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BACKGROUND OF THE INVENTION
The present invention relates to a planetary speed change transmission with an input shaft, which can be drivingly connected to an output shaft by way of at least one of three planetary gear transmission structures.
In a known planetary type speed change transmission as shown for example in DE 42 38 866 C2 five forward speed ranges including a direct motion transmitting fourth speed range are obtained utilizing six friction engagement elements (three brakes and three clutches).
It is the object of the present invention to provide a planetary-type speed change transmission with at least six forward speed ranges including an upper direct transmission speed range (direct gear), wherein only a minimum of constructive changes with respect to a conventional planetary speed change transmission of this type are required.
SUMMARY OF THE INVENTION
In a planetary speed change transmission wherein an input shaft is drivingly connected, by way of at least one of three planetary gear structures, to an output shaft, five forward gears including a direct gear are obtained with three friction clutches and three friction brake structures. In one embodiment, a sixth forward gear is obtained by providing a disengageable clutch in one of the drive connections between two of the three planetary gear structures. In another embodiment, a sixth forward gear is obtained by auxiliary planetary gears which are engaged by an auxiliary ring gear which is connected to a fourth brake structure for locking the auxiliary ring gear. With this arrangement, a seventh forward gear and a second reverse gear can be obtained.
In the arrangement according to one embodiment of the invention, the object is solved by dividing the coupling connection of the input transmission structure and employing the other two transmission structures (the output transmission structure and the reversing transmission structure) as a common coupled drive for forming at least one additional forward gear. In another embodiment (as defined in claim 3 ) the object is solved by using as the input transmission structure a so-called Ravigneaux transmission with an outer additional ring gear, which is in engagement with auxiliary planet gears and which is connected to a separate brake and contributes to the formation of at least one additional forward speed range.
With the planetary speed change transmission as defined in claim 1 an intermediate forward speed range can be provided in that the separation clutch and the reverse gear brake can be disengaged while, in an intermediate gear other than a direct motion transmission (third) gear, the clutch connected to the outer ring gear of the output transmission structure as well as the brake connected to the sun gear of the output transmission structure are engaged.
In another embodiment, an additional lower forward speed range—that is, a transmission with seven forward gears—can be formed by exclusively engaging the brakes connected with the auxiliary ring gear of the input transmission structure and those connected with the sun gear of the output transmission structure whereby the transmission ratio is provided by a multiplying interconnection of the individual transmission ratios of the three transmission structures—thereby providing a first (low) speed range.
With the planetary-type speed change transmission of both embodiments, two reverse speed ranges can be obtained by operating the output transmission structure and the reverse transmission structure in both reversing speed ranges as a common coupled transmission while the reversing brake is engaged and the sun gear of the input gear structure is locked in one of the reverse gear ranges with a partial transmission ratio greater than 1 or, in the other reverse gear range, the input gear structure is at a transmission ratio of 1 by engagement of the brake connected to the sun gear.
In another embodiment of the planetary speed change transmission according to the invention an additional third reverse gear is obtained in that the output gear structure and reverse gear structure operate as a common coupled transmission structure when the reverse brake is engaged and the auxiliary ring gear, which is fixed by braking, is used as the reaction member for the input transmission structure.
In the planetary speed change transmissions of the type with which the present invention is concerned the drive connection between the sun gears of the output transmission structure and the reverse transmission structure is established by engaging a friction clutch connected to these transmission structures.
In the planetary gear speed change transmission of either of the embodiments, the drive connection between the sun gears of the output transmission structure and the reverse transmission structure may be permanent so that a clutch and the respective control equipment can be eliminated.
In the planetary gear speed change transmission according to the invention, the two lowermost speed ranges include a hill-holding function by providing a freewheeling clutch. The hill-holding function may also be effective in the third gear.
Various embodiments of the invention will be described below on the basis of the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows schematically a first embodiment of a planetary speed change transmission in cross-section,
FIG. 2 is a table showing, which of the shifting means (clutches/brakes) are effective with the various transmission ranges of the transmission,
FIG. 3 shows schematically a second embodiment of a planetary type speed change transmission in a longitudinal cross-sectional view,
FIG. 4 is a table indicating, which shifting means are activated for the various gears of the transmission as shown in FIG. 3 .
FIG. 5 shows a schematically in a longitudinal cross-sectional view a third embodiment of the planetary-type speed change transmission,
FIG. 6 is a table indicating, which shifting means are actuated for the various gears in accordance with the setup of FIG. 5,
FIG. 7 shows schematically, in a longitudinal cross-sectional view, another embodiment of the planetary type speed change transmission, and
FIG. 8 is a table indicating, which shifting means are actuated in the setup as shown in FIG. 7 .
DESCRIPTION OF PREFERRED EMBODIMENTS
All the embodiments of the planetary type speed change transmission have the following features:
An input planetary transmission structure TE includes a planetary gear carrier PTE. An outer gear ring HE is engagement with the planetary gears PE and is drivingly connected to an input shaft E. An inner sun gear SE is also in engagement with the planetary gears and is connected to a engageable and disengageable friction brake B 1 and a disengageable clutch K 1 . Between the planetary gear carrier PTE and a fixed housing part GT, there is provided a free-wheeling clutch F 1 , which engages when the planetary gear carrier PTE rotates in a direction opposite to that of the input shaft E, but permits rotation in the same direction.
An output planetary gear transmission structure TA includes a planetary gear carrier PTA on which the planetary gears PA are rotatably supported and which includes a drive connection to an output shaft A. A ring gear HA is disposed around, and in engagement with, the planetary gears PA and is connected to the input shaft E by way of an engageable and disengageable friction clutch K 2 . The planetary gears PA are further in engagement with a sun gear SA, which is connected to an engageable and disengageable brake B 2 .
A planetary gear reversing structure TU includes a planetary gear carrier PTU on which planetary gears PU are rotatably supported and which is connected to an engageable and disengageable friction brake BR and further is drivingly connected with the ring gear HA of the output planetary gear structure TA. A sun gear HU is in engagement with the planetary gears PU and has a drive connection VE to the planetary gear carrier PTE of the input transmission gear structure TE. The planetary gears PU are in engagement with a sun gear SU.
The two embodiments of FIGS. 1 and 5 have in common that a drive connection VUK is provided between the two sun gears SA and SU which can be engaged by way of an engageable and disengageable clutch K 3 .
The two embodiments of FIGS. 3 and 7 have in common, that a drive connection VWF is provided between the sun gears SA and SU, which is permanent that is the two sun gears SA and SU are drivingly interconnected.
The two embodiments of FIGS. 1 and 3 have in common that the drive connection VE between the planetary gear carrier PTE and the ring gear HU is provided by way of an engageable and disengageable friction clutch KTR and the clutch Kl, which is connected on one side to the sun gear SE is connected on the other side to the part VEU of the drive connection VE leading from the friction clutch KTR to the ring gear HU.
The two embodiments of FIGS. 5 and 7 have in common that on the planetary gear carrier PTE auxiliary planetary gears NPE are rotatably supported so as to be in engagement with the planetary gears PE and also with an auxiliary ring gear NHE which is connected to an engageable and disengageable friction brake BN.
TRANSMISSION STATE, FIRST GEAR (FIRST SPEED RANGE):
FIG. 1 : As shown in the table of FIG. 2, the brakes B 1 and B 2 as well as the clutches K 3 and KTR are engaged. In this state, the three transmission structures TE, TA and TU are set in a standard transmission ratio wherein the reaction member—sun gear SE or SA or SU respectively—, are locked in position and, with respect to the power flow through the transmission, disposed in series so that the transmission ratio is given by a multiplication of individual transmission ratios.
FIG. 3 : The state of the transmission corresponds to that of FIG. 1 as indicated in the table FIG. 4 since the clutch KTR and the brakes B 1 and B 2 are engaged and also the sun gear SU is locked by way of the connection VUF with the Brake B 2 .
FIG. 5 : Here, the state of the transmission is also such that, in accordance with the table of FIG. 6, the brake B 2 and the clutch K 3 are engaged, whereby the two transmission structures TA and TU are in a standard setting—with locked sun gears SA and SU serving as reaction members—and are arranged in series for the power flow through the transmission. This is also true for the input transmission structure TE, but, in this case, the standard transmission ratio is provided through the locked auxiliary ring gear NHE which provides for a greater transmission ratio than could be obtained by locking the sun gear SE. Consequently, a higher transmission ratio is obtained for the first speed range than with the embodiments of FIGS. 1 and 3.
FIG. 7 : According to the table of FIG. 8, the state of the transmission corresponds to that of FIG. 5, since, also in this case, the auxiliary ring gear NHE is locked by the brake BN and the sun gears SA and SU are locked by the brake B 2 . The three transmission structures TE, TA and TU are arranged in the power flow in series. Accordingly, also in this case, a higher transmission ratio is obtained for the first speed range (in first gear) than with the arrangements of FIGS. 1 and 3.
STATE OF THE TRANSMISSION 2. GEAR
FIG. 1 : As indicated in the table of FIG. 2, this state differs from that of the 1. gear only in that the input transmission structure TE is in a transmission ratio 1:1, whereas, for the other transmission structures TA and TU, the sun gears SA and SU remains locked so as to form reaction members. As a result, with the transmission ratio of 1:1 for the transmission structure TE, the overall transmission ratio is lower, that is the output speed is increased for the 2 gear with the multiplicative series arrangement of the three transmission structures.
FIG. 3 : In accordance with the table of FIG. 4, the transmission state corresponds to that of FIG. 1 in as much as the input transmission structure TE is at a transmission ratio 1:1 in series with the two other transmission ratio 1:1 in series with the two other transmission structures TA and TU which are in the standard arrangement with locked sun gears SA and SU.
FIG. 5 : In accordance with the table of FIG. 6, the transmission state corresponds to that of FIG. 1 for the first gear in as much as all three transmission structures TE, TA and TU are in their standard arrangements wherein the sun gears SE, SA and SU are all locked and act as reaction gears. Also, they are arranged in a series power flow setup so that, here too, the transmission ratio is given by multiplication of the transmission ratios of the three transmission structures.
FIG. 7 : In accordance with the table 8 , the transmission state corresponds again to that of FIG. 1 for the first gear in as much as all three transmission structures TE, TA and TU are in the standard arrangement with locked sun gears SE, SA and SU and are arranged in series so that the transmission ratio for the second gear is obtained by a multiplication of the transmission ratios of these three transmission structures TA TE and TU.
TRANSMISSION STATE, 3. GEAR
FIG. 1 : In accordance with the table of FIG. 2, the transmission state is such that the transmission structures TE and TU do not participate in the establishment of the transmission ratio since the clutch K 3 is disengaged so that the sun gear of the transmission structure TU does not act as a reaction member and the transmission structure TE is set at a transmission ratio 1:1 by the clutches K 1 and KTR. As a result, the transmission ratio for the third gear is obtained solely from the transmission ratio of the output transmission structure TA with locked sun gear SA.
FIG. 3 : In accordance with the table of FIG. 4, the transmission status for the third gear corresponds to that of FIG. 1 that is the speed transmission is again obtained solely from the transmission ratio of the output transmission structure TA with the locked sun gear SA serving as reaction member. Only the clutch K 2 and the brake B 2 are engaged and the clutch KTR is disengaged. In this third gear, the clutch K 1 may additionally be engaged in order to achieve a controlled speed behavior of the transmission members PE and SE in the input transmission structure TE. However, the clutch K 1 has no influence on the transmission ratio.
FIG. 5 : In this embodiment, the input transmission structure TE is arranged in the power flow in series with the transmission structures TU and TA by the clutch K 1 at a transmission ratio 1:1. The transmission structures TA and TU are at their standard transmission ratio with locked sun gears SA and SU respectively serving as reaction members. Consequently, the transmission ratio in this case is a product of the standard transmission ratios of the two transmission structures TA and TU.
FIG. 7 : Because the clutch K 1 and the brake B 2 are engaged as indicated in the table of FIG. 8, the input transmission structure TE is, like in the embodiment of FIG. 5, arranged in the power flow in series with the transmission structures TU and TA. The transmission structures TU and TA are at their respective standard transmission ratio by the locking the connecting structure VUF of the sun gears SU and SA which, as a result, serve as reaction members, and are arranged in series. Again the transmission ratio is formed as the product of the standard transmission ratios of the transmission structures TA and TU.
TRANSMISSION STATE, FOURTH GEAR:
FIG. 1 : Because all the clutches are engaged (K 1 , K 2 , K 3 , KTR) all three transmission structures TE, TA and TU are locked together so that the transmission ratio is 1:1.
FIG. 3 : All the clutches K 1 , K 2 and KTR are engaged that is all the transmission structure TE, TA and Tu are interconnected such that the transmission ratio is 1:1.
FIG. 5 : In accordance with the table of FIG. 6, the clutches K 1 and K 2 and the brake B 2 are engaged so that the transmission structures TE and TU are at a transmission ratio 1:1 and the output transmission structure is at its standard ratio wherein the sun gear is locked and serves as a reaction member. The transmission ratio therefore depends solely on the ratio of the output transmission structure TA.
FIG. 7 : In accordance with the table of FIG. 8, the clutch K 2 and the brake B 2 are engaged. The sun gears SA and SU are coupled together so that the transmission structures TE and TU are not included in the power transmission path. The output transmission structure TA is at its standard transmission setup wherein the sun gears SA and SU which are interconnected are locked. The transmission ratio therefore depends alone on the ratio provided by the output transmission structure TA.
TRANSMISSION STATE: FIFTH GEAR:
FIG. 1 : As shown in the table of FIG. 2, the clutches K 2 , K 3 and KTR as well as the brake B 1 are engaged so that all three transmission structures TE, TA, and TU are interconnected to form a coupled drive. The locked sun gear SE forms a reaction member so that the interconnected sun gears SA and SE are driven by the input shaft E at a speed greater than that of the output shaft A.
FIG. 3 : In this case, there is a coupling connection VUF between the sun gears SA and SU instead of an engagement of the clutch K 3 . Otherwise, the same coupling arrangement for the three transmission structures TE, TA and TU is obtained as in FIG. 1, since, in accordance with the table of FIG. 4, besides the brake B 1 also the clutches K 2 and KTR are engaged, whereby an overdrive transmission gear is obtained just like in the embodiment of FIG. 1 .
FIG. 5 : As shown in the table of FIG. 6, the three clutches K 1 , K 2 and K 3 are engaged so that all three transmission structures TE, TA and TU are interconnected and rotate as a unit so that a direct drive is obtained.
FIG. 7 : As indicated in the table of FIG. 8, the two clutches K 1 and K 3 are engaged. The function of the engaged clutch K 3 of FIG. 5 is taken over by the coupling connection VUF so that, also in this case, all three transmission structures TE, TA and TU rotate as a unit and form a direct transmission gear.
TRANSMISSION STATE 6 th GEAR
FIG. 1 : As shown in the table of FIG. 2, the brake B 1 and the clutches K 1 , K 2 and K 3 are engaged whereby the two transmission structures TA and TU are coupled. The ring gear HU is locked and serves as a reaction element. The sun gears SA and SU are driven at higher speed with respect to the input shaft E than the output shaft A.
FIG. 3 : As indicated in the table of FIG. 4, the brake Bl and the clutches K 1 and K 2 are engaged. As a result, with the the sun gears SA and SU being interconnected, the two transmission structures TA and TU are again combined to form a coupled drive with a locked ring gear HU serving as a reaction member. As a result, the sun gears SA and SU are speeded up with respect to the input shaft to a high degree and the speed of the output shaft A is increased with respect to that of the input shaft E to a smaller degree.
FIG. 5 : As indicated in the table of FIG. 6, the brake B 1 and the clutches K 2 and K 3 are engaged whereby all three transmission structures are interconnected to form a coupled drive. The sun gear SE is locked which provides for a relatively high increase of speed of the interconnected sun gears SA and SU and, to a lower degree, an increase of the speed of the output shaft A with respect to the input shaft E.
FIG. 7 : As indicated in the table of FIG. 8, the brake BI and the clutch K 2 are engaged. The coupling connection VUF interconnects the sun gears SA and SU so that all three transmission structures TE, TA and TU are interconnected and form a coupled drive. The sun gear SE is locked and forms a reaction member. In this setup, the speed of the sun gears SA and SU is increased to a relatively large degree and to a smaller degree the speed of the output shaft A relative to the input E shaft.
TRANSMISSION STATE: 7 th GEAR:
FIG. 5 : As indicated in the table of FIG. 6, the brake BN and the clutches K 2 and K 3 are engaged so that all three transmission structures are combined to a singled coupled drive, wherein the locked auxiliary gear ring NHE increases the speed of the drive, that is, the speed of the sun gears SA and SU at a relatively high rate and to a lesser degree the speed of the output shaft A with respect to the speed of the input shaft E.
FIG. 7 : As indicated in the table of FIG. 8, the brake BN and the clutch K 2 are engaged. In this case, the coupling VUF of the sun gears SA and SU assumes the function of an engagement of the clutch K 3 in FIG. 5, so that also here all three transmission structures TE, TA and TU are interconnected to form a common coupled drive unit, wherein the locked auxiliary ring gear NHE forms a reaction member providing for an increased speed of the sun gears SA and SU at a relatively high rate and at a lesser rate for the output shaft A with respect to the input shaft E.
TRANSMISSION STATE REVERSE GEAR R 1 :
FIG. 1 : As indicated in the table of FIG. 2, the brakes B 1 and BR and the clutches K 3 and KTR are engaged. As a result, the two transmission structures TA and TU are interconnected so as to form a coupled drive with a locked planetary gear carrier PTU. In the power path ahead of the coupled drive, the transmission structure TE is disposed in standard arrangement with locked sun gear. With the standard transmission arrangement a relatively high transmission is obtained in this speed range which provides for an opposite direction of rotation for the interconnected sun gears SA and SU because of the engagement of the reverse brake BR. As a result, the speed of the sun gears SA and SU for the output shaft A is again somewhat reduced.
FIG. 3 : In this case, the coupler shaft VUF assumes again the function of the engagement state of the clutch K 3 of FIG. 1, whereas, in accordance with the table of FIG. 4, the clutch KTR and the reverse brake BR are also here engaged. As a result, the transmission structures TA and TU are interconnected so as to form a drive unit and the input transmission structure TE in its standard arrangement is disposed in the power flow path ahead of the drive unit. In this way, the standard transmission arrangement again provides for a high transmission ratio and the engaged reverse brake BR provides for reverse rotation of the sun gears SA and SU, whose speed is again reduced in the output transmission structure TA providing for a reduced reverse speed of the output shaft.
FIG. 5 : As indicated in the table of FIG. 6, the brakes B 1 and BR as well as the clutch K 3 are engaged so that the two transmission structures TA and TU are again interconnected to form a drive unit with a locked planetary gear carrier PTU. The input transmission structure in standard arrangement is disposed in the power path ahead of the drive unit. The standard arrangement of the transmission structure TE provides for a high transmission ratio whereas the effective reaction member PTU in the drive unit provides for reverse rotation of the coupled sun gears SA and SU, whose speed is again somewhat reduced in the output transmission structure for the output shaft A.
FIG. 7 : As indicated in the table of FIG. 8, only the brakes B 1 and BR are engaged. The function of the engaged state of the clutch 3 of FIG. 5 is again provided by the coupler shaft VUF so that the two transmission structures TA and TU are interconnected to a drive unit with a locked planetary gear carrier PTU serving as a reaction member. The input transmission structure in standard arrangement with locked sun gear SE is arranged in the power path ahead of the drive unit. The standard arrangement provides for a high transmission ratio. The engaged reverse brake BR provides for reverse rotation of the interconnected sun gears SA and SU whose speed is again reduced in the output gear structure TA for the output shaft A.
TRANSMISSION STATE REVERSE GEAR R 2
FIG. 1 : As indicated in the table of FIG. 2, the clutches K 1 , K 3 and KTR as well as the reverse brake BR are engaged. As a result, the input transmission structure TE operates as a unit with the transmission ratio 1:1 with which the coupled drive formed by the other two transmission structures TA and TU is arranged in series. The planetary carrier PTU is locked and forms a reaction member arranged in the power path in series. The transmission ratio 1:1 provides for a lower speed and the engaged brake BR provides for the reverse rotation of the interconnected sun gears SA and SU whose speed is somewhat reduced in the output transmission structure TA for the output shaft A.
FIG. 3 : As indicated by the table of FIG. 4, the clutches K 1 and KTR as well as the brake BR are engaged whereas the coupling shaft VUF fulfills the function of the engaged clutch K 3 of FIG. 1 . As a result, the input transmission structure TE rotates as a unit with a transmission ratio 1:1. The coupled drive unit formed by the two other transmission structures TA and TU with the locked planetary gear carrier PTU forming a reaction member is arranged in the power path in series with the transmission structure TE. The partial transmission ratio of 1:1 provides for a low total transmission ratio. The engaged reverse brake BR changes the direction of rotation of the interconnected sun gears SA and SU whose speed is reduced in the output transmission structure TA for the output shaft A.
FIG. 5 : As indicated in the table of FIG. 6, the clutches Kl and K 3 as well as the reverse brake BR are engaged. The input transmission structure TE rotates as a unit with a transmission ratio 1:1. The two other transmission structures TA and TU form a coupled drive with locked planetary carrier PTU as reaction member and are arranged in the power path in series. The partial transmission ratio 1:1 provides for a small speed change. The engaged brake BR provides for reverse rotation of the sun gears SA and SU. The speed is reduced in the output transmission structure TA for the output shaft A.
FIG. 7 : As indicated in the table of FIG. 8, the clutch K 1 and the reverse brake BR are engaged. The function of the engaged clutch K 3 of FIG. 5 is also here fulfilled by the interconnection VUF of the sun gears SA and SU. The input transmission structure TE operates as a unit with a partial transmission ratio of 1:1. The coupled drive with locked planetary gear carrier PTU forming a reaction member provided by the two other transmission structures TA and TU is arranged in the power path in series with the input transmission structure TE. The partial transmission ratio 1:1 does not provide for a speed change. The engaged brake BR reverses the direction of rotation of the interconnected sun gears SA and Su. The speed is reduced in the output transmission structure for the output shaft A.
TRANSMISSION STATE REVERSE GEAR R 3 :
FIG. 5 : As indicated in the table of FIG. 6, the brakes BN and Br as well as the clutch K 3 are engaged. As a result, the two transmission structures TA and TU are joined to form a drive unit with locked planetary gear carrier PTU and gear ring forming a reaction member. The input transmission structure TE is in a standard arrangement with locked gear ring NHE which forms a reaction member. This arrangement provides for the largest speed change of the three reverse stages R 1 to R 3 , whereas the engaged brake BR provides for the reverse rotation of the interconnected sun gears SA and SU. The speed is further reduced in the output transmission structure TA for the output shaft A.
FIG. 7 : As indicated in the table of FIG. 8 only the brakes BN and BR are engaged. The function of the engaged clutch K 3 of FIG. 5 is performed by the coupler shaft VUF interconnecting the sun gears SA and SU. Consequently, the two transmission structures TA and TU form a drive unit with locked planetary carrier PTU. The input transmission structure TE in standard arrangement with the locked auxiliary gear ring NHE forming a reaction member is arranged in the power transmission path ahead of the drive unit. The locked auxiliary gear ring NHE causes a very high speed change—the highest of the three reverse gears—whereas the locked planetary gear carrier PTU provides for the reverse rotation of the interconnected sun gears SA and SU. The speed is further reduced in the output transmission TA for the output shaft A.
Throughout the description, reference was made to gears to indicate the rotary motion transmission members of the various transmission structures. It is pointed out however that the gears could be replaced for example by friction or traction rollers.
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In a planetary speed change transmission wherein an input shaft is drivingly connected, by way of at least one of three planetary gear structures, to an output shaft five forward gears including a direct gear are obtained with three friction clutched and three friction brake structures. In one embodiment, a sixth forward gear is obtained by providing in one of the drive connections between two of the three planetary gear structures a disengageable clutch. In another embodiment, a sixth forward gear is obtained by auxiliary planetary gears which are engaged by an auxiliary ring gear that is connected to a fourth brake structure for locking the auxiliary ring gear. With this arrangement, a seventh forward gear and a second reverse gear can be obtained.
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This application claims priority from U.S. Provisional application No. 60/034,838 filed on Dec. 31, 1996.
BACKGROUND OF THE INVENTION
Recently a process has been disclosed in U.S. Pat. No 5,607,551 issued Mar.4, 1997 to Farrington, Jr. et al. which allows the production of soft absorbent tissue structures without the use of traditional Yankee dryer creping. Sheets produced by this uncreped throughdried process can be characterized as being very three dimensional with high bulk, high absorbent capacity and fast absorbent rate. However, because of the high degree of surface contour, such sheets can also abrade the skin. In addition, while the high absorbent capacity and fast absorbent rate of sheets produced in this manner can be ideal for some absorbent products, soft tissues such as facial and bathroom tissue often find advantages in a more controlled, even slow, absorbent rate while maintaining high absorbent capacity.
While it is known to provide tissues with lotions that can improve softness, the addition of such materials can decrease the thickness of the tissue sheets due to a partial collapse of the crepe structure when exposed to moisture and processing pressures.
Furthermore, the general approach in the industry has been that the greater the quantity of additive on the tissue, the greater the benefit. Contributing to this approach is the fact that particular additives may be absorbed into the tissue, leaving less additive on the surface to provide the intended benefit. One major drawback to the “more is better”philosophy is cost. Additives to address skin abrasion can represent a significant portion of the cost of a tissue sheet. Also, for some additives, relatively high addition levels can be difficult to manufacture.
Thus, there is first a need to enhance sheet softness and/or reduce the potential for skin abrasion with an economical, yet effective, surface additive without losing the thickness of the uncreped throughdried tissue. Secondly there is a need for a cost effective method to manufacture uncreped throughdried tissue products including such an additive.
SUMMARY OF THE INVENTION
It has now been discovered that, surprisingly, uncreped throughdried tissue products containing an additive adapted to reduce skin irritation and redness can be manufactured with substantially lower total add-on amounts without decreasing the effectiveness of the additive. Applicants have discovered that an array of primary delivery zones with a relatively high additive add-on amount in combination with supplementary delivery zones with a relatively lower add-on amount can be used effectively to maximize consumer benefit while minimizing the total amount of additive on the tissue.
In one embodiment, a tissue product is formed with one or more uncreped throughdried tissue plies and defines a major surface having a planar surface area. The tissue product comprises an additive composition disposed on the major surface in at least one primary delivery zone and at least one supplementary delivery zone. The primary delivery zone has a primary add-on level and the supplementary delivery zone has a supplementary add-on level. The supplementary add-on level is greater than zero and from about 0.5 to about 80 percent of the primary add-on level.
In another embodiment, a tissue product is formed with one or more uncreped throughdried tissue plies. The tissue product comprises an additive composition disposed on a major surface in at least one primary delivery zone having a primary add-on level and at least one supplementary delivery zone having a supplementary add-on level. The supplementary add-on level is greater than zero and the primary add-on level is greater than the supplementary add-on level. The primary delivery zone covers from about 30 to about 90 percent of the tissue surface area and the supplementary delivery zone covers from about 10 to about 70 percent of the tissue surface area.
The primary and supplementary add-on amounts, and the number, size, shape, and position of the primary and supplementary delivery zones, can be selected to maximize the overall benefit provided to the consumer while minimizing the total add-on amount.
The terms “primary add-on amount” and “primary add-on level” refer to the basis weight of additive composition in the primary delivery zone or zones, typically measured in grams per square meter (gsm). In contrast, the terms “supplementary add-on amount” and “supplementary add-on level” refer interchangeably to the basis weight of additive composition in the supplementary delivery zone or zones. Thus, for any given tissue including a surface additive composition segmented into zones having different add-on amounts, the zone or zones having higher add-on amounts are deemed the primary delivery zones and the zone or zones having lower add-on amounts are deemed the supplementary delivery zones. The primary and supplementary delivery zones may be used on one or both surfaces of the tissue.
For purposes of the present invention, the primary add-on amount is generally set as the level of the selected additive that provides a high degree of satisfaction on the part of the consumer. The supplementary add-on amount provides a lesser degree of consumer satisfaction than the primary add-on amount, but significantly, it still provides some degree of benefit. The actual basis weight values for the primary and supplementary add-on amounts may need to be determined by comparing the consumer benefits obtained from a series of test tissue products that differ from one another only in the additive add-on amount, each having a uniform application of the additive deposited on one surface or both surfaces. The primary add-on amount will be the same as or similar to the add-on amount on the test tissue products that deliver the desired level of consumer benefit. The supplementary add-on amount will then be greater than zero but less than the primary add-on amount.
The number, size, shape and position of the primary delivery zone or zones on a particular tissue are selected so as to obtain the same or substantially the same consumer benefit as would be obtainable from a tissue having a uniform add-on amount equal to the primary add-on amount. One or more supplementary delivery zones are provided on the tissue product so as not to detract from the benefit delivered by the primary delivery zones. The supplementary delivery zones allow for a reduction in the cost of the tissue product compared to what would result if the total coverage area included the additive composition at the primary add-on amount. It is theorized that “additive void areas,” that is, areas on the surface of the tissue that do not contain the additive composition, significantly detract from the benefit provided by the primary delivery zone or zones. The combination of primary and supplementary delivery zones is thought to allow delivery of the consumer benefit afforded by the primary add-on amount but at a lower cost.
By way of illustration, a single primary delivery zone may be centrally located on the tissue surface and comprise about 65 percent of the planar surface area of the tissue. A single supplementary delivery zone may completely surround the primary delivery zone and comprise about 35 percent of the planar surface area. In this embodiment, the primary delivery zone is centrally located to maximize the opportunity for the higher, primary add-on amount of additive to contact the skin during product use to yield maximum benefit. The supplementary delivery zone provides some benefit, and importantly does not detract from the benefit derived from the primary delivery zone. Such a tissue is believed to be capable of providing consumer benefits comparable to a tissue having a uniform additive add-on amount equal to the primary add-on amount centrally located over 100 percent of the planar surface area, and at a reduced cost.
By way of further illustration, the tissue product may comprise an alternating pattern of primary and supplementary delivery zones. This product as well is capable of providing the consumer benefits associated exclusively with the higher add-on amount, but at a reduced cost because the primary delivery zones tend to mask the reduction in additive of the supplementary delivery zones. Again, the placement of the supplementary delivery zones adjacent the primary delivery zones does not reduce the benefits delivered by the primary delivery zones, as would otherwise be the case if additive void areas took the place of the supplementary delivery zones.
It should be readily appreciated that a wide variety of configurations of the number, size, shape, and position of the primary and supplementary delivery zones may be possible. The specific size of the primary delivery zones and the supplementary delivery zones will depend upon the desired effect of the composition and the specific composition.
For example, in the course of blowing or wiping the nose, pressure is exerted against the tissue and nose by the fingers. Therefore the size of the zones can be regulated by the dimension of a single finger or several fingers used jointly to apply pressure while wiping the nose. Ideally the additive regions giving the most important benefit, that is the primary delivery zones, would each have an individual zone size at least as large as those dimensions so that at any one point of contact during wiping the most important additive is always in contact with the skin. Furthermore, each individual supplementary delivery zone would preferably have an individual zone size smaller than that of the primary delivery zones and thus smaller than the dimension of a single finger or several fingers. When using primary and supplementary delivery zones, limited use of additive void areas may be acceptable. Desirably, of course, the dimension of additive void areas, if incorporated into the design, would be even further reduced.
Using this as an example, a single primary delivery zone may desirably have a width dimension of from about 0.2 inch to about 5.5 inches, such as about 0.2 to about 4 inches, more specifically from about 0.4 inch to about 2 inches, and still more specifically from about 0.5 inch to about 1.5 inches. A single supplementary delivery zone may desirably have a width dimension of from about 0.1 inch to about 2 inches, more specifically from about 0.2 inch to about 1 inch, and still more specifically from about 0.25 to about 0.75 inch. If present at all, each additive void area will desirably have a width dimension of from about 0.003 inch to about 1 inch, more specifically from about 0.008 inch to about 0.5 inch, and still more specifically from about 0.02 inch to about 0.2 inch. It should be appreciated that there might be conditions such as cost, wiping task, and the like that would change these primary, supplementary, and void area zone size relationships. The length dimensions of the primary and supplementary delivery zones and the additive void areas may extend over the entire tissue or only over part of the tissue.
It is generally thought to be desirable for the primary and supplementary delivery zones to be positioned immediately adjacent one another. As used herein, the term “immediately adjacent” refers to the primary and supplementary delivery zones having at least one common boundary, rather than being separated by an additive void zone. It is hypothesized that the effectiveness of the additive composition in the primary delivery zones is maintained to a greater extent when the primary delivery zones are disposed adjacent supplementary delivery zones as opposed to adjacent additive void zones.
The specific area coverage of the primary delivery zones, the supplementary delivery zones, and the void areas will depend upon the desired effect of the composition and the specific composition. The tissue coverage of the primary zones will generally be from about 30 to about 90 percent, more specifically from about 40 to about 80 percent, and more specifically from about 50 to about 75 percent, based on the simple planar view surface area of the tissue. The tissue coverage of the supplementary zones will generally be from about 10 to about 70 percent, more specifically from about 20 to about 60 percent, and more specifically from about 25 to about 50 . The void areas that may be present will generally represent from about 0.5 to about 50 percent, more specifically from about 1 to about 25 percent, and still more specifically from about 1 to about 12 percent. Correspondingly, the primary and supplementary delivery zones desirably have a combined surface area of at least about 50 percent, more particularly at least about 75 percent, and even more particularly at least about 88 percent, such as 100 percent, of the planar surface area. The total tissue area coverage of the primary delivery zones, supplementary delivery zones, and the void areas represent, by definition, 100 percent of the tissue surface area, based on the simple planar view surface area.
Another aspect of the invention relates to a method of making an uncreped throughdried tissue product. The method comprises the steps of providing a tissue web having one or more uncreped throughdried tissue plies; providing an additive composition; applying the additive composition to the tissue web using a rotogravure process comprising an engraved roll having primary and supplementary regions, the primary and supplementary regions adapted to provide different add-on rates; and recovering from the rotogravure process a tissue product having the additive composition disposed in both a primary delivery zone having a primary add-on level and a supplementary delivery zone having a supplementary add-on level, with the supplementary add-on level being greater than zero and from about 0.5 to about 80 percent of the primary add-on level.
One particularly beneficial method is to uniformly apply the composition to the surface of the uncreped throughdried tissue web within each of the zones by rotogravure printing, either direct or indirect (offset), because it is a very exact printing process and offers maximum control of the composition distribution and transfer rate. However, other application methods, such as flexographic printing, spraying, extruding, and the like can also be used.
Typical of gravure printing, the additive composition in each of the primary and supplementary delivery zones may actually be present in a large number of small, spaced apart deposits on the tissue surface. These deposits are desirably uniformly positioned within each zone but only cover part of the surface in each zone. When viewed by the naked eye, the large number of small spaced-apart deposits appear to cover the entire surface, but in fact do not. The actual surface area coverage of the deposits can be from about 30 to about 99 percent, more specifically from about 50 to about 80 percent. For purposes of the present invention, the surface areas of the primary and supplementary delivery zones include the complete area circumscribed by the pattern of deposits, and not just the actual surface area coverage of the deposits.
Gravure printing is ideally suited to such an application by providing, for example, from about 10 to about 1000 deposits per lineal inch of surface, or from about 100 to about 1,000,000 deposits per square inch. Each deposit results from an individual cell on a printing roll, so that the density of the deposits corresponds to the density of the cells. Gravure printing encompasses several well known engraving techniques, such as mechanical engraving, acid-etch engraving, electronic engraving and ceramic laser engraving. A suitable electronic engraved example for a primary delivery zone is about 200 deposits per lineal inch of surface, or about 40,000 deposits per square inch. By providing such a large number of small deposits, the uniformity of the deposit distribution is very high. Also, because of the large number of small deposits applied to the surface of the tissue, the deposits more readily resolidify on the surface of the tissue where they are most effective in benefiting the user. As a consequence, a relatively low amount of the composition can be used to cover a large area.
The add-on rate is also determined by the volume of the gravure roll engraving. Typically, this is expressed in terms of the volume of the cells per square inch of engraved area. The volume in the primary delivery regions will deliver more additive composition than the volume in the supplementary delivery regions. The range of liquid cell volume for a primary delivery region, described in terms of cubic billion microns (CBM) per square inch, is suitably from about 0.5 to about 15 CBM per square inch, more specifically from about 1 to about 10 CBM per square inch, and still more specifically from about 1.5 to about 8 CBM per square inch. The range of liquid cell volume for a supplementary delivery region is suitably from 0.1 to about 10 CBM per square inch, more specifically from about 0.5 to about 8 CBM per square inch, and still more specifically from about 0.75 to about 6 CBM per square inch.
The additive composition or compositions can be applied to one or both outer surfaces of an uncreped tissue without substantially decreasing the perceived thickness of the product relative to an untreated tissue product. The additive composition can be waterbased or oil-based. Suitable water-based compositions include, but are not limited to, emulsions and water-dispersible compositions which can contain, for example, debonders (cationic, anionic or nonionic surfactants), or polyhdroxy compounds such as glycerin or propylene glycol. More typically for an uncreped throughdried basesheet, the basesheet would be treated with a bi-component system comprising a debonder and a polyhydroxy compound. Both components can be added separately or mixed together prior to being applied to the basesheet. In particular embodiments, the primary and supplementary delivery zones or the opposite sides of the tissue could comprise different additive compositions.
In particular embodiments, the tissue products are made by applying, on the surface(s) of the tissue, large numbers of individual deposits of a melted moisturizing/protective additive composition comprising a wax and an oil, and thereafter resolidifying the composition to form a distribution, of solid deposits on the surface(s) of the tissue. Because the composition is a solid at room temperature and rapidly solidifies after deposition, it has less tendency to penetrate and migrate into the sheet. Compared to tissues treated with liquid formulations, this leaves a greater percentage of the added composition on the surface of the tissue where it can contact and/or transfer to the user's skin to provide a benefit. Furthermore, a lower add-on amount can be used in both the primary and supplementary zones to deliver the same benefit at lower cost because of the efficient placement of the composition substantially at the surface of the product.
The additive composition may comprise solidified deposits of a composition comprising from about 30 to about 90 weight percent oil, and from about 10 to about 40 weight percent wax, preferably also containing from about 5 to about 40 weight percent fatty alcohol, said composition having a melting point of from about 30°C. to about 70°C., more specifically from about 40°C. to about 60°C. For purposes herein, “melting point” is the temperature at which the majority of the melting occurs, it being recognized that melting actually occurs over a range of temperatures.
The amount of oil in the composition can be from about 30 to about 90 weight percent, more specifically from about 40 to about 70 weight percent, and still more specifically from about 45 to about 60 weight percent. Suitable oils include, but are not limited to, the following classes of oils: petroleum or mineral oils, such as mineral oil and petrolatum; animal oils, such as mink oil and lanolin oil; plant oils, such as aloe extract, sunflower oil and avocado oil; and silicone oils, such as dimethicone and alkyl methyl silicones.
The amount of wax in the composition can be from about 10 to about 40 weight percent, more specifically from about 10 to about 30 weight percent, and still more specifically from about 15 to about 25 weight percent. Suitable waxes include, but are not limited to the following classes: natural waxes, such as beeswax and carnauba wax; petroleum waxes, such as paraffin and ceresine wax; silicone waxes, such as alkyl methyl siloxanes; or synthetic waxes, such as synthetic beeswax and synthetic sperm wax.
The amount of fatty alcohol in the composition, if present, can be from about 5 to about 40 weight percent, and more specifically from about 10 to about 30 weight percent. Suitable fatty alcohols include alcohols having a carbon chain length of C 14 -C 30 , including acetyl alcohol, stearyl alcohol, behenyl alcohol, and dodecyl alcohol.
In order to better enhance the benefits to consumers, additional ingredients can be used. The classes of ingredients and their corresponding benefits include, without limitation, C 10 or greater fatty alcohols (lubricity, body, opacity); fatty esters (lubricity, feel modification); vitamins (topical medicinal benefits); dimethicone (skin protection); powders (lubricity, oil absorption, skin protection); preservatives and antioxidants (product integrity); ethoxylated fatty alcohols; (wetability, process aids); fragrance (consumer appeal); lanolin derivatives (skin moisturization), colorants, optical brighteners, sunscreens, alpha hydroxy acids, natural herbal extracts, and the like.
The above additive composition may be applied to one or both outer surfaces of the tissue by heating the composition to a temperature above the melting point of the composition, for instance a melting point of from about 30°C. to about 70°C, thereby causing the composition to melt. The additive is then uniformly applied within each of the primary and supplementary zones at the predetermined add-on amounts for such zones by uniformly applying the melted composition to one or both surfaces of a tissue web in spaced-apart deposits. Thereafter, the deposits of the melted composition are resolidified. Resolidification of the deposits can occur almost instantaneously, without the need for external cooling means such as chill rolls, if the composition is heated to a temperature only slightly above or at the melting point of the composition. However, external cooling means such as chill rolls, either before or after the application of the melt, can be used if desired to accelerate resolidification. Such instantaneous resolidification tends to impede penetration of the composition into the tissue and retain it on the surface of the tissue, which is advantageous. For example, the temperature of the melted composition can advantageously be above the melting point about 10°C. or less, more specifically about 5 °C. or less, and still more specifically about 2°C. or less. As the temperature of the melted composition approaches the melting point, the viscosity of the melted composition generally increases, which further enhances the tendency of the melted composition to be retained on the surface.
Surface additive compositions of the foregoing type comprising a wax and an oil are disclosed in International Patent application PCT/US96/01243 published Aug.15, 1996and identified as WO96/24722; and International Patent application PCT/US96/01297published Aug.15, 1996 and identified as WO96/24723; the disclosures of which are incorporated herein by reference.
The total tissue add-on amount of the additive composition represents the combined primary and supplementary add-on amounts and can be from about 1 to about 40 weight percent, more specifically from about 3 to about 15 weight percent, and still more specifically from about 5 to about 10 weight percent, based on the weight of the tissue. The add-on amount for each of the primary and supplementary delivery zones will depend upon the desired effect of the composition on the product attributes and the specific composition. Generally, though, with respect to an additive composition of the foregoing type comprising a wax and an oil, the primary add-on amount is suitably from about 1 to about 35 weight percent, more specifically from about 3 to about 15 weight percent, and still more specifically from about 4 to about 10 weight percent, based on the weight of the tissue. Moreover, the supplementary add-on amount is suitably from about 0.2 to about 28 weight percent, more specifically from about 0.5 to about 12 weight percent, and still more specifically from about 1 to about 8 weight percent, based on the weight of the tissue. Relative to one another, the supplementary add-on amount for an additive composition comprising a wax and an oil is preferably from about 0.5 to about 80 percent, more specifically from about 5 to about 70, and still more specifically from about 15 to about 50 percent, of the primary add-on amount.
The presence of the additive composition comprising a wax and an oil and the differences in add-on amounts in the various zones of the tissue, can be verified by image analysis of the surface or surfaces of the tissue after treatment with osmium tetroxide to stain the add-on composition. The uniformity of the osmium-stained tissues within each of the primary and supplementary delivery zones can be characterized by a percent coefficient of variation of about 15 or less, more specifically about 10 or less, and still more specifically from about 5 to about 15. The degree of penetration (or lack of penetration) of the osmium-stained composition can be characterized by a mean gray level difference between opposite sides of a single ply of the tissue, GL diff (hereinafter defined), of about 5 or greater, more specifically about 10 or greater, and still more specifically from about 5 to about 15.
The osmium tetroxide staining treatment used to measure the uniformity and the penetration of the composition is carried out by placing the tissues loosely in a glass bell jar having an opening diameter of about 12-16 inches and a depth of about 12 inches.
Care is taken not to stack the tissues, which would hinder adequate penetration of the vapors to all tissues. Osmium tetroxide is received as a crystalline solid in a sealed glass ampule which is broken open and placed in the bell jar with the tissues. The top is placed on the bell jar forming an air-tight seal. The tissues remain in the bell jar for about 24 to 48 hours. The osmium tetroxide has a high vapor pressure and sublimes readily to a gas which permeates the bell jar chamber. After staining is complete, the bell jar is opened and the samples are allowed to ventilate 12 to 24 hours before handling in order to release any residual unreacted vapors. Note: the greatest care must be exercised when using osmium tetroxide. It is a powerful oxidizer and highly toxic. All procedures with this material should be conducted in a fume hood with adequate air flow.
In order to measure the percent coefficient of variation, the osmium-treated sheet is viewed with an omnidirectional darkfield lighting produced by an 8-bulb octagonal ring illuminator surrounding a 50 millimeter EL-Nikkor lens attached to a 10 millimeter C-mount extension tube. This is input into a Quantimet 970 Image Analysis System (Leica, Deerfield, IL) by a chalnicon scanner. The field size (standard live frame) is 2.77 centimeters ×2.17 centimeters, or adjusted to be smaller to accommodate narrower shaped primary or secondary zones. Various fields of the osmium-treated tissue sample are placed under the lens and measured using a black photodrape background. Six (6) fields in total are measured. The scanner white level is always set at 1.00 volt. At the 5 end, the histogram is printed out and its standard deviation divided by its mean gray level is the coefficient of variation. When multiplied by 100, this becomes the percent coefficient of variation.
In order to determine the mean gray level difference, the imaging and optical conditions used are the same as described above for the uniformity measurement. But in this case, top surface and bottom surface pieces of each ply of tissue are placed tightly next to each other to from a “butt joint” with no gap between the two pieces. The sample is placed under the lens with, for example, the lighter bottom surface piece on the right of the image frame and the darker top surface piece on the left of the image frame.
If first measuring the gray-level histogram of the lighter, bottom surface, the variable live frame is placed over just that region of the image frame, with the scanner white level set at 1.00 volt for the whole field. Then the sample is rotated so that the lighter bottom surface is now on the left. The scanner is adjusted against to 1.00 volt and this surface is once again isolated by the variable live frame. This data is accumulated into the same gray-level histogram. The mean gray level of the bottom surface, GL BOTTOM , is recorded.
The same procedure is then conducted on the darker, top surface that occupies the other half of the image, again with the scanner white level set at 1.00 volt for the entire image. This will tend to compensate for the overall difference in the amount of the composition added to the tissue, while zeroing in more accurately on whether the composition is on the top or bottom surface, which reflects the degree of penetration. Again, the mean gray level of the top surface, GL top, is recorded.
Finally, the difference between the two mean gray levels, GL DIFF, is calculated as a value inversely related to the penetration:
GL DIFF =GL BOTTOM −GL TOP
Note that if GL DIFF is zero or negative, then complete penetration has occurred. If
GL DIFF is strongly positive, then most of the osmium-stained composition is sitting on the top surface of the tissue.
The additive composition may alternatively comprise a silicone compound.
Suitable silicone compounds are those silicone compounds which provide a smooth, lubricated surface feel, preferably without smearing glass. Preferably the silicone compounds are present in an aqueous emulsion and/or solution for ease in handling and processing. A wide variety of such silicone compounds are known in the art. Specific suitable silicone compositions indude, without limitation, polydimethyl siloxanes; mixtures of polydimethyl siloxanes and alkylene oxide-modified polydimethyl siloxanes; organomodified polysiloxanes; mixtures of cyclic- and non-cyclic-modified dimethyl siloxane; and the like. Number average molecular weights are generally about 10,000 or greater. Also suitable are aqueous mixtures of tetraethoxy silane, dimethyl diethoxy silane, and ethylene oxide/dimethyl siloxane copolymer. A preferred composition contains about 5 weight percent tetraethoxy silane, about 5 weight percent dimethyl diethoxy silane, and about 2 weight percent ethylene oxide/dimethyl siloxane copolymer in water. In such silane mixtures, the ethylene oxide-dimethyl siloxane acts as a coupling agent to bind the silicone to the tissue sheet surface, thus retarding residue build-up on the contact surface and thereby reducing the greasy feeling associated with some lubricants.
Surface additive compositions of the foregoing type comprising a silicone compound are disclosed in U.S. Pat. No.4,950,545 issued Aug.21, 1990 and U.S. Pat. No.5,227,242 issued Jul.13, 1993, both to Walter et al.; the disclosures of which are incorporated herein by reference.
The total amount of silicone solids in the tissue sheet can be from about 0.1 to about 5 weight percent, based on the finished basis weight of the tissue sheet. Preferably the amount of the silicone compound is from about 0.5 to about 3 weight percent and most preferably from about 0.7 to about 2 weight percent. Amounts below 0.1 weight percent alone provide little benefit to the facial tissue in terms of softness improvement. Amounts above 5 weight percent may become economically unattractive.
The primary add-on amount of an additive composition comprising a silicone compound is suitably from about 0.1 to about 5 weight percent, more specifically from about 0.5 to about 3 weight percent, and still more specifically from about 0.7 to about 2 weight percent, based on the weight of the tissue. Moreover, the supplementary add-on amount of an additive composition comprising a silicone compound is suitably from about 0.05 to about 3.5 weight percent, more specifically from about 0.25 to about 1.75 weight percent, and still more specifically from about 0.35 to about 1 weight percent, based on the weight of the tissue. Relative to one another, the supplementary add-on amount for a silicone compound additive composition is preferably from about 0.5 to about 80 percent, more specifically from about 5 to about 70, and still more specifically from about 15 to about 50 percent, of the primary add-on amount.
The presence of the silicone compound additive composition and the differences in add-on amounts in the various zones of the tissue can be verified by infrared spectroscopy and X-ray fluorescence.
The silicone compound can be incorporated into the facial tissue by any suitable means, including printing, spraying, dipping and the like. The silicone compound can be incorporated into the tissue sheet at any point in the tissue manufacturing process. Preferably the silicone compound is printed onto a dried tissue sheet between the base sheet manufacturing process and the final tissue product converting process. Printing provides precise control of the add-on amount of the silicone compound and places the silicone compound on the surface of the tissue in the selected primary and supplementary zones to maximize its effectiveness.
The tissue product of this invention can be one-ply, two-ply, three-ply or more. In all cases, the additive composition is desirably applied to the outer surface(s) of the product.
The composition can be applied after the plies are brought together or prior to bringing the plies together. The individual plies can be layered or non-layered (homogeneous) and uncreped and throughdried.
For purposes herein, “tissue sheet” is a single ply sheet suitable for facial tissue, bath tissue, towels, napkins, or the like having a density of from about 0.04 grams per cubic centimeter to about 0.3 grams per cubic centimeter and a basis weight of from about 4 to about 40 pounds per 2880 square feet. Tensile strengths in the machine direction are in the range of from about 100 to about 5,000 grams per inch of width. Tensile strengths in the cross-machine direction are in the range of from about 50 to about 2500 grams per inch of width. Cellulosic tissue sheets of paper-making fibers are preferred, although synthetic fibers can be present in significant amounts.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic process flow diagram for a method of making an uncreped tissue base sheet as would be done in preparation for off-line printing of the heated composition.
FIG. 2 is a schematic process flow diagram for a method of this invention in which parent rolls of uncreped throughdried tissue are treated on one side using an off-line heated direct gravure process.
FIG. 3 is a schematic depiction of the heated direct rotogravure process in which the melted composition is applied to both sides of the tissue.
FIG. 4 is a further schematic depiction of a method of this invention in which both sides of the tissue product are printed with the melted composition using a combination of heated offset gravure printing and heated direct gravure printing.
FIG. 5 is a further schematic depiction of a method of this invention in which both sides of a tissue are simultaneously printed with the melted composition using heated offset gravure printing.
FIG. 6 is a further schematic depiction of a method of this invention in which both sides of the tissue sheet are consecutively printed with the melted composition using heated offset gravure printing.
FIG. 7 is a schematic diagram showing a process for making an uncreped throughdried tissue sheet and applying the heated composition during the manufacturing process using a heated rotogravure printer in accordance with this invention.
FIG. 8 representatively shows a top plan view of one exemplary engraved roll for use in manufacturing tissue products.
FIG. 9 representatively shows a tissue product manufactured using the engraved roll of FIG. 8 and treated with osmiun tetroxide to stain the additive composition black.
FIG. 10 representatively shows a top plan view of another exemplary engraved roll for use in manufacturing tissue products.
FIG. 11 representatively shows a tissue product manufactured using the engraved roll of FIG. 10 and treated with osmiun tetroxide to stain the additive composition black.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, a method of carrying out this invention will be described in greater detail. FIG. 1 describes a process for making uncreped throughdried base sheets suitable for off-line application of the heated additive compositions. Shown is a twin wire former having a layered papermaking headbox 1 which injects or deposits a stream of an aqueous suspension of papermaking fibers onto a forming fabric 2 . The resulting web is then transferred to a fabric 4 traveling about a forming roll 3 . The fabric 4 serves to support and carry the newly-formed wet web downstream in the process as the web is partially dewatered to a consistency of about 10 dry weight percent. Additional dewatering of the wet web can be carried out, such as by differential air pressure, while the wet web is supported by the forming fabric.
The wet web is then transferred from the fabric 4 to a transfer fabric 6 traveling at a slower speed than the forming fabric in order to impart increased MD stretch into the web. A kiss transfer is carried out to avoid compression of the wet web, preferably with the assistance of a vacuum shoe 5 . The web is then transferred from the transfer fabric to a throughdrying fabric 8 with the aid of a vacuum transfer roll 7 or a vacuum transfer shoe. The throughdrying fabric can be traveling at about the same speed or a different speed relative to the transfer fabric. If desired, the throughdrying fabric can be run at a slower speed to further enhance MD stretch. Transfer is preferably carried out with vacuum assistance to ensure deformation of the sheet to conform to the throughdrying fabric, thus yielding desired bulk, flexibility, CD stretch and appearance.
The level of vacuum used for the web transfers can be from about 3 to about 15 inches of mercury (75 to about 380 millimeters of mercury), preferably about 10 inches (254 millimeters) of mercury. The vacuum shoe (negative pressure) can be supplemented or replaced by the use of positive pressure from the opposite side of the web to blow the web onto the next fabric in addition to or as a replacement for sucking it onto the next fabric with vacuum. Also, a vacuum roll or rolls can be used to replace the vacuum shoe(s).
While supported by the throughdrying fabric, the web is final dried to a consistency of about 94 percent or greater by a throughdryer 9 and thereafter transferred to an upper carrier fabric 11 traveling about roll 10 .
The resulting dried basesheet 13 is transported between upper and lower transfer fabrics, 11 and 12 respectively, to a reel 14 where it is wound into a roll 15 for subsequent printing of the heated additive composition and further converting.
FIG. 2 depicts off-line printing, in which the printing operation is carried out independently of the tissue sheet manufacturing process. The sheet being printed with the melted additive composition can be single ply or it can be multiple plies. Shown is a roll 20 of the tissue to be treated being unwound. The tissue sheet 21 is passed to a heated gravure printing station comprising a backing roll 22 and an engraved roll 23 , at which point the treating composition is applied to one surface of the tissue. The resulting sheet is then wound into a roll 24 for further converting operations.
During the printing operation, the melted composition to be applied to the tissue sheet is supplied by a heated supply tank 25 and pumped to a heated doctor application head 26 by a suitable metering pump. It is desirable to maintain constant temperature in the process. Accordingly, the melted composition may be continually circulated between the supply tank and the application head while maintaining an adequate amount in the reservoir. The heated doctor applicator head supplies the melted composition to the engraved roll 23 , the surface of which contains a plurality of small cells separated into groups to form the primary and supplementary delivery zones on the final tissue product. As previously noted, the configuration and add-on rates of the primary and supplementary zones are selected to provide the transfer volume necessary to achieve the desired tactile effect. The engraved roll 23 will be discussed in greater detail hereinafter in relation to FIGS. 8-11.
In operation the engraved roll 23 is loaded to the backing roll 22 to force the tissue web or sheet into contact with the engraved roll. The backing roll can be any material that meets the process requirements such as natural rubber, synthetic rubber or other compressible surfaces. Loading pressures can vary from approximately 5-50 pounds per lineal inch (roll to roll interference) to a gravure roll/backing roll gap of 0.008″ (no roll to roll contact).
FIG. 3 is similar to FIG. 2, but illustrates two-sided direct heated rotogravure printing of the sheet using two printing stations in sequence. Two-sided printing is desirable when the effect of the composition is desired on both sides and/or the tissue sheet consists of two or more plies.
FIG. 4 represents two-sided printing of the tissue sheet using an offset heated gravure printing method on one side of the sheet and a direct heated gravure printing method on the other side of the sheet. In this method, the engraved roll 23 and the backup roll 22 (now doubling as an offset applicator roll) can be the same as the rolls used for the previously described methods. However, a second engraved roll 30 requires different liquid delivery characteristics and thus is engraved slightly differently. For such rolls, for example, the direct engraving specifications for the primary delivery zones can be 200 line screen, 5.0 BCM. Typical cell dimensions for such a roll can be 150 microns in length, 110 microns in width, and 30 microns in depth. The offset engraving specifications for the primary delivery zones can be 250 line screen, 4.0 BCM, 140 microns in length, 110 microns in width, and 26 microns in depth. The engraving specifications for the supplementary delivery zones can be adapted to provide relatively lower add-on amounts.
FIG. 5 represents a method of printing both sides of the sheet using simultaneous heated offset gravure printing.
FIG. 6 represents a method of printing both sides of the sheet in succession using two heated offset gravure printing stations. For each printing station, the addition of a backing roll 31 is necessary.
FIG. 7 is similar to FIG. 1 except that the dried basesheet 13 is transported to a heated rotogravure printing station comprising backing roll 22 and engraved roll 23 , at which point the additive composition is applied to one surface of the sheet. The treated uncreped throughdried tissue sheet is then wound into a roll 15 for subsequent converting operations.
One exemplary engraved roll 23 A suitable for use in applying additives to facial tissue in zones of differing add-on amounts is shown in FIG. 8 . The engraved roll is engraved with two different regions of cell patterns. A primary region 40 has a line screen of 200 cells per lineal inch. Each cell has a volume of 5.0 billion cubic microns (BCM) per square inch of roll surface, with typical dimensions of 180 microns in length, 143 microns in width, and 30 microns in depth. The resulting additive deposits are approximately 2.2 gsm. The primary region 40 is laterally surrounded by a pair of supplementary regions 42 . The supplementary regions 42 each have a line screen of 390 cells per lineal inch. The cells in the supplementary regions 42 have a volume of 1.5 BCM per square inch of roll surface, and typical dimensions of 110 microns in length, 65 microns in width, and 18 microns in depth. The additive deposits resulting from the supplementary regions 42 are approximately 0.42 gsm.
The combined regions 40 and 42 represent the print coverage width of facial tissue, approximately 8.5 inches. The primary region 40 is positioned in the center 5.5 inches of the tissue and covers approximately 65 percent of the planar surface area of the tissue. The supplementary regions 42 are each 1.5 inches in width and cumulatively cover approximately 35 percent of the planar surface area.
FIG. 9 representatively shows a facial tissue 44 that would result from using the engraved roll 23 A of FIG. 8 . The tissue 44 is illustrated as having been treated with osmiun tetroxide to stain the additive composition black. The result of the treatment shows a central primary delivery zone 46 that is a darker shade than a pair of laterally spaced supplementary delivery zones 48 . In FIGS. 9 and 11 darker shading is illustrated by more closely spaced cross hatching lines. The darker shade indicates the presence of more additive in the primary delivery zone 46 than in the supplementary delivery zones 48 . The primary delivery zone 46 is centrally located to maximize the opportunity for additive to contact the skin of the user. The supplementary delivery zones 48 are uniformly coated with the same additive that is present in the primary delivery zone, but at a reduced amount. This allows the supplementary delivery zones to provide some benefit, but most importantly does not drastically detract from the benefit delivered by the primary delivery zone. In one embodiment, the tissue 44 does not include additive void areas, for it is hypothesized that such void areas when used as an alternative to supplementary delivery zones significantly diminish the effectiveness of the primary delivery zone.
FIG. 10 shows another exemplary engraved roll 23 B suitable for use in applying additives to facial tissue in zones of differing transfer. The engraved roll includes an alternating pattern of two different regions of cell patterns. A plurality of primary regions 50 deliver additive deposits at approximately 2.2 gsm, and a plurality of supplementary regions 52 deliver additive deposits at approximately 0.42 gsm. These regions 50 and 52 , have the same line screen, cell volume, and dimensions, respectively, as those described above in relation to the primary and secondary regions 40 and 42 of FIG. 8 .
The combined regions 50 and 52 in FIG. 10 have a print coverage width of approximately 8.5 inches. The seven primary regions 50 are each approximately 0.75 inch wide, and cumulatively cover approximately 62 percent of the planar surface area of the tissue. The eight supplementary regions 52 are each 0.41 inch wide and cumulatively cover approximately 38 percent of the planar surface area.
FIG. 11 representatively shows a facial tissue 54 that would result from using the engraved roll 23 B of FIG. 10 . The tissue 54 is illustrated as having been treated with osmiun tetroxide. The tissue includes seven distinct primary delivery zones 56 that appear darker than eight supplementary delivery zones 58 . The primary delivery zones tend to mask the reduced amount of additive in the supplementary delivery zones. The placement of the supplementary delivery zones adjacent and laterally outward from the primary delivery zones maintains the benefits resulting from the primary delivery zones.
Although FIGS. 8 and 10 both show striped zones that are continuous in one direction, it is possible to obtain changes in the additive application rate using different methods. For example, a block, circle, or other shaped zone could be introduced to repeat at specified intervals.
EXAMPLE
The following example serves to illustrate possible approaches pertaining to the present invention. The particular amounts, proportions, compositions and parameters are meant to be exemplary, and are not intended to specifically limit the scope of the invention.
A skin-moisturizing formula was prepared having the following composition:
Weight Percent
1.
Dimethicone 100 cst
1.0
2.
Isopropyl Palmitate
3.0
3.
Vitamin E Acetate
0.1
4.
Aloe Extract
0.1
5.
Mineral Oil
59.8
6.
Ceresin Wax (M.P. 66-71° C.)
18.0
7.
Cetearyl Alcohol
18.0
The formulation was prepared by premixing the dimethicone and the isopropyl palmitate until uniform. While heating, the aloe vera extract and the vitamin E extract were added and mixed. Mineral oil was added and the formulation was mixed until uniform. The mixture was further heated to a temperature of 55-60°C. The ceresin wax was added. The mixture was further heated to 60-65°C. with agitation until the ceresin wax was melted. Cetearyl alcohol was slowly added to the mixture while maintaining agitation to avoid clumping. The temperature was maintained at about 55-60 °C. and mixing continued until the cetearyl alcohol was melted. At this point the formulation was ready for use.
The skin-moisturizing formulation was applied to both surfaces of an uncreped throughdried two-ply tissue basesheet (basis weight of about 25 pounds per 2880 square feet) via a simultaneous heated rotogravure printing process at an add-on level of 8.6 weight percent total add-on as described in relation to FIG. 5 . Specifically, the formulation was pre-melted at about 56°C. in a stainless steel heated supply tank. The press supply system and press (supply hoses, doctor application heads, and gravure rolls) were preheated to about 55°C. The formulation was transferred from the heated application heads to the heated offset/offset gravure rolls.
The gravure rolls were electronically engraved, chrome over copper rolls supplied by Southern Graphics Systems, Louisville, Ky. Each heated gravure roll included two different cell patterns as illustrated in FIG. 8. A centrally-located primary region had a line screen of 200 cells per lineal inch and a volume of 5.0 BCM per square inch of roll surface. Typical cell dimensions for this roll were 180 microns in length, 143 microns in width, and 30 microns in depth. This primary region was laterally surrounded by a pair of supplementary regions, each having a line screen of 390 cells per lineal inch and a volume of 1.5 BCM per square inch of roll surface. Typical cell dimensions for this roll were 110 microns in length, 65 microns in width, and 18 microns in depth. The stylus angle was set at 135 degrees for the primary region and 145 degrees for the supplementary regions. The rubber backing offset applicator rolls were a 75 Shore A durometer cast polyurethane supplied by American Roller Company, Union Grove, Wis.
The process was set up to a condition having 0.375 inch interference between the gravure rolls and the rubber backing rolls, and 0.003 inch clearance between the facing rubber backing rolls. The simultaneous offset/offset heated gravure printer was run at a speed of 1500 feet per minute. The composition deposits solidified substantially instantaneously after exiting the press.
When cut into individual facial tissue sheets and tested by a trained consumer panel, the resulting tissue product was shown to have comparable tissue softness qualities while being perceived to have better wicking, more absorption, and improved strength when wetted when compared to comparable uncreped throughdried facial tissues having a generally uniform additive application at an add-on level of 10.3 weight percent total add-on. The tissues incorporating the primary and supplementary delivery zones also provide a significant cost advantage of the uniform additive application tissues, due to the multiple add-on level tissues including 16 percent less additive.
It will be appreciated that the foregoing example, given for purposes of illustration, is not to be construed as limiting the scope of this invention, which is defined by the following claims and all equivalents thereto.
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A soft uncreped throughdried tissue product includes a distribution of surface deposits of an additive composition adapted to reduce skin irritation and redness or otherwise deliver a benefit to the user. An array of primary delivery zones with a relatively high additive add-on amount in combination with supplementary delivery zones with a relatively lower add-on amount effectively maximize consumer benefit while minimizing the total amount of additive on the tissue.
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FIELD OF THE INVENTION
The present invention relates to a manhole cover for refueling locations such as service stations, petroleum fuel depots, airports and other private transportation areas. In particular, the invention relates to a replacement manhole cover made essentially of composite material.
BACKGROUND OF THE INVENTION
Manholes are located at refueling locations to provide access to underground tanks, pumps, meters and related services for the petroleum industry. The manholes include an annular metal frame attached around the periphery of the manhole. The existing frame provides a shelf for supporting a manhole cover. The shelf has a depth such that the top of the manhole cover lies essentially on the same plane as the surrounding surface.
Traditionally, manhole covers are manufactured from steel to provide a cost effective access means to the underground services that can withstand significant loads. However, these existing manhole covers are made from materials that are extremely heavy, making access to the manhole by a single person difficult, as well as not meeting OSHA requirements. As a result, it is desirable to replace these heavy metal manhole covers with a cover design made up of both lightweight composite and steel material. Further, it is desirable to maintain the same strength and durability as the traditional metal manhole covers while continuing the flush surface of the manhole cover with the surrounding surface.
Inevitably, the thickness of a substitute resin or other lightweight composite material used for a manhole cover will necessarily need to be thicker in order to provide the same physical strength attributes of the traditional steel manhole cover. Therefore it is necessary to provide a suitable adapter to the existing frame that will provide a support for a thicker composite manhole cover.
The widely accepted criterion for United States highway traffic loading as included in Standard Specifications for Highway Bridges published by AASHTO (American Association of State Highway and Transportation Officials) is now being applied under federal guidelines to composite manhole covers used by the petroleum industry in service stations, petroleum fuel depots, airports, and other private transportation areas like shopping centers and convenience stores related to re-fueling location applications. In the overseas market, the European standard EN124 applies. Both of those standards define compliance for the two axle truck and the tractor trucks with a tandem axle semi-trailer loading condition. For both standards, the maximum axle load requiring support in actual practice is 32,000 pounds or 16,000 pounds for each set of dual tire wheels. The latter figure is by definition the design limit for every manhole cover manufactured in the U.S. In the case of overseas shipments, EN124 requires that manhole covers must withstand a maximum loading of 18,827 pounds for the classification that applies to manholes used in petroleum industry applications as defined above. In addition, there are two critical safety design aspects for composite manhole covers. They include strength failure and flatness failure. Strength failure is due to stresses from vehicle traffic exceeding the ultimate vertical loading strength of the composite manhole cover for any diameter and thickness. Flatness failure is the permanent "dishing" of the composite cover resulting in an unsafe rocking condition while setting in the steel rim skirt assembly.
SUMMARY OF THE INVENTION
It is the intent of the subject invention to address the aforementioned concerns by providing a manhole cover made of a composite material that is a lighter weight than the traditional steel or other metal manhole covers. In particular, it is the intent to provide a manhole cover assembly that is approximately half the weight of the current steel manhole cover. It is further an intent, of this invention to provide a composite material manhole cover that meets the aforementioned safety designs, as well as meets federal and European standards. It is additionally the intent of this invention to provide a simple and quick replacement for the metal manhole cover that can be accommodated in the existing fixed-in-place frame surrounding the periphery of the manhole that provides direct replacement for an existing steel manhole cover.
The intent is to replace the current heavy manhole covers with a more lightweight and accessible manhole cover. A thicker composite lid is used for placement over the manhole. In order to support the composite manhole cover upon the existing frame located in the manhole, an annular adjustment skirt is provided for placement over the existing frame in the manhole. The skirt includes an upper lip for placement to rest on a shelf of the existing frame in the manhole. The skirt further includes a vertical drop extension. The vertical drop extension terminates at a horizontal shelf. The length of the drop extension is sized to accommodate the increased thickness of the manhole cover by using a composite material.
The composite material manhole cover is then placed on the shelf formed by the annular skirt which allows for a greater depth to accommodate the thickness of the composite material used for the cover.
Other objects, advantages and applications of the present invention will become apparent to those skilled in the art when the following description of the best mode contemplated for practicing the invention is read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1, is an exploded and perspective view of a replacement manhole cover according of the subject invention;
FIG. 2, is a fragmentary vertical cross-sectional view of the manhole cover;
FIG. 3, is a fragmentary vertical cross-sectional view of a second embodiment of the invention; and
FIG. 4, is a fragmentary vertical cross-sectional view of the subject invention with a watertight feature.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1-3, an existing manhole will include a fixed-in-place annular manhole cover frame 10 that is recessed into the ground surface and held in place by suitable material such as concrete. An upper horizontal surface 12 of frame 10 is generally at the same level as the adjacent road or pavement 14. Inwardly from the horizontal surface 12 is a vertical surface 16 terminating at a second horizontal surface 18 inwardly of the first horizontal surface 12. The second horizontal surface 18 is at a location vertically lower than the upper horizontal surface 12. The second horizontal surface 18 defines a shelf upon which the existing steel manhole cover rests. The intent of this invention is to simple replace the heavy steel manhole cover with a lighter composite material manhole cover. Inevitably, in order to provide the same durability and strength in the composite manhole cover as was previously experienced in the metal manhole cover, it is necessary to provide a thicker manhole cover. The composite manhole cover 30 will be approximately one inch thick. As a result a composite manhole cover 30 providing the same specifications as the previous metal manhole cover would be raised above the surface of the surrounding roadway or pavement when placed on shelf 18. Therefore, it is necessary to lower the shelf height for placement of the composite manhole cover 30.
An annular adaptor skirt 20 is provided for placement in the manhole and on the manhole frame 10 such that the annular skirt 20 provides a lower shelf for retaining a thicker composite manhole cover 30. The annular skirt 20 includes an outer vertical surface 22 and an inner vertical surface 24. The inner vertical surface 24 terminates at an inner horizontal surface 26. The inner horizontal surface 26 defines a replacement shelf 26 located at a lower height when installed in the manhole for receiving the composite manhole cover 30. The dimension of the annular skirt 20 is such that the upper vertical surface 22 of the skirt is slidable engaged along vertical surface 16 of the existing frame 10. There is enough clearance between the vertical section 22 on the annular skirt 20 and the vertical section 16 of the existing frame 10 such that fingers or another tool may fit therebetween to lift the annular skirt away from the fixed frame 10. Looking at FIGS. 2 and 3, when the annular skirt 20 is located on the horizontal surface 18 of the existing frame 10 the upper surface 28 of the annular skirt 20 is essentially flush or slightly below that of surface 12 of frame 10 as well as the surrounding pavement 14. The vertical wall 24 of the annular skirt 20, essentially defines the depth of the replacement shelf 26 for receiving the composite manhole cover 30 so that it is not above the adjacent road 14. Another exterior horizontal surface 25 adjacent vertical wall 24 of the annular skirt 20 is received within the inner periphery 17 of the fixed frame 10. A lower surface 27 on annular skirt 20 adjacent horizontal surface 28 rests against the shelf surface 18 of the existing frame 10 to support the skirt 20.
The composite manhole cover 30 has an outer annular peripheral wall 32 that is sized to be accommodated and received within the annular vertical wall 24 and on the replacement shelf 26 of the annular skirt 20. The upper horizontal surface 34 of the composite manhole cover 30 will therefore be essentially flush with the upper horizontal surface 28 of the annular skirt 28 as well as the surrounding pavement 14.
As can be seen in FIGS. 2 and 3, the annular skirt 20 can have varying configurations. The annular skirt 20 in FIG. 2 is constructed of a 0.750 by 0.375 inch bar stock shaped to form an annular upper portion of the skirt 20. A 1.25 inch by a 1.25 by 0.25 angle bar formed to corresponding annular shape is welded to the inner surface of the first bar piece. This angle piece forms the shelf 26 for receiving the composite manhole cover 30.
In FIG. 3, a 5/8 inch thick bar stock is shaped to form the outer diameter surface of the annular skirt such that it is flushed with the surrounding roadway. A 3/8 inch bar stock is annularly configured and welded to the lower surface at the innermost periphery of the 5/8 inch bar stock. A 3/8 inch bar stock approximately 1 inch long is also formed to a corresponding annular shape and is then welded to the small 3/8 inch bar stock to form a shelf for receiving the composite manhole cover 30. Other modifications of the metal bar stock may form the skirt 20 and the shelf 36 for the composite manhole cover 30.
FIG. 2 further shows a bolt down version of the composite manhole cover 30 which includes a threadable hex nut 40 which is received in apertures 42 through the composite manhole cover 30 and through shelf portion 26 of the annular skirt 20. The hex nut 40 then may be welded as shown at 44 to secure the composite manhole cover 30 in place. FIG. 4 further shows a modification including a watertight feature, such that a water resistant annular gasket 46 is place on the outer perimeter of the replacement shelf 26. The composite manhole cover 30 sets on the gasket 46 within the annular skirt 20.
The composite manhole cover 30 is manufactured to withstand over 30,000 pounds of loading without any cover damage. A resin transfer molding process is used for the production of the composite manhole cover 30. The process includes positioning continuous strand and woven mats of glass fiber layers 50 designed for the specific product in an open mold. A matching second half mold is mated to the first half model and clamped together. A catalyst resin 52 mix specifically designed for the composite manhole cover 30 is pumped into the cavity. The mold is allowed to cure before removing the part from the mold set.
For installation of the manhole cover assembly, the annular skirt 20 needs to be installed at grade height. The grade should run slightly downward away from the manhole location. The installation of the annular skirt 20 must include maintaining the roundness and the flatness of the assembly to insure that the composite manhole cover 30 has a proper flat and round mating surface 26 that is free of any debris. If the assembly is a bolt down or watertight configuration, then the assembly must be installed with the composite manhole cover 30 in the secured position. The hex cap screws 44 should be tighten only snug fit. Manhole covers 30 should be repositioned carefully, as marked if removed from the annular skirt 20.
To ensure competent information, impartial independent outside testing was conducted. This study's purpose for composite covers was to apply both the U.S. Federal Specification RR-F-621 (federal specification for frames, covers, gratings, steps, sump, and catch basins, manholes) and the European standard EN124 (gully tops and manhole tops for vehicular and pedestrian areas--design requirements, type testing, marking, quality control) to composite manhole covers for load rating compliance. To make certain those results could be compared worldwide to other composite manhole manufacturers, the Enneking test study included the following elements: a) covers to be tested were randomly selected from those manufactured, b) various sample sizes and configuration were tested with vertical center loading applied for a period of five minutes per load increment over the load range of interest, c) detailed material testing was performed to verify glass fiber strength, and d) high and low experimental temperature variations were investigated.
While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be 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, which scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures as is permitted under the law.
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A replacement manhole cover assembly for an existing manhole having a fixed frame around the periphery of the manhole, the frame having an upper horizontal lip essentially flush with the surrounding pavement and a lower horizontal shelf, wherein the replacement manhole cover assembly includes an annular skirt selectively removable on the lower horizontal shelf of the frame, the skirt having a vertical extension terminating at a lower horizontal shelf for supporting a manhole cover made of composite material.
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BACKGROUND OF THE INVENTION
The present invention relates to a method and device in a size press in which a nip is formed by a pair of press rolls. A paper or board web is passed through the nip. A first press roll is permanently mounted, or fixed, by means of bearings on a frame of the size press, while a second press roll is mounted on the frame of the size press by means of additional bearings. The second press roll is displaceable by means of loading arms or equivalent loading means. The press rolls are coated by means of coating devices which spread films of a coating agent onto the faces of the rolls. The coating devices are mounted on applicator beams arranged transverse to the machine direction. The applicator beams are supported pivotally on the frame of the size press or on the loading arms of the displaceable roll and are provided with pivot cylinders. By means of the pivot cylinders, the applicator beams can be opened and closed in relation to corresponding press rolls against which the coating devices operate. In addition, the applicator beams are provided with catches arranged to be supported directly or indirectly on the bearings of corresponding rolls when the applicator beams are being closed by means of the pivot cylinders.
In the prior art, it is a typical construction of modern size presses that the size press comprises a pair of rolls which form a nip through which a paper or board web is passed. A coating agent, such as a size or pigment coating, is applied as a film onto the faces of the rolls by means of application devices. The coating agent is transferred onto the web to be coated in the roll nip. Normally, one roll in the pair of rolls is permanently mounted, i.e. fixed, on the frame of the size press by means of bearings, whereas the other roll is mounted on the frame displaceably, e.g., by means of pivot arms. The pivot arms permit the nip to be opened and the press roll to be loaded against one another so as to produce a desired nip pressure.
A significant disadvantage of the size-press construction described above is manifested in particular in connection with the replacement of the rolls. In particular, when the fixed roll is replaced, the new roll is not always positioned optimally on the frame of the size press, rather it may remain slightly inclined. When the nip is closed, the displaceable roll is positioned in a way corresponding to the fixed roll to produce a uniform nip pressure. Thus, the displaceable roll is also positioned in an inclined manner in a way corresponding to the fixed roll.
The application devices of the rolls are typically mounted on an applicator beam arranged transverse to the machine direction. The applicator beam is linked pivotally on the frame of the size press or on the loading arm of the displaceable roll. The applicator beam is usually provided with pivot cylinders, by whose means the beam and the coating device mounted on the beam are "closed" against the corresponding roll, i.e. to form a nip. However, the construction of the applicator beam is very rigid, for which reason it cannot always be positioned by means of its pivot cylinders in a manner corresponding to the positions of the rolls.
An applicator beam is generally provided with mechanical catches, which rest against catch faces formed on the bearing housings of the roll when the beam is closed. If the roll has been positioned in a highly inclined position, upon closing of the beam, a situation may arise in which the catch placed at one side of the beam only reaches contact with the bearing housing of the roll. Therefore, a gap remains between the catch placed at the opposite side and the catch face formed on the bearing housing. Even if the coating member of the coating device could be placed correctly against the roll face, by means of its loading hose, the pivot cylinders of the applicator beam usually produce an error in the nip pressure. This error is increased linearly in the transverse direction of the machine and has a highly detrimental effect on the coating result produced by the application devices on the press rolls.
Hydraulic catches have also been applied in applicator beams of size presses. In their simplest form, they consist of a hydraulic cylinder whose length can be adjusted, i.e., a "jack". By adjusting the length of the hydraulic cylinders, both ends of the applicator beam can be made to rest against the catch faces formed on the bearing housings of the roll. However, the drawbacks related to such a solution are similar to those of the mechanical catches described above, i.e., the regulation is difficult, because the two catches must be adjusted separately. The support forces of both of the catches would have to be adjusted equal in order to prevent the pivot cylinders of the applicator beam from producing an error in the nip pressure. More "advanced" hydraulic catches invariably involve complicated control and regulation circuits, which are also expensive. Also, hydraulic systems always involve an unpredictable risk of leakage.
OBJECTS AND SUMMARY OF THE INVENTION
An object of the present invention is to provide a solution by whose means the above drawbacks related to the prior art are avoided.
It is another object of the present invention to provide a new and improved size press by means of which an improved coating result is obtained.
It is yet another object of the present invention to provide a new and improved size press wherein the nip pressure of a pair of rolls in the size press can be regulated to control the thickness of the coating on the paper web or board passing through the nip.
In view of achieving these objects, and others, in the present invention, at least one of the applicator beams of the size press is provided with catches placed at each end of the applicator beam and positioned in accordance with the position of the applicator beam. The catches are attached to the applicator beam by means of articulated joints and are interconnected mechanically.
It is an important advantage of the present invention, when compared with the prior art devices, that the load of the size nip in the size press, i.e. the nip pressure, is substantially uniform and controlled. As a result, the thickness of the layer of the coating agent on the paper or board web to be coated can be made as desired across the width of the web. In comparison with hydraulic systems, a further advantage of the present invention is low cost and simplicity.
Briefly, the device in accordance with the invention includes a frame section having press rolls arranged thereon, and applicator beams arranged to operate against respective press rolls. At least one of the applicator beams has a first and second catch arranged at a first and second end thereof, respectively. The first and second catches are connected and attached to the at least one applicator beam by means of articulated joints and are arranged with respect to a desired position of the at least one applicator beam. Pivot cylinders are arranged between the frame and the applicator beams for pivoting the applicator beams between a closed position against a respective press roll and an open position away from the respective press roll.
The press rolls form a nip therebetween through which a paper web or board passed. A first press roll is fixed by means of bearings on the frame of the size press. A second press roll is mounted on the frame of the size press by means of additional bearings and is displaceable by loading means. The press rolls are coated by coating devices arranged to spread films of a coating agent onto the faces of the press rolls. The applicator beams can be supported on the frame of the size press or on the loading means of the second press roll.
In a preferred embodiment, the device includes supports rigidly connected to the bearings of the second press roll, and connecting means, i.e. an intermediate member, to connect both catches of the applicator beam. Each of the catches comprises a lever linked with the at least one applicator beam by means an articulated joint, and a cam arranged at one end of the lever such that the cam is supported during the closing of the applicator beam against a respective one of the supports. The intermediate member is arranged to connect both catches at an opposite end of the lever.
The method in accordance with the invention provides a substantially uniform pressure in a nip in a size press in which press rolls form the nip through which a paper or board web is passed. In the method, a pair of press rolls form a nip and coating devices are arranged to spread a coating agent onto faces of the press rolls. The coating devices having applicator beams arranged to operate against a respective press roll. At least one of the applicator beams is provided with a pair of lever-shaped catches at a first and second end thereof which are connected to each other. As such, a load is applied to one of the catches during a closing operation of the at least one applicator beam and causes the catch to pivot about a support. In this manner, the other catches will also be moved to rest against a corresponding support to thereby level the respective press roll and provide a substantially uniform nip pressure during a running operation of the size press.
Additional advantages and characteristic features of the invention will be ascertained from the following detailed description of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The following drawings are illustrative of embodiments of the invention and are not meant to limit the scope of the invention as encompassed by the claims.
FIG. 1 is a fully schematic side view of a size press in which the device in accordance with the invention can be applied.
FIG. 2 is a schematic top view of a size press showing the inclined positioning of the press rolls and a potential resulting error in the nip pressure.
FIG. 3 is an enlarged detail of FIG. 1, illustrating the construction of the catches on the applicator beam in a device in accordance with the present invention.
FIG. 4 is a view in the direction A of the construction illustrated in FIG. 3 according to a first embodiment of the invention.
FIG. 5 is a further enlarged detail of the embodiment illustrated in FIG. 4.
FIG. 6 shows an alternative embodiment to that shown in FIG. 4 of a device in accordance with the invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a schematic illustration of a size press which is denoted generally with the reference numeral 10. Press rolls 12,14 are arranged in the size press 10 and form a nip N with one another. A paper or board web W is passed through the nip N. In the embodiment shown in FIG. 1, the web W is passed into the nip N over a guide roll 19. A bearing 13 is connected to the first press roll 12 so that the first press roll 12 is permanently mounted, i.e. fixed, on the frame 11 of the size press. In a corresponding manner, a bearing 15 of the second press roll 14 is mounted on a loading arm 16, which is arranged on the frame 11 of the size press pivotally by means of an articulated joint 18. Loading cylinders 17 are arranged between the frame 11 and the loading arm 16. The loading cylinders 17 open and close the nip N and are arranged to adjust the loading pressure between the rolls 12,14, i.e. the nip pressure, to a desired level.
Each of the press rolls 12,14 in the size press 10 is provided with a coating device 23,23a of its own arranged to coat the respective roll. A film of coating agent is applied to the face of the respective roll 12,14 by the coating devices. The film is transferred onto the web W in the roll nip N. Each of the coating devices 23,23a is mounted on an applicator beam 20,20a arranged transverse to the machine direction. In the embodiment of FIG. 1, the applicator beam 20a of the first press roll 12 is mounted on holders 24a fixed to the frame 11 of the size press. The applicator beam 20a is arranged to pivot by means of an articulated joint 21a. Pivot cylinders 22a are arranged between the applicator beam 20a and the frame 11 of the size press. By means of the pivot cylinders 22a, the applicator beam 20a can be opened and closed in relation to the roll 12.
In a corresponding manner, the coating device 23 of the second press roll 14 is mounted on an applicator beam 20 arranged transverse to the machine direction. Applicator beam 20 is mounted pivotally on holders 24 fixed to the loading arm 16 by means of an articulated joint 21. Pivot cylinders 22 are arranged between the applicator beam 20 and the loading arm 16. The applicator beam 20 can be opened and closed in relation to the second press roll 14 by means of the pivot cylinders 22.
When the rolls in a size press as illustrated in FIG. 1 have to be replaced, it is highly probable that the first roll, i.e. the fixed press roll 12, is probably not positioned exactly in the optimal, transverse position but rather has become slightly inclined. This situation is illustrated by means of the schematic diagram in FIG. 2, wherein the inclination of the first press roll 12 has been exaggerated considerably. When the first press roll 12 is inclined in the manner shown in FIG. 2, the second press roll 14 is, of course, also positioned at a similar inclination when the nip N is closed by means of the loading cylinders 17. Thus, equal forces are transmitted to the nip N from both loading cylinders 17 such that the forces produced by the loading cylinders 17 produce a substantially uniform nip pressure, i.e. a uniform distribution of loading pressure, in the nip N. This nip pressure is denoted in FIG. 2 with the reference P 1 .
In the position in which the applicator beam 20 is linked on the frame 11 of the size press, the applicator beam 20 cannot be positioned diagonally in a similar way when it is closed by means of the pivot cylinders 22. This results, in particular, from the high rigidity of the applicator beam 20. If the applicator beam 20 is provided with conventional mechanical catches 40,41, when the beam 20 is closed, one catch 41 is loaded against the catch face formed on the bearing 15 of the press roll. In the worst case scenario, a gap c remains between the catch 40 placed at the opposite side of the machine and the catch face on the bearing 15. In such a case, the force produced by the pivot cylinder 22 at the end next to the gap c of the applicator beam 20 is transferred as a torque along the beam 20 to the other end of the beam and, from there, further to the loading arm 16. As a result, the nip force is increased by the amount P 2 .
In a corresponding manner, at the end next to the gap c, the force produced by the pivot cylinder 22 lowers the nip force by the amount P 3 . In FIG. 2, the transfer of the forces is illustrated by the dashed lines. As a result of this reduction in the nip pressure, the pressure distribution P 2 produced by the pivot cylinders 22 of the applicator beam 20 in the nip N is not even. Rather, it changes, for example, in a linear curve as illustrated in FIG. 2. Thus, the nip pressure is, at one edge of the nip N, substantially higher than at the opposite edge. This has a considerably detrimental effect on the coating result of the press rolls.
In accordance with the present invention, the above problem has been eliminated by means of the arrangement illustrated in FIGS. 3 and 4. FIGS. 3 and 4 illustrate the support arrangement of the applicator beam 20 of the displaceable roll 14, i.e. the roll mounted on the loading arm 16 of the size press. It is important to note that a fully equivalent arrangement can also be accomplished on the applicator beam 20a at the side of the fixed roll 12. As described above, the applicator beam 20 is mounted pivotally, by means of the articulated joint 21, on the holders 24,44. The applicator beam 20 and the coating device 23 arranged thereon can be pivoted by means of the pivot cylinders 22 arranged between the coating position, i.e. the closed position, shown in FIG. 3 and the open position.
In the embodiments illustrated in FIGS. 3 and 4, lever-shaped catches 27,47 in a device in accordance with the invention are arranged on a wall 26 of the applicator beam 20 facing the roll 14 and in the area of each end of the applicator beam 20 in the direction of width of the machine. The catches 27,47 are linked to the wall 26 of the applicator beam by means of articulated joints 28,48 so that the lever-shaped catches 27,47 can pivot around the articulated joints 28,48.
At a first end of each of the lever-shaped catches 27,47, a cam 29,49 is formed. The cam 29,49 rests against a support 25,45 arranged on each holder 24,44 when the applicator beam 20 is in the closed position. Thus, by means of the holders 24,44 and the loading arm 16, the position of the supports 25,45 is fixed in relation to the bearing 15 of the roll 14. A connecting link 30,50 is arranged at the second end of each of the catches 27,47, i.e. at the opposite side of the articulated joint 28,48 with respect to the cam 29,49. By means of the connecting links 30,50, the catches 27,47 are interconnected by means of a pulling member, or connecting rod 35, which is preferably a rigid connecting rod as shown in the embodiment of FIG. 4.
One possible mode of linking the connecting link 30 with the catch lever 27 is illustrated in FIG. 5. In this embodiment, in a similar manner to the embodiment of FIG. 4, the articulation shaft of the connecting link 30 is parallel to the pivot shaft of the articulated joint 28 to thereby form a quadrangle between the articulated joints 28,48 and the connecting links 30,50.
As shown in FIG. 5, a through hole has been formed in each connecting link 30,50 which is perpendicular to the pivot shaft. An inside thread has been formed in the hole. In a corresponding manner, threaded parts 36,56 have been formed on the connecting rod 35 at the connecting links 30,50. The threaded parts 36,56 are of opposite handedness, so that, in the embodiment shown in FIG. 4, when the connecting rod 35 is rotated in one direction, the connecting links 30,50 can be made to approach one another while the catch levers 27,47 rotate around their articulated joints 28,48. In a similar manner, when the connecting rod 35 is rotated in the opposite direction, the connecting links 30,50 move apart from one another. By means of this arrangement, the pre-stress of the catches 27,47 of the applicator beam 20 can be adjusted by simply rotating the connecting rod 35.
The construction of the applicator beam 20 is very rigid with respect to rotation. Thus, in conventional support devices, it is possible for the size press to be configured as shown in FIG. 2, in which the contact is lost between the machine frame and one catch of the applicator beam 20.
However, in contrast to the conventional devices, in the device in accordance with the invention, it is possible to equalize the support forces produced by the pivot cylinders 22. This is achieved by placing the catches 27,47 at each end of the applicator beam 20 and interconnecting them by means of articulated joints in the manner in accordance with the invention. In such an embodiment, if the roll 14 has been placed diagonally as shown in FIG. 2, when the application beam 20 is being closed, a situation arises in which the cam 49 of the second catch 47 meets the support 45 on the holder 44 first. When this happens, the second catch 47 pivots around its articulated joint 48 and, at the same time, turns the first catch 27 by means of the connecting rod 35, so that the cam 29 of the first catch moves closer to the support 25 provided on the holder 24 and finally into contact with the support 25.
After the closing of the applicator beam 20 has been completed, both of the catches 27,47 are in contact with the supports 25,45 with a substantially equal support force. In this case, the support forces produced by the pivot cylinders 22 are equal at each end of the applicator beam 20. Thus, when the pivoting movement of the applicator beam has been completed, the beam is placed in its adjusted position in relation to the roll 14. The kinetic energy of the pivoting movement of the applicator beam 20 is absorbed by means of shock absorbers (not shown), but it is also possible to arrange the shock absorption means on the connecting rod 35 itself.
FIG. 4A shows an alternative embodiment to the embodiment shown in FIG. 4. The elements of the embodiment of FIG. 4A which are the same as the elements in FIG. 4 as described above, have been denoted with a prime notation, unless otherwise indicated. In the embodiment of FIG. 4A, the applicator beam is denoted with the reference numeral 20' and the coating device with the numeral 23'. Lever-shaped catches 27',47' are mounted as mirror images, when compared with the embodiment of FIG. 4, in relation to the vertical axes running through articulated joints 28',48'. An intermediate member 35' acts as the member that receives the compression force. Reference numerals 24',44' refer to the holders, and reference numerals 30',50' refer to the connecting links. The threaded parts of the intermediate member 35' are denoted with reference numerals 36',56' the cams of the catches 27',47' with reference numerals 29',49' and the supports on the holders 24',44' with reference numerals 25',45'. Reference numeral 26' refers to the wall of the applicator beam 20'.
In the embodiment of FIG. 4A, the member 35' that receives the compression force can be substituted for by a pulling member, such as a wire (not shown), which interconnects the connecting links (30',50') and passes, e.g., over reversing pulleys, which are placed outside the connecting links 30',50' in the direction of width of the applicator beam 20'.
FIG. 6 shows a further alternative embodiment to the embodiment shown in FIG. 4. In FIG. 6, the dashed lines and reference numerals 27" and 47" represent the catch ends next to the connecting links. The connecting links are denoted in the figure with reference numerals 30" and 50". The embodiment shown in FIG. 6 differs from the embodiment of FIG. 4 in the respect that, in FIG. 6, the connecting rod 35 as shown in FIG. 4 has been substituted for by a wire 35" or by an equivalent flexible pulling member. Moreover, as is shown in FIG. 6, a length-adjusting device 37" is arranged at one end of the pulling member 35". By means of the length-adjusting device, it is possible to carry out the necessary regulation of the pre-stressing. In regard to the principles of operation, the embodiment of FIG. 6 is similar to the embodiment shown in FIG. 4. Thus, the wire 35" is provided with length-adjusting means to vary the relative distance between the connecting links 30",50" of the catches 27",47".
The examples provided above are not meant to be exclusive. Many other variations of the present invention would be obvious to those skilled in the art, and are contemplated to be within the scope of the appended claims.
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A device in a size press comprising a nip formed by press rolls through which a paper or board web is passed. The press rolls are provided with coating devices for spreading films of a coating agent onto faces of the press rolls. The coating devices are mounted on applicator beams arranged transverse to the machine direction. The applicator beams are supported pivotally on the frame of the size press or on the loading arms of a displaceable press roll and are provided with pivot cylinders by which the applicator beams can be opened and closed in relation to the rolls corresponding to them. The applicator beams are further provided with catches supported directly or indirectly on bearings of the corresponding press rolls when the applicator beams are being closed by the pivot cylinders. At least one of the applicator beams of the size press is provided with catches at each end of the applicator beam and positioned in accordance with the position of the applicator beam. The catches are attached to the applicator beam by articulated joints and are interconnected mechanically.
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RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application Ser. No. 60/799,593 filed May 10, 2006 entitled “Full Coverage Perforated Splash Plate for Leaching Chamber”, the contents of which are incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] This invention relates generally to leaching chambers and more particularly to a splash plate for an end cap for use with a leaching chamber.
BACKGROUND OF THE INVENTION
[0003] Plastic leaching chambers having an arch shape cross section are known in the art and are commonly buried within trenches that are dug into the soil. Waste water coming from a source, such as a septic tank, is typically conveyed to the first leaching chamber of a string of leaching chambers by means of an inflow pipe, wherein the waste water enters the first leaching chamber via the inflow pipe which is inserted into an opening, or hole, in the end plate or end cap of the chamber. Because the inflow pipe is often inserted into the hole in the end plate at an elevation above the soil, wherein the soil typically lies at the base level of the chamber, the water projects a short distance into the chamber. Unfortunately, as the water flows through the pipe and into the chamber, the force of the water dropping from the pipe onto the soil at the bottom of the chamber can cause erosion of the soil, thus possibly undermining the chamber over time or even causing drain holes to become clogged. One method that has been used to avoid this problem involves placing a flat stone or fabricated plate of plastic or concrete, generally called a splash plate, upon the soil so that the plate lies within the chamber vertically below the place where the inflow pipe discharges.
[0004] Some plastic end caps that are sold in commerce are sold by Infiltrator Systems Inc. of Old Saybrook, Conn. and often include such kind of splash plate, wherein a typical splash plate may be about 6 inches by 8 inches in dimension. The edge of the splash plate may have tabs that mechanically engage the base of the end cap to keep the splash plate from moving over time, such as by floating or by force of the water hitting the splash plate. For example, FIG. 1 illustrates one such splash plate 102 , in accordance with the prior art, associated with an end cap 100 as disclosed in U.S. Pat. No. 7,008,138 to Bumes et al., and is referred to further hereinafter.
[0005] When the waste water flows into the chamber by gravity at a relatively low volumetric flow rate, the water tends to drop vertically downward at the entry point. In this case, the installer may be fairly confident that he knows where to position the splash plate to avoid soil erosion. However, prior art splash plates are not well suited to address the problems that exist when the waste water is sent to the chamber by means of a dosing pump. This is because the volumetric flow rate of the water from the dosing pump may vary from time to time and is typically higher than water flowing solely by gravity. This higher flow rate causes the water to project farther into the chamber and unfortunately, the location of the landing point of the water typically varies from installation to installation and from time to time during use.
[0006] In such situations, it has been found that soil erosion still occurs with the prior art splash plates because the water projected into the chamber either flows rapidly off of the splash plate and into the chamber, only partially lands on the splash plates or overshoots the splash plates altogether. This is undesirable for several reasons. First, because during erosion the soil is washed away and typically flows downstream into the chamber, the eroded soil can clog the drain holes preventing needed flow. Second, in one worse case scenario, as more and more soil at the base level of the chamber erodes, the stability of the chamber can become compromised and if enough soil erodes away, the chambers can shift. Third, in another worse case scenario, if enough soil is eroded such that the soil supporting the end cap could be undermined over time, the end cap could be allowed to shift away from the chamber.
SUMMARY OF THE INVENTION
[0007] In an embodiment, a splash plate for use with an end cap or end portion of a chamber, wherein the end cap or end portion defines an end cavity having an open end cavity bottom and includes an opening for containing a waste water pipe that introduces waste water into the end cavity is provided. The splash plate includes a base panel, wherein the base panel is configured to cover the end cavity bottom when the splash plate is associated with the chamber, such that waste water being introduced into the end cavity contacts the base panel. The splash plate also includes a plurality of upright side portions, wherein each of the plurality of upright side portions is configured to interact with the end cap or end portion when the splash plate is associated with the chamber to inhibit longitudinal motion of the splash plate within the end cavity. Furthermore, the splash plate includes a baffle portion, wherein the baffle portion is configured to interact with the end cap or end portion when the splash plate is associated with the chamber to inhibit lateral movement of the splash plate and longitudinal movement of the baffle portion within the end cavity.
[0008] In another embodiment, an assembly is provided, wherein the assembly includes an end cap or a end portion of a chamber having an interior end cavity with an open end cavity bottom and a base flange. The assembly also includes a splash plate, wherein the splash plate includes a base panel disposed and configured to closely associate with the base flange to cover a substantial portion of the end cavity bottom, such that waste water being introduced into the end cavity contacts the base panel. The splash plate also includes a plurality of upright side portions, wherein each of the plurality of upright side portions is configured to interact with the end cap or end portion to inhibit longitudinal motion of the splash plate within the end cavity. Furthermore, the splash plate includes a baffle portion, wherein the baffle portion is configured to interact with the end cap or end portion to inhibit lateral movement of the splash plate and longitudinal movement of the baffle portion within the end cavity.
[0009] In another embodiment, a splash plate for use with an end cap or end portion of a chamber is provided, wherein the end cap or end portion defines an end cavity having an open end cavity bottom and includes an opening for containing a waste water pipe that introduces waste water into the end cavity. The splash plate includes a base panel for covering the end cavity bottom such that waste water introduced into the end cavity contacts at least a portion of said base panel and a means for positionably securing the splash plate relative to the end cap or end portion.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The foregoing and other features and advantages of the present invention should be more fully understood from the accompanying detailed description of illustrative embodiments taken in conjunction with the following Figures in which like elements are numbered alike in the several Figures:
[0011] FIG. 1 is an isometric view of a splash plate associated with an end cap in accordance with the prior art;
[0012] FIG. 2 is a top down isometric view illustrating a first embodiment of a splash plate, in accordance with the present invention;
[0013] FIG. 3 is a planar view of the splash plate of FIG. 2 in flattened condition, suitable for shipment prior to use and in accordance with the present invention;
[0014] FIG. 4 is an isometric view bottom up view of the splash plate of FIG. 2 associated with an end cap, in accordance with the present invention;
[0015] FIG. 5 is a cross-sectional side elevation view of an end cap and splash plate assembly, in accordance with the present invention, showing an inflow pipe in phantom;
[0016] FIG. 6 is a top down isometric view illustrating a second embodiment of a splash plate, in accordance with the present invention; and
[0017] FIG. 7 is a planar view of the splash plate of FIG. 6 in flattened condition, suitable for shipment prior to use and in accordance with the present invention.
DETAILED DESCRIPTION
[0018] It should be appreciated that the present invention is described herein in terms for use in combination with a molded thermoplastic end cap 100 , such as that shown in FIG. 1 and as disclosed in U.S. Pat. No. 7,008,138 to Bumes et al., issued Mar. 7, 2006 and entitled “Faceted End Cap for Leaching Chamber,” the contents of which are hereby incorporated by reference in its entirety. The end cap 100 includes a dome shaped shell having an interior cavity and at least pull seal tab which can be removed to create at least one opening 106 in the buttress portion 108 of the end cap 100 for receiving at least one waste water pipe. This allows waste water to be introduced or dumped into the interior cavity of the end cap 100 via the waste water pipe. The end cap 100 includes a base flange 110 and a curved arch shaped end flange 112 for engaging a leaching chamber. The buttress portion 108 includes three large spaced apart buttresses 114 , 116 , 118 and two small buttresses 120 , 122 , wherein the small buttresses 120 , 122 are located intermediate the large buttresses 114 , 116 , 118 such that small buttress 120 is located between large buttress 114 and large buttress 116 and small buttress 122 is located between large buttress 116 and large buttress 118 . It should be appreciated that each buttress has at least one saddle portion 124 for supporting a pipe which may be inserted into the opening 106 which is typically created by removal of a pull-tab seal 126 .
[0019] Referring to FIG. 2 and FIG. 3 , a first embodiment of a slash plate 200 , in accordance with the present invention, is shown and includes a base panel 204 , opposing side upright portions 206 and a baffle portion 208 , wherein the base panel 204 includes one or more tab portions 210 and wherein the side upright portions 206 include semi-circular cutouts 212 . Referring to FIG. 4 , the slash plate 200 is shown associated with an end cap 100 to be closely mated with the base of the end cap 100 , wherein the base panel 204 is disposed to be parallel with and at approximately the same elevation as the base flange 110 . As shown, the tab portions 210 of flash plate 200 are configured to fit and substantially spans (i.e. to at least partially cover the soil that underlies the end cap 100 ) the interior space within the base flange portion 110 of the end cap 100 .
[0020] Additionally, the side upright portions 206 are disposed inside of the end cap cavity to be located adjacent the lower openings 106 in large buttress 114 and large buttress 118 . The side upright portions 206 may be configured to engage interior features of the end cap 100 and resist any longitudinal motion of the splash plate 200 in or out of the end cap 100 along the x-axis (as shown in FIG. 1 ), i.e. longitudinally with leaching chamber, wherein the semi-circular cutouts 212 provide clearance for any pipe that may be inserted into the opening 106 of the end cap 100 . The side upright portions 206 may also engage the outer edges of the baffle portion 208 to help prevent the baffle portion 208 from falling inwardly into the interior of the end cap 100 and onto the top of the base panel 204 .
[0021] Additionally, the baffle portion 208 , which may include a plurality of integrated perforations 214 , extends perpendicularly upright along the edge of the base panel 204 such that the baffle portion 208 nominally runs vertically and parallel to the plane of the end flange 112 of the end cap 100 , wherein the baffle portion 208 is inset from the plane of the end of end cap 100 . The opposing ends of the baffle portion 208 may be configured to engage recesses within the interior portion of the end flange 112 of the end cap 100 . This allows the baffle portion 208 to remain upright against the force of water flowing from the cavity of the end cap 100 toward the attached leaching chamber. Moreover, the engagement of the baffle portion 208 with the opposing sides of the end cap 100 helps to restrain the baffle portion 208 and the whole splash plate 200 from moving sideways along the y-axis (as shown in FIG. 1 ), i.e. in a left-right fashion within the end cap 100 .
[0022] It should be appreciated that the tab portion 210 may extend outwardly more than shown to at least partially underlie the curved outer edge of the base flange portion 110 to keep the edge of splash plate 200 from lifting. Optionally, an indicator tab 216 , shown in phantom in FIG. 4 , may be provided as an integral extension of the base panel 204 and may be configured to extend beyond the outer edge of the end cap base flange portion 110 to be visible from outside of the chamber. Not only would the indicator tab 216 substantially act as suggested for the tab portion 210 , but it would also function as a visual indicator to an inspector that the splash plate 200 has been installed. Alternatively, all or part of the base panel 204 may extend beyond the end of the flange 110 to provide the desired indicator for the plate presence, in substation of the indicator tab 216 . Moreover, while the upstream end of the splash plate 200 is curved to fit the interior bottom of the end cap 100 or chamber, it may be shaped in various other configurations. For instance, the end may be bigger than the interior so that it underlies all or a part of the flange 110 .
[0023] Referring to FIG. 5 , a splash plate 200 associated with an end cap 100 is shown having a waste water pipe 128 (shown in phantom) disposed within the opening 106 of large buttress 116 to introduce or dump waste water into the cavity of the end cap 100 , wherein the waste water pipe 128 is resting on the saddle portion 124 . FIG. 5 also shows a phantom stream 218 of waste water flowing from the waste water pipe 128 onto the base panel 204 of the splash plate 200 . It should be appreciated that water falling from the waste water pipe 128 onto the splash plate 200 then flows in the lengthwise direction, i.e. along the x-axis (as shown in FIG. 5 ), along the surface of the base panel 204 and through the plurality of integrated perforations 214 of the baffle portion 208 depending on the volume.
[0024] In an alternate embodiment, the baffle portion 208 may be solid (i.e. lack integrated perforations 214 ) and as such, water deposited onto the base panel 204 may flow around the edges of the baffle portion 208 , or it may accumulate and flow over the top edge of the baffle portion 208 . In both instances, the baffle portion 208 may inhibit the lengthwise flow of water. Thus, it should be appreciated that any accumulation of water on the base panel 204 further serves to mitigate erosion of the soil, by providing a water cushion that absorbs the energy of the dropping water. Furthermore, in FIG. 5 , to illustrate how the splash plate 200 is effective no matter what buttress is used to introduce waste water into the end cap 100 , an additional waste water pipe 220 is also shown in phantom as being disposed in the upper opening 106 of and as resting on the saddle portion 124 of large buttress 114 .
[0025] Referring to FIG. 6 and FIG. 7 , a second embodiment of a slash plate 300 , in accordance with the present invention, is shown and is similar to the splash plate 200 of FIG. 1 . The splash plate 300 includes a base panel 304 , opposing side upright portions 306 and a baffle portion 308 , wherein the base panel 304 includes one or more tab portions 310 and wherein the side upright portions 306 include semi-circular cutouts 312 . The splash plate 200 of the first embodiment differs from the splash plate of 300 of the second embodiment in that splash plate 300 includes a plurality of integrated perforations or holes 314 located in the base panel 304 . This is because in certain situations the holes 314 help to better ensure that water flowing into the end cap 100 and onto the splash plate 300 can escape through the soil which underlies the interior of the end cap 100 .
[0026] In accordance with the present invention, the baffle portion 208 , 308 should sufficient height to impede the flow of water which may cause erosion, but not so high that it creates a dam having a resultant water fall affect which itself may cause erosion of the soil downstream and/or under the splash plate. For example, one such embodiment might include a baffle 208 , 308 that is between about 0.5 inches high and about 5 inches high. Furthermore, while the baffle portion 208 , 308 is shown herein as being a vertical portion, the baffle portion 208 , 308 may be sloped or may be non-planar. For example, the end of base panel 204 , 304 and the baffle portion 208 , 308 may run along a zig-zag path from one side of the chamber to the other and/or the baffle portion 208 , 308 may be corrugated.
[0027] The holes 214 , 314 may have various sizes, shapes and patterns that differ from the holes 214 , 314 shown in splash plate 100 , 200 , the holes 214 , 314 should be sufficiently small and spaced apart to avoid soil erosion and to achieve the purposes of the invention. One advantage of the holes is that they may enable metering of the water flow when the flow is moderate, rather than forcing all of the flow to run over the top of the baffle portion 208 , 308 . According to the soil type it may be acceptable to have even greater open area than suggested by the pictures here, to the point that the base panel 204 , 304 may be screen or grid like. Furthermore, it is contemplated that the holes 214 , 314 may also be located strategically within the splash plate 200 , 300 to direct the water to desired flow paths.
[0028] Still other embodiments that are considered within the scope of the invention might include a splash plate 200 , 300 having side upright portions 206 , 306 having different shapes and sizes or a splash plate 200 , 300 having no side upright portions 206 , 306 at all. One embodiment would be a splash plate 200 , 300 configured to interact with the end cap 100 to prevent movement within the end cap cavity. For example, the splash plate 200 , 300 may include laterally extending members, such as arms or pins, configured to interact with the end cap 100 . Another example would be a splash plate 200 , 300 with a base panel 204 , 304 sized such that a portion of the base panel 204 , 304 underlies the base flange 110 . The splash plate 200 , 300 may also be fastened to the end cap 100 via a fastening device, such as a clip, tab, screw, pin, snap, Velcro and/or adhesive. Another embodiment may be a splash plate 200 , 300 having a base panel 204 , 304 and/or baffle portion 208 , 308 configured to interact with the soil below/around the splash plate 200 , 300 , such as by protrusions that dig into the soil to prevent movement.
[0029] Another embodiment may include side upright portions 206 , 306 that don't have circular cutouts 212 , 312 , but rather have a top portion which is square or some other shape. This would be especially appropriate for end caps 100 that only accommodate a pipe entering along the x-axis. In another embodiment, the side upright portions 206 , 306 may have a width or x-axis dimension that is smaller than the x-axis dimension of the base panel 204 , 304 . In still another example, the side upright portions 206 , 306 may comprise one or more foldable portions, such as two spaced apart segments.
[0030] In still yet another embodiment, the side upright portions 206 , 306 may be configured as separate pieces as opposed to integral pieces. For instance, the side upright portions 206 , 306 may be L-shaped pieces which have a base that lies in the plane of the base panel 204 , 304 to which they may be mechanically associated. In still yet another embodiment, side upright portions 206 , 306 may be positionably adjustable in the x-axis, y-axis and/or z-axis direction and/or sizably adjustable in the x-axis, y-axis and/or z-axis direction. In still yet another embodiment, side upright portions 206 , 306 may be curved or otherwise shaped to interact with the end cap 100 .
[0031] Additionally, it is contemplated that splash plate 200 , 300 may be made by various methods, including injection molding. For example, in one approach splash plate 200 , 300 may be made from a flat sheet (see FIG. 3 and FIG. 7 ) and folded to the above-described configuration(s) in the field at the point and time of installation. This provides an economical means of manufacture and shipment. One typical sheet material might be the commercial material called flutted or corrugated high density polyethylene profile board, of about 3 mm thickness and a weight of about 120 pounds per 1000 square feet; for instance, such as that made of Petrothene LR5900-00 resin and commercially available from Diversi-Plast Co., Minneapolis, Minn. Referring to FIG. 3 and FIG. 7 , splash plate 200 , 300 is shown in a flattened configuration, where to convert the flattened configuration of the splash plate 200 , 300 into the folded shape, the flattened material may be bent along the lines labeled F 1 and F 2 . It is contemplated that baffle portion 208 , 308 and/or the side upright portions 206 , 306 of splash plate 200 , 300 may not be present and as such, splash plate 200 , 300 may be a substantially flat plate having all or some of the features disclosed herein, such as an adjustable size. As such, these portions of the splash plate 200 , 300 may be left unfolded. Alternatively, the splash plate 200 , 300 may include only one foldable portion. For instance, the baffle portion 208 , 308 may be fixed while the side upright portions 206 , 306 may be foldable or vice versa.
[0032] Furthermore, the splash plate 200 , 300 (and any portion thereof) may be adjustable in the x-axis, y-axis and/or z-axis. For example, the base panel 204 , 304 may include a plurality of plates that slidably adjust in the x-axis direction to make the base panel 204 , 304 longer or shorter and/or in the y-axis direction to make the base panel 204 , 304 wider or thinner. Moreover the base panel 204 , 304 may be adjustable in the z-axis direction via extendable legs to increase the height of the base panel 204 , 304 such that base panel 204 , 304 lies in a plane above the plane of the base flange 110 . Also, the baffle portion 208 , 308 may include a plurality of plates that slidably adjust in the y-axis direction to make the baffle portion 208 , 308 wider or thinner and/or in the z-axis direction to make the baffle portion 208 , 308 taller or shorter. Similarly, the side upright portions 206 , 306 may include a plurality of plates that slidably adjust in the x-axis direction to make the side upright portions 206 , 306 wider or thinner and/or in the z-axis direction to make the side upright portions 206 , 306 taller or shorter.
[0033] It should be appreciated that end caps having other shapes than that described herein may be used with the present invention. Additionally, the present invention may be used with various types of chambers, such as those which have integrally closed ends, i.e., when the chamber has an end wall, such as that shown in U.S. Pat. No. 5,087,151 to DiTuillo. It should be further appreciated that only certain embodiments of the invention have been illustrated and that there may be other variations within the spirit and scope of the invention. For example, a splash plate 200 , 300 may omit baffle portion 208 , 308 and may only have side upright portions 206 , 306 which lock into place so that they provide the means for resisting both lengthwise x-axis and sideways y-axis motion, when installed.
[0034] While the invention has been described with reference to an exemplary embodiment, it should be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims. Moreover, unless specifically stated any use of the terms first, second, etc. do not denote any order or importance, but rather the terms first, second, etc. are used to distinguish one element from another.
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A splash plate for use with an end cap or end portion of a chamber is provided, wherein the end cap or end portion defines an end cavity having an open end cavity bottom and includes an opening for containing a waste water pipe that introduces waste water into the end cavity. The splash plate includes a base panel for covering the end cavity bottom such that waste water introduced into the end cavity contacts at least a portion of said base panel and a means for positionably securing the splash plate relative to the end cap or end portion.
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FIELD OF THE INVENTION
The invention relates to a device for applying a working power to a workpiece in order to manufacture or process the workpiece.
PRIOR ART
Devices are well-known from the prior art that comprise a piston-cylinder unit with a working cylinder and a working piston. The working piston divides the working cylinder into an actuation chamber and a return chamber. It is known that both the actuation chamber and the return chamber may be supplied with a hydraulic medium. The working power is transmitted to the workpiece through co-operation between the working piston and a force transmission device.
The European patent EP 066 11 25 describes a device for crack splitting connecting rods. A device of this type comprises, among other things, an actuating device for applying a spreading force onto the spreading wedge and thus onto the workpiece (connecting rod) by means of a hydraulic piston-cylinder unit. In addition, the actuating device includes a accumulator and a control valve arranged between the accumulator and the piston-cylinder unit, by means of which control valve, hydraulic medium stored in the accumulator under pressure may be fed suddenly into the piston-cylinder unit. In order to transmit a working power to the workpiece (connecting rod), the hydraulic medium is fed into the actuation chamber and simultaneously displaces the hydraulic medium in the return chamber. In order to return the device into its starting position, this procedure is reversed, i.e. hydraulic medium is fed into the return chamber and simultaneously the hydraulic medium is displaced from the actuation chamber.
It is known that the quality of crack splitting results, when crack splitting connecting rods, depends, among other things, upon the speed of the crack splitting procedure. For this reason, it has already been proposed in the aforementioned method and device that the control valve be designed as a cartridge valve and that the hydraulic medium be pressurized in an accumulator before feeding into the actuating chamber of the piston cylinder unit.
A further device for crack splitting connecting rods using a force or energy store is disclosed in DE 196 24 385 A1.
DESCRIPTION OF THE INVENTION
It is an object of the invention further to develop a device of the type described above such that given the simplest possible technical construction, the fastest possible transmission of working power onto a workpiece can be realised.
This object is fulfilled by a device having a working cylinder, a working piston, an actuation chamber that can be supplied with a hydraulic medium and situated on one side of the piston, a return chamber that can be supplied with a gaseous medium and situated on the opposite side of the piston, and a force transmission device which cooperates with the working piston.
The invention is based on the idea that the hydraulic medium usual in the prior art, which can be fed into the return chamber, can be replaced by a gaseous medium. The use of a gaseous medium for feeding into the return chamber offers the advantage that the resistance on displacement of the medium from the return chamber during the force transmission procedure may be reduced. This has the advantage that a yet more sudden operating method, and therefore an even more effective transmission of the working power to a workpiece, may be achieved.
Advantageous embodiments are indicated in claims 2 to 6 .
An accumulator communicates with the actuation chamber such that the hydraulic medium able to be supplied to the actuation chamber may be stored under pressure in the accumulator. This embodiment has the advantage that the working method of the device is designed to be rapid such that the most sudden possible operation may be achieved. An accumulator can be used which includes a high pressure container whose interior is divided into two chambers by a separation membrane, the lower chamber being filled with hydraulic medium and the upper chamber being filled with a compressed gas, preferably nitrogen.
According to an advantageous embodiment, arranged between the accumulator and the actuation chamber is a control valve, whereby the hydraulic medium stored under pressure in the accumulator may be fed suddenly into the actuation chamber via the control valve. A control valve of this type may be designed in any desired manner. It is essential only that the control valve is conceived such that within a short time-span, i.e. suddenly, a relatively large flow cross-section is available for the hydraulic medium, in order that the hydraulic medium stored in the accumulator may be fed as suddenly as possible into the actuation chamber. It is therefore advantageous if a two-way built-in valve is used as the control valve. Valves of this type are often known in this specialist field as cartridge valves.
According to a preferred embodiment, the workpiece is a connecting rod and the force transmission device is designed such that the connecting rod may be crack split. This has the advantage that, given the simplest possible technical construction, the most rapid crack splitting procedure may be realised. Furthermore, by this operational method, during the crack splitting procedure, a relatively slight plastic deformation of the connecting rod material in the region of the fracture plane is ensured, which approaches very closely to a so-called brittle fracture.
According to a further embodiment, the force transmission device comprises a locally fixed spreading jaw, a movable spreading jaw and a spreading device in the form of a spreading wedge for pushing apart the spreading jaws.
Advantageously, the return chamber additionally comprises a discharge device, so that the gaseous medium may be suddenly displaced from the return chamber. A discharge device of this type may, for instance, be designed as a discharge valve with a large control cross-section, so that the smallest possible back-pressure acts, on the side of the return chamber, against the hydraulic medium fed under pressure into the actuation chamber. It is advantageous in this regard if the control is designed such that the discharge device is already opened when the hydraulic medium under pressure is fed into the actuation chamber.
The invention will now be described, using examples, by reference to the attached drawings, in which:
FIG. 1 shows, schematically, a first example embodiment of a device according to the invention in a simplified overall view;
FIG. 2 shows, on an enlarged scale, a partially sectional view of a part of the example embodiment of FIG. 1 ;
FIG. 3 shows, schematically, a hydraulic layout such as that on which the first example embodiment of the device according to the invention is based.
WAYS TO CARRY OUT THE INVENTION
The first example embodiment shown in FIG. 1 of a device 1 according to the invention is built upon a stand lower portion 6 , as used in transfer lines. Placed on the stand lower portion 6 is a frame-like stand upper portion 6 a , which supports a guide arrangement 8 in the form of a vertical straight-line guiding means. A movable frame 14 is mounted on the straight-line guiding means by means of guide straps 10 and 11 , said movable frame being capable of being raised and lowered via a lifting device 7 fixed to the stand upper portion 6 a . The movable frame 14 also carries a force transmission device 5 which bears a locally fixed (i.e. directly attached to the movable frame 14 ) spreading jaw 3 and a movable spreading jaw 4 . Furthermore, this force transmission device 5 has a spreading wedge 55 shown in FIG. 2 .
The arrangement is such that the locally fixed and the movable spreading jaws of the spreading device 5 can be lowered from above via the lifting device 7 and the movable frame 14 into the large eye of a connecting rod 2 , comprising the cap and the rod, arranged in a holder on the stand upper portion, and can be pulled out of it again.
The exact construction of the force transmission device is revealed in FIG. 2 . As is evident from FIG. 2 , the locally fixed spreading jaw 3 is attached via fixing screws 12 to a fixing socket 13 of the movable frame 14 . The movable spreading jaw 4 is attached via fixing screws 12 ′ to a bearing section 21 , which is attached via a parallel guide rod arrangement 16 via fixing screws 20 to a holder section 17 representing part of the movable frame 14 . Arranged between the locally fixed spreading jaw 3 and the movable spreading jaw 4 is the spreading wedge 55 , which is linked to a push rod 19 which cooperates with the working piston 9 . The remainder of the construction of the first example embodiment of the device according to the invention, as illustrated in FIG. 2 , is described in the German utility model 92 10 197, to the disclosed content of which reference is here expressly made.
The piston cylinder unit 61 , shown in FIG. 1 , includes a piston 9 linked via a push rod 19 to a spreading wedge 55 . Arranged between the accumulator 60 and the piston cylinder unit 61 are a safety device 62 and a control valve 63 . The safety device 62 and the control valve 63 are mutually connected, and connected in relation to the accumulator 60 and to the piston cylinder unit 61 , with the shortest possible connecting lines 64 , 65 and 66 with low hydraulic resistance.
The safety device 62 is a commercially available unit having a shut-off valve and a pressure-relief valve.
The hydraulic layout represented in FIG. 3 , which is based on the first example embodiment, shows a piston cylinder unit 61 with a piston 9 which divides the piston cylinder unit 61 into an actuation chamber 85 and a return chamber 86 . The hydraulic layout also shows the accumulator 60 , which communicates with the safety device 62 , which in known manner comprises a shut-off valve and a pressure-relief valve.
Connected to the safety device 62 via a line 65 is the control valve 63 , which itself communicates with the actuation chamber 85 via the line 66 .
As is apparent from FIG. 3 , the arrangement also comprises a main pump 67 with which a hydraulic medium may be fed into the accumulator 60 for building up an accumulator power via the line 65 and the safety device 62 .
The arrangement also comprises a directional valve 82 with which the control valve 63 can be controlled.
Furthermore, the hydraulic layout shows a compressed air line 90 , which is linked by the line 91 via a directional valve 88 and a non-return valve 89 to the return chamber 86 . Furthermore, between the directional valve 88 and the return chamber 86 , a discharge device 87 is provided.
The procedure is as follows: initially, the accumulator 60 is brought to its operating pressure by the main pump 67 . Then, the directional valve 82 opens the control valve 63 . Before or simultaneously with this procedure, the discharge device 87 is opened. Since the control valve 63 is designed such that it opens a relatively large flow cross-section within a very short time, the hydraulic medium stored in the accumulator 60 can flow suddenly via lines 64 , 65 and 66 into the actuation chamber 85 of the piston cylinder unit 61 and thus suddenly transmit a force to a first side of the piston 9 , which in turn cooperates with the force transmission device 5 . Since the discharge device 87 is opened, this movement of the piston 9 encounters no noteworthy resistance, so that the force released can be transmitted directly and suddenly via the force transmission device.
Once the force transmission procedure is over, the directional valve 82 opens a discharge device of the actuation chamber, and simultaneously the directional valve 88 opens the connection of the return chamber 86 to a compressed air line 90 . The air fed in under pressure transmits a force onto a second side of the piston 9 . By this means, the piston 9 is returned to its starting position and the force transmission procedure to the workpiece may be carried out again.
By this means, the force transmission procedure takes place at a fast pace such that an operational method is assured which comes very close to a device operating with a striking weight. Therefore, with devices of the type according to the invention, a high quality force transmission result is achieved with relatively little technical effort.
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The invention relates to a device for applying a working force to a workpiece, using a working cylinder. The device includes a working piston, an actuation chamber that can be supplied with a hydraulic medium, a recirculation chamber that can be supplied with a gaseous medium and a force transmission device that co-operates with the working piston. This allows a transmission or an application of the working force to a workpiece that is as rapid as possible with a technical construction that is as simple as possible.
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CROSS-REFERENCE TO RELATED APPLICATION
The present application is a U.S. nonprovisional patent application of, and claims priority under 35 U.S.C. §119(e) to, U.S. provisional patent application Ser. No. 61/729,319 to Serguei Y. Semenov, filed Nov. 21, 2012 and entitled “ELECTROMAGNETIC TOMOGRAPHY SOLUTIONS FOR SCANNING HEAD,” which '319 application is expressly incorporated by reference herein in its entirety. Additionally, each of the following patents, patent applications and patent application publications is incorporated by reference herein in its entirety:
(a) U.S. Pat. No. 7,239,731 to Semenov et al., issued Jul. 3, 2007 and entitled “SYSTEM AND METHOD FOR NON-DESTRUCTIVE FUNCTIONAL IMAGING AND MAPPING OF ELECTRICAL EXCITATION OF BIOLOGICAL TISSUES USING ELECTROMAGNETIC FIELD TOMOGRAPHY AND SPECTROSCOPY,” which is intended, at least, to provide background and technical information with regard to the systems and environments of the inventions of the current patent application; (b) U.S. Patent Application Publication No. 2012/0010493 A1, which was published Jan. 12, 2012 based on U.S. patent application Ser. No. 13/173,078 to Semenov, filed Jun. 30, 2011 and entitled “SYSTEMS AND METHODS OF 4D ELECTROMAGNETIC TOMOGRAPHIC (EMT) DIFFERENTIAL (DYNAMIC) FUSED IMAGING,” which is intended, at least, to provide explanation of the use of “4D” technology in EMT systems, including with regard to inventions of the current patent application; and (c) U.S. Patent Application Publication No. 2014/0276012, which was published Sep. 18, 2014 based on U.S. patent application Ser. No. 13/894,395 to Semenov, filed May 14, 2013 and entitled “WEARABLE/MAN-PORTABLE ELECTROMAGNETIC TOMOGRAPHIC IMAGING,” which is intended, at least, to explain wearable and/or man-portable components of an electromagnetic tomographic imaging system.
COPYRIGHT STATEMENT
All of the material in this patent document is subject to copyright protection under the copyright laws of the United States and other countries. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in official governmental records but, otherwise, all other copyright rights whatsoever are reserved.
BACKGROUND OF THE PRESENT INVENTION
1. Field of the Present Invention
The present invention relates generally to electromagnetic tomography, and, in particular but not exclusively, to electromagnetic tomography solutions for use with the heads of humans and other animals.
2. Background
Stroke is the 2nd leading cause of death after ischeamic heart diseases, and is responsible for 4.4 million deaths (9 percent of all deaths) each year. According to American Heart Association/Stroke Association, every 40 seconds someone in America has a stroke. Every 3 minutes, someone dies of one. Stroke kills more than 137,000 Americans a year. About 795,000 Americans each year suffer a new or recurrent stroke. In Europe there are approximately 1.1 million deaths each year; in the EU there are approximately 460,000 deaths each year caused by stroke disease.
Stroke is a leading cause of serious, long-term disabilities worldwide, causing significant economic impact. The Potential Years of Life Lost (PYLL) calculated by OECD shows a significant number, which should be preventable.
Acute ischemic strokes account for about 85% of all strokes; each begins with a blood clot (thrombus) forming in the circulatory system at a site distant from the brain. The clot breaks away from this distant site forming an embolus which then travels through the circulatory system; on reaching the brain, the embolus lodges in the small vessels, interrupting blood flow to a portion of brain tissue. With this reduction in blood flow, tissue damage quickly ensues. Clinical management of stroke has been enhanced by the use of thrombolytics (clot busters) combined with the application of brain imaging techniques that reveal the pathophysiological changes in brain tissue that result from the stroke. In particular, the clinical decision to use a thrombolytic must be made within 3 hours of the onset of symptoms and requires a firm diagnosis of an ischemic stroke. This clinical decision currently relies on imaging methods such as computed tomography (CT) and magnetic resonance imaging (MRI) to reliably determine ischemic perfusion changes. Subsequent management of the stroke is enhanced by imaging the extent of the area of brain tissue with compromised blood flow. Current clinical imaging methods, including CT, positron emission tomography (PET) and MRI each offer useful information on tissue properties related to perfusion, ischemia and infarction.
While each of these methods has its own advantages, none currently offers a rapid or cost effective imaging solution that can be made widely available at the “bedside” in the emergency department or to first response paramedical services. Electromagnetic tomography (EMT), on the other hand, is a relatively recent imaging modality with great potential for biomedical applications, including a non-invasive assessment of functional and pathological conditions of biological tissues. Using EMT, biological tissues are differentiated and, consequentially, can be imaged based on the differences in tissue dielectric properties. The dependence of tissue dielectric properties from its various functional and pathological conditions, such as blood and oxygen contents, ischemia and infarction malignancies has been demonstrated.
Two-dimensional (2D), three-dimensional (3D) and even “four-dimensional” (4D) EMT systems and methods of image reconstruction have been developed over the last decade or more. Feasibility of the technology for various biomedical applications has been demonstrated, for example, for cardiac imaging and extremities imaging.
As in any biomedical imaging, the classical EMT imaging scenario consists of cycles of measurements of complex signals, as scattered by a biologic object under study, obtained from a plurality of transmitters located at various points around the object and measured on a plurality of receivers located at various points around the object. This is illustrated in FIG. 1 . As recounted elsewhere herein, the measured matrix of scattered EM signals may then be used in image reconstruction methods in order to reconstruct 3D distribution of dielectric properties of the object, i.e., to construct a 3D image of the object.
Generally, it is very important for image reconstruction to precisely describe a distribution of EM field with an imaging domain 21 . The distribution of EM field with an imaging chamber is a very complex phenomenon, even when there is no object of interest inside.
FIG. 2 is a schematic view of a prior art EM field tomographic spectroscopic system 10 , and FIG. 3 is a schematic diagram illustrating the operation of the system of FIG. 2 in a two-dimensional context. Such a system 10 could carry out functional imaging of biological tissues and could also be used for a non-invasive mapping of electrical excitation of biological tissues 19 using a sensitive (contrast) material (solution or nanoparticles) injected into the biological tissue 19 or carried in the circulation system, characterized by having dielectric properties that are a function of electrical field, generated by biological excited tissue 19 . As illustrated in FIG. 2 , the system 10 included a working or imaging chamber 12 , a plurality of “EM field source-detector” clusters 26 , an equal number of intermediate frequency (“IF”) detector clusters 28 , and a control system (not shown). Although only two EM field source-detector clusters 26 and two IF detector clusters 28 are shown, a much larger number of each are actually used.
The imaging chamber 12 is a watertight vessel of sufficient size to accommodate a human body or one or more parts of a human body together with a matching liquid. The imaging chamber 12 and its EM field clusters 26 , as well as the IF detector clusters 28 , have sometimes been mounted on carts in order to permit the respective components to be moved if necessary, and the carts may then be locked in place to provide stability.
Oversimplified, the system 10 operates as follows. An object of interest (e.g., biological tissue) is placed in the imaging domain 21 . The transmitting hardware generates electromagnetic (EM) radiation and directs it to one of the antennas. This antenna transmits electromagnetic waves into imaging domain 21 , and all of the other antennas receive electromagnetic waves that have passed through some portion of the imaging domain 21 . The receiving hardware detects the resulting signal(s), and then the same cycle is repeated for the next antenna and the next one until all antennas have served as a transmitter. The end result is a matrix of complex data which is transmitted to one or more computers in the control system that process the data to produce an image of the object 19 in the imaging domain 21 . An algorithm called an “inversion” algorithm is utilized in this process.
Electromagnetic tomography uses non-ionizing electromagnetic radiation to differentiate between human tissues. Using a compact antenna design, it creates a low power EM field (less than used in cellular phones), which interacts with the biological object and is then measured by sensors. Special imaging algorithms are then used to inverse a “data tensor” and reconstruct a 3D distribution of dielectric properties within a biological subject inside the EM field—i.e. to obtain a so-called “image tensor” or, simply, an image of the object. These imaging algorithms are in very general terms similar to the ones used in classical imaging methods (such as back-projection method used in Computed Tomography (CT)). However, the wave nature of propagation of EM waves needs to be accounted for in imaging algorithms, siginificantly complicating them. In addition, EMT imaging of the brain presents a significant challenge, as the brain is an object of interest that is located inside a high dielectric contrast shield, comprising the skull (with low dielectric contrast (∈˜10-15) and cerebral spinal fluid (with high ∈˜55-60)).
The images are possible due to the contrast in dielectric properties of various tissues. The contrasts in dielectric properties can also be mapped between normal tissues and tissues under different functional or pathological conditions (functional contrasts). Examples include: malignancies in breast, liver and lung; tissue blood content/flow; hypoxia; ischemia; infarction; compartmental injury; stroke; and brain trauma.
Unfortunately, existing EMT solutions are not well-suited for certain applications. In this regard, FIGS. 4 and 5 are schematic illustrations of two three-dimensional settings for the system of FIG. 2 . As evident therefrom, conventional EMT imaging chambers are oriented vertically so as to hold the matching liquid. Such an arrangement makes it very difficult to use the technology to image a human head because of the inconvenience of positioning a patient's head in the imaging chamber. This is particularly problematic in the emergency setting, where a patient may not be capable of positioning himself in an arrangement that allows him to insert his head into the imaging chamber. As a result, current implementations of EMT technology are not very suitable for use in diagnosing or treating stroke. Thus, a need exists for a safe, portable and cost-effective supplement to current imaging modalities for acute and chronic assessment of cerebral vascular diseases, including stroke. In particular, a need exists for the use of EMTensor technology in a mobile setting, such as in an ambulance or helicopter, and continual, safe and cost effective monitoring of an efficacy of treatment in ICUs and other medical facilities.
SUMMARY OF THE PRESENT INVENTION
Broadly defined, the present invention according to one aspect is an electromagnetic tomography (EMT) system for imaging a human head, as shown and described.
Broadly defined, the present invention according to another aspect is an electromagnetic tomography (EMT) system for imaging a human head, including: an integrated scanning apparatus; and a hub computer system.
In a feature of this aspect, the integrated scanning apparatus includes an imaging chamber. In a further feature, the imaging chamber is vertically oriented such that a human head may be inserted horizontally into the imaging chamber.
In another feature of this aspect, the integrated scanning apparatus houses a plurality of rings of antennas. In further features, each ring of the plurality of rings is vertically oriented; the rings of the plurality of rings are concentric with each other; and/or the rings include a first set of rings of antennas that are transmitting and receiving antennas, and a second set of rings of antennas that are receiving antennas only.
In further features pertaining to the first and second sets of rings, the second set of rings is divided into two subsets, and the first set of rings of antennas is located between the two subsets; the first subset of rings includes one ring; and/or the second subset of rings includes four rings.
In a further feature pertaining to the rings, each ring includes 32 antennas.
In another feature of this aspect, the integrated scanning apparatus is man-portable.
In another feature of this aspect, the integrated scanning apparatus and hub computer system are transportable. In a further feature, the integrated scanning apparatus and hub computer system are mobile.
Broadly defined, the present invention according to another aspect is an integrated scanning apparatus for imaging a human head in an electromagnetic tomography (EMT) system, as shown and described.
Broadly defined, the present invention according to another aspect is an integrated scanning apparatus for imaging a human head in an electromagnetic tomography (EMT) system, including: a housing defining a vertically oriented imaging chamber in which a human head may be inserted horizontally; and an array of antennas.
In a feature of this aspect, the integrated scanning apparatus is transportable. In a further feature, the integrated scanning apparatus is mobile. In a still further feature, the integrated scanning apparatus is man-portable.
In another feature of this aspect, the array of antennas is arranged in a plurality of rings of antennas. In further features, the rings of the plurality of rings are concentric with each other; the rings include a first set of rings of antennas that are transmitting and receiving antennas, and a second set of rings of antennas that are receiving antennas only; and/or each ring includes 32 antennas.
In further features pertaining to the first and second sets of rings, the second set of rings is divided into two subsets, and the first set of rings of antennas is located between the two subsets; the first subset of rings includes one ring; and/or the second subset of rings includes four rings.
Broadly defined, the present invention according to another aspect is a wearable scanning apparatus for imaging a human head in an electromagnetic tomography (EMT) system, as shown and described.
Broadly defined, the present invention according to another aspect is a method of treating a stroke patient using an electromagnetic tomography (EMT) system, as shown and described.
Broadly defined, the present invention according to another aspect is a method of treating a stroke patient using an electromagnetic tomography (EMT) system, including: in response to an emergency report and request from or on behalf of stroke patient, providing an ambulance equipped with a scanning apparatus for imaging a human head in an electromagnetic tomography (EMT) system; placing the scanning apparatus on or around the stroke patient's head; carrying out an EMT scanning process; providing data from the EMT scanning process to a hub computer system; producing EMT image results based on the provided data; and providing the EMT image results to a medical practitioner at a treatment center for use in diagnosing or treating the stroke patient upon the patient's arrival at the treatment center.
Broadly defined, the present invention according to another aspect is an image chamber unit for gathering measurement data pertaining to a human head in an electromagnetic tomography (EMT) system, including: an antenna assembly at least partially defining a horizontally-oriented imaging chamber and including an array of antennas arranged around the imaging chamber, the array of antennas including at least some transmitting antennas and at least some receiving antennas, wherein the transmitting antennas transmit a low power electromagnetic field, wherein the receiving antennas receive the low power electromagnetic field after passing through a human head in the imaging chamber and provide corresponding signals to a control system so as to produce a data tensor that may be inversed to reconstruct a 3D distribution of dielectric properties within the human head and thereby to create an image of the object; and a housing, at least partially containing the antenna assembly, having a front entry opening into the imaging chamber. The head of a human patient may be inserted horizontally through the front entry opening and into the imaging chamber.
In a feature of this aspect the antenna assembly includes a plurality of antenna disks, each antenna disk including an array of antennas. Each antenna disk includes a center opening, wherein the imaging chamber is at least partially defined by the plurality of center openings. The antenna disk center openings are circular and collectively define a cylindrical portion of the imaging chamber. The antenna assembly further includes a back disk attached to a rear of the antenna disks, wherein the back disk closes and defines a rear of the horizontally-oriented imaging chamber.
In a further feature, the array of antennas on each antenna disk is arranged in a ring whose center axis is oriented horizontally. The rings include a first set of rings of antennas that are transmitting and receiving antennas, and a second set of rings of antennas that are receiving antennas only. The second set of rings is divided into two subsets, and wherein the first set of rings of antennas is located between the two subsets. The first subset of rings includes one ring. The second subset of rings includes four rings. Each ring includes 32 antennas.
In another feature of this aspect, the image chamber unit further includes a flexible membrane separating a front portion of the imaging chamber from a rear portion of the imaging chamber. The flexible membrane conforms to a portion of the shape of a human head when the human head is inserted through the front entry opening and into the front portion of the imaging chamber. The rear portion of the imaging chamber is filled with a liquid. The liquid is a matching liquid for an electromagnetic tomography operation. The matching liquid is a mixture of glycerol, water and brine. The antenna assembly further includes a back disk attached to a rear of a plurality of antenna disks, and wherein the back disk includes at least one inlet for pumping the matching liquid into the rear portion of the imaging chamber. In a further feature of this aspect the image chamber unit of, further includes a catch basin disposed adjacent the entry opening so as to receive liquid leaking from the front of the imaging chamber. The catch basin includes a drain tube. In a further feature of this aspect the image chamber further includes a sanitary protective cap disposed in front of and against the flexible membrane to provide sanitary protection for a human head when the human head is inserted into the front entry opening and against the membrane. In yet a further feature of this aspect the image chamber further includes a protective ring around the entry opening to protect the human head from injury when inserting the head through the entry opening.
Broadly defined, the present invention according to another aspect is an electromagnetic tomography (EMT) system for gathering measurement data pertaining to a human head, including: an image chamber unit including an antenna assembly at least partially defining a horizontally-oriented imaging chamber and including an array of antennas arranged around the imaging chamber, the array of antennas including at least some transmitting antennas and at least some receiving antennas, a control system that causes the transmitting antennas to transmit a low power electromagnetic field that is received by the receiving antennas after passing through a human head in the imaging chamber and produces a data tensor from resulting signals that may be inversed to reconstruct a 3D distribution of dielectric properties within the human head and thereby to create an image of the object; and a housing, at least partially containing the antenna assembly, having a front entry opening into the imaging chamber. The head of a human patient may be inserted horizontally through the front entry opening and into the imaging chamber.
In a feature of this aspect the antenna assembly includes a plurality of antenna disks, each antenna disk including an array of antennas. Each antenna disk includes a center opening, wherein the imaging chamber is at least partially defined by the plurality of center openings. The antenna disk center openings are circular and collectively define a cylindrical portion of the imaging chamber. The antenna assembly further includes a back disk attached to a rear of the antenna disks, wherein the back disk closes and defines a rear of the horizontally-oriented imaging chamber. In a feature of this aspect, the array of antennas on each antenna disk is arranged in a ring whose center axis is oriented horizontally. The rings include a first set of rings of antennas that are transmitting and receiving antennas, and a second set of rings of antennas that are receiving antennas only. The second set of rings is divided into two subsets, and wherein the first set of rings of antennas is located between the two subsets. The first subset of rings includes one ring. The second subset of rings includes four rings. Each ring includes 32 antennas.
In another feature, the image chamber unit further includes a flexible membrane separating a front portion of the imaging chamber from a rear portion of the imaging chamber. The flexible membrane conforms to a portion of the shape of a human head when the human head is inserted through the front entry opening and into the front portion of the imaging chamber. The rear portion of the imaging chamber is filled with a liquid. The liquid is a matching liquid for an electromagnetic tomography operation. The matching liquid is a mixture of glycerol, water and brine. The antenna assembly further includes a back disk attached to a rear of a plurality of antenna disks, and wherein the back disk includes at least one inlet for pumping the matching liquid into the rear portion of the imaging chamber. In a further feature of this aspect the image chamber unit of, further includes a catch basin disposed adjacent the entry opening so as to receive liquid leaking from the front of the imaging chamber. The catch basin includes a drain tube. The catch basin is attached to the image chamber unit. The catch basin is separate from, but positioned next to, the image chamber unit.
In a further feature of this aspect the image chamber further includes a sanitary protective cap disposed in front of and against the flexible membrane to provide sanitary protection for a human head when the human head is inserted into the front entry opening and against the membrane. In yet a further feature of this aspect the image chamber further includes a protective ring around the entry opening to protect the human head from injury when inserting the head through the entry opening.
In another feature, the electromagnetic tomography (EMT) system further included a patient support. The patient support includes a headrest extending therefrom so as to position and/or orient a patient's head within the imaging chamber. The image chamber unit is disposed on top of the patient support, on one end thereof, and wherein the control system is carried beneath the patient support.
In another feature, the electromagnetic tomography (EMT) system further included a hydraulic system supplying liquid to the imaging chamber. The hydraulic system includes a holding tank for the liquid and a pump. The holding tank is a first tank, wherein the hydraulic system further includes a second internal tank, and wherein the liquid flows from the first tank to the imaging chamber and from the imaging chamber to the second tank. In a further feature of this aspect an inline valve is disposed between the first tank and the imaging chamber. In a further feature of this aspect a backflow valve is disposed between the imaging chamber and the second tank. In a further feature of this aspect a check valve is disposed between the imaging chamber and the second tank in parallel with the backflow valve. In a further feature of this aspect a temperature sensor is disposed at an inlet to the imaging chamber. A heater to raise the temperature of the liquid based on the status of the temperature sensor. A liquid sensor that prevents heating if liquid is not present in the second tank. In a further feature of this aspect, the electromagnetic tomography (EMT) system includes an overflow path from the second tank. The overflow path connects the second tank back to the first tank. The pump includes a remote control. The pump is a bi-directional pump.
Broadly defined, the present invention according to another aspect is an image chamber unit for gathering measurement data pertaining to a human head in an electromagnetic tomography (EMT) system, including: an antenna assembly at least partially defining a imaging chamber and including an array of antennas arranged around the imaging chamber, the array of antennas including at least some transmitting antennas and at least some receiving antennas, wherein the transmitting antennas transmit a low power electromagnetic field, wherein the receiving antennas receive the low power electromagnetic field after passing through a human head in the imaging chamber and provide corresponding signals to a control system so as to produce a data tensor that may be inversed to reconstruct a 3D distribution of dielectric properties within the human head and thereby to create an image of the object; a housing, at least partially containing the antenna assembly, having an entry opening into the imaging chamber; a flexible membrane separating a first portion of the imaging chamber from a second portion of the imaging chamber. The head of a human patient may be inserted through the front entry opening and into the imaging chamber.
In a feature of this aspect the imaging chamber is horizontally-oriented, wherein the entry opening is a front entry opening, wherein the first portion of the imaging chamber is at a front of the imaging chamber near the front entry opening, and wherein the second portion of the imaging chamber is at a rear of the imaging chamber such that the flexible membrane separates the front portion of the imaging chamber from the rear portion of the imaging chamber. The flexible membrane conforms to a portion of the shape of a human head when the human head is inserted through the front entry opening and into the front portion of the imaging chamber. the rear portion of the imaging chamber is filled with a liquid. The liquid is a matching liquid for an electromagnetic tomography operation. The matching liquid is a mixture of glycerol, water and brine.
In a further feature the antenna assembly further includes a back disk attached to a rear of a plurality of antenna disks, and wherein the back disk includes at least one inlet for pumping the matching liquid into the rear portion of the imaging chamber.
In a further feature the image chamber unit further includes a catch basin disposed adjacent the entry opening so as to receive liquid leaking from the front of the imaging chamber. The catch basin includes a drain tube. In a further feature of this aspect the image chamber further includes a sanitary protective cap disposed in front of and against the flexible membrane to provide sanitary protection for a human head when the human head is inserted into the front entry opening and against the membrane.
In a further feature the antenna assembly includes a plurality of antenna disks, each antenna disk including an array of antennas. Each antenna disk includes a center opening, wherein the imaging chamber is at least partially defined by the plurality of center openings. The antenna disk center openings are circular and collectively define a cylindrical portion of the imaging chamber. The antenna assembly further includes a back disk attached to a rear of the antenna disks, wherein the back disk closes and defines a rear of the horizontally-oriented imaging chamber. The array of antennas on each antenna disk is arranged in a ring whose center axis is oriented horizontally The rings include a first set of rings of antennas that are transmitting and receiving antennas, and a second set of rings of antennas that are receiving antennas only. The second set of rings is divided into two subsets, and wherein the first set of rings of antennas is located between the two subsets. The first subset of rings includes one ring. The second subset of rings includes four rings. Each ring includes 32 antennas.
In a further feature the image chamber further includes a protective ring around the entry opening to protect the human head from injury when inserting the head through the entry opening.
Broadly defined, the present invention according to another aspect is a method of using an electromagnetic tomography (EMT) system to generate a data tensor for imaging a human head, including: positioning a patient on his back on a patient support; inserting the head of the patient horizontally through a front entry opening of an image chamber unit, the image chamber unit including an antenna assembly at least partially defining a horizontally-oriented imaging chamber and including an array of antennas arranged around the imaging chamber, the array of antennas including at least some transmitting antennas and at least some receiving antennas; and using a control system, causing the transmitting antennas to transmit a low power electromagnetic field that is received by the receiving antennas after passing through the patient's head in the imaging chamber and producing a data tensor from resulting signals that may be inversed to reconstruct a 3D distribution of dielectric properties within the human head and thereby to create an image of the patient's head. The image chamber unit includes a housing that at least partially contains the antenna assembly, wherein the front entry opening is in the housing, and wherein the method further includes providing a membrane, within the imaging chamber, that separates a front portion of the imaging chamber from a rear portion.
In a feature of this aspect, the method includes a step of conforming the flexible membrane to a portion of the shape of the patient's head when the head is inserted through the front entry opening and into the front portion of the imaging chamber.
In a feature of this aspect, the method further includes a step of filling the rear portion of the imaging chamber with a liquid. The liquid is a matching liquid for an electromagnetic tomography operation. The matching liquid is a mixture of glycerol, water and brine. The antenna assembly further includes a back disk attached to a rear of a plurality of antenna disks, and wherein the method further includes pumping the matching liquid into the rear portion of the imaging chamber through at least one inlet in the back disk. In a further feature of this aspect the method further includes a step of positioning a catch basin adjacent the entry opening so as to receive liquid leaking from the front of the imaging chamber. The catch basin includes a drain tube.
In a further feature the method includes a step of placing a sanitary protective cap over the patient's head so that the protective cap is disposed between the patient's head and the flexible membrane to provide sanitary protection for a human head when the human head is inserted into the front entry opening and against the membrane.
Broadly defined, the present invention according to another aspect is a method of using an electromagnetic tomography (EMT) system to generate a data tensor for imaging a human head, including: in response to an emergency report and request from or on behalf of stroke patient, providing an ambulance equipped with an image chamber unit for gathering measurement data pertaining to a human head in an electromagnetic tomography (EMT) system, the image chamber unit including: an antenna assembly at least partially defining a horizontally-oriented imaging chamber and including an array of antennas arranged around the imaging chamber, the array of antennas including at least some transmitting antennas and at least some receiving antennas, wherein the transmitting antennas transmit a low power electromagnetic field, wherein the receiving antennas receive the low power electromagnetic field after passing through a human head in the imaging chamber and provide corresponding signals to a control system so as to produce a data tensor that may be inversed to reconstruct a 3D distribution of dielectric properties within the human head and thereby to create an image of the object, and a housing, at least partially containing the antenna assembly, having a front entry opening into the imaging chamber; positioning the stroke patient on his back on a patient support; inserting the head of the patient horizontally through the front entry opening of the image chamber unit and into the imaging chamber; using a control system, causing the transmitting antennas to transmit a low power electromagnetic field that is received by the receiving antennas after passing through the patient's head in the imaging chamber and producing a data tensor from resulting signals that may be inversed to reconstruct a 3D distribution of dielectric properties within the human head and thereby to create an image of the patient's head; providing the data tensor to a hub computer system; producing EMT image results based on the provided data; and providing the EMT image results to a medical practitioner at a treatment center for use in diagnosing or treating the stroke patient upon the patient's arrival at the treatment center.
In a feature of this aspect, the method further includes providing a membrane, within the imaging chamber, that separates a front portion of the imaging chamber from a rear portion. In a further feature of this aspect, the method further includes a step of conforming the flexible membrane to a portion of the shape of the patient's head when the head is inserted through the front entry opening and into the front portion of the imaging chamber. In a further feature of this aspect, the method further includes a step of filling the rear portion of the imaging chamber with a liquid. The liquid is a matching liquid for an electromagnetic tomography operation. The matching liquid is a mixture of glycerol, water and brine. The antenna assembly further includes a back disk attached to a rear of a plurality of antenna disks, and wherein the method further includes pumping the matching liquid into the rear portion of the imaging chamber through at least one inlet in the back disk.
In a further feature the method includes the step of positioning a catch basin adjacent the entry opening so as to receive liquid leaking from the front of the imaging chamber. The catch basin includes a drain tube.
In yet a further feature the method includes the step of placing a sanitary protective cap over the patient's head so that the protective cap is disposed between the patient's head and the flexible membrane to provide sanitary protection for a human head when the human head is inserted into the front entry opening and against the membrane
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, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
Further features, embodiments, and advantages of the present invention will become apparent from the following detailed description with reference to the drawings, wherein:
FIG. 1 is a graphical illustration of the principle of electromagnetic tomography (EMT);
FIG. 2 is a schematic view of a prior art EM field tomographic spectroscopic system;
FIG. 3 is a schematic diagram illustrating the operation of the system of FIG. 1 in a two-dimensional context;
FIGS. 4 and 5 are schematic illustrations of two three-dimensional settings for the system of FIG. 2 ;
FIG. 6 is a front isometric view of an EMT system for imaging a human head in accordance with one or more preferred embodiments of the present invention;
FIG. 7 is a front plan view of the EMT system of FIG. 6 ;
FIG. 8 is a rear perspective view of the EMT system of FIG. 6 ;
FIG. 9 is a cross-sectional, partially schematic, right side view of the image chamber unit of FIG. 7 , taken along line 9 - 9 ;
FIG. 10 is a view of the image chamber unit similar to that of FIG. 9 , but shown with a patient support and a catch basin in place adjacent the unit;
FIG. 11 is a view of the image chamber unit similar to that of FIG. 10 , but shown with an upper portion of a patient's head inserted into the entry opening;
FIGS. 12 and 13 are a rear isometric view and a rear plan view, respectively, of the membrane of the image chamber unit of FIG. 6 ;
FIG. 14 is a side cross-sectional view of the membrane of FIG. 13 , taken along line 14 - 14 ;
FIG. 15 is a view of the image chamber unit similar to that of FIG. 11 , but shown with a fluid disposed within the working chamber on the opposite side of the membrane from the patient's head;
FIG. 16 is a schematic diagram of the hydraulic system of FIG. 8 ;
FIG. 17 is a left front isometric view of portions of the disk assembly of FIG. 9 ;
FIG. 18 is a schematic representation of concentric rings of antennas;
FIG. 19 is a top cross-sectional view of the disk assembly of FIG. 17 , taken along line 19 - 19 ;
FIG. 20 is a front view of one of the antenna disks of FIG. 19 ;
FIG. 21 is a top cross-sectional view of the antenna disk of FIG. 20 ;
FIG. 22 is a schematic diagram of the EMT system of FIG. 6 ;
FIG. 23 is a schematic representation of the operation of the rings of antennas around the imaging domain;
FIGS. 24A and 24B are a more detailed schematic diagram of the control system of FIG. 22 ;
FIG. 25 is a schematic diagram of one of the transmitting/receiving switch units of FIG. 22 ;
FIG. 26 is a schematic diagram of one of the receiving switch units of FIG. 22 ;
FIG. 27 is a schematic diagram of the power unit of FIG. 22 ;
FIG. 28 is a schematic block diagram of additional or alternative details of a control system for the EMT system;
FIGS. 29 and 30 are a top front perspective view and a bottom rear perspective view, respectively, of another EMT system for imaging a human head in accordance with one or more preferred embodiments of the present invention;
FIG. 31 is a top plan view of the system in use in an ambulance;
FIG. 32 is a side perspective view of a cap serving as a wearable image chamber unit in accordance with one or more preferred embodiments of the present invention; and
FIG. 33 is a pictorial illustration of a timeline for use of an EMT system, including the cap of FIG. 32 , for imaging a human head in response to the onset of stroke symptoms in a patient.
DETAILED DESCRIPTION
As a preliminary matter, it will readily be understood by one having ordinary skill in the relevant art (“Ordinary Artisan”) that the present invention has broad utility and application. Furthermore, any embodiment discussed and identified as being “preferred” is considered to be part of a best mode contemplated for carrying out the present invention. Other embodiments also may be discussed for additional illustrative purposes in providing a full and enabling disclosure of the present invention. As should be understood, any embodiment may incorporate only one or a plurality of the above-disclosed aspects of the invention and may further incorporate only one or a plurality of the above-disclosed features. Moreover, many embodiments, such as adaptations, variations, modifications, and equivalent arrangements, will be implicitly disclosed by the embodiments described herein and fall within the scope of the present invention.
Accordingly, while the present invention is described herein in detail in relation to one or more embodiments, it is to be understood that this disclosure is illustrative and exemplary of the present invention, and is made merely for the purposes of providing a full and enabling disclosure of the present invention. The detailed disclosure herein of one or more embodiments is not intended, nor is to be construed, to limit the scope of patent protection afforded the present invention, which scope is to be defined by the claims and the equivalents thereof. It is not intended that the scope of patent protection afforded the present invention be defined by reading into any claim a limitation found herein that does not explicitly appear in the claim itself.
Thus, for example, any sequence(s) and/or temporal order of steps of various processes or methods that are described herein are illustrative and not restrictive. Accordingly, it should be understood that, although steps of various processes or methods may be shown and described as being in a sequence or temporal order, the steps of any such processes or methods are not limited to being carried out in any particular sequence or order, absent an indication otherwise. Indeed, the steps in such processes or methods generally may be carried out in various different sequences and orders while still falling within the scope of the present invention. Accordingly, it is intended that the scope of patent protection afforded the present invention is to be defined by the appended claims rather than the description set forth herein.
Additionally, it is important to note that each term used herein refers to that which the Ordinary Artisan would understand such term to mean based on the contextual use of such term herein. To the extent that the meaning of a term used herein—as understood by the Ordinary Artisan based on the contextual use of such term—differs in any way from any particular dictionary definition of such term, it is intended that the meaning of the term as understood by the Ordinary Artisan should prevail.
Regarding applicability of 35 U.S.C. §112, ¶6, no claim element is intended to be read in accordance with this statutory provision unless the explicit phrase “means for” or “step for” is actually used in such claim element, whereupon this statutory provision is intended to apply in the interpretation of such claim element.
Furthermore, it is important to note that, as used herein, “a” and “an” each generally denotes “at least one,” but does not exclude a plurality unless the contextual use dictates otherwise. Thus, reference to “a picnic basket having an apple” describes “a picnic basket having at least one apple” as well as “a picnic basket having apples.” In contrast, reference to “a picnic basket having a single apple” describes “a picnic basket having only one apple.”
When used herein to join a list of items, “or” denotes “at least one of the items,” but does not exclude a plurality of items of the list. Thus, reference to “a picnic basket having cheese or crackers” describes “a picnic basket having cheese without crackers,” “a picnic basket having crackers without cheese,” and “a picnic basket having both cheese and crackers.” Finally, when used herein to join a list of items, “and” denotes “all of the items of the list.” Thus, reference to “a picnic basket having cheese and crackers” describes “a picnic basket having cheese, wherein the picnic basket further has crackers,” as well as describes “a picnic basket having crackers, wherein the picnic basket further has cheese.”
Referring now to the drawings, in which like numerals represent like components throughout the several views, one or more preferred embodiments of the present invention are next described. The following description of one or more preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.
FIG. 6 is a front isometric view of an EMT system 110 for imaging a human head 19 in accordance with one or more preferred embodiments of the present invention, FIG. 7 is a front plan view of the EMT system 110 of FIG. 6 , and FIG. 8 is a rear perspective view of the EMT system 110 of FIG. 6 . As shown therein, the system 110 includes an image chamber unit 131 , a control cabinet 135 , a hydraulic system 140 for supplying, circulating, and otherwise managing a matching fluid to the image chamber unit 131 , and a rolling carriage 132 . In at least some embodiments, the image chamber unit 131 and the control cabinet 135 are housed together in a single enclosure 134 and are supported on a rolling carriage 132 . Furthermore, in at least some embodiments, some or all of the hydraulic system 140 is supported on the rolling carriage 132 as well. However, in some embodiments, the image chamber unit 131 and control cabinet 135 are separate from each other and each may or may not be carried on its own rolling carriage. In some of these embodiments, the image chamber unit 131 and control cabinet 135 are not located in the same room. Although not illustrated in FIGS. 6-8 , the system 110 also includes a user interface computer 208 , described elsewhere herein, which may be connected to the rest of the system 110 via Ethernet or other port 136 located on the side of the control cabinet 131 .
FIG. 9 is a cross-sectional, partially schematic, right side view of the image chamber unit 131 of FIG. 7 , taken along line 9 - 9 . As shown therein, the image chamber unit 131 includes a disk assembly 126 , a membrane 133 , and fluid inlets 167 , 168 . The disk assembly 126 includes a plurality of antenna disks 170 and a back disk 183 , wherein at least the antenna disks 170 are open in their centers. The center openings of the antenna disks 170 together with the back disk 183 at least partially define a “working” chamber or “imaging” chamber 122 . In at least some embodiments, the antenna disk center openings are circular, and the circular openings thus define a cylindrical portion of the working chamber 122 (perhaps best seen in FIG. 17 ), which simplifies the operation of the tomography somewhat, but in other embodiments the center openings and working chamber 122 may take on other shapes. In at least some embodiments, the volume of the working chamber 122 is approximately 12 liters.
The center opening of the frontmost antenna disk 170 defines an entry opening 169 for receiving a patient. The entry opening 169 is preferably surrounded by a protective ring 182 (shown in FIGS. 6 and 7 ) covering the surfaces of the antenna disk 170 and other portions of the working chamber 122 . FIG. 10 is a view of the image chamber unit 131 similar to that of FIG. 9 , but with a patient support 120 and a catch basin 165 in place adjacent the unit 131 , and FIG. 11 is a view of the image chamber unit 131 similar to that of FIG. 10 but shown with an upper portion of a patient's head 19 inserted into the entry opening. For comfort and convenience, the patient may be positioned on the patient support 120 , which may be a gurney, cart, table, stretcher, or the like. In at least some embodiments of the present invention, a headrest 118 extends from the end of the patient support 120 . The headrest 118 is preferably padded and adjustable. Adjustability of the headrest 118 may be provided in one or more of the longitudinal direction (toward or away from the end of the patient support 120 ), the vertical direction (up or down relative to the patient support 120 ), and rotationally (for example, about an axis that is parallel with the end of the patient support 120 ). In the illustrated embodiment, the entry opening and the working chamber 122 are sized to correspond specifically to a human head, but it will be appreciated that other dimensions may be utilized for other body parts or to accommodate the entirety of a human body. The entry opening is substantially liquid-sealed by the membrane 133 such that the front of the working chamber 122 is separated by the membrane 133 from the rear of the chamber 122 . Fluid leaks through the front of the working chamber 122 , such as around or through the membrane 133 , may be captured in the catch basin 165 disposed in front of the unit 131 . It is contemplated that the catch basin 165 can be integral with or otherwise part of the image chamber unit 131 .
FIGS. 12 and 13 are a rear isometric view and a rear plan view, respectively, of the membrane 133 of the image chamber unit 131 of FIG. 6 , and FIG. 14 is a side cross-sectional view of the membrane 133 of FIG. 13 , taken along line 14 - 14 . The membrane 133 is preferably somewhat hat-shaped, with a center crown portion 127 extending “upward” or “inward” from an outer brim portion 128 . The brim portion 128 is shaped to be fastened to the antenna disks 170 and may include apertures 129 for this purpose. As shown in FIG. 14 , the crown portion 127 may be thinner than the brim portion 128 and is preferably flexible enough to wrap snugly around the patient's head 19 , as shown in FIG. 11 . In at least some embodiments, the membrane 133 is made of latex or similar material.
FIG. 15 is a view of the image chamber unit 131 similar to that of FIG. 11 but shown with a fluid disposed within the working chamber 122 on the opposite side of the membrane 133 from the patient's head 19 . The fluid may be supplied to or from the working chamber 122 via the inlets 167 , 168 , which may be arranged in or on the back disk 183 . The fluid itself is a “matching” fluid that is chosen for its properties so as to enhance the tomographic process. Flow and other movement of the fluid is controlled by the hydraulic system 140 .
FIG. 16 is a schematic diagram of the hydraulic system 140 of FIG. 8 . As shown therein, the hydraulic system 140 includes an external tank 141 , a bi-directional pump 142 , a valve 159 , backflow valve 160 , a check (directional) valve 161 , an inner upper tank 146 , one or more liquid sensors 147 , a lighter 148 , one or more temperature sensors 149 , 150 , and a variety of hoses, tubes, fittings, and the like, some of which are described herein. The external tank 141 holds a quantity of a matching fluid. A hose 151 connects the external tank 141 to the pump 142 , and another hose 152 connects the pump 142 to a fitting 153 on the enclosure 134 . In at least some embodiments, the pump hoses 151 , 152 are ¾″ flexible tube hoses, and the hose fitting 153 is a quick release fitting.
The pump 142 is used to supply matching fluid from the external tank 141 to the working (image) chamber of the image chamber unit 131 . The matching fluid is a solution or gel that is needed or useful inside the imaging chamber when the object 19 is being measured inside it to address electromagnetic body-matching problems. In at least some embodiments, the matching liquid is a mixture of glycerol (Ph. Eur.), water and brine. In at least some embodiments, the pump 142 is connected by cable 154 to a standard power supply, such as a 220V electrical source, which may be provided from the control cabinet 135 via an outlet 137 , preferably located on the outer surface of the enclosure 134 , and a corresponding water proof socket 155 . Direction, speed, and other control of the pump 142 may be provided by remote control 156 . One pump 142 suitable for use in at least some preferred embodiments is a Watson Marlow 620 RE IP66 pump.
Inside the image chamber unit 131 , another hose 157 is connected between the external fitting 153 and a first inlet 167 to the working chamber, and still another hose 158 is connected between a second inlet 168 to the working chamber and the inner upper tank 146 . In at least some embodiments, the hose 157 is a ¾″ flexible tube hose. An inline valve 159 may optionally be provided in the hose 157 from the pump 134 , while a backflow valve 160 and check (directional) valve 161 may be provided in the hose 158 to the inner upper tank 146 . The backflow valve 160 provides at least two functions. First, when it is closed, the pump 142 may be used to generate an under-pressure, thereby denting in the membrane 133 (as seen from outside the image chamber unit 131 ) and readying the unit 131 for a patient's head to be inserted therein. Second, when the patient's head is positioned inside the membrane 133 , opening the backflow valve 160 allows the matching fluid to flow from the reservoir 146 back to the imaging chamber, which in turn causes the patient's head to be slowly enclosed by the membrane 133 and the liquid. The check valve 161 , on the other hand, performs a safety function by avoiding the buildup of an overpressure if the backflow valve 160 is closed. The check valve 161 includes a manual control lever 181 , as shown in FIG. 6 .
The temperature sensors 149 , 150 may be used to determine the temperature of the matching fluid inside the working chamber, or in close proximity thereto. If the temperature becomes uncomfortably cool, the lamp or lighter 148 may be utilized to trigger heating of the inner upper tank 146 . Unintentional heating of an empty tank 146 may be avoided by using the liquid sensors 147 to verify that sufficient liquid is present in the tank.
An overfill path may be provided between the inner upper tank 146 and the external tank 141 so as to return any excess matching liquid to the external tank 141 . The overfill path may include an internal hose 162 , an external hose 163 , and a fitting 164 on the exterior of the enclosure 134 , wherein the internal hose 162 is connected between the inner upper tank 146 and the fitting 164 and the external hose is connected between the fitting 164 and the external tank 141 . Generally, the overfill path is only utilized if the reservoir 146 is accidentally overfilled, in which case the overfill path allows the excess liquid to return to the external tank 141 . In at least some embodiments, the overfill path hoses 162 , 163 are ¾″ flexible tube hoses, and the hose fitting 164 is a quick release fitting.
A leakage path may also be provided. The leakage path may include a catch basin 165 and a drain hose or tube 166 . The catch basin 165 may be disposed adjacent the working chamber so as to receive fluid escaping therefrom, such as during dismantling of the system 110 . In some embodiments, the drain hose 166 connects the catch basin 165 to the external tank, such as by the overflow path, while in others the drain hose 166 is routed to a waste tank (not shown) and/or is left open or unconnected.
FIG. 17 is a left front isometric view of portions of the disk assembly 126 of FIG. 9 . As shown therein, the disk assembly 126 includes a plurality of antenna disks 170 arranged concentrically such that their center openings define the interior of the working chamber 122 , as described previously. Notably, whereas traditional EMT systems have used rings of transmitters/receivers/sensors that have been oriented in a horizontal plane to define a vertical working chamber, the rings of transmitter/receivers and receivers of the present invention are each oriented vertically so as to define a horizontal working chamber. Each antenna disk 170 includes a multitude of antennas 173 arranged in a ring around the working chamber 122 . FIG. 18 is a schematic representation of these concentric rings 180 of antennas 173 . Although other numbers of disks 170 and rings 180 may be utilized, five antenna disks 170 and thus five antenna rings 180 are present in the embodiment shown in FIGS. 17 and 18 . Furthermore, although other numbers of antennas 173 may be utilized, 32 antennas 173 are present in the embodiment shown in FIGS. 17 and 18 , and thus a total of 160 antennas 173 are utilized. In one embodiment, preferred for its simplicity, the antennas 173 in the middle ring 180 are both transmitting and receiving antennas, while the antennas 173 on the other four rings 180 are receiving antennas only. In one contemplated embodiment, the rings 180 (i.e., the center openings of the antenna disks 170 ) are 285 mm in diameter. In FIG. 17 , transmitting/receiving antenna “9” on ring “C” is shown as transmitting an electromagnetic field or signal, all or some of which is received at each of various transmitting/receiving antennas on ring “C” and at each of various receiving antennas on rings “A”, “B”, “D”, and “E”. It will be appreciated, however, that any or all of the transmitting/receiving antennas on ring “C” and/or any or all of the receiving antennas on any or all of the other rings may receive the transmitted field or signal and thus may be incorporated into the tomographic process.
FIG. 19 is a top cross-sectional view of the disk assembly 126 of FIG. 17 , taken along line 19 - 19 ; FIG. 20 is a front view of one of the antenna disks 170 of FIG. 19 , and FIG. 21 is a top cross-sectional view of the antenna disk 170 of FIG. 20 . Notably, some visual detail regarding the electrical connections for the antennas has been omitted in FIG. 17 ; however, much of the omitted visual detail is shown in FIG. 20 . Each antenna disk 170 includes two mating rings 171 , 172 , the antennas 173 themselves, a corner element 174 for each antenna 173 , a cable plate 175 , and a cable assembly 176 for each antenna 173 . Each cable assembly 176 includes a cable and/or conduit with an appropriate terminator 177 , 178 on each end. Screws or other cable positioners 179 are provided to hold the cable assemblies 176 in place.
FIG. 22 is a schematic diagram of the EMT system 110 of FIG. 6 . As shown therein, the EMT system 110 includes the image chamber unit 131 (including the working chamber 122 ), the hydraulic system 140 , the patient support 120 , and a control system 200 . The control system 200 includes two 16-channel transmitting/receiving switch units 201 for the transmitting/receiving antenna disk 170 , two 16-channel receiving switch units 202 for each of the receiving antenna disks 170 , a control unit 203 , a network analyzer 204 , a power unit 205 , one or more fan units 206 , a hub 207 , and a user interface computer 208 . In at least some embodiments, the switch units 201 , 202 , control unit 203 , network analyzer 204 , power unit 205 , fan units 206 , and hub 207 are supported on a rack 209 in the control cabinet 135 . The user interface computer 208 may be supported on or in the enclosure 134 or may be supported elsewhere, such as on a nearby desk, a user's lap, or in some cases even outside the room.
FIG. 23 is a schematic representation of the operation of the rings 180 of antennas 173 around the imaging domain, which is defined by the imaging chamber. The general task is to make complex Si,j,k parameters matrix measurement, where i is the transmitting antenna (i=1 . . . 32), j is the receiving antenna (j=1 . . . 31), and k is the ring of the receiving antenna (k=1 . . . 5). The more practical case for the number of receiving antennas that are measured for each transmitting antenna may be between 12 and 20 (i.e., only receivers generally opposite the transmitting antenna), and the most practical case may be for 17 receiving antennas to be measured for each transmitting antenna, but other numbers are also viable. Typical attenuations may be ˜90 dB to ˜130 dB. In at least some embodiments, frequencies may be 0.8-1.5 GHz, step 50 MHz. In at least some embodiments, channel-to-channel isolation may be ˜80 dB to ˜100 dB. In at least some embodiments, maximum power output may be +20 dBm (100 mW). In at least some embodiments, single frame data acquisition time may be less than 60 mSec (“frame” being defined as the full cycle of S matrix measurements). In at least some embodiments, the number of acquired frames may be from 1 to 1000. In at least some embodiments, the dielectric properties of the matching media between antennas and object may be ˜(30-to-60)+j(15-to-25).
FIGS. 24A and 24B are a more detailed schematic diagram of the control system 200 of FIG. 22 . As shown therein, the hub 207 , which may provide both wireless and wired connections, communicatively connects the control unit 203 , the network analyzer 204 , and the user interface computer 208 . The control unit 203 includes a host controller that interfaces with the hub 207 as well as provides a trigger input to the network analyzer 204 and receives “ready for trigger” and/or “busy” signals from the network analyzer 204 . The host controller also receives an ECG input and controls drivers for MW switches. The control unit 203 also includes various circuitry, including amplifiers, multiplexers, and the like, to generate input signals for the ports of the network analyzer 204 , which may be a ZVA 4 port vector network analyzer available from Rohde & Schwarz. The network analyzer 204 is also communicatively connected to the hub 207 , preferably via a LAN, and operations of the control unit 203 and network analyzer 204 are under the control of the user interface computer 208 . Power is supplied by a power converter which may receive 24V power from the power unit 205 as described elsewhere herein.
FIG. 25 is a schematic diagram of one of the transmitting/receiving switch units 201 of FIG. 22 , and FIG. 26 is a schematic diagram of one of the receiving switch units 202 of FIG. 22 . FIG. 27 is a schematic diagram of the power unit 205 of FIG. 22 . As shown therein, the AC line input is converted into power for the hub 207 , the network analyzer (VNA) 204 , and for 24V AC/DC converters used to power the control unit 203 and transmitter/receiver and receiver switch units 201 , 202 . FIG. 28 is a schematic block diagram of additional or alternative details of a control system for the EMT system 110 .
In operation, a patient 15 is placed on his back on a patient support 120 and transported to the image chamber unit 131 , shown in FIG. 9 , or the image chamber unit 131 is transported to the location of the patient 15 . For sanitary purposes, a single-use protective cap (not shown) may be placed over the patient's head 19 . Such a protective cap may be made of plastic, latex, or the like. The patient's head 19 is then inserted into the entry opening 169 in the working chamber 122 as shown in FIG. 11 . The headrest 118 may be adjusted as necessary or desired to arrange the patient's head in the desired position and orientation within the working chamber 122 . The patient's head 19 bears against the membrane 133 , which then conforms to the shape of the patient's head 19 . With the patient's head 19 properly arranged, a technician fills the working chamber with a quantity of the prepared matching liquid. Filling may be carried out using the remote control of the pump, which in at least some embodiments has toggle switches to start and stop the pump, control the direction of flow (in or out), and flow rate. Filling is preferably initiated at a low flow rate to avoid splashing of matching liquid. Matching liquid is pumped into the working chamber until it is full, as shown in FIG. 15 .
In addition to filling the working chamber with the matching liquid, the technician may also power on the various electronic components, including the control unit, the network analyzer, transmitter and receiver units, and the like. Using the user interface computer, software may then be utilized to calibrate and operate the system. Functionally, much of the operation of the EMT system 110 may be similar to that described in the aforementioned U.S. Pat. No. 7,239,731, U.S. Patent Application Publication No. 2012/0010493 A1 (U.S. patent application Ser. No. 13/173,078), and/or U.S. Patent Application Publication No. 2014/0276012 (U.S. patent application Ser. No. 13/894,395), but various particular embodiments and features thereof may be described herein. Measurements are taken, a matrix of complex data is generated, and various algorithms are used to transform such data into tomographic images of the interior of the patient's head 19 .
Other embodiments of the present invention are likewise possible. In particular, EMT systems having components that are more easily transported than those of the system 110 described hereinabove are possible without departing from the scope of the present invention. In this regard, FIGS. 29 and 30 are a top front perspective view and a bottom rear perspective view, respectively, of another EMT system 210 for imaging a human head 19 in accordance with one or more preferred embodiments of the present invention. The system 210 includes an image chamber unit 231 , a control cabinet 235 , and a hydraulic system 240 for supplying, circulating, and otherwise managing a matching fluid to the image chamber unit 231 . The entire system 210 may be carried on a patient support 220 , which again may be a gurney, cart, table, stretcher, or the like. In particular, the image chamber unit 231 , which includes a built-in headrest 218 , is carried on a top surface of the patient support 220 , near one end, and the control cabinet 235 is carried beneath the patient support 220 . Such a system 210 may be more conveniently transported, and in particular, the system 210 may be rolled with the patient support 220 onto and off of an ambulance and into a medical facility. In this regard, FIG. 31 is a top plan view of the system 210 in use in an ambulance 211 .
In at least some embodiments, an image chamber unit of a type described herein is man-portable. As used herein, “man-portable” means cable of being carried or borne by one human. In particular, an image chamber unit of a type described herein may take the form of a wearable hat, helmet, cap, or the like. FIG. 32 is a side perspective view of a cap serving as a wearable image chamber unit in accordance with one or more preferred embodiments of the present invention. Aspects of such wearable apparatuses may be described, for example, in U.S. patent application Ser. No. 13/894,395.
At least some embodiments of the EMT systems presented herein, including without limitation the mobile embodiments such as the one presented in FIGS. 29-31 and the wearable cap of FIG. 32 , may be utilized advantageously outside of the clinical setting. FIG. 33 is a pictorial illustration of a timeline for use of an EMT system, including the cap of FIG. 32 , for imaging a human head in response to the onset of stroke symptoms in a patient. As shown therein, at 8:00 pm, a patient may be resting at home when he experiences the onset of stroke-like symptoms, such as disorientation and weakness in the face and arms. In response, he or a family member or friend contacts a medical provider, and an ambulance is dispatched. Meanwhile, a doctor or other medical practitioner is contacted and updated on the situation. The patient's head is placed in a mobile imaging unit, and scanning begins as shown around 8:25 pm. (In FIG. 33 , the mobile image chamber unit is the cap of FIG. 32 , but it will be appreciated that the unit of FIGS. 29-31 may be used instead.) Resulting data may be provided to the doctor, ambulance staff, imaging specialists, and other personnel. Some of the data may be used directly for diagnosis, treatment, or the like, while complex image-related data may be processed according to the systems and methods of the present invention to reconstruct images from which further diagnosis, treatment, or the like may be triggered. In at least some embodiments, such processing may generate an automatic alert that the data indicates that a potential stroke is likely. Notably, in at least some embodiments, such processing is carried out by a third party service provider who specializes in reconstruction of images according to the systems and methods of the present invention. During transport, from approximately 8:45 pm to 9:00 pm, the cap 331 continues to provide data regarding the patient's condition, and the local hospital staff is further updated and arranges and prepares for further treatment. Once the patient arrives at the hospital or other treatment center, the images and data may be used in providing timely, accurate information about the status of the stroke injury, and appropriate treatment and follow-up may be administered. Such a system could be utilized to provide the desired “under 3 hour” treatment that can make a major difference in the final outcome of the stroke injury and its affect on the patient.
It will be appreciated that in at least some embodiments, the systems, apparatuses and methods presented hereinabove may be incorporated into a 4D EMT differential (dynamic) fused imaging system. 4D EMT differential (dynamic) fused imaging system suitable for use with one or more preferred embodiments of the present invention are described in Appendix B.
Based on the foregoing information, it will be readily understood by those persons skilled in the art that the present invention is susceptible of broad utility and application. Many embodiments and adaptations of the present invention other than those specifically described herein, as well as many variations, modifications, and equivalent arrangements, will be apparent from or reasonably suggested by the present invention and the foregoing descriptions thereof, without departing from the substance or scope of the present invention.
Accordingly, while the present invention has been described herein in detail in relation to one or more preferred embodiments, it is to be understood that this disclosure is only illustrative and exemplary of the present invention and is made merely for the purpose of providing a full and enabling disclosure of the invention. The foregoing disclosure is not intended to be construed to limit the present invention or otherwise exclude any such other embodiments, adaptations, variations, modifications or equivalent arrangements; the present invention being limited only by the claims appended hereto and the equivalents thereof.
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An electromagnetic tomography system for gathering measurement data pertaining to a human head includes an image chamber unit, a control system, and a housing. The image chamber unit includes an antenna assembly defining a horizontally-oriented imaging chamber and including an array of antennas arranged around the imaging chamber. The antennas include at least some transmitting antennas and some receiving antennas. The control system causes the transmitting antennas to transmit a low power electromagnetic field that is received by the receiving antennas after passing through a patient's head in the imaging chamber. A data tensor is produced that may be inversed to reconstruct a 3D distribution of dielectric properties within the head and to create an image. The housing at least partially contains the antenna assembly and has a front entry opening into the imaging chamber. The head is inserted horizontally through the front entry opening and into the imaging chamber.
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TECHNICAL FIELD
The present invention relates to compositions of matter and processes useful for treating paper and other materials and products which contain cellulosic fibers. More particularly, it relates to increasing the degree to which paper products and fabrics feel soft to the touch.
BACKGROUND INFORMATION
Making paper or textile products soft without impairing performance characteristics such as strength or absorbency has long been the goal of various workers. Softness is the tactile sensation perceived by a person who holds a particular paper or textile product and rubs it across the skin. Such tactilely-perceivable softness can be characterized by, but is not limited to, friction, flexibility, and smoothness, as well as subjective descriptors, such as a feelings of lubriciousness, or softness textures reminiscent of velvet, silk, or flannel. However, improvement of softness in almost all cases comes at the expense of strength or absorbancy of the fibrous material.
One method for improving softeness in paper products is to select or modify cellulose fiber morphologies to those which provide advantageous microstructures. However, while incorporation of upgraded cellulose fiber sources into paper products can improve softness, it is often the case that upgraded fiber sources offer limited ability to confer the properties of durability and absorbency to paper products produced therefrom, and the resulting paper products are typically possessed of the best achieveable balance between softness and strength for the treatment method or system utilised.
Another area that has received a considerable amount of attention in improving paper softness is the addition of chemical softening agents to the fiber furnish during the papermaking process. For example, chemical softening agents can be applied to the paper web during its formation either by adding the softening agent to the vats of pulp which will ultimately be formed into a paper web, to the pulp slurry as it approaches a paper making machine, or to the wet paper web as it resides on a Fourdrinier cloth or dryer cloth on a papermaking machine. In addition, the chemical softening agent can be applied to a finished paper web after it has dried.
To ensure an optimum level of softening efficiency in general, a high degree of attraction of the chemical softening composition to the fibers used in the manufacture of papers is necessary. It has been known that, because of their charge, cationic softeners have a strong affinity for the papermaking fibers and are a good softener. In comparison, anionic debonders, because they have the same charge as the fiber, are not sufficiently retained on the fiber furnish to function effectively as softeners. In addition, anionic debonders contribute to wet-end deposition and significant foaming that is in general overall detrimental to the papermaking process. Nonionic surfactants have no ionic attraction for the fibers whatsoever, and as a result, when nonionics are employed it is necessary for them to be applied to the wet paper web.
During the papermaking process, cationic debonders, when employed, are typically added to water to make an emulsion, and then added to the fiber furnish. Unfortunately, addition of cationic debonders to the fiber furnish often results in a significant reduction of strength in the paper web (strength being the ability of the paper product, and its constituent paper webs, to maintain physical integrity and to resist tearing, bursting, and shredding under use conditions). This reduction in strength is believed to result from a disruption of hydrogen bonds between the papermaking fibers that are formed as a result of the papermaking process. In order to offset the effects of the strength reduction that occurs because of the cationic debonder addition, dry strength additives must be added; however, these additives often negate the softness benefits imparted by the cationic debonder addition.
Various compositions are known in the art as being useful for conferring softness to paper products For example, published US Patent Application number 20020112831 discloses a paper softening composition containing a quaternary ammonium compound, water, and a nonionic surfactant. Other compositions and methods for paper softening are disclosed in U.S. Pat. Nos. 6,458,343; 6,369,007; 6,315,866; 6,245,197; 6,200,938; 6,179,961; 6,004,914; 5,753,079; 5,538,595; 5,385,642; 5,322,630; 5,240,562; 4,959,125; 4,940,513; 4,720,383; 4,441,962; 4,351,699; and 3,554,862, the entire contents of which aforesaid patent documents are herein incorporated by reference thereto in their entirety.
One of the most important physical properties related to softness is generally considered by those skilled in the art to be the strength of the paper web. Accordingly, there is a continuing need for soft paper and textile products having good strength properties. There is also a need for improved softening compositions that can be applied to such paper and textile products to provide the requisite softness without unacceptably degrading the strength of the product.
SUMMARY OF THE INVENTION
The present invention provides chemical softening compositions useful for softening fibers of cellulosic materials, including paper, without seriously detracting from the strength of final products formed through their use. A composition according to the invention includes: an amide-substituted quaternary imidazolinium salt; a nonionic surfactant; and a polyhydroxy compound. In one form of the invention, the nonionic surfactant includes ester adducts of polyethylene glycol, and the polyhydroxy compound is selected from the group consisting of: glycerine, a polyalkylene glycol, or mixtures of the foregoing.
The present invention also provides a process for making a soft durable paper web by applying a chemical softening composition described in accordance with the invention to fibers employed in the papermaking process. Such a process according to the invention comprises the steps of forming an aqueous dispersion of papermaking fibers, dewatering the dispersed fibers by depositing them onto a flat surface, and drying the dispersed fibers sufficiently to form a paper product. The chemical softening composition can be applied directly to the dispersed fibers either prior to, or subsequent to the dewatering step.
A chemical softening composition according to the present invention may also be applied to fabric (that is, articles of clothing, or textiles) to impart softness properties to the fabric, as well as increasing their ease of handling and lubricity, and reducing their tendency to accumulate and store static electricity.
Any cellulosic material, including without limitation paper fibers and fabrics, may be treated in accordance with the present invention. Any material bearing cellulose may be treated by contact with an aqueous solution according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
The chemical softening composition according to the present invention comprises a amide-substituted quaternary imidazolinium salt, a nonionic surfactant, and a polyhydroxy compound. A chemical softening composition according to a preferred form of the invention comprises any amount from about 1.00% to about 20.00% by weight based on the total weight of the finished composition of the amide-substituted quaternary imidazolinium salt. It is preferred that the nonionic surfactant component be present in any amount between 20.00% and 90.00% by weight based upon the total weight of the composition. According to a preferred form of the invention, the polyhydroxy compound component is present in any amount between 1.00% and 20.00% by weight based upon the total weight of the composition.
In order to provide a composition according to the invention, the various components are merely mixed together using conventional mechanical agitation and mixing means known to those with skill in the art as being useful for combining liquids to form mixtures, including blending in a tank or passing the liquids through a static mixer, or other functionally-equivalent means of agitation.
Preferably, the amide-substituted quaternary imidazolinium salt is formed from quaternizing (alkylating) a material having the following general structure:
with dimethyl sulfate, diethyl sulfate, or an monoalkyl halide such as, preferably, the bromides or chlorides of alkanes such as methane and ethane, as such alkylations are well known to those skilled in the art. The material above may be produced by reaction between diethylenetriamine and 2 moles of a carboxylic acid (preferably a fatty acid) and the subsequent removal of water, which techniques are known by those skilled in the art. In addition, such materials are available from HUNTSMAN COMPANY, LLC of The Woodlands, Tex. In the embodiment in which dimethyl sulfate is employed as the alkylating agent, the amide-substituted quaternary imidazolinium salt is the quaternized (quaternary) amide-substituted imidazolinium methosulfate salt (II) having the general structure shown below:
in which R is independently in each occurrence a hydrocarbyl group having any number of carbon atoms between 8 and 22. It is believed to be readily appreciated by those skilled in the art that in cases where sulfates other than dimethyl sulfate are employed in quaternizing, the anion in the formula above will correspond to the anion of the other sulfate used, as such is known to those skilled in the art of the use of sulfates in alkylations.
The term “hydrocarbyl” as used in this specification and the claims appended hereto refers to a hydrocarbon group having a carbon atom directly attached to the remainder of the molecule and having predominantly hydrocarbon character. Examples of hydrocarbyl substituents or groups within this defninition include: (1) hydrocarbon substituents, that is, aliphatic (e.g., alkyl or alkenyl), alicyclic (e.g., cycloalkyl, cycloalkenyl) substituents, and aromatic-, aliphatic-, and alicyclic-substituted aromatic substituents, as well as cyclic substituents wherein the ring is completed through another portion of the molecule (e.g., two substituents together form an alicyclic radical); (2) substituted hydrocarbon substituents, that is, substituents containing non-hydrocarbon groups which, in the context of this invention, do not alter the predominantly hydrocarbon substituent (e.g., halo (especially chloro and fluoro), hydroxy, alkoxy, mercapto, alkylmercapto, nitro, nitroso, and sulfoxy); (3) hetero substituents, that is, substituents which, while having a predominantly hydrocarbon character, in the context of this invention, contain other than carbon in a ring or chain otherwise composed of carbon atoms. Heteroatoms include sulfur, oxygen, nitrogen, and encompass substituents such as pyridyl, furyl, thienyl and imidazolyl. In general, no more than two, preferably no more than one, non-hydrocarbon substituent will be present for every ten carbon atoms in the hydrocarbyl group; typically, there will be no non-hydrocarbon substituents in the hydrocarbyl group.
It is readily appreciable by those skilled in the art that commercial fatty acids may in some cases be comprised of mixtures of fatty acids having different hydrocarbon tails representing a distribution of several different carbon numbers. Accordingly, a finished solution according to the invention when prepared using fatty acids as a raw material will thus often include a mixture of different cations derived from the alkylation of the material defined by the structure of the imidazoline (I) above which may have two hydrocarbyl R groups that individually may either comprise the same or different chain lengths as each other (i.e., both R 1 groups of a given cation, structure (III) below, may be the same or different). According to one form of the invention, the mixture comprises at least two quatrenary cations which differ in structure with respect to the identity of the R 1 groups present, within the meaning of the term hydrocarbyl.
A amide-substituted quaternary imidazolinium salt useful in accordance with the present invention can be prepared by any of the means well known to those skilled in the chemical arts. For example, it can be prepared by forming an amide by reacting 1 mole of diethylenetriamine with 2 moles of a fatty acid selected, without limitation from the group consisting of: oleic acid; palimitic acid; stearic acid; linoleic acid; linolenic acid; decenoic acid; decanoic acid; dodecanoic acid; hexadecanoic acid; octanoic acid; and tetradecanoic acid. Any known carboxylic acid having between 8 and 22 carbon atoms is suitable for forming such amide, whether saturated, mono-unsaturated, or poly-unsaturated. The amide is subsequently quaternized using dimethyl sulfate, which general methylation method is familiar to those skilled in the art.
A chemical softening composition according to one form of the present invention includes from 1.00 percent to 20.00 percent by weight of amide-substituted imidazolinium methosulfate salt. More preferably, the chemical softening composition includes from 3.00 percent to 15.00 percent by weight of the amide-substituted imidazolinium methosulfate salt. Most preferably, the chemical softening composition includes from 5.00 percent to 10.00 percent by weight of the amide-substituted imidazolinium methosulfate salt. It has been found that addition of a chemical softening composition having greater than 20.00 percent by weight of the amide-substituted imidazolinium methosulfate salt during the papermaking process negatively impacts the strength of the paper web during processing as well as the resulting paper product.
The nonionic surfactant of the present invention includes ester adducts of ethylene oxide, polyethylene glycol, polypropylene glycol and fatty materials such as fatty acids, alcohols, and esters. Generally, the fatty moiety of the nonionic surfactant can include from about twelve (12) to about eighteen (18) carbon atoms. The ethylene oxide moiety of the nonionic surfactants can include from two (2) to twelve (12) moles of ethylene oxide.
Examples of nonionic surfactants that can be used are polyethylene glycol dioleate, polyethylene glycol dilaurate, polypropylene glycol dioleate, polypropylene glycol dilaurate, polyethylene glycol monooleate, polyethylene glycol monolaurate, polypropylene glycol monooleate and polypropylene glycol monolaurate. The present invention contemplates the use of any known nonionic surfactant in its compositions and processes.
The nonionic surfactant can also include blends of ester adducts of polyethylene glycol and polypropylene glycol. Particularly preferred are blends of polyethylene glycol dioleate and polyethylene glycol dilaurate. For example, the nonionic surfactant of the present invention can include a blend of polyethylene glycol 400 dioleate and polyethylene glycol 200 dilaurate having from about twenty 20.00 to about eighty 80.00 percent by weight of polyethylene glycol 400 dioleate and from about 20.00 to about 80.00 percent of polyethylene glycol 200 dilaurate. Preferably, the nonionic surfactant blend contains from about thirty 30.00 percent to about seventy 70.00 percent of polyethylene glycol 400 dioleate and from about thirty 30.00 percent to seventy 70.00 percent by weight of polyethylene glycol 200 dilaurate, and most preferably from about thirty five 35.00 percent to about sixty 60.00 percent by weight of polyethylene glycol 400 dioleate and from about thirty five 35.00 percent to about sixty 60.00 percent by weight of polyethylene glycol 200 dilaurate.
The polyhydroxy compound of the present invention can be selected from the group consisting of: polyols, glycerine (glycerol), polyethylene glycols and polypropylene glycols. Preferably, the polyhydroxy compound has an average molecular weight from about 200 to about 4000, more preferably from about 200 to about 1000 and most preferably from about 200 to about 600. An example of a polyhydroxy compound useful as a component of the present invention includes POGOL® 400 sold by HUNTSMAN COMPANY, LLC (The Woodlands, Tex.).
The polyhydroxy compound is added to the chemical softening composition of the present invention so that the chemical softening composition contains from about one 1.00 percent to about twenty 20.00 percent by weight of the polyhydroxy compound. More preferably, the chemical softening composition contains from about one 1.00 percent to about ten 10.00 percent by weight of the polyhydroxy compound, and most preferably from about one 1.00 percent to about five 5.00 percent by weight of the polyhydroxy compound.
The papermaking fibers utilized in the present invention comprises fibers derived from wood pulp. Other cellulosic fibrous pulp fibers, such as cotton linters, bagasse, etc., can be utilized and are intended to be within the scope of this invention. Synthetic fibers, such as rayon, polyethylene and polypropylene fibers, may also be utilized in combination with natural cellulosic fibers. One exemplary polyethylene fiber that may be utilized is PULPEX®, available from HERCULES INCORPORATED. (Wilmington, Del.).
Wood pulps which may be treated using a composition according to the present invention include the chemical pulps such as Kraft, sulfite, and sulfate pulps, as well as mechanical pulps including groundwood, thermomechanical pulp, and chemically-modified thermomechanical pulp. Chemical pulps, however, are preferred raw materials since they impart a superior tactile sense of softness to sheets made therefrom. Those pulps derived from both deciduous trees (hereinafter, also referred to as “hardwood”) and coniferous trees (hereinafter, also referred to as “softwood”) may be utilized. Also treatable in accordance with the present invention are fibers derived from recycled paper, which may contain any or all of the above categories as well as other non-fibrous materials such as fillers and adhesives used to facilitate the original papermaking.
A chemical softening composition according to the present invention can be used with any known technique for preparing paper products. Generally, the process for the manufacture of paper with which the chemical softening composition of the present invention is useful includes the steps of establishing a uniform aqueous dispersion of papermaking fibers, forming that dispersion into a flat sheet, and dewatering and drying the sheet to form paper that can be rolled, cut, and formed as desired into any one of several finished products including napkins, toweling, and facial and toilet tissue. During processing, the chemical softening composition may be applied directly to an aqueous dispersion of papermaking fibers either prior to or after dewatering to provide a soft, durable paper web.
For example, a chemical softening composition according to the invention is used in a typical papermaking process, where an aqueous dispersion of papermaking fibers is first provided from a pressurized headbox. The head box has an opening for delivering a thin deposit of the dispersed fibers onto a Fourdrinier wire to form a wet paper web. As used herein, the terms “paper web” or “wet paper web” are intended to designate any of the nonwoven materials commonly used as paper products from which a portion thereof includes papermaking fibers.
The wet paper web is dewatered to a fiber consistency of between about 7% and about 25% (total web weight basis) by vacuum dewatering and further dried by pressing operations where the paper web is subjected to pressure developed by opposing mechanical members such as cylindrical rolls. The dewatered paper web can then be further pressed and dried by a steam drum apparatus known in the art as a Yankee dryer. Pressure is developed at the Yankee dryer by mechanical means such as an opposing cylindrical drum pressing against the paper web. Multiple Yankee dryer drums can also be employed for additional pressing if necessary or desirable. Subsequent processing such as creping, calendering and/or reeling can also be used to further increase stretch, bulk and softness, and to control caliper.
As described above, the aqueous dispersion of papermaking fibers are obtained by any of the numerous known processes, such as pulp of virgin pulpwood, from recycled paper and/or cardboard stock, or mixtures thereof. The pulp is subjected to treatment by any of several conventional processes to help establish a dispersion of fibers sufficiently finely dispersed to constitute an acceptable dispersion that can be processed into paper. The pulp can also be treated, for example, mechanically, chemically, or both, and is often subjected to heat to convert it to a processable dispersion. Several chemical processes such as the Kraft process are well known in this field.
The papermaking fibers, as that term is used herein, include any of a chemical constituency and physical form that can be formed into an aqueous dispersion that can in turn be produced into paper. Generally the papermaking fibers are predominantly cellulosic but may also contain lignins, hemi-cellulosics, and other fibrous components derived from synthetic polymers, cloth, and the like.
The aqueous dispersion of papermaking fibers is formed into a flat sheet, usually by means of a machine specially adapted for this function. Preferably, a Fourdrinier or equivalent machine presenting a wide, flat, porous screen (which can move at a predetermined rate) has at one end a means such as a headbox which contains the aqueous dispersion of papermaking fibers and which feeds the aqueous dispersion at a controlled rate onto one end of the screen.
The flat sheet formed in this or any equivalent manner still contains a substantial portion of water. As the flat sheet is carried along on the screen, water is removed through the screen by its own weight and often with the aid of pressure, heat, or both. The flat sheet can then be treated with other equipment such as heated calender rollers or the like, which further reduces the moisture content until the sheet is sufficiently dried into paper. The paper is then stored, cut and/or otherwise converted in known manner into useful products.
During processing, a chemical softening composition according to the invention may be added at any one of a variety of locations. For example, the chemical softening composition can be added to the locations where the papermaking fibers are in aqueous dispersion such as the head box, the machine chest or stuff box. The chemical softening composition can also be sprayed onto a wet paper web or applied to a dried paper web. The chemical softening composition can also be effectively applied to the papermaking fibers during the drying process or subsequent to the drying process, such as spraying the chemical softening composition onto the calender rolls.
Preferably, the chemical softening composition is applied to the aqueous dispersion of papermaking fibers prior to dewatering. It has been found that the chemical softening composition of this invention is highly retained on the papermaking fibers when it is added to the aqueous dispersion of papermaking fibers before formation of the paper web or to a wet paper web, therefore making the chemical softening composition highly effective.
While not wishing to be bound by theory, it is believed that, due to the formation of mixed component micelles, the nonionic surfactant and polyhydroxy components of the chemical softening composition described in this invention have the ability to retain on the papermaking fibers when the chemical softening composition is added to an aqueous dispersion of fibers before they are formed into a wet web. The mixed micelles contain mixtures of the amide-substituted imidazolinium methosulfate salt, nonionic surfactant and polyhydroxy compound. The cationic nature of the imidazoline makes the chemical softening composition highly attractive to the fibers. The aggregation or the interaction of the nonionic surfactants and polyhydroxy components with imidazoline results in retention of the nonionic components on the fibers. This phenomenon has been found to lead to a synergistic mixture, resulting in an improved softness when compared to use of the individual components alone. Furthermore, it is believed that the chemical softening composition reduces the surface tension on and within the interstices of the papermaking fibers, thereby debonding them yet also permitting them to mesh together more closely, thus providing a stronger sheet of paper.
In addition, a reduction in, or elimination of, foaming can be expected when using a chemical softening composition according to the invention when it is added to the papermaking fibers at the wet-end of the process. That is, the nonionic surfactant, polyhydroxy compound and the amide substituted amide-substituted quaternary imidazolinium (methylsulfate or ethylsulfate) salt will increase surface tension to levels significantly higher than those obtained when using either an anionic surfactant alone, or an unbalanced blend of anionic and cationic softening agents.
The present invention provides a chemical softening composition having the ability to impart to fabric (that is, articles of clothing, textiles, and so forth), properties including softness to the touch, ease of handling, increased lubricity, and a reduced tendency to carry or generate static electricity. One form in which the chemical softening composition of the present invention is provided is as a liquid, for instance, as an emulsion or as a solution/suspension. During use, an appropriate controlled amount of the chemical softening composition is employed, for example, by pouring the liquid chemical softening composition directly into a washing machine. Typically, the liquid chemical softening composition is dispensed during the rinse cycle of the washing machine by either pouring in by hand or metering in by an appropriate automatic metering device with which the washing machine is equipped. What now follows is illustrative of the invention, and not delimitive in any way.
EXAMPLE 1
Tissue Softness and Stability Evaluation
Test solutions were prepared to determine the ability of a chemical softening composition according to the present invention to soften paper. The test solutions used during this evaluation were prepared in deionized (DI) water so as to make a one (1) percent by weight solution of the materials described for each Sample described below:
Sample 1: Eighty 80.00% by weight of a amide-substituted quaternary imidazolinium methylsulfate salt having the general structure:
wherein R is an oleic acid residue, is combined with twenty 20.00% by weight POGOL.RTM. 400. This product is sold by Huntsman Company, LLC (The Woodlands, Tex.) under the trade name “HARTOSOFT.RTM. DBS-5080M”.
Sample 2: pure Polyethylene glycol (“PEG”) 200 dilaurate. Sample 3: pure PEG 400 dioleate. Sample 4: 10% by weight of Sample 1+90% by weight of PEG200 dilaurate. Sample 5: 10% by weight of Sample 1+40% by weight of PEG 400 dioleate+50% by weight of PEG 200 dilaurate. Sample 6: 10% by weight of Sample 1+20% by weight of PEG 400 dioleate+70% by weight of PEG 200 dilaurate. Sample 7: 10% by weight of Sample 1+20% by weight of PEG 600 DO+70% by weight of PEG200 dilaurate. Sample 8: 10% by weight of Sample 1+20% by weight of PEG 400 MO+70% by weight of PEG200 dilaurate. Sample 9: PEG 400 MO.
The test solutions were then assessed for their ability to soften paper using 7″×3″ sections of untreated standard tissue paper. Each tissue was immersed into the specified test solution for 60 seconds and then withdrawn. The treated tissue samples were then dried in an oven at 25° C. The treated tissues were evaluated objectively and ranked for softness to the touch using the following scale:
0=Poor/harsh texture 1=Fair 2=Good 3=Very Good 4=Excellent/very soft texture
The results of this testing are reported below in Table 1:
TABLE 1
Sample
Softness
Deionized Water
0
Sample 1
3
Sample 2
3
Sample 3
3
Sample 4
3.5
Sample 5
4
Sample 6
3.5
Sample 7
—
Sample 8
—
Sample 9
1.5
The inventive chemical softening compositions, Samples 5, 6, and in particular Sample 5, show superior softness as compared to the prior art.
The stability of the test solutions was also evaluated. The following scale was used to grade the stability of the test solutions:
0=very unstable (i.e. solution separates into visible layers within 1 minute) 1=fair 2=good 3=very good 4=excellent
The results of this testing is reported below in Table 2:
TABLE 2
Stability of 1%
Sample
Test Solution
Sample 1
1
Sample 2
0
Sample 3
0
Sample 4
1
Sample 5
3
Sample 6
2
Sample 7
⅔
Sample 8
⅔
Sample 9
3
It is shown that inventive Sample 5 is much more stable than the prior art treatments, as well as the individual components, thus indicating unexpected beneficial interactions between the amide-substituted quaternary imidazolinium methylsulfate salt, the nonionic surfactant and the polyhydroxy compound. Furthermore, Sample 5 was found to have a very low pour point (ASTM D-97), below 10° C., as compared to about 31° C. for Sample 2. Therefore, addition of a nonionic surfactant blend of PEG 400 dioleate and PEG 200 dilaurate to the amide-substituted quaternary imidazolinium methosulfate salt and polyhydroxy compound is demonstrated to lower the pour point significantly. Thus, in addition to providing superior softness and strength to paper web and its resulting paper product, the chemical softening composition of the present invention is shown to exhibit low pour points, is low foaming, and excellent dispersibility in water.
