et al. 1990a J. Virol. 64:3097-3099; Yu, X. F., et al. (1990) J. Virol. 64:5688-5693.; and, Yuan, X., et al., (1990) AIDS Res. Hum. Retroviruses 6:1265-1271.
Vpr action can involve the upregulation of cellular elements which enhance viral gene expression, or the downmodulation of cellular inhibitory pathways affecting such vital processes. Such cellular disregulation is consistent with the observation that vpr is sufficient for the differentiation and cessation in cellular proliferation of rhabdomyosarcoma and osteosarcoma cell lines. Thus, the vpr gene of HIV-1 has been shown to induce cellular growth inhibition and differentiation in tumor lines of intermediate differentiation in vitro (Levy, D. N. et al. (1993) Cell 72:541). Thus, the ability of a vitally associated protein such as vpr to reinitiate an arrested developmental program is clearly based upon its interaction with other cellular proteins, and since vpr protein originates within viral particles, it is considered that vpr must, accordingly, play a role in establishing productive infection.
In order for vpr to exert its cellular effects, it requires a cellular ligand, which would mediate these functions. There has been no description heretofore of such a ligand, which may also be referred to as a receptor or binding protein, for vpr. Accordingly, there is described herein, as a part of the present invention, the isolation of a 41 KD vpr cytosolic binding protein, rip-1. Vpr and rip-1 coelute in an immunoaffinity system, and can be specifically crosslinked to a 58 KD complex. Using peptide and antibody competition, the site of their interaction has been resolved to amino acids 38 to 60 on the vpr amino acid sequence. Rip-1 has been detected in various cell lines. Rip-1 selectively translocates from the cytosol to the nucleus upon exposure of the cell to vpr either in a soluble form, or through infection with wild type virus, but not in response to PMA, suggesting a coupling in their regulatory functions.
Part of the present invention is the discovery, described in detail further below, of the likelihood that rip-1 is a member of the steroid hormone receptor superfamily, and particularly, that it behaves as a member of the glucocorticoid receptor (GR) family, and more particularly, that it behaves as a GR type II receptor molecule. Thus, it is a key aspect of the present invention to treat individuals infected with HIV, by administering to such individuals compounds which are steroid hormone receptor antagonists, particularly glucocorticoid receptor antagonists, and more particularly GR type II receptor antagonsts. Such receptor antagonists of the present invention will inhibit or prevent the replicatire and other essential functions of vpr by competitively binding to the vpr target in human cells, the vpr binding protein, rip-1.
Perhaps the best known glucocorticoid receptor antagonist is RU-486, or mifepristone. Acting also as a progesterone receptor antagonist, it is a therapeutic abortifacient approved for use in combination with prostaglandins, in Europe and elsewhere. Many other such glucocorticoid receptor antagonists have been described in the literature. While it is possible that RU-486 may have been taken by an individual who was also suffering from an HIV infection at the time, such use would have been purely coincidental, since there has been no suggestion until the present invention that a glucocorticoid receptor antagonist would in any way inhibit or prevent replication of HIV. Moreover, such coincidental use would in all likelihood also have included the concomitant use of prostaglandins, a combination wholly outside the scope of the present invention.
There remains an urgent need to identify methods of treating individuals suffering from HIV infection. There remains a need to identify compounds which prevent or inhibit HIV replication in infected cells and thereby are useful for treating individuals suffering from HIV infection.
SUMMARY OF THE INVENTION
The present invention relates to A method for treating an individual exposed to or infected with HIV comprising administering to said individual a therapeutically effective amount of one or more compounds which inhibit or prevent replication of said HIV by interfering with the replicatire or other essential functions of vpr expressed by said HIV, by competitively binding to the vpr target in human cells, rip-1, so as to interfere in the essential activities of said complex necessary for HIV replication. In particular, the antagonist prevents translocation of the vpr/rip-1 complex from the cytosol of said human cells to the nuclei of said cells, or signaling of said translocated complex, whereby vpr would otherwise carry on activities essential to replication of HIV. Based on rip-1 being a member of the steroid hormone receptor superfamily, and particularly, on its being a member of the glucocorticoid receptor (GR) family, and more particularly, on its being a GR type II receptor molecule, it has been discovered that compounds which are especially effective for this method of treatment are those compounds which are antagonists for the receptors just mentioned.
Particularly therefore, the present invention relates to a method for treating HIV infected individuals by administering to such individuals a therapeutically effective amount of a composition comprising one or more steroid hormone receptor antagonists, preferably glucocorticoid receptor antagonists, more preferably glucocorticoid receptor Type II antagonists, which bind to rip-1, prevent vpr from binding to rip-1, and thereby prevent translocation of the vpr/rip-1 complex from the cytosol to the nucleus of the infected cell, where vpr carries on its various activities essential to replication of HIV.
The present invention also relates to such a method of treating HIV infected individuals as described above, wherein there is coadministered with one or more of said glucocorticoid receptor antagonists, one or more therapeutic agents useful for treating HIV infected individuals, selected from the group consisting of zidovudine (AZT), acyclovir, ganciclovir, foscarnet, interferon alpha-2a, and interferon alpha-2b.
The present invention further relates to a pharmaceutical composition for treatment of an individual exposed to or infected with HIV comprising a therapeutically effective amount of one or more compounds which inhibit or prevent replication of said HIV by interfering with the replicatire or other essential functions of vpr expressed by said HIV, by competitively binding to the vpr target in human cells, rip-1, whereby vpr would otherwise carry on activities essential to replication of HIV; or a pharmaceutically acceptable salt or ester thereof; and a pharmaceutically acceptible carrier therefor.
The present invention also relates to a pharmaceutical composition wherein said compound also prevents translocation of the vpr/rip-1 complex from the cytosol of said human cells to the nuclei of said cells, or signaling of said translocated complex, whereby vpr would otherwise carry on activities essential to replication of HIV.
The present invention further relates to a pharmaceutical composition wherein the compound or compounds which competitively bind to rip-1, or also in addition prevent or inhibit translocation of the vpr/rip-1 complex from the cytosol of said human cells to the nuclei of said cells, or signaling of said translocated complex, is one or more members selected from the group consisting of steroid hormone receptor antagonists, glucocorticoid receptor antagonists, and glucocorticoid receptor Type II antagonists. In particular, the present invention relates to a pharmaceutical composition for treatment of an individual exposed to or infected with HIV comprising a therapeutically effective amount of one or more compounds which are glucocorticoid receptor Type II antagonists, or a pharmaceutically acceptable salt or ester thereof; and a pharmaceutically acceptible carrier therefor.
The present invention also relates to pharmaceutical compositions comprising a therapeutically effective amount of one or more of said glucocorticoid receptor antagonists, together with one or more therapeutic agents useful for treating HIV infected individuals, selected from the group consisting of zidovudine (AZT), acyclovir, ganciclovir, foscarnet, interferon alpha-2a, and interferon alpha-2b, together with a pharmaceutically acceptable carrier.
The present invention further relates to pharmaceutical composition for treatment of an individual exposed to or infected with HIV comprising a therapeutically effective amount of one or more compounds which inhibit or prevent replication of said HIV by interfering with the replicatire or other essential functions of vpr expressed by said HIV, by competitively binding to the vpr target in human cells, rip-1, or additionally preventing translocation of the vpr/rip-1 complex from the cytosol of said human cells to the nuclei of said cells, whereby vpr would otherwise carry on activities essential to replication of HIV; or a pharmaceutically acceptable salt or ester thereof; together with one or more therapeutic agents useful for treating HIV infected individuals, selected from the group consisting of zidovudine (AZT), acyclovir, ganciclovir, foscarnet, interferon alpha-2a, and interferon alpha-2b; together with a pharmaceutically acceptable carrier therefor.
The present invention still further relates to a method of identifying a compound which is capable of inhibiting or preventing replication of HIV by interfering with the replicatire or other essential functions of vpr by competitively binding to the vpr target in human cells, rip-1, expressed by said HIV, whereby vpr would otherwise carry on activities essential to replication of HIV; said method comprising, in a culture of HIV infected human cells, the step of contacting vpr and rip-2 or a fragment thereof in the presence of said test compound, determining the level of binding and comparing that level to the level of binding that occurs when vpr and rip-1 are contacted in the absence of said test compound. This method also comprises the additional step, where said test compound is determined to have substantially inhibited or prevented formation of said vpr/rip-1 complex by competitively binding to rip-1, of determining the level of p24 produced in said HIV infected cells receiving said test compound, and comparing said level to the level of p24 produced by HIV infected cells having vpr delected from said HIV, as well as to the level of p24 produced in the absence of said test compound.
The present invention also includes a method as described above for identifying a compound which competitively binds to rip-1, wherein said compound also prevents translocation of the vpr/rip-1 complex from the cytosol of said human cells to the nuclei of said cells, or signaling of said translocated complex, whereby vpr would otherwise carry on activities essential to replication of HIV; comprising the additional step of conducting an assay which is capable of determining nuclear colocalization of vpr and rip-1, and determing the level of said colocalization in the presence of said test compound and comparing it to the level of colocalization in the absence of said test compound. Such a may comprise the additional step, where said test compound is determined to have substantially inhibited or prevented said colocalization, of determining the level of p24 produced in said HIV infected cells receiving said test compound, and comparing said level to the level of p24 produced by HIV infected cells having vpr delected from said HIV, as well as to the level of p24 produced in the absence of said test compound.
The present invention still further includes a method of identifying a compound which is a glucocorticoid receptor antagonist and which is capable of inhibiting or preventing replication of HIV by interfering with the replicative or other essential functions of vpr by competitively binding to the vpr target in human cells, rip-1, expressed by said HIV, whereby vpr would otherwise carry on activities essential to replication of HIV; said method comprising the steps of (1) determining glucocorticoid antagonist activity of a test compound, and if said test compound exhibits glucocorticoid antagonist activity, (2) contacting vpr and rip-1 or a fragment thereof in the presence of said test compound, determining the level of binding and comparing that level to the level of binding that occurs when vpr and rip-1 are contacted in the absence of said test compound. This method is particularly one wherein glucocorticoid antagonist activity is measured by determining the effect of said test compound on tyrosine amino-transferase in accordance with the method of Granner and Tompkins, (1970) Meth. Enzymol. 15, 633. This method also comprises the additional step, where said test compound is determined to have substantially inhibited or prevented formation of said vpr/rip-1 complex by competitively binding to rip-1, of determining the level of p24 produced in said HIV infected cells receiving said test compound, and comparing said level to the level of p24 produced by HIV infected cells having vpr delected from said HIV, as well as to the level of p24 produced in the absence of said test compound.
The method described above is also one for identifying a glucocorticoid receptor antagonist compound which competitively binds to rip-1, wherein said compound also prevents translocation of the vpr/rip-1 complex from the cytosol of said human cells to the nuclei of said cells, or signaling of said translocated complex, whereby vpr would otherwise carry on activities essential to replication of HIV; and comprises the additional step of conducting an assay which is capable of determining nuclear colocalization of vpr and rip-1, and determing the level of said colocalization in the presence of said test compound and comparing it to the level of colocalization in the absence of said test compound. This method still further comprises the additional step, where said test compound is determined to have substantially inhibited or prevented said colocalization, of determining the level of p24 produced in said HIV infected cells receiving said test compound, and comparing said level to the level of p24 produced by HIV infected cells having vpr delected from said HIV, as well as to the level of p24 produced in the absence of said test compound.
The present invention also relates to a kit for identifying compounds which inhibit vpr protein binding to rip-1 which comprises a first container comprising tyrosine amino-transferase, a second container comprising vpr protein and a third container comprising rip-1 or a fragment thereof; and optionally, in a preferred embodiment of this aspect of the invention, a fourth container comprising an antibody that specifically binds to either the vpr protein or rip-1 is provided.
The present invention involves the use of rip-1, which is essentially pure human protein that has an apparent molecular weight of between 40-43 KD, that occurs in the cytoplasm of human cells, that binds to vpr, and that is transported from the cytoplasm to the nucleus when bound to vpr to form a complex; or a fragment thereof. Rip-1 may be produced by the method comprising the step of culturing a host cell that comprises an expression vector that comprises a nucleotide sequence that encodes rip-1, or a fragment thereof, and isolating the protein or fragment that is produced in the cultured cells.
DETAILED DESCRIPTION OF THE INVENTION
The present invention arises out of the discovery that HIV regulatory protein R, referred to herein as "vpr", binds to a human protein that occurs in the cytoplasm of human cells and that has an apparent molecular weight of between 40-43 KD. It has been discovered that when vpr binds to this human protein, the proteins form a complex which is transported from the cytoplasm to the nucleus. Thus, the human protein acts as a receptor or binding protein for vpr, and is therefore referred to herein as "rip-1".
Action of Glucocorticoid Receptor Antagonists
As used herein, the term "rip-1" is meant to refer to the human protein that has an apparent molecular weight of between 40-43 KD, that occurs in the cytoplasm of human cells, that binds to vpr and that is transported from the cytoplasm to the nucleus when bound to vpr. The rip-1 may be colocalized with the T-cell and B-cell transcription factor NFκB. It has been discovered that the rip-1 behaves as a member of the steroid hormone receptor superfamily, and particularly, that it behaves as a member of the glucocorticoid receptor (GR) family, and more particularly, that it behaves as a GR type II receptor molecule.
The discovery that the rip-1 in human cells behaves as a member of the steroid hormone receptor superfamily, especially the glucocorticoid receptor family, elucidates the manner in which the binding of vpr to rip-1 is involved in HIV replication and thus pathogenesis. Accordingly, preventing or inhibiting such interaction by blocking the rip-1 with a different compound that competitively binds to it, effectively inactivates vpr and prevents it from converting cells to better HIV replication hosts. The identification of compounds which can inhibit the effects of vpr and thereby inhibit HIV replication in HIV infected cells is based on the discovery that many of the actions of vpr are analogous to those of a glucocorticoid. The mechanism of action of vpr allows for the targeting of that mechanism for active intervention, and thereby the rational design and selection of anti-HIV compounds.
The cellular trafficking characteristics which have been observed for rip-1 are consistent with rip-1 being a member of the steroid hormone receptor superfamily. The glucocorticoid and mineralocorticoid receptors are the only members of this protein family which translocate from the cytoplasm to the nucleus upon exposure to their ligand. Two types of glucocorticoid receptors have been described. Type I receptors are concentrated in the nucleus even when there is no ligand present. Type II receptors specifically concentrate in the cytoplasm in the absence of ligand, and only translocate to the nucleus in the presence of their appropriate stimulating hormone. The two types of gtucocorticoid receptors have high affinity for their specific ligands, and are considered to function through the same transduction pathways. The main functional difference between these two classes of receptors is that the type II receptors are activated by their ligands in such a way that they only transactivate their target cellular protooncogenes in some, but not in all cells. Such cellular specificity is not observed in type I receptors. These observations are consistent with rip-1 being type II molecule.
Glucocorticoid receptors have a number of roles. Glucocorticoid receptors have been shown to act as a powerful transactivator. Glucocorticoid receptors have also been shown to operate through the repression of gene expression for particular open reading frames. Glucocorticoid receptor mediated repression is attained by competition for the sites on the DNA molecule which would otherwise be bound by transactivators. An example of the latter is the specific bilateral relationship which has been described for glucocorticoid receptors and c-Jun. In this case, the glucocorticoid receptor represses c-Jun activity, and the opposite is also observed. The phorbol ester PMA has been reported to activate transcription of the AP-1/c-Jun promoter. In addition, glucocorticoids have been shown to counter lymphokine activity as observed by the inhibition of proliferation of a variety of cell lines. This mechanism is deemed to affect immunoregulatory mechanisms in areas such as T cell activation, which is in part mediated by the Jun/AP-1 activity, and its resulting lymphokines. The observation of a cessation in proliferation in different cell lines transfected with vpr is considered explained by a glucocorticoid receptor mediated pathway, in which rip-1 acts to bridge vital and cellular activities.
It is also important to note that the glucocorticoid receptors function as a part of a larger multimeric complex. These 330 KD protein clusters comprise a heat shock protein 90 dimer, a heat shock protein 56 unit, and sometimes by a heat shock protein 70 unit (HSP 70), in addition to the specific glucocorticoid receptor molecule; and rip-1 has been observed in association with this HSP 70. The glucocorticoid receptor polypeptide itself is usually composed of three functional domains arranged in a linear configuration; a hormone binding domain, a DNA binding domain, and a third domain which has been shown to interact with additional cellular proteins, defining the trafficking characteristics of this gene product. Rip-1 is the first vpr associating protein which has been identified in accordance with the present invention, but it is possible that other gene products may either interact with vpr directly, or indirectly through rip-1 mediated associations. The relationship between vpr and the glucocorticoid receptor related heat shock proteins which is deemed to exist in accordance with the present invention, dictates that rip-1 be considered a member of the steroid hormone receptor superfamily. In addition, this will indicate what cellular functions respond to vpr caused cellular disregulation effects which vpr has been observed to induce.
In accordance with the principles set out above, the present invention provides for treatment of individuals infected with HIV by administering to them a therapeutically effective amount of a compound which is asteroid hormone receptor antagonist that competitively binds to rip-1, preventing or inhibiting formation and translocation of the vpr/rip-1 complex. Particularly, the present invention provides for such treatment by administration of a therapeutically effective amount of a glucocorticoid receptor antagonist, especially a type II glucocorticoid receptor antagonist.
As used herein, the term "glucocorticoid receptor antagonist" simply means any compound which will bind to the glucocorticoid receptor, and which will, therefore, also competitively bind to rip-1 so as inhibit or prevent formation of the vpr/rip-1 complex. In this context, the term "antagonist" refers to the blocking of the rip-1 receptor by the compound, thus preventing the natural ligand, vpr, from binding to it, thus creating an antagonism by preventing the agonist from acting. With respect to the glucocorticoid receptor itself, however, it is not necessary that the compound be, strictly speaking, a glucocorticoid antagonist, i.e., have antiglucocorticoid activity. Thus, such a compound may be either an agonist or antagonist; however, it is preferred to select compounds which have antiglucocorticoid activity, i.e., which bind to the glucocorticoid receptor but do not have glucocorticoid agonist activity. Such compounds will competitively bind to rip-1, but will not, in the cases where such compounds also bind to glucocorticoid receptors in the cells of the individual ungoing treatment for the HIV infection, produce the effects and activities of glucocorticoids, which may be undesirable over extended periods of time. For such agonists, the overall result will be dependent upon the initial dosage as well as the amount of compound which is bound to rip-1, not to mention the extent of binding to glucocorticoid receptors and resultant agonist activity in the individual involved. Thus, it is still within the scope of the present invention to use glucocorticoid agonists, although this is not preferred, and the choice of the type, i.e., glucocorticoid receptor agohist or antagonist, as well as of the specific compound, can be made in a straightforward manner using evaluation procedures well known in the art and described herein.
It is possible to identify compounds which have antiglucocorticoid activity by determining the effect of a candidate compound on the tyrosine amino-transferase enzyme. The test system is based on measurement of the activity of the liver enzyme tyrosine amino-transferase (TAT) in cultures of rat hepatoma cells (RHC). The enzyme catalyzes the first step in the metabolism of tyrosine and can be induced by glucorcorticoids both in the liver and in hepatoma cells. The activity is readily measured in raw extracts. TAT converts the amino group of tyrosine to 2-oxoglutaric acid, and p-hydroxyphenylpyruvate is also formed, which is converted to the more stable p-hydroxybenzaldehyde in alkaline solution. Its measured adsorption line lies at 331 nm. More details concerning this procedure may be found in Granner and Tomkins (1970) Meth. Enzymol. 15, 633.
In accordance with the present invention, a preferred group of glucocorticoid receptor antagonists are those to which mifepristone, better known as RU-486, belongs. This compound, 11β-(4-dimethylaminophenyl)-17β-hydroxy-17α-(propyl-1-ynyl)estra-4,9-dien-3-one, is a good glucocorticoid antagonist, which also has antiprogestin activity. Further details concerning this and related compounds may be found in Agarwal, M. K. et al. "Glucocorticoid antagonists" FEBS LETTERS 217, 221-226 (1987). Extensive work has been done over the years in synthesizing and testing glucocorticoid antagonists which belong to this group, and the published literature is an abundant guide for the selection of candidate compounds that fall within the scope of the present invention. The patent literature alone is substantial. Thus, reference is made to the following U.S. patents, all of which are incorporated herein by reference in their entirety: 4,296,206; 4,386,085; 4,447,424; 4,477,445; 4,519,946; 4,540,686; 4,547,493; 4,634,695; 4,634,696; 4,753,932; 4,774,236; 4,814,327; 4,829,060; 4,861,763; 4,912,097; 4,943,566; 4,954,490; 4,978,657; 5,006,518; 5,043,332; 5,064,822; 5,073,548; 5,089,488; 5,089,635; 5,093,507; 5,095,010; 5,095,129; 5,132,299; 5,166,146; and 5,276,023. Analysis of the patents set out above and the attendant technical literature reveals that the 11-position substituent, and particularly the size of that substituent, plays a key role in determining the antiglucocorticoid activity, although the character of the A ring is also important. It is also noted that a 17-hydroxypropenyl side chain generally decreases antiglucocorticoidal activity in comparison to the 17-propinyl side chain containing compounds, and that generally 9α, 10α-CH 2 groups decrease antiglucocorticoidal activity.
Action of vpr
The human immunodeficiency virus has been termed a complex retrovirus due to the fact that the HIV genome encodes six regulatory genes (tat, rev, vif, vpr, vpu, nef) in addition to the common gag, pol and env open reading frames found in all retroviruses. The complexity of HIV and its related lentiviruses can furthermore be attributed to the intricate patterns of regulation of gene expression observed during the vital lifecycle. All such regulatory mechanisms are accomplished by the interaction of virally encoded proteins with distinct host cell factors.
Many cellular proteins are needed for HIV gene expression during the infection process, e.g., the HIV tat gene has been shown to be a nondispensable regulatory gene responsible for the transactivation of the viral LTR. The vpr gene of HIV-1 encodes a 15 KD polypeptide. Vpr has a highly conserved nucleotide sequence among the different primate lentiviruses. All HIV-1 and HIV-2, as well as all pathogenic SIV isolates have a vpr gene. Vpr has several activities which are involved in HIV infection. See PCT application Ser. No. PCT/US 94/02191 (Docket No. 63); U.S. application Ser. No. 08/019,601 (Docket No. 3); and U.S. application Ser. No. 08/167,608 (Docket No. 8), each of which are incorporated herein by reference in their entirety. In particular, vpr is deemed to enhance retroviral infection by causing changes in cells that make them better hosts for HIV replication, all of which has been explained in detail further above in the section which describes the prior art.
Action of rip-1
The method of treating individuals infected with HIV in accordance with the present invention is based on the administration of compounds which prevent or inhibit the formation of the vpr/rip-1 complex and its translocation from the cytoplasm, i.e., cytosol, to the nucleus. Thus, an important aspect of the present invention is a procedure for obtaining essentially pure human rip-1. As already noted, rip-1 has an apparent molecular weight of between 40-43 KD and occurs in the cytoplasm of human cells, and unbound, is a cytosolic protein. When bound to vpr, the rip-1 protein forms a complex with vpr and the complex translocates from the cytoplasm to the nucleus. The rip-1 can be isolated from human cells by passing a human cell preparation through an immobilized vpr column under conditions which allow vpr/rip-1 binding, and then changing the conditions to those which do not favor such binding. The released rip-1 can be collected in essentially pure form. Further purification may be achieved using routine chromatography means.
The following procedure may be used to purify rip-1s. Cell extracts from primary T cells and monocytes as well as peripheral blood cells and macrophages are obtained by methods known to those skilled in the art. Cell extracts are separated by affinity chromatography. Briefly, eukaryotically-produced vpr is immobilized to a solid support matrix via one or more covalent bonds. Solid support matrices include agarose, polyacrylamide-agarose, controlled-pore glass and other such materials known to those skilled in the art. One skilled in the art will readily appreciate the standard techniques involved in coupling vpr to the matrix as well as techniques involved in activation of the matrix. A spacer molecule may be employed to distance vpr from the matrix backbone in order to allow vpr to more freely bind proteins in the cell extract. One skilled in the art will readily appreciate the variety of spacer molecules with which to use.
The cell extract is layered onto the vpr affinity column by standard methods known to those skilled in the art. Appropriate buffers, washing conditions and elution conditions, which are known to those skilled in the art, are chosen. The resulting eluate may be further purified to homogeneity by techniques such high performance liquid chromatography (HPLC) or other such methods as known to those skilled in the art.
The rip-1 has been purified to approximately 95% purity by a vpr-affinity column using this technique of purification. Said protein has a molecular weight of about 40-43 KD when separated by reducing SDS-PAGE. The protein has been detected in rhabdomyosarcoma cell lines TE 671 and RD; osteosarcoma cell lines D17 and HOS; glioblastoma cell lines HTB14, U373 and HBT10; as well as T-cell lines Supt-1 and H9 and monocyte/macrophage lines U937, THP-1, KG-1 and HL-60 as well as primary cells. Further details may be found in Examples 6 further below.
Techniques for the cloning of a protein are widely known to those skilled in the art. Briefly, a pure preparation of the 41 KD cellular protein that binds vpr (the rip-1) is sequenced by standard N-terminal sequencing techniques known to those skilled in the art. A set of oligonucleotide probes coding for the deduced amino acid sequence of the N-terminal portion of the rip-1 is designed by techniques known to those skilled in the art. This set of probes is used to screen a human cDNA library by techniques known to those skilled in the art. Positive plaques are selected and sequenced by methods such as dideoxy sequencing for the entire nucleotide sequence of the rip-1.
Alternatively, a pure preparation of the rip-1 may be injected into a mammal, such as a rabbit or mouse, resulting in the production of a polyclonal antiserum. Such immunization procedures are well known to those skilled in the art. In addition, plasma cells (antibody-producing B cells) may be isolated from the injected mammal and fused with myeloma cells to produce hybridomas which produce monoclonal antibodies. Additionally, recombinant antibodies can be produced by a variety of methods; and such methods are well known to those skilled in the art. The polyclonal antiserum may be used to screen a human cDNA expression library wherein cells expressing the rip-1 may be identified with the antiserum. Positive clones are selected and the DNA isolated and sequenced by methods known to those skilled in the art.
Once the complete nucleotide sequence of the rip-1 is known, the sequence, or any portion thereof, can be incorporated into a plasmid vector or any other vector capable of expressing the rip-1. In addition, mammalian cells as well as bacterial cells may be transformed with the plasmid construct containing the sequence, or derivatives thereof, encoding the rip-1. Said transformed cells may produce the rip-1 intracellularly or extracellularly. In addition, oligonucleotides corresponding to the portions of the sense or antisense of the rip-1 may also be produced. These oligonucleotides may comprises between 10 and 5000 nucleotides, preferably between 10 and 500 nucleotides, most preferably between 10 and 100 nucleotides.
The present invention thus involves a nucleic acid molecule that comprises a nucleotide sequence that encodes rip-1 or a fragment thereof; an expression vector that comprises such a nucleotide sequence; a host cell which comprises such an expression vector; a method of producing rip-1 or a fragment thereof comprising the step of culturing such a host cell.
Rip-1 may be produced by routine means using readily available starting materials as described above. Provision of a suitable DNA sequence encoding the desired protein permits the production of the protein using recombinant techniques now known in the art. The DNA sequence may also be obtained from other sources of HIV DNA or can be prepared chemically using a synthesized nucleotide sequence. When the coding DNA is prepared synthetically, advantage can be taken of known codon preferences of the intended host where the DNA is to be expressed.
One having ordinary skill in the art can, using well known techniques, obtain a DNA molecule encoding the rip-1 and insert that DNA molecule into a commercially available expression vector for use in well known expression systems. For example, the commercially available plasmid pSE420 (Invitrogen, San Diego, Calif.) may be used for production in E. coli. The commercially available plasmid pYES2 (Invitrogen, San Diego, Calif.) may be used for production in S. cerevisiae strains of yeast. The commercially available MaxBac™ (Invitrogen, San Diego, Calif.) complete baculovirus expression system may be used for production in insect cells. The commercially available plasmid pcDNA I (Invitrogen, San Diego, Calif.) may be used for production in may be used for production in mammalian cells such as Chinese Hamster Ovary cells. One having ordinary skill in the art can use these commercial expression vectors systems or others to produce rip-1 using routine techniques and readily available starting materials.
One having ordinary skill in the art may use other commercially available expression vectors and systems or produce vectors using well known methods and readily available starting materials. Expression systems containing the requisite control sequences, such as promoters and polyadenylation signals, and preferably enhancers, are readily available and known in the art for a variety of hosts. See e.g., Sambrook et al., Molecular Cloning a Laboratory Manual, Second Ed. Cold Spring Harbor Press (1989). Thus, the desired proteins can be prepared in both prokaryotic and eukaryotic systems, resulting in a spectrum of processed forms of the protein.
The most commonly used prokaryotic system remains E. coli, although other systems such as B. subtilis and Pseudomonas are also useful. Suitable control sequences for prokaryotic systems include both constitutive and inducible promoters including the lac promoter, the trp promoter, hybrid promoters such as tac promoter, the lambda phage Pl promoter. In general, foreign proteins may be produced in these hosts either as fusion or mature proteins. When the desired sequences are produced as mature proteins, the sequence produced may be preceded by a methionine which is not necessarily efficiently removed. Accordingly, the peptides and proteins claimed herein may be preceded by an N-terminal Met when produced in bacteria. Moreover, constructs may be made wherein the coding sequence for the peptide is preceded by an operable signal peptide which results in the secretion of the protein. When produced in prokaryotic hosts in this manner, the signal sequence is removed upon secretion.
A wide variety of eukaryotic hosts are also now available for production of recombinant foreign proteins. As in bacteria, eukaryotic hosts may be transformed with expression systems which produce the desired protein directly, but more commonly signal sequences are provided to effect the secretion of the protein. Eukaryotic systems have the additional advantage that they are able to process introns which may occur in the genomic sequences encoding proteins of higher organisms. Eukaryotic systems also provide a variety of processing mechanisms which result in, for example, glycosylation, carboxy-terminal amidation, oxidation or derivatization of certain amino acid residues, conformational control, and so forth.
Commonly used eukaryotic systems include, but is not limited to, yeast, fungal cells, insect cells, mammalian cells, avian cells, and cells of higher plants. Suitable promoters are available which are compatible and operable for use in each of these host types as well as are termination sequences and enhancers, as e.g. the baculovirus polyhedron promoter. As above, promoters can be either constitutive or inducible. For example, in mammalian systems, the mouse metallothionene promoter can be induced by the addition of heavy metal ions.
The particulars for the construction of expression systems suitable for desired hosts are known to those in the art. For recombinant production of the protein, the DNA encoding it is suitably ligated into the expression vector of choice and then used to transform the compatible host which is then cultured and maintained under conditions wherein expression of the foreign gene takes place. The protein of the present invention thus produced is recovered from the culture, either by lysing the cells or from the culture medium as appropriate and known to those in the art.
One having ordinary skill in the art can, using well known techniques, isolate the rip-1 or fragments thereof produced using such expression systems.
In addition to isolating rip-1 from natural sources and producing rip-1 or fragments thereof by recombinant techniques, automated amino acid synthesizers may also be employed to produce rip-1 or fragments thereof. It should be further noted that if the proteins herein are made synthetically, substitution by amino acids which are not encoded by the gene may also be made. Alternative residues include, for example, the ω amino acids of the formula H 2 N(CH 2 ) n COOH wherein n is 2-6. These are neutral, nonpolar amino acids, as are sarcosine (Sar), t-butylalanine (t-BuAla), t-butylglycine (t-BuGly), N-methyl isoleucine (N-MeIle), and norleucine (Nleu). Phenylglycine, for example, can be substituted for Trp, Tyr or Phe, an aromatic neutral amino acid; citrulline (Cit) and methionine sulfoxide (MSO) are polar but neutral, cyclohexyl alanine (Cha) is neutral and nonpolar, cysteic acid (Cya) is acidic, and ornithine (Orn) is basic. The conformation conferring properties of the proline residues may be obtained if one or more of these is substituted by hydroxyproline (Hyp).
Pharmaceutical Compositions and Methods of Treatment
The pharmaceutical compositions of the present invention comprise a therapeutically effective amount of a composition comprising one or more steroid hormone receptor antagonists, preferably glucocorticoid receptor antagonists, and more preferably glucocorticoid receptor Type II antagonists, which by binding to rip-1 or a fragment thereof, a glucocorticoid type molecule, prevents vpr from binding to rip-1, and thereby prevents translocation of the vpr/rip-1 complex from the cytosol to the nucleus of the infected cell, where vpr carries on its various activities essential to replication of HIV.
The pharmaceutical composition comprising the receptor antagonist which binds rip-1 or a fragment thereof and a pharmaceutically acceptable carrier or diluent may be formulated by one having ordinary skill in the art with compositions selected depending upon the chosen mode of administration. Suitable pharmaceutical carriers are described in the most recent edition of Remington's Pharmaceutical Sciences, A. Osol, a standard reference text in this field.
For parenteral administration, the receptor antagonist which binds rip-1 or a fragment thereof can be, for example, formulated as a solution, suspension, emulsion or lyophilized powder in association with a pharmaceutically acceptable parenteral vehicle. Examples of such vehicles are water, saline, Ringer's solution, dextrose solution, and 5% human serum albumin. Liposomes and nonaqueous vehicles such as fixed oils may also be used. The vehicle or lyophilized powder may contain additives that maintain isotonicity (e.g., sodium chloride, mannitol) and chemical stability (e.g., buffers and preservatives). The formulation is sterilized by commonly used techniques. For example, a parenteral composition suitable for administration by injection is prepared by dissolving 1.5% by weight of active ingredient in 0.9% sodium chloride solution.
The pharmaceutical compositions according to the present invention may be administered as a single doses or in multiple doses. The pharmaceutical compositions of the present invention may be administered either as individual therapeutic agents or in combination with other therapeutic agents. The treatments of the present invention may be combined with conventional therapies, which may be administered sequentially or simultaneously. In particular, the pharmaceutical compositions may comprise a therapeutically effective amount of one or more of said receptor antagonists, together with one or more therapeutic agents useful for treating HIV infected individuals, selected from the group consisting of zidovudine (AZT), acyclovir, ganciclovir, foscarnet, interferon alpha-2a, and interferon alpha-2b, together with a pharmaceutically acceptable carrier.
The pharmaceutical compositions described above may be administered by any means that enables the active agent to reach the agent's site of action in the body of a mammal. The dosage administered varies depending upon factors such as: pharmacodynamic characteristics; its mode and route of administration; age, health, and weight of the recipient; nature and extent of symptoms; kind of concurrent treatment; and frequency of treatment. Usually, a daily dosage of the receptor antagonist that binds rip-1 can be about 1 μg to 100 milligrams per kilogram of body weight. Ordinarily 0.01 to 50, and preferably 0.1 to 20 milligrams per kilogram per day given in divided doses 1 to 6 times a day or in sustained release form is effective to obtain desired results.
The present invention relates to a method for treating HIV infected individuals or individuals exposed to HIV, comprising administering to such individuals a therapeutically effective amount of a composition comprising one or more steroid hormone receptor antagonists, preferably glucocorticoid receptor antagonists, more preferably glucocorticoid receptor Type II receptor antagonists, which bind rip-1 and prevent vpr from binding to rip-1, and thereby prevent translocation of the vpr/rip-1 complex from the cytosol to the nucleus of the infected cell, where vpr carries on its various activities essential to replication of HIV.
The present invention also relates to such a method of treating HIV infected individuals as described above, wherein there is coadministered with one or more of said receptor antagonists, one or more therapeutic agents useful for treating HIV infected individuals, selected from the group consisting of zidovudine (AZT), acyclovir, ganciclovir, foscarnet, interferon alpha-2a, and interferon alpha-2b.
Identifyiny Compounds which Bind rip-1
The present invention also relates to a method of identifying such compounds which inhibit or prevent replication of HIV by interfering with the replicative or other essential functions of vpr by competitively binding to the vpr target in human cells, rip-1, said compounds comprising glucocorticoid receptor (GR) antagonists, which by binding to rip-1, a GR type molecule, prevents vpr from binding to rip-1. This method of identifying compounds which inhibit vpr binding to rip-1 comprises the steps of (1) determining glucocorticoid antagonist activity of a test compound by determining the effect of said test compound on tyrosine amino-transferase in accordance with the method of Granner and Tompkins, (1970) Meth. Enzymol. 15, 633; and if said test compound exhibits glucocorticoid antagonist activity, (2) contacting vpr and rip-1 or a fragment thereof in the presence of said test compound, determining the level of binding and comparing that level to the level of binding that occurs when vpr and rip-1 are contacted in the absence of said test compound. Compounds which are thus identified, interfere with the binding of vpr to rip-1, and are thus useful to impede HIV replication; therefore such compounds will be useful as anti-HIV therapeutics alone or as part of a multi-faceted anti-HIV drug regimen which includes other therapeutics.
To practice these aspects of the invention, once a test compound has been found to be a glucocorticoid receptor antagonist, vpr protein and rip-1 are contacted in the presence of said test compound. The level of binding of the proteins is determined. The resultant level of binding is compared to the known level of binding that occurs when both proteins are contacted with each other in the absence of a test compound. In the absence of a compound that interferes with the binding, the two proteins will bind. As a control, vpr protein and rip-1 are contacted in the absence of a test compound.
Test compound is provided, preferably in solution. Serial dilutions of test compounds may be used in a series of assays. Test compound may be added at concentrations from 0.01 μM to 1M. A preferred range of final concentrations of a test compound is from 10 μM to 100 μM.
Production of vpr protein is described in the U.S. patent applications cited above which have been incorporated by reference. A preferred concentration range of the vpr used is about 1 μg/ml to 1 mg/ml. A preferred concentration of the vpr is about 50 μg/ml.
The rip-1 may be produced by routine means using readily available starting materials following the teachings described herein. A preferred concentration range of the rip-1 used is about 1 μg/ml to 1 mg/ml. A preferred concentration of the rip-1 is about 50 μg/ml.
The means to detect whether or not vpr and rip-1 are bound, or if binding has been inhibited, are routine and include enzyme assays and ELISA assays. One having ordinary skill in the art can detect protein binding using well known methods. One having ordinary skill in the art can readily appreciate the multitude of ways to practice a binding assay to detect compounds which modulate the binding of vpr to rip-1. For example, antibodies are useful for immunoassays which detect or quantirate vpr protein binding to rip-1. The immunoassay typically comprises incubating vpr protein and rip-1 to allow protein-protein binding in the presence of a detectably labeled high affinity antibody capable of selectively binding to either vpr protein or rip-1, and detecting the labeled antibody which is bound to the protein. Various immunoassay procedures are described in Immunoassays for the 80's, A. Voller et al., Eds., University Park, 1981.
In this aspect of the invention, the antibody or either vpr protein or rip-1 may be added to nitrocellulose, or other solid support which is capable of immobilizing proteins. The support may then be washed with suitable buffers followed by treatment with the detectably labeled vpr-specific antibody or the antibody that binds to the rip-1. The solid phase support may then be washed with the buffer a second time to remove unbound antibody. The amount of bound label on said solid support may then be detected by conventional means.
By "solid phase support" or "carrier" is intended any support capable of binding antigen or antibodies. Well-known supports or carriers, include glass, polystyrene, polypropylene, polyethylene, dextran, nylon, amylases, natural and modified celluloses, polyacrylamides, agaroses, and magnetite. The nature of the carrier can be either soluble to some extent or insoluble for the purposes of the present invention. The support configuration may be spherical, as in a bead, or cylindrical, as in the inside surface of a test tube, or the external surface of a rod. Alternatively, the surface may be flat such as a sheet, test strip, etc. Those skilled in the art will know many other suitable carriers for binding antibody or antigen, or will be able to ascertain the same by use of routine experimentation.
The binding activity of a given lot of antibodies may be determined according to well known methods. Those skilled in the art will be able to determine operative and optimal assay conditions for each determination by employing routine experimentation.
Positive control assays may be performed in which no test compound is added.
One of the ways in which the antibodies can be detectably labeled is by linking the same to an enzyme and use in an enzyme immunoassay (EIA), or enzyme-linked immunosorbent assay (ELISA). This enzyme, when subsequently exposed to its substrate, will react with the substrate generating a chemical moiety which can be detected, for example, by spectrophotometric, fluorometric or by visual means. Enzymes which can be used to detectably label the antibody include, but are not limited to, malate dehydrogenase, staphylococcal nuclease, delta-5-steroid isomerase, yeast alcohol dehydrogenase, alpha-glycerophosphate dehydrogenase, triose phosphate isomerase, horseradish peroxidase, alkaline phosphatase, asparaginase, glucose oxidase, beta-galactosidase, ribonuclease, urease, catalase, glucose-6phosphate dehydrogenase, glucoamylase and acetylcholinesterase.
By radioactively labeling the antibody, it is possible to detect it through the use of a radioimmunoassay (RIA) (see, for example, Work, T. S., et al., Laboratory Techniques and Biochemistry in Molecular Biology, North Holland Publishing Company, N.Y., 1978. The radioactive isotope can be detected by such means as the use of a gamma counter or a scintillation counter or by autoradiography. Isotopes which are particularly useful for the purpose of the present invention are: 3 H, 125 I, 131 I, 35 S, 14 C, and, preferably, 125 I.
It is also possible to label the antibody with a fluorescent compound. When the fluorescent labeled antibody is exposed to light of the proper wave length, its presence can then be detected due to fluorescence. Among the most commonly used fluorescent labelling compounds are fluorescein isothiocyanate, rhodamine, phycoerythrin, phycocyanin, allophycocyanin, o-phthaldehyde and fluorescamine.
The antibody can also be detectably labeled using fluorescence-emitting metals such as 152 Eu, or others of the lanthanide series. These metals can be attached to the TNF-specific antibody using such metal chelating groups as diethylenetriaminepentaacetic acid (DTPA) or ethylenediaminetetraacetic acid (EDTA).
The antibody also can be detectably labeled by coupling to a chemiluminescent compound. The presence of the chemiluminescently labeled antibody is then determined by detecting the presence of luminescence that arises during the course of a chemical reaction. Examples of particularly useful chemiluminescent labeling compounds are luminol, isoluminol, theromatic acridinium ester, imidazole, acridinium salt and oxalate ester.
Likewise, a bioluminescent compound may be used to label the antibody. Bioluminescence is a type of chemiluminescence found in biological systems in which a catalytic protein increases the efficiency of the chemiluminescent reaction. The presence of a bioluminescent protein is determined by detecting the presence of luminescence. Important bioluminescent compounds for purposes of labeling are luciferin, luciferase and aequorin. Detection of the vpr-specific antibody or the antibody that binds to the rip-1 may be accomplished by a scintillation counter, for example, if the detectable label is a radioactive gamma emitter, or by a fluorometer, for example, if the label is a fluorescent material.
In the case of an enzyme label, the detection can be accomplished by colorometric methods which employ a substrate for the enzyme. Detection may also be accomplished by visual comparison of the extent of enzymatic reaction of a substrate in comparison with similarly prepared standards.
As can be readily appreciated, one of the viral proteins may also be detectable and serve as a reporter molecule instead of or in addition to the antibody.
The components of the assay may be adapted for utilization in an immunometric assay, also known as a "two-site" or "sandwich" assay. In a typical immunometric assay, a quantity of unlabeled antibody (or fragment of antibody) is bound to a solid support that is insoluble in the fluid being tested and a quantity of detectably labeled soluble antibody is added to permit detection and/or quantitation of the ternary complex formed between solid-phase antibody, antigen, and labeled antibody.
Typical and preferred immunometric assays include "forward" assays in which the antibody bound to the solid phase is first contacted with the one of the viral proteins to immobilize it. The second vital protein is added in the presence of the test compound. After a suitable incubation period, the solid support is washed to remove unbound protein. A second antibody is then added which is specific for the second vital protein. The second antibody is preferably detectable. After a second incubation period to permit the labeled antibody to complex with the second viral protein bound to the solid support through the unlabeled antibody and first viral protein, the solid support is washed a second time to remove the unreacted labeled antibody. This type of forward sandwich assay may be a simple "yes/no" assay to determine whether binding has occurred or may be made quantitative by comparing the measure of labeled antibody with that obtained in a control. Such "two-site" or "sandwich" assays are described by Wide, Radioimmune Assay Method, Kirkham, Ed., E. & S. Livingstone, Edinburgh, 1970, pp. 199-206).
Other type of "sandwich" assays are the so-called "simultaneous" and "reverse" assays. A simultaneous assay involves a single incubation step wherein the antibody bound to the solid support and labeled antibody, both viral protein and the test compound are added at the same time. After the incubation is completed, the solid support is washed to remove uncomplexed proteins. The presence of labeled antibody associated with the solid support is then determined as it would be in a conventional "forward" sandwich assay.
In the "reverse" assay, stepwise addition first of a solution of labeled antibody to the viral proteins followed by the addition of unlabeled antibody bound to a solid support after a suitable incubation period, is utilized. After a second incubation, the solid phase is washed in conventional fashion to free it of the residue of the sample being tested and the solution of unreacted labeled antibody. The determination of labeled antibody associated with a solid support is then determined as in the "simultaneous" and "forward" assays. In one embodiment, a combination of antibodies of the present invention specific for separate epitopes may be used to construct a sensitive three-site immunoradiometric assay.
In some preferred embodiments, an anti-vpr antibody is fixed to a solid phase. Vpr protein is contacted with the fixed antibody to form a complex. The complex is contacted with a rip-1 in the presence of a test compound. Antibodies that bind to the rip-1 are then added. The solid phase is washed to removed unbound material. A control assay is performed in an identical manner except that no test compound is used. Detection of the antibodies that bind to the rip-1 indicates that the vpr and rip-1s are capable of binding to each other in the presence of the test compound. Accordingly, failure to detect that antibodies that bind to vpr protein indicates that the test compound inhibits binding of vpr and rip-1s. Quantifying the level of binding in the presence and absence of test compound allows for the measurement of the extent of modulation that the test compound can cause on vpr binding to rip-1.
In some preferred embodiments, antibodies that bind to the rip-1 are fixed to a solid phase. Rip-1 is contacted with the fixed antibody to form a complex. The complex is contacted with vpr protein in the presence of a test compound. Anti-vpr antibodies are then added. The solid phase is washed to removed unbound material. A control assay is performed in an identical manner except that no test compound is used. Detection of the antibodies that bind to vpr protein indicates that the vpr and rip-1s are capable of binding to each other in the presence of the test compound. Accordingly, failure to detect that antibodies that bind to vpr protein indicates that the test compound inhibits binding of vpr and rip-1s. Quantifying the level of binding in the presence and absence of test compound allows for the measurement of the extent of modulation that the test compound can cause on vpr binding to rip-1.
In the methods of identifying compounds that inhibit vpr protein binding to rip-1, fragments of vpr may be used provided the fragment used retains its ability to bind to the rip-1. Similarly, fragments of rip-1 may be used provided the fragment used retains its ability to bind to vpr protein.
A further aspect of the present invention relates to kits for practicing the above described method of identifying compounds which are glucocorticoid receptor antagonists and which inhibit vpr protein binding to rip-1. Kits according to this aspect of the invention comprises a first container comprising tyrosine amino-transferase, a second container comprising vpr protein, and a third container comprising rip-1. Additionally, to practice the above defined method, means are required to distinguish vpr protein bound to the rip-1 from unbound vpr protein or unbound rip-1. In a preferred embodiment of this aspect of the invention, a fourth container comprising an antibody that specifically binds to either the vpr protein or rip-1 is provided. At least one of the contained components, preferably the antibody, may be conjugated with an agent, such as those described above, which allows its presence to be detected. In another preferred embodiment of this aspect of the invention, a fourth container is provided which contains an antibody that specifically binds to either the vpr protein or rip-1, but not the protein which is bound by the antibody in the third container. At least one of the contained components, preferably the antibody, may be conjugated with an agent, such as those described above, which allows its presence to be detected. In the kits of the invention which are useful to practice the methods of identifying compounds that inhibit vpr protein binding to a protein, fragments of vpr may be included provided the fragment used retains its ability to bind to the rip-1. Similarly, fragments of rip-1 may be included, provided the fragment used retains its ability to bind to vpr protein.
The present invention involves the use of antibodies that specifically bind to rip-1. Production of such antibodies can be achieved by those having ordinary skill in the art without undue experimentation using readily available starting materials. The antibodies are useful in the assay to identify compounds that inhibit vpr binding to rip-1, described above.
Another aspect of the invention relates to methods of identifying compounds which bind to rip-1, but which do not translocate to the nucleus as a complex with said receptor. By binding to rip-1 but not translocating, the compounds inhibit vpr activity by competing with vpr for rip-1 receptor binding, while not being active once bound. As used herein, such compounds which bind to the rip-1 to form a complex that does not translocate, are deemed vpr receptor antagonists. Compounds which form complexes with the rip-1 that do not translocate into the nucleus are useful to impede HIV replication; therefore such compounds will be useful as anti-HIV therapeutics alone or as part of a multi-faceted anti-HIV drug regimen which includes other therapeutics.
EXAMPLES OF PREFERRED EMBODIMENTS
EXAMPLE 1
Expression and Purification of Recombinant HIV-1 vpr
The expression and purification of HIV-1 vpr expressed in insect cells was carried out. The vpr open reading frame from HIV-1 NL 43 was cloned into the baculovirus expression vector pVL1393. This construct was subsequently cotransfected into Spodoptera fungupeida (sf-9) cells with linearized DNA from Autograph California nuclear polyhidrosis virus (Baculogold-AcMNPV). The recombinant baculoviruses obtained were subsequently plaque purified and expanded following published protocols.
Recombinant vpr was produced by the following procedures. High five cells were infected at 5-10 MOI, and a cell density of 2×10(6) cells/mi. The tissue culture supernatants were harvested 24 hours later. These were centrifuged at 10000 g and supplemented with a protease inhibitor cocktail (PMSF, EDTA, EGTA, aprotinin, pepstatin A, and Leupetin. All supernatants were kept on ice until use.
The above-described supernatants were passed over a rabbit anti vpr affinity column constructed following published procedures. The elution scheme consisted of preelution with 100 mM Phosphate buffer, pH 8.0, followed by the elution buffer: 100 mM triethanolamine, pH 11.5. The eluate was collected in 0.5 ml aliquots and neutralized with 1/20 of the total fraction volume of 1M sodium phosphate, pH 6.8. These fractions were monitored for protein concentration, and were further analyzed by ELISA, silver stain, and western blot.
EXAMPLE 2
Vpr Antibodies
The rabbit anti-vpr peptide 2-21 (808) was obtained from NIH, AIDS RR. All the other antibodies used were made as described in published procedures. These antibodies are LR1, a rabbit anti-vpr. This serum was obtained by immunizing an animal with the purified, recombinant vpr described further above. A mouse anti-vpr was also used, raised against the same antigen. Mouse antisera to vpr peptide 2-21, is denoted as m. anti pl; mouse antisera to vpr peptide 90-96 is denoted as m. anti p3. Another mouse antisera was obtained to vpr peptide 41-48; this is denoted as m. anti p2. All of these sera were titered by ELISA, and tested for their crossreactivities with peptides and recombinant vpr prior to use.
EXAMPLE 3
Enzyme Linked Immunosorbent Assays (ELISAs)
Three different variations of the ELISA technique were used. A solid phase approach was the one used, unless otherwise noted. A capture ELISA system, and a protein/peptide blocking ELISA were also used.
The solid phase ELISA was done by immobilizing protein on the plates (Immulon II plates, Dynatech Corp.) at a concentration of 1 μg/ml, diluted in a 0.2M carbonate bicarbonate solution, pH 9.2. Peptides were used at a concentration of 10 μg/ml dissolved in the same buffer. The wash buffer consisted of 1X PBS, with 0.05% Tween-20. The blocking buffer consisted of 2% BSA in the washing buffer. All of the antibodies were diluted in blocking buffer. The detection antibodies used were goat anti mouse, rabbit, or human Ig specific antibody, conjugated to horse radish peroxidase, (Boehringer Mannheim). These were used at a 1:12000 dilution, following manufacturer's specifications. The substrate used was 3,3',5,5' tetramethylbenzidine dihydrochloride (TMB Sigma), following manufacturer's specifications. The plates were developed for 15 minutes at room temperature in the dark. The reaction was stopped by adding 20 μl/well of 3M sulfuric acid, and read at OD 450 nm.
In the capture ELISA method, antibody diluted in carbonate bicarbonate buffer at 1 μg/ml is immobilized on the plate for two hours at 25° C. The samples are diluted in blocking buffer. All remaining steps were as described above.
The peptide blocking assay was performed by immobilizing one of the proteins of interest on the plate at a dilution of 1 μg/ml in carbonate bicarbonate. The peptides were dissolved in the blocking buffer at a dilution of 50 μg/ml, and added onto blocked wells. The second protein of interest is applied to these wells at a dilution of 1 μg/ml in the blocking buffer. The antibodies used from this point on are targeted toward the second protein, following the procedure described further above.
EXAMPLE 4
SDS-PAGE and Western Blot
SDS polyacrytamide gels were made following published procedures. Silver staining was performed using the Bio Rad Silver Stain Kit, following manufacturer's instructions.
Transfer of proteins from SDS-PAGE gels onto Immulon-P membranes (Millipore Corp.) was performed using the Bio Rad mini gel transfer system, following manufacturer's specifications. The blocking buffer used was 5% nonfat dry milk dissolved in the wash buffer (1x TBS supplemented with 0.05% Tween-20). The antibodies were diluted in the blocking buffer. The detection probe used was I 125 labeled protein G (Dupont-NEN), diluted to 2 μci/ml in the wash buffer.
EXAMPLE 5
Vpr Multi-step Western Blot System
Six 3×10 cells were washed twice in DPBS, and lysed in 200 μl of lysis buffer (100 mM NaCl, 50 mM Tris, pH 8.0, 0.5% Triton X-100, and the protease inhibitor cocktail described further above); incubated on ice for 10 minutes; and centrifuged at 12000 g for 6 minutes.
The triton soluble, as well as the triton insoluble fractions were run on 12% SDS-PAGE, and blotted on to an Immulon-P membrane (Millipore corp.). These membranes were blocked with 5% NFDM in 1x TBS (8 g NaCl, 0.2 g KCl, 3 g Tris base, in 1 liter, pH 7.4) with 0.05% tween-20. The membranes were incubated with either column purified recombinant vpr (approximately 50 mg/ml), or an identical preparation, except for the presence of the vpr protein. The following incubation was done using 808, a rabbit anti-vpr antisera, followed by Iodinated protein G. (Dupont-NEN). These filters were dried and exposed to film (KODAK X-AR) at -80° C., for at least 12 hrs, with an intensifying screen.
When the source of vpr used was tissue culture supernatant from chronically infected H9 cells, the following procedure was followed. H9 cells which had been chronically infected with HIV-I MN were grown to confluence. These supernatants were collected by centrifuging the cells at 1000 g for 10 minutes. The tissue culture supernatants were then diluted 1:10 in the lysis buffer described earlier, and supplemented with the above-mentioned protease inhibitors. This preparation was then employed in the step where recombinant vpr had been used before. The control used in these experiments was tissue culture supernatants from uninfected H9 cells, grown to the same level of confluence, and treated with the same lysis conditions.
EXAMPLE 6
Cell and Virus Culture
The following cell lines were obtained from the American Type Culture Collection: the TE 671 rhabdomyosarcoma line (ATCC HTB 139), as well as A673 rhabdomyosarcoma line (ATCC CRL 1598); the canine osteosarcoma cell line D17 (ATCC CCL 183) and the human osteosarcoma line HOS (ATCC CRL 1543); the glial blastoma line U373 (ATCC HTB17) and the Neuroblatoma line HTB10 (ATCC SK-N-MC). Two additional glial blastoma lines were provided by the MRC (HTB17 and HTB16). U87MG is a glial cell line obtained from the University of Pennsylvania Cell Center. RD rhabdomyosarcoma cells were obtained from another source. The t-lymphocytic cells used (H9, Supt-1) were obtained from the University of Pennsylvania Cell Center. THP-1 monocytic cells were obtained through the MRC. HL60 and U937 cells were obtained from another source; and KG-1 was obtained from still another source. The three monkey kidney cells used (BSC1, CV-1, and COS) were obtained from a different source. The murine NIH 3T3 was obtained from the ATCC; and the B cell hybridoma, NIH 183 was obtained from AIDS RR. The primary PBL as well as monocytes/macrophages were isolated from freshly drawn blood, from a normal individual, following published protocols. All of the adherent cells from the prior list were cultured in DMEM supplemented with 10% heat inactivated fetal calf serum, penicillin/streptomycin, 1-glutamine, Hepes and sodium pyruvate. The suspension cultures were cultured in RPMI 1640, supplemented with the same reagents. All these cells were cultured every four days, diluting them 1:10.
The virus containing supernatants were obtained from chronically infected H9 cells. These isolates (HIV-I MN, and HIV-I NL43) were obtained from the AIDS Reagent Repository program. The infected cells were grown to confluence, the cells were then removed by centrifugation and the supernatants diluted in lysis buffer described further above. Infection of H9 target cells was constantly monitored by measuring the levels of p24 in tissue culture supernatant.
EXAMPLE 7
Column Chromatography
The immunoaffinity columns used were constructed following published protocols. The desired antibodies were covalently coupled to protein A beads using DMP. These columns were loaded with the desired protein suspensions, and eluted with the strategy described further above.
A vpr-CnBr activated Sepharose column was also used. This column was made by dissolving the CnBr activated sepharose beads (Sigma) in 1 mM HCl, and allowed to swell for 10 minutes. These beads were washed with 20 bed volumes 0.1 M NaHCO(3), 0.5M NaCl, pH 8.3. Recombinant vpr was dissolved in the same wash buffer to a final concentration of 1 mg/ml, and incubated with the beads for 2 hours at room temperature. The coupled beads were blocked with 1M glycine in the same wash buffer, pH 8.5, for two hours at room temperature. This column was eluted with a preelution buffer composed of 10 mM sodium phosphate, pH 6.8, followed by the elution buffer; 100 mM glycine, pH 2.5. These fractions were neutralized with 1/20 volume 1M sodium phosphate, pH 8.0.
EXAMPLE 8
Crosslinking of the Vpr/rip-1 Complexes
Vpr/rip-1 complexes were obtained using the column chromatography system described further above. Briefly, recombinant vpr was run on the column, followed by the Triton X-100 cell lysates, soluble fraction. These fractions were pooled and dialyzed against three changes of water. The resulting supernatant was lyophilized and resuspended in PBS to a tenth of the original volume. This solution was exposed to crosslinking agents. The crosslinkers used were DSS (Pierce), and DTSSP (Pierce). The latter is cleavable with reducing agents, DSS is a nonreversible crosslinker. Both of these agents needed to be dissolved at 50 mg/ml, in a 50% V/V water: DMSO mixture.
The resulting crosslinked fractions were run on 12% SDS-PAGE, either a reducing, or a non-reducing gel, and analyzed by the multi-step western blot method. Nonreducing gels were identical to their reducing counterparts, except for the presence of 2-beta mercaptoethanol and DTT in the loading buffer. These were denaturing gels, so they did contain SDS.
EXAMPLE 9
Mapping of the Vpr/rip-1 Interaction
The approach used to determine the sites of this interaction was a peptide-blocking ELISA system. Briefly, rbp-1 was immobilized on ELISA plates (Immulon II, Dynatech Corp.), dissolved at approximately 1 μg/ml in a 0.2M carbonate bicarbonate buffer, pH 9.2. The vpr peptides were dissolved in blocking buffer at 50 μg/ml, and incubated in the wells, using 50 μl/well. These are overlapping peptides, which span the entire length of the vpr molecule (obtained from the French AIDS Programme through the MRC repository, UK), the amino acid sequences of which are described in detail in Human Retroviruses and AIDS 1991, A Compilation and Analysis of Nucleic Acid and Amino Acid Sequences, G. Myers et al., eds., Division of AIDS, National Institute of Allergy and Infectious Diseases, published by Theoretical Biology and Biophysics Group T-10, Los Alamos National Laboratory, Los Alamos, N.M. Vpr was dissolved in blocking buffer at approximately 1 μg/ml. Different anti-vpr antibodies were used to detect the amount of vpr bound to the plates. Detection was accomplished by the use of a goat antiserum to mouse, or rabbit IgG, respectively, conjugated to horseradish, peroxidase.
In accordance with the above examples, it was found that the recombinant vpr protein migrated predominantly as a putative monomer at 15 KD on SDS PAGE. The silver staining, and the western blot also revealed the presence of a possible homodimer at 30 KD, at a lower concentration than the monomer. This protein was identical to native protein in its SDS-PAGE migration characteristics as well as in its antibody reactivity patterns.
Immunoaffinity chromatography was used as a means of obtaining protein which was >80% pure. It was observed that most of this purified protein migrates as a 15 KD band. Approximately 20% of the total protein present migrated as a high molecular weight compound, approximately 65 KD, which did not react with vpr specific antibodies in western blots.
Regarding recognition of rip-1 in cell lysate, the cell lysates were obtained by using different detergents in the lysis buffer. The detergents used were either Triton X-100, SDS, sodium deoxycholic acid, or a solution containing all three detergents (SDS, Triton X-100, and sodium deoxycholic acid). These lysis buffers were used to lyse 3×10(6) RD cells/sample.
The multi-step western blots showed a band at approximately 41 KD which hybridized in the Triton X-100 soluble portion, but not in the insoluble fraction. The same band hybridized in the other detergent lysates, but the subcellular localization could not be determined, as these detergents solubilized all cellular membranes. When native vpr was used in the multistep western blot system, instead of the recombinant protein described, the same 41 KD band hybridized. No additional bands were observed in this case either.
It was found that rip-1 expressed in an ubiquitous fashion in cell lines derived from T lymphocytes (H9, SupT-I), both cell lines, and primary cells, monocytes/macrophages (HL60, U937, THP-1, KG-1), from cell lines as well as primary cells, glial cells (HTB14, HTB10, U373), osteosarcoma cells (D17, HOS), rhabdomyosarcoma cells (RD, TE671, A673). All of these cells had rip-1 in their Triton X-100 soluble portions. The cell lines in which rip-1 was not detected were COS, BSC-1, CV-1, NIH 3T3, and a mouse derived B-cell hybridoma (NIH 183). Rip-1 was present in all the human cell lines that were screened, and in a canine osteosarcoma cell line (D17).
Regarding detection of rip-1 by column chromatography; when either RD lysates, or later on, U937 lysates were run on an anti-vpr column, following recombinant vpr, it was observed that a different elution profile than that which was obtained when vpr was run alone on the same column. Vpr will elute as one sharp peak, spanning about 5 fractions. Vpr followed by a cell lysate will yield a bimodal elution curve. These fractions will all have vpr activity, but this activity, when detected using a capture ELISA system, can sometimes block certain antibodies. The vpr detection/activity can ultimately be restored when a detection antibody which maps to a different region of vpr is used.
An analysis was done of the elution profiles, and their respective ELISA activities for different antibodies, in solid phase ELISA, and for different antibody combinations for a capture ELISA system. A mouse anti vpr (91-96) peptide was blocked in a capture ELISA system from the fractions in which vpr is associated with rbp-1. When a mouse anti-vpr (1-22) antibody is used in combination with a polyspecific rabbit antisera in a capture ELISA system, the presence of vpr is confirmed in both sets of fractions. This suggests that vpr is complexed with rip-1 such that it excludes the carboxy-terminus specific antibody from the reaction.
The multi-step western blot reactivity of these fractions showed a 41 KD band, in addition to vpr. This band correlates to that which was seen earlier with the whole cell lysates, and when run side by side to each other, appeared identical. Hence it was concluded that rip-1 had been isolated, bound to vpr in the column chromatography system.
With regard to isolation of rip-1, it was isolated by means of the vpr-CnBr activated Sepharose column. The Triton X-100 cellular lysates' soluble portion were incubated with this column for two hours at 4° C. This column was washed with 50 bed volumes of the adequate wash buffer, and eluted. The samples were analyzed by SDS-PAGE, silver staining, and western blot, as well as by their ability to bind vpr in ELISA. The column initially yielded some vpr in the first four fractions, which coeluted with rip-1. Upon additional strippings, the resulting fractions only contained rip-1. This was the source for >95% pure rip-1 used in the mapping studies described further above and commented on further below.
With regard to crosslinking of the vpr/rip-1 complexes, two crosslinking reagents were used, a cleavable (DSS), and a noncleavable (DTSSP) one. The noncleavable crosslinker, DSS, is a homobifunctional agent, which will covalently couple proteins found at a close proximity. DTSSP is a thiol cleavable crosslinker. These two chemical crosslinking agents are identical in every aspect other than their reversibility. A 58 KD band was detected on SDS-PAGE, by silver staining. This molecule reacted with anti-vpr antisera as well as in the multi step western blot system, like vpr, and rip-1 would react, individually. The DSS crosslinked complexes were run side by side with the DTSSP crosslinked complexes, to the undisturbed column fractions. These were run on both, reducing and nonreducing SDS-PAGE. The purpose of this was to observe the separation of the crosslinked complexes into its specific components, vpr and rip-1. Analysis showed a gel in which the 58 KD band was observed in the nonreducing gel, for both crosslinkers, whereas in the reducing gel, it could be seen that the 58 KD band was in the DSS lane only, and the 41 KD plus the 15 KD band, corresponding to vpr and rip-1, were in the DTSSP lane, as could be seen in the unaltered column fraction lane.
With regard to mapping of the vpr/rip-1 interaction, there was obtained 14 overlapping peptides from the French AIDS research program. A peptide blocking ELISA system was used in order to determine the site, on the vpr molecule, in which rip-1 binds vpr. The area of this interaction was resolved to amino acids x to y. This is consistent with the pattern of antibody blocking of this interaction, as the m. anti p2 antibody blocked this interaction; but other antibodies, raised against the amino, and the carboxy termini, did not give this result.
With regard to rip-1 translocation to the nucleus in response to vpr stimuli, U937 cells were used in order to explore the effects of vpr on rip-1 in vivo. These myeloid cells were either infected with HIV-1 NL43, or infected with a vpr deleted HIV-1 NL43; in the presence, or absence of recombinant vpr protein. U937 cells were also exposed to PMA, or to recombinant, soluble vpr alone. The effects of vpr on the cellular localization of rip-1 were assessed with the multistep western blot system. In addition, the infections were monitored by measuring the supernatant levels of gag p24. These experiments were carried out as a time course, collecting samples at 12, 24, 48, 72, 96, and 120 hours postinfection.
In each case in which the cells were exposed to soluble vpr, the multistep western blot showed vpr in the cytoplasmic cellular fraction at 12 hrs, and subsequently in both, the cellular and nuclear fractions. Rip-2 was always seen colocalizing with vpr. It was also observed that a translocation of vpr and of rip-1 from the cytoplasmic fractions to the nuclear fractions occurred. The phorbol ester PMA did not induce this translocation, and neither did a vpr deleted HIV virus. The translocation effect was rescued in the case of the vpr deleted virus upon the addition of recombinant vpr to the infected cultures. Other methods in addition to multistep western blot may be employed to demonstrate this nuclear colocalization of vpr and rip-1, such as the ELISA techniques described herein.
The levels of p24, which reflect a productive HIV infection, were measured. There was detected p24 in the supernatants of the HIV-I NL43 infected cultures at 96 hours postinfection. There was no detection of any p24 in the supernatants of the vpr deleted HIV NL43 infected cultures in the 120 hours that were analyzed. In addition, there was no detection of any p24 in the culture supernatants of the cells which were exposed to PMA, or to recombinant vpr only. The cultures which were exposed to both, recombinant vpr, and the vpr deleted virus, showed p24 at 48 hours postinfection. In addition, these cultures showed the same rip-1 translocation profile as the cultures exposed to recombinant vpr only. In all the cases in which p24 was detected in the supernatant, the translocation of rip-1 from the cytoplasm to the nucleus was observed up to 24 hours beforehand. | Human and simian immunodeficiency viruses (HIV/SIVs) contain, in addition to the canonical gag/pol/env genes, additional small open reading frames (ORFs) encoding gene products, including the 96-amino acid 15-kDa virion-associated HIV-1 Vpr gene product. Vpr functions as a regulator of cellular processes related to HIV replication. A biologically active recombinant HIV-1 Vpr protein was employed as a ligand to identify its cognate cellular target(s). A novel 41-kDa cytosolic viral protein R interacting protein, designated Rip-1, was identified using the recited assay. Rip-1 displays a wide-tissue distribution, including relevant targets of HIV infection. HIV-1 Vpr induced nuclear translocation of Rip-1. This invention provides novel biochemical reagents and methods that will facilitate the identification of antiviral agents. | 2 |
[0001] The present invention concerns a method and an arrangement for impregnating chips during the manufacture of chemical pulp, according to the preamble of claim 1 and claim 9 .
THE PRIOR ART
[0002] During the cooking of chemical cellulose pulp with continuous digesters it has been conventional to use a pretreatment arrangement with a chip bin, steaming vessel and an impregnating chip chute, before the cooking process is established in the digester. Steaming has been carried out in one or several steps in the chip bin, prior to the subsequent formation of a slurry of the chips in an impregnation fluid or a transport fluid. The steaming has been considered to be absolutely necessary in order to be certain of expelling the air and water that is bound in the chips, such that the impregnation fluid can fully penetrate the chips, and such that air is not drawn into the system. For example, U.S. Pat. No. 3,330,088 demonstrates the principle of such a system with a chip bin and a subsequent steaming vessel.
[0003] A great deal of development has taken place in order to optimise the steaming processin the chip bin, of which CA1154622, U.S. Pat. No. 6,199,299 and U.S. Pat. No. 6,284,095 only constitute examples of such development.
[0004] Attempts have been made to integrate the chip bin with the impregnation vessel in order to obtain in this manner a simpler system.
[0005] Already in U.S. Pat. No. 2,803,540, a system was revealed in which the chips from a chip bin were fed to a vessel in which a combined steaming and impregnation was achieved. In this vessel, the chips were steamed at the upper part of the vessel and impregnation fluid at the same temperature was added at various levels in the vessel.
[0006] These principles were applied in a process known as “Mumin cooking”, which is described in “Continuous Pulping Processes”, Technical Association of the Pulp and Paper Industry, 1970, Sven Rydholm, page 144. In this process, unsteamed chips were passed to a combined impregnation vessel, where steaming was obtained in the upper part, and to which impregnation fluid was added at a point in the upper part of the vessel during forced circulation. The impregnation fluid was in this case carried exclusively in the same direction of flow as the chips.
[0007] A system is shown in U.S. Pat. No. 5,635,025 in which the chips are fed without prior steaming to a vessel in the form of a combined chip bin, impregnation vessel and chip chute. Steaming of the chips takes place here, the chips lying above the fluid level, and a simple addition of impregnation fluid takes place in the lower part of the vessel.
[0008] A further such system is revealed in U.S. Pat. No. 6,280,567, in which the chips are fed without prior steaming to an atmospheric impregnation vessel in which the chips are heated by the addition of warm black liquor that maintains a temperature around 130-140° C. The black liquor at high temperature is added is just below the fluid level and is subjected to a reduction of pressure up through the bed of chips, after which foul-smelling released gases are removed from the top of the vessel. This creates large volumes of foul-smelling gases, which must be handled and destroyed in special systems. In this case, the impregnation fluid passes strictly in a concurrent flow direction, that is, impregnation fluid and chips move in a downwards direction. An alternative system is revealed by SE,A,9802879-8, in which pressurised black liquor is added to the upper part of the steaming vessel, whereby the black liquor after being subjected to a pressure reduction releases steam for the steaming process. In this case, excess fluid, black liquor, can be drawn off from the lower part of the vessel.
[0009] The prior art has mostly exploited steaming as a major part of the heating of the chips, in which the steam that is used is either constituted by fresh steam or by steam flashed off from pressurised black liquor obtained from the cooking process. This involves a relatively large flow of steam, and its associated consumption of energy, and it requires a steaming system that can be regulated.
[0010] The steaming has also involved the generation of large amounts of foul-smelling gases, and, at certain concentrations, a serious risk of explosion. Problems arise when handling these volatile and readily condensed gases, which, for example, are constituted by turpentine and other hydrocarbons. Special systems for handling these waste gases are required, and these must be dimensioned to cope with the volumes generated. Expensive systems with high capacity are required when these waste gases are created in large volumes.
THE OBJECT AND PURPOSE OF THE INVENTION
[0011] The principle object of the invention is to obtain an improved arrangement for the impregnation and heating of unsteamed chips, which arrangement does not demonstrate the disadvantages that are associated with other known solutions as described above.
[0012] A second object is to enable that the major part of the heating of the chips is made with impregnation fluid, a process that hereafter will be referred to as “fluid steaming” in which it is possible to obtain a natural reduction in temperature of the impregnation fluid by the establishment of an upper counterflow zone since the cold chips are progressively warmed by direct heat exchange during their downwards sinking motion in the vessel. In this way, it is possible in one preferred embodiment to balance the counterflow in this upper zone such that a suitable temperature is obtained in the upper part of the fluid zone, this temperature preferably being sufficiently low to prevent an extensive flashing of steam upwards through the bed of chips. This reduces the amount of foul-smelling gases released, these being to a large extent bound to the withdrawn impregnation fluid. A direct heat exchange with the cold sinking chips is obtained in the counterflow that is being considered, which is the reason that the impregnation fluid that is withdrawn can be maintained at such a low temperature that the volatile gases that are otherwise expelled can be retained in solution in the colder impregnation fluid, and finally withdrawn to a major degree together with the impregnation fluid.
[0013] A further object is to make it possible to control the heating process more accurately by the use of impregnation fluids with increasing temperatures at different positions down through the impregnation vessel, whereby the risk of steam blowing through the bed of chips is eliminated, while it is at the same time possible to obtain a high final temperature of the chips when in slurry form. This fluid steaming, which is thus established over a large section of the impregnation vessel, has surprisingly proved to expel the major part of the air and inert gases that are bound in the chips.
[0014] In particular, when cooking eucalyptus and other easily cooked wood raw lo materials, and in cases when the chips maintain a temperature that is in excess of normal ambient temperature, i.e. over 20° C., the steaming operation using externally applied steam can be completely omitted.
[0015] In certain operational situations, such as the use of cold chips during the winter, light steaming may be necessary in order to raise the temperature of the chips to the normal value of 20-30° C., but with a severely reduced requirement for steaming compared with that needed by previously known technology.
[0016] A requirement for a certain degree of steaming may arise when using material that requires more cooking, such as softwood, with a high content of turpentine, etc., but this is severely reduced compared with that needed by previously known technology, and thus represents a major reduction in the volume of waste gases generated.
[0017] It was also an advantage if a withdrawal strainer was used, with which an efficient separation of not only foul-smelling gases but also impregnation fluid could be achieved. Much of the foul-smelling gases are bound to the withdrawn impregnation fluid when using the wet-steaming technology that is under consideration.
[0018] The invention can advantageously be used when cooking eucalyptus, bagasse and other annual plants, and it can also be used in association with the cooking of coniferous and deciduous pulp.
DESCRIPTION OF DRAWINGS
[0019] FIG. 1 shows an impregnation vessel according to the invention;
[0020] FIG. 2 shows schematically the temperature profile in the impregnation vessel;
[0021] FIG. 3 shows a used withdrawal strainer;
[0022] FIG. 4 shows the establishment of a counterflow in the upper zone.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0023] An arrangement for the impregnation of chips during the manufacture of chemical pulp is shown in FIG. 1 . The arrangement comprises an essentially cylindrical impregnation vessel 30 arranged vertically into which unsteamed chips are continuously fed into the top of the impregnation vessel via feed means, in the form of a small chip bin 1 without steaming and a chute feed (chip feed) 2 . The chips that are fed into the impregnation vessel are thus unheated chips that normally have the same temperature as the ambient temperature ±5° C.
[0024] The pressure in the vessel can be adjusted as necessary through a control valve 31 arranged in a valve line 4 at the top of the impregnation vessel, possibly also in combination with control of the steam ST via input lines 5 . When atmospheric pressure is to be established, this valve line can open out directly to the atmosphere. It is preferable that a pressure is established at the level of atmospheric pressure, or a slight deficit pressure by the outlet 4 of magnitude −0.5 bar (−50 kPa), or a slight excess pressure of magnitude up to 0.5 bar (50 kPa).
[0025] Input of a ventilating flow, SW_AIR (sweep air), can be applied at the top as necessary, which ensures the removal of any gases present.
[0026] The impregnated chips are continuously output via output means, here in the form of an outlet 10 , possibly also in combination with bottom scrapers (not shown in the drawing), at the bottom of the impregnation vessel 30 .
[0027] According to the invention, a first input line 7 a with impregnation fluid BL 1 is connected to the impregnation vessel at a first height P 1 on the impregnation vessel corresponding to distance HI below the strainer 6 , which height is arranged under a maximum level LIQ_LEV of the chips in the impregnation vessel. The temperature of the impregnation fluid BL 1 is adjusted by temperature-regulation means 32 to a first temperature before its addition at this first height, in this case a shunt circuit with cooled and with uncooled impregnation fluid.
[0028] Furthermore, at least one other input line 7 b with impregnation fluid is connected to the impregnation vessel at a second height, P 2 , corresponding to distance H 1 +H 2 below the strainer 6 , which second height is arranged under the first height P 1 on the impregnation vessel. The temperature of the impregnation fluid is adjusted by temperature-regulation means 32 to a second temperature before its addition at this second height. This second temperature exceeds the first temperature by at least 5° C.
[0029] A withdrawal strainer 6 is arranged in the wall of the impregnation vessel 30 at a height above the first height, whereby a maximum liquid level LIQ_LEV can be established in the impregnation vessel under the highest level CH_LEV of the chips in the impregnation vessel. Control of the level occurs by adjusting the balance between the addition of impregnation fluid BL 1 , BL 2 , (BL 3 ) through the input lines 7 a , 7 b, ( 7 c ) and the current withdrawal REC through the withdrawal strainer 6 and output from the bottom 10 . The liquid level must thus be established such that it lies under the highest level CH_LEV of the chips in the impregnation vessel.
[0030] The level CH_LEV of the chips above the level LIQ_LEV of the liquid must be at least 2 metres and preferably at least 5 metres when impregnating eucalyptus. In the case of wood raw material of lower density, for example, softwood, which has a density that is up to 30% lower, a corresponding increase in the height of the column of chips over the surface of the fluid is established. This height is important in order to provide an optimal passage of the chips in a column.
[0031] Since the outlet 6 for impregnation fluid is located at a position in the impregnation vessel that lies above the position for addition of the first impregnation fluid BL 1 , a flow in the opposite direction to the sinking motion of the chips is established, indicated by lightly drawn upwards-pointing arrows in FIG. 1 , in at least the upper part of the fluid-filled zone Z 1 in the impregnation vessel 30 .
[0032] It is appropriate that the temperature of the first impregnation fluid BL 1 , the first temperature, lies within the interval 105±5° C., and it is appropriate that addition of the first impregnation fluid takes place through a first input line 7 a under a liquid level LIQ_LEV that has been established by added impregnation fluid in the impregnation vessel 30 at a position in the impregnation vessel at which the ambient pressure corresponds to or exceeds the saturation pressure, which corresponds at a temperature of 105° C. to a level at least 2 metres under the established liquid level LIQ_LEV if the impregnation vessel is not subject to an externally applied pressure.
[0033] The temperature of the second impregnation fluid BL 2 , the second temperature, lies within the interval 120±10° C. and addition of the second impregnation fluid through the second input line 7 b occurs under the position of addition in the impregnation vessel of the first input line, and at a position in the impregnation vessel at which the ambient pressure corresponds to or exceeds the saturation pressure, which corresponds at a temperature of 125° C. to a level at least 13 metres under the established liquid level LIQ_LEV if the impregnation vessel is not subject to an externally applied pressure.
[0034] It is advantageous if at least one third input line 7 c with impregnation fluid is connected to the impregnation vessel at a third height, P 3 , corresponding to distance H 1 +H 2 +H 3 under the strainer 6 , which third height is arranged under the second height P 2 on the impregnation vessel. The temperature of the impregnation fluid is adjusted by temperature-regulation means 32 to a third temperature before its addition at this third height. This third temperature exceeds the second temperature by at least 5° C.
[0035] The temperature of the third impregnation fluid BL 3 , the third temperature, lies within the interval 130±15° C. Addition of the third impregnation fluid occurs through the third input line 7 c under the position of addition in the impregnation vessel of the second input line, and at a position in the impregnation vessel at which the ambient pressure corresponds to or exceeds the saturation pressure, which corresponds at a temperature of 130° C. to a level at least 17 metres under the established liquid level LIQ_LEV if the impregnation vessel is not subject to an externally applied pressure.
[0036] It is preferable that the added impregnation fluid is obtained from a common flow of withdrawn black liquor BL, preferably a withdrawal of black liquor directly from a subsequent digester or via a pressurised impregnation stage. It is appropriate if this withdrawn black liquor BL is constituted by a non-pressurised withdrawal flow direct from the digester, or from a pressurised impregnation stage.
[0037] FIG. 1 shows that the first, second and third impregnation fluids, BL 1 , BL 2 and BL 3 , are to a major degree established from a common flow BL of black liquor that has been withdrawn from a subsequent cooking stage. It is appropriate if this flow is constituted by more than 50%, preferably more than 75%, of black liquor from the digester.
[0038] Temperature control of the different temperature levels is obtained by the use of a shunt circuit 32 . This controls the common original flow BL in such a manner that the first impregnation fluid BL 1 is set to the first temperature by cooling means 20 . The cooling means may be an indirect heat exchanger, a pressure drop cyclone or another form of evaporative cooling, or the addition of cold fluid, preferably colder process fluids, basic or washing filtrate.
[0039] The third impregnation fluid BL 3 can be obtained directly from the common flow BL of black liquor at the existing temperature of the black liquor. If this temperature is initially too high, cooling of the common flow BL can, naturally, take place first.
[0040] The temperature of the second impregnation fluid BL 2 is set by the mixing by means of mixing means, suitably by simple flow regulation in the shunt circuit 32 in a known manner, of the cooled flow BL 1 and the non-cooled sub-flow BL 3 of black liquor.
[0041] Even though steaming is not required for readily cooked pulps such as eucalyptus and annual plants, at a normal outdoor around 20° C., addition of extra steam ST can take place through addition means 5 arranged in the wall of the impregnation vessel, or through central pipes, above the fluid level LIQ_LEV established by the impregnation fluid.
[0042] Through the arrangement according to the invention using fluid steaming, it is possible to apply a method for the impregnation of chips during the manufacture of chemical pulp in which the chips, without preceding steaming with steam, are continuously fed into the top of an impregnation vessel, in which a pressure, at essentially the same pressure as atmospheric pressure, ±0.5 bar, is established at the top, and from which impregnated chips are continuously fed out from the bottom of the vessel. The chips are subsequently warmed in an upper fluid-filled zone Z 1 of the impregnation vessel by the addition of a first impregnation fluid BL 1 at a first temperature. The chips are subsequently warmed in a second fluid-filled zone Z 2 , under the upper zone, by the addition of at least one second impregnation fluid BL 2 at a second temperature that exceeds the first temperature by at least 5° C. A flow of impregnation fluid in the direction opposite to the sinking motion of the chips is established in at least the upper zone Z 1 of the impregnation vessel by the establishment in the impregnation vessel of a fluid level LIQ_LEV through the addition and withdrawal of impregnation fluid, where the fluid level lies below the maximum level CH_LEV reached by the chips in the impregnation vessel, and by the withdrawal REC of impregnation fluid taking place at a position in the impregnation vessel above the location of addition of the first impregnation fluid.
[0043] A better and more accurately controlled heating of the chips can be achieved with this method, during simultaneous impregnation with successively warmer impregnation fluids.
[0044] The first temperature of BL 1 is adjusted such that the temperature appropriately exceeds 100° C., preferably within the interval 100-110° C., and addition of the first impregnation fluid takes place under a fluid level in the impregnation vessel that has been established by the added impregnation fluid at a position in the impregnation vessel at which the ambient pressure corresponds to or exceeds the saturation pressure.
[0045] The second temperature of BL 2 exceeds 110° C., preferably within the interval 110-130° C., and addition of the second impregnation fluid takes place under the position of addition of the first impregnation fluid in the impregnation vessel, and at a position in the impregnation vessel at which the ambient pressure corresponds to or exceeds the saturation pressure.
[0046] In one preferred embodiment, shown in the drawing, the chips are heated in a third fluid-filled zone Z 3 under the second zone by the addition of a third impregnation fluid BL 3 at a third temperature that exceeds the second temperature by at least 5° C. The third temperature is adjusted to exceed 115° C., preferably within the interval 115-145° C., and addition of the third impregnation fluid takes place under the position of addition of the second impregnation fluid in the impregnation vessel, and at a position in the impregnation vessel at which the ambient pressure corresponds to or exceeds the saturation pressure.
[0047] An impregnation vessel that is at least 25 metres high, preferably 30-50 metres high, is used in one implementation of the method.
[0048] The upper part of the impregnation vessel above the strainer 6 , the height of the chips H 0 together with the empty volume above, can correspond to at least 6 metres (3+3 metres), and a more advantageous approximately 8 metres (5 metres chip height+3 metres empty volume, buffer volume).
[0049] Impregnation fluids with progressively increasing temperatures are added according to the invention at increasing distances below the strainer 6 and below the established fluid level LIQ_LEV.
[0050] With atmospheric pressure, approximately 100 kPa (1 bar), at the top of the impregnation vessel, the first impregnation fluid having the lowest temperature, a temperature, however, that must exceed 100 degrees, is added at a position at which the hydrostatic pressure from the column of fluid that lies above it corresponds to or exceeds the saturation pressure.
[0051] At a temperature of BL 1 of 105° C., this corresponds to a saturation pressure of 120.8 kPa, that is, a fluid column of just over 2 metres height. Thus the line 7 a must open at a location more than 2 metres below the fluid level LIQ_LEV that has been established.
[0052] At a temperature of BL 2 of 125° C., this corresponds to a saturation pressure of 232.1 kPa, that is, a fluid column of just over 13 metres height. Thus the line 7 b must open at a location more than 13 metres below the fluid level LIQ_LEV that has been established.
[0053] At a temperature of BL 3 of 130° C., this corresponds to a saturation pressure of 270.1 kPa, that is, a fluid column of approximately 17 metres height. Thus the line 7 c must open at a location more than 17 metres below the fluid level LIQ_LEV that has been established.
[0054] Naturally, more or fewer additions of impregnation fluids can take place through the impregnation vessel. However, according to the invention, these must always be added such that pressure reduction does not take place, with its associated risk of steam blowing through up through the column of chips, which can disturb the passage of chips and generate foul-smelling gases that are expelled from the chips and are not bound in the withdrawn impregnation fluid REC.
[0055] The following table gives suitable positions for the addition of different impregnation fluids at different temperatures, at atmospheric pressure or at a pressures of ±0.5 bar at the top of the impregnation vessel.
Temperature Height under Height under Height under of Saturation fluid level, with fluid level, fluid level, impregnation pressure atm pressure with +50 kPa with −50 kPa fluid kPa at top at top at top 105° C. 120.8 >2 metre — >7 metre 110° C. 143.3 >4.3 metre — >9.3 metre 115° C. 169.1 >6.9 metre >1.9 metre >11.9 metre 120° C. 198.5 >9.8 metre >4.8 metre >14.8 metre 125° C. 232.1 >13.2 metre >8.2 metre >18.2 metre 130° C. 270.1 >17.0 metre >12 metre >23 metre 135° C. 313.0 >23.3 metre >18.3 metre >28.3 metre 140° C. 361.3 >26.1 metre >21.1 metre >31.1 metre 145° C. 415.4 >31.5 metre >26.5 metre
[0056] The first, second and third impregnation fluids, BL 1 , Bl 2 and BL 3 are in the method according to the invention principally established from one common flow of black liquor that has been withdrawn from a subsequent cooking stage. It is appropriate that the black liquor, which already has a high temperature when withdrawn form the digester, constitutes more than 50% and preferably more than 75% of the impregnation fluid. Energy can be managed in this way in an efficient manner.
[0057] The relevant subflows BL 1 , BL 2 and BL 3 with different temperatures are obtained in that the common flow BL is divided into at least two flows: one cooled flow and one non-cooled flow. The temperature of the first impregnation fluid BL 1 is adjusted by cooling the black liquor BL. The third impregnation fluid BL 3 is obtained directly from the common flow of black liquor. The temperature of the second impregnation fluid BL 2 is adjusted by mixing the cooled flow and the non-cooled flow of black liquor.
[0058] When impregnation primarily easily cooked types of wood, such as eucalyptus and other annual plants, steaming can be essentially avoided. Steam is thus not added to the chips that lie on top of the fluid level established by the impregnation fluid during normal steady-sate operation. The invention can also be applied even if coniferous and deciduous wood (softwood and hardwood) are used as raw material, giving a markedly reduced need for steaming, that is, a reduced addition of steam.
[0059] When treating primarily wood raw material that is difficult to cook, coniferous and deciduous wood, and in operational cases with extremely low temperature of the chips, (such as during the winter), the chips that lie above the fluid level established by the impregnation fluid can be heated by the addition to the impregnation vessel of external steam such that a temperature of the chips of at least 20° C. and of 80° C. at the most is obtained on the chips before the chips reach the fluid level that has been established by the impregnation fluid.
[0060] FIG. 2 shows schematically the temperature profile in the impregnation vessel during the use of an arrangement equivalent to that shown in FIG. 1 , when operating conditions are advantageous. The reduced energy supply that is required to raise the temperature by steaming from a low chip temperature to the standard value of 30° C. is shown in the drawing as the diagonally shaded area.
[0061] This case is based on chips with a moisture content around 35%, a temperature of approximately 30° C. and a production amount of 1500 ADMT/day. In this case, an input of 0.68 tonne/tonne of wood moisture is obtained, that is, 0.68 tonnes of wood moisture per tonne of chips accompanies the chips.
[0062] The arrangement can be adjusted such that the temperature of the impregnation fluid REC that is withdrawn lies around 30° C. The following standard amounts and temperatures apply in these operational conditions:
BL 1 : 105° C., and a flow of 2.85 tonne/hour BL 2 : 125° C., and a flow of 1.5 tonne/hour BL 3 : 132° C., and a flow of 1.5 tonne/hour REC: 30° C., and a flow of 0.96 tonne/tonne (i.e. 0.96 tonne fluid per tonne of chips).
[0067] A temperature of the mixture of approximately 117° C. is obtained under these conditions, which, together with the exothermic reaction with the black liquor, which corresponds to a temperature rise of approximately 5° C., ensures a final temperature of approximately 122° C. of the chips when fed out from the impregnation vessel.
[0068] At this level of the flow in the counterflow zone Z 1 , which preferably lies within the interval 50-150% of the flow of chips, calculated as a weight percentage, i.e. that 0.50-1.50 tonnes of fluid per tonne of chips is withdrawn at the flow REC, a first heating of the chips is obtained in direct heat exchange between the chips and the counterflow of impregnation fluid, which means that the temperature of the impregnation fluid is gradually reduced up through the zone Z 1 from its value of 105° C. down to 30° C. By adjusting the withdrawal flow, or by adjusting the cooling (in the heat exchanger 20 ), the withdrawal temperature can be maintained essentially constant at such a low value that the impregnation fluid does not cause evaporation of the volatile components of the chips, and/or the black liquor, and instead binds these in the impregnation fluid, with these components being successively withdrawn through the withdrawal flow REC.
[0069] FIG. 3 shows an advantageous design of the withdrawal strainer 6 , which can be used in association with the fluid steaming system according to the invention. The withdrawal strainer 6 withdraws impregnation fluid from a fluid steaming arrangement according to FIG. 1 , but is here arranged in the wall of the vessel directly prior to an increase in diameter of the vessel in a conventional manner. The unsteamed chips lie above the fluid level LIQ_LEV in the form of columns of chips with a predetermined height. The fluid level LIQ_LEV is established with the aid of a level sensor 63 that controls the evacuation pump 62 in the lower outlet. The region behind the withdrawal strainer 6 external to the column of chips is divided into an upper and a lower region, whereby a first evacuation channel is connected, via a pump or ejector 61 , to the upper part of the region, and a second evacuation channel is connected, via a pump 62 , to the lower part of the region, for evacuation of volatile gases (and/or foam 65 ) and impregnation fluid in the different evacuation channels. An unlinking plate 64 can be mounted in order to prevent that part of the column of chips that has not yet reached the fluid level from being subjected to too great a deficit of pressure. It is also possible for the pump 62 to drive an ejector 61 such that the fluid that is withdrawn via the pump 62 carries foam and gases with it.
[0070] FIG. 4 shows how a counterflow of impregnation fluid can be established by the addition of the first impregnation fluid BL 1 . If a lower temperature of around 100° C. is used for the first impregnation fluid BL 1 , the addition can take place directly under the established fluid level LIQ_LEV, with the subsequent withdrawal radially external to the level of addition P 1 . In this case it is important to establish at least one radial flow BL 1 , with a vertical component of flow BL 1 V and a horizontal component of flow BL 1 H . It is preferable that the ratio of BL 1 V to BL 1 H is maintained above a minimum value 1:10 if the temperature lies around 100° C. and under atmospheric conditions in an impregnation vessel with a diameter of 6 metres. At an increased temperature around 105° C. and under atmospheric conditions in an impregnation vessel of diameter 6 metres, the ratio of BL 1 V :BL 1 H can correspond to 2:3.
[0071] The invention can be modified in a number of ways within the framework of the attached claims. Considerably more than 2-3 impregnation fluids of different temperatures can be added at different heights in the impregnation vessel, either through central pipes (that open out in the centre of the column of chips) or through inlet nozzles in the wall of the vessel. In the same manner, several locations of addition (different heights) of impregnation fluid at the same temperature can be used, in particular in the lower part of the impregnation vessel.
[0072] Withdrawal strainers in addition to that shown in FIG. 1 , strainer 6 , can be used in the lower part of the impregnation vessel. This is particularly true if very high fluid/woods ratios are established in the impregnation vessel, and if the fluid/wood ratio is to be reduced in the outlet or if another fluid is to replace the impregnation fluid in association with the output.
[0073] The impregnation fluids BL 1 , BL 2 and BL 3 can also be established from totally separate sources, that is, not from one common flow BL of black liquor. For example, BL 1 may be a wash filtrate, obtained, for example, from the washing zone of the digester, while BL 2 /BL 3 may be impregnation fluid obtained from the cooking circuits of the digester.
[0074] The impregnation fluids can also be provided with a basic supplement with the object of establishing alkali profiles that are necessary for the process, in particular if the residual alkali in the black liquor is low. A rapid initial consumption of alkali normally takes place, while it is desired to keep the final withdrawal REC low. This is the reason that progressively increasing supplements of alkali can be added to the impregnation fluids as the chips successively sink downwards through the impregnation vessel.
[0075] It is appropriate if the flow REC withdrawn from the impregnation vessel is carried directly to evaporation/recycling.
[0076] It is also possible that more than one counterflow zone can be established in the upper fluid-filled part of the impregnation vessel.
[0077] An additional supplement of colder impregnation fluid, in the region 60-90° C., may also be added at the top of the fluid-filled counterflow zone. This fluid at a lower temperature can be added continuously or it can be added as required. | The method and an arrangement are for improved impregnation of chips in association with the manufacture of chemical cellulose pulp. Un-steamed chips are fed into an impregnation vessel ( 30 ) in which a fluid level (LIQ_LEV) is established under the highest level (CH_LEV) of the chips. An improved impregnation arrangement for the chips is obtained by the addition of impregnation fluids (BL 1 /BL 2 /BL 3 ) with increasing temperatures at different heights (P 1, P 2, P 3 ), and by the establishment of a counter-flow zone (Z 1 ) in the uppermost part of the impregnation vessel. The requirement for steaming may in this way be dramatically reduced while at the same time the amount of expelled waste gases may be minimized. A major part of the volatile compounds present in the wood are bound to the impregnation fluid (REC) that is withdrawn. | 3 |
BACKGROUND OF THE INVENTION
The present invention relates generally to an optical head applicable to different types of magneto-optical disks, and a magneto-optical disk storage having such an optical head.
The conventional magneto-optical disk storage has an optical head corresponding to each type of magneto-optical disk. That is, different optical heads are used for respective p-polarized and s-polarized light types of magneto-optical disks. If the optical head does not correspond to the type of the magneto-optical disk, a desired reproducing operation cannot be performed due to the low output level of a tracking error signal. Hereupon, a laser beam of the optical head corresponding to the p-polarized light type of magneto-optical disk transmits parallel to the grooves thereon. On the other hand, a laser beam of the optical head corresponding to the s-polarized light type of magneto-optical disk transmits vertical to the grooves thereon.
However, it is troublesome to prepare a different optical head for each type of magneto-optical disk.
SUMMARY OF THE INVENTION
Accordingly, it is a general object of the present invention to provide a novel and useful optical head and a magneto-optical disk storage having such an optical head in which the above disadvantage is eliminated.
Another object of the present invention is to provide an optical head and a magneto-optical disk storage having such an optical head which are applicable to different types of magneto-optical disks.
According to one feature of the present invention, an optical head comprises laser means for radiating a laser beam, including polarizing means polarizing the laser beam, said laser means irradiating the laser beam with a predetermined angle of a polarized light surface on a desired groove on a magneto-optical disk with a plurality of grooves thereon, first detecting means for detecting a Kerr rotating angle of the laser beam at the desired groove, reproducing means for reproducing information recorded on the magneto-optical disk based on the Kerr rotating angle detected by the first detecting means, second detecting means for detecting a reflecting beam of the laser beam as a tracking error signal at the magneto-optical disk in order to transmit the laser beam on the desired groove, and angle changing means, coupled to the second detecting means, for changing the angle of the polarized light surface of the laser beam by controlling said polarizing means so that the strength of the tracking error signal detected by the second detecting means can be maximized.
According to another feature of the present invention, a magneto-optical disk storage comprises an optical head which comprises laser means for radiating a laser beam, including polarizing means polarizing the laser beam, said laser means irradiating the laser beam with a predetermined angle of a polarized light surface on a desired groove on a magneto-optical disk with a plurality of grooves thereon, first detecting means for detecting a Kerr rotating angle of the laser beam at the desired groove, reproducing means for reproducing information recorded on the magneto-optical disk based on the Kerr rotating angle detected by the first detecting means, second detecting means for detecting a reflecting beam of the laser beam as a tracking error signal at the magneto-optical disk in order to transmit the laser beam on the desired groove, and angle changing means, coupled to the second detecting means, for changing the angle of the polarized light surface of the laser beam by controlling said polarizing means so that the strength of the tracking error signal detected by the second detecting means can be maximized, driving means for driving the optical head, and control means for controlling the operating of the optical head.
According to the present invention, since the angle changing means changes the angle of the polarized light surface of the laser beam, the optical head can be applied to both p-polarized light type and s-polarized light type of magneto-optical disk storages.
Other objects and further features of the present invention will become apparent from the following detailed description when read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A shows a plane view of an magneto-optical disk storage of a first embodiment according to the present invention;
FIG. 1B is a view showing an optical path 43 shown in FIG. 1A:
FIG. 2A shows a waveform view of a tracking error signal generated in a case where an optical head corresponding to a magneto-optical disk reproduces information thereon;
FIG. 2B shows a waveform view of a tracking error signal generated in a case where an optical head which does not correspond to a magneto-optical disk reproduces the information thereon;
FIG. 3 shows a 1/2 wavelength plate located at a first rotating position Q 1 ;
FIG. 4 shows a 1/2 wavelength plate located at a second rotating position Q 2 ;
FIG. 5 shows a plane view of a magneto-optical disk storage of a second embodiment according to the present invention;
FIG. 6A shows a waveform view representing different output levels of a tracking error signal obtained from a p-polarized light type magneto-optical disk in cases where the 1/2 wave length plate is located at the first rotating position Q 1 and the second rotating position Q 2 ;
FIG. 6B shows a waveform view representing different output levels of a tracking error signal obtained from a s-polarized light type magneto-optical disk in cases where the 1/2 wave length plate is located at the first rotating position Q 1 and the second rotating position Q 2 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The magneto-optical disk storage 10 of the first embodiment according to the present invention comprises, as shown in FIGS. 1A and 1B, an objective lens 4, a semiconductor laser 5, a beam formation prism 6, a beam splitter 7, a light detector for detecting a tracking signal 8, a collimator lens 11, a reflecting prism 13, a convex lens 15, a polarized beam splitter 16, a differential amplifier 18, a driving circuit 20, a cylindrical lens 21, a light detector for detecting a focus error signal 22, a monitoring detector 23, a permanent magnet 24, a 1/2 wavelength plate 41, a cylindrical gear 42, a stepping motor 44, a gear 45, a comparator 50, a reference level signal generating circuit 51 and a motor driving circuit 52.
The semiconductor laser 5, collimator lens 11, beam formation prism 6, beam splitter 7, 1/2 wavelength plate 41, reflecting prism 13 and objective lens 4 are aligned on an optical path 43. On the other hand, the convex lens 15 and the polarized beam splitter 16 are aligned on the optical path generated by the beam splitter 7, the cylindrical lens 21 and the light detectors 8 and 22 are aligned on the optical path generated by the beam splitter 16. The beam formation prism 6 is engaged with the beam splitter 7. The 1/2 wave length plate 41 is fixed inside the cylindrical gear 42. The gear 45 is engaged with the stepping motor 44 and the cylindrical gear 42. The light detector 8 is connected to input terminals of the differential amplifier 18. The minus terminal of the comparator 50 is connected to the output of the differential amplifier 18, and the plus terminal thereof is connected to the output terminal of the reference level signal generating circuit 51. The output of the comparator 50 is inputted to the driving circuit 52. The output terminal of the differential amplifier 18 is connected to the input terminal of the driving circuit 20. The driving circuit 20 is connected to the objective lens 4.
The objective lens 4 is opposite to the lower surface of the magneto-optical disk 2. The magneto-optical disk 2 has a plurality of grooves in a circumferential direction thereof, and is rotated at a high speed. The magneto-optical disk 2 used for the embodiments of this invention is of a p-polarized light type or s-polarized light type. The ellipse-shaped laser beam 10 outputted from the semiconductor laser 5 has a p-polarized light surface in a minor axis and a s-polarized light surface in an apse axis. The beam formation prism 6 forms the laser beam 10. After the laser beam 10 penetrates through the beam splitter 7, it becomes a laser beam 12. The monitoring detector 23 monitors the output of the laser beam 10 of the semiconductor laser 5. In this embodiment, a vibration direction of the p-polarized light of the laser beam 12 initially coincides with the direction of the grooves 3 (circumferential direction) of the magneto-optical disk 2.
The light detector 8 comprises a photo diode and detects the tracking error signal. Incidentally, the tracking error signal has the known reference level. If the optical head which does not correspond to the type of the magneto-optical disk 2 detects the tracking signal by means of the push-pull method, the output level of the tracking error signal becomes approximately one-third as large as that detected by the optical head which corresponds to the type of the magneto-optical disk. That is, the output level of the tracking error signal detected by the optical head which corresponds to the type of the magneto-optical disk is indicated as shown in FIG. 2A, and the output level of the tracking error signal detected by the optical head which does not correspond to the type of the magneto-optical disk is indicated as shown in FIG. 2B. The light detector 22 detects the focus error signal. Because of the light detectors 8 and 22, information recorded on the magneto-optical disk can be reproduced. The driving circuit 20 corrects the tracking error based on the output from the differential amplifier 18 by driving the objective lens 4 in the direction vertical to the grooves 3.
The 1/2 wavelength plate 41 rotates the polarized light surface of the incident light by 45 . The 1/2 wavelength plate 41 is located so that the signal detection sensitivity can be maximized, and in addition, the penetrating light and reflecting light through the beam splitter 16 can be made equal to each other to remove noises generated by the changing of the reflection ratio of the disk 2. The 1/2 wavelength plate 41 can be provided pivotally in the directions B 1 and B 2 between a first rotating position Q 1 and a second rotating position Q 2 . When the 1/2 wavelength plate 41 is located at the first rotating position Q 1 , its optical axis 46 coincides with the X-axis, and when it is located at the second rotating position Q 2 , its optical axis 46 is inclined toward the X-axis by 45°. The direction of the X-axis coincides with the vibration direction of the laser beam 12. The 1/2 wavelength plate 41 is initially located at the first rotating position Q 1 , and thus the laser beam 12 penetrates through the 1/2 wavelength plate 41 without an angle of its polarized light surface being rotated. On the other hand, if the 1/2 wavelength plate 41 is located at the second rotating position Q 2 , the angle of the polarized light surface of the laser beam 12 is rotated by 90° after the laser beam 12 is penetrated therethrough.
The comparator 50 compares the output level of the tracking error signal transmitted from the differential amplifier 18 with the reference output level Vref of a signal transmitted from a reference level signal generating circuit 51, and consequently outputs the comparing result signal b to the motor driving circuit 52. Incidentally, the relationships between the output levels V 1 and Vref and the output levels V 2 and Vref are indicated in FIGS. 2A and 2B. The comparing result signal b becomes a low level when the output level of the tracking error signal is higher than the reference output level Vref, and becomes a high level when the output level of the tracking error signal is lower than the reference output level Vref. The motor driving circuit 52 does not operate when the comparing result signal b is a low level, but operates when the comparing result signal be is a high level and outputs a pulse string signal, by which the 1/2 wavelength plate 41 is rotated by 45°, to the stepping motor 44.
Next, a description will now be given of the operation of the magneto-optical disk storage 10. First, a magneto-optical disk 2 is experimentally reproduced. The laser beam 10 output from the semiconductor laser 5 is transmitted into the beam formation prism 6 via a collimator lens 11 so as to have a circular section, and output from the beam splitter 7 as a laser beam 12 to the objective lens 4. The laser beam 12 is reflected by the reflecting prism 13 and focused on the magneto-optical disk 2 by the objective lens 4. The polarized light surface of the laser beam 12 is rotated 14 by a magnetic Kerr effect, so that the laser beam 12 becomes a reflected laser beam 14. The laser beam 14 comprises a magneto-optical signal and a servosignal including a focus error signal and a tracking error signal. The laser beam 14 is reflected by the reflecting prism 13 via the objective lens 4 and directed to the beam splitter 7. The laser beam 14 is partially reflected by the beam splitter 7 and divided into two directions by the polarized light beam splitter 16 through the convex lens 15. A part of laser beam 17 through the polarized light beam splitter 16 is transmitted into the light detector 22 via the cylindrical lens 21 and the rest thereof is transmitted into the light detector 8.
The output from the light detector 8 is supplied to the differential amplifier 18 and is supplied as a tracking error signal 19 to the driving circuit 20. If the disk is the p-polarized light type, the output level V 1 of the tracking error signal 19 becomes higher than the reference output level Vref, so that the comparison result signal b becomes a low level and the circuit 52 does not operate. Since the motor 44 is not driven, the 1/2 wavelength plate 41 is kept be located at the first rotating position Q 1 . After the experimental reproducing of the magneto-optical disk 2, information recorded on the magneto-optical disk 2 is reproduced without changing an angle of the polarized light surface of the laser beam 12, as shown in FIG. 3.
However, if the magneto-optical disk 2 is the s-polarized light type, the output level V 2 of the tracking error signal 19 is lower than the reference output level Vref, so that the comparison result signal b becomes a high level and thus the circuit 52 starts to operate. Consequently, the circuit 52 outputs the pulse string signal to the stepping motor 44. Responsive thereto, the stepping motor 44 rotates the 1/2 wavelength plate 41 by 45° in the direction B 2 to the second rotating position Q 2 , via the cylindrical gear 42. As a result, as shown in FIG. 4, the angle of the polarized light surface of the laser beam 12 is rotated by 90° when the laser beam 12 penetrates through the 1/2 wavelength plate 41, and the vibration direction of the p-polarized light coincides with the radial direction of the magneto-optical disk 2. Needless to say, the angle of the polarized light surface of the laser beam 14 is also rotated by 90° when the laser beam 14 penetrates through the 1/2 wavelength plate 41. By rotating the angle of the polarized light surface by 90°, the output level of the tracking error signal changes from V 2 to V 1 After the experimental reproducing of the magneto-optical disk 2, the information recorded on the disk 2 is reproduced.
A description will now be given of the magneto-optical disk storage 60 of the second embodiment according to the present invention with reference to FIG. 5. Incidentally, those elements which are the same as corresponding in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted. In this embodiment, the comparator 50 and the reference level signal generating circuit 51 in FIG. 1A are respectively substituted by the memory 71, control circuit 72 and the comparator 72. The output of the differential amplifier 18 is inputted into the driving circuit 20 and the memory 71. On the other hand, the output of the control circuit 72 is inputted into the memory 71. The output of the memory 71 is inputted into the comparator 73. The output of the comparator 73 is inputted into the motor driving circuit 52. Incidentally, the experimental reproducing signal 70 is inputted into the motor driving circuit 52 when the disk 2 is experimentally reproduced. The motor driving circuit 52 moves the 1/2 wavelength plate 41 from the first rotating position Q 1 to the second rotating position Q 2 a predetermined time later in response to the experimental reproducing signal 70. The memory 71 memorizes the output levels V 10 and V 20 of the tracking error signal while the 1/2 wavelength plate 41 is being located at the first rotating position Q 1 and the output levels V 11 and V 21 of the tracking error signal while the 1/2 wavelength plate 41 is being located at the second rotating position Q 2 . The control circuit 72 controls the operation of the memory 71. The comparator 73 compares the output levels V 10 and V 20 with the output levels V 11 and V 21 .
A description will now be given of the operation of the magneto-optical disk storage 60. First, the disk 2 is experimentally reproduced. If the disk 2 is the p-polarized light type, the tracking error signal having the output level V 10 , as shown in FIG. 6A, is initially obtained. Then, when the experimental reproducing signal 70 is supplied to the motor driving circuit 52 and thus the 1/2 wavelength plate 41 is rotated to the second rotating position Q 2 , the tracking error signal having the output level V 11 is obtained. The memory 71 memorizes the output levels V 10 and V 11 .
On the other hand, if the disk 2 is the s-polarized light type, the tracking signal having the output level V 20 , as shown in FIG. 6B, is initially obtained. Then, when the experimental reproducing signal 70 is supplied to the motor driving circuit 52 and thus the 1/2 wavelength plate 41 is rotated to the second rotating position Q 2 , the tracking error signal having the output level V 21 is obtained. The memory 71 memorizes the output levels V 20 and V 21 .
The controller 72 instructs the memory 71 to output the output levels V 10 and V 11 or the output levels V 20 and V 21 to the comparator 73. Thus, whether the disk 2 is the p-polarized light type or the s-polarized light type can be judged. The angle of the polarized light surface is adjusted by the motor driving circuit 52 so that the tracking error signal having a higher output level can be obtained. After the experimental reproducing of the disk 2, the information recorded on the disk 2 is reproduced.
Incidentally, means for moving/removing the 1/2 wavelength plate 41 located at the second rotating position Q 2 on/from the optical path 43, rather than moving the 1/2 wavelength plate between the first and second rotating positions Q 1 and Q 2 may be used.
Further, the present invention is not limited to these preferred embodiments, but various variations and modifications may be made without departing from the scope of the present invention. | In an optical head in a magneto-optical disk storage, an angle of a polarized light surface of a laser beam can be adjusted so that the strength of a tracking error signal can be maximized. Therefore, the optical head and the magneto-optical disk storage having the optical head is applicable to both p-polarized light type and s-polarized light type magneto-optical disks. Hereupon, the laser beam corresponding to the p-polarized light type magneto-optical disk transmits parallel to the grooves on the magneto-optical disk. On the other hand, the laser beam corresponding to the s-polarized light type magneto-optical disk transmits vertical to the grooves on the magneto-optical disk. Thus, according to the present invention, just one optical head can handle both types of magneto-optical disks. | 6 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] Applicant claims priority under 35 U.S.C. §119 of German Application No. 10 2008 055 909.1 filed Nov. 5, 2008.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to a multi-part piston for an internal combustion engine, having an upper piston part that has a piston crown, and a lower piston part. Each of the piston parts has an inner and an outer support element, which elements delimit an outer circumferential cooling channel and an inner cooling chamber, whose cooling chamber bottom has an opening.