While the aforesaid embodiments are concerned with a single most preferred imidazolinium salt, the present invention embraces aqueous compositions which comprise a cation having the structure:
wherein R 1 in each occurrence is independently selected from the group consisting of: hydrogen or any hydrocarbyl group comprising 8 to 22 carbon atoms and wherein R 2 is selected from the group consisting of: hydrogen, methyl, or ethyl. The anionic counterion present with such a cation is really of little consequence to the overal performance of a solution according to the invention as heretofore described. Thus any suitable counteraion sufficient to render the solution as a whole electronically neutral is useful in accordance with the present invention. Dimethyl sulfate is a particularly preferred material for the alkylation and the presence of the methylsulfation anion is merely for convenience. Alkylations carried out using, say, methyl chloride or ethyl chloride, will result in a halide anion being present in the product, which is of no detriment from a performance standpoint. Suitable alkylating agents known in the art which are capable of alkylating the nitrogen atome bearing a methyl group in the above structure and having any number of carbon atoms between 1 and 12 are suitable for use in preparing an imidazolinium cation suitable for use in accordance with the present invention. However, as the alkyl chain becomes longer than about 2 carbon atoms, reaction product yields are adversely affected by the bulkiness of such substituents (steric effects) and for this reason alone the methyl and ethyl substituted materials are preferred components of a composition according to the invention.
Consideration must be given to the fact that although this invention has been described and disclosed in relation to certain preferred embodiments, obvious equivalent modifications and alterations hereof will become apparent to one of ordinary skill in this art upon reading and understanding this specification and the claims appended hereto. Accordingly, the presently disclosed invention is intended to embrace all such modifications and alterations, and is limited only by the scope of the claims which follow.
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A chemical softening composition includes a amide-substituted quaternary imidazolinium salt, a nonionic surfactant, and a polyhydroxy compound for use in treating cellulosic materials including papers, textiles and fabrics. The chemical softening composition can be applied to papermaking fibers during a papermaking process to provide a softened paper web and product possessed of sufficient tensile strength for its regular employment. A chemical softening composition according to the invention can also be applied to fabric to soften the fabric, provide easier handling of the fabric, and also reduce the tendency of the fabric to generate and store static electricity.
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RELATED APPLICATIONS
This patent application claims priority to U.S. Provisional Patent Application Ser. No. 61/106,569 filed on Oct. 18, 2008, which is incorporated by reference in its entirety.
FIELD OF THE INVENTION
This invention relates in general to a method and apparatus for installing and supporting an electrical submersible pump cable, and in particular to an electrical submersible pump cable having spring loaded anchors for engaging an inside wall of coiled tubing after application of heat.
BACKGROUND OF THE INVENTION
Electrical submersible pumps (ESP) are normally installed on jointed production tubing and powered by an ESP cable attached to the outside of production tubing. All produced fluids are pumped up the production tubing to the surface.
Oil well completions are being developed to deploy ESPs on the bottom of continuous coiled tubing where the power cable is placed inside the coiled tubing. In these installations, produced fluids are pumped up the annulus between the coiled tubing and the production tubing, or well casing or liner. Many advantages are gained through the use of coiled tubing such as faster deployment, the elimination of a need for large workover rigs, and less frictional pumping losses.
Because an ESP cable cannot support its total vertical weight, cable support must be provided by the coiled tubing at regular intervals. Various proposals have been made to provide support, such as the use of dimpling and welding of the coil tubing after pulling the ESP cable through the tubing; however, improvements would be desirable.
SUMMARY OF THE INVENTION
Disclosed herein is an apparatus that allows for the transfer of the weight of a power cable to borehole tubing, such as coiled tubing, using compressible anchor assemblies and support pins. In one embodiment, the apparatus for supporting the weight of the power cable within the tubing in a borehole has a length of tubing, a length of power cable, a body member, a frangible support element and an anchor assembly. The body member is coupled to a portion of the outer periphery of the cable, with the body member having a first outer diameter and a second outer diameter, wherein the second outer diameter creates a flange for the anchor assembly. In one embodiment, the body member has an inner radius, the inner radius having helical grooves that match the power cable's pitch. When the body member is coupled to the power cable, a threaded connection is formed. Once the body member is coupled to the power cable, the anchor assembly is compressed to fit around the outer periphery of the body member. In an embodiment in which the frangible support element is a support pin, the support pin can be inserted through the anchor assembly's leaf springs such that the anchor assembly is fixed in a compressed state and coupled to the body member. In one embodiment of the present invention, there is a plurality of body members located along the length of the power cable, as well as a plurality of anchor assemblies located on each of the respective body members.
Once all of the anchor assemblies are in place and compressed, the cable may be transferred into the borehole tubing. The frangible support elements are subjected to a treatment method such that the support elements fail, causing the anchor assemblies to decompress and contact the inner wall of the borehole tubing. This contact point between the anchor assemblies and the inner wall of the borehole tubing acts to transfer the weight of the power cable to the borehole tubing.
In one embodiment of the present invention, the frangible support element is designed to fail at a predetermined temperature, such that support element can be heated to induce failure. In other embodiments of the present invention, the support element can be designed to fail at increased pressures, electrical charges, resonate frequency, or upon exposure to a solvent.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial longitudinal cross sectional view illustrating an electrical cable and coiled tubing assembly constructed in accordance with an embodiment of the present invention.
FIG. 2 is the same partial sectional view as FIG. 1 following a treatment method.
FIG. 3 is a cross sectional view along line 3 - 3 of FIG. 1 .
FIG. 4 is a side view of the anchor assembly and support pin in accordance with an embodiment of the present invention.
FIG. 5 is a cross sectional view of the body member and anchor assembly and a side view of the electrical cable in accordance with an embodiment of the present invention.
FIG. 6 is a side view along line 6 - 6 of FIG. 5 .
FIG. 7 is an alternate embodiment of the apparatus shown in FIG. 6 .
DETAILED DESCRIPTION OF THE INVENTION
The present invention will now be described more fully hereinafter with reference to the accompanying drawings in which embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the illustrated embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout. For the convenience in referring to the accompanying figures, directional terms are used for reference and illustration only. For example, the directional terms such as “upper”, “lower”, “above”, “below”, and the like are being used to illustrate a relational location.
It is to be understood that the invention is not limited to the exact details of construction, operation, exact materials, or embodiments shown and described, as modifications and equivalents will be apparent to one skilled in the art. In the drawings and specification, there have been disclosed illustrative embodiments of the invention and, although specific terms are employed, they are used in a generic and descriptive sense only and not for the purpose of limitation. Accordingly, the invention is therefore to be limited only by the scope of the appended claims.
With reference now to FIG. 1 , the electrical power line for a submersible pump includes a string of continuous coiled tubing [ 10 ]. Coiled tubing [ 10 ] is steel, has an outer diameter [ 11 ] and an inner wall [ 13 ] and is of conventional materials and dimensions. Coiled tubing [ 10 ] is capable of being wound on a large reel for transport to a well site, and then forced into a well. Power cable [ 20 ] is shown inserted through the length of coiled tubing [ 10 ]. Power cable [ 20 ] is a type particularly for supplying AC power from the surface to a downhole motor for driving a centrifugal pump (not shown), which is located at the lower end of coiled tubing [ 10 ].
As shown in FIG. 3 , power cable [ 20 ] has three insulated conductors [ 22 ], each surrounded by an insulation layer [ 24 ]. An elastomeric jacket [ 26 ] is extruded over the three insulated conductors [ 22 ]. Elastomeric jacket [ 26 ] has a cylindrical outer diameter which is helically wrapped with a metal strip of armor [ 28 ], which forms helically spaced grooves [ 30 ] ( FIG. 1 ). In one embodiment, elastomeric jacket [ 26 ] is of a material, such as Nitrile rubber, which resists swelling when exposed to hydrocarbon liquid. In this embodiment, tightly wrapped armor [ 28 ] deforms elastomeric jacket [ 26 ] and provides adequate frictional engagement between elastomeric jacket [ 26 ] and minor [ 28 ], preventing slippage due to the weight of power cable [ 20 ].
Referring back to FIG. 1 , a plurality of body members [ 40 ] are mounted to power cable [ 20 ] at selected intervals. Each body member [ 40 ] has an anchor assembly [ 50 ] coupled on the body member's outer periphery.
In FIG. 2 , anchor assembly [ 50 ] has been released such that it is no longer in its compressed state. In one embodiment, anchor assembly [ 50 ] releases upon the application of heat to the coiled tubing. In other embodiments of the present invention, the release of anchor assembly [ 50 ] can be triggered by increased pressure, electrical charges, resonate frequency, or solvents. As shown in FIG. 2 , anchor assembly [ 50 ] contacts inner wall [ 13 ] of coiled tubing [ 10 ], thereby transferring the weight of power cable [ 20 ] to coiled tubing [ 10 ].
FIG. 3 represents a cross sectional view along line 3 - 3 of FIG. 1 . In one embodiment, anchor assembly [ 50 ] is made up of a first engaging member [ 52 ] and a second engaging member [ 54 ]. In another embodiment, anchor assembly [ 50 ] can be made up of only one engaging member that wraps around the entire circumference of the body member [ 40 ], and therefore only uses one frangible support element [ 60 ]. In one embodiment, each engaging member [ 52 , 54 ] can comprise a strip of resilient metal, such as steel. Each engaging member [ 52 , 54 ] has a set of lips at the engaging member's [ 52 , 54 ] edge, which form piano hinge [ 56 ] when interlocked together. In one embodiment, frangible support element [ 60 ] ( FIG. 4 ) can be a support pin and can be inserted into piano hinge [ 56 ], and thereby lock first engaging member [ 52 ] and second engaging member [ 54 ] together in a compressed, substantially cylindrical form. The deflection of each engaging member [ 52 , 54 ] from relatively flat to semi-cylindrical is below the yield point of the metal, such that engaging members [ 52 , 54 ] are elastic. In this compressed form, anchor assembly [ 50 ] is coupled to the body member by contacting the outer periphery of the first outer diameter [ 62 ] of the body member. Referring to FIG. 5 , second outer diameter [ 64 ] of the body member [ 40 ] has a diameter larger than that of first outer diameter [ 62 ] such that it forms a lower flange [ 65 ] and an upper flange [ 67 ]. Lower flange [ 65 ] keeps anchor assembly [ 50 ] from sliding downward when anchor assembly [ 50 ] is in a compressed state. Upper flange [ 67 ] supplies a downward force on anchor assembly [ 50 ], thereby preventing power cable [ 20 ] from slipping downward relative to anchor assembly [ 50 ] when anchor assembly [ 50 ] is in its decompressed state. Dashed lines [ 70 , 72 ] in FIG. 3 represent first engaging member [ 52 ] and second engaging member [ 54 ], respectively, following shearing of frangible support element [ 60 ] ( FIG. 4 ). As shown in FIG. 3 , once anchor assembly [ 50 ] is no longer compressed, first and second engaging members [ 52 , 54 ] spring out to contact the inner wall [ 13 ] of the coiled tubing [ 10 ], while also contacting first outer diameter [ 62 ] of body member [ 40 ].
FIG. 4 represents a side view of one embodiment of anchor assembly [ 50 ]. In the embodiment shown, anchor assembly [ 50 ] has first engaging member [ 52 ] and second engaging member [ 54 ]. When the two engaging members are compressed together, their respective lips interlock to form piano hinge [ 56 ]. Frangible support element [ 60 ] can then be inserted into piano hinge [ 56 ] in order to lock anchor assembly [ 50 ] into its compressed form. In one embodiment, each engaging member [ 52 , 54 ] contains a plurality of outward-protruding tabs [ 55 ] formed by perforations. Tabs [ 55 ] are operable to contact inner wall [ 13 ] of coiled tubing [ 10 ] when anchor assembly [ 50 ] is in its decompressed position. In one embodiment of the present invention, outward-protruding tabs [ 55 ] are shaped like the gratings of a cheese grater.
FIG. 5 represents a cross-sectional view of one embodiment of the present invention in which anchor assembly [ 50 ] is coupled to the outer periphery of body member [ 40 ]. In one embodiment, body member [ 40 ] has two symmetrical, semi-cylindrical body halves [ 74 , 76 ]. Each body half has a first outer diameter [ 62 ], lower flange [ 65 ], upper flange [ 67 ] (collectively “flanges”), and an inner diameter [ 66 ]. In an embodiment, flanges [ 65 , 67 ] are larger in diameter than first outer diameter [ 62 ]. Furthermore, in an embodiment of the present invention, flanges [ 65 , 67 ] are larger in diameter than the diameter of the sprung anchor assembly's load shoulder. The load shoulder is the upper edge portion of engaging members [ 52 , 54 ] which abut upper flange [ 67 ]. This allows anchor assembly [ 50 ] to provide an upward force to the upper flange [ 67 ], which in turn allows for transference of power cable's [ 20 ] weight to coiled tubing [ 10 ]. Additionally, FIG. 5 demonstrates how the pitch of inner diameter [ 66 ] matches helically spaced grooves [ 30 ] of power cable [ 20 ]. This matching of the pitch forms a threaded connection, which prevents power cable [ 20 ] from sliding down body member [ 40 ] when placed within the wellbore. FIG. 5 also demonstrates one embodiment in which body halves [ 74 , 76 ] do not meet, and thus only partially surround power cable [ 20 ]. This allows frangible support element [ 60 ] to be more easily inserted into piano hinge [ 56 ].
FIG. 6 represents a side view along line 6 - 6 of FIG. 5 . As shown, each body half [ 74 , 76 ] partially surrounds the outer periphery of the power cable [ 20 ], and each body half [ 74 , 76 ] also has a second outer diameter [ 64 ] that is larger than the first outer diameter [ 62 ] thereby forming lower flange [ 65 ] and upper flange [ 67 ].
FIG. 7 represents an optional embodiment in which combined body halves [ 74 , 76 ] completely surround power cable [ 20 ]. In this embodiment, each body half [ 74 , 76 ] can have a semi-circular aperture that form receiving aperture [ 61 ] when the body halves [ 74 , 76 ] are mated. Receiving aperture [ 61 ] is preferably sized to accommodate frangible support element [ 60 ].
In order to install the power cable [ 20 ] within the coiled tubing [ 10 ], the user pulls the power cable [ 20 ] through the coiled tubing [ 10 ] while anchor assembly [ 50 ] is secured in its compressed state. In one embodiment, once the power cable [ 20 ] is in place, the user can then apply heat to coiled tubing [ 10 ], preferably localized heat located near each anchor assembly [ 50 ], for example with a controlled induction heater, such that frangible support elements [ 60 ] melt, allowing engagement members [ 52 , 54 ] to spring open, thereby engaging inner wall [ 13 ] of coiled tubing [ 10 ]. In other embodiments of the present invention, a solvent can be pumped through the coiled tubing [ 10 ] and contact frangible support elements [ 60 ], causing frangible support elements [ 60 ] to dissolve or weaken to the point frangible support elements [ 60 ] shear and release engaging members [ 52 , 54 ] from their compressed state. In embodiments using heat to shear frangible support element [ 60 ], a solder having a liquidous temperature below the temperature that can harm the power cable can be used, and preferably a eutectic solder can be used. In one embodiment, frangible support element [ 60 ] has a fail temperature around 300° F. In embodiments wherein frangible support element [ 60 ] can be dissolved, a number of plastics are acceptable, for example, polypropylene or nylon.
The invention has significant advantages as embodiments of the present invention do not require the user to make indentions along the length of the coiled tubing, which can be time consuming, imprecise, and damaging to the power cable.
While the invention has been shown or described in only some of its forms, it should be apparent to those skilled in the art that it is not so limited, but is susceptible to various changes without departing from the scope of the invention.
The present invention described herein, therefore, is well adapted to carry out the objects and attain the ends and advantages mentioned, as well as others inherent therein. While a presently preferred embodiment of the invention has been given for purposes of disclosure, numerous changes exist in the details of procedures for accomplishing the desired results. These and other similar modifications will readily suggest themselves to those skilled in the art, and are intended to be encompassed within the spirit of the present invention disclosed herein and the scope of the appended claims. For example, screws can be added in various places to add additional stability. For instance, screws can be added on the flanges to ensure tight contact with the power cable. Additionally, the anchor assembly could be screwed into the body member. While the invention has been shown in only one of its forms, it should be apparent to those skilled in the art that it is not so limited but is susceptible to various changes without departing from the scope of the invention. Additionally, the present invention may suitably comprise, consist or consist essentially of the elements disclosed and can be practiced in the absence of an element not disclosed. It is intended that all such variations within the scope and spirit of the invention be included within the scope of the appended claims.
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An electrical line for installation in a well for transmitting power to a well pump includes a string of coiled tubing. An electrical cable having insulated electrical conductors embedded within an elastomeric jacket extends longitudinally through the interior passage of the tubing. Body members are placed around the outer periphery of the electrical cable, and the body members are compressed onto the electrical cable through the use of an anchor assembly. The anchor assembly is held in a compressed state through the use of frangible support elements. Once the electrical cable is in place within the coiled tubing, the user applies an external force to cause the support elements to fail, thereby releasing the anchor assembly from its compressed state. The anchor assembly contacts the inner wall of the coiled tubing, such that the weight of the electrical cable is transferred to coiled tubing.
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BACKGROUND OF THE INVENTION
This invention relates in general to a system for ejecting a missile from a submarine and, in particular, to a system in which the energy imparted to the missile during ejection may be selected according to the launch depth.
Present missile eject systems are fixed energy systems that provide a pressure pulse to launch a missile in a predictable manner. During submerged launches part of the fixed energy is used to overcome static sea head pressure. Thus the velocity of the missile at exit from the launch tube will vary inversely with the launch depth.
It would be desirable if the missile eject velocity could be varied with launch depth, This would allow the missile eject velocity to be optimized for the launch depth in view of submarine shock protection requirements and missile cavitation constraints. This improvement requires that the eject system be capable of altering the amount of energy imparted to the missile.
It is also desirable that the improved system be compatible with a present missile eject system so that the present system may be modified to be capable of altering the amount of energy imparted to the missile. This requires that changes to the present eject system be minimized and that the modifications be easily installed. The modifications should be reliable and should be easily accessible for maintenance. Since this is a submarine system, space and weight requirements should be minimized.
In a prior fixed energy system, hot gas from a solid propellant rocket motor provides the ejection energy. The hot gas is directed through cooling apparatus in which a cooling liquid (water) is injected into the hot gas through a plurality of injection apertures to reduce the temperature of the gas to prevent premature ignition of the missile propellant.
SUMMARY OF THE INVENTION
It is therefore the primary object of the present invention to provide a submarine missile eject system in which the energy applied to the missile may be varied.
Another object of the present invention is to provide a submarine missile eject system in which the missile eject velocity may be optimized for the launch depth.
Another object of the present invention is to provide a missile eject system in which the eject velocity may be increased with launch depth.
Another object of the present invention is to provide a means for modifying a present submarine missile eject system to vary the ejection energy imparted to the missile so that the missile eject velocity may be optimized for the launch depth.
These and other objects are provided by a missile eject system in which the rate at which the cooling liquid is injected into the hot gas from the solid propellant rocket motor may be varied to selectively vary the energy imparted to the missile. The preferred embodiment has a first set of injection apertures through which cooling liquid is always injected and which provides the necessary cooling of the hot gas to prevent premature ignition of the missile propellant. This first set provides the maximum energy to the missile and is used for the deepest launch. Additional sets of injection apertures having varying numbers of injection apertures are individually controlled to allow the rate at which cooling fluid is introduced into the hot gas to be varied according to the launch depth.
The advantages and features of the present invention will become apparent from the following detailed description when considered in conjunction with the accompanying drawings wherein:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic partially cross-sectional view illustrating the variable energy missile eject system;
FIG. 2 is a view taken along lines 2--2 in FIG. 3 with the cylindrical surface rolled out to present a plan surface;
FIG. 3 is an expanded schematic view of a rotary valve assembly and its associated water injection apertures;
FIG. 4 taken along line 4--4 in FIG. 1 is a schematic cross-sectional view illustrating the location of the valve assemblies and associated injection apertures viewed from the top;
FIG. 5 is a cross-sectional view taken along lines 5--5 in FIG. 1;
FIG. 6 is a schematic drawing illustrating a rotary actuator drive circuit;
FIG. 7 is a diagramatic view showing the missile eject system coupled to a missile launch tube;
FIG. 8 is a table illustrating valve combinations for producing 21 energy levels; and
FIGS. 9a-9d are schematic drawings illustrating the operation of the missile eject system.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings and, in particular to FIG. 1, the preferred embodiment of the improved missile eject system includes a solid propellant rocket motor 10 having an output nozzle 12 directed into the central chamber 14 of a standpipe 16. A mylar diaphragm 18 is disposed to seal the rocket motor 10 from the central chamber 14. The standpipe 16 is formed by an inner wall 20 and an outer wall 22 to provide an annular channel 24. The outer wall 22 extends below the inner wall 20 and has a section 25 below the end of the inner wall where the inner surface converges to provide a nozzle 26 at the base of the central chamber 14.
Below the nozzle 26, the inner surface of the outer wall 22 diverges to form a water injection chamber 28. A second burst diaphragm 30 is disposed across the base of the water injection chamber 28. The wall of the water injection chamber 28 has a first group of injection apertures 31, best illustrated in the rollout view of FIG. 2, which are circumferentially-spaced around the chamber immediately below the nozzle 26. Thirty-eight apertures are provided in the preferred embodiment. In order to illustrate the vertical placement of the injection apertures in FIGS. 1 and 3, these Figs. show the injection apertures in a common vertical section rather than their actual azimuthal position as illustrated in FIG. 2.
The standpipe 16 is disposed within a housing 32 which forms a cooling chamber 34 around the standpipe. The annular channel 24 is in fluid communication with cooling chamber 34 through circumferentially-spaced apertures 36 in an annular baffle plate 38. The baffle plate 38 is joined to an annular flange 40 at the top of the inner wall 20 to form an annular chamber 42. The standpipe 16 and housing 32 are joined to the rocket motor 10 by suitable fastening means which are illustrated but are not numbered. The cooling chamber 34 extends to just below the first set of injection apertures 31 in the wall of the water injection chamber 28. The housing 32 has an inwardly extending flange 44 which is joined to an outwardly extending horizontal rib 46 of the outer wall 22 to form the bottom of the cooling chamber 34. The injection apertures 31 allow fluid communication between the bottom of the cooling chamber 34 and the water injection chamber 28.
The above-described structure is substantially the same as that employed in the prior missile eject system which the present invention is intended to modify. The improved missile eject system further includes additional injection apertures and valve assemblies for selectively controlling the injection of fluid through the additional apertures. Five groups of injection apertures, A1-A5, are disposed circumferentially in the wall of the water injection chamber 28 below the horizontal rib 46. As shown in FIG. 2, group A1 has 3 apertures, group A2 has 6 apertures, group A3 has 12 apertures, group A4 has 18 apertures, and group A5 has 21 apertures. Each group of injection apertures, A1-A5, is surrounded by the top horizontal rib 46, a bottom horizontal rib 48, and vertical ribs 50 which meet with the inwardly extending flange 44 to enclose the apertures. As best shown in FIGS. 3 and 4, the housing 32 below the cooling chamber 34 has five vertical bores 52 disposed circumferentially in the inwardly extending flange 44. The housing 32 additionally has five radial horizontal bores 54 which intersect the vertical bores 52 and provide a passage between each vertical bore and one group of injection apertures, A1-A5, to the injection chamber 28. O-ring seals 56 are provided to seal each group of apertures A1-A5 and its associated passage between the cooling chamber 34 and the injection chamber 28.
As shown in FIGS. 4 and 5, a rotary valve assembly V1-V5 is disposed in each vertical bore 52. The preferred valve assembly includes a cylindrical sleeve 58 having an outward flange 60 at the base for attaching the sleeve to the housing 32 and an inward flange 62 at the top for retaining a rotary valve element 64 in the sleeve. The sleeve has a circular opening 66 which communicates with the horizontal bore 54. The rotary element 64 is a cylinder having a curved channel 68 which provides a smooth fluid-flow path from the cooling chamber 34 to the horizontal bore 54 when the valve is open and closes this path when the rotary element is rotated 180° to the valve--closed position. The rotary element 64 has a slotted shaft 70 for mating with the drive shaft 72 of a rotary actuator 74. The rotary actuator 74, the cylindrical sleeve 58 and the rotary element 64 are secured in place by a mounting plate 76.
The preferred rotary actuator 74 is a permanent magnet D.C. motor having travel stops at open and closed positions. FIG. 6 illustrates a suitable control circuit with the control switches 51, 52, and 53 set to position the actuator 74 in the closed position. The housing 32 has an annular cavity 78 shown in FIG. 3 in which the rotary actuators 74 are disposed and which allows access to each valve assembly. FIG. 5 illustrates the positions of the rotary actuators 74 and the electrical cables 80 connected thereto in the housing 32.
The housing 32 is coupled at the base 82 to the missile launch tube 85 so that the output of the mixing chamber is directed into the launch tube. FIG. 7 shows the missile eject system coupled to a missile launch tube 85.
The operation of the improved missile eject system is illustrated in FIGS. 9a-9d. Prior to activation of the system as shown in FIG. 9a, the standpipe 16 and the cooling chamber 34 are filled with a cooling fluid, normally water, to a level near the top of the cooling chamber such as indicated by low full level 86 in FIG. 1. The lower burst diaphragm 30 seals the fluid in the standpipe 16 and the cooling chamber 34. The upper diaphragm 16 separates the rocket motor 10 from the cooling liquid.
When it is desired to eject the missile, the gas generator 10 is activated. The hot gas produced thereby bursts the upper diaphragm 18 and flows through nozzle 12 into the central chamber 14 of the standpipe 16, creating pressure on the surface of the cooling liquid within the central chamber 14 as illustrated in FIG. 9b. As soon as the pressure on the surface of the cooling liquid reaches the burst pressure of the lower diaphragm 30, the diaphragm ruptures and the cooling liquid within the central chamber 14 is ejected from the standpipe 16 through the lower nozzle 26 (see FIG. 9c). The nozzle 26 provides an increase in the flow velocity which decreases the pressure at the downstream side of the nozzle in the water injection chamber 28. The higher pressure above the nozzle 30 is transmitted through the annular channel 24 to the top of the liquid in the cooling chamber 34. The difference in pressure between the liquid in the cooling chamber 34 and the hot gas in the injection chamber 28 causes the liquid in the cooling chamber to be injected through the injection apertures to provide a metered injection of the cooling liquid into the hot gas in the injection chamber as shown in FIG. 9d. The water injection apertures provide that the cooling water injected into the hot gas at a controlled continuous rate. The injected water cools the hot gas so that the resulting gas/water/steam mixture which comes in contact with the missile nozzle 88 (see FIG. 7) is at a sufficiently low temperature so that it will not cause premature ignition of the missile propellant.
The present invention varies the eject energy applied at the missile by selectively varying the rate at which water from the cooling chamber 34 is injected into the hot gas flow from the rocket motor 10. As illustrated in FIG. 8, the maximum launch energy is provided when all the valves are closed so that water from cooling chamber 34 is injected into the hot gas only through the thirty-eight apertures in the first set of water injection apertures 31. The fact that the apertures 31 are always open ensures that sufficient water is injected into the hot gas to prevent the injection of gas into the launch tube at an excessively high temperature. The metered injection of additional cooling water through additional apertures reduces the energy imparted to the missile. As is apparent from FIG. 8, the position of the valves V1-V5 can be selected so that cooling liquid may be injected through from 3 to 60 (in steps of 3) additional injection apertures. The disclosed arrangement provides 21 different eject energies.
Prior to the launch, the position of the valves is selected to provide the best energy for the expected depth of launch. All valves are normally open to provide the minimum eject energy rather than the maximum energy in the event of a malfunction in the valve control system. For example, if fifteen additional injection apertures are desired, the valve element 60 of the valve assemblies associated with aperture group A1 aperture group A4, and aperture group A5 are rotated 180 degrees from the open position shown in FIG. 1 to the closed position. The valves associated with aperture groups A2 and A3 remain in the open position to allow the water to be injected from the cooling chamber 34 into the injection chamber 28 through the fifteen apertures in groups A2 and A3. After the rocket motor is ignited, the pressure differential between the water injection chamber 28 and the cooling chamber 34 causes the injection of the cooling fluid through the thirty-eight apertures which are always open and also through the fifteen apertures controlled by valves V1 and V3. The injection of the fluid cools the hot gas from the rocket motor 10 and reduces the pressure of the gas/liquid/steam mixture which is coupled to the missile launch tube.
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A variable energy missile eject system in which the rate at which cooling ter is injected into the hot gas flow from a solid propellant rocket motor may be varied to optimize the eject energy according to launch depth. A first set of injection apertures through which water is always injected provides the necessary cooling and establishes the minimum rate of water injection (maximum launch energy). Additional sets of injection apertures having varying numbers of apertures are individually controlled to allow the water injection rate to be increased by increasing the number of injection apertures.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a fishing lure and method of manufacturing of the same. In particular, the present invention relates to a fishing lure having elongated arms extending from the body of the fishing lure for attachment of spinning elements.
2. Summary of the Prior Art
Fishing lures with blades and other spinning elements attached are common in the art. These types of lures come in all different shapes, sizes, and configurations. Many such configurations disclose fishing lures with a hook extending from the tail-end of the body of the lure and a shank extending from the nose of the fishing lure with one or more spinning elements attached to the shank.
It is less common in the art to find fishing lures with spinning elements attached to arms extending from the sides of the body of the lure. However, such lures exist in the art. Examples of these types of lures include the following: U.S. Registration No. 1,923,840 and U.S. Registration No. 2,125,030 to Ozburn; U.S. Registration No. 3,996,688 to Hardwicke; U.S. Registration No. 4,884,358 to Grove; U.S. Registration No. 5,930,941 to Hayes; and U.S. Registration No. Des. 418,898 to Luckey.
The Ozburn patents disclose a lure with a body shaped like an insect, frog, or the like. A crossbar with eyelets at each end passes through the body of the lure such that the eyelets extend from each side of the body of the lure. A swinging lever with arms forming a W shape is mounted to the lure such that the arms pass through the eyelets on either side of the body of the lure. The arms extend backwards with swiveling blades attached to the arm's ends.
One embodiment of the Hardwicke patent reveals an angled wire that extends from the top of the lure with the swiveling blade attached at its distal end. The wire is imbedded in the body, which has a skirt attached to a sleeve that slips over the nose of the lure.
The Grove patent reveals a trio of spinners attached to wires extending from the body of the lure creating the appearance of a school of fish. One spinner is attached to an angled wire, which extends from the nose of the lure. Two other equal and opposite spinners are attached to wires that extend perpendicularly from the sides of the body at an upward angle.
The Hayes patent reveals a jig type lure. The lure body has deflectable arms, which extend from the sides of the lure body. The arms are stainless steel wire sufficiently stiff so they do not deflect when pulled through water, but also sufficiently flexible when engaged by the mouth of a fish. The wire ends are encapsulated within the lure body.
The Luckey design patent discloses a lure body with wires that extend from the sides of the lure body in a perpendicular manner. Additional wires are attached to each of the perpendicular wires at one end and swiveling blades are attached at the other end.
A patent to Miles, U.S. Registration No. 4,133,135, discloses a lure containing a body, skirt, a main wire extending from the nose of the body, two additional wires attached to the main wire at one end, and swiveling blades attached to the main wire at the other end.
A patent to Gentry, U.S. Registration No. 4,901,470, discloses a lure body having a skirt and bill that extends from the nose of the lure body. A cable wire with an attached spinner blade extends into the lure body through the head of the wire and an opening in the bill. The end of the cable wire is imbedded in the lure body. The cable wire is surrounded by a spring, which is partially imbedded in the lure body.
The present invention is different than the prior art. First, the prior art patents reveal rigid arms. The present invention describes both rigid and flexible wire arms and the advantages of the flexibility. Second, the wire arms of the prior art patents are imbedded within the lure body when the body of the lure is formed. In the present invention, the wire arms are attached by inserting them into tubular sleeves extending from the lure body. The lure body is formed first and the wire arms are attached afterwards. This invention is an improvement over prior art lures because it allows for the attachment of arms to the lure after the lure body has been formed and thereby allows for the selection of arms with different lengths and rigidity.
This invention also allows for a more efficient method of manufacture because the wire arms are inserted after the lure bodies are formed. The wire arms do not take up space in the mold forming piece during the forming process. Thus, more lure bodies can be formed with one mold forming piece.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a novel fishing lure containing elongated arms extending from sleeves secured into an openings on the lure body.
It is another object of the present invention to provide a novel fishing lure with crimped sleeves to secure the elongated arms within the sleeve.
It is another object of the present invention to provide arms that can be varied in length depending on the effect desired and can have spinners attached to attract fish.
It is another object of the present invention to provide a novel fishing lure with flexible elongated arms that bend when pulled through the water. The flexibility of the arms allows the lure to brush the bottom surface of a body of water without grabbing plants and debris. The flexibility also provides additional movement on the lure to attract fish.
It is another object of the present invention to provide a novel fishing lure with elongated arms extending from the lure body outwardly and backwardly.
It is another object of the present invention to provide a novel method of manufacturing the present invention using a mold forming piece. The mold forming piece contains impressions for the lure bodies, hooks, and shanks. Because the wire arms are added after the lures are created, space is not required for the lure arms in the mold forming pieces between each lure body impression. Therefore, more impressions can fit into one mold forming piece than current fishing lure manufacturing methods.
It is another object of the present invention to provide a novel method of manufacturing the present invention using a mold forming piece containing impressions for sleeves for insertion of elongated arms, which will extend from the lure body when formed.
It is another object of the present invention to provide a novel fishing lure that can be manufactured easily and inexpensively.
In satisfaction of these and related objectives, Applicant's present invention provides a fishing lure containing a body with a hook secured to the body. In the preferred embodiment, two sleeves are imbedded and extend from opposite sides of the body. Two elongated arms are inserted and secured within the sleeves and extend outwardly and backwardly from the lure body. Spinning elements are attached to the distal ends of the elongated arms. A wire shank extends from the lure body to which a spinning element is attached to the distal end of the wire shank. The preferred embodiment is manufactured using a novel method comprising insertion of liquefied lure body material into the mold cavities of a mold forming piece. While the mold forming piece is spun in a centrifuge device, sleeves, hooks and shanks are inserted into impressions in the mold cavities prior to pouring the liquefied lure body material. The liquefied material is allowed to cool and harden, thereby leaving the sleeves, hooks and shanks imbedded in and extending from the lure body.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the preferred embodiment.
FIG. 2 is a top view of the preferred embodiment.
FIG. 3A is a cross sectional view of the preferred embodiment along line 3 A— 3 A in the direction of the arrows in FIG. 2 .
FIG. 3B is a cross sectional view of the preferred embodiment along line 3 B— 3 B in the direction of the arrows in FIG. 2 .
FIG. 3C is a cross sectional view of the preferred embodiment along line 3 C— 3 C in the direction of the arrows in FIG. 2 .
FIG. 4 is a perspective view of the mold forming piece used to manufacture the preferred embodiment.
FIG. 5 is a top view of the lower portion of the mold forming piece used to manufacture the preferred embodiment.
FIG. 6 is a bottom view of the upper portion of the mold forming piece used to manufacture the preferred embodiment.
FIG. 7 is a cross section view of a mold cavity along lines 7 — 7 in FIG. 4 .
FIG. 8 is an enlarged partial top view of the lower portion of the mold forming piece used to manufacture the preferred embodiment depicting a mold impression of the lure body with hook and shank in place.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1 , the fishing lure 10 incorporates a body 12 having a head portion 14 and a tail portion 16 . A lip 17 extends from and around the circumference of the tail portion 16 . An elongated fin 18 protrudes from the top surface of the fishing lure and extends between the tail portion 16 and the head portion 14 .
In the preferred embodiment, the fishing lure 10 is in the shape of a small bait fish with an eye 19 painted on or otherwise attached to the body. However, it is anticipated that the body 12 may resemble other shapes such as insects or frogs, which may be attractive to fish. In addition, it is preferred that the body be formed of cast lead. However, other acceptable materials may be substituted.
Referring to FIGS. 1 and 2 , a shank 20 is embedded in and extends from the nose 22 of the body 12 of the fishing lure 10 . As shown in FIG. 1 , the shank 20 is bent to form a upper horizontal portion 24 , a looped portion 26 , a vertical portion 28 , and a lower horizontal portion 30 . The upper horizontal portion 24 extends from the nose 22 in a direction aligned with the body 12 of the fishing lure 10 . The looped portion 26 is a small U-shaped curvature of the shank 20 which loops 180 degrees underneath the upper horizontal portion 24 in the same vertical plane. The vertical portion 28 extends downwardly from the lower end of the looped portion 26 . The lower horizontal portion 30 extends from the lower end of the vertical portion 28 in a direction parallel to the upper horizontal portion 24 and inwardly generally toward the body 12 . Although, in the preferred embodiment, the shank 20 is bent as described herein, it is anticipated that numerous configurations and shapes of the shank are acceptable.
Still referring to FIGS. 1 and 2 , a propeller blade 32 , commonly known in the art as a buzzbait blade, is rotatably mounted on the lower horizontal portion 30 of the shank 20 . The propeller blade is positioned between a spacer 33 axially mounted to the lower horizontal portion 30 and end cap 34 axially mounted to the horizontal portion 30 toward its distal end 36 . The distal end 36 is bent slightly to prevent the end cap 34 from sliding off the lower horizontal portion 30 . Although the propeller blade 32 is utilized in the preferred embodiment, it is anticipated that other types of blades, such as spinnerbait blades, could be connected to or mounted on the shank 20 .
Referring to FIG. 1 , a hook 40 extends from the rearward tip 42 of the tail portion 16 of the body 12 . A skirt 44 with a plurality of streamers 46 is attached to the tail portion 16 and positioned such that the streamers 46 will trail behind the fishing lure 10 and hide the hook 40 as the fishing lure 10 is pulled through water. In the preferred embodiment, the skirt 44 is attached to the tail portion 16 between the lip 17 and the head portion 14 with a rubber band 48 . However, it is anticipated that other methods of attachment such as clipping or gluing are acceptable.
Referring to FIGS. 1 , 2 , and 3 A– 3 C, rearwardly angled opposing connector sleeves 50 a and 50 b are embedded in and extend from the opposing sides of the head portion 14 of the body 12 . Arms 52 a and 52 b are inserted into the connector sleeves 50 a and 50 b which are crimped around the arms 52 a and 52 b and thereby connecting and securing the arms 52 a and 52 b to the body 12 . In the preferred embodiment, the arms 52 a and 52 b are flexible surflon multistrand nylon coated steel leader wire. However, it is anticipated that other flexible material such as nylon monofilament or an inflexible material such as single strand fixed wire could be used.
As shown in FIG. 1 , spinner blades 54 a and 54 b are swivelly attached to the looped distal ends 56 a and 56 b of the arms 52 a and 52 b preferably with swivels 55 a and 55 b . Collars 58 a and 58 b are positioned around the looped distal ends 56 a and 56 b of the arms 52 a and 52 b . Collars 58 a and 58 b are flattened and pressed against the looped distal ends 56 a and 56 b to hold them in place. The collars 58 a and 58 b are positioned to leave the outermost portion of the looped distal ends 56 a and 56 b exposed.
Referring to FIG. 4 , in a preferred process for manufacturing the fishing lure 10 described herein, a plurality of fishing lures are cast in a silicone mold forming piece 60 in a manner common in the industry. The mold forming piece 60 is divided into a lower portion 61 and an upper portion 62 .
Referring to FIG. 5 , a plurality of individual lower mold impressions 64 in the shape of the right half of the fishing lure 10 are formed into the top surface 65 of the lower portion 61 of the mold forming piece 60 . The lower mold impressions 64 comprise lower lure body impressions 71 , lower hook impressions 70 , and lower shank impressions 72 ; which are positioned to correspond to the positions of the hook 40 , body 12 , and shank 20 of the fishing lure 10 as shown and described herein (See FIG. 1 ).
Referring to FIG. 6 , a plurality of individual upper mold impressions 66 in the shape of the left half of the fishing lure 10 (See FIG. 1 ) are formed into the bottom surface 67 of the upper portion 62 of the mold forming piece 60 . The upper mold impressions 66 comprise upper lure body impressions 85 , upper hook impressions 74 , and upper shank impressions 75 ; which are positioned to correspond to the positions of the hook 40 , body 12 , and shank 20 on the fishing lure 10 as shown and described herein (See FIG. 1 ).
As shown in FIG. 7 , when the upper portion 62 of the mold forming piece 60 is placed on top of the lower portion 61 , the plurality of lower mold impressions 64 mate with the corresponding plurality of upper mold impressions 66 forming a plurality of mold cavities 63 in the shape of the fishing lure 10 . FIG. 7 shows only a cross section of a single mold cavity 63 . However, it can be appreciated that a plurality of identical mold cavities 63 are formed.
Referring to FIGS. 5–8 , each of the lower mold impressions 64 and upper mold impressions 66 have respective sleeve impressions 68 a and 68 b that correspond to the positions of the connector sleeves 50 a and 50 b on the fishing lure 10 (See FIGS. 1 , 2 ). As shown in FIG. 8 , prior to placing the upper portion 62 of the mold forming piece 60 on the lower portion 61 , connector sleeves 50 a and 50 b are inserted into and extend out of the sleeve impressions 68 a and 68 b . ( FIG. 8 shows only the lower mold impression and, consequently, connector sleeve 50 b and sleeve impression 68 b corresponding to the upper mold impression are not shown.) At the same time, a plurality of hooks 40 and shanks 20 are placed in respective lower hook impressions 70 and lower shank impressions 72 . When the upper portion 62 of the mold forming piece 60 is then placed on top of the lower portion 61 , the hooks 40 and shanks 20 press into respective upper hook impressions 74 and upper shank impressions 75 . The hooks 40 , shanks 20 , and connector sleeves 50 are held in position in this manner during the preferred manufacturing process. FIG. 8 depicts only one of a plurality of lower mold impressions 64 .
Referring to FIGS. 5 , 6 , and 8 , first and second protrusions 76 a and 76 b and third and fourth protrusions 77 a and 77 b extend from the top surface 65 of the lower portion 61 of the mold forming piece 60 . First and second protrusions 76 a and 76 b are positioned at each side of each lower hook impression 70 and third and fourth protrusions 77 a and 77 b are positioned at each side of the lower shank impression 72 . The first and second protrusions 76 a and 76 b and third and fourth protrusions 77 a and 77 b serve to align and further secure the plurality of hooks 40 and shanks 20 when they are placed in the respective hook impressions 70 and shank impressions 72 . Corresponding first and second recesses 78 and 79 are formed in the bottom surface 67 of the upper portion 62 of the mold forming piece 60 . The first and second recesses 78 and 79 are positioned to accept the first and second protrusions 76 a and 76 b and third and fourth protrusions 77 a and 77 b , respectively, when the upper portion 62 of the mold forming piece 60 is placed on top of the lower portion 61 .
Referring to FIGS. 4–8 , once the hooks 40 , shanks 20 , and connector sleeves 50 a , 50 b are placed into the mold forming piece 60 , the upper portion 62 of the mold forming piece 60 is then placed on top of the lower portion 61 , as shown in FIG. 4 . The mold forming piece 60 is then placed in a centrifugal device (not shown) and spun about its axis 80 . A plurality of round headed screws 86 are screwed into and protrude from the bottom surface 67 of the upper portions 62 of the mold forming piece 60 (See FIG. 6 ). A plurality of corresponding screw head cavities 88 are position in the surface 65 of the lower portion 61 of the mold forming piece 60 to receive and mate with the round headed screws 86 . The mating of the round headed screws 86 and the screw head cavities 88 allow the upper portion 62 and the lower portion 61 of the mold forming piece 60 to remain in the same position relative to each other during the spinning process.
Still referring to FIGS. 4–8 , while the mold forming piece 60 is spinning, molten lead (not shown) is poured through a circular opening 81 centered in the upper portion 62 into a circular cavity 82 formed in the upper portion 62 and lower portion 61 . As the molten lead (not shown) is poured into the circular cavity 82 , it is slung into the plurality of mold cavities 63 through a plurality of channels 84 that extend from the circular cavity 82 to each mold cavity 63 . After the mold cavities 63 are filled, the spinning is stopped and the lead is allowed to cool and harden within the mold cavity 63 . Once hardened, the lead bodies 12 are removed from the mold cavities 63 with the hooks 40 , shanks 20 , and connector sleeves 50 imbedded in and extending from the body 12 of the fishing lure 10 in the manner described herein (See FIGS. 1 , 2 ).
As shown in FIGS. 3A–3C , arm 52 a is then inserted into connector sleeve 50 a . Sleeve 50 a is then crimped and pressed into the arm 52 a thereby holding it in place. FIGS. 3A–3C depict the cross-section of only one side of the head portion of the lure body 12 and thus depict one arm 50 a and connector sleeve 52 a . However, it can be appreciated that each fishing lure 10 has an identical and opposing arm 50 b and connector sleeve 52 b , which are connected in the identical manner.
Finally, the skirt 44 , swivels 55 a and 55 b , spinner blades 54 a and 54 b , and propeller blade 32 are attached in the manner described herein.
Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limited sense. Various modifications of the disclosed embodiments, as well as alternative embodiments of the inventions will become apparent to persons skilled in the art upon the reference to the description of the invention. It is, therefore, contemplated that the appended claims will cover such modifications that fall within the scope of the invention.
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The present invention provides a fishing lure containing a body with a hook secured to the body. The body contains two openings to secure two crimped sleeves into the opening. Two elongated arms are inserted and secured into the sleeves and extend outwardly and backwardly from the lure body. Spinning elements are attached to the distal ends of the elongated arms. A wire shank extends from the lure body to which a spinning element is attached to the distal end of the wire shank. The present invention is manufactured using a novel method comprising insertion of liquefied lure body material into the mold cavities of a mold forming piece, which contains impressions for the lure body, hooks, and sleeves. The mold forming piece is then spun in a centrifuge device.
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FIELD OF THE INVENTION
This invention relates to luminaires, and particularly to a luminaire which is especially suited for the interior illumination of parking structures.
BACKGROUND OF THE INVENTION
One consequence of urban growth is the need for parking structures. As the cost of land increases, single level parking lots at grade level become less affordable, and multiple-level parking garages become the rule. Expenses for this purpose are grudgingly allowed, and they have developed as minimal structures with little or no aesthetics. The ceiling clearances are low, often only 7 feet high, and obstructions by way of beams and columns further add to a feeling of oppressiveness. Adding to this the "Hollywood" concept of a parking structure where bad events occur in the shadows, many persons become uneasy when using these structures, especially at night.
Often, conventional industrial area, and street light fixtures are used to illuminate these structures. Because such fixtures are either very simplistic, or are designed for different applications, the consequence of their use is a structure which when illuminated has many shadows and dark regions. The place becomes something of a cave, and indeed lacks some features which whether they would make it a safer place or not, at least would make a person feel more secure and likelier to want to be there.
In addition, for safety's sake, it is better for the illumination means not to glare into the eyes of the driver. Such glare can reduce the sensitivity of the driver's eyes to persons or objects in the vehicle's path, and could lead to potentially dangerous circumstances. Where luminaires are used which are not properly cut off, such glare is regularly produced.
To complicate matters, a parking structure inherently involves two sets of requirements, whose objectives are quite different. Yet these ought to be met by a single luminaire to minimize expense and clutter.
A conventional parking structure includes a central driving lane from which parking stalls branch off, usually at an oblique angle, but sometimes at a right angle, on both sides of the driving lane. For the driving lane, the objectives are, or should be, to provide a brightly lighted path along the driving lane, without glare in the eyes of the driver. Thus a symmetrical illumination pattern along the driving lane is called for, together with a cutoff of light at an angle that is sufficiently low to keep direct rays out of the driver's eyes. Side illumination into the parking stalls is of lesser importance for this path.
For the parking stalls, the criteria are quite different. Here the concept of perception becomes significant. A woman approaching her car would like to look into its backseat and find it well-enough illuminated to see that it is safe. Also, there should be no more than minimal shadows around the front and sides of the car so the person is not fearful of what may be hidden at the front end of the car.
For the parking stalls, there is little interest in illumination along the driving lane, but there is much interest in illumination of the axes oblique to it. Thus, the extent of asymmetry in the direction of the driving lane and in the direction lateral to it should be quite different from one another.
In fact, downward illumination of the two regions not only requires asymmetry along a pair of obliquely related axes, but also in more than one horizontal plane. The control of a downwardly-directed pattern is a well-known objective in area and pattern lighting. For example, see Wayne W. Compton et al U.S. Pat. No. 4,041,306 wherein illumination of specific sidewalk areas, and cut off of glare light, are objectives. However, the use of luminaires of this general class, while very adequate to direct light onto the ground in a specific pattern, attend primarily to downward illumination of the type used to light sidewalks and parks. The more sophisticated luminaires of this class are also concerned with cut off to reduce glare and visual pollution by glare light. While they do these well, their design frustrates the general type of three dimensional space illumination which is also needed to meet the objectives of this invention.
In order to provide for a feeling of security, as well as to provide illumination which reduces shadows and dark places, there is also needed a generally upward illumination that does not glare at the drivers, and that reaches well beyond the limits of the downwardly beamed light.
Along the driving lane, a generally diffuse beam directed toward the ceiling is useful for this purpose. Along the parking stalls, a more clearly regulated beam is directed toward the farther end of the stalls, together with a substantial illumination of the ceiling. These provide a substantial "volumetric" illumination along the parking stalls by both light reflected from the ceiling, and directed light.
Because of space and expense limitations, these features must all be provided in one luminaire, and this invention accomplishes that objective.
BRIEF DESCRIPTION OF THE INVENTION
A luminaire according to this invention has a vertical reference axis, a horizontal driving lane axis, and a horizontal parking stall axis. This system defines the orientation of the luminaire in space. It will generally be mounted to the ceiling with the reference axis vertically aligned and the driving lane axis parallel to a lane along which a vehicle will be driven. The parking stall axis will extend away from the driving lane axis. The driving lane axis and the parking stall axis will usually be normal to one another, because the luminaire will then best fit the largest number of installations. However, if preferred, these axes can be disposed at a different angle, such as the angle which the parking stall makes with the driving lane if it is other than normal. This will rarely provide enough advantage to justify making the luminaire in different configurations for that purpose alone.
The luminaire has socket means for a conventional luminaire lamp, disposed on its central, vertical axis. It is encircled by a peripheral reflecting band having an upper edge and a lower edge. A transparent window closes the luminaire at the lower edge. Downward light from the lamp directly through the window illuminates a substantial, generally circular area beneath the luminaire.
The lower edge acts as a cut off for light reflected from the reflecting band. The band is gently curved so that the increased area of pavement illumination provided by the reflected light can be made more uniform. According to a preferred but optional feature of this invention, the reflecting surface of the band is pleated so the light is not reflected directly back through the arc tube of the lamp itself. Light reflected through the lamp causes increased heating of the lamp, and shortens its life.
The features described this far will produce a circular pattern with a cutoff, usually about 72 degrees up from the vertical, suitable for the driving lane. Asymmetry is provided through a transparent peripheral band above the reflecting band and also generally above the lamp itself, by direct or refracted transmission of light directly from the lamp, and also from a top reflector. The light emanating from the transparent band is derived from upwardly directed rays from the lamp. Therefore, it is useful for ceiling illumination, and is also amenable to being directed variably as respects the driving lane axis and the parking stall axis, so as to provide asymmetry respective to each of them without objectionable glare or wastage of light.
According to a preferred feature of the invention, the transparent band is provided with refractive prisms in areas where light is directed along the parking stall axis. This prismatic transmission enables a longer throw than the lower cutoff edge, and because it is directed away from the driving lane, it does not cause glare to the driver. It does, however, illuminate both the ceiling and the parking stalls.
According to yet another preferred feature of the invention, the top reflector includes both specular regions providing strong directionality to the light it reflects, toward the parking stalls, and diffusing regions which diffuse the light it reflects toward the driving lane, thereby to avoid glare to the driver, but still generally above the driver's eyes. This provides general illumination which is supplemented by light passing through the transparent portion without refracting prisms, to directly light the ceiling along the driving lane axis.
The resulting asymmetry is such that there is a substantially greater throw of light along the parking stall axis, than along the driving lane axis, with improved lighting for parking purposes, and glare-free lighting for the driving lane.
This invention will be fully understood from the following detailed description and the accompanying drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an upward view into the bottom of the luminaire;
FIG. 2 is a cross-section, partially in schematic notation, taken at line 2--2 in FIG. 1, showing the parking stall provisions;
FIG. 3 is a cross-section, partially in schematic notation, taken at line 3--3 in FIG. 1, showing the driving lane provisions;
FIG. 4 is a schematic elevation taken along the driving lane axis;
FIG. 5 is a schematic elevation taken along the parking stall axis; and
FIG. 6 is a schematic view of the luminaire's pattern, showing the asymmetry of the luminaire on the two horizontal axes.
DETAILED DESCRIPTION OF THE INVENTION
The presently-preferred embodiment of a luminaire 10 according to this invention is shown in FIGS. 1 and 2. As shown in FIG. 1 it is a circular structure having an upper end 11 and a lower end 12. Because its pattern of emitted light is asymmetrical, three intersecting axes are required to define it. Vertical axis 15 is a central axis, and is denoted as vertical, because the emitted light pattern is defined relative to a horizontal ceiling 16 and horizontal pavements 17, as shown in FIGS. 4 and 5.
The luminaire is intended to provide its light pattern relative to a driving lane axis 18 and a parking stall axis 19. For convenience these axes are shown normal to one another, although it will be recognized that axes 18 and 19 could be disposed at some other non-parallel relationship if preferred. For example, the angle could be selected to conform to the angle which the parking stalls make with the driving lane if other than 90 degrees. Often this angle is 90 degrees, but very frequently it is a different angle instead.
It is not necessary that the parking stall axis of the luminaire coincide with the axis of the parking slots, although such a relationship is useful. Instead, for purposes of economical distribution and manufacture of the product, orthogonal relationships will usually be provided. Even when the parking stalls are not normal to the driving lanes, this relationship is very useful. Therefore the terms of definition are not limiting in the sense that the parking stall axis must be positioned so it is parallel to the stall.
The upper end of the luminaire comprises a base 25 with provisions (not shown) to mount it to supporting structures such as the ceiling or a supporting pendant or post, and includes electrical connection means to connect a socket 26 to a source of power. The socket receives a lamp 27 such as a high intensity sodium or mercury type, or even a conventional incandescent lamp. Although some lamps have arc tubes with substantial axial lengths along which light is emitted, for the purposes of this disclosure they will be generally treated as a point source. Persons skilled in the art will recognize the difference between the theoretical treatment of exemplary light rays and the actual emissions of a light source of substantial length and area.
The upper portion 30 of the base is opaque. Usually it will be a metal structure containing circuit interface elements. The body of the luminaire is hollow, and its lower end is closed by a transparent closure 31. The closure is held in place by a rim 32.
A peripheral reflecting band 35 extends around the central axis. It is not transparent, and has an inside surface 36 that is gently curved in vertical planes which include the central axis. Its range of elevation approximately conforms to the range of elevation of the active portions of the lamp. The inside surface 36 of band 35 is reflective and pleated along the vertical axis. Thus, as best shown in FIG. 1, it constitutes a series of bent dihedral angles such as angle 38 with reflecting faces 39, 40. The purpose of these faces is to reflect the light in such a way that it does not pass through the arc tube of the lamp. This greatly extends the life of the lamp and lowers its operating temperature. Because the reflected pattern from this arrangement is symmetrical, the emission from the luminaire is also symmetrical, as to these elements.
Light reflected from the reflecting band is intended to light the pavement. These emissions are all symmetrical around the central axis. They combine with rays which pass directly from the lamp to the pavement, together to illuminate a circle 41 (FIG. 6).
The direct downward rays do not glare into the eyes of a driver. The reflecting band is so disposed and arranged that its reflected rays do not do so, either. For example, in FIG. 2, which shows rays on the parking stall axis, and in FIG. 3 which shows rays on the driving lane axis, see limiting ray 42 directly from the lamp, which along both axes grazes the lower, cutoff edge of the luminaire. Ray 42 is a limiting cutoff ray from the lamp and preferably makes an angle of about 72 degrees with the vertical.
Rays 43 in both FIGS. 2 and 3 impinge on the reflecting band near its lower cutoff edge, and is reflected as limiting ray 44, less than about 72 degrees, but preferably near to it. As can be seen from an examination of exemplary rays 45, 46 and 47, all reflected rays within the limits of the lamp length and the height of the reflecting band, exit the luminaire at lesser angles to the vertical.
Thus, as to the driver no ray which exits the lower end of the luminaire is less favorable than ray 42. In a conventional structure with a relatively low ceiling, in which a conventional automobile is driven along the driving lane, the driver's eyes will be above the limiting rays 42, so there is no glare from the luminaire.
As to the parking stalls, and the light emitted from the lower end, there is no problem of glare, because the driver is always facing away from the luminaire. The various downwardly directed rays which pass out of the lower end of the luminaire in FIG. 2, which is a section along the parking stall axis, will be recognized as identical to those in FIG. 2. In this sense, the rays emitted downwardly are symetrical around the central axis.
The asymmetry of the invention therefore relates to the upwardly directed rays, which are prevented by the reflecting band from exiting at an angle above about 72 degrees. It is these upward rays which provide the asymmetry, and the singular advantages along both of the horizontal axes. These objectives are attained by a refractive effect on the parking stall axis, which is not provided on the driving lane axis.
As a further but optional feature, an upper element 50 can be provided with a different reflecting function for each of the two horizontal axes. Element 50 is a concave surface of revolution 51 with a geometric line generator rotated around the central axis. As best shown in FIG. 1, it is divided into four quadrants or sectors 52, 53, 54, 55. Quadrants 53 and 55 are specularly reflective. Quadrants 52 and 54 are diffusely reflective.
Quadrants 52 and 54, which are diffusely reflective, are related axially to the driving lane axis (see FIG. 3). Rays such as exemplary ray 56 impinge on these surfaces, and are generally reflected as a diffuse family of rays 57 at a rather high angle, generally greater than about 85 degrees, so as to provide illumination to the ceiling and adjacent beams and also general area illumination in the structure above the vehicles. Direct upward rays 58 from the lamp illuminate the ceiling.
All of these rays pass through respective transparent regions 60, 61 of the transparent band, formed by two generally parallel surfaces. Thus, along the driving lane axis the upper rays light the ceiling and the general volume, and are generally above the driver. In case they are not, the diffuse quality of quadrants 52 and 54 prevents the existence of a brilliant spot of light. Instead there is a diffuse, wide light source of considerably limited intensity. The inverse curvature of the quadrant surfaces further limits the generation of a brilliant spot.
The objectives for the parking stalls are quite different. These are to illuminate the stalls ahead of the parked vehicles and to provide downward light to illuminate the interior of the vehicles and fill in between vehicles. This is in addition to illuminating the ceiling and providing a good general volumetric lighting effect.
FIG. 2, which is an axial section along the parking stall axis, shows that specularly reflecting quadrants 53 and 55 reflect upwardly directed rays from the lamp which impinge on them generally laterally toward refractive regions 65, 66 on the peripheral transparent band above the reflecting band.
The refractive regions are formed by a sawtooth pattern on the inside surface, and over the vertical extent of rays which are reflected from the quadrants. Exemplary reflected rays 67 will be refracted as a family of rays 68, 69 which are downwardly directed, at an angle well above 72 degrees so as to be projected farther from the luminaire than the rays which are emitted from the bottom of the luminaire. As a consequence, there is a longer throw, as shown in FIG. 5. This tends to illuminate the top and hood of the vehicle, and the wall ahead of it, thereby reducing shadows in the region ahead of the vehicle.
In addition, upwardly directed light, exemplified by rays 70, impinge directly on the refractors. These are also refracted but exit as a family of rays 71, 72 at an elevated angle, but which will be projected farther away from the luminaire than if they had instead passed through a smooth transparent body. This light will illuminate the ceiling farther from the luminaire, and will be bounced back from the ceiling at the front end of the vehicle, additionally to illuminate that region, and further reduce the shadows between vehicles.
FIG. 3 shows that rays 73 can pass directly through smooth regions 60 and 61 nearer to the luminaire, where the ceiling illumination nearer the luminaire will improve the general illumination along the driving lane.
The consequence of the foregoing is best shown in FIG. 6, which schematically shows the total pattern of illumination viewed from above.
Circle 41 is the limit of the downward illumination along both axes. Along the driving lane axis, its segments 81, 82 represent the farthest throw caused by direct transmission and reflection, emitted from the bottom of the luminaire.
The upwardly transmitted rays through segments 60 and 61 are generally similiarly projected. The diffused rays from the diffused segments 52 and 54 are not shown, because they contribute to general illumination, rather than to a pattern.
The farther extent of projection of light along the parking stall axis is shown by line segments 85 and 86. This primarily shows the light which is refracted downwardly. Again the light projected or emitted at the ceiling and at the forward wall is ignored in this diagram, because it relates to general illumination. However, the refraction exemplified by rays 87 toward the ceiling is along the parking stall axis farther than the diffuse emmission along the driving lane axis.
Accordingly, the driving lane receives light from the bottom of the luminaire which is well-distributed and cut off to avoid glare. In addition, the ceiling is directly illuminated, and there is also a source of diffuse illumination--from the diffuse quadrants 52 and 54.
The parking stalls receive the same downward light from the bottom end of the luminaire. There is a longer throw of upper light downwardly, and a more intense illumination of the ceiling and front wall.
As a consequence, a single luminaire is provided which presents a well-lighted path to the driver, and a well-illuminated stall, both when unoccupied by a vehicle and when occupied by a vehicle. The general region is well-lighted, sufficient stray light is available to enable vehicles and pedestrians to be seen, and foreboding shadows are reduced or illuminated.
This luminate is readily constructed mostly from molded parts, and is compatible in appearance with the most artistic surroundings.
Its effective use of light can enable a reduced number of luminaires to be used. In a parking structure the pedestrian sees a gentle illumination with only minimal bright spots. The lighting effect is both efficient and agreeable.
This invention is not to be limited by the embodiments shown in the drawings and described in the description, which are given by way of example and not of limitation, but only in accordance with the scope of the appended claims.
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A luminaire for use in parking garages having a vertical reference axis, a horizontal driving lane axis, and a horizontal parking stall axis. The resulting asymmetry is such that there is a substantially greater throw of light along the parking stall axis than along the driving lane axis, with improved lighting for parking purposes, and glare free lighting for the driving lane.
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This is a division of application Ser. No. 08/673,402, filed Jun. 28, 1996, now U.S. Pat. No. 5,789,467.
BACKGROUND OF THE INVENTION
In the history of making beverages (e.g. beer, wine, etc.) involving fermentation, many techniques have been used to improve the quality of the resulting product with respect to flavor and appearance. With the use of mass production techniques, additional concerns arise such as shelf life of the resulting product and product throughput in the manufacturing facility. Similar concerns often arise with respect to other beverages derived from fruit (e.g. apple juice).
Chill haze is often a major problem that occurs in these various beverages. Chill haze is caused by certain proteins and polyphenolic compounds which are present in the beverage. With the time delay between manufacture and consumption of mass produced beverages and the consumption of beverages in a chilled state, the development of turbidity or chill haze is exacerbated.
To avoid chill haze problems in the resulting product, beverages are typically treated (chillproofed) to remove at least a portion of the proteins and polyphenolic compounds responsible for the problem. Unfortunately, it is often difficult to remove the problematic proteins without removing other constituents which are responsible for favorable properties (e.g. flavor, foam retention, etc.) Chillproofing is made more difficult by the desire (and often the need) to avoid addition of chemicals to the beverage. Food purity law and general health concerns may arise whenever auxiliary chemicals are used in beverage manufacture.
Tannins are known chillproofing agents for beer. In some instances, tannin has been used to influence the flavor of the resulting beverage (e.g., in the making of various wines). Tannin interacts very effectively with the proteins responsible for chill haze to create a voluminous precipitate which is then removed from the beverage by filtration or decantation. Unfortunately, removal of the formed precipitate is often difficult, requiring long settling time or very slow filtration. The presence of residual tannins in the beverage may have undesired effects on the beverage flavor.
Porous adsorbents such as silica gels have also been widely used for chillproofing whereby the proteins are adsorbed and removed from the beverage by filtration or decantation. While many silicas provide adequate chillproofing performance, there is a desire to achieve better performance, especially for high volume throughput brewery operations. Typically, silicas do not chillproof as well as tannins, but they are more easily removed from the beverage by filtration compared to tannin.
Some attempts have been made in the prior art to immobilize tannin on support particles such as silica particles by use of chemical bonding agents. In U.S. Pat. No. 4,500,554, tannic acid derivatives were immobilized on a treated silica support using chemicals such as aminopropyltriethoxysilanes and sodium periodate or formaldehyde. Unfortunately, such chemical immobilization has disadvantages in that the immobilization process is expensive and that the added chemicals may present food purity issues. Techniques using formaldehyde are generally ineffective for immobilization of the type of tannin most preferred for use in beer chillproofing.
Thus, there is a need for tannin-containing compositions that do not possess the filtration problems of conventional tannins nor the problems of known immobilized tannins.
SUMMARY OF THE INVENTION
The invention provides crosslinked tannin/inorganic oxide composite particles which provide tannin functionality for all varieties of tannins without the filtration problems associated with ordinary tannins. The compositions of the invention are enabled by the use of epoxy crosslinking.
In one aspect, the invention encompasses a particulate composition comprising a composite of epoxy-polymerized tannin on inorganic oxide particles. The inorganic oxide preferably includes silica. The crosslinking agent is preferably a water-soluble diglycidyl ether.
In another aspect, the invention encompasses a method of chillproofing (protein removal from) beverages, the method comprising contacting the beverage with a particulate composition comprising a composite of epoxy-polymerized tannin on inorganic oxide particles whereby proteins are adsorbed by the composite particles, and thereafter removing the composite particles and adsorbed proteins from the beverage. Preferably, the beverage is contacted with an admixture of siliceous oxide particles with the epoxy-polymerized tannin-inorganic oxide composite particles. The method of the invention is especially useful in the chillproofing of plant-derived beverages (e.g. beer, juice, etc.).
The invention encompasses methods for making the epoxy-polymerized tannin-inorganic oxide particles of the invention. These and other aspects of the invention will be described in further detail below.
DETAILED DESCRIPTION OF THE INVENTION
The invention provides epoxy-polymerized tannin/inorganic oxide composite particles and compositions containing these composite particles. The composite particles of the invention are preferably further characterized by the absence of auxiliary chemicals adapted to bond the tannin to the inorganic oxide particles. The composite particles of the invention are preferably useful for treating beverages to provide the protein-removal benefits associated with the use of conventional tannins.
The tannin may be any known tannin material. Tannins typically contain one or more compounds selected from the group consisting of tannic acid, gallotannic acid, glucoside of tannic acid, glucoside of gallotannic acid, and mixtures thereof. Naturally-derived tannins are typically identified by the source plant (e.g., red oak tannin or sumac tannin) and/or their location of origin (e.g., Chinese galls or Bengal kino). If desired, mixtures of tannins may be used. Preferably, the tannin is one which is commonly used in the beer brewing industry (e.g. Brewtan®-Brewtan®C tannin sold by Omnichem N.V.). Brewtan® tannin is not readily polymerizable with formaldehyde due to the lower reactivity of the polyhydroxyaromatic rings (of these tannins) towards formaldehyde.
The crosslinking agent is preferably a polyepoxy compound containing at least two epoxide groups. The polyepoxy compound is preferably water-soluble. Epoxy compounds found to be particularly useful in the present invention are diepoxy compounds. A preferred diepoxy compound is 1,4-butanediol diglycidyl ether.
The amount of crosslinking agent used to polymerize the tannin maybe varied considerably. Preferably, the amount of crosslinking agent is sufficient to render the polymerized tannin insoluble in water. Preferably, the amount of crosslinking agent used is about 10-60 wt. % based on the weight of the tannin, more preferably about 20-40 wt. %.
The inorganic oxide particles may be of any type of inorganic oxide such as silica, alumina, silica aluminas, aluminosilicates, clays, acid-treated clays, alkaline earth silicates, etc. The inorganic oxide may be crystalline or amorphous. Preferably, silica is a preferred inorganic oxide. Where the compositions of the invention are to be used for chillproofing, the inorganic oxide particles are preferably of a type known to be suitable for chillproofing (preferably silica-containing particles). The inorganic oxide particles are preferably porous.
Where silica-containing particles are used as the inorganic oxide, they preferably contain amorphous silica; more preferably the silica-containing particles consist essentially of amorphous silica. Preferred amorphous silicas are those selected from the group consisting of silica gel, precipitated silica, and mixtures thereof. Preferred silica gels are selected from the group consisting of silica hydrogels, silica xerogels, and mixtures thereof. Where the starting inorganic oxide particles have significant water content (e.g. hydrogels), the process of forming the tannin/inorganic oxide composite of the invention will generally result in water removal from the particles.
The particle size distribution, porosity and surface area characteristics of the inorganic oxide particles may be varied as desired. Where the compositions of the invention are to be used for chillproofing, the physical characteristics of the inorganic oxide particles preferably correspond to those known to be especially suitable for chillproofing. Preferably, the size of the inorganic oxide particles is not so fine as to cause filtration problems when using liquid contacting applications (e.g. chillproofing). In general, the particles preferably have an average particle size of about 4-20 μm, more preferably about 7-15 μm. The inorganic oxide particles preferably have a pore volume of at least about 0.5 cc/g in the absence of the added tannin, more preferably about 0.7-1.2 cc/g. The inorganic oxide particles preferably have a surface area of at least about 250 m 2 /g in the absence of the added tannin, more preferably about 300-800 m 2 /g. An average pore diameter of the inorganic oxide particles can be calculated from the surface area and pore volume of the particles. The average pore diameter for the inorganic oxide particles is preferably at least 3 nm. The measurement of porosity and surface area is preferably done after first removing the tannin from the inorganic oxide particles by dissolution. The porosity and surface area associated with the inorganic oxide particles can then be determined by conventional techniques (e.g., N 2 -BET method).
The amount of tannin contained in the composite particles can be varied considerably. The compositions preferably contain at least about 1 part by weight tannin per 100 parts by weight of inorganic oxide, more preferably about 3-35 parts by weight tannin. The water content of the composite particles is preferably about 5 to 30 wt. %.
If desired, the tannin composites of the invention may be used in combination (admixture) with other known chillproofing agents such as silica gels (xerogels or hydrogels) or magnesium silicates. A preferred chillproofing agents for this purpose are Daraclar®7500 (Grace Davison). Where such an admixture is used, the weight ratio of the tannin composite to the other chillproofing agent is preferably about 1-5:5-1, more preferably about 1:1.
The epoxy-polymerized tannin/inorganic oxide composite particles of the invention are characterized in part by the fact that the aqueous dissolution rate of the polymerized tannin is extremely low, if not zero. The dissolution rate is preferably measured in deionized water at 20° C. where the amount of tannin in the test is about 200 mg/L of water. The dissolution test uses the ASBC method for measurement of total polyphenols adapted for measurement of tannin by calibration with standard solutions of tannin.
The compositions of the invention typically exhibit good filtration characteristics in comparison to uncomposited tannin. Use of tannin alone in beverage applications typically results in blockage of filters; physical admixtures of tannin and inorganic oxide result in slow filtration. The tannin-inorganic oxide composites of the invention preferably result in filtration rates comparable to those of the inorganic oxide particles themselves.
The epoxy-polymerized tannin-inorganic oxide composites of the invention can be manufactured by a variety of techniques. Preferably, the manufacturing technique avoids the use of non-aqueous solvents. In a preferred method, the tannin and epoxy crosslinking agent are first dissolved in water with adjustment of the pH to about 9-10. The resulting solution is then impregnated onto the inorganic oxide, preferably to the point of incipient wetness. The impregnated inorganic oxide is then heated to about 150-180° C. for a time sufficient to effect the tannin-epoxy crosslinking reaction. The resulting composite is then washed and dried.
The compositions of the invention are especially useful for chillproofing beverages. Most preferably, the compositions of the invention are used to chillproof fermented beverages such as beer. For chillproofing, the composite particles of the invention may be used at any point in the beverage manufacturing process where it is known to add tannin and/or inorganic oxide particles. For fermented beverages, the compositions of the invention are preferably added after fermentation. The dosage of the invention composition may depend on the desired degree of chillproofing and/or the particular beverage manufacturing process.
The compositions of the invention provide a combination of good chillproofing and filtration properties. These and other aspects of the invention are further illustrated by the following examples.
EXAMPLE 1
0.1427 g tannin was dissolved in 3.9 ml deionized water. 3.6 ml of 0.2N NaOH was added to raise the pH to about 9.5. 0.0838 g of 1,4 butanediol diglycidyl ether (BDE) was added to the solution. The resulting solution was then impregnated onto silica xerogel particles to the point of incipient wetness. The impregnated particles were then heated to 160° C. for about 2 hours to crosslink the tannin. The resulting composite was then washed with water and vacuum dried.
EXAMPLES 2 AND 3
The process of example 1 was repeated with 0.0204 g BDE for example 2 and 0.0102 g BDE for example 3.
EXAMPLE 4
The chillproofing performance of the materials of examples 1-3 was tested using neat samples of the materials. Samples of the silica gel (Daraclar®7500) were also tested alone for comparison. The samples were contacted with a beer A after maturation at the dosages described in Table 1. All samples were filtered through a diatomaceous earth coated filter, carbonated, bottled and pasteurized. The samples were then held at 38° C. for 6 days and then for two days at 2° C. The level of chill haze was measured in nephelometer turbidity units (NTU).
TABLE 1______________________________________Material Dose (g/hl) Haze (NTU)______________________________________Example 1 60 4Example 2 60 5Example 3 60 2Silica gel 60 6______________________________________
EXAMPLE 5
Admixtures of a polymerized tannin composite containing 3 wt. % tannin (prepared according to example 1 with a weight ratio of tannin/BDE of 3:1) with a silica gel chillproofing agent (DARACLAR®7500) were tested for chillproofing performance using the procedure of example 4 using beer B. The results, including comparison with the silica gel alone, are shown in Table 2.
TABLE 2______________________________________Material Dose (g/hl) Haze (NTU)______________________________________Silica gel 60 8Silica gel + tannin composite 40 + 20 6Silica gel + tannin composite 30 + 30 4Silica gel + tannin composite 20 + 40 6______________________________________
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Epoxy-polymerized tannin/inorganic oxide composite particles are obtained by polymerizing the tannin with a polyepoxy crosslinking agent in situ on inorganic oxide particles. The compositions of the invention are capable of achieving the performance of tannin in beverage treatment applications without tannin's associated filtration disadvantages.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a hydraulic pressure reservoir having at least one pressure chamber that is formed between two opposed, movable boundary surfaces, each of which includes a spring cover, a diaphragm spring, and at least one free-standing boundary surface.
[0003] 2. Description of the Related Art
[0004] A hydraulic pressure reservoir of this general type is known from International Published Application No. WO 2007/000128 A1. That publication discloses a spring-pressurized reservoir in which two diaphragm springs are clamped between two housing covers that are screwed to control plates.
[0005] A disadvantage of a hydraulic pressure reservoir in accordance with the existing art is the comparatively complex screwed connection, which in addition must be able to withstand very high tensile forces acting on the screws.
[0006] An object of the present invention is therefore to provide a hydraulic pressure reservoir of the above-indicated type that is simpler and less expensive to produce.
SUMMARY OF THE INVENTION
[0007] The object is achieved by a hydraulic pressure reservoir having at least one pressure chamber that is formed between two opposed, movable boundary surfaces. Each boundary surface includes a spring cover and a diaphragm spring, as well as at least one fixed boundary surface, where the fixed boundary surface over at least part of its periphery is a solid of revolution of a U-shaped cross section as the generating curve, and which fixes the diaphragm springs in the axial direction. The fixed boundary surface is thus cylindrical in shape over part of its axial extent, and includes regions at the end faces of the cylinder with which the outer perimeter of the diaphragm springs in the axial direction is fixed. To that end, it is preferably provided that the fixed boundary surface is a housing ring having a U-shaped cross section. That makes it possible to construct the pressure reservoir without screws that are loaded in the pressure direction of the diaphragm springs, as is required in the known devices.
[0008] The fixed boundary surface is constructed approximately like a steel strip that is bent at the top and bottom and is laid around the set of diaphragm springs. Preferably, the design also provides that the housing ring is in two parts, wherein the housing ring preferably includes two half-rings that are furthermore preferably divided by a plane that passes through the axis of rotation of the solid of revolution. The half-rings are preferably identical in construction.
[0009] To install the half-rings, they are placed around the pre-assembled spring set of the diaphragm springs that include spring covers, and are joined to each other. The connection is under load only in the circumferential direction of the solid of revolution. Forces that arise in the axial direction are absorbed by the housing ring itself.
[0010] The two half-rings are preferably joined together in a positive connection. The positive connection is preferably a dovetail joint. A connection of that type can be produced easily when manufacturing the half-rings, for example by stamping, and in addition is easy to assemble. The dovetail connection can be made by simply bending the half-rings upward slightly and sliding one over the other during assembly, and is self-locking thereafter. The dovetail joint preferably includes a dovetail on one of the half-rings and a correspondingly shaped recess on the other of the half-rings. Alternatively, it is also possible to provide dovetails and recesses one above the other in the axial direction on each end of the half-rings. The dovetail joint preferably includes means that fix the dovetail joint positively in the radial direction.
[0011] Once the connection has been made between the two half-rings, the axial compression force exerted by the diaphragm springs ensures that a tensile force arises in the circumferential direction of the half-rings, which fixes and locks the dovetail connection. To that end, lugs or projections or the like can be provided, for example on the dovetails, which prevent the dovetails from being pressed clear through the recesses. In that way the connection of the two half-rings is self-locking.
[0012] In another preferred exemplary embodiment of the invention, the housing ring can also be designed in three parts. If it is then divided into three parts in a plane in which the angle of rotation of the housing ring is situated, the housing ring includes three 120° ring segments.
[0013] In addition to the above-described joinder of the housing ring parts by means of a dovetail joint, the two-part or multi-part housing ring segments can also abut each other without a positive lock, in which case the connection is supported by means of a band or ring that surrounds the ring segments to secure them radially. Of course, a plurality of circumferential bands or tensioning rings can also be provided.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The structure, operation, and advantages of the present invention will become further apparent upon consideration of the following description, taken in conjunction with the accompanying drawings in which:
[0015] FIG. 1 is a longitudinal cross section through an exemplary embodiment of a pressure reservoir in accordance with the invention;
[0016] FIG. 2 is a perspective view of a two-piece housing ring of the pressure reservoir shown in FIG. 1 ;
[0017] FIG. 3 is a representation of the pressure conditions of the pressure reservoir shown in FIG. 1 ;
[0018] FIG. 4 is a cross-sectional view similar to FIG. 1 of an exemplary embodiment of a system of sensors within the pressure reservoir.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] FIG. 1 shows an exemplary embodiment of a pressure reservoir in cross section. The illustrated reservoir includes a housing ring 4 , which is an essentially U-shaped profile from which a solid of revolution in accordance with FIG. 2 is formed. The housing ring 4 encircles two diaphragm springs 8 and 9 , which press two spring covers 6 and 7 in the direction of a pressure chamber 10 . An upper diaphragm spring 8 interacts with an upper spring cover 6 and, correspondingly, a lower diaphragm spring 9 interacts with a lower spring cover 7 . Upper spring cover 6 and lower spring cover 7 are identical in construction; correspondingly, upper diaphragm spring 8 and lower diaphragm spring 9 are identical in construction. In the following explanation, the construction of the spring covers and diaphragm springs will therefore be described only on the basis of upper diaphragm spring 8 and upper spring cover 6 .
[0020] Spring cover 6 includes two adjacent annular grooves in its radially outer region, namely an inner annular groove 11 that has an essentially rectangular cross section, and an outer annular groove 12 that has an essentially rectangular cross section in its radially inner area and which changes to a trapezoidal region with a stop 23 radially toward the outside. Inner annular groove 11 receives a cover-mounted pivot ring 13 , and outer annular groove 12 receives a cover-mounted sealing ring 14 . Diaphragm spring 8 is supported on the housing side on a housing-mounted pivot ring 15 , and is sealed from the environment by a housing-mounted sealing ring 16 .
[0021] If a hydraulic pressure p is built up within pressure chamber 10 , spring covers 6 and 7 and the radially inner regions of diaphragm springs 8 and 9 are pressed in the direction of the arrows 17 shown in FIG. 1 , so that pressure chamber 10 becomes larger. Diaphragm springs 6 and 7 roll on the cover-mounted pivot ring 13 and on the housing-mounted pivot ring 15 , so that the pivoting motion of diaphragm springs 8 , 9 in relation to spring covers 6 , 7 and housing ring 4 is not hindered. To prevent spring covers 6 , 7 from resting on each other when the pressure reservoir is unpressurized, a seal retainer 18 is provided. The radially outer surface of seal retainer 18 is of circular form, so that it extends over the entire inner periphery of housing ring 4 , and includes a connection fitting 20 on one side as an oil inlet.
[0022] The hydraulic pressure reservoir is connected through a valve (not shown) to a hydraulic system (not shown) by the connection fitting 20 . A plurality of tongues 21 extend radially inwardly from the ring-shaped housing-mounted support 19 . The tongues 21 serve as spacers between the spring covers 6 , 7 , to prevent the latter from resting directly flat against each other. If spring covers 6 , 7 were in flat contact, the surface area pressurized with the pressure p within pressure chamber 10 would not be sufficient to press them apart against the force of the diaphragm springs. One or more tongues 21 serve at the same time to support a sensor system 22 . The outer annular groove 12 of spring covers 6 , 7 has a circumferential stop 23 , which limits the travel of spring covers 6 , 7 in the direction of the arrows 17 . Starting at a certain distance in the direction of the arrows 17 , the stops 23 contact the diaphragm springs 8 , 9 , so that the pressure force required for further movement of spring covers 6 , 7 suddenly increases.
[0023] Sensor system 22 is shown in greater detail in FIG. 4 , in addition to the showing in FIG. 1 . As shown in FIG. 4 sensor system 22 includes a first sensor 24 and a second sensor 25 . First sensor 24 is situated on a tongue 21 on the side facing spring cover 6 ; second sensor 25 is situated on the tongue 21 on the side facing spring cover 7 . First sensor 24 and second sensor 25 are securely situated relative to the housing by being mounted on one of the tongues 21 . A first magnet 26 is situated on spring cover 6 ; a second magnet 27 is situated on spring cover 7 . First magnet 26 works together with first sensor 24 , and second magnet 27 works together with second sensor 25 . When spring covers 6 , 7 move in the direction of arrows 17 , the distances between first magnet 26 and first sensor 24 and between second magnet 27 and second sensor 25 change. That distance change is converted by sensors 24 , 25 into an electrical signal, which represents the storage volume. The two sensors are situated redundantly, so that if one sensor fails the other sensor can continue to emit a pressure signal. In addition, the two signals of the sensors can be compared, so that a defect of a diaphragm spring, for example, or a mechanical impairment or the like, can be detected from the difference in the signals. Electric wires 28 from first sensor 24 and electric wires 29 from second sensor 25 are routed via one of the tongues 21 to a connector 30 on the housing.
[0024] FIG. 2 shows housing ring 4 in a separated, perspective view. It includes two identical ring portions, namely a first half-ring 31 and a second half-ring 32 . The two half-rings are joined together by connecting means 33 . The connecting means 33 can be screw flanges, for example. In the present exemplary embodiment a dovetail profile is provided in each case as the connecting means, which includes in each case a dovetail 34 and a dovetail-shaped recess 35 . In order to assemble the hydraulic pressure reservoir, the spring package is stacked and pre-stressed. The half-rings are then placed around the spring package and the dovetail profiles at the ends of the half-rings are interconnected. The two half-rings 31 , 32 are designed so that they do not become plastically deformed when they are bent slightly open in order to hook the dovetail profiles into each other. In that way it is possible to construct the reservoir without screws, welded seams, or other joining methods.
[0025] The sensors are mounted in the seal retainer or a tongue 21 of the seal retainer during injection molding of the seal retainer. The conductor paths for the electric wires 28 , 29 for the sensors 24 , 25 are also molded directly into the plastic of seal retainer 18 during injection molding, and are routed to the connector 30 to make contact with it. The two sensors assure redundancy in case one sensor fails. In addition, that redundancy makes it possible to ensure that neither of the two springs is overloaded in normal operation.
[0026] As an alternative to the above-described sensor system, the sensors can also be built into the spring covers, in which case the magnet is positioned in a tongue 21 of seal retainer 18 , as shown in FIG. 1 . However, in that arrangement an additional contact point must be provided between the housing and the sensors in order to conduct the sensor signal to the outside. Furthermore, the sensors must be molded into the spring covers. Because the spring covers must withstand significantly greater loads than the tongues 21 , higher-quality plastic and correspondingly more expensive processing are needed. In an injection molding procedure for such higher-quality plastics, temperatures and pressures occur make it impossible to injection-mold around the sensors. In that case the sensors must therefore be installed as freestanding parts.
[0027] The spring covers 6 , 7 are produced as injection-molded plastic parts, as die-cast aluminum parts, or as aluminum forgings. Magnets provided for the Hall sensors are integrated into the spring covers. In the case of plastic parts, the magnets can be included directly in the injection molding; aluminum parts must be installed later, for example by coining the edge of the aluminum material after inserting the magnet into a provided opening. The spring covers carry the pivot rings for the diaphragm springs, they include a seal surface for the seals between spring coves and the diaphragm springs, and they form a mechanical stop for the diaphragm springs. The seals can be included in the injection molding, similar to the case of a seal retainer, if the spring covers are made of plastic. If the diaphragm springs are pressed in, starting from a certain position the stop 23 comes into contact with the diaphragm spring. That results in a point of application located further outside, which brings the spring cover to a stop despite the rising pressure. This brings about an additional safety function against overloading of the diaphragm springs, along with the sensor monitoring and a pressure-limiting valve located beside the reservoir.
[0028] FIG. 3 shows the pressure conditions in the exemplary embodiment of the pressure reservoir shown in FIGS. 1 , 2 , and 4 . The arrows in FIG. 3 clearly show the pressure that is exerted on pressure chamber 10 by the diaphragm springs and spring covers 6 and 7 . The pressure acts perpendicular to the surfaces in all cases. A large part of the pressure cancels itself out, with the small part that acts outward in the radial direction being absorbed by a large proportion of material at that location. In addition, the housing ring also lies around the seal retainer 18 , and it can also absorb part of the radial deformation so that the strength demands on the material are very slight. Hence, this part can be produced of easily injectable material. It is therefore possible to operate with relatively low pressures and temperatures in the manufacturing process, which makes it possible to injection mold sensors in the middle of the spring covers, as illustrated in FIG. 4 .
[0029] Of course, other methods than the sensor system with magnets just described can also be used to detect the distance between the spring covers, and thereby the stored volume. For example, an inductive solution can be chosen. In that case a large coil with a few windings can be integrated, for example, into the middle part, called the seal retainer, which coil is subjected to a modulated electrical signal. The spring covers must now be chosen of a material that damps the frequency in the coil, independent of the distance between spring cover and coil. Aluminum is an example of such a material. Such a sensor principle requires merely one coil with very few windings, and therefore can be manufactured more economically than a Hall sensor solution.
[0030] Although particular embodiments of the present invention have been illustrated and described, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit of the present invention. It is therefore intended to encompass within the appended claims all such changes and modifications that fall within the scope of the present invention.
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A hydraulic pressure reservoir having at least one pressure chamber formed between two opposed, movable inner boundary members. Each inner boundary members includes a spring cover and a diaphragm spring. An outer boundary member peripherally surrounds the movable inner boundary members and has a U-shaped cross section along at least a part of its periphery to axially support the diaphragm springs in a fixed axial position. The outer boundary member can be formed in several pieces that are held together by interconnections or by a surrounding outer tensioning member.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a propeller system for installation in aircrafts, and more particularly to an electric pitch control apparatus for a variable-pitch propeller.
2. Description of the Prior Art
Disclosed in Japanese Patent Laid-open Publication No. 60-76499 is a pitch control apparatus for a variable-pitch propeller which is designed to control a pitch angle of the propeller blade and a rotational number of the propeller in accordance with a mach number, an altitude, an atmospheric temperature and an output power of the prime engine in flight of the aircraft to thereby maximize the operation efficiency of the propeller. Practically, the pitch angle of the propeller blade is controlled by an electro-hydraulic control device which is arranged to control a supply amount of operation fluid in accordance with a difference between a target rotational number and an actual rotation number of the prime engine.
In such a conventional pitch control apparatus, a control value of the propeller pitch is properly determined such that the actual rotational number is adjusted to coincide with the target rotational number. In the case that the electro-hydraulic control device was used for a long period of time, however, there will occur a difference between the target pitch control amount and the actual pitch control amount due to a secular change of the control device. Even if the electro-hydraulic control device was operated without any secular change, the difference between the target and actual pitch control amounts will occur if the flow amount of operation fluid changes due to fluctuation of the fluid temperature. For these reasons, an accurate control of the propeller pitch may not be effected.
SUMMARY OF THE INVENTION
It is, therefore, a primary object of the present invention to provide an electric pitch control apparatus for a variable-pitch propeller which is designed to compensate for a difference between the target and actual pitch control amounts caused by a secular change of the electro-hydraulic control device thereby to effect an accurate control of the propeller pitch.
According to the present invention, the object is accomplished by providing an electric pitch control apparatus for a variable-pitch propeller of an aircraft equipped with a pitch control mechanism having an electrically controlled actuator for controlling a pitch angle of the propeller blade in accordance with a control current applied thereto, which comprises an engine rotation sensor for detecting an actual rotational number of a prime engine of the aircraft, a throttle sensor for detecting an opening degree of a throttle of the prime engine, first means for determining a target rotational number of the prime engine in relation to the opening degree of the engine throttle, second means for calculating a difference between the target and actual rotational numbers of the prime engine, third means for determining a standard control value in relation to the calculated difference in rotational number, and fourth means for producing a control current defined by the standard control value and for applying the control current to the pitch control mechanism so that the pitch angle of the propeller blade is varied by operation of the actuator so that the actual rotational number of the prime engine coincides with the target rotational number. The electric pitch control apparatus further comprises means for determining a flight condition of the aircraft, and means for correcting the standard control value in accordance with the calculated difference in rotational number when the aircraft has been in a constant flight condition for a predetermined period of time.
BRIEF DESCRIPTION OF THE DRAWINGS
Additional objects, features and advantages of the present invention will be more readily appreciated from the following detailed description of preferred embodiments thereof when taken together with the accompanying drawings, in which:
FIG. 1 is a circuit diagram of a hydraulic control system in combination with an electric pitch control apparatus according to the present invention;
FIG. 2 is a sectional view of a pitch control mechanism of a propeller shown in FIG. 1;
FIG. 3 is a map showing a target rotational number N set of a prime engine in relation to an opening degree T Ai of the engine throttle;
FIG. 4 is a map showing a standard control amount A BS in relation to a difference N Ei between the target rotational number N set and an actual rotational number N Ei of the prime engine;
FIG. 5 is a map showing a relationship between a corrected control value A E and a control amount Q of operation fluid;
FIG. 6 is a first part of a flow chart of a control program to be executed by a microcomputer shown in FIG. 1;
FIG. 7 is a second part of the flow chart; and
FIG. 8 is a third part of the flow chart; and
FIG. 9 is a flow chart of a modification of the control program.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1 of the drawings, there is schematically illustrated an electro-hydraulic pitch control system for a variable-pitch propeller which comprises a pitch control mechanism 10, a hydraulic control circuit 20 and an electric pitch control apparatus 30 according to the present invention. As shown in FIG. 2, the pitch control mechanism 10 includes a hydraulic cylinder 11 provided with a reciprocating piston 11a loaded by areturn spring 11b, a follower pin 12 mounted on a rod portion of piston 11afor movement therewith, a hub member 13 rotatably mounted within a housing 14 integral with the hydraulic cylinder 11 and retained in place in an axial direction, the hub member 13 being formed with a cam slot 13a in engagement with the follower pin 12, a bevel gear 13b integrally provided on one end of hub member 13, and a bevel gear 15a rotatably mounted withinthe housing 14 and retained in place in an axial direction, the bevel gear 15a being integrally formed with a blade butt 15 of the propeller and meshed with the bevel gear 13b. Assuming that the hydraulic cylinder 11 has been applied with hydraulic fluid under pressure from the hydraulic control circuit 20, the piston 11a is moved rightward against the load of return spring 11b to rotate the blade butt 15 in a direction shown by an arrow P in FIG. 2. As a result, the pitch angle of the propeller blade is varied to be coarse pitch angle.
As shown in FIG. 1, the hydraulic control circuit 20 includes a fluid pump 21 arranged to be driven by a prime engine of the aircraft, a relief valve22 arranged to define a maximum pressure of hydraulic fluid discharged frompump 21, an electromagnetic flow control valve 23, and a throttle 24. The electromagnetic flow control valve 23 is operated under control of the electric pitch control apparatus 30 to control the quantity of hydraulic fluid under pressure supplied into or discharged from the hydraulic cylinder 11. The flow control valve 23 is provided with solenoids a and b to be selectively energized by a control current applied thereto from the electric pitch control apparatus 30. The flow control valve 23 is designedto be retained in a neutral position during deenergization of its solenoidsa and b. In a condition where the flow control valve 23 is retained in the neutral position, an outlet port 23a in connection to the hydraulic cylinder 11 is disconnected from inlet ports 23b and 23c respectively in connection to the delivery port of pump 21 and to a fluid reservoir 25. When the solenoid a is energized, the flow control valve 23 is displaced to provide a fluid connection between ports 23a and 23b for effecting the supply of hydraulic fluid under pressure into the hydraulic cylinder 11 from pump 21. When the solenoid b is energized, the flow control valve 23 is displaced to provide a fluid connection between ports 23a and 23c for discharging the hydraulic fluid from the hydraulic cylinder 11 into the fluid reservoir 25.
The throttle 24 is arranged to allow a small quantity of hydraulic fluid under pressure flowing therethrough into the fluid reservoir 25. If the electric pitch control apparatus 30 is damaged or the leading wires of solenoids a, b are disconnected in operation, the flow control valve 23 will be returned to and retained in the neutral position to disconnect theoutlet port 23a from the inlet ports 23b and 23c. Thus, the pressure in hydraulic cylinder 11 is maintained to avoid a sudden change of the pitch angle of the propeller blade. In such a condition, the throttle 24 causes the hydraulic fluid from cylinder 11 to gradually discharge therethrough into the fluid reservoir 25. As a result, the piston 11a of cylinder 11 ismoved leftward by the load of return spring 11b to vary the pitch angle of the propeller blade to a fine pitch angle for fail safe.
The electric pitch control apparatus 30 includes an engine rotation sensor 31 for detecting a rotational number N E of the prime engine of the aircraft, a throttle sensor 32 for detecting an opening degree of the engine throttle, a pressure sensor 33 for detecting an intake pressure of the prime engine, and a microcomputer 34 connected to the sensors 31-33. The microcomputer 34 has an interface arranged to be applied with detection signals from the sensors 31-33, a read-only memory or ROM arranged to store a control program shown by a flow chart in FIGS. 6-8 andmaps necessary for processing the control program, a central processing unit or CPU for execution of the control program, and a random access memory or RAM arranged to temporarily memorize variables for execution of the control program.
The maps stored in the ROM are in the form of three kinds of two dimensional maps shown in FIGS. 3, 4 and 5, respectively representing a target rotational number N set of the prime engine in relation to an opening degree T Ai of the engine throttle, a standard control value A BS in relation to a difference ΔN Ei between the target rotational number N set and an actual rotational number N Ei of the prime engine, and a control amount Q of hydraulic fluid in relation toa corrected control value A E . The target rotational number N set is defined to be approximately proportional to the opening degree T Ai of the engine throttle, and the standard control value A BS is defined to be approximately proportional to the difference ΔN Ei in rotational number for controlling a supply amount of electric current to the flow control valve 23 on a basis of the difference ΔN Ei in rotational number. When the standard control value A BS is positive, the flow control valve 23 is energized by a control current applied to itssolenoid b to discharge an amount of hydraulic fluid from the hydraulic cylinder 11. When the standard control value A BS is negative, the flow control valve 23 is energized by a control current applied to its solenoid a to supply an amount of hydraulic fluid to the hydraulic cylinder 11. The corrected control value A E is obtained by addition of a correction coefficient kG to the standard control value A BS , andthe control amount Q of hydraulic fluid is defined to be proportional to the corrected control value A E . In addition, each of the control values A BS , A E and correction coefficient kG is a digital value which is increased or decreased by "1" as a minimum unit. The maps are theoretically determined in consideration with the characteristics of the prime engine and the variable pitch propeller.
Hereinafter, the operation of the electric pitch control apparatus 30 will be described in detail with reference to the flow charts shown in FIGS. 6 to 8. Assuming that the prime engine of the aircraft has been started, thecomputer 34 is activated to initiate execution of the control program at step 50 shown in FIG. 6. At step 51, the CPU of computer 34 initializes variables for execution of the control program and sets the correction coefficient kG as "0" at step 52. At the following step 53, the CPU of computer 34 is applied with detection signals from the sensors 31-33 through the interface to read out an actual rotational number N Ei of the prime engine, an opening degree T Ai of the engine throttle and anintake pressure P Mi of the prime engine and to temporarily store the data in the RAM of computer 34. When the program proceeds to step 54, the CPU of computer 34 calculates a difference ΔT Ai between instantand prior opening degrees T Ai and T Ai-1 of the engine throttle detected at a predetermined time interval Δt and calculates at step 55 a difference ΔP Mi between instant and prior intake pressuresP Mi and P Mi-1 detected at the predetermined time interval Δt. At the following step 56, the CPU of computer 34 determines a target rotational number N set in relation to the instant opening degree T Ai of the engine throttle on a basis of the map shown in FIG.3 and calculates at step 57 a difference ΔN Ei between the targetrotational number N set and an actual rotational number N Ei of theprime engine.
Subsequently, a flight condition of the aircraft is determined as follows. At step 58 of the program shown in FIG. 7, the CPU of computer 34 determines whether an absolute value I T Ai I of the difference ΔT Ai in throttle opening degree is larger than a constant a defined by the characteristic of the prime engine. In the case where the value of |ΔT Ai | is greater than a, the aircraft is not in a constant flight condition, and the CPU of computer 34determines a "No" answer at step 58 and causes the program to proceed to step 64 for processing at the following step 65, 66. In the case where thevalue of |ΔT Ai | is less than a, the aircraft is in a constant flight condition, and the CPU of computer 34 determines a "Yes" answer at step 58 and causes the program to proceed to step 59 for determining whether an absolute value IΔP Mi I of the difference ΔP Mi in intake pressure is larger than a constant b defined by the characteristic of the prime engine. In the case where the value of ΔP Mi is greater than b, the aircraft is not in a constant flight condition, and the CPU of computer 34 determines a "No" answer at step 59 and causes the program to proceed to step 64 for processing at thefollowing step 65, 66. In the case where the value of ΔP Mi is less than b, the aircraft is in a constant flight condition, and the CPU of computer 34 determines a "Yes" answer at step 59 and causes the programto proceed to step 60.
When the program proceeds to step 64, the CPU of computer 34 determines a standard control value A BS in relation to the calculated difference ΔN Ei in rotational number on a basis of the map shown in FIG. 4and adds at step 65 a correction coefficient kG to the standard control value A BS to obtain a corrected control value A E . At this stage,the correction coefficient kG is maintained as "0" since the aircraft is not in a constant flight condition. At the following step 66, the CPU of computer 34 produces a control current defined by the corrected control value A E and applies it to the solenoid a or b of flow control valve 23. When the corrected control value A E is positive, the solenoid b of flow control valve 23 is energized by the control current applied from the CPU of computer 34 to discharge an amount Q of hydraulic fluid definedby the corrected control value A E from the hydraulic cylinder 11 so that the pitch angle of propeller blade 15 is decreased to increase the rotational number N Ei of the prime engine to cause it to coincide with the target rotational number N set . When the corrected control value A E is negative, the solenoid a of flow control valve 23 is energized by the control current applied from the CPU of computer 34 to supply an amount Q of hydraulic fluid defined by the corrected control value A E into the hydraulic cylinder 11 so that the pitch angle of propeller blade 15 is increased to decrease the rotational number N Ei of the prime engine to cause it to coincide with the target rotational number N set . Subsequently, the CPU of computer 34 causes the program to return to step 53 for processing at step 53-66.
When it has been determined that the aircraft is in a constant flight condition, the CPU of computer 34 determines a "Yes" answer respectively at step 58 and 59 and causes the program to proceed to step 60. At step 60, the CPU of computer 34 determines whether the absolute value IΔN Ei I of the difference ΔN Ei in rotational number is larger than a constant c defined by the characteristic of the prime engine. When the absolute value IΔN Ei I is smaller than the constant c, the actual rotational number N Ei of the prime engine tends to approach the target rotational number N set . This means that the pitch control mechanism 10 and the hydraulic control circuit 20 are normally operated or that a deviation from a proper pitch control value caused by a secular change of the pitch control mechanism has been corrected. When the absolute value IΔN Ei I of the difference inrotational number is larger than the constant c, the rotational number N Ei of the prime engine does not approach the target rotational number N set . This means that the pitch angle control of propeller blade 15 is deviated from the proper pitch control value due to a secular change of the pitch control mechanism. If there is some trouble caused by a secular change of the pitch control mechanism, the CPU of computer 34 determines a "Yes" answer at step 60 and causes the program to proceed to step 61.
At step 61, the CPU of computer 34 determines whether the difference ΔN Ei in rotational number is positive or negative. If the difference ΔN Ei in rotational number is positive, the control amount Q of hydraulic fluid is defined in relation to the corrected control value A E as shown by a dotted line m in FIG. 5. This means that the discharge amount of hydraulic fluid from the hydraulic cylinder 11 becomes too small due to a secular change of the pitch control mechanism or that the supply amount of hydraulic fluid into the hydraulic cylinder 11 becomes too large due to the secular change of the pitch control mechanism. If the difference ΔN Ei in rotational number is negative, the control amount Q of hydraulic fluid is defined in relation to the corrected control value AE as shown by a dotted line n in FIG. 5. This means that the discharge amount of hydraulic fluid from the hydraulic cylinder 11 becomes too large due to a secular change of the pitch control mechanism or that the supply amount of hydraulic fluid into the hydraulic cylinder 11 becomes too small due to the secular change. To correct such an abnormal control of hydraulic fluid, the CPU of computer 34 changes the correction coefficient kG at step 62 or 63. If the answer at step 61 is "Yes", the program proceeds to step 62 where the CPU of computer 34 increases the correction coefficient kG by "1". If the answer at step 61 is "No", the program proceeds to step 63 where the CPU of computer 34 decreases the correction coefficient kG by "1". After processing at step 62 or 63, the CPU of computer 34 causes the program to proceed to step 64.
When the program proceeds to step 64 after processing at step 62 or 63, theCPU of computer 34 determines a standard control value A BS in relationto the difference ΔN Ei in rotational number on a basis of the map shown in FIG. 4 and adds the adjusted correction coefficient kG to thestandard control value A BS at step 65 to obtain a corrected control value A E . At the following step 66, the CPU of computer 34 produces acontrol current defined by the corrected control value A E and applies it to the solenoid a or b of the flow control valve 23 for control of the hydraulic fluid discharged from or supplied into the hydraulic cylinder 11. Subsequently, the CPU of computer 34 returns the program to step 53 for processing at step 53-66 during which the correction coefficient kG isadjusted to coincide the corrected control value A E with a proper control value for control of the pitch control mechanism.
When the pitch angle control of the propeller blade is normally conducted by proper adjustment of the correction coefficient kG, the absolute value IΔN Ei I of the difference ΔN Ei in rotational number becomes smaller than the constant c. In this instance, the CPU of computer34 determines a "No" answer at step 60 and causes the program to proceed tostep 64. Subsequently, the CPU of computer 34 determines at step 64 a standard control value A BS in relation to the difference ΔN Ei in rotational number and calculates at step 65 a correctedcontrol value A E without any change of the correction coefficient kG. Thus, the CPU of computer 34 produces a control current defined the corrected control value A E and applies it to the solenoid a or b of the flow control valve 23 for control of the hydraulic fluid discharged from or supplied into the hydraulic cylinder 11. As a result, the pitch angle of the propeller blade is controlled to an optimum angle for coinciding the actual rotational number of the prime engine with the target rotational number N.sub. set.
From the above description, it will be understood that when the aircraft isin a constant flight condition, a standard control value A BS is determined in relation to a difference ΔN Ei in rotational number and is corrected by addition of a correction coefficient kG to obtain a corrected control value A E . With such control based on the corrected control value A E , a deviation of the pitch control value caused by a secular change of the pitch control mechanism can be compensated to effect a proper pitch angle control of the propeller blade.
In FIG. 9 there is illustrated a modification of the control program which is designed to execute processing at step 053 for determining a temperature of hydraulic fluid stored in the fluid reservoir 25 and processing at step 153 for setting the pitch angle of the propeller blade to a minimum angle L o . To execute the processing at step 053, the computer 34 is further connected to a thermal sensor (not shown) arranged to detect a temperature T oil of hydraulic fluid stored in the fluid reservoir 25 for producing a detection signal indicative of the detected temperature T oil .
Assuming that the computer 34 has been activated to initiate execution of the modified control program at step 50 shown in FIG. 9, the CPU of computer 34 initializes at step 51 variables for execution of the modifiedcontrol program and sets the correction coefficient kG as "0" at step 52. At the following step 53, the CPU of computer 34 is applied with detectionsignals from the sensors 31-33 and the thermal sensor through the interfaceto read out an actual rotational number N Ei of the prime engine, an opening degree T Ai of the engine throttle, an intake pressure P Mi of the prime engine and a temperature T oil of hydraulic fluid and to temporarily store the data in the RAM. When the program proceeds to step 053, the CPU of computer 34 determines whether the detected temperature T oil of hydraulic fluid is higher than a predetermined temperature T (for instance, 60° C.). If the answer at step 053 is "No", the program proceeds to step 153 where the CPU of computer 34 sets a target rotational number N set as a maximum rotational number N max and issues a control current for setting the pitch angle of the propeller blade to a minimum angle Lo to apply it to the solenoid b of flow control valve 23. When applied with the control current from the CPU of computer 34, the solenoid b of flow control valve 23 is energized to discharge the hydraulic fluid from hydraulic cylinder 11 so that the pitch angle of the propeller blade is minimized to increasethe rotational number N Ei of the prime engine for warming up.
When the prime engine is warmed up, the temperature of hydraulic fluid becomes higher than the predetermined temperature T. In this instance, theCPU of computer 34 determines a "Yes" answer at step 053 and causes the program to proceed to step 54 for calculating a difference ΔT Ai between instant and prior opening degrees T Ai and T Ai-1 of the engine throttle detected at the predetermined time interval Δt. Subsequently, the CPU of computer 34 executes the control program in the same manner as described above.
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An electric pitch control apparatus for a variable-pitch propeller equipped with a pitch control mechanism having an electrically controlled actuator for controlling a pitch angle of the propeller blade in accordance with a control current applied thereto. The electric pitch control apparatus is designed to compensate a difference between target and actual pitch control amounts caused by a secular change of the pitch control mechanism thereby to effect an accurate control of the propeller pitch.
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CROSS REFERENCE TO RELATED APPLICATION
Not Applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable.
REFERENCE TO A MICROFICHE APPENDIX
Not Applicable.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to nozzles used in washing liquid distribution systems particularly to nozzles used in spiral separators.
2. Relevant Art
The present invention relates to nozzles used in spiral separators such as those illustrated in U.S. Pat. No. 6,527,125 to Niitti.
BRIEF SUMMARY OF THE INVENTION
In one aspect of the present invention there is provided in a washing liquid distribution system comprising a spiral separator including a plurality of flights, each flight including at least one receiving cup for distributing liquid onto the flight, a directional outlet nozzle mounted in the cup for providing a horizontal outlet stream of a liquid. The nozzle is rotatably mounted in the cup. The nozzle is releasably mounted to the cup. The nozzle has either a single outlet opening or two oppositely disposed outlet openings. The nozzle has an elongated lower portion extending downwardly from the cup and an upper portion for mounting the nozzle to the cup. The outlet opening is located in the lower portion. The lower portion has a vertically disposed portion and a horizontal substantially planar portion, the outlet opening being in the vertically disposed portion. The nozzle includes a housing having an exterior surface formed to include a pair of oppositely disposed flat portions for grasping the nozzle by a user.
In another aspect of the present invention there is provide in a washing liquid distribution system comprising a spiral separator including a plurality of flights, each flight including at least one receiving cup for distributing liquid onto the flight, a directional outlet nozzle rotatably mounted in the cup, the cup having one horizontally disposed outlet opening for providing a horizontal outlet stream of a liquid. The nozzle is releasably mounted to the cup. The nozzle has a second outlet opening oppositely disposed from the one outlet opening. The nozzle has an elongated lower portion subtending from the cup and an upper portion for mounting the nozzle to the cup. The one outlet opening is located in the lower portion. The lower portion has vertically a disposed portion and a horizontal substantially planar portion, the one outlet opening being located in the vertically disposed portion. The nozzle includes a housing, the housing including an exterior surface having a pair of oppositely disposed flat portions for grasping the nozzle by a user.
In a further aspect of the present invention there is provided in a washing liquid distribution system comprising a spiral separator including a plurality of flights, each flight including at least one receiving cup for distributing liquid onto the flight, a direction outlet nozzle rotatably and releasably mounted in the cup the cup having one horizontal disposed outlet opening for providing a horizontal outlet stream of a liquid. The one outlet opening is a substantially circular passageway or it is a substantially vertically disposed rectangular slot. The one outlet opening is formed by a pair of vertically disposed elongated curved sides, each side having an upper portion and a lower portion, the upper portions of the sides being joined together and the lower portion of the sides joined together to form the one outlet opening.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
The novel features believed to be characteristic of this invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and method of operation, together with further objects and advantages thereof may best be understood by reference to the following description taken in connection with the accompanying drawings in which:
FIG. 1 is a perspective view of a portion of a spiral separator according to the prior art;
FIG. 2 is a front view of the directional nozzle in accordance with the present invention;
FIG. 2A is a perspective view of a portion of a spiral separator utilizing a directional nozzle in accord with the present invention;
FIG. 3 is a side view of the nozzle of FIG. 2 ;
FIG. 4 is a front view of an alternative embodiment of a directional nozzle in accord with the present invention;
FIG. 5 is a front view of another embodiment of a directional nozzle in accord with the present invention;
FIG. 6 is a side view of another directional nozzle in accordance with the present invention;
FIG. 7 . is a side view of another directional nozzle in accordance with the present invention; and
FIG. 8 is a front view of the nozzle of FIG. 7 .
DETAILED DESCRIPTION OF THE INVENTION
U.S. Pat. No. 6,527,125 discloses a washing liquid distribution system employing spiral separators. Internally a plurality of dampening receivers receive the washing liquid into a top portion and provide a low kinetic energy liquid flow output onto the material being separated via the distribution system ( FIG. 1 ).
Control of the flow in many separation systems is accomplished via pet-cocks or valves in line with a supply hose. Because the outlet flow is to be very low, very small openings are provided. The disadvantage with this approach is that the openings are subject to clogging. A larger opening can be used to prevent clogging but the very low flow required to aid in separation results in an unstable liquid stream.
In the present invention, the outlet from a receiver is via a small passageway formed in a removable and rotatable insert mounted in the bottom of the receiver. The inserts provide outlet holes that can be elongated in the vertical or horizontal or both directions.
The inserts provide a means whereby the outlet stream can be directed towards the vertical divider that separates the separator trough from the concentrate trough with the stream having a horizontal component. The horizontal component of the flow can be directed upstream or downstream as desired in the circumstances. The small head developed within the insert provides for a stable flow stream. In addition, a larger outlet opening prevents clogging.
With respect to the drawings, FIG. 2 illustrates receiver cup 10 having an inlet flow pipe 11 . The specific construction of cup 10 may vary In the circumstances. In particular, horizontal pipe 12 (shown in broken line) may be provided to direct some of the incoming flow to another cup 10 as illustrated in Pat. No. 6,524,125, referenced hereinabove and incorporated herein in its entirety.
The receiver cup 10 preferably is formed to provide a recess 13 into which the directional nozzle formed as an insert 14 will be mounted. Recess 13 provides a collection point for the incoming liquid to stabilize the liquid flow prior to exiting via horizontally disposed outlet opening 15 . The diameter, shape, and angle with the horizontal of the outlet 15 vary with the specific separation application.
The upper portion 16 of insert 14 is formed as a flange 17 that fits tightly into recess 13 . The lower portion 18 is sized in height to create a head of approximately 1.0″ to provide for a stable stream. The lower tapered portion 19 assists in directing the flow to outlet 15 . Preferably, insert 14 has a pair of oppositely disposed flats 20 to allow the insert 14 to be rotated to position outlet 15 in the desired location.
FIG. 2A illustrates the relationship of receiving cups 10 in accord with the present invention with respect to the spiral separator. With regard to the upper flight 30 ′, an upper receiving cup 10 feeds water onto the flight 30 ′ as does a lower cup 10 . An outlet pipe 12 is not used in this particular configuration. See U.S. Pat. No. 6,524,125.
The lower flight 30 ″(preferably identical to upper flight 30 ′) in FIG. 2A employs an upper receiving cup 10 that includes outlet pipe 12 to feed into a lower cup 10 which provides effluent only to the flight 30 ″.
Each receiving cup 10 is identical but may employ different nozzles such as those shown in FIGS. 2-8 as desired in a specific application. Incoming flow is directed by the hoses 26 ′ and pipe 28 ′ that may be of any appropriate size or number for the specific application.
A side view of insert 14 is illustrated in FIG. 3 . Flange 17 is formed to provide a smooth rounded inlet portion 21 to further stabilize the incoming flow downwardly through passageway 22 for greater stability of the outlet stream. The insert 14 is formed of material that is appropriate in the circumstances.
With respect to FIG. 4 , an alternate insert 23 having a rounded inlet 24 and flange 25 that fits tightly into a recess 13 of a cup 10 . Flats 26 provide a means for grasping the insert 23 and rotating it to a desired position. The outlet 27 is a vertically elonoated generally rectangular slot that provides a horizontally directed flow.
In FIG. 5 , another embodiment of a directional nozzle in accord with the present invention is illustrated by insert 28 . A rounded inlet 29 and flange 30 fits tightly into recess 13 of a cup 10 . Flats 31 allow for rotation of the insert 28 . Outlet 32 is formed as a curved slot to provide a horizontally directed outlet stream.
In FIG. 6 , another embodiment of a nozzle is illustrated by insert 33 having a rounded inlet 34 and flange 35 fits into recess 13 . Flats 36 provide a grasping surface as before. Two oppositely disposed outlets 37 are provided to allow for two oppositely disposed horizontal outlet streams.
In FIGS. 7 and 8 , an embodiment of an insert 38 having outlets formed as angled slits 42 formed therein. Inlet 39 , flange 40 , and flats 41 are as before. The slits 42 provide a substantially horizontal fan-like outlet stream. Alternatively the slits 42 may be horizontal as shown by broken lines 43 or any angle between the approximately 45° angle of slits 42 and slits 43 .
The particular insert chosen for a given application will depend on the material that is being processed as understood in the art.
While the invention has been described with respect to certain specific embodiments, it will be appreciated that many modifications and changes may be made by those skilled in the art without departing from the spirit of the invention. It is intended, therefore, by the appended claims to cover all such modifications and changes as fall within the true spirit and scope of the invention.
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A washing liquid distribution system includes a spiral separator having a plurality of flights, each flight including at least one receiving cup for distributing liquid onto the flight. A directional outlet nozzle is mounted in cup for providing a horizontal outlet stream of a liquid. The nozzle is both rotatably and releasably mounted in a recess at the bottom of the cup. One or more outlet openings in a variety of geometric shapes to provide the desired outlet stream of wash liquid.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to battery chargers and more particularly, to such a battery charger that is adjustable to fit different sizes of battery cells.
[0003] 2. Description of the Related Art
[0004] A conventional battery charger comprises a power circuit unit for converting AC power supply into DC power supply, and a charging circuit unit for charging inserted battery with output DC power supply from the power circuit unit. This design of battery charger does not provide any added function. Further, this design of battery charger can only charge a specific size of battery cells.
SUMMARY OF THE INVENTION
[0005] The present invention has been accomplished under the circumstances in view. It is therefore the main object of the present invention to provide a battery charger, which is adjustable to fit different sizes of battery cells. It is another object of the present invention to provide a battery charger, which provides an added illumination function. According to one aspect of the present invention, the battery charger comprises a power supply unit for converting AC power supply into DC power supply, and a charging unit, which is detachably connected to the power supply unit and adjustable through a rotary knob to change the length of the battery chambers thereof to fit different sizes of battery cells to be charged by the charging unit. According to another aspect of the present invention, the power supply unit has a plurality of light emitting diodes for giving off light for illumination, and a lens through which the light of the light emitting diodes passes to the outside for illumination.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is an exploded view of a battery charger according to the present invention.
[0007] FIG. 2 shows the power supply unit and the charging unit respectively assembled before insertion of the charging unit into the top accommodation open chamber of the power supply unit according to the present invention.
[0008] FIG. 3 corresponds to FIG. 2 , showing the charging unit inserted into the top accommodation open chamber of the power supply unit.
[0009] FIG. 4 is a side view in section of the battery charger according to the present invention.
[0010] FIG. 5 is similar to FIG. 4 but showing the pitch between the metal contact members of the locating plate and the metal contact members of the slide adjusted.
[0011] FIG. 6 is a circuit diagram of the circuit board of the charging unit.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0012] Referring to FIGS. 1˜5 , a battery charger in accordance with the present invention is shown comprised of a power supply unit 100 , and a charging unit 200 .
[0013] The power supply unit 100 comprises a casing 10 , a circuit board 14 mounted inside the casing 10 , and a cover shell 11 covering the casing 10 . The circuit board 14 has metal blades 15 extending out of the casing 10 for insertion into an AC outlet to receive city power supply for conversion into DC power supply by the circuit board 14 , an electric output connector 16 for DC output, a switch 17 for switching on/off the electric output connector 16 , and a plurality of LEDs (light emitting diodes) 18 . The cover shell 11 has a lens 13 through which the light of the LEDs 18 pass to the outside of the power supply unit 100 for illumination, and a top accommodation open chamber 12 adapted to accommodate the charging unit 200 .
[0014] The charging unit 200 comprises a battery holder 20 , which has a plurality of battery chambers 21 for holding battery cells V and a sliding hole 22 axially disposed in one end, a locating plate 30 , which is fastened to one end of the battery holder 20 opposite to the sliding hole 22 and has a plurality of metal contact members 31 respectively disposed in contact with one terminal of each battery cell V installed in the battery chambers 21 , a circuit board 32 , which is mounted on the locating plate 30 and has an electric output connector 33 for DC output and a selector switch 34 for switching on/off the electric output connector 33 between a first position to provide power supply to an external electric apparatus and a second position to charge the battery cells V; when switching on the electric output connector 33 , the charging unit 200 works to provide power supply to an external electric apparatus), a cap 35 capped on one end of the battery holder 20 and covered over the locating plate 30 and the circuit board 32 , a spring member 23 mounted inside the sliding hole 22 of the battery holder 20 , a slide 24 axially slidably coupled to the battery holder 20 , an actuating member 27 , a cover shell 28 , and a rotary knob 29 . The slide 24 has a plurality of metal contact members 25 for contacting the other terminal of each battery cell V installed in the battery chambers 21 , a projecting guide bar 26 , which has a beveled guide face 260 , and a coupling rod 240 and slidably inserted into the sliding hole 22 of the battery holder 20 and stopped against the spring member 23 . The cover shell 28 is capped on one end of the battery holder 20 opposite to the cap 35 to hold the actuating member 27 in place. The actuating member 27 is inserted through the cover shell 28 and affixed to the rotary knob 29 , having two beveled guide faces 270 selectively disposed in contact with the beveled guide face 260 of the projecting guide bar 26 . When rotating the rotary knob 29 , the actuating member 27 is rotated with the rotary knob 29 to move the associating beveled guide face 270 against the beveled guide face 260 of the projecting guide bar 26 , thereby adjusting the pitch between the metal contact members 31 of the locating plate 30 and the metal contact members 25 of the slide 24 subject to the size (length) of the battery cells V that are installed in the battery chambers 21 .
[0015] When the charging unit 200 is inserted into the top accommodation open chamber 12 of the cover shell 11 of the power supply unit 100 , the circuit board 32 is electrically connected to the electric output connector 16 of the circuit board 14 .
[0016] Referring to FIG. 6 , the circuit board 32 of the charging unit 200 comprises a voltage dropping circuit 1 , adapted to drop the voltage of the output power supply of the power supply unit 100 into a predetermined charging voltage for charging the battery cells V that are mounted in the battery chambers 21 of the battery holder 20 , a protection circuit 2 comprised of a transistor Q 2 and electrically connected to the output end of the voltage dropping circuit 1 for cutting off the circuit when the voltage passing out of the voltage dropping circuit 1 into the protection circuit 2 is abnormal (surpassed a predetermined voltage level), a booster circuit 3 electrically connected to the output end of the protection circuit 2 to boost the voltage of output power outputted from the protection circuit 2 for supply to an external electric apparatus through the electric output connector 33 of the circuit board 30 of the charging unit 200 when the switch 34 is switched to the first position (switched on the electric output connector 33 ), and a charging indicator circuit 4 comprised of a transistor Q 3 and a LED D. During a charging operation of the battery charger, the transistor Q 3 is electrically connected to turn on the LED D, giving a signal indicative of the charging operation.
[0017] Referring to FIGS. 3 and 4 again, when the switch 34 is switched to the second position (switched off the electric output connector 33 ) after connection of the metal blades 15 to an electric outlet, the circuit board 14 of the power supply unit 100 converts AC power supply into DC power supply for the circuit board 32 of the charging unit 200 to charge the battery cells V that are inserted into the battery chambers 21 of the battery holder 20 .
[0018] Referring to FIGS. 4 and 5 again, the user can rotate the rotary knob 29 to force the actuating member 27 to move the slide 24 , thereby adjusting the pitch between the metal contact members 31 of the locating plate 30 and the metal contact members 25 of the slide 24 subject to the size (length) of the battery cells V that are installed in the battery chambers 21 .
[0019] A prototype of battery charger has been constructed with the features of FIGS. 1˜6 . The battery charger functions smoothly to provide all of the features discussed earlier.
[0020] Although a particular embodiment of the inventions has been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims.
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A battery charger is disclosed to includes a power supply unit for converting AC power supply into DC power supply, and a charging unit, which is detachably connected to the power supply unit and adjustable through a rotary knob to change the length of the battery chambers thereof to fit different sizes of battery cells to be charged by the charging unit.
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FIELD OF THE INVENTION
[0001] The invention relates to the method, architecture and interfaces that allow synchronous transfer mode (STM) traffic to be efficiently transported via an asynchronous transfer mode (ATM) network.
BACKGROUND OF THE INVENTION
[0002] In telecommunications systems, the protocol utilized for offering a wide range of high-bandwidth services, e.g., multimedia services, will most likely be based on Asynchronous Transfer Mode (ATM) protocols. These protocols define a particular data structure called a “cell”, which is a data packet of a fixed size (e.g., 53 octets, each comprising eight bits).
[0003] Typically, ATM standards are based on signaling schemes designed to accommodate multimedia applications. The recent research into advance ATM network architectures has been conducted as illustrated by U.S. Pat. No. 5,588,475, U.S. Pat. No. 5,483,527, and U.S. Patent Application No., entitled An ATM Network Arranged to Interface with STM In-Band Signaling, filed on Dec. 21, 1994, to Doshi et al., and assigned case number 10-2-5-2-2-2-2. Conventional approaches include the use of statistical multiplexing including voice compression in an ATM environment. However, these approaches may require the introduction of Variable Bit Rate (VAR.) capabilities, including sophisticated signaling mechanisms and a different ATM adaptation layer, AAL-2. None of the conventional approaches provide for ATM call set-up using standard signaling systems, traffic management between a terminal adapter and an ATM switch, or variable background noise.
SUMMARY OF THE INVENTION
[0004] The invention includes various architectures, structures, and methods for addressing the above mentioned problems. In accordance with aspects of the invention, fax, voice and data calls may be efficiently processed by an Asynchronous Transfer Mode (ATM) switch by re-using a conventional Synchronous Transfer Mode (STM) network signaling system. A standard ATM AAL-1 adaption layer may be utilized to accomplish voice compression. STM-to-ATM call translation may be accomplished by a mapping that is determined based on a Virtual Path/Virtual Circuit occupancy status to take full advantage of available bandwidth by eliminating marked cells.
[0005] Our research disclosed in this application has advanced the state of the art by specifying the specific architectures which enable STM to ATM interfaces and which allow a Constant Bit Rate (CBR) call in an ATM domain using existing (i.e., STM in-band or out-of-band) signaling mechanisms to forward a call to its destination. Architectures in accordance with the present invention facilitate the use of ATM technology to carry traditional voice, fax and voice-band data traffic and demonstrate that the evolution to broadband signaling is not necessary in the initial period of STM-to-ATM transition.
[0006] Our proposals define network architecture and ATM capabilities required to transport voice efficiently in the ATM domain. It exploits STM network signaling and modifies standard ATM adaptation layer AAL-1 to achieve voice compression. Specifically, to eliminate silence, we augment the cell-building process with appropriate cell marking. In the case of congestion, marked cells that do not contain voice signals are discarded by either the Terminal Adapter or the ATM switch.
[0007] We also describe specific rules for STM-to-ATM call routing translation. This mapping may be determined at each instance based on the Virtual Path/Virtual Circuit (VP/VC) occupancy status to take full advantage of the potentially available bandwidth (no marked cells). We also define a method for obtaining and monitoring VP/VC/buffer occupancy data that allows the ATM switch to control bandwidth usage and prevent to performance degradation associated with cell loss (a third key idea).
[0008] Our proposal results in bandwidth (transport) and switch termination savings and could be applicable in a variety of wide area or local area network settings and in the PABX to ATM environment.
[0009] These and other features of the invention will be apparent upon consideration of the following detailed description of preferred embodiments. Although the invention has been defined using the appended claims, these claims are exemplary in that the invention is intended to include the elements and steps described herein in any combination or subcombination. Accordingly, there are any number of alternative combinations for defining the invention, which incorporate one or more elements from the specification, including the description, claims, and drawings, in various combinations or subcombinations. It will be apparent to those skilled in network theory and design, in light of the present specification, that alternate combinations of aspects of the invention, either alone or in combination with one or more elements or steps defined herein, may be utilized as modifications or alterations of the invention or as part of the invention. It is intended that the written description of the invention contained herein covers all such modifications and alterations.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The foregoing summary of the invention, as well as the following detailed description of preferred embodiments, is better understood when read in conjunction with the accompanying drawings. For the purpose of illustration, embodiments showing one or more aspects of the invention are shown in the drawings. These exemplary embodiments, however, are not intended to limit the invention solely thereto.
[0011] [0011]FIG. 1 illustrates an overall architecture of an embodiment incorporating one or more aspects of the present invention.
[0012] [0012]FIG. 2 shows details of the terminal adapter of FIG. 1.
[0013] FIGS. 3 shows details of an ATM switch for use in the architecture of FIG. 1.
DETAILED DESCRIPTION
[0014] [0014]FIG. 1 illustrates an one embodiment of the invention where the processing of voice over an ATM network is achieved utilizing a conventional call set-up/routing processes. Additionally, aspects of the architecture may be utilized to achieve compression efficiencies. Referring to the exemplary embodiment of the switching network 1 , a first telephone 2 may be interconnected via a synchronous transfer mode (STM) switch 3 to a terminal adaptor (TA) 4 and a signal transfer point plane 17 . The terminal adaptor 4 may be utilized to couple analog voice calls from the phone 2 to the ATM switch A 5 . Data may thereafter be transported across the ATM network 12 via conventional mechanisms to ATM switch B 13 for transmission to Terminal adaptor B 14 . In exemplary embodiments, the ATM toll switches A, B represent originating and terminating nodes for the AT&T long distance (wide area) network such as those switches located at two local offices.
[0015] A similar network configuration may be initiated by utilizing a LAN in place of the ATM toll switches A, B. In the LAN configuration, toll switches A, B, are replaced with a LAN, or frame relay router.
[0016] Out-of-band Signaling
[0017] For the purposes of example, the embodiment illustrated in FIG. 1 has telephone 2 located at a distance from telephone 16 , and thus calls originating from telephone 2 arrive at a central office located at a distance from telephone 16 . In the STM type call set-up process (SS 7 out of band signaling), it is desirable to configure the ATM switches A, B, to include translators T configured for translating STM call set-up instructions into instructions understood by an ATM Fabric controller (not shown) located in each ATM switch A, B. The translators T may be variously configured, but most preferably translate the STM call set-up instructions into commands which define a new Virtual Path/Virtual Circuit connection path across ATM network 12 to carry the data of the telephone call.
[0018] Where the call has been initiated, STM switch 9 may alert an associated ATM switch (e.g., ATM switch A 5 ), that a call has been initiated by sending a call set-up message via a signaling path on STP Plane 17 through the translators T to the ATM switch A 5 . The ATM switch A 5 then defines a virtual circuit/virtual path to the destination ATM switch B 13 for transport of data associated with the call. The virtual circuit/virtual path may be established using any suitable routing strategy (for example) (Real Time Network Routing (RTNR) in the case of AT&T) where the originating toll switch identifies a logical path and/or logical circuit (single link or two-link in the case of RTNR) for the call to reach the terminating ATM toll switch (e.g., ATM switch B 13 ). The data is then sent from phone 2 , through STM switch A 3 , through terminal adaptor A 4 , through ATM switch A 5 , through the ATM switching network 12 , through ATM toll switch B, through terminal adaptor B 14 , through STM switch B 15 and to phone 16 .
[0019] In the forgoing configuration, when a call is initiated, a call set-up message is sent across the STP plane 17 to initiate the call with telephone 16 . In this embodiment, the call set-up information may be processed using conventional SS 7 call set-up signaling techniques across the STP plane B 17 . Since the call set-up techniques of SS 7 are conventional, these techniques are not described in detail herein. The call set-up is progressed through a plurality of interconnected STM Switches (e.g., STM Switches 7 - 12 ). Thereafter, data is transmitted via the ATM switching network.
[0020] In-band Signaling
[0021] In the second exemplary embodiment, the configuration shown in FIG. 1 may operate using in-band signaling. In actuality, in-band signaling may be more correctly described as a hybrid system using aspects of SS 7 signaling and aspects of in-band ATM signaling. The overall architecture for this hybrid system may be described below.
[0022] A call set-up message (referred to as an Initial Address Message, IAM) may be configured to contain:
[0023] a) the destination number,
[0024] b) the Automatic Number Identification, ANI, of the calling station, and
[0025] c) the identities of the trunk sub-group and trunk that will be sued to send the call to the toll switch.
[0026] The LAM message may be sent via the STP plane to the ATM switch A. Thereafter, the ATM switch A may forward the IAM messages across the ATM switching network 12 . The call processor of the ATM Switch A may store the IAM message and use the destination number to identify the terminating toll switch, i.e., ATM switch B 13 in this example). Then, based on the routing strategy (for example Real Time Network Routing (RTNR) in the case of AT&T), the originating toll switch identifies a logical path (single link or two-ink in the case of RTNR) for the call to reach the terminating ATM toll switch (e.g., ATM switch B 13 ). This routing mechanism may use a trunk hunting algorithm to identify a particular trunk that will carry the toll call. The IAM message, which may include trunk and trunk sub-group information, may then be sent to the terminating ATM toll switch (ATM switch B 13 ) via a signaling path across the ATM network. The terminating toll switch (ATM Switch B 13 ) may then send the IAM message to STM SW B 15 , and may also include specific trunk information as well as the call destination number in the transfer. The transfer of the signaling information may occur via translator B 18 B, across path 19 B, through STM switches 10 , 11 , and 12 in the STP Plane 17 to STM switch B 15 .
[0027] Local STM switch B 15 may thereafter verify that the destination telephone is idle. If it is, local STM switch B may supply a ringing voltage to the telephone line, change the incoming/outgoing trunk status to busy, and then return a call complete message to the terminating toll switch ATM Switch B 13 . ATM Switch B 13 may then be configured to change the status of incoming/outgoing trunks and passe the call complete message to the originating toll switch ATM Switch A 5 . Similarly, the originating toll switch (ATM Switch A) may be configured to change the status of trunks that were identified to establish the connection through the switching fabric and passe the call complete message to the STM switch A 3 . Now, STM SW A 3 is ready to establish the call, e.g., through the ATM switching network 12 .
[0028] Conventionally, ATM switches A and B, are incapable of understanding IAM messages and other call set-up information. In order for ATM Switches A and B to be configured to carry compressed (sub-64 kb/s) voice and fax calls in the above embodiments, certain modifications need to be made. As described in more detail below, the ATM switches in accordance with aspects of the present invergion may be modified to have certain capabilities (e.g., located in the terminal adaptors 18 A, 18 B) to enable set-up of the connection in accordance with the network architecture illustrated on FIG. 1. The call set-up procedures may be designed to enable the voice and fax calls to be carried at 64 kb/s and/or various sub-rates.
[0029] Terminal Adapter
[0030] Referring to FIG. 2, the terminal adapter 18 A, 18 B may be variously configured. In one embodiment, the terminal adapter receives the STM signal 30 from the STM switch A 3 . A signal classifier 21 is included in order to be able to apply an optimized compression algorithms. For example, the signal classifier (SC) 21 may be configured to identify voice, fax and voice-band data calls. As shown in FIG. 2, it may be desirable to include separate Echo Control (EC) and True Voice (TV) functionality within the terminal adapter 4 after the signal classifier. The echo control/true voice module 22 may be provided either inside or outside of the TA 4 . For example, the echo control/true voice quality enhancements may be done in the STM domain. Thereafter, low-bit rate encoding techniques may be employed in the terminal adapter such as voice compression (VoC) 23 and/or Fax Re-modulation (FR) 27 . These algorithms could provide bandwidth advantage by a factor of 4 or above with minimum perceptible quality degradation.
[0031] The compressed voice/fax signal (e.g., a 16 kb/s data stream) may be used to produce ATM cells using, for example a STM-to-ATM converter (SAC) 24 . The STM-to-ATM converter (SAC) 24 may be variously configured. In one exemplary embodiment, the SAC 24 may operate in a CBR mode and using standard ATM Adaptation Layer (AAL-1) for STM-to-ATM conversation function. In this example, voice calls produce cells at a constant rate either during a speaking spurt or during silence periods. The payload may be variously configured but n exemplary embodiments is 47 bytes.
[0032] In further embodiments, a silence detection module 32 may be included in the terminal adapter. The silence detection module 32 may be configured to determine a level of speech activity for each cell. The silence detection module 32 may include a marking module 34 which may be configured to mark cells with an indication of a level of speech activity occurring in data stored in a particular cell. The level of speech activity marked in a particular cell may be any number of levels. In the most rudimentary embodiment, the level of speach activity may contain only two levels and mark speech that represents silence only and those cells that contain even partial voice spurts. Where only two levels are utilized, cells can be marked using the standard Cell Loss Priority (CLP) bit, for example. Where three or more levels of voice activity are utilized (e.g., silence, partial voice spurts, speech), it may be desirable to mark each of these levels using two or more defined bits. With three or more levels of voice activity are utilized, the silence cells representing periods of silence would be dropped first, the intermediate cells representing periods of partial voice spurts would be dropped second, and the speech cells would be maintained in-tact if possible. Where intermediate cells and/or silence cells are dropped, it may be desirable to replace these cells by replicating the one of the last silence cell received.
[0033] The silence detection module 32 may be variously utilized to either discard silence cells and/or to conditionally discard silence cells as necessary. In one exemplary embodiment, all marked and unmarked cells may be output to the terminal adapter output buffer 29 . At any time after the marking of the cells, marked cells may be dropped if there is congestion. However, where there is sufficient bandwidth, which is most of the time for well-designed networks, there is no need to discard marked cells and hence the over fidelity of the voice call is substantially improved without the need to substitute comfort noise in the background. Thus, there is no need to model the silence/background noise under normal conditions and, most importantly, performance degradation due to silence elimination is avoided. Additionally, where cells are dropped, it may be desirable to simply repeat the last silence period cell in place of the dropped cell. This system may be particularly effective where the ATM switches have a rule based mechanism which limits the number of silence period cells which may be dropped to around 66.6% of the overall cells. This percentage may of course vary between different ranges such as 50-85% of the cells depending on the network topology and the desired background noise fidelity.
[0034] In exemplary embodiments, a number of cells processed by the terminal adapter 4 may be stored in the output buffer 29 . Accordingly, there may be times when the queue in the output buffer 29 approaches an overflow condition. The probability of a buffer overflow may be increased where the terminal adapter 4 is configured to have several channelized calls (DS3s) as inputs to TA and only a single DS3 carrying cells as output. In these embodiments, there is an increased probability of a queue overflow in the output buffer 29 .
[0035] Where the cells are marked, a queue overflow in output buffer 29 may be addressed by discarding marked cells in the case of an impending buffer overflow. Cell dropping for marked cells may occur at the originating terminal adapter, in the ATM switching network 12 (including ATM switch A, B 5 , 13 , or at the destination TA 14 .at subsequent ATM network element, is complemented by Cell Insertion (CI) at the destination terminal adapter 14 . Since the cell inter-arrival relationship on a VC is retained and the cells are numbered, the destination terminal adapter 14 may utilize a silence insertion (SI) module 33 to identify how many cells are missing and where the missing silence cells may be re-inserted. Thereafter, the silence insertion module 33 may insert cells using any suitable algorithm. For example, inserted cells may be formed as copies of other marked cells for this connection (VC), or may be formed from a model for background noise for the particular call in progress.
[0036] STM-to-ATM Translation
[0037] In existing AT&T long distance networks, all voice, fax and voice-band data calls require a 64 kb/s channel. In embodiments of the architecture disclosed in the present to invention, it may be desirable to establish one Virtual Circuit (VC) per call which may have either a variable and/or fixed bandwidth. For example, bandwidth of the virtual circuit may depend on the type of call being initiated as, for example, detected at the signal classifier 21 with different bandwidths utilized for different type of calls.
[0038] Although there is no bandwidth equivalency between trunks and trunk sub-groups on the STM side and Virtual Paths (VP) and VCs on the ATM side, it may be desirable to establish a one-to-one correspondence between the two paradigms. For example, each trunk sub-group I may be mapped into a unique VP, and each trunk j from sub-group i may be mapped into a unique VC. This mapping has significant advantages in maintenance and support. In these embodiments, the mapping may assign the first trunk to the first virtual circuit provided the number of virtual paths are sufficient to guarantee that there are as many simultaneous virtual connections (VCs) as the corresponding trunk sub-group.
[0039] In certain ATM networks with many terminal adapters 4 , there may be lack of bandwidth on the terminal adapter to ATM switch link. In these networks, it may be desirable to configure the bandwidth of these links to carry an expected call type mix of voice, fax, and data type calls. In unusual circumstances where there are many uncompressed voice-band data calls, the ATM switch may block certain calls where the actual bandwidth usage on a particular virtual path is in danger of being exhausted.
[0040] In exemplary embodiments, the ATM switch may be better able to deal with congestion situations where the ATM switch is supplied with information about the call type from the signal classifier 21 for each of the active VCs. This information may be communicated to the ATM switch using any suitable mechanism such as by dedicating a special VC for this purpose. For example, the payload of the cells of this VC could be partitioned in fixed fields and populated with the requisite information. For instance, it could be partitioned into 16 consecutive 3-octet fields. Each of the first 15 fields consists of a 2-octet VCI value with the remaining octet used to indicate its busy/idle status and indicating call type (voice, fax or voice-band data). The first octet of the last field may indicate the traffic condition of the virtual path (e.g., the status of the buffer feeding the virtual path). The remaining 2 octets may be used for error control by providing a cell sequence number and a CRC.
[0041] This traffic management type of data may be used by the ATM switch to assess whether or not there is sufficient bandwidth on a particular VP to accept one more call. To avoid service degradation (loss of unmarked cells) it is always assumed that the next call will require maximum, 64 kb/s, bandwidth.
[0042] ATM Switch
[0043] Referring to FIG. 3, an ATM switch 5 , 13 in accordance with one or more aspects of the present invention may include an STM signal processors 33 , an STM call processors 34 , and a various ATM fabric functionality 35 including an STM-to-ATM Translator 38 , ATM Fabric Controller 39 , an output buffer 40 for discarding marked cells in the case of anticipated overflow and/or various ATM routing functions 37 . The call processor may be utilized to process call set-up information as discussed above for in-band signaling, and the signal processor may be utilized as the conventional signal processor in the ATM switch. The translator translates trunk groups/subgroups into virtual paths/virtual circuits in the ATM domain with the assistance of controller 39 . The cells are routed in conjunction with ATM routing circuits 37 . Where cells begin to overflow, the cells in one or more of the buffers may be purged in accordance with the marking above. Where three levels of marking are used, the silence cells are purged before cells with partial silence.
[0044] In operation, it may be desirable to assign the ATM fabric ports to establish various connections in accordance with the STM instructions received as described above. With respect to the incoming ATM signal from the terminal adapter 4 , as described above, it may be desirable to utilize the STM-ATM translator 38 to provide a permanent trunk group/subgroup to VP/VC one-to-one mapping stored in the ATM switch 5 , 13 . Where this mapping is utilized, it may be desirable to define VPI, VCI assignment at the output port.
[0045] Considering the fact that in the ATM domain VPI, VCI numbers have only local significance, it may be desirable to establish a sub-group VP mapping as defined below. We can enumerate all trunk sub-groups in the toll network using Network Switch Numbers (NSN) in a unique fashion. For example, starting with NSN 1 , we list all sub-groups to NSN 2:(1, 2, 1; . . . ; 1, 2, m 1-2 ), etc., and ending with trunk sub-groups from NSN (N−1), to NSN N. With this mapping sub-group (i, j, k) corresponds to virtual path k between switches i and j. This virtual path is identified at switches i and j by the respective VPI values f(i,k) and f(j,k). Note that if there is no ATM layer processing (multiplexing, cross connecting or switching) at the virtual path level between switches i and j, the f(i,k)=f(j,k).
[0046] Now, for a given virtual path we can describe how to establish trunk/VC mapping. We an assume that the maximum number of connections that this virtual path can support is equal to M. M corresponds to the case when all VCs require minimum bandwidth. As an example, the least amount of bandwidth could be required by VCs carrying speech (assuming compression and silence elimination). The VP occupancy status may be illustrated by the following table:
TABLE 1 VP Status Data Virtual Channel Id Busy/Idle Status Call type Usable or Not 1 busy Voice — 2 idle — usable M idle — not
[0047] In exemplary embodiments, the call type status in Table 1 for active VCs may be provided to the ATM switch controller 36 via the STM-ATM translator 38 as discussed above using, for example, the dedicated special VC for this purpose. The last column indicates that not all idle VCs could be available for use. The discussion below explains this situation and proposes how to monitor and update these data.
[0048] In the STM domain, each 64 kb/s trunk carries a single connection. In accordance with our proposal, each connection corresponds to a particular virtual circuit. Depending on the call type, these connections may require a different ATM bandwidth. In spite of bandwidth differences, it may be desirable to establish a one-to-one relationship between assumed M trunks for this sub-group and M potential virtual circuits. To reflect actual bandwidth usage on the virtual path, it may be desirable to utilize a ATM fabric controller 39 to conservatively estimates bandwidth requirements depending on the call type. (The word conservatively refers to silence elimination for voice, which is statistical in nature.)
[0049] Assuming, for example, that 8 kb/s is sufficient to carry a voice call. Then, with the arrival of a voice-band data call (no compression), we update our VP occupancy table, specifying that one more VC is busy carrying a voice-band data call, and designating sevem additional idle/usable VCs with idle/non-usable status. The seven additional idle/usable VC represent the unused VC bandwidth which is not utilized by the voice call i.e., the number of remaining (idle/usable) VCs corresponds to the number of additional voice connections that the virtual path can carry. Thus, the idle capacity has similar and consistent interpretation in both ATM and STM domains, allowing the use of STM RTNR strategy for call routing. In this configuration, it is possible for the ATM switch to accept one more call to a particular virtual path if the remaining bandwidth is at least 64 kb/s.
[0050] While exemplary systems and methods embodying the present invention are shown by way of example, it will be understood, of course, that the invention is not limited to these embodiments. Modifications may be made by those skilled in the art, particularly in light of the foregoing teachings. For example, each of the elements of the aforementioned embodiments may be utilized alone or in combination with elements of the other embodiments. Additionally, although a terminal adapter is shown being connected to an analog phone, the inventions defined by the appended claims is not necessarily so limited. For example, the terminal adapter may be disposed in a PABX of a business. Furthermore, examples of steps that may be performed in the implementation of various aspects of the invention are described in conjunction with the example of a physical embodiment as illustrated in FIG. 1. However, steps in implementing the method of the invention are not limited thereto. Additionally, although the examples have been derived using the ATM protocol, it will be apparent to those skilled in the art that any cell based protocol may also be used.
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This proposal outlines an approach for interfacing Synchronous Transfer Mode (STM) and Asynchronous Transfer Mode (ATM) networks and for transporting voice, fax and voice-band data calls by the ATM network in an efficient manner. In contrast to the well known ATM Variable Bit Rate (VBR) approach, this proposal allows one to transport 64 kb/s traffic efficiently over ATM by re-using STM network signaling and exploiting the standard AAL-1-type adaptation layer (intended for Constant Bite Rate, CBR, services). We use low bit rate encoding algorithms and achieve additional compression for speech by marking cells that do not contain talk spurts. The invention defines specific rules for STM-to-ATM interfacing, including all routing translation, and identifies necessary Terminal Adapter (TA) and ATM switch capabilities. This approach is an advancement over previous inventions that specified network architecture and terminal adapter requirements to provide a graceful transition from an STM network (for example the AT&T long distance network) to an ATM network. Prior art described how to emulate an STM network in the ATM domain, but did not permit for compression and silence elimination and, therefore, did not allow achieving efficiency gains.
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TECHNICAL FIELD OF THE INVENTION
[0001] The present invention relates to a computerized apparatus for simulating an interventional operation, and in particular the effect of using special instruments.
BACKGROUND OF THE INVENTION
[0002] Principles of adult education, tenets of experiential learning, and theories addressing the development of expertise have all underscored the critical role experience plays in the learning process. State-of-the-art simulations can be successfully included in contemporary surgical and medical education to offer trainees and practicing physicians the requisite learning experiences based on these educational underpinnings. All learners can be offered opportunities to acquire the essential skills and to achieve specified competency levels based on standardized learning experiences. Simulations can be used to facilitate learning through the evaluation of performance and provision of immediate, individualized, and detailed feedback. Simulations offer controlled settings that allow repetition until the defined performance levels are achieved, decrease stress levels of learners, increase the confidence levels of learners, and increase safety in real settings by assuring the achievement of technical competence prior to work on patients. Practicing physicians can improve their skills and can learn new procedures emerging as a result of advances in science and technology through educational interventions involving the use of simulations. In addition, the use of simulations can help address practical issues, such as the demands on faculty time, by providing trainees the opportunities for independent learning and practice. The current emphasis on accountability and on assurance of the quality of health care may also be addressed through the use of such simulations and data on outcomes can be used to assure the public of the competence of physicians.
[0003] Simulations should be considered an essential part of every contemporary educational program that addresses technical skills development. They can be used to ensure effective teaching and learning, to provide valid and reliable means of assessment of the skills of learners, to yield information on specific weaknesses that require improvement, and to create individual proinstruction sets of the technical ability of learners. In order to achieve the desired results, specific curricula should be developed based on principles of adult education, experiential learning, and effective feedback. Such simulations may also be used in programs of continuing professional education and certification. The initial investment of resources needed for the development and acquisition of simulations and for the creation of training programs that incorporate them effectively in educational models is readily offset by the numerous advantages resulting from expeditious performance of procedures in the operating room, enhancement of patient safety, and decrease in the faculty time needed to teach learners various technical skills. Such simulations may also be used to assess the effectiveness of educational efforts and even to select individuals for training. Thus, the simulations have the potential to make a major impact on programs of surgical and medical education of the future.
[0004] As a result of the rapid developments within the computer technique, simulations, especially for the purpose of surgical and medical education, have improved considerably. However, the presently known apparatus and methods do not allow a full range simulation of different instruments used.
[0005] Prior art does not suggest or give a hint for simulating different instruments according to the present invention.
[0006] U.S. Pat. No. 4,907,973 discloses a medical investigative system in which a person interacts with the system to interject information that is utilized by the system to establish non-restricted environmental modelling of the realities of surrogate conditions to be encountered with invasive or semi-invasive procedures. This is accomplished by video display of simulated internal conditions that appear life-like, as well as by display of monitor data including, for example, blood pressure, respiration, heart beat rate and the like. The document mentions blood flow but not blood flow changes and how such a simulation is accomplished.
[0007] WO 01/88882 relates to a method and a system for simulating the minimally invasive medical procedure of bilio-pancreatic duodenoscopy. The system is designed to simulate the actual medical procedure of bilio-pancreatic duodenoscopy as closely as possible by providing both a simulated medical instrument, and tactile and visual feedback as the simulated procedure is performed on the simulated patient. Particularly preferred features include a multi-path solution for virtual navigation in a complex anatomy. In addition, the system and method optionally and more preferably incorporate the effect of dynamic contrast injection of dye into the papilla for fluoroscopy. The injection of such dye, and the subsequent visualization of the bilio-pancreatic organ system in the presence of the duodenoscope, must be accurately simulated in terms of accurate visual feedback. In addition, the bilio-pancreatic organ system is optionally and more preferably modeled as a plurality of splines, most preferably arranged as a tree of splines or other branched structure. Thus, the system and method provide a complete solution to the complex and difficult problem of training students in bilio-pancreatic duodenoscopy procedures. The document mentions that in step 3, the digitized images are preferably selected for clarity and lack of visual artefacts, and are then stored in a texture-mapping database. More preferably, the digitized images are enhanced before being stored. Most preferably, the texture mapping also include animation. Such animation could simulate effects such as the flow of biological fluids such as blood, flowing downward due to the influence of gravity. Neither this document mentions the flow change or how it is accomplished.
SUMMARY OF THE INVENTION
[0008] The main object of the preferred embodiment of the invention is to present a novel and effective system for a real-time simulation of affect of expanding instruments in simulated vessels, preferably in cardiovascular or endovascular diagnostic or interventional procedures. Another object of the invention is to simulate the flow change of for example blood or other fluid in a simulated vessel.
[0009] Thus, an interventional procedure simulation system according to the present invention comprises a control unit and an interface unit, the control unit communicating with the interface unit to simulate handling of at least one instrument interfaced by the interface unit. The instrument is a tool expandable in a simulated vessel, whereby when the tool is expanded, geometry of the vessel changes resulting in a blood flow change. The simulated vessels are interconnected in a hierarchical structure and the blood flow change effects blood flow changes in adjacent simulated vessels.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] In the following, the invention will be further described in a non-limiting way with reference to the accompanying drawings in which:
[0011] FIG. 1 schematically illustrates a block diagram according to one embodiment of the invention,
[0012] FIG. 2 is a schematic view of an interface device,
[0013] FIG. 3 is a schematic view of a simulated instrument,
[0014] FIGS. 4-6 are fluoroscopic images illustrating sequences using a balloon and stent,
[0015] FIGS. 7-10 are fluoroscopic images illustrating sequences using a guide catheter,
[0016] FIGS. 11-13 are fluoroscopic images illustrating sequences using a distal protection,
[0017] FIG. 14 illustrates a schematic vessel structure,
[0018] FIG. 15 is a structured vessel hierarchy according to FIG. 14 ,
[0019] FIG. 16 is a model for radius calculation, in which R(p) is shown for (from top to bottom): q=0, q=1, q=2 (p 0 =4),
[0020] FIG. 17 is another model for radius calculation, in which R(p) is shown for p 0 =2, 4, 6, 8 (from left to right) (q=1), and
[0021] FIG. 18 is another model for radius calculation, in which R(p) is shown for p 0 =2, 4, 6, 8 (from left to right) (q=2).
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0022] One exemplary embodiment of a simulation apparatus according to the invention is schematically illustrated in FIG. 1 . The apparatus 100 comprises a computer unit 110 and an interface device 120 . The computer unit 110 can be a conventional PC or similar, or a unit integrated with the interface device 120 . The computer unit according to this embodiment communicates with a display unit 111 , an input device 112 such as a keyboard and a mouse, and a communication interface (not shown).
[0023] The interface device 120 , described in a parallel application, entitled “AN INTERVENTIONAL SIMULATION DEVICE” (SE 0203568-1) by the same applicant and incorporation herein through reference, is arranged to receive a number of instruments 121 - 123 . The control system, described in a parallel application, entitled “AN INTERVENTIONAL SIMULATION CONTROL SYSTEM” (SE 0203567-3) by the same applicant and incorporation herein through reference, is arranged to simulate interventional procedures.
[0024] However, the invention is not limited to a system comprising the above mentioned control system and interface devices. The teachings of the invention can be employed in any system able of simulation of self-expanding instruments.
[0025] A 3D geometry can be constructed in different ways:
They can be modeled in a 3D modeling software, i.e. from scratch using anatomy books, video clips, etc as references only. They can be reconstructed from real patient data, e.g. obtained through scans 130 with CT, MRI, Ultrasound, fluoroscope, etc.
[0028] An interface device 200 , schematically illustrated in FIG. 2 , as a preferred embodiment, is arranged to receive a number of instruments, dummies or real, preferably at least two instruments. The device comprises a number of moveable carriages 216 A- 216 C corresponding to the number of the instruments, a common track 220 , and an interconnecting member 226 provided as a telescopic tube. The interconnecting member 226 interconnects the carriages 216 A- 216 C serially. Each carriage is provided with an opening for enabling reception of the instruments. Each carriage 216 A- 216 C further comprises members to receive and lock at least one of the instruments, and members for receiving a movement from the instrument and generating a force, which is fed back to the instrument with respect to a simulation characteristic. Preferably, each carriage comprises a detecting arrangement for detecting the type of the instrument inserted through the interconnecting member. The interface device is connected to the control unit (PC) to measure the movement of each carriage and regulate the movement by means of a speed regulator and a distance regulator. Each carriage is connected with a gear belt transmission for driving along the track 220 . Each carriage is provided with a crank block, which is arranged on a torque wheel. The crank block is provided with a mating surface, which is pressed towards a collet that grips the instrument wire. Moreover, each carriage is arranged with an outlet, which is provided with a detecting member, which detects presence of an instrument in the carriage. The detecting member is arranged to detect the thickness of each instrument. The optical sensor detects presence of an instrument in the carriage. The control unit measures a longitudinal movement and a movement of rotation, of the instrument and gives force-feedback in the longitudinal direction and in the direction of rotation, of the instrument according to received force and torque. A locking member is arranged to clamp an instrument, which instrument is attached to a central wall. The locking member comprises a torque wheel, which is arranged in the central wall. The crank block is provided inside the torque wheel, which crank block moves in longitudinal direction. The crank block is fixed in the direction of rotation.
[0029] Preferably, the system simulates the way different types of self-expanding tools behave. The self-expanding tool consists of the tool itself and a covering sheath (tube). As the sheath is retracted, the tool itself expands to its “natural” shape. In some cases, it is also possible to push a sheath back to cover the tool again.
EXAMPLE 1: SELF-EXPANDABLE STENT
[0030] The stent is pressed on top of a hollow tube, which runs on top of a wire, and covered, by a sheath. The stent is not attached to the underlying tube. When the covering sheath is retracted, the stent opens gradually and takes a predefined diameter (in a vessel this diameter is the maximum, and will be less if the vessel walls press the stent together). When the sheath is fully retracted, the stent will be totally detached from the sheath and underlying tube, and pressed against the vessel walls. There is now no way of retrieving the stent itself.
EXAMPLE 2: DISTAL PROTECTION DEVICE (DPD)
[0031] A DPD 30 as illustrated in FIG. 3 , is a “double cone” 31 and 32 attached at two ends to a wire 33 , and covered by a sheath (not shown). The distal part of the “cone” is a fine net 31 , which is attended to catch particles that can be set free during an intervention. The proximal part of the “cone” is totally open. When the sheath is retracted, the cone takes its “natural” shape—widest at the middle. Since it is attached to the underlying wire, the sheath can be pushed back to again cover the “cone”.
[0032] In the following, the invention will be described in conjunction with a number of non-limiting examples:
FIGS. 4-6 illustrate sequences of a self-expanding instrument, in this example a self-expanding stent. In case of self-expandable stents, they are covered with a sheath, which is then retracted and the stent expands to a given size (but as it hits the vessel wall the final size will be dependent of the vessel “stiffness” and the properties of the stent itself). The properties of the stent, both visually, the way it expands and the effects it has on the vessel are simulated. The vessel can also be post dilated with a “regular” balloon afterwards. In FIG. 4 a self-expandable stent is in place in a vessel but not deployed, in FIG. 5 the sheath covering the stent is partially retracted and in FIG. 6 the sheath is fully retracted and stent deployed (not connected to the tool). The simulator program has a number of initial values: a rest expansion diameter for the self expanding instrument expansion-diameter, the vessel initial inner diameter (at the simulated part), spring constant for the self expansion instrument and a vessel stiffness. These parameters determine how the simulator sets the boundaries for the expansion of the instrument and (simulated part) of the vessel. If a sheath is used, also its diameter must be initiated.
[0034] A balloon and a stent can also be used in same way; the balloon (also for the stent) interacts with a vessel, which expands. The blood flow changes, and so does the contrast if injected. The stent is simulated in such a way that it is visible and stays in place as the balloon is deflated. It is also possible to enter with a larger balloon and inflate it again. This will influence both the stent and the vessel, so-called post dilatation. It is also possible to first inflate a balloon, before using a stent, so-called pre dilatation. Simulation is achieved by using force feedback, whereby a tight lesion is felt, when going through with a “large” balloon.
[0035] According to the most preferred embodiment of the invention, the vessels are arranged in a hierarchy. All vessels are provided in a database having a structured hierarchy as illustrated in FIGS. 14 and 15 , which tells how vessels connect. The change of the blood flow in one vessel affects the flow in other vessels in the hierarchy.
[0036] The system simulates the balloon instrument and the effects it has on the surrounding tubular organ, e.g. a vessel or a duct.
[0037] A vessel consists of a tubular geometry and has its specific stiffness. This stiffness can be different for different vessels and different parts of a vessel. Specifically the parts called lesions (narrowing of a vessel) may have different stiffness than the neighboring vessel parts.
[0038] The geometry of a vessel affects the flow of the fluids (blood) inside. A lesion will decrease the flow through the rest of the vessel tree beyond that point.
[0039] A balloon, for example, is used to open up lesions, thus expanding a narrow section of a vessel and increasing the flow. The balloon is inflated under high pressure. Each specific balloon has its predefined size (diameter and length). The resulting diameter will however depend on the amount of pressure applied externally by the physician inflating the balloon and the internal pressure from the vessel walls.
[0040] The system calculates the flow through the vessel-tree as a result of its geometry. Narrow sections will result in lower flow. Every time the geometry of the vessel tree is changed or objects block (even partially), the flow is recalculated.
[0041] The flow calculations can be made in the same way as an electrical resistive network is solved. Potentials correspond to pressure, currents correspond to flow and electrical resistance corresponds to fluid resistance. The top of the fluid network is in the left ventricle of the heart, where the highest pressure is, and the bottom of the network is in the veins connecting to the right atrium of the heart, where the potential is close to zero. The intermediate vessels, i.e. all vessel branches in the tree, have a calculated flow resistance depending on their diameter and their length. The algorithm for flow calculation calculates recursively through the tree until flow and pressure in all branches are solved.
[0042] The system calculates the effects a balloon has on the surrounding vessel walls. Depending on the size (diameter and length) of the balloon, and the pressure applied the vessel wall will be affected differently. The same balloon, using the same pressure, will also affect the same size of vessel differently if the vessel has different stiffness. The same balloon with different pressure will affect the same vessel differently.
[0043] Following is an exemplary method of simulating the flow change. Data on vessel and balloon characteristics are stored in a storage unit in the computer. The pressure data are fetched from the interface device.
[0044] The algorithm for the vessel diameter change works in the following manner (simplified): The balloon is inflated with a pressurizer, a pump. The balloon diameter is a function of the pump pressure when the balloon diameter is less than the vessel diameter and the vessel is unaffected (but the flow is updated according to below method, since the cross section area changes). When the balloon diameter is equal to or larger than the vessel diameter, the vessel diameter starts to increase. The balloon pressure applies on the vessel wall and causes internal strain in the vessel. This in turn makes the vessel wall expand depending on its stiffness, resulting in the vessel radius increase, which gives a new vessel wall area, causing new internal forces in the vessel wall, and so on.
[0045] An exemplary model used in the computer unit has the form:
R ( p ) = { r N ( p ) if r N ( p ) < r v r v + ( r N ( p ) - r v ) k B k B + k V tanh q [ p p 0 ] else
where p is the pressure in the balloon, R(p) is the actual radius of the balloon in the vessel, r x (p) is the size of the balloon in free space at a given pressure, and r v is the initial radius of the vessel q is an integer determining the shape of the function (see FIG. 16 ) and p 0 is the threshold value of the pressure (see FIGS. 17 and 18 ). Finally, k B and k v determine the stiffness of the balloon and the vessel, respectively. R(p) is also heavily filtered to obtain a slow expansion. Note that the balloon grows freely until it has the size of the vessel.
[0046] It is possible to fix the value of q once and then having a default value of p 0 for special cases only.
[0047] During the balloon inflation, the flow will be affected by the balloon blockage (see FIG. 8 , total blockage).
[0048] When the balloon is deflated a permanent change of the vessel geometry will occur, thus resulting in a change of flow.
[0049] instead of a balloon a self-expanding stent can also be used to open the vessel geometry, and alter the flow.
[0050] The procedure illustrated in FIGS. 7-10 , is done in such a way that first a guide catheter and guide wire are advanced to access either the right or left coronary vessel tree. Contrast is then injected through the catheter to locate the lesion/stenosis. The view can be changed to obtain a perfect visualization of the lesion. Images can also be exported or used by a separate QCA (Qualitative C Assessment) program, for length and width measurement. Then the user can decide what sizes of balloon/stent he/she wants to use. (Typically, some cine loops are recorded before and after balloon dilatation/stenting.) A thin guide wire (coronary wire) is first advanced through the catheter and into the vessel tree. The tip of the wire can be shaped in an angle (user selectable), and the wire is then steered through the vessel tree by rotating the wire, and pulling/pushing to find the right way past the lesion. The balloon/stent is then advanced on top of the wire, and positioned in the right place using the radioopaque markers. Contrast can be injected to see that it is positioned in the right place. Finally, the balloon/stent is inflated, held for some time, and then deflated. All the steps are simulated and can be performed as in real life.
[0051] A distal protection device stops emboli from moving further and block very small vessels (which can be devastating in the brain). A filter “basket” can then be used attached to a wire and at first covered with a sheath. The wire and sheath is positioned past the lesion, and then the sheath is retracted, leaving the basket as a protection for when the lesion is dilated. Afterwards a recovery sheath is advanced to close the basket and the two are together retracted. The behavior of the distal protection device is simulated, comprising how one handles it and the visible characteristics. Other types of protection devices are also possible to simulate, for example balloons that block the flow while dilating. Sequences are illustrated in FIGS. 11-13 , showing:
FIG. 11A distal protection device is in place in a vessel, sheath-covering filter partially retracted; FIG. 12 the sheath is retracted, markers at the “base” of filter starting to “expand”; FIG. 13 the sheath retracted even more.
[0055] Note that the filter itself, in this case, is not visible on a fluoroscopic image. Only the marker points are. The sequence above can be reversed, since the filter stays connected to the wire.
[0056] The invention is not limited to the shown embodiments but can be varied in a number of ways without departing from the scope of the appended claims and the arrangement and the method can be implemented in various ways depending on application, functional units, needs and requirements etc.
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The present invention relates to an interventional procedure simulation system and method, comprising a control unit and an interface unit, said control unit communicating with said interface unit to simulate handling of at least one instrument interfaced by said interface unit. The control unit comprises a database of vessels having hierarchy structure, each vessel having a diameter and a stiffness, and said instrument being a tool expendable in a simulated vessel. When the tool is expanded, a geometry of said vessel changes resulting in a fluid flow change.
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STATEMENT REGARDING GOVERNMENT SUPPORT
[0001] This invention was made with government support under Contract No. FA8650-09-D-D00021 awarded by the United States Air Force. The government has certain rights in this invention.
BACKGROUND
[0002] Gas turbine engines typically include a compressor section, a combustor section, and a turbine section. During operation, air is pressurized in the compressor section, and mixed with fuel and burned in the combustor section to generate hot combustion gases. The hot combustion gases are communicated through the turbine section, which extracts energy from the hot combustion gases to power the compressor section and other gas turbine engine loads.
[0003] Both the compressor and turbine sections include alternating arrays of rotating blades and stationary vanes that extend into a core airflow path of the gas turbine engine. During a surge condition, wherein fluid in the core airflow path flows opposite the intended direction, it is possible for the stationary vanes to move axially and cause damage to adjacent components. One example system for limiting vane movement is in U.S. Pat. No. 7,854,586, assigned to United Technologies Corporation and hereby incorporated by reference in its entirety. In the '586 patent, an arm 94 , which is formed separately from an engine case 28 , is attached to the case 28 to prevent undesired vane movement.
SUMMARY
[0004] One exemplary aspect of this disclosure relates to an assembly for a gas turbine engine having an engine axis. The assembly includes a case including an integrally formed projection configured to extend transverse to the engine axis. The assembly further includes an engine component including a flange configured for contact with the projection to limit motion of the component along the engine axis.
[0005] In a further non-limiting embodiment of the foregoing assembly, the case and the projection are monolithically formed.
[0006] In a further non-limiting embodiment of the foregoing assembly, the engine component includes at least one vane.
[0007] In a further non-limiting embodiment of the foregoing assembly, the at least one vane includes a plurality of variable area vanes.
[0008] In a further non-limiting embodiment of the foregoing assembly, each vane includes a respective platform having a respective flange, and each of the flanges contacts the projection.
[0009] In a further non-limiting embodiment of the foregoing assembly, the assembly further includes a plurality of rotor blades downstream of the vanes.
[0010] In a further non-limiting embodiment of the foregoing assembly, an aft surface of the flange is configured to contact a fore surface of the projection.
[0011] In a further non-limiting embodiment of the foregoing assembly, the aft surface of the flange and the fore surface of the projection are configured for contacting one another along an inclined interface relative to the engine axis.
[0012] In a further non-limiting embodiment of the foregoing assembly, the inclined interface is inclined at an acute angle relative to the engine axis.
[0013] In a further non-limiting embodiment of the foregoing assembly, the case is configured to be mounted adjacent a low pressure compressor and a high pressure compressor of the engine.
[0014] Another exemplary aspect of this disclosure relates to a case for a gas turbine engine having an engine axis. The case includes a stop monolithically formed with the case and configured to circumferentially extend about the engine axis with a fore surface of the stop oriented at an angle relative to the engine axis.
[0015] In a further non-limiting embodiment of the foregoing case, wherein the stop extends from a main body of the case to a free end.
[0016] In a further non-limiting embodiment of the foregoing case, the stop is configured to contact a flange of an engine component to limit axial movement thereof.
[0017] In a further non-limiting embodiment of the foregoing case, the stop is oriented at an acute angle relative to the engine axis.
[0018] Yet another exemplary aspect of this disclosure relates to a component for a gas turbine engine having an engine axis. The component includes an inner platform including a flange. The flange projects from a radially inner surface of the inner platform, and the flange is configured to be mounted in the engine with an aft surface thereof oriented at an angle relative to the engine axis.
[0019] In a further non-limiting embodiment of the foregoing component, the component is a variable area vane.
[0020] In a further non-limiting embodiment of the foregoing component, the vane includes an airfoil section, a root section, and a bushing adjacent the root section. The bushing is configured to radially retain the root section while allowing rotation of the root section.
[0021] In a further non-limiting embodiment of the foregoing component, the root section is configured for rotation about an axis normal to the engine axis.
[0022] In a further non-limiting embodiment of the foregoing component, the flange is configured to contact a retainer of a case.
[0023] The embodiments, examples and alternatives of the preceding paragraphs, the claims, or the following description and drawings, including any of their various aspects or respective individual features, may be taken independently or in any combination. Features described in connection with one embodiment are applicable to all embodiments, unless such features are incompatible.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The drawings can be briefly described as follows:
[0025] FIG. 1 schematically illustrates an example gas turbine engine.
[0026] FIG. 2 is a partial, cross-sectional view of a section of an example gas turbine engine.
[0027] FIG. 3 is a close-up view of the encircled area in FIG. 2 .
DETAILED DESCRIPTION
[0028] FIG. 1 schematically illustrates a gas turbine engine 20 . The gas turbine engine 20 is disclosed herein as a two-spool turbofan that generally incorporates a fan section 22 , a compressor section 24 , a combustor section 26 and a turbine section 28 . Alternative engines might include an augmentor section (not shown) among other systems or features. The fan section 22 drives air along a bypass flow path B in a bypass duct defined within a nacelle 15 , while the compressor section 24 drives air along a core airflow path C for compression and communication into the combustor section 26 then expansion through the turbine section 28 . Although depicted as a two-spool turbofan gas turbine engine in the disclosed non-limiting embodiment, it should be understood that the concepts described herein are not limited to use with two-spool turbofans as the teachings may be applied to other types of turbine engines including three-spool architectures.
[0029] The exemplary engine 20 generally includes a low speed spool 30 and a high speed spool 32 mounted for rotation about an engine central longitudinal axis A relative to an engine static structure 36 via several bearing systems 38 . It should be understood that various bearing systems 38 at various locations may alternatively or additionally be provided, and the location of bearing systems 38 may be varied as appropriate to the application.
[0030] The low speed spool 30 generally includes an inner shaft 40 that interconnects a fan 42 , a first (or low) pressure compressor 44 and a first (or low) pressure turbine 46 . The inner shaft 40 is connected to the fan 42 through a speed change mechanism, which in exemplary gas turbine engine 20 is illustrated as a geared architecture 48 to drive the fan 42 at a lower speed than the low speed spool 30 . The high speed spool 32 includes an outer shaft 50 that interconnects a second (or high) pressure compressor 52 and a second (or high) pressure turbine 54 . A combustor 56 is arranged in exemplary gas turbine 20 between the high pressure compressor 52 and the high pressure turbine 54 . A mid-turbine frame 57 of the engine static structure 36 is arranged generally between the high pressure turbine 54 and the low pressure turbine 46 . The mid-turbine frame 57 further supports bearing systems 38 in the turbine section 28 . The inner shaft 40 and the outer shaft 50 are concentric and rotate via bearing systems 38 about the engine central longitudinal axis A which is collinear with their longitudinal axes.
[0031] The core airflow is compressed by the low pressure compressor 44 then the high pressure compressor 52 , mixed and burned with fuel in the combustor 56 , then expanded over the high pressure turbine 54 and low pressure turbine 46 . The mid-turbine frame 57 includes airfoils 59 which are in the core airflow path C. The turbines 46 , 54 rotationally drive the respective low speed spool 30 and high speed spool 32 in response to the expansion. It will be appreciated that each of the positions of the fan section 22 , compressor section 24 , combustor section 26 , turbine section 28 , and fan drive gear system 48 may be varied. For example, gear system 48 may be located aft of combustor section 26 or even aft of turbine section 28 , and fan section 22 may be positioned forward or aft of the location of gear system 48 .
[0032] The engine 20 in one example is a high-bypass geared aircraft engine. In a further example, the engine 20 bypass ratio is greater than about six (6), with an example embodiment being greater than about ten (10), the geared architecture 48 is an epicyclic gear train, such as a planetary gear system or other gear system, with a gear reduction ratio of greater than about 2 . 3 and the low pressure turbine 46 has a pressure ratio that is greater than about five. In one disclosed embodiment, the engine 20 bypass ratio is greater than about ten (10:1), the fan diameter is significantly larger than that of the low pressure compressor 44 , and the low pressure turbine 46 has a pressure ratio that is greater than about five 5:1. Low pressure turbine 46 pressure ratio is pressure measured prior to inlet of low pressure turbine 46 as related to the pressure at the outlet of the low pressure turbine 46 prior to an exhaust nozzle. The geared architecture 48 may be an epicycle gear train, such as a planetary gear system or other gear system, with a gear reduction ratio of greater than about 2.3:1. It should be understood, however, that the above parameters are only exemplary of one embodiment of a geared architecture engine and that the present invention is applicable to other gas turbine engines including direct drive turbofans.
[0033] FIG. 2 is a partial, schematic view of a section 60 of the engine 20 . In this example, the section 60 includes an array of vanes 62 and an array of blades 64 downstream of the vanes 62 . The vanes 62 each include an airfoil section 66 projecting into the core airflow path C, and a root section 68 . The vanes 62 in this example are variable area vanes. That is, the vanes 62 are rotatable about an axis X, which extends parallel to a radial direction R (which is normal to the engine central longitudinal axis A) to vary the effective area of the core airflow path C. The root section 68 is rotatable relative to a bushing 70 , which also radially retains the root section 68 . The bushing 70 is provided within an inner platform 72 . While variable area vanes are shown, this disclosure extends to other types of vanes.
[0034] The blades 64 each include an airfoil section 74 projecting into the core airflow path C from an inner platform 76 . The inner platform 76 is connected to a disk 78 , which is configured to rotate about the engine central longitudinal axis A.
[0035] In order to prevent unwanted axial movement of the vanes 62 , a case 80 of the engine 20 includes a retainer 82 . In this example, the retainer 82 includes a projection 84 which functions as a retainer or stop as further discussed below. The case 80 is an intermediate case in this example, and is located between the low pressure compressor 44 and the high pressure compressor 52 . This disclosure is not limited to intermediate cases, however.
[0036] In accordance with various embodiments, the case 80 is integrally or monolithically formed with the retainer 82 . That is, the case 80 and the projection 84 can be formed as a single, monolithic structure, without mechanical joints or seams In one example, the case 80 and the projection 84 are formed together as part of the same casting process. While FIG. 2 only illustrates the case 80 in cross section, the case 80 and the projection 84 circumferentially extend about the engine central longitudinal axis A. In one example, the case 80 and the projection 84 are annular, and extend around the entirety of the engine central longitudinal axis A. It is also possible to scallop adjacent sections of the case 80 , which may provide a weight reduction. That is, a single projection 84 may contact more than one vane 62 .
[0037] The projection 84 contacts a flange 86 projecting from a radially inner surface 88 of the inner platforms 72 to limit vane movement. The projection 84 , in this example, extends generally in an aft direction (to the right in FIG. 2 ) from a main body 83 of the case 80 to a free end 85 . Further, as illustrated in FIG. 3 , the projection 84 includes a fore surface 90 and an aft surface 92 . The fore surface 90 is inclined at an angle A l relative to the engine central longitudinal axis A.
[0038] The flange 86 includes a fore surface 94 and an aft surface 96 , which is also inclined at the angle A 1 . The angle A 1 , in one example, is non-parallel with the engine central longitudinal axis A. That is, A 1 is greater than 0° and less than 90°. In one example, the angle A l is approximately 60°.
[0039] As illustrated, the fore surface 90 of the projection 84 is in direct contact with the aft surface 96 of the flange 86 . The surfaces 90 and 96 provide a bearing surface between the flange 86 and the projection 84 , which prevents the vanes 62 from moving in an aft direction (to the right in FIG. 2 ) during a surge condition, for example, and thus prevents damage to adjacent engine components, such as the blades 64 .
[0040] In a surge condition, the flow of fluid within the core airflow path C reverses. A reversal of flow is illustrated in phantom at S in FIG. 2 . In a surge condition, the vanes 62 may deflect in a fore direction (to the left in FIG. 2 ), such that a fore face 98 of the inner platform 72 contacts an aft face 100 of the case 80 . Absent retaining projection 84 , such contact between faces 98 , 100 may cause the vanes 62 to subsequently move in an axially aft direction toward the rotor blades 64 , which may cause damage to the rotor blades 64 and other engine components.
[0041] The retainer 82 prevents unwanted axial movement of the vane 62 , and thus prevents the vane 62 from damaging the engine during a surge condition. Further, because the retaining projection 84 is monolithically formed with the case 80 , ease of assembly is increased, and weight is reduced (due to the elimination of additional parts, scalloping adjacent case sections, etc.). The inclined surfaces 90 , 96 also increase the ease of aligning the flange 86 and projection 84 during assembly, during which the vane 62 may be loaded from a radial outer location.
[0042] It should be understood that terms such as “fore,” “aft,” “axial,” and “radial,” are used above with reference to the normal operational attitude of the engine 20 . Further, these terms have been used herein for purposes of explanation, and should not be considered otherwise limiting. Terms such as “approximately” are not intended to be boundaryless terms, and should be interpreted consistent with the way one skilled in the art would interpret the term.
[0043] Although the different examples have the specific components shown in the illustrations, embodiments of this disclosure are not limited to those particular combinations. It is possible to use some of the components or features from one of the examples in combination with features or components from another one of the examples.
[0044] One of ordinary skill in this art would understand that the above-described embodiments are exemplary and non-limiting. That is, modifications of this disclosure would come within the scope of the claims. Accordingly, the following claims should be studied to determine their true scope and content.
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One exemplary aspect of this disclosure relates to an assembly for a gas turbine engine having an engine axis. The assembly includes a case including an integrally formed projection configured to extend transverse to the engine axis. The assembly further includes an engine component including a flange configured for contact with the projection to limit motion of the component along the engine axis.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. patent application Ser. No. 11/025,623 filed on Dec. 29, 2004 and claims priority to U. S. provisional patent application Ser. No. 60/600,845 filed on Aug. 12, 2004.
FIELD OF THE INVENTION
[0002] The invention is related to an insulated fiber cement siding.
BACKGROUND OF THE INVENTION
[0003] A new category of lap siding, made from fiber cement or composite wood materials, has been introduced into the residential and light commercial siding market during the past ten or more years. It has replaced a large portion of the wafer board siding market, which has been devastated by huge warranty claims and lawsuits resulting from delamination and surface irregularity problems.
[0004] Fiber cement siding has a number of excellent attributes which are derived from its fiber cement base. Painted fiber cement looks and feels like wood. It is strong and has good impact resistance and it will not rot. It has a Class 1(A) fire rating and requires less frequent painting than wood siding. It will withstand termite attacks. Similarly composite wood siding has many advantages.
[0005] Fiber cement is available in at least 16 different faces that range in exposures from 4 inches to 10.75 inches. The panels are approximately 5/16 inch thick and are generally 12 feet in length. They are packaged for shipment and storage in units that weigh roughly 5,000 pounds.
[0006] Fiber cement panels are much heavier than wood and are hard to cut requiring diamond tipped saw blades or a mechanical shear. Composite wood siding can also be difficult to work with. For example, a standard 12 foot length of the most popular 8¼ inch fiber cement lap siding weighs 20.6 pounds per piece. Moreover, installers report that it is both difficult and time consuming to install. Fiber cement lap siding panels, as well as wood composite siding panels, are installed starting at the bottom of a wall. The first course is positioned with a starter strip and is then blind nailed in the 1¼ inch high overlap area at the top of the panel (see FIG. 1 ). The next panel is installed so that the bottom 1¼ inch overlaps the piece that it is covering. This overlap is maintained on each successive course to give the siding the desired lapped siding appearance. The relative height of each panel must be meticulously measured and aligned before the panel can be fastened to each subsequent panel. If any panel is installed incorrectly the entire wall will thereafter be miss-spaced.
[0007] Current fiber cement lap siding has a very shallow 5/16 inch shadow line. The shadow line, in the case of this siding, is dictated by the 5/16 inch base material thickness. In recent years, to satisfy customer demand for the impressive appearance that is afforded by more attractive and dramatic shadow lines virtually all residential siding manufacturers have gradually increased their shadow lines from ½ inch and ⅝ inch to ¾ inch and 1 inch.
SUMMARY OF THE INVENTION
[0008] Disclosed herein are embodiments of foam backing panels for use with lap siding and configured for mounting on a building. One such embodiment of the foam backing panel comprises a rear face configured to contact the building, a front face configured for attachment to the lap siding, alignment means for aligning the lap siding relative to the building, means for providing a shadow line, opposing vertical side edges, a top face extending between a top edge of the front face and rear face and a bottom face extending between a bottom edge of the front face and rear face.
[0009] Also disclosed herein are embodiments of lap board assemblies. One such assembly comprises the foam backing panel described above, with the alignment means comprising alignment ribs extending a width of the front face, the alignment ribs spaced equidistant from the bottom edge to the top edge of the front face. A plurality of lap boards is configured to attach to the foam backing panel, each lap board having a top edge and a bottom edge, the top edge configured to align with one of the alignment ribs such that the bottom edge extends beyond an adjacent alignment rib.
[0010] Also disclosed herein are methods of making the backing and lap board. One such method comprises providing a lap board and joining a porous, closed cell foam to a substantial portion of a major surface of the fiber cement substrate, the foam providing a drainage path through cells throughout the foam.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The description herein makes reference to the accompanying drawings wherein like reference numerals refer to like parts throughout the several views, and wherein:
[0012] FIG. 1 is a sectional view of a prior art fiber cement panel installation;
[0013] FIG. 2 is a plan view of a contoured alignment installation board according to a first preferred embodiment of the present invention;
[0014] FIG. 2 a is a portion of the installation board shown in FIG. 2 featuring interlocking tabs;
[0015] FIG. 3 is a sectional view of a fiber cement or wood composite installation using a first preferred method of installation;
[0016] FIG. 4 is a rear perspective view of the installation board of FIG. 2 ;
[0017] FIG. 5 is a plan view of an installation board according to a first preferred embodiment of the present invention attached to a wall;
[0018] FIG. 6 is a plan view of an installation board on a wall;
[0019] FIG. 7 is a sectional view of the installation board illustrating the feature of a ship lap utilized to attach multiple EPS foam backers or other foam material backers when practicing the method of the first preferred embodiment of the present invention;
[0020] FIG. 7 a is a sectional view of an upper ship lap joint;
[0021] FIG. 7 b is a sectional view of a lower ship lap joint;
[0022] FIG. 8 a is a sectional view of the fiber cement board of the prior art panel;
[0023] FIGS. 8 b - 8 d are sectional views of fiber cement boards having various sized shadow lines;
[0024] FIG. 9 is a second preferred embodiment of a method to install a fiber cement panel;
[0025] FIG. 10 a shows the cement board in FIG. 8 b installed over an installation board of the present invention;
[0026] FIG. 10 b shows the cement board in FIG. 8 c installed over an installation board of the present invention;
[0027] FIG. 10 c shows the cement board in FIG. 8 d installed over an installation board of the present invention;
[0028] FIG. 11 illustrates the improved fiber cement or wood composite panel utilizing an installation method using a cement starter board strip;
[0029] FIG. 12 is a sectional view of a starter board strip having a foam backer; and
[0030] FIG. 13 illustrates a method for installing a first and second layer of fiber cement or wood composite panels.
DETAILED DESCRIPTION
[0031] The invention outlined hereinafter addresses the concerns of the aforementioned shortcomings or limitations of current fiber cement siding 10 .
[0032] A shape molded, extruded or wire cut foam board 12 has been developed to serve as a combination installation/alignment tool and an insulation board. This rectangular board 12 , shown in FIG. 2 is designed to work with 1¼ inch trim accessories. The board's 12 exterior dimensions will vary depending upon the profile it has been designed to incorporate, see FIG. 3 .
[0033] With reference to FIG. 2 there is shown a plan view of a contoured foam alignment backer utilized with the installation method of the first preferred embodiment. Installation and alignment foam board 12 includes a plurality or registration of alignment ribs 14 positioned longitudinally across board 12 . Alignment board 12 further includes interlocking tabs 16 which interlock into grooves or slots 18 . As illustrated in FIG. 2 a , and in the preferred embodiment, this construction is a dovetail arrangement 16 , 18 . It is understood that the dovetail arrangement could be used with any type of siding product, including composite siding and the like where it is beneficial to attach adjacent foam panels.
[0034] Typical fiber cement lap siding panels 10 are available in 12 foot lengths and heights ranging from 5¼ inches to 12 inches. However, the foam boards 12 are designed specifically for a given profile height and face such as, Dutch lap, flat, beaded, etc. Each foam board 12 generally is designed to incorporate between four and twelve courses of a given fiber cement lap siding 10 . Spacing between alignment ribs 14 may vary dependent upon a particular fiber cement siding panel 10 being used. Further size changes will naturally come with market requirements. Various materials may also be substituted for the fiber cement lap siding panels 10 .
[0035] One commercially available material is an engineered wood product coated with special binders to add strength and moisture resistance; and further treated with a zinc borate-based treatment to resist fungal decay and termites. This product is available under the name of LP SmartSide® manufactured by LP Specialty Products, a unit of Louisiana-Pacific Corporation (LP) headquartered in Nashville, Tenn. Other substituted materials may include a combination of cellulose, wood and a plastic, such as polyethylene. Therefore, although this invention is discussed with and is primarily beneficial for use with fiber board, the invention is also applicable with the aforementioned substitutes and other alternative materials such as vinyl and rubber.
[0036] The foam boards 12 incorporate a contour cut alignment configuration on the front side 20 , as shown in FIG. 3 . The back side 22 is flat to support it against the wall, as shown in FIG. 4 . The flat side 22 of the board, FIG. 4 , will likely incorporate a drainage plane system 24 to assist in directing moisture runoff, if moisture finds its way into the wall 12 . It should be noted that moisture in the form of vapor, will pass through the foam from the warm side to the cold side with changes in temperature. The drainage plane system is incorporated by reference as disclosed in Application Ser. No. 60/511,527 filed on Oct. 15, 2003.
[0037] To install the fiber cement siding, according to the present invention, the installer must first establish a chalk line 26 at the bottom of the wall 28 of the building to serve as a straight reference line to position the foam board 12 for the first course 15 of foam board 12 , following siding manufacturer's instructions.
[0038] The foam boards 12 are designed to be installed or mated tightly next to each other on the wall 28 , both horizontally and vertically. The first course foam boards 12 are to be laid along the chalk line 26 beginning at the bottom corner of an exterior wall 28 of the building (as shown FIG. 5 ) and tacked into position. When installed correctly, this grid formation provided will help insure the proper spacing and alignment of each piece of lap siding 10 . As shown in FIGS. 5 and 6 , the vertical edges 16 a, 18 a of each foam board 12 are fabricated with an interlocking tab 16 and slot 18 mechanism that insure proper height alignment. Ensuring that the tabs 16 are fully interlocked and seated in the slots 18 , provides proper alignment of the cement lap siding. As shown in FIGS. 7 , 7 a , 7 b , the horizontal edges 30 , 32 incorporate ship-lapped edges 30 , 32 that allow both top and bottom foam boards 12 to mate tightly together. The foam boards 12 are also designed to provide proper horizontal spacing and alignment up the wall 28 from one course to the next, as shown in phantom in FIGS. 7 and 7 a.
[0039] As the exterior wall 28 is covered with foam boards 12 , it may be necessary to cut and fit the foam boards 12 as they mate next to doorways. windows, gable corners, electrical outlets, water faucets, etc. This cutting and fitting can be accomplished using a circular saw, a razor knife or a hot knife. The opening (not shown) should be set back no more than ⅛ inches for foundation settling.
[0040] Once the first course 15 has been installed, the second course 15 ′ of foam boards 12 can be installed at any time. The entire first course 15 on any given wall should be covered before the second course 15 ′ is installed. It is important to insure that each foam board 12 is fully interlocked and seated on the interlocking tabs 16 to achieve correct alignment.
[0041] The first piece of fiber cement lap siding 10 is installed on the first course 15 of the foam board 12 and moved to a position approximately ⅛ inches set back from the corner and pushed up against the foam board registration or alignment rib 14 (see FIG. 8 ) to maintain proper positioning of the panel 10 . The foam board registration or alignment rib 14 is used to align and space each fiber cement panel 10 properly as the siding job progresses. Unlike installing the fiber cement lap siding in the prior art, there is no need to measure the panel's relative face height to insure proper alignment. All the system mechanics have been accounted for in the rib 14 location on the foam board 12 . The applicator simply places the panel 10 in position and pushes it tightly up against the foam board alignment rib 14 immediately prior to fastening. A second piece of fiber cement lap siding can be butted tightly to the first, pushed up against the registration or alignment rib and fastened securely with fasteners 17 with either a nail gun or hammer. Because the alignment ribs 14 are preformed and pre-measured to correspond to the appropriate overlap 30 between adjacent fiber cement siding panels 10 , no measurement is required. Further, because the alignment ribs 14 are level with respect to one another, an installer need not perform the meticulous leveling tasks associated with the prior art methods of installation.
[0042] With reference to FIGS. 7 , 7 a , 7 b , vertically aligned boards 20 include a ship lap 30 , 32 mating arrangement which provides for a continuous foam surface. Furthermore, the interlocking tabs 16 , 18 together with the ship lap 30 , 32 ensures that adjacent fiber boards 12 , whether they be vertically adjacent or horizontally adjacent, may be tightly and precisely mated together such that no further measurement or alignment is required to maintain appropriate spacing between adjacent boards 12 . It is understood that as boards 12 are mounted and attached to one another it may be necessary to trim such boards when windows, corners, electrical outlets, water faucets, etc. are encountered. These cuts can be made with a circular saw, razor knife, or hot knife.
[0043] Thereafter, a second course of fiber cement siding 10 ′ can be installed above the first course 10 by simply repeating the steps and without the need for leveling or measuring operation. When fully seated up against the foam board alignment rib 14 , the fiber cement panel 10 ′ will project down over the first course 10 to overlap 34 by a desired 1¼ inches, as built into the system as shown in FIG. 3 . The next course is fastened against wall 28 using fasteners 36 as previously described. The foam board 12 must be fully and properly placed under all of the fiber cement panels 10 . The installer should not attempt to fasten the fiber cement siding 10 in an area that it is not seated on and protected by a foam board 12 .
[0044] The board 12 , described above, will be fabricated from foam at a thickness of approximately 1¼ inch peak height. Depending on the siding profile, the board 12 should offer a system “R” value of 3.5 to 4.0. This addition is dramatic considering that the average home constructed in the 1960's has an “R” value of 8. An R-19 side wall is thought to be the optimum in thermal efficiency. The use of the foam board will provide a building that is cooler in the summer and warmer in the winter. The use of the foam board 12 of the present invention also increases thermal efficiency, decreases drafts and provides added comfort to a home.
[0045] In an alternate embodiment, a family of insulated fiber cement lap siding panels 100 has been developed, as shown in FIG. 9 , in the interest of solving several limitations associated with present fiber cement lap sidings. These composite panels 100 incorporate a foam backer 112 that has been bonded or laminated to a complementary fiber cement lap siding panel 110 . Foam backing 112 preferably includes an angled portion 130 and a complementary angled portion 132 to allow multiple courses of composite fiber cement siding panels 100 to be adjoined. Foam backer 112 is positioned against fiber cement siding 110 in such a manner as to leave an overlap region 134 which will provide for an overlap of siding panels on installation.
[0046] The fiber cement composite siding panels 100 of the second preferred embodiment may be formed by providing appropriately configured foam backing pieces 132 which may be adhesively attached to the fiber cement siding panel 110 .
[0047] The composite siding panels 100 according to the second preferred embodiment may be installed as follows with reference to FIGS. 10 b , 10 c and 13 . A first course 115 is aligned appropriately against sill plate 40 adjacent to the foundation 42 to be level and is fastened into place with fasteners 36 . Thereafter, adjacent courses 115 ′ may be merely rested upon the previous installed course and fastened into place. The complementary nature of angled portions 130 , 132 will create a substantially uniformed and sealed foam barrier behind composite siding panels 100 . Overlap 134 , which has been pre-measured in relation to the foam pieces allows multiple courses to be installed without the need for measuring or further alignment. This dramatic new siding of the present invention combines an insulation component with an automatic self-aligning, stack-on siding design. The foam backer 112 provides a system “R” value in the range of 3.5 to 4.0. The foam backer 112 will also be fabricated from expanded polystyrene (EPS), which has been treated with a chemical additive to deter termites and carpenter ants.
[0048] The new self-aligning, stack-on siding design of the present invention provides fast, reliable alignment, as compared to the time consuming, repeated face measuring and alignment required on each course with the present lap design.
[0049] The new foam backer 112 has significant flexural and compressive strength. The fiber cement siding manufacturer can reasonably take advantage of these attributes. The weight of the fiber cement siding 110 can be dramatically reduced by thinning, redesigning and shaping some of the profiles of the fiber cement 110 . FIG. 8 a shows the current dimensions of fiber cement boards, FIGS. 8 b , 8 c , and 8 c show thinner fiber cement board. Experience with other laminated siding products has shown that dramatic reductions in the base material can be made without adversely affecting the product's performance. The combination of weight reduction with the new stack-on design provides the installers with answers to their major objections. It is conceivable that the present thickness (D′) of fiber cement lap siding panels 110 of approximately 0.313 inches could be reduced to a thickness (D′) of 0.125 inches or less.
[0050] The fiber cement siding panel may include a lip 144 which, when mated to another course of similarly configured composite fiber cement siding can give the fiber cement siding 110 the appearance of being much thicker thus achieving an appearance of an increased shadow line. Further, it is understood although not required, that the fiber cement siding panel 110 may be of substantially reduced thickness, as stated supra, compared to the 5/16″ thickness provided by the prior art. Reducing the thickness of the fiber cement siding panel 110 yields a substantially lighter product, thereby making it far easier to install. A pair of installed fiber cement composite panels having a thickness (D′) of 0.125 or less is illustrated in FIGS. 8B-8D and 10 B and 10 C. Such installation is carried out in similar fashion as that described in the second preferred embodiment.
[0051] The present invention provides for an alternate arrangement of foam 112 supporting the novel configuration of fiber cement paneling. In particular, the foam may include an undercut recess 132 which is configured to accommodate an adjacent piece of foam siding. As shown in FIGS. 10 a , 10 b and 10 c , the new, thinner, insulated fiber cement lap siding panel 110 will allow the siding manufacturers to market panels with virtually any desirable shadow line, such as the popular new ¾ inch vinyl siding shadow line with the lip 144 formation. The lip 144 can have various lengths such as approximately 0.313 inch (E), 0.50 inch (F), and 0.75 (G) inch to illustrate a few variations as shown in FIGS. 8 b , 8 c , and 8 d , respectively. This new attribute would offer an extremely valuable, previously unattainable, selling feature that is simply beyond the reach with the current system.
[0052] No special tools or equipment are required to install the new insulated fiber cement lap siding 100 . However, a new starter adapter or strip 150 has been designed for use with this system, as shown in FIGS. 11 and 12 . It is preferable to drill nail holes 152 through the adapter 150 prior to installation. The installer must first establish a chalk line 26 at the bottom of the wall 28 to serve as a straight reference line to position the starter adapter 150 for the first course of siding and follow the siding manufacturer's instructions.
[0053] The siding job can be started at either corner 29 . The siding is placed on the starter adapter or strip 150 and seated fully and positioned, leaving a gap 154 of approximately ⅛ inches from the corner 29 of the building. Thereafter, the siding 100 is fastened per the siding manufacturer's installation recommendations using a nail gun or hammer to install the fasteners 36 . Thereafter, a second course of siding 115 ′ can be installed above the first course 115 by simply repeating the steps, as shown in FIG. 13 . Where practical, it is preferable to fully install each course 115 before working up the wall, to help insure the best possible overall alignment. Installation in difficult and tight areas under and around windows, in gable ends, etc. is the same as the manufacturer's instruction of the current fiber cement lap siding 10
[0054] The lamination methods and adhesive system will be the same as those outlined in U.S. Pat. Nos. 6,019,415 and 6,195,92B1.
[0055] The insulated fiber cement stack-on sliding panels 100 described above will have a composite thickness of approximately 1¼ inches. Depending on the siding profile, the composite siding 100 should offer a system “R” value of 3.5 to 4.0. This addition is dramatic when you consider that the average home constructed in the 1960's has an “R” value of 8. An “R-19” side wall is thought to be the optimum in energy efficiency. A building will be cooler in the summer and warmer in the winter with the use of the insulated fiber cement siding of the present invention.
[0056] While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the fiber cement siding board disclosed in the invention can be substituted with the aforementioned disclosed materials and is not to be 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, which scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures as is permitted under the law.
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Disclosed herein are embodiments of foam backing panels for use with lap siding and configured for mounting on a building. Also disclosed are lap siding assemblies and products of lap sidings. One such embodiment of the foam backing panel comprises a rear face configured to contact the building, a front face configured for attachment to the lap siding, alignment means for aligning the lap siding relative to the building, means for providing a shadow line, opposing vertical side edges, a top face extending between a top edge of the front face and rear face and a bottom face extending between a bottom edge of the front face and rear face.
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FIELD OF THE INVENTION
The present invention pertains to screw-type container/closure systems, any system where the closure rotates relative to the container while being mounted and demounted from the container.
SUMMARY
Container/closure systems wherein a closure is rotated relative to a container while being mounted and demounted from the container are well known. Examples of these include containers and closures with complementary screw threads, where the closure must complete at least one full rotation relative to the container to be fully seated on the container. Another example would be a container/closure system where the closure completes less than one full rotation relative to the container to be fully seated on the container. For example, a lug style closure may rotate only ¼ of a turn or only ½ of a turn when being seated and unseat from a container. In either type of rotating system, the closure and container are drawn together through their relative rotation. Typically, the rotation stops and the closure is fully mounted on the container when some portion of the closure bottoms out on some portion of the container. Preferably, at that point the closure makes an effective fluid tight seal on the container, while at the same time, there is no discernible gap between the closure and the container. This is not always easy to achieve, and it is often the case that when a closure is fully mounted on a container there is a gap between the closure and container. This gap disturbs the aesthetic appeal of the package. Furthermore, when a closure is screwed down onto a container, and reaches the point where it is fully mounted onto the container, this event is generally silent, and presents no interest for the user. It is a problem that cries out to be rectified.
OBJECTS OF THE INVENTION
A main object of the invention is to make dull rotating closures a thing of the past by providing a luxury experience to consumers.
Another main objective is to eliminate the gap between the closure and container in screw-threaded closure systems.
SUMMARY
The present challenges are met by a closure ( 11 ) comprising a screw-threaded inner cap ( 6 ) that mounts to a screw threaded container ( 1 ), and an overshell ( 9 ) that is enabled to rotate and translate relative to the inner cap, but only when the inner cap is fully mounted (i.e. bottomed out) on the container. As the overshell rotates relative to the inner cap, one or more magnets ( 10 ) located in the overshell pull the overshell toward one or more metallic elements ( 2 ) associated with the container. The overshell and container make direct contact, so there is no unsightly gap. Also, the contact produces a satisfying, reassuring metallic “click” sound, accompanied by a luxurious tactile sensation that, together, dispel the silent ennui normally associated with rotating closures.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is an exploded view of a screw-type closure system with magnetic feature according to the present invention.
FIG. 2 is a perspective view of the inner cap.
FIG. 3 is a cross sectional view of the inner cap of FIG. 2 .
FIG. 4 is a perspective view of the inner shell.
FIGS. 5A and 5B depict the same component. FIG. 5A is a perspective view of the overshell. In FIG. 5B , a portion of the overshell is cut away to show the interior of the overshell.
FIGS. 6A and 6B depict the same component. In FIGS. 6A and 6B , the overshell is transparent in order the show how the invention works. FIG. 6A shows the overshell before it drops down onto the container. FIG. 6 b shows the overshell after it has made contact with the container.
FIG. 7 shows a detail view, in cross section, of the neck area, in a preferred embodiment.
DETAILED DESCRIPTION
The present invention is described in relation to a conventional mascara container and a modified closure from which depends a wand type applicator. However, the principles of the invention can be extended to virtually any system that effects a seal by a relative rotation between a container and closure. Thus, FIG. 1 depicts a container ( 1 ) that has a threaded neck ( 1 b ) and a shoulder ( 1 c ). The container is suitable for holding a cosmetic product, a personal care product or essentially any product (P) in its internal reservoir ( 1 d ). The product may be accessed through an opening ( 1 e ) in the neck of the container.
Unlike conventional containers, one or more ferromagnetic elements are associated with the container ( 1 ), in the area below the threads ( 1 a ) of the threaded neck ( 1 b ). The one or more ferromagnetic elements are positioned so that they can interact with the magnets ( 10 ) of the overshell ( 9 ). Examples of suitable ferromagnetic materials include iron, nickel, cobalt and alloys that contain ferromagnetic metals, such as steel. In some preferred embodiments, it is required that the ferromagnetic elements and the magnets ( 10 ) are metallic, and able to able to contact each other with a force that is sufficient to make an audible clicking noise. For example, molding the shoulder of the container ( 1 ) with embedded ferromagnetic particles does not meet this requirement, because the contact between the magnets ( 10 ) and the shoulder would not create the kind of satisfying, reassuring metallic “click” sound. On the other hand, for example, in FIG. 1 , a metallic ring ( 2 ) (such as steel) is placed over the neck ( 1 b ) of the container, and rests on the shoulder ( 1 c ) of the container. In this embodiment, contact between the metallic magnets ( 10 ) and the steel ring ( 2 ) does create a satisfying, reassuring metallic “click” sound, with a luxury feel. The steel ring may be secured on the neck by any suitable means, such as adhesive. In those types of closure-container systems that do not have a shoulder, the one or more metallic elements (i.e. the steel ring 2 ) must be fixed in the area below the threads ( 1 a ) of the threaded neck ( 1 b ) by some other means.
A wiper ( 3 ) is located, in the usual manner, in the opening ( 1 e ) of the neck ( 1 b ) of the container ( 1 ), except for the flange ( 3 a ) of the wiper, which rests on the landing area ( 1 f ) of the neck. In those types of closure-container systems that have no wiper, the principles of the invention still apply. In the applicator system of FIG. 1 , an applicator head ( 4 ), such as a mascara brush, is attached to a rod ( 5 ) which depends from an inner cap ( 6 ), in the usual manner well known in the art.
A preferred embodiment of a closure ( 11 ) according to the present invention comprises elements 6 - 10 , as now described. Referring to FIGS. 2 and 3 , a threaded inner cap ( 6 ) comprises screw threads ( 6 a ) on its interior which are designed to work with the threads ( 1 a ) of the container ( 1 ). The threads of the container and inner cap are such that the landing area ( 6 f ) of the inner cap bottoms out on the landing area ( 1 f ) of the container before the bottom surface ( 6 c ) of the inner cap bottoms out on the steel ring ( 2 ) and/or shoulder ( 1 c ) of the container. Thus, when the inner cap is fully seated on the container, there is a gap between the bottom of the inner cap ( 6 ) and the shoulder ( 1 c ) of the container (see FIG. 6A ). The inner cap also comprises an annular flange ( 6 b ) that rises from the top surface ( 6 g ) of the inner cap ( 6 ). On the outer surface ( 6 h ) of the inner cap are one or more raised portions ( 6 d ) that extend between the top ( 6 g ) and bottom ( 6 c ) surfaces. Rising from the surface of each raised portion is a snap fitment ( 6 e ) which comprises a vertical section ( 6 v ) and an inclined section ( 6 i ). Preferably, the inner cap has at least two raised portions ( 6 d ), more preferably at least three raised portions. Each raised portion has a height equal to the height of the inner cap ( 6 ), and a specified width. The raised portions and snap fitments are designed to cooperate with cutouts ( 9 d ) on the interior surface ( 9 a ) of the overshell ( 9 ), as will be described below.
A spring ( 7 ) sits on top of the inner cap ( 6 ). In FIG. 6 , the spring is shown as surrounding the annular flange ( 6 b ) of the inner cap. In this way, the annular flange of the inner cap stabilizes the spring. Alternatively, the spring could be sized to fit inside the annular flange of the inner cap. The top end ( 7 a ) of the spring pushes against the inner shell ( 8 ). Thus, the spring tends to urge the inner cap and the inner shell apart.
The inner shell ( 8 ) is a cylindrical body that fills the upper space of the overshell ( 9 ). The inner shell is fixed within the overshell and does not move relative to the overshell. This arrangement may be achieved by a friction fit between the overshell and inner shell and/or by adhesive, for example. An annular flange ( 8 b ) depends from the bottom surface of the inner shell ( 8 ). In FIG. 6 , the spring ( 7 ) is shown as surrounding the annular flange of the inner shell. In this way, the annular flange of the inner shell stabilizes the spring. Alternatively, the spring could be sized to fit inside the annular flange of the inner shell. The bottom end of the spring ( 7 b ) pushes against the inner cap ( 6 ). Thus, the spring ( 7 ) tends to urge the inner shell ( 8 ) and the overshell ( 9 ) away from the inner cap ( 6 ).
Referring to FIG. 5 , the overshell ( 9 ) is the part of the closure that a user gasps to open and close the container ( 1 ). The overshell has an interior surface ( 9 a ), and a bottom or opened end ( 9 c ), through which the overshell houses the inner cap ( 6 ), the spring ( 7 ), the inner shell ( 8 ) and the metallic magnets ( 10 ). The inner shell and magnets are firmly connected to the interior surface of the overshell, so that they cannot move relative to the overshell. However, the overshell is able to translate and rotate with respect to the inner cap. For example, the overshell ( 9 ) is able to slide up or down so that the inner cap is closer to or further away from the opened end ( 9 c ) of the overshell. One or more channels ( 9 b ) are cut into the interior surface of the overshell. The channels open up onto the opened end ( 9 c ) of the overshell. Each channel is designed to receive a metallic magnet ( 10 ). Preferably, there are at least two such channels, more preferably at least three. The metallic magnets may be retained in the channels by a friction fit or adhesive. The bottom of each magnet may extend slightly below the opened end ( 9 c ) of the overshell, so that they can contact the one or more ferromagnetic elements (i.e. metal ring 2 ) in the area below the threads ( 1 a ) of the container ( 1 ). As the separation between the magnets and metal ring is decreases (i.e. while the closure is being screwed down on the container), and before the landing area ( 6 f ) of the inner cap bottoms out on the landing area ( 1 f ) of the container, the combined force of attraction of all of the magnets for the metal ring must be able to overcome the extension force of the spring ( 7 ). The metallic magnets themselves may be simple bar magnets of cylindrical or rectangular cross section. For maximum effect, each magnet should be oriented so that one pole of the magnet is close to the metal ring, and the other pole is far from the metal ring. One preferred magnet is cylindrical neodymium-iron-boron (NdFeB) magnet, having a 1 mm diameter, 7 mm height, and a magnetization grade of N45. Magnets having a lesser magnetization grade, such as at least N20, at least N25 or at least N30 may also be useful.
Also located on the interior surface ( 9 a ) of the overshell ( 9 ) are one or more cutouts ( 9 d ). The cutouts are designed to cooperate with the one or more raised portions ( 6 d ) located on the outer surface ( 6 h ) of the inner cap ( 6 ). There is one cutout ( 9 d ) for each raised portion ( 6 d ). Each cutout comprises a taller section ( 9 t ), shorter section ( 9 s ), and a reduced section ( 9 r ) that opens onto the opened end ( 9 c ) of the overshell. At the top end of the reduced section there is a ledge ( 9 j ) that sometimes abuts the snap fitment ( 6 e ) of the inner cap. The height of the shorter section ( 9 s ) is at least as tall, and approximately equal to, the height of the raised portion ( 6 d ) of the inner cap ( 6 ). In order for the overshell to be slipped onto the inner cap, the cutouts ( 9 d ) must be aligned with and slide over the raised portions ( 6 d ). As the overshell slides over the inner cap, the reduced section ( 9 r ) of the overshell allows the snap fitment ( 6 e ) to enter into the cutout ( 9 d ). The inner cap flexes inward until the vertical section ( 6 v ) of the snap fitment passes over the ledge ( 9 j ). At this point, each raised portion of the inner cap is confined within a cutout of the overshell, the inner cap is retained in the overshell ( 9 ), and, ordinarily, cannot back out of the overshell. Although the raised portions of the inner cap are confined within the cutouts of the overshell, some relative movement between the inner cap and the overshell is still possible, as we now describe.
Function of the Screw-Type Closure Systems with Magnetic Feature
Referring to FIG. 6A , the raised portion ( 6 d ) of the inner cap ( 6 ) is situated in the shorter section ( 9 s ) of the overshell ( 9 ). At this point, the spring ( 7 ) tends to bias the inner shell ( 8 ) and the overshell upward relative to the inner cap, so that the inner cap is urged closer to the opened end ( 9 c ) of the overshell, and so that the ledge ( 9 j ) of each cutout ( 9 d ) pushes against a snap fitment ( 6 e ). Before the closure is fully seated on the container ( 1 ), if the overshell is rotated clockwise to close the container, then the inner cap ( 6 ) may also rotate clockwise due to the net force of the ledges ( 9 j ) on the snap fitments ( 6 e ). As the magnets ( 10 ) get closer to the metal ring ( 2 ), the magnetic force would be sufficient to overcome the spring bias, and the overshell would be pulled downward relative to the inner cap, if not for the top of the raised portion ( 6 d ) abutting the top of the shorter section ( 9 s ) of the cutout ( 9 d ). However, once the landing area ( 6 f ) of the inner cap bottoms out on the flange ( 3 a ) of the wiper ( 3 ), the overshell is able to rotate with respect to the inner cap ( 6 ) (as much as 10° to 45°, for example), with the result that the taller sections ( 9 t ) of the cutouts ( 9 d ) of the overshell move over the raised portions ( 6 d ) of the inner cap. Once this happens, the attraction of the magnets ( 10 ) for the metal ring ( 2 ) overcomes the spring bias, and pulls the overshell downward (relative to the inner cap and container 1 ) toward the ferromagnetic elements (i.e. metal ring 2 ), until the magnets contact the metal ring. Ideally, at this point, the opened end ( 9 c ) of the overshell is resting on the metallic ring, so there is no discernible gap. This is depicted in FIG. 6B . The force of contact between the magnets and the metal ring is sufficient to make an audible clicking noise, and create a satisfying, reassuring metallic “click” sound, with a luxury feel. The downward travel of the overshell is effected by magnetism, not by the user, and this provides the user with magical or luxurious sensation. Because the overshell ( 9 ) is able to slide downward independently of the inner cap, the present closure system ensures that there will be no gap between the container and closure when the package is in its closed configuration.
At this point, the raised portions ( 6 d ) of the inner cap ( 6 ) are trapped in the taller sections ( 9 t ) of the cutouts ( 9 d ) of the overshell ( 9 ). If we rotate the overshell counter-clockwise, to unscrew the closure from the container ( 1 ), the overshell and inner cap move as one due to the shorter side walls ( 9 w ) of the taller sections ( 9 t ) abutting the raised portions ( 6 d ) of the inner cap. As the inner cap rides on the threads ( 1 a ) of the container, the inner cap and overshell begin to rise, separating the magnets ( 10 ) and the metal ring ( 2 ). Therefore, to effect this counter-clockwise rotation, a user has to supply the force needed to overcome the magnetic force of attraction between the magnets ( 10 ) and the metal ring ( 2 ). When the magnetic force is weak enough due to this separation, the spring ( 7 ) pushes the overshell ( 9 ) up relative to the inner cap ( 6 ). At this point, the overshell can move independently of the inner cap. As the counter-clockwise rotation of the overshell ( 9 ) continues, the inner cap is now at rest, and the shorter cutouts ( 9 s ) of the overshell move over the raised portions ( 6 d ) of the inner cap. Soon enough, the side walls of the shorter sections ( 9 s ) push against the raised portions ( 9 d ) of the inner cap, so that the inner cap resumes counter-clockwise rotation with the overshell, until the inner cap is unscrewed from the container.
The design of the present invention is such that the overshell ( 9 ) experiences a net force from the magnets ( 10 ) and the spring ( 7 ). The net force of the magnets and spring is made to change direction (up or down relative to the inner cap 6 ) by screwing or unscrewing the inner cap on the container ( 1 ). When screwing the inner cap onto the container, the magnets get close enough to the ferromagnetic elements ( 2 ) so that the force of attraction overcomes the spring bias. At that point, the net force is downward, and the overshell can translate downward if the taller sections ( 9 t ) are positioned over the raised portions ( 6 d ). Likewise, when unscrewing the inner cap from the container, the magnets move away from ferromagnetic elements ( 2 ) until the spring bias can overcome the magnetic force of attraction, at which point the net force on the overshell is upward, and the overshell can translate upward if the taller sections ( 9 t ) are over the raised portions ( 6 d ). Thus, the overshell is enabled to translate up and down relative to the inner cap only when the raised portions ( 6 d ) of the inner cap ( 6 ) are located in the taller sections ( 9 t ) of the overshell ( 9 ), and not when the raised portions ( 6 d ) are located in the shorter sections ( 9 s ) of the overshell ( 9 ).
In one preferred embodiment of the invention (see FIG. 7 ), the container ( 1 ) is provided with a metal collar ( 1 g ) that fits around the neck ( 1 b ) and rests on top of the metal ring ( 2 ). In this way, the metal ring 2 is hidden and the container has a trimmed, finished appearance. Optionally, the container may have a lower shoulder ( 1 h ). In this case, the collar rests on the lower shoulder, and perhaps the metal ring, and may fit tightly to the shoulder ( 1 c ) to hold itself in place.
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A closure-container system comprising a screw-threaded inner cap that mounts to a screw threaded container, and an overshell that is enabled to rotate and translate relative to the inner cap. As the overshell rotates relative to the inner cap, one or more metallic magnets located in the overshell pull the cap toward one or more metallic elements associated with the container. The overshell and container make direct contact, so there is no unsightly gap. Also, the contact produces a satisfying, reassuring metallic “click” sound, accompanied by a luxurious tactile sensation that, together, dispel the silent ennui normally associated with rotating closures.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Patent Application No. 60/728895 filed on Oct. 21 st , 2005, and which is hereby incorporated by reference in its entirety.
TECHNICAL FIELD
[0002] The present invention relates to electrically variable transmissions having two planetary gear sets and three motor/generators that are controllable to provide continuously variable speed ratio ranges.
BACKGROUND OF THE INVENTION
[0003] Electric hybrid vehicles offer the potential for significant fuel economy improvements over their conventional counterparts; however, their overall efficiency is limited by parasitic losses. In single-mode electric variable transmissions (EVT) these losses are mostly attributed to electric machines rotating at high speeds. Two-mode EVTs offer the advantage of reduced motor-generator speeds, but often suffer losses attributed to high-pressure hydraulic pump and clutches needed for mode switching. Significant vehicle fuel economy gains can be realized if the losses associated with high-pressure hydraulic pump, clutches and high motor-generator speeds are substantially eliminated.
SUMMARY OF THE INVENTION
[0004] This invention describes continuously-variable mechatronic hybrid transmissions that offer the advantages of multi-mode EVTs without the need for clutches and the associated high pressure hydraulic pump.
[0005] The electrically variable transmission family of the present invention provides low-content, low-cost electrically variable transmission mechanisms including first and second differential gear sets, a battery (or similar energy storage device) and three electric machines serving interchangeably as motors or generators. Preferably, the differential gear sets are planetary gear sets, but other gear arrangements may be implemented, such as bevel gears or differential gearing to an offset axis.
[0006] In this description, the first and second planetary gear sets may be counted first to second in any order (i.e., left to right, right to left).
[0007] Each of the two planetary gear sets has three members. The first, second or third member of each planetary gear set can be any one of a sun gear, ring gear or carrier, or alternatively a pinion.
[0008] Each carrier can be either a single-pinion carrier (simple) or a double-pinion carrier (compound).
[0009] The input shaft is continuously connected with a member of the planetary gear sets. The output shaft is continuously connected with another member of the planetary gear sets.
[0010] An interconnecting member continuously connects the first member of the first planetary gear set with the first member of the second planetary gear set.
[0011] A first motor/generator is connected to a member of the first planetary gear set.
[0012] A second motor/generator is connected to a member of the second planetary gear set.
[0013] A third motor/generator is connected to a member of the first or second planetary gear set.
[0014] In essence, the planetary gear arrangement has five nodes which are connected with the input shaft, output shaft and three motor/generators. The electric motor/generators are connected with drive units, control system and energy storage devices, such as a battery.
[0015] The three motor/generators are operated in a coordinated fashion to yield continuously variable forward and reverse speed ratios between the input shaft and the output shaft, while minimizing the rotational speeds of the motor-generators and optimizing the overall efficiency of the system. The tooth ratios of the planetary gear sets can be suitably selected to match specific applications.
[0016] The above features and advantages and other features and advantages of the present invention are readily apparent from the following detailed description of the best modes for carrying out the invention when taken in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a schematic representation of a powertrain including an electrically variable transmission incorporating a family member of the present invention;
[0018] FIG. 2 is a schematic representation of a powertrain including an electrically variable transmission incorporating a family member of the present invention;
[0019] FIG. 3 is a schematic representation of a powertrain including an electrically variable transmission incorporating a family member of the present invention;
[0020] FIG. 4 is a schematic representation of a powertrain including an electrically variable transmission incorporating a family member of the present invention;
[0021] FIG. 5 is a schematic representation of a powertrain including an electrically variable transmission incorporating a family member of the present invention;
[0022] FIG. 6 is a schematic representation of a powertrain including an electrically variable transmission incorporating a family member of the present invention;
[0023] FIG. 7 is a schematic representation of a powertrain including an electrically variable transmission incorporating a family member of the present invention;
[0024] FIG. 8 is a schematic representation of a powertrain including an electrically variable transmission incorporating a family member of the present invention;
[0025] FIG. 9 is a schematic representation of a powertrain including an electrically variable transmission incorporating a family member of the present invention;
[0026] FIG. 10 is a schematic representation of a powertrain including an electrically variable transmission incorporating a family member of the present invention;
[0027] FIG. 11 is a schematic representation of a powertrain including an electrically variable transmission incorporating a family member of the present invention;
[0028] FIG. 12 is a schematic representation of a powertrain including an electrically variable transmission incorporating a family member of the present invention; and
[0029] FIG. 13 is a schematic representation of a powertrain including an electrically variable transmission incorporating a family member of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0030] With reference to FIG. 1 , a powertrain 10 is shown, including an engine 12 connected to one preferred embodiment of the improved electrically variable transmission (EVT), designated generally by the numeral 14 . Transmission 14 is designed to receive at least a portion of its driving power from the engine 12 . As shown, the engine 12 has an output shaft that serves as the input member 17 of the transmission 14 . A transient torque damper (not shown) may also be implemented between the engine 12 and the input member 17 of the transmission.
[0031] In the embodiment depicted the engine 12 may be a fossil fuel engine, such as a gasoline or diesel engine which is readily adapted to provide its available power output typically delivered at a selectable number of revolutions per minute (RPM).
[0032] Irrespective of the means by which the engine 12 is connected to the transmission input member 17 , the transmission input member 17 is operatively connected to a planetary gear set in the transmission 14 .
[0033] An output member 19 of the transmission 14 is connected to a final drive 16 .
[0034] The transmission 14 utilizes two differential gear sets, preferably in the nature of planetary gear sets 20 and 30 . The planetary gear set 20 employs an outer gear member 24 , typically designated as the ring gear. The ring gear member 24 circumscribes an inner gear member 22 , typically designated as the sun gear. A carrier member 26 rotatably supports a plurality of planet gears 27 such that each planet gear 27 simultaneously, and meshingly engages both the outer, ring gear member 24 and the inner, sun gear member 22 of the first planetary gear set 20 .
[0035] The planetary gear set 30 also employs an outer gear member 34 , typically designated as the ring gear. The ring gear member 34 circumscribes an inner gear member 32 , typically designated as the sun gear. A carrier member 36 rotatably supports a plurality of planet gears 37 such that each planet gear 37 simultaneously, and meshingly engages both the outer, ring gear member 34 and the inner, sun gear member 32 of the planetary gear set 30 .
[0036] The input shaft 17 is continuously connected to the carrier member 36 of the planetary gear set 30 . The output shaft 19 is continuously connected to the ring gear member 34 of the planetary gear set 30 .
[0037] An interconnecting member 70 continuously connects the ring gear member 24 of the planetary gear set 20 with the ring gear member 34 of the planetary gear set 30 .
[0038] The first preferred embodiment 10 also incorporates first, second and third motor/generators 80 , 82 and 84 , respectively. The stator of the first motor/generator 80 is secured to the transmission housing 60 . The rotor of the first motor/generator 80 is secured to the sun gear member 32 of the planetary gear set 30 .
[0039] The stator of the second motor/generator 82 is secured to the transmission housing 60 . The rotor of the second motor/generator 82 is secured to the sun gear member 22 of the planetary gear set 20 .
[0040] The stator of the third motor/generator 84 is secured to the transmission housing 60 . The rotor of the third motor/generator 84 is secured to the carrier member 26 of the planetary gear set 20 .
[0041] Returning now to the description of the power sources, it should be apparent from the foregoing description, and with particular reference to FIG. 1 , that the transmission 14 selectively receives power from the engine 12 . The hybrid transmission also receives power from an electric power source 86 , which is operably connected to a controller 88 . The electric power source 86 may be one or more batteries. Other electric power sources, such as capacitors or fuel cells, that have the ability to provide, or store, and dispense electric power may be used in place of or in combination with batteries without altering the concepts of the present invention. The speed ratio between the input shaft and output shaft is prescribed by the speeds of the three motor/generators and the ring gear/sun gear tooth ratios of the planetary gear sets. Those with ordinary skill in the transmission art will recognize that desired input/output speed ratios can be realized by suitable selection of the speeds of the three motor/generators.
Description of a Second Exemplary Embodiment
[0042] With reference to FIG. 2 , a powertrain 110 is shown, including an engine 12 connected to one preferred embodiment of the improved electrically variable transmission (EVT), designated generally by the numeral 114 . Transmission 114 is designed to receive at least a portion of its driving power from the engine 12 . As shown, the engine 12 has an output shaft that serves as the input member 17 of the transmission 114 . A transient torque damper (not shown) may also be implemented between the engine 12 and the input member 17 of the transmission.
[0043] In the embodiment depicted the engine 12 may be a fossil fuel engine, such as a gasoline or diesel engine which is readily adapted to provide its available power output typically delivered at a selectable number of revolutions per minute (RPM).
[0044] Irrespective of the means by which the engine 12 is connected to the transmission input member 17 , the transmission input member 17 is operatively connected to a planetary gear set in the transmission 114 .
[0045] An output member 19 of the transmission 114 is connected to a final drive 16 .
[0046] The transmission 114 utilizes two differential gear sets, preferably in the nature of planetary gear sets 120 and 130 . The planetary gear set 120 employs an outer gear member 124 , typically designated as the ring gear. The ring gear member 124 circumscribes an inner gear member 122 , typically designated as the sun gear. A carrier member 126 rotatably supports a plurality of planet gears 127 such that each planet gear 127 simultaneously, and meshingly engages both the outer, ring gear member 124 and the inner, sun gear member 122 of the first planetary gear set 120 .
[0047] The planetary gear set 130 also employs an outer gear member 134 , typically designated as the ring gear. The ring gear member 134 circumscribes an inner gear member 132 , typically designated as the sun gear. A carrier member 136 rotatably supports a plurality of planet gears 137 such that each planet gear 137 simultaneously, and meshingly engages both the outer, ring gear member 134 and the inner, sun gear member 132 of the planetary gear set 130 .
[0048] The input shaft 17 is continuously connected to the carrier member 136 of the planetary gear set 130 . The output shaft 19 is continuously connected to the ring gear member 134 of the planetary gear set 130 .
[0049] An interconnecting member 170 continuously connects the ring gear member 124 of the planetary gear set 120 with the carrier member 136 of the planetary gear set 130 .
[0050] The second preferred embodiment 110 also incorporates first, second and third motor/generators 180 , 182 and 184 , respectively. The stator of the first motor/generator 180 is secured to the transmission housing 160 . The rotor of the first motor/generator 180 is secured to the sun gear member 132 of the planetary gear set 130 .
[0051] The stator of the second motor/generator 182 is secured to the transmission housing 160 . The rotor of the second motor/generator 182 is secured to the sun gear member 122 of the planetary gear set 120 .
[0052] The stator of the third motor/generator 184 is secured to the transmission housing 160 . The rotor of the third motor/generator 184 is secured to the carrier member 126 of the planetary gear set 120 .
[0053] The hybrid transmission 114 receives power from the engine 12 , and also exchanges power with an electric power source 186 , which is operably connected to a controller 188 .
Description of a Third Exemplary Embodiment
[0054] With reference to FIG. 3 , a powertrain 210 is shown, including an engine 12 connected to one preferred embodiment of the improved electrically variable transmission (EVT), designated generally by the numeral 214 . Transmission 214 is designed to receive at least a portion of its driving power from the engine 12 . As shown, the engine 12 has an output shaft that serves as the input member 17 of the transmission 214 . A transient torque damper (not shown) may also be implemented between the engine 12 and the input member 17 of the transmission.
[0055] In the embodiment depicted the engine 12 may be a fossil fuel engine, such as a gasoline or diesel engine which is readily adapted to provide its available power output typically delivered at a selectable number of revolutions per minute (RPM).
[0056] Irrespective of the means by which the engine 12 is connected to the transmission input member 17 , the transmission input member 17 is operatively connected to a planetary gear set in the transmission 214 .
[0057] An output member 19 of the transmission 214 is connected to a final drive 16 .
[0058] The transmission 214 utilizes two differential gear sets, preferably in the nature of planetary gear sets 220 and 230 . The planetary gear set 220 employs an outer gear member 224 , typically designated as the ring gear. The ring gear member 224 circumscribes an inner gear member 222 , typically designated as the sun gear. A carrier member 226 rotatably supports a plurality of planet gears 227 such that each planet gear 227 simultaneously, and meshingly engages both the outer, ring gear member 224 and the inner, sun gear member 222 of the first planetary gear set 220 .
[0059] The planetary gear set 230 also employs an outer gear member 234 , typically designated as the ring gear. The ring gear member 234 circumscribes an inner gear member 232 , typically designated as the sun gear. A carrier member 236 rotatably supports a plurality of planet gears 237 such that each planet gear 237 simultaneously, and meshingly engages both the outer, ring gear member 234 and the inner, sun gear member 232 of the planetary gear set 230 .
[0060] The input shaft 17 is continuously connected to the carrier member 236 of the planetary gear set 230 . The output shaft 19 is continuously connected to the ring gear member 234 of the planetary gear set 230 .
[0061] An interconnecting member 270 continuously connects the carrier member 226 with the carrier member 236 .
[0062] The preferred embodiment 210 also incorporates first, second and third motor/generators 280 , 282 and 284 , respectively. The stator of the first motor/generator 280 is secured to the transmission housing 260 . The rotor of the first motor/generator 280 is secured to the sun gear member 232 of the planetary gear set 230 .
[0063] The stator of the second motor/generator 282 is secured to the transmission housing 260 . The rotor of the second motor/generator 282 is secured to the sun gear member 222 of the planetary gear set 220 .
[0064] The stator of the third motor/generator 284 is secured to the transmission housing 260 . The rotor of the third motor/generator 284 is secured to the ring gear member 224 of the planetary gear set 220 .
[0065] The hybrid transmission 214 receives power from the engine 12 , and also exchanges power with an electric power source 286 , which is operably connected to a controller 288 .
Description of a Fourth Exemplary Embodiment
[0066] With reference to FIG. 4 , a powertrain 310 is shown, including an engine 12 connected to one preferred embodiment of the improved electrically variable transmission (EVT), designated generally by the numeral 314 . Transmission 314 is designed to receive at least a portion of its driving power from the engine 12 . As shown, the engine 12 has an output shaft that serves as the input member 17 of the transmission 314 . A transient torque damper (not shown) may also be implemented between the engine 12 and the input member 17 of the transmission.
[0067] In the embodiment depicted the engine 12 may be a fossil fuel engine, such as a gasoline or diesel engine which is readily adapted to provide its available power output typically delivered at a selectable number of revolutions per minute (RPM).
[0068] Irrespective of the means by which the engine 12 is connected to the transmission input member 17 , the transmission input member 17 is operatively connected to a planetary gear set in the transmission 14 . An output member 19 of the transmission 314 is connected to a final drive 16 .
[0069] The transmission 314 utilizes two differential gear sets, preferably in the nature of planetary gear sets 320 and 330 . The planetary gear set 320 employs an outer gear member 324 , typically designated as the ring gear. The ring gear member 324 circumscribes an inner gear member 322 , typically designated as the sun gear. A carrier member 326 rotatably supports a plurality of planet gears 327 such that each planet gear 327 simultaneously, and meshingly engages both the outer, ring gear member 324 and the inner, sun gear member 322 of the first planetary gear set 320 .
[0070] The planetary gear set 330 also employs an outer gear member 334 , typically designated as the ring gear. The ring gear member 334 circumscribes an inner gear member 332 , typically designated as the sun gear. A carrier member 336 rotatably supports a plurality of planet gears 337 such that each planet gear 337 simultaneously, and meshingly engages both the outer, ring gear member 334 and the inner, sun gear member 332 of the planetary gear set 330 .
[0071] The input shaft 17 is continuously connected to the carrier member 326 of the planetary gear set 320 . The output shaft 19 is continuously connected to the carrier member 336 of the planetary gear set 330 .
[0072] An interconnecting member 370 continuously connects the ring gear member 324 with the sun gear member 332 .
[0073] The preferred embodiment 310 also incorporates first, second and third motor/generators 380 , 382 and 384 , respectively. The stator of the first motor/generator 380 is secured to the transmission housing 360 . The rotor of the first motor/generator 380 is secured to the sun gear member 322 .
[0074] The stator of the second motor/generator 382 is secured to the transmission housing 360 . The rotor of the second motor/generator 382 is secured to the ring gear member 324 .
[0075] The stator of the third motor/generator 384 is secured to the transmission housing 360 . The rotor of the third motor/generator 384 is secured to the ring gear member 334 .
[0076] The hybrid transmission 314 receives power from the engine 12 , and also exchanges power with an electric power source 386 , which is operably connected to a controller 388 .
Description of a Fifth Exemplary Embodiment
[0077] With reference to FIG. 5 , a powertrain 410 is shown, including an engine 12 connected to one preferred embodiment of the improved electrically variable transmission (EVT), designated generally by the numeral 414 . Transmission 414 is designed to receive at least a portion of its driving power from the engine 12 . As shown, the engine 12 has an output shaft that serves as the input member 17 of the transmission 414 . A transient torque damper (not shown) may also be implemented between the engine 12 and the input member 17 of the transmission.
[0078] In the embodiment depicted the engine 12 may be a fossil fuel engine, such as a gasoline or diesel engine which is readily adapted to provide its available power output typically delivered at a selectable number of revolutions per minute (RPM).
[0079] Irrespective of the means by which the engine 12 is connected to the transmission input member 17 , the transmission input member 17 is operatively connected to a planetary gear set in the transmission 414 . An output member 19 of the transmission 414 is connected to a final drive 16 .
[0080] The transmission 414 utilizes two differential gear sets, preferably in the nature of planetary gear sets 420 and 430 . The planetary gear set 420 employs an outer gear member 424 , typically designated as the ring gear. The ring gear member 424 circumscribes an inner gear member 422 , typically designated as the sun gear. A carrier member 426 rotatably supports a plurality of planet gears 427 such that each planet gear 427 simultaneously, and meshingly engages both the outer, ring gear member 424 and the inner, sun gear member 422 of the first planetary gear set 420 .
[0081] The planetary gear set 430 also employs an outer gear member 434 , typically designated as the ring gear. The ring gear member 434 circumscribes an inner gear member 432 , typically designated as the sun gear. A carrier member 436 rotatably supports a plurality of planet gears 437 such that each planet gear 437 simultaneously, and meshingly engages both the outer, ring gear member 434 and the inner, sun gear member 432 of the planetary gear set 430 .
[0082] The input shaft 17 is continuously connected to the ring gear member 434 . The output shaft 19 is continuously connected to the carrier member 436 .
[0083] An interconnecting member 470 continuously connects the carrier member 426 with the carrier member 436 .
[0084] The preferred embodiment 410 also incorporates first, second and third motor/generators 480 , 482 and 484 , respectively. The stator of the first motor/generator 480 is secured to the transmission housing 460 . The rotor of the first motor/generator 480 is secured to the sun gear member 432 .
[0085] The stator of the second motor/generator 482 is secured to the transmission housing 460 . The rotor of the second motor/generator 482 is secured to the sun gear member 422 .
[0086] The stator of the third motor/generator 484 is secured to the transmission housing 460 . The rotor of the third motor/generator 484 is secured to the ring gear member 424 .
[0087] The hybrid transmission 414 receives power from the engine 12 , and also exchanges power with an electric power source 486 , which is operably connected to a controller 488 .
Description of a Sixth Exemplary Embodiment
[0088] With reference to FIG. 6 , a powertrain 510 is shown, including an engine 12 connected to one preferred embodiment of the improved electrically variable transmission (EVT), designated generally by the numeral 514 . Transmission 514 is designed to receive at least a portion of its driving power from the engine 12 . As shown, the engine 12 has an output shaft that serves as the input member 17 of the transmission 514 . A transient torque damper (not shown) may also be implemented between the engine 12 and the input member 17 of the transmission.
[0089] In the embodiment depicted the engine 12 may be a fossil fuel engine, such as a gasoline or diesel engine which is readily adapted to provide its available power output typically delivered at a selectable number of revolutions per minute (RPM).
[0090] Irrespective of the means by which the engine 12 is connected to the transmission input member 17 , the transmission input member 17 is operatively connected to a planetary gear set in the transmission 514 . An output member 19 of the transmission 514 is connected to a final drive 16 .
[0091] The transmission 514 utilizes two differential gear sets, preferably in the nature of planetary gear sets 520 and 530 . The planetary gear set 520 employs an outer gear member 524 , typically designated as the ring gear. The ring gear member 524 circumscribes an inner gear member 522 , typically designated as the sun gear. A carrier member 526 rotatably supports a plurality of planet gears 527 such that each planet gear 527 simultaneously, and meshingly engages both the outer, ring gear member 524 and the inner, sun gear member 522 of the planetary gear set 520 .
[0092] The planetary gear set 530 also employs an outer gear member 534 , typically designated as the ring gear. The ring gear member 534 circumscribes an inner gear member 532 , typically designated as the sun gear. A carrier member 536 rotatably supports a plurality of planet gears 537 such that each planet gear 537 simultaneously, and meshingly engages both the outer, ring gear member 534 and the inner, sun gear member 532 of the planetary gear set 530 .
[0093] The input shaft 17 is continuously connected to the carrier member 536 . The output shaft 19 is continuously connected to the carrier member 526 .
[0094] An interconnecting member 570 continuously connects the carrier member 526 with the ring gear member 534 .
[0095] The preferred embodiment 510 also incorporates first, second and third motor/generators 580 , 582 and 584 , respectively. The stator of the first motor/generator 580 is secured to the transmission housing 560 . The rotor of the first motor/generator 580 is secured to the sun gear member 522 .
[0096] The stator of the second motor/generator 582 is secured to the transmission housing 560 . The rotor of the second motor/generator 582 is secured to the ring gear member 524 .
[0097] The stator of the third motor/generator 584 is secured to the transmission housing 560 . The rotor of the third motor/generator 584 is secured to the sun gear member 532 .
[0098] The hybrid transmission 514 receives power from the engine 12 , and also exchanges power with an electric power source 586 , which is operably connected to a controller 588 .
Description of a Seventh Exemplary Embodiment
[0099] With reference to FIG. 7 , a powertrain 610 is shown, including an engine 12 connected to one preferred embodiment of the improved electrically variable transmission (EVT), designated generally by the numeral 614 . Transmission 614 is designed to receive at least a portion of its driving power from the engine 12 . As shown, the engine 12 has an output shaft that serves as the input member 17 of the transmission 614 . A transient torque damper (not shown) may also be implemented between the engine 12 and the input member 17 of the transmission.
[0100] In the embodiment depicted the engine 12 may be a fossil fuel engine, such as a gasoline or diesel engine which is readily adapted to provide its available power output typically delivered at a selectable number of revolutions per minute (RPM).
[0101] Irrespective of the means by which the engine 12 is connected to the transmission input member 17 , the transmission input member 17 is operatively connected to a planetary gear set in the transmission 614 . An output member 19 of the transmission 614 is connected to a final drive 16 .
[0102] The transmission 614 utilizes two differential gear sets, preferably in the nature of planetary gear sets 620 and 630 . The planetary gear set 620 employs an outer gear member 624 , typically designated as the ring gear. The ring gear member 624 circumscribes an inner gear member 622 , typically designated as the sun gear. A carrier member 626 rotatably supports a plurality of planet gears 627 such that each planet gear 627 simultaneously, and meshingly engages both the outer, ring gear member 624 and the inner, sun gear member 622 of the first planetary gear set 620 .
[0103] The planetary gear set 630 also employs an outer gear member 634 , typically designated as the ring gear. The ring gear member 634 circumscribes an inner gear member 632 , typically designated as the sun gear. A carrier member 636 rotatably supports a plurality of planet gears 637 such that each planet gear 637 simultaneously, and meshingly engages both the outer, ring gear member 634 and the inner, sun gear member 632 of the planetary gear set 630 .
[0104] The input shaft 17 is continuously connected to the carrier member 626 . The output shaft 19 is continuously connected to the carrier member 636 .
[0105] An interconnecting member 670 continuously connects the sun gear member 622 with the carrier member 636 .
[0106] The preferred embodiment 610 also incorporates first, second and third motor/generators 680 , 682 and 684 , respectively. The stator of the first motor/generator 680 is secured to the transmission housing 660 . The rotor of the first motor/generator 680 is secured to the ring gear member 624 .
[0107] The stator of the second motor/generator 682 is secured to the transmission housing 660 . The rotor of the second motor/generator 682 is secured to the sun gear member 632 .
[0108] The stator of the third motor/generator 684 is secured to the transmission housing 660 . The rotor of the third motor/generator 684 is secured to the ring gear member 634 .
[0109] The hybrid transmission 614 receives power from the engine 12 , and also exchanges power with an electric power source 686 , which is operably connected to a controller 688 .
Description of an Eighth Exemplary Embodiment
[0110] With reference to FIG. 8 , a powertrain 710 is shown, including an engine 12 connected to one preferred embodiment of the improved electrically variable transmission (EVT), designated generally by the numeral 714 . Transmission 714 is designed to receive at least a portion of its driving power from the engine 12 . As shown, the engine 12 has an output shaft that serves as the input member 17 of the transmission 714 . A transient torque damper (not shown) may also be implemented between the engine 12 and the input member 17 of the transmission.
[0111] In the embodiment depicted the engine 12 may be a fossil fuel engine, such as a gasoline or diesel engine which is readily adapted to provide its available power output typically delivered at a selectable number of revolutions per minute (RPM).
[0112] Irrespective of the means by which the engine 12 is connected to the transmission input member 17 , the transmission input member 17 is operatively connected to a planetary gear set in the transmission 714 . An output member 19 of the transmission 714 is connected to a final drive 16 .
[0113] The transmission 714 utilizes two differential gear sets, preferably in the nature of planetary gear sets 720 and 730 . The planetary gear set 720 employs an outer gear member 724 , typically designated as the ring gear. The ring gear member 724 circumscribes an inner gear member 722 , typically designated as the sun gear. A carrier member 726 rotatably supports a plurality of planet gears 727 such that each planet gear 727 simultaneously, and meshingly engages both the outer, ring gear member 724 and the inner, sun gear member 722 of the planetary gear set 720 .
[0114] The planetary gear set 730 also employs an outer gear member 734 , typically designated as the ring gear. The ring gear member 734 circumscribes an inner gear member 732 , typically designated as the sun gear. A carrier member 736 rotatably supports a plurality of planet gears 737 such that each planet gear 737 simultaneously, and meshingly engages both the outer, ring gear member 734 and the inner, sun gear member 732 of the planetary gear set 730 .
[0115] The input shaft 17 is continuously connected to the carrier member 726 . The output shaft 19 is continuously connected to the carrier member 736 .
[0116] An interconnecting member 770 continuously connects the sun gear member 722 with the sun gear member 732 .
[0117] The preferred embodiment 710 also incorporates first, second and third motor/generators 780 , 782 and 784 , respectively. The stator of the first motor/generator 780 is secured to the transmission housing 760 . The rotor of the first motor/generator 780 is secured to the ring gear member 724 .
[0118] The stator of the second motor/generator 782 is secured to the transmission housing 760 . The rotor of the second motor/generator 782 is secured to the carrier member 736 , and therefore the output member 19 .
[0119] The stator of the third motor/generator 784 is secured to the transmission housing 760 . The rotor of the third motor/generator 784 is secured to the ring gear member 734 .
[0120] The hybrid transmission 714 receives power from the engine 12 , and also exchanges power with an electric power source 786 , which is operably connected to a controller 788 .
Description of a Ninth Exemplary Embodiment
[0121] With reference to FIG. 9 , a powertrain 810 is shown, including an engine 12 connected to one preferred embodiment of the improved electrically variable transmission (EVT), designated generally by the numeral 814 . Transmission 814 is designed to receive at least a portion of its driving power from the engine 12 . As shown, the engine 12 has an output shaft that serves as the input member 17 of the transmission 814 . A transient torque damper (not shown) may also be implemented between the engine 12 and the input member 17 of the transmission.
[0122] In the embodiment depicted the engine 12 may be a fossil fuel engine, such as a gasoline or diesel engine which is readily adapted to provide its available power output typically delivered at a selectable number of revolutions per minute (RPM).
[0123] Irrespective of the means by which the engine 12 is connected to the transmission input member 17 , the transmission input member 17 is operatively connected to a planetary gear set in the transmission 814 . An output member 19 of the transmission 814 is connected to a final drive 16 .
[0124] The transmission 814 utilizes two differential gear sets, preferably in the nature of planetary gear sets 820 and 830 . The planetary gear set 820 employs an outer gear member 824 , typically designated as the ring gear. The ring gear member 824 circumscribes an inner gear member 822 , typically designated as the sun gear. A carrier member 826 rotatably supports a plurality of planet gears 827 such that each planet gear 827 simultaneously, and meshingly engages both the outer, ring gear member 824 and the inner, sun gear member 822 of the planetary gear set 820 .
[0125] The planetary gear set 830 , also employs an outer gear member 834 , typically designated as the ring gear. The ring gear member 834 circumscribes an inner gear member 832 , typically designated as the sun gear. A carrier member 836 rotatably supports a plurality of planet gears 837 such that each planet gear 837 simultaneously, and meshingly engages both the outer, ring gear member 834 and the inner, sun gear member 832 of the planetary gear set 830 .
[0126] The input shaft 17 is continuously connected to the ring gear member 824 . The output shaft 19 is continuously connected to the ring gear member 834 .
[0127] An interconnecting member 870 continuously connects the carrier member 826 with the carrier member 836 .
[0128] The preferred embodiment 810 also incorporates first, second and third motor/generators 880 , 882 and 884 , respectively. The stator of the first motor/generator 880 is secured to the transmission housing 860 . The rotor of the first motor/generator 880 is secured to the sun gear member 822 .
[0129] The stator of the second motor/generator 882 is secured to the transmission housing 860 . The rotor of the second motor/generator 882 is secured to the sun gear member 832 .
[0130] The stator of the third motor/generator 884 is secured to the transmission housing 860 . The rotor of the third motor/generator 884 is secured to the carrier member 836 .
[0131] The hybrid transmission 814 receives power from the engine 12 , and also exchanges power with an electric power source 886 , which is operably connected to a controller 888 .
Description of a Tenth Exemplary Embodiment
[0132] With reference to FIG. 10 , a powertrain 910 is shown, including an engine 12 connected to one preferred embodiment of the improved electrically variable transmission (EVT), designated generally by the numeral 914 . Transmission 914 is designed to receive at least a portion of its driving power from the engine 12 . As shown, the engine 12 has an output shaft that serves as the input member 17 of the transmission 914 . A transient torque damper (not shown) may also be implemented between the engine 12 and the input member 17 of the transmission.
[0133] In the embodiment depicted the engine 12 may be a fossil fuel engine, such as a gasoline or diesel engine which is readily adapted to provide its available power output typically delivered at a selectable number of revolutions per minute (RPM).
[0134] Irrespective of the means by which the engine 12 is connected to the transmission input member 17 , the transmission input member 17 is operatively connected to a planetary gear set in the transmission 914 . An output member 19 of the transmission 914 is connected to a final drive 16 .
[0135] The transmission 914 utilizes two differential gear sets, preferably in the nature of planetary gear sets 920 and 930 . The planetary gear set 920 employs an outer gear member 924 , typically designated as the ring gear. The ring gear member 924 circumscribes an inner gear member 922 , typically designated as the sun gear. A carrier member 926 rotatably supports a plurality of planet gears 927 , 928 . Each planet gear 927 meshingly engages sun gear member 922 and each planet gear 928 meshingly engages the ring gear member 924 and the respective planet gear 927 of the planetary gear set 920 .
[0136] The planetary gear set 930 employs an outer gear member 934 , typically designated as the ring gear. The ring gear member 934 circumscribes an inner gear member 932 , typically designated as the sun gear. A carrier member 936 rotatably supports a plurality of planet gears 937 such that each planet gear 937 simultaneously, and meshingly engages both the outer, ring gear member 934 and the inner, sun gear member 932 of the planetary gear set 930 .
[0137] The input shaft 17 is continuously connected to the ring gear member 924 . The output shaft 19 is continuously connected to the carrier member 936 .
[0138] An interconnecting member 970 continuously connects the carrier member 926 with the sun gear member 932 .
[0139] The preferred embodiment 910 also incorporates first, second and third motor/generators 980 , 982 and 984 , respectively. The stator of the first motor/generator 980 is secured to the transmission housing 960 . The rotor of the first motor/generator 980 is secured to the carrier member 926 .
[0140] The stator of the second motor/generator 982 is secured to the transmission housing 960 . The rotor of the second motor/generator 982 is secured to the sun gear member 922 .
[0141] The stator of the third motor/generator 984 is secured to the transmission housing 960 . The rotor of the third motor/generator 984 is secured to the ring gear member 934 .
[0142] The hybrid transmission 914 receives power from the engine 12 , and also exchanges power with an electric power source 986 , which is operably connected to a controller 988 .
Description of an Eleventh Exemplary Embodiment
[0143] With reference to FIG. 11 , a powertrain 1010 is shown, including an engine 12 connected to one preferred embodiment of the improved electrically variable transmission (EVT), designated generally by the numeral 1014 . Transmission 1014 is designed to receive at least a portion of its driving power from the engine 12 . As shown, the engine 12 has an output shaft that serves as the input member 17 of the transmission 1014 . A transient torque damper (not shown) may also be implemented between the engine 12 and the input member 17 of the transmission.
[0144] In the embodiment depicted the engine 12 may be a fossil fuel engine, such as a gasoline or diesel engine which is readily adapted to provide its available power output typically delivered at a selectable number of revolutions per minute (RPM).
[0145] Irrespective of the means by which the engine 12 is connected to the transmission input member 17 , the transmission input member 17 is operatively connected to a planetary gear set in the transmission 1014 . An output member 19 of the transmission 1014 is connected to a final drive 16 .
[0146] The transmission 1014 utilizes two differential gear sets, preferably in the nature of planetary gear sets 1020 and 1030 . The planetary gear set 1020 employs an outer gear member 1024 , typically designated as the ring gear. The ring gear member. 1024 circumscribes an inner gear member 1022 , typically designated as the sun gear. A carrier member 1026 rotatably supports a plurality of planet gears 1027 such that each planet gear 1027 simultaneously, and meshingly engages both the outer, ring gear member 1024 and the inner, sun gear member 1022 of the planetary gear set 1020 .
[0147] The planetary gear set 1030 employs an outer gear member 1034 , typically designated as the ring gear. The ring gear member 1034 circumscribes an inner gear member 1032 , typically designated as the sun gear. A carrier member 1036 rotatably supports a plurality of planet gears 1037 such that each planet gear 1037 simultaneously, and meshingly engages both the outer, ring gear member 1034 and the inner, sun gear member 1032 of the planetary gear set 1030 .
[0148] The input shaft 17 is continuously connected to the carrier member 1036 . The output shaft 19 is continuously connected to the ring gear member 1024 .
[0149] An interconnecting member 1070 continuously connects the carrier member 1026 with the ring gear member 1034 .
[0150] The preferred embodiment 1010 also incorporates first, second and third motor/generators 1080 , 1082 and 1084 , respectively. The stator of the first motor/generator 1080 is secured to the transmission housing 1060 . The rotor of the first motor/generator 1080 is secured to the sun gear member 1032 .
[0151] The stator of the second motor/generator 1082 is secured to the transmission housing 1060 . The rotor of the second motor/generator 1082 is secured to the ring gear member 1034 .
[0152] The stator of the third motor/generator 1084 is secured to the transmission housing 1060 . The rotor of the third motor/generator 1084 is secured to the sun gear member 1022 .
[0153] The hybrid transmission 1014 receives power from the engine 12 , and also exchanges power with an electric power source 1086 , which is operably connected to a controller 1088 .
Description of a Twelfth Exemplary Embodiment
[0154] With reference to FIG. 12 , a powertrain 1110 is shown, including an engine 12 connected to one preferred embodiment of the improved electrically variable transmission (EVT), designated generally by the numeral 1114 . Transmission 1114 is designed to receive at least a portion of its driving power from the engine 12 . As shown, the engine 12 has an output shaft that serves as the input member 17 of the transmission 1114 . A transient torque damper (not shown) may also be implemented between the engine 12 and the input member 17 of the transmission.
[0155] In the embodiment depicted the engine 12 may be a fossil fuel engine, such as a gasoline or diesel engine which is readily adapted to provide its available power output typically delivered at a selectable number of revolutions per minute (RPM).
[0156] Irrespective of the means by which the engine 12 is connected to the transmission input member 17 , the transmission input member 17 is operatively connected to a planetary gear set in the transmission 1114 . An output member 19 of the transmission 1114 is connected to a final drive 16 .
[0157] The transmission 1114 utilizes two differential gear sets, preferably in the nature of planetary gear sets 1120 and 1130 . The planetary gear set 1120 employs an outer gear member 1124 , typically designated as the ring gear. The ring gear member 1124 circumscribes an inner gear member 1122 , typically designated as the sun gear. A carrier member 1126 rotatably supports a plurality of planet gears 1127 such that each planet gear 1127 simultaneously, and meshingly engages both the outer, ring gear member 1124 and the inner, sun gear member 1122 of the planetary gear set 1120 .
[0158] The planetary gear set 1130 employs an outer gear member 1134 , typically designated as the ring gear. The ring gear member 1134 circumscribes an inner gear member 1132 , typically designated as the sun gear. A carrier member 1136 rotatably supports a plurality of planet gears 1137 such that each planet gear 1137 simultaneously, and meshingly engages both the outer, ring gear member 1134 and the inner, sun gear member 1132 of the planetary gear set 1130 .
[0159] The input shaft 17 is continuously connected to the sun gear member 1132 . The output shaft 19 is continuously connected to the ring gear member 1124 .
[0160] An interconnecting member 1170 continuously connects the carrier member 1126 with the ring gear member 1134 .
[0161] The preferred embodiment 1110 also incorporates first, second and third motor/generators 1180 , 1182 and 1184 , respectively. The stator of the first motor/generator 1180 is secured to the transmission housing 1160 . The rotor of the first motor/generator 1180 is secured to the carrier member 1136 .
[0162] The stator of the second motor/generator 1182 is secured to the transmission housing 1160 . The rotor of the second motor/generator 1182 is secured to the ring gear member 1134 .
[0163] The stator of the third motor/generator 1184 is secured to the transmission housing 1160 . The rotor of the third motor/generator 1184 is secured to the sun gear member 1122 .
[0164] The hybrid transmission 1114 receives power from the engine 12 , and also exchanges power with an electric power source 1186 , which is operably connected to a controller 1188 .
Description of a Thirteenth Exemplary Embodiment
[0165] With reference to FIG. 13 , a powertrain 1210 is shown, including an engine 12 connected to one preferred embodiment of the improved electrically variable transmission (EVT), designated generally by the numeral 1214 . Transmission 1214 is designed to receive at least a portion of its driving power from the engine 12 . As shown, the engine 12 has an output shaft that serves as the input member 17 of the transmission 1214 . A transient torque damper (not shown) may also be implemented between the engine 12 and the input member 17 of the transmission.
[0166] In the embodiment depicted the engine 12 may be a fossil fuel engine, such as a gasoline or diesel engine which is readily adapted to provide its available power output typically delivered at a selectable number of revolutions per minute (RPM).
[0167] Irrespective of the means by which the engine 12 is connected to the transmission input member 17 , the transmission input member 17 is operatively connected to a planetary gear set in the transmission 1214 . An output member 19 of the transmission 1214 is connected to a final drive 16 .
[0168] The transmission 1214 utilizes two differential gear sets, preferably in the nature of planetary gear sets 1220 and 1230 . The planetary gear set 1220 employs an outer gear member 1224 , typically designated as the ring gear. The ring gear member 1224 circumscribes an inner gear member 1222 , typically designated as the sun gear. A carrier member 1226 rotatably supports a plurality of planet gears 1227 such that each planet gear 1227 simultaneously, and meshingly engages both the outer, ring gear member 1224 and the inner, sun gear member 1222 of the planetary gear set 1220 .
[0169] The planetary gear set 1230 employs an outer gear member 1234 , typically designated as the ring gear. The ring gear member 1234 circumscribes an inner gear member 1232 , typically designated as the sun gear. A carrier member 1236 rotatably supports a plurality of planet gears 1237 such that each planet gear 1237 simultaneously, and meshingly engages both the outer, ring gear member 1234 and the inner, sun gear member 1232 of the planetary gear set 1230 .
[0170] The input shaft 17 is continuously connected to the carrier member 1236 . The output shaft 19 is continuously connected to the ring gear member 1224 .
[0171] An interconnecting member 1270 continuously connects the sun gear member 1222 with the ring gear member 1234 .
[0172] The preferred embodiment 1210 also incorporates first, second and third motor/generators 1280 , 1282 and 1284 , respectively. The stator of the first motor/generator 1280 is secured to the transmission housing 1260 . The rotor of the first motor/generator 1280 is secured to the sun gear member 1232 via an offset drive 1290 , such as a belt or chain, which may change the speed ratio.
[0173] The stator of the second motor/generator 1282 is secured to the transmission housing 1260 . The rotor of the second motor/generator 1282 is secured to the ring gear member 1234 .
[0174] The stator of the third motor/generator 1284 is secured to the transmission housing 1260 . The rotor of the third motor/generator 1284 is secured to the carrier member 1226 via an offset gear 1292 .
[0175] The hybrid transmission 1214 receives power from the engine 12 , and also exchanges power with an electric power source 1286 , which is operably connected to a controller 1288 .
[0176] While the best modes for carrying out the invention have been described in detail, those familiar with the art to which this invention relates will recognize various alternative designs and embodiments for practicing the invention within the scope of the appended claims.
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The electrically variable transmission family of the present invention provides low-content, low-cost electrically variable transmission mechanisms including first and second differential gear sets, a battery and three electric machines serving interchangeably as motors or generators. The three motor/generators are operable in a coordinated fashion to yield an EVT with a continuously variable range of speeds (including reverse).
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This is a division of application Ser. No. 07/585,495 filed Sep. 20, 1990, now U.S. Pat. No. 5,094,047, which in turn is a division of application Ser. No. 07/481,870 filed Feb. 20, 1990, now U.S. Pat. No. 5,014,473, which in turn is a division of application Ser. No. 07/327,313 filed Mar. 22, 1989, now U.S. Pat. No. 4,930,269.
BACKGROUND OF THE INVENTION
The field of this invention is the apparatus for hoisting and positioning prefabricated tilt-up concrete slabs. More specifically, the invention relates to improvements in clutch assemblies of such apparatus.
Prefabricated concrete walls or panels are common components of building constructions. Such panels are generally cast in a horizontal position where they are allowed to set. The hoisting and positioning of the finished panel presents problems in that the panels are very heavy and difficult to handle without cracking or breaking. Preliminary attempts to solve this problem can be found in U.S. Pat. No. 3,883,170, to Fricker et al., disclosing the use of an anchor imbedded in a concrete slab as a point of attachment and lifting in combination with a hoisting shackle, and in U.S. Pat. Nos. 4,367,892 and 4,437,642, to Holt, disclosing the use of a t-shaped anchor also for use with a hoisting shackle.
SUMMARY OF THE INVENTION
The present invention provides many advantages over the previous hoisting systems described above. First, it employs an anchor in the form of a lifting clevis and which is supported by anchor bases. Such anchors have greater strength in that they are less prone to bend or shear during the lifting process and are also less expensive to manufacture since less costly materials and production processes may be employed. Such anchors are also advantageous in that they provide two points of attachment for anchor supports, as well as additional steel reinforcement in the panel, thereby permitting stress to be distributed more broadly in the panel.
The invention also provides a void former which is asymmetric in configuration for producing a uniquely shaped recess that allows access to the clevis of the anchor in but one way. The void former comprises a body and plug configured to ensure that the clevis is fully and completely exposed once the slab is set.
The clutch assembly is proportioned for complimentable and snug receipt within the recess produced by the void former, and is provided with hoisting means. The clutch assembly engages the anchor by means of a linear engaging pin. Once coupled, the clutch assembly is capable of little if any movement about the clevis. Such a configuration minimizes the chances that the anchor or panel will become damaged during hoisting. Furthermore, the clutch assembly of the present invention provides an easy, reliable and safe means for engaging the anchor when the slab is horizontal and for disengaging when the slab is vertically placed, particularly where the anchors become located high up on the slab after placement.
A principal object of this invention is to provide an improved anchor which has a better shockload resistance and is less likely to fail when stressed, which gives extra embedment strength and which is easier and less costly to fabricate.
Another object of this invention is to provide an improved void former for use with the improved anchor.
A further object of this invention is to provide an improved clutch which mates more securely with an anchor imbedded in a concrete slab, which is easier to engage with and places less stress on an anchor, and which provides a more reliable, less stressful range of motion relative to the concrete panel.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded view in perspective showing the anchor assembly and void former of the invention.
FIG. 2 is a view in perspective showing the clutch assembly of the invention.
FIG. 3 is a view in perspective showing the clutch assembly engaged with the anchor embedded in a concrete panel.
FIG. 4 is a cross-sectional elevational view showing the anchor assembly and void former in place within a concrete panel.
FIG. 5 is a top plan view of the void former in open condition.
FIG. 6 is a view in cross-section of the void former in closed condition, taken on the plane designated by line 6--6 in FIG. 5, coupled to the anchor.
FIG. 7 is a view in cross-section of the clutch, taken on the plane designated by line 7--7 in FIG. 2.
FIG. 8 is a view in cross-section of the clutch, taken on the plane designated by line 8--8 in FIG. 7.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to the drawings, a tilt-up concrete slab 1 which is generally cast at the job site in horizontal, ground supported form, not shown, is cast around an anchor assembly 10 and a void former 30.
The anchor assembly 10 comprises a wire anchor 12 and two anchor supports 14. The wire anchor 12 is formed from a quandrangularly configured wire segment (not shown) by bending the segment substantially in half to form two legs 16 joined at an apex or clevis 18. The legs 16 diverge from the clevis 18 at an angle of 34°-36°. Each leg 16 of the wire anchor 12 is further bent to form a distal tip 20. The distal tips 20 diverge out of a plane defined by the clevis 18 and legs 16 at an angle of 88°-92°. The material of the wire anchor is metallic, preferably steel.
The wire anchor 12 is supported and positioned within the concrete slab 1 by anchor supports 14. Each anchor support 14 comprises a platform 22 supported by foot elements 24. The upper surface of the platform is provided with an apertured box 26 complemental in shape to and capable of snug receipt over a distal tip 20 of the wire anchor 12. The anchor support 14 can be made of any durable material, such as polymer plastic.
The void former 30, shown in FIGS. 1, 4, 5 and 6, is comprised of a body 32, a plug 34 and a lid 36. The body 32 is asymmetrically configured and is defined exteriorly by a flat side wall 38, a partially flat, partially curved side wall 40, a flattened end wall 42, a curved end wall 44, and a transversely curved underside wall 46.
The body 32 is provided on its underside with a socket 48 for complimentable receipt of the clevis 18 of the wire anchor 12 and the plug 34. The socket 48 is defined by an interior sloping wall 50, interior side walls 52, an interior receiving wall 54, and interior coupling walls 56. The interior receiving wall 54 is provided with pegs or dowels 58 for mating with and holding the plug 34 in place.
The plug 34 is configured for snug receipt within the socket 48 in which the clevis 18 of the wire anchor 12 is already in place and is provided with peg sockets 60 for receipt of the pegs 58 of the interior receiving wall 54 of the socket 48. The plug 34 is dimensioned so that when the plug 34 is in place within the body 32 of the void former 30, the exterior surface of the plug 34 is flush with the exterior surface of the body 32.
The lid 36 comprises peripherally distributed, downwardly projected camming lugs 62 and a plurality of upwardly projecting locator rods 64. The camming lugs 62 are adapted to snap into and interengage with an equal number of lug sockets 66 which are peripherally distributed along the upper edge of the body 32.
Emplacement of the wire anchor 12 within the concrete slab 1 takes place as follows. The wire anchor 12 is connected to the anchor supports 14 by sliding each of the distal tips 20 of the wire anchor 12 into the apertured box 26 of the anchor support 14. The void former 30 is then assembled about the clevis 18 of the wire anchor 12. First, the body 32 of the void former 30 is placed over the clevis 18 such that the clevis 18 is snugly received with the socket 48. The plug 34 is then inserted beneath the body 32/wire anchor 12 combination and snapped securely in place by engaging the peg sockets 60 with pegs 58, thereby enclosing the clevis 12 of the wire anchor. The lid 36 is snapped into position on the top of the body 32 by lockingly engaging the camming lugs 62 with the lug sockets 66. The combination of anchor assembly 10 and void former 30 is then positioned as desired on the wall form. The slab is then poured and cured.
In FIG. 4, the protruding rods 64 show the location of the wire anchor 12 with the slab 1. The thin layer of cement above the void former is then chipped away and the lid 36 popped off. The body 32 of the void former 30 can then be pulled out by gripping and pulling on internal ribs 57 with pliers. Removal of the body 32 creates a recess 2 to the rear of the plug 34. The plug 34 is then gripped by pliers, pulled from under the wire anchor 12 into the recess 2 and then removed.
The clutch assembly 70 comprises a housing 72; a housing cover 74 which is attached to the housing 72 by screw 76; a linear engaging pin 78 slidably mounted within a passage 79 in the housing; and a lever 80 which is comprised of an arm member 82, a shaft member 84 and a handle member 86. The lever 80 is pivotally engaged with pin 78 by means of a stud 88 which is carried by the engaging pin 78 and extends through a slot 90 in the arm member of the lever 80.
The housing 72 of the clutch assembly 70 is configured for complimentable receipt with the recess 2 left by the void former 30 and further comprises an engagement socket 92 for receipt over the clevis 18 of the wire anchor 12. FIGS. 7 and 8 illustrate the engagement pin 78 in retracted relation relative to the engagement socket.
The clutch assembly 70 is also provided with hoisting means as shown in FIGS. 2, 3 and 8. The hoisting means comprises: a bail 100; an external collar 102 fastened to the bail 100 by dowel pins 104; an internal collar (not shown) on the housing 72 rotatably received in the external collar 102, and a bolt 106 and plate washer 108 which fasten the external collar to the housing 72 for rotation about the internal collar.
Coupling with and hoisting of the concrete slab by the clutch assembly 70 takes place as follows. The housing 72 of the clutch assembly 70 is guided into the recess left by the void former 30 and over the clevis 18 of the imbedded wire anchor 12 with the engaging pin 78 in the retracted position. Once the housing 72 is snugly in place, the clevis 18 is engaged by moving the lever 80 to slide the engaging pin 78 in place. Having securely coupled the clutch assembly 70 to the concrete slab 1, a hoisting cable or rope (not shown) can be attached to the bail 100 with lifting force then applied to position the concrete slab in a desired position. Since the housing 72 is complimentably nested within the recess left by the void former 30, shearing force on the wire anchor 12 is reduced as is the threat of damage to the slab 1 resulting from uncontrolled movement of the clutch assembly 70 in relation to the wire anchor 12. Once the slab 1 is in place, the lever 80 is returned to its original position, thereby sliding the engaging pin 78 into its retracted position and releasing the clutch assembly 70 from the wire anchor 12 and the slab 1.
From the above description, it is apparent that a novel and advantageous apparatus and method for tilting up concrete slabs or panels is described. Although the disclosure above is illustrative of certain exemplary embodiments of the present invention, one skilled in the art will understand that other embodiments are possible which fall within the spirit or the essential characteristics of the invention, the scope of which is set forth in the following claims.
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An improved insert anchor assembly which provides a lifting clevis is disclosed. A novel void former comprising a body and plug to completely surround the lifting clevis is also disclosed. An improved hoisting attachment capable of complimentable receipt within the recess created by the void former is further provided.
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FIELD OF THE INVENTION
[0001] This invention relates to treating or preventing certain diseases or conditions using therapeutically active compounds. Particularly, this invention relates to methods using prostaglandin EP 4 agonist components to treat or prevent certain diseases or conditions.
BACKGROUND OF THE INVENTION
Description of Related Art
[0002] Prostaglandins can be described as derivatives of prostanoic acid which have the following structural formula:
[0003] Various types of prostaglandins are known, depending on the structure and substituents carried on the alicyclic ring of the prostanoic acid skeleton.
[0004] Further classification is based on the number of unsaturated bonds in the side chain indicated by numerical subscripts after the generic type of prostaglandin [e.g. prostaglandin E 1 (PGE 1 ), prostaglandin E 2 (PGE 2 )], and on the configuration of the substituents on the alicyclic ring indicated by α or β [e.g. prostaglandin F 2α (PGF 2β )].
[0005] Certain 10,10-dimethyl prostaglandins are known. These are described in documents such as the following:
Donde, in United States Patent No. Patent Application Publication No. 20040157901; Pernet et al in U.S. Pat. No. 4,117,014; Pernet, Andre G. et al., Prostaglandin analogs modified at the 10 and 11 positions, Tetrahedron Letters, (41), 1979, pp. 3933-3936; Plantema, Otto G. et al., Synthesis of (.+−.)-10.10-dimethylprostaglandin E1 methyl ester and its 15-epimer, Journal of the Chemical Society, Perkin Transactions 1: Organic and Bio-organic Chemistry (1972-1999), (3), 1978, pp. 304-308; Plantema, O. G. et al., Synthesis of 10,10-dimethylprostaglandin E1, Tetrahedron Letters, (51), 1975, 4039; Hamon, A., et al., Synthesis of (+−)- and 15-EPI(+−)-10,10-Dimethylprostaglandin E1, Tetrahedron Letters, Elsevier Science Publishers, Amsterdam, NL, no. 3, January 1976, pp. 211-214; and Patent Abstracts of Japan, Vol. 0082, no. 18 (C-503), Jun. 10, 1988 & JP 63 002972 A (Nippon lyakuhin Kogyo KK), 7 Jan. 1988;
the disclosures of these documents are hereby expressly incorporated by reference.
[0013] United States Patent Application Publication 2004/0142969 A1, expressly incorporated by reference herein, discloses compounds according to the formula below
The application discloses the identity of the groups as follows:
m is from 1 to 4; n is from 0 to 4; A is alkyl, aryl, heteroaryl, arylalkyl, arylcycloalkyl, cycloalkylalkyl, or aryloxyalkyl; E is —CHOH— or —C(O)—; X is —(CH 2 ) 2 — or —CH═CH—; Y is —CH 2 —, arylene, heteroarylene, —CH═CH—, —O—, —S(O) p — where p is from 0 to 2, or —NR a — where R a is hydrogen or alkyl; Z is —CH 2 OH, —CHO, tetrazol-5-yl, or —COOR b where R b is hydrogen or alkyl; and R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 and R 10 each independently are hydrogen or alkyl.
[0015] U.S. Pat. No. 6,747,037, expressly incorporated by reference herein, discloses prostaglandin EP 4 agonists such as
[0016] U.S. Pat. No. 6,610,719, expressly incorporated by reference herein, discloses prostaglandin EP 4 selective agonists having the structure
The patent describes the identity of the groups as follows:
Q is COOR 3 , CONHR 4 or tetrazol-5-yl; A is a single or cis double bond; B is a single or trans double bond; U is
R 2 is α-thienyl, phenyl, phenoxy, monosubstituted phenyl or monosubstituted phenoxy, said substituents being selected from the group consisting of chloro, fluoro, phenyl, methoxy, trifluoromethyl and (C 1 -C 3 )alkyl; R 3 is hydrogen, (C 1 -C 5 )alkyl, phenyl or p-biphenyl; R 4 is COR 5 or SO 2 R 5 ; and R 5 is phenyl or (C 1 -C 5 )alkyl.
[0025] 10-Hydroxyprostaglandin analogues, that is natural prostaglandin EP 4 agonist compounds where the hydroxide is present on carbon 10 rather than carbon 11, are known in several patent documents including U.S. Pat. No. 4,171,375; U.S. Pat. No. 3,931,297; FR 2408567; DE 2752523, JP 53065854, DE 2701455, SE 7700257, DK 7700272, NL 7700272, JP 52087144, BE 850348, FR 2338244, FR 2162213, GB 1405301, and ES 409167; all of which are expressly incorporated by reference herein.
[0026] U.S. patent application Ser. No. 821,705, filed Apr. 9, 2004, expressly incorporated by reference herein, discloses compounds having the following structure
wherein
J is C═O or CHOH; A is —(CH 2 ) 6 —, or cis —CH 2 CH═CH—(CH 2 ) 3 —, wherein 1 or 2 carbons may be substituted with S or O; B is CO 2 H, or CO 2 R, CONR 2 , CONHCH 2 CH 2 OH, CON(CH 2 CH 2 OH) 2 , CH 2 OR, P(O)(OR) 2 , CONRSO 2 R, SONR 2 , or
each of R and R 2 is independently H or C 1-6 alkyl; D is —(CH 2 ) n —, —X(CH 2 ) n , or —(CH 2 ) n X—, wherein n is from 0 to 3 and X is S or O; and E is an aromatic or heteroaromatic moiety having from 0 to 4 substituents, said substituents each comprising from 1 to 6 non-hydrogen atoms as disclosed in the application.
[0033] Other compounds of interest are disclosed in U.S. Pat. No. 6,670,485; U.S. Pat. No. 6,410,591; U.S. Pat. No. 6,538,018; WO 2004/065365; WO 03/074483; WO 03/009872; WO 2004/019938; WO 03/103664; WO 2004/037786; WO 2004/037813; WO 03/103604; WO 03/077910; WO 02/42268; WO 03/008377 WO 03/053923; WO 2004/078103; and WO 2003/035064, all of which are expressly incorporated by reference herein.
[0034] Prostaglandin EP 4 selective agonists are believed to have several medical uses. For example, U.S. Pat. No. 6,552,067 B2, expressly incorporated by reference herein, teaches the use of prostaglandin EP 4 selective agonists for the treatment of “methods of treating conditions which present with low bone mass, particularly osteoporosis, frailty, an osteoporotic fracture, a bone defect, childhood idiopathic bone loss, alveolar bone loss, mandibular bone loss, bone fracture, osteotomy, bone loss associated with periodontitis, or prosthetic ingrowth in a mammal.”
[0035] U.S. Pat. No. 6,586,468 B1, expressly incorporated by reference herein, teaches that prostaglandin EP 4 selective agonists “are useful for the prophylaxis and/or treatment of immune diseases (autoimmune diseases (amyotrophic lateral sclerosis (ALS), multiple sclerosis, Sjoegren's syndrome, arthritis, rheumatoid arthritis, systemic lupus erythematosus, etc.), post-transplantation graft rejection, etc.), asthma, abnormal bone formation, neurocyte death, pulmopathy, hepatopathy, acute hepatitis, nephritis, renal insufficiency, hypertension, myocardial ischemia, systemic inflammatory syndrome, pain induced by ambustion, sepsis, hemophagocytosis syndrome, macrophage activation syndrome, Still's diseases, Kawasaki diseases, burns, systemic granuloma, ulcerative colititis, Crohn's diseases, hypercytokinemia at dialysis, multiple organ failure, shock, etc.”
[0036] Inflammatory bowel disease (IBD) is a group of diseases characterized by inflammation in the large or small intestines and is manifest in symptoms such as diarrhea, pain, and weight loss. Nonsteroidal anti-inflammatory drugs have been shown to be associated with the risk of developing IBD, and recently Kabashima and colleagues have disclosed that “EP 4 works to keep mucosal integrity, to suppress the innate immunity, and to downregulate the proliferation and activation of CD4+ T cells. These findings have not only elucidated the mechanisms of IBD by NSAIDs, but also indicated the therapeutic potential of EP 4 -selective agonists in prevention and treatment of IBD.” (Kabashima, et. al., The Journal of Clinical Investigation , April 2002, Vol. 9, 883-893).
[0037] Various other diseases or conditions of the mammalian body occur to the detriment of the individual affected. Among such diseases or conditions are esophageal ulcers, alcohol gastropathy, duodenal ulcers, non-steroidal anti-inflammatory drug-induced gastroenteropathy and intestinal ischemia. New methods for treating or preventing such diseases or conditions would be highly beneficial.
SUMMARY OF THE INVENTION
[0038] The present invention relates to methods of treating or preventing one or more diseases or conditions, for example, of the mammalian body. Treating or preventing such disease(s) or condition(s) provides one or more substantial advantages, for example, enhances or maintains the health status of the individual, for example, human or animal, afflicted with or prone to affliction with such disease(s) or condition(s). The present methods are relatively easy to practice.
[0039] In one broad aspect of the invention, the present methods comprise administering a therapeutically effective amount of a prostaglandin EP 4 agonist component to a mammal afflicted with or prone to affliction with one or more diseases or conditions selected from an esophageal ulcer, alcohol gastropathy, a duodenal ulcer, non-steroidal anti-inflammatory drug-induced gastroenteropathy and intestinal ischemia, thereby treating or preventing the one or more diseases or conditions.
[0040] In one embodiment, the prostaglandin EP 4 agonist component is administered to a human. The prostaglandin EP 4 agonist component may be administered, for example, directly administered, to the gastrointestinal tract of a mammal, for example, a human.
[0041] Any and all features described herein and combinations of such features are included within the scope of the present invention provided that the features of any such combination are not mutually inconsistent.
DETAILED DESCRIPTION
[0042] A prostaglandin EP 4 agonist is broadly defined as a compound which an ordinary person in the art reasonably believes agonizes a prostaglandin EP 4 receptor according to any one or more of numerous assays for determination of the EP 4 activity that are well known to those of ordinary skill in the art. While not intending to be limiting, one such assay is given hereinafter.
[0043] In one embodiment, the prostagiandin EP 4 agonist is selective for a prostaglandin EP 4 receptor relative to other prostaglandin receptor subtypes. In another embodiment, the prostaglandin EP 4 agonist is at least 10 times more active at the EP 4 receptor than at any other prostaglandin receptor subtype. In another embodiment, the prostaglandin EP 4 agonist is at least 100 times more active at the EP 4 receptor than at any other prostaglandin receptor subtype. In another embodiment, the prostaglandin EP 4 agonist is at least 1000 times more active at the EP 4 receptor than at any other prostaglandin receptor subtype. While not intending to be limiting, typical assays for the other receptor subtypes are also given hereinafter.
[0044] While not intending to limit the scope of the invention in any way, compounds according to the structures below are examples of prostaglandin EP 4 agonists or prostaglandin EP 4 agonist components:
pharmaceutically acceptable salts thereof; and prodrugs thereof, wherein a dashed line represents the presence of absence of a bond;
A is —(CH 2 ) 6 —, cis —CH 2 CH═CH—(CH 2 ) 3 —, or —CH 2 C≡C—(CH 2 ) 3 —, wherein 1 or 2 carbon atoms may be substituted with S or O; or A is —(CH 2 ) m —Ar—(CH 2 ) o — wherein Ar is interarylene or heterointerarylene, the sum of m and o is from 1 to 4, and wherein one CH 2 may be substituted with S or O; X is S or O; J is C═O, CHOH, or CH 2 CHOH; and E is C 1-12 alkyl, R 2 , or —Y—R 2 wherein Y is CH 2 , S, or O, and R 2 is aryl or heteroaryl.
[0049] In these structures, a dashed line represents the presence or absence of a bond. Thus, a structure such as the one below,
represents three different structures, depicted as follows.
[0050] In relation to the identity of A disclosed in the chemical structures presented herein, in the broadest sense, A is —(CH 2 ) 6 —, cis —CH 2 CH═CH—(CH 2 ) 3 —, or —CH 2 C≡C—(CH 2 ) 3 —, wherein 1 or 2 carbon atoms may be substituted with S or O; or A is —(CH 2 ) m —Ar—(CH 2 ) o — wherein Ar is interarylene or heterointerarylene, the sum of m and o is from 1 to 3, and wherein one CH 2 may be substituted with S or O.
[0051] While not intending to be limiting, A may be —(CH 2 ) 6 —, cis —CH 2 CH═CH—(CH 2 ) 3 —, or —CH 2 C≡C—(CH 2 ) 3 —.
[0052] Alternatively, A may be a group which is related to one of these three moieties in which any carbon is substituted with S and/or O. For example, while not intending to limit the scope of the invention in any way, A may be an S substituted moiety such as one of the following or the like.
Alternatively, while not intending to limit the scope of the invention in any way, A may be an O substituted moiety such as one of the following or the like.
[0053] Alternatively, while not intending to limit the scope of the invention in any way, A may have both an O and a S substituted into the chain, such as one of the following or the like.
[0054] Alternatively, while not intending to limit the scope of the invention in any way, in certain embodiments A is —(CH 2 ) m —Ar—(CH 2 ) o — wherein Ar is interarylene or heterointerarylene, the sum of m and o is from 1 to 4, and wherein one CH 2 may be substituted with S or O. In other words, while not intending to limit the scope of the invention in any way, in one embodiment A comprises from 1 to 4 CH 2 moieties and Ar, e.g. —CH 2 —Ar—, —(CH 2 ) 2 —Ar—, —CH 2 —ArCH 2 —, —CH 2 Ar(CH 2 ) 2 —, —(CH 2 ) 2 —Ar(CH 2 ) 2 —, and the like; or
A comprises O, from 0 to 3 CH 2 moieties, and Ar, e.g., —O—Ar—, Ar—CH 2 —O—, —O—Ar—(CH 2 ) 2 —, —O—CH 2 —Ar—, —O—CH 2 —Ar—(CH 2 ) 2 , and the like; or A comprises S, from 0 to 3 CH 2 moieties, and Ar, e.g., —S—Ar—, Ar—CH 2 —S—, —S—Ar—(CH 2 ) 2 —, —S—CH 2 —Ar—, —S—CH 2 —Ar—(CH 2 ) 2 , and the like.
[0057] Interarylene or heterointerarylene refers to an aryl ring or ring system or a heteroaryl ring or ring system which connects two other parts of a molecule, i.e. the two parts are bonded to the ring in two distinct ring positions. Interarylene or heterointerarylene may be substituted or unsubstituted. Thus, an unsubstituted interarylene has 4 potential positions where a substituent could be attached. In one embodiment, Ar is substituted or unsubstituted interphenylene, interthienylene, interfurylene, or interpyridinylene. In one embodiment Ar is interphenylene (Ph). In one embodiment A is —(CH 2 ) 2 -Ph-. While not intending to limit the scope of the invention in any way, substituents may have 4 or less heavy atoms, or in other words, non-hydrogen atoms. Any number of hydrogen atoms required for a particular substituent will also be included. Thus, the substituent may be hydrocarbyl having up to 4 carbon atoms, including alkyl up to C 4 , alkenyl, alkynyl, and the like; hydrocarbyloxy up to C 3 ; CF 3 ; halo, such as F, Cl, or Br; hydroxyl; NH 2 and alkylamine functional groups up to C 3 ; other N or S containing substituents; and the like.
[0058] In one embodiment A is —(CH 2 ) m —Ar—(CH 2 ) o — wherein Ar is interphenylene, the sum of m and o is from 1 to 3, and wherein one CH 2 may be substituted with S or O.
[0059] In another embodiment A is —CH 2 —Ar—OCH 2 —. In another embodiment A is —CH 2 —Ar—OCH 2 — and Ar is interphenylene. In another embodiment, Ar is attached at the 1 and 3 positions, such as when A has the structure shown below.
[0060] In another embodiment A is —(CH 2 ) 6 —, cis —CH 2 CH═CH—(CH 2 ) 3 —, or —CH 2 C≡C—(CH 2 ) 3 —, wherein 1 or 2 carbon atoms may be substituted with S or O; or A is —(CH 2 ) 2 -Ph- wherein one CH 2 may be substituted with S or O.
[0061] In another embodiment A is —(CH 2 ) 6 —, cis —CH 2 CH═CH—(CH 2 ) 3 —, or —CH 2 C≡C—(CH 2 ) 3 —, wherein 1 or 2 carbon atoms may be substituted with S or O; or A is —(CH 2 ) 2 -Ph-.
[0062] J is C═O, CHOH, or CH 2 CHOH. Thus, while not intending to limit the scope of the invention in any way, compounds such as the ones below are useful as prostaglandin EP 4 agonists.
[0063] C 1-12 alkyl is alkyl having from 1 to 12 carbon atoms, including:
linear alkyl, such as methyl, ethyl, n-propyl, n-butyl, etc.; branched alkyl, such as iso-propyl, iso-butyl, t-butyl, isopentyl, etc.; cyclic alkyl, such as cyclopropyl, cyclobutyl, cyclohexyl, etc.; including substituted cycloalkyl, such as methylcyclohexyl, ethylcyclopropyl, dimethylcycloheptyl, etc, and including moieties such as CH 2 -cyclohexyl, where the cyclic group is not the point of attachment to the rest of the molecule; and any combination of the other types of alkyl groups listed above. Thus, E may be any of these groups. In particular, E may be linear alkyl of C 1-6 , especially butyl. Other particularly useful groups from which E may be selected include, without limitation, cyclohexyl, cyclopentyl, substituted cyclohexyl and cyclobutyl having less than 9 carbon atoms, and the like.
[0068] E may be R 2 or Y—R 2 wherein Y is CH 2 , S or O and R 2 is aryl or heteroaryl. Thus, E may be aryl, heteroaryl, —CH 2 -aryl, —S-aryl, —O-aryl, —CH 2 -heteroaryl, —S-heteroaryl, —O-heteroaryl, and the like.
[0069] Aryl is defined as an aromatic ring or ring system as well as a substituted derivative thereof, wherein one or more substituents are substituted for hydrogen. While not intending to limit the scope of the invention in any way, phenyl, naphthyl, biphenyl, terphenyl, and the like are examples of aryl.
[0070] Heteroaryl is defined as aryl having at least one non-carbon atom in an aromatic ring or ring system. While not intending to limit the scope of the invention in any way, in many cases one or more oxygen, sulfur, and/or nitrogen atoms are present. While not intending to limit the scope of the invention in any way, examples of heteroaryl are furyl, thienyl, pyridinyl, benzofuryl, benzothienyl, indolyl, and the like.
[0071] The substituents of aryl or heteroaryl may have up to 12 non-hydrogen atoms each and as many hydrogens as necessary. Thus, while not intending to limit the scope of the invention in any way, the substituents may be:
hydrocarbyl, such as alkyl, alkenyl, alkynyl, and the like, and combinations thereof; hydrocarbyloxy, meaning O-hydrocarbyl such as OCH 3 , OCH 2 CH 3 , O-cyclohexyl, etc, up to 11 carbon atoms, and the like; hydroxyhydrocarbyl, meaning hydrocarbyl-OH such as CH 2 OH, C(CH 3 ) 2 OH, etc, up to 11 carbon atoms, and the like; nitrogen substituents such as NO 2 , CN, and the like, including amino, such as NH 2 , NH(CH 2 CH 3 OH), NHCH 3 , etc., up to 11 carbon atoms, and the like; carbonyl substituents, such as CO 2 H, ester, amide, and the like; halogen, such as chloro, fluoro, bromo, and the like; fluorocarbonyl, such as CF 3 , CF 2 CF 3 , and the like; phosphorous substituents, such as PO 3 2− , and the like; sulfur substituents, including S-hydrocarbyl, SH, SO 3 H, SO 2 -hydrocarbyl, SO 3 -hydrocarbyl, and the like.
[0081] In certain embodiments, the number of non-hydrogen atoms is 6 or less in a substituent. In certain embodiments, the number of non-hydrogen atoms is 3 or less in a substituent. In certain embodiments, the number of non-hydrogen atoms on a substituent is 1.
[0082] In certain embodiments, the substituents contain only hydrogen, carbon, oxygen, halo, nitrogen, and sulfur. The substituents may contain only hydrogen, carbon, oxygen, and halo.
[0083] In certain embodiments A is —(CH 2 ) 6 —, cis —CH 2 CH═CH—(CH 2 ) 3 —, or —CH 2 C≡C—(CH 2 ) 3 —, wherein 1 or 2 carbon atoms may be substituted with S or O; and E is C 1-6 alkyl, R 2 , or —Y—R 2 wherein Y is CH 2 , S, or O, and R 2 is aryl or heteroaryl.
[0084] In one embodiment R 1 is H, chloro, or fluoro. In one embodiment R 1 is H. In one embodiment, R 1 is chloro.
[0085] R 2 may be phenyl, naphthyl, biphenyl, thienyl, or benzothienyl having from 0 to 2 substituents selected from the group consisting of F, Cl, Br, methyl, methoxy, and CF 3 .
[0086] R 2 may be CH 2 -naphthyl, CH 2 -biphenyl, CH 2 -(2-thienyl), CH 2 -(3-thienyl), naphthyl, biphenyl, 2-thienyl, 3-thienyl, CH 2 -(2-(3-chlorobenzothienyl)), CH 2 -(3-benzothienyl), 2-(3-chlorobenzothienyl), or 3-benzothienyl.
[0087] R 2 may be CH 2 -(2-thienyl), CH 2 -(3-thienyl), 2-thienyl, 3-thienyl, CH 2 -(2-(3-chlorobenzothienyl)), CH 2 -(3-benzothienyl), 2-(3-chlorobenzothienyl), or 3-benzothienyl.
[0088] While not intending to limit the scope of the invention in any way, compounds according to the structures below, wherein x is 0 or 1 and R 1 is H, chloro, fluoro, bromo, methyl, methoxy, or CF 3 , are examples of prostaglandin EP 4 agonists.
[0089] While not intending to limit the scope of the invention in any way, compounds according to the structures below are examples of prostaglandin EP 4 agonists.
[0090] While not intending to limit the scope of the invention in any way, compounds according to the structures below are examples of prostaglandin EP 4 agonists.
[0091] While not intending to limit the scope of the invention in any way, compounds according to the structures below are examples of prostaglandin EP 4 agonists.
[0092] While not intending to limit the scope of the invention in any way, compounds according to the structures below, wherein x is 0 or 1 and R 1 is H, chloro, fluoro, bromo, methyl, methoxy, or CF 3 , are examples of prostaglandin EP 4 agonists.
[0093] While not intending to limit the scope of the invention in any way, compounds according to the structures below are examples of prostaglandin EP 4 agonists.
[0094] Furthermore, the following United States Patent Applications or Patents, all of which are expressly incorporated by reference herein, disclose compounds which are prostaglandin EP 4 agonists: U.S. Pat. No. 6,552,067; U.S. Pat. No. 6,747,054; United States Patent Application Publication No. 20030120079; United States Patent Application Publication No. 20030207925; United States Patent Application Publication No. 20040157901; U.S. Pat. No. 4,117,014; U.S. Patent Application Publication No. 2004/0142969; U.S. Pat. No. 6,747,037; U.S. Pat. No. 6,610,719; U.S. Pat. No. 4,171,375; U.S. Pat. No. 3,931,297; U.S. patent application Ser. No. 821,705, filed Apr. 9, 2004; U.S. Pat. No. 6,670,485; U.S. Pat. No. 6,410,591; and U.S. Pat. No. 6,538,018.
[0095] All prostaglandin EP 4 agonists, pharmaceutically acceptable salts of all prostaglandin EP 4 agonists and prodrugs related to all prostaglandin EP 4 agonists are contemplated herein as prostagiandin EP 4 agonist components.
[0096] Prodrugs of prostaglandin EP 4 agonists comprising
are contemplated herein;
wherein R 4 is H, halo or C 1-6 alkyl.
[0098] Halo is a group 7 atom such as fluoro, chloro, bromo, iodo, and the like.
[0099] C 1-6 alkyl is a linear, branched, or cyclic alkyl having from 1 to 6 carbons including, but not limited to, methyl, ethyl, propyl, butyl, pentyl, hexyl, cyclopropyl, cylobutyl, cyclohexyl, and the like.
[0100] While not intending to limit the scope of the invention in any way, prodrugs of prostaglandin EP 4 agonists according to the structures below are contemplated.
[0101] The term carbohydrate is defined broadly to encompass simple sugars, disaccharides, oligosaccharides, polysaccharides, starches, and the like, whether linear, branched or macrocyclic. The term carbohydrate also refers to one of the foregoing classes of compounds having up to one amine functional group present for every six carbon atoms.
[0102] The esters, ethers, or amide prodrugs herein may incorporate either a direct bond to the carbohydrate or amino acid, or may alternatively incorporate a spacer group including, but not limited to,
polyols such as ethylene glycol, glycerine, and the like, and oligomers and polymers thereof; dicarboxylic acids, such as succinic acid, maleic acid, malonic acid, azelaic acid, and the like; hydroxycarboxylic, acids such as lactic acid, hydroxyacetic acid, citric acid, and the like; polyamines, such as ethylene diamine and the like; and esters, amides, or ethers to form combinations of any of the above.
[0107] In certain embodiments, the prodrug is a glucoside ester or ether. Thus, without limiting the scope of the invention in any way, compounds like those shown below, or pharmaceutically acceptable salts thereof, are useful as prostaglandin EP 4 agonist components in accordance with the present invention.
[0108] Alternatively, the ester or ether bond may occur at a different position on the sugar; i.e. the oxygen of one of the other hydroxyl groups is the oxygen of the ester or ether bond.
[0109] In one embodiment, the prodrug is a glucuronide ester or ether. Thus, without limiting the scope of the invention in any way, compounds like those shown below, or pharmaceutically acceptable salts thereof, are useful as prostaglandin EP 4 agonist components in accordance with the present invention.
[0110] Alternatively, the ester or ether bond may occur at a different position on the sugar; i.e. the oxygen of one of the other hydroxyl groups is the oxygen of the ester or ether bond.
[0111] Other prodrugs are cyclodextrin esters. Cyclodextrins are cyclic oligosaccharides containing 6, 7, or 8 glucopyranose units, referred to as α-cyclodextrin, β-cyclodextrin, or γ-cyclodextrin respectively (structures depicted below).
[0112] Thus, without limiting the scope of the invention in any way, compounds like those shown below, or pharmaceutically acceptable salts thereof, are useful as prostaglandin EP 4 agonist components in accordance with the present invention.
[0113] In any structure disclosed herein, CD indicates a cyclodextrin or a spacer-cyclodextrin, including α-, β-, and γ-cyclodextrin, which may be attached at a 2-, 3-, or 6-hydroxyl group. A 2-, 3-, or 6-hydroxyl group refers to the position on the glucose monomer where the anomeric carbon is 1 and the terminal carbon (in the chain form) is 6. The following examples illustrate this nomenclature.
[0114] For the compound below, CD is α-cyclodextrin linked at a 3-hydroxyl group.
[0115] For the compound below, CD is an ethylene glycol-β-cyclodextrin linked at a 2-hydroxyl group.
[0116] For the compound below, CD is a γ-cyclodextrin linked at a 6-hydroxyl group.
[0117] The CD esters shown below, as well as pharmaceutically acceptable salts thereof, are also useful prostaglandin EP 4 agonist prodrug compounds.
[0118] Dextran esters are also useful prodrugs. Dextran is a polymer of glucose primarily linked of α-D(1→6), i.e. D-glucose units are linked by a bond between an α-hydroxyl group at the anomeric (position 1) carbon and the hydroxyl group at carbon 6.
[0119] The dextran esters shown below are especially useful as prodrugs, as well as their pharmaceutically acceptable salts. Dx is dextran or spacer-dextran, where the O in CO 2 comes from a dextran hydroxyl group or from a spacer bonded to a dextran hydroxyl group, analogous to the structures shown for cyclodextrin esters.
[0120] Amino acid prodrugs are also contemplated, such as in the structures shown below, where R represents the side chain characteristic of a natural amino acid, and where R and the amide nitrogen may be connected as per proline. Pharmaceutically acceptable salts of compounds of these structures, whether anionic, cationic, or zwitterionic, are also useful.
In certain embodiments, R is selected from the group consisting of H, methyl, iso-propyl, sec-butyl, benzyl, indol-3-ylmethyl, hydroxymethyl, CHOHCH 3 , CH 2 CONH 2 , p-hydroxybenzyl, CH 2 SH, (CH 2 ) 4 NH 2 , (CH 2 ) 3 NHC(NH 2 ) 2 + , methylimidizol-5-yl, CH 2 CO 2 H, (CH 2 ) 2 CO 2 H and the like.
[0121] Ester prodrugs of EP 4 agonists may also be based upon amino acids, as demonstrated by the examples shown below. Pharmaceutically acceptable salts of compounds of these structures, whether anionic, cationic, or zwitterionic, are also useful.
[0122] Since amino acids such as serine, threonine, and tyrosine have hydroxyl functional groups in their side chains, ether prodrugs of EP 4 agonists based upon amino acids are also possible, as demonstrated in the examples below. Pharmaceutically acceptable salts of compounds of these structures, whether anionic, cationic, or zwitterionic, are also useful.
[0123] In addition, the spacers illustrated herein may be applied to amino acids to further increase the number and kinds of useful amino acid prodrugs.
[0124] Since a carbohydrate according to the definition given herein may have a limited amount of amine functional groups, carbohydrate amides are also possible such as the ones depicted below.
[0125] Analogous structures could also be drawn with any of the carbohydrate esters shown herein, making a large variety of carbohydrate amides possible for use in the methods disclosed herein. Further, since the prodrugs may incorporate an amine spacer, the number of carbohydrate amides contemplated is further diversified.
[0126] Prodrugs of the compounds shown below, and use of the compounds, or salts or prodrugs thereof, for any method, composition, or treatment disclosed herein, are specifically contemplated herein.
[0127] Unless indicated by a wedge or a dash, a carbon which has a chiral center can be construed to include the S isomer, the R isomer, or any mixture of isomers including a 50:50 R/S mixture. In particular, the pure isomers of each of the structures above, and any possible isomeric mixtures, including the 50:50 R/S mixtures, are contemplated. Methods of preparing these compounds are in U.S. Pat. No. 6,747,037 and U.S. Pat. No. 6,875,787, the disclosure of which are hereby incorporated in their entireties herein by reference.
[0128] There are a number of methods of preparing the prodrug compounds disclosed herein. While not intending to limit the scope of the invention in any way, a glucoside ether of a prostaglandin EP 4 agonist may be prepared from commercially available (Sigma Chemical Co.) 2,3,4,6-tetra-O-acetyl-β-D-glucopyranoside (2) by coupling the two in CCl 4 in the presence of silver carbonate, followed by hydrolysis of the ester protecting groups using a procedure adapted from Friend and Chang ( J. Med. Chem. 1984, 27, 261-266 ; J. Med. Chem. 1985, 28, 51-57).
[0129] In this method, compound 1 is dissolved in dry CCl 4 or another suitable solvent, and freshly prepared Ag 2 CO 3 (about 4.5 equivalents) is added. Compound 2 (about 2.7 equivalents) is then added dropwise while protecting the reaction mixture from light, and continuously distilling the solvent. The distilled solvent is replaced with fresh solvent during the course of the reaction. When the reaction is complete, the solution is worked up according to standard methods and purified by flash chromatography on RP-18 or another suitable purification method to yield compound 3. The ester groups of compound 3 are then saponified according to an art acceptable procedure such as NaOH in MeOH, and worked up and purified according to standard procedures.
[0130] This procedure may be used for prostaglandin EP 4 agonists having a single hydroxyl group. Alternatively, prodrugs for prostaglandin EP 4 agonists having more than 1 hydroxyl group may be prepared by protection of the hydroxyl groups with different groups, so that one may be removed for preparation of a prodrug. Generally, the ring, the α-chain, and the ω-chain are prepared separately and coupled toward the end of the synthetic procedure, so protection with distinct groups for each part is within the ability of a person of ordinary skill in the art.
[0131] A similar procedure may be used to prepare glucouronide ethers. Haeberlin et. al. ( Pharmaceutical Research 1993, 10, 1553-1562) discloses such a procedure which may be adapted here.
[0132] The procedure shown below may be used to link prostaglandin EP 4 agonists to cyclodextrin or to another carbohydrate. Coupling of the succinic acid to cyclodextrin is carried out as described by Tanaka et. al. ( Journal of Antibiotics 1994, 47, 1025-1029), by suspending cyclodextrin in DMF, dissolving the mixture in pyridine, adding 1.2 equivalents of succinic anhydride, and stirring for 18 hours at room temperature. The mixture is poured into chloroform to precipitate the succinate ester product, which is filtered, washed with chloroform and methanol, and purified by an ODS column. Tanaka showed that reaction occurs preferentially at the 6 OH by a ratio of 4.6/1 for succinic anhydride. The preference reaction at the 6-OH is even greater for phthalic anhydride (13.6/1), naphthalene dicarboxylic anhydride (14.0/1), and cyclohexane dicarboxylic anhydride (14.7/1).
[0133] The hydroxyl group of the prostaglandin EP 4 agonist is activated by reacting with p-toluenesulfonyl chloride, and the tosylate 7 is reacted with the cyclodextrin derivative 6 to obtain the prodrug product.
[0134] Alternatively, cyclodextrin may be attached directly to the carboxylic acid of a prostaglandin EP 4 agonist as shown below. This procedure is an adaptation of one disclosed by Uekama and coworkers ( J. Med. Chem. 1997, 40, 2755-2761 and Pharm. Pharacol. 1996, 48, 27-31) which described preparing cyclodextrin prodrugs of anti-inflammatory carboxylic acids such as 4-biphenylacetic acid. This procedure is readily adapted to prostaglandin EP 4 agonists. In this procedure, the cyclodextrin is reacted with p-toluensulfonyl chloride to form the sylate 8, which is purified ion exchange chromatography followed by recrystallization from water. The hydroxyl groups of the prostaglandin are protected with THP by reaction with THPCl. Alternatively, a THP protected prostaglandin EP 4 agonist ester, which is frequently a late stage synthetic intermediate in the preparation of a prostaglandin EP 4 agonist, is saponified to give a THP protected free prostaglandin EP 4 agonist acid. The acid is then reacted with the cyclodextrin tosylate to give the desired prodrug, which is worked up and purified according to methods known in the art.
[0135] The procedure shown below may be used to line prostaglandin EP4 agonist analogs to dextran or to another carbohydrate. A procedure for the coupling of dexamethasone to dextran via a succinate linkage (McLeod et. al., Int J. Pharm. 1993, 92, 105-114) is readily adapted to the compounds herein. While not intending to limit the scope of the invention in any way, this procedure is most conveniently carried out with a prostaglandin EP 4 agonist having no free carboxylic acid (e.g. an ester) and 1 unprotected hydroxyl group. Connection to dextran to form the prodrug occurs at the free hydroxyl group. In this procedure, a hemisuccinate is formed from a hydroxyl group of a prostaglandin EP 4 agonist by adding it to succinic anhydride to form the hemisuccinate ester. The prostaglandin EP 4 agonist hemisuccinate is then reacted with 2 equivalents of 1,1-carbonyldiimidizole for 30 minutes under nitrogen. Dextran and a base such as triethylamine is added and the reaction is stirred for about 21 hours at room temperature. Any protecting groups on other hydroxyl groups may then be removed by stirring in dilute acid or another method appropriate to the protecting group being used. The carboxylic acid need not be deprotected because the ester will readily hydrolyze in vivo.
[0136] The carbohydrates used in the procedures described above are easily varied or interchanged by a person of ordinary skill in the art. For example, glucoside and glucouronide esters of the carboxylic acid of the prostaglandin EP 4 agonist may be prepared using the tosylate of the carbohydrate in a procedure analogous to that described for cyclodextrin.
[0137] Amino acid prodrugs are readily obtained by many methods. For example, while not intending to be limiting, one of several procedures used for the coupling of salicylic acid to a methyl ester of alanine, glycine, methionine, or tyrosine (Nakamura et. al. J. Pharm. Pharmacol. 1992, 44, 295-299, and Nakamura et. al. Int. J. Pharm. 1992, 87, 59-66) can be adapted for use with prostaglandin EP 4 agonists. In this procedure, an equimolar amount of dicyclohexylcarbodiimide is added at or below 0° C. to a prostaglandin EP 4 agonist carboxylic acid and stirred about 30 minutes. An equimolar amount of the methyl ester of the amino acid is then added and stirred overnight at room temperature to form the amide. Deprotection of any hydroxyl group can then be carried out by using dilute aqueous acid or another method, depending on the protecting group.
[0138] A number of methods of delivering a drug to the gastrointestinal tract, or desired portion thereof, via oral dosage forms, for example, solid forms, semi-solid forms, aqueous and non-aqueous liquid forms, including but not limited to, emulsions, liquid suspensions, solutions and the like, are known in the art. These include, without limitation, 1) administration, for example, oral administration, of the drug with compatible excipients, for example, conventional excipients, including, without limitation, oils, such as hydrogenated caster oil, and the like and mixtures thereof; cellulosic derivatives and starch derivatives, such as alkyl celluloses, hydroxyl alkyl celluloses, alkali metal starch carboxylates, e.g., sodium starch glycolate, and the like and mixtures thereof; and sugars and sugar derivatives and the like and mixtures thereof; so that the drug is released in the upper gastrointestinal tract, for example, esophagus, stomach, duodenum, and the like, 2) administration, for example, oral administration, of a prodrug with compatible excipients, for example, conventional excipients, for example, as noted above, with the prodrug being selected so that the drug is released in the upper gastrointestinal tract and/or lower gastrointestinal tract, as desired, 3) coating the drug and/or prodrug with, or encapsulating or impregnating the drug and/or prodrug into, a polymer designed for delivery to the lower gastrointestinal tract, 4) time released delivery of the drug and/or prodrug, 5) use of a bioadhesive system, and the like.
[0139] If desired, the presently useful compositions or dosage forms may additionally comprise other pharmaceutically acceptable excipients, such as tonicity components, buffer components, polyelectrolyte components, thickeners, fillers, diluents, flavoring agents, coloring agents, antioxidants, preservatives, such as antibacterial or antifungal agents, acids and/or bases to adjust pH, and the like and mixtures thereof. Each such additive, if present, may typically comprise about 0.0001% or less or about 0.01% or less to about 10% or more by weight of the composition. Such additives include those additives which are conventional and/or well known for use in similar pharmaceutical compositions. For example, suitable thickening agents include any of those known in the art, as for example pharmaceutically acceptable polymers and/or inorganic thickeners. Such agents include, but are not limited to, polyacrylate homo- and co-polymers; celluloses and cellulose derivatives; polyvinyl pyrrolidones; polyvinyl resins; silicates; and the like and mixtures thereof.
[0140] In one embodiment, the use of an azo-based prodrug may be employed to provide the drug in the lower gastrointestinal tract. Lower intestinal microflora are believed to be capable of reductive cleavage of an azo bond leaving the two nitrogen atoms as amine functional groups. Bacteria of the lower gastrointestinal tract also have enzymes which can digest glycosides, glucuronides, cyclodextrins, dextrans, and other carbohydrates, and ester prodrugs formed from these carbohydrates have been shown to deliver the parent active drugs selectively to the lower gastrointestinal tract.
[0141] Carbohydrate polymers including, without limitation, amylase, arabinogalactan, chitosan, chondroiton sulfate, dextran, guar gum, pectin, xylin, and the like and mixtures thereof, can be used to coat a drug and/or prodrug, or a drug and/or prodrug may be impregnated or encapsulated in the polymer. After oral administration, the polymers remain stable in the upper gastrointestinal tract, but are digested by the microflora of the lower gastrointestinal tract thus releasing the drug for therapeutic effect.
[0142] Polymers which are sensitive to pH may also be used since the lower gastrointestinal tract has a higher pH than the upper gastrointestinal tract. Such polymers are commercially available. For example, Rohm Pharmaceuticals, Darmstadt, Germany, markets pH dependent methacrylate based polymers and copolymers sold under the trademark Eudragit®, which have varying solubilities over different pH ranges based upon the number of free carboxylate groups in the polymer. Time release systems, bioadhesive systems, and other delivery systems may also be employed.
[0143] Coadministration of prostaglandin EP 4 agonists with one or more other, e.g., different, drugs, either in a single composition or in separate dosage forms, is also contemplated. While not intending to limit the scope of the invention in any way, other drugs which may be included in combination therapies with prostaglandin EP 4 agonists and their prodrugs include, but are not limited to:
Anti-inflammatory drugs, such as non-selective COX inhibitors and selective COX-2 inhibitors including, diclofenac, flurbiprofen, naproxen, suprofen, ibuprofen, ketorolac, piroxicam and the like and mixtures thereof; indoles, such as indomethacin and the like; diarylpyrazoles, such as celecoxib and the like; pyrrolo pyrroles; other agents that inhibit prostaglandin synthesis; aminosalicylates; other non-steroidal anti-inflammatory drugs, and the like and mixtures thereof; Steroids, such as hydrocortisone, cortisone, prednisolone, prednisone, dexamethasone, medrysone, fluorometholone, estrogens, progesterones, and the like and mixtures thereof Immunomodulators, such as azathioprine, 6-mercaptopurine, cyclosporine, and the like and mixtures thereof; and Humanized monoclonal antibodies against pro-inflammatory cytokines, such as infliximab, etanercept, onercept, adalimumab, CDP571, CDP870, natalizumab, MLN-02, ISIS 2302, cM-T412, BF-5, vasilizumab, daclizumab, basiliximab, Anti-CD40L, and the like and mixtures thereof.
[0148] Such other drug or drugs are administered in amounts effective to provide the desired therapeutic effect or effects.
[0149] One useful assay for determining prostaglandin EP 4 activity and selectivity of compounds is described below.
[0150] Human Recombinant EP 1 , EP 2 , EP 3 , EP 4 , FP, TP, IP and DP Receptors: Stable Transfectants.
[0151] Plasmids encoding the human EP 1 , EP 2 , EP 3 , EP 4 , FP, TP, IP and DP receptors are prepared by cloning the respective coding sequences into the eukaryotic expression vector pCEP 4 (Invitrogen). The pCEP 4 vector contains an Epstein Barr virus (EBV) origin of replication, which permits episomal replication in primate cell lines expressing EBV nuclear antigen (EBNA-1). It also contains a hygromycin resistance gene that is used for eukaryotic selection. The cells employed for stable transfection are human embryonic kidney cells (HEK-293) that are transfected with and express the EBNA-1 protein. These HEK-293-EBNA cells (Invitrogen) are grown in medium containing Geneticin (G418) to maintain expression of the EBNA-1 protein. HEK-293 cells are grown in DMEM with 10% fetal bovine serum (FBS), 250 μg ml −1 G418 (Life Technologies) and 200 μg ml −1 gentamicin or penicillin/streptomycin. Selection of stable transfectants is achieved with 200 μg ml −1 hygromycin, the optimal concentration being determined by previous hygromycin kill curve studies.
[0152] For transfection, the cells are grown to 50-60% confluency on 10 cm plates. The plasmid pCEP 4 incorporating cDNA inserts for the respective human prostanoid receptor (20 μg) is added to 500 μl of 250 mM CaCl 2 . HEPES buffered saline ×2 (2×HBS, 280 mM NaCl, 20 mM HEPES acid, 1.5 mM Na 2 HPO 4 , pH 7.05-7.12) is then added dropwise to a total of 500 μl, with continuous vortexing at room temperature. After 30 min, 9 ml DMEM are added to the mixture. The DNA/DMEM/calcium phosphate mixture is then added to the cells, which is previously rinsed with 10 ml PBS. The cells are then incubated for 5 hr at 37° C. in humidified 95% air/5% CO 2 . The calcium phosphate solution is then removed and the cells are treated with 10% glycerol in DMEM for 2 min. The glycerol solution is then replaced by DMEM with 10% FBS. The cells are incubated overnight and the medium is replaced by DMEM/10% FBS containing 250 μg ml −1 G418 and penicillin/streptomycin. The following day hygromycin B is added to a final concentration of 200 μg ml −1 .
[0153] Ten days after transfection, hygromycin B resistant clones are individually selected and transferred to a separate well on a 24 well plate. At confluence each clone is transferred to one well of a 6 well plate, and then expanded in a 10 cm dish. Cells are maintained under continuous hygromycin selection until use.
Radioligand Binding
[0154] Radioligand binding studies on plasma membrane fractions prepared from cells are performed as follows. Cells washed with TME buffer are scraped from the bottom of the flasks and homogenized for 30 sec using a Brinkman PT 10/35 polytron. TME buffer is added as necessary to achieve a 40 ml volume in the centrifuge tubes. TME is comprised of 50 mM TRIS base, 10 mM MgCl 2 , 1 mM EDTA; pH 7.4 is achieved by adding 1 N HCl. The cell homogenate is centrifuged at 19,000 rpm for 20-25 min at 4° C. using a Beckman Ti-60 or Tι-70 rotor. The pellet is then resuspended in TME buffer to provide a final protein concentration of 1 mg/ml, as determined by Bio-Rad assay. Radioligand binding assays are performed in a 100 μl or 200 μl volume.
[0155] The binding of [ 3 H] PGE 2 (specific activity 165 Ci/mmol) is determined in duplicate and in at least 3 separate experiments. Incubations are for 60 min at 25° C. and are terminated by the addition of 4 ml of ice-cold 50 mM TRIS-HC1 followed by rapid filtration through Whatman GF/B filters and three additional 4 ml washes in a cell harvester (Brandel). Competition studies are performed using a final concentration of 2.5 or 5 nM [ 3 H] PGE 2 and non-specific binding is determined with 10 −5 M unlabelled PGE 2 .
[0156] For all radioligand binding studies, the criteria for inclusion are >50% specific binding and between 500 and 1000 displaceable counts or better.
[0157] The dosage of the prostaglandin EP 4 agonist component employed in accordance with the present invention varies over a relatively wide range and depends on a number of factors well known in the medicinal arts including, but not limited to, the weight of the individual to whom the agonist component is administered, the general health status/condition of such individual, the disease/condition sought to be treated/prevented by such administration, the severity of such disease/condition in such individual, the specific agonist component being administered, the sensitivity of such individual to the specific agonist component being administered, the mode of administration, the age of such individual, the sex of such individual, the pregnancy status of such individual, the other ongoing drug therapies being administered to such individual and the like factors.
[0158] The amount of prostaglandin EP 4 agonist component employed on a daily basis for each human or animal may be in a range of about 0.1 mg to about 30 mg or about 50 mg or about 100 mg or about 150 mg or about 200 mg or more. In one embodiment, such daily amount may be in a range of about 5 mg to about 150 mg or about 200 mg or more. The prostaglandin EP 4 agonist component may be administered in one or more doses daily, for example, once daily, twice daily, three times daily or more frequently. In one embodiment, once daily dosage is useful.
[0159] The duration of treatment with a prostaglandin EP 4 agonist component may vary over a wide range of times depending, for example, on factors many of which have been identified elsewhere herein. In general, the prostaglandin EP 4 agonist component is administered for a period of time sufficient to obtain the desired therapeutic effect or effects. The duration of treatment may be, for example, in a range of about 1 day or about 3 days or about 1 week or about 2 weeks to about 4 weeks or about 8 weeks or about 12 weeks or about 20 weeks or longer. In one useful embodiment, the duration of treatment is in a range of about 2 weeks to about 12 weeks.
[0160] The following non-limiting examples illustrate certain aspects of the present invention.
EXAMPLES 1 AND 2
[0161] A series of four (4) tablet compositions are produced using two (2) different prostaglandin EP 4 agonists and two (2) different prostaglandin EP 4 agonist prodrugs. Each of the tablet compositions is prepared as follows.
[0162] Within a dust containment area, a mixture of ingredients is prepared and blended until the mixture is uniform. The uniform mixture, having a composition as listed in the table directly below, is then used in a conventional tabletting machine to produce 100 mg tablets having such composition. The tablets may be packaged, for example, in high density polyethylene bottles, with appropriate silica gel packs, capped and labeled,
[0163] The mixtures and tablets have the following make-ups:
Composition 1 2 3 4 Ingredient wt. % wt. % wt. % wt. % Prostaglandin EP 4 10.0 — — — Agonist 1 (1) Prostaglandin EP 4 — 10.0 — — Agonist Prodrug 1 (2) Prostaglandin EP 4 — — 10.0 — Agonist 2 (3) Prostaglandin EP 4 — — — 10.0 Agonist Prodrug 2 (4) Sugar 50.0 50.0 50.0 50.0 Excipients (5) 40.0 40.0 40.0 40.0 (1) (2) An isopropyl ester of (1) above. (3) (4) An isopropyl ester of (3) above. (5) A mixture of conventional pharmaceutical excipients useful, for exam- ple, as fillers, tabletting aids, bulking agents, preservatives, buffers and the like. Examples include, but are not limited to, mixtures of hydrogenated caster oil, hydroxyl ethyl cellulose, sodium starch glycolate, sorbitol and the like.
[0164] Each of the tablets that is produced in Examples 1 to 4 includes about 10 mg of the agonist or prodrug, as the case may be, which the total weight of each tablet being about 100 mg.
EXAMPLES 5 TO 8
[0165] A series of four (4) capsule compositions are produced using two (2) prostaglandin EP 4 agonists and two (2) prostaglandin EP 4 agonist prodrugs. Each of these capsule compositions is prepared as follows.
[0166] Within a dust containment area, small sugar spheres are provided. An aqueous mixture of the agonist or prodrug including a binder/sealer, such as Opadry® clear, is provided and is sprayed onto the sugar spheres using a conventional fluid bed spraying system. A second mixture including a binder/sealer, e.g., Opadry® clear, in a liquid carrier is sprayed onto the first sprayed spheres using a conventional fluid bed spraying system. This step results in agonist or prodrug loaded pellets with a sealing coat.
[0167] These pellets are coated with an aqueous mixture of triethyl citrate, talc and a methacrylic acid copolymer using a conventional fluid bed spraying system. This step results in agonist or prodrug loaded pellets with a sealing coat and an outer enteric coating. These pellets are encapsulated in natural transparent hard shell gelatin capsules. The filled capsules may be packaged, for example, in high density polyethylene bottles, with appropriate silica gel packs, capped and labeled.
[0168] The pellets with the enteric coating have the following make-ups.
Composition 5 6 7 8 Ingredient wt. % wt % wt % wt % Prostaglandin EP 4 35.5 — — — Agonist 1 (1) Prostaglandin EP 4 — 35.5 — — Agonist Prodrug 1 (2) Prostaglandin EP 4 — — 35.5 — Agonist Prodrug 2 (3) Prostaglandin EP 4 — — — 35.5 Agonist Prodrug 2 (4) Sugar Spheres 33.5 33.5 33.5 33.5 Binder/Sealer 11.0 11.0 11.0 11.0 Methacrylic Acid 14.8 14.8 14.8 14.8 Copolymer (5) Talc (6) 3.7 3.7 3.7 3.7 Triethyl Citrate (7) 1.5 1.5 1.5 1.5 (1) (2) A dextran ester of (1) above. (3) (4) A dextran ester of (3) above. (5) Enteric coating composition identified as Eudragit ® L30-D55 sold by Rohm Pharmaceuticals. (6) Useful as a glidant (7) Useful as a plasticizer
[0169] Each of the capsules that is produced in Examples 5 to 8 includes about 35.5 mg of the agonist or prodrug.
EXAMPLES 9 TO 12
[0170] Four adult humans are diagnosed with esophageal ulcers. Each of these people orally takes a tablet produced as described in Examples 1 to 4 having a different one of Compositions 1 to 4 once daily for twelve weeks. At the end of this period of time, each of the humans reports substantial relief from the esophageal ulcers. The pain and/or other symptoms of the ulcers have been reduced. In addition the ulcers have been reduced in size or substantially completely healed.
EXAMPLES 13 TO 16
[0171] Four adult humans are diagnosed with duodenal ulcers. Each of these people orally takes a tablet (produced as described in Examples 1 to 4) having a different one of Compositions 1 to 4 once daily for twelve weeks. At the end of this period of time, each of the humans reports substantial relief from the duodenal ulcers. The pain and/or other symptoms of the ulcers have been reduced. In addition the ulcers have been reduced in size or substantially completely healed.
EXAMPLES 17 TO 20
[0172] Four adult humans are diagnosed with alcohol gastropathy. Each of these people orally takes a tablet (produced as described in Examples 1 to 4) having a different one of Compositions 1 to 4 once daily for twelve weeks. At the end of this period of time, each of the humans reports substantial relief from the alcohol gastropathy. The pain and/or other symptoms of this disease have been reduced.
EXAMPLES 21 TO 24
[0173] Four adult humans are diagnosed with non-steroidal anti-inflammatory drug induced gastroenteropathy. Each of these people orally takes a tablet (produced as described in Examples 1 to 4) having a different one of Compositions 1 to 4 once daily for twelve weeks. At the end of this period of time, each of the humans reports substantial relief from the non-steroidal anti-inflammatory drug induced gastroenteropathy. The pain and/or other symptoms of this disease have been reduced.
EXAMPLES 25 TO 28
[0174] Four adult humans are diagnosed with intestinal ischemia. Each of these people orally takes a capsule (produced as described in Examples 5 to 8) containing pellets of a different one of Compositions 5 to 8 once daily for twelve weeks. At the end of this period of time, each of the humans reports substantial relief from the intestinal eschemia. The pain and/or other symptoms of this disease have been reduced.
[0175] All references, articles, patents, applications and publications set forth above are incorporated herein by reference in their entireties.
[0176] While this invention has been described with respect to various specific examples and embodiments, it is to be understood that the invention is not limited thereto and that it can be variously practiced within the scope of the following claims.
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Methods are provides directed to administering a therapeutically effective amount of a prostaglandin EP 4 agonist component to a mammal afflicted with or prone to affliction with a disease or condition selected from an esophageal ulcer, alcohol gastropathy, a duodenal ulcer, non-steroidal anti-inflammatory drug-induced gastroentroeropathy and intestinal ischemia. Such administration results in treating or preventing the disease or condition.
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This application is a Continuation-in-Part of application Ser. No. 10/145,209 filed on May 13, 2002 now abandoned.
FIELD OF THE INVENTION
This invention relates generally to absorption spectroscopy and, in particular, is directed to the activation and deactivation of a light source for use with an optical resonator for cavity ring-down spectroscopy.
BACKGROUND OF THE INVENTION
Referring now to the drawing, wherein like reference numerals refer to like elements throughout, FIG. 1 illustrates the electromagnetic spectrum on a logarithmic scale. The science of spectroscopy studies spectra. In contrast with sciences concerned with other parts of the spectrum, optics particularly involves visible and near-visible light—a very narrow part of the available spectrum which extends in wavelength from about 1 mm to about 1 nm. Near visible light includes colors redder than red (infrared) and colors more violet than violet (ultraviolet). The range extends just far enough to either side of visibility that the light can still be handled by most lenses and mirrors made of the usual materials. The wavelength dependence of optical properties of materials must often be considered.
Absorption-type spectroscopy offers high sensitivity, response times on the order of microseconds, immunity from poisoning, and limited interference from molecular species other than the species under study. Various molecular species can be detected or identified by absorption spectroscopy. Thus, absorption spectroscopy provides a general method of detecting important trace species. In the gas phase, the sensitivity and selectivity of this method is optimized because the species have their absorption strength concentrated in a set of sharp spectral lines. The narrow lines in the spectrum can be used to discriminate against most interfering species.
In many industrial processes, the concentration of trace species in flowing gas streams and liquids must be measured and analyzed with a high degree of speed and accuracy. Such measurement and analysis is required because the concentration of contaminants is often critical to the quality of the end product. Gases such as N 2 , O 2 , H 2 , Ar, and He are used to manufacture integrated circuits, for example, and the presence in those gases of impurities—even at parts per billion (ppb) levels—is damaging and reduces the yield of operational circuits. Therefore, the relatively high sensitivity with which water can be spectroscopically monitored is important to manufacturers of high-purity gases used in the semiconductor industry. Various impurities must be detected in other industrial applications. Further, the presence of impurities, either inherent or deliberately placed, in liquids have become of particular concern of late.
Spectroscopy has obtained parts per million (ppm) level detection for gaseous contaminants in high-purity gases. Detection sensitivities at the ppb level are attainable in some cases. Accordingly, several spectroscopic methods have been applied to such applications as quantitative contamination monitoring in gases, including: absorption measurements in traditional long pathlength cells, photoacoustic spectroscopy, frequency modulation spectroscopy, and intracavity laser absorption spectroscopy. These methods have several features, discussed in U.S. Pat. No. 5,528,040 issued to Lehmann, which make them difficult to use and impractical for industrial applications. They have been largely confined, therefore, to laboratory investigations.
In contrast, continuous wave-cavity ring-down spectroscopy (CW-CRDS) has become an important spectroscopic technique with applications to science, industrial process control, and atmospheric trace gas detection. CW-CRDS has been demonstrated as a technique for the measurement of optical absorption that excels in the low-absorbance regime where conventional methods have inadequate sensitivity. CW-CRDS utilizes the mean lifetime of photons in a high-finesse optical resonator as the absorption-sensitive observable.
Typically, the resonator is formed from a pair of nominally equivalent, narrow band, ultra-high reflectivity dielectric mirrors, configured appropriately to form a stable optical resonator. A laser pulse is injected into the resonator through a mirror to experience a mean lifetime which depends upon the photon round-trip transit time, the length of the resonator, the absorption cross section and number density of the species, and a factor accounting for intrinsic resonator losses (which arise largely from the frequency-dependent mirror reflectivities when diffraction losses are negligible). The determination of optical absorption is transformed, therefore, from the conventional power-ratio measurement to a measurement of decay time. The ultimate sensitivity of CW-CRDS is determined by the magnitude of the intrinsic resonator losses, which can be minimized with techniques such as superpolishing that permit the fabrication of ultra-low-loss optics.
FIG. 2 illustrates a conventional CW-CRDS apparatus 200 . As shown in FIG. 2 , light is generated from a narrow band, tunable, continuous wave diode laser 202 . Laser 202 is temperature tuned by a temperature controller (not shown) to put its wavelength on the desired spectral line of the analyte. An acousto-optic modulator (AOM) 204 is positioned in front of and in line with the radiation emitted from laser 202 . AOM 204 provides a means for providing light 206 from laser 202 along the optical axis 219 of resonant cavity 218 . Light 206 exits AOM 204 and is directed by mirrors 208 , 210 to cavity mirror 220 as light 206 a . Light travels along optical axis 219 and exponentially decays between cavity mirrors 220 and 222 . The measure of this decay is indicative of the presence or lack thereof of a trace species. Detector 212 is coupled between the output of optical cavity 218 and controller 214 . Controller 214 is coupled to laser 202 , processor 216 , and AOM 204 . Processor 216 processes signals from optical detector 212 in order to determine the level of trace species in optical resonator 218 .
In AOM 204 , a pressure transducer (not shown) creates a sound wave that modulates the index of refraction in an active nonlinear crystal (not shown), through a photoelastic effect. The sound wave produces a Bragg diffraction grating that disperses incoming light into multiple orders, such as zero order and first order. Different orders have different light beam energy and follow different beam directions. In CW-CRDS, typically, a first order light beam 206 is aligned along with optical axis 219 of cavity 218 incident on the cavity in-coupling mirror 220 , and a zero order beam 224 is idled with a different optical path (other higher order beams are very weak and thus not addressed). Thus, AOM 204 controls the direction of beams 206 , 224 .
When AOM 204 is on, most light power (typically, up to 80%, depending on size of the beam, crystals within AOM 204 , alignment, etc.) goes to the first order along optical axis 219 of resonant cavity 218 as light 206 . The remaining beam power goes to the zero order (light 224 ), or other higher orders. The first order beam 206 is used for the input coupling light source; the zero order beam 224 is typically idled or used for diagnostic components. Once light energy is built up within the cavity, AOM 204 is turned off. This results in all the beam power going to the zero order as light 224 , and no light 206 is coupled into resonant cavity 218 . The stored light energy inside the cavity follows an exponential decay (ring down).
In order to “turn off” the laser light to optical cavity 218 , and thus allow for energy within optical cavity 218 to “ring down,” AOM 204 , under control of controller 214 and through control line 224 , redirects (deflects) light from laser 204 along path 224 and, thus, away from optical path 219 of optical resonator 218 . This conventional approach has drawbacks, however, in that there are losses of light energy primarily through the redirecting means contained within the AOM. Other losses may also be present due to mirrors 208 , 210 used to direct light from AOM 204 to optical cavity 218 . It is estimated that only 50%-80% of light emitted by laser 202 eventually reaches optical resonator 218 as light 206 a due to these losses. Furthermore, these conventional systems are costly and the AOM requires additional space and AOM driver (not shown) within the system.
To overcome the shortcomings of conventional systems, an improved system and method for providing and controlling laser light to a resonant cavity is provided. An object of the present invention is to replace the conventional AOM/control system with a simplified and cost effective control system.
SUMMARY OF THE INVENTION
To achieve that and other objects, and in view of its purposes, the present invention provides an improved apparatus and method for controlling a light source for use with a resonant cavity. The apparatus includes a controller for receiving a comparison of a detection signal and a predetermined threshold, the comparator generating a control signal to one of activate and deactivate the light source based on the comparison; a first delay circuit coupled to the controller for generating a first delay signal to the controller; and a second delay circuit coupled to the comparator and the controller for generating a second delay signal to the controller based on the comparison of the detection signal and the predetermined threshold.
According to another aspect of the invention, the light source provides light as an input to the resonant cavity to measure the presence of an analyte in the resonant cavity.
According to a further aspect of the invention, light from the source is coupled to the resonant cavity by an optical fiber.
According to yet another aspect of the invention, a collimator couples the light into the resonant cavity.
According to still another aspect of the invention, a comparator generates an output signal to the controller based on a comparison of the detection signal and a predetermined threshold.
According to yet a further aspect of the invention, a detector is coupled between the output of the resonant cavity and the comparator, and generates a signal based on the light output from the resonant cavity.
According to another aspect of the invention, the light source is deactivated once the signal generated from the detector exceeds the level of the threshold voltage.
According to yet another aspect of the invention, the first delay circuit is activated on the deactivation of the light source.
According to yet another aspect of the invention, the second delay circuit allows for the stabilization of the light source after re-energizing prior to a new set of data being examined.
According to yet another aspect of the invention, the light source is activated after an end of the first delay period.
According to yet another aspect of the invention, after an end of the first delay period, the light source is activated and energy builds up within the cavity through the current modulation.
According to still another aspect of the invention, an analyte level present in the resonant cavity is measured during the first delay period.
According to yet a further aspect of the invention, the controller deactivates the light source by shunting a supply of current for the light source.
According to yet another aspect of the invention, the light source is a laser.
According to still a further aspect of the invention, an algorithm is used to set the threshold voltage through the use of a digital to analog converter. This algorithm is used to establish the best cavity signal to noise ratio.
The method includes the steps of, detecting a light energy signal output from the resonant cavity; comparing the detected signal with a predetermined threshold; generating a control signal to control the light source based on the comparison; generating a first delay signal to the controller; generating a second delay signal after the end of the first delay signal; providing a current modulation; and measuring a level of the analyte after an end of the second delay signal.
It is to be understood that both the foregoing general description and the following detailed description are exemplary, but are not restrictive, of the invention.
BRIEF DESCRIPTION OF THE DRAWING
The invention is best understood from the following detailed description when read in connection with the accompanying drawing. It is emphasized that, according to common practice, the various features of the drawing are not to scale. On the contrary, the dimensions of the various features are arbitrarily expanded or reduced for clarity. Included in the drawing are the following figures:
FIG. 1 illustrates the electromagnetic spectrum on a logarithmic scale;
FIG. 2 illustrates a prior art CW-CRDS system;
FIG. 3A illustrates an exemplary embodiment of the present invention;
FIG. 3B illustrates another exemplary embodiment of the present invention;
FIG. 4 is an illustration of an exemplary controller of the present invention;
FIG. 5A is a graph illustrating various delay timing according to an exemplary embodiment of the present invention;
FIG. 5B is a partial timing diagram of certain signals according to an exemplary embodiment of the present invention; and
FIG. 6 is a flow chart according to an exemplary embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 3A illustrates an exemplary embodiment of the present invention. As shown in FIG. 3A , light is generated from light source 302 , such as a narrow band, tunable, continuous wave diode laser. Light source 302 is temperature tuned by a temperature controller (not shown) to put its wavelength on the desired spectral line of the analyte of interest. Light energy from light source 302 is coupled to fiber collimator 308 through optical fiber 304 . Light energy 306 is, in turn, provided by collimator 308 to resonant cavity 318 and substantially parallel to its optical axis 319 . Detector 312 is coupled to the output of optical cavity 318 . In turn, detector 312 generates an output signal 313 and provides this signal to controller 314 and data analysis system 316 . Controller 314 is coupled to light source 302 and data analysis system 316 . Data analysis system 316 , such as a personal computer or other specialized processor, processes signals 313 received from optical detector 312 , in accordance with commands from controller 314 , in order to determine the level of trace species (analyte) in optical resonator 318 .
Desirably, light source 302 is a temperature and current controlled, tunable, narrow line-width radiation, semiconductor laser operating in the visible to near- and middle-infrared spectrum. Alternatively, light source 302 may be an external-cavity semiconductor diode laser.
Resonant cavity 318 desirably comprises at least a pair of high reflectivity mirrors 320 , 322 and a gas cell 321 on which the mirrors are mounted. Cell 321 can be flow cell or vacuum cell, for example. Alternatively, and as shown in FIG. 3B , resonant cavity 318 may be comprised of a pair of prisms 324 , 326 and a corresponding gas cell 321 .
Detector 312 is desirably a photovoltaic detector, such as photodiodes or photo-multiplier tubes (PMT), for example.
Referring now to FIG. 4 , a detailed block diagram of controller 314 is shown. As shown in FIG. 4 , buffer 402 receives signal 313 (representing the ring down signal) from detector 312 (shown in FIGS. 3A-3B ). Comparator 406 receives buffered signal 313 and performs a comparison with a threshold signal 404 generated by data analysis system 316 which, in one exemplary embodiment, is converted from a digital signal to an analog signal by threshold DAC 405 . In operation, threshold signal 404 is incremented upward or downward to obtain the maximum signal level from detector 312 . An exemplary process for this is illustrated in FIG. 6 . As a result, threshold signal 404 is based on the level of the ring down signal which has the greatest signal to noise ratio. The output of comparator 406 is provided as an input to control circuit 408 .
Referring now to FIG. 6 , an exemplary flow chart for threshold control is illustrated. At Step 600 , threshold control is initialized. This may be accomplished as part of system initialization or under control of Data Analysis System 316 , for example. At Step 602 , an initial threshold value is set. At Step 604 , a determination is made whether a ring-down occurred within a predetermined time period, such as about one second, for example. If a ring-down occurred Step 608 is entered, otherwise Step 606 is entered. At Step 606 , because a ring-down did not occur, the threshold voltage is decremented and Step 604 is re-entered. At Step 608 , because a ring-down did occur, the threshold voltage is incremented and Step 604 is re-entered. This process is repeated as desired. In this way, an optimum signal to noise ratio is obtained.
At time t 0 + , control circuit 408 generates control signal 408 a , based on the rise of the ring down signal crossing the threshold level, in order to activate first delay circuit 412 (via control signal 408 a ) while simultaneously turning off light source 302 through switch circuit 410 and driver 416 (via control signal 408 c ). At the end of the first delay period t 1 (at subsequent time t 0 as shown in FIG. 5A ), signal 412 a is generated by first delay circuit 412 and provided to control circuit 408 . In turn, control circuit 408 generates signal 408 b to activate second delay circuit 414 , and provides an active signal 408 c (previously deactivated at the beginning of the first delay period) to switch circuit 410 , which in turn activates light source 302 (shown in phantom and described above with respect to FIGS. 3A and 3B ). At the end of delay period t 2 (shown in FIG. 5A ), second delay circuit 414 generates signal 414 a and provides it to control circuit 408 to indicate that light source 302 has stabilized and to begin a third time period t 3 (shown in FIG. 5A ). Time period t 3 (described in detail below with respect to FIG. 5A ) is used to ensure that resonant cavity 318 is fully charged through current modulation with light energy prior to measuring analyte concentration. At the end of time period t 3 , which it should be noted is a time period such that cell 318 is sufficiently charged with light energy, control signal 408 c is deactivated, which in turn is used by switch circuit 410 (and, in one exemplary embodiment, driver 416 ) to deactivate light source 302 . In one embodiment of the present invention, switch circuit 410 shunts current from light source 302 using convention power devices to deactivate light source 302 .
It should be noted that although terms such as active, inactive, activate, and/or deactivate as used, one of skill in that art will readily recognize and appreciate that the exemplary signal levels are arbitrary and may for example be inverted from those discussed. Further, although certain signals may be shown as maintaining a particular level throughout a particular time period, it is also possible that a level transition is all that may be required (such as a pulse) to accomplish the desired result.
Coincident with the deactivation of signal 408 c , signal 408 d is also generated and provided to data analysis system 316 (shown in phantom and described above with respect to FIGS. 3A and 3B ). Although signal 408 c and 408 d are shown as separate signals, it may be preferable to combine them into a single control signal if desired. In such an approach conditioning of signal 408 c may be required to provide a convenient control signal logic level (based on digital signals, for example) to provide proper control of data analysis system 316 .
Signal 408 d (in the two-signal 408 c / 408 d approach) is used by data analysis system 316 to indicate that light source 302 has been deactivated and that the measurement of the analyte should begin. In other words, during the period that control signal 408 d is inactive data analysis system 316 is prevented from accepting new data represented by signal 313 . At this point, the process repeats itself to measure successive ring downs by once again initializing first delay circuit 412 through control circuit 408 . FIG. 5B illustrates a exemplary timing diagram for various ones of the aforementioned control signals.
Table 1 lists system status at various times set forth in FIG. 5A .
TABLE 1
TIME
STATUS
Initial t 0
Light source ON; Delay circuits OFF; Wait State
t 0 +
Sufficient energy build up in resonant cavity;
Activate first delay circuit; Turn off light source;
Subsequent t 0
End of t 1 delay period; Turn on Light Source; Begin
time delay t 2 ; (Cycle repeats)
Because the above description relates to ongoing measurement of analytes, the circuit needs to be initialized prior to the first measurement. To accomplish this initialization, an initialization signal 420 may be provided as an input to control circuit 408 . Upon activation of initialization signal 420 , such as through a button, control signal from data analysis system 316 , or an automatic reset at power-up, for example, delay time t 0 begins. The process then follows the procedure outlined above.
In one exemplary embodiment, switch circuit 410 functions as a current switch/shunt for enabling/disabling current drive to light source 302 .
As a result, controller 314 energizes light source 302 to generate energy into resonant cavity 318 , employs a first delay to allow light energy from light source 302 to completely ring down and be captured by data analysis system 316 . A second delay then allows light source 302 to stabilize before looking for new data. Once sufficient energy is built up in resonant cavity 318 the process is repeated for a single wavelength ring-down data at a given temperature. Ring-down spectra are processed by the data analysis system 316 . These various delays are illustrated in FIG. 5A .
As shown in FIG. 5A , at time t 0 , light source 302 is energized by providing operating current I, which is above the light source's threshold current I 0 , Threshold current I 0 varies based on the type of light source used. Delay time t 2 represents the delay to allow the light source to stabilize. In one exemplary embodiment, time delay t 2 is set to about 100 msec. Wait time t 3 represents the time to allow the current modulation to build up within resonant cavity 318 . It should be noted that the actual time required for the current modulation to build up within resonant cavity 318 is <<t3.
In an exemplary embodiment, wait time t 3 is based on the modulation frequency f of light source 302 , and is desirably equal to about 1/f. In another exemplary embodiment, t3 is equal to about 1/f plus the time needed to exceed the threshold level in the resonant cavity for a ring-down to occur. Time delay t 1 is based on the ring down time of resonant cavity 318 . In order to allow sufficient time for light energy to “ring down” in resonant cavity 318 , time delay t 1 is desirably set to about ten (10) times the ring down time of the cavity.
Laser temperature driver 416 , under control of convention means (not shown), provides temperature control for light source 302 for the generation of a desired light frequency at a given temperature. The frequency is selected based on the particular analyte of interest.
Various advantages are realized from the present invention, such as:
Allowing use of almost 100% of the beam power generated by light source 302 (there may be negligible albeit undetectable losses within optical fiber 304 and collimator 308 ). Higher intra-cavity energy build-up provides better signal to noise ratio and reduces shot noise. This is extremely beneficial when a light source is weak. As mentioned above, typically, only about 50˜80% of light power goes to the first order when light passes through an AOM. Cost savings are realized from eliminating the AOM. A typically commercially available AOM costs approximately $2,000. Simplified CW-CRDS setup—This allows more spatial flexibility for the setup arrangements, and eliminates the mechanical and optical sensitivity, introduced by the AOM, to the testing environment.
Although illustrated and described herein with reference to certain specific embodiments, the present invention is nevertheless not intended to be limited to the details shown. Rather, various modifications may be made in the details within the scope and range of equivalents of the claims and without departing from the spirit of the invention.
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An apparatus and method for controlling a light source used in Cavity Ring-Down Spectroscopy. The apparatus comprises a controller that generates a control signal to activate and deactivate the light source based on a comparison of an energy signal from a resonant cavity and a threshold. The light source is activated for a time period based on the stabilization time of the light source and the time necessary to provide sufficient energy to the resonant cavity. Thereafter the controller deactivates the light source for a predetermined time period by interrupting its current source so that the light energy in the cavity rings down and so that the presence of analyte can be measured. The light energy from the light source is directly coupled to the resonant cavity from the light source.
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BACKGROUND OF THE INVENTION
The present invention relates to a neon lamp, and particularly to a connection structure for use in neon lamps.
Neon lamps are useful indicating devices for various occasions and locations. The neon lamps may be twisted into various patterns and letters such as a Christmas tree, a star or a name etc. They have also been widely used in many public locations such as restaurants, disco centers, bars etc.
A neon lamp is powered by an electricity supply of 220 voltage by means of a transformer having a voltage of 6 KV-15 KV at its secondary side. Thus, the risk of electric shock is increased. Further, as one transformer may only be used in one neon lamp, the resulting effect is simple without variability.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a neon lamp assembly which prevents the users from receiving an electric shock.
Another object of the present invention is to provide a neon lamp assembly which is easy to be installed.
A further object of the present invention is to provide a neon lamp assembly which may be compatible with light fixtures which use a direct current (DC) voltage.
A further object of the present invention is to provide a neon lamp which is suitable to be installed at a location separate from a building such as a car or a garden.
A further object of the present invention is to provide a neon lamp assembly which may sequentially control the on/off of the neon lamps and produce a variable accent.
According to the present invention, a neon lamp assembly includes a DC power cord for supplying a DC power to the whole assembly, a neon lamp, a frequency/voltage conversion circuit for generating a high voltage to turn on the neon lamp, two metal lead-out pins for connecting the DC power cord with the frequency/voltage conversion circuit, and a housing for receiving the neon lamp, and the conversion circuit.
Other objects, advantages, and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective exploded view of the neon lamp assembly of the present invention;
FIG. 2 is a partially cross-sectional view showing a connection structure of the neon lamp assembly of FIG. 1;
FIG. 3 is a cross-sectional view of another embodiment of the connection structure of the neon lamp assembly in accordance with this invention;
FIG. 4 is a cross-sectional view of a further embodiment of the connection structure of the neon lamp assembly in accordance with this invention; and
FIG. 5 is a block diagram showing the interconnection between an AC power source and this invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, there is shown a perspective exploded view of a neon lamp assembly 10 in accordance with the present invention. As shown in the drawing, the neon lamp assembly 10 has a housing 11 sized to receive a neon lamp 12 and a frequency/voltage conversion circuit board 13, a support tube 14 for receiving a protruded portion 15 of the housing 11, and a pedestal 16 for receiving the tube 14. The neon lamp assembly 10 is further secured onto a ground surface by a stake 17. A cable 18 having two conductive wires is provided within the support tube 14 for electrically connecting to the conversion circuit board 13 which has two pins 20 for passing through sheaths of the cable 18 and achieving electrical connection therebetween. The support tube 14 has two notches 21, 22 on a wall thereof for the cable 18 to pass through. A knob 19 is engaged with a ratchet wheel (not shown) within the tube 14 for pushing the cable 18 onto the pins 20.
As shown in FIG. 2, the connection structure inside the support tube 14 is shown in a cross-sectional view. The knob 19 shown by dashed lines is engaged with a ratchet wheel 30 by a shaft 23. The ratchet wheel 30 has five teeth 31 for pushing the cable 18 onto the pins 20. When the user turns the knob 19 and one of the teeth is under the pins 20, the cable 18 is pushed onto the pins 20 such that the tips of the pins 20 may pass through the sheaths of the cable 18 and be in electrical contact with the conductor of the cable 18. When the user further turns the knob 19 it no longer urges the cable 18 against the pins 20, thus the neon lamp will be disconnected from the power supply.
FIG. 3 shows a clamp 40 having a base 41 and a cover 50 pivotally attached thereto. The base has a bottom surface, two walls, a longitudinal slot with a groove centrally defined in the slot. The cover 50 has a top surface, a bottom surface, a first sidewall and a second sidewall. A hinge plate extends from the first sidewall to link pivotally the cover with base. The cover is sized so that the bottom surface will be received in the cover 50. Two electrically conductive spikes are securely attached to the bottom surface of the cover, each aligning with one of the holes. A wire extends from each of the spikes through each hole and continues to the conversion circuit board 13. Two wires carrying an electric current are fittingly received in the groove. The cover can be swung towards the base so that the bottom surface is disposed in the slot and each spike penetrates a sheath of one of the wires carrying an electric current.
To disconnect the power supply from the neon lamp, a user exert a force against the bottom surface of the base thereby slightly deforming the clamp so that the snapping lock of the base is overcome and the cover exits the slot thereby breaking contact between the spikes and the current carrying wires. A feature of this clamp is that the second sidewall of the cover has a lip protruding therefrom so that when the cover is pressed into the slot, the lip provides a snapping lock.
FIG. 4 is perspective view of the connection structure of the neon lamp assembly. The pins 20 pass through the sheaths of the cable 18 and are in connection with the conductors of the cable 18.
Referring to FIG. 5, an indoor AC source 60 is used to provide the power needed by the whole system. An AC/DC adaptor 70 is connected to the AC source 60 for converting the AC power into a DC voltage for example 12 volts which may be applied to the location of garden with a cable 18 (in FIG. 1) without the risk of electric shock. A sequential circuit 80 is connected between the AC/DC adaptor 70 and a neon lamp assembly 10 for sequentially turning on the neon lamp thereby achieving an "alternating" image.
Although the invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed.
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A neon lamp assembly includes a neon lamp, a frequency/voltage conversion circuit board for powering the neon lamp, a housing for receiving the neon lamp and the circuit board, a cable for supplying a DC power for the circuit board, a plurality of pins provided between the cable and the circuit board for penetrating the sheaths of the cable and receiving power from the cable.
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TECHNICAL FIELD
The present invention relates to a surgical drill guide and a surgical plate that are attachable to each other for retaining a precise alignment therebetween. More particularly, the invention relates to a bone plate with a fastener hole and surgical drill guide with an expandable collet having a rim that, when contracted, is smaller than the fastener hole.
BACKGROUND OF THE INVENTION
Surgical fixation plates are used in many procedures to mend, align, and alter compression of patients' bones. These plates are primarily secured to the patient's bones by a plurality of fasteners such as screws. Proper orientation and alignment of fasteners and secure surgical fixation of the plates is crucial to avoiding future complications after implantation. This is especially the case for cervical spine locking-plates, such as sold by SYNTHES Spine. These plates are used for long term, intravertebral fixation, bone-fragment fixation, and anterior decompression in the cervical region of the spine. Locking plates enable secure monocortical implantation, meaning that their screws need only penetrate the anterior bone cortex. In conventional plates, screws must pass through both the anterior and posterior bone cortices to attain sufficient support. In passing through both cortices, conventional plates risk penetrating the spinal chord.
Surgeons implanting vertebral plates operate within a fine margin of error. Fairly little vertebral bone is available for setting fasteners. Each plate hole should coaxially align with its screw, i.e., each plate hole has an axis that must align with the screw axis. Otherwise, screws do not seat correctly with the plate. Thus, misalignments can potentially damage tissues, including the spinal cord, or lead to improperly secured plates.
Locking plates in particular demand precise fastener alignment. Cervical locking plates are generally about 2 mm thick. Some screw holes in these plates are inclined by 12° to the surface of the plate to permit optimal screw placement in the cervical region of the spine.
Anchor screws secure the locking plate to the vertebral body. Anchor screws have hollow, longitudinally slotted expansive heads that must fit snugly within a plate's screw hole. These screws are externally threaded to secure to the vertebral bone and the plate. These screws are also threaded internally from their head through a shallow portion of their shaft. Once a surgeon implants an anchor screw, he or she screws a small locking screw into the head of the anchor screw. This locking screw expands the head of the anchor screw so that the head presses outwardly against the locking plate's hole for a compression fit. This compression fit locks the screw in place and creates a solid coupling between the plate and the screw, preventing motion between them and preventing the screw from backing out from the plate, which may damage the esophagus.
This locking mechanism demands extremely precise screw alignment. If the holes drilled in the bone prior to anchor screw insertion are misaligned or off center, anchor screws and locking-plate holes will not seat correctly. Forcing a misaligned anchor screw into the plate hole can collapse the expansive head and prevent insertion of a locking screw. Thus, accurate drill guides for use in drilling the screw hole into the bone are critical to successful operations.
Known drill guides for locking plates, such as disclosed in a SYNTHES Spine catalog dated 1991, are generally a cylindrical tube shaped to receive and guide a drill bit. Most known guides also have a handle. A tip of the tube is shaped to slide into screw holes. A shoulder near the guide tip rests against a modest countersink in the screw hole to limit the guide's insertion into the hole. Constant axial pressure against the plate is required to maintain the guide in the hole, although it is sometimes beneficial to limit unnecessary pressure against the spine during drilling. Also, a clearance between the tip of the guide and the hole is provided to ease insertion into the hole. Due to this clearance, the diminutive thickness of the plate, and the small size of the countersink, an amount of angular play exists in this system. Other similar guides, though shown with femur fixation-plates, are disclosed in U.S. Pat. Nos. 2,494,229, and 5,417,367.
A more accurate drill guide is sold by SYNTHES Spine and shown in its catalog dated 1995, in which angular play is reduced and which does not require a constant force against the plate. This drill guide has an expanding collet formed with a plurality of fingers disposed coaxially about a drill guide sleeve. The sleeve is conical, and when it is slid forward, it spreads the collet fingers to lock them against the inside walls of a screw hole in a cervical spine locking plate. A scissoring handle linked to the collet and the sleeve controls the relative forward and backward motion therebetween.
At the forward tip of the drill guide, the collet has a neck, designed to press against the inside walls of the screw hole. Adjacent this neck is a radially extending rim, which, in a naturally assumed contracted position, has a diameter slightly larger than the screw hole, providing an interference fit. As a surgeon inserts the tip of the collet into the screw hole, the greater diameter of the rim provides a surgeon with a detectable snap and decreased resistance to insertion of the collet as the rim passes to the far side of the hole. To extract the collet from the screw hole, the surgeon must apply a slight force to pry the rim back through the smaller diameter walls of the hole, as these force the rim to contract to the smaller diameter.
A problem frequently arises when using this drill guide during surgery. Once the plate has been carefully positioned in the desired implantation position within the incision, when the surgeon attempts to remove the drill guide from the bone plate, the collet rim often catches on the plate. This catching prevents the drill from releasing the plate, and the surgeon often pulls the plate out of the incision along with the drill guide. As a result, any temporary fixation pins that were holding the plate to the bone could be stripped out of the vertebra, weakening the supporting bone structure, or in the best scenario, the plate would merely become misaligned with previously drilled holes. Even if the plate only becomes misaligned, however, careful realignment of the plate is required before the implantation procedure can continue.
Due to the precise nature of the relationship between the dimensions of screw hole and the rim and neck of the collet, the above problem cannot be avoided by simply using a particular drill guide in combination with any available plate that has larger screw holes. The drill guide and its corresponding locking plates are precisely size-matched and are sold in kits. A drill guide of this type cannot adequately lock and function as a guide with available plates with differently sized holes than those for which the guide was designed. Slightly large holes, for instance, permit excessive play between the plate and the guide, even when the guide is expanded.
Thus, a drill guide is needed that can disengageably lock to a surgical plate fastener hole, but without catching as the drill guide is extracted therefrom.
SUMMARY OF THE INVENTION
The invention is directed to instrumentation for fixing bones or bone fragments to each other. The instrumentation includes a bone plate for attaching to the bones, and a drill guide. The bone plate has at least one fastener hole through which fasteners, such as locking bone screws, fasten the plate to the bones. The hole has an inner wall with a predetermined hole diameter.
The drill guide has a guide member for guiding a drill bit. A hollow collet disposed coaxially with the guide member has a radially expandable forward end with a neck and outwardly projecting neck and an outwardly projecting rim forward of the neck. The neck is configured to press outwardly against an inner wall of the plate hole when collet is in the expanded position. The rim is freely extractable through the plate hole when the collet is in a contracted position. However, when the collet is in an expanded position, the rim does not fit through the plate hole.
To achieve this, the rim defines a contracted outer rim diameter smaller than the hole diameter when the rim is in a contracted position, rendering the rim freely extractable from the hole. When the rim is in an expanded position, it defines an expanded outer rim diameter larger than the hole diameter, rendering the rim impassable through the plate hole. The contracted rim diameter is preferably between 0.1 mm and 0.3 mm smaller than the hole diameter, or about 95% of the hole diameter. In the preferred embodiment, the rim protrudes radially from the neck by less than 0.1 mm. In one embodiment, the diameter of the rim is equal to that of the neck.
To further facilitate extraction of the rim from the hole, the rim has a rounded cross section in a plane extending through the axis of the neck and rim, preventing the rim from catching on the plate during its extraction therefrom. Also, a surface of the rim substantially adjacent the neck and configured at a first angle thereto of preferably less than about 55°, and more preferably of about 45°.
The guide member includes a guide sleeve movably axially and telescopically received within the collet. The sleeve defines a guide bore through which it axially receive and guide a drill bit. In a forward position within the collet, the sleeve biases the collet towards the expanded position. Preferably, the sleeve has a surface tapered inwardly at a second angle of between 3° and 5° to its axis to effect the expansion of the collet. More preferably this taper angle is about 4°.
As a result, the invention provides a surgical drill guide and a bone plate that are securable to one another, but which do not catch on each other upon drill guide extraction. The guide is unfetteredly and freely removable from the plate.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a side view of a surgical drill guide according to the invention;
FIG. 2 is a cross-section, cutaway view of an expandable collet in a contracted position and a guide sleeve according to the invention;
FIG. 3 is an enlarged cross-section of the collet being inserted into a locking plate;
FIG. 4 is a further enlarged view of the front of the collet;
FIG. 5 is a cross-section of a drill guide assembly of the invention locked coaxially to a screw hole and aligned at an angle to the surface of a locking plate;
FIG. 5A is an expanded cross-section of the forward portion of the drill guide assembly of FIG. 3 ;
FIG. 6 is a cross-section of a drill guide assembly according to the invention locked coaxially to a screw hole extending perpendicularly to the surface of the locking plate;
FIG. 6A is an expanded cross-section of the forward portion of the drill guide assembly of FIG. 4 ;
FIG. 7 is a flow chart of the method of implanting a cervical spine locking plate; and
FIG. 8 is a flow chart of the method for using the drill guide assembly to drill an aligned hole.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows an embodiment of a surgical drill guide assembly 8 according to the invention, which is adapted for use with a cervical spine locking plate. At a forward end of the drill guide assembly is a collet 10 . Telescopically and slideably engaged within collet 10 is a guide sleeve 12 . Preferably, a tissue protector 14 extends rearwardly from the sleeve 12 . The collet 10 , sleeve 12 , and tissue protector 14 are adapted to axially receive a drill bit 16 , and the guide sleeve 12 is sized to retain the spinning bit 16 in a precise coaxial alignment.
The collet 10 is fixed to a remote rear handle-member 18 . The handle member 18 is pivotably attached to a scissor grip 20 by a handle pin 22 . Together, handle member 18 and scissor grip 20 form a drill guide assembly handle 23 , which allows a user to maneuver and use the drill guide assembly. The scissor grip 20 has an arm 24 that extends to the opposite side of the handle pin 22 from the grip 20 to pivotably attach to an actuation bar 26 at actuation pin 28 . An end of the bar 26 is pivotably attached with the sleeve 12 at sleeve pin 30 .
Thus, the entire drill guide assembly in this embodiment forms a four bar linkage. When a surgeon squeezes scissor grip 20 towards handle member 18 , the arm 24 forces the actuation bar 26 forward. This in turn forces the sleeve 12 to slide forward, deeper into collet 10 . Preferably, however, no part of the sleeve 12 can slide further forward than the front of the collet 10 . The scissor grip 20 has a forward wall 32 and a rear wall 34 to help the surgeon manually force the sleeve 12 forward or backward by closing or opening the guide sleeve assembly with only one hand. Preferably, leaf springs 36 are fastened to the handle member 18 and the scissor grip 20 to further assist rearward motion of the sleeve 12 by biasing the handle 23 towards an open position.
The collet 10 has a forward end 40 that is radially expandable. In this embodiment, the collet has a plurality of fingers 38 that can be spread apart to expand the forward end 40 of the collet 10 .
Referring to FIG. 2 , the collet 10 coaxially receives the sleeve 12 about an axis 37 . Also, a guide bore 39 extends along axis 37 for guiding a drill bit coaxially therein.
The forward end 40 of collet 10 is preferably comprised of longitudinally extending fingers 38 . The fingers 38 are divided by slots 42 extending longitudinally between adjacent fingers 38 . These fingers 38 are resiliently biased inwardly and naturally assume an inward disposition when in a relaxed state and when the sleeve 12 is in the unlocked position, as shown in the figure. In the figure, a portion of the sleeve 12 has been cut away to better illustrate the slots 42 .
At a frontmost portion of the expandable forward end 40 of the collet 10 , the fingers 38 form a radially expandable circumferential neck 44 . At the back end of and adjacent to neck 44 is a shoulder 46 , and at the front end of and adjacent to neck 44 are protrusions that form a radially expandable rim 48 . These portions of the collet 10 , i.e., the neck 44 , the shoulder 46 , and the rim 44 , are preferably a single piece of material of unitary construction, in the interest of minimizing the size of the drill guide that must be inserted into an incision.
In the contracted, unlocked position shown in FIG. 2 , the neck 44 and the rim 48 are sized to fit freely through screw holes in a locking plate. FIG. 3 shows the collet 10 being inserted into a screw hole 64 in a locking plate 56 . In the drawing, the collet is in its natural, contracted position. The collet 10 is resiliently biased towards this position, in which the neck 44 has a contracted diameter d 1 and the rim has a contracted rim diameter d 2 . The screw hole 64 has an inner wall with a hole diameter d 3 .
The contracted rim diameter d 2 is smaller than the hole diameter d 3 to permit free and unfettered extraction of the rim 48 from the hole 64 . Preferably, the contracted rim diameter measures between 0.1 mm and 0.3 mm less than the hole diameter d 3 . More preferably, the rim diameter d 2 is 0.2 mm smaller than the hole. The contracted rim diameter d 2 is preferably between 4.2 mm and 4.4 mm in a drill guide that functions with a hole diameter d 3 of about 4.5 mm. Thus, the contracted rim diameter is approximately 95% the size of the hole diameter. Also, the contracted rim diameter d 2 is preferably about between 1 mm and 2 mm larger than the contracted neck diameter d 1 . Thus, the rim 48 protrudes from the neck 44 by a preferred 1 mm. Hence, the contracted neck diameter d 1 is preferably more than 95% as large as the contracted rim diameter d 2 .
These diameters permit a surgeon to extract, and most preferably also insert, the rim 48 of the collet 10 through a screw hole 64 without the rim 48 catching in the far side 57 of the plate 56 when the collet 10 is contracted. This arrangement virtually eliminates the possibility of collet 10 failing to disengage from a bone plate 56 , reducing the likelihood of unintentional extraction of temporary fixation pins or misalignment of a previously positioned plate 56 .
At the same time, having a rim 48 , provides the surgeon with a detectable feel for when the rim has completely passed the through the hole 64 . In alternative embodiments, the rim 48 may be eliminated completely, for instance by reducing the contracted rim diameter d 2 to an equal size as the contracted neck diameter d 1 . These embodiments, though, would lack the signal to the surgeon produced by full passage of the rim 48 through the hole 64 .
As shown in FIG. 4 , to further foment free removal of the rim 48 from the hole 64 , the rim 48 is rounded in a cross-section taken parallel to axis 37 . The cross section preferably curves around a radius 49 of about 0.15 mm. Also, in this embodiment, a surface of the rim 48 disposed adjacent the neck 44 is configured at an angle 51 of less than 55° to the neck 44 , and most preferably at about 45° thereto. In some embodiments, this angled surface is preferably joined to the neck 44 via a narrow surface 47 of concave radius.
Referring again to FIG. 3 , shoulder 46 has a diameter d 4 that is greater than the contracted rim diameter d 2 . Thus, the shoulder 46 has a diameter that is greater than the hole diameter d 3 such that the shoulder 46 cannot be inserted therethrough. Still further, in the preferred embodiment, the neck 44 is slightly longer than the thickness of the hole wall 65 , such that the neck can abut the wall of the locking plate hole and the rim 48 can abut the inside surface of a locking plate 56 . In this manner, the drill guide assembly can be secured to the locking plate 56 , restricting relative movement.
The inside of the expandable forward end 40 the collet 10 preferably has a variable inner diameter. Preferably, the fingers 38 have a step 50 or a taper, resulting in a smaller inner collet 10 diameter forward of the step 50 .
The guide sleeve 12 includes a forward portion 52 that cooperates with the fingers 38 to expand the fingers 38 when the guide sleeve 12 is moved into a locked position. Preferably, the guide sleeve 12 is tapered at taper angle 53 to the axis 37 to form a conical forward portion 52 . The conical section 52 of guide sleeve 12 pushes outwardly against the inner surface of the collet 10 as the guide sleeve 12 is moved forward to expand the forward end 40 . In this embodiment, the conical section mates with and pushes against the inner collet 10 surface forward of step 50 to push the fingers 38 radially outward. When the guide sleeve 12 is in the unlocked position as shown in FIG. 2 , the conical section 52 allows the fingers 38 to return to a relaxed, contracted position. This allows the collet 10 to be inserted and retracted from the plate hole. The taper angle 53 is preferably between 3° and 5°, and more preferably about 4°. The inner surface of the collet 10 forward of the step 50 is also preferably tapered at an angle 55 to axis 37 that is substantially equal to taper angle 53 . This range of angles provides a desirable amount of movement of the sleeve 12 within the collet 10 to bias the collet 10 from a contracted position to an expanded position.
When the surgeon squeezes the handle 23 , the guide sleeve 12 is moved forward and the conical section 52 cooperatively forces the inner surface of the collet 10 beyond step 50 and fingers 38 radially outward. Thus, the forward motion of the guide sleeve 12 towards a forward position expands the forward end 40 of the collet 10 to an expanded position. In this manner, the neck 44 can be expanded to abut the inner wall of the plate screw hole and the rim 48 is expanded to abut the inner surface of the locking plate. In the expanded position, the expanded outer diameter d 5 of the rim 48 is greater than the plate hole diameter d 3 so that the guide cannot be retracted from the plate hole, as shown in FIG. 6 A.
FIGS. 5-6A show the sleeve 12 in a locked, forward position, and the expandable end 40 in an expanded position and locked to different screw holes of the same predetermined diameter d 3 . Referring to FIGS. 5 and 5A , screw hole 54 in locking plate 56 is disposed at an angle of about 12° to the locking plate's 56 outside surface 58 . The drill guide assembly is configured so that when the collet 10 is expanded, as shown, the neck 44 presses outwardly against interior wall 60 of screw hole 54 , positively gripping the wall 60 . The rim 48 preferably abuts the back surface of the plate 56 so that the neck positions the guide. The shoulder 46 , on the other hand, preferably does not abut the outside surface 58 of the plate 56 . A firm locking against the plate 56 results, and precise co-axial alignment through the center of screw hole 54 is achieved even though the surface area of wall 60 is small. In this embodiment, the axis of the drill guide is aligned with the axis of the plate screw hole 54 . Thus, the axis of the hole drilled into the bone will also be aligned with the axis of the plate screw hole 54 . In this manner, an anchoring screw inserted into the drilled hole will be centered and aligned with the plate screw hole 54 , i.e., they too will be substantially co-axially aligned.
The plate 56 and the guide may become slippery during use when blood and drilled tissue residue cover the instruments. In this situation, rim 48 aids in preventing the collet 10 from sliding backwards, out of the hole 54 . The rim 48 is adapted to rest against the far side of the plate 56 , near the perimeter of the hole 54 . Note that when the drill guide of this embodiment is locked to an angled hole 54 , as shown, only a segment of rim 48 may actually contact the back of the plate 56 . This small contact surface suffices to retain the collet 10 within the hole 54 .
Preferably, a gap 62 remains between the forwardly facing surface of shoulder 46 and the plate 56 . This is because, in the preferred embodiment, the shoulder 46 is not necessary for achieving a proper drill alignment or a secure locking. Consequentially, a surgeon need not press the drill guide against the locking plate 56 to keep the guide properly seated within the hole 54 .
FIGS. 6 and 6A show the same embodiment of the invention locked to a screw hole 64 in a different part of locking plate 56 . Hole 64 is perpendicular to the locking plate's 56 surface 66 . In this application, most of the rim 48 is in contact with the back of plate 56 . Similarly to the applications shown in FIGS. 5 and 5A , a gap 62 preferably remains between the forwardly facing surface of shoulder 46 and the plate 56 .
As seen in FIGS. 5 and 6 , the internal diameter of the tissue protector 14 is preferably wider than that of the sleeve 12 , forming a step 68 . This step 68 may alternatively be formed in a different place along the length of the tissue protector 14 or the sleeve 12 . Step 68 is adapted to stop a surgical drill bit 16 that is inserted through the rearward end of the tissue protector from advancing beyond a predetermined depth. This stopping action occurs when the step 68 contacts a portion 70 of the drill 16 that is wider than the internal diameter of the sleeve 12 or the tissue protector 14 forward of the step 68 , as illustrated in FIG. 6 .
Referring again to FIG. 1 , the drill bit 16 illustrated has a safety stop 72 with a wider diameter than the interior of the tissue protector 14 . The rear 72 of the tissue protector 14 also preferably prevents advancement of the drill bit 16 when the tissue-protector rear 74 contacts the bit's 16 safety stop 72 . By selecting a bit 16 with an appropriately located safety stop 72 or safety step 68 , the surgeon is assured that the bit 16 will penetrate the vertebral body no further than necessary for insertion of a screw.
The flow chart in FIG. 7 provides the procedure for implanting a cervical spine locking plate. After making an incision, and measuring the cervical vertebra to be fixed with the plate, a surgeon places a cervical locking plate of a correct estimated length on the vertebral body. The surgeon then bends the plate to contour it to the correct lordotic curvature. Once the plate is properly positioned on the vertebra, it is secured with a temporary fixation pin, which is monitored under lateral imaging. The surgeon then locks the drill guide to the plate and drills into the bone. He or she then taps the hole, inserts an anchor screw, and inserts a locking screw to lock the anchor screw to the plate. The locking and drilling process is repeated for the remaining screws. The last hole is drilled through the plate hole in which the locking pin was located. Finally, the surgeon closes the wound.
The chart in FIG. 8 shows the procedure for using the drill guide. A surgeon inserts the collet into the plate screw hole and squeezes the handle to slide the sleeve forward, expanding the collet with the conical portion of the sleeve and locking the drill guide to the plate. The surgeon then inserts the drill through the drill guide sleeve, drills the hole, and removes the drill. He or she opens the handle of the drill guide, sliding the sleeve backwards and releasing the collet from the hole, and then freely and unfetteredly removes the guide from the plate.
Before and during locking-plate implantation, the surgeon may insert the expandable end 40 of the collet 10 into a screw hole in a locking plate 56 . By squeezing the handle 23 , the surgeon may grasp and manipulate the plate 56 without an additional plate holder if he or she so desires.
Preferably, friction between the forwardly moved conical portion 52 and the inner surface of fingers 38 beyond step 50 retains the expandable end 40 of the collet 10 in an expanded, locked position. This provides a presently preferred travel of scissor grip 20 required to expand and contract the collet 10 . In this embodiment, the inward bias of fingers 38 is selected to produce the desired friction, while allowing operation of the handle 23 with only one hand. Alternative taper angles of conical portion 52 and inner finger 38 surfaces, and alternative finger 38 resiliencies may be chosen according to the purposes of other embodiments.
The tissue protector 14 is preferably sized so that once the plate 56 is properly positioned over the implantation site and the collet 10 is locked to the plate, the tissue protector 14 extends to the outside of the patient's body. As a result, a spinning bit 16 will not laterally reach or harm surrounding tissues that the surgeon does not intend to drill.
Also, the handle 23 is preferably located remotely from the drilling site. This frees space near the plate 56 and permits insertion of the drill guide into narrow incisions.
Various changes to the above description are possible without departing from the scope of the invention. For example, in embodiments for use with plates that have noncircular screw holes, the outer cross-section of collet 10 may match the shape of the holes. It is intended that the following claims cover all modifications and embodiments that fall within the true spirit and scope of the present invention.
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Instrumentation for osteofixation including a locking bone plate and a surgical drill guide. The plate has a plurality of fastener holes with inner walls of a preselected hole diameter. The drill guide has a guide member, for guiding a drill bit, and a hollow collet disposed substantially coaxially with the guide member. A radially expandable forward end of the collet comprises a radially expandable neck and an outwardly projecting rim disposed forward of the neck. This rim defines a contracted outer rim diameter that is smaller than the hole diameter in a contracted collet position, and an expanded outer rim diameter that is larger than the hole diameter in an expanded position. Thus, the rim is freely extractable through the plate hole in the contracted position, but is unreceivable through the plate hole in the expanded position. The collet neck is configured and dimensioned to press outwardly against an inner wall of the plate hole when the neck is expanded.
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BACKGROUND OF THE INVENTION
This invention relates to a method and composition for preventing the fouling of submerged objects or marine structures while also minimizing pollution, and more particularly to a method and composition for preventing fouling of marine structures for an extended period of time by using organotin compounds which are chemically bonded to synthetic polymers.
From the beginning of man's attempt to use water to travel, he has been plagued with the problem resulting from the fouling of ships, buoys, pilings, and other types of marine structures, by organisms present in the water. It has been found that microorganisms, their viscous bio-organic product and absorbed organic matter, constitute a tenacious, opaque slime which forms on these submerged surfaces. The initial organisms in this fouling sequence are bacteria followed by a biotic progression of diatoms, hydrids, algae, bryozoans, protozoans, and finally macrofoulants Macrofoulants tend to be rugophilic, settling on roughened surfaces in preference to smooth surfaces. It is thought that primary marine slimes precondition the submerged surface in some manner stimulating the settling of macrofoulants. This theory is supported by the fact that barnacle settlement is less frequent on clean glass surfaces compared to those covered with emollient films high in particulate matter. This film may provide a physical substrate and/or a nutritive source which encourages the attachment of macroscopic plants and animals.
The resultant effect of the concentration of these plants and animals settling and attaching themselves to ships is that they contribute significantly to speed reduction, they increase fuel consumption, and in the area of concern over water craft detection, they strengthen the noise signature of vessels under way thereby rendering covert activity more difficult.
The problem of fouling applies not only to vessels but also to other marine structures. For example, fouling of sonar domes has been found to seriously limit the active and passive modes of operation of ships' acoustical systems. Fouling of moored data systems and ship-and-shore facilities by marine organisms impedes operations and necessitates a large maintenance allocation. Buoys can shift due to the excessive weight of fouling organisms. Wood pilings in berthing facilities undergo structural weakening and ultimate destruction due to marine borer and fungal attack. The fouling of piping including steel piping and bronze couplings and fittings in the sea-water intake piping systems of ship-and-shore facilities leads to reduced flow rates, valve seat damage, and accelerated metal corrosion. Concrete or ferro-cement or other similar structures are also adversely affected by fouling organisms.
It is only since the beginning of this century that improvements have been made in the early Phoenician methods of using copper cladding and poisonous paints to prevent fouling. One such improvement involved the use of asphalt as an antifouling coating. Another improvement involved the use of coatings containing copper salts or oxides. In addition, organometallic salts, e.g., tri-n-butyltin oxide (TBTO), tri-n-butyltin fluoride (TBFT), tri-n-butyltin sulfide (TBTS), being extremely powerful biocides and toxic to a wide range of marine organisms, have been used as the active ingredients in a variety of antifouling coatings. Investigations into the use of organotin compounds for use in antifouling paints have received much attention because coatings containing these compounds exhibit excellent pigment retention, but do not accelerate the corrosion of metal substrates. However, these and other state-of-the-art compositions possess several drawbacks which limit their use as effective antifoulants. Asphalt lacks the desired durability to make it an effective answer to the problems posed. Other existing antifouling coating systems involve the use of paints which typically contain sufficient water soluble pigments, metal salts and inert fillers for direct contact to occur between the particles within the paint film; as one particle dissolves, another in contact with it is exposed to solvolysis. This process, called leaching, is uncontrolled and varies with such factors as coating age, water velocity, temperature and salinity, and the primary slime layer. Quantitative information indicates that in most cases the leaching rate of antifouling paints is excessive and poses a potential environmental hazard. As a result, the best available antifouling coatings are inefficient and short lived because of the above mentioned leaching process. This inefficiency leads to the concentration of the antifouling agent in the water in quantities well above normal oceanic background.
Although concern over avoiding a potential pollution hazard was not a motivating factor, attempts have been made in the past to incorporate the toxic substance in a polymeric antifouling coating composition by chemically bonding the toxic ingredient to the polymer. For example, see Leebrick, U.S. Pat. No. 3,167,473, or Goto et al, U.S. Pat. No. 3,684,752. However, this type of antifouling compositions has not proved to be commercially successful, apparently because of the inability of the resulting coatings to maintain their integrity over an extended period of time.
Thus, after approximately 12 to 20 months, or 50,000 miles transit the presently available antifouling paint systems begin to foul which, is indicative of the depletion of most of the antifouling agent from the coating into the marine environment, or of a complete breakdown of the coating itself. This short performance time is far less than the life time of five years or more desired of an antifouling coating.
The leaching rate of metallic salts and organometallic salts from presently used antifouling coating systems is governed by the relative proportions and solubilities of three components: rosin, antifouling agent and pigment. Rosins are resinous organic acids which have a water solubility of 100 mg/cm 2 /day. In addition to a relatively high solubility, rosins are consumed by sliming marine bacteria. This results in an accelerated biodegradable action, thus adding to the breakdown of the coating and subsequent accelerated release of metallic and oganometallic salts. At present the primary antifouling agent used by the United States Navy are cuprous oxide which has a water solubility of 0.5 mg/l and tributyltinfluoride which has a water solublity of 2.9 mg/l. Leaching of inorganic and organometallic antifouling salts from coating formulations could possibly be reduced by using their less water-soluble homologs in conjunction with insoluble pigments and as little rosin as possible. However, state-of-the-art antifouling technology has not provided an effective antifouling composition having a controlled leaching rate which minimizes the presence of toxic antifouling agents in the marine environment. Hence, it would be desirable to provide a new class of effective antifouling compositions having low leaching rates as compared to hitherto available compositions.
SUMMARY OF THE INVENTION
Accordingly, it is an object of this invention to provide a composition and method for the protection of marine structures from fouling organisms.
It is also an object of this invention to provide a composition and method for the protection of marine structures from fouling organisms for an extended period of time.
It is a further object of this invention to provide a composition and method for preventing the formation of a primary slime layer on marine structures.
Another object of this invention is to provide a composition and method for the preventing of fouling of marine structures while avoiding a potential environmental hazard.
It is also an object of this invention to provide an antifouling composition characterized by a low leaching rate of the antifouling agent from the composition.
These and other objects of this invention are met by providing a composition which comprises an organotin containing polymer wherein the organotin moiety is chemically bonded either directly to the polymer backbone or through a curing agent for the polymer, and a method of using said composition which involves forming, coating or impregnating a marine structure with said composition.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention provides a novel polymeric material possessing a low leaching rate, which is nonpolluting, and has excellent biocidal properties, and which upon application to the surface of, or incorporation in, a marine structure results in a structure which is free of fouling organisms but does not contribute to pollution. This result is obtainable due to the fact that the biocidal quality of the antifouling agent protects the surface of the structure but is not detrimental to the animal or vegetable life immediately surrounding the protected structure because of the low leaching rate of the antifouling agent from the polymer.
This new generation of biocidal polymers consists of low leaching, antisliming, organometallic polymers suitable as protective coatings for ship bottoms and other submerged surfaces, wherein in the backbone polymer is a vinyl resin such as a polyacrylate or a poly (methyl vinyl ether/maleic acid); an alkyd resin, or an epoxy resin; and chemically incorporated in the polymer is a R 3 Sn-group such as tributyltin, tripropyltin, triphenyltin; or tribenzyltin. These polymers may be used in any number of suitable forms including (1) low leaching organometallic polymeric films suitable for use as coatings or in reinforced or self-supporting structures; (2) low leaching organometallic polymeric syrups of the above described organometallic polymers applicable for the impregnation of structural woods in order to preserve these structures against bacteria, fungi and marine foulant attack; and (3) low leaching, granulated, organometallic polymers to be used for incorporation into ferro-cement, and other marine and fresh water concrete structures, thus producing a homogeneous nonfouling ferrocement and/or concrete structural composite.
It is estimated that these materials will extend the longevity of antifouling systems to at least 5 years. In addition, transparent, nonwettable, slimicidal films of the organometallic polymers can be used on underwater optical devices.
Because the antifouling compositions in general use today do not provide a satisfactory means of controlling the leaching rate of toxic coating components into the marine environment, the idea of chemically binding biocidal organometallic compounds on polymer backbones was conceived of as a solution to the problem. The resultant materials, organometallic polymers, are surface hydrolyzed in sea water to trigger their antifouling efectiveness. Laboratory studies show that the chemically bound organometallic moieties are released at a rate that is dependent on the nature of the organometallic polymer. As part of an effort to develop antifouling coatings having the lowest possible controlled leaching rates, various organometallic polymers were synthesized for the purpose of determining the rate of release of organometallic moieties from these polymers as well as their antifouling effectiveness. Factors influencing the rate of hydrolysis of the organometallic polymer, include polymer type, the degree of cross-linking within the polymer backbone and the degree of substitution by organometallic groups along the polymer backbone. Environmental conditions such as sea-water temperature, salinity, oxygen content, hydrogen ion concentration, and turbulence also influence the hydrolysis rate. Due to water hydrolysis, these organometallic ions are released from the polymer backbone at a controlled rate which is at least one order of magnitude less than state-of-the-art antifouling coatings. As a result, this chemical conservation of the biocidal organometallic agents will provide longer-term antifouling protection for marine structures, while reducing the potential pollution hazard attributed to presently used antifouling coatings by a factor of at least 10.
Any suitable method may be used to incorporate the organotin moiety into the polymer. For example, the incorporation can be accomplished by using an esterification reaction between an organotin oxide or hydroxide and a free carboxylic acid group present in the polymer. The organo-groups substituted on the tin may be the same or different and are selected from the group consisting of propyl, butyl, benzyl, and phenyl. Other groups do not appear to give the required long life antifouling capabilities. While it is not desired to be limited to any particular theory, it is believed that the chemical bond between the antifouling agent and the polymer prevents excessive leaching of the toxic agent from the composition. Because excessive leaching does not take place, there is no excess biocide in the water. Hence, there is no killing of plant and animal life in the water surrounding the protected structure by the antifouling composition. The low leaching rate also extends the life of the antifouling composition.
The reaction between the carboxylic acid group and the organotin oxide or hydroxide can be carried out in a number of ways. A monomeric acid may be esterified with a suitable tin compound and polymerized alone or in combination, with other monomers which may or may not contain organotin moieties. Alternatively, the tin compound may be reacted with free carboxylic acid groups on the polymer backbone. Also, the organotin compound can be chemically combined with a crosslinking or curing agent and used to crosslink or cure a polymer, especially a thermosetting polymer. Any other suitable method can also be used to chemically incorporate the organotin compound into the polymer provided the tin compound is chemically bonded to the polymer. It is the chemical bond which gives the improved durability, and low leaching characteristics to the polymer.
Of the particular organotin groups, the tributyl-or tripropyltin groups are the most effective because they possess greater toxicity.
The tributyltin oxide or hydroxide can also be chemically reacted with a polymer which is chemically bonded to other tin compounds. When a tributyl or tripropyltin containing compound in conjunction with another organotin containing compound is incorporated in a polymer, the result is an antifouling composition more durable than the second organotin containing compound acting alone. Also, various tin-containing polymers can be mixed in any proportion in order to achieve desired antifouling properties. Furthermore, a single polymer may contain more than one type of organotin compound. Mixtures of organotin compounds on a polymer or mixtures of organotin containing polymers are effective against a broader spectrum of fouling agents.
The tin compound, used in accordance with the present invention, has the following structural formula: ##STR1## wherein R 1 , R 2 , and R 3 are selected from a group consisting of butyl, propyl, phenyl and benzyl. R 1 , R 2 and R 3 can be the same or different.
Suitable polymers to which the organic tin compounds may be chemically bonded are thermoplastic polymers such as vinyl polymers and thermosetting polymers such as polyester resins and epoxy polymers. Vinyl polymers include homopolymers and copolymers of acrylic and methacrylic acid monomers. The organotin containing polymers can be formed by polymerizing organotin oxide or hydroxide -- acrylic acid esters alone or in combination with monomers which may or may not contain an organotin moiety. Monomers suitable for forming the acrylic polymers are acrylic acid and methacrylic acid. To incorporate the organotin compound in the acrylic polymer, the acid group are usually esterified with the organotin compounds subsequent to polymerization of the acid monomers.
Another suitable vinyl polymer is a copolymer of methyl vinyl ether and maleic acid. Incorporation of the organotin compound is achieved by esterification of the acid group.
The development of organometallic polyesters and organometallic epoxies as effective antifouling materials has also been accomplished. Unsaturated alkyd resins prepared from the condensation reaction of polyhydric alcohols such as glycols and other polyols and polybasic acids such as adipic, sebacic, phthalic and maleic acid are cured with tributyltin methacrylate in a 1:1 molar ratio using an initiator to produce organometallic polyesters. Styrene in varying proportions may also be added to the monomer mixture prior to curing. These organometallic polyesters can either be dissolved in a solvent with or without additives such as pigments, thixotropic agents, or anti-settling agents, to produce an antifouling coating, or used by themselves in antifouling applications, i.e., antifouling gel coats. Furthermore, incorporation of glass fibers into this resin could produce a glass reinforced laminate with antifouling capability. In addition to incorporating the organotin moiety by curing an unsaturated resin with tributyltin methacrylate or other organometallic unsaturated monomers, the organotin group can be chemically incorporated on the resin backbone by esterification of some of the free carboxyl groups present where polybasic acids have been used in the resin formulation.
The concept of producing an antifouling structural plastic by curing with an organometallic agent can also be applied to epoxy resins. Unsaturated acids such as acrylic acids are known curing agents for glycidyl ether epoxy resins. When an organic acid is employed to cure an epoxy resin in an hydroxyl-free medium, the initial reaction involves the carboxyl group, followed by the reaction of the epoxy with the formed hydroxyl. The double bond of an unsaturated acid during this reaction remains inactive, and may be used to incorporate the organometallic reagent on the curing agent. It is known that tributyltrin methacrylate can be copolymerized with methacrylic acid. Therefore, a low melecular weight copolymer of tributyltin methacrylate and methacrylic acid can be utilized as an organometallic curing agent for epoxy resins. Modifications of the structures of amines, polyamines, polycarboxylic acids, and like compounds presently used as epoxide curing agents by incorporation of a tributyltin carboxylate group, e.g., H 2 NCH 2 CO 2 SnR 3 and R 3 SnO 2 CCH(CO 2 H) 2 where R is an organic radical can be prepared to function as new curing agents serving as carriers for the biocidal organotin moiety.
The effectiveness of the organotin containing polymer as to both antifouling capabilities and durability depends on the amount of organotin present. Molecular weight of the polymer does not appear to have an effect on these properties. However, polymers having a 6000-7000 molecular weight range are more conviently used.
The organotin containing component is operable in any range. However, a polymer containing at least 20% of the organotin component is most effective. For example, if organotin methacrylate and methyl methacrylate are polymerized together, there should be at least one unit of organotin methacrylate for every four units of methyl methacrylate. With regard to the amount of polymer present, a coating consisting essentially of an organotin polymer has been tested and the following conclusions drawn. While any reasonable coating thickness is feasible, coatings up to 1/8-inch thick are most useful. Coatings in the neighborhood of 20 mils thickness are also useful. Thickness may vary with amount of tin in the polymer and the length of time for which protection is desired.
The following examples are presented to illustrate the invention without unduly limiting the invention. All parts and percentages are by weight of the composition unless otherwise specified.
EXAMPLE I
The following procedures illustrate the preparation of a variety of vinyl polymers suitable for use as antifouling materials.
P1, POLY-TRI-n-BUTYLTIN-ACRYLATE
The reaction was carried out in a 1-liter, 3-necked flask, provided with an azeotropic distillation head connected to a reflux condenser, a thermometer positioned such that it read the temperature of the reaction solution, and a stopper. The reaction solution was stirred by means of a magnetic stirrer. In the reaction flask, polyacrylic acid (24 grams, 0.333 mole) was added to a solution of tri-n-butyltin oxide (84.8 ml, 0.167 mole) and dichloromethane (250 ml). The reaction was refluxed for 2 hours, at the end of which 3 ml of water was formed and collected by azeotropic distillation. The resultant clear organometallic polymer was cast in a film from the dichloromethane solution.
Analysis calculated on atomic absorption spectroscopy for P1: Sn, 33%. Found: Sn, 32.68%.
P2, POLY-TRI-n-PROPYLYTIN-ACRYLATE
P2 was prepared similar to P1 except that tri-n-propyltin oxide (68.2 ml, 0.167 mole) was the organometallic and benzene was the solvent. Three ml of water were formed by this reaction. The product polymer was again clear and was cast as a film from the benzene solution.
Analysis calculated for P2: Sn, 37%. Found: Sn, 36.52%.
P4, POLY (TRI-n-BUTYLTIN-ACRYLATE/TRI-n-PROPYLTIN-ACRYLATE)
P4 was synthesized by the general method described above. In this synthesis, equimolar quantities of tri-n-butyltin oxide (42.2 ml, 0.083 mole) and tri-n-propyltin oxide (33.9 ml, 0.083 mole) were reacted with polyacrylic acid in benzene to give a polymer with alternating organometallic groups. After 3 hours of refluxing, 3 ml of water were collected azeotropically. This clear polymer was cast as a film from the benzene solution.
P13, POLY-TRI-n-BUTYLTIN-METHACRYLATE
P13 was prepared in the usual manner from the reaction of crosslinked polymethacrylic acid (28.8 grams, 0.167 mole) and tri-n-butyltin oxide (42.2 ml, 0.083 mole) in toluene (300 ml). After the reaction had run for 3 hours, 16.2 ml of water were formed. The reaction mixture was filtered, and the isolated white powdery product was then washed with toluene.
Analysis calculated for P13: Sn, 32%. Found: Sn, 27.77%.
P16, POLY-TRIMETHYLTIN-ACRYLATE
P16 was prepared as poly-tri-n-butyltin-acrylate except that the organometallic was trimethyltin hydroxide (60 grams, 0.333 mole) and the solvent was benzene (300 ml). The reaction was terminated at the end of 21/2 hours. Five ml of water were produced by this synthesis. The white powdery product was isolated by filtering and washing the reaction mixture with benzene.
Analysis calculated for P16: Sn, 51%. Found: Sn, 28.24%.
P17, POLY-TRIMETHYLTIN-METHACRYLATE
P17 was synthesized as described above by the reaction of crosslinked polymethacrylic acid (28.8 grams, 0.167 mole) and trimethyltin hydroxide (30 grams, 0.167 mole) in toluene (300 ml). After 19 hours the reaction was terminated and 16.1 ml of water were collected. The reaction mixture was filtered and washed with toluene. The resulting polymer product consisted of a cream-colored, granular material.
Analysis calculated for P17: Sn, 48%. Found: Sn, 8.74%.
P24, POLY-TRIBENZYLTIN-ACRYLATE
P24 was synthesized similar to P1 except that tribenzyltin hydroxide (68.19 grams, 0.167 mole) was the organometallic and benzene (300 ml) was the solvent. After running the reaction for 2 hours, 2.5 ml of water were formed. After the solvent evaporated, a clear product polymer remained which was in the form of a film.
Analysis calculated for P24: Sn, 26%. Found: Sn, 23,31%.
P28, POLY-TRIPHENYLTIN-ACRYLATE
P28 was made as P1 was where triphenyltin hydroxide (100.2 grams, 0.273 mole) was reacted with an equimolar quantity of polyacrylic acid (19.65 grams, 0.273 mole) in benzene (400 ml). The reaction ran for 2 hours, at the end of which 4.9 ml of water had been collected azeotropically. P28 was isolated as a cream-colored powder.
Analysis calculated for P28: Sn, 29%. Found: Sn, 31.34%.
P29, POLY-TRI-n-BUTYLTIN-METHACRYLATE
P29 was the reaction product of polymethacrylic acid (28.7 grams, 0.334 mole) and tri-n-butyltin oxide (84.4 ml, 0.167 mole). The reaction was run in benzene (300 ml) for 3 hours, and 4 ml of water were collected azeotropically. P29 was a clear polymer and formed a film when the solvent was evaporated.
Analysis calculated for P29: Sn, 33% Found: Sn, 28.22%.
P31, POLY-TRI-n-PROPYLTIN-METHACRYLATE
P31 was prepared from the reaction of crosslinked polymethacrylic acid (28.8 grams, 0.167 mole) and tri-n-propyltin oxide (33.9 ml, 0.084 mole) in toluene (200 ml). After 3 hours of refluxing, 16.0 ml of water were formed. This high density polymer was a white powder.
Analysis calculated for P31: Sn, 36%. Found: Sn, 31.71%.
P34, POLY-TRI-n-PROPYLTIN-METHACRYLATE
P34 was the product polymer produced by the reaction of polymethacrylic acid (28.7 grams, 0.334 mole) and tri-n-propyltin oxide (67.8 ml, 0.167 mole) in benzene (300 ml). After 41/2 hours, 5 ml of water were formed and removed by azeotropic distillation. P34 was a clear product and was cast as a film from a benzene solution.
Analysis calculated for P34: Sn, 36%. Found: Sn, 34.19%.
P36, TRI-n-BUTYLTIN ESTER OF POLY(METHYL VINYL ETHER/MALEIC ACID)
The preparation of P36 was carried out in a 1-liter, 3-necked flask provided with a mechanical stirrer, an azeotropic distillation head connected to a reflux condenser, and a thermometer positioned such that it read the temperature of the reaction solution. The poly(methyl vinyl ether/maleic acid) (29.0 grams, 0.167 mole) was added to the reaction flask, which already contained benzene (300 ml) and tri-n-butyltin oxide (84.4 ml, 0.167 mole). At the end of 3 hours, 6 ml of water were collected azeotropically. P36 was a yellow transparent product which could be cast as a film from the benzene solution.
Analysis calculated for P36: Sn, 32%. Found: Sn, 30.80%.
P37, TRI-n-BUTYLTIN ESTER OF POLY(METHYL VINYL ESTHER/MALEIC ACID)
P37 was prepared as P36 was, except a higher molecular weight poly(methyl vinyl ether/maleic acid) was used. During this reaction, 6.1 ml of water were collected azeotropically. The resultant product was clear and could be cast as a film from the benzene solution.
Analysis calculated for P37: Sn, 32%. Found: Sn, 30.55%.
P38, TRI-n-PROPYLTIN ESTER OF POLY(METHYL VINYL ETHER/MALEIC ACID)
P38 was synthesized similar to P36. The low molecular weight poly(methyl vinyl ether/maleic acid) (29.0 grams, 0.167 mole) was reacted with tri-n-propyltin oxide (67.8 ml, 0.167 mole). From this azeotropic distillation, 6.9 ml of water were collected. P38 was a yellow, transparent polymer which could be cast as a film from the benzene solution.
Analysis calculated for P38: Sn, 36%. Found: Sn, 34.86%.
P39, TRI-n-PROPYLTIN ESTER OF POLY(METHYL VINYL ETHER/MALEIC ACID)
The synthesis of P39 was similar to that of P36, although the higher molecular weight poly(methyl vinyl ether/maleic acid) (29.0 grams, 0.167 mole) and the tri-n-propyltin oxide (67.8 ml, 0.167 mole) were used. From this reaction, 6.1 ml of water were collected azeotropicaly. P39 was isolated as a clear product which could be cast as a film from benzene solution.
Analysis calculated for p39: Sn, 36%. Found: Sn, 32.68%.
Several of the organometallic polymers were polymerized from their prepared monomers, instead of attaching an organometallic moiety to the polymer backbone. The preparation of P30, poly(tri-n-butyltin methacrylate/methyl methacrylate) characterizes the polymerization of organometallic monomers.
P30, POLY(TRI-n-BUTYLTIN METHACRYLATE/METHYL METHACRYLATE)
The monomers of P30 were first synthesized. Tri-n-butyltin methacrylate prepared according to Montermoso et al U.S. Pat. No. 3,016,369. Uninhibited methacrylic acid (37.8 ml, 0.444 mole) and tri-n-butyltin oxide (112.5 ml, 0.222 mole) were reacted in 200 of dischloromethane. Upon refluxing for 1 hour, 4.5 ml of water were collected azeotropically. After the reaction was completed, the solvent was evaporated under vacuum. The product ester was a yellow transparent liquid. The monomers were then copolymerized in a 1-liter, 3-necked flask equipped with a reflux condenser, a thermometer, such that it read the temperature of the reactants, and a mechanical stirrer. Tri-n-butyltin methacrylate (50 grams, 0.140 mole), uninhibited methyl methacrylate (50 grams, 0.580 mole), and benzoyl peroxide (0.5% by weight) were reacted in 200 ml of benzene. The solution polymerization was allowed to reflux for 8 hours. The resultant polymer was clear and could be cast as a film from the benzene solution.
Analysis calculated for P30: Sn, 25%. Found: Sn, 16,28%.
P41, POLY-TRI-n-BUTYLTIN-METHACRYLATE
The preparation of P41 was done in order to produce a homopolymer from its monomer. Tri-n-butyltin methacrylate was prepared as described above for P30. The purified monomer was then polymerized in benzene (200 ml) with methyl ethyl ketone peroxide (1% by weight) as the initiator. The polymerization took 3 hours. The resultant product was a colorless, transparent organometallic polymer which could be cast as a film from its benzene solution.
Analysis calculated for P41: Sn, 32%. Found: Sn, 29.05%.
P42, POLY(TRI-n-BUTYLTIN METHACRYLATE/METHYL METHACRYLATE)
P42 was prepared exactly as P30; however in this polymerization the molar ratio of the two monomers was varied. The tri-n-butyltin methacrylate (174.4 grams, 0.444 mole) was used in a 2:1 molar ratio with the uninhibited methyl methacrylate (20.0 grams, 0.222 mole). Benzoyl peroxide (1% by weight) was used as the initiator for the copolymerization. The product polymer was again a colorless, transparent material which could be cast as a film from the benzene solution.
Analysis calculated for P42: Sn, 30%. Found: 25.39%.
P43, POLY(TRI-n-BUTYLTIN METHACRYLATE/METHYL METHACRYLATE)
The polymerization of P43 was similar to that of P30. The same monomers, tri-n-butyltin methacrylate (174.4 grams, 0.444 mole) and uninhibited methyl methacrylate (40.0 grams, 0.444 mole) were copolymerized in equimolar quantities. The initiator for this solution polymerization was benzoyl peroxide (1% weight). P43 was a colorless, transparent copolymer that could be cast as a film from the benzene solution.
Analysis calculated for P43: Sn, 25%. Found: Sn, 21.03%.
P45, POLY(TRI-n-BUTYLTIN-METHACRYLATE/METHYL METHACRYLATE)
The synthesis of copolymer P45 was performed according to the method for P30. However, the molar ratio of the two monomers was varied such that 2 moles of tri-n-butyltin methacrylate (174.4 grams, 0.444 mole) were used for every 3 moles of uninhibited methyl methacrylate (60.0 grams, 0.666 mole). Benzoyl peroxide (1% weight) was the initiator for the polymerization. The organometallic copolymer was colorless and transparent and could be cast as a film from the benzene solution.
Since the preparation of the organometallic polystyrenes is similar, the preparation of S4, poly(tri-n-butyltin methacrylate/styrene), is given in detail as an example.
S4, POLY(TRI-n-BUTYLTIN METHACRYLATE/STYRENE)
Tri-n-butyltin methacrylate was synthesized according to the mothod of Montermoso, et al, U.S. Pat. No. 3,016,369 (1962). The product, a yellow, transparent liquid, was dissolved in pertroleum ether and recrystalized upon cooling below 20° C. Crystals of tri-n-butyltin methacrylate had a melting point of 18° C. Styrene uninhibited by vacuum distillation and the two monomers were then copolymerized in a 1-liter, 3-necked resin flask equipped with a reflux condenser, a thermometer, such that it read the temperature of the reactants, and a mechanical stirrer. Tri-n-butyltin methacrylate (0.053 mole), uninhibited styrene (0.192 mole), and 2,2'-azobis (2-methylpropionitrile) (0.1% by weight) were reacted in 50 of benzene. An additive, salicylaldehyde (0.2% by weight) was added prior to polymerization to act as an ultraviolet light absorber. The solution polymerization was allowed to reflux for 48 hours. The resultant polymer was a transparent, yellow tinted resin which could be cast as a film from the benzene solution. Tin analysis of S4: 16.64% Sn.
S5, POLY(TRI-n-BUTYLTIN METHACRYLATE/STYRENE)
S5 was synthesized by the general method described above. In this synthesis, equimolar quantities of tri-n-butyltin methacrylate (0.1 mole) and stryene (0.1 mole) were reacted with the azo initiator* in 85 ml of toluene for 96 hours. The resultant polymer was a transparent, orange tinted elastomer which could be cast as a film from the toluene solution. Analysis showed 20.90% Sn.
S6, POLY(TRI-n-BUTYLTIN METHACRYLATE/STYRENE)
S6 was prepared as above (1:1 molar ratio) in 300 ml of toluene for 144 hours. The antioxidant, 2,4-dinitrophenylhydrazine (2.0% by weight) was added before polymerization. The resultant polymer was a transparent, yellow tinted elastomer that could be cast as a film from the toluene solution. Analysis showed 23.73% Sn.
S7, POLY(TRI-n-BUTYLTIN METHACRYLATE/STYRENE)
S7 was prepared as above (1:1 molar ratio) in 200 ml of toluene for 264 hours. Both an antioxidant, 4-cyclohexyleyclohexanol (2.0% by weight) and ultraviolet light absorber, Uvinol M-40 (1.0% by weight) were additives in this synthesis. The resultant polymer was a transparent, orange tinted elastomer that could be cast as a film from the toluene solution. Analysis showed 25.43% Sn.
S8, POLY(TRI-n-BUTYLTIN METHACRYLATE/STYRENE)
S8 was prepared with the same additives as in S7. In this synthesis unequal molar quantities of tri-n-butyltin methacrylate (0.1 mole) and stryene (0.2 mole) were reacted with the azo initiator in 200 ml of toluene for 24 hours. The resultant polymer was a transparent, yellow tinted elastomer that could be cast as a film from the toluene solution. Analysis showed 20.46% Sn.
S10, POLY(TRI-n-BUTYLTIN METHACRYLATE)
Tri-n-butyltin methacrylate (0.1 mole) was polymerized using benzoyl peroxide (0.1% by weight) as the initiator in 200 ml of benzene for 24 hours. An antioxidant, Irganox 1076 (0.15% by weight) and an ultraviolet light absorber, Tinuvin P (0.25% by weight) were additives in this synthesis. The resultant polymer was a transparent, colorless elastomer that could be cast from the benzene solution. Analysis showed 31.53% Sn.
S11, POLY(TRI-n-BUTYLTIN METHACRYLATE/STYRENE)
S11 was synthesized as S10 in a 1:1 molar ratio of tri-n-butyltin methacrylate (0.1 mole) and styrene (0.1 mole). The resultant polymer was colorless and clear and could be cast as a film from the benzene solution. Analysis showed 30.01% Sn.
P51, POLY(TRI-n-BUTYLTIN METHACRYLATE/TRI-N-PROPYLTIN METHACRYLATE/METHYL METHACRYLATE)
The monomers of P51 were first synthesized. Tri-n-butyltin methacrylate was prepared as was tripropyltin methacrylate. These esters were isolated as crystals from petroleum ether. Methyl methacrylate was uninhibited. All uninhibited monomers were refrigerated below 40° F when stored for short periods of time. Tri-n-butyltin methacrylate (0.4 mole), tri-n-propyltin methacrylate (0.4 mole) and methyl methacrylate (0.4 mole) were reacted in 300 ml of benzene using benzoyl peroxide (0.5% by weight) as initiator. The reaction mixture was refluxed for 24 hours in a 1-liter, 3-necked resin flask equipped with a reflux condenser, a thermometer, such that it read the temperature of the reactants and a mechanical stirrer. The resultant polymer was clear and could be cast as a film from the benzene solution. Analysis showed 29.35% Sn.
P62, POLY(TRI-n-BUTYLTIN METHACRYLATE/TRI-N-PROPYLTIN METHACRYLATE/METHYL METHACRYLATE)
The preparation of P62 was identical to that of P51.
EXAMPLE 2
Three novel polymeric coating systems were formulated as follows:
______________________________________ ORGANOMETALLICFORMULATION No. 1 POLYMERIC COATING Component Parts by Weight______________________________________Organometallic Polymer 60Solvent 40______________________________________
In this formulation, the organometallic polymers used were all film forming and soluble in organic solvents. These polymers were poly(tributyltin acrylate), poly(tripropyltin acrylate), poly(tributyltin methacrylate), poly(tripropyltin methacrylate), and the tributyltin ester and the tripropyltin ester of poly(methyl vinyl ether/maleic acid). Organometallic copolymers of tributyltin methacrylate and methyl methacrylate in the following molar ratio 1:4, 1:1, 2:1, and 2:3, were also incorporated as organometallic polymers in this formulation. The incorporation of the methyl methacrylate into the polymer of tributylin methacrylate allowed various degrees of hardness to be obtained in the film. The more methyl methacrylate units in the copolymers, the more rigid the polymer became approaching the hardness of poly(methyl methacrylate). Organometallic monomers were also polymerized with styrene in place of methyl methacrylate. Furthermore, a terpolymer of tributyltin methacrylate, tripropyltin methacrylate and methyl methacrylate was prepared in a 1:1:1 molar ratio which was also used as the organometallic polymer in formulation No. 1. In addition, copolymers were prepared of two or more of the organometallic monomers and methyl methacrylate to produce an organometallic polymer suitable for use in antifouling formulation No. 1. Mixes of different organotin polymers were also used as the organometallic substituent in the formulation. Table I lists the mixtures used and their composition.
TABLE I______________________________________ Composition of organometallic polymersMixture # in mixture in a 1:1 ratio by weight______________________________________M1 Poly(tributyltin methacrylate)/ Poly(tripropyltin methacrylate)M3 Poly(tributyltin acrylate)/ Poly(tripropyltin acrylate)M4 Tributyltin ester of poly(methyl vinyl ether/maleic acid)/tripropyltin ester of poly(methyl vinyl ether/maleic acid)______________________________________
The combination of two organotin polymers with each possessing a different organotin group in the coating formulation increases the kill spectrum of the biocide material, since micro- and macro- faulants are known to be susceptible in varying degrees to different biocides. As the solvent in formulation No. 1, benzene, toulene or dichloromethane are used depending on the solubility of the organometallic polymer(s) in the polymeric coating.
The organometallic polymers which were powders were incorporated into either an acrylic or vinyl resin system. The composition of these resins system are listed as follows:
______________________________________FORMULATION ORGANOMETALLICNo. 2 VINYL RESIN SYSTEM Components Parts by Weight______________________________________Organometalic polymer 33.0Methyl isobutyl ketone 25.3Xylene 22.7Polyvinyl acetate resin(Union Carbide VAGH Resin) 11.4Organic Acid Rosin(Westvaccos WW Resin) 7.6______________________________________
______________________________________FORMULATION ORGANOMETALLICNo. 3 ACRYLIC RESIN SYSTEM Components Parts by Weight______________________________________Organometallic polymer 33.0Acrylic polyester* 66.0Methyl ethyl ketone peroxide 1.0______________________________________ *Castolite AP. available from Rohm and Haas, Co.
The organometallic polymers incorporated into either Formulation No. 2 or No. 3 resin system were the tributyltin ester of carboxymethyl cellulose, a high density poly(tributyltin methacrylate and poly(triphenyltin acrylate).
EXAMPLE 3
The antifouling performance of the low leaching organometallic formulation was proven at the United States Naval Shipyard at Pearl Harbor Hawaii which is a heavy fouling area. The panels were judged by the percentage of surface covered by fouling. The fouling rating is determined as 100 minus the percent covered by fouling. The polymeric materials showed 90-100% antifouling performance after many months of exposure to severe tropical fouling conditions as indicated in Table 2.
The low leaching organometallic polymer compositions of this invention permit control of marine fouling organisms in cluding bacteria, algae, tubeworms, hydroids, bryoyoans, marine borers, barnacles, Limnoria and tunicates. Many of the compositions are transparent and devoid of color. They are not deactivated by contact with steel or aluminum and do not contribute to galvanic corrosion.
TABLE 2__________________________________________________________________________ Formulation No. Organometallic % Anti-Organometallic Polymer Polymer Incor- fouling Monthsor Mixture No. porated In: Performance Exposed__________________________________________________________________________Poly(tributyltin acrylate) No. 1 100 16Poly(tripropyltin acrylate) No. 1 100 6Poly(tributyltin acrylate/tripropyltin acrylate) No. 1 100 6Poly(tributyltin methacrylate)* No. 2 & 90 19 No. 3Poly(tributyltin acrylate)* No. 1 100 16Poly(tripropyltin acrylate)* No. 1 90 17Poly(triphenyltin acrylate) No. 2 & 100 10 No. 3Poly(tributyltin methacrylate) No. 1 100 17Poly(tripropyltin methacrylate) No. 1 100 8Tributyltin ester of carboxy-methyl cellulose No. 2 90 5Tributyltin ester of poly(methyl vinyl ether/maleicacid) No. 1 100 17Tributyltin ester of poly(metyl vinyl ether/maleicacid)* No. 1 100 17Tripropyltin ester of poly(methyl vinyl ether/maleicacid) No. 1 100 16Tripropyltin ester of poly(methyl vinyl ether/maleicacid)* No. 1 100 12Poly(tributyltin methacrylate/methyl methacrylate)(1:4 molar ratio) No. 1 100 16Poly(tributyltin methacrylatemethyl methacrylate)(2:1 molar ratio) No. 1 100 17Poly(tributyltin methacrylate/methyl methacrylate)(1:1 molar ratio) No. 1 100 17Poly(tributyltin methacrylate/methyl methacrylate)(2:3 ratio) No. 1 100 17M1 No. 1 100 16M3 No. 1 100 16M4 No. 1 100 16Poly(tributyltin methacrylate/tripropyltin methacrylate/methyl methacrylate) No. 1 100 5Poly(tributyltin methacrylate/styrene) No. 1 100 9__________________________________________________________________________ *High Density Polymer
Differences in molecular weight of organometallic polymers did not affect the antifouling performance of those polymers tested. Exposure data indicated that the optimum antifouling performance may be expected from the organometallic polymers which are suitable for incorporation into formulation No. 1 and which possess a variety of organometallic groups attached to the polymer backbone.
EXAMPLE 4
The relationship between the sea water solubility biotoxicity of organometallic polymers and a standard paint system was determined. Relative sea water solubility of candidate organometallic polymers and a conventional tri-n-butyltin fluoride based antifouling paint was studied using a Burrell Wrist-Action Shaker. Each organometallic polymer was dried at 0.5 mm Hg and 180° C for 1 week. Approximately 5 gram samples of each polymer were placed in 50 ml of artificial sea water (Rila Marine Mix) which were then agitated continuously. The tri-n-butyltin fluoride based antifouling paint was coated on a fluorinated panel surface to facilitate removal. After air drying, 5 grams of this paint film were also placed in 50 ml of artificial sea water and agitated continuously. The sea water was decanted and replaced with a fresh 50 ml quantity every 3 days. The decanted water was analyzed for tin content using a Perkin Elmer Model 303 Atomic Absorbtion Spectrophotometer.
These results showed that methacrylic organometallic polymers have good antifouling capability, while releasing organometallic ions at least one order of magnitude less than a state-of-the-art tri-n-butyltin fluoride based antifouling paint. During five weeks of agitation in artificial sea water P42, poly(tri-n-butyltin methacrylate/methyl methacrylate), had released 45% less organotin ions than P41, poly(tri-n-butyltin methacrylate). P41 has a 33% greater molar substitution of tri-n-butyltin moieties than P42. This data indicates that the degree of leaching from an organometallic polymer may be controlled.
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.
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Marine structures which are designed to be submerged in an aqueous environt containing fouling organism are protected from fouling by the use of an organotin containing polymer wherein the tin is chemically bonded to the polymer. The polymer inhibits fouling of the exposed surface of the structure while minimizing the adverse effects on the surrounding environment due to reduced leaching of the organotin compound from the polymer.
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BACKGROUND OF THE INVENTION
[0001] The equipment used in the food processing industry varies by segment with the leading segments comprising meat and poultry, beverages, snack foods, vegetables, and dairy. While the equipment varies from segment to segment, the moving parts such as bearings, gears, and slide mechanisms are similar and often require lubrication. The lubricants most often used include hydraulic, refrigeration, compressor and gear oils, as well as all-purpose greases. These food industry oils must meet more stringent standards than other industry lubricants.