[0004] 2. The Prior Art
[0005] A piston of this type is disclosed in European Patent No. EP 1 222 364 B1. The opening in the cooling chamber bottom allows cooling oil to flow away out of the inner cooling chamber in the direction of the piston crown, in order to achieve a cooling effect as a consequence of the oil passage from the outer circumferential cooling channel to the inner cooling chamber, and to lubricate the piston pin. In order to achieve this goal, the opening in the cooling chamber bottom cannot be too large, because then, the cooling oil would no longer flow away in a metered manner, and its cooling effect in the inner cooling chamber would at least be reduced. This means that the cooling chamber bottom is configured essentially as a relatively wide and thin circumferential ring land that extends approximately in the radial direction, in the upper region of the lower piston part. However, such a structure is difficult to produce. In the case of a forged lower piston part, in particular, there is the additional problem that the microstructure of the material is changed in the region of the ring land, as the result of forging, and this results in an increase in stress in the material structure.
SUMMARY OF THE INVENTION
[0006] It is therefore an object of the invention to provide a piston of the stated type, in such a manner that good cooling of the cooling oil in the interior of the cooling chamber and effective lubrication of the piston pin are guaranteed, and, at the same time, the stability of the lower piston part is not impaired.
[0007] This object is achieved according to the invention with a multi-part piston for an internal combustion engine, having an upper piston part that has a piston crown, and a lower piston part. The upper piston part and the lower piston part each have an inner and an outer support element, which elements delimit an outer circumferential cooling channel and an inner cooling chamber, whose cooling chamber bottom has an opening. A holding element that extends from the underside of the piston crown vertically toward the opening is provided in the inner cooling chamber, which holding element carries a closure element that closes the opening and has at least one cooling oil opening.
[0008] The configuration according to the invention makes it possible to provide a very large opening in the cooling chamber bottom, so that the relatively wide and thin circumferential ring land, which extends approximately in the radial direction, is eliminated. Instead, the opening is closed off with a closure element that is fixed in place by way of a holding element that is connected with the underside of the piston crown. As a result, the stability of the lower piston part is maintained even if it is a forged part. The inner cooling chamber is configured as a circumferential inner cooling channel as the result of the introduction of the holding element, so that the cooling oil is distributed more uniformly and its cooling effect is therefore improved. The at least one cooling oil opening in the closure element provided according to the invention also allows significantly better and more precise metering of the cooling oil that flows away in the direction of the piston pin.
[0009] The closure element preferably has two or more cooling openings, so that a very precisely metered amount of cooling oil can flow away out of the inner cooling chamber, in the direction of the piston crown.
[0010] The opening in the cooling chamber bottom and the closure element are generally configured to be essentially round. If the opening in the cooling chamber bottom is configured to be oval or an oblong hole, it is practical if the closure element has a shape that corresponds to this, in order to completely cover the opening.
[0011] A preferred embodiment provides that the holding element is formed onto the underside of the piston crown, in one piece. As an alternative to this, however, the holding element can also be configured as a separate component and can be held on the underside of the piston crown. The selection is at the discretion of the person skilled in the art, and allows flexible adaptation of the piston properties to the requirements in each operation.
[0012] If the holding element is configured as a separate component, it can be provided with a conical depression, for example. The underside of the piston crown then has a conical elevation that corresponds to this. The holding element is held between the underside of the piston crown and the closure element, with force fit, i.e. in clamped manner, whereby the depression and the elevation engage into one another. This method of construction is particularly easy to implement.
[0013] However, the separate holding element can also have a journal, for example, which is accommodated in a corresponding dead-end hole on the underside of the piston crown. The shape-fit connection of piston crown and holding element brings about a particularly good seat of the holding element, and therefore particularly great stability of the piston according to the invention.
[0014] Independent of how the holding element is attached to the underside of the piston crown, the end of the holding element that faces the opening can have a circumferential contact shoulder that lies on the closure element. The shoulder surrounds a projection that engages into a recess provided in the closure element. Another possibility of attaching the holding element to the closure element consists, for example, in the fact that the end of the holding element that faces the opening has a circumferential groove, into which the closure element engages. Here, too, the shape-fit connection of holding element and closure element offers a particularly reliable, stable hold.
[0015] It is practical if the length of the holding element is dimensioned so that the closure element supports itself on the cooling chamber bottom under resilient bias, and thus no longer has any lateral play. The holding element is thereby fixed in place in a particularly firm manner, above the opening in the cooling chamber bottom.
[0016] In another preferred embodiment of the piston according to the invention, the holding element is configured as a screw or threaded pin, and the underside of the piston crown has a threaded dead-end hole that corresponds to this, in which the holding element is accommodated. The effect of force on the closure element can therefore take place also on its underside. It is practical if the end of the holding element that faces the opening has a circumferential or interrupted flange that engages underneath the closure element.
[0017] Preferably, the opening is provided with a circumferential holding collar that is directed radially inward, and the closure element engages underneath the holding collar with its outer edge. This embodiment has the advantage that it can be assembled even after the upper piston part and lower piston part have been connected.
[0018] The closure element can be made from any desired material. In particular, a spring steel sheet has proven to be well suited. The upper piston part and/or the lower piston part can be cast parts or forged parts, and can be produced, for example, from a steel material, particularly forged steel. Friction welding is a possibility for the joining method.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Other objects and features of the present invention will become apparent from the following detailed description considered in connection with the accompanying drawings. It is to be understood, however, that the drawings are designed as an illustration only and not as a definition of the limits of the invention.
[0020] In the drawings, wherein similar reference characters denote similar elements throughout the several views:
[0021] FIG. 1 shows a section through a first embodiment of a piston according to the invention, whereby the right half of the figure has been rotated by 90° relative to the left half;
[0022] FIG. 2 shows a section through another embodiment of a piston according to the invention, whereby the right half of the figure has been rotated by 90° relative to the left half;
[0023] FIG. 3 shows a section through another embodiment of a piston according to the invention, whereby the right half of the figure has been rotated by 90° relative to the left half; and
[0024] FIG. 4 shows a section through another embodiment of a piston according to the invention, whereby the right half of the figure has been rotated by 90° relative to the left half.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0025] Referring now in detail to the drawings and, in particular, FIG. 1 shows a first embodiment of a piston 10 according to the invention, which is forged from a steel material in this embodiment. Piston 10 according to the invention is composed of an upper piston part 11 and a lower piston part 12 . Upper piston part 11 has a piston crown 13 having a combustion bowl 14 , a circumferential top land 15 , and a circumferential ring belt 16 . Lower piston part 12 has a piston skirt 17 , pin bores 18 for accommodating a piston pin, and pin bosses 19 . Upper piston part 11 and the lower piston part 12 form a circumferential outer cooling channel 21 and a central inner cooling chamber 22 . Cooling chamber bottom 23 of cooling chamber 22 is provided with a relatively large opening 24 .
[0026] Upper piston part 11 has an inner support element 25 and an outer support element 26 . Inner support element 25 is disposed on the underside of upper piston part 11 , circumferentially, in ring shape, and has a joining surface 27 . Inner support element 25 furthermore forms part of the circumferential wall of the inner cooling chamber 22 . Outer support element 26 of the upper piston part 11 is formed below ring belt 16 , and has a joining surface 28 .
[0027] Lower piston part 12 also has an inner support element 31 and an outer support element 32 . Inner support element 31 is disposed on the top of lower piston part 12 , circumferentially, and has a joining surface 33 . Inner support element 31 furthermore forms part of the circumferential wall of inner cooling chamber 22 . Outer support element 32 is formed as an extension of piston skirt 17 in the embodiment shown, and has a joining surface 34 . One or more cooling oil channels 35 are provided in inner support element 31 , and connect cooling channel 21 with cooling chamber 22 . Cooling oil channel 35 runs at an angle upward, proceeding from cooling channel 21 , in the direction of cooling chamber 22 .
[0028] Upper piston part 11 and lower piston part 12 were joined, in the embodiment shown, in known manner, by means of friction welding along joining surfaces 27 , 28 and 33 , 34 , respectively.
[0029] Opening 24 in cooling chamber bottom 23 is closed off with a closure element 36 . In the embodiment shown, closure element 36 is produced from a spring sheet metal, approximately 0.8 mm thick, and has multiple cooling oil openings 37 , which allow the cooling oil to flow away from inner cooling chamber 22 in the direction of the piston crown during operation.
[0030] A holding element 38 , which has approximately the shape of a journal in the embodiment shown, is formed on in one piece on the underside of piston crown 13 , and projects into center axis M of piston 10 , vertically, in the direction of opening 24 . At its free end, holding element 38 has a projection 39 that is surrounded by a circumferential contact shoulder 41 . Projection 39 passes through a central recess 42 provided in closure element 36 , whereby contact shoulder 41 lies on the top of closure element 36 . The length of holding element 38 is dimensioned in such a manner in this embodiment, that closure element 36 supports itself on cooling chamber bottom 23 under spring bias. Closure element 36 is therefore held securely and without play.
[0031] FIG. 2 shows a second embodiment of a piston 110 according to the invention. Piston 110 has essentially the same construction as piston 10 according to FIG. 1 , so that the same structures are provided with the same reference symbols, and with regard to these reference symbols, reference is made to the description of FIG. 1 .
[0032] A significant difference as compared with piston 10 according to FIG. 1 consists in the fact that in piston 110 , the holding element 138 is present as a separate component. In the embodiment shown, holding element 138 is provided with a conical depression 143 at its end that faces piston crown 13 . The underside of piston crown 13 has a corresponding conical elevation 144 . Holding element 138 has a projection 139 at its end that faces closure element 36 , which projection is surrounded by a circumferential contact shoulder 141 . Projection 139 passes through a central recess 42 provided in closure element 36 , whereby contact shoulder 141 lies on the top of closure element 36 . The length of holding element 138 is dimensioned in such a way, in the embodiment shown, that closure element 36 supports itself on cooling chamber bottom 23 under resilient bias, and the conical depression 143 and conical elevation 144 engage into one another. Closure element 36 is therefore held securely and without play.
[0033] FIG. 3 shows a third embodiment of a piston 210 according to the invention. Piston 210 has essentially the same construction as piston 10 according to FIG. 1 , so that the same structures are provided with the same reference symbols, and with regard to these reference symbols, reference is made to the description of FIG. 1 .
[0034] In the case of piston 210 , as well, holding element 238 is configured as a separate component. In contrast to piston 110 according to FIG. 2 , holding element 238 has a journal 245 at its end that faces piston crown 13 . The underside of piston crown 13 is provided with a corresponding dead-end hole 246 , in which journal 245 is accommodated. Holding element 238 has a circumferential groove 247 at its end that faces closure element 36 , in which groove closure element 36 is held by snapping it in. The length of holding element 238 is dimensioned in such a way, in the embodiment shown, that closure element 36 supports itself on cooling chamber bottom 23 under resilient bias. Closure element 36 is therefore held securely and without play.
[0035] Of course, closure element 36 in these embodiments can also consist of a non-resilient, preferably metallic material, and be held on cooling chamber bottom 23 with a clamping action, i.e. with force fit.
[0036] For assembly of these embodiments, holding element 138 , 238 , as applicable, is attached to upper piston part 11 , and then closure element 36 is attached to holding element 38 , 138 , 238 . After upper piston part 11 and lower piston part 12 have been connected, closure element 36 lies firmly on the cooling chamber bottom.
[0037] FIG. 4 shows a fourth embodiment of a piston 310 according to the invention. Piston 310 has essentially the same construction as piston 10 according to FIG. 1 , so that the same structures are provided with the same reference symbols, and with regard to these reference symbols, reference is made to the description of FIG. 1 .
[0038] The significant difference as compared with all the embodiments described until now consists in the fact that in the embodiment of FIG. 4 , holding element 338 is configured as a threaded pin. In place of a threaded pin, of course, a screw can also be used. The underside of piston 13 is provided with a corresponding threaded dead-end hole 348 , into which holding element 338 is screwed. The end of holding element 338 that faces opening 24 has a circumferential or interrupted flange 349 (in the case of a screw: a screw head). Holding element 338 passes through the central bore provided in the closure element, from the underside of closure element 36 that faces the piston pin. Thus, closure element 36 is not on cooling chamber bottom 23 , but rather on the underside of cooling chamber bottom 23 , with force fit, if applicable under resilient bias. For this purpose, the edge of opening 24 is provided, in the embodiment shown, with a circumferential holding collar 351 that is directed radially inward, on which collar closure element 36 lies with its outer edge and engages underneath the holding collar 351 .
[0039] Accordingly, while only a few embodiments of the present invention have been shown and described, it is obvious that many changes and modifications may be made thereunto without departing from the spirit and scope of the invention. | A multi-part piston for an internal combustion engine has an upper piston part with a piston crown, and a lower piston part, each of the piston parts having an inner and an outer support element that delimit an outer circumferential cooling channel and an inner cooling chamber. The cooling chamber bottom has an opening. A holding element is disposed in the inner cooling chamber and extends from the underside of the piston crown vertically toward the opening. The holding element carries a closure element that closes the opening and has at least one cooling oil opening. | 5 |
BACKGROUND OF INVENTION
[0001] Snow shovels, pushers and some combinations have been known for a very long time, some of the following have patents in Canada and United States:
[0000]
CA 2621194 A1
Gerald Westgarde
US 20080185857 A1
Wesley Westgarde, Gerald Westgarde
U.S. Pat. No. 8,444,192
John Pavlic
US 20130233582
Oresti Frati S. R. L.
U.S. Pat. No. 2,728,598 A
Kalman Szllage
U.S. Pat. No. 6,053,548 A
Louis G. Bowles
[0002] This improved design provides 8 selectable steps/options to the user to change the angle of the blade body relative to the ground or surface to be cleaned by just giving a twist of the D shaped hand grip.
SUMMARY OF THE INVENTION
[0003] Considered broadly, snow is removed by pushing it using a snow pusher which accumulates it and then lifted and thrown in a designated area by using snow shovel. The main difference between the two is the angle of the blade body relative to the ground or surface to be cleaned. In a snow shovel, the blade body is nearly horizontal to the ground or surface to be cleaned and in a snow pusher, the blade body is nearly vertical to the surface to be cleaned. If the snow is also required to be pushed towards right or left hand side simultaneously while being pushed forward which helps shifting more volume in the next pushing operation which collects the previously shifted snow along with a fresh layer of snow, then the process requires the blade body to have the ability to also rotate at another axis either to the right or left along with horizontal and vertical angles as required in a shovel and pusher. This angle shifts the pushed snow towards right or left, this shifting of snow is directly proportional to this angle, less shifting with smaller angle and more shifting with greater angle.
[0004] The design of snow shovel and pusher combination with 8 adjustable settings includes a blade body and an elongated handle. Closer to the blade body between the two ends of the long handle is a 360 degree rotating joint which is comprised of two flanges joined together with the help of a steel bolt, nut and two washers while having the ability to rotate with one flange face sliding in a circular motion on the other. This rotating joint comprises of two main parts namely a stationary flange and a rotating flange. The stationary flange has a circular sliding face with 8 concave recesses evenly divided on the sliding face at equal distance from centre. There is also male component attached to the other side of the flange to be inserted in to the blade body attaching receptacle which is part of the blade body. The rotating flange also has a circular sliding face equal to size as in stationary flange. This flange has two tubular housings. Each one to accommodate one spring and one steel ball that are required to achieve the 8 locking positions. There is also a female receptacle attached to the other side of the rotating flange at an angle as a part to be attached to the other end of the. The other end of the long handle has a D shaped hand grip attached to it which is normally found in long handle tools. During use, the blade body in snow pusher setting/mode should be nearly vertical to the surface to be cleaned and in snow shovel setting/mode blade body should be nearly horizontal to the surface to be cleaned. The rotating joint assembly has 8 adjustable setting positions that are lockable.
[0005] The invention with 8 setting options is very useful in operating the device most efficiently based on the need. A rotating movement of 180 degrees of the D shaped hand grip when it is parallel to the ground produces change in blade body position from snow pusher to snow shovel or visa a versa. In between these two settings are 6 other option available to user for simultaneously side shifting of snow towards left or right while pushing.
BRIEF DESCRIPTION OF DRAWINGS
[0006] These and other features will become more apparent from the following description in which reference is made to the appended drawings, the drawings are for the purpose of illustration only and are not intended to be in any way limiting, wherein:
[0007] FIG. 1 is a front elevation view of a snow shovel and pusher combination. The setting or position could also be called as “mode”
[0008] FIG. 2 is a side elevation view of the snow shovel and pusher combination, set in pusher setting/mode
[0009] FIG. 3 is a side elevation view of the snow shovel and pusher combination, set in snow shovel setting/mode
[0010] FIG. 4 is a top elevation view of the snow shovel and pusher combination tilted 22.5 degrees towards left in snow shovel setting/mode
[0011] FIG. 5 is a top elevation view of the snow shovel and pusher combination tilted 22.5 degrees towards right in snow shovel setting/mode
[0012] FIG. 6 is a top elevation view of the snow shovel and pusher combination tilted 22.5 degrees towards left in snow pusher setting/mode
[0013] FIG. 7 is a top elevation view of the snow shovel and pusher combination tilted 22.5 degrees towards right in snow pusher setting/mode
[0014] FIG. 8 is a top elevation view of the snow shovel and pusher combination tilted 45 degrees towards left in snow shovel setting/mode
[0015] FIG. 9 is a top elevation view of the snow shovel and pusher combination tilted 45 degrees towards right in snow shovel setting/mode
[0016] FIG. 10 is a top elevation view of the snow shovel and pusher combination tilted 45 degrees towards left in snow pusher setting/mode
[0017] FIG. 11 is a top elevation view of the snow shovel and pusher combination tilted 45 degrees towards right in snow pusher setting/mode
[0018] FIG. 12A is the side view of the 360 degree rotating flange attached with the stationary flange of the rotating joint assembly
[0019] FIG. 12B is the steel bolt, nut and two washers for attaching the rotating flange with stationary flange of the rotating joint assembly
[0020] FIG. 13 is the rotating flange part of the rotating joint assembly
[0021] FIG. 14 is the stationary flange part of the rotating joint assembly
[0022] FIG. 15 is the cross section of the rotating flange part of the rotating joint assembly showing details in “X” axis
[0023] FIG. 16 is the cross section of the rotating flange part of the rotating joint assembly showing details in “Y” axis
[0024] FIG. 17 is the cross section of the stationary flange part of the rotating joint showing details in “Y” axis
[0025] FIGS. 18, 19, 20 and 21 are the side elevations of the rotating and stationary flanges of the rotating joint assembled together and rotated 90 degrees in each step
[0026] FIG. 22 is the side elevation of the blade body attached to rotating joint assembly showing Face line or “Blade Offset Angle” and “Handle Offset Angle”
[0027] FIGS. 23, 24, 25, 26, 27, 28, 29 and 30 are top view of the 360 degrees rotating flange of the rotating joint shown in 8 steps each of 45 degrees, rotated clockwise
DETAILED DESCRIPTION
[0028] The snow shovel and pusher combination with 8 adjustable settings will be described in details with reference to numbered parts
[0029] FIG. 1, 1 is the D shaped hand grip, 2 is the screw securing D shaped hand grip the long handle. 3 is the long handle. 4 is the screw securing the rotating flange to the long handle. Following are parts of the rotating joint 5 . Is the female receptacle to hold the other end of the long handle. 6 A and 6 B are the housings accommodating the two springs and steel balls for position locking. 7 is the rotating flange face. 8 is the stationary flange face, both faces touch each other and slide with lubrication in between, a nut, bolt and 2 washers (not visible) do the linking job. 9 is the stationary flange. 10 is the screw securing the stationary flange to the blade body and 11 is the blade body
[0030] FIG. 2 is the side view showing the snow shovel and pusher combination with 8 adjustable settings in pusher setting/mode. 1 is the D shaped hand grip. 2 is the screw securing D shaped hand grip to the long handle. 3 is the long handle and 11 is the blade body. The circled components are the 360 rotating joint assembly the rotating joint whose part details is shown in FIG. 12A
[0031] FIG. 3 is the side view showing the snow shovel and pusher combination with 8 adjustable settings in shovel setting/mode. 1 is the D shaped hand grip. 2 is the screw securing D shaped hand grip to the long handle. 3 is the long handle and 11 is the blade body. The circled components are the 360 degree rotating joint assembly the rotating joint whose part details is shown in FIG. 12A
[0032] FIG. 4 is a top elevation view of the snow shovel and pusher combination with 8 adjustable settings of FIG. 1 tilted 22.5 degrees towards left in Shovel Mode. 1 is the D shaped hand grip, 2 is the screw securing D shaped hand grip to the long handle. 3 is the long handle and 11 is the blade body. The circled components are the 360 degree rotating joint assembly the rotating joint whose part details are shown in FIG. 12A
[0033] FIG. 5 is a top elevation view of the snow shovel and pusher combination with 8 p adjustable settings of FIG. 1 tilted 22.5 degrees towards right in shovel mode. 1 is the D shaped hand grip, 2 is the screw securing D shaped hand grip to the long handle. 3 is the long handle and 11 is the blade body. The circled components are the 360 degree rotating joint assembly the rotating joint whose part details is shown in FIG. 12A
[0034] FIG. 6 is a top elevation view of the snow shovel and pusher combination with 8 adjustable settings of FIG. 1 tilted 22.5 degrees towards left in pusher mode. 1 is the D shaped hand grip, 2 is the screw securing D shaped hand grip to the long handle. 3 is the long handle and 11 is the blade body. The circled components are the 360 degree rotating joint assembly the rotating joint whose parts detail is shown in FIG. 12A
[0035] FIG. 7 is a top elevation view of the snow shovel and pusher combination with 8 adjustable settings of FIG. 1 tilted 22.5 degrees towards right in pusher mode. 1 is the D shaped hand grip, 2 is the screw securing D shaped hand grip to the long handle. 3 is the long handle and 11 is the blade body. The circled components are the 360 rotating joint assembly the rotating joint whose parts detail is shown in FIG. 12A
[0036] FIG. 8 is a top elevation view of the snow shovel and pusher combination with 8 adjustable settings of FIG. 1 tilted 45 degrees towards left in Shovel Mode. 1 is the D shaped hand grip, 2 is the screw securing D shaped hand grip to the long handle. 3 is the long handle and 11 is the blade body. The circled components are the 360 degree rotating joint assembly the rotating joint whose parts detail is shown in FIG. 12A
[0037] FIG. 9 is a top elevation view of the snow shovel and pusher combination with 8 p adjustable settings of FIG. 1 tilted 45 degrees towards right in Shovel Mode. 1 is D shaped hand grip, 2 is the screw securing D shaped hand grip to the long handle. 3 is the long handle and 11 is the blade body. The circled components are the 360 degree rotating joint assembly the rotating joint whose parts detail is shown in FIG. 12A
[0038] FIG. 10 is a top elevation view of the snow shovel and pusher combination with 8 adjustable settings of FIG. 1 tilted 45 degrees towards left in pusher mode. 1 is the D shaped hand grip. 2 is the screw securing D shaped hand grip to the long handle. 3 is the long handle and 11 is the blade body. The circled components are the 360 degree rotating joint assembly the rotating joint whose parts detail is shown in FIG. 12A
[0039] FIG. 11 is a top elevation view of the snow shovel and pusher combination with 8 adjustable settings of FIG. 1 tilted 45 degrees towards right in Pusher Mode. 1 is the D shaped hand grip. 2 is the screw securing D shaped hand grip to the long handle. 3 is the long handle and 11 is the blade body. The circled components are the 360 rotating joint assembly the rotating joint whose parts detail is shown in FIG. 12A
[0040] FIG. 12A is the side view of the rotating joint the rotating flange attached with the stationary flange. 4 is the screw for securing long handle to the stationary flange. 5 is the rotating flange. 6 A and 6 B are the housings to accommodate the two springs and steel balls (not visible) for locking. 7 is the flange face of the rotating joint. 8 is the face of the stationary flange. 9 is the stationary flange body. 10 is the screw for securing stationary flange with shovel blade body.
[0041] FIG. 12B 12 is the steel bolt. 13 is the vibration proof steel nut with nylon insert. 14 A and 14 B are the two plain steel washers. These four components are used to join together the two flanges namely the rotating flange and the stationary flange in such a manner that they can rotate while sliding over each other's circular face after lubrication but do not have any play or looseness.
[0042] FIG. 13 5 is the 360 degree rotating flange body which is part of the rotating joint. 4 is the screw to secure the rotating flange with the long handle. 6 A and 6 B are the housing for springs and balls for position locking. 7 is the flange face. 15 A is the hole to install steel bolt 12 and washer 14 A. 16 A and 16 B are the two spring loaded steel balls. 16 C and 16 D are the springs for steel balls shown with steel balls which are hidden inside the housings 6 A and 6 B
[0043] FIG. 14 9 is the stationary flange body which is part of the rotating joint. 8 is the stationary flange face. 10 is the screw for securing stationary flange to the shovel blade body. 15 B is the hole to install the steel nut 13 and washer 14 B. 17 , 18 , 19 , 20 , 21 , 22 , 23 and 24 are the 8 concave recesses at 45 degrees to each other with reference to the centre of the flange to accommodate the 2 spring loaded steel balls 16 A and 16 B from the 360 degrees rotating flange for locking purposes.
[0044] FIG. 15 These are the cross sections of 360 rotating flange part of the rotating joint on “X” axis. 25 is the bore for long handle 3 . 26 is the bore for steel bolt 12 . 6 A and 6 B are cavities which will house the steel balls 16 A and 16 B and springs 16 C and 16 D. 7 is the rotating flange face of the rotating joint.
[0045] FIG. 16 These are the cross sections of 360 rotating flange of the rotating joint. on “Y” axis. 25 is the bore for long handle 3 . 26 is the bore for steel bolt 12 to be inserted with washer 14 A. 6 A and 6 B are cavities shown which will house the springs 16 C and 16 D and steel balls 16 A and 16 B. 7 is the rotating flange face of the rotating joint.
[0046] FIG. 17 These are the cross sections of the stationary flange of the rotating joint. shown in “Y” axis. 27 is the bore for steel bolt 12 to accommodate the threaded side, washer 14 B and nut 13 at the lower end. 8 is the flange face. 9 is the stationary flange body. 10 is the screw to secure the flange to the shovel blade body. 17 , 18 , 19 , 20 , 21 , 22 , 23 and 24 are the 8 concave recesses to accommodate the spring loaded steel balls for each of the 8 positions from the 360 degree rotating flange of the rotating joint for locking purposes.
[0047] FIGS. 18, 19, 20 and 21 are the four positions of the 360 degree rotating flange joined with stationary flange shown from front elevation but rotated at 90 degrees from each other.
[0048] FIG. 22 , is the side elevation of the blade body attached to the rotating joint assembly showing the angle details of the blade body female receptacle and the rotary flange female receptacle. Line 31 indicates the rotational axis line of the rotary joint assembly, line 32 which is at 22.5 degrees in relation to line 31 indicates the long handle connection angle with D shaped handle at the end or “Handle Offset Angle”, line 30 indicates the face line angle of the blade body which is also at 22.5 degrees in relation to line 30 or “Blade Offset Angle”, line 30 A is a dotted line indicating a parallel line with the face line angle just to show more clarity.
[0049] FIGS. 23, 24, 25, 26, 27, 28, 29 and 30 are top elevation of rotating flange shown rotated at 45 degree increment clock wise. | The invention provides a single improved snow shovel and pusher combination with eight adjustable settings that is capable of providing the user an opportunity to adjust it according to their need during the process of snow removal from ground or the surface to be cleaned that could be but not limited to driveways, walkways, passages, stairs, docks and decks. To select any one of the 8 settings or adjustments of this invention, the D shaped hand grip needs to be rotated 45 degrees in clock wise direction which will change its setting or locking position. These multiple settings are useful in situations when the snow is also required to be pushed simultaneously towards right or left hand side while pushing forward before lifted and thrown away by using the snow shovel mode/setting. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of and claims the benefit under 35 U.S.C. § 120 of U.S. patent application Ser. No. 11/032,823, entitled Tri - State Circuit Using Nanotube Switching Elements and filed on Jan. 10, 2005 now U.S. Pat. No. 7,167,026, which is incorporated herein by reference in its entirety, which claims the benefit under 35 U.S.C. § 119(e) of U.S. Provisional patent application Ser. No. 60/581,071 , Nonvolatile Carbon Nanotube Logic ( NLOGIC ) Tri - state Circuit filed on Jun. 18, 2004, which is incorporated herein by reference in its entirety.
This application is related to the following references:
U.S. patent application Ser. No. 10/917,794, filed on Aug. 13, 2004, entitled Nanotube - Based Switching Elements; U.S. patent application Ser. No. 10/918,085, filed on Aug. 13, 2004, entitled Nanotube - Based Switching Elements With Multiple Controls; U.S. patent application Ser. No. 10/918,181, filed on Aug. 13, 2004, entitled Nanotube Device Structure And Methods Of Fabrication; U.S. patent application Ser. No. 10/917,893, filed on Aug. 13, 2004, entitled Nanotube - Based Switching Elements And Logic Circuits; U.S. patent application Ser. No. 10/917,606, filed on Aug. 13, 2004, entitled Isolation Structure For Deflectable Nanotube Elements; U.S. patent application Ser. No. 10/917,932, filed on Aug. 13, 2004, entitled Circuits Made From Nanotube - Based Switching Elements With Multiple Controls; U.S. patent application Ser. No. 11/033,087, filed on Jan. 10, 2005, entitled Nanotube - Based Transfer Devices and Related Circuits; U.S. patent application Ser. No. 11/033,089, filed on Jan. 10, 2005, entitled Integrated Nanotube and Field Effect Switching Device; U.S. patent application Ser. No. 11/033,213, filed on Jan. 10, 2005, entitled Receiver Circuit Using Nanotube - Based Switches and Transistors; U.S. patent application Ser. No. 11/033,215, filed on Jan. 10, 2005, entitled Receiver Circuit Using Nanotube - based Switches and Logic; U.S. patent application Ser. No. 11/032,216, filed on Jan. 10, 2005, entitled Nanotube - based Logic Driver Circuits ; and U.S. patent application Ser. No. 11/032,983, filed on Jan. 10, 2005, entitled Storage Elements Using Nanotube Switching Elements.
BACKGROUND
1. Technical Field
The present application relates in general to logic circuits and in particular to logic circuits constructed using nanotube switching elements.
2. Discussion of Related Art
Digital logic circuits are used in personal computers, portable electronic devices such as personal organizers and calculators, electronic entertainment devices, and in control circuits for appliances, telephone switching systems, automobiles, aircraft and other items of manufacture. Early digital logic was constructed out of discrete switching elements composed of individual bipolar transistors. With the invention of the bipolar integrated circuit, large numbers of individual switching elements could be combined on a single silicon substrate to create complete digital logic circuits such as inverters, NAND gates, NOR gates, flip-flops, adders, etc. However, the density of bipolar digital integrated circuits is limited by their high power consumption and the ability of packaging technology to dissipate the heat produced while the circuits are operating. The availability of metal oxide semiconductor (“MOS”) integrated circuits using field effect transistor (“FET”) switching elements significantly reduces the power consumption of digital logic and enables the construction of the high density, complex digital circuits used in current technology. The density and operating speed of MOS digital circuits are still limited by the need to dissipate the heat produced when the device is operating.
Digital logic integrated circuits constructed from bipolar or MOS devices do not function correctly under conditions of high heat or heavy radiation. Current digital integrated circuits are normally designed to operate at temperatures less than 100 degrees centigrade and few operate at temperatures over 200 degrees centigrade. In conventional integrated circuits, the leakage current of the individual switching elements in the “off” state increases rapidly with temperature. As leakage current increases, the operating temperature of the device rises, the power consumed by the circuit increases, and the difficulty of discriminating the off state from the on state reduces circuit reliability. Conventional digital logic circuits also short internally when subjected to heavy radiation because the radiation generates electrical currents inside the semiconductor material. It is possible to manufacture integrated circuits with special devices and isolation techniques so that they remain operational when exposed to heavy radiation, but the high cost of these devices limits their availability and practicality. In addition, radiation hardened digital circuits exhibit timing differences from their normal counterparts, requiring additional design verification to add radiation protection to an existing design.
Integrated circuits constructed from either bipolar or FET switching elements are volatile. They only maintain their internal logical state while power is applied to the device. When power is removed, the internal state is lost unless some type of non-volatile memory circuit, such as EEPROM (electrically erasable programmable read-only memory), is added internal or external to the device to maintain the logical state. Even if non-volatile memory is utilized to maintain the logical state, additional circuitry is necessary to transfer the digital logic state to the memory before power is lost, and to restore the state of the individual logic circuits when power is restored to the device. Alternative solutions to avoid losing information in volatile digital circuits, such as battery backup, also add cost and complexity to digital designs.
Important characteristics for logic circuits in an electronic device are low cost, high density, low power, and high speed. Resistance to radiation and the ability to function correctly at elevated temperatures also expand the applicability of digital logic. Conventional logic solutions are limited to silicon substrates, but logic circuits built on other substrates would allow logic devices to be integrated directly into many manufactured products in a single step, further reducing cost.
Recently, devices have been proposed which use nanoscopic wires, such as single-walled carbon nanotubes, to form crossbar junctions to serve as memory cells. (See WO 01/03208, Nanoscopic Wire-Based Devices, Arrays, and Methods of Their Manufacture; and Thomas Rueckes et al., “Carbon Nanotube-Based Nonvolatile Random Access Memory for Molecular Computing,” Science, vol. 289, pp. 94-97, 7 Jul., 2000.) Hereinafter these devices are called nanotube wire crossbar memories (NTWCMs). Under these proposals, individual single-walled nanotube wires suspended over other wires define memory cells. Electrical signals are written to one or both wires to cause them to physically attract or repel relative to one another. Each physical state (i.e., attracted or repelled wires) corresponds to an electrical state. Repelled wires are an open circuit junction. Attracted wires are a closed state forming a rectified junction. When electrical power is removed from the junction, the wires retain their physical (and thus electrical) state thereby forming a non-volatile memory cell.
U.S. Patent Publication No. 2003-0021966 discloses, among other things, electromechanical circuits, such as memory cells, in which circuits include a structure having electrically conductive traces and supports extending from a surface of a substrate. Nanotube ribbons that can electromechanically deform, or switch are suspended by the supports that cross the electrically conductive traces. Each ribbon comprises one or more nanotubes. The ribbons are typically formed from selectively removing material from a layer or matted fabric of nanotubes.
For example, a nanofabric may be patterned into ribbons, and the ribbons can be used as a component to create non-volatile electromechanical memory cells. The ribbon is electromechanically-deflectable in response to electrical stimulus of control traces and/or the ribbon. The deflected, physical state of the ribbon may be made to represent a corresponding information state. The deflected, physical state has non-volatile properties, meaning the ribbon retains its physical (and therefore informational) state even if power to the memory cell is removed. Three-trace architectures may be used for electromechanical memory cells, in which two of the traces are electrodes to control the deflection of the ribbon.
The use of an electromechanical bi-stable device for digital information storage has also been suggested.
The creation and operation of bi-stable, nano-electro-mechanical switches based on carbon nanotubes (including mono-layers constructed thereof) and metal electrodes has been detailed in previous patent applications of Nantero, Inc. (U.S. Pat. Nos. 6,574,130, 6,643,165, 6,706,402; U.S. patent application Ser. Nos. 09/915,093, 10/033,323, 10/033,032, 10/128,117, 10/341,005, 10/341,055, 10/341,054, 10/341,130, 10/776,059, 10/776,572, 10/917,794, and 10/918,085 the contents of which are hereby incorporated by reference in their entireties).
SUMMARY
The present invention provides logic circuits having a mode wherein the output can be set to a high-impedance condition. In various embodiments, the logic circuit and/or the tri-state feature may be implemented using nanotube switching elements and associated structures. In preferred embodiments, the logic circuits are implemented using complementary logic, particularly carbon nanotube-based complementary logic. In certain embodiments, the circuits thus combine the benefits of nanotube switching elements with the tri-state feature.
In certain embodiments, a pull-up tri-state element and a pull-down tri-state element are provided. The pull-up tri-state element is disposed between the upper power supply voltage and the pull-up logic circuitry. The pull-down tri-state element is disposed between the lower power supply voltage and the pull-down logic circuitry. Each tri-state element has a control structure for receiving a signal (or signals) that controls the activation of the element. The tri-state element is implemented using at least one nanotube-switching element.
In one aspect of the invention, a tri-state logic circuit includes an input terminal for receiving an input signal and an output terminal for providing an output signal. It also includes a pull-up network for connecting the output terminal to an upper power supply voltage, which is responsive to the input signal. The circuit further includes a first tristating nanotube switching element electrically connected in the signal path between the upper power supply voltage and the output terminal. The circuit also includes a pull-down network for connecting the output terminal to a lower power supply voltage, which is responsive to the input signal. A second tri-stating nanotube switching element is electrically connected in the signal path between the lower power supply voltage and the output terminal. The first and second nanotube switching elements are activated and deactivated to a tri-state control signal and the output terminal is tri-stated when the first and second nanotube switching elements are not activated.
In one aspect of the invention, the circuit implements a Boolean function.
In another aspect of the invention, the circuit implements an inverting function.
In another aspect of the invention, the pull-up network and the pull-down network are constructed of nanotube switching elements.
In another aspect of the invention, the first and second tri-stating nanotube switching elements are volatile.
In another aspect of the invention, the first and second tri-stating nanotube switching elements are non-volatile.
In another aspect of the invention, the first and second tri-stating nanotube switching elements are four-terminal devices.
In another aspect of the invention, a tri-state logic circuit, includes an input terminal for receiving an input signal and an output terminal for providing an output signal. A network of nanotube switching elements is connected between the input terminal and the output terminal such that it implements a Boolean transformation of the input signal to generate the output signal. A tri-stating nanotube switching element is connected to the network, activated by a tri-state control signal, and arranged so that the output terminal is tri-stated when the tri-stating nanotube switching element is not activated.
In one aspect of the invention, the nanotube switching elements in the network are volatile.
In another aspect of the invention, the nanotube switching elements in the network are non-volatile.
In another aspect of the invention, the tri-stating nanotube switching element is volatile.
In another aspect of the invention, the tri-stating nanotube switching element is non-volatile.
In another aspect of the invention, the tri-stating nanotube switching element is a four-terminal device.
In another aspect of the invention, an inverter circuit includes a dual-rail differential input, for receiving a first input signal and a first complementary input signal, and a dual-rail differential output, for providing a first output signal and a first complementary output signal. The circuit further includes a first inverter for inverting the first input signal to generate said first output signal, and a first tri-stating nanotube switching element pair connected to said first inverter. The circuit further includes a second inverter for inverting said first complementary input signal to generate said first complementary output signal, and a second tri-stating nanotube switching element pair connected to said second inverter. The circuit further includes a dual-rail differential control input, for receiving a first control input signal and a first complementary control input signal provided to cooperatively activate and deactivate the first tri-stating element pair and the second tri-stating element pair. The dual-rail differential output is in a floating state when the first tri-stating element pair and the second tri-stating element pair are deactivated.
In another aspect of the invention, the first inverter and the second inverter are constructed from nanotube switching elements.
In another aspect of the invention, the nanotube switching elements of the first inverter and the second inverter are volatile.
In another aspect of the invention, the nanotube switching elements of the first inverter and the second inverter are non-volatile.
In another aspect of the invention, the nanotube switching elements of the first and second tri-stating element pairs are volatile.
In another aspect of the invention, the nanotube switching elements of the first and second tri-stating element pairs are non-volatile.
The provision of a high-impedance state for the output allows the outputs of multiple inverters to be connected together to form busses, logic decoders, or other circuits. Certain embodiments may offer certain advantages. For example, there is no significant leakage current between input and output terminals in the “OFF” state of a complementary nanotube-based device, and there is no junction leakage. The nanotube devices may operate in harsh environments such as elevated temperatures, e.g., 150 to 200 deg-C or higher. The nanotube devices do not exhibit alpha particle sensitivity.
The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A-C and 2 A-C illustrate differential logic inverters according to certain embodiments of the invention;
FIGS. 3A-D are illustrations of an exemplary nanotube switching element used in certain embodiments of the invention; and
FIGS. 4A-C are schematic representations of a nanotube switching element in various states of operation according to an embodiment of the invention.
DETAILED DESCRIPTION
The present invention provide tri-state nanotube logic circuits constructed from one or more nanotube-switching elements. The use of some embodiments of such devices offers a solution to the CMOS problems of power dissipation and radiation sensitivity. In certain embodiments, the present invention uses electromechanical switches including carbon nanotube channel elements to build complementary nanotube logic. Nanotube-based pull-up and pull-down circuits can be connected to form complementary circuits that only dissipate power when switching. In embodiments of the invention, the circuits are tri-state circuits that have a mode wherein the output can be set to a high-impedance condition. In certain embodiments, the circuits thus combine the benefits of nanotube switching elements with the tri-state feature. For complementary logic circuits, a pull-up tri-state element and a pull-down tri-state element are provided. In certain embodiments, the pull-up tri-state element is disposed between the upper power supply voltage and the pull-up tri-state logic circuitry. The pull-down element is disposed between the lower power supply voltage and the pull-down logical circuitry. Each tri-state element has a control structure for receiving a signal (or signals) that turns the element ON and OFF. The tri-state element is implemented using at least one nanotube-switching element. The provision of a high-impedance state for the output allows the outputs of multiple inverters to be connected together to form logic busses, logic decoders, or other logic circuits. There is no significant leakage current between input and output terminals in the “OFF” state of a complementary nanotube-based device, and there is no junction leakage. The nanotube devices may operate in harsh environments such as elevated temperatures, e.g., 150 to 200 deg-C or higher. There is no alpha particle sensitivity. The interconnect wiring used to interconnect the nanotube device terminals may be conventional wiring such as AlCu, W, or Cu wiring with appropriate insulating layers such as SiO 2 , polyimide, etc, or may be single or multi-wall nanotubes used for wiring.
Preferred embodiments of the invention provide device control inputs to switch the complementary logic outputs of an inverter from a low impedance logic zero and logic one state to a high impedance floating state. Outputs from multiple logic devices providing tri-state logic may be connected together, as long as only a single device is enabled to the low impedance state to drive the common output. The use of logic circuits providing a third, high impedance state to create bus structures and logic decoders is well known. The technology can be used in all present memory devices such as DRAM, SRAM, Flash, EEPROM, PROM, etc. Also, logic functions such as microprocessor, adders, random logic, PLAs, FPGAs, etc. can be fabricated with this invention.
Aspects of the invention are demonstrated herein by reference to a device that implements an inverting logic function. FIG. 1A illustrates an exemplary differential (dual-rail input and dual-rail output) logic inverter 10 , in which aspects of the invention may be used. The inverter 10 is constructed from four non-volatile nanotube switches 24 , 26 , 34 , and 36 , arranged in two inverters, a first inverter 20 and a second inverter 30 . FIGS. 1B and 1C illustrate operation of inverter 10 . (The schematic notation is discussed below with respect to FIGS. 4A-C .) FIG. 2A illustrates an exemplary tri-statable differential (dual-rail input and dual-rail output) logic inverter 50 . Tri-statable differential logic inverter 50 also includes inverters 20 and 30 , and each inverter 20 and 30 is connected to a pull-up tristating element provided by a nanotube switch 52 , 62 and a pull-down tri-stating element provided by a nanotube switch 56 , 66 .
The operation of inverters 10 and 50 is better understood by reference to the operation of exemplary nanotube switching elements. FIGS. 3A-D depict an exemplary nanotube switching element 300 in cross-section and layout views and in two informational states for use in certain embodiments of the invention. A more detailed description of these switches and other architectures for nanotube switching elements may be found in the related cases identified and incorporated above. Non-volatile four-terminal nanotube switching elements are described in U.S. patent application Ser. No. 10/918,085, which is incorporated by reference above. A summary description follows here for convenience.
FIG. 3A is a cross sectional view of a preferred nanotube switching element 100 . Nanotube switching element includes a lower portion having an insulating layer 117 , control electrode 111 , and output electrodes 113 c,d . Nanotube switching element further includes an upper portion having release electrode 112 , output electrodes 113 a,b , and signal electrodes 114 a,b . A nanotube channel element 115 is positioned between and held by the upper and lower portions.
Release electrode 112 is made of conductive material and is separated from nanotube channel element 115 by an insulating material 119 . The channel element 115 is separated from the facing surface of insulator 119 by a gap height G 102 .
Output electrodes 113 a,b are made of conductive material and are separated from nanotube channel element 115 by insulating material 119 .
Output electrodes 113 c,d are likewise made of conductive material and are separated from nanotube channel element 115 by a gap height G 103 . Notice that the output electrodes 113 c,d are not covered by insulator.
Control electrode 111 is made of conductive material and is separated from nanotube channel element 115 by an insulating layer (or film) 118 . The channel element 115 is separated from the facing surface of insulator 118 by a gap height G 104 .
Signal electrodes 114 a,b each contact the nanotube channel element 115 and can therefore supply whatever signal is on the signal electrode to the channel element 115 . This signal may be a fixed reference signal (e.g., V DD or Ground) or varying (e.g., a Boolean discrete value signal that can change). Only one of the electrodes 114 a,b need be connected, but both may be used to reduce effective resistance.
Nanotube channel element 115 is a lithographically-defined article made from a porous fabric of nanotubes (more below). It is electrically connected to signal electrodes 114 a,b . The electrodes 114 a,b and support 116 pinch or hold the channel element 115 at either end, and it is suspended in the middle in spaced relation to the output electrodes 113 a - d and the control electrode 111 and release electrode 112 . The spaced relationship is defined by the gap heights G 102 -G 104 identified above. For certain embodiments, the length of the suspended portion of channel element 115 is about 300 to 350 nm.
Under certain embodiments the gaps G 103 , G 104 , G 102 are in the range of 5-30 nm. The dielectric on terminals 112 , 111 , and 113 a and 113 b are in the range of 5-30 nm, for example. The carbon nanotube fabric density is approximately 10 nanotubes per 0.2×0.2 um area, for example. The suspended length of the nanotube channel element is in the range of 300 to 350 nm, for example. The suspended length to gap ratio is about 5 to 15 to 1 for non-volatile devices, and less than 5 for volatile operation, for example.
FIG. 3B is a plan view or layout of nanotube switching element 100 . As shown in this figure, electrodes 113 b,d are electrically connected as depicted by the notation ‘X’ and item 102 . Likewise electrodes 113 a,c are connected as depicted by the ‘X’. In preferred embodiments the electrodes are further connected by connection 120 . All of the output electrodes collectively form an output node 113 of the switching element 100 .
Under preferred embodiments, the nanotube switching element 100 of FIGS. 3A and 3B operates as shown in FIGS. 3C and D. Specifically, nanotube switching element 100 is in an OPEN (OFF) state when nanotube channel element is in position 122 of FIG. 3C . In such state, the channel element 115 is drawn into mechanical contact with dielectric layer 119 via electrostatic forces created by the potential difference between electrode 112 and channel element 115 . Output electrodes 113 a,b are in mechanical contact (but not electrical contact) with channel element 115 . Nanotube switching element 100 is in a CLOSED (ON) state when channel element 115 is elongated to position 124 as illustrated in FIG. 3D . In such state, the channel element 115 is drawn into mechanical contact with dielectric layer 118 via electrostatic forces created by the potential difference between electrode 111 and channel element 115 . Output electrodes 113 c,d are in mechanical contact and electrical contact with channel element 115 at regions 126 . Consequently, when channel element 115 is in position 124 , signal electrodes 114 a and 114 b are electrically connected with output terminals 113 c,d via channel element 115 , and the signal on electrodes 114 a,b may be transferred via the channel (including channel element 115 ) to the output electrodes 113 c,d.
By properly tailoring the geometry of nanotube switching element 100 , the nanotube switching element 100 may be made to behave as a non-volatile or a volatile switching element. By way of example, the device state of FIG. 3D may be made to be non-volatile by proper selection of the length of the channel element relative to the gap G 104 . (The length and gap are two parameters in the restoring force of the elongated, deflected channel element 115 .) Length to gap ratios of greater than 5 and less than 15 are preferred for non-volatile device; length to gap ratios of less than 5 are preferred for volatile devices.
The nanotube switching element 100 operates in the following way. If signal electrode 114 and control electrode 111 (or 112 ) have a potential difference that is sufficiently large (via respective signals on the electrodes), the relationship of signals will create an electrostatic force that is sufficiently large to cause the suspended, nanotube channel element 115 to deflect into mechanical contact with electrode 111 (or 112 ). (This aspect of operation is described more fully in the incorporated patent references.) This deflection is depicted in FIGS. 3D (and 3 C). The attractive force stretches and deflects the nanotube fabric of channel element 115 until it contacts the insulated region 118 of the electrode 111 . The nanotube channel element is thereby strained, and there is a restoring tensile force, dependent on the geometrical relationship of the circuit, among other things.
By using appropriate geometries of components, the switching element 100 then attains the closed, conductive state of FIG. 3D in which the nanotube channel 115 mechanically contacts the control electrode 111 and also output electrode 113 c,d . Since the control electrode 111 is covered with insulator 118 any signal on electrode 114 is transferred from the electrode 114 to the output electrode 113 via the nanotube channel element 115 . The signal on electrode 114 may be a varying signal, a fixed signal, a reference signal, a power supply line, or ground line. The channel formation is controlled via the signal applied to the electrode 111 (or 112 ). Specifically the signal applied to control electrode 111 needs to be sufficiently different in relation to the signal on electrode 114 to create the electrostatic force to deflect the nanotube channel element to cause the channel element 115 to deflect and to form the channel between electrode 114 and output electrode 113 , such that switching element 100 is in the CLOSED (ON) state.
In contrast, if the relationship of signals on the electrode 114 and control electrode 111 is insufficiently different, then the nanotube channel element 115 is not deflected and no conductive channel is formed to the output electrode 113 . Instead, the channel element 115 is attracted to and physically contacts the insulation layer on release electrode 112 . This OPEN (OFF) state is shown in FIG. 3C . The nanotube channel element 115 has the signal from electrode 114 but this signal is not transferred to the output node 113 . Instead, the state of the output node 113 depends on whatever circuitry it is connected to and the state of such circuitry. The state of output node 113 in this regard is independent of channel element voltage from signal electrode 114 and nanotube channel element 115 when the switching element 100 is in the OPEN (OFF) state.
If the voltage difference between the control electrode 111 (or 112 ) and the channel element 115 is removed, the channel element 115 returns to the non-elongated state (see FIG. 3A ) if the switching element 100 is designed to operate in the volatile mode, and the electrical connection or path between the electrode 115 to the output node 113 is opened.
Preferably, if the switching element 100 is designed to operate in the non-volatile mode, the channel element is not operated in a manner to attain the state of FIG. 3A . Instead, the electrodes 111 and 112 are expected to be operated so that the channel element 115 will either be in the state of FIG. 3C or 3 D.
The output node 113 is constructed to include an isolation structure in which the operation of the channel element 115 and thereby the formation of the channel is invariant to the state of the output node 113 . Since in the preferred embodiment the channel element is electromechanically deflectable in response to electrostatically attractive forces, a floating output node 113 in principle could have any potential. Consequently, the potential on an output node may be sufficiently different in relation to the state of the channel element 115 that it would cause deflection of the channel element 115 and disturb the operation of the switching element 100 and its channel formation; that is, the channel formation would depend on the state of an unknown floating node. In the preferred embodiment this problem is addressed with an output node that includes an isolation structure to prevent such disturbances from being caused.
Specifically, the nanotube channel element 115 is disposed between two oppositely disposed electrodes 113 b,d (and also 113 a,c ) of equal potential. Consequently, there are opposing electrostatic forces that result from the voltage on the output node. Because of the opposing electrostatic forces, the state of output node 113 cannot cause the nanotube channel element 115 to deflect regardless of the voltages on output node 113 and nanotube channel element 115 . Thus, the operation and formation of the channel is made invariant to the state of the output node.
Under certain embodiments of the invention, the nanotube switching element 100 of FIG. 3A may be used as a pull-up or pull-down device to form power-efficient circuits. Unlike MOS and other forms of circuits, in complementary circuits, the nanotube based pull-up and pull-down devices may be identical devices and need not have different sizes or materials. To facilitate the description of such circuits and to avoid the complexity of the layout and physical diagrams of FIGS. 3A-D , a schematic representation shown in FIGS. 4A-C has been developed to depict the switching elements. The nodes identified by the same reference numerals in FIGS. 4A-C correspond to the structures shown in FIGS. 3A-D . The thick black line 204 represents the nanotube channel element and more particularly its contact state. In FIG. 4B , the nanotube channel element is insulated from the output terminal and the device is OFF. In FIG. 4C , the nanotube channel element is in electrical contact with the output terminal and the device is ON.
In summary, a four-terminal nanotube switching element includes a nanotube channel element that provides a controllably formable conductive channel from an input terminal to an output terminal. The input terminal is permanently in electrical contact with the channel element. The input terminal is connected to an input signal that is preferably fixed or has a known potential. A control input provided via a control terminal controls the formation of the conductive channel. A release input, which is complementary to the control input in preferred embodiments, provided via a release terminal resets the nanotube channel element from an ON state to an OFF state.
Referring again to FIGS. 1A and 2A , inverter 20 has a first logical input A applied to input terminal 22 , a second logical input A C applied via terminal 32 , and a logical output Aout provided on output terminal 28 . The control electrodes of switching elements 34 and 36 are tied together to input terminal 22 . The release electrodes of switching elements 24 and 26 are tied together to input terminal 32 . In preferred embodiments, A C is the logical complement of signal A. The control and release electrodes are thus operated in a complementary fashion, ensuring that each nanotube switching element is in a known state during operation of the device 10 . The signal electrode of nonvolatile device 24 is connected to voltage V DD (the upper power supply voltage) and the signal electrode of nonvolatile device 26 is connected to ground (the lower power supply voltage). In operation, a nanotube switching element, having the architecture used in preferred embodiments of the invention for switching elements 24 , 26 , 34 and 36 , inherently implements an inverting function. The switching element is activated by a potential difference between the signal electrode and the control and/or release electrode. Switching elements 24 and 26 are arranged to invert signal A. Only one of switches 24 and 26 will be conducting for a given value of differential signal A/A C , and output 28 will be connected to either V DD (when A is logically zero) or GND (when A is logically one).
Inverter 30 has a first logical input A C applied to input terminal 32 , a second logical input A applied via terminal 22 , and a logical output Aout C provided on output terminal 38 . The control electrodes of switching elements 34 and 36 are tied together to input terminal 32 . The release electrodes of switching elements 34 and 36 are also tied together to input terminal 22 . The signal electrode of switching element 34 is connected to voltage V DD , and the signal electrode of switching element 36 is connected to ground. Together, switching elements 34 and 36 operate like switching elements 24 and 26 to invert the input, but switching elements 34 and 36 are connected to logical input A C . Switching elements 34 and 36 are arranged to invert signal A C . Combined first and second inverters 20 and 30 , and associated interconnections and supply voltages, comprise differential inverter 10 .
FIG. 1B illustrates inverter state of inverter 10 when input A is positive (V DD ) and input A C is ground. In switching element 24 , the nanotube element is attracted to the insulated release electrode and does not conduct. In switching element 26 , the nanotube element is attracted by the control electrode to contact the output electrode, forming a conductive path from GND to output terminal 28 . In switching element 34 , the nanotube switching element is likewise attracted by the control electrode to contact the output electrode, forming a conductive path from V DD to output terminal 38 . In switching element 36 , the nanotube element is attracted to the insulated release electrode and does not conduct. In summary, inverter output 28 is at 0 volts, connected to ground by switch 26 , and inverter output 38 is positive, connected to V DD by switch 34 .
FIG. 1C illustrates inverter 10 in a second state when input A is zero and input A C is positive (V DD ). In switching element 24 , the nanotube element is attracted by the control electrode to contact the output electrode, forming a conductive path from V DD to output terminal 28 . In switching element 26 , the nanotube element is attracted to the insulated release electrode and does not conduct. In switching element 34 , the nanotube element is attracted to the insulated release electrode and does not conduct. In switching element 36 , the nanotube switching element is likewise attracted by the control electrode to contact the output electrode, forming a conductive path from GND to output terminal 38 . In summary, inverter output 28 is at 0 volts, connected to ground by switch 26 , and inverter output 38 is positive, connected to V DD by switch 34 . In operation, output Aout of inverter 10 is the logical inversion of input A and output Aout C of inverter 10 is the logical inversion of input A C (or, in other words, is equivalent to signal A).
FIG. 2A illustrates a preferred embodiment of a differential logic tri-state inverter circuit 50 formed of inverters 20 and 30 illustrated in FIG. 1A , and non-volatile nanotube switching elements 52 , 56 , 62 and 66 and associated interconnections. Switching elements 52 , 56 , 62 and 66 are controlled by a signal C 1 and its complement C 1 C . Switching elements 52 , 56 , 62 and 66 are activated only when C 1 is high. Otherwise, switching elements 52 , 56 , 62 and 66 are in the OFF state, and in this condition, inverter 50 is tri-stated and the output is effectively disconnected, regardless of the values of input signal A and A C .
Switching element 52 is electrically disposed between the power supply voltage and the pull-up circuit of inverter 20 . Switching element 52 is controlled by a tri-state control input 53 and tri-state release input 54 . Tri-state control input 53 and tri-state release input 54 are connected to complementary tri-state control signals C 1 C and C 1 , respectively. Because switching element 52 is connected to V DD , switching element 52 is activated when the signal on input 53 is low, and it must be controlled by C 1 C , a signal with inverse polarity to C 1 , to obtain the desired operation. Switching element 56 is electrically disposed between the GND connection and the pull-down circuit of inverter 20 .
FIG. 2B illustrates tri-state inverter 50 in a first physical and electrical state nanotube switching elements 52 , 56 , 62 and 66 are in the “OFF” state, with the nanotube elements in contact with insulated opposing output electrodes. The signal electrodes of nanotube switching elements 24 and 26 and 34 and 36 are not connected to power supply lines. Accordingly, V DD and ground voltages are not applied to the inverter devices and no inverter operation takes place. Output voltages of signals Aout and Aout C are not defined.
The tri-stating function operates like an enable/disable feature. The tri-stated output allows the circuit 50 to share the same signal path as other circuits. Tri-state inverter 50 has a number of applications, such as sharing a common bus (not shown) with other circuits. When tri-state inverter 50 is tri-stated, or in the “OFF” state, bus operation is controlled by other circuits (not shown).
FIG. 2C illustrates tri-state inverter 50 in a second physical and electrical state nanotube switching elements 52 , 56 , 64 , and 66 are in the “ON” state, with the nanotube elements in contact with corresponding output electrodes. Power supply voltage V DD is applied to nanotube switching elements 24 and 34 , and ground is applied to nanotube switching elements 26 and 36 . With tri-state inverter in the “ON” state, inverter operation as described with respect to FIG. 1 resumes. In the “ON” state, tri-state inverter 100 controls (drives) a shared bus (not shown) or other circuits interconnected to the differential outputs 28 and 38 .
The nanotube switching elements of preferred embodiments are non-volatile. Inverter 50 thus can retain both its logical state and its enable state if power to the circuit is removed or interrupted. The original state is present when power to the circuit is resumed. This property has a number of applications and advantages, including power failure protection and memory functions.
The following are assigned to the assignee of this application, and are hereby incorporated by reference in their entirety:
U.S. patent application Ser. No. 10/341,005, filed on Jan. 13, 2003, entitled Methods of Making Carbon Nanotube Films, Layers, Fabrics, Ribbons, Elements and Articles; U.S. patent application Ser. No. 09/915,093, filed on Jul. 25, 2001, entitled Electromechanical Memory Array Using Nanotube Ribbons and Method for Making Same; U.S. patent application Ser. No. 10/033,032, filed on Dec. 28, 2001, entitled Methods of Making Electromechanical Three - Trace Junction Devices; U.S. patent application Ser. No. 10/033,323, filed on Dec. 28, 2001, entitled Electromechanical Three - Trace Junction Devices; U.S. patent application Ser. No. 10/128,117, filed on Apr. 23, 2002, entitled Methods of NT Films and Articles; U.S. patent application Ser. No. 10/341,055, filed Jan. 13, 2003, entitled Methods of Using Thin Metal Layers to Make Carbon Nanotube Films, Layers, Fabrics, Ribbons, Elements and Articles; U.S. patent application Ser. No. 10/341,054, filed Jan. 13, 2003, entitled Methods of Using Pre - formed Nanotubes to Make Carbon Nanotube Films, Layers, Fabrics, Ribbons, Elements and Articles; U.S. patent application Ser. No. 10/341,130, filed Jan. 13, 2003, entitled Carbon Nanotube Films, Layers, Fabrics, Ribbons, Elements and Articles; U.S. patent application Ser. No. 10/776,059, filed Feb. 11, 2004, entitled Devices Having Horizontally - Disposed Nanofabric Articles and Methods of Making The Same; U.S. patent application Ser. No. 10/776,572, filed Feb. 11, 2004, entitled Devices Having Vertically - Disposed Nanofabric Articles and Methods of Making the Same;
Preferred embodiments of the invention are compatible with CMOS circuits and can be manufactured in an integrated way with CMOS circuits. It is contemplated that certain embodiments of the invention can be used interchangeably with existing field effect device implementations, e.g., CMOS implementations. CMOS designs can readily be converted to nanotube switch designs. Storage devices constructed according to the invention can be substituted for CMOS cells in larger CMOS circuits without impacting other portions of the original design. New designs combining nanotube switch technology with CMOS technology can readily be created by using embodiments of present invention with components selected from a CMOS device library.
In view of the wide variety of embodiments to which the principles of the present invention can be applied, it should be understood that the illustrated embodiments are exemplary only, and should not be taken as limiting the scope of the present invention. Preferred embodiments use the nanotube-based switches of the incorporated related references. As described therein, many volatile and non-volatile configurations may be used. Combinations of different configurations may also be used. These switches may then be arranged and sized based on the requirements of a particular application, limitations of certain fabrication techniques, etc. While single walled carbon nanotube channel elements are preferred, multi-walled carbon nanotubes may also be used. Also, nanotubes may be used in conjunction with nanowires. Nanowires as referenced herein includes single nanowires, aggregates of non-woven nanowires, nanoclusters, nanowires entangled with nanotubes comprising a nanofabric, mattes of nanowires, etc. While carbon nanotube channel elements are preferred, it is contemplated that other nanotube channel elements may also be used in some embodiments.
Other aspects, modifications, and embodiments are within the scope of the following claims. The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of the equivalency of the claims are therefore intended to be embraced therein. | Nanotube-based logic circuitry is disclosed. Tri-stating elements add an enable/disable function to the circuitry. The tri-stating elements may be provided by nanotube-based switching devices. In the disabled state, the outputs present a high impedance, i.e., are tri-stated, which state allows interconnection to a common bus or other shared communication lines. In embodiments wherein the components are non-volatile, the inverter state and the control state are maintained in the absence of power. Such an inverter may be used in conjunction with and in the absence of diodes, resistors and transistors or as part of or as a replacement to CMOS, biCMOS, bipolar and other transistor level technologies. | 8 |
BACKGROUND OF THE INVENTION
This invention is directed to high surface area monolithic structures composed of sintered ceramic oxide materials which have high porosity. The structures are useful as filters for fluids and as catalytic substrates in that they provide high surface area for particular filtration or for deposition of catalytic material. The invention is more particularly directed to structures in which the ceramic material is primarily alumina, titania, or zirconia which has been modified, prior to firing or sintering, by admixture with a phosphate material that generates P 2 O 5 upon heating. The structures are particularly useful as catalyst supports in the conversion of automotive exhausts and in reduction of NOx emissions from industrial sources, and as fluid filters, such as those used in diesel engines.
Conventional monolithic ceramic catalyst supports consist of an underlying ceramic support material with a coating of high surface area material upon which the catalyst itself is actually deposited. In particular, the ceramic support is prepared by sintering a mold of clay or other ceramic oxide (alumina, titania, cordierite, etc.) at a temperature sufficiently high to densify and strengthen the material. Temperatures high enough to result in effective sintering, however, also cause pore shrinkage and other microstructural changes that result in the sintered material's having a very low surface area. Consequently, the sintered ceramic must be coated with another material having a higher surface area, often a ceramic material itself that has not been sintered or pre-reacted, on which to actually deposit the catalyst. This procedure of applying a high surface area "wash-coat" on the low surface area ceramic wall is disclosed, for example, in U.S. Pat. Nos. 2,742,437 and 3,824,196.
In addition to the exposure to high temperature during sintering, however, catalyst support structures can also be exposed to elevated temperatures in service. The surface area of a wash-coat can be substantially degraded, and the surface area of the underlying ceramic may also further be reduced in some instances, because of the high service temperatures, such as those of automotive exhaust gases, to which they are exposed. It is therefore desirable to use ceramic materials that are, or can be modified to be, resistant to loss of surface area when exposed to elevated temperatures either during firing or service. One such material is a mixture of 50-93% by weight alumina and 7-50% by weight silica as disclosed in U.S. Pat. No. 4,631,269 (Lachman et al, issued Dec. 23, 1986).
It is an object of the present invention to provide an improved monolithic structure that can be sintered to provide structural strength and integrity without loss of appreciable surface area. It is a further object of the invention to provide a structure that resists thermal degradation of its porosity and available surface area despite exposure to elevated temperatures in catalytic conversion processes.
SUMMARY OF THE INVENTION
The present invention provides an improved monolithic structure, useful as a filter or catalyst support, comprising (1) a sintered ceramic phase of a porous metal oxide, at least 50% by weight of which is alumina, titania, and/or zirconia, and (2) about 0.5-35% by weight of P 2 O 5 (based on the total weight of the P 2 O 5 and the alumina, titania, and/or zirconia) substantially dispersed throughout the porous metal oxide phase. In preferred embodiments directed to its use as a catalyst support structure, the monolith further contains catalytic metals, such as transition metals (including rare earth metals), or their oxides, distributed throughout the sintered ceramic phase of porous metal oxide or on the surfaces of the porous metal oxide.
The combination of P 2 O 5 with ceramic oxide material as described herein provides a supporting substrate for catalyst that retains high surface area and effective pore size distribution despite being subjected to the elevated temperatures of ceramic firing and catalytic service. Efficient catalytic activity, which is dependent on surface area and porosity, can therefore be maintained over longer service periods.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graph depicting the surface area retained, after firing, of a P 2 O 5 -containing alumina material of the present invention.
FIG. 2 is a graph depicting the surface area retained, after firing, of a P 2 O 5 -containing titania material of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
According to the present invention, a sintered monolithic structure is provided which comprises a high surface area of porous ceramic metal oxide, at least 50% by weight of which is alumina, titania, and/or zirconia, and about 0.5-35% by weight of P 2 O 5 or equivalent phosphate-containing compound dispersed substantially throughout the porous metal oxide material. The structure is prepared by admixing the porous oxide material and a phosphate material capable of generating P 2 O 5 at or below the firing temperature, forming the admixture into a desired shape, and firing the shape according to conventional techniques of the ceramic arts to form a structure having substantial strength and high surface area. It has been found that the presence of the phosphate material, in intimate mixture with the ceramic porous oxide material, permits the oxide to be fired to an effective level of strength while retaining an acceptable surface area and catalytically-effective pore size distribution.
The porous oxide materials suitable for use are those which, after calcining, have a surface area of at least 20 square meters per gram, preferably at least 100 square meters per gram, and most preferably at least 200 square meters per gram. (As used herein, "calcining" means heating a material to a temperature sufficiently high to substantially eliminate volatiles but below the temperature at which the material begins to densify.) At least 50% by weight of the porous oxide material is alumina, titania, zirconia, or a mixture of these three. The balance, if any, of the porous oxide material can be any other ceramic material that has commonly been used as a catalyst support in the past and which has the above-described characteristics. Preferably, the porous oxide material is at least 75-80% by weight of alumina, titania, and/or zirconia (hereinafter, the "core metal oxides"). In particularly preferred embodiments, substantially all the porous oxide material is one or more of these core metal oxides.
The aluminas useful as the porous metal oxide are those which, upon calcining or firing, provide gamma-alumina or other transition aluminas having the specified surface area. Colloidal gamma-alumina can be used directly or materials which generate a transition alumina upon calcining, such as alpha-alumina monohydrate or alumina trihydrate, can also be used. The colloidal gamma-alumina is generally in the form of particles of 1 micron size or less. When alpha-alumina monohydrate or alumina trihydrate is used, the particle size can be from less than 1 micron up to 100 microns, but preferably less than about 75-80 microns. Suitable commercially available materials of this kind are Kaiser SA substrate alumina, CATAPAL alumina available from Vista Chemical Company, and DISPURAL alumina monohydrate from Remet Chemical Corporation.
The alumina component can also be introduced in the form of a precursor such as a hydrated alumina, a hydrolyzed aluminum alkoxide, or aluminum chlorohydrate. The hydrated aluminas are preferably in the form of an aqueous suspension and are commercially available, for example, from the Ethyl Corp. The most preferable aluminum alkoxide is hydrolyzed aluminum isopropoxide, which is commercially available as a dispersion in alcohol. For example, a dispersion of aluminum isopropoxide, 30-35% by weight in isobutanol, is available from the Alpha Products Division of Morton Thiokol Inc. Aluminum chlorohydrate is available in the form of an aqueous solution, for example, as CHLORHYDROL 50% or REHABOND CB-65S from Reheis Chemical Co. Aluminum chlorohydrate is also available in solid particulate form, for example as CHLORHYDROL Powder from Reheis Chemical Co.
High surface area titanias suitable for use as the ceramic porous metal oxide of this invention are commercially available, for example, from the Degussa Corporation as P25 TiO 2 . The titania can also be introduced in the form of a precursor such as a suspension of an amorphous hydrated titanium oxide, which can be in the form of a hydrolyzed titanium alkoxide, such as titanium isopropoxide (tetraisopropyl titanate), or a slurry of titanium hydrate. Slurries of titanium hydrate are commercially available, for example from SCM Corp. In all cases, the solid titania or solid portion of the titania precursor is generally in particulate form with a primary particle size less than about 100 microns, preferably less than about 75-80 microns, and more preferably less than 20 microns.
The zirconia material useful in the practice of the invention can generally be in any form heretofore used in the ceramic arts. Generally, a pre-reacted zirconia in particulate form with a primary particle size in the same ranges as described immediately above is used. The zirconia can also be added in the form of a precursor. The preferred precursor is a suspension of an amorphous hydrated zirconium oxide, which can be in the form of a hydrolyzed zirconium alkoxide (such as zirconium n-propoxide) or a slurry of zirconium hydrate.
Up to 50% by weight of the porous metal oxide material of the monolith can be composed of one or more ceramic metal oxides other than the above-described core metal oxides. This component of the monolith can be any of the well-known sinterable materials capable of providing mechanical strength and thermal properties in monolithic supports as heretofore prepared by those skilled in the art. Preferably this material is selected from cordierite, mullite, clay (preferably kaolin clay), talc, spinels, silicates such as lithium alumino-silicates, alpha alumina, aluminates, aluminum titanate, aluminum titanate solid solutions, stabilized zirconias, silica, glasses, and glass ceramics. Any mixture or combination of these materials can be used.
Spinels useful in the present invention are the magnesium aluminate spinels heretofore used as catalyst supports, including spinel solid solutions in which magnesium is partially replaced by such other metals as manganese, cobalt, zirconium, or zinc. Preferred spinels are magnesium aluminate spinels having 1-7% by weight alumina in excess of 1:1 MgO.Al 2 O 3 spinel; that is, those having about 72.0-73.5 weight percent Al 2 O 3 (balance MgO). Spinels of this kind can be prepared by coprecipitation or wet-mixing of precursors of alumina and magnesia, followed by drying and calcining. Such a procedure is described in U.S. Pat. No. 4,239,656, the disclosure of which is hereby incorporated by reference as filed. As a supplement to this disclosure, however, it has been found that calcining of the spinels should normally not exceed 1300° C. for 2-2.5 hours. Calcining temperatures below 1200° C. are preferred. Suitable alumina precursors for preparation of the spinels are hydrolyzed aluminum alkoxides or hydrated aluminas, both of which are commercially available. Magnesium oxide component powders found to be suitable are magnesium hydroxide slurry, about 40 weight percent MgO, available from Dow Chemical Company, or hydrated magnesium carbonate.
High surface area silicas that can be used in the practice of the present invention are the amorphous silicas of about 1-10 microns or sub-micron particle size such as Cabosil® EH-5 colloidal silica, available from Cabot Corporation. Colloidal silica derived from gels, such as Grade 952 from the Davison Chemical Division of W. R. Grace & Co. can also be used.
Cordierite, one of the preferred ceramic materials for use as the additional substrate material herein, can be in the precursor or "raw" form which becomes true cordierite upon heating, or can be used in pre-reacted form. When raw cordierite is used, it is preferred that up to 10% by weight, based on cordierite weight, of B 2 O 3 be added to the batch to initiate cordierite formation at lower than usual temperatures and to impart additional strength.
Unless otherwise specified above, these additional ceramic materials should be in particulate form, preferably of a size finer than 200 mesh (U.S. Standard) and more preferably finer than 325 mesh (U.S. Standard). With such characteristics, the ceramic material can be more easily sintered, during the subsequent formation of the monolith, at temperatures below those at which surface area of these materials, as well as the core metal oxides, might be adversely affected.
The phosphate component of the invention is incorporated into the monolith by admixing into the starting batch a compound capable of generating P 2 O 5 at or below the firing or sintering temperature to be used. The source of the phosphate is not critical. Phosphoric anhydride itself or phosphoric acid can be added, or a phosphate precursor, preferably one soluble in water, can be used. Preferred precursors of this kind are (NH 4 ) 2 HPO 4 (dibasic ammonium phosphate) and Al(H 2 PO 4 ) 3 (aluminum dihydrogen phosphate).
Generally, the phosphate material is added to the batch in an amount that will provide about 0.5-35% by weight of P 2 O 5 , based on the combined weights of P 2 O 5 and the core porous oxides. Preferably, the final weight of P 2 O 5 in the monolith will be about 1-25 weight percent. When substantially all of the core porous oxide is alumina, a more preferred final weight percentage of P 2 O 5 is about 1-10%, and most preferably 3-7%. When the core porous oxide is substantially all titania, a more preferred final weight percentage of P 2 O 5 is about 1.5-15%, and most preferably about 3-10%. When substantially all of the core porous oxide is zirconia, a more preferred final weight percentage of P 2 O 5 is about 1.5-15%.
The monolithic structures of this invention are prepared by admixing into a substantially homogeneous batch (a) the porous metal oxide material, (b) the phosphate-generating material, and optionally (c) a temporary binder. Preferably, 1-30% by weight of temporary binder, based on the total batch weight, is used. Any binder material conventionally used in ceramic catalyst support manufacture is suitable. Preferred are binders that are decomposed and burned-off at temperatures of about 250°-600° C. Examples are disclosed in: "Ceramic Processing Before Firing," ed/by George Y. Onoda, Jr. & L. L. Hench, John Wiley & Sons, New York; "Study of Several Groups of Organic Binders Under Low-Pressure Extrusion," C. C. Treischel & E. E. Emrich, Jour. Am. Cer. Soc. (29), pp. 129-132, 1946; "Organic (Temporary) Binders for Ceramic Systems," S. Levine, Ceramic Age, (75) No. 2, pp. 39+, January 1960; and "Temporary Organic Binders for Ceramic Systems" S. Levine, Ceramic Age, (75) No. 2, pp. 25+, February 1960. The most preferred binder is methyl cellulose, available as METHOCEL A4M from the Dow Chemical Co.
Mixing of the batch ingredients is preferably performed in a step-wise procedure in which any dry ingredients are first blended together. This preliminary dry-blending operation can be performed in any conventional mixing equipment, but the use of a Littleford intensive mixer is preferred. The dry mixture is then plasticized by being further mixed, preferably in a mix muller, with a liquid medium (preferably water) which acts as a plasticizer. During this stage, all remaining constituents are added. Up to about 1% by weight, based upon total mixture weight, of a surfactant such as sodium stearate can also be added to facilitate mixing and flow for subsequent processing. Mixing of all constituents should be continued until a homogeneous or substantially homogeneous plasticized mass is obtained.
To effect further mixing, the plasticized batch can be extruded through a "spaghetti" die one or more times. Ultimately, the batch is formed into the desired "green" shape for the monolithic structure, preferably by extrusion through a die or by injection molding. The material processing method of this invention is particularly well suited to the preparation of structures in the shape of thin-walled honeycombs and wagon-wheels. The preferred shape is that of a honeycomb having about 25-2400, more preferably 200-400, through-and-through cells per square inch of frontal surface area (equivalent to about 4-370, more preferably about 30-60, cells per square centimeter of surface area).
Finally, the "green" structures are fired in order to harden the material. The firing step generally takes place at 500°-1200° C., although the use of temperatures below about 1100° C. are preferred. For most ceramic materials, the temperature selected and the duration of the firing period will result in actual sintering of the material. This is preferred but not necessary. The strength requirements of the intended end use of the structure will determine for the skilled artisan whether the additional densification and hardening provided by fully sintering the material will be necessary. The firing/sintering step can be conducted in an inert atmosphere or in one which promotes either reduction or oxidation, depending on the presence and identity of catalytically active metal compounds in the batch, as discussed more fully below. Optionally, the firing/sintering step can be preceded by drying the shapes at about 100°-120° C., preferably by steam heat.
In the fired article, the P 2 O 5 is dispersed substantially throughout the porous metal oxide material. As those skilled in the art will recognize, however, the P 2 O 5 may not necessarily exist as a free phase but may combine with the porous metal oxide materials to form phosphate compounds or complexes. For example, AlPO 4 and 5TiO 2 .2P 2 O 5 are the common result of firing a phosphate-generating material with alumina and titania, respectively. In one particularly preferred embodiment of this invention, the final monolith consists essentially of alumina and about 4-23% by weight AlPO 4 . In another particularly preferred embodiment, the final structure consists essentially of titania and about 5-12% by weight 5TiO 2 .2P 2 O 5 . The presence of P 2 O 5 dispersed substantially throughout the ceramic metal oxide material aids its retention of high surface area despite elevated firing, sintering, or service temperatures. This benefit is illustrated in the Figures. With particular reference to FIG. 1, there is shown a graph of temperatures versus surface area retained after a 6-hour heat soak for a batch material consisting of 100% alumina and a batch material consisting of 87% by weight alumina and 13% by weight AlPO 4 . In FIG. 2 there is shown a graph of temperature versus surface area retained after a 6-hour heat soak for a batch material of 100% titania and a batch material of 92% by weight titania and 8% by weight 5TiO 2 .2P 2 O 5 . In both cases, the surface area retained after firing is shown to be greater for the phosphate-containing material than for the control.
The monolithic supports of this invention may have some catalytic activity of their own by virtue of the chemistry and structure of the high surface area phosphate-containing porous oxide phases. Nevertheless, the support structures of this invention are also intended to carry additional catalytically active ingredients on the surfaces thereof. (As used herein, the term "surfaces" refers to those surfaces of the monolithic support, including surfaces forming the pore cavities, that are normally intended to be in contact with the work stream of material to be catalyzed.) This catalytically active material can be any of the metallic catalysts heretofore used for NOx reduction, for general chemical processing, or for automotive exhaust catalysis. Preferred catalytic materials are the transition metals (including the rare earth metals) and metals of Group IIB. The metals can be used in elemental form or in the form of their oxides. Preferred metals are zinc and such transition metals as tungsten, platinum, palladium, molybdenum, iron, manganese, vanadium, and copper. These additional catalytic ingredients can be deposited on the surfaces of the monolith by methods well known in the art, such as by preparing a solution or slurry of the materials for spraying, dip-coating, or impregnating the monolithic support.
In a particularly preferred embodiment, however, the additional catalytic ingredient is admixed directly into the original batch and then co-extruded and sintered with the porous metal oxide material and phosphate material. Generally the catalytic material is incorporated into the batch in an amount of about 3-20 weight percent, preferably 5-10 weight percent, based on the total batch weight. In this embodiment, it is preferred that the admixed catalytic material be in particulate form with a primary particle size no greater than about 20 microns, preferably no greater than about 2.0 microns, and most preferably no greater than about 1.5 microns. In one embodiment of the invention, this reduced particle size is obtained by slurrying the oxide of the catalytic metal, or a precursor therefor, with distilled water, and then adjusting the pH and heating to dissolve the material. After all the material is dissolved, a portion of the ceramic oxide material to be used in the monolithic catalyst support is added to the solution. The resultant mixture is then neutralized, with a slight excess of the required acid or base, to precipitate very fine particles of the catalytic metal oxide so that they are substantially intimately admixed with particles of the porous ceramic oxide. The solids are separated by centrifugation and the resultant wet cake is then admixed with additional porous metal oxide material and phosphate material to prepare the monolith as earlier described. As a further alternative, the wet cake remaining after centrifugation can be calcined at a temperature of about 250°-300° C. The calcined material is then milled to a size finer than 100 mesh, preferably finer than 200 mesh. In this form, the material contains very fine particles (generally less than about 2.0 micron) of catalytic material intimately admixed with finely divided particles of the porous metal oxide material. The monolith is then prepared by admixing this calcined and milled material, as earlier described, with additional porous metal oxide material and phosphate material.
In another aspect of this invention, a composite monolith is provided in which a high surface area support phase, consisting essentially of the core metal oxides and 0.5-35% by weight of the phosphate material, is combined with a separate phase of ceramic material that, upon sintering, provides the actual structural integrity and strength to the monolith. In this embodiment, a pre-formed mixture of the core porous oxide material and phosphate material is coextruded with the sinterable ceramic structural material in a single step, so that the two phases are physically integrated in their green states, but the high surface area phase remains as a separate and discrete phase within the ceramic matrix after the monolith is fired. Composite monoliths of this kind, in which the high surface area support phase is a specific mixture of alumina and silica, are disclosed in U.S. Pat. No. 4,631,269 issued Dec. 23, 1986, to Lachman et al. The disclosures of this patent, which are hereby incorporated by reference, can be followed to prepare composite monoliths in which the high surface area support phase is the mixture of core porous metal oxide and phosphate material of the present invention.
The following examples are illustrative, but not limiting, of the invention.
EXAMPLE 1
Three batches of phosphate-containing alumina material (designated below as 1A, 1B, and 1C) and one control batch (100% alumina, no phosphate addition) were prepared, extruded, shaped into honeycomb monoliths, and sintered, and their properties tested. The phosphate-containing monoliths were prepared from batch ingredients as follows:
______________________________________ Composition (parts by weight)Ingredient Ex. 1A Ex. 1B Ex. 1C______________________________________Al.sub.2 O.sub.3.H.sub.2 O (CATAPAL-B, 87.4 92.06 76.94Vista Chem. Co.)Al.sub.2 (OH).sub.5 Cl (CHLORHYDROL 50%, -- -- 8.16aqueous solution,Reheis Chem. Co.)Al(H.sub.2 PO.sub.4).sub.3 solution 12.6 -- 14.9(50% in water)(NH.sub.4)2HPO4 (Baker Chem. Co.) 7.94 --METHOCEL (Dow Chem. Co.) 6.0 6.0 6.0Distilled water 38.3 40.8 35.0______________________________________
In each case, the ingredients were combined in a mix muller and the batch mixed until substantial homogeneity and plasticity were attained. The batch was extruded through a "spaghetti" die two times and then through a shaping die to form honeycomb monoliths of 1-inch (2.54 cm) diameter having 200 square cells per square inch (about 30 cells per square centimeter). The "control" material was prepared by forming a slurry of 83.5 parts by weight distilled water, 15 parts alumina monohydrate (DISPURAL, Remet Chem Corp.) and 1.5 parts acetic acid. 40 parts by weight of this slurry were then combined, in a mix muller, with a previously-made mixture of 100 parts by weight CATAPAL-B alumina monohydrate, 6 parts METHOCEL, and 16 parts distilled water. The batch was mixed and extruded to form a honeycomb as described above. In all cases, the honeycombs were fired at temperatures from 500°-1200° C. for six hours and their surface area (m 2 /g) measured by BET. For strength determination, rods of the batch material (approximately 1.3 cm in diameter) were also extruded and fired according to the same schedule, and the modulus of rupture (MOR) of the material was determined as described in U.S. Pat. No. 4,631,267. The results are shown in Table 1 below.
TABLE 1__________________________________________________________________________FiringEX. 1A EX. 1B EX. 1C ControlScheduleSA MOR SA MOR SA MOR SA(6 hours)(m.sup.2 /g) (psi) (m.sup.2 /g) (psi) (m.sup.2 /g) (psi) (m.sup.2 /g)__________________________________________________________________________ 500° C.221.9 666 226.7 1930 217.1 992 190.0 750° C.200.9 560 203.6 2060 197.5 1143 139.41000° C.125.2 903 128.3 1540 133.1 649 84.41100° C. 99.6 764 100.0 1860 94.7 716 6.11200° C. 18.3 1840 15.6 5440 14.8 2203 --__________________________________________________________________________
EXAMPLE 2
Batches of alumina material with varying amounts of phosphate material addition (designated below as Examples 2A-2F) and a control (100% alumina) were prepared by admixing the materials shown in Table 2 below and extruding the batched materials to form honeycombs. In examples 2A-2F, the indicated alumina and phosphate materials were combined in a mix muller with 6.0 parts by weight of METHOCEL and a sufficient amount of distilled water to provide plasticization. The "control" material was prepared and extruded as described in Example 1. The extruded honeycombs were then fired for 6 hours at 1000° C. and 1200° C. For each example, Table 2 provides the alumina and phosphate batch ingredients as well as the composition and BET surface area of the fired material.
TABLE 2______________________________________Batch Composition Fired Composition(parts by weight) (weight %)Example (NH.sub.4).sub.2 HPO.sub.4 Al.sub.2 O.sub.3.H.sub.2 O Al AlPO.sub.4______________________________________2A 2 98 97.5 2.52B 5 95 93.8 6.22C 8 92 89.9 10.12D 16 84 79.3 20.72E 24 76 68.3 31.72F 40 60 44.5 55.5Control 0 100 100 0______________________________________ Surface Area Surface Area (1000° C.) (1200° C.)Example (m.sup.2 /g) (m.sup.2 /g______________________________________2A 116.1 22.42B 127.0 29.22C 136.0 29.22D 129.4 16.32E 77.1 7.92F 0.6 0.3Control 86.8 6.1______________________________________
EXAMPLE 3
Batches of titania material with varying amounts of phosphate material addition (designated below as Examples 3A-I) and a control (100% titania) were prepared by admixing the materials shown in Table 3 below, according to the procedure described in Example 1. In Examples 3A-I, the indicated titania and phosphate materials were combined in a mix muller with 6.0 parts by weight of METHOCEL and a sufficient amount of distilled water to provide plasticization. The "control" material was prepared in similar fashion with the exception that no phosphate material was added to the batch. In all cases, the batched material was dried at 110° C. and then fired for 6 hours at 800° C. For each example, Table 3 provides the titania and phosphate batch ingredients as well as the composition and BET surface area of the fired material.
TABLE 3______________________________________Batch Composition Fired Composition Surface(parts by weight) (weight %) AreaExample (NH.sub.4).sub.2 HPO.sub.4 TiO.sub.2 P.sub.2 O.sub.5 TiO.sub.2 (m.sup.2 /g)______________________________________3A 60 40 44.6 55.4 3.33B 40 60 26.4 73.6 12.43C 30 70 18.7 81.3 20.53D 20 80 11.8 88.2 25.93E 10 90 5.6 94.4 34.83F 8 92 4.5 95.5 35.33G 6 94 3.3 96.7 36.63H 4 96 2.1 97.9 36.33I 2 98 1.1 98.9 30.8Control 0 100 100 0 3.0______________________________________
EXAMPLE 4
A suspension of 36 grams of zinc oxide in 1200 ml of distilled water was prepared. To this suspension was added 108 ml of concentrated hydrochloric acid. The resultant mixture was heated, with stirring, until all of the zinc oxide had dissolved. To this solution was then added 490.2 grams of titanium dioxide (Degussa Corp. P25) and the mixture was then neutralized with 108 ml of concentrated ammonium hydroxide, which caused a precipitation of the zinc oxide. The precipitated solution was centrifuged three times at 7000 rpm for 15 minutes, and the recovered solids material was transferred to an evaporating dish and heated at 110° C. until dry. The dried material was calcined for 3 hours at 300° C. and the calcined material then ball milled to a particle size finer than 100 mesh. The calcined and milled material was dry-mixed with 36 grams of METHOCEL binder and placed in a mix muller, into which was further charged a previously prepared solution of 37 grams of ammonium biphosphate dissolved in 75 ml of distilled water. Tetraisopropyl titanate, 199.8 grams, was then added to the muller, and the resulting batch was mixed in the presence of sufficient additional distilled water to plasticize the mixture. The plasticized material was extruded through a "spaghetti" die and then through a final die to form a honeycomb shape having 300 square cells per square centimeter of frontal surface area. The extruded honeycombs were dried at 60° C. for 48-72 hours and then at 110° C. for 24 hours, after which they were fired at 500° C. for 6 hours.
EXAMPLE 5
A suspension of 30 grams of ferric oxide (Fe 2 O 3 ) in 1200 ml of distilled water was prepared. To this suspension was added 600 ml of concentrated hydrochloric acid. The resultant mixture was heated, with stirring, until all of the ferric oxide had dissolved. To this solution was then added 514.8 grams of titanium dioxide (Degussa Corp. P25) and the mixture was then neutralized with 600 ml of 50% sodium hydroxide (aqueous), which caused a precipitation of the ferric oxide. The precipitated solution was centrifuged at 7000 rpm for 15 minutes. Centrifuging was repeated three times and the recovered solids material was transferred to an evaporating dish and heated at 110° C. until dry. The dried material was calcined for 3 hours at 300° C. and the calcined material then ball milled to a particle size finer than 100 mesh. The calcined and milled material was dry-mixed with 36 grams of METHOCEL binder and placed into a mix muller, into which was further charged a previously prepared solution of 37 grams ammonium biphosphate in 75 ml of distilled water. Tetraisopropyl titanate, 200 grams, was added to the muller and the resulting batch was mixed in the presence of sufficient additional distilled water to plasticize the mixture. The plasticized material was extruded through a "spaghetti" die and then through a final die to form a honeycomb shape having about 30 square cells per square centimeter of frontal surface area. The extruded honeycombs were dried at 60° C. for 48-72 hours and then at 110° C. for 24 hours, after which they were fired at 500° C. for 6 hours.
EXAMPLE 6
A suspension of 36 grams of manganese dioxide in 1200 ml of distilled water was prepared. To this suspension was added 828 ml of concentrated hydrochloric acid. The resultant mixture was heated with stirring until all of the manganese dioxide had dissolved. To this solution was then added 490.2 grams of titanium dioxide (Degussa Corp. P25) and the mixture then neutralized with 792 ml of concentrated ammonium hydroxide, which caused a precipitation of the manganese dioxide. The precipitated solution was centrifuged at 7000 rpm for 15 minutes. Centrifuging was repeated three times and the recovered solids material was transferred to an evaporating dish and heated at 110° C. until dry. The dried material was calcined for 3 hours at 300° C. and the calcined material then ball milled to a particle size finer than 100 mesh. The calcined and milled material was dry-mixed with 36 grams of METHOCEL binder and placed into a mix muller, into which was further charged a previously prepared solution of 37 grams ammonium biphosphate in 75 ml of distilled water. Tetraisopropyl titanate, 200 grams, was added to the muller and the resulting batch was mixed in the presence of sufficient additional distilled water to plasticize the mixture. The plasticized material was extruded through a "spaghetti" die and then through a final die to form a honeycomb shape having 200 square cells per square inch of frontal surface area. The extruded honeycombs were dried at 60° C. for 48-72 hours and then at 110° C. for 24 hours, after which they were fired at 500° C. for 6 hours. | A monolithic ceramic structure, useful as a support for catalytic material or as a fluid filter, has a high surface area phase which consists essentially of a porous metal oxide material, at least 50% by weight of which is alumina, titania, and/or zirconia, and phosphate dispersed substantially througout the porous metal oxide material. The presence of the phosphate stabilizes the porous metal oxide material against thermal degradation during sintering or exposure to elevated temperatures encountered in catalytic service and thereby aids in the retention of higher overall surface area in the monolithic structure. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of prior U.S. application Ser. No. 11/595,733 filed Nov. 8, 2006 now U.S. Pat. No. 7,334,567, and claimed priority to German Application No. DE 102005054737.0 filed Nov. 17, 2005, all of which are incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to a method for operating an internal combustion engine. The present invention further relates to a computer program, an electric memory medium, and a control and/or regulating device.
BACKGROUND INFORMATION
In modern internal combustion engines, in particular those having direct fuel injection, it has been attempted to positively influence the mixture preparation in the combustion chambers in order to achieve optimum conversion of the injected fuel into mechanical energy. In this connection, a comparatively high turbulence of the air charge (“charge motion”) within the combustion chamber is favorable. An increased charge motion or turbulence has a positive impact on the mixture preparation and reduces the exhaust gas emissions.
In order to adjust the motion of the air charge within the combustion chambers, a specific actuator is present in the air intake system in many internal combustion engines, which influences the flow rate of the drawn-in air or of the drawn-in air-fuel mixture by unblocking a variable cross section. Such an actuator is known as a charge motion flap, tumble valve, or swirl valve.
In some countries, it is required by law to monitor the function of the charge motion flap (tumble flap) using OBD (“onboard diagnosis”). In this connection, it is tested if an actual position of the charge motion flap corresponds to a setpoint position required by an engine controller. To this end, the charge motion flap has formerly been coupled to at least one position sensor, which reports the actual position of the charge motion flap to the engine controller. Switch contacts at the end positions of the charge motion flap or potentiometers for continuous recording are known.
An object of the present invention is to refine a method of the type described above so that the internal combustion engine may be manufactured as economically as possible.
SUMMARY OF THE INVENTION
The use of the method according to the present invention makes it possible to monitor the function of an actuator, which influences the combustion in a combustion chamber of the internal combustion engine, for example, a charge motion flap or even a spark plug, without the necessity of additional sensors. Instead, a variable characterizing the combustion in the combustion chamber is evaluated and the function of the actuator is indirectly monitored from the result of this evaluation.
Such variables characterizing the combustion in the combustion chamber are already recorded in modern internal combustion engines. To this end, pressure sensors are used, for example, which directly detect the pressure in at least one combustion chamber of the internal combustion engine. Structure-borne sound sensors or ion-current sensors may also be used to detect a variable characterizing the combustion in a combustion chamber.
The basis of the known method is a known dependence of the combustion process on the function of the actuator to be monitored. In the case of a charge motion flap, for example, the turbulence (“charge motion”) in the combustion chamber is directly a function of the position of the charge motion flap, and the combustion process is in turn a function of this turbulence. The greater this turbulence the faster is the conversion of the fuel during the combustion. Variables that are meaningful in particular for characterizing the combustion are therefore combustion characteristic, heating characteristic, and combustion duration. The heating characteristic is preferred in particular since it is comparatively simple to calculate because wall heat losses are not taken into consideration.
It is advantageous in particular if the combustion duration is determined from an energy conversion, which is calculated using a polytropic equation of state. The combustion duration may be understood, for example, as a crank angle between two percentage values (for example, 10% and 90%) of the energy conversion. The energy conversion is determined in a recording occurring in a time slot pattern of, for example, the cylinder pressure during a combustion cycle by an iterative equation of state and a continuous integration. This is possible with low computational complexity.
In a specific type of monitoring, a setpoint value for the variable characterizing the combustion is determined as a function of a setpoint operating position of the actuator and an actual operating point of the internal combustion engine and is compared to the actual value, and an action is performed as a function of the result of the comparison. The operating point of the internal combustion engine is defined, for example, by its speed, an air charge, a set rate of exhaust gas recirculation, etc.
If, for example, the combustion duration is used as a characterizing variable, an actual combustion duration is compared to a setpoint combustion duration. To this end, for example, the difference between a setpoint combustion duration and an actual combustion duration may be compared to a positive and a negative limiting value. These two values take into consideration the tolerances of the calculation of the actual value and the setpoint value. As an action, for example, information may be stored concerning a prohibited deviation of the present charge motion in the combustion chamber so that this may be remedied-during servicing, and/or this information may be displayed via suitable devices.
It is an advantage if the action is only performed if the deviation of the actual value from the setpoint value exceeds the limiting value during a specific number of working cycles in succession. This increases the reliability of the function monitoring. For determining the setpoint value, advantageously at least one characteristic map or characteristic function is used which, for example, was defined in advance on a test bench and stored for the function monitoring.
However, a determined deviation of the actual value from the setpoint value may also be used for a regulation of the actuator. In this manner, the deviation is minimized and the combustion characteristics are optimized accordingly.
An extension of the present invention provides that a changed control signal is supplied to the actuator during the operation of the internal combustion engine, and a corresponding change of a setpoint value of the variable characterizing the combustion is determined and a change of the actual value of the variable characterizing the combustion is then compared to the change of the setpoint value.
The change of the control signal is advantageously selected in such a way that no change of torque or another change of the internal combustion engine behavior noticeable to the user of the internal combustion engine occurs. If the change of the actual value is at least roughly equal to the change of the setpoint value, this means that the actuator is functional. This procedure has the advantage that function monitoring is decoupled from additional influencing variables, which may if necessary be able to influence the variable characterizing the combustion.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a schematic representation of an internal combustion engine.
FIG. 2 shows a flow chart of a method for operating the internal combustion engine of FIG. 1 .
FIG. 3 shows a diagram in which energy transformed during combustion in a combustion chamber of the internal combustion engine of FIG. 1 is plotted against a crank angle.
DETAILED DESCRIPTION
In FIG. 1 , an internal combustion engine is denoted in its entirety by reference numeral 10 . It is used to drive a motor vehicle, which is not shown, and includes an engine block 12 having a plurality of combustion chambers, of which only one in the present case is denoted by reference numeral 14 . Combustion air enters combustion chamber 14 through, among other things, a charge motion channel 16 in which a charge motion flap 18 is situated as an actuator.
Charge motion channel 16 and charge motion flap 18 are used to produce the greatest possible turbulence (“charge motion”) and thus convert the injected fuel into mechanical energy in as optimal a manner as possible. This favorably influences the fuel consumption and emissions characteristics of internal combustion engine 10 .
To this end, it is possible to change the position of charge motion flap 18 based on a corresponding control signal U_LBK. This is provided by a control and regulating device 20 . For the control and regulation of internal combustion engine 10 , control and regulating device 20 receives numerous input signals, as well as from an HFM Sensor 22 , which detects the air mass flowing to combustion chamber 14 , from which a corresponding air charge rl is determined in control and regulating device 20 .
Control and regulating device 20 also receives signals from pressure sensors, of which only one is provided with a reference numeral 24 in FIG. 1 , specifically the one which detects the pressure in combustion chamber 14 . The curve of the pressure in combustion chamber 14 and variables derived from it are used as input signals for various control and regulating functions. Additional output signals of control and regulating device 20 are, for example, activation signals for fuel metering and control of the ignition of the air-fuel mixture located in combustion chamber 14 .
For the correct operation of internal combustion engine 10 , it is important to know if charge motion flap 18 functions properly, i.e., its actual position corresponds with a setpoint position. If this is not the case, allowable limiting values for exhaust gas emissions are exceeded and control and regulating device 20 determines non-optimal control signals (for example, ignition points).
For monitoring of the correct function of charge motion flap 18 , a procedure is followed, which is stored as a computer program in a memory of control and regulating device 20 . This method will now be explained with reference to FIGS. 2 and 3 .
In 26 , it is queried whether a combustion cycle starts within a working cycle. If the answer is YES, a pressure p i is detected in 28 . The corresponding signal is provided by pressure sensor 24 . Pressure p i is detected repetitively in discrete time steps i=1 to m by incrementing a time step index i in 29 . The corresponding values p i are stored for the individual time steps i (or crank angle KW of a crankshaft of internal combustion engine 10 which is not shown in FIG. 1 ) in 30 . In 32 it is queried whether the combustion cycle has ended. If the answer is YES, an actual value BD_actual of a variable characterizing the combustion in combustion chamber 14 is determined in 34 from stored pressure values p i .
Physically, this variable represents a combustion duration, which is determined in turn from the heating characteristic. This is a thermodynamic parameter which describes the chronological sequence of the combustion. The use of the heating characteristic in the present method has the advantage that it is comparatively simple to calculate because wall heat losses are not taken into consideration. The following relation applies:
dQh=dU+p*dV (1)
where dQh is the quantity of heat supplied, dU is the increase of the internal energy of the gas, and p*dV is the delivered mechanical work. Through integration across the crank angle, the percentage share of energy conversion Qh across the crank angle is determined from variable dQh in 34 . FIG. 3 shows a typical curve of such an integral across crank angle KW. A value in ° KW between two percentage values of energy conversion Qh is understood to be combustion duration BD_actual. In the present case, as actual combustion duration BD_actual, the crank angle is understood to be between an energy conversion Qh of 10% and an energy conversion Qh of 90%.
A simple possibility for calculating the heating characteristic necessary for determining combustion duration BD_actual from pressure values p i stored in 30 is to use the following polytropic state equation:
Δ Q i = n n - 1 * p i * ( V i + 1 - V i - 1 ) + 1 n - 1 * V i * ( p i + 1 - p i - 1 ) ( 2 )
where i is the running index of cylinder pressure p i used in 28 and also stored in 30 from the start to the end of the calculation interval; n is the polytrope exponent. It should be pointed out here that the calculation interval does not necessarily have to include the entire combustion cycle. In order to save computing capacity, it is also possible to limit the calculation to the relevant portion of the combustion cycle in which the energy is liberated from the fuel. ΔQi is the energy conversion at time step i.
Energy conversion Qh over crank angle KW is now determined by summation or integration corresponding to the following formula:
Qh
m
=
∑
i
=
1
m
Δ
Q
i
(
3
)
After integration across the complete combustion cycle, i.e., the determination of the 100% value, crank angle KW is determined for 10% or 90% of the 100% value of energy conversion Qh. The difference between these two crank angles KW produces combustion duration BD_actual.
In 36 , the setpoint value for the variable characterizing the combustion is determined, i.e., a setpoint combustion duration BD_setpoint. This setpoint value BD_setpoint is based on control variable U_LBK used to actuate charge motion flap 18 . This control variable U_LBK is thus a setpoint operating position of the variable characterizing charge motion flap 18 . Furthermore, a rotational speed nmot of the crankshaft of internal combustion engine 10 , an air charge rl (based on the signal of HFM sensor 22 ) and a set rate AGR of an exhaust gas recirculation are also taken into consideration for the determination of setpoint value BD_setpoint.
Corresponding characteristic maps and characteristic functions are used for this purpose in 38 . Additional operating parameters of internal combustion engine 10 may also be used for the most exact determination possible of setpoint value BD_setpoint. For example, the data of these characteristic maps and characteristic functions have been determined in advance on a test bench for the particular internal combustion engine type for various positions of charge motion flap 18 and at the operating points of internal combustion engine 10 to be expected for monitoring.
In 40 , the difference between setpoint value BD_setpoint and actual value BD_actual is formed and it is checked if this difference is greater than a limiting value G 1 . If this is not the case, it is checked in 42 if the same difference is smaller than a second limiting value G 2 . If the answer in 40 or 42 is YES, an action is performed in 44 . This action may be that information concerning a deviation of the present charge motion in combustion chamber 14 from a desired charge motion is stored in control and regulating device 20 so that it can be retrieved in a later servicing of internal combustion engine 10 . However, the exceeding of one of the two limiting values G 1 and G 2 may also be displayed immediately. In order to avoid incorrect indications, it is provided that the display in 44 or the storage of a deviation only occurs if one of limiting values G 1 and G 2 was exceeded during a plurality of successive working cycles or combustion cycles of internal combustion engine 10 . The procedure ends in 46 .
Physically, the method shown in FIG. 2 is based on the fact that if charge motion flap 18 does not assume a desired position, the charge motion or turbulence in combustion chamber 14 is not as desired. Accordingly, the heating characteristic also deviates from a desired heating characteristic, which is determined by comparing desired combustion duration BD_setpoint with actual combustion duration BD_actual. Such a deviation is therefore an indication and if necessary also a measure of a deviation of the actual position of charge motion flap 18 from a desired position.
However, actual value BD_actual and setpoint value BD_setpoint may also be used in 48 for regulating charge motion flap 18 . This means that the deviation between setpoint value BD_setpoint and actual value BD_actual is regulated.
In an exemplary embodiment which is not shown, charge motion flap 18 is actuated in such a way that no change of the torque of internal combustion engine 10 or similar changes in the behavior of internal combustion engine 10 are noticeable to its user. If, however, the expected change of actual value BD_actual occurs, charge motion flap 18 is functional. This version of the method has the advantage that specific influencing variables that also influence the combustion duration and accordingly actual value BD_actual are decoupled from the function test of charge motion flap 18 . | An internal combustion engine includes a charge motion flap which influences the combustion in at least one combustion chamber of the internal combustion engine. The function of the charge motion flap is monitored. At least one actual value of a variable characterizing the combustion in the combustion chamber is evaluated and the evaluation result is used for function monitoring of the charge motion flap. | 5 |
CROSS REFERENCES TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Patent Application No. 60/072,742, filed Jan. 27, 1998, the disclosure of which is incorporated by reference herein.
STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT
BACKGROUND OF THE INVENTION
The present invention relates to coating applicators in general and to apparatus for applying coatings to moving substrates in particular.
Paper of specialized performance characteristics may be created by applying a thin layer of coating material to one or both sides of the paper. One type of coating fluid is a mixture of a fine plate-like mineral, typically clay or particulate calcium carbonate; coloring agents, typically titanium dioxide for a white sheet; and a binder which may be of the organic type or of a synthetic composition. Another type of fluid is a starch and water solution used in sizing applications. Coated paper is typically used in magazines, commercial catalogs and advertising inserts in newspapers. The coated paper may be formed with a smooth bright surface which improves the readability of the text and the quality of photographic reproductions. Coated papers are divided into a number of grades. The higher value grades, the so-called coated free-sheet, are formed of paper fibers wherein the lignin has been removed by digestion. Less expensive grades of coated paper contain ten percent or more ground-wood pulp which is less expensive than pulp formed by digestion.
Coated papers are often used for high-quality printing or in other applications where visible variations in coating weight would significantly detract from the appearance of the paper. It is therefore of key concern to maintain coating thickness consistency across the width of the treated web. Greater efficiency and cost control in papermaking has driven the construction of ever wider papermaking machines, sometimes of 300-400 inches or more. In conventional fountain applicators, a single supply chamber extends the full width of the web in the cross machine direction. This supply chamber may be fed from one or both ends. To minimize fall off of coating ejected from a nozzle which terminates the supply chamber, coating is supplied at a high pressure. Nevertheless, such coaters are prone to heavier coating application at the ends.
Furthermore, the heated coatings which are frequently employed can, over the extended cross machine width of the coater head, result in temperature gradients which cause bowing of the head with resultant coat weight variations.
What is needed is a papermaking fountain applicator which may be operated at lower pressures while still supplying consistent coating levels to the substrate in the cross machine direction.
SUMMARY OF THE INVENTION
The coating applicator of this invention has two coating supply tubes which extend parallel to one another and run the full width of the substrate in the cross machine direction. Coating is supplied separately to each supply tube from opposite ends. The supply tubes discharge coating through spaced metering holes into an application chamber defined between a sidewall mounted to each supply tube. The counterflow arrangement of the coating supply tubes results in the fall off of coating pressure in one tube being canceled out by the increased pressure in the other tube at any particular point moving across the coater head in the cross machine direction. The tendency of the pressure to fall as the coating moves through the supply tube may be further counteracted by varying the spacing between metering holes with cross machine position, by varying the diameter of the metering holes, or both.
The tendency of the heated coating to cause a temperature gradient in the applicator head may be counteracted by cantilevering the applicator head on arms from a support beam through which a temperature-controlling fluid is circulated.
It is a feature of the present invention to provide a coating applicator which supplies a coating to a jet applicator nozzle at a constant pressure.
It is another feature of the present invention to provide a coating applicator which is conveniently profile controlled.
It is an additional feature of the present invention to provide a papermaking coating applicator which is less susceptible to bowing due to temperature gradients.
It is also a feature of the present invention to provide a papermaking coating applicator which operates at reduced coating pressures.
Further objects, features and advantages of the invention will be apparent from the following detailed description when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view of the coating applicator of this invention on a papermaking machine.
FIG. 2 is a perspective view, partially broken away in section, of the papermaking machine applicator of the apparatus of FIG. 1 .
FIG. 3 is a side elevational view of an alternative embodiment coating applicator of this invention having an offset support beam with temperature maintenance.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring more particularly to FIGS. 1-3, wherein like numbers refer to similar parts, the coating applicator 20 of this invention is shown in FIGS. 1 and 2. The applicator 20 has two elements which control the quantity and thickness of coating 22 applied to a moving substrate, for example a paper web 24 supported by a backing roll 26 . These two elements are the applicator head 28 and the metering blade assembly 30 . Coating 22 is supplied under pressure to the applicator head 28 and ejected from an applicator head nozzle 32 on to the moving web 24 . The metering blade 34 of the assembly 30 engages the coated web downstream of the applicator head 28 and removes excess coating 22 . Applied coating which is not retained on the web is collected in a coating pan 36 and recirculated.
As shown in FIG. 2, the applicator head 28 has two segments 38 which are pivotably connected. The machine direction is defined as the direction of movement of the web 24 . The cross machine direction is the direction parallel to the axis of the backing roll 26 . A first coating supply tube 40 is affixed to a first bracket assembly 42 which has a series of aligned ears 44 which are rotatably mounted on brass bushings to a second bracket assembly 46 which is bolted to a rectangular support beam 52 which extends the length of the applicator head in the cross machine direction. A second coating supply tube 48 is fixed to the second bracket assembly 46 . The second coating supply tube 48 extends parallel to the first coating supply tube 40 . The support beam 52 is a rigid rectangular section member which may be as tall or taller than the coating applicator itself. The support beam 52 and the applicator mounted thereon will preferably be supported on pivoting arms, not shown, which allow the applicator to be withdrawn from the backing roll during start up or in the case of a sheet break.
An inflatable air tube 50 is positioned between the support beam 52 and a lower plate 54 of the first bracket assembly 42 . The first coating supply tube 40 has a plurality of metering holes 58 positioned above a first chamber floor segment 56 . The second coating supply tube 48 has a plurality of metering holes 58 positioned above a second chamber floor segment 60 . In the operational configuration, the air tube 50 is inflated to bring the coating supply tubes together such that the first chamber floor segment 56 engages the second chamber floor segment 60 . A liquid tight seal is formed between the adjacent chamber floor segments by a resilient gasket such as a cylindrical neoprene tube 62 which is received within a groove 64 defined along the center of the second chamber floor segment 60 .
A nozzle chamber 66 is defined between a first wall 68 which extends upwardly from the first coating supply tube 40 and a second wall 70 which extends upwardly from the second coating supply tube 48 . The first wall 68 and the second wall 70 converge to define a cross machine gap 72 through which coating is ejected from the nozzle 32 . To provide for ready replacement of the terminal segments of the first wall and second wall, the first wall preferably includes a replaceable first terminal segment 74 attached to a lower portion 76 of the first wall 68 ; and the second wall includes a replaceable second terminal segment 78 attached to a lower portion 80 of the second wall 70 .
To promote the uniformity of the jet of coating exiting from the nozzle gap 72 , coating 22 is supplied to the nozzle chamber 66 through both the first coating supply tube 40 and the second coating supply tube 48 . The first coating supply tube 40 has an inlet end 82 through which coating under pressure is introduced. The second coating supply tube 48 has an inlet end 84 which is spaced from the first coating supply tube inlet end 82 in the cross machine direction. The two coating supply tube inlet ends 82 , 84 are spaced on opposite sides of the applicator head 28 . Hence, the coating in one of the coating supply tubes flows in a direction counter to the direction of flow in the other coating supply tube. The end of each coating supply tube opposite its inlet end will preferably have a smaller outlet through which 10-20 percent of the coating leaves the coating supply tube to be recirculated. The coating supply tubes provide a means for introducing coating to the nozzle chamber in opposite but parallel directions.