[0002] Due to the importance of ensuring and maintaining safeguards and standards of quality for food products, the food industry must comply with the rules and regulations set forth by the United States Department of Agriculture (USDA). The Food Safety inspection Service (FSIS) of the USDA is responsible for all programs involving the inspection, grading, and standardization of meat, poultry, eggs, dairy products, fruits, and vegetables. These programs are mandatory, and inspection of non-food compounds used in federally inspected plants is required.
[0003] The FSIS is custodian of the official list of authorized compounds for use in federally inspected plants. The official list (see page 11-1, List of Proprietary Substances and Non-food Compounds, Miscellaneous Publication Number 1419 (1989) by the Food Safety and Inspection Service, United States Department of Agriculture) states that lubricants and other substances that are susceptible to incidental food contact are considered indirect food additives under USDA regulations. Therefore, these lubricants, classified as either H-1 or H-2, are required to be approved by the USDA before being used in food processing plants. The most stringent classification, H-1, is for lubricants approved for incidental food contact. The H-2 classification, is for uses where there is no possibility of food contact, assures that no known poisons or carcinogens are used in the lubricant. One embodiment of the present invention pertains to an H-1 approved lubricating oil. The terms “H-1 approved oil” and “food grade” will be used interchangeably for the purpose of this application.
[0004] Although the USDA is no longer approving new ingredients and compositions, the H-1 classification is still recognized by the world food industry. NSF is now listing and approving the food grade classification.
[0005] In addition to meeting the requirements for safety set by federal regulatory agencies, the product must be an effective lubricant. Lubricating oils for food processing plants should lubricate machine parts, resist viscosity change, resist oxidation, protect against rusting and corrosion, provide wear protection, prevent foaming and resist the formation of sludge while in service. The product should also perform effectively at various lubrication regimes ranging from hydrodynamic thick film regimes to boundary thin film regimes.
[0006] The oxidation, thermal, and hydrolytic stability characteristics of a lubricating oil help predict how effectively an oil will maintain its lubricating properties over time and resist sludge formation. Hydrocarbon oils are partially oxidized when contacted with oxygen at elevated temperatures for prolonged periods of time. The oxidation process produces acidic bodies within the lubricating oil. These acidic bodies are corrosive to metals often present in food processing equipment, and, when in contact with both the oil and the air, are effective oxidation catalysts that further increase the rate of oxidation. Oxidation products contribute to the formation of sludges that can clog valves, plug filters, and result in overall breakdown of the viscosity characteristics of the lubricant. Under some circumstances, sludge formation can result in pluggage, complete loss of oil system flow, and failure or damage to machinery.
[0007] The thermal and hydrolytic stability characteristics of lubricating oil reflect primarily on the stability of the lubricating base oil properties and the oil additive package. The stability criteria monitor sludge formation, viscosity change, acidity change, and the corrosion tendencies of the oil. Hydrolytic stability assesses these characteristics in the presence of water. Inferior stability characteristics result in lubricating oil that loses lubricating properties over time and precipitates sludge.
[0008] Although such lubricants have been designed to be non-toxic as a food source contaminant, their lubricating properties are often less effective compared to conventional lubricants e.g., lubricants having ingredients not approved for direct food contact. The lubrication industry has, to some degree, overcome this problem by incorporating specialty additives into the lubricant compositions. For example, the inclusion of performance additives has been used to enhance antiwear properties, oxidation inhibition, rust/corrosion inhibition, metal passivation, extreme pressure, friction modification, foam inhibition, and lubricity. Such chemistries are described in the following patents: U.S. Pat. No. 5,538,654 (Lawate, et al.); U.S. Pat. No. 4,062,785 (Nibert); U.S. Pat. No. 4,828,727 (McAninch); U.S. Pat. No. 5,338,471 and U.S. Pat. No. 5,413,725 (Lai).
[0009] A drawback to the food-grade-lubricants described in the above patents relates to oxidation resistance, pour point characteristics, limited formulating capability for viscosity breadth, and limited viscosity protection. The lubricants often have poor rheology characteristics when subjected to prolonged heat and mechanical stress.
[0010] Therefore, there remains a need for a food-grade-lubricant that exhibits excellent hydrolytic stability, corrosion resistance, and anti-wear, with substantial improvements in oxidation resistance, pour point, viscosity index, viscosity breadth formulating capability, and viscosity stability when subjected to the thermal and mechanical stresses.
SUMMARY OF THE INVENTION
[0011] The invention relates to an improved food-grade-lubricant useful as hydraulic oil, circulating oil, drip oil, general purpose oil, grease base oil, cable oil, chain oil, spindle oil, gear oil, and compressor oil for equipment in the food service industry. Specifically, it relates to a composition comprising at least one polyalphaolefin base fluid, at least one food grade polyolester base fluid, and at least one food grade performance additive.
[0012] The invention provides compositions that contain more than 5 percent by weight of a polyolester base fluid. The invention provides compositions wherein component (c) comprises (i) one or more food grade antioxidants and/or (ii) one or more food grade metal passivators, wherein the metal passivators may comprise one or more food grade metal deactivators and/or one or more food grade corrosion inhibitors. The invention also provides compositions that contain more than 5 percent by weight of a polyolester base fluid and wherein component (c) comprises the combination of (i) one or more food grade antioxidants and (ii) one or more food grade metal deactivators and (iii) one or more food grade corrosion inhibitors.
[0013] The invention further provides compositions that also contain at least one food grade oil comprising at least one of the following: a synthetic ester, a white petroleum oil, and a severely hydrotreated petroleum oil.
[0014] The invention also provides a method for preparing a food-grade-lubricant composition comprising the steps of: a) providing at least one polyalphaolefin base fluid; b) providing at least one polyolester base fluid; c) providing at least one performance additive; and, d) blending the components to form the composition.
[0015] The invention also provides a method for lubricating a food industry mechanical device, the method comprising the steps of: lubricating the device with a composition comprising: (a) at least one polyalphaolefin base fluid; (b) at least one polyolester base fluid; and (c) at least one performance additive.
[0016] The invention provides improved food-grade-lubricants through the combination of polyalphaolefins and H-1 foodgrade polyolesters, particularly when the improved lubricants also contain a combination of one or more food grade antioxidants and one or more food grade metal deactivators. The compositions can provide enhanced oxidation resistance, pour point characteristics, and viscosities and are particularly useful as hydraulic oil, circulating oil, drip oil, general purpose oil, grease base oil, cable oil, chain oil, spindle oil, gear oil, and compressor oil for equipment in the food service industry.
DETAILED DESCRIPTION OF THE INVENTION
[0017] Various features and embodiments of the invention will be described below by way of non-limiting illustration.
[0018] By “food grade” it is meant a composition or lubricant that meets the criteria set forth by the United States Food and Drug Administration for foods additives and/or lubricants with incidental food contact, for example, as set out in 21 C.F.R. 178.3570 (2007), the contents of which are incorporated herein by reference, and/or which meet the criteria to achieve an “H1” classification from NSF International or an equivalent rating or classification from a counterpart standards setting body.
The Polyalphaolefin Base Fluid
[0019] The food-grade-lubricant compositions of the present invention comprise at least one polyalphaolefin. Polyalphaolefins are made by combining two or more alpha olefin molecules into an oligomer, or short-chain-length polymer. PAOs are all-hydrocarbon structures, and they contain no sulfur, phosphorus, or metals. Because they are wax-free, they have low pour points, usually below −40° C. Viscosity grades range from 2 to 100 cSt at 100° C., and viscosity indexes for all but the lowest grades exceed 140. PAOs have good thermal stability, but they require suitable antioxidant additives to resist oxidation. It is common to the industry that PAOs have limited ability to dissolve some additives and tend to shrink seals. It has been found that both problems are overcome by formulating with a polyolester base fluid and also using a food grade antioxidant and/or food grade metal deactivator.
[0020] All of the different viscosity grade PAOs mentioned above are included in this invention and are sanctioned by the FDA under 21 CFR 178.3570 USDA H-1, Lubricants with incidental Food Contact (not to exceed 10 ppm extraction into food). Under these sanctions, blending food grade polyolester base fluids into the formula will limit the use of the PAOs, providing an even safer product through dilution. Other useful polyalphaolefins are described in U.S. Pat. No. 6,534,454 incorporated herein by reference.
[0021] Examples of suitable PAOs include those at a viscosity at 100° C. of from 1 to 100 cSt. Suitable examples include PAO2, PAO4, PAO6, PAO8, PAO10, PAO40, PAO100, and mixtures thereof. In some embodiments the PAO of the present invention includes PAO4, PAO6, PAO8, PAO9, PAO10, or mixtures thereof. These designations generally refer to PAO with specific viscosities at 100° C., for example PAO2 is a PAO that has a kinematic viscosity of 2 cSt at 100° C.
[0022] In some embodiments the PAO used in the compositions of the present invention have a number average molecular weight of about 425 to about 2500.
[0023] The polyalphaolefin base fluid is present in the composition in a range of from about 1% to about 90% or from about 30% or 40% to about 70% or 60%. In some embodiments the polyalphaolefin is present in the composition in a range of from 1% to 98.99%, 94.99% or 88.99%. In some embodiments the polyalphaolefin is present in the composition in a range of from 1% to 98.5%, 94.5% or 89.5%
The Polyolester Base Fluid
[0024] The food-grade-lubricant compositions of the present invention comprise at least one polyolester base fluid. Polyolesters (POE) are made by combining a polyol with a carboxylic acid. In some embodiments the polyolester base fluid is a reaction product of at least one neopentyl polyhydric alcohol and at least one monocarboxylic acid. The POE base fluid of the present invention must be food grade to be suitable. However, included in this invention is the use of POE base fluids that are currently considered food grade as well as other POE base fluids that have not yet been determined to be food grade, but which might be in the future. In other words, the use of POE base fluids that receive H-1 food grade designation at some point in the future are also contemplated under the current invention.
[0025] Properties of these POE base fluids, such as viscosity, viscosity-temperature behavior, oxidation resistance, evaporation loss, hydrolytic stability, and flash point can be modified by selection of the polyol and monocarboxylic acids used to prepare the fluid, and/or by the manufacturing process employed. One of ordinary skill in the art may make such modifications as desired, depending on the end use of the product.
[0026] The neopentyl polyhydric polyols suitable for use in preparing the POE base fluids are not overly limited. The neopentyl polyhydric polyols may have any suitable number of hydroxyl groups. It may be preferred that the neopentyl polyhydric polyol has about 2 or 4 to about 12 or 8 hydroxyl groups. Commercially available polyols of this type are, for example, neopentyl glycol, trimethylolpropane, trimethylolethane, pentaerythritol, dipentaerythritol, tripentaerythritol, and tetrapentaerythritol. Preferred polyols may be dipentaerythritol, monopentaerythritol and trimethylolpropane or combinations thereof, although tripentaerythritol and tetrapentaerythritol may be utilized.
[0027] The selected neopentyl polyhydric alcohol is reacted with at least one monocarboxylic acid. More than one may be combined; it may be desirable that at least two, three, four, or five monocarboxylic acids are used. Each monocarboxylic acid may have a structure different from the other(s), differing either in type and/or number of chemical constituents that make up the structure or in the arrangement of the constituents relative to one another (e.g., branched chains versus straight chains). The monocarboxylic acid(s) may be straight chain (linear) or branched chain (or any combination of these). It may be preferred that the monocarboxylic acid(s) (branched or straight chain) contain about 2 to about 20 carbon atoms, about 5 to about 12 carbon atoms, or about 5 to about 10 carbon atoms. In some circumstances, shorter chain length linear carboxylic acids may be preferred because thermal stability may decrease as carbon chain length increases.
[0028] Examples of linear monocarboxylic acids that may be used include pentanoic acid, decanoic acid, hexanoic acid, heptanoic acid, octanoic acid and nonanoic acid. Branched chain monocarboxylic acids may also be used, either alone or in combination with the linear or straight chained monocarboxylic acids. For example, one may increase the amount of branched chain monocarboxylic acids to modify (raise) the viscosity of the end composition. Branched chain monocarboxylic acids that may be suitable include, without limitation, 2-ethylhexanoic acid and 3,5,5-trimethylhexanoic acid (isononanoic acid).
[0029] In an embodiment, the base oil is prepared from the reaction of at least one neopentyl polyhydric alcohol that includes dipentaerythritol and at least one monocarboxylic acid that is pentanoic acid, heptanoic acid, 3,5,5-trimethyl hexanoic acid and/or any combination of these.
[0030] In some embodiments the POE base fluid base fluid includes esters of neopentyl glycol, glycerol, trimethylol propane, pentaerythritol, dipentaerythritol, tripentaerythritol, or combinations thereof reacted with carboxylic acids represented by the formula HOC(O)R 1 , where R 1 is a saturated, cyclic, straight chain or branched hydrocarbon radical containing from 4 to 10 carbon atoms.
[0031] The POE base fluids used in the compositions of the present invention must be food grade. Commercially available POE base fluids include LEXOLUBE™ FG-68 HX1, FG-100 HX1, FG-220 HX1 and FG-350 HX1, Priolube™ 3970 all available from Inolex™ and Croda™.
[0032] The polyolester base fluid is present in the composition in a range of from about 1% to about 90% or from about 30% or 40% to about 70% or 60%. In some embodiments the foodgrade polyol ester is present in the composition in a range of from 1%, 5%, 7% or 10% to about 98.99%. In some embodiments the foodgrade polyol ester is present in the composition in a range of from 1%, 5%, 7% or 10% to about 98.5%.
[0033] In some embodiments the compositions described herein contain a minimum amount of polyolester base fluid. This minimum amounts may be at least 1%, and in some embodiments at least 5%, 7% or even 10%. In some embodiments the compositions described herein contain a minimum amount of polyalphaolefin base fluid. This minimum amounts may be at least 1%, and in some embodiments at least 5%, 10%, 15% or even 50%.
The Food Grade Performance Additives
[0034] The food grade lubricant compositions of the present invention comprise at least one food grade performance additive. Food grade performance additives are additives that have H-1 approval as required by the United States Department of Agriculture and/or are safe for contact with food. It is understood that the H-1 designation will ultimately relate to a comparable classification in countries outside the United States in most cases.
[0035] In some embodiments the compositions of the present invention include an antioxidant. In some embodiments the compositions of the present invention include a metal passivator, wherein the metal passivator may include a corrosion inhibitor and/or a metal deactivator. In some embodiments the compositions of the present invention include a corrosion inhibitor. In still other embodiments the compositions of the present invention include a combination of a metal deactivator and a corrosion inhibitor. In still further embodiments the compositions of the present invention include the combination of an antioxidant, a metal deactivator and a corrosion inhibitor. In any of these embodiments the compositions may further include one or more additional performance additives.
[0036] The antioxidants suitable for use in the present invention are not overly limited. However in some embodiments the antioxidant must be food grade and must not be used in an amount that would remove the food grade classification from the additive and/or the resulting composition.
[0037] Suitable food grade FDA approved antioxidants include butylated hydroxytoluene (BHT), butylatedhydroxyanisole (BHA), phenyl-a-naphthylamine (PANA), octylated/butylated diphenylamine, high molecular weight phenolic antioxidants, hindered bis-phenolic antioxidant, di-alpha-tocopherol, di-tertiary butyl phenol. Other useful antioxidants are described in U.S. Pat. No. 6,534,454 incorporated herein by reference
[0038] In some embodiments the food grade antioxidant includes one or more of:
(i) Hexamethylenebis(3,5-di-tert-butyl-4-hydroxyhydrocinnamate), CAS registration number 35074-77-2, available commercially from Ciba Specialty Chemical Company; (ii) N-phenylbenzenamine, reaction products with 2,4,4-trimethylpentene, CAS registration number 68411-46-1, available commercially from Ciba Specialty Chemical Company; (iii) Phenyl-a-and/or phenyl-b-naphthylamine, for example N-phenyl-ar-(1,1,3,3-tetramethylbutyl)-1-naphthalenamine, available commercially from Ciba Specialty Chemical Company; (iv) Tetrakis[methylene(3,5-di-tert-butyl-4-hydroxyhydrocinnamate)] methane, CAS registration number 6683-19-8; (v) Thiodiethylenebis (3,5-di-tert-butyl-4-hydroxyhydrocinnamate), CAS registration number 41484-35-9, which is also listed as thiodiethylenebis (3,5-di-tert-butyl-4-hydroxy-hydro-cinnamate) in 21 C.F.R. §178.3570; (vi) Butylatedhydroxytoluene (BHT); (vii) Butylatedhydroxyanisole (BHA), (viii) Bis(4-(1,1,3,3-tetramethylbutyl)phenyl) amine, available commercially from Ciba Specialty Chemical Company; and (ix) Benzenepropanoic acid, 3,5-bis(1,1-dimethylethyl)-4-hydroxy-, thiodi-2,1-ethanediyl ester, available commercially from Ciba Specialty Chemical Company.
[0048] The antioxidants may be present in the composition from 0.01% to 6.0% or from 0.02%, 0.03%, 0.05%, 0.1% to 6%, 4%, 2%, 1% or even 0.5%. The additive may be present in the composition at 1%, 0.5%, or less. These various ranges are typically applied to all of the antioxidants present in the overall composition. However in some embodiments these ranges may also be applied to individual antioxidants, so long as the food grade limitations are taken into account.
[0049] The metal passivators suitable for use in the present invention are not overly limited and may include both metal deactivators and corrosion inhibitors. However in some embodiments the additives must be food grade and must not be used in an amount that would remove the food grade classification from the additive and/or the resulting composition.
[0050] Suitable metal deactivators include triazoles or substituted triazoles. For example, tolyltriazole or tolutriazole may be utilized in the present invention. Suitable examples of food grade metal deactivator include one or more of:
(i) One or more tolu-triazoles, for example N,N-Bis(2-ethylhexyl)-ar-methyl-1H-benzotriazole-1-methanamine, CAS registration number 94270-86-70, sold commercially by Ciba-Geigy under the trade name Irgamet 39; (ii) One or more fatty acids derived from animal and/or vegetable sources, and/or the hydrogenated forms of such fatty acids, for example Neo-Fat™ which is commercially available from Akzo Novel Chemicals, Ltd.
[0053] Suitable food grade corrosion inhibitors include one or more of:
(i) N-Methyl-N-(1-oxo-9-octadecenyl)glycine, CAS registration number 110-25-8; (ii) Phosphoric acid, mono- and diisooctyl esters, reacted with tert-alkyl and (C12-C14) primary amines, CAS registration number 68187-67-7; (iii) Dodecanoic Acid; (iv) Triphenyl phosphorothionate, CAS registration number 597-82-0; and (v) Phosphoric acid, mono- and dihexyl esters, compounds with tetramethylnonylamines and C11-14 alkylamines.
[0059] In one embodiment, the metal passivator is comprised of a corrosion additive and a metal deactivator wherein the corrosion inhibitor and the metal deactivator are food grade and comply with FDA regulations. One useful additive is the N-acyl derivative of sarcosine, such as an N-acyl derivative of sarcosine. One example is N-methyl-N-(1-oxo-9-octadecenyl) glycine. This derivative is available from Ciba-Geigy under the trade name SARKOSYL™ O. Another additive is an imidazoline such as Amine O™ commercially available from Ciba-Geigy.
[0060] The metal passivators may be present in the composition from 0.01% to 6.0% or from 0.02%, 0.03%, 0.05%, 0.1% to 6%, 4%, 2%, 1% or even 0.5%. The additive may be present in the composition at 0.05% or less. These various ranges are typically applied to all of the metal passivator additives present in the overall composition. However in some embodiments these ranges may also be applied to individual corrosion inhibitors and/or metal deactivators, so long as the food grade limitations are taken into account. The ranges above may also be applied to the combined total of all corrosion inhibitors, metal deactivators and antioxidants present in the overall composition.
[0061] The compositions described herein may also include one or more additional performance additives. Suitable additives include antiwear inhibitors, rust/corrosion inhibitors and/or metal deactivators (other than those described above), pour point depressants, viscosity improvers, tackifiers, extreme pressure (EP) additives, friction modifiers, foam inhibitors, emulsifiers, and demulsifiers.
[0062] To prevent wear on the metal surface, the present invention utilizes an anti-wear inhibitor/EP additive and friction modifier. Anti-wear inhibitors, EP additives, and friction modifiers are available off the shelf from a variety of vendors and manufacturers. Some of these additives can perform more than one task and any may be utilized in the present invention, as long as they are food grade. One food grade product that can provide anti-wear, EP, reduced friction and corrosion inhibition is phosphorus amine salt such as Irgalube 349, which is commercially available from Ciba-Geigy. Another food grade anti-wear/EP inhibitor/friction modifier is a phosphorus compound such as is triphenyl phosphothionate (TPPT), which is commercially available from Ciba-Geigy under the trade name Irgalube TPPT. The anti-wear inhibitors, EP, and friction modifiers are typically about 0.1% to about 4% of the composition and may be used separately or in combination.
[0063] In some embodiments the composition further includes an additive from the group comprising: viscosity modifiers-including, but not limited to, ethylene vinyl acetate, polybutenes, polyisobutylenes, polymethacrylates, olefin copolymers, esters of styrene maleic anhydride copolymers, hydrogenated styrene-diene copolymers, hydrogenated radial polyisoprene, alkylated polystyrene, fumed silicas, and complex esters; and food grade tackifiers like natural rubber solubilized in food grade oils.
[0064] The addition of a food grade viscosity modifier, thickener, and/or tackifier provides adhesiveness and improves the viscosity and viscosity index of the lubricant. Some applications and environmental conditions may require an additional tacky surface film that protects equipment from corrosion and wear. In this embodiment, the viscosity modifier, thickener/tackifier is about 1 to about 20 weight percent of the lubricant. However, the viscosity modifier, thickener/tackifier can be from about 0.5 to about 30 weight percent. An example of a food grade material that can be used in this invention is Functional V-584 a Natural Rubber viscosity modifier/tackifier, which is available from Functional Products, Inc., Macedonia, Ohio. Another example is a complex ester CG 5000 that is also a multifunctional product, viscosity modifier, pour point depressant, and friction modifier from Inolex Chemical Co, Philadelphia, Pa.
[0065] Other food grade oils and/or components may be also added to the composition in the range of about 0.1 to about 30%. These food grade oils could include white petroleum oils, synthetic esters (as described in patent U.S. Pat. No. 6,534,454), severely hydro-treated petroleum oil (known in the industry as “Group II or III petroleum oils”).
Industrial Application
[0066] In some embodiments each of the composition ingredients of the composition described herein have H-1 approval as required by the United States Department of Agriculture. It is understood that the H-1 designation will ultimately relate to a comparable classification in countries outside the United States in most cases.
[0067] The compositions described herein may be prepared by blending the various components together. The means of blending and/or order of addition is not overly limited.
[0068] Although the composition of the present invention is particularly useful as a lubricant in the food service industry, it is not limited to applications that require direct food contact. For example, the unique combination of properties allows the inventive lubricant to be used in any application wherein a continuous and efficient reduction in friction is required. Examples may include engine oil, hydraulic fluid, grease, etc.
[0069] The food-grade-lubricant compositions described above can be used in all types of food processing equipment.
[0070] In some embodiments the compositions of the present invention are: (i) from 5 or 10 to 40 or 25% food grade polyol ester base fluid, (ii) from 70 or 72 to 87 or 90% polyalphaolefin base fluid, (iii) from 0.05, 0.5, 1.0 or 2.0 to 2.5% antioxidants, (iv) from 0.01, or 0.05 to 0.1 or 0.07 metal deactivators and/or corrosion inhibitors, or (v) any combination thereof.
EXAMPLES
[0071] The invention will be further illustrated by the following examples, which sets forth particularly advantageous embodiments. While the examples are provided to illustrate the present invention, they are not intended to limit it. Unless otherwise noted, each of the additives and additive packages described below may contain some amount of diluent oil or similar material.
Example 1
[0072] A food grade lubricant is prepared by blending a polyalphaolefin base fluid, PAO-6 with an antioxidant additive package and a metal passivator package. The additive package contains (i) N-phenyl-ar-(1,1,3,3-tetramethylbutyl)-1-naphthalenamine, (ii) N-phenylbenzenamine reaction products with 2,4,4-trimethylpentene, and (iii) 1,6-hexamethylenebis(3,5-di-tert-butyl-4-hydroxyhydrocinnamate), where the antioxidants are present in the package at weight ratios of 2.5:2.5:1 respectively. The metal passivator package contains Neo-Fat™, a fatty acid corrosion inhibitor, and Irgamet™ 39, a benzotriazole metal deactivator, in a weight ratio of 2.5:1 respectively.
[0073] The resulting blend contains 0% food grade polyolester, 98.7% polyalphaolefin, 2.2% of the antioxidant additive package, and 0.07% of the metal passivator package. The resulting blend has a kinematic viscosity at 40° C. of 32 cSt.
Example 2
[0074] A food grade lubricant is prepared by blending a food grade polyolester base fluid and a blend of two polyalphaolefin base fluids, PAO-8 and PAO-6 where the weight ratio of the polyalphaolefin base fluids in the blend is 1.2:1 respectively. An antioxidant additive package is added to the blend. The antioxidant package contains equal parts on a weight basis of (i) N-phenyl-ar-(1,1,3,3-tetramethylbutyl)-1-naphthalenamine, (ii) bis(4-(1,1,3,3-tetramethylbutyl)phenyl) amine, (iii) N-phenylbenzenamine reaction products with 2,4,4-trimethylpentene, (iv) 1,6-hexamethylenebis(3,5-di-tert-butyl-4-hydroxyhydrocinnamate), and (v) benzene-propanoic acid, 3,5-bis(1,1-dimethylethyl)-4-hydroxy-, thiodi-2,1-ethanediyl ester.
[0075] The resulting blend contains 10% food grade polyolester, 87.5% of the polyalphaolefin blend and 2.5% of the antioxidant additive package (such that each antioxidant is present at 0.50%). The resulting blend has a kinematic viscosity at 40° C. of 39 cSt.
Example 3
[0076] A food grade lubricant is prepared by blending a food grade polyolester base fluid and a blend of two polyalphaolefin base fluids, PAO-8 and PAO-6 where the weight ratio of the polyalphaolefin base fluids in the blend is 3.31 respectively. The antioxidant additive package described in Comparative Example 2 is added to the blend. A metal passivator additive package is also added to the blend. The metal passivator package contains Neo-Fat™, a fatty acid corrosion inhibitor, and Irgamet™ 39, a benzotriazole metal deactivator, in a weight ratio of 2.5:1 respectively.
[0077] The resulting blend contains 25% food grade polyolester, 72.43% of the polyalphaolefin blend, 2.5% of the antioxidant additive package (such that each antioxidant is present at 0.50%) and 0.07% of the metal activator additive package. The resulting blend has a kinematic viscosity at 40° C. of 46 cSt.
Example 4
[0078] A food grade lubricant is prepared following the procedures of Example 3. The resulting blend contains 25% food grade polyolester, 72.43% of the polyalphaolefin blend, 2,5% of the antioxidant additive package (such that each antioxidant is present at 0.50%) and 0.07% of the metal activator additive package. The resulting blend has a kinematic viscosity at 40° C. of 39 cSt.
[0079] Each of the examples is tested in a hot room compressor test. The involves supply each test lubricant to a variable speed drive rotary screw compressor operating at 110° C. (230° F.) and 100 psia. Samples of the lubricant are taken every 160 hours of compressor operation time and analyzed to evaluate the performance of the lubricant. Each sample is analyzed to determine the total acid number (TAN) of the lubricant, as measured by ASTM D974. A higher TAN is an indication that a lubricant is losing its effectiveness. A lubricant is generally considered to be past its usable service live when its TAN exceeds a value of 2.0 or even 1.0. The longer the period of operation time where a lubricant's TAN is below 2.0 or even 1.0, the longer the lubricant's service life and the better the lubricant's performance.
[0080] The results of testing completed is summarized in the table below:
[0000]
TABLE 1
Summary of Hot Room Compressor Results
Ex 1
Ex 2
Ex 3
Ex 4
TEST
TAN
TEST
TAN
TEST
TAN
TEST
TAN
HRS
Values 1
HRS
Values 1
HRS 2
Values 1
HRS 2
Values 1
0
0.21
0
0.25
0
0.25
0
0.24
1
0.63
1
0.25
1
0.18
1
0.33
122
0.33
98
0.25
172
0.08
167
0.35
288
0.44
266
0.25
342
0.17
336
0.32
462
0.24
433
0.25
532
0.21
509
0.33
626
0.38
606
0.25
697
0.24
670
0.32
795
0.38
770
0.25
842
0.24
838
0.36
939
0.33
938
0.25
1011
0.23
1030
0.48
987
0.41
1106
0.25
1166
0.25
1179
0.49
1107
0.52
1275
0.25
1333
0.33
1341
0.45
1276
0.49
1442
0.25
1525
0.36
1509
0.41
1436
0.77
1610
0.25
1668
0.36
1678
0.45
1604
1.95
1725
0.25
1839
0.40
1870
0.41
1772
1.11
1895
0.25
2004
0.43
2013
0.40
1923
1.11
2064
0.28
TEST
2183
0.44
2091
1.25
2233
1.65
INTERRUPTED
2349
0.42
2229
1.31
2303
4.10
2521
0.42
2399
1.56
2378
19.60
2617
0.41
2566
2.23
TEST
2850
0.45
2739
3.24
STOPPED
3019
0.49
2811
4.00
3184
0.50
TEST
3376
0.50
STOPPED
3520
0.56
3687
0.55
3875
0.60
4027
0.65
4178
0.61
4345
0.67
4516
0.72
4680
0.74
4854
1.14
5020
1.23
5186
1.71
5219
1.67
5294
1.82
5386
2.63
TEST
STOPPED
1 TAN values are measured per ASTM D974.
2 The Example 3 test ended after the 2004 hour sample for reasons unrelated to the lubricant. Example 4 is essentially a repeat of Example 3 that shows how the results of Example 3 would have come out had that test been able to run to completetion.
[0081] The results show that the compositions of the present invention provide significantly improved lubricant performance as demonstrated by the extended useable service live (time of use before the TAN of the lubricant exceeds 1.0) of Examples 2 and 3 and 4 compared to Example 1. Example 1 shows that the use of antioxidants and metal passivators in a PAO-based lubricant does not perform well (the sample exceeds a TAN of 1.0 before 2233 hours of testing and exceed a TAN of 2.0 before 2303 hours of testing). Example 2 shows that a blend of PAO and a food grade polyol ester, with an additional additive package can perform better than Example 1. Furthermore Example 3 shows that a blend of PAO and food grade polyol ester in combination with a food grade additive package that combines antioxidants and metal passivators provides a significant improvement in performance compared to Example 1, and even compared to Example 2. Example 4, which is prepared using the same procedure and amounts of materials as Example 3, also shows this significant improvement, compared to Example 1, and even compared to Example 2 (the sample exceeds a TAN of 1,0 after 4854 hours of testing and exceed a TAN of 2.0 before 5386 hours of testing). The results also show that Examples 3 and 4 had very similar performance up until the test for Example 3 had to be discontinued. At about 2000 hours of run time, Examples 3 and 4 both had TAN values of about 0.4.
[0082] The performance of the lubricants may be evaluated by comparing the amount of test time that passes until the TAN of the lubricant exceeds 1.0. In some embodiments the lubricants may be evaluated by comparing, the amount of test time that passes until the TAN of the lubricant exceeds 2.0.
[0083] Each of the documents referred to above is incorporated herein by reference. Except in the Examples, or where otherwise explicitly indicated, all numerical quantities in this description specifying amounts of materials, reaction conditions, molecular weights, number of carbon atoms, and the like, are to be understood as modified by the word “about.” Unless otherwise indicated, all percent values, ppm values and parts values are on a weight basis. Unless otherwise indicated, each chemical or composition referred to herein should be interpreted as being a commercial grade material which may contain the isomers, by-products, derivatives, and other such materials which are normally understood to be present in the commercial grade. However, the amount of each chemical component is presented exclusive of any solvent or diluent oil, which may be customarily present in the commercial material, unless otherwise indicated. It is to be understood that the upper and lower amount, range, and ratio limits set forth herein may be independently combined. Similarly, the ranges and amounts for each element of the invention can be used together with ranges or amounts for any of the other elements. As used herein, the expression “consisting essentially of” permits the inclusion of substances that do not materially affect the basic and novel characteristics of the composition under consideration.
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The invention relates to an improved food-grade-lubricant useful as hydraulic oil, circulating oil, drip oil, general purpose oil, grease base oil, cable oil, chain oil, spindle oil, gear oil, and compressor oil for equipment in the food service industry. Specifically, it relates to a composition comprising at least one polyalphaolefin base fluid, at least one food grade polyolester base fluid, and at least one food grade performance additive.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of provisional patent applications Ser. No. 60/731,573, filed 2005 Oct. 28 and Ser. No. 60/754,814, filed Dec. 29, 2005 by the present inventor.
FEDERALLY SPONSORED RESEARCH
Not Applicable
SEQUENCE LISTING OR PROGRAM
Not Applicable
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the utilization of wind energy, and more specifically, to the utilization of wind energy through the use of wind turbines.
2. Prior Art
A wind turbine is a machine for converting the kinetic energy of wind into mechanical energy. All of the known wind turbines can produce useful energy only as a result of sufficient wind speed. Generally speaking, the bigger is the wind turbine, the larger is the amount of useful energy that it can produce. On the other hand, the bigger is the size of wind turbine, the higher is the wind speed required for the wind turbine to produce useful energy. However, there are many locations in the world where the prevailing wind speeds are too low for the known wind turbines to produce useful energy. Accordingly, the capabilities of current wind turbines to practically utilize wind energy are limited.
U.S. Pat. No. 6,942,454 to Ohlmann (2005) discloses a vertical axis wind turbine. However, this wind turbine cannot be used for producing a high power output because the turbine is limited to only two rotors. Additionally, the structure of the wind turbine disclosed in Ohlmann is ill-equipped for production because it is non-rigid and unreliable and can operate under only low wind speeds and when rotors are short.
SUMMARY OF THE INVENTION
The wind power plant of the present invention uses rotors having a diameter that is smaller than the diameter of the rotors in presently utilized wind turbines. Consequently, an output shaft on the present invention will rotate with higher speed than its counterpart in the known wind turbines. Thus the wind power plant of the present invention can produce useful energy at lower wind speeds as compared to the presently utilized wind turbines.
Accordingly, the present invention has following advantages:
1. It allows for the production of useful energy in world areas with prevailing low wind speeds in which the currently utilized wind turbines cannot produce useful energy.
2. It allows for the production of useful energy both at wind speeds when the presently utilized wind turbines can, and at wind speeds lower when the presently utilized wind turbines cannot produce useful energy.
3. It allows for the production of more useful energy per year than the presently utilized wind turbines.
4. It allows for the creation of high power wind plants in word areas where low wind speeds prevail.
In addition to the above-stated advantages, the rotors in the present invention have rectilinear blades arranged along of the axis of rotor rotation. Accordingly, to manufacture the rotors of the present invention, one does not need any complicated expensive machinery, any expensive composite materials, or any skilled specialists, As a result of including the above-listed advantages, the present invention is capable of both efficient production of clean and cheap energy and of word-wide utilization.
The present invention has many embodiments. All of the embodiments comprise the following four main elements:
a foundation;
at least one supporting structure, only one supporting structure being installed on the foundation;
a carrying construction arranged on the supporting structures, the carrying construction having a vertical axis and being rotatable about the vertical axis; and
at least one rotor positioned on the carrying construction.
An element of the wind power plant on which the rotors are positioned is called “the carrying construction” in this specification and in the claims.
There are two main groups of the invention. First group represents embodiments, where the supporting structure installed on the foundation is not fixedly secured to it. The carrying construction is fixedly secured to the supporting structures. The carrying construction is rotatable about its vertical axis jointly with the supporting structures. Second group represents embodiments, where the supporting structure installed on the foundation is fixedly secured to it. The carrying construction is rotatable about its vertical axis independently from the supporting structure installed on the foundation.
In simplest cases, the carrying construction is a pillar or a horizontal beam. On this pillar or beam at least one rotor is positioned. As the quantity of rotors increases, the carrying construction becomes a pillar which has either branching horizontal beams only, inclined beams only, or horizontal and inclined beams together.
In other cases, the carrying construction is simply a very long horizontal beam. Yet in other cases when it is necessary for a large quantity of rotors to be positioned on the carrying construction, the carrying construction has a pillar arranged along its vertical axis with at least two horizontal beams branching off in opposite directions, and at least two supplementary pillars bearing against supplementary supporting structures. In another case, when it is necessary for a large quantity of rotors to be positioned on the carrying construction, the carrying construction is a very long horizontal beam having at least two supplementary pillars bearing against supplementary supporting structures.
In this specification and in claims, the pillars and the beams are referred to as members of the carrying construction.
In the simplest cases, a single rotor is positioned on the carrying construction. This single rotor has either a horizontal or a vertical axis of rotation. In cases when two rotors are positioned on the carrying construction, the rotors have either horizontal axes of rotation only, vertical axes of rotation only, or inclined axes of rotation only. In cases when more then two rotors are positioned on the carrying construction, the rotors have either horizontal axes of rotation only, vertical axes of rotation only, inclined axes of rotation only, or different combinations of horizontal, vertical, and inclined axes of rotation.
Each rotor has at least two blades arranged along its axis of rotation. The rotors are positioned on the pillars and on the beams in one or two rows along the borders of these carrying construction members.
The invention has other design features as well. Further features of the invention will be apparent from the attached drawings and a description of the illustrative embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view of one embodiment of the invention, which has rotors with horizontal and vertical axes of rotation.
FIG. 2 is a right-side view of the embodiment shown in FIG. 1 .
FIG. 3 is a front view of another embodiment of the invention, which has rotors with horizontal and vertical axes of rotation.
FIG. 4 is a right-side view of the embodiment shown in FIG. 3 .
FIG. 5 is a front view of another embodiment of the invention, which has a single rotor with a horizontal axis of rotation.
FIG. 6 is a partial right-side view of the embodiment shown in FIG. 5 .
FIG. 7 is a transverse sectional view taken on line A—A in FIGS. 1 and 3 .
FIG. 8 is a simplified front view of another embodiment of the invention, which has two or four rotors with horizontal axes of rotation.
FIG. 9 is a simplified front view of another embodiment of the invention, which has two or four rotors with horizontal axes of rotation and one or two rotors with vertical axes of rotation.
FIG. 10 is a simplified front view of another embodiment of the invention, which has two rotors with horizontal axes of rotation and two rotors with inclined axes of rotation.
FIG. 11 is a simplified front view of another embodiment of the invention, which has tow rotors with horizontal axes of rotation, two rotors with inclined axes of rotation, and one or two rotors with vertical axes of rotation.
FIG. 12 is a simplified front view of another embodiment of the invention, which has either one, or two, or four rotors with vertical axes of rotation.
FIG. 13 is a simplified front view of another embodiment of the invention, which has four rotors with inclined axes of rotation.
FIG. 14 is a simplified front view of another embodiment of the invention, which has two rotors with inclined axes of rotation and one or two rotors with vertical axes of rotation.
FIG. 15 is a simplified front view of another embodiment of the invention, which has two or four rotors with horizontal axes of rotation.
FIG. 16 is a simplified front view of another embodiment of the invention, which has two rotors with inclined axes of rotation and one or two rotors with vertical axes of rotation.
FIG. 17 is a simplified front view of another embodiment of the invention, which has for rotors with inclined axes of rotation.
FIG. 18 is as simplified front view of another embodiment of the invention, which has a large number of rotors with horizontal axes of rotation.
FIG. 19 is a simplified front view of another embodiment of the invention, which has a large number of rotors with horizontal axes of rotation.
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1 , 2 and 7 illustrate one of the embodiments of the wind power plant of the present invention. The plant includes a supporting structure (mast, tower) 21 and a carrying construction 23 . The carrying construction 23 is arranged on the supporting structure 21 and has a vertical axis 25 . In this embodiment, the carrying construction 23 is fixedly secured to the supporting structure 21 , i.e., they are integral. The carrying construction 23 is rotatable jointly with the supporting structure 21 about the vertical axis 25 . This is provided by a round bar 27 fixed in a foundation 29 . The supporting structure 21 is installed on turning elements (wheels or rollers) 31 . The turning of the plant is enabled by a truck 33 . The truck 33 is fixed to the supporting structure 21 by a connecting construction 35 . The truck 33 also prevents the plant from turning over under wind influence since it is arranged on the side opposed to the wind pressure. Referring to FIG. 2 , an arrow 37 shows the wind direction. The truck 33 is driven by a motor (not shown).
Referring back to FIG. 1 , the supporting structure has a platform 39 . Around the platform 39 , brackets 41 are installed on the foundation 29 . On the brackets 41 other turning elements 43 are positioned, which also act to prevent the plant from turning over.
On the carrying construction 23 rotors 45 having horizontal axes of rotation 47 and rotors 49 having vertical axes of rotation 51 are positioned. Referring to FIG. 7 , the rotors have at least two blades 53 arranged along the axes of rotation. Referring back to FIG. 1 , each rotor has a shaft 55 , which rotates in bearings 57 placed in arms 59 and 61 . The arms 59 and 61 are attached to the carrying construction 23 . The rotors are arranged in two rows. The shafts of aligned rotors are connected by couplings 63 .
There are vertical shafts 65 and 67 on the carrying construction 23 . The shafts 55 of the vertical rotors 49 are connected by couplings 63 to the vertical shafts 65 and 67 . The shafts 55 of the horizontal rotors 45 are connected to the vertical shafts 65 and 67 by a mechanical transmission consisting of two bevel-gears 69 . The vertical shafts 65 and 67 are connected to each other by a mechanical transmission consisting of two gears 71 . One of the vertical shafts 67 is connected by coupling 63 to an input shaft of a gear-box 73 . An output shaft of the gear-box 73 is connected by a mechanical transmission consisting of two gears 75 to a driven device 77 (a generator or a pump).
Referring to FIG. 7 , the rotors 45 and 49 are positioned along the borders 79 and 81 of the carrying construction 23 . The rotors are arranged so that less than half of the rotors' diameter protrudes out of the borders of the carrying construction.
The transverse section of the carrying construction may have a special shape in locations where the rotors are positioned. This section may be shaped by a first straight line 83 arranged nearest to said rotors, and two other straight lines 85 and 87 adjoining said first straight line at an acute included angle.
When the plant operates, under wind pressure the rotors acquire rotational motion. The rotors mounted in one row acquire rotational motion in one direction, while the rotors mounted in another row acquire rotational motion in opposite direction. Turning moment of the horizontally arranged rotors transmits through the bevel-gears 69 to the vertical shaft on which the vertical rotors are arranged. Since the vertical shafts are connected by the gears 71 , total turning moment is transmitted to the gear-box 73 through the coupling 63 . Then, the total turning moment is transmitted to the driven device through the gears 75 .
FIGS. 3 , 4 and 7 show another embodiment of the wind power plant. This embodiment distinguishes from the embodiment shown in FIGS. 1 and 2 in that the supporting structure 21 is fixedly secured to the foundation and is immovable. The carrying construction 23 is rotatable around the vertical axis 25 and about the immovable supporting structure 21 . This is provided by the round bar 27 fixed in the carrying construction 23 . The rotation of the carrying construction can be accomplished by any known method utilized for Horizontal Axis Wind Turbines.
The reference numerals on all figures are the same as on FIGS. 1 , 2 and 7 for the same elements.
The embodiments shown in FIGS. 1–4 and 7 may include more than one supporting structure. The number of supporting structures depends on the size “L” of the carrying construction. When the size “L” increases, the number of the supporting structures increases too. If three supporting structures are needed, one of them is positioned on the vertical axis 25 , and two supplementary ones are positioned symmetrically to the vertical axis 25 , and so on. The supplementary supporting structures are fixedly secured to the carrying construction and are installed on turning elements.
FIGS. 5 and 6 show another embodiment of the wind power plant. This embodiment has only a single rotor 45 and is therefore the simplest embodiment. The rotor 45 has a horizontal axis of rotation 47 . The supporting structure 21 is fixedly secured on the foundation 29 and is immovable. The carrying construction 23 is rotatable around the vertical axis 25 and about the immovable supporting structure. This is provided by the round bar 27 fixed in the supporting structure. The rotation of the carrying construction can be accomplished by any known method utilizing for Horizontal Axis Wind Turbines.
The rotor 45 is positioned on the carrying construction 23 and has at least two blades 53 arranged along the axis of rotation 47 . The rotor 45 has a shaft 55 , which rotates in the bearings 57 placed in the arms 61 . The arms are fixed to the carrying construction. The shaft 55 is connected by a mechanical transmission consisting of a belt drive 89 to the input shaft of the gear-box 73 . The output shaft of the gear-box is connected by the coupling 63 to the driven device 77 (a generator or a pump).
The rotor 45 is positioned along the border 79 of the carrying construction. The rotor is arranged so that less than half of the rotor's diameter protrudes out of the border of the carrying construction.
The transverse section of the carrying construction may have a special shape. This section may be shaped by a first straight line 83 arranged nearest to said rotor, and two other straight lines 85 and 87 adjoining said first straight line at an acute included angle.
In all cases, if one rotor is mounted on the carrying construction, it is arranged along one border of the carrying construction, and if two or more rotors are mounted on the carrying construction, the may be arranged both in one row along one border and in two rows along two borders.
The rotors can be mounted either on the side of the carrying construction opposed to the wind pressure, or on the side which is under the wind pressure.
When the wind power plant contains many rotors, several driven devices may be mounted on the carrying construction. In this case, each driven device will be powered by a separate group of rotors.
Mechanical transmissions used for transmitting power from rotors to driven devices can be different. The mechanical transmissions mentioned above are used as an example only.
FIG. 8 shows another embodiment of the wind power plant. In this embodiment the supporting structure 21 is not fixedly secured to the foundation 29 . The carrying construction 23 is fixedly secured to the supporting structure and is rotatable around the vertical axis 25 jointly with the supporting structure. In this embodiment two or four rotors 45 with horizontal axes of rotation are positioned on the carrying construction 23 .
FIG. 9 shows another embodiment of the wind power plant. In this embodiment the supporting structure 21 is not fixedly secured to the foundation 29 . The carrying construction 23 is fixedly secured to the supporting structure and is rotatable around the vertical axis 25 jointly with the supporting structure. In this embodiment two or four rotors 45 with horizontal and one or two rotors 49 with vertical axes of rotation are positioned on the carrying construction.
FIG. 10 shows another embodiment of the wind power plant. In this embodiment the supporting structure 21 is not fixedly secured to the foundation 29 . The carrying construction 23 is fixedly secured to the supporting structure and is rotatable around the vertical axis 25 jointly with the supporting structure. In this embodiment two rotors 45 with horizontal and two rotors 52 with inclined axes of rotation are positioned on the carrying construction.
FIG. 11 shows another embodiment of the wind power plant. In this embodiment the supporting structure 21 is not fixedly secured to the foundation 29 . The carrying construction 23 is fixedly secured to the supporting structure and is rotatable around the vertical axis 25 jointly with the supporting structure. In this embodiment two rotors 45 with horizontal, two rotors 52 with inclined, and one or two rotors 49 with vertical axes of rotation are positioned on the carrying construction.
FIG. 12 shows another embodiment of the wind power plant. In this embodiment the supporting structure 21 is into fixedly secured to the foundation 29 . The carrying construction 23 is fixedly secured to the supporting structure and is rotatable around the vertical axis 25 jointly with the supporting structure. The carrying construction is made as a pillar. The transverse section of the pillar may have a special shape in the places where the rotors are located. This section may be shaped by a first straight line 83 arranged nearest to said rotors, and two other straight lines 85 and 87 adjoining said first straight line at an acute included angle. In this embodiment one or more rotors 49 with vertical axes of rotation are positioned on the carrying construction.
FIG. 13 shows another embodiment of the wind power plant. In this embodiment the supporting structure 21 is not fixedly secured to the foundation 29 . The carrying construction 23 is fixedly secured to the supporting structure and is rotatable around the vertical axis 25 jointly with the supporting structure. In this embodiment four rotors 52 with inclined axes of rotation are positioned on the carrying construction.
FIG. 14 shows another embodiment of the wind power plant. In this embodiment the supporting structure 21 is not fixedly secured to the foundation 29 . The carrying construction 23 is fixedly secured to the supporting structure and is rotatable around the vertical axis 25 jointly with the supporting structure. In this embodiment two rotors 52 with inclined axes and one or two rotors 49 with vertical axes of rotation are positioned on the carrying construction.
FIG. 15 shows another embodiment of the wind power plant. In this embodiment the supporting structure 21 is fixedly secured to the foundation 29 and is immovable. The carrying construction 23 is rotatable around the vertical axis 25 and about the immovable supporting structure. In this embodiment two or four rotors 45 with horizontal axes of rotation are positioned on the carrying construction.
FIG. 16 shows another embodiment of the wind power plant. In this embodiment the supporting structure 21 is fixedly secured to the foundation 29 and is immovable. The carrying construction 23 is rotatable around the vertical axis 25 and about the immovable supporting structure. In this embodiment two rotors 52 with inclined and one or two rotors 49 with vertical axes of rotation are positioned on the carrying construction.
FIG. 17 shows another embodiment of the wind power plant. In this embodiment the supporting structure 21 is fixedly secured to the foundation 29 and is immovable. The carrying construction 23 is rotatable around the vertical axis 25 and about the immovable supporting structure. In this embodiment four rotors 52 with inclined axes of rotation are positioned on the carrying construction.
FIG. 18 shows another embodiment of the wind power plant. There are three supporting structures in this embodiment. The carrying construction 23 ( p and b ) is fixedly secured to the supporting structures and has a vertical axis 25 . The carrying construction is rotatable around the vertical axis 25 jointly with the supporting structures. One supporting structure 21 is installed on the foundation 29 at the vertical axis 25 , and two supplementary supporting structures 22 are symmetrized to the vertical axis 25 . All supporting structures are installed on turning elements 31 . The carrying construction consist of three pillars 23 ( p ) and four horizontal beams 23 ( b ). In this embodiment a large number of rotors 45 with horizontal axes of rotation is positioned on the beams. On each beam the rotors are positioned in two rows.
This embodiment allows for the creation of high power wind plants which can produce energy both under high and under low wind speeds.
FIG. 19 shows another embodiment of the wind power plant. There are three supporting structures in this embodiment. One supporting structure 21 is installed on the foundation 29 , fixedly secured to it, and is immovable. Two supplementary supporting structures 22 are symmetrized to the supporting structure 21 and are installed on the turning elements 31 . The carrying construction 23 ( p and b ) is fixedly secured to supplementary supporting structures 22 only and has a vertical axis 25 . The carrying construction is rotatable around the vertical axis 25 jointly with the supplementary supporting structures. The carrying construction consist of two pillars 23 ( p ) and the horizontal beam 23 ( b ). In this embodiment a large number of rotors 45 with horizontal axes of rotation is positioned on the beam. The rotors are positioned in two rows.
This embodiment allows for the creation of high power wind plants which can produce energy both under high and under low wind speeds.
FIGS. 18 and 19 show embodiments with two supplementary supporting structures. The number of supplementary supporting structures depends on the size “L” of the carrying construction. When the size “L” is greater, the number of supplementary supporting structures is also greater.
From the description above principal advantages of the present invention become evident. The wind power plant of the present invention can produce useful energy both under high and under low wind speeds and this energy will be cheaper than energy produced known wind turbines. That is why it will find a great circulation.
The scope of the invention should be determined by the appended claims and their legal equivalents, rather than by the examples given.
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A wind power plant includes four main elements: a foundation ( 29 ), at least one supporting structure ( 21 ), a carrying construction ( 23 ) having a vertical axis ( 25 ) and being rotatable around the vertical axis, and at least one rotor ( 45 ), ( 49 ), ( 52 ) positioned on the carrying construction. The rotors can have horizontal, vertical, and inclined axes of rotation in different combinations. Each rotor has at least two blades ( 53 ) arranged along its axis of rotation. Since the rotors used in the invention have a small diameter, the wind power plant can produce energy under high and low wind speeds, consequently producing more energy per year than known wind turbines. Also, because the rotors have rectilinear blades for their manufacture expensive composite materials and complicated expensive equipment are not required. For these reasons the wind power plant of this invention will produce energy at lower cost.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the use of selected hydrazidothioate compounds as load-carrying additives for functional fluids such as lubricants and hydraulic fluids.
2. Description of the Prior Art
The employment of chemical additives in lubricants, hydraulic oils and similar functional fluids to improve the overall load-carrying characteristics of the fluid is well known. Probably, the most commonly employed load-carrying additives are the zinc dialkyl and diaryl dithiophosphates. However, for many applications, it is necessary to employ ashless formulations (i.e. formulations that leave substantially no ash residue upon evaporation or combustion). In such instances, the above-mentioned zinc-containing compounds are not satisfactory.
Many load-carrying additives have, alternatively, been found which have this desired ashless characteristic. However, there is still a need in the art to find more suitable ashless additives. To meet this need is a primary object of the present invention.
The hydrazidothioates used in the present invention have been described in the prior art. See articles by Autenrieth and Meyer, Ber. 58, 848 (1925) and Klement and Knollmueller, Chem. Ber. 93, 1088 (1960). However, neither of these prior art references teach or suggest the present inventive use.
BRIEF SUMMARY OF THE INVENTION
The present invention, therefore, is directed to the use of selected hydrazidothioate compounds as additives for functional fluids, said hydrazide compounds having the formula: ##STR3## wherein R 1 is a --NHNH 2 group or a ##STR4##
These additives improve the load-carrying characteristics of the functional fluids, while being ashless in nature.
DETAILED DESCRIPTION
The two selected hydrazidothioates of the present invention, namely O-phenyl phosphorodihydrazidothioate and O,O,diphenyl phosphorohydrazidothioate, may be made according to methods described by Klement and Knollmueller in Chem. Ber. 93, 1088 (1960). Specifically, these two additive compounds may be made the reaction of the hydrazine hydrate with either phenyl phosphorodichloridothioate or O,O-diphenyl phosphorochloridothioate. See Examples 1 and 2, below. These two particular hydrazidothioate compounds may, of course, by synthesized by other conventional methods and the present invention is not intended to be limited to any particular method of making the compound. Regardless of the method of synthesis, the desired compound may be recovered from the reaction mixture by any conventional recovery method including filtration, extraction, and recrystallization.
As previously indicated, the compounds of the present invention are substantially ashless in nature. For purposes of this invention, an ashless additive is one which shows substantially no ash when tested according to the procedure set forth in ANSI/ASTM D482-74.
It is generally considered by those skilled in this art that load-carrying additives may be divided into two classes, namely antiwear and extreme pressure additives. When two lubricated moving surfaces are lightly loaded against each other, they are separated by an elastohydrodynamic oil film; as the load increases so the oil film thickness decreases. When the oil thickness approaches the dimensions of the surface roughness, it will be penetrated by surface asperities. It is in this region that antiwear additives function by improving the oil film strength and reducing intermetallic contact.
As the load is increased further, the bulk oil film collapses and mere antiwear additives are no longer sufficient to protect the surface. In this latter region, extreme pressure (EP) additives function by reacting with the metal surface to form a compound which prevents or delays welding of the metal surfaces.
For purposes of this invention, the relative antiwear characteristics of functional fluids containing additives are determined by the test procedure set forth in ANSI/ASTM D-2276-67 (Reapproved 1977) -WEAR PREVENTIVE CHARACTERISTICS OF LUBRICATING GREASE (FOUR-BALL METHOD). Still further, for purposes of this invention, the extreme pressure properties of functional fluids containing additives are determined by the test procedure set forth in ANSI/ASTM D-2783-71 (Reapproved 1976) - MEASUREMENT OF EXTREME-PRESSURE PROPERTIES OF LUBRICATING FLUIDS (FOUR-BALL METHOD).
As functional fluid additives, the present compounds normally comprise a minor proportion by weight of the total functional fluid, with a base stock fluid normally comprising a major proportion by weight of total functional fluid. Preferably, the instant additives comprise from about 0.01% to about 10%, more preferably, from about 0.1% to about 5% by weight of the total functional fluid. These weight precents are based on the filtered functional fluid in the absence of any diluents or solvents.
Any conventional method of formulating functional fluids to employ the present additives may be used and it is not intended to limit this invention to any particular method of formulation. The additives of the present invention are particularly suitable for incorporating in functional fluids such as lubricating oil compositions and hydraulic fluid compositions.
Lubricating oil compositions include crankcase lubricating oils for spark-ignited and compression-ignited internal combustion engines, such as automobile and truck engines, marine and railroad diesel engines, and the like. Automatic transmission fluids, transaxle lubricants, gear lubricants, metal-working lubricants and other lubricating oil and grease compositions may also benefit from the incorporation therein of the additive compositions of this invention.
Hydraulic composition fluids contemplated by the present invention include hydraulic brake fluids, hydraulic steering fluids, fluids used in hydraulic lifts and jacks. Also included in the scope of this invention are hydraulic fluids used in hydraulic systems such as employed in heavy equipment and transportation vehicles including highway and construction equipment, railways, planes and aquatic vehicles.
The base fluids of such lubricating oil compositions and hydraulic fluid compositions may be composed of either natural or synthetic lubricating oils or mixtures thereof. In particular, natural lubricating oils contemplated for this invention include animal oils and vegetable oils (e.g. castor oil, lard oil) as well as mineral lubricating oils such as liquid petroleum oils and solvent-treated or acid-treated mineral lubricating oils of the paraffinic, naphthenic or mixed paraffinic-naphthenic types. Oils of lubricating viscosity derived from coal or shale are also useful base oils. Synthetic lubricating oils include hydrocarbon oils and halo-substituted hydrocarbon oils such as polymerized and interpolymerized olefins (e.g., polybutylenes, polypropylenes, propylene-isobutylene copolymers, chlorinated polybutylenes); poly(1-hexanes), poly(1-octanes), poly(1-decene), and mixtures thereof; alkylbenzenes (e.g. dodecylbenzenes, tetradecylbenzenes, dinonylbenzenes, di-(2-ethylhexyl)-benzenes), polyphenyls (e.g. biphenyls, terphenyls, alkylated polyphenyls; alkylated diphenyl ethers and alkylated diphenyl sulfides and the derivatives, analogs and homologs thereof and the like.
Alkylene oxide homopolymers and interpolymers and derivatives thereof where some of the terminal hydroxyl groups may have been modified by esterification, etherification, constitute another class of known synthetic lubricating oils. These are exemplified by the oils prepared through polymerization of ethylene oxide or propylene oxide, the alkyl and aryl ethers of these polyoxyalkylene polymers (e.g., diphenyl ether of polyethylene glycol having a molecular weight of 500-1,000 diethyl ether of polypropylene glycol having a molecular weight of 1,000-1,500) or mono- and polycarboxylic esters of said polyethylene glycol, for example, the acetic acid esters, mixed C 3 -C 8 fatty acid esters, or the C 13 Oxo acid diester of tetraethylene glycol.
Another suitable class of synthetic lubricating oils comprises the esters of dicarboxylic acids (e.g., phthalic acid, succinic acid, alkyl succinic acids, alkenyl succinic acids, maleic acid, azelaic acid, suberic acid, sebacic acid, fumaric acid, adipic acid, linoleic acid dimer, malonic acid, alkyl malonic acids, alkenyl malonic acids) with a variety of alcohols (e.g. butyl alcohol, hexyl alcohol, dodecyl alcohol, 2-ethylhexyl alcohol, ethylene glycol, diethylene glycol monoether, propylene glycol). Specific examples of these esters include dibutyl adipate, di(2-ethylhexyl)sebacate, di-n-hexyl fumarate, dioctyl sebacate, diisooctyl azelate, diiodecyl azelate, dioctyl phthalate, didecyl phthalate, dieicosyl sebacate, the 2-ethylhexyl diester of linoleic acid dimer, the complex ester formed by reacting one mole of sebacic acid with two moles of tetraethylene glycol and two moles of 2-ethylhexanoic acid and the like.
Esters useful as synthetic oils also include those made from C 5 to C 12 monocarboxylic acids and polyols and polyol ethers such as neopentyl glycol, trimethyl propane, pentaerythritol, dipentaerythritol, tripentaerythritol, and the like.
Silicon-based oils such as the polyalkyl-, polyaryl-, polyalkoxyl-, or polyaryloxy- siloxane oils and silicate oils comprise another useful class of synthetic lubricants (e.g., tetraethyl silicate, tetraisopropyl silicate, tetra-(2-ethylhexyl)silicate, tetra-(4-methylhexyl)silicate, tetra-(p-tert-butylphenyl)silicate, hexyl-(4-methyl-2-pentoxyl)disiloxane, poly(methyl) siloxanes, poly(methyl-phenyl)siloxanes). Other synthetic lubricating oils include liquid esters of phosphorus-containing acids (e.g., tricresyl phosphate, trioctyl phosphate, diethyl ester of decane phosphonic acid), polymeric tetrahydrofurans and the like.
Unrefined, refined and rerefined oils, either natural or synthetic (as well as mixtures of two or more of any of these) of the type disclosed hereinabove may be used as the base stock of the present invention. Unrefined oils are those obtained directly from a natural or synthetic source without further purification treatment. For example, a shale oil obtained directly from retorting operations, a petroleum oil obtained directly from primary distillation or ester oil obtained directly from an esterification process and used without further treatment would be an unrefined oil. Refined oils are similar to the unrefined oils except they have been further treated in one or more purification steps to improve one or more properties. Many such purification techniques are known to those of skill in the art such as solvent extraction, secondary distillation, acid or base extraction, filtration, percolation. Rerefined oils are obtained by processes, similar to those used to obtain refined oils, applied to refined oils which have been already used in service. Such rerefined oils are also known as reclaimed or reprocessed oils and often are additionally processed by techniques directed to removal of spent additives and oil breakdown products.
The compounds of Formula I of this invention may be used alone or in combination with other lubricant additives such as detergents, dispersants, pour-point depressing agents, antifoam agents, viscosity modifiers, other extreme pressure load-bearing agents, corrosion inhibitors, antiwear agents, antioxidants and the like.
These additional additives are well known in the art and a brief survey of conventional additives for lubricating compositions is contained in the publications LUBRICANT ADDITIVES, C. V., Smalheer and R. Kennedy Smith, published by Lezius-Hiles Co., Cleveland Ohio, 1967, and LUBRICANT ADDITIVES, M. W. Ranney, published by Noves Data Corp., Park Ridge, N.J., 1973, which are herein incorporated by reference in their entirety.
The ash-containing detergents are well known neutral and basic alkali or alkaline earth metal salts of sulfonic acids, carboxylic acids or organophosphorus-containing acids. These phosphorus-containing acids are characterized by at least one direct carbon-to-phosphorus linkage, and can be prepared by treating an olefin polymer, i.e., polyisobutylene, with a phosphorizing agent such as phosphorus trichloride, phosphorus heptasulfide, phosphorus pentasulfide, phosphorous trichloride and sulfur, white phosphorus and a sulfur halide, or phosphorothioic chloride, When used as an ash-containing detergent, the most commonly used salts of these acids are the sodium, potassium, lithium, calcium, magnesium, strontium, and barium salts. The calcium and barium salts are used more extensively than the others. The "basic salts" are those metal salts known in the art wherein the metal is present in a stoichiometrically larger amount than that necessary to neutralize the acid. The calcium and the barium overbased petrosulfonic acids are typical examples of such basic salts. The ashless dispersants are also a well known class of materials used as additives for lubricating oils and fuels. They are particularly effective as dispersants at lower temperatures. The hydrocarbon-substituted succinic acids and their derivatives can be used as stabilizing agents in the preparation of the lubricant compositions of this invention and are representative of the dispersants. These dispersants include products obtained by the reaction of the C 30 or greater hydrocarbon-substituted succinic acid compounds and alkylene polyamines or polyhydric alcohols, which can be further post-treated with materials such as boric acids or metal compounds.
Pour-point depressing agents are illustrated by the polymers of ethylene, propylene, isobutylene, and poly(alkylmethacrylates). Anti-foam agents include polymeric alkyl siloxanes, poly-(alkyl methacrylates), copolymers of diacetone acrylamide and alkyl acrylates or methacrylates, and the condensation products of alkyl phenol with formaldehyde and an amine. Viscosity index improvers include, polymerized and copolymerized alkyl methacrylates and polyisobutylenes.
Other extreme pressure agents, corrosion-inhibiting agents, and oxidation-inhibiting agents are exemplified by chlorinated aliphatic hydrocarbons, such as chlorinated wax; organic sulfides and polysulfides; such as benzyl disulfide, bis-(chlorobenzyl)-disulfide, dibutyl tetrasulfide, sulfurized sperm oil, sulfurized methyl ester of oleic acid, sulfurized alkyl phenol, sulfurized dipentene, sulfurized terpene, and sulfurized Diels-Alder adducts; phosphosulfurized hydrocarbons, such as the reaction product of phosphorus sulfide with terpentine or methyl oleate; phosphorus esters such as the dihydrocarbon and trihydrocarbon phosphites, i.e., dibutyl phosphite, diheptyl phosphite, dicyclohexyl phosphite, pentylphenyl phosphite, dipentyl phenyl phosphite, tridecyl phosphite, distearyl phosphite, and polypropylene substituted phenyl phosphite; metal thiocarbamates, such as zinc dioctyldithiocarbamate and barium heptylphenol dithiodicarbonate; Group II metal salts of phosphorodithioic acids, such as zinc dicyclohexyl phosphorodithioate, and the zinc salt of a phosphorodithioic acid.
The following examples are provided to further illustrate the present invention. All parts and proportions, unless otherwise explicity indicated, are by weight.
EXAMPLE I
Preparation of O-Phenyl Phosphorodihydrazidothioate
Phenyl phosphorodichloroidothioate, C 6 H 5 OP(S)Cl 2 , (100 g, 0.44 mole) was added during 2.5 hours to hydrazine hydrate (225 ml of 60% solution ≅141 g N 2 H 4 ) stirred at 0° C. After further reaction for one hour, the mixture was filtered and the precipitate was collected, washed with 300 ml water and dried. Recrystallization from 2B ethanol (200 ml) gave 79 g of white crystals (82% yield) melting at 94°-95° C. (lit. m.p. =92°-95° C.).
EXAMPLE II
Preparation of O,O-Diphenyl Phosphorohydrazidothioate
O,O-Diphenyl phosphorochloridothioate, (PhO) 2 P(S)Cl, (38 g, 0.13 mole) was added slowly to hydrazine hydrate, (25 g of 60% solution ≅0.47 mole hydrazine) at 65°-75° C. The mixture was allowed to cool slowly and the solid product was then recovered by filtration, washed with water and dried. Recrystallization from benzene/petroleum ether (1:1) gave 30.5 g product (84% yield) melting at 59°-61° C.
EXAMPLES III-XII
The additive compounds made in Examples 1 and 2 were formulated with various commercially available base fluids, were tested in a 4-ball testers according to test procedures set forth in ANSI/ASTM D-2267-67 and ANSI/ASTM D-2783-71 to determine the antiwear and extreme pressure characteristics, respectively, of the fluids.
Two grams of each additive compound were mixed with 196 grams of a base fluid and 2 grams of an antioxidant, phenyl alpha naphthylamine, at room temperature. The mixture was then heated and stirred (e.g. at 100° F. to 250° F.) to dissolve the additive and antioxidant. The resulting solution was filtered to give a clear homogeneous fluid. After a wait of about 24 hours to ensure solubility, the solutions were tested in the 4-ball testers. The antiwear tests were conducted at 40 kg load weight, 1800 rpm, and 167° F. The results of these tests are given in Tables I and II.
TABLE I______________________________________FOUR-BALL ANTIWEAR TEST LOAD- AVERAGE CARRYING SCAREX. ADDITIVE BASE FLUID DIAMETER______________________________________3 none POLY-G WI-625' 0.444 O-phenyl- POLY-G WI-625' 0.435 O,O-diphenyl- POLY-G WI-625' 0.346 none MONOPLEX DOS.sup.2 1.817 O,O-diphenyl- MONOPLEX DOS.sup.2 0.48______________________________________
TABLE II__________________________________________________________________________FOUR-BALL EXTREME PRESSURE TEST LOAD LAST LOAD-CARRYING WEAR NON-SEIZURE WELDEXAMPLE ADDITIVE BASE FLUID INDEX LOAD LOAD__________________________________________________________________________ 8 none POLY-G WI-625.sup.1 22 50 126 9 O-phenyl- POLY-G WI-625.sup.1 46 80 25010 O,O-diphenyl- POLY-G WI-625.sup.1 32 63 20011 none MONOPLEX DOS.sup.2 17 40 12612 O,O-diphenyl- MONOPLEX DOS.sup.2 40 100 160__________________________________________________________________________ .sup.1 POLYG WI625 is a monobutylether of approximately 1800 molecular weight polypropylene glycol and is commercially available from the Olin Corporation. .sup.2 MONOPLEX DOS is a diiso octyl sebacate and is commercially available from Rohm & Hass Company.
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Disclosed is the use of selected hydrazidothioates as ashless load-carrying additives for functional fluids. These hydrazidothioates have the formula: ##STR1## with R 1 being either -NHNH 2 or ##STR2## group.
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BACKGROUND
[0001] 1. Field of the Disclosure
[0002] This application generally relates to palletizers, such as for corrugated bundles, and related matters.
[0003] 2. Background of the Disclosure
[0004] Manufacturing operations often use conveyors to move products as they are produced, and after they are produced, onto a device where finished products are bundled and stacked onto a pallet. The latter type of device is sometimes called a “palletizer”.
[0005] It sometimes occurs that stacking finished products involves a number of operations, such as rotating the bundle, positioning the bundle, and squaring its location with respect to the stack. This can mean that stacking bundles can take a relatively long time to occur, which can slow the production line, or alternatively, cause the stacking operation to produce lesser-quality stacks. This can cause difficulty when it is desired to stack bundles relatively quickly, such as when the production line is operating relatively quickly, or when a finishing device that is processing the bundles is operating relatively quickly.
[0006] It also sometimes occurs that stacking finished products involves placing the bundle onto a tier, such as organizing bundles into a pattern while they are stacked. This can occur when the bundles are placed in an arrangement other than a linear stack, such as to provide support in the event that the stack of bundles might sway or tilt. This can cause difficulty when combining tier placement and stacking, as another tier of bundles cannot generally be positioned until the stack of such tiers is “squared up” or otherwise stabilized.
[0007] Each of these examples, as well as other possible considerations, can cause difficulty in aspects of a manufacturing production system that includes an operation for relatively high-speed palletizing. This problem might be an issue when palletizing bundles for a relatively high-speed production line, or when palletizing bundles when a relatively high-speed finishing device is processing the bundles.
BRIEF SUMMARY OF THE DISCLOSURE
[0008] This application provides techniques that palletize bundles at relatively high-speed, even when the bundles are organized in tiers and stacked.
[0009] In one embodiment, a palletizer system includes tier placement elements, tier squaring elements, and tier stacking elements. For example, the tier placement elements can include robotic placement of bundles into layers or tiers, the tier squaring elements can include squaring-up elements, and the tier stacking elements can include elements for further stacking of tiers. By separating the tier placement elements from the tier squaring elements, the palletizer can operate at superior speed.
[0010] In one embodiment, a robotic controller element includes a vision system that determines a location and orientation of incoming bundles, an integrated conveyor tracking system that communicates between the robotic controller element and a movable bundle conveyor, and a robotic element that coordinates its movement with incoming bundles as they arrive on the conveyor. For example, the vision system can include a three dimensional (3D) vision system, a line scanner, a color vision system, or another system usable with relatively high-speed moving goods.
[0011] In one embodiment, the conveyor tracking system identifies the location and orientation of each incoming bundle on the conveyor, informs the robotic controller element of that location and orientation, and causes the robotic element to track its location and orientation with incoming bundles. The robotic controller element receives information with respect to the location and orientation of each incoming bundle. The robotic controller element instructs the robotic element to move in coordination with the location and orientation of the incoming bundle, instructs the robotic element with respect to where and at what orientation to pick up the bundle, and instructs the robotic element how to move the bundle to a tier-and-stacking position. For example, the robotic controller can instruct the robotic element how to pick up each bundle on the fly as the bundle moves into range on the incoming conveyor. Single layered or multilayer tiers may be formed in the tier-and stacking position.
[0012] In one embodiment, once the robotic element has picked up the bundle and placed it in a tier-and-stacking position, the bundle can be conveyed to tier squaring elements, which can operate separately from the robotic element. The tier squaring elements can square-up the tier independently of the robotic element, which allows the robotic element to begin operation with another set of bundles, without waiting for the tier squaring elements to perform any functions. Completed stacks of bundles may be formed in a stack building area. In one embodiment, two or more previously formed multi-layered tiers may be gathered together and combined into a completed stack in the stack build area.
[0013] After reading this application, those skilled in the art would recognize that techniques shown in this application are applicable to fields and information other than bundle palletizing systems, robotic systems, or vision systems. In the context of the invention, there is no particular requirement for any such limitation. Moreover, after reading this application, those skilled in the art would recognize that techniques shown in this application are applicable to methods and systems other than those involving manufacturing of physical devices such as boxes or stackable materials. For example, other manufacturing contexts can include assembly lines, chemical processes, semiconductor manufacturing, and otherwise.
[0014] While multiple embodiments are disclosed, including variations thereof, still other embodiments of the present disclosure will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments of the disclosure. As will be realized, the disclosure is capable of modifications in various obvious aspects, all without departing from the spirit and scope of the present disclosure. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive.
BRIEF DESCRIPTION OF THE FIGURES
[0015] FIG. 1 shows a conceptual drawing of a robotic controller system.
[0016] FIG. 2 shows a conceptual drawing of a palletizer.
[0017] FIG. 3-1 through 3 - 52 (collectively referred to as FIG. 3 ) show a conceptual drawing of a method of layering or tiering.
[0018] FIG. 4-1 through 4 - 2 (collectively referred to as FIG. 4 ) show a conceptual drawing of another method of layering or tiering.
[0019] FIG. 5 is a perspective view of a six-layered tier built in the tier build area using the method illustrated in the FIG. 4 .
DETAILED DESCRIPTION
[0020] Example Robotic Controller System
[0021] FIG. 1 shows a conceptual drawing of a robotic controller system.
[0022] In one embodiment, a robotic controller system 100 can include elements as shown in the figure, including at least the following: a robot 110 , a robot controller 120 , a bundle conveyor 130 , a vision system 140 , a conveyor tracking system 150 , a palletizer control system 160 , a tier build conveyor 170 , and possibly other elements.
[0023] Robotic Elements.
[0024] In one embodiment, the robot 110 can include one or more robotic arms that can grip one or more bundles and lift them from an incoming conveyor. The one or more robotic arms can each include a grabbing apparatus (not shown in FIG. 1 ), such as a fork or a friction gripper, that can seize each bundle in turn and remove that bundle from the conveyor. The one or more robotic arms can each include a lifting apparatus (not shown in FIG. 1 ), such as a hydraulic arm that can raise or lower the bundles, such as once they are gripped, and move them upward from the conveyor. The one or more robotic arms can each include a rotating or translating apparatus (not shown in FIG. 1 ) that can move the bundles from the conveyor, such as once they are lifted from the conveyor, to another location. References herein to lifting bundles are to be understood to refer to any suitable method for gripping and moving bundles. For example, in some embodiments, lifting bundles refers to sliding bundles into position, and in other contexts, lifting can refer to raising by any desired or suitable amount, including between about 0 inches and about 6 inches or higher, between about 0 inches and about 3 inches, between about 0.25 inches and 2 inches, or about 0.5 inches.
[0025] In alternative embodiments, the robot 110 can include a zero (or low) pressure accumulation conveyor, such as one or more vacuum grip elements disposed to seize bundles or sets of flat sheets, in the event that ordinary procedures for gripping and moving bundles are interrupted or slowed. For example, if bundles are stacked properly by the palletizer, but a post-palletizer finishing process is interrupted or otherwise slowed to a point that stacking is interrupted, a variable speed robot 110 can resequence the bundles in response to the interruption. In such cases, the variable speed robot 110 can include a zero (or low) pressure accumulation conveyor, or both a zero (or low) pressure accumulation conveyor and one or more robotic arms with gripping apparatus.
[0026] In one embodiment, the robot 110 can operate under the control of the robot controller 120 . The robot controller 120 can include a processor, program and data memory (such as non-transitory memory or mass storage), and instructions. The instructions can be maintained in the program and data memory and interpretable by the processor to alter the state of the robot controller 120 , to direct the robot 110 to perform one or more actions, or otherwise. For example, the robot controller 120 can include a personal computer (PC) or a programmable logic controller (PLC). The PLC or PC can be coupled to the robot 110 and be disposed to receive status information from the robot 110 , and to send control signals or other information to the robot 110 . This can have the effect of directing the robot 110 to move and to otherwise change state as directed by the robot controller 120 .
[0027] In one embodiment, the bundle conveyor 130 (herein sometimes called just a “conveyor”) includes devices and structure capable of moving bundles toward the robotic controller system 100 , such as bringing bundles in from a relatively remote area, such as another device or processing station. For example, the conveyor 130 can include a moving belt, such as a continuous belt having a top side and a bottom side, disposed in a substantially continuous loop, or a slanted pathway, such as including rollers or ball belts that allow bundles to roll or slide from a device toward the robotic controller system 100 , or otherwise. In such examples, bundles are positioned on the conveyor 130 , which moves them toward the robotic controller system 100 .
[0028] In one embodiment, the vision system 140 can include one or more devices that view bundles as they are conveyed by the conveyor 130 . For example, the vision system 130 can include an external sensor that can recognize one or more bundles as distinct objects, and can identify the relative location and the relative orientation of those bundles with respect to the robot 110 and each other. In such examples, the vision system 130 can include a three dimensional (3D) vision sensor, such as can be disposed to identify lines, occlusion, shadows, and other indicia of solid objects. This can have the effect of providing information with respect to locations of one or more bundles, and orientation of one or more bundles.
[0029] In one embodiment, the vision system 140 can operate with respect to individual bundles, or can operate with respect to pairs of bundles (such as when bundles are conveyed by the conveyor 130 in pairs), or with respect to other numbers of bundles. In alternative embodiments, the vision system 140 can operate to identify the amount and shape of spaces between bundles. This can have the effect that the robotic controller system 100 can identify the location of bundles in response to an amount of spacing, and the orientation of bundles in response to a shape of the spaces between bundles.
[0030] In one embodiment, the conveyor tracking system 150 can include one or more devices that move the robot 110 with respect to the conveyor 130 , so as to maintain the robot 110 in generally the same relative position with respect to one or more bundles. For example, as a bundle is moved by the conveyor 130 , the conveyor tracking system 150 can move the robot 110 at generally the same speed and in substantially the same direction as the bundle.
[0031] This can first have the effect that the robot 110 maintains a position that allows the robot 110 to grip and pick up the bundle from the conveyor 130 , with relatively rapid speed, without first having to position the robot 110 with respect to the bundle. This can second have the effect that the robot 110 can pick the bundle from the conveyor 130 , without having to match speed or orientation between the robot 110 and the bundle as the latter is moved on the conveyor 130 . These can have the effect of substantially reducing latency with respect to picking the bundle from the conveyor 130 , when the robot controller 120 directs the robot 110 to pick the bundle.
[0032] In one embodiment, the palletizer control system 160 can include devices and structures as described herein, such as with respect to FIG. 2 . For example, the palletizer control system 160 can include a control system disposed to cause elements of the palletizer to perform method steps or other techniques as described herein. In such examples, the palletizer control system 160 can include a processor and program and data memory, the program and data memory including instructions interpretable by the processor to direct the palletizer, its devices, or other devices, to perform method steps as described herein.
[0033] In one embodiment, the tier build conveyor 170 can include devices and structures as described herein, such as with respect to FIG. 2 . For example, the tier build conveyor 170 can include a conveyor disposed to receive bundles placed by the robot 110 , allow the robot 110 to position those bundles in tiers, and move those tiers to downstream devices and structures in the palletizer.
[0034] Example Palletizer
[0035] FIG. 2 shows a conceptual drawing of a palletizer.
[0036] In one embodiment, a palletizer can include elements as shown in the figure, including at least the following: the robot 110 , robot controller 120 , bundle conveyor 130 , vision system 140 , palletizer control system 160 , and tier build conveyor 170 , such as described above with respect to FIG. 1 . The palletizer can also include one or more of a bundle pick area 210 , a tier build area 220 , a tier squaring area 230 , a tie sheet hopper 231 , a tier center divider 232 , a tier lift element 240 , a stack build area 250 , a stack exit conveyor 251 , a bottom sheet conveyor 252 , a bottom sheet hopper 253 , and possibly other elements.
[0037] In one embodiment, as described herein, the palletizer can operate with respect to one or more incoming bundles 201 .
[0038] Palletizer Control System.
[0039] In one embodiment, the palletizer control system 160 , as described below, can identify the location and orientation of the bundles 201 as they are conveyed into the palletizer.
[0040] The palletizer control system 160 can receive the bundles 201 from the conveyor 130 , such as at the bundle pick area 210 . As the bundles 201 are moved by the conveyor 130 , the bundles 201 are identified by the vision system 140 , which can identify the location and orientation of those bundles 201 . For example, the bundle pick area 210 can include a region in which the vision system 140 operates, or in which the vision system 140 can determine the presence of bundles 201 , or in which the vision system 140 can determine the location or orientation (or both) of bundles 201 .
[0041] In one embodiment, the bundles 201 can be placed in one or more identifiable specified locations, with the effect that the vision system 140 can relatively easily identify the bundles 201 as or when they arrive in the bundle pick area 210 . This can have the effect that the bundles 201 are restricted to one of only a relatively few possible locations and orientations in the bundle pick area 210 . For a first example, the bundles 201 can arrive or be placed in a sequence of detents, trays, or other apparatus that maintains the bundles 201 in relatively well-known locations and orientations. For a second example, the bundles 201 can be spaced as they arrive, with the effect that each pair of those bundles can be relatively easily distinguished.
[0042] In a first set of such examples, the bundles 201 can arrive or be placed in such relatively few possible locations and orientations before they arrive in the bundle pick area 210 , such as while they are on the conveyor 130 . In a second set of such examples, the bundles 201 can arrive or be placed in such relatively few possible locations and orientations as (or after) they arrive in the bundle pick area 210 , such as in response to a device or structure within the bundle pick area 210 . This can have the effects that the vision system is subject to relatively fewer errors in identifying bundles 201 , or that the vision system is subject to relatively fewer errors in identifying the location and orientation of those bundles 201 .
[0043] In one embodiment, the palletizer control system 160 can pick up the bundles 201 from the conveyor 130 . For example, as described herein, the palletizer control system 160 can include one or more robotic arms (not shown) that can grip one or more bundles 201 and lift them from the conveyor 130 . The one or more robotic arms can each include a grabbing apparatus, such as a fork or a friction gripper, that can seize each bundle 201 in turn and remove that bundle 201 from the conveyor 130 . The one or more robotic arms can each include a lifting apparatus, such as a hydraulic arm that can raise or lower the bundles 201 , such as once they are gripped, and move them upward from the conveyor 130 . The one or more robotic arms can each include a rotating or translating apparatus that can move the bundles 201 from the conveyor 130 , such as once they are lifted from the conveyor 130 , to another location.
[0044] In one embodiment, the palletizer control system 160 can place the bundles 201 in the tier build area 220 . For example, the palletizer control system 160 can use the one or more robotic arms to stack the bundles 201 in one or more patterns, each pattern forming a layer or tier, such as described with respect to FIG. 3 . In some examples, the palletizer control system 160 can use the one or more robotic arms to stack the bundles 201 in parallel, such as seizing more than one such bundle 201 from the conveyor 130 and moving the more than one such bundle 201 into the layer or tier concurrently.
[0045] In a first set of alternative examples, the palletizer control system 160 can use the one or more robotic arms to stack the bundles 201 in sequence. For a first example, the robotic arms can seize one such bundle 201 at a time from the conveyor 130 and move that one such bundle 201 in its turn into the layer or tier. For a second example, the robotic arms can seize both a first and second such bundle 201 from the conveyor 130 . In such second examples, the robotic arms can seize a first bundle 201 , lift it, seize a second bundle 201 , position the first bundle 201 above the second bundle 201 , and move the first and second bundle 201 together to the layer or tier. In other examples, the robotic arms can pick up two or more bundles side-by-side, perhaps with a support such as a shelf under one more of the bundles.
[0046] In a second set of alternative examples, the palletizer control system 160 can use the one or more robotic arms to stack the bundles 201 either in parallel or sequence, depending on circumstances. For example, the palletizer control system 160 can be responsive to one or more of the following. (A) The palletizer control system 160 can decide to act in parallel or sequence in response to the space between bundles 201 . (B) The palletizer control system 160 can decide to act in parallel or sequence in response to the timing between arrival of bundles 201 . (C) The palletizer control system 160 can decide to act in parallel or sequence in response to the number of spaces for such bundles 201 available in each layer or tier. (D) The palletizer control system 160 can decide to act in parallel or sequence in response to some combination or conjunction of factors, or in response to other factors.
[0047] Layers, Tiers, and Stacks.
[0048] In one embodiment, the tier build area 220 can include a first tier conveyor that, upon completion of a stack of layers or tiers, moves the stack of layers or tiers into the tier squaring area 230 . The tier squaring area 230 can include a region that allows devices or structure to cause each stack of layers or tiers to be “squared up.” This can have the effect of causing each stack of layers or tiers to have a relatively well-ordered set of bundled, each relatively well-positioned with respect to a center of gravity, and each having a relatively smooth set of edges or sides. In such cases in which each bundle 201 includes sheets of corrugated cardboard material, or includes a stack of other relatively flat sheets of material (such as metal, plastic, or thin wood), this can have the effect of smoothing the sides of each stack to prevent excess material, ridges, or other protrusions that might cause one or more individual sheets to be damaged by other processes.
[0049] In one embodiment, the tier squaring area 230 can be coupled to a tie sheet hopper 231 . The tie sheet hopper 231 can maintain and dispense tie sheets (not shown) that can be placed under each stack before that stack is squared up and tied. This can have the effect that the bottom of each stack (such as the bottom layer or tier, or the bottom sheet) is protected against foreign object damage, protected against damage from components of one or more conveyors, or otherwise.
[0050] In one embodiment, the tier squaring area 230 can include an (optional) tier center divider 232 , or other separator devices or structures, or other collating or collecting devices or structures. This can have the effect that the tier squaring area 220 can provide separation of stacks into substacks, or collection of stacks into superstacks, some combination or conjunction thereof, or otherwise.
[0051] In one embodiment, the tier squaring area 230 can include second tier conveyor that, upon tying of a stack, can move the stack onto the stack build area 250 . The stack build area 250 can include a region that allows multiple stacks to be collected, such as for dispensing onto one or more pallets that can transport the stacks out of the production area. For example, completed stacks can be transported out of the production area and toward a loading region, where the stacks can be loaded onto transportation. Tiers can be built as part stacks, or tiers can be built and then moved or assembled into stacks.
[0052] In one embodiment, the stack build area 250 can be coupled to a stack exit conveyor 251 that can move stacks from the stack build area 250 to a location from which those stacks can be transported. For example, stacks can be transported from the stack exit conveyor 251 using one or more forklifts or other equipment.
[0053] In one embodiment, the stack build area 250 can be coupled to a bottom sheet conveyor 252 that can move bottom sheets under each stack before that stack is transported. Alternatively, in one embodiment the invention can be used to dispense pallets, and in another embodiment, pallets with bottom sheets could be dispensed. This can have the effect that the bottom of each stack (such as the bottom layer or tier, or the bottom sheet) is protected against foreign object damage, protected against damage from components of one or more conveyors, or otherwise. The bottom sheet conveyor 252 can be coupled to a bottom sheet hopper 253 that can maintain and dispense those bottom sheets, with the effect that the bottom sheet conveyor 252 can move one or more bottom sheets to the stack build area 250 before each stack is built in the stack build area 250 .
[0054] As further described with respect to FIG. 3 , the method of layering or tiering can operate in conjunction with receipt of incoming bundles 201 on the conveyor 130 , and separately from squaring-up of layers or tiers by devices or structures downstream from the conveyor 130 and the bundle pick area 210 . This has the effect that the conveyor 130 and the robot 110 can operate at a first speed, optimized to pick up bundles 201 from the conveyor 130 and place them into the tier squaring area 230 . Similarly, this has the effect that the tier squaring area 230 , and accompanying squaring-up elements, can operate at a second speed, optimized to square up layers or tiers after bundles 201 have been placed in them.
[0055] For example, if bundles 201 arrive on the conveyor 130 at a certain speed, the robot 110 can move those bundles 201 from the bundle pick area 210 at that speed (or faster). While those bundles 201 are being moved, devices in the tier squaring area 230 can be operating to square up layers or tiers. Moving bundles 201 from the bundle pick area 210 does not have to wait for the squaring-up operation. This can provide an improvement in speed over performing the operation of moving bundles 201 and squaring-up layers or tiers with the same devices or in the same area.
[0056] Example Method of Palletizing
[0057] FIG. 3-1 through 3 - 52 (collectively referred to as FIG. 3 ) show a conceptual drawing of a method of layering or tiering.
[0058] A method of using an example system is described herein. In one embodiment, the method steps can be performed in an order as described herein. However, in the context of the invention, there is no particular requirement for any such limitation. For example, the method steps can be performed in another order, in a parallel or pipelined manner, or otherwise. For another example, while this example discusses building a tier and then sending the tier to a squaring area, the bundle could be sent to a squaring unit and the tier constructed at or near the squaring unit.
[0059] In this description, where the “method” is said to arrive at a state or perform an action, that state is arrived at, or that action is performed, by one or more machines associated with performing the method. In one embodiment, the method can be performed, at least in part, by a control device separate from the machines in the production line. In alternative embodiments, the method 300 can be performed by one or more machines in a production system. For example, one or more such machines can operate in conjunction or cooperation, or each performing one or more parts of the method.
[0060] Similarly, although one or more actions can be described herein as being performed by a single device, in the context of the invention, there is no particular requirement for any such limitation. For example, the one or more devices can include a cluster of devices, not necessarily all similar, by which actions are performed. Also, while this application generally describes one or more method steps as distinct, in the context of the invention, there is no particular requirement for any such limitation. For example, the one or more method steps could include common operations, or could even include substantially the same operations.
[0061] Although the operation of the method is generally shown in FIG. 3 looking from the top down, no limitation should be read into the method or the invention due to this form of description.
[0062] Method Begins.
[0063] In one embodiment, at a state 0.0 shown in FIG. 3-1 , the robot 110 is holding an incoming bundle (a “first bundle”) 201 , while a tier 320 is conveyed away from the tier build area 220 by the first tier conveyor 170 into the tier squaring area 230 . For example, the tier 320 can include a set of arranged bundles 201 in designated locations 330 a , 330 b , 330 c , and 330 d . In such examples, the set of arranged bundles 201 can have been placed in those designated locations by the robot 110 , using one or more bundles 201 that arrived earlier.
[0064] In one embodiment, the tier squaring area 230 can be disposed, as described above, to square up the tier 320 . For example, the tier 320 can be nudged against a barrier, or a squaring element can be nudged against a portion of the tier 320 , with the effect that objects in the tier 320 can be arranged into a shape that has relatively straight sides and does not have any extrusions.
[0065] In one embodiment, the robot 110 can include a pair of grippers 310 a , 310 b , coupled to a holding device 310 c , and coupled to a lifting element 310 d . For a first example, the grippers 310 a , 310 b might operate by inserting tongs underneath the bundles 201 . For a second example, the lifting element 310 d might include a hydraulic lift coupled to a crane or other relatively static holding element.
[0066] First Bundle.
[0067] In one embodiment, at a sequence of states 0.2 through 1.0, shown in FIG. 3-2 through FIG. 3-6 , the robot 110 moves the first bundle 201 into a first position in the tier build area 220 . For example, the robot 110 can pick up or otherwise grip the first bundle 201 and move the bundle 201 to a first designated location 330 a.
[0068] In one embodiment, at a state 1.0 shown in FIG. 3-6 , the robot 110 releases the first bundle 201 at the first designated location 330 a , such as by releasing the grippers 310 a , 310 b.
[0069] In one embodiment, at a state 1.2 shown in FIG. 3-7 and a state 1.4 shown in FIG. 3-8 , the robot 110 disengages from the first bundle 201 , such as by raising itself above a highest element of the first bundle 201 .
[0070] Second Bundle.
[0071] In one embodiment, at sequence of states 1.6 through 2.4 shown in FIG. 3-9 through FIG. 3-13 , the robot 110 moves to a location and orientation of a second incoming bundle 201 .
[0072] In one embodiment, at a state 2.6 shown in FIG. 3-14 and a state 2.8 shown in FIG. 3-15 , the robot 110 grips the second incoming bundle 201 , while the tier 320 can remain stable in the tier build area 220 .
[0073] In one embodiment, at a sequence of states 3.0 through 4.0 shown in FIG. 3-16 through FIG. 3-21 , the robot 110 moves the second incoming bundle 201 into a second position in the tier build area 220 . For example, the robot 110 can pick up or otherwise grip the second bundle 201 and move the second bundle 201 to a second designated location 330 b.
[0074] In one embodiment, at a state 4.2 shown in FIG. 3-22 and a state 4.4 shown in FIG. 3-23 , the robot 110 similarly releases the second bundle 201 at the second designated location 330 b , such as by releasing the grippers 310 a , 310 b.
[0075] In one embodiment, at a state 4.6 shown in FIG. 3-24 , the robot 110 similarly disengages from the second bundle 201 , such as by raising itself above a highest element of the second bundle 201 .
[0076] Third Bundle.
[0077] In one embodiment, at a sequence of states 4.8 through 5.8 shown in FIG. 3-25 through FIG. 3-30 , the robot 110 similarly moves to a location and orientation of a third incoming bundle 201 . For example, the tier 320 can be moved by the tier build conveyer 170 while the robot 110 is moving and the third bundle 201 remains stable in the bundle pick area 210 .
[0078] In one embodiment, at a state 6.0 shown in FIG. 3-31 and a state 6.2 shown in FIG. 3-32 , the robot 110 grips the third incoming bundle 201 , while the tier 320 remains stable in the tier build area 220 .
[0079] In one embodiment, at a sequence of states 6.4 through 7.2 shown in FIG. 3-33 through 3 - 37 , the robot 110 moves the third incoming bundle 201 into a third position in the tier build area 220 . For example, the robot 110 can pick up or otherwise grip the third bundle 201 and move the third bundle 201 to a third designated location 330 c.
[0080] In one embodiment, at a state 7.2 shown in FIG. 3-37 and a state 7.4 shown in FIG. 3-38 , the robot 110 similarly releases the third bundle 201 at the third designated location 330 c , such as by releasing the grippers 310 a , 310 b.
[0081] In one embodiment, at a state 7.6 shown in FIG. 3-39 , the robot 110 similarly disengages from the third bundle 201 , such as by raising itself above a highest element of the third bundle 201 .
[0082] Fourth Bundle.
[0083] In one embodiment, at a sequence of states 7.8 through 8.6 shown in FIG. 3-40 through FIG. 3-44 , the robot 110 similarly moves to a location and orientation of a fourth incoming bundle 201 . For example, the tier 320 can remain stable in the tier build area 220 while the robot 110 is moving.
[0084] In one embodiment, at a state 8.8 shown in FIG. 3-45 and a state 9.0 shown in FIG. 3-46 , the robot 110 grips the fourth incoming bundle 201 , while the tier 320 remains stable in the tier build area 220 .
[0085] In one embodiment, at a sequence of states 9.0 through 9.8 shown in FIG. 3-46 through 3 - 50 , the robot 110 moves the fourth incoming bundle 201 into a fourth position in the tier build area 220 . For example, the robot 110 can pick up or otherwise grip the fourth bundle 201 and move the fourth bundle 201 to a fourth designated location 330 d.
[0086] In one embodiment, at a state 10.0 shown in FIG. 3-51 and a state 10.2 shown in FIG. 3-52 , the robot 110 similarly releases the fourth bundle 201 at the fourth designated location 330 c , such as by releasing the grippers 310 a , 310 b.
[0087] In one embodiment, at a state 10.2 shown in FIG. 3-52 , the robot 110 similarly disengages from the fourth bundle 201 , such as by raising itself above a highest element of the fourth bundle 201 .
[0088] Method Ends and Repeats.
[0089] In one embodiment, the method repeats so long as there are further incoming bundles 201 .
[0090] Layer Formation in the Tier Build Area.
[0091] In another embodiment, the system is configured to form bundle layers in the tier build area 220 . In this embodiment, the robot 110 forms a multi-layered tier 320 of bundles 201 by stacking two or more layers of bundles 201 on top of each other in the tier build area 220 . Once the robot 110 builds up a desired number of layers, the multi-layered tier 320 may be moved out of the tier build area 220 and into the tier squaring area 230 . In one embodiment, two or more multi-layered tier 320 of bundles 201 may be gathered together and combined into a completed stack in the stack build area 250 .
[0092] Turning now to specific methods of building a multi-layered tier 320 in the in the tier build area 220 , reference is again made to FIG. 3 . In one implementation, the robot 110 stacks bundles 201 to a desired height in a particular designated location before the robot 110 moves onto stacking in the next designated location. For example, in connection with building a two-layered tier 320 of bundles 201 in the tier build area 220 , the robot 110 may begin by stacking a first and a second bundle 201 on top of each other in the first designated location 330 a . Stacking the first and second bundle may include executing and then repeating the sequence of states 0.2 through 1.4, shown in FIG. 3-2 through FIG. 3-8 . The robot 110 then stacks a third and a fourth bundle 201 on top of each other in the second designated location 330 b by, for example, executing and then repeating the sequence of states 1.6 through 4.6 shown in FIG. 3-9 through FIG. 3-24 . Following this, the robot 110 stacks a fifth and a sixth bundle 201 on top of each other in the third designated location 330 c by, for example, executing and then repeating the sequence of states 4.8 through 7.6 shown in FIG. 3-25 through FIG. 3-39 . Here, the two-layered tier 320 of bundles 201 can be moved by the tier build conveyer 170 while the robot 110 is moving and the fifth bundle 201 remains stable in the bundle pick area 210 . Finally, the robot 110 stacks a seventh and an eighth bundle 201 on top of each other in the fourth designated location 330 d by, for example, executing and then repeating the sequence of states 7.8 through 10.2 shown in FIG. 3-40 through FIG. 3-52 .
[0093] In another implementation, the robot 110 stacks bundles 201 to a desired height in the first and second designated locations 330 a - b before the robot 110 moves onto stacking in the third and fourth designated locations 330 c - d . For example, in connection with building a two-layered tier 320 of bundles 201 in the tier build area 220 , the robot 110 may begin by placing a first bundle 201 in the first designated location 330 a and a second bundle 201 in the second designated location 330 b . Placing the first and second bundles may include executing the sequence of states 0.2 through 4.6, shown in FIG. 3-2 through FIG. 3-24 . The robot 110 then stacks a third bundle 201 on top of the first bundle 201 in the first designated area 330 a and a fourth bundle 201 on top of the second bundle 201 in the second designated area 330 b by, for example, executing a second time the sequence of states 0.2 through 4.6, shown in FIG. 3-2 through FIG. 3-24 . Following this, the robot 110 places a fifth bundle 201 in the third designated location 330 c and a sixth bundle 201 in the fourth designated location 330 d by, for example, executing the sequence of states 4.8 through 10.2, shown in FIG. 3-25 through FIG. 3-52 . Here, the two-layered tier 320 of bundles 201 can be moved by the tier build conveyer 170 while the robot 110 is moving and the fifth bundle 201 remains stable in the bundle pick area 210 . Finally, the robot 110 stacks a seventh bundle 201 on top of the fifth bundle 201 in the third designated area 330 c and an eighth bundle 201 on top of the sixth bundle 201 in the fourth designated area 330 d by, for example, executing a second time the sequence of states 4.8 through 10.2, shown in FIG. 3-25 through FIG. 3-52 .
[0094] In still another implementation, the robot 110 is configured to place bundles 201 on the far side of the tier build area 220 such that the intermediate operation of the tier build conveyer 170 moving a partially completed tier 320 may be omitted. Thus, in one respect, the robot 110 may be configured to place bundles 201 in the first designated locations 404 a - d shown in FIG. 4-1 . In another respect, the robot 110 may be configured to place bundles 102 in the second designated locations 408 a - d shown in FIG. 4-2 . As can be seen, the first designated locations 404 a - d do not overlap with or are otherwise offset from the second designated locations 408 a - d . More specifically, the second designated locations 408 a - d are shifted 90 degrees about a central axis with respect to the positions of the first designated locations 404 a - d . In one embodiment, the robot 110 builds a multi-layered tier of bundles 201 by alternating between the first designated locations 404 a - d and the second designated locations 408 a - d . For example, in connection with building a two-layered tier 320 of bundles 201 in the tier build area 220 , the robot 110 may build a first layer by placing a bundle 201 in each of the four designated locations 404 a - d shown in FIG. 4-1 . Following this, the robot 110 may build a second layer on top of the first layer by placing a bundle 201 in each of the four designated locations 408 a - d shown in FIG. 4-2 . Due to the offset between the first designated locations 404 a - d and the second designated locations 408 a - d , each bundle in the second layer is placed on a portion of more than one bundle in the first layer.
[0095] The multilayered tier formation methods are discussed in connection with two layered tiers by way of example and not limitation. It should be appreciated that the tier 320 may be built to any desired height prior to tier 320 being moved out of the tier build area 220 . Thus, in one embodiment, the tier 320 may be moved out of the tier build area 220 once the second layer is in place. In other embodiments, additional layers are added to the tier 320 before the tier is moved out of the tier build area 220 . By way illustration, FIG. 5 shows perspective view of a six-layered tier 500 built in the tier build area 220 . The six-layered tier 500 is built using the method discussed above that alternates between the designated locations 404 a - d shown in the FIG. 4-1 and the designated locations 408 a - d shown in the FIG. 4-2 . The six-layered tier 500 shown in FIG. 5 illustrates the pattern of bundles that is created by the offset between the first designated locations 404 a - d and the second designated locations 408 a - d . For example, a second layer bundle 504 is placed on top of a portion of two first layer bundles 508 . This orientation of bundles may provide stability to a multilayered tier.
[0096] While this method of operation has been primarily described with respect to bundles in the production line, in the context of the invention, there is no particular requirement for any such limitation. For example, methods of operation can be performed with respect to individual objects, or sets of objects, or other elements that might arrive and for which it is desirable to move and organize those elements.
[0097] Similarly, while this method of operation has been primarily described with respect to one robotic device and one production line, in the context of the invention, there is no particular requirement for any such limitation. For example, methods of operation can be performed with respect to multiple robotic devices, multiple production lines, multiple controllers, multiple types of layers or tiers. Moreover, methods of operation can be performed with respect to crossover between or among multiple robotic devices, multiple production lines, multiple controllers, multiple types of layers or tiers.
Alternative Embodiments
[0098] After reading this application, those skilled in the art would recognize many of the advantages of this description, and would recognize that various changes may be made in the form, construction, and arrangement of the components without departing from the scope or spirit of the subject matter or without sacrificing its advantages. Those embodiments described herein are merely explanatory and illustrative. While the present disclosure has been described with reference to various embodiments, it will be understood that these embodiments are illustrative and that the scope of the disclosure is not limited to them. Many variations, modifications, additions, and improvements are possible. More generally, embodiments in accordance with the present disclosure have been described in the context of particular embodiments. Functionality may be separated or combined in procedures differently in various embodiments of the disclosure or described with different terminology. These and other variations, modifications, additions, and improvements may fall within the scope of the disclosure as defined in the claims that follow.
[0099] Aspects of the embodiments described herein could be provided as a computer program product, such as may include a computer-readable storage medium or a non-transitory machine-readable medium maintaining instructions interpretable by a computer or other electronic device, such as to perform one or more processes. A non-transitory machine-readable medium includes any mechanism for storing information in a form (including a processing application or software) readable or interpretable by a machine (such as a computer). The non-transitory machine-readable medium may take the form of, but is not limited to, any known storage technique, including magnetic storage media, optical storage media, magneto-optical storage media; read only memory (ROM); random access memory (RAM); erasable programmable memory (including EPROM and EEPROM); flash memory; and otherwise.
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Techniques that palletize bundles at high-speed. A robotic controller includes a vision system that determines a location and orientation of incoming bundles, a tracking system that communicates between the controller and a conveyor, and a robot that coordinates its movement with the bundles. The tracking system identifies the location and orientation of each bundle, informs the controller, and causes the robot to track its location and orientation with incoming bundles. The controller receives information on the location and orientation of each bundle. The controller instructs the robot to move in coordination with each incoming bundle, instructs the robot where and at what orientation to pick up the bundle, and instructs the robot how to move the bundle to a tier-and-stacking position. The controller can instruct the robot how to pick up each bundle on the fly as the bundle moves into range on the incoming conveyor.
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CROSS REFERENCE TO RELATED APPLICATION
This is a division of application Ser. No. 267,579, filed May 21, 1981, now U.S. Pat. No. 4,405,612, which in turn is a continuation-in-part of application Ser. No. 152,751, filed May 23, 1980 abandoned.
TECHNICAL FIELD
The heparinizing of blood, especially for use in the in vitro testing of blood samples.
BACKGROUND ART
Heparin is normally provided by the pharmaceutical industry as an alkali metal (for example, primarily sodium) or alkaline earth (for example calcium) salt in view of the limited stability of the free acid form of heparin. The salts are most commonly provided for pharmaceutical use in the form of solutions. Solid heparin salts tend to be somewhat hygroscopic and gradually absorb water unless maintained in a low humidity environment. They are amorphous rather than crystalline and are available as fine powders.
Both the solution and solid forms of the heparin salts are conventionally utilized in blood-gas analyses wherein they serve as anticoagulants to maintain liquidity of the blood being tested. Blood-gas analyses are widely used in diagnostic medicine, oxygen and carbon dioxide contents of blood samples being of particular importance. From such measurements, a physician may obtain accurate oxygen level readings from which he may more accurately anticipate the patient's supplementary oxygen needs.
The measurement of arterial blood gas normally involves drawing a sample of blood into a syringe containing an anticoagulant and then injecting the blood sample into an analyzing instrument. The anticoagulant is used to maintain the liquidity of the blood sample so that the partial pressures of the blood gases are at substantially the same level as when initially drawn.
Even though the procedure seems simple and straightforward there are numerous opportunities for sources of error to be introduced. One particular source of error has been found to result from the method in which the anticoagulant is added to the drawn blood samples.
There are three primary methods for the introduction of an anticoagulant such as heparin into the blood samples. The first method involves the drawing of a quantity of heparin solution into a syringe in order to wet the interior walls. A substantial portion of the excess heparin is ejected and the blood is then drawn into the syringe from the patient. The blood when drawn mixes with the heparin solution to prevent coagulation. The error in this method results from the fact that an indeterminate amount of heparin solution remains in the syringe interior, needle hub and cannula. As a result, the drawn blood sample is diluted by an indeterminate amount of heparin solution which in most cases leads to less accurate blood gas data.
A second method involves the use of preheparinized syringes. These syringes are prepared by depositing a lyophilized heparin on the internal surface of the syringe. They have been found to vary in the location and the amount of heparin on the syringe barrel wall. Also, the deposited heparin dissolution rate into the blood is slower than optimal and is unpredictable. This slow dissolution rate combined with the variability in amount allows partial blood coagulation thereby introducing a source of error into the analysis. Because lyophilized heparin is more difficult and complex to manufacture and use than a heparin solution, these preheparinized syringes have been found to be much more costly without proportionately minimizing the amount of potential error.
A third method recently introduced comprises placing an anticoagulant tablet in the hub of the needle of the syringe used to obtain a blood sample from a patient. The blood flowing through the needle and into the syringe dissolves the tablet and the blood is heparinized. These tablets are comprised of a salt of heparin, a tablet binder and a pH controlling substance. Although the rate of dissolution of these tablets is fast compared to the heparinized syringe, the time required for disintegration is up to 20 seconds, and for complete dissolution up to two minutes. Also, the use of these tablets requires a mixing step after the blood is drawn into the syringe. The tablet binder and pH controlling substance are adjuvants requiring added cost and additional manufacturing complexities.
DISCLOSURE OF THE INVENTION
The present invention relates to microfibers of amorphous heparin salts which have average length to diameter ratios of at least 20 (and preferably at least 80), to open, nonwoven webs of the fibers, to processes for their preparation and to a method for heparinizing blood which comprises intermixing heparin salt microfibers (ordinarily a web of such fibers) with blood. The microfibers are of particular use in in vitro blood test procedures. They provide a much more rapidly dissolving heparin source which does not dilute the blood which is heparinized. They are easily and inexpensively prepared and can be conveniently quantized in individual test needles and syringes.
The process of the invention comprises expressing an aqueous heparin salt solution into a large excess of a fluid which is a nonsolvent for the heparin salt. It has in fact been discovered in connection with the present invention that when a much greater proportion of the fluid nonsolvent (a gas stream such as air or nitrogen or a liquid nonsolvent such as isopropanol) is utilized, the water can be removed very rapidly from the heparin salt solution while the latter is in rapid laminar motion and the heparin salt fibers are formed, rather than a blocky precipitate. Thus, in the case of a liquid nonsolvent, the ratio (by volume) of the nonsolvent to the aqueous heparin salt solution is 10 or greater (e.g. from 10 to 50) and is preferably 20 or more.
BRIEF DESCRIPTION OF THE DRAWINGS
A better understanding of the present invention may be obtained with reference to the drawings wherein
FIG. 1 is a schematic diagram of an apparatus for preparing a microfibrous web of the present invention;
FIG. 2 is an enlarged section through a microfibrous web of the present invention; and
FIG. 3 is a schematic diagram illustrative of an alternative apparatus for the preparation of a microfibrous web of the present invention.
In the apparatus of FIG. 1, the microfibers are formed in a stream of an inert gas. The microfiber-blowing portion of the apparatus can be a conventional structure as taught, for example, in Wente, Van A., "Superfine Thermoplastic Fibers", in Industrial Engineering Chemistry, Vol. 48, pages 1342 et seq (1956), or in Report No. 4364 of the Naval Research Laboratories, published May 25, 1954, entitled "Manufacture of Superfine Organic Fibers" by Wente, V. A.; Boone, D. C.; and Fluharty, E. L. Such a structure includes a die 10 which has a solution injection chamber 11 through which liquified fiber-forming solution is advanced; die orifices 12 arranged in line across the forward end of the die and through which the fiber-forming solution is directed; and cooperating gas orifices 13 through which a gas, typically air or nitrogen, is forced at very high velocity. The high-velocity gaseous stream draws out and attenuates the extruded fiber-forming heparin solution, whereupon the fiber-forming heparin solidifies as microfibers during travel to a collector 14. The collector 14 is typically a finely perforated screen, which in this case is in the form of a closed-loop belt, but which can take alternative forms, such as a flat screen or a drum or cylinder. Gas-withdrawal apparatus may be positioned behind the screen to assist in deposition of the microfibrous web 22 and removal of gas. It will be understood by the art that operating conditions must be controlled to avoid decomposition of the heparin.
The web, as shown in FIG. 2, can be cut or shaped into a variety of forms, e.g. plugs, discs, cubes, etc. The crossover points of the individual fibers in the webs may be partly or completely fused.
The apparatus shown in FIG. 3 forms the webs by precipitating the microfibers from solution. The apparatus includes a heparin solution injecting portion, a nonsolvent fluid circulating system and a web take-off portion. The fluid system is comprised of a collection reservoir 30 and a filament attenuation section 36. In line between the reservoir 30 and attenuation section 36 is a pump 32 and a flow meter 34 which may be used to control the flow rate of the fluid. The selection of the fluid is dependent on the environment in which the heparin is to be used. The heparin solution is injected into the fluid path at filament attenuation section 36 through injection orifice 44. The heparin solution enters injection orifice 44 from the heparin reservoir 38 after passing through control valve 40 and flow meter 42. The movement of the heparin solution may be facilitated by numerous means known to the art, e.g. a pump, air pressure, etc. As with the air-blown system, it is necessary that the fluid stream have a relative velocity greater than that of the injected stream of the heparin. The combined streams (e.g. fluid and heparin) are directed to the web take-off portion which is comprised of a movable collector 48 where the microfibers are collected in web form and the fluid returns to the fluid reservoir 30 for recycling. Screen 48 movement is facilitated by rollers 51 and 53 and motor 52. The width of the formed web 54 is controlled by the gauge bars 46. The web 54 passes under a wringer roller 50 which further aids in the removal of the fluid from web 54. Web 54 may then be directed to a drier or to further processing as desired.
DETAILED DESCRIPTION
The heparin salt webs of the invention are, as noted previously, particularly useful in and adapted for certain in vitro blood tests, e.g. in which the blood is subjected to them immediately upon being drawn from a mammalian subject in order to stabilize the blood in a liquid state suitable for testing. This stabilization reaction is commonly referred to as heparinization.
The webs are, when properly packaged and stored, stable for years under ambient conditions or longer when stored cold. At relative humidities of approximately 55 percent (at ambient temperatures, e.g. 20°-25° C.) they are still stable for several months although under very high humidity conditions they absorb an excess of moisture and deform grossly. They dissolve very rapidly in aqueous solutions, including blood, due, it appears, to the open structure and relatively high surface area of the microfibers and to the absence of any solid excipient or other additive. Thus, relatively small pledgets of heparin web (less than about one cubic centimeter) have been found to dissolve completely in about one second in water or blood.
The webs are moderately stable to cobalt irradiation and can thus be easily sterilized. They are capable of absorbing up to about three megarads while retaining about 83 percent of the USP activity and 77 percent of the anti Factor X a activity of the heparin salt starting material. The density of the individual microfibers is about 1.8 g/cc. The acidity of solutions of the heparin salt microfibers depends upon the acidity of the solutions from which they were originally prepared and the acidity of the water used to dissolve them. However, the webs do not significantly affect the pH of the blood samples which are heparinized due to the relatively small amount used and the buffering capacity of blood.
The length and diameter of the microfibers is dependent upon the process used to prepare them, for example stirring rate, means of extrusion, velocity of extrusion, the nonsolvent (if any) used and the ratio of nonsolvent to water used. Generally, the shorter fibers are less useful for many purposes because they are difficult to handle and form poorer webs and mats. Thus, the average length to diameter ratio of the fibers is preferably at least 20 and is more preferably at least about 80.
The cation in the heparin salts is generally selected from group I or group II of the Periodic Table of the Elements and is normally an alkali metal, an alkaline earth or zinc, for example lithium, sodium, potassium, magnesium, calcium or zinc. Fibers of salts of heparin and all of these cations having length to diameter ratios of at least 80 are conveniently prepared by the process of the invention.
The strength and structural integrity of the webs, their ability to be cut, punched or divided into pieces of desired shapes and weights, their open structure and high surface area render them ideally suited for rapidly heparinizing blood under controlled conditions, e.g. in the blood gas analysis test. Such pieces of the web may be placed in a syringe in any acceptable way, but are preferably inserted into the hub of a needle through which blood to be analyzed is drawn. When utilized in this way the heparin web pieces heparinize the blood drawn through the needle virtually instantaneously and essentially eliminate all presently known sources of error due to inadequate heparinization during blood gas analysis. This method is faster than any previous heparinization method, and allows immediate analysis of the blood sample drawn.
The weight of the fragment to be used in a single syringe depends upon the specific USP activity of the heparin and will be gauged to provide a desired level of USP activity, for example at least 250 USP units of anticoagulant activity. The density of the web and the size of the cut piece may be varied as desired. Typical sizes are 1.5 to 4.0 mm. in diameter and 1 to 5 mm. in thickness. Thinner discs of larger diameter of heparin web of at least 250 USP activity may be placed in the barrel of the syringe before inserting the plunger as an alternative to placing the web in the needle hub.
The procces of preparing the microfiber, which constitutes a separate aspect of the invention, comprises expressing an aqueous heparin salt solution into a large excess of a fluid which is a nonsolvent for the heparin salt. The fluid can be gas which is inert with respect to the heparin salt, such as nitrogen or air or a liquid nonsolvent for heparin salt and the process can be carried out as a batch operation or continuously. Three more specific embodiments of the process are as follows:
1. An aqueous solution of from about 40 percent to 60 percent heparin salt by weight is expressed through a small concentric orifice into a stream of dry inert gas and blown onto a collection screen. See FIG. 1.
2. An aqueous solution of from about 10 percent (w/w) to 40 percent heparin salt by weight is expressed into a rapidly stirred dry liquid nonsolvent for heparin such as methanol, ethanol, 1-propanol, isopropanol, t-butanol, acetone and the like.
3. An aqueous solution of from 10 percent to 30 percent by weight heparin salt is continuously mixed into a stream of nonsolvent liquid and the microfibers are collected on a moving screen while the nonsolvent is recirculated and excess water is removed from the solvent stream. The concentration of nonsolvent is maintained at 95 percent or higher. See FIG. 3.
When a batch process is used with a liquid nonsolvent (2 above), the concentration of the nonsolvent must be retained at greater than 90 percent by volume at all times during the process (the remainder of less than 10 percent being the aqueous solution of the heparin salt) and preferably the concentration of the liquid nonsolvent is retained at 95 percent or even better, 99 percent or more by volume. Thus, even at 90 percent of nonsolvent liquid, the resulting microfibers are short and thin. The concentration of the liquid nonsolvent is maintained at 95 percent by volume or greater in the continuous process. In both cases, the microfibers increase in length (and hence in length to diameter ratio) as the concentration of the water decreases. The preferred liquid nonsolvent is isopropanol since it produces the best microfibers.
The microfibers obtained from the foregoing processes contain some water and, where a liquid nonsolvent has been used, normally some of it as well. The combined nonsolvent and water content of the microfibers (webs) generally ranges up to 25 percent, usually 10 to 15 percent. The webs are dried by conventional methods such as vacuum oven, streams of dry gas, expressing or centrifuging off excess fluid followed by oven or gas drying, and the like to maintain flexibility and pliability. The resulting webs may then be cut, sliced, punched or divided in other conventional ways due to the inherent strength and structural integrity of the webs. More specifically, a web of the microfibers may be dried in a vacuum oven for example at about 60° C. and will ordinarily reach desirable handling characteristics after 2 to 3 hours. Such a drying cycle typically produces product having a USP LOD (loss on drying) of about 7 to 11 percent. The drying time needed to produce such a product can be reduced by varying these conditions. When heparin salt microfibers are overdried, they become flaky and fragile but will absorb moisture under controlled humidity, e.g. about 25 to 35 percent, preferably 30 to 35 percent, from the atmosphere and again become pliable.
The following examples are given for the purpose of further illustrating the invention but are not intended, in any way, to be limiting of the scope thereof. All parts are given by weight unless otherwise specifically noted.
EXAMPLE 1
A sample of 10 g. of sodium heparin (U.S.P. activity 161 units per milligram) is dissolved in 15 g. of water to provide a solution of 40 percent by weight of sodium heparin. The solution is passed through a hypodermic needle with a tip opening of 0.84 mm. (18 gauge needle) by using a syringe as the pump. The solution expressed from the needle is blown by a stream of compressed air at a pressure of about 3400 N/m 2 blown through a 6.35 mm. diameter nozzle. The resulting microfibers are further attenuated and dried by blowing a stream of warm air from a heat gun over the stream issuing from the nozzle. The sodium heparin microfibers formed are collected at a web screen consisting of a 232 cm 2 piece of standard laboratory burner gauge. 300 Mg. of the microfibers are obtained from 3 ml. of the solution (a yield of 25 percent), and the balance of the sodium heparin is collected as droplets in a pan.
A portion of the resulting web is found to dissolve instantly in water.
EXAMPLE 2
The web of material from Example 1 is evaluated as follows:
A 12 mm. diameter disc of the web weighing about 2 mg. is dropped into a small (about 0.5 ml.) quantity of rabbit blood on a watch glass and observed to dissolve immediately.
Three 13 mm. diameter discs of the web are cut and weighed by difference after being inserted into the barrel of 5 ml. plastic syringes. Human blood (1 ml.) is drawn into each of the syringes from a reference supply of blood. The web dissolves in less than one second. No clotting is observed. The pH of both the reference supply of blood and each of the heparinized samples is checked as shown in Table I below by using the pH sensor in a commercial blood gas analyzer.
TABLE I______________________________________ Weight of pH ofSample Description Heparin Disc Sample______________________________________A Reference Blood none 7.32B Sample 1 0.0021 g. 7.33C Sample 2 0.0019 g. 7.33D Sample 3 0.0017 g. 7.32______________________________________
Thus, the sodium heparin web does not significantly affect the pH of the blood sample.
EXAMPLE 3
0.8 Ml. of a 25 percent by weight aqueous solution of sodium heparin is expressed into a stirred reactor containing 50 ml. of isopropanol from a syringe through a 22 gauge needle. The resulting microfibers collect and mat around the stirring bar. The mat or web is pressed between two pieces of filter paper, placed on a vacuum filter apparatus covered with a rubber dam and dried by pulling a vacuum on the apparatus.
A portion of this web is removed and tested for solubility in water. It dissolves very rapidly.
EXAMPLE 4
A syringe with a 22 gauge needle is used to extrude 6.2 g. of a 22.5 aqueous solution of sodium heparin into a magnetically stirred reactor containing 120 ml. of anhydrous isopropanol. The mixture is poured into a homogenizer and homogenized for about 2 minutes at high speed. The mixture is transferred to the Buchner funnel of a vacuum filter apparatus, allowed to settle and a vacuum is applied. A piece of filter paper is placed on top of the sodium heparin web or mat, and a rubber dam is used over the Buchner funnel. After the web has been pulled dry under vacuum, it is placed in a vacuum drying over at 85° C. for about 18 hours. The weight of the web is 1.587 g. (1.395 g. theoretical) indicating about 15 percent solvent content.
The web is cut with a 3.8 mm. cork borer to form discs of the heparin web weighing about 2.5 mg. which dissolve very rapidly in blood or water.
EXAMPLE 5
A sample of heparin web is prepared using the method of Example 4. The web is photomicrographed and the dimensions of fibers of the web are measured. The diameter of the fibers range from 3 to 50 microns. The relative lengths of the individual fibers are measured to be at least 20 to 30 times greater than the diameter. Generally the lengths of the fibers are 80 or more times greater than the diameter.
EXAMPLE 6
A 25% aqueous solution of calcium heparin is prepared. A sample (7.2 g.) of the solution is expelled from a syringe through an 18 gauge needle into 200 ml of isopropyl alcohol. Fibers having average length to diameter ratios greater than 80 are formed, collected and dried under vacuum at 50° C. for 16 hours. The web has excellent integrity and dissolves rapidly in water.
A sample of this web is stored at 37° C. under 75% relative humidity for 20 days. The structural integrity of the web is maintained and a sample is observed to dissolve rapidly in water.
A sample of calcium heparin web is sterilized with ethylene oxide. It maintains its physical integrity, ability to disintegrate in water and anticoagulant activity. Blood gas analyses carried out on blood treated with this calcium heparin web compare favorably with those utilizing the sodium heparin webs.
EXAMPLE 7
A. Preparation of Zinc Heparin
A sample of 5 g. of calcium heparin web is dissolved in 20 ml of deionized water. To this solution is added 20 ml of an aqueous solution of 4.4 g. of zinc sulfate heptahydrate. After stirring one-half hour the solution is filtered to remove calcium sulfate. To the filtrate is added 150 ml of methanol, providing a gummy product. The solvents are removed by decantation, the gum is dissolved in 20 ml of water, filtered and reprecipitated with 180 ml of methanol. The precipitate is separated by decantation of solvents, dissolved in 20 ml of water and added to 300 ml of stirred isopropyl alcohol. Solid zinc heparin precipitates and is separated by filtration providing 4.47 g. after air drying.
B. Preparation of Zinc Heparin Web
A solution of 1 g. of zinc heparin in 4 ml of deionized water is prepared. Using a syringe fitted with an 18 gauge needle the solution is injected through a 0.8μ filter into 100 ml of rapidly stirred isopropyl alcohol. The resulting fibers, which have an average length to diameter ratio greater than 20, form a web which is separated by filtration and dried at 105° C. for one hour under vacuum. The total weight of the web is 0.81 g. of zinc heparin.
A small plug of the web is observed to dissolve very rapidly, almost instantaneously, in water.
EXAMPLE 8
A. Preparation of Magnesium Heparin
An aqueous solution of magnesium chloride (300 ml of 5% w/v) is added to a 10 g. sample of purified sodium heparin. The pH of the solution is adjusted to between 6.5 and 7.0 (6.6 measured) by the addition of 0.1N hydrochloric acid or magnesium hydroxide. Methanol (300 ml) is added and the mixture is stirred for one-half hour. Isopropyl alcohol (150 ml) is added and the mixture is stirred for one-half hour. The magnesium heparin containing-layer is separated by decantation and dissolved in 5% (w/v) aqueous magnesium chloride solution. The solution is diluted with an equal volume of isopropyl alcohol and the magnesium heparin containing-layer is separated by decantation. This layer is dissolved in 1% (w/v) aqueous magnesium chloride solution and the pH is adjusted to 6.5 to 7.0 (6.7 measured) with 0.1N hydrochloric acid. The solution is diluted with an equal volume of isopropyl alcohol and stirred. The magnesium heparin gradually separates out as a syrup.
The syrup is collected with a syringe and expelled into a swirling bath of isopropyl alcohol. A precipitate of magnesium heparin is formed which is collected on filter paper and dried under ambient conditions to provide 9.5 g. of product.
B. Preparation of Magnesium Heparin Web
Using the magnesium heparin from Step A, a 20% (w/w) solution of magnesium heparin in water is prepared. A sample (10 ml) of this solution is collected in a syringe and expelled through an 18 gauge needle into a swirling bath of isopropyl alcohol. Fibers of magnesium heparin are formed which have an average length to diameter ratio greater than 20. These fibers are collected on filter paper and dried at 60° C. for 30 minutes under vacuum. Several webs are prepared from these fibers.
EXAMPLE 9
A 20% aqueous solution of potassium heparin is prepared. 9 g. of this solution is expelled through an 18 gauge needle into 200 ml of isopropyl alcohol. Fibers having an average length to diameter ratio greater than 20 are formed, collected and dried at 50° C. under vacuum. A plug of the web disintegrates completely in water in less than 5 seconds.
EXAMPLE 10
Lithium heparin is prepared from sodium heparin by substantially the process of Example 8, but utilizying lithium chloride in place of magnesium chloride.
A 25% aqueous solution of the lithium heparin is prepared and a portion (7.2 g.) of this solution is expelled through an 18 gauge needle into 200 ml of isopropyl alcohol. Fibers having an average length to diameter ratio greater than 20 are formed, collected and dried under vacuum at 50° C. for 16 hours. A plug of the web disintegrates completely in water in less than five seconds. The fibers are firm and of excellent quality for the formation of a web.
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Microfibrous heparin salts, nonwoven webs of such fibers, a process for preparing the fibers and the use of the webs for the rapid heparinization of blood are disclosed.
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This invention is the result of a contract with the Department of Energy (Contract No. W-7405-ENG-36).
FIELD OF THE INVENTION
The present invention relates to high magnetic field processing of liquid crystalline polymers and the resultant products from such processing, i.e., liquid crystalline polymers having improved mechanical properties.
BACKGROUND OF THE INVENTION
Liquid crystalline thermosets (LCT's) have become recognized over the past few years as an important new class of materials. Numerous reports have described their synthesis and phase behavior. In particular, important effects due to the orientation of the rodlike molecules in a liquid crystalline phase have been described. It has been found that curing rates are enhanced compared to reaction in an isotropic phase, and that the glass transition of the fully cured material can be significantly higher than the final cure temperature.
For structural applications, orientation of LCT's promotes the maximization of mechanical properties. A few studies have described use of magnetic fields to orient LCT's. However, the maximum reported field strength was 13.5 T and the polymer placed in the field was typically contained in microcapillary-type tubes such that the polymer was essentially a microfiber in physical dimensions, and no measurements were made of the resultant tensile properties.
It is an object of the present invention to provide a process of processing LCT's in high magnetic fields and further to provide a process for variable control of factors such as, e.g., field strength, B-staging, time in field, temperature, and selection of catalyst to obtain a product with, e.g., a desired tensile modulus. Such a desired tensile modulus can be selected for a particular application but can exceed 5×10 5 pounds per square inch, preferably 8×10 5 pounds per square inch, and more preferably 1×10 6 pounds per square inch.
It is a further object of the invention to provide resultant products of LCT's processed in high magnetic fields, such products characterized by an enhancement of, e.g., tensile modulus, over non-magnetically processed LCT's, such enhancement on the order of at least 25 percent, preferably 50 percent and more preferably 100 percent. The resultant products can typically be characterized by tensile modulus properties exceeding 5×10 5 pounds per square inch, preferably 8×10 5 pounds per square inch, and more preferably 1×10 6 pounds per square inch.
SUMMARY OF THE INVENTION
To achieve the foregoing and other objects, and in accordance with the purposes of the present invention, as embodied and broadly described herein, the present invention provides a bulk article of a liquid crystalline thermoset material, said material processed in a high strength magnetic field whereby said material is characterized as having an enhanced tensile modulus parallel to orientation of said field of greater than about 25 percent, preferably 50 percent, and more preferably 100 percent over non-magnetically processed material.
The present invention further provides a process of forming bulk articles of oriented liquid crystalline thermoset materials, said materials characterized as having an enhanced tensile modulus parallel to orientation of said field of greater than about 25 percent, preferably 50 percent, and more preferably 100 percent over non-magnetically processed material comprising curing a liquid crystalline thermoset precursor within a high strength magnetic field of greater than about 2 Tesla.
DETAILED DESCRIPTION
The present invention is concerned with orientation of LCT's in field strengths from about 2 Tesla (T) up to 10 to 20 T or more. The resultant oriented LCT product can show enhancement of properties such as improved tensile modulus of greater than about 25 percent compared to those for unoriented LCT's, preferably greater than about 50 percent and more preferably greater than about 100 percent. The present invention is further concerned with shaped articles or bulk articles of the magnetically processed LCT's. By "bulk article" is meant an article having dimensions of generally at least about 0.125 inches in each direction, i.e., height, width and depth (x, y, and z), and more preferably having at least one dimension in excess of about one inch. Such a bulk article can be shaped in a suitable mold to yield a shaped article or machined. Orientation of the LCT material processed in accordance with the present invention is found throughout the entirety of the bulk article and not limited to orientation on only the surface of the material.
Additonally, the present invention involves variable control of LCT processing such that a desired bulk article with targeted tensile modulus properties can be achieved by control of variables such as, e.g., the strength of the magnetic field, B-staging of the polymer and the length thereof, the amount of time of the magnetic processing, the temperature during processing, and selection of the catalyst for the LCT.
The LCT can generally be of any chemical structure. Numerous LCT's are known to those of skill in the art. For example, an exemplary LCT is the diglycidyl ether of dihydroxy-alpha-methylstilbene (DGE-DHAMS) cured with the diamine, sulfanilamide (SAA). Structures for these materials are shown by the structures: ##STR1## Another suitable LCT is the diglycidyl ether of dihydroxy biphenyl (DGE-biphenyl). Other suitable LCT's can include materials such as those described in U.S. Pat. Nos. 5,114,612; 5,198,551; 5,475,133; 5,266,660; 5,266,661; 5,270,404; 5,270,405; 5,270,406; and, 5,292,831. Mixtures of different LCT's may also be employed as may mixtures of LCT's and liquid crystalline polymers (LCP's) such as Vectra® polyester, Kevlar® aromatic polyamide, and Xydar® polyester. Also, mixtures or combinations of polymer materials including at least one LCT may be employed.
The magnetic fields for processing the LCT's are high strength magnetic fields, i.e., fields generally greater than about 2 Tesla, preferably greater than about 6 Tesla, and more preferably from about 10 to 20 Tesla or greater.
The present invention is more particularly described in the following examples which are intended as illustrative only, since numerous modifications and variations will be apparent to those skilled in the art.
EXAMPLE 1
Thermosets were cured at field strengths of up to 18 Tesla to evaluate the effects of very high magnetic fields on the properties of the system.
Magnetic Field Processing: The thermoset formulation was prepared by dissolving 1 equivalent of SAA and 2 milliequivalents of an organophosphonium catalyst into 1 equivalent of DGE-DHAMS at elevated temperatures. This mixture was then poured into a mold for the magnetic field experiments. This mold consisted of a Teflon cup onto which was placed two aluminum heater blocks, with the thermoset formulation filling the space between the blocks. Temperature control was maintained with a PID controller. Magnetic field experiments were conducted at the National High Magnetic Field Laboratory using a 20 T variable field electromagnet. Curing was done in the field for 1 hr at 150° C. The sample was then removed from the mold by cutting the Teflon cup and separating the aluminum plates. The final cure was done in a conventional oven, and consisted of an additional 3 hrs at 150° C., 1 hr at 175° C., and 4 hrs at 200° C. Plaques approximately 2 inches by 1.5 inches by 0.125 inches were obtained.
Thermal Expansion: Thermal expansion measurements were performed parallel and perpendicular to the field direction using an Omnitherm TMA 1000 with a heating rate of 5° C./minute and a mass of 10 grams. Values of the coefficient of thermal expansion (CTE) reported are calculated by linear extrapolation of the displacement-temperature curve over the temperature range 30° to 60° C.
Tensile Properties: Tensile properties were measured on ASTM Type V specimens using an Instron 4483 testing machine and an MTS 632.26E extensometer. The results for this example are the average of at least three different runs of sample for each field strength.
X-ray Diffraction: X-ray diffraction was performed using a rotating anode generator and a two dimensional position sensitive detector. Calculation of the orientation parameter was done using the equation ##EQU1## where the average value of cos 2 φ is given by ##EQU2##
The DGE-DHAMS/SAA system, which is initially isotropic, forms a smectic phase upon curing at 150° C. The formation of the smectic phase is due to an increase in aspect ratio of the rodlike molecules as the reaction proceeds. Under these conditions, the smectic phase forms after approximately 20 minutes of cure, and the gel point is reached in approximately 45 minutes. Curing in the magnetic field was done for 1 hour in order to ensure that any orientation induced by the field was locked into the network structure.
Tensile properties of the final cured LCT at 0, 15, 18 T are shown in Table 1. The tensile properties of the macroscopically unoriented material are similar to those obtained with epoxies based on bisphenol-A cured under the same conditions. The unique advantages of the liquid crystalline epoxy are realized when the material is oriented in magnetic fields. Particularly noteworthy is the increase in tensile modulus. Orientation in magnetic fields leads to an increase of almost three times the modulus compared to the unoriented material. The strain at break is also significantly affected by the chain orientation. While not wishing to be bound by the present explanation, it is believed that the reduction in strain at break and the increase in the modulus are due to the decreased elasticity of chemical bonds in the direction of orientation as a result of the magnetic field, as compared to segment reorientation which dominates the stress-strain behavior in an unoriented sample. The oriented product is strengthened by locking into a more perfect or ordered grid.
Measurements of the coefficient of linear thermal expansion, shown in Table 2; also indicate a high degree of anisotropy in samples prepared in magnetic fields. Again, the CTE values of the unoriented sample are similar to those of conventional epoxy thermosets. Alignment in magnetic fields causes a significant decrease in the thermal expansion parallel to the field direction and a significant increase in the thermal expansion perpendicular to the field direction. This is also consistent with the magnetic field inducing substantial bulk orientation such that molecules are aligned parallel to the direction of the field.
In order to quantify the orientation, x-ray diffraction measurements were performed. The orientation parameter was determined by integrating the scattered intensity around the azimuthal angle φ at a given value of the scattering angle 2θ according to the equations given above. The orientation parameters calculated are 0.93 and 0.90 for 15 and 18 T, respectively, where a value of 1.0 indicates complete orientation. These two values are the same within experimental error. X-ray results confirm that the molecular axes and the smectic layer normals are aligned parallel to the field direction.
The present invention describes preliminary results on magnetic field processing of liquid crystalline thermosets. Information on the mechanical properties of liquid crystalline thermosets, both unaligned and aligned in high magnetic fields, has been evaluated. These are the highest fields used to date for alignment of liquid crystalline molecules, and the degree of order obtained is higher than previously reported. Mechanical properties show significant increases in tensile modulus, giving values much greater than can be obtained with conventional thermoset processing.
TABLE 1______________________________________Tensile Properties 0 Tesla 15 Tesla 18 Tesla______________________________________modulus (ksi) 443 1081 1174strain at break (%) 8.9 0.8 1.0stress at break (psi) 13,010 8117 9985______________________________________
TABLE 2______________________________________Coefficients of Thermal Expansion 0 Tesla 15 Tesla 18 Tesla______________________________________CTE parallel to field (μm/m/°C.) 54 4.7 4.3CTE perp. to field (μm/m/°C.) -- 99.6 111.2______________________________________
EXAMPLE 2
The following materials were used: digylcidyl ether of dihydroxy-alpha-methyl stilbene (DHAMS), sulfanilamide (SAA), various organophosphonium catalysts, and a non-liquid crystalline material, i.e., diglycidyl ether of bisphenol-A (DER 332).
The various materials were formulated and placed into the mold described in Example 1. The molds were placed into the high strength magnetic fields and respective samples cured for various periods of time of five minutes, thirty minutes and fifty-five minutes. Some samples were subjected to B-staging for forty-five minutes or ninety minutes prior to reaction in the field. The curing temperature in the field was generally 150° C.
Physical properties of the resultant shaped articles from the cured molds were measured including measurement of tensile modulus parallel to the field in kilopounds per square inch, tensile modulus perpendicular to the field in kilopounds per square inch, thermal expansion coefficient in microns per meter per °C. for both parallel and perpendicular to the direction of the field, and an x-ray order parameter as determined by wide angle x-ray scattering with -0.5 indicating the molecules were completely aligned perpendicular to the field, 0.0 indicating that the molecules were arranged randomly, and 1.0 indicating that the molecules were aligned completely parallel to the field.
TABLE 3______________________________________ Thermal ExpansionField Time B-Stage Tensile coefficient(Tesla) (minutes) (minutes) (k-lbs/sq.in.) par./perp. X-ray______________________________________ 5 5 0 472 61/63 0.081 5 5 90 570 34/71 0.392 5 55 0 401 67/64 -0.072 5 55 90 764 17/90 0.75510 30 0 466 62/6510 30 45 628 63/6410 55 0 563 37/7610 55 45 900 5/9615 5 0 407 63/64 -0.10815 5 90 725 21/7815 30 0 438 63/66 -0.25315 30 45 513 66/64 0.54515 55 0 1081 7/94 0.79915 55 45 1042 17/8415 55 90 1190 4/96 0.904______________________________________
The results of Table 3 show that various combinations of field strength, time in field, and B-staging can yield significant enhancement in tensile modulus properties of the resultant article. For example, at 5 Tesla, the length of time in the magnetic field has no appreciable effect, but with the addition of B-staging of the polymer an enhancement of tensile modulus is observed at only 5 minutes within the magnetic field with dramatically greater enhancement for 55 minutes within the magnetic field. Also, it can be seen that in the absence of B-staging, 30 minutes within a 15 Tesla field has no appreciable effect, but that 55 minutes within the same field provides a dramatic enhancement of tensile modulus. Comparison of other factors demonstates that a combination of parameters or variables can be controlled to provide a desired enhancement of tensile modulus. Thus, any particular tensile modulus desired for a particular application may be arrived in a number of ways by control and selection of the variable parameters.
TABLE 4______________________________________ Tensile Modulus kpsi!; Tensile Modulus kpsi!;Field par./perd. par./perd.Strength (Tesla) samples A samples B______________________________________ 3 744.9; 18.4/71.4 1084; 5.9/77.4 6 950.0; 6.5/74.9 1079; 5.5/75.1 9 1017; 7.6/80.0 1288; 2.8/78.212 819.7; 14.5/70.4 1058; -1.1/76.315 1081; 4.7/80.718 1174; 4.4/89.6______________________________________
The results of Table 4 show that tensile modulus can be increased up to about three times that of the same material processed in the absence of a magnetic field (tensile modulus was shown in Table 1 to be about 443 kpsi for no magnetic field processing.
TABLE 5______________________________________ Tensile Curing Modulus Transverse ModulusSample Conditions (kpsi) (kpsi)______________________________________DHAMS/SAA/ 18T/55m/0B/ 1174 543.7catalyst 1 150° C.DHAMS/SAA/ 15T/55m/0B/ 1081 --catalyst 1 150° C.High purity DHAMS/ 15T/55m/0B/ 1233 475.4SAA/catalyst 1 150° C.DHAMS/SAA/ 10T/55m/90B/ 904.1 443.9catalyst 1 150° C.DHAMS/SAA/ 10T/55m/0B/ 469.1 498.4catalyst 2 150° C.DHAMS/SAA/ 15T/5m/0B/ 693.7 484.2catalyst 2 150° C.DER 332/SAA/ 15T/55m/0B/ 475.6 --catalyst 1 180° C.______________________________________
The results of Table 5 demonstrate that transverse modulus was not affected in the magnetic processing; yet the tensile modulus is dramatically increased. Further, the results show that catalyst can be a factor in reaching a desired product. Catalyst 2 is a faster catalyst than catalyst 1 thereby promoting faster reaction of the LCT. Such a faster catalyst may not allow sufficient time for orientation of the LCT material in the magnetic field. Also, the results show that purity of the liquid crystalline precursor material can affect the resultant properties as well. Finally, the results show that a non-liquid crystalline polymer material remains essentially unaffected by processing in the magnetic field, at least with respect to tensile modulus properties.
Although the present invention has been described with reference to specific details, it is not intended that such details should be regarded as limitations upon the scope of the invention, except as and to the extent that they are included in the accompanying claims.
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A process of forming bulk articles of oriented liquid crystalline thermoset material, the material characterized as having an enhanced tensile modulus parallel to orientation of an applied magnetic field of at least 25 percent greater than said material processed in the absence of a magnetic field, by curing a liquid crystalline thermoset precursor within a high strength magnetic field of greater than about 2 Tesla, is provided, together with a resultant bulk article of a liquid crystalline thermoset material, said material processed in a high strength magnetic field whereby said material is characterized as having a tensile modulus parallel to orientation of said field of at least 25 percent greater than said material processed in the absence of a magnetic field.
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CROSS-REFERENCE TO RELATED APPLICATION(S)
The present application is a continuation-in-part of U.S. application Ser. No. 08/745,699, filed Nov. 12, 1996.
BACKGROUND OF THE INVENTION
The present invention relates to digital and print-on-demand printing systems; and more particularly, to a high-speed printer controller system that is configured to control a multitude of print engines simultaneously, and is configured to synchronize the deposition of image pixels and to “lock-step” the transport mechanisms on the multitude of print engines to a single clock source, thereby reducing beat frequency and other errors between the print engines.
An ink jet printing system is an example of a printing system that is notorious for having registration problems and beat frequency errors between various print engines (ink jet printheads) controlled by at least one printer controller. Ink jet printing is a non-impact print method which is based upon controlling the behavior of a fluid ink stream using pressure, ultrasonic vibration and electrostatic forces. A typical ink jet printhead will include a multitude of nozzle orifices, aligned in an array, for emitting a corresponding multitude of fluid ink streams, commonly referred to as an array of ink. Pressure is created by a push rod to force the ink from the ink chamber and through an array of nozzle orifices.
A high frequency ultrasonic vibration (referred to as a “modulation signal”) is applied to the push rod and, in turn, to the ink stored in an ink chamber within the ink jet printhead, to establish a standing wave pattern within the ink. To create the modulation signal, the typical ink jet print head will utilize an internal clock source which is sent to a piezoelectric crystal, typically mounted within the push rod assembly. The piezoelectric crystal will thus vibrate at the frequency of the clock source. The vibrational waves will conduct into the ink chamber, causing the standing wave pattern within the ink. This standing wave pattern in the ink causes the ink to break into individual droplets, corresponding to individual pixels of the printed image, when the ink emerges from the nozzle orifices. The resulting array of ink droplet streams is directed (typically downward) towards the substrate to receive the printed image.
A multitude of electrodes are positioned adjacent to each of the ink droplet streams, near the nozzle orifices. The electrodes, controlled by the ink jet printhead, apply a voltage to the droplets which are not intended to contact the substrate. Below the electrodes, the droplet streams pass through a high voltage field which forces the charged droplets to be deflected into a gutter and which allows the uncharged droplets to pass through the field and onto the substrate, thus forming the printed image.
The nozzle orifices are typically arranged on the ink jet printhead in a row, where each nozzle orifice corresponds to one column of image pixels on the final printed image. The printed image is formed by emitting successive horizontal lines of the ink droplets (referred to as “strokes”) applied to the continuously moving substrate (moving in the vertical direction). Each stroke forms one row of pixels on the final printed image. The electrodes are controlled for each stroke by the ink jet printhead in accordance with the bitmap data sent to the print head by the raster printer controller.
In low-speed printing operations, where the substrate is moved at low speeds under the ink jet printheads, the width of the row of nozzle orifices is not a concern. However, in high-speed printing operations, where the substrate is moved at high speeds under the ink jet printheads (i.e., to print 1000 feet per minute), the size of the row of nozzle orifices becomes a real concern because of the time it takes for the vibrational waves in the chamber to travel from the push rod to the far ends of the printhead. Accordingly, to be able to print detailed, full size images in high speed ink jet print operations, it is necessary to utilize a plurality of the ink jet print heads, where each print head is responsible to print one vertical portion or “swath” of the image. One “swath” of an image corresponds to the number of vertical columns of pixels that one ink jet printhead will be able to print. Typically, the width of each swath can range from approximately 20 to 1024 pixels (i.e., the swath would comprise 20 to 1024 columns of pixels), however the range can vary depending upon the application.
Because the physical width of the ink jet printhead exceeds the width of the swath printed by the ink jet printhead, the multiple ink jet printheads cannot be aligned side by side with respect to each other without experiencing noticeable gaps between the swaths. Therefore, to get a continuous image across the width of the entire printed page, with no noticeable gaps between the swaths, it is necessary to stagger the ink jet print heads vertically with respect to the substrate such that they do not interfere with each other. It is also necessary to simultaneously control the multiple ink jet printheads such that their respective swaths are vertically and horizontally aligned with respect to the substrate. The process of vertically and horizontally aligning these swaths on the substrate to form one image is commonly referred to as “stitching”.
Stitching the multiple ink jet swaths down to the pixel level in order to obtain sub pixel resolution is extremely challenging. Mechanical alignment is the most common method of aligning the printheads to achieve stitching of the swaths. Utilizing micrometer adjustment and measurement devices on the x and y axes, the position of the printheads can be adjusted to approach sub pixel resolution. However, such alignment is only useful for a particular ink viscosity, temperature of the environment, humidity of the environment and print speed. Once any one of these variables changes, i.e., the viscosity of the ink changes, the pixel resolution will again become misaligned. Furthermore, even if the printheads are perfectly aligned, the piezoelectric crystals in each printhead will be driven at a slightly different frequency, thus causing beat frequency drift errors between the printheads which eventually leads to very visible alignment errors between the pixels of the different swaths.
Electronic alignment methods and mechanisms, while more flexible than mechanical alignment systems, also cannot achieve sub pixel resolution because of the piezo beat frequency drift errors, which will eventually cause drift between the printheads, independent of the mechanical and/or electronic methods and systems used for stitching the swaths together.
The problem of beat frequency drift errors is not limited to ink jet engines. As will be appreciated by those of ordinary skill in the art, similar errors may occur in other types of print engines that are linked together to print upon a single substrate or web. For example, magnetographic engines utilize magnetic recording heads to create a latent magnetic image on the surface of a revolving hard metal drum, which is then exposed to magnetic toner particles and transferred/fused to paper. The modulation frequency of the magnetic recording heads is controlled by a clock source, which may be slightly different on each of the print engines. Therefore, if a plurality of the magnetographic print engines are used in series to print a single image, the slight differences in the magnetic recording heads' clock sources may cause slight (but perceptible) registration errors in the printed pixels of the image. Similar beat frequency errors may occur in LED engines, Ion deposition engines, laser engines, magnetographic, xerographic engines and the like.
Accordingly, a need exists for a system and method for simultaneously controlling the plurality of staggered ink jet printheads such that stitching between the swaths generated by the ink jet printheads can be easily accomplished electronically, regardless of the ink viscosity, print speed, temperature and humidity. Furthermore, a need exists for a system and method for synchronizing the piezo clock sources on each of the ink jet printheads to each other such that the stitching can be accomplished down to sub pixel levels without experiencing beat frequency drift errors between the pixel swaths. Furthermore, a need exists for a system and method for synchronizing clock sources controlling the deposition frequency of image pixels on print engines connected (in series, in parallel or otherwise) so as to eliminate beat frequency errors between the print engines. Finally, a need exists for a system and method for synchronizing the drive mechanisms of print engines controlled by a single controller so as to “lock-step” the transport mechanisms of the printers.
SUMMARY OF THE INVENTION
The present invention provides a system and method for simultaneously controlling a plurality of print engines connected (in series, in parallel, or otherwise) that facilitates electronic stitching between the print engines. More specifically, the present invention provides a system and method for synchronizing the pixel deposition frequencies between the various inter-connected print engines so as to eliminate beat frequency errors between the print engines. The present invention also provides a system and method for synchronizing the transport mechanisms of the inter-connected print engines so as to reduce overall errors and failures of the printing system.
In a specific embodiment, the present invention provides a system and method for simultaneously controlling a multitude of continuous-flow ink jet printheads which facilitates the electronic stitching between the ink jet printheads; and furthermore, the present invention provides a system and method for synchronizing the piezo clock sources on each of the ink jet printheads to each other such that the electronic stitching can be accomplished down to the pixel levels.
The method for synchronizing the pixel deposition frequencies between a plurality of print engines comprises the steps of: (a) coupling the plurality of print engines together with at least one printer controller, (b) embedding a first clock signal in data; (c) transmitting the data to the print engines; (d) each of the print engines receiving the data; (e) each of the print engines deriving a pixel deposition clock signal from the data received, which is directly proportional to the first clock signal; and (f) each of the print engines driving its corresponding pixel deposition mechanism with the pixel deposition clock signal. Accordingly, all of the pixel deposition clock sources will be synchronized in frequency with each other, eliminating beat frequency drift errors between the print engines. The pixel deposition mechanism, as apparent to those of ordinary skill in the art, includes the LED switching device for LED engines, the ion generating cartridge for Ion deposition engines, the magnetic recording heads for magnetographic engines, the piezoelectric crystal coupled to the ink-well push rod for ink jet printheads, and the like.
Preferably, the print engines and controller are connected together in a daisy-chain configuration and the method also includes the steps of: (i) determining the time it will take for the data to propagate to each of the print engines; and (ii) adjusting the phase of the second clock signal to reflect the propagation measurement. Accordingly, all of the pixel deposition clock signals will also be synchronized in phase as well as frequency to each other.
The above method is accomplished by operating a plurality of print engines with a high-speed raster printer controller. The type of print engine is not critical and a plurality of different print engine technologies can be used. Each print engine includes a customized communication circuit, which in the preferred embodiment is a separate circuit board, hereinafter referred to as a “target adapter board” (“TAB”). The TAB provides a direct interface between the print engine electronics and the controller. The controller and each TAB includes a serial data input port and a serial data output port. The controller is attached to the plurality of TABs in a daisy-chained ring configuration, such that the controller will transmit commands and data to the first TAB on the daisy-chain, and the commands and data will flow in the same direction along the daisy-chain to the rest of the TABs, and will eventually flow back to the controller. Furthermore, the controller is adapted to transmit rasterized bitmap image data to the TABs, and in turn to the print engines, in an on-demand manner. The daisy-chained serial communication ring configuration of the controller and the plurality of TABs is hereinafter referred to as “the ring.”
The ring configuration allows all of the TABs to see all of the data all of the time. This also provides a clean mechanism for the raster printer controller to receive status from all of the print engines with minimal cabling requirements. Furthermore, use of fiber optic links in the ring provides high bandwidth data transfer capabilities, excellent electrical isolation and immunity from excessive high voltages associated with print engine electronics.
The raster printer controller has a multiplexed command/data-stream protocol structure at its fiber optic interface in which the controller transmits a command followed by the associated data. The controller initiates all commands, and manages the allocation of fiber optic band-width to receive all print engine status. Each TAB is adapted to listen for commands addressed to it, and responds appropriately; and further, the TAB never responds unless commanded by the controller. Nevertheless, each TAB must retransmit the entire command/data-stream it receives on its fiber optic input port back to its fiber optic output port, and in turn, to the next TAB on the ring. This allows all of the TABs to see all of the controller commands and data, all of the time.
Each TAB includes a fiber optic receiver/decoder, a fiber optic encoder/transmitter, a standard discrete output bus, a standard discrete input bus, a print engine instruction register, print engine status register, a bitmap data memory storage, a stroke rate counter and associated stroke rate count preload register, a high-speed fiber optic message processing circuit, and an on-board CPU. Therefore, each TAB essentially includes all the necessary print engine components.
The CPU and message processing circuit are adapted to manage the incoming and outgoing commands, to manage the TAB's hardware, and to provide an interface to the print engine electronics. The message processing circuit monitors the fiber optic input and executes the commands transmitted by the raster printer controller if the commands are addressed to it. The message processing circuit also continuously retransmits the commands/data-stream back to the fiber optic encoder/transmitter, supports the general purpose discrete output bus and instruction register in response to the commands, reads the general purpose discrete input bus and print engine status register which can be incorporated into messages sent directly to the raster printer controller as status, and also manages the data update of the bitmap data memory storage when commanded by the raster printer controller.
The raster printer controller's multiplexed command/data protocol scheme allows the raster printer controller to transmit bitmap data to the print engines in any order and at any time, thus providing print-on-demand capabilities to the print engines; allows the controller to embed a “Print Trigger” command within the command/data stream at any time thus providing real-time print trigger generation to the print engines; and allows the controller to embed a stroke rate signal within the command/data stream indicative of the web velocity and/or acceleration.
The command/data stream is transmitted over the fiber optic ring utilizing a self-clocking data transmission code such as 8B/10B code. The fiber optic encoder on the raster printer controller embeds a clock signal into the command/data stream by encoding the raw data. This allows the fiber optic decoders on each of the TAB boards to extract the embedded digital clock signal from the encoded data and to decode the command/data stream back into its raw data.
The extracted digital clock is used by each TAB to generate the pixel deposition clock signal for driving the pixel deposition mechanism on its corresponding print engine. Because each extracted clock signal will have the exact frequency (directly proportional to the clock signal embedded by the raster printer controller), each pixel deposition clock signal generated from the external clock source will also have the exact frequency.
Preferably, the pixel deposition clock signal is generated as follows: The extracted digital clock drives a free running counter whose count output is sent to a memory device which acts as a lookup table. The lookup table includes a voltage amplitude value for every count input. The voltage amplitude values in the lookup table each correspond to a particular voltage amplitude level in one period of the pixel deposition clock signal's sinusoidal wave, square wave and the like. Thus, the memory device will output the particular voltage amplitude value from the lookup table, depending upon the count input received from the counter; therefore, for each cycle through the counter, the voltage amplitude values corresponding to one period of the pixel deposition clock signal's output will be output from the lookup table. The voltage amplitude value is sent to a digital-to-analog converter, the amplified output of this digital-analog converter is the analog clock source for the pixel deposition clock signal.
To reset the counters, the raster printer controller will broadcast a CLOCK RESET command to the first TAB on the ring. The first TAB will receive this command and restart its counter to start generating its pixel deposition clock signal. As discussed above, the first TAB will also pass this command to the next TAB on the ring; which will restart its counter in response to the command and will in turn pass the command to the next TAB on the ring. This is repeated until the command is passed back to the raster printer controller.
Because it will take time for the a CLOCK RESET command to propagate to each TAB on the fiber optic ring, the present invention includes a method to assure that all the pixel deposition clock signals are synchronized in phase as well as frequency. Thus, each counter includes a preload input coupled to a phase-shift preload register. Each phase-shift preload register will be initialized by the raster printer controller during the boot-up process to a count pre-set value which corresponds to the time it takes for the CLOCK RESET command to reach the particular TAB. Thus, even though each pixel deposition clock signal will be started at progressively different instances, each phase-shift preload register is set to a particular count value to assure that the output voltage level of the piezoelectric clock source of a given TAB upon receiving the CLOCK RESET command is at the same voltage amplitude levels of all pixel deposition clock signal started prior to the present one.
Each pixel deposition clock signal is therefore locked in both phase and frequency to each other.
In a specific embodiment of the present invention, a method for synchronizing the plurality of piezoelectric crystals on a corresponding plurality of ink jet printheads comprises the steps of: (a) coupling the plurality of printheads together with a printer controller, (b) embedding a first clock signal in data; (c) transmitting the data to the printheads; (d) each of the printheads receiving the data; (e) each of the printheads deriving a second clock signal from the data received, which is directly proportional to the first clock signal; and (e each of the printheads driving its corresponding piezoelectric crystal with the second clock signal. Accordingly, all of the piezoelectric crystal clock sources will be synchronized in frequency with each other, eliminating beat frequency drift errors between the printheads.
The method for synchronizing or “lock-stepping” a plurality of print engines comprises the steps of: (a) coupling the plurality of print engines together with at least one printer controller, (b) embedding a first clock signal in data; (c) transmitting the data to the print engines; (d) each of the print engines receiving the data; (e) each of the print engines deriving a drive clock from the data received, which is directly proportional to the first clock signal; and (f) each of the print engines driving its corresponding drive mechanism with the drive clock.
Accordingly, it is an object of the present invention to provide print system with multiple print engines which can dispatch rasterized bitmap data to the print engines in an on-demand manner; which can transmit print trigger and stroke rate information to the print engines at any time; which synchronizes the pixel deposition clock signals for each print engine to a single clock source; which synchronizes the pixel deposition clock signals for each print engine in both phase and frequency; and which provides a system which facilitates electronic stitching of the print engines down to the pixel level. These and other objects will be apparent from the following description, the accompanying drawings and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 a is a block diagram representation of the present invention, depicting a plurality of print engines coupled together in a daisy-chain ring configuration with a printer controller;
FIG. 1 b is a block diagram of a specific embodiment of the present invention, depicting a plurality of ink jet print heads arranged in a staggered array to print upon a web and controlled by a single printer controller, the ink jet printheads and the controller being coupled in a daisy-chain ring configuration;
FIG. 2 is a schematic block diagram of a print engine communication device for use with the present invention;
FIG. 3 is a schematic block diagram of a stroke machine circuit for use with the present invention;
FIG. 4 is a schematic block diagram of an alternate arrangement of the printer controllers and print engines; and
FIG. 5 is a block diagram representation of a print engine (such as an ion-deposition, LED or magnetographic print engine) for use with the present invention.
DETAILED DESCRIPTION
As shown in FIG. 1 a , at least one high speed raster printer controller 10 is used to simultaneously drive a plurality of print engines 12 a - 12 c each of which are to print portions of an image onto a substrate 14 moving through each of the print engines in the direction indicated by arrow A. In a specific embodiment, as shown in FIG. 1 b , the plurality of print engines is a plurality of ink jet printheads 12 a - 12 d each of which have a nozzle array 13 a - 13 d for ejecting strokes of ink to a substrate or web 14 moving in a vertical direction indicated by arrow A. The ink jet printheads 12 a - 12 d are positioned in a staggered formation along the web 14 and each ink jet printhead is controlled by the controller 10 to transfer a corresponding swath 16 a - 16 f of an image 18 to the web 14 .
The print engines 12 , may include an LED engine, an ion deposition engine, a xerographic engine, a magnetographic engine, a laser engine, an ink jet engine or any other type of high-speed print engine, or any combination of such engines, as is known to those of ordinary skill in the art. With each of these high speed print engines, a pixel deposition mechanism is utilized, which includes a clock input for providing a pixel deposition frequency. As shown in FIG. 5, at least with LED engines, ion deposition engines and magnetographic engines, the pixel deposition mechanism 6 , includes a source 7 of a pixel deposition clock signal for providing a deposition frequency for the mechanism 6 . The pixel deposition mechanism 6 is controlled to transfer a latent image on a rotating drum 8 . Toner particles are transferred onto the latent image by a toner supply 9 , which are then transferred onto the paper or substrate 14 in the form of the final image. Motorized drive mechanisms 11 are used to drive the paper through the printer at a controlled speed. The speed of the rotating drum 8 is synchronized with the drive mechanisms 11 , and is essentially a drive mechanism itself. In LED engines, the pixel deposition mechanism includes an array of LEDs 6 and a switching device for switching the arrays on and off for creating the latent image on a revolving charged drum 8 . In magnetographic engines, the pixel deposition mechanism is a plurality of magnetic recording heads 6 that are selectively energized to create the latent magnetic image on the surface of the revolving hard metal drum 8 . In ion deposition engines, the pixel deposition mechanism is an ion generating cartridge 6 which digitally creates the latent image on the rotating dielectric drum 8 .
The pixel deposition mechanism for ink jet print heads, discussed above in detail, includes an ink chamber having a multitude of nozzle orifices, aligned in an array, for emitting a corresponding multitude of fluid ink streams, commonly referred to as an array of ink. Pressure is created by a push rod to force the ink from the ink chamber and through an array of nozzle orifices. A piezoelectric crystal is coupled to the ink-well push rod so as to create a high frequency ultrasonic vibration to the push rod and, in turn, to the ink stored in the ink chamber. This high frequency vibration in the ink chamber causes the ink droplets to emerge from the nozzles at the same frequency.
Referring to FIGS. 1 a and 1 b , the high speed raster printer controller 10 is preferably a multi-processor system for interpreting and processing an image or images defined by a page description language and for dispatching rasterized bitmap data generated by the processing of the page description language as described, for example, in U.S. Pat. No. 5,796,930. Each print engine or printhead 12 a - 12 d is coupled to one of a plurality of print engine communication circuits, which preferably reside on individual circuit boards, hereinafter referred to as “target adapter boards” (“TAB”) 20 a - 20 d . For the purposes of this disclosure, when it is disclosed that one component is “coupled” to another component, it will mean that the one component is linked to the other component by any data link such as an electronic data link (wires or circuits), a fiber optic data link, an RF (radio frequency) data link, infrared data link, an electromagnetic data link, or any other type of data link known to one of ordinary skill in the art.
Each TAB 20 a - 20 d provides an interface between the raster printer controller 10 and the respective plurality of print engines 12 a - 12 d . Preferably each TAB includes a universal controller interface section to provide a means to communicate with the raster printer controller 10 ; and a customized print engine interface section which provides a direct interface between the print engine electronics and the raster printer controller 10 .
The raster printer controller 10 includes a serial data output port 22 and a serial data input port 24 . The output port 22 is preferably a fiber optic transmitter and the input port 24 is preferably a fiber optic receiver. Each of the TABs 20 a - 20 d also include a serial data input port 26 and a serial data output port 28 (see FIG. 2 ); where the input port 20 is preferably a fiber optic receiver and the output port is preferably a fiber optic transmitter. Therefore, both the raster printer controller 10 and the plurality of TABs 20 a - 20 d each have duplex communications via fiber optics.
As is further shown in FIGS. 1 a and 1 b , the raster printer controller 10 is coupled to the plurality of TABs 20 a - 20 d in a daisy-chain configuration; and furthermore, the last TAB 20 d on the daisy-chain is coupled again to the raster printer controller to form a daisy-chain “ring”. The raster printer controller 10 transmits a command/data stream to the first TAB 20 a on the ring over a serial data link, which is preferably a fiber optic link 30 ; the last TAB 20 d on the ring transmits command/data stream back to the raster printer controller 10 over a serial data link, which is preferably a fiber optic link 32 ; and each of the TABs 20 a - 20 c transmit command/data stream to the next TAB on the ring, over serial data links, which are preferably fiber optic links 34 a - 34 c . The data output port 22 of the raster printer controller 10 transmits coded data serially over the fiber optic link 30 . The data is encoded from raw digital data by an encoder device 35 . The raw digital data is passed over a parallel data line to the encoder device 35 from the control circuitry 37 of the raster printer controller. The data input port 24 receives the coded data back from the fiber optic link 32 . This data is then decoded back into raw digital data by a decoder device 39 . The raw digital data is then passed on to the control circuitry 37 of the raster printer controller in parallel form. The fiber optic links 30 , 32 , 34 a - 34 c provide substantial electrical isolation and immunity from excessive high voltages associated with print engine electronics and the fiber optic links are scalable, i.e., their data rates can be easily slowed down if desired.
As will be discussed in significant detail below, the a printer controller embeds a first clock signal (from a first clock source 73 ) in data and transmits the data to the fiber optic ring. Each TAB 20 a - 20 d on the fiber optic ring derives a pixel deposition clock signal 68 from the data received, which is directly proportional to the first clock signal. Finally, each of the print engines 12 a - 12 d drives its corresponding pixel deposition mechanism 6 a - 6 d with the pixel deposition clock signal 68 . Accordingly, all of the pixel deposition clock sources will be synchronized in frequency with each other, eliminating beat frequency drift errors and/or other synchronization errors between the print engines. It is within the scope of the invention that pixel deposition clock signal be used to synchronize the drive mechanisms 11 , 8 between the print engines, thereby “lock-stepping” the operations of the various print engines together.
It should be apparent to one of ordinary skill in the art, that while fiber optic links are preferred for the present embodiment of the invention, it is within the scope of the invention to utilize any other type of serial data link capable of performing applications described herein. For example, the fiber optic links could be replaced with coax or twisted pair links.
Furthermore, while the above daisy-chain ring configuration is preferred, it is within the scope of the invention to couple the controller 10 to the plurality of TABs 20 a-d in a configuration (daisy-chain or otherwise) which is not configured as a ring. For example, as shown in FIG. 4, it is within the scope of the invention to couple the printer controller 10 ′ to the plurality of print engines 12 ′ in a “star” or “spoked wheel” configuration where the controller 10 ′ will be at the “hub” and is coupled to each of the print engines 12 ′ separately with individual data links 200 . As is also shown in FIG. 4, it is also within the scope of the invention to utilize print engine communication circuits 20 ′ to interface between the controller 10 ′ and one or a plurality of print engines 12 ′ in the “star” configuration.
The preferred daisy-chained serial configuration of the raster printer controller and plurality of TABs is hereinafter referred to as “the ring.”
Each TAB is configured to transmit the entire command/data stream received on its input port 26 back to its output port 28 . Accordingly the raster printer controller 10 will transmit the command/data stream to the first TAB 20 a on the ring and the command/data stream will flow in the same direction along the daisy-chain to the rest of the TABs 20 b - 20 d , and eventually will flow from the last TAB 20 d on the ring back to the raster printer controller 10 . This configuration allows all the TABs to see all the command/data stream all of the time.
As shown in FIG. 2, each TAB 20 includes a digital decoder 36 for decoding the data stream received by the fiber optic receiver 26 into raw digital input data on the input data bus 38 , and a digital encoder 40 for transforming the raw digital output data on the output data bus 42 into an encoded data stream to be transmitted by the fiber optic transmitter 28 . Also included on each TAB is a high-speed message processing circuit 44 , coupled between the decoder 36 and encoder 40 . The high-speed message processing circuit 44 is designed to monitor the digital input data on the input data bus 38 and to execute the commands embedded in the command/data stream when the embedded TAB address field matches the TAB's internal address. The high speed message processing circuit 44 also continuously retransmits this digital input data to its fiber optic encoder 40 as digital output data on the output data bus 42 , which is in turn transmitted to the next TAB on the ring (or back to the raster printer controller if the present TAB is the last TAB on the ring) by the fiber optic transmitter 28 .
Preferably, the high-speed message processing circuit 44 is a non-intelligent device, that is, it is a “hardware” device whose internal functions are not directed by a software program. Therefore the high-speed message processing circuit is very fast and is able to handle the bandwidth requirements for the multiplexed command/data protocol structure described below. Furthermore, the high-speed message processing circuit 44 is not as susceptible to the errors and failures which may commonly occur in software controlled devices. The high-speed message processing circuit 44 may be fabricated from standard TTL devices, CMOS devices, 7400 series logic, or incorporated into single or multiple chip implementations such as programmable logic arrays (PALs), field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs) or any hardware description language (HDL) based device; and in a preferred embodiment, the high-speed message processing circuit 44 is an ASIC device.
The high-speed message processing circuit 44 is coupled to a discrete output buffer 46 and a discrete input buffer 48 via a data busses 50 , 51 , respectively. In executing commands transmitted by the raster printer controller, the high-speed message processing circuit 44 can set or reset lines on the discrete output buffer 46 and can report back to the raster printer controller messages pertaining to the status of lines on the discrete input buffer 48 . Such output discretes can include, for example, “print on-line,” “printer reset,” and “reset communications.” Such input discretes can include, for example, “engine error.” Thus, the discrete buffers provide a mechanism for handling general purpose I/O requirements of print engine.
The TAB 14 also includes a bitmap data transfer circuit 57 which includes a bitmap data memory storage buffer 52 for interfacing directly to the corresponding print engine's video data input port 54 . Therefore, the message processing circuit 44 is also designed to update the bitmap data memory storage buffer 52 when commanded by the raster printer controller 10 . This bitmap data memory storage buffer, in the preferred embodiment, is a FIFO buffer; however, the bitmap data memory storage buffer 52 may also be video memory, a single byte of memory (i.e., a register), a dram array, or any other type of memory device as required by the design of the print engine interface. Therefore, the message processing circuit will update the bitmap memory storage buffer 52 by activating a “FIFO memory write” signal 55 coupled to the memory storage buffer. For at least ink jet applications, the transfer circuit 57 also includes a multiplexor device 56 coupled between the ink jet printhead's video data input port 54 and the bitmap data memory storage buffer 52 for injecting NULL data between the vertical swaths of bitmap data.
The TAB includes an optional on-board CPU 58 which is used to manage higher level tasks as warranted by some types of print engines; a control port 60 controlled by the message processing circuit 44 or the on-board CPU 58 , which can be used as part of the print engine interface to transmit ink print engine instructions (otherwise known as “print engine commands”) and instruction parameters (otherwise known as “print engine command parameters”) to the print engine; and an print engine status buffer 62 monitored by the message processing circuit 44 or the on-board CPU 58 , which can be used to access print engine status information from the print engine. The CPU 58 , the control port 60 and the status port 62 are coupled to each other by a bidirectional data bus 61 .
At least in ink jet applications, the TAB also includes a Stroke Machine 63 , coupled to the bidirectional data bus 61 , for determining when to transfer a scanline (“stroke”) of the bitmap data from the memory storage buffer 52 to the ink jet printhead's video data input port 54 . This is accomplished by the activation of a “FIFO memory read” signal 64 by the Stroke Machine 63 . The stroke machine 63 provides a video data control signal 65 to the ink jet printhead 12 and controls the multiplexor 56 through a multiplexor control signal 66 . Furthermore, as will be described in further detail below, the stroke machine 63 generates the pixel deposition clock signal 68 for driving the piezoelectric crystal 70 on the corresponding ink jet printhead 12 .
Each digital decoder 36 derives an extracted digital clock signal 72 from the command/data stream transmitted by the raster printer controller 10 over the fiber optic data links 30 , 32 , 34 a-c to the ring. The command/data stream is transmitted by the raster printer controller 10 over the fiber optic ring utilizing a self-clocking data transmission code as commonly known to one of ordinary skill in the art, such as the 8B/10B encoding algorithm as described in U.S. Pat. Nos. 4,486,739 and 4,665,517. The 8B/10B code is a block code which encodes 8-bit data blocks into 10-bit code words for serial transmission. The devices supporting this 8B/10B standard range in frequency from 125 MHZ to 1.5 GHz (today), with future enhancements up to 2 to 4 GHz.
The message processing circuit 44 includes a message processing state machine 76 , an address decrement device 78 , a bi-directional command data buffer circuit 80 which couples the bidirectional data bus 61 to the output data bus 42 (or input data bus 38 ), and a bidirectional discrete data circuit 82 which couples the discrete input and output buffers 48 , 46 to the output data bus 42 (or input data bus 38 ). The bidirectional command data buffer circuit 80 includes an output data register 84 , fed by an output data buffer 86 which is controlled by the output data enable line 88 activated by the message processing state machine 76 . Likewise, the bi-directional command buffer circuit 80 includes an input data register 90 , for feeding an input data buffer 92 which is controlled by the input data enable line 94 activated by the message processing state machine 76 . The bidirectional discrete data circuit 82 includes an output discrete data buffer 96 , controlled by an output discrete data enable line 98 , activated by the message processing state machine 76 . Likewise, the bi-directional discrete data circuit 82 includes an input discrete data buffer 100 , controlled by an input discrete data enable line 102 which is activated by the message processing state machine 76 . The address decrement device 78 is controlled by a control line 104 activated by the message processing state machine 76 .
The discrete output buffer 46 , the discrete input buffer 48 , the bitmap data memory storage buffer 52 , and the other print engine interface components described above, controlled by the message processing state machine 76 , in response to commands embedded in the command/data stream sent over the ring, provide an interface between the print engines 12 and the fiber optic ring. Furthermore, this design allows the raster printer controller 10 to utilize a multiplexed command/data protocol for communicating with the plurality of TABs 20 a - 20 d , in which the raster printer controller transmits a command followed by a corresponding data-stream on the fiber optic ring.
The raster printer controller 10 initiates all commands and manages the allocation of fiber optic bandwidth to receive all print engine discretes and status. Each command contains an address field, and each TAB includes its own internal address. Thus, each TAB 20 a - 20 d monitors the commands using their respective high-speed message processing circuits 44 , and if addressed, the TABs respond appropriately. A TAB 20 a - 20 d will never respond to a command unless that particular TAB is addressed by the command or unless the command is a “broadcast” command (i.e., a particular bit of the address field could be reserved for as a broadcast bit) intended to be processed by all of the TABs. Nevertheless, as discussed above, even if the particular TAB is not addressed by the command, its message processing circuit 44 will always retransmit that command and corresponding data-stream to the next TAB on the daisy-chain (or if the present TAB is the last TAB 20 d on the daisy-chain, back to the raster printer controller). This allows all TABs 20 a - 20 d to see all of the commands all of the time
Referring to FIGS. 1 and 2, the encoder device 35 on the raster printer controller 10 embeds a digital clock signal derived from an internal clock source 73 into the encoded data transmitted on the ring. The digital decoding devices 36 , utilized by each TAB, derive the extracted digital clock signal 72 from the encoded data received on the input port 26 utilizing an on-chip data tracking phase locked loop “PLL” as is known to one of ordinary skill in the art. Therefore, each extracted digital clock signal 72 on each of the TABs 20 a-d , will have substantially the exact frequency, or a frequency that is exactly proportional to, the controller's internal clock source 73 . Therefore, because this extracted digital clock signal 72 is used to create the piezoelectric clock source 66 as described in detail below; each piezoelectric clock source 66 on each TAB will have substantially the exact frequency, eliminating beat frequency drift errors between the pixel swaths.
In one embodiment, the encoder device 35 , utilized by the raster printer controller 10 , and the digital encoders 40 , utilized by the TABs 20 a-d , are CY7B923 HOTLink™ Transmitter devices available through Cypress Semiconductor Corp. (HOTLink is a trademark of Cypress Semiconductor Corp.). These devices convert the 8-bit raw digital data blocks into 10-bit code words which are subsequently transmitted on the ring. The decoder device 39 , utilized by the raster printer controller 10 , and the digital decoders 36 , utilized by the TABs 20 a-d , are CY7B933 HOTLink™ Receiver devices also available through Cypress Semiconductor Corporation. These devices receive the 10-bit coded data, and using a completely integrated PLL clock synchronizer, recover the timing information, in the form of the extracted digital clock signal 72 , necessary for reconstructing the 8-bit raw digital data. The digital encoder 35 of the raster printer controller 10 utilizes the on-board clock source 73 as the byte rate reference clock “CKW” which is used by the encoder to create a bit rate clock embedded into the 10-bit coded data stream transmitted to the fiber optic ring. An on-board clock source 74 is used by the digital decoders 36 as a clock frequency reference (“REFCLK”) for the clock/data synchronizing PLL which tracks the frequency of the incoming bit stream and aligns the phase of its internal bit rate clock to the serial data transmissions. The extracted digital clock signal output 72 is the byte rate clock output of the digital decoders 38 , which is aligned in phase and frequency to the on-board clock source 73 of the raster printer controller. The operation and design of the HOTLink™ CY7B923/933 devices is described in detail in the HOTLink™ User's Guide (Copyright 1995, Cypress Semiconductor Corp.); and in particular, the CY7B923/933 Datasheet section (pp.1-28) of the User's Guide, the disclosure of which is incorporated herein by reference.
As shown in FIG. 3, in ink jet applications, the stroke machine 63 generates the pixel deposition clock signal 68 for driving the piezoelectric crystal 70 on the corresponding ink jet printhead 12 . It will be apparent to those of ordinary skill in the art that, with simple modifications, the design of the stroke machine described herein for ink jet applications can be used to generate the pixel deposition clock signal 68 for all other printing applications such as magnetographic, ion deposition, xerographic, laser, LED and the like. The stroke machine 63 includes a pixel deposition clock generation circuit 110 , a stroke frequency generation circuit 112 , a dispatch control circuit 114 , and a registration control circuit 116 . The extracted digital clock signal 72 , a 25 MHz signal in the present embodiment, is used by the pixel deposition clock generation circuit to generate the pixel deposition clock signal 68 for driving the piezoelectric crystal 70 on the corresponding ink jet printhead 12 .
The extracted digital clock signal 72 drives a digital counter 118 . The MSB 120 of the output count value is the clock used by the stroke frequency generation circuit 112 , the dispatch control circuit 114 , and the registration control circuit 116 . The other bits 122 of the output count value are sent to a memory device 124 which operates as a lookup table. The lookup table includes a voltage amplitude value for every count value 122 received. These voltage amplitude values 126 are sent to a digital-to-analog converter 128 which converts the voltage amplitude values 126 to their corresponding analog voltages 130 . To obtain the pixel deposition clock signal 68 , a voltage amplifier device 132 is used to amplify the analog voltages 130 to the voltage levels required for the pixel deposition clock source.
The voltage amplitude values 126 output by the memory device 124 are derived from the lookup table. The lookup table contains a particular voltage amplitude value 126 corresponding to a particular voltage amplitude level in one period of the pixel deposition clock signal's sinusoidal wave. Thus, the memory device 124 will output the particular voltage amplitude value 126 from the lookup table, depending upon the count value 122 received from the counter 118 . For example, if the count value is a five-bit value (0-31), as in the present embodiment, the lookup table will have thirty-two voltage amplitude values (for transmitting to the digital-to-analog converter 128 ) corresponding to thirty-two uniformly spaced-apart output voltages along a 5 v peak-to-peak (the peak-to-peak voltage output from the digital-to-analog converter is selected depending upon the level of amplification desired to reach the 60V peak-to-peak pixel deposition clock source signal) sinusoidal period as shown in the table below:
Count
Output
Value
Voltage
(122)
(130)
0
0.0
V
1
1.01
V
2
1.97
V
3
2.86
V
4
3.62
V
5
4.24
V
6
4.69
V
7
4.94
V
8
4.99
V
9
4.84
V
10
4.49
V
11
3.95
V
12
3.26
V
13
2.43
V
14
1.50
V
15
0.51
V
16
−0.51
V
17
−1.50
V
18
−2.43
V
19
−3.26
V
20
−3.95
V
21
−4.49
V
22
−4.84
v
23
−4.99
V
24
−4.94
V
25
−4.69
V
26
−4.24
V
27
−3.62
V
28
−2.86
V
29
−1.97
V
30
−1.01
V
31
0.0
V
In the present embodiment, a frequency divider device 134 is inserted before the digital counter 118 to further reduce the frequency of the extracted digital clock signal 72 from 25 MHz to 3.2 MHz. Accordingly, the pixel deposition clock signal 68 for the piezoelectric crystal 70 will have a frequency of {fraction (1/32 )}the frequency of the divided-down digital clock signal 136 (i.e., in the present embodiment, the pixel deposition clock signal 68 will have a frequency of 100 KHz).
The extracted digital clock signal 72 is thus used by each TAB 20 a - 20 d to generate the pixel deposition clock signal 68 for driving the pixel deposition mechanism and/or its drive mechanism on its corresponding print engine 12 a - 12 d . Therefore, because each extracted digital clock signal 72 on each of the TABs 20 a-d will have substantially the exact frequency, as discussed above, synchronization errors between the print engines will be virtually eliminated.
The present invention also includes a system and method to eliminate any phase offset errors between all of the pixel deposition clock signals 68 . As discussed above, the embedded command in the command/data stream transmitted on the ring by the raster printer controller 10 includes an address field, which specifies which TAB is to receive the command. However, in the preferred embodiment every TAB is set up with an identical predefined internal address of zero (address=0); and further, every TAB is configured to modify the address field of every command received by decrements the address field by one prior to retransmitting the command/data stream back to the ring. Thus, for example, if there are four TABs on the ring, and the raster printer controller intends to transmit a command to the fourth TAB on the ring, the address field of the command sent to the first TAB on the ring will equal three. The first TAB will not accept the command because the address field does not equal zero. The first TAB will subtract one from the address field, and it will then retransmit the command to the second TAB on the ring. The second TAB will not accept the command because the address field does not equal zero (address field now equals two). The second TAB will subtract one from the address field, and it will then retransmit the command to the third TAB on the ring. This is repeated for each TAB until the command finally reaches the fourth TAB on the ring. At this time, the address field equals zero, and therefore, the fourth TAB on the ring will accept and process the command. Because the fourth TAB does not know that it is the last TAB on the ring, it will also decrement the value of the address field prior to retransmitting the command back to the raster printer controller.
When the raster printer controller 10 boots up, it does not know the number of TABs 20 a - 20 d on the ring. Accordingly, the raster printer controller will send an initialization command to the ring. The address field of this initialization command will be decremented by each of the TABs on the ring; and thus, upon receiving the initialization command back from the ring, the raster printer controller will be able to determine the number of TABs on the ring and it will know how to address each of the TABs based upon the number of times the address field has been decremented prior to receiving the initialization command back from the ring.
The pixel deposition clock generation circuit 110 includes a preload register 138 coupled to the load port 140 of the digital counter 118 and updatable by the raster printer controller 10 via commands transmitted on the ring. As shown in FIGS. 2 and 3, the state machine 76 for controlling the operations of the message processing circuit 44 , includes a counter reset line 142 , coupled to the reset port 144 of the digital counter 118 . The preload register 138 stores a preload count which the digital counter 118 will start counting from upon being reset by the state machine 76 .
During boot-up, the raster printer controller will send a PHASE SYNC command to each TAB on the ring. This command will instruct the state machine 76 to fill the preload register 138 with the count value contained in the associated data sent with the PHASE SYNC command. The count value loaded into the preload register 138 will correspond to the number of counts the digital counter 118 will count in the time required for a command to propagate from the first TAB 20 a on the ring to the present TAB. Thus, in the present embodiment, the preload register 138 of the first TAB 20 a will be set to 0; in the present embodiment, if the time required for a command to propagate from the first TAB 20 a to the second TAB 20 b on the ring is 1.25 micro-seconds, the preload register 138 for the second TAB will be set to 4 (which corresponds to the number of counts that the digital counter 118 , counting at 3.2 MHz, will count in 1.25 micro-seconds); in the present embodiment, if the time required for a command to propagate from the first TAB 20 a to the third TAB 20 c on the ring is 2.50 micro-seconds, the preload register 138 for the second TAB will be set to 8 (which corresponds to the number of counts that the digital counter 118 , counting at 3.2 MHz, will count in 2.50 micro-seconds); and, in the present embodiment, if the time required for a command to propagate from the first TAB 20 a to the fourth TAB 20 d on the ring is 3.75 micro-seconds, the preload register 138 for the second TAB will be set to 12 (which corresponds to the number of counts that the digital counter 118 , counting at 3.2 MHz, will count in 3.75 micro-seconds).
Preferably, to allow for any number of print engines to be coupled to the ring at any one time, each fiber optic link between the TABs 20 , will have the same length. Thus, the time it takes for a command to propagate from one TAB to the next will always be equal and deterministic; and the preload register 138 preload setting will be calculated by the raster printer controller 10 as directly proportional to the position that a particular TAB will have on the ring (i.e., whether a particular TAB is the first, second, third, etc. TAB on the ring).
To reset the digital counters 138 to their respective preload values, the raster printer controller will broadcast a CLOCK RESET command to the ring. The CLOCK RESET command will, of course first be received and executed by the message processing circuit 44 of the first TAB 20 a on the ring. The state machine 76 of the first TAB's message processing circuit will, in response to the CLOCK RESET command, will activate the counter reset line 142 , which in turn resets the counter 118 to start counting at its corresponding preload value, read from its corresponding preload register 138 . The first TAB will then pass the command to the next TAB 20 b on the ring. Likewise, each successive TAB, upon receiving this command will reset its counter 118 to start counting at its corresponding preload value, read from its corresponding preload register 138 ; and the will then pass the command to the next TAB on the ring, until the command is eventually passed back to the raster printer controller 10 . Because each preload register 138 on each TAB is set to an initial count value corresponding to the time it takes for the command to propagate to the respective TAB, the voltage levels 130 output from the digital-to-analog converter 128 on all the TABs will be equal at any given time. Thus, in addition to each piezoelectric clock source being locked in frequency as described above, each piezoelectric clock source will also be locked in phase.
As shown in FIG. 3, the stroke frequency generation circuit 112 , includes a stroke clock counter 146 and a stroke rate preload register 148 updatable by the raster printer controller 10 . The terminal count output 149 of the stroke clock counter 146 is the stroke clock signal 150 sent to the registration circuit 116 and the dispatch circuit 114 . A typical stroke frequency is approximately 50 Khz. The 50 Khz stroke signal could be embedded into the command/data protocol and sent to each of the TABs; however, this would impair the bandwidth capabilities of the command/data protocol. Therefore, the raster printer controller will send a command within the command/data stream to each of the TABs on the ring at a 1 or 2 Khz rate indicative of the web velocity and/or acceleration. Based upon this velocity/acceleration data in the command, the microcontroller 58 will calculate a preload value to load into the stroke rate preload register 148 which is the accurate count of the number of piezo cycles between the dispatch of real bitmap data. The terminal count output 149 of the stroke clock counter 146 will activate every time the stroke clock counter 146 counts down from the preload value (stored in the preload register 148 ) to zero. All piezo cycles between the stroke periods get null data. Therefore, the stroke frequency generation circuit 112 provides an alternate approach to stroke clock generation when real-time shaft clock transmission over the fiber optic cable is not feasible.
The registration circuit 116 , the design of which is practical knowledge to those of ordinary skill in the art, controls the issuance of the Top of Form signal 152 based upon the stroke clock signal 150 and the piezo cycle frequency signal 120 . In generating the Top of Form signal 152 , the registration circuit may also take into account clamp distance values and/or flight delay values as updated by the raster printer controller 10 using the command/data protocol scheme of the present invention.
The dispatch circuit 114 , the design of which is practical knowledge to those of ordinary skill in the art, controls the issuance of the FIFO Memory Read signal 64 and the multiplexor control signal 66 (for injecting null data) based upon the stroke clock signal 150 , the Top of Form signal 152 , an End of Page signal 154 generated by the bitmap memory storage device 52 , and the piezo cycle frequency signal 120 . In generating the FIFO Memory Read signal 64 , the dispatch circuit may take into account drops-per-dot values and/or stroke width values as updated by the raster printer controller 10 using the command/data protocol scheme of the present invention.
In conclusion, the present invention provides a high-speed printer controller system which is configured to control and “lock-step” a multitude of print engines simultaneously, and which is also configured to synchronize, in frequency as well as phase, all of the pixel deposition mechanisms located within the print engines. Further, while the system and method described herein constitutes the preferred embodiments of the present inventions, it is to be understood that the present inventions are not limited to their precise form, and that variations may be made without departing from the scope of the invention as set forth in the following claims,
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The present invention provides a system and method for simultaneously controlling a plurality of print engines connected together (in series, in parallel or otherwise) that facilitates electronic stitching between the print engines. More specifically, the present invention provides a system and method for synchronizing the pixel deposition frequencies and the drive mechanisms between the various inter-connected print engines so as to eliminate synchronization between the print engines. The method for synchronizing the pixel deposition frequencies and/or drive mechanisms between a plurality of print engines comprises the steps of: (a) coupling the plurality of print engines together with a printer controller, (b) embedding a first clock signal in data; (c) transmitting the data to the print engines; (d) each of the print engines receiving the data; (e) each of the print engines deriving a second clock signal from the data received, which is directly proportional to the first clock signal; and (f) each of the print engines driving its corresponding pixel deposition mechanism and/or its drive mechanisms with the second clock signal.
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FIELD OF INVENTION
This invention relates to valves and is particularly concerned with a novel thermomagnetic valve which utilizes the Curie temperature property of magnetic materials.
BACKGROUND
As is well known, a metallic or non-metallic magnetic material loses its magnetic properties upon being heated to a temperature above its Curie temperature and regains its magnetic properties upon being cooled to a temperature below its Curie temperature. Various devices have heretofore been proposed which utilize this phenomenon. Examples of such devices are described in United States Letters Patent No. 3,149,246 issued to W. P. Mason on Sept. 15, 1964, United States Letters Patent No. 3,445,740 issued on May 20, 1969 to G. G. Merkl and United States Letters Patent No. 3,743,866 issued on July 3, 1973 to A. Pire.
SUMMARY AND OBJECTS OF INVENTION
A major object of this invention resides in the provision of a novel thermomagnetically controlled valve which utilizes the Curie temperature phenomenon mentioned above.
In the preferred embodiment, the valve unit of this invention comprises a pair of valves, the first of which controls flow of fluid between first and second operating ports or passages, and the second of which controls flow of fluid between the above-mentioned first operating port and a third operating port or passage. According to this invention, a thermomagnetic actuator for operating the two valves mentioned above comprises an actuator member which is common to the two valves and first and second magnetic members adapted to cooperate with a permanent magnet for displacing the actuator member between two operating positions. In one operating position, the actuator member opens the first valve and closes the second valve and in its other operating position, the actuator member closes the first valve and opens the second valve.
The magnetic members are each mounted on or otherwise operatively connected to the actuator member in such a manner that when one magnetic member is attracted to the magnet, it displaces the actuator to one of its operating positions and when the other magnetic member is attracted to the magnet, it shifts the actuator member to the other of its operating positions.
Thus by alternately heating the two magnetic members to temperatures above their Curie temperatures, the actuator member is flipped back and forth between its two operating positions to thereby alternately open the two valves mentioned above.
In the preferred embodiment the two magnetic members are so positioned that they are subject to the temperature of fluid at the second and third operating ports respectively. By selecting the Curie temperatures of the magnetic members to be less than the temperature of the fluid, the fluid is caused to flow alternately and cyclically through the second and third operating ports from a source connected to the first operating port.
With the foregoing in mind, another important object of this invention is to provide a novel valve unit which utilizes the Curie temperature phenomenon to thermagnetically control operation of a valve.
Another object of this invention is to provide a novel flip-flop type valve unit in which a thermomagnetic device alternately establishes first and second magnetic couplings to cyclically displace a valve actuator to two different operating positions, and in which the valve actuator is effective to open a first valve when in one of its operating positions and to open a second valve when in its other operating position.
Still another object of this invention is to provide a novel thermomagnetic valve unit in which a magnetic member is positioned on the downstream side of a valve so that it will be heated to a temperature above its Curie temperature by heated fluid when the valve is opened, in which the magnetic member is attracted to a magnet when its temperature is below its Curie temperature, in which an actuator is positioned by the magnetic member when the latter is coupled to the magnet to open the valve, and in which the magnetic member de-couples from the magnet upon being heated by the fluid to enable the actuator to close the valve.
A further object of this invention is to provide a novel logic gate which is thermomagnetically operated for employment in a hydraulic or fluid circuit.
Further objects of this invention will appear as the description proceeds in conjunction with the appended claims and the below described drawings.
DESCRIPTION OF DRAWINGS
FIG. 1 is a partially sectioned, partially schematic plan view of a valve unit incorporating the principles of this invention; and
FIG. 2 is a schematic diagram of a fluid circuit incorporating the valve unit of this invention as a logic gate.
DETAILED DESCRIPTION
Referring to FIG. 1, a thermally responsive flip-flop type valve unit 10 incorporating the principles of this invention is shown to comprise a housing 12, a pair of valves 14 and 16, and a thermomagnetic actuator assembly 18 for valves 14 and 16.
Housing 12 may be formed by conduit sections 20, 21 and 22 which respectively define fluid flow passages 24, 25 and 26. Passages 24, 25 and 26 may respectively terminate in operating ports 28, 29 and 30 as shown. Passage 24 is common to and in fluid communication with passages 25 and 26.
Valve 14 is arranged in conduit section 21 to control flow of fluid between operating ports 28 and 29. Valve 16 is arranged in conduit section 22 to control flow of fluid between operating ports 28 and 30.
In FIG. 1, conduit section 20 is connected through a suitable valve 32 to a source of heated fluid which is indicated at 34. With this arrangement, therefore, port 28 is an inlet port and ports 29 and 30 are outlet ports. When valve 32 is opened, fluid from source 34 will flow into the valve unit through passage 24. From passage 24, the fluid flows out of the valve unit through either passage 25 or passage 26 depending upon which of the two valves 14 and 16 is opened.
In accordance with this invention, actuator assembly 18 comprises a permanent magnet 36, a pair of magnetic bars or members 38 and 40 and a valve-actuating rocker member 42. Rocker member 42 is pivotally mounted in housing 10 by a pin 44 at the juncture of conduit section 20 with conduit sections 21 and 22. Rocker member 42 has a pair of arms 46 and 48 extending in opposite directions from pivot pin 44 into conduit sections 21 and 22 respectively. Rocker 42 is preferably symmetrical about the axis of pin 44 as shown.
Valve 14 comprises a valve closure member 50 and an annular valve seat 52. Valve 16 is preferably of the same construction as valve 14 and comprises a valve closure member 54 and an annular valve seat 56. Seats 52 and 56, which may be rigid, are positioned and fixed in conduit sections 21 and 22 respectively.
Closure member 50 is mounted on and fixed to arm 46 near the free end of the rocker arm in conduit section 21. Similarly, closure member 54 is mounted on and fixed to arm 48 near the free end thereof in conduit section 22.
In this embodiment, each of the valve closure members 50 and 54 is in the form of a washer or similar annular member and may be formed from rubber or plastics material with sufficient deformability to interfittingly and snugly seat tightly against its associated valve seat. Rocker arm 46 extends freely through the fluid flow port or passage defined by valve seat 52 such that valve member 50 is on the downstream side of seat 52 as shown. Likewise, rocker arm 48 extends freely through the fluid flow passage or port defined by valve seat 56 such that closure member 54 is on the downstream side of seat 56.
From the foregoing construction it is clear that when rocker member 42 is rocked counterclockwise about the axis of pivot pin 44, closure member 50 lifts off seat 52 to allow fluid to pass through and beyond seat 52, and closure member 54 seats on seat 56 to establish a hermetic seal with seat 56 which blocks flow of fluid past the valve seat. When rocker member 42 is rocked clockwise about the axis of pivot pin 44, valve closure member 54 lifts off seat 56 to permit fluid to flow through seat 56, and valve closure member 50 seats on seat 52 to establish a hermetic seal with seat 52 which blocks fluid flow past the valve seat. Clockwise displacement of rocker member 42 is limited by seating engagement with seat 52, and counterclockwise displacement of rocker member 42 is limited by seating engagement with seat 56.
From the foregoing it will be appreciated that pivotal displacement of rocker member 42 to its extreme counterclockwise position blocks flow of fluid through passage 26 and permits flow of fluid through passage 25. Pivotal displacement of rocker member 42 to its extreme clockwise position, on the other hand blocks flow of fluid through passage 25, but permits flow of fluid through passage 26.
The axis about which rocker member 42 is pivotal about pivot 56 is normal to fluid flow paths entering passages 25 and 26 upstream from valve seats 52 and 56. Pivot 44 is positioned upstream from seats 52 and 56.
As shown, the magnetic member 38 is fixed in a socket which is formed at the free end of rocker arm 46 in passage 25. Similarly, the magnetic member 40 is fixed in a socket which is formed at the free end of rocker arm 48 in passage 26. Members 38 and 40 are adapted to be alternately attracted to magnet 36 as will be described in detail shortly.
In this embodiment, magnet 36 is suitably mounted between conduits sections 21 and 22 as shown. The arrangement and positioning of magnet 36 and members 38 and 40 is such that members 38 and 40 will be in the magnetic field developed by magnet 36 and hence are attractable to magnet 36. As shown, the poles of magnet 36 are positioned closely in the region of members 38 and 40.
The metal or other material employed for making members 38 and 40 has a pre-selected Curie temperature. Thus, upon heating each of the members 38 and 40 to a temperature above its Curie point, it loses its magnetic properties and can no longer be attracted by magnet 52 as is well known. When each magnetic member is allowed to cool to a temperature below its Curie temperature, it regains its magnetic properties. Any suitable metal alloy having a desired Curie temperature may be selected to form members 38 and 40. For example, a suitable Nickel iron alloy may be employed. Alternatively, member 38 and 40 may be made fro Gadolinium. The Curie temperature selected is dependent upon various factors such as the temperature of the fluid to be conveyed by valve unit 10 and the duration of flow of the fluid which is desired through each of the passages 25 and 26. Both of the members 38 and 40 may be made from the same metal or metal alloy so that they both have the same Curie temperature. The Curie temperatures for members 38 and 40 is selected to be somewhat less than the temperature of the fluid conveyed from source 34.
As shown, member 38 is positioned in passage 25 on the downstream side of valve seat 52 so that it is in the path of and is heated by fluid entering through passage 24 and passing through seat 52 when closure member 50 is in its open position where it lifted off seat 52. Likewise, member 40 is positioned in passage 26 on the downstream side of valve seat 56 so that it is in the path of and is heated by fluid entering passage 24 and passing through valve seat 56 when closure member 54 is in its open position where it lifted off valve seat 56.
Thus, when rocker member 42 is rocked to its illustrated extreme counterclockwise position to open the fluid flow port through valve seat 52 and to close the fluid flow port through valve seat 56, member 38 will be heated by the fluid flowing through passage 25 while member 40 is allowed to cool to a temperature below that of its Curie temperature since flow of fluid through passage 26 is blocked. When rocker member 42 is rocked to its extreme clockwise position to open the fluid flow port through valve seat 56 and to close the fluid flow port through valve seat 52, member 40 will be heated by the fluid flowing through passage 26, while member 38 is allowed to cool to a temperature below that of its Curie temperature.
In operation of valve unit 10, assume that rocker member 42 is in its illustrated extreme counterclockwise position. Before heating fluid from source 34 is supplied to passage 24 by way of valve 32, members 38 and 40 will be relatively cool and at a temperature below their common Curie temperature. Member 38 will therefore be attracted by magnet 36 to hold rocker member 42 in its illustrated position. When the fluid is supplied to passage 24 from source 34, it will therefore flow through valve seat 52, but not through valve seat 56. Member 38 will therefore begin to heat while member 40 remains relatively cool and below its Curie temperature. As the fluid continues to flow past member 38 in passage 25, member 38 heats up, and after a pre-selected or predetermined time period, the temperature of member 38 will rise to a level which is above its Curie temperature. At this time, member 38 loses its magnetic properties and therefore can no longer be attracted by magnet 36.
The assembly of rocker member 42, closure members 50 and 54 and members 38 and 40 is balanced in such a manner that in absence the magnetic influence of magnet 36, rocker member 42 will assume a position about midway between its extreme clockwise and counterclockwise positions. Thus when member 38 is heated by the heating fluid to a temperature above its Curie temperature, the resulting removal of the magnetic coupling with member 38 enables rocker member 42 to pivot clockwise to move member 40 toward a pole of magnet 36 and hence into the denser region of the magnet's magnetic field.
As a result, magnet 36 attracts member 40 to continue the clockwise displacement of rocker member 42 to its extreme clockwise position where the fluid flow port through valve seat 56 is opened and the fluid flow port through valve seat 52 is closed. The fluid will consequently be diverted to flow through passage 26 to heat member 40. Additionally, flow of heating fluid through passage 25 will be blocked with the result that member 38 will begin to cool.
After a pre-selected or predetermined time period, the temperature of member 40 will be raised by the fluid to a level above its Curie temperature, and member 40 will therefore lose its magnetic properties so that it will no longer be attracted by magnet 36. By this time, member 38 will have cooled sufficiently so that its temperature will be below its Curie temperature to regain its magnetic properties.
Rocker member 42 will therefore rock counterclockwise to move member 38 closer to a pole of magnet 36, while moving member 40 away from the permanent magnet. Member 38 therefore is attracted by magnet 36 to rock member 42 to its extreme counterclockwise position where the fluid flow port through valve seat 56 is closed and the fluid flow port through valve seat 52 is open. Therefore, the fluid will again be diverted to flow through passage 25. Now, member 40 is allowed to cool while member 38 is being heated by the heating fluid flowing through passage 25 to repeat the switching operation described above. Thus, valve unit 10 cyclically and alternately directs the fluid through passages 25 and 26 for pre-selected time intervals. If the Curie temperatures are the same, fluid will alternately flow through passages 25 and 26 for equal time intervals and hence at a constant repetition rate.
The motivating or actuating fluid at source 34 may be a liquid or a gas. Alternatively, a heating medium other than the fluid supplied from source 34 could be employed to alternately heat members 38 and 40.
Valve unit 10 may be employed wherever it is desired to cause a fluid to flow alternately through two different conduits at a pre-selected repetition rate. For example, it may be desired to alternately heat two devices or two bodies of liquid or gases with the fluid supplied through passages 25 and 26.
The valve unit of this invention may also be employed in a hydraulic or fluid logic circuit to accomplish, for example, automatic counting or other automatic functions. In this respect, the valve unit of this invention is capable of performing binary decisions, and it can be employed as an oscillator when a continuous supply of motivating gas or liquid is supplied to inlet port 28.
The valve unit of this invention can also be employed as a bistable device under conditions where only a pulse of motivating fluid is supplied to the inlet port shown in FIG. 1.
On the other hand, continuous flow of heated motivating fluid into passage 28 causes the valve unit of FIG. 1 to operate a monostable device.
Additionally, the valve unit of this invention may be employed as a logic gate in a hydraulic or fluid circuit. For example, it may be employed as an exclusive or gate by feeding pulses of motivating fluid to either port 29 and/or port 30 from fluid circuit sources 70 and 72, respectively. A pulse of motivating fluid from either of these sources results in passage of the fluid through port 28 to a fluid signal utilization device 74.
Finally, the valve unit of this invention can readily be converted to a special, monostable device by replacing one of the magnetic members 38 and 40 with a spring (not shown) which is arranged to normally bias rocker member 42 to a pre-selected one of its two operating positions (i.e., its extreme counterclockwise position or its extreme clockwise position). With such an arrangement, rocker member 42 is biased to one of its two operating positions by the spring, and the unremoved one of the two magnetic members 38 and 40 causes displacement of rocker member 42 to its other operating position upon being attracted to magnet 36.
Magnet 36 is held stationary or fixed in place by any suitable means such as an unshown bracket which may be secured to housing 12.
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A hot fluid is directed through a valved conduit inlet. Downstream of the inlet, the conduit divides into a pair of outlets through which the hot fluid flows. The flow through the outlets is controlled by a pair of vertically oriented valves linked together by a V-shaped linkage and weight biased toward the closed position such that when one valve is open the other is closed, and vice versa. The valve actuation means comprises a permanent magnet mounted on the housing in close proximity to each valve; each valve has mounted thereon and exposed to the hot fluid a magnetic material. Thus, when the magnetic material on the open valve is heated above its Curie temperature, the material loses its attraction for the permanent magnet and the weight bias closes that valve and simultaneously moves the other valve close enough to the permanent magnet to be held open thereby. When that valve's magnetic material is heated above the Curie temperature it in turn closes and the other valve opens. Thus, as long as fluid heated to a temperature above the Curie temperature of the magnetic valve material is flowing through the device, continuous oscillation of the valves occurs.