When the high viscosity coating 22 is supplied to the nozzle chamber 66 through one of the coating supply tubes, there will be a pressure drop from the inlet end to the outlet end. This drop in pressure will tend to result in reduced flow velocity of the coating through the metering holes 58 adjacent the outlet end of a coating supply tube. However, because the outlet end of one coating supply tube discharges coating into the nozzle chamber adjacent the inlet end of the other coating supply tube, where the pressure is higher, the effect of the pressure drop is canceled out. Thus the falling pressure moving in the cross machine direction along one coating supply tube coincides with the rising pressure in the opposed coating supply tube moving in the same direction. The result of this arrangement is to equalize the pressure along the entire cross machine direction width of the applicator head 28 . In coating supply tubes with equally spaced metering holes 58 , the metering holes along one tube may be spaced apart approximately 0.5 to 4.2 inches in the cross machine direction, in a preferred embodiment the holes may be spaced from about 1.4 inches to 2.8 inches. The holes in the first coating supply tube are staggered from the holes in the second supply tube, such that a hole in one coating supply tube discharges coating into the chamber across from a land in the opposite coating supply tube.
This effect may be emphasized by adjusting the spacing between metering holes or the diameter of the metering holes. Generally, in the center region of each tube, the spacing of the holes, the diameter of the holes, or both would remain constant, with increased spacing, decreased diameter or both toward the ends of the tubes. Generally, the variation in hole diameter or spacing will occur about one meter from the end. For example, the metering holes may be spaced approximately 1.4-2.8 inches apart at the center of a coating supply tube, with the spacing being gradually increased until adjacent metering holes are approximately 2.8 to 4.2 inches apart at an end. As an alternative to varying the spacing between holes, the diameter of the holes could be varied plus or minus 50 percent. This variation would take place over the typically 400 in. width of the coating applicator 20 . As an example, the nominal diameter of the holes might be about ⅜ of an inch, with a variation of plus or minus 50 percent. The coating supply tubes may be about four inches in diameter, with a range of supply tube diameter of from about 2½ inches to 10 inches. It should be noted that although cylindrical coating supply tubes are illustrated, tubes of other profile may be employed.
As shown in FIG. 1, the coating applicator 20 is provided with profiling capability by a series of threaded adjustment rods 86 which extend from a profiling bar 88 which is bolted to the first bracket assembly 42 to a series of corresponding threaded holes in the terminal segment 74 on the first nozzle wall 68 . By adjusting the rods 86 , the width of the gap 72 in the machine direction may be controlled as it extends in the cross machine direction. The terminal segment 74 preferably narrows or necks down below the location of attachment of the adjustment rods 86 , facilitating the bending of the upper portion of the terminal segment. As shown in FIG. 2, the adjustment rods 86 in a preferred embodiment may be spaced approximately eight inches apart, but the spacing may range from two to sixteen inches.
As shown in FIG. 1, a sheet metal cover 90 extends over the adjustment rods 86 , being received within a groove in the first terminal segment 74 and being screwed to the profiling bar 88 . Another sheet metal cover 92 extends from the second terminal segment 78 and into the coating pan 36 . Another cover 94 descends from the metering blade assembly 30 to direct coating into the coating pan 36 .
An alternative embodiment applicator head assembly 96 is shown in FIG. 3 . The assembly 96 thermally isolates the applicator head 98 from the support beam 100 , by cantilevering the applicator head from the support beam on a series of support arms 102 , each spaced from one another in the cross machine direction approximately two feet apart. The applicator head 98 has a first coating supply tube 104 which is pivotably connected to the support arms 102 . The first coating supply tube 104 is also pivotably connected to the bracket 106 . A second coating supply tube 108 is fixed to the bracket 106 . To adjust the angle of the applicator head 98 with respect to the support beam 100 , a screw jack 110 extends between the support beam 100 and the bracket 106 .
As in the applicator 20 , coating is supplied to the first coating supply tube 104 at an inlet end 112 from a pressurized coating supply. Coating is simultaneously supplied to the second supply tube at an opposite end. The coating travels through the coating supply tube and enters the applicator nozzle 114 . A fraction of the coating is recirculated through a recirculation outlet 116 . Often coating fluid temperatures are other than the ambient temperature. On applicator heads in which the main support beam is an integral part of the applicator head, the introduction of warm coating into the applicator head can create a thermal gradient between the heated portions of the applicator head and the unheated support beam.
The applicator 96 counters this thermal gradient effect by thermally isolating the support beam 100 from the portions of the applicator head through which the heated coating flows. In addition, temperature compensating fluid, preferably water 118 , is pumped through the support beam 100 to keep the support beam within a limited range of temperature and to thereby prevent temperature-gradient-induced bowing of the support beam. In a preferred embodiment, water would be maintained at the desired temperature range within a rig, not shown, and pumped into four corner chambers 120 defined by rectangular plates 122 running the entire cross machine direction length of the support beam and welded in place. Although the key requirement of the temperature compensating water 118 is that its temperature be maintained within a desired range, the water may be maintained at a level slightly above freezing, for example 40 degrees Fahrenheit. Where required by temperature gradients present in the system, temperature compensating water at different temperatures and/or flow may be introduced into one or more of each of the four corner chambers. This variation may extend so far as to discontinue flow through one or more of the chambers. With this control, it is possible to control the position of the beam.
The chilled water would tend to cause the metal support beam 100 to condense water vapor from the surrounding air. This “sweating” of the support beam would have the advantageous effect of preventing coating build-up on the support beam. The coating pan 134 is preferably connected directly to the support beam 100 . The temperature compensating water 118 is recirculated to the temperature maintaining rig after having passed through the support beam.
The applicator 96 also has an alternative profiling structure, in which an array of screws 124 extend between a terminal wedge 126 and a protrusion 128 extending from a lower portion 130 of the chamber wall 132 connected to the first coating supply tube 104 . The terminal wedge 126 extends from the lower portion 130 of the chamber wall on a narrow segment of material, permitting it to be urged toward the second wall 132 of the chamber to control the variation of the coating jet in the cross machine direction.
It should be noted that although the substrate has been illustrated as a paper web supported by a backing roll, the substrate may alternatively be a roll itself, which receives the coating for downstream application to a paper web, for example as in a size press. It should be noted that where coating or coating material is referred to herein, pigmented coatings, sizing solutions, and other fluids which may be applied to a paper web are included. The coating applicator of this invention may also be used in off-machine applications as well as on-machine.
It is understood that the invention is not limited to the particular construction and arrangement of parts herein illustrated and described, but embraces such modified forms thereof as come within the scope of the following claims. | Two coating supply tubes extend parallel to one another and run the full width of a moving substrate in the cross machine direction. Coating is supplied separately to each supply tube from opposite ends. The supply tubes discharge coating through spaced metering holes into an application chamber defined between a sidewall mounted to each supply tube. The counterflow arrangement of the coating supply tubes results in the fall off of coating pressure in one tube being canceled out by the increased pressure in the other tube. The fall off may be further counteracted by varying the spacing between metering holes the greater the distance from the coating inlet, by varying the diameter of the metering holes, or both. The tendency of the heated coating to cause a temperature gradient may be counteracted by cantilevering the applicator head on arms from a support beam through which a temperature-controlling fluid is circulated. | 3 |
This invention relates generally to hydro-elastic engine mounts for applications such as motor vehicles and more specifically to various devices for coupling and decoupling the vibration damping characteristics of the mount in response to changes in driving and engine operating conditions.
BACKGROUND OF THE INVENTION
Various devices have been designed in the past to provide means of partially or fully decoupling and coupling the vibration damping characteristics of hydraulic mounts for engines for motor vehicles in response to changes in driving and engine operating characteristics. Because damping forces add to spring forces to create a high dynamic rate (force/deflection); it is desirable to eliminate the damping when it is not needed. Therefore, most hydro-elastic mount designs include devices that de-activate or "decouple" the damping for relatively small amplitude flexing.
A typical engine mount contains two sealed chambers separated by an intermediate partition having a damping channel passing therethrough and providing communication between the chambers. The engine mount normally has one end member attached to an engine block and another end member attached to a vehicle frame, with the end members being resiliently connected to each other by an elastomeric member which permits one end member to move in response to vibrations with respect to the other. In order to damp vibrations between the two end members, hydraulic fluid is pumped back and forth from one chamber to the other through the damping channel in the partition. In order decouple the damping action, it is necessary to prevent the hydraulic fluid from flowing back and forth through the channel by providing another alternative response to vibrations which would normally tend to pump the hydraulic fluid through the damping channel.
One type of device for adjusting damping in an engine mount is the use of an inflatable bladder mounted inside the primary fluid chamber as shown in U.S. Pat. Nos. 4,840,358 and 4,901,986.
Another approach to the problem is shown in U.S. Pat. No. 4,886,251 in which an inflatable diaphragm inside the pressure chamber forms an air chamber with the end member and an elastomeric spring member. When air pressure is inserted into the air chamber, the diaphragm is lifted off the spring member and bears against the annular partition wall and prevents any vibration from being transmitted from the elastomeric spring member to the damping fluid in the pressure chamber. This causes decoupling of any damping which would otherwise occur if the air chamber were not inflated.
U.S. Pat. No. 4,886,252 shows decoupling of the damping action of the engine mount by changing the wall area or volume of the damping channel.
U.S. Pat. No. 4,712,777 shows another decoupling device which uses an air chamber covered by a diaphragm adjacent to the fluid pressure chamber of the engine mount. The diaphragm contains a shutter panel which can be closed to isolate the diaphragm from the pressure chamber. When the diaphragm is isolated from the pressure chamber, fluid is pumped through the damping channel by vibration imparted to the fluid. When the shutter panel lifts off a seated position and exposes the diaphragm to communication with the pressure chamber, then deflection of the diaphragm will occur in response to vibrations imparted to the fluid, and such deflection will result in either partial or complete decoupling of the damping action by reducing or preventing fluid from flowing through the damping channel. The present invention is intended to provide certain advantages over the prior art decoupling devices as will be described in the following specification.
OBJECTS OF THE INVENTION
It is a primary object of this invention to provide a simple and effective device for decoupling vibration damping in a vehicle engine mount, which device is easy to manufacture, install and maintain.
Another object of this invention is to provide a decoupler for vibration damping in an engine mount, which is versatile and has a wide range of control options for varying the amount of decoupling, depending upon the driving conditions and engine performance.
Still another object of this invention is to provide a vibration damping decoupler which can alternately adjust the engine mount condition to firm, soft or intermediate.
These and other objects of the invention will become more fully apparent in the following specification and the attached drawings.
SUMMARY OF THE INVENTION
This invention is a hydro-elastic engine mount for mounting an engine on a vehicle frame the mount comprising: a first end member, a second end member spaced in an axial direction from the first end member, an annular elastomeric spring element sealingly attached to the first end member, an annular sidewall extending between the elastomeric spring element and the second end member to form an enclosed chamber between the first and second end members, a partition inside the enclosed chamber dividing it into a main fluid chamber and an auxiliary fluid chamber, said partition containing a damping channel therethrough which permits fluid to flow back and forth between the main fluid chamber and the auxiliary fluid chamber when certain vibration conditions occur to provide relative vibration damping between the first and second end members, and a coupling/decoupling means mounted inside the main fluid chamber to alternately couple and at least partially decouple the vibration damping action of the fluid flow through the damping channel said coupling/decoupling means comprising: a rigid body member having a concave wall forming a cavity with an open side facing on the inside of the main fluid chamber, a flexible extensible elastomeric diaphragm sealingly attached to the rigid body member and covering the open side of the cavity at a spaced distance from the concave wall of the body member, said diaphragm being deflectable into the cavity a distance relative to the pressure differential between the fluid pressure in the main fluid chamber and the air pressure in the cavity, the body member having a port extending through the concave wall thereof and in communication with the exterior of the engine mount to permit the flow of air in and out of the cavity, and means to control the flow of air through the port in and out of the cavity to effect pressure changes within the cavity and thereby change the amount of deflection of the diaphragm.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of one embodiment of the invention with portions broken away to show the interior construction of the device of the invention;
FIG. 2 is an enlarged fragmentary view of an annular ring type decoupling device in another embodiment of the invention;
FIG. 3 is a greatly enlarged fragmentary view of an annular ring type decoupler with a diaphragm of the decoupler being drawn into an annular cavity;
FIG. 4 is a cross-sectional view of another embodiment of the invention showing a disk shaped decoupler;
FIG. 5 is a side elevational view of another embodiment of the invention with portions broken away to show a disk shaped decoupler located in two different alternative positions.
FIG. 6 is a test data graph showing a comparison of the performance of a decoupler used in three different operating modes including a vacuum, a check valve and an open port;
FIG. 7 is another test data graph showing a comparison of the dynamic rates of a decoupler in four different modes including an open port, a closed port and two different amounts of vacuum;
FIG. 8 is another test data graph showing a comparison of the damping loss angle of the same modes shown in FIG. 7;
FIG. 9 is another test data graph showing a comparison of the dynamic rates of a decoupler in the modes of either a closed orifice, three different orifice sizes; and
FIG. 10 is still another test data graph showing a comparison of the loss angle of the same modes shown in FIG. 9.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings and in particular to FIG. 1, a hydro-elastic engine mount is indicated generally by the numeral 10. The mount 10 has an end member 12 which includes a vented metal cap 14, from which projects a centrally located threaded stud 16 for attachment to an engine block (not shown).
The mount 10 also has an opposite end member 18 which has an annular collar member 20 with a threaded stud 22 extending outwardly therefrom, for attachment to a vehicle frame (not shown). A flanged cup member 24 is attached to the inner end of the stud 22. The cup member 24 has a radially outwardly extending flange 26 on which is carried an annular elastomeric bumper ring 28.
An annular elastomeric spring element 30 surrounds and is adhered to the outer circumference of the collar member 20. The spring element 30 is also adhered at its outer circumference to one end of a substantially cylindrical shaped can member 32 which has its opposite end bent inwardly to engage a lower flanged edge 34 on the cap 14. The end members 12 and 18, the spring 30 and the can member 32 form an enclosed container. A disk shaped partition member 36 inside the can member 32 divides the interior of the container of the engine mount 10 into two chambers; one being a working fluid chamber or pressure chamber 38 and the other an auxiliary or compensating chamber 40.
Since the cap 14 is vented it is necessary to clamp the peripheral edge of a flexible disk shaped diaphragm 42 between the partition 36 and the lower edge of the cap 14 so that hydraulic fluid can be contained within the auxiliary chamber 40 without running out through any vent holes in the cap 14.
The partition 36 contains an annular damping channel 44 which has one end in communication with the pressure chamber 38 and the other end in communication with the auxiliary chamber 40 so that hydraulic fluid can flow back and forth between the chambers 38 and 40 to provide vibration damping as will be explained later.
An annular decoupler unit indicated generally by the numeral 46 is mounted inside the can 32 between the partition 36 and a flange of a stop ring 48. The stop ring 48 has a radially inwardly extending flange which engages the bumper ring 28 to limit the distance of travel of the end member 18 and prevent excess flexing of the spring 30 due to large engine movements.
The decoupler unit 46 has an annular rigid ring member 52 having a radially inwardly facing annular concave cavity 54. The cavity 54 is covered by a flexible extensible elastomeric diaphragm 56 clamped in retaining grooves on each side of the cavity 54. The diaphragm 56 forms an airtight seal with the ring 52 except for an inlet/outlet port 58 which is connected to a tube 60 extending through the wall of the can member 32 and connected to a solenoid valve 62.
The solenoid valve 62 is in turn connected through a tube 64 to another solenoid valve 66. The solenoid valve 62 is presently shown in position to provide open communication between the cavity 54 and the solenoid valve 66 which is presently shown as vented to the outside atmosphere through a large orifice 68.
The solenoid valve 62 also has an off position and a position where the cavity 54 is put in communication with a tube 70 leading to a check valve 72. The solenoid valve 66 also has an off position and a position where the tube 64 is put in communication with a small or restricted orifice 74. The small orifice 74 is sized to provide an optimum level of damping for a specific engine/body/driving condition combination. The amount of damping obtained varies inversely with the size of the orifice.
In operation, when the engine mount 10 is mounted on a vehicle (not shown), the interior of the mount 10 is filled with a sufficient amount of liquid so that when vibration occurs and is imparted through the spring member 30 and the end member 18, liquid can be pumped back and forth between the pressure chamber 38 and the auxiliary chamber 40 through the damping channel 44, thereby providing damping of the vibration. In order to have full damping, the decoupler must be disengaged. To accomplish this, the solenoid valve 62 is moved to the position where the cavity 54 is in communication with the check valve 72. As the vibration deflects the diaphragm 56 inwardly into the cavity 54, air is ejected through the check valve 72 but cannot return to the cavity 54. As a result of the vibration, the air is rapidly pumped out of the cavity until the diaphragm 56 is drawn completely against the concave wall of the cavity 54, as shown in FIG. 3. This creates the same effect as though there, was no decoupler and full damping continues until there is a change in the position of the solenoid valves.
To provide partial decoupling, the solenoid 62 is moved to the position shown in FIG. 1, however solenoid 66 is moved to the position where the tube 64 is in communication with the small or restricted orifice 74. In this intermediate position, there is about 1/3 to 1/2 of full damping. When both solenoid valves are in the position shown in FIG. 1, the damping is almost fully decoupled and very little damping is occurring. In this valve position, the diaphragm 56 can deflect freely in and out of the cavity 54 to decrease the fluid pressure peaks sufficiently that vibrations acting on the fluid will not cause the fluid to flow through the damping channel.
While in FIG. 1 the solenoid valves 62 and 66 are shown connected in a series it should also be recognized that they can be connected in parallel or can be connected individually or only one or the other of the two valves need be connected to the cavity 54.
FIG. 2 shows another embodiment of the invention using a solenoid valve 76 having one port 78 open for full venting and another port 80 connected to vacuum to withdraw air from the cavity 54 and draw the diaphragm 56 down against the wall of the cavity 54 as shown in FIG. 3. This performs the same function as the use of the one-way check valve 72 in FIG. 1. When the diaphragm is fully drawn into the cavity 54, the full damping is in effect. When the solenoid is moved to the position where the cavity 54 is in communication with open port 78, there is full venting to the atmosphere and the damping is fully decoupled. Since all the parts of the device shown in FIG. 2 except the solenoid valve 76 are identical to those shown in FIG. 1 the same numerals will be used to identify similar parts and they will not be described separately in the specification.
While the decoupler 46 has been shown as being of annular configuration in FIGS. 1 through 3, It will also be recognized that a similar effect could be obtained from a disk shaped member such as the decoupler 82 shown in FIG. 4. The decoupler 82 is comprised of a rigid circular body member 84 having a centrally located cavity 86 therein. A circular diaphragm 88 extends across the cavity 86 and has an annular rib 90 which engages an annular groove 92 to hold the diaphragm 88 firmly at the edges when a clamp ring 94 is screwed onto the body member 84. An inlet/outlet tube 96 extends from the cavity 86 for connection to a solenoid valve as will be explained later in the description of FIG. 5.
FIG. 5 shows an engine mount 10a which is identical to the mount in FIG. 1 except that instead of using the annular decoupler 46 it uses the disk shaped decoupler 82 shown in FIG. 4. For simplicity, since all parts except the decoupler are identical to those of FIG. 1, the identical parts will be identified with the same numerals as the parts in FIG. 1 and the identical parts will not be described again in detail.
FIG. 5 is presented merely to show two different possible locations where the disk shaped decoupler 82 may be mounted within the pressure chamber 38 as an alternative to using the annular decoupler 46.
As shown in solid lines, the decoupler 82 may be mounted on the partition 36 with the cavity 86 facing into the pressure chamber 38. An inlet/outlet tube 96 connects the cavity 86 to the solenoid valve 62 and through the tube 64 to the solenoid valve 66. The diaphragm 88 deflects into the cavity 86 (as shown in ghost lines in FIG. 4) in the same manner as the diaphragm 56 and functions in the same manner with respect to the solenoid valves 62 and 63 as was previously described regarding the annular decoupler 46.
Likewise the decoupler 82 may be mounted on the flanged cup member 24 on the bottom end member 18 as indicated by ghost lines and identified as 82a. The inlet/outlet tube 96a can extend out through the bottom member 18.
The test data graphs shown in FIGS. 6 through 10 show a comparison of the performance of the decoupler of the invention in different modes depending upon whether a cavity of the decoupler is connected to a certain amount of vacuum, or to a check valve, or is sealed by a closed solenoid valve, or is open to one of several different size vent orifices which are open to the atmosphere.
It may be seen from the graphs in FIGS. 6 through 10 that when either the cavity 54 of the decoupler 46 or the cavity 86 of the decoupler 82 is fully vented through an open port or a large orifice to the atmosphere so that the air can move freely in and out and the diaphragm can easily flex inwardly, this mode decouples the damping effect of the device and little or no damping occurs. When a diaphragm such as the diaphram 56 shown in FIG. 3 is drawn down into the cavity 54 so that it is no longer free to flex, then damping occurs due to the movement of liquid through the damping channel 44. Connection of the cavity 54 to a vacuum or to a check valve will result in the air being drawn from the cavity, thereby drawing the diaphragm into the cavity. The graphs in FIGS. 9 and 10 illustrate that when the cavity of the decoupler is connected to orifices of varying size, the least damping will occur when using large orifices and the most damping will occur when using small orifices.
Thus, it can be seen that any operating mode which permits increased flexing of the diaphragm will reduce the amount of damping and any mode which reduces the flexing of the diaphragm will increase the amount of damping.
It should be understood that various combinations of valves can be used, however, using a combination of valves such as that shown in FIGS. 1 and 5 will give versatility in the range of control over the amount of decoupling by providing several options for effecting the control of damping.
These and various other modifications can be made in the embodiments shown herein without departing from the scope of the invention. | An engine mount for motor vehicles having two enclosed chambers containing hydraulic fluid, which chambers are separated from each other by a partition containing a damping channel passing therethrough to permit hydraulic fluid to flow back and forth between the chambers to damp vibrations imparted to the mount. The engine mount is equipped with a decoupling unit within one of the hydraulic chambers for coupling and decoupling the damping action of the mount in response to varying driving conditions and engine performance. The decoupling unit has a rigid member forming a cavity into which a flexible diaphragm is deflected when vibrations occur when the decoupling unit is set in a decoupling mode to prevent fluid from being pumped back and forth through the damping channel. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a bush assembly, to a method of manufacturing such a bush assembly and to a bush for use in such an assembly. It is particularly, but not exclusively, concerned with a bush assembly for use in a sub frame of an automobile.
2. Summary of the Prior Art
One known bush for use in a automobile between the chambers and the sub frame has an outer sleeve and a tube in the sleeve, the sleeve and the tube being interconnected by a resilient body. The sleeve is then mounted in a housing such as a bracket. Then the bracket may be attached to, or embedded in, the sub frame and the tube attached to the chassis, or vice versa. Thus active movement of the sleeve and the tube, and hence the chassis and the relevant part of the sub frame, are resisted by the resilience of the resilient body.
In such a bush assembly, the stiffness of the assembly, and hence its effect on vibrations is determined by the resilient body. However, it is been found desirable to have different radial stiffnesses in different directions.
SUMMARY OF THE INVENTION
At its most general, the present invention proposes that at least one projection be provided on the sleeve, which projection(s) will abut the wall of the bore of the housing into which the sleeve is inserted, thereby locally deforming the sleeve.
Thus, at the location of the projection(s) the gap between the sleeve and the tube is reduced as compared with other radial positions. This locally compresses the resilient body, permitting the desired radial stiffness characteristics to be achieved.
In the present invention, the deformation of the sleeve due to the presence of the projection(s) is achieved when the sleeve is inserted in the housing, rather than being achieved by the initial shaping of the sleeve.
It would be more difficult to pre-mould the sleeve to that shape, or to provide an additional component between the sleeve and the tube to achieve the same effect.
Thus, a first aspect of the present invention may provide a bush assembly comprising:
a sleeve formed of a deformable nylon material and having an outer surface that has an outer diameter that is formed with at least one projection;
a tube within the sleeve, there being a gap between the sleeve and the tube;
a resilient body formed of a rubber material interconnecting the tube and the sleeve; and
a housing having a bore with an inner diameter into which the sleeve is received, the at least one projection abutting the wall of the bore;
wherein the sleeve outer diameter is of a size to provide a good grip between the sleeve and the housing bore and further is adapted to locally deform radially inwardly adjacent the projection when the sleeve is mounted within the bore such that the radial width of the gap between the sleeve and the tube radially inward of the projection is less than at least one other circumferential point of the tube.
The sleeve needs to be of a material suitable to be deformed under the effect of the interaction of the projection and the wall of the bore of the housing.
Preferably, the sleeve is therefore of nylon or other plastics material which may provide sufficient rigidity to maintain the resilient body in place, but be sufficiently deformable for the effects of the present invention to be achieved.
To improve the deformability, the thickness of the sleeve in the radial direction may be reduced adjacent to the position of the projection, e.g. by providing a groove in the outer surface of the sleeve.
It should also be noted that, prior to insertion of the bush into the housing, the diameter of the sleeve will be slightly greater than the diameter of the bore, to provide an overall compressor effect which is desirable to eliminate and stresses in the resilient body, and also to provide good grip between the sleeve and the housing.
The projections then provide an additional reduction in diameter at their radial positions.
Preferably, two projections are provided at opposite ends of a diameter, and those projections may then be at a mid point of the sleeve, in the axial direction of the sleeve.
Moreover, whilst it would be usual for the projections to have the same height, it is not essential and they may be different to give different stiffness effects on opposite sides of the bush.
According to a second aspect of the present invention there may be provided a method of manufacturing a bush assembly, comprising inserting a bush into a bore in a housing, the bush comprising:
a sleeve formed of a deformable nylon material and having an outer surface that has an outer diameter that is formed with at least one projection;
a tube within the sleeve, there being a gap between the sleeve and the tube;
a resilient body formed of a rubber material interconnecting the tube and the sleeve; and
a housing having a bore with an inner diameter into which the sleeve is received, the at least one projection abutting the wall of the bore;
wherein the sleeve outer diameter is of a size to provide a good grip between the sleeve and the housing bore and further is adapted to locally deform radially inwardly adjacent the projection such that the radial width of the gap between the sleeve and the tube radially inward of the projection is less than at least one other circumferential point of the tube.
According to a third aspect of the present invention there may be provided a bush comprising:
a sleeve formed of a deformable nylon material and having an outer surface that has an outer diameter and that is formed with at least one projection;
a tube within the sleeve, there being a gap between the sleeve and the tube;
a resilient body formed of a rubber material interconnecting the tube and the sleeve; wherein radial depression of at least one projection relative to the rest of the sleeve causes local deformation of the sleeve such that the radial width of the gap between the sleeve and the tube radially inward of the projection is less than at least one other circumferential point of the tube.
BRIEF DESCRIPTION OF THE DRAWINGS
An embodiment of the present invention will now be described in detail by way of example, with reference to the accompanying drawings in which:
FIGS. 1 a and 1 b are transverse and axial sectional views through a bush for use in an embodiment of the present invention, FIG. 1 b being taken along the line B to B in FIG. 1 a;
FIG. 2 is a perspective view of the sleeve of the bush of FIGS. 1 a and 1 b;
FIG. 3 is a perspective view of the bush shown in FIGS. 1 a and 1 b;
FIGS. 4 a and 4 b are transverse and axial sectional views through a bush assembly being an embodiment of the present invention, and incorporating the bush of FIGS. 1 a and 1 b.
DETAILED DESCRIPTION
An embodiment of the present invention, being a sub frame bush assembly for use in an automobile, will now be described.
The assembly comprises a bush which is mounted in a housing, and FIGS. 1 a and 1 b show the bush prior to its mounting in the housing, the bush comprises an outer sleeve 10 and an inner tube 12 connected by a resilient body 14 . In the axial sectional of view of FIG. 1 b , the resilient body appears to have two parts 14 a and 14 b , and attached to the sleeve 10 and one attached to tube 12 . However, as the transverse sectional view of FIG. 1 a shows, space 16 does not extend for the whole circumference of the bush.
Instead, the part 14 a and 14 b are interconnected at circumferential positions perpendicular to sectional line of FIG. 1 b , by interconnections known as struts 18 . The struts 18 determine the radial stiffness of the bush in a direction perpendicular to the line B to B.
It can be seen that the inner part 14 b of the resilient body has projections 20 thereon at a circumferential position on such that the radial width of the gap between the sleeve and the tube radially inward of the projection is less than at least one other circumferential point of the tube.
These projections locally reduce the radial width of the space 16 between the parts 14 a and 14 b of the resilient body, but there remains a gap 22 between the parts 14 a and 14 b prior to the mounting of the bush in a housing.
FIG. 1 b also shows that the sleeve 10 has a projection 24 thereon, projecting radially outwards of the sleeve. The sleeve is locally thinned by grooves 26 at the periphery of the projection 24 and the projection has a recess 28 in it outer surface. As illustrated in FIG. 1 b , the projection 24 and the sleeve 10 are made of the same material and are integrally formed.
The sleeve 10 is shown in perspective view in FIG. 2 which illustrates that the sleeve 10 has a rim 30 at the axial ends thereof,
FIG. 3 then shows a perspective view similar to that of FIG. 2 , but showing the whole of the bush illustrated in FIGS. 1 a and 1 b . The struts 18 can be seen more clearly in that view.
It should also be noted that the inner tube 12 has an inner bore 32 , which will receive a bolt to attach it to an automobile chassis (not shown).
The bush of FIGS. 1 to 3 is then mounted in a bore of a housing embedded in an automobile sub-frame. The resulting structure is shown in FIGS. 4 a and 4 b , in which the housing is shown schematically by reference numeral 40 .
Other features of the bush are the same as in FIGS. 1 a and 1 b and shown by the same reference numerals. Some reference numerals are omitted for the sake of clarity.
As is conventional, the bush, when manufactured has a slightly greater diameter than the diameter of the bore of the housing 40 in to which the bush is mounted. This causes overall compression of the bush by e.g. about 3%, and this compresses the resilient material of the body (comprising parts 14 a and 14 b ) to eliminate post-moulding shrinkage stresses and also to cause the outer surface of the sleeve 10 to press against the inner wall 42 of the housing 40 so that the sleeve is gripped by the housing.
However, since the projections 24 project outwardly of the sleeve, they abut against the wall 42 of the bore of the housing 40 , locally deforming the sleeve 10 inwardly.
This reduces the space 16 to bring the parts 14 a to 14 b of the resilient body into abutment along the line A to A. In that direction the radial stiffness of the bush is determined by the abutment of parts 14 a and 14 b of the resilient body.
Typically, the additional deformation of the sleeve 10 at the position of the projections 24 is of the order of 1% to 5%, preferably around 2.7%.
With such a bush, the radial stiffness in the direction perpendicular to the line A to A is of the order of 1650N/mm, as previously mentioned, and the radial stiffness in the direction along the line A to A is of the order of 500N/mm.
Thus, significantly different stiffnesses can be achieved in different radial directions, and the value of the radial stiffness in the direction A to A can be determined by the size and configuration of the projections 24 .
Without the projections, it is generally found that the stiffnesses are too low.
The sleeve is preferably made of nylon, preferably glass filled nylon 6.6 the glass filled range of which is 0% to 30%.
The resilient material of the body 14 formed by parts 14 a and 14 b is normally of rubber.
The projections 24 may be circular or oval, and preferably are positioned at the axial mid point of the bush as illustrated in the embodiment discussed above. Although the embodiment discussed above shows the projections at opposite ends of a diameter, this is not essential and it could be at any circumferential positions on the sleeve.
There are preferably two projections, but more may be provided if more complicated stiffness characteristics were to be needed. It would also be possible to have projections of different heights at different circumferential positions. | A bush assembly is seated in a housing, having an outer sleeve ( 10 ), an inner tube ( 12 ) and a resilient body ( 14 ) connecting the inner tube ( 12 ) and the outer sleeve ( 10 ). The outer sleeve ( 10 ) has projections ( 20 ) from its outer surface that abut the inner surface of the housing ( 40 ) and cause local deformations on the sleeve around the projections ( 20 ). The local deformations around the projections ( 20 ) cause the radial gap ( 16 ) between the inner tube ( 12 ) and the outer sleeve ( 10 ) to change circumferentially and thus bush has different radial stiffness in different directions. | 5 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a Continuation of U.S. Ser. No. 12/246,431 filed on Oct. 6, 2008, which is a Continuation of U.S. Ser. No. 10/920,368 filed on Aug. 18, 2004, which is a Continuation of U.S. Ser. No. 10/040,472 filed on Jan. 9, 2002, now issued U.S. Pat. No. 6,942,334 all of which are herein incorporated be reference.
BACKGROUND
The following invention relates to a hand-held computing device, of the type commonly referred to as a personal digital assistant, with an internal printer. More particularly, though not exclusively, the invention relates to a personal digital assistant having a pagewidth drop-on-demand printhead and a source of print media located in the personal digital assistant.
A personal digital assistant, such as the type commonly known under the trade mark Palm Pilot, is typically a hand-held portable electronic device having a fold down display screen and a control panel. The display screen is typically of a touch screen type that reacts to touches made by a user controlling a pixel pen. Alternatively user inputs are provided to the digital assistant through a keypad or in-built curser ball.
Personal digital assistants provide a user with the convenience to be able to store diaries, address books, meeting schedules etc in a compact, transportable form as well as to be able to instantly add new entries such as meeting notes, new addresses etc.
Much of the benefit of such portable prior art personal digital assistants is lost however if a print-out of any stored information is required. To print information, prior art digital assistants must be connected to a print device compatible with the digital assistant which requires additional cabling to be carried thus reducing the portability of the digital assistant. Alternatively the digital storage medium that stores the images within the digital assistant must be transferred to another computer having compatible software for reading the storage medium and which is connected to a printer. Each of the above alternatives can only be implemented if these other computing devices are readily at hand. The prior art personal digital assistants are thus yet to reach their maximum potential as a functional medium for storing and transporting information. With the advent of mobile communications technologies potentially allowing electronic commerce to be conducted through one's digital assistant, it is becoming essential that digital assistants have more suitable print capabilities for printing hard copies of the information stored in the digital assistant.
However, presently, printer technology has not been suitable for incorporating into personal digital assistants without a significant compromise in the size and portability of such devices.
SUMMARY
A personal digital assistant includes a body section; a display section pivotally engaged with the body section; a hinge section joining the display portion with the interface portion, and facilitating the display section to pivot with respect to the body section; an internal printer arranged in the body section; and a print media roll disposed within the hinge section. The print media roll feeds print media to the internal printer.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described by way of example with reference to the accompanying diagrammatic drawings in which:
FIG. 1 shows a three dimensional view of a print engine, including components in accordance with the invention;
FIG. 2 shows a three dimensional, exploded view of the print engine;
FIG. 3 shows a three dimensional view of the print engine with a removable print cartridge used with the print engine removed;
FIG. 4 shows a three dimensional, rear view of the print engine with the print cartridge shown in dotted lines;
FIG. 5 shows a three dimensional, sectional view of the print engine;
FIG. 6 shows a three dimensional, exploded view of a printhead sub-assembly of the print engine;
FIG. 7 shows a partly cutaway view of the printhead sub-assembly;
FIG. 8 shows a sectional end view of the printhead sub-assembly with a capping mechanism in a capping position;
FIG. 9 shows the printhead sub-assembly with the capping mechanism in its uncapped position;
FIG. 10 shows an exploded, three dimensional view of an air supply arrangement of the print engine;
FIG. 11 shows a personal digital assistant having a built in printer;
FIG. 12 shows the internal components of a personal digital assistant having a built in printer;
FIG. 13 shows a personal digital assistant with a releasable cover portion; and
FIG. 14 is a schematic block diagram of components incorporated into a personal digital assistant having a built-in printer.
DETAILED DESCRIPTION
In FIGS. 1 to 10 of the accompanying drawings, reference numeral 500 generally designates a print engine, in accordance with the invention. The print engine 500 includes a print engine assembly 502 on which a print roll cartridge 504 is removably mountable. The print cartridge 504 is described in greater detail in our co-pending applications U.S. Ser. Nos. 09/607993 and 09/607,251, the contents of that disclosure being specifically incorporated herein by reference.
The print engine assembly 502 comprises a first sub-assembly 506 and a second, printhead sub-assembly 508 .
The sub-assembly 506 includes a chassis 510 . The chassis 510 comprises a first molding 512 in which ink supply channels 514 are molded. The ink supply channels 514 supply inks from the print cartridge 504 to a printhead 516 ( FIGS. 5 to 7 ) of the printhead sub-assembly 508 . The printhead 516 prints in four colors or three colors plus ink which is visible in the infra-red light spectrum only (hereinafter referred to as ‘infra-red ink’). Accordingly, four ink supply channels 514 are defined in the molding 512 together with an air supply channel 518 . The air supply channel 518 supplies air to the printhead 516 to inhibit the build up of foreign particles on a nozzle guard of the printhead 516 .
The chassis 510 further includes a cover molding 520 . The cover molding 520 supports a pump 522 thereon. The pump 522 is a suction pump, which draws air through an air filter in the print cartridge 504 via an air inlet pin 524 and an air inlet opening 526 . Air is expelled through an outlet opening 528 into the air supply channel 518 of the chassis 510 .
The chassis 510 further supports a first drive motor in the form of a stepper motor 530 . The stepper motor 530 drives the pump 522 via a first gear train 532 . The stepper motor 530 is also connected to a drive roller 534 ( FIG. 5 ) of a roller assembly 536 of the print cartridge 504 via a second gear train 538 . The gear train 538 engages an engageable element 540 ( FIG. 2 ) carried at an end of the drive roller 534 . The stepper motor 530 thus controls the feed of print media 542 to the printhead 516 of the sub-assembly 508 to enable an image to be printed on the print media 542 as it passes beneath the printhead 516 . It also to be noted that, as the stepper motor 530 is only operated to advance the print media 542 , the pump 522 is only operational to blow air over the printhead 516 when printing takes place on the print media 542 .
The molding 512 of the chassis 510 also supports a plurality of ink supply conduits in the form of pins 544 which are in communication with the ink supply channels 514 . The ink supply pins 544 are received through an elastomeric collar assembly 546 of the print cartridge 504 for drawing ink from ink chambers or reservoirs 548 ( FIG. 5 ) in the print cartridge 504 to be supplied to the printhead 516 .
A second motor 550 , which is a DC motor, is supported on the cover molding 520 of the chassis 510 via clips 552 . The motor 550 is provided to drive a separating means in the form of a cutter arm assembly 554 to part a piece of the print media 542 , after an image has been printed thereon, from a remainder of the print media. The motor 550 carries a beveled gear 556 on an output shaft thereof. The beveled gear 556 meshes with a beveled gear 558 carried on a worm gear 560 of the cutter assembly 554 . The worm gear 560 is rotatably supported via bearings 562 in a chassis base plate 564 of the printhead sub-assembly 508 .
The cutter assembly 554 includes a cutter wheel 566 , which is supported on a resiliently flexible arm 568 on a mounting block 570 . The worm gear 560 passes through the mounting block 570 such that, when the worm gear 560 is rotated, the mounting block 570 and the cutter wheel 566 traverse the chassis base plate 564 . The mounting block 570 bears against a lip 572 of the base plate 564 to inhibit rotation of the mounting block 570 relative to the worm gear 560 . Further, to effect cutting of the print media 542 , the cutter wheel 566 bears against an upper housing or cap portion 574 of the printhead sub-assembly 508 . This cap portion 574 is a metal portion. Hence, as the cutter wheel 566 traverses the capped portion 574 , a scissors-like cutting action is imparted to the print media to separate that part of the print media 542 on which the image has been printed.
The sub-assembly 506 includes an ejector mechanism 576 . The ejector mechanism 576 is carried on the chassis 510 and has a collar 578 having clips 580 , which clip and affix the ejector mechanism 576 to the chassis 510 . The collar 578 supports an insert 582 of an elastomeric material therein. The elastomeric insert 582 defines a plurality of openings 584 . The openings 584 close off inlet openings of the pins 544 to inhibit the ingress of foreign particles into the pins 544 and, in so doing, into the channels 514 and the printhead 516 . In addition, the insert 584 defines a land or platform 586 which closes off an inlet opening of the air inlet pin 524 for the same purposes.
A coil spring 588 is arranged between the chassis 510 and the collar 578 to urge the collar 578 to a spaced position relative to the chassis 510 when the cartridge 504 is removed from the print engine 500 , as shown in greater detail in FIG. 3 of the drawings. The ejector mechanism 576 is shown in its retracted position in FIG. 4 of the drawings.
The printhead sub-assembly 508 includes, as described above, the base plate 564 . A capping mechanism 590 is supported displaceably on the base plate 564 to be displaceable towards and away from the printhead 516 . The capping mechanism 590 includes an elongate rib 592 arranged on a carrier 593 . The carrier is supported by a displacement mechanism 594 , which displaces the rib 592 into abutment with the printhead 516 when the printhead 516 is inoperative. Conversely, when the printhead 516 is operational, the displacement mechanism 594 is operable to retract the rib 592 out of abutment with the printhead 516 .
The printhead sub-assembly 508 includes a printhead support molding 596 on which the printhead 516 is mounted. The molding 596 , together with an insert 599 arranged in the molding 596 , defines a passage 598 through which the print media 542 passes when an image is to be printed thereon. A groove 700 is defined in the molding 596 through which the capping mechanism 590 projects when the capping mechanism 590 is in its capping position.
An ink feed arrangement 702 is supported by the insert 599 beneath the cap portion 574 . The ink feed arrangement 702 comprises a spine portion 704 and a casing 706 mounted on the spine portion 704 . The spine portion 704 and the casing 706 , between them, define ink feed galleries 708 which are in communication with the ink supply channels 514 in the chassis 510 for feeding ink via passages 710 ( FIG. 7 ) to the printhead 516 .
An air supply channel 711 ( FIG. 8 ) is defined in the spine portion 704 , alongside the printhead 516 .
Electrical signals are provided to the printhead 516 via a TAB film 712 which is held captive between the insert 599 and the ink feed arrangement 702 .
The molding 596 includes an angled wing portion 714 . A flexible printed circuit board (PCB) 716 is supported on and secured to the wing portion 714 . The flex PCB 716 makes electrical contact with the TAB film 712 by being urged into engagement with the TAB film 712 via a rib 718 of the insert 599 . The flex PCB 716 supports busbars 720 thereon. The busbars 720 provide power to the printhead 516 and to the other powered components of the print engine 500 . Further, a camera print engine control chip 721 is supported on the flex PCB 716 together with a QA chip (not shown) which authenticates that the cartridge 504 is compatible and compliant with the print engine 500 . For this purpose, the PCB 716 includes contacts 723 , which engage contacts 725 in the print cartridge 504 .
As illustrated more clearly in FIG. 7 of the drawings, the printhead itself includes a nozzle guard 722 arranged on a silicon wafer 724 . The ink is supplied to a nozzle array (not shown) of the printhead 516 via an ink supply member 726 . The ink supply member 726 communicates with outlets of the passages 710 of the ink feed arrangement 702 for feeding ink to the array of nozzles of the printhead 516 , on demand.
In FIG. 10 , the air supply path for supplying air to the printhead 516 is shown in greater detail. As illustrated, the pump 522 includes an impeller 728 closed off by an end cap 730 . The cover molding 520 of the chassis forms a receptacle 732 for the impeller 728 . The cover molding 520 has the air inlet opening 734 and the air outlet opening 736 . The air inlet opening 734 communicates with the pin 524 . The air outlet opening 736 feeds air to the air supply channel 518 which, in FIG. 10 , is shown as a solid black line. The air fed from the air supply channel 518 is blown into the printhead 516 to effect cleaning of the printhead. The air drawn in via the pump 522 is filtered by an air filter 738 , which is accommodated in the print cartridge 504 . The air filter 738 has a filter element 740 which may be paper based or made of some other suitable filtering media. The filter element 740 is housed in a canister, having a base 742 and a lid 744 . The lid 744 has an opening 746 defined therein. The opening 746 is closed off by a film 748 which is pierced by the pin 524 . The advantage of having the air filter 738 in the print cartridge 504 is that the air filter 738 is replaced when the print cartridge 504 is replaced.
It is an advantage of the invention that an air pump 522 is driven by the stepper motor 530 , which also controls feed of the print media to the printhead 516 . In so doing, fewer components are required for the print engine 500 rendering it more compact. In addition, as the same motor 530 is used for operating the air pump 522 and for feeding the print media 542 to the printhead 516 , fewer power consuming components are included in the print engine 500 rendering it more compact and cheaper to produce.
It is also to be noted that, in order to make the print engine 500 more compact, the size of the print engine assembly 502 is such that most of the components of the assembly 502 are received within a footprint of an end of the print cartridge 504 .
In FIG. 11 there is depicted a personal digital assistant having an internal printer. The digital assistant 901 includes a body section 902 housing the main circuitry of the digital assistant including a digital storage medium. A display screen 904 is pivotably connected to the body section 902 about a hinge joint 905 . The screen 904 pivots between a closed position ( FIG. 12 ) where the screen lies adjacent the body section 902 thus allowing safe transport, and an open position ( FIG. 11 ) where the screen 904 is visible to a user.
The body section 902 includes a control panel 906 on an upper surface thereof that includes all buttons required to operate the functions of the digital assistant including the functions of the printer. Using this control panel, a user can selectively view any stored information and make any new entries or amendments. The control panel also includes keys allowing the user to selectively print any of the stored information. A slot 910 in the front edge of the body is used for ejecting printed media 911 .
The display screen is of a known touch screen type allowing a user to control the digital assistant using a compatible pixel pen (not shown) through which the user selects items on a displayed menu. In addition the digital assistant may include known pattern recognition software that allows a user to enter information by writing on the screen whereafter the user's input is analysed and converted into text.
In FIG. 14 there is schematically depicted in block diagram form the key internal components of a personal digital assistant having an internal printer. The printer would typically utilize a monolithic printhead 814 which could be the same as described above with reference to FIGS. 1 to 10 , but could alternatively be another compact printhead capable of printing on suitably sized print media. Print data from the memory 909 of the digital assistant or a display screen dump 904 is fed to a print engine controller 813 which controls the printhead 814 .
A micro-controller 807 associated with the print engine controller controls a motor driver 809 which in turn drives a media transport device 810 . This might be the same as stepper motor 530 described earlier.
The micro-controller 807 also controls a motor driver 811 which in turn controls a guillotine motor 812 to sever a printed sheet from an in-built roll of print media after an image is printed. A sheet being driven by media transport device 810 is shown at 911 in FIG. 11 . The guillotine might be of the form of cutter wheel 566 described earlier.
When ready, printer control buttons on the control panel can be depressed to activate the print engine controller to print stored information either from memory or as a screen dump from the display screen. This would in turn activate the micro-controller 807 to activate the media transport 810 and guillotine 812 .
FIG. 12 shows an internal view of the personal digital assistant in its closed position. The printer engine 500 described previously is disposed within the body section 902 with the removable print media cartridge 504 being disposed in the hinge joint 905 linking the body section 902 with the display screen 904 . Printed media ejected from the print media passage 548 of the print engine travels substantially along the inner surface of the bottom panel of the body section 902 and exits the digital assistant at ejector slot 910 . Because the print roll 504 is disposed within the hinge joint 905 , the personal digital assistant of the present invention can be made substantially the same size as prior art digital assistants
The body section 902 and hinge 905 include a releasable portion 912 pivotably connected through a hinge 913 and secured in a closed position by a catch 914 . Opening of this portion ( FIG. 13 ) allows the ink containing print roll cartridge 504 to be removed and replaced. Further details of a removable print roll cartridge are described in our co-pending application U.S. Ser. No. 09/607993 mentioned earlier.
While particular embodiments of this invention have been described, it will be evident to those skilled in the art that the present invention may be embodied in other specific forms without departing from the essential characteristics thereof. The present embodiments and examples are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. It will further be understood that any reference herein to known prior art does not, unless the contrary indication appears, constitute an admission that such prior art is commonly known by those skilled in the art to which the invention relates. | A personal digital assistant includes a body section; a display section pivotally engaged with the body section; a hinge section joining the display portion with the interface portion, and facilitating the display section to pivot with respect to the body section; an internal printer arranged in the body section; and a print media roll disposed within the hinge section. The print media roll feeds print media to the internal printer. | 1 |
CROSS-REFERENCE TO RELATED APPLICATION(S)
This application claims the benefit under 35 U.S.C. §119(a) of Russian Patent Application No. 2011137643, filed on Sep. 13, 2011, in the Russian Federal Service for Intellectual Property, and Korean Patent Application No. 10-2012-0087361, filed on Aug. 9, 2012, in the Korean Intellectual Property Office, the entire disclosures of which are incorporated herein by reference for all purposes.
BACKGROUND
1. Field
The following description relates to a system and a device for transferring power without a cable.
2. Description of Related Art
Electromagnetic wireless power transfer systems are classified into radiative systems and non-radiative systems. Radiative power transfer systems are based on narrow-beam transmitters, and utilize electromagnetic radiation in a far field. Non-radiative power transfer systems are based on electromagnetic induction, and utilize non-radiation in a near field.
Interest in non-radiative power transfer systems has grown significantly after a resonance power transfer scheme was proposed. Nearly all known resonance-based devices transferring wireless power are based on electromagnetic resonator structures. Resonator structures used for resonance power transfer systems may also be used in non-resonance systems, for example, radiative systems.
A drawback of electromagnetic resonator structures includes the complicated process of manufacturing a small-sized, sensitive electromagnetic resonator with a high quality factor (Q-factor, Q). Another drawback includes complications with production of an electromagnetic resonator including a high Q-factor but a low resonance frequency. To increase an efficiency of a power transfer process, it is desirable to a make Q-factor of an electromagnetic resonator as high as possible.
SUMMARY
In one general aspect, there is provided a wireless electromagnetic receiver including a first device configured to be magnetized based on an electromagnetic field. The wireless electromagnetic receiver further includes a second device configured to transform the magnetization of the first device into a power, the second device being not in contact with the first device.
The first device may include an integral solid-state mechanical resonator made of a magnetostrictive material, the integral solid-state mechanical resonator configured to be magnetized based on the electromagnetic field. The second device may include an inductive transducer configured to transform the magnetization of the integral solid-state mechanical resonator into the power, the inductive transducer being not mechanically-connected to the integral solid-state mechanical resonator.
The electromagnetic field may be at a frequency corresponding to a resonance frequency of the first device.
The second device may be further configured to maintain a quality factor (Q-factor) of the first device.
The first device may be made of a magnetostrictive material with a Q-factor including a value exceeding 2000.
The first device may be made of a magnetostrictive ferrite.
The first device may include a shape so that the power includes a peak value at an operating frequency.
The first device may include a shape of a cylinder.
The first device may include a shape of a bar with a square cross-section.
The first device may include a shape of a plate.
The wireless electromagnetic receiver may further include a permanent magnet configured to bias the first device.
The permanent magnet may be made of magnetic ceramics.
The second device may include a coil wound around the first device.
The wireless electromagnetic receiver may further include a load connected to ends of the coil.
In another general aspect, there is provided a wireless power transfer system including a transmitter configured to generate a magnetic field to transmit power. The wireless power transfer system further includes a wireless electromagnetic receiver configured to receive the power from the transmitter. The wireless electromagnetic receiver includes a first device configured to be magnetized based on the magnetic field. The wireless electromagnetic receiver further includes a second device configured to transform the magnetization of the first device into the power, the second device being not in contact with the first device.
The transmitter may include a non-radiative resonance structure with a resonance frequency f that is located at a distance less than a wavelength λ from the wireless electromagnetic receiver, where λ=c/f, and c denotes a speed of light.
The transmitter may include a non-radiative non-resonance structure located at a distance less than a wavelength λ from the wireless electromagnetic receiver, where λ=c/f, and c denotes a speed of light.
The transmitter may include a radiative structure with a frequency f that is located at a distance greater than a wavelength λ from the wireless electromagnetic receiver, where λ=c/f, and c denotes a speed of light.
Other features and aspects will be apparent from the following detailed description, the drawings, and the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram illustrating an example of a wireless power transfer system.
FIG. 2 is a diagram illustrating an example of a wireless electromagnetic receiver.
FIG. 3 is a diagram illustrating another example of a wireless electromagnetic receiver.
FIG. 4 is a diagram illustrating another example of a wireless power transfer system.
Throughout the drawings and the detailed description, unless otherwise described, the same drawing reference numerals will be understood to refer to the same elements, features, and structures. The relative size and depiction of these elements may be exaggerated for clarity, illustration, and convenience.
DETAILED DESCRIPTION
The following detailed description is provided to assist the reader in gaining a comprehensive understanding of the methods, apparatuses, and/or systems described herein. Accordingly, various changes, modifications, and equivalents of the systems, apparatuses, and/or methods described herein will be suggested to those of ordinary skill in the art. The progression of processing steps and/or operations described is an example; however, the sequence of steps and/or operations is not limited to that set forth herein and may be changed as is known in the art, with the exception of steps and/or operations necessarily occurring in a certain order. Also, description of well-known functions and constructions may be omitted for increased clarity and conciseness.
FIG. 1 is a diagram illustrating an example of a wireless power transfer system. Referring to FIG. 1 , the wireless power transfer system includes a source device 110 and a target device 120 . The source device 110 is a device supplying wireless power, and may be any of various devices that supply power, such as pads, terminals, televisions (TVs), and any other device that supplies power. The target device 120 is a device receiving wireless power, and may be any of various devices that consume power, such as terminals, TVs, vehicles, washing machines, radios, lighting systems, and any other device that consumes power.
The source device 110 includes a variable switching mode power supply (SMPS) 111 , a power amplifier 112 , a matching network 113 , a controller 114 , a communication unit 115 , a power detector 116 , and a source resonator 131 . The target device 120 includes a matching network 121 , a rectifier 122 , a direct current-to-direct current (DC/DC) converter 123 , a communication unit 124 , a controller 125 , a power detector 127 , and a target resonator 133 .
The variable SMPS 111 generates a DC voltage by switching an alternating current (AC) voltage having a frequency of tens of hertz (Hz) output from a power supply. The variable SMPS 111 may output a DC voltage having a predetermined level, or may output a DC voltage having an adjustable level by the controller 114 .
The power detector 116 detects an output current and an output voltage of the variable SMPS 111 , and provides, to the controller 114 , information on the detected current and the detected voltage. Additionally, the power detector 116 detects an input current and an input voltage of the power amplifier 112 .
The power amplifier 112 generates a power by converting the DC voltage output from the variable SMPS 111 to an AC voltage using a switching pulse signal having a frequency of a few kilohertz (kHz) to tens of megahertz (MHz). In other words, the power amplifier 112 converts a DC voltage supplied to a power amplifier to an AC voltage using a reference resonance frequency F Ref , and generates a communication power to be used for communication, or a charging power to be used for charging that may be used in a plurality of target devices. The communication power may be, for example, a low power of 0.1 to 1 milliwatts (mW) that may be used by a target device to perform communication, and the charging power may be, for example, a high power of 1 mW to 200 Watts (W) that may be consumed by a device load of a target device. In this description, the term “charging” may refer to supplying power to an element or a unit that charges a battery or other rechargeable device with power. Also, the term “charging” may refer supplying power to an element or a unit that consumes power. For example, the term “charging power” may refer to power consumed by a target device while operating, or power used to charge a battery of the target device. The unit or the element may include, for example, a battery, a display device, a sound output circuit, a main processor, and various types of sensors.
In this description, the term “reference resonance frequency” refers to a resonance frequency that is nominally used by the source device 110 , and the term “tracking frequency” refers to a resonance frequency used by the source device 110 that has been adjusted based on a predetermined scheme.
The controller 114 may detect a reflected wave of the communication power or a reflected wave of the charging power, and may detect mismatching between the target resonator 133 and the source resonator 131 based on the detected reflected wave. The controller 114 may detect the mismatching by detecting an envelope of the reflected wave, or by detecting an amount of a power of the reflected wave.
Under the control of the controller 114 , the matching network 113 compensates for impedance mismatching between the source resonator 131 and the target resonator 133 so that the source resonator 131 and the target resonator 133 are optimally-matched. The matching network 113 includes combinations of a capacitor and an inductor that are connected to the controller 114 through a switch, which is under the control of the controller 114 .
The controller 114 may calculate a voltage standing wave ratio (VSWR) based on a voltage level of the reflected wave and a level of an output voltage of the source resonator 131 or the power amplifier 112 . When the VSWR is greater than a predetermined value, the controller 114 detects the mismatching. In this example, the controller 114 calculates a power transmission efficiency of each of N predetermined tracking frequencies, determines a tracking frequency F Best having the best power transmission efficiency among the N predetermined tracking frequencies, and changes the reference resonance frequency F Ref to the tracking frequency F Best .
Also, the controller 114 may control a frequency of the switching pulse signal used by the power amplifier 112 . By controlling the switching pulse signal used by the power amplifier 112 , the controller 114 may generate a modulation signal to be transmitted to the target device 120 . In other words, the communication unit 115 may transmit various messages to the target device 120 via in-band communication. Additionally, the controller 114 may detect a reflected wave, and may demodulate a signal received from the target device 120 through an envelope of the reflected wave.
The controller 114 may generate a modulation signal for in-band communication using various schemes. To generate a modulation signal, the controller 114 may turn on or off the switching pulse signal used by the power amplifier 112 , or may perform delta-sigma modulation. Additionally, the controller 114 may generate a pulse-width modulation (PWM) signal having a predetermined envelope.
The communication unit 115 may perform out-of-band communication using a communication channel. The communication unit 115 may include a communication module, such as a ZigBee module, a Bluetooth module, or any other communication module, that the communication unit 115 may use to perform the out-of-band communication. The communication unit 115 may transmit or receive data 140 to or from the target device 120 via the out-of-band communication.
The source resonator 131 transfers electromagnetic energy 130 , such as the communication power or the charging power, to the target resonator 133 via a magnetic coupling with the target resonator 133 .
The target resonator 133 receives the electromagnetic energy 130 , such as the communication power or the charging power, from the source resonator 131 via a magnetic coupling with the source resonator 131 . Additionally, the target resonator 133 receives various messages from the source device 110 via the in-band communication.
The matching network 121 matches an input impedance viewed from the source device 110 to an output impedance viewed from a load. The matching network 121 may be configured with a combination of a capacitor and an inductor.
The rectifier 122 generates a DC voltage by rectifying an AC voltage received by the target resonator 133 .
The DC/DC converter 123 adjusts a level of the DC voltage output from the rectifier 122 based on a voltage rating of the load. For example, the DC/DC converter 123 may adjust the level of the DC voltage output from the rectifier 122 to a level in a range from 3 volts (V) to 10 V.
The power detector 127 detects a voltage of an input terminal 126 of the DC/DC converter 123 , and a current and a voltage of an output terminal of the DC/DC converter 123 . The power detector 127 outputs the detected voltage of the input terminal 126 , and the detected current and the detected voltage of the output terminal, to the controller 125 . The controller 125 uses the detected voltage of the input terminal 126 to compute a transmission efficiency of power received from the source device 110 . Additionally, the controller 125 uses the detected current and the detected voltage of the output terminal to compute an amount of power transferred to the load. The controller 114 of the source device 110 determines an amount of power that needs to be transmitted by the source device 110 based on an amount of power required by the load and the amount of power transferred to the load. When the communication unit 124 transfers an amount of power of the output terminal (e.g., the computed amount of power transferred to the load) to the source device 110 , the controller 114 of the source device 110 may compute the amount of power that needs to be transmitted by the source device 110 .
The communication unit 124 may perform in-band communication for transmitting or receiving data using a resonance frequency by demodulating a received signal obtained by detecting a signal between the target resonator 133 and the rectifier 122 , or by detecting an output signal of the rectifier 122 . In other words, the controller 125 may demodulate a message received via the in-band communication.
Additionally, the controller 125 may adjust an impedance of the target resonator 133 to modulate a signal to be transmitted to the source device 110 . For example, the controller 125 may increase the impedance of the target resonator so that a reflected wave will be detected by the controller 114 of the source device 110 . In this example, depending on whether the reflected wave is detected, the controller 114 of the source device 110 will detect a binary number “0” or “1”.
The communication unit 124 may transmit, to the source device 110 , any one or any combination of a response message including a product type of a corresponding target device, manufacturer information of the corresponding target device, a product model name of the corresponding target device, a battery type of the corresponding target device, a charging scheme of the corresponding target device, an impedance value of a load of the corresponding target device, information about a characteristic of a target resonator of the corresponding target device, information about a frequency band used the corresponding target device, an amount of power to be used by the corresponding target device, an intrinsic identifier of the corresponding target device, product version information of the corresponding target device, and standards information of the corresponding target device.
The communication unit 124 may also perform an out-of-band communication using a communication channel. The communication unit 124 may include a communication module, such as a ZigBee module, a Bluetooth module, or any other communication module known in the art, that the communication unit 124 may use to transmit or receive data 140 to or from the source device 110 via the out-of-band communication.
The communication unit 124 may receive a wake-up request message from the source device 110 , detect an amount of a power received by the target resonator, and transmit, to the source device 110 , information about the amount of the power received by the target resonator. In this example, the information about the amount of the power received by the target resonator may correspond to an input voltage value and an input current value of the rectifier 122 , an output voltage value and an output current value of the rectifier 122 , or an output voltage value and an output current value of the DC/DC converter 123 .
The controller 114 of the source device 110 may set a resonance bandwidth of the source resonator 131 . Based on the set resonance bandwidth of the source resonator 131 , a Q-factor Q S of the source resonator 131 may be determined.
The controller 125 may set a resonance bandwidth of the target resonator 133 . Based on the set resonance bandwidth of the target resonator 133 , a Q-factor Q D of the target resonator 133 may be determined. In this example, the resonance bandwidth of the source resonator 131 may be set to be wider or narrower than the resonance bandwidth of the target resonator 133 . By communicating with each other, the source device 110 and the target device 120 may share information regarding the resonance bandwidths of the source resonator 131 and the target resonator 133 . When a power higher than a reference value is requested by the target device 120 , the Q-factor Q S of the source resonator 131 may be set to a value greater than 100. When a power lower than the reference value is requested by the target device 120 , the Q-factor Q S of the source resonator 131 may be set to a value less than 100.
In resonance-based wireless power transmission, a resonance bandwidth is a significant factor. If Qt indicates a Q-factor based on a change in a distance between the source resonator 131 and the target resonator 133 , a change in a resonance impedance, impedance-mismatching, a reflected signal, or any other factor affecting a Q-factor, Qt is inversely proportional to a resonance bandwidth as expressed by the following Equation 1:
Δ
f
f
0
=
1
Qt
=
Γ
S
,
D
+
1
BW
S
+
1
BW
D
(
1
)
In Equation 1, f 0 denotes a center frequency, Δf denotes a bandwidth, Γ S,D denotes a reflection loss between resonators, BW S denotes a resonance bandwidth of the source resonator 131 , and BW D denotes a resonance bandwidth of the target resonator 133 .
An efficiency U of wireless power transmission may be expressed by the following Equation 2:
U
=
κ
Γ
S
Γ
D
=
ω
0
M
R
S
R
D
=
Q
S
Q
D
Q
κ
(
2
)
In Equation 2, κ denotes a coupling coefficient of energy coupling between the source resonator 131 and the target resonator 133 , Γ S denotes a reflection coefficient of the source resonator 131 , Γ D denotes a reflection coefficient of the target resonator 133 , ω 0 denotes a resonance frequency, M denotes a mutual inductance between the source resonator 131 and the target resonator 133 , R S denotes an impedance of the source resonator 131 , R D denotes an impedance of the target resonator 133 , Q S denotes a Q-factor of the source resonator 131 , Q D denotes a Q-factor of the target resonator 133 , and Q κ denotes a Q-factor of energy coupling between the source resonator 131 and the target resonator 133 .
As can be seen from Equation 2, the Q-factor has a great effect on an efficiency of the wireless power transmission. Accordingly, the Q-factor may be set to a high value to increase the efficiency of the wireless power transmission. However, even when Q S and Q D are set to high values, the efficiency of the wireless power transmission may be reduced by a change in the coupling coefficient κ of the energy coupling, a change in a distance between the source resonator 131 and the target resonator 133 , a change in a resonance impedance, impedance mismatching, and any other factor affecting the efficiency of the wireless power transmission.
If the resonance bandwidths BW S and BW D of the source resonator 131 and the target resonator 133 are set to be too narrow to increase the efficiency of the wireless power transmission, impedance mismatching and other undesirable conditions may easily occur due to insignificant external influences. In order to account for the effect of impedance mismatching, Equation 1 may be rewritten as the following Equation 3:
Δ
f
f
0
=
VSWR
-
1
Qt
VSWR
(
3
)
The source device 110 may wirelessly transmit wake-up power used to wake up the target device 120 , and may broadcast a configuration signal used to configure a wireless power transfer network. The source device 110 may receive, from the target device 120 , a search frame including a value of a receiving sensitivity of the configuration signal, may permit a join of the target device 120 , and may transmit an ID used to identify the target device 120 in the wireless power transfer network. Additionally, the source device 110 generates charging power through power control, and wirelessly transmits the charging power to the target device 120 .
Additionally, the target device 120 may receive wake-up power from at least one of source devices, and may activate a communication function of the target device 120 using the wake-up power. The target device 120 may receive a configuration signal used to configure a wireless power transfer network of each of the source devices, may select the source device 110 based on a receiving sensitivity of the respective configuration signal, and wirelessly receives power from the selected source device 110 .
FIG. 2 is a diagram illustrating an example of a wireless electromagnetic receiver 200 . Referring to FIG. 2 , the wireless electromagnetic receiver 200 includes an inductive transducer and a solid-state resonator 210 .
The inductive transducer includes a coil 250 . The coil 250 is wrapped around the solid-state resonator 210 without being mechanically-connected to the solid-state resonator 210 .
The solid-state resonator 210 includes a shape of a cylinder. The solid-state resonator 210 is made of a magnetostrictive material.
The wireless electromagnetic receiver 200 further includes a permanent magnet 220 configured at a side of (e.g., below) the inductive transducer and the solid-state resonator 210 . The permanent magnet 220 includes a shape of a bar with a square cross-section, although other geometric shapes known to one of ordinary skill in the art may be included. The bar of the permanent magnet 220 may be approximately parallel to the cylinder of the solid-state resonator 210 .
A source device produces a variable magnetic field 230 configured to excite the solid-state resonator 210 , e.g., to cause the solid-state resonator 210 to oscillate. The variable magnetic field 230 is used to transfer power to the wireless electromagnetic receiver 200 .
The wireless electromagnetic receiver 200 further includes a load 240 . The load 240 is connected to the coil 250 via, e.g., thin conductive layers.
FIG. 3 is a diagram illustrating another example of a wireless electromagnetic receiver 300 . Referring to FIG. 3 , the wireless electromagnetic receiver 300 includes an inductive transducer and a solid-state resonator 310 .
The inductive transducer includes a coil 350 . The coil 350 is wrapped around the solid-state resonator 310 without being mechanically-connected to the solid-state resonator 310 .
The solid-state resonator 310 includes a shape of a bar with a square cross-section. The solid-state resonator 310 is made of a magnetostrictive material.
The wireless electromagnetic receiver 300 further includes a permanent magnet 320 configured at a side of (e.g., below) the inductive transducer and the solid-state resonator 310 . The permanent magnet 320 includes a shape of a bar with a square cross-section, although other geometric shapes known to one of ordinary skill in the art may be included. The bar of the permanent magnet 320 may be approximately parallel to the bar of the solid-state resonator 310 .
A source device produces a variable magnetic field 330 configured to excite the solid-state resonator 310 , e.g., to cause the solid-state resonator 310 to oscillate. The variable magnetic field 330 is used to transfer power to the wireless electromagnetic receiver 300 .
The wireless electromagnetic receiver 300 further includes a load 340 . The load 340 is connected to the coil 350 via, e.g., thin conductive layers.
FIG. 4 is a diagram illustrating another example of a wireless power transfer system. Referring to FIG. 4 , the wireless power transfer system includes a source device 410 and a wireless electromagnetic receiver 430 .
The source device 410 generates a variable magnetic field 420 , to transfer power to the wireless electromagnetic receiver 430 via the variable magnetic field 420 . The wireless electromagnetic receiver 430 may include the wireless electromagnetic receiver 200 of FIG. 2 or the wireless electromagnetic receiver 300 of FIG. 3 , and receives the power from the source device 410 via the variable magnetic field 420 .
Referring to FIGS. 2 through 4 , a first functional portion of the wireless electromagnetic receiver 430 may be represented by the solid-state resonator 210 and the permanent magnet 220 of FIG. 2 , or by the solid-state resonator 310 and the permanent magnet 320 of FIG. 3 . The solid-state resonator 210 or 310 may be made of a magnetostrictive material with a high Q-factor exceeding, e.g., 2000. For example, a magnetostrictive ferrite may be used as the magnetostrictive material. The solid-state resonator 210 or 310 may include a shape of a plate, a cylinder (as shown in FIG. 2 ), a rectangular rod or bar, a bar with a square cross-section (as shown in FIG. 3 ), or other geometric shapes known to one of ordinary skill in the art. The geometric shape of the solid-state resonator 210 or 310 may be selected so that the solid-state resonator 210 or 310 operates (e.g., oscillates) in a mechanical resonance mode at an operating frequency f. For example, for the solid-state resonator 210 or 310 to operate in a longitudinal mechanical resonance mode, a size of the solid-state resonator 210 or 310 , in at least one dimension, may need to be approximately equal to v/(2f) in which v is a sound velocity. The mechanical resonance mode may be an optimal method for power transfer in an example in which a maximum amount of mechanical energy is stored in the solid-state resonator 210 or 310 , or power of mechanical oscillations of the solid-state resonator 210 or 310 includes a peak value.
The solid-state resonator 210 or 310 is biased by the permanent magnet 220 or 320 located at a short distance from the solid-state resonator 210 or 310 to ensure magnetostrictive properties of the magnetostrictive material forming the solid-state resonator 210 or 310 , and to linearize a behavior of the solid-state resonator 210 or 310 . The permanent magnet 220 or 320 may be made of a ceramic material. The permanent magnet 220 or 320 may be configured close to the solid-state resonator 210 or 310 , without a considerable impact on a system efficiency.
The solid-state resonator 210 or 310 is excited by the variable magnetic field 230 or 330 . That is, the variable magnetic field 230 or 330 generates the mechanical oscillations in the solid-state resonator 210 or 310 due to a magnetostrictive phenomenon. In the mechanical resonance mode, the variable magnetic field 230 or 330 is at a frequency matched to a resonance frequency f of the solid-state resonator 210 or 310 .
An amplitude of the mechanical oscillations at the resonance frequency f depends on a Q-factor of the magnetostrictive material forming the solid-state resonator 210 or 310 . That is, the higher the Q-factor, the higher the amplitude of the mechanical oscillations. Thus, for example, a magnetostrictive material of a highest Q-factor may be used to form the solid-state resonator 210 or 310 . Additionally, the amplitude of the mechanical oscillations depends on the magnetostrictive properties of the magnetostrictive material forming the solid-state resonator 210 or 310 . Therefore, for example, highly efficient magnetostrictive materials may be used to form the solid-state resonator 210 or 310 .
Referring again to FIGS. 2 through 4 , a second functional portion of the wireless electromagnetic receiver 430 may be represented by the inductive transducers of FIG. 2 or 3 , which includes the coil 250 or 350 wound around the solid-state resonator 210 or 310 . The coil 250 or 350 is not mechanically-connected to the solid-state resonator 210 or 310 . Such a structure of the inductive transducer may ensure that the Q-factor of the solid-state resonator 210 or 310 is not reduced.
Mechanical oscillations on a surface of the solid-state resonator 210 or 310 generate a variable mechanical tension in the solid-state resonator 210 or 310 , which generates a variable component of magnetization in the solid-state resonator 210 or 310 due to the inverse magnetostrictive effect. The variable component of magnetization induces voltage oscillations at ends of the coil 250 or 350 . The ends of the coil 250 or 350 are connected to the load 240 or 340 , to transfer the voltage oscillations as power to the load 240 or 340 .
Referring again to FIG. 4 , the wireless electromagnetic receiver 430 is used as a component of the wireless power transfer system. As discussed above, the wireless power transfer system includes the source device 410 configured to generate the variable magnetic field 420 , to transfer power to the wireless electromagnetic receiver 430 via the variable magnetic field 420 . The wireless power transfer system further includes the wireless electromagnetic receiver 430 configured to receive the power from the source device 410 via the variable magnetic field 420 . A frequency of the variable magnetic field 420 generated by the source device 410 may correspond to a resonance frequency of the wireless electromagnetic receiver 430 . Thus, it is possible to use various types of source devices to generate the variable magnetic field 420 .
In a first example, the source device 410 may include a non-radiative resonance structure with a resonance frequency f that is located at a distance less than a wavelength λ from the wireless electromagnetic receiver 430 . In this example, λ=c/f, and c denotes a speed of light. Additionally, the source device 410 and the wireless electromagnetic receiver 430 constitute a resonance system for wireless power transfer.
In a second example, the source device 410 may include a non-radiative non-resonance structure. For example, the non-radiative non-resonance structure may include a coil connected to an oscillator, and may be located at a distance less than a wavelength λ from the wireless electromagnetic receiver 430 . In this example, λ=c/f, and c denotes a speed of light.
In a third example, the source device 410 may include a radiative structure with a frequency f that is located at a distance greater than a wavelength λ from the wireless electromagnetic receiver 430 . In this example, λ=c/f, and c denotes a speed of light.
According to the teachings above, there is provided a wireless power transfer system, which allows a power supply required for low-power compact devices to be without cables or wires. The wireless power transfer system may be especially suitable for use in fields in which low frequencies are preferred, for example, in biological systems.
The units described herein may be implemented using hardware components, software components, or a combination thereof. For example, the hardware components may include microphones, amplifiers, band-pass filters, audio to digital convertors, and processing devices. A processing device may be implemented using one or more general-purpose or special purpose computers, such as, for example, a processor, a controller and an arithmetic logic unit, a digital signal processor, a microcomputer, a field programmable array, a programmable logic unit, a microprocessor or any other device capable of responding to and executing instructions in a defined manner. The processing device may run an operating system (OS) and one or more software applications that run on the OS. The processing device also may access, store, manipulate, process, and create data in response to execution of the software. For purpose of simplicity, the description of a processing device is used as singular; however, one skilled in the art will appreciated that a processing device may include multiple processing elements and multiple types of processing elements. For example, a processing device may include multiple processors or a processor and a controller. In addition, different processing configurations are possible, such as parallel processors.
The software may include a computer program, a piece of code, an instruction, or some combination thereof, to independently or collectively instruct or configure the processing device to operate as desired. Software and data may be embodied permanently or temporarily in any type of machine, component, physical or virtual equipment, computer storage medium or device, or in a propagated signal wave capable of providing instructions or data to or being interpreted by the processing device. The software also may be distributed over network coupled computer systems so that the software is stored and executed in a distributed fashion. The software and data may be stored by one or more computer readable recording mediums. The computer readable recording medium may include any data storage device that can store data which can be thereafter read by a computer system or processing device. Examples of the non-transitory computer readable recording medium include read-only memory (ROM), random-access memory (RAM), CD-ROMs, magnetic tapes, floppy disks, optical data storage devices. Also, functional programs, codes, and code segments accomplishing the examples disclosed herein can be easily construed by programmers skilled in the art to which the examples pertain based on and using the flow diagrams and block diagrams of the figures and their corresponding descriptions as provided herein.
As a non-exhaustive illustration only, a device described herein may refer to mobile devices such as a cellular phone, a personal digital assistant (PDA), a digital camera, a portable game console, and an MP3 player, a portable/personal multimedia player (PMP), a handheld e-book, a portable laptop PC, a global positioning system (GPS) navigation, a tablet, a sensor, and devices such as a desktop PC, a high definition television (HDTV), an optical disc player, a setup box, a home appliance, and the like that are capable of wireless communication or network communication consistent with that which is disclosed herein.
A number of examples have been described above. Nevertheless, it will be understood that various modifications may be made. For example, suitable results may be achieved if the described techniques are performed in a different order and/or if components in a described system, architecture, device, or circuit are combined in a different manner and/or replaced or supplemented by other components or their equivalents. Accordingly, other implementations are within the scope of the following claims. | A system and a device for wirelessly transferring power without a cable are provided. A wireless electromagnetic receiver includes a first device configured to be magnetized based on an electromagnetic field. The wireless electromagnetic receiver further includes a second device configured to transform the magnetization of the first device into a power, the second device being not in contact with the first device. | 7 |
This application is a continuation of application Ser. No. 08/295,417, filed Aug. 25, 1994.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention involves the efficient generation of environmentally clean energy, focused on the commercial generation of electrical power. This invention has a number of additional industrial applications where the working fluid used requires variable temperatures and pressures such as in food processing, oil well high energy gas injection medical and greenhouse facility constant temperature control, and other applications.
2. Description of the Related Art
The current art in generating a major portion of commercial levels of electrical power, in the United States and world-wide, depends upon thermal generating plants burning hydrocarbon fuels (mainly coal and low grade fuel oils) with air, which contains 23.1% oxygen and 76.9% nitrogen by weight, to generate high enthalpy steam which, in turn, is used to drive turbo-electric generators.
The technology of designing, constructing and operating extremely high energy generators for jet engines, rocket engines, and gas turbine auxiliary power systems, has been significantly advanced in recent years. Generation and controlled use of such extremely high energy levels is a specialized practice and is readily adaptable to commercial industry.
The current state-of-the-art in power generation results in the production of atmospheric pollutants, mainly high levels of nitrogen oxides (NOx), sulfur oxides (SOx), carbon monoxide (CO) and particulate matter. Such emissions are at, and in a great many cases above, critical allowed threshold levels and must be reduced to preserve clean air. Current US regulatory requirements prescribe the amounts of the above listed atmospheric emissions permitted in particular locations by a given power generating plant. Allowable emission threshold are decreasing over time putting more and more pressure on industry to reduce emissions. Drastic economic penalties are being established, either in the form of fines (called purchased credits) related to the amounts by which emissions exceed allowable limits, or plants can be ordered to cease emitting operations.
In addition to the undesired effects of the build-up of atmospheric pollutants on the quality of the environment, current art extracts further societal prices in terms of the added costs of pollution control and monitoring equipment, and the purchasing of credits which are passed on to the consumers.
There have been many efforts to solve the emissions problem by exploiting non-combustible energy sources, such as windmills, fuel cells, solar cells, closed cycle solar reflector/boilers, use of tidal motion and others. None of these sources can approach the required output levels in a cost-effective manner, with operating efficiency required for large-scale, sustained commercial applications currently supplied by the conventional thermal power generating plants. Nuclear plants can produce at the required levels of out-puts, but they have encountered regulatory requirements leading to high costs, and there is a strong societal opposition to increasing use of nuclear power. Hence nuclear power use in the United States is severely restricted.
SUMMARY OF THE INVENTION
This invention is a unique, well developed technology for a high temperature, high pressure combustion device, designed to produce and control an efficient, high energy fluid stream, without generating unacceptable pollution, and which is usable in a variety of embodiments described in this application. The thermo-mechanical design and physical conformation are specific features the purposes of which are efficient operation, pollution avoidance, long life and minimum maintenance. These results are accomplished through unique integration of a number of advanced combustion technologies using selected reactants in a water cooled device generating a high purity steam and carbon dioxide working gas.
Elements of prior specialized technologies are adapted and combined in the design of a thermal power generating plant which can operate cleanly using any of several relatively inexpensive and widely available reactants including liquid oxygen, propane, methane, natural gas, or light alcohols such as ethanol and methanol. These reactants are or can be placed in mass commercial production and distribution, being already in extensive use in other fields such as home heating, cooking, industrial heating, metal cutting and welding, aerospace propulsion applications and others. Further, these reactants can be burned at high temperatures, in high pressure combustors which, while not currently widely used in the power industry, are a practiced art in the aerospace industries, but without emphasis on environmentally clean operation in those applications.
In this invention, the combustor is a high energy, continuous flow device. The liquid reactants are injected into a combustion chamber, via an efficient, high performance, specialized injection device, under high pressure, generating high temperature gas.
In combusting any of the fuels with liquid oxygen, under controlled conditions (i.e., combustor pressure, temperature and fuel/oxidizer mixture ratio) the products of combustion are high pressure, high temperature steam and gaseous carbon dioxide, with virtually no NOx, SOx, CO or particulates generated, depending upon the purity of the fuels and oxidizers used, and the controls of the combustion process. The carbon dioxide product can be recovered during the steam condensing process for commercial use. Current costs of the fuel elements generated in bulk by existing, large scale production facilities, are relatively cost competitive with coal and oil. The energy release in an appropriately scaled reactor produces power at a cost that is competitive with current thermal plants, yet this invention will not yield the massive amounts of polluting gases, thus avoiding the additional penalty costs of pollution control equipment and purchased credits for excess emissions.
A specially configured version of this invention takes the form of a source of a high quality fluid, which can either improve a number of existing commercial applications (e.g. food processing, materials sterilization, oil well injection, etc.), or enable new applications such as intermediately scaled mobile plants for temporary, on-site power support, or non-polluting, steam powered drive systems for large locomotion systems such as trains or ships.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic showing an embodiment of the invention, its elements and connectivity that constitute an efficient, pollution-free power generation system. Liquid reactants are shown being introduced to the system from sources that may be either on-site or adjacent production facilities, or from storage facilities. This embodiment features system enhancing elements which maximize energy utilization and minimize component size through turbine drive gas regeneration and inter-turbine drive gas reheating.
FIG. 2 is a schematic showing an embodiment of the system from which the inter-turbine reheaters were removed, which simplifies the system of FIG. 1, reduces cost, and slightly increases performance, but at the expense of increased component sizes and weights.
FIG. 3 is a schematic showing an embodiment of the system from which both the reheaters and regenerators were removed, which simplifies the system of FIG. 2, further reduces cost and decreases system performance, but at the expense of further increased component sizes and weights.
FIG. 4 is a schematic showing an adaptation of embodiment 3, from which the recirculating water circuit and customer supplied heat rejection system were eliminated, with water supplied from a source (e.g., lake, river, or purified sea water), thus eliminating the complexity and cost of the closed loop water recovery and heat rejection subsystems.
FIG. 5 is an illustration of an embodiment of the basic concept which uses those elements of the system required to generate the drive gas only. The generation of the high pressure, high temperature, high purity steam and carbon dioxide mixture that this system is capable of delivering has multiple industrial applications (e.g's., oil well injection, material sterilization, or heating of large structures or building complexes, and others).
FIG. 6 is an illustration of an embodiment that is a modification of FIG. 5, wherein the gas generator output is used to power a turbogenerator set, with components sized to mount on a mobile platform for applications such as remote site construction or exploration, auxiliary or peaking power supply, service power, or large locomotive drive applications, such as for trains or ships.
FIG. 7 is a cut-away diagram showing the elements of the main reactor (or gas generator). This illustration shows the functional elements of the device, including the reactants' inlets and manifolds, the injector, the transpiration cooled combustion chamber, and the internal mixing chamber and outlet.
FIG. 8 is a cut-away of a typical inter-turbine reheater. The device is a specialized version of the main reactor. The size of an individual reheater is dependent on the physical state of the out-flow received from the preceding turbine unit.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1. Power generation System with Reheaters and Regenerators
FIG. 1 illustrates a non-polluting, efficient electrical energy generating power plant 1000, comprising a reactant induction subsystem 100, a gas generation subsystem 200, a reheated turbine drive subsystem 300, an electrical energy generation subsystem 400, an exhaust management subsystem 500, and a regenerated water management subsystem 600.
The reactant service subsystem 100 feeds and controls the flow of the fuel and oxidizer reactants that power this system. This includes a liquid oxygen (LOX) feed line 1, feeding the LOX pump 2, which is powered by drive unit 6. The LOX pump 2 delivers high pressure LOX to the system gas generator subsystem 200, via the discharge line 3. High pressure gaseous or liquid fuel is delivered to the gas generator subsystem 200 through feed line 4.
The drive gas generator subsystem 200 includes a gas generator 7, which efficiently combusts the injected reactants under controlled conditions, producing a high pressure, high temperature gaseous mixture of steam and carbon dioxide which is delivered as a turbine drive gas. The drive gas is delivered to the high pressure turbine drive 13, in subsystem 300, via discharge line 10. Thermal control of the combustion process can be accomplished by controlling cooling water flow rate to the gas mixing chamber and to the chamber structure via water feed lines 64 and 66, supplied by water service feed line 65, from the water management subsystem 600.
The turbine drive subsystem 300, converts the gas generator subsystem 200 output energy into mechanical energy to drive the electrical generator subsystem 400. The turbine subsystem 300, consists of three power turbines, pressure staged for optimum efficiency, and two inter-turbine reheater units to maximize the energy in the drive gas.
The turbine drive subsystem 300 consists of high pressure power turbine 13, high pressure power turbine exhaust line 11, and high pressure power tap-off line 45. This assembly is followed by an inter-turbine reheater in which the exhaust temperature is brought back to that at the gas generator outlet by combusting the proper amount of the reactants in the reheater chamber and mixing the output with the main flow stream, thus adding energy and maintaining constant inlet temperature going into the next turbine. This takes place in the first inter-turbine reheater 62, which consists of the reheater 62, and reheater LOX feed line 56, reheater fuel feed line 57, reheater water feed line 68, high pressure turbine steam exhaust from line 11, and reheater discharge line 59. This section is followed by a medium pressure range power turbine 14, medium pressure power turbine discharge line 12, medium power turbine tap-off line 15, followed by the second reheater unit consisting of inter-turbine reheater 63, reheater LOX feed line 58, reheater fuel feed line 60, reheater water feed line 69, medium pressure turbine steam exhaust from line 12, and reheater discharge line 61. The turbine power section is terminated by a low pressure power turbine 17, and discharge line 25, which sends the gas flow to an exhaust recovery condenser 41, in the exhaust recovery subsystem 500.
The energy generation subsystem 400 is the electrical energy conversion facility 18, consisting of electrical generator(s), and power conditioning, which develop the end product of this plant, electrical energy.
The exhaust management subsystem 500 is a gas handling subsystem with two purposes: (i) to make the most efficient use of the exhaust products, and (ii) to verify that pollution controls are effective. This subsystem consists of a carbon dioxide recovery branch and a water recovery branch, both serviced by the heat rejection facility 30.
The carbon dioxide recovery assembly receives near ambient temperature, gaseous carbon dioxide (CO2) from the condenser 41, via discharge line 19, and from the water management subsystem 600, via discharge line 47, into compressor 20, which is powered by drive unit 21. After one stage of compression, the gas is delivered to a water cooler 26, via discharge line 23, and, after cooling by passage through the heat exchanger section of the cooler vessel 26, the fluid is returned to compressor 20, via return line 24, and further compressed before discharge to facility return line 5, for recovery processing. Cooling water is supplied to cooler 26, from the heat rejection facility 30, by cooling water pump 34, powered by drive unit 36. Cooling water is drawn through inlet line 33, and delivered through pump discharge line 31, and cooler inlet line 28. After passing through the heat exchanger element in cooler 26, the cooling water is returned to the heat rejection facility 30, via discharge line 29. Carbon dioxide is also recovered from preheater 93 via discharge line 94.
The water recovery branch consists of the condenser vessel 41, cooling water inlet line 27, which sends cooling water through the condenser 41 heat exchanger section to cool down and condense the exhausted steam back to water. The cooling water is then returned to the heat rejection facility 30, via cooling water outlet line 22, and the condensed water is returned to the water management subsystem 600, via discharge line 37.
The water management subsystem 600 maintains the proper water balance in the operating system 1000. It does this by maintaining the proper cooling water injected at the gas generator inlet. The major product of combustion, using the reactants intended for this system, is water, therefore following start-up there is more than enough water available to operate the system. However, to insure adequate water availability during start-up, shut-down, and other transient operations, the heat rejection facility will serve as a reservoir as well as a receiver for any excess water generated. The main elements in the embodiment of the water management subsystem 600 are pressure staged pumps 16a, 16b, and 16c, powered commonly by drive unit 9, condensate pump 38, powered by drive unit 39, and two (2) performance enhancing regenerator units 46 and 93.
The water recovered in the exhaust management subsystem 500 is returned to the water supply from condenser 41, discharge line 37, to condensate water pump 38, which is powered by drive unit 39. Condensate water pump 38 delivers the water to the feed water pumping system via discharge line 40. Excess water is diverted to the heat rejection facility 30, via return line 35, or any required start-up or make-up water is drawn from the heat rejection facility 30, via inlet line 95 and delivered to the inlet of pump 16a. The main water flow is delivered to the feed water pumps 16a, 16b, and 16c by the condensate pump 38, via feed line 43, which is joined by a recirculated flow from the medium pressure turbine tap-off line 15. This tap-off flow serves as the heat source in the heat exchange element of a regenerator device, regenerator 46, to conserve heat energy. The tap-off flow is collected in a sump in regenerator 46, and discharges to the low pressure feed water pump 16a, via discharge line 48, of regenerator 46 and pump 16ainlet line 43. An initial stage of feed water pressurization is accomplished in low pressure feed water pump 16a. The outflow of pump 16a is carried to regenerator 46, via discharge line 49, picks up heat energy in the heat exchanger element in regenerator 46, and then is passed to the medium pressure feed water pump 16b, via heat exchanger outlet line 50 and through inlet line 51. The water flow is joined by a recirculated flow that originates from the high pressure power turbine tap-off line 45. This tap-off flow serves as the heat source in the heat exchange element of the regenerator 93, to further conserve heat energy. The tap-off flow is collected in a sump in regenerator 93, and discharges to the medium pressure feed water pump 16b, via sump discharge line 92, of regenerator 93, and through medium pressure pump inlet line 51. The feed water flow stream is passed to the high pressure pump 16c, via medium pressure feed water pump 16b's discharge line 90. The high pressure pump 16craises the main stream water pressure to the design level then discharges it via discharge line 91, to the heat exchanger section of regenerator 93, where it picks up more heat energy before finally being passed to the gas generator subsystem 200, and the reheaters 62 and 63, in the power turbine subsystem 300, via discharge line 8, and reheater cooling water line 65. The feed water pumps 16a, 16band 16c are powered by the common drive unit 9.
FIG. 2. Power Generation System with Regenerators
FIG. 2 illustrates a non-polluting electrical energy generating plant 2000, comprising a reactant induction subsystem 100, a gas generation subsystem 200, a turbine drive subsystem 300, an electrical energy generation subsystem 400, an exhaust management subsystem 500, and a regenerated water management subsystem 600.
The reactant service subsystem 100 feeds and controls the flow of the fuel and oxidizer reactants that power this system. This includes a liquid oxygen (LOX) feed line 1, feeding the LOX pump 2, which is powered by drive unit 6. The LOX pump 2 delivers high pressure LOX to the system gas generator subsystem 200, via the discharge line 3. High pressure gaseous or liquid fuel is delivered to the gas generator subsystem 200 through feed line 4.
The drive gas generator subsystem 200 includes a gas generator 7, which efficiently combusts the injected reactants under controlled conditions, producing a high pressure, high temperature gaseous mixture of steam and carbon dioxide which is delivered as a turbine drive gas. The drive gas is delivered to the turbine drive subsystem 300, via discharge line 10. Thermal control of the combustion process can be accomplished by controlling cooling water flow rate to the gas mixing chamber and to the chamber structure via water feed lines 64, supplied by water service feed line 65, which also feeds cooling water to the gas generator subsystem 200, from the water management subsystem 600.
The unreheated turbine drive subsystem 300, converts the gas generator subsystem 200 output energy into mechanical energy to drive the electrical generator subsystem 400. The turbine subsystem consists of three power turbines, pressure staged for optimum efficiency.
The turbine drive subsystem 300 consists of high pressure power turbine 13, high pressure power turbine exhaust line 11, and high pressure power tap-off line 45. This assembly is followed by a medium pressure power turbine 14, medium pressure power turbine discharge line 12, and medium power turbine tap-off line 15. The turbine power subsystem 300 is terminated by a low pressure power turbine 17, and discharge line 25, which sends the gas flow to an exhaust recovery condenser 41, in the exhaust recovery subsystem 500.
The energy generation subsystem 400 is the electrical energy conversion facility 18, consisting of electrical generator(s), and power conditioning, which develop the end product of this plant, electrical energy.
The exhaust management subsystem 500 is a gas handling subsystem with two purposes: (i) to make the most efficient use of the exhaust products, and (ii) to verify that pollution controls are effective. This subsystem consists of a carbon dioxide recovery branch and a water recovery branch, both serviced by heat rejection facility 30.
The carbon dioxide recovery assembly receives near ambient temperature, gaseous carbon dioxide (CO2) from the condenser 41, via discharge line 19, and from the water management subsystem 600, via regenerator 46 CO2 gas discharge lines 47, into compressor 20, which is powered by drive unit 21. After a stage of compression, the gas is delivered to a water cooled heat exchanger in cooler unit 26, via discharge line 23. After cooling by passage through the cooler vessel 26, the fluid is returned to the compressor 20, via return line 24, and further compressed before discharge to facility return line 5, for recovery processing. Cooling water is supplied to the cooler 26, from the heat rejection facility 30, by cooling water pump 34, powered by drive unit 36. Cooling water is drawn through inlet line 33, and delivered through pump discharge line 31, and cooler inlet line 28. After passing through the heat exchanger element in cooler 26, the cooling water is returned to the heat rejection facility 30, via discharge line 29. Carbon dioxide is also recovered from preheater 93 via discharge line 94.
The water recovery branch consists of the condenser vessel 41, cooling water inlet line 27, which sends cooling water through the condenser 41 heat exchanger section to cool down and condense the exhausted steam back to water. The cooling water is then returned to the heat rejection facility 30, via cooling water outlet line 22, and the condensed water is returned to the water management subsystem 600, via discharge line 37.
The water management subsystem 600 maintains the proper water balance in the operating system 2000. It does this by maintaining the proper cooling water injected at the gas generator inlet. The major product of combustion, using the reactants intended for this system, is water, therefore following start-up there is more than enough water available to operate the system. However, to insure adequate water availability during start-up, shut-down, and other transient operations, the heat rejection facility will serve as a reservoir as well as a receiver for any excess water generated. The main elements in the embodiment of the water management subsystem 600 are pressure staged pumps 16a, 16b, and 16c, driven commonly by drive unit 9, two (2) performance enhancing regenerator units 46 and 93, and a condensate pump 38, powered by drive unit 39.
The water recovered in the exhaust management subsystem 500 is returned to the water supply from condenser 41, via discharge line 37, to condensate water pump 38, which is powered by drive unit 39. Condensate water pump 38 delivers the water to the feed water pumping system via discharge line 40. Excess water is diverted to the heat rejection facility 30, via return line 35, or any required start-up or make-up water is drawn from the heat rejection facility 30, via inlet line 95 and delivered to the inlet of water pump 16a. The main water flow is delivered to the feed water pumps 16a, 16b and 16c by the condensate pump 38, via feed line 43, which is joined by a recirculated flow from the medium pressure turbine tap-off line 15. This tap-off flow serves as the heat source in the heat exchange element of regenerator 46, to conserve heat energy. The tap-off flow is collected in a sump in regenerator 46, and discharges to the low pressure feed water pump 16a, via discharge line 48, of regenerator. 46 and pump 16a inlet line 43. An initial stage of feed water pressurization is accomplished in low pressure feed water pump 16a. The outflow of pump 16a is carried to regenerator 46, via discharge line 49, picks up heat energy in the heat exchanger element in regenerator 46, and then is passed to the medium pressure feed water pump 16b, via regenerator 46 discharge line 50, through inlet line 51. The water flow is joined by a recirculated flow that originates from the high pressure power turbine tap-off line 45. This tap-off flow serves as the heat source in the heat exchange element of the regenerator 93, to further conserve heat energy. The tap-off flow is collected in a sump in regenerator 93, and discharges to the medium pressure feed water pump 16b, via sump discharge line 92, of regenerator 93, and through medium pressure pump inlet line 51. The feed water flow stream is passed to the high pressure pump 16c, via medium pressure feed water pump 16b's discharge line 90. The high pressure pump 16c raises the main stream water pressure to the design level then discharges it via discharge line 91, to the heat exchanger section of regenerator 93, where it picks up more heat energy before finally being passed to the gas generator subsystem 200, via discharge line 8, and cooling water lines 64 and 65. The feed water pumps 16a, 16b and 16c are powered by the common drive unit 9.
FIG. 3. Baseline Power Generation System
FIG. 3 illustrates a non-polluting, efficient electrical energy generating power plant 3000, comprising a reactant induction subsystem 100, a gas generation subsystem 200, a turbine drive subsystem 300, an electrical energy generation subsystem 400, an exhaust management subsystem 500, and an unregenerated water management subsystem 600.
The reactant service subsystem 100 feeds and controls the flow of the fuel and oxidizer reactants that power this system. This includes a liquid oxygen (LOX) feed line 1, feeding the LOX pump 2, which is powered by drive unit 6. The LOX pump 2 delivers high pressure LOX to the system gas generator subsystem 200, via the discharge line 3. High pressure gaseous or liquid fuel is delivered to the gas generator subsystem 200 through feed line 4.
The drive gas generator subsystem 200 includes a gas generator 7, which efficiently combusts the injected reactants under controlled conditions, producing a high pressure, high temperature gaseous mixture of steam and carbon dioxide which is delivered as a turbine drive gas. The drive gas is delivered to the turbine drive subsystem 300, via discharge line 10. Thermal control of the combustion process can be accomplished by controlling cooling water flow rate to the gas mixing chamber and to the chamber structure via water feed lines 64 and 65, from the water management subsystem 600.
The turbine drive subsystem 300, converts the gas generator subsystem 200 output energy into mechanical energy to drive the electrical generator subsystem 400.
The turbine subsystem consists of three power turbines, pressure staged for optimum efficiency. The turbine drive subsystem 300 consists of high pressure power turbine 13, and high pressure power turbine exhaust line 11. This assembly is followed by a medium pressure power turbine 14, and medium pressure power turbine discharge line 12. The turbine power subsystem 300 is terminated by a low pressure power turbine 17, and discharge line 25, which sends the gas flow to an exhaust recovery condenser 41, in the exhaust recovery subsystem 500.
The energy generation subsystem 400 is the electrical energy conversion facility 18, consisting of electrical generator(s), and power conditioning, which develop the end product of this plant, electrical energy.
The exhaust management subsystem 500 is a gas handling subsystem with two purposes: (i) to make the most efficient use of the exhaust products, and (ii) to verify that pollution controls are effective. This subsystem consists of a carbon dioxide recovery branch and a water recovery branch, both serviced by a heat rejection facility 30.
The carbon dioxide recovery assembly receives near ambient temperature, gaseous carbon dioxide (CO2) from condenser 41, via discharge line 19, into compressor 20, which is powered by drive unit 21. After one stage of compression, the gas is delivered to a water cooled heat exchanger in cooler unit 26, via discharge line 23. After cooling by passage through the cooler vessel 26, the fluid is returned to the compressor 20, via return line 24, and further compressed before discharge to facility return line 5, for recovery processing. Cooling water is supplied to the cooler 26, from the heat rejection facility 30, by cooling water pump 34, powered by drive unit 36. Cooling water is drawn through inlet line 33, and delivered through pump discharge line 31, and cooler inlet line 28. After passing through the heat exchanger element in cooler 26, the cooling water is returned to the heat rejection facility 30, via discharge line 29.
The water recovery branch consists of the condenser vessel 41, cooling water inlet line 27, which sends cooling water through the condenser 41 heat exchanger section to cool down and condense the exhausted steam back to water. The cooling water is then returned to the heat rejection facility 30, via cooling water outlet line 22, and the condensed water is returned to the water management subsystem 600, via discharge line 37.
The water management subsystem 600 maintains the proper water balance in the operating system 3000. It does this by maintaining the proper cooling water injected at the gas generator inlet. The major product of combustion, using the reactants intended for this system, is water, therefore following start-up there is more than enough water available to operate the system. However, to insure adequate water availability during start-up, shut-down, and other transient operations, the heat rejection facility will serve as a reservoir as well as a receiver for any excess water generated. The main elements in the embodiment of the water management subsystem 600 are pressure staged pumps 16a, 16b, and 16c, powered commonly by drive unit 9, and a condensate pump 38, driven by drive unit 39.
The water recovered in the exhaust management subsystem 500 is returned to the system water supply from condenser 41, discharge line 37, to condensate water pump 38, which is powered by drive unit 39. Condensate water pump 38 delivers the water to the feed water pumping system via discharge line 40. Excess water is diverted to the heat rejection facility 30, via return line 35, or any required start-up or make-up water is drawn from the heat rejection facility 30, via inlet line 95 and delivered to the inlet of water pump 16a. The main water flow is delivered to feed water pumps 16a, 16b and 16c. The condensate pump 38, sends the recovered water to the low pressure feed water pump 16a, via feed line 43. Initial feed water pressurization is accomplished in low pressure feed water pump 16a. The outflow of pump 16a is carried to medium pressure feed water pump 16b by feed water line 49. The medium pressure feed water pump 16b raises the feed water pressure further and passes the feed water flow stream to the high pressure pump 16c, via feed water line 90. The high pressure pump 16c raises the main stream water pressure to the design level before finally being passed to the gas generator subsystem 200 via discharge line 8 and inlet water lines 64 and 65.
FIG. 4. Simplified Power Generation System
FIG. 4 illustrates a minimum polluting, efficient electrical energy generating power plant 4000, comprising a reactant induction subsystem 100, a gas generation subsystem 200, a turbine drive subsystem 300, an electrical energy generation subsystem 400, and a limited water management subsystem 600. The limited exhaust gas management subsystem 500 is eliminated in this embodiment. This embodiment has a reduced complexity, hence reduced costs, for both acquisition and maintenance.
The reactant service subsystem 100 feeds and controls the flow of the fuel and oxidizer reactants that power this system. This includes a liquid oxygen (LOX) feed line 1, feeding the LOX pump 2, which is powered by drive unit 6. The LOX pump 2 delivers high pressure LOX to the system gas generator subsystem 200, via the discharge line 3. High pressure gaseous or liquid fuel is delivered to the gas generator subsystem 200 through feed line 4.
The drive gas generator subsystem 200 includes a gas generator 7, which efficiently combusts the injected reactants under controlled conditions, producing a high pressure, high temperature gaseous mixture of steam and carbon dioxide which is delivered as a turbine drive gas. The drive gas is delivered to the turbine drive subsystem 300, via discharge line 10. Thermal control of the combustion process can be accomplished by controlling cooling water flow rate to the gas mixing chamber and to the chamber structure via water feed lines 64 and 65. This embodiment is suited for sites where water availability makes the complexity and cost of a water recovery system unnecessary.
The turbine drive subsystem 300, converts the gas generator subsystem 200 output energy into mechanical energy to drive the electrical generator subsystem 400. The turbine subsystem consists of three power turbines, pressure staged for optimum efficiency.
The turbine drive subsystem 300 consists of high pressure power turbine 13, and high pressure power turbine exhaust line 11. This assembly is followed by a medium pressure power turbine 14, and medium pressure power turbine discharge line 12. The turbine power subsystem 300 is terminated by a low pressure power turbine 17, and discharge line 25, which discharges the exhaust to the atmosphere.
The energy generation subsystem 400 is the electrical energy conversion facility 18, consisting of electrical generator(s), and power conditioning, which develop the end product of this plant, electrical energy.
In this embodiment the exhaust management subsystem 500 is deleted and the low pressure turbine exhaust gases are vented to the atmosphere.
For this embodiment the water management subsystem 600 draws cooling water from a nearby water source. The main elements in this embodiment of water management subsystem 600 are pressure staged pumps 16a, 16b, and 16c, powered commonly by drive unit 9. The water flow is drawn by the feed water pumps 16a, 16b, and 16c, through intake line 43. The initial stage of feed water pressurization is accomplished in low pressure feed pump 16a. The out-flow of pump 16a is carried via discharge line 49, to the medium pressure feed water pump 16b. From medium pressure feed pump 16b, the feed water flow stream is passed to the high pressure pump 16c, via medium pressure feed water pump 16b's discharge line 90. The high pressure pump 16c raises the main stream water pressure to its design level and delivers the water to the gas generator subsystem 200 via discharge line 8 and cooling water lines 64 and 65.
FIG. 5. High Pressure Steam/CO2Generation System
FIG. 5 illustrates a non-polluting, high energy industrial fluid generation plant 5000, comprising a reactant service subsystem 700, and a gas generation subsystem 200.
The reactant service subsystem 700 feeds and controls the flow of fuel and oxidizer reactants that power this system. This includes a liquid oxygen inlet line 1, feeding a high pressure LOX pump 2, driven by drive unit 6. The LOX pump 2, delivers high pressure LOX to the gas generator subsystem 200, via the pump discharge line 3. Inlet line 80 feeds liquid fuel to high pressure pump 81, which is powered by drive unit 82. Pump 81 delivers high pressure fuel to the gas generator subsystem 200 via discharge line 4. Inlet line 43 delivers cooling feed water to the high pressure pump 16, which is powered by drive unit 9. The high pressure cooling water is delivered to the gas generator subsystem 200 via pump discharge line 8. This flow is split at line 8 outlet into cooling water for delivery to the gas generator 200's internal combustor chamber cooling via feed line 64, and to the internal gas-water mixing chamber section via inlet line 65.
The drive gas generator subsystem 200 includes a gas generator 7, Which combusts the injected reactants under controlled conditions, producing a high pressure, high temperature gaseous mixture of steam and-carbon dioxide, a high energy fluid suitable for a wide range of industrial applications, via discharge line 10. Thermal control of the combustion process is accomplished by controlling cooling water flow rate to an internal combustion chamber and to the gas-water mixing chamber via water feed lines 64 and 65.
FIG. 6. Auxiliary/Transportation Power Generation System
FIG. 6 illustrates a non-polluting, efficient, auxiliary and/or transportation power system 6000. This embodiment augments embodiment 5000, subsystems 700 and 200 with an energy conversion subsystem 900, to produce a power system that can be scaled in size to a wide spectrum of industrial applications (e.g's., stand-by emergency power, peaking power, portable remote site power, nonpolluting steam train power, ocean-going vessels, and many other similar applications).
The reactant service subsystem 700 feeds and controls the flow of fuel and oxidizer reactants that power this system and the gas generator subsystem 200 cooling water. This includes a liquid oxygen inlet line 1, feeding a high pressure LOX pump 2, which is driven by drive unit 6. The LOX pump 2 delivers high pressure LOX to the gas generator subsystem 200, via the pump discharge line 3. Inlet line 80 feeds liquid fuel to high pressure pump 81, which is powered by drive unit 82. Pump 81 delivers high pressure fuel to the gas generator subsystem 200 via discharge line 4. Inlet line 43 delivers cooling feed water to the high pressure pump 16, which is powered by drive unit 9. The high pressure cooling water is delivered to the gas generator subsystem 200 via pump discharge line 8.
The drive gas generator subsystem 200 includes a gas generator 7, which combusts the injected reactants under controlled conditions, producing a high pressure, high temperature gaseous mixture of steam and carbon dioxide, a high energy drive fluid delivered to the drive turbine 17, of the energy generation subsystem 900, via discharge line 10. Thermal control is accomplished by controlling cooling water flow rate picked up from discharge line 8 of the reactant service subsystem 700. This flow stream is split and directed to an internal combustion chamber via inlet line 64, and to the main mixing chamber section via water inlet line 65.
The energy generation subsystem 900 is the electrical energy conversion facility power turbine 17, and the electric motor/generator unit 18, which can be harnessed to any number of industrial applications.
FIG. 7. Gas Generator
FIG. 7 is a cut-away view of a unique, advanced technology combustor device which is the gas generator 7 used to develop the high energy gas used in all the embodiments contained in this application. Its configuration and operation are designed to develop and control the high energy, non-polluting fluid in the most efficient, cost-effective manner. The thermo-mechanical design and physical conformation are specific features the purposes of which are efficient operation, pollution avoidance, long life and minimum maintenance.
The device is composed of a start-up igniter 210, a fluid induction head 201, containing oxygen and gaseous or liquid fuel inlets on a planar face therof and integral distribution channels, the induction head providing the inspiration of fuel and oxygen into the gas generator an injector face water cooling inlet and distribution circuitry, a micro-ported reactant injector body, and a water cooled combustor. The fluid induction head interfaces with an adapter block 202 which contains an inlet and distribution passages to feed cooling water to the wall of the combustor element of the fluid induction head. The adapter block 202 includes a hollow cylindrical shroud having a central axis aligned perpendicular to the planar side of the induction head 201. The cylindrical shroud has a first end adjacent to the induction head 201 and a second end opposite the first end, the second end located free from contact with the walls of the enclosure. The shroud includes a hollow interior and an exterior surface facing away from the hollow interior. The oxygen and fuel inlets are located within the hollow interior. The cooling water inlets are located outside of the of the hollow interior and adjacent the exterior surface of the shroud. The second end of the shroud has tapered throat having a diameter less than a diameter of the tint end of the cylindrical shroud. The adapter block 202 is also the interface to the device mixing chamber 203. The mixing chamber has inlets for the induction of the major portion of the water flow which mixes with the hot gas in the chamber to attain the design drive gas temperature. In addition, the manner in which this flow stream is introduced cools the walls of the mixing chamber, maintaining wall temperature at the design level. The gas generator is comprised of: a means of start-up ignition, using an electrical device to ignite a combustible mixture in a chamber, a means of receiving high pressure liquid oxygen, means for receiving high pressure gaseous or liquid hydrocarbon or simple alcohol fuel, and means for combining said high pressure liquid oxygen and said high pressure gaseous or liquid fuel in a chamber for combustion, including inlet means for said oxygen and said fuel, distribution means for said oxygen and said fuel, a means for metering and mixing said oxygen and said fuel to obtain complete combustion, means of containing the combusted gases in a controlled flow which is treatable, and means of exhaust; a means of introducing into the chamber, a high pressure water flow to cool the chamber walls and to quench the combusted gases being exhausted, including water inlet means, water distribution means, water and gas mixing means, and means for exhaust of a high pressure, high temperature working fluid.
FIG. 8. Drive Gas Reheater
FIG. 8 is a cut-away view of a unique, advanced technology drive gas reheater 62 63 which can be used to boost the temperature of a drive gas stream after it has passed through an energy extracting device like a power turbine. While this approach to energy management in a power system has a small penalty in overall system efficiency, it allows a reduction in the size and weight of certain components. The thermo-mechanical design and physical conformation are specific features, the purposes of which are efficient operation, long life and minimal maintenance.
The device is composed of the same start-up igniter 40 used in the gas generator, FIG. 7, a fluid management head 201 containing oxygen and fuel inlets and integral distribution channels, an injector face water cooling inlet and distribution circuitry, a micro-ported reactant injector body, and a water cooled combustor. This item is the same as item 202 in the gas generator in FIG. 7. The fluid induction head interfaces with an adapter block 204 which contains an inlet and distribution passages to feed cooling water to the wall of the combustor element of the fluid induction head 201. The adapter block 204 is similarly configured to item 201 in the gas generator device in FIG. 7, except that the outer flange diameter is sized to interface with the gas induction and mixing chamber 205. The mixing chamber has inlets for the induction of the gas flow from the preceding device (e.g., preceding turbine exhaust) and to mix the inducted gas with the hot gas generated in the preheater combustor in item 204. This mixing is done to raise the inducted gas temperature back to the same level it had at the entrance of the preceding device. This element is similar to that in FIG. 7, except that its fore and aft diameters are matched to the preceding and following devices in the total gas flow path, and the inlets induct gas rather than water and are sized accordingly. | Five embodiments of Pollution-Free, Efficient, Large Scale Electrical Power Generation Systems, using thermal energy are illustrated herein. Each embodiment is composed of subsystems and/or individual elements which tailor each system to an operating environment that requires different implementation modes or applications.
Also illustrated are two embodiments configured to adapt smaller scale power plants to applications such as platform mounted portable power applications, large vehicle propulsion, and other applications.
Also illustrated is an embodiment configured to produce high quality fluid at controlled pressures and temperatures as required by a wide range of industrial applications. | 8 |
BACKGROUND OF THE DISCLOSURE
The present disclosure is directed to a protective device which protects wireline supporting logging tools from breaking the wireline by excessive pulling on the wireline. It is used in circumstances in which snagging of the cable supported load might accidentally break the cable and risk loss of the cable supported sonde.
Assume that a well has been drilled to a specified depth and has an uncased portion. In that region, there are areas where a protruding, irregular formation in the borehole may snag the logging cable or tool supported thereby. In addition, the tool may be supported on a coil tubing for lowering or raising the well borehole. Ordinarily, this occurs during raising of the tool in the borehole where the logging cable is maintained in tension. Snagging may increase the tension on the cable and thereby break the cable, dropping the logging tool and requiring an expensive fishing job to retrieve the sonde. Of course, the cable will have to be repaired also.
Assume for purposes of illustration that the logging cable is to support a first tool and then what tool is switched, and a second tool is installed. The tools may not weigh the same. Assume for descriptive purposes that one tool weights 200 pounds while the other tool weights 400 pounds. When weight variations are encountered the loading on the cable is different. The present apparatus is a overload protection device which guards against overloading the cable notwithstanding changes in the weight of the sonde affixed to the cable. The present apparatus is a device which connects between the cable and the sonde and which is adjustable to accommodate variations in tool weight as exemplified above, and relates that ability while also providing an adjustable range of loading imparted to the cable resulting from snagging. Assume for purposes of discussion that the cable can tolerate additional loading of 200 pounds above the weight of the tool. In that event, the tool when snagged can be pulled free provided the cable tension does not exceed 600 pounds with a 400 pound tool. If the load is greater than 600 pounds, damage might result. It is difficult to measure cable stress solely by what occurs at the surface. At the surface, the operator is normally equipped with a cable spool or drum with a motor (usually hydraulic) which rotates that spool at a specified rate. The surface located sheave is supported by a load cell monitored structure which cell output is normally indicative of cable tension. However, that is misleading becasue cable tension at the surface is not the same as cable tension at the tool in the borehole. When a cable is broken, it often occurs at the sheave. That is, the cable typically is broken somewhere between the ends. Normally, the cable connector is made to be the weak link in the connective equipment because separation at the cable connector is preferable to parting the cable. When the tool is snagged and held a short moment during retrieval, the cable might break at the sonde where separation is desirable.
The present apparatus is a cable head permitting connection of the cable to the sonde and which provides a signal when axial loads on the cable become excessive. This cable load value is adjustable to accommodate an adjustale peak load setting for snagging and is also adjustable to take into account changes in sonde weight. These adjustments enable a system to be devised which forms an output signal indicative of exceeding an adjustable but specified cable load. This signal is relayed to the surface and permits the operator to reduce cable tension, and thereby protects the cable, sonde and connective cable head therebetween from rupture in the event of excessive pull.
The output of the device is a signal on an electrical conductor through the device which conductor extends along the logging cable to furnish a surface output signal for the operator.
BRIEF DESCRIPTION OF THE DRAWINGS
So that the manner in which the above recited features, advantages and objects of the present invention are attained and can be understood in detail, more particular description of the invention, briefly summarized above, may be had by reference to the embodiments thereof which are illustrated in the appended drawings.
It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
FIG. 1 is a sectional view taken through the length of the cable head of the present disclosure and further illustrating a means for adjusting the permitted cable load acting on the cable head;
FIG. 2 is a sectional view taken through the apparatus of FIG. 1 illustrating the rotational position of certain components accommodating an adjustment in load; and
FIG. 3 is a view of shoulder steps on the exterior of a cylindrical component partly shown in FIGS. 1 and 2 wherein an adjustment is made for changes in sensitivity.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Attention is directed to FIG. 1 of the drawings where the numeral 10 identified a cable head connector in accordance with the teachings of the present disclosure. At the top end, it connects with a threaded fitting at the end of a logging cable. An alternate to the cable is a coiled tubing supporting the sonde. At the bottom end, it connects with a mating fitting on a sonde. The cable head 10 is an adjustable tension device which provides an output indication that tension is within a specified range; perhaps better stated, it provides an indication that the axial force is outside an accepted range.
The upper end of the equipment includes a threaded sub 11 having internal threads and is adapted to connect with the lower end of the cable. The cable is provided with at least one electrical conductor which connects through a conventional fitting 12 which is internally recessed and surrounded by the sub to be protected from contact with the fluid that is typically in the borehole. The connector includes a feedthrough 13 positioned in telescoping relationship to a circular profiled cam 14 to be described in detail below. The connector 12 provides electrical connection, and in that sense, the feedthrough 13 and telescoped cam 14 are hot, meaning that they are wired for current conduction.
The sub 11 is threaded to an outer sleeve 15, and leakage along that connection is prevented by a seal 16 therebetween. The sleeve 15 is a load bearing member. It supports the load inparted to the exterior of the cable head 10, while the interior components telescope relative to the sleeve 15. A support sleeve 17 is threaded to the interior of the sleeve 15. It is formed with an axial passage therethrough. It threads on the exterior and is held in a fixed position in the sleeve 15. The sleeve 15 supports the sleeve 17 at a certain oriented position as shown in FIG. 2 of the drawings. The sleeve 17 supports an internally protruding rib 18 which is incorporated for registration purposes. The rib 18 extends along the internal axial passage. This rib has a facing shoulder which abuts an alignment pin 19. The pin 19 is made of nonconducting materials for reasons to be described. It serves as a stop or limit preventing rotation in one direction where the pin 19 is constrained by the facing rib 18.
The cam 14 has a stepped recess cut in the exterior cylindrical face. This recess is better shown in FIG. 3 of the drawings. The recess has a uniform depth around the cylindrical outer surface of the cam 14, and is defined by upper and lower facing shoulders shown in FIG. 3. The upper shoulder 20 faces the lower shoulder 21. As shown in FIG. 3 of the drawings, they are formed with a series of steps. Each step encompasses 45 degrees of cam rotation. The steps are opposite one another, and have variable spacing between pairs of steps. The closest pair of steps is identified at 22. That pair of steps inscribes a certain spacing. The spacing increases from step to step in a uniform fashion. The eight steps thus comprise eight wider spacings.
The steps are adapted to bracket the radially inwardly directed contact 24 shown in FIG. 1. This contact has a length which enables it to extend into the recess without contact. However, on movement upwardly or downwardly of the cam 14, the contact 24 is brought into grounding contact with either the upper or lower steps. As viewed in FIG. 3, the contact travels along a locus which ideally (in the neutral position) is centered between facing steps. This eight step range of movement for the contact 24 relative to the facing shoulders 20 and 21 in stepwide fashion will be discussed in detail hereinafter.
Returning now to FIG. 1 of the drawings, an insulated conductor 25 is positioned to connect with the feedthrough 13 and telescope therewith. The insulated conductor 25 extends therethrough and terminates at a suitable feedthrough 26 at the lower end of the tool. This enables the conductor to extend into the affixed sonde through a mating feedthrough terminal 27. More importantly, the surrounding sleeve 15 is used as an electrical ground while a signal voltage is placed on the conductor 25 and on the feedthrough 13. This places a signal voltage on the cam 14 which is ultimately positioned opposite the contact 24 for grounding purposes. The contact 24 is affixed to the lower end of the stationary sleeve 17. That contact is maintained at ground potential; contact grounds the cam 14 and forms a signal through the feedthrough 13 and the connected electrical conductor. The function of this will be described in detail hereinafter.
The region around the contact 24 is operated in an oil bath. It is preferably filled with nonconductive oil. The oil is maintained in this region by a piston 30 which defines an oil filled chamber 31 thereabove, and a chamber 32 below which is exposed to drilling fluid. Pressure equalization is accomplished by movement of the piston 30. Moreover, the piston 30 rides on a moveable stem 34 which telescopes in the sleeve 15 and rides up and down with movement. The stem 34 extends below and supports an enlarged mandrel 35. The mandrel is telescoped within the sleeve 15 to the lower end of the sleeve. The mandrel is used to align several springs as will be described.
The sleeve 15 is constructed with an upper set of slots 36. There is a central solid ring 37 integral with sleeve 15 at the lower end of the slots, and that in turn connects with an inwardly directed shoulder 38. The shoulder extends to the interior and encircles the mandrel 35. The shoulder 38 separates the interior compartment for a lower spring 50 from that for an upper spring 48. The solid circular ring 37 is above a middle set of slots 39. These slots are similar to a lower et of slots 40 at the very bottom of the tool. A guide pin 41 is located to extend into the slots 40 and serves as an indexing mechanism to be described.
Preferably, there are eight slots 40 distributed circumferentially around sleeve 15 lower end. The slots 40 are preferably equal in number to the steps shown in FIG. 3 for the shoulders 20 and 21; since there are eight steps, it is preferable to have eight corresponding slots. They serve as a registration mechanism to align the components. The mandrel 35 extends downwardly and connects with a threaded sub 44. The sub is axially hollow and provided with internal threads for joinder to the mandrel 35. Moreover, it is hollow and has a passage for the conductor 25 previously identified. The conductor 25 extends to the lower end of the sub at teh feedthrough 27. Moreover, the sub is provided with a set of threads 45 for easy connection to the sonde which is anchored therebelow. It is hollow so that the feedthrough 27 is permitted to connect to equipment therebelow.
The sub 44 supports the indexing pin 41. Through telescoping movement by relative upward movement of the sleeve 15 and associated rotation, the pin 41 removed from the eight slots 40 and realigned with a different slot and the telescoped parts are restored to the operative position shown in FIG. 1. When this occurs, the relative clearance above and below the contact 24 between the facing shoulders 20 and 21 is changed. It is moved from one pair of facing shoulder steps to another pair of steps. This changes the sensitivity of the device. More will be noted concerning this hereinafter.
The radially directed shoulder 38 extends inwardly to the mandrel 35. This defines upper and lower spring receiving spaces of annular construction. The spring stacks 48 and 50 are referably defined by Belleville washers in the illustrated fashion. This defines a high performance, high quality spring system which centers the transverse shoulder 38. Moreover, the two springs will force the telescoping parts to a centered position. Consider for the moment the spring system when an imbalanced force is achieved. When that occurs, the mandrel 35 is forced upwardly or downwardly as the case may be and when it moves, it moves the cam 14 which is fixedly connected to the stem 34. This motion readjusts the location of the contact 24 between the facing shoulders 20 and 21. If contact is made, a signal is then formed and relayed through the electrical conductor that contact has occurred. This contact is a signal that movement to one extreme or the other has occurred. Movement of the contact 24 relative to the two spring systems 48 and 50 will be more apparent on a description of operation found below.
Use of the cable head 10 of the present disclosure will be more clear on the following example. The sleeve 17 is relatively raised or lowered by rotation of the sub 44 to position the contact 24 at a central or neutral position. It is centered relative to the shoulders 20 and 21 which bracket the contact 24. Sensitivity or the range of travel permitted is then obtained by movement of the pins 41 which indexes one of the eight slots 40. That is achieved while rotating the sub 44 after temporary removal of the pins 41. As the sub 44 rotates, this motion is imparted to sleeve 17 via mandrel 35 and the interaction of rib 18 and alignment pin 19. In less than one revolution of mandrel 35 in either direction, the interaction of the rib 18 and alignment pin 19 imparts the motion of the mandrel 35 to the sleeve 17 thereby adjusting its position along the threaded connection between sleeve 17 and outer sleeve 15. After sub 44 rotation, the pin 41 is then repositioned in a selected slot. Thus, the contact 24 can be tightly confined by the closest pair of steps or can be widely spaced by the most broadly spaced steps. In any event, this position is achieved. As a generalization, the close steps 22 permit the smallest range of travel. This is associated with minimal snagging. In other words, minimal axial travel is permitted should the sonde snag in the borehole. Excessive travel results in electrical contact, and a signal is provided that excessive travel has occurred. By contrast, if wider spacing between the shoulders 20 and 21 is aligned with the contact 24, the sensitivity is reduced and a greater range of travel is tolerated.
The foregoing describes operation of the contact 24 facing the two surrounding shoulders. The position of the contact 24 along the centered position between shoulders 20 and 21 is subject to the springs 48 and 50. The two stacks of spring members are adjusted so that they counteract one another subject to sonde weight. Assume for discussion that the system is installed on a sonde having a specified weight, and then the weight of the sonde is changed. Assume that the present apparatus is connected first to a 200 pound sonde and then switched to a 400 pound sonde. This compresses the upper spring 48, making it shorter. This pulls the cam 14 lower with respect to the contact 24. Readjustment moves the contact 24 centerline by repositioning the sleeve 17. Repositioning and changing of sensitivity involves threading the sub 44 and indexing repositioning of the pin 41 relative to the slots 40. Consequently, the two adjustments are made after the weight change has been implemented. This can be accomplished at the surface before placing the tool in the borehole.
Telescoping movement which does not cause grounding contact is absorbed in the system. The feedthrough 13 telescopes relative to the connected cylindrical cam 14 and in turn, the electrical conductor continues through the cable head 10. Moreover, such movement can be vibratory of chattering as the sonde encounters periodic bumps during upward travel in the borehole. The springs 48 and 50 provide a balancing and centering force, restoring the equipment to the centered position. Centering particularly refers to the position of the contact 24 between steps of the upper and lower shoulders 20 and 21 respectively.
Each use of the present instrument can be adjusted. That is, when the sonde has been retrieved to the surface, the sensivity of the instrument can be adjusted, and the centering can be readjusted in light of changes of the weight of the sonde. That also is subject to variation dependent on the circumstances in which the cable head 10 is installed. The term cable used in the claims refers to a woven cable, cable with one or more conductors, coiled tubing and the like.
While the foregoing is directed to the preferred embodiment, the scope thereof is determined by the claims which follow. | A logging tool cable head for supporting the sonde on a cable is disclosed. It has an upper end which affixes to the cable and a lower end affixed to the sonde. The lower end supports an inwardly directed electrical grounding contact. The upper end supports a rotatable, indexed cam having facing upper and lower shoulders sized and located to bear against the contact, so that electrical contact is indicated on overloading. Indexing of the shoulders relative to the contact is achieved. There is also an adjustable centering spring system which locates the contact relative to the two shoulders. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Some of the aspects of the methods and systems described herein have been described in U.S. Provisional Application Nos. 61/780,408 entitled “Systems And Methods To Synchronize Data To A Mobile Device Based On A Device Usage Context”, filed Mar. 13, 2013; 61/781,252 entitled “Systems And Methods To Secure Short-Range Proximity Signals”, filed Mar. 14, 2013; 61/781,509 entitled “Systems And Methods For Securing And Locating Computing Devices”, filed Mar. 14, 2013; 61/779,931 entitled “Systems And Methods For Securing The Boot Process Of A Device Using Credentials Stored On An Authentication Token”, filed Mar. 13, 2013; 61/790,728 entitled “Systems And Methods For Enforcing Security In Mobile Computing”, filed Mar. 15, 2013; and U.S. Non-Provisional application Ser. No. 13/735,885 entitled “Systems and Methods for Enforcing Security in Mobile Computing”, filed Jan. 7, 2013, each of which is hereby incorporated by reference herein in its entirety.
BACKGROUND OF THE INVENTION
[0002] The present invention is in the technical field of computer security. More particularly, the present invention is in the technical field of identifying a computing device and/or the user of such a device using credentials stored on an authentication token and/or based on the location of the computing device.
SUMMARY OF THE INVENTION
[0003] As mobile devices, such as smartphones and tablet computers, become more powerful and ubiquitous, it becomes advantageous to use them for an increasing number of applications. In some instances, these applications may require that sensitive information be stored in nonvolatile memory on the device. It is therefore important to be able to protect said information stored on the device both while the device is running and while the device is powered off. Securing a device may include authenticating a user's credentials.
[0004] An additional element of security may be added based on the location of the device. For example, a user of a device may be able to authenticate on the device, but may not get access to certain files unless the device is in a certain location. Similarly, a user may be able to authenticate on the device, but may be prohibited from accessing certain applications while in a certain location (e.g. prohibited from texting while in a car).
[0005] Embodiments provide a plurality of beacons in the environment, wherein each beacon emits a localization signal. A system receives data derived from a localization signal from a user device and determines the initial location of a user device within the environment based on the localization signal. A plurality of devices are also located within the environment, each of which may provide user interaction. A first user interaction is provided via a first device, where the first device is selected from the plurality based on an initial location of the user device. An updated location of the user device is determined, and a second user interaction is provided via a second device, where the second device is selected from the plurality based on the updated location of the user device. Embodiments also operate by providing multiple user devices, each of which emits and receives localization signals. Each device may include a display, a receiver, and an emitter. At least some devices also include a modification system which modifies the display of the device based on localization signals received from other devices.
[0006] Tracking user devices may also enable additional applications for the user devices. For example, location information may be used for gathering input for customer analytics, enabling the user devices to behave as universal remotes, and enhancing multiplayer games.
BRIEF DESCRIPTION OF THE FIGURES
[0007] FIG. 1 depicts certain components of a system that may be utilized in providing a secure device.
[0008] FIG. 2 depicts a workflow for securing a computing system based on the presence of users of a group of users.
[0009] FIG. 3 depicts a workflow for securing a computing system based on a user authenticated on a computing device in proximity to the computing system.
[0010] FIG. 4 depicts a workflow for securing a device.
[0011] FIG. 5 depicts a workflow for identifying the location of a computing device.
DETAILED DESCRIPTION
[0012] A platform for tracking the location of a user device may be useful for enhancing the security of the user device and other computing systems. Additionally, the location information derived from such a platform may permit additional functionality for the user device, the other computing systems or both.
[0013] Referring to FIG. 1 , methods and systems of a platform for tracking a user device may comprise a network 114 , one or more user devices 102 A-C in an environment 120 and enabled to communicate via the network 114 , a locator enabled to communicate via the network 114 , and a computing system 162 enabled to communicate via the network 114 and to determine the location in the environment of the one or more user devices 102 A-C. In embodiments, the locator may be a location beacon 160 enabled to receive presence information, such as a high frequency sound created by a user device 102 A. In some embodiments, the locator may be a transmitter 130 enabled to send presence information, such as a high frequency sound to be received by a user device 102 A, B, and/or C. In embodiments, the locator may be a plurality of locators.
[0014] In embodiments, the user device 102 A, B, and/or C may be a mobile device, such as a tablet, a mobile phone or a laptop. The user device 102 A, B, and/or C may comprise a processor 164 , a memory 168 , an application 138 , a microphone 144 , a speaker 142 , a display 154 , a data 148 , a screen lock facility 104 , a credential processing facility 110 , an authentication token reading facility 108 , a device location monitor 132 and an IR remote control facility 150 .
[0015] The computing system 162 may be a server, a workstation, a desktop, a laptop, a missile launching facility, a testing facility, a mobile device, a vehicle system and/or some other computing system. The network 114 may be one or more of a LAN, a wireless network, a wired network, and the like.
[0016] It may be imperative that the identity of the user be verified before granting access to the information stored on a device. Current solutions to this problem involve using a “screen lock” function, which requires users to enter a password or PIN before granting access to the device. However, passwords may still be a point of insecurity, since the passwords may be shared, stolen, sniffed, cracked, and/or have poor password strength. Such vulnerabilities relating to password security present a broad attack surface to malicious users. A need exists for improved solutions.
[0017] To provide the greatest level of security, methods and systems are provided herein to prevent unauthorized users from unlocking a device, including without limitation by reducing the exposure to attacks by requiring a user to authenticate himself or herself prior to unlocking the device.
[0018] The present invention includes a system for securing the screen lock of a device using credentials stored on an authentication token.
[0019] The present disclosure may provide greater security than just password protection in the respect that users of a device may be required to authenticate with an external authentication token before the device allows the users to access the screen lock.
[0020] This disclosure may increase the security of a mobile device by preventing access to the device screen lock. This may be accomplished using an external authentication token. Said tokens may provide a greater level of security by increasing the number of possible unlock combinations. For instance, a challenging password to remember may be 10 characters long, for example. By comparison, authentication tokens may provide passwords of 256 characters or longer. An example of such an authentication token is a Common Access Card (CAC). Another example of such an authentication token is a Personal Identity Verification card, such as a card implementing NIST standard FIPS 201 .
[0021] Referring to FIG. 1 , a device 102 A may comprise a screen lock facility 104 , an authentication token reading facility 108 and a credential processing facility 110 . In embodiments, devices 102 B and C may also comprise such facilities and components as device 102 A, and devices 102 B and C may also communicate with the same items as described in relation to device 102 A although such specific facilities, components, and communications may not be shown. In various embodiments described throughout, it is understood that while a specific elements, such as device 102 A, B, and/or C is described, it is understood that a plurality of devices (or other elements) may be employed as appropriate. The device 102 A, B and/or C may be a mobile device, such as a mobile phone, a smartphone, a tablet, a laptop or some other device. The operating system 104 may be Android, bada, BlackBerry OS, iOS, Series40, Symbian OS, Windows Phone or some other operating system. Such operating systems may support built-in screen lock facilities. The screen lock facility 104 may require user authentication (e.g. by providing PIN, or by requiring the user to swipe to unlock, etc.) in order to authenticate the user. A custom screen lock facility 104 may be implemented as software widget that replaces or otherwise overrides the operating system's built-in screen lock facility 104 . In embodiments, the screen lock facility 104 may be implemented either as an accessory application, or the screen lock facility 104 may implement code for directly controlling the native screen locking functions. For example, the screen lock facility 104 may use OptioCore code to implement a screen lock for an Android device.
[0022] In embodiments, a user may be required to authenticate on the device 102 A, B and/or C using an external authentication token 112 in order to access the screen lock facility 104 on the device 102 A, B and/or C. In embodiments, the user may also be required to authenticate on the device 102 A, B and/or C using an external authentication token 112 in order to decrypt a root file system on the device 102 A, B and/or C, and/or to use an operating system on the device 102 A, B and/or C. When the device 102 A, B and/or C is locked, the credential processing facility 110 may instruct the user of the device 102 A, B and/or C to provide authentication information via the authentication token reading facility 108 . The authentication token reading facility 108 may read authentication information from a physical device. The information may be an authentication token 112 . The authentication token 112 may be stored on a Common Access Card, Personal Identity Verification card (e.g. a card implementing NIST standard FIPS 201 ), a smartcard, a USB token, a SD card, a key fob, or some other physical device. The authentication token 112 may be a cryptographic key, such as a public key certificate, a digital signature, biometric data, a user id, or some other authentication information. In some embodiments, the authentication token reading facility 108 may be an external device connected to the device 102 A, B and/or C. In such embodiments, the authentication token reading facility 108 may be configured to communicate with the device 102 A, B and/or C via a communications medium, such as Bluetooth, near field communication (“NFC”), Wi-Fi, or other wired or wireless communications medium. For example, the authentication token reading facility 108 may be a smartcard reader connected to the device 102 A, B and/or C via Bluetooth.
[0023] In embodiments, the device 102 A, B and/or C may be enabled to connect to a network 114 . In such embodiments, authenticating the user on the device 102 A, B and/or C may include communicating first, second, and third authentication data over a short-range wireless signal between the device 102 A, B and/or C and an in-location access point, wherein the second authentication data from the device 102 A, B and/or C is based on the first authentication data from the in-location access point and the third authentication data from the in-location access point is based on the second authentication data; communicating a fourth authentication data between the mobile device and a web-based information system, wherein the fourth authentication data comprises at least a portion of at least one of the first, second, and third authentication data; and authenticating access to network accessible content by the mobile device with the web-based information system. The first authentication data may be the authentication token 112 data. The web-based information system may be a proxy 118 . For example, the authentication token reading facility 108 associated with the device 102 A, B and/or C may receive the authentication token 112 via NFC, send the second authentication data to the in-location access point via Bluetooth heartbeat messages, receive the third authentication data as responses to the Bluetooth heartbeat messages, send a request to a web proxy 118 that includes the third authentication data (e.g. in the form of hypertext transport protocol (HTTP) request with such data in the HTTP headers, for example), and receive access to the device if the proxy 118 determines that the user is authorized, based on the third authentication data.
[0024] The credential processing facility 110 may determine whether the authentication token 112 data is valid and whether the user is permitted to access the screen lock facility 104 , based on the user provided authentication token 112 . Credential processing may include local or distributed processing, using processing and storage capabilities of the authentication token device 112 or using remote (e.g., server-based) processing capabilities. Upon determining that the authentication token 112 data is valid and the user is permitted to access the screen lock facility 104 , the device 102 A, B and/or C may present the user with the unlock screen and prompt the user for a password and/or PIN. Upon determining that the authentication token 112 data is invalid and/or the user is not permitted to access the screen lock facility 104 , the credential processing facility 110 may prevent the device 102 A, B and/or C from presenting the user with the unlock screen. In some embodiments, the credential processing facility 110 could erase part or all of the data stored on the device 102 A, B and/or C upon a predetermined number of failed authentication attempts.
[0025] For example, the user of the device 102 A, B and/or C may provide a smartcard to be read by the authentication token reading facility 108 associated with the device 102 A, B and/or C, where the smartcard includes the user's authentication token 112 . The authentication token 112 data may be one or more X.509 certificates. In this example, the authentication token reading facility 108 may read the authentication token 112 from the smartcard and provide the authentication token 112 information to the credential processing facility 110 . The credential processing facility 110 may, then, determine whether the user is authorized to access the screen lock facility 104 , based on the authentication token 112 information.
[0026] Referring now to FIG. 4 , the process for authenticating the user may comprise locking a device 402 ; prompting a user to provide an authentication token 404 ; reading, by the device, the authentication token 408 ; determining, by a credential processing facility, whether the user is authorized to access the device, based on the authentication token 410 ; and granting a user access to the device's unlock screen. In some embodiments, granting the user access to the device's unlock screen may include presenting the unlock screen, if the user is determined to be authorized by the credential processing facility 414 . In some embodiments, presenting the unlock screen 414 may include prompting the user for a password and/or PIN, if the user is determined to be authorized by the credential processing facility. If the user is unauthorized to access the device's unlock screen, based on the authentication token, then the device may prohibit access to the unlock screen by the user 412 .
[0027] In retail store environments, such as BestBuy, Wal-Mart, Target, and others, the appropriation of customer service representatives to particular areas of the store is typically performed on a predetermined schedule. For example, at any given time, three customer service reps may be assigned to the electronics section, while two others are in home goods. Currently, there is no effective method for determining, in real time, the number of customer service representatives that are needed in a given product section of a store. The most effective method currently employed is for customers to actively seek out existing personnel. However, this can become problematic in times of heavy volume, since personnel in one section may become overwhelmed while personnel in another section are idle. It would be advantageous for a retail store to be able to dynamically appropriate personnel based on number of customers in a particular area.
[0028] Therefore, it may be useful to implement a system for identifying the locations and distribution of customers within a store and tracking the same based on the locations of the customers' mobile computing devices. Location services, such as GPS provide reliable and precise location information when the receiver has a clear view of the sky. However, these technologies are not effective indoors, making them unsuitable for use in determining concentrations of customers at particular product areas within a retail store. Instead, it may be desirable to utilize a network of transmitters, transmitting an electronic heartbeat message to establish a precise location for each user in the store.
[0029] Referring to FIG. 1 , in embodiments, methods and systems of a customer service representative dispatch system to locate and track customers in an environment 120 may comprise a network 114 ; one or more transmitters 130 A-C located in the environment 120 and enabled to emit an electronic heartbeat message and to connect to the network 114 ; a user device 102 A-C enabled to connect to the network 114 and to send location information based on a received electronic heartbeat message; and a server 122 enabled to connect to the network 114 . The server 114 may be comprised of a customer location monitor facility 124 enabled to track the user device 102 A-C based on the location information, and a customer service dispatch facility 128 enabled to dispatch a customer service representative based on the user device 102 A-C location. In embodiments, such device 102 A, B and/or C may further comprise additional devices as would suit the number of users in the environment.
[0030] In embodiments, the transmitter 130 A-C may be enabled to send an electronic heartbeat message. Such heartbeat message may utilize one or more protocols, such as, but not limited to Wi-Fi, Bluetooth, Bluetooth LE, ultrasonic sound, Zigbee and the like. In embodiments, a transmitter may broadcast a unique identifier. For example, if an environment 120 has a plurality of transmitters 130 A-C, each transmitter 130 may broadcast its own unique identifier so that the location within the environment 120 of a customer's mobile device 102 A, B and/or C may be determined based on the unique identifier(s) received by the customer's mobile device 102 A, B and/or C.
[0031] In some embodiments, the customer mobile computing device 102 A-C may be a cellular phone, such as an iPhone, a Motorola Droid Razr Maxx, a HTC One X, a Samsung Focus 2, a Samsung Gusto 2, or some other cellular phone. In other embodiments, the customer mobile computing device may be a tablet, such as an iPad, an Asus Eee Pad Transformer Prime, a Sony Tablet S, a Samsung Galaxy Tab 10.1, or some other tablet.
[0032] The server 122 may be comprised of a customer location monitor facility 124 and a customer service dispatch facility 128 . The server may be connected to the one or more transmitters 130 A-C in the environment via a network 114 . The network 114 may be one or more of a wireless network, a wired network, a LAN, a WAN, a MAN or some other network. In some embodiments, the server 122 may also be connected to a data store 134 . Such data store 134 may be a database or file system.
[0033] The customer mobile computing device 102 A, B, and/or may be enabled to use the unique identifier received from a transmitter 130 A, B and/or C to determine the said customer mobile computing device's 102 A, B and/or C location in the environment 120 . In some embodiments, the step of determining may involve uploading the unique identifier by the customer mobile computing device 102 A, B and/or C to the server 122 via the network 114 . The customer location monitor facility 124 on the server 122 may use the unique identifier to look up in a data store 134 the location of the transmitter 130 A, B and/or C transmitting said unique identifier, where the data store 134 may store the unique identifier associated with each such transmitter and the location of each such transmitter. In embodiments, determining the location of the customer mobile computing device 102 A, B and/or C may comprise the customer mobile computing device 102 A, B and/or C comparing a first identifier with a local data store, such as a database or file system, containing a plurality of identifiers and corresponding location information to determine the location of a first transmitter 130 A. The location of the first transmitter 130 A may then be used to determine the location of the customer mobile computing device 102 A, B and/or C based on one or more of the configuration parameters of said electronic heartbeat message and the transmitter 130 A (e.g. the range of the transmitter's signal, a triangulation based on a plurality of heartbeat messages from a plurality of transmitters, etc.).
[0034] In embodiments, once the location of the customer mobile computing device 102 A has been determined, said location of mobile computing device 102 A, B and/or C may be accessed at the server 122 . In some embodiments, the server 122 may not be the same server 122 that determined the location of the customer mobile computing device 102 A, B and/or C. For example, the customer location monitor facility 124 may determine the location of the customer mobile computing device 102 A, B and/or C and pass the location information to the customer dispatch facility 128 . The customer service dispatch facility 128 on the server 122 may then, automatically or otherwise, dispatch one or more customer service representatives to the location in the environment 120 where the customer mobile computing devices 102 A, B and/or C is located. The customer service dispatch facility 128 may also be enabled to perform business intelligence based on the customer mobile computing devices 102 A, B and/or C location information. For example, the customer service dispatch facility 128 may determine that there are a sufficient number of customer service representatives in the vicinity of the customer mobile computing devices 102 A, B and/or C. In another example, the customer service dispatch facility 128 may determine that there are more customers in a different location in the environment and that one or more customer service representatives in the vicinity of the customer mobile computing devices 102 A, B and/or C should be dispatched to a location of greater need in the environment 120 . In embodiments, a person may actively monitor the system and/or data therefrom and may dispatch personnel based on the same. The step of dispatching could occur in other ways as well.
[0035] Referring now to FIG. 5 , the process for identifying the location of a user device may comprise entering a shopping environment by a user with a device 502 , transmitting a heartbeat message by a transmitter 504 , receiving the heartbeat message by the user device 508 , determining the user device's location based on the heartbeat message 510 , dispatching to a location one or more customer service representatives based on the number of devices at the user device's location 512 . As discussed above, the environment may be a store, an arena, a mall, or some other shopping environment. Similarly, as discussed above, the user device may be a mobile computing device, such as a mobile phone or a tablet. As also discussed above, the heartbeat message may include a unique identifier. In embodiments, the unique identifier may be location-related information (e.g. the coordinates of the transmitter, the name of a section or some other location-related information).
[0036] In embodiments, the heartbeat message may comprise one or more of a unique identifier, a location identifier and/or some other identifier information. In embodiments, determining the user device's location based on the heartbeat message 510 may comprise determining the location by the user device. For example and as discussed above, the user device may determine its location by comparing the heartbeat message to data in a local data store. In embodiments, such local data store may reside on the user device. In some embodiments, determining the user device's location based on the heartbeat message 510 may comprise determining the location by a server. For example and as discussed above, the user device may receive a heartbeat message with a unique identifier from a transmitter, transmit the unique identifier to a server via a network, and the server may determine the location of user device based on the received unique identifier.
[0037] In embodiments, dispatching to a location one or more customer service representatives based on the number of devices at the user device's location 512 may further comprise determining a heat map of user devices in the shopping environment, determining a heat map of customer service representatives in the shopping environment, determining a redistribution of customer service representatives by comparing the two heat maps, and dispatching to a location or more customer service representatives. For example, if the user device is located in an area with a ratio of customers-to-customer service representatives is over a specified threshold, a customer service representative may be dispatched to that location to provide additional assistance. The step of dispatching may occur automatically using an automated dispatch system, or could include a person actively monitoring the system and dispatching personnel as appropriate. The step of dispatching could occur in other ways as well. Determining a redistribution of customer service representatives may further comprise a business intelligence analysis. For example, the server may perform one or more of the following steps in connection with determining the redistribution of customer service representatives: record a customer shopping pattern, record a customer service representative redistribution outcome, analyze a customer shopping pattern, analyze a customer service representative redistribution outcome, or some other business intelligence action.
[0038] Businesses may also benefit from the ubiquity of mobile devices and networks by using information regarding the locations of user devices to dispense coupons for encouraging users in certain locations.
[0039] Referring to FIG. 1 , in embodiments, systems and methods for dispensing coupons based on the location of a user may comprise providing a user device 102 A, B and/or C, which may comprise a display 154 and a microphone 144 , and which may execute an application 138 ; providing a transmitter 130 A, B and/or C, wherein the transmitter 130 A, B and/or C may be enabled to emit a high frequency sound and may be located in an environment 120 ; receiving, by the microphone 144 on the device 102 A, B and/or C, a high frequency sound from the transmitter 130 A, B and/or C; and altering the display 154 , by the application 138 , to provide a coupon, based on the one or more of the characteristics and contents of the high frequency sound. In embodiments, the transmitter 130 A, B and/or C may be a plurality of transmitters 130 A-C. In embodiments, the display 154 may be a touch screen. The transmitter 130 may be a speaker. The characteristics and contents of the high frequency sound may include location information of the transmitter 130 A, B and/or C, location information of an item in the environment (e.g. the location of a good for sale in a store), a timestamp, the frequency, a pattern of the high frequency sound, or some other characteristics and contents.
[0040] For example, the user device 102 A, B and/or C may execute an application 138 that runs in the background and that monitors the microphone 144 for high frequency sounds. When the application 138 determines that the microphone 144 has received a broadcast from a speaker within a retail store, the application 138 may change the display 154 to depict a coupon, such as in a web browser or other application, for use in the retail store.
[0041] In some embodiments, the transmitter 130 A, B and/or C may emit a high frequency sound to alter one or more of a sale, transaction, lease, offer for sale, proposed transaction, or other information. Such alteration may be a change to the sale price, the characteristics of a sale, lease, or other transaction. For example, the transmitter 130 A, B and/or C may be located in a store in the vicinity of a particular good that the store is marketing heavily. When the application 138 determines that the microphone 144 has received a broadcast from the transmitter 130 A, B and/or C, the application 138 may change the sale price for the good and the like.
[0042] In embodiments, the high frequency sound emitted by the transmitter 130 A, B and/or C may include an information associated with a product or category of products located in proximity with the transmitter 130 . For example, the transmitter 130 may be located near a particular television or brand of televisions, and the high frequency sound emitted by the transmitter 130 may include information regarding discounts on such televisions.
[0043] In embodiments, when the application 138 determines that the microphone 144 has received the high frequency sound emitted by the transmitter 130 A, B and/or C, the application 138 may send information related to the high frequency sound to a server 122 . The information may be one or more characteristics and contents of the high frequency sound. The server 122 may include a coupon analytics facility 158 . The coupon analytics facility 158 may, based on the information received from the application 138 , determine a coupon to be displayed on the device display 154 and send such coupon to the device 102 A, B and/or C via the network 114 . Additionally, the coupon analytics facility 158 may be enabled to direct the transmitter 130 A, B and/or C to emit a particular high frequency sound in order to change the response of the application 138 . Returning to the example above with the transmitter 130 A, B and/or C near the televisions, the coupon analytics facility 158 may direct the transmitter 130 A, B and/or C to change the high frequency sound it emits so that an application 138 would display a new sales price or an offer for a discount on an existing price. In such embodiments, the coupon analytics facility's 158 direction to a transmitter 130 A, B and/or C to emit a particular high frequency sound may be based on one or more of marketing input, inventory input, a timer input, customer location input, other customer data input, or other inputs.
[0044] Currently, large retail locations do not have a good method for analyzing the movements of customers within a store. This kind of information could be extremely valuable to commercial organizations that typically operate in large spaces, helping them to arrange the store layout in such a way that improves customer experience, increases purchases and reduces lost sales to other retailers, such as e-commerce platforms. Furthermore, such information could also allow retailers to deliver targeted advertisements based on previous customer interest in products and services.
[0045] As described above, businesses may track customers in a retail space in order to dispatch customer service representatives. Tracking customers may also be useful for analyzing the behavior of the customers
[0046] Referring again to FIG. 1 , methods and systems of analyzing customer behavior based on tracking customer locations may comprise providing a transmitter 130 A, B and/or C in an environment 120 wherein such transmitter is enabled to emit a high frequency sound signal; providing one or more customers each with a user device 102 A, B and/or C comprising a microphone 144 enabled to receive a high frequency sound signal, and wherein the user device 102 A, B and/or C is enabled to send data based on the received high frequency sound signal; providing a computing system 162 , wherein the computing system 162 is enabled to receive data from each such user device 102 A, B and/or C and to determine the user device 102 A, B and/or C location in the environment 120 based on such received data; and analyzing the user device 102 A, B and/or C location information by the computing system 162 to identify useful characteristics. In embodiments, such device 102 A, B and/or C may further comprise additional devices as would suit the number of users in the environment. Such analysis may include one or more of generating a heat map based on where the user spent time in the environment 120 , comparing what the user purchased against the heat map, totaling the time user spent in the environment 120 , comparing what the user purchased against other users, comparing the user heat map with other heat maps, or other analyses. Based on the analysis, the business for whom the analysis is performed may perform one or more of push data to customers (e.g. coupons, updated sales or marketing materials, product comparison information, etc.), optimize the layout of the business (e.g. move products to be highlighted to certain end caps or other high-traffic areas), provide information to vendors (e.g. customer heat map information related to the vendors' products, etc.) and use the analysis for other business purposes.
[0047] For example, a grocery store may have high frequency emitting transmitters located in several aisles to provide the customers devices with location information. The customers devices could transmit periodic updates to a server 122 connected via the store's wireless network 114 . The store's server 122 may analyze the customer location data received to identify customer movement patterns. The customer movement patterns to be used, for example, by a consultant, to reorganize the layout of the store in order to make a typical customer's movement path more efficient or draw customer attention to certain sections of the store to increase revenue and customer experience.
[0048] Methods and systems of a customer service representative dispatch system may be used to locate and track customers in an environment. Such methods and systems may be associated with analyzing customer behavior based on tracking customer locations as described herein, for example. By way of example, the determination to dispatch a customer service representative may be based on the results of analyzing customer behavior based on tracking customer locations. In this example, based on the analysis of the customer behavior, a business may note that there is not much customer traffic near where a popular consumer good is being sold, and, therefore, may dispatch one or more customer service representatives to that area to help customers find the good.
[0049] Methods and systems for dispensing coupons based on the location of a user may be used to track customers in an environment and offer for sale some good in the environment. Such methods and systems may be associated with analyzing customer behavior based on tracking customer locations. By way of example, the determination to dispense a coupon may be based on the results of analyzing customer behavior based on tracking customer locations, as described herein, for example. In this example, based on the analysis of the customer behavior, the business may determine that one or more users with certain heat map patterns are less likely to buy certain goods sold by the business. Based on this determination, the business may issue a coupon for such goods to users who exhibit similar or the same patterns.
[0050] As devices become more mobile and networks become more ubiquitous, device users have a growing number of options of outputs to connect to their devices. For example, many home audio or theater systems are networked and may contain multiple speakers and other output devices throughout a home. Similarly, offices have multiple output sources for users, such as monitors at a user's desk and a projector in a meeting room. Often, users of these systems will move throughout their environment, whether at home or in the office, and switch their output device. In the home user example, the user may move through their home while listening to or otherwise consuming content. Currently, such users must manually turn on and turn off output devices based on the room they are entering or leaving respectively. It would be advantageous for such a system to be able to automatically enable or disable output devices based on the detected location of the user. Again, providing transmitters throughout an environment may provide a desirable solution for such automatic switching.
[0051] Referring again to FIG. 1 , in embodiments, systems and methods for automatic switching of output devices based on a location may comprise providing a user device 102 A, B and/or C in an environment 120 , providing a plurality of output devices 140 A-B located in the environment 120 , providing one or more transmitters 130 A-C in the environment for determining the location of the user device 102 A, B and/or C within the environment 120 , streaming a media stream to a first output device 140 A, determining the location of the user device 102 A, B and/or C in the environment 120 , and switching a media stream from a first output device 140 A to a second output device 140 B, based on the location determination. The media stream may be an audio stream (e.g. a radio broadcast, a podcast, mp3 audio, audio played from a CD, or some other media stream), a video stream (e.g. images to be displayed on a monitor), an audio/video stream (e.g. a movie, a television show or some other combined audio and video stream), or some other media stream.
[0052] The environment 120 may be a home, an office, or some other environment. The user device 102 A, B and/or C may be a mobile device, such as a cell phone, a personal assistant, a tablet, a laptop or some other mobile device. The user device 102 A, B and/or C may be comprised of a microphone 144 . An output device 140 may be a monitor, a television, an audio component, a printer, a media device (e.g. a Roku, an Apple TV, a PlayStation, an Xbox, etc.), another user device 102 B, or some other output device.
[0053] In embodiments, the user device 102 A, B and/or C, the transmitter 130 , and the output devices may be connected via a network 114 . The network 114 may be wired or wireless. The network 114 may be a LAN.
[0054] In embodiments, the transmitters 130 A-C may be enabled to emit a message and/or data. In embodiments, such message may be a high frequency. As previously noted, such message may utilize one or more protocols, such as, but not limited to Wi-Fi, Bluetooth, Bluetooth LE, ultrasonic sound, Zigbee and the like.
[0055] In embodiments, the user may select an output device 140 for the user device 102 A, B and/or C. Selecting the output device 140 may include one or more of selecting the initial output device 140 A and/or B, selecting a default output device 140 , selecting the output device 140 A and/or B for the current location, selecting the output device 140 A and/or B for a different location and selecting the output device 140 A and/or B for some other purpose. Selecting an output device 140 A and/or B may also include defining a location within the environment 120 .
[0056] When a user with a user device 102 A, B and/or C enters into an environment, the user device may be enabled to receive a message from a first transmitter 130 A. For example, the user may enter the living room in his home and his cell phone may receive a high frequency sound from a first transmitter 130 A located in the living room. In this example, the user device's 102 A, B and/or C may receive, via a microphone 144 , the high frequency sound from the first transmitter 130 A. If the user has an output device 140 A, for example, associated with that location, the device 102 A, B and/or C, upon receiving the high frequency sound may route output to the associated output device 140 A. In this example, the output device 140 A may be a set of speakers located in the living room. If, in this example, the user has a second transmitter 130 B located in his bedroom and walks to his bedroom, the user device 102 A, B and/or C may receive a high frequency sound from the second transmitter 130 B located in the bedroom. Upon receiving the new high frequency sound and the user device 102 A, B and/or C may switch the media stream to the second output device 140 B associated with the bedroom, for example, a different set of speakers in the bedroom.
[0057] In some embodiments, the media stream may be from a remote computing system (e.g. a streaming media device, like a Roku, or a cable box, etc.). In such embodiments, the user device 102 A may, in response to receiving a high frequency sound from a transmitter 130 A, B and/or C, may transmit data (e.g. observed characteristics of the high frequency sound) to a remote computing system, such as a server 122 . The remote computing system may associate the (e.g. the characteristics of the high frequency sound) with an output device 140 A and/or B and, then switch the media stream to the output device 140 .
[0058] In embodiments, the device 102 A, B and/or C may be further enabled to determine when it no longer is receiving a message from a first transmitter 130 A. When the device 102 A, B and/or C no longer is receiving a message from the first transmitter 130 A, the device 102 A, B and/or C may communicate such determination to the server 122 . In response to receiving such determination, the server 122 may terminate the media stream to the first output device 140 A.
[0059] As devices become more mobile and networks become more ubiquitous, device users also have a growing number of devices that may be controlled remotely, either by IR signals or over some other protocol. As previously noted, many home audio or theater systems are networked and may contain multiple speakers and other output devices throughout a home, and such devices may be controlled remotely, including by other devices on the network. Since the user already has one device, it may be desirable to enable that device to control the other devices in the environment. Furthermore, it may be desirable to enable the device to automatically detect its location and configure itself to control the devices in the same location. In the home user example, the user may start watching a media stream in one room and use the user device to control the home media system in the first room. If the user moves to another room to finish watching the media, it may be useful to have the user device identify the location change and reconfigure which devices it is set to control. Currently, such users must either keep separate controls for each room, or manually switch a controller based on the room they are entering or leaving. It would be advantageous for such a system to be able to automatically enable or disable the control of the output devices based on the detected location of the user. Again, providing transmitters throughout an environment may provide a desirable solution for such automatic switching.
[0060] Referring still to FIG. 1 , in embodiments, systems and methods for automatic switching of the controls of a plurality of output devices based on a location may comprise providing a user device 102 A, B and/or C in an environment 120 , providing a plurality of output devices 140 A-B located in the environment 120 , providing one or more transmitters 130 A-C in the environment for determining the location of the user device 102 A, B and/or C within the environment 120 , providing a control interface for the first output device 140 A on the display 154 of the user device 102 A, B and/or C, determining the location of the user device 102 A, B and/or C in the environment 120 , and modifying the IR remote control facility 150 and the display 154 of the user device 102 A, B and/or C to control of a second output device 140 B, based on the location determination. As noted above, the user device 102 A, B and/or C may include a microphone. The transmitters 130 A-C may be enabled to emit a message and may each be associated with one of the output devices 140 A-B. In some embodiments, a transmitter 130 may be physically located within close proximity to the output device 140 controlled by the user device 102 . For example, the transmitter 130 A, B and/or C associated with a speaker system in one room may be located adjacent to that speaker system, and the transmitter 130 A, B and/or C associated with a speaker system in another room would be located adjacent to that speaker.
[0061] In some embodiments, the systems and methods may further comprise altering an output from the user device 102 A, B and/or C based on the characteristics or contents of the message received from a transmitter 130 A, B and/or C. For example, the user device 102 A, B and/or C may be enabled to, based on the frequency of sound received from a transmitter 130 A, B and/or C, download and configure specific IR remote control facility codes for controlling an output device in the environment 120 via the IR remote control facility 150 on the user device 102 A, B and/or C.
[0062] Modifying the IR remote control facility on the user device 102 A, B and/or C may further comprise determining which output device 140 is located at a location and associated with a transmitter 130 A, B and/or C, based on the message from the transmitter 140 A and/or B, then modifying the control interface. Modifying the control interface may also include changing one or more output signals and/or protocols from the user device 102 A, B and/or C for controlling the correct output device 140 A and/or B. For example, the user device 102 A, B and/or C may, but is not limited to, determine its location based upon a high frequency sound from a transmitter 130 A, B and/or C in the room, and adjust the volume of all speakers within a home in order to maintain a consistent volume to the user as they move from room to room.
[0063] Returning the example of the user at home, the user may walk into the living room. The user device 102 A, B and/or C may receive a message from a first transmitter 130 A located in the living room. Upon receiving the message from the first transmitter 130 A, the device may modify the IR remote control facility 150 to control an output device 140 A and modify the display 154 to depict controls for an output device 140 A in the living room, such as a home theater system. The controls depicted on the display 154 may include the controls available via the IR remote control facility 150 , such as a volume control, frequency tuning control, a device input control, a power control, a DVD player control or some other device control.
[0064] Staying with this example, when the user walks into the kitchen, the user device 102 A, B and/or C may receive a message from a second transmitter 130 B located in the kitchen. Upon receiving the message from the second transmitter 130 B, the device may modify the IR remote control facility 150 and the display 154 to depict controls for an output device 140 B in the kitchen, which may be an iPod docking station, for example.
[0065] Methods and systems of automatically switching of output devices based on a location may be used to track a user in environment and provide dynamic output selection, based on the user's location. Such methods and systems may be associated with automatically switching the controls for a plurality of output devices. For example, upon determining that a user has moved from one location associated with a first output device to a second location associated with a second output device, the user device may automatically switch the media stream from the first to the second output device and automatically switch the controls and the display on the user device from the controls associated with the first output device to those associated with the second output device. In embodiments, such determination may be made by receiving at the device a high frequency message from a transmitter associated with a specific output device, as described herein, for example.
[0066] In addition to the foregoing security and business benefits discussed above, locating and tracking a user based on the location of the user's device may have game and/or multiplayer game applications. This may provide an inexpensive way of introducing potentially asymmetric information dissemination to players of a multiplayer game. Asymmetric gameplay is an emerging sector of the game industry, and has the potential to drive a large amount of innovation, as evidenced by the development of the Wii U.
[0067] Referring still to FIG. 1 , in embodiments, systems and methods of detecting players for a multiplayer game, may comprise a multiplayer game; a first user device 102 A for playing the game and comprising a display 154 , a microphone 144 and a speaker 142 for emitting a high frequency sound signal; and a second user device 102 B for playing the multiplayer game and comprising a display 154 , a microphone 144 and a speaker 142 for emitting a high frequency sound signal, wherein the second user device 102 B is enabled to alter the content of the first user device's 102 A display 154 , based on a high frequency sound signal emitted by the speaker 142 of the first user device 102 A. The multiplayer game may be an application 138 executing on the device 102 A, B and/or C. The multiplayer game may be a coop game, a competitive coop game, a sports game, a deathmatch-style game, a capture-the-flag-style game, a king-of-the-hill-style game, or some other multiplayer game. The device 102 A, B and/or C may be a game system, such as Wii U, an Xbox, a PlayStation 3, a PlayStation Vita, a Gameboy, a tablet (e.g. an iPad) with a game installed, a controller for a game system (e.g. a Wii U GamePad) or some other game system and/or component of a game system. Altering the content of the first user device's 102 A display 154 based on a high frequency sound signal emitted by the speaker 142 of the first user device 102 A may include altering the display 154 to show location information related to the user of the second user device 102 B.
[0068] For example, two players may be playing a multiplayer game on a Wii U in the same room. The players' characters may be located in different parts of the same game map and the first player may be hiding from the second player. The first player's controller may emit a sound, such as a high frequency sound based on the first player's character's location in the game map. The second player's GamePad may receive the sound, analyze it in whole and/or in part, and update the map information displayed on the GamePad to indicate the general direction of the first player's character. In embodiments, the emitted sound may alter one or more of various devices and/or one or more of various devices may emit a sound for altering content of the display of one or more devices based on an analysis of the sound and/or an analysis of the sound and other data and/or one or more items. In embodiments, devices such as a game headset could alter the intensity of an indicator and/or display to reflect a detected amplitude of a specific sound frequency, and may thereby indicate the proximity of other players.
[0069] In some situations, it may be beneficial to ensure that all the users of a particular system are present in the same location before granting any user access to a system. A potential example of this need arises from a testing scenario in which no user should be granted an unfair advantage over another user by being granted access to test materials before any other user. Another example involves the authorization of particular actions that carry significant consequences, such as launching a missile or overriding a safety control. In such cases, it may be necessary to guarantee that the required users are physically present together before allowing a specific action (e.g. launching a missile) to be executed. This may be accomplished by securing access to some resource, such as a computing system, until all the required users are located in the vicinity of the resource. Tracking and confirming the locations of the required users may be accomplished with a location beacon to track unique sounds emitted by enabled devices carried by the required users.
[0070] Referring again to FIG. 1 , in embodiments, methods and systems of authenticating a group of users may comprise a plurality of user devices 102 A, B and/or C, each comprising a speaker for emitting a high frequency sound signal; a location beacon in an environment 120 and enabled to receive a plurality of high frequency sound signals; and a computing system enabled to communicate with the location beacon and comprising a location determination facility that is enabled to provide access to the computing system based on a determination that every user of a plurality of users is located within the environment. The high frequency sound signals may be unique for each user device 102 A, B and/or C, for example in a given environment 120 , so that each user device 102 A, B and/or C may be uniquely identified. For example, each device 102 A, B and/or C may be assigned a high frequency sound signal with a unique variation in frequency or other acoustic characteristic.
[0071] For example, a testing environment may have a fixed location beacon 160 that is configured to receive ultrasonic signals. The students who are required to be present for the test may each have a user device 102 A, B and/or C. Each device 102 A, B and/or C may have a speaker 142 enabled to produce an ultrasonic signal. The location beacon 160 and the user devices 102 A, B and/or C may each be connected to a computing system 162 via a wireless network 114 . The user devices 102 A, B and/or C may receive from the computing system 162 a specific ultrasonic signal configuration, unique to each device 102 . For example, when a user signs up for the test, the computing system 162 may send said user's device 102 A, B and/or C the specific ultrasonic signal configuration to be emitted for a period before the exam and during the exam. Each device 102 A, B and/or C may then transmit the specific signal with the configuration received from said computing system 162 . The location beacon 160 may provide updates to the computing system 162 regarding the ultrasonic signals from the devices received by the location beacon 160 . The computing system 162 may track which students are located in the testing environment based on the updates from the location beacon 160 . Once the computing system 162 determines that all the required students are located in the testing environment, the computing system 162 may begin the test and grant the students access to the test materials.
[0072] Referring now to FIG. 2 , authenticating a group of users may comprise providing a computing system, including a fixed location beacon configured to receive signals 202 ; entering of an environment by a user with a user device 204 ; receiving by the computing system via the location beacon of a signal from the user device 208 ; determining by the computing system whether all the users required in a group are in the environment, based on the received signals 210 ; providing access to the computing system if all the required users are in the environment 214 ; and accessing of the computing system by the group of users 218 . In embodiments, if not all the required users are in the environment, all the users may be prohibited from accessing the computing system 212 . In embodiments, where not all users are in the environment at a particular time, the system may continue receive signals from users until all users are present or some other defied time.
[0073] An additional application for location-based security is to secure access to data in a file system (i.e. read, write, execute, modify, delete, copy, and/or transmit) based on a user's location.
[0074] Referring again to FIG. 1 , systems and methods of controlling access to data on a device may comprise a first user device 102 A, comprising a speaker 142 enabled to send a heartbeat message; a second user device 102 B, comprising a microphone 144 enabled to receive a heartbeat message and a speaker 142 , enabled to send a first data, including data to indicate receipt or failure to receive the heartbeat message; and a third user device 102 C enabled to send a second data upon receiving the first data from the second user device 102 B and determining that the second data may be sent to the second user device. In embodiments, the determination of whether the second data may be sent to the second device may be a location-related determination. For example, the determination may be based whether the location of the second device is considered secure (e.g. based on where, whether the user of the second device is authorized to access the second data in the given location, whether the second data is related to the location of the second user device (e.g. the user of the second device may be permitted to access a second data related to a room of museum based on whether the second device is located in the relevant room in the museum), or some other location-related determination.
[0075] For example, a user device could pick up a high frequency sound broadcast by a speaker device, identify the frequency of the sound, and report the frequency to a remote file server in an effort to gain access to files on that server. The server would then process the reported data and determine whether to grant access to the mobile device.
[0076] In some embodiments, the heartbeat message may be sent as a high frequency sound embedded in television or radio media. A mobile device 102 A, B and/or C may be enabled to receive such media and use the high frequency sound to request content from a server 122 that may be relevant advertising content.
[0077] By way of example, in embodiments, controlling access to first data stored on a first device may include sending a heartbeat message from a second device to a third device (having memory, a processing unit and a microphone), prompting the third device to send second data to a fourth device (which may also be the first device) said data including, but not limited to, information signifying receipt or failure to receive heartbeat messages, so that the fourth device may process the second data in whole or in part to determine whether access to the first data should be granted to the third device. Such access may include the ability to read, copy, modify, delete and/or transmit said data. In embodiments, such firs, second, third, fourth, etc, device may comprise a plurality of devices such that messages are send to and from one or more devices at the steps described. In embodiments, a mobile device may pick up a high frequency sound broadcast by a speaker device, identify the frequency, and report the frequency to a remote file server in an effort to gain access to files on that server. The server may then process the reported data and determine whether to grant access to the mobile device.
[0078] An additional application for location-based security is to secure access to an application based on a user's location.
[0079] Referring again to FIG. 1 , methods and systems of controlling access to an application 138 on a device 102 A, B and/or C may comprise providing a transmitter 130 A, B and/or C enabled to emit a high frequency sound; providing a user device 102 A, B and/or C enabled to receive a high frequency sound; and blocking access by a user of the user device 102 A, B and/or C to an application on the user device, while the user device 102 A, B and/or C receives the high frequency sound from the transmitter 130 A, B and/or C.
[0080] For example, the transmitter 130 A, B and/or C may be located in a car, truck, other automobile, or other piece of machinery around which certain kinds of phone usage might be dangerous. In this example, the transmitter 130 A, B and/or C may broadcast a signal whenever the automobile is not in park, so that the driver's mobile device disables the SMS messaging application 138 during the operation of the automobile.
[0081] Methods and systems of controlling access to data on a device may be used to track users and either grant or block access to files, based on where the user is located. Such methods and systems may be associated with granting and/or blocking user access to one or more applications, based on where the user is located. Per an example above, a user located in a car may not be permitted to use the SMS application on the user's device while the car is running Additionally, the user may be permitted to access certain media files while in the car (e.g. MP3s) and prohibited from accessing certain other media files while in the car (e.g. video files). Tracking a player of game based on the location of the player's device is a species of the foregoing. So, for example, a function or data in multiplayer game may be associated with detecting or locating another player. Such function or data may be enabled or disabled, based on the proximity of a first player to a second player of the game.
[0082] The process of entering user credentials before being granted access to a computing system is a necessary yet tedious process. In many systems, it is imperative that a user is authenticated before being shown sensitive data in order to ensure, for example, privacy, confidentiality, or security. If only performed once, this process is trivial, but in environments where users must log in and log out of systems 20, 30, 40 or more times per day, this trivial amount of time becomes significant. It therefore becomes advantageous to streamline this process and provide a different authentication medium.
[0083] Mobile devices, such as smartphones, tablets and other mobile computing devices are becoming ubiquitous and, when tied to an individual, possess the capability to authenticate a user in a different system. A secured computing system may be maintained without requiring a nearby user to repeat the step of logging in by tracking the previously authenticated user's location.
[0084] Referring to FIG. 3 , systems and methods of logging in a current user to a computing device based on the user location may comprise providing a computing system enabled to communicate with a user's device 302 ; storing, by the computing system, the user's credentials capable of authenticating the user 304 ; authenticating on the computing system by the user with the user's device 308 ; determining by the computing system the location of the user based on the location of the user's device 310 (such location determination mechanism could be a system such as GPS or could be a proprietary system implemented using a technology such as ultrasonic sound, RF signals, Bluetooth signals, Wi-Fi signals, NFC tags, and/or the like); confirming the user's credentials by the user's device 312 ; transmitting by the user's device the user's credentials to the computing system 314 ; authenticating the user by the computing system if the determination is made that the user's device is in proximity to the computing system 320 ; and providing the user access to the computing system 322 . In embodiments, confirming the users credentials with the user device 312 may comprise requiring the user to re-authenticate if the user's credentials are not confirmed. In embodiments, if the user device is not within proximity to the computing system, the computing system may prohibit access by the user 318 and may require the user re-authenticate. In embodiments, the user may be required to confirm transmission of credentials before transmission. In embodiments, a user may be authenticated without user intervention. In embodiments, authenticating the user may include authenticating the user based on one or more of a token, a password, a PIN, biometrics (e.g. retina scan, thumbprint, voice recognition, etc.).
[0085] Referring again to FIG. 1 , the computing system 162 may be a server, such as a web server, a file server, an application server, a mail server, an SaaS, an IaaS, a PaaS, a media server, a FTP server or some other server. In other embodiments, the computing system 162 may be a laptop, a terminal, a desktop, a workstation, a game console or some other computing system. The user's device 102 A, B and/or C may be a smartphone, tablet or other mobile device.
[0086] The user device 102 A, B and/or C may determine its location by way of a location determination mechanism. This location determination mechanism could be a system such as GPS or could be a proprietary system implemented using a technology such as ultrasonic sound, RF signals, Bluetooth signals, Wi-Fi signals, NFC tags, and/or the like, such that the location of the user device 102 A, B and/or C can be determined to be close to the location of the computing system 162 . Upon determining, that the user device 102 A, B and/or C is in proximity to the computing system 162 , authentication credentials are automatically transmitted to the computing system 162 either directly or indirectly. In embodiments, transmitting the authentication credentials may include transmitting them via a network 114 , which may be a wireless LAN. The computing system 162 may then authenticate the user and may grant access to the secured content without user intervention at the computing system 162 . In some embodiments, the user device 102 A, B and/or C may require the user to confirm the transmission of credentials before transmission of credentials from the user device 102 A, B and/or C to the computing system 162 . In some embodiments, upon determining that the user device 102 A, B and/or C is no longer present at the location corresponding to the computing system 162 , the computing system 162 may automatically de-authenticate the user. A person of skill in the art would understand that arbitrary levels of security may be added to this system without significant deviation from the aforementioned embodiments, such as encryption, device authentication, and the like.
[0087] While only a few embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that many changes and modifications may be made thereunto without departing from the spirit and scope of the present invention as described in the following claims. All patent applications and patents, both foreign and domestic, and all other publications referenced herein are incorporated herein in their entireties to the full extent permitted by law.
[0088] The methods and systems described herein may be deployed in part or in whole through a machine that executes computer software, program codes, and/or instructions on a processor. The present invention may be implemented as a method on the machine, as a system or apparatus as part of or in relation to the machine, or as a computer program product embodied in a computer readable medium executing on one or more of the machines. In embodiments, the processor may be part of a server, cloud server, client, network infrastructure, mobile computing platform, stationary computing platform, or other computing platform. A processor may be any kind of computational or processing device capable of executing program instructions, codes, binary instructions and the like. The processor may be or may include a signal processor, digital processor, embedded processor, microprocessor or any variant such as a co-processor (math co-processor, graphic co-processor, communication co-processor and the like) and the like that may directly or indirectly facilitate execution of program code or program instructions stored thereon. In addition, the processor may enable execution of multiple programs, threads, and codes. The threads may be executed simultaneously to enhance the performance of the processor and to facilitate simultaneous operations of the application. By way of implementation, methods, program codes, program instructions and the like described herein may be implemented in one or more thread. The thread may spawn other threads that may have assigned priorities associated with them; the processor may execute these threads based on priority or any other order based on instructions provided in the program code. The processor, or any machine utilizing one, may include memory that stores methods, codes, instructions and programs as described herein and elsewhere. The processor may access a storage medium through an interface that may store methods, codes, and instructions as described herein and elsewhere. The storage medium associated with the processor for storing methods, programs, codes, program instructions or other type of instructions capable of being executed by the computing or processing device may include but may not be limited to one or more of a CD-ROM, DVD, memory, hard disk, flash drive, RAM, ROM, cache and the like.
[0089] A processor may include one or more cores that may enhance speed and performance of a multiprocessor. In embodiments, the process may be a dual core processor, quad core processors, other chip-level multiprocessor and the like that combine two or more independent cores (called a die).
[0090] The methods and systems described herein may be deployed in part or in whole through a machine that executes computer software on a server, client, firewall, gateway, hub, router, or other such computer and/or networking hardware. The software program may be associated with a server that may include a file server, print server, domain server, internet server, intranet server, cloud server and other variants such as secondary server, host server, distributed server and the like. The server may include one or more of memories, processors, computer readable media, storage media, ports (physical and virtual), communication devices, and interfaces capable of accessing other servers, clients, machines, and devices through a wired or a wireless medium, and the like. The methods, programs or codes as described herein and elsewhere may be executed by the server. In addition, other devices required for execution of methods as described in this application may be considered as a part of the infrastructure associated with the server.
[0091] The server may provide an interface to other devices including, without limitation, clients, other servers, printers, database servers, print servers, file servers, communication servers, distributed servers, social networks and the like. Additionally, this coupling and/or connection may facilitate remote execution of program across the network. The networking of some or all of these devices may facilitate parallel processing of a program or method at one or more location without deviating from the scope of the disclosure. In addition, any of the devices attached to the server through an interface may include at least one storage medium capable of storing methods, programs, code and/or instructions. A central repository may provide program instructions to be executed on different devices. In this implementation, the remote repository may act as a storage medium for program code, instructions, and programs.
[0092] The software program may be associated with a client that may include a file client, print client, domain client, internet client, intranet client and other variants such as secondary client, host client, distributed client and the like. The client may include one or more of memories, processors, computer readable media, storage media, ports (physical and virtual), communication devices, and interfaces capable of accessing other clients, servers, machines, and devices through a wired or a wireless medium, and the like. The methods, programs or codes as described herein and elsewhere may be executed by the client. In addition, other devices required for execution of methods as described in this application may be considered as a part of the infrastructure associated with the client.
[0093] The client may provide an interface to other devices including, without limitation, servers, other clients, printers, database servers, print servers, file servers, communication servers, distributed servers and the like. Additionally, this coupling and/or connection may facilitate remote execution of program across the network. The networking of some or all of these devices may facilitate parallel processing of a program or method at one or more location without deviating from the scope of the disclosure. In addition, any of the devices attached to the client through an interface may include at least one storage medium capable of storing methods, programs, applications, code and/or instructions. A central repository may provide program instructions to be executed on different devices. In this implementation, the remote repository may act as a storage medium for program code, instructions, and programs.
[0094] The methods and systems described herein may be deployed in part or in whole through network infrastructures. The network infrastructure may include elements such as computing devices, servers, routers, hubs, firewalls, clients, personal computers, communication devices, routing devices and other active and passive devices, modules and/or components as known in the art. The computing and/or non-computing device(s) associated with the network infrastructure may include, apart from other components, a storage medium such as flash memory, buffer, stack, RAM, ROM and the like. The processes, methods, program codes, instructions described herein and elsewhere may be executed by one or more of the network infrastructural elements. The methods and systems described herein may be adapted for use with any kind of private, community, or hybrid cloud computing network or cloud computing environment, including those which involve features of software as a service (SaaS), platform as a service (PaaS), and/or infrastructure as a service (IaaS).
[0095] The methods, program codes, and instructions described herein and elsewhere may be implemented on a cellular network having multiple cells. The cellular network may either be frequency division multiple access (FDMA) network or code division multiple access (CDMA) network. The cellular network may include mobile devices, cell sites, base stations, repeaters, antennas, towers, and the like. The cell network may be a GSM, GPRS, 3G, EVDO, mesh, or other networks types.
[0096] The methods, programs codes, and instructions described herein and elsewhere may be implemented on or through mobile devices. The mobile devices may include navigation devices, cell phones, mobile phones, mobile personal digital assistants, laptops, palmtops, netbooks, pagers, electronic books readers, music players and the like. These devices may include, apart from other components, a storage medium such as a flash memory, buffer, RAM, ROM and one or more computing devices. The computing devices associated with mobile devices may be enabled to execute program codes, methods, and instructions stored thereon. Alternatively, the mobile devices may be configured to execute instructions in collaboration with other devices. The mobile devices may communicate with base stations interfaced with servers and configured to execute program codes. The mobile devices may communicate on a peer to peer network, mesh network, or other communications network. The program code may be stored on the storage medium associated with the server and executed by a computing device embedded within the server. The base station may include a computing device and a storage medium. The storage device may store program codes and instructions executed by the computing devices associated with the base station.
[0097] The computer software, program codes, and/or instructions may be stored and/or accessed on machine readable media that may include: computer components, devices, and recording media that retain digital data used for computing for some interval of time; semiconductor storage known as random access memory (RAM); mass storage typically for more permanent storage, such as optical discs, forms of magnetic storage like hard disks, tapes, drums, cards and other types; processor registers, cache memory, volatile memory, non-volatile memory; optical storage such as CD, DVD; removable media such as flash memory (e.g. USB sticks or keys), floppy disks, magnetic tape, paper tape, punch cards, standalone RAM disks, Zip drives, removable mass storage, off-line, and the like; other computer memory such as dynamic memory, static memory, read/write storage, mutable storage, read only, random access, sequential access, location addressable, file addressable, content addressable, network attached storage, storage area network, bar codes, magnetic ink, and the like.
[0098] The methods and systems described herein may transform physical and/or or intangible items from one state to another. The methods and systems described herein may also transform data representing physical and/or intangible items from one state to another.
[0099] The elements described and depicted herein, including in flow charts and block diagrams throughout the figures, imply logical boundaries between the elements. However, according to software or hardware engineering practices, the depicted elements and the functions thereof may be implemented on machines through computer executable media having a processor capable of executing program instructions stored thereon as a monolithic software structure, as standalone software modules, or as modules that employ external routines, code, services, and so forth, or any combination of these, and all such implementations may be within the scope of the present disclosure. Examples of such machines may include, but may not be limited to, personal digital assistants, laptops, personal computers, mobile phones, other handheld computing devices, medical equipment, wired or wireless communication devices, transducers, chips, calculators, satellites, tablet PCs, electronic books, gadgets, electronic devices, devices having artificial intelligence, computing devices, networking equipment, servers, routers and the like. Furthermore, the elements depicted in the flow chart and block diagrams or any other logical component may be implemented on a machine capable of executing program instructions. Thus, while the foregoing drawings and descriptions set forth functional aspects of the disclosed systems, no particular arrangement of software for implementing these functional aspects should be inferred from these descriptions unless explicitly stated or otherwise clear from the context. Similarly, it will be appreciated that the various steps identified and described above may be varied, and that the order of steps may be adapted to particular applications of the techniques disclosed herein. All such variations and modifications are intended to fall within the scope of this disclosure. As such, the depiction and/or description of an order for various steps should not be understood to require a particular order of execution for those steps, unless required by a particular application, or explicitly stated or otherwise clear from the context.
[0100] The methods and/or processes described above, and steps associated therewith, may be realized in hardware, software or any combination of hardware and software suitable for a particular application. The hardware may include a general purpose computer and/or dedicated computing device or specific computing device or particular aspect or component of a specific computing device. The processes may be realized in one or more microprocessors, microcontrollers, embedded microcontrollers, programmable digital signal processors or other programmable device, along with internal and/or external memory. The processes may also, or instead, be embodied in an application specific integrated circuit, a programmable gate array, programmable array logic, or any other device or combination of devices that may be configured to process electronic signals. It will further be appreciated that one or more of the processes may be realized as a computer executable code capable of being executed on a machine readable medium.
[0101] The computer executable code may be created using a structured programming language such as C, an object oriented programming language such as C++, or any other high-level or low-level programming language (including assembly languages, hardware description languages, and database programming languages and technologies) that may be stored, compiled or interpreted to run on one of the above devices, as well as heterogeneous combinations of processors, processor architectures, or combinations of different hardware and software, or any other machine capable of executing program instructions.
[0102] Thus, in one aspect, methods described above and combinations thereof may be embodied in computer executable code that, when executing on one or more computing devices, performs the steps thereof. In another aspect, the methods may be embodied in systems that perform the steps thereof, and may be distributed across devices in a number of ways, or all of the functionality may be integrated into a dedicated, standalone device or other hardware. In another aspect, the means for performing the steps associated with the processes described above may include any of the hardware and/or software described above. All such permutations and combinations are intended to fall within the scope of the present disclosure.
[0103] While the disclosure has been disclosed in connection with the preferred embodiments shown and described in detail, various modifications and improvements thereon will become readily apparent to those skilled in the art. Accordingly, the spirit and scope of the present disclosure is not to be limited by the foregoing examples, but is to be understood in the broadest sense allowable by law.
[0104] The use of the terms “a” and “an” and “the” and similar referents in the context of describing the disclosure (especially in the context of the following claims) is to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the disclosure and does not pose a limitation on the scope of the disclosure unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the disclosure.
[0105] While the foregoing written description enables one of ordinary skill to make and use what is considered presently to be the best mode thereof, those of ordinary skill will understand and appreciate the existence of variations, combinations, and equivalents of the specific embodiment, method, and examples herein. The disclosure should therefore not be limited by the above described embodiment, method, and examples, but by all embodiments and methods within the scope and spirit of the disclosure.
[0106] All documents referenced herein are hereby incorporated by reference. | Methods and systems are provided for identifying a computing device and/or the user of such a device and granting or prohibit access to one or more devices based on the location of the computing device. User devices include receivers and emitters for localization signals, and behavior of user devices or user interaction devices are modified according to received localization signals. Example systems may provide tracking media streaming to local devices, automatic configuration of transmitters, or adaptation of multi-user interactions based on user location. | 8 |
BACKGROUND OF THE INVENTION
Field of the Invention
The invention relates to a device for cross cutting material webs, in particular printed material webs after they have been printed in a rotary printing press.
The published German Patent Document DE 39 34 673 A1 concerns a cross cutting device for moving webs, wherein format length is adjustable. This is particularly suited for a folder disposed downline of a printing press. The cross cutting device is formed of two cylinders of like diameter arranged on opposite sides of the web, one of the cylinders, namely a knife cylinder, carrying at least one cutting knife borne by a cutting beam, and the other cylinder, namely an opposing or counter cylinder, carrying a corresponding number of flexible cutting bars, borne by bearing beams. To be able to cut different format lengths with a single pair of cylinders, the diameter of the knife cylinder is dimensioned so that, for the longest format, the circumferential cylinder speed is equal to or slightly greater (by about 3%) than the web speed, that furthermore each cutting beam and each bearing beam are mounted in the cylinders appertaining thereto so that they are swivellable about swivel axes parallel to the cylinder axes of rotation which lie within the axes of rotation, and that each cutting beam and each bearing beam is swivelled by a swivel mechanism during the cutting operation with adjustable travel (including zero travel for the longest format) periodically counter to the web running direction and subsequently back again into the starting position thereof, about the respective swivel axes thereof in the circumferential direction of the knife cylinder and the opposing cylinder, respectively.
The published European Patent Document EP 05 23 346 B1 concerns a device for transporting a paper web into a folder of a printing press. Applied to the cutting cylinders of a cutting-cylinder pair are material web-profiling strips, which superpose a profile reinforcing the web. The strips are adjoined by smoothening surfaces, which remove the web-reinforcing profile from the web again, the instant the leading end of the material web has entered the conveying device adjoining the pair of cutting cylinders. Smoothening surfaces and profiling strips are applied to the circumferential surfaces of the cylinders contacting the web, the cylinders themselves being formed as rotational bodies of solid material.
The Published Non-prosecuted Japanese Utility Model Application (JP Hei) 2 137 371 is concerned with a cutting device of a folder without puncture needles or pins. In a cutting device of a thus pinless folder, a folding roller having folding blades attached to the outer circumference thereof is freely rotatable. The knife-supporting roller is freely rotatable with respect to the folding roller. A narrow band of flexible material is arranged on the outer circumference of the folding roller and knife-supporting roller in the circumferential direction of the respective roller, alternating in the direction of the rotational axis of the respective rollers.
The published European Patent Document EP 0 523 435 B1 is concerned with a cross cutting device on folding units for web-fed rotary presses. This cross cutting device is formed of a cutting knife, which is rigid against bending and is arranged on a cutting cylinder, and a groove strip or reglet, which is arranged on a groove cylinder as an abutment for separating cut material. The groove reglet is formed of a unipartite groove member and a compression-spring member. Viewed in the direction of movement of the groove cylinder, initially the groove member and then the compression-spring member are arranged adjacent one another. The groove member of the groove reglet is formed of plastic material having low elasticity, whereas the compression spring member is formed of plastic material of higher elasticity compared with that of the groove member.
With regard to folders without pins or puncture needles, it has been known heretofore to cover the circumferential surfaces of the cutting cylinders with an elastic material, which may be adhesively bonded, for example, on the circumferential surfaces thereof. The elastic material has the effect of prestressing the material taken up during the cross cutting operation. The disadvantage of using such adhesively bonded elastic materials is that the surfaces thereof are worn out and abraded very quickly, and the downtime of a folder required for reconditioning the layers is very lengthy. The reconditioning of such elastic layers is also very time-consuming because it is usually very difficult to gain access to the cutting-cylinder pair in a folder.
SUMMARY OF THE INVENTION
In view of the hereinafore outlined disadvantages of the prior art, it is an object of the invention to provide a device for cross cutting material webs wherein the time period required for exchanging cylinder coverings is considerably reduced over the corresponding time period for the devices of the prior art, so that faster resumption of production can be ensured.
With the foregoing and other objects in view, there is provided, in accordance with one aspect of the invention, a device for cross cutting material webs, comprising a cutting-cylinder pair formed of mutually cooperating cylinders having respective cylinder cores and circumferential surfaces formed by exchangeable circumferential elements, the circumferential elements being arranged removably around the respective cylinder cores of the cylinders.
In accordance with another feature of the invention, the cylinder cores have lay surfaces and lay projections.
In accordance with a further feature of the invention, one of the cylinders is a knife cylinder, and the lay projections are arranged on the knife cylinder next to a knife mounting.
In accordance with an added feature of the invention, one of the cylinders is a groove cylinder, and the lay projections are arranged on the groove cylinder adjacent to a groove beam.
In accordance with an additional feature of the invention, the circumferential elements are formed of first circumferential elements and second circumferential elements, the first circumferential elements engaging around the second circumferential elements on the respective cylinder cores.
In accordance with yet another feature of the invention, the first and the second circumferential elements, respectively, are provided separately with a covering portion.
In accordance with yet a further feature of the invention, during assembly of the first and the second circumferential elements on the cylinder cores, respectively, a covering engageable over the first and the second circumferential elements, respectively, is clamped between the cylinder cores, respectively, and the first circumferential elements.
In accordance with yet an added feature of the invention, the first and the second circumferential elements are formed of elastically deformable material.
In accordance with yet an additional feature of the invention, the first and the second circumferential elements are formed of aluminum or an aluminum alloy.
In accordance with another aspect of the invention, there is provided a folder having a cutting-cylinder pair comprising a knife cylinder and a groove cylinder, having first and second circumferential surfaces, respectively, formed by exchangeable first and second circumferential elements arranged removably on the respective cylinder core of at least one of the knife cylinder and the groove cylinder.
In accordance with a concomitant feature of the invention, the folder is of the pinless type.
The advantages which this invention brings with it are of a diverse nature. The exchangeable circumferential elements can be removed simply and quickly from the cutting cylinder region on the folder, so that reconditioning of the covering does not have to be performed in the folder. Consequently, once the circumferential elements have been exchanged, the folder is again available for production. The worn-out circumferential surfaces of the exchangeable circumferential elements can be renewed again outside the folder, without therefore having to exchange the cutting-cylinder pair as a whole.
In a further refinement of the concept upon which the invention is based, the cylinder cores both of the knife cylinder and of the groove cylinder may be provided with lay surfaces and with lay projections in order to achieve easier centering of the circumferential elements. In this regard, the circumferential elements are arranged, in particular, symmetrically with respect to one another. The lay projections on the cylinders are arranged on the knife cylinder alongside the cutting knife mounting and are arranged on the groove cylinder alongside the groove beam. In an advantageous manner, the circumferential elements, which are received near the cutting knife mounting or near the groove beam, grasp the circumferential elements which are disposed opposite to the cutting tool mounting and opposite to the groove beam, respectively, at the ends thereof. In this manner, defined register surfaces and a smooth circumferential surface are attained on the cutting-cylinder pair.
The circumferential elements which are exchangeably fastened onto the cylinder cores may be both provided with portions of a covering, as well as, after mounting, wrapped in a continuous covering material. The ends of the continuous covering material may be clamped between the circumferential elements and the cylinder core and be subjected to tension in the circumferential direction.
The circumferential segments may either be produced entirely from an elastically deformable material or made from aluminum or an aluminum alloy.
The circumferential elements which are exchangeable according to the invention can be used both for cutting-cylinder pairs of folders, generally, or of folders which are pinless or without puncture needles.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a device for cross cutting material webs, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, wherein:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic side elevational view of a folder without puncture needles or pins, having transport surfaces arranged downline of a pair of cutting cylinders; and
FIG. 2 is an enlarged fragmentary view, partly in section, of FIG. 1, showing the cylinder cores of the cutting-cylinder pair, which are complemented with circumferential elements on the circumference thereof and have either a cutting knife mounting support or a groove beam.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the figures of the drawings and, first, particularly to FIG. 1 thereof, there is shown therein a material web 3 , which has been printed on only one or both sides thereof in printing units not otherwise represented in greater detail herein, and is transported by first and second draw-roller pairs 2 and 4 into a folder 1 . Arranged downline of the second draw-roller pair 4 is a cutting-cylinder pair 5 formed of a knife cylinder and a groove cylinder. In a nip of the cutting-cylinder pair 5 , individual copies are cut off from a leading end of the infed material web 3 by a cross cutting operation. The copies are taken up by transport or conveyor belts or tapes 6 and 7 disposed downline of the cutting-cylinder pair 5 , and conveyed further on. The transport belts 6 and 7 travel around deflecting rollers and are provided with tensioning devices; the belts 6 and 7 convey the individual copies to a folding blade cylinder 8 , around the circumference of which, a first belt 6 of the transport belts 6 and 7 is partly wrapped.
The folding blade cylinder 8 is provided, at the circumference thereof, both with grippers 10 and with folding blades 9 , more particularly four folding blades 9 and four gripper bars 10 in the illustrated embodiment, the blades 9 and the gripper bars 10 being offset 90° from one another around the circumference. Due to the fact that the grippers 10 are open at the time of copy transfer, the copies are taken over by the first transport belt 6 and, the instant that a folding blade 9 lies opposite a folding jaw of a jaw cylinder 11 , the back or spine of the copy is pushed into the jaw. After one or more cross foldings have taken place in such a manner, the cross-folded copies are accepted by an upper or lower transporting cylinder 12 , 13 and fed to respective deliveries 14 and 15 for further processing.
In FIG. 2, the cutting-cylinder pair 5 of a pinless folder, i.e., a folder without puncture needles, is reproduced in an enlarged side elevational view of FIG. 1 .
The cutting-cylinder pair 5 is formed of a knife cylinder 16 and a groove cylinder 18 . In contrast with conventionally produced cutting cylinders, in the case of the cutting-cylinder pair 5 according to the invention of the instant application, respective cylinder cores 17 and 19 which are of substantially rectangular construction, are provided with circumferential elements 24 and 27 , respectively. The circumferential elements 24 and 27 have bores 25 formed therein, through which screws 26 or the like extend by which the circumferential elements 24 and 27 are fastenable to the circumference of the respective cylinder cores 17 and 19 . The individual circumferential elements 24 and 27 , respectively, are generally provided with covering portions 20 and 21 , respectively, which take up the respective preceding, leading end of the material web before the cross cutting operation commences. As an alternative to fastening the covering on the circumferential elements 24 and 27 , it would be conceivable for a continuous covering 20 , 21 to be wrapped around the circumferential elements 24 and 27 , respectively, and clamped between the respective circumferential element 24 , 27 and the corresponding cylinder core 17 , 19 .
The cylinder cores 17 and 19 , respectively, which accept the circumferential elements 24 and 27 , respectively, rotate about the respective axes of rotation 22 thereof. Provided on the respective cylinder cores 17 and 19 are a cutting knife mounting 23 and a groove beam 35 , respectively. The cutting knife mounting 23 is formed of a first and a second clamping jaw 23 . 2 and 23 . 3 , respectively, between which the cutting knife 23 . 1 is received. A groove beam 35 , which is formed of hard rubber or similar material and cooperates with the cutting knife 23 . 1 , is set into the groove cylinder 18 of the cutting-cylinder pair 5 . To simplify and speed up the assembly, the individual circumferential elements 24 and 27 , respectively, may be screwed or threadedly secured together with the cylinder cores 17 and 19 , respectively.
In the region of the cutting knife mounting 23 and the groove beam 35 , the cylinder cores 17 and 19 have lay projections 29 and 31 . In addition to the latter, the cylinder cores 17 and 19 are provided with lay surfaces 28 . The fact that lay projections 29 and 31 and lay surfaces 28 and 30 are provided on both cylinders 16 and 18 , respectively, allows the circumferential elements 24 to be positioned extremely accurately, because two lay surfaces are available. By exact alignment of the circumferential elements 24 on the circumference of the cylinder cores 17 and 19 , precise register surfaces are created for the circumferential elements 27 , because the end regions of the circumferential elements 24 engage over the ends of the circumferential elements 27 . This applies both to the knife cylinder 16 and to the groove cylinder 18 of the cutting-cylinder pair 5 . With respect to either the cutting knife mounting 23 and the groove beam 35 , the circumferential elements 24 and 27 are arranged symmetrically relative thereto. To ensure easy accessibility of fastening screws 26 to the circumference of the cylinder cores 17 and 19 , the respective covering 20 , 21 does not extend continuously over the entire width of the two cylinders 16 and 18 , but instead, annular interruptions are provided in the coverings 20 and 21 , ensuring that the fastening screws 26 are easily accessible. Instead of the fastening screws 26 , other standard parts can of course also be used for fastening the circumferential elements 24 and 27 to the respective cylinder cores 17 and 19 .
The circumferential elements 24 and 27 , which can be exchangeably mounted in pairs per cylinder core 17 and 19 , respectively, may be made from an elastically deformable material; it would also be conceivable for them to be made from aluminum or an aluminum alloy. After removal of the circumferential elements 24 and 27 from the corresponding cylinder cores 17 and 19 , the surfaces thereof can be reconditioned. Because this can occur outside the folder, the latter can go back into production after mounting a further, as yet unused, set of circumferential elements 24 and 27 . The worn-out set of circumferential elements 24 and 27 , respectively, can be reconditioned outside the machine until the circumferential elements 24 and 27 which are in use become worn out and themselves need exchanging in order to ensure cutting quality.
In addition to providing the cylinder cores 17 and 19 , respectively, with the circumferential elements 24 and 27 according to FIG. 2, i.e., four circumferential elements 24 and 27 , respectively, for each cylinder core 17 , 19 , it is likewise conceivable for cylinders of greater diameter to be provided with exchangeable circumferential elements 24 and 27 . Although a cutting-cylinder pair 5 with cylinders of a single diameter is represented in FIG. 2, it is entirely possible for the invention also to be transferred to cylinders having a plurality of cutting knives or groove beams with approximately double or triple the diameter. The invention is suitable wherever a surface of cylinders exposed to wear has to be reconditioned without having to remove the entire cylinder from the printing press. Such cylinders may be sheet-guiding cylinders, storage drums, reversing or turning drums or else folding blade cylinders, jaw cylinders or the like in rotary printing presses and folders, respectively.
The circumferential elements 24 and 27 , respectively, can also be fastened to the circumference of the cylinder cores 17 and 19 by register pins or other adjusting elements; the positions of the lay projections 29 and 31 , respectively, arranged in the illustrated embodiment next to the cutting knife mounting 23 and the groove beam 35 , respectively, may also be provided at other positions on the cylinder cores 17 and 19 . Apart from the approximately square construction that is represented, it is also conceivable for the cylinder cores 17 and 19 themselves to have a triangular cross section, somewhat for receiving three circumferential elements on the circumference thereof, the outer surface of which then providing a continuous outer cylindrical or jacket surface. Stationary elements received on the circumference of a cylinder, such as the cutting knife mounting 23 or groove beam 35 , for example, may similarly be integrated into the exchangeable circumferential elements 24 and 27 , so that they are likewise exchangeable. In this manner, various cutting formats could be created by changing the cylinder geometry, just as different covering materials 20 and 21 on the circumferential surfaces 24 and 27 produce different cutting characteristics. Apart from the selection of the material with regard to Shore hardness and modulus of elasticity, the covering 20 , 21 can also be modified with regard to the thickness of the covering. Thereby, the holding forces acting, before the cutting, upon the material webs 3 which are to be cut, can be set and adapted to the thickness of the material web 3 . | A device for cross cutting material webs includes a cutting-cylinder pair formed of mutually cooperating cylinders having respective cylinder cores and circumferential surfaces formed by exchangeable circumferential elements, the circumferential elements being arranged removably around the respective cylinder cores of the cylinders. | 1 |
FIELD AND BACKGROUND OF THE INVENTION
The present invention relates to a precontrolled three-way pressure reduction valve having a hollow piston separating a working liquid space from a control liquid space.
These pressure reduction valves readily tend to oscillate, so that special measures must be taken in order to stabilize them. The connecting openings between the surrounding groove of the control piston and the working liquid space are provided in large number over the circumference and arranged in two rows so that a good distribution of the working liquid from the groove into the working liquid space which is in communication with the consumers, and vice versa, is assured. This requires a considerable expense for the manufacture of the control piston, which is developed as hollows piston having a partition.
SUMMARY OF THE INVENTION
The object of the present invention is to obtain, at little cost of manufacture, a pressure reduction valve which operates substantially free of oscillation. This is surprisingly achieved by providing a working liquid space located in the control piston and having a T-shape with axial and transverse bores, there being a groove encircling the control piston and communicating with the transverse bore. Due to the fact that the working liquid space is developed as a T-channel, excessive eddying of the work liquid in this space is substantially prevented, so that a high degree of stability during the control process can be obtained as a result of this specific guidance of the working liquid. Furthermore, the stability of the control process is additionally favored by the special development of the damping choke which is arranged in front of the precontrol valve. The development of the T-channel of the working liquid space formed by the main control piston requires merely a longitudinal bore which debouches into a transverse bore.
BRIEF DESCRIPTION OF THE DRAWING
With the above and other objects and advantages in view, the present invention will become more clearly understood in connection with the detailed description of a preferred embodiment, when considered with the accompanying drawing in which the sole FIGURE is an axial section through a precontrolled three-way pressure reduction valve according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The precontrolled three-way pressure reduction valve developed in cartridge form has a sleeve 1 which forms the housing and which is screwed by a thread la in liquid-tight manner by means of a sealing ring 32 into an internal thread in a receiving housing 31. This receiving housing 31 has channels 33 and 34 which are in liquid communication with circumferential grooves 36 and 37 in the sleeve-shaped housing 1. The channel 33 communicates with the pump connection, and the channel connection 34 communicates with the tank connection. The circumferential grooves 36 and 37 are separated from each other by a sealing rib 40 with sealing ring 41. The other sealing ring 43 seals the circumferential groove 36 off from the consumer connection 45. The bore portion 46 of the housing sleeve 1 is developed as cylindrical guide for the control piston 47. The control piston has a partition 48 which separates the working liquid space 49 from the control space 50. In the central region, the partition wall has a throttle bore 51 through which control liquid flows from the working liquid space 49 into the control space 50. The working liquid space 49 is developed in T-shape, consisting of a transverse bore 53 which an axial bore 54 debouches. The transverse bore 53 debouches into a surrounding groove 56 the limiting walls 56a, 56b of which form control edges which cooperate with radial bores 58 and 59 in the housing sleeve 1. In the case of the present embodiment, six radial bores 58 and six radial bores 59 are, for instance, arranged distributed uniformly on the circumference of the sleeve 1. The radial bores 58 are in communication with the surrounding groove 36 which, in its turn, communicates with the pump channel 33. The radial bores 59 debouch into the surrounding groove 37 which, in its turn, communicates the tank channel 34.
In the position of the control piston shown, the consumer connection 45 is connected via the T-shaped cavity 53, 54 of the surrounding groove 56, the radial bores 58 of the surrounding groove 36 with the pump channel 33. Via the choke bore 51 in the partition 48 of the control piston, the same pressure acts in the control space 50 as in the working liquid space 49. This pressure now acts on its part via a damping choke 60 on the closure member 61 of the precontrol valve VV. The closure member 61 is of spherical shape and is pressed via the cup spring 63 by the compression spring 64 onto the seating surface 65. The initial tension of the compression spring 64 is set by the hollow screw-in member 67 against which the one end of the compression spring 64 rests. The screw-in member 67 has a screw thread 68 which engages into an internal thread 69 of the housing sleeve 1 in form-locked and force-locked manner. The adjustment of the initial stress which is established by the depth of insertion of the screw-in member is fixed by the lock nut 70 which is threaded on another thread 71 of the screw-in member 67 and is pulled firmly against the upper end surface 73 of the housing sleeve 1. The valve space or spring space 75 of the precontrol valve is connected, via an obliquely extending channel 76, in the housing sleeve 1 with the tank channel 34 of the receiving housing 31. The valve space 75 is sealed off from the outside by packing rings 77. A hood 80 protects and secures the screw-in member 67 against external influences.
The damping choke 60 provided between precontrol valve VV and control space 50 is developed as screw-in member having a cylindrical head part 60a. The choke bore has a T-shaped course and is formed by a transverse bore 60b in the head part 60a and axial bore 60c. Before the control liquid strikes the closure member 61, the liquid is deflected 90 degrees by the T-shaped development of the choke bore and a further damping effect is thus obtained. This damping effect is further favored by the fact that the control liquid must first of all pass through the annular space 58a between the head part 60a of the damping choke and the limiting wall 50b of the control space 50 before it enters into the transverse bore 60b of the damping choke. An additional damping effect is obtained by a spring end 8a of the compression spring 8 which acts on the control piston 47 in the direction of the connection 45 and lies in said annular space 58, thus additionally constricting said space.
As soon as the opening pressure of the precontrol valve VV which has been set on the compression spring 64 is reached, the closure member 61 lifts off from its seat surface 65 against the force of the spring 64 and establishes a connection, via the damping choke 60, between control space 50 and valve space or spring space 75 of the precontrol valve. The control liquid which thus flows into the valve space 75 is fed back via the channel 76 to the tank channel 34. As soon as the precontrol valve VV opens and the pressure in the working liquid space 49 increases further, the control piston 47 moves in the direction of the control space 50 until the control edge 56a of the surrounding groove connects the working liquid space 49 with the radial bores 59 which are connected via the tank channel 34 to the tank. By this connection, sufficient working liquid is conducted to the task through the working liquid space 49 on the consumer side until the pressure corresponds to the pressure set on the precontrol valve VV. As soon as this pressure is reached, the precontrol valve closes and, by the pressure equality which is again established on the control piston via the choke bore 51, the control piston is shifted again by the slight force of the control spring 8 acting on it in the direction of the consumer connection 45 and thereby interrupts the connection between working liquid space 49 and the radial bores 59 which are in communication with the tank. The axial spacing of the control edges 56a, 56b is slightly less than the axial spacing of the radial bores 58, 59, so that when the pressure set on the precontrol valve is reached the control piston lies with the surrounding groove 56 between the two rows of radial bores. As soon as a change in pressure on the consumer side takes place, the control piston 47 moves in either the one or the other direction and, via the control edges 56a, 56b, connects the consumer side 45 via the radial bores 58, 59 in the housing sleeve 1 either with the tank (in the event of an increase in pressure) or with the pump (in the event of a decrease in pressure). During this control process, no substantial oscillations of the control piston 47 occur, since pressure peaks occurring on the computer side are substantially intercepted by the special development of the control piston and of the damping choke, and the precontrol range is thus not first reached.
The amount of control liquid discharging to the tank during the control process via the control space 50 as well as the valve space 75 and the connecting channel 76 is determined by the size of the cross section of the choke bore 51. In order to prevent the danger of dirtying, the nozzle or the choke bore 51 has a diameter of about 0.7 mm, while the damping choke 60 has a diameter of about 0.9 mm. | A precontrolled three-way pressure reduction valve having essentially vibration-free operation is encased in a cartridge and has a hollow control piston wherein a working fluid space is formed as a T-shaped cavity within the control piston. In the cavity, there are axial and transverse bores of approximately the same diameter. A groove encircles the control piston, and has a width which is slightly larger than a diameter of the transverse bore, the transverse bore communicating with the groove. | 8 |
[0001] The present invention relates to a method of vaccination comprising the step of administering at a mucosal site a composition comprising a carbohydrate polymer and an antigen. It also relates to a composition used in the vaccination and to a vaccine adapted for administration at a mucosal site.
BACKGROUND OF THE INVENTION
[0002] Most infectious agents enter the body through mucosal membranes, and recent vaccine strategies have concentrated on the production of antibodies at these sites to block their entry. The stimulation of secretory immune responses, which includes mucosal IgA, the predominant antibody isotype in mucosal secretions with the capability to neutralise bacteria, bacterial products and viruses, is considered to be crucial to vaccine development [1-4]. Currently most vaccines delivered by injection are not efficient at inducing a mucosal response.
[0003] At present the oral polio vaccine remains the only successful large-scale vaccine that gives protection at the mucosal level. It is a live vaccine whose attenuation was achieved empirically with the attendant risks of back-mutation. In contrast, immunisation with defined protein antigens would have many advantages, including safety in immunosuppressed individuals. However, before such vaccines can be developed there is a need for adjuvants and delivery systems to overcome the problems associated with mucosal vaccination using defined protein antigens, including poor immunogenicity or the induction of tolerance.
[0004] Bacterial enterotoxins such as cholera toxin (CT) produced by Vibrio cholerae , and labile toxins from Esherichia coli have been co-administered with antigens and act as adjuvants with antigens [5,6]. However, these adjuvants pose health risks due to their toxic properties, and for the most part, cannot be used in human trials, and have limited usefulness for human vaccination. With regard to cholera toxin, Wiedermann, John-Schmid and Lindblad et al [7] showed that the tolerogenic or immunogenic properties for the B subunit of cholera toxin depended on the nature of the antigen/allergen to which it is coupled. Thus, in addition to its toxicity, CT suffers from a major disadvantage in that it may not be effective as an adjuvant, but rather, lead to tolerance.
[0005] In other studies, a genetically modified, detoxified form of the heat-labile toxin of enterotoxigenic E. coli (LT(Rl92G)) was used intranasally in mice together with C. albicans (a fungus which causes “Thrush”), and protection against C. albicans infection was indicated [8].
[0006] Vaccines containing DNA encoding the antigen and low-viscosity carboxymethylcellulose sodium salt (CMCS-L) as a vehicle to carry the DNA to its site of action have been studied [9]. Lipids, such as monophosphoryl lipid A (CMPL) [10] which presumably aids in uptake of the antigen by the mucosal cell membrane, have also been used. However, the usefulness of these as adjuvants is unclear.
[0007] Adjuvants which have been administered with immunogens via the mucosa have therefore consisted of potentially dangerous bacterial or viral derivatives and display variable degrees of adjuvanticity.
[0008] The development of efficacious mucosal vaccines has further been hindered by incomplete understanding of mechanisms of pathogen transmission, and the immune responses specific to each pathogen. For example, development of a potent mucosal HIV vaccine has been affected by lack of understanding of mucosal HIV infection, and the immune responses that control the infection. There are studies which show that passive administration of IgG can confer protection against HIV infection at a mucosal site. However, the protection is limited, in that it appears unlikely that the protection is totally via neutralisation of the initial cell infection. It seems more likely that neutralisation at secondary lymphoid sites are important in controlling pathogen transmission via the mucosa [11]. Thus, many different approaches have been tried, to induce mucosal immunoglobin based immunity—like by immunising systematically and by immunising at a mucosal site. In most cases, the approaches have failed and are either toxic, or do not give rise to efficacious and practical immunoglobin based immune response.
[0009] Mannan, a polymannose or polysaccharide derived from the cell wall of yeast, when oxidised and conjugated to human Mucin 1 (an overexpressed cancer antigen) has been used in mice to induce immune responses [12, 13]. Intraperitoneal immunisation resulted in the induction of cellular immune responses as shown by production of CTLs and their precursors, Th1 cytokines IFN-γ and IL-12. Antibody production was usually low. In tests in more than 100 patients, mannan has not shown any obvious toxicity or autoimmunity [14].
[0010] Mannose receptors which bind mannan have so far been identified on macrophages and dendritic cells. Oxidised mannan has been shown to stimulate production of interleukin 12 in macrophages, and also to stimulate T-cells, and to cause rapid trafficking of antigens to the class I pathway to produce cytotoxic T-cells in mice [15].
[0011] Surprisingly the inventors have discovered that if mannan is administered via a mucosal site beneficial immunogenic effects are produced.
SUMMARY OF THE INVENTION
[0012] In a first aspect, the invention relates to a method of immunising a subject, comprising the step of administering a composition comprising:
an antigen; and a carbohydrate polymer comprising mannose to a mucosal site.
[0015] The immunisation preferably results in a humoral or cellular immune response. Preferably, it results in a humoral response. More preferably, it results in a humoral response wherein one or more of IgA, IgG, IgM and optionally, IgE antibody production is stimulated. In some instances, stimulation of IgE production may be beneficial, eg to immunise against worm infections.
[0016] In other instances, a reduction in total IgE production, or a reduction in the level of IgE relative to other antibody classes, can be beneficial, e.g. to prevent or reduce type I hypersensitivity or atopy, e.g. hayfever, asthma attacks or food and other allergies. IgE binding to its receptor and subsequent cross-linking with allergen is responsible for triggering immune responses underlying conditions such as asthma including atopic asthma, allergic rhinitis and atopic dermatitis, which are health problems of epidemic proportions. Thus, in one embodiment, the immune response is such that IgE production is reduced. In another embodiment, the IgE titre relative to one or more of IgA, IgG, IgM or subclasses of these is reduced. IgE production may be unchanged, or be substantially unchanged, whilst the production of one or more of the other antibodies is increased upon immunization with the composition.
[0017] Most preferably, IgA production is stimulated, and the titre of IgA at one or more mucosal areas, and/or in the serum, is increased. In one embodiment, IgA production upon immunization is greater when compared with production of IgG, IgM and IgE. In a preferred embodiment, the immunisation selectively stimulates production of one or more of IgA, IgG and IgM over IgE. The immunoglobulins may include, one or more of the subclasses within each class of antibody, for instance IgG2a and IgG1. Thus, in another preferred embodiment, immunization results in greater production of IgA relative to the increase in IgG1 and/or IgG2a production. The levels of antibody may be increased in serum or at mucosal sites, or both.
[0018] The subject immunised may be a human or an animal. For example the invention may be used to prevent and/or treat animal diseases. Thus, the antigen may be any pathogen known to cause diseases or infections in any animal species that include but are not limited to farm animals such as pigs, cattle, sheep, horses, and domestic animals and/or household pets such as cats and dogs, exotic animals such as zoo animals and feral animals. The antigen may also be an antigenic part of any of the pathogens. The types of infections or diseases that may be prevented or treated in accordance with the invention include but are not limited to those described in “Hagen and Bruner's Microbiology and Infectious Diseases of Domestic animals: with reference to etiology, epizootiology, pathogenisis, immunity, diagnosis and antimicrobiol susceptibility”, W A Hagen, Comstock Pub. Associates, 1988, which is incorporated herein in its entirety by this reference.
[0019] In a second aspect, the invention relates to a method of immunising a subject comprising the step of administering a composition comprising:
an antigen; and a carbohydrate polymer comprising mannose to a mucosal site thereby to stimulate a secretory immune response.
[0022] The secretory immune response is preferably IgA immune response at one or more mucosal sites. Stimulation of secretory immune responses at these sites is particularly advantageous, as it can assist in neutralisation of pathogens or infectious agents upon their entry into the body through mucosal membranes.
[0023] The mucosal site may be a region or any area, from any mucosal surfaces, e.g. those lining the oral cavity or tissues, including the teeth and gingivae, those lining the gastrointestinal tract, or those lining the nasal passages and lungs, and the reproductive tract/tissues. The conjunctiva of the eyes also provides a suitable surface for administration of the composition. Examples of mucosal sites or surfaces include but are not limited to the respiratory tract such as the nasal region (e.g. the nose), the trachea, bronchi and the lungs, the buccal or oral tissues including the oral (e.g. the mouth and gingivae) and oro-pharyngeal cavities, the throat including the tonsils, the gastrointestinal tract (e.g. oesophagus, stomach, duodenum, small and large intestines, colon and rectum). An increase in antibody production in the male and female urinary and reproductive tracts is also contemplated and includes but is not limited to the bladder, ureter, urethra and associated tissues, the penis, the vulva/vagina and cervico-vaginal tissues, as well as the uterus and fallopian tubes.
[0024] Preferably, antibody production is increased in the respiratory tract such as the nasal region (e.g. the nose), the trachea, bronchi and the lungs, the buccal or oral tissues including the oral (e.g. the mouth and gingivae) and oro-pharyngeal cavities, the throat including the tonsils, the gastrointestinal tract (e.g. oesophagus, stomach, duodenum, small and large intestine, colon and rectum). An increase in antibody production in the male and female urinary and reproductive tracts is also contemplated and these include but is not limited to the bladder, ureter, urethra and associated tissues, the penis, the vulva/vagina and cervico-vaginal tissues, as well as the uterus and fallopian tubes. In a particularly preferred embodiment, the titre of IgA upon immunization is increased in a mucosal region selected from the group consisting of the lungs, nasal region, throat, gut, and male and female urinary and reproductive tracts. In another embodiment, the titre of one or more of IgA, IgG, IgM and, optionally, IgE is increased. In yet another embodiment, the level of one or more of IgA, IgG or IgM is increased to a greater degree than IgE. The immunoglobulins may include one or more sub-classes within each class of antibody.
[0025] In a further embodiment, the titre of IgA is increased upon immunization, to a greater degree than increases in IgG and IgM. Preferably, the increase in serum IgA upon immunization is greater than the increase in IgG1 and/or IgG2a.
[0026] In a third aspect, the invention relates to a method of modulating an immune response at a mucosal site in a subject, comprising the step of administering a composition comprising:—
an antigen; and a carbohydrate polymer comprising mannose to a mucosal site.
[0029] The immune response is preferably modulated so that antibody production, in response to administration of the composition, is selected from the group consisting of IgA production, IgG production, IgM production and IgE production. The immune response may also be modulated by selectively inducing a desired type of antibody response, for example, by increasing its level of production so that a greater amount is produced when compared with another class or subclass of antibody. In one embodiment, the immune response is modulated by inducing an increase in production of one or more of IgA, IgG and IgM relative to that of IgE. More preferably, the immune response is modulated by increasing production of IgA relative to that of IgG, IgM and/or IgE. Most preferably, the immune response is modulated such that IgA production is increased relative to the production of IgG, particularly IgG1 and/or IgG2a. The immune response may also be modulated by inducing production of antibodies whose presence in turn modulates response to other classes of antibodies. In a preferred embodiment, the immune response is modulated such that production of one or more of IgA, IgG1, IgG2a or IgM attenuates or inhibits the action of IgE. In another embodiment, the production of one type of antibody stimulates the action of another class of antibody.
[0030] Alternatively the immune response is preferably modulated so that mediators of cellular immunity are stimulated, such as Th1 and/or Th2.
[0031] In yet another embodiment, the mucosal or secretory immune response is stronger than the systemic immune response. In a preferred embodiment, the secretory immune response is an IgA response, and the systemic immune response is IgG response.
[0032] The antigen which evokes the immune response may include and is not limited to all or immunogenic portions of pollens, allergens especially those that induce asthma, bacteria, viruses, yeasts, fungi, protozoa and other microorganisms, or pathogens of human, animal or plant origin. Derivatives of these antigens are also contemplated and may be homologues, analogues, conjugates or salts of such entities.
[0033] In a preferred embodiment, the antigen is selected from the group consisting of influenza virus, haemagglutinin of influenza, Porphyromonas gingivalis (which causes gum disease and cardiovascular disease), proteinase and adhesin epitopes of Porphyromona gingivalis, Helicobacter pylori , urease of Helicobacter pylori , rotavirus, recombinant outer capsid proteins of rotavirus, HIV, gp120 of HIV, RSV, surface proteins of RSV, antigens from microorganisms which cause venereal disease and ovalbumin peptides.
[0034] Other antigens or antigenic portions or derivatives thereof may also be used in accordance with the invention. These include but are not limited to Listeria monocytogenes, Mycobacterium tuberculosis , BCG, Mycobacterium avium, M. avium hsp65, influenza nucleoprotein, Respiratory Syncyticial virus (RSV) F or G proteins, HIV, Candida especially Candida albicans and Chlamydia trachomatis or outer membrane proteins thereof, Neisseria meningitidis class 1 outer protein, Herpes simplex virus type I glycoprotein G or gp D or CP27, Human Papilloma Virus antigen E7, Porphyromonas gingivalis Cpx, Murray valley encephalitis virus E glycoprotein, antigenic portions thereof and derivatives thereof. Antigens selected from the group consisting of those pathogens which cause the common cold, those which cause chlamydia, from Streptococcus , from Staphylococcus may also be used in accordance with the invention. Antigens corresponding to, or derived from, the organisms disclosed in “Medical Biology, a Guide to Microbial Infections: Pathogenesis, Immunity, Laboratory Diagnosis and Control”, D Greenwood, R Slack and J Peutherer (eds), 15 th edition, Churchill Livingston, Edinburgh, 1997, incorporated in its entirety herein by this reference, are also contemplated.
[0035] In another embodiment of the invention, the antigen is selected from the group consisting of Listeria monocytogenes, Mycobacterium tuberculosis, Chlamydia trachomatis, Chlamydia pneumoniae , outer membrane proteins thereof, antigenic portions thereof, derivatives thereof, and synthetic peptides based on epitopes from these organisms. In one embodiment, the antigen is selected from the group comprising the 19 kDa lipoprotein of M. tuberculosis , hsp-65 of M. avium , VP5 of rotavirus, E7 of HPV and Cpx of P. gingivalis.
[0036] A selected antigen may form part of a fusion protein in order to facilitate expression and purification on production of the fusion protein in recombinant host cells. The non-antigen portion of the fusion protein would generally represent the N-terminal region of the fusion polypeptide with the carboxy terminal sequences comprising antigen sequences. Fusion proteins may be selected from glutathione-S-transferase, β-galactosidase, or any other protein or part thereof, particularly those which enable affinity purification utilising the binding or other affinity characteristics of the protein to purify the resultant fusion protein. The protein may also be fused to the C-terminal or N-terminal of the carrier protein. The nature of the fusion protein will depend upon the vector system in which fusion proteins are produced. An example of a bacterial expression vector is pGEX which on subcloning of a gene of interest into this vector produces a fusion protein consisting of glutathione-S-transferase with the protein of interest. Examples of other vector systems which give rise to fusion proteins with a protein of interest are described in Sambrook et al, “Molecular Cloning: A Laboratory Manual”, Cold Spring Harbor Press, Cold Spring Harbor, USA, 1989, incorporated herein in its entirety by this reference.
[0037] Alternatively synthetic peptides or epitopes, optionally coupled to a protein carrier may be used in the invention. Synthetic peptides or epitopes may be produced in accordance with standard methods.
[0038] The carbohydrate polymer comprising mannose is most preferably a carbohydrate polymer containing mannan. In a preferred embodiment the antigen is conjugated to oxidised mannan in a similar manner to that described in WO 95/18145. The mannan is preferably isolated from cell wall of yeast, and may be oxidised using reagents such as sodium periodate to produce a polyaldehyde which is then directly reacted with a selected antigen. Reduced mannan may also be used and a composition containing this may be prepared by adding sodium borohydride to an oxidised mannan-antigen conjugate.
[0039] In one embodiment polysaccharide chains may be first activated with cyanogen bromide and the activated polysaccharide then reacted with a diamine, followed by conjugation to the antigen to form a conjugate which may optionally then be oxidized. The carbohydrate and polypeptide may be derivatized with bifunctional agents in order to cross-link the carbohydrate and polypeptide. Commonly used cross-linking agents include 1,1-bis(diazoacetyl)-2-phenylethane, glutaraldehyde, N-hydroxysuccinimide esters, for example, esters with 4-azidosalicyclic acid, homobifunctional imidoesters including disuccinimidyl esters such as 3,3′-dithiobis(succinimidyl-propionate), and bi functional maleimides such as bis-N-maleimido-1,8-octane. Derivatizing agents such as methyl-3-[(p-azido-phenyl)dithio] propioimidate yield photactivitable intermediates which are capable of forming cross-links in the presence of light. Oxidised carbohydrates may be reacted with hydrazine derivatives of antigens to give a conjugate. Alternatively, carbohydrates may be reacted with reagents such as carbonyl diimidazole, which after oxidation gives the desired conjugate.