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BACKGROUND OF THE INVENTION
The invention relates to a storage device for recording media that have a flat form, such as magnetic tape cassettes and compact discs.
A typical device for storing such recording media is shown in U.S. Pat. No. 3,836,222. The '222 device comprises a grid-like framework relative to which slider members can be moved. Each slider member consists of a block that is guided on the framework and is screwed to a plate. On the plate in the area inside the framework is mounted a part of a locking mechanism, in front of which a box-like component, having a front wall, is fastened on the plate. On this box-like component there is hinged a pocket having an extension piece which projects into a free space provided in the framework and, when the slider member is ejected, runs up a cross-piece of the framework and as a result pivots the pocket.
One problem with the '222 device is that it requires a great deal of space in relation to the size of the recording media to be stored and, because of its complicated construction, can be manufactured only at considerable expense.
A problem with other existing devices, such as that described in German Patent Document No. PS 22 48 408, is that such devices require a certain amount of dexterity when being used. This is a significant disadvantage when the device is to be used by the driver of a motor vehicle.
SUMMARY OF THE INVENTION
The present invention solves these problems and provides other benefits. The present invention is suitable for use by a driver while driving a motor vehicle without distracting the driver's attention. At the same time, the device of the present invention requires a minimum amount of space and can be manufactured economically from a small number of components.
Broadly, the container of this invention may be defined as follows:
A storage device for flat recording media comprising:
(a) a housing having a bottom wall, a top wall, two elongate side walls, a rear wall, and an open front side;
(b) a slider member for receiving at least one recording medium, the slider member being movably mounted in the housing and having a base portion and a front wall;
(c) means for biasing the slider member to an open position out of the housing;
(d) means for locking the slider member to a closed position within the housing against the bias of the biasing means; and
(e) lifting means for supporting and engaging underneath the recording medium, said lifting means when the device is in the open position raising the recording medium to a lifted position away from the base portion of the slider member and above the front wall of the slider member so that the recording medium is accessible for removal and insertion.
BRIEF DESCRIPTION OF THE DRAWINGS
To facilitate further discussion of the invention, the following drawings are provided, in which:
FIG. 1 shows a plan view, partly broken-away, of a first embodiment, intended for accommodating three magnetic tape cassettes;
FIG. 2 is a view taken along line 2--2 of FIG. 1;
FIG. 3 is a plan view of the lifting element of this embodiment;
FIG. 4 is a perspective view of a second embodiment;
FIGS. 5 to 7 are sectional views of variants of the lifting element actuation means;
FIG. 8 shows a sectional view of a further embodiment;
FIG. 9 is a view of a section parallel to the front wall of the device according to FIG. 8;
FIG. 10 shows a further embodiment, shown in an almost opened state (FIG. 10a) and in a completely opened state (FIG. 10b);
FIG. 11 shows a cut-away plan view of a device of this invention for the storage of compact discs;
FIG. 12 shows a plan view of the associated slider member;
FIG. 13 shows a sectional view of part of the arrangement of receiving platters in the storage position;
FIG. 14 shows, analogously to FIG. 13, the removal position; and
FIG. 15 shows a side sectional view of the device when open.
DETAILED DESCRIPTION OF THE INVENTION
The device according to FIGS. 1 to 3 comprises an outer housing 10 having a substantially slab-like basic form. The housing has a top wall 12, a base wall 14, a rear wall 16, and side walls 18 and 20. The side of the housing opposite the rear wall forms an open front face. Rails 22 extend along the base wall, parallel to the side walls, from the rear wall 16 to the open face of the housing. The rails 22 define a guide path for the sliding movement of a slider member 24, which comprises a rear plate 26, a base plate 28, and a front plate 30. Two parallel slots 32 extend from the rear plate 26 to the front plate 30 and divide the base plate into three separate platter elements.
The inner edges of the outer platter elements are stepped, as shown at 34, and the rails 22 engage over the steps and thus retain the slider member. A helical pressure spring 36 clamped between the rear wall 16 of the housing and the rear plate 26 of the slider member biases the slider member in the discharge direction, that is, the position shown in FIGS. 1 and 2. Stops are formed integrally with the base plate 28 of the slider member at the housing end, which stops slide in slots 38 in the base wall 14 of the housing and limit the outward travel.
In its storage position, that is, when it is inside the housing, the slider member is held against the bias of the spring 36 by means of locking means. For this purpose, a detent 40 on the underside of a key 42 is formed integrally with the base plate of the slider member. The key 42 is defined by a slot 44, which extends through the front plate 30 into the .[.relevant.]. .Iadd.adjacent .Iaddend.platter element of the base. The portion 46 acts as a leaf spring that is connected with the rest of the base plate 28 by connection portion 48. This leaf spring also carries the actuating button 50, which lies approximately in the plane of the front plate 30. By means of this button the user can lift the detent 40 out of a complementary recess 41 in the base wall of the housing, whereupon the slider member is pushed out by the pressure spring 36.
The actuating button 50, together with the front plate 30 of the slider member, substantially close the open face of the housing when the slider member is pushed in and locked.
The rear plate 26 of the slider member does not extend across the whole width of the housing and a free space is left on each side. Before the slider member is mounted in the housing, a frame piece 52 is attached to it. Its construction can be seen in FIG. 3. The frame piece 52 comprises a cassette lifting element 54 having upwardly .[.project.]. .Iadd.projecting .Iaddend.lateral rims 56, the outer faces of which are at a distance from one another that is slightly smaller than the internal width of the housing between its side walls 18 and 20. From the ends of these rims inside the housing there extend inwardly toward one another hook portions 58 which are at a predetermined distance from the transverse end edge 60 of the lifting element. The gap so defined allows the frame piece 52 to be placed over the ends of the rear plate 26 of the slider member in such a manner that the lifting element can be moved to the removal position in which the lifting element 54 is pivoted upwards and outwards as in FIG. 2. In that position the rims 56 rest against the front edge of the top wall 12 of the housing. In the storage position, the lifting element 54 is substantially parallel to the base plate 28 of the slider member.
Resilient elements bias the lifting element 54 towards the pivoted-out position. Two metallic leaf springs 62 are positioned in complementary recesses 64 in the base plate 28 of the slider member and press against the underside of the lifting element 54. Lifting element 54 has projecting ribs 66 to prevent the leaf springs 62 from becoming displaced
Leaf springs 62 typically are made from metal. It is, of course, also possible for the leaf springs 62 to be made of plastic material and integrally molded with the other components of the device. However, because the springs are permanently deflected when the device is closed it would be necessary to use a plastic material having no tendency for cold flow. That would cost more than the use of metal springs. The foregoing is true for the ejection .[.springs.]. .Iadd.spring .Iaddend.36.
On the upper side of the lifting element there are .[.constructed.]. .Iadd.provided .Iaddend.upwardly projecting stops 70, against which the cassettes, such as three cassettes 76, can be supported. In order that the tape winding hubs of the cassettes 76 are secured against turning when in the storage position, the base plate 28 of the slider member has upwardly projecting retaining lugs 72. The lugs extend through holes 74 aligned with them in the lifting element 54 and into the winding hubs when the lifting element is depressed. When the slider member is in the outward position, the cassettes are lifted with their outer ends above the level of the free edge of the front plate 30. At the same time the winding hubs come free of the retaining lugs so that the cassettes can be removed from the front.
Little dexterity is required to replace the cassettes, as they can simply be placed onto the lifting element. Then the front plate 30 of the slider member is pushed into the outer housing. This causes the rims 56 to be pressed downwards by a wedge action against the front edge of the top wall 12 of the housing.
The device according to FIGS. 1-3 has been described very thoroughly, with regard to certain details, such as guides, stops, and ejection springs. Therefore, only the particular characteristic details of the other embodiments are described.
In the device of FIG. 4, unlike that of FIGS. 1 to 3, the slider member is .[.constructed.]. .Iadd.designed .Iaddend.for the accommodation of two magnetic tape cassettes, for example, standardized video cassettes. The lifting element 80 is provided with a separating bar 81. The locking arrangement is located approximately in the center of the front plate of the slider member. In addition, the slider member is guided by means of its side plates 82 on the side walls of the housing rather than the rail arrangement on the base of the housing of the embodiment according to FIGS. 1-3.
FIGS. 5 to 7 illustrate three ways of actuating the lifting element 80 to a position in which the cassettes can be easily inserted and removed. In FIG. 5, the lifting element is connected to the slider member 84 by means of a pivot joint 83 and a leaf spring 79. Leaf spring 79 is fastened at one end to the base of the slider member and presses with its other, free end against the lifting element, thereby pressing the free end of the lifting element upwardly. The cassettes rest against a stop 88.
In FIG. 6, a free edge 85 of an internal wall 86 of lifting element 80 contacts an inwardly projecting bar 87 on the housing. As a result, the lifting element is pivoted about its pivot bearing 83.
In FIG. 7, a biasing spring is provided for the lifting element in the form of a torsion coil spring 89 having two leg sections or wire ends. One leg is supported on the base of the slider member and the other leg is supported against the bottom of the lifting element 80. The lifting angle is limited by stop pins 90, which extend from the sides of the lifting element into openings 91 in the side plates 82 of the slider member. Stop pins 90 come to rest against the upper end edge of those openings.
FIGS. 8 and 9 show a variant of FIG. 6. In a double housing 200, a double slider member 202 is guided in grooves 201, which are located in the horizontal plane of symmetry of the housing. Extending from a central plate 204 of the slider member are pairs of lateral bearing blocks 203 and 203'. In the upper bearing blocks 203, a lifting element 205, analogous to the lifting element 80 in FIGS. 4 to 7, is mounted such that it can be pivoted through a limited angle. A suspension element 206 is pivotably mounted in the lower bearing blocks 203'. Suspension element 206 comprises a platter 208 designed to accommodate one or more cassettes 207 and a suspension plate 209. Suspension plate 209 extends upwardly at a right angle from platter 208 to a pivotal engagement with bearing block 203'.
The lifting element 205 is lowered by the force of gravity when the slider is pushed in. The suspension element 206 is lifted by wedge action when platter 208 hits the front edge 210 of the housing. At the same time, edge 210 limits the downward pivoting movement of suspension element 206. Retaining lugs 211 are formed, in mirror-symmetrical arrangement, integrally with the central plate 204 of the slider member. When the cassette 207 on lifting element 205 is lowered, the retaining lugs 211 engage through openings 212 in the lifting element. The lower retaining lugs are free to pass from above through the tape winding hubs in cassette 207 on the suspension element 206. A double front plate 213 is provided at the outer end of the central plate 204 of the slider member. Stops 214 prevent the cassettes from slipping.
The embodiments described are devices for storing magnetic tape cassettes. The following two embodiments are used for accommodating records or video discs, and especially for storing standardized, so-called "compact discs." Because these discs are very thin in relation to their diameter, the space in the interior of the housing is best utilized when the discs are closely packed together when in the housing. The discs are presented for convenient removal when the discs are out of the housing.
The embodiment shown in FIGS. 10a and 10b comprises a slider member 301, which can be pushed out of and into a housing 300. On each side of front plate 309 of the slider is hinged a pair of guide bars 302. Guide bars 302 are pivotable about axes 303 and extend parallel to the front plate 309 of the slider member when the slider member is withdrawn from the housing member. The relationship of the distance between the pairs of axes 303 to the length of the guide bars 302 is such that when the slider member is withdrawn from the housing both guide bars are free to pivot upwardly. However, in the storage position, the guide bars are pivoted inwardly so that an uppermost disc-holder 304 will still fit underneath top wall 305 of the housing. The free ends of the guide bars are hinged to uppermost disc-holder 304 at the same axial spacing the other ends of the guide bars are spaced on the slider member. The other disc-holders 306, 307, and 308 are hinged to guide bars 302 through axes. Although the spacing between the axes is constant, the distance between the pivot axes and the front plate 309 of the slider member increases from right to left in FIG. 10a.
In the open position the lowermost disc-holder 308 extends into the housing 300. Actuator extensions 312 of disc-holder 308 project laterally from the disc-holder, close to the open front of the housing. Extensions 312 engage behind guide ribs 311, which project inwardly from side walls 310 of the housing. As soon as the actuator extensions 312 contact the guide ribs 311 when the slide is ejected, the actuator extensions 312 slide upwardly along the guide ribs 311.
The parallelogram arrangement is formed by the guide bars and the disc-holders hinged thereon in the unfolded position according to FIG. 10b. In the unfolded position, the individual disc-holders are sufficiently spaced apart for the compact discs 313 lying on them to be accessible from above and pushed forward with the fingers. If desired, the disc-holders can be provided with a cut-out portion at the front for access to the discs. In addition, the holders are stepped backwards to further facilitate access to the discs.
In FIGS. 11-15 a slider member 101 is slidably movable in the housing 100. For this purpose, the slider member comprises two base plates 109 and 110, which are connected to one another at the front of the slider member by a front plate 111 and at the rear by a rear plate 108. A step 102 projects from both base plates into the empty space 128 between these plates. Two guide rails 103 project inwardly from the housing base 129 and engage over these steps. The base plates 109 and 110 are reinforced by upright side edges 112. These edges, near the inner end of the slider member, become cheeks 113, which are joined to lugs 107. The lugs extend at right-angles to the cheeks. The height of cheeks 113 and the lugs 107 is substantially the height of the interior of the housing, as shown in FIG. 15. Helical pressure springs 106 are supported at one end against rear wall 131 of the housing and at the other end against the lugs 107. Springs 106 force the slider member out of the housing. In its insertion position, the slider member 101 is secured by a catch 105, which locks into a recess 130 in the housing base 129. The catch 105 is integrally formed with a spring button 104 and can be released by raising button 104 with the finger. Because the slider member is made of resiliently deformable plastic material, the spring button 104 can be readily separated from the material of the base plate 109 by means of the slits 104a shown in FIG. 12. The extent to which the slider member can be ejected is limited by stops which cooperate with counter stops in the housing (not shown).
Bearing pins 11 of receiving platters 114 for respective compact discs 125 are accommodated in bearing apertures 132 in the cheeks 113. A total of five receiving platters are arranged one above the other. The individual receiving platters 114 differ from one another in the shape and position of their lever arms 116, 120, 121, 122, and 123. The lever arm 116 of the uppermost receiving platter 114 extends substantially over the width of the slider member between the springs 106. At the end of lever arm 116 are two pegs or hooks 117 which project lateraly. Onto each hook 117 is hooked a tension spring 118. The other ends of the tension springs 118 are anchored in lugs 119, which project upwardly from the base plates 109 and 110 of the slider member. Accordingly, if the slider member 101 is unlocked and ejected from the housing 100 by the springs 106, a torque produced by the biasing of the springs 118 acts on the lever arm 116 and the uppermost receiving platter 114 is swung into the position shown in FIG. 15.
During this swinging movement, the other receiving platters are spread out as a result of the lever arm 116 of the uppermost platter acting on the lever arms 120, 121, and 122, arranged next to one another in a staggered configuration. Lever arms 120, 121, and 122 are activated by lever arm 116. Because the lever arms are of different lengths, their angle of spread is correspondingly smaller than that of the uppermost platter 114. For the lowest receiving platter, the lever ratios for operation by the lever arm 116 are unfavorable. Therefore, the lever arm 123 is activated, not by the lever arm 116, but by the lever arm 122 arranged above it (FIG. 14). The three lowest receiving platters have cut-out portion 124 so that there is room for the tension springs 118.
The records are held securely in position by means of central hub projections 126. The records can be raised by gripping them in the area of the front cut-out portions 127 of the receiving platters. A supporting rim 133 of the receiving platters defines their distance from one another in the storage position.
Variations and modifications will be apparent to one skilled in the art, and the claims are intended to cover all variations and modifications that fall within the true spirit and scope of the invention.
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A storage device for flat recording media, e.g. compact discs, is disclosed. The device comprises a housing and a slider member having a base portion and front wall that covers the open front face of the housing when the slider member is inserted. A lifting element, which is transported out of the housing by means of the slider member, is provided for supporting the recording media in a position for easy insertion and removal.
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BACKGROUND
[0001] 1. Field
[0002] The following description relates to a refrigerator/freezer ice bucket.
[0003] 2. Description of Related Art
[0004] A conventional ice bucket for a refrigerator/freezer unit is a plastic bin that is used to store ice cubes. If an icemaker is included in the refrigerator/freezer unit, the ice bucket may be placed underneath the icemaker to collect ice cubes made by the icemaker. The ice cubes made can be preserved in the ice bucket until being retrieved by a user of the refrigerator/freezer unit.
[0005] If an ice dispenser is included in the refrigerator/freezer unit, the ice bucket may be machined to accept an auger provided by the ice dispenser. The auger may force ice cubes stored in the ice bucket to the ice dispenser when the user makes a request for ice cubes via the ice dispenser. A spring hinge or the like can be used by the icemaker to detect a volume of ice cubes within the ice bucket in order to inhibit the icemaker from making more ice cubes than can be contained by the ice bucket.
[0006] The plastic bin serving as the conventional ice bucket for an icemaker and an ice dispenser is machined to accept a certain, nonadjustable volume of ice cubes and an auger to force the ice cubes from the ice bucket to the ice dispenser when a request for ice cubes is made by a user. While the user typically desires a large ice bucket so a large amount of ice cubes can be stored therein, a large ice bucket may have an adverse effect on available space inside the refrigerator/freezer unit for storage of other items. Further, while the user typically desires a large amount of available storage space for other items inside the refrigerator/freezer unit, a smaller ice bucket may be inconvenient for the maintenance of a large amount of ice cubes for occasions such as parties, hosting guests, cooler use during long trips, or the like.
SUMMARY
[0007] In one general aspect, a refrigerator/freezer ice bucket may include a dispenser interface configured to deliver ice cubes to an ice dispenser upon a request by a user for the ice cubes. The dispenser interface may include a back wall. The ice bucket may further include storage configured to, with the back wall of the dispenser interface, store the ice cubes until the user request. The storage includes a fixed portion and a hinged outer wall. The hinged outer wall is configured to pivot from a position that is parallel to an opposite wall of the fixed portion to a position in which one or more portions of the hinged outer wall are fixed to be slanted upwardly away from the opposite wall of the fixed portion, thereby expanding a capacity of the storage.
[0008] The hinged outer wall may include a lower adjustable portion hinged to the fixed portion and an upper adjustable portion hinged to the lower adjustable portion.
[0009] The lower adjustable portion may be configured to pivot from a position that is parallel to the opposite wall of the fixed portion to a position that is slanted upwardly away from the opposite wall of the fixed portion.
[0010] The upper adjustable portion may be configured to remain in a position that is parallel to the opposite wall of the fixed portion during a pivoting of the lower adjustable portion.
[0011] The fixed portion may include a bottom floor disposed adjacent to the opposite wall of the fixed portion. One or more portions of the bottom floor may be perpendicular to the opposite wall of the fixed portion. The portions of the hinged outer wall configured to slant upwardly away from the opposite wall of the fixed portion may include a lower adjustable portion hinged to the bottom floor of the fixed portion. The bottom floor may be disposed between the lower adjustable portion and the opposite wall of the fixed portion.
[0012] The hinged outer wall may further include an upper adjustable portion hinged to the lower adjustable portion. The upper adjustable portion may be parallel to the opposite wall of the fixed portion and perpendicular to the portions of the bottom floor that are perpendicular to the opposite wall of the fixed portion.
[0013] The lower adjustable portion may be configured to pivot from a position that is parallel to the opposite wall of the fixed portion and perpendicular to the portions of the bottom floor that are perpendicular to the opposite wall of the fixed portion to a position that is slanted upwardly away from the opposite wall of the fixed portion and the portions of the bottom floor that are perpendicular to the opposite wall of the fixed portion.
[0014] The hinged outer wall may include an upper adjustable portion hinged to the lower adjustable portion. The upper adjustable portion may be parallel to the opposite wall of the fixed portion and perpendicular to the portions of the bottom floor that are perpendicular to the opposite wall of the fixed portion. The upper adjustable portion may be configured to remain parallel to the opposite wall of the fixed portion and perpendicular to the portions of the bottom floor that are perpendicular to the opposite wall of the fixed portion during the pivoting of the lower adjustable portion and a corresponding pivoting of the upper adjustable portion.
[0015] The lower adjustable portion may include a wall portion and a pair of wings disposed on opposite sides of the wall portion. Each of the wings may include a slot. The back wall of the dispenser interface may include a slot facing the storage. The fixed portion may include a slot facing the storage on a wall of the fixed portion that is opposite the back wall of the dispenser interface. The upper adjustable portion may include a plurality of posts. The slots may be configured to respectively receive the posts and allow the posts to move therein, thereby serving to pivot the lower adjustable portion from the position that is parallel to the opposite wall of the fixed portion to the position that is slanted upwardly away from the opposite wall of the fixed portion.
[0016] The lower adjustable portion may include a wall portion and a pair of wings disposed on opposite sides of the wall portion. Each of the wings may include a post. The back wall of the dispenser interface includes a post facing the storage. The fixed portion may include a post facing the storage on a wall of the fixed portion that is opposite the back wall of the dispenser interface. The upper adjustable portion may include a plurality of slots. The slots may be configured to respectively receive the posts and allow the posts to move therein, thereby serving to pivot the lower adjustable portion from the position that is parallel to the opposite wall of the fixed portion to the position that is slanted upwardly away from the opposite wall of the fixed portion.
[0017] In another general aspect, a refrigerator/freezer ice bucket may include a plurality of walls connected to each other. One or more of the walls may be adjustable. One or more of the walls may be fixed. One of the adjustable walls may be configured to pivot from a position that is parallel to a portion of the fixed walls to a position in which the one pivoting adjustable wall is fixed to be slanted upwardly away from the portion of the fixed walls, thereby expanding a capacity of the plurality of walls to store ice cubes.
[0018] One of the fixed walls may include a bottom floor that connects the adjustable walls to the fixed walls. The bottom floor may be perpendicular to the portion of the fixed walls.
[0019] Another one of the pivoting adjustable walls may be configured to pivot while remaining parallel with the portion of the fixed walls.
[0020] Another one of the pivoting adjustable walls may be configured to pivot while remaining parallel with the portion of the fixed walls and perpendicular to the bottom floor.
[0021] The parallel pivoting adjustable walls may include posts configured to fit slots of the slanting pivoting adjustable wall and the fixed walls.
[0022] In another general aspect, a refrigerator/freezer ice bucket may include a dispenser interface configured to deliver ice cubes to an ice dispenser upon a request by a user for the ice cubes. The dispenser interface may include a back wall. The ice bucket may further include storage configured to, with the back wall of the dispenser interface, store the ice cubes until the user request. The storage may include a fixed portion and a hinged outer wall. The fixed portion may be configured, with the back wall of the dispenser interface, to control a capacity of the storage to store the ice cubes by allowing the hinged outer wall to pivot.
[0023] The fixed portion may be further configured, with the back wall of the dispenser interface, to allow the hinged outer wall to pivot to a position in which one or more portions of the hinged outer wall are slanted upwardly away from the fixed portion to increase the capacity of the storage.
[0024] The fixed portion and the back wall of the dispenser interface may include slots through which posts of the hinged outer wall are allowed to move to cause the hinged outer wall to pivot, thereby adjusting the capacity of the storage.
[0025] The capacity of the storage may increase as a distance between the fixed portion and the hinged outer wall increases.
[0026] Other features and aspects may be apparent from the following detailed description, the drawings, and the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] FIG. 1A is a perspective view illustrating an example of a refrigerator/freezer ice bucket installed in a refrigerator/freezer unit.
[0028] FIG. 1B is a front view illustrating an example of the refrigerator/freezer ice bucket installed in the refrigerator/freezer unit.
[0029] FIG. 1C is a perspective view illustrating an example of a refrigerator/freezer ice bucket installed in a refrigerator/freezer unit in which the storage of the refrigerator/freezer ice bucket has been fully expanded.
[0030] FIG. 1D is a front view illustrating an example of the refrigerator/freezer ice bucket installed in the refrigerator/freezer unit in which the storage of the refrigerator/freezer ice bucket has been fully expanded.
[0031] FIG. 2 is a front view illustrating an example of the refrigerator/freezer ice bucket and its correspondence with an icemaker.
[0032] FIG. 3A is a perspective view illustrating an example of the refrigerator/freezer ice bucket.
[0033] . FIG. 3B is a side view illustrating an example of the refrigerator/freezer ice bucket.
[0034] FIG. 3C is a front view illustrating an example of the refrigerator/freezer ice bucket.
[0035] FIG. 3D is a rear view illustrating an example of the refrigerator/freezer ice bucket.
[0036] FIG. 3E is a perspective view illustrating an example of the refrigerator/freezer ice bucket installed in the icemaker.
[0037] FIG. 4A is a front perspective view illustrating an example of the refrigerator/freezer ice bucket in which the storage of the refrigerator/freezer ice bucket is in the midst of being expanded.
[0038] FIG. 4B is a rear perspective view illustrating an example of the refrigerator/freezer ice bucket in which the storage of the refrigerator/freezer ice bucket is in the midst of being expanded.
[0039] FIG. 4C is a front view illustrating an example of the refrigerator/freezer ice bucket in which the storage of the refrigerator/freezer ice bucket is in the midst of being expanded.
[0040] FIG. 4D is a rear view illustrating an example of the refrigerator/freezer ice bucket in which the storage of the refrigerator/freezer ice bucket is in the midst of being expanded.
[0041] FIG. 4E is a perspective view illustrating an example of the refrigerator/freezer ice bucket installed in the icemaker in which the storage of the refrigerator/freezer ice bucket is in the midst of being expanded.
[0042] FIG. 5A is a front perspective view illustrating an example of the refrigerator/freezer ice bucket in which the storage of the refrigerator/freezer ice bucket has been fully expanded.
[0043] FIG. 5B is a rear perspective view illustrating an example of the refrigerator/freezer ice bucket in which the storage of the refrigerator/freezer ice bucket has been fully expanded.
[0044] FIG. 5C is a front view illustrating an example of the refrigerator/freezer ice bucket in which the storage of the refrigerator/freezer ice bucket has been fully expanded.
[0045] FIG. 5D is a rear view illustrating an example of the refrigerator/freezer ice bucket in which the storage of the refrigerator/freezer ice bucket has been fully expanded.
[0046] FIG. 5E is a rear elevated view illustrating an example of the refrigerator/freezer ice bucket in which the storage of the refrigerator/freezer ice bucket has been fully expanded.
[0047] 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
[0048] Examples incorporating one or more aspects of the present invention are described and illustrated in the drawings. These illustrated examples are not intended to be limiting. For example, one or more aspects of the present invention may be utilized in other embodiments and even other types of devices.
[0049] Examples of the present invention may be applicable to a variety of buckets, drawers, and/or compartments in which expandable storage may be desired, such as, but not limited to, those storing vegetables, meats, fruits, deli items, or any other buckets, drawers, or compartments known by one having ordinary skill in the art to be applicable.
[0050] For purposes of the following descriptions and illustrations, a refrigerator/freezer unit is an electrically cooled compartment or a plurality of electrically cooled compartments combined into a single unit, where one or more of the cooled compartments has the ability to transform water from a liquid state to a solid (frozen) state and maintain the water in the solid (frozen) state by exposing the water to temperatures below a freezing point of water for an indeterminate period of time.
[0051] FIGS. 1A-1D are views illustrating an example of an ice bucket 100 in varied states of expansion installed in refrigerator/freezer unit 200 . FIGS. 1A and 1B illustrate the ice bucket 100 in a normal state. FIGS. 1C and 1D illustrated the ice bucket 100 fully expanded. FIG. 2 is a front view illustrating an example of the refrigerator/freezer ice bucket 100 and its correspondence with an icemaker 300 . FIGS. 3A-5E are views illustrating various examples of the refrigerator/freezer ice bucket 100 . FIGS. 3A-3E illustrate examples in which the storage in the ice bucket 100 has not been expanded. FIGS. 4A-4E illustrate examples in which the storage in the ice bucket 100 is in the midst of being expanded. FIGS. 5A-5E illustrate examples in which the storage in the ice bucket 100 has been fully expanded.
[0052] Referring to the examples illustrated in FIGS. 1A-5E , the ice bucket 100 is installed in the icemaker 300 of the refrigerator/freezer unit 200 and may include a dispenser interface 10 and storage 20 . The storage 20 may include a fixed portion 30 and an outer wall 60 . The outer wall 60 may include a lower adjustable portion 40 and an upper adjustable portion 50 .
[0053] The icemaker 300 may be mounted in the refrigerator/freezer unit 200 in a location that can accommodate an expansion of the outer wall 60 of the ice bucket 100 . The icemaker 300 may include a cavity 301 formed to slidably accept and hold the ice bucket 100 therein so that ice cubes made by the icemaker 300 can be delivered to the storage 20 of the ice bucket 100 . The outer wall 60 and a small area of the fixed portion 30 of the ice bucket 100 is substantially planar with a side of the icemaker 300 when the storage 20 is in a position of non
[0054] A bottom portion 11 of the dispenser interface 10 can mate with an upper portion of an ice dispenser (not shown) located on a door (not shown) of the refrigerator/freezer unit 200 such that, when ice cubes are requested by a user, ice cubes can be pulled from the storage 20 of the ice bucket 100 by an auger 70 . The auger 70 can pull the ice cubes through a front hole 31 in a front wall 32 of the fixed portion 30 . The ice cubes that are pulled through the front hole 31 in the front wall 32 of the fixed portion enter a cavity (not shown) in the dispenser interface 10 . The cavity of the dispenser interface 10 connects with the bottom portion 11 of the dispenser interface 10 , through which ice cubes are provided to the ice dispenser for delivery to the user.
[0055] The back wall 13 of the dispenser interface 10 may partially define a boundary of the storage 20 . The back wall 13 of the dispenser interface 10 may also include a curved slot 14 . The curved slot 14 may accept a front upper post 51 on a front winged part 57 of the upper adjustable portion 50 of the outer wall 60 and define a path in which the front upper post 51 can be moved.
[0056] The fixed portion 30 of the storage 20 may be defined by two parallel opposing walls disposed at a front 32 and a back 33 of the ice bucket 100 , a long wall 34 disposed perpendicularly to the front wall 32 and the back wall 33 , and a bottom floor 37 connecting the front wall 32 , the back wall 33 , and the long wall 34 . The bottom floor 37 may include one or more portions that are perpendicular to the front wall 32 , the back wall 33 , the long wall 34 , and one or more portions of the outer wall 60 including the upper adjustable portion 50 .
[0057] The long wall 34 may connect the front wall 32 and the back wall 33 at perpendicular angles. The front wall 32 may have an elevation that is less than an elevation of the back wall 33 . The front wall 32 may be disposed underneath and forward of the black wall 13 of the dispenser interface 10 . The fixed portion 30 may not have a wall that is disposed opposite the long wall 34 at an opposite side of the bottom floor 37 from the long wall 34 . As such, the outer wall 60 may be disposed opposite the long wall 34 at the opposite side of the bottom floor 37 from the long wall 34 . The front wall 32 of the fixed portion 30 may include the front hole 31 through which the auger 70 pulls ice cubes.
[0058] On an outer portion 131 of the long wall 34 , the bucket 100 may include a guide 130 . The guide 130 may be implemented as a ridge or a hook that extends horizontally along a substantially central portion of the outer portion 131 of the long wall 34 . The guide 130 can mate with a corresponding surface of the icemaker 300 to enable proper securing of the bucket 100 to the icemaker 300 . The guide 130 may also provide rigidity to the long wall 34 to enable the bucket 100 to withstand torque inflicted on the bucket 100 by operation of the auger 70 . As a result, the bucket 100 may be inhibited from warping of the bucket 100 that can be caused by repeated operation of the auger 70 .
[0059] A lower portion of the back wall 33 of the fixed portion 30 may include a back hole 35 through which an end of the auger 70 protrudes to be engaged with a shaft 305 of an auger motor (not shown) of the icemaker 300 . The shaft 305 operates the movement of the auger 70 to enable ice cubes to be pulled through the front hole 31 and delivered from the dispenser interface 10 to the ice dispenser (not shown).
[0060] A portion of the back wall 33 of the fixed portion 30 may include a small hole 39 . This small hole 39 may accept protrusions 303 on a back wall 304 of the icemaker 300 . The small hole 39 is configured to secure the bucket 100 to the icemaker 300 via the protrusions 303 . As a result, the bucket 100 may be inhibited from moving forward during operation of the auger 70 and warping that can be caused by torque being repeatedly applied to the bucket 100 because of operation of the auger 70 .
[0061] An upper portion of the back wall 33 of the fixed portion 30 may include a curved slot 36 formed opposite the curved slot 14 of the back wall 13 of the dispenser interface 10 . The curved slot 36 may have an elevation on the back wall 33 of the fixed portion 30 that is less than an elevation of the curved slot 14 on the back wall 13 of the dispenser interface 10 . The curved slot 36 may have a shape that corresponds with a shape of the curved slot 14 .
[0062] The curved slot 36 can accept a rear upper post 52 of a rear winged part 58 of the upper adjustable portion 50 and define a path in which the rear upper post 52 can be moved. The rear upper post 52 may have an elevation on the upper adjustable portion 50 that is less than an elevation of the front upper post 51 on the upper adjustable portion 50 . The elevations of the rear upper post 52 and the front upper post 51 may respectively correspond with the elevations of the curved slot 36 on the back wall 13 of the fixed portion and the curved slot 14 on the back wall 13 of the dispenser interface 10 . The movement of the rear upper post 52 in the curved slot 36 may mirror the movement of the front upper post 31 in the curved slot 14 . The rear upper post 52 may face in a direction that is opposite a direction that the front upper post faces. The front upper post 51 and the rear upper post 52 may both face away from a center of the ice bucket 100 .
[0063] The bottom floor 37 of the fixed portion 30 may have a plurality of hinge post acceptors 38 disposed at the opposite side of the bottom floor 37 from the long wall 34 . The lower adjustable portion 40 of the outer wall 60 can connect to the fixed portion 30 by way of a plurality of hinge posts 41 disposed on a lower edge 48 of the lower adjustable portion 40 . The hinge posts 41 may correspondingly mate with the hinge post acceptors 38 of the bottom floor 37 to allow the lower adjustable portion 40 to move while being connected to the bottom floor 37 .
[0064] The orientation of the hinge between the fixed portion 30 and the lower adjustable portion 40 is not limited to the example above. For example, the bottom portion 37 of the fixed portion 30 can have a plurality of hinge posts disposed at the opposite side of the bottom floor 37 from the long wall 34 . Further, the lower adjustable portion 40 of the outer wall 60 can connect to the fixed portion 30 by way of a plurality of hinge post acceptors disposed on the lower edge 48 of the lower adjustable portion 40 . The hinge post acceptors can correspondingly mate with the hinge posts of the bottom floor 37 to allow the lower adjustable portion 40 to move while being connected to the bottom floor 37 .
[0065] A front winged part 42 of the lower adjustable portion 40 may have a front curved slot 43 . An upper rear winged part 44 of the lower adjustable portion 40 may have a rear curved slot 45 . The front curved slot 43 on the front winged part 42 may be disposed opposite the rear curved slot 45 on the upper rear winged part 44 . The front curved slot 43 may have an elevation that is the same as an elevation of the rear curved slot 45 . The front curved slot 43 may have a shape that corresponds with a shape of the rear curved slot 45 .
[0066] The upper adjustable portion 50 may include a front lower post 53 and a rear lower post 54 respectively disposed on the front winged part 57 and the rear winged part 58 . The front curved slot 43 and the rear curved slot 45 can respectively accept the front lower post 53 and the rear lower post 54 of the upper adjustable portion 50 and define paths in which the front lower post 53 and the rear lower post 54 can be moved. The front lower post 53 may have an elevation on the upper adjustable portion 50 that is the same as an elevation of the rear lower post 54 on the upper adjustable portion 50 . The movement of the front lower post 53 in the front curved slot 43 may mirror the movement of the rear lower post 54 in the rear curved slot 45 . The front lower post 53 may face in a direction that is opposite a direction that the rear lower post 54 faces. The front lower post 53 and the rear lower post 54 may both face toward a center of the ice bucket 100 .
[0067] An upper edge 46 of the lower adjustable portion 40 may have a plurality of hinge post acceptors 47 . The hinge post acceptors 47 of the upper edge 46 may be disposed at an opposite side of the lower adjustable portion 40 from the hinge posts 41 disposed on the lower edge 48 of the lower adjustable portion 40 . The upper adjustable portion 50 may connect to the lower adjustable portion by way of a plurality of hinge posts 55 disposed on a lower edge 59 of the upper adjustable portion 50 . The hinge posts 55 correspondingly mate with the hinge post acceptors 47 to allow the lower adjustable portion 40 to move while being connected to the upper adjustable portion 50 .
[0068] The orientation of the hinge between the lower adjustable portion 40 and the upper adjustable portion 50 is not limited to the example above. For example, an upper edge 46 of the lower adjustable portion 40 can have a plurality of hinge posts. The hinge posts of the upper edge 46 can be disposed at an opposite side of the lower adjustable portion 40 from the hinge posts 41 disposed on the lower edge 48 of the lower adjustable portion 40 . The upper adjustable portion 50 can connect to the lower adjustable portion by way of a plurality of hinge post acceptors disposed on a lower edge 59 of the upper adjustable portion 50 . The hinge post acceptors can correspondingly mate with the hinge posts to allow the lower adjustable portion 40 to move while being connected to the upper adjustable portion 50 .
[0069] The slots 14 , 36 , 43 45 respectively serve to guide the posts 51 , 52 , 53 , 54 of the upper adjustable portion 50 along a specific course. The slots 14 , 36 , 43 , 45 may be oriented to provide the posts 51 , 52 , 53 , 54 with room to move along the specific course. In addition, the slots 13 , 36 , 43 , 45 may be oriented to inhibit any movement by the posts 51 , 52 , 53 , 54 that would serve to adjust a parallel relationship between the upper adjustable portion 50 and the long wall 34 of the fixed portion 30 . In other words, while the upper adjustable portion 50 may be pivoted through interaction with the slots 13 , 36 , 43 , 45 and the posts 51 , 52 , 53 , 54 to allow an angular relationship with the lower adjustable portion 40 to change, the slots 13 , 36 , 43 , 45 and the posts 51 , 52 , 53 , 54 may be oriented such that a parallel relationship between the upper adjustable portion 50 and the long wall 34 of the fixed portion 30 never changes. Further, a plane in which the upper adjustable portion 50 resides may remain parallel to a plane in which the long wall 34 resides during any movement of the upper adjustable portion 50 and the lower adjustable portion. Moreover, any movement of the upper adjustable portion 50 and the lower adjustable portion 40 may alter angles between the lower adjustable portion 40 and both the upper adjustable portion 50 and the bottom floor 37 .
[0070] The upper adjustable portion 50 may have a notch 56 that enables a user of the refrigerator/freezer unit 200 to expand the ice bucket 100 by grabbing the upper adjustable portion 50 around the notch 56 and subsequently pulling the upper adjustable portion 50 via the notch 56 in a direction away from the long wall 34 . When the ice bucket 100 is in a state of non-expansion and a user wishes to move the ice bucket to a state of full expansion, the user may pull the grabbed upper adjustable portion 50 in the direction away from the long wall 34 . This pulling may serve to initiate movement of each of the posts 51 , 52 , 53 , 54 with respect to each of the slots 14 , 36 , 43 , 45 until the posts 51 , 52 , 53 , 54 are at a respective position in the slots 14 , 36 , 43 , 45 that is at an opposite end of slots 14 , 36 , 43 , 45 from which the posts 51 , 52 , 53 , 54 began movement. In other words, the user's initiation of movement of the posts 51 , 52 , 53 , 54 with respect to each of the slots 14 , 36 , 43 , 45 by pulling may bring the ice bucket 100 to a state of full expansion from the state of non-expansion.
[0071] When a user wishes to move the ice bucket 100 from the state of full expansion back to the state of non-expansion, a used can grab the upper adjustable portion 50 around the notch 56 and subsequently push the upper adjustable portion 50 in a direction toward the long wall 34 . This pushing may serve to initiate movement of each of the posts 51 , 52 , 53 , 54 with respect to each of the slots 14 , 36 , 43 , 45 until the posts 51 , 52 , 53 , 54 are at a respective position in the slots 14 , 36 , 43 , 45 that is at an opposite of the slots 14 , 36 , 43 , 45 from which the posts 51 , 52 , 53 , 54 began movement. In other words, the user's initiation of movement of the posts 51 , 52 , 53 , 54 with respect to each of the slots 14 , 36 , 43 , 45 by pushing may bring the ice bucket 100 from the state of full expansion to the state of non-expansion.
[0072] It should be noted that, when ice buckets are actively being stored by an ice bucket 100 in the state of full expansion, depending on a volume and weight of ice cubes being stored in the ice bucket 100 , the user may be inhibited from pushing the ice bucket 100 to the state of non-expansion. A volume and weight of ice cubes in the ice bucket 100 at a time in which the ice bucket 100 is in a state of non-expansion may serve to facilitate the expansion of the ice bucket 100 when the notch 56 is used to pull the upper adjustable portion 50 in the direction away from the long wall 34 .
[0073] When the ice bucket 100 is in the state of non-expansion, the lower adjustable portion 40 may be at its highest elevation. When the ice bucket 100 is in the state of full expansion, the lower adjustable portion 40 may be at its lowest elevation.
[0074] When the ice bucket 100 is in the state of non-expansion, a plane in which the lower adjustable portion 40 resides may be parallel to the plane in which the long wall 34 resides. When the ice bucket 100 is in the state of full expansion, a plane in which the lower adjustable portion 40 resides may not be parallel to the plane in which the long wall 34 resides.
[0075] When the ice bucket 100 is in the state of non-expansion, the posts 51 , 52 , 53 , 54 may be at their highest elevation. When the ice bucket 100 is in the state of full expansion, the posts 51 , 52 , 53 , 54 may be at their lowest elevation.
[0076] When the ice bucket 100 is in the state of non-expansion, the front upper post 51 and the rear upper post 52 may be at their closest to the long wall 34 , and the front lower post 53 and the rear lower post 54 may be at their farthest from the long wall 34 . When the ice bucket 100 is in the state of full expansion, the front upper post 51 and the rear upper post 52 may be at their farthest from the long wall 34 , and the front lower post 53 and rear lower post 54 may be at their closest to the long wall 34 .
[0077] The orientation of the slots and posts of the ice bucket 100 is not limited to the examples described above. For example, the posts 51 , 52 , 53 , 54 of the upper adjustable portion 50 can be replaced with slots depending on an expanded size of the front winged part 57 and the rear winged part 58 . Correspondingly, slots 13 , 36 , 43 , and 45 can be replaced with posts that can be received by the slots provided in the expanded front winged part 57 and the expanded rear winged part 58 .
[0078] In addition, various prongs, posts, clips, receptacles, and similar mechanisms known to one having ordinary skill in the art may be implemented on the lower adjustable portion 40 and/or the upper adjustable portion 50 so that the ice bucket 100 may be placed in a state of partial expansion. Moreover, various prongs, posts, clips, receptacles, and similar mechanisms known to one having ordinary skill in the art may be implemented on the lower adjustable portion 40 and/or the upper adjustable portion 50 so that the ice bucket 100 may be locked in the state of non-expansion, the state of partial expansion, or the state of full expansion.
[0079] 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 elements are combined in a different manner and/or replaced or supplemented by other elements or their equivalents. Accordingly, other implementations are within the scope of the following claims.
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A refrigerator/freezer ice bucket is provided. The ice bucket may include a dispenser interface configured to deliver ice cubes to an ice dispenser upon a request by a user for the ice cubes. The dispenser interface may include a back wall. The ice bucket may further include storage configured to, with the back wall of the dispenser interface, store the ice cubes until the user request. The storage includes a fixed portion and a hinged outer wall. The hinged outer wall is configured to pivot from a position that is parallel to an opposite wall of the fixed portion to a position in which one or more portions of the hinged outer wall are fixed to be slanted upwardly away from the opposite wall of the fixed portion, thereby expanding a capacity of the storage.
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REFERENCE TO RELATED APPLICATIONS
This is a continuation of U.S. application Ser. No. 11/715,579, filed Mar. 7, 2007 now U.S. Pat. No. 7,947,080, which is a divisional of U.S. application Ser. No. 10/630,445, filed Jul. 30, 2003 now U.S. Pat. No. 7,273,497, which is a continuation of U.S. application Ser. No. 09/638,241, filed Aug. 14, 2000 now abandoned, which claims the benefit of U.S. Provisional Patent Application Ser. No. 60/148,913, filed Aug. 13, 1999. U.S. application Ser. No. 09/638,241 is also a continuation-in-part of International Patent Application No. PCT/US00/14708, filed May 30, 2000, which is a continuation-in-part and claims the benefit under 35 U.S.C. §119 of U.S. application Ser. No. 09/322,516, filed May 28, 1999, now U.S. Pat. No. 6,245,107. The entire content of each application and patent is incorporated herein by reference.
FIELD OF THE INVENTION
This invention relates generally to the prosthetic appliances and, in particular, to devices for occluding intervertebral disc defects and instrumentation associated with introducing the such devices.
BACKGROUND OF THE INVENTION
Several hundred thousand patients undergo disc operations each year. Approximately five percent of these patients will suffer recurrent disc herniation, which results from a void or defect which remains in the outer layer (annulus fibrosis) of the disc after surgery involving partial discectomy.
Reference is made to FIG. 1A , which illustrates a normal disc as viewed from the feet of a patient up toward the head. The nucleus pulposus 102 is entirely surrounded by the annulus fibrosis 104 in the case of healthy anatomy. Also shown in this cross section is the relative location of the nerves 106 . FIG. 1 B illustrates the case of the herniated disc, wherein a portion of the nucleus pulposus has ruptured through a defect in the annulus fibrosis, resulting in a pinched nerve 110 . This results in pain and further complications, in many cases.
FIG. 1C illustrates the post-operative anatomy following partial discectomy, wherein a space 120 remains adjacent a hole or defect in the annulus fibrosis following removal of the disc material. The hole 122 acts as a pathway for additional material to protrude into the nerve, resulting in the recurrence of the herniation. Since thousands of patients each year require surgery to treat this condition, with substantial implications in terms of the cost of medical treatment and human suffering, any solution to this problem would welcomed by the medical community.
SUMMARY OF THE INVENTION
The subject invention resides in methods and apparatus for treating disc herniation, which may be defined as the escape of nucleus pulposus through a void or defect in the annulus fibrosis of a spinal disc situated between upper and lower vertebra. In addition to preventing the release of natural disc materials, the invention may also be used to retain bone graft for fusion, therapeutic and artificial disc replacement materials. The invention is particularly well suited to the minimization and prevention of recurrent disc herniation, in which case the defect is a hole or void which remains in the annulus fibrosis following disc operations involving partial discectomy.
In broad, general terms, to correct defects of this type, the invention provides a conformable device which assumes a first shape associated with insertion and a second shape or expanded shape to occlude the defect. The device may take different forms according to the invention, including solidifying gels or other liquids or semi-liquids, patches sized to cover the defect, or plugs adapted to fill the defect.
The device is preferably collapsible into some form for the purposes of insertion, thereby minimizing the size of the requisite incision while avoiding delicate surrounding nerves. Such a configuration also permits the use of instrumentation to install the device, including, for example, a hollow tube and a push rod to expel the device or liquefied material out of the sheath for use in occluding the disc defect.
A device according to the invention may further include one or more anchors to assist in permanently affixing the device with respect to the defect. For example, in the embodiment of a mesh screen, the anchors may assume the form of peripheral hooks configured to engage with the vertebra on either side of the disc. The invention further contemplates a distracting tool used to force the anchors into the vertebra. Such a tool would preferably feature a distal head portion conformal to the expanded shape of the device, enabling the surgeon to exert force on the overall structure, thereby setting the anchors.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a cross section of a human disc exhibiting normal anatomy;
FIG. 1B is a cross section used to illustrate a disc herniation;
FIG. 1C is a drawing of a disc following a partial discectomy, showing how a space or void remains in the annulus fibrosis;
FIG. 2 is a drawing which illustrates a preferred embodiment of the invention in the form of a flexible stent used to occlude a defect in the annulus fibrosis to minimize recurrent disc herniation;
FIG. 3A is a drawing of an applicator used to insert the flexible mesh stent embodiment of FIG. 2 ;
FIG. 3B shows the applicator of FIG. 3A with the stent partially expelled;
FIG. 3C illustrates a fully expanded shape assumed by the device of FIG. 2 following removal of the insertion tool;
FIG. 4A illustrates the addition of optional peripheral anchors around the stent in the FIG. 4 to assist in fixation;
FIG. 4B is an end view of the device of FIG. 4A including the peripheral anchors;
FIG. 5 is a side-view drawing of the device of FIGS. 4A and 4B anchored into upper and lower vertebra bounding the herniated disc;
FIG. 6A illustrates an optional distraction tool used to set the anchors of the device of FIGS. 4 and 5 into the vertebra;
FIG. 6B shows how the distracting tool would be inserted into the device to effectuate distraction;
FIG. 7A is a side-view drawing in partial cross-section illustrating the way in which notches may be made to adjoining vertebra to receive a device according to the invention;
FIG. 7B is a drawing of a tool which may be used to form the notches depicted in FIG. 7A ;
FIG. 7C illustrates the way in which a flexible body may be retained by the notches described with respect to FIGS. 7A and 7B ;
FIG. 8 illustrates an alternative orientation of a flexible body having a convex surface facing outwardly with respect to the wall of the disc being repaired;
FIG. 9A illustrates how the device according to the invention may be fixed with anchors that penetrate through the disc to be captured at the outer wall thereof;
FIG. 9B illustrates an alternative use of anchors which remain within the body of the disc material and do not penetrate its outer wall;
FIG. 9C illustrates an alternative method of fixation, wherein bone anchors are introduced into the vertebrae on either side of the disc in need of repair, as opposed to anchors deployed within or through the disc itself;
FIG. 10 illustrates an alternative device according to the invention in the form of a resilient plug;
FIG. 11A illustrates an alternative embodiment of the invention wherein a coiled wire is used to occlude a disc defect;
FIG. 11B is a side-view representation of the coiled wire of FIG. 11 A;
FIG. 11C illustrates how a wire with a coiled memory shape may be straightened and introduced using a plunger-type instrument;
FIG. 12 illustrates yet a different alternative embodiment of the invention wherein a material in liquid or gel form may be introduced into a defect, after which it hardens or solidifies to prevent further rupturing;
FIG. 13A illustrates yet a further alternative embodiment of the invention, in the form of a stent having a plurality of leaves;
FIG. 13B illustrates the alternative of FIG. 13A , wherein the leaves assume a second shape associated with defect occlusion, preferably through memory affect;
FIG. 14A illustrates an aspect of the invention wherein a conformable device is suspended within a gel or other resilient material for defect occlusion;
FIG. 14B is a side-view drawing of the embodiment of FIG. 14A ;
FIGS. 15A-15E are drawings which show various different alternative embodiments according to the invention wherein a patch is used inside and/or outside of a void in need of occlusion;
FIG. 16A is a top-view, cross-sectional drawing of a version of the invention utilizing posts or darts and sutures;
FIG. 16B is a side-view drawing of the embodiment of FIG. 16A ;
FIG. 17A shows how posts or darts may be criss-crossed to form a barrier;
FIG. 17B is a side-view drawing of the configuration of FIG. 17A ;
FIG. 18A is a side-view drawing of a barbed post that may be used for occlusion according to the invention;
FIG. 18B is an on-access view of the barbed post;
FIG. 18C illustrates how a single larger barbed post may be used for defect occlusion;
FIG. 18D illustrates how the barbed post of FIGS. 18A and 18B may be used in plural fashion to occlude a defect;
FIG. 19A is a drawing which shows how shaped pieces may be inserted to close off an opening;
FIG. 19B continues the progression of FIG. 19A , with the pieces being pulled together;
FIG. 19C illustrates the pieces of FIGS. 19A and 19B in a snapped-together configuration;
FIGS. 20A-20E are a progression of drawings which show how a shaped body may be held into place with one or more wires to block off a defect;
FIGS. 21A-21C illustrate how wires may be used in conjunction with snap-on beads to occlude a defect;
FIG. 22A illustrates the insertion of members adapted to receive a dam component;
FIG. 22B illustrates the dam of FIG. 22A locked into position;
FIG. 23A illustrates one form of defect block that accommodates compression and distraction;
FIG. 23B shows the device of FIG. 23A in compression;
FIG. 23C shows the device of FIG. 23A in distraction;
FIG. 23D illustrates the way in which the device of FIGS. 23A-23C , and other embodiments, may be tacked into place with respect to upper and lower vertebrae;
FIG. 24A is a drawing which shows an alternative device that adjusts for compression and distraction, in the form of a resilient dam,
FIG. 24B shows the resilient dam in compression;
FIG. 24C shows the resilient dam in distraction;
FIG. 25 illustrates a different configuration for the insertion of a resilient dam according to the invention;
FIG. 26 illustrates an alternative Z-shaped dam of resilient material;
FIG. 27A illustrates the use of interlocking fingers that permit compression and distraction while occluding a defect;
FIG. 27B is a side-view drawing in cross-section of the configuration of FIG. 27 ;
FIG. 28A illustrates an alternative interlocking finger configuration, and the way in which such members are preferably installed;
FIG. 28B shows how the first of the multiple members of FIG. 28A is installed;
FIG. 29A is a side-view drawing of a non-contained silicon blocking member prior to distraction;
FIG. 29B illustrates the way in which the device of FIG. 29A deforms upon distraction;
FIG. 30A is a side-view drawing in cross-section illustrating a contained silicon structure prior to distraction;
FIG. 30B illustrates how the contained silicon structure of FIG. 30A remains essentially the same in shape upon distraction;
FIG. 31A illustrates the use of threaded metal plug with particular applicability to bone graft retention;
FIG. 31B illustrates a rigid plug with ridges enabling it to be impacted into place;
FIG. 31C shows the use of asymmetric ridges to resist posterior migration;
FIG. 31D shows how teeth, screw threads or ridges on certain plug embodiments would extent at least partially into the adjacent vertebra for secure purchase; and
FIG. 32 illustrates bilateral plug positioning according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
Having discussed the problems associated with post-operative partial discectomy with respect to FIGS. 1A-1C , reference will now be made to FIG. 2 , which illustrates a preferred embodiment of the invention, wherein a device in the form of a stent 202 is used to occlude a defect 204 in a human disc, as shown. In this preferred embodiment, the device is composed of a flexible material, which may be cloth, polymeric or metallic. For reasons discussed below, a titanium mesh screen is preferred with respect to this embodiment of the invention.
A flexible device is also preferred because the surgeon is presented with a very small working area. The incision through the skin is typically on the order of 1 to 1.5 inches in length, and the space at the disc level is approximately 1 centimeter on the side. As a consequence, the inventive device and the tools associated with insertion and fixation described below must be sufficiently narrow to fit within these confines.
As shown in FIGS. 3A-3C , a flexible screen enables the device to be collapsed into an elongated form 302 , which, in turn, facilitates introduction into a sheath 304 associated with insertion. A push rod 306 may then be introduced into the other end of the sheath 304 , and either the sheath pulled backwardly or the push rod pushed forwardly, or both, resulting in the shape shown in FIG. 3C , now suitable for implantation.
To further assist in fixation with respect to the surrounding physiology, anchors 402 may be provided around a peripheral edge of the device, as shown in FIG. 4A . FIG. 4B shows an end view of the device of FIG. 4A , and FIG. 5 illustrates the device with anchors generally at 500 , being fixed relative to a defective disc 504 bounded by upper and lower vertebrae at 502 . It will be apparent to those of skill that each of the devices disclosed herein may be made in different sizes, having varying peripheral dimensions, for example, to match differently sized defects.
FIGS. 6A and 6B illustrate how a distracting tool 602 may be used to force the anchors into the vertebrae. That is, having introduced the device into the approximate area, the tool 602 , having a forward shape corresponding to that of the expanded mesh shape, may be introduced therein, as shown in FIG. 6B . With force being applied to the tool 602 , the anchors may be permanently set into the surrounding bone/tissue.
FIG. 7A illustrates an alternative approach to fixation, wherein one or more notches 700 may be made into the upper and lower vertebra, preferably through the use of an air-operated drill 704 shown in FIG. 7B , having a cutting wheel 702 adapted for such a purpose. FIG. 7C illustrates the way in which a flexible body 708 may be retained by the notches 700 described with respect to FIGS. 7A and 7B . FIG. 8 illustrates an alternative orientation of a flexible body having a convex surface facing outwardly with respect to the wall of the disc being repaired.
FIG. 9A illustrates a further alternative associated with fixation wherein anchors 902 which penetrate the outer wall of the disc 905 are used to hold a flexible repair device 900 in place as shown. FIG. 9B shows yet a further alternative fixation modality, wherein disc anchors 906 , which do not penetrate the outer wall of the disc, but, rather remain there within, are used to hold the device 904 in place.
FIG. 9C illustrates yet a further alternative mode of fixation, wherein anchors 908 are used to hold the device to upper and lower vertebra, as opposed to the anchors of FIGS. 9A and 9B , which are used with respect to the disc. Regardless of whether fixation takes place within the vertebra or within the disc, it will be noted that according to the preferred embodiment of the invention, both the device used to occlude the defect and the fixation means are sufficiently flexible that the defect remains occluded with movement of the spine, that is, with the patient leaning forwardly and backwardly which will tend to change the spacing between the upper and lower vertebra.
FIG. 10 illustrates yet a different embodiment of the invention wherein, as opposed to a piece of flexible material or mesh, a resilient plug 1002 is instead utilized to occlude the disc defect. As in the case of the flexible sheath-like embodiments described above, such plugs are preferably offered in different sizes to correlate with differently sized defects.
In terms of a preferred material, a device according to the invention will therefore remain sufficiently flexible during movement while being capable of exerting continuous outward forces and withstanding repetitive compression and distraction of millions of cycles. The device would, therefore, preferably be made of a material that has these characteristics, while, additionally being radio-opaque for X-ray imaging, without producing too many unwanted artifacts in magnetic resonance imaging. A wire mesh of titanium is therefore preferable, since this has the proper X-ray/MRI characteristics while exhibiting the requisite flexibility for the cyclic flexion and extension. With respect to the embodiment of FIG. 10 , a resilient, rubber-like material may be used to occlude the defect as shown in the drawing from a side-view perspective.
The invention is not limited in the sense that any conformable device may be used with a first shape permitting the device to be introduced into the defective area and a second shape wherein the device includes a defect. As shown in FIGS. 11A-11C , for example, a wire 1102 having a “memory effect” may be used, preferably having a final diameter which is larger than void 1104 . FIG. 11 B shows the coil 1102 in cross-section between upper and lower vertebra. Preferably, this embodiment would use a metal wire that may be straightened, but retain the memory of its coiled shape. As such, the apparatus of FIG. 11C may be used to introduce the wire in straightened form 1108 with a plunger 1110 , such that as the wire exits at 1106 , it returns to its memorized state of a coil (or alternative second shape operative to include the defect).
As yet a different alternative mode of introduction, a material may be injected into the disc in liquid form, then allowed to hardened into a size sufficient to occlude the annular hole. As shown in FIG. 12 , material 1202 may be injected into the void of the disc space using a plunger 1204 inserted into a tube 1206 . Upon introduction in this manner, the liquid would then solidify, forming a resilient plug.
Various materials may be utilized for this purpose, including various polymers which are caused to solidify by various means, including thermal or optical activation, or chemical reaction as part of multi-part compounds. A preferred material with respect to this embodiment would be a hydrogel. Hydrogels may be placed into the disc in a dehydrated state, and, once inside the disc, they imbibe water. After hydration, hydrogels have the same biomechanical properties as a natural nucleus and, in addition, as the hydrogels swell, they become too large to extrude back through the annular window. U.S. Pat. Nos. 5,047,055 and 5,192,326 provide a listing of hydrogels, certain of which are applicable to this invention.
An elastomer may be used as an alternative to a hydrogel or other material. A number of elastomers may be suited to the invention, including a silicon elastomer, which comprises a cured dimethylsiloxane polymer and Hexsyn, having a composition of one-hexane with three to five percent methylhexaiene. A preformed elastomer may be inserted into the inclusion upon curing or, alternatively, as discussed with reference to FIG. 12 , may be injected into the disc space and liquid form. Chemicals may be added to accelerate curing, as discussed above, or, a hot or cold probe, or UV light may be introduced to facilitate or accelerate the curing process. Preferably, such materials would include a radio-opaque additive which would enable the physician to verify the position of the implant with an X-ray. Ideally, the radio-opaque additive would not change the mechanical properties of the gel or elastomer, and would ideally incorporate contrast throughout to enhance detail.
Now making to FIGS. 13 and 14 , FIGS. 13A and 13B illustrate an alternative type of stent having leaves or other appendages that may be folded into a compact state for insertion, FIG. 13A , and which expand, through memory affect, for example, to a state such as that shown in FIG. 13B . A stent such as this, as well as other devices disclosed herein such as the coil form of FIG. 11 , may be used in conjunction with a gel or other void-filling material as described above. As shown in FIG. 14A , a stent 1402 of the type shown with respect to FIG. 13B , may be introduced into the void, after which the remaining volume of the void may be filled with a material 1404 which solidifies into a resilient material. FIG. 14B is a side-view drawing of the embodiment of FIG. 14A . An expandable stent of this kind may be incorporated into the elastomer or other resilient material to help prevent migration of the prosthesis through the annular hole. In contrast to embodiments of the invention wherein a stent is used independently, in this particular embodiment, the stent would preferably not touch vertebra, since it would be surrounded entirely by the elastomer or other gel material.
FIGS. 15A-15E illustrate various alternative embodiments according to the invention wherein a patch material is used inside, outside, or partially inside and outside of a defect to be blocked. FIG. 15A illustrates a flat patch attached onto the outside of the disc. FIG. 15B illustrates a patch attached on the outside but wherein a central portion extends inwardly into the void. FIG. 15C illustrates a patch disposed within the disc to block the defect. FIG. 15D illustrates how a patch may be anchored to the bone above and below the disc, and FIG. 15E illustrates how the patch may be anchored to the disc itself. The patch material be a fiber, including natural materials, whether human, non-human or synthetic; an elastomer; plastic; or metal. If a fiber material is used, it may be selected so as to promote tissue in-growth. Growth of a patient's tissue into the material would assure a more permanent closure of the annular window. The patch may be attached within appropriate means, including stitches, staples, glue, screws or other special anchors.
In addition to the use of patches attached with sutures, staples or other materials, the annular defect may be closed with staples or other devices which attach to the annulus without the need for patch material. For example, as shown in FIG. 16A , darts 1602 may be inserted through the wall of the annulus 1604 , then linked with sutures 1606 , preferably in woven or criss-crossed fashion, as shown in FIG. 16B . As an alternative, appropriately shaped darts 1702 may be criss-crossed or otherwise interlocked to the close the annular hole, as shown in the top-view cross-section drawing of FIG. 17A or a side-view of FIG. 17B .
The use of flexible stents as described elsewhere herein may take on other forms, as shown in FIGS. 18A-18D . The device of FIG. 18A , for example, preferably includes a body 1802 , preferably including a blunt anterior end to prevent penetration of the anterior annulus, and outer spikes 1806 , preferably having different lengths, as best seen in the on-axis view of FIG. 18B . Such a stent configuration may provide more areas of contact with the vertebral end plates, thereby decreasing the chances of stent extrusion. As shown in FIG. 18C , the longer spikes 1806 are configured to bend during insertion, thereby preventing posterior extrusion. The shorter spikes, 1806 ′, are sized so as not to engage the vertebrae, and therefore may be made thicker to prevent deflection by disc material. As an option, the shorter spikes 1806 ′ may also be angled in the opposite direction as compared to the longer spikes 1806 to resist migration of the disc material. As yet a further option, the longer spikes may vary in length on the same stent so as to be conformal to the vertebral end plate concavity. As shown in FIG. 18D , multiple spike stents of this kind may be inserted so as to interlock with one another, thereby preventing migration of the group.
As shown in FIGS. 19A-19C , shapes other than spiked stents may be used in interlocking fashion. In FIG. 19A , a first piece 1902 is inserted having a removable handle 1904 , after which pieces 1902 ′ and 1902 ″ are inserted, each having their own removable handles, as shown. In FIG. 19B , the handles are pulled, so as to bring the pieces together, and in FIG. 19C , the handles are removed, and the pieces are either snapped together or, through the use of suitable material, sutured into place. FIGS. 20A-20E illustrate a different configuration of this kind, wherein a body 2002 having anchor or wire-receiving apertures 2004 is inserted into the annular hole, as shown in FIG. 20B , at which time a wire 2006 is inserted through the body 2002 as shown in FIG. 20C . As shown in FIG. 20D , the wire is installed sufficient to lock one portion of the body into place, and this is followed with a wire on the opposite side, thereby holding the body 2002 in a stabilized manner. It will be appreciated that although multiple wires or anchors are used in this configuration, bodies configured to receive more or fewer wires or anchors are also anticipated by this basic idea.
FIGS. 21A-21C illustrate a different alternative, wherein wires 2102 each having a stop 2104 are first inserted through the annular window, after which blocking beads having snap-in side configurations are journaled onto the wire across the annular hole, as shown in FIG. 21B . FIG. 21C illustrates how, having locked multiple beads onto the wire, the defect is affectively occluded. FIGS. 22A and 22B illustrate the use of a removable dam component. As shown in FIG. 22A , bodies 2202 , each having removable handles 2204 , are first inserted on the side portions of the defect, each member 2202 including slots, grooves or apertures 2206 , configured to receive a dam 2210 , which may be made of a rigid or pliable material, depending upon vertebral position, the size of the defect, and other factors. FIG. 22B illustrates the dam 2210 locked in position.
Certain of the following embodiments illustrate how the invention permits the use of a flexible device which allows movement between the vertebrae yet blocks extrusion of nucleus through an annular hole or defect. In FIG. 23A , for example, a flexible element 2302 is tacked into position on the upper vertebrae, as perhaps best seen in FIG. 23D , though it should be apparent that a fixation to the lower vertebrae may also be used. FIG. 23B illustrates how, once the member 2302 is fastened in place, it may flex under compression, but return to a more elongated shape in distraction, as shown in FIG. 23C . The blocking element 2302 may be made from various materials, including shape-memory materials, so long as it performs the function as described herein. FIG. 24A illustrates a different configuration, which is tacked to both the upper and lower vertebrae, and FIGS. 24B and 24C show how the device performs in compression and distraction, respectively. Since devices attached to both the upper and lower vertebrae need not automatically assume a memorized shape, alternative materials may preferably be used, including biocompatible rubbers and other pliable membranes. It is important that the flexible member not be too redundant or stretched so as to compress the nerve, as shown in FIG. 25 . FIG. 26 illustrates an alternative Z-shaped installation configuration.
As an alternative to inherently flexible materials which occlude a defect while accommodating compression and distraction, interleaving members may alternatively be used, as shown in FIGS. 27-28 . FIG. 27A is a view from an oblique perspective, showing how upper and lower plate 2702 and 2704 of any suitable shape, may be held together with springs 2706 , or other resilient material, between which there is supported interleaving tines 2708 . As better seen in FIG. 27B , the springs 2706 allow the upper and lower plates 2702 and 2704 to move toward and away from one another, but at all times, tines 2708 remain interleaving, thereby serving to block a defect.
FIGS. 28A and 28B illustrate the way in which interleaving members or tines are preferably inserted directly to vertebrae. Since each member overlaps with the next, such tines are preferably installed from front to back (or back to front, as the case may be), utilizing a tool such as 2810 , as shown in FIG. 28B . The instrument 2810 forces each tack into one vertebrae at a time by distracting against the other vertebrae, thereby applying pressure as the jaws are forced apart, driving the tack into the appropriate vertebrae. The tack may be held into place on the instrument by a friction fit, and may include a barbed end so as not to pull out following insertion.
As a further alternative configuration, a collapsed bag may be placed into the disc space, then filled with a gas, liquid or gel once in position. The bag may be empty, or may contain a stent or expanding shape to assist with formation. In the case of a gel, silicon may be introduced so as to polymerized or solidify. As shown in FIGS. 29A and 29B , the us of a non-contained silicon vessel may be used, but, under distraction, may remain in contact with the vertebrae, thereby increasing the likelihood of a reaction to silicone. The invention therefore preferably utilizes a contain structure in the case of a silicon filler, as shown in FIG. 30A , such that, upon distraction, the vessel remains essentially the same shape, thereby minimizing vertebral contact.
It is noted that, depending upon the configuration, that the invention may make use of a bioabsorbable materials, that is, materials which dissolve in the body after a predetermined period of time. For example, if darts such as those shown in FIGS. 16 and 17 are used, they may bioabsorb following sufficient time for the in-growth of recipient tissue sufficient to occlude the defect independently. Any of the other configurations described herein which might not require certain components in time may also take advantage of bioabsorbable materials. Furthermore, although the invention has been described in relation to preventing the release of natural disc materials, the invention may also be used to retain bone graft for fusion; therapeutic materials including cultured disc cells, glycosaminoglycans, and so forth; and artificial disc replacement materials.
Disc fusions are generally performed for degenerative disc disease, spondylolysis (a stress fracture through the vertebra), spondylolisthesis (slippage of one vertebra on another), arthritis of the facet joints, spinal fractures, spinal tumors, recurrent disc herniations, and spinal instability. The procedure attempts to eliminate motion between vertebra to decrease a patient's pain and/or prevent future problems at the intervertebral level.
Devices such as spinal cages are generally used in conjunction with such procedures to maintain the separation between the vertebrae until fusion occurs. Some surgeons believe that cages are not necessary to maintain the separation, and instead use pedicle screws or hooks and rods to perform this function. Whether or not a cage is used, bone graft is generally introduced through a hole formed in the disc space to achieve an interbody fusion.
Unfortunately, bone material placed into the disc space can extrude through the hole used for insertion. Bone graft extruded through a hole in the posterior portion of the disc may cause nerve root impingement. The procedure to fuse vertebra across the disc space from a posterior approach is known as a PLIF (posterior lumbar interbody fusion). Bone can also be placed into the disc space from an anterior approach ALIF (anterior lumbar interbody fusion). Extruded bone from an anterior approach would not lead to nerve impingement but could decrease the likelihood of a successful fusion by decreasing the volume of bone graft.
The present invention may be used to prevent the loss of the bone graft material associated with fusion techniques, whether or not a cage is used. In this particular regard, however, some of the devices disclosed herein may be more suitable than others. Generally speaking, since the goal is not to preserve disc function and motion, the stent, plug, and patch embodiments may be more appropriate. Although the plug embodiment would be a good choice when there is ample room in the spinal canal to allow insertion, the expandable stent design would be beneficial when plug insertion risks nerve injury. Conversely, since the goal is to maximize the amount of bone inserted into the disc space, the embodiments using hydrogels and elastomers might not be optimum, since such materials may occupy too much space in some circumstances.
The preferred choice of materials may also be changed since motion is not being maintained. Materials and designs with shape memory may be beneficial. As another example, the polymer plug embodiment may changed to a metal such as titanium. A metal plug may be fabricated with threads and screwed into place, as shown in FIG. 31A , or the device may feature ridges and be impacted into place ( FIG. 31B ). As shown in FIG. 31C , the ridges may also be asymmetric to resist posterior migration. In all cases, the teeth, screw threads or ridges would extent at least partially into the adjacent vertebra for secure purchase, as depicted in FIG. 31D . Such plugs may also be positioned bilaterally, that is, with two per level, as shown in FIG. 32 .
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Methods for treating a defect in an annulus fibrous are described. The annulus fibrosis has an outer layer, at least one inner layer, and a defect extending through the outer and inner layers. An implant is inserted into the defect in the annulus fibrosis, the implant having at least one aperture. The implant is advanced distally beyond the outer layer in the annulus fibrosis and positioned to occlude the defect. An elongate fixation element is inserted through the at least one aperture, the elongate fixation element having a first end region and a second end region. The elongate fixation element is positioned such that the first end region is within the at least one aperture. The second end region of the elongate fixation element is anchored to the annulus fibrosis. The implant prevents escape of nucleus pulposus through the defect.
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RELATED APPLICATIONS
The present invention was first described in Disclosure Document No. 453899 filed on Mar. 29, 1999. There are no previously filed, nor currently any co-pending applications, anywhere in the world.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to pollution prevention and, more particularly, to a bulk liquid cargo spill prevention system of the expandable bladder bladder type for a bulk liquid cargo tanker.
2. Description of the Related Art
In the related art, methods and systems for preventing or controlling the spillage of bulk liquid cargoes such as oil into the sea are well known. In fact, there are many tanker ships whereby the loss of liquid bulk cargoes, usually petroleum products, is attempted to be minimized in case of cargo tank rupture through the ship's design. The most recent and well know is the addition of a second hull to a tanker vessel whereby the outer hull protects the inner hull/cargo tank from rupture. There are also tankers designed with the cargo tanks located relative to the waterline in such a fashion that in the event of a tank rupture, the oil leaking out of the tank is minimized by a phenomena known as hydrostatic lock. There are also tankers with various arrangement of cargo tanks, ballast tanks and piping systems for transferring liquid bulk cargo to the ballast tank in the event of cargo tank rupture.
Each of these methods and designs has its limitations. The double hull tanker significantly increases ship construction costs and seriously affects the ship's stability. Other ship designs employing gravity means or pumps to move liquid bulk cargo to an empty ballast tank generally do so at the expense of decreasing ship stability. Another design provides limited impact protection of a cargo tank by surrounding the tank with a single flexible bladder which deflect and yield to the energy of impact. Similarly, yet another design consists of a protective layer placed against the hull segregated from the liquid cargo by a flexible liner. If the hull is punctured, the protective layer will hold the flexible liner in place and hence the liquid cargo will be prevented from leaking from the tank.
There exist in the art other methods and devices that aren't an integral part of the ship's design but can be employed in the event a liquid bulk cargo tank is ruptured. One design contemplates pumping liquid cargo into a collapsible bladder which is placed over the ship's side into the sea and made buoyant. The bladder is normally stowed in a collapsed configuration on deck ready for immediate deployment. Another design contemplates a collapsible bladder normally stowed within a cargo tank that the liquid cargo can be pumped into in the event the tank is ruptured. The bladder is designed to conform to the interior contour of the cargo tank and as the liquid cargo pumped into the bladder causes the bladder to expand the interior volume of the tank is encapsulated. The outer wall of the bladder then forms a seal on the ruptured wall of the tank preventing any further flow of seawater into the tank. There is no further discharge of liquid cargo since all of the liquid cargo in the tank has been pumped into the bladder.
The present invention is of the collapsible bladder type stowed in the cargo tank with a novel collapsible bladder arrangement and control system.
A search of the prior art did not disclose any patents that read directly on the claims of the instant invention; however, the following references were considered related:
______________________________________U.S. Pat. No. Inventor Issue Date______________________________________4,389,959 Conway June 28, 19835,052,319 Beyrouty October 1, 19915,347,943 Fujita, et al. Sep. 20, 19945,353,728 Strange Oct. 11, 19945,271,350 Newburger Dec. 21, 19935,349,914 Lapo, et al. Sep. 27, 19945,735,227 Goulding April 7, 19983,844,239 McLaughlin et al. Oct. 29, 19743,906,880 Hebert Sep. 23, 19755,119,749 Velleca, et al. June 9, 19725,125,353 McGuiness June 30, 1992______________________________________
The above list of patents can be divided into two groups. The first group of patents are considered related to but not directly relevant to the present invention and require no further discussion:
U.S. Pat. No. 4,389,959 issued to Conway discloses an improved tanker vessel of the type where the liquid cargo tanks are arranged in such a fashion that should the hull be breached the liquid cargo is prevented from leaking from the hull through hydrostatic loading;
U.S. Pat. No. 5,052,319 issued to Beyrouty discloses a collapsible bladder which can stored on deck but deployed over the side to pump liquid cargo from a ruptured leaking cargo tank;
U.S. Pat. No. issued to Fujita et al., discloses another tanker design where the hull is of a double layer design where the outer layer is supposed to protect the inner layer, serving also as the outerwall of a liquid cargo tank, from further damage. In addition, the liquid cargo tanks are arranged in such a fashion that should the hull be breached the liquid cargo is prevented from leaking from the hull through hydrostatic loading;
U.S. Pat. No. 5,353,728 issued to Strange discloses an improved tanker design where a passive, gravity-responsive, fluid transfer system provides very rapid fluid communication between selected cargo tanks and adjoining ballast tanks;
U.S. Pat. No. 5,271,350 issued to Newburger discloses an apparatus comprised of a series of bladder modules whose walls are made of a flexible material of sufficient strength to substantially withstand rupture upon such impact. Each flexible module comprises an inboard cargo-carrying bladder surrounded out-boardedly by a buffer bladder containing air under pressure;
U.S. Pat. No. 5,349,914 issued Lapo, et al., discloses a device for impeding the spillage of a liquid cargo which consists of a protective layer placed against the inner surface of the hull and a flexible inner layer placed between the protective layer and the liquid cargo, so that if the hull is punctured, the protective layer will hold the flexible liner and the liquid cargo in place;
U.S. Pat. No. 5,735,227 issued to Goulding discloses an apparatus for sealing a rupture in a wall comprised of a backing plate and a seal. The '227 reference teaches that such an apparatus may be used to seal a ruptured hull of a ship.
The second group of patents from the list above are considered relevant and directly related to the present invention:
U.S. Pat. No. 3,844,239 issued to McLaughlin et al. discloses a liquid carrying tanker with an impermeable, elastomeric tailored lining releasably fixed to the inner walls of the liquid cargo tank, the lining being adapted to separate from the walls of the tank when the tanks are impacted such as when the ship is in a collision or grounded. The distortion of the liner causes the liquid pressure in the liner to increase and force the liquid from the liner into another tank;
U.S. Pat. No. 3,906,880 issued to Hebert discloses a vinyl liner manufactured to fit within and conform to the interior of a liquid cargo carrying tank. Said liner is fixed to the top of the tank and designed to be dropped into the tank and have the liquid cargo from the tank pumped into when the tank is ruptured;
U.S. Pat. No. 5,119,749 issued to Velleca, et al. discloses another system whereby liquid from a ruptured cargo tank is to be pumped into a flexible liner located within the tank for rapid deployment. The expanded liner holding the liquid cargo prevents it from leaking through the hull and at the same time seals the ruptured hull preventing seawater from further entering the hull;
U.S. Pat. No. 5,125,353 issued to McGuiness discloses yet another system whereby liquid from a ruptured cargo tank is to be pumped into a flexible liner. The expanded liner holding the liquid cargo prevents it from leaking through the hull and at the same time seals the ruptured hull preventing seawater from further entering the hull. However, the '353 reference indicates that this system is not fixedly connected to the interior of a cargo tank but is to be dropped through a hatch in the top of the tank when needed.
With the exception of the '353 reference, all of the inventions in the second group are like the present invention in that they all have a flexible, collapsible liner or bladder which is fixedly connected to the interior of a cargo tank for rapid deployment should one of the tank walls be breached. Once the tank wall is breached, a pumping means pumps the liquid cargo into the bladder causing it to expand. The liner or bladder was manufactured to conform to the interior of the tank so that any obstacles in the tank would not impede the expansion of the tank and so that the entire volume of liquid can be pumped into the bladder. The expanded bladder also serves to form a seal against the inner wall of the tank which was ruptured preventing any further spillage of seawater into the tank.
What is different about the present invention from the these inventions is a novel means whereby the collapsible bladder is fixedly connected to an interior sidewall of the tank and deployed suspended hanging from a track via a tram and trolley assembly. Suspending the bladder from the track in this manner not only guarantees the successful deployment of said bladder but also allows the bladder to be retracted and collapsed back correctly when the tank rupture has been fixed. A novel means for sensing when a tank is ruptured and signaling when to deploy the bladder is also disclosed using an advanced fiber optics sensing system. In addition, a pumping means integrated into the design of the ship and the cargo tanks is disclosed with a self-actuating emergency backup system being further provided. None of the aforementioned prior art discloses any type of control system for use with such a emergency bladder system or a means for sensing when to employ said system as in the present invention.
Consequently, a need has been felt for providing an apparatus for containing liquid cargo when a cargo tank is ruptured which can be deployed rapidly, automatically, is retractable and reuseable, and provides an emergency backup means should power from the tanker be unavailable. The present invention fulfills this need.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide an improved emergency expandable bladder for containing and encapsulating the liquid cargo from a ruptured liquid cargo tank.
It is a feature of the present invention to provide a novel control means whereby a ruptured tank is detected automatically and said emergency expandable bladder is deployed It is another feature of the present invention to provide a novel configuration of the emergency expandable bladder whereby said bladder is fixedly connected to an interior sidewall of a liquid cargo tank and deployed slidably suspended from an overhead track.
It is yet another feature of the present invention that the emergency expandable bladder be retractable after successful deployment of said bladder and repair of the breached liquid cargo tank.
It is still yet another feature of the present invention to provide a pumping means to pump the liquid cargo from a breached cargo tank into said emergency expandable bladder.
A further feature of the present invention to provide an emergency backup means to provide power for the control system and to the pumping means should ship's electrical power suddenly become unavailable.
Yet another feature of the present invention is that the placement of the liquid cargo tanks and accompanying segregated ballast tanks are such that should the cargo tanks be breached, the liquid cargo is in hydrostatic equilibrium with the seawater on the exterior of the ship's hull.
Still yet another feature of the present invention is that a segregated ballast tank is provided for receiving liquid cargo from another portion of the cargo tank located beneath a portion of the cargo tank designed to be encapsulated by said bladder. Said segregated ballast tank is provided with a venting means for venting an inert gas previously injected into said tank when receiving liquid cargo from tank as described above.
Yet still another feature of the present invention is a system for providing and supplying an inert gas such as nitrogen to the segregated ballast tanks to reduce the oxygen content in said tank to below explosive levels.
Briefly described according to the preferred embodiment of the present invention, an emergency expandable bladder is provided comprised of a collapsible, accordion-like bladder made from a sturdy, impermeable material manufactured to conform to the individual contour of the interior of a liquid cargo tank. The bladder is attached to the interior side of the inboard sidewall of the liquid cargo tank and expands in an outboard direction as liquid from within the ruptured tank is pumped from the tank into the bladder. To ensure successful expansion of the bladder, the bladder is slidably suspended overhead from a plurality of tracks traversing the top of the tank. Suspending the bladder in this manner also ensures that the bladder can be retracted and returned to the same configuration once the tank rupture is repaired. The liquid cargo tank consists of four sidewalls, one of which is usually the ship's outer hull, a top wall, a bottom wall which is usually the ship's bottom hull, and an oil deck used to define the tank into an upper volume and a lower volume. Said expandable bladder is designed only to encapsulate said upper volume. A plurality of elongated holes in said oil deck allows free communication of liquid cargo from said upper volume to said lower volume.
Located adjacent to said liquid cargo tank and on the inboard side of said tank is a segregated ballast tank for receiving liquid cargo from said lower volume of said liquid cargo tank in the event said liquid cargo tank is ruptured. Prior to filling said liquid cargo tank, an inert gas such as nitrogen or exhaust gas from the ship's flue is used to pressurize said ballast tank and to reduce the oxygen content in said ballast tank to a level where ignition or explosion of the vapors in said ballast tank is not possible. A relief valve connected to and controlled by said emergency expandable bladder control system vents said inert gas to the atmosphere in the event the adjacent liquid cargo tank is ruptured and the expandable bladder deploys. The segregated ballast tank further has a valve located in the bottom of said tank to allow, when in an open position, free communication of liquid cargo through a channel connected to the lower volume of said liquid cargo tank with the interior of said ballast tank. Said valve is kept in the closed position upon filling said ballast tank with inert gas and liquid cargo tank with liquid cargo. Once both tanks are filled, said valve is opened. Inert gas pressure equal to the liquid cargo pressure at the valve pressure head keeps liquid cargo from said liquid cargo tank from coming into the ballast tank until such time as when inert gas is vented to the atmosphere. This pressure would have to be calculated beforehand and would depend on the volume of both tanks and the specific gravity of both the inert gas and the liquid cargo. The channel is formed by the bottom wall of said ballast tank and the bottom hull of the ship. Said free fluid communication is desirable when the liquid cargo tank has been ruptured and after said inert gas has been vented to the atmosphere from said ballast tank. Located within said channels are a series of flapper check valves to allow the flow of liquid cargo in only one direction from the lower volume of the liquid cargo tank to the segregated ballast tank. The flapper valves are placed over an aperture formed through and located on the inboard side of a longitudinal I-Beam section perpendicularly traversing the channel and forming an integral part of the ships supporting structure.
Located on the outer sidewall but on the inner surface of the liquid cargo tank are a plurality of sense cables encased in a tube tack-welded and placed perpendicularly at evenly spaced intervals along a plurality of steel longitudinal sections forming the supporting framework of the outer sidewall of said liquid cargo tank. Another plurality of sense cables enclosed in a conduit are tack-welded on the interior side of the bottom of the liquid cargo tank. One end of the sense cables are attached to the hull structure of the ship while the other end is connected to a switch. The switch is connected to a fiber optic cable for sending a signal to the control system indicating that one of the sense cables has been disturbed by a distortion of the hull the sense cable was located adjacent to.
The control system receiving the signal actuates a relay, which in turn actuates an electric motor, or alternately a diesel engine, both of which are mechanically coupled to drive a hydraulic pump to supply hydraulic pressure to a hydraulic motor located in a sump situated between the liquid cargo tank and the segregated balance tank. The bottom plate of the sump is actually the upper surface of the oil deck with the elongated holes allowing free fluid communication of cargo liquids from the lower volume of the liquid cargo tank through the channel formed by the oil deck and the bottom hull.
Located within the sump is a hydraulic motor having an inlet to receive cargo liquids, an impeller driven by the hydraulic motor to pump cargo liquids through piping which delivers it to the interior of the expandable bladder. Fluid pressure now building up within the bladder forces the bladder to expand and move in an outboard direction suspended overhead by a plurality of rollers and tracks. Once the entire volume of fluid has been pumped from within the liquid cargo tank into the bladder, the bladder should now be fully expanded and the exterior of the bladder surface should now cover over the ruptured hull preventing any further seawater from entering the hull. The liquid cargo may remain in the bladder until such time as the rupture may be repaired in a shipyard. Once the rupture is repaired, the bladder may be retracted into its original stowed configuration by pumping the fluid back out of the bladder by reversing the direction of the hydraulic motor/impeller.
A backup battery is provided to supply power to the control system when ship's power is not available. Upon receiving a signal that a liquid cargo tank has been breached and that no ship's power is available, a relay energizes an electric starter motor to start a backup diesel engine. The backup diesel engine delivers the rotary power formerly delivered by the electric motor to drive the hydraulic pump supplying the hydraulic pressure to the hydraulic motor/impeller to pump fluid from the liquid cargo tank into the emergency expandable bladder.
BRIEF DESCRIPTION OF THE DRAWINGS
The advantages and features of the present invention will become better understood with reference to the following more detailed description and claims taken in conjunction with the accompanying drawings, in which like elements are identified with like symbols, and in which:
FIG. 1 is a cutaway elevated perspective view of the stern of a bulk liquid cargo tanker showing a typical placement of the emergency expandable bladder system in the aft-most port side liquid cargo tank;
FIG. 2 is a cutaway rear view of the port side of the bulk liquid cargo tanker shown in FIG. 1 showing a typical emergency expandable bladder assembly installed in a liquid cargo tank and the segregated ballast tank located adjacent to it;
FIG. 3 is a cutaway rear view of the port side of the bulk liquid cargo tanker show in FIG. 1 showing the installation of the emergency expandable bladder installed slidably hanging from an overhead track in a liquid cargo tank and the placement of the hydraulic motor, impeller, and piping inlet in the adjacent sump;
FIG. 4a is a rear cutaway view of the port side of the liquid bulk cargo tanker shown in FIG. 1 showing the placement of a plurality of fiber optic switch assemblies through an aperture formed in the outer deck plate and the placement of a plurality of sense cable assemblies tack-welded perpendicularly to the longitudinal channels which form the supporting framework of the outer sidewall of a port liquid cargo tank and the port side of the hull of the tanker.
FIG. 4b is a perspective cut away view of the port hull sidewall taken along line IV--IV of FIG. 4a showing the detail of the connection of a sense cable conduit to the hull sidewall elongated longitudinal channels and the attachment of an optional support bracket.
FIG. 5a is a cutaway rear view of the port side of the bulk liquid cargo tanker shown in FIG. 1 showing the detail of the placement of one of the fiber optic switches and the sense cable assemblies and its operation when distorted by an impact to the bottom of the liquid cargo tank/bottom hull from an obstacle such as a reef;
FIG. 5b is cutaway rear view of the port side of the bulk liquid cargo tanker shown in FIG. 1 showing the detail of the placement of one of the fiber optic switches and the sense cable assemblies and its operation when distorted by an impact to the outboard side of the liquid cargo tank/side hull as in a collision with another ship;
FIG. 6 shows a cutaway elevated perspective view of a typical segregated ballast tank of the liquid bulk cargo tanker of FIG. 1 showing the placement of the Inert Gas System valve/vent on its upper plate and a valve with a manually operated handwheel used for pressurizing the tank shown in the open position;
FIG. 7 shows a cutaway elevated perspective view of a hydraulic motor/impeller sump of the liquid bulk cargo tanker of FIG. 1 for use in conjunct with a liquid cargo tank.
FIG. 8 shows a schematic of the electrical control and power system for the emergency expandable bladder system of the of the liquid bulk cargo tanker of FIG. 1;
FIG. 9 shows a schematic of the hydraulic power system and piping for the emergency expandable bladder system of the of the liquid bulk cargo tanker of FIG. 1;
FIG. 10a shows a front cutaway view of one of the fibre optic switch's of the emergency expandable bladder system of the of the liquid bulk cargo tanker of FIG.
FIG. 10b shows a side cutaway view of one of the fibre optic switch's of the emergency expandable bladder system of the of the liquid bulk cargo tanker of FIG. 1;
FIG. 10c shows a side cutaway view of the fibre optic jumper cable inserted in the cradle assembly and the cutter mechanism from the fibre optic switch of FIGS. 10a and 10b;
FIG. 10d shows a cross sectional elongated longitudinal view of a sense cable conduit showing the hollow teflon liner contained coaxially within the conduit and a sense cable located coaxially and slidably within said liner.
______________________________________LIST OF REFERENCE NUMBERS______________________________________100 Tanker110 Hull111 Hull Sidewall111a Inner Surface Hull Sidewall111b Outer Surface Hull Sidewall112 Hull Bottom112a Inner Surface Hull Bottom112b Outer Surface Hull Bottom113 Keel114 Bottom Hull Longitudinal I- Beam115 Aperture116 Hull Sidewall Longitudinal Channel117 Main Deck Plate118 Aperture119 Outer Surface Main Deck Plate120 Inner Surface Main Deck Plate121 Main Deck Longitudinal I-Beam122 Oil Deck Plate123 Lower Surface Oil Deck124 Upper Surface Oil Deck125 Elongated Apertures126 Liquid Cargo Tank127 Liquid Cargo Tank Forward Sidewall128 Liquid Cargo Tank Aft Sidewall129 Liquid Cargo Tank inboard Sidewall130 Liquid Cargo Tank Upper Volume131 Liquid Cargo Tank Lower Volume200 Emergency Expandable Bladder Assembly210 Expandable Bladder211 Exterior Sidewalls212 Interior Sidewalls213 Piping Inlet214 Tracks215 Hangars216 Rollers217 Sump218 Top plate219 Aft Wall220 Forward SideWall221 Hydraulic Motor222 Impeller223 Impeller Housing224 Impeller Housing Inlet Piping and Float225 Discharge Aperture226 Inlet Piping227 Outlet Piping300 Segregated Ballast Tank311 Tank Top Plate312 Inboard Sidewall313 Outboard Sidewall314 Forward Sidewall315 Aft Sidewall320 IGS Relief Valve321 IGS Inlet Piping322 IGS Gas Outlet Piping330 Segregated Ballast Tank Valve Assembly331 Hand Wheel/Actuator332 Transmission Shaft333 Valve Cover334 Ring335 Aperture340 Channel341 Flapper Check Valve342 Aperture400 Expandable Bladder Power & Control System401 Inverter402 Wiring Harness403 Battery Pack404 Wiring Harness405 Wiring Harness406 Wiring Harness407 Ship's Service Three Phase Power Supply408 Two Wire Step Down Transformer409 Wiring Harness410 Diesel Engine Starter Motor Relay411 Wiring Harness412 Diesel Engine Starter Motor413 Diesel Engine414 Diesel Engine Clutch415 Wiring Harness416 Fuel Valve Switch417 Oil Pressure Switch418 Wiring Harness419 Relay420 Electric Motor Contactor421 Shaft/Armature of Electric Motor422 Electric Motor423 Shaft to Hydraulic Pump424 Wiring Harness425 Main Power Bus426 Wiring Harness427 Wiring Harness428 Wiring Harness429 Transformer430 Wiring Harness431 Switches On/Off432 Wiring Harness433 Light Beam Emitter434 Optic Fiber Cable435 Optic Fiber Cable436 Beam Splitter437 Optic Fiber Cable438 Annunciator Panel439 Annunciator Light440 Optic Fiber Cable441 Optic Fiber Cable to Electric Eye442 Electric Eye442 Relay443 Wiring Harness444 Wiring Harness445 Wiring Harness446 Wiring Harness447 Wiring Harness448 Relay DPST449 Wiring Harness450 Wiring Harness451 Horn500 Hydraulic Subsystem501 Valve502 Hydraulic Reservoir503 Hydraulic Pump504 Filter505 Hydraulic Pressure Supply Piping506 Pressure Gauge507 Pressure Regulator508 Check Valve509 Supply Manifold510 Piping511 Piping512 Pressure Relief Valve513 Return Manifold514 Filter515 Hydraulic Supply Piping515a Piping515b Valve515c Piping515d Valve515e Piping516 Hydraulic Return Piping516a Piping516b Valve516c Piping516d Valve516e Piping517 Check Valve518 Piping600 Fiber Optic Switch and Sense Cable Assembly601 Fiber Optic Switch601a Plunger601b Cutter601c Jumper601d Cradle601e Switch Body601f Switch Cover601g Eyelet601h Spring601i Aperture601j Aperture601k Eyelet602 Sense Cable603 Sense Cable Conduit604 Teflon Sleeve605 Support Bracket606 Aperture607 Eyelet608 Support Bracket______________________________________
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The best mode for carrying out the invention is presented in terms of its preferred embodiment, herein depicted within the Figures. 1. Detailed Description of the Figures
Referring now to FIG. 1, shown is an Emergency Expandable Bladder Assembly 200 for the containment of liquid cargo comprised of a liquid tight Expandable Bladder 210 having an interior volume for receiving liquid cargo from a ruptured liquid cargo tank. Said Expandable Bladder 210 is fixedly attached to an Inboard Sidewall 129 of an otherwise conventional Liquid Cargo Tank 126 . A bulk liquid cargo Tanker 100 would typically have a plurality of such Liquid Cargo Tanks 126 located from fore to aft in the cargo hold and port and starboard of the Tanker 100 Keel 113 comingled with conventional ballast tanks in such a configuration as to optimize Tanker 100 stability and buoyancy.
The Bulk Liquid Cargo Tank 126 of FIG. 1 is one from a plurality of such tanks and is typical of such tanks throughout Tanker 100. The Bulk Liquid Cargo Tank 126 shown is the aft-most port side located tank of such tanks. In an alternate embodiment, such tanks may even be stacked one above the other. The placement and arrangement of said Bulk Liquid Cargo Tanks 126 in any embodiment is dependent on a principle known as hydrostatic loading or lock along with stability and buoyancy considerations. Under this principle it is desirable to have the level of fluid in Bulk Liquid Cargo Tank 126 in relation to the waterline along Hull 110 such that if rupture of Bulk Liquid Cargo Tank 126 were to occur the hydrostatic pressure on both sides of the rupture would be nearly equal minimizing leakage of cargo fluid through Hull 110. Only one Liquid Cargo Tank 126 is shown to show the essence of the present invention.
A Bulk Liquid Cargo Tank 126 is comprised of a Forward Sidewall 127, an Aft Sidewall 128, an Inboard Sidewall 129, a Top Plate 117, an Outboard Sidewall 111 also serving as the Tanker 100 Outer Hull 110, a Bottom Wall 112 also serving as the Hull Bottom 112, and an Oil Deck Plate 122 segregating the Liquid Cargo Tank 126 into an Upper Volume 130 and a Lower Volume 131. A plurality of Elongated Apertures 125 allow free communication of liquid cargo in Tank 126 from Lower Volume 131 and Upper Volume 130.
The Expandable Bladder 210 is slidably suspended from a plurality of elongated Tracks 221 slotted along the elongated longitudinal axis of said Tracks 221 to receive a plurality of Rollers 216 made to fit and roll longitudinally within said slot. The Expandable Bladder 210 is connected to Rollers 216 via a plurality of hangars 215. The Expandable Bladder 210 is manufactured to fold accordion-like and stow against the Inboard Sidewall 129 of Tank 126 and to fit exactly inside the Upper Volume 130 of Tank 126 when fully expanded.
In the event of Tank 126 rupture, liquid cargo from Lower Volume 131 would initially be forced into Segregated Ballast Tank 300 by a drop in pressure in said Segregated Ballast Tank 300 created when inert gas pumped into Tank 300 is vented to the atmosphere. Liquid cargo from Upper Volume 130 would naturally flow to Lower Volume 131 via Elongated Apertures 125 in Oil Deck 122. Located directly adjacent to Liquid Cargo Tank 126, and between Segregated Ballast Tank 300, sits a Sump 217 containing a Hydraulic Motor 221. Sump 217 is formed by a Top Plate 218, a Forward Sidewall 220, an Aft Sidewall 219, and the Inboard Sidewall 129 of Liquid Cargo Tank 126 and the Outboard Sidewall 313 of Segregated Ballast Tank 300. Sump 217 is also in fluid communication with Lower Volume 131 via Apertures 125 because its bottom wall is also formed from Oil Deck 122. Liquid cargo flowing up into Sump 217 is drawn into Impeller Housing Inlet Piping and Float 224 when Hydraulic Motor 221 is activated. Fluid drawn into Impeller Housing 223 is discharged into Expandable Bladder 210 through Discharge Aperture 225. The pressure from the liquid cargo being pumped into the Expandable Bladder 210 causes expansion of the Expandable Bladder 210 slidably outboard into Tank 126. Once the cycle is complete all liquid cargo formerly in Upper Volume 131 or Lower Volume 130 will be in either Segregated Ballast tank 300 or Expandable Bladder 210. The exterior surface of Expandable Bladder 210 is now directly adjacent to and butting the outboard sidewall, or actually the Inner Surface Hull Sidewall 111a of the Upper Volume 130 of Tank 126. A rupture in that Sidewall 111a would now be covered over by the exterior of Expandable Bladder 210 sealing that rupture until such time as when Expandable Bladder 210 is emptied. In the event of a bottom rupture, the system operates identically as just described, however, liquid cargo that was formerly in Lower Volume 131 and an adjacent channel 340 is now replaced by seawater which would remain there until the rupture is repaired.
The entire sequence is activated by a Fiber Optic Control and Sense Cable Assembly 600 system connected to Sense Cables 602 located along the walls of the vulnerable portions of the Liquid Cargo Tank sidewalls/outer hull 110 sections. A distortion in these sections such as when there is a collision or grounding will cause the sense cable to rupture a light signal flowing through a Fiber Optic Switch 601 causing the Emergency Expandable Bladder Assembly 200 to become operational.
Referring now to FIG. 2, shown is an Emergency Expandable Bladder Assembly 200 for the containment of liquid cargo comprised of an Expandable Bladder 210 fixedly attached to the Inboard Sidewall 129 of Liquid Cargo Tank 126. More detail of the manner in which Expandable Bladder 210 is slidably attached via a plurality of Hangars 215 and Rollers 216 to Tracks 221 is shown. Also shown in more detail is the segregation of Cargo Tank 126 into an Upper Volume 130 and a Lower Volume 131 by Oil Deck 122. Free fluid communication of liquid cargo from Upper Volume 130 and Lower Volume 131 is accomplished through Apertures 125 in Oil Deck 122. Free fluid communication of liquid is also accomplished to the adjacent Segregated Ballast Tank 300 through a Channel 340 formed by a plurality of Apertures 342 formed in a plurality of Longitudinal I-Beams 114 forming the support structure for the Hull Bottom 112 and bottom sidewall of Liquid Cargo Tank 126.
The detail of Segregated Ballast Tank 300 is shown provided with a Valve Assembly 330 comprised of a Hand Wheel/Actuator 331, Transmission Shaft 332, Valve Cover 333, Aperture 335, and Ring 334. The Valve Assembly 330 is normally kept in an open position but is closed when the Segregated Ballast Tank 300 is filled with an inert gas such as nitrogen and Liquid Cargo Tank 126 is filled with liquid cargo. Once Liquid Cargo Tank 126 is filled, Valve Assembly 330 is opened allowing free fluid communication of fluid from Lower Volume 131 of Liquid Cargo Tank 126 through Channel 340 to Segregated Ballast Tank 300.
In the event of a Liquid Cargo Tank 126 rupture, IGS Relief Valve 320 is signaled to open via current from Electric Eye 442 via Wiring Harness 444 and IGS gas is vented to the atmosphere. IGS Relief Valve 320 remains in the open position until IGS gas in Segregated Ballast Tank 300 is at a designated pressure. The immediate evacuation of IGS gas results in a dramatic drop in pressure in Segregated Ballast Tank 300 drawing liquid cargo from the Lower Volume 131 of Liquid Cargo Tank 126 into Segregated Ballast Tank 300 where it remains until such time that the oil/water mixture is pumped out. The remainder of the liquid cargo is pumped into Expandable Bladder 210 as described heretofore. In an alternate embodiment (not shown), it is envisioned that a system of interconnecting piping and pumps will pump liquid cargo from Segregated Ballast Tank 300 into Expandable Bladder 210 after being separated from seawater that mixed with the liquid cargo upon rupture. Separation of seawater from liquid cargo normally requires a water/oil separator. This whole process requires that Valve Assembly 300 also be closed once Ballast tank 300 is filled with a mixture of liquid cargo and seawater. The separated seawater is then pumped overboard. This system has a two fold purpose. The first is to recover liquid cargo from said Segregated Ballast Tank 300. The other is to transfer liquid cargo back into the ruptured cargo tank 126 to regain lost stability and buoyancy caused by the shifting liquid cargo.
Referring now to FIG. 3, shown is more detail of Channel 340 connecting the Lower Volume 131 of Liquid Cargo Tank 126 made from a plurality of Apertures 342 in a plurality of Longitudinal I-Beams 114 forming the support structure of Hull Bottom 112 and the bottom sidewall of Liquid Cargo Tank 126 bottom hull allowing free fluid communication between Lower Volume 131 and Segregated Ballast Tank 300. A plurality of Flapper Check Valves 341 placed over said Apertures 342 prevents backflow of both liquid cargo and IGS gas to Lower Volume 131. Also shown is the Hydraulic Motor 221/lmpeller 222 within Sump 217. Discharge Aperture 225 formed on the outboard side of Impeller Housing 223 allows free fluid communication of Impeller 222 with the interior of Expandable Bladder 210. A plurality of Fiber Optic Switch and Sense Cable Assemblies 600 are also provided at evenly spaced intervals along the vulnerable sections of outboard sidewall/Hull Sidewall 111 of Liquid Cargo Tank 126 and bottom sidewall/Hull Bottom 112.
Referring now to FIG. 4, a cutaway rear perspective view of a portion of the port side hull structure of a Bulk Liquid cargo Tanker 100 is shown showing the Main Deck Plate 117 connected to a portion of the Hull 110. A bulk liquid cargo tank rupture sensing means lining the outboard sidewall and the bottom wall of a typical Bulk Liquid Cargo Tank 126 is shown. Said means consists of a plurality of evenly spaced Fibre Optic Switches 601 fitted in an Aperture 118 penetrating the Main Deck Plate 117 adjacent to the outboard edge of Main Deck Plate 117. Each of said Fiber Optic Switch 601 is ganged to each other in series through fiber optic cabling and designed to interrupt a beam of light flowing through said Fiber Optic Switches 601 upon indicia to any one of said Fiber Optic Switches 601 that a bulk liquid cargo tank has been ruptured. Connected to each of said Fibre Optic Switches 601 on the Inner Surface 120 side of Main Deck Plate 117 is a Conduit 603 containing coaxially therein a hollow Teflon Sleeve 604 which has located coaxially and slidably therein one of said Sense Cables 602. Said Sense Cables 602 line at evenly spaced intervals the inner surfaces of said tank side walls that also serve as a portion of the ship's hull and designed to transmit an indicia of a distortion in said tank walls. Conduit 603 is attached via a tack weld to each of the Elongated Longitudinal Channels 116 perpendicular to the elongated longitudinal axis of said Channels 116. A Support Bracket 608 extending from the Inner Surface 111a of the Hull Sidewall 111 to Conduit 603 may be added for strength between adjoining Longitudinal Channel Sections 116.
Referring now to FIG. 5a, shown is a cutaway rear view of a cross section of the lowermost portion of the port Hull Sidewall 111 showing a single placement of the Fibre Optic Switch and Sense Cable Assembly 600. A distortion of the Sense Cable 602 along the Hull Bottom 112 and bottom sidewall of Liquid Cargo Tank 126 is demonstrated by an impact to the Hull Bottom 112.
Referring now to FIG. 5b, shown is a cutaway rear view of a cross section of the lowermost portion of the port Hull Sidewall 111 showing a single placement of the Fibre Optic Switch and Sense Cable Assembly 600. A distortion of Sense Cable 602 along the port side of the Hull Sidewall 111 and outboard sidewall of Liquid Cargo Tank 126 is demonstrated by an impact to Hull Sidewall 111.
Referring now to FIG. 6, shown is a perspective view of a typical Segregated Ballast Tank 300 with Valve 330 in the open position. A Hand Actuator 331 is used by the crew to force Valve Cover 333 against Ring 334 via Transmission Shaft 332 to seal Tank 300 when pressurizing with IGS gas through IGS Inlet Piping 321. After Segregated Ballast Tank 300 is pressurized with IGS gas and adjacent Liquid Cargo Tank 126 is filed with cargo liquid, Valve 330 is manually opened allowing free fluid communication of IGS gas with Channel 340. Electrical current from Electric Eye 442 via Wiring Harness 444 connected to IGS Relief Valve 320 triggers said Valve 320 to open and vent IGS gas to the atmosphere through IGS Gas Outlet Piping 322 when the adjacent Liquid Cargo Tank 126 has been ruptured. Once IGS gas has been vented, the resulting drop in pressure draws in fluids through Aperture 335 from Channel 340 and adjoining Lower Volume 131 from Liquid Cargo Tank 126.
Referring now to FIG. 7, shown is a cutaway perspective view of Sump 217 showing the placement of Hydraulic Motor 221/lmpeller 222 inside Sump 217. Also shown is a plurality of Elongated Apertures 125 formed in Oil Deck Plate 122 which serves as the bottom wall of Sump 217. The Apertures 125 allow free fluid communication of liquid cargo from the Lower Volume 131 of Liquid Cargo Tank 126 into Sump 217 where Impeller Housing Inlet Piping and Float 224 connected to Hydraulic Motor 122/lmpeller 222 receives liquid cargo to be pumped into Expandable Bladder 210. Impeller Housing Inlet Piping and Float 224 is made of floatable material so that the inlet end will float at the surface of the liquid cargo in Sump 117 as the liquid level rises and falls. The other end rotates about the Impeller Housing 223.
Referring now to FIG. 8, shown is a schematic of the Emergency Expandable Bladder Power and Control System 400. Three-phase alternating current from Tanker 100 Ship's Service Power 407 supplies an Electric Motor 422 which provides rotary power via a Shaft 423 to Hydraulic Pump 503 used to drive Hydraulic Motor 122/Impeller 222. Electric Motor 422 is energized via an Electric Motor Contactor 422 upon signal from Electric Eye 422 via wiring harness 444. Electric Eye 442 deploys the Emergency Bulk Oil Recovery System by signaling said Electric Motor Contactor 420 when said light source has been interrupted and no longer present at Fibre Optic Cable 441. Fiber Optic Cable 441 normally receives said a light source from Beam Splitter 436. Beam splitter 436 inputs said light source from Fibre Optic Cable 435 returning from said tank rupture sensing means and breaks said light source into two separate beams for providing a first output and a second output. The first output is connected to Fibre Optic Cable 441 and the second output is connected to Annunciator Panel 438 via Fibre Optic Cable 437 for lighting Annunciator Light 439 located within said Annunciator Panel 438. Annunciator Panel 438 is located in the pilot house of Tanker 100 for alerting the crew by the extinguishment of Annunciator Light 439 (normally lighted) and the sounding of Horn 451 that the Emergency Bulk Liquid Cargo Spil Prevention System 210 is deploying. Fibre Optic Cable 435 receives light source from one end of Fibre Optic Jumper 601c inserted through Fibre Optic Switch 601 and ganged in series to a plurality of Fiber Optic Switches 601. Any one of the Fibre Optic Switches 601 can interrupt the light source indicating a rupture in Liquid Cargo Tank 126. The other end of the Fibre Optic Jumper Cable 601c normally receives light source from one end of Fibre Optic Cable 434. The other end of Fibre Optic Cable 434 is connected to Light Beam Emitter 433, which is the light beam source. Light Beam Emitter 433 is connected to Switch 431 via Wiring Harness 432. Switch 431 is connected to Step Down Transformer 429 via Wiring Harness 430. Switch 431 is normally closed but can be opened to cut power to Light Beam Emitter 433 to manually deploy Expandable Bladder 210. Step Down Transformer 429 receives higher voltage from said main power bus and supplies reduced voltage to Light Beam Emitter 433. Main Power Bus 425 distributes power to the various electrical components of said system and is configured so that a control circuit for an Emergency Bulk Liquid Cargo Spill Prevention System for each Liquid Cargo Tank 126 may be added in parallel. The Main Power Bus 425 receives single phase a/c power from a Two-Wire Step-Down Transformer 408 which has been converted from conventional ship's service three AC power 407. Power from Main Power Bus 425 is also supplied to Electric Eye 442 via Wiring Harness 445 and, when appropriate, to Relay 419 via Wiring Harness 444 to energize Electric Motor Contactor 420. Power from Main Power Bus 425 also keeps Relay 448 energized keeping a Backup Power Bus 404 electrically isolated from Light Beam Emitter 425 and Electric Eye 442.
Should Tanker 100 lose Three-phase Electrical Power 407, power in Main Power Bus 425 would also be lost and Relay 448 would no longer be energized. As a result, Main Power Bus 425 is electrically isolated from Light Beam Emitter Transformer 429 and Electric Eye 442. Power from a Backup Battery 403 is converted to ac power by Inverter 401 connected via Wiring Harness 402 to supply Backup Bus 404 with electrical power. When Relay 448 lost power from the Main Power Bus 425, the contacts then switch so that Light Beam Emitter Transformer 429 and Electric Eye 442 are no longer electrically isolated from Backup Power Bus 404 and now draw power from Backup Power Bus 404. At the same time, de-energized Relay 448 sends electrical current to Wiring Harness 406 which energizes Starter Motor Relay 410 sending current to Diesel Engine Starter Motor 412 to start Backup Diesel Engine 413. An Oil Pressure Switch 417 interrupts current to Diesel Engine Starter Motor 412 when Backup Diesel Engine 413 has started and developed sufficient oil pressure. Backup Diesel Engine 413 provides the rotary power formally supplied by the Electric Motor 422 via Shaft 421 connected to Shaft 423 via Clutch 414 activated by current from Backup Power Bus 404 delivered via Wiring Harness 409, 406, 449, Relay 448, and Wiring Harness 450 to deliver rotary power to Hydraulic Pump 503. Backup Diesel Engine 413 is provided with a Fuel Valve Switch 416 which must be supplied current from Wiring Harness 406 before Backup Diesel Engine 413 will start.
Diodes are placed in all wiring harnesses where electrical connections are required to the control circuits from both Main Power Bus 425 and Backup Power Bus 405 to prevent backflow of current from the active power source when the inactive power source is electrically isolated from the control circuit. Diodes 426 are placed in Wiring Harness 427, Diodes 426b in Wiring Harness 428, Diodes 426c in Wiring Harness 444 and Diodes 426d in Wiring Harness 449. Additional control units may be added to Backup Power Bus 404 according to the number of Liquid Cargo Tanks 126 Tanker 100 is configured with.
Referring now to FIG. 9, Hydraulic Power Subsystem 500 is shown for the Emergency Expandable Bladder Assembly 200. Rotary power from either Electric Motor 422 or Diesel Engine 413 drives Hydraulic Pump 503 via Shaft 423 creating hydraulic pressure in conventional hydraulic fluid in Hydraulic Supply Piping 505. Hydraulic fluid is filtered by a Filter 504 and regulated by a Regulator 507. Excess pressure is vented by Regulator 507 by returning fluid to a Return Manifold 513 via Piping 511. In the case of extreme excess pressure, a Safety Relief Valve 512 is provided. A supply of hydraulic fluid feeding Hydraulic Pressure Supply Piping 505 and a place for storing returning hydraulic fluid from Return Manifold 517 is found at Reservoir 502. Controlling when pressurized hydraulic fluid is to be supplied to Hydraulic Supply Piping 515 is electrically operated Valve 501 which opens upon a signal from the Electric Eye 442 via Wiring Harness 444. Similarly, such a valve could be added to Manifold 509 for each Liquid Cargo Tank 126 installed in Tanker 100. Hydraulic fluid pressure is now being supplied to a Hydraulic Motor 221 to drive an Impeller 222 to pump liquid cargo from the Liquid Cargo Tank 126 into the Expandable Bladder 210. A plurality of Valves 515b, 515d, 516b, 516e, shown in FIG. 9 in their normal positions, is used in conjunction with a plurality of interconnecting crossflow Piping Sections 515a, 515c, 515e, 516a, 516c, 516e to reverse the flow of hydraulic fluid being supplied to Hydraulic Motor 422. In the reverse flow configuration, said Valves 515b, 515d, 516b, and 516e are manually placed in their opposite to normal positions and Piping Sections 515a, 515c, 515e, 516a, 516c, and 516e connect Supply Piping 515 to Hydraulic Motor Discharge Piping 227 and conversely, connect Hydraulic Return Piping 516 to Hydraulic Motor Supply Piping 226. This is desirable when the when the rupture in Hull 110 is repaired and it is desired to pump the liquid cargo from the Expandable Bladder 210 back into Liquid Cargo Tank 126. The reversed flow of hydraulic fluid reverses the rotary action of Impeller 222 drawing liquid cargo fluids from within Expandable Bladder 210 and pumping it back into Sump 217 through Impeller Housing Inlet Piping and Float 224. Of course Valve 330 must be put back into the closed position before this is accomplished. A limit switch can be installed to sense when the Expandable Bladder 210 is fully deployed to stop Hydraulic Motor 122. Conversely, another limit switch can be installed to sense when Expandable Bladder 210 has been completely emptied to stop Hydraulic Motor 122.
Referring now to FIG. 10, a front view of a Fiber Optic Switch 601 is shown comprising a Fiber Optic Jumper 601c, a Switch Body 601e forming the structure for said Fiber Optic Switch 601, a Cradle 601d having a pair of dual arms with a cavity therebetween and permanently affixed to said Switch Body 601e, a Plunger 601a, a Spring 601h, a Cutter 601b, and a Switch Cover 601f. The Fiber Optic Jumper 601c is made from a piece of fiber optic cable and is designed to traverse through Apertures 601i specially formed through both Cutter 601b and said dual arms of Cradle 601d. Cutter 601b is slidably sandwiched between the dual arms of Cradle 601d with Fiber Optic Jumper 601c passing through Aperture 601i of Cradle 601d and an Aperture 601j formed in Cutter 601b. The lower end of Cutter 601b is connected to one end of a Plunger 601a having an Eyelet 601k at one end for connection to a Sense Cable 602. Said Plunger 601a is designed to traverse vertically within an interior cavity of said Switch Body 601e specially formed to receive said Plunger 601a and connected to a Cutter 601b at one end and an eyelet 601k at the other end. Upon assembly, Sense Cable 602 is tensioned in its operating position and attached to Eyelet 601k. A Hull 110 distortion will cause either a breakage of said Sense Cable 602 causing said Plunger 601 biased by said Spring 601h to force Cutter 601b in an upward fashion and cutting the Fiber Optic Jumper 601c or causing a tensioning of said Sense Cable 602 and pulling said Plunger 601 in a downward direction again causing said Cutter 601b to cut said Fiber Optic Jumper 601c and in either case cause an interruption of a light source propagating through said Jumper 601c. Now Cutter 601b blocks the light source normally propagating through said Jumper 601c sending a signal to the Electric Eye 442 to start the Emergency Expandable Bladder System 200 operating.
Referring now to FIG. 11, a side view of Cradle 601d is shown showing the installation of Fiber Optic Jumper 601c through the dual arms of Cradle 601d and Cutter 601b slidably sandwiched therebetween.
The foregoing description is included to illustrate the operation of the preferred embodiment and is not meant to limit the scope of the invention. The scope of the invention is to be limited only by the following claims.
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Large bulk liquid cargo tankers are a common sight on the world's oceans and waterways. Petroleum needs worldwide have risen sharply and in order to fulfill those needs cheaply and efficiently, shipbuilders have increased the size of tankers carrying the crude oil to the point where the modern supertanker is capable of carrying millions of barrels of oil in a single trip. Such efficiency has not come without a price in that a single tank rupture can be an ecological and financial disaster. In order to minimize and even the eliminate such a disastrous event, an apparatus has been designed to be deployed inside a bulk liquid cargo tank. Should a tank be ruptured, a large expandable bladder pre-positioned within the tank would expand as oil from within the tank would pe pumped into its internal volume. The expandable bladder serves a dual purpose to act as a seal against the portion of the tank that has been ruptured eliminating the flow of oil out of the tank and seawater into the tank. The present invention is such an expandable recovery bladder with a novel bladder arrangement and a novel fiber optic sensing and control system.
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FIELD OF THE INVENTION
The present invention relates, in general, to an optical transmitter that modulates an optical signal based on a digital data stream. A heater is used to apply heat to an optical modulator in the transmitter.
BACKGROUND OF THE INVENTION
Previously implemented Silicon Photonic optical transmitters include an optical ring resonator modulator that modulates an incoming optical signal. The index of refraction within the ring changes with operating temperature which undesirably shifts the resonance. The index of refraction may also vary as a function of fabrication tolerances (e.g. dimensions of the ring). Some previous systems have implemented an integrated micro-heater that is controlled based on temperature readings from an integrated temperature sensor. In general, the micro-heater applies heat to the ring in an attempt to compensate for undesirable changes in the index of refraction based on the sensed temperature. However, these systems are limited due to the changing characteristics of the temperature sensor due to aging and other effects that degrade the bit error rate (BER) but do not affect the temperature.
SUMMARY OF THE INVENTION
The present invention relates to an optical transmitter that includes an optical modulator configured to modulate an optical signal with a digital data stream, and a heater configured to apply heat to the optical modulator. The optical transmitter also includes an optical receiver configured to receive the modulated optical signal and to convert the modulated optical signal into a received digital data stream. A circuit is configured to compute bit errors in the received digital data stream by comparing the received digital data stream with the digital data stream, and control the heater based on the computed bit errors.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a block diagram of an optical transmitter and an optical receiver, according to an embodiment of the present invention.
FIG. 2A is schematic plan view of an optical ring modulator, according to an embodiment of the present invention.
FIG. 2B is a schematic cross-section view of the optical ring modulator shown in FIG. 2A along section line 2 - 2 , according to an embodiment of the present invention.
FIG. 3A is a plot of the optical ring modulator frequency response for the thru port, according to an embodiment of the present invention.
FIG. 3B is a plot of the optical ring modulator frequency response for the drop port, according to an embodiment of the present invention.
FIG. 4 is a plot of the logic 0 and logic 1 bit error rate (BER) computed by the optical transmitter, according to an embodiment of the present invention.
DETAILED DESCRIPTION
As will be described, the present invention provides a system and method for actively controlling the resonance wavelength of a resonant optical device. In one example, an optical transmitter may include a resonant optical device such as an optical ring resonator having multiple light ports (e.g. a thru port and a drop port). A continuous wave (CW) light signal such as a laser beam may be input to the optical ring resonator where it is digitally modulated when voltage applied to the ring.
In one embodiment, the optical transmitter includes an optical receiver for converting the modulated optical signal into an electrical signal. The optical transmitter includes circuitry that may include dedicated analog/digital circuits and/or a processor that performs error detection and outputs a control signal to a heater for heating the optical modulator based on the detected errors.
Shown in FIG. 1 is a block diagram of an optical transmitter 100 that is transmitting an optical signal (e.g. a modulated laser beam) over optical link 116 to receiver 150 . It should be noted that receiver 150 may be on the same chip or may be off chip from optical transmitter 100 .
In this embodiment, optical transmitter 100 may include an optical signal (e.g. a laser beam) that is generated by a laser device (not shown) and provides the optical signal to optical modulator 101 where it is modulated (e.g. digitally to transmit logic 1's and 0's). In one example, optical modulator 101 may be an optical ring resonator that includes a thru port 103 , drop port 104 and a heater 34 (not shown).
Optical transmitter 100 also includes optical receiver 110 , digital logic decision circuit 111 , delay circuit 112 , error detector 113 , error lines 114 and 115 , transmission data line 108 , amplifier 107 , controller 109 , modulation control line 105 , and heater control line 106 .
During operation, laser beam 102 is optically modulated (e.g. digitally) by optical modulator 101 . In general, digital data 108 is amplified (at amplifier 107 ) and then a voltage is applied (via control line 105 ) to optical ring modulator 101 . By applying a voltage to the optical ring modulator, the light intensities through ports 103 and 104 may be controlled (e.g. complementary to each other). Thus, as the laser light intensity passing through port 103 is increased, the laser light intensity passing through port 104 is decreased (and vice versa).
The modulation may be a result of the index of refraction of the modulator changing as a function of the changing carrier concentration in the device (i.e. the applied voltage to the modulator changes the index of refraction). It is noted that controlling the temperature of the modulator based on bit errors is not limited to a specific modulation method (i.e. the bit error based control method is applicable to a variety of modulation methods that may be used in conjunction with a variety of resonant modulators).
In general, the modulated laser beam being transmitted over thru port 103 is transmitted over optical link 116 and received at receiver 150 . The modulated optical signal is then demodulated by optical receiver 117 and a decision is made on whether it is a transmitted logic 1 or a logic 0 at detector 118 . The digital bits are then output over line 119 to another circuit (not shown). It is also contemplated that detector 118 may include error correction to correct transmission errors.
As described above, the operating temperature of the optical micro-ring modulator shifts the resonant wavelength. In operation, in order to compensate for this shift, optical transmitter 100 detects transmission errors in the modulated optical signal over drop port 104 and then applies appropriate control voltage to the heater (i.e., to either heat up or cool down modulator 101 ).
For example, modulated signal in drop port 104 is converted by receiver 110 into an electrical signal. Circuit 111 then determines if the transmitted signal is logic 1 or a logic 0. Error detection circuit 113 then compares the received digital data stream with a delay compensated version of the original transmission data 108 , to determine if the transmitted bits and received bits are the same. Error detection circuit 113 is then able to determine if a logic 0 error or a logic 1 error has occurred during optical transmission. The logic 1 errors are transmitted to controller 109 via line 114 whereas the logic 0 errors are transmitted over line 115 to controller 109 . Controller 109 then applies a voltage (over control line 106 ) to the optical modulator heater (not shown).
Logic 1 errors absent logic 0 errors typically mean that the operating temperature is too cold, whereas a mix of logic 1 and logic 0 errors typically means that the operating temperature is too hot (see FIG. 4 ). In one example, for every logic 0 error, a negative electrical pulse may be generated and applied to a proportional integral derivative (PID) controller (not shown) included in controller 109 . For every logic 1 error, a positive electrical pulse may be generated and applied to the PID controller. In response to receiving the negative pulses and positive pulses, the PID controller either decreases or increases a voltage applied to the resistive heater (i.e. decreases or increases the heat applied to the ring).
Thus, in this example, when a logic 0 error occurs, the PID controller (in response to receiving a negative pulse) decreases the voltage applied to the heater to decrease the temperature of optical resonator 101 (i.e. cool it down). In contrast, when a logic 1 error occurs, the PID controller (in response to receiving a positive pulse) increases the voltage applied to the heater to increase the temperature of optical resonator 101 (i.e. heat it up).
In one example, the amplitude of the negative electrical pulses is set to be larger than the amplitude of the positive electrical pulses in order to counteract a scenario where both logic 1 and logic 0 errors occur at similar rates. This example will be further described with respect to FIG. 4 .
FIG. 2A shows the details of an example optical modulator 101 . Specifically, an optical waveguide ring 14 is supported on a substrate 12 with a pair of optical waveguides 16 evanescently coupled to optical waveguide ring 14 in a location near minimum width 18 . In this embodiment, the optical waveguide ring 14 has a width that is adiabatically increasing to a maximum width 20 .
An electrical heater 34 is also located in optical waveguide ring 14 proximate to the location of maximum width 20 . In one embodiment, electrical heater 34 may comprise an impurity doped region when the optical waveguide ring 14 is formed from monocrystalline silicon. The impurity doped region may be a region in the monocrystalline silicon which has been doped with specific doping concentration (e.g. with an impurity such as boron, phosphorus or arsenic). This would make the impurity doped region electrically resistive. When a voltage is applied over opposite ends of electrical heater 34 , the impurity doped region begins to heat ring 14 . In general this changes the index of refraction (i.e. the wavelength) via a thermo-optic effect so that the effective optical path for light 100 ′ circulating around optical waveguide ring 14 is increased (see i.e. this changes the resonant frequency of light 100 ′ in ring 14 ).
In general, electrical power may be supplied to heater 34 through a pair of connecting members 22 which act as electrical contacts. Wiring 40 , which connects to contracts 22 may be connected to heater control line 106 that is connected to controller 109 shown in FIG. 1 (e.g. controller 109 applies the electrical current to the heater through control line 106 ).
Thus, laser beam 102 enters waveguide 16 at port 24 and travels to thru port 103 . The laser beam 102 is also optically coupled through the ring modulator to output through drop port 104 (i.e. the ring optically couples to waveguides 16 when a modulating voltage is applied).
For example, if a modulating voltage is not applied to ring 14 , then laser beam 100 will pass directly through waveguide 16 and exit port 103 (i.e., logic 1 will be transmitted over the thru port). If a voltage is applied to ring modulator 14 , the intensity of the laser beam will be redirected through the ring and into waveguide 16 and exit through drop port 104 (i.e., the logic 1 signal will be output through the drop port). Thus, in this embodiment, the through port and the drop port 26 have a complementary relationship.
As shown in FIG. 2B , optical ring 14 and waveguide 16 may be supported above substrate 12 on layer 36 . Layer 36 may include the various elements 14 , 16 , 22 , and 34 which are formed on a monocrystalline silicon layer of the substrate. Second layer 38 may be deposited over optical ring 14 and optical waveguide 16 . This may be useful for encapsulating elements 14 , 16 , 22 and 34 and to provide support for wiring 40 .
As described in FIG. 2A , when voltage is applied to optical ring 14 , laser beam 102 passing through waveguide 16 is either modulated to pass over thru port 103 or drop port 104 (i.e., the intensity of the light is amplitude modulated based on the voltage applied to the ring). This amplitude modulation is shown in FIG. 3A for the thru port 103 .
It is noted that although an optical ring is described above as the modulator in this example, that the micro-heater may also be incorporated into other micro-resonant devices of different configurations (e.g. a micro-disk modulator). Controlling the temperature of these other micro-resonant devices based on bit errors would be similar to the ring modulator.
Curve 302 (A) and curve 304 (A) are the optical frequency responses of the modulator passing through the thru port 103 when 3.5 volts (e.g. a logic 1) and 0 volts (e.g. a logic 0) respectively are applied to the modulator. Curves 302 (A) and 304 (A) may be shifted in frequency from their desired characteristics due to operating temperature and/or fabrication errors in the optical modulator. In this example, with the input laser wavelength at the frequency shift threshold of 0 GHz, a logic 1 and a logic 0 transmission have similar amplitudes 312 and 310 that may be difficult to distinguish at the receiver (i.e. the amplitudes between the different modulated signals are too close to one another).
In order to correct this undesired frequency shift of the modulator characteristics, in one embodiment, the heater applies heat to shift the frequency response of the modulator closer to its desired frequency (i.e. a frequency shift of 0 GHz). The shifted frequency response is shown by curves 302 (B) and 304 (B) when 3.5 volts (e.g. a logic 1) and 0 volts (e.g. a logic 0) are applied respectively to the modulator. When the modulator is operating at the proper temperature, the points where the two curves cross the 0 GHz frequency shift threshold 306 and 308 are sufficiently different from one another (i.e., it is easier to distinguish between the intensity of a logic 1 and a logic 0).
A similar scenario is shown in FIG. 3B for the drop port. Curves 314 (A) and 316 (A) (where 3.5 volts and 0 volts are applied to the modulator respectively), cross the frequency shift threshold of 0 GHz at points 322 and 324 which are hard to distinguish from each other (e.g. logic 0 and logic 1 transmissions have similar light intensities). As described above, this is due to shifts in the resonant wavelength of the modulator caused by operating temperature and/or fabrication tolerances of the modulator. In the example system, once the heater applies the appropriate amount of heat to the modulator based on the bit error rate, the curves shift to become curves 314 (B) and 316 (B) which cross the threshold at points 320 and 318 respectively (e.g. logic 0 and logic 1 transmissions have distinguishable light intensities).
In one example, the behavior of logic 0 errors and logic 1 errors are shown in FIG. 4 with respect to the operating temperature of optical modulator 101 . At temperature shifts less than 0° C., the bit errors are primarily logic 1 errors as shown by graph 402 . However, in this example, between temperature shifts of 0° C. and approximately 4° C., there is a mixture of logic 0 errors and logic 1 errors as shown by the overlapping of curves 402 and 404 . Temperature shifts greater than 4° C. show that the errors are once again primarily logic 1 errors. Thus, in region 406 , the errors are all logic 1 errors, in region 408 , the logic errors are a mixture of logic 1 and 0 errors, and in region 410 the errors are all logic 1 errors.
Thus, when controller 109 receives all logic 1 errors (assuming the modulator is operating in region 406 ) a positive amplitude electrical pulse is applied to the PID controller which increases the voltage applied to the heater thereby increasing the temperature of the modulator in an attempt to shift the operating temperature closer to its target value (i.e. obtain a temperature shift close to 0° C.) in order to reduce the errors.
If, however, the system is operating in region 408 (i.e., there is a mixture of logic 0 and logic 1 errors), both positive and negative electrical pulses are applied to the PID controller in response to receiving both logic 1 and logic 0 errors. Since there is a mixture of both logic 1 and logic 0 errors, the negative electric pulse that decreases the temperature of the modulator may have a higher amplitude than the positive electrical pulses, otherwise the system may get stuck in region 408 . For example, if both positive and negative pulses have the same unit amplitude, then for every logic 1 error, the temperature would increase and for every logic 0 error, the temperature would decrease, and therefore the temperature would get stuck in a region where the rate of logic 0 and logic 1 errors are similar.
By increasing the amplitude of the negative electrical pulse to be higher than the positive electrical pulse (e.g., positive electrical pulse may be 1 unit amplitude, whereas the negative electrical pulse may be 3 unit amplitudes), the PID controller will decrease the voltage applied to the heater for a logic 0 error more significantly than it will increase the voltage applied to the heater for a logic 1 error. Therefore, the system will not get stuck in region 408 where the logic 0 and logic 1 errors are equivalent.
It should also be noted that in FIG. 4 , if all logic 1 errors are detected, the modulator may be operating in either region 406 or 410 . A distinction between these two regions may be made in order to determine whether a negative or a positive electrical pulse should be applied to the heater. This distinction may be made based on the temperature of the modulator (i.e., a temperature-sensing device may be integrated into modulator 101 ) or by knowing that when the device initially starts up, the temperature is colder than it should be, and is initially operating in region 406 .
In one example, receiver 110 may have higher noise characteristics than receiver 117 in order to generate errors that are used in the correction algorithm. This can be accomplished by designing a receiver with lower transimpedance than would otherwise be required. Other ways to produce more errors may include measuring error rates at multiple signal to noise ratio thresholds.
Optical receiver 117 may be off chip or on chip. Receiver 117 in general, may have a lower noise floor and perform essentially error-free when a modulator wavelength is optimized using the bit error rate corrections as described above. In other embodiments, both may be routed from the same port with a splitter routing part of the signal to each receiver. In another embodiment, bit error correction may be utilized at receiver 117 .
In another embodiment, optical modulator 101 may include a cooling device such as a fan (not shown) or a thermoelectric cooler (not shown) that is also controlled by controller 109 to cool down the ring modulator more rapidly. The cooling device may be external to the modulator or may be micro-cooler that is integrated into the modulator structure similar to the heater.
In one example, when controller 109 wants to lower the temperature, the amplitude of the electrical signal applied to the heater may be reduced while the amplitude of the electrical signal applied to the cooler may be increased, therefore cooling down the modulator more rapidly. It should also be noted that a heat sink (not shown) may be coupled to the ring modulator through a thermal resistance (not shown) as a passive cooling device which radiates the heat away from the ring modulator more rapidly.
It should be noted that the electrical devices (e.g. 111 , 112 , 113 , 107 and 109 ) within optical transmitter 100 may be implemented as dedicated hardware circuits (e.g. analog and/or digital circuits) that may include a field programmable gate array (FPGA) and/or a processor for implementing the method in software.
It should also be noted that other types of optical modulators having different geometries and different numbers of ports may also be controlled utilizing the error rate control algorithm described above. These include, without limitation, an electro-absorption modulator (EAM) and a Mach-Zehnder modulator. As described above, if the modulator does not have complementary outputs, a beam splitter may be used on the output port to route the modulated laser beam to the respective optical receivers 110 and 117 , shown in FIG. 1 .
Although the invention is illustrated and described herein with reference to specific embodiments, the invention is not intended to be limited to the details shown. Rather, various modifications may be made in the details within the scope and range of equivalents of the claims and without departing from the invention.
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The present invention relates to an optical transmitter that includes an optical modulator configured to modulate an optical signal with a digital data stream, and a heater configured to apply heat to the optical modulator. The optical transmitter also includes an optical receiver configured to receive the modulated optical signal and to convert the modulated optical signal into a received digital data stream. A circuit is configured to compute bit errors in the received digital data stream by comparing the received digital data stream with the digital data stream, and control the heater based on the computed bit errors.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority of U.S. Provisional Patent Application Ser. No. 60/979,302, filed Oct. 11, 2007, which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] This invention relates generally to retro-reflective marker for mounting to roads. More specifically, the invention relates to a plastic protector for retro-reflective markers mounted to roads.
BACKGROUND OF THE INVENTION
[0003] In many regions, plastic retro-reflective road markers are mounted to the road surface to delineate the lanes. Retro-reflective markers mounted directly onto or into the road surface are damaged by the passing of motor vehicle tires over the markers. In particular, heavy motor vehicles such as trailer hauling trucks can cause significant damage and shorten the useable lifetime of retro-reflective road markers placed on the highway.
[0004] Additionally, it has been difficult to accurately position plastic retro-reflective road markers with respect to the road surface. If the retro-reflective marker is placed too low within the pavement surface, the lens is obscured and there is insufficient light reflected from the lens to delineate the lane. In contrast, if the retro-reflective marker extends too far above the road surface, it can become a hazard for vehicles passing over it and suffers premature damage due to tires passing over it.
[0005] Accordingly, it is desirable to have a protector for retro-reflective road markers which properly provides protection for the marker from damage by motor vehicle cars and can be accurately positioned with respect to the road surface.
SUMMARY OF THE INVENTION
[0006] Disclosed is a protector for a retro-reflective road marker that includes a top surface with a generally flat region with an opening where the retro-reflective road marker can be at least partially mounted and a bottom surface oppositely disposed from the top surface. The opening can extend through both the top surface and the bottom surface. The opening could also be bounded by a lip which the reflector is at least partially mounted on. The protector is made from moldable polymer and the top surface is operable to protect the road reflector from motor vehicle tires passing thereover.
[0007] The top surface of the protector has a pair of spaced apart side rails that are parallel to a longitudinal axis of the protector, the side rails extending above the bottom surface. The side rails can each have a flange that extends in a generally outward direction from the longitudinal axis and can provide support for the protector when the bottom surface is mounted to the road. The top surface also has a center portion that extends between the spaced apart side rails, the center portion having a pair of upper surfaces that extend transversely between the side rails and are inclined downwardly toward the opening. The upper surfaces can include a center ramp that is aligned on the longitudinal axis of the protector.
[0008] The upper surfaces could further include deformable studs located along the perimeter of the opening. The reflector could be at least partially mounted to the protector by deforming the studs such that a portion of the material that constitutes the stud overlaps an edge of the reflector. By at least partially mounting the reflector to the protector the reflector is able to move independently from the protector, which reduces the impact experienced by the retro-reflector when a tire passes thereover.
[0009] The bottom surface of the protector can have a generally flat surface operable to be attached to a road surface. The bottom surface can include a cavity that extends from the bottom surface towards the top surface. In some instances, the cavity is generally parallel to the longitudinal axis and extends from the bottom surface towards the top surface and is directly under one of the center ramps. The bottom surface could further include a plurality of tabs extending outwardly from the bottom surface and/or a plurality of textured areas.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a top perspective view of an embodiment of the present invention illustrating the retro-reflector installed onto the protector;
[0011] FIG. 2 is a top perspective view of an embodiment of the present invention illustrating the protector and the retro-reflector prior to installation;
[0012] FIG. 3 a is a cross-sectional view taken along the line 3 - 3 of FIG. 2 illustrating the installation of the retro-reflector onto the protector;
[0013] FIG. 3 b is a cross-sectional view taken along the line 3 - 3 of FIG. 2 illustrating the installation of the retro-reflector onto the protector;
[0014] FIG. 3 c is a cross-sectional view taken along the line 3 - 3 of FIG. 2 illustrating the installation of the retro-reflector onto the protector;
[0015] FIG. 3 d is a cross-sectional view taken along the line 3 - 3 of FIG. 2 illustrating the retro-reflector after it has been installed onto the protector;
[0016] FIG. 4 is a bottom perspective view of an embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0017] The present invention includes a plastic protector for a retro-reflective road marker. As such, the present invention has utility as an article that provides protection to road markers placed on the highway to delineate the lanes.
[0018] The protector for the retro-reflective road marker is a moldable plastic body of material that includes a top surface and a bottom surface. In some instances, the protector is made from a moldable polymer. The moldable polymer can be a hard, durable material such as polycarbonate. The moldable polymer can include any suitable polymer material or combination of polymer materials known to those skilled in the art, illustratively including a material made from 80% acrylonitrile butadiene styrene (ABS) and 20% acrylic. The top surface has an opening wherein the retro-reflective road marker can be mounted and at least two side rails that extend above the retro-reflective road marker when it is mounted onto the protector.
[0019] In some instances, a center ramp can be included between the two side rails, the side rails and/or center ramp affording protection of the retro-reflective road marker from motor vehicle tires passing thereover. The protector can also include a bottom surface that has one or more cavities that extend from the bottom surface towards the top surface. The cavities afford for reduced weight, reduced cross-sectional thickness, and increased bottom surface area of the protector.
[0020] Referring now to FIGS. 1 , 2 and 4 , a low profile protector for a retro-reflective road marker is shown generally at reference numeral 10 . The protector 10 includes a top surface 100 and a bottom surface 200 ( FIG. 4 ).
[0021] The top surface 100 can include a pair of side rails 112 which are spaced apart from each other. Between the side rails 112 is a center portion 150 . The center portion 150 includes a pair of upper surfaces 152 that extend transversely between the side rails 112 and can be inclined downwardly toward an opening 156 . As illustrated in FIGS. 1 and 2 , a retro-reflective road marker R can be mounted to the protector 10 adjacent the opening 156 . The pair of upper surfaces 152 can also include a slot 154 , which affords for the removal of the road reflector R from the protector 10 by use of an instrument that fits at least partially within the slot 154 and applies leverage to the reflector R. For example, a screwdriver can be used to remove the reflector R from the protector 10 by placing the head of the screwdriver (not shown) within the slot 154 and prying up and/or against the reflector R.
[0022] Each of the upper surfaces 152 can include a center ramp 162 . As illustrated in FIG. 2 , the center ramp has a sidewall 163 that extends above the upper surface 152 . It is appreciated that the pair of side rails 112 and the pair of center ramps 162 extend above the upper surface 152 to a height such that the reflector R when mounted within the opening 156 is protected by items rolling thereover. In some instances, the height of the center ramps 162 is equal to a plane extending across top surfaces 114 of the pair of side rails 112 . In other instances, the height of the center ramps 162 is not equal to the height of the plane extending across top surfaces 114 and is less than or greater than the height of the side rails 112 .
[0023] The pair of side rails 112 includes a sidewall 113 , which extends in a generally upward direction from the upper surface 152 to the top surface 114 . In some instances, the top surface 114 is an arcuate surface that increases in height from an end that is proximate to an edge 158 of the center portion 150 . In this manner, a pair of low profile protective surfaces is provided for the protection of the reflector R. The pair of side rails 112 can include a flange 122 that extends in a generally outward direction from a longitudinal axis 110 of the protector 10 , the flange 122 increasing the support area of the bottom surface 200 when the protector 10 is placed on a pavement surface. The flange 122 can also provide additional protection to the protector 10 and the reflector R when impacted from a generally sideward direction by a tire.
[0024] Referring now to FIG. 4 , the bottom surface 200 is a generally flat surface and affords support for the protector 10 on a pavement surface when the bottom surface 200 has been placed in contact with pavement. The bottom surface 200 can include at least one cavity 210 and/or cavity 211 . The cavity 210 and/or 211 extends from the bottom surface 200 towards the top surface 100 . The cavity 210 and/or cavity 211 affords for an increased surface area of the bottom surface 200 and lighter weight for the protector 10 .
[0025] The bottom surface 200 can further include a plurality of tabs 214 which extend outwardly from the bottom surface 200 . The tabs 214 provide for an increased surface area of the bottom surface 200 and contribute to the accurate positioning of the protector 10 with respect to the road surface. In addition, the bottom surface 200 could also include a plurality of textured areas 212 which also increase the surface area of the bottom surface 200 . The textured areas 212 could be comprised of a generally roughened surface, a plurality of ridges which extend outwardly from the bottom surface, or any combination thereof. The increased surface area of the bottom surface 200 afforded by the cavity 210 and/or cavity 211 , tabs 214 and textured areas 212 provides for increased area that adhesive, if used to hold the protector 10 to the pavement surface, can adhere to.
[0026] In some instances, the cavity 210 and/or cavity 211 are included to afford a relatively consistent thickness of the protector 10 in order to decrease shrinkage and/or warpage during manufacture of the protector 10 . As such, the design of a protector for a retro-reflective road marker can use cavities such as those shown in the figures to obtain a generally uniform thickness of the protector in order to reduce shrinkage and/or warpage during the molding process and thereby improve the consistency and/or quality of the product. In addition, the cavity 210 and/or cavity 211 affords for a reduction in the average cross-sectional thickness of the protector 10 . Such a reduction in the average cross-sectional thickness of the protector 10 reduces expansion and contraction of the protector during temperature changes and affords for an increase in the useful lifetime of the protector 10 when in use.
[0027] Turning now to FIGS. 3 a - 3 d , the retro-reflective road marker R is attached to the protector 10 using studs 180 disposed on the upper surfaces of the top surface. The opening 156 has a lip 157 bounding the opening. The lip 157 and the opening 156 are dimensioned such that the retro-reflective road marker R can sit on the lip 157 and not pass through the opening. After the retro-reflective road marker R is placed within the opening 156 and sits on the lip 157 , the studs 180 can be deformed such that a polymer material overlaps the edges of the marker R and holds the marker in place and attached to the protector 10 . The studs 180 can be deformed using heat, pressure, chemicals and combinations thereof. In some instances, the studs can be deformed by using heat from a soldering iron. In other instances, the studs can be deformed using ultrasonic welding. In some instances a bar 300 can have a soldering iron 400 attached thereto, with the soldering iron 400 brought into contact with the studs 180 as illustrated in FIGS. 3 b and 3 c . In other instances, the bar 300 can have two or more soldering irons 400 attached thereto, and the plate 300 can be attached to a movement device 500 that affords back and forth motion, e.g. up and down motion, such as a drill press. Once the protector 10 with the retro-reflector marker R within the opening 156 has been placed proximate to the plate 300 , the movement device 500 can bring the soldering iron 400 into contact with the stud 180 . It is appreciated that if the soldering iron is energized, and thus hot, that the stud 180 can be deformed in such a manner that part of the stud 180 overlaps a portion of the retro-reflector marker R and thereby attaches the reflector R to the protector 10 .
[0028] Once the road reflector marker R is placed within the opening 156 and attached to the protector 10 as illustrated in FIG. 1 , the protector 10 and/or the reflector R can be attached to a pavement surface. In some instances, the protector 10 is attached to a pavement surface using adhesive but the retro-reflective marker R is not directly attached to the pavement surface. In this way, the at least partially mounted retro-reflective marker R is free to vibrate independently from the protector 10 , as seen in FIG. 3 d by the ghost lined marker R. By allowing the marker R to move independently from the protector 10 the impact experienced by the marker R when a tire rolls over the protector 10 and marker R can be reduced. In other instances, the retro-reflective marker R is attached to a pavement surface using adhesive while the protector 10 is not directly attached to the pavement. In this manner, the protector 10 absorbs the energy or impact of a tire rolling thereover and is free to vibrate, thereby allowing the impact to be absorbed by the protector 10 and at least partially isolate said impact from the marker R.
[0029] In this manner, a low profile protector for a retro-reflective road marker is provided. The foregoing drawings, discussion and description are illustrative of specific embodiments of the present invention, but they are not meant to be limitations upon the practice thereof. Numerous modifications and variations of the invention will be readily apparent to those of skill in the art in view of the teaching presented herein. It is the following claims, including all equivalents, which define the scope of the invention.
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Disclosed is a protector for a retro-reflective road marker mounted on a road that includes a top surface that has a generally flat region and a bottom surface oppositely disposed from the top surface. The generally flat region has an opening where the retro-reflective road marker can be at least partially mounted to the protector by deforming studs located along the perimeter of the opening such that the retro-reflective road marker is moveable independent from the protector. The protector is made from a moldable polymer and the top surface is operable to protect the road reflector from motor vehicle tires passing thereover.
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CROSS-REFERENCE
[0001] This application is a divisional of U.S. application Ser. No. 11/836,903 filed Aug. 10, 2007 which is a continuation-in-part of U.S. application Ser. No. 10/804,841 filed Mar. 19, 2004.
GOVERNMENT RIGHTS
[0002] This application was developed under National Science Foundation Small Business Innovative Research Grant No. IIP-0944707.
FIELD OF THE INVENTION
[0003] The present invention relates to a method and apparatus for controlling the hydrodynamics in a plating cell to facilitate more uniform deposition across a workpiece such as a printed circuit board.
BACKGROUND OF THE INVENTION
[0004] The continuing miniaturization of electronic devices is driving the design of interconnects in the direction of finer pitch surface tracks, smaller diameter through holes and vias, and thicker workpieces to provide increased circuit densities (Paunovic, M. and M. Schlesinger, 2000) 1 . This trend has significant implications for the electronics industry which must ensure that the metal electrodeposition process meets the functionality and quality requirements of these advanced workpiece device designs. These workpieces include printed circuit boards, chip scale packages, wafer level packages, printed wiring boards, high density interconnect printed wiring boards, high density interconnect printed circuit boards and the like and these workpieces often have at least one through hole extending from a first surface of the workpiece to a second surface of the workpiece.
[0005] For economies of production, the range of approximate dimensions of workpieces is typically 6 inch by 6 inch, 10 inch by 18 inch, 18 inch by 24 inch, 2 meters by 2 meters, 5 meters by 5 meters, and 200 millimeters and 300 millimeters in diameter. However, these range of dimensions are not unique and are not limiting to the need for controlling the hydrodynamics in a plating cell to facilitate uniform deposition across a workpiece.
[0006] As the hole and via diameter decrease, the workpiece thickness increases, and the workpiece dimension increases, the most notable challenge for the quality of metal electrodeposits is the avoidance of non-uniform copper thickness distribution over board surfaces and within through holes, i.e. the challenge of leveling or throwing power, which can adversely affect the performance of the finished printed wiring board interconnect (Paunovic, M. and M. Schlesinger, 1998) 2 , (Ward, M., D. R. Gabe and J. N. Crosby, 1999a) 3 .
[0007] A number of operating parameters and plating cell attributes influence the uniformity of copper deposition onto a workpiece. This invention concentrates on the influence of electrochemical cell configuration on the uniformity of copper deposition on the board surface, in particular, the influence of cell configuration on solution hydrodynamics, and the ability to generate uniform flow of electrolyte across the surface of the board during the plating operation. FIG. 1 shows a plating cell ( 100 ) which contains a workpiece ( 102 ). Although only one workpiece is shown in this and subsequent drawings, one skilled in the art understands that in actual practice a plurality of workpieces may be contained in the plating cell. For ease of description, the term workpiece is understood to encompass one or more workpieces. The workpiece ( 102 ) in prior art FIGS. 2-3 , 5 , and 7 - 9 is presented as a generally flat panel having at least one generally flat surface for electroplating. Arrows ( 104 ) indicate the desired uniform flow of electrolyte across the entire surface of the workpiece ( 102 ).
[0008] FIG. 2 shows a conventional workpiece ( 102 —shown in a side-view relative to its appearance in FIG. 1 ) plating operation, in which flow of electrolyte is achieved by air sparging. Air bubbles ( 106 ) are created in the electrolyte by blowing air through pipes ( 108 ) which have holes in them. These pipes are positioned on the bottom of the plating cell ( 100 ) beneath the workpiece ( 102 ). The number of pipes ( 108 ) is not limited. The movement of air bubbles ( 106 ) from the bottom to the top of the plating cell ( 100 ) creates solution movement, as indicated by the arrows ( 104 ). However, air sparging can create problems in the plating operation:
the oxygen can oxidize components of the electrolyte, the oxygen can oxidize features and circuit patterns on the workpiece, air bubbles ( 106 ) may become trapped in features in the workpiece ( 102 ), creating areas where copper cannot be deposited, this method can generate low solution movement rates, which can result in burning of the workpiece ( 102 ) at high current densities, and as the air bubbles progress towards the top of the cell they grow in size and can create a non-uniform solution environment from the bottom of the workpiece to the top.
[0014] To avoid the problems associated with air sparging, eductors are being tested for use in plating cells designed for workpieces. Eductors are nozzles which utilize venturi effects to provide up to five times the solution flow velocity output of the pump which feeds the eductors. Eductors may be obtained commercially from a number of sources; one such eductor is marketed under the name Serductor™ (Serductor™ is a trademark of Serfilco, Northbrook, Ill.) 4 .
[0015] One configuration of a prior art plating cell is shown in FIG. 3 . The plating cell ( 100 ) contains a workpiece ( 102 ) which hangs on a rack ( 110 ). Anodes ( 112 ) are positioned on either side of the workpiece ( 102 ) and hang from rails ( 114 ). The workpiece ( 102 ) serves as the cathode. Eductors ( 116 ) are positioned behind the anodes ( 112 ) horizontally opposite (perpendicular to) the surface of the workpiece ( 102 ) (Weber, A., 2003) 5 . Fluid flow is directed (shown by the arrows ( 104 )) from the eductors ( 116 ) between the anodes ( 112 ) to the surface of the workpiece ( 102 ). This type of eductor arrangement leads to impinging fluid flow whereby the solution flow velocity is directed toward the workpiece. Solution flow velocity is accomplished through the anodes by openings or spaces in the anodes.
[0016] However, as shown in FIG. 4 , the use of eductors ( 116 ) can lead to a variation in solution flow velocity across the workpiece ( 102 ) (Chin, D-T. and C-H. Tsang, 1978) 6 , (Hsuch, K-L. and D-T. Chin, 1986a) 7 , (Hsuch, K-L. and D-T. Chin, 1986b) 8 . Fluid flows from the eductor ( 116 ) to the impingement point ( 118 ) on the surface of the workpiece ( 102 ). The fluid flow profile ( 120 ) and jet centerline ( 122 ) are shown. The flow from the eductor ( 116 ) is directly perpendicular to the surface of the workpiece ( 102 ). In region I, referred to as the potential core region, the flow from the eductor ( 116 ) mixes with the surrounding electrolyte. In region II, referred to as the established flow region, the velocity profile ( 124 ) is well established, and the solution flow velocity decreases as a function of distance from the eductor ( 116 ). In region III, referred to as the stagnation region, the velocity decreases to almost zero, and the boundary layer thickness is relatively independent of the radial position near the impingement point ( 118 ) and centerline ( 122 ). In region IV, referred to as the wall jet region, the radial velocity decreases and the boundary layer thickness increases, as a function of distance radially outward from the impingement point ( 118 ). These variations in solution flow velocity, termed the glancing effect, within regions III and IV contribute to variations in the thickness of copper deposited on the surface of the workpiece ( 102 ).
[0017] Efforts to improve the uniformity of flow under the impinging eductor flow configuration have included movement of the workpiece ( 102 ) while maintaining the same distance between the workpiece and the eductor ( 116 ). While the workpiece movement has generally been reported as left and right, the workpiece movement could conceivably be up and down or even at an angle while maintaining the same distance relative to the eductor. The goal of such movement is to produce a time-averaged uniform boundary layer across the workpiece ( 102 ). Such movement, particularly left and right movement is termed knife edge agitation by those skilled in the art. However, knife edge agitation still can result in non-uniformity of the deposited copper and adds complexity to plating cell design. Furthermore, incorporation of knife edge movement in existing workpiece plating lines is difficult and costly.
[0018] An alternative prior art configuration shown in FIG. 5 positions the eductors ( 116 ) below and off to either side of the workpiece, pointing obliquely at the workpiece surface ( 102 ) (Ward, M., D. R. Gabe, and J. N. Crosby, 1998) 9 , (Ward, M., D. R. Gabe, and J. N. Crosby, 1999b) 10 .
[0019] However, as shown in FIG. 6 , the use of angled eductors ( 116 ) can lead to a variation in solution flow velocity across the workpiece ( 102 ) (Chin, D-T., and M. Agarwal, 1991) 11 . Fluid flows from the eductor ( 116 ) to the impingement point ( 118 ) on the surface of the workpiece ( 102 ). The fluid flow profile ( 120 ) and jet centerline ( 122 ) are shown. The flow from the eductor ( 116 ) is at an oblique angle to the surface of the workpiece ( 102 ). In region I, the potential core region, the flow from the eductor ( 116 ) mixes with the surrounding electrolyte. In region II, the established flow region, the velocity profile ( 124 ) is well established, and the solution flow velocity decreases as a function of distance from the eductor ( 116 ). In region III, the stagnation region, the velocity decreases to almost zero, and the boundary layer thickness is relatively independent of the radial position near the impingement point ( 118 ) and centerline ( 122 ). In this case, the stagnation point is shifted from the jet centerline. In regions IV and V, the wall jet regions, the velocity decreases and the boundary layer thickness increases, as a function of distance radially outward from the impingement point ( 118 ). Furthermore, the solution velocity and boundary layer thickness in region IV is different from that in region V. The glancing effect produces variations in solution flow velocity within regions III, IV, and V, and contributes to variations in the thickness of copper deposited on the surface of the workpiece ( 102 ).
[0020] An alternative configuration shown in FIG. 7 positions the eductors ( 116 ) below and off to either side of the workpiece, pointing obliquely across the workpiece ( 102 ) (Weber, A., 2003) 5 . The eductors ( 116 ) on one side of the workpiece ( 102 ) are pointed in one direction, and in the opposite direction on the other side (not shown in FIG. 7 ) of the workpiece ( 102 ). This is intended to create a swirling solution movement around the workpiece ( 102 ). However, the glancing effect described above applies in this case, leading to non-uniform flow of solution across the workpiece ( 102 ).
[0021] An alternative configuration shown in FIG. 8 positions the eductors ( 116 ) directly below the workpiece ( 102 ), pointing directly up so that solution moves past the surface of the workpiece ( 102 ) (Weber, A., 2003) 5 (Carano, M., 2003) 12 . Again, the glancing effect described above applies in this case, due to mixing of the flow profiles from the multiple eductors ( 116 ) positioned below the workpiece ( 102 ). This contributes to non-uniform flow of solution across the workpiece ( 102 ).
[0022] An alternative configuration shown in FIG. 9 positions the eductors ( 116 ) directly below and off to either side of the workpiece ( 102 ), pointing directly up so that solution moves past the surface of the workpiece ( 102 ) (Carano, M., 2003) 12 . The glancing effect described above applies in this case, contributing to non-uniform flow of solution across the workpiece ( 102 ).
[0023] Accordingly, a need exists for a method and apparatus which controls the hydrodynamics within a plating cell ( 100 ), to facilitate uniform distribution of metal onto a workpiece ( 102 ). This invention concentrates on the influence of cell configuration on the uniformity of deposition across the surface of the workpiece ( 102 ) as reflected in a low coefficient of variability.
SUMMARY OF THE INVENTION
[0024] The present invention relates to a method and apparatus for controlling the hydrodynamics in an electroplating cell (hereinafter called a plating cell), to facilitate a more uniform metal deposit distribution across the workpiece using an electrochemical plating process, wherein the metal deposit may be any metal of interest including but not limited to copper, gold, nickel, tin, lead-tin solder. More uniform deposition is a product of more uniform current distribution which is achieved at least in part from more uniform solution flow velocity across the workpiece. Uniform deposition is observed in a coefficient of variability (CoV) that is low by industry standards. In accordance with certain embodiments of the invention CoV less than about 10% and in many cases less than about 7% and in many cases on the order of about 5% or less is achieved.
[0025] One embodiment of the present invention more particularly relates to controlling the hydrodynamics in a plating cell, to facilitate uniform metal deposit distribution across a chip scale package using an electrochemical plating process.
[0026] Another embodiment of the present invention relates to controlling the hydrodynamics in a plating cell, to facilitate uniform metal deposit distribution across a wafer level package using an electrochemical plating process.
[0027] Still another embodiment of the present invention relates to controlling the hydrodynamics in a plating cell, to facilitate uniform metal deposit distribution across a printed wiring board using an electrochemical plating process.
[0028] Another embodiment of the present invention particularly relates to controlling the hydrodynamics in a plating cell, to facilitate uniform metal deposit distribution across a high density interconnect printed wiring board using an electrochemical plating process.
[0029] Still another embodiment of the present invention particularly relates to controlling the hydrodynamics in a plating cell, to facilitate uniform metal deposit distribution across a high density interconnect printed circuit board using an electrochemical plating process.
[0030] Still another embodiment relates to controlling the hydrodynamics in a plating cell to facilitate metal deposition on the walls of a through hole.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] FIG. 1 is a schematic illustration of the cross-section of a plating cell containing a workpiece, with arrows showing the desired uniform solution flow velocity across the surface of the workpiece.
[0032] FIG. 2 is a schematic illustration of a prior art cell depicting the cross-section of a plating cell containing a workpiece and two anodes, with air sparging.
[0033] FIG. 3 is a schematic illustration of prior art depicting the cross-section of a plating cell containing a workpiece and two anodes, with horizontal eductors.
[0034] FIG. 4 is a schematic illustration of the velocity profile of the flow from an eductor directed onto the surface of a workpiece when the eductor is perpendicular to the workpiece in a prior art cell.
[0035] FIG. 5 is a schematic illustration of prior art depicting the cross-section of a plating cell containing a workpiece and two anodes with angled eductors.
[0036] FIG. 6 is a schematic illustration of the velocity profile of the flow from an eductor directed onto the surface of a workpiece, when the eductor flow is at an angle which is not 90° with respect to the workpiece in a prior art cell.
[0037] FIG. 7 is a schematic illustration of prior art depicting the cross-section of a plating cell containing a workpiece and two anodes, with angled eductors.
[0038] FIG. 8 is a schematic illustration of prior art depicting the cross-section of a plating cell containing a workpiece and two anodes, with vertical eductors directly below the workpiece.
[0039] FIG. 9 is a schematic illustration of prior art depicting the cross-section of a plating cell containing a workpiece and two anodes, with vertical eductors below and to either side of the workpiece.
[0040] FIG. 10 is a schematic illustration of the cross-section of a plating cell in accordance with one embodiment of the present invention, viewed from the top, for controlling hydrodynamic flow within the plating cell, to enhance uniformity of electrochemical deposition of copper onto a workpiece. This figure shows the flow of electrolyte from the eductors to the workpiece, and out through a hole in a baffle in the plating cell, to a side chamber, the anodes and anode chambers, the porous fiber cloth on the anode chambers, and the workpiece. The non-conducting shielding on the anode chamber is not shown in FIG. 2 so that the porous fiber cloth can be seen in the figure.
[0041] FIG. 11 provides another schematic illustration of the plating cell shown in FIG. 10 , viewed from a side along the direction 11 - 11 of FIG. 10 . Attributes of the plating cell shown in this figure include eductors, vertical vibration, oscillation perpendicular to the face of the panel workpiece, anode to workpiece distance, use of an anode chamber, use of a porous fiber cloth across the front of the anode chamber, anode non-conducting shielding and use of a baffle.
[0042] FIG. 12 provides another schematic illustration of the plating cell shown in FIGS. 10 and 11 viewed from a side along the direction 12 - 12 of FIG. 10 . This figure shows the flow of electrolyte through the eductors, vertically up past the workpiece, and into a side chamber, from where it is pumped back to the eductors. The anodes and anode chambers are not shown in this view.
[0043] FIG. 13 is a schematic illustration of the thirty-six thickness measurement points on the copper foil, pulled off the stainless steel panel used in the plating experiments described in Examples 2 and 3.
[0044] FIG. 14 is a set of graphs showing the effects of changing the attributes in the plating cell on the uniformity of metal deposition on a flat stainless steel panel. The smaller the coefficient of variance (CoV), the more uniform the metal deposition
[0045] FIG. 15 is a schematic illustration of a plating cell depicting uniform electrolyte flow across both surfaces of the workpiece.
[0046] FIG. 16A is a schematic illustration depicting a plating cell in which the electrolyte flows across the first surface of the workpiece at a flow velocity greater than the flow velocity of the electrolyte flowing across the second surface of the workpiece.
[0047] FIG. 16B is a schematic illustration depicting a plating cell in which the electrolyte flows across the first surface of the workpiece at a flow velocity less than the flow velocity of the electrolyte flowing across the second surface of the workpiece.
[0048] FIG. 17A is a schematic illustration depicting a plating cell in which the electrolyte is injected across the first surface of a workpiece having at least one through hole at a flow velocity greater than the flow velocity of the electrolyte injected across the second surface of the workpiece. The illustration depicts a workpiece with one through hole, but there could be a plurality of through holes in the workpiece. Additionally, it is shown that the electrolyte is drawn through the through hole from the second surface of the workpiece to the first surface by the flow velocity difference.
[0049] FIG. 17B is a schematic illustration depicting a plating cell in which the electrolyte is injected across the first surface of the workpiece at a flow velocity less than the flow velocity of the electrolyte injected across the second surface of the workpiece. Additionally, it is shown that the electrolyte is drawn through the through hole from the second surface of the workpiece to the first surface by the flow velocity difference.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0050] In the following detailed description, reference is made to the accompanying drawing. which form a part hereof, and in which are illustrated specific embodiments in which the invention may be practiced.
[0051] Those skilled in the art will recognize that the invention is not limited to the specific embodiments illustrated in these drawings. In the drawings, the following parts have been identified by the following numbers.
100 . Plating cell 101 . First surface of workpiece 102 . Workpiece 103 . Second surface of workpiece 104 . Arrow indicating electrolyte flow 104 ( a ). Arrow indicating high-velocity electrolyte flow 104 ( b ). Arrow indicating low-velocity electrolyte flow 105 . Arrow indicating direction of electrolyte flow within a through hole 106 . Air bubbles 107 . Through hole 108 . Pipe 110 . Rack 112 . Anode 114 . Rail 116 . Eductor 118 . Impingement point 120 . Fluid flow profile 122 . Jet centerline 124 . Velocity profile 126 . Anode chamber 128 . Porous fiber cloth 130 . Non-conducting shielding 132 . Pump 134 . Manifold 136 . Guide 138 . Baffle 140 . Arrow indicating electrolyte flow 142 . Arrow indicating electrolyte flow 144 . Hole 146 . Baffle 148 . Side chamber 150 . Outlet hole 152 . Arrow indicating vertical vibration 154 . Arrow indicating oscillation 156 . Copper foil 158 . Measuring point
[0086] FIGS. 10 to 12 show one embodiment of the present invention in a series of cross-sectional views. The following detailed description of the preferred embodiments refers to these figures. The plating cell ( 100 ) was designed with a range of attributes for enhancing the uniformity of deposition over the workpiece ( 102 ). The attributes are variable high velocity eductor-induced agitation, lateral oscillation of the workpiece perpendicular its face, use of an anode chamber, variable anode to workpiece distance, variable frequency vertical vibration of the workpiece, and non-conducting shielding of the anodes within the anode chamber. In the plating cell ( 100 ), the workpiece ( 102 ) serves as the cathode for metal deposition.
[0087] The plating cell ( 100 ), which, in one embodiment, holds 1700 liters of bath electrolyte is capable of accommodating one rack or workpiece holder ( 110 ) which holds one workpiece ( 102 ). In this embodiment, the workpiece is 18 inches by 24 inches high. The size of the plating cell ( 100 ), the number of workpieces ( 102 ), dimensions of the workpiece ( 102 ) and other specific details given here relate to a particular embodiment that was evaluated experimentally and are not limiting.
[0088] Sets of anodes ( 112 ) are hung on rails ( 114 , FIGS. 10 and 11 ) on each side of the rack ( 110 ) and facing the workpiece ( 102 ), and may be encased in an anode chamber 126 ( FIGS. 10 and 11 ). These anodes may be plates or, more typically, they are a panel of metallic balls. The anode chamber ( 126 ) may have a porous fiber cloth ( 128 ) between the anodes ( 112 ) and workpiece ( 102 ). The cloth may be formed from a polymeric material. This cloth ( 128 ) spreads the current distribution between the anodes ( 112 ) and the workpiece ( 102 ) such that the anode chamber ( 126 ) acts as a virtual anode. One cloth was obtained from CROSIBLE FILTRATION, located in Moravia, N.Y. 13118. It was specifically a 100% polypropylene filter material. The reported porosity was 2-4 cubic feet per minute. Other filter cloth available has a porosity of 20-30 cubic feet per minute. A wide variety of filter cloths would be acceptable provided they have pores small enough that for the given distance between the cloth and the workpiece the cloth serves as a virtual anode.
[0089] Non-conducting shielding ( 130 ) at the top of the anode chamber ( 126 ) prevents edge effects from affecting the uniformity of copper deposition on the workpiece ( 102 ). The distance from the anode chamber ( 126 ) to the workpiece ( 102 ) is adjustable, with a range varying from about 165 to 300 mm, and preferably from about 210 mm to 250 mm, and more preferably from about 210 to 220 mm.
[0090] In one embodiment two 300 L/min pumps ( 132 ) are used to circulate electrolyte through manifolds ( 134 ) on either side of the plating cell ( 100 ) and through eductors such as ½ in eductors ( 116 ) located horizontally under the anode chambers ( 126 ). In FIGS. 10-12 , three eductors ( 116 ) are shown on each side of the plating cell ( 100 ). In one embodiment, the eductors are spaced on 6 inch centers, but the number of eductors ( 116 ) and the spacing may change from those cited and is not limiting. The number and placement of eductors ( 116 ) should be chosen so as to facilitate uniform flow of electrolyte across the entire surface of the workpiece ( 102 ) as described herein.
[0091] Electrolyte flowing out of the eductors ( 116 ) is directed vertically past the workpiece ( 102 ) by a solution flow velocity dampening member ( 136 ), whereby the variations in electrolyte solution are suppressed. In one embodiment of the invention, the solution flow velocity dampener is a series of shaped guides ( 136 ) located below the workpiece ( 102 ). The use of the shaped guides ( 136 ) directs the solution flow parallel the surface of the workpiece thereby dampening the variations in solution flow velocity described above in the prior art, reducing the glancing effect, and resulting in more uniform flow across the surface of the workpiece ( 102 ). The solution flow velocity dampening members that are useful herein may have a variety of shapes. For example, curved panel sections with various radii of curvature relative to the surface of the workpiece and flat ramps with various incline angles relative to the surface of the workpiece. As taught herein, the optimum configuration for the shaped dampening member is easily determined without undue experimentation by those of ordinary skill in the art. The radius of curvature utilized for one embodiment was 8.25 inches. A useful range may be about 6 to 12 inches for a plating cell in which the distance between the bottom of the shaped guide and the workpiece is approximately 10.5 inches.
[0092] Baffles ( 138 , FIG. 11 ) below each anode chamber ( 126 ) prevent solution from flowing back to the other side of the anode chamber ( 126 ). The velocity of the electrolyte flowing past the workpiece ( 102 ) can be changed by 1) changing the pump ( 132 ) settings and 2) moving the anode chambers ( 126 ) closer to the workpiece ( 102 ). The electrolyte flows vertically up (indicated by arrows 104 ) past the workpiece ( 102 ) and then across (indicated by arrows 140 ) the top of the plating cell ( 100 ) and out (indicated by arrow 142 ) through a hole ( 144 ) in a baffle ( 146 ) in the plating cell ( 100 ) to a side chamber ( 148 ). Solution is suctioned through outlet holes ( 150 ) from the side chamber ( 148 ) through the pump(s) ( 132 ) and back through the manifolds ( 134 ) and out through the eductors ( 116 ). The side chamber ( 148 ) with its enclosed electrolyte and in conjunction with pump(s) ( 132 ) and manifold ( 134 ) serves as an electrolyte supply system. In one embodiment, as electrolyte is pumped through the eductors ( 116 ), electrolyte in the plating cell ( 100 ) is pulled into the eductors ( 116 ) in about a 4:1 ratio (4 parts electrolyte pulled into the eductors ( 116 ) from the plating cell ( 100 ) to 1 part electrolyte pumped through the eductors ( 116 )) to increase the flow of electrolyte past the workpiece ( 102 ). A filter (not shown) in the side chamber ( 148 ) can be used to maintain cleanliness of the electrolyte.
[0093] In some cases, uniformity of metal distribution over the workpiece ( 102 ) can be improved by vibration of the workpiece ( 102 ). Vibration is in the vertical direction as shown by the double-ended arrow ( 152 ) adjacent to the rack ( 110 ) in FIG. 11 . Vibration may be particularly important for workpieces with interconnect features such as fine pitch surface tracks, through holes, vias and the like. Vibration of the workpiece ( 102 ) is accomplished by two horizontally mounted rotary eccentrically weighted devices powered by variable speed motors (not shown) and mounted to each end of the load bar (not shown) to which the rack ( 110 ) is attached. Those skilled in the art understand that other means for accomplishing vibration include, but are not limited to; pneumatic rotary ball device, pneumatic rotary turbine device, electromagnetic linear motion device, pneumatic sliding piston device, and ultrasonic electromagnetic device. The frequency of vibration available using this configuration typically ranges from about 0 to 3570 cycles per minute.
[0094] Oscillation of the workpiece ( 102 ) perpendicular to the anodes ( 112 ), as shown by the double-ended arrow ( 154 ) above the rack ( 110 ) in FIG. 11 , or oscillation of the anodes ( 112 ) perpendicular to the workpiece ( 102 ) or oscillation of both anodes ( 112 ) and workpiece ( 102 ) with respect to each other results in the flow of electrolyte through the holes in the workpiece ( 102 ), improving the current distribution and therefore plated metal distribution on the workpiece ( 102 ). Oscillation may be particularly important for workpieces with interconnect features such as fine pitch surface tracks, through holes, vias and the like. In one embodiment, oscillation of the workpiece ( 102 ) is produced by a positive drive from a variable speed motor-reducer with crank arm and linkage (not shown). Those skilled in the art understand that other means for accomplishing oscillation include, but are not limited to reversing rack and pinion device, off axis side crank device, grooved cam traverse mechanism device, yoke strap eccentric circular cam mechanism device, reversible worm screw jack device, electromechanical linear drive device, and reversible pneumatic or hydraulic cylinder device. The frequency of oscillation can shift from about 6 to 63 cycles per minute with a stroke of about 25 mm, although this range is not limited. This is the method of oscillation employed in this plating cell ( 100 ), although the invention is not limited to this method. Thus in one embodiment, the workpiece ( 102 ) is moved parallel to and/or perpendicular to the anodes ( 112 ).
[0095] In accordance with certain embodiments of the invention, uniformity of metal distribution over the workpiece ( 102 ) can be improved by changing the distance between the anodes ( 112 ) and the workpiece ( 102 ). The distance from the anode chamber ( 126 ) to the workpiece 102 may vary from about 165 to 300 mm, preferably from about 210 mm to 250 mm, and more preferably from about 210 to 220 mm.
[0096] Uniformity of metal distribution over the workpiece ( 102 ) can also be improved by placing non-conducting shielding ( 130 ) at the top of the anode chamber ( 126 ) to reduce edge effects.
[0097] Uniformity of metal distribution over the workpiece ( 102 ) can be further improved by placing a baffle ( 138 ) at the bottom of the anode chamber ( 126 ).
[0098] The invention is particularly useful in plating circuit boards having features such as through holes and vias. Because more uniform deposition is available in accordance with the invention, good plating of the features can be achieved independently of the location of the feature on the workpiece. Thus workpiece having more demanding features to plate can be successfully processed substantially independently of the location of the feature on the workpiece. Problems associated with uneven deposition due to uneven boundary layer due to uneven plating solution flow are minimized and a robust plating technique is provided.
[0099] In electroplating methods in which the electrolyte solution is injected parallel to the surfaces of a workpiece, a equal flow velocity ( 104 ) may be applied across both the first surface ( 101 ) and the second surface ( 103 ) of the workpiece ( 102 ) as shown in FIG. 15 . Another embodiment of the invention enables plating within through holes is illustrated in FIGS. 16A-B and FIGS. 17A-B . The through hole ( 107 ) is representative of one or more through holes. It is understood in the art that the workpiece can have a plurality of through holes. In FIG. 16A , the flow velocity of the electrolyte is adjusted in such a manner that a greater flow velocity ( 104 a ) is applied across the first surface ( 101 ) of the workpiece than the flow velocity ( 104 b ) applied across the second surface ( 103 ). FIG. 16B shows that, alternately, the high-velocity electrolyte flow ( 104 A) can be applied across the second surface ( 103 ) and the low-velocity electrolyte flow ( 104 b ) can be applied to the first surface ( 101 ).
[0100] Although not bound by theory, different flow velocities across the first and second surfaces will generate flow through the through hole as described below. This flow velocity differential will create a high fluid pressure on the surface of the workpiece with the lower flow velocity ( 104 b ) and will create a low fluid pressure on the first surface ( 101 ) having the higher flow velocity ( 104 a ). This pressure differential will induce flow ( 105 ) within the through holes ( 107 ), openings that extend throughout the width of the workpiece ( FIGS. 17A-B ). This will cause the plating bath solution from the high-pressure side to flow through the hole and towards the low-pressure side of the workpiece. This method enables metal deposition within the through holes by providing fresh plating bath and by sweeping away any accumulated by-products.
[0101] A further embodiment of the invention is the use of two or more pumps to modulate the flow velocity of the electrolyte bath solution. The first pump can be used to inject electrolyte bath solution into eductors setup to direct the flow via the shaped guides across the first surface of the workpiece. The second pump can be used to inject bath solution into eductors set up to direct the flow via the shaped guides across the second surface of the workpiece. The first and second pumps can either have controls to regulate their speed (RPM) or have fixed speed capability. Whether variable or fixed, the pumps should be operated such that when utilized in unison they set up a flow velocity differential across either side of the workpiece. In addition, a fixed and a variable pumping devices can be used together, once again, provided that their operation generates the desired flow velocity differential.
[0102] Another embodiment of the invention is the use of valves as a means of modulating flow velocity. In this embodiment valves can be inserted in between the pump and the eductors. The degree of closure of the valves affects the flow velocity of the electrolyte solution prior to entering the eductors. Either a single or multiple pumps may be used in conjunction with the valves. Using a single pump, the conduit from the pump can be bifurcated into two separate conduits: a first conduit for injecting electrolyte bath solution through eductors that direct the solution via the shaped guides across the first surface of a workpiece and a second conduit for directing the bath solution via the shaped guides across the second surface. Valves can be placed in either one or both of the conduits. The valves can be adjusted such that the requisite flow differential is established. Multiple pumps can be utilized in the same way as described in the previously stated embodiment with the addition of valves to provide a further means for regulating the flow velocity.
[0103] An even further embodiment of the invention is the use of one or more flange connections in the conduits. Just as the valves in the above embodiment, the flange connections are placed in between the pump and the eductors. In between the connections a disc with an orifice can be inserted that restricts the diameter of the conduit. Orifice size also contributes to the flow velocity across the workpiece. Therefore the flange connectors can be utilized with one or more pumps to regulate the flow velocity across the workpiece. As in the case of the valve when using a single pump, the flange connectors can be placed in either the first conduit or second conduit or in both. While the valves may be adjustable and therefore their affect on flow velocity adjustable, the flange connections' affect on fluid velocity is limited by the size of the orifice selected. Even so, the flange connections can serve as either the sole means of regulating flow velocity or as an additional means in conjunction with pumps and valves.
[0104] The invention will be illustrated by the following examples, which are intended to be illustrative and not limiting.
Example 1 (Comparison)
[0105] This example illustrates the use of the plating cell ( 100 ) with air sparging to deposit copper onto a workpiece ( 102 ), to demonstrate the prior art.
[0106] The experiments were conducted in the plating cell ( 100 ) shown in FIG. 2 . An acid copper sulfate electrolyte containing ˜97 g/L CuSO 4 , 210-215 g/L of concentrated H 2 SO 4 , ˜63 ppm CF, and 350 ppm polyethylene glycol (PEG) was used as the copper electroplating bath. As known by those skilled in the art, the chloride/PEG acts as a suppressor and is not difficult to control. The plating bath does not contain difficult-to-monitor/control additives such as brighteners and/or levelers and hence the bath is considered “additive-free.” The plating bath temperature was maintained in the range of 22 to 25° C.
[0107] The initial experiments for plating cell ( 100 ) characterization were conducted on a stainless steel panel (450 mm×600 mm), as a workpiece ( 102 ). The copper plating process was controlled by DC current at 25 A/ft 2 (provided by a PE86 dual output rectifier) to obtain a copper film with a thickness of about 25 micrometers on both surfaces of the stainless steel panel
[0108] After each test, copper foils ( 156 ) that plated on both sides of the stainless steel panel workpiece ( 102 ) were peeled off to analyze the copper thickness distribution. FIG. 13 illustrates the position of each measuring point ( 158 ) on the copper foil ( 156 ). There were thirty-six equi-spaced measuring points on the foil ( 156 ) and the edge points were 38 mm away from the foil ( 156 ) side. The uniformity of copper deposits on the steel panel workpiece ( 102 ) surface was defined by the ratio of the standard deviation to the average copper thickness, expressed on a percent basis ((σ/ā)×100%), that is, the coefficient of variation (CoV)). The quantity σ is the standard deviation based on the measuring points; and ā is the mean thickness that is given by: ā=Σh i /n where n is the number of measuring points and h i is the copper thickness at each measuring point. For these experiments, n=36. The smaller the value of the CoV, the more uniformly is current distributed over the steel panel workpiece ( 102 ) surface, and the more uniformly is metal distributed over the steel panel workpiece ( 102 ) surface. The value of CoV for a conventional workpiece with dimensions of about 450 mm×600 mm in the electronics industry is about 10% to 12% although more typical values may be about 15%.
[0109] In this example the CoV value determined from analysis of the copper foil was 13.99%. The thickness of the copper deposit was measured with a micrometer.
Example 2
[0110] This example illustrates the use of the plating cell ( 100 ) to deposit copper uniformly onto a workpiece ( 102 ), to demonstrate the effects of the various attributes of the plating cell ( 100 ) of the present invention, such as flow rate of electrolyte through the eductors ( 116 ), anodes ( 112 ) to workpiece ( 102 ) distance, oscillation ( 154 ) of the workpiece ( 102 ), and vibration ( 152 ) of the workpiece ( 102 ).
[0111] The experiments were conducted in the plating cell ( 100 ) shown in FIGS. 10 to 12 . An acid copper sulfate electrolyte containing ˜97 g/L of CuSO 4 , 210-215 g/L of concentrated H 2 SO 4 , ˜63 ppm Cl − , and 350 ppm polyethylene glycol (PEG) was used as the copper electroplating bath for all experiments. The chloride/PEG is termed a suppressor and is not difficult to control. The plating bath does not contain difficult-to-monitor/control additives such as brighteners and/or levelers and hence we consider the bath as “additive-free.” The plating bath temperature was maintained in the range of 22 to 25° C.
[0112] The initial experiments for plating cell ( 100 ) characterization were conducted on a stainless steel panel (450 mm×600 mm), as a workpiece ( 102 ). The cell operating parameters, which were eductor ( 116 ) flow rate (low flow designates flow with a pump setting about one-half the maximum (high) flow), oscillation ( 154 ) frequency, vibration ( 152 ) frequency, and anode ( 112 ) to steel panel workpiece ( 102 ) distance, were selected as factors to evaluate the effect of plating cell ( 100 ) configuration on the current distribution over the panel workpiece ( 102 ) surface. The copper plating process was controlled by DC current at 25 A/ft 2 (provided by a PE86 dual output rectifier) to obtain a copper film with a thickness of about 25 micrometers. In all experiments, the anode chamber ( 126 ) was used, as was the porous fiber cloth ( 128 ), and 152 mm of anode non-conducting shielding ( 130 ).
[0113] After each test, copper foils ( 156 ) that plated on both sides of the stainless steel panel workpiece ( 102 ) were peeled off to analyze the copper thickness distribution. FIG. 13 illustrates the position of each measuring point ( 158 ) on the copper foil ( 156 ). There were thirty-six equi-spaced measuring points on the foil ( 156 ) and the edge points were 38 mm away from the foil ( 156 ) side. The uniformity of copper deposits on the steel panel workpiece ( 102 ) surface was defined as described in Example 1 above, with n=36 in this example also. The desired percentage value of CoV for the cell conditions in the electronics industry and more particularly printed circuit board industry for panels of approximately this size is less than 10%.
[0114] The experimental matrix, designed using a full factorial method, is listed in Table 1. MINITAB software was used to design the factorial method, although other methods could be used. The target performance criterion for the initial cell experimental study was to plate approximately 25 micrometers of copper over the steel panel workpiece ( 102 ) surface and evaluate the uniformity of copper thickness distribution. As shown in Table 1, a CoV of less than 10% was achieved under the plating cell operating conditions of Test 5 to Test 12, and the lowest CoV value was achieved in Test 5.
[0000]
TABLE 1
Factorial Matrix and CoV Results for Example 2.
Test
Oscillation
Vibration
Distance*
CoV
No.
Flow
(cycles/min)
(cycles/min)
(mm)
(%)
1
High
26
0
290
12.11
2
High
12
0
290
12.55
3
High
12
1400
290
12.12
4
High
26
1400
290
12.35
5
High
26
1400
213
7.72
6
High
26
0
213
8.57
7
High
12
1400
213
9.54
8
High
12
0
213
9.19
9
Low
12
0
213
9.76
10
Low
12
1400
213
8.31
11
Low
26
1400
213
9.01
12
Low
26
0
213
9.54
13
Low
26
0
290
11.42
14
Low
26
1400
290
16.12
15
Low
12
1400
290
11.55
16
Low
12
0
290
11.13
*Distance refers to the anode-to-workpiece distance.
[0115] FIG. 14 shows a graph of the data from the factorial matrix. The graph plots the CoV versus the changes in each of the operating parameters and shows which operating parameter has the strongest influence on the uniformity of copper thickness across the surface of the stainless steel panel workpiece ( 102 ). FIG. 14 shows that the distance between the anodes ( 112 ), which controls the anode ( 112 ) to steel panel workpiece ( 102 ) distance, has the strongest influence on the uniformity of copper distribution over the steel panel workpiece ( 102 ), compared to the other parameters. However, one skilled in the art would recognize that oscillation and vibration may be important when the workpiece incorporates interconnects with fine pitch lines, through holes, vias and the like. These data would also indicate that even closer anode ( 112 ) to steel panel workpiece ( 102 ) spacing may offer further improvements in copper uniformity.
[0116] These observations are confirmed by the data in Table 1 which show that a more uniform copper thickness distribution (low CoV) can be obtained by using a closer distance between the anode chamber ( 126 ) and the stainless steel panel workpiece ( 102 ). The Test 5 plating cell configuration gave the most uniform copper thickness distribution over the steel panel workpiece ( 102 ) surface, with the closest anode ( 112 ) to steel panel workpiece ( 102 ) distance, at a high flow rate, high oscillation frequency and high vibration frequency.
[0117] Based on the test results shown in FIG. 14 , the effect of oscillation ( 154 ) and vibration ( 152 ) are unclear, although they suggest that higher vibration ( 152 ) and oscillation ( 154 ) frequencies will improve the uniformity of metal on the steel panel workpiece ( 102 ). The effects of oscillation ( 154 ) and vibration ( 152 ) might be seen more clearly on a patterned workpiece which has interconnect features such as fine pitch lines, through holes, and vias and the like.
Example 3
[0118] This example illustrates the use of the plating cell ( 100 ) to deposit copper uniformly onto a workpiece ( 102 ), to demonstrate further effects of the various attributes of the plating cell ( 100 ), such as flow rate of electrolyte through the eductors ( 116 ), anodes ( 112 ) to workpiece ( 102 ) distance, use of an anode chamber ( 126 ), use of a porous fiber cloth ( 128 ), use of additional non-conducting shielding ( 130 ), and use of a baffle ( 138 ) under the anode chamber, on the current distribution over the panel workpiece ( 102 ) surface.
[0119] The experiments were conducted in the plating cell ( 100 ) shown in FIGS. 10 to 12 . An acid copper sulfate electrolyte containing ˜97 g/L of CuSO 4 , 210-215 g/L of concentrated H 2 SO 4 , ˜63 ppm Cl − , and 350 ppm polyethylene glycol (PEG) was used as the copper electroplating bath for all experiments. The chloride/PEG acts as a suppressor and is not difficult to control. The plating bath does not contain difficult-to-monitor/control additives such as brighteners and/or levelers and hence we consider the bath as “additive-free.” The plating bath temperature was maintained in the range of 22 to 25° C.
[0120] The initial experiments for cell characterization were conducted on a stainless steel panel (450 mm×600 mm), as a workpiece ( 102 ). The copper plating process was controlled by DC current at 25 A/ft 2 (provided by a PE86 dual output rectifier) to obtain a copper film with a thickness of about 25 micrometers.
[0121] After each test, copper foils ( 156 ) that plated on both sides of the stainless steel panel workpiece ( 102 ) were peeled off to analyze the copper thickness distribution. FIG. 13 illustrates the position of each measuring point ( 158 ) on the copper foil ( 156 ). There were thirty-six equi-spaced measuring points on the foil ( 156 ) and the edge points were 38 mm away from the foil ( 156 ) side. The uniformity of copper deposits on the steel panel workpiece ( 102 ) surface was defined as described in Example 1 above, with n=36 in this example also. The desired percentage value of CoV for the cell conditions in the electronics and more particularly printed circuit board industry is less than 10%.
[0122] The experimental matrix and results are listed in Table 2. The target performance criterion for the experimental study was to plate approximately 25 micrometers of copper over the steel panel workpiece ( 102 ) surface and evaluate the uniformity of copper thickness distribution.
[0000]
TABLE 2
Experimental Matrix and CoV Results for Example 3.
5C
Same as Test 5 but with 203 mm distance between
9.47
anode and panel
5D
Same as Test 5 but with 191 mm additional shielding
5.24
on top of anode chamber
5E
Same as Test 5 but no anode chamber in cell
14.81
SF
Same as Test 5 with anode chamber without fiber cloth
11.61
5CG
Test 5C conditions, adding baffle under the bottom
8.31
of each anode chamber
5DH
Test SD conditions, adding baffle under the bottom
5.18
of each anode chamber
5DI
Test 5D conditions with fiber cloth (did not dummy
5.45
the bath)
5DJ
Test 5D conditions with fiber cloth
5.39
11
Low flow, 26 cycles/min oscillation, 1400 cycles/min
9.01
vibration, 213 mm distance between anode center
and panel, anode chamber with fiber cloth, 152 mm
shielding on top of anode chamber.
11C
Same as Test 11 but low flow and 203 mm distance
10.06
between anode center and panel
11E
Same as Test 1.1 but low flow, no anode chamber in cell
14.11
[0123] Table 2 shows the effect of each plating cell attribute. Comparing Test 5 with 5C and Test 11 with 11C shows that decreasing the distance between the anode ( 112 ) and panel workpiece ( 102 ) from 213 to 203 mm decreased the uniformity (increased the CoV) of metal deposition across the steel panel workpiece ( 102 ). Comparing Test 5 with 5D shows that increasing the non-conducting shielding ( 130 ) at the top of the anode chamber ( 126 ) from 152 to 191 mm improved the uniformity (decreased the CoV) of metal deposition across the steel panel workpiece ( 102 ). Comparing Test 5 with 5E and Test 11 with 11E shows that removing the anode chambers ( 126 ) from the cell decreased the uniformity (increased the CoV) of metal deposition across the steel panel workpiece ( 102 ). Comparing Test 5 with 5F shows that removing the porous fiber cloth ( 128 ) from the anode chamber ( 126 ) decreased the uniformity (increased the CoV) of metal deposition across the steel panel workpiece ( 102 ). Comparing Test 5C with 5CG and Test 5D with 5DH shows that adding a baffle ( 138 ) under the bottom of each anode chamber ( 126 ) improved the uniformity (decreased the CoV) of metal deposition across the steel panel workpiece ( 102 ). Comparing Test 5D with SDI and 5DJ shows that changing the porous fiber cloth ( 128 ) to that of a different manufacturer decreased the uniformity (increased the CoV) of metal deposition across the steel panel workpiece ( 102 ). In summary, the best result was achieved in Test 5DH, which ran at high flow, 26 cycles/min oscillation, 1400 cycles/min vibration, 213 mm distance between anode ( 112 ) and steel panel workpiece ( 102 ), used an anode chamber ( 126 ) with a porous fiber cloth ( 128 ), had 191 mm non-conducting shielding ( 130 ) on top of the anode chamber ( 126 ), and had a baffle ( 138 ) attached below both anode chambers ( 126 ).
[0124] The invention having now been fully described, it should be understood that it might be embodied in other specific forms or variations without departing from its spirit or essential characteristics. Accordingly, the embodiments described above are 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 intended to be embraced therein.
REFERENCES
[0000]
1 M. Paunovic and M. Schlesinger (2000), Modern Electroplating , Wiley Inc. NY.
2. M. Paunovic and M. Schlesinger (1998), Fundamentals of Electrochemical Deposition , Wiley Inc. NY.
3 Ward, M., D. R. Gabe and J. N. Crosby (1999a), Proc. European PCB Convention , Munich, Germany, November.
4 Serductor™ is a trademark of Serfilco, Northbrook, Ill.
5 Weber, A. (2003), The Importance of Plating Cell Design and Hydrodynamics for Repeatable Product Quality in Latest Generation Vertical Platers for the Galvanic Industry, IPC Printed Circuits Expo 2003, Long Beach, Calif.
6 Chin, D-T. and Tsang, C-H. (1978), Mass Transfer to an Impinging Jet Electrode, J. Electrochem. Soc., 125, 9, pp 1461-1470.
7 Hsuch, K-L. and D-T. Chin (1986a), Mass Transfer to a Cylindrical Surface from an Unsubmerged Impinging Jet, J. Electrochem. Soc., 133, 1, pp 75-81.
8 Hsuch, K-L. and D-T. Chin (1986b), Mass Transfer of a Submerged Impinging Jet on a Cylindrical Surface, J. Electrochem. Soc., 133, 9, pp 1845-1850.
9 Ward, M., D. R. Gabe, and J. N. Crosby (1998), Novel Agitation for PCB Production: Use of Eductor Technology, Trans IMF, 76, 4, pp 121-126.
10 Ward, M., D. R. Gabe, and J. N. Crosby (1999b), Exploitation of Eductor Agitation in Copper Electroplating, Proc. SURFIN/ 99, June 21-24, Cincinnati, Ohio.
11 Chin, D-T. and M. Agarwal (1991), Mass Transfer from an Oblique Impinging Slot Jet, J. Electrochem. Soc., 138, 9, pp 2643-2650.
12 Carano, M. (2003), Hole Preparation & Metallization of High Aspect Ratio, High Reliability Back Panels, Part-2, Circuitree , February, pp 10-22.
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A method and apparatus for establishing more uniform deposition across one or more faces of a workpiece in an electroplating process. The apparatus employs eductors in conjunction with a flow dampener member and other measures to provide a more uniform current distribution and a more uniform metal deposit distribution as reflected in a coefficient of variability that is lower than conventional processes.
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TECHNICAL FIELD
[0001] The present invention relates to a catalytic hydrocarbon reformer for converting a hydrocarbon stream to a gaseous reformate fuel stream comprising hydrogen; and more particularly, to a fast light-off catalytic reformer; and most particularly to a method and apparatus for rapid vaporization of liquid hydrocarbon fuel during cold start-up of a hydrocarbon reformer. The present invention is useful for rapidly providing reformate as a fuel to a fuel cell, especially a solid oxide fuel cell, or to an internal combustion engine or vehicle exhaust stream to improve emissions reduction performance.
BACKGROUND OF THE INVENTION
[0002] A catalytic hydrocarbon fuel reformer converts a fuel stream comprising, for example, natural gas, light distillates, methanol, propane, naphtha, kerosene, gasoline, diesel fuel, bio-diesel or combinations thereof, and air, into a hydrogen-rich reformate fuel stream comprising a gaseous blend of hydrogen, carbon monoxide, and nitrogen (ignoring trace components). In a typical reforming process, the raw hydrocarbon is percolated with oxygen in the form of air through a catalyst bed or beds contained within one or more reactor tubes mounted in a reformer vessel. The catalytic conversion process is typically carried out at elevated catalyst temperatures in the range of about 700° C. to about 1100° C.
[0003] The produced hydrogen-rich reformate stream may be used, for example, as the fuel gas stream feeding the anode of an electrochemical fuel cell. Reformate is particularly well suited to fueling a solid-oxide fuel cell (SOFC) system because a purification step for removal of carbon monoxide is not required as is the case for a proton exchange membrane (PEM) fuel cell system.
[0004] The reformate stream may also be used in spark-ignited (SI) or diesel engines. Reformate can be a desirable fuel or fuel-additive; the reformate stream also can be injected into the vehicle exhaust to provide benefits in reducing vehicle emissions. Hydrogen-fueled vehicles are of interest as low-emissions vehicles because hydrogen as a fuel or a fuel additive can significantly reduce air pollution and can be produced from a variety of fuels. Hydrogen permits a SI engine to run with very lean fuel-air mixtures that greatly reduce production of NOx. As a gasoline additive, small amounts of supplemental hydrogen-rich reformate may allow conventional gasoline-fueled internal combustion engines to reach nearly zero emissions levels. As a diesel fuel additive, supplemental reformate may enhance operation of premixed combustion in diesel engines. Reformate can be injected into the vehicle exhaust stream to improve NOx reduction and/or as a source of clean chemical energy for improved thermal management of exhaust components (for example, NOx traps, particulate filters and catalytic converters).
[0005] Fuel/air mixture preparation constitutes a key factor in the reforming quality of catalytic reformers, and also the performance of porous media combustors. A problem in the prior art has been how to vaporize fuel completely and uniformly, especially at start-up when the apparatus is cold. Inhomogeneous fuel/air mixtures can lead to decreased reforming efficiency and reduced catalyst durability through coke or soot formation on the catalyst and thermal degradation from local hot spots. Poor fuel vaporization can lead to fuel puddling, resulting in uncertainty in the stoichiometry of fuel mixture. Complete and rapid fuel vaporization is a key step to achieving a homogeneous gaseous fuel-air mixture.
[0006] Fuel vaporization is especially challenging under cold start and warm-up conditions for a fuel reformer. In the prior art, it is known to vaporize injected fuel by preheating the incoming air stream to be mixed with the fuel, or by preheating a reformer surface for receiving a fuel spray. However, none of the prior art approaches is entirely successful in providing reliable, complete vaporization of injected liquid fuel.
[0007] What is needed is a method and apparatus for rapidly heating and vaporizing liquid hydrocarbon fuel injected into a reformer assembly, even when the overall assembly is in a cold start-up condition.
[0008] It is a primary object of the invention to prevent coking of the housing and catalyst of a hydrocarbon reformer, especially at start-up of the reformer.
SUMMARY OF THE INVENTION
[0009] A catalytic reformer assembly and methods of operation, including fast start-up, are provided. The reformer assembly includes a fuel vaporizer in the form of an electrically-conductive, metallic element having a very high surface area. At start-up of the reformer, electric current is passed through the element to heat it by resistance heating, providing a high-temperature, high-surface area environment for fuel vaporization. Preferably, the electric current is started before starting fuel flow to preheat the element. The fuel is sprayed either onto or through the heated metallic element, preferably before the fuel is mixed with incoming air to minimize convective cooling by the air and to reduce the pressure drop in the fuel flow. As the reformer warms up, energy from the reforming process heats the metallic element via radiation and/or conduction such that electric power is needed only during the start-up phase. A control circuit regulates the amount and duration of electric power supplied to the element. The invention contemplates that the heating element may remain energized after reforming has begun and/or may be continuously de-energized and re-energized as needed during the catalytic reforming.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The present invention will now be described, by way of example, with reference to the accompanying drawings, in which:
[0011] FIG. 1 is an isometric view, partially in section, of a first prior art catalytic reformer assembly;
[0012] FIG. 2 is a schematic cross-sectional view of a second prior art catalytic hydrocarbon reformer assembly;
[0013] FIG. 3 is a schematic cross-sectional view of a first embodiment of a catalytic hydrocarbon reformer assembly in accordance with the invention;
[0014] FIG. 4 is a schematic cross-sectional view of a second embodiment of a catalytic hydrocarbon reformer assembly in accordance with the invention; and
[0015] FIG. 5 is a set of graphs showing the electrical characteristics of an exemplary electrically heated metallic fuel vaporizer in accordance with the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0016] Referring to FIG. 1 , a first prior art fast light-off catalytic reformer assembly 01 includes a reactor 10 having an inlet 12 in a first end for receiving a flow of fuel 11 and a flow of air 13 , shown as combined fuel-air mixture 14 . Reactor 10 may be any shape, but preferably comprises a substantially cylindrical reactor tube. Reforming catalyst 16 is disposed within reactor 10 . A protective coating or firewall (not shown) may be disposed about catalyst 16 .
[0017] During operation, fuel-rich mixture 14 comprising air 13 and hydrocarbon fuel 11 such as natural gas, light distillates, methanol, propane, naphtha, kerosene, gasoline, diesel fuel, or combinations thereof, is converted by catalyst 16 to a hydrogen rich reformate fuel stream 18 that is discharged through outlet 20 .
[0018] Ignition device 22 is disposed within reactor 10 to ignite fuel/air mixture 14 as desired. Heat generated by this reaction is used to provide fast light-off (i.e., rapid heating) of reforming catalyst 16 at start-up of the reformer. Ignition device 22 is disposed within the reactor 10 upstream of reforming catalyst 16 , i.e., between inlet 12 and reforming catalyst 16 . Ignition device 22 may be any device suitable for initiating exothermic reactions between fuel and air 14 , including, but not limited to, a catalytic or non-catalytic substrate, such as a wire or gauze as shown in FIG. 1 , for receiving electric current from a voltage source; a spark plug; a glow plug; or any combination thereof. An associated control system 30 selects and maintains the appropriate fuel and air delivery rates and operates the ignition device 22 so as to achieve fast light off of the reforming catalyst 16 at start-up and to maintain catalyst 16 at a temperature sufficient to optimize reformate 18 yield.
[0019] Prior art reformer assembly 01 has no provision for preheating of either incoming fuel 11 or air 13 and thus is not optimally directed to capability for providing either fast light-off or steady-state operating conditions for generation of reformate 18 .
[0020] Referring to FIG. 2 , a second prior art fast light-off catalytic fuel reformer 50 is seen to be adapted from reformer 01 , as shown in FIG. 1 , and includes means for shortening the light-off induction period of the reformer. Components thereof having identical function are identically numbered, and those having similar or improved function are identically numbered with a prime indicator. New components bear new numbers.
[0021] In second prior art reformer 50 , inlet 12 is eliminated and that end of reactor 10 is blocked by end plate 52 . A jacket 54 is provided concentric with reactor 10 and defining an annular chamber 56 therebetween which is closed at both axial ends. Chamber 56 communicates with reforming chamber 58 within reactor 10 via a plurality of openings 60 formed in the wall of reactor 10 . Air 13 for combustion and for reforming enters reformer 50 via inlet duct 62 formed in the wall of jacket 54 . Combustion fuel 11 is injected by a fuel injector 66 mounted in end 52 directly into reforming chamber 58 during combustion mode where the fuel mixes with air 13 entering from chamber 56 via openings 60 . An igniter 22 ′, preferably a spark plug or other sparking device, is disposed through end 52 of reactor 50 into chamber 58 . Reforming catalyst 16 is disposed in reactor 10 downstream of the flow of mixture 14 through chamber 58 . Downstream of catalyst 16 is a heat exchanger 70 . Intake air 13 is passed through a first side of heat exchanger 70 and hot combustion or reformate gases 18 ′ exiting catalyst 16 are passed through a second side, thus heating intake air 13 .
[0022] Referring to FIG. 3 , an improved reformer assembly 150 in accordance with the invention is structurally similar in many respects to prior art assembly 50 as shown in FIG. 2 . Components thereof having identical function are identically numbered. New components bear new numbers in the 100 series.
[0023] End plate 52 a closes the inlet end of reactor 10 . A jacket 54 is provided concentric with reactor 10 and defining an annular chamber 56 therebetween which is closed at both axial ends by end plates 52 a , 52 b . Chamber 56 communicates with reforming chamber 58 within reactor 10 via a plurality of openings 60 formed in the wall of reactor 10 . Air 13 for combustion and for reforming enters reformer 50 via inlet duct 62 formed in the wall of jacket 54 . Combustion fuel 11 is injected by a fuel injector 66 mounted in end 52 a directly into reforming chamber 58 where the fuel mixes with air 13 entering from chamber 56 via openings 60 . An igniter 22 ′, preferably a spark plug or other sparking device, is disposed through a wall of reactor 10 into chamber 58 . Reforming catalyst 16 is disposed in reactor 10 downstream of the flow of mixture 14 through chamber 58 . Downstream of catalyst 16 is a heat exchanger 70 . Intake air 13 is passed through a first side of heat exchanger 70 and hot gases (either combustion products at start-up or reformate at steady state operation) 18 ′ exiting catalyst 16 are passed through a second side, thus heating intake air 13 .
[0024] The novel improvement in reformer assembly 150 consists in a fuel vaporizer 172 disposed within reactor 10 transversely of the flow path of fuel 11 being injected into reactor 10 . Vaporizer 172 preferably comprises an electrically-conductive metallic material in the form of a foam or spun/woven fibers to present a very large surface area for receiving and vaporizing liquid fuel spray from fuel injector 66 . As desired, and especially at reformer start-up, an electric circuit 174 is controllably imposed across vaporizer 172 which is electrically insulated from reactor 10 . The material from which vaporizer 172 is formed is selected to have a moderate ohmic resistance such that the vaporizer is resistively heated very quickly to a desired elevated operating temperature sufficient to continuously vaporize injected fuel for as long as is desired. The material must also be chemically inert at the operating environment of the reactor. Presently preferred materials include nickel and nickel alloys, although it is believed that other inert alloys can be made available which have still higher resistivity and thus even more rapid heating to even higher temperatures; and all such materials are fully comprehended by the invention.
[0025] After reformer assembly 150 is sufficiently warmed to begin fuel reforming, the heat thrown off by the exothermic reforming process can keep vaporizer 172 hot enough by radiation and conduction to continue vaporizing without requiring continued electric resistive heating.
[0026] Referring to FIG. 4 , a second embodiment 250 of an improved catalytic hydrocarbon reformer assembly in accordance with the invention is similar in most respects to first embodiment 150 . However, the vaporizer 272 energized by circuit 274 is disposed in cylindrical form longitudinally along (and insulated from) the walls of reactor 10 rather than being disposed across the reactor as in first embodiment 150 ; and igniter 22 is returned to a prior art position in end plate 52 a.
[0027] This arrangement has at least two advantages. First, vaporizer 272 may be placed in direct contact 276 with catalyst bed 16 , resulting in a rapid transfer of heat by conduction from the catalyst bed to the vaporizer (whereas embodiment 150 must rely predominantly on radiative heating of vaporizer 172 ). Second, the cylinder of vaporizer 272 presents a very large macro-surface area for impingement of liquid fuel 11 and also shields the wall of reactor 10 from direct exposure to the fuel spray, which is known in the prior art to cause coking of the reactor.
[0028] A minor disadvantage of the arrangement shown in FIG. 4 is that the heating load on the vaporizer is increased because the vaporizer is now fully exposed to both incoming air 13 and mixture 14 , both of which are cooling forces.
[0029] Referring to FIG. 5 , electrical operation curves as a function of time from start-up are shown for an exemplary nickel foam vaporizer in accordance with the invention. Curve 302 shows a voltage increase applied across vaporizer 172 , 272 over 5 seconds. Curve 304 shows the corresponding temperature rise as calculated from electrical resistance of the vaporizer. Curve 306 shows the applied current, and curve 308 shows the resulting applied power. Finally, curve 310 shows the actual measured temperature rise of vaporizer 172 , 272 ; it is seen that the vaporizer can reach a temperature of at least 200° C. within 6 seconds and can maintain this temperature thereafter.
[0030] Reformer assembly 150 , 250 may be operated in any of several ways, depending upon a specific application or upon the operational status of the reformer.
[0031] In a first method in accordance with the invention, during start-up from a cold start, fuel 11 is spray injected by fuel injector 66 into vaporizer 172 , 272 wherein the fuel is instantly vaporized by contact with the hot material of the vaporizer. The vaporized fuel passes into reactor 10 , is mixed with air 13 in a near-stoichiometric ratio, and ignited by igniter 22 ′ to form hot exhaust gases 18 ′ which immediately begin to heat the first side of heat exchanger 70 . Preferably, circuit 174 , 274 is energized for a few seconds prior to commencing injection of fuel to preheat the vaporizer to vaporization temperature.
[0032] In one aspect of the invention, after combustion has proceeded for a few seconds, ignition by igniter 22 , 22 ′ is terminated, the fuel ratio is made richer in fuel, and the unburned fuel/air mix 14 is passed into the reforming catalyst 16 . Fuel flow is also terminated for a brief period to cause the preheat flame to be extinguished prior to commencing injection leading to the richer fuel mixture. Once catalytic reforming has begun, vaporizers 172 , 272 may be de-energized or allowed to remain energized depending upon the needs of the reformer. Also, the vaporizer may be controllably energized and de-energized during operation of the catalytic reformer.
[0033] The present fast light-off catalytic reformer assembly and methods of operation rapidly produce high yields of reformate fuel without significant coking or hot-spotting of the reactor or reforming catalyst during start-up. The produced reformate 18 ′ may be bottled in a vessel or used to fuel any number of systems operating partially or wholly on reformate fuel. Such power generation systems for reformer assembly 150 may include, but are not limited to, engines such as spark ignition engines, hybrid vehicles, diesel engines, fuel cells, particularly solid oxide fuel cells, or combinations thereof. The present fast light-off reformer and method may be variously integrated with such systems, as desired. For example, the present fast light-off reformer may be employed as an on-board reformer for a vehicle engine operating wholly or partially on reformate, the engine having a fuel inlet in fluid communication with the reformer outlet for receiving reformate 118 therefrom.
[0034] The present fast light-off reformer and methods are particularly suitable for use as an on-board reformer for quickly generating reformate 118 for initial start-up of a system. The present reformer and methods are particularly advantageous for hydrogen cold-start of an internal combustion engine, providing a supply of hydrogen-rich reformate which allows the engine exhaust to meet SULEV emissions levels immediately from cold-start. The present fast light-off reformer and methods are also particularly suitable for use as an on-board reformer for quickly generating reformate for use to improve premixed combustion in a diesel engine. A third application for with the present fast light-off reformer and methods are suitable comprises injecting the reformate into the vehicle exhaust stream to improve NOx reduction and/or as a source of clean chemical energy for improved thermal management of exhaust components (for example, NOx traps, particulate filters and catalytic converters). Vehicles wherein a fast light-off reformer is operated in accordance with the present invention may include automobiles, trucks, and other land vehicles, boats and ships, and aircraft including spacecraft.
[0035] While the invention has been described by reference to certain preferred embodiments, it should be understood that numerous changes may be made within the spirit and scope of the inventive concepts described. Accordingly, it is intended that the invention not be limited to the disclosed embodiments, but that it have the full scope permitted by the language of the following claims.
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A catalytic reformer assembly and methods of operation, including fast start-up, are provided. The reformer assembly includes an electrically-conductive metallic vaporizer having a very high surface area. At start-up of the reformer, electric current is passed through the vaporizer to heat the material by resistance heating, providing a high-temperature, high-surface area environment for fuel vaporization. Preferably, the electric current is started a few seconds before starting fuel flow. The fuel is sprayed either onto or through the heated vaporizer, preferably before the fuel is mixed with incoming air to minimize convective cooling by the air and to reduce the pressure drop in the fuel flow. As the reformer warms up, energy from the reforming process heats the vaporizer via radiation and/or conduction such that electric power is needed only during the start-up phase. A control circuit regulates the amount and duration of electric power supplied to the vaporizer.
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BACKGROUND OF THE INVENTION
[0001] The invention relates to electric motors, in particular electronically commutated electric motors, such as a claw-pole motor, for example.
[0002] Electric motors, in particular claw-pole motors, are known from the prior art. Claw-pole motors are used whenever low rotation speeds are required. For example, claw-pole motors are used for water pumps or the like.
[0003] Claw-pole motors have two (wound) stator coils running in a circumferential direction which surround a claw arrangement. The claw arrangement represents the stator of the electric motor and comprises stator teeth aligned in the axial direction, with which an alternating magnetic field can be produced. The claw arrangement is generally formed in two parts with subarrangements of magnetic material, with each of the subarrangements having a ring from which stator teeth protrude in the axial direction (i.e. perpendicular to the ring face). Furthermore, each of the subarrangements has on one side, at one end of the stator teeth, a section extending radially outwards.
[0004] The subarrangements are designed to be complementary with respect to one another, the outer ends, in a radial direction, of the subarrangements being connected to one another in the assembled state via a ring-shaped lamination in such a way that a magnetic return path is formed between the subarrangements. The claw arrangement forms a toroidal stator, with the stator coils being arranged in the interior of the torus. The claws of the subarrangements engage in one another in the assembled state in such a way that they do not touch one another and have equal distances with respect to one another. Depending on the energization of the stator coils, adjacent claws form a south pole and a north pole, or vice versa.
[0005] In general, an armature in the form of a rotor which is generally formed with permanent magnets or from a ferrite material is located in the region surrounded by the claw arrangement of the claw-pole motor. By alternately energizing the stator coils, the polarity of adjacent stator teeth is changed, as a result of which a force is exerted on the rotor and the rotor is driven.
[0006] Supplying such an electric motor with an alternating electrical variable results in electromagnetic interference (EMI). Such interference, in particular the emission of electromagnetic radiation by conductors and conducted interference can be brought about by electrical components in the electric motor and by metal component parts which are excited to produce EMI emission as a result of magnetic eddy currents. In general, the emission is reduced by further electrical component parts, such as capacitors and inductor coils, for example, being integrated in the drive circuit or in the electric motor. However, this is involved and increases the susceptibility of the entire system to faults.
[0007] Therefore, the object of the present invention is to provide an electronically commutated electric motor in which the EMI emission is reduced.
SUMMARY OF THE INVENTION
[0008] In accordance with a first aspect, a stator arrangement for an electronically commutated electric motor, in particular for a rotary claw-pole motor, is provided. The stator arrangement comprises:
[0009] an electrically conductive stator with a winding channel running in the circumferential direction;
[0010] a stator winding running in the winding channel;
[0011] one or more feed lines for making electrical contact with the stator winding; and
[0012] a contact element, which electrically connects one of the feed lines to the stator.
[0013] One concept of the present invention consists in reducing the EMI emission of an electronically commutated electric motor by virtue of connecting the electrically conductive stator, in particular the components with which the stator arrangement is constructed, to one of the feed lines which are used for driving the stator winding. This makes it possible to considerably reduce in particular eddy currents in the stator which are induced by the movement of a rotor.
[0014] Furthermore, the stator can have stator teeth extending in an axial direction of the electric motor.
[0015] In addition, the contact element can have a contact lamination, which is arranged under tension in order to exert a contact force on the stator and/or the feed line.
[0016] The contact element can have a conductor, which is riveted, adhesively bonded, soldered or welded to the stator and/or the feed line.
[0017] In accordance with a further aspect, an electric motor is provided with the above stator arrangement.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Embodiments will be explained in more detail below with reference to the attached drawings in which:
[0019] FIG. 1 shows a detail illustration of a claw-pole motor;
[0020] FIG. 2 shows an exploded illustration of the claw-pole motor shown in FIG. 1 ;
[0021] FIG. 3 shows a detail of the stator of the claw-pole motor shown in FIG. 1 ; and
[0022] FIG. 4 shows a contact-making element for producing an electrical connection between an electrical supply and the stator arrangement.
DETAILED DESCRIPTION
[0023] FIG. 1 shows a perspective illustration of a claw-pole motor 1 , which is arranged in a housing 2 . A control unit 3 is arranged on the housing 2 and is supplied with electrical power via a plug-type connection 4 . The control unit 3 generates an electrical drive variable for electrically driving the claw-pole motor 1 . For this purpose, feed lines 5 are provided between the control unit 3 and stator coils 6 of the claw-pole motor 1 .
[0024] The feed lines 5 represent connecting lines between the control unit 3 and stator coils 6 for transmitting the electrical drive variable. The connecting lines can be in the form of stamped sheet metal or the like, for example.
[0025] An annular or toroidal stator arrangement 7 , which is illustrated in more detail in the illustrations shown in FIGS. 2 and 3 , is located in the housing 2 . The stator arrangement 7 has a first claw element 8 and a second claw element 9 , which each have an annular section which defines mutually opposite lateral limits of the toroidal stator body in the axial direction.
[0026] The annular section of each of the claw elements 8 , 9 has claws 10 . Each of the claws 10 has an outwardly tapering form and is arranged in a segment of the annular section on a radially inner edge of the annular section. Each of the claws 10 extends in the axial direction. The claws 10 form the stator teeth. The claws 10 are arranged on the two claw elements 8 , 9 in such a way that they engage in one another in the assembled state of the claw elements 8 , 9 without coming into contact with one another. As a result, an air gap 12 remains between adjacent claws, i.e. claws 10 which are adjacent to one another in the circumferential direction are not in direct contact with one another.
[0027] In order to ensure a magnetic return path, the claw elements 8 , 9 are preferably connected to one another at their radially outer edge via a cylindrical magnetic return path ring 11 . Therefore, a channel for the two stator coils 6 is formed between the claws 10 , the annular sections of the claw elements 8 , 9 and the magnetic return path ring 11 .
[0028] The stator coils 6 are wound in the circumferential direction in this channel and therefore surround a rotor (not shown) concentrically, it being possible for said rotor to be arranged in the interior of the stator 7 . The two stator coils 6 are each energized alternately only in one direction, the current directions in the stator coils 6 being in opposition to one another. In other words, the control unit 3 drives the stator coils 6 periodically in such a way that a first of the stator coils 6 is energized with a drive variable during a first time period, such that a magnetic field is formed between adjacent claws 10 . During a second time period, a second of the stator coils 6 is energized with a drive variable, with a current flowing through the second stator coil 6 in an opposite direction with respect to the circumferential direction of the stator arrangement 7 . Depending on the choice of stator coil 6 energized at that time, a magnetic field with a specific direction is formed in the vicinity of the air gap 12 between the claws 10 , said magnetic field interacting with the rotor such that said rotor is driven. For this purpose, the rotor can have permanent magnets or can be manufactured from a ferrite material, in particular from a plastoferrite material.
[0029] The claw elements 8 , 9 and the magnetic return path ring 11 are formed from a metal material, preferably from metal sheets, and are therefore conductive. Owing to the magnetic field produced by the stator coils 6 , eddy currents can form in the metal sheets, which can result in EMI emission of the stator. For this reason, provision is made for the stator arrangement 7 surrounding the stator coils 6 to be electrically connected to one of the feed lines 5 . For this purpose, an electrically conductive contact element 13 is provided, which electrically connects the feed line 5 to the stator arrangement 7 .
[0030] In accordance with one embodiment, the contact element 13 , as illustrated in FIG. 4 , can be in the form of an electrically conductive contact lamination. The contact lamination can have a first limb 14 , which can be arranged between an inner wall of the housing 2 and the stator arrangement 7 held therein, in particular the magnetic return path ring 11 of the stator arrangement 7 . The first limb element 14 can have a deformation 15 , for example, which is arranged, under tension, between the inner wall of the housing 2 and the magnetic return path ring 11 in the installed state. As a result, an elastic force acts between the housing 2 and the magnetic return path ring 11 , as a result of which contact is made with the stator arrangement 7 electrically via the contact element 13 .
[0031] In particular, the deformed section 15 can be in the form of a V, with the first limb section 14 being arranged under tension in such a way that the apex of the V-shaped section 15 presses against the magnetic return path ring 11 in order to make electrical contact therewith. Alternatively, the apex of the V-shaped section 15 can also press against the housing 2 .
[0032] The housing 2 is preferably nonconductive, with the result that the external environment of the claw-pole motor can be insulated from the drive variables.
[0033] The contact element 13 also has a second limb section 16 , which presses elastically onto one of the feed lines 5 in the installed state. For this purpose, the feed line 5 in question is arranged at one end of the stator arrangement 7 in the axial direction, with the result that the limb sections 14 , 16 enclose an obtuse angle, a right angle or an acute angle. The contact element 13 is fixed via a holding section 17 , which is arranged between one of the annular sections of one of the claw elements 8 , 9 and a corresponding housing section which is opposite the corresponding annular section, in order to fix the contact element 13 reliably in the housing 2 and to ensure the contact-pressure force for the second limb section 16 .
[0034] The contact between one of the feed lines 5 and the stator arrangement 7 can furthermore be produced using a soldered or welded wire connection, via an electrically conducting film which is adhesively bonded to the corresponding feed line 5 and the stator arrangement 7 , via an electrically conducting varnish which is provided between the feed line 5 and the stator arrangement 7 or the like.
[0035] The contact element 13 can be connected to the stator arrangement 7 also via a suitable connection, such as by means of riveting, welding or soldering, for example.
[0036] The electrical connection between the stator arrangement and one of the feed lines 5 results in markedly reduced electromagnetic interference emission of the claw-pole motor, although an alternating electrical variable is applied to the stator arrangement 7 .
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The invention relates to a stator assembly ( 7 ) for an electric motor ( 1 ), in particular for a rotatory claw pole motor, comprising:—an electrically conductive stator ( 8, 9 ) having a winding channel extending in the circumferential direction;—a stator winding ( 6 ) extending in the winding channel;—feed lines ( 5 ) for electrically contacting the stator winding ( 6 );—a contact element ( 13 ), which electrically connects one of the feed lines ( 5 ) to the stator.
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This application is a continuation of U.S. application Ser. No. 13/748,355 filed Jan. 23, 2013, now U.S. Pat. No. 8,632,148, which is a Continuation of U.S. application Ser. No. 12/821,324, filed Jun. 23, 2010, now U.S. Pat. No. 8,382,224, which claims priority to Japanese Application No. 2009-151230, filed Jun. 25, 2009. The foregoing patent applications are incorporated herein by reference.
BACKGROUND
1. Technical Field
The present invention relates to a fluid ejection device in which a drive signal is applied to an actuator to eject fluid, and is suitable for a fluid ejection printer adapted to, for example, eject small droplets from a nozzle of a fluid ejection head to form fine particles (dots) on a print medium, thereby printing a predetermined character, image, or the like.
2. Related Art
In the fluid ejection printer, there is provided an actuator such as a piezoelectric element in order for ejecting a droplet from the nozzle of the fluid ejection head, and it is required to apply a predetermined drive signal on the actuator. Since the drive signal has a relatively high voltage, it is required to power-amplify a drive waveform signal forming a basis of the drive signal with a power amplifier circuit. Therefore, in JP-A-2007-168172 (Document 1), there is used a digital power amplifier circuit, which has a smaller power loss compared to an analog power amplifier circuit and can be made smaller in size, a modulator executes pulse modulation on the drive waveform signal to obtain a modulated signal, the digital power amplifier circuit performs power amplification on the modulated signal to obtain a power-amplified modulated signal, and a low pass filter smoothes the power amplified modulated signal to obtain the drive signal.
In the fluid ejection printer described in the Document 1 mentioned above, the digital power amplifier circuit continues to operate even in the case in which the voltage of the drive signal does not change. Since the piezoelectric element used as the actuator of the fluid ejection printer is a capacitive load, even in the case in which the current supply to the actuator is stopped, the voltage of the actuator is kept at the voltage applied immediately before the stoppage. In other words, since the drive signal applied to the actuator or the drive waveform signal forming a basis thereof has a portion (period) with a voltage kept constant, it is not necessary to supply the actuator with a current when the voltage of the drive signal does not change. However, in the fluid ejection printer described in the Document 1 mentioned above, there arises a problem that the digital power amplifier circuit continues to operate, and therefore, the power is consumed in the digital amplifier circuit and the low pass filter even when the voltage of the drive signal does not change.
SUMMARY
An advantage of some aspects of the invention is to provide a fluid ejection device capable of reducing power consumption and a fluid ejection printer using the fluid ejection device.
A fluid ejection device according to an aspect of the invention includes a modulator adapted to pulse-modulate a drive waveform signal forming a basis of a drive signal of an actuator to obtain a modulated signal, a digital power amplifier circuit adapted to power-amplify the modulated signal to obtain a power-amplified modulated signal, a low pass filter adapted to smooth the power-amplified modulated signal to obtain the drive signal, and a power amplification stopping section operating when holding a voltage of the actuator constant.
According to the fluid ejection device of this aspect of the invention, since the operation of the digital power amplifier circuit is stopped when keeping the voltage of the actuator constant, or in other words, keeping the voltage of the drive waveform signal constant, power consumption in the digital power amplifier circuit and in the low pass filter is reduced.
Further, the digital power amplifier circuit has a switching element, and the power amplification stopping section stops the operation of the digital power amplifier circuit by setting all of the switching elements of the digital power amplifier off.
According to the fluid ejection device of this aspect of the invention, since all of the switching elements of the digital power amplifier circuit are off, these switching elements become to be in the high-impedance state, thus the discharge from the actuator (a capacitive load) is prevented.
Further, the modulator stops an output of the modulated signal when the operation of the digital power amplifier circuit is stopped by the power amplification stopping section.
According to the fluid ejection device of this aspect of the invention, since the output of the modulated signal itself is stopped, the power consumption of the modulator and the digital power amplifier circuit is reduced.
Further, the modulator pulse-modulates the drive waveform signal using a first modulation frequency, and the modulator increases the modulation frequency of the pulse modulation from the first modulation frequency when a voltage applied to the drive waveform signal changes from varying to constant.
According to the fluid ejection device of this aspect of the invention, a ripple voltage that causes distortion in the drive waveform signal when stopping the operation of the digital power amplifier circuit is suppressed to enable a waveform of the drive signal to become closer to a desired form.
The modulator pulse-modulates the drive waveform signal using a first modulation frequency, and the modulator increases the modulation frequency of the pulse modulation from the first modulation frequency when a voltage applied to the drive waveform signal changes from constant to varying.
According to the fluid ejection device of this aspect of the invention, a ripple voltage that causes distortion of the drive waveform signal when resuming the operation of the digital power amplifier circuit is suppressed.
When, for the purpose of explaining, a period in which the modulated signal is in a high level is referred to as a first period, and a period in which the modulated signal is in a low level is referred to as a second period, the modulator sets the modulated signal to be at the high level (or the low level) for a half the time of the first period (or the second period) immediately after the voltage of the drive waveform signal changes from constant to varying.
According to the fluid ejection device of this aspect of the invention, a ripple voltage that causes distortion of the drive waveform signal when the voltage of the drive waveform signal changes from constant to varying is suppressed.
Further, the power amplification stopping section temporarily resumes the operation of the digital power amplifier circuit during a stoppage of the operation of the digital power amplifier circuit.
According to the fluid ejection device of this aspect of the invention, a voltage drop by self-discharge in the actuator due to being a capacitive load.
A memory adapted to store the drive waveform signal is further provided, and the memory stores drive waveform voltage difference data.
According to the fluid ejection device of this aspect of the invention, whether the voltage applied to the drive waveform signal is varying or not may be easily determined.
A memory adapted to store the drive waveform signal is further provided, and the memory stores drive waveform voltage data and information regarding whether the voltage of the drive waveform signal is varying or not.
According to the fluid ejection device of this aspect of the invention, determining whether the voltage applied to the drive waveform signal is varying or not is no longer required.
A memory adapted to store the drive waveform signal is further provided, and the memory stores drive waveform voltage data, and the power amplification stopping section calculates a difference between the drive waveform voltage data retrieved from the memory, and stops the operation of the digital power amplifier circuit when the difference indicates a 0.
According to the fluid ejection device of this aspect of the invention, the memory with small capacity can be adopted.
Further, the memory stores a modulation frequency by the modulator.
According to the fluid ejection device of this aspect of the invention, it becomes possible to flexibly set the modulation frequency.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described with reference to the accompanying drawings, wherein like numbers reference like elements.
FIG. 1 is a front view of a schematic configuration showing a fluid ejection printer using a fluid ejection device as an embodiment of the invention.
FIG. 2 is a plan view of the vicinity of fluid ejection heads used in the fluid ejection printer shown in FIG. 1 .
FIG. 3 is a block diagram of a control device of the fluid ejection printer shown in FIG. 1 .
FIG. 4 is an explanatory diagram of a drive signal for driving actuators in each of the fluid ejection heads.
FIG. 5 is a block diagram of a switching controller.
FIG. 6 is a block diagram of a drive circuit of the actuators.
FIGS. 7A and 7B are detailed block diagrams showing an example of the drive circuit shown in FIG. 6 .
FIG. 8 is an explanatory diagram of a modulated signal, a gate-source signal, and an output signal in the drive circuit shown in FIGS. 7A and 7B .
FIGS. 9A and 9B are detailed explanatory diagrams of the modulated signal shown in FIG. 8 .
FIG. 10 is a detailed explanatory diagram of the modulated signal shown in FIGS. 9A and 9B .
FIG. 11 is a waveform chart showing an example of a drive waveform signal.
FIG. 12 is an explanatory diagram of the memory contents showing a first embodiment of the invention.
FIG. 13 is a flow chart of arithmetic processing performed by the controller shown in FIG. 7A in accordance with the memory contents shown in FIG. 12 .
FIG. 14 is an explanatory diagram of the memory contents showing a second embodiment of the invention.
FIG. 15 is a flow chart of arithmetic processing performed by the controller shown in FIG. 7A in accordance with the memory contents shown in FIG. 14 .
FIG. 16 is an explanatory diagram of the memory contents showing a third embodiment of the invention.
FIG. 17 is a flow chart of arithmetic processing performed by the controller shown in FIG. 7A in accordance with the memory contents shown in FIG. 16 .
FIGS. 18A and 18B are detailed block diagrams showing another example of the drive circuit shown in FIG. 6 .
DESCRIPTION OF EXEMPLARY EMBODIMENTS
Then, as a first embodiment of the invention, a fluid ejection device applied to a fluid ejection printer will be explained.
FIG. 1 is a schematic configuration diagram of the fluid ejection printer according to the first embodiment, and in the drawing, the fluid ejection printer is a line head printer in which a print medium 1 is conveyed in the arrow direction from the left to the right of the drawing, and printed in a printing area midway of conveying.
The reference numeral 2 shown in FIG. 1 denotes a plurality of fluid ejection heads disposed above a conveying line of the print medium 1 , which are fixed individually to a head fixing plate 11 in such a manner as to form two lines in the print medium conveying direction and to be arranged in a direction intersecting with the print medium conveying direction. The fluid ejection head 2 is provided with a number of nozzles on the lowermost surface thereof, and the surface is called a nozzle surface. As shown in FIG. 2 , the nozzles are arranged to form lines in a direction intersecting with the print medium conveying direction color by color in accordance with the colors of the fluid to be ejected, and the lines are called nozzle lines, and the direction of the lines is called a nozzle line direction. Further, the nozzle lines of all of the fluid ejection heads 2 arranged in a direction intersecting with the print medium conveying direction constitute a line head covering the overall width of the print medium in a direction intersecting with the conveying direction of the print medium 1 . When the print medium 1 passes through under the nozzle surface of the fluid ejection head 2 , the fluid is ejected from a number of nozzles provided to the nozzle surface to thereby perform printing on the print medium 1 .
The fluid ejection head 2 is supplied with fluids such as ink of four colors of yellow (Y), magenta (M), cyan (C), and black (K) from fluid tanks not shown via fluid supply tubes. Then, a necessary amount of fluid is ejected simultaneously from the nozzles provided to the fluid ejection heads 2 to necessary positions, thereby forming fine dots on the print medium 1 . By executing the above for each of the colors, one-pass printing can be performed only by making the print medium 1 to be conveyed by a conveying section 4 pass through once.
As a method of ejecting a fluid from the nozzles of the fluid ejection head 2 , there can be cited an electrostatic driving method, a piezoelectric driving method, a film boiling fluid ejection method, and so on, and in the first embodiment there is used the piezoelectric driving method. In the piezoelectric driving method, when a drive signal is applied to a piezoelectric element as an actuator, a diaphragm in a cavity is displaced to cause pressure variation in the cavity, and the fluid is ejected from the nozzle due to the pressure variation. Further, by controlling the wave height and the voltage variation gradient of the drive signal, it becomes possible to control the ejection amount of the fluid. It should be noted that the invention can also be applied to fluid ejection methods other than the piezoelectric driving method in a similar manner.
Under the fluid ejection head 2 , there is disposed the conveying section 4 for conveying the print medium 1 in the conveying direction. The conveying section 4 is configured by winding a conveying belt 6 around a drive roller 8 and a driven roller 9 , and an electric motor not shown is coupled to the drive roller 8 . Further, in the inside of the conveying belt 6 , there is disposed an adsorption device, not shown, for adsorbing the print medium 1 on the surface of the conveying belt 6 . For the adsorption device there is used, for example, an air suction device for adsorbing the print medium 1 to the conveying belt 6 with negative pressure, or an electrostatic adsorption device for adsorbing the print medium 1 to the conveying belt 6 with electrostatic force. Therefore, when a feed roller 5 feeds just one sheet of the print medium 1 on the conveying belt 6 from a feeder section 3 , and then the electric motor rotationally drives the drive roller 8 , the conveying belt 6 is rotated in the print medium conveying direction, and the print medium 1 is conveyed while being adsorbed to the conveying belt 6 by the adsorption device. While conveying the print medium 1 , printing is performed by ejecting the fluid from the fluid ejection heads 2 . The print medium 1 on which printing has been performed is ejected to a catch tray 10 disposed on the downstream side in the conveying direction. It should be noted that a print reference signal output device formed of, for example, a linear encoder is attached to the conveying belt 6 . Focusing attention on the fact that the conveying belt 6 and the print medium 1 conveyed by the conveying belt 6 while being adsorbed by the conveying belt 6 are moved in sync with each other, the print reference signal output device outputs a pulse signal corresponding to the print resolution required in conjunction with the movement of the conveying belt 6 after the print medium 1 passes through a predetermined position on the conveying path, and a drive circuit described later outputs a drive signal to the actuator in accordance with this pulse signal to thereby eject the fluid of a predetermined color at a predetermined position on the print medium 1 , thus a predetermined image is drawn on the print medium 1 with the dots of the fluid.
Inside the fluid ejection printer using the fluid ejection device according to the first embodiment, there is provided a control device for controlling the fluid ejection printer. As shown in FIG. 3 , the control device is configured including an input interface 61 for reading print data input from a host computer 60 , a control section 62 configured with a microcomputer for executing arithmetic processing such as a printing process in accordance with the print data input from the input interface 61 , a feed roller motor driver 63 for controlling driving of a feed roller motor 17 coupled to the feed roller 5 , a head driver 65 for controlling driving of the fluid ejection heads 2 , and an electric motor driver 66 for controlling driving of an electric motor 7 coupled to the drive roller 8 , and further including an interface 67 for connecting the feed roller motor driver 63 , the head driver 65 , and the electric motor driver 66 , to the feed roller motor 17 , the fluid ejection heads 2 , and the electric motor 7 , respectively.
The control section 62 is provided with a central processing unit (CPU) 62 a , a random access memory (RAM) 62 c , and a read-only memory (ROM) 62 d . The CPU 62 a executes various processes such as a printing process. The random access memory (RAM) 62 c temporarily stores the print data input via the input interface 61 or data for executing, for example, the printing process of the print data, and temporarily develops a program of, for example, the printing process. The read-only memory (ROM) 62 d is formed of a nonvolatile semiconductor memory for storing the control program and so on executed by the CPU 62 a . The control section 62 obtains the print data (image data) from the host computer 60 via the input interface 61 . Then, the CPU 62 a executes a predetermined process on the print data to obtain nozzle selection data (drive pulse selection data) representing which nozzle the fluid is ejected from or how much fluid is ejected. Based on the print data, the drive pulse selection data, and input data from various sensors, drive signals and control signals are output to the feed roller motor driver 63 , the head driver 65 , and the electric motor driver 66 . In accordance with these drive signals and control signals, the feed roller motor 17 , the electric motor 7 , actuators 22 inside the fluid ejection head 2 , and so on operate individually, thus feeding, conveying, and ejection of the print medium 1 , and the printing process to the print medium 1 are executed. It should be noted that the constituents inside the control section 62 are electrically connected to each other via a bus not shown in the drawings.
FIG. 4 shows an example of a drive signal COM supplied from the control device of the fluid ejection printer using the fluid ejection device according to the first embodiment to the fluid ejection heads 2 , and for driving the actuators 22 each formed of a piezoelectric element. In the first embodiment, it is assumed that the signal has the electric potential varying around a midpoint potential. The drive signal COM is obtained by connecting drive pulses PCOM, each of which is a unit drive signal for driving the actuator 22 to eject the fluid, in a time-series manner. The rising portion of a drive pulse PCOM corresponds to a stage of expanding the volume of the cavity (a pressure chamber) communicating with the nozzle to pull-in (in other words, to pull-in the meniscus, in view of the ejection surface of the fluid) the fluid. The falling portion of the drive pulse PCOM corresponds to a stage of shrinking the volume of the cavity to push-out (in other words, to push-out the meniscus, in view of the ejection surface of the fluid) the fluid, and as a result of pushing out the fluid, the fluid is ejected from the nozzle.
By variously modifying the gradient of increase and decrease in voltage and the wave height of the drive pulse PCOM formed of trapezoidal voltage waves, the pull-in amount and the pull-in speed of the fluid, and the push-out amount and the push-out speed of the fluid can be modified, thus the ejection amount of the fluid can be varied to obtain the dots with different sizes. Therefore, even in the case in which a plurality of drive pulses PCOM are joined in a time-series manner, it is possible to select the single drive pulse PCOM from the drive pulses, and to supply the actuator 22 with the drive pulse PCOM to eject the fluid, or to select two or more drive pulses PCOM, and to supply them to the actuator 22 to eject the fluid two or more times, thereby obtaining the dots with various sizes. In other words, when the two or more droplets land on the same position before the droplets are dried, it brings substantially the same result as in the case of ejecting a larger amount of droplet, thus it is possible to increase the size of the dot. By a combination of such technologies, it becomes possible to achieve multiple tone printing. It should be noted that the drive pulse PCOM1 shown in the left end of FIG. 4 is only for pulling in the fluid without pushing it out. This is called a fine vibration, and is used for, for example, preventing thickening in the nozzle without ejecting the fluid.
Besides the drive signal COM described above, the drive pulse selection data SI&SP, a latch signal LAT, channel signal CH, and a clock signal SCK are input to the fluid ejection head 2 from the control device shown in FIG. 3 as the control signals. The drive pulse selection data SI&SP is used for selecting the nozzle ejecting the fluid based on the print data, and at the same time, determining the connection timing of the actuators 22 such as piezoelectric elements to the drive signal COM. The latch signal LAT and the channel signal CH connects the drive signal COM and the actuator 22 of the fluid ejection head 2 based on the drive pulse selection data SI&SP after the nozzle selection data is input to all of the nozzles. The clock signal SCK is used for transferring the drive pulse selection data SI&SP to the fluid ejection head 2 as a serial signal. It should be noted that it is hereinafter assumed that the minimum unit of the drive signal for driving the actuator 22 is the drive pulse PCOM, and the entire signal having the drive pulses PCOM joined with each other in a time-series manner is described as the drive signal COM. In other words, output of a string of drive signal COM is started in response to the latch signal LAT, and the drive pulse PCOM is output in response to each channel signal CH.
FIG. 5 shows a configuration of a switching controller, which is built inside the fluid ejection head 2 in order for supplying the actuator 22 with the drive signal COM (the drive pulses PCOM). The switching controller is provided with a shift register 211 , a latch circuit 212 , and a level shifter 213 . The shift register 211 stores the drive pulse selection data SI&SP for designating the actuators 22 such as piezoelectric elements corresponding to the nozzles for ejecting the fluid. The latch circuit 212 temporarily stores the data of the shift register 211 . The level shifter 213 performs level conversion on the output of the latch circuit 212 , and then supplies the result to a selection switch 201 , thereby connecting the drive signal COM to the actuators 22 such as piezoelectric elements.
The drive pulse selection data SI&SP is sequentially input to the shift register 211 , and at the same time, the storage area thereof is sequentially shifted from the first stage to the subsequent stage in accordance with the input pulse of the clock signal SCK. The latch circuit 212 latches the output signals of the shift register 211 in accordance with the latch signal LAT input thereto after the drive pulse selection data SI&SP corresponding to the number of nozzles has been stored in the shift register 211 . The signals stored in the latch circuit 212 are converted by the level shifter 213 so as to have the voltage levels capable of switching on and off the selection switches 201 on the subsequent stage. This is because the drive signal COM has a relatively high voltage compared to the output voltage of the latch circuit 212 , and the operating voltage range of the selection switches 201 is also set to be high in accordance therewith. Therefore, the actuator 22 such as a piezoelectric element, the selection switch 201 of which is closed by the level shifter 213 , is coupled to the drive signal COM (the drive pulses PCOM) (switched on) at the coupling timing of the drive pulse selection data SI&SP. Further, after the drive pulse selection data SI&SP of the shift register 211 is stored in the latch circuit 212 , the subsequent print information is input to the shift register 211 , and the stored data in the latch circuit 212 is sequentially updated in sync with the fluid ejection timing. It should be noted that the reference symbol HGND in the drawing denotes the ground terminal for the actuators 22 such as piezoelectric elements. Further, even after the actuator 22 such as a piezoelectric element is separated from the drive signal COM (the drive pulses PCOM) (switched off), the selection switch 201 maintains the input voltage of the actuator 22 at the voltage applied thereto immediately before the separation.
FIG. 6 shows a schematic configuration of the drive circuit for the actuators 22 . The actuator drive circuit is built inside the control section 62 and the head driver 65 included in the control circuit. The drive circuit of the first embodiment is configured including a drive waveform generator 25 , a modulator 26 , a digital power amplifier circuit 28 , and a low pass filter 29 . The drive waveform generation circuit 25 generates a basis of the drive signal COM (the drive pulses PCOM), namely a drive waveform signal WCOM forming a basis of the signal for controlling the drive of the actuator 22 . The modulator 26 performs pulse modulation on the drive waveform signal WCOM generated by the drive waveform generator 25 . The digital power amplifier circuit 28 power-amplifies the modulated signal pulse-modulated by the modulator 26 . The low pass filter 29 smoothes the power-amplified modulated signal power-amplified by the digital power amplifier circuit 28 , and then supplies the result to the fluid ejection heads 2 as the drive signal COM (the drive pulses PCOM). The drive signal COM (the drive pulses PCOM) is supplied from the selection switches 201 to the actuators 22 .
FIGS. 7A and 7B show a configuration of the actuator drive circuit. FIG. 7A shows the drive waveform generator 25 and the modulator 26 , and FIG. 7B shows the digital power amplifier circuit 28 , the low pass filter 29 , and the fluid ejection heads 2 . The drive waveform generator 25 is configured including a memory 31 , a controller 32 , and a D/A converter 33 . The memory 31 stores drive waveform data of the drive waveform signal formed of digital voltage data or the like. The controller 32 converts the drive waveform data read from the memory 31 into a voltage signal, and then holds the result corresponding to a predetermined sampling period, and at the same time, instructs a triangular wave oscillator described later in a frequency and a waveform of a triangular wave signal, or a waveform output timing. The D/A converter 33 performs analog conversion on the voltage signal output from the controller 32 , and outputs the result as the drive waveform signal WCOM. It should be noted that the controller 32 also outputs an operation stop signal /Disable for stopping the operation of the digital power amplifier circuit 28 to a gate drive circuit 30 described later in the digital power amplifier circuit 28 . It is assumed that the operation of the digital power amplifier circuit 28 is stopped when the operation stop signal /Disable takes a low level.
Further, as the modulator 26 , there is used a known pulse width modulator (PWM). The modulator 26 is provided with the triangular wave oscillator 34 for outputting the triangular wave signal forming a base signal in accordance with the frequency, the waveform, and the waveform output timing instructed from the controller 32 described above. A comparator 35 compares the drive waveform signal WCOM output from the D/A converter 33 with the triangular wave signal output from the triangular wave oscillator 34 , and then outputs the modulated signal with a pulse duty cycle in which the on-duty represents that the drive waveform signal WCOM is higher than the triangular wave signal. It should be noted that the frequency of the triangular wave signal (the base signal) is defined as a modulation frequency (called, in general, a carrier frequency, for example). Further, as the modulator 26 , there can be used a well-known pulse modulator such as a pulse density modulator (PDM) besides the above.
The digital power amplifier circuit 28 is configured including a half-bridge output stage 21 and the gate drive circuit 30 . The half-bridge output stage 21 is composed of a high-side switching element Q1 and a low-side switching element Q2 for substantially amplifying the power. The gate drive circuit 30 controls the gate-source signals GH, GL of the high-side switching element Q1 and the low-side switching element Q2 based on the modulated signal from the modulator 26 . In the digital power amplifier circuit 28 , when the modulated signal is in the high level, the gate-source signal GH of the high-side switching element Q1 becomes in the high level, while the gate-source signal GL of the low-side switching element Q2 becomes in the low level. In other words, since the high-side switching element Q1 is set to be in a connected state (“ON”) and the low-side switching element Q2 is set to be in an unconnected state (“OFF”), as a result, the output Va of the half-bridge output stage 21 becomes equal to a supply voltage VDD. On the other hand, when the modulated signal is in the low level, the gate-source signal GH of the high-side switching element Q1 becomes in the low level, while the gate-source signal GL of the low-side switching element Q2 becomes in the high level. In other words, since the high-side switching element Q1 is OFF and the low-side switching element Q2 is ON, as a result, the output Va of the half-bridge output stage 21 becomes 0.
In the case in which the high-side switching element Q1 and low-side switching element Q2 are driven digitally as described above, although a current flows through the switching element that is ON, the resistance value between the drain and the source is small, and therefore, the loss is hardly caused. Further, since no current flows in the switching element that is OFF, no loss is caused. Therefore, the loss itself of the digital power amplifier circuit 28 is extremely small, and therefore, it is possible to use small-sized switching elements such as MOSFETs.
It should be noted that when the operation stop signal /Disable output from the controller 32 is in the low level, the gate drive circuit 30 sets both of the high-side switching element Q1 and the low-side switching element Q2 OFF. As described above, when the digital power amplifier circuit 28 is in operation, either one of the high-side switching element Q1 and the low-side switching element Q2 is ON. Setting both of the high-side switching element Q1 and the low-side switching element Q2 OFF is equivalent to stopping the operation of the digital power amplifier circuit 28 , which leads that the actuators 22 each formed of a piezoelectric element, the capacitive load from an electrical point of view, are kept in a high-impedance state. If the actuators 22 are kept in the high-impedance state, the charge stored in the actuators 22 as capacitive loads is held, and the charge/discharge state is maintained or restricted to a slight self-discharge state.
As the low pass filter 29 , there is used a quadratic filter composed of one capacitor C and a coil L. The modulation frequency generated by the modulator 26 , namely the frequency component of the pulse modulation, is attenuated to be removed by the low pass filter 29 , and then the drive signal COM (the drive pulses PCOM) having the waveform characteristic described above is output. It should be noted that although FIGS. 7A and 7B show a form of a circuit for the sake of easiness of understanding, the drive waveform generator 25 and the modulator 26 can also be constituted by a program executed inside the control section 62 shown in FIG. 3 . The low pass filter 29 can be configured using a stray inductance or a stray capacitance generated in the circuit wiring, the actuator, or the like, and is therefore not necessarily required to be formed as a circuit. Further, the memory 31 can also be formed inside the ROM 62 d.
FIG. 8 shows a control condition of the digital power amplification performed in the first embodiment. The upper part of FIG. 8 shows the condition of ordinary digital power amplification as a related art example, while the lower part of FIG. 8 shows a specific example of the digital power amplification control of the first embodiment. In the ordinary digital power amplification having been performed from the past, the digital power amplifier circuit is made to continue to operate constantly irrespective of whether or not the voltage of the drive signal COM varies. For example, since the digital power amplifier circuit used in the field of the audio engineering is premised on the fact that the input is varied constantly, there is no chance to stop the operation. On the other hand, since the actuator 22 such as a piezoelectric element is a capacitive load, there is no need to apply electrical current when the voltage of the drive signal COM does not vary. Despite the circumstance described above, if the high-side switching element Q1 and the low-side switching element Q2 of the digital power amplifier circuit 28 continues to be switched on/off, the power is consumed in the high-side switching element Q1, the low-side switching element Q2, and the coil L of the low pass filter 29 .
Therefore, in the first embodiment, as shown in the truth table of Table 1 described below, when the voltage of the drive signal COM (the same can be applied to the drive waveform signal WCOM, which has not yet been power-amplified) does not vary, the operation stop signal /Disable is set to be in the low level to stop the operation of the digital power amplifier circuit 28 , and further both of the high-side switching element Q1 and the low-side switching element Q2 are OFF. When setting both of the high-side switching element Q1 and the low-side switching element Q2 OFF, the actuators 22 as the capacitive loads are kept in the high-impedance state, and hence there is little of the self-discharge. Further, in the first embodiment, in the case of stopping the operation of the digital power amplifier circuit 28 , namely when the voltage of the drive signal COM (the drive waveform signal WCOM) does not vary, output of the modulated signal PWM is also stopped (kept in the low level). Thus, the power consumption in the modulator 26 and the gate drive circuit 30 can also be reduced.
TABLE 1
Pulse Modulation
Signal
/Disable
Q1
Q2
Power Amplifier
0
1
OFF
ON
Operating
1
ON
OFF
0
0
OFF
Stopped
1
Incidentally, it is not possible to set both of the high-side switching element Q1 and the low-side switching element Q2 of the digital power amplifier circuit 28 OFF only by stopping the output of the modulated signal PWM (keeping the modulated signal PWM in the low level). This is because, when the modulated signal PWM is in the low level, the gate-source signal GH of the high-side switching element Q1 becomes in the low level, but the gate-source signal GL of the low-side switching element Q2 becomes in the high level, and consequently, the high-side switching element Q1 becomes OFF, but the low-side switching element Q2 becomes ON. Therefore, the gate drive circuit 30 sets both of the gate-source signal GH of the high-side switching element Q1 and the gate-source signal GL of the low-side switching element Q2 to be in the low level when the operation stop signal /Disable is in the low level, thereby setting both of the high-side switching element Q1 and the low-side switching element Q2 OFF.
FIGS. 9A and 9B show the details of the PWM modulation performed in the modulator 26 . FIG. 9A shows the state in which the voltage of the drive waveform signal WCOM gradually increases, and is then held constant, and then decreases gradually. Further, FIG. 9B shows the state in which the voltage of the drive waveform signal WCOM gradually decreases, and is then held constant, and then increases gradually. In the first embodiment, in both of the case in which the drive waveform signal WCOM increases and the case in which the drive waveform signal WCOM decreases, the modulation frequency (the frequency of the triangular wave signal TRI) of the pulse modulation is increased when the voltage of the drive waveform signal WCOM changes from varying to constant. Similarly, in both of the case in which the drive waveform signal WCOM increases and the case in which the drive waveform signal WCOM decreases, the modulation frequency (the frequency of the triangular wave signal TRI) of the pulse modulation is also increased when the voltage of the drive waveform signal WCOM changes from constant to varying. Specifically, the modulation frequency (the frequency of the triangular wave signal TRI) of the usual pulse modulation is set to be 500 kHz, and the modulation frequency (the frequency of the triangular wave signal TRI) of the pulse modulation when the voltage of the drive waveform signal WCOM changes from varying to constant or from constant to varying is set to be 1,000 kHz. According to the configuration described above, the ripple voltage of the drive signal COM in each of the transition periods can be prevented, and it becomes possible to match the voltage of the drive signal with no particular variation with the target value. It should be noted that the switching of the modulation frequency is not limited to two levels, it is also possible to increase the number of levels of the switching, or to vary the modulation frequency gradually.
Further, in the first embodiment, the period with the modulated signal PWM in either of the high level and the low level immediately after the voltage of the drive waveform signal WCOM changes from constant to varying is set to be a half of the period of the original modulated signal PWM. Specifically, since it is arranged that the modulated signal PWM becomes in the high level when the drive waveform signal WCOM is higher than the triangular wave signal TRI, and the modulated signal PWM becomes in the low level when the drive waveform signal WCOM is lower than the triangular wave signal TRI as shown in FIG. 10 , by arranging that the output of the modulated signal PWM is started from the lower apexes of the triangular wave signal TRI, the period with the high level halves. Further, by arranging that the output of the modulated signal PWM is started from the upper apexes of the triangular wave signal TRI, the period with the low level halves. For example, in FIG. 9A , the controller 32 instructs the triangular wave oscillator 34 in the wave form and the waveform output timing of the triangular wave signal TRI so that the triangular wave signal TRI is started from the upper apex simultaneously with when the voltage of the drive waveform signal WCOM starts to decrease from a constant state. In contrast, in FIG. 9B , the controller 32 instructs the triangular wave oscillator 34 in the wave form and the waveform output timing of the triangular wave signal TRI so that the triangular wave signal TRI is started from the lower apex simultaneously with when the voltage of the drive waveform signal WCOM starts to increase from a constant state. Further, according to the process described above, the ripple voltage of the drive signal COM in each of the transition periods can be prevented.
Further, in the first embodiment, in the period in which the digital power amplifier circuit 28 stops the operation thereof, the operation of the digital power amplifier circuit is temporarily resumed. Specifically, the operation stop signal /Disable is set to be in the high level to resume the operation of the gate drive circuit 30 , and at the same time, the modulated signal PWM is output from the modulator 26 to perform on/off control of the high-side switching element Q1 and the low-side switching element Q2 of the digital power amplifier circuit 28 . Since the operation of the digital power amplifier circuit 28 is stopped when the voltage of the drive waveform signal WCOM does not vary, the voltage of the drive signal COM supplied to the actuators 22 is also the same as the voltage before and after the operation of the digital power amplifier circuit 28 is stopped. According to the process described above, it becomes possible to prevent the voltage drop due to the self-discharge of the actuators 22 made of capacitive loads.
For example, in the case in which the drive waveform signal WCOM takes the voltage of 0V in the periods 0 through 2, the voltage of 2V in the period 3, the voltage of 4V in the period 4, the voltage of 6V in the period 5, the voltage of 8V in the period 6, the voltage of 10V in the periods 7 through 11, the voltage of 8V in the period 12, the voltage of 6V in the period 13, the voltage of 4V in the period 14, the voltage of 2V in the period 15, and the voltage of 0V in the periods 16 through 18 as shown in FIG. 11 , the memory 31 stores the data shown in FIG. 12 , for example. In the first embodiment, the voltage difference between the adjacent periods is stored as an output voltage difference value Vd, and at the same time, the modulation frequency (the PWM frequency in the drawing) fpwm in each of the periods is also stored.
FIG. 13 is a flowchart of an arithmetic processing performed in the controller 32 using the data stored in the memory 31 shown in FIG. 12 . In the arithmetic processing, firstly, a previous voltage value Vs is cleared in the step S 1 .
Then, the process proceeds to the step S 2 , and a memory address counter N is cleared.
Subsequently, the process proceeds to the step S 3 , and the waveform data (the output voltage difference value) Vd is retrieved from the memory 31 .
Then, the process proceeds to the step S 4 , and whether or not the waveform data (the output voltage difference value) Vd retrieved in the step S 3 is the waveform termination data is determined. If it is the waveform termination data, the arithmetic processing is terminated, and otherwise the process proceeds to the step S 5 .
In the step S 5 , determination of the waveform data (the output voltage difference value) Vd retrieved in the step S 3 is performed. In this case, if the previous output voltage difference value Vd is 0, and the output voltage difference value Vd retrieved presently is also 0, the process proceeds to the step S 6 on the ground that the voltage of the drive waveform signal WCOM is constant. Further, if the previous output voltage difference value Vd is not 0, and the output voltage difference value Vd retrieved presently is 0, the process proceeds to the step S 11 on the ground that the voltage of the drive waveform signal WCOM changes to constant. If the previous output voltage difference value Vd is 0, and the output voltage difference value Vd retrieved presently takes a positive value, the process proceeds to the step S 13 on the ground that the voltage of the drive waveform signal WCOM does not vary to the state of increasing the voltage occurs. Further, if the previous output voltage difference value Vd is 0, and the output voltage difference value Vd retrieved presently takes a negative value, the process proceeds to the step S 14 on the ground that the voltage of the drive waveform signal WCOM changes from varying to constant. In other cases such as the case in which the previously-output voltage difference value Vd is not 0, and the output voltage difference value Vd last retrieved is not 0, the process proceeds to the step S 15 .
In the step S 6 , determination of the modulation frequency fpwm retrieved from the memory 31 is performed. In this case, if the previous modulation frequency fpwm is 0, and the modulation frequency fpwm retrieved presently is not 0, the process proceeds to the step S 7 on the ground that the operation of the digital power amplifier circuit 28 is to be resumed temporarily. Further, if the previous modulation frequency fpwm is not 0, and the modulation frequency fpwm retrieved presently is 0, the process proceeds to the step S 8 on the ground that the operation of the digital power amplifier circuit 28 is to be stopped. Further, if the previous modulation frequency fpwm is 0, and the modulation frequency fpwm retrieved presently is also 0, the process proceeds to the step S 10 on the ground that the operation of the digital power amplifier circuit 28 continues to be stopped.
In the step S 7 , the on-duty period of the modulated signal PWM is reduced to half, and is then output, and the process proceeds to the step S 9 .
In the step S 9 , the operation stop signal /Disable is set to be in the high level to make the digital power amplifier circuit 28 and the modulator 26 operate, and the process proceeds to the step S 12 .
Further, in the step S 8 , the process waits until the end of the modulation period, and then proceeds to the step S 10 .
Further, also in the step S 11 , the process waits until the end of the modulation period, and then proceeds to the step S 10 .
In the step S 10 , the operation stop signal /Disable is set to be in the low level, and the operations of the digital power amplifier circuit 28 and the modulator 26 are stopped, and the process proceeds to the step S 12 .
Incidentally, in the step S 13 , by controlling the waveform and the waveform output timing of the triangular wave signal TRI as described above, the period in which the modulated signal PWM is kept in the high level is reduced to half of the period in which the original modulated signal is kept in the high level, and is then output, and the process proceeds to the step S 15 .
Further, in the step S 14 , by controlling the waveform and the waveform output timing of the triangular wave signal TRI as described above, the period in which the modulated signal PWM is kept in the low level is reduced to half of the period in which the original modulated signal is kept in the low level, and is then output, and the process proceeds to the step S 15 .
In the step S 15 , the output voltage difference value Vd is added to the previous voltage value Vs to thereby obtain a present voltage value V, and the process proceeds to the step S 16 .
In the step S 16 , the present voltage value V obtained in the step S 15 is output to the D/A converter 33 , and the process proceeds to the step S 17 .
In the step S 17 , the modulation frequency fpwm retrieved from the memory 31 is output to the modulator 26 (the triangular wave oscillator 34 ), and the process proceeds to the step S 18 .
In the step S 18 , the operation stop signal /Disable is set to be in the high level, and at the same time, the digital power amplifier circuit 28 and the modulator 26 are made to operate, and the process proceeds to the step S 19 .
In the step S 19 , the present voltage value V is stored as an update of the previous voltage value Vs, and then the process proceeds to the step S 12 .
In the step S 12 , the process waits until the read timing of the memory 31 , and then proceeds to the step S 20 .
In the step S 20 , the memory address counter N is incremented, and then the process proceeds to the step S 3 .
According to this arithmetic processing, the operation of the digital power amplifier circuit 28 is stopped when the voltage of the drive signal COM does not vary, and consequently, there is no need to supply the actuators 22 with the current, namely when the voltage of the drive waveform signal WCOM does not vary, thereby making it possible to reduce an amount of power consumption in the high-side switching element Q1 and the low-side switching element Q2 constituting the digital power amplifier circuit 28 , and the coil L inside the low pass filter 29 .
Further, by setting both of the high-side switching element Q1 and the low-side switching element Q2 of the digital power amplifier circuit 28 OFF, it becomes possible to set the high-side switching element Q1 and the low-side switching element Q2 to be in the high-impedance state, thus it becomes possible to prevent the discharge from the actuators 22 as capacitive loads.
Further, by stopping the output of the modulated signal PWM itself in the case in which the operation of the digital power amplifier circuit 28 is stopped, the power consumption in the modulator 26 and the gate drive circuit 30 of the digital power amplifier circuit 28 can be reduced.
When the voltage of the drive waveform signal WCOM changes from varying to constant, the ripple voltage caused when stopping the operation of the digital power amplifier circuit 28 is preventable by increasing the modulation frequency fpwm of the pulse modulation, so as to match the voltage of the drive signal COM having no variation with the target value.
When the voltage of the drive waveform signal WCOM changes from constant to varying, the ripple voltage caused when resuming the operation of the digital power amplifier circuit 28 is preventable by increasing the modulation frequency fpwm of the pulse modulation.
Further, the period in which the modulated signal PWM is in the high level, immediately after the voltage of the drive waveform signal WCOM has changed from constant to increasing, is set to be a half of the period in which the original modulated signal PWM is in the high level, thus the ripple voltage can be prevented.
Further, the period in which the modulated signal PWM is in the low level, immediately after the voltage of the drive waveform signal WCOM has changed from constant to decreasing, is set to be a half of the period in which the original modulated signal PWM is in the low level, thus the ripple voltage can be prevented.
Further, by temporarily resuming the operation of the digital power amplifier circuit 28 while stopping the operation of the digital power amplifier circuit 28 , it becomes possible to prevent the voltage drop due to the self-discharge of the actuators 22 formed of capacitive loads.
Further, since the drive waveform signal WCOM is stored in the memory 31 as the data of the output voltage difference value Vd, it becomes easy to determine whether or not the voltage of the drive waveform signal WCOM varies.
Further, since the modulation frequency fpwm by the modulator 26 is also stored in the memory 31 , it becomes possible to flexibly set the modulation frequency fpwm.
Then, a fluid ejection device according to a second embodiment of the invention will be explained. The fluid ejection device according to the present embodiment is applied to the fluid ejection printer similarly to the first embodiment described above, and the schematic configuration, the vicinity of the fluid ejection head, the control device, the drive signal, the switching controller, the actuator drive circuit, the modulated signal, the gate-source signals, and the output signal are substantially the same as those of the first embodiment described above. The second embodiment is different therefrom in the contents of the data stored in the memory 31 , and the arithmetic processing performed by the controller 32 using the stored data.
For example, assuming that the waveform of the drive waveform signal is substantially the same as shown in FIG. 11 of the first embodiment, the data having the contents shown in FIG. 14 is stored in the memory 31 in the second embodiment. In the second embodiment, the output voltage value (drive waveform voltage data) V of the drive waveform signal WCOM in each of the periods, drive waveform states D0, D2 in each of the periods, and the modulation frequency (PWM frequency in FIG. 14 ) fpwm in each of the periods are stored in the memory 31 . The drive waveform states D0, D2 are expressed with 3 bit data, wherein [000] represents that the voltage of the drive waveform signal WCOM is constant, [011] represents the voltage of the drive waveform signal WCOM changes from constant to increasing, [111] represents that the voltage of the drive waveform signal WCOM continues to vary, [010] represents a change in the voltage of the drive waveform signal WCOM from varying to constant, [101] represents that the operation of the digital power amplifier circuit 28 is temporarily resumed, [100] represents that the operation of the digital power amplifier circuit 28 is stopped, and [001] represents that that the voltage of the drive waveform signal WCOM changes from constant to decreasing.
FIG. 15 is a flowchart of an arithmetic processing performed in the controller 32 using the data stored in the memory 31 shown in FIG. 14 . In the arithmetic processing, firstly, the previous voltage value Vs is cleared in the step S 101 .
Then, the process proceeds to the step S 102 , and the memory address counter N is cleared.
Subsequently, the process proceeds to the step S 103 , and the waveform data (the output voltage value) V is retrieved from the memory 31 .
Then, the process proceeds to the step S 104 to determine whether or not the waveform data (the output voltage value) V retrieved in the step S 103 is the waveform termination data, and if it is the waveform termination data, the arithmetic processing is terminated, and otherwise the process proceeds to the step S 105 .
In the step S 105 , determination of the waveform states D0, D2 retrieved in the step S 103 is performed. In this case, if the drive waveform states D0, D2 are [101], the process proceeds to the step S 107 on the ground that the operation of the digital power amplifier circuit 28 is to be resumed temporarily. Further, if the drive waveform states D0, D2 are [100], the process proceeds to the step S 108 on the ground that the operation of the digital power amplifier circuit 28 is to be stopped. Further, if the drive waveform states D0, D2 are [000], the process proceeds to the step S 110 on the ground that the operation of the digital power amplifier circuit 28 continues to be stopped. If the drive waveform states D0, D2 are [010], the process proceeds to the step S 111 on the ground that a change in the voltage of the drive waveform signal WCOM from varying to constant occurs. If the drive waveform states D0, D2 are [011], the process proceeds to the step S 113 on the ground that a change in the voltage of the drive waveform signal WCOM changes from constant to increasing occurs. If the drive waveform states D0, D2 are [001], the process proceeds to the step S 114 on the ground that a change in the voltage of the drive waveform signal WCOM from constant to decreasing occurs. Further, if the drive waveform states D0, D2 are [11*] (* represents either one of 0 and 1), the process proceeds to the step S 116 as other states.
In the step S 107 , the on-duty period of the modulated signal PWM is reduced to half, and is then output, and the process proceeds to the step S 109 .
In the step S 109 , the operation stop signal /Disable is set to be in the high level to make the digital power amplifier circuit 28 and the modulator 26 operate, and the process proceeds to the step S 112 .
Further, in the step S 108 , the process waits until the end of the modulation period, and then proceeds to the step S 110 .
Further, also in the step S 111 , the process waits until the end of the modulation period, and then proceeds to the step S 110 .
In the step S 110 , the operation stop signal /Disable is set to be in the low level, and the operations of the digital power amplifier circuit 28 and the modulator 26 are stopped, and the process proceeds to the step S 112 .
Incidentally, in the step S 113 , by controlling the waveform and the waveform output timing of the triangular wave signal TRI as described above, the period in which the modulated signal PWM is kept in the high level is reduced to half of the period in which the original modulated signal is kept in the high level, and is then output, and the process proceeds to the step S 116 .
Further, in the step S 114 , by controlling the waveform and the waveform output timing of the triangular wave signal TRI as described above, the period in which the modulated signal PWM is kept in the low level is reduced to half of the period in which the original modulated signal is kept in the low level, and is then output, and the process proceeds to the step S 116 .
In the step S 116 , the output voltage value V retrieved in the step S 103 is output to the D/A converter 33 , and the process proceeds to the step S 117 .
In the step S 117 , the modulation frequency fpwm retrieved from the memory 31 is output to the modulator 26 (the triangular wave oscillator 34 ), and the process proceeds to the step S 118 .
In the step S 118 , the operation stop signal /Disable is set to be in the high level, and at the same time, the digital power amplifier circuit 28 and the modulator 26 are made to operate, and the process proceeds to the step S 112 .
In the step S 112 , the process waits until the read timing of the memory 31 , and then proceeds to the step S 120 .
In the step S 120 , the memory address counter N is incremented, and then the process proceeds to the step S 103 .
According to this arithmetic processing, since the drive waveform signal WCOM is stored in the memory 31 as the output voltage value (the drive waveform voltage data) V, and the memory 31 also stores the drive waveform states (information regarding whether or not the voltage of the drive waveform signal varies) D0, D2, it becomes possible to eliminate the determination itself on whether or not the voltage of the drive waveform signal WCOM varies in addition to the advantage of the first embodiment described above.
Then, a fluid ejection device according to a third embodiment of the invention will be explained. The fluid ejection device according to the third embodiment is applied to the fluid ejection printer similarly to the first embodiment described above, and the schematic configuration, the vicinity of the fluid ejection head, the control device, the drive signal, the switching controller, the actuator drive circuit, the modulated signal, the gate-source signals, and the output signal are substantially the same as those of the first embodiment described above. The third embodiment is different therefrom in the contents of the data stored in the memory 31 , and the arithmetic processing performed by the controller 32 using the stored data. For example, assuming that the waveform of the drive waveform signal is substantially the same as shown in FIG. 11 of the first embodiment, the data having the contents shown in FIG. 16 is stored in the memory 31 in the third embodiment. In the third embodiment, the output voltage value (drive waveform voltage data) V of the drive waveform signal WCOM in each of the periods, and the modulation frequency (PWM frequency in FIG. 16 ) fpwm in each of the periods are stored in the memory 31 .
FIG. 17 is a flowchart of an arithmetic processing performed in the controller 32 using the data stored in the memory 31 shown in FIG. 16 . In the arithmetic processing, firstly, the previous voltage value Vs is cleared in the step S 201 .
Then, the process proceeds to the step S 202 , and the memory address counter N is cleared.
Subsequently, the process proceeds to the step S 203 , and the waveform data (the output voltage value) V is retrieved from the memory 31 .
Then, the process proceeds to the step S 204 to determine whether or not the waveform data (the output voltage value) V retrieved in the step S 203 is the waveform termination data, and if it is the waveform termination data, the arithmetic processing is terminated, and otherwise the process proceeds to the step S 205 .
In the step S 205 , determination of the waveform data (the output voltage value) V retrieved in the step S 203 is performed. In this case, if the value obtained by subtracting the last-but-one output voltage value V from the last output voltage value V is 0, and the value obtained by subtracting the last output voltage value V from the output voltage value V retrieved presently is also 0, the process proceeds to the step S 206 on the ground that the voltage of the drive waveform signal WCOM stays constant. If the value obtained by subtracting the last-but-one output voltage value V from the last output voltage value V is not 0, and the value obtained by subtracting the last output voltage value V from the output voltage value V retrieved presently is 0, the process proceeds to the step S 211 on the ground that the drive waveform signal WCOM has become constant. If the value obtained by subtracting the last-but-one output voltage value V from the last output voltage value V is 0, and the value obtained by subtracting the last output voltage value V from the output voltage value V retrieved presently is a positive value, the process proceeds to the step S 213 on the ground that a change in the voltage of the drive waveform signal WCOM from constant to increasing occurs. Further, if the value obtained by subtracting the last-but-one output voltage value V from the last output voltage value V is 0, and the value obtained by subtracting the last output voltage value V from the output voltage value V retrieved presently is a negative value, the process proceeds to the step S 214 on the ground that there a change in the voltage of the drive waveform signal WCOM from constant to decreasing. Otherwise the process proceeds to the step S 216 .
In the step S 206 , determination of the modulation frequency fpwm retrieved from the memory 31 is performed. In this case, if the previous modulation frequency fpwm is 0, and the modulation frequency fpwm retrieved presently is not 0, the process proceeds to the step S 207 on the ground that the operation of the digital power amplifier circuit 28 is to be resumed temporarily. Further, if the previous modulation frequency fpwm is not 0, and the modulation frequency fpwm retrieved presently is 0, the process proceeds to the step S 208 on the ground that the operation of the digital power amplifier circuit 28 is to be stopped. Further, if the previous modulation frequency fpwm is 0, and the modulation frequency fpwm retrieved presently is also 0, the process proceeds to the step S 210 on the ground that the operation of the digital power amplifier circuit 28 continues to be stopped.
In the step S 207 , the on-duty period of the modulation signal PWM is reduced to half, and is then output, and the process proceeds to the step S 209 .
In the step S 209 , the operation stop signal /Disable is set to be in the high level to make the digital power amplifier circuit 28 and the modulator 26 operate, and the process proceeds to the step S 212 .
Further, in the step S 208 , the process waits until the end of the modulation period, and then proceeds to the step S 210 .
Further, also in the step S 211 , the process waits until the end of the modulation period, and then proceeds to the step S 210 .
In the step S 210 , the operation stop signal /Disable is set to be in the low level, and at the same time, the operations of the digital power amplifier circuit 28 and the modulator 26 are stopped, and the process proceeds to the step S 212 .
Incidentally, in the step S 213 , by controlling the waveform and the waveform output timing of the triangular wave signal TRI as described above, the period in which the modulated signal PWM is kept in the high level is reduced to half of the period in which the original modulated signal is kept in the high level, and is then output, and the process proceeds to the step S 216 .
Further, in the step S 214 , by controlling the waveform and the waveform output timing of the triangular wave signal TRI as described above, the period in which the modulated signal PWM is kept in the low level is reduced to half of the period in which the original modulated signal is kept in the low level, and is then output, and the process proceeds to the step S 216 .
In the step S 216 , the output voltage value V retrieved in the step S 203 is output to the D/A converter 33 , and the process proceeds to the step S 217 .
In the step S 217 , the modulation frequency fpwm retrieved from the memory 31 is output to the modulator 26 (the triangular wave oscillator 34 ), and the process proceeds to the step S 218 .
In the step S 218 , the operation stop signal /Disable is set to be in the high level, and at the same time, the digital power amplifier circuit 28 and the modulator 26 are made to operate, and the process proceeds to the step S 212 .
In the step S 212 , the process waits until the read timing of the memory 31 , and then proceeds to the step S 220 .
In the step S 220 , the memory address counter N is incremented, and then the process proceeds to the step S 203 .
According to the arithmetic processing, since it is arranged that the drive waveform signal WCOM is stored in the memory 31 as the output voltage value (the drive waveform voltage data) V, the controller 32 calculates the difference of the output voltage value (the drive waveform voltage data) V retrieved from the memory 31 , and the operation of the digital power amplifier circuit 28 is stopped if the difference in the output voltage value (the drive waveform voltage data) V is 0, the memory 31 with small capacity can be adopted in addition to the advantages of the first and second embodiments described above.
Then, a modified example of the actuator drive circuit described above will be explained. FIGS. 18A and 18B are block diagrams showing another example of the actuator drive circuit. This actuator drive circuit is similar to the actuator drive circuit shown in FIGS. 7A and 7B described above, and the equivalent constituents are denoted by the equivalent reference numerals, and detailed explanation thereof will be omitted. In the actuator drive circuit shown in FIGS. 7A and 7B described above, the controller 32 outputs the operation stop signal /Disable to the gate drive circuit 30 , and when the operation stop signal /Disable is in the low level, both of the high-side switching element Q1 and the low-side switching element Q2 of the digital power amplifier circuit 28 are OFF to thereby stop the operation of the digital power amplifier circuit 28 . This is because, as described above, in the case in which only one gate drive circuit 30 is provided, and, for example, the gate-source signal GL to the low-side switching element Q2 is obtained by inverting the gate-source signal GH to the high-side switching element Q1, and is then output, it is not achievable to set both of the gate-source signals GH, GL to the high-side switching element Q1 and the low-side switching element Q2 to be in the low level.
Therefore, in the present modified example, the gate drive circuit 30 is provided to each of the high-side switching element Q1 and the low-side switching element Q2. Further, it is arranged that the comparator 35 outputs a pulse-modulated signal PWMP taking the high level when the drive waveform signal WCOM is higher than the triangular wave signal TRI, and an inverted pulse-modulated signal PWMN, so that the pulse-modulated signal PWMP is output to the gate drive circuit 30 for the high-side switching element Q1, and the inverted pulse-modulated signal PWMN is output to the gate drive circuit 30 for the low-side switching element Q2. When stopping the digital power amplifier circuit 28 , namely in the case in which the voltage of the drive waveform signal WCOM does not change, the controller 32 holds both of the modulated signals PWMP, PWMN output from the comparator 35 in the low level. Thus, the gate-source signals GH, GL output from the respective two gate drive circuits 30 are set to be in the low level, and both of the high-side switching element Q1 and the low-side switching element Q2 are OFF. The operation and the stop of the operation of the digital power amplifier circuit 28 are as shown in the truth table shown in Table 2 below.
TABLE 2
Pulse Modulation
Pulse Modulation
Signal P
Signal N
Q1
Q2
Power Amplifier
0
0
OFF
OFF
Stopped
1
0
ON
OFF
Operating
0
1
OFF
ON
1
1
ON
ON
It should be noted that although in the first through third embodiments described above only the case in which the fluid ejection device according to an aspect of the invention is applied to the line head-type printer is described in detail, the fluid ejection device according to an aspect of the invention can also be applied to multi-pass type printer in a similar manner.
Further, the fluid ejection device according to an aspect of the invention can also be embodied as a fluid ejection device for ejecting a fluid (including a fluid like member dispersing particles of functional materials, and a fluid such as a gel besides fluids) other than the ink, or a fluid (e.g., a solid substance capable of flowing as a fluid and being ejected) other than fluids. The fluid ejection device can be, for example, a fluid like member ejection device for ejecting a fluid like member including a material such as an electrode material or a color material used for manufacturing a fluid crystal display, an electroluminescence (EL) display, a plane emission display, or a color filter in a form of a dispersion or a solution, a fluid ejection device for ejecting a living organic material used for manufacturing a biochip, or a fluid ejection device used as a precision pipette for ejecting a fluid to be a sample. Further, the fluid ejection device can be a fluid ejection device for ejecting lubricating oil to a precision machine such as a timepiece or a camera in a pinpoint manner, a fluid ejection device for ejecting on a substrate a fluid of transparent resin such as ultraviolet curing resin for forming a fine hemispherical lens (an optical lens) used for an optical communication device, a fluid ejection device for ejecting an etching fluid of an acid or an alkali for etching a substrate or the like, a fluid ejection device for ejecting a gel, or a fluid ejection recording apparatus for ejecting a solid substance including fine particles such as a toner as an example. Further, an aspect of the invention can be applied to either one of these ejection devices.
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A fluid ejection device includes: a modulator adapted to pulse-modulate a drive waveform signal forming a basis of a drive signal of an actuator to obtain a modulated signal; a digital power amplifier circuit adapted to power-amplify the modulated signal to obtain a power-amplified modulated signal; a low pass filter adapted to smooth the power-amplified modulated signal to obtain the drive signal; and a power amplification stopping section operating when holding a voltage of the actuator constant.
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FIELD OF THE INVENTION
The present invention generally relates to apparatus and methods for acquiring seismic signal and filtering such data. More particularly it relates to designing a digital filter to attenuate the coherent noise while preserving reflection signals on seismic data, particularly in land seismics, but it may also be employed with marine seismic signals.
BACKGROUND OF THE INVENTION
Seismic data is collected to analyze the subsurface of the Earth, and is particularly collected in connection with hydrocarbon exploration and production activities. Seismic data for analyzing subsurface structures may be collected on land or over water. In order to obtain seismic data, an acoustic source is used which typically consists of explosives or a seismic vibrator on land or an impulse of compressed air at sea. The seismic signals reflected by the various geologic layers beneath the surface of the Earth are known as traces and are sensed by a large number, typically hundreds or thousands, of sensors such as geophones on land and hydrophones at sea. The reflected signals are recorded and the results are analyzed to derive an indication of the geology in the subsurface. Such indications may then be used to assess the likelihood and location of potential hydrocarbon deposits.
Seismic surveys are generally conducted using one or more receiver lines having a plurality of receiver station locations spaced evenly along their lengths. In a two dimensional (2D) survey, a single receiver line is used and the acoustic source is typically positioned at various points in-line with the receiver line. In a three dimensional survey, a plurality of parallel receiver lines are typically used and the acoustic source is generally positioned at various points offset from the receiver lines. While a 2D seismic survey can only create a cross-sectional representation of the subsurface, a 3D seismic survey can be used to develop a three dimensional representation of the subsurface.
The desired reflection signals can be masked by noise. Seismic data are subject to a wide variety of noise related problems that can and do limit its usefulness. Broadly speaking, noise found in seismic traces is either incoherent or coherent. Incoherent ambient noise, or uncorrelated “white” noise, is ubiquitous and is generally greatly attenuated through the simple expedient of stacking, although extremely large individual data values (“spikes”) and “bad” traces often need special attention. Coherent, or correlated, noise on the other hand cannot usually be so readily eliminated. Some common examples of coherent noise (some of which affect land surveys more than surveys) include multiple reflections, ground roll generated by the seismic source vibrations, air waves, guided waves, sideswipe, cable noise and 60 hertz power line noise.
In conventional seismic data acquisition systems, data are inherently filtered through use of “hard-wired” (electrically connected) groups of sensors. A group or receiver array delivers a single output trace (the normalized sum or arithmetic average of the output of all individual sensors of the group) at the particular receiver station location about which the sensors are placed. The single trace is the normalized sum or arithmetic average of the output of all individual sensors making up the group.
More recently, however, seismic surveys have been performed using receiver systems referred to as “single sensor” or “point receiver” in which the digital outputs of multiple sensors are [recorded and] processed individually. The inherent filtering effect of the hard-wired group is then replaced by signal filters that are better adapted to the nature of seismic noise and preserve more of the seismic reflection signals. Transition to point receiver arrays for land seismic has been described in “New Directions in land Seismic Technology” in Oilfield Review , Autumn 2005 pages 42-53.
U.S. Pat. Nos. 6,446,008 and 7,584,057 both disclose filtering of signals to remove noise. The latter document discloses use of a mathematical technique, Alternating Projections onto Convex Sets (APOCS), to design multi-dimensional digital filters for land seismic.
Filters for signals are classified as either infinite impulse response (IIR) filters which theoretically produce an output for an indefinite period after receiving an input signal and finite impulse response (FIR) filters which return to zero output within a finite period (or at once) when input ceases. Filters are also classified as adaptive, if the filter coefficients change in response to the signal data encountered (which may be recorded signal data) or as fixed or non-adaptive if the filter coefficients or the manner in which they are calculated is predetermined without detailed knowledge of the signal data.
A filter for digital signals can be implemented in software as computational processing of the signal data (which may be recorded signal data). The filter applies coefficients to alter the amplitude of the signal data and in doing so attenuates parts of that data relative to other parts, with the objective of attenuating the parts which are unwanted noise. Design of such a filter entails computation of the coefficients. The characteristics of a filter are generally referred to as its response.
It is an object of the present invention to provide methods for processing seismic data, particularly methods for designing and applying filters for such data.
SUMMARY OF THE INVENTION
Design of optimal multi-dimensional Finite Impulse Response (FIR) of digital filters is important for seismic data acquisition recorded using point receivers.
In a first aspect, the present invention provides a computational method of processing digital seismic signals received at a plurality of individual sensors spaced apart from one another by applying filter coefficients to signals from individual sensors,
wherein the computational method comprises computing filter coefficients to minimise an l-norm function of differences between a response of a filter with the computed coefficients and a predetermined response which attenuates signals outside a predetermined range of slowness relative to signals within the predetermined range of slowness.
In embodiments of this invention, the predetermined response would generally be unity within a predetermined range of slowness associated with desired reflection signals and a zero value outside this range of slowness. Thus the predetermined range of slowness defines a passband containing the desired signals while outside the passband there are stopbands in which signals are attenuated. The stopbands at either side of a passband are sometimes referred to as sidelobes.
Embodiments of this filter are classed as an FIR filter and also as a fixed (i.e. non-adaptive) filter because filter behaviour is defined without detailed knowledge of specific data.
In some embodiments of the invention the value of l in the l-norm function is 2, so that the function is the mean square of differences between the filter response and the predetermined response. Minimising this function leads to a least mean square difference between the filter response and the predetermined response.
This minimisation of the function may be done with signals at a single frequency creating a narrowband filter suitable for processing signals within a small range of frequencies. However, it may be done with filter responses and predetermined responses over a range of frequencies to provide a broadband filter. Possibly the predetermined response will be the same for the whole range of frequencies.
It is an advantage that embodiments of this invention can provide a filter for seismic data which comprises a plurality of traces representing seismic energy received as a function of time at sensors at a plurality of locations which may be regularly spaced or irregularly spaced. A further advantage is that the filters can be suitable for multidimensional seismic data and so can be used if the receivers are distributed uniformly or irregularly along one or more lines or even if they are distributed irregularly over an area.
In a development of this invention, the coefficients computed by minimising the l-norm function may be subject to additional constraints, for example to smooth the seismic signals.
A method as any above may be carried out to process data as it is received, or it may be used to process seismic signal data which has been stored on a computer-readable storage medium. A method as any above may further include determining one or more parameters related to physical properties of the earth's interior from the processed seismic signals.
In another aspect, this invention provides a method of seismic surveying comprising:
propagating an acoustic or electromagnetic field through at least one subsurface layer of the earth; acquiring data at a plurality of discrete locations; and processing the data according to a method as any above.
The invention also provides a system comprising both an interface to receive data indicative of a signal derived from a seismic acquisition and a computer to process the received data by a method as any above. The invention further includes a computer program comprising instructions for carrying out a method as any above, and a computer readable storage medium having such a computer program stored thereon.
The invention will be further explained and exemplified by the following detailed description and with reference to the accompanying drawings. This description is exemplary in nature and is not intended to limit the scope of the invention. Except where clearly inappropriate or expressly noted, features and components of different embodiments may be employed separately or used in any combination.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows sensor intervals for a set of 45 sensors with irregular spacing along a line;
FIG. 2 shows examples of the amplitude response (against slowness) of the filter which has been computed when the l-norm function is a weighted least square function. The passband is for a slowness range between 0 and ˜0.0005 (sec/meter) in either direction and the stopbands at either side are for slownesses larger than 0.001 (sec/meter) in either direction. FIG. 2 a shows the amplitude-slowness response when the sensor array has 45 sensors on a line with uniform spacing of 5 m interval at frequency of 5 Hz. FIG. 2 b shows the amplitude-slowness response when the sensor array of 45 sensors has irregular spacing as shown in FIG. 1 , also at frequency of 5 Hz.; and
FIG. 3 shows the same examples as shown in FIG. 2 after further constraints are applied and the filter coefficients are calculated by an iterative procedure.
DETAILED DESCRIPTION
Seismic signals of frequency and amplitude are received at each sensor in a set of L sensors. The slowness (reciprocal of velocity) of the signal is also determined from the time difference between the arrival of signals at sensors with a known spacing between them. The data from each sensor is available in digital form.
The following description of the filter design relates to a 3D survey. All positions and slowness are vectors, denoted with bold font, and multiplication between positions and slowness is the dot product.
Denoting the unfiltered primary trace at frequency ω and slowness p as x 0 (ω, p) and the filtered output as y(ω, p) the relationship between them can be formulated as
y ( ω , p ) = ∑ i = 0 L - 1 w i ( ω ) x i ( ω , p ) = ∑ i = 0 L - 1 w i ( ω ) ⅇ - j ω p · x i x 0 ( ω , p ) = H ( ω , p ) x 0 ( ω , p ) ( 1 )
where x i , w i (ω), are the sensor positions and filter coefficients, respectively and i is a series of integers i=0, . . . , L−1.
H(ω, p) is the filter FIR response. It can also be written as
H ( ω , p ) = ∑ i = 0 L - 1 w i ( ω ) ⅇ - j ω p · ( x i - x 0 ) = w T s ( 2 ) where w = ( w 0 ⋮ w L - 1 ) and s = ( ⅇ - j ω p · x 0 ⋮ ⅇ - j ω p · x L - 1 ) ( 3 )
s is the steering vector.
The optimal filter coefficients w can be found by minimizing a weighted l-norm error function between H(ω, p) and a desired response D(ω, p) subject to some linear constraints.
In accordance with an embodiment of this invention the filter coefficients are determined by minimising an l-norm error function (also referred to as a cost function) between the above filter response H(ω, p) and a predetermined desired response D(ω, p) which attenuates signals outside a defined range of slowness relative to signals within the defined range of slowness. This defined range of slowness is referred to as the passband and is selected to contain desired reflection signals but exclude noise. Ranges of slowness outside the passband and are referred to as stopbands (sometimes referred to as sidelobes).
A line of receivers may observe seismic signals travelling in either direction projected on the receiver line. Signals travelling in one direction may be assigned a positive value of slowness while signals travelling in the reverse direction are assigned a negative value of slowness. Consequently the passband may extend over a range of slowness from a negative value through zero to a positive value with stopbands at either side of the passband.
The error or cost function at frequency ω can be written as
J ( w )=∫ U (ω, p )| D (ω, p )− H (ω, p )| l dp
where U(ω, p) denotes a chosen weighting factor which may be employed in some embodiments of the invention. In accordance with this invention, this error function is minimised. Filtering by reference to a desired slowness passband and slowness stopbands imposes constraint on the signals which are being processed and preserves the desired reflection signals with attenuation of unwanted noise signals, such as ground roll.
The result may be an approximation to the desired outcome and further linear constraints on the data may be employed so that the minimized error function is written as
min J ( w )=∫ U (ω, p )| D (ω, p )− H (ω, p )| l dp subject to Cw=f (4)
where C is N×L matrix which defines N linear constraints and f is a N dimensional vector (as mentioned earlier, L is the number of sensors in the set). The choice of l in equation (4) depends on the application of the filter.
In some embodiments of this invention, the value of l in the l-norm error function may be set to 2, so that the error function is the mean squares of differences between the filter response and the desired response. In this case the minimized function at frequency ω and slowness p is a least mean squares function and can be written as
min J ( w )=∫ U (ω, p )| D (ω, p )− H (ω, p )| 2 dp subject to Cw=f (5)
If required, for example to eliminate outlying data points or to reduce their effect on the overall data, some other value of l may be used. One possibility is that l may be set to infinity so that the error function is a minmax function. In this case the minimised function can be written as
min J ( w )=max U (ω, p )| D (ω, p )− H (ω, p ) for all p (exclude transition), subject to Cw=f (6)
The matrix C of linear constraints can be constructed by specifying the response at some particular slowness, or at some slowness ranges, and can be formulated as
( s 1 T . . . s M T ) where s i are steering vectors and i= 1, 2 . . . M , so that ( s 1 T . . . s M T ) T w=f (7)
For the slowness in the pass band (signal protection region), values f in vector f may be set to one, and for slowness in the stop band (noise region), values f may be set to zero.
The derivative of steering vector v with respect to slowness can also be used in the construction of linear constraints. When more constraints are added, the constraints can cease to be independent and the matrix C becomes singular. The principal component analysis technique can then be used to remove the singularity of C.
The equations above refer to an individual frequency ω. They could be applied to a small band of frequencies to provide a narrowband filter. For a broadband filter which is to be used for signals with a wider range of frequencies, the filter FIR response can be written as
H ( ω , p ) = ∑ i = 0 L - 1 ∑ k = 0 K w i , k ( ω ) ⅇ - j ω ( k + p · x i ) = w T s ( 8 )
where
w =( w 0,0 . . . w 0,K−1 . . . w L−1,0 . . . w L−1,K−1 ) T
and
s =( e −jωp·x 0 . . . e −jω(K−1+p·x 0 ) . . . e −jωp·x L−1 . . . e −jω(K−1+p· L−1 ) ) T (9)
The minimised error function (also termed cost function) for determining the optimal broadband filter coefficients can be written as
min J ( w )=∫∫ U ( ω,p )| D (ω, p )− H (ω, p )| l dωdp subject to Cw=f (10)
The linear constraints matrix C is constructed in the same manner as for equation (7) above, using the broadband steering vector of equation (9). If l is set to 2 so that the error function is a least square function, the minimised function can be written as
min J ( w )=∫∫ U (ω, p )| D (ω, p )− H (ω, p )| 2 dωdp subject to Cw=f (11)
and the weighted min-max can be written as
min J ( w )=max U (ω, p )| D (ω, p )− H (ω, p )| for all ω and p (exclude transition) subject to Cw=f (12)
Cost function J(w) as in equation (4) or equation (10) may have local minima and its gradient information is difficult to compute when the value of l is other than 2. Possible methods for computing a solution of these equations which do not use any gradient information of the cost function are Genetic Algorithm and Particle Swarm Optimization (PSO). Use of PSO to determine filter coefficients may proceed as follows
1. Define the search space for each filter coefficient, the size of population, the number of groups, initialize the population by randomly sampling the whole search space and initialize the particle position w n and moving velocity vector v n with zeros. 2. Evaluate the fitness for each particle (more detail for this step is given below) 3. Update the particle moving velocity according to the following equation
v n+1 =bv n +a 1 d 1 ( p best n −w n )+ a 2 d 2 ( g best n −w n ) (13)
where d 1 and d 2 are random positive numbers in the range [0,1], b is the inertial weight that determines to what the particle extend remains along its original direction. pbest n is the best particle in the group, gbest n is the best particle in the whole population. a 2 and a 2 are acceleration constants, which attracted each particle towards its pbest n and gbest n .
4. The new particle position is computed using the following equation
w n+1 =w n +v n Δt (14)
5. Repeat 2-4 until a stop criterion is met.
The fitness function used in step 2 is defined as
fitness = J ( w ) + ∑ i a i s i T w - f i ( 15 )
where a i is the penalty factor and f i is the element off in equation (7).
However, a close-form and computationally simple solution for the weighted least square (i.e. l=2) is also possible. By using the Lagrange multiplier method, the optimal coefficients w of equation (5) can be written as
w opt = A - 1 r - A - 1 C H ( CA - 1 C H ) - 1 ( CA - 1 r - f ) ( 16 ) where A = ∫ passband U ( ω , p ) v ( ω , p ) v H ( ω , p ) ⅆ p + ∫ stopband U ( ω , p ) v ( ω , p ) v H ( ω , p ) ⅆ p ( 17 a ) r = ∫ passband 2 U ( ω , p ) Re ( v H ( ω , p ) ) ⅆ p ( 17 b )
for single frequency filter, and
A = ∫ ∫ passband U ( ω , p ) v ( ω , p ) v H ( ω , p ) ⅆ ω ⅆ p + ∫ ∫ stopband U ( ω , p ) v ( ω , p ) v H ( ω , p ) ⅆ ω ⅆ p ( 18 a ) r = ∫ ∫ passband 2 U ( ω , p ) Re ( v H ( ω , p ) ) ⅆ ω ⅆ p ( 18 b )
for the broadband filter. The first term in equation (16) is the weighted least square solution without any constraints.
The drawings illustrate the application of a filter embodying this invention. In this illustration the signals are seismic data from a 2D seismic survey with 45 sensors. These are either in a uniform linear array with 5 meter spacing or an irregular linear array as shown by FIG. 1 which shows the sensor interval, i.e. the distance from the previous sensor in a line.
The sensors observe seismic signals travelling in either direction projected on the receiver line. Signals travelling in one direction have a positive value of slowness while signals travelling in the reverse direction have a negative value of slowness. Consequently the passband may extend over a range of slowness from a negative value through zero to a positive value with stopbands at either side of the passband.
As an example, FIG. 2 shows the FIR response at a frequency of 5 Hz as calculated by the first term of equation (16) which, as mentioned above, is a weighted least square function (i.e. l=2) without added constraints. The slowness passband (also termed signal protection region) is between 0 and ˜0.0005 sec/meter in either direction as indicated by the rectangle P. The stopbands at either side are >0.001 sec/meter in either direction. The slowness range of ground-roll is typically 0.001-0.005 sec/meter as indicated by rectangles G. At low frequency, the transition zone in the wavenumber domain is usually narrow with the same slowness range, which requires high order of filter. At higher frequency, the transition zone becomes wider which does not require a high order of filter. For seismic application, shorter spatial filters better preserve the (local) amplitude information of reflection signal than longer spatial filters. FIG. 2 a shows the amplitude-slowness response of 45 sensors with 5 m interval. FIG. 2 b shows the response of a similar sensor array but with irregular geometry as shown in FIG. 1 . In both FIG. 2 a and FIG. 2 b it can be seen that the slowness range of ground roll is within the part of the stopbands adjacent to the passband. The output of the filter, seen as an undulating trace across the Figures, is approximating the ideal response.
The following iterative procedure is then used to reduce the levels in the stopband slowness range where the ground-roll or any other noises are:
1. Initialize the filter coefficients w with values calculated by the first term of equation (16) 2. The coefficient w is adjusted by Δw. The adjusted term Δw is calculated by finding the solution of the following linearly constrained optimization problem, written as
min Δ w H RΔw+μΔw H Δw subject to CΔw=f (19)
where μ is a positive constant which penalizes large values of Δw, and
R
=
∫
slowness
v
(
ω
,
p
)
v
H
(
ω
,
p
)
ⅆ
p
(
20
)
or
∫
ω
∫
slowness
v
(
ω
,
p
)
v
H
(
ω
,
p
)
ⅆ
p
ⅆ
ω
The slowness range of integration in equation (20) is the slowness range of the ground-roll or any other noise that will be attenuated further to the specified level. The linear constrained matrix C is constructed by the following procedure. For the slowness range of signals, the same constraints of equation (7) with zero response used in the vector f can be used to protect the signals. To adjust the response in the slowness range used in the integration of equation (20) to the specified level, discrete slowness in the range can be used and the response value at each slowness is calculated by the following equation (Tseng and Griffiths, 1992 IEEE Trans. on signal processing, Volume 11 pages 2737-2745)
v
i
H
Δ
w
=
f
i
where
f
i
=
(
ɛ
-
c
i
)
c
i
c
i
(
21
)
c i is the response value calculated using current filter coefficients w, ε is the specified response value. A principal component analysis technique can be used to remove the linear dependency among constraints and therefore the singularity of matrix C of equation (19). The optimal adjusted coefficients Δw is calculated by
Δ w =( R+μI ) −1 C H ( C ( R+μI ) −1 C H ) −1 f (22)
3. Repeat step 2 until convergence when successive values of Δw become small.
In general, the optimization of equation (19) also contains many local minima, the procedure described above can be possibly trapped by one of these local minima. The global optimal solution of equation (19) can be found by the Particle Swarm Optimization (PSO) instead of using equation (22).
FIG. 3 shows the FIR response from FIG. 2 after application of the above iterative procedure. FIG. 3 a is the response when the sensor spacing is regular. FIG. 3 b is the response when the sensor geometry is irregular. Compared with FIG. 2 it can be seen in both cases that the stopband levels are now reduced to below the specified level of 40 dB at all slowness values in the stopband range without significantly broadening the passband.
The filter has good attenuation in the stopbands and only minor ripples within the passband.
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Designing a multi-dimensional Finite Impulse Response FIR digital filter to attenuate the coherent noise while preserving reflection signals on seismic data, particular in land seismics, includes computing filter coefficients to minimize an l-norm function of differences between a response of a filter with the computed coefficients and a predetermined response which attenuates signals outside a predetermined range of slowness relative to signals within the predetermined range of slowness. Additional constraints may be imposed on the coefficients to improve the attenuation of signals outside the predetermined range of slowness of the desired reflection signals, and/or to improve uniformity within the desired range.
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This is a continuation, of application Ser. No. 450,194, filed 3/11/74 and now abandoned.
SUMMARY OF THE INVENTION
The combustion chamber of the rotary internal combustion engine of the present invention is formed of two housings. Each housing is in the shape of a half torus. The toroidal shape is best defined as that generated by a circle, the center of which describes a circumference around an imaginary axis contained in the same plane as the circle, said toroidal shape being uniform and continuous through out the total dimension of its generatrix and defining the inner portions of the two housings. Each housing is defined as that structure defined by dividing said toroidal space at the plane which passes through the circumference of the generatrix of the chamber. At least four pistons are fitted in said chamber. Each piston has the shape of a portion of a torus. The pistons are arranged for cooperative association within said chamber.
The gas-tightness of the combustion chamber is secured by means of four surfaces which fit around the pistons; two fixed and two moving. The two fixed surfaces are formed by the interior portion of two semi-toroidal housings which make up what may be called the engine block. The plane which passes through the circumference generatrix of the chamber will hereinafter be called the "central symmetry plane." The two moving surfaces are provided by two hat-shaped, discs or plates, which rotate in contact with each other. The central symmetry plane which divides the two housings passes through the plane of contact of the two plates. These two straight and parallel plates, which function to provide mobile closure of the chamber, are provided with labyrinth rings, fitted on each side of the central symmetry plane flush with the interior surface of the toroidal chamber. There are two other planes parallel to the central symmetry plane which represent the thickness of the two flanges of said plates. The two hat-shaped discs fit sealably within a slot in the smaller diameter portion of the torus. The two housings are bolted together at the portion of larger diameter. The flanges of the two plates, where they enter the chamber are of a "half round" shape peripherally i.e., they complete the part of the circumference corresponding to the circle of the toroidal chamber which is interrupted by the said plate flanges and, thus ensure the gas-tightness and seating the piston rings. The four pistons are firmly mounted on the flanges of these two plates or discs. Two of the pistons are secured to the flange of one plate; and two to the flange of the other plate. Adjacent pistons are mounted on different plates; i.e., one to one plate, and the following one to the other plate. In this engine the number of pistons is even.
The engine flywheel is located in the central space formed by hat-shaped concavities in the two plates. the drive shaft is connected to the flywheel. Two crankshafts are located off the axis of the flywheel at an angle of 180 degrees to each other (diametrically opposed). The flywheel acts as a bearing for the crankshafts, since the latter are contained within and rotate with the flywheel.
The flywheel, as stated, is situated in the center of the space formed by the two plates, and crank pins of the crankshafts pass through at least one of the hat-shaped plates. In the embodiment described, the crankshafts have crank pins on both sides of the flywheel. Thus each crankshaft has a crank pin which passes through each hat-shaped plate. Both crankshafts are provided with shoes which fit into rectangular openings in the plates, through which the crank pins pass. These rectangular openings serve as slideways on which the shoes slide.
The outer end of each crank pin is provided with a gear which meshes with a gear wheel secured to and centered in the housing of each corresponding side. When the flywheel turns, the crankshaft gears mounted in the flywheel rotate on the gear wheel fixed to the housing, so that the geometric axes of the crankshaft cranks each describe an epicycloid figure when the gear wheels are located inside the circles of rotation of the crankshaft gears and a hypocycloidal figure when the gear wheels are located outside the circle of rotation of the crankshaft gears (ring gear). Each respective slideway gives a reciprocating motion to its relative plates as the crankshafts rotate in the flywheel, giving rise to a cycloidal movement of the pistons in accordance with the relative positions of the two crankshafts, and thereby perform the processes of intake, compression, ignition, expansion, exhaust and scavenging of the residual gases.
The interchange of power between the plates fitted with pistons (pressure of combustion and kinetic energy) and the flywheel, is brought about due to the crankshafts being mounted on the flywheel, the flywheel acting as a mobile bearing for the crankshafts, and since the flywheel is connected on one side to the driving torque by means of the crankshaft and the two plates, and on the other side by means of the drive shaft to the resistance torque, the result is that the active forces of the reciprocating parts produce a working effect on the flywheel.
The shoes which slide on the slideways can be thought of as connecting rods of infinite length.
For a better understanding of the invention reference is made to the accompanying drawings presented, by way of example only, and in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows, in section along Y 3 -Y 5 of FIG. 8, the general configuration of a preferred embodiment of the assembled engine of the present invention;
FIG. 2 shows, in section, an exploded first housing portion of the engine of FIG. 1;
FIG. 3 shows a pair of diametrically opposed pistons appropriately configured for utilization in the preferred embodiment of the instant invention as configured for operative association with the housing portion of FIG. 2;
FIG. 4 shows, in further detail one of the hat-shaped plates of the present invention with pistons attached, exploded to facilitate explanation;
FIG. 5 shows the preferred flywheel and associated crankshaft of the present invention;
FIG. 6 shows a second pair of diametrically opposed pistons attached to the perimeter of a second hat-shaped plate;
FIG. 7 shows, in section, a second housing portion of the basic engine, which portion in conjunction with the housing portion of FIG. 2 may be considered the basic engine block of the invention;
FIG. 8 shows, an along-axial view of the preferred embodiment of FIG. 1 with the combustion chamber cut away along Y 3 -Y 4 to reveal internal details;
FIG. 9 shows details of the four pistons of the basic engine of the present invention provided with suitable compression rings, two of the pistons being shown in the position of closest proximity in accordance with a principle of operation of the present invention;
FIG. 10 shows, cut away along lines Y 3 -Y 4 to show internal details, the same basic assembly as that, viewed from the other side, of FIG. 8 except that here are shown the gear and associated wheel integral with the housing portion;
FIG. 11 shows in outline one housing portion stripped of pistons and associated mechanisms;
FIG. 12 shows a first portion of an operation cycle;
FIG. 13 shows a second portion of an operation cycle;
FIG. 14 shows a third portion of an operation cycle;
FIG. 15 shows a fourth portion of an operation cycle;
FIG. 16 shows a fifth portion of an operation cycle;
FIG. 17 shows a sixth portion of an operation cycle;
FIG. 18 shows a seventh portion of an operation cycle;
FIG. 19 shows an eighth portion of an operation cycle;
FIG. 20 is identical to FIG. 12, showing the completion of the operating cycle;
FIG. 21 is a schematic representation of a characteristic of the basic engine of the present invention;
FIG. 22 shows a shoe in plane and in elevation suitable for incorporation in one housing of the engine of the instant invention, the shoe being provided with a needle bearing;
FIG. 23 shows in an enlarged scale relative to FIGS. 1-20, in section, an assembled engine with the various components thereof shown in detail;
FIG. 24 shows the meshing planetary gears of the crankshafts 5 and the wheel 6 of FIG. 23;
FIG. 25 shows, schematically, an operating characteristic of a crankshaft of the engine;
FIG. 26 shows mounting of the preferred pistons and the provision of gaps therein for uncovering the ignition opening or openings to facilitate entry of gas to appropriate spark plugs;
FIG. 27 shows a section of the engine through a normal plane of any given piston;
FIG. 27' demonstrates that the plane of FIG. 27 is tangent to the one of the two faces of the grooves shown in FIG. 27;
FIG. 28 shows a diametrical section of a plate through the centers of the pistons associated therewith; and
FIG. 29 shows a cross sectional view of one half of the housing in which the gear is in the form of a ring with internal teeth.
FIG. 30 shows a perspective view of gears having helical teeth.
FIG. 31 shows a perspective view of gears having herringbone teeth.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
As previously stated, the description up to this point refers to the basic engine which is made up of fourteen parts. The parts of the basic engine are as follows (the numerals or capital letters after each part refers to reference designators in the drawings):
2 Housings, A and B; Housing A, FIG. 2, housing B, FIG. 7.
2 discs or plates, Pa and Pb; FIG. 3.
4 pistons, 1a, 1b, 2a, 2b; FIG. 9 mounted on plates Pa and Pb.
1 Flywheel, 3; FIG. 5.
1 crankshaft, 4; FIG. 5. Left hand crank 4Ca; right hand crank 4Cb.
1 Gear, 5; FIG. 5. Mounted on one end of the crankshaft 4.
1 Gear wheel, 6; FIG. 2. Fixed on housing A.
2 shoes, 8; FIG. 22 of crankshafts 4.
The ports in housing A and B are not detailed as parts. The ports are merely openings in the housings.
If an attempt were made to balance the single crankshaft basically required for this engine by means of a fixed mass, as is usually the case with engines provided with crankshafts, it would only be possible to do so approximately, because a crankshaft being an eccentric mass, its center of gravity varies continually as it rotates within the uniform mass of the flywheel. At best, only an approximate balance is achievable by means of a fixed mass.
For this reason, placing another exactly similar crankshaft in the flywheel, with the center of rotation diametrically opposed (at 180 degrees) and at the same distance from the center of the flywheel, provides a balance in which the circular imbalance contributed by one crankshaft is balanced by an equal but opposite imbalance contribution by the other. If instead of having two crankshafts diametrically opposed, three are placed in a staggered position (at 120 degrees between each) they will still be mathematically balanced, as also if four crankshafts are fitted at 90 degrees between each. As will be appreciated, the number of crankshafts, if suitably placed, will not alter the operation or basic cycle of this type of engine and the number, up to two, serves principally, to balance the engine. More than two will reduce the specific load. Further, instead of a single gear wheel fixed to one housing, two may be used, one on each housing, and consequently, the crankshafts may be fitted with a gear at each end, each gear running on the gear wheel of the respective housing. This promises better distribution of the driving efforts, dynamic and static balance and a lower work load. It will be appreciated that if, for example, four crankshafts are available, with a gear at each end, four gears will run on each of the two gear wheels of the housings.
OPERATION
In Housings A and B there are several openings or ports which are to be used for the four operational strokes of this engine: intake, compression, ignition-expansion, exhaust and scavenging of the residual gases. As will be appreciated, apart from the four strokes, mention is made of scavenging or ventilation which does not comprise a motion or accessory stroke in the motion of the pistons, but this is carried out following commencement of the exhaust stroke, as will be detailed later.
FIG. 1 shows the basic engine arrangement of this invention with a section showing the flanges 23a and 23b of the relative plates which in their periphery are of half round shape 33 and support the corresponding pistons. In FIG. 2 housing A is shown provided with a gear wheel 6. In FIG. 3 can be seen the two pistons 1a and 2a, diametrically opposed and fixed to plate Pa. Plate Pb is shown with the corresponding pistons 1b and 2b in FIG. 6; gear 5 of the crankshaft 4 is shown on FIG. 5. The plates Pa and Pb, as shown in the detail of FIGS. 26 and 28 are provided with an opening 9a, radially elongated, with two flats or surfaces 9r well polished and perpendicular to the face of the plate Pa, FIG. 26, between which the rectangular shoe 8 slides; shoe 8 is mounted through its center hole 24 on each of cranks 4Ca and 4Cb of the crankshaft 4.
FIG. 8 shows the engine cut away along Y 3 -Y 4 of housing B, pistons 1a, 2b secured with bolts 22, and provided with the necessary compression rings 12 similar to those used for this purpose in conventional engines of the gasoline of diesel types, exhaust port 18b, scavenging port 19b, intake port 17b (partly cut away), slideway 9b and shoe 8b. Since basically only one gear 5 is necessary, there is none shown on this side of the engine in FIG. 8. FIG. 10 shows the same assembly looking from the other side and, cut away, along the same Y 3 -Y 4 as in FIG. 8, except that in FIG. 10 gear 5 and wheel 6 are shown integral with the housing A.
FIG. 9 shows details of the four pistons 1a-2a and 1b-2b provided with rings 12 and mounted on two plates Pa and Pb, of which we only see plate Pa. FIG. 9 also shows slideway 9a, gear 5 of the crankshaft and the engine shaft 7 integral with flywheel 3 (the flywheel is shown in FIG. 23). When the assembly of FIG. 9 is introduced into the housing A, gear 5 meshes with gear wheel 6, as in FIG. 10. As the flywheel rotates, the gear 5 rotates on wheel 6 which serves as a track. With the external-tooth gear wheel 6 shown in FIG. 10, the crank pin in the gear 5 describes an epicycloid. The center line Y 1 -Y 2 in FIG. 10 coincides with the opening 14 (FIGS. 8 and 10) for the spark-plug in the theoretical position of ignition and serves as a reference line for the relative arrangement of the three classes of ports 17, 18 and 19.
FIG. 12 shows the assembly of FIG. 9 mounted on housing A. In FIG. 12 pistons 1a and 2a are integral with the plate Pa (not shown). The slideway 9a, shown in dotted lines, is on plate Pa and slideway 9b is on plate Pb.
In the basic engine, containing the minimum possible number of four pistons, gear wheel 6 is double the diameter of gear 5 on the crankshaft crankpin; i.e. the ratio of 2:1.
Referring again to FIG. 9, we see that the assembly to be fitted into the two housings has the pistons in the position of closest proximity (1b and 1a ) and, diametrically, pistons 2b and 2a in a corresponding position of proximity. Due to the arrangement of the pistons on the two plates, pistons 2a and 1b and, diametrically, pistons 1a and 2b are at maximum spacing. The position shown in FIG. 9 corresponds to the moment of firing. Upon firing the gases compressed between the pistons 1a and 1b expands causing pistons 1a and 1b to separate. As stated, each plate Pa and Pb is connected to the crankshaft by means of corresponding slideways 9a and 9b and shoes 8a and 8b. On ignition, the pistons 1a, 2a, 1b, 2b, cause the crankshafts 4ca and 4cb (FIG. 23) to rotate, so that gear 5 turns under its own power, on gear wheel 6, which serves as a track and draws flywheel 3 with it. The combined motions give rise to the desired composite cycloidal motion of the crank pins resulting in reciprocal motion of the crankshaft supported by the turning motion (pull) of the flywheel. The result is as follows:
(a) since the timing crankpins 4Ca and 4Cb (FIG. 23) are in opposition (at 180 degrees), the relative slideways transmit a turning torque to crankshafts 4, so that when gear 5 turns on gear wheel 6, the whole assembly of flywheel-crankshaft-plates-pistons is forced to rotate on gear wheel 6;
(b) since the motion of each crankpin is epicycloidal the slideway of plate Pb deducts the advance caused by gear 5 on gear wheel 6, from the amount given by the epicycloidal motion in the opposite direction to the rotation of the flywheel;
(c) the slideway of plate Pa adds the advance produced by the same cycloidal phenomemon to plate Pa. FIG. 13 shows that when the flywheel has moved 45 degrees, gear 5 has rotated 90 degrees. Cranks 4Ca and 4Cb of the crankshaft will be in the position indicated in the figure. A similar analysis can be done in which the gear 6 has internal teeth as shown in FIG. 29. In that case, the motion of the crankpins is hypocycloidal rather than epicycloidal.
FIGS. 11 to 20 trace the relative motions of the various components in a full rotation of the flywheel. FIG. 11 represents housing A, gear wheel 6 centered relative to the turning axis of the engine, and spark-plug opening 14. Ignition advance can be achieved using additional offset ports 15 or 16 as spark-plug locations depending on the direction of rotation of the engine. For unidirectional engine rotation only one spark-advance port is needed.
It is possible to make the engine rotate in either direction, but for purposes of description, rotation in the clockwise direction indicated by the arrow in FIG. 12 is assumed. FIG. 12 shows toroidal semi-chamber A including, spark-plug opening 14 then, continuing clockwise, the exhaust port 18, the scavenging port 19 adjacent the exhaust port 18, and the intake port 17.
It is important to an understanding of the engine to realize that both ends of each piston are active. After the leading face of a piston completes its function, for example, it moves into a position such that its trailing face assumes the function previously done by the trailing face of the piston just ahead of it. Thus the four pistons effectively divide the toroidal combustion chamber into four regions in which the functions can be analogized to similar functions in a conventional engine.
Since the engine shaft is integral with the flywheel any reference to rotation of the shaft is equivalent to rotation of the flywheel.
The following discussion with reference to FIGS. 12 through 20 traces the activity in each of the four regions of the toroidal combustion chamber through a single revolution of the flywheel:
FIG. 12.-1b-1a: combustion, 1a-2b; end of expansion and beginning of exhaust; 2b-2a; end of exhaust and of scavenging of gases, and beginning of intake, 2a-1b; beginning of compression.
FIG. 13.-1b-1a: expansion, 1a-2b; exhaust, 2b-2a, intake; 2a-1b, compression.
FIG. 14.-2a-1b: combustion; 1b-1a, end of expansion and beginning of exhaust; 1a-2b, end of exhaust and of scavenging of gases and beginning of intake; 2b-2a, beginning of compression.
FIG. 15.-2a-1b: expansion; 1b-1a, exhaust; 1a-2b, intake; 2b-2a, compression.
FIG. 16.-2b-2a: combustion; 2a-1b, end of expansion and beginning of exhaust; 1b-1a end of exhaust and of scavenging of gases and beginning of intake; 1a-2b, beginning of compression.
FIG. 17.-2b-2a: expansion; 2a-1b, exhaust 1b-1a, intake; 1a-2b, compression.
FIG. 18.-1a-2b: combustion; 2b-2a, end of expansion and beginning of exhaust; 2a-1b, end of exhaust and of scavenging of gases and beginning of intake; 1b-1a, beginning of compression.
FIG. 19.-1a -2b: expansion; 2b-2a, exhaust; 2a-1b, intake; 1b -1a, compression.
FIG. 20.-Identical to FIG. 12.
The kinematic study of the above-mentioned figures shows us that the pistons rotate at the same average speed as the flywheel and its shaft, and in one rotation of the engine shaft four explosions occur. Therefore, this four piston engine is, in so far as the number of explosions is concerned, equivalent to a conventional eight cylinder engine (Beau de Rochas cycle).
The rotary motion of this engine gives rise to a centrifugal scavenging phenomenon which helps to carry out the fourstroke cycle. The centrifugal scavenging phenomenon does not occur in straight-line chamber engines. Also, the arrangement of its parts and the way the parts function together make this engine different from any other rotary engine.
The centrifugal scavenging phenomenon is described with reference to FIG. 11. As the engine rotates, centrifugal force tends to move fresh and burned gases toward the portion of the chamber of largest diameter. Consequently, when the piston begins to uncover the exhaust port 18a, the burnt gases are urged through ports 18a due not only to their inherent kinetic energy resulting from heat and pressure but also due to the centrifugal force acting on them. The outgoing energy of the exhaust gases causes a partial vacuum in the chamber. While the burnt gases are being exhausted through port 18a, the piston uncovers scavenging port 19a located in the region of smallest diameter and allows fresh air to enter at atmospheric pressure. Centrifugal force aids the entry of air through the scavenging port thus further clearing burned gases from the chamber. As the piston continues to move clockwise, the intake of carburetted gases is carried out by a piston uncovering port 17a and the following piston closing the exhaust and scavenging ports. The intake port 17a is located in the portion of smallest radius of the torus (see FIG. 10), adjacent to the "half rounds" 33 (FIG. 1) of the plates Pa and Pb. The centrifugal force of gases in the combustion chamber also aids charging during the intake stroke. Although the arrangement of the exhaust, scavenging and intake ports described in the preceding improves the operation and the power output of the engine, it is to be understood that the engine will operate if scavenging port 19a is dispensed with. Improved operation is obtained if dual intake outlet and scavenging ports are arranged; i.e. in both housings.
FIG. 23 gives a practical example of the engine of this invention. In this figure it can be seen that the chamber is completely closed by the two housings A and B, at the smallest diameter of the torus by the two plates Pa and Pb. The labyrinths 13 which ensure the gas tightness of the junctions of the plates with each other and with the housings A and B are also shown. The flywheel 3 is shown in section containing two crankshafts 4 each provided with gears 5 at each end; two fixed gear wheels 6, (a and b) one on each housing and shaft 7. It can also be seen that the engine is provided with exhaust ports 18a and 18b in each housing. The engine is provided with a single scavenging port 19b in housing B, as stated previously, but it may also be provided with another 19a in housing A (FIG. 11 and 12). It can also be seen that the exhaust ports 18 (a and b), scavenging ports 19 (a and b) and intake ports 17 (a and b) have longitudinal windows or grooves, in the direction of the motion of the pistons, these ports are grid shaped to prevent the rings 12 from fouling the edges of the ports. The seals 42 prevent losses of lubricating oil.
As shown in FIG. 22, shoe 8 may be provided with needle bearngs 24r in order to reduce friction, both at the opening for the crank of the crankshaft and at the surface which slides on the flats 9r of the relative slideway.
FIG. 24 shows gear 5 as seen from the side of housing A with keys 34 meshing with gear wheel 6. Gear wheel 6 is fixed to its housing by means of bolts 38 (FIG. 23). Gear 5 and gear wheel 6 may have straight axially directed teeth as shown in FIGS. 2, 3, 5, 9, 10, 23 and 29 or they may have helical teeth as shown in FIG. 30 or they may have herringbone teeth as shown in FIG. 31.
The pistons may be provided with gaps 41 (FIG. 26) for the purpose of uncovering without delay the ignition opening or openings, facilitating in this way the entry of the gas to the spark-plugs and reciprocally the subsequent exit of the spent fuel.
FIG. 27 shows a section of the engine through a normal plane Y 6 -Y 7 (FIG. 27') of any piston. This plane is tangent to one of the two faces of groove 36, FIG. 27'. The grooves 36 carry the rings 12 when the pistons are mounted on the flanges 23a and 23b of the plates Pa and Pb carrying them. The ring seats on both walls of the groove of the piston (1 and 2, a and b), and at the same time on the wall of the groove of the flange (23a and 23b) as is indicated in FIG. 27, by numeral 37 directed to three points on the same plane. Therefore, the ring 12 (FIG. 28) is seated around the circumference of the combustion chamber and the periphery of the two plates Pa and Pb and also, in the side faces of the grooves, at point 37.
FIG. 28 shows a diametrical section of plate Pb through the center of the pistons 1b and 2b. The grooves of the labyrinths 13 can be seen (in this case only one groove at each side is shown to allow them to be illustrated in larger size, since the number of labyrinth seals depends on the extent of sealing or hermeticity it is desired to attain). Two sliding surfaces 9r of the slideways can also be seen.
The crankshaft C, as will be appreciated in FIG. 25, can be integral with the gears 5, and be provided with grooves 31 for needle, ball or roller bearings, etc.
The preceding description of the engine has been directed to a basic configuration using the minimum number of parts with which it is possible to build it. The characteristics of this engine allow the horsepower to be increased or smoother operation to be obtained by multiplying some of the components. For example, the following table gives an idea of the possibilities of this engine. The number of spark plugs ("spark plug" means the areas of the chamber where ignition may be carried out. Several spark plugs may be used at each such point.) is equal to the number of pistons divided by four; the same applies to the three classes of ports; 17, 18 and 19.
In this table, the keys are as follows:
T 1 , number of pistons.
T 2 , number of spark plugs.
T 3 , number of explosions during each turn of the flywheel.
T 4 , ratio of gear wheel 6 to crankshaft gear 5.
______________________________________T.sub.1 T.sub.2 T.sub.3 T.sub.4______________________________________ 4 1 4 2:1 8 2 16 4:112 3 36 6:116 4 64 8:1______________________________________
When the ratio of gear wheel 6 to crankshaft gear 5 is greater than 2:1, gear wheel 6 may be made with interior teeth as shown at 60 in FIG. 29 and, consequently, gear 5 is then arranged to engage internally (on the concave side) of the gear wheel. Then the center of rotation of the crankshaft on the flywheel is then situated at the least possible distance from the flywheel shaft. Further, in arranging the meshing of gears 6-5 in this way, the curve described by crank 4 of the crankpin of the crankshaft is hypocycloidal.
In FIGS. 1, 7, 23, 27 the numeral 20 indicates the water cooling arrangement passing via ports 26a and 26b (FIGS. 8 and 9) from one chamber to another. Water inlets and outlets 21a and 21b are shown in FIGS. 1, 8, 10 and 23.
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A rotary internal combustion engine block has a toroidal combustion chamber of circular section. At least four pistons fitted in said chamber perform discontinuous unidirectional circular motion about the center of the toroidal combustion chamber. At various stations about the torus, an air-fuel mixture is introduced between adjacent pistons, the adjacent pistons approach each other resulting in compression of the air-fuel mixture, the mixture is ignited, and gas expansion drives the adjacent pistons apart. The mechanical energy of the pistons being moved apart by the gas expansion is coupled through a drive shaft to the load.
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RELATED APPLICATIONS
This Application claims benefit of U.S. Provisional Patent Application 60/629,550, filed Nov. 22, 2004, and titled INCREASED METHANE PRODUCTION FROM COALBED DEPOSITS BY ACOUSTIC VIBRATION OF EXHAUST WELLS, by the present inventor, Dimitri A. Kas'yanov.
BACKGROUND
1. Field of the Invention
The present invention relates to devices and methods for increasing the permeability of porous and fractured media with acoustic stimulation, and more particularly in once instance to methane and natural gas extraction from coalbed deposits, and acoustic borehole equipment to increases the gas permeability of the media surrounding the borehole inside faces of exhaust wells.
2. Description of the Prior Art
Methane, firedamp, or natural gas, is a normal constituent of every coalbed deposit, and are formed in situ by Nature when the coalbed takes form. Such gases are adsorbed by the coal, e.g., they occupy the particle surface areas over the entire parent coal matrix. The adsorption surface area of coal can be very large, e.g., about one billion square feet per ton of coal. The gas stored in a coalbed can be significantly more than the gas found in a typical and otherwise similarly sized natural gas deposit. Such methane and carbon dioxide do not freely migrate through the coalbed deposits. They have to be induced to release from the coal, e.g., by venting to a lower atmospheric pressure.
In contrast, methane deposited in sand or sandstone is not adsorbed by the sand material itself, and is usually able to flow relatively well through the cavities, cracks, fissures, and spaces between the sand particles.
Every coal deposit includes some amount of methane that can make mining the coal dangerous. As a general rule, the amount of methane adsorbed is proportional to the grade of the coal. The higher the coal grade, the higher will be the gas content. Also, the deeper the coalbed, the higher will be its gas content. The pressure in the coalbed is proportional to its depth, and the degree of gas sorption increases with such pressure. A desorption isotherm can be used to predict the reduction in pressure, for a given temperature, that will be needed to get the gas to desorb and seep out to exhaust well collectors.
Coal beds are very often inundated with ground water. The hydrostatic pressure of such water will add to the total pressure in a coalbed and a concomitant increase in the gas sorption. The desorption isotherm shows an appropriate level of decrease in the hydrostatic pressure needed to recover the methane from the coal.
In the past, the collection methods and equipment needed to harvest the methane from a coalbed simply did not exist. So no profit could be make from the methane. Such methane had always been considered a nuisance because it poisoned the air the miners needed to breath, and thousands of times it has proved to be explosively deadly. Even today, when modern methods and equipment can be employed to great success, serious and frequent mining explosions and disasters continue to occur that could have been avoided if the firedamp had simply been removed before coal mining operations began. These accidents have been especially common recently in the coalmines of Russia and China. But no coal mine in the world is immune.
Methane production ahead of mining has become a widespread way to protect against methane-related accidents and to increase profits by selling off the collected methane. In fact, harvesting the methane from coalbeds or strata too deep or too poor to support profitable coal production is becoming an attractive way to convert hydrocarbon reserves into revenues.
Coalmine gas production holes were once simply used to help ventilate mines and to minimize the coal-production risk due to mine gases. Now, coalmine operations recognize that profits can be made by gas production and sales. Simply releasing the gas into the atmosphere is a waste of money, and contributes to environmental pollution. In the last time, the experience in mine degasification led to development of projects of gas production independent of coalmine operation.
Widely used methods for coalbed gas production include vertical and horizontal boreholes drilled to degasify the deposits before starting coal mine production, vertical gassers in waste rock, and vertical or directionally drilled boreholes independent of any intent to later mine coal. Prior art methods for coal methane production have included injecting a second gas, such as nitrogen, carbon dioxide, or vitiated air into coalbeds to force out the natural gas. A system of injection and collector holes is drilled to do this.
A number of factors will determine the profitability of gas production from coalbeds. For example, the actual gas content, the pressure in the coalbed, the presence of water, and the “penetrability” all affect how much gas can be recovered and at what cost. A fracturing pattern inside a coalbed, called “cleavage,” is one factor that determines the in-place penetrability. Cleavage and stratification can ease the flow of gases and fluids inside a coalbed.
For example, a coalbed with a low gas content and a high hydrostatic pressure on the desorption isotherm requires extra production of water for every unit of produced methane. Similarly, gas recovery from a coalbed with a very low penetrability requires intense destruction. In many cases, efficient gas recovery is not possible because appropriate production-enhancement technologies do not exist.
The drilling-in of a borehole in a coalbed causes a localized pressure relief and produces a pressure gradient as the methane flows to the output. A diffusion flux is generated through the coal matrix with a laminar flow through fractures the coalbed around the borehole. Ground water is pumped out to reduce the coalbed pressure enough so the gas can desorb from the coal. The faster the water removal, the faster will be the consequential release of the retained gas. The gas volume output that can be realized by an exhaust well is mainly determined by the penetrability or permeability of the wall and bottom faces of the borehole. Such faces behave like a filter matrix, and the important areas involved in restricting the gas flow the most are not more than a few diameters away from the exhaust well in the collector zone. Therefore, the more permeable that such immediate area around the exhaust borehole can be made, the higher will be the volume of gas produced.
Coal has an elastic nature to its solid makeup that can cause the pores in it to close or restrict gas permeation when subjected to large pressure gradients. The pressure gradients are highest immediately around the exhaust well borehole, and the “filter” area at the perimeter radius is minimum. The pressure isobaric curves form concentric cylindrical zones around the core. Those farther from the exhaust well inside faces have the larger surface areas. The pressure gradients are greatest immediate to the exhaust well inside faces, and the surfaces areas are minimum. The combination closes the gas pores and limits permeability nearest the inside faces. Such observation can also be expressed mathematically.
The formula for a pressure gradient distribution in a one-dimensional radial flow from a circular supply circuit with radius R c , and pressure P c to a concentric borehole with effective radius r b , and face pressure P b , is as follows:
P
(
r
)
-
P
c
=
P
b
-
P
c
ln
(
R
c
r
b
)
ln
(
R
c
r
)
.
Such describes a logarithmic pressure distribution between the supply circuit and the borehole at the center. Most of the pressure differential concentrates at the narrow band nearest the borehole. For example, for R c ≈100 meters, and r b ≈0.1 meter, more than one-third of the pressure difference is dropped across the last one meter to the borehole core. Over one-half is dropped across a zone of radius ≈3 meters. The situation is even more pronounced for boreholes with smaller radii r b .
Mud filtrate and small coal particles can form a filter cake that will reduce or completely shut-down an exhaust well bore. The borehole output for the same face pressure can be considerably reduced by critical-zone pore-clogging, or colmatation. For example, it is estimated a tenfold decrease in penetrability in an area of radius 0.5 meter for r b ≈0.1 meter results in a threefold decrease in the output. If the same decrease in penetrability takes place in an only slightly larger 0.2 meter radius zone, then the output is reduced by much less than before, e.g., 40%. Therefore, a principal benefit of acoustically vibrating the inside faces of the boreholes in porous and fractured media is to increase its permeability.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide methods and systems for increasing the permeability of porous and fractured underground media so that gases and/or liquids can be removed.
It is a further object of the present invention to provide methods and systems for increasing the productivity of natural gas mining.
It is another object of the present invention to provide an acoustic emitter for a borehole drillstring that can be used to intensify natural gas production by increasing the permeability of the surrounding media adjacent to the exhaust wells.
Briefly, a coalbed methane production embodiment of the present invention comprises acoustic radiators strategically placed within exhaust boreholes that sonically vibrate the immediate wall areas. The gas volume output that can be realized by an exhaust well is mainly determined by the penetrability of the inside faces of the borehole. Such inside faces behave like a filter matrix, and the important areas involved in restricting the gas flow the most are not more than a few diameters away from the exhaust well in the collector zone. Therefore, the more permeable that such immediate area around the exhaust borehole can be made, the higher will be the volume of gas produced. Strong sonic vibrations from the acoustic radiators positioned in a drillstring shake-open spaces in the media for the gas to flow out and be collected. The media experiences a type of elastic collapse under the differential pressures that are exerted the strongest near the borehole opening.
An advantage of the present invention is a system is provided for intensifying natural gas production from a coalbed.
Another advantage of the present invention is a natural gas intensification method is provided that is reliable, easy to build, easy to use, economical, and safe in explosive atmospheres.
These and other objects and advantages of the present invention will no doubt become obvious to those of ordinary skill in the art after having read the following detailed description of the preferred embodiments which are illustrated in the various drawing figures.
IN THE DRAWINGS
FIG. 1 is a cutaway perspective diagram of an underground coal deposit that is being drained of its natural gas with an acoustic emitter embodiment of the present invention that stimulates improved permeability of the media immediately around the exhaust well boreholes;
FIG. 2 is a cross-sectional diagram of a hydraulic liquid-whistle type acoustic emitter embodiment of the present invention that could be used in the system shown in FIG. 1 ; and
FIG. 3 is a cross-sectional diagram of a pneumatic gas-whistle type acoustic emitter embodiment of the present invention that could be used in the system shown in FIG. 1 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 represents a coalbed deposit mining operation for natural gas, and is referred to herein by the general reference numeral 100 . A pair of exploratory vertical boreholes 102 and 104 have been drilled from the ground surface to allow for electronic sensors that can imagine and characterize a coalbed 106 . A pair of directional drillstrings 108 and 110 have been used to first bore vertically to the right depth and then horizontally into the coalbed 106 . A paleochannel 112 comprising sandstone represents a typical flaw or anomaly in the coal in the coalbed 106 .
The coalbed 106 has naturally occurring adsorbed natural gas, which is sometimes referred to as firedamp by coal miners. It may also be swamped with groundwater. The depth of the deposit and any groundwater will pressurize the natural gas adsorbed by the coal. The drillstrings 108 and 110 can be used to remove the groundwater and vent any gas pressure. Such will promote desorption and the drillstrings 108 and 110 and their boreholes are used exhaust the natural gas.
The drillstrings 108 and 110 are fitted with acoustic emitters 114 - 121 and pressurizing pumps. Pneumatic or hydraulic pressure flows are sent down drillstrings 108 and 110 so the acoustic emitters 114 - 121 will whistle loudly. Such sound vibrations shake the coal media and increase gas permeability especially near the boreholes. Increased desorption flows result that can be exhausted and sold as methane or natural gas.
The loud whistling from each emitter can be used in a phased array to focus or concentrate sound energy. In such case, the emitters are placed within sound of each other. Otherwise, they are spaced far apart to lengthen their zone of effect along the drillstring.
Embodiments of the present invention are useful to degasify coalbeds with borehole acoustic equipment. In particular, subjecting the near-hole area to strong sound waves improves the penetrability of the media to natural gas. These further include equipment for injecting a second gas into coalbed in order to drive out the desorbing methane.
The choice of what kind of acoustic emitters 114 - 121 to use and how to couple their sound output into the surrounding media are practical challenges that are overcome by the present invention. Electrically operated emitters are dangerous because they can spark an explosion of the very gas being extracted. Connecting them and fitting them with an adequate power source is also problematic. Not placing the emitters in direct contact with the solid inside faces of the boreholes can result in poor acoustic impedance matching, and all the benefits can be lost because strong enough vibrations do not reach the media.
Multiple acoustic radiators 114 - 117 , for example, can be mounted on pipe drillstring 108 at critical points and with critical frequency outputs compared to each other so as to produce a phasing of outputs extend or intensify the media zone in which the permeability is increased so the gases or liquids can be removed.
Mechanical sound radiators not powered by electricity are attractive in this application. Two basic types of mechanical sound radiators can be used, e.g., sirens which have moving parts, and whistles which have no moving parts. Moving and rubbing elements are unavoidable in the design of a siren. Sirens are difficult to manufacture, operate, and maintain. The whistle works by causing the smooth flow of air to be split by a narrow blade, e.g., a “fipple”, creating a turbulent vortex which causes the air to vibrate. By attaching a resonant chamber to the basic whistle, it may be tuned to a particular note and made louder. The length of the chamber typically defines the resonant frequency. A whistle may also contain a small light ball, usually called a “pea”, which rattles around inside, creating a chaotic vibrato effect that intensifies the sound.
Whistles are therefore preferred herein because they need not have any moving parts, can easily be coupled together in strings with pipe sections, can be designed for air or liquid operation, are self-cleaning, and cannot themselves provide a source of ignition of the natural gas.
FIG. 2 represents a hydraulic liquid-whistle type acoustic emitter embodiment of the present invention that could be used in the system shown in FIG. 1 , and is referred to herein by the general reference numeral 200 . The acoustic emitter 200 comprises an upstream pipe coupling 202 to receive a pressurized hydraulic flow 204 , e.g., water obtained from the coalbed itself. A side vent 206 allow a portion 208 of the pressurized hydraulic flow to escape. A whistle 210 connected to the side vent converts the pressure and escaping flow 208 into resonances and therefore sound waves at a particular audible frequency. The whistle 210 comprises an annular nozzle 212 , a ring fluting 214 , an annular rabbetting 216 , and a raised ring fender 218 . A downstream pipe coupling 220 is used to pass along a remaining pressurized hydraulic flow 222 to a next section of pipe.
The side vent flow 208 jets out through nozzle 212 at subsonic velocity. A couple of different designs could be used here. In a first design, the jet is directed toward a vibrating plate that can resonate. Such oscillations can generate strong acoustic energy into the surrounding medium. Unfortunately, vibrating elements such as this fatigue and fail rather rapidly. The better design is shown in FIG. 2 where the liquid jet from nozzle 212 is directed toward a shaped sounding edge that can produce an unstable cavitation cloud. Such shaped sounding edge comprises ring fluting 214 and a resonant cavity formed by annular rabbetting 216 and raised ring fender 218 . Pulsations are emitted by the cavitation cloud can produce strong acoustic oscillations. The development of an acoustic borehole emitter based on such a fluid whistle seems optimal for the case of processing of the near-hole area of an small-diameter exhaust borehole for coal-coalbed degasification, in particular, in the case where the hole is filled with a gas-fluid mixture.
Referring to FIG. 2 , fluid upstream is supplied under pressure to the nozzle from the water main. The fluid flowing out from the nozzle has a certain velocity encounters the fillet 214 . The Bernoulli effect will cause the flow to be partially deflected toward the ring-rabbet area 216 . Here the local pressure is approximately equal to the vapor pressure of the fluid. A toroidal localized cavitation takes shape in the ring rabbet zone. This cavity is bounded from the outside by an elastic envelope in the form of the jet flowing past the rabbet. Material in the cavity is pulse ejected into the surrounding medium, and causes the jet oscillations. The resulting disturbance of the medium will be accompanied by the developed cavitation process and will lead to generation of a complex signal comprising the fundamental tone equal to the frequency of the cavity ejections.
When an exhaust borehole is mainly filled with gas, and not liquid, the contrasting acoustic impedances between the coal and the gas in the borehole can highly attenuate the acoustic-energy coupling into the coalbed. Conventional methods have used wall-lock emitters that must be in direct contact with a vertical borehole wall. But the wall-lock devices are not very practical because they require a predictable and uniform borehole wall. Such is impossible in uncased horizontal degasification boreholes because the borehole cross-section profiles are squashed by lithostatic pressures, and become irregular due to the low rupture stress of the coal. So reliable acoustic contact cannot be reasonably expected.
A suitable gas-medium whistle is the Hartmann radiator type. Hartmann-type emitters generate acoustic oscillations by directing supersonic gas jets from nozzles into resonating cavities. The Hartmann-type radiator is an acoustic emitter with a simple structure that is near ideal in typical borehole conditions. Such acoustic transformer will radiate its acoustic energy directly into the surrounding gas. The small coefficient of transmission of the acoustic field into the gas can be compensated for by the high specific power possible from such type acoustic emitter. It is expected that an acoustic power flux of at least 0.03 watts/cm 2 will be needed for the desired effects.
The output frequency of a borehole acoustic emitter should correspond to the natural resonant frequency of the borehole itself. A typical borehole is about three inches in diameter, and the elastic-wave speeds in coalbeds are about 1500-2000 meters/second for c 1 , and 1000-1500 meters/second for c t . Therefore, a frequency in the 1-5 kilohertz band is indicated. The acoustic impedance of a gas-liquid mixture, as well as a pure gas, is much less than the acoustic impedance of a coal, so the frequency estimates are valid for both cases.
One of the earliest shock wave radiators was developed by J. Hartmann. [See “On the Production of Acoustic Waves by Means of an Air Jet of a Velocity Exceeding that of Sound,” Phil Mag. (7) 11, pp 926-948, 1931; and “Hartmann Acoustic Radiator,” Engineering 142, p 491, (1936)]. This well-known gas-operated sonic radiator, commonly referred to as the “Hartmann” radiator. Such uses pressurized air, e.g., at 100 psi, to create a gas jet directed into a cavity resonator. This creates a sonic output pressure wave in the surrounding air. The Hartmann radiator efficiency improves as a source of sonic energy if it is operated at relatively high input gas pressures.
FIG. 3 represents a pneumatic gas-whistle type acoustic emitter embodiment of the present invention that could be used in the system shown in FIG. 1 , and is referred to herein by the general reference numeral 300 . The acoustic emitter 300 comprises an upstream pipe coupling 302 to receive a pressurized gas flow 304 , e.g., compressed air. A side vent 306 allows a portion 308 of the pressurized airflow to escape. A whistle 310 connected to the side vent converts the pressure and escaping gas flow 308 into resonances and therefore sound waves at a particular audible frequency. The whistle 310 comprises an annular nozzle 312 , a ring throat 314 , and a resonant ring cavity 316 . A downstream pipe coupling 318 is used to pass along a remaining pressurized hydraulic flow 320 to a next downstream section of pipe.
Although the present invention has been described in terms of the presently preferred embodiments, it is to be understood that the disclosure is not to be interpreted as limiting. Various alterations and modifications will no doubt become apparent to those skilled in the art after having read the above disclosure. Embodiments of the present invention are not limited to coalbeds, methane production, or even boreholes. The general invention is to acoustically stimulate porous or fractured underground to make it more permeable. Increased permeability allows increased gas and/or liquid extractions. Accordingly, it is intended that the appended claims be interpreted as covering all alterations and modifications as fall within the “true” spirit and scope of the invention.
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A coalbed methane production method comprises acoustic radiators strategically placed within exhaust boreholes that sonically vibrate the immediate wall areas. The gas volume output that can be realized by an exhaust well is mainly determined by the penetrability of the inside faces of the borehole. Such inside faces behave like a filter matrix, and the important areas involved in restricting the gas flow the most are not more than a few diameters away from the exhaust well in the collector zone. Therefore, the more permeable that such immediate area around the exhaust borehole can be made, the higher will be the volume of gas produced. Strong sonic vibrations from the acoustic radiators positioned in a drillstring shake open spaces in the media for the gas to flow out and be collected. The media experiences a type of elastic collapse under the differential pressures that are exerted the strongest near the borehole opening.
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BACKGROUND OF THE INVENTION
The present invention relates generally to the field of digital computers and particularly to a circuit for resolving contention within a queuing system for use of a shared facility, such as a data bus to and from a common memory, among a plurality of system elements which collectively produce a random rate of request for access to the shared facility.
In digital computer systems and especially systems which have parallel processing capability or multiplexing communication channels, circuits have been developed to resolve simultaneous requests for use of a shared facility such as a data bus. Such circuits, commonly known as Bus Access Controllers, must establish the required priority hierarchy and a means for arbitrating simultaneous bus access requests. Since the arrival time for bus access requests is aperiodic, and at times will exceed the rate which the shared facility can service such requests, a queuing system is thus established. Request queuing requires that units which require fast bus access be given priority at the next request polling sequence.
When the request queue is empty, bus access will be granted to the next unit or units which make a request. In this case controls are required to eliminate ambiguity of access grant when multiple unit access requests are made simultaneously.
Approaches for solving contention for simultaneous access to a shared facility generally use a polling circuit where each request initiates a polling cycle. Such polling circuits fall into two general categories usually referred to as serial and parallel arbiters. In a serial arbiter the polling signal propagates through all the units coupled thereto and the first unit with a request outstanding blocks further propagation of the polling signal and initiates the desired use of the shared facility. Systems using such serial arbiters have slow arbitration speed but economy is achieved by having fewer circuits and control lines on the bus. This approach is quite useful for controlling asynchronous data transfers over a multiplexed bus, for example, but is not always suitable in environments requiring high speed access to the shared facility.
In attempting to improve access time and thereby data transfer capability over a common facility such as a data bus, priority schemes employing parallel arbiter circuits have been developed to grant access to the common facility, first to the unit having highest priority and thereafter to units of successively lower priority thereafter. Such circuit arrangements, however, typically require extensive backpanel signal interconnections and component counts in order to resolve priority amongst a plurality of requesting units. This increased number of circuits has given rise to higher manufacturing cost and has additionally given rise to some reduction in performance due to the fact that several logic circuit levels will be required to resolve contention amongst a plurality of units when the number of contending units becomes quite high.
Accordingly, it is the primary object of the present invention to provide an arbiter for resolving multiple simultaneous access requests for use of a common facility from a plurality of system components which have differing speed requirements for access to the common facility.
It is still a further objective of the present invention to provide an arbiter for resolving multiple simultaneous access requests to a common facility which maximizes performance of the system while keeping circuit costs and interconnection to a level normally found only in slower single level serial arbitration implementations.
SUMMARY OF THE INVENTION
The foregoing and other objectives, advantages and the features of the present invention are achieved by the multi-level arbiter system of the present invention which includes a plurality of loop arbiters. Each loop arbiter includes circuitry for awarding access to a common facility to one of a plurality of externally coupled units. Each loop arbiter includes a plurality of latches for responding to externally generated request signals from external units. The request latches produce a unit request signal and a loop request signal. The unit request signal is utilized by a priority resolution circuit to condition the loop arbiter to grant access to the common facility to the unit producing a unit request signal having the highest priority of all those units producing a unit request signal at the time the loop is polled. The loop request signal is used by a central arbiter to grant access to the shared facility upon receipt of an externally generated loop request signal with access being granted to the loop having the highest priority. The central arbiter establishes a fixed priority sequence amongst the loop arbiters producing a loop request signal at a given moment in time. The central arbiter responds to all such loop request signals present at the given moment of time by polling and latching all such requests and issues a loop grant signal to the loop having the highest priority among all loop arbiters presenting a loop access request signal thereto. Thereafter successively lower priority loops are handled before another polling sequence is made by the central arbiter.
DESCRIPTION OF THE DRAWING
The invention is described below in further detail in connection with the drawings which illustrate a preferred embodiment of the invention and form a part of the disclosure wherein:
FIG. 1 is a block diagram of the system according to the present invention;
FIG. 2 is a block diagram of a loop arbiter according to the present invention;
FIG. 3 is a detailed circuit embodiment of a controller within the loop arbiter according to the present invention;
FIG. 3a illustrates the manner in which controllers of the circuitry of FIG. 3 are interconnected with other controllers to form a loop;
FIG. 4 illustrates the circuits required to construct a central arbiter according to the present invention; and
FIG. 5 illustrates a four level arbiter network.
DETAILED DESCRIPTION
FIG. 1 illustrates the system of the present invention wherein the shared facility comprises a bus 10. Those of skill in the art will realize that the selection of a data bus as the shared facility is merely exemplary of one type of system element which might be shared by a plurality of system components and that the principles of the present invention will apply to the sharing of other types of facilities.
The bus 10, in typical computer systems, comprises a plurality of wires which interconnect the system components, such as processors and memories, and provides a path for communication of control information, data as well as address information between the system components. The exact protocol of the bus 10 need not be described here as it forms no part of the present invention. However, communication over the bus 10 is permitted only when a requesting unit is granted priority by the system arbiter.
The system arbiter of the present invention as illustrated in FIG. 1 is divided into four loop arbiters 12, 14, 16 and 18 as well as a central or parallel arbiter 20. From the subsequent discussion, it will become clear to those of skill in the art that the present invention may be constructed with a single central arbiter and either more or fewer loop arbiters coupled to the central arbiter.
Each loop arbiter, with loop arbiter 12 being exemplary, is coupled to 4 external system units such as unit K3, unit K2, unit K1, and unit K0 by lines 22, 24, 26 and 28 respectively. Each unit comprises a system element that may desire access to a common facility such as a printer which requires data to be printed, the data coming from a memory over the shared facility (bus 10). Each loop arbiter can be designed easily to couple to either more or fewer units. A request for access to the bus 10, for example, is transmitted from unit K3, unit K2, unit K1 or unit K0 over lines 22, 24, 26 or 28 respectively to the loop arbiter 12. The loop arbiter 12 transmits a loop request signal, in response to a bus request from any unit coupled thereto, to the central arbiter 20 via the line 30 designated marlk for Memory Access Request Loop K. At the same time, the loop arbiter 12, by a polling circuit described in greater detail below, determines which unit coupled thereto, and next in turn, has a bus request outstanding. Service is granted to the next unit in turn when the unit currently in possession of bus 10 is ready to release it.
The central arbiter 20, in response to a request for access to the bus 10 from any of the loops, is operative to produce a memory access grant signal to one of the loops. The loop selected for receiving the grant signal is the one which has the highest priority amongst those having an access request pending at a moment in time when the central arbiter 20 determines priority. For the embodiment illustrated in the figures attached hereto, loop K has the highest priority and loop N has the lowest priority with loops L and M being intermediate thereto with loop L having the second highest priority and loop M having the third highest priority. In the event that the central arbiter 20 determines that loop K has a request pending, the central arbiter 20 will produce a memory access grant to loop K on line 30. On the other hand, should the central arbiter 20 determine that loop L is the highest priority loop having a request pending at any moment in time, the central arbiter 20 will produce a memory access grant signal to loop L over line MAGLL. Should the central arbiter 20 determine that loop M is the highest priority loop having a request pending at any moment in time, a grant signal is sent over the line labeled MAGLM. Finally, if loop N is the highest priority loop having a request pending at a given moment in time, the central arbiter 20 will transmit a grant signal over the line designated MAGLN.
As will become clearer from the more detailed discussion of the central arbiter 20 which is set forth below, the central arbiter 20 analyzes all requests pending at a given moment of time and then subsequently issues a grant signal to each of the loops having a request pending at that moment of time wherein the grant signals are transmitted first to the highest priority loop and, after the highest priority loop has been serviced, access is granted to successively lower priority loops until all loops having a request pending at that moment of time have been granted. Thereafter, the central arbiter 20 again determines the loops having requests pending and these requests will be honored in order of the established priority by the transmission of a grant signal thereto.
Referring now to FIG. 2, the interconnection of four typical controllers for requesting external units coupled to a given serial loop arbiter is shown. In particular, this serial arbiter includes a controller for unit 0 of loop N designated 50, where Unit 0 is the first member of the loop to be polled, a controller for unit 1 of loop N designated 52, a controller for unit 2 of loop N designated 54 and a controller for unit 3 of loop N designated 56 where unit 3 is the last member of a loop to be polled. When controller 50 detects a request to access the common facility such as a memory bus, an access request signal is placed on the line 58 which comprises one input to the OR circuit 60. This OR circuit 60 then places a signal on the line 62 designated MARLN which comprises an input to each of the units 50, 52, 54 and 56. The signal on the line 62 initiates a polling cycle for loop N, in a manner described hereinafter in greater detail, which causes one of the controllers 50, 52, 54 or 56 to become conditioned to respond to a "grant" signal from the central arbiter thereby allowing access to the shared facility. The loop request signal for service to the Central Arbiter appears on the line 64 designated MARLN, a mnemonic for Memory Access Request Loop N.
As will be evident to those of skill in the art, controllers 52, 54 and 56 are each capable of making requests for access to the common facility as well and these requests respectively appear on the lines 66, 68 and 70 which are each coupled to input of OR circuit 60.
In the event that the central arbiter determines that the unit requesting service from loop N is to be granted priority and, therefore, access to the shared facility, the central arbiter places a "grant" signal on the line 72 which is designated MAGLN corresponding to Memory Access Grant Loop N. Line 72 is coupled to each of the controllers 50, 52, 54 and 56. As will be described in greater detail later, the unit of loop N requesting service and having the highest priority on the loop will respond to the "grant" signal on line 72 and produce a signal on the line 74 designated AEO which indicates that one controller has set its facility capture latch thereby inhibiting all other attempts to capture the facility. This is accomplished by reason of the fact that the line 74 couples to each of the controllers 50, 52, 54 and 56 and additionally is coupled to all other controllers on all other loops coupled into the system. The signal on line 74 blocks any other facility capture latch from being set.
Once this facility capture signal has been placed on the line 74 indicating that one of the units has captured the shared facility which is an address and command bus for the illustrated embodiment of the invention, the controller then proceeds to place address and commands on the bus coupled thereto and subsequently produce a signal on the line 76 designated ARYO which is a signal transmitted onto the bus to indicate that the data then appearing on the bus is valid.
In the event that the unit sought to be communicated with is for some reason busy and is incapable of responding to the data placed on the data bus by the requesting controller of Loop N, an abort signal is transmitted from the shared facility over the line 78 labeled ABYO. This abort signal indicates the requested shared facility has for some reason aborted its operation and the controller responds thereto by assuring that the unit requesting service releases the bus to other units requesting the shared facility. Since there may be multiple memory banks the unit which receives an ABYO must relinguish the bus so that other units may attempt a successful access to a memory bank which is not BUSY. Memory banks are normally busy when their address and command queue is full. If the unit sought to be communicated with accepts the request for service it will respond with a signal denoting acceptance of the request. This signal is labeled ARO (Address Received).
Line 100 couples to one input of a three input NAND gate 102. Under circumstances when a request is not present as indicated by a high level on line 100, the input levels on lines 104 and 106 are also high. Accordingly, the output 108 from NAND gate 102 is low which couples to one input of a second NAND gate 110 whose output 112 couples to the line 106 and is high. This comprises the reset state for the request latch formed by the interconnection of NAND gates 102 and 110.
When a request is not present, the line 108 is low. This condition is coupled by way of line 114 to one input of a NAND gate 116. The output of the NAND gate 116 goes high and the condition is coupled by a line such as 58, 66, 68 or 70 in FIG. 2 to the negative OR gate 60. In situations where no requests are pending, all inputs to the OR gate 60 are positive and, therefore, the output 62 and 64 is positive. The output 62 in FIG. 2 couples to the line 118 or FIG. 3 for each of the controllers in a given loop. The signal on the line 118 is inverted by the inverter receiver 120 and coupled by the line 122 to one input gate 124. Since the level on the line 118 is high when no request is pending, the level on the line 122 is inverted therefrom thereby inhibiting NAND gate 124 and making the output thereof on line 126 high. Controller 0 of FIG. 2 has its output line designated ALO1, however, this line corresponds to line 126 of FIG. 3.
The line 130 couples to the clock input of a negative edge JK flip flop 132 as well as to one input of the AND gate 134, the 30 nanosecond delay 136 and the NAND gate 138. Under conditions where no request is present, the line 130 is high, the JK flip flop 132 is reset thereby making its output Q high so that the output fron AND gate 134 on line 140 also high. The line 140 in FIG. 3 for controller 3 of FIG. 2 corresponds to line 142 which couples to the input labeled ALI0 for controller 2 of FIG. 2. This line 142 couples to the line 130 of the circuitry of FIG. 3 corresponding to controller 2 of FIG. 2. A similar interconnection will occur between the circuits of controller 2 and controller 1. Accordingly, a loop is established having an AND gate as 134 of FIG. 3 in controller 3 of FIG. 2, an AND gate such as 134 in controller 2 of FIG. 2, an AND gate such as 134 in controller 1 of FIG. 2 and a NAND gate such as 124 of FIG. 3 for controller 0 of FIG. 2. This arrangement is shown schematically in FIG. 3a.
When a request is received at any one of the controllers, the line 100 in FIG. 3 for that controller goes low thereby causing the output of NAND gate 102 to go high thereby producing a unit request signal on line 114. This unit request signal is also transmitted to the NAND gate 110 which drives its output 112 low thereby causing the request latch comprising NAND gate 102 and 110 to become "set".
The J and K inputs to the JK flip flop 132 are respectively coupled to the lines 108 and 112 so that the J input is high and the K input is low. This condition will be discussed shortly.
The high or unit request signal appearing on line 108 is coupled by line 114 to the NAND gate 116 whose other input is usually high and is inverted thereby. This low signal on line MARLN is then coupled by the line 118 to the inverter receiver 120 of the controller 50 on loop N causing a high signal to appear on line 122 which couples to the NAND gate 124. Since the other two inputs to NAND gate 124 are also high, the output on line 126 goes low thereby creating the polling signal which originates in the controller or unit 0 on the loop as shown in FIG. 2. The polling signal is transmitted over a polling line 128 in FIG. 2 to the input line designated ALI0 of the controller for unit 3. As indicated earlier for controller 3, the line designated ALI0 corresponds to line 130 of FIG. 3. The negative going pulse appearing on line 130 is applied to the clock of JK flip flop 132 which becomes set in accordance with the setting of the request latch comprising NANDs 102 and 110. Specifically, if a request has been set into the request latch, the J input will be high and the K input will be low. When the negative going pulse appears on line 130, the JK flip flop 132 becomes set so that the Q output goes high and the Q output goes low. If a request has not been latched by NANDs 102 and 110, the Q and Q outputs of flip flop 132 are reversed from that when a request is latched. When a request is latched, the low output from Q is coupled by line 142 to one input of AND gate 134 and to an input of NAND gate 124. Accordingly, the output on line 140 which already is at a low level remains there until the JK flip flop 132 is reset.
The negative going polling signal appearing on the line 140 is transmitted to similar circuitry in controller 2 which also causes the JK flip flop 132 therein to be set in the event that the request latch in that controller is also set. In a similar manner the polling signal propagates to all the controllers.
It will be noted that during the polling cycle, the negative going polling pulse has a duration in excess of 30 nanoseconds due to the delay 136 in unit 0 of the loop plus the cumulative delay of NAND 124 of unit 0 and of the gates 134 of units 1, 2 and 3. Upon completion of the 30 plus nanosecond delay, the output of delay 136 drives one input to the NAND gate 124 low thereby causing its output at 126 to go high, This high signal is transmitted via line 128 of FIG. 2 to line 130 for unit 3 of the loop. This high signal on line 130 is transmitted by line 143 to one input of NAND gate 138 forming one of the four required conditions for producing a bus capture signal at the output thereof 144. In the event that a request is pending in unit 3, the Q output of JK flip flop 132 is also high thereby providing a second input to NAND gate 138. The two remaining conditions required to set the bus capture latch, indicated generally at 146, are the recept of a signal designated MAGLN which comprises a memory access grant to loop N from the central arbiter which is a signal generated therein in a manner to be described later. The other input required to meet all the conditions for NAND gate 138 is that the line designated AE0 must be high. This condition exists when no other unit coupled to the shared facility is currently granted access thereto.
It will be noted that when JK flip flop 132 is set, Q is low so that line 142 is also low. This low signal on line 142 blocks AND gate 134 and NAND 124. Accordingly, the first controller in the loop to have its JK flip flop 132 set drives line 130 in all subsequent controllers low so that the bus capture latches 146 therein cannot be set. Therefore, the loop hardware provides priority resolution among the units coupled thereto with priority being awarded in order of priority to units 3, 2, 1 or 0.
When all four inputs to NAND gate 138 are high, a low signal appears at 144 which sets the bus capture latch 146 thereby producing a high signal at the output 148. This high output at 148 is inverted by the inverter circuit 150 to produce a low signal on the line designated AE0 which thereafter prevents any other unit from being coupled to the shared facility. The high signal at 148 is also inverted by inverter 152 to produce a low on line 154 which is shown coupled to a plurality of tristate inverter drivers indicated generally at 156. These tristate inverter drivers 156 are made operational by the low level signal on line 154 so that data appearing on the lines indicated generally at 158 is coupled to the shared facility which, in this case, comprises the memory address bus MABXXX indicated generally by the lines 160. When the output at line 154 is high, however, the inverter drivers 156 are not operational so that data on the lines 158 are not transmitted to the bus 160.
The negative going pulse appearing at the output of NAND gate 152 is transmitted by the line 162 to the output timing control 163 which has a JK flip flop 164 which is set by the leading edge of the negative going pulse on line 162. When this occurs, the Q output of JK flip flop 164 produces a negative going pulse on line 166 which is coupled into the delay line 168. A negative going pulse, called T400, appears 40 nanoseconds after the line 166 goes low on the line 170 which is coupled back to the clear input to the JK flip flop 164 thereby causing it to be reset and driving the output on line 166 positive. Accordingly, the pulse T400 with its duration of about 40 nanoseconds is developed in the delay line 168 and is transmitted through driver 180 as signal ARY0. The signal ARY0 indicates the data on the bus 160 is valid. At the same time, the negative going pulse appearing on line 182 designated T400 is coupled to the input to AND gate 184 which drives the clear input to the JK flip flop 132 low thereby resetting it. The reset JK flip flop 132 then has its Q output low and it Q output high. When this occurs, the input condition to the NAND gate 138 changes so that its output goes high. This high level is coupled by line 139 to the input of NAND 110 which causes the request latch comprising NANDs 102 and 110 to be reset.
After a delay of 70 nanoseconds from the start of the pulse at 166, line 172 goes low thereby driving one input to NAND gate 174 of the bus capture latch 156 low. This will reset the bus capture latch 146 thereby causing the voltage at 148 to fall and the output of inverter 150 to go high thus freeing the facility capture latches for other units permitting other units to capture the shared facility.
After a 90 nanosecond delay, a negative going pulse appears on line 176 and is inverted by inverter 177 and which in turn enables the NAND gate 178 thereby enabling any low level operation abort signal on line ABY0 at that time to again set the request latch including NAND gate 102 and 110. Thus if the requested shared facility is unavailable as indicated by the abort signal, then the request latch is again set thereby allowing the request to be reinstated at a later time.
The output timing control 163 described above is exemplary of one such control and how it interacts with the remaining circuitry. Where a particular unit requires transmission of address information as well as data information. The control 163 would be designed to extend the duration of the AEO. The address would be placed on the bus 160 and thereafter the data would appear on the bus. The line ARY0 would indicate by a low level that address information on bus 160 is valid. The delay 168 would latter produce another signal similar to ARY0 to designate at that time that the Data on bus 160 is valid write data.
As indicated earlier, when a request is generated by a unit on a given loop, that request is transmitted to the central arbiter over a line in FIG. 2 designated MARLN. The memory access request from loop N signal, which comprises a low level signal, is inverted by the inverter 200 in FIG. 4. In a similar manner, the memory access requests from loops K, L and M are received respectively on lines MARLK, MARLL and MARLM. An inverter in each such line produces an inverted signal on lines 238, 240 and 242 which are used in a manner described below in greater detail. Assuming that a request for service is outstanding from loop N, the inverted signal at the output of inverter 200 is coupled by line 202 to an AND gate 204 whose other input is coupled to a line 206 which is high whenever all the JK flip flops 208, 210, 212 and 214 are reset. This latter condition is true when there is no previous request pending from any of the loops coupled to the central arbiter of FIG. 4.
When the high signal appears on line 202 indicating the presence of a request for service from loop N, the output of AND gate 204 goes high so that the output of NOR gate 216 goes low. This low signal is transmitted by way of line 218 to NAND gates 220, 222, 224 and 226 thereby blocking these NAND gates and maintaining the output signal on the lines 228, 230, 232 and 234 high. This condition, it will be recalled, is coupled by an inverter driver such as 236 in FIG. 3 to a NAND gate such as 138 in each of the units of the 4 loops coupled to the central arbiter thereby blocking access to the shared facility.
The low signal on line 218 is also coupled to the clock input of all of the negative going edge triggered JK flip flops 208, 210, 212 and 214. These flip flops will be set respectively whenever a high signal appears on the lines 238, 240, 242 or 244 and the clock input is going negative.
Whenever any JK flip flop 208, 210, 212 or 214 is set, the Q output therefrom is high and the Q output is low. The low level signal from any one of the JK flip flops appearing at the Q output is coupled to a NAND gate 246 causing its output to go high. This high level is coupled by line 248 to one input of NAND gate 250 and to a 40 nanosecond delay circuit 252. The output of the delay 252 is coupled to a second input of the NAND gate 250 so that the output thereof on line 206 goes low about 40 nanoseconds after the signal on line 248 goes high. When the signal on line 206 goes low, the output of AND gates 204, 254, 256 and 258 goes low so that the output of NOR gate 216 on line 218 goes high thereby conditioning the NAND gates 220, 222 224 and 226.
As indicated above, when JK flip flop 208 is set by reason of a request being received on line 238 which itself conditions AND 258 and NOR 216 to produce a negative going signal on line 218, the output on line 260 goes high thereby conditioning NAND gate 220 to produce a low level on line 228 whenever the line 218 subsequently goes high. Under the same conditions, the output on line 262 from JK flip flop 208 goes low and this is coupled to one input of NAND gates 222, 224 and 226 thereby preventing the output on lines 230, 232, and 234 from going low. Accordingly, whenever JK flip flop 208 is set, a memory access grant signal is ultimately transmitted to loop K regardless of whether any other loop request is outstanding. In other words, loop K is granted, by the circuitry of FIG. 4, highest priority for use of the shared facility.
Whenever a memory access request is received from Loop L, the signal on line 240 is high which conditions AND 256 and NOR 216 to drive 218 in a negative direction. This causes JK flip flop 210 to become set thereby providing a high level signal on the line 264 and a low level on line 266. The high level on the line 264 is coupled to one input of NAND gate 222. So long as a memory access request is not pending for loop K, the line 268 is high. When the signal 218 goes high, then all the conditions are met so that NAND gate 222 produces a low level signal on line 230 which corresponds to a memory access grant to loop L.
In a similar fashion, when a request is received from loop M, the line 242 is high and the JK flip flop 212 becomes set because AND 254 and NOR 216 drive line 218 in a negative direction. This causes the output on lines 270 and 272 to respectively go high and low. So long as a request is not pending from either loop K or loop L, the lines 262 and 266 respectively are both high so that when line 218 goes high, the NAND gate 224 produces a low level signal on line 232 which corresponds to a memory access grant to loop M.
As indicated earlier, when a request is received from loop N, a high signal appears on line 244 which causes AND 204 and NOR 216 to drive line 218 in a negative direction which sets the flip flop 214. This condition is coupled by way of line 274 to the NAND gate 266. When the line 262 is high indicating a request is not pending from loop K, the second condition for NAND gate 226 is met. A third input to NAND gate 226 is formed by the AND gate 276 whose inputs are coupled to line 272 and 266. Whenever these inputs are high, the output of AND gate 276 is also high thereby providing the third condition to NAND gate 226. Thereafter, when line 218 goes high, the output of NAND gate 226 on line 234 goes low thereby providing a memory access grant to loop N.
From the foregoing analysis of the circuitry of FIG. 4, it is clear that loop K is granted the highest priority of the four loops coupled to the central arbiter. In descending order of priority, access to the shared facility is granted to loop L, loop M or loop N. Thus, the central arbiter is capable of granting access to only one loop at a time in reply to all of the pending loop access requests at a given moment in time. Once the access granted signal is transmitted back to the loop arbiter and access has been completed, the request from the requesting loop is withdrawn. Accordingly, if a request had been pending from loop K, the level on line 238 would have been high. However, once the request has been satisfied, the level on line 238 goes low because the loop controller withdraws the request in line MARLK thereby resetting JK flip flop 208 thus causing the output on line 262 to go high. This condition then permits any of the other loops to gain access to the shared facility provided one of the JK flip flops 210, 212, or 214 is set. Subsequent access to the shared facility, however, will continue to be granted to the other loops on the basis of the priority established by the circuitry of FIG. 4.
As will become clear from an investigation of FIG. 4, once all of the access requests which were previously latched by the JK flip flops 208, 210, 212 and 214 have been satisfied, the circuitry of FIG. 4 returns to a free mode of operation which permits the first access request received thereafter from any of the loops to initiate a new clock pulse on line 218 causing all requests appearing at the central arbiter at that time to be latched by the JK flip flops 208, 210, 212 and 214. Thereafter, these access requests are processed in the manner described above.
The foregoing description of the invention has made particular reference to the embodiment of the invention illustrated in the drawings. Those skilled in the art will readily recognize variations to the circuitry which may be employed to accomplish somewhat different functional requirements. An example of such a requirement becomes clear when the number of units which require access to a shared facility becomes vary large. The embodiment of a two level bus access arbiter network, as detailed herein, is quite efficient in both hardware utilization and arbitration delay time because the serial arbiter loops are small (4 units) and the complexity of the parallel arbiter is minimized. The two level embodiment falls short of these objectives when the number of units requiring access to a shared facility exceeds 32. With 32 units the loop size is eight and the arbitration time thus increases correspondingly to approximately 130 ns. Alternately, one may choose to increase the parallel arbiter to 8 inputs thus resulting in higher logic complexity and again a corresponding increase in arbitration time.
Optimization of arbiter networks properties for large numbers of units requiring access to a shared facility is accomplished through the use of multiple levels (>2) of serial arbiter loops. By referring to FIGS. 2 and 3, it is readily seen that multiple levels of serial arbiters may be interconnected wherein the request input RQSTO to serial arbiters below the first level is replaced by the MARL output of a serial arbiter at a level above it and wherein the loop grant signal MAGL input is replaced by an AEφ output of a serial arbiter at the next lower level.
A simplified block diagram of such a network is given in FIG. 5 wherein:
N=number of arbiter levels
U=total number of units requiring access to a shared facility
i k =request inputs per loop at level k
l k =number of loops at level k
l k >l k+1
l n =1 and ##EQU1## Example: If the total number of units (U) which require access to a shared facility is 256, let n=4 and:
i 1 =4, l 1 =64
i 2 =4 l 2 =16
i 3 =4 l 3 =4
i 4 =4 l 4 =1
Level 1 would thus be 64 loops of 4 unit inputs each, etc. Level 4 would consist of a single four input parallel arbiter.
Note that the serial arbiter employed in levels below Level 1 is modified so that the AEφ signal output is not bussed. Instead, each AEφ acts as a grant signal (MAGL) for a loop at the next higher level.
Such modification of the circuits illustrated can easily be made by those skilled in the art without departing from the spirit and scope of the invention.
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A multi-level arbiter for resolving multiple requests for access to a shared facility. The arbiter includes a plurality of loop arbiters, each including a polling circuit to test each of a plurality of units for a request for access to the shared facility. The first unit encountered by the polling circuit on each loop which has a request for service active is conditioned to utilize the shared facility as soon as the central arbiter grants the request for service to the loop. The central arbiter assigns priority among the loop arbiters.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the benefit of U.S. provisional patent application No. 60/574,232, filed on 26 May 2004, the entire contents of which is hereby incorporated by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to disposable piping bags as defined in the preamble to claim 1 , and more specifically to disposable piping bags used for the handling of foodstuffs.
BACKGROUND ART
[0003] Piping bags are mainly used for decorating pastries, confectionery or food with a viscous, semi-liquid or semi-fluid paste, such as whipped cream, marzipan, dough, cream cheese, sugar paste or the like. Piping bags can also be used for other purposes, for example for the application of glue, cement, plaster, moulding compound or the like.
[0004] A disposable piping bag is shown in U.S. Pat. No. 3,157,312. This piping bag consists of a plastic bag, formed from two layers of polymer film, which have been welded together along the edges of the bag. The piping bag is adapted, at one of its corners, to receive an essentially conical nozzle, through which a paste contained in the piping bag can be discharged. The nozzle can be provided with a selected profile, so that the extruded paste string can be given the desired appearance.
[0005] A problem associated with prior art disposable piping bags is that the piping bag can be difficult to handle both during manufacturing and in connection with the dispensing operation.
[0006] Therefore, there is a need for an improved disposable piping bag.
SUMMARY OF THE INVENTION
[0007] An object of the present invention is to provide a disposable piping bag, which reduces or eliminates the problems associated with prior art.
[0008] The object is achieved by a piping bag, a blank and a method according to the respective appended independent claims. Embodiments are defined in the appended dependent claims as well as in the following description and drawings.
[0009] According to a first aspect, a disposable piping bag is thus provided, comprising a container of polymer film. The piping bag is characterised in that it is formed essentially from a thin-walled polymer tube, and that an outwardly oriented surface of the piping bag is provided with a surface structure.
[0010] Disposable here means that the piping bag is to be discarded after use, and not cleaned and used again. However, this does not exclude that the piping bag is filled again and/or cleaned and, thus, used to spread more than one batch of flowable paste. In fact, disposable means that it must be possible to manufacture the piping bag in large quantities at a very low cost.
[0011] Surface structure here means the three-dimensional structure of the surface.
[0012] The surface structure of the piping bag reduces the risk of it slipping from the user's grip, especially if the user's hand, which may be fitted with a glove, is wet or smeared with, for example, oil or grease. Moreover, it is possible to provide a piping bag that is easy to grip without the addition of any friction-enhancing agent. Even if a friction-enhancing agent has been added, a surface structure may be advantageous because it creates a space between two abutting layers of polymer tube or piping bags, said space eliminating or reducing the risk of the layers adhering to one another, which would make handling more difficult.
[0013] According to a second aspect, a blank is provided for manufacturing at least two disposable piping bags, each comprising a container of polymer film. The blank is characterised in that it consists of an elongated thin-walled polymer tube, the piping bags being detachable from one another by means of severance marks, and that an outwardly oriented surface of the thin-walled polymer tube is provided with a surface structure.
[0014] According to a third aspect, a method is provided for manufacturing a disposable piping bag, comprising a container of polymer film. The method comprises forming the piping bag essentially from a thin-walled polymer tube, and providing an outwardly oriented surface of the thin-walled polymer tube with a surface structure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a schematic perspective view of a piping bag.
[0016] FIG. 2 is a schematic plan view of the piping bag in FIG. 1 .
[0017] FIG. 3 is a perspective view illustrating the step of rolling a polymer tube to form the piping bag in FIG. 1 .
[0018] FIG. 4 is a plan view of a blank for forming the piping bag in FIG. 1 .
[0019] FIG. 5 illustrates a first example of a surface structure.
[0020] FIG. 6 illustrates a second example of a surface structure.
[0021] FIG. 7 illustrates a third example of a surface structure.
[0022] FIG. 8 illustrates a fourth example of a surface structure.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0023] FIG. 1 shows a piping bag 1 , which at a dispensing orifice 5 is provided with a nozzle 2 and which through an open end 4 has been filled with a flowable paste 3 . The flowable paste 3 is dispensable through the nozzle 2 when the open end 4 of the piping bag 1 is closed, for example folded, and the piping bag 1 compressed.
[0024] With reference to FIG. 2 , the piping bag 1 is formed from a polymer tube segment, preferably of polyolefin plastic, such as polyethylene, polypropelene or the like. When unfilled, as shown in FIG. 2 , the piping bag 1 has an essentially two-dimensional extension, its shape being defined by two parallel creases at the edges 9 , 10 , formed by the polymer tube being collapsed, and a joint 7 that is obliquely transversal to the edges 9 , 10 . A severance mark 8 runs parallel to the joint 7 , which mark 8 is achieved in a manner obvious to a person skilled in the art, for example by means of perforation. At the open end 4 of the piping bag 1 , a severance mark 11 extends perpendicularly to the edges 9 , 10 . At the open end, a weaker welding joint (not shown) may be provided, which is such that upon tearing along the severance mark 11 , the piping bag remains closed until a user deliberately opens it. According to one embodiment, this weaker welding joint can be achieved at a low temperature and under mechanical pressure.
[0025] To enable dispensing by means of the piping bag 1 , it is cut at the cutting line K, so that an orifice 5 of a desired size is obtained. In the orifice, the nozzle 2 can be applied or, alternatively, the piping bag can be used without a nozzle.
[0026] FIG. 3 shows how a polymer tube 21 for manufacturing piping bags is collapsed by it being caused to travel through rollers 20 to form an essentially two-dimensional elongate blank 22 with double layers. The skilled person is familiar with forming a polymer tube through film blowing.
[0027] FIG. 4 shows how the double layer blank 22 has been provided with oblique welding joints 7 and severance marks 8 , 11 for the purpose of defining piping bags 31 , 31 ′.
[0028] The piping bag can be essentially transparent, i.e. transparent to such a degree that its contents are visible through the limiting surfaces of the piping bag. According to one embodiment, the piping bag may be tinted.
[0029] An outwardly oriented surface of the piping bag 1 is provided with a surface structure, which improves the grip, i.e. its roughness increases the friction between the user's hand and the piping bag.
[0030] FIG. 5 illustrates a first example of a grip-enhancing surface structure, which can be achieved by adding grains and/or flakes to the polymer pulp before the film blowing to form the polymer tube is carried out, or in connection therewith. It will be appreciated that grains and/or flakes can also be applied to the surface of the plastic tube after the tube 21 or the blank 22 is formed. The grains or flakes may, for example, be of a plastic material having a higher density and/or melting point than the material of which the polymer tube is formed. For example, the polymer tube may be made of low-density polyethylene (PE-LD), the grains or flakes being made of high-density polyethylene (PE-HD) or of polypropylene. According to other embodiments, the grains or flakes may consist of sawdust, fine sand, lime and/or solid or hollow micro glass spheres.
[0031] Another way of achieving a surface similar to that shown in FIG. 5 is to apply a lacquer to the outside of the piping bag, which lacquer is provided with a surface structure-forming additive, for example additives of the kind described above.
[0032] FIG. 6 illustrates a second example of a grip-enhancing surface structure, which can be achieved by rolling the polymer tube 21 , for example as shown in FIG. 3 , through an embossed roll, if necessary under the influence of heat, which allows the polymer tube to be provided with, for example, a granular ( FIG. 6 ) or grooved (not shown) structure.
[0033] According to one embodiment, the polymer tube can be made of at least two laminated polymer material layers. A polymer tube of this kind may have a plurality of layers having different functions, for instance an inner layer intended to facilitate the feeding of flowable paste and prevent said paste from adhering to the inner walls of the piping bag and intended to facilitate the introduction of the nozzle 2 ; a gas-tight layer, a supporting layer and/or an outer grip-enhancing layer. It is obvious to the skilled person how to obtain a laminated polymer tube by simultaneous extrusion and film blowing of inner and outer layers. Another prior-art manner of obtaining a laminated plastic film is to join two film layers using, for example, and adhesive and/or heating.
[0034] The above methods of providing a grip-enhancing surface structure can be used both in one-layer piping bags and in laminated piping bags. The surface structure described with reference to FIG. 5 is highly suitable for laminated piping bags, since it is sufficient to add grains or flakes to the material forming the outer layer of the polymer tube.
[0035] FIG. 7 illustrates a further example of a grip-enhancing surface structure, which can be achieved by adding an expanding agent to the material of which an outer layer of a laminated polymer tube is formed. The skilled person is familiar with the art of expanding. By exposing, after film blowing, the polymer tube 21 to heat the expanding agent is caused to release a gas, bubbles being formed in the outer surface of the polymer tube, which bubbles burst, thus creating a rough surface the structure of which may be of the kind shown in FIG. 7 . Non-limiting examples of expanding agents are bicarbonate, AZO-dicarbonate amide and water.
[0036] Yet another example of a grip-enhancing surface structure is shown in FIG. 8 and can be achieved by means of starve-feeding. Starve-feeding can be done using pure plastic or with a filler additive, such as silicates, chalk, carbonates, small glass beads, fine sand, etc, which is added to the material of which an outer layer of a polymer tube is formed. The skilled person is familiar with the process of starve-feeding. The extrusion apparatus used to feed the outer layer material is starve-fed, which results in a surface structure similar to that of FIG. 7 being obtained. In this case, the concentration and friction of the filler can be varied to obtain the desired surface roughness.
[0037] A further example of a grip-enhancing surface structure similar to those shown in FIG. 7 or FIG. 8 can be achieved by means of cold-feeding, wherein the outer layer is starve-fed and the extruder is operated at a lower temperature than normal. In this case, no filler is needed. The skilled person is familiar with the art of cold-feeding.
[0038] The ways of achieving a grip-enhancing surface structure described above may also be combined with the addition of known friction-enhancing agents, for example viscous high-molecular liquids such as polyisobutylene and/or glycerol esters.
[0039] According to one embodiment, the surface structure described with reference to FIG. 5 is combined with the surface structure described with reference to FIG. 7 or FIG. 8 . This embodiment can also be combined with the surface structure described with reference to FIG. 6 , and/or a friction-enhancing agent.
[0040] According to another embodiment, the surface structure described with reference to FIG. 7 or FIG. 8 is combined with the surface structure described with reference to FIG. 6 . This embodiment can possibly be combined with a friction-enhancing agent.
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Example embodiments relate to a disposable piping bag, having a container of polymer film. The piping bag may be made essentially from a thin-walled polymer tube, and an outwardly oriented surface of the piping bag may be provided with a rough surface structure. The rough surface structure may have the form of a pattern of raised dots or grooves presenting a surface friction coefficient which may be higher than that of the polymer film.
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TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method and apparatus for reducing nozzle failure in printheads that have been stored or otherwise unused for extended periods.
BACKGROUND OF THE INVENTION
Most inkjet printers dispense colorants or inks that are comprised of a dye and/or a pigment that is either dissolved or suspended in a volatile solvent. When the print head of the printer deposits the colorants on a recording media such as paper or film, the solvents in the colorants quickly evaporate, leaving the dyes and/or pigments behind on the recording media.
During the manufacturing process printheads for inkjet printers must be tested. Accordingly, it is customary to provide an inkjet printhead with a dye and/or pigment based colorant that will be dispensed from the printhead as a test to ensure that the printhead functions properly. It may also be necessary to include a colorant with a printhead so that a printer in which the printhead is installed may be tested.
However, where colorants are allowed to remain in a printhead for extended periods of time, it is often the case that the volatile solvents that make up the colorants will at least partially evaporate, leaving within the nozzles of the print head a residue of particles or a precipitate. FIGS. 1 a - 1 c illustrate how the evaporation of a volatile solvent from the colorant can result in the malfunction of the printhead.
FIG. 1 a is a schematic view of a typical nozzle 12 in an inkjet printhead 10 . As will be readily understood by those skilled in the art, a printhead 10 typically includes multiple nozzles 12 , each of which is connected to a reservoir (not shown) by a conduit 14 . Generally, a single conduit 14 will supply colorant 13 to multiple nozzles 12 . In a thermal inkjet printhead, a small resistor 16 will be provided adjacent to the opening of the nozzle 12 . The resistor 16 ejects colorant 13 from the nozzle 12 by rapidly raising the temperature of the colorant 13 so as to cause the solvent thereof to boil. The rapid expansion of the boiling solvent ejects a droplet (not shown) of colorant 13 from the opening of the nozzle 12 in a known manner. Other types of inkjet printheads may utilize a piezoelectric element in lieu of the resistor 16 .
The printhead 10 illustrated in FIG. 1 a represents a printhead that has been newly filled with the colorant 13 . FIG. 1 b , represents a printhead 10 that has been stored for a period of time. Over time the solvents present in the colorant 13 begin to evaporate as represented by arrows 18 . The evaporation of the solvents from the colorant 13 concentrates the pigments and/or dyes present in the colorant 13 . As more time passes, the pigments and/or dyes begin to form a solid accretion 2 . As can be seen in FIG. 1 c , the accretion 2 has grown to the point where it blocks the nozzle 12 , thereby preventing its proper functioning.
In order to retard the evaporation of the solvents from a colorant, it is common to either cover the nozzles of a printhead with tape or else to ensure that the printhead is otherwise covered with a cap. While such methods do slow the evaporation of solvents from the colorant, simply covering a nozzle is not sufficient to prevent the formation of accretions in a nozzle where the printhead is placed in storage for an extended period of time. Accordingly, there is a recognized need for a method and/or and apparatus that will prevent the formation of accretions in the nozzles of the printhead, particularly where the printhead must be stored for extended periods of time either before it is used or between uses.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 a - 1 c are a schematic time-lapse depiction of a prior art printhead wherein solvents in a colorant evaporate to form an accretion in a nozzle;
FIG. 2 is a schematic representation of an exemplary printhead having a low concentration colorant inserted into a nozzle according to the present invention;
FIG. 3 is a schematic representation of an exemplary printhead and colorant supply system for operating a printhead such as that illustrated in FIG. 2 ; and,
FIG. 4 is a schematic representation of an exemplary printhead such as that illustrated in FIG. 2 and further including an exemplary nozzle priming system.
DETAILED DESCRIPTION
In the following detailed description, reference is made to the accompanying drawings that form a part hereof, and in which is shown, by way of illustration, exemplary embodiments in which the invention may be practiced. In the drawings, like numerals describe substantially similar components throughout the several views. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. Other embodiments may be utilized and structural, logical, and electrical changes may be made without departing from the scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims and equivalents thereof.
FIG. 2 is a schematic representation of an exemplary printhead 20 having a single nozzle 22 formed therein. Note that in practice, inkjet printhead 20 would have multiple nozzles 22 . However, for the sake of clarity, this description will demonstrate a printhead having only a single nozzle.
Colorants are supplied to the nozzle 22 through a conduit 24 . The conduit 24 is fluidically connected to a reservoir (not shown) that provides a continuous supply of a colorant 26 . While the exemplary methods and apparatuses herein may apply to any printhead or printing mechanism that utilizes a colorant 26 that comprises a volatile solvent, this description focuses on an exemplary thermal inkjet printhead embodiment. A resistor 28 is electrically connected to a controller via conductor 30 . The controller (not shown) applies a current to the resistor 28 , which boils the solvent in the colorant 26 immediately adjacent to the resistor 28 . The boiling of the solvents creates a vapor bubble whose expansion ejects a droplet of the colorant 26 from the nozzle 22 so as to form an image on a recording media (not shown).
Because it may be necessary to test the printhead 20 after its manufacture, or test a printer (not shown) in which the printhead 20 has been installed, a first, dilute colorant 26 a is inserted into the printhead 20 so as to substantially fill the nozzle 22 . Note that the first colorant 26 a must fill that portion of the nozzle 22 immediately adjacent to its opening. The first colorant 26 a may also fill some portion of or the entire conduit 24 as well. Preferably, a second, more concentrated colorant 26 b is placed in a reservoir 32 (see FIG. 3 ) and reserved separately therein. However, in certain applications, the second colorant 26 b may be injected into the conduit 24 of the printhead 20 after the first colorant 26 a has been inserted therein.
It has been found that the number of malfunctioning nozzles 22 present in a printhead 20 is directly related to both the concentration of the colorant 26 and to the length of time that the printhead 20 is in storage. Accordingly, the insertion of a first, more dilute colorant 26 a directly into the nozzle 22 adjacent the opening thereof results in fewer malfunctioning nozzles 22 over a given period of time. Thus, as the solvents in the first colorant 26 a will likely continue to evaporate, the lower concentration of dyes and/or pigments in the first colorant 26 a results in the slower growth of accretions in the opening of the nozzle 22 .
In certain embodiments, the first colorant 26 a is simply a more dilute version of the more concentrated second colorant 26 b . Once the printhead 20 has been manufactured, the first colorant 26 a is inserted through the conduit 24 into the nozzle 22 . The second colorant 26 b is then injected into the reservoir 32 . While the concentration of dyes and/or pigments in the first colorant 26 a is lower than that of the second colorant 26 b , the concentration is sufficient to allow the printhead 20 to be tested, as is commonly the practice, and yet yields fewer malfunctioning nozzles 22 after storage of the printhead 20 for a given period of time.
In certain other embodiments, the second colorant 26 b is inserted into the printhead 20 at least part way into the conduit 24 but possibly also partly into the nozzle 22 , keeping in mind that the first colorant 26 a is to occupy the majority of the nozzle 22 , and possibly all of the nozzle 22 . Note that the dimensions of the conduit 24 in the nozzle 22 are such that the colorants 26 a and 26 b will not be significantly mixed together. Accordingly, it is possible for colorants 26 a and 26 b , differing only in their concentration is of dyes and/or pigments, to coexist side-by-side for extended periods of time without any significant mixing.
In some instances it may be preferable to utilize dissimilar colorants 26 a and 26 b . As used herein, the term “dissimilar” should be taken to include colorants 26 comprising different combinations and concentrations of solvents, and coloring agents such as dyes and/or pigments. By way of example only, in some instances it may be desirable to utilize a colorant 26 a that has a different hue, or for that matter a completely different color, than the colorant 26 b . To further prevent mixing of the colorants 26 a , 26 b it may be desirable to select solvents for the respective colorants that are dissimilar or even immiscible with one another. Alternatively, it may be desirable to select a solvent or mixture of solvents for use in the colorant 26 a that have a relatively low volatility.
FIG. 3 illustrates an apparatus for implementing the present invention. In this embodiment, nozzles 22 are formed in a nozzle orifice plate 23 . Colorant is supplied to the nozzles 22 in the nozzle orifice plates 23 through a conduit 24 . As can be seen in FIG. 3 , the conduit 24 may be sized so as to include a modicum of storage place for colorants 26 . The conduit 24 is fluidically connected to a colorant delivery system 31 . The colorant delivery system 31 includes a colorant supply reservoir 32 that is connected to the conduit 24 by a line 33 that passes through a pump 34 and a valve 36 . Note that in some embodiments the colorant delivery system 31 may be located remotely from the printhead 20 . In other embodiments, the ink delivery system 31 may be formed as an integral part of the printhead 20 . It is to be understood therefore that line 33 is to be construed to include any coupling mechanism for connecting the reservoir 32 to the conduit 24 .
During normal operation, pump 34 is actuated to move colorant from the reservoir 32 through the line 33 into the conduit 24 . The valve 36 may be operated to selectively open and close the line 33 , thereby permitting or preventing, as the case may be, the flow of colorant from the reservoir 32 into the conduit 24 . The colorant 26 flows through the conduit 20 either due to the force of gravity or as the pump 34 has pressurized the colorant 26 in the conduit 24 .
As part of the manufacturing process, or as part of a “mothballing” procedure, the apparatus illustrated in FIG. 3 will have a predetermined quantity of the first colorant 26 a inserted into the conduit 24 as represented by fill line 27 . The amount of the first colorant 26 a inserted into the conduit 24 is sufficient to allow one or more required tests of the printhead 20 and to ensure that the nozzles 22 remain substantially filled with the first colorant 26 a . A port or other access point (not shown) may be provided in the printhead 20 so as to allow the injection of a quantity of the first colorant 26 a into the conduit 24 at the time of manufacture or later, after the printhead 20 has been installed in a printer. Such port or other access point may then be closed in some manner.
In certain exemplary embodiments, multiple reservoirs 32 may be used. In the illustrated embodiment, the printhead 20 is prepared for printing an image on recording media by actuating the colorant delivery system 31 to withdraw the first colorant 26 a from the printhead 20 and into a first reservoir 32 . Once the first colorant 26 a has been removed from the printhead 20 , the reservoir 32 containing the first colorant 26 a is uncoupled from the colorant delivery system 31 and a second reservoir 32 , this one having the second colorant 26 b contained therein, is coupled to the colorant delivery system 31 . The colorant delivery system 31 is then actuated to provide the second colorant 26 b to the printhead 20 for printing. The first colorant 26 a may be conserved in the first reservoir 32 or may be discarded. Where it is desirable to “mothball” the printhead 20 , the colorant delivery system 31 may be actuated to withdraw the second colorant 26 b from the printhead 20 back into its reservoir 32 for conservation. Thereafter, the first colorant 26 a may be reintroduced into the printhead 20 by coupling a reservoir 32 having the first colorant 26 a contained therein to the colorant delivery system 31 . The colorant delivery system 31 will then be actuated to reintroduce the first colorant 26 a into the printhead 20 .
The nozzles 22 of the printhead 20 may be closed as by capping or taping and as seems appropriate given the application to which the printhead 20 will be put. The printhead 20 may then be placed into storage or otherwise inactivated. Note that the printhead 20 may be detached from the line 33 and stored apart from the reservoir 32 , pump 34 and valve 36 , may be installed in a printer along with the reservoir 32 , pump 34 , and valve 36 for storage, or a combination of the reservoir 32 , pump 34 and valve 36 may be stored together with the printhead 20 in an integral package. For the purposes of the present application, the term “storage” should be taken to mean the reservation of the printhead 20 at a location remote from a printer or an extended period of inactivity where the printhead 20 is installed in a printer. The second colorant 26 b may be retained entirely within the reservoir 32 , leaving only the first colorant 26 a in the conduit 24 . Alternatively, the second colorant 26 b can be inserted into the conduit 24 behind and up to the first colorant 26 a up to line 27 as shown in FIG. 3 .
Where the printhead 20 is currently in use but is to undergo a period of prolonged in activity, a mothballing procedure may be performed upon the printhead 20 . During such a procedure, relatively concentrated colorant 26 b present in the conduit 24 and nozzles 22 is either ejected or is withdrawn into the reservoir 32 by means of the pumping action of the pump 34 through line 33 . Thereafter, dilute colorant 26 a may be inserted into the conduit 24 through the aforementioned port so as to substantially fill the nozzles 22 . In an alternate embodiment, and as it is likely that some quantity of concentrated colorants 26 b may be retained within the conduit 24 and nozzles 22 , a compatible solvent not having a dye and/or pigments included therein may be inserted into the conduit 24 to be mixed with the second colorant 26 b remaining in the conduit 24 by means of pulsing the pump 34 as described herein above. Alternatively, the pure solvents added to the conduit 24 may be drawn through the conduit 24 and expelled from the nozzles 22 by the normal operation of the nozzles 22 , the nozzles 22 being operated so as to draw sufficient quantities of the pure solvents into the nozzles 22 to reduce the incidence of malfunction in the nozzles 22 when the printhead 20 is installed and/or reactivated.
Upon installation of the printhead 20 in a printer, or upon reactivation of the printhead 20 in a printer, printing of an image upon recording media may commence using the first colorant 26 a . The use of a dilute mixture of the second colorant 26 b as the first colorant 26 a may allow the printhead 20 to begin printing in such a way as to produce images of an acceptable quality where the color, hue, and/or intensity of the first colorant 26 a is near enough to satisfy the image quality requirements expected of images printed using the second colorant 26 b . Alternatively, one or more test images or patterns may be printed for the express purpose of exhausting the supply of the first colorant 26 a within the printhead 20 prior to the start of printing using the desired second colorant 26 b.
The apparatus illustrated in FIG. 3 may also be operated in such a way as to mix the first and second colorants 26 a , 26 b prior to the start of printing by the printhead 20 . In this embodiment, the first colorant 26 a is a dilute version of the second colorant 26 b . Upon installation of the printhead 20 in a printer, or upon reactivation of the printhead 20 after a period of inactivity, valve 36 is opened and pump 34 is operated so as to alternatively pump the second colorant 26 b from the reservoir 32 into the conduit 24 and to withdraw the first colorant 26 a from the conduit 24 into the reservoir 32 , thereby effectively mixing the first and second colorants 26 a and 26 b . In order to ensure that the colorant 26 used to print an image on a recording media retains a desired color intensity, the second colorant 26 b contained within the reservoir 32 may be highly concentrated or the reservoir 32 may be over-filled, the concentration and/or volume of the second colorant 26 b being such that the addition of a quantity of the dilute first colorant 26 a does not significantly affect desired colorant properties such as intensity, hue, or the like.
FIG. 4 illustrates another exemplary embodiment that includes a colorant delivery system 31 , a printhead 20 , and a nozzle priming system 40 . As described above, the ink delivery system 31 includes a reservoir 32 that is fluidically coupled to the conduit 24 of the printhead 20 by means of line 33 . While in the embodiment illustrated in FIG. 4 , no pump or valve has been included in line 33 , such may be added where warranted by the application under consideration. The nozzles 22 of the printhead 20 are included in the nozzle orifice plate 23 . See FIG. 3 . As illustrated, the printhead 20 is filled up to fill line 27 with a first colorant 26 a . While FIG. 4 does illustrate that the conduit 24 is at least partially filled with the first colorant 26 a , it must be kept in mind that all that is required is that the nozzles of the nozzle orifice plate 23 be partially or substantially filled with the dilute, first colorant 26 a . The more concentrated second colorant 26 b is contained within the reservoir 32 of the ink delivery system 31 and is supplied, upon demand, to the printhead 20 through line 33 . The nozzle priming system 40 comprises a priming cap 42 that is constructed and arranged to fit snugly over the nozzle orifice plate 23 , preferably forming a seal thereover. The priming cap 42 is connected through a pump 44 to a priming reservoir 46 by means of line 48 .
In operation, the printhead 20 is first installed in a printer or is reactivated after a period of inactivity; pump 44 is actuated to draw the first colorant 26 a from the nozzle orifice plate 23 and conduit 24 of the printhead 20 and into the priming cap 42 . The first colorant 26 a is then deposited into the priming reservoir 46 . In this embodiment, once the first colorant 26 a is removed from the printhead 20 and deposited in the priming reservoir 46 , it will not be reused. It is to be understood however that the first colorant 26 a may be reused where so desired.
As the first colorant 26 a is drawn from the printhead 20 , the action of the pump 44 will simultaneously draw the second colorant 26 b from the reservoir 32 into the condiut 24 and subsequently into the nozzles of the nozzle orifice plate 23 . At this point, the printhead 20 is ready to begin printing an image using the second colorant 26 b.
Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that any arrangement that is calculated to achieve the same purpose may be substituted for the specific embodiments shown. Many adaptations of the invention will be apparent to those of ordinary skill in the art. Accordingly, this application is intended to cover any adaptations or variations of the invention. It is manifestly intended that this invention be limited only by the following claims and equivalents thereof.
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An inkjet printhead and a method for increasing the shelf life thereof are herein disclosed. The inkjet printhead has one or more nozzles for dispensing a colorant. These nozzles are fluidically connected to a reservoir. A first colorant substantially fills the nozzles while a second colorant is reserved in the reservoir.
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BACKGROUND OF THE INVENTION
The present invention relates to apparatus for purifying exhaust gases of internal combustion engines of automotive vehicles.
There are three kinds of catalytic converters, namely a reducing catalytic converter for elimination of nitrogen oxides, an oxidizing catalytic converter for elimination of carbon monoxide and hydrocarbons, and three-way converters for reacting the three noxious elements at the same time. The converters comprise a catalyst bed comprising a pellet type catalyst element or monolithic or honeycomb catalyst element. The monolithic catalyst element has a series of longitudinally oriented passages, so that exhaust gases may flow smoothly through the catalyst element. However, there is a problem that reaction may not be sufficiently carried out to reduce each noxious conponent to the required level because of short residence time of the gas flow.
Further, in the conventional catalytic converter the axial line of the inlet port is arranged to make a right angle with the front plane of the catalyst element at the central portion thereof. Although the inlet port communicates the catalyst element through the cone-shaped guide duct, the exhaust gas flow cannot sufficiently diffuse up to the entire front plane of the catalyst element and hence has a tendency to collect in the central portion of the front plane. Consequently, the central portion is heated at a high temperature resulting early in damage to the portion.
Therefore, it is the object of the present invention to provide a catalytic converter which may uniformly distribute the exhaust gases to the monolithic catalyst element, thereby achieving maximum reaction efficiency.
According to the present invention, a diffuser means is provided in the inlet chamber of the catalytic converter for distributing the exhaust gases uniformly to the monolithic catalyst element.
SUMMARY OF THE INVENTION
In accordance with the present invention, the apparatus comprises a pair of upstream exhaust pipes, a catalytic converter communicating with to the exhaust pipes, and a downstream exhaust pipe communicating with to the catalytic converter. The catalytic converter comprises a cylindrical shell comprising a pair of half shells for defining an inlet chamber and a catalyst chamber and outlet chamber, the monolithic catalyst element being resiliently mounted in the catalyst chamber. The inlet chamber has two inlet ports which are communicate with to the upstream exhaust pipes, respectively, and the outlet chamber has an outlet port communicating with to the downstream exhaust pipe. The two inlet ports are disposed in such that the axial lines of the inlet ports cross each other in the inlet chamber at a portion in front of the catalyst element. A diffuser means is provided in the inlet chamber for diffusing the exhaust gases in the inlet chamber, thereby uniformly distributing the gases to the monolithic catalyst element.
Other objects and advantages will be apparent as the present invention is hereinafter described in detail referring to the accompanying drawings, in which:
FIG. 1 is a plan view of an apparatus embodying the present invention,
FIG. 2 is a sectional plan view of the catalytic converter shown in FIG. 1,
FIG. 3 is a side view of the catalytic converter,
FIG. 4 is a perspective view of shells of the catalytic converter with the parts shown in disassembled relation,
FIG. 5 is a sectional view taken along the line V--V in FIG. 2,
FIG. 6 is a sectional view taken along the line VI--VI in FIG. 2,
FIG. 7 is a perspective view showing a diffuser, and
FIG. 8 is a sectional plan view of an inlet chamber portion.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, exhaust an system in which the catalytic converter of the present invention is applied comprises a bifurcated exhaust pipe comprising two upstream exhaust pipes 2 and 3 connected to a pair of exhaust ports of the engine 1 and a common downstream exhaust pipe 4. Such a bifurcated exhaust pipe, for example, is used in the horizontal opposed-cylinder type engine. At the concourse portion or bifurcation of the exhaust pipes, a catalytic converter 5 of the present invention is provided, connecting each end of the exhaust pipes 2 and 3 to an inlet of the catalytic converter and connecting the end of the common exhaust pipe 4 to an outlet thereof.
The catalytic converter 5 comprises a monolithic catalyst element 6 provided in a cylindrical shell 7 having an oval cross section and a protective cover 8, as shown in FIGS. 2 to 6. The catalyst is a monolithic three-way catalyst, but other types of catalyst may be used as the converter. The shell 7 comprises a pair of half shells 9 and 10 each of which is made by pressing stainless steel plate. Each of the half shells 9 and 10 has a body shell 11, a tapered inlet shell 12, and a tapered outlet shell 13. The inlet shell 12 has a pair of semicircular inlet portions 14 and 15, and the outlet shell 13 has a semicircular outlet portion 16. Thus, by joining both half shells 9 and 10 together, a catalyst chamber is formed by the body shells 11, an inlet chamber 17 is formed by the tapered inlet shells 12, and inlet ports 18 and 19 are formed by the semicircular inlet portions 14 and 15. Further, an outlet chamber 20 is formed by the tapered outlet shells 13 and an outlet port 21 is formed by the semicircular outlet portions 16. Each axial line of the inlet ports 18 and 19 forms an acute angle with the front end plane of the catalyst element, as shown in FIGS. 2 and 8, so that the axial lines of both inlet ports cross each other in the inlet chamber 17 at a central position near the front end of the catalyst element 6. Further, the outlet port 21 is biased from the axial line of the catalyst chamber and makes an angle with the axial line. The monolithic catalyst element 6 engages an annular rim 22 at the front end portion and a wire mesh 23 and damper meshes 24 and 25 are provided between the cylindrical shell 7 and the periphery of the rim and catalyst element. The damper mesh 24 is disposed between the shoulder 26 of the cylindrical shell 7 and the annular rim 22 and the damper mesh 25 is disposed between the shoulder 27 of the shell and the end of the catalyst element. Thus, the monolithic catalyst element 6 is resiliently maintained by the wire mesh 23 and damper meshes 24 and 25, so that movement of the catalyst emember is prevented. Further, the damper mesh 24 and the annular rim 22 serve as a sealing device for preventing the exhaust gases from passing through the space between the catalyst element the the inner wall of the shell 7.
The upstream exhaust pipes 2 and 3 engage the inlet ports 18 and 19 and are welded thereto, respectively and the downstream exhaust pipe 4 engages the outlet port 21. The converter shell 7 is covered by the protective cover 8 comprising half members 31 and 32. The half members 31 and 32 are joined at the portion surrounding the exhaust pipes 2, 3 and 4 and secured thereto by bolts 33. Peripheral edges of both half members 31 and 32 are disposed apart from each other and there a space 34 is provided between the cover 8 and the shell 7. Thus, air can enter the space 34 from the gap 35 between the edges of the half members 31 and 32, thereby cooling the converter during the operation.
In accordance with the present invention, there a reinforcement stud 36 is provided in the inlet chamber 17 and a diffuser 37 is secured to the stud. The stud 36 has reduced diameter portions 36a and shoulders 36b at the opposite ends. Each reduced diameter portion 36a engages a hole of the half shell 9 or 10 and the shoulder 36b supports the half shell, and the portion 36a and the half shell are welded each other. Thus, the half shells 9 and 10 may be assembled accurately into a cylindrical shell having a predetermined dimension. Further, the stud 36 is positioned at a point which is at some distance in the upstream direction from the crossing point of the axial lines of the inlet ports 18 and 19 as shown in FIG. 8.
The diffuser 37 has V-shaped cross section and comprises V-shaped diffusing plate 38. The diffuser 37 is arranged such that axial line of each inlet port makes an angle θ of incidence with the front plane of the diffusing plate 38, thereby deflecting the gas flow towards the side of the catalyst element far from the inlet port. The diffusing plate 38 has a plurality of perforations 39 and the total area of the perforations are determined so that about half the exhaust gases can pass through. Further, the diffusing plate has a height of about half the diameter of the gas flow passage, which is a preferable dimension for obtaining an effective diffusion of the gases with a small back pressure.
In operation, exhaust gases enter the inlet chamber 17 from the inlet ports 18 and 19 alternately in accordance with the firing order of the engine. About half the amount of the exhaust gases pass through the perforations 39 of the diffusing plate 38 and the remainder are deflected by the plate having an angle θ of incidence toward the peripheral area of the inlet chamber. Thus, the exhaust gases can be uniformly distributed to the catalyst element. In addition, since each axial line of the inlet ports makes an angle with the end plane of the catalyst element 6, the exhaust gases collide with the wall 40 of each passage of the catalyst element 6 as shown in FIG. 8. Therefore, the exhaust gases pass through each passage of the catalyst element in a zigzag flow pattern as shown by arrows in FIG. 8. The zigzag flow pattern increases the residence time of the gases in the catalyst element which enhances the catalytic reaction in the converter as compared with a conventional converter in which the gases pass straight through the passage.
Thus, in accordance with the present invention, the exhaust gases diffuse in the inlet chamber so as to be uniformly distributed to in the catalyst element and pass through the catalyst element at a reduced flow rate, whereby the reaction of the noxious components sufficiently takes place in the catalyst element to reduce the amount of the noxious components to the required level.
Further, the half shells 9 and 10 are supported in the desired position by the stud 36, whereby the cylindrical shell may be manufactured with accuracy and high rigidity.
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Apparatus for purifying the exhaust gases of internal combustion engines comprising a pair of upstream exhaust pipes, a catalytic converter, and a downstream exhaust pipe. The catalytic converter comprises a cylindrical shell having an inlet chamber, a catalyst chamber, an outlet chamber, and a monolithic catalyst element in the catalyst chamber. The inlet chamber has inlet ports communicating with the upstream exhaust pipes respectively and axial lines of the inlet ports cross each other in the inlet chamber. In the inlet chamber, a diffusion means is provided to diffuse the exhaust gas for uniformly distributing it to the catalyst element.
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RELATED APPLICATION
This application is a divisional application of U.S. patent application, Ser. No. 07/698,355, filed May 6, 1991, which issued as U.S. Pat. No. 5,116,363, which is a continuation-in-part of U.S. patent application Ser. No. 07/475,995, filed Feb. 6, 1990 now abandoned, which is a continuation-in-part of U.S. patent application, Ser. No. 07/410,093, filed Sep. 20, 1989 now abandoned and entitled METHOD AND APPARATUS FOR CONDITIONING REFUSE. Each of these three related applications are incorporated herein by reference.
BACKGROUND OF THE INVENTION
The invention relates to the disposal/treatment of refuse in the form of solid waste material, and more particularly to a method and apparatus for conditioning refuse by the noncombustible shrinking of polyfoam plastic material as one stage in the refuse disposal process.
Over the past 10 years, the quantity and character of household refuse and fast food refuse has changed measurably. The amount of trash generated has increased per person per day and the population has increased by some 30 million people. It is believed that the daily amount of trash for disposal in 1980 has increased by about forty percent (40%), while available disposal space has been decreasing.
The commingled household waste of today contains a very large percentage more of plastics and aluminum than household waste did 10 years ago. The methods for disposal include landfills, incineration and household separation of certain recyclable items with separate pickup for each item being necessary. All three methods are becoming increasingly expensive. In addition, it is very difficult to recycle recyclables in inner city trash by existing methods.
It is particularly desirable to have a method for disposing of and recycling certain municipal solid wastes both safely and economically and in a manner that does not harm the environment. Wastes from various sources including households, fast food restaurants and other commercial establishments including airports, sports arenas and other businesses contain cups and dishes made from polyfoam plastic material. The burning of such polyfoam plastics poses direct problems to the environment from the resulting exhaust gases. In addition, the dumping of such materials at land storage locations also effects the environment in that such plastics are not generally biodegradable and occupy an inordinately greater volume.
It is therefore an object of the present invention to optimize the recycling of certain municipal solid wastes safely and economically without harming the environment.
It is a further object of the present invention to provide a method and apparatus for the disposal of polyfoam plastic type material including foam cups, dishes and containers.
It is a further object of the present invention to provide a method and apparatus for preprocessing of polyfoam plastic materials such as foam cups and dishes in order to prepare the refuse for a subsequent sorting processes of recyclable and objectionable inorganics.
It is an additional object of the present invention to provide a conditioning stage in a waste disposal system which may be included within presently existing solid waste disposable facilities.
It is a further object of the present invention to optimize the recovery of aluminum, steel, plastic, glass, textiles and waste paper by treating the refuse before sorting.
It is an additional object of the present invention to have a method for shrinking polyfoam plastic materials, thus requiring far less volume for an eventual disposal site or for separation and recycling.
It is a further object of the present invention to shrink noncombustibly large volumes of polyfoam material quickly and safely in order to prepare the material for recycling.
SUMMARY OF THE INVENTION
These and other objects of the invention are achieved in a method and apparatus wherein refuse including polyfoam plastics is heated at a temperature of between 250° and 500° for a minimum period of time, causing non-combustible shrinking of the polyfoam plastics.
One of the disclosed embodiments causes the drying and sanitizing of the refuse stream in general, and the trash is separated with objects 6 inches and smaller being drawn off separately for easier recycling.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a flow diagram of a system using a preferred embodiment of the refuse conditioner of the present invention.
FIG. 2 is a partial side view of the refuse conditioner of FIG. 1.
FIG. 3 is a view taken along a section 3--3 of the conditioner of FIG. 2.
FIG. 4 is a front view of a nozzle ring of the conditioner of FIG. 2.
FIG. 5 is a side view of the nozzle ring of FIG. 4.
FIG. 6 is a side view of an injection tube of the conditioner of FIG. 2.