[0040] The coupling of antigens to carbohydrate involves converting any or all of the functional groups on the carbohydrate to reactive groups and thereafter reacting the reactive groups on the carbohydrate with reactive groups on the polypeptide. Carbohydrate polymers are replete with hydroxide groups, and in some instances, carboxyl groups (such as in iurodinate), ester groups (such as methylgalacturonate) and the like. These groups may be activated according to standard chemical procedures. For example, hydroxyl groups may be reacted with hydrogen halides, such as hydrogen iodide, hydrogen bromide and hydrogen chloride to give the reactive halogenated polysaccharide. Hydroxy groups may be activated with phosphorous trihalides, active metals (such as sodium ethoxide, aluminium isopropoxide and potassium tert-butoxide), or esterified (with groups such as tosyl chloride or acetic acid) to form reactive groups which can be then be reacted with reactive groups on the polypeptide to form one or more bonds. Other functional groups on carbohydrates apart from hydroxyl groups may be activated to give reactive groups according to well known procedures in the art.
[0041] Without wishing to be bound by any proposed mechanism for the observed advantages of the invention, it is thought that the mannan not only acts as an adjuvant, but is also a potent mucosal adjuvant by virtue of increased or efficient uptake via the mucosa.
[0042] The mucosa is as described above, and includes the mucosal surfaces of the respiratory tract such as the nasal region and the lungs, the GI tract such as the buccal or oral and oro-pharyngeal cavities, throat, tonsils and gut, the rectal tissues, and the male and female urinary and reproductive tracts including the cervico-vaginal tissues.
[0043] In a fourth aspect, the invention provides a composition adapted to be administered at a mucosal site thereby to generate an immune response, the composition comprising an antigen and a carbohydrate polymer comprising mannose. Preferably, the antigen, carbohydrate polymer and immune response are as described above. These antigens and carbohydrates are also preferably treated in the manner described above to form the composition.
[0044] The composition is preferably formulated for administration at a mucosal site by inhalation of the composition which is sprayed into the nasal region. However, it may also be administered by absorption of droplets or fluid placed on or applied to, one or more mucosal sites such as regions of the mouth, tongue, throat, the gut including the stomach, the nasal and respiratory passages including the lungs, the reproductive tract including the vagina and cervix, and the rectum. Application of the composition may also be by rubbing or massaging it onto one or more accessible mucosal areas. The composition may also be placed in a slow- or time-release device such as a capsule or a suppository (e.g. those based on alginate microspheres, poly(lactide-co-glycolide) or collagen polymers) which may be inserted, for instance, in the rectum. It may also be administered by injection into a mucosal site as indicated above. The composition may also be formulated in accordance with the relevant methods set out in Remington's Pharmaceutical Sciences, Mack Publishing Co., Easton, Pa., USA, incorporated herein by this reference. The composition is most preferably used to vaccinate a subject in need thereof via a mucosal site. The immune response is preferably a response as described above.
[0045] Thus in a fifth aspect, the invention relates to a vaccine to be administered at a mucosal site, comprising a composition as described above.
[0046] In a sixth aspect, the invention relates to a method of vaccinating a subject, comprising the step of administering at a mucosal site a vaccine comprising a composition as described above.
[0047] The composition or vaccine in accordance with the invention is preferably administered via a mucosal site to human or animal patients to protect against various disease states including diseases or infection of the eyes such as trachoma or conjunctivitis, listeriosis, tuberculosis, influenza, colds, respiratory diseases, sexually transmitted diseases or infections by viruses, bacteria, fungi, protozoa, or other microorganisms or pathogens.
[0048] Administration or vaccination may be as described above, or may be a single or multiple event, or may be part of a prime-boost protocol, a combination of these, or each of these with other, conventional methods of vaccination. The prime-boost protocol may, for example, comprise priming by intramuscular administration, and boosting by intranasal administration. The prime-boost may, in addition to the composition of the invention, include DNA, viruses (eg vaccinia) or other immunogenic peptides or molecules, including the antigens described above. One or both of the priming and boosting composition may include the composition of the invention, namely, an antigen and a carbohydrate polymer comprising mannose. Thus, in a prime-boost protocol, one of the events may include the composition in accordance with the invention, while the other may omit the carbohydrate polymer containing mannose.
[0049] Other methods that may be used include but are not limited to injection via the rectum, the oral cavity, or rubbing of the vaccine onto a mucosal surface or site. The amount and frequency may be determined by an attending physician or veterinarian. By way of example, 1 μg to 10,000 μg/kg may be administered to a subject, preferably 5 μg to 5000 μg/kg, more preferably 8-1000 μg/kg and most preferably 400-600 μg/kg. Even more preferably a dose of 100-200 μg/kg is contemplated particularly for humans.
[0050] The compounds or vaccines of the invention may also be administered to subjects in conjunction with other immune regulators that lend themselves to efficacious administration via the mucosa.
[0051] Other adjuvants, pharmaceutically acceptable carriers, diluents or auxiliaries which may enhance the immunogenicity or effectiveness of the composition or vaccine of the invention may also be included therein, or be co-administered therewith. For instance, lipofectamine may be co-administered with the composition or vaccine of the invention.
[0052] The composition or vaccine may be formulated in accordance with the manner in which it is to be administered. For example, it may be formulated for inclusion in a spray-container, aerosol can or nebuliser for administration by inhalation. Or it may be formulated as a solution or liquid to be added dropwise or as droplets to a mucosal site, e.g. the oral cavity or throat for absorption. Nose-drop formulations, liposomal formulations, slow-release formulations, capsules or devices, or formulations comprising DNA are also contemplated.
[0053] The invention may be used to protect or treat animal and/or human subjects. Thus, in one embodiment, the invention provides a method of vaccinating a subject against Chlamydia comprising the step of administering a composition as described above. Preferably the antigen is outer membrane protein of C. trachomatis and the method is used in the treatment or prophylaxis of trachoma.
[0054] In another embodiment, the invention provides a method of immunising a subject with BCG, comprising the step of administering a composition as described above, wherein the antigen is BCG, or purified or recombinant preparations thereof. In a preferred embodiment, the subject is an animal such as a possum.
[0055] In a seventh aspect, the invention provides a method of sterilising a non-human subject, comprising the step of administering a composition comprising:
an antigen; and a carbohydrate polymer comprising mannose to a mucosal site.
[0058] In one embodiment, the antigen is derived from sperm and administration of the composition results in production of antibody against sperm thereby to prevent fertilisation of an egg. The antibody is preferably IgA.
[0059] In another embodiment, the antigen is derived from the egg and induces production of antibodies against the zona pellucida preventing maturation of an embryo. The antibody is preferably IgA. Such methods may be used in controlling fertility of subjects such as animals that kill native wild life, e.g. foxes, or animals that destroy natural vegetation, or that compete with livestock for food, e.g. rabbits. Populations of animals that are a reservoir for undesirable diseases, e.g. possums, which carry or act as a reservoir for tuberculosis, may also be controlled using the invention.
[0060] The present invention is advantageous in that it stimulates an effective immune response in a non-invasive manner. For example, animals such as native species in danger of extinction due to diseases may be vaccinated by administering nasal droplets of an immunogenic composition in accordance with the invention. Non-invasive administration could also be achieved by use of aerosols or nebulisers, and are also likely to increase compliance in humans, particularly children.
[0061] The invention also extends to use of the composition described above in the manufacture of a medicament for modulating an immune response in a subject and use of the composition in the manufacture of a vaccine suitable for administration to a mucosal site.
DESCRIPTION OF THE INVENTION
[0062] Preferred embodiments of the invention will now be described with reference to the following, non-limiting examples, in which:—
[0063] FIG. 1 shows the results of intranasal versus intraperitoneal immunisation: (CBAxBALB/c) F1 mice were immunised on days 0, 10, 17 with 12 μg of M-LLOFP intranasally or intraperitoneally, and serum was obtained from individual mice on day 24. Antigen specific IgA ( FIG. 1 a ) and IgG1 ( FIG. 1 b ) were detected by ELISA and optical density was measured at 450 nm. Closed squares (▪) indicate intranasally immunised mice, open circles (◯) intraperitoneally immunised mice and open triangles (Δ) the unimmunised controls. Results for individual mice are shown.
[0064] FIG. 2 shows subclasses of antibody in the serum of M-LLO.FP immunised mice. (CBAxBALB/c) mice were immunised intranasally with 12 μg of M-LLO.FP or unconjugated LLO.FP on day 0, 10 and 17 and serum from 5 individual mice obtained on day 24. Antigen specific IgA (a), IgG1 (b) and IgG2a (c) was detected by ELISA. Individual titres are shown as dot plots, with corresponding symbols for different antibody classes from the same mouse. In addition, titres were converted to geometric means (heavy bar) and standard deviations (vertical bar) for display. Differences between groups receiving M-LLO.FP or unconjugated LLO.FP were significant for all classes of antibody.
[0065] FIG. 3 shows the levels of antigen specific IgA in the serum and distant mucosal sites over a 41 day period: (CBAxBALB/c) F1 mice were immunised on day 0, 10 and 17 with 12 μg of M-LLOFP, with 1 μg of CT mixed with 12 μg of LLOFP or with 12 μg of LLOFP alone. Serum (a), vaginal washings (b), and mouth washings (c) were collected from 5 individual mice on days 7, 20, 27 and 41. Antigen specific IgA titres were determined by ELISA and the progress in individual mice shown.
[0066] FIG. 4 shows the antigen specific IgA at distant mucosal sites over a 112 day period: (CBAxBALB/c) F1 mice were immunised on day 0, 28 and 56 with 12 μg of M-LLOFP, with 1 μg of CT mixed with 12 μg of LLOFP or with 12 μg of LLOFP alone. Serum (a) and, vaginal washings (b) were collected from 4 individual mice on day 31, 74, and 112. Antigen specific IgA titres were determined by ELISA and the progress in individual mice shown.
[0067] FIG. 5 shows the antigen specific IgA in the tears and in the lung washings. (CBAxBALB/c) F1 mice were immunised on day 0, 10 and 17 with 12 μg of M-LLO.FP or with 12 μg of LLO.FP alone. Mice were anaesthetised on day 24 of the experiment and tears (1 μl) collected from 5 mice per group (a). Mice were euthanased on day 35 of the experiment and lung washings (0.5 ml) collected (b). Antigen specific IgA titres were determined by ELISA and individual titres are shown as dot plots. In addition, titres were converted to geometric means (heavy bar) and standard deviations (vertical bar) for display. Differences between groups receiving M-LLO.FP or unconjugated LLO.FP were significant (p<0.01) in tear samples and (p<0.05) for lung washings.
[0068] FIG. 6 shows the effects of the M-LLOFP conjugate when in the oxidised form: (CBAxBALB/c) mice were immunised intranasally with 12 μg of M-LLOFP in the oxidised or reduced form on day 0, 10 and 17. Serum from 5 individual mice was collected on day 24 and antigen specific IgA (a), IgG1 (b) and IgG2a (c) was detected by ELISA. Individual titres are shown as dot plots, with corresponding symbols for different antibody classes from the same mouse. In addition, titres were converted to log 10 and geometric means (heavy bar) and standard deviations (vertical bar) were derived and converted back to arithmetic numbers for display. Differences between groups receiving oxidised or reduced M-LLO.FP were significant (p<0.02) for all classes of antibody (Student's t test).
[0069] FIG. 7( a ) shows the effects of oxidised mannan as adjuvant for mycobacterial 19 kDa FP: Groups of 4 C57/B.10 mice were immunised intranasally with 12 μg of M-19FP or 12 μg of 19 kDaFP on day 0, 10 and 17. Serum was collected on day 24 and antigen specific IgA determined by ELISA. Individual titres are shown as dot plots. In addition, titres were converted to log 10 and geometric means (heavy bar) and standard deviations (vertical bar) were derived and converted back to arithmetic numbers for display. Differences between groups receiving M-19FP and 19FP alone were significant by Student's t test (p<0.02).
[0070] FIG. 7( b ) shows ELISA readings for IgA titres for mice immunised with hsp-65-mannan conjugate.
[0071] FIG. 8 . Comparison of intranasal and intraperitoneal immunisation with M-LLO.FP. (CBAxBALB/c) F1 mice (4 per group) were immunised with 12 μg of M-LLO.FP i.n. or i.p. or unconjugated control on day 0, 10 and 17 and mice sacrificed on day 24. (a) Proliferative response: Spleen cells from all groups were cultured in the presence of antigen (45 μg/ml LLO (215-226) (▪) or without stimulus (□). Data represent the means and standard deviations of triplicate cultures. *p<0.002 compared with M-LLO.FP i.p. (b) IL-2 production: Spleen cells from all groups were cultured in the presence of antigen (45 μg/ml LLO (215-226) (▪) or LLO.FP ( )) or without stimulus (□). Data represent the means and standard deviations of triplicate cultures. *p<0.01 **p<0.002 compared M-LLO.FP i.p. (c) IFN-γ producing cells: Spleen cells from all groups were cultured in the presence of antigen (45 μg/ml of LLO.FP (▪)) or without stimulus (□). Data represent the means and standard deviations of triplicate cultures. *p<0.05 compared with M-LLO.FP i.p.
[0072] FIG. 9 . IFN-γ and IL-4 production following i.n. immunisation with oxidised or reduced M-LLO.FP. (CBAxBALB/c) F1 mice (5 per group) were immunised i.n. with 12 μg of M-LLO.FP (oxidised) or with M-LLO.FP (reduced) on day 0, 10 and 17 or infected i.v. with 1×10 3 Listeria on day 17. Mice were sacrificed on day 24. Spleen cells from all groups were cultured in the presence of antigen (45 μg/ml of LLO.FP (▪)) or without stimulus (□) and the frequency of (a) IFN-γ and (b) IL-4 producing cells determined. Data represent the means and standard deviations of triplicate cultures. *p<0.02, **p<0.05 compared with the reduced group for IFN-γ and IL-4 respectively. Note different scales.
[0073] FIG. 10 . IFN-γ production following i.n. immunisation with M-19.FP. C57BL/10 mice (4 per group) were immunised i.n. with 12 μg of M-19.FP or unconjugated control on day 0, 10 and 17 or infected i.n. with M. avium 6 weeks prior to immunisation. Mice were sacrificed on day 24 and spleen cells from all groups cultured in the presence of antigen (▪) (19 kDa.FP 23 μg/ml), 10 7 live M. avium ( ) or without stimulus (□). Data represent the means and standard deviations of triplicate wells. *p<0.05 compared with the 19.kDa.FP group.
[0074] FIG. 11 : Antibody titres in serum following immunisation with VP5 246-274 FP with and without mannan adjuvant: Mice were immunised intranasally with 6 μg VP5 246-274 -mannan of VP5 246-274 alone on days 0, 10 and 17, and bled from the tail vein on days 24 and 35. Titres are expressed as log 10 geometric means plus or minus standard deviation for groups of 5 mice. Differences p<0.05 are considered significant. **p<0.02, *p<0.05.
[0075] FIG. 12 : IgA titres on mucosal surfaces following immunisation with VP5 246-274 FP with and without mannan adjuvant: Mice were immunised intranasally with 6 μg VP5 246-274 -mannan of VP5 246-274 alone on days 0, 10 and 17. Titres are expressed as log 10 geometric means plus or minus standard deviation for groups of 5 mice.
[0076] (A). On day 24 tears were collected as described and IgA antibody assayed by ELISA. Note limit of detection was 1/100 and no antibody was detected in mice receiving antigen alone.
[0077] (B). On day 34 stools were collected, homogenised in 10× volume of PBS and the extracted IgA antibody assayed by ELISA. Note limit of detection was 1/10 and no antibody was detected in mice receiving antigen alone.
[0078] (C) On day 35 the mice were sacrificed and lung washings collected. Significant difference in titres, p<0.02.
[0079] FIG. 13 . Protection against Porphyrornonas gingivalis lesions: Groups of 5 C57B1/10 mice were immunised with Cpx-mannan given intranasally ( FIG. 13( a )) or Cpx in incomplete Freund's adjuvant (IFA) subcutaneously ( FIG. 13( b )). Control mice received the respective adjuvants alone. Mice given Cpx-mannan intranasally showed no lesions—complete protection (p<0.001), while those given Cpx in IFA showed incomplete protection (p<0.05).
[0080] FIG. 14 . Serum antibody titres: Groups of 5 C57B1/10 mice were immunised with Cpx-mannan given intranasally or Cpx in incomplete Freund's adjuvants (IFA) subcutaneously. Control mice received the respective adjuvants alone. The mice were bled from the retro-orbital plexus after 2 or three doses and serum antibody assayed by ELISA. Titres on pooled sera are shown.
[0081] FIG. 15 : Antibody titres in serum following immunisation with E7.FP coupled to mannan under oxidising or reducing conditions or without mannan adjuvant (E7 alone): Mice were immunised intranasally with 12 μg antigen (with or without mannan) on days 0, 10 and 17, and bled from the tail vein on days 24. Titres are expressed as log 10 geometric means plus or minus standard deviation for groups of 5 mice. Titres of all classes of antibody in groups immunised E7.FP plus either oxidised or reduced mannan were significantly different from the group receiving E7.FP, alone p<0.01.
EXAMPLE 1
Materials and General Methods
[0082] Mice: Female 6-8 week old (CBAxBALB/c)F1 and C57Bl/10 mice were bred and maintained under conventional but infection-free conditions in the animal house of the Department of Microbiology and Immunology, University of Melbourne.
[0083] Production of antigens: A p. bluescript plasmid containing the gene for Listeriolysin O (LLO) from Listeria monocytogenes (without its leader sequence) was obtained from Richard Strugnell (University of Melbourne, Australia) and subcloned into the Escherichia coli expression vector pGEX-2T [16] in the correct reading frame and orientation. The expression of an 84 kDa LLO glutathione-s-transferase (GST) fusion protein (LLO.FP) was induced with 0.1 mM IPTG (Sigma Chemical Co., MO, USA) at 37° C. for 5 hours. Bacteria were collected by centrifugation (1,500×g) for 5 minutes, washed and lysed by sonication. The pellet was collected after centrifugation and solubilised in 8M urea (Eastman Kodak Co., Rochester, N.Y., USA) overnight at 4° C. After further centrifugation (26,000×g) for 15 minutes the supernatant was dialysed in 0.01M Tris (Sigma Chemical Co., MO, USA) pH 8.0/1M urea and the BIOCAD perfusion chromatography system (Perceptive Biosystems, Framingham, Mass., USA) used to purify the protein by anion exchange.
[0084] The 19 kDa lipoprotein from Mycobacterium tuberculosis was produced using a recombinant 19 kDa-plasmid construct was obtained from Professor Douglas Young (Imperial College School of Medicine, London, U.K) and the expression of a 19 kDa HIS tag fusion protein (19FP) induced with 0.1 mM IPTG at 37° C. for 5 hours. Bacteria were collected by centrifugation (1,500×g), washed and lysed by sonication. The supernatant was collected after further centrifugation (26,000×g) for 15 minutes and dialysed in 0.01M Tris pH 8.0/300 mM NaCl/20 mM imidazole and purified under native conditions on a Nickel chelate column (Qiagen, Hilden, Germany) using the BIOCAD perfusion chromatography system.
[0085] Rotavirus VP5 antigen was produced recombinantly using the gene for the fragment of VP5 from amino acid 248-475 (VP5 246-274 ) [17]. This gene fragment was cloned into the pGEX plasmid to create a fusion protein with glutathione S transferase. The recombinant E. coli was grown overnight at 37° C. in LB-ampicillin medium and subcultured at 1:50 dilution into fresh LB-ampicillin medium. After incubation of the bacteria at 20° C. until OD 600 =1.4-1.6 (about 12-16 hours), expression of the fusion protein was induced with 0.01 mM IPTG for 6-8 hours at 20° C. Bacteria were harvested and washed before sonication in PBS for 15 seconds each. Centrifugation followed by passage through a 0.45 μm filter was used to collect soluble protein. The GST fusion protein was purified using Glutathione Beads, according to the manufacturers' instructions (Sigma, Mo., USA). The eluted GST-VP5 was passed through the 0.45 μm filter to remove traces of beads and the protein dialysed against pH9 bicarbonate buffer.
[0086] The antigen, hsp65 of Mycobacterium avium was produced recombinantly according to standard methods. The cloning and expression of hsp65 of Mycobacterium avium has been described by V. Nagabhushanam, J. Praszkier and C. Cheers, Immunology and Cell Biology (2001) in press. Briefly the sequences of hsp65 genes from various mycobacterial species were obtained from GenBank, aligned and used to design primers. The open reading frame of the hsp65 gene of M. avium was amplified by PCR. The purified PCR product was inserted into M13tg131B. The insert was re-cloned into M13tg130B, which facilitated sequencing of the complementary strand of the insert. The fragment containing the coding sequence the hsp65 was moved from the M13tg130B derivative into p2GEX-2T, so that the hsp65 reading frame was fused in-frame to the 3′ end of one of the two copies of the glutathione-S-transferase (GST) of Schistosoma japonicum. E. coli strain BL21, transformed with the recombinant plasmid p2GEX-hsp65. Expression of the GST fusion was induced by the addition of 0.1 mM Isopropylthiogalactoside (IPTG) (Sigma). Bacteria were harvested, washed and lysed. The cell lysate was cleared by centrifugation and the separated cell pellet and supernatant analysed on a 12% SDS-PAGE. The supernatant, which contained the majority of the fusion protein (GST-Hsp65) was filtered and the GST fusion protein purified by binding to glutathione agarose beads according to manufacturers' instructions (Sigma). To cleave Hsp65 from GST, the beads were incubated overnight at room temperature with thrombin (Pharmacia) (10 units per milligram of protein) in 10 ml of PBS, then pelleted, the supernatant collected and the protein content estimated spectrophotometrically.
[0087] The E7 antigen of Human Papilloma Virus (HPV) was produced by recombinant means. The DNA sequence for the E7 antigen from HPV was cloned into the pGEX-2T vectors. Protein expression was induced by IPTG, and purified using glutathione-sepharose column chromatography. Elution of the bound protein was with a solution of 5 mM glutathione in Tris 0.05M, pH 8.0.
[0088] The antigen, Cpx, of Porphyromonas gingivalis was prepared according to O'Brien-Simpson et al. [18].
[0089] Preparation of oxidised or reduced mannan-antigen conjugates: Mannan (Sigma Chemical Co., St Louis, Mo., USA) was coupled to the antigens under oxidising conditions. Mannan at 14 mg/ml in 0.1M phosphate buffer pH 6.0 was oxidised with 0.01 M sodium periodate for 60 min at 4° C. Ten microlitres of ethandiol (Sigma Chemical Co., St Louis, Mo., USA) was added to quench the reaction and the mixture incubated for 30 min at 4° C. This mixture was then passed through a PD-10 column (Pharmacia Biotech, Uppsala, Sweden) equilibrated with bicarbonate buffer pH 9.0. The oxidised mannan, eluted in the 2 ml void volume, was mixed with 700 μg of the antigen, incubated overnight at room temperature and used without any further purification. Conjugation was confirmed when the conjugates were separated using 12.5% sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and a heterogeneous smear (compared with the single band of uncoupled protein) was observed using Comassie Blue stain. For comparison in some experiments, the oxidised conjugates were reduced with sodium borohydride (NaBH 4 ) (Aldrich, Castle Hill, NSW, Australia) 1 mg/ml overnight at room temperature and used without further purification.
[0090] Immunisation with Mannan-antigen conjugates: Mice were lightly anaesthetised with penthrane and 50 μl of mannan-antigen conjugate (12 μg antigen/mouse in bicarbonate buffer pH9.0, unless otherwise specified), placed onto the nares to be inhaled by the mouse. The same amount of non-conjugated antigen was similarly applied. Unless stated otherwise, this procedure was performed on days 0, 10 and 17 of the experiments. In some experiments mice were given 12 μg of mannan-LLO.FP (M-LLO.FP) conjugate intraperitoneally in 0.2 ml bicarbonate buffer pH 9.0 on days 0, 10 and 17. Cholera toxin (Sigma Chemical Co., St Louis, Mo., USA) was also used for comparative purposes as an adjuvant to act as a positive control in some experiments. One microgram of CT was mixed with 12 μg of LLO.FP and administered intranasally (i.n) in a 50 μl volume on days 0, 10 and 17.
[0091] Collection of samples: Serum samples were collected after mice were bled by cardiac puncture following euthanasia at the end of each experiment. For time-course experiments mice were placed on a heat box, a small incision made in a lateral vein and 200 μl of blood collected with a micropippeter. The serum was subsequently separated by centrifugation. Mouth and vaginal washings were collected from anaesthetised mice, by washing with 50 or 100 μl of phosphate buffered saline (PBS) respectively, using a micropippetor. For the collection of faecal samples, mice were placed in cages without sawdust and 2-5 fresh stools were collected per mouse. One ml of PBS/SBTI (PBS containing 0.1 mg/ml soybean trypsin inhibitor (Sigma Chemical Co., St Louis, Mo., USA)) was added for every 0.1 gm of faeces. The samples were vortexed for 15 minutes and then microcentrifuged at 15,000×g for 15 minutes at 4° C. Phenyl sulphonyl fluoride (PMSF) (Sigma Chemical Co., St Louis, Mo., USA) at a final concentration of 1 mM was then added to the supernatants.
[0092] Tears were collected by lightly anaethetising the mice with penthrane and a sliver of filter paper was briefly touched on the upper and lower conjunctiva, collecting about 1 μl of tears. The paper was then immersed in 100 μl PBS-Tween to extract antibody [19]. Lung washings were obtained after mice were euthanased with CO 2 . Lungs were washed in situ with 0.5 ml PBS through an opening in the trachea. All samples were stored at −20° C. prior to assay.
[0093] Detection of antibody in the serum and mucosal sites by ELISA: Microtitre plates (Nunc Roskilde, Denmark) were coated overnight at 4° C. with 5 μg/ml antigen in carbonate buffer pH 9.1. The wells were then blocked with 2% foetal calf serum (FCS) (Trace Biosciences, Castle Hill, NSW, Australia) in PBS for 1 hour at 37° C. The plates were washed 3 times with 0.08% Tween 20 (BDH Laboratory Supplies, Poole, England) PBS and appropriately diluted samples in 50 μl added and incubated for 2 hours at room temperature. After two more washes, antigen-specific IgA was detected by the addition of an anti-mouse IgA affinity purified horse radish peroxidase (HRP) conjugate (Southern Biotechnology Associates Inc. Birmingham, USA) diluted 1/1000 in 0.1% bovine serum albumin (BSA) (CSL, Melbourne, Australia) for 1 hour at room temperature. Antigen specific IgG1 or IgG2a was detected with the addition of a biotinylated anti-mouse IgG1 or IgG2a conjugate (Caltag Laboratories, Burlinggame, Ca, USA) diluted 1/1000 in 0.1% BSA. The plates were washed twice more and a streptavidin peroxidase conjugate (Boehringer Mannheim, Mannheim, Germany) added at a 1/1000 dilution in 0.1% BSA. Following a further two washes, the antibody titres of all the subclasses tested were determined when the substrates containing either 0.4 g/l 3,3′,5,5′-tetramethylbenzidine (TMB) (Kirkgaard and Perry Laboratories, Gaithersburg, Md., USA) and 0.02% H 2 O 2 or 2,2′-azino-bis(3-ethylbenthiazoline-6-sulphonic acid) (ABTS) (Sigma Chemical Co., St Louis, Mo., USA) and 0.03% H 2 O 2 were added (50 μl/well). Plates were left 10 minutes for colour to develop and the reaction stopped with 2M H 2 SO 4 for the TMB substrate or 0.2M citric acid for ABTS. OD at 450 nm (TMB) or 405 nm (ABTS) was read in an ELISA reader (Labsystems, Helsinki, Finland). Antibody titres were presented as the highest dilution which yielded an optical density at 450 nm or 405 nm >0.1 OD units higher than normal serum at 1/100 dilution. For calculation of means, the titre was converted to log in and a geometric mean was derived.
[0094] Spleen cell proliferation and cytokine production: Mice were euthanased with CO 2 and spleen cells prepared by passage through an 80 gauge wire mesh sieve. Red blood cells were lysed using Tris-NH 4 Cl buffer [20]. After thorough washing, suspensions of spleen cells were cultured in flat-bottomed 96 well plates at a concentration of 2×10 6 /ml in 200 μl volumes with and without the MHC class II restricted epitope of LLO (215-226) (45 μg/ml) for 3 days at 37° C., 5% CO 2 . For the last 5 hrs the cells were pulsed with 0.25 μCi [ 3 H]-TdR (Amersham, Buckinghamshire, U.K) before being harvested onto glass fibre filters (Packard, Meridan, Conn., USA) using the Micro 96 harvester (Skatron Instruments, Wokingham, UK) and β emissions counted using a Packard Matrix 9600 (Packard). For IL-2 bioassay, supernatants from similarly-cultured cells were collected after 24 hour culture and IL-2 was assayed by its ability to cause the proliferation of CTLL cells [21].
[0095] Elispot: Spleen cells were assayed for the frequency of IFN-γ and IL-4 producing cells. Maxisorp 96 well plates (Nunc) were coated overnight at 4° C. with 500 of 10 μg/ml anti-IFN-γ monoclonal antibody HB170 [22] or 100 μl of anti-IL-4 monoclonal antibody 11B11 [23] in carbonate buffer pH 9.6. The plates were washed with PBS and blocked with culture medium at 37° C. for 1 hr. Cells (2×10 5 , 1×10 5 , 5×10 4 , 2.5×10 4 per well) were added to the wells in conjunction with the appropriate antigen (45 μg/ml) and incubated for 72 hrs at 37° C. in 5% CO 2 . The cells were removed and cytokines detected with the addition of a biotinylated secondary rat anti-mouse anti-IFN-γ antibody XMG 1.2 [24] or rat anti-mouse anti-IL-4 antibody BVD6 [25] at a 1/1000 dilution. Following the addition of streptavidin alkaline phosphatase (Boehringer Mannheim) the spots were developed using 5-bromo-4-chloro-3-indyl phosphate/nitrobluetetrazolium (BCIP/NBT) (Sigma) tablets. The spots were counted using a dissecting microscope and the frequency determined by averaging the number of spots for triplicate wells.
[0096] Statistics: The statistical significance of data was determined by the two-sample ranks test (Wilcoxon-White) or by Student's t test based on the log 10 titre. Differences with p<0.05 were considered significant.
EXAMPLE 2
Effects of Immunisation
[0097] A Listeriolysin-mannan (M-LLO) conjugate was prepared as described in Example 1.
[0098] LLO specific antibodies in serum M-LLO.FP following intranasal immunisation: To determine whether the intranasal route of immunisation was superior to intraperitoneal in inducing substantial IgA antibody responses, (CBAxBALB/c)F1 mice were immunised i.n or i.p. on days 0, 10 and 17 with 12 μg M-LLO.FP. Serum was obtained from three mice 7 days after the final immunisation and antibody levels measured by ELISA ( FIG. 1 ). Mice immunised i.n with M-LLO.FP, produced antigen-specific IgA to a geometric mean titre of 1/900 (log 2.96±0.21) ( FIG. 1 a ), whereas IgA antibody was not detectable after the standard i.p. immunisation. It should be noted that i.p. immunisation could lead to antibody production, as IgG1 titres of 1/640 were detected ( FIG. 1 b ). However, even with this isotype i.n immunisation was superior, inducing titres in excess of 1/1280.
[0099] To further investigate the different antibody classes induced by i.n immunisation, (CBAxBALB/c) F1 mice were immunised i.n with 12 μg of M-LLO.FP conjugate on days 0, 10 and 17 and bled on day 24. The serum antibody levels from individual mice were measured by ELISA ( FIG. 2 ). IgA serum antibody responses in M-LLO.FP immunised mice (1/5184) were higher than those obtained from mice immunised i.n with 12 μg of non-conjugated LLO.FP (1/25) ( FIG. 2 a ). A significant difference (p<0.01) in the IgG1 response ( FIG. 2 b ), was observed with titres more than 80× higher for M-LLO.FP compared with non-conjugated LLO.FP. A significant difference (p<0.01) was observed between conjugated and non-conjugated LLO.FP with IgG2a titres of 1/32512 and 1/383 respectively ( FIG. 2 c ). Infection with Listeria monocytogenes , an organism known for its induction of cell mediated immunity, resulted in minimal antibody responses. Overall, the greatest percentage increases were noted for the IgA and IgG2a subclasses of antibody. The experiment was repeated with conjugates prepared on different occasions with three different batches of mannan, and proved to be a very reproducible observation.
[0100] Comparison between oxidised mannan and CT as mucosal adjuvants: In previous studies where CT has been used as a mucosal adjuvant in mice, the immunisation regimes adopted have varied [26, 27]. Therefore, to compare the adjuvanticity of mannan and CT the initial experiment was performed using the schedule previously found optimal for mannan [28] of administering antigen and adjuvant on days 0, 10 and 17. (CBAxBALB/c) F1 mice were given either 12 μg of M-LLO.FP or CT+LLO.FP i.n. Serum, vaginal washings, mouth washings and faecal samples were collected at the times shown on FIG. 3 for titration of IgA. IgA titres in negative control groups, including mannan alone, CT alone and normal serum, were not more than the limit of detection and are not shown.
[0101] Oxidised mannan was a consistently better mucosal adjuvant than CT when administered with LLO.FP. Immunisation with M-LLO.FP induced a peak geometric mean IgA titre of 1/667 in serum with some titres in excess of 1/1280. This compared with 1/165 for CT+LLO.FP ( FIG. 3 a ). LLO.FP alone induced a mean titre of only 1/69.
[0102] The superior efficacy of M-LLO.FP was also observed at distant mucosal sites. IgA titres in vaginal washings ( FIG. 3 b ) were more variable than in serum, but individual mice reached titres >1/320 (geometric mean=1/195) after M-LLO.FP, compared with a mean of 1/55 for CT+LLO.FP. LLO.FP alone induced a mean titre of 1/37. IgA titres in the saliva ( FIG. 3 c ) of M-LLO.FP immunised mice were only detectable on day 41 of the experiment with a mean of 1/10 and a high of 1/28. Titres, although low, were higher than those observed for LLO.FP or CT+LLO.FP. In both instances, CT was quite a poor adjuvant.
[0103] In a second series of experiments ( FIG. 4 ), the immunisation schedule was extended to 0, 28 and 56 days, with doses as before, to test whether a longer time between prime and boost would favour either adjuvant. Again the response to M-LLO.FP produced higher titres than CT+LLO.FP. The peak geometric mean titres following M-LLO.FP were 1/1040 in serum and 1/256 in vaginal washings. This compared with 1/44 and 1/22 respectively following CT+LLO.FP. Although differences were often not statistically significant because of the variability of individual mice, oxidised mannan was consistently the better adjuvant under two different immunisation regimes.
[0104] IgA titres were examined over a considerable timecourse in these experiments. In general, they did not reach substantial levels until after three injections, whether of M-LLO.FP or CT+LLO.FP. IgA persisted at peak titre in the serum for more than three weeks after the last immunisation, particularly of M-LLO.FP ( FIGS. 3 a , 4 a ). IgA, production in the vagina ( FIGS. 3 b , 4 b ) also required three immunisations and these titres were more variable than in serum, and generally less sustained.
[0105] To extend the investigation of mucosal IgA to other sites, (CBAxBALB/c) F1 mice were immunised i.n. with M-LLO.FP as before and tears and lung washings collected on days 24 and 35 respectively., Mice immunised with M-LLO.FP conjugate produced significantly higher titres of IgA (p<0.01) in tears when compared with the unconjugated controls (geometric means titres: M-LLO.FP 1/121 compared with 1/25 for LLO.FP alone) ( FIG. 5 a ). The same trend was observed in the lungs at day 35 ( FIG. 5 b ). Significantly higher titres of IgA were detected in mice immunised with M-LLO.FP (1/975) compared with LLO.FP alone (1/38) (p<0.05).
EXAMPLE 3
Influence of Conjugation of Mannan to Antigen on IgA Induction
[0106] To investigate whether there was a need for the mannan to be conjugated to LLO.FP or whether the adjuvant effect could be achieved when mannan was simply mixed with antigen, mice were immunised with the M-LLO.FP conjugate or with a mannan+LLO.FP mixture (mannan and 12 μg of LLO.FP mixed together). (CBAxBALB/c)F1 mice were immunised i.n on days 0, 10 and 17. Serum and vaginal washings were taken from individual mice on day 24 of the experiment. IgA titres were subsequently determined by ELISA (Table 1). The results showed that a conjugate provides a better adjuvant effect. The geometric mean antibody titre in the serum for conjugated LLO.FP was >1/1000. This was significantly higher than the mannan+LLO.FP mixture which produced an average titre of 1/34. Notwithstanding this some antibody is obtained from the mannan antigen admixture. A similar pattern was seen in the antibody response at a distant mucosal site, namely the vagina, with titres of 1/195 for the conjugate and 1/45 for the mixture. All negative controls produced undetectable levels of IgA with small titres of antibody observed in vaginal washings for the LLO.FP alone group (1/14).
[0107] Earlier experiments with mannan-conjugated proteins injected i.p. showed that conjugates produced under reduced conditions were better at inducing antibody than were oxidised conjugates [13]. Therefore, (CBAxBALB/c) F1 mice were immunised i.n with 12 μg of M-LLO.FP conjugate (oxidised form) or 12 μg of M-LLO.FP conjugate (reduced form). The results indicated that the oxidised form of the M-LLO.FP conjugate given i.n induced higher titres of IgA, IgG1 and IgG2a in the serum ( FIG. 6 a, b and c ) compared with the reduced form. All four mice immunised with M-LLO.FP (oxidised form) had higher titres than the corresponding four mice given the reduced form of M-LLO.FP, with the exception of one high responder mouse in the group given reduced mannan. Significant differences (p<0.02) applied to all the subclasses assayed (geometric mean titres: IgA=1/1380 for oxidised, 1/275 for reduced; IgG1=1/3388 for oxidised, 1/813 for reduced; IgG2a=1/1660 for oxidised, 1/173 for reduced).
EXAMPLE 4
Mannan as Adjuvant for Other Antigens
[0108] To demonstrate that the use of mannan as a mucosal adjuvant was applicable to other antigens mannan was conjugated to the 19 kDa lipoprotein of Mycobacterium tuberculosis and to Mycobacterium avium antigen hsp65 as set forth in Example 1. C57Bl/10 mice were immunised i.n. with 12 μg of M-19FP conjugate on days 0, 10 and 17. On day 24 of the experiment the mice were euthanased and bled by cardiac puncture. Mice were similarly immunised with mannan hsp65. Serum was separated and IgA titres determined by ELISA ( FIG. 7 a ). The four mice immunised with M-19FP produced significantly higher titres of IgA (geometric mean 1/1530) when compared with mice given 12 μg of 19 kDaFP (titres of IgA <1/100). The results for mice immunised with mannan-hsp65 are shown in FIG. 7( b ). IgA titres for the immunised mice were well above that of the normal mice.
[0109] The examples above present mannan as a novel mucosal adjuvant which, when administered intranasally, induced high mucosal and serum titres of IgA, IgG1 and IgG2a specific for recombinant protein antigens with which it was administered. Oxidised mannan was previously used conjugated to the breast cancer antigen MUC1 and injected i.p. into mice where it induced CTL and a Th1 cytokines, protecting against tumours expressing MUC1 [12, 13]. In that context it induced a poor antibody response, dominated by IgG2a. It was the change to intranasal administration in the current experiments which resulted production of IgA and other classes of antibody in serum and mucosal secretions.
[0110] The induction of IgA responses on mucosal surfaces is a highly desirable outcome in immunisation against a wide spectrum of diseases. Amongst other examples, mucosal antibodies and particularly IgA, have been shown to protect against influenza in the lung [29], against Helicobacter pylori in the stomach [30], against Haemophilis influenzae in the ear [31] and against Chlamidia trachomatis in the genital tract [32]. Induction of IgA and other mucosal antibodies following intramuscular or subcutaneous immunisation with conventional vaccines is poor [33, 33a]. Therefore oxidised mannan may be a valuable adjuvant if coupled to protective antigens from a wide variety of infectious agents.
[0111] Cholera toxin has become the most extensively studied mucosal adjuvant in experimental models, although its relative toxicity has so far precluded it from approval as a human adjuvant [34]. In the present experiments, immunisation with mannan-conjugated LLO intranasally induced superior IgA and IgG2a responses in the mucosa and serum compared with CT plus LLO or LLO alone. The difference in the IgG1 response was less marked, but still higher for the mannan adjuvant. Titres of antibody following immunisation with mannan conjugates were not only higher than with CT, they were more sustained. Mannan has the further advantage over CT in being non-toxic and already approved for human use and is currently involved in human trails for cancer therapy [14]. As with the present observations on mannan, a mixture of the B subunit of CT (CTB) with antigen resulted in higher titres of IgA in the serum and mucosa when given to mice intranasally rather than intraperitoneally [33]. It is widely believed that this influence of the route of exposure is a function of the mucosal antigen presenting cells.
[0112] Two interesting observations were made when analysing the form of the antigen/adjuvant in the present experiments. The first showed that oxidised mannan conjugated to the antigen (LLO.FP or 19 kDaFP) facilitates the adjuvant effect. This confirms the observations with the MUC 1 studies where conjugation of oxidised mannan to the MUC 1 antigen induced better immune responses [13]. The second observation contrasts with the MUC 1 studies because the oxidised form of the M-LLO.FP induced maximum antibody production. Immunisation with the oxidised form of mannan-MUC 1 resulted in low antibody levels [13].
[0113] How, then, does mannan act as an adjuvant? It has been shown that antigens bearing mannose residues are bound to the mannose receptors on antigen presenting cells (APC), facilitating uptake into the MHC Class II pathway for efficient antigen presentation [35, 36, 37]. Oxidised mannan-MUC1 induced both Class I restricted CTL and a Th1 response [12]. It has been suggested that oxidised mannan-MUC1, by virtue of the aldehyde residues created by the oxidation process, escapes the phagocytic pathway and is transported into the MHC Class I pathway inducing CTL [15]. This pathway would not be open to reduced complexes, where aldehyde residues are reduced to alcohols by the action of boral hydrate. The exact mechanism by which aldehyde acts is unknown. Curiously, the inventors did not detect the induction of Class I-restricted CTL in experiments with M-LLO.FP injected i.p. Furthermore, the response to the inventor's antigens given intranasally was not classically either Th1 or Th2, since IgG1 and IgA (generally considered Th2 responses) and IgG2a (Th1) were all elevated. This was confirmed by cytokine assays where both IFN-γ and IL-4 were elevated. This aspect is further explored in Example 5.
[0114] The mechanism by which M-LLO.FP and M-19FP induce such excellent antibody responses after i.n immunisation is unknown. Others have shown preferential induction of Th2 responses following intranasal instillation of leishmania antigens, even in strains of mouse which are genetically constrained to produce a typical Th1 response to these organisms injected parenterally [38]. Without wishing to be bound by theory it may be that alveolar macrophages or dendritic cells, which have been shown to present antigens efficiently in other systems [39], are playing a significant role in the induction of these IgA responses.
[0115] Induction of mucosal immunity begins with the uptake of antigen by membranous (M) cells (specialised epithelial cells) on the mucosal surface. These cells either process and present antigen to underlying T-Cells or B-cells themselves or transport antigen to parenchymal macrophages, dendritic cells and B-cells. Once interaction of the antigen presenting cell (APC) with T and B lymphocytes has occurred, an immune response or mucosal tolerance may result. Immune responses generally involve antibody production, with IgA the predominant antibody isotype. Antigen sensitised immune cells are then circulated to other systemic and mucosal sites for expansion of effector mechanisms [40]. The fact that there is a preferential circulation of T cells activated at mucosal sites to return to the same or other mucosal sites accounts for the induction of IgA at remote mucosal surfaces.
EXAMPLE 5
Oxidised Mannan-Listeriolysin O Conjugates Induce Th1/Th2 Cytokine Responses after Intranasal Immunisation
[0116] Clearance of infectious organisms does not always require polarised Th1 or Th2 responses. It may in fact be advantageous for both a Th1 and Th2 response to be elicited for effective protection against an invading pathogen. It was the aim of this Example to investigate oxidised mannan as a possible Th1/Th2 adjuvant.
5.1 Materials and Methods
[0117] Mice, production of antigens, conjugates and immunisation were the same as Example 1. Spleen cell proliferation, cytokine production and Elispot assays were as described in Example 1.
5.2 Results
[0118] a. Comparison of Intranasal and Intraperitoneal Immunisation
[0119] Having established that the intranasal route of administration produced better antibody responses than those measured after intraperitoneal immunisation as described in Example 2, a direct comparison between the two routes of immunisation was undertaken to determine if a similar pattern could be established for cellular responses. (CBAxBALB/c) F1 mice were immunised i.n. or i.p. on days 0, 10 and 17 with 12 μg of M-LLO.FP. On day 24 the mice were sacrificed and spleens removed. Spleen cell preparations were used to establish proliferation, IL-2 and IFN-γ ELISPOT assays. Spleen cells were cultured in the presence of the MHC class II restricted epitope of LLO (215-226) and incorporation of [ 3 H]-TdR measured to determine the proliferative response ( FIG. 8 a ). Mice immunised with M-LLO.FP intranasally produced counts significantly higher than the group of mice which had the M-LLO.FP administered by the intraperitoneal route (3972±502 vs 983±145, p<0.002). The latter approximated background levels. LLO.FP without adjuvant by either route induced background levels of proliferation only.
[0120] The ability of spleen cells to produce IL-2 is shown in FIG. 8 b . Spleen cells were cultured in the presence of LLO (215-226) or LLO.FP (45 μg/ml) and supernatants harvested at 24 hours. The ability of the supernatants to maintain the IL-2 dependent CTL cell line was determined by the incorporation of [ 3 H]-TdR. Mice immunised with M-LLO.FP intranasally produced counts of 1219±268 (LLO (215-226) ) and 4523±689 (LLO.FP). These values were significantly higher (p<0.01, p<0.002) than the group of mice which received the M-LLO.FP administered by the intraperitoneal route with geometric means of 182±73 (LLO (215-226) ) and 417±40 (LLO.FP), which approximated background levels. LLO.FP without adjuvant by either route induced background levels of IL-2.
[0121] Importantly this pattern was also observed with the IFN-γ ELISPOT ( FIG. 8 c ). Spleen cells were cultured in the presence of LLO.FP and the frequency of IFN-γ-producing cells determined by ELISPOT. Mice immunised with M-LLO.FP intranasally produced a high frequency of IFN-γ-producing cells/10 6 spleen cells (58±20), significantly higher (p<0.05) than the group of mice which had the M-LLO.FP administered by the intraperitoneal route (10±8) which approximated background levels. Mice given LLO.FP by either route without adjuvant recalled levels of IFN-γ producing cells just above background.
[0000] b. Dose Response
[0122] Intranasal immunisation with 12 μg of M-LLO.FP resulted in significant proliferative and Th1 cytokine (IL-2 and IFN-γ) responses, but Th1 responses are often favoured by lower doses of antigen [41]. Therefore, (CBAxBALB/c) F1 mice were immunised i.n. on days 0, 10 and 17 with 12 μg, 6 μg or 3 μg of M-LLO.FP and on day 24 the mice were sacrificed and spleens removed. Proliferative responses and the frequency of IFN-γ-producing cells from spleen cell preparations were measured. Proliferative responses after in vitro stimulus with the MHC class II restricted epitope of LLO indicated that intranasal immunisation with the 12 μg dose was significantly higher than the 6 μg (p<0.02) and 3 μg (p<0.01) dose of M-LLO.FP (6385±1506, 1962±649 and 1630±375 respectively). Cells from unconjugated doses of LLO.FP produced levels of proliferation slightly above background (results not shown).
[0123] A similar pattern of results was observed for the production of IFN-γ. The IFN-γ producing cells/10 6 spleen cells for the 12 μg dose was significantly higher than for the 6 μg (p<0.01) and 3 μg (p<0.01) dose of M-LLO.FP (97±20, 32±8 and 12±6 respectively). Mice given the unconjugated control antigen all produced fewer than 50 IFN-γ producing cells/10 6 spleen cells (results not shown).
[0000] c. Comparison of the Oxidised and Reduced Form of M-LLO.FP
[0124] Earlier studies with mannan-conjugated proteins injected intraperitoneally showed that conjugates produced under oxidising conditions were better at inducing Th1 responses compared to conjugates produced under reduced conditions [13] that favoured Th2 responses. To test this hypothesis (CBAxBALB/c) F1 mice were immunised i.n. with 12 μg of M-LLO.FP conjugate (oxidised form) or 12 μg of M-LLO.FP conjugate (reduced form) on days 0, 10 and 17 and mice sacrificed on day 24. A comparison of the two forms of conjugate for their ability to produce the Th1 cytokine IFN-γ or the Th2 cytokine IL-4 was performed using the ELISPOT assay. Spleen cells were cultured in the presence of LLO.FP and the frequency of IFN-γ or IL-4 producing spots determined ( FIG. 9 ). The results clearly indicated that the oxidised form of the conjugate produced significantly higher frequencies of both IFN-γ and IL-4 producing cells (107±12 and 123±12 respectively) when compared to the reduced form (32±10 and 57±38) (p<0.02, p<0.05). There was no indication that, using this antigen and route of immunisation, that the oxidised form induced Th1 and the reduced form induced Th2 cytokines. However this may be dose-dependent.
5.3. Discussion
[0125] These experiments present oxidised mannan as an adjuvant which, when administered intranasally, induced proliferative responses, IL-2 production, IFN-γ production and IL-4 production by cultured lymphocytes. Comparison of intranasal and intraperitoneal routes of immunisation revealed the superior efficacy for induction of these immune responses by the intranasal route. As most proteins administered to the mucosal surface without adjuvant fail to induce systemic or mucosal immune responses, oxidised mannan may be used as an adjuvant to induce both Th1 and Th2 immune responses. It offers the great advantage as an adjuvant of being non-toxic and already approved for human use in the context of breast-cancer therapy.
[0126] There is evidence in the literature that suggests that variations in antigen dose can polarise immune responses, inducing either DTH or antibody responses depending on antigen concentration. It is generally believed that low doses of antigen favour Th1 responses and high doses of antigen favour Th2 responses [41]. The results described in this study do not support this. Low doses of M-LLO.FP conjugate i.n. were unable to induce Th1 responses. Interestingly, the highest dose of M-LLO.FP conjugate was responsible for increases in the Th1 cytokine IFN-γ. These results contradict earlier observations where immunisation with low doses of mannan-conjugates favoured Th1 responses [28].
[0127] It appears that oxidised mannan administered intranasally can be an effective adjuvant for the induction of Th1 and Th2 responses as seen with the two model antigens used in this Example. This ability is of particular interest with infections such as C. trachomatis or H. pylori where both cell mediated and humoral responses appear necessary for control of infection. In the case of C. trachomatis , cell mediated responses alone appear to contribute to immunopathology whereas antibody responses are not sufficient to control infection [42, 4.3]. It has been suggested in the case of H. pylori that Th1 and Th2 responses are required at different stages for control of infection. The early response is dominated by Th1 and the late by Th2 [44]. Candidate vaccines such as those contemplated by the present invention with the ability to produce both Th1 and Th2 responses might therefore prove to be effective against both pathogens.
EXAMPLE 6
Immunisation with Rotavirus VP5 Antigen Conjugated Mannan
[0128] Mice and immunisation thereof were as described in Example 1. Samples of serum, tears and/or stools were collected as described in Example 1 at days 24 and 34 after immunisation. On day 35 the mice were sacrificed and lung washings were collected as shown in Example 1.
[0129] Detection of antibody in the samples was carried out as described in Example 1. The results are represented in FIGS. 11 and 12 . FIG. 11 shows that in mice immunised intranasally with 6 ug VP5 246-274 -mannan, titres of serum IgA, IgG1 and IgG2a were significantly higher than in mice immunised intranasally with the antigen alone, at 24 and 35 days after immunisation.
[0130] FIG. 12 shows the presence of IgA in tears collected 24 days after immunisation with the antigen-mannan conjugate, and in the stools collected at day 34. No antibody was detected in mice receiving antigen alone. IgA in lung washings was also significantly higher than in samples from animals injected with the antigen alone.
EXAMPLE 7
Protection Against Porphyromonas gingivalis Lesions
[0131] The antigen used was the major virulence factor of Porphyromonas gingivalis , the extracellular complex of Arg- and Lys-specific proteases and adhesions designated the RpgA-Kgp complex (formerly the PrtR-PrtK complex and abbreviated Cpx), prepared and conjugated with mannan as described in Example 1. Cpx antigen (12 μg) was administered intranasally on days 0, 10 and 17. Alternatively, the Cpx antigen was administered subcutaneously in incomplete Freunds adjuvant as previously described [18]. Mice were infected with 8×10 9 cells of Porphyromonas gingivalis subcutaneously in the abdomen on day 30 and lesion sizes measured over 14 days. Lesion sizes were statistically analysed using the Kruskal-Wallis test and the Mann-Whitney U-Wilcoxon rank sum test with a Bonferroni correction.
[0132] Groups of 5 C57B1/10 mice were immunised with Cpx-mannan given intranasally or Cpx in incomplete Freund's adjuvant (IFA) subcutaneously. Control mice received the respective adjuvants alone. Results of protection against challenge with Porphyromonas gingivalis are shown in FIG. 13 . Cpx linked to mannan afforded complete protection. IFA, the standard adjuvant used in studies of Porphyromonas gingivalis vaccination afforded only partial protection. Interestingly, the serum antibody titres, although raised in the mice immunised with Cpx-mannan, was higher in the mice immunised with Cpx in IFA. Both had significant adjuvant effects (p<0.05). This emphasises the point that, particularly where inflammatory lesions are critical to disease, antibody titre may not be an accurate predictor of protection.
EXAMPLE 8
Immunisation with HPV-E7
[0133] Mice were immunised with HPV-E7 conjugated to oxidised mannan, E7 conjugated to reduced mannan and with E7 alone, as per Example 1. The results ( FIG. 15 ) show no substantial difference between the oxidised and reduced forms although this may have been due to dose levels.
EXAMPLE 9
Immunisation with Other Antigens
[0134] Antigens used in accordance with the invention may also be produced by conventional peptide synthesis after selecting putative immunogenic peptides. The putative immunogenic peptides may be selected from published studies or may be peptides suspected of being immunogenic based on a skilled person's knowledge of the art. The putative immunogenic peptides are then coupled to a carrier protein which is, in turn, conjugated to mannan.
[0135] Alternatively, plasmids containing genes encoding selected antigens are expressed in E. coli . The proteins coupled to mannan are administered and the antibody response at the site most relevant to protection is examined. Examples of proteins that can be tested are as follows:
[0000]
PROTECTIVE
SITE OF
ORGANISM
DISEASE
ANTIGEN
ANTIBODY
Influenza virus
Flu
Haemagglutinin
Lungs
Helicobacter
Stomach ulcers,
Recombinant
Stomach
pylori
cancer
proteins, urease
Rotavirus
Gastroenteritis in
Recombinant VP4
Intestine
infants
protein and its
fragment VP5 and
other outer capsid
proteins
Chlamydia
Sexually transmitted
Major outer
Vagina, Eye
trachomatis
disease, pelvic
membrane protein
inflammatory
disease, non-
specific urethritis,
trachoma
[0136] Mannan-antigen complexes are encased in various timed-delivery capsules and delivered intranasally, orally or rectally. At intervals, serum, saliva, lung or vaginal washings will be collected, and ELISA are used to measure IgG1, IgG2a, IgE and IgA.
CONCLUSION
[0137] In this study the inventors have shown the application of the invention to a number of antigens. In addition, they have shown that antibodies to the antigens have been detected at a number of sites including serum, lungs, vagina, lachrymal glands and colon. These results are surprising for a number of reasons. Past studies have demonstrated that mice immunised by standard methods with oxidised mannan-human MUC1 conjugate produced cellular immunity but little humoral immunity (i.e. antibody). Whereas when the reduced form of the same conjugate was administered to mice by standard methods only a serum antibody response was found. Other studies have shown that when various antigens (MUC1, lysteriolysin) conjugated to oxidised mannan were administered to humans, mice and monkeys mostly IgG1 antibodies were found. There was no IgA response. Given this background it was extremely surprising that intranasal administration of mannan-antigen gave rise to secreted IgA.
[0138] The work done by the inventors indicates that intranasal administration of mannan and antigen may advance vaccine development for sexually transmitted diseases such as chlamydia or human immunodeficiency virus, gum disease, eye diseases, other mucosally acquired infections like influenza and rotavirus or even have veterinary application with uses in animal infections or pest control. The fact is that this is a novel, non-toxic adjuvant that induces systemic and mucosal antibody responses superior to the standard mucosal adjuvant CT.
[0139] It is to be understood that although preferred embodiments of the invention have been described in detail, various modifications, variations and adaptations may be made by those skilled in the art without departing from the central concept of the invention.
[0140] It is also to be understood that the term “comprise” or any of its grammatical equivalents has the same scope as the term “include” and its grammatical equivalents.
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[0000]
TABLE 1
Requirement for conjugation of mannan and LLOFP
for IgA production:
Log 10 IgA antibody titre
Antigen/Adjuvant a
Serum b
Vaginal washings b
M − LLO.FP (linked)
3.00 ± 0.19 c
2.29 ± 0.70 c
M + LLO.FP (mixed)
1.53 ± 0.49
1.65 ± 0.48
LLO.FP
1.15 ± 0.30
1.15 ± 0.11
Mannan
<1
1.12 ± 0.15
Normal
<1
1.08 ± 0.10
a (CBA × BALB/c) mice were immunised intranasally with M − LLOFP, LLOFP, mannan mixed with LLOFP (unconjugated) or mannan alone on day 0, 10 and 17. Serum samples and vaginal washings obtained on day 24 from 4 individual mice.
b Individual IgA titres were determined by ELISA. Antibody titres were converted to log 10 and geometric means and standard deviations were derived.
c Significantly different from mannan + LLOFP (mixed), p < 0.05 | The present invention provides a method of immunising a subject comprising the step of administering a composition comprising an antigen and a carbohydrate polymer comprising mannose to a mucosal site of the subject, methods of use of the composition for vaccination and sterilization and use of the composition in manufacturing a medicament. | 0 |
This is a continuation-in-part of pending application Ser. No. 09/098,013, filed Jun. 15, 1998, which is a divisional of Ser. No. 08/739,724, filed Nov. 7, 1996 now U.S. Pat. No. 5,810,836.
BACKGROUND OF THE INVENTION
1. Technical Field
This invention is generally directed to the fields of cardiac surgery and interventional cardiology, and particularly, to mechanical devices and methods suited for improving blood flow to a heart muscle by Trans Myocardial Revascularization (TMR).
2. Description of Related Art
Symptomatic occlusive coronary artery disease that does not respond to medical or interventional treatment is a major challenge for cardiac surgeons and cardiologists. The discovery of sinusoidal communications within the myocardium (Wearns, 1993) has motivated researchers to attempt various methods for myocardial revascularization based on the existence of this vascular mesh network. These methods aimed at the delivery of oxygenated blood to the vicinity of the sponge-like sinusoidal plexus in order to restore blood flow to the ischemic myocardium. Several investigators have attempted to deliver oxygenated blood directly from the left ventricle into the myocardial sinusoids by employing needle acupuncture to create transmural channels. Trans Myocardial Revascularization (TMR) has been employed clinically (Mirhoseini, 1991) by utilizing a CO2 laser for creating transmural channels in the left ventricular myocardium. These channels are typically 1 mm in diameter and extend throughout the wall thickness (15 to 20 mm) of the ventricle. It has been hypothesized that TMR works by providing a fluid conduit for oxygenated blood to flow from the endocardiac surface (heart chamber) to the mycardium inner layers thus providing oxygenated blood to myocardial cells without requiring coronary circulation; as in reptiles. Animal studies in the canine model have demonstrated the feasibility of this approach. In these studies, an increase in survival rate was demonstrated in dogs that had transmural channels and ligated coronary arteries.
While clinical studies have demonstrated improvements in patient status following TMR, histological studies indicate that the channels created for TMR tend to close shortly after the procedure. Randomized, prospective clinical trials are underway to examine the merit of TMR compared to medical treatment. In the meantime, research studies are being initiated to provide an understanding of the mechanism by which TMR actually works.
It would be desirable to develop means for maintaining the patency of TMR channels within the myocardium. Furthermore, it would be desirable to create channels for TMR without requiring the use of an expensive and bulky laser system, such as currently available CO2 laster systems. This invention provides the desired means for producing trans myocardial channels that are likely to remain patent, and that do not require laser application for generating these channels.
Specifically, the objective of the present invention is to generate needle-made channels or space in the ischemic heart wall, and to deliver or place in these channels (or space) an array of stents in order to provide improved means for supplying blood nutrients to ischemic myocardial tissue. Nutrients flow to the stented channels from the ventricular cavity, and diffuse from the side ports of the stent to the myocardial tissue through the needle-made channels. Our disclosed TMR approach of producing stented, needle-made, channels is supported by the recent scientific evidence (Whittaker et al, 1996) that needle-made transmural channels can protect ischemic tissue. Whittaker et al. assessed myocardial response at two months to laser and needle-made channels in the rat model which has little native collateral circulation. They found that channels created by a needle can protect the heart against coronary artery occlusion, and that these channels provide greater protection to ischemic tissue than channels created by laser. The limitation of needle-made channels is early closure (Pifarre, 1969). The disclosed stenting approach offers a possible solution to the early closure problem, while taking advantage of simple and effective needle-made channels for TMR.
SUMMARY OF THE INVENTION
This invention provides stent and needle means for creating and maintaining a patent lumen in the diseased myocardium. This stent provides a conduit for the flow of blood nutrients from the ventricular chamber to the intramyocardial vascular network. This stent can be used as the sole therapy or as an adjunctive therapy to other forms of TMR.
Revascularization of the myocardium can be achieved and maintained by creating stented, needle-made, channels within the myocardial tissue. These channels can allow blood nutrients within the left ventricular cavity to find direct access to ischemic zones within the ventricular wall independent of access through the coronary arteries.
Various configurations of the stent are disclosed; including flexible and rigid stents, screw stents, sleeve stents, and others. Manual or powered devices are disclosed for the delivery or placement of stents into a heart wall. The proximal end of the stent terminates at the epicardial surface and provides mechanical closure means to prevent stent detachment and leakage of blood from the ventricle. The stent is designed so as to maintain an adequate pressure gradient between the left ventricle and the myocardial tissue in order to maintain the flow from the ventricular cavity to the myocardial tissue of blood nutrients.
Furthermore, the disclosed TMR stent defines a cavity which can be pressurized during operation so as to enhance the flow of blood to myocardial tissue. Each stent can essentially operate as a mini-pump that is activated by myocardial contraction or by an external energy source.
Several embodiments of the stent and delivery systems therefor are proposed. The stents include the following: flexible spring, rigid sleeve, hollow screw, helical screw, and pumping (active) stent. The stents can be prestressed or made from memory metal in order to minimize the size of the stent during the insertion process. The various delivery systems are described below.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view of a TMR stent inserted in a heart wall. The stent is configured as an expandable coil spring having an integral anchoring wire;
FIG. 2 is a cross-sectional view of a TMR stent having the configuration of a rigid sleeve having side ports;
FIG. 3 is a cross-sectional view of a TMR stent having the configuration of a hollow screw with side ports;
FIG. 4 is a cross-sectional view of a TMR stent having the configuration of a wire screw;
FIG. 5 is a cross sectional view of a flexible stent having an integral anchoring coil;
FIG. 6 is a cross-sectional view of a TMR stent having the configuration of a miniature pump;
FIG. 7 shows a TMR delivery device and method for insertion of a TMR stent into a heart wall;
FIGS. 8A-8I illustrate an alternate TMR stent and a delivery system for insertion of this TMR stent into a heart wall;
FIG. 9 shows a catheter delivery device and method utilizing a percutaneous access for insertion of a TMR stent into a needle-made space within the heart wall;
FIG. 10 shows an alternate catheter delivery device and method utilizing a percutaneous access for creating a channel in the heart wall, and for insertion in this channel of a TMR stent;
FIG. 11 is a front elevational view of a system for delivery to a heart wall of an implant (myocardial stent);
FIG. 12 is a front elevational view, partly in cross section, of an obturator assembly having a needle assembly and sheath assembly;
FIG. 13 is a left end view of FIG. 13A;
FIG. 13A is an enlarged elevational view of the distal end of the needle assembly of FIG. 12, having a myocardial implant mounted on the needle assembly;
FIG. 14 is a side elevational view, partly in cross section, of an alternate embodiment of a needle assembly;
FIG. 15 is a front elevational view of the obturator assembly of FIG. 12, in position for removal from a heart wall following delivery of an implant;
FIG. 16 is a front elevational view of a further embodiment of an obturator for delivery of an implant to a heart wall;
FIG. 17 is an enlarged, partial cross sectional view of the needle end of the device shown in FIG. 16;
FIG. 18A is a further front elevational view of the obturator shown in FIG. 16, with a myocardial implant partially mounted on the needle end;
FIG. 18B is an enlarged elevational view of the mycardial implant and needle end of FIG. 18A;
FIG. 19 is an enlarged elevational view showing the myocardial implant of FIG. 18B, completely mounted on the needle end;
FIG. 20 is a further elevational view of the myocardial implant completely mounted on the needle end being inserted in a heart wall by rotation of the obturator;
FIG. 21 shows the obturator and myocardial implant fully inserted into the heart wall; and
FIG. 22 shows the obturator removed from the heart wall with the implant left in the heart wall.
DESCRIPTION OF PREFERRED EMBODIMENTS
The following description is provided to enable any person skilled in the art to make and use the invention, and sets forth the best modes contemplated by the inventor of carrying out his invention. Various modifications, however, will remain readily apparent to those skilled in the art, since the generic principles of the present invention have been defined herein specifically to provide an improved delivery system for stents.
FIG. 1 shows a flexible TMR stent (hereinafter "myocardial implant") having a coil spring body 21 defining a cavity 22 and spacing 23 between the turns of said spring body. In this embodiment, blood nutrients flow from the heart chamber 24 to the heart wall 25 by passage through the coil spring cavity 22 and spacing 23. An anchoring wire 65 secures the stent to the heart wall.
FIG. 2 shows a myocardial implant that comprises a tubular body 1, cavity 2, side ports 3, retainer 4, and closure 5. In this embodiment, blood nutrients 6 are transported from the heart chamber (ventricle) 7, through the cavity 2 and side ports 3, to the heart wall 8.
FIG. 3 shows a myocardial implant that is configured as a hollow screw having a threaded body 9, cavity 10, side ports 11, closure 12, and slot 15. In this embodiment, blood nutrients flow from the heart chamber 13 to the heart wall 14 by passage through the cavity 10 and side ports 11.
FIG. 4 shows a myocardial implant that is a hollow wire screw having an elongated hollow coil body 16, side ports 17, and anchor 18. In this embodiment, blood nutrients flow from the heart chamber 19 to the heart wall 20 by passage through the hollow core of the wire 16 and side ports 17.
FIG. 5 shows a flexible myocardial implant having a coil body 26 and an anchoring coil 27 which is an integral part of the myocardial implant. The anchoring coil prevents detachment of the myocardial implant from the heart wall.
FIG. 6 shows a myocardial implant having a cylindrical body 28 defining a cavity 29. A valve 30, pumping element 31, and side ports 32 are situated within the cavity 29. In this embodiment, blood nutrients flow from the heart chamber 33 to the pumping cavity 29. The valve 30 is activated and the pumping element 31 operates to displace the blood from the pumping cavity 29 through side ports 32 to the heart wall 34.
FIG. 7 shows the construction and method of use of one embodiment of a delivery device for creating a pathway in the heart wall and for placement of a myocardial implant in this pathway. In this first embodiment, a needle obturator 36 carries a myocardial implant 35 having an anchoring wire 37, which may be offset from the myocardial implant, as shown in FIG. 7, or aligned with the myocardial implant, as shown in FIGS. 18A-22. The obturator and myocardial implant are inserted through the heart wall 38 until the endocardiac surface is reached. After the endocardiac surface 39 of the heart wall is reached, the obturator 36 is removed, as by turning or unscrewing the same, thereby leaving the myocardial implant 35 embedded in the heart wall. Additional improvements include a fluid channel 66 that is formed in the obturator body to provide an indication that the obturator's distal end 67 has crossed the endocardiac surface 39.
FIGS. 8A through 8I show the construction of an alternate myocardial implant and a second embodiment of a delivery system for placement of the alternate implant in a heart wall. FIG. 8A shows a delivery system having a pin 40 and handle 41 having a locking device 42. An obturator 43 is mounted in the pin 40. The obturator 43 has a recess 44 (FIG. 8B) to engage the distal end of a myocardial implant 45. The pin 40 has a recess 46 (FIG. 8B) to engage the proximal end of the implant 45.
The method of use involves the placement of the implant 45 over an obturator 43. The pin 40 is then rotated to create a radial stress on the TMR device 45 (FIG. 8D). The pin 40 is locked to the handle 41 (FIG. 8C). Advancement through the heart wall 50 of the obturator and TMR device 45 is achieved by pressing the obturator through the heart wall (FIGS. 8E, 8F). The pin 40 is released from handle 41 by withdrawing the locking device 42 (FIGS. 8G, 8H). This causes the implant 45 to be released from the obturator 43. The obturator 43 is then pulled back from the heart wall 50 leaving the implant 45 imbedded in the heart wall (FIG. 8I).
FIG. 9 shows a catheter 58 having a slidable wire 59 which terminates at its distal end in a needle point 60. A myocardial implant 61 is mounted proximal to the needle point. Advancing the needle spreads the heart wall tissue and positions the implant 61 into that tissue. Withdrawal of the needle releases the implant 61 in the heart wall.
FIG. 10 shows a catheter 62 which incorporates a slidable wire 63 that terminates at its distal end into a drill or other mechanical attachment 65 for making holes in the heart wall tissue. A myocardial implant 64 is mounted proximal to the drill 65 on the slidable wire 63. Advancing the drilling tool creates a channel in the tissue and positions the implant 64 in this channel. Withdrawal of the drilling tool releases the implant 64 in the heart wall.
The disclosed myocardial implants are expected to incorporate a cavity having a diameter in the range of 1-5 millimeters and a length in the range of 10-30 millimeters. The bodies of the myocardial implants are made of a bio-compatible material; such as stainless steel. The myocardial implants may also be coated with a material that promotes angiogenesis (formation of new blood vessels). The myocardial implants may also be made from carbon, gold, platinum, or other suitable materials.
The number of myocardial implants required of used for each patient depends on the size of the implants and the surface area of the heart segment that is being revascularized. For example, a small segment may require only one myocardial implant, while a large segment may require 10 implants to be implanted in the heart wall.
Turning now to FIGS. 11-22, there shown are alternate embodiments of delivery systems for implanting myocardial implants in a heart wall.
FIG. 11 illustrates a system for the delivery to a heart wall of a myocardial implant. This system consists of a thoracoscope 66 and an obturator assembly 67. The thoracoscope provides means for optical guidance in order to permit minimally-invasive access to the heart wall. The system allows penetration of the chest wall of a patient between ribs 68, to allow the obturator assembly 67 to penetrate the heart wall 69, and leave the implant in the heart wall.
FIG. 12 shows an enlarged cross section of a preferred embodiment of an obturator assembly, such as 67, having a needle assembly 70 and a sheath assembly 71. The needle assembly 70 contains, at its proximal end a handle 72, and at its distal end, a needle tip 73. A needle shaft 74 connects the proximal and distal of the needle assembly 70. The needle shaft contains a groove 75 and a plurality of holes or openings 76 to removably couple the needle shaft to the outer sheath assembly 71 during use. A pin 77 is mounted proximal to needle tip 73 in order to support a myocardial implant, and to permit the implant to be threaded into heart wall tissue. The sheath assembly 71 contains, at its proximal end, a handle 78 that is connected to tubing 79. The distal end of the tubing 79 is shaped to form a key or holding portion 80 that provides means for locking the myocardial implant onto the sheath. A further holding element or pin 81 provides means for coupling the sheath assembly to the needle assembly. A spring 82 supports the pin 81 and a stop 83 provides means to hold the pin 81 in place. A slot 84 provides means to place pin 81 in a locking during use. A pin 77 is mounted proximal to needle tip 73 in order to support a myocardial implant, and to permit the implant to be threaded into heart wall tissue. The sheath assembly 71 contains, at its proximal end, a handle 78 that is connected to tubing 79. The distal end of the tubing 79 is shaped to form a key or holding portion 80 that provides means for locking the myocardial implant onto the sheath. A further holding element or pin 81 provides means for coupling the sheath assembly to the needle assembly. A spring 82 supports the pin 81 and a stop 83 provides means to hold the pin 81 in place. A slot 84 provides means to place pin 81 in a locking position. A spring-loaded pin 86 provides means to engage or lock the needle assembly 70 to the sheath assembly 71, during removal of the obturator assembly 67 from a human body.
FIG. 13A is an enlarged view of the distal end of a needle assembly, such as 70, having a myocardial implant 87 mounted on the needle assembly. The proximal end of the implant is secured onto the sheath assembly, with the key 80 locking or holding a portion 88 of the implant, to prevent rotation of the implant during insertion and withdrawal of needle assembly from a heart wall.
FIG. 13 is a left end view of FIG. 13A, and shows the implant 87 secured to the key 80 by the locking portion 88 of the implant.
FIG. 14 shows a further embodiment of a delivery system, having a modified needle assembly. In this configuration, the distal end of the needle assembly is made detachable from the rest of the assembly, as by means of a mechanical coupling 89.
FIG. 15 is a further cross section of the obturator assembly shown in FIG. 12, with the needle assembly in a retracted position for removal from a heart wall, following delivery of an implant. In this retracted position, the locking pin 83 is seated in a groove 90, and the spring-loaded pin 86 is engaged in groove 75.
Referring now to FIGS. 16-22, there shown is yet another embodiment of the delivery system of the present invention.
FIG. 16 shows a delivery device (obturator) 91, having a distal end and a proximal end 92, for delivery of an implant to a heart wall.
FIG. 17 is an enlarged cross section of the distal end of the obturator device 91, shown in FIG. 16. This device includes a needle assembly 96, having a needle tip 93, used to puncture tissue, a pin 94 used to thread and support an implant, a port 95, which is in fluid communication with an internal conduit 97 and an indicator tube 98. The port 95 allows blood inside a heart to enter internal conduit 97 and to exit though an internal conduit indicator tube 98, in order to demonstrate complete penetration of the heart wall by the obturator.
FIG. 18A shows a myocardial implant 99 partially mounted on the distal end of the obturator 91, while FIG. 18B shows an enlarged view of the myocardial implant 99 and the distal end of the obturator 91. As discussed above, the pin 94 engages the implant 99 opposite from the port 95.
FIG. 19 shows the myocardial implant 99 completely mounted on the distal end of the obturator 91, in position for insertion into a heart wall.
FIG. 20 illustrates how the myocardial implant 99 is inserted into a heart wall 100 by rotation of the obturator 91.
FIG. 21 illustrates the implant 99 inserted completely into the heart wall 100, while it is still held on the obturator 91.
Finally, FIG. 22 shows the implant 99 inserted into the heart wall 100, with the obturator 91 withdrawn.
Those skilled in the art will appreciate that various adaptations and modifications of the just-described preferred embodiments can be configured without departing from the scope and spirit of the invention. Therefore, it is to be understood that, within the scope of the appended claims, the invention may be practiced other | A delivery device for insertion of a myocardial implant into a heart wall for trans myocardial revascularization (TMR) of the heart wall. The delivery device provides for the exact placement of one or more TMR implants into a heart wall, and has an elongated, tubular body that may include spaced-apart ports and a connecting conduit. A needle point is formed at one end to pierce the heart wall, and a handle is formed at another end to manipulate the device. The delivery device may include a surrounding sheath into which the needle point and a needle assembly may be withdrawn to release the TMR implant in the heart wall, and withdraw the delivery device from a person's body. The sheath may include a locking portion for holding the TMR implant in position when releasing the implant in a heart wall. | 0 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a wet-type multi-plate friction engaging apparatus in a clutch or a brake of an automatic transmission of a motor vehicle, a lock-up clutch, a starting clutch and the like.
[0003] 2. Related Background Art
[0004] A wet-type multi-plate clutch i.e. wet-type multi-plate friction engaging apparatus comprising paper friction materials has various advantages that torque to be transmitted can be controlled on the basis of a load applied to a friction surface and that permits smooth engagement during the transmission of torque and is used mainly and widely in speed changing devices of automatic transmissions, torque converters, starting clutches or the like. One example of such starting clutches is shown in Japanese Patent Application Laid-Open No. 2006-105397.
[0005] Excellent heat resistance and smooth engagement is required for the wet-type multi-plate clutch used in the automatic transmission.
[0006] A conventional wet-type multi-plate friction engaging apparatus is constituted as shown in FIG. 12 . The conventional wet-type multi-plate friction engaging apparatus 100 comprises internally toothed plates 105 each of which is obtained by sticking paper friction materials 104 onto both surfaces of a metal plate, externally toothed plates 106 formed from metal plates, the plates 105 and 106 being arranged alternately within a clutch drum 101 , a piston 107 for urging the internally toothed plates 105 and the externally toothed plates 106 against each other, a backing plate 103 , and a snap ring 102 for supporting the internally toothed plates 105 , externally toothed plates 106 and backing plate 103 .
[0007] In the above-mentioned conventional apparatus, since camber deformation of each plate and warping deformation of the clutch drum 101 are generated by the urging of the piston 107 , there is a tendency that face pressure on the friction surface becomes greater at an outer diameter side than at an inner diameter side toward the opening end of the clutch drum 101 . Such a tendency becomes more noticeable as rigidity of the clutch drum 101 is decreased and as a thickness of the backing plate 104 is decreased, and, in particular, the outer diameter side face pressure on the friction material 104 at the opening end of the clutch drum 101 becomes greater. As a result, since the whole surface of each friction plate 104 does not work effectively, heat resistance may be reduced and smooth movements of the plates may be prevented, thereby affecting a bad influence upon the engaging property.
[0008] Further, in recent years, as light weight, increase in stages of the automatic transmission and reduction of cost have been requested, weights of the clutch drum and the backing plate are requested to be reduced and, at the same time, burning or baking of the clutch has been increased because of rotation at high speed.
SUMMARY OF THE INVENTION
[0009] Thus, an object of the present invention is to provide a wet-type multi-plate friction engaging apparatus in which, by designing so that load acting positions on plates at a piston side and at piston-opposite side are positioned in the vicinity of centers of the plates, whole engaging faces of friction surfaces of all of the plates are contacted with each other with uniform face pressure to prevent offset of heat generating areas produced in the course of the friction engagement, whereby a heat-resisting ability of a clutch portion is enhanced.
[0010] To achieve the above object, according to the present invention, there is provided a wet-type multi-plate friction engaging apparatus comprising a clutch portion including internally toothed plates having at least one axial surface on which a friction material is provided and externally toothed plates arranged alternately with the internally toothed plates in an axial direction, and a piston adapted to apply an urging force for engaging the internally toothed plates and the externally toothed plates with each other, and wherein load acting portions acting on the clutch portion are arranged on both sides of the clutch portion, and a contact area of the load acting portion through which the load acting portion is contacted with the clutch portion is located in a predetermined range between about 20% of a radial width of a friction engaging portion from a central position of the friction engaging portion in an outer diameter direction and about 20% of the radial width of the friction engaging portion in an inner diameter direction, and a radial width of the contact area is smaller than about 10% of the radial width of the friction engaging portion.
[0011] With this arrangement, since the load is applied to the friction surfaces in the vicinity of the centers thereof during the engagement, the plates can be moved smoothly during the engagement, thereby providing the smooth engaging property. Further, since the transmitting efficiency of the clutch portion is enhanced and torque capacity is increased, the equivalent torque can be transmitted with the fewer number of friction plates, in comparison with the prior art.
[0012] Since the contact area is located in the range between about 20% of the width of a friction engaging portion (a range between an outermost diameter position and an innermost diameter position of the friction engagement) from the central position of the friction engaging portion in the outer diameter direction and about 20% of the width of the friction engaging portion in the inner diameter direction, and since the radial width of the contact area is smaller than about 10% of the radial width of the friction engaging portion, the face pressures of various plates within the clutch can be made uniform and variation in face pressure distribution between clutch plates can be reduced, thereby providing a heat-resistive wet-type multi-plate friction engaging apparatus having a stable speed changing performance.
[0013] Further, by forming the load acting portion as the curved surface, a more stable and more uniform load can be applied through the friction surface. The protruded portion may be formed by a cutting operation or a pressing operation or may be formed by mounting a separate part to the piston or the plate member. The load acting portion or the protruded portion may also have a cushioning function and/or a stop ring function. In this case, a more reliable wet-type multi-plate friction engaging apparatus can be provided.
[0014] Now, with reference to FIG. 11 , some of terms used in embodiments and claims in this application will be defined. For convenience's sake, although such terms are defined on the basis of an embodiment shown in FIG. 1 , it should be noted that such terms can be used in common in all of claims, embodiments and modifications. In FIG. 11 , a protrusion 12 provided in a piston 7 has a rectangular cross-section and is in contact with an outer tooth plate 6 with a rectangular end surface to define a contact area.
[0015] A contact area LP of each of load acting portions acting on a clutch portion at both axial sides of the clutch portion comprising internally toothed plates and externally toothed plates is located within a predetermined range R between about 20% of a width W of a friction engaging portion from a central position CP of the friction engaging portion in an outer diameter direction and about 20% of the width W of the friction engaging portion in an inner diameter direction, and a width of the contact area LP is selected to be smaller than about 10% of the width W of the friction engaging portion.
[0016] The “friction engaging portion” means a range an outermost diameter position of friction engagement and an innermost diameter position of the friction engagement, and the “width of friction engaging portion” is substantially equal to a radial width of the friction material. The “predetermined range” means a range between 20% of the width of the friction engaging portion from the central position CP of the friction engaging portion in the inner and outer diameter directions, respectively.
[0017] Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is an axial partial sectional view of a wet-type multi-plate friction engaging apparatus according to a first embodiment of the present invention.
[0019] FIG. 2 is an axial partial sectional view of a wet-type multi-plate friction engaging apparatus according to a second embodiment of the present invention.
[0020] FIG. 3 is an axial partial sectional view of a wet-type multi-plate friction engaging apparatus according to a third embodiment of the present invention.
[0021] FIG. 4 is an axial partial sectional view of a wet-type multi-plate friction engaging apparatus according to a fourth embodiment of the present invention.
[0022] FIG. 5 is an axial partial sectional view of a wet-type multi-plate friction engaging apparatus according to a fifth embodiment of the present invention.
[0023] FIG. 6 is an axial partial sectional view of a wet-type multi-plate friction engaging apparatus, showing an alteration of a plate member.
[0024] FIG. 7 is an axial partial sectional view of a wet-type multi-plate friction engaging apparatus, showing another alteration of a plate member.
[0025] FIG. 8 is an axial partial sectional view of a wet-type multi-plate friction engaging apparatus, showing a further alteration of a plate member.
[0026] FIG. 9 is a front view of the plate member of FIG. 8 .
[0027] FIG. 10 is an axial partial sectional view of a wet-type multi-plate friction engaging apparatus, showing an example of a load acting portion provided on a piston.
[0028] FIG. 11 is an axial partial sectional view of a wet-type multi-plate friction engaging apparatus, for explaining terms used in this specification.
[0029] FIG. 12 an axial partial sectional view of a conventional wet-type multi-plate friction engaging apparatus.
[0030] FIG. 13 is a schematic view showing face pressure distribution on a friction material secured to a plate near a clutch opening portion, according to the embodiment of the present invention.
[0031] FIG. 14 is a schematic view showing face pressure distribution on a friction material secured to a plate near a clutch opening portion, according to a prior art.
DETAILED DESCRIPTION OF THE INVENTION
[0032] Now, embodiments of the present invention will be explained with reference to the accompanying drawings. Incidentally, various embodiments which will be described below are merely examples and do not limit the present invention in all senses.
[0033] FIGS. 1 to 5 are axial partial sectional views showing wet-type multi-plate friction engaging apparatuses according to first to fifth embodiments of the present invention, respectively. FIG. 1 shows a first embodiment in which a wet-type multi-plate friction engaging apparatus 10 comprises a substantially cylindrical clutch drum 1 opened at its axial one end (right end in FIG. 1 ), a hub 9 disposed within the clutch drum 1 and rotatable coaxially with and relative to the clutch drum, annular externally toothed plates 6 mounted in splines formed in an inner peripheral surface of the clutch drum 1 for shifting movement in an axial direction, and annular internally toothed plates 5 mounted in splines 9 a formed in an outer peripheral surface of the hub 9 and disposed alternately with the externally toothed plates 6 in the axial direction and each having both axial surfaces to which friction materials 4 are adhered. There are plural externally toothed plates 6 and plural internally toothed plates 5 .
[0034] The wet-type multi-plate clutch 10 includes a piston 7 for urging the externally toothed plates 6 and the internally toothed plates 5 which constitute a clutch portion to engage these plates with each other, and a plate member or backing plate 3 provided on the inner peripheral surface of the clutch drum 1 to hold the externally toothed plates 6 and the internally toothed plates 5 at one end in the axial direction and a stop ring 2 for holding the backing plate.
[0035] As shown in FIG. 1 , the piston 7 is mounted within a closed end portion of the clutch drum 1 for axial sliding movement. An O-ring 8 is disposed between an outer peripheral surface of the piston 7 and the inner peripheral surface of the clutch drum 1 . Further, a sealing member (not shown) is disposed between an inner peripheral surface of the piston 7 and an outer peripheral surface of a cylindrical portion (not shown) of the clutch drum 1 . Accordingly, an oil-tight hydraulic chamber (not shown) is defined between an inner surface of the closed end portion of the clutch drum 1 and the piston 7 . Further, the hub 9 is provided with a lubricating oil supply port (not shown) passing through the hub so that the lubricating oil is supplied from inner diameter side to an outer diameter side of the wet-type multi-plate clutch 10 .
[0036] In the wet-type multi-plate clutch 10 so constructed, engagement and disengagement of the clutch are achieved in the following manner. A condition shown in FIG. 1 is a clutch engaging condition in which the externally toothed plates 6 and the internally toothed plates 5 are contacted with each other. Incidentally, in a clutch disengaging condition, the piston 7 is displaced toward the closed end of the clutch drum 1 by a biasing force of a return spring (not shown).
[0037] In order to achieve the engagement of the clutch from the disengaging condition, hydraulic pressure is supplied to the hydraulic chamber (not shown) defined between the piston 7 and the clutch drum 1 . As the hydraulic pressure is increased, the piston 7 is shifted to the right in FIG. 1 in the axial direction in opposition to the biasing force of the return spring (not shown), thereby closely contacting the externally toothed plates 6 and the internally toothed plates 5 with each other. In this way, the clutch is engaged.
[0038] After the engagement, in order to release or disengage the clutch again, the hydraulic pressure is released from the hydraulic chamber. When the hydraulic pressure is released, by the biasing force of the return spring (not shown), the piston 7 is displaced toward the closed end of the clutch drum 1 , thereby disengaging the clutch.
[0039] FIG. 1 is an axial partial sectional view of the wet-type multi-plate friction engaging apparatus according to the first embodiment of the present invention. In the first embodiment shown in FIG. 1 , load acting portions are provided on the piston 7 and the backing plate 3 . A protrusion 11 as the load acting portion is formed on an urging surface 7 a of the piston 7 which confronts the clutch portion. The protrusion 11 is formed as a semi-spherical configuration extending in the axial direction. Accordingly, when the piston 7 applies an urging force to the clutch portion, a curved surface of the protrusion 11 abuts against a metallic surface of the externally toothed plate 6 .
[0040] Further, a protrusion 12 as the load acting portion is formed on a surface 3 a (which confronts the clutch portion) of the backing plate 3 arranged at a position opposed to the piston 7 with the inter position of the clutch portion in the axial direction. The protrusion 12 is formed as a semi-spherical configuration extending in the axial direction. Accordingly, when the piston 7 applies the urging force to the clutch portion, a metallic surface of the externally toothed plate 6 abuts against a curved surface of the protrusion provided on the stationary backing plate 3 . The protrusion 11 is formed integrally with the piston 7 and the protrusion 12 is formed integrally with the backing plate 3 .
[0041] In order to satisfy the relationships described with reference to FIG. 11 , the protrusions 11 and 12 are formed so that they are positioned on a substantially the same single straight line parallel with a central axis of the clutch portion. Accordingly, upon engagement, since the load acts on the central portions of the friction surfaces, the plates are smoothly moved during the engagement, thereby providing a smooth engaging property. Further, since a transmitting efficiency of the clutch portion is enhanced to increase a torque capacity, torque same as that in the prior art can be transmitted with the fewer number of friction plates.
[0042] FIG. 2 is an axial partial sectional view of a wet-type multi-plate friction engaging apparatus according to a second embodiment of the present invention. In FIG. 2 , members on which the load acting portions are provided differ from the members in the first embodiment. The load acting portions are provided on both outermost externally toothed plates 6 in the axial direction of the clutch portion. A protrusion 14 is formed on a surface (opposed to the urging surface 7 a of the piston 7 ) of the externally toothed plate 6 adjacent to the piston 7 . The protrusion 14 is formed as a semi-spherical configuration extending in the axial direction. Accordingly, when the piston 7 applies the urging force to the clutch portion, a curved surface of the protrusion 14 abuts against the urging surface 7 a of the piston 7 .
[0043] On the other hand, a protrusion 15 is formed on a surface (opposed to the backing plate 3 ) of the externally toothed plate 6 adjacent to the backing plate 3 . The protrusion 15 is formed as a semi-spherical configuration extending in the axial direction. Accordingly, when the piston 7 applies the urging force to the clutch portion, a curved surface of the protrusion 15 abuts against the surface 3 a of the backing plate 3 . Also in this embodiment, so as to satisfy the relationships described with reference to FIG. 11 , the protrusions 14 and 15 are formed so that they are positioned on a substantially the same single straight line parallel with the central axis of the clutch portion. The protrusion is formed integrally with externally toothed plate adjacent to the backing plate and the protrusion 14 is formed integrally with the externally toothed plate adjacent to the piston 7 .
[0044] FIG. 3 is an axial partial sectional view of a wet-type multi-plate friction engaging apparatus according to a third embodiment of the present invention. In the third embodiment, protrusions as the load acting portions are provided separately. A protrusion member 16 is fixedly fitted into a recessed portion 7 b formed in the urging surface 7 a of the piston 7 . Further, the backing plate 3 is provided with a recessed portion 3 b similarly and a protrusion member 17 is fixedly fitted into the recessed portion 3 b.
[0045] Both of the protrusion members 16 and 17 are formed as semi-spherical configurations having distal ends extending in the axial direction.
[0046] Also in the third embodiment, so as to satisfy the relationships described with reference to FIG. 11 , the protrusions 14 and 15 are formed so that they are positioned on a substantially the same single straight line parallel with the central axis of the clutch portion. When the piston 7 exerts the urging force to engage the clutch, a curved surface of the distal end of the protrusion member 16 abuts against the metallic surface of the externally toothed plate 6 and a curved surface of the distal end of the protrusion member 17 also abuts against the metallic surface of the externally toothed plate 6 .
[0047] FIG. 4 is an axial partial sectional view of a wet-type multi-plate friction engaging apparatus according to a fourth embodiment of the present invention. In this embodiment, although the construction of the load acting portions is substantially the same as that of the second embodiment, a construction of friction materials differs from that of the second embodiment. In this embodiment, each friction material is provided on one surface of each of the internally toothed plates 5 and the externally toothed plates 6 . The friction material 24 is adhered to a left surface ( FIG. 4 ) of each externally toothed plate 6 and the friction material 4 is adhered to a left surface of each internally toothed plate 5 . Accordingly, when such internally toothed plates 5 and externally toothed plates 6 are alternately arranged along the axial direction, as shown in FIG. 4 , except both end plates, the friction materials are located on both surfaces of each plate.
[0048] The protrusions as the load acting portions have substantially the same construction as that in the second embodiment, in which a protrusion 18 is formed integrally with the surface (opposed to the urging surface 7 a of the piston 7 ) of the externally toothed plate 6 adjacent to the piston 7 . The protrusion 18 is formed as a semi-spherical configuration extending in the axial direction. Accordingly, when the piston 7 applies the urging force to the clutch portion, a curved surface of the protrusion 18 abuts against the urging surface 7 a of the piston 7 .
[0049] On the other hand, a protrusion 19 is formed integrally with a surface (opposed to the backing plate 3 ) of the externally toothed plate 6 adjacent to the backing plate 3 . The protrusion 19 is formed as a semi-spherical configuration extending in the axial direction. Accordingly, when the piston 7 applies the urging force to the clutch portion, a curved surface of the protrusion 19 abuts against the surface 3 a of the backing plate 3 . Also in this embodiment, so as to satisfy the relationships described with reference to FIG. 11 , the protrusions 18 and 19 are formed so that they are positioned on a substantially the same single straight line parallel with the central axis of the clutch portion.
[0050] FIG. 5 is an axial partial sectional view of a wet-type multi-plate friction engaging apparatus according to a fifth embodiment of the present invention. In this embodiment, a construction of load acting portions differs from those in the first to fourth embodiments. A protrusion 22 as a load acting portion is formed integrally with an inner surface 31 a of a closed end of a clutch drum 31 and is opposed to the externally toothed plate 6 . The protrusion 22 is formed as a semi-spherical configuration extending in the axial direction.
[0051] On the other hand, a protrusion 21 is formed integrally with an urging surface 37 a (opposed to the externally toothed plate 6 ) of a piston 37 disposed within the closed end portion of the clutch drum 31 . The protrusion 21 is formed as a semi-spherical configuration extending in the axial direction.
[0052] The other constructions are similar to these in the first to third embodiments. So as to satisfy the relationships described with reference to FIG. 11 , the protrusions 21 and 22 are formed so that they are positioned on a substantially the same single straight line parallel with the central axis of the clutch portion.
[0053] FIG. 6 is an axial partial sectional view of a wet-type multi-plate friction engaging apparatus, showing an alteration of a plate member. A plate member or backing plate 33 arranged at an opposite side from the piston 7 with the interposition of the clutch portion is provided at its radial middle part with a curved (curvilinear) bent portion 34 protruding toward the externally toothed plate 6 . An apex 35 is formed on the curved bent portion 34 to direct toward the externally toothed plate 6 . The apex has a function corresponding to the protrusions in the above-mentioned various embodiments. When the piston (not shown in FIG. 6 ) applies the urging force to the clutch portion, the right surface of the rightmost externally toothed plate 6 urged by the piston abuts against a curved surface of the apex 35 . Incidentally, a protrusion provided on or near the piston 7 (piston side protrusion) may be the same as those in the previous embodiments. The apex 35 and the piston side protrusion are formed so that they are positioned on a substantially the same single straight line parallel with the central axis of the clutch portion.
[0054] FIG. 7 is an axial partial sectional view of a wet-type multi-plate friction engaging apparatus, showing another alteration of a plate member. A plate member or backing plate 36 arranged at an opposite side from the piston 7 with the interposition of the clutch portion is provided at its radial middle part with a straightly bent portion 37 protruding toward the externally toothed plate 6 . An apex 38 is formed on the straightly bent portion 37 to direct toward the externally toothed plate 6 . The apex has a function corresponding to the protrusions in the above-mentioned various embodiments. When the piston (not shown in FIG. 7 ) applies the urging force to the clutch portion, the right surface of the rightmost externally toothed plate 6 urged by the piston abuts against an ridge line of the apex 38 . Incidentally, a protrusion provided on or near the piston 7 (piston side protrusion) may be the same as those in the previous embodiments. The apex 38 and the piston side protrusion are formed so that they are positioned on a substantially the same single straight line parallel with the central axis of the clutch portion.
[0055] FIG. 8 is an axial partial sectional view of a wet-type multi-plate friction engaging apparatus, showing a further alteration of a plate member. A plate member or backing plate 39 arranged at an opposite side from the piston 7 with the interposition of the clutch portion is provided at its radial middle part with a bent portion 40 . An apex 41 is formed on the bent portion 40 to direct toward the externally toothed plate 6 . The apex 41 of the bent portion 40 has a function corresponding to the protrusions in the above-mentioned various embodiments. When the piston (not shown in FIG. 8 ) applies the urging force to the clutch portion, the right surface of the rightmost externally toothed plate 6 urged by the piston abuts against the apex 41 . The apex 41 and a piston side protrusion are formed so that they are positioned on a substantially the same single straight line parallel with the central axis of the clutch portion.
[0056] In FIG. 8 , since the backing plate 39 also acts as the stop ring 2 , the stop ring 2 is omitted. A radially outward end 42 of the backing plate 39 is fitted into an annular groove 1 b formed in the inner peripheral surface of the clutch drum 1 . Accordingly, due to the engagement between the apex 41 of the backing plate 39 and the externally toothed plate 6 , the clutch portion can be prevented from being dislodged along the axial direction and the urging force can be applied to the clutch portion between the piston 7 and the backing plate.
[0057] FIG. 9 is a front view of the backing plate 39 of FIG. 8 . The backing plate 39 having a C-shaped configuration has C-shaped annular ends 42 obtained by partially cutting along a circumferential direction. From the annular ends 42 , along an inner peripheral surface of the backing plate, there are provided a plurality of protruded portions 43 having the bent portions 40 . The protruded portions 43 are distributed substantially equidistantly along the circumferential direction.
[0058] FIG. 10 is an axial partial sectional view of a wet-type multi-plate friction engaging apparatus, showing an example of a load acting portion provided in connection with the piston. An annular protrusion 7 c is provided on a surface (opposed to the externally toothed plate 6 ) of the piston 7 , and a dish-shaped spring 44 is mounted around the protrusion 7 c. The dish-shaped spring 44 acts as a load acting portion which abuts against the externally toothed plate 6 . In place of the dish-shaped spring 44 , another biasing member such as a coil spring and the like may be used.
[0059] FIG. 13 is a schematic view showing face pressure distribution on a friction material secured to a plate near a clutch opening portion, according to the embodiment of the present invention. Further, FIG. 14 is a schematic view showing face pressure distribution on a friction material secured to a plate near a clutch opening portion, according to a prior art.
[0060] As shown in FIG. 13 , according to the embodiment of the present invention, as apparent from pressure marks 50 shown, uniform face pressure distribution can be obtained from an outer diameter side to an inner diameter side, with the result that face pressures of the plates within the clutch portion can be made uniform and dispersion in face pressure distribution between the clutch plates can be minimized, thereby providing a heat-resistive wet-type multi-plate friction engaging apparatus having stable speed change performance.
[0061] To the contrary, from FIG. 14 showing the prior art, it can be seen that pressure marks 50 are offset toward an outer diameter side not to provide uniform face pressure distribution. That is to say, it can be seen that the face pressure on the friction material within the clutch opening at the outer diameter side is greater than that in the inner diameter side. Accordingly, since the whole surface of the friction material does not work effectively, the heat-resistance may be deteriorated and smooth movements of the respective plates may be prevented during the engagement and a bad influence may be affected upon the engaging ability.
[0062] In the embodiments of the present invention as mentioned above, the protrusions may be provided as annular members on the piston or the plate member. The annular member may be continuous or discontinuous.
[0063] While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
[0064] This application claims the benefit of Japanese Patent Application No. 2007-054120, filed Mar. 5, 2007, which is hereby incorporated by reference in its entirety. | The present invention provides a wet-type multi-plate friction engaging apparatus comprising a clutch portion including internally toothed plates and a piston adapted to apply an urging force for engaging the internally toothed plates and wherein load acting portions acting on the clutch portion are arranged on both sides of the clutch portion, and a contact area of the load acting portion through which the load acting portion is contacted with the clutch portion is located in a predetermined range between about 20% of a radial width of a friction engaging portion from a central position of the friction engaging portion in an outer diameter direction and about 20% of the radial width of the friction engaging portion in an inner diameter direction, and a radial width of the contact area is smaller than about 10% of the radial width of the friction engaging portion. | 5 |
This application claims the benefit of Provisional Application No. 60/231,010 filed Sep. 8, 2000.
FIELD OF THE INVENTION
This invention is directed generally to substituted hydrazine derivatives and pharmaceutically acceptable salts thereof. The compounds are inhibitors of high affinity glycine transporters and are thus useful in treating neurological disorders including schizophrenia, dementia, epilepsy, muscle spasticity, mood disorders, learning disorders, neurodegenerative diseases and pain.
BACKGROUND OF THE INVENTION
Glycine acts as a neurotransmitter at two distinct receptor systems. In the spinal cord and certain non-cerebral brain regions, glycine acts much like GABA (γ-amino-n-butyric acid) in causing the opening of an inhibitory Cl − channel. This activity is mediated by the “strychnine-sensitive” glycine receptor. Glycine also acts as a co-agonist at the NMDA (N-methyl-D-aspartate) glutamate receptor that is localized in the cognitive centers of the brain, including the cortex, hippocampus, and basal ganglia. This receptor has received considerable attention from the pharmaceutical industry since there is compelling evidence that it plays a critical role in learning and cognition. Furthermore, excessive stimulation of the NMDA receptor appears to be responsible for much of the neuronal damage that occurs after stroke-injury and brain trauma. Hence, there are ongoing research efforts to develop both agonists (for increased cognition) and antagonists (for treatment of stroke) to the NMDA receptor.
Recent data suggest that agonists and antagonists to the glutamate site of the NMDA receptor can cause relatively severe side-effects. For example, NMDA antagonists have been shown to cause agitation, hallucinations, and paranoia in stroke patients. Agonists to the glutamate binding site on NMDA receptors have the potential of causing excessive calcium influx and excitotoxic cell damage. In contrast, the glycine site on the NMDA receptor appears to play a modulatory role, and therefore compounds interacting with this site do not appear to evoke such severe side-effects.
Demonstration that Glycine Modulation Improves Cognition
Evidence that molecules acting at the glycine site of the NMDA receptor can effectively enhance receptor activity is provided by several studies showing that glycine agonists or partial agonists are cognitive enhancers in vivo. D-cycloserine, a molecule that crosses the blood-brain barrier and which is a partial agonist at the NMDA glycine site, increased the performance of rats in a learning task model. In fact, D-cycloserine was reported to improve the implicit memory performance in a word recall test in Alzheimer's disease patients. However, because D-cycloserine is only a partial agonist at the glycine site, it may be more useful as an antagonist to the NMDA receptor.
A larger number of studies have been performed with the glycine prodrug, milacemide. This molecule (2-N-pentylaminoacetamide HCl) readily crosses the blood-brain barrier and is metabolized by monoamine oxidase B (MAO-B) to glycinamide. The latter is converted to glycine, which then acts at the NMDA receptor. Milacemide improved the performance of rats in a passive-avoidance task and reversed drug-induced amnesia. This compound has also been shown to improve performance in the Morris water maze task and to increase word retrieval skills in young and elderly healthy human adults. Unfortunately, the effectiveness of the drug wanes after continuous administration because the compound leads to irreversible inactivation of MAO-B, thus blocking the drug's own metabolism. Nonetheless, the data obtained with this compound and D-cycloserine demonstrate that increasing the occupancy of the glycine site of the NMDA receptor results in enhanced cognitive performance in animals and humans without side-effects.
The NMDA Receptor in Schizophrenia
The general view has been that schizophrenia primarily results from hyperfunctioning of the dopaminergic system. The typical anti-psychotics, such as thorazine and haloperidol, are relatively potent dopamine D2 receptor antagonists. In fact, there is a general correlation between clinical efficacy of the classical anti-psychotics (or neuroleptics) and their affinity for the D2 receptor. Further evidence of the importance of the dopaminergic system in schizophrenia is provided by studies showing that dopamine agonists, or agents that increase dopamine levels (like amphetamines), induce psychotic behavior.
While the role of dopamine in schizophrenia is well established, there are compelling reasons to believe that the disorder does not result solely from hyperfunctioning of this neurotransmitter system. For example, although amphetamine-induced psychosis includes certain “positive” symptoms such as delusions, hallucination and agitation, common “negative” aspects of schizophrenia, including emotional withdrawal and mental retardation, are not observed. Perhaps the best indication that the dopamine hypothesis is an over-simplified explanation of schizophrenia is the observation that individuals who have taken excessive phencyclidine (PCP) are clinically indistinguishable from schizophrenics. PCP acts as a selective noncompetitive blocker of the glutamate NMDA receptor at concentrations that induce psychosis, with no apparent effect on dopamine binding. Interestingly, PCP and ketamine (another NMDA channel-blocker) also exacerbate the psychosis of schizophrenic patients, whereas the psychomimetic effects of amphetamine are reduced in schizophrenics. These data imply that schizophrenia results from glutamate hypoactivity in addition to dopamine hyperfunction. Since most schizophrenic patients have some form of information processing deficit also implies that NMDA receptor function may be compromised in this disorder.
Although the available anti-psychotics primarily affect dopaminergic neurotransmission, there is some evidence that they may also have a modest effect on the glutaminergic system. Both haloperidol and clozapine cause an ˜40% increase in NMDA receptor activity in vitro at concentrations at which clinical efficacy is seen. Thus, some of their anti-psychotic activity may result from action on the NMDA receptor. The most compelling demonstration of glutamate hypofunction in schizophrenia would be clinical evidence that NMDA agonists improve patient outcome. Small clinical studies have been performed with D-cycloserine, and initial indications are that the compound may improve the negative symptoms and cognitive deficits of schizophrenia. That effects are seen with this partial agonist suggests that full glycine agonists may be particularly efficacious. Of particular interest are clinical studies in which schizophrenics were treated with large oral doses of glycine or placebo. Even though glycine does not penetrate the blood-brain barrier effectively, the patients receiving the glycine treatment showed a statistically significant decrease in negative schizophrenic symptoms.
Modulation of NMDA Receptor Activity Trough Inhibition of Glycine Transporters
An approach to enhancing NMDA receptor action is to increase glycine concentrations at the synaptic cleft by inhibiting its removal. While regulation of the transporters for the biogenic amines has been extensively studied, relatively little is known about the types of molecules that inhibit the glycine transporters.
Both astrocytes and neurons are involved in glycine removal. Astrocytic glycine uptake systems have been partially characterized in vitro and in vivo. The high-affinity glycine transporters that are involved in synaptic regulation have been cloned, and two separate genes appear to encode for these transporters. These proteins belong to the same transporter family as those for the biogenic amines, with transport function being both sodium- and chloride-dependent. The GlyT1 glycine transporter is expressed by astrocytes in the spinal cord, brainstem, and brain hemispheres. Isoforms resulting from mRNA splice variants have been described for both GlyT1 and GlyT2, although the physiological significance of these isoforms is not known. The GlyT2 uptake system is restricted to the spinal cord, brainstem and cerebellum, and is not found in the cortex and other regions of the brain hemispheres. Based on their distributions, it is believed that GlyT2 is involved in regulating glycine that acts at the strychnine-sensitive glycine receptors, whereas GlyT1 is likely involved in removing glycine from synapses containing NMDA receptors.
The selective inhibition of GlyT1 action would appear to be a rational approach to increasing the function of the NMDA receptor without the inherent side-effects associated with modulation of the glutamate binding site. Such an approach could provide useful therapeutic agents to treat, for example, schizophrenia, dementias, learning impairment and various neurodegenerative disorders. The inhibition of GlyT2 would lead to elevated levels of glycine near the strychnine-sensitive glycine receptors. The enhancement of activity at this receptor could prove beneficial in treating muscle spasticity resulting, for example, from spinal cord injury or multiple sclerosis. Furthermore, GlyT2 inhibitors might provide benefit in the management of chronic pain.
Known glycine transporter inhibitors include substituted amines (U.S. Pat. No. 6,103,743, WO99/34790, WO97/45115 and 45423) and piperazinyl derivatives (WO99/44596 and 45011). Pyrazoles and pyrazolines are classes of compounds that are of pharmaceutical value and have been described, for example, as treatments for inflammatory disorders (EP178035, EP127371). However, pyrazolidines have not been described as pharmaceutical agents. Furthermore, hydrazines are a known class of compounds that have exhibited biological activities. No hydrazines, however, have been reported to have glycine transporter activities. Substituted hydrazines of Formula I are novel compounds which inhibit glycine transporters.
BRIEF SUMMARY OF THE INVENTION
The invention is directed to novel compounds of Formula I as follows:
wherein R 1 and R 4 are each independently an aryl group; and
R 2 and R 3 are each independently selected from the group consisting of hydrogen, alkyl, alkenyl, alkynyl, alkoxy, alkenoxy, alkynoxy, aliphatic acyl, —C 1 –C 3 alkylamino, alkenylamino, alkynylamino, di(C 1 –C 3 alkyl)amino, —C(O)O—(C 1 –C 3 alkyl), —C(O)NH—(C 1 –C 3 alkyl), —CH═NOH, —C(O)N(C 1 –C 3 alkyl) 2 , haloalkyl, alkoxycarbonyl, alkoxyalkoxy, carboxaldehyde, carboxamide, cycloalkyl, cycloalkenyl, cycloalkynyl, aryl, aroyl, aryloxy, arylamino, biaryl, thioaryl, heterocyclyl, heterocycloyl, alkylaryl, aralkenyl, aralkyl, alkylheterocyclyl, heterocyclylalkyl, —SO 2 —(C 1 –C 3 alkyl), —SO 3 —(C 1 –C 3 alkyl), sulfonamido, carbamate, aryloxyalkyl, carboxyl, —C(O)NH(benzyl) and —(CH 2 ) t R 5 ;
wherein R 5 is selected from the group consisting of hydrogen, amino, hydroxy, alkoxy, aliphatic acyl, —CN, carboxyl, carboxamide, alkoxycarbonyl, —C(O)NHOH, —C(O)NHNH 2 and carboxaldehyde; and t is an integer of one to four;
wherein R 1 , R 2 , R 3 , R 4 and R 5 are unsubstituted or substituted with at least one electron donating or electron withdrawing group;
and wherein R 2 and R 3 taken together may form a ring;
and pharmaceutically acceptable salts thereof.
In preferred compounds of Formula I above, R 1 and R 4 may each be phenyl, R 3 may be hydrogen, alkyl, alkenyl, alkynyl, aliphatic acyl, haloalkyl or —(CH 2 ) t R 5 ; and R 2 may be hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl or aryl.
More specifically, the compounds of this invention may be described by Formula II below
wherein r and s are each independently an integer of one to five;
R 6 and R 7 at each occurrence are each independently selected from the group consisting of halogen, alkenyl, alkynyl, alkoxy, aliphatic acyl, —CF 3 , —NO 2 , —CN, —C(O)O—(C 1 –C 3 alkyl), —C(O)NH—(C 1 –C 3 alkyl), —CH═NOH, —PO 3 H 2 , —OPO 3 H 2 , —C(O)N(C 1 –C 3 alkyl) 2 , haloalkyl, carboxaldehyde, carboxamide, aryl, aroyl, biaryl, heterocyclyl, heterocycloyl, aralkenyl, aralkyl, heterocyclylalkyl, sulfonyl, —SO 2 —(C 1 –C 3 alkyl), —SO 3 —(C 1 –C 3 alkyl), sulfonamido, carbamate, aryloxyalkyl, carboxyl and —C(O)NH(benzyl); and
R 2 and R 3 are each independently selected from the group consisting of hydrogen, alkyl, alkenyl, alkynyl, alkoxy, alkenoxy, alkynoxy, aliphatic acyl, —C 1 –C 3 alkylamino, alkenylamino, alkynylamino, di(C 1 –C 3 alkyl)amino, —C(O)O—(C 1 –C 3 alkyl), —C(O)NH—(C 1 –C 3 alkyl), —CH═NOH, —C(O)N(C 1 –C 3 alkyl) 2 , haloalkyl, alkoxycarbonyl, alkoxyalkoxy, carboxaldehyde, carboxamide, cycloalkyl, cycloalkenyl, cycloalkynyl, aryl, aroyl, aryloxy, arylamino, biaryl, thioaryl, heterocyclyl, heterocycloyl, alkylaryl, aralkenyl, aralkyl, alkylheterocyclyl, heterocyclylalkyl, —SO 2 —(C 1 –C 3 alkyl), —SO 3 —(C 1 –C 3 alkyl), sulfonamido, carbamate, aryloxyalkyl, carboxyl, —C(O)NH(benzyl) and —(CH 2 ) t R 5 ;
wherein R 5 is selected from the group consisting of hydrogen, amino, hydroxy, alkoxy, aliphatic acyl, —CN, carboxyl, carboxamide, alkoxycarbonyl, —C(O)NHOH, —C(O)NHNH 2 and carboxaldehyde; and t is an integer of one to four;
wherein R 2 , R 3 , R 5 , R 6 and R 7 are unsubstituted or substituted with at least one electron donating or electron withdrawing group;
and wherein R 2 and R 3 taken together may form a ring;
and pharmaceutically acceptable salts thereof.