FIG. 7 is an end view taken along a section 7--7 of the conditioner of FIG. 2.
FIG. 8 is an enlarged side view of a portion of the injection tube of FIG. 6.
FIG. 9 is an enlarged end view of the injection tube of FIG. 6.
FIG. 10 is an end view of a drop out box of the conditioner of FIG. 2.
FIG. 11 is a side view of the conditioner of FIG. 1.
FIG. 12 is a view taken along section 12--12 of the conditioner of FIG. 11.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, municipal, commercial, household and/or fast food solid waste 11 is collected by a truck 13, or by other means. The waste is culled of large objects such as old appliances, hot water heaters, tree stumps, yard wastes, etc., and then dumped into a refuse inlet passage 15.
It is not necessary to presort raw refuse such that only polyfoam plastic materials enter inlet passage 15 The raw refuse in its "as is" unsorted state is fed into inlet passage 15. The input refuse is not shredded or otherwise processed prior to input. The present system is tolerant of handling all household wastes in addition to polyfoam plastics without harm to the environment. "Polyfoam plastic" as used herein shall mean plastic having gaseous bubbles randomly trapped within the plastic.
A rotating conditioning chamber 23 receives the solid waste from inlet passage 15 and heats the waste for rapid drying and shrinking of polyfoam plastic materials. Such items as foam cups and foam trays shrink to 1/5 of their initial size. The refuse moves through the conditioner chamber 23 at a rate which may be controlled in accordance with the moisture content of the trash.
A hot air heater 25 forces hot air gas (subsequently mixed with steam) into chamber 23. Air is drawn through a compressor 87 and is forced by the compressor into the hot air heater 25 and then forced into chamber 23. A steam boiler 24 develops steam and forces the steam through a superheater 28. Superheated steam leaves the superheater 28 and mixes with hot air passing from heater 25 within chamber 23. Hot air enters chamber 23 via a ring structure 45, discussed below with reference to FIG. 3. The superheated steam may either be mixed with the hot air or injected separately into chamber 23. If steam is injected separately, it may be done so by a nozzle(s) and the steam may be deflected into the center of the chamber by rotating flute elements 72, described hereinafter.
Boiler 24 can be fueled with unrecyclable waste paper for further efficiency, employing a conventional bag house 19 and a conventional ID (induced draft) fan 12 for pollution free operation.
Hot flue gasses from steam superheater 28 are split with some being recycled through duct 83 into chamber 23 with the balance exhausted to the atmosphere at 20.
The temperature of the gas at the inlet to chamber 23 will range from 250° F. to 550° F. The mixture of superheated steam and hot compressed air serves to kill bacteria inherent in the refuse in addition to shrinking and drying of the refuse. The steam will carry more BTU's of heat than the air, as understood.
Midway through the conditioning chamber 23, the refuse is exposed to a second stage reheater, generally indicated by reference numeral 29. Part of the air discharged from compressor 87 is heated to about 500° F. in a convection bank 22, merged with line steam and discharged back through line 89 to the second stage reheater 29 and into chamber 23.
Reheater 29 is formed from a distribution pipe 31 disposed along the longitudinal axis of chamber 23. Located on the outer surface of pipe 31 is a plurality of directional nozzles 33 through which the hot gas is discharged.
Chamber 23 rotates about its longitudinal axis tumbling the refuse and causing the refuse to move through the longitudinal length of the chamber. Distribution pipe 31 does not rotate with chamber 23.
Chamber 23 also contains a perforated inner liner 42. Liner 42 includes three inch holes 44, each spaced approximately five inches from their centers and covering the entire surface of liner 42. In addition, slots 46 (about 6 inches by 18 inches) are cut in liner 42 along the face of lifters 70 (described hereinafter in reference to FIG. 7). As chamber 23 rotates, materials 6 inches and smaller is scooped through the holes 44 and slots 46.
The refuse passes through chamber 23 and exits at an outlet 35 into a dropout box 37. The refuse cools rapidly and is conveyed by a mechanical conveyor 39, as for example moving belts, which can be used to convey the refuse to a mechanical classifier (not shown), or a hand picking line (not shown), where glass, ferric, aluminum, large plastic items, textiles and paper are sorted and sent to respective areas for recycling or disposal. The paper can further be separated into various classifications for baling and shipment or used for fuel for generating steam.
The small sized refuse that passes through inner liner 42 falls into grit box 20. Fine materials, such as food and other organics, grit, shrunken foam, shards of glass, etc., fall through a vibrating screen 48 or similar sorting device, and are then disposed of in a landfill or compost system. The larger items which fall into grit box 20 and do not pass through screen 48, such as soft drink cans, glass jars, shrunken plastic bottles, etc., move onto a moving belt 50. Belt 50 may form a picking line or transfer the items to a mechanical sorter for recovery and recycling of the items.
Referring now to FIG. 2, inlet passage 15 includes a slanted guideway 41 which leads into a rectangular entrance 43 of the chamber, shown more particularly in FIG. 3. A primary hot gas nozzle ring 45 is disposed at the entry end of chamber 23. As shown in FIGS. 3, 4 and 5, ring 45 is formed from a circular hollow pipe through which the hot air/steam gas is forced. A plurality of nozzles 47 communicate the interior of ring 45 with the interior of chamber 23. Hot gas is forced into ring 45 via a stem pipe 49 and then expelled through nozzles 47. The nozzles are directed facing into the rotating chamber from the front thereof.
As shown in FIG. 2, chamber 23 is supported above the ground or horizontal 50 by a plurality of support legs 55,57. As shown more particularly in FIGS. 11, 12, support legs 55,57 support bearing surfaces 51,53 on which the chamber rotates. In addition, drop out box 37 (FIG. 2) includes a circular bearing (not shown) which receives the chamber permitting its rotation relative to the drop out box. As shown in FIG. 12, legs 55, 57 include rollers 52,54 which turn relative to the legs during rotation of the chamber.
A motor assembly 65 is secured to the horizontal 50 and engages a sprocket gear 64, positioned at the central portion of the rotating drum, for causing its continual rotation. As shown in FIG. 2, cylinder 23 is formed of an outer skin 32 and an inner skin 34, between which insulation 36 is disposed. Perforated inner liner 42 (FIG. 2) is positioned uniformly inside the conditioning chamber and extends into dropout box 37 and over the top of grit box 20. Refuse which does not fall through inner liner 42 exits the chamber into dropout box 37. Inner liner 42 rotates together with chamber 23.
As shown in FIG. 2, distribution pipe 31 is located along the longitudinal axis of chamber 23. Pipe 31 lies within the majority of the central portion 61 of drum 23 and extends through dropbox 37. As shown in FIG. 6, distribution pipe 31 includes a coupling end 67 and a wear end 69. A wearplate 71 is formed around the outer perimeter of tube 31 at the wear end 69.
As shown in FIG. 7, wear end 69 of tube 31 rotates within a support ring 73 which is fixed with respect to chamber 23 by four support arms 75,77,79,81. As chamber 23 rotates, support arms 75-81 and support ring 73 rotate relative to distribution pipe 31. As shown in FIGS. 8 and 9, directional nozzles 33 are positioned around the circumference of tube 31 for providing forced hot gas within chamber 23. End 69 of tube 31 is closed so that hot gas is forced only from nozzles 33.
Referring again to FIG. 7, a plurality of flute elements 83, formed of flat metal plates, are secured to the inner perforated liner of rotating drum 23 in an auger-type arrangement. Flute elements 83 serve to transport the refuse from entrance 43 of the chamber to its outlet 35. Flute elements 72 formed of flat metal plates (4 inches by 12 inches) are also located below the perforated liner 42 and attached to the inner skin 34, to convey the material out of the conditioner quickly. The flat plates 72 are positioned in an auger arrangement on the inner skin. Lifters 70 formed of flat metal plates (6 foot by 1 foot) are also mounted longitudinally in a staggered arrangement around the circumference of the perforated liner 42. Lifters 70 serve to lift and tumble the trash for better contact with the hot air/steam. Slots 46 are located at the base of the lifters 70 where the lifter meets the liner 42.
Drop out box 37 is located at the outlet of chamber 23. Waste is moved into the dropout box and falls by gravity into the bottom section thereof. Conveyor 39 is located at the bottom of dropout box 37 and serves to convey the removed refuse to the next processing section (not shown). The hot air gasses being forced through chamber 23 are led out of the top of drop out box 37 through steam superheater 28 (FIG. 1) to the hot air stack 11 to the atmosphere at 20 or to chamber 23 via duct 83.
Rotational controls 93, as shown in FIG. 1, are manually controllable by the operator for controlling the motor assembly 65 for establishing the rate at which chamber 23 rotates. The flutes within chamber 23 establish the rate at which refuse is generally moved through the chamber from its entrance to its exit ends. By changing the rate of rotation, the operator can establish the amount of time that the refuse is within rotating chamber 23 and, thus, the amount of time that heat is applied to the refuse. Where the refuse has a good deal of moisture, the operator can slow the rotating drum down to ensure that the refuse is properly treated. The polyfoam plastic materials move through chamber 23 in less than ten minutes. This may be slowed, as discussed, by the operator, but the heating time will generally be less than ten minutes.
From the above description it can be seen that refuse including household bags of trash are fed into rotating chamber 23. No attempt is made to shred the trash by mechanical or other means. Jets of hot air and superheated steam contact the refuse including bagged garbage and the bags may open or be disintegrated by the steam contact. Polystyrene and other polyfoam materials are shrunk in size by controlled convective heat. Material six inches and smaller is filtered out. Glass and plastics are contacted with superheated steam making their subsequent removal and sorting much easier and more sanitary.
While preferred embodiments of the invention have been described hereinabove, those of ordinary skill in the art will recognize that the embodiments may be modified and altered without departing from the central spirit and scope of the invention.
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A method and apparatus for treating refuse by non-combustibly shrinking polyfoam plastics in the refuse. The trash is heated at a temperature between 250° and 500° for a minimum period of time. A rotatable chamber heats the refuse and transports the refuse for the minimum period of time. An operator controls the rate of rotation of the chamber and thus the time of heating in accordance with the moisture content of the refuse. A steam/air mixture used as a heat medium serves to kill bacteria in the refuse in addition to shrinking and drying the refuse.
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TECHNICAL FIELD
The present invention relates to the field of the technology of detachable connections. It specifically relates to a coupling, particularly for joining a tool to a driving unit, comprising
(a) two coupling parts successively arranged in a coupling axis and which have two facing contact surfaces at right angles to the coupling axis,
(b) within the first coupling part a clamping trunnion projecting from the first contact surface and substantially rotationally symmetrical to the coupling axis,
(c) within the second coupling part a reception bore for receiving the clamping trunnion and which emanates from the second contact surface and is located in the coupling axis in such a way that the two contact surfaces engage on one another when the clamping trunnion is completely inserted in the reception bore and
(d) a clamping device with at least one cylindrical clamping element, which with a conically tapering end in the vicinity of the reception bore and transversely to the coupling axis acts through the reception body on a clamping surface on the clamping trunnion and inclined with respect to the coupling axis and produces a clamping force acting in the direction of the coupling axis.
Such a coupling is e.g. known from European Patent EP-B1-141,451 in the form of a tool reception or mounting device and a matching tool carrier.
PRIOR ART
Couplings for the transfer of static or dynamic forces are known from the prior art in numerous different forms and with different operating principles. In the case of couplings operating with clamping forces, a distinction can be fundamentally made between two large groups, namely one group in which the clamping forces act radially to the coupling axis and another group in which the clamping forces act in the axial direction.
In the second group the axial forces can e.g. be produced by simply screwing together the two coupling parts, which is often cumbersome and time-consuming. Alternatively a bracing effect can be achieved by the lateral introduction of forces directed at right angles to the coupling axis and which are then deflected in the axial direction (wedge action).
In the case of couplings based on the latter principle and which are frequently used as so-called high-speed couplings, for the deflection of the clamping forces use is generally made of a clamping element with a conically tapering end, which acts on a clamping surface sloping with respect to the coupling axis.
Thus, e.g. U.S. Pat. No. 3,022,084 discloses a high-speed coupling for the connection of a tool holder and tool mounting device, which has a first coupling part with a first contact surface and a cylindrical clamp bolt projecting from said contact surface, as well as a second coupling part with a second contact surface and a corresponding bore for the reception of the clamp bolt. The clamping element is constituted by a locking screw with a conical screw end, which can be screwed transversely to the coupling axis through an associated tapped hole in the wall of the reception bore and in axially displaced manner engages in a correspondingly shaped, conical bore in the clamp bolt. As a result of the axial displacement between the locking screw and the conical bore, a force only acts on the latter on one side, the inclined wall thereof acting as a clamping surface, so that there is a resultant clamping force in the direction of the coupling axis. This force presses the two contact surfaces against one another with the desired initial load and consequently brings about a force closure between the two coupling parts, which is suitable for the transfer of static and dynamic forces.
In addition, e.g. CH-A5-656,335 discloses a drilling tool, which has a coupling with comparable contact surfaces. The clamping device is in this case in the form of two facing locking screws (retaining screws) with conically shaped ends, which act from two sides on a connecting bolt also with conical ends displaceably mounted at right angles to the coupling axis in the interior of the clamp bolt. Here again an axial displacement between the axes of the locking screws and the axis of the connecting bolt on screwing in said screws ensures a clamping force in the direction of the coupling axis.
Both coupling types suffer from the disadvantage that the elements essential for the clamping device such as the conical bore or the sliding connecting bolt must be very accurately machined, which leads to a relatively high manufacturing cost and due to the high costs involved the uses of such couplings are greatly restricted. However, it is particularly disadvantageous that the repeated insertion of the locking screws on the clamping trunnions can lead to impressions in the clamping surface, which are due to a plastic deformation and not only reduce the attainable clamping forces, but also prevent a reproducible setting of clearly defined initial loads.
Another, somewhat simplified coupling is disclosed in the first-mentioned document and once again a locking screw is used. The clamping surface is constituted by a surface milled on the clamp bolt and which is laterally bounded by a side inclined by approximately 45°. Here again it is in particular impossible to guarantee a reproducible initial loading of the coupling parts due to the aforementioned plastic deformation occurring in use.
DESCRIPTION OF THE INVENTION
The problem of the invention is to so further develop a coupling of the aforementioned type that it can be easily manufactured and simultaneously permits an easy, reproducible setting of the initial load.
In the case of a coupling of the aforementioned type this problem is solved in that
(e) at least the clamping trunnion is made from a surface-hardened material, preferably steel,
(f) the clamping surface is geometrically true with respect to the surface of the conical clamping element and
(g) the clamping surface is produced by cold extrusion prior to hardening.
The essence of the invention is that the clamping surface is produced in geometrically true manner by cold extrusion prior to the hardening of the coupling part by means of the clamping element or by means of another, comparable element with similarly shaped conical end. As a result of the cold extrusion and associated plastic deformation a homogeneous workhardening zone is produced below the impression or indentation and this locally increases the breaking and compressive strength or the hardness and wear resistance of the material.
On the one hand this ensures that without any further reworking stages the clamping surface is adapted in optimum manner to the conical end of the clamping element and the contact and therefore force transfer surface between the clamping element and the clamping surface is enlarged. On the other hand the workhardening zone below the impression ensures that during operation working takes place in the elastic range and no further plastic deformations occur, so that high initial loads can be reproducibly produced with short clamping paths.
A first preferred embodiment of the coupling according to the invention is characterized in that
(a) the clamping trunnion is provided with an all-round clamping groove, which on the side further removed from the first contact surface is laterally bounded by a first, inclined groove side and
(b) the clamping surface is located on the first groove side.
This embodiment has the advantage that the all-round groove can be formed by turning in the same operation used for producing the turned part, which obviates the need for a disadvantageous and costly resetting of the workpiece.
A second, preferred embodiment of the invention is characterized in that
(a) the clamping path to be covered by the clamping element during clamping is limited by a stop,
(b) the clamping trunnion is provided with an all-round clamping groove, which is laterally bounded by two sloping groove sides,
(c) the clamping surface is located on the first groove side further removed from the first contact surface and
(d) the second groove side serves as a stop for the clamping element.
As a result of the stop it is effectively ensured that the non-symmetrical bracing in the coupling resulting from one-sided clamping without any torque-limiting tool does not become so large that the concentricity suffers, whilst also avoiding that the clamping element is loaded beyond its limits.
The coupling according to the invention has a particularly simple construction if, according to another embodiment, the clamping element is constituted by a locking screw with a hexagonal recess which, due to the lever action, permits high initial loads to be produced with a simple hexagon socket wrench.
Coupling assembly is also greatly facilitated if, according to another preferred embodiment of the coupling, for the at least one clamping element is provided a plurality of similar clamping surfaces arranged in rotationally symmetrical manner around the coupling axis and means are provided for positioning the coupling parts relative to one another in such a way that selectively one of the clamping surfaces faces the clamping element in the position appropriate for clamping. This makes it possible to assemble the coupling virtually blind and in different positions, without the user having to specifically respect the correct association of clamping surface and clamping element.
Further embodiments can be gathered from the dependent claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is described in greater detail hereinafter relative to embodiments and the attached drawings, wherein show:
FIG. 1 a first, preferred embodiment for a first coupling part according to the invention with an all-round clamping groove in side view (a) and from the front (b).
FIG. 2 the second coupling part corresponding to FIG. 1 in side view (a) and from the front (b).
FIG. 3 details of the clamping groove of the coupling part according to FIG. 1 provided with the impression or indentation according to the invention and the cooperation with the clamping element (locking screw) in side view (a) and in plan view (b).
FIG. 4 the details of an embodiment corresponding to FIG. 3 with a clamping slot and clamp bolt in side view (a) and in plan view with the clamping surface (b) and additional stop surface (c).
FIG. 5 a view similar to FIG. 2b showing an alternate embodiment (a), another alternate embodiment (b), and yet alternate embodiment (c).
FIG. 6 a diagram of the clamping force K which can be produced over the number of load reversals N LW in the case of conventional couplings (curve cl) and with couplings according to the invention (curve c2).
FIG. 7 in longitudinal section (a) and in front view (b) a second coupling part with a positioning aid.
FIG. 8 in side view (a) and in front view (b) the first coupling part belonging to FIG. 7 with a plurality of clamping surfaces and a polygon as the positioning aid.
WAYS FOR PERFORMING THE INVENTION
The coupling according to the invention fundamentally comprises two coupling parts, which are engaged in a coupling axis and are initially loaded in the axial direction by means of a clamping device. A preferred embodiment for the first of said coupling parts is shown in side view in FIG. 1a and in front view in FIG. 1b.
The first coupling part 1 comprises an e.g. cylindrical central part 5, which has on one side a first, planar contact surface 4 perpendicular to the coupling axis 11. From the first contact surface 4 projects a clamping trunnion 2, which is substantially rotationally symmetrical to the coupling axis 11 and in which is worked an all-round clamping groove 3. The clamping groove 3 is bounded on both sides of a middle plane 8 by groove sides 7 and 9, which are chamfered with an angle of approximately 45° with respect to the coupling axis. The first groove side 7 forms the clamping surface on which the clamping element acts.
On the other side of the central part 5 is provided a device for fixing a tool and which in the example of FIG. 1 comprises a threaded connection 10. Obviously random other devices could be used in place of the threaded connection 10. In addition, the central part 5 can be provided with chamfered faces, which permit the engagement of a wrench. The first coupling part 1 is also provided with an internal, axially parallel through bore 6, which can e.g. be used as a channel for the drilling fluid to be supplied to the tool.
The second coupling part matching with the first coupling part of FIG. 1 is shown in side view in FIG. 2a and in front view in FIG. 2b. The second coupling part 12 essentially comprises a cylindrical reception body 13, which is bounded on one end face by a second and also planar contact surface 19 perpendicular to the coupling axis 11. From said second contact surface 19 is formed in the reception body 13 a reception bore 18 concentric to the coupling axis 11 and into which can be introduced with the desired fit the clamping trunnion 2 of the first coupling part 1.
The reception bore 18 is sufficiently deep that the clamping trunnion 2 is received in its full length. The two contact surfaces 4 and 19 are then directly in engagement with one another and can be initially loaded by means of a clamping device for introducing forces. The clamping device comprises a cylindrical clamping element 16 with a clamping element axis 15, which in the vicinity of the reception bore 18 acts transversely to the coupling axis 11 through the reception body and on the clamping surface (groove side 7) on the clamping trunnion 2. As the clamping element 16 has a conically tapering end (by approximately 45°, but not shown in FIG. 2), on inserting the clamping element 16 there is a clamping force deflected in the direction of the coupling axis, which presses together the two contact surfaces 4 and 19 and ensures the force transfer between the coupling parts 1 and 12.
For the connection of the second coupling part 12 to the tool reception device of a machine or the like in the example of FIG. 2 at the other end of the reception body 13 is provided an axial tapped bore 17 with the standard undercut and which is connected by a connecting bore 14 to the reception bore 18 for passing on any liquids. As in the case of the first coupling part 1, the tapped bore or hole 17 could obviously be replaced by other connecting devices.
Whereas FIGS. 1 and 2 relate more to the overall arrangement of the coupling, FIGS. 3 and 4 give those details which are essential for the invention. FIG. 3a shows on a larger scale the clamping trunnion 2 with the clamping groove 3 of the FIG. 1 and which cooperates with the clamping element by means of the first groove side 7. For reasons of clarity the second coupling part 12 is not shown. In this example the clamping element is a locking screw 22 with a conical screw end 23 and a hexagonal recess 20. The screw axis 21 of the locking screw 22 is in the middle plane 8 of the locking groove 3.
On screwing in the locking screw 22 the conical screw end 23 initially only rests on the first groove side 7 and consequently produces a clamping force directed to the left in the drawing and which presses the first contact surface 4 against the not shown, second contact surface 19 of the second coupling part. This is achieved in the case of an identical distance from the groove sides 7,9 to the middle plane 8 in that the first groove side 7 is moved radially outwards relative to the second groove side 9.
The bearing area of the first groove side 7 is then increasingly elastically deformed on further insertion of the locking screw 22 until the screw end 23 rests on the second groove side 9 after covering a clamping path a. Therefore the second groove side 9 forms a stop, which makes the further insertion more difficult and consequently in simple manner reliably limits the clamping path and therefore the forces which occur. However, such a limitation of the clamping path is only possible because in the case of the coupling according to the invention special precautions are taken to largely exclude plastic deformations during the initial loading. For this purpose on the clamping trunnion 2, which is made from a surface-hardened material, preferably steel, is provided a special clamping surface 24 located in the first groove side 7 and which is shown in broken line form in FIG. 3a and in plan view in FIG. 3b. The shape of the clamping surface 24 is completely adapted to the conical screw end 23 (geometrically true). Prior to the hardening of the clamping trunnion it is introduced by cold extrusion in the first groove side 7. This can e.g. be brought about by inserting the locking screw 22 or by inserting a comparable, specially hardened screw or by inserting a correspondingly shaped bolt. So that during the subsequent use of the coupling the clamping surface 24 and the clamping element are always aligned, it is possible to use additional adjusting and setting aids, e.g. the pin 35 shown in exemplified manner in FIG. 1a, as well as the matching blind hole 36 in FIG. 2a.
As a result of the cold extrusion the material layer located below the clamping surface 24 is plastically deformed and forms a very homogeneous workhardening zone 25 provided with particularly advantageous mechanical characteristics (FIG. 3b). The necessary dimensions for the clamping groove 3 and its sides 7,9, as well as the depth of the impression 24 and the length of the clamping path a result from the nature of the material used and the requirements made on the coupling.
The introduction of the clamping surface 24 has the following consequences:
by the adaptation of the clamping surface to the conical shape of the screw end the force is introduced from the screw into the clamping trunnion over a larger surface, so that the compressive load in the surface and consequently the plastic deformation risk is reduced;
the workhardening zone has an increased hardness and breaking strength, so that plastic deformations are largely avoided with the initial loads which occur and high initial loads can be produced over short clamping paths;
as the workhardening is only limited to a relatively thin zone, the necessary toughness of the underlying material is completely retained.
Obviously the example of FIG. 3 is not the only possible design of the clamping side and clamping element. Other preferred constructions are shown in FIG. 4, the representations of FIGS. 3a and 4a, as well as 3b and 4b/4c correspond. In general, in the embodiment of FIG. 4 in place of the clamping groove there is a planar clamping slot 31 milled into the clamping trunnion and running transversely to the coupling axis 11 and which is bounded on both sides of the middle plane 30 by sloping slot sides 29,32. The clamping element is in this case a clamp bolt 26 with a bolt axis 27 and a conically tapering bolt end 28. It is obvious that within the scope of the invention the said clamp bolt can also be combined with the clamping groove 3 of FIG. 3 or the locking screw 22 of FIG. 3 can be combined with the clamping slot 31 of FIG. 4.
Like the locking screw of FIG. 3, the clamp bolt 26 presses with its conical bolt end on the clamping surface 24 in the first slot side 29. Pressure is supplied to the first slot side 29 before the second slot side 32 in this case in a different way from that of FIG. 3. The slot sides 29,32 are arranged in mirror symmetrical manner to the middle plane 30. The bolt axis 27 of the clamp bolt 26 is not located in the middle plane 30 of the clamping slot 31 and is instead displaced towards the first slot side 29, but the action obtained is the same.
Although the placing of the clamping element (locking screw or clamp bolt) on the second groove side 9 or the second slot side 32 has the consequence of a clear resistance to further prestressing, in certain circumstances it can occur that as a result of the small bearing surface plastic deformations occur on the second side and reduce the limiting or bounding effect. In order to prevent such deformations, it can be advantageous in accordance with FIG. 4c to provide on the second side, in this case the second slot side 32, a stop face 33 with a corresponding workhardening zone 34, which is produced in the same way, namely by cold extrusion prior to hardening, as the clamping surface 24. Both the surfaces 24 and 34 can e.g. be simultaneously produced in that prior to hardening and using a bolt comparable to the clamp bolt and whose axis is located in the middle plane 30, pressing occurs in the clamping slot. Here again it is obvious that the two surfaces 24 and 34 according to FIG. 4 can be advantageously used in the embodiment of FIG. 3.
The hitherto considered clamping element 16 (FIG. 2b), apart from the axial force component also produces a radial force component, which leads to a one-sided loading of the coupling perpendicular to the coupling axis 11. To reduce or completely prevent such a one-sided loading, according to another embodiment of the invention several clamping elements can be used, which are spaced from one another by an angular distance around the coupling axis 11. Various, non-exhaustive examples of such arrangements are shown in FIGS. 5a to c in a manner corresponding to FIG. 2b. In the case of FIG. 5a two clamping elements 16a, 16b are arranged perpendicular to one another, whereas in FIG. 5b two clamping elements 16a, 16b diametrically face one another. Finally, in FIG. 5c there are in all three clamping elements 16a-c, which are in each case mutually turned by 120°.
It is vital in all cases that prior to hardening the geometrically true impression 24 with the underlying workhardening zone 25 is produced by plastic deformation in the clamping surface. The resulting improvement is made clear by the diagram of FIG. 6 which, in comparative manner, shows the attainable clamping force K as a function of the load reversal number N LW for a conventional coupling without impression (curve cl) and a coupling with impression according to the invention (curve c2). In the case of the conventional coupling the attainable clamping force starts at a relatively low value Kl, because there are strong plastic deformations in the clamping surface. Only with an increasing load reversal number (clamping-unclamping) does a workhardening occur, which leads to a hardening of the clamping surface and to an asymptotic approach to a final or end value A1.
With the coupling according to the invention the clamping force starts with a starting value higher by a factor of more than 2 and with the load reversal number approaches in a much flatter curve and in asymptotic manner a much higher end or final value A2.
In the embodiment shown in FIGS. 1 and 2 there is only a single clamping element 16 and a single clamping surface 24, so that both coupling parts 1 and 2 can only be positioned in a single mutual position for clamping purposes. This position is e.g. ensured by a positioning aid comprising a pin 35 and a blind hole 36. In the rough, everyday use of the coupling such a singular positioning possibility can prove cumbersome and not very flexible. To bring about an improvement here, according to a further development of the invention for a clamping element is provided a plurality of similar clamping surfaces arranged in rotationally symmetrical manner about the coupling axis. For the relative positioning of the coupling parts there are then positioning means, so that selectively one of the clamping surfaces faces the clamping element in the position suitable for clamping.
A preferred embodiment of such a coupling with a multiple (four-fold) positioning possibility is shown in FIGS. 7 and 8. The second coupling part 12 shown in longitudinal section (a) and in front view (b) in FIG. 7 has the following changes compared with FIG. 2. The diameter of the second contact surface 19 is reduced and is lowered relative to the end face of the reception body 13. Therefore the second contact surface 19 is better protected against mechanical damage. In addition, on the reception body 13 there are two positioning flaps 38a, b, which are milled out and project from the end face in the direction of the coupling axis 11 and which in each case have an inner surface 41 suitable for positioning purposes and parallel to the coupling axis 11. The two positioning flaps 38a, b diametrically face one another. The first positioning flap diametrically faces the locking screw thread 37 provided for the locking screw 22, i.e. the clamping element.
In the first coupling part 1 shown in side view (a) and front view (b) in FIG. 8 the first contact surface 4 has a reduced diameter corresponding to the second contact surface 19. Below the first contact surface 4 a square 40 is worked out of the central part 5 of the coupling part 1. The square 40 is laterally bounded by four positioning surfaces 39a-d, which are pairwise at right angles to one another and can in each case be passed into one another by a 90° rotation. With each of the positioning faces 39a-d is associated a clamping surface 24a-c on the clamping trunnion 2. The association is chosen in such a way that one of the clamping surfaces 24a-c always comes to rest in a position suitable for clamping below the clamping element, if the corresponding clamping surface engages on the inner surface of the positioning flap. In this way it is possible to obtain four equivalent positioning possibilities, the positioning flaps 38a, b, in conjunction with the square 40, facilitating the correct positioning on introduction. It is obviously also conceivable in place of the 4-fold rotational symmetry shown, to use another rotational symmetry in order to increase the number of positioning possibilities.
It is finally expressly pointed out once again that a coupling according to the invention is not only suitable for the transmission of dynamic forces, such as e.g. occur with tools driven by machines, but can also be used for static forces, e.g. for the detachable connection of the elements of a framework, skeleton structure, etc.
______________________________________List of reference numerals______________________________________1,12 Coupling part2 Clamping trunnion3 Clamping groove4,19 Contact surface5 Central part6 Through bore7,9 Groove side8 Middle plane (clamping groove)10 Threaded connection11 Coupling axis13 Reception body14 Connecting bore15 Clamping element axis16,16a-c Clamping element17 Tapped hole18 Reception bore20 Hexagonal recess21 Screw axis22 Locking screw23 Screw end (conical)24 Clamping surface25,34 Workhardening zone26 Clamp bolt27 Bolt axis28 Bolt end (conical)29,32 Slot side30 Middle plane (clamping slot)31 Clamping slot33 Stop face35 Pin36 Blind hole37 Locking screw thread38,38a,b Positioning flaps39a-d Positioning surface40 Square41 Inner surfacea Clamping pathA1,A2 End value (asymptotic)c1,c2 CurveK Clamping forceK1,K2 Initial value (clamping force)N.sub.LW Load reversal number______________________________________
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In a coupling with two sections (1, 12) which are prestressed by a tensioning device with at least one cylindrical tensioning component (16) in which one conical end tranverse to the coupling axis (11) of the tensioning component (16) acts on a tensioning surface (24) arranged obliquely to the coupling axis (11) and generates a tensile force acting in the direction of the coupling axis (11), an improvement in the mechanical behavior is attained in that the coupling sections (1, 12) are made of a case-hardened material, preferably steel, the tensioning surface (24) espouses the surface of the conical end of the tensioning component and the latter (24) is made by cold extrusion before hardening.
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BACKGROUND OF THE INVENTION
Dry toner electrostatic printing inks, including laser and xerographic inks, are important and growing contaminants in the area of wastepaper recycling. Traditionally, paper has been printed with water or oil-based inks which were adequately removed by conventional deinking procedures. In these methods, secondary fiber is mechanically pulped and contacted with an aqueous medium containing a surfactant. Ink is separated from pulp fibers as a result of mechanical pulping and the action of the surfactant. The dispersed ink is separated from pulp fibers by such means as washing or flotation.
Conventional deinking processes have shown minimal success in dealing with dry toner electrostatic printing inks, with the necessary chemical and mechanical treatments of the furnish proving to be time consuming and often rendering a furnish which is unacceptable for many applications. The development of a deinking program for office waste contaminated with electrostatic printed copy will make this furnish more amenable to the recycling process.
The ability to recycle office waste will prove commercially advantageous and will have a significant impact on the conservation of virgin fiber resources. Although electrostatic printed waste has not reached the volume of impact printed waste commonly seen in the industry, indications are such that usage of electrostatic print is increasing steadily and that waste copies available to the recycling industry will also increase.
Some deinking systems employ chemical aggregation and densification followed by forward cleaning to remove non-impact inks, and flotation deinking to remove impact inks (i.e., offset) and other contaminants. The chemical nature of many of these deinking products has caused them to act as defoamers in aqueous papermaking systems. A separate flotation aid is thus often added to the flotation cell in order to overcome the defoaming effect of the earlier chemicals.
A major difficulty in utilizing mixed office waste as a recycled fiber source is the high level of laser and xerographic ink contaminants. Laser and xerographic inks use dry toner rather than ink. During the process, heat or the combination of heat and pressure are applied to cause the toner particles to fuse to the paper surface and one another. Toner may be removed from the fiber surface by repulping under alkaline conditions. However, the separated particles are flat, plate-like, of varying size, and have a density close to that of water. These inks should be separated from the fiber and reduced to a particle size range that will facilitate removal through mechanical means (e.g., flotation).
A problem in using mixed office waste in a recycle stream is dealing with the extreme pH and temperature adjustments in the pulping sequence, which facilitate release/separation of the laser/xerographic ink particles from the fiber. The present invention allows for the separation of ink particles at lower pulping temperatures and pH levels. Removal of the inks using flotation in turn minimizes water usage and the effluent accumulation seen with washing.
DETAILED DESCRIPTION OF THE INVENTION
The present invention provides a process for the deinking of wastepaper containing electrostatic printed ink, impact printed ink, or combinations thereof, which comprises adding to an aqueous slurry of the wastepaper a nonionic surfactant of the Formula I:
R--O--(CH.sub.2 CH.sub.2 O ).sub.n H (I)
wherein:
R is a C 10 to C 15 branched alkyl; and
n denotes the average number of ethylene oxide units and is a whole or fractional number ranging from about 5 to 8.
Preferred compounds of the Formula I are those wherein R is C 11 to C 14 branched alkyl and n is a whole or fractional number of from about 6to 7.
A branched chain polyethoxylated tridecyl alcohol with a distribution of chain lengths of 11 to 14 carbon atoms (13 carbon unit, or hydrophobe most frequently occurring) and with the general molecular structure (C 2 H 4 O ) n C 13 H 28 O where n=6-7 was found to be particularly effective for flotation of laser/xerographic inks.
Branched alkyl units represent the hydrophobic end of the surfactant and contain carbon atoms with primary, secondary and tertiary carbon-carbon bonds, while a linear alkyl unit, in contrast, contains primary and secondary carbon atoms.
Major hydrophobe isomers are tetramethylnonane, trimethyidecane, and trimethylnonane. Nearly all isomers contain one methyl group in the C-1 position. Product efficacy was evident under pH 5 to 11 and lower temperature (32° to 49° C. ) pulping conditions. Treatment levels of at least about 0.25 pound/ton based on the weight of pulp are effective when added to the wastepaper stocks.
The nonionic surfactant of the present invention may have a hydrophile-lipophile balance (HLB) of from about 10-13, with an HLB of from about 11-12 preferred.
In the examples that follow, the branched polyethoxylated tridecyl alcohol (isotridecyl alcohol ethoxylate) described above as particularly effective for flotation of laser/xerographic inks was added to a pulper at varying temperature/pH/ product dosages using a furnish containing a high level of xerographic office waste. After the pulping was complete, the stock was diluted to 1% consistency and ink removed using a flotation cell. It is theorized that the high level of branching for the polyethoxylated tridecyl alcohol enhanced the removal of these difficult inks. The branched chain polyethoxylated tridecyl alcohol was compared to a linear alcohol ethoxylate having the same moles of ethoxylation, similar HLB, and similar molecular weight in an effort to directly compare ink removal efficiency of the two structures.
TABLE I______________________________________Branched vs Linear Alcohol Ethoxylate moles of ethoxylation HLB alcohol ethoxylated______________________________________Branched Isotridecyl 7 11.5 C.sub.11 -C.sub.14Alcohol Ethoxylate C.sub.13 richLinear 7 12.0 C.sub.12 -C.sub.15Alcohol Ethoxylate______________________________________
The branched alcohol ethoxylate and linear alcohol ethoxylate were added to pulpers containing furnish containing primarily xerographically printed office waste under the conditions shown in Table II.
TABLE II______________________________________Pulping Pulping Pulping PulpingTemperature pH #/T Consistency.sup.1 Time______________________________________32° C. and 49° C. 5, 8 and 11 1 and 2#/T as 5% 45 min. calculated on dry weight of pulp______________________________________ .sup.1 Grams dry fiber per 100 grams slurry.
After deinking/pulping was complete, the stock was diluted to 1% consistency. A two gram pulp pad was formed for evaluation. This was the flotation cell feed. Flotation was performed using a flotation cell at 44° C. for five minutes. Flotation accepts (the material remaining in flotation cell after ink-containing froth has been skimmed off) were formed into two gram filter pads to minimize the dilution/washing effects of handsheet formation.
Product performance with respect to ink removal across the flotation cell was quantified using a standard handsheet analyzer. This system measures dirt/ink in finished paper, board and handsheets with a speck detection range from 63-2600 microns diameter. The performance of the branched alcohol ethoxylate was compared to the linear alcohol ethoxylate and an untreated control at each pH and temperature condition.
At a pulping temperature of 32° C., the branched alcohol ethoxylate showed significant improvements in ink removal efficiency over the linear alcohol ethoxylate at both 1 and 2#/T at pH 5, 8 and 11.
These results are displayed in Tables III and IV.
TABLE III______________________________________Removal Efficiency at Pulping Temperature of 32° C.1#/T Calculated by Dry Pulp WeightTreatmentBranched vs Flotation Feed Flotation Accepts % RemovalLinear Alcohol ppm ink ppm ink AcrossEthoxylate 63-2600 microns 63-2600 microns Flotation Cell______________________________________Branched 3134 136 96%pH 5Linear 2453 462 81%pH 5Branched 3105 214 93%pH 8Linear 2999 822 73%pH 8Branched 1895 657 65%pH 11Linear 2442 2298 13%pH 11______________________________________
TABLE IV______________________________________Removal Efficiency at Pulping Temperature of 32° C.2#/T Calculated by Dry Pulp WeightTreatmentBranched vs Flotation Feed Flotation Accepts % RemovalLinear Alcohol ppm ink ppm ink AcrossEthoxylate 63-2600 microns 63-2600 microns Flotation Cell______________________________________Branched 2017 124 94%pH 5Linear 2717 481 83%pH 5Branched 3612 195 95%pH 8Linear 3695 439 86%pH 8Branched 2456 324 87%pH 11Linear 2330 684 72%pH 11______________________________________
At a pulping temperature of 49° C., the branched alcohol ethoxylate again showed significant improvements in ink removal efficiency over the linear alcohol ethoxylate at both 1 and 2#/T as product at pH 5, 8 and 11. These results are displayed in Tables V and VI.
TABLE V______________________________________Removal Efficiency at Pulping Temperature of 49° C.1#/T Calculated by Dry Pulp WeightTreatmentBranched vs Flotation Feed Flotation Accepts % RemovalLinear Alcohol ppm ink ppm ink AcrossEthoxylate 63-2600 microns 63-2600 microns Flotation Cell______________________________________Branched 6577 292 95%pH 5Linear 5646 5930 No RemovalpH 5Branched 2605 273 90%pH 8Linear 6697 6257 22%pH 8Branched 2528 1003 60%pH 11Linear 4883 4892 No RemovalpH 11______________________________________
TABLE VI______________________________________Removal Efficiency at Pulping Temperature of 49° C.2#/T Calculated by Dry Pulp WeightTreatmentBranched vs Flotation Feed Flotation Accepts % RemovalLinear Alcchol ppm ink ppm ink AcrossEthoxylate 63-2600 microns 63-2600 microns Flotation Cell______________________________________Branched 3666 138 96%pH 5Linear 3466 517 84%pH 5Branched 3533 140 96%pH 8Linear 3453 483 86%pH 8Branched 2169 846 61%pH 11Linear 3032 2039 35%pH 11______________________________________
The results of these studies demonstrate that the branched alcohol alkoxylate was significantly more effective than the linear alcohol alkoxylate with respect to the removal of laser/xerographic inks via flotation. This was particularly evident at ambient pH (5 to 8). The branched alcohol ethoxylate tested remained effective at treatment levels as low as about 1 pound/ton based on dry pulp weight, with as much as about 95% ink removal across the flotation cell.
While this invention has been described with respect to particular embodiments thereof, it is apparent that numerous other forms and modifications of this invention will be obvious to those skilled in the art. The appended claims and this invention generally should be construed to cover all such obvious forms and modifications which are within the true spirit and scope of the present invention.
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A process for the deinking of wastepaper is disclosed. The process comprises administering a sufficient amount of a branched alcohol alkoxylate surfactant to a sample of waste paper for which treatment is desired. The surfactant is effective for the flotation of the ink.
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BACKGROUND AND OBJECTS OF THE INVENTION
The present invention relates generally to two-cycle engines and more particularly to certain new and useful improvements in the intake, upper cylinder charging and the exhaust systems of two-cycle engines which may be manufactured at low cost with relatively few and substantially simple operating parts, while increasing engine life and offering more efficient and consistent power outputs at high and low speeds and high and low compression than in two-cycle engines heretofore known. As will become evident from the description of the invention, the invention has applicability to two-cycle engines wherein combustion is effected by either electrical spark or diesel effect.
Previously known two-cycle engines generally comprise cylinder housings enclosing one or more engine cylinders, each formed with a fuel transfer passage external of the cylinder to provide an access conduit for transferring fuel, which has been compressed in the crankcase, from the crankcase into the combustion chamber. Each engine cylinder contains a piston, slidable therein, which is generally formed with a port in its side for registering with one end of the fuel transfer passage to allow flow into the combustion chamber. In accordance with some of these known engine configurations, when the piston port and transfer passage are in registration, either in whole or in part, fuel passes from the passage into the piston itself for discharge into the combustion chamber through an open nozzle in the piston. In accordance with other known engine constructions, when the piston port and transfer passage are in registration, fuel flows from the piston port into the entrance of the transfer passage which exits in the combustion chamber.
Although these known engine constructions have proved adequate for low speed operation and low compression adaptations, the complexity of the cylinder, housing and piston structures necessitates multiple and intricate fabrication techniques to which high manufacturing costs are attributable. Furthermore, these engines experience significant flow losses in charging the combustion chamber and have a relatively low efficiency and power output. For example, the relatively short period of time that the piston port and transfer passage are in registration -- either in whole or in part -- as well as the dimensions of the fuel transfer passage limit the charging of the combustion chamber such that reliable and proper charging cannot be assured. Furthermore, the piston structures are generally heavy or provided with very complex surfaces, thereby reducing the output of the engine. These considerations are significant in reducing power output and preventing higher efficiency, especially at high speed operation or in high compression operation adaptations.
Other known two-cycle engine constructions are provided with pistons formed with projections or other irregular structures protruding into the combustion chamber to guide incoming flow from transfer or bypass channels. Such structures complicate fabrication and are susceptible to damaging as a result of local overheating, thereby shortening the useful life of the engine.
One prior art two-cycle engine construction utilizes a piston formed with an inlet port on its top surface, controlled by a pressure operated valve. An example of this engine is disclosed in U.S. Pat. No. 1,082,402 to Campbell. Although such engines may offer certain advantages, they are usually complicated with cams, lifters and heavy spring-loaded valves. Consequently, these engines have not proved to be efficient and generally suffer from power output losses, especially at high speed and/or high compression operation.
However, none of these known constructions provide for introducing an adequate charge for combustion into the combustion chamber throughout their range of operation. Moreover, no two-cycle engine has been developed which provides a mechanically simple and relatively inexpensive means for assuring proper and reliable charging of the combustion chamber in engines operating at high and low speeds and high and low compression, to generate consistently high efficiency and high power output in all such ranges of operation. Furthermore, no two-cycle engine has been developed which is capable of long life and extended use in high speed and/or high compression applications.
It is therefore an object of the present invention to provide a new and improved two-cycle engine.
It is another object of the present invention to provide an improved fuel and/or air intake, charge introduction and exhaust system in two-cycle engines.
It is still another object of this invention to provide a mechanically simple two-cycle engine capable of higher power output and efficiency than heretofore achieved.
It is also an object of this invention to provide a new two-cycle engine capable of easy and inexpensive fabrication.
It is still another object of the present invention to provide a new piston assembly for use in two-cycle engines, which controls the fuel and/or air intake, the introduction of a fresh charge into the combustion chamber and the exhaust of burned gases.
It is also an object of the present invention to provide a charge introduction system for use in two-cycle engines whereby the piston is cooled to allow use for extended periods of time.
It is yet another object of the present invention to provide a light piston for higher output and efficiency than heretofore achieved in two-cycle engines.
It is a further object of the present invention to provide a two-cycle engine free from extra-cylinder air or air/fuel passages.
It is another object of the present invention to provide a two-cycle engine having relatively few moving parts.
It is yet another object of the present invention to provide a two-cycle engine wherein fuel is evaporated to ensure good mixture formation while the piston is simultaneously cooled.
It is still another object of the present invention to provide a two-cycle engine capable of efficiently generating reliable power output at high and low speeds of operation and high and low compression.
It is yet a further object of the present invention to provide a structurally simple two-cycle engine capable of use for extended periods of time at high speed and/or high compression operation.
These and other objects, features and advantages of the present invention will become more apparent when the detailed description of the preferred embodiments is considered in light of the drawings.
The invention consists of the novel parts, constructions, arrangements, combinations and improvements herein shown and described.
SUMMARY OF THE INVENTION
Briefly, the two-cycle engine according to the present invention comprises an engine block which houses a crankcase and at least one engine cylinder adjacent a crankcase. The engine cylinder is partitioned into an upper portion including the combustion chamber and a lower portion including the crankcase by a piston assembly slidable therein. The upper cylinder portion is formed with an exhaust port positioned just above the top of the piston at its lower deadpoint and the lower cylinder portion is formed with an intake port which may be operated by the piston itself or by a pressure sensitive valve.
The piston assembly comprises a generally hollow piston formed with at least one charging passage in its top surface providing communication between the lower cylinder and the combustion chamber for introducing a fresh charge of air and/or fuel into the combustion chamber. Each passage is controlled by a membrane-like valve rigidly affixed to the top of the piston in a cantilever fashion so as to be sensitive to changes in pressure. Advantageously, each charging passage is formed with an angularly outward slant through the top of the piston and the membrane valve is attached so that it opens in the same direction as said angularly outward slant so that they coact to direct the incoming flow toward the cylinder wall away from the exhaust ports. Also advantageously, the piston may be formed with a plurality of relatively small, closely grouped charging passages controlled by valves such that one membrane valve controls at least one group of passages.
Advantageously, the intake port is formed in the wall of the lower cylinder portion and is controlled by the piston for providing the initial intake of air and/or fuel from a carburetor or other suitable source. As here preferably embodied, the intake port may be positioned just below the top of the piston at its lower deadpoint and the exhaust port is formed in the upper cylinder wall slightly above the top of the piston at its lower deadpoint. Thus, both the intake port and the exhaust port are closed during most of the piston travel except when the piston nears one of its deadpoints.
In operation, as the piston rises toward its upper deadpoint during its return stroke, it generates a vacuum in the lower cylinder whereby air and/or fuel is drawn in from a carburetor or other suitable source through the open intake port. After ignition of the previous combustible charge in the combustion chamber, the piston is forced downwardly toward its lower deadpoint, ending the vacuum effect in the lower chamber, and closing the intake port, creating a closed lower chamber wherein the dropping piston compresses the fresh contents thereof.
A point is reached at which the pressure generated by the expanding gases in the combustion chamber is in substantial equilibrium with the pressure of the compressed contents in the lower cylinder so that the pressure in the lower chamber begins exceeding that in the upper cylinder. This pressure differential causes the pressure sensitive valve on the piston head to open and allow introduction into the combustion chamber of the fresh charge of air or air/fuel mixture from below.
When the piston nears its lower deadpoint at the end of its power stroke, the exhaust port is exposed by the piston, whereby the burned gases from combustion are vented to the exhaust as well as being forced out by the circulation of the incoming charge. In addition, the open exhaust port relieves the residual pressure in the combustion chamber to allow entry of a full charge.
At the piston's lower deadpoint, the pressures in the two chambers are again in substantial equilibrium so that, as the piston rises on its return stroke, a slightly greater pressure from above causes the valve to close. The piston quickly closes the exhaust port and begins compressing the charge now contained in the combustion chamber until it reaches its upper deadpoint at which time the cylinder is fired either by an electrical spark or by the injection or fuel according to the diesel effect. Accordingly, as the piston traveled toward its upper deadpoint, the intake step was repeating, as described above, for continuous operation of the engine.
Advantageously, the piston may be formed with three groups of charging passages generally near the outer circumference of its top surface and a solid sector at least equal in width to the width of the exhaust port. Also advantageously, a multi-layered single membrane valve of a generally clover-leaf configuration may be used for controlling the three groups of passages.
In other embodiments of the two-cycle engine of the present invention, the intake port is formed in the wall of the crankcase and controlled by a pressure-sensitive valve attached thereto.
In yet other embodiments of the invention, the piston may be formed with a plurality of charging passages formed in a circumferentially outer zone and controlled by a thin disc-like membrane valve "hinged" between the piston top and a piston head. The piston head is formed with a plurality of rib members to restrict movement of the valve and with a plurality of dispensing ports adapted to direct the flow of the incoming charge toward the cylinder walls and away from the exhaust port. In addition, the engine cylinder and the crankcase may be separated, the piston and piston rod elongated for use as a large two-cycle engine such as those aboard marine vessels.
Two-cycle engines embodying the foregoing constructional features are significantly improved over previously known constructions in reliability of performance, long life, higher outputs and efficiency, simplified fabrication and repair, and lower costs thereof.
It has been found that two-cycle engines constructed in accordance with the principles of the present invention do not require fuel transfer passages or other extra-cylinder crankcase ventilation ducts for directing a fresh charge of air and/or fuel into the combustion chamber, avoiding the normally attendant flow losses. Moreover, consistent introduction of a full fresh charge into the compression chamber is assured with substantially no loss of the fresh charge for all speeds of operation and in all adaptations of compression. The power output of engines utilizing the improved charge introduction system according to the present invention is increased by about 20% over that of comparably dimensioned two-cycle engines heretofore known, with a significant reduction in fuel consumption. In addition, the intake of the fresh charge, its introduction into the combustion chamber and the exhaust of burned gases is substantially totally dependent upon differences in dynamic pressure generated within the engine during its operation. Accordingly, the flow controlling valves are subjected to substantially little stress for increased useful life.
It has also been found that the charge introduction system and the engine structure according to the present invention provides a circulatory charge flow in the combustion chamber whereby substantially all of the burned gases are driven from the combustion chamber and replaced by the fresh charge with negligible loss thereof. In addition, by providing charge transfer through the piston, the piston is cooled by the flow of the charge therethrough, and, if the charge contains a fuel component, the fuel is evaporated by the hot piston to improve combustion.
The two-cycle engine according to the present invention is structurally less complicated and less expensive to fabricate than two-cycle engines heretofore known. It has relatively few moving parts for long engine life and easy repair. Moreover, the piston assembly according to the present invention is relatively light yet, due to the size and spacing of charging passages, it maintains the structural integrity of a solid-top piston for translating the full force of combustion to the crankshaft.
Furthermore, in adaptations of the present invention to large high compression engines, such as those used aboard marine vessels, the use of turbo-blowers for force feeding air into the lower engine cylinder is obviated. Thus, the high costs of such devices as well as the power losses attributable thereto are eliminated, providing an increase in power output and improved fuel consumption.
It should be understood that the foregoing general description and the following detailed description are exemplary of the invention and not restrictive thereof.
The accompanying drawings, referred to hereinafter illustrate preferred embodiments of the invention and, together with the detailed description, serve to explain the principles of the invention.
DESCRIPTION OF THE DRAWINGS
FIGS. 1a-d are schematic representations illustrating several aspects of the present invention.
FIGS. 2a-b are two side views of a piston assembly according to one aspect of the present invention.
FIGS. 3a-b are top views of a piston head and associated membrane valve according to one embodiment of the present invention.
FIG. 4 is a top view of a piston head and valve assembly according to another embodiment of the present invention.
FIGS. 5a-d are various views of a piston assembly according to yet another embodiment of the present invention.
FIGS. 6a-b are side views of one embodiment of the present invention adapted for use in large engines.
FIG. 7 is a view taken along section 7--7 of FIG. 6a.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring generally to FIGS. 1a-d, certain aspects of the present invention are illustrated schematically. FIGS. 1a-d show engine cylinder 10 which comprises essentially upper cylinder portion 10a and essentially lower cylinder portion 10b, separated by piston assembly 12, slidable therein. Piston 12 is connected to crankshaft 14, which is rotatably mounted in crankcase 16, by connecting means 18 rotatably mounted to crankshaft 14 and pivotally mounted to piston 12 for translating linear movement of the piston to rotation of the crankshaft. Connecting means 18 may be any conventional crankshaft-piston rod connector. Crankcase 16 and cylinder 10 may be spatially united as shown generally in FIGS. 1a-d for use in relatively small two-cycle engines such as in motorcycles or outboard marine engines, or they may be two independent chambers as disclosed more fully with reference to FIGS. 6a-b.
As shown in FIGS. 1a-c, intake port 20 may be formed in the wall of the crankcase 16 for the initial intake of a fresh charge of air and/or fuel from a carburetor or other source thereof (not shown) and controlled by means of a pressure sensitive valve 21 connected in cantilever fashion to the inside wall of crankcase 16. Advantageously, valve 21 may be a single sheet of resilient material, such as spring steel, and connected at its center to structural projection 23 in intake port 20 so as to be substantially sensitive to pressure variations. Exhaust port 22 is formed in the wall of the upper cylinder portion 10a, so as to be controlled by piston 12. Advantageously, exhaust port 22 may be located such that its bottom is positioned slightly above the top of piston 12 at its lower deadpoint but above the bottom of piston 12 at its upper deadpoint, as shown generally in FIGS. 1a-d. Thus, upper cylinder 10a is a closed chamber during most of the piston stroke so that only burned gases escape through the exhaust port with minimal, if any, loss of an incoming fresh charge.
Piston 12 is slidably positioned within cylinder 10, sealingly engaging the walls of the cylinder such that the volume of the two chambers, 10a and 10b, is continuously changing during operation of the engine. The piston 12 is generally hollow, having central cavity 24 substantially open at its bottom to lower portion 10b of the cylinder. The top surface of the piston is formed with at least one charging passage 26 for providing communication between central cavity 24 and therefore the lower cylinder portion 10b and upper cylinder portion 10b. Passage 26 is controlled by a substantially pressure sensitive membrane-like valve 28 affixed in cantilever fashion to the piston top with its free end opening away from exhaust port 22 to direct flow of the incoming charge toward the cylinder wall, driving out essentially all burned gases through exhaust port 22 with no appreciable loss of the fresh charge. Advantageously, valve 28 may be a flap valve comprising a substantially thin sheet of resilient heat resistant material such as spring steel. Also advantageously, passage 26 may be formed on an angularly outward slant to aid valve 28 in deflecting incoming flow towards the cylinder walls and enhance scavenging of the cylinder by driving burned gases through exhaust port 22, as shown in FIG. 1b, with essentially no appreciable loss of the fresh charge.
Advantageously, valve 28 may be formed with multiple layers of successively shorter, substantially identical, valve members, such as 28a, 28b, etc. illustrated in FIG. 2a, affixed to the top of piston 12 by at least two screws 42 made of a highly thermally resistive material. Accordingly, each upper valve member supports its bottom counterparts, as in a leaf spring, to provide resiliency to the valve and enhance the seal between valve 28 and the top of piston 12. Advantageously, attachment by two screws simplifies assembly as well as replacement of damaged or worn valves and prevents horizontal movement of the valve.
Referring now to FIGS. 1a-d, operation of a two-cycle engine according to one aspect of the instant invention as well as the advantages incident thereto can be appreciated. When piston 12 is positioned intermediate its upper and lower deadpoints as shown in FIG. 1a, exhaust port 22 is closed and both upper and lower chambers, 10a and 10b, respectively are substantially closed chambers. Thus, as piston 12 begins rising towards its upper deadpoint, either during start-up or as part of its return stroke, a vacuum is generated in the lower portion 10b of the cylinder, including the crankcase. Pressure sensitive intake valve 21 is opened under the influence of this vacuum and air and/or fuel is drawn through intake port 20 and into the crankcase from a carburetor or other suitable source (not shown) connected thereto by intake conduit 30.
When piston 12 reaches its upper deadpoint, the vacuum in the lower portion of the cylinder substantially ceases and intake valve 21 closes. Essentially simultaneously, the now-compressed previous charge of combustible mixture in the upper portion of the cylinder is ignited by either an electrical spark mechanism or the injection of diesel fuel, the force of combustion driving the piston downwardly on its power stroke, into the still closed lower chamber 10b. As the piston travels downwardly towards the lower deadpoint, it compresses the fresh charge just drawn into the lower portion 10b of the cylinder while allowing the burned gases in the upper cylinder to expand, relieving their pressure.
A point is reached at which the pressure generated by the expanding gases in the combustion chamber is in substantial equilibrium with the pressure of the compressed charge in the lower chamber. As the momentum of piston 12 carries it downwardly, its influence on the constituent(s) of the lower chamber tends to generate a greater gas pressure below the piston than above. Thus, depending on its resiliency, flap valve 28 is forced open at its free end and the fresh charge begins entering upper cylinder 10a and circulating therein as shown schematically in FIG. 1b.
As piston 12 continues downwardly on its power stroke, the gas pressure generated by the still expanding burned gases in upper chamber 10a continues to be relieved while the remaining charge in lower chamber 10b continues to be forced through charging passage 26 due to the tendency toward increased pressure imparted by piston 12 on its work stroke. Thus, the system within the closed cylinder is self-relieving by virtue of the piston assembly until the top of piston 12 drops below the top of exhaust port 22.
When the top of the piston drops below the level of exhaust port 22, the expanding burned gases in cylinder 10a escape therethrough, further relieving the pressure in the upper cylinder 10a, allowing the full fresh charge to fill upper cylinder 10a. Furthermore, the circulation of the entering flow enhances the evacuation of expended gases from the combustion chamber by circulating therein to drive them out through exhaust port 22, as shown by arrows 32, with negligible loss of the incoming fresh combustion charge.
When piston 12 reaches its lower deadpoint, the pressures in the two chambers 10a and 10b are in substantial equilibrium, such that, as piston 12 begins its return stroke, valve 28 is urged closed and residual burned gases are driven out of the cylinder 10a. After having travelled a distance equal to the height of exhaust port 22, upper portion 10a of the cylinder is sealed as a closed chamber in order that the charge contained therein may be compressed. Initially, as piston 12 moves upwardly, the tendency towards compressing the contents of upper portion 10a ensures secure closure of valve 28. Thus, as explained above, piston 12 travels upwardly as a movable partition between two closed but volume-changing chambers. When piston 12 reaches its upper deadpoint, the charge in chamber 10a is fully compressed and ignited either by an electrical spark to an air/fuel misture or by injection of fuel to compressed air according to conventional diesel engine principles while the intake cycle is being repeated for continuous operation of the engine.
Alternatively, intake port 20 may be formed in the wall of lower cylinder 10b, as shown in FIG. 1d, so as to be controlled by piston 12. Advantageously, the top of intake port 20 is formed slightly below the top of piston 12 at its lower deadpoint but below the bottom of piston 12 at its upper deadpoint. Thus, as piston 12 returns to its upper deadpoint, a vacuum of increasing strength is generated in lower cylinder 10b, also drawing valve 28 downwardly to enhance its seal with piston 12. When the bottom of piston 12 exposes port 20, the vacuum in cylinder 10b is relieved by drawing in a fresh charge of air and/or fuel through intake passage 30, this intake step continuing until the piston reaches its upper deadpoint. The force of combustion drives piston 12 downwardly on its power stroke, to close port 20 and begin compressing the fresh charge in cylinder 10b whereinafter the engine operates substantially as described with respect to FIGS. 1a-c. This configuration is particularly useful since, once the fresh charge has been drawn in through port 20, piston 12 closes it off to prevent the charge from escaping back therethrough as the falling piston begins compressing it on the work stroke.
Referring now to FIGS. 2a and 2b (which is a view along section 2b-2b of FIGS. 2a and 3a), there is shown a particularly useful piston assembly according to the present invention. Cavity 24 is formed substantially central to piston 12 connecting its bottom opening 23, and therefore lower cylinder 10b, to a plurality of charging passages 26 in the top of piston 12. Recesses 40 are formed on the sides of piston 12, near its top, to retain seal rings (not shown) for sealingly engaging the walls of the engine cylinder in substantially fluid-tight fashion for the range of pressures to be generated within the engine. Piston 12 may be pivotally connected to shaft 18 by any conventional means such as pivot rod 39 fitted within bore 36 and held by pins 38.
Charging passages 26 are formed with an angularly outward slant generally near the outer periphery of the piston, away from the center, to direct the incoming charge directly at the cylinder walls for ensuring substantially thorough scavenging of burned gases while providing a support section generally central of the piston top to permit attachment of the membrane inlet valve 28. Advantageously, piston 12 is formed with at least one group of relatively small, essentially closely spaced charging passages 26 to provide adequate access to upper cylinder 10a for the fresh charge contained in lower cylinder 10b.
Advantageously, a single pressure sensitive valve 28 is rigidly affixed by one end like a flap to the top of the piston, as by screws 42, to control at least one group of charging passages. In a particularly useful embodiment, the flap valve is formed by successively shorter, generally identical valve members, 28a, 28b, 28c, etc., with each layer supporting its lower counterparts as in a leaf spring to add resiliency.
Referring now to FIGS. 3a-b, there is shown a particularly useful embodiment according to this aspect of the present invention, wherein three groups of three charging passages 26 are formed in piston 12. Advantageously, passages 26 are relatively small as compared to the piston top area to maintain its structural integrity. Each passage within a group is separated from an adjacent passage by structural member 27a and each group of passages is separated from an adjacent group by a generally wider structural member 27b. Advantageously, membrane valve 28 may be generally circular with radially inward cut-outs 44 to form a generally clover-leaf valve as shown in FIG. 3b. Also advantageously, valve 28 may be formed in a multi-membered configuration, as described with reference to FIG. 2a, comprising a plurality of successively shorter, generally identical valve members. Cut-outs 44 generate valve sections 29, each controlling one group of passages 26 substantially independently such that valve 28 is substantially sensitive to pressure variations.
This configuration is particularly advantageous since structural members 27a support each valve section 29 from below to enable it to withstand the force of combustion and transfer it substantially undiminished to the crankshaft as if piston 12 were formed with a solid top. Furthermore, structural members 27b provide lands upon which seal sections 29 can act. Moreover, the membrane valve, being essentially a single valve which is centrally supported, may be rigidly affixed to the piston with four screws, thereby avoiding the addition of significant weight to the piston.
Advantageously, the top of piston 12 is also formed with a solid sector 46, as shown in FIG. 3a, providing a spacing width between charging passages 26 at least equal to the width of exhaust port 22. Accordingly, piston 12 is positioned within the cylinder such that solid sector 46 is adjacent exhaust port 22 so that the incoming charge is prevented from escaping through port 22. Thus, the incoming flow travels upwardly and outwardly toward the cylinder walls, away from the exhaust port, to circulate the cylinder so that it will "reach" exhaust port 22 only after it has driven substantially all of the burned gases out of upper chamber 10a, and has thereby filled it with a fresh charge of combustion constituents with substantially negligible loss thereof through the exhaust port.
Alternatively, as shown in FIG. 4, another particularly useful embodiment of membrane valve 28 according to the present invention may comprise a plurality of totally independent single-layer radially extending flap valve sections 48a. Each section is formed of a substantially resilient material and secured to the top of the piston by mounting plates 51 and screws 50, forming several cantilevered valves whose free ends control a group of charging passages 26 substantially as described with reference to FIGS. 3a-b. The use of screws to fasten the valves to the piston is particularly useful since it enables easy replacement of worn-out or fatigued valves. Furthermore, screws can better withstand the high temperatures generated in the cylinder than such other conventional fastening means as welding or soldering.
Advantageously, the piston according to this configuration can be provided with an additional set of charging passages 26a, as shown in FIG. 4. This set of passages is controlled by another single member flap valve, 48b, appropriately shaped to fit within the space defined by the base portions of the other valve members 48a. Valve 48b is formed similar to valve member 48a and rigidly affixed to the piston by mounting plate 51 and screws 50 so that its free end opens away from exhaust port 22 in order to achieve the advantages described above with reference to solid sector 46. Charging passages 26a provide additional conduits for feeding fresh air or air/fuel mixture into upper portion 10a of the cylinder to ensure that the combustion chamber is properly charged for efficient operation, especially at high speed or high compression. Furthermore, the combination of mounting plates 51 with single layered valve members 48a and 48b do not add significant weight to piston 12.
Referring now to FIGS. 5a-d, there is shown a piston assembly according to another aspect of the present invention. Piston 12 is provided with removable piston head 52 which fits within flanges 54 formed on piston 12. Unlike the embodiments described with reference to FIGS. 3a and 4, charging passages 26 may extend circumferentially around the central axis of the piston as shown in FIGS. 5a-b and may be essentially parallel to the piston axis, without any angular slant. Piston head 52 is formed with dispersing space 58 defined between the top of the piston 12 and the bottom of piston head 52. Piston head 52 is also formed with holes 57a circumferentially about its center and holes 57b substantially near its center. Radially extending rib members 60 are located between holes 57a and formed on the underside of head 52, extending into dispersing space 58 to define a substantially common plane along their lower edges which are spaced about 1/4 inch from the top of piston 12. Piston head 52 is secured to the piston by convenient means, preferably screws, with a flat, single-layer, generally flexible, circular membrane valve 62 fastened at portion 63 and hinged at 61 between trunk 52a of piston head 52 and the upper surface of piston 12. Thus, rib members 60 restrict the movement of valve 62.
Advantageously, head 52 may be formed with a domed upper surface in which dispensing ports 57a may be formed on an angularly outward slant to direct the incoming flow both upwardly and outwardly toward the walls of upper cylinder 10a. Also advantageously, ports 57b may be formed with an angularly inward slant but outwardly away from exhaust port 22. Furthermore, head 52 may also be formed with solid sector 66 positioned adjacent exhaust port 22 to prevent the incoming flow from being directed into the exhaust as explained above with reference to FIG. 3a. Advantageously, the width of solid sector 66 separating adjacent ports 57a may be at least equal to the width of exhaust port 22. Thus, with the radially outward slant of ports 57a and 57b and the solid sector 66, entering flow from lower cylinder 10b circulates the entire upper cylinder 10a to drive out substantially all the burned gases contained therein with substantially negligible losses of the incoming fresh charge.
Referring now to FIG. 5c, there is shown a particularly useful single-layer membrane valve 62 according to this aspect of the present invention. The valve is formed from a substantially circular disc 70 adapted to accommodate attachment to the piston 12, as, for example, by a screw inserted through opening 72. The valve is also formed with cut-outs 74 and 75 overlapping each other and surrounding the center of the disc to form a flexible "donut" valve which is highly sensitive to slight variations in pressure and offers little resistance to the incoming charge. Advantageously, cuts 74 and 75 are C-shaped as shown in FIG. 4c, generating substantially S-shaped "hinge" section 78 and an outer, generally donut-shaped, valve member 80.
In operation, as the piston is driven downwardly on its power stroke and the pressure in lower cylinder 10b exceeds that in upper cylinder 10a, the incoming charge is forced through passage 24 and charging ports 26. Since membrane valve 62 offers no appreciable resistance to the flows of the mixture, outer valve member 80 is immediately forced upwardly under the influence of the greater pressure from below, rising within dispersing space 58 until it abuts the bottoms of radial rib members 60, as shown in FIG. 5a. The incoming charge flows around the outer edges of the valve member 80 and through cut-outs 74 and 75 which have been expanded due to the rising of valve member 80. Thus, flow around member 80 generally flows through ports 57a while flow through cut-outs 74 and 75 generally flows through both ports 57a and 57b as indicated by arrows 64a and 64b in FIG. 5a.
Just after the piston has reached the lower deadpoint and the pressures in the two cylinder portions 10a and 10b are in substantial equilibrium, the piston begins rising, generating a slightly greater pressure in cylinder 10a. Membrane valve 80 is thereby closed onto the top of the piston 12, sealing off openings 26 substantially at the beginning of the return stroke. Thus, the membrane valve according to this aspect of the present invention is particularly useful in that, since it is highly sensitive to pressure differences, there is little stress placed on the hinge portions 78, allowing a substantially long life of the valve.
The two-cycle engine according to the present invention can be adapted for use in large engines such as diesel engines used aboard marine vessels. According to this aspect of the present invention, shown in FIGS. 6a and 6b, a substantially elongated piston assembly 82 is positioned slidably within engine cylinder 84 and provided with sealing rings 86 near both its top and bottom sections. Both cylinder 84 and piston assembly 82 are lengthened to accommodate the linear motion necessary to impart a driving torque to the crankshaft assembly and to provide adequate intake of air for the relatively high compression. The cylinder may be separated from the crankcase and crankshaft assembly by wall 88, provided with sealing assembly 89 to seal off cylinder 84 from crankcase 85. Sealing assembly 89 may be any conventional structure for accommodating both the substantially vertical and the slightly lateral motions of piston shaft 90 as it acts upon the crankshaft.
Piston assembly 82 comprises piston head 82a and piston skirt 82b, both in sealing engagement with the walls of cylinder 84. The length of the piston assembly 82 is equal to about one half the length of the cylinder 84. Cylinder 84 is formed with one or more intake ports 92 in its walls slightly below its midline, and with exhaust ports 94 in its walls slightly above the midline of the cylinder. Advantageously, these two ports are positioned such that at the lower deadpoint of piston 82, the top of the piston head is just below the bottom of each exhaust port 94 and at the upper deadpoint, the bottom of the piston skirt 82b is just above the top of each inlet port 92. Thus, the piston assembly seals off both the intake and the exhaust ports during most of each stroke to prevent undesirable losses of the fresh charge.
As the piston rises from its lower deadpoint, a vacuum is generated in the lower half of the cylinder, generally as described with reference to FIGS. 1a-c. Piston head 82a closes off the exhaust port 94 to seal off the upper half of cylinder 84 and begin compressing the gases therein. As piston head 82a reaches its upper deadpoint, the piston skirt 82b exposes intake ports 92 (as shown in FIG. 6b) when the vacuum has reached substantially its greatest value. Air (in the case of diesel engines) or a fuel/air mixture (for electricaly ignited engines) is immediately drawn into and fills the lower half of cylinder 84, from any suitable source, such as air filter 96.
Essentially simultaneously, the piston assembly 82 is reaching its upper deadpoint and gases in the upper half of cylinder 84 are compressed to their maximum density. Thus, when the piston 82 reaches its upper deadpoint, diesel fuel (in the case of a diesel engine) or an electrical spark (in the case of electrically ignited engines) is introduced into the compressed gases at which time the charge ignites, forcing piston assembly 82 downwardly. The piston skirt 82b quickly closes intake ports 92 and the downwad motion of the piston compresses the air or fuel/air mixture in the lower cylinder substantially as described with reference to FIGS. 1a-c.
Thus, as the piston assembly 82 travels downwardly, a point is reached where the pressures in the upper and lower halves of cyliinder 84 are in substantial equilibrium. At this point, the air or air/fuel mixture compressed in the lower half of cylinder 84 is forced through piston passage 24, opening membrane valve 96 which may comprise any of the valve assemblies discussed with reference to FIGS. 2-5. When the piston nears its lower deadpoint, exhaust ports 94 are exposed and the burned gases in the upper half of cylinder 84 escape through exhaust passage 98. As explained generally with reference to FIGS. 1-5, the incoming flow enhances evacuation of burned gases from the upper half of cylinder 84 by driving them out through the exhaust ports 94 shown by arrows 100. The upper portion of the cylinder is therefore substantially filled with fresh air or air/fuel mixture when the compression cycle begins again.
Shaft 90 may be connected to piston assembly 82 by any convenient means whereby access is provided for the compressed charge in the lower cylinder to pass through the piston and into the upper cylinder. Advantageously, shaft 90 may be formed with a two-armed connector (as shown in FIG. 6a ) or a four-armed connector (as shown in FIG. 7), having intake passages 93 to allow air and/or fuel free access to upper piston cavity 24. Thus, shaft 90 may be attached to the bottom of piston 82 by any convenient means, such as by bolts 94.
Advantageously, the membrane valve system used in such engines as shown in FIGS. 6a-b may be any of those described with reference to FIGS. 5a-d. However, if the engine operates according to the diesel principle, piston head 52 may advantageously be formed with a substantially flat top and dispensing ports 57a and 57b may be formed with a radially outward slant such that incoming flow 100 is directed away from exhaust ports 94. Accordingly, piston 82 may travel high within cylinder 84 as shown in FIG. 6b, to generate the high compression required by diesel engines.
This aspect of the present invention is particularly useful when employed by two-cycle engines of large power plants such as marine engines, since it provides an unusually simple two-cycle engine which requires much less valuable space than currently used engines. Moreover, large engines utilizing the present invention are much less complicated -- and therefore less expensive -- to fabricate, assemble and maintain. Furthermore, currently used large two-cycle engines, particularly those adapted for marine application, require very expensive turbo blowers activated by the escaping exhaust to force feed air into the cylinder in order to generate the required compression. However, the present invention obviates the need for such expensive, space consuming and power reducing apparatus. Accordingly, large engines according to the present invention require less space, are less expensive, "steal" less power and are less susceptible to breakdown than any heretofore known.
It will be appreciated by those skilled in the art that certain modifications can be made in the two-cycle engine as described above without departing from the spirit and scope of the invention as defined in the appended claims.
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An improved two-cycle internal combustion engine with a novel intake, exhaust and piston arrangement in which a fresh charge for combustion is advantageously transferred through the piston and all valves in the engine operate in response to changes in dynamic pressure generated within the engine. The piston includes at least one charging passage through its top surface with a pressure sensitive valve affixed to the top surface of the piston for preventing flow of a fresh charge through the charging passage in the absence of a greater pressure differential caused by the intake charge against the undersurface of the pressure sensitive valve. Advantageously, the pressure sensitive valve is deflected upwardly to provide passage of a charge through the charging passage in the presence of a sufficient pressure differential caused by the intake charge against the undersurface of the pressure sensitive valve, and the charging passage and pressure sensitive valve coact to direct flow of the incoming charge toward the walls of the engine cylinder away from the exhaust. Also advantageously, the intake and exhaust can be directly controlled by the piston.
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BACKGROUND OF THE INVENTION
This invention relates to measurement of electrical signals in power generating equipment and in particular to a method and apparatus for accurately determining negative sequence currents indicative of power oscillations in a multi-phase dynamoelectric machine.
A multi-phase dynamoelectric machine such as a three-phase steam turbine-driven generator used to produce electric power is designed to operate at constant power output and with equal currents in each of the phase lines. At times, however, imbalance of the external load results in power oscillations which yield unbalanced currents in the phase lines. These oscillations and unbalanced currents, in addition to producing temperatures in excess of design levels in one or more stator windings, also produce a non-symmetrical magnetic flux field across the air gap between rotor and stator. This field can be regarded as the sum of two fields, one, the primary, rotating with the rotor and the other rotating in the reverse direction, or in negative sequence. The negative sequence field in turn produces pulsating torques in the rotor shaft and stator core typically at twice the generator operating, or synchronous, frequency of 60 Hz. Although the amplitude of the pulsating torques may be small compared with total shaft torque, their frequency of about 120 Hz may be close to the natural frequencies of certain components of the turbine-generator assembly, and in particular to the natural frequency of certain buckets or blades of the turbine rotor which drives the generator rotor by means of an interconnecting shaft. Thus, the bucket vibrations and other motions which develop as a result of the pulsating torques can become appreciable, leading to bucket damage, for example to fatigue failure of bucket tie wires.
In order to assess the effects of negative sequence current on turbine buckets and other turbine-generator components and to implement procedures to avoid or correct for them, accurate determination of negative sequence current level is required. While devices for measuring these currents are presently in use at power stations, the negative sequence currents obtained are values averaged over considerable time intervals. Moreover, in part because measurement of negative sequence current typically involves determination of a small difference between two large signals, the values obtained by prior art devices are not sufficiently precise to convey all the information required for assessing and controlling bucket motions.
Accordingly, it is an object of the invention to provide a method and apparatus for accurately determining a negative sequence signal indicative of power oscillations in a multi-phase generator.
It is a more particular object of the invention to provide a method and apparatus for providing continuous, accurate values of negative sequence current in a three-phase turbine-driven generator.
SUMMARY OF THE INVENTION
A method and apparatus are provided for determining a negative sequence signal indicative of power oscillations in a multi-phase dynamoelectric machine. In a preferred embodiment of the invention, a negative sequence current circuit for a three-phase turbine-driven generator includes a signal conditioner for adjusting the amplitudes of three signals representative of the currents in phase lines of the generator to form a set of conditioned signals whose sum is zero, a phase-shifter network to shift the phase of a preselected conditioned signal of the set precisely 120 degrees, and an amplifier network for subtracting the phase-shifted signal from another conditioned signal of the set and applying a gain coefficient to yield the desired negative sequence current. Precise adjustment of signal amplitudes and phase angles is assured by the use of matched resistors and null balancing relationships in the negative sequence current circuit, which permits accurate calculation of negative sequence current as the difference between two large quantities.
BRIEF DESCRIPTION OF THE DRAWINGS
While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter regarded as the invention, the invention will be better understood from the following description taken in connection with the accompanying drawings in which:
FIG. 1 shows a circuit for determining negative sequence current according to the present invention; and
FIG. 2 is a plot indicating in phasor representation three line currents expressed as the sum of components of three sequence currents.
DETAILED DESCRIPTION OF THE INVENTION
As illustrated in FIG. 1, which shows a preferred embodiment of the negative sequence current circuit of the invention, three phase lines 20, 22, and 24 emanate from wye-connected power generator 26 and carry line currents I A (t), I B (t), and I C (t) for transmission to an external load (not shown). A neutral line 28, shown dashed, may also be provided. Neutral line 28, if included, carries a current I 0 (t), which for generating systems in which the portion of neutral line 28 within power generator 26 is connected to ground through a high impedance, will be very small or essentially zero compared to the three line currents I A (t), I B (t), and I C (t).
The line currents I A (t), I B (t), and I C (t) may be considered components of the line current phasor set I(t) shown in FIG. 2a, and each may be written as the sum of components of three currents known as sequence currents. These sequence currents, whose phasor representation is indicated in FIG. 2, are (1) the positive sequence current I + (t), which comprises three equally spaced components of equal magnitude which rotate counterclockwise on a phasor plot (FIG. 2b); (2) negative sequence current I - (t), the determination of the value of which is an important objective of the invention, which comprises three equally spaced components of equal magnitude which rotate clockwise (FIG. 2b); and (3) the zero sequence current I 0 (t), which comprises three identical components which rotate counterclockwise (FIG. 2d). The algebraic relationship between the line current I(t) and the sequence currents I + (t), I - (t), and I 0 (t) is indicated in FIG. 2.
Under ideal conditions of power generation and loading, the line currents have equal amplitudes and are equally spaced 120° apart in phase angle, and the negative sequence current is zero. However, when an imbalance occurs between the power generated and the external load, power oscillations and small amplitude and phase angle shifts occur in I A (t), I B (t), and I C (t), leading to nonzero negative sequence currents and pulsating torques at frequencies near the natural or resonant frequencies of certain turbine buckets. By application of Kirchhoff's Law for the sum of currents at terminal 30 of power generator 26 to the line currents I A (t), I B (t), and I C (t) expressed in terms of the three sequence currents, it can readily be shown by mathematical reduction that each component of the negative sequence current I - (t) is equal, except for a multiplier, to the difference between one line current and a second line current phase-shifted 120 degrees. Thus in algebraic form, each component of I - (t) is of the form
I.sub.- (t)=[I.sub.A (t)-I.sub.B (t-1/3f.sub.0)]/√3 (Eq. 1)
where F 0 is the synchronous line frequency, typically 60 Hz. The other components of negative sequence current i - (t ) may also be expressed by equations identical to Equation 1 above except for the substitution for the subscripts (A,B) the combination (B,C) or (C,A), which, as discussed in more detail below, permits a check on the accuracy of the negative sequence current circuit of the invention.
Accurate determination of the magnitude of the negative sequence current, as is required to correctly assess turbine bucket resonances, is difficult to achieve in term of the difference between one line current and a second current shifted 120 degrees as set forth in Equation 1 above because each component of negative sequence current I - (t) is typically a very small quantity compared with the large line currents (note that the phasors shown in FIG. 2 are not drawn to scale) and also because there is no readily available means in present measuring equipment to produce the required phase shift of exactly 120 degrees. Moreover, at power stations where it is desirable to monitor negative sequence currents, signals representing the line currents are available at voltage levels sufficiently low for safe measurement only through step-down current transformers which introduce small but unknown amplitude and phase shift errors in the line currents at the synchronous line frequency of 60 Hz.
The negative sequence current circuit of FIG. 1 includes features to overcome the above-mentioned problems and permit accurate and continuous calculation of negative sequence current. Lines 20, 22, 24 and 28 emanating from power generator 26 carry current signals I A , I B , I C , and I 0 , whose sum is zero according to Kirchhoff's Law (for convenience, reference to the time dependence of all current signals has been omitted here and in the remaining discussion). Transformers 32, 34, and 36 step-down the voltages of signals I A , I B , and I C to safe measurement levels, producing a set of current signals I A ', I B ', and I C ' representative of the line currents but including small unknown amplitude and phase shift errors such that the sum of signals I A ', I B ', I C ', and I 0 may be nonzero and thus not satisfy a key step in the derivation of Equation 1. However, if the assumption is made that transformers 32, 34, and 36 all produce the same phase angle shifts at 60 Hz, then signals I A ', I B ', and I C ' may be readjusted to again sum to zero by signal conditioner 38. Signal conditioner 38 includes an adjustment network comprising potentiometers 39, 40, and 41 by which signals I A ', I B ', and I C ' each can be multiplied by a factor close to unity, and resistors 42, 43, and 44, whose resistances are typically many times the resistance of potentiometers 39, 40, and 41 in order to limit the range of signal adjustment provided thereby. The conditioned signals I A ", I B ", and I C " produced by the adjustment network are added by means of resistors 45, which are selected to provide closely matched resistances (e.g., to ±0.01 percent) over the expected ambient temperature range of the negative sequence current circuit. By suitable adjustment of potentiometers 39, 40, and 41, signals I A ", I B ", and I C " may be varied to produce a voltage of zero at point 46. (If signal I 0 is available, it may also be added through resistor 48 to generate the voltage at 46 although, as mentioned previously I 0 is typically of negligible magnitude).
When zero voltage is obtained at point 46, the set of conditioned signals I A ", I B ", and I C ", with respect to accurately representing the line currents I A , I B , I C , include equal phase angle errors and small amplitude errors, but satisfy the relationship I A "+I B "+I C "+I 0 =0. The equal phase errors are unimportant in determination of the magnitude of negative sequence current, and the small amplitude errors, although ulimately resulting in some error in the negative sequence current calculated, produce error on a percent basis, i.e., a one percent error in I A yields a one percent error in negative sequence current, not a one percent of I A error in negative sequence current.
In order to accurately shift the phase of a conditioned signal by 120 degrees, one of the conditioned signals is fed to phase-shifter network 50, the particular signal chosen (e.g., I B " in the operating mode illustrated in FIG. 1) determined by the selected position of switches 51, 52, and 53 of signal conditioner 38, the switches typically linked to form a three-pole, three-position switching device which, as explained more fully below, permits calculation of negative sequence current using any two of the three line current signals. Amplifier 54 of phase-shifter network 50, in cooperation with potentiometer 56, phase shift adjustment-limiting resistor 57, and capacitor 58, produces a signal phase angle shift of -120 degrees and a signal gain of unity, the closeness to unity determined by the matching accuracy of the resistance values of input resistor 60 and feedback resistor 62. Amplifier 63, in cooperation with potentiometer 64, phase shift adjustment-limiting resistor 65, and capacitor 66, produces a signal phase angle shift of +120 degrees, and a gain of unity as determined by matched input resistor 68 and feedback resistor 70. The output signals I B- " and I B+ " from amplifiers 54 and 63 are added to conditioned signal I B " by means of matched resistors 72. By suitable adjustment of potentiometers 56 and 64, which alter the phase but not the amplitude of signals I B- " and I B+ ", zero voltage may be attained at point 74. Then, since the only way three phasors (I B- ", I B+ ", and I B ") of equal nonzero amplitude can add to zero is if they are equally spaced 120 degrees from one another, the signal I B- " produced by phase-shifter network 50 must have, with respect to conditioned signal I B ", an equal amplitude and a phase angle shift of -120 degrees.
To complete the calculation of negative sequence current according to Equation 1 above, differential amplifier network 76 is provided. Amplifier 78 of network 76 receives conditioned signal I A " from signal conditioner 38 at a first input terminal and phase-shifted signal I B- " from phase-shifter network 50 at a second input terminal. The amplifier 78 subtracts I B- " from I A ", and also applies a gain of 1/√3 through appropriate choice of resistance values in resistors 80, 82, 84, and 86. Amplifier network 76 thus produces a negative sequence current signal equal to the quantity (I A "-I B- ")/√3.
Also included in the negative sequence current circuit of FIG. 1 is 60 Hz bandpass filter 88, which may be connected by means of switch 90 to negative sequence current terminal 92, current balance terminal 94, or phase balance terminal 96. Filter 88 permits removal of noise and other distortions such as the third harmonic (180 Hz) signal components which might otherwise interfere with accurate measurement of negative sequence current and with current and phase balance operations. Filter 88 may also include means to amplify the negative sequence current to supplement or substitute for the gain provided in differential amplifier network 76.
Switches 51, 52, 53 of signal conditioner 38 permit a check on the accuracy of the negative sequence current circuit by allowing calculation of negative sequence current using any two of the three line currents. These switches are preferably ganged for simultaneous switching between positions 1, 2, and 3, which respectively provide components of negative sequence current calculated from (I A ", I B- "), (I B ", I C- "), and (I C ", I A- "). Once the currents and phases have been balanced for one combination to produce zero voltages at points 46 and 74, the magnitude of negative sequence current determined at the output terminal 98 of filter 88 should be the same for each of the three positions 1, 2, and 3 of switches 51, 52, and 53.
In operation, line currents I A , I B , and I C from power generator 26 are fed through step-down transformers 32, 34, and 36. The resulting set of current signals I A ', I B ', and I C ' are conditioned by potentiometers 39, 40, and 41 which are adjusted (with switch 90 connecting filter 88 to current balance terminal 94) to yield conditioned signals I A ", I B ", and I C " which, together with current signal I 0 (if available), are summed to produce a zero voltage at point 46. With switches 51, 52 and 53 set, for example, in position 1, and switch 90 now connecting filter 88 to phase balance terminal 96, conditioned signal I B " is directed to amplifiers 54 and 63 of phase-shifter network 50. The phase-shifter network 50 produces two intermediate signals having phase shifts of approximately -120 degrees and +120 degrees with respect to conditioned signal I B " and amplitudes equal to that of I B ". The two intermediate signals are then summed with conditioned signal I B ", and the settings of potentiometers 56 and 64 are varied until the voltage at point 74 is zero, indicating a zero sum and the desired phase angle shifts of precisely -120 degrees and +120 degrees. The -120 degree phase-shifted current signal I B- " from amplifier 54 is then fed to amplifier network 76 which also receives as input the conditioned signal I A " from signal conditioner 38. With filter 88 now connected to negative sequence current terminal 92, amplifier 76 determines negative sequence current by calculating the quantity (I A "-I B- ")/√3 for output to terminal 98. To check the accuracy of the negative sequence current circuit, switches 51, 52, and 53 may be moved to position 2 shown in FIG. 1, which will result in the phase-shifting of signal I C " and calculation of negative sequence current as (I B "-I C- ")/√3, or to position 3, which will produce a negative sequence current calculated as (I C "-I A- ")/√3. For an accurate circuit, all three values of negative sequence current will be the same.
While there has been shown and described what is considered a preferred embodiment of the invention, it is understood that various other modifications may be made therein and it is intended to claim all such modifications which fall within the true spirit and scope of the invention.
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A method and apparatus are disclosed for accurately determining negative sequence current in a three-phase turbine-driven generator, the currents indicative of power oscillations and of torques harmful to turbine buckets. A signal conditioner and phase-shifter network are described which provide precise amplitude and phase angle adjustments and null balancing features which permit accurate determination of the magnitude of negative sequence current even though this current is a very small quantity determined as the difference between two large signals.
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BACKGROUND OF THE INVENTION
One type of electromechanical actuator for influencing sewing machine stitch patterns operates in association with a servo-system comparing input signals related to the stitch pattern being executed with reference signals related to the existing position of the actuator. A conventional potentiometer comprising a coil with a wiper having contact relatively movable along the coil and functioning as a voltage divider would involve distinct disadvantages when utilized to provide positional reference signals for such a sewing machine actuator. Wear occurring because of the contact between the parts can be troublesome, especially since extended periods of sewing machine operation occur in particular positions such as the straight stitch position and because of dither motions occurring in such frequently used positions the conventional potentiometer will wear quickly at certain points.
Those non-contact position sensing devices which are known for use other than in sewing machine applications, would not serve satisfactorily in place of the device of the present invention for one or more of the following reasons:
Known non-contact position sensing devices involve high inertia effects which would be detrimental to the effective operation of the electromechanical sewing machine actuator.
Known non-contact position sensing devices do not exhibit sufficiently linear response ranges.
Known non-contact position sensing devices generate objectionable radio interference.
The large size of known non-contact position sensing devices and the requisite shielding required with them would require inordinately large space and such devices would not be adapted for accommodation within the crowded space available within a sewing machine frame.
SUMMARY OF THE INVENTION
It is an object of this invention to provide a non-contact position sensing device usable with a sewing machine actuator which will have a linear response over the operating range of the actuator and will impose a minimal inertia effect upon the actuator. This object is attained by the provision of a shunt member shiftable in association with a sewing machine actuating member and arranged for movement relatively to a pair of coils. The arrangement is such that shift of the shunt member will change the induction of the coils due to eddy currents induced into the shunt member generating magnetic fields opposite to those generated by the coils.
The position sensing device of this invention is additionally advantageous as applied to an electromechanical actuator of a sewing machine because the device may be made very light in weight and small in size, and because the device has its greatest accuracy and stability in the mid-position corresponding to center middle position of a sewing machine actuator which position is frequently repeated.
DESCRIPTION OF THE DRAWINGS
With the above and additional objects and advantages in view, as will hereinafter appear, this invention comprises the devices, arrangements, and combinations of parts hereinafter described and illustrated in the accompanying drawing of a preferred embodiment in which,
FIG. 1 is a perspective view of a sewing machine including fragments of typical needle jogging and work feeding mechanisms each influenced by an electromechanical actuator which has a position sensing device in accordance with this invention applied thereto,
FIG. 2 is a front elevational view of the position sensing device of this invention,
FIG. 3 is a bottom view of the position sensing device shown in FIG. 2,
FIG. 4 is a schematic wiring diagram indicating a circuit adapted to respond to the signals generated by the position sensing device of this invention and
FIG. 5 is a graph indicating the linearity curve of the response of the position sensing device of this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Shown in phantom lines in FIG. 1 is a sewing machine 10 to which this invention is applied. The sewing machine includes a bed 11, a standard 12 rising from the bed and a bracket arm 13 overhanging the bed. The driving mechanism of the sewing machine includes an arm shaft 14 and a bed shaft 15 interconnected in timed relation by conventional drive mechanism (not shown). A needle 17 is carried for endwise reciprocation by a needle bar 18 mounted for lateral jogging movement in a gate 19 in the bracket arm 13. Any conventional connections (not shown) may be used between the arm shaft 14 and the needle bar for imparting needle reciprocation. A drive link 25 is pivoted as at 26 to the gate 19 and provides the mechanical connection to an electromechanical actuator indicated generally at 27.
Also illustrated in FIG. 1 is a fragment of a work feeding mechanism including a feed dog 34 carried by a feed bar 35. In FIG. 1 the mechanism is illustrated for imparting work transporting movement to the feed dog including the feed drive shaft 36 driven by gears 37 from the bed shaft, a cam 38 on the feed drive shaft, and a pitman 39 embracing the cam 38 and connected to reciprocate a slide block 40 in a slotted feed regulating guideway 41. A link 42 pivotably connects the pitman 39 with the feed bar 35 so that depending upon the inclination of the guideway 41, the magnitude and direction of the feed stroke of the feed dog will be determined.
The inclination of the guideway 41 in the present invention may be controlled by an electromechanical feed actuator indicated generally at 28. The electromechanical feed actuator 28 is connected to a link 46 pivoted at 47 to a rock arm 48 which is secured on a rock shaft 49 to which the guideway 41 is affixed.
The electromechanical actuators 27 and 28 may be constructed alike and may take the form of construction disclosed in detail in the U.S. patent application Ser. No. 431,649, filed Jan. 8, 1974 of Philip Minalga which is incorporated herein by reference. For an understanding of the present invention, the following brief description of the electromechanical actuator 28 should suffice.
The actuator 28 includes a U-shaped magnetically permeable yoke 113 which may be secured to the sewing machine frame by any suitable means. Secured to each of the two inner faces of the yoke is a permanent magnet 114. These magnets are magnetized across the small dimension so as to present the same polarity to the opposed inner faces thereof. A single center leg 115 of magnetically permeable material, positioned centrally between the magnets provides both a flux return path and a guide on which is slidably mounted a bobbin 118 carrying a winding. The bobbin is made of light-weight insulating molded plastic and is formed with lugs 119 which project externally through slots in a magnetically permeable cover plate 121.
The lugs 119 are pivotally connected to one end 124 of a lever 125 having a pivot shaft 126 secured thereto and journaled in lugs 127 of a pivot plate 128 secured to the cover plate 121 as by screws 129. The other end 130 of the lever 125 is pivotally connected to the link 46 which operates the feed regulator shaft 49.
As stated above, the electromechanical actuator 27 is constructed in the same manner as is the actuator 28 and therefore the actuator 27 includes a lever 125' which is carried on a pivot shaft 126' and which is connected to the drive link 25 for jogging the sewing machine needle.
As explained in detail in the above referenced co-pending U.S. patent application Ser. No. 431,649, filed Jan. 8, 1974, each of the electromechanical actuators 27 and 28 is influenced by an electrical servo-system which compares predetermined electrical pattern signals with reference signals indicative of the actual position of the actuator to drive the actuator successively into the pattern dictated positions. The position sensing device of this invention, which provides the reference signals indicative of the actual position of the actuator, will now be described.
In FIGs. 1 to 4 of the drawing, the position sensing device of this invention is indicated generally at 150, and since the position sensing devices utilized with the electromechanical actuators 27 and 28 are alike, the same reference characters will be used to denote similar parts thereof.
Supported as by a bracket 151 secured to the yoke 113 is a planar electrically non-conductive coil board 152 which may be generally rectangular in shape and which carries on its surface a pair of spaced electrically conductive coils 153-154 which are preferably mirror images of each other. One extremity of each of the coils is directed to a terminal 155 and 156, respectively, located one centrally of each of the coils. The other extremity of each coil is directed to a common terminal 157 equidistant from each of the coils. Preferably, the coils may be provided as printed circuit components deposited as a film on the surface of the coil board 152.
The bracket 151 supports the coil board perpendicular to the axis of the pivot shaft 126 of the actuator 28 (and perpendicular to the pivot shaft 126' of the actuator 27) and the pivot shaft 126 has fixed thereon a metallic shunt plate 160 which is preferably flat and arranged in spaced relation to the coil board 152.
The shunt plate 160 is formed as shown in FIG. 2 perfectly symetrical about a radius extending from the pivot shaft 126 and extends centrally of the shunt plate. The side edges 161 and 162 of the shunt plate preferably are straight and extend radially from the pivot shaft 126 although these side edges may be given any desired configuration albeit each being a mirror image of the other about the central radial line.
The shunt plate 160 is made of non-magnetic metal capable of eddy current conduction. In a prefered embodiment the shunt plate is formed of aluminum.
In the mid-position of the shunt plate as illustrated in FIG. 2, the shunt plate bears exactly the same relationship to each of the coils 153 and 154. In this position of parts, when the coils are excited (parallel driven) by the same exciting voltage, the inductance of each of the coils will be equal. When the pivot shaft 126 is turned in either direction, the attached shunt plate will move correspondingly covering a greater portion of one of the coils and causing the inductance of the covered coil to decrease in proportion to the extent of greater coverage by the shunt plate. This decrease in inductance is due to eddy currents induced into the shunt plate generating a magnetic field opposite to that generated by the coil itself. The change in coil inductance is very closely proportional to the area of coils covered by the shunt plate.
FIG. 4 illustrates a schematic electrical diagram of an arrangement of components which may be utilized with the position sensing device 27 or 28 to provide a sensor output voltage suitable for use in a servo-system required for operation of the sewing machine of FIG. 1. Indicated at 120 in FIG. 4 is a conventional pulse generator capable of generating a square wave pulse train with a particularly steep rise. Coil 153 has its terminal 155 connected through isolating resistor 170 to the output line 171 of generator 120. Coil 154 has its terminal 156 connected through isolating resistor 172 to the output line 171. The common terminal 157 is connected to ground 173 which is common to the grounded side of the generator 120.
Terminal 155 is connected through diode 174 to one terminal 175 of a differential amplifier 176. Resistor 177 provides the load for diode 174, and capacitor 178 filters out the high frequency components.
Similarly, terminal 156 is connected through diode 179 to the other terminal 180 of the differential amplifier 176. Resistor 181 provides the load for diode 179, and capacitor 182 filters out the high frequency components.
The differential amplifier 176 is a conventional operational amplifier having gain controlling resistors 183, 184, 185 and 186 connected to provide a differential input at terminals 175 and 180 and a single ended output at terminal 187 in a manner well known in this art.
In operation, the reactive voltage generated in coil 153 is substantially equal to L 1 (di/dt) where L 1 , is the inductance of coil 153 and (di/dt) is the rate of change of current in the coil due to the driving square pulse wave applied thereto. After rectification by diode 174, the resultant voltage at terminal 175 is K D L 1 -D 1 where K D is the driving function determined by the driving voltage magnitude and rise time, and D 1 is the voltage drop in diode 174. Similarly, the voltage at terminal 180 is K D L 2 - D 2 where L 2 is the inductance of coil 154 and D 2 is the voltage drop in diode 179.
As is well known, the differential amplifier 176 produces on output terminal 187 a voltage E o equal to the difference between the input voltages on terminals 175 and 180 multiplied by the amplifier gain K A .
Thus
E.sub.o = K.sub.A [(K.sub.D L.sub.1 -D.sub.1) - (K.sub.D L.sub.2 -D.sub.2)]
or
E.sub.o = K.sub.D K.sub.A (L.sub.1 -L.sub.2) - (K.sub.A) (D.sub.1 -D.sub.2)
where:
E o = Position sensor output voltage
K D = Driving Function
K A = Amplifier gain
L 1 , L 2 = Printed coil inductance
D 1 , D 2 = Diode voltage drop
At the center position:
L.sub.1 = L.sub.2
therefore:
E.sub.o.sup.3 = K.sub.A (D.sub.1 - D.sub.2)
note that in the center position, E o is not a function of K D which possesses the highest temperature sensitivity because it is determined by the driving voltage rise time and magnitude, and to a lesser degree, frequency. This is especially advantageous in the sewing machine of FIG. 1. Center position accuracy of the actuators 27 and 28 is of prime importance because, for instance, in straight stitch operation (center position) a small throat plate needle aperture provides minimal clearance for the needle. Needle positioning error in this mode of operation could cause the needle to come down on the throat plate, causing the needle to break and possibly injure the operator. Needle positioning error during pattern stitching by comparison is far less serious causing only stitch pattern distortion or offset.
The diode voltage drops D 1 and D 2 track well with temperature, and any initial offset can be nulled by the conventional system offset adjustment.
In the off center position, K D comes into play and has a maximum effect at full scale. It has been found that using this invention a maximum of + 10% of point error over a temperature range of +25°F to + 125°F, should be expected at full scale.
The movable shunt plate 160 may be very small having a surface area of about 1 square inch. Formed of aluminum, the moving mass is exceedingly small resulting in negligible mechanical loading or inertia effect upon the operation of the electromechanical actuator.
Interference generated by the coils 153 and 154 is not detectable a short distance away even without shielding because the fields generated by the coils are in opposition.
The compactness of the position sensing device of this invention is suited admirably to incorporation within the close confines of a sewing machine frame.
The output characteristic of the position sensing device of the preferred form of this invention is shown in FIG. 5 and is fully compatible with the requirements for such a device as used in the copending U.S. patent application Ser. No. 431,649, Jan. 8, 1974.
The linearity of this sensing device is related to the change in coil inductance responsive to the position of the metallic vane and can be made very accurate by close attention to the symmetry of coil and vane geometry about a center zero position.
A magnetic preferrably non-metallic shunt plate may be used with this invention and will produce an acceptable output which is the mirror image of that depicted in FIG. 5. The higher cost and increased mass of a magnetic shunt plate, however, are factors which are instrumental in the choice of a non-magnetic metallic shunt plate on the preferred embodiment.
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A sewing machine is disclosed having electromechanical actuators for controlling the stitch forming instrumentalities in the formation of stitch patterns with a non-contact position sensing device associated with each electromechanical actuator comprising spaced coils and a metallic shunt plate arranged adjacent and shiftable relatively to the coils in response to movement of the actuator to produce a measureable variation in the inductance of the coils which bears an advantageous linear relationship to the electromechanical actuator position.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates, generally, to devices having utility for target practice. More particularly, it relates to a versatile device that has multiple configurations to challenge the shooter.
2. Description of the Prior Art
Stationary targets have utility for target practice but moving targets provide a greater challenge to the shooter.
Targets that rotate in a vertical plane about a horizontal axis are well known. To make such a target more challenging, U.S. Pat. No. 1,488,647 discloses such a target which is masked by a stationary wall having an arcuate window formed therein. The curvature of the window matches the curvature of the rotating target. Accordingly, the target is seen only briefly by the shooter as it passes behind the window.
There are also multiple patents that disclose amusement park devices that present multiple small moving targets to a shooter that fold away from the shooter when struck with a pellet or other low power projectile. Each target returns to its upright position of repose shortly after having been struck by a low power projectile.
A common characteristic of prior art devices in this field is that they have a single configuration, i.e., they present a particular challenge to a shooter and cannot be modified to present a different challenge to the shooter. The shooter thus tires of the device for the same reason that shooters tire of stationary targets.
Another common characteristic of the prior art devices is that they are essentially indestructible because they are made with materials that are substantially impervious to low power projectiles and therefore can be struck with projectiles thousands of times with little or no deterioration.
Professional civilian, law enforcement, military and private indoor and outdoor gun ranges throughout the U.S. include targets and target backgrounds made of corrugated or fluted cardboard, fiberboard, heavy-duty layered stock paper, single and mufti-ply paper and paper decals as a part of standard practice, procedures and safety standards.
There is a need for an apparatus that exhibits a high level of versatility so that it can be configured into multiple configurations, each of which offers a high degree of challenge to a shooter.
There is also a need for a target practice apparatus where low, medium and high-power projectiles may be used and which has targets made of low cost materials which are eventually destroyed by the projectiles after extended use and which are then easily replaced.
However, in view of the art considered as a whole at the time the present invention was made, it was not obvious to those of ordinary skill in the art how the needed target practice apparatus could be provided.
SUMMARY OF THE INVENTION
The long-standing but heretofore unfulfilled need for an improved target practice device is now met by a new, useful, and non-obvious invention.
The novel target practice apparatus is adapted to receive projectiles fired at it by a remotely positioned shooter. It includes at least one motor having an output shaft, a housing for the motor and a motor housing post secured to the motor and the motor housing. A target disc is releasably secured to the output shaft for conjoint rotation therewith.
A base supported by a floor, the ground, or other support structure holds a vertical column of hollow construction. In a first embodiment, the motor housing post is slideably received within the hollow interior of the vertical column in differing orientations so that the output shaft of the motor may be positioned parallel to the path of travel of a projectile fired at a target disc that rotates conjointly with the output shaft of the motor or perpendicular to said path of travel. In the former orientation, the target disc faces the shooter and in the latter orientation, the target disc is positioned on edge relative to the shooter.
A frame supports the motor housing and the target disc. An L-shaped elbow member is releasably attachable to the frame in a plurality of differing configurations. The motor housing post is also releasably attachable to the frame in a plurality of differing configurations. The motor housing post is releasably attachable to the L-shaped elbow member as well in a plurality of differing configurations.
The target disc is disposed in a vertical plane in a first configuration of the apparatus and is rotatable about a horizontal axis of rotation. The horizontal axis of rotation is substantially parallel to a path of travel of a projectile fired by the remote shooter and aimed at the target disc. The target disc is substantially perpendicular to the path of travel.
In a second configuration of the apparatus, the target disc is disposed in a vertical plane and is rotatable about a horizontal axis of rotation. The horizontal axis of rotation is substantially perpendicular to a path of travel of a projectile fired by the remote shooter and aimed at the target disc. The target disc is positioned in a plane that is substantially parallel to the path of travel.
The target disc is disposed in a horizontal plane and is rotatable about a vertical axis of rotation in a third configuration of the apparatus. The vertical axis of rotation is substantially perpendicular to a path of travel of a projectile fired by the remote shooter and aimed at the target disc. The target disc is positioned in a plane that is substantially parallel to the path of travel.
At least one target tab is connected to the target disc and is foldable so that it extends therefrom at about a ninety degree angle thereto when the target disc is in the second or third configuration where the target disc is seen on edge.
A non-rotating blocker disc is disposed in closely spaced, parallel relation to the target disc when the target disc is in its first configuration. The non-rotating blocker disc has a size and shape substantially similar to a size and shape of the target disc. At least one window is formed in the non-rotating blocker disc so that the target disc is visible to the shooter through the at least one window. At least one target decal is applied to the target disc so that the target decal is visible to the shooter through the window for each revolution of the target disc about its axis of rotation.
The frame includes an upstanding hollow tube or vertical column of telescopic construction so that its height may be varied. An L-shaped elbow member has a first leg slideably connected to the vertical column in axial alignment with the vertical axis of symmetry of the upstanding tube. A second leg of the L-shaped elbow member is disposed at a ninety degree angle relative to the first leg and at a ninety degree angle to the vertical axis of symmetry of the vertical column.
The motor housing post may be connected to the second leg to position the target disc in a plane perpendicular to a path of travel of a projectile fired at the target disc or it may be connected to the second leg to position the target disc in a plane parallel to a path of travel of a projectile fired at the target disc, said parallel plane causing said target disc to be seen on edge by a shooter and requiring bending of at least one of said target tabs relative to the plane of the target disc.
Still further embodiments include a horizontally-extending platform arm connected to the vertical column. Rotating target discs may be mounted to either or both ends of the platform arm in perpendicular or parallel relation to the shooter to increase the number and complexity of the targets available to the shooter.
The target discs as well as the blocker discs and blocker boards are made of various types of paper or other suitable material so that projectiles pierce through them and do not ricochet therefrom and so that they are gradually destroyed by repeated hits by such projectiles. Each target or blocker disc is therefore formed of inexpensive and readily available paper. Removal of destroyed target and blocker discs and their replacement with new discs requires very little time. Each disc is centrally apertured and is easily slipped onto an output shaft of a motor.
These and other important objects, advantages, and features of the invention will become clear as this disclosure proceeds.
The invention accordingly comprises the features of construction, combination of elements and arrangement of parts that will be exemplified in the disclosure set forth hereinafter and the scope of the invention will be indicated in the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
For a fuller understanding of the nature and objects of the invention, reference should be made to the following detailed disclosure, taken in connection with the accompanying drawings, in which:
FIG. 1A is a front elevation view of a target disc having unfolded target tabs secured thereto about its periphery;
FIG. 1B is a front elevation view of the structure depicted in FIG. 1A but with the target tabs folded;
FIG. 1C is an end elevation view of the structure depicted in FIG. 1B ;
FIG. 1D is a front elevation view of a blocker disc prior to removal of its perforated windows;
FIG. 1E is a front elevation view of the blocker disc when positioned in blocking relation to the rotating target disc and after removal of the perforated sections to form windows in said blocker disc;
FIG. 2A is a front elevation view of the novel assembly when configured to have one rotating target disc and associated non-rotating blocker disc in a front vertical configuration;
FIG. 2B is a top plan view of the parts depicted in FIG. 2A ;
FIG. 2C is a side elevation view of the parts depicted in FIGS. 2A and 2B ;
FIG. 3A is a front elevation view when the novel assembly is configured to display two rotating target discs and their associated non-rotating blocker discs in lateral relation to one another in a front vertical configuration;
FIG. 3B is a top plan view of the parts depicted in FIG. 3A ;
FIG. 4A is a front elevation view of the novel assembly when configured to display three rotating target discs and associated non-rotating blocker discs in a front vertical configuration;
FIG. 4B is substantially the same as FIG. 4A but with the rotating and non-rotating discs attached;
FIG. 5A is a front elevation view of the novel assembly when configured to display four (4) sets of rotating target discs and associated non-rotating blocker discs in front elevation relative to a shooter;
FIG. 5B is substantially the same view as FIG. 5A but with the rotating target discs and non-rotating blocker discs attached;
FIG. 5C is a top plan view of the structure depicted in FIG. 5B ;
FIG. 6A is a front elevation view of the novel assembly when two laterally disposed rotating target discs are disposed in end vertical configuration relative to a shooter, there being no non-rotating blocker discs in such configuration;
FIG. 6B is a top plan view of the structure depicted in FIG. 6A ;
FIG. 7A is a front elevation view of the novel assembly when two laterally disposed rotating target discs are disposed in end horizontal configuration relative to a shooter, there being no non-rotating blocker discs in such configuration;
FIG. 7B is a top plan view of the structure depicted in FIG. 7A ;
FIG. 8A is a front elevation depicting a configuration of the novel parts when one (1) target disc is used;
FIG. 8B is a front elevation depicting a configuration of the novel parts when one (1) target disc is used;
FIG. 8C is a front elevation depicting a configuration of the novel parts when one (1) target disc is used;
FIG. 9A is a front elevation depicting a configuration of the novel parts when two (2) target discs are used;
FIG. 9B is a front elevation depicting a configuration of the novel parts when two (2) target discs are used;
FIG. 9C is a front elevation depicting a configuration of the novel parts when two (2) target discs are used;
FIG. 10A is a front elevation depicting a configuration of the novel parts when three (3) target discs are used;
FIG. 10B is a front elevation depicting a configuration of the novel parts when three (3) target discs are used;
FIG. 10C is a front elevation depicting a configuration of the novel parts when three (3) target discs are used;
FIG. 11A is a front elevation depicting a configuration of the novel parts when four (4) target discs are used;
FIG. 11B is a front elevation depicting a configuration of the novel parts when four (4) target discs are used;
FIG. 11C is a front elevation depicting a configuration of the novel parts when four (4) target discs are used;
FIG. 12A is an exploded perspective view of the frame assembly;
FIG. 12B is an assembled perspective view of the parts depicted in FIG. 12A ; and
FIG. 12C is a plan view of the base assembly.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Novel system 10 is a modular, expandable shooting target arcade system that can be configured into a large plurality of configurations to offer a large number of shooting challenges. System 10 is compact and portable and can be used indoors and outdoors. Its targets are expendable because they are destroyed after repeated usage.
Novel system 10 improves basic firearm shooting skills for shooters of primer cartridges, rim fire cartridges, black powder, metal pellets, plastic pellets for AIRSOFT® shooting-related sports, BB and all other types and brands of ammunition for hand guns and rifles, projectiles launched from slingshots as well as arrows used by bows and crossbows in archery sports.
Primary components of the rotating target system are formed from plastic tubing, corrugated cardboard, corrugated or dense flat paper board, heavy-duty layered stock paper and single or multi-ply paper. These paper materials provide an intrinsic safety feature because they are ricochet-resistant. The paper also allows high velocity bullets, pellets or BBs that miss the paper target and strike the blocker disc, rotating target disk or the body of the target system to pass through the paper. All projectiles pass cleanly through the paper target material.
The use of these materials provides easy, rapid and inexpensive replacement of parts by the on-scene user without need for special tools or extensive training and helps mitigate “down-time” thus providing more time to actively shoot.
The various parts of the novel system that may be subject to damage if struck by higher velocity projectiles include small electric motors, portable batteries, battery housings, electrical conductors, screws, nuts and a plastic or cardboard handle. These items are preferably positioned at respective maximum distances from the targets.
FIG. 1A depicts an illustrative embodiment of rotating target disc 12 a . In this particular example, disc 12 a is flat and has an octagonal shape although such shape could be circular as its name implies, i.e., disc 12 a may be provided in any predetermined geometrical configuration.
In this example, four (4) paper target decals, collectively denoted 14 , are secured to disc 12 a in circumferentially and equidistantly spaced apart relation to one another. Target decals 14 may be provided in any shape or size and in any random orientation, not just the orderly orientation depicted.
Target tabs 16 are depicted in FIG. 1A as being coplanar with disc 12 a but said target tabs are not used in that configuration. They are first releasably attached to disc 12 a by inserting tabs 17 into tab-receiving cut-outs formed in disc 12 a as depicted in said FIG. 1A , said cut-outs being clearly depicted and not numbered to avoid clutter.
At least one target tab is then folded along folding line 16 a so that it is perpendicular to the plane of disc 12 a as indicated in FIGS. 1B and 1C . A second fold is then made along folding line 16 b . Tab 17 is removed from its cut-out and fit into slot 17 a formed in said disc 12 a . As best understood by comparing FIG. 1B with FIG. 1C , two (2) tabs are mounted so that a first tab extends perpendicularly in a first direction relative to the plane of target disc 12 a , and a second tab extends perpendicularly in a second, opposite direction. Target tabs 16 remain flat when disc 12 a is in its FIG. 1A or 1 B position, i.e., when disc 12 a lies in a plane substantially perpendicular to the shooter's line of sight, i.e., substantially perpendicular to the path of travel of each projectile fired by the shooter.
As depicted in FIG. 1C , target tabs 16 are needed when disc 12 a is parallel to the shooter's line of sight so that only the edge of disc 12 a can be seen. Although not depicted, target decals 14 are also attachable to target tabs 16 although some shooters may elect to use each tab 16 as a whole as a target in view of its relatively small size. Shooters may elect to place target decals on either the front or reverse sides, or both, of target tabs 16 because disc 12 a can be controlled to rotate in either direction.
The three (3) apertures in the center of disc 12 a in FIGS. 1A and 1B are collectively denoted 12 c . The center aperture receives the output shaft of a DC motor that rotates disc 12 a and the outlying apertures are used to mount disc 12 a to a support member disclosed hereinafter.
System 10 further includes at least one non-rotating, blocker disc 12 b , depicted in FIG. 1D . Blocker disc 12 b is mounted in front of rotating target disc 12 a , in spaced apart, parallel relation thereto, when said disc 12 a is oriented in the facing-the-shooter position of FIGS. 1A and 1B so that the shooter cannot see rotating target disc 12 a . Blocker disc 12 b serves no purpose and is not used when disc 12 a is in its FIG. 1C on-edge position relative to the shooter.
Both discs 12 a and 12 b are formed, preferably, of corrugated or fluted cardboard (also known as fiberboard), cardstock, poster board and single or multiple ply paper of various thickness and density depending on the application and type and caliber of projectiles used.
Rotating target disc 12 a and non-rotating blocker disc 12 b may be provided in any predetermined geometrical shape such as circular but the depicted octagonal shape is preferred. It is also preferred that blocker disc 12 b have the same shape and size as rotating target disc 12 a but blocker disc 12 b could be made of a shape and size that differs as long as it performs its function of blocking rotating target disc 12 a from the shooter's view. Each disc 12 a and 12 b is pre-notched, pre-cut, pre-slotted and pre-drilled to facilitate its use.
Perforation lines 18 in FIG. 1D enable a user to easily remove at least one or any other quantity of the cardboard areas surrounded by said perforation lines. When a surrounded area is punched out, a window is formed in said blocker disc 12 b . The windows may be of any quantity, size and shape, but they must be positioned so that at least one decal target 14 on rotating target disc 12 a becomes visible when it rotates past a non-rotating window.
FIG. 1E differs from FIG. 1D in that the perforation-surrounded areas have been removed to form windows 20 in blocker disc 12 b , thereby revealing parts of rotating target disc 12 a and revealing each target tab 14 when such tab rotates behind a stationary window 20 . Windows 20 provide temporary visual exposure of decal targets 14 to the shooter as said decal targets travel with rotating target disk 12 , i.e., windows 20 provide brief opportunities for the shooter to shoot a target decal 14 through a window. The target reappears on the following revolution of rotating target disc 12 , affording the shooter the opportunity to check the accuracy of the previous shot as well as the opportunity to resume shooting.
It is within the scope of this invention to provide a blocker disc 12 b having only one (1) window 20 formed therein but the preferred embodiment has multiple windows and one (1) or any other number of them may be punched out/removed from the blocker disc, depending upon the selection of the user. From the shooter's view point, windows 20 cause the rotating decals 14 to momentarily appear when aligned with a window and to disappear as rotating target disc 12 a continues to rotate, thereby closing each window of opportunity for the rotating decal 14 to be hit with a projectile.
In the illustrative embodiment of FIGS. 2A , 2 B, and 2 C, discs 12 a and 12 b are mounted to the uppermost end of vertical support column 11 which is hollow and preferably square in transverse section, and preferably of telescoping construction as well so that its vertical extent is adjustable. Vertical, telescoping columns that may be locked into any preselected position of height adjustment are well-known so the locking means is not depicted in order to avoid needless cluttering of the drawings. The lowermost end of vertical column 11 is mounted to base 13 which may take any well-known form. In this particular example, base 13 has a plus-sign (+) shape when viewed in the plan view of FIG. 2B .
Both discs 12 a and 12 b are apertured as at 12 c as mentioned and as illustrated in FIGS. 1A-E to enable attachment of said discs to plastic, polycarbonate or wooden mounting disc 26 a ( FIG. 2A , disc 12 a ) and blocker arm 28 ( FIG. 2B , disc 12 b ).
Platform 15 is centrally apertured to slidingly receive vertical support column 11 and is lockable to said vertical column at any preselected position by suitable locking means. Spacer 15 a adjacent platform 15 is best understood by comparing the side elevation view of FIG. 2C with the front and top views of FIGS. 2A and 2B . It secures blocker arm 28 against rotation as best understood in connection with said FIG. 2C .
The output shaft of DC motor 24 is denoted 24 a in FIGS. 2A and 2B and its housing is denoted 24 b in FIG. 2B . Housing 24 b also houses a battery, a battery holder, wiring, toggle switches and the electrical connectors that interconnect the battery to said DC motor.
Motor mounting post 25 is formed integrally with motor 24 and motor housing 24 b . Said post 25 is releasably and slideably received within the uppermost end of hollow vertical column 11 as depicted in FIGS. 2A-C so that target and blocker discs 12 a and 12 b are facing the shooter. Said post could be rotated about its vertical axis in either direction ninety degrees (90°) to present target 12 a on edge. Blocker disc 12 b is not used when target disc 12 a is presented on edge to the shooter.
Moreover, an elbow member having two hollow parts disposed at a ninety degree (90°) angle to one another, disclosed hereinafter and not depicted in FIGS. 2A-C , may also be releasably and slideably received within said hollow vertical column 11 in differing orientations. Motor housing post 25 may be releasably and slideably received with the respective hollow interiors of said elbow parts, thereby providing a large number of possible configurations for the target and blocker discs.
The output shaft of motor 24 is denoted 24 a in FIGS. 2A , 2 B, and 2 C. Circular mounting member 26 a , preferably of polycarbonate construction, is mounted on said output shaft 24 a for conjoint rotation therewith. There are two (2) diametrically opposed openings for screws formed in polycarbonate mounting member 26 a , radially outwardly of output shaft 24 a , and said screw openings are clearly depicted but are not numbered in order to avoid clutter. The center aperture of the three (3) apertures denoted 12 c in the center of rotating target disc 12 a is placed into registration with output shaft 24 a and said two (2) screw openings are aligned with the two (2) apertures that flank said central opening when disc 12 a is secured to mounting member 26 a with a pair of nylon screws and wing nuts, denoted 27 a in FIGS. 2B and 2C , that are inserted into said two (2) apertures.
Non-rotating disc 12 b is normally secured directly to its adjacent cardboard support components with a screw and wing nuts 27 b as best understood in connection with FIG. 2B .
Mounting member 26 a may be formed of polycarbonate, plastic, ABS, wood or metal.
Blocker disc 12 b has substantially the same construction as a rotating target disc 12 a and can be used as a target disc, just as a rotating target disc 12 a can be used as a blocker disc 12 b . Each blacker disc 12 b is a pre-notched, pre-cut, pre-slotted and pre-drilled section of corrugated or fluted card board (also known as fiberboard), cardstock, poster board and single or multiple ply paper of various thickness and density or circular or other predetermined geometric configuration. Corrugated or fluted card boards can also be stacked and layered to produce a more robust product for use with heavier caliber projectiles and arrows.
Blocker arm 28 , mentioned above, is an elongate flat member that is vertically oriented in this particular embodiment. It is positioned behind blocker disc 12 b but in front of target disc 12 a , motor 24 and motor housing 24 b . Its function is to protect said motor and motor housing from projectiles. Blocker arms 28 also serve to block the shooter's view of motor 24 and motor housing 24 b thus indirectly helping the shooter to concentrate on the rotating target decals.
FIGS. 3A and 3B are front elevation and top plan views, respectively, of an arrangement where novel system 10 is arranged so that two rotating discs 12 a , depicted in FIG. 3B but not in FIG. 3A , and their associated blocker discs 12 b , also depicted in FIG. 3B but not in FIG. 3A , are positioned in laterally spaced apart relation to one another with adequate spacing to prevent torn pieces of still-attached cardboard, naturally produced by exiting projectiles and emerging on the reverse side of 12 b , from contacting and interrupting the rotation of 12 a . This allows a shooter to try to hit targets by quickly aiming to the left and to the right in alternating sequence as target discs 12 a rotate. The rate of rotation as well as the direction of rotation may also be different for the two rotating discs 12 a , 12 a.
Mounting arm 30 is preferably provided in the form of a single piece of ABS plastic. It is inserted into and pushed through platform 15 so that platform 15 is mid-length of said mounting arm. Another function of platform 15 is also disclosed in FIGS. 3A and 3B . Platform 15 is hollow and enables the mounting of mounting arm 30 aforesaid so that said mounting arm 30 extends in a horizontal plane on opposite sides of vertical column 11 . Targets may be secured in multiple configurations to the outboard ends of mounting arm 30 . Mounting arm 30 is protected by flat blocker arms 28 , 28 which are parallel to mounting arm 30 and which are positioned between the shooter and mounting arm 30 . The mounting arm is square in transverse section.
Ninety degree (90°) elbow 22 is preferably formed of plastic square tubing. This elbow shape enables motor output shaft 24 a and therefore discs 12 a and 12 b to be positioned in multiple orientations.
Motor housing post 25 which is square in transverse cross section is releasably and slideably received within vertical column 11 which is also square in transverse section in the embodiment of FIGS. 2A-C as disclosed above. In many other embodiments, said post is received within elbow part 22 a or 22 b , and said elbow parts are in turn received within vertical column 11 or within mounting arm 30 . Vertical column 11 and mounting arm 30 are slideably received within the elbow parts.
There are two (2) elbow members 22 in the configuration depicted in FIGS. 3A and 3B . First part 22 a extends into the plane of the paper in FIG. 3A as best understood in the top plan view of FIG. 3B . Second part 22 b thereof is disposed in ensleeving engagement with its associated platform mounting arm 30 . Motor housing post 25 is releasably and slideably received within the hollow interior of elbow part 22 b.
Accordingly, elbow parts 22 a are superfluous in this particular arrangement because motor housing posts 25 , 25 can be inserted directly into the hollow interiors of elbow parts 22 b.
The square-in-transverse-section of vertical column 11 , each motor housing post 25 , mounting arm 30 , and each elbow part 22 a , 22 b , enables multiple interconnections of said part 30 and thus enables the output shaft 24 a of each motor 24 to be oriented in multiple configurations.
FIG. 3B in particular demonstrates that motor housing post 25 can be releasably and slideably received within the hollow interior of elbow part 22 a so that motor output shaft 24 a would extend out of the plane of the paper or into the plane of the paper in said FIG. 3B , and that each elbow part 22 a could be rotated from its FIG. 3B position relative to mounting arm 30 into three (3) additional positions.
More particularly, elbow part 22 a in FIG. 3B can be rotated ninety degrees (90°) from its depicted position so that it extends into the plane of the paper, another ninety degrees (90°) so that it is positioned in the plane of the paper but extending downwardly instead of its upward extension as depicted, and another ninety degrees (90°) so that it extends upwardly from the plane of the paper.
As depicted in FIG. 3B , each blocker disk 12 b is releasably mounted on its associated blocker arm 28 . Although a screw and wing nut is depicted, such mounting may also be accomplished by VELCRO® hook and loop fastening means or other releasable fastening means.
A pre-drilled hole near the free end of each blocker arm 28 enables the shooter to attach a blocker disc 12 b in a stationary position in front of an associated rotating target disk 12 a to temporarily block the shooter's view of rotating decal targets 14 as aforesaid.
Each elbow section 22 b may slideably receive mounting arm 30 at its inboard end as mentioned above and each elbow section 22 b may slideably receives motor housing post 25 at its outboard end. Where each mounting arm 30 is square or otherwise non-round in transverse section and where each elbow part 22 b is also square or otherwise non-round in transverse section to slidingly and non-rotatably mate therewith, elbow 22 may be attached to the platform mounting arm 30 in four (4) different positions, only one (1) of which is depicted in FIGS. 3A and 3B .
Where post 25 is also square or otherwise non-round in transverse section, motor housing 24 b and hence motor 24 and its output shaft 24 a can also be rotated relative to elbow part 22 b in the same way. Moreover, post 25 can be slideably removed from elbow part 22 b and slideably connected instead to elbow part 22 a and it may be further rotated in the same way relative to said elbow part 22 a , all of which will become clearer as this disclosure continues.
Elbow 22 thus enables rotating target disk 12 a and blocker disc 12 b to be positioned in multiple orientations, such as front view orientation as depicted in FIGS. 3A , 3 B, 4 A, 4 B, 5 A and 5 B, an end view vertical orientation as depicted in FIGS. 6A and 6B , or an end view of a horizontal orientation as depicted in FIGS. 7A and 7B .
FIGS. 8A-C , 9 A-C, 10 A-C and 11 A-C provide examples of possible configurations using one, two, three, and four targets, respectively. The multi-combination position of the DC motor configuration and rotating target disks serve to further challenge the skills of the shooter.
Elbow 22 and motor housing post 25 are quickly and easily removed by hand and positioned into a preselected orientation, thus enabling the shooter to tailor the configuration of system 10 into said front-vertical, edge-vertical and edge-horizontal orientations.
In the vertical orientations, rotating target disc 12 a rotates in a vertical plane about a horizontal axis and the shooter has either a frontal view of the target which requires no target tabs 16 or an edge view thereof which does require said target tabs. In the horizontal orientation, rotating target disc 12 a rotates in a horizontal plane about a vertical axis and therefore target tabs 16 are required.
The speed and the direction of revolution of rotating target disk 12 a is regulated by a controller positioned between the battery and motor 24 .
The size of each rotating target disc 12 a may be decreased or increased and the shape of each target decal 14 may be changed to any predetermined geometrical configuration. The size of each window 20 formed in blocker disc 12 b may be increased or decreased, and the geometrical configuration of each window may be changed. The direction of rotation of rotating target disk 12 a may be changed. Moreover, the distance between the shooter and said rotating target disc may be changed.
An arrangement of parts that essentially combines the arrangement of FIG. 1A and that of FIGS. 3A and 3B is depicted in FIGS. 4A and 4B . This arrangement provides the two laterally-spaced apart targets of FIGS. 3A and 3B and includes a second vertical column 11 a that is surmounted by a single target. This arrangement of parts further challenges the shooter relative to the challenge provided by the two-target embodiment of FIGS. 3A and 3B .
An arrangement of parts that adds a second set of laterally spaced apart targets is depicted in FIGS. 5A , 5 B, and 5 C. This arrangement includes a second vertical column 11 a like the embodiment of FIGS. 4A and 4B but replaces the single top target with a second pair of laterally spaced apart targets, thereby providing four (4) targets to still further challenge the shooter. The embodiment of FIGS. 5A-C is essentially the same as the embodiment of FIGS. 3A and 3B , there being a second set of laterally spaced apart targets in the embodiment of FIGS. 5A-C .
FIGS. 6A and 6B disclose an arrangement of two laterally spaced apart targets, both of which are on edge to the shooter and thus require target tabs 16 . Both targets in this arrangement rotate in a vertical plane about a horizontal axis. No blocker discs 12 b are needed when targets discs 12 a are presented on edge to the shooter as depicted.
Yet another configuration indicating the large number of differing configurations that may be provided by this novel system is depicted in FIGS. 7A and 7B . Two laterally spaced apart target discs 12 a are mounted about a vertical axis for rotation in a horizontal plane so tabs 16 are needed as depicted. Note that for each rotating target disc 12 a , only two (2) tabs 16 , 16 are normally mounted in perpendicular relation to the plane of said target discs.
FIGS. 8A-C , 9 A-C, 10 A-C and 11 A-C depict various configurations made with this invention as mentioned above. Note that blocker disc 12 b is not used whenever target disc 12 a is presented on edge to the shooter as mentioned above.
FIG. 12A depicts the base assembly in exploded form and FIG. 12B depicts it in assembled form. Rubber-type grommets, not depicted, are placed on vertical column 11 to maintain platform 15 in a pre-selected position.
FIG. 12C is a plan view that best shows why post 11 is offset with respect to base 13 . Part 13 a is a hollow tube glued or otherwise secured into the depicted position. Said part 13 a is a sleeve that receives vertical column 11 . The offset mounting of sleeve 13 a with respect to base 13 is not critical to the invention. Many other mechanically robust bases could be used to support the operative elements of the invention. All alternative bases are within the scope of this invention.
Novel system 10 can be mounted on the ground, a floor, a table, or other support surface. It may also be suspended from an upstanding support. A handle, not depicted, could be provided to envelope a small gauge wire for hanging purposes. Novel system 10 may be used at indoor and outdoor shooting ranges or home venues.
Two or more of the novel systems in any configuration may be interconnected to one another by a vertical connector member. The vertical connector, not depicted, would include a plurality of perforated and pre-scored lines. The vertical connector could also be used to hang a bracket which would allow the system to be suspended as mentioned above.
It will thus be seen that the objects set forth above, and those made apparent from the foregoing disclosure, are efficiently attained and since certain changes may be made in the above construction without departing from the scope of the invention, it is intended that all matters contained in the foregoing disclosure or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.
It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention that, as a matter of language, might be said to fall therebetween.
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A target practice apparatus adapted to receive projectiles fired at it by a remotely positioned shooter includes a motor having an output shaft, a motor housing, and a post secured to the motor and motor housing. A target disc is secured to the output shaft and rotates with it. A frame supports the motor housing and the target disc. An L-shaped elbow member is attachable to the frame in a plurality of differing configurations. The post is also attachable to the frame in a plurality of differing configurations and is further attachable to the L-shaped elbow member in a plurality of differing configurations. This enables the target disc to be positioned in a vertical plane facing the shooter or on edge to the shooter and a horizontal plane on edge to the shooter. A non-rotating blocker disc having window openings partially obscures the target disc in the shooter-facing configuration.
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CROSS-REFERENCE TO RELATED APPLICATION(S)
The present disclosure claims the benefit of U.S. Provisional Patent Application Ser. No. 60/787,901, filed Mar. 31, 2006, and claims priority from European Patent Application EP06006832.7, filed Mar. 31, 2006, the entire disclosures of which are incorporated herein by reference.
BACKGROUND
The invention relates to a locking assembly for securing a rod member in a receiver part connected to a shank for use in spinal or trauma surgery. The invention further relates to a bone anchoring device using such a locking assembly and to a tool for cooperating with such a locking assembly.
U.S. Pat. No. 6,224,598 B1 discloses a threaded plug closure adapted for use in securing a rod member to a bone screw implant, said closure comprising a plug having a threaded cylindrically-shaped outer surface, said plug being received between a pair of arms of a medical implant during use, a central coaxial bore passing entirely through said plug, said central bore having an internal threaded surface which is shaped to receive a set screw. The plug closure and the set screw can be independently installed and the set screw tightened to cooperatively provide capture and locking of the rod in order to secure the rod against translational and rotational movement relative to the bone screw.
US 2003/0100896 A1 discloses a bone anchoring device with a shank and a receiving part connected to it for connecting to a rod. The receiving part has a recess having a U-shaped cross-section for receiving the rod with two open legs and an internal thread on the open legs. A locking assembly is provided comprising a nut member with an external thread which cooperates with the internal thread of the legs and a set screw. The nut member has on one end slits for engagement with a screw tool. The shank has a spherically shaped head which is pivotably held in the receiving part and a pressure element is provided which exerts pressure on the head when the nut member is tightened. By tightening the set screw the rod is fixed in the receiving part. Hence, the rod and the head can be locked independently from each other. The internal thread and the cooperating external thread of the nut member are designed as a flat thread. The implant has a compact design, since an outer ring or nut to prevent splaying of the legs is not necessary.
The outer diameter of the locking assembly is under various aspects determined by the required tightening torque and the thread form. In turn, the overall dimensions of the upper portion of the bone anchoring device are determined by the size of the locking assembly.
Therefore, there is a need for a locking assembly and a bone anchoring device with a locking assembly which has the same reliability as the known devices but which has smaller dimensions of the upper portion. Furthermore, there is a need for a tool for such a locking assembly.
SUMMARY
The locking assembly according to the invention can be designed with a smaller outer diameter compared to the known locking assemblies. Therefore, the size of the bone anchoring device can be reduced. The bone anchoring device with such a reduced size is particularly suitable for application to the cervical spine or other areas where a limited available space requires compact implants.
Furthermore, the locking assembly is structured so as to allow nesting of two or more locking elements.
With the tool according to the invention a simultaneous but independent fixation of the locking elements of the locking assembly is possible.
Further features and advantages of the invention will become apparent and will be best understood by reference to the following detailed description of embodiments taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a cross-sectional view of an embodiment of the bone anchoring device with the locking assembly.
FIG. 2 shows a perspective elevational view of the bone anchoring device of FIG. 1 .
FIG. 3 shows a perspective view from the top of the locking assembly.
FIG. 4 shows a cross-sectional view of the locking assembly of FIG. 3 .
FIG. 5 shows a side view of the locking assembly of FIG. 3 .
FIG. 6 shows a perspective view of a tool.
FIG. 7 shows a cross-sectional view of the lower part of the tool cooperating with the locking assembly.
FIG. 8 shows a perspective view of the locking assembly and the lower part of the tool.
FIG. 9 shows a perspective view of the locking assembly with cooperating portions of the tool shown in section wherein the other parts of the tool are omitted.
FIG. 10 shows a perspective view of a modification of the first locking element of the locking assembly.
FIG. 11 shows a perspective view of a further modification of the first locking element of the locking assembly.
FIG. 12 shows a second embodiment of the locking assembly in a top view.
FIG. 13 shows a further embodiment of the locking assembly in a perspective view.
FIG. 14 shows the locking assembly of FIG. 13 in a top view.
FIG. 15 shows the locking assembly of FIG. 13 in a sectional view along line A-A of FIG. 14 .
FIG. 16 shows a tool cooperating with the locking assembly of FIG. 13 in a sectional view.
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1 and 2 show the locking assembly used in a polyaxial bone anchoring device 1 . The bone anchoring device comprises a bone screw 2 having a shank 3 with a bone thread and a spherically-shaped head 4 . The bone screw 2 is received in a receiving part 5 which has a first end 6 and a second end 7 and is of substantially cylindrical construction. The two ends are perpendicular to a longitudinal axis L. Coaxially with the longitudinal axis L a bore 8 is provided which extends from the first end 6 to a predetermined distance from the second end 7 . At the second end 7 an opening 9 is provided, the diameter of which is smaller than the diameter of the bore 8 . The coaxial bore 8 tapers towards the opening 9 . In the embodiment shown it tapers in form of a spherically shaped section 10 . However, the section 10 can have any other shape such as, for example, a conical shape.
The receiving part 5 , further, has a U-shaped recess 11 which starts at the first end 6 and extends in the direction of the second end 7 to a predetermined distance from said second end. By means of the U-shaped recess two free legs 12 , 13 are formed ending towards the first end 6 . Adjacent to the first end 6 , the receiving part 5 comprises an internal thread 14 at the inner surface of the legs 12 , 13 . In the embodiment shown, the internal thread 14 is a flat thread having horizontal upper and lower thread flanks.
Additionally, a pressure element 15 is provided which has a substantially cylindrical construction with an outer diameter sized so as to allow the pressure element 15 to be introduced into the bore 8 of the receiving part and to be moved in the axial direction. On its lower side facing towards the second end 7 , the pressure element 15 comprises a spherical recess 16 cooperating with a spherical section of the head 4 . On its opposite side the pressure element 15 has a U-shaped recess 17 extending transversely to the longitudinal axis L by means of which two free legs 18 , 19 are formed. The lateral diameter of this U-shaped recess is selected such that a rod 20 which is to be received in the receiving part 5 can be inserted into the recess 17 and guided laterally therein. The depth of this U-shaped recess 17 is larger than the diameter of the rod 20 so that the legs 18 , 19 extend above the surface of the rod 20 when the rod is inserted.
The bone anchoring device comprises a locking assembly 30 . The locking assembly 30 includes, as shown in particular in FIGS. 2 to 5 a first locking element 31 and a second locking element 32 . The first locking element has a first end 33 and a second end 34 and a substantially cylindrical shape between the first and the second end and with an outer surface having an external thread 35 which is, in the embodiment shown, a flat thread which matches with the internal thread 14 of the receiving part 5 . Further, the first locking element comprises a coaxial bore 36 extending from the second end 34 in the direction of the first end 33 . The coaxial bore 36 comprises an internal thread, which is in the embodiment shown a metric thread. The first locking element 31 further comprises a coaxial recess 37 starting from the first end 33 and extending to a predetermined distance from the second end 34 . The mean diameter of the recess 37 is larger than the diameter of the coaxial bore 36 . As can be seen in particular in FIG. 3 , by means of the recess 37 a substantially ring-shaped wall is formed. A plurality of longitudinal grooves 38 are formed extending from the first end 33 along the wall to the bottom 39 of the recess 37 . The grooves 38 shown in this embodiment have an approximately semi-circular cross section. They are equidistantly distributed in a circumferential direction of the recess 37 . Preferably, at least two grooves are formed. The wall of the recess 37 can have a slanted surface 40 adjacent to the first end 33 in order to facilitate the introduction of a tool. The depth of the recess 37 is selected such that the length of the bore 36 is still sufficient to cooperate with the second locking element 32 for a good fixation. On the other hand the depth of the recess 37 is such that an area sufficient for engagement with a tool is provided.
The second locking element 32 is shaped as a set screw with an external thread 42 cooperating with the internal thread of the coaxial bore 36 . The axial length of the second locking element 32 is such that when the second locking element 32 is completely screwed into the first locking element 31 it projects slightly from the second end 34 of the first locking element. As can be seen in particular in FIG. 4 , the second locking element 32 comprises a coaxial recess 43 with grooves 44 extending in longitudinal direction, similar to the recess 37 and the grooves 38 of the first locking element. The recess 43 and the grooves 44 serve for a form-fit cooperation with a tool to be described hereinafter.
A tool for cooperating with the locking assembly is shown in FIGS. 6 to 9 . The tool 50 comprises a tube 51 and a bar 52 which is slidable in the tube 51 . The tube 51 has an end section 53 for cooperation with the locking assembly and a second end with a grip portion 58 which has, for example, a hexagonal outer shape. As can be seen in particular in FIGS. 7 to 9 , the end section 53 has a reduced outer diameter, corresponding to the inner diameter of the recess 37 of the first locking element. The end section 53 comprises a plurality of projections 54 the number of which is less than or equal to the number of the grooves 38 of the first locking element. The projections 54 are structured and designed to engage with the grooves 38 of the first locking element to provide a form-fit connection between the end section 53 of the tool and the recess 37 of the first locking element. The axial length of the end section 53 is preferably equal to or larger than the depth of the recess 37 .
The bar 52 comprises an end section 55 which is structured and designed to cooperate with the recess 43 of the second locking element 32 . For this purpose, the end section 55 has a plurality of projections 56 the number of which is equal to or less than the number of grooves 44 of the second locking element and which are structured and designed to engage with the grooves 44 . On its opposite end, the bar 52 has a grip portion 57 which allows to grip the bar 52 and to rotate it independently from the tube 51 . The length of the bar 52 is selected such that when the end section 53 of the tube is engaged with the first locking element, the second locking element 32 can be independently engaged by the end section 55 of the bar and screwed into the first locking element.
In operation, first, at least two usually preassembled bone anchoring devices comprising the bone screw 2 , the receiving part 5 and the pressure element 15 are screwed into the bone. Thereafter, the rod 20 is inserted into the U-shaped recess 11 of the receiving part 5 . Then, the locking assembly 30 , comprising the first locking element 31 and the second locking element 32 which are preferably preassembled, is screwed-in between the legs 12 , 13 of the receiving part 5 . The first locking element is tightened by applying the tool 50 such that the end section 53 of the tube engages with the recess 37 and the grooves 38 of the first locking element to form a form-fit connection. In this way, pressure is exerted by the lower side of the first locking element onto the free legs 18 , 19 of the pressure element which presses onto the head 4 of the bone screw 2 to lock the head in its rotational position relative to the receiving part 5 .
Then, the second locking element 32 is tightened by application of the tool in that the end section 56 of the bar engages the recess 43 of the second locking element and torque is applied. In this way, the position of the rod 20 relative to the receiving part is fixed.
A fine tuning of the position of the receiving part 5 relative to the bone screw 2 and of the rod 20 relative to the receiving part can be performed by loosening either the first locking element 31 or the second locking element 32 .
FIG. 9 shows a perspective view of the locking assembly 30 with the end sections 53 and 56 of tool engaging the locking elements with the tool shown in section. For the purpose of illustration only, the remainder of the tool is not shown. As can be seen in FIG. 9 , the end sections of the tool and the recesses of the first and second locking elements form a form-fit connection for the application of torque to screw-in the locking elements. The external thread 35 of the first locking element is of continuous form, without recesses or interruptions. Therefore, the dimension of the locking element can be reduced. This guarantees safe locking of the first locking element. The area required for engagement of the tool with the first locking element is located within the recess 37 . This allows to design the first locking element 31 with a reduced diameter. If the number of grooves 38 is increased, the depth of the grooves can be reduced. Hence, the size of the first locking element can be reduced corresponding to the increase of the number of grooves.
The size of the outer dimension of the first locking element 31 determines the size of the receiving part and the other elements of the bone anchoring device. Further, since the external thread of the first locking element remains intact over its whole length, the height of the locking element can be reduced.
FIG. 10 shows the first locking element 31 with a modified shape of the grooves. The grooves 38 ′ have a triangular cross section. FIG. 11 shows the first locking element 31 with a further modification of the shape of the grooves. The grooves 38 ″ have a square cross section. However, the cross section of the grooves may have another shape as well.
FIG. 12 shows a second embodiment of the locking assembly. The locking assembly 300 comprises three locking elements. The first locking element 301 is shaped like the locking element 31 of the first embodiment. The second locking element 302 differs from the second locking element 30 of the first embodiment in that is has coaxial threaded bore, like the first locking element, to receive the third locking element 303 . It is also possible to design the locking assembly with more than three nested locking elements such that each of the locking elements has a threaded coaxial bore to receive a further locking element. In this manner, for certain applications, an improved fixation can be achieved, for example, if used in complex minimally invasive surgery procedures.
The locking assembly according to a further embodiment includes one single locking element 400 which has an external thread 401 and a coaxial bore 402 extending through the entire locking element from the first end 403 to the second end 404 . A coaxial ring-shaped recess 405 extends from the first end 403 in the direction of the second end. The wall of the recess comprises a plurality of longitudinal grooves 406 for engagement with a tool. By means of the recess 405 and the coaxial bore 402 , a coaxial hollow cylindrical section 407 is formed in the locking element.
A tool for engagement with the locking element is adapted to be engageable with the ring-shaped recess 405 . FIG. 16 shows an exemplary tool 500 cooperating with the locking element 400 . The end section 501 comprises a ring-shaped projection 502 adapted to engage the recess 405 in a form-fitting manner. The end section also 501 comprises a central projection 503 with a retaining spring 504 engaging the coaxial bore 402 for facilitating alignment and handling of the locking element.
The locking element can be used in such applications where it is necessary to introduce an instrument or a wire through the bore 402 , for example in the case of minimally invasive surgery.
Further modifications are possible. The external and the internal thread can have any thread shape, such as, for example, a metric thread. Using a flat thread, a saw-tooth thread or a negative angle thread for the external thread of the first locking element and the cooperating internal thread of the receiving part, however, has the advantage that it prevents splaying of the legs of the receiving part. Therefore, an outer ring or a nut to prevent splaying is not needed. By using the locking assembly of the invention together with a flat thread as the external thread, the implant can be further downsized.
The number of the grooves and the shape of the grooves can vary.
It is conceivable to design the first locking element with a recess having a quadrangular or hexagonal or otherwise polygonal cross section with or without grooves. In this case, the end section of the tool has a matching shape. This also provides for a form-fit connection between the tool and the first locking element with the external thread of the first locking element remaining intact.
The second locking element 32 or the third locking element 303 in the case of the locking assembly 300 of the second embodiment or, in general, the inmost locking element in the case of a locking assembly having multiple locking elements may not need to have a recess with grooves as shown in the embodiment. It is sufficient, that the inmost locking element has a recess for engagement with screwing-in tool, such as a hexagon recess. The corresponding end section of the tool is then adapted to this shape.
The disclosure is not limited to the polyaxial bone anchoring device as shown in the first embodiment. It can be used in the case of a monoaxial bone anchoring device in which the receiving part is fixedly connected to the shank of the bone screw as well. Furthermore, the polyaxial bone anchoring device can have a different construction. It is possible to have a design of the receiving part which allows that the screw is inserted from the bottom instead from the top of the receiving part.
The locking assembly can also be used in such kind of bone anchoring devices in which the receiving part is designed and structured so that the rod is fixed laterally apart from the central axis of the bone screw.
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A locking assembly for securing a rod in a receiving part of a bone anchoring device includes a first locking element having a first end and a second end and a longitudinal axis of rotation and an outer surface provided with an external thread, a coaxial bore passing entirely through said first locking element and an internal thread provided at said bore, a second locking element having a: longitudinal axis of rotation and an outer surface with an external thread cooperating with the internal thread of said first locking element. The first locking element has a recess between the first end and the second end, that defines a circumferentially closed wall portion. The interior of the wall portion has a longitudinally extending structure for engagement with a tool. Furthermore, a tool is provided which has sections which can be independently engaged with the first and second locking element, respectively.
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REFERENCE TO RELATED APPLICATIONS
[0001] The present invention claims the benefit of German Patent Application No. 102 53 643.0, filed Nov. 18, 2002.
TECHNICAL FIELD
[0002] The present invention relates to a window lifter control system for a motor vehicle and a method of controlling at least two window lifter motors.
BACKGROUND OF THE INVENTION
[0003] When an electric window lifter motor of a window lifter fully closes a window pane, the window lifter motor is rotationally driven to close the window pane until the window pane presses against an associated seal on the window frame with a desirably high amount of force, causing the window pane to come to a stop. The window lifter motor is blocked when the window pane is stopped by the seal, causing a high blocking current (e.g., 30 A) to flow through the window lifter motor. This is acceptable as long as the blocking current flows through only one window lifter motor in the vehicle.
[0004] However, currently available comfort functions in vehicles are able to close all of the window panes of the vehicle simultaneously. In fact, some consumers find it disturbing when, in spite of identical starting positions, different window panes in the vehicle reach the fully closed position at different times even though the associated window lifters received the instruction to close the window panes at the same time. But if all of the window panes are actually closed at the same time, this can result in as many as four window lifter motors being supplied with the blocking current at the same time. The high amount of blocking current to the window lifter motors leads to a noticeable voltage drop in the power supply of the vehicle. This voltage drop is especially critical if the vehicle is provided with other electric systems which have high power requirements themselves, such as an electrical steering system (“steer-by-wire”) or an electrical brake system (“brake-by-wire”). As soon as a control unit in such systems detects the voltage drop, the system may be momentarily disconnected until the voltage drop is over. Obviously, however, it is undesirable in an electrical steering system or an electrical brake system for a functional interruption to occur.
[0005] There is a desire for a window lifter system in which, on the one hand, can meet the demands in relation to comfort (e.g., simultaneous window closing) made by the ultimate customers and, on the other hand, avoids voltage drops in the on-board supply when meeting those demands.
SUMMARY OF THE INVENTION
[0006] One embodiment of the invention is directed to a method of controlling at least two window lifter motors. When at least one of the window lifter motors is instructed to close the window pane associated with the motor to it, the method determines whether the window pane is approaching its fully closed position. The method then checks whether any other window pane is approaching its own fully closed position. If any other window pane is approaching its fully closed position, the original window pane is moved only as far as to an approximately closed position rather than its fully closed position. If, on the other hand, no other window pane is approaching its fully closed position, the window pane is moved to its fully closed position.
[0007] The invention generally prevents a plurality of window lifters from fully closing their respectively assigned window panes at the same time. Instead, only the window lifter that is the first one to close the window pane is allowed to close the window pane fully, causing the window lifter motor to block and blocking current to flow. All other window lifter motors in the vehicle are turned off so that the window pane does not reach its fully closed position and only reaches an approximately closed position in which it contacts its associated seal with a low force. The contact gives a vehicle user the impression that the window pane is already fully closed and that all window panes were closed simultaneously.
[0008] Once the first window pane is fully closed, all the remaining window panes will then also be fully closed, occurring in a staggered relationship with respect to one another so that only one single window lifter motor is blocked at any given time when the window pane presses against its corresponding seal. The short time interval between the time the first window pane closes fully and the time the other window panes closes fully will go unnoticed by the user. The minimum adjustment of the window pane from the approximately closed position to the fully closed position will not be detectable by the user of the vehicle, and as a result the invention will not impair user comfort.
[0009] The moment at which each window pane enters a previously defined end zone portion of its travel distance may be used as a criterion for the decision of which window pane should be allowed to be fully closed. This end zone may cover, for instance, the last 4 mm of the distance traveled before reaching the fully closed position. As soon as a window pane enters this end zone, a blocking signal is transmitted by a controller of the respective window lifter and transferred via a bus system to all other window lifter controllers in the vehicle. If any other controller receives the blocking signal when the window pane assigned to it arrives at the end zone, the other controller will not close the window pane fully, but move it only into the approximately closed position.
[0010] As soon as a window lifter has shifted the window pane into its approximately closed position, it is checked in a loop to see whether the previously received blocking signal continues to be applied. As soon as the blocking signal is no longer applied, a counter starts, initiating a waiting time corresponding to each window controller. After the waiting time has elapsed, the window lifter motor for a given window is driven to move the window pane into its fully closed position while a blocking signal is sent at the same time. This prevents any of the other window lifters from simultaneously shifting their respectively assigned window panes from the approximately closed position to the fully closed position. The blocking signals and waiting times stagger the times at which each window is moved to the fully closed position so that only one window is moved to the fully closed position at a time.
[0011] In one embodiment of the invention, the method suppresses detection of multiple window pane closings when the engine of the vehicle is not running because, in this case, there are no expected negative effects if the multiple window closings create a voltage drop in the on-board voltage supply.
[0012] Another embodiment of the invention is directed to a window lifter control system comprising at least two window lifter motors, at least one controller for driving the window lifter motors, and a sensor that detects the position of a window pane assigned to the window lifter motor. The controller includes a checking circuit that checks whether any other window lifter is a transmitting a blocking signal. The system further includes a blocking signal generator, which generates a blocking signal when the window lifter motor causes its corresponding window pane to approach its fully closed position, and a counter that can detect an expiration of a predetermined waiting time. The description below explains the advantages that may be gained using a window lifter control system of this type in more detail.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The invention will now be described with reference to a preferred embodiment which is illustrated in the accompanying drawings, in which:
[0014] [0014]FIG. 1 is a representative diagram of a window lifter system including two window lifters according to one embodiment of the invention; and
[0015] [0015]FIG. 2 is a representative flow diagram of a method that may be sequenced in one of the window lifters of FIG. 1.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0016] [0016]FIG. 1 is a representative diagram of a window lifter system according to one embodiment of the invention and FIG. 2 is a flow diagram of a method according to one embodiment of the invention. Note that although FIG. 1 shows only two window lifters 5 , 7 for illustrative purposes, the system may include more than two window lifters without departing from the scope of the invention.
[0017] In the embodiment shown in FIG. 1, each window lifter 5 , 7 has a window lifter motor 10 which acts on a window pane 14 of a vehicle via an adjustment mechanism 12 . The window pane 14 is adapted to be shifted within a window frame 16 , which is provided at least at its upper edge with a seal 18 , shown schematically in FIG. 1. The window pane 14 can be moved in the window frame 16 by the window lifter motor 10 .
[0018] A controller 20 is provided for driving the window lifter motor 10 . The controller 20 is usually disposed inside the vehicle door in which the window pane 14 is guided and is therefore frequently referred to as a door control module. Each controller 20 drives the window lifter motor 10 by, for example, pulse width modulation. A sensor 22 is provided on the window lifter motor 10 through which a position recognition circuit 24 inside the controller 20 may sense the absolute position of the window pane 14 . In one embodiment, the sensor 22 may be a Hall effect sensor.
[0019] The controller 20 further includes a counter 26 that generates a waiting time. In one embodiment, the counters associated which each controller 20 differ from one another so that each controller 20 in the vehicle each has its own unique waiting time.
[0020] Each controller 20 further contains a blocking signal checking and generating circuit 28 , each of which is able to generate a blocking signal and to sense whether any other controller generates such blocking signal.
[0021] The controllers 20 are connected to a bus system 30 , such as a CAN bus.
[0022] The operation of the window lifter system will now be described when it is intended to close the window panes 14 , reference being also made to the flow chart of FIG. 2.
[0023] When a vehicle user wishes to close a particular window pane 14 such as, for example, the window pane associated with the right-hand window lifter 7 in FIG. 1, the user actuates the appropriate window lifter switch so that the controller 20 drives the window lifter motor 10 in the proper direction for the window pane 14 to be closed. During the closing process of the window pane 14 , the absolute position of the window pane 14 sent to the controller 20 at all times since the sensor 22 continuously supplies information about the position of the window lifter motor 10 .
[0024] When the window pane 14 arrives at an end zone E, which is defined as, for example, the last 4 mm of the closing travel before reaching the fully closed position, the blocking signal checking and generating circuit 28 checks, by way of the bus system 30 , whether any other controller 20 is transmitting a blocking signal 32 . The blocking signal may be, for example, one bit that is encoded in a specific way corresponding to a given controller 20 with the bus system 30 , with each bit encoded in a unique manner to correspond with its associated controller 20 . In the example shown in FIG. 1, the blocking signal checking and generating circuit 28 of the controller 20 of the left-hand window lifter 5 does not send a blocking signal. Therefore, the blocking signal checking and generating circuit 28 of the controller 20 associated with the right-hand window lifter 7 will now generate a blocking signal, which is transmitted to all other controllers 20 in the vehicle via the bus 30 .
[0025] At the same time, since the blocking signal checking and generating circuit 28 of the right-hand window lifter 7 is not currently receiving a foreign blocking signal, the right-hand window lifter motor 10 continues to be supplied with power until the window pane 14 comes up against the seal 18 at full power and comes to a stop. As a result of this, the right-hand window lifter motor 10 is also braked to a standstill and the window lifter motor 10 consumes its blocking current. The high torque produced by the window lifter motor 10 in this condition ensures that the right-hand window pane 14 is pressed against the seal 18 with a desirably high force to ensure that the window pane 14 is fully closed tightly.
[0026] The window pane of the left-hand window lifter 5 is also closed at approximately the same time as the window pane 14 of the right-hand window lifter 7 . However, since the window pane of the left-hand window lifter 5 slightly lags behind the window pane of the right-hand window lifter 7 , the window pane 14 of the left-hand window lifter 5 will enter the end zone slightly later than that of the right-hand window lifter 7 . At the moment the controller 20 detects that the left-hand window pane 14 has arrived at the end zone E, the blocking signal checking and generating circuit 28 detects that a foreign controller 20 is generating a blocking signal, namely the controller 20 of the right-hand window lifter 7 . The left-hand window lifter motor 10 is therefore stopped before the window pane 14 rides up on the seal 18 and is braked by the window pane 14 ; in other words, the left-hand window lifter motor 10 is stopped so that the window pane 14 is in an approximately closed position in which it contacts the seal 18 with a low force.
[0027] The controller 20 subsequently checks whether any foreign blocking signal is continuing to be received. As soon as the controller 20 no longer detects a foreign blocking signal, the counter 26 is activated, which generates a specific time delay or waiting time. After expiration of this time delay, the blocking signal checking and generating circuit 28 transmits its own corresponding blocking signal while the left-hand window lifter motor 10 is at the same time supplied with power so that the left-hand window pane travels from the approximately closed position to the fully closed position until it is braked by the seal 18 and until the left-hand window lifter motor 10 is blocked.
[0028] While only two window lifters are shown in FIG. 1, it is readily apparent that the window panes can be closed in a time-staggered as described above and as shown in FIG. 2 when more than two window lifters are provided. In the case of systems having more than two window panes and more than two associated window lifters, only the window pane that is the first to enter the end zone E is closed fully without interruption, whereas all other window panes will be stopped at the approximately closed position and closed one after the other in a staggered fashion into the fully closed position based on the different waiting times as generated by the counter 26 of each respective controller 20 .
[0029] It should be understood that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention. It is intended that the following claims define the scope of the invention and that the method and apparatus within the scope of these claims and their equivalents be covered thereby.
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A window lifter system and method coordinates closing of multiple windows by detecting when more than one window pane is approaching a fully closed position and moving one window pane to only an approximately closed position while the other window pane is moved to the fully closed position. By staggering the closure of window panes to the fully closed positions, the system and method provides the illusion that all of the window panes are being closed at the same time while avoiding voltage drops in the vehicle power supply caused by excessively high blocking currents generated when multiple window panes are moved to the fully closed position.
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FIELD OF THE INVENTION
[0001] This invention relates to oxetane compounds containing styrenic functionality.
BACKGROUND OF THE INVENTION
[0002] Oxetanes are highly reactive cyclic ethers that can undergo both cationic and anionic ring opening homopolymerization. Styrenic compounds are capable of free radical polymerization.
SUMMARY OF THE INVENTION
[0003] This invention relates to compounds that contain an oxetane functionality and a styrenic functionality. These compounds can be homopolymerizable in reactions in which the oxetane can undergo cationic or anionic ring opening, or polymerizable with compounds such as electron acceptor compounds. The dual functionality allows for dual cure processing, both thermal cure or radiation cure. This capability makes them attractive for use in many applications, such as, adhesives, coatings, encapsulants, and composites.
DETAILED DESCRIPTION OF THE INVENTION
[0004] In one embodiment, the compounds of this invention can be represented by the formula
in which R 1 is a methyl or ethyl group; R 2 and R 3 are H or a methyl or ethyl group; R 4 is a direct bond or a divalent hydrocarbon; X and Y are independently a direct bond, provided both are not a direct bond, or an ether, ester, amide, or carbamate group; Q is a divalent hydrocarbon (which may contain heteroatoms of N, O, or S); and G is —OR 1 , —SR 1 , or —N(R 2 )(R 3 ), in which R 1 , R 2 and R 3 are as described above; provided that X will not be
when R 4 , Q and Y are absent, and R 2 and R 3 are H; and provided that X will not be
when R 4 is
Q and Y are absent, and R 2 and R 3 are H. The configuration of the Q portion will depend on the configuration of the starting styrenic compound.
[0005] The starting styrenic compound may be small molecule, for example, 3-isopropenyl-α,α-dimethyl-benzyl isocyanate (m-TMI), 4-vinyl-benzyl chloride, the reaction product of m-TMI with a diol, the reaction product of m-TMI with the hydroxyl functionality on a carboxylic acid containing a hydroxyl group, and isoeugenol. The starting styrenic compound may also be an oligomeric or polymeric compound, prepared by reacting, for example, m-TMI or 4-vinyl-benzyl chloride with one functionality on a difunctional oligomer or polymer.
[0006] Whether the starting styrenic compound is a small molecule or an oligomeric or polymeric material, it will contain a styrenic functionality represented by the structural formula
in which R 2 and R 3 are H or a methyl or ethyl group and G is —OR 1 , —SR 1 , or —N(R 2 )(R 3 ), in which R 1 is a methyl or ethyl group and R 2 and R 3 independently are H or a methyl or ethyl group. The starting styrenic compound also will contain a second functionality reactive with the starting oxetane compound. For example, the styrenic starting materials disclosed above contain halogen, hydroxyl, or isocyanato functionality in addition to the styrenic functionality.
[0007] The starting oxetane compound may be a small molecule or an oligomeric or polymeric molecule, prepared, for example, by reacting one of the small molecule oxetane starting compounds disclosed below with one functionality on a difunctional oligomer or polymer. In either case, it will contain an oxetane functionality represented by the structure
and a second functionality reactive with the second functionality on the styrenic starting compound.
[0008] Suitable starting oxetane compounds that are small molecules include, for example,
(a) alcohols, such as, 3-methyl-3-hydroxymethyloxetane, 3-ethyl-3-hydroxymethyloxetane;
(b) halides, such as, 3-methyl-3-bromomethyloxetane, 3-ethyl-3-bromomethyloxetane, which can be prepared by the reaction of an alcohol from (a) with CBr 4 as is known in the art;
(c) alkyl halides, such as, 3-methyl-3-alkylbromomethyloxetane, 3-ethyl-3-alkylbromomethyloxetane, which can be prepared from the reaction of an alkyl dibromide compound with an oxetane alcohol from (a) as is known in the art;
and (d) tosylates, such as, 3-methyl-3-tosylmethyloxetane, 3-ethyl-3-tosylmethyl-oxetane, which can be prepared from p-toluenesulfonyl chloride:
[0013] When a longer chain and higher molecular weight compound containing styrenic and oxetane is desired, either the starting styrenic compound or the starting oxetane compound, or both, may be extended by reaction with a difunctional oligomeric or polymeric material. The second functionality on this oligomeric or polymeric material must be reactive with the oxetane starting compound if the first reaction was between the styrenic starting compound and the difunctional oligomeric or polymeric material, and with the styrenic starting compound if the first reaction was between the oxetane starting compound and the difunctional oligomeric or polymeric material. Examples of suitable and commercially available oligomers and polymers include dimer diol and poly(butadiene) with terminal hydroxyl functionality.
[0014] In the case in which both the oxetane and styrenic compounds are extended by reaction with a difunctional oligomer or polymer, Q may also contain a functionality, for example, an ether, ester, carbamate, or urea functionality, resulting from the reaction of the two oligomeric or polymeric starting materials.
[0015] In general, the inventive compounds containing oxetane and styrenic functionality are prepared by reacting together a starting compound containing oxetane functionality and a second functionality and a starting compound containing styrenic functionality and a second functionality reactive with the second functionality on the oxetane compound. Typical reaction schemes include well known addition, substitution, and condensation reactions.
[0016] In a further embodiment, the compounds of this invention include polymeric compounds that contain more than one oxetane and more than one styrenic functionality. Such compounds are prepared from a polymeric starting compound from which depend functionalities that are reactive with the starting oxetane compound and the starting styrenic compound.
[0017] The polymeric compound will have the structure
in which polymer is a polymeric backbone from which depend the oxetane and styrenic functionalities; m and n are integers that will vary with the level of oxetane and styrenic functionality added by the practitioner and typically will be from 2 to 500; R 1 is a methyl or ethyl group; R 2 and R 3 are H or a methyl or ethyl group; R 4 is a direct bond or a divalent hydrocarbon; W and Z independently are an ether, ester, amide, or carbamate group (formed through the reaction of a pendant functionality on the polymer and a corresponding reactive functionality on the starting oxetane or starting styrenic compound, respectively); and G is —OR 1 , —SR 1 , or —N(R 2 )(R 3 ), in which R 1 , R 2 and R 3 are as described above.
[0018] The pendant functionalities on the polymer may be connected to the polymeric backbone by a hydrocarbon, for example, one having one to twenty carbons, that itself is dependent from the polymeric backbone. For purposes of this specification, those dependent moieties will be deemed to be part of the polymeric backbone.
[0019] An example of a commercially available and suitable polymeric backbone is poly(butadiene) having pendant hydroxyl groups. The pendant hydroxyl groups can be reacted with the oxetane starting compound containing the tosyl leaving group and with m-TMI. In this case, the linking group W will be an ether functionality and Z will contain a carbamate functionality.
[0020] As a further example, a poly(butadiene) having pendant carboxylic acid functionality can react with the hydroxyl functionality on either of the hydroxyl oxetane starting materials and with the isocyanate functionality on m-TMI. In this case, the W group will be an ester functionality and Z will contain a carbamate functionality.
[0021] Polymeric starting material can be purchased commercially, for example, there are available acrylonitrile-butadiene rubbers from Zeon Chemicals and styrene-acrylic copolymers from Johnson Polymer. The pendant functionalities from these polymers are hydroxyl or carboxylic acid functionality.
[0022] Other starting polymeric materials can be synthesized from acrylic and/or vinyl monomers using standard polymerization techniques known to those skilled in the art. Suitable acrylic monomers include α,β-unsaturated mono and dicarboxylic acids having three to five carbon atoms and acrylate ester monomers (alkyl esters of acrylic and methacrylic acid in which the alkyl groups contain one to fourteen carbon atoms). Examples are methyl acryate, methyl methacrylate, n-octyl acrylate, n-nonyl methacrylate, and their corresponding branched isomers, such as, 2-ethylhexyl acrylate. Suitable vinyl monomers include vinyl esters, vinyl ethers, vinyl halides, vinylidene halides, and nitriles of ethylenically unsaturated hydrocarbons. Examples are vinyl acetate, acrylamide, 1-octyl acrylamide, acrylic acid, vinyl ethyl ether, vinyl chloride, vinylidene chloride, acrylonitrile, maleic anhydride, and styrene.
[0023] Other polymeric starting materials can be prepared from conjugated diene and/or vinyl monomers using standard polymerization techniques known to those skilled in the art. Suitable conjugated diene monomers include butadiene-1,3,2-chlorobutadiene-1,3, isoprene, piperylene and conjugated hexadienes. Suitable vinyl monomers include styrene, α-methylstyrene, divinylbenzene, vinyl chloride, vinyl acetate, vinylidene chloride, methyl methacrylate, ethyl acrylate, vinylpyridine, acrylonitrile, methacrylonitrile, methacrylic acid, itaconic acid and acrylic acid.
[0024] Those skilled in the art have sufficient expertise to choose the appropriate combination of those monomers and subsequent reactions to be able to add pendant functionality, for example, hydroxyl and carboxyl functionality, for adding the oxetane and styrenic functionalities as disclosed in this specification.
EXAMPLES
Example 1
Preparation of Styrene Carbamate Ethyl Oxetane
[0025]
3-Ethyl-3-hydroxymethyl-oxetane (40.00 g, 0.3442 mole) and m-TMI (69.43 g, 0.3442 mole) were combined in a 250-ml four-neck round bottom flask equipped with a condenser, mechanical mixer, nitrogen purge and oil bath. The reaction was placed under nitrogen with stirring and heated to 65° C. in the oil bath. A single drop of dibutyltin dilaurate was added, thereby causing an exothermic reaction which peaked at 125° C. The oil bath was removed and the reaction temperature dropped to 65° C. within 15 minutes. At this point, the reaction was complete based on the depletion of the FT-IR isocyanate peak at 2254 cm −1 . The product was then removed from the flask as a viscous colorless liquid; however, over time it crystallized into a white solid with a m.p. of 52° C.
[0026] H 1 -NMR: δ 7.21-7.61 (m, 4H), 5.45 (s, 1H), 5.23 (bs, 1H), 5.12 (s, 1H), 4.61-4.21 (bm, 3H), 4.05 (s, 3H), 2.15 (s, 3H), 1.55-1.85 (bm, 8H), 0.55 -1.01 (bm, 3H).
Example 2
Preparation of Styrene Carbamate Methyl Oxetane
[0027]
3-Methyl-3-oxetane methanol (20.00 g, 0.1958 mole) and m-TMI (39.49 g, 0.1958 mole) were combined in a 250-ml four-neck round bottom flask equipped with a condenser, mechanical mixer, thermometer, nitrogen purge and oil bath. The reaction was placed under nitrogen with stirring and heated to 65° C. in the oil bath. A single drop of dibutyltin dilaurate was added and within 5 hours the reaction was complete based on depletion of the FT-IR isocyanate peak (2254 cm −1 ). The product was then removed from the flask as a colorless liquid with a viscosity of 21,000 cPs.
[0028] H 1 -NMR: δ 7.61 (s. 1H), 7.42 (s, 3H), 5.45 (s, 1H), 5.31 (bs, 1H), 5.15 (s, 1H), 4.61 (bm, 1H), 4.39 (bm, 1H), 4.12 (s, 4H), 2.21 (s, 3H), 1.72 (bs, 6H), 0.95-1.35 (bm, 3H).
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These compounds contain an oxetane functionality and a styrenic functionality. The oxetane functionality is homopolymerizable in reactions that undergo cationic or anionic ring opening, and the styrenic is polymerizable with compounds such as electron acceptor compounds. The dual functionality allows for dual cure processing. The compounds will have the structure
in which R 1 is a methyl or ethyl group; R 2 and R 3 are H or a methyl or ethyl group; R 4 is a direct bond or a divalent hydrocarbon; X and Y are independently a direct bond or an ether, ester, amide, or carbamate group, provided both X and Y are not a direct bond; Q is a divalent hydrocarbon (which may contain heteroatoms of N, O, or S); and G is —OR 1 , —SR 1 , or —N(R 2 )(R 3 ), in which R 1 , R 2 and R 3 are as described above.
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REFERENCE TO RELATED APPLICATION
This application is a formal application based on provisional application filed on Aug. 25, 2000, Ser. No., 60/228,318.
TECHNICAL FIELD OF THE INVENTION
This invention concerns a specialty bag construction and method of manufacturing the same. In particular, the bag wall has a number of venting bands for the proper venting of certain stored perishable items.
BACKGROUND OF THE INVENTION
Bulk bags are commonly used to store and transport many agricultural products. Many such products, especially those easily perishable ones, require the bag to be properly vented to prevent the build up of excessive moisture with ensuing growth of mold and deterioration of the content. Furthermore, these bags are usually non-reusable due to sanitation concern. Thus, these ventable bags need to be produced in high volume, having a specifiable degree of venting yet with very low cost. One common way to achieve this is to weave in a set of venting bands of specified width and density with a flat loom. However, the associated post operation involves, after cutting the panel to size, folding and sewing of two lines to form the bag. Additionally, the flat loom machine is quite an expensive investment. Thus, the overall production cost of the bag can be undesirably high.
SUMMARY OF THE INVENTION
The present invention consists of a method which inexpensively and efficiently manufactures such ventable bags in high volume with a specifiable range of design of venting bands. Thus, the bag itself is also encompassed by the present invention.
The bag is a traditional one having a cylindrical body panel with one end of the panel sown closed to form the storage cavity. The other end of the cylindrical body panel is left open for communication with the interior of the bag. However, the cylindrical body panel of the bag comprises a specified number and location of venting bands along the direction of the cylindrical axis. Furthermore, the width of the said venting bands is also specifiable by design.
The method of manufacturing the bag starts with the tubular weaving of yams of proper materials with a circular loom whereby an elongated tubular structure is formed with woven warp and weft strands. The direction of the warp strands is parallel to the tubular axis whereas the direction of the weft strands is perpendicular to the tubular axis.
However, around the periphery of a concentration ring of said circular loom a number of mechanical expansion blocks are disposed at the proper location replacing the otherwise warp strands to be fed thus woven into said cylindrical body panel of the bag. For convenience, these locations are to be called band locations. As there is an absence of warp strands at each such band location, the resulting woven wall structure of the said band consists of only weft strands. Without the interlocking power from the missing warp strands, the flexing weft strands within said band create substantially larger air gaps in between than otherwise possible with the presence of interlocking warp strands. These air gaps within said bands thus form the desired venting structure for the bag. Therefore, emerging from said circular loom with the adaptation of the invention embodiment is a woven tubular structure wherein a number of venting bands parallel to the tubular axis are built in wherever said invention embodiment is disposed along the circumferential periphery of the tube. It is also important to remark that, as part of the function of the circular loom, said emerging woven tubular structure is actually flattened into a continuous belt form and wound into a roll for easiness of subsequent handling.
The tubular structure is sectioned off along a set of lines with predetermined spacing to form a set of tubular segments, each tubular segment having the desired set of venting bands extending axially from a first open end to a second open end. For convenience, the first open end of the said tubular structure is to be called the top opening and the second open end of the said tubular structure is to be called the bottom opening.
The bottom opening of the said tubular structure is now sewn closed along the direction perpendicular to the tubular axis. The top opening of the said tubular structure is left open forming the desired bag opening.
Thus, a storage bag having a cylindrical body panel is described wherein a desired set of venting bands extending axially is built in on the body panel. Additionally, an inexpensive and efficient method is described herein for the manufacturing of such ventable bags in high volume. Furthermore, said method of manufacturing embodies the adaptation of a set of simple mechanical elements onto an existing circular loom.
Other features, objects and advantages of the present invention will become apparent with reference to the following drawings and associated descriptions.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a perspective view of a portion of the weaving mechanism inside a circular loom wherein one mechanical expansion block of the present invention is disposed to replace an otherwise corresponding group of warp yarns feeding the weaving mechanism;
FIG. 2 illustrates a section of a woven tubular structure coming out of an unmodified circular loom wherein the woven warp and weft strands are partially shown to illustrate their orientation;
FIG. 3 illustrates a section of a woven tubular structure coming out of a circular loom modified with the present invention wherein a set of six venting bands made with the present invention is also illustrated;
FIG. 4 is a perspective illustration of a small section of the detailed woven structure including the corresponding section of a venting band made with the present invention;
FIG. 5 illustrates a prior art finished bag made from a section of a woven tubular structure coming out of an unmodified circular loom, after the bottom opening of the sectioned tubular structure is sewn closed; and
FIG. 6 illustrates a finished bag made from a section of a woven tubular structure coming out of a circular loom modified with the present invention, after the bottom opening of the sectioned tubular structure is sewn closed.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 5 illustrates a typical prior art bulk bag made with a circular loom. The cylindrical body panel 10 comprises many tightly interlocking strands of woven warp 2 A and woven weft 3 A woven by a well-known circular loom machine. The material for the warp and weft strands can be any of the many materials compatible with the circular loom. Some examples are polyethylene, polypropylene and nylon. It is important to remark that, as part of the function of the circular loom, the said emerging woven cylindrical body panel 10 is actually flattened into a continuous belt form and wound into a roll for easiness of subsequent handling. The bottom opening of the cylindrical body panel 10 is sewn closed to form a sewn bottom edge 12 . The top opening 11 comes naturally out of the sectioning operation of the tubular body structure into bag segments.
Although many such bulk bags are commonly used to store and transport a wide variety of products and materials, many such products, especially those easily perishable ones, require the bag to be adequately vented to the ambient to prevent the build up of excessive moisture with ensuing growth of mold and deterioration of the content. Some examples are potatoes and vegetables. For such products, the tightly interlocking strands of woven warp 2 A and woven weft 3 A of the prior art bulk bag does not allow adequate degree of venting to the ambient and means of controllably increasing the degree of venting must be devised to solve the problem.
FIG. 6 illustrates a bulk bag from the present invention whereby the desired degree of increase of venting is accomplished. As stated above, the cylindrical body panel 10 comprises many tightly interlocking strands of woven warp 2 A and woven weft 3 A. The bottom opening of the cylindrical body panel 10 is sewn closed to form a sewn bottom edge 12 . The top opening 11 comes out of the sectioning operation of the tubular body structure into bag segments. However, around the periphery of the cylindrical body panel 10 a set of venting bands 9 is disposed. Within each venting band 9 , instead of having both warp and weft strands, only woven weft in venting band 3 B exists. Without the interlocking power from the missing woven warp 2 A, the flexing woven wefts in venting band 3 B within the said venting band 9 now create substantially larger air gaps in between than otherwise possible with the presence of interlocking woven warp 2 A. These air gaps within said venting band 9 thus form the desired venting structure for the bag of the present invention. The method by which these venting bands 9 on the cylindrical body panel 10 are manufactured is described below.
The method of manufacturing the bag starts with the tubular weaving of yarns of warp and weft materials with a well-known circular loom whereby an elongated tubular structure is formed with woven warp and weft strands. FIG. 1 is a perspective view of a portion of the weaving mechanism inside a circular loom wherein a full circle of radially converging warp strands 2 are interlockingly woven with another set of circumferentially directed weft strands 3 . For easiness of viewing, neither the full set of warp and weft strands nor the circular-weaving heads are shown. After passing through the underside of a concentration ring 1 , the just woven cylindrical web turns vertical in direction, forming a cylindrical body panel 10 and continues to be pulled upwards toward an ultimate take up roller which is not shown here. The direction of the woven warp 2 A is parallel to the tubular axis whereas the direction of the woven weft 3 A is perpendicular to the tubular axis.
Around the periphery of the concentration ring 1 of said circular loom a number of expansion blocks 7 are disposed at the proper location replacing the otherwise converging warp strands 2 to be fed thus woven into said cylindrical body panel 10 of the bag. For convenience, these locations are to be called band locations. For simplicity, only one expansion block 7 is shown. The expansion block 7 , through a cylindrical link 6 , is attached to a flexible belt 4 whose outer end is fixed at a convenient tie point 5 on the frame of the circular loom.
The absence of woven warp 2 A at each such band location results in the presence of only woven weft 3 B in said venting band 9 . Without the adaptation of the present invention, as illustrated in FIG. 2, a totally symmetric cylindrical structure would be formed wherein the whole cylindrical wall comprises tightly interwoven warp 2 A and woven weft 3 A. Whereas with the present invention, as shown in FIG. 3, a woven tubular structure wherein a number of venting bands 9 parallel to the tubular axis are produced wherever the invention embodiment is disposed along the circumferential periphery of the tube.
Additionally, with reference to FIG. 1, the width of the expansion block 7 is intentionally oversized with respect to the replaced width of the missing warp strands 2 . Thus, during the weaving operation, a controlled amount of lateral squeezing force is produced which causes a closer packing of the woven warp 2 A along the edge of the venting band 9 . This is illustrated in FIG. 4 which shows a perspective view of a small section of the detailed woven structure including the corresponding section of a venting band 9 made with the present invention. Along the two edges of the venting band 9 are formed two squeeze zones 8 wherein both the woven warps in left squeeze zone 2 A 1 and the woven warps in right squeeze zone 2 A 2 are packed with a pitch tighter than elsewhere on the woven web.
It should be understood that, with the present invention, the amount of venting for the bulk bag can be flexibly controlled with the proper combination of the selection of number, location and size of the expansion block 7 . The invention is applicable, in particularly, to the storage and transportation of potatoes where a proper degree of venting is needed to prevent the growth of mold thus causing deterioration of the potato while avoiding excessive sun exposure which also causes another type of deterioration.
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A specialty bag is formed from a circular loom adapted with a unique mechanism of the current invention such that the resulting woven tubular sheet contains at least one venting band extending along the length of the tubular sheet. The tubular sheet is then cut into individual bag segments. The individual bag segments are sewn together along their bottom edge to form the final bag having at least one venting band for the proper venting of the enclosed items.
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BACKGROUND OF THE INVENTION
The present invention relates to a failsafe monitoring system for detecting actual or impending failure of a rupture disc and providing an alarm when such a failure occurs.
The most frequent utilization of a rupture disc is in pipelines which are normally unused vent passageways in a chemical process system but which are intended to provide safety relief should some process vessel or conduit over or under pressurize, thereby creating a hazardous condition. The rupture disc, by its nature, is usually hidden from view and, therefore, it is often difficult to visually determine when failure thereof has occurred. Even when it is obvious to an observer that failure of a rupture disc has occurred, such as when a gas or liquid fluid is suddenly venting or flowing into an open area where none should be, it is still important that the failure be noticed as quickly as possible, since the fluid may be hazardous and/or explosive, and since some type of safety equipment or procedure may be immediately required to protect personnel and/or equipment. For example, it may be necessary to shut off a pump to stop the discharge.
Conventional rupture disc alarm systems typically require that a portion of a broken disc engage a sensing probe or similar device before an alarm is sounded. A disc failure, however, can be sufficiently explosive or unpredictable in operation to leave no parts in position for engaging the probe or the probe itself can be rendered inoperative due to damage or electrical failure. Also, the probe systems typically do not detect potential failure of a disc, such as the stretching thereof to a predetermined percentage of the failure point. Further, conventional systems normally detect failure of a disc in only one direction, thus requiring multiple systems. Still further, probe systems are usually difficult to install and require special mounting parts and procedures. In addition, conventional alarm systems are often not failsafe, whereby they do not sound an alarm in case of part failure or loss of power.
It is noted that pressure switches have been utilized to sense failure of a rupture disc; however, such switches can only be used in closed systems wherein pressure will build downstream of a broken rupture disc and thus activate the switch, especially if the escaping fluid has a low pressure differential across the disc and slow flow rates. It is therefore desirous to have a failure sensing device which will function in open as well as closed systems and particularly in low pressures.
It is also noted that rupture discs are often used in areas wherein there is a potential for explosion. Therefore parts of a rupture disc in the explosive area should be intrinsically safe electrically and otherwise explosion proof.
OBJECTS OF THE INVENTION
Therefore, the objects of the present invention are: to provide a monitoring system for detecting failure in a rupture disc and notifying operating personnel or modifying operating equipment in response to such a failure; to provide such a system for also detecting impending or partial failures of rupture discs; to provide such a system which can detect failure in two directions; to provide such a system which is failsafe in design; to provide such a system comprising a signal carrying circuitor loop which is interrupted or otherwise modified by failure or impending failure of the rupture disc and a signal sensor which detects such a modification of the signal passing through the loop and activates an alarm; to provide such a system wherein failure of any portion thereof interrupts the signal and activates the alarm and is, therefore, essentially failsafe; to provide such a system wherein the loop may include an intrinsically safe electrical signal passing therethrough; to provide such a system which will function in both closed and open systems, at low pressures; to provide such a system which is relatively easy to install in conjunction with a rupture disc; to provide such a system having a signal carrying loop which is easily and simply replaced along with an associated rupture disc after failure of the latter; to provide such a system which is economical to produce, positive in operation, easy to use, and particularly well adapted for the proposed usage thereof.
Other objects and advantages of this invention will become apparent from the following description taken in connection with the accompanying drawings wherein are set forth by way of illustration and example, certain embodiments of this invention.
SUMMARY OF THE INVENTION
A monitoring system is provide for detecting total, partial and/or impending failure of a rupture disc which blocks passage of fluids through a conduit and activates an alarm when such a failure occurs. The system comprises a signal carrying circuit or loop, a signal sensor and an alarm mechanism. The signal carrying loop is part of, adjacent to or in close association with the rupture disc to be monitored, such that a modification of the disc also creates a signal modifying change in the signal carrying loop. In one embodiment of the invention the signal is an electrical current; the signal carrying loop is an electrical circuit which varies in resistance if broken or otherwise modified; and the signal sensor is a device to sense change in the electrical signal caused by variance of the resistance in the circuit. In another embodiment of the invention, the signal is an optical wave or light generated by a suitable source, the signal carrying loop is a light transmitting optical fiber, and the sensor includes means such as a photocell which is responsive to changes in light intensity or level. The signal sensor may be adjusted to detect actual failure and/or stretching of the rupture disc to a predetermined percentage of failure. The alarm mechanism may notify operating personnel, activate safety equipment, and/or modify process equipment when failure or impending failure of a rupture disc is detected.
The drawings constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partially schematic side elevational view of a rupture disc relief assembly incorporating a disc failure monitoring system according to the present invention.
FIG. 2 is an enlarged vertical cross-sectional view of the relief assembly as shown in FIG. 1.
FIG. 3 is a transverse cross-sectional view of the relief assembly taken along line 3--3 of FIG. 2 with portions broken away to show detail thereof.
FIG. 4 is an exploded perspective view of a portion of the relief assembly.
FIG. 5 is a fragmentary cross-sectional view of the relief assembly taken along line 5--5 of FIG. 3.
FIG. 6 is a perspective view of a rupture disc and signal carrying loop for the rupture disc assembly.
FIG. 7 is a fragmentary cross-sectional view of the rupture disc and signal carrying loop as shown.
FIG. 8 is a perspective view of a modified rupture disc and signal carrying loop.
FIG. 9 is a cross-sectional view of a second modified rupture disc incorporating a signal carrying loop.
FIG. 10 is a perspective view of a third modified disc incorporating a signal carrying loop.
FIG. 11 is a top plan view of the third modified disc.
FIG. 12 is a fragmentary and enlarged cross-sectional view of the third modified disc taken along line 12--12 of FIG. 11.
Material thickness in the drawings may in some places be exaggerated for illustrative purposes.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure.
For purposes of description herein in the terms "upper," "lower," "vertical," "horizontal," and derivatives thereof along with other directional references shall relate to the invention as oriented in FIGS. 1 through 3; however, it is to be understood that the invention may assume various alternative orientations, except where expressively specified to the contrary.
The reference numeral 1, as shown in FIG. 1, generally designates a rupture disc assembly including a rupture disc failure monitoring system 2, according to the present invention, positioned between two spaced portions 3 of a conduit such as the illustrated vent pipe 4 or the like. In normal operation the assembly 1 is secured to the vent pipe portions 3 by suitable means such as bolted flanges, welding, treaded engagement, clamps or the like, such that the assembly 1 is secured in place and fluid is prevented from seepage between the interconnection thereof with the vent pipe portions 3. As used herein the term "fluid" means both gases and liquids.
The assembly 1, normally blocks flow of fluids in either direction along the vent pipe 4. The vent pipe 4 generally communicates with processing equipment such as positive and negative pressure vessels (not shown) and provides relief for excessive pressure conditions therein. In order to relieve from one vent portion 3 to the other, the blockage provided by the assembly 1 is ruptured or otherwise removed.
The assembly 1, as is partially shown in FIG. 4, comprises an outlet crown 10, a perforated top section 11, a deformable member, disc, or rupturable seal 12 having a portion of the monitoring system 2 attached thereto, a lower vacuum girdle 14, and an inlet crown 15 having a knife blade assembly 16 mounted therein. Pins 20 pass through apertures 21 in and secure against horizontal rotary movement of the top section 11, the seal 12 and the girdle 14 relative to the crowns 10 and 15. A quick disconnect sanitary type band 22 extends around and secures together proximate circumferential flanges or edges 23 and 24 of the crowns 10 and 15 respectively, see FIG. 1, with an outer annular flange portion 25 of the seal 12 secured therebetween. It is foreseen that the assembly 1 could vary greatly within the conventional art of rupture disc protection devices requiring only a rupturable type seal which is deformed and/or broken by excessive positive and/or negative pressure and which functions in cooperation with the monitoring system 2.
In the particular assembly 1 illustrated in FIG. 4, the top section 11 is a forward type rupturing disc having a perforated and radially grooved, cut or slit concave-convex portion 26 and a relatively flat annular flange portion 27. The section 11 is similar to that type shown in U.S. Pat. No. 3,881,629.
The seal 12 illustrated in FIG. 4 is constructed of a material suitably impermeable to whatever fluid will be blocked thereby. A suitable material may be a flexible plastic such as tetrafluoroethylene and co-polymers, such as are marketed under the trademark "Teflon". The seal material and thickness thereof is selected so as to be frangible or stretchable to such a degree that rupture occurs when a preselected positive or negative pressure differential is reached on opposite sides thereof. In some rupture disc assemblies, a seal will not be externally supported. However, in FIG. 4 both the section 11 and the girdle 14 support the seal 12 against certain positive and negative pressure differentials respectively. The seal 12 should also be able to withstand slight but rather continuous flexing which occurs due to frequently changing pressure differentials without fatigue failure. Although the seal may take many various shapes or forms including flat, the illustrated seal 12 has a concave-convex interior portion 30 to which the flange 25 is secured. Frequently, a convex side of the seal 12 substantially mates with a concave side of the section 11; however, in some prewarning installations, it is desired to determine when a pressure differential between opposite sides of the seal 12 has reached a certain percentage of that differential which will cause rupture of the seal 12. In such prewarning installations, the seal 12 may be spaced from or have a somewhat different curvature as compared to the section 11. It is foreseen that the seal 12 could be a wide variety of non-metallic or metallic materials such as aluminum. The girdle 14 may be any suitable support structure preventing the seal from buckling or reversing until a preselected negative pressure differential is reached. The illustrated girdle 14 has an outer annular flange 31 and three stays 32. The stays project upwardly and inwardly so as to mate with the convex side of the seal 12. The top section flange 27, the seal flange 25, and the girdle flange 31 are preferably coextensive with each other and with the proximate crown flanges 23 and 24 such that a seal is formed therebetween to prevent seepage of fluid from the interior to the exterior of the assembly 1. Suitable gaskets or gasketing sealant may be utilized where necessary to produce such a fluid seal.
The cutting member or knife blade 16 has three radiating arms 33 extending upwardly near an axis thereof and joining with the inlet crown 15. The upper end of each arm 33 is sharpened so as to form a cutting edge 34. The knife blade 16 is aligned with the girdle 14 such that the girdle stays 32 do not engage the cutting edge 34 if the stays 32 are deformed toward the inlet crown 15. The cutting edge 34 is aligned so as to engage, impale, and rupture the seal 12 should the latter be deformed in such a manner to invert or buckle, that is, wherein the normal concave side of the seal 12 would become a convex side and vice versa.
In the illustrated embodiment the crowns 10 and 15, the section 11, the girdle 14, the band 22 and parts associated therewith function as support means 36 for the seal until the latter is ruptured. It is seen that the seal support means 36 could be very complex or very simple depending on the type of assembly utilized. It is also seen that the seal could function as part of the support means 36 for example by combining the girdle 14 and seal 12 illustrated into a single unit.
The monitoring system 2 comprises generating means 40, signal carrying means 41, sensor means 42 and alarm means 43.
The generating means 40 may be any suitable device for producing a signal and is shown in FIG. 1 by the box denoted "signal generator". Preferably the generating means 40 produces a "pulsating" or continuous signal, although it is forseen that any definable varying signal could be utilized provided that proper cooperation with the sensor means 42 is provided such that an undefined variance in the signal could be detected as will be described below. The generating means 40 may produce an electrical, optical, fluid flow, or other suitable signal depending on the particular system utilized. The illustrated generating means 40 produces an electrical current having a predetermined reference energy level. Supply of such an electrical current may be accomplished by utilizing a conventional public power supply from an A.C. electrical line, producing an electrical current with a generator or battery, or transforming one of the previously mentioned supplies into a suitable signal. As many installations require an intrinsically safe, that is a sufficiently low voltage and amperage electrical system to avoid possible fires or explosions, it is preferable that the electrical current and voltage be sufficiently low to avoid such dangerous energy levels capable of igniting explosive atmospheres. Transformation of standard A.C. electrical supply to produce an electrical current within the nature of 6 volts D.C. and less than 0.1 M amperes has been found to generate a suitably failsafe signal when coupled with proper resistence throughout the system 2. It is noted that where no electricity can be tolerated within the system, the optical signal may be utilized. The generating means for an optical system 100, such as is shown in FIGS. 10 through 12, comprises a light or optical wave producing mechanism 101 such as a bulb, light emitting diode or laser and an associated optical fiber 102 to transmit the light.
The said carrying means 41, as illustrated in FIGS. 1 through 5, comprises a circuit, conduit, or loop 50 which transmits a signal from the generating means 40 to the sensor means 42. The loop 50 passes in close proximity to the seal 12 and is preferably secured thereto or equivalently to another deformable member of the assembly 1. The loop 50 has the capacity to be altered when an associated seal 12 is deformed, such as when the seal 12 is ruptured, although in some installations the loop 50 is altered or modified when the seal 12 is simply flexed or stretched without rupturing. Preferably alteration of the loop 50 produces a proportional modification in the level of energy of the signal transmitted thereby as compared to the reference level of energy produced by the generating means 40.
In the illustrated embodiment the loop 50 includes a shielded cable or conduit comprising a first wire 56 from the signal device or generating means 40 which joins with one end 52 of a U-shaped wire 53, as best seen in FIG. 3, at a quick type terminal or connector 54. An opposite end 55 of the U-shaped wire 53 joins at the connector with a second wire 51 which is electrically connected to the sensor means 42. In this manner an electrical circuit from the generating means 40 to the sensor means 41 is completed, provided the U-shaped wire 53 remains intact.
Preferably the U-shaped wire 53 has a resistance which varies in inverse proportion to the cross-section thereof. Hence, as the seal 12 deforms, the wire 53 is stretched causing the latter to also deform and, in particular, to change in cross-section. Such a change in cross-section increases the resistance of the wire which in turn modifies or alters the signal being transmitted by the loop 50. Of course, if the seal 12 ruptures, the loop 50 is broken, thereby modifying the transmitted signal and, in particular, completely interrupting the signal. The loop 50 may be broken by overstretching under tensile forces or by being cut by the cutting edge 34.
The loop 50, as shown, comprises a thin conductor or U-shaped wire 53 of an electrically conducting metal or other suitable conducting material, such as gold, copper, graphite, or the like. A metal wire or foil may be deposited directly on a non-conducting seal 12 by metal plating, sputtering, vacuum deposition, silk screening, or the like. Preferably, the conductor 53 is insulated from the remainder of the assembly 1 by a suitable insulator 59, such as a polyester base film or the like. In the Figures, the insulator 59 is clear so that integrity of the loop 50 can be visually checked. Also, preferably, the loop 50 and insulator 59 therefor are attached to the seal 12 by direct application or suitable adhesive (not shown), such as a silicone adhesive or the like or the loop may be a conductive adhesive. The loop 50 may be reinforced by tape, conduit or the like between the emergence thereof from the support means 36 and the connector 54.
It is noted that the illustrated loop 50 is fully insulated within the vicinity of the assembly 1 while electricity is passing through or being transmitted by the loop 50. In addition, the loop 50 does not require special pipe or other parts requiring machinery to pass from the interior to the exterior of the support means 36. Also, the system is designed for inherent intrinsic safety.
As is illustrated, the loop 50 may be positioned on the convex side of the plastic seal 12. As seen in FIGS. 6 & 7, a loop 50a may be positioned on the convex side of a metallic seal 12a. The actual material of construction of a particular seal may vary substantially within the present invention. Alternatively, as seen in FIG. 8, a loop 50b may be positioned on the concave side of a seal 12b. Further alternatively a loop 50C may be positioned within and thus be made part of a seal 12c as shown in FIG. 9. It is foreseen that many possible placements of a suitable loop 50 are possible which are not illustrated herein; in particular, placement on the section 11 or girdle 14. Also, multiple use of different loops is possible, such as where it is desirious to continuously measure maximum deformation which the disc has experienced in either possible direction.
The sensor means or signal sensor 42 cooperates with the generating means 40 and, in particular, with the signal carrying means 41 and thereby detects the signal transmitted by the latter. The sensor 42 is adapted to detect variations, alterations or modifications in the energy level of the transmitted signal. In particular, the sensor means 42 has the capacity to respond to a modification of a predetermined amount of a transmitted signal and provide notice to or trigger an alarm or response at a location remote from the seal 12 when the signal has been modified. The major modification to the signal detected by the sensor 42 occurs when the seal 12 is ruptured, thus breaking the loop 50 and modifying the signal by stopping same completely. However, it is not necessary that the loop 50 break for the sensor 12 to provide the notice; in particular, the sensor 42 could be set, programmed or the like to provide notice when a seal expands, stretches or otherwise deforms to indicate that a certain percentage of the differential pressure which would cause rupture of the seal 12 has occurred or that fatigue has occured in the seal 12 and it should be replaced. Multiple loops 50 each on a respective seal 12 with associated sensors 42 set to give notice at different differential pressures or a sensor 42 programmed to give notice at multiple differential pressures can be utilized to continuously monitor a seal 12 before failure thereof without replacement of the seal 12 or loop 50.
The sensor 42 for an electrical signal may be any suitable device for receiving an electrical signal, detecting a change in the signal, and providing a response to the change. Normally the sensor 42 would be displaced from the seal 12. For optical signals associated with the optical system 100 of FIGS. 10 through 12, the sensor means comprises an optical sensor 103 for sensing the energy of an optical signal, detecting a predetermined change in the energy level, and providing notice of or response to such a change. Such an optical sensor 103 could include a photocell or a phototransistor cooperating with appropriate circuitry.
The alarm means or alarm mechanism 43, as illustrated by the box labelled "alarm mechanism" in FIG. 1, cooperates with the sensor 42 such that an alarm is triggered or activated by the notice or response which is provided by the sensor 42, that is, the notice or response that the seal 12 has deformed an amount for which it has been predetermined that something or someone should be notified.
The alarm means 43 may be any suitable device such as a horn, buzzer, flashing light or the like. In addition the alarm means 43 may simply constitute a transmission of a secondary signal such as the notice provided by the sensor means 42. Such a secondary signal can be utilized to activate safety equipment, initiate a change in operating equipment such as stopping a pump, or the like.
Preferably the alarm means 43 is activated by failure of the various components of the system 2 and, in particular, by failure of the generating means 40, the carrying means 41 or the sensor means 42. This may be accomplished by having the same power supply which operates the various components of the system 2 cooperate with the alarm means 43, such that when power is on the alarm means 43 is activated only by the sensor means 42 but when power fails to the entire system 2 or to one of the components thereof, then the alarm means 43 is also activated thereby making the system 2 failsafe, in that failure of any of the components of the system 2 activates a warning alarm thus preventing an undetected failure of the seal 12 when the system 2 is not functional.
The above described system 2 may be utilized: with standard rupture discs, reverse buckling discs, or graphite discs; as a component part in composite discs or double acting discs; as a leak detector, provided the leak modifies the seal; as a pressure detector in a pipeline; to detect fatigue or overpressure of a disc thereby predicting failure before same occurs; or the like.
In operation, the system 2 is installed, as shown in the figures for example, in conjunction with a seal 12 and support means 36 therefor in a vent pipe 4 or the like, thereby forming a complete assembly 1 for blocking flow of fluid through the pipe 4 until an excessive differential pressure occurs on opposite sides of the seal 12 at which time the disc or seal 12 fails or ruptures allowing flow of the fluid through the pipe 4. The system 2 detects rupture of the seal 12; in particular, a signal is produced by the generating means 40 and transmitted by the carrying means 41 to the sensing means 42 before failure. The carrying means 41 is broken when the seal 12 breaks, thus stopping transmission of the signal. The sensor means 42 detects that the signal has stopped and activates the alarm means 43.
For detection of an impending failure of a seal 12, the above process is the same except that the seal 12 deforms but does not deform sufficiently to break. The loop 50 deforms with the seal 12 and thus alters or modifies the signal. The sensor means 42 detects that the signal has been modified and when the modification of the signal drops to a predetermined level or amount, the sensor means 42 activates the alarm means 43.
Therefore, the method or process for detecting failure of the seal 12 of the assembly 1 comprises: generating a detectable signal, passing the signal through carrying means 41 closely associated with the seal 12 which carrying means 41 is modifiable by changes in condition of the seal 12, monitoring the signal after passing the seal 12, determining when a significant change has occurred in the signal after passing the seal 12, and relaying an alarm to a location remote from the seal 12 when such a significant change in the signal has occured.
It is to be understood that while certain embodiments of the present invention have been described and shown herein, it is not to be limited to specific forms or arrangement of parts herein described and shown, except insofar as such limitations are included in the following claims.
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A monitor system for sensing the failure of a rupture disc and activating an alarm in response to such a failure. The system also senses potential failure of a rupture disc. The system includes a failsafe signal carrying loop which is broken when the rupture disc fails, thereby interrupting the signal. The system also includes a signal sensor which recognizes a signal interruption or substantial modification in the signal and initiates and cooperates with an alarm device to provide notice to an operator or a safety device that the rupture disc has failed.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not Applicable
STATEMENT OF FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable
BACKGROUND OF THE INVENTION
[0003] 1. Technical Field
[0004] This invention relates in general to food packaging equipment and, more particularly, to equipment for sorting buns into lanes.
[0005] 2. Description of the Related Art
[0006] Commercial bakeries use high-speed packaging equipment to bag hamburger rolls, hot dog rolls, and other bread products (collectively, “buns”). Typically, the buns are packaged in arrays of one or more layers; for example, a sixteen bun package may package the buns in a four-by-four array and a 32 bun package may package the buns in two four-by-four layers.
[0007] In order to arrange the rolls in an array, a bun laner is used. The bun laner takes randomly arranged buns on a conveyer and aligns the buns into rows or “lanes”. When a sufficient number of buns are in each lane, a group is transported to a packaging machine.
[0008] Unfortunately, the randomly arranged buns do not evenly fill the lanes under normal circumstances. If a certain lane is not being filled as quickly as the other lanes, then the packaging machine must wait, slowing the packing process. Accordingly, the bun laner generally requires human intervention to direct the buns to the lanes evenly. Manual supervision of the machines, of course, increases the cost of packaging the buns and wastes human resources on a tedious chore.
[0009] Therefore, a need has arisen for a bun laner that does not require human supervision.
BRIEF SUMMARY OF THE INVENTION
[0010] In the present invention, a bun laner comprises a staging area for holding a plurality of buns and a predetermined number of lanes into which buns from the staging area are sorted. A bun detection unit detects each lane that has at least a predetermined number of buns and, responsive to a detection, a vacuum selectively closing one or more of the lanes.
[0011] The present invention provides significant advantages over the prior art. First, full lanes can be blocked using an uncomplicated vacuum mechanism. Second, the lanes are blocked without causing damage to the buns.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0012] For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:
[0013] FIG. 1 illustrates a general block diagram of a bun laner;
[0014] FIG. 2 illustrates a detailed top view of a bun laner;
[0015] FIG. 3 illustrates a front view of a vacuum unit in conjunction with a front cross-sectional view of the bun laner;
[0016] FIG. 4 illustrates a top view of a lane impeder unit.
DETAILED DESCRIPTION OF THE INVENTION
[0017] The present invention is best understood in relation to FIGS. 1-4 of the drawings, like numerals being used for like elements of the various drawings.