In preferred compounds of Formula II above, r may be an integer of one to three; s may be an integer of one or two; R 3 may be hydrogen, alkyl, alkenyl, alkynyl, aliphatic acyl, haloalkyl or —(CH 2 ) t R 5 ; R 2 may be hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl or aryl; and, R 6 and R 7 may each independently be halogen, alkenyl, alkynyl, aliphatic acyl, —CF 3 , —NO 2 , —CN, —C(O)O—(C 1 –C 3 alkyl), —C(O)NH—(C 1 –C 3 alkyl), alkoxy, —C(O)N(C 1 –C 3 alkyl) 2 , aryl, aroyl, —SO 2 —(C 1 –C 3 alkyl), —SO 3 —(C 1 –C 3 alky) or sulfonamido.
More specifically, the compounds of this invention may be described by Formula III below
wherein r is an integer of one to three;
s is an integer of one or two;
t is an integer of one to four;
R 6 and R 7 at each occurrence are each independently selected from the group consisting of halogen, alkenyl, alkynyl, aliphatic acyl, —CF 3 , —NO 2 , —CN, —C(O)O—(C 1 –C 3 alkyl), —C(O)NH—(C 1 –C 3 alkyl), alkoxy, —C(O)N(C 1 –C 3 alkyl) 2 , aryl, aroyl, sulfonyl, —SO 2 —(C 1 –C 3 alkyl), —SO 3 —(C 1 –C 3 alkyl) and sulfonamido; and
R 5 is selected from the group consisting of hydrogen, amino, hydroxy, alkoxy, aliphatic acyl, —CN, carboxyl, carboxamide, alkoxycarbonyl, —C(O)NHOH, —C(O)NHNH 2 and carboxaldehyde;
wherein R 5 , R 6 and R 7 are unsubstituted or substituted with at least one electron donating or electron withdrawing group; and pharmaceutically acceptable salts thereof.
In preferred compounds of Formula III above, r is three and s is one.
Presently preferred compounds include 3-(N′-(2,6-dinitro-4-trifluoromethylphenyl)-N-(3-methoxyphenyl)hydrazino)propionic acid, 3-(N′-(2,6-dinitro-4 trifluoromethylphenyl)-N-(3-methoxyphenyl)hydrazino)propiontrile, 3-(N′-(2,6-dinitro-4-trifluoromethylphenyl)-N-phenylhydrazirio)-N-hydroxypropionamide, 2-[N′-(2,6-Dinitro-4-trifluoromethylphenyl)-N-phenylhydrazino]-N-hydroxyacetamide and pharmaceutically acceptable salts thereof.
Useful derivatives of the compounds of Formulae I, II and III include esters, carbamates, aminals, amides, optical isomers and prorugs thereof.
The present invention also relates to a pharmaceutical composition comprising a compound of Formula I, in a pharmaceutically acceptable carrier.
The present invention also relates to a method for selectively inhibiting glycine transporters in a mammal comprising administering to said mammal a therapeutic amount of a compound of Formula I.
DETAILED DESCRIPTION OF THE INVENTION
Definitions of Terms
The term “alkyl” as used herein alone or in combination refers to C 1 –C 12 straight or branched, substituted or unsubstituted saturated chain radicals derived from saturated hydrocarbons by the removal of one hydrogen atom, unless the term alkyl is preceded by a C x –C y designation. Representative examples of alkyl groups include methyl, ethyl, n-propyl, iso-propyl, n-butyl, sec-butyl, iso-butyl, and tert-butyl, among others.
The term “alkenyl”, alone or in combination, refers to a substituted or unsubstituted straight-chain or substituted or unsubstituted branched-chain alkenyl radical containing from 2 to 10 carbon atoms. Examples of such radicals include, but are not limited to, ethenyl, E- and Z-pentenyl, decenyl and the like.
The term “alkynyl”, alone or in combination, refers to a substituted or unsubstituted straight or substituted or unsubstituted branched chain alkynyl radical containing from 2 to 10 carbon atoms. Examples of such radicals include, but are not limited to ethynyl, propynyl, propargyl, butynyl, hexynyl, decynyl and the like.
The term “lower” modifying “alkyl”, “alkenyl”, “alkynyl” or “alkoxy” refers to a C 1 –C 6 unit for a particular functionality. For example lower alkyl means C 1 –C 6 alkyl.
The term “alkylaryl” alone or in combination, refers to an aryl group substituted with at least one alkyl radical.
The term “aliphatic acyl” alone or in combination, refers to radicals of formula alkyl-C(O)—, alkenyl-C(O)— and alkynyl-C(O)— derived from an alkane-, alkene- or alkyncarboxylic acid, wherein the terms “alkyl”, “alkenyl” and “alkynyl” are as defined above. Examples of such aliphatic acyl radicals include, but are not limited to, acetyl, propionyl, butyryl, valeryl, 4-methylvaleryl, acryloyl, crotyl, propiolyl and methylpropiolyl, among others.
The term “cycloalkyl” as used herein refers to an aliphatic ring system having 3 to 10 carbon atoms and 1 to 3 rings, including, but not limited to cyclopropyl, cyclopentyl, cyclohexyl, norbornyl, and adamantyl among others. Cycloalkyl groups can be unsubstituted or substituted with one, two or three substituents independently selected from lower alkyl, haloalkyl, alkoxy, thioalkoxy, amino, alkylamino, dialkylamino, hydroxy, halo, mercapto, nitro, carboxaldehyde, carboxy, alkoxycarbonyl and carboxamide. “Cycloalkyl” includes cis or trans forms. Furthermore, the-substituents may either be in endo or exo positions in the bridged bicyclic systems.
The term “cycloalkenyl” as used herein alone or in combination refers to a cyclic carbocycle containing from 4 to 8 carbon atoms and one or more double bonds. Examples of such cycloalkenyl radicals include, but are not limited to, cyclopentenyl, cyclohexenyl, cyclopentadienyl and the like.
The term “cycloalkynyl” as used herein alone or in combination refers to a cyclic carbocycle containing from 4 to 8 carbon atoms and one or more triple bonds.
The term “cycloalkylalkyl” as used herein refers to a cycloalkyl group appended to a lower alkyl radical, including, but not limited to cyclohexylmethyl.
The term “halo” or “halogen” as used herein refers to I, Br, Cl or F.
The term “haloalkyl” as used herein refers to a lower alkyl radical, to which is appended at least one halogen substituent, for example chloromethyl, fluoroethyl, trifluoromethyl and pentafluoroethyl among others.
The term “alkoxy”, alone or in combination, refers to an alkyl ether radical, wherein the term “alkyl” is as defined above. Examples of suitable alkyl ether radicals include, but are not limited to, methoxy, ethoxy, n-propoxy, iso-propoxy, n-butoxy, iso-butoxy, sec-butoxy, tert-butoxy and the like.
The term “alkoxycarbonyl”, alone or in combination, refers to an alkoxy group as previously defined appended to the parent molecular moiety through a carbonyl group. Examples of alkoxycarbonyl groups include methoxycarbonyl, ethoxycarbonyl and isopropoxycarbonyl among others.
The term “alkenoxy”, alone or in combination, refers to a radical of formula alkenyl-O—, provided that the radical is not an enol ether, wherein the term “alkenyl” is as defined above. Examples of suitable alkenoxy radicals include, but are not limited to, allyloxy, E- and Z-3-methyl-2-propenoxy and the like.
The term “alkynoxy”, alone or in combination, refers to a radical of formula alkynyl-O—, provided that the radical is not an -ynol ether. Examples of suitable alkynoxy radicals include, but are not limited to, propargyloxy, 2-butynyloxy and the like.
The term “carboxyl” as used herein refers to a carboxylic acid radical, —C(O)OH.
The term “thioalkoxy”, refers to a thioether radical of formula alkyl-S—, wherein “alkyl” is as defined above.
The term “sulfonamido” as used herein refers to —SO 2 NH 2 .
The term “carboxaldehyde” as used herein refers to —C(O)R wherein R is hydrogen.
The term “carboxamide” as used herein refers to —C(O)NR a R b wherein R a and R b are each independently hydrogen, alkyl or any other suitable substituent.
The term “alkoxyalkoxy” as used herein refers to R c O—R d O— wherein R c is lower alkyl as defined above and R d is alkylene wherein alkylene is —(CH 2 ) n′ — wherein n′ is an integer from 1 to 6. Representative examples of alkoxyalkoxy groups include methoxymethoxy, ethoxymethoxy, t-butoxymethoxy among others.
The term “alkylamino” as used herein refers to R e NH— wherein R e is a lower alkyl group, for example, ethylamino, butylamino, among others.
The term “alkenylamino” alone or in combination, refers to a radical of formula alkenyl-NH— or (alkenyl) 2 N—, wherein the term “alkenyl” is as defined above, provided that the radical is not an enamine. An example of such alkenylamino radical is the allylamino radical.
The term “alkynylamino”, alone or in combination, refers to a radical of formula alkynyl-NH— or (alkynyl) 2 N— wherein the term “alkynyl” is as defined above, provided that the radical is not an amine. An example of such alkynylamino radicals is the propargyl amino radical.
The term “dialkylamino” as used herein refers to R f R g N— wherein R f and R g are independently selected from lower alkyl, for example diethylamino, and methyl propylamino, among others.
The term “amino” as used herein refers to H 2 N—.
The term “alkoxycarbonyl” as used herein refers to an alkoxyl group as previously defined appended to the parent molecular moiety through a carbonyl group. Examples of alkoxycarbonyl include methoxycarbonyl, ethoxycarbonyl, and isopropoxycarbonyl among others.
The term “aryl” or “aromatic” as used herein alone or in combination refers to a substituted or unsubstituted carbocyclic aromatic group having about 6 to 12 carbon atoms such as phenyl, naphthyl, indenyl, indanyl, azulenyl, fluorenyl and anthracenyl; or a heterocyclic aromatic group selected from the group consisting of furyl, thienyl, pyridyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, pyrazolyl, 2-pyrazolinyl, pyrazolidinyl, isoxazolyl, isothiazolyl, 1,2,3-oxadiazolyl, 1,2,3-triazolyl, 1,3,4-thiadiazolyl, pyridazinyl, pyrimidinyl, pyrazinyl, 1,3,5-triazinyl, 1,3,5-trithianyl, indolizinyl, indolyl, isoindolyl, 3H-indolyl, indolinyl, benzo[b]furanyl, 2,3-dihydrobenzofuranyl, benzo[b]thiophenyl, 1H-indazolyl, benzimidazolyl, benzthiazolyl, purinyl, 4H-quinolizinyl, isoquinolinyl, cinnolinyl, phthalazinyl, quinazolinyl, quinoxalinyl, 1,8-naphthridinyl, pteridinyl, carbazolyl, acridinyl, phenazinyl, phenothiazinyl, phenoxyazinyl, pyrazolo[1,5-c]triazinyl and the like. “Arylalkyl” and “alkylaryl” employ the term “alkyl” as defined above. Rings may be multiply substituted.
The term “aralkyl”, alone or in combination, refers to an aryl substituted alkyl radical, wherein the terms “alkyl” and “aryl” are as defined above. Examples of suitable aralkyl radicals include, but are not limited to, phenylmethyl, phenethyl, phenylhexyl, diphenylmethyl, pyridylmethyl, tetrazolyl methyl, furylmethyl, imidazolyl methyl, indolylmethyl, thienylpropyl and the like.
The term “aralkenyl”, alone or in combination, refers to an aryl substituted alkenyl radical, wherein the terms “aryl” and “alkenyl” are as defined above.
The term “arylamino”, alone or in combination, refers to a radical of formula aryl-NH—, wherein “aryl” is as defined above. Examples of arylamino radicals include, but are not limited to, phenylamino(anilido), naphthylamino, 2-, 3-, and 4-pyridylamino and the like.
The term “aryloxyalkyl” as used herein refers to an arylether radical attached to an alkyl group.
The term “biaryl”, alone or in combination, refers to a radical of formula aryl—aryl, wherein the term “aryl” is as defined above.
The term “thioaryl”, alone or in combination, refers to a radical of formula aryl-S—, wherein the term “aryl” is as defined above. An example of a thioaryl radical is the thiophenyl radical.
The term “aroyl”, alone or in combination, refers to a radical of formula aryl-CO—, wherein the term “aryl” is as defined above. Examples of suitable aromatic acyl radicals include, but are not limited to, benzoyl, 4-halobenzoyl, 4-carboxybenzoyl, naphthoyl, pyridylcarbonyl and the like.
The term “heterocyclyl”, alone or in combination, refers to a non-aromatic 3- to 10-membered ring containing at least one endocyclic N, O, or S atom. The heterocycle may be optionally aryl-fused. The heterocycle may also optionally be substituted with at least one substituent which is independently selected from the group consisting of hydrogen, halogen, hydroxyl, amino, nitro, trifluoromethyl, trifluoromethoxy, alkyl, aralkyl, alkenyl, alkynyl, aryl, cyano, carboxy, carboalkoxy, carboxyalkyl, oxo, arylsulfonyl and aralkylaminocarbonyl among others.
The term “alkylheterocyclyl” as used herein refers to an alkyl group as previously defined appended to the parent molecular moiety through a heterocyclyl group.
The term “heterocyclylalkyl” as used herein refers to a heterocyclyl group as previously defined appended to the parent molecular moiety through an alkyl group.
The term “heterocycloyl”, as used herein refers to radicals of formula heterocyclyl-C(O)—, wherein the term “heterocyclyl” is as defined above. Examples of suitable heterocycloyl radicals include tetrahydrofuranylcarbonyl, piperidinecarbonyl and tetrahydrothiophenecarbonyl among others.
The term “aminal” as used herein refers to a hemi-acetal of the structure RCH(NH 2 )(OH).
The term “amide” as used herein refers to a moiety ending with a —C(O)NH 2 functional group.
The term “ester” as used herein refers to —C(O)R m , wherein R m is hydrogen, alkyl or any other suitable substituent.
The term “carbamate” as used herein refers to compounds based on carbamic acid, NH 2 C(O)OH.
The term “optical isomers” as used herein refers to enantiomers which are optically active.
Use of the above terms is meant to encompass substituted and unsubstituted moieties. Substitution may be by one or more groups such as alcohols, ethers, esters, amides, sulfones, sulfides, hydroxyl, nitro, cyano, carboxy, amines, heteroatoms, lower alkyl, lower alkoxy, lower alkoxycarbonyl, alkoxyalkoxy, acyloxy, halogens, trifluoromethoxy, trifluoromethyl, alkyl, aralkyl, alkenyl, alkynyl, aryl, cyano, carboxy, carboalkoxy, carboxyalkyl, cycloalkyl, cycloalkylalkyl, heterocyclyl, alkytheterocyclyl, heterocyclylalkyl, oxo, arylsulfonyl and aralkylaminocarbonyl or any of the substituents of the preceding paragraphs or any of those substituents either attached directly or by suitable linkers. The linkers are typically short chains of 1–3 atoms containing any combination of —C—, —C(O)—, —NH—, —S—, —S(O)—, —O—, —C(O)O— or —S(O)O—. Rings may be substituted multiple times.
When R 2 and R 3 are taken together to form a ring, the ring formed may be heterocyclyl or aryl, as defined above. An example of such ring formation is found in compound 23 of Table 1.
The terms “electron-withdrawing” or “electron-donating” refer to the ability of a substituent to withdraw or donate electrons relative to that of hydrogen if hydrogen occupied the same position in the molecule. These terms are well-understood by one skilled in the art and are discussed in Advanced Organic Chemistry by J. March, 1985, pp. 16–18, incorporated herein by reference. Electron withdrawing groups include halo, nitro, carboxyl, lower alkenyl, lower alkynyl, carboxaldehyde, carboxyamido, aryl, quaternary ammonium, trifluoromethyl, and aryl lower alkanoyl among others. Electron donating groups include-such groups as hydroxy, lower-alkyl; amino, lower alkylamino, di(lower alkyl)amino, aryloxy, mercapto, lower alkylthio, lower alkylmercapto, and disulfide among others. One skilled in the art will appreciate that the aforesaid substituents may have electron donating or electron withdrawing properties under different chemical conditions. Moreover, the present invention contemplates any combination of substituents selected from the above-identified groups.
The most preferred electron donating or electron withdrawing substituents are halo, nitro, alkanoyl, carboxaldehyde, arylalkanoyl, aryloxy, carboxyl, carboxamide, cyano, sulfonyl, sulfoxide, heterocyclyl, guanidine, quaternary ammonium, lower alkenyl, lower alkynyl, sulfonium salts, hydroxy, lower alkoxy, lower alkyl, amino, lower alkylamino, di(lower alkyl)amino, amine lower alkyl mercapto, mercaptoalkyl, alkylthio and alkyldithio.
As used herein, the term “composition” is intended to encompass a product comprising the specified ingredients in the specified amounts, as well as any product which results, directly or indirectly, from a combination of the specified ingredients in the specified amounts.
Abbreviations
Abbreviations which have been used in the schemes and the examples which follow are: DEAD for diethylazodicarboxylate, EDCI for 1-(3-diethylaminopropyl)-3-ethylcarbodiimide, HOBt for 1-hydroxybenzotriazole hydrate, DMF for dirnethyl formamide, THF for tetrahydrofuran, and TLC for thin layer chromatography.
Examples of procedures that may be used to synthesize compounds of the formulae shown above are presented in the following Schemes.
The synthesis of the compounds of the invention is illustrated in Scheme I. An N-substituted pyrazolidinone (1) reacts with a substituted halobenzene in the presence of a base, such as n-butyl lithium or sodium hydride, in a solvent such as N,N-dimethyl formamide, N-methylpyrrolidinone, tetrahydrofuran or dimethyl sulfoxide, to afford the substituted pyrazolidinone 2, which is then treated with a nucleophile HX to form compounds of Formula I. For example, when compound 2 is treated with ammonia, the ring-opened carboxylic amide 3 of Formula I is formed, which can be further converted to the nitrile 4 of Formula I.
An alternative synthesis is depicted in Scheme II. An aminopyrazoline 6 reacts with a substituted halobenzene in the presence of a base, such as n-butyl lithium or sodium hydride, in a solvent such as N-methyl formamide, N-methyl pyrrolidinone, or dimethyl sulfoxide, to afford the nitrile 4 of Formula I.
The nitrile group in 4 may further be changed into other functional groups, such as carboxylic group via hydrolysis, amino group via reduction, or amidine group via amination.
The synthesis of analogs devoid of functionality of the aromatic rings is outlined in Scheme III above. The reaction of diphenyl hydrazine (8) with an acid chloride 9 such as ethyl succinyl chloride, provided the corresponding amide 10 in good yield. Removal of the amide was accomplished by a selective reduction in the presence of the ester using BH 3 .THF. Ester 11 was subsequently transformed into a variety of functional groups using standard procedures. As depicted in Scheme III, ester 11 was transformed into amide 12 via saponification followed by acid chloride formation and quenching with ammonia.
The synthesis of non-aromatic substituted hydrazines such as 19 is detailed in Scheme IV. The synthetic strategy is convergent and begins with the simple preparation of both fragments 15 and 17. The unification of ester 15 and hydrazine 17 can be mediated by trimethylaluminum, in accord with the Weinreb procedures, Tet. Let. No. 48, pp. 4171–4174, 1977. Selective reduction of amide 18 followed by saponification completed the synthesis.
A detailed description of the preparation of representative compounds of the present invention is set forth in the Examples.
The compounds of the present invention can be used in the form of pharmaceutically acceptable salts derived from inorganic or organic acids. The phrase “pharmaceutically acceptable salt” means those salts which are, within the scope of sound medical judgement, suitable for use in contact with the tissues of humans and lower animals without undue toxicity, irritation, allergic response and the like and are commensurate with a reasonable benefit/risk ratio. Pharmaceutically acceptable salts are well-known in the art. For example, S. M. Berge et al. describe pharmaceutically acceptable salts in detail in J. Pharmaceutical Sciences, 1977, 66: 1 et seq. The salts can be prepared in situ during the final isolation and purification of the compounds of the invention or separately by reacting a free base function with a suitable organic acid. Representative acid addition salts include, but are not limited to acetate, adipate, alginate, citrate, aspartate, benzoate, benzenesulfonate, bisulfate, butyrate, camphorate, camphor sulfonate, digluconate, glycerophosphate, hemisulfate, heptanoate, hexanoate, fumarate, hydrochloride, hydrobromide, hydroiodide, 2-hydroxyethansulfonate (isothionate), lactate, maleate, methane sulfonate, nicotinate, 2-naphthalene sulfonate, oxalate, palmitoate, pectinate, persulfate, 3-phenylpropionate, picrate, pivalate, propionate, succinate, tartrate, thiocyanate, phosphate, glutamate, bicarbonate, p-toluenesulfonate and undecanoate. Also, the basic nitrogen-containing groups can be quaternized with such agents as lower alkyl halides such as methyl, ethyl, propyl, and butyl chlorides, bromides and iodides; dialkyl sulfates like dimethyl, diethyl, dibutyl and diamyl sulfates; long chain halides such as decyl, lauryl, myristyl and stearyl chlorides, bromides and iodides; arylalkyl halides like benzyl and phenethyl bromides and others. Water or oil-soluble or dispersible products are thereby obtained. Examples of acids which can be employed to form pharmaceutically acceptable acid addition salts include such inorganic acids as hydrochloric acid, hydrobromic acid, sulphuric acid and phosphoric acid and such organic acids as oxalic acid, maleic acid, succinic acid and citric acid.
Basic addition salts can be prepared in situ during the final isolation and purification of compounds of this invention by reacting a carboxylic acid-containing moiety with a suitable, base such as the hydroxide, carbonate or bicarbonate of a pharmaceutically acceptable metal cation or with ammonia or an organic primary, secondary or tertiary amine. Pharmaceutically acceptable salts include, but are not limited to, cations based on alkali metals or alkaline earth metals such as lithium, sodium, potassium, calcium, magnesium and aluminum salts and the like and nontoxic quaternary ammonia and amine cations including ammonium, tetramethyl ammonium, tetraethylammonium, methylammonium, dimethylammonium, trimethylammonium, triethylammonium, diethylammonium, and ethylammonium among others. Other representative organic amines useful for the formation of base addition salts include ethylenediamine, ethanolamine, diethanolamine, piperidine, piperazine and the like.
Dosage forms for topical administration of a compound of this invention include powders, sprays, ointments and inhalants. The active compound is mixed under sterile conditions with a pharmaceutically acceptable carrier and any needed preservatives, buffers or propellants which can be required. Opthalmic formulations, eye ointments, powders and solutions are also contemplated as being within the scope of this invention.
Actual dosage levels of active ingredients in the pharmaceutical compositions of this invention can be varied so as to obtain an amount of the active compound(s) which is effective to achieve the desired therapeutic response for a particular patient, compositions and mode of administration. The selected dosage level will depend upon the activity of the particular compound, the route of administration, the severity of the condition being treated and the condition and prior medical history of the patient being treated. However, it is within the skill of the art to start doses of the compound at levels lower than required to achieve the desired therapeutic effect and to gradually increase the dosage until the desired effect is achieved.
When used in the above or other treatments, a therapeutically effective amount of one of the compounds of the present invention can be employed in pure form or, where such forms exist, in pharmaceutically acceptable salt, ester or prodrug form. Alternatively, the compound can be administered as a pharmaceutical composition containing the compound of interest in combination with one or more pharmaceutically acceptable excipients. The phrase “therapeutically effective amount” of the compound of the invention means a sufficient amount of the compound to treat disorders, at a reasonable benefit/risk ratio applicable to any medical treatment. It will be understood, however, that the total daily usage of the compounds and compositions of the present invention will be decided by the attending physician within the scope of sound medical judgement. The specific therapeutically effective dose level for any particular patient will depend upon a variety of factors including the disorder being treated and the severity of the disorder; activity of the specific compound employed; the specific composition employed; the age, body weight, general health, sex and diet of the patient; the time of administration, route of administration, and rate of excretion of the specific compound employed; the duration of the treatment; drugs used in combination or coincidental with the specific compound employed; and like factors well known in the medical arts. For example, it is well within the skill of the art to start doses of the compound at levels lower than required to achieve the desired therapeutic effect and to gradually increase the dosage until the desired effect is achieved.
The total daily dose of the compounds of this invention administered to a human or lower animal may range from about 0.0001 to about 1000 mg/kg/day. For purposes of oral administration, more preferable doses can be in the range from about 0.001 to about 5 mg/kg/day. If desired, the effective daily dose can be divided into multiple doses for purposes of administration; consequently, single dose compositions may contain such amounts or submultiples thereof to make up the daily dose.
The present invention also provides pharmaceutical compositions that comprise compounds of the present invention formulated together with one or more non-toxic pharmaceutically acceptable carriers. The pharmaceutical compositions can be specially formulated for oral administration in solid or liquid form, for parenteral injection or for rectal administration.
The pharmaceutical compositions of this invention can be administered to humans and other mammals orally, rectally, parenterally, intracisternally, intravaginally, intraperitoneally, topically (as by powders, ointments or drops), bucally or as an oral or nasal spray. The term “parenterally,” as used herein, refers to modes of administration which include intravenous, intramuscular, intraperitoneal, intrasternal, subcutaneous and intraarticular injection and infusion.
In another aspect, the present invention provides a pharmaceutical composition comprising a component of the present invention and a physiologically tolerable diluent. The present invention includes one or more compounds as described above formulated into compositions together with one or more non-toxic physiologically tolerable or acceptable diluents, carriers, adjuvants or vehicles that are collectively referred to herein as diluents, for parenteral injection, for intranasal delivery, for oral administration in solid or liquid form, for rectal or topical administration, or the like.
The compositions can also be delivered through a catheter for local delivery at a target site, via an intracoronary stent (a tubular device composed of a fine wire mesh), or via a biodegradable polymer. The compounds may also be complexed to ligands, such as antibodies, for targeted delivery. Compositions suitable for parenteral injection may comprise physiologically acceptable, sterile aqueous or nonaqueous solutions, dispersions, suspensions or emulsions and sterile powders for reconstitution into sterile injectable solutions or dispersions. Examples of suitable aqueous and nonaqueous carriers, diluents, solvents or vehicles include water, ethanol, polyols (propyleneglycol, polyethyleneglycol, glycerol, and the like), vegetable oils (such as olive oil), injectable organic esters such as ethyl oleate, and suitable mixtures thereof. These compositions can also contain adjuvants such as preserving, wetting, emulsifying, and dispensing agents. Prevention of the action of microorganisms can be ensured by various antibacterial and antifungal agents, for example, parabens, chlorobutanol, phenol, sorbic acid, and the like. It may also be desirable to include isotonic agents, for example sugars, sodium chloride and the like. Prolonged absorption of the injectable pharmaceutical form can be brought about by the use of agents delaying absorption, for example, aluminum monostearate and gelatin.
Suspensions, in addition to the active compounds, may contain suspending agents, as for example, ethoxylated isostearyl alcohols, polyoxyethylene sorbitol and sorbitan esters, microcrystalline cellulose, aluminum metahydroxide, bentonite, agar-agar and tragacanth, or mixtures of these substances, and the like.
Proper fluidity can be maintained, for example, by the use of coating materials such as lecithin, by the maintenance of the required particle size in the case of dispersions and by the use of surfactants.
In some cases, in order to prolong the effect of the drug, it is desirable to slow the absorption of the drug from subcutaneous or intramuscular injection. This can be accomplished by the use of a liquid suspension of crystalline or amorphous material with poor water solubility. The rate of absorption of the drug then depends upon its rate of dissolution which, in turn, may depend upon crystal size and crystalline form. Alternatively, delayed absorption of a parenterally administered drug form is accomplished by dissolving or suspending the drug in an oil vehicle.
Injectable depot forms are made by forming microencapsule matrices of the drug in biodegradable polymers such as polylactide-polyglycolide. Depending upon the ratio of drug to polymer and the nature of the particular polymer employed, the rate of drug release can be controlled. Examples of other biodegradable polymers include poly(orthoesters) and poly(anhydrides). Depot injectable formulations are also prepared by entrapping the drug in liposomes or microemulsions which are compatible with body tissues.
The injectable formulations can be sterilized, for example, by filtration through a bacterial-retaining filter or by incorporating sterilizing agents in the form of sterile solid compositions which can be dissolved or dispersed in sterile water or other sterile injectable medium just prior to use.
Solid dosage forms for oral administration include capsules, tablets, pills, powders and granules. In such solid dosage forms, the active compound may be mixed with at least one inert, pharmaceutically acceptable excipient or carrier, such as sodium citrate or dicalcium phosphate and/or a) fillers or extenders such as starches, lactose, sucrose, glucose, mannitol and silicic acid; b) binders such as carboxymethylcellulose, alginates, gelatin, polyvinylpyrrolidone, sucrose and acacia; c) humectants such as glycerol; d) disintegrating agents such as agar-agar, calcium carbonate, potato or tapioca starch, alginic acid, certain silicates and sodium carbonate; e) solution retarding agents such as paraffin; f) absorption accelerators such as quaternary ammonium compounds; g) wetting agents such as cetyl alcohol and glycerol monostearate; h) absorbents such as kaolin and bentonite clay and i) lubricants such as talc, calcium stearate, magnesium stearate, solid polyethylene glycols, sodium lauryl sulfate and mixtures thereof. In the case of capsules, tablets and pills, the dosage form may also comprise buffering agents.
Solid compositions of a similar type may also be employed as fillers in soft and hard-filled gelatin capsules using such excipients as lactose or milk sugar as well as high molecular weight polyethylene glycols and the like. The solid dosage forms of tablets, dragees, capsules, pills and granules can be prepared with coatings and shells such as enteric coatings and other coatings well-known in the pharmaceutical formulating art. They may optionally contain opacifying agents and may also be of a composition such that they release the active ingredient(s) only, or preferentially, in a certain part of the intestinal tract, optionally, in a delayed manner. Examples of embedding compositions which can be used include polymeric substances and waxes.
The active compounds can also be in micro-encapsulated form, if appropriate, with one or more of the above-mentioned excipients.
Liquid dosage forms for oral administration include pharmaceutically acceptable emulsions, solutions, suspensions, syrups and elixirs. In addition to the active compounds, the liquid dosage forms may contain inert diluents commonly used in the art such as, for example, water or other solvents, solubilizing agents and emulsifiers such as ethyl alcohol, isopropyl alcohol, ethyl carbonate, ethyl acetate, benzyl alcohol, benzyl benzoate, propylene glycol, 1,3-butylene glycol, dimethyl formamide, oils (in particular, cottonseed, groundnut, corn, germ, olive, castor and sesame oils), glycerol, tetrahydrofurfiryl alcohol, polyethylene glycols and fatty acid esters of sorbitan and mixtures thereof. Besides inert diluents, the oral compositions may also include adjuvants such as wetting agents, emulsifying and suspending agents, sweetening, flavoring and perfuming agents.
Compositions for rectal or vaginal administration are preferably suppositories which can be prepared by mixing the compounds of this invention with suitable non-irritating excipients or carriers such as cocoa butter, polyethylene glycol or a suppository wax which are solid at room temperature but liquid at body temperature and therefore melt in the rectum or vaginal cavity and release the active compound.
Compounds of the present invention can also be administered in the form of liposomes. As is known in the art, liposomes are generally derived from phospholipids or other lipid substances. Liposomes are formed by mono- or multi-lamellar hydrated liquid crystals which are dispersed in an aqueous medium. Any non-toxic, physiologically acceptable and metabolizable lipid capable of forming liposomes can be used. The present compositions in liposome form can contain, in addition to a compound of the present invention, stabilizers, preservatives, excipients and the like. The preferred lipids are natural and synthetic phospholipids and phosphatidyl cholines (lecithins) used separately or together.
Methods to form liposomes are known in the art. See, for example, Prescott, Ed., Methods in Cell Biology , Volume XIV, Academic Press, New York, N.Y. (1976), p. 33 et seq.
The term “pharmaceutically acceptable prodrugs” as used herein represents those prodrugs of the compounds of the present invention which are, within the scope of sound medical judgement, suitable for use in contact with the tissues of humans and lower animals without undue toxicity, irritation, allergic response, and the like, commensurate with a reasonable benefit/risk ratio, and effective for their intended use, as well as the zwitterionic forms, where possible, of the compounds of the invention. Prodrugs of the present invention may be rapidly transformed in vivo to the parent compound of the above formula, for example, by hydrolysis in blood. A thorough discussion is provided in T. Higuchi and V. Stella, Pro - drugs as Novel Delivery Systems , V. 14 of the A.C.S. Symposium Series, and in Edward B. Roche, ed., Bioreversible Carriers in Drug Design , American Pharmaceutical Association and Pergamon Press (1987), hereby incorporated by reference.
The present invention contemplates both synthetic compounds of Formulae I, II and III of the present invention, as well as compounds formed by in vivo conversion to compounds of the present invention.
Compounds of the present invention may exist as stereoisomers wherein asymmetric or chiral centers are present. These stereoisomers are “R” or “S” depending on the configuration of substituents around the chiral carbon atom. The present invention contemplates various stereoisomers and mixtures thereof. Stereoisomers include enantiomers and diastereomers, and mixtures of enantiomers or diastereomers. Individual stereoisomers of compounds of the present invention may be prepared synthetically from commercially available starting materials which contain asymmetric or chiral centers or by preparation of racemic mixtures followed by resolution well-known to those of ordinary skill in the art. These methods of resolution are exemplified by (1) attachment of a mixture of enantiomers to a chiral auxiliary, separation of the resulting mixture of diastereomers by recrystallization or chromatography and liberation of the optically pure product from the auxiliary or (2) direct separation of the mixture of optical enantiomers on chiral chromatographic columns.
The compounds of the invention can exist in unsolvated as well as solvated forms, including hydrated forms, such as hemi-hydrates. In general, the solvated forms, with pharmaceutically acceptable solvents such as water and ethanol among others are equivalent to the unsolvated forms for the purposes of the invention.
The ability of compounds of the present invention to inhibit GlyT1 activity is described in detail hereinafter in the Examples. These Examples are presented to describe preferred embodiments and utilities of the invention and are not meant to limit the invention unless otherwise stated in the claims appended hereto.
EXAMPLE 1
2-(2,6-Dinitro-4-trifluoromethylphenyl)-1-phenylpyrazolidin-3-one (Compound 2 in Table 1) was synthesized according to the following procedure, illustrated by general Scheme I.
1-Phenylpyrazolidin-3-one (1.01 g, 6.23 mmol) was added to a suspension of NaH (6%, 278 mg, 6.95 mmol, 1.1 eq.(equivalents)) in DMF (31 mL) under a blanket of N 2 at ambient temperature. After 30 minutes, 4-chloro-3,5-dinitrobenzotrifluoride (2.00 g, 7.39 mmol, 1.2 eq.) was added to the red solution. The reaction mixture was maintained for 12 hours and was then poured onto H 2 O (120 mL) and extracted with Et 2 O/CH 2 Cl 2 [(2/1) 3×50 mL]. The combined organic layers were dried (Na 2 SO 4 ) and concentrated in vacuo. The residue was purified by chromatography (hexanes/EtOAc, 4/1) to provide the title product (2.21 g, 89%) as a yellow-orange foam.
EXAMPLE 2
3-[N′-(2,6-Dinitro-4-trifluoromethylphenyl)-N-phenylhydrazino]propionamide (Compound 3 of Table 1) was synthesized according to the following synthetic procedure, illustrated by general Scheme I.
Concentrated ammonium hydroxide (3.5 mL) was added to a solution of 2-(2,6-Dinitro-4-trifluoromethylphenyl)-1-phenylpyrazolidin-3-one (502 mg, 1.27 mmol) in THF (8 mL). The reaction mixture darkened to a deep brown within 20 seconds. After 10 minutes, brine (20 nL) was added and the mixture extracted with CH 2 Cl 2 (3×10 mL). The combined organic layers were dried (Na 2 SO 4 ) and concentrated in vacuo. The residue was purified by chromatography [hexanes/EtOAc, 2/1 (300 mL) then 1/4] to give the title product as a red foam (493 mg, 94%).
EXAMPLE 3
3-[N′-(2,6-Dinitro-4-trifluoromethylphenyl)-N-phenylhydrazino]propionitrile (Compound 4 of Table 1) was synthesized according to the following procedure, illustrated by general Scheme I.
A solution of 3-[N′-(2,6-Dinitro-4-trifluoromethylphenyl)-N-phenylhydrazino]pionamide (79 mg, 0.19 mmol) in dry benzene (3 mL) was treated with dry dimethylformamide (0.1 mL, 1.29 mmol, 6.8 eq.) and thionyl chloride (0.17 mL, 2.3 mmol, 12 eq.) at room temperature. The mixture was stirred for 15 minutes and then slowly diluted with water and extracted with ether. The organic layer was dried (Na 2 SO 4 ) and concentrated in vacuo to provide the crude title product (80 mg). A pure sample of the title product was obtained as yellow needles by purification by preparative TLC (hexane/EtOAc, 2/1) followed by recrystallization from hexanes.
EXAMPLE 4
3-[N′-(2,6-Dinitro-4-trifluoromethylphenyl)-N-phenylhydrazino]propionitrile (Compound 4 of Table 1) was alternatively synthesized according to the following procedure, illustrated by general Scheme II.
A solution of the aminopyrazoline 6 (1.24 mmol) in dry N,N-dimethylformamide (3 mL) was treated with sodium hydride (50 mg, 1.24 mmol) at 0° C. The mixture was stirred at 0° C. for 1 hour followed by the addition of a solution of the substituted chlorobenzene (1.36 mmol) in N,N-dimethylformamide (2 mL). The reaction mixture was stirred at room temperature for 4 hours and treated with water. The resulting mixture was extracted with ethyl acetate, and the organic layer was separated, washed with water and dried over anhydrous Na 2 SO 4 to afford a crude product, which was purified by flash column chromatography to provide the final product 4 of Formula 1.
EXAMPLE 5
3-(N,N′-Diphenylhydrazinocarbonyl)propionic acid ethyl ester (Compound 10 of Table 1) was synthesized according to the following procedure, illustrated in Scheme III.
A solution of diphenyl hydrazine (1.01 g, 5.48 mmol) and triethylamine (0.80 mL, 5.7 mmol, 1 equivalent) in dry methylene chloride (9 mL) was treated dropwise with ethyl succinyl chloride (0.85 mL, 6.0 mmol, 1.1 equivalents) at 0° C. The reaction mixture was allowed to warm to room temperature after five minutes, and then was maintained at that temperature for three hours. The contents of the reaction vessel were then poured into water and the resultant layers were separated. The organic layer was washed (saturated NaHCO 3 and brine), dried over magnesium sulfate and concentrated. The residue was purified by chromatography (4:1 hexane/ethyl acetate) to provide the product (1.45 g, 85% as an oil.
EXAMPLE 6
4-(N,N′-Diphenylhydrazino)butyric acid ethyl ester (Compound 11 of Table 1) was synthesized according to the following procedure, illustrated in Scheme III.
Borane.tetrahydrofuran complex (1.0 M, 0.64 mmol, 2 equivalents) was added dropwise to a 0° C. solution of amide 10 (108 mg, 0.346 mmol) in tetrahydrofuran. After 1.5 hours, the reaction was quenched with methanol (0.8 mL) and concentrated. The residue was purified by PTLC (4:1 hexane:ethyl acetate) to provide the title compound (81.3 mg, 79%) as an oil.
Compounds of Formula I that were synthesized according to the general synthetic procedures are summarized in Table I. The last column in the Table indicates which synthetic scheme the compound was prepared in accordance with. Ph used in the structures in the Table stands for phenyl.
TABLE I
No.
Structure
Name
1 H NMR
2
2-(2,6-dinitro-4-trifluoromethylphenyl)-1-phenylpyrazolidin-3-one
8.10(s, 2H), 7.33–7.28(m, 4H), 7.16–7.12(bm, 1H), 2.90(t, J=7.2, 2H), 2.85(t, J=7.5, 2H)
I
3
3-(N′-(2,6-dinitro-4-trifluoromethylphenyl)-N-phenylhydrazino)propionamide
10.44(s, 1H), 8.57(bs, 1H), 7.69(bs,1H), 7.29(t, 3=7.5, 2H), 7.00(t,J=7.5, 1H), 6.87(d, 5=7.5, 2H), 5.51(bs, 1H), 5.36(bs,1H), 3.86–3.79(m,1H), 3.63(m, 1H),2.68–2.57(m, 1H),2.42–2.35(m, 1H)
I
4
3-(N′-(2,6-dinitro-4-trifluoromethylphenyl)-N-phenylhydrazino)propionitrile
9.82(s, 1H), 8.00(bs, 2H), 7.34(t, J=7.5, 2H), 7.10(t,J=7.5), 6.92(d,J=7.8, 2H), 3.77(bm, 1H), 3.65(bm,1H), 2.59(bm, 2H)
I,II
10
3-(N,N′-Diphenylhydrazinocarbonyl)propionicacid ethyl ester
7.48(m, 2H), 7.30(m, 2H), 7.22(m,3H), 6.85(m, 3H),4.13(q, 2H, 3=6.9),2.89(br m, 2H),2.66(t, 2H, J=6.0), 1.24(t, 3H,J=7.2)
III
20
3-(N′-(2,6-Dinitro-4-trifluoromethylphenyl)-N-(3-methoxyphenyl)hydrazino)propionitrile
9.80(s, 1H), 7.24(t, J=7.5, 1H),6.62(d, J=6, 1H),6.48(d, J=6.3,1H), 6.44(s, 1H),3.76(s and bm, 4H),3.63(bm, 1H), 2.59(bm, 1H)
I,II
21
3-(N′-(2-Nitro-4-trifluoromethylphenyl-N-phenylhydrazino)propionitrile
9.28(s, 1H), 8.50(s, 1H), 7.66(d, J=7.2, 1H), 7.55(s,1H), 7.53(m, J=9,1H), 7.32(t, J=8.7,2H), 7.02(t, J=7.5,1H), 6.96(d, J=7.8,2H), 3.91(bm, 1H),3.80(bm, 1H), 2.70(bm, 2H)
I,II
22
2-(3,5-Dinitropyridin-2-yl)-1-phenylpyrazolidin-3-one
9.37(d, 1H, J=2.1),8.97(d, 1H, J=2.4),7.31(t, 2H, J=8.4),7.23(d, 1H, J=7.5),7.09(t, 2H, J=7.2),4.13(t, 2H, J=7.5),2.85(t, 2H, J=7.5)
I
23
2-(2,6-Dinitro-4-trifluoromethylphenyl)-1-(3-methoxyphenyl)pyrazolidin-3-one
8.10(s, 2H), 7.21(t, 1H, J=8.1), 6.99(t, 2H, J=2.4), 6.83(dd, 1H, J=7.8,1.8), 6.66(dd, 1H,J=8.4, 2.4), 3.90(t,2H, J=7.8), 3.75 (s,3H), 2.84 (t, 2H,J=7.5)
I
24
3-N′-(2,6-Dinitro-4-trifluoromethylphenyl)-N-(3-hydrazino)propionamide
10.51(s, 1H), 8.55(br s, 1H), 7.69(brs, 1H), 7.18(t, 1H,J=8.4), 6.53(dd,1H, J=8.4, 2.1),6.42(m, 3H), 5.52(br s, 1H), 3.79(m,1H), 3.64(s, 3H),3.51(m, 1H), 2.67(m, 1H), 2.36(m,1H)
I
25
3-(N′-(2,6-Dinitro-4-trifluoromethylphenyl)-N-phenylhydrazino)propionic acidhydrazide
10.2(s, 1H), 8.56(br s, 1H), 7.71(brs, 1H), 7.27(t, 1H,J=8.4), 6.99(t, 1H,J=7.5), 6.87(d, 2H,J=7.2), 3.84(m,1H), 3.57(m, 1H),2.50(m, 1H), 2.28(m, 1H)
I
26
3-(N-(2,6-Dinitro-4-trifluoromethylphenyl)-N-phenylhydrazino)-N-hydroxypropionamide
10.27(s, 1H), 9.04(br s, 1H), 8.49(brs, 1H), 7.67(br s,1H), 7.22(t, 2H,J=7.5), 6.94(t, 1H,J=7.2), 6.81(d, 2H,J=7.5), 3.81(m,1H), 3.43(m, 1H),2.49(m, 1H), 2.26(m, 1H)
I
27
3-(N′-(2-Nitro-4-trifluoromethylphenyl)-N-phenylhydrazino)propionamide
9.53(s, 1H), 8.47(s, 1H), 7.58(d, 1H,J=7.2), 7.36(d, 1H,J=9), 7.27(t, 2H,J=8.1), 6.93(m,3H), 5.80(br s,1H), 5.43(br s,1H), 3.91(t, 2H,J=6.3), 2.64(br m,1H), 2.53(br m,1H)
I
28
3-(N-(3-Methoxyphenyl)-N′-(2-Nitro-4-trifluoromethylphenyl)-N-phenylhydrazino)propionamide
9.56(s, 1H), 8.46(s, 1H), 7.57(d, 1H,J=7.2), 7.33(d, 1H,J=9.0), 7.19(t, 1H,J=9.6), 6.48(m,3H), 5.84(br s,1H), 5.47(br s,1H), 3.90(m, 2H),2.65(m, 1H), 2.52(m, 1H)
I
29
2-(2-Nitro-4-trifluoromethylphenyl)-1-phenylpyrazolidin-3-one
8.07(s, 1H), 7.81(d, 1H, J=8.7), 7.74(d, 1H, J=7.2), 7.30(t, 2H, J=7.2), 7.22(d, 2H, J=7.8), 7.07(t, 1H, J=7.2), 4.06(t, 2H, J=7.5), 2.78(t, 2H, J=7.5)
I
30
2-(Bis-(4-fluorophenyl)methyl)-1-phenylpyrazolidin-3-one
7.34(m, 4H), 7.02(m, 6H), 6.88(t,1H, J=0.9), 6.80(d,2H, J=7.2), 6.33(s,1H), 3.85(t, 2H,J=7.5), 2.47(t, 2H,J=7.5)
I
31
3-(N′-(2,6-Dinitro-4-trifluoromethylphenyl)-N-phenylhydrazino)propionicacid
10.02(s, 1H), 8.57(br s, 1H), 7.73(brs, 1H), 7.31(t, 2H,J=7.5), 7.03(t, 1H,J=7.5), 6.87(d, 2H,J=8.1), 3.82(m,1H), 3.59(m, 1H),2.71(m, 1H), 2.57(m, 1H)
I
32
3-(N′-(2,6-Dinitro-4-trifluoromethylphenyl)-N-phenylhydrazino)propionicacid methyl ester
9.94(s, 1H), 8.54(br s, 1H), 7.68(brs, 1H), 7.29(t, 2H,J=8.1), 7.02(t, 1H,J=7.5), 6.88(d, 2H,J=7.8), 3.81(m,1H), 3.62(s, 3H),3.58(m, 1H), 2.65(m, 1H), 2.51(m,1H)
I
33
3-(N′-(2,6-Dinitro-4-trifluoromethylphenyl)-N-phenylhydrazino)thiopropionamide
9.66,(s, 1H), 8.57(br s, 1H), 7.75(brs, 1H), 7.44(br s,1H), 7.31(t, 2H,J=8.4), 7.05(t, 1H,J=7.5), 6.95(d, 2H,J=7.8), 6.85(br s,1H), 3.96(br m,1H), 3.86(br m,1H), 2.86(br m,1H), 2.79(br m,1H)
I
34
3-(N′-(2,6-Dinitro-4-trifluoromethylphenyl)-N-(3-methoxyphenyl)hydrazino)-N-hydroxypropionamide
10.29(br s, 1H),8.49(br s, 1H), 7.68(br s, 1H), 7.14(t,1H, J=8.1), 6.48(d,1H, J=8.4), 6.38(d,1H), 6.36(s, 1H),3.77(m, 1H), 3.70(s, 3H), 3.46(m,1H), 2.53(m, 1H),2.27(m, 1H)
I
35
3-(N′-(2,6-Dinitro-4-trifluoromethylphenyl)-N-phenylhydrazino)propan-1-ol
10.29(br s, 1H),8.58(br s, 1H), 7.70(br s, 1H), 7.29(d,2H, J=7.5), 6.98(t,1H, J=7.2), 6.86(d,2H, J=7.8), 3.75(m, 4H), 3.26(m,2H), 1.89(m, 1H)
I
36
3-(N′-(2,6-Dinitro-4-trifluoromethylphenyl)-N-phenyldiethylpropionamide
10.52(br s, 1H),8.56(br s, 1H), 7.68(br s, 1H), 7.26(t,2H, J=7.5), 6.97(t,1H, J=7.5), 6.87(d,2H, J=8.4), 3.84(m, 1H), 3.63(m,1H), 3.29(q, 2H,J=7.2), 3.12(q, 2H,J=7.2), 2.65(m,1H), 2.45(m, 1H),1.03 (t 3H, J=7.2),0.92 (t, 3H, J=7.2)
I
37
(N,N′-Diphenylhydrazinocarbonyl)acetic acidmethyl ester
7.54(d, 2H, J=8.1), 7.34(t, 1H,J=7.8), 7.26(t, 4H,J=8.4), 6.93(t,1H, J=7.5), 6.82(d,2H, J=7.8), 6.72(s,1H), 3.74(s, 5H)
III
39
(N′-(2,6-Dinitro-4-trifluoromethylphenyl)-N-phenylhydrazino)acetic acid ethylester
10.46(s, 1H), 8.66(br s, 1H), 7.79(brs, 1H), 7.32(t, 2H,J=8.4), 7.07(t, 1H,J=7.5), 6.92(d, 2H,J=8.7), 4.37(d, 1H,J=18), 4.21(q, 2H,J=6.9), 4.04(d, 1H,J=18), 1.27(t, 3H,J=6.9)
I
40
2-(N′-(2,6-Dinitro-4-trifluoromethylphenyl)-N-phenylhydrazino)-N-hydroxyacetamide
10.63(s, 1H), 9.10(br s, 1H), 8.59(brs, 1H), 7.77(br s,1H), 7.23(m, 2H),6.91(m, 3H), 4.13(q, 3H, J=7.2), 3.91(d, 1H, J=7.2), 3.91(d, 1H, J=16.8),1.27(t, 3H, 3=7.2)
I
41
(N′-(2,6-Dinitro-4-trifluoromethylphenyl)-N-methylhydrazino)acetic acid methylester
10.07(s, 1H), 8.57(br s, 1H), 7.83(brs, 1H), 4.29(q, 2H,J=6.9), 3.73(d, 1H,J=18), 3.42(d, 1H,J=18), 2.75(s, 3H),1.35(t, 3H, J=6.9)
I
42
3-(N′-(2,6-Dinitro-4-trifluoromethylphenyl)-N-(3-methoxyphenyl)hydrazino)propionicacid
10.02(s, 1H), 8.56(br s, 1H), 7.72(brs, 1H), 7.20(t, 1H,J=8.1), 6.55(d, 1H,J=8.1), 6.44(d, 1H,J=8.1), 6.40(s,1H), 5.28(s, 1H),3.80(m, 1H), 3.75(s, 3H), 3.30(m,1H), 2.75(m, 1H),2.58(m, 1H)
I
43
4-(N,N′-Diphenylhydrazinocarbonyl)butyricacid methyl ester
7.47(m, 2H), 7.33(m, 2H), 7.23(m,2H), 6.89(t, 2H, J=6.6), 6.81((m,2H), 6.60(br s,1H), 3.63(s, 3H),2.66(br m, 2H),2.40(m, 2H), 2.02(m, 2H)
III
44
(N,N′-Diphenylhydrazino)oxoacetic acidmethyl ester
7.54(d, 2H, J=8.1),7.35(t, 2H, J=7.2),7.24(m, 3H), 6.92(m, 3H), 6.62(s,1H), 3.77(s, 3H)
III
46
2-Fluorobenzoicacid N-phenylhydrazide
7.21(m, 6H), 6.89(m, 2H), 4.85(br s,2H)
III
51
2-Fluorabenzoicacid N′-(2,6-dinitro-4-trifluoromethylphenyl)-N-phenylhydrazide
10.38(br s, 1H),8.28(s, 2H), 7.48(m, 2H), 7.37(m,2H), 7.25(m, 2H),7.13(t, 2H, J=7.5),6.94(t, 1H, J=9.0)
I
EXAMPLE 5
The ability of compounds to inhibit GlyT1 activity was determined in an assay that utilizes human U373MG astrocytoma cells. The cells were seeded into 96-well plates at 1×10 4 cells per well in 0.1 ml of culture medium, and were allowed to grow for an additional two days to come to confluence. Prior to the start of transport studies, the cells were washed thoroughly with Kreb's-Ringer phosphate buffer containing 140 mM NaCl, 5 mM KCl and 0.75 mM CaCl 2 . One set of triplicate wells was washed with chloride-free buffer to serve as a measure of low affinity glycine transport, since high-affinity uptake requires Cl − . Test compounds (10 μM) dissolved in fresh buffer, as well as buffer-only controls, were added to the assay plate (50 μl/well). Uptake analyses were initiated by the addition of buffer containing [ 3 H]glycine (0.5 μCi/well), with a final glycine concentration of 100 nM. Glycine uptake was terminated after an 8 minute period by removing the medium and washing the cells with buffer. The cells in each well were subsequently solubilized in detergent to allow scintillation counting of the internalized [ 3 H]glycine. Untreated cells were lysed prior to initiation of the assay for protein determinations, using the BCA assay (Pierce Chemical Company, Rockford, Ill.). Glycine uptake is expressed as mnoles glycine/mg protein/min.
When the compounds of Table 1 are tested according to the above procedure, they are shown to inhibit high-affinity glycine uptake by the astrocytoma cells.
All references cited are hereby incorporated by reference.
The present invention is illustrated by way of the foregoing description and examples. The foregoing description is intended as a non-limiting illustration, since many variations will become apparent to those skilled in the art in view thereof. It is intended that all such variations within the scope and spirit of the appended claims be embraced thereby.
Changes can be made in the composition, operation and arrangement of the method of the present invention described herein without departing from nte concept and scope of the invention as defined in the following claims: | A method for the inhibition of high affinity glycine transporters, compounds that inhibit these transporters; pharmaceutically active compositions comprising such compounds; and the use of such compounds either as above, or in formulations for the control or prevention of disease states in which glycine is involved are disclosed. | 2 |
BACKGROUND OF THE INVENTION
The invention relates to improvements in paper machine press rolls, and more particularly to an improved press roll with a drilled hole pattern in the surface that attains improved dewatering of a web passing through a press couple formed between two press rolls.
The invention relates to a press roll primarily as used in a press couple where opposed parallel rolls pass a felt and a web therebetween to press water from the web into the felt. The roll backing the felt may be provided with various configurations to relieve the resistance to water flow and accept water being pressed into and through the felt. If no such means are provided, the roll is generally referred to as a plain roll, but the rolls with relieving openings are grooved rolls, blind drilled rolls, fabric sleeve rolls and suction rolls. While such rolls are presently currently used in roll couples, they may also be employed in extended nip presses where one side of the nip is faced by an arcuate shoe or belt creating a pressing zone against the surface of the roll.
A requirement of a roll in a dewatering press is that it function to transfer the maximum amount of water from a web to a felt passing through the nip, and this is accomplished by offering a minimum amount of resistance to the transfer of water. This must be done uniformly so as not to mark the web, and must be done with a minimum amount of rewetting on the offrunning side of the nip.
THE INVENTION
An object of the invention is to provide an improved press roll structure and particularly an open roll which enhances the removal of water from a web in the press nip, and which eliminates or substantially reduces the marking of the web.
Where an open roll is used with grooves or drilled holes in the surface, it has been thought by some that the water flow path length is of primary importance in determining water removal. This has been found to be a factor, but an important factor has been discovered to be the uniformity of pressure in the press nip. Such uniformity will not be accomplished if the drilled holes in the roll are too large so that the bridging distance over the holes permits the felt to be depressed into the hole thereby reducing the pressure applied to the web. Tests have shown that with low ingoing felt moisture, the plain press, the fabric sleeve press and the grooved press all perform about the same level. The blind drilled roll and suction roll do not give as good a performance, and this is believed to be due to a poorer pressure uniformity due to the large size of holes or vents in rolls with conventional structures, that is, with conventional size holes or vents and with a conventional distribution of holes or vents. While it is important to keep the flow path length short, it is equally important to keep the bridging distance short, that is, the distance across the hole opening.
It is generally not practical to drill a hole 2" to 3" deep which is necessary through a roll shell when the hole diameter is below 0.1". No practical manufacturing technique has been discovered for drilling deep small diameter holes so that it would be impractical to reduce the hole size in a suction roll in order to place the holes closer together to attain sufficient open area.
A feature of the invention is to provide a roll shell with holes of a conventional size extending all the way through the shell in a conventional suction roll manner, and to intersperse between the suction holes blind drilled holes. A further feature of the invention is to provide the blind drilled holes of varying depths, particularly in rubber covered rolls to avoid shear planes in the rubber cover. A further object of the invention is to provide a hole pattern as above described which reduces the noise generation occurring at high operating speeds.
A further object of the invention is to provide a press roll with holes or openings in the surface which are sufficiently small to reduce the bridging distance and obtain uniform pressure on the web and yet which are not so small that they will encounter plugging or filling from the material of the felt.
Other objects and advantages and features will become more apparent with the teaching of the principles of the invention in connection with the disclosure of the preferred embodiments in the specification, claims and drawings, in which:
DRAWINGS
FIG. 1 is a somewhat schematic elevational view of a roll press couple for dewatering a web in a paper machine;
FIG. 2 is an enlarged sectional view illustrating the effect of an opening in the roll shell on the felt;
FIG. 3 is a view similar to FIG. 2 illustrating a smaller opening in the roll shell;
FIG. 4 is a plan view of a portion of a roll shell surface constructed in accordance with the principles of the present invention; and
FIG. 5 is a fragmentary sectional view taken substantially along line V--V of FIG. 4.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates a roll couple with a wet paper web W supported on a felt F passing through the nip N. The nip is formed between an upper plain roll 10 suitably supported for rotation on an axis 14, and a lower roll shell 11 suitably supported for rotation on an axis 12. Within the roll shell and opposite the nip N is a suction gland 13.
As the web W is carried through the nip, it is subjected to the pressure between the two rolls and water is expressed out of the web into the felt and into openings in the surface of the roll shell 11. The openings are to permit water to pass easily into the felt from the paper and to receive water from the felt. In considerations of having larger open areas for the passage of water and for reducing the distance the water must travel, it has been discovered that reduced water transfer occurs with increased size of openings, and as illustrated in FIG. 2, at the bridging area of an opening 15, the felt F is unsupported. As illustrated at 17, where the opening in the suction roll has a dimension D, the felt tends to sag downwardly into the opening so that it is unsupported resulting in a low pressure area 18 opposite the web W. At this low pressure area, less water is pressed from the web so that despite a larger open area, not as much water travels out of the web into the felt and into the opening.
With a shorter bridging area 19 as illustrated in FIG. 3, as results from a smaller opening 16 in the roll 11, there is no low pressure area because the diameter of the opening 16 is small enough that the felt does not sag into the opening. This results in uniform pressure being applied to the web W even opposite the openings. Yet, as discussed above, it is impossible by known rechniques to drill small openings of sufficient number through the approximate 3" thickness of the roll shell.
In accordance with the concepts of the present invention, blind drilled holes are interspersed between the suction roll holes. As illustrated in FIGS. 4 and 5, holes 20 extend all the way through the roll shell. Between these are blind drilled holes 21 and 22 which can be of smaller diameter because they are not drilled all the way through the shell. Structurally, the blind drilled holes preferably extend only into the hard rubber cover 23 that forms the outer layer of the suction roll shell 11.
To avoid a shear plane being formed in the cover, the blind drilled holes 21 and 22 are drilled of different depths. From a structure standpoint, the roll shell has a plurality of holes in the surface leading to axially extending passages which are of different lengths. The passages formed at 20 extend all the way through the roll shell. The passages 21 are blind drilled of maximum depth. The passages 22 are shallower blind drilled openings.
Further, the blind drilled holes are preferably of smaller diameter, on the order of 0.02" to 0.1" in diameter. The shallower holes 22 are 1/4" deep, and the deeper holes 21 are 3/8" deep.
With the arrangement, the suction holes 20 are drilled at a spacing somewhat greater than currently used, i.e., 1.5 to 5 times the usual distance apart. This reduces the total area where low support is given in the manner illustrated in FIG. 2. Some vacuum will still exist at the shell surface to effect control over sheet transfer or direction, and to aid in water transfer. The blind drilled holes in combination with the suction holes attain a greater frequency over a shorter distance between holes than possible with the normal suction roll pattern where all of the holes are through drilled holes. The arrangement attains a better transfer of water into the felt and into the holes than where all through drilled holes are used because of the more uniform pressure applied to the web. This is caused by a smaller bridging area for the blind drilled holes, and yet accomplishing a greater number of openings within a given area. The hole distribution is such that the total open area on the roll face is 20% to 25% of the area.
As illustrated in FIG. 4, a preferred form of hole pattern is such that there are two blind drilled holes between every pair of through holes. One of these blind drilled holes is shallower than the other eliminating the shear plane.
The through holes 22 are of a commercially acceptable size on the order of 0.109" in diameter.
In operation, with reference to FIG. 1, the web and felt pass through the nip and dewatering occurs with a uniform pressure being applied to the web through the nip. Water passes into the felt and into the open holes 20 and blind drilled holes 21 and 22, and is thrown off on the offrunning side, and the felt is dried. A more uniform and better transfer of water occurs than with conventional suction roll drilling patterns with all through drilled holes or with the other forms of roll openings including conventional blind drilled openings, grooved rolls or fabric sleeve covers.
Thus, it will be seen that we have provided an improved press roll structure which accomplishes advantages and objectives above set forth, and we do not intend to be limited to the specific form of invention disclosed, but intend to cover all equivalents and modifications thereof. | A press roll for a press couple for dewatering a web in a papermaking machine wherein the roll preferably is a roll shell with certain of the drilled holes extending radially fully through the shell and certain other holes blind drilled to extend only a partial way into the shell and in one form, the shell having a rubber cover and the blind drilled holes extending alternate different depths to avoid shear planes in the rubber cover. | 3 |
BACKGROUND OF THE INVENTION
The present invention relates to the production of darkening and protection devices for windows or doors, e.g. curtains or mosquito nets, these curtains or nets rolling and unrolling on a cylinder structure.
In particular, the present invention relates to a mechanism for locking the curtains or mosquito nets in a desired position, usually open or closed, but mainly in any intermediate position.
DESCRIPTION OF THE PRIOR ART
Devices have heretofore been provided, as including a roll, on which the curtain or mosquito net rolls up, supported by suitable, substantially horizontal means.
This roll is usually introduced in a suitable case situated over, or in any case, near the upper edge of the window or door.
The free end of the curtain goes out of said case through a relative slot.
The curtain can be operated by a suitable drive member, basically including a pulley, which is integral with the roll and is connected to a relative, generally endless pull rope going out of the case at the sides of the pulley.
The roll is driven into rotation in the rolling direction by pulling down one of the rope ends, whereas it is driven into rotation in the unrolling direction by pulling down the other of the rope ends.
Suitable locking means, usually connected to the roll, allow the curtain to be firmly positioned, approximately in the desired point.
The main disadvantage of these locking mechanisms derives from the fact that they are not sufficiently resistant, when the curtain moves, either in rolling or unrolling direction.
These locking mechanisms must offer a sufficient resistance when the curtain is motionless, so as to maintain it in the predetermined position, overcoming possible action of elastic means connected to the roll, which would tend to roll it.
This locking mechanism can be formed by brakes, which elastically interfere with a support fastened to the roll on which the curtain is positioned.
The dimension of the brakes, wound around a suitable blocking part, prevents roll free rotation, if the curtain is not stressed from outside.
Other devices have been proposed, as shown in FIG. 1, in which the curtain control means C feature a hollow roll B, coaxial therewith, which has, made therealong, a slit B 1 cooperating with the ends D 1 , D 2 of a plurality of elastic means D, freely wound around an inner roller A, stationary and coaxial with the hollow roll B.
When suitable transmission means drive the control means C to rotate, the edges of the slit B 1 go in abutment against the ends D 1 , D 2 of the elastic means D, thus twisting them.
When one of the edges of the slit B 1 strikes the related end D 1 or D 2 respectively, the friction of the elastic means D, wound around the inner roller A and sliding therealong, is reduced, thus facilitating the curtain rolling and unrolling.
If the control means C are not operated by the user, the action of the elastic means D on the inner cylinder A determines a friction against mutual sliding, and the friction action is bigger than the weight action of the portion of the curtain not wound around the hollow roll B.
The above mentioned technical solutions are worldwide marketed, yet they have a very big drawback resulting from a considerable unreliability of the curtain positioning.
This unreliability is a direct consequence of the difference between the circumference arc corresponding to the transversal dimension of the slit B 1 and the distance between the ends D 1 , D 2 of the elastic means D; this is a problem particularly in case of mosquito nets.
Moreover, the more stressed components, in particular the edges of the slit B 1 of the hollow roll B and the ends D 1 , D 2 of the elastic means D, lack structural resistance.
If the locking mechanism maintenance, which is very expensive, is not proper, a structural deficiency of the hollow roll B in the slit B 1 area can seriously jeopardize the locking mechanism functionality, thus damaging its reliability.
Moreover, it is to be pointed out that the described technical solutions are obtained by using very expensive components and specialized manpower.
In fact, the cost of this mechanism depends on its dimension, which is related to the curtain dimensions.
Further, it is necessary to prepare a wide range of sizes for satisfying the market different needs.
SUMMARY OF THE INVENTION
This invention was evolved with the general object of avoiding the above mentioned drawbacks by proposing a mechanism for locking curtains and the like which guarantees a rapid, precise and stable locking in any position and in any angular position of the curtain supporting roll.
Another object of the present invention is to propose a locking mechanism, which is particularly strong and reliable in different working conditions.
A further object of the present invention is to propose a considerably versatile locking mechanism, which has almost the same size for curtains and nets of different dimensions.
Yet another object is to propose a locking mechanism obtained by a simple technical solution, which guarantees correct rolling and unrolling and which is extremely functional, reliable and cheap.
The above mentioned objects are obtained, in accordance with the contents of claims, in a mechanism for locking curtains and the like including a sleeve rotating about a longitudinal axis and fastened to a roll, in coaxial relation therewith, with a curtain or a similar article rolled up on said roll, said mechanism being fastened to a stationary support structure, by providing said mechanism with:
a barrel which enters freely said sleeve and couples firmly with said structure by relative coupling means, with said barrel featuring, made therein, at least one radial housing opening outside of said barrel;
at least one elastic element introduced freely in this radial housing and co-operating with friction means, said friction means being kept in contact with an inner surface of said sleeve due to the action of these friction means on the elastic element.
According to a different embodiment of the invention, the mechanism includes:
a barrel which enters freely said sleeve and couples firmly with said structure by relative coupling means;
a plurality of series of radial housings made in said barrel, with housings of each series all aligned and opening outside of said barrel, with corresponding axes of said housings being laid in a relative longitudinal plan passing through a longitudinal axis of this barrel;
at least one elastic element introduced freely in each radial housing and co-operating with relative friction means, said friction means being kept in contact with an inner surface of said sleeve due to the action of these friction means on the elastic element.
BRIEF DESCRIPTION OF THE DRAWINGS
The characteristic features of the present invention will become more fully apparent from the following detailed description of a preferred, but not sole, embodiment taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a schematic prospective view of the device described in prior art;
FIGS. 2 a , 2 b are schematic lateral corresponding views in axial section of the proposed locking mechanism in two different use conditions;
FIG. 3 is a section view taken along III—III of FIG. 2 a;
FIG. 4 is the same view of FIG. 3 of the proposed device according to another embodiment;
FIG. 5 is a schematic front sectional view of the device according to a further embodiment, taken along a plan perpendicular to the device axis;
FIG. 6 is a schematic lateral view in axial section of still another embodiment of the proposed device;
FIG. 7 is a lateral, partially section view of a different conformation of the proposed device;
FIG. 8 is a schematic, perspective exploded view of two different parts of the device shown in FIG. 7 .
With reference to the above mentioned drawings, the reference numeral 1 generally designates a mechanism for locking curtains and the like.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Mechanism 1 is substantially formed by a sleeve 3 featuring a ring-like seat 3 a made thereinside, near the inlet 3 b.
The seat 3 a goes in abutment with a flange 6 b of a barrel 6 introduced into the sleeve 3 coaxial therewith.
On its outer side, near the inlet 3 b , the sleeve 3 forms a drive member 4 , e.g. integral with this sleeve, which transmits a rotating motion to the sleeve 3 by a relative transmission element 4 a , e.g. a driving rope connected to this member 4 .
A hollow roll 5 , around which a curtain is wounded, is fastened outside the sleeve 3 coaxial therewith (FIG. 2 a ).
Near its flange 6 b , the barrel 6 is equipped with coupling means which comprise a seating 6 a , coaxial therewith, which couples with a tang 10 a formed by a stationary support structure, e.g. vertical (FIG. 2 a ).
The barrel 6 is provided with a plurality of radial housings 8 , aligned and arranged along a longitudinal plane which include the axis of the barrel 6 .
The housings 8 open in a longitudinal recess 9 made in the outer surface of the barrel 6 .
Friction means 7 , e.g. a cylinder, freely introduced into this longitudinal recess 9 , are kept always in contact with the inner surface 3 d of the sleeve 3 due to the elastic reaction exerted by elastic means 8 a on these friction means.
The elastic means 8 a are freely introduced into the radial housings 8 .
According to the embodiment shown in FIG. 4, this cylinder 7 features a flattening 7 a , on which the elastic means 8 a act.
It is possible to operate the drive member 4 by the rope 4 a starting from any static condition of the curtain wound around the hollow roll 5 , in both rolling and unrolling directions.
Rotation, thus imposed to the sleeve 3 , creates a low friction relative sliding and/or rolling motion between the cylinder 7 and the inner surface 3 d of the sleeve 3 .
This effect is obtained because the barrel 6 is locked to the stationary support structure 10 .
In this way, rolling and/or unrolling of the curtain, or other similar element, placed on the hollow roll 5 integral with the sleeve 3 , is facilitated.
The absence of the outer pull action on the drive member 4 creates a friction which prevents relative rotation of the sleeve 3 .
This is caused by elastic reaction of the elastic means 8 a , of suitable number and of proper characteristics, which pushes the cylinder 7 against the inner surface 3 d of the sleeve 3 .
In this way, a particularly static angular condition of the sleeve 3 with respect to the barrel 6 is obtained.
This condition can be altered by acting on the drive member 4 by the rope 4 a , in a predetermined way.
According to another embodiment, the locking mechanism includes a plurality of series of aligned radial housings 8 , arranged along relative longitudinal plans all including the barrel 6 axis and angularly equispaced.
The radial housings 8 of each series open in a related longitudinal recess 9 made in the outer surface of the sleeve 3 (FIG. 5 ).
This way, it is possible to stabilize in better way the angular configuration of the sleeve 3 and/or a sleeve 3 supporting a hollow roll 5 with a curtain of big dimensions and/or weight.
According to a further embodiment of the present invention, it is possible to obtain a regular positioning precision for the curtain by providing radial housings 8 , which do not open into a longitudinal recess 9 , but extend up to the outer surface of the barrel 6 (FIG. 6 ).
In this case, the most proper friction means 7 are spheres kept permanently in contact with the inner surface 3 d of the sleeve 3 by the elastic reaction of the elastic means 8 a.
Likewise, series of aligned radial housings 8 can be provided, arranged along relative longitudinal plans all including the barrel 6 axis and angularly equispaced.
According to a possible construction, the barrel 6 includes two bodies, an anchorage body 61 and an operative body 62 , which can be removably fastened to each other (FIGS. 7, 8 ).
In this case, the anchorage body 61 has coupling means which mesh with the support structure 10 , in a known way, by a splined coupling 11 a having grooved profiles provided with the support structure for entering a seating having a complimentary section made in the anchorage body portion of the barrel.
The anchorage body 61 features also a transversal slot 12 , made along an axial symmetry plane.
The operative body 62 includes a unit 13 , situated in the region of the coupling head 62 a and having a profile complementary to the transversal slot 12 into which it is introduced.
Likewise, the sleeve 3 is formed by two bodies, a reference body 31 and a support body 32 , which can be removably locked to each other.
The reference body 31 winds freely and tightly around the anchorage body 61 and is integral with the drive member 4 .
This reference body 31 has also a pair of longitudinal grooves 14 a , e.g. facing opposite directions, which couple with a corresponding pair of wings 14 , formed by the support body 32 .
The assembly constituted by the operative body 62 and the part of the support body 32 , without considering the wings 14 , is manufactured according to any one of the described embodiments, shown in FIGS. from 1 to 6 .
Basically, while the reference body 31 rotates with respect to the anchorage body 61 , the support body 32 , driven by the reference body 31 , rotates with respect to the corresponding operative body 62 .
Once the anchorage body 61 has been fastened to the support structure 10 , this solution allows a rapid and best mounting of the operative body 62 and the complementary support body 32 introduced into the relative head of the hollow roll 5 .
This way, when the barrel and the sleeve are coupled with the hollow roll 5 , they are not subjected to dangerous bending stresses, particularly in case of very big, and consequently heavy, curtains and the like.
The described locking mechanism in its proposed embodiments guarantees a rapid and precise positioning of curtains and like articles independently from the angular position of the curtain supporting roller.
This precision is guaranteed by the stabilizing action of the friction means, cylinders or spheres, which cooperate with the relative elastic means.
The compact and reduced structure of the barrel, equipped with a plurality of radial seats, allows to obtain a particularly strong locking mechanism, which is very reliable with a wide range of curtains and the like, thus permitting a substantial reduction of the number of sizes to be stored in magazine.
The possibility to easily stabilize the angular position of the sleeve by interaction of the elastic means with the relative friction means, makes the proposed mechanism very versatile, since it allows to work with almost constant dimensions, for different sizes of curtains and similar articles.
Moreover, it is to be pointed out that the number of the elements of the above described locking mechanism is limited and that they are very simple to manufacture, which is advantageous to the production costs.
It is understood that what above has been described as a mere, non limitative example, therefore possible constructive variants remain within the protective scope of the present technical solution, as described above and claimed in the following. | In a mechanism for locking curtains and the like, a sleeve rotates about a relative axis and is fastened to a roll, in coaxial relation therewith. A curtain is rolled up on the roll. A barrel features at least one radial housing opening outside of the barrel and enters freely the sleeve. The mechanism includes also one spring introduced freely in each radial housing and pushing a cylinder or a sphere against an inner surface of the sleeve. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 11/525,326, filed Sep. 22, 2006 now U.S. Pat. No. 7,308,612, which is a continuation of U.S. patent application Ser. No. 10/353,451 filed on Jan. 28, 2003 now U.S. Pat. No. 7,120,834, which claims the benefit of U.S. Provisional Application No. 60/368,936, filed on Mar. 29, 2002. The disclosures of the above applications are incorporated herein by reference.
BACKGROUND
The present invention relates generally to data communications. More particularly, the present invention relates to port failover in network switches and routers.
When a port fails in a network switch, the switch executes a failover process. In conventional failover processes, a processor, either within the switch or external to the switch, modifies forwarding tables in the switch. The forwarding tables are used by the switch to direct data from port to port. The failover process modifies the forwarding tables to redirect traffic away from the failed port to other ports in the switch.
One disadvantage of this approach is that modifying forwarding tables is a time-consuming process, especially in a large switch, because some or all of the information in one forwarding table is replicated across many forwarding tables, and/or because the forwarding tables are large. All of these forwarding tables must be modified. Until all of the forwarding tables are modified, data transmitted to the failed port either must be re-transmitted, or is lost.
SUMMARY
In general, in one aspect, the invention features a network switch comprising a plurality of ports each adapted to exchange frames of data with one or more network devices; a transfer circuit adapted to transfer the frames of the data between the ports; and wherein at least one of the ports comprises a loopback circuit adapted to send to the transfer circuit, when the one of the ports is not operational, each frame of the data received by the one of the ports from the transfer circuit, and a redirect circuit adapted to cause the transfer circuit to transfer, to one or more predetermined others of the ports, when the one of the ports is not operational, each frame of the data received by the transfer circuit from the one of the ports.
Particular implementations can include one or more of the following features. A destination address and a destination port identifier are associated with each of the frames of the data, wherein the destination address is associated with one or more of the network devices, wherein the destination port identifier identifies one or more of the ports, and wherein the transfer circuit comprises a forwarding engine adapted to forward each frame of the data from the one of the ports to one or more others of the ports according to the destination address associated with the frame of the data when the one of the ports is operational; wherein the redirect circuit comprises a replace circuit adapted, when the one of the ports is not operational, to replace, with destination identifiers of the one or more predetermined others of the ports, the destination port identifier associated with each frame of the data received by the one of the ports from the transfer circuit, and a forwarding override circuit adapted, when the one of the ports is not operational, to cause the forwarding engine to forward each frame of the data received by the transfer circuit from the one of the ports according to the destination port identifier associated with the frame, and not according to the destination address associated with the frame. Implementations comprise a memory adapted to store one or more forwarding tables containing associations between the ports and the destination addresses; wherein the forwarding engine is further adapted, when the one of the ports is operational, to forward each frame of the data according to the associations contained in the forwarding tables and the destination address associated with the frame of the data; and a controller adapted to modify the forwarding tables to replace the associations between the one of the ports and the destination addresses with associations between the one or more predetermined others of the ports and the destination addresses. A destination address and a destination port identifier are associated with each of the frames of the data, wherein the destination address is associated with one or more of the network devices, wherein the destination port identifier identifies one or more of the ports, wherein the transfer circuit comprises a forwarding engine adapted to forward each frame of the data from the one of the ports to one or more others of the ports according to the destination address associated with the frame of the data; wherein the redirect circuit comprises a replace circuit adapted, when the one of the ports is not operational, to replace the destination port identifier associated with each frame of the data received by the one of the ports from the transfer circuit with destination identifiers of the one or more predetermined others of the ports; and wherein the transfer circuit further comprises a bypass circuit adapted to forward, when the one of the ports is not operational, each frame of the data received by the transfer circuit from the one of the ports according to the destination port identifier associated with the frame, and not according to the destination address associated with the frame. Implementations comprise a memory adapted to store one or more forwarding tables containing associations between the ports and the destination addresses; wherein the forwarding engine is further adapted, when the one of the ports is operational, to forward each frame of the data according to the associations contained in the forwarding tables and the destination address associated with the frame of the data; and a controller adapted to modify the forwarding tables to replace the associations between the one of the ports and the destination addresses with associations between the one or more predetermined others of the ports and the destination addresses. The redirect circuit is implemented within at least one of the group comprising one or more port queues of the one of the ports; a media access controller of the one of the ports; and a physical layer device of the one of the ports. The loopback circuit is implemented within at least one of the group comprising one or more port queues of the one of the ports; a media access controller of the one of the ports; and a physical layer device of the one of the ports. The one of the ports and the one or more predetermined others of the ports are members of a link aggregation group, and the network switch further comprises a controller adapted to remove the one of the ports from the link aggregation group when the one of the ports is not operational. The controller, when a learning mode is enabled for the one of the ports, modifies the associations contained in the forwarding tables to associate the one of the ports with source addresses of frames of the data received by the forwarding engine from the one of the ports; and the learning mode is disabled for the one of the ports when the one of the ports is not operational.
In general, in one aspect, the invention features a port failover circuit for redirecting frames of data, sent to a port in a network switch by a transfer circuit in the network switch, to one or more other ports in the network switch, comprising a loopback circuit adapted to send to the transfer circuit, when the port is not operational, each frame of the data received by the port from the transfer circuit, and a redirect circuit adapted to cause the transfer circuit to transfer, to one or more predetermined others of the ports, when the port is not operational, each frame of the data received by the transfer circuit from the port.
Particular implementations can include one or more of the following features. A destination address and a destination port identifier are associated with each of the frames of the data, wherein the destination address is associated with one or more network devices, wherein the destination port identifier identifies one or more of the ports, and the redirect circuit comprises a replace circuit adapted, when the port is not operational, to replace, with destination identifiers of the one or more predetermined others of the ports, the destination port identifier associated with each frame of the data received by the port from the transfer circuit, and a forwarding override circuit adapted, when the port is not operational, to cause the transfer circuit to forward each frame of the data received by the transfer circuit from the port according to the destination port identifier associated with the frame, and not according to the destination address associated with the frame. The redirect circuit is implemented within at least one of the group comprising one or more port queues of the port; a media access controller of the port; and a physical layer device of the port. The loopback circuit is implemented within at least one of the group comprising one or more port queues of the port; a media access controller of the port; and a physical layer device of the port.
In general, in one aspect, the invention features a network comprising a first network device; a second network device; a network switch comprising a first port adapted to receive frames of the data from the first network device, a second port adapted to send the frames of the data to the second network device, one or more third ports adapted to send the frames of the data to the second network device, and a transfer circuit adapted to transfer the frames of the data from the first port to the second port, wherein the second port comprises a loopback circuit adapted to send to the transfer circuit, when the second port is not operational, each frame of the data received by the second port from the transfer circuit, and a redirect circuit adapted to cause the transfer circuit to transfer, to the one or more third ports, when the second port is not operational, each frame of the data received by the transfer circuit from the second port.
Particular implementations can include one or more of the following features. A destination address and a destination port identifier are associated with each of the frames of the data, wherein the destination address is associated with one or more of the network devices, the destination port identifier identifies one or more of the ports, and the transfer circuit comprises a forwarding engine adapted to forward each frame of the data to one or more of the ports according to the destination address associated with the frame of the data when the second port is operational; wherein the redirect circuit comprises a replace circuit adapted, when the second port is not operational, to replace, with the destination identifier of the one or more third ports, the destination port identifier associated with each frame of the data received by the second port from the transfer circuit, and a forwarding override circuit adapted, when the second port is not operational, to cause the forwarding engine to forward each frame of the data received by the transfer circuit from the second port according to the destination port identifier associated with the frame, and not according to the destination address associated with the frame. The network switch further comprises a memory adapted to store one or more forwarding tables containing associations between the ports and the destination addresses; wherein the forwarding engine is further adapted, when the second port is operational, to forward each frame of the data according to the associations contained in the forwarding tables and the destination address associated with the frame of the data; and a controller adapted to modify the forwarding tables to replace the associations between the second port and the destination addresses with associations between the one or more third ports and the destination addresses. A destination address and a destination port identifier are associated with each of the frames of the data, wherein the destination address is associated with one or more of the network devices, wherein the destination port identifier identifies one or more of the ports, wherein the transfer circuit comprises a forwarding engine adapted to forward each frame of the data to one or more of the ports according to the destination address associated with the frame of the data; wherein the redirect circuit comprises a replace circuit adapted, when the second port is not operational, to replace the destination port identifier associated with each frame of the data received by the second port from the transfer circuit with destination identifiers of the one or more third ports; and wherein the transfer circuit further comprises a bypass circuit adapted to forward, when the second port is not operational, each frame of the data received by the transfer circuit from the second port according to the destination port identifier associated with the frame, and not according to the destination address associated with the frame. Implementations comprise a memory adapted to store one or more forwarding tables containing associations between the ports and the destination addresses; wherein the forwarding engine is further adapted, when the second port is operational, to forward each frame of the data according to the associations contained in the forwarding tables and the destination address associated with the frame of the data; and a controller adapted to modify the forwarding tables to replace the associations between the second port and the destination addresses with associations between the one or more third ports and the destination addresses. The redirect circuit is implemented within at least one of the group comprising one or more port queues of the second port; a media access controller of the second port; and a physical layer device of the second port. The loopback circuit is implemented within at least one of the group comprising one or more port queues of the second port; a media access controller of the second port; and a physical layer device of the second port. The second port and the one or more third ports are members of a link aggregation group, and the network switch further comprises a controller adapted to remove the second port from the link aggregation group when the second port is not operational. The controller, when a learning mode is enabled for the second port, modifies the associations contained in the forwarding tables to associate the second port with source addresses of frames of the data received by the forwarding engine from the second port; and the learning mode is disabled for the second port when the second port is not operational.
In general, in one aspect, the invention features a method and computer-readable media for handling port failover in a network switch comprising a plurality of ports, wherein each of the ports is adapted to exchange frames of data with one or more network devices, and a transfer circuit for transferring the frames of the data between the ports. It comprises detecting that one of the ports is not operational; sending to the transfer circuit, when the one of the ports is not operational, each frame of the data received by the one of the ports from the transfer circuit, and causing the transfer circuit to transfer, to one or more predetermined others of the ports, when the one of the ports is not operational, each frame of the data received by the transfer circuit by the one of the ports.
Particular implementations can include one or more of the following features. A destination address and a destination port identifier are associated with each of the frames of the data, wherein the destination address is associated with one or more of the network devices, wherein the destination port identifier identifies one or more of the ports, wherein the transfer circuit forwards each frame of the data from the one of the ports to one or more others of the ports according to the destination address associated with the frame of the data when the one of the ports is operational, and wherein causing the transfer circuit to transfer comprises replacing, with destination identifiers of the one or more predetermined others of the ports, the destination port identifier associated with each frame of the data received by the one of the ports from the transfer circuit, and causing the transfer circuit to forward each frame of the data received by the transfer circuit from the one of the ports according to the destination port identifier associated with the frame, and not according to the destination address associated with the frame. The network switch transfers the frames of the data between the ports according to one or more forwarding tables containing associations between the ports and the destination addresses, and wherein the method further comprises modifying the forwarding tables to replace the associations between the one of the ports and the destination addresses with associations between the one or more predetermined others of the ports and the destination addresses. The one of the ports and the one or more predetermined others of the ports are members of a link aggregation group, and the method further comprises removing the one of the ports from the link aggregation group when the one of the ports is not operational. The network switch, when a learning mode is enabled for the one of the ports, modifies the associations contained in the forwarding tables to associate the one of the ports with source addresses of frames of the data received by the transfer circuit from the one of the ports, and wherein the method further comprises disabling the learning mode for the one of the ports when the one of the ports is not operational.
The details of one or more implementations are set forth in the accompanying drawings and the description below. Other features will be apparent from the description and drawings, and from the claims.
DESCRIPTION OF DRAWINGS
FIG. 1 shows a distributed multilayer switch according to a preferred embodiment.
FIG. 2 shows detail of a port of the switch of FIG. 1 according to a preferred embodiment.
FIG. 3 shows a fast failover process according to a preferred embodiment.
FIG. 4 shows a fast failover process for a port belonging to a link aggregation group according to a preferred embodiment.
FIG. 5 shows detail of a media access controller according to one embodiment.
FIG. 6 shows detail of physical layer device according to one embodiment.
FIG. 7 shows detail of a port queue according to one embodiment.
The leading digit(s) of each reference numeral used in this specification indicates the number of the drawing in which the reference numeral first appears.
DETAILED DESCRIPTION
FIG. 1 shows a distributed multilayer network switch 100 for transferring frames of data between network devices such as switches, routers, computers, and other network-enabled devices, according to a preferred embodiment. Although aspects of the invention are described with respect to this embodiment, this description applies equally well to distributed multilayer routers, distributed single-layer routers and switches, non-distributed multilayer routers and switches, non-distributed single-layer routers and switches, and similar devices. Switch 100 includes an optional switch fabric 102 , a supervisor card 104 , and a plurality of line cards 106 A through 106 N. Supervisor card 104 includes an optional master central processing unit (CPU) 108 . Each line card 106 includes a memory 118 , one or more ports 114 A through 114 N, an optional local CPU 116 , and a transfer circuit 114 that includes a forwarding engine 110 and an optional bypass circuit 126 . Memory 119 stores one or more forwarding (FWD) tables 112 and an optional link aggregation (LAG) table 120 . Port 114 communicates with a network 124 by exchanging frames of data.
Associated with each frame of data are a source address that is associated with the network device that is the source of the frame, a destination address that is associated with the network device that is the destination of the frame, and one or more destination port identifiers that identify ports 114 in the network switch 100 . In some cases an address that is associated with a network device identifies the network device. In other cases, such as with protocols like ATM and MPLS, an address that is associated with a network device identifies a path for the network device. Forwarding tables 112 contain associations between the addresses and ports 114 . Forwarding tables 112 can include bridge tables, internet protocol (IP) next hops tables, multi-protocol layer switching (MPLS) next hops tables, tunnels tables, address translation tables for different layers, and the like. Forwarding tables 112 can be populated before provisioning of the network switch 100 and/or by learning processes executed during the operation of the network switch 100 . For example, when a learning mode is enabled for a port 114 , a controller such as local CPU 116 , master CPU 108 , or some other device modifies the associations contained in the forwarding tables to associate the port 114 with the source addresses of frames received by forwarding engine 110 from the port 114 .
Forwarding engine 110 uses information stored in forwarding tables 112 to transfer the frames between the ports 114 in a line card 106 , and between the ports 114 on one line card 106 and the ports 114 on other line cards 106 . When all of the ports are operational, forwarding engine 110 uses information stored in forwarding tables 112 and the destination addresses of the frames to transfer the frames between the ports 114 . For example, when forwarding engine 110 receives a frame from a port 114 , it replaces the destination port identifier associated with the frame with the port identifier for the port associated with the destination address of the frame using the associations contained in forwarding tables 112 .
FIG. 2 shows detail of a port 114 according to a preferred embodiment. Port 114 includes a media access controller (MAC) 202 in communication with forwarding engine 110 and a physical layer device (PHY) 204 in communication with network 124 . MAC 202 and PHY 204 together transfer data between network 124 and forwarding engine 110 through port 114 . Port 114 further comprises one or more port queues 210 to store data handled by port 114 . PHY 204 communicates with network 124 using a network-side interface 222 , and communicates with MAC 202 using a MAC-side interface 220 . MAC 202 communicates with PHY 204 using a PHY-side interface 218 , and communicates with port queue 210 using a queue-side interface 216 . Port queue 210 communicates with MAC 202 using a MAC-side interface 214 , and communicates with forwarding engine 110 using a switch-side interface 212 . Port 114 also includes a redirect register 206 , the contents of which identify one or more backup ports associated with the port 114 , as described in detail below.
Conventional ports in a network switch often include a feature referred to as “loopback mode.” Loopback mode is conventionally used as a diagnostic procedure in which a frame egressed by a port is then ingressed by the port. The returned frame can be compared with the transmitted frame to evaluate the integrity of the port or the communications link serving the port. Referring to FIG. 2 , a frame of data is ingressed by a port when it is received by network-side interface 222 of PHY 204 , PHY-side interface 218 of MAC 202 , or MAC-side interface 214 of port queue 210 . A frame of data is egressed by a port when it is received by MAC-side interface 220 of PHY 204 , queue-side interface 216 of MAC 202 , or switch-side interface 212 of port queue 210 .
The inventor has recognized that loopback mode can be used for another purpose. In a preferred embodiment, loopback mode is used as part of a fast failover process to redirect frames forwarded to a failed port 114 by forwarding engine 110 so that the frames are instead forwarded to one or more other ports 114 in the network switch 100 , referred to herein as “backup ports.” In this process, loopback mode is implemented by a loopback circuit that can be implemented within one or more of the port queues 210 of the network switch 100 , within the media access controller 202 of the failed port 114 , within the physical layer device 204 of the failed port 114 , or by other methods. The loopback circuit implements loopback mode in response to the failure of the port 114 . A redirect circuit then redirects the frames returned by the loopback circuit to the backup ports, as described in detail below.
FIG. 3 shows a fast failover process 300 according to a preferred embodiment. Portions of process 300 can be implemented by local CPU 116 , by master CPU 108 , forwarding engine 110 , and by controllers located within ports 114 or elsewhere in network switch 100 . Although the steps of process 300 are described in a particular order, other embodiments can execute the steps in other orders, as will be apparent to one skilled in the relevant art after reading this description.
Process 300 begins when switch 100 detects the failure of a port 114 (that is, that the port 114 is not operational—step 302 ). Switch 100 can detect the failure of the port 114 by any of several methods well-known in the relevant arts. For example, port failure can be detected by the physical layer device 204 in the port 114 , by the media access controller 202 in the port, by devices at other layers in the port, or by a controller such as the local CPU 116 or the master CPU 108 . For example, the local CPU 116 can determine that a port 114 has failed when the port attempts to egress a frame of data a predetermined number of times, by testing a register bit in the port, or by like methods.
In a preferred embodiment, the fast failover process 300 can be enabled or disabled for each port 114 . Therefore process 300 determines whether fast failover is enabled for the failed port 114 (step 304 ). If fast failover is disabled for the failed port 114 , process 300 informs the application layer of the network switch software of the port failure (step 318 ), preferably using a top-layer application programming interface executing on master CPU 108 , and then ends (step 320 ). The application layer then modifies the forwarding tables 112 according to conventional methods. For example, the application layer modifies the forwarding tables 112 to replace the associations between addresses and the failed port 114 with associations between the addresses and the backup ports.
But if fast failover is enabled for the failed port 114 , process 300 places the failed port 114 in a mode referred to herein as “redirect mode” (step 312 ). In redirect mode, a port 114 causes transfer circuit 122 to transfer all frames received from the port 114 to one or more predetermined backup ports 114 regardless of the content of the frames, such as layer-2 and layer-3 addresses.
The identity of the backup ports associated with a port 114 is preferably stored in a redirect register 206 in the port 114 . When a port 114 belongs to a link aggregation group, the contents of redirect register 206 identify the link aggregation group. When a port 114 does not belong to a link aggregation group, the contents of redirect register 206 identify a backup port 114 ; in this case the redirect register 206 is preferably loaded before provisioning of the network switch 100 . Redirect mode is preferably implemented by a redirect circuit that can be implemented within one or more of the port queues 210 of the network switch 100 , within the media access controller 202 of the failed port 114 , within the physical layer device 204 of the failed port 114 , or by other methods.
The redirect circuit implements redirect mode in response to the failure of the port 114 . The redirect circuit replaces the destination port identifier associated with each frame received by the failed port 114 from transfer circuit 122 with the destination port identifiers of one or more of the backup ports. In one embodiment, the redirect circuit then causes forwarding engine 110 to forward all frames received from the failed port 114 to the one or more backup ports 114 identified by the new destination port identifiers without regard to the destination addresses associated with the frames. In another embodiment, the redirect circuit causes bypass circuit 126 to forward all frames received from the failed port 114 to the one or more backup ports 114 identified by the new destination port identifiers.
As mentioned above, switch 100 can populate forwarding tables 112 using a learning process. As part of this process, each time a switch 100 ingresses a frame on a port 114 , the switch associates that port 114 with a source address of the frame, such as a media access control (MAC) address. However, when a port 114 is in loopback mode, such learning is not beneficial. Therefore, process 300 disables address learning (step 314 ) so that frames returned to the failed port 114 by the loopback circuit will not be learned.
Process 300 then places the port in loopback mode (step 316 ). At this point in the process 300 all frames sent to the failed port 114 to be egressed by the port 114 are instead transmitted to one or more backup ports 114 . These backup ports 114 then egress the frames.
Finally process 300 informs the application layer of the network switch software of the port failure (step 318 ), preferably using a top-layer application programming interface executing on master CPU 108 , and then ends (step 320 ). The application layer then modifies the forwarding tables 112 to direct traffic away from the failed port 114 as described above.
FIG. 4 shows a fast failover process 400 for a port belonging to a link aggregation group according to a preferred embodiment. A link aggregation group is a group of two or more physical ports 114 that act as a single logical port, as is well-known in the relevant arts.
Portions of process 400 can be implemented by local CPU 116 , master CPU 108 , forwarding engine 110 , and by controllers located within ports 114 or elsewhere in network switch 100 . Although the steps of process 400 are described in a particular order, other embodiments can execute the steps in other orders, as will be apparent to one skilled in the relevant art after reading this description.
Process 400 begins when switch 100 detects the failure of a port 114 (that is, that the port 114 is not operational—step 402 ). Switch 100 can detect the failure of the port 114 by any of several methods well-known in the relevant arts. For example, port failure can be detected by the physical layer device 204 in the port 114 , by the media access controller 202 in the port, by devices at other layers in the port, or by a controller such as the local CPU 116 or the master CPU 108 . For example, the local CPU 116 can determine that a port 114 has failed when the port attempts to egress a frame of data a predetermined number of times, by testing a register bit in the port, or by like methods.
In a preferred embodiment, the fast failover process 400 can be enabled or disabled for each port 114 . Therefore process 400 determines whether fast failover is enabled for the failed port 114 (step 404 ). If fast failover is disabled for the failed port 114 , process 400 informs the application layer of the network switch software of the port failure (step 418 ), preferably using a top-layer application programming interface executing on master CPU 108 , and then ends (step 420 ). The application layer then modifies the forwarding tables 112 as described above.
Process 400 removes the failed port 114 from the link aggregation group (step 410 ). Each line card 106 optionally includes a link aggregation group (LAG) table 120 stored in memory 118 that lists the ports 114 that belong to each link aggregation group. Process 400 determines whether a port 114 belongs to a link aggregation group by reading the link aggregation table 120 , and removes a port 114 from a link aggregation group by writing to the link aggregation table 120 .
But if fast failover is enabled for the failed port 114 , process 400 then places the failed port 114 in “redirect mode (step 412 ). In redirect mode, a port 114 causes transfer circuit 122 to transfer all frames received from the port 114 to one or more predetermined backup ports 114 regardless of the content of the frames, such as layer-2 and layer-3 addresses, as described above. The backup ports are preferably the ports belonging to the link aggregation group to which the failed port 114 belongs. The identity of the link aggregation group is preferably stored in redirect register 206 in the port 114 .
As mentioned above, switch 100 can populate forwarding tables 112 using a learning process. As part of this process, each time a switch 100 ingresses a frame on a port 114 , the switch associates that port 114 with a source address of the frame, such as a media access control (MAC) address. However, when a port 114 is in loopback mode, such learning is not beneficial. Therefore, process 400 disables address learning (step 414 ) so that frames returned to the failed port 114 by the loopback circuit will not be learned.
Process 400 then places the port in loopback mode (step 416 ). At this point in the process 400 all frames sent to the failed port 114 to be egressed by the port 114 are instead transmitted to the backup port or ports 114 in the link aggregation group of the failed port, preferably according to a fairness scheme. These backup ports 114 then egress the frames.
Finally process 400 informs the application layer of the network switch software of the port failure (step 418 ), preferably using a top-layer application programming interface executing on master CPU 108 , and then ends (step 420 ). The application layer then modifies the forwarding tables 112 to direct traffic away from the failed port 114 as described above.
The failover processes 300 and 400 execute quickly regardless of the size of the network switch 100 because the duration of the fast failover process is unrelated to the number of line cards 106 , the number of forwarding tables 112 , and the size of the forwarding tables 112 . In general the interval between port failure and completion of the fast failover process is less than a millisecond.
FIG. 5 shows detail of MAC 202 according to one embodiment. MAC 202 includes a MAC engine 508 that performs media access control functions well-known in the relevant arts, queue-side interface 216 , and PHY-side interface 218 . According to this embodiment, MAC 202 also includes a loopback circuit 502 and a redirect circuit 514 . Redirect circuit 514 includes a replace circuit 506 and a forwarding override circuit 504 . Loopback circuit 502 includes a demultiplexer 510 and a multiplexer 512 . When port 114 is operational, multiplexer 510 directs all frames from queue-side interface 216 to MAC engine 508 and demultiplexer 512 directs all frames from MAC engine 508 to queue-side interface 216 .
But when port 114 is not operational, demultiplexer 510 directs all frames from queue-side interface 216 to replace circuit 506 . Replace circuit 506 replaces the destination port identifier associated with each frame as described above. Multiplexer 512 then directs the frames to queue-side interface 216 . While port 114 is not operational, forwarding override circuit 504 causes transfer circuit 122 to transfer the frames to the port identified by the new destination port identifier associated with the frame, rather than according to the destination address of the frame.
FIG. 6 shows detail of PHY 204 according to one embodiment. PHY 204 includes a PHY engine 608 that performs physical layer functions well-known in the relevant arts, MAC-side interface 220 , and network-side interface 222 . According to this embodiment, PHY 204 also includes a loopback circuit 602 and a redirect circuit 614 . Redirect circuit 614 includes a replace circuit 606 and a forwarding override circuit 604 . Loopback circuit 602 includes a demultiplexer 610 and a multiplexer 612 . When port 114 is operational, multiplexer 610 directs all frames from MAC-side interface 220 to PHY engine 608 and demultiplexer 612 directs all frames from PHY engine 608 to MAC-side interface 220 .
But when port 114 is not operational, demultiplexer 610 directs all frames from MAC-side interface 220 to replace circuit 606 . Replace circuit 606 replaces the destination port identifier associated with each frame as described above. Multiplexer 612 then directs the frames to MAC-side interface 220 . While port 114 is not operational, forwarding override circuit 604 causes transfer circuit 122 to transfer the frames to the port identified by the new destination port identifier associated with the frame, rather than according to the destination address of the frame.
FIG. 7 shows detail of port queue 210 according to one embodiment. Port queue 210 includes a switch-side interface 212 and MAC-side interface 214 . According to this embodiment, port queue 210 also includes a loopback circuit 702 and a redirect circuit 714 . Redirect circuit 714 includes a replace circuit 706 and a forwarding override circuit 704 . Loopback circuit 702 includes a queue controller 716 , an egress queue 710 , and an ingress queue 712 . When port 114 is operational, queue controller 716 directs all frames from egress queue 710 to MAC-side interface 214 and from MAC-side interface 214 to ingress queue 712 .
But when port 114 is not operational, queue controller 716 directs all frames from egress queue 710 to replace circuit 706 . Replace circuit 706 replaces the destination port identifier associated with each frame as described above. Queue controller 716 then directs the frames to ingress queue 712 . While port 114 is not operational, forwarding override circuit 704 causes transfer circuit 122 to transfer the frames to the port identified by the new destination port identifier associated with the frame, rather than according to the destination address of the frame.
While FIGS. 5 , 6 and 7 show the loopback and redirect circuits implemented within the same layer of the port 114 (that is, within only one of PHY 204 , AMC 202 or port queue 210 ), it will be apparent to one skilled in the relevant arts that the loopback and redirect circuits can be implemented in separate layers of the port.
The invention can be implemented in digital electronic circuitry, or in computer hardware, firmware, software, or in combinations of them. Apparatus of the invention can be implemented in a computer program product tangibly embodied in a machine-readable storage device for execution by a programmable processor; and method steps of the invention can be performed by a programmable processor executing a program of instructions to perform functions of the invention by operating on input data and generating output. The invention can be implemented in a hardware state machine, or advantageously in one or more computer programs that are executable on a programmable system including at least one programmable processor coupled to receive data and instructions from, and to transmit data and instructions to, a data storage system, at least one input device, and at least one output device. Each computer program can be implemented in a high-level procedural or object-oriented programming language, or in assembly or machine language if desired; and in any case, the language can be a compiled or interpreted language. Suitable processors include, by way of example, both general and special purpose microprocessors. Generally, a processor will receive instructions and data from a read-only memory and/or a random access memory. Generally, a computer will include one or more mass storage devices for storing data files; such devices include magnetic disks, such as internal hard disks and removable disks; magneto-optical disks; and optical disks. Storage devices suitable for tangibly embodying computer program instructions and data include all forms of non-volatile memory, including by way of example semiconductor memory devices, such as EPROM, EEPROM, and flash memory devices; magnetic disks such as internal hard disks and removable disks; magneto-optical disks; and CD-ROM disks. Any of the foregoing can be supplemented by, or incorporated in, ASICs (application-specific integrated circuits).
A number of implementations of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. List any additional modifications or variations. Accordingly, other implementations are within the scope of the following claims. | A network switch comprises a port that includes a redirect circuit and a loopback circuit that selectively redirects an egress frame to the redirect circuit when the port is non-operational. The redirect circuit replaces a destination port identifier associated with the egress frame to create a modified frame. The loopback circuit loops back the modified frame in an ingress direction. A transfer circuit transfers the modified frame to another port identified by the destination port identifier. | 7 |
RELATED APPLICATIONS
This application is a Continuation-in-Part of our U.S. Ser. No. 08/853,941, Filed: May 9, 1997 entitled "TAMPER RESISTANT COMBINATION LOCK", which is a Continuation-in-Part of our U.S. Ser. No. 08/584,459, Filed: Jan. 11, 1996, entitled "TAMPER RESISTANT COMBINATION LOCK", now U.S. Pat. No. 5,640,860, Issued: Jun. 24, 1997.
BACKGROUND OF THE INVENTION
Various types of weapons, including revolvers, automatic and semi-automatic pistols, rifles, and shotguns, and some less popular weapons such as fishing spearguns, usually are provided with safety mechanisms that prevent trigger actuation until a safety member is pressed or shifted to enable trigger movement. These devices are primarily intended to prevent inadvertent triggering while in the user's hands during hunting or cleaning. These safety mechanisms, however, have no tamper proof characteristics, and are not intended to, that will prevent or at least hinder a child or any person, from firing the weapon because these prior safeties are exposed and may be actuated by any person with a simple finger On-Off shifting motion of a button or lever. There have, however, in the past been provided several attractive trigger blocking devices for limiting access to the trigger area using covers clamped over the trigger area that permit removal of these covers only by activating an integral locking device. One such locking cover device is manufactured by CCL Security Products, Inc. named Gun Blok™ that utilizes a plurality of combination lock rings similar to those found on brief cases. This design is exemplified in U.S. Pat. No. 4,499,681.
The principal problem in these prior blocking devices is they are difficult for the weapon owner to open with ease, particularly at dark or night fall, and quite easy for the unauthorized to open easily with skill at a professional thief level.
The brief case type multiple ring combination lock, while possibly suitable for brief cases, provides inadequate security for a trigger blocking device. Single ring combination locks are also unsuitable for this purpose because they cannot be operated by the authorized user in the dark or night fall.
In our U.S. patent application, Ser. No. 08/853,941, Filed: May 9, 1997, and in its parent application, U.S. Ser. No. 08/584,459, Filed: Jan. 11, 1996, we describe and claim a Tamper Resistant Combination Lock that includes a housing having a through bore receiving a locking plunger with a plurality of integral spaced obstructions thereon, the housing having a plurality of transverse slots each receiving one of two identical blocking slides that snap between three distinct positions, one passing the obstructions and plunger, and two blocking the obstructions and plunger. Lock picking is minimized by flexible fingers in the slides that engage the plunger obstructions when the slides are in the plunger passing position to simulate the slide blocking positions as the lock picker tugs the plunger.
A preliminary patent search in that application yielded the following collection of United States patents: Enholm, U.S. Pat. No. 428,387; Battershell, U.S. Pat. No. 1,733,772; Legat, U.S. Pat. No. 1,898,974; Ponder, U.S. Pat. No. 2,740,530; Nemsky, U.S. Pat. No. 3,155,230; Esquibel, et al., U.S. Pat. No. 3,514,981; Feinberg, U.S. Pat. No. 3,597,945; Pedro, U.S. Pat. No. 3,865,166; Jones, Re. 30,139; Ippolito, et al., U.S. Pat. No. 4,187,703; Gordon, U.S. Pat. No. 4,463,847; Terada, et al., U.S. Pat. No. 5,081,855; Jarboe, U.S. Pat. No. 5,125,661; and Blanchard, U.S. Pat. No. 5,322,200.
The Ippolito, et al., U.S. Pat. No. 4,187,703, shows a locking system applied to an envelope defined by a pair of spaced plates, holding a numismatic coin. The Ippolito device has a slide plate 14 with cross slots 16 transversely positioned away from a central longitudinal slot 18. The transversely movable slides are all identical and can be positioned either in a right-hand or left-hand orientation as seen in FIG. 9. This arrangement, however, produces only two positions for each switch and, therefore, yields few combinations.
The Jarboe, U.S. Pat. No. 5,125,661, discloses a plunger-type locking mechanism, but there is really no logic in the lock combination because if all the plungers are depressed, the plunger 19 can be removed regardless of the position of blocks 35. Thus, it is not really a true combination lock at all.
The Esquibel, et al., U.S. Pat. No. 3,514,981, discloses a plunger-type locking mechanism for a box wherein a locking bar 14 is held or released by a plurality of slide bars 13 that have second slots 30 all positioned the same distance from the inner ends of the bars, and first slots 29 positioned in varying locations to correspond to one of the indicia on area 33 of the projecting ends of the bars 13. When the bars are slid to the appropriate indicia, the slots 29 permit the release of bars 14. The Esquibel, et al. lock has a total of only 48 combinations possible with five bars 13.
There is, however, no suggestion in this prior art as to how these prior combination lock mechanisms may be incorporated into a trigger blocking device and to that end the present application is directed.
Furthermore, in our U.S. application Ser. No. 08/584,459, and in our U.S. application Ser. No. 08/853,941, a combination lock is described that is not entirely suitable for trigger blocking devices because the number of combination slides should be over four and preferably six, and this design requirement would result in the lock projecting from the weapon at least 1.5 inches, making the weapon difficult to store or case in this condition. The combination slides can be reduced to 2 to minimize this problem, but then a two slide combination lock with three or less indexible positions is much easier to pick.
It is a primary object of the present invention to provide a tamper resistant blocking device that ameliorates the above problems in our prior United States patent applications and in the prior art relating to trigger blocking mechanisms by providing an improved tamper resistant locking device.
SUMMARY OF THE PRESENT INVENTION
In accordance with the present invention, a tamper resistant trigger blocking device is provided for weapons having trigger guards. This blocking device features a pair of blocking members that cover the opposite sides of the trigger guard preventing entry into the trigger area by unauthorized persons. The two blocking members are clamped together on the opposite sides of the trigger guard by a pair of oppositely disposed combination locks each of which has a plunger fixed to the other blocking member that extends into the lock that is grasped and pulled by each combination lock.
Movement of the blocking members in the plane of the trigger guard is minimized by a plurality of indexible rods in one blocking member that are engageable with both sides of the trigger guard. The user adjusts the positions of these rods to fit the user's trigger guard size and shape.
In the design of this new trigger blocking device, we have in essence adapted and altered the tamper resistant combination lock in our U.S. Ser. No. 08/584,459, and our U.S. Ser. No. 08/853,941, to accommodate the geometry of the trigger blocking device and to make it more suitable for that purpose. Toward these ends, we provide two combination locks, one on each of the blocking members that have three, rather than six, blocking slides. In this way the projection of the combination locks are minimized to facilitate casing, storing and transporting the weapon with the trigger blocking device in situ. It is necessary that the trigger blocking device be held securely against the sides of the trigger guard and toward that end the plungers in each of the trigger blocking members are axially adjustable by threading in and out so the blocking slides tension the plungers and pull the blocking members against the sides of the trigger guard.
Other objects and advantages of the present invention will appear more clearly from the following detailed description.
BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a side view of a flexible pistol case with the present tamper resistant combination lock fastened to its upper surface holding its zipper tang in a locked position with part of the fabric broken away near the lock mounting;
FIG. 2 is an enlarged fragmentary view of FIG. 1 showing the present tamper resistant combination lock and illustrating its manner of connection to the pistol case;
FIG. 3 is an exploded perspective illustrating the one piece lock housing with one of each of the two standard blocking slides;
FIG. 4 is a fragmentary section of the housing taken generally along line 4--4 of FIG. 3;
FIG. 5 is a side view of one of the standard blocking slides;
FIG. 6 is a side view of the other standard blocking slide;
FIG. 7 is a cross section through one of the blocking slides taken through the passing aperture showing the spring finger positions;
FIG. 8 is a cross section through the blocking slide in one of the blocking positions;
FIG. 9 is a sub-assembly view of the locking plunger;
FIG. 10 is an orthogonally rotated view of the locking plunger illustrated in FIG. 9;
FIG. 11 is an end view of the lock housing;
FIG. 12 is a side view of the lock housing;
FIG. 13 is a bottom view of the lock housing;
FIG. 14 is an end view of the L-shaped housing slide connector;
FIG. 15 is a side view of the connector illustrated in FIG. 14;
FIG. 16 is a bottom view of the connector illustrated in FIGS. 14 and 15;
FIG. 17 is a longitudinal section of the present tamper resistant lock with all six blocking slides shown in various positions;
FIG. 18 is an alternative form of the present tamper resistant lock shown and exemplified in a padlock-type lock;
FIG. 19 is a perspective view of another embodiment of the present tamper resistant lock assembly;
FIG. 20 is a cross-section taken generally along line 20--20 of FIG. 19 with a side pass slide therein;
FIG. 21 is a cross-section generally similar to FIG. 20 with a central pass slide therein;
FIG. 22 is an exploded view of the tamper resistant lock assembly illustrated in FIG. 19;
FIG. 23 is a partly fragmented section of a clamshell hard plastic case with the present tamper resistant lock assembly formed in part integrally therewith;
FIG. 24 is a top view of the tamper resistant lock assembly shown in FIG. 23;
FIG. 25 is an exploded perspective of the present tamper resistant trigger blocking device;
FIG. 26 is a right side view of the trigger blocking device illustrated in FIG. 25;
FIG. 27 is a left side view of the trigger blocking device illustrated in FIGS. 25 and 26;
FIG. 28 is a longitudinal section through the assembled trigger blocking device taken generally along line 28--28 of FIGS. 26 and 27;
FIG. 29 is a right side view of the right half of the trigger blocking device shown assembled into a phantom trigger guard, and;
FIG. 30 is a fragmentary section through one of the indexible rods, taken generally along line 30--30 of FIG. 29.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following is a reiteration of the text of our U.S. application Ser. No. 08/584,459, Filed: Jan. 11, 1996, with the understanding that the present tamper resistant trigger locking device illustrated in FIGS. 25 to 30 herein, incorporates the indexible slide technology, the obstruction styled plunger technology illustrated in FIGS. 1 to 24, and hence not shown in detail in FIGS. 25 to 30, and this text is also presented herein because the present application is a Continuation-in-Part of this prior application and thus entitled to the benefits of the filing dates of our above-noted applications for common subject matter.
Referring to the drawings and particularly FIGS. 1 and 2, the present tamper resistant combination lock assembly 10 is illustrated attached to a flexible pistol case 11 having a peripheral zipper 12 and a pivotal zipper tang 13 having a conventional aperture there-through held in a locked position by distal end 15 of a locking plunger 16 forming part of the combination lock 10.
As seen in FIGS. 3, 4, and 11 to 13, the lock housing 18 is seen to be generally rectangular in configuration and may be constructed of a one piece plastic molding. A central bore 20 extends longitudinally through the housing and it is intersected by six blocking slide receiving transverse slots 21, 22, 23, 24, 25 and 26. Note the configuration of the slots and bore shown in fragmentary form in FIG. 4. An additional end slot 27 is provided for receiving zipper tang 13.
As seen in FIGS. 11 and 12, the housing has three integral headed projections 29, 30, 31 extending downwardly therefrom that are designed to pass through apertures 34, 35 and 36 in the top wall of the pistol case 11. A key-hole type L-shaped connector 40 illustrated clearly in FIGS. 14, 15 and 16 has three key-hole type apertures 41 that receive the headed projections 29, 30 and 31 to lock the housing 18 and the lock 10 to the pistol case 11 in its appropriate position.
As seen in FIGS. 9 and 10, plunger 16, which can be easily constructed of a one piece plastic molding, includes a rod portion 43 having a finger loop 44 at one end and six integral spherical obstructions 44, 45, 46, 47, 48 and 49.
Two standard blocking slides 52 and 54 are illustrated respectively in FIGS. 5 and 6 (as well as FIG. 3). It should be understood that of the six slides in the exemplary embodiment illustrated, three take the form of slide 52 and three take the form of slide 54.
It should be understood as seen in FIGS. 3, 5 and 6, that the slides 52 and 54 are rectangular in configuration and identically configured on both sides of each so that the slides 52, 54 are reversible in slots 21 to 26.
Each of the slides is a one piece rectangular plastic molding, and slide 52 includes a central through aperture 56 having a diameter slightly larger than spherical obstructions 44 to 49. Aperture 56 has upper and lower key-type slots 58 and 59 that have molded therein integral spring fingers 60 and 61 shown also in FIG. 7. The spherical projection 49 in FIG. 7 is illustrated in the lock position of the plunger, and in this position the spring fingers 60 and 61 engage one side of the obstruction 49. As a would-be lock picker pulls outwardly on plunger loop 44, obstruction 49, because of its engagement with spring fingers 60 and 61, shifts the slide very slightly laterally in its slot the same way the obstruction would shift the slide when in its blocking position illustrated in FIG. 8. In this way, regardless of whether the slide is in its blocking position or in its passing position, when the plunger is pulled axially, each of the slides will shift in their respective slots making it impossible for the lock picker to distinguish between slides in the locking position and slides in the blocking position.
However, fingers 60 and 61 are sufficiently flexible so they fold down in their adjacent recesses when plunger 16 is pulled with all the slides in the obstruction passing position, permitting the distal end 15 of the plunger to release tang 13.
Returning to FIG. 5, slide 52 has a pair of transverse slots 64 and 65 having a height somewhat greater than the rod portions 43 of the plunger that receive the rod portion in the two blocking positions of slide 52. The slide 52 has side recesses 66 and 67 at the ends of the slots (on both sides of the slides) that receive the spherical plunger projections when the slide is in its blocking position that provide the snap action movement of the slides when force is applied to the plunger (see FIGS. 8 and 17 for exemplary illustrations of the spherical projections when in the blocking recesses).
The blocking slide 54 has the same outer geometry as the slide 52 but rather than a central aperture has a side aperture 70 that passes projections 44 to 49 and a lateral slot 71 that passes plunger portion 43 and extends through the central position of the slide and the other side position. Recesses 73 and 74 are provided on both sides of the slide aligned with the two blocking positions of the slide and are identical in geometry to recesses 66 and 67 in slide 52.
Because both sides of slide 54 are identical, this slide can be reversed in the slots 21 to 26 to effect either right side blocking or left side blocking as desired thereby increasing the possible combinations of the lock without requiring the tooling for a third slide.
As seen in FIG. 17, plunger 44 is in its locked position and in this position the spherical projections 44 to 49 are either partly in one of the passing apertures 56 in slides 52 or 70 in slides 54, or in one of the blocking recesses 66, 67, 73, 74. The position of the loop 44 close to housing 18 holds the spherical projections 44 to 49 in either the blocking recesses or through apertures in the slides. However, there is still a small amount of play there-between.
In use, and in reference particularly to FIG. 17, assume that each of the blocking sides 52a, 52b, 52c, 54a, 54b, and 54c are in their plunger passing positions and that plunger 16 is partly withdrawn with its distal end 15 short of end slot 27. Gun case zipper 12 is then closed and its tang 13 positioned as shown, then plunger 44 is shifted to the left impaling the aperture in the zipper tang and moving the plunger to its locking position illustrated in FIG. 17.
Slides 52 and 54 are then all shifted away from the passing positions to one of the two blocking positions of each. Unlocking is, of course, effected by shifting each of the slides from one's memory or notes to its passing position. Because each of the blocking slides has only three positions and these positions are distinct, it is relatively easy to memorize the lock combination and also relatively easy for the lock user to unlock the lock from memory simply by "feeling" the position of the slides even in the dark.
The lock combination can be changed by either switching one or more slides 52 with one or more slides 54 or by rotating one or more slides 54 180 degrees in its slot as noted above.
FIG. 18 illustrates an alternative form of the present invention and is exemplified as a combination padlock, and is seen to include a rectangular padlock housing 80 having a main bore 82 there-through and a secondary bore 83 extending partly there-through that receives a distal end 84 of a U-shaped portion 85 of plunger 86. The housing 81 has a plurality of transverse slots 87 there-through that receive a plurality of blocking slides 89 that effect selective blocking of spherical obstructions 90 formed on the plunger 86.
The portion of the plunger 86 slidable in main passage 82 is identical to the corresponding portion of plunger 16 in the FIGS. 1 to 17 embodiment and blocking slides 89 are identical to blocking slides 52 and 54 also illustrated with respect to the FIG. 17 embodiment. The plunger 86 and U-shaped portion 85 are rotatable in housing main passage 82 to effect the desired swiveling motion in a padlock and, of course, the symmetrical shape of the plunger portion in bore 82 and the spheroidal configuration of obstructions 90 conveniently accommodate the desired pivotal, as well as reciprocal, motion of U-shaped plunger portion 85 as distal end 84 moves in and out of secondary passage 83 and swivels toward and away from the lock body 81.
Referring to FIGS. 19 to 22, which illustrate an alternative embodiment 110 of the present tamper resistant lock assembly, it should be understood that this lock operates in substantially the same manner as the lock illustrated in FIGS. 1 to 17, as well as the lock illustrated in FIG. 18, in the drawings. Lock assembly 110 includes a block-like housing 111 consisting of a lower housing half 112 and an upper housing half 113, that are locked together by inter-engaging projections 116 that in upper housing half 111 lock into recesses not shown in lower housing half 112.
The lock 110 is held in position on its associated case by a backing plate 118 that fits within the case, held in position by a plurality of fasteners 120 and 121 that extend through lower housing half apertures 124 and are threaded into apertures 125 in the upper housing half 113 to not only lock the entire lock assembly in position but also to lock the housing halves together in a tamper resistant fashion because fasteners 120 and 121 are inside the locked case.
As seen in FIG. 21, which is an enlarged cross-section through FIG. 19, the housing 111 has through slots 127 that correspond with the slots in the FIGS. 1 to 17 embodiment, and each receive a central pass slide member 128, which function in a similar way to the slides shown in the FIGS. 1 to 17 embodiments. Slide 128 has a central aperture 131 having a diameter greater than the spheroidal blocking obstructions 134 on the plunger 133 to permit the plunger to be withdrawn when the slide 128 is in its central passing position. As in the FIGS. 1 to 17 embodiment, the passing aperture 131 is positioned in second slides 135 shown in FIG. 20, in one of the side apertures as opposed to the central aperture. The slide 128 has four flexible fingers 132 that are positioned on a diameter less than the diameter of spheroidal obstructions 134 to interfere with the obstructions 134 and function in the same way as fingers 60 and 61 illustrated in FIG. 5 to effect shifting of the slides 128 and 135 as the lock picker tugs on the plunger 133 to simulate a blocking position of the slides 128 and 135 when in fact they are in the passing position. Fingers 132 move radially with respect to the axis of the plunger 133 as opposed to the general axial bending movement of the fingers 60 and 61 in the FIG. 5 embodiment.
The two side positions of the slides 128 are defined by spheroidal recesses 136 and 137 that partly receive the end of the projections 134 to provide the snap action movement of the slides 128 when tension is applied to the plunger 133 in a manner similar to the FIGS. 1 to 17 embodiment. The depth of the recesses 136 and 137 is selected so that the plunger obstructions 134 engage the bottom of the recesses 136 and 137 with the same axial movement of the plunger 133 as when the plunger obstructions 134 engage the fingers 132.
The aperture 131 in FIG. 21 is contiguous with side slots 151 and 152 and they permit the slides to be shifted to their side positions aligning one of the spheroidal recesses 136 and 137 with the axis of plunger 133.
As with the FIGS. 1 to 17 embodiment, the snap action movement of the slide 128 to its three positions is achieved with tension being applied to the plunger 133 engaging the obstructions 134 in the recesses 136 and 137 or against the fingers 132, and as the slide 128 is shifted with that tension being applied, the user or lock picker can feel the snap action movement of the slides 128. The same is true of the slides 135.
According to the FIGS. 19 to 21 embodiment, means are provided to prevent the slides 128 and 135 from falling out of the housing 111 when the plunger 133 is completely withdrawn. Toward this end, a slot 140 is provided in the slides 128 and 135 that defines an upwardly arching integral leaf spring 141 that engages the upper surface 142 of slot 127 to continuously bias slides 128 and 135 downwardly toward the bottom of the slots 127. The bottom of each of the slots 127 has an axial projection 143 that selectively engages one of three recesses 144 to hold the slides in one of its three capable positions.
In FIGS. 23 and 24, a clamshell-type rigid plastic case 160 is illustrated having case halves 161 and 162 that close together from the position shown in FIG. 23 to the top view closed position illustrated in FIG. 24. Case half 162 has an integral tang 164 with an aperture 165 therein, that receives a plunger 166 on lock assembly 167 that locks the case halves 161 and 162 together.
Lock assembly 167 consists of a lower housing half 169 that mates with an upper housing half 170 connected together by interlocking male and female projections 171 and 172. Housing halves 169 and 170 can also be connected together by tamper proof fasteners that extend from inside the case 160 in a similar fashion to fasteners 120 and 121 illustrated in FIG. 22. An important aspect of the lock 167 is that the lower housing half 169 is molded integrally with case half 161 providing not only an extremely low cost lock assembly, but one that is cosmetically attractive in the sense that it appears more integrated with the case 160.
Referring to FIGS. 25 to 30 wherein a trigger blocking device 210 is illustrated, it should be understood that the details of the indexible slides, and the operation of the combination locks illustrated herein, are identical to those shown and described in reference to FIGS. 1 to 24, and hence are incorporated by reference into the FIGS. 25 to 30 embodiment.
Viewing FIGS. 25 to 30, the tamper resistant blocking device 210 is seen to include a first blocking member assembly 211 and a second blocking member assembly 212. The blocking member assembly 211 is seen to include an ellipsoidal blocking member portion 214 that has the general configuration of a trigger guard, such as the trigger guard illustrated in FIG. 29. It should be understood, however, that the blocking member assemblies 211 and 212 are intended to fit over a variety of sized trigger guards so that they may overlap the trigger guard to a greater extent, in some models, than illustrated in FIG. 29 to accommodate a variety of trigger guards. It may also be desirable that the tamper resistant blocking device 210 be provided in a variety of sizes, however, to accommodate significantly different trigger guard configurations. The forward surface of the blocking member portion 214 is preferable rubberized to grip the sides of the trigger guard and possibly portions of the weapon receiver immediately above the trigger guard. The blocking assembly 211 further includes a combination lock 213 similar to that described with reference to FIGS. 1 to 24, having three indexible slides 215 slidable in slots 216 in block body 217. A central aperture 219 (FIG. 28) is provided intersecting the slots 216 that receives a plunger 220 carried by blocking device 212 having a plurality of obstructions 221 thereon.
As seen in FIG. 28, the rubberization of the forward surface of the blocking member portion 214 is achieved by a Neoprene "sock" 224 that has a flange 225 that fits over the rear of blocking member portion 214. As seen in FIG. 28, the housing 217 and the blocking member portion 214 are one piece. The sock 224, and principally its resilient forward surface, enables the members 213 and 212 to be squeezed against the sides of the trigger guard as the combination locks 213 and 238 are engaged. Also, the sock minimizes scratching the weapon.
The trigger blocking member 212 is similar to trigger blocking member 211 except several of the parts are vertically reversed; i.e., rotated 180 degrees. Blocking member 212 includes a housing 230 having a lower threaded bore 231 that receives a threaded shank portion 232 of the plunger 220 that forms part of the locking mechanism for combination lock 213 associated with blocking member assembly 211. Blocking member 212 includes a second combination lock 238 vertically above and in the same vertical plane as combination lock 213. Combination lock 238 is simply a reversal of combination lock 213 and includes three blocking slides 240 in cross slots 241 which intersect a main passage 242 that receives a plunger 245 identical to plunger 220 having the same obstructions and a threaded shank portion 246 threadedly received in a threaded bore 247 formed in housing 217 of blocking member assembly 211. A Neoprene sock 248 identical to Neoprene sock 224 covers the blocking member portion 248 integral with and defining the forward part of housing 230.
The present tamper resistant blocking assembly 210 includes a system of indexible rods for minimizing lateral movement of the assembly with respect to the trigger guard, and also is effective to lock the trigger itself in position to prevent the discharge of the weapon if dropped on the ground with the blocking device 210 in position.
Toward this end and as seen in FIGS. 25 and 29, there are a plurality of bores 250 to 270 strategically arranged in the forward portion of the housing 230. Housing 217 has a similar plurality of bores (not shown) arranged in mirror image and aligned with bores 250 to 270. A plurality of indexible and removable rods 275 are selectively received in bores 250 to 270 having their distal ends supported in the complementary bores in housing 217 when assembled on the weapon. The rods 275 have spheroidal forward ends 276 and integral proximal rings 277 that snap into recesses 278 in each of the bores 250, etc. to hold the rods 275 in position. Rods 275 are one piece plastic injection moldings or plastic coated metal.
The positioning of the bores 250 to 270 is strategic to adapt the blocking assembly 210 to accommodate a wide variety of housing and trigger configurations. The bores 251, 253, 255, 259, 254, 258, and 263 are adapted to selectively receive rods 275 for engagement with either side of the rear portion 277 of the trigger guard. Bores 250, 252, 264 and 265 are positioned to selectively receive rods 275 to engage the lower portion of the receiver housing. Bores 256, 257, 258, 261, 260 and 262 are adapted to receive rods 275 to engage the rear of trigger 279 to prevent trigger actuation. Lastly, bores 266, 267, 268, 269 and 270 are positioned to receive rods 275 to engage the forward portion 280 of the trigger guard. In this regard it should be understood that while the bores 250, etc. shown in FIG. 29 are positioned mostly within the specific trigger guard illustrated so pins 275 engage the inner surface of the trigger guard, in weapons having smaller trigger guards than the trigger guard illustrated in FIG. 29, some of the pins 275 may fall outside of the trigger guard and can receive pins 275 to engage the outside of the guard. That is in some cases, the pins 275 can be positioned on both sides of the trigger guard rather than simply on the inside shown in FIG. 29.
For the trigger guard shown in FIG. 29, the user would select bore 250 to receive rod 275a to engage the lower part of the receiver, he would position a pin 275c in bore 259 to engage the inner surface of the rear portion 277 of the trigger guard, he would position rod 275c in bore 260 to engage the rear of the trigger 279 to prevent inadvertent triggering, he would position rod 275d in bore 265 to engage the forward lower surface of the receiver, and he would position rod 275e in bore 269 to engage the inner surface of the forward portion 280 of the trigger guard.
While the appropriate positioning of the rods 275 in the bores 250, etc., may seem complex, in actuality the user task is fairly simple. The user simply places the trigger blocking assembly 212 adjacent one side of the trigger guard without the opposite blocking assembly 211 in place. He then essentially sees what is viewed in FIG. 29. In this position the rods 275 can be easily inserted into the appropriate bores 250, etc. to achieve a locking configuration. Once this task is achieved, it is unnecessary for the rods 275 to be repositioned except when the blocking assembly 210 is to be adapted to a different weapon.
To assure that the blocking assemblies 211 and 212 are held firmly against the trigger guard, the user axially adjusts the plungers 220 and 245 to a position where the obstructions 221 are appropriately tensioned by the slides 215 and 240. Once this adjustment is made, it is unnecessary for the user to make further changes unless it is desired that the blocking assembly be used for a different weapon. | A tamper resistant trigger blocking device for weapons having a trigger guard featuring a pair of blocking members that cover the opposite sides of the trigger guard preventing entry into the trigger area. The two blocking members are clamped together by a pair of oppositely disposed combination locks each of which has a plunger in the other blocking member that is grasped by the combination locks. Movement of the blocking members in the plane of the trigger guard is minimized by a plurality of indexible rods in one of the blocking members that are engageable with both sides of the trigger guard to prevent that movement. The user adjusts the positions of these rods to fit the user's trigger guard size and shape. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a joint for connecting coaxial pipes together and, more particularly, it relates to a joint for connecting coaxial pipes which if so arranged that a plurality of pipes of one of the coaxial pipes can be simultaneously connected with corresponding pipes of the other of the coaxial pipes, respectively, and the respective ones of the connected portions can be sealed by a single packing.
2. Description of the Prior Art
Heretofore, a construction for connecting one pipe to another pipe has been widely used and various joints for connecting the pipes have been developed and carried into practical use. Furthermore, some constructions have been practically used to connect coaxial pipes together. The coaxial pipe has been employed with various purposes. With reference to a double pipe including an inner pipe and an outer pipe, for example, it is utilized in the following manners.
(1) It is used to carry a combustible gas, a poisonous gas or other dangerous fluids. In this case, the inner pipe is used to carry the dangerous fluid, while the outer pipe is used as emergency means or leakage prevanting means for preventing the fluid from leaking outside when a leakage of the fluid may occure from the inner pipe owing to a damage thereof or the like.
(2) It is used as a heat exchanger. In this case, fluids at different temperatures are passed through the inner pipe and the outer pipe, so that a heat exchange is effected between these fluids.
(3) It is used to feed a high-temperature fluid. If a piping system in which the double pipe is used requires the provision of a heat insulation, the inner pipe is used to feed the high-temperature fluid, while the outer pipe is evacuated, thereby forming the heat insulation aroud the inner pipe.
In order to form the piping system, a connection has been heretofore employed to connect one double pipe with another double pipe. However there is no satisfactory joint for connecting the double pipes together and, in fact, it has been a usual practice to form the connection by firstly connecting the inner pipes of the one and the other double pipes by means of a single joint, fitting the outer pipes onto these inner pipes at a construction field and then connecting these outer pipes by welding or binding together.
O-rings are arranged at the connected portions of the inner and outer pipes of these double pipes to form seals between the respective double pipes and between the outer pipes and atmosphere.
We made investigation into the joints for the double pipes and found that the conventional joints have many problems to be solved.
It is firstly noted that in case where lengths of the pipes as prepared are not fit to a piping system to be constructed or in case where a welding of the pipes is not allowed owing to danger of fire, it is impossible to construct the piping system.
Secondly, the conventional construction requires the steps of connecting the inner pipes and the outer pipes, separately, and arranging the packings at the connected portions of the inner and outer pipes, respectively. Accordingly, even if the piping system was arranged as required, the attaching and detaching of the pipes involve many troubles.
Furthermore, the sealing is made by arranging the separate packings at the connected portions of the inner and outer pipes, respectively, and the respective packings are subjected to deterioration at different rates from each other, owing to difference in durability of the respective packings, quality of the fluid and the other conditions. Accordingly, it is required to separately manage the sealed states of the respective connected portions of the inner and outer pipes, that is a troublesome job in actual the actual operation.
OBJECT OF THE INVENTION
It is an object of the present invention to provide a joint for connecting coaxial pipes in which the respective pipes of the one and the other coaxial pipes can be simultaneously and easily connected together and the sealing of the connected portions of the respective pipes can be simultaneously and easily made in reliable manner.
SUMMARY OF THE INVENTION
In order to solve the problems of the prior art as described above, the present invention provides a joint for connecting coaxial pipes, which includes one joint portion 2 attached to an end 4' of one of the coaxial pipes 4 and another joint portion 3 attached to an end 5' of the other coaxial pipes 5; said joint portions 2 and 3 having fluid passages 2a, 2b and 3a, 3b, respectively, which communicate with fluid passages 4a, 4b, 5a, 5b of the one and the other coaxial pipes 4 and 5 to which said joint portions are attached, respectively, said one and another joint portions 2, 3, being detachably connected together so that the fluid passages 2a, 2b of the one joint portion 2 communicate with the corresponding fluid passages 3a, 3b of the other joint portion 3, respectively, sealing means being arranged at a boundary x between said one and the other joint portions, characterized in that said sealing means is constituted by a single flat packing 25 made of metallic material having fluid passages 25a, 25b formed therein to communicate the fluid passages 2a, 2b of the one joint portion 2 with the corresponding fluid passages 3a, 3b of the other joint portion 3, respectively, and annular projections 9, 10, 19, 20 formed at the end surfaces of said one and the other joint portions 2, 3 held in contact with said metallic packing 25 to surround openings 2a', 2b', 3a', 3b' of the fluid passages of said one and the other joint portions 2, 3.
Now, the reasons why the packing, which constitutes a part of the sealing means, is made of metallic material will be explained.
Firstly, the coaxial pipe can be utilized to effect the heat exchange or the heat insulation by the action of vacuum, as described above. Under high temperature or high pressure conditions, a packing made of synthetic rubber or like material tends to cause or deflection or a flexure, so that it is not durable to use for a long time and a packing made of rubber cannot hold a vacuum exceeding a predetermined limit. Under a ultra-high vacuum exceeding the predetermined limit, the gas tends to pass through the packing or a volatile material contained in the rubber packing tends to evaporate, so that it is impossible to hold such high vacuum.
Secondly, in general the joint portions 2, 3 are made by casting metallic material, on the various reasons, such as easiness in manufacturing and machining of the packing, low cost, high strength, etc. That is, the joint portion is in general made of metallic material. Accordingly, in view of balance of rigidity between the joint and the packing, it is preferrable to make the packing 25 of metallic material or other material which has substantially same rigidity as that of the metallic material.
Thirdly, the packing 25 can be formed into a single float shape and can be formed with fluid passages, thus satisfying the requirement for easiness of processing.
Nextly, the reasons why the annular projections 9, 10, 19, 20, which constitute another part of the sealing means, will be explained.
Firstly, the sealing effect is produced by causing the joint portions 2, 3 and the single flat packing 25 of metallic material into direct contact with each other, so that it is a required to form the end surfaces 8', 16' of the joint portions 2 and 3 and the surfaces of the packing 25 with highly fine surface roughness as far as possible. The provision of the annular projections serves to decrease the contact area therebetween as far as possible, thereby decreasing the problem of fineness of the surfaces of the joint portions and the packing.
Secondly, the annular projections serve to decrease the contact area between the joint portions and the packing 25 which are pressed into contact with each other, thereby increasing the sealing force per unit contact area therebetween.
Thirdly, the annular projections serve to perfectly surround the opening portions 2a', 2b', 3a', 3b' of the fluid passages 2a, 2b, 3a, 3b when the joint portions 2 and 3 are pressed into contact with the packing 25, thereby forming independent and reliable seals between the respecteve fluid passages 2a, 2b, 3a, 3b.
OPERATION
The one joint portion 2 and the other joint portion 3 are pressed and connected together, with the single flat packing 25 of metallic material being interposed therebetween. The respective fluid passages 2a, 2b, 3a, 3b of the one and the other joint portions 2 and 3 are communicated with each other through the fluid passages 25a, 25b formed in said packing. The annular projections 9, 10, 19, 20, which are formed on the end surfaces 8', 16' of the one and the other joint portions 2 and 3 at the sides facing said packing 25, surround the opening portions 2a', 2b', 3a', 3b', and these annular projections serve to surround and seal the corresponding fluid passages 25a, 25b of said packing 25 when the joint portions are pressed and connected together, as described above. Due to the pressed contact as described above, the fluid passages 2a, 2b, 3a, 3b are sealed in completely separated state. At the sealed portion, the pressed contacts of the annular projections 9, 10, 19, 20 relative to the metallic packing 25 produce sealing forces per unit contact area which are considerably higher than the pressing force per unit area of the one and the other joint portions relative to the metallic packing 25. Accordingly, the fluids fed into the coaxial pipe 4 are carried into the coaxial pipe 5 in such manner that the fluid passing the connected inner passages 2a, 3a does not leak into the adjacent outer passages 2b, 3b while the fluid passing through the connected outer passages 2b, 3b does not leak into the adjacent inner passages 2a, 3a. Thus the fluids pass from the passages 2a, 2b of the one joint portion 2, through the passages 25a, 25b formed in the pasking and the fluid passages 3a, 3b of the other joint portion 3 to the passages 5a, 5b of the other coaxial pipe 5, respectively.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1-3 illustrate a first embodiment of the joint according to the present invention, in which:
FIG. 2 is a front view of one of the joint portions shown in FIG. 1; and
FIG. 3 is a front view of the metallic packing shown in FIG. 1.
FIGS. 4A-C illustrate a second embodiment of the joint according to the present invention, in which:
FIG. 4A is a sectional view of the joint body;
FIG. 4B is a front view of one of the joint portions shown in FIG. 4A; and
FIG. 4C is a front view of the metallic packing shown in FIG. 4A.
FIGS. 5 and 6 illustrates a third embodiment of the joint according to the present invention, and each is a sectional view showing the three-way joint.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Now the invention will be described with reference to the preferred embodiments of the invention as shown in the drawings.
FIGS. 1-3 illustrate a first embodiment of the present invention, in which the invention is particularly applied to the joint for connecting double pipes, as an example. Referring to FIG. 1, a joint body 1 for connecting the double pipes consists of one joint portion, a male joint portion, 2 and another joint portion, a female joint portion 3. The male portion 2 includes a cylindrical body 7 and a bored body 8 integrally formed with said cylindrical body. The bored body 8 has a screw thread formed on its peripheral surface and flange 6 integrally connected therewith. The bored body 8 has an inner passage 2a at its center and a plurality of outer passages 26 arranged concentrically around said inner passage at equal distanaces.
Said bored body 8 is formed at its end surface 8' with an annular projection 9 surrounding an opening and 2a' of the inner passage 2a and an annular projection 10 surrounding all of the plurality of outer passages 2b.
The one joint portion, male joint portion, 2 is connected to an end 4' of the one double pipe 4. The connection is preferrably made by inserting the inner pipe 4a into the inner passage 2a of the male joint portion 2, welding the end 4a' of the inner pipe 4a to the opening end 2a' of the inner passage 2a, and then welding the end 7' of the cylindrical body 7 of said male joint portion 2 to the outside peripheral surface of the end 4b' of the outer pipe 4b of the one double pipe. Thus, the inner pipe 4a and the outer pipe 4b of the one double pipe 4 are communicated with the inner passage 2a and the outer passage 2b of the male joint portions 2, respectively.
The other joint portion, female joint portion, 3 includes a bored body 16 having a flauge 15 formed at its end and a cylindrical body 17 integrally connected to said bored body 16. The bored body 16 has an inner passage 3a at its center and a plurality of outer passages 3b concentrically arranged around said inner passage at equal distances, in the same manner as in the male joint portion. The bored body 16 is formed, at its end surface 16' at the side of said flange 15, with an annular projection 19 surrounding an opening and 3a' of said inner passage 3a and another annular projection 20 surrounding all of the plurality of outer passages 3b. Said other joint portion, female joint portion, 3 is connected to an end 5' of said other double pipe 5. The connection may be made in the same manner as in the case of said male joint portion. The one double pipe as well as the other double pipe includes spacers 18 for holding spaces between the inner pipe 4a, 5a and the other pipe 4b, 5b, so that proper spaces are held between the inner and outer pipes even if the pipe is bent.
In order to connect the one and the other double pipes 4 and 5 together, said male joint portion 2 and said female portion 3 are so positioned that their annular projections 9, 10 and 19, 20 face each other, and these joint portions are pressed and connected with each other. The pressed connection is preferrably made by providing a threading member 22 having an inside flange 21 arranged to be engaged with the flange 15 of the female joint portion 3 and a screw thread formed on its inside wall, and threading said member 22 onto the male joint portion 2 until the forward end 22a of the thereading member 22 comes into contact with the flange 6 of the male joint portion 2.
When the male joint portion 2 is connected wtih the female joint portion 3 a single flat packing 25 made of metallic material is interposed therebetween at their boundary x. The metallic packing 25 has a plurality of passages as shown in FIG. 3. That is, the packing 25 has an inner passage 25a arranged to communicate the inner passage 2a, 3a of the one and the other joint portions 2, 3 with each other, and a plurality of outer passages 25b concentrically arranged around said inner passage to communicate the outer pipes 2b, 3b of the one and the other joint portions with each other. Now, the operation will be explained.
The inner annular projections 9, 10 formed on the end surfaces 8', 16' of the male and female joint portions 2 are pressed and sealed to the metallic packing 25 in such manner that those projections surround opening portions 25a', 25a' at both sides of the inner passage 25 of the metallic packing 25, while the outer annular projections 19, 20 are pressed and sealed to the metallic packing 25 in such manner that these projections surround all of opening portions 25b' of the plurality of outer passages 25b at both sides of the metallic packing. Accordingly, the part 31 between the communicated inner passages 9, 19 and the communicated outer passages 10, 20 is sealed, while the part 32 between the outer passages and the atmosphere is also sealed, that is, the inner passages 9, 19 and the outer passages 10, 20 are independently sealed by the single packing 25.
The single flat packing 25 arranged at right angle to the inner and outer passages 2a, 2b, 3a, 3b, which is made of metallic material, is resilient to the action of temperature and pressure, so that it does not produce deformation even if a fluid is fed at high temperature at a high pressure, and its air tight property is not adversely affected even if the pipe is held in evacusted state.
Thus the sealing effect is assured by the metallic packing 25 and the inner and outer annular projections 9, 10, 19, 20. At the sealed parts 31, 32, the contact area is decreased, so that the sealing force per unit contact area is increased. Accordingly, the inner and outer passages are reliably and properly sealed, whereby the leakage of the fluid at the connected portions is completely avoided.
FIGS. 4A-C illustrate a second embodiment, in which the invention is applied to a joint for connecting triple pipes.
In FIG. 4, a joint body 50 for connecting triple pipes includes a male joint portion 51 and a female joint portion 52, as in the first embodiment. In the second embodiment, each of the one and the other joint portions 51, 52 includes three passages for connecting the triple pipes 51, 52. As shown is FIG. 4B, the one joint portion 51 has an inner passage 51a at its center, a plurality of outer passages 51c concentrically arranged around said inner passage 51c and a plurality of intermediate passages 51b concentrically arranged betweens said inner passage and said outer passages. The other joint portion, female joint portion, 52 also includes three passages 52a 52b, 52c.
The one and the other joing portions 51, 52 are formed, at their end surfaces, with inner annular projection 54, 55 surrounding opening portions 51a' 52a' of the inner passages 51a, 52a, intermediate annular projections 56, 57 surrounding all of opening portions 51b', 52b' of the intermediate passages 51b, 52b, and outer annular projections 58, 59 surrounding opening portions 51c', 52c' of the outer passages 51c, 52c.
A single flat packing 60 disposed at the boundary of the one and the other joint portions 51, 52 has an inner passages 51a, 52a, the intermediate passages 51b, 52b and the outer passages 51c, 52c, respectively, as shown in FIG. 4C.
In the second embodiment, the male joint portion 51 and the female joint portion 52 are connected together by tightening flanges 63 and 64 of the joint portions 51 and 52 by means of bolt-nut assemblies. In the other points, the second embodiment is similar to the first embodiment.
FIGS. 5 and 6 illustrate a third embodiment of the present invention. This embodiment is designed as a three way joint. Each of joints 70 and 71 has three connecting portions to which double pipes are connected. The joint 70 has three female joint portions to which three double pipes are connected. The joint 71 has three male joint portions to which three double pipes are connected. In the other points, the third embodiment is similar to the first embodiment.
TECHNICAL EFFECT OF THE INVENTION
From the above description it will be understood that the present invention provides a joint for connecting coadial pipes which includes one joint portion connected to an end of one of the coaxial pipes and another joint portion connected to an end of the other of the coaxial pipes; said one and the other joint portions having passages which communicate with the passages of the one and the other coaxial pipes, respectively, said one and the other joint portions being detachably connected so that the passages of the one joint portion communicate with the corresponding passages of the other joint portion, respectively, sealing means being disposed at a boundary of said one and the other joint portions, characterized in that said sealing means is constituted by a single flat packing of metallic material having passages for communicating the corresponding passages of said one and the other joint portions with each other, respectively, and annular projections formed on end surfaces of said one and the other joint portions and arranged to surround opening portions of the passages of said one and the other passages of the one and the other joint portions, respectively. According to the constraction as described above, the passages of the one and the other joint portions and the passages of the metallic packing can be completely surrounded by the annular projections and the metallic packing, so that said one and the other coaxial pipes can be communiated in proper and easy manner. By the pressed and sealed connection of the metallic packing with the annular projections, high sealing force per unit contact area can be attained and said high sealing force per unit contact area is completely applied to the parts surrounding the opening portions of the passages, whereby the leakage between the passages can be completely avoided. It is not required to provide a highly fine surface roughness of the end surfaces of the joint portions and the surfaces of the metallic packing and it is possible to provide the joint at low cost.
With regard to the packing, it is possible to seal the respective passages of the single packing and the joint portions simultaneously, without using the separate sealing means by separate packings as in the conventional joint. According to this construction, the number of parts of the joint is decreased and great economy is obtained. Furthermore, the operation of mounting and demounting the joint is effected easily so that the working efficiency is improved. Since only one packing is used, the deterioration of the sealing portions of the packing can be found easily, so that the load required to manage the sealed portions can be decreased as that required in the conventional joint in which a plurality of separate packings are employed. Since the packing is made of metallic material, the packing which is arranged at right angle to the passages can withstand the high temperature and the high pressure of the fluid passing through the passages at the connection between the joint with the coaxial pipes, even when the coaxial pipes are employed as heat exchange means or vacuum heat insulation means. Thus the joint of this invention is very advantageous in utilization in the above fields. | A joint for connecting first and second co-axial pipes each having inner and outer pipes with a male joint portion receiving the pipes of one co-axial pipe and a female joint portion receiving the pipes of the other co-axial pipe. The end surfaces of the two portions have opposed protrusions which sealing engage a metallic packing. | 8 |
The U.S. Government has a paid-up license in this invention and the right in limited circumstances to require the patent owner to license others on reasonable terms as provided for by the terms of contract No. N47408-93-C-7359, awarded by the U.S. Navy.
This application is a continuation-in-part of my prior, application, entitled "Slurry Reactor", Ser. No. 08/426,566, filed Apr. 21, 1995, now U.S. Pat. No. 5,616,304, which is hereby incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to microbial reactors and to microbial reactor systems in general, and more specifically, to a mixer/contactor for a slurry, suspension or settled bed reactor system. The mixer contactor is advantageous for processes wherein contact time may be relatively long, and/or wherein minimum energy input for suspending and mixing solid particles in the slurry, suspension or settled bed is desired, for example, in the biological remediation of liquid waste streams or contaminated sludges or soils.
2. Related Art--Soil Remediation
Slurry or suspension or settled bed reactors are commonly used for processing ores, soils, and wood chips. Also, they are commonly used to effect the biological, enzymatic or chemical conversion of soluble and insoluble reactants. A slurry or suspension is a mixture of a liquid and solid particles, wherein at least a portion of the solid particles are suspended in the liquid. In a slurry or suspension reactor, a portion of the solid particles may be settled in the bottom of the reactor to form a bed.
There is a large need for conversion of contaminants, especially chemical contaminants, found in liquid waste streams, sludges and soils. These chemicals may be organic or inorganic, and hazardous or toxic. Many millions of cubic feet of soils contaminated with these chemicals exist throughout the world and are in need of remediation.
Biodegradation of many of these contaminating chemicals has been conducted. "Biodegradation" means breaking down these chemicals to less hazardous or less toxic reaction products via biological pathways using microorganisms. The microorganisms, or "microbes", may operate aerobically, microaerophylically or anaerobically, or in any combination thereof. Also, the microorganisms may operate via oxidative pathways or reductive pathways. Microorganisms include bacteria, protozoa, fungi and algae. Biodegradation of soils contaminated with chemicals is one way to remediate the soil.
Often, the remediating microorganisms operate on the soil contaminating chemicals in a slurry environment in a reactor vessel, wherein the soil is mixed with water to at least partially suspend the soil particles for intimate contact with the microorganisms. To further increase suspension, mixing and contacting, a gas, such as air in aerobic applications, for example, may be added to the reactor vessel. When the reactor vessel contains microorganisms and a slurry, it is referred to as a bioslurry reactor.
Presently, at least four bioslurry reactor systems are being commercialized for soil remediation. The first system, developed by MOTEC, Inc. of Mt. Juliet, Tenn., involves technology adapted for treatment of pesticides, PCB's, dioxin and halogenated and nonhalogenated organic compounds. While demonstrated to be effective for treating sludge, liquids and soils having high organic concentrations, the MOTEC process has been reported to be less suitable for use with inorganic-laden wastes.
The MOTEC technology, which is a sequential process, is also referred to as liquid solid contact digestion (LSCD). The system involves two to three tank digestors which are aerated using air spargers and are agitated using turbine mixers. Alternatively, this technology may be adapted, by use of high shear propeller mixers, to enhance aerobic biological degradation in lagoons.
The second technology, developed by Detox Industries, Inc. of Sugarland, Tex., is intended for use in treating chlordane, myrex, oil, phenolics, polycyclic aromatic hydrocarbons, creosote, pentachlorophenol (PCP) and polychlorinated biphenyls (PCB's). The Detox system includes an open-topped reaction tank or on-site created lagoon that utilizes a synthetic liner. The tank is adapted to retain a slurry and is fitted with air distributors.
Another bioslurry reactor, consisting of several agitated and aerated vessels, has been used in a pesticide spill application by ECOVA of Redmund, Wash.
The MOTEC, Detox, and ECOVA systems described above are operated in batch mode. After the placement of contaminated soil and water into the reactor vessel, the vessel is aerated until a desired residual contaminant level is reached, and then the supernatant water is usually recycled and the slurry is discharged. Due to the ongoing aeration in these systems, many volatile organic substances are not biodegraded but rather are air-stripped. Some systems treat these air-stripped volatiles in a carbon adsorption filter whereas other systems simply discharge them to the atmosphere.
A fourth system, known as the EIMCO Biolift® system, utilizes a bioreactor that is a tank having a bottom, upstanding walls fixedly mounted thereon and a sealed top or cover, and which is adapted to receive and contain a slurry. The tank is fitted with a mechanical mixing means that operates to effectuate agitation and suspension of the solid particles within the slurry housed within the tank. An air supply operates to provide oxygen, which is a necessary component of the biooxidation reaction taking place within the bioreactor. The air supply also is configured to provide suspension of the particulates within the slurry liquid housed within the tank. In addition, an air lift is provided for recirculating particulates which may have settled out of the slurry. The Biolift® system may be operated in continuous mode by using a screening device and exit conduit located near the top inside the tank to draw off treated water and excess particulate matter.
Considerable literature is available describing slurry reactors for municipal and farm sewage digestion, but the total solids for these applications are usually below 10 wt %. The density of sewage sludges is much closer to the density of water than is the density of soil, and therefore the mixing method and design of these sewage sludge stirred reactors can be significantly different than that of soil-slurry reactors. Many sewage digester designs are unstirred, and the predominant mixing mechanism is the CO 2 and CH 4 gas generated in the reactor. The mixing occurs as these gas bubbles rise through the slurry. Propeller type mixers are sometimes added for more thorough mixing and to try to maintain the solids in suspension. The current design of most soil-slurry reactors is to finely pulverize the material and try to keep it in suspension with significant power input to shaft stirrers, aerators, recirculation pumps or a combination of these methods. The alternative approach is to not mix at all or to mix only occasionally. With the extended residence time required for most biodegradation, there is probably no need for a high shear or complete suspension agitation, especially for an anaerobic design.
In aerobic soil-slurry reactors it is difficult to maintain high oxygen concentrations due to the tendency for gas bubbles to coalesce. Also, since the reactors are usually low in profile, there is a very short liquid-gas contact time and a small surface area to volume ratio of the bubbles. Mechanical agitation is usually required to disperse gas bubbles and give smaller gas bubbles, but as the solids concentration increases the agitation effect decreases.
Common to all hazardous waste treatment systems utilizing microorganism activity is the requirement of providing an adequate supply of nutrients to the microorganisms. This provision allows biomass growth and facilitates the occurrence of biochemical reactions. Various approaches have been used to optimize bioactivity level in reactor vessels. In those systems wherein a multiplicity of connected reactor vessels have been suggested, e.g. cascade systems, a common problem is the retention and maintenance of biomass in a given reactor as effluent from the reactor is directed to the next reactor.
The clean-up of hazardous waste sites requires innovative approaches that are cost effective. Biological systems can play an important role in soil bioremediation, as they have in the field of wastewater treatment. In order to be cost effective in contaminated soil treatment, however, bioreactor vessels and processes are needed that can handle high solids concentrations and large throughput volumes with a minimum of input and/or operating energy.
3. Related Art--Wastewater Remediation
Dissolved organic matter and suspended solids are often removed from wastewaters by a combination of biodegradation and filtration. Conventional designs for microbial water treatment processes are based on suspended microorganisms to degrade organic matter in wastewaters. These activated sludge processes are in wide usage, but they are not efficient in removing waste materials, and they require large facilities. Attached-growth systems, with bioreactors packed with inert media on which microorganisms can attach and grow, are much more efficient than suspended growth systems.
A variety of arrangements have been used to clean wastewaters using biological treatment and filtration. One arrangement has been bioreactors in line with sedimentation tanks and filters. The reactor can be as simple as a tank where air is injected and aerobic bacteria are grown on inert carriers such as plastics and sand. U.S. Pat. No. 5,007,620 discloses a bioreactor equipped with a sweeping means adapted for sweeping and scouring the bottom of the bioreactor. Stationary diffusers are used to aerate the bioreactor. By these means, an aerated slurry can be maintained by means of mechanical agitation and aeration.
Alternatively, a bioreactor can be operated anaerobically in processes such as anaerobic digestion and denitrification. U.S. Pat. No. 3,970,555 discloses a method for backwashing a filter by injecting a fluid, such as air or water, to dislodge gas bubbles trapped in a filter bed. Such backwashing also removes solids clogging the filter bed.
Bioreactors operated with inert media for supporting microbial growth, are termed "biofilters", and have been operated with a stationary filter medium or a movable filter medium. The filter medium typically consists of plastic materials or inorganic materials such as sand. Stationary filter media must be periodically cleaned by a reversed-flow washing, termed "backwashing". Backwashing, especially when done with injected water and air, can effectively clean the medium. However, the backwash fluids must be collected and treated. Also, the biofilter must be periodically removed from service in order to do the backwashing.
Fluidized bioreactors have been developed for continuous operation without backwashing (U.S. Pat. No. 5,007,620). However, such bioreactors require continuous agitation with high energy consumption. In addition, fluidized bioreactors cannot clean wastewater by filtration.
SUMMARY OF THE INVENTION
The instant invention is a slurry mixer/contactor for a slurry, suspension or settled bed reactor system. The mixer/contactor is particularly well-suited for the biological remediation of liquid waste streams or contaminated sludges or soils. The reactor system having the mixer/contactor of this invention may operate with microorganisms living in the reactor aerobically or anaerobically. Also, the reactor system may operate with microorganisms in the reactor using oxidative or reductive pathways to biodegrade contaminants. To further increase activity in the bioreactor, additional ingredients, including solids, liquids or gases, may be added to the slurry, suspension or settled bed in the reactor.
The reactor having the mixer/contactor in one embodiment is an upright generally cylindrical vessel with a flat bottom and a covered top. In the inside of the vessel, preferably along the cylinder centerline, is a vertical conduit, also called a supply conduit, extending from near the top to near the bottom. At the bottom of the vertical conduit is the inlet to at least one generally horizontal, stirrer blade in fluid connection with the vertical conduit. The stirrer blade has outlet openings in it or on it so fluid may pass therethrough. The stirrer blade may rotate around the vertical conduit if the conduit is fixed, or the conduit, with the stirrer blade fixed to it, may rotate around in the vessel. In any event, the rotation of the stirrer blade is caused or made easier by the hydraulic forces of fluid flowing out from the stirrer blade. This rotation may be caused or made easier by a fluidization effect, by a jet propulsion effect, or both. This way, rotation of the stirrer blade may be created or eased near the bottom of the vessel, enhancing mixing of the microorganisms with the sludge or soil in the slurry, suspension or settled bed in the vessel, without unnecessarily damaging the microorganisms and without having to fluidize the complete vessel contents. Also, this way liquid and/or slurry from near the top of the reactor may be re-distributed into the sediment near the bottom of the reactor for fresh re-contact and further desorption and reaction of contaminants from the sediment to permit further biodegradation.
In a preferred embodiment, the bioreactor vessel has a water recycle outlet port and a gas recycle outlet port. At the water recycle outlet port, which is below the fill line for the reactor, is a water recycle outlet conduit leading to the inlet of a water recycle pump. The pump delivers recycled water back to the bioreactor vessel through a water inlet conduit connected to the vessel at a water recycle inlet port. Preferably, the water inlet port is connected to the vertical conduit in the center of the vessel, and the flow of recycled water helps to provide the hydraulic forces for fluidizing the sediment in the immediate vicinity of the blade and/or the jet propulsion that results in rotation of the stirrer blade.
At the gas recycle outlet port of the bioreactor vessel is a gas recycle outlet conduit leading to the inlet of a gas recycle pump or compressor. The compressor may deliver recycled gas and/or fresh gas to the bioreactor vessel through a gas inlet conduit connected to the vessel at a gas inlet port, or connected to the water inlet conduit. This way, water and gas from the bioreactor vessel may be recycled and provided to the vertical conduit to help create rotation of the stirrer blade, and better mixing and contacting of the slurry or suspension and the microorganisms in the bioreactor vessel.
Preferably, the mixer/contactor is one, generally horizontal blade in fluid connection with the vertical conduit. The blade has outlet openings at or near its leading edge so that fluid passing through the vertical conduit and to the blade may pass from the blade through the openings. This way, a fluidization zone is created in the slurry, suspension or settled bed of solid particles, in the region of the openings at or near the leading edge of the blade. By "leading edge" of the blade is meant the front edge or side of the blade relative to the direction of rotation of the blade. By "trailing edge" is meant the back edge or side of the blade relative to rotation. More than one blade may be used, and blades at various depths in the reactor may also be used. When a plurality of blades is used, they may rotate independently of, or together as a unit with, the other blade(s).
The fluidization zone created by the flow of fluid from the outlet openings in the blade has less density than the rest of the slurry, suspension or settled bed throughout the reactor. Therefore, any generally horizontal force on the blade will tend to cause it to rotate into the fluidization zone. This horizontal force on the blade may be created by a propulsion jet at the trailing edge of the blade. Or, this horizontal force may be created by the horizontal component of the weight vector from settling sediment on a rear, downwardly sloping portion of the blade as the sediment descends from a fluidized state to a settled state at the trailing edge of the blade. Or, this horizontal force may be created by the input from an external power source, like an electric motor, for example, connected to and rotating the vessel's vertical conduit. Therefore, the blade rotates, or its rotation in the reactor vessel is made easier, due to the hydraulic forces of fluid flowing out from the stirrer blade.
This invention also relates to the use of a single bioreactor to achieve both biological degradation and the filtration of suspended solids. The mixing/contacting blade intermittently suspends the filtration medium as the blade rotates through the medium to efficiently backwash and clean it.
One objective of this invention is to provide an efficient biofilter equipped with a filter bed through which movable blades can be propelled by the injection of fluids, such as air and water. Thereby, the filter bed can be intermittently suspended and efficiently cleaned of trapped solids and gases. Another objective is to provide a biofilter capable of both microbial degradation of wastewater contaminants and contaminant removal by filtration.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial side view of one embodiment of the reactor of this invention.
FIG. 2 is a schematic, cross-sectional view of the reactor depicted in FIG. 1, showing some of the reactor's internal structure.
FIG. 3 is a schematic, top cross-sectional view of the reactor depicted in FIGS. 1 and 2.
FIG. 4 is a cross-sectional side view of the mixer/contactor blade of the invention, from the line 4--4 in FIG. 2.
FIG. 5 is a schematic, cross-sectional view of the reactor depicted in FIGS. 1-4, showing the reactor's additional external equipment.
FIG. 6 is a schematic, partial detail isometric view of one embodiment of the mixer/contactor blade of the invention, showing the fluid flow lines out from it during operation.
FIG. 7 is a view as in FIG. 6, but of another embodiment of the mixer/contactor blade.
FIG. 8 is a view as in FIGS. 6 and 7, but of yet another embodiment of the mixer/contactor blade.
FIG. 9 is a partial, cross-sectional side view from line 9--9 of the mixer/contactor blade depicted in FIG. 8, showing the fluidization effect and the propulsion effect in the settled bed around the blade.
FIG. 10 is a schematic, partial side view of another embodiment of the invention with a plurality of mixer/contactor blades at different depths in the reactor.
FIG. 11A is a schematic, side cross-sectional view of another embodiment of a reactor of the invention with a submersible pump in it.
FIGS. 11B and 11C are schematic detail side and top views, respectively, of reactor internals for the embodiment of FIG. 11A.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the Figures, there are shown several, but not the only, embodiments of the reactor 10 having the mixer/contactor blade of this invention. Referring to FIG. 1, reactor 10 is an upright, generally cylindrical vessel 11 with a flat bottom 12 and a conical top 13. In conical top 13 is optional fill port 14 and gas recycle outlet ports 15 and 15(A). Conical top 13 fits within annular water seal 16, which has water seal overflow port 17. In the side wall of cylindrical vessel 11 are water recycle outlet port 18, water recycle inlet port 19, drain port 20, viewing window 21, and sample ports 22, 22A, 22B, and 22C.
Referring to FIG. 2, reactor 10 has water seal 16 and a vertical conduit 23 supported along the centerline of vessel 11 by bracing 24 and 24A. Vertical conduit 23 terminates near the bottom 12 of vessel 11 at "T" fluid connection 25. "T" connection 25 is rotatably supported on bottom 12 by spindle bearing 26. At the horizontal termini of "T" connection 25 are hollow stirrer blades 27 and 27A. The blades 27 and 27A are in fluid connection with vertical conduit 23, and have in them openings 28, 28A, 28B, 28C, and 28D.
Referring to FIG. 3, reactor 10 has cylindrical vessel 11 with water seal 16, and bracing 24, 24A, 24B, and 24C for supporting vertical conduit 23. At the bottom end of vertical conduit 23 are horizontal stirrer blades 27 and 27A. In this pictured embodiment, vertical conduit 23 rotates, and it is rotatably supported near its top in the bracing by hub bearing 29.
Referring to FIG. 4, stirrer blade 27A has a generally triangular cross-sectional shape. The circular "T" connection 25 inlet to the blade 27A is indicated at 30. At several locations along the length of the blade 27A, bolts 31 with leading edge retainers 32 and 32A are provided to stiffen and stabilize blade 27A. A fluid flow path or gap 32B is provided at several locations along the leading length of the blade 27A between it and edge retainer 32A. This way, fluid can exit the blade 27A at gaps 32B and fluidize the sediment bed, and propel the blade around in the reactor.
Referring to FIG. 5, reactor 10 has gas recycle outlet port 15 and gas recycle outlet conduit 33 leading to air pump or compressor 34. In recycle outlet conduit 33 is optional 4-way gas valve 35. Air pump 34 discharges compressed recycle gas into gas inlet conduit 36, which is connected and discharges into water recycle inlet conduit 37. Recycle inlet conduit 37 is connected on its first end to water pump 38, and on its second end to water recycle inlet port 19. Inside vessel 11, interior conduit 39 is connected on its first end to inlet port 19, and on its second end to the first end of rotating swivel connection 40. Swivel connection 40 is supported by hub 29 as shown in FIG. 3, and connected on its second end to vertical conduit 23. Swivel connection 40 permits interior conduit 39 to be fixably connected to inlet port 19 and swivel connection 40, and, at the same time, permits vertical conduit 23 to be rotatably connected to swivel connection 40. This way, vertical conduit 23, "T" connection 25 and stirrer blades 27 and 27A may rotate inside vessel 11.
During operation, the slurry or suspension inside vessel 11 is maintained above the level of water recycle outlet port 18. Recycle outlet port 18 is equipped on the inside of vessel 11 with an outlet screen 41. Screen 41 prevents the solid particles in the slurry or suspension greater than the size of the screen openings from exiting the vessel 11. Water recycle, however, is permitted to exit outlet port 18, and travels via water recycle outlet conduit 42 to the inlet of water pump 38. The discharge of water pump 38 travels via inlet conduit 37, inlet port 19, interior conduit 39, swivel connection 40, vertical conduit 23, "T" connection 25, "T" connection inlet 30, and stirrer blades 27 or 27A back into the interior of vessel 11 near its bottom. This way, the hydraulic forces of the water recycle rotates, or makes easier the rotation of stirrer blades 27 and 27A, enhancing mixing of the microorganisms with the sludge or settled sediment near the bottom of vessel 11 without unnecessarily damaging the microorganisms. This way, the reactor may be operated with, for example, soil slurries at greater than 50 wt % total solids.
Preferably, the bioreactor has four basic modes of operation. In these four modes, the water and air pumps are controlled by a repeat cycle timer that allows either or both pumps to be operated intermittently or continuously.
First Mode. In the first mode of operation, water is recirculated through the blade which fluidizes the slurry, suspension or settled bed in front of the blade and propels the stirrer through the slurry, bringing fresh liquid in contact with the soil for rapid mixing. The water exiting the nozzle propels the stirrer and also brings solids up into suspension from the bottom and rapidly mixes them. If the circulation is for a short time, the solids are mixed but not so much that they are fully suspended and sucked into the recycle outlet.
Second Mode. In the second mode of operation, the air pump can be added to the operation, allowing very efficient aeration for aerobic reactions, and increasing vertical mixing with the rising bubbles. Since the water and air are both under pressure, the amount of oxygen dissolved in the water can be increased considerably above saturation at atmospheric pressure. For high biological oxygen demand (BOD) systems, this will allow significantly higher oxygen mass transfer rates than for a normally bubbled and stirred reactor. If foaming is a problem with a specific slurry or suspension, the addition of air can be intermittent, with the foam subsiding when air is not being added.
One way to add air to the operation is to provide a bubbleless oxygenation tube at the discharge of the air pump or compressor 34. For example, with three-way valve 60 in gas inlet conduit 36 and with bubbleless oxygenator 61 in recycle inlet conduit 37, air under pressure is routed through oxygenator 61 into reactor 11. This way, foaming in reactor 11 may be minimized. Bubbleless oxygenator tubes are available from, for example, Membran Corp., Minneapolis, Minn., U.S.A.
Third Mode. In the third mode of operation, the air pump will pump headspace gases as recycle gases into the water recycle flow, thereby increasing the mixing rates and allowing more complete degradation of volatile compounds in the slurry. This will also increase vertical mixing in anaerobic operations and reintroduce volatiles into the slurry for further degradation.
Fourth Mode. The fourth mode of operation is a combination of the above modes; the modes can be operated on an intermittent basis to reduce operational costs or to maintain microaerophilic conditions. Also, by switching between the second and third modes with the 4-way valve 35, there will be no excess aeration or volatiles lost. This system can be easily interfaced with a computer for active control of the operating mode.
The reactor has the additional benefits of being an intermittently cleaned sand filter with very high biomass retention. In fact, the bioreactor may be used as an intermittently backwashed sand filter without substantial biodegradation. This allows for very efficient space utilization and exceptionally low effluent BOD and suspended solids concentration for a single-pass aerobic or anaerobic reactor. This system can also operate as a sequencing batch reactor, and/or as a mixed mode reactor with both aerobic and anaerobic operations.
For continuous operations, fresh wastewater or soil slurry may be added to the water recycle outlet conduit 42, and excess treated water removed from drain port 20 at the bottom of the reactor. This may be done without significant loss of the sand or the biomass from the interior of the reactor if a suitable screen is used inside drain port 20. Depending on the source of fresh waste-water, it may be supplied directly to the blade through vertical conduit 23, and not through the recycle pump.
This novel slurry reactor is an intermittently mixed reactor that has the capability of intermittently fluidizing over 50% wt/wt sand with complete mixing occurring every minute in a 200 gallon pilot-scale reactor. The sand in the reactor can also be operated very efficiently as an anaerobic expended bed bioreactor with intermittent mixing (<5% of the time) and still have very complete and thorough mixing. High biomass retention allows for an old sludge age and very high degradation rates. In addition to providing for an attachment surface for the retention of biomass, the sand layer acts as sand filter as the water is removed from the bottom of the reactor. Any suspended material, including biomass, is retained by the sand filter therefore allowing very high biomass densities to be maintained, with resulting very high activity. As the mixing blade moves through the sand bed it fluidizes the sand near the blade and keeps the biomass from plugging the sand or the screened outlet. The flocculent biomass goes into suspension and is fluidized, while the attached biomass has fresh liquid brought into contact with the biofilm. This enables a very high rate of degradation in a small volume. The backwashing cycle may be controlled by monitoring the pressure drop across the settled bed or the flow rate out of the drain port. A pressure drop above the set-point, or a flow rate below the set-point, would initiate the backwash cycle.
When biomass wasting is desired or required, the reactor can be fully fluidized and the recycle can be directed to a suitable container for a settling basin. An alternate wasting method is to drain some of the liquid away before directing the recycle to a suitable settling basin. This wasting cycle can be incorporated into a weekly operation, or it could possibly be an automatic part of the normal cycling of the reactor. The intermittent mixing of only about 5% of the time consumes very little energy, but has significant advantages in both the operation and efficiency of the degradation. The range of wastewater strengths as influent can vary from about 300 to greater than 30,000 mg/l COD depending on the final design of the system.
An embodiment could also include more than one reactor in series or parallel with effluent from either below the sand level or from above the sand level from the first reactor (which would likely be operating in an anaerobic mode) to a second reactor which could be operating aerobically and the effluent from the second reactor could be moved from below the sand level for very good effluent quality. By having the second reactor actually be two reactors in parallel, then these two reactors could operate in alternating batch mode which would enable effluent to be drawn from one of the two reactors that had just completed a settling mode. This embodiment would not require the removal of the water from below the sand but it would not preclude it either. One of the series of reactors could be setup for a denitrification process as is well known in the industry.
Additionally, by having one of the reactors operating with an aerobic slurry phase and a blade in the upper layer of the sand to fluidize and clean only the upper region of sand, the lower region of sand could be anaerobic for denitrification to occur. Swivels of some companies allow two or more isolated flows to occur so the liquid from the aerobic region would only fluidize the upper sand and liquid from the anaerobic portion could be used to fluidize the lower portion. An alternate method to have two different redox states in the sand regions is to have a two speed pump or other flow control means on the recycle flow so that at a low flow only the upper sand is fluidized but at higher flow rates the complete bed is mixed.
There are also times that the influent water flow will be great enough that a recycle pump is not necessary and the influent flow can go through the blade and nozzles to fluidize the reactor contents and sand bed if a sand bed is part of the system.
Referring to FIG. 6, triangular stirrer blade 43 has fluidization openings 44 in its front, or leading, side, and jet propulsion opening 45 in its back, or trailing, side. When fluid is directed into blade 43 from vertical conduit 23, "T" connector 25 and "T" connector inlet 30, the fluid flows out from fluidization openings 44 and jet propulsion opening 45.
Referring to FIG. 7, round stirrer blade 46 has fluidization openings 47 and 47A which are the outlets of relatively short conduits welded parallel to the leading edge of blade 46. The conduit 49 is very short and its opening 47 is near vertical conduit 23. The conduit 50 is longer and its opening 47A is near the middle of stirrer blade 46. Both openings 47 and 47A are pointed parallel to the leading edge of blade 46. This way, the fluidization zone created by fluid flowing out of openings 47 and 47A is at or near the leading edge of blade 46. Also, round stirrer blade 46 has jet propulsion opening 48 in its back, or trailing, side.
Referring to FIG. 8, round stirrer blade 51 has fluidization openings 52 in its front side, and jet propulsion opening 53 in its back side. When fluid is directed into blade 51 from vertical conduit 23, "T" connector 25 and "T" connector inlet 30, the fluid flows out from fluidization openings 52 and jet propulsion opening 53.
Referring to FIG. 9, the outflow of fluid from fluidization openings 52 in stirrer blade 51 creates a zone 54 of fluidized sediment in the region in front of blade 51 near the openings 52. Zone 54 has relatively less density than non-fluidized zone 55 that exists behind blade 51 and elsewhere in the sediment throughout the reactor. Therefore, the tendency is for blade 51 to rotate in the direction of fluidized zone 54 whenever any rotational force is exerted on blade 51, that is, in the direction of the arrow in FIGS. 6-8. This way, blade 51 rotates around the bottom of reactor 10, fluidizing a relatively small segment of the sediment bed before it as it rotates. Also this way, the solid particles that make up the sediment bed are periodically mixed and recontacted with fresh feed or recycle flowing out from openings 52, enhancing desorption of contaminants from them, and biodegradation.
FIGS. 4, 6-9 illustrate stirrer blades that comprise an elongated member which is generally hollow and that have fluid outlet openings at or near their leading sides. FIGS. 4, 6, 8 and 9 illustrate stirrer blades in which the leading side outlet openings comprise apertures located in the main, elongated hollow stirring member. FIG. 7, on the other hand, illustrates a stirrer blade with a leading side comprising horizontal conduit members, attached to the main member, for the outlet openings. Especially in embodiments such as FIG. 7, in which the outlet fluid path is through conduits or other hollow apparatus rather than apertures in the main member, the main, elongated stirring member optionally may be solid rather than hollow, especially if no trailing side jet is desired.
Referring to FIG. 10, reactor 10 has several vertical conduits 56A, 56B and 56C, and several rotary unions 57A, 57B and 57C connecting the vertical conduits. Each rotary union has a horizontally-extending hollow stirrer blade, 58A, 58B and 58C, respectively. Interior conduit 39 is connected to the top of rotary union 57A. The bottom of rotary union 57C is rotatably supported by spindle bearing 26. The blades 58A, 58B and 58C are in fluid connection with the respective rotary unions 57A, 57B and 57C, which in turn are in fluid connection with the respective vertical conduits 56A, 56B and 56C. Depending on the type of rotary union selected, blades 58A, 58B, and 58C may rotate independently of one another, in mixed combination of independent or dependent rotation, or all together as a unit. This way, the blades may rotate in the settled bed at one speed, and in the slurry or suspension above the settled bed at a different speed. In blade 58A it can be seen that small "T" fittings may be added to the fluid outlet openings to better control the direction of fluid flow from the openings. The T-fittings may be at -45° to +45° from parallel to the blade.
Referring to FIGS. 11A, 11B, and 11C, they show another scheme for mounting the blade assembly inside an inexpensive tank (i.e. polyethylene 8-12 ft diameter, by 8-14 ft high). The center hatched area is a cylindrical, screened region in which may be located submersible pump. A wiper/scraper/brush may be mounted on the central conduit for rotating around with the blade to clean the screen The pillow blocks (with split halves) may be both above the water level for accessibility and ease in removing the blade if needed and for trouble free service. The lower, left outlet pipe is for removing water as filtered water, from below the sand bed through the slotted screen (available from Cook Screen Company and others). The lower right pipe could be for water coming into the reactor and also for wasting solids (but not the sand) by stopping the mixing and allowing solids to settle and then opening or pumping out of that port. The upper right pipe could be a fill port or an overflow port if it were higher. The top view shows the upper two truss braces are welded together with the lower one bolted to it after inserting everything into the tank through the 3 foot diameter access port. The cycle time may be timer-controlled, for example, or it may be controlled by the pressure drop across the sand bed, or it may be controlled by a flow control valve on the outlet pipe from drain port 20. By having a pump on the outlet pipe, a much higher flow rate could pass through the sand and the reactor would operate more as a filter as a bioreactor with a very short retention time.
The stirrer or mixer/contactor blade of this invention, then, may be practiced in several embodiments. The size and shape of the blade may be varied, as long as outlet openings may be placed at or near its leading edge, and as long as the trailing side of the blade is dissimilar from the leading side. The trailing side may be dissimilar from the leading side in that the number and/or type of fluid outlet openings are different from those of the leading side. For example, the trailing side may have one fluid outlet while the leading side has a plurality of outlets, as shown in FIG. 7. Or, the trailing side may have no fluid outlets, while the leading side does have outlets. Also, the trailing side may be dissimilar from the leading side in its shape or profile. Preferably, the blade has a shape which encourages sediment settling on it to be directed towards the trailing edge of the blade as the sediment continues to descend. With such a shape, the horizontal component of the weight vector from the settling sediment pushes the blade forward into the fluidization zone at the front of the blade. For example, the blade may be shaped to have a side profile similar in general shape to an airplane wing. When the blade is shaped appropriately, adequate forward horizontal force is supplied by the settling sediment, making optional the propulsion jet opening(s) at the trailing edge of the blade.
So, the selection or design of a particular blade for use in the invention depends upon many factors, including: the type of liquid and the size and density distributions of the solid particles; the rate of the biodegradation reactions; etc. Therefore, a preferred blade design depends upon many factors like these.
It is also apparent that adding a motorized device to assure rotation of the blade would fall within the scope of this invention. One main aspect of this invention is to provide energy to fluidize material in the immediate vicinity of the blade and then move this fluidized zone around the complete reactor. Whether or not the rotational force comes solely from the hydraulic forces or also from a mechanical torque provider is also within the scope of this invention. In many embodiments of the invention, a motorized drive means is not needed to power the blade(s). Optionally, a motor, or other braking means may be added to slow, or otherwise control the speed of the rotating blade(s).
It is also apparent that this described reactor and process is suitable for high efficiency mixing of a very wide variety of materials with low energy requirements, including gas, liquid or solid or any combination thereof, for a wide variety of processes, including physical, biological, catalytic or chemical processes.
Although this invention has been described above with reference to particular means, materials and embodiments, it is to be understood that the invention is not limited to these disclosed particulars, but extends instead to all equivalents within the scope of the following claims. | Embodiments of a remediation reactor and mixer/contactor blade for the reactor are shown and described, the reactor being for containing a liquid slurry, suspension or settled bed of solid particles containing microorganisms. Inside the vessel is a supply conduit and at least one generally horizontal stirrer blade in fluid connection with the supply conduit. The stirrer blade is a mixer/contactor which has a leading side having openings through which fluid may pass. The stirrer blade rotates in the vessel, and this rotation is made easier by the hydraulic forces of fluid flowing out from the stirrer blade. The flowing fluid creates a fluidization zone in the slurry, suspension or settled bed at or near the leading edge of the stirrer blade. The fluidization zone is less dense than the rest of the sediment bed, and the stirrer blade tends to rotate into the fluidization zone. This way, controlled rotation of the stirrer blade may be created near the bottom of the vessel, enhancing mixing of the microorganisms with the slurry, suspension or settled bed in the vessel, without unnecessarily damaging the microorganisms, especially when the flowing fluid contains contaminants which are nutrients for the microorganisms. Also, shown and described is a vessel which incorporates a mixing blade through which a gas and/or a liquid is recirculated. The mixing blade is rotated through a sand layer or other settled bed of solid particles, which acts as a medium supporting microbial growth and/or as a filter to remove particulate matter from the vessel effluent which is drawn off from below the settled bed layer. Fluid recirculation aids in the fluidization of the filter medium and allows for intermittent operation with a significant reduction in energy and operating costs. The vessel may be operated as an aerobic bioreactor by recirculating air or as an anaerobic bioreactor by recirculating an inert gas. | 2 |
REFERENCE TO RELATED APPLICATION
[0001] This application is related to U.S. Pat. No. 6,657,894, issued 2 Dec. 2003, entitled “Apparatus and Method for Programming Virtual Ground Nonvolatile Memory Cell Array Without Disturbing Adjacent Cells.”
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present technology relates to nonvolatile memory cells, and in particular to nonvolatile memory cells subject to the program disturb effect.
[0004] 2. Description of Related Art
[0005] The program operation of a nonvolatile memory cell is complicated by the program disturb effect. Programming refers to adding charge to, or removing charge from, selected memory cells of a memory array, unlike the indiscriminate erase operation which resets typically an entire sector of memory cells to the same charge storage state. The invention encompasses both products and methods where programming refers to making the net charge stored in the charge trapping structure more negative or more positive, and products and methods where erasing refers to making the net charge stored in the charge trapping structure more negative or more positive. In the program disturb effect, programming of a selected cell leads to unwanted programming of unselected memory cells adjacent to the selected cell. In particular, the program disturb effect leads to unwanted programming of memory cells that are: 1) located in columns adjacent to the column including the selected cell and 2) connected to the selected row line (the word line providing a gate voltage to the selected cell). The integrity of the memory array is adversely affected by these problems.
[0006] A prior approach of addressing the read disturb effect alleviated the conditions giving rise to the unwanted programming of unselected memory cells. Unselected memory cells are programmed because of an unwanted voltage difference across the bit lines connected to the unselected memory cells which are in the column adjacent to the column including the selected cell. For example, if a bit line voltage is raised to program a memory cell positioned on one side of the bit line, the program disturb effect tends to program the adjacent memory cell on the other side of the bit line as well. The unwanted programming of unselected memory cells is prevented by decreasing the magnitude of the unwanted voltage difference across the bit lines connected to the unselected memory cells which are in the column adjacent to the column including the selected cell. For example, of the two bit lines that are used for accessing the column adjacent to the column including the memory cell selected to be programmed, when a program voltage is applied to one of those two bit lines to program the selected memory cell, the voltage of the other bit line is changed to decrease the unwanted voltage difference.
[0007] This prevention mechanism masks the underlying tendency towards the program disturb effect, but does not prevent the underlying tendency leading to the program disturb effect. Because the program disturb effect is an intrinsic effect of many programming mechanisms, it would be advantageous to somehow take advantage of the program disturb effect, rather than simply applying voltages to other bit lines for the sole purpose of counteracting the voltage conditions that give rise to the program disturb effect.
SUMMARY OF THE INVENTION
[0008] Various embodiments of the present invention are directed to a nonvolatile memory and a method for programming the memory. Rather than applying voltage settings to the bit lines only to counteract the program disturb effect, various embodiments take advantage of the program disturb effect to program nonvolatile memory in units of at least two memory cells.
[0009] A common architecture of a nonvolatile memory array arranges the memory cells in row and columns. Each of the memory cells includes a body; two current terminals in the body, a bottom dielectric, a charge trapping structure having parts corresponding to the each current terminal (and each part having a charge storage state), a top dielectric.
[0010] Word lines control access to the row of the nonvolatile memory array. Each word line provides a gate voltage to the top dielectric of the memory cells in a particular row of memory cells. Bit lines access the columns of memory cells via the current terminals of the memory cells.
[0011] At least three particular bit lines access memory cells are arranged with respect to the memory cells in at least two columns of the memory array as follows. A first bit line accesses a first current terminal of memory cells in the first column and the second column. A second bit line accesses a second current terminal of memory cells in the first column. A third bit line accesses the second current terminal of memory cells in is the second column. In this fashion, the first current terminals of adjacent memory cells in neighboring columns are accessed by a same bit line, and the second current terminals of these adjacent memory cells in neighboring columns are accessed by different bit lines.
[0012] In one embodiment, the program command is to add charge to a memory cell in the first column and to a memory cell in the second column. A voltage is applied to the word line that supplies the gate voltage to at least the memory cell in the first column and to the memory cell in the second column. The gate voltage is sufficient to move energetic charge from the body of memory cells across the bottom dielectric into the charge trapping structure. For example, if energetic charge had been induced in the body of a memory cell by current mechanisms (for example, such as CHISEL, CHE, Fowler-Nordheim tunneling, band-to-band hot hole tunneling) then the gate voltage is sufficient to move this energetic charge. A voltage is applied to the first bit line, which accesses memory cells in at least the first column and second column to be programmed. This voltage is sufficient to induce the energetic charge (for example, via CHISEL, CHE, Fowler-Nordheim tunneling, band-to-band hot hole tunneling) in the bodies of memory cells that have at least a sufficient voltage difference between their current terminals. Finally, a voltage setting is applied to the second and third bit lines, which are the remaining bit lines that access memory cells in at least the first column and second column to be programmed. The voltage setting can cause the same voltage to be applied to the second and third bit lines for simplicity, or different voltages on the second and third bit lines for flexibility. This voltage setting causes at least a sufficient voltage difference between the current terminals of memory cells in at least the first column and the second column to induce the energetic charge (for example, via CHISEL, CHE, Fowler-Nordheim tunneling, band-to-band hot hole tunneling) in the bodies of memory cells in the memory cells. Because of this sufficient voltage difference and the successful inducement of energetic charge in the bodies of the memory cells, the gate voltage and the voltage applied to the first bit line add charge to the memory cells.
[0013] In another embodiment, the program command is to not add charge to a memory cell in the first column and to a memory cell in the second column. Rather than applying voltage setting to the second and third bit lines that causes at least a sufficient voltage difference between the current terminals of memory cells in at least the first column and the second column to induce the energetic charge in the bodies of memory cells, the voltage setting causes an insufficient voltage difference between the current terminals of memory cells in the first column and the second column that fails to induce the energetic charge in the bodies of the memory cells. Because of this insufficient voltage difference and the failure to induce energetic charge in the bodies of the memory cells, the gate voltage and the voltage applied to the first bit line do not add charge to the memory cells.
[0014] In another embodiment, the voltage setting is applied to the second and third bit lines depending on the program command as follows:
[0015] A) if the program command is to add charge to the charge trapping structure of the memory cells in the first and second columns, applying the voltage setting to the second and third bit lines to cause at least the sufficient voltage difference between the current terminals of the memory cells to induce the energetic charge in the bodies of the first and second columns of memory cells;
[0016] B) if the program command is to not add charge to the charge trapping structure of the memory cells in the first and second columns, applying the voltage setting to the second and third bit lines to cause an insufficient voltage difference between the current terminals failing to induce the energetic charge in the bodies of the first and second columns of memory cells;
[0017] C) if the program command is to add charge to the charge trapping structure of at least one memory cell in the first column and not add charge to the charge trapping structure of at least one memory cell in the second column, applying the voltage setting to the second and third bit lines to cause: 1) at least the sufficient voltage difference between the current terminals of the first column of memory cells to induce the energetic charge in the bodies of the first column of memory cells and 2) the insufficient voltage difference between the current terminals of the second column of memory cells failing to induce the energetic charge in the bodies of the second column of memory cells; and
[0018] D) if the program command is to not add charge to the charge trapping structure of at least one memory cell in the first column and add charge to the charge trapping structure of at least one memory cell in the second column, applying the voltage setting to the second and third bit lines to cause: 1) the insufficient voltage difference between the current terminals of the first column of memory cells failing to induce the energetic charge in the bodies of the first column of memory cells and 2) at least the sufficient voltage difference between the current terminals of the second column of memory cells to induce the energetic charge in the bodies of the second column of memory cells.
[0019] Various embodiments cover the methods of programming the memory cell and the integrated circuit with the nonvolatile memory array.
[0020] The invention covers not only the programming of just two memory cells at a time, but three or more as well.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 is a simplified diagram of a portion of an array of nonvolatile memory cells showing the addition of charge to neighboring cells.
[0022] FIG. 2 is a simplified diagram of a portion of an array of nonvolatile memory cells not showing an addition of charge to neighboring cells.
[0023] FIG. 3 is a simplified diagram of a portion of an array of nonvolatile memory cells that implements a decoded program instruction to add or not add charge to neighboring cells.
[0024] FIG. 4 is a more detailed diagram of neighboring nonvolatile memory cells showing the addition of charge to the neighboring cells.
[0025] FIG. 5 is a more detailed diagram of neighboring nonvolatile memory cells not showing the addition of charge to the neighboring cells.
[0026] FIG. 6 is a simplified block diagram of a nonvolatile memory array with multi-cell programming according to an embodiment of the invention.
DETAILED DESCRIPTION
[0027] FIG. 1 is a simplified diagram of a portion of an array of nonvolatile memory cells. Word line WL N−1 110 supplies a gate voltage of 0 V to the row of nonvolatile memory cells 120 and 121 . Word line WL N 112 supplies a gate voltage of −5 V to the row of nonvolatile memory cells 122 and 123 . Word line WL N+1 114 supplies a gate voltage of 0 V to the row of nonvolatile memory cells 124 and 125 . Bit line BL M 131 supplies a voltage of 5 V to a first current terminal of the first column of memory cells 120 , 122 , and 124 , and to a first current terminal of the second column of memory cells 121 , 123 , and 125 . Bit line BL M+1 132 supplies a voltage of 0 V to a second current terminal of the first column of memory cells 120 , 122 , and 124 . Bit line BL M−1 130 supplies a voltage of 0 V to a second current terminal of the second column of memory cells 121 , 123 , and 125 . The charge storage state of the charge storage structure of nonvolatile memory cells 122 and 123 are programmed. The charge storage state of the charge storage structure of nonvolatile memory cells 120 , 121 , 124 , and 126 are not programmed because of gate voltage that is insufficient to move energetic charge in the bodies of the nonvolatile memory cells across the bottom dielectric into the charge trapping structure. The charge trapping structure of each of the nonvolatile memory cells 120 , 121 , 122 , 123 , 124 , and 125 has parts corresponding to the different current terminals. In nonvolatile memory cells 122 and 123 , the charge is added to the charge trapping structure via band-to-band hot holes. More specifically, the charge trapping structure by the bit line BL M 131 has charge added. This type of programming has the advantage of speed, by simultaneously programming nonvolatile memory cells 122 and 123 .
[0028] FIG. 2 is a simplified diagram of a portion of an array of nonvolatile memory cells. In FIG. 2 , bit line BL M+1 132 supplies a voltage of 3 V to a second current terminal of the first column of memory cells 120 , 122 , and 124 . Bit line BL M−1 130 supplies a voltage of 3 V to a second current terminal of the second column of memory cells 121 , 123 , and 125 . Despite the gate voltage that is insufficient to move energetic charge in the bodies of the nonvolatile memory cells 122 and 123 across the bottom dielectric into the charge trapping structure, nonvolatile memory cells 122 and 123 are not programmed. Nonvolatile memory cells 122 and 123 are not programmed because the voltage difference between bit line BL M+1 132 and bit line BL M 131 is too small for the column of nonvolatile memory cells 120 , 122 , and 124 ; and the voltage difference between bit line BL M−1 130 and bit line BL M 131 is too small for the column of nonvolatile memory cells 121 , 123 , and 125 . The voltage difference between the bit line pairs is insufficient to induce energetic charge to the bodies of the memory cells. This type of programming has the advantage of maintaining a bias on bit line BL M 131 that is sufficient to induce energetic charge in the body of a nonvolatile memory cell if the other bit line of the memory cell is grounded, but programs neither nonvolatile memory cell 122 nor nonvolatile memory cell 123 .
[0029] FIG. 3 is a simplified diagram of a portion of an array of nonvolatile memory cells. Word line WL N−1 110 supplies a gate voltage of V N−1 to the row of nonvolatile memory cells 120 and 121 . Word line WL N 112 supplies a gate voltage of V N to the row of nonvolatile memory cells 122 and 123 . Word line WL N+1 114 supplies a gate voltage of V N+1 to the row of nonvolatile memory cells 124 and 125 . Bit line BL M 131 supplies a voltage of V M to a first current terminal of the first column of memory cells 120 , 122 , and 124 , and to a first current terminal of the second column of memory cells 121 , 123 , and 125 . Bit line BL M+1 132 supplies a voltage of V M+1 to a second current terminal of the first column of memory cells 120 , 122 , and 124 . Bit line BL M−1 130 supplies a voltage of V M−1 to a second current terminal of the second column of memory cells 121 , 123 , and 125 .
[0030] The nonvolatile memory array of FIG. 3 applies the voltages and voltage settings for the voltages V N−1 , V N , V N+1 , V M+1 , V M , V M−1 as follows:
Add charge to charge Add charge to charge trapping trapping structure part structure part of cell 123 by of cell 122 by bit line other bit line BL M BL M+1 /BL M−1 V M+1 V M V M−1 V N−1 V N V N+1 Yes Yes 0 V 5 V 0 V 0 V −5 V 0 V Yes No 0 V 5 V 3 V 0 V −5 V 0 V No Yes 3 V 5 V 0 V 0 V −5 V 0 V No No 3 V 5 V 3 V 0 V −5 V 0 V 0 V 0 V 0 V 0 V −5 V 0 V
[0031] FIG. 4 is a simplified diagram of two charge trapping memory cells sharing a word line and a bit line, showing a program operation being performed on the part of the charge trapping structure of each nonvolatile cell by the shared bit line. The p-doped substrate region 490 or 491 includes n+ doped current terminals 450 , 460 , and 470 . n+ doped current terminal 460 is the first current terminal of both memory cells. The remainder of the first memory cell includes a bottom dielectric structure 440 on the substrate, a charge trapping structure 430 on the bottom dielectric structure 440 (bottom oxide), a top dielectric structure 420 (top oxide) on the charge trapping structure 430 , and a gate 410 on the oxide structure 420 . The remainder of the second memory cell includes a bottom dielectric structure 441 on the substrate, a charge trapping structure 431 on the bottom dielectric structure 441 (bottom oxide), a top dielectric structure 421 (top oxide) on the charge trapping structure 431 , and a gate 410 on the oxide structure 421 . The gate 410 is actually a word line providing a gate voltage to the oxide structure 420 of the first memory cell and the oxide structure 420 of the second memory cell. Representative top dielectrics include silicon dioxide and silicon oxynitride having a thickness of about 5 to 10 nanometers, or other similar high dielectric constant materials including for example Al 2 O 3 . Representative bottom dielectrics include silicon dioxide and silicon oxynitride having a thickness of about 3 to 10 nanometers, or other similar high dielectric constant materials. Representative charge trapping structures include silicon nitride having a thickness of about 3 to 9 nanometers, or other similar high dielectric constant materials, including metal oxides such as Al 2 O 3 , HfO 2 , and others. The charge trapping structure may be a discontinuous set of pockets or particles of charge trapping material, or a continuous layer as shown in the drawing.
[0032] The memory cell for PHINES-like cells has, for example, a bottom oxide with a thickness ranging from 2 nanometers to 10 nanometers, a charge trapping layer with a thickness ranging from 2 nanometers to 10 nanometers, and a top oxide with a thickness ranging from 2 nanometers to 15 nanometers.
[0033] In some embodiments, the gate comprises a material having a work function greater than the intrinsic work function of n-type silicon, or greater than about 4.1 eV, and preferably greater than about 4.25 eV, including for example greater than about 5 eV. Representative gate materials include p-type poly, TiN, Pt, and other high work function metals and materials. Other materials having a relatively high work function suitable for embodiments of the technology include metals including but not limited to Ru, Ir, Ni, and Co, metal alloys including but not limited to Ru—Ti and Ni-T, metal nitrides, and metal oxides including but not limited to RuO2. High work function gate materials result in higher injection barriers for electron tunneling than that of the typical n-type polysilicon gate. The injection barrier for n-type polysilicon gates with silicon dioxide as the top dielectric is around 3.15 eV. Thus, embodiments of the present technology use materials for the gate and for the top dielectric having an injection barrier higher than about 3.15 eV, such as higher than about 3.4 eV, and preferably higher than about 4 eV. For p-type polysilicon gates with silicon dioxide top dielectrics, the injection barrier is about 4.25 eV, and the resulting threshold of a converged cell is reduced about 2 volts relative to a cell having an n-type polysilicon gate with a silicon dioxide top dielectric.
[0034] In the diagram of FIG. 4 , the charge trapping structure part of each cell by the current terminal 460 of each memory cell has been programmed, for example via band-to-band hot hole injection of holes 435 and 436 into the charge trapping structures 430 and 431 , respectively. Other program and erase techniques can be used in operation algorithms applied to the PHINES-type memory cell, as described for example in U.S. Pat. No. 6,690,601. Other memory cells and other operation algorithms might also be used.
[0035] FIG. 5 is a simplified diagram of two charge trapping memory cells sharing a word line and a bit line. The voltage setting is changed in that neither of the memory cells is programmed. Even with a bias on bit line 460 that is sufficient to induce energetic charge in the bodies 490 and 491 of the nonvolatile memory cells with a corresponding voltage on the other bit line, the other bit line 450 and 470 has a voltage which causes an insufficient voltage difference between the bit line pairs that fails to induce energetic charge in the bodies 490 and 491 of the nonvolatile memory cells.
[0036] FIG. 6 is a simplified block diagram of an integrated circuit according to an embodiment. The integrated circuit 660 includes a memory array 600 implemented using charge trapping memory cells, on a semiconductor substrate. A row decoder 601 is coupled to a plurality of word lines 602 arranged along rows in the memory array 600 . A column decoder 603 is coupled to a plurality of bit lines 604 arranged along columns in the memory array 600 . Addresses are supplied on bus 670 to column decoder 603 and row decoder 601 . Sense amplifiers and data-in structures in block 606 are coupled to the column decoder 603 via data bus 607 . Data is supplied via the data-in line 611 from input/output ports on the integrated circuit 660 , or from other data sources internal or external to the integrated circuit 660 , to the data-in structures in block 606 . Data is supplied via the data-out line 610 from the sense amplifiers in block 606 to input/output ports on the integrated circuit 660 , or to other data destinations internal or external to the integrated circuit 660 . A bias arrangement state machine 609 controls the application of bias arrangement supply voltages 608 , such as for the erase verify and program verify voltages, and the arrangements for programming multiple selected cells, erasing, and reading the memory cells.
[0037] While the present invention is disclosed by reference to the preferred embodiments and examples detailed above, it is to be understood that these examples are intended in an illustrative rather than in a limiting sense. It is contemplated that modifications and combinations will readily occur to those skilled in the art, which modifications and combinations will be within the spirit of the invention and the scope of the following claims. What is claimed is: | Programming nonvolatile memory cells is affected by the program disturb effect which causes data accuracy issues with nonvolatile memory. Rather than masking the voltage conditions that cause the program disturb effect, voltages are applied to neighboring nonvolatile memory cells, which takes advantage of the program disturb effect to program multiple cells quickly. | 6 |
RELATED APPLICATIONS
[0001] The present application is a National Phase entry of PCT Application No. PCT/IB2014/002334, filed Oct. 1, 2014, which claims priority from EP Patent Application No. 13306355.2, filed Oct. 1, 2013, said applications being hereby incorporated by reference herein in their entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to the domain of fluid characteristics measurements and especially to the domain of the determination of fluid/gas characteristics in a well.
BACKGROUND OF THE INVENTION
[0003] The approaches described in this section could be pursued, but are not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated herein, the approaches described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section. Furthermore, all embodiments are not necessarily intended to solve all or even any of the problems brought forward in this section.
[0004] During the drilling of a well or during the “open hole” period of the drilled well, it may be advantageous to characterize, in real time, the gas (or more generally the fluid) in the well.
[0005] For instance, it may be interesting to determine the proportion of each cut of C1-C30 in the fluid (i.e. molecules that have 1 to 30 carbon atoms).
[0006] If it is possible to determine the individual proportion and characteristic of each cut C1-C30 in a given fluid in laboratories, no industrial method/device may be used in a well to determine such proportions and characteristics for each of them.
[0007] For instance, mud gas measurements (e.g. “Gas While Drilling” or GWD) have a sufficient level of reliability to consider that the composition of the cuts C1 to C5 (eventually C6) may be determined all along the well. Nevertheless, no individual information regarding the cuts above C 6 , i.e. C i>6 cuts (i.e. molecules with i carbons, i being strictly higher than 6) may be drawn from GWD measurements: such measurements are limited to the light end of the fluid and, consequently, cannot provide straightforward conclusions on the fluid nature and properties.
[0008] In addition, “Downhole Fluid Analysis” (or DFA, which is a measurement method based mainly on optical analysis of the fluid at given coordinates in the well) may provide real time measurements of fluid properties while pumping out the reservoir fluid at selected stations (i.e. at selected elevation values). These DFA methods provide information on composition of groups of molecules, for instance, the group of C1, the group of C2-C5 or the group of C6+ (i.e. the molecules with 6 or more than 6 carbons). DFA methods also provide GOR (for “Gas oil ratio”) and live downhole fluid density. Nevertheless, no individual information regarding the individual cuts above C 6 , i.e. C i>6 cuts (i.e. molecules with i carbons, i being strictly higher than 6) may be drawn from DFA measurements: DFA only provide the grouped weight concentration of the C6+ group.
[0009] In brief, the mud gas service (GWD) cannot quantify full cuts heavier than C6 and optical fluid techniques (DFA) only deliver a lumped C6+ cut at selected stations (i.e. at selected elevation values).
[0010] Based on this sparse set of data (C1 to C5 and C1, C2-C5, C6+), there is a need to determine information on higher full cuts (for instance, C7, . . . , C30) in a thermodynamically consistent and vertically continuous approach.
SUMMARY OF THE INVENTION
[0011] The invention relates to a method of determination of fluid characteristics in a well. Said method comprises:
/a/ receiving mass ratios, each mass ratio being associated with a set of hydrocarbon cuts, and receiving a molecular ratio, said molecular ratio being associated with a set of hydrocarbon cuts; /b/ converting received mass ratios into molecular ratios based on predetermined molecular weights, each predetermined molecular weights being associated an element in the sets of hydrocarbon cuts; /c/ normalizing converted molecular ratios with the received molecular ratio; /d/ determining parameters (α,β) of a sequence defined by
[0000]
x
n
=
α
(
1
-
β
n
)
x
n
-
1
,
each normalized molecular ratio being associated with a member of the sequence or a sum of members of the sequence, at least a difference between said normalized molecular ratio and the associated member or the associated sum of members being minimized;
/e/ computing an estimated molecular weight function of
[0000]
(
k
+
1
1
-
α
)
Δ
M
,
where k being an integer and ΔM being a predetermined value representing an molecular weight increment between two hydrocarbon cuts;
/f/ if a stabilization criteria is met, the steps /b/ to /f/ are iterated with the estimated molecular weight as one of the predetermined molecular weights in step /b/;
/g/ outputting the values of the parameters determined in step /d/.
[0019] Mass ratios are often provided by DFA measurements. For instance, the mass ratio x m1 may be associated with the set of hydrocarbon cuts C1, the mass ratio x m2-5 may be associated with the set of hydrocarbon cuts C2-C5, mass ratio x 6+ may be associated with the set of hydrocarbon cuts C6 and above.
[0020] The received molecular ratio is, for instance, a molecular ratio of a cut (e.g. C1 or C3) provided by GWD measurements.
[0021] It also is possible to receive additional molecular ratios information in order to increase the resolution of the determination of step /d/. For instance, such molecular ratios may be related to C1 to C5 cuts and provided by GWD measurements. In that case, it is also possible to normalize such additional molecular ratios with the molecular ratio received in step /c/.
[0022] Each set of cuts having a molecular weight (e.g. the molecular weight of the set of cuts C2-C5 may be noted Mw 2-5 ), it may be possible to multiply the molecular weight (e.g. Mw 2-5 ) by the mass ratio (e.g. x m2-5 ) to obtain a molecular ratio (e.g. of cut C2-C5).
[0023] The converted/normalized molecular ratio of cut k (respectively k−1) is associated with the member x k of the sequence (respectively the sum of the members x k to x 1 ).
[0024] Therefore, the parameter (α,β) may be determined and thus, any molecular ratio x n =
[0000]
α
(
1
-
β
n
)
x
n
-
1
[0000] (n being an integer) may be computed for a given elevation value.
[0025] The normalization with an external molecular ratio may ease the convergence of the value of the molecular weight. Without such normalization, the molecular weight may not converge.
[0026] In addition, the estimated molecular weight may represent hydrocarbon cuts having more than k carbons.
[0027] In a possible embodiment, the stabilization criteria of step /f/ may comprise at least one following condition:
an absolute difference of a value of α between two iterations of steps /b/-/f/ is lower than a predetermined threshold; an absolute difference of a value of the estimated molecular weight between two iterations of steps /b/-/f/ is lower than a predetermined threshold; a number of iteration of steps /b/-/f/ exceeds a predetermined value.
[0031] For instance, ΔM may be initially set to a value between 12 and 14.
[0032] In a possible embodiment, ΔM may be initially set a mean value for various fluids compositions examined in laboratory conditions.
[0033] The invention relates also to a broader method to determine fluid characteristics for a plurality of elevation values in a well which enables the above mentioned method. Said latter method may comprise:
/i/ determining a plurality of values α by executing steps /a/ to /g/ of the above methods for each of the elevation values; /ii/ determining a mean molecular weight increment value by computing a plurality of values
[0000]
RT
g
(
z
i
-
z
j
)
ln
(
α
(
z
i
)
α
(
z
j
)
)
,
z
i
being an elevation value in the plurality of elevation values and α(z i ) being the determined value α in step /i/ for the elevation value z i , z j being an elevation value in the plurality of elevation values different from z i and α(z j ) being the determined value α in step /i/ for the elevation value z j ;
/iii/ if a stabilization criteria is met, the steps /i/ to /iii/ are iterated with the mean molecular weight increment value as ΔM in step /e/.
/iv/ outputting the values of the parameters determined in step /i/ and the mean molecular weight increment value determined in step /ii/.
[0038] Then, it is possible to determine, for any elevation value z, any molecular ratio
[0000]
x
n
=
α
(
1
-
β
n
)
x
n
-
1
[0000] (n being an integer), assuming that
[0000]
α
(
z
+
dz
)
=
α
(
z
)
·
Δ
M
ij
g
(
dz
)
RT
.
[0039] In addition, the stabilization criteria of step /iii/ may comprise at least one following condition:
an absolute difference of a value of the mean molecular weight increment value between two iterations of steps /i/-/iii/ is lower than a predetermined threshold; a number of iteration of steps /i/-/iii/ exceeds a predetermined value.
[0042] A second aspect relates to a computer program product comprising a computer readable medium, having thereon a computer program comprising program instructions. The computer program is loadable into a data-processing unit and adapted to cause the data-processing unit to carry out the method described above when the computer program is run by the data-processing unit.
[0043] Other features and advantages of the method and apparatus disclosed herein will become apparent from the following description of non-limiting embodiments, with reference to the appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0044] The present invention is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings, in which like reference numerals refer to similar elements and in which:
[0045] FIG. 1 is a flow chart describing a possible embodiment of the present invention to determine any molecular fraction for a given elevation value;
[0046] FIG. 2 is a flow chart describing a possible embodiment of the present invention to determine any molecular fraction for any elevation values;
[0047] FIG. 3 is a flow chart describing a possible determination of the molecular volume for a group of cuts C6+;
[0048] FIG. 4 is a flow chart describing a possible determination of the critical temperature for a group of cuts C6+;
[0049] FIG. 5 is a possible embodiment for a device that enables the present invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0050] FIG. 1 is a flow chart describing a possible embodiment of the present invention to determine any molecular fraction for a given elevation value.
[0051] In order to describe the relation between concentrations of various cuts, it is possible to develop models. These models should be able to provide a simplified but robust fluid description theory adapted to the mudlogging and sampling contexts and based on few measurements, possibly biased (OBM filtrate pollution, mud gas contaminants . . . ).
[0052] For instance, it is possible to use a model developed by Montel F. (1993) which postulates that the molecular fraction x n of the hydrocarbon cut of rank n is related to the previous cut concentration x n-1 by the formula:
[0000]
x
n
=
α
(
1
-
β
n
)
x
n
-
1
[0053] with α, β two parameters to be determined.
[0054] The two α and β parameters (both comprised between 0 and 1, unitless) characterize the chemistry of a hydrocarbon fluid at a given depth; α mainly controls the concentration of heavy cuts while β drives the light ones. α deals with the logarithmic decay of the concentration of each cut while β adds an extra-curvature to the composition pattern.
[0055] When known, α and β can be used to predict a fluid composition (i.e. x n for each n in [1;30] for instance) by extrapolating the concentration of a given cut to the next ones.
[0056] When unknown, α and β may be determined based on a regression approach (for instance). To determine α and β, the following steps may be executed.
[0057] It is possible to receive GWD measurements ( 101 ) of various lights cuts (for instance C1 to C6 or to Ck, with k>1) for each elevation values z in the well. These GWD measurements are values representing molecular ratio of the different cuts. These measurements are optional as they improve the resolution of the below process but are not mandatory.
[0058] In addition, it is possible to receive DFA measurements ( 102 ) of various grouped cuts (for instance C1, C2-C5 and C6+ or Ck+) for various elevation values in a set of values {z 1 , . . . , z n } in the well. These DFA measurements are values representing mass ratio of the different group of cuts.
[0059] For DFA values at a given elevation value z ( 103 ), it is possible to convert them into molecular ratio (step 104 ). Indeed, the molecular weight (Mw) of each cut in C1, C2, C3, C4, C5 (Mw 1 , Mw 2 , Mw 3 , Mw 4 , Mw 5 ) may be known (e.g. tabulated values) and the molecular weight of the grouped cut C6+ (Mw 6+ ) may be approximated by a first mean value ( 105 ) of different known fluids examined in laboratory conditions.
[0060] Once, this transformation performed (i.e. mass ratio value transformed into molecular ratio value), it is possible to normalize the DFA values (step 106 ). This normalization may comprise the division of each converted cuts values (of cuts C1, C2-C5 and C6+) by a value of any other cut (e.g. C3) expressed originally in molecular fraction (molecular ratio received from GWD measurement for instance). The normalized values of DFA values are noted: x 1-DFA , x 2-5-DFA , x 6+-DFA .
[0061] It is also possible to normalize the GWD values (step 107 ). This normalization may comprise the division of each received cuts values (of cuts C1, C2, C3, C4, C5 and C6) by the values of the same cut used for the normalization of the DFA converted cuts values. The normalized values of GWD values are noted: x 1-CWD , x 2-CWD , x 3-GWD , x 4-GWD , x 5-GWD , x 6-CWD .
[0062] The normalizations make possible the comparison of GWD and DFA measurements and increase the convergence.
[0063] Once, DFA values and GWD values are normalized, the values α and β ( 109 ) are determined (step 108 ). For instance, this determination is based on the minimization of the sum (or weighted sum) of distances (i.e. the distance between x and y being d(x,y)) of the values of the curve defined by
[0000]
x
n
=
α
(
1
-
β
n
)
x
n
-
1
[0000] and the normalized values of DFA and/or GWD. For instance, the distances to minimize may be:
d(x 1 ,x 1-GWD ) and d(x 1 ,x 1-DFA ); d(x 2 ,x 2-GWD ); d(x 3 , x 3-GWD ); d(x 4 ,x 4-GWD ); d(x 5 ,x 5-GWD ); d(Σ i=2 5 x i ,x 2-5-DFA ); d(x 6 ,x 6-GWD ); d(Σ i=6 ∞ x i , x 6+-DFA ).
[0072] In addition, it is possible to include in the minimization process some additional distances based on ratio. For instance:
[0000]
-
d
(
∑
i
=
3
5
x
i
∑
i
=
3
∞
x
i
,
x
3
-
5
-
DFA
x
3
-
6
+
-
DFA
)
.
[0073] In a possible embodiment, it is possible to exclude from the minimization process the distance with cuts C1 and C2 alone (e.g. d(x 1 ,x 1-GWD ), d(x 1 ,x 1-DFA ), and d(x 2 ,x 2-GWD )) as these distances may carry artefacts/noises related to biological phenomena.
[0074] As α and β are values in [0;1], it is possible to start the minimization process (of a sum of above mentioned distances) with α=0.5 and β=0.5 and modify α and β (for instance, by dichotomy) to improve the computed sum. For instance, it is possible to compute every possible couple (α; β) in [0;1] 2 with a step of 0.001 (for instance) and to determine (α; β) that minimalizes the computed sum.
[0075] The minimization process may compute the sum of the square of each above mentioned distances instead of simply the sum of said distances (mean-square method).
[0076] Once, α and β are determined ( 109 ), the value of Mw 6+ is computed (step 110 ) based on the following formula:
[0000]
Mw
(
Ck
+
)
=
Mw
k
+
=
(
k
+
1
1
-
α
)
Δ
M
[0077] with ΔM(g/mol) is the molecular weight increment between two subsequent cuts, generally comprised for pure alkanes between 12 (one carbon increment) and 14 g/mol (a —CH2- increment) and k a cut value (for instance set to 6 for computing Mw 6+ ).
[0078] The value of ΔM ( 110 ΔM ) is first set to an arbitrary value between 12 and 14 (for instance 13 or a mean value for various fluids compositions examined in laboratory conditions).
[0079] The test 111 verifies a stabilization criterion. Such stabilization criterion may comprise one below condition or a combination (and/or) of below conditions:
the value of α is stabilized (i.e. the absolute difference between the value of α before the execution of steps 104 to 110 and after the execution of steps 104 to 110 is lower than a certain threshold, for instance 10 −6 ). If the value of α is not yet set/determined before the execution of steps 104 to 110 , α may be set to a predetermined and arbitrary value (e.g. 1 or 0). the value of Mw 6+ is stabilized (i.e. the absolute difference between the value of Mw 6+ before the execution of steps 104 to 110 and after the execution of steps 104 to 110 is lower than a certain threshold, for instance 10 −6 ). the number of reiteration of steps 104 , 106 , 108 , 109 , 110 and 111 exceeds a predetermined number (e.g. 1000 iterations).
[0083] If the stabilization criterion is not verified (i.e. all conditions or at least one condition is not met, test 111 , output NOK), the steps 104 , 106 , 108 , 109 , 110 and 111 are reiterated.
[0084] If the stabilization criterion is verified (i.e. all conditions or at least one condition is met, test 111 , output OK), the values of α and β are output ( 112 ).
[0085] Thanks to the determination of α and β for the elevation value z, it is then possible to determine any molecular fraction x n of the hydrocarbon cut of rank n (at the elevation value z) by applying the following formula
[0000]
x
n
=
α
(
1
-
β
n
)
x
n
-
1
[0000] and by knowing at least x 1 .
[0086] FIG. 2 is a flow chart describing a possible embodiment of the present invention to determine any molecular fraction of cuts for any elevation values.
[0087] In this embodiment, the process described in FIG. 1 (i.e. the block 100 ) is executed for a plurality of elevation values z 1 , z 2 , z 3 , etc. (i.e. step 100 a for z 1 , step 100 b for z 2 , step 100 c for z 3 , etc.). The plurality of elevation values are elevation values of DFA measurements.
[0088] Therefore, a plurality of couples α and β (i.e. 201 a , 202 b , 202 c , etc.) may be determined as the output of the processes 100 a , 100 b , 100 c , etc. Once these plurality of couples (α; β) are determined, it is possible to determine (steps 202 ab , 202 ac , etc.), for each couple (z i ; z j ) i>j , a molecular weight increment ΔM ij based on the following formula:
[0000]
α
(
z
i
)
=
α
(
z
i
)
·
Δ
M
ij
g
(
z
i
-
z
j
)
RT
[0089] with g the gravitational constant, T the mean temperature at elevation values z i and z j , R the gas constant.
[0000]
Δ
M
ij
=
RT
g
(
z
i
-
z
j
)
ln
(
α
(
z
i
)
α
(
z
j
)
)
[0090] Therefore, if the process 100 is executed for n elevation level
[0000]
C
n
2
=
n
·
n
-
1
2
[0000] molecular weight increments ΔM ij are determined (e.g. 203 , 204 ).
[0091] Thus, it is possible to determine ΔM , the mean value of all determined molecular weight increments ΔM ij (step 205 ).
[0092] If the value ΔM is stabilized (i.e. the value of ΔM is very close to the value of the molecular weight increment ΔM used in step 110 of FIG. 1 , e.g. the difference being less than 10 −6 g/mol) (test 206 , output OK), the values of (α; β) for each elevation level and the value of ΔM are returned ( 207 ).
[0093] If the value ΔM is not stabilized, the value of ΔM used in step 110 of FIG. 1 is replaced by the value of ΔM and the steps 100 a , 100 b , 100 c , 201 a , 201 b , 201 c , 202 ab , 202 ac , 203 , 204 , 205 , 206 are reiterated.
[0094] Test 206 may also take into account a maximal number of iterations (e.g. if the number of iteration is greater than a predetermined number of times, the values of (α; β) for each elevation value and the value of ΔM are returned ( 207 )).
[0095] Thanks to the determination of α, β and ΔM for a plurality of elevation values, it is then possible to determine any molecular fraction x n of the hydrocarbon cut of rank n (at any elevation value z) by applying the following formulas
[0000]
x
n
=
α
(
1
-
β
n
)
x
n
-
1
and
α
(
z
+
dz
)
=
α
(
z
)
·
Δ
M
ij
g
(
dz
)
RT
[0000] (by knowing at least x 1 for each elevation value z).
[0000]
Mw
k
+
=
(
k
+
1
1
-
α
)
Δ
M
_
[0000] may also be determined based on the knowledge of α and ΔM (at any elevation value z)
[0096] FIG. 3 is a flow chart describing a possible determination of the molecular volume for any elevation value and for a group of cuts C6+.
[0097] The molecular volume for full cuts C1 to C5 may be known and tabulated. Nevertheless, the molecular volume for the group of cuts C6+ is unknown due to the presence of isomers in the various cuts above C6.
[0098] To determine the molecular volume for the group of cuts C6+ (i.e. ρ 6+ 0 (z)), the gas-oil volume ratio at the surface (or GOR, 301 ) obtained by DFA measurements is received.
[0099] In addition, the molecular weight of the group of cuts C6+ (302) may be obtained based on the above mentioned formula
[0000]
Mw
(
C6
+
)
=
Mw
6
+
=
(
6
+
1
1
-
α
)
Δ
M
,
[0000] α being determined thanks to the process described in relation to FIG. 1 and ΔM being determined thanks to the process described in relation to FIG. 2 .
[0100] Furthermore, it is possible to determine the molecular ratio x i ( 303 ) of each cuts i (i>0, i integer) thanks to the values of α and β determined by the process described in relation to FIG. 1 :
[0000]
x
n
=
α
(
1
-
β
n
)
x
n
-
1
,
[0000] the first values of x i being known thanks to the GWD measurements.
[0101] Thus, once all these values received, it is possible to determine the molecular volume for the group of cuts C6+ (step 304 ) for each elevation values where a DFA measurement is performed. Indeed, it is possible to express that:
[0000]
ρ
k
+
0
(
z
)
=
x
k
+
L
Mw
6
+
GOR
·
ρ
G
0
(
∑
i
=
p
k
x
i
L
·
Mw
i
)
(
∑
i
=
1
p
-
1
x
i
·
Mw
i
∑
i
=
p
k
x
i
·
Mw
i
)
-
GOR
·
ρ
G
0
∑
i
=
p
k
-
1
x
i
L
·
Mw
i
ρ
i
0
(
k
=
6
,
for
instance
)
[0000] considering that:
p is an integer representing the rank of the first cut in the liquid phase, it is assumed that C1 to Cp−1 are gas fluid and that cuts above Cp are liquid fluid (e.g. p equals, most of the time, 4 or 5); ρ G 0 being the molecular density of the gas at the surface level of the well extracted from the oil (this value is known as the value are tabulated as p<6); x i L being the molecular ratio of the cut Ci in the liquid cuts
[0000]
x
j
L
=
x
j
∑
i
=
p
q
x
i
;
[0105] Indeed, the GOR value may be expressed by the following formula:
[0000]
GOR
=
∑
i
=
1
p
-
1
x
i
·
Mw
i
ρ
G
0
∑
i
=
p
q
x
i
·
Mw
i
ρ
L
0
ρ L 0 being the molecular density of the liquid at the surface level of the well ρ L 0 =
[0000]
∑
i
=
p
q
x
i
L
·
Mw
i
∑
i
=
p
q
x
i
L
·
Mw
i
ρ
i
0
;
q is an integer representing the rank of the last cut in the liquid phase (e.g. q=30 or 60, etc.);
[0108] Once the molecular volume for the group of cuts C6+ (step 304 ) ρ 6+ 0 (z) are determined for a plurality of elevation values z (these elevation values are elevation values of stations where DFA measurements took place), it is verified that the values ρ 6+ 0 (z) are proportional to the values of Mw 6+ (z). In particular, the coefficients γ and δ are determined (step 305 ) to minimize the distance of points of coordinates (ρ 6+ 0 (z), Mw 6+ (z)) (z in the elevation values stations where DFA measurements took place) with the curve defined by γ. Mw 6+ (z)+δ.
[0109] If the residue of the minimization (e.g. the sum of the distances of points of coordinates (ρ 6+ 0 (z), Mw 6+ (z)) with the defined curve γ. Mw 6+ (z)+δ) is bigger than a predetermined threshold (test 306 , output OK), the measured GOR value is modified within the known uncertainty range defined per tool type (because it is assumed that the GOR value may comprise important level of noises during the measurements) (step 307 ). This modification of the GOR value (which is in the interval [0,1]) may be performed by dichotomy.
[0110] If the residue of the minimization is not bigger than a predetermined threshold (test 306 , output NOK), the value of γ and δ are returned ( 308 ).
[0111] Test 306 may also take into account a maximal number of iterations (e.g. if the number of iteration is greater than a predetermined number of times, the values of γ and δ are returned, 308 ).
[0112] Then, based on the values of γ, δ, and Mw 6+ (z), it is possible to determine any molecular volume for any elevation value and for a group of cuts C6+ by applying the following formulae:
[0000]
ρ
6
+
0
(
z
)
=
γ
·
Mw
6
+
(
z
)
+
δ
ρ
0
(
z
)
=
∑
i
=
1
q
x
i
·
Mw
i
∑
i
=
1
q
x
i
·
Mw
i
ρ
i
0
[0113] FIG. 4 is a flow chart describing a possible determination of the critical temperature for a group of cuts C6+.
[0114] To determine the critical temperature for the group of cuts C6+ (i.e. Tc 6+ (z)), the downhole fluid density (derived from pressure gradients and/or downhole measurements like DFA, or ρ(z) 401 ) is received.
[0115] In addition, the molecular weight of the group of cuts C6+ ( 402 ) may be obtained based on the above mentioned formula
[0000]
Mw
(
6
+
)
=
Mw
6
+
=
(
6
+
1
1
-
α
)
Δ
M
,
[0000] α being determined thanks to the process described in relation to FIG. 1 and ΔM being determined thanks to the process described in relation to FIG. 2 .
[0116] Furthermore, it is possible to determine the molecular ratio x i ( 403 ) of each cuts i (i>0, i integer) thanks to the values of α and β determined by the process described in relation to FIG. 1
[0000]
x
n
=
α
(
1
-
β
n
)
x
n
-
1
,
[0000] the first values of x i being known thanks to the GWD measurements.
[0117] The critical pressure of the group of cuts C6+ may be determined by tabulated data as this value is quite well regular and predictable. Therefore it is possible to use a predetermined function or abacus ( 409 ) to determine the critical pressure of the group of cuts C6+ (i.e. Pc 6+ , function of the molecular weight, for instance)
[0118] Thus, once all these values are received, it is possible to determine Tc 6+ , the critical temperature for the group of cuts C6+ (step 404 ) for each elevation values where a DFA measurement is performed. Indeed, it is possible to express that:
[0000]
ρ
(
z
)
=
ρ
(
P
,
T
)
=
ρ
0
·
C
(
P
0
,
T
0
)
C
(
P
,
T
)
[0000] considering that:
C(P,T) is a surface-to-downhole correction function, C(P,T)=Σ k=0 3 (Σ j=0 4 A kj ·Prj·Trk, A kj are predetermined constants; (Pr,Tr) are, respectively, the reduced pressure (=P/Pc) and temperature (=T/Tc); P 0 and T 0 are the standard conditions (respectively, 1 atm and 15° C.);
[0000]
-
ρ
0
=
∑
i
=
1
q
x
i
·
Mw
i
∑
i
=
1
q
x
i
·
Mw
i
ρ
i
0
;
q is an integer representing the rank of the last cut in the liquid phase (e.g. q=30 or 60, etc.);
Tc 1 to Tc 5 are known and tabulated values.
[0125] Therefore, it is possible to write that:
[0000]
ρ
(
z
)
=
∑
i
=
1
q
x
i
·
Mw
i
∑
i
=
1
q
x
i
·
Mw
i
ρ
i
0
·
∑
k
=
0
3
(
∑
j
=
0
4
A
kj
·
(
P
o
Pc
)
j
)
·
(
T
o
Tc
)
k
∑
k
=
0
3
(
∑
j
=
0
4
A
kj
·
(
P
Pc
)
j
)
·
(
T
Tc
)
k
[0126] In addition, it is noted that Tc=Σ i=1 ∞ x i Tc i =(Σ i=1 5 x i Tc i )+x 6+ Tc 6+ and Pc==Σ i=1 ∞ x i Pc i =(Σ i=1 5 x i Pc i )+x 6+ Pc 6+ . Each x i may be known according to the method described in relation to FIG. 1 . Each Tc i and Pc i (for i<6) are known and tabulated. As detailed above, the critical pressure of the group of cuts C6+ (i.e. Pc 6+ ) may be determined thanks to an abacus. Therefore, only Tc 6+ is unknown.
[0000]
ρ
(
z
)
=
∑
i
=
1
q
x
i
·
Mw
i
∑
i
=
1
q
x
i
·
Mw
i
ρ
i
0
·
∑
k
=
0
3
(
∑
j
=
0
4
A
kj
·
(
P
o
(
∑
i
=
1
5
x
i
Pc
i
)
+
x
6
+
Pc
6
+
)
j
)
·
(
T
o
(
∑
i
=
1
5
x
i
Tc
i
)
+
x
6
+
Tc
6
+
)
k
∑
k
=
0
3
(
∑
j
=
0
4
A
kj
·
(
P
(
∑
i
=
1
5
x
i
Pc
i
)
+
x
6
+
Pc
6
+
)
j
)
·
(
T
(
∑
i
=
1
5
x
i
Tc
i
)
+
x
6
+
Tc
6
+
)
k
[0127] Once Tc 6+ is determined (step 404 , resolution of the above formula that contains only one unknown value, for instance by non-analytical method) for a plurality of elevation values z (these elevation values are elevation values of stations where DFA measurements took place), it is verified that the values ln (Tc 6+ (z)) are proportional to the values of Mw 6+ (z).
[0128] In particular, the coefficients ε and ω are determined (step 405 ) to minimize the distance of points of coordinates (ln (Tc 6+ (z)), Mw 6+ (z)) (z in the elevation values stations where DFA measurements took place) with the curve defined by ε.Mw 6+ (z)+ω.
[0129] If the residue of the minimization (e.g. the sum of the distances of points of coordinates (ln (Tc 6+ (z)), Mw 6+ (z)) with the defined curve ε.Mw 6+ (z)+ω) is bigger than a predetermined threshold (test 406 , output OK), the measured downhole fluid density value is modified within the known uncertainty range defined per tool type (because it is assumed that the downhole fluid density value may comprise important level of noise during the measurements) (step 407 ). This modification of the downhole fluid density value may be performed by dichotomy.
[0130] If the residue of the minimization is not bigger than a predetermined threshold (test 406 , output NOK), the value of ε and ω are returned ( 408 ).
[0131] Test 406 may also take into account a maximal number of iterations (e.g. if the number of iteration is greater than a predetermined number of times, the values of ε and ω are returned, 408 ).
[0132] Then, based on the values of ε, ω, and Mw 6+ (z), it is possible to determine any compressibility factor C(P,T,z) for any elevation value by applying the following formulae:
[0000]
ln
(
Tc
6
+
(
z
)
)
=
ɛ
·
Mw
6
+
(
z
)
+
ω
C
(
P
,
T
,
z
)
=
∑
k
=
0
3
(
∑
j
=
0
4
A
kj
·
(
P
(
z
)
Pc
(
z
)
)
j
)
·
(
T
(
z
)
Tc
(
z
)
)
k
;
Pc
(
z
)
=
(
∑
i
=
1
5
x
i
(
z
)
·
Pc
i
)
+
x
6
+
(
z
)
·
Pc
6
+
(
z
)
Tc
(
z
)
=
(
∑
i
=
1
5
x
i
(
z
)
·
Tc
i
)
+
x
6
+
(
z
)
·
Tc
6
+
(
z
)
[0133] Part of these flow charts ( FIGS. 1 to 4 ) can represent steps of an example of a computer program which may be executed by the device of FIG. 5 .
[0134] FIG. 5 is a possible embodiment for a device that enables the present invention.
[0135] In this embodiment, the device 500 comprise a computer, this computer comprising a memory 505 to store program instructions loadable into a circuit and adapted to cause circuit 504 to carry out the steps of the present invention when the program instructions are run by the circuit 504 .
[0136] The memory 505 may also store data and useful information for carrying the steps of the present invention as described above.
[0137] The circuit 504 may be for instance:
a processor or a processing unit adapted to interpret instructions in a computer language, the processor or the processing unit may comprise, may be associated with or be attached to a memory comprising the instructions, or the association of a processor/processing unit and a memory, the processor or the processing unit adapted to interpret instructions in a computer language, the memory comprising said instructions, or an electronic card wherein the steps of the invention are described within silicon, or a programmable electronic chip such as a FPGA chip (for <<Field-Programmable Gate Array>>)).
[0142] This computer comprises an input interface 503 for the reception of data used for the above method according to the invention and an output interface 506 for providing the above mentioned data.
[0143] To ease the interaction with the computer, a screen 501 and a keyboard 502 may be provided and connected to the computer circuit 504 .
[0144] Then, at least, the following thermodynamical properties of a fluid can be derived from determined values x n , Mw n , ρ n 0 and C(P,T) (see above):
[0000]
Mw
=
∑
i
=
1
q
x
i
·
Mw
i
ρ
L
0
=
∑
i
=
p
q
x
i
L
·
Mw
i
∑
i
=
p
q
x
i
L
·
Mw
i
ρ
i
0
Bo
=
∑
i
=
1
q
x
i
·
Mw
i
ρ
∑
i
=
1
q
x
i
·
Mw
i
ρ
L
0
GOR
=
∑
i
=
1
p
-
1
x
i
·
Mw
i
ρ
G
0
∑
i
=
1
p
-
1
x
i
·
Mw
i
ρ
L
0
[0145] with p the rank to the first cut in the liquid phase and q the rank of the last cut in the liquid phase.
[0146] Expressions such as “comprise”, “include”, “incorporate”, “contain”, “is” and “have” are to be construed in a non-exclusive manner when interpreting the description and its associated claims, namely construed to allow for other items or components which are not explicitly defined also to be present. Reference to the singular is also to be construed in be a reference to the plural and vice versa.
[0147] A person skilled in the art will readily appreciate that various parameters disclosed in the description may be modified and that various embodiments disclosed may be combined without departing from the scope of the invention.
[0148] In particular, it is apparent for the person skilled in the art that the invention may be enabled for any received cuts (e.g. if properties of cuts below k is known, it is possible to determine ρ k+ 0 (z) and not only ρ 6+ 0 (z), Mw k+ and not only Mw 6+ , Tc k+ and not only Tc 6+ . | The present invention relates to a method for determination of fluid characteristics in a well, by
receiving mass ratios and a molecular ratio; converting the mass ratios into molecular ratios based on predetermined molecular weights; normalizing the converted molecular ratios with the received molecular ratio; minimizing a difference between the normalized molecular ratio and an associated member or an associated sum of members; computing an estimated molecular weight (Mw 6+ ) function of (k+11−αΔM; and if a stabilization criteria is met, the steps are iterated with the estimated molecular weight as one of the predetermined molecular weights. | 4 |
FIELD OF THE INVENTION
[0001] The invention relates to proving existence of and possession of digital content such as documents, sound files, or visual images.
PRIOR ART DISCUSSION
[0002] In the last ten years or so there has been considerable progress in the field of data security, particularly for transmission of data between parties. However there is still a need for improved processes for managing content in a secure manner for a variety of applications such as business contracts and copyright material handling.
[0003] U.S. 2002/0002543 A1 describes a system and method for online copyright management. This involves submitting digital content to an independent body over the internet, receiving a digitally-signed certificate of copyright, allowing such content to be reviewed by third parties over the Web, and allowing third parties to purchase licences to use such copyrighted material according to limitations and rules defined by the copyright owner.
[0004] EP 0940945 A2 describes a system and method whereby a cryptographic hash function is applied to an electronic document to produce a document fingerprint. A second cryptographic hash function is applied to the document fingerprint, a time stamp and a serial number to provide a document certificate fingerprint.
[0005] The issue of preserving and proving a document's integrity has been addressed thus far primarily with digital signature technology, whereby a digital signature is embedded into a document, along with a timestamp obtained from a trusted third party. This involves modifying the original content file and a requirement that the user have a digital certificate. Also, security is ultimately dependent on trust of a third party to establish a document's integrity.
[0006] Some approaches to the problem rely on embedding a cryptographic token in the content, which is represented visually, for example as a stamp. Such approaches have the disadvantage of altering the content itself, and also such technology is typically limited to work with static, visually represented, files such as word processing documents.
[0007] U.S. Pat. No. 7,047,404 (Surety) describes an approach in which a client software application manages multiple content files and obtains digital “seals” from a server (over the internet) which correspond to each file. The content files can be verified against the corresponding seals in a process which again refers back to a server. It appears that because this requires use of a proprietary software application the seal files are proprietary and can only be interpreted by purpose-designed software, and because there is no mechanism to prevent tampering at the server side such systems are highly dependent on trust of third parties.
[0008] The invention is directed towards providing an improved system and method for proving the historic integrity of content.
SUMMARY OF THE INVENTION
[0009] According to the invention, proof of possession of digital content is established in a method comprising certifing a hash value derived from the content. The hash value may be embedded in a certificate of possession, despatch, or delivery, and the certificate may be time stamped and digitally signed.
[0010] According to another aspect, there is provided a method for establishing proof of existence and possession of source digital content, the method comprising the steps of:
generating a content certificate by: a. calculating a content hash derived from the source digital content, b. creating code incorporating the content hash and content details, and a system hosted by a certifying body time-stamping and digitally signing the content hash and the content details to create a content certificate, c. transmitting to a recipient the content certificate via a secure channel, and d. recording the content certificate in a database, creating an unalterable audit trail of certification, by: e. calculating a proving hash of a concatenated file of data relating to a plurality of content certificates, f. publishing the proving hash, and g. retaining the concatenated file, proving existence of content, by: h. verifyng the certified digital content against the content certificate and checking the public key from the digital certificate against a known public key for the certifying body, and i. proving prior existence of the content certificate by reference to the concatenated file of step (e), calculating the hash of this file, and comparing this with the proving hash as published in step (f)
[0022] In one embodiment, steps (e), f) and g) are repeated at regular proving periods.
[0023] Step (e) may comprises calculating a proving hash of a file of concatenated content hashes, or alternatively calculating a proving hash of a file of concatenated content certificates.
[0024] In one embodiment, the time stamp is provided by a secure time stamp server.
[0025] In one embodiment, the content certificate is saved to a secure database associated with a certifying body.
[0026] In one embodiment, the content certificate is embedded into the source digital content; and wherein a space in the source digital content adequate to contain the content certificate outside of the limits of the content and integral structure of a source digital content file is filled with fixed known data before the calculation of the hash at step (a), and subsequently in step (d) the content certificate file is appended to said file in that location, and the file is extended in size if necessary, so that an application for reading the file does not read the content differently.
[0027] In one embodiment, the method is implemented by a client computer and the certifying body system is a server for the client computer. The client computer may use only a browser and an application for reading the source digital content.
[0028] In one embodiment, step (a) is performed by the client computer and the calculated hash is transmitted to the server, but the source digital content is never transmitted to the server.
[0029] In one embodiment, step (a) is performed by a downloaded program executing within a standard browser.
[0030] In one embodiment, step (a) is performed by an offline computer, and the hash is inputted to the client computer, so that the source digital content need not be stored or processed on the client computer.
[0031] In one embodiment, the client computer automatically interfaces with the server without user intervention, and the client computer may execute an API to interface with the server.
[0032] In one embodiment, the method comprises the further steps of a verification program inspecting a source digital content file, identifying certificate data in said file and substituting it with the fixed known values before calculating the hash for comparison purposes.
[0033] In one embodiment, step (i) comprises verifying the prior existence of a content certificate in its full text by reference to an historic file of concatenated certificates and the relevant published proving hash.
[0034] In one embodiment, the content certificate is transmitted in step (c) together with an explanatory message.
[0035] In one embodiment, the content certificate is emailed to the user in step (c) and in parallel a confirmation is displayed on a user's browser.
[0036] In one embodiment, the content is forwarded by email or digitally signed email to a nominated third party.
[0037] In one embodiment, the certifying body sends a digitally signed email to a user certifying that the content has been forwarded to a nominated third party. Preferably, if proof of delivery to nominated third party address is obtained, the certifying body sends a digitally signed email to a user certifying this delivery and providing details.
[0038] In one embodiment, the content is printed or copied to physical medium and delivered by registered delivery to a nominated third party.
[0039] In one embodiment, a message transmitting the content to a nominated third party does not contain the content itself, but instead an internet hyperlink to a download location. Preferably, following the download of content arising from an email with an internet hyperlink to that content, the certifying body sends a digitally signed email to user certifying that such download had taken place with details.
[0040] In one embodiment, a read receipt is obtained from the recipient of email sent to a nominated third party and the certifying body sends a digitally signed email to a user certifying that such a read receipt had been obtained.
[0041] In one embodiment, the content certificate is transmitted in step (c) via digitally signed email
[0042] In one embodiment, the code of step (d) is in a mark-up language such as XML.
[0043] In one embodiment, the proving hash is published in a paper medium.
[0044] In one embodiment, step (h) comprises verifying the certified digital content against the content certificate by calculating the hash of the content and comparing that with the content hash embedded in the content certificate.
[0045] In one embodiment, wherein step (i) comprises proving prior existence of the content certificate by reference to published proving hashes and published historic concatenated files of content hashes without reference to a certifying body.
[0046] In one embodiment, step (i) incorporates checking the public key from the digital certificate against a list of known public keys for the certifying body.
[0047] In another aspect, the invention provides certifying body system for performing certifying body system operations of any method as defined above.
[0048] The invention also provides a computer readable medium comprising software code for implementing the steps of any method as defined above when executing on a digital processor.
DETAILED DESCRIPTION OF THE INVENTION
BRIEF DESCRIPTION OF THE DRAWINGS
[0049] The invention will be more clearly understood from the following description of some embodiments thereof, given by way of example only with reference to the accompanying drawings in which:—
[0050] FIGS. 1 is a flow diagram of operations for establishing proof of possession of content via an internet browser, and FIG. 2 shows a variation whereby in addition to establishing proof of content via an internet browser, the content file is uploaded for onward despatch to a third party with independent representation of this;
[0051] FIG. 3 is flow diagram for a process which differs from that of FIG. 1 in that the certifying process is initiated from within an editing application (e.g. Microsoft Word) rather than a browser on the client PC;
[0052] FIG. 4 is a flow diagram of operations for certifying a previously-calculated hash; and
[0053] FIG. 5 is a flow diagram of operations for a regular periodic (e.g. daily) proving run.
[0054] FIG. 6 is a flow diagram of operations for verifying the prior existence of certified content and the authenticity of the certificate itself.
DESCRIPTION OF THE EMBODIMENTS
Overview
[0055] Referring to FIG. 1 a system and method for establishing proof of possession and existence of digital content is illustrated. A client computer executes a browser and logs onto the Digiprove Web site in an SSL session. The relevant digital content is located locally and a downloaded hashing Applet is executed to generate a content hash, and this is submitted to the Digiprove server. The server retrieves a time stamp from a time stamp server and generates an XML document with the hash, the time stamp, and descriptive text. This is digitally signed to provide a content certificate, called a “Digiprove Certificate”. The Digiprove Certificate is stored in a secure database and is sent via secure email to the client computer at the same time as details being displayed on the client computer browser. The certificate received via secure email is verified by a cryptographic application on the client computer. This authenticates the sender by reference to an X509 digital certificate and the integrity of the message by use of a cryptographic message digest.
[0056] FIG. 2 shows a variation in which the content file is uploaded to the server and the hash is generated on the server. This variation also involves emailing the content file to a nominated third party or physically delivering the content in printed or digital media form to the nominated third party. In this embodiment, there is transmission of the content from the client computer to the server, which may be perceived as a disadvantage. However, on the other hand there is no need for the client to download a hash-generating program and also the server can provide the additional service of sending the content to a nominated third party.
[0057] FIG. 3 shows a variation in which a Digiprove applet executes in the background in a client computer application to allow simple user selection of the process. As in FIG. 1 , the content is not transmitted to the server.
[0058] FIG. 4 illustrates a variation in which the hash is generated offline (on the client computer or a different computer) and is transmitted by the client computer to the server. In this case, neither the client computer nor the server handles the content. In this embodiment, the owner of the content can be absolutely sure of privacy of the content because it has not been handled by any of the computers during communication over the internet.
[0059] A certifying body (referred to herein as “Digiprove”) hosts the server to offer the certifying process over the internet to owners of digital content. The method certifies the hash value mathematically derived from the digital content itself. This value is embedded in the content certificate of possession which is then time-stamped and digitally signed by a “Digiprove” server before being returned to the owner. This avoids need for the digital content itself to be submitted.
[0060] The description below makes reference to a “Digiprove Certificate”. This is a content certificate of possession, despatch, or delivery of digital content, and is not to be confused with the general term “Digital Certificate”, being a certificate of identity in “x509” form which is a basic building block of many internet security implementations.
[0061] The Digiprove Certificate is transmitted in an S/Mime format with embedded XML content, allowing programmatic access to the content, as well as human-readable display and verification through a standard email client.
[0062] The method allows users to prove compliance with corporate and financial law and regulation, to fairly protect themselves in potential future litigation or criminal proceedings. It can also be used to prove despatch and delivery of information to third parties, again to prove compliance or to protect against future litigation. It also has a role in helping people to establish ownership of some intellectual property such as copyright. Other applications include taking of witness statements or other situations where proof of existence and possession of a document or other content is important. Another example is where a video file is generated to prove a residence inventory at a certain time.
[0063] The method permits the date of issue of a Digiprove Certificate to be subsequently proven by publishing on a regular basis a hash of aggregated such certificates for a period.
[0064] The method allows a person to obtain independent certification and proof that he or she is in possession of a file of digital content at a point of time, without revealing its contents to the certifier or any third party, for use in a wide variety of legal, compliance and content management applications. Such digital content, once possession has been certified, can be despatched and delivered to third parties and such despatch and delivery can be independently certified. Also, the method makes forgery of Digiprove Certificates almost impossible. This method uses a sequence of steps including the use of some cryptographic algorithms already proven and in use in internet e-commerce and elsewhere.
The “Digiprove” Processes
User Registration
[0065] Each user must register in order to use the service. The registration only happens once and has three steps:
[0066] a. User submits personal data
[0067] b. User selects membership or subscription type (and makes payment if necessary)
[0068] c. An activation process takes place, such as the e-mailing of an activation code and associated hyperlink for user to action.
Issuing a Digiprove Certificate (FIGS. 1, 2 , 3 , 4 )
[0069] Each time a user wants to have a digital content file “Digiproved”, the following steps are implemented:
Log-on
[0070] The user inputs his User ID and password. He can choose to remain logged on to Digiprove as long as he is logged onto the computer, thus facilitating repeated usage during the session.
Selection of File to be “Digiproved”
[0071] The user can select a file to be “Digiproved” (the “content file”) in one of two ways:
While viewing the Digiprove web-site, he can browse his computer or local network and select the file. Optionally, if the user grants to a downloaded applet write access to his local file system, the content file will then be marked as read-only, or copied as a read-only file into a nominated folder (e.g. “My Documents/My Digiprove Documents”) of the current user, as shown in FIG. 1 As shown in FIG. 2 , while editing the file from within an application on the client computer (any content editor such as word processors, image editors, sound editors), he can select “Digiprove” from the file menu. He is required in this case to be already logged on to Digiprove from earlier. This will cause the file to be saved to the nominated folder of the current user, and the process will continue in the background from there.
Optional Submission of File
[0074] The user may decide to submit the original content file to Digiprove ( FIG. 2 ) for one or more of the following:
Calculation of hash at central server rather than locally on the client computer. Safekeeping of the source content at Digiprove's secure location. For Digiprove to despatch the content file to a named 3 rd party, either by e-mail or physically, or both, and to certify such despatch and subsequently to certify any recorded delivery. In this case, the addressee details are also submitted over the Web.
Calculate/Submit Hash
[0078] This step does not apply if the user is uploading the entire file. If the user uploads the entire file, the calculation of the hash will be done on the server ( FIG. 2 ) and no applets will need to be used.
[0079] An ActiveX (or alternatively Java applet) will run (and be downloaded if not cached from a previous session). This calculates a hash of the file using the “SHA1” algorithm (or another such hashing algorithm in alternative embodiments), and passing this hash to Digiprove while displaying a message such as:
“SHA1 hash of file [Filename and Location] is: XX-XX-XX-XX-XX-XX-XX-XX-XX-XX-XX-XX-XX-XX-XX-XX-XX-XX-XX. Enter optional file description now. To submit this hash to Digiprove.com for certification press “submit” button.” The language of this text may be the preferred language of the registered user.
Advanced User Option
[0084] Referring to FIG. 4 , instead of the foregoing three steps, an advanced user can choose to simply input the hash value which he has calculated separately on the file (perhaps on a separate offline computer) along with the file name and description.
[0000] Integration with Other Software Systems
[0085] To facilitate the easy use of the Digiprove methodology to prove the possession and existence of programmatically produced or administered content without user intervention (e.g. financial audit trails, incoming and outgoing emails), it will also be possible to interact with the Digiprove service via defined APIs (Application Program Interfaces) using a secure protocol which can be used to replace the foregoing steps (from “Log-on”) with the following steps:
Programmatic Log-on Supply and Verification of User ID and Password. Creates a session for repeated submission of file details until log-out. Submission of File Details Supply of filename, hash (calculated by the other software system), and description. These are all the details required to be incorporated in a certificate of possession.
[0090] The API protocol may permit the submission of batches of content to facilitate multiple certificates. In all cases the protocols to be used for the API will employ widely accepted cryptographic techniques to assure authentication of both parties, privacy (encryption), and integrity of data.
[0091] The API protocols will be published to authorised users of the service.
Create Digiprove Certificate
[0092] The following process is performed from the server location:
Read current time from a secure clock Create XHTML, XML, or plain text containing a standard text such as:
“Digiprove certifies that User ID x - - - x, (Name of Submitter) was in possession of the file “Original filename” described below in digital form on the dd mmmmmmmmm yyyy hh:mm:ss UTC. [either:] A copy of “Original Filename” has been retained by Digiprove. [or:] Please retain the original file “Original Filename” safely for your records. To prove the veracity of this certificate and to verify its match to the associated file you can use the program “verify-digiprove-certificate.exe” available at www.digiprove.com/downloads/verify-digiprove-affidavit.exe. Any change to the original file will be detected by the verification program.” Digiprove serial number (of this certificate) Original file name Timestamp (in UTC) File hash Description of file Name of submitter
[0102] Display the above text on the user's computer along with the text “A digitally-signed Digiprove Certificate in the following form is being sent to your email address”
[0103] Send a digitally-signed email in S-mime format with the above text to the submitter. This is the Digiprove certificate. Attached to the email will be a file containing the same information in XML format, to facilitate programmatic verification; this file will itself be digitally signed. This is the Digiprove Certificate file. The format of this file conforms to a widely used standard called PKCS7
Save and retain the Digiprove Certificate as a file.
Despatch and Delivery
[0105] If the user has chosen to upload the content file for the purposes of despatch to a nominated 3 rd party of the content file by recorded delivery, in addition to providing a certificate of possession, the system will generate a certificate of despatch in similar form to the above (i.e. incorporating a hash, time-stamped and digitally signed) adding in details of despatch (method and addressee). Subsequently on receipt of any record of delivery (e.g. when using registered post or courier services), a Certificate of Delivery in similar form will be formulated and sent to the user, incorporating details of delivery acceptance, and potentially including a scanned image of receipt document(s).
Appending a Digiprove Certificate File to Content File
[0106] At the option of the user, the Digiprove Certificate file which was attached to the emailed certificate can be physically appended to the content file. The effect of this is that the content file may be extended in size to accommodate the extra information, although in some cases it will fit within the unused space in the file. Whenever the content file is copied or transmitted (e.g. via email), it will contain this embedded data. Because it is placed after the end of the raw content, the content itself is not disturbed in any way, and this additional data will be ignored by editing and display programs. Thus, as long as the content file is not altered the certificate can travel with it.
Proving the Digiprove Certificates (FIG. 5)
[0107] A proving process guarantees that a Digiprove Certificate has not been forged or created after the fact, either by an outside party or by Digiprove itself. Referring to FIG. 5 , on a periodic basis, all the Digiprove certificates for that period are concatenated into one bulk file (which is retained), and a hash of that file (the Proving Hash) is calculated and published in a printed medium such as a reputable newspaper (any publication that is archived in a public library).
[0108] This creates an unalterable audit trail which can be examined independently to prove the integrity of the Digiprove Certificate. To validate that a given Digiprove Certificate an independent inspector will:
[0109] a. Obtain a copy of the bulk file described above from Digiprove.
[0110] b. Examine the bulk file to ensure that it contains the Digiprove Certificate in question.
[0111] c. Calculate the hash of the bulk file
[0112] d. Verify that the hash conforms to the Proving Hash as published in the chosen newspaper, as archived in public library.
[0113] In a variation of the above steps, on a periodic basis, all the hashes of Digiproved content files for that period are concatenated into one bulk file, which is published on one or more independently hosted web-sites for long-term availability, and a hash of that file (the Proving Hash) is calculated and published in a reputable newspaper.
[0114] This creates an unalterable audit trail which can be examined independently to prove the integrity of the Digiprove Certificate. To validate that a given Digiprove certificate existed at the given date, an independent inspector will:
[0115] a. download the relevant bulk file of hashes from the Web,
[0116] b. examine that bulk file to ensure that it contains the hash contained in the certificate in question,
[0117] c. calculate the hash of the bulk file, and
[0118] d. verify that the hash conforms to the Proving Hash as published in the chosen newspaper, as archived in a public library.
[0119] In a further variation of either of the above proving methods, the Proving Hash for the previous period is also published along with the current Proving Hash to demonstrate continuity of the audit trail.
Verifying a Digiprove Certificate
[0120] To verify a Digiprove certificate a program is run which is made freely available. This has two functions, as set out in FIG. 6 :
[0121] It verifies that the digital signature of a Digiprove Certificate is valid, i.e.:
use the public key in the embedded x509 digital cert to verify that the digital signature corresponds to all the details of the Digiprove Certificate, including the date/time and the file hash—fatal failure if this does not match. Note—most e-mail clients, including Microsoft Outlook will already have verified this on receipt of the message. compare the public key in the digital cert to the list of known public keys for Digiprove to that contained in the X509 digital certificate. There will be a serious warning condition if this does not match.
[0124] Secondly it verifies that a given file is the one certified by the Digiprove Certificate by calculating the hash of the content file and comparing that to the hash embedded in the Digiprove certificate.
[0125] This verification program will work equally when it is given two files (the content file and the Digiprove certificate file), or one file (the content file with the Digiprove certificate file appended to it).
[0126] This verification program will be freely available over the internet and its source code will be published as Open Source and the object code version will be digitally signed by Digiprove.
[0127] This verification process will typically be used by the content owner or a third party if he wishes to verify that a content file had been correctly Digiproved and the time.
[0128] For advanced users, also available from Digiprove will be a program to calculate and display the hash of a given file.
[0129] It will be appreciated that the invention provides a method having the following advantages.
It does not rely on trust in the certifying body (i.e. certificates can not be forged or back-dated, and certification can be verified without reference to certifying body, even after the certifying body ceases to exist. It can be easily invoked from a Web browser on any computer without use of a separate application It can also be invoked from within a client application It can work with all types of content It does not reveal content to Digiprove (in the embodiments of FIGS. 1 and 3 ) or any third party (and can be shown not to do this) Content is not altered in any way Without the content being altered, a certified content file is identifiable as such and is easily verifiable against the Digiprove Certificate Certificates are delivered via a separate channel (secure email) Works with industry-standard data formats and encryption algorithms Does not require user to obtain and install a digital certificate One can forward certified content independently to third parties It keeps a central audit trail of issued certificates
[0142] The invention is not limited to the embodiments described but may be varied in construction and detail. | A method for establishing proof of existence and possession of source digital content, the method comprising the steps of generating a content certificate by calculating a content hash derived from the source digital content; creating code incorporating the content hash and content details, and a certifying body time-stamping and digitally signing the content hash and the content details to create a content certificate; transmitting the content certificate via a secure channel so that the recipient can verify that the certificate came from the certifying body; transmitting a digitally signed file representing the content certificate content details. A tamper-proof audit trail of certification is generated by: calculating a proving hash of a concatenated file of data relating to a plurality of content certificates; publishing the proving hash, and publishing the concatenated file. Existence of content is proved by: verifying certified digital content against the content certificate using hash verification and checking history of public keys from digital identities; and proving prior existence of the content certificate by reference to published proving hashes and historic content hashes without reference to the certifying body. | 6 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to optical fiber. More particularly, the present invention relates to metal-coated optical fiber, and techniques for manufacturing same.
[0002] Optical fiber is typically constructed having a polymer coating, but some applications necessitate the use of metal-coated optical fiber. For example, distributed fiber sensing technology for temperature, acoustic vibration and strain have become popular in oil and gas well monitoring. The well temperature in oil sands or super heavy oil reservoir sometimes becomes more than 300 deg. C. because thermal extraction enhancement is applied frequently. Current polymer coated fiber does not keep its original mechanical properties against such high temperatures. Thus, metal coated fiber is applied for high temperature environment instead of polymer coated fiber.
[0003] Metal coated fibers such as aluminum, copper and gold are commercially available. But all of these fibers have thick metal layers more than 20 micron because dipping methods are applied for their manufacture. In particular, bare fiber is dipped into molten metal during passing coating die filled with molten metal and then frozen on the fiber surface. One disadvantage of these fibers is larger attenuation because thicker coating thickness of around 20-30 micron and thermal contraction by freezing leads to additional loss. For example, a typical loss of copper coated fiber with 125 micron of glass diameter and 20 micron thickness of copper is around 10 dB/km at 1310 nm.
[0004] As an alternative manufacturing method of metal coated fiber, it was reported that a low loss metal coated fiber was made by a plating method. (International Wire & Cable Symposium Proceedings 1991, pages 167-171.) The attenuation of the reported fiber with 125 micron glass and 2.5 micron of nickel layer is 0.7 dB/km at 1300 nm. The structure of metal coated fiber made by plating is described in U.S. Pat. No. 5,093,880, which is incorporated herein by reference for all purposes. But long metal coated fiber made by plating is not yet commercialized due to the difficulty of handling bare fiber. A method of manufacturing metal coated fiber by plating without degrading mechanical reliability is disclosed in application no. PCT/US2014/028151 (published on Sep. 25, 2014 as WO 2014/152896). U.S. Pat. No. 5,093,880 and application no. PCT/US2014/028151 are both incorporated fully herein by reference for all purposes.
[0005] As for the performance of temperature resistance, only loss performance under high temperature was previously described. The bending performance after heat treatment or ductility against high temperature environment was not reported. However, retaining ductility after heat treatment is an important mechanical performance characteristic for downhole cable. In this regard, sensing cable is installed into well repeatedly for logging. Thus, repeated mechanical movement is applied to the sensing cable. And even sensing cable installed permanently has been affected by mechanical vibration and other mechanical movement that occurs during well production and operation. Thus, keeping ductility after heat treatment as well as loss performance are important criteria in the downhole application.
[0006] The present invention recognizes the foregoing considerations, and others, of the prior art.
SUMMARY OF THE INVENTION
[0007] In accordance with one aspect, the present invention provides a method for producing metal-coated optical fiber. This method comprises feeding a length of glass fiber through a first solution bath so as to plate a first predetermined metal on the glass fiber via electroless deposition. The length of glass fiber is then passed continuously from the first solution bath to a second solution bath adapted to plate thereon a second predetermined metal via electrolytic plating such that the optical fiber contacts an electrode only after at least some of the second predetermined metal has been applied. According to exemplary methodology, the length of glass fiber may also be continuously passed from the second solution bath to a third solution bath adapted to plate thereon a third predetermined metal via electrolytic plating. For example, the first and second predetermined metals may be copper with the third predetermined metal being nickel.
[0008] Other aspects of the present invention provide an optical fiber comprising a glass fiber including a core and a cladding. The optical fiber further includes a multi-layer metal coating comprising a first layer of copper, a second layer of copper, and a third layer of nickel. The first layer is applied through an electroless process and the second and third layers are applied through respective electrolytic processes. For example, the combined thickness of the first layer of copper and the second layer of copper may be at least about 5 microns, with the thickness of the first layer of copper being no greater than about 0.5 microns. In addition, the thickness of the third layer of nickel may be at least about 0.5 microns. The optical fiber preferably has a length greater than one meter, such as a length between one and ten kilometers in length.
[0009] Other objects, features and aspects of the present invention are provided by various combinations and subcombinations of the disclosed elements, as well as methods of practicing same, which are discussed in greater detail below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] A full and enabling disclosure of the present invention, including the best mode thereof, to one of ordinary skill in the art, is set forth more particularly in the remainder of the specification, including reference to the accompanying drawings, in which:
[0011] FIG. 1 is a perspective diagrammatic view of a metal-coated optical fiber with layers cut away but without showing individual metal layers.
[0012] FIG. 2 is a table showing characteristics and performance of various examples of metal-coated optical fiber.
[0013] FIG. 3 is a table showing characteristics and performance of various examples of metal-coated optical fiber.
[0014] FIG. 4 illustrates an exemplary process for drawing optical fiber and applying a temporary coating thereto.
[0015] FIG. 5A is a diagrammatic end view of an optical fiber at an intermediate manufacturing step in accordance with the present invention.
[0016] FIG. 5B is a diagrammatic end view of the optical fiber of FIG. 4A at the conclusion of a manufacturing process in accordance with the present invention showing individual metal layers.
[0017] FIG. 6 illustrates an exemplary process for coating optical fiber with metal in accordance with an embodiment of the present invention.
[0018] FIG. 7 is a diagrammatic representation of a bath arrangement that may be used in the process of FIG. 6 in accordance with an embodiment of the present invention.
[0019] Repeat use of reference characters in the present specification and drawings is intended to represent same or analogous features or elements of the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0020] It is to be understood by one of ordinary skill in the art that the present discussion is a description of exemplary embodiments only, and is not intended as limiting the broader aspects of the present invention, which broader aspects are embodied in the exemplary constructions.
[0021] The present invention provides various improvements in metal-coated optical fiber and methods of making the same. Referring now to FIG. 1 , an exemplary metal-coated fiber 10 is illustrated. Fiber 10 includes a glass fiber having a core 12 and a cladding 14 . A metal coating 16 surrounds and contains the cladding/core combination. As will be described more fully below, metal coating 16 may often be formed of a plurality of metal layers applied by a combination of electroless and electrolytic plating. Typically, combinations of electroless copper, electrolytic copper, and electrolytic nickel can be used. The resulting fiber will typically have a desirable combination of low transmission loss and good ductility.
[0022] As further background, the inventors investigated optimal structure of metal coating based on plating method to meet the dual requirements of low loss performance and of keeping ductility after heat treatment. In this regard, short pieces of metal coated fiber were made using carbon coated fiber and tested after heating to find optimal metal structure for meeting the requirements of downhole cable. Carbon coating is often desirable because it will inhibit mechanical degradation by protecting humidity permeation from aqueous solutions of plating and hydrogen permeation generated during plating. One skilled in the art will appreciate, however, that fiber without a carbon coating can also be applicable.
I. Single Layer Structure
[0023] Optical fiber is made of fuzed quartz, which is nonconductive. Even if a carbon layer is coated on glass, the conductance is not sufficient for electrolytic plating due to thickness of less than 100 nm. The first metallic layer should be applied on bare optical fiber by electroless plating regardless of metal kind. We formed nickel phosphorous alloy or copper by electroless plating in accordance with the following process.
Example 1 (Nickel Phosphorous Alloy Electroless Plating)
[0024] Step 1 (Removing temporary coating)—An optical fiber was provided that was coated with carbon coating (specifically, amorphous carbon coating) and secondly coated with temporary plastic coating for mechanical protection which is soluble with water (as described in application no. PCT/US2014/028151). The fiber was dipped into a container with deionized water for five minutes at approximately 60 deg. C., to eliminate the temporary coating and any contamination deposited on the carbon coating.
[0025] Step 2 (Tin attachment)—A carbon coated bare fiber with 125 micron diameter was dipped in the next container with aqueous solution containing 100 ml/L of a tin attachment solution (in this case, 20-330001 “sensitizer” made by Okuno Chemical Industries) for two minutes at approximately 50 deg. C.
[0026] Step 3 —The tin attachment solution (“sensitizer”) deposited on the optical fiber was washed away with water.
[0027] Step 4 (Pd attachment)—The optical fiber coated with the carbon coating was dipped in a container filled with an aqueous solution containing 70 ml/L of an activating reagent (in this case, E20-330003 “Activator” made by Okuno Chemical Industries) for two minutes at approximately 50 deg. C.
[0028] Step 5 —The activating reagent was washed away with water.
[0029] Step 6 (nickel coating formation by electroless plating process)—The optical fiber coated with the carbon coating was dipped in a container filled with nickel phosphorous solutions of 120 ml/L of IPC nicoron GM-NP-M and 70 ml/L of IPC nicoron GM-NP-1 (GM-NP-M and GM-NP-1 made by Okuno Chemical Industries) for 27 minutes at approximately 80 deg. C. As a result, a Ni alloy coating having a thickness of approximately 3 micron was formed on the carbon coating.
[0030] Step 7 —The electroless plating solution deposited on the Ni coating was washed away with water.
[0031] Step 8 —The optical fiber having the Ni coating was then suitably dried.
[0032] The resulting optical fiber comprised the silica based glass optical fiber having a core diameter of 10 micron and cladding having an outer diameter of 125 micron. The amorphous carbon coating coated on the cladding had a thickness of 500 Å, and the Ni coating had a thickness of approximately 3 micron. Namely, an optical fiber coated by the electrically conductive metal, i.e., the Ni layer, having a diameter of approximately 131 micron was formed. The carbon coating and the Ni coating were in good contact with each other, and thus the Ni coating was not peeled from the carbon coating when the optical fiber was bent. The optical fiber with Ni coating was heated inside oven in air atmosphere for 5 hours at 500 degree C. After heating, the optical fiber became brittle. The fiber was broken when the fiber was bent. The same fiber was heated in nitrogen atmosphere for 5 hours at 500 deg. C. and then, a bending test was done. This fiber was also broken by bending.
Example 2 (Copper Electroless Plating)
[0033] In this sample, a copper (Cu) coating was formed on the fiber's carbon coating by the electroless plating process. Accordingly, the steps 1 through 5 were almost the same as Example 1 except for temperature of step 2 and step 4. Specifically, a temperature of 45 degree C. was applied for both steps instead of 50 degree C. The following steps were carried out after step 5.
[0034] Step 6 (copper coating formation by electroless plating process)—The optical fiber coated with the carbon coating was dipped in the a container filled with aqueous copper solutions of 72 ml/L of OPC copper HFS-A, 150 ml/L of OPC copper HFS-M and 4 ml/L of OPC copper HFS-Cnicoron GM-NP-M and 7.3 ml/L of electroless copper R-H (HFS-A, HFS-M, HFS-C, R-H made by Okuno Chemical Industries) for 15 minutes at approximately 45 deg. C.
[0035] Step 7—The electroless plating solution deposited on the Cu coating was washed away with water.
[0036] Step 8—The optical fiber having the Cu coating was dried.
[0037] As a result, a Cu coating having a thickness of approximately 3 micron was formed on the carbon coating. Namely, an optical fiber coated by the electrically conductive metal, i.e., the Cu layer, having a diameter of approximately 131 micron was formed. The carbon coating and the Cu coating were in good contact with each other, and thus the Cu coating was not peeled from the carbon coating when the optical fiber was bent in the diameter of 10 mm. The optical fiber with Cu coating was heated inside oven in air atmosphere for 5 hours at 500 degree C. After heating, the coating of optical fiber was cracked and peeled off. The fiber was broken when the fiber was bent at 10 mm diameter because metal coating did not work for protective coating. According to the results of Examples 1 and 2, initial bending performance was good before heating but it lost ductility after heat treatment in air and fiber was broken by bending. Optical fibers were heated under nitrogen atmosphere and gave bending of 10 mm in diameter. The fiber broke by bending again. But cracked carbon was porous and still soft but was peeled off partially. So the breakage was caused by handing glass fiber without coating.
II. Double Layer Structure
Example 3—(Electroless Copper and Electrolytic Nickel Plating)
[0038] In this sample, a copper (Cu) coating was formed on the carbon coating by the electroless plating process, and a nickel (Ni) coating was formed on the Cu coating by eletrolytic plating. Accordingly, the following steps were carried out after steps 1 through 6 of Example 2.
[0039] Step 6a (Cu coating formation by electroless plating process)—The optical fiber coated with the carbon coating was dipped in a container filled with aqueous copper solutions of 72 ml/L of OPC copper HFS-A, 150 ml/L of OPC copper HFS-M and 4 ml/L of OPC copper HFS-Cnicoron GM-NP-M and 7.3 ml/L of electroless copper R-H (HFS-A, HFS-M, HFS-C, R-H made by Okuno Chemical Industries) for 12 minutes at approximately 45 deg. C. As a result, a Cu coating having a thickness of 2.5 micron was formed on the carbon coating.
[0040] Step 7a—The optical fiber was washed with water.
[0041] Step 8a (Acid activation)—The optical fiber coated with the carbon coating and the Cu coating was dipped in a container filled with acid solutions (Sulfuric acid 100 g/L) for 0.5 minutes at room temperature (RT) for activation.
[0042] Step 9a (Ni coating formation by electrolytic plating process)—The optical fiber coated with the carbon coating and the Cu coating was dipped in a container filled with aqueous solutions (300 g/L of nickel (II) sulfamate tetrahydrate, 5 g/L of nickel (II) chloride hexahydrate and 40 g/L of boric acid) for 9 minutes at approximately 40 deg. C. with 1A/dm2 of current.
[0043] Step 7—The electrolytic plating solution deposited on the Ni coating was washed away with water.
[0044] Step 8—The optical fiber having the Ni coating was dried.
[0045] As a result, a Ni coating having a thickness of 1.7 micron was formed on the Cu coating. Namely, an optical fiber coated by electrically conductive metal, i.e., the Cu and Ni layers, having a diameter of approximately 133 micron was formed. The carbon coating and the Cu/Ni coating were in good contact with each other, and thus the Cu/Ni coating was not peeled from the carbon coating when the optical fiber was bent in the diameter of 10 mm The optical fiber with Cu/Ni coating was heated inside oven in air atmosphere for 5 hours at 500 degree C. The fiber broke by bending after heat treatment under air. But the same fiber passed bending test after heat treatment of 5 hours at 500 deg. C. in nitrogen atmosphere.
Example 4 (Electroless Copper and Electrolytic Copper Plating)
[0046] In this sample, a copper (Cu) coating was formed on the carbon coating by the electroless plating process, and a copper (Cu) coating was formed on the Cu coating by eletrolytic plating. Accordingly, the following steps were carried out after steps 1 through 6 of Example 2.
[0047] Step 6b (Cu coating formation by electroless plating process)—The optical fiber coated with the carbon coating was dipped in a container filled with aqueous copper solutions of 72 ml/L of OPC copper HFS-A, 150 ml/L of OPC copper HFS-M and 4 ml/L of OPC copper HFS-Cnicoron GM-NP-M and 7.3 ml/L of electroless copper R-H (HFS-A, HFS-M, HFS-C, R-H made by Okuno Chemical Industries) for 9 minutes at approximately 45 deg. C. As a result, a Cu coating having a nominal thickness of 1 micron was formed on the carbon coating.
[0048] Step 7b—The optical fiber was washed with water.
[0049] Step 8b (Acid activation)—The optical fiber coated with the carbon coating and the Cu coating was dipped in a container filled with acid solutions (Sulfuric acid 100 g/L) for 0.5 minutes at RT for activation.
[0050] Step 9 (Cu coating formation by electrolytic plating process)—The optical fiber coated with the carbon coating and the Cu coating was dipped in a container filled with aqueous solutions (70 g/L of copper sulfate, 200 g/L of sulfuric acid, hydrochloric acid 50 ml/L, 2.5 ml/L of top lucina 81 HL, and 10 ml/L of top lucina make up (top lucina 81 HL, top lucina make up, made by Okuno Chemical Industries) for 24 minutes at approximately RT with 1A/dm2 of current. As a result, a Cu coating having a thickness of 4.4 micron in total including electroless copper was formed. Namely, an optical fiber coated by electrically conductive metal, i.e., the Cu layer, having a diameter of approximately 134 micron was formed. The carbon coating and the Cu/Cu coating were in good contact with each other, and thus the Cu/Cu coating was not peeled from the carbon coating when the optical fiber was bent in the diameter of 10 mm. The optical fiber with Cu/Cu coating was heated inside oven in air atmosphere for 5 hours at 500 degree C. The fiber broke by bending after heat treatment under air. But the same fiber passed bending test after heat treatment of 5 hours at 500 deg. C. in nitrogen atmosphere. And the surface of metal layer was cracked and peeled off partially.
[0051] The characteristics of four fibers are summarized in Table 1 of FIG. 2 . As can be seen, Example 2 and Example 4 showed no breakage against bending after heat treatment but the coating surface was cracked and glass portion was exposed partially according to the observation of SEM (scanning electron microscope). It is known that nickel phosphorous alloy made by electroless plating changes its brittleness by heat aging (See Wolfgang Riedel, Electroless Nickel Plating). In general, electroless nickel has less ductility than that of electrolytic nickel. Comparing effect of air and nitrogen of heat treatment, nitrogen heat treatment gave less degradation of ductility. It is known that oxidation speed of nickel is lower than that of copper. This was verified comparing Example 3 and Example 4.
[0052] Japanese patent P2011-64746A, incorporated herein by reference in its entirety for all purposes, includes three layer structure of metal coating, namely electroless copper, electrolytic copper, and amorphous nickel. The amorphous nickel described in the patent is made by electroless nickel plating as nickel phosphorous alloy or nickel boron alloy. Amorphous nickel is different from cystalic nickel made by electrolytic nickel plating as pure nickel.
[0053] In order to improve ductility after heat treatment under air, a three layer structure having selected thicknesses of each metal layer can be advantageously employed. For example, according to a preferred embodiment, electroless copper may be coated on the carbon coating as the first metal layer. Then, an electrolytic copper layer may be deposited on the layer of electroless copper. And finally, electolytic nickel may be deposited on the electrolytic copper as an outer surface. Preferably, the thickness of the electroless copper layer may be minimized because the deposit rate of electroless copper is less than that of electrolytic copper. By minimizing electroless copper thickness, process times can be improved. Moreover, the total thickness of copper (including electroless copper and electrolytic copper) is optimized for ductility after heat treatment. The nickel layer is applied to protect oxidation of copper.
[0054] Ductility performance after heating as parameters of copper and nickel thickness is shown in FIG. 3 . Each circle or “X” indicates that metal coated fiber having Cu and Ni of various thickness was made and bending test was done after heating. The test results, as indicated, demonstrate that the structure having more than 5 micron of electrolytic copper and more than 0.5 micron of electrolytic nickel showed good ductility against atmospheric heating of 500 deg. C. for 5 hours.
[0055] As noted above, transmission loss performance, in addition to ductility after heat treatment, is an important characteristic for downhole applications. The inventors fabricated long metal coated fiber for evaluation of transmission characteristics. As an example, metal coating thicknesses of six (6) micron of electrolytic copper and one (1) micron of nickel may be utilized. Referring now to FIG. 4 , long optical fiber having carbon layer and water soluble polymer may be produced using the illustrated apparatus. In this regard, a single mode fiber preform 20 is heated by heater 22 to a suitable temperature (e.g., 2000 deg. C.). The drawn fiber 24 enters carbon coating furnace 26 in line with the drawing furnace. Acetylene or other hydrocarbons are decomposed thermally and amorphous carbon is deposited on glass surface during passing through the chamber. Then, carbon coated fiber 28 goes through coating die 30 for application of water soluble polymer. In one example, the water soluble polymer may be OKS 8049, Nichigo 20% aqueous solution. The coated fiber 32 passes through a curing oven 34 and is taken up into a reel 35 .
[0056] The cross section of the temporary coated optical fiber 32 is shown in FIG. 5A . As can be seen, fiber 32 has a core 34 , cladding 36 , and a carbon coating 38 . The temporary polymer coating, which is applied to facilitate handling during intermediate process steps, is shown at 40 . The temporary coating 40 may desirably have a thickness of about 10 microns in accordance with some preferred embodiments.
[0057] FIG. 5B illustrates the final long optical fiber 42 to be produced. Fiber 42 retains core 34 , cladding 36 and carbon coating 38 . In addition, however, a three-layer metal coating is located on the exterior of carbon coating 38 . As noted above, this metal coating may comprise an electroless copper layer 44 , an electrolytic copper layer 46 , and an electrolytic nickel layer 48 in some presently preferred embodiments. An apparatus and process for producing the long optical fiber 42 will now be described.
[0058] Referring now to FIG. 6 , optical fiber 32 (with water soluble polymer) is stocked, such as on reels 35 . When necessary, a reel 35 of fiber 32 is served for plating. Specifically, temporary coated fiber 32 is paid off from reel 35 as shown. Pulleys 50 , 52 may preferably be provided to determine position of fiber precisely against the input holes of the respective baths. The take-up reel for the finished optical fiber 42 is shown at 54 .
[0059] It will be appreciated that the plating process is similar in some respects to that described in application no. PCT/US2014/028151. For example, during the process before sufficient thickness of metal is applied, bare fiber is exposed to solutions without any contact to hard material. In fact, each of the baths to be described is preferably configured such as shown in FIG. 7 to allow entry and exit of the optical fiber without touching any hard material. As will be described, pulleys 56 and 58 are preferably made of conductor so that they are used for cathodes of electrolytic plating.
[0060] Fiber 32 first encounters bath 60 , which is filled with water for removing the temporary polymer coating. Bath 62 is filled with aqueous solution of tin attachment and bath 64 is filled with aqueous solution of Pd attachment. Baths 66 , 68 , 70 , 72 , and 74 are filled with water for rinsing. Bath 76 contains activation solution and bath 78 is filled with aqueous solution of electroless copper.
[0061] Baths 80 and 82 are filled with electrical copper aqueous solution and electrolytic nickel aqueous solution, respectively. Anode plates 84 and 86 are located inside of respective baths 80 and 82 , and are used for electrolytic plating. When fiber goes through at constant speed, one skilled in the art will appreciate that bath length determines soaking time. The relative length of each bath is thus designed to correspond to relative ratio of soaking times for baths (except for rinsing).
[0062] After passing bath 60 , the fiber's carbon coating is exposed by dissolving the polymer coating. The bare fiber goes through each solution in the baths without contacting hard material due to the overflow design concept shown in FIG. 7 . During bath 78 , electroless copper is deposited on the carbon coating. In general, process time is dominated by electroless copper because the deposit rate of electroless copper is slow. In the system shown in FIG. 6 , however, electroless plating and electrolytic plating are processed in tandem. So the thickness of copper is formed by not only electroless copper in bath 78 but also electrolytic copper in bath 80 before contacting cathode pulleys 56 and 58 . This means the thickness of electroless copper can be reduced as small as possible to give enough conductivity for electrolytic plating. For example, the thickness of electroless copper can be reduced to be less than 0.5 micron because enough thickness of copper, more than 2 micron, is formed by electrical plating before arriving to pulley 56 . As can be seen, the optical fiber reenters bath 80 after passing around pulley 56 for additional electrolytic plating of copper. This plating line is designed to form six (6) micron of copper layer and one (1) micron of nickel layer from the thin electroless copper layer which is formed on the carbon coating. The bath solutions may include formaldehyde bath solutions.
[0063] FIG. 7 illustrates one configuration of an arrangement that can be used in the process of FIG. 6 to ensure that the optical fiber does not contact anything except the water or process solution (depending on which bath). In this case, fiber passes through exits (i.e., fiber inlet and outlet) of a bath where liquid flows out and below the level of liquid. The bath arrangement includes dual cells, an inner cell (vessel) 90 and an outer cell (vessel) 92 . Inner cell 90 contains sufficient liquid such that it flows over from exits at each end (as shown). Outer cell 92 receives the liquid which flows out from inner cell 90 for recirculation. The liquid received by outer cell 92 flows to solution reservoir 94 . A slight pulling tension is preferably applied to the fiber so as to cause straight passing through holes or slits of walls without touching.
[0064] As shown, solution in reservoir 94 is pumped up into inner cell 90 to keep the fiber immersed in the liquid of the cell. It will be appreciated that the fiber will have a tendency to sag between fiber inlet and fiber outlet due to gravity. Because the liquid inlet into inner cell 90 from the pump is located at bottom of the cell, this tends to push the fiber up by the flow of the liquid. The upward force counteracts the sagging due to gravity and prevents the fiber from contacting hard components, such as the bottom or walls of inner cell 90 . The fiber's vertical position will preferably be controlled to keep constant against sag by monitoring position and adjusting the flow rate of the incoming solution, if necessary.
[0065] As result of the described arrangement, optical fiber with carbon coating and six (6) micron of copper coating and one (1) micron of nickel coating was obtained in an example. The transmission loss was 1.4 dB/km at 1310 nm and 1.1 dB/km at 1550 nm. The transmission loss is much improved up to 1/10th of conventional metal coated fiber. The bending test after heating for 5 hrs at 500 deg. C. atmospheric oven showed good ductility.
[0066] Regarding metal coating structure, the three layer structure comprising inner electroless copper layer, electrolytic copper layer, and outer nickel layer was found to be good for heat resistant property in atmospheric environment. This is because copper keeps good ductility even after heat treatment and nickel works as protective coating against oxidation because of its low oxidation speed. From the viewpoint of ductility after heating, pure copper is better than alloyed copper with some impurities. Thus, electroless copper or electrolytic copper should preferably be designed to form copper as pure as possible to get enough ductility. Copper is easily oxidized at high temperature under air atmosphere. But oxidized copper is porous, still soft and will not generally give damage to fiber surface after heating. And thicker copper layer works as a buffer layer against outer layer's stress. On the other hand, oxidization speed of nickel is very slow compared with copper although oxidized nickel becomes hard and brittle. Oxidized nickel is not good for inner layer for its hardness, but a nickel layer is good for outer surface as it serves as an oxidation barrier. Inner copper makes a role of protective layer against mechanical propagation of crack or contact of hard and brittle outer layer of nickel.
[0067] As parametric study of nickel and copper, copper thickness of more than five (5) micron including electroless copper and more than one (1) micron of electrolytic nickel works well under high temperature, atmospheric environment. As increasing thickness of copper or nickel, the transmission loss increases because the thermal stress at interface between glass and metal increases and then it causes microbending loss. So less than 20 micron of metal layer gives better loss performance than conventional metal coated fibers made by metal freezing method.
[0068] The three layer structure is preferably formed by a tandem process of electroless copper plating and electrolytic copper process. The tandem process enables minimizing the thickness of electroless copper because enough thickness for mechanical handling is formed by adding electrolytic copper layer to electroless copper layer. The process time is dominated by the electroless copper for its slow deposit rate compared with electrolytic plating process. This enables enhancement of line speed of production because the fixed length of plating bath and deposit rate limits the process time, that is, plating thickness. The present invention provides a manufacturing method to form enough thickness of metal by adding electrolytic metal deposit to electroless metal deposit tandemly on a optical fiber without contact to hard material until optical fiber contacts with cathode, thus contributing to productivity enhancement.
[0069] While preferred embodiments of the invention have been shown and described, modifications and variations may be made thereto by those of ordinary skill in the art without departing from the spirit and scope of the present invention. In addition, it should be understood that aspects of the various embodiments may be interchanged both in whole or in part. Furthermore, those of ordinary skill in the art will appreciate that the foregoing description is by way of example only, and is not intended to be limitative of the invention as further described in the appended claims. | Method and apparatus for producing metal-coated optical fiber involves feeding a length of glass fiber through a first solution bath so as to plate a first predetermined metal on the glass fiber via electroless deposition. The length of glass fiber is passed continuously from the first solution bath to a second solution bath adapted to plate thereon a second predetermined metal via electrolytic plating such that the optical fiber contacts an electrode only after at least some of the second predetermined metal has been applied. The length of glass fiber may be passed continuously from the second solution bath to a third solution bath adapted to plate thereon a third predetermined metal via electrolytic plating. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention pertains to a method and apparatus for optically accessing a preselected character of a multiplicity of discrete characters contained in an array and more particularly for rapidly accessing the preselected one and providing an image thereof at a location independent of the character accessed.
2. Description of the Prior Art
Standard impact printer systems employ a rotating or translating member that contains one or more sets of the character vocabulary. To access the proper character an instant of time is selected, from the total available cycle time, at which the impact of a hammer transfers the desired character from the rotating or translating member to the print out paper. This approach has been employed to produce an optical printer wherein a light beam is directed to a mask, containing transparencies or templates of the character vocabulary, at at the proper time to illuminate the desired character contained therein. The spatially modulated beam resulting therefrom is focused upon a photoconductive drum member of an electrophotographic copier system wherein the character is rendered visible and transferred to a hard copy paper image. This time-domain accessing of characters requires the light beam, which illuminates the rotating character mask, to be pulsed not only at the proper time to select the desired character but in such a fashion as to hold character blurring within acceptable tolerances. Consequently, the average light pulse duty cycle must include a pulse that is sufficiently brief to provide an instantaneous snapshot of the selected character at an interpulse period, of average duration, that is equivalent to one cycle of the entire vocabulary of characters. To prevent blurring the character motion must be less than five percent. Thus, if the printable vocabulary contains 100 symbols an average light pulse duty cycle of 5 × 10 -4 is required. This duty cycle dictates at peak power level for the pulse system's light source that is 2,000 times greater than that of a light source in an illumination system which could function with a 100 percent duty cycle.
Time domain accessing for optical printing systems as described above exhibit printing speed limitations. A system employing a character reel that rotates at 3600 rpm and carries two vocabulary sets on its circumference has a printing rate of 120 characters per second or approximately 60 lines of printing per minute. To surmount this printing speed limitation a multiplicity of light sources had been employed. Printing speeds of several thousand lines per minute have been achieved by employing one light source for each printing line on a page. This is a brute force approach that is expensive and which results in a short MTBF. Printing speeds of optical printing systems may be increased by replacing the time dimension accessing procedure with a system that randomly positions the beam to access the character mask. Position accessing refers to the procedure whereby stationary array of characters is addressed by altering the direction of the light beam to strike the desired character template. However, in position accessing, the change in light beam direction produced to address each character template, must be subsequently eliminated so that the final beam position for each character accessed remains unchanged.
SUMMARY OF THE INVENTION
The subject invention provides a method and apparatus for rapidly accessing a preselected character symbol generator, from a multiplicity of character symbol generators, and establishes an image of the character symbol, represented by the character symbol generator accessed, at a fixed image position that is independent of the character symbol generator accessed. According to the invention, a light beam from an external source, having a given linear polarization is incident to a birefringent prism along a propagation path associated with the given polarization and is refracted by the prism to propagate along the prism's common path. This polarization vector is oriented at an angle of 45° to the optical axes of an optical quarter wave plate to which the light beam, propagating along the common propagation path, is incident. By virtue of the property of the optical quarter wave plate a right circular polarized wave emerges therefrom and is deflected by a moveable mirror towards a refracting lens which substantially collimates the light beam. This collimated light beam is perpendicularly incident to a flat mirror with a spot size that is determined by a multi-lens telescope having a lens in the path of the beam incident to the birefringent prism and a lens in the common beam path that is interposed between the deflecting mirror and the quarter wave plate. The light beam is reflected from the mirror with a beam waste greater than that of the incident beam and is spatially modulated by the character symbol generator accessed by the moveable deflecting mirror. The spatially modulated light beam, which is again right circularly polarized, is focused by the collimating lens and propagates back along the path towards the deflecting mirror wherefrom it is deflected with left circular polarization to the quarter wave plate. This left circular polarization is connected by the quarter wave plate to a linear polarization with a polarization vector that forms an angle of -45° with the optical axes of the quarter wave plate and is orthogonal to the polarization of the light beam incident to the quarter wave plate from the birefringent prism. From the quarter wave plate, the orthogonally polarized light beam propagates along the common path to the birefringent prism from which it is refracted to propagate along the second propagation path to form an image at a fixed position that is independent of the character symbol generator accessed.
Another embodiment of the invention utilizes an acousto-optic deflector to deflect an incident light beam at an angle corresponding to the character symbol generated to be accessed. The deflected beam is collimated by a collimating lens and is incident to a biprism on one side of the symmetry axis and refracted thereby to illuminate a flat mirror placed immediately behind the character symbol accessed. The mirror reflects the beam towards the half of the biprism on the other side of the plane of symmetry with a beam waste that is greater than the spot size illuminating the mirror. This reflected beam is spatially modulated by the character symbol generator, refracted by the biprism back towards the acousto-optic deflector, and focused by the collimating lens prior to a deflection by the acousto-optic deflector along a given path, that crosses the path of the incident beam, to form an image at a fixed position that is independent of the character symbol generator accessed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an optical schematic diagram generally illustrating one form of the invention.
FIG. 2 is an optical schematic diagram illustrating a preferred embodiment of the invention.
FIG. 3 is an optical schematic diagram of an embodiment of the invention utilizing an acousto-optic vertical deflector.
FIG. 4 is an optical schematic diagram of an emobdiment of the invention illustrating the utilization of a birefringent prism and an optical half wave plate with an acousto-optic deflector to double the vocabulary of the embodiment illustrated in FIG. 3
FIG. 5 is an optical schematic diagram of an embodiment of the invention wherein a two-dimensional deflection system is employed.
FIG. 6 is an optical schematic diagram of an embodiment of the invention illustrating an alternative two-dimensional deflection system to that of FIG. 5.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows, in schematic form, a character accessing system 10 wherein the character is imaged at a position that is independent of the character accessed. The system comprises a beam deflector 11 located at the focal point of a first lens 12, a character mask 13 haveng a multiplicity of character symbol generators, interposed between the first lens 12 and a second lens 14, at the focal point of which a second beam deflector 15 is located. Subsequent to the second beam deflector 15 is a lens 16 and a stationary character image position 17.
A light beam 18, which is used to access a character symbol generator on the character mask 13, is deflected by the beam deflector 11 at an angle θ from the axis 21 of the first lens 12. The deflected beam is collimated by lens 12, at a distance from the axis 21 that is determined by the focal length of the lens and the deflection angle θ and illuminates a character symbol generator 22 on the character mask 13 thereat. This character symbol generator illumination causes a spatially modulated light beam which is representative of the character symbol desired, to be incident to the second lens 14 and focused therefrom to the second beam deflector 15, forming an angle θ' with the axis 23 of the lens 14. Deflector 15 deflects the light beam, which has been spatially modulated by the character symbol generator 22, through lens 16, wherefrom it is focused to the image position 17. Deflectors 11 and 15 may be a galvanometer type such as the General Scanning Company's GO612 and the Minneapolis-Honeywell Company's M25K or an acousto-optic type manufactured by the Soro and Isomet Companies.
Deflector 11 must provide a beam sufficiently broad to fully illuminate each character 22 in the character mask 13. Consequently, the size of each character 22 (C), the size of the deflector 11 (D), the focal length (f) of the lens 12 and the wavelength ( λ ) of the light beam are interrelated, this interrelationship being given by C = 2f λ /D. Additionally, to provide a recognizable character at the character image position 17 each character symbol generator 22 must be decomposed into a multiplicity of resolution elements each of which is considerably smaller than the character size (C). This resolution element size (m) and the focal length (f') of the second lens 14 determines the minimum size of the second deflector 15 (D') which is given by D' = 2f' λ/m. With N resolution elements in each character symbol generator 22, the minimum size (D') of the second deflector 15 is related to the size of the first deflector 11 by D' = N(f'/f)D. Consequently, for D = D', f/f' = N which implies that the angle of deflection with respect to the axis 23 of the second lens 14 is greater than the angle of deflection with respect to the axis 21 of the first lens 12 by a factor N. If the focal lengths are made equal, thus equalizing the angles of deflection, then D'/D = N and the diameter of the second deflector must be N times the size of the first deflector. It is significant to note that the spatial modulation imposed on the beam by the character symbol generator 22 cannot be transmitted through the second deflector 15 unless its aperature is sufficiently large, or alternatively its deflection range is sufficiently large, that it can resolve a number of positions, in terms of the Raleigh criteria, that are equal to the product of the number of characters in the vocabulary times the number of linear resolution elements per character.
Refer now to FIG. 2 which shows, in schematic form, an embodiment of the invention wherein an optical path is folded back on itself so that a single light deflector functions both as a character symbol generator addressing device and as a beam direction restoring device. In FIG. 2, a linearly polarized light beam 25 is incident to a first lens 26, propagating therefrom through a birefringent prism 27 and an optical quarter wave plate 28, to a focusing lens 31 from which a light beam emerges with a predetermined spot size. The beam is then deflected from a mirror light beam deflector 32 to a second lens 33, which refracts the beam to emit a substantially collimated beam that is substantially perpendicular to a character mask 34-mirror 35 combination. This collimated-like beam provides a diffraction limited spot on the character mask-34 which illuminates a character symbol generator thereon addressed by the deflector 32. The character mask 34 is placed immediately adjacent to the mirror reflector 35 and light transmitted through the accessed character symbol generator is reflected from the flat mirror 35, and is retransmitted through the accessed character symbol generator, emerging with a spatial modulation representative of the desired character symbol. Lens 33 performs an imaging function for the spatially modulated beam. From lens 33 to spatially modulated beam is deflected from the deflector 32 and propagates through lens 31, the quarter wave plate 28 and the birefringent prism 27 to be focused at an image position 39 which is independent of the character generator accessed.
Lenses 26 and 31 comprise a telescope which limits the beam waist of the optical beam initially incident to the mirror 35. This limited aperture illumination results in an optical beam, reflected from the mirror 35 which, due to the presence of the character mask 34, exhibits a larger diffraction limited beam waist at deflector 32 than that of the beam incident on the first pass thereto. If n is the number of linear resolution cells per character and N the number of characters on the linear mask array 34, the optical beam on the first deflection from deflector 32 must be n times smaller than the aperature of the deflector 32, and to provide the required character resolutions, the deflector 32 must be capable of resolving at least the number of discrete beam positions equal to the product of the number N of characters on the linear mask array 34 times the number of linear resolution elements n per character.
The linear polarized beam emitted from lens 26 may be refracted from the birefringent prism 27 to be incident to the quarter wave plate 28 with a polarization angle of 45° relative to the optical axes thereof. As is well known in the art, this incident linear polarized light beam may be arranged to be emitted from the quarter wave plate 28 as a right circularly polarized beam. After being reflected from the character mask 34-mirror 35 and twice by the deflector 32, the circular polarized beam is returned to the quarter wave plate 28 and emerges therefrom with a linear polarization angle of -45° relative to the optical axes thereof (i.e., orthogonal to the polarization of the beam initially incident to the birefringent prism 27 from the lens 26). This orthogonally polarized beam is then incident to the birefringent prism 27 wherefrom it emerges in a fixed direction that differs from that of the beam incident to the birefringent prism 27 from the lens 26 and provides an image at a fixed position 39 that is independent of the character accessed.
Refer now to FIG. 3 wherein is shown, in schematic form, a modification of the embodiment of FIG. 2. In FIG. 3, which is shown in vertical cross-section, An optical beam 36, from an external source (not shown) propagates through lenses 37a and 37 to an acousto-optic deflector 41, which is oriented to provide optical beam deflections in the horizontal plane. This deflection is utilized to address a character symbol generator on a one-dimensional reflecting character array 42, which extends along the horizontal plane. It is to be noted that proper operation of the acousto-optic deflector 41 requires that the light beam propagating therethrough be substantially collimated. After deflection by the acousto-optic deflector 41, the beam propagates through lens 38, which in combination with the lenses 37a and 37 form a telescope to provide a predetermined beam waist for the beam emerging from lens 38. The beam then propagates through lens 43, emerging therefrom as a substantially collimated beam, and is refracted in the vertical plane by biprism 44 to illuminate the addressed character on the linear array reflecting character mask 42. The light beam incident from biprism 44 is reflected from the linear array reflecting character mask in a manner similar to that of the reflection from the mirror 35-character mask 34 combination of FIG. 2 previously described. Biprism 44 and lens 43, which performs an imaging function for the spatially modulated beam, refract the beam reflected from the character mask-mirror combination 42 along a path in the vertical plane that is in a direction other than the direction of the incident beam 36. The beam so refracted propagates through lens 38 to the acousto-optic deflector 41, wherein it experiences the same deflection as the beam incident from lens 37a. The reflected beam after deflection by the acousto-optic deflector 41 provides an image of the accessed character at a fixed position 45 that is independent of the character accessed. In the apparatus described above, lenses 37 and 38 possess different focal lengths. This permits the character size on the character mask to be selected by adjusting the distance between the lens 38 and the linear array reflecting-character mask 42 while maintaining the beam size at the acousto-optic deflector at a predetermined dimension.
A modification of the invention shown in FIG. 3 is illustrated in FIG. 4. In FIG. 4, only the modified portion of the apparatus of FIG. 3 is shown. The modified section of the apparatus comprises the acousto-optic deflector 41, the lens 38, a switchable electro-optic half-wave plate 50, a birefringent prism 51, the collimating lens 43, the biprism 44 and the reflecting character mask 42. The incident beam 36 to the acousto-optic deflector 41 is deflected therein, propagates through lens 38 and is incident to the electro-optic half-wave plate which switchably rotates the polarization of the incident beam 36 to the orthogonal polarization when activated. With the switchable half-wave plate 50 unactivated, the incident beam propagates through the birefringent prism 51, being refracted thereby, in the vertical plane, at the refracting angle for the incident polarization. The vertically deflected beam then propagates through the collimating lens 43, wherefrom it is refracted to the accessed character by means of the biprism 44. The spatially modulated beam reflected from the reflecting character mask 42 propagates through the birefringent prism 51, the switchable electro-optic half-wave plate 50 and the remaining elements of the system to be focussed at the image position in a manner similar to that previously described. When the polarization switch 51 is activated, the incident beam 36 propagates therefrom with a polarization that is orthogonal to that of the incident beam when the switch is unactivated. This orthogonally polarized beam is incident to the birefringent prism 51 and is refracted therefrom at an angle other than that of the unrotated polarized beam. Propagation of the rotated polarized beam continues through the lens 43 and the biprism 44 to access a character positioned above the character accessed by the unrotated polarized beam. Reflection from the reflecting character mask 42 to a focused image at the image position for the rotated polarized beam is identical to that of the unrotated polarized beam, thus the vocabulary of the system is doubled by the addition of an electro-optic half-way plate 50, which provides switchable polarizations, and a birefringent prism 51. It should be clear to those skilled in the art that the vocabulary may be further extended with this technique by using additional combinations of polarization switches and birefringent prisms, with n combination extending the system vocabulary by a factor of 2 n .
Two rotatable reflectors are utilized in the embodiment of the invention illustrated in FIG. 5. The structural arrangement is the same as in FIG. 2 with the exceptions that the deflector 32 is replaced by two deflectors, one for deflecting the beam horizontally, the other for deflecting the beam vertically and the linear array reflecting-character mask comprising the character mask 34 and the mirror 35 is replaced by a reflecting character mask having an mxn array of character symbol generators in which m rows may be substantially perpendicular to the n columns. The operation is similar to that of the device of FIG. 2. An incident beam 25 propagates through lens 26 to a birefringent prism 27 from which it passes through a quarter-wave optical plate 28 and lens 31. From lens 31 the beam is horizontally deflected at the proper horizontal angle for accessing the desired character by rotating deflector 52 which is positioned at an angle with respect to the vertical to deflect the beam to deflector 53. Deflector 53 is rotatable to vertically deflect the beam at the proper vertical angle for accessing the desired character symbol generator. Thus, the beam has been deflected horizontally and vertically to access a character symbol generator of the array of character symbol generators on the reflecting-character array mask 54. The beam reflected from the reflecting-character array mask 54 is then deflected from deflector 53 to deflector 52 from which it propagates through lens 31 to the optical quarter-wave plate 28 wherein the polarization is rotated as previously described, and refracted from the birefringent prism 27 to the character image position 29, all as previously described for the apparatus of FIG. 2. It should be obvious to those skilled in the art that the order of deflection is not critical and that the deflectors 52 and 53 may be interchanged to provide an initial vertical deflection and a subsequent horizontal deflection to access the character symbol generator desired.
Another embodiment utilizing vertical and horizontal deflectors is illustrated in FIG. 6, wherein is shown an accessing beam 55 which emerges from a lens 59 to which an external linear polarized beam is incident. The accessing beam 55 propagates through a birefringent prism 56, an optical quarter-wave plate 57, and a lens 58 to a vertical deflector 61. The effect on the beam 55, as it propagates through these elements is as previously described. The beam incident to deflector 61 is vertically deflected therefrom to lens 62, being focused on the vertical axis thereof and refracted therefrom to illuminate a horizontal deflector 63. After the deflection from the horizontal deflector 63 the beam propagates through lens 64, which with lenses 59 and 58 comprise a telescope which limits the beam waist of the beam incident to lens 65. Lens 65 collimates the beam incident thereto and the collimated beam propagating therefrom illuminates the accessed character symbol generator in the reflective character array mask 66. The spatially modulated beam reflected from the reflecting-character array mask 66 propagates through the lens 65, which performs an imaging function for the spatially modulated beam, and lens 64 to deflector 63 wherefrom it is deflected to be focused on the vertical axis of lens 62, whereat an inverted image appears. The spatially modulated beam emerging from lens 62 is deflected from deflector 61 to lens 58, propagating therethrough to the optical quarter-wave plate 57, wherein a 90° polarization rotation occurs. The polarization rotated beam, emerging from the optical quarter-wave plate 57, propagates through the birefringent prism 56 from which it is refracted, at an angle other than the angle of incidence of the incident beam 55, to a fixed imaging position 67. It should be apparent to those skilled in the art that the order of deflection of the optical beam is not critical and that the horizontal and vertical deflectors 61 and 63 may be interchanged.
While the invention has been described in its preferred embodiments, it is to be understood that the words which have been used are words of description rather than limitation and that changes may be made within the purview of the appended claims without departing from the true scope and spirit of the invention in its broader aspects. | A method and apparatus for rapidly changing the spatial modulation imposed on a stationary light beam to conform to a preselected one of a multiplicity of discrete character symbols. Automatic orientation tracking is provided which establishes a fixed direction for the spatially modulated light beam that is independent of the character accessed and provides a fixed position for the character image. The technique may be employed in electrographic high speed printers and has particular utility when used with standard character generating template masks for character generation, though it is also effective when employed with a holographic generating mask array. | 1 |
BACKGROUND OF INVENTION
This invention relates to an improved electric motor power assist system and more particularly to an improved method and device for detecting the manually inputted drive force to the system.
A wide variety of types of systems have been proposed wherein a manual force is assisted by an electric motor. In many of these types of systems, the amount of electric motor assist provided is related to the degree of manual force applied, among other things. Therefore, the mechanisms that operate on this principal generally require some form of manual force measuring device.
This is normally done by providing some form of lost motion connection in the connection between the element to which the manual force is applied and the thing to be operated. The manual force application is measured by determining the amount of lost motion that occurs. Thus, the sensors that operate on this principal require the addition of the lost motion connection to the mechanical transmission for coupling at least the manual force applying device to the load which is driven. This makes it difficult to embody the electric power assist in conventional mechanisms merely through the use of an added electric motor or the assist.
It is, therefore, a principal object to this invention to provide an improved force sensor arrangement for an electrically assisted, manually operated device and more particularly to an improved sensor for sensing the manual force applied without necessitating a lost motion connection.
For example, in one type of device, there is employed a planetary transmission which produces relative movement in response to the lost motion and this planetary transmission then drives a force sensor. Obviously, this not only complicates the system and adds to its costs, but also makes it difficult to apply the system to conventional non-assisted mechanisms.
In another type of arrangement, the lost motion is measured by a pair of cylindrical cams which are held in contact with each other by a spring and relative movement occurs when the manual force is applied. The degree of manual force is measured by measuring the degree of relative movement. Again, this type of device adds to the costs and complexity of the system and makes it difficult to incorporate into conventional non-assisted mechanisms. In addition, the accuracy of these devices is dependent upon maintaining a consistent degree of lost motion for a given force input which requires bearings and lubrication and also which can be adversely effected by temperature changes.
It is, therefore, a still further object to this invention to provide an improved force sensor for an electric power assisted system wherein lost motion is not necessary in order to measure the applied force.
As noted above, temperature variations can result in variations in the amount of assist provided in response to a given input force. Even if lost motion is eliminated, this can still present some problems. It is, therefore, a further object of this invention to provide an electric power assisted system in which temperature variations will not adversely effect the performance.
The type of power assist mechanisms previously employed have not lent themselves to applications where such assist is desirable. For example in winding drums such as fishing reels power assist is desirable, but not possible with the power assist mechanisms previously employed. It is, therefore, a still further object of this invention/n to provide a compact power assist mechanism that is compact enough for such applications.
SUMMARY OF INVENTION
A first feature of this invention is adapted to be embodied in an electrically assisted, manually powered unit. The unit includes a manual drive element receiving a manual input force from an operator, an electric motor for providing an assist force, a transmission arrangement for receiving a driving force from the manual drive element and the electric motor and driving the unit. A force sensor senses the manual force applied to the manual drive element and delivers an output signal indicative of the manual force. A control controls the operation of the electric motor. The control has a sensor input stage receiving the signal from the force sensor and a logic for determining the operation of the electric motor from at least the signal from the force sensor. The force sensor provides the force signal without necessitating any significant displacement of a component thereof.
Another feature of the invention is adapted to be embodied in an electrically assisted, manually powered unit. The invention in accordance with this feature includes a manual drive element receiving a manual input force from an operator. An electric motor for providing an assist force is also used. A transmission arrangement receives a driving force from the manual drive element and the electric motor for driving said unit. A force sensor senses the manual force applied to the manual drive element and delivers an output signal indicative of the manual force. A control controls the operation of the electric motor. The control has a sensor input stage receiving the signal from the force sensor and a logic for determining the operation of the electric motor from at least the signal from the force sensor. The force sensor includes a first electrical device providing a signal indicative of applied force. A second electrical device capable of providing a signal indicative of applied force is also employed. The manual force is applied only to the first electrical device. The first and the second electrical devices are positioned in proximity to each other so as to experience the same temperature. Finally, a circuit connects the first and the second electrical devices to provide a temperature compensated signal to the sensor input stage of the control.
A third feature of the invention is adapted to be embodied in a an electrically assisted, manually powered reel. The reel includes a manual drive element receiving a manual input force from an operator, an electric motor for providing an assist force, a transmission arrangement for receiving a driving force from the manual drive element and the electric motor and driving the reel. A force sensor senses the manual force applied to the manual drive element and delivers an output signal indicative of the manual force. A control controls the operation of the electric motor. The control has a sensor input stage receiving the signal from the force sensor and a logic for determining the operation of the electric motor from at least the signal from the force sensor.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a side elevational view of an electric power assisted bicycle constructed in accordance with a first embodiment of the invention.
FIG. 2 is a partially schematic block diagram showing the components of the drive and power assist system.
FIG. 3 is an enlarged cross sectional view taken though the axis of rotation of the driving wheel and shows the force sensor arrangement as well as the assist motor.
FIG. 4 is an exploded perspective view showing the force sensor and its actuating mechanism.
FIG. 5 is a schematic electrical diagram of the force sensor and shows how temperature compensation is effected.
FIG. 6 is a cross sectional view taken through the crank mechanism of a power assisted bicycle constructed in accordance with a second embodiment of the invention and shows the force sensor associated therewith.
FIG. 7 is a cross sectional view taken through a manually rotated electric motor assisted winding drum constructed in accordance with a third embodiment of the invention.
FIG. 8 is a cross sectional view taken through the axle of a wheel of a wheelchair having an electric motor assist in accordance with a fourth embodiment of the invention.
FIG. 9 is a cross sectional view taken through the steering shaft of an electric motor power assisted steering mechanism in accordance with a fifth embodiment of the invention.
FIG. 10 is a cross sectional view taken along the line 10 — 10 of FIG. 9 .
FIG. 11 is an enlarged view looking in the direction of the arrow 11 in FIG. 10 and shows the connection for loading the sensor.
DETAILED DESCRIPTION
Referring now in details to the drawings and initially to the embodiment of FIGS. 1 through 5 and initially primarily to FIG. 1, a manually operated electric power assisted unit in the form of a vehicle is shown and indicated generally by the reference numeral 21 . In this embodiment, the vehicle is in the form of a bicycle having a tubular frame assembly, indicated generally by the reference numeral 22 .
A front wheel 23 is dirigibly supported by a head pipe 24 of the frame assembly 22 and is steered by a handle bar assembly 25 in a well known manner.
A seat 26 is adjustably supported by a seat pipe 27 of the frame 22 for accommodating a seated rider in a well known manner. At the bottom of the seat pipe 27 , is provided a bracket 28 on which a crankshaft 29 is rotatably journaled in a well known manner. Pedals 31 at the ends of the crank arms of the crankshaft 29 are operated by a rider seated on the seat 26 to drive a driving sprocket 32 .
The driving sprocket 32 , in turn, drives a chain 33 which, in turn, drives a driven sprocket 34 (FIG. 3 ). The driven sprocket 34 transmit the drive to a rear wheel 35 that is journeyed at the rear end of the frame assembly 22 via a drive arrangement, indicated generally by the reference numeral 36 and which is shown in most detail in FIG. 3 .
Still referring to FIG. 1, the drive assembly 36 includes an electric assist motor which receives electrical power from a battery 37 that is carried by a battery box 38 at a rear portion of the frame assembly 22 forwardly of the rear wheel 35 .
Before describing the drive assembly 36 in detail by reference to FIG. 3, the general relationship will be described first by reference to the schematic view of FIG. 2 . As seen in this figure, the drive assembly 36 is comprised of a one-way clutch 39 which, in this specific embodiment, is interposed in the connection between the driven sprocket 34 and the rear wheel 35 . This one-way clutch in turn transfers the drive to the rear wheel through a hub case 41 . A pedal force detector 42 is interposed in this transmission relationship in a manner to be described. It should be noted, however, that unlike the prior art constructions, the pedal force detection device 42 does not require lost motion for its operation. Hence, a much simpler detector can be employed and the basic driving arrangement and hub construction can be generally conventional and embodied in a conventional housing.
In addition to the manual force transmitted to the rear wheel 35 there is also provided a selective power assist from an electric motor, indicated schematically at 43 in FIG. 2 . This electric motor 43 assists the drive of the hub case 41 in a manner which will be described in more detail by reference to FIG. 3 .
The electric motor 43 has electrical power supplied to it from the battery 37 via a controller 44 . The controller 44 may of any type well known in this art and basically operates on the principal that the amount of electric motor assist is proportional to the force applied by the rider applied to the pedals 31 as determined by the pedal force detector 42 . The controller 44 may also operate so as to provide a varying power assist that is greater at lower speeds and decreases as speed of the vehicle and specifically the rear wheel drive 35 increases. Of course, those skilled in the art will readily understand how the invention can be utilized in conjunction with various types of control arrangements. Also to state again, although this embodiment describes the invention in connection with a vehicle such as a bicycle, but as will become apparently from the following description the invention can be utilized with a wide variety of types of manually operated units in which electric power assist is desirable.
Referring now in detail to FIG. 3, the hub case 41 is comprised of a first generally cup-shape portion 45 that defines a cavity in which the electric motor 43 is positioned in a manner to be described. This cavity is closed by a cover plate 46 of the hub case 41 which completes its assembly. These pieces define flanges 47 and 48 on which the spokes of the rear wheel 43 are joined in a manner well known in the art.
This hub case 41 is rotatably journalled on the frame assembly 22 . This journaling is provided by a first bearing 40 that cooperates with an extension 49 that is formed of an outer housing 51 of the motor 43 . The extension 49 terminates in an axle 52 that is fixed in a known manner to the bicycle frame 22 . At the opposite side thereof, the hub case 41 is journaled on a stub axle shaft 53 . This journaling is provided by a ball bearing assembly 54 contained within a cylindrical extension 50 of the hub case end closure 46 .
The driven sprocket 34 is connected via the one-way clutch 39 to an outer member 55 of a helical spline connection provided by balls 56 trapped in the helical splines formed in the inner portion of the member 55 and the outer surface of the projection 50 of the hub case closure plate 46 . This helical connection provided by the balls 56 has a slight skew so as to create an axial force on the hub case 41 and specifically the end plate 46 thereof under the influence of driving forces. As will become apparent later, this force is measured and provides the signal to the pedal force detector 42 which, in this embodiment, is comprised of a magneto-strictive sensor 42 mounted in manner to be described.
The electric power assist from the electric motor 43 is transmitted to the hub case 41 via a planetary transmission, indicated generally by the reference numeral 57 . This transmission includes a sun gear 58 which is affixed to the output shaft of the electric motor 43 . This sun gear 58 is enmeshed with the larger diameter gear portions 59 of three planet gears (only one of which is shown in FIG. 3) that are circumferentially spaced and are journalled on a planet carrier 61 . Smaller diameter portions 62 of these planet gears are enmeshed with a ring gear 63 which is associated with the cover plate 46 and is mounted to the cover plate. To this end, the ring gear 63 is connected to a mounting member 64 via a one-way clutch 65 . The mounting member 64 is connected to the hub case cover 46 via an overload release connection 66 which will release upon excessive loading to prevent damage. Of course, the described transmission is only one of many types that may be utilized to transmit drive from the electric motor 43 to the rear wheel 35 .
The arrangement for transmitting the degree of manual driving force to the pedal force detector 42 will now be described by primary reference to FIGS. 3 and 4. It has been noted that the helical spline connection provided by the balls 56 causes an axial force on the hub case 41 in response to the driving force. A water tight seal 67 is provided between the end of the hub case cover 46 and the member 55 . The member 55 is abutingly engaged with a force taking ring 68 , as best seen in FIG. 4, and specifically with three outwardly extending tab portions 69 thereof. These tabs portions 69 are received in slots 71 formed in an opening of the hub case cover plate 46 so as to hold them against rotation.
The force taking ring 68 , in turn, bears against a thrust bearing 72 which, in turn, engages a retainer 73 . This, in turn, engages a cross piece 74 that has a pair of arm portions that are also retained in the opening 71 and thus held against rotation. This cross piece 74 is engaged with a detector portion 75 of the magneto-strictive sensor 42 . The sensor 42 is, in turn, mounted on an extension 76 of the cover of the motor 43 . It should be noted that driving thrust in one direction is resisted by the connection to the sensor 42 . Driving thrust in the event the pedal rotation is reversed, is taken by end portions 77 of the extension 50 of end cap 46 with a thrust member 78 that is fixed relative to the axle shaft 53 .
In accordance with temperature compensating features of the invention, a dummy sensor 42 a is mounted at one side of the sensor assembly 42 and is provided in the electrical circuit as will be described by reference to FIG. 5 to provide temperature compensation. Referring now to FIG. 5, the electrical connection for the pedal force detector 42 will be described along with this temperature compensation.
A bridge circuit is formed between the sensor 42 and the dummy sensor 42 a and a pair of resistors R 1 and R 2 . These the outputs are connected to an amplifier 79 that outputs a temperature compensated signal because of the unbalance voltage between the output terminals of the sensor 42 and the dummy sensor 42 a , that receives no load. The amplifier 79 outputs its signal to the controller 44 as seen in FIG. 2 so as to provide the pedal force signal without necessitating any significant movement of the components and thus, avoids the lost motion connections of the prior art.
Thus, from the foregoing description, it should be readily apparent that the utilization of the structure shown in this embodiment necessitates no changes in the basic structure of the bicycle frame and merely requires the incorporation of the assist mechanism within the hub case of the driven wheel. Although the pedal force detector is positioned at the connection of pedal force to the driven sprocket, a similar arrangement could also be employed at the driving sprocket 32 adjacent the frame bracket 28 without any other change to the basic frame assembly of the vehicle 21 . Such an embodiment is shown in FIG. 6 and will now be described by reference to that figure. The crankshaft, indicated by the reference numeral 101 in this embodiment, is supported in the frame bracket 28 by means of a pair of transversely spaced ball bearings 102 .
The driving sprocket, indicated here at 103 , is connected by means of fasteners 104 to an outer element 105 of a helical spline connection to the crankshaft 101 . This helical spline connection includes a plurality of balls 106 . When a rotational force is exerted on the driving sprocket 103 this force is transmitted to the spline outer element 105 and the balls 106 in the helical spline place an axial force on the outer element 105 tending to move it toward the left.
A series of circumferentially spaced coil springs 107 press against a thrust plate 108 , which in turn, acts against a force transmitter 109 that is engaged with the contact arm 111 of a magnostrictive sensor 112 . As with the previously described embodiment, the magnostrictive sensor 112 is in a circuit with a dummy sensor 112 a that is mounted in proximity to it and which is in a bridging circuit to provide the force signal to the controller as with the previously described embodiment.
The thrust exerted on the drive sprocket 103 by rotational movement of the crankshaft 101 in the opposite direction is resisted by a thrust plate 113 fixed on the opposite side of the crankshaft 101 and adjacent the drive sprocket 103 .
In the two embodiments as thus far described, the invention has been described in conjunction with an electric power assist for a manually powered bicycle. FIG. 7 shows another embodiment of the invention that is embodied in a manually powered reel or drum such as a fishing reel that is provided with an electric power assist. This reel mechanism is indicated generally by the reference numeral 151 .
The reel includes an outer housing that is comprised of a central member 152 closed at its opposite sides by end closures 153 and 154 . A reel drum 155 is affixed, by means of a fastener 156 to one end of a reel shaft 157 . This reel shaft 157 is journalled in the housing member 152 by means of a pair of spaced ball bearings A crank arm 159 is fixed to the opposite end of the crankshaft 157 from the drum 155 for rotating the drum 155 manually so as to wind a line or the like on it.
An electric assist motor, indicated generally by the reference numeral 160 , is mounted within the housing. The electric motor 160 has an output shaft 161 that is journalled by a pair of ball bearings 162 carried by the end plate 153 and main housing member 152 . One end of the electric motor output shaft 161 is formed with an integral pinion 163 which drives a reduction gear 164 . The reduction gear 164 is engaged with a further reduction gear 165 that is fixed by means of threaded fasteners 166 to an outer member 167 of a helical spline connection to the crankshaft 157 . This connection with the crankshaft 157 includes balls 168 .
When a manual force is exerted on the crank handle 159 to turn the crankshaft 158 , to take up a line on the drum 155 , a axial force will be exerted because the spline connection of the outer member 167 . This places a force on a thrust member 168 , which is in turn, engaged with a thrust plate 169 . The thrust plate 169 is engaged with the contact 171 of a magnostrictive sensor 172 .
This sensor 172 is provided in a bridged resistor circuit with a controller as with the first described embodiment along with a dummy sensor 172 a to provide temperature compensation. Thus, again the force is sensed without necessitating a lost motion connection and without requiring any significant movement for actuating the sensor.
When the crank handle 1159 is turned in the opposite direction, the thrust in this direction is taken by a thrust washer 173 affixed to the crankshaft 157 on the opposite side from the sensors 172 and 172 a.
A one-way clutch, not shown, may be interposed in the connection between the electric motor driven gear 165 and the member 167 of spline connection so as to permit rotation in the opposite direction without driving the electric motor shaft 161 under this condition.
FIG. 8 shows another embodiment of the invention that utilizes an electric power assist mechanism similar to those shown in FIG. 7 but, in this instance, applied to drive a wheel of a wheelchair which is shown only partially and indicated generally by the reference numeral 201 . The wheelchair wheel is indicated at 202 and has associated with it a passenger operated hand wheel 203 with which the operator may rotate the wheelchair wheel 202 . Threaded fasteners 204 connect the hand wheel 203 to the wheelchair wheel 202 .
The wheelchair wheel 202 is affixed to one end of a shaft, which shaft is indicated by the same reference numeral 157 as the crankshaft in the embodiment of FIG. 7 since the electric motor assist and the sensor arrangement for it are the same as that shown in that figure. For this reason, like components have been identified by the same reference numerals as applied in FIG. 7 and a further description of them in this embodiment is not believed to be necessary to permit those skilled in the art to practice the invention. However the housing assembly comprising the housing member 152 and its end closures 153 and 154 are affixed in any desired manner to the frame of the wheelchair 201 , thus simplifying the addition of the electric motor assist to conventional wheelchair constructions.
FIGS. 9 through 11 show a still further embodiment of the invention that is adapted to be employed in an electrically assisted, manually operated, steering system for a vehicle, shown partially and indicated generally by the reference numeral 251 . This steering mechanism 251 includes a manually operated steering shaft 252 that is journalled within a housing assembly 253 by means of spaced apart ball bearings 254 .
At the lower end of the steering shaft 252 , there is provided a short stub shaft 255 to which the steering shaft 252 is connected by means of a pin connection embodying a pin 256 . The lower end of this shaft 255 has a pin connection provided by a pin 257 to a steering shaft 258 of the vehicle which is connected to the dirigible vehicle wheels in any known type manner.
For power assist of the steering, there is provided an electric steering assist motor, indicated generally by the reference numeral 259 , which has an output shaft on which a worm gear 261 is affixed. This worm gear 261 is engagement with a worm wheel 262 fixed to the steering shaft 258 for providing power assist.
In this embodiment, the electric assist motor 259 is a reversible electric motor and power assist is given when the steering shaft 252 is rotated in either direction and an appropriate force applied thereto. The steering force sensor arrangement, indicated generally by the reference numeral 263 , includes an outer spline connection member 264 which has a helical spline connection with the lower end of the steering shaft 252 by means that include a plurality of balls 265 .
As may be seen in FIGS. 10 and 11, the pin 256 passes through an opening 266 in the lower end of the steering shaft 252 that is elongated so as to provide some clearance in the direction of the rotational axis of the steering shaft 252 for roller members 267 that are carried on the ends of the pin 256 . Coil compression springs 268 are carried in the member 264 and bear against upper and lower thrust members 269 and 271 , respectively. These members 269 and 271 , in turn, act upon bearing plates 272 and 273 which are engaged with the contact elements 274 of upper and lower magnostrictive sensors 275 and 276 .
Since power assist is required in both directions, the sensors 275 or 276 will be activated in response to the steering force inputted to the steering shaft 252 depending upon the direction of rotation. These sensors 275 and 276 are placed in circuits that include a dummy sensor 277 for temperature compensation as with the previously described embodiment. Thus, a compensated output will be outputted to the controller for providing the desired degree of power assist in accordance with any desired strategy.
Thus, from the forgoing description it should be readily apparent that the number of embodiments disclosed each provides very effective force sensors for sensing the manual input force for control of electric power assist in a wide variety of devices. Since the sensors require no significant movement, no lost motion is present in the system and incorporation of the device in the desired unit is simplified with out changing the basic construction of the device which is to be power assisted. Although all of the embodiments illustrated employ magneto-strictive sensors for sensing force, other types of force rather than motion detecting sensors such as strain gauges can be employed for sensing the force generated through the helical spline connection. Of course, the foregoing description is that of preferred embodiments of the invention and various changes and modifications may be made without departing from the sprit and scope of the invention, as defined by the appended claims. | Several embodiments of electric power assisted manually operated devices wherein the manual input force is sensed by a sensor that does not require lost motion connections and significant movement in order to determine the force applied. Also a compact drive is disclosed that permits the application to winding drums such as fishing reels. In addition a simplified temperature compensation system for the sensor is employed. Thus, the arrangements can be easily utilized with conventional structures with minimum change. | 8 |
BACKGROUND OF THE INVENTION
1. Technical Field
This invention relates to a dish draining device that is arranged to support dishes, cutlery and other kitchen utensils in a position for gravity draining and air drying.
In particular, this invention relates to a dish draining device that may be fixedly attached to a wall, or may be mounted upon a stand that is placed on a counter top or other flat surface.
2. Background Art
The dish draining device of this invention is an improvement upon the device that is described and claimed in the inventor's previous U.S. Pat. No. 4,756,582. A variety of other devices for the same purpose are known in the art, including those disclosed in U.S. Pat. Nos. 3,258,127, 2,852,030, 2,635,027, 2,538,223 and 2,070,826. However, none of those prior art devices disclose the structural and design features that are provided by this invention.
SUMMARY OF THE INVENTION
The dish draining device of this invention includes a backsplash panel having a forwardly extending drip tray at the bottom thereof to catch water that drains from dishes and utensils held by the device to dry. The panel is secured to a stand, a wall, or other vertical surface by a pair of top-grooved dowels which attach to the surface and pass through openings provided in the panel. A wire frame having a generally rectangular perimeter element corresponding in size and shape to the panel includes downwardly opening, arcuate brackets that are sized to matingly fit within the dowel grooves so that the brackets both directly support the frame and also lock the frame and panel onto the support dowels. Racks to hold plates, bowls, glassware, cutlery and other utensils are mounted upon and supported by the frame. The device is easy and convenient to mount and assemble, takes up a minimum of kitchen counter space, and can easily be disassembled for cleaning.
Hence, it is an object of this invention to provide an improved dish draining device as compared to the inventor's prior device and those other units known in the art for the same purpose.
Other objects and advantages will become apparent from the following drawing figures and the description of preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a perspective of the dish draining device of this invention mounted upon a stand that rests upon a flat surface;
FIG. 2 is a perspective view of the backsplash panel and its associated catch basin;
FIG. 3 depicts the main frame member of the device;
FIG. 4 is a view of a free standing support member for the dish draining device;
FIG. 5 is a detail view of a portion of the support member of FIG. 4;
FIG. 6 is a view of a mounting pod for securing dish draining device of FIG. 1 to a wall or other vertical surface;
FIG. 7 is a cross-sectional view of a mounting boss;
FIG. 8 depicts a holding rack for glass ware that is fixed to the main frame member at one side thereof;
FIG. 9 is a perspective view of a plate holder rack that is detachably mounted to the main frame member;
FIG. 10 depicts a support for a removable water tray which provides a reservoir for the catch basin that is depicted in FIG. 2;
FIG. 11 is a perspective view of the removable water tray;
FIG. 12 is a perspective view of a removable rack that fits atop the backsplash panel;
FIG. 13 is a perspective view of a bowl clip that mounts onto the top of the backsplash panel;
FIG. 14 is a perspective view of a utensil holder; and
FIG. 15 is a perspective view of a cutlery basket that is held above the catch basin by the plate rack holder that is shown in FIG. 9.
DETAILED DESCRIPTION OF THE INVENTION
Referring first to FIG. 1 of the drawing, the dish draining device of this invention is shown generally at 10. Device 10 includes a backsplash panel 20, which is shown in greater detail in FIG. 2, and a main frame member 40 which is shown separately in FIG. 3. Backsplash panel 20 includes a flat back plate 21 having a forwardly extending drip tray or catch basin 22 that is arranged to collect water draining from dishes and utensils held by device 10 to dry. The bottom of basin 22 is provided with a gradual slope toward a central drain 23 so that water collects in a removable water tray 24 which is held in place by tray support bracket 25. Support bracket 25 is depicted separately in FIG. 10. Alternatively, a small hose or conduit 27 leading to a sink or other disposal facility may be attached directly to the central drain.
Dish draining device 10 may be mounted directly upon a wall or other vertical surface, or it may be supported upon a movable stand 29. Stand 29 is shown in more detail in FIGS. 4 and 5. In either mounting mode, a pair of spaced apart openings are provided in back plate 21 to accept sliding entry of pin or dowel 31 which in turn is attached to a support. Dowel 31 is preferably cylindrical in shape, but may also be ovoid or polygonal in cross section. As is shown in more detail in FIGS. 6 and 7, dowel 31 is provided with an arcuate groove 32 that extends around the top and sides of the dowel at a location intermediate its ends. The length of dowel 31 is fixed such that the inner shoulder 33 of groove 32 is essentially flush with the forward surface of plate 21 thereby leaving groove 21 exposed when plate 21 is seated on the two dowels 31.
Referring now to FIG. 3 in combination with FIG. 1, main frame member 40 includes a generally rectangular perimeter element 41, suitably fabricated of heavy wire, that corresponds in size to back plate 21. A pair of downwardly opening arcuate brackets 43 attach to and extend downwardly from the top of perimeter element 41 at locations which align with the outwardly extending ends of dowels 31. Arcuate brackets 43 are sized to fit within groove 32 of dowels 31 so that brackets 43 provide direct support for frame member 40 and lock both frame member 40 and back plate 21 securely in place on dowels 31. At the same time, the unit may be easily and quickly disassembled simply by lifting frame 40 up and away from dowels 31.
Frame member 40 also includes a vertical member 44 that is placed intermediate the frame ends and is attached at its top and bottom to top and bottom of perimeter element 41. Member 44 both strengthens the frame and forms a support for a first anchor plate 46 located at the member bottom. Anchor plate 46 comprises a forwardly extending structural sheet having a pair of spaced apart openings 45 therein that are arranged to accept entry of heavy wire anchor guides 52 and 53 of plate rack holder 50 (FIG. 9.) A second anchor plate 47, similar to anchor plate 46, is attached to the side of perimeter element 41 adjacent the bottom thereof. As with anchor plate 46, plate 47 comprises a forwardly extending structural sheet also having a pair of spaced apart openings 48 that are arranged to accept entry of anchor guides 54 and 55 which are located at the opposite end of plate rack holder 50 from guides 52 and 53.
The anchor guides of plate rack holder 50 are arranged so that holder 50 may be easily attached to and removed from the anchor plates 46 and 47, while at the same time preventing inadvertent detachment of the holder from the anchor plates. Those functions are accomplished first by the length arrangement of the anchor guides. As shown best in FIG. 9, anchor guide 53 is the longest and is the first to be inserted within the corresponding opening in anchor plate 46. As soon as the end of guide 53 is inserted within the opening in plate 46, it forms a guide for placement of intermediate length guide 52 in the other plate opening. Anchor guides 54 and 55 are shortest, and cannot be fit within their respective openings in anchor plate 47 until intermediate length guide 52 is in place. Additionally, the ends 57,58 of one or both of anchor guides 54 and 55 are bent downwardly to form a hook that resists disengagement from the anchor plate 47 to thereby detachably secure plate rack holder 50 to the anchor plates of the main frame member.
Overall, plate rack holder 50 includes a generally rectangular frame having a rear frame member 61, a front frame member 62, and a pair of frame side members 63 and 64. Anchor guides 52 and 53 may conveniently be fabricated from heavy wire, and are rigidly attached to one end of rear frame member 61. Guides 54 and 55 are of similar construction and are similarly attached to the other end of member 61. The attitude of the anchor guides relative to the rack holder frame is set such that front frame member 62 is at a higher elevation than is rear frame member 61 when holder 50 is attached to the anchor plates. A plurality of equi-spaced rods 66 extend diagonally between front frame member 62 and rear frame member 61 to provide slots to hold plates while they are draining and drying.
Also attached to front frame member 62 adjacent the end thereof are at least one, and suitably two, vertically upstanding inverted U-shaped members 68 and 69. Members 68 and 69 perform a dual function. A cutlery basket 71 (FIG. 15) is provided with an outwardly extending lip 72 having a pair of slots 73 and 74 extending through the lip. Those slots are sized and spaced to accommodate passage of U-shaped members 68 and 69 to thereby hold basket 71 in place. The upper ends of members 68 and 69 then may be used to support inverted cups or glasses for draining and drying. Basket 71 is preferably of trapezoidal shape as is shown with one side 75 formed at an acute angle to lip 72 and conforming to the angle that rods 66 make with the front and rear frame members so that side 75 is generally parallel to rods 66.
Referring now to FIG. 8, there is shown a holding rack 80 for supporting cups and glassware for drainage and drying. Rack 80 includes an upper support member that may comprise a pair of closely spaced parallel rods 81 that extend from side 49 of perimeter element 41 to the vertical member 44. Rods 81 support horizontal rows of long and short variously inclined inverted U-shaped members 83 and 84 which are sized to hold inverted glassware for drainage and drying. An additional row of inclined U-shaped members 86 is supported upon another pair of closely spaced parallel rods 87 which also extend from side 49 of perimeter element 41 to the vertical member 44.
As was mentioned previously, dish draining device 10 may be mounted upon a wall or other vertical surface, or it may be mounted upon a stand 29. Stand 29 is shown in greater detail in FIG. 4. It includes two upstanding arms 91 and 92 joined at a set spaced apart distance by cross member 94. A pair of horizontal support members 95 and 96 are pivotally attached to cross member 94, one adjacent its connection to each of the upstanding arms, by way of pin means 97 and 98. In a preferred embodiment, cross member 94 is constructed of rectangular tubing pieces and is arranged to separate into two parts at a location at or near the midpoint thereof as is illustrated in FIG. 5. A bar-like, like, friction lock member 99 that is sized to fit within tubular cross member 94 serves to removably join the sections of cross member 94 together when the frame is assembled, yet allows the stand to be taken apart and compactly folded for transport or storage.
FIG. 6 illustrates a mounting pod 101 that may be used when dish draining device 10 is wall mounted. Pod 101 includes a base plate 103 that may be fixedly attached to a wall surface by means of a suitable adhesive, or may be detachably secured to a wall surface using a Velcro pad connector for that purpose. A pin or dowel 31 is centrally mounted on the base plate 103 and, as was previously described, dowel 31 is formed with an arcuate groove 32 that extends around the top and sides of the dowel at a location intermediate its ends to accept mating fit with arcuate brackets 43 of main frame 40.
For wall mounting of the dish draining device 10, a pair of pods 101 are secured to a wall surface at a spaced apart distance such that the dowels 31 fit through the openings provided in back plate 21. Additionally, each dowel 31 may be drilled along its cylindrical axis for passage of a suitable fastener such as screw 105. The screw 105 is then seated in a wall stud or other structural member to secure the dowel and dish drainer at the desired location. Because wall studs are usually placed on 16-inch centers, it is preferred that the spacing between dowel openings in the base plate 21 and the spacing between upstanding arms 91 and 92 of stand 29 also be set at 16 inches.
Pod 101 may also be used when the dish draining device 10 is mounted upon stand 29. In that mounting embodiment, stand arms 91 and 92 are provided with an array of vertically spaced holes 107 to accommodate the direct mounting thereon of dowel 31 by means of screw fastener 105. Base plate 21 is then hung upon the dowels and locked in place by the main frame bracket 43.
FIGS. 10 and 11 depict a support bracket 25 for removable water tray 24 which acts as a reservoir for water collected in catch basin 22. Bracket 25 includes a pair of vertical rod members 110 and 111 disposed parallel one to the other and joined at their bottom ends by loop 113 that forms a support for tray 24. The top end of each of rod members 110 and 111 is bent forward and downwardly to form hooks 114 and 115 that are sized to fit securely over the top of back plate 21 and the top of perimeter element 41 of main frame 40 as is illustrated in FIG. 1. A cross member 117 is fixed perpendicularly to vertical rods 110 and 111 at a location intermediate loop 113 and hook ends 114, 115. The ends of member 117 are preferably bent backwardly in opposite direction to loop 113 and hook ends 114, 115 and are each capped with a resilient spacer, 118 and 119. Those spacers, which may be made of rubber, serve to hold the lower margin of back plate 21 forward of the wall when device 10 is wall mounted. Tray 24, shown in FIG. 11, comprise a shallow, open receptacle with a flat bottom 121 that is adapted to rest upon and be supported by loop 113. A handle 122 may be provided at the front of the tray to facilitate placement and removal of the tray upon loop 113.
A removable bowl and utensil rack 125 that fits along the top of back plate 21 and frame 40 is shown in FIG. 12. Rack 125 includes an elongated rectangular frame 126 which defines a slot-like opening for supporting bowls and other utensils. Rack 125 is held in place along the top of dish draining device 10 by a plurality of mounting clips attached to frame 126. Each clip may be formed as a downwardly extending loop 128 having a leg segment 129 that parallels loop 128. Leg segment 129 is adapted to fit to the rear of back plate 21 while loop 128 is disposed to the front thereof so as to hold the rack 125 securely in place. Two clips may be joined together by means of a horizontally extending U-shaped bend 131 that serves as a support for larger bowls or utensils.
A removable bowl clip 133 is shown in FIG. 13. Clip 133 may be formed from a single piece of stiff wire having symmetrical and generally parallel leg segments 135 and 136 which terminate in hook elements 137 and 138 which are adapted to attach to frame 126 of rack 125 in the manner shown in FIG. 1. FIG. 14 illustrates another utensil holder 142 that also may be fabricated from a single piece of stiff wire. Holder 142 includes a pair of downwardly extending legs that are recurved to form bends 145 and 146 which are sized such to fit over the top of back plate 21. Bends 145 and 146 are connected by way of outwardly extending, generally horizontal loop member 147 which forms a nesting support for bowl or other utensil.
Dish draining device 10, whether mounted upon a wall or upon stand 29, takes up only a small amount of counter space and so is particularly useful in small kitchen areas such as those often found in trailers, recreational vehicles and the like. It is likewise easy to take apart for cleaning and to thereafter reassemble for use.
While the invention has been particularly shown and described with reference to the preferred embodiments thereof, it will be understood by those skilled in the art that various alterations in form and detail may be made therein without departing from the spirit and scope of the invention.
The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows: | A device including racks for supporting dishes and utensils for gravity draining and air drying is provided. The device includes a back panel having a water catchment basin at the bottom thereof which is attached to a wall or other vertical support surface by way of grooved pins that pass through openings provided in the panel. A wire frame includes arcuate brackets which fit within the pin grooves to support the frame and to lock the frame and panel onto the pins. Racks to hold glassware, plates and other utensils are attached to the frame. | 0 |
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