[0018] FIG. 1 illustrates a basic diagram of a bun laner 10 . Buns enter the laner 10 in staging area 12 after cooling an de-panning. Sorting mechanism 14 aids in directing buns 16 from the staging area 12 into one of the lanes 18 . Bun detection unit 20 detects when the number of buns in a lane have reached a predetermined point in the lane. Lane impeder 22 can impede bun movement into one or more selected lanes, responsive to a signal from bun detection unit 20 . A packaging device 24 receives buns from the lanes 18 a - d and packages the buns 16 .
[0019] In operation, the staging area 16 includes a conveyor belt which transports the buns towards the sorting mechanism 14 . The sorting mechanism could use, for example, moving guides as shown in FIGS. 2-4 . The purpose of the sorting mechanism is to direct randomly placed buns 16 into a lane 18 . Bun detection unit 20 could be implemented using an optical detector which senses the presence of a bun for a predetermined time (such as two seconds) or other optical, electrical, mechanical or electromechanical device which senses the presence of a bun for a predetermined amount of time or otherwise senses the non-movement of a bun. The purpose of the bun detection unit 20 is to signal the lane impeder whenever buns in a lane 18 have reached a certain point in the lane. Under control of the bun detection unit 20 , the lane impeder 22 temporarily stops buns from entering the filled lane(s). By impeding buns in one or more lanes, the remaining buns in the staging area 12 will be forced to enter an unfilled lane 18 . The lane impeder 22 selectively provides a vacuum at the bottom of the filled lanes, as shown in greater detail in connection with FIG. 3 .
[0020] For purposes of illustration, the lane impeder 22 is shown close to the bun detector 20 ; however, in an actual implementation, there would be several feet between these two units. Accordingly, by the time a filled lane is detected, there are likely to be additional buns behind the bun directly beneath the bun detector.
[0021] To illustrate the benefits of the bun laner 10 of FIG. 1 , it is assumed that the packaging device 24 is bagging buns in an array of 4×4, although any size array (or multiple arrays, such as a stack of two 4×4 arrays) could be accommodated by the bun laner 10 . In the case of a 4×4 array, the packaging device 24 cannot receive buns 16 from the laner 10 until each of the four lanes 18 a - d hold at least four buns. If, for example, the middle lanes 18 b - c are filling faster than the outside lanes 18 a and 18 d , the packaging device 24 will be delayed in its operation. In the present invention, once a predetermined number of buns are in a lane 18 (for example, twelve buns), that lane will be impeded by lane impeder 22 , which prevents further buns from entering the impeded lane(s). Hence, in this example, as soon as lane detector 20 detects twelve buns in lane 18 b , a vacuum is applied to that lane and further buns are stopped at the sorting mechanism 14 . The buns 16 in the staging area 12 will thus be directed to the other lanes. When there are enough buns 16 in lanes 18 for packaging, the buns 16 will be released to the packaging device 24 ; the release of the buns may or may not cause the impeded lanes to be re-opened, depending upon the number of buns behind the bun detection unit 20 at the time that the lane was closed.
[0022] Accordingly, with the lane impeder 22 controlled responsive to detection by the bun detection unit 20 , buns 16 are directed to under-filled lanes without human intervention.
[0023] FIG. 2 illustrates a more detailed top view of the bun laner 10 (in conjunction with the packaging device 24 . In staging area 12 , a first conveyor belt 30 transports buns 16 to the sorting mechanism 14 . Barriers 32 funnel the buns from to the center of the conveyor belt 30 , towards the lanes 18 a - d . The sorting mechanism 14 , shown in greater detail in connection with FIG. 4 , has five guides 34 which oscillate back and forth (in parallel) to align the buns 16 with the lanes 18 . Wheel 36 controls the movement of the guides 34 at it is rotated by a motor (not shown). Lane impeder 22 includes a perforated grate that is sloped slightly downward such that buns 16 slide over lane impeder 22 onto conveyor belt 37 when a vacuum is not being applied.
[0024] Once a bun has passed ever lane impeder 22 , it is transported down its lane by conveyor belt 37 . As the buns 16 are transported down a lane, they pass under bun detection unit 20 . If the bun detection unit 20 senses that a bun directly below the detection unit 20 is stationary, the bun detection unit 20 sends a signal to the lane impeder 22 indicating that the lane is full. At this point, buns may have already passed by the lane impeder 22 , so it is not necessarily the case that a bun underneath the bun detection unit is the last bun in the lane 18 .
[0025] A second bun detection unit 38 detects when all of the lanes have a sufficient number of buns 16 for passing to the packaging device 24 . Second bun detection unit 38 works in conjunction with bun holder 40 to release a predetermined number of buns from the laner 10 to the packaging device 24 and or a bun slicing device. The packaging device 24 may be of any standard design. Because the bun laner 10 provides a more even distribution of buns through the lanes, it may lessen the amount of pressure needed to mechanically hold a bun in place, since the necessary pressure is related to the number of buns in line being pushed forward by conveyor belt 37 .
[0026] FIG. 3 illustrates the lane impeder 22 (for a six lane unit). A vacuum unit 50 provides suction through hose 52 . The suction from hose 52 is diverted into six pipes 54 , each having a respective valve 56 . Each valve 56 is controlled by a respective sensor 58 on the detection unit 20 . Each valve is coupled to its respective lane 18 .
[0027] The valves 56 control whether a bun is allowed to pass or is held in place by the vacuum created by vacuum unit 50 . When a valve 56 is open, the vacuum from vacuum unit 50 holds the bun over the valve in place.
[0028] By selectively applying a vacuum to full lanes, the buns are held in place without damage to the bun and without a complicated mechanical structure to selectively shut of lanes.
[0029] FIG. 4 illustrates detailed top view of the sorting mechanism 14 . Wheel 36 is constantly rotated by a motor (not shown). A bar 60 has one end that is pivotally attached to the perimeter of wheel 36 and a second end which is pivotally coupled to sliding bar 62 . Sliding bar 62 is slideably engaged in carrier 64 . Responsive to the rotation of wheel 36 , the sliding bar 62 move back and forth in carrier 64 . Sliding bar 62 is coupled to the guides 34 , such that as sliding bar 62 oscillates back and forth, guides 34 oscillate back and forth as well.
[0030] In an alternative embodiment, a vibratory conveyor is used in the staging area 12 in place of conveyor belt 30 and sorting mechanism 22 . A vibratory conveyor is generally made of a smooth metal, such as stainless steel, and vibrates to move the food product, i.e., the buns 16 , forward towards the lanes. Because the staging area 12 with a metal surface is much smoother than a conveyor belt, there is less friction with the buns in staging area 12 , and the buns freely move around one another when one or more lanes are impeded by the vacuum.
[0031] Although the Detailed Description of the invention has been directed to certain exemplary embodiments, various modifications of these embodiments, as well as alternative embodiments, will be suggested to those skilled in the art. The invention encompasses any modifications or alternative embodiments that fall within the scope of the claims.
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A bun laner sorts buns into a predetermined number of lanes, for providing buns to a packaging unit. The bun laner detects when some lanes are filling faster than other and closes those lanes while the other lanes fill. A vacuum may be used to hold buns in a filled lane in order to close the lane. An optical detection unit may be used to determine when a bun has been stationary at a certain position in the lane for a predetermined amount of time.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of Invention
[0002] The present invention relates to a diverter assembly for shower, and more particularly to a diverter assembly for holding a shower nozzle, and for controlling the amount of water to flow out through either or both of a shower head and a shower nozzle steplessly.
[0003] 2. Related Art
[0004] Typical American shower appliances include a shower head fixed on a wall and a shower nozzle for a user to hold, and a diverter is disposed between the shower head and the shower nozzle for controlling the water to flow out through either or both of the shower head and the nozzle.
[0005] U.S. Pat. No. 7,299,510 discloses a holder device for a shower head and a shower nozzle as described above. The holder device includes an inlet and two outlet ports. A knob is pivotally disposed at one end of the holder device to operate a valve stem disposed inside the holder device for controlling the water flowing directions. An attaching device is disposed at the other end of the holder device for holding the shower nozzle.
[0006] The two outlet ports of the holder device pass through a chamber, and the valve stem switches a valve member to positions corresponding to either one of the two outlet ports or between the two outlet ports. That is to say, when the valve stem switches the valve member to the position corresponding to one of the outlet ports, the water flows out through the other outlet port. When the valve stem switches the valve member to the position between the two outlet ports, the water flows out through both of the outlet ports.
[0007] Although the above-mentioned controlling technique of the three valve stem positions satisfies basic needs of users, when the valve stem switches to the position to have the water flow out through both of the outlet ports, that is, when the water flows out through both of the shower head and the shower nozzle, users can not further adjust the amount of the water flowing out through both of the shower head and the shower nozzle. The above situation is obviously to be improved for users.
[0008] On the other hand, an attaching device for the shower nozzle to be attached thereto includes a follower rotatably disposed on a partition secured to the holder device for the attaching device to be rotated along with the follower and for the opening of the attaching device to change the angle so that users can handle the shower nozzle or attach it in the holder device.
[0009] However, there is nothing between the attaching device and the partition for securing the attaching device, and the securing of the attaching device comes from the friction among the follower, the attaching device and the partition. If the screw for securing the follower and the attaching device is loosen, or after being used for a long time, a wearing issue occurs among the follower, the attaching device and the partition such that the attaching device loses securing capability, resulting in the falling of the shower nozzle secured in the attaching device. The falling of the shower nozzle can result in damaging of the shower nozzle or other appliance, or more seriously, hurt users thereof. Therefore, the attaching device is needed to be improved further.
SUMMARY OF THE INVENTION
[0010] The primary object of the present invention is to solve the above-mentioned issues and to provide a diverter assembly for holding a handheld shower nozzle, and for controlling the amount of water to flow out through either or both of a shower head and the shower nozzle steplessly.
[0011] The secondary object of the present invention is to provide a multi-position movable body for securing the shower nozzle.
[0012] For achieving the above-mentioned objects, the diverter assembly according to the present invention includes a main body, a valve device and a movable body. The main body is hollow and has a water inlet tube and two water outlet tubes. One of the two water outlet tubes is communicated through a hose to a shower nozzle. The valve device is disposed on the main body and has a valve capable of linearly moving back and forth for steplessly communicating the water inlet tube with either or both of the water outlet tubes. The movable body is pivotally disposed at one end of the main body, and has a hole for the shower nozzle to be inserted in.
[0013] Accordingly, the diverter assembly can steplessly adjust the valve position for controlling the water to flow out from any of the water outlet tubes into either or both of the shower nozzle or the shower head, so as to achieve the object of steplessly adjusting the amount of water to flow out from the shower nozzle and the shower head.
[0014] Furthermore, the movable body has an elastic engagement member and a plurality of meshing parts corresponding to the engagement member. The engagement member is inserted into the meshing parts to locate the movable body for securing the shower nozzle.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a schematic view of a shower appliance according to the present invention;
[0016] FIG. 2 is a perspective view of the present invention;
[0017] FIG. 3 is a cross-sectional view along the III-III cross-sectional line in FIG. 2 ;
[0018] FIG. 4 is a cross-sectional structural schematic view of the present invention;
[0019] FIG. 5 is a schematic view showing a first operating condition of the present invention;
[0020] FIG. 6 is a schematic view showing a second operating condition of the present invention;
[0021] FIG. 7 is a schematic view showing a third operating condition of the present invention; and
[0022] FIG. 8 is a cross-sectional structural schematic view of a main body and a pivotally disposed movable body in the second preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0023] Refer to FIG. 1 to FIG. 7 , which shows a preferred embodiment according to the present invention.
[0024] Refer to FIG. 1 , which is a schematic view of a shower appliance according to the present invention. A shower appliance usually has a water outlet tube 11 protruding on top of a wall. The water flowing out of the water outlet tube 11 is controlled by a switch 12 disposed on bottom of the wall. The diverter assembly 2 of the present invention is integrated with the water outlet tube 11 , respectively communicated with a shower head 13 and communicated with a handheld shower nozzle 15 by a hose 14 .
[0025] Refer to FIG. 2 , which is a perspective view of the present invention. The diverter assembly 2 of the present invention has a hollow main body 20 . The main body 20 has a water inlet tube 21 , a first water outlet tube 22 and a second water outlet tube 23 . A knob 24 is pivotally disposed at one end of the main body 20 . The knob 24 rotates in accordance with a valve device 3 (referring to FIG. 4 ) disposed in the main body 20 , and the valve device 3 controls the water to flow out from the first water outlet tube 22 and the second water outlet tube 23 .
[0026] A movable body 4 is pivotally disposed at one end of the main body 20 opposing the knob 24 and has a hole 41 for the shower nozzle 15 to be inserted in, and the hole 41 has an opening 411 for a user to take or hang the shower nozzle conveniently.
[0027] Refer to FIG. 2 to FIG. 4 . FIG. 3 is a cross-sectional view along the III-III cross-sectional line in FIG. 2 . FIG. 4 is a cross-sectional structural schematic view of the present invention. A protruding part 25 is disposed at one end of the main body 20 opposing the knob 24 and has a ring groove 251 at an outer edge of the protruding part 25 . A container 252 is disposed at the center of the protruding part 25 . The protruding part 25 has at least one through hole 253 passing through the container 252 and the ring groove 251 . Two through holes 253 axially opposing each other are taken as an example in the present embodiment. The moveable seat 4 has a protruding ring 42 corresponding to the ring groove 251 . The protruding ring 42 has a plurality of meshing parts 421 spaced at intervals. An engagement member 43 is disposed in the container 252 , and is ring-shaped and made of an elastic material such as steel. The engagement member 43 has a protruding engagement part 431 corresponding to each through hole 253 respectively, and each engagement part 431 is protruding from the ring groove 251 and inserted in the meshing part 421 as shown in FIG. 3 for securing the movable body 4 effectively.
[0028] Refer to FIG. 4 . The valve device 3 in the hollow main body 20 has a first sleeve 31 and a second sleeve 32 sleeved by each other. A partition A is formed between the first sleeve 31 and the second sleeve 32 , and communicates a first passage A 1 and a second passage A 2 . Three O-rings 311 , 312 and 313 are disposed separately at an outer edge of the first sleeve 31 to form a first partition C 1 , a second partition C 2 and a third partition C 3 among the main body 20 , the first sleeve 31 and the second sleeve 32 . The first partition C 1 communicates with the water inlet tube 21 . The second partition C 2 communicates with the first water outlet tube 22 . The third partition C 3 communicates with the second water outlet tube 23 .
[0029] Further, the first sleeve 31 has a first through hole 314 communicating the first passage A 1 and the second partition C 2 for the first passage A 1 to communicate with the first water outlet tube 22 . The second sleeve 32 has a fourth partition C 4 communicating with the second passage A 2 and the third partition C 3 respectively, so that the second passage A 2 communicates with the second water outlet tube 23 .
[0030] A spiral sleeve 33 is slidably disposed at one end of the first sleeve 31 opposing the second sleeve 32 and integrated with an axis 34 . The axis 34 extends and passes the partition A and has a valve 35 at one section of the partition A. One end of the spiral sleeve 33 opposing the axis 34 is spirally engaged with a spiral rod 36 . The spiral rod 36 is pivotally disposed on the main body 20 by a cover 37 , and the section thereof extending out of the cover 37 is integrated with the knob 24 for the knob 24 to rotate the spiral rod 36 and further to slide the spiral sleeve 33 and the axis 34 .
[0031] Further, a container D is disposed at one end of the first sleeve 31 opposing the second sleeve 32 . A sliding groove 315 is disposed respectively at two axially opposite ends of the container D. A slider 331 is disposed respectively at the spiral sleeve 33 opposing the two sliding grooves 315 . The spiral sleeve 33 can slide relative to the first sleeve 31 by the cooperating of the two sliding grooves 315 and two sliders 331 .
[0032] Refer to FIG. 5 , which is a schematic view showing a first operating condition of the present invention. When a user rotates the knob 24 to slide the spiral sleeve 33 and the axis 34 toward the second passage A 2 until the valve 35 closes the second passage A 2 , the water flows in through the water inlet tube 21 and then enters the partition A through the first partition C 1 , and then flows through the first through hole 314 and the second partition C 2 from the first passage A 1 , and is finally sprayed from the shower head 13 through the first water outlet tube 22 .
[0033] Refer to FIG. 6 , which is a schematic view showing a second operating condition of the present invention. When a user wants the water to flow out of the shower nozzle 15 and rotates the knob 24 to slide the spiral sleeve 33 and the axis 34 toward the first passage A 1 until the valve 35 closes the first passage A 1 , the water flows into through the water inlet tube 21 and then enters the partition A through the first partition C 1 , and onto the third partition C 3 through the second passage A 2 and the fourth partition C 4 , and finally into the hose 14 through the second water outlet tube 23 to be sprayed from the shower nozzle 15 .
[0034] Refer to FIG. 7 , which is a schematic view showing a third operating condition of the present invention. When a user wants the water to flow out of the shower head 13 and the shower nozzle 15 simultaneously and rotates the knob 24 to slide the spiral sleeve 33 and the axis 34 until the valve 35 is located between the first passage A 1 and the second passage A 2 and the first passage A 1 communicates with the second passage A 2 , the water flows in through the water inlet tube 21 and then enters the partition A through the first partition C 1 , and onto the partition A through the first passage A 1 and the second passage A 2 , and is finally sprayed from of the shower head 13 and the shower nozzle 15 through the first water outlet tube 22 and second water outlet tube 23 , so that the water is sprayed from the shower head 13 and the shower nozzle 15 simultaneously.
[0035] If the user wants the amount of water flowing out from the shower nozzle 15 more than from the shower head 13 , the user can rotate the knob 24 to slightly slide the spiral sleeve 33 and the axis 34 toward the first passage A 1 so that the valve 35 is near the first passage A 1 and reduces the amount of water flowing from the first passage A 1 to the shower head 13 and increases the water flowing out from the shower nozzle 15 . Thereby, the location of the valve 35 is finely adjusted by the knob 34 to steplessly adjust the amount of water flowing out from the shower head 13 and the shower nozzle 15 .
[0036] Moreover, the hole 41 of the movable body 4 is for the shower nozzle 15 to be inserted in, and the movable body 4 is pivotally disposed on the main body 20 and is capable of rotating and locating. Thus, the movable body 4 can pivotally rotate to adjust the angle for a user to take or hang the shower nozzle 15 . The engagement part 431 of the engagement member 43 on the movable body 4 can be inserted into any meshing part 421 of the protruding ring 42 for locating the movable body 4 , such that the shower nozzle 15 is inserted securely in the movable body 4 and prevented from dropping as occurred in the prior art.
[0037] Refer to FIG. 8 , which is a cross-sectional structural schematic view of a main body and a pivotally disposed movable body in the second preferred embodiment of the present invention. A protruding part 25 A of the main body has a ring groove 251 A, and the movable body 4 A has a protruding ring 42 A corresponding to the ring groove 251 A. A container 252 A is disposed concavely at an outer edge of the ring groove 251 A, and has an engagement member 43 A and a spring 44 A disposed therein. In a normal condition, the spring 44 A presses the engagement member 43 A to protrude from the ring groove 251 A. The protruding ring 42 A has a plurality of meshing parts 421 A corresponding to the engagement member 43 A, so that the spring force of the spring 44 A presses the engagement member 43 A to be inserted into the meshing part 421 A for locating the movable body effectively. Accordingly, the present embodiment achieves the same effect as in the first embodiment.
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A diverter assembly includes a main body, a valve device and a movable body. The main body is hollow and has a water inlet tube and two water outlet tubes. One of the two water outlet tubes is communicated through a hose to a shower nozzle. The valve device is disposed on the main body and has a valve capable of linearly moving back and forth for steplessly communicating the water inlet tube with either or both of the water outlet tubes. The movable body is pivotally disposed at one end of the main body, and has a hole for the shower nozzle to be inserted in. Thereby, the diverter assembly can steplessly adjust the valve position for controlling the water to flow out from either or both of the water outlet tubes.
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TECHNICAL FIELD
[0001] The technical field generally relates to fuel cells and in particular to fuel delivery system for liquid-type fuel cells.
BACKGROUND
[0002] A fuel cell is an electrochemical apparatus wherein chemical energy generated from a combination of a fuel with an oxidant is converted to electric energy in the presence of a catalyst. The fuel is fed to an anode, which has a negative polarity, and the oxidant is fed to a cathode, which, conversely, has a positive polarity. The two electrodes are connected within the fuel cell by an electrolyte to transmit protons from the anode to the cathode. The electrolyte can be an acidic or an alkaline solution, or a solid polymer ion-exchange membrane characterized by a high ionic conductivity. The solid polymer electrolyte is often referred to as a proton exchange membrane (PEM).
[0003] In fuel cells employing liquid fuel, such as methanol, and an oxygen-containing oxidant, such as air or pure oxygen, the methanol is oxidized at an anode catalyst layer to produce protons and carbon dioxide. The protons migrate through the PEM from the anode to the cathode. At a cathode catalyst layer, oxygen reacts with the protons to form water. The anode and cathode reactions in this fuel cell are shown in the following equations:
Anode reaction (fuel side): CH 3 OH+H 2 O→6H + +CO 2 +6e − (I)
Cathode reaction (air side): 3/2 O 2 +6H + +6e − →3H 2 O (II)
Net: CH 3 OH+3/2O 2 →2H 2 O+CO 2 (III)
[0004] One of the essential requirements of a fuel cell is efficient delivery of fuel to the electrodes. U.S. Pat. No. 5,631,099 describes a typical microchannel and plumbing design that facilitates the flow of fuel and removal of water during fuel cell operation. U.S. Pat. Nos. 5,766,786 and 6,280,867 describe pumping systems to accurately and reproducibly deliver the fuel to the electrodes. All these devices have complex arrangements of membrane, gaskets, channels that are difficult and expensive to fabricate and assemble, and are highly subject to catastrophic failure of the entire system if a leak develops. As can be easily appreciated, the cost of fabricating and assembling fuel cells is significant, due to the materials and labor involved. Typically, 85% of a fuel cell's cost is attributable to manufacturing costs. Thus, the complexity of prior art fuel cell structures is one of the factors preventing widespread acceptance of fuel cell technology. An improved style of fuel cell that is less complex and less prone to failure would be a significant addition to the field. With regard to fuel delivery systems in particular, there is a continuing need for a delivery system that can efficiently deliver fuels in a cost effective manner. A passive fuel delivery system with no plumbing and pumps would be highly desirable in applications such as portable fuel cells.
SUMMARY
[0005] A method for delivering liquid fuel to a reaction surface in a fuel cell is disclosed. The liquid fuel is passively delivered to the reaction surface of an electrode by capillary force through an effective porous structure.
[0006] In an embodiment, the effective porous structure is inserted inside a fuel storage space of a fuel cell and delivers fuel to an electrode of the fuel cell through capillary effect.
[0007] In another embodiment, the effective porous structure is a part of a fuel cartridge. The fuel cartridge can be loaded into a cartridge holder in a fuel cell.
[0008] Additional advantages and novel features 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 or may be learned by practice of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The detailed description will refer to the following drawings, in which like numerals refer to like elements, and in which:
[0010] [0010]FIG. 1 is a schematic showing the capillary effect.
[0011] [0011]FIGS. 2A and 2B are schematics of porous structures for fuel delivery in a fuel cell.
[0012] [0012]FIG. 3 depicts a porous structure as part of a fuel cartridge.
[0013] [0013]FIGS. 4A, 4B and 4 C depict an embodiment of fuel flow control between a fuel cartridge and a fuel cell.
[0014] [0014]FIGS. 5A and 5B depict another embodiment of fuel flow control between a fuel cartridge and a fuel cell.
DETAILED DESCRIPTION
[0015] A passive fuel delivery system using capillary effect to deliver fuel to a reaction surface is disclosed. Capillary effect is the spontaneous rise of a liquid in a fine tube due to adhesion of the liquid to the inner surface of the tube and cohesion of the adhered liquid to and among other liquid molecules. FIG. 1 shows capillary effect in tubes of different sizes. As depicted, capillary rise is related to the diameter of tubes 101 . The smaller is the tube diameter, the greater is the rise of a liquid column 103 from a liquid table 105 . When a porous structure, such as a foam, is placed into a fuel container, the capillary effect of the small-diameter pores in the foam will cause the fuel to rise above the fuel level to form a capillary fringe in the foam. Typically, the capillary fringe is composed of pores of various sizes, from macropores to micropores. At the base of the capillary fringe, all the pores are saturated by the fuel. At the top of the capillary fringe, saturation by fuel is limited to only the micropores.
[0016] Capillary rise of fuel in a foam can be represented by the following equation:
ρ gh=[ 2σ cos θ e ]/r e =P c
[0017] where ρ is the density of the fuel, g is the gravitational constant, and h is the height the fuel has risen above the fuel level in a container in which the foam is standing. The symbol σ represents the surface tension of the fuel, θ e is the effective equilibrium wetting angle of the fuel on the surface of the foam, r e is the effective pore radius of the foam, and P c represents the capillary pressure. For any given fuel, ρ and g are both constant, and therefore h is inversely proportional to the pore radius r e , i.e., the smaller the pores are, the higher the fuel rises. In addition, a reduction of the wetting angle θ e of the fuel on the foam will improve or increase the height that the fuel rises in the foam, assuming all other parameters remain constant. The wetting angle θ e can be reduced by increasing the surface energy of surfaces throughout the foam. The surface energy can be increased by subjecting the foam to a free radical oxidation plasma process.
[0018] [0018]FIG. 2A depicts an embodiment of the fuel delivery system. In this embodiment, porous structure 201 is in the shape of a hollow tube so that the porous structure 201 can be inserted into outer cavity 207 , which serves as fuel container for a flex based fuel cell 200 . An inner surface 203 of the porous structure 201 is pressed against fuel electrodes 211 so that fuel can be delivered directly to reaction surfaces 213 of the fuel electrodes 211 .
[0019] Typically, the porous structure 201 is in the form of a felted piece of polyurethane foam or other suitable porous materials. The foam is thermally compressed, or felted, until the foam holds a compression set at a desired compression ratio. During a thermal compressing process, the foam is heated close to its melting point under a compression loading and allowed to thereafter cool, resulting in a denser foam with an increased porosity. When so felted, the foam achieves an effective porosity.
[0020] Alternatively, As shown in FIG. 2B, the flex based fuel cell 200 ′ may be configured in such a way that the fuel electrodes 211 face the inner cavity 209 . In this case, the porous structure 201 may be in the shape of a cylinder that can be inserted inside the inner cavity 209 of the flex based fuel cell 200 . The outer surface 205 of the porous structure 201 is pressed against the reaction surfaces 213 of the fuel electrodes 211 .
[0021] In both configurations, the capillary force at the surface of the porous structure 201 that contacts the electrodes 211 is higher than the capillary force in the other parts of the porous structure 201 , so that fuel will be drawn to the electrodes 211 . The higher capillary force can be achieved by (1) reducing the pore radius by increasing foam density, (2) reducing the wetting angle by increasing the surface energy of the foam, or both. Foam density can be increased by packing the foam denser along the outside peripheral of the porous structure 201 . Surface energy of the foam can be increased by diffusing a chemically active species into the interior portion of a bulk polymer foam by subjecting the foam surface to special treatments such as a gas plasma process. The smaller pores in denser foam or reduced wetting angle will ensure that the fuel is drawn to the electrodes 211 by the higher capillary force, so that in the embodiment of FIG. 2B, even when the fuel inside the inner cavity 217 of the porous structure 201 starts to deplete, the fuel will still be transported to the electrodes 211 for efficient fuel utilization.
[0022] As can be appreciated by one skilled in the art, the foam insert 201 is designed for easy replacement and can be configured into any shape to adapt to different fuel cell configurations.
[0023] In another embodiment, the foam insert is used as a fuel cartridge 305 . As shown in FIG. 3, fuel 302 is contained inside a sealed foam cylinder 301 , which is kept in a non-permeable container 303 or is wrapped with a non-permeable material. When needed, the cylinder 301 is taken out from the container 303 or from the wrapping material and is loaded into a cartridge holder 304 of a fuel cell 200 . In yet another embodiment, the fuel cylinder 301 is tightly wrapped with a non-permeable material to form cartridge 305 , which can be directly loaded into a fuel cell 200 without removing the wrapping thereby avoiding leakage of fuel from the cylinder 301 during the loading process.
[0024] The fuel in the cartridge 305 enters the fuel cell 200 through one or more connectors 307 (FIG. 4A). The connector 307 can be in different shapes and sizes. Typically, the connector 307 is made of foam materials that provide higher capillary force than the rest of the fuel cartridge, so that fuel in the cartridge 305 will be drawn to the connector 307 by the capillary force. In one embodiment, the connector 307 is in the shape of a short tubing and is located at the bottom of the fuel cartridge 305 (FIG. 4A).
[0025] When the fuel cartridge 305 is loaded into the fuel cell 200 , a needle-like receptacle 309 in the fuel cell 200 penetrates the non-permeable wrapping material at the end of the connector 307 . The base of the receptacle 309 is connected to the electrodes 211 through a porous material that establishes a capillary passage way between the fuel cartridge 305 and the electrodes 211 (FIG. 4B). In this embodiment, the needle-like receptacle 309 is also made of a porous material so that the fuel flow can be controlled by the size of a contact area between the needle-like receptacle 309 and the connector 307 (FIG. 4C). As shown in FIG. 4B, the fuel flow rate between fuel cartridge 305 and fuel cell 200 is controlled by positioning the fuel cartridge 305 at the high, medium, or low mark on the side of the cartridge 305 .
[0026] Generally, the needle-like receptacle 309 is made of a porous material having a capillary force that is stronger than the capillary force in the connector 307 , while the porous material in contact with the electrode 211 has a capillary force that is stronger than capillary force in receptacle 309 . This capillary force gradient ensures that the fuel inside the fuel cartridge 305 flows preferentially to the connector 307 , then to the receptacle 309 , and finally to the electrode 211 .
[0027] In another embodiment, a controller 311 is located at the bottom of the fuel cell 200 (FIG. 5A). The fuel flows from the cartridge 305 to the fuel cell 200 through the contact between the connector 307 and receptacle 309 , which is connected to electrodes by porous materials. The controller 311 controls a cross sectional area of the connector 307 by applying a pressure to the connector 307 through a screw 313 (FIG. 5B). A fuel flow is restricted by advancing the screw 313 towards the connector 307 , thereby reducing the cross sectional area of the connector 307 .
[0028] Alternatively, the fuel flow from the cartridge 305 to fuel cell 200 can be controlled by a conventional electromagnetic valve.
[0029] Although embodiments and their advantages have been described in detail, various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the fuel delivery system as defined by the appended claims and their equivalents.
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Fuel delivery system and method for delivering liquid fuel to an electrode in a liquid-type fuel cell are disclosed. The liquid fuel is passively delivered to a reaction surface of an electrode by capillary force through a porous structure. The porous structure has a shape and a capillary force distribution to facilitate fuel flow, and can be part of a fuel cartridge for easy transportation and storage of fuel.
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This application is a continuation-in-part of U.S. patent application Ser. No. 07/243,743, filed Sep. 13, 1988, now abandoned.
FIELD OF THE INVENTION
The invention relates to pharmaceutical preparations for topical application comprised of one or more stabilized, therapeutically active proteins and optional conventional excipients, carriers and additives. The invention also relates to a process for preparing these pharmaceutical preparations and the use of physiologically acceptable hydrophobic substances for the stabilization of proteins.
BACKGROUND OF THE INVENTION
One of the essential requirements in the topical application of therapeutically active proteins is their stability in the pharmaceutical formulation. The stability must be ensured for a sufficiently long period of time both during storage under refrigeration and at ambient temperature and also at body temperature, as well as "in situ" for several hours. Thus far, no entirely satisfactory solutions have been found to meet these requirements. Various substances for stabilizing interferons have already been proposed. For example, hydroxyethylcellulose has been used as a carrier substance for the preparation of gels or ointments containing interferon. However, under the conditions of use, there was some loss of activity of the interferons which could only be reduced by the addition of a protease inhibitor (EP-A-142345).
For the stabilizing of interferons in gels, ointments, etc., it has also been proposed to use various sugar alcohols, optionally together with sugar acids or the salts thereof, mild reducing agents, anionic surfactant or combinations of these substances (EP-A-80879).
For stabilizing proteins and polypeptides such as interferons, more particularly IFN-gamma, in parenteral preparations, it has been proposed to use a physically and chemically modified gelatin, particularly as a replacement for human serum albumin (EP-A-162332).
Japanese Published Patent Application JP-A-61-277633 discloses the stabilizing of interferons in solution with certain surface-active substances.
EP-A-135171 mentions human serum albumin as a suitable stabilizer for oil/water microemulsions.
For the topical application of the synergistic combination IFN-beta/9-(1,3-dihydroxy-2-propoxy-methylguanine (DHPG) in the form of an ointment, according to U.S. Pat. No. 4,606,917, albumin, dextrose and buffer substances are proposed as stabilizers.
A stabilizing effect to the standard required has not yet been achieved with the substances proposed thus far for stabilizing therapeutically active proteins, particularly in hydrogels.
The aim of this invention was to provide a stabilizer for therapeutically active proteins in pharmaceutical preparations for topical use, particularly in hydrogels, which in addition to being physiologically acceptable, satisfies all the requirements imposed on formulations of this kind, especially with respect to the optimum availability of the active substance and the full development of its activity and with respect to the gentlest possible method of preparation which takes account of the vulnerability of the proteins to shear forces.
Various substances have been investigated with respect to their suitability for solving the above-described problem. It was found, surprisingly, that even small amounts of hydrophobic substances used as additives in very finely divided form, particularly paraffin oils, have a stabilizing effect on various therapeutically active proteins which is superior to the effect of the substances proposed up till now. This result is all the more surprising as the pharmaceutical preparations for topical use which belong to the prior art, such as ointments in which hydrophobic substances are used as carriers in a suitably large proportion, require the separate addition of a stabilizer.
SUMMARY OF THE INVENTION
The invention relates to the use of physiologically acceptable hydrophobic substances, particularly paraffin oils, for stabilizing the therapeutically active proteins in pharmaceutical preparations for topical use, especially hydrogels. With the aid of the addition of a stabilizing quantity of hydrophobic substances in finely divided form, pharmaceutical preparations are obtained which, under the conditions of use, make the active substance available in active form over a lengthy period of time. By means of the pharmaceutical preparations according to the invention, the level of activity of the protein after a storage at 4°-8° C. over a period of at least 12 months is substantially unchanged. A further advantage of the formulations according to the invention is that there is less need to ensure that an exact pH value is maintained since the stabilizing addition of hydrophobic substances reduces the vulnerability of the proteins to fluctuations in the pH value. This advantage is of particular importance for applications which require lower pH values, e.g. application in the vaginal area.
The pharmaceutical preparation according to the invention also has the advantage, when present in the form of a hydrogel, of being extremely pleasant to use. This is because, even after the gel has dried, the presence of the hydrophobic substance ensures that the coating applied is soft to the touch, which is a particular advantage for application in the lip area.
The advantageous stabilizing effect of hydrophobic substances on proteins can possibly be put down to hydrophobic interactions which have hitherto been noticed scarcely or not at all. In the stabilizing of proteins according to the prior art, the following two operating principles were taken as a starting point: a) stabilizing by complex binding of the substance to the protein and hence steric fixing of the protein molecule; b) binding of the free bulk water by polar substances and hence stabilizing of the protein by influencing its hydrate coat. The hydrophobic interactions which presumably come into play in the present invention and which also occur in micellar structures occur around the time of stabilization by virtue of the fact that the hydrophobic regions of the protein which are created by the spatial distribution of the hydrophobic and hydrophilic amino acid groups are fixed to the oil/water phase interface so that the hydrophobic regions project into the oil droplet and the hydrophilic parts project into the polar phase.
BRIEF DESCRIPTION OF THE FIGURES
FIGS. 1-6 show the results of storage experiments with the various formulations described in the examples.
FIG. 1 shows that the addition of paraffin oil to the formulation disclosed in Example 1 ensures that the activity of IFN-gamma measured by the ELISA test (the antibodies used bind biologically active proteins for which they are specific) is maintained. The slight drop shown in the diagram is not significant in view of the test distribution.
FIG. 2 shows a comparison test with gelatine as a constituent of hydrogel formulation without the separate addition of a stabilizer.
FIG. 3 shows the stability curve over a period of 15 months for the hydrogel formulation described in Example 1.
FIG. 4 shows the stability curve for the hydrogel formulation described in Example 1.
FIG. 5 shows the curve of a comparison test in which the formulation described in Example 1 was used without any added paraffin oil. The results of the comparison test show a drop in stability shortly after manufacture.
FIG. 6 shows the stability curve for the formulation described in Example 11.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention thus relates to pharmaceutical preparations of the type mentioned above which are characterized in that they contain one or more physiologically acceptable hydrophobic substances, particularly paraffin oil or oils, in finely divided form in a quantity sufficient to stabilize the protein.
Suitable hydrophobic substances include, in addition to the preferred paraffin oils, higher fatty acids such as linoleic acid and palitic acid, or higher alcohols such as myristyl alcohol, or fatty acid esters such as triglycerides, or polyoxyethylenated and glycosylated glycerides (Labrafil®), individually or in admixture. Of the paraffin oils, liquid, thin-liquid or thick-liquid paraffin oil according to Ph. Eur. and USP or mixtures thereof are suitable. The hydrophobic substances are preferably contained in the preparation in an amount of from 0.1% to 3.0%.
In order to ensure that the stabilizer is finely divided and the distribution is stable, emulsifiers may be added. The quantity used will depend particularly on the nature and quantity of stabilizer, the carrier used and, in the case of hydrogels, the viscosity thereof. In general, the quantity of the stabilizer is not more than 1%. Preferred emulsifiers include, in particular, non-ionic emulsifiers such as polysorbates (polyoxyethylene(n)-nonylphenylether), e.g. TritonR N101, TritonR N111, and poloxamer (polyethylenepolypropyleneglycol, PluronicR F68). If the pharmaceutical preparation is in the form of a hydrogel, the emulsifiers will not only bring about a fine distribution of the stabilizer but will also improve the spreading of the gels.
The pharmaceutical preparations according to the invention are suitable for the administration of human and animal proteins such as those listed as follows, including their structurally similar bioactive equivalents (by equivalents is meant those proteins which have substantially the same biological activity with a different amino acid sequence): cytokines, e.g. interferons such as huIFN-alpha, huIFN-beta, huIFN-gamma, huIFN-omega, hybrid interferons, animal interferons such as EqIFN-beta, EqIFN-gamma, or lymphokines such as interleukin-2, TFNbeta, or monokines such-as interleukin-1, TNFalpha; growth factors, e.g. epidermal growth factor (EGF); anticoagulants, e.g. vascular anti-coagulant proteins (e.g. VAC alpha, VAC beta), antithrombins; fibrinolytics, e.g. tPA, urokinase; proteins with an anti-allergic activity, e.g. IgE binding factor; therapeutically active enzymes, e.g. lysozyme, superoxide dismutases. The proteins used may either be of natural origin or produced by the recombinant method. A "functional derivative" of a protein is a compound which possesses a biological activity (either functional or structural) that is substantially similar to a biological activity of the protein. The terms "functional derivative" are intended to include the "fragments," "variants," "analogues," or "chemical derivatives" of the protein. The terms "functional derivative" are also intended to include glycoproteins corresponding to the protein which are present in animals, including humans. A "fragment" is meant to refer to any polypeptide subset of the protein molecule. A "variant" is meant to refer to a molecule substantially similar in structure and function to either the entire molecule, or to a fragment thereof. A molecule is said to be "substantially similar" to another molecule if both molecules have substantially similar structures or if both molecules possess a similar biological activity. Thus, provided that two molecules possess a similar activity, they are considered variants as that term is used herein even if the structure of one of the molecules is not found in the other or if the sequence of amino acid residues is not identical. An "analog" is meant to refer to a molecule substantially similar in function to either the entire molecule or to a fragment thereof. As used herein, a molecule is said to be a "chemical derivative" of another molecule when it contains additional chemical moieties not normally a part of the molecule. Such moieties may improve the molecule's solubility, absorption, biological half life, etc. The moieties may alternatively decrease the toxicity of the molecule, eliminate or attenuate any undesirable side effect of the molecule, etc. Moieties capable of mediating such effects are disclosed in Remington's Pharmaceutical Sciences (1980). Procedures for coupling such moieties to a molecule are well known in the art. The range of indications depends on the biological activity of the protein which is to be applied; within the specific spectrum for each protein, any application is possible which requires topical administration of the active substance. The content of therapeutically active protein in the pharmaceutical preparation will naturally depend on the activity of the protein, the needs of the particular indication and the type of preparation used. It may span a wide range of quantities.
Suitable forms for administration include, in particular, hydrogels, suppositories and forms for vaginal use.
The use of excipients, carriers and additives will depend on the particular application selected, as care should be taken to ensure that they do not affect the stability of the protein by the type and quantity used. The carrier used will also depend on the form of administration; when the pharmaceutical preparation takes the form of a hydrogel, the carrier is water. Other excipients known in the art are fillers such as saccharides, for example, lactose or sucrose, mannitol or sorbitol cellulose preparations and/or calcium phosphates, for example, tricalcium phosphate or calcium hydrogen phosphate, as well as binders such as starch paste, using for example, maize starch, wheat starch, rice starch, potato starch, gelatin, tragacanth, methyl cellulose, hydroxypropylmethylcellulose, sodium carboxymethylcellulose, and/or polyvinyl pyrrolidone. In some cases, it may be desirable to add disintegrating agents such as the above-mentioned starches and also carboxymethyl-starch, cross-linked polyvinyl pyrrolidone, agar, or alginic acid or a salt thereof, such as sodium alginate. Auxiliaries are, above all, flow-regulating agents and lubricants, for example, silica, talc, steric acid or salts thereof, such as magnesium stearate or calcium stearate, and/or polyethylene glycol. The preferred carrier for the present invention is water.
The pharmaceutical preparations according to the invention may contain, as additives, preservatives such as p-hydrobenzoates (nipa esters, methylparaben), sorbic acid, chlorhexidine digluconate, benzalkonium chloride and hexadecyltrimethyl ammonium bromide.
In order to accelerate the absorption of the active substance through the skin, permeation accelerators such as dimethylsulfoxide or tauroglycolic acid may be added to the pharmaceutical preparation.
Hydrogel forming agents which may be used include gelatine and cellulose derivatives such as methylcellulose, hydroxypropylcellulose and, in a particularly preferred embodiment, hydroxyethylcellose, as well as synthetic polymers such as polyvinyl alcohol. The nature and quantity of the hydrogel forming agents used or the mixtures thereof will depend on the particular viscosity required. With regard to the fine distribution of the stabilizer, it should be noted that when the gel has a higher viscosity, the stability of the emulsion is, under certain circumstances, adequately ensured by the content of a hydrogel forming agent and therefore there is no need to add an emulsifier. The buffer systems used are selected according to the optimum pH for the particular protein and matched to the particular application; both organic and inorganic buffers may be used, e.g. succinate, acetate and phosphate buffers.
The additives which may be present also include moisture-retaining substances such as glycerol, sorbitol, 1,2-propyleneglycol, butyleneglycol and polyols.
The preparations in the form of hydrogels according to the invention are so-called "low-filled" emulsions, because of their low oil content, which tend to break down easily, as is well known. The preparation of these emulsions is, therefore, of particular importance with regard to their stability.
A two-step process is preferably used in the manufacture of the preparations according to the invention, particularly hydrogels.
In the first step, in a system of water/stabilizer/optionally emulsifier, a phase inversion from a W/O emulsion to an O/W emulsion is brought about and the fine pre-emulsion thus obtained is combined with the majority of the aqueous phase.
The following procedure is particularly preferred: first, a pre-emulsion is produced by the so-called "continental" method, the emulsifier is distributed in the paraffin oil and water is slowly added until a very coarse W/O emulsion is formed. At this stage, which is reached when the water content is about 20%-40%, according to our experiments, the mixing process is broken off and the emulsion is briefly allowed to settle. When mixing is subsequently resumed and water is added up to a content of about 50%, the emulsion is inverted to form a fine O/W emulsion. During the second step of the process, the pre-emulsion obtained is stirred into the buffer solution and dispersed, after which the hydrogel forming agent is added and allowed to swell. The time at which the protein solution is added is not critical; this is preferably the final step of the process. Using the preferred process according to the invention, extremely stable emulsions are obtained which show no tendency to separate after half a year's storage at room temperature.
In the case of smaller quantities or when technically more complicated homogenizers such as nozzle homogenizers are available, an O/W emulsion may also be produced in a single step without the preparation of a premulsion; however, the process which is preferred according to the invention provides a method of manufacture which not only produces a stable emulsion but is also simple, requires little energy or complex technology and is at the same time gentle.
The Examples which follow are intended to illustrate the invention with reference to hydrogel formulations containing IFN alpha, IFN gamma lysozyme, vac-a and TNF alpha as the therapeutically active protein:
EXAMPLE 1
100 grams of gel contain:
______________________________________IFN gamma 0.2 gMethylparaben 0.2 gSodium dihydrogen phosphate monohydrate 0.05 gDipotassium hydrogen phosphate trihydrate 0.04 gNatrosol 250 HX (hydroxyethylcellulose) 1.75 gPolysorbate 20 0.1 gThin-liquid paraffin oil 1.0 gDeionized water ad 100 g 96.76 g______________________________________
The hydrogel was produced by the preferred two-step method:
a) Preparation of the Pre-emulsion
The phosphates and the preservative, methylparaben, were dissolved in hot water at 80° C., with stirring, and the solution was then cooled to ambient temperature. The emulsifier polysorbate 20 was distributed in the paraffin oil using a fast-rotating homogenizer. Sufficient water was added slowly, with stirring, to produce an approximately 30% coarse W/O emulsion. This emulsion was briefly left to stand, whereupon it separated. After the stirrer was switched on again the emulsion was brought to the point of phase inversion, to produce a very finely divided O/W emulsion.
b) Preparation of the Hydrogel
The paraffin oil emulsion was stirred into the sterile-filtered buffer solution and finely divided therein. Then microbiologically pure hydroxyethylcellulose was sprinkled into the emulsion and distributed therein with stirring. To obtain total swelling, the gel was left to swell for 10-15 hours under laminar flow. Finally, the IFN gamma solution, adjusted to 4 mg/ml, was slowly stirred in. This mixture was transferred into sterile tubes under laminar air flow conditions.
The course of the storage experiments is shown in FIG. 1. As can be seen from the diagram, the addition of paraffin oil ensures that the activity of IFN-gamma, measured by the ELISA test (the antibodies used bind biologically active proteins for which they are specific) is maintained; the slight drop shown in the diagram is not significant in view of the test distribution.
FIG. 2 shows a comparison test with gelatine as a constituent of a hydrogel formulation without the separate addition and showing the clearly destabilizing effect of gelatine on IFN-gamma. Consequently, when gelatine is used as a hydrogel forming agent, the addition of an effective stabilizer is absolutely essential.
FIG. 3 shows the stability pattern over a period of 15 months (in this diagram and in FIGS. 4, 5 and 6, the log.nat. of the concentration of the therapeutically active protein is shown on the y axis).
EXAMPLE 2
100 g of gel contain:
______________________________________IFN gamma 0.1 gMethylparaben 0.2 gSodium dihydrogen phosphate monohydrate 0.05 gDipotassium hydrogen phosphate trihydrate 0.04 gNatrosol 250 HX 1.75 gPluronic F68 0.1 gThin liquid paraffin oil 1.0 gDeionized water ad 100 g 96.76 g______________________________________
The phosphates, the preservative methylparaben and the emulsifier Pluronic F68 were dissolved in hot water at 80° C. with stirring, and the solution was then cooled to ambient temperature and filtered to sterilize it. The paraffin oil was introduced and distributed therein by means of an homogenizer. Then the hydroxyethylcellulose was added with stirring in vacuo. Finally, the IFN-gamma solution, adjusted to 4 mg/ml, was added. The mixture was transferred as described in Example 1.
EXAMPLE 3
100 g of gel contain:
______________________________________TNF alpha 0.1 gMethylparaben 0.213 gSodium dihydrogen phosphate monohydrate 0.053 gDipotassium hydrogen phosphate trihydrate 0.0427 gNatrosol 250 HX 1.87 gPolysorbate 20 0.107 gThin liquid paraffin oil 1.07 gDeionized water ad 100 g 96.5443 g______________________________________
The hydrogel was prepared as described in Example 1.
EXAMPLE 4
100 g of gel contain:
______________________________________IFN alpha 0.0005 gMethylparaben 0.2 gSodium dihydrogen phosphate monohydrate 0.05 gDipotassium hydrogen phosphate trihydrate 0.04 gNatrosol 250 HX 1.75 gPolysorbate 20 0.1 gThin liquid paraffin oil 1.0 gDeionized water ad 100 g 96.8595 g______________________________________
The hydrogel was prepared as described in Example 1.
EXAMPLE 5
100 g of gel contain:
______________________________________IFN gamma 0.100 gMethylparaben 0.2 gSodium dihydrogen phosphate monohydrate 0.05 gDipotassium hydrogen phosphate trihydrate 0.04 gTauroglycolic acid 0.01 gNatrosol 250 HX 1.75 gPolysorbate 20 0.1 gThin liquid paraffin oil 1.0 gDeionized water ad 100 g 96.75 g______________________________________
The hydrogel was prepared as in Example 1 and tauroglycolic acid was stirred into the buffer solution as a permeation accelerator.
EXAMPLE 6
100 g of gel contain:
______________________________________IFN gamma 0.05 gMethylparaben 0.2 gSodium dihydrogen phosphate monohydrate 0.05 gDipotassium hydrogen phosphate trihydrate 0.04 gNatrosol 250 HX 1.75 gPolysorbate 20 0.1 gThin liquid paraffin oil 0.6 gThick liquid paraffin oil 0.4 gDeionized water ad 100 g 96.81 g______________________________________
The hydrogel was prepared as described in Example 1.
EXAMPLE 7
100 g of gel contain:
______________________________________IFN gamma 0.05 gMethylparaben 0.2 gSodium dihydrogen phosphate monohydrate 0.05 gDisodium hydrogen phosphate trihydrate 0.04 gNatrosol 250 HX 1.75 gMyristyl alcohol 1.0 gDeionized water ad 100 g 96.91 g______________________________________
The hydrogel was prepared as described in Example 2.
The myristyl alcohol was distributed in the sterile-filtered buffer solution which had been heated to about 60° C. After the buffer solution had cooled, the procedure was continued as described in Example 2.
EXAMPLE 8
100 g of gel substance contain:
______________________________________IFN gamma 0.005 gMethylpraben 0.20 gSuccinate buffer pH 6.00 0.0191 MSodium chloride 0.1435 MNatrosol 250 HX 1.75 gPolysorbate 20 0.0952 gThin liquid paraffin oil 0.952 gDeionized water ad 100 g______________________________________
The hydrogel was prepared as described in Example 1. The stability curve is shown in FIG. 4. FIG. 5 shows the curve of a comparison test in which the same formulation was used without any added paraffin oil. The results of the comparison test show a drop in stability shortly after manufacture.
EXAMPLE 9
100 g of gel substance contain:
______________________________________IFN gamma 0.025 gMethylparaben 0.20 gSuccinate (buffer pH 6.2) 0.2362 gSodium chloride 0.8766 gNatrosol 250 HX 1.75 gPolysorbate 20 0.1 gLABRAFIL 1944 CS 1.0 gDeionized water ad 100 g______________________________________
The hydrogel was prepared as described in Example 1.
EXAMPLE 10
100 g of gel substance contain:
______________________________________IFN gamma 0.025 gMethylparaben 0.20 gSuccinate (buffer pH 6.2) 0.2362 gSodium chloride 0.8766 gNatrosol 250 HX 1.75 gPolysorbate 20 0.1 gLABRAFIL 2735 CS 1.0 gDeionized water ad 100 g______________________________________
The hydrogel was prepared as described in Example 1.
EXAMPLE 11
100 g of gel substance contain:
______________________________________IFN gamma 0.025 gMethylparaben 0.20 gSuccinate (buffer pH 6.2) 0.2362 gSodium chloride 0.90 gNatrosol 250 HX 1.75 gPolysorbate 20 0.1 gMyristyl alcohol 1.0 gDeionized water ad 100 g______________________________________
The hydrogel was prepared as follows: the myristyl alcohol was melted at 50°-60° C. and then the premulsion was prepared as described in Example 1 but at 50°-60° C. The rest of the method was as in Example 1. The stability curve is shown in FIG. 6.
EXAMPLE 12
100 g of gel substance contain:
______________________________________TNF beta 0.05 gMethylparaben 0.2 gSodium dihydrogen phosphate monohydrate 0.05 gDipotassium hydrogen phosphate trihydrate 0.04 gNatrosol 250 HX 1.75 gPolysorbate 20 0.2 gThin liquid paraffin oil 2.0 gDeionized water ad 100 g______________________________________
The hydrogel was prepared as described in Example 1.
EXAMPLE 13
______________________________________Lysozyme 2.4 million unitsMethylparaben 0.2 gSodium dihydrogen phosphate monohydrate 0.05 gDipotassium hydrogen phosphate trihydrate 0.04 gNatrosol 250 HX 1.75 gPolysorbate 20 0.2 gThin liquid paraffin oil 2.0 gDeionized water ad 100 g______________________________________
The hydrogel was prepared as in Example 1.
EXAMPLE 14
100 g of gel substance contain:
______________________________________VAC alpha 0.03 gMethylparaben 0.2 gSodium dihydrogen phosphate monohydrate 0.05 gDipotassium hydrogen phosphate trihydrate 0.04 gNatrosol 250 HX 1.75 gPolysorbate 20 0.1 gThin liquid paraffin oil 1.0 gDeionized water ad 100 g______________________________________
The hydrogel was prepared as in Example 1.
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This invention relates to pharmaceutical preparations for topical application containing one or more stabilized therapeutically active proteins and optional conventional excipients, carriers and additives, and a process for preparing pharmaceutical preparations of this kind and the use of physiologically acceptable hydrophobic substances for stabilizing proteins.
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This application is related to the application entitled "Building Systems with Non-Regular Polyhedra Based on Subdivisions of Zonohedra", Ser. No. 07/740,504 dated Aug. 5, 1991 which is a CIP of a Division of Ser. No. 07/428,018 dated Oct. 26, 1989 (U.S. Pat. No. 5,036,635), which is a Continuation of Ser. No. 07/319,861 dated Mar. 6, 1989 which is a Continuation of Ser. No. 07/088,308 dated Aug. 24, 1987 (Abandoned).
FIELD OF INVENTION
This invention related to periodic, non-periodic, random arid irregular building configurations composed of a plurality of non-regular nodes coupled by struts. The nodes are defined by classes of non-regular polyhedra which determine the number and angles of directions of struts by lines joining their center to their vertices, edges and faces. The building system can be combined with panels, tensile and membranes systems, or can be converted into plate systems. The spaces and configurations defined by the building system include layered and non-layered configurations, polyhedral packings and space-fillings, infinite polyhedra, and various n-dimensional polytopes for architectural environments.
BACKGROUND OF THE INVENTION
Building systems composed of industrialized manufactured parts ususlaly rely upon well-known geometries where the shapes of the components are designed according to the geometry dictated by the underlying spatial grids. Such underlying grids have usually been periodic in nature, though some recent proposals have included non-periodic geometries. Examples of such building systems include: Fuller's octet truss composed of regular octahedra and tetrahedra and already anticipated by Alexander Graham Bell, Pearce's Mini-max system based on the twenty-six strut directions determined by the thirteen symmetry axes of a regular cube, NASA's node for the Space Station, also based on the twenty-six directions of the regular cube, the Mero system based on the eighteen directions of the regular cube, Baer's 31-zome system based on the thirty-one axes of symmetry of the regular icosahedron, and Lalvani's systems based on the various directions of the infinite classes of regular prisms.
Numerous patents have been cited in this field and include: U.S. Pat. No. 1,113,371 to Pajeau; U.S. Pat. No. 1,960,328 to Breines; U.S. Pat. No. 2,909,867 to Hobson; U.S. Pat. No. 2,936,530 to Bowen; U.S. Pat. No. 3,563,581 to Sommerstein, U.S. Pat. No. 3,600,825 to Pearce; U.S. Pat. No. 3,632,147 to Finger; U.S. Pat. No. 3,722,153 to Baer; U.S. Pat. No. 3,733,762 to Pardo; U.S. Pat. No. 3,918,233 to Simpson; U.S. Pat. No. 4,113,256 to Hutchings; U.S. Pat. No. 4,129,975 to Gabriel, U.S. Pat. No. 4,133,152 to Penrose; U.S. Pat. No. 4,183,190 to Bance; U.S. Pat. No. 4,295,307 to Jensen; U.S. Pat. No. 4,620,998 to Lalvani; U.S. Pat. No. 4,679,961 to Stewart; U.S. Pat. No 4,723,382 to Lalvani; U.S. Pat. No. 5,007,220 to Lalvani and U.S. Pat. No. 5,036,635 to Lalvani. Related foreign patents include U.K. patents 1,283,025 to Furnell and 2,159,229A to Paton; West German patent 2,305,330 to A. Cilveti and 2,461,203 to Aulbur; French patents 682,854 to Doornbos et al and 1,391,973 to Stora; and Italian patent 581,277 to Industria Officine Magliana. The disclosure of these patents are hereby incorporated herein by reference.
All modular periodic and non-periodic building space frame systems in prior art are based on regular (Platonic), semi-regular (Archimedean) polyhedra and regular prisms. These restrictions though necessary from certain formal aspects of symmetry and modularity, are limiting for an architect from the point of view of flexibility in designing irregular, one-of-a-kind compositions for individual projects and clients. Compared with systems based on regular polyhedra, where at most three different lengths of struts are used, non-regular modular building systems, like the ones disclosed herein, use a greater variety of lengths and regular or arbitrary angles. There are no building systems based on nodes derived from non-regular polyhedra in prior art. The co-pending application 07/740,504 deals with non-regular polyhedra derived from various vector-stars, wherein the vector-stars are used as a geometric generators but not as physical building elements. In the present disclosure, the vector-stars are used as physical nodes of a building system.
The use of non-regular nodes, as described herein, permits a greater flexibility in design and architectural layout by allowing the possibility of making a variety of periodic configurations, a variety of non-periodic configurations, and a variety of arbitrary and random configurations from fixed number of building parts. Such a flexibility is greatly desirable for an architect, since the same system can allow each architect to develop his or her own designs in an endless variety of ways. In addition, non-regular space frame nodes permit a modular randomness which is a desirable goal in architectural design. The "modular" aspect is neccessary for economy in technological production, manufacture and assembly in both traditional and computer-aided design and manufacturing environments. The "randomness" aspect in design is important since it permits the designer to break the order locally and globally within a system and produce irregular compositions.
The search for novelty in design leads the designer to look for new ways to configure and structure spaces within architectural contexts. Building systems based on non-regular polyhedral nodes expand the architectural vocabulary by providing structures with irregular angles, lengths and faces. Such structures, while retaining the property of permitting periodic configurations, permit non-periodic configurations, and further permit irregular-random configurations out of a limited number of building components, thereby advancing the building art.
SUMMARY OF THE INVENTION
Accordingly, the primary object of the invention is to provide a family of building systems comprsing space frames based on classes of non-regular polyhedral nodes connected by appropriate struts, where the space frames can be converted into panel or plate systems, nodeless space frames, membrane and shell systems, tensile and tensegrity systems, and various architectural design and construction kits.
Another object of the invention is to permit the design of a variety of periodic, non-periodic and irregular random-looking spatial configurations from a limited set of component parts.
Another object of the invention is to permit the construction of a variety of non-regular building systems which are topologically identical to the building currently in use (like the Pearce's 13-directional cubic node system, and Baer's 31-directional icosahedral node system) but are geometrically different.
Another object of the invention is to permit the construction of a variety of 3-dimensional projection of n-dimensional polytopes including the hyper-cube, hyper-cubic lattices, and various 4-dimensional polytopes.
The foregoing objects are basically achieved by providing a class of building space frame systems derived from the number and angles of directions specified by several classes of non-regular polyhedra. These classes of non-regular polyhedra include the following:
a. hexahedra, parallelopipeds and rhombohedra,
b. infinite class of upright and tilted p-sided non-regular prisms with unequal sides and uneqaul angles where p is greater than 2,
c. non-regular tetrahedra,
d. non-regular octahedra,
e. non-regular icosahedra,
f. non-regular dodecahedra,
g. any non-regular variant of the thirteen Archimedean semi-regular polyhedra or their duals, and
h. any arbitrary convex or non-convex polyhedron.
From this class of non-regular polyhedra, lines joining the vertices, any points on the edges, any points of the faces, prescribe the directions of the struts for the space frames. The angles between these directions prescribe the face angles of the non-regular polygons comprising the derived polyhedra. The lengths of these lines determine the lengths of the struts or edges of the derived polyhedra.
Other objects, advantages and salient features of the invention would become clearer from the following detailed description, which, taken in conjunction with the annexed drawings, discloses preferred embodiments of the present invention.
DRAWINGS
Referring to the drawings which form a part of this original disclosure:
FIG. 1 shows various types of non-regular hexahedra including parallelopipeds and rhombohedra and their associated node-stars. THis includes a 26-strut (13-directional) node-star for a space frame system is also shown.
FIG. 2 shows a unit portion of a space frame based on the 26-strut (13-directional) node-star obtained from a rhombohedron. Various derivative units for space frames are also shown.
FIG. 3 shows portions of non-periodic space frame arrangements using the the concepts space frames units derived in FIG. 2.
FIG. 4 shows non-regular tetrahedra and a derivative 14-strut (7-directional) node-star.
FIG. 5 shows non-regular octahedra and and associated sub node-star with six strut directions.
FIG. 6 shows on example of a non-regular icosahedron as a basis for a 62-strut (31-directional) space frame system. An associated node-star with 12-struts is shown.
FIG. 7 shows a non-regular dodecahedron which can be used as a basis for another non-regular 31-directional space frame system.
FIG. 8 shows a non-regular inclined pyramid as a basis another non-regular space frame building system. A derivative 6-directional node-star is shown alongside.
FIG. 9 shows non-regular prisms as generators of node-stars. An example of a 26-strut (13-directional) node-star, based on a hexagonal prism, is shown as a basis for another non-regular space frame building system. Additional sub node-stars with 6 directions are also shown.
FIG. 10 shows two examples of non-regular versions of Archimedean polyhedra as generators of non-regular space frame building systems. Examples include 12-strut (6-directional) and 24-strut (12-directional) node-stars derived from a cuboctahedron and truncated octahedron, respectively.
DETAILED DESCRIPTION OF THE INVENTION
This invention is based on the use of nodes, or node-stars, derived by joining the center of various non-regular polyhedra to its faces, edges and vertices. A variety of non-regular polyhedra, which can be seen as geometric variants of the known regular and semi-regular polyhedra, are described along with the derivation of associated node-stars. Node-stars, as used herein, is a term used for the configuration of struts attached to and radiating from a central node. The definition of "nodes" herein is meant to imply a physical node in a space frame, or a node-complex derived from the star-geometry of the nodes. The node-complex may also include a "nodeless" system, where no physical node is present, but where the directions of the struts are determined by the directions specfied by the node-star.
Regular polyhedra, also termed "Platonic solids" and well-known in the literature, are defined as polyhedra composed of regular polygons having equal face angles and equal edge lengths, where the regular polyhedra meeting identically at every vertex. There are five such polyhedra which include the tetrahedron composed of four equilateral triangles with three triangles meeting at every vertex, octahedron composed of eight equilateral triangles with four triangles meeting at every vertex, cube composed of six squares with three squares meeting at every vertex, icosahedron composed of twenty equilateral triangles with five triangles meeting at every vertex and the dodecahedron composed of twelve regular pentagons with three pentagons meeting at every vertex.
Non-regular polyhedra are here defined as polyhedra composed of non-regular polygonal faces. Non-regular polygons have at least two different face angles, and may have equal or unequal edges. This includes the odd-sided plane polygons and the infinite class of even-sided plane polygons called zonogons. In addition, non-regular polygons may be convex where all face angles are less than 180°, or concave where at least one angle is greater than 180°. Non-regular polygons may also be planar or non-planar, like saddle-shaped polygons.
Non-regular polyhedra composed of only triangles, as in the case of non-regular tetrahedra, octahedra and icosahedra, have at least two different edge lengths. However, in these three cases, the faces remain planar. The non-regular tetrahedra are always convex, while the non-regular octahedra and icosahedra can be convex or concave.
Non-regular variant of a cube includes the general class of hexahedra composed of six planar or non-planar quadrilaterals. Restricting to planar faces, the general class of parallelopipeds is composed of three pairs of parallelograms and three sets of unequal edges. When the three sets of edges are equal, the parallelopipeds are rhombohedra. When two sets of edges are equal, the parallelopipeds are upright or tilted rhombic prisms. The faces of various parallelopipeds are composed of squares, rectangles, rhombii and parallelograms.
Non-regular pentagonal dodecahedra are compsed of non-regular pentagons. When the pentagons are planar, at least two different edges are necessary. When the pentagons are non-planar, all its edges may be equal or unequal.
Other classes of well-known regular-faced polyhedra include the thirteen semi-regular Archimedean polyhedra composed of more than one type of regular polygon. Here too, the polygons meet alike at all the vertices. Non-regular variants of Archimedean polyhedra include polyhedra composed of the same number of faces and meeting alike in the same manner at the vertices, as in the case of Archimedean polyhedra, but here the faces are non-regular polygons.
One more class of regular-faced polyhedra includes the infinite class of prisms. The non-regular counterparts are composed of non-regular top and bottom faces connected by square, rectangular or parallelogram faces. Other non-regular variants of prisms include saddle prisms with a saddle top and bottom. Non-regular pyramids can be seen as derivatives of prisms, or a separate class by themselves.
All the above-mentioned non-regular polyhedra are used as a basis for the derivation of nodes for space frames. The polyhedra are converted into node-stars by joining their centers to various positions on the surface of the polyhedra. In practice, the precise geometry of the non-regular polyhedra, with appropriate edge-lengths and face angles must be specified. From these the directions of struts radiating from the center can be easily calculated by trignometry. Other examples of non-regular node-stars are derived from arbitrary convex or non-convex polyhedra and vector-stars. The vector stars are usually used as a geometric device to generate zonohedra, n-dimensional cubes, and space-fillings of rhombohedra and zonohedra. Here these stars are used as a physical node for architectural space frames.
FIG. 1 shows a variety of hexahedra including various rhomohedra and parallelopipeds and the derivation of node-stars from such a family of non-regular polyhedra. Illustrations 1-4 show the top plan view of four upright prisms: square prism 1 composed of faces 17, a rhombic prism 2 with a top face 18, a rectangular prism 3 with a top face 19, and a parallelopiped 4 with a parallelogram face 20 on top and bottom. In the four cases, the vertex-locations are marked V1-4, the points on the edges are marked E1-4, and the points on the faces are marked F1-4. These are the points on the surface of the parallelopiped which will be joined to the center to derive a node-star. Miscellaneous other examples of parallelopipeds are shown. The rhombohedron 5 is composed of a top square face 21 and two equal rhombic faces 22, the rhombohedron 6 is composed of top square face 21 and two different rhombic faces 23 and 24, a rhombohedron 7 is composed of three equal rhombic faces 25, and the rhombohedron 8 is composed of two different rhombic faces 25 and 26.
The hexahedron 9 is composed of six saddle quadrilaterals with the vertex points marked V5, the edge points marked E5 and the face points marked F5. The rhombohedron 10 is similarly marked with its vertex points V6, edge points E6 and face points F6, and is composed of three different faces 27, 28 and 29. Parallelopipeds 11 and 12 have unequal edges and its surface points are similarly shown by black dots.
The node-star 14 is based on the rhombohedron 10. It has all the directions of struts 13 shown emanating from the node 30 in its center. There are eight struts joining the central node to the vertices V6, six struts joining to the face points F6 and twelve struts joining to the edge points E6. This makes a total of twenty-six struts emanating from the node. Note that this node has the same number of directions as the full cubic-symmetry node used by Pearce, and will permit topologically identical to but geometrically different from the configurations derived from the Pearce node.
The node-star 15 is a sub-set of the node-star 14 and is composed of only four struts 13 joining the central node to the vertex points V6. In the node-star 16, a combination of vertex-, edge- and face- points are joined by struts 13 to the central node 30 to suggest the possibility of using a sub-set of the full node-star 14.
In FIG. 2, the entire rhombohedral space frame complex 31 is completed by joining the outer points, now replaced by additional nodes 30, by adding new struts 13' on the periphery. This illustrates the concept of repeating the node in a space frame. Various decompositions of the space frame complex 31 are shown in 32-36. In frame 31, the points V6, now replaced by node 30, are joined to one another by struts 13'. In frame 32, points F6 to E6 are joined by struts 13'. In frame 33, points F6 are joined to points V6 by struts 13'. In frame 34, face points F6 are joined to the center node 30 by struts 13, in frame 35, the vertex points V6 are joined to node 30, and in frame 36, the edge points E6 are joined to the center.
The frames 32-36 can now be used as sub-assembly units to generate larger periodic, non-periodic or random configurations. This is shown in FIG. 3 with a portion of a non-periodic space-filling composed of rhombohedra. In the space frame 37, the unit sub-assembly 32 is applied to adjacent rhombohedra as shown with the units 32' and 32". Similarly, the space frame 38 is composed of units 33' and 33" corresponding to the unit 33 in FIG. 2, space frames 40, 41 and 42 correspond to the units 35, 36 and 34, respectively. The space frame 39 corresponds to the unit 15 in FIG. 1, and space frame 43 is obtained by joining alternate vertices of a rhombohedron or a parallelopiped.
FIG. 4 shows non-regular tetrahedra 44, 45 and 46 with their vertex points marked V7, V8 and V9, respectively, their edge points marked E7, E8 and E9, respectively, and their face points marked F7, F8 and F9, respectively. The tetrahedron 44 is composed of three isoceles triangles 50 and one equilateral triangle 51. The tetrahedron 45 has two pairs of isoceles triangular faces 52 and 53. The tetrahedron 46 is composed of four asymmetric faces. The node-star 47 is based on the non-regular tetrahedron 44 and is obtained by joining the vertex-, edge- and face-points V7, E7 and F7 to the nodal center 49 using struts 48.
FIG. 5 shows non-regular octahedra. The octahedron 55 composed of asymmetric triangular faces, is shown with all its vertex points, edge-points and face points marked as V10, E10 and F10, respectively. The node-star 55 is derived from 54 by joining the central node 61 to the six vertex points V10 with struts 56. The non-regular octahedra 57 through 60 show other types of octahedra. In 57, the three-fold axis of symmetry is retained; faces 62 on top and bottom are equilateral triangles, and the remaining six faces joining these two are isoceles triangles. The octahedron 58 is composed of four different faces 64-67, the octahedron 59 is composed of asymmetric triangles, and the octahedron 60 is an elongated version of 57 and composed of faces 62 and 63', where 63' is an isoceles triangle analogous to 63. In all four cases, the vertex-, edge- and face-points are marked. Node-stars can be derived from these by joined the marked points to the center of the respective octahedra.
FIG. 6 shows one example of a non-regular icosahedron 67 composed of twently non-regular triangles meeting five at a vertex, just the way a regular icosahedron does. It be visualized by elongating or tilting the regular icosahedron, and other "deformed" icosahedra can be similarly derived. The vertex-, edge- and face-points are marked V11, E11 and F11, respectively, and some of the points are joined by radial lines 69 to the center 70. The node-star 68 is based on 67 and is shown with radial struts 71 joining the central node 70' to the twelve vertex-points V11. Note that the non-regular icosahedron 67 generates 62 radial lines which are analogous to the 31-zone system of Baer, but here the geometry (i.e. lengths and angles) are different though the topology (connectedness) is the same. The full node-star 67 will generate configurations which are topologically identical to all configurations which can be generated from the Baer system, but the precise geometry of these new space frame configurations will be differ in lengths and angles.
FIG. 7 shows an elongated pentagonal dodecahedron 72, topologically identicakl to the regular dodecahedron, but there the ten of the twelve faces are non-regular. The twelve face-points, the twenty vertex-points and the thirty edge-points are marked. Joining these points to the center provides a 62-directional node. This gives another non-regular variation of the 31-zone system of Baer and can similarly be used to build space frame configurations analogous to those possible from regular dodecahedral nodes. The implications for quasi-crystalline non-periodic architectural configurations are obvious by analogy.
FIG. 8 shows a non-regular inclined pentagonal pyramid 73 proposed of vertex-points V12, edge-points E12 and face-points F12. A special type of 6-directional non-regular node-star 74 is derived from 73 by joining the bottom pentagonal face-point F12 to the six vertex-points V12. This node can be used to construct periodic and non-periodic layered configurations.
FIG. 9 shows various non-regular prisms and derivative node-stars. The hexagonal prism 75 is composed of non-regular hexagonal top and bottom faces 92 connected by square faces 93. In 76, the prism 75 is shown with its vertex-points V13, edge-points E13 and face-points F13. The top plan view 77 shows the hexagon 92 with its true angles which depart from the 120° of a regular hexagon, though it still retains a mirror symmetry. The hexagon 79 is a variant, shown with points marked; note that the edge-points E14 are not marked at mid-points and the face point F14 is also no in the middle. The face point F15 suggests the possibility of locating two points on the face of a polyehdron. The hexagon 80 has two different edge-lengths. It has lost the mirror-plane but has retained the 2-fold symmetry. The hexagon 81 has lost complete symmetry, and has unequal angles and edges.
The node-star 82 is based on the prism 75 and the radial struts 93 join the node 97 placed at the center to the points V13, E13 and F13 already identified earlier in 76. The node-star 83 is a subset of 82 and joins the central node 97 to the vertices V13 with struts 93, The node-star 84 joins the center 97 to a combination of vertex-, edge- and face-points with struts 93. The node-star 85 is based on a saddle hexagonal prism and is shown with lines 95 joining the center 96 to the vertices V15.
Illustrations 86 through 91 show three different non-regular prisms 86, 88 and 90. The triangular prism 86 has the top and bottom faces composed of asymmetric right-angled triangles 87, the pentagonal prism 88 is composed of top and bottom non-regular pentagons 89 with unequal face angles and edges, the octagonal prism 90 is composed of top and bottom octagons 91 having equal edges and unequal angles. In the three cases, the vertex-, edge- and face-points are marked to show possible directions of struts radiating from a node placed at the center.
FIG. 10 shows two examples of non-regular analogs of the semi-regular Archimedean polyhedra. Other examples can be similarly derived. The elongated cuboctahedron 98 is shown with its vertex-, edge- and face-points marked as V16, E16 and F16, respectively. The cuboctahedron 99 is asymmetric. The node-star 100 is derived from 98 and is obtained by joining the center to the twelve vertex-points V16. It is shown with the twelve struts 104 radiating from the center 105. Additional strut directions are possible from the edge-points and face-points. The elongated truncated octahedron 101 has a three-fold axis of symmetry along its vertical axis. Its vertex-, edge- and face-points are marked as V17, E17 and F17, respectively. 102 is an asymmetric variant, also shown with its various points on the surface marked. The node-star 103 is based on 101 and is obtained by joining the struts 106 to the central node 107. The struts radiate to the vertex-points V17, and additional strut directions can be similarly added.
Various non-regular polyhedra have been shown and a technique for deriving node-stars has been shown. The the node-stars are an assembly of a single node at the center from which numerous struts radiate. Suitable mechanical and other attachments, coupling devices, fasteners, interlocking mechanisms, screws, pins, etc. can be used to secure the connection between the node and struts. The nodes can be suitably designed as spheres, ellipsoids, non-regular polyhedra, etc. The nodes can be cast in one or more pieces, can be solid or hollow, can be manufactured in parts and assembled. The struts could be solid, hollow, have a polygonal section or be tapered.
The same nodes can produce an infinite variety of configurations, and can be assembled or disassembled into other configurations. The same nodes, coupled with struts can produce periodic, non-periodic and irregular or random arrangements. The non-periodic arrangements could be rule-based, oor procedure-based, whereby a construction procedure enables the systematic generation of the non-periodic configuration. The configurations could be single-layered as in screens, double-layered as in roofs, triple or multi-layered as in 3-dimensional space frames for habitats. The configurations could also be multi-directional, without any layers.
The non-regular space frame systems described herein can be used to generate a large variety of space configurations. Besides the various non-regular polyhedra, zonohedra, space-fillings of parallelopipeds, rhombohedra and zonohedra are possible. n-dimensional space frames are also possible. Of particular interest are hyper-cubes or n-dimensional cubes, hyper-cubic or n-dimensional cubic lattices, various 4-dimensional and n-dimensional polytopes, where n is any number greater than three. The space frames could be stabilized with triangulation, cables or membranes.
The node-stars could be converted into "nodeless" space frame systems where the struts radiate in the same manner from the node center, but bypass the center or connect to adjacent struts. The node-star concept can be easily converted into a building system using the structural plate concept by inserting plates in the polygonal areas defined by the struts. In pure plate action configurations, the struts can be removed and the plates attached to one another.
The full node-stars could be used, or only sub-stars could be used as less complex nodes for simpler construction kits. Infinite variants of each non-regular polyhedron could be used to derive new classes of nodes. This way the inventory of building systems can be continually updated with newer configurations.
While only selected examples and features of the invention have been described, numerous variations can be developed without departing from the scope of the invention.
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A family of space frame systems composed of a plurality of nodes coupled by struts and derived from a family of non-regular polyhedra by joining the center of these polyhedra to their faces, edges and vertices. The space frames permit periodic, non-periodic, random and irregular building configurations. The building system can be combined with panels, tensile and membranes systems, or can be converted into plate systems or nodeless space frame systems. The spaces and configurations defined by the building system include single-layered, double-layered, multi-layered configurations, non-layered and multi-directional configurations, polyhedral packings and space-fillings, infinite polyhedra, and various 3-dimensional projections of n-dimensional polytopes for architectural environments. The n-dimensional polytopes include the infinite classes of hyper-cubes and hyper-cubic lattices, and a variety of 4-dimensional polytopes.
Applications include architecture on earth and in space, environmental and sculptural structures, platforms, roofs and playground structures, honeycombs, toys, games and educational kits.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present disclosure relates generally to computer networks. More particularly, the present disclosure relates to clusters of interconnected computer systems.
[0003] 2. Description of the Background Art
[0004] A cluster is a parallel or distributed system that comprises a collection of interconnected computer systems or servers that is used as a single, unified computing unit. Members of a cluster are referred to as nodes or systems. The cluster service is the collection of software on each node that manages cluster-related activity. The cluster service sees all resources as identical objects. Resource may include physical hardware devices, such as disk drives and network cards, or logical items, such as logical disk volumes, TCP/IP addresses, entire applications and databases, among other examples. A group is a collection of resources to be managed as a single unit. Generally, a group contains all of the components that are necessary for running a specific application and allowing a user to connect to the service provided by the application. Operations performed on a group typically affect all resources contained within that group. By coupling two or more servers together, clustering increases the system availability, performance, and capacity for network systems and applications.
[0005] Clustering may be used for parallel processing or parallel computing to simultaneously use two or more CPUs to execute an application or program. Clustering is a popular strategy for implementing parallel processing applications because it allows system administrators to leverage already existing computers and workstations. Because it is difficult to predict the number of requests that will be issued to a networked server, clustering is also useful for load balancing to distribute processing and communications activity evenly across a network system so that no single server is overwhelmed. If one server is running the risk of being swamped, requests may be forwarded to another clustered server with greater capacity. For example, busy Web sites may employ two or more clustered Web servers in order to employ a load balancing scheme. Clustering also provides for increased scalability by allowing new components to be added as the system load increases. In addition, clustering simplifies the management of groups of systems and their applications by allowing the system administrator to manage an entire group as a single system. Clustering may also be used to increase the fault tolerance of a network system. If one server suffers an unexpected software or hardware failure, another clustered server may assume the operations of the failed server. Thus, if any hardware of software component in the system fails, the user might experience a performance penalty, but will not lose access to the service.
[0006] Current cluster services include Microsoft Cluster Server (MSCS), designed by Microsoft Corporation for clustering for its Windows NT 4.0 and Windows 2000 Advanced Server operating systems, and Novell Netware Cluster Services (NWCS), among other examples. For instance, MSCS supports the clustering of two NT servers to provide a single highly available server.
[0007] Clustering may also be implemented in computer networks utilizing storage area networks (SAN) and similar networking environments. SAN networks allow storage systems to be shared among multiple clusters and/or servers. The storage devices in a SAN may be structured, for example, in a RAID configuration.
[0008] In order to detect system failures, clustered nodes may use a heartbeat mechanism to monitor the health of each other. A heartbeat is a signal that is sent by one clustered node to another clustered node. Heartbeat signals are typically sent over an Ethernet or similar network, where the network is also utilized for other purposes.
[0009] Failure of a node is detected when an expected heartbeat signal is not received from the node. In the event of failure of a node, the clustering software may, for example, transfer the entire resource group of the failed node to another node. A client application affected by the failure may detect the failure in the session and reconnect in the same manner as the original connection.
[0010] If a heartbeat signal is received from a node of the cluster, then that node is normally defined to be in an “up” state. In the up state, the node is presumed to be operating properly. On the other hand, if the heartbeat signal is no longer received from a node, then that node is normally defined to be in a “down” state. In the down state, the node is presumed to have failed.
SUMMARY
[0011] One embodiment disclosed herein pertains to a method of communicating status from a node of a cluster of computer systems. A first status signal is received from a computational node, and a default status signal is generated. The first status signal and the default status signal are used to generate a second status signal.
[0012] Another embodiment disclosed herein pertains to a method of communicating node status within a cluster of computer systems. A first signal indicative of the status of a current node is generated. A second signal indicative of the status of a preceding node is received. The first signal is transmitted to a next node if the current node is present in the cluster, and the second signal is transmitted to the next node if the current node has been removed from the cluster.
[0013] Another embodiment disclosed herein pertains to an apparatus for communicating status from a node of a cluster of computer systems. The apparatus includes at least an input, a default signal generator, and an output signal generator. The input is configured to receive a first status signal from a computational node, and the default signal generator is configured to produce a default status signal. The output signal generator is configured to use the first status signal and the default status signal to produce a second status signal.
[0014] Another embodiment disclosed herein pertains to an apparatus for communicating node status within a cluster of computer systems. Circuitry is configured to generate a first signal indicative of the status of a current node, and an input is configured to receive a second signal indicative of the status of a preceding node. A choosing circuit is configured to transmit the first signal to a next node if the current node is present in the cluster and to transmit the second signal to the next node if the current node has been removed from the cluster.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a schematic diagram depicting a node of a cluster in accordance with an embodiment of the invention.
[0016] FIG. 2 is a schematic diagram of the signaling hardware in accordance with an embodiment of the invention.
[0017] FIG. 3 is a schematic diagram of the output signal generator in accordance with an embodiment of the invention.
[0018] FIG. 4 depicts timing diagrams of the subsystem status signal and default BAD signal in accordance with an embodiment of the invention.
[0019] FIG. 5 depicts timing diagrams of the node status signal in accordance with an embodiment of the invention.
[0020] FIG. 6 is a schematic diagram of a status pass-through circuit in accordance with an embodiment of the invention.
[0021] FIG. 7 is a schematic diagram of a node of a cluster in accordance with another embodiment of the invention.
[0022] FIG. 8 is a schematic diagram of a status pass-through circuit in accordance with another embodiment of the invention.
DETAILED DESCRIPTION
[0023] The conventional technique for reporting a state of a clustered node is described above. In the conventional technique, a heartbeat mechanism is used, and the node determined to be in either an “up” or a “down” state.
[0024] This conventional technique is insufficient and disadvantageous in various cases. For example, even if a target critical application is not functioning (i.e. the application is down), the node on which the application is running may still be transmitting its heartbeat signals. In that case, the cluster would still consider the node to be up, even though the critical application is down. In another example, the cluster may not receive an expected heartbeat signal from a node and so assume that the node is down. However, that node may actually be up (i.e. operating properly), and the missed heartbeat signal may instead be due to a failed interconnect.
[0025] Furthermore, the conventional technique typically utilizes existing circuitry to generate and transmit the status signals. This existing circuitry is also used for other communications within the cluster. In contrast, applicants have determined that using dedicated circuitry specifically designed to robustly generate and transmit status signals is advantageous over the conventional technique.
[0026] It turns out that the efficiency (percentage uptime) of a high-availability (HA) cluster is largely determined by the amount of time the cluster takes to recognize that one of its nodes has ceased performing useful computing or storage functions (i.e. when the node is effectively down). Once the cluster has determined that the node is effectively down, the clustering software can perform the necessary tasks to keep the rest of the nodes running with little interruption to user tasks.
[0027] However, as discussed above, the conventional technique used to determine the state of a cluster node is inaccurate in various cases. The conventional technique may result in either false (unnecessary) failovers, or in failed detects. Failed detects are where the cluster level software fails to switchover from a bad node to a good node when it should. Furthermore, the conventional technique often takes an undesirably long time to detect a down state of a node.
[0028] FIG. 1 is a schematic diagram of a node 100 of a cluster in accordance with an embodiment of the invention. The node 100 includes a conventional computational subsystem 102 and signaling hardware circuitry 106 . The computational subsystem 102 comprise computational elements, typically including one or more central processing units (CPUs), memory, and so on). The computational subsystem 102 generates and outputs, among other signals, a subsystem status signal 104 . The signaling hardware circuitry 106 receives the subsystem status signal 104 and outputs a node status signal 108 . The node status signal 108 may be output to a next node in the cluster. These signals are described further below in relation to the subsequent figures.
[0029] FIG. 2 is a schematic diagram of the signaling hardware 106 in accordance with an embodiment of the invention. The signaling hardware 106 may include a signal generator 202 and an output signal generator 206 .
[0030] The signaling hardware 106 receives the subsystem status signal 104 from the computational node 102 . Exemplary timing diagrams for the subsystem status signal 104 is shown at the top portion of FIG. 4 . As depicted in FIG. 4 , the subsystem status signal 104 may be in a GOOD (up) state or a BAD (down) state. For instance, the GOOD state may be represented by a high (logical 1 ) signal, and the BAD state may be represented by a low (logical 0 ) signal. If the computational subsystem 102 is functioning properly (working correctly), then the subsystem status signal 104 should be driven to the GOOD state. If the computational subsystem 102 is not functioning properly, then no GOOD state should be driven onto the subsystem status signal 104 . A lack of a GOOD signal means that the system is BAD (down).
[0031] The signal generator 202 produces a default BAD (default down) signal 204 . An exemplary timing diagram for the default BAD signal 204 is shown at the bottom portion of FIG. 4 . As depicted in FIG. 4 , the default BAD signal 204 comprises an asymmetrical periodic signal (not just a logical level). For instance, as illustrated, the default BAD signal 204 may comprise an asymmetrical toggling pattern or pulse-modulated signal. The toggling pattern shown in FIG. 4 is just an example showing one possibility. Such a toggling pattern may be generated using various electronic circuitry that is known to those of skill in the art.
[0032] The output signal generator 206 is configured to receive both the default BAD signal 204 and the subsystem status signal 104 . The output signal generator 206 uses these two signals to generate and output the node status signal 108 .
[0033] FIG. 3 is a schematic diagram of the output signal generator 206 in accordance with an embodiment of the invention. The output signal generator 206 may include a pull-down element 302 and a logical function block 304 .
[0034] As shown in FIG. 3 , the pull-down element 302 is coupled to the line receiving the subsystem status signal 104 . When a high level (GOOD in this embodiment) is not driven from the computational subsystem 102 , then the pull-down element 302 forces a low level (BAD in this embodiment) onto the line. Hence, the subsystem status signal 104 is advantageously pulled to a level corresponding to a BAD state even if the computational subsystem 102 does not produce any signal.
[0035] In an alternate implementation, the low level for the subsystem status signal 104 may correspond to a GOOD state, and the high level may correspond to a BAD state. In that case, a pull-up element may be used to achieve this advantageous effect. Pull-down and pull-up circuit elements (voltage-level pulling elements) are known to those of skill in the pertinent art.
[0036] As depicted in FIG. 3 , the logical function block 304 receives the default. BAD signal 204 along with the subsystem status signal 104 . In accordance with one embodiment, the logical function block 304 may comprise an exclusive-or (XOR) gate. In other embodiments, different functions may be utilized.
[0037] Exemplary timing diagrams of the node status signal 108 produced by the logical function block 304 are shown in FIG. 5 . For these timing diagrams, the logical function block 304 is an XOR gate, and the signals input into the XOR gate are the signals ( 104 and 204 ) depicted in FIG. 4 .
[0038] First, consider the node status signal 108 produced when the subsystem status signal 104 corresponds to a BAD state. In this case, the XOR gate receives the default BAD signal 204 and a low level for the subsystem status signal 104 , and performs an exclusive-or operation on these two signals. The result is the node status signal 108 shown at the upper part of FIG. 5 . In this instance, the node status signal 108 is a periodic signal representing a BAD state. More specifically, here, the node status signal 108 is of the same periodic form (toggling or pulse-modulated pattern, in this instance) as the default BAD signal 204 .
[0039] Next, consider the node status signal 108 produced when the subsystem status signal 104 corresponds to a GOOD state. In this case, the XOR gate receives the default BAD signal 204 and a high level for the subsystem status signal 104 , and performs an exclusive-or operation on these two signals. The result is the node status signal 108 shown at the lower part of FIG. 5 . In this instance, the node status signal 108 is a periodic signal representing a GOOD state. More specifically, here, the node status signal 108 is a different periodic signal which is a complement of the default BAD signal 204 .
[0040] FIG. 6 is a schematic diagram of a status pass-through circuit 600 in accordance with an embodiment of the invention. This circuit 600 advantageously allows a node status signal 108 for a preceding node to pass through a current node if the current node is down.
[0041] The signaling hardware 106 for node N produces the node status signal 108 for node N. For example, the signaling hardware 106 and node status signals 108 may be as described above in relation to the preceding figures.
[0042] A choosing circuit 602 receives the node status signal 108 for node N. In addition, the node status signal 108 from node N−1 (another node in the cluster) is received by the choosing circuit 602 . The choosing circuit 602 operates on the two signals and produces a status out signal 604 that is transmitted to node N+1 (the next node in the cluster). In one embodiment the choosing circuit 602 may comprise a multiplexer (MUX) that selects one of the two status signals to pass on (via the status out signal 604 ) to the next node. If the computational subsystem (computational element) of node N has previously been removed from the cluster (for example, due to node failure, maintenance, or other reasons), then the status from node N−1 is passed. If the computational subsystem of node N is presently in use by the cluster, then the status of node N is passed. In this way, even if node N is down, the status of node N−1 is advantageously still evaluated by the system.
[0043] Note that if node N−1 is down, then the status signal received from node N−1 may originate from node N−2. If nodes N−1 and N−2 are both down, then the status signal received from node N−1 may originate from node N−3. And so on.
[0044] FIG. 7 is a schematic diagram of a node 700 of a cluster in accordance with another embodiment of the invention. The node 700 in FIG. 7 is similar to the node 100 in FIG. 1 . However, here, the node 700 generates a subsystem degraded status signal 702 in addition to the conventional subsystem status signal 104 . In combination with the conventional subsystem status signal 104 , the subsystem degraded status signal 702 expands the reported state from a simple binary signal to a multi-state (three-state or more) signal.
[0045] For example, the subsystem degraded status signal 702 may indicate a DEGRADED state or NOT_DEGRADED state for the computational subsystem 102 . A DEGRADED state may be defined as when one or more aspects of the node is not running “up to par,” so that the node may possibly be removed from the HA cluster. For example, the following rules may be used.
Rule D1: Computational subsystem loses greater than 50% performance Rule D2: Severe (one level below critical) chassis code received
Variations of these rules and additional rules may also be used to define a DEGRADED state depending on the specific system. For example, the percentage performance prior to a degraded state being entered may differ from 50%. It may be higher, such as 75%, or lower, such as 25%.
[0048] In one embodiment, the subsystem degraded status signal 702 may be a simple flag indicating that the node is either degraded or not. In other embodiments, there may be multiple levels of degradation. These multiple levels of degradation may be implemented using multi-bit encoding of the level of degradation. In other words, instead of having just a single DEGRADED state, multiple levels of degradation may be defined by the rules. Using multiple levels of degradation would advantageously provide the HA clustering software with additional information for its decision making process as to how to manage the nodes of the cluster. For example, the degradation level may depend on the percentage performance lost.
[0049] In one specific embodiment, the node degraded status signal 704 may comprise a set of lines that provide the degraded state digitally to the next node in the HA cluster. These lines may be pulled down with resistors. One implementation may be as follows. All logical zeroes on these digital lines may indicate the node is BAD. All logical ones on these lines may indicate the node is GOOD. Other values in between may indicate the degradation level of the node, with the higher values indicating greater functioning.
[0050] FIG. 8 is a schematic diagram of a status pass-through circuit 800 in accordance with another embodiment of the invention. The circuit 800 in FIG. 8 is similar to the circuit 600 in FIG. 6 . However, here, the choosing circuit 802 also receives the node degraded status signal 704 from nodes N and N−1.
[0051] The choosing circuit 802 operates on the input signals and produces a status out signal 804 including the additional degraded status information along with the GOOD/BAD status information from either node N or node N−1. Advantageously, this degraded status information may be utilized by the cluster level software as a “check” against the GOOD/BAD status information, resulting in a more reliable set of status information.
[0052] The above disclosure includes various advantages over the conventional art. First, the dedicated hardware is designed and used for the purpose of reliably transmitting the node status information to the cluster. This should improve the high-availability of the cluster. Second, a GOOD state is only transmitted when the appropriate software on the node is up and running and is able to signal a GOOD state. As a result, the hardware does not indicate a GOOD state when the software is down. Third, the above disclosure provides a solution to the problem of differentiating a “no heartbeat” because a node is down from a “lost heartbeat” due to a failed interconnect. This is done by providing the default BAD signal which may be modified to a GOOD signal by the working node. Fourth, the above disclosure provides a separate output for degraded type status signals, resulting in the reliable communication of such a degraded state. Moreover, the degraded status signal allows the cluster level software to use a “voting scheme” to quickly and accurately determine if a node is really down. For example, the voting scheme may utilize three signals, including the GOOD/BAD signal, the DEGRADED/NOT_DEGRADED signal, and the normal Ethernet connection provided by the cluster.
[0053] In the above description, numerous specific details are given to provide a thorough understanding of embodiments of the invention. However, the above description of illustrated embodiments of the invention is not intended to be exhaustive or to limit the invention to the precise forms disclosed. One skilled in the relevant art will recognize that the invention can be practiced without one or more of the specific details, or with other methods, components, etc. In other instances, well-known structures or operations are not shown or described in detail to avoid obscuring aspects of the invention. While specific embodiments of, and examples for, the invention are described herein for illustrative purposes, various equivalent modifications are possible within the scope of the invention, as those skilled in the relevant art will recognize.
[0054] These modifications can be made to the invention in light of the above detailed description. The terms used in the following claims should not be construed to limit the invention to the specific embodiments disclosed in the specification and the claims. Rather, the scope of the invention is to be determined by the following claims, which are to be construed in accordance with established doctrines of claim interpretation.
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One embodiment disclosed relates to a method of communicating status from a node of a cluster of computer systems. A first status signal is received from a computational node, and a default status signal is generated. The first status signal and the default status signal are used to generate a second status signal. Another embodiment disclosed relates to a method of communicating node status within a cluster of computer systems. A first signal indicative of the status of a current node is generated. A second signal indicative of the status of a preceding node is received. The first signal is transmitted to a next node if the current node is present in the cluster, and the second signal is transmitted to the next node if the current node has been removed from the cluster.
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This is a continuation of application Ser. No. 07,831,045 filed on May 26, 1992, now abandoned which is a divisional of 07/676,944 filed Mar. 28, 1991, now issued as U.S. Pat. No. 5,118,664.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to well drilling fluid additives. More specifically, there is provided a mixture of components which, when added to drilling fluid or circulated through a borehole before casing is placed in the well, is effective in substantially reducing loss of fluid from the borehole.
2. Description of Related Art
The problems of reducing fluid loss from drilling wells have been recognized and addressed for decades. The generic causes of fluid loss from boreholes to the surrounding earth formations are well-known. They include: natural fractures in the rocks drilled, induced fractures when pressure in the drilling fluid exceeds fracturing stress of the earth, cavernous formations, and highly permeable formations. Unfortunately, the cause of fluid loss in drilling a particular well is not always known. Therefore, a variety of responses are often employed in attempts to control loss of fluid from a well. If the cause is believed to be natural or induced fractures or caverns, corrective action may begin by circulating into the well a pill or slug of larger particles at high concentration. This pill may contain a blend of granular, fibrous and flake materials with a particle size distribution believed to be large enough to form a bridge of material in the fracture or cavern. It is important that the bridge be within the formation and not on the surface of the wellbore where it can be dislodged by the drill pipe.
After a bridge is formed, it will still be necessary to form a seal of finer material on the bridge to reduce fluid loss from the wellbore to an acceptable level. If highly permeable formations are open to the wellbore, it is also necessary to form a seal of these formations to decrease fluid loss. Thus, a sealing composition for drilling fluids has a wide range of applicability.
To form a seal over a bridge that has been formed in a fracture or cavern or over a highly permeable formation, it has been found that a matting or caking effect should take place. A gradation of particle sizes, shapes and rigidity is beneficial in forming the seal, and there is an optimum blend to produce maximum fluid loss control with the seal. Obtaining a very effective seal will have the effects of reducing the occurrences of stuck drill pipe, reducing frictional drag between the drill pipe and the borehole wall, aiding in running casing or liners in the well, and possibly improving the quality of logs run in the well.
Both water-based and oil-based fluids are commonly used for drilling. The loss of fluid is usually more costly for oil-based fluids, because the base fluid is more expensive, but loss of fluid can be quite costly with water-based fluids also, because of the chemicals in the fluid.
Chemicals are added to drilling fluids for increased density, viscosity, and gel strength, for lower friction between the drill pipe and the borehole wall and for other purposes. The chemicals added for forming a barrier to flow on the borehole wall or in openings connected to the wall, called lost circulation materials, must be compatible with all the other functions to be performed by the drilling fluid and with all the chemicals added to produce the desired properties of the drilling fluid. In addition, the chemicals are preferably non-toxic and biodegradable.
A variety of naturally-occurring products have been used as lost circulation materials in the past. U.S. Pat. No. 4,619,772 discloses ground durum derived from the outer portion of the endosperm of the durum kernel. This material serves more as a viscosifier than as a fluid loss agent, but actually serves both purposes. U.S. Pat. No. 4,474,665 discloses the use of ground and sized cocoa bean shells, said to be a universal lost circulation controller. This product has not been widely accepted in industry.
The report "Lost Circulation in Geothermal Wells--Survey and Evaluation of Industry Experience," Report No. SAND81-7129, prepared for Sandia National Laboratories in 1981, surveys broad industry experience with lost circulation materials and provides a listing of materials used in the past. The report includes the results of an extensive literature survey. As discussed in the report (Table 3), a variety of wood fibers, cane fibers, organic fibers, nut hulls and seed hulls have been offered for use. Also, graded blends have been available.
Carbon particles are often added to drilling fluids for the purpose of reducing the frictional resistance of the drill pipe in contact with the borehole wall. The carbon particles embed on the cake or mat formed at the wall of the borehole over permeable formations drilled during drilling operations. It is believed that the carbon particles serve as a lubricant in the cake. This lower frictional resistance is very useful in preventing sticking of the drill pipe during drilling, especially where high permeability formations are in contact with the borehole. Therefore, the carbon particles enhance the benefits of the fluid loss additives.
There remains a need for a blend of materials which can function more effectively to reduce fluid loss from a borehole in a wide range of circumstances, with water-based or oil-based fluids, which is compatible with the other functions desired in a drilling fluid, and which is economical to use.
SUMMARY OF THE INVENTION
In one embodiment of this invention, there is provided a drilling fluid additive comprising comminuted materials from the rice plant. In another embodiment there is provided a mixture comprising materials from the rice plant and other plant materials. In yet another embodiment there is provided a method of decreasing fluid loss from wellbores into subsurface formations by mixing comminuted rice products and other comminuted plant materials, adding the materials to drilling fluid and circulating the mixture through a well.
DESCRIPTION OF PREFERRED EMBODIMENTS
Rice fraction is available in the form of rice hulls, rice tips, rice straw and rice bran. These different parts of the rice plant are separated commercially and are widely available from rice mills. The rice fraction is a common by-product when finished rice is brought to market. Each of these products can be comminuted to very fine particle sizes by drying the products and using hammer mills, cutter heads or other comminution methods. Air classification equipment or other means can be used for separation of desired ranges of particle sizes using techniques well-known in industry.
Many other materials derived from natural plants are available in industry, some as by-products and some as principal products of those plants. These include the following materials: peanut hulls, wood fiber, cotton seed hulls, cotton seed stems, corn cobs, almond hulls, flax seed, flax stems, wheat hulls, wheat tips, wheat stems, wheat bran, coconut hulls, oat hulls, oat tips, oat stems, oat bran, sunflower seed hulls, sunflower seed stems, soybean hulls, soybean stems, maize, maize stems, rye grass seed, rye grass stems, millet seed, millet stems, and barley. All these plant materials are available in industry in comminuted form or they can be prepared using well-known techniques.
The size fraction of all these plant materials suitable for the present invention may be from about -65 mesh to about -100 mesh, but preferably is from about -65 mesh to about -85 mesh. Mesh size for purposes of this invention refers to standard U.S. mesh.
For preparation of blends of plant materials, the comminuted plant materials are mixed in the desired proportions in a dry solid blender. A ribbon blender is suitable for mixing. Appropriate concentrations of the rice fractions are in the range from about 50 per cent to about 90 per cent by weight of the total plant materials and other materials. Preferably, the concentration of rice fraction is in the range from about 75 per cent to about 90 per cent. The concentration of other plant material is preferably in the range from about 3 per cent to about 50 per cent by weight of the total plant materials and other materials.
Although carbon particles are not added to drilling fluid additives as a lost circulation material, it is convenient to add carbon particles along with a mixture of lost circulation materials because the carbon particles serve one of the functions of the lost circulation materials, that is, to reduce frictional resistance to movement of the drill pipe. The carbon particles may be any size from -20 mesh to -100 mesh, but preferably are in a size range from about -20 mesh to about -85 mesh.
When the plant materials of this invention are to be added to a water-based drilling fluid, it is also advantageous to add a small amount of oil to the mixture. This oil is preferably added while the rice fraction and other comminuted plant materials are being mixed in the desired ratio. This mixing may take place in a ribbon blender, where the oil in the required amount is applied by a spray bar. The oil wets the particles and adds to their lubricity while at the same time helping to control dust produced by the mixing operation. A variety of oils may be used for this invention. A suitable oil has been found to be ISOPAR V, available from Exxon Corporation, or an equivalent oil. Suitable concentrations of the oil are in the range from about 1 per cent to about 10 per cent by weight of the total weight of the mixture of plant materials.
It is known that water-soluble polymers further reduce the fluid loss rate through a mat or cake of fine solid materials. Therefore, it is preferable to add an effective amount of a polyanionic cellulosic type of polymer to the mixture of plant materials. A suitable polymer is carboxymethylcellulose, which is widely available. Suitable concentrations of the polymer are in a range from about 0.1 to about 0.5 per cent by weight.
To test the efficacy of comminuted plant materials for their ability to reduce lost circulation, the following tests were performed. A 60 cc plastic syringe was fitted with a piece of 60 mesh wire screen in the barrel of the syringe and filled half-full with 20-40 mesh round sand of the type commonly used for gravel packing of oil and gas wells. The packed sand had a permeability of about 120 darcies and a porosity of about 35 per cent. Mixtures of ground plant material and drilling fluid were prepared at a concentration of 15 pounds per barrel of drilling fluid. The plant materials were weighed and mixed with 350 ml of water-based drilling fluid and agitated for 5 minutes. The mixture was then poured into the top of the syringe and pressure was applied with the plunger until the drilling fluid was forced out of the end of the syringe or a seal formed at the sand/fluid interface. When a seal formed, the length of penetration of fluid into the sand column was then measured. Results were as follows:
TABLE I______________________________________Fluid Penetration into SandFluid Depth of Intrusion, cm.______________________________________Water No sealAdded rice fraction 3.4Added peanut hulls 4.3Added rice fraction/peanut 2.9hulls - 50/50 mix______________________________________
The rice fraction alone decreased fluid loss to a lower value than did the peanut hulls. I discovered, surprisingly, that a synergistic effect was found with a mixture of rice fraction and peanut hulls. The reason for the synergistic effect is not known, but it is believed to result from the different hardness or shape of the particles resulting from the comminution process applied to the different plant materials.
Only water base was used for testing, but similar seal action has been experienced in using the materials in oil base mud.
The fluid loss additive may be used in a pill or slug by mixing in a separate tank the additive with a small portion of the drilling fluid being used to drill a well. Alternatively, it may be added to the drilling fluid by blending or mixing the additive with the entire drilling fluid volume being used to drill a well. Concentrations of the fluid loss additive in a pill or slug may range over a wide range, but preferably are in the range from about 10 pounds per barrel to about 40 pounds per barrel. When added to the entire volume of the drilling fluid, concentrations of the fluid loss additive preferably range from about 5 pounds per barrel to about 40 pounds per barrel.
EXAMPLE 1
A fluid loss additive suitable for control of lost circulation during drilling operations of a well is formulated as follows:
______________________________________Rice fraction (-85 mesh) 82.8 wt %Peanut hulls (-65 to -85 mesh) 11.6Carbon beads (fine) 3.8Carboxymethylcellulose (reg.) 0.4Oil 1.5______________________________________
Excessive amounts of water-based drilling fluid are being lost from a well. The loss is believed to be caused by highly permeable formations which have been penetrated by the wellbore. A pill for lost circulation is mixed by placing 60 barrels of the drilling fluid in a tank and blending into the drilling fluid the fluid loss additive at a concentration of 15 pounds of additive per barrel of drilling fluid. The pill is then pumped down the drill pipe and up the annulus between the drill pipe and the borehole. The fluid loss rate from the well decreases to a value that is negligible.
The invention has been described with reference-to its preferred embodiments. Those of ordinary skill in the art may, upon reading this disclosure, appreciate changes or modifications which do not depart from the scope and spirit of the invention as described above or claimed hereafter.
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An additive to reduce fluid loss from drilling fluids is comprised of comminuted products from the rice plant or blends of other comminuted plant materials with the rice products. Polymers to reduce fluid loss even lower and friction-reducing materials may be added to the plant materials.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2003-153078, filed May 29, 2003, the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an optical head apparatus which records or reproduces data with respect to an optical disk and an optical head transferring method. Furthermore, the present invention relates to an optical disk apparatus which uses the above-described optical head apparatus.
2. Description of the Related Art
As is well known, there has been widely prevailed so-called multi disk drive equipment which not only can record and reproduce data with respect to a CD (i.e., a compact disk) but also can record and reproduce data with respect to an optical disk such as a DVD (i.e., a digital versatile disk).
The multi disk drive equipment of this type is used in equipment incorporated in a note book type personal computer or the like in addition to use as external equipment for a desk top type personal computer or the like, and therefore, its outside dimension is reduced in size and thickness as possible.
There is provided a feed mechanism in a general optical disk apparatus since an optical head for recording and reproducing data with respect to the optical disk must be moved in the radial direction of the optical disk. Such a feed mechanism is configured in such a manner as to convert the rotating force of a motor into a linear motion by means of a gear and a rack so as to transmit the force to the optical head.
Consequently, a play, that is, a backlash generated when the gear and the rack mesh with each other induces a drawback from the viewpoint of the accuracy of the transfer of the optical head. As a result, suppression of such a backlash without degrading miniaturization has been an important problem to enhance the accuracy of the transfer of the optical head.
Jpn. Pat. Appln. KOKAI Publication No. 2002-216442 discloses the configuration in which two racks are superimposed one on another to urge each other oppositely in a longitudinal direction by resilient force, so as to achieve favorable meshing with a pinion gear. Moreover, Jpn. Pat. Appln. KOKAI Publication No. 11-353824 discloses the configuration in which a pinion is pressed against a rack via a spring.
However, in the former configuration, the two racks need be superimposed one on another, thereby inducing a complicated configuration. In contrast, in the latter configuration, since the rotating pinion is pressed against the rack via the spring, a supporting mechanism for the pinion has a complicated and huge configuration, thereby arising a problem that a size cannot be reduced.
Additionally, Jpn. Pat. Appln. KOKAI Publication No. 7-93920 discloses the configuration in which a feed rack is moved in parallel to a rod, and further, the driving force of a gear is made constant by making a load applied on the gear uniform, thus eliminating a backlash.
In addition, Jpn. Pat. Appln. KOKAI Publication No. 7-122004 discloses the configuration in which an optical pickup can be moved with smaller acceleration so as to enhance track followability by alleviating an influence of slide friction.
Furthermore, Jpn. Pat. Appln. KOKAI Publication No. 7-147018 discloses the configuration in which a rack and a gear are brought into smooth contact with each other by integrally forming a base provided with the rack of a plastic-based material, thus reading information with high accuracy.
However, the techniques disclosed in Jpn. Pat. Appln. KOKAI Publication Nos. 7-93920, 7-122004 and 7-147018 merely have had the complicated configuration and the large size, and therefore, they have not reached a practical and satisfactory level in current circumstances.
BRIEF SUMMARY OF THE INVENTION
According to one aspect of the present invention, there is provided an optical head apparatus comprising: a head unit configured to irradiate an optical disk with a light beam for recording or reproducing data; a holder configured to fix the head unit thereto; a support unit configured to movably support the holder in a radial direction of the optical disk; a support member configured to be fixed to the holder; a rack unit configured to movably engage with the support member within a predetermined range and to have a rack along a moving direction of the holder; a gear configured to mesh with the rack of the rack unit, so as to transmit rotating force of a drive source to the rack; and an urging unit configured to urge the rack unit against the support member in such a manner that the rack meshes with the gear by a predetermined resilient force.
According to one aspect of the present invention, there is provided an optical head transferring method comprising: fixing a head unit which irradiates an optical disk with a light beam for recording or reproducing data, securing a support member to a holder movably supported in a radial direction of the optical disk, allowing a rack unit having a rack along a moving direction of the holder to movably engage with the support member within a predetermined range, and further, urging the rack unit against the support member in such a manner that the rack meshes with a gear by a predetermined resilient force; and rotating and driving the gear, so as to apply driving force to the rack, thus moving the head unit in the radial direction of the optical disk.
According to one aspect of the present invention, there is provided an optical disk apparatus comprising: a tray configured to allow an optical disk to be placed thereon; a loading unit configured to move the tray between a first position, at which the optical disk can be loaded or unloaded, and a second position, at which the optical disk is rotated to be driven; a head unit configured to irradiate the optical disk placed on the tray moved to the second position by the loading unit with a light beam for recording or reproducing data; a holder configured to fix the head unit thereto; a support unit configured to movably support the holder in a radial direction of the optical disk; a support member configured to be fixed to the holder; a rack unit configured to movably engage with the support member within a predetermined range and to have a rack along a moving direction of the holder; a gear configured to mesh with the rack of the rack unit, so as to transmit rotating force of a drive source to the rack; and an urging unit configured to urge the rack unit against the support member in such a manner that the rack meshes with the gear by a predetermined resilient force.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
FIG. 1 is an external view illustrating an optical disk apparatus in an embodiment according to the present invention;
FIG. 2 is a view illustrating the state of a disk loading unit in the optical disk apparatus, viewed from the top;
FIG. 3 is a view illustrating the state of the disk loading unit in the optical disk apparatus, as viewed from the bottom;
FIG. 4 is a view illustrating the state in which a tray is contained inside of a base member in the disk loading unit;
FIG. 5 is a view illustrating the state in which the tray is drawn from the base member in the disk loading unit;
FIG. 6 is a view illustrating the state of a chassis in the disk loading unit, viewed from the top;
FIG. 7 is a view illustrating the state of the chassis in the disk loading unit, viewed from the bottom;
FIG. 8 is a view illustrating the detail of a feed mechanism in the disk loading unit;
FIG. 9 is a view illustrating the detail of a support member in the feed mechanism;
FIG. 10 is a view illustrating the state in which a rack unit is fixed to the support member in the feed mechanism;
FIGS. 11A and 11B are views illustrating the detailed structure of the support member and the rack unit in the feed mechanism, respectively; and
FIG. 12 is a view illustrating a modification of the feed mechanism.
DETAILED DESCRIPTION OF THE INVENTION
An embodiment according to the present invention will be described below in reference to the accompanying drawings. FIG. 1 is an external view of an optical disk apparatus 11 illustrated in this embodiment. That is, the optical disk apparatus 11 is provided with a cabinet 12 formed into a box of a substantially thin type.
At the center of a front panel 13 in the cabinet 12 is disposed a disk loading unit 14 , which is adapted to load or unload an optical disk such as a CD or a DVD by putting in or out a tray, described later, outward of the front panel 13 in the cabinet 12 .
Furthermore, a power source key 15 is disposed at one end of the front panel 13 in the cabinet 12 . Moreover, at the other end of the front panel 13 are provided a display unit 16 for displaying an operating state and a plurality of operating keys 17 for setting the optical disk apparatus 11 in a predetermined operative state or an inoperative state.
FIG. 2 illustrates the state in which the disk loading unit 14 is taken out, as viewed from the top. That is, a base member 18 serves as a fixing base for directly or indirectly supporting various component parts.
The base member 18 includes a top plate 18 a , side plates 18 b and 18 b formed at both ends facing to the top plate 18 a , a bottom plate 18 c , not illustrated in FIG. 2 , extending from the side plates 18 b and 18 b and facing to the top plate 18 a , and a front plate 18 d , not illustrated in FIG. 2 , for connecting the respective fore ends of the side plates 18 b and 18 b to each other and having a clearance formed thereat, into which a tray 22 , described later, is loosely inserted between the top plate 18 a and the same.
Among these constituent parts, a connecting plate 19 is disposed across the side plates 18 b and 18 b . At the center of the connecting plate 19 is fixed a clamp member 21 via a fixing piece 20 having resiliency. The clamp member 21 is urged by the fixing piece 20 inward of the base member 18 via an opening 21 a formed at the top plate 18 a of the base member 18 .
Additionally, the tray 22 is supported by the base member 18 . The tray 22 is supported in a freely slidable manner in a lateral direction in FIG. 2 in the state in which a disk placing portion 22 a faces to the top plate 18 a . In this case, the tray 22 is supported in a freely slidable manner while both side faces thereof are fixed via bosses disposed at the bottom plate 18 c of the base member 18 .
FIG. 3 illustrates the state in which the disk loading unit 14 is viewed from the bottom. Namely, a chassis 23 is supported by the bottom plate 18 c of the base member 18 in such a manner as to face to the bottom of the tray 22 . On the chassis 23 are mounted a turn table, an optical head and the like, described later.
In the chassis 23 , projections 23 a an 23 a formed at one end are rotatably supported by the bottom plate 18 c . Consequently, the chassis 23 can be supported to be moved in a tilting direction on the projections 23 a and 23 a as fulcrums at the other end thereof.
By the chassis 23 is supported a drive motor 24 . To the rotary shaft of the drive motor 24 is fitted a worm gear 25 . The worm gear 25 meshes with a worm wheel 26 rotatably supported by the chassis 23 , so that the rotating force of the drive motor 24 is transmitted to the worm wheel 26 .
In this manner, the worm wheel 26 is rotated by the rotating force of the drive motor 24 , and therefore, the tray 22 , the chassis 23 , the optical head and the like can be moved.
FIG. 4 illustrates the state of the tray 22 contained inside of the base member 18 , as viewed from the side. In this case, the chassis 23 is controlled at a position above the tray 22 . At this position, the optical disk is lifted up from the tray 22 by the turn table, so as to be held between the clamp member 21 and the turn table, and further, an optical head faces to a signal recording surface of the optical disk.
FIG. 5 illustrates the state in which the tray 22 is drawn from the base member 18 , as viewed from the side. In this case, the chassis 23 is controlled at a position under the tray 22 . At this position, the turn table is separated from the optical disk, which is placed on the tray 22 .
FIG. 6 illustrates the state of the chassis 23 , as viewed in the direction of FIG. 2 . FIG. 7 illustrates the state of the chassis 23 , as viewed from the bottom, that is, in the direction of FIG. 3 . FIG. 8 illustrates a part of a feed mechanism for transferring the optical head from the state illustrated in FIG. 6 .
In other words, the turn table 27 is fitted to the rotary shaft of a disk motor (not illustrated) fixed to the chassis 23 , to be thus rotated and driven by the rotating force of the disk motor.
Furthermore, the above-described optical head 28 is fixed to the chassis 23 . This optical head 28 is constituted of a head unit 29 provided with a laser diode and a photo diode which are not illustrated, a printed circuit board 30 to which the head unit 29 is fixed, and a holder 31 to which the printed circuit board 30 is fixed.
The optical head 28 is movably supported in a direction in which the optical head 28 approaches the turn table 27 , and in a direction in which the optical head 28 is separated from the turn table 27 , by a pair of guide shafts 32 and 33 secured in parallel to the chassis 23 .
In this case, in the holder 31 are supported a holding member 34 slidably engageable with the guide shaft 32 and other holding members 35 slidably engageable with the guide shaft 33 . Moreover, the optical head 28 is slidably supported by the guide shafts 32 and 33 via the holding members 34 and 35 , respectively.
Here, as illustrated in FIG. 8 , the holding member 34 engageable with the guide shaft 32 is constituted of a single member; in contrast, the two holding members 35 engageable with the guide shaft 33 are arranged at a predetermined interval along the axial direction of the guide shaft 33 .
These two holding members 35 , 35 are contained inside of a support member 36 fixed to the holder 31 . With the support member 36 , a rack unit 38 having a rack 37 formed outward movably engages via urging means, described later. A pinion gear 39 meshes with the rack 37 .
The rotation of the pinion gear 39 enables the driving force in the axial direction of the guide shafts 32 and 33 to be transmitted to the rack 37 , so that the optical head 28 is transferred under the guide of the guide shafts 32 and 33 . The pinion gear 39 can be rotated and driven by the drive motor 24 .
That is, as illustrated in FIG. 7 , the worm gear 25 is fitted to the rotary shaft of the drive motor 24 . The worm gear 25 meshes with the worm wheel 26 rotatably supported by the chassis 23 , so that the rotating force of the drive motor 24 is transmitted to the worm wheel 26 .
The pinion gear 39 is integrally formed coaxially with the worm wheel 26 . Consequently, the pinion gear 39 is driven by the drive motor 24 via the worm wheel 26 , and then, the optical head 28 is transferred. Incidentally, as the worm wheel 26 may be used, for example, a spur gear or a helical gear.
Here, FIG. 6 illustrates the state in which the optical head 28 is positioned at the innermost circumference of the optical disk, in other words, the state in which the optical head 28 approaches most the turn table 27 . The optical head 28 is transferred from the position illustrated in FIG. 6 in a direction separated from the turn table 27 by the rotation in one direction of the drive motor 24 . Additionally, the optical head 28 is transferred near the turn table 27 by the rotation of the drive motor 24 in the other direction.
Here, a connector 40 is disposed in the printed circuit board 30 having the head unit 29 fixed thereto. When a cable 41 is connected to the connector 40 , a signal is received from or transmitted to the head unit 29 .
In FIG. 9 , the support member 36 illustrated in FIG. 8 is shown in detail by a slash line. Furthermore, FIG. 10 illustrates FIG. 9 , as viewed from the bottom, in particular, in which the rack unit 38 is shown in detail. Incidentally, the guide shaft 33 is omitted in FIGS. 9 and 10 for the sake of simplification.
In FIG. 9 , the support member 36 indicated by the slash line is made of a resin, and is provided at the center thereof with containers 36 d and 36 d in a substantially box shape, for containing therein the holding members 35 and 35 , respectively. The support member 36 is formed into a substantially plate shape on both longitudinal sides of the containers 36 d and 36 d for the holding members 35 and 35 , respectively, and then, is fixed to the holder 31 via a screw 42 .
Moreover, bosses 36 a and 36 b are formed at both longitudinal ends of the support member 36 , and further, a projection 36 c for allowing a tension spring 43 , described later, to be hooked thereon is formed near the containing positions of the holding members 35 and 35 .
FIG. 10 illustrates the rack unit 38 incorporated in the support member 36 , as viewed from the rack unit 38 , in which the support member 36 is indicated by a slash line.
The rack unit 38 is made of a resin, and the rack 37 is integrally formed at one edge in the longitudinal direction of the rack unit 38 . At both ends of the rack unit 38 are formed openings 381 and 382 , at the edges of which engaging portions 38 a and 38 b engageable with the respective tips of the bosses 36 a and 36 b of the support member 36 are formed.
One end of each of the openings 381 and 382 is widely formed so as to allow the bosses 36 a and 36 b of the support member 36 to be inserted; in contrast, at the respective other ends of the openings 381 and 382 are formed tapered portions 38 c and 38 d.
Additionally, a hook 38 e for allowing the tension spring 43 to be hooked between the projection 36 c and itself is formed at the center of the rack unit 38 in the longitudinal direction. Moreover, a resilient piece 38 f , which can be displaced in a thickness direction, is formed at the rack unit 38 . The resilient piece 38 f has the function of a stopper for preventing the rack unit 38 from being detached from the support member 36 .
In order to incorporate the rack unit 38 into the support member 36 such configured as described above, first, the resilient piece 38 f of the rack unit 38 is displaced in the thickness direction, and then, the bosses 36 a and 36 b of the support member 36 are inserted through wide portions of the openings 381 and 382 , respectively, to engage at the tips thereof with the engaging portions 38 a and 38 b . Thus, the rack unit 38 can be movably supported by the support member 36 within the range of the openings 381 and 382 .
When the wide portions of the openings 381 and 382 in the rack unit 38 move near the bosses 36 a and 36 b of the support member 36 , the tip of the projection 36 c of the support member 36 abuts against the resilient piece 38 f of the rack unit 38 , thereby restricting the movement. As a consequence, the bosses 36 a and 36 b can be inhibited from reaching the wide portions of the openings 381 and 382 . In other words, the rack unit 38 cannot be detached from the support member 36 in a normal operating state.
When the coil-like tension spring 43 is hooked between the projection 36 c of the support member 36 and the hook 38 e of the rack unit 38 in the state in which the rack unit 38 engages with the support member 36 , the rack unit 38 is urged by the resilient force in such a manner that the tapered portions 38 c and 38 d are press-fitted to the bosses 36 a and 36 b.
At this time, with the tapered portions 38 c and 38 d , the rack unit 38 receives force in such a manner as to be shifted in the direction of the rack 37 , and therefore, the rack 37 is press-fitted to the pinion gear 39 by force according to the resilient force of the tension spring 43 . Thus, it is possible to efficiently suppress a backlash between the rack 37 and the pinion gear 39 .
FIG. 11A illustrates the support member 36 ; and FIG. 11B illustrates the rack unit 38 . In FIG. 11A , a surface facing to the rack unit 38 is indicated by a slash line, and further, the containers 36 d and 36 d , in which the holding members 35 and 35 are contained, respectively, are formed at the intermediate portion.
In the support member 36 , there are formed a pair of projections 36 e at each of both ends in the longitudinal direction, projecting from the surface facing to the rack unit 38 in a vertical direction. The support member 36 is configured in such a manner as to be brought into contact with the rack unit 38 via the projections 36 e , such that the rack unit 38 can securely slide with ease.
In FIG. 11B , the rack unit 38 is integrally made of a resin, and further, an opening 383 is formed also at a portion at which the tension spring 43 is disposed at the center, in addition to the two openings 381 and 382 formed at both ends.
In the above-described embodiment, the support member 36 is secured to the holder 31 having the head unit 29 fixed thereto, and the rack unit 38 having the rack 37 formed thereat is fixed to the support member 36 via the urging means in such a manner that the rack 37 meshes with the pinion gear 39 at a predetermined pressure. As a consequence, it is possible to securely suppress the backlash generated between the pinion gear 39 and the rack 37 by the simple structure, so as to stably transfer the optical head 28 .
Incidentally, although the support member 36 is secured to the holder 31 via the screw 42 in the above-described embodiment, it is possible to reduce the number of component parts and simplify the configuration if a support unit 44 having the same function as that of the support member 36 is formed integrally with the holder 31 , as illustrated in FIG. 12 .
Furthermore, although the bosses 36 a and 36 b are formed at the support member 36 and the tapered portions 38 c and 38 d are formed at the rack unit 38 in the above-described embodiment, tapered portions may be formed at the support member 36 while bosses may be formed at the rack unit 38 .
It is to be understood that the present invention is not restricted to the embodiment, and that the constituent elements can be variously and specifically modified in embodiments without departing from the scope of the present invention. Moreover, the invention having various features can be devised by appropriately combining the plurality of constituent elements described in the above-described embodiment. For example, some constituent elements may be omitted from all of the constituent elements described in the embodiment. Additionally, constituent elements in another embodiment may be appropriately combined with each other.
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An optical head apparatus comprises a head unit for irradiating an optical disk with a light beam for recording or reproducing data, a holder for fixing the head unit thereto, a support unit for movably supporting the holder in a radial direction of the optical disk, a support member fixed to the holder, a rack unit movably engageable with the support member within a predetermined range and having a rack along a moving direction of the holder, a gear meshing with the rack of the rack unit, so as to transmit rotating force of a drive source to the rack, and an urging unit for urging the rack unit against the support member in such a manner that the rack meshes with the gear by a predetermined resilient force.
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BACKGROUND OF THE INVENTION
Multiple piston oil well stimulation and service devices, such as mud pumps or intensifiers and detensifiers are known. Two ram duplex pumping apparatuses are shown in the patents of Hall, et al, U.S. Pat. No. 3,773,438 of Nov. 20, 1973 and U.S. Pat. No. 3,967,542 of July 6, 1976, and a control for a duplex pump is shown in Hall, U.S. Pat. No. 3,981,622 of Sept. 22, 1976.
A characteristic of a typical oil well high-pressure pumping unit resides in the fact that when one of the ram drive cylinders has completed its forward or working stroke, the very high pressure hydraulic fluid behind the driving piston is released or dumped into the reservoir or tank. While the resultant loss of energy may not seem to be significant when compared to the total amount of energy expended by these large units, the fact is that it can amount to about 2% of the total energy being used, and this can be significant in self-contained systems in which the hydraulic fluid operates through a closed path. In such closed hydraulic systems the unspent or unused energy in the form of heat must be removed from the hydraulic fluid to prevent the same from overheating.
The oil well pumps of the general kind described are commonly operated in regions in which the ambient temperatures may be rather high. Thus, a self-contained system must contain sufficient cooling apparatus and capacity to prevent the hydraulic fluid from exceeding a predetermined maximum temperature. Above this temperature the seals and other parts, as well as the oil, are subject to rapid deterioration. Generally, the desired operating temperature is considered to be about 150° F. The life of the seals is particularly critical, since any kind of operation which shortens or reduces the life of the hydraulic seals substantially increases the likelihood of a premature overhaul or seal change, an expensive and time consuming operation during which time the equipment is idle. The problem of lost energy in the form of heat is further aggrevated by the fact that, in most locations, cooling water is not available, and expensive air operated heat exchangers must be used. The differential temperature, for the purpose of cooling, during mid-day operation, can be rather narrow.
SUMMARY OF THE INVENTION
The present invention is directed to a four piston oil well pumping unit, which may be adopted for use as a mud pump, or it may be used as an intensifier or a detensifier. The unit, however, is not limited to the oil well industry and it may be used for placing or moving slurries or liquid materials, in general, such as coal dust slurries or concrete.
Four hydraulic drive cylinders are respectively connected to operate four fluid ram units, in two pairs of two cylinder-ram combinations. In other words, pairs of cylinders are interconnected in such a manner that when the piston in one is moving forwardly the other is moving rearwardly. This is accomplished by interconnecting the cylinder annulus of each of the cylinders in each pair so that forward movement is accompanied by the retracting movement of the other at substantially the same rate.
The invention includes a precompression-decompression energy saving control valve for each of the interconnected pairs of cylinders. The control valve functions to transfer the stored energy contained in the cylinder which has just completed its stroke, by interconnecting the same to its paired cylinder which has not yet begun its stroke. In this manner, the energy contained in the highly pressurized hydraulic fluid within the large capacity of the extended cylinder is not wasted by dumping the same back to the tank, but is conserved by applying such energy to the opposite cylinder, which is in its retracted position, to partially precompress the fluid in that cylinder.
The precompression-decompression valve arrangement also has the function of connecting such partially precompressed cylinders to line pressure from an accumulator to complete precompression to provide a quadraplex fluid pump which has uniform suction and discharge characteristics. One of the four cylinders are always moving in one direction while the other of its pair is moving in the opposite direction. Utilizing the compressed fluid of one of a pair of fluid cylinders to precompress a further cylinder prior to admitting the pressure from the pump, not only saves energy, which would otherwise be converted to heat, but reduces hydraulic shock when full pressure is applied to the system.
It is accordingly an important object of this invention to provide a four cylinder hydraulic pumping unit in which pairs of the cylinders are interconnected to each other, and further including a control valve for prepressurizing one cylinder of each pair from the hydraulic fluid contained under pressure in the other cylinder of the pair, at the conclusion of each stroke.
A further advantage of the invention is the provision of a quadraplex pumping unit in which four hydraulic pistons and four associated pumping rams or cylinders work at a lower cycling rate than that of a comparable duplex or triplex system, thereby extending the life of the cylinders, as well as the life of the seals.
Another object of the invention is the provision of a control valve for operating a four cylinder pumping unit in which energy is saved by applying the stored energy of a just extended cylinder to a just retracted cylinder.
A further object of the invention is the provision of a pumping unit in which a separate control valve for each pair of two cylinders provides for pressure equalization and for prepressurization from a source of high pressure.
These and other objects and advantages of the invention will be apparent from the following description, the accompanying drawings, and the appended claims.
BRIEF DESCRIPTION OF THE DRAWING
The drawing represents a schematic diagram of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the single FIGURE of the drawing, four identical fluid rams are illustrated by the reference numerals 10, 11, 12 and 13. For the purpose of this invention, rams 10 and 11 may be considered as a first pair of fluid rams, and rams 12 and 13 as a second pair of fluid rams. The rams are connected to a common header or outlet section 15, by means of which fluid is brought in through a suction line 16 and discharged under pressure through a fluid outlet line 17. The header 15 includes one way valves or isolation check valves arranged with the outlets of each of the fluid pressure rams to control the flow of liquid into or out of the ram cvlinders, which include valves V-18 and V-22 associated with ram 10, valves V-19 and V-23 associated with ram 11, valves V-20 and V-24 associated with ram 12, and valves V-21 and V-25 associated with the outlet of ram 13. The rams 10 through 13 each include working ram pistons 10a-13a.
The movements of the ram working pistons are controlled by hydraulic drive cylinders comprising cylinders 20, 21, 22 and 23 connected respectively with the rams 10, 11, 12 and 13. Cylinders 20 and 21 comprise one pair, and 22 and 23 comprise a second pair. Each of the cylinders 20-23 includes an internal piston 25 and a connecting or piston rod 26 which is directly connected to its respective ram piston through a coupling 27. The rods 26, in their respective cylinders, form annulus spaces 28 forward of the piston 25. The annulus spaces 28 of each of the above-defined piston pairs are connected in common, and thus the annulus spaces 28 of the cylinders 20 and 21 are connected in common by a line 30, and the corresponding respective annulus spaces in the cylinders 22 and 23 are connected by a line 32. The innerconnection of the annulus spaces 28 of the cylinders assures that when one piston 25 is moving outwardly or in a forward direction, the displacement of fluid from its annulus space is transmitted to the annulus space of the companion or paired cylinder, so that the piston of that cylinder is moving rearwardly or retracting at the same rate.
The forward or extended position of each of the cylinders is defined by limit switches LS-2, LS-4, LS-6, and LS-8, respectively, for the rams 10, 11, 12 and 13, while the retracted positions of these same cylinders is sensed respectively by limit switches LS-1, LS-3, LS-5 and LS-7.
The primary application of motive force to the cylinders 20, 21, 22 and 23 is applied through a valve control circuit from a common source of hydraulic fluid under pressure. The details of the source include a hydraulic oil supply tank T-1 from which a super-charging pump P-3 delivers hydraulic fluid at approximately 150 pounds pressure to the inlet of a primary engine driven pump P-1. A heat exchanger 30 is interposed in the line between pump P-3 and pump P-1 for removing excessive heat from the hydraulic fluid.
The pump P-1 is driven by an engine 35, which may be a diesel engine, or turbine engine or the like, to provide the necessary energy input into the system. For example, the engine driven pump may have as little as 100 hp or up to 4,000 hp or more, to provide an output which may have a pressure of up to 10,000 psi, as controlled by a pressure relief and by-pass valve assembly V-3.
The output of the pump P-1 is applied to a common line 40. A precharging accumulator 45 receives hydraulic fluid pressure from the pump P-1 through an orifice V-5 and a check valve V-6.
A pilot supply of lower pressure fluid is provided by a smaller pump P-2, driven from the primary pump P-1, and provides pressure for actuation of the hydraulic valves, at approximately 500 psi. It also provides for make-up fluid along a line 47 and through a restrictor V-12 and a check valve V-13 to the junction of the interconnecting lines 30 and 32 through isolation check valves V-14 and V-15.
The energy saving decompression and precompression valves are illustrated at 50 and at 51. These valves are identical in structure and function, and operate to interconnect the respective pairs of cylinders 20 and 21 (valve 50) and 22 and 23 (valve 51), to provide for the partial precompression of one cylinder of a pair from the stored energy in the other cylinder of that pair. Hydraulic fluid under extreme pressure is selectively applied to each of the cylinders from line 40 through on/off control valves A-1, B-1, C-1 and D-1, while discharge from the cylinders 20-23 to the tank T-1 is through a corresponding set of controllable discharge valves A-2, B-2, C-2 and D-2.
The operation of the invention will be understood from the following description. As noted, the primary pump P-1 can vary in size from a relatively small horsepower of approximately 100 hp to a pumping unit up to 4,000 hp or more, but for the purposes of the present description it may be considered as having a nominal power input of approximately 1,000 hp. This pump commonly has the capacity of providing an output pressure of as high as 10,000 psi or higher. This pressure can either be intensified or detensified by the cylinder and ram combinations. For example, oil field requirements often require an increase or an intensification of pressure such as for use in oil well fracturing, or may require a lower output pressure at higher volumes as in the case of mud pumps.
The primary pump P-1 is supplied from a supercharging source which includes a pump P-3. The pump P-3 receives hydraulic fluid from the storage tank T-1 and applies this fluid to the primary pump P-1 at 150 psi, for example, through a heat exchanger 30 and a filter 32. As noted above under "Background", frequently the operation of oil well hydraulic eouipment is limited by the ability effectively to control the maximum temperature of the hydraulic fluid. An air cooled heat exchanger 30 is shown, which typically must be used where water cooling is not reasonably available. Since the heat exchanger 30 must use air at ambient conditions, it is important that the hydraulic system not be unduly burdened with unnecessary wasted energy in the form of heat.
The hydraulic fluid from the principal or main pump P-1 is fed to the common line 40 to the valves A-1, B-1, C-1 and D-1. A small amount of fluid is bled from the pump P-1 to the accumulator 45 through the check valve V-6 and the restrictor V-5. The fluid from the accumulator is applied to the valves 50 and 51 respectively through check valves V-10, V-9 and flow control orifices V-7, V-8.
The valves 50, 51 are preferably three position, solenoid pressure operated, and each have four ports which are correspondingly numbered on the drawing. Port 1 receives precompession fluid from the accumulator 45, ports 2 and 3 are connected respectively to the cylinders 20 and 21 in the case of valve 50 (for cylinders 22 and 23 in the case of valve 51), and port 4 is connected to tank T-1. When the valve 50 or 51 is in the center position shown, the ports 1 and 4 are blocked and ports 2 and 3 are interconnected.
The valves 50 and 51 have the function of interconnecting cylinders 21, 22 and 22, 23 respectively, for pressure balancing, and provide precompression and decompression in accordance with a desired control sequence. The valves 50 and 51 are shown in the neutral position in which the cylinder pairs are interconnected. This interconnection of the cylinders allows for the compressed fluid in one cylinder to balance with the fluid in the other cylinder. In further explanation, assume rams 10 and 12 are retracted, resting respectively on limit switches LS-1 and LS-5, while rams 11 and 13 are extended, resting on limit switches LS-4 and LS-8. The pump P-1 is by-passing through the relief and by-pass valve V-3 under a controlled pressure. The pilot pump P-2 is being relieved through its pressure relief valve V-11 at an intermediate pressure of 500 psi, for example. The control valves 50 and 51 are de-energized in their center position as shown, and all two-way valves A, B, C and D are considered to be in their flow-blocking or closed positions, as shown.
The cycle is started by suitably pressing a start button on a control panel or in a control circuit. Valve 50 is energized so as to connect port 1 to port 2, and port 3 to port 4. This connects the inlet of cylinder 20 to high pressure through port 2 and connects the inlet to cylinder 21 to the tank through parts 3, 4. Valve 51 is energized at the same time to connect port 1 to port 2 and port 3 to port 4, thus connecting the inlet to cylinder 22 to high pressure and the inlet to cylinder 23 to the tank. It is also assumed that rams 10 and 12 are retracted and rams 11 and 13 are extended.
Valve V-3 is now energized to close off the internal relief valve and prevent by-passing. Also, valves A-1, B-2 and D-2 are operated. This causes the following: The pump P-1 delivers fluid to the piston of hydraulic cylinder 20 directly through valve A-1, and pressure will build up in the hydraulic cylinder 20 according to the resistance of the fluid pressure at ram 10 and the ratios of diameters. The cylinder rod 26 of the cylinder 20 will begin to extend, carrying with it the plunger 10a of the ram 10. As the annulus space 28 of the hydraulic cylinder 20 is interconnected with the corresponding annulus space at the cylinder 21, and as the control valve to the tank is open through valve B-2, the piston within the cylinder 21 will begin a retraction stroke at the same speed that the piston within the cylinder is extending.
While this is taking place, flow from the pump P-1 will be bled through orifice V-5 and check valve V-6 into the accumulator 45. The flow to the accumulator is also connected to valves 50 and 51 through check valves V-9 and V-10 and flow restrictor valves V-7 and V-8. As valves 50 and 51 are connected port 1 to port 2, flow will admit through check valve V-9 and orifice V-8 from the accumulator 45 into the hydraulic cylinder 22, thus prepressurizing the hydraulic cylinder 22 substantially to the system working pressure. The same flow will also be connected to the check valve V-10 associated with the three-way valve 50. However, the check valve V-10 will remain closed due to the pressure balance from the main pressure system at the primary pump P-1 being felt on the opposite side of the check valve V-10 from the hydraulic cylinder 20 to port 2 of the valve 50. In this condition, the ram 10 is moving forward, ram 11 is retracting at the same speed, the cylinder 22 for ram 12 is prepressurized, the cylinder 23 of ram 13 is connected to tank, and pressure and volume are being bled into the accumulator 45 through V-6.
As the piston in the hydraulic cylinder 21 retracts, the connector 27 will contact limit switch LS-3. This limit switch thus signals that the hydraulic cylinder 21 has in fact returned due to the interconnection of its annulus with the cylinder 20.
When the connector 27 of the hydraulic cylinder 20 reaches the extreme forward limit of its stroke, it will contact limit switch LS-2 and the following events occur in the following sequence:
(a) valve C-1 opens and cylinder 22 starts to extend;
(b) valve A-1 closes;
(c) valve B-2 closes;
(d) valve 50 moves to neutral center position connecting port 2 to port 1 for transfer of stored energy of cylinder 20 into cylinder 21, and a built-in time delay is initiated.
The above-identified valve sequences results in the following hydraulic cylinder movements:
(a) hydraulic cylinder 22 starts to extend;
(b) hydraulic cylinder 23 begins to retract at the same rate as hydraulic cylinder 22 extends;
(c) hydraulic cylinder 20 rests at its extended position;
(d) hydraulic cylinder 21 rests at its retracted position;
With hydraulic cylinder 20 fully stopped, cylinder 21 will pressure balance with 20 due to the interconnection of these cylinders through ports 2 and 3 of valve 50.
The initiated time delay may be relatively short, such as 100 milliseconds. After this time, sufficient to provide for pressure balancing and associated energy conservation thereby, valve 50 is energized to its down or cross-connecting position to connect port 1 to port 3 and port 2 to port 4 and a second short time delay is initiated. In its cross connected position, valve 50 now applies pressure from the accumulator 45 to cylinder 21, and cylinder 21 will be prepressurized close to the system working pressure, and at the same time, the extended cylinder 20 will now be fully decompressed to the tank through valve 50, ports 2 and 4.
At the conclusion of a second time delay, which may be approximately equal to the first time delay noted above, valve A-2 opens venting the cylinder 20 directly to the tank and by-passing valve 50. In the above condition, the hydraulic cylinder 22 is extending and hydraulic cylinder 23 is retracting at the same speed, while hydraulic cylinder 21 is precompressed close to the system working pressure and hydraulic cylinder 20 is now fully decompressed.
As hydraulic cylinder 23 retracts, it passes the limit switch LS-7, signalling that it is now retracted and that hydraulic cylinder 22 is fully extended, where it contacts limit switch LS-6 which operates the following valves in the following sequence:
(a) valve B-1 opens;
(b) valve C-1 closes;
(c) valve D-2 closes;
(d) valve 51 moves to its neutral position connecting port 2 to port 3, repeating a first time delay.
The above valve sequence results in the following hydraulic cylinder movements:
(a) hydraulic cylinder 21 begins to extend when valve B-1 opens connecting the hydraulic cylinder directly to the output of pump P-1;
(b) hydraulic cylinder 20 begins to retract at the same speed;
(c) hydraulic cylinder 22 is stopped in its extended position at limit switch LS-6;
(d) hydraulic cylinder 23 is fully retracted and at rest at its limit switch LS-7.
After this sequence is completed, the hydraulic cylinder 23 is interconnected with cylinder 22 through valve 51 and the pressures therebetween are balanced, thus conserving the stored energy and pressure from cylinder 22 and applying the same to cylinder 23. After the second time delay for pressure balancing of say 100 milliseconds, valve 52 moves to its opposite cross-connecting position in which port 1 is connected to port 3 and port 2 is connected to port 4, starting a second time delay, for complete decompression of cylinder 22 to the tank, while the flow from port 1 to port 3 through valve 2 allows fluid pressure from the accumulator 45 to flow into hydraulic cylinder 23, thus raising the pressure in hydraulic cylinder 23 close to the system working pressure. At the conclusion of the second time delay valve C-2 opens, thus completing the cycle.
The continuous reciprocating movement as defined above assures that one fluid ram of the four rams is always moving on a pumping stroke and one of the fluid rams is always moving on a suction or a return stroke to provide uniform pumping and suction to the fluid being pumped. The operation of the decompression and precompression energy saving valves 50 and 51 provides a closed loop system in which the high energy stored in a just extended cylinder is transferred and pressure balanced with its corresponding pair, namely, a just retracted cylinder, rather than released to tank, which would otherwise release the energy in the form of heat.
The above-defined operational sequences may, of course, be performed manually, but preferably may be performed with a microprocessing controller within the ability of those skilled in the art. The saving in energy resulting in the transfer of energy from the extended cylinder to the retracted cylinder of each of the cylinder pairs, prior to full prepressurization, permits a savings in energy which substantially lowers the burden of the heat exchanger 30 and permits the maintenance of hydraulic fluid temperatures within normal ranges. The four ram pumping unit has further advantages over existing two ram and three ram systems in that since only one ram is moving on a working stroke at any one time, the wear is distributed through four essentially identical working systems, thus extending the time between overhauls and making the system comparatively more efficient economically.
While the form of apparatus, herein described constitutes a preferred embodiment of this invention, it is to be understood that the invention is not limited to this precise form of apparatus, and that changes may be made therein without departing from the scope of the invention.
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A quadraplex pumping unit for use as a mud pump, an intensifier, or as a pump for abrasive fluids or the like includes four rams and four ram operating pistons. A control valve arrangement provides for pressure equalization and energy transfer from a cylinder which has just extended in a working stroke to a companion cylinder which has just returned to its retracted to rest position, to conserve energy and reduce the thermal burden on the hydraulic system. The valve arrangement further provides for prepressurization, after pressure equalization, prior to an extending stroke.
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FIELD OF THE INVENTION
This invention relates to a method for increasing oil production from oil wells producing a mixture of oil and gas it an elevated pressure through a wellbore penetrating an oil bearing formation containing an injection zone and an oil bearing zone by separating a portion of the gas from the mixture, utilizing energy from at least a portion of the mixture to compress at a surface the separated gas, and injecting the compressed gas into the injection zone.
BACKGROUND OF THE INVENTION
In many oil fields the oil bearing formation comprises a gas cap zone and an oil bearing zone. Many of these fields produce a mixture of oil and gas with the gas to oil ratio (GOR) increasing as the field ages. This is a result of many factors well known to those skilled in the art. Typically the mixture of gas and oil is separated into an oil portion and a gas portion at the surface. The gas portion may be marketed as a natural gas product, injected to maintain pressure in the gas cap or the like. Further, many such fields are located in parts of the world where it is difficult to economically move the gas to market therefore the injection of the gas preserves its availability as a resource in the future as well as maintaining pressure in the gas cap.
Wells in such fields may produce mixtures having a GOR of over 10,000 standard cubic feet per standard barrel (SCF/STB). In such instances, the mixture may be less than 1% liquids by volume in the well. Typically a GOR from 800 to 2,500 SCF/STB is more than sufficient to carry the oil to the surface as a gas/oil mixture. Normally the oil is dispersed as finely divided droplets or a mist in the gas so produced. In many such wells quantities of water may be recovered with the oil. The term "oil" as used herein refers to hydrocarbon liquids produced from a formation. The surface facilities for separating and returning the gas to the gas cap obviously must be of substantial capacity when such mixtures are produced to return sufficient gas to the gas cap or other depleted formations to maintain oil production.
Typically, in such fields, gathering lines gather the fluids into common lines which are then passed to production facilities or the like where crude oil, condensate, and other hydrocarbon liquids are separated and transported as crude oil. Natural gas liquids are then recovered from the gas stream and optionally combined with the crude oil and condensate. Optionally, a miscible solvent which comprises carbon dioxide, nitrogen and a mixture of light hydrocarbons such as the gas stream may be used for enhanced oil recovery or the like. The remaining gas stream is then passed to a compressor where it is compressed for injection. The compressed gas is injected through injection wells, an annular section of a production well, or the like, into the gas cap.
Clearly the size of the surface equipment required to process the mixture of gas and oil is considerable and may become a limiting factor on the amount of oil which can be produced from the formation because of capacity limitations on the ability to handle the produced gas.
It has been disclosed in U.S. Pat. No. 5,431,228 "Down Hole Gas-Liquid Separator for Wells" issued Jul. 11, 1995 Weingarten et al and assigned to Atlantic Richfield Company that an auger separator can be used downhole to separate a gas and liquid stream for separate recovery at the surface. A gaseous portion of the stream is recovered through an annular space in the well with the liquids being recovered through a production tubing.
In SPE 30637 "New Design for Compact Liquid-Gas Partial Separation: Down Hole and Surface Installations for Artificial Lift Applications" by Weingarten et al it is disclosed that auger separators as disclosed in U.S. Pat. 5,431,228 can be used for downhole and surface installations for gas/liquid separation. While such separations are particularly useful as discussed for artificial or gas lift applications and the like, all of the gas and liquid is still recovered at the surface for processing as disclosed. Accordingly, the surface equipment for processing gas may still impose a significant limitation on the quantities of oil which can be produced from a subterranean formation which produces oil as a mixture of gas and liquids.
Accordingly a continuing search has been directed to the development of methods which can increase the amount of oil which may be produced from subterranean formations producing a mixture of oil and gas with existing surface equipment.
SUMMARY OF THE INVENTION
According to the present invention, it has been found that increased quantities of oil can be produced from an oil well producing a mixture of oil and gas at an elevated pressure through a wellbore penetrating an oil-bearing formation containing an oil-bearing zone and an injection zone, by separating at least a portion of the gas from the mixture of oil and gas to produce a separated gas and an oil-enriched mixture; utilizing energy from at least a portion of the mixture of oil and gas to compress at a surface at least a portion of the separated gas to produce a compressed gas having sufficient pressure to be injected into the injection zone; injecting the compressed gas into the injection zone; and recovering at least a major portion of the oil-enriched mixture.
The invention further comprises a system for increasing oil production from an oil well producing a mixture of oil and gas at an elevated pressure through a wellbore penetrating a formation containing an oil-bearing zone and an injection zone, wherein the system comprises a separator in fluid communication with the oil-bearing zone; turbine positioned on the surface and having an inlet in fluid communication with the separator; and a compressor positioned on the surface, the compressor being drivingly connected to the turbine and having a gas inlet in fluid communication with a separated gas discharge outlet on the separator, the compressor further having a compressed gas discharge outlet in fluid communication through a passageway with the injection zone.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a production well, according to the prior art, for producing a mixture of oil and gas from a subterranean formation and an injection well for injecting gas back into a gas cap in the oil bearing formation.
FIG. 2 is a schematic diagram of a downhole portion of an embodiment of the system of the present invention in which gas is separated downhole from liquids in a formation, produced through a production well to a surface where it is compressed, and injected through a dedicated injection well back into a gas cap in the formation;
FIG. 3 is a schematic diagram of a downhole portion of a portion of an alternate embodiment of the system of the present invention in which gas is separated downhole from liquids in a formation, produced through a production well to a surface where it is compressed, and injected through another production well, acting as an injection well, back into a gas cap in the formation;
FIG. 4 is a schematic diagram of a downhole portion of an alternate embodiment of the system of the present invention in which gas is separated downhole from liquids in a formation, produced through a production well to a surface where it is compressed, and injected through an annulus of the production well back into a gas cap in the formation;
FIG. 5 is a schematic diagram of a downhole portion of an alternate embodiment of the system of the present invention in which gas is separated at a surface from liquids produced from a formation, compressed, and injected through the production well back into a gas cap in the formation;
FIG. 6 is a schematic flow diagram of a surface portion of an alternate embodiment of the system of the present invention for compressing gas using energy from an oil-enriched mixture of oil and gas;
FIG. 7 is a schematic flow diagram of a surface portion of an alternate embodiment of the system of the present invention for compressing gas using energy from gas from an oil well;
FIG. 8 is a schematic flow diagram of a surface portion of an alternate embodiment of the system of the present invention for compressing gas using a heater;
FIG. 9 is a schematic flow diagram of a surface portion of an alternate embodiment of the system of the present invention for compressing gas using energy derived from an external source; and
FIG. 10 is a schematic flow diagram of a surface portion of an alternate embodiment of the system of the present invention for compressing gas using energy derived from an external source.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the discussion of the Figures, the same numbers will be used to refer to the same or similar components throughout. Certain components of the wells necessary for the proper operation of the wells, and certain pumps, valves, and compressors necessary to achieve proper flow of fluids, have not been discussed in the interest of conciseness.
In FIG. 1, depicting the prior art, a production oil well 10 is positioned in a wellbore (not shown) to extend from a surface 12 through an overburden 14 to an oil bearing formation 16. The production oil well 10 includes a first casing section 18, a second casing section 20, a third casing section 22, and a fourth casing section 24, it being understood that the oil well may alternatively include more or fewer than four casing sections. The use of such casing sections is well known to those skilled in the art for the completion of oil wells. The casings are of a decreasing size and the fourth casing 24 may be a slotted liner, a perforated pipe, or the like. While the production oil well 10 is shown as a well which has been curved to extend horizontally into the formation 16, it is not necessary that the well 10 include such a horizontal section and, alternatively, the well 10 may extend only vertically into the formation 16. Such variations are well known to those skilled in the art for the production of oil from subterranean formations.
The oil well 10 also includes a tubing string referred to herein as production tubing 26 for the production of fluids from the well 10. The production tubing 26 extends upwardly to a wellhead 28 shown schematically as a valve. The wellhead 28 contains the necessary valuing and the like to control the flow of fluids into and from the oil well 10, the production tubing 26, and the like.
The formation 16 includes a selected injection zone 30 and an oil bearing zone 32 underlying the injection zone 30. The selected injection zone 30 may be a gas cap zone, an aqueous zone, an upper portion of the oil bearing zone 32, a depleted portion of the formation 16, or the like. Pressure in the formation 16 is maintained by gas in the injection zone 30 and, accordingly, it is desirable in such fields to maintain the pressure in the injection zone as hydrocarbon fluids are produced from the formation 16 by injecting gas. The formation pressure may be maintained by water injection, gas injection, or both. The injection of gas requires the removal of the liquids from the gas prior to compressing the gas, and injecting the gas back into the injection zone 30. Typically, the GOR of oil and gas mixtures recovered from such formations increases as the level of the oil bearing zone drops as a result of the removal of oil from the oil bearing formation 16.
In the well 10, a packer 34 or a nipple with a locking mandrel or the like is used to prevent the flow of fluids in the annular space between the third casing section 22 and the fourth casing section 24. A packer 36 is positioned to prevent the flow of fluids in the annular space between the exterior of the production tubing 26 and the interior of the second casing section 20 and that portion of the interior of the third casing section 22 above the packer 36. Fluids from the formation 16 can thus flow upwardly through the production tubing 26 and the wellhead 28 to processing equipment (not shown) at the surface, as described previously. The well 10, as shown, produce fluids under the formation pressure and does not require a pump.
Also shown in FIG. 1 is an injection well 40 comprising a first casing section 42, a second casing section 44, a third casing section 46, and an injection tubing 48. A packer 50 is positioned between the interior of the casing 44 and the exterior of the tubing 48 to prevent the upward flow of fluid between the tubing 48 and the casing 44. Gas is injected into the injection zone 30 through perforations 52 in the third casing section 46. The flow of gases into the well 40 is regulated by a wellhead 53 shown schematically as a valve.
In operation, gas produced from the well 10 is injected into the injection zone 30 through the injection well 40. The injected gas thereby maintains pressure in the formation 16 and remains available for production and use as a fuel or other resource at a later date if desired.
In oil wells which produce excessive amounts of gas, the necessity for handling the large volume of gas at the surface can limit the ability of the formation to produce oil. The installation of sufficient gas handling equipment to separate the large volume of gas from the oil filter use as a product, or for injection into the injection zone 30 can be prohibitively expensive.
In FIG. 2, an embodiment of a downhole portion of the present invention is shown which permits the downhole separation and injection of at least a portion of the produced gas, and which permits the production of an oil-enriched mixture of oil and gas. An embodiment of a surface portion of the present invention, which surface portion is complementary to the downhole portion, is described below with respect to FIGS. 6-10 in which surface facilities compress gas separated in the downhole portion of the present invention before the gas is injected using the downhole portion.
The embodiment shown in FIG. 2 comprises a modification of the production oil well 10 in which a perforated or punched orifice, opening, or hole, such as the hole 60, is formed in the production tubing 26 in a manner well known to those skilled in the art. The hole 60 may optionally include a valve (not shown), such as a gas lift valve, a check valve, a hole insert, or the like, positioned therein for controlling the flow of fluids therethrough. A downhole separator 70 is positioned within the production tubing 26 so that a gas discharge outlet (not shown) on the separator is aligned with the hole 60 for discharge therethrough. The separator 70 may be any of a number of different types of separators, such as an auger separator, a cyclone separator, a rotary centrifugal separator, or the like. Auger separators and the positioning of them in production tubing are more fully disclosed and discussed in U.S. Pat. No. 5,431,228, "Down Hole Gas Liquid Separator for Wells", issued Jul. 11, 1995 to Jean S. Weingarten et al, and in "New Design for Compact-Liquid Gas Partial Separation: Down Hole and Surface Installations for Artificial Lift Applications", lean S. Weingarten et al, SPE 30637 presented Oct. 22-25, 1995, both of which references are hereby incorporated in their entirety by reference. Such separators and the positioning of them downhole are considered to be well known to those skilled in the art and are effective to separate at least a major portion of the gas from a flowing stream of liquid (e.g., oil) and gas by causing the fluid mixture to flow around a circular path thereby forcing heavier phases, i.e., the liquids, outwardly by centrifugal force and upwardly into the production tubing 26 for recovery at the surface 12. The lighter phases of the mixture, i.e., the gases, are displaced inwardly within the separator 70, away from the heavier phases, and are thereby separated from the liquids, and flow from the separator 70 through the separator gas outlet, the hole 60, and upwardly through an annulus 72, formed between the second casing section 20 and the production tubing 26, to the surface 12
As shown schematically in FIG. 2, an oil-enriched mixture line 80 and a gas line 82 are connected for providing fluid communication between the wellhead 28 and the annulus 72, respectively, and surface facilities configured for compressing the gas as will be described more fully below with respect to FIGS. 6-10. A gas return line 84 is connected for providing fluid communication between a discharge outlet of surface facilities and the injection tubing 48.
In the operation of the system shown in FIG. 2, a mixture of oil and gas (which may also include other liquids, such as water) flows from the oil-bearing formation 32 through the fourth and third casing sections 24 and 22, respectively, into the production tubing 26, and into the separator 70, as shown schematically by arrows 90. The separator 70 separates at least a portion of the gas from the mixture of oil and gas in the oil well 10 to produce a separated gas and an oil-enriched mixture. As shown schematically by arrows 92, the oil-enriched mixture produced by the separator 70 is discharged upwardly into the production tubing 26 and through the wellhead 28 and the oil-enriched mixture line 80 to surface facilities described below. As shown schematically by an arrow 94, the separated gas is discharged from the separator 70 through the hole 60 into the annulus 72. The separated gas then flows upwardly through the annulus 72 and the gas line 82 to surface facilities, described below, which compress the gas to a pressure sufficient to permit the gas to be injected into the injection zone 30, such pressure being referred to hereinafter as an "injection pressure". The gas compressed to the injection pressure by the surface facilities is discharged from the surface facilities through the gas return line 84 into the injection tubing 48 in the well 40, as shown schematically by an arrow 96, and into the injection zone 30. As a result of head pressure and friction losses which are incurred as the gas is injected downhole, the foregoing injection pressure preferably exceeds the pressure of the gas in the injection zone 30, less the head pressure of the gas in the injection tubing 48, plus pressure loss incurred from friction as the gas is injected downhole.
While only one well 10 is depicted in FIG. 2, a plurality of wells similar to the well 10 may produce gas which is compressed by surface facilities and injected through the dedicated injection well 40 into the injection zone 30.
In an alternate embodiment of the system shown in FIG. 2, the separator 70 may be provided with a cross-over device (not shown), well known to those skilled in the art, to direct separated gas from the separator to the production tubing 26 rather than the annulus 72, and to direct the oil-enriched mixture from the separator to the annulus 72 rather than the production tubing 26. The oil-enriched mixture line 80 would then be connected in fluid communication with the annulus 72 rather than the production tubing 26, and the gas line 82 would be connected in fluid communication with the production tubing 26 rather than the annulus 72. Operation of such an alternate embodiment would otherwise be substantially similar to the operation of the embodiment shown in FIG. 2.
By the use of the system shown in FIG. 2, a portion of the gas is separated downhole from the oil/gas mixture and, as a result, the separated gas incurs less head loss and less friction loss and, therefore, maintains a substantially higher pressure as it is produced to the surface, than it would if it were produced in combination with the oil/gas mixture. The downhole separation of the gas from the oil/gas mixture also relieves the load on surface facilities to separate gas from the oil/gas mixture. In many fields, it is not uncommon to encounter GOR values as high as 10,000 SCF/STB. GOR values from 800 to 2,500 SCF/STB are generally more than sufficient to carry the produced liquids to the surface. A significant amount of the gas can thus be separated downhole with no detriment to the production process. This significantly increases the amount of oil which can be recovered from formations which produce gas and oil in mixture which are limited by the amount of gas handling capacity available at the surface. Additionally, the system of FIG. 2 facilitates the measurement of the gas separation efficiency and of the composition of gas injected downhole.
In FIG. 3, an alternate embodiment of the system of FIG. 2 is shown. An additional hole 62, similar to the hole 60, is perforated, punched, or otherwise formed in the production tubing below the separator 70 and a valve (not shown), such as a gas lift valve, a check valve, a hole insert, or the like, is positioned therein for controlling the flow of fluids therethrough in a manner well known in the art. A tubing tail extension 100 is set in a lower end 26a of the production tubing 26. A packer 102 is positioned between the tubing tail extension 100 and the production tubing 26 to prevent fluid communication therebetween, and a packer 104 is interposed between the tubing tail extension 100 and the third casing section 22 to prevent fluid communication therebetween. A confined annular space 106 is thus defined between the tubing tail extension 100 and the third casing section 22 and between the packers 36, 102, and 104. The third casing section 22 is perforated with perforations 108 to provide fluid communication between the injection zone 30 and the annular space 106. The tubing tail extension 100 is fitted with a first check valve 110 suitably positioned to permit fluid to flow only from the tubing tail extension 100 to the annular space 106 and, therefore, to prevent contra flow. The tubing tail extension 100 is fitted with a second check valve 112 suitably positioned to permit fluid to flow only from that portion of the third casing 22 below the packer 104 to the tubing tail extension 100 and, therefore, to prevent contra flow. The positioning of the tubing tail extension 100, the packers 102 and 104, and the check valves 110 and 112 is considered to be well known to those skilled in the art and therefore will not be discussed further.
As further shown in FIG. 3, in place of the well 40 (FIG. 2) is a well 10' which is substantially identical to the well 10, except for its location in the formation 16. All components of the well 10' are identified by the same reference numerals as the components of the well 10, except that the reference numerals for the well 10' are primed. Because of the substantial similarity of the wells 10 and 10', no further discussion of the well 10' is considered necessary. It is noted though that the gas return line 84 is connected in fluid communication with the annulus 72' of the well 10'.
In the operation of the system shown in FIG. 3, in which the well 10 is operable as a production well and the well 10' is operable as an injection well, a mixture of oil and gas flows from the oil-bearing formation 32 through fourth and third casing sections 24 and 22, respectively, through the second check valve 112 and the tubing tail extension 100, into the production tubing 26, and into the separator 70, as shown schematically by the arrows 90. The valve positioned in the hole 62 prevents the mixture of oil and gas from flowing through the hole 62 into the annulus 72. The separator 70 separates at least a portion of the gas from the mixture of oil and gas in the oil well to produce a separated gas and an oil-enriched mixture. As shown schematically by the arrows 92, the oil-enriched mixture produced by the separator 70 is discharged upwardly into the production tubing 26 and through the wellhead 28 and the oil-enriched mixture line 80 to the surface facilities described below. As shown schematically by the arrow 94, separated gas is discharged from the separator 70 through the hole 60 into the annulus 72. The separated gas then flows upwardly through the annulus 72 and the gas line 82 to surface facilities which compress the gas to the injection pressure, defined above. As shown schematically by the arrow 96, compressed gas is discharged from the surface facilities through the gas return line 84 into the annulus 72' of the well 10' and through the hole 62' into the production tubing 26'. The gas in the production tubing 26' flows through the tubing tail extension 100', the check valve 110', and into the injection zone 30; and the check valve 112' prevents the flow of the gas into the oil-bearing formation 32.
While only one well 10 and only one well 10' is depicted in FIG. 3, one or more wells similar to the well 10 may produce gas which is compressed by surface facilities and injected through one or more wells similar to the injection well 10' into the injection zone 30. Furthermore, wells may alternately be used as production wells and, during their production off-cycles, as injection wells. For example, the well 10 shown in FIG. 3 may be used as an injection well during its production off-cycle while the well 10' is used as a production well which produces gas which is injected into the well 10.
In an alternate embodiment of the system shown in FIG. 3, the separators 70 and 70' may be provided with a cross-over device (not shown), well known to those skilled in the art, to direct separated gas from the separator to the production tubing 26 or 26' rather than the annulus 72 or 72', and to direct the oil-enriched mixture from the separator to the annulus 72 or 72' rather than the production tubing 26 or 26'. The oil-enriched mixture line 80 would then be connected in fluid communication with the annulus 72 rather than the production tubing 26, and the gas line 82 would be connected in fluid communication with the production tubing 26 rather than the annulus 72. Operation of such an alternate embodiment would otherwise be substantially similar to the operation of the embodiment shown in FIG. 3.
By the use of the system shown in FIG. 3, not only is a portion of the gas separated downhole from the oil/gas mixture, and the gas pressure thereby substantially maintained, and the measurement of the separation efficiency and injection gas composition facilitated as with the system of FIG. 2 but, additionally, the system of FIG. 3 does not require a dedicated injection well to inject gas downhole. The system of FIG. 3 permits production wells to be utilized more efficiently since they may be used as injection wells during their production offcycle.
In FIG. 4, a modified portion of an alternate embodiment of the system of FIG. 2 is shown. The separator 70 is positioned in a tubular member 120 positioned in a lower end 26a of the production tubing 26. The positioning of tubular members by wire line operations or coiled tubing is well known to those skilled in the art and will not be discussed. A packer 122 or a nipple with a locking mandrel or the like is positioned above the hole 60, and between an upper end 120a of the tubular member 120 and the production tubing 26 to control the flow of fluids through a "straddle-by-tubing" annulus 124 defined between the tubular member 120 and that portion of the production tubing 26 extending below the packer 122. A packer 126 is positioned below the packers 36 and 122 between a lower end 120b of the tubular member 120 and the third casing section 22 to control the flow of fluids in a confined annular space 128 defined between the tubular member 120 and the third casing section 22 and between the packers 36, 122, and 126. The third casing section 22 is perforated with perforations 130 to provide fluid communication between the injection zone 30 and the annular space 128. A coiled tubing 132 is positioned in this production tubing 26 for providing fluid communication between a gas outlet 70a of the separator 70 and a gas line 82 to surface facilities described below. A "coil-by-tubing" annulus 134 defined between the production tubing 26 and the coiled tubing 132 provides fluid communication between an oil-enriched mixture outlet 70b of the separator 70 and the oil-enriched mixture line 80 to surface facilities. The gas return line 84 is connected in fluid communication between the surface facilities and the annulus 72 (referred to, with respect to FIG. 4, as a "tubing-by-casing" annulus) for carrying to the annulus 72 compressed gas for injection into the formation 16.
In the operation of the system shown in FIG. 4, a mixture of oil and gas flows from the oil-bearing formation 32 through the fourth and third casing sections 24 and 22 (FIG. 2), respectively, into the tubular member 120 and into the separator 70, as shown schematically by the arrows 90. The separator 70 separates at least a portion of the gas from the mixture of oil and gas in the oil well to produce a separated gas and an oil-enriched mixture. As shown schematically by the arrows 92, the oil-enriched mixture produced by the separator 70 is discharged upwardly through the outlet 70b, the coil-by-lubing annulus 134, the wellhead 28 (FIG. 2), and the oil-enriched mixture line 80 to surface facilities described below. As shown schematically by the arrow 94, the separated gas produced by the separator 70 is discharged upwardly through the gas outlet 70a, the coiled tubing 132, the gas line 82, and to surface facilities which compresses the gas to the injection pressure, defined above. Compressed gas is discharged from the surface facilities through the gas return line 84 into the tubing-by-casing annulus 72. As shown schematically by the arrow 96, compressed gas in the tubing-by-casing annulus 72 is ported through the hole 60 into and through the straddle-by-tubing annulus 124, the annular space 128, the perforations 130, and into the injection zone 30.
In an alternate embodiment of the system shown in FIG. 4, the separator 70 may be provided with a cross-over device (not shown), well known to those skilled in the art, to direct separated gas from the separator to the annulus 134 rather than the tubing 132, and to direct the oil-enriched mixture from the separator to the tubing 132 rather than the annulus 134. The oil-enriched mixture line 80 would then be connected in fluid communication with the tubing 132 rather than the annulus 134, and the gas line 82 would be connected in fluid communication to the annulus 134 rather than the tubing 132. Operation of such an alternate embodiment would otherwise be substantially similar to the operation of the embodiment shown in FIG. 4.
In a further alternate embodiment of the system shown in FIG. 4, the system may be configured without the tubular member 120, the packers 122 and 126, and the hole 60 by replacing the packer 126 with the packer 36 and extending the production tubing 26 to and through the packer 36. Operation of such an alternate embodiment is substantially similar to the operation of the embodiment shown in FIG. 4, except that the mixture of oil and gas flows through the production tubing 26 without flowing through the tubular member 120, and compressed gas flows through the annulus 72 to the injection zone 30 without flowing through the hole 60 and through the annulus 124.
By the use of the system shown in FIG. 4, not only is a portion of the gas separated downhole from the oil/gas mixture, and the gas pressure maintained, and the measurement of the separation efficiency and injection gas composition facilitated as with the system of FIG. 2 but, additionally, the system of FIG. 4 does not require an additional well to inject gas downhole and, thus, does not require a significant quantity of piping and valves at the surface to interconnect various wells.
In FIG. 5, an alternate embodiment of the system of FIG. 4 is shown in which the separator 70 is positioned at the surface 12. Because there is no downhole separation of the gas from the oil and gas produced, no coiled tubing is run down the production tubing 26 as there was in the system of FIG. 4. The system shown in FIG. 5 is otherwise substantially similar to the system shown in FIG. 4.
Operation of the system of FIG. 5 is similar to the operation of the system of FIG. 4 except that oil and gas produced from the formation 16 is separated by the separator 70 positioned at the surface 12. Thus the arrows 90 represent the flow of a mixture of oil and gas from the oil-bearing formation 32 through fourth and third casing sections 24 and 22, respectively, through the tubular member 120 and the production tubing 26, and into the separator 70 located at the surface 12. The separator 70 separates at least a portion of the gas from the mixture of oil and gas in the oil well to produce a separated gas an an oil-enriched mixture. The oil-enriched mixture produced by the separator 70 is discharged through the outlet 70b into the oil-enriched mixture line 80 to surface facilities described below. Separated gas produced by the separator 70 is discharged through the gas outlet 70a and the gas line 82 to surface facilities which compress the gas to the injection pressure, defined above. Compressed gas is discharged from the surface facilities through the gas return line 84 into the annulus 72. As shown schematically by the arrow 96, compressed gas in the annulus 72 is ported through the hole 60 into and through the annulus 124, the annular space 128, the perforations 130, and into the injection zone 30.
In an alternate embodiment of the system shown in FIG. 5, the system may be configured without the tubular member 120, the packers 122 and 126, and the hole 60 by replacing the packer 126 with the packer 36 and extending the production tubing 26 to and through the packer 36. Operation of such an alternate embodiment is substantially similar to the operation of the embodiment shown in FIG. 5, except that the mixture of oil and gas flows through the production tubing 26 without flowing through the tubular member 120, and compressed gas flows through the annulus 72 to the injection zone 30 without flowing through the hole 60 and through the annulus 124.
By the use of the system shown in FIG. 5, the separator 70 is more accessible than it was in the foregoing systems described, no coiled tubing is required, and the well 10 permits wireline tools to pass therethrough. As with the foregoing systems, the separation efficiency and injection gas composition may be measured. Furthermore, an additional well is not required to inject gas downhole. Thus, a significant quantity of piping and valves is not required at the surface to interconnect various wells.
In FIGS. 6-10, five embodiments of a surface portion of the present invention are shown in which gas, after it has been separated and before it is injected downhole, is compressed using surface facilities referenced in the foregoing discussion of embodiments of the downhole portion of the present invention shown in FIGS. 2-5. As stated previously, the surface portion of the present invention is complementary to the downhole portion and, in the following discussion, the embodiments of the surface portion are to be understood as connected through the oil-enriched mixture line 80, the gas line 82, and the gas return line 84 to any one of the embodiments of the downhole portion described with respect to FIGS. 2-5.
The embodiment of the surface portion of the present invention shown in FIG. 6 comprises a suitable compressor 200 drivingly connected through a shaft 202 to a suitable turbine 204. The compressor 200 is connected to the gas line 82 for receiving gas therethrough, and to the gas return line 84 for discharging gas thereto. The compressor 200 may be an axial, radial, or mixed-flow compressor, or the like, configured for compressing gas received through the gas line 82 to the injection pressure, defined above, and for discharging compressed gas to the gas return line 84. Compressors such as the compressor 200 are considered to be well known to those skilled in the art and will not be discussed further.
The turbine 204 is connected in parallel with the oil-enriched mixture line 80 for receiving through a line 80a, and for being driven by, at least a portion of the oil-enriched mixture flowing through the oil-enriched mixture line 80, and for discharging the received mixture through a line 80b to the oil-enriched mixture line 80. A suitable valve 206 is positioned in the oil-enriched mixture line 80 between the line 80a and 80b for controlling the amount of the oil-enriched mixture which flows through the turbine 204. The turbine 204 may be a radial or axial turbine such as a turbine expander, a hydraulic turbine, a bi-phase turbine, or the like. Turbine expanders, hydraulic turbines, and bi-phase turbines are considered to be well known to those skilled in the art, and are effective for receiving a stream of fluids, such as the oil-enriched mixture in the present invention, and for generating, from the received stream of fluids, torque exerted onto a shaft, such as the shaft 202, such stream of fluids comprising largely gases, liquids, and mixtures of gases and liquids, respectively. Bi-phase turbines, in particular, are more fully disclosed and discussed in U.S. Pat. No. 5,385,446, entitled "Hybrid Two-Phase Turbine", issued Jan. 31, 1995, to Lance G. Hays, which reference is hereby incorporated in its entirety by reference.
In the operation of the system shown in FIG. 6, if the valve 206 is open, then the oil-enriched mixture flows through the oil-enriched mixture line 80, generally bypassing the turbine 204, to a pipeline (not shown) which carries the mixture to downstream processing facilities (not shown) which are considered to be well known in the art and will not be discussed. When the turbine 204 is bypassed by the oil-enriched mixture as a result of the valve 206 being open, the turbine 204 does not drive the compressor 200 and gas in the gas line 82 is not compressed and cannot be injected into the formation 16 (not shown). If the valve 206 is closed, then all of the oil-enriched mixture flowing through the oil-enriched mixture line 80 also flows through the line 80a to and through the turbine 204, and through the line 80b to the pipeline (not shown) which carries the mixture to downstream processing facilities. As the mixture flows through the turbine 204, rotational motion is imparted to the turbine which then imparts rotational motion to the shaft 202 and drives the compressor 200. The compressor 200 receives gas through the gas line 82 and, as the compressor rotates, it compresses the gas received from the line 82 to the injection pressure, defined above. Compressed gas is discharged from the compressor 200 into the gas return line 84 and into the injection zone 30 (FIGS. 2-5) as discussed above. The valve 206 may be only partially closed to direct only a portion of the oil-enriched mixture to the turbine 204 in which case, the pressure imparted by the compressor 200 to gas received through the gas line 82 will be related to the amount that the valve 206 is closed. Preferably, the valve 206 is closed only enough to permit the compressor 200 to sufficiently compress gas for injection into the formation, and to thereby conserve pressure in the mixture in the oil-enriched mixture line 80.
By the use of the foregoing system shown in FIG. 6, formation pressure may be used to inexpensively compress gas at a well and inject the gas downhole without the necessity of sending the gas to a central compressor plant.
In FIG. 7, an alternate embodiment of the system of FIG. 6 is shown in which the turbine 204 is driven by at least a portion of the gas taken off of the gas line 82 rather than at least a portion of the oil-enriched mixture taken off of the oil-enriched mixture line 80. To that end, a line 82a is connected for providing fluid communication between the gas line 82 and an inlet (not shown) to the turbine 204. A valve 210 is positioned in the gas line 82 downstream of the line 82a take-off for controlling the distribution of gas flow between the compressor 200 and the turbine 204. The line 80b is connected for providing fluid communication between an outlet (not shown) of the turbine 204 and the oil-enriched mixture line 80.
In the operation of the system shown in FIG. 7, the oil-enriched mixture flows through the oil-enriched mixture line 80 directly to a pipeline (not shown) which carries the mixture to downstream processing facilities which are considered to be well known in the art and will not be discussed. The valve 210 is actuated to regulate the flow of gas delivered from the gas line 82 to the turbine 204 and to the compressor 200 so that a proper flow balance may be maintained to permit the turbine to generate the power required to drive the compressor, thus controlling the operation thereof. Therefore, proper operation of the system of FIG. 7 requires that the valve 210 be neither fully open nor fully closed but rather that it be only partially open so that a portion of the gas in the gas line 82 be directed to the compressor 200 and a portion be directed through the line 82a to the turbine 204. Gas that does not flow through the valve 210 drives the turbine 204 which drives the compressor 200, and gas that flows through the valve 210 is compressed by the compressor 200. The proportion of gas that flows through the turbine 204 is preferably optimized to permit the turbine 204 to drive the compressor 200 to compress gas that flows through the valve 210 to the injection pressure, defined above. Gas is discharged from the turbine 204 through the line 80b to the oil-enriched mixture line 80 and to the pipeline and downstream processing facilities (not shown); and compressed gas is discharged from the compressor 200 into the gas return line 84 and into the injection zone 30 (FIGS. 2-5) as discussed above.
In FIG. 8, an alternate embodiment of the system of FIG. 6 is shown. The gas line 82 is connected for carrying gas to a separator 220, such as a suction scrubber or the like, configured for producing a separated gas and a separated liquid from the gas received through the gas line 82. A line 222 is connected to the separator 220 for carrying the separated gas produced by the separator 220 to the compressor 200, and a line 224 is connected to the separator 220 for carrying separated liquids produced by the separator 220 to a line 226, a line 228, and to a pipeline (not shown). A line 230 carries a portion of the gas in the line 222 to a heater such as a gas fired furnace 232 for combustion therein. While not shown, it is understood that suitable valves and the like are provided on the lines 222 and 230 for controlling gas flow distribution through those lines in a manner well known to those skilled in the art. A line 234 is connected for carrying compressed gas discharged from the compressor 200 to a gas-to-gas heat exchanger 236, and the gas return line 84 is connected for carrying the compressed gas from the heat exchanger 236 to an injection well as discussed above.
The oil-enriched mixture line 80 is connected for carrying the oil-enriched mixture to a separator 240, such as an expander suction separator or the like, configured for producing a separated gas and a separated liquid from the oil-enriched mixture received through the oil-enriched mixture line 80. A line 242 is connected to the separator 240 for carrying the separated gas produced by the separator 240 to the heat exchanger 236, and a line 226 is connected to the separator 240 for carrying separated liquids produced by the separator 240 to the line 228, and to the pipeline (not shown). A line 244 is connected to the heat exchanger 236 for carrying the separated gas produced by the separator 240 from the heat exchanger 236 to the furnace 232 for heating therein. A line 246 is connected for carrying the separated gas produced by the separator 240 and heated in the furnace 232 to an inlet (not shown) of the turbine 204. The line 228 is connected for carrying gas from the turbine 204 to the pipeline (not shown).
In the operation of the system shown in FIG. 8, the oil-enriched mixture flows through the oil-enriched mixture line 80 to the separator 240 which produces a separated gas and a separated liquid. The separated liquids (i.e., oil-enriched mixture) flow through the lines 226 and 228 to the pipeline and downstream processing facilities. The separated gas produced by the separator 240 flows through the line 242 to the heat exchanger 236, which transfers heat to the separated gas, through the line 244 to the furnace 232, which further heats the separated gas, and through the line 246 to the turbine 204. The heated gas drives the turbine 204, which then drives the compressor 200, and the gas is then discharged from the turbine through the line 228 to the pipeline (not shown). The heat transferred through the heat exchanger 236 and by the heater 232 to the gas that drives the turbine 204 should be sufficient to maintain a temperature of that gas, as it is discharged from the turbine, which is high enough to prevent paraffin's and/or hydrates from forming in the gas.
Gas in the gas line 82 flows to the separator 220 which produces from the gas separated gas and separated liquids. The separated liquids produced by the separator 220 flow through the lines 224, 226, and 228 to the pipeline (not shown) and to downstream processing facilities. A portion of the separated gas produced by the separator 220 flows through the line 222 to the compressor 200, and another portion of the separated gas flows through the lines 222 and 230 to the furnace 232. The gas carried to the furnace through the line 230 is combusted to generate heat to heat the gas which flows from the line 244 to the furnace. The gas carried through the line 222 to the compressor 200 is compressed to the injection pressure, defined above. Compressed gas is then discharged from the compressor 200 through the line 234 to the heat exchanger 236 which transfers heat from the compressed gas carried by the line 234 to the separated gas carried by the line 242. The compressed gas is then carried by the gas return line 84 to an injection well (not shown) for injection into the injection zone 30 (FIGS. 2-5) as discussed above.
While the furnace 232 is depicted as a gas fired furnace, any suitable heater may be used. For example, if electricity is available, an electric heater could also be utilized in lieu of the gas fired heater 232, and thereby conserve fuel gas and permit a greater quantity of gas to be compressed and injected into the injection zone 30 (FIGS. 2-5).
In FIG. 9, an alternate embodiment of the system of FIG. 8 is shown wherein the compressor 200 is a first stage compressor. The line 234 (FIG. 8) is depicted in FIG. 9 as two lines 234a and 234b, and a suitable second stage compressor 250 is interposed between the lines 234a and 234b to further compress gas discharged from the compressor 200 before the gas is passed through the heat exchanger 236 and to the gas return line 84. The second stage compressor 250 is driven by any available suitable power source 252, such as an electrically powered motor, a gas fired turbine, a diesel engine, a turbine driven by fluids taken from available high pressure/output flowlines, or the like. Because the compressor 250 adds heat to the compressed gas, which heat is transferred via the heat exchanger 236 to the gas carried to the turbine 204, the furnace 232 utilized in the system of FIG. 8 is not utilized in the system of FIG. 9.
In the operation of the system shown in FIG. 9, the oil-enriched mixture flows through the oil-enriched mixture line 80 to the separator 240 which produces a separated gas and a separated liquid. The separated liquids (i.e., oil-enriched mixture) flow through the lines 226 and 228 to the pipeline and downstream processing facilities. The separated gas produced by the separator 240 flows through the line 242 to the heat exchanger 236, which transfers heat to the separated gas, and through the line 246 to the turbine 204. The heated gas drives the turbine 204, which then drives the compressor 200, and the gas is then discharged from the turbine through the line 228 to the pipeline (not shown). The heat transferred from the heat exchanger 236 to the gas that drives the turbine 204 should be sufficient to maintain a temperature of that gas, as it is discharged from the turbine, which is high enough to prevent paraffin's and/or hydrates from forming in the gas.
Gas in the gas line 82 flows to the separator 220 which produces from the gas separated gas and separated liquids. The separated liquids produced by the separator 220 flow through the lines 224, 226, and 228 to the pipeline and to downstream processing facilities (not shown). The separated gas produced by the separator 220 flows through the line 222 to the compressor 200, and through the line 234a to the second stage compressor 250. The compressors 200 and 250 compress the gas to the injection pressure, defined above, and, as a consequence of the compression, the gas is also heated. The second stage compressor 250 discharges the compressed and heated gas through the line 234b to the heat exchanger 236 which transfers heat from the compressed and heated gas to the separated gas produced by the separator 240. The compressed gas is then carried from the heat exchanger 236 by the gas return line 84 to an injection well (not shown) for injection into the injection zone 30 (FIGS. 2-5) as discussed above.
In FIG. 10, an alternate embodiment of the system of FIG. 9 is shown in which a different separation technique is used. To that end, the oil-enriched mixture line 80 is connected directly to the pipeline (not shown) for carrying the oil-enriched mixture to downstream processing facilities (not shown). The gas line 82 is connected for carrying separated gas, directly to the heat exchanger 236, and the line 246 is connected for carrying the separated gas discharged from the heat exchanger to the inlet (not shown) of the turbine 204. The outlet (not shown) of the turbine 204 is connected through a line 254 for carrying gas discharged from the turbine to a separator 256, such as an auger separator, a cyclone separator, a rotary centrifugal separator, or the like, similar to the separator 70 described above with respect to FIGS. 2-5. The separator 256 is configured for separating at least a portion of the gas from the mixture of gas and liquids discharged from the turbine 204 to produce a separated gas to a line 258 and a separated mixture of liquids and gas to a line 260. The line 258 is connected for carrying the separated gas produced by the separator 256 to an inlet (not shown) of the compressor 200, and the line 260 is connected for carrying the separated mixture of liquids and gas produced by the separator 256 to the oil-enriched mixture line 80 for transport to the pipeline (not shown).
In the operation of the system shown in FIG. 10, the oil-enriched mixture flows through the oil-enriched mixture line 80 to the pipeline (not shown) which carries the mixture to downstream facilities for further processing. Separated gas is carried through the gas line 82 to the heat exchanger 236, which transfers heat to the separated gas, and through the line 246 to the turbine 204. The heated separated gas drives the turbine 204, which then drives the compressor 200, and the gas, with some condensate liquids, is then discharged from the turbine through the line 254 to the separator 256. The separator 256 separates at least a portion of the gas from the mixture of gas and liquids discharged from the turbine 204 to produce a separated gas to the line 258 and a separated mixture of liquids and gas to the line 260. The separated mixture of gas and liquids produced by the separator 256 is carried through the line 260 to the oil-enriched mixture line 80 which transports the mixture with the oil-enriched mixture to the pipeline and downstream processing equipment (not shown). The separated gas produced by the separator 256 is carried through the line 258 to and through the compressor 200, and through the line 234a to and through the second stage compressor 250. The compressors 200 and 250 are driven by the turbine 204 and the power source 252, respectively, to compress the gas to the injection pressure, defined above, and, as a consequence of the compression, the gas is also heated. The compressor 250 discharges the compressed and heated gas through the line 234b to the heat exchanger 236 which transfers heat from the compressed and heated gas to the separated gas carried by the gas line 82. The heat transferred through the heat exchanger 236 to the separated gas, carried by the gas line 82 and discharged from the heat exchanger to the line 246 to drive the turbine 204, should be sufficient to maintain a temperature of that gas, as it is discharged from the turbine, which is high enough to prevent paraffin's and/or hydrates from forming in the gas. The compressed gas is then carried from the heat exchanger 236 by the gas return line 84 to an injection well (not shown) for injection into the injection zone 30 (FIGS. 2-5) as discussed above.
In an alternate embodiment of the system shown in FIG. 10, the system may be configured without the second stage compressor 250 and the accompanying power source 252, and the lines 234a and 234b may be coupled to carry compressed gas from the compressor 200 to the heat exchanger 236. Operation of such an alternate embodiment would otherwise be substantially similar to the operation of the embodiment shown in FIG. 10.
The investment to install the system of the present invention in a plurality of wells to reduce the gas produced from a field is substantially less than the cost of providing additional separation and compression equipment at the surface. It also requires no fuel gas to drive the compression equipment since the pressure or combustion of the flowing fluids can be used for this purpose. It also permits the injection of selected quantities of gas from individual wells into a downhole injection zone, such as a gas cap, from which wells oil production had become limited by reason of the capacity of the lines or tubing to carry produced fluids away from the well, thereby permitting increased production from such wells. It can also make certain formations, which had previously been uneconomical to produce from, economical to produce from because of the ability to inject the gas downhole.
Having thus described the present invention by reference to certain of its preferred embodiments, it is noted that the embodiments disclosed are illustrative rather than limiting in nature and that many variations and modifications are possible within the scope of the present invention. Many such variations and modifications may be considered obvious and desirable by those skilled in the art based upon a review of the foregoing description of preferred embodiments.
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A method and system for increasing oil production from an oil well producing a mixture of oil and gas at an elevated pressure through a wellbore penetrating an oil-bearing formation containing an oil-bearing zone and an injection zone, by separating at least a portion of the gas from the mixture of oil and gas to produce a separated gas and an oil-enriched mixture; utilizing energy from at least a portion of the mixture of oil and gas to compress at a surface at least a portion of the separated gas to produce a compressed gas having sufficient pressure to be injected into the injection zone; injecting the compressed gas into the injection zone; and recovering at least a major portion of the oil-enriched mixture.
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RELATED APPLICATION
[0001] This application claims the benefit of co-pending U.S. Provisional Patent Application Serial No. 61/450,990, filed 9 Mar. 2011.
BACKGROUND OF THE INVENTION
[0002] The invention disclosed herein relates to apparatus and methods for waste reduction and improvements to the quality and production in web processing operations, such as diaper manufacturing. While the description provided relates to diaper manufacturing, the apparatus and method are easily adaptable to other applications.
[0003] Generally, diapers comprise an absorbent insert or patch and a chassis, which, when the diaper is worn, supports the insert proximate a wearer's body. Additionally, diapers may include other various patches, such as tape tab patches, reusable fasteners and the like. The raw materials used in forming a representative insert are typically cellulose pulp, tissue paper, poly, nonwoven web, acquisition, and elastic, although application specific materials are sometimes utilized. Usually, most of the insert raw materials are provided in roll form, and unwound and applied in assembly line fashion.
[0004] One such layer, the acquisition layer, is used to more evenly distribute liquid insults to disposable products. In modern disposable products, super absorbent polymers (SAP) are used to store liquid. SAP is generally excellent at liquid storage, but because SAP turns to a gelatinous type material, does not distribute liquid well. Therefore, an acquisition layer plays a key role in dispersing liquids away from the point of deposit, in order to increase the overall liquid storage capacity of the SAP. Because the acquisition layer performs better when oriented properly, it is important that the layer be deposited into the disposable product uniformly and correctly oriented.
[0005] In the creation of a diaper, multiple roll-fed web processes are typically utilized. To create an absorbent insert, the cellulose pulp is unwound from the provided raw material roll and pulverized by a pulp mill. Discrete pulp cores are formed by a core forming assembly and placed on a continuous tissue web. Optionally, super-absorbent powder may be added to the pulp core. The tissue web is wrapped around the pulp core. The wrapped core is debulked by proceeding through a calendar unit, which at least partially compresses the core, thereby increasing its density and structural integrity. After debulking, the tissue-wrapped core is passed through a segregation or knife unit, where individual wrapped cores are cut. The cut cores are conveyed, at the proper pitch, or spacing, to a boundary compression unit.
[0006] While the insert cores are being formed, other insert components are being prepared to be presented to the boundary compression unit. For instance, the poly sheet is prepared to receive a cut core. Like the cellulose pulp, poly sheet material is usually provided in roll form. The poly sheet is fed through a splicer and accumulator, coated with an adhesive in a predetermined pattern, and then presented to the boundary compression unit. In addition to the poly sheet, which may form the bottom of the insert, a two-ply top sheet may also be formed in parallel to the core formation. Representative plies are an acquisition web material and a nonwoven web material, both of which are fed from material rolls, through a splicer and accumulator. The plies are coated with adhesive, adhered together, cut to size, and presented to the boundary compression unit. Therefore, at the boundary compression unit, three components are provided for assembly: the poly bottom sheet, the core, and the two-ply top sheet.
[0007] A representative boundary compression unit includes a die roller and a platen roller. When all three insert components are provided to the boundary compression unit, the nip of the rollers properly compresses the boundary of the insert. Thus, provided at the output of the boundary compression unit is a string of interconnected diaper inserts. The diaper inserts are then separated by an insert knife assembly and properly oriented. At this point, the completed insert is ready for placement on a diaper chassis.
[0008] A representative diaper chassis comprises nonwoven web material and support structure. The diaper support structure is generally elastic and may include leg elastic, waistband elastic and belly band elastic. The support structure is usually sandwiched between layers of the nonwoven web material, which is fed from material rolls, through splicers and accumulators. The chassis may also be provided with several patches, besides the absorbent insert. Representative patches include adhesive tape tabs and resealable closures.
[0009] The process utilizes two main carrier webs; a nonwoven web which forms an inner liner web, and an outer web that forms an outwardly facing layer in the finished diaper. In a representative chassis process, the nonwoven web is slit at a slitter station by rotary knives along three lines, thereby forming four webs. One of the lines is on approximately the centerline of the web and the other two lines are parallel to and spaced a short distance from the centerline. The effect of such slicing is twofold; first, to separate the nonwoven web into two inner diaper liners. One liner will become the inside of the front of the diaper, and the second liner will become the inside of the back of that garment. Second, two separate, relatively narrow strips are formed that may be subsequently used to cover and entrap portions of the leg-hole elastics. The strips can be separated physically by an angularly disposed spreader roll and aligned laterally with their downstream target positions on the inner edges of the formed liners.
[0010] After the nonwoven web is sliced, an adhesive is applied to the liners in a predetermined pattern in preparation to receive leg-hole elastic. The leg-hole elastic is applied to the liners and then covered with the narrow strips previously separated from the nonwoven web. Adhesive is applied to the outer web, which is then combined with the assembled inner webs having elastic thereon, thereby forming the diaper chassis. Next, after the elastic members have been sandwiched between the inner and outer webs, an adhesive is applied to the chassis. The chassis is now ready to receive an insert.
[0011] In diapers it is preferable to contain elastics around the leg region in a cuff to contain exudates for securely within the diaper. Typically, strands of elastic are held by a non-woven layer that is folded over itself and contains the elastics within the overlap of the non-woven material. The non-woven is typically folded by use of a plow system which captures the elastics within a pocket, which is then sealed to ensure that the elastics remain in the cuff.
[0012] Most products require some longitudinal folding. It can be combined with elastic strands to make a cuff. It can be used to overwrap a stiff edge to soften the feel of the product. It can also be used to convert the final product into a smaller form to improve the packaging.
[0013] To assemble the final diaper product, the insert must be combined with the chassis. The placement of the insert onto the chassis occurs on a placement drum or at a patch applicator. The inserts are provided to the chassis on the placement drum at a desired pitch or spacing. The generally flat chassis/insert combination is then folded so that the inner webs face each other, and the combination is trimmed. A sealer bonds the webs at appropriate locations prior to individual diapers being cut from the folded and sealed webs.
[0014] Roll-fed web processes typically use splicers and accumulators to assist in providing continuous webs during web processing operations. A first web is fed from a supply wheel (the expiring roll) into the manufacturing process. As the material from the expiring roll is depleted, it is necessary to splice the leading edge of a second web from a standby roll to the first web on the expiring roll in a manner that will not cause interruption of the web supply to a web consuming or utilizing device.
[0015] In a splicing system, a web accumulation dancer system may be employed, in which an accumulator collects a substantial length of the first web. By using an accumulator, the material being fed into the process can continue, yet the trailing end of the material can be stopped or slowed for a short time interval so that it can be spliced to leading edge of the new supply roll. The leading portion of the expiring roll remains supplied continuously to the web-utilizing device. The accumulator continues to feed the web utilization process while the expiring roll is stopped and the new web on a standby roll can be spliced to the end of the expiring roll.
[0016] In this manner, the device has a constant web supply being paid out from the accumulator, while the stopped web material in the accumulator can be spliced to the standby roll. Examples of web accumulators include that disclosed in U.S. patent application Ser. No. 11/110,616, which is commonly owned by the assignee of the present application, and incorporated herein by reference.
[0017] As in many manufacturing operations, waste minimization is a goal in web processing applications, as products having spliced raw materials cannot be sold to consumers. Indeed, due to the rate at which web processing machines run, even minimal waste can cause inefficiencies of scale. In present systems, waste materials are recycled. However, the act of harvesting recyclable materials from defective product is intensive. That is, recyclable materials are harvested only after an identification of a reject product at or near the end of a process. The result is that recyclable materials are commingled, and harvesting requires the extra step of separating waste components. Therefore, the art of web processing would benefit from systems and methods that identify potentially defective product prior to product assembly, thereby eliminating effort during recyclable material harvesting.
[0018] Furthermore, to improve quality and production levels by eliminating some potentially defective product, the art of web processing would benefit from systems and methods that ensure higher product yield and less machine downtime.
[0019] In some applications, narrow webs of material are introduced into the manufacturing process. Narrow webs can get twisted because they can jump rollers in the system. If the narrow webs become twisted, the twist often persists in the form of an undesirable overlap of material. This often has required operators to undesirably stop the machine and manually remove the twist from the web.
SUMMARY OF THE INVENTION
[0020] Provided are method and apparatus for minimizing waste and improving quality and production in web processing operations.
[0021] Importantly, the methods taught in the present application are applicable not only to diapers and the like, but in any web based operation. The waste minimization techniques taught herein can be directed any discrete component of a manufactured article, i.e., the methods taught herein are not product specific. For instance, the present methods can be applied as easily with respect to diaper components as they can for feminine hygiene products, as they can for face masks in which components such as rubber bands and nose pieces are used.
[0022] For instance, by practicing the methods of the present invention, waste of staples and elastic bands can be avoided during manufacture of face masks, for instance those disclosed in U.S. Pat. No. 7,131,442. One of the objectives is simply to recognize product during manufacture that ultimately would fail quality control inspection, and avoid placing material on to that product during the manufacturing processes.
[0023] As another example, the amount of adhesive applied to certain products can be reduced by not applying adhesive to products that have already been determined to be defected or assigned to rejection. For instance, in U.S. Pat. No. 6,521,320, adhesive application is shown for example in FIG. 11 . By assigning or flagging product that has already been determined to end up in a scrap or recycling pile, the adhesive flow can be stopped or minimized.
[0024] In yet another exemplary application of the methods of the present invention, discrete components or raw material carried on products that have already been determined to be defected or assigned to rejection can also be removed and recycled prior to commingling with other discrete components or raw material. For instance, if an absorbent pad, such as shown at reference numeral 40 of U.S. Pat. No. 6,521,320 is destined for application to a product that has already been determined to be defected or assigned to rejection, the absorbent pad can be withdrawn from the product, or never introduced in the first instance. For example, during startup or shutdown of high speed diaper manufacturing operations, a certain number of products is routinely discarded into recycling. By identification of the start up or shut down routine, avoidance of introduction of absorbent pads can be achieved. Alternatively, during stand-by, the absorbent pads often degrade by accumulation of dust. By identifying which products would bear the dust, the absorbent pads can be withdrawn from further manufacture, and no additional components would be applied to such a product.
[0025] In one embodiment, a method for assembling a plurality of continuous webs is provided, including defining first web inspection parameters and inspecting at least one of the plurality of continuous webs to determine whether the at least one web conforms to the first web inspection parameters. Further, the method involves providing a chassis web which is adapted to receive a patch and providing a patch web from which the patch is cut. Finally, the cut patch is applied to the chassis web if the inspected web conforms to the first web inspection parameters. In another embodiment, the method also includes steps of defining first patch inspection parameters and inspecting a cut patch to determine whether the patch conforms to the first patch inspection parameters. While the patch inspection may provide interesting diagnostic information related to a web processing machine, the application of the patch may be limited to those patches that conform to the first patch inspection parameters.
[0026] Another embodiment of the method of the present invention involves defining first web inspection parameters and a product pitch. Generally in any web process, a web is provided, which is traveling at a web velocity. This embodiment involves inspecting the web to determine whether the web conforms to the first web inspection parameters and producing an inspection value as a result of the inspecting step. This value is then recorded once per sample time interval. The sample time interval may be calculated by dividing the defined product pitch by the web velocity. While the inspection value may be as simple as a bivalent value, a more informational multivalent value may be used.
[0027] In addition to the web process provided, an apparatus for carrying out the process is provided. An embodiment of the apparatus includes a continuous web supply providing continuous web material from an upstream position to a downstream position and a means for providing a patch spaced from a first side of the continuous web material. A patch applicator is provided to alter the space between the patch providing means and the continuous web material and a web inspection device is positioned upstream from the patch applicator. Additionally, a programmable controller receives an input from the web inspection device and provides an output to the patch applicator. The web processing apparatus may also include a patch inspection device that provides an output to the programmable controller. A patch reject conveyor may be positioned to receive defective patches from the patch providing means. In another embodiment of a web processing apparatus, a product inspection device may be located downstream from the patch applicator to provide an output to the programmable controller. Also, a product reject conveyor could be adapted to divert defective product as indicated by the product inspection device.
[0028] In another aspect of the invention, twists in narrow webs, such as an acquisition layer, are first recognized and then self corrected, resulting in a scrap reduction. A camera or other type of vision system first detects a twist (or the acquisition layer being deposited in an upside-down manner), and next when a twist is seen, a narrow web turning device flips the web, to get the twist out and return the web to its properly oriented deposit position.
[0029] It appears the apparatus (because of poly air lines) is only able to turn 180 deg. In one direction and then reverse direction back to original position. I believe that the term apparatus is referring to the web inverter, yes it rotates 180 degrees back and forth. The theory is that then we do not wind up the upstream web.
[0030] A web inverter is positioned based on process constraints. Flipping of spooled material occurs most frequently as it is unwound of the roll, and this requires correction by inverting the web to its properly oriented condition. Repeated faults within a predetermined time period could force a shutdown to investigate a potential problem. Twists are detected prior to application with a vision camera. These twists most frequently occur as the spooled material is unwound. It is preferred to look for and detect the correct orientation immediately prior to application of the material onto downstream processes.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] FIG. 1A is a perspective view of a web processing system of the present invention, carrying a web in a properly oriented condition;
[0032] FIG. 1B is a top plan view of the web processing system shown in FIG. 1A , carrying a web in a properly oriented condition;
[0033] FIG. 2A is a perspective view of a web processing system of the present invention shown carrying a web in a twisted condition;
[0034] FIG. 2B is a top plan view of the web processing system shown in FIG. 2A , carrying a web in a twisted condition;
[0035] FIG. 3 is a top view of the web processing system shown initiating a correction sequence;
[0036] FIG. 4 is a perspective view of FIG. 3 , showing the web correction being initiated by imparting a twist to the web;
[0037] FIG. 5 shows the twisted web correction migrating downstream after the web correction sequence has been performed;
[0038] FIG. 6 is a perspective view of the condition shown in FIG. 5 ;
[0039] FIG. 7 shows the twisted web correction continuing to migrate downstream after the web correction sequence has been performed;
[0040] FIG. 8 shows the twisted web correction having been eliminated, and the web returned to its proper orientation, after the web correction sequence has been performed;
[0041] FIG. 9 is a top view of a new twist occurring in the web;
[0042] FIG. 10 is a perspective view of the twist of FIG. 9 ;
[0043] FIG. 11 is a top view of the web correction sequence again being initiated, and the correction traveling downstream;
[0044] FIG. 12 is a perspective view of FIG. 11 ;
[0045] FIG. 13 is a top view of the web correction sequence with web the correction traveling downstream;
[0046] FIG. 14 is a top view of the twisted web correction having been eliminated, and the web returned to its proper orientation, after the web correction sequence has been performed.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0047] Although the disclosure hereof is detailed and exact to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention which may be embodied in other specific structures. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims.
[0048] It is noted that the present waste minimization techniques and apparatus are described herein with respect to products such as diapers, but as previously mentioned, can be applied to a wide variety of processes in which discrete components are applied sequentially.
[0049] Referring now to FIG. 1A , a perspective view of a web processing system 10 of the present invention is shown, carrying a web 12 (such as an acquisition layer) in a properly oriented condition. In its properly oriented condition, side 16 is visible from the top, side 14 is visible from the bottom.
[0050] As seen on FIG. 1A , at vision inspection locations 18 , inspection can take place to determine the presence or absence of acceptable product introduction. In this case, acceptable product introduction would be either that side 16 is visible from the top, and/or that the web 12 is not twisted and remains at its proper web width.
[0051] In addition to visual inspection, operational characteristics such as startup/ramp-up/shutdown operations can trigger waste minimization techniques as will be described later.
[0052] At each of these vision stations 18 shown in FIG. 1 , diagnostics can be performed to indicate whether the product meets acceptable criteria. If so, discrete elements, such as the core, tissue layers, elastic, etc., continue to be applied in a sequence as desired. If not, no additional discrete elements need be applied.
[0053] In addition to the exemplary components generally found in a web processing apparatus, the present device and methods further include an advanced defect detection system. An embodiment of the defect detection system preferably comprises at least one visual inspection station 18 , but preferably a plurality of visual inspection stations 18 . Each visual inspection station 18 may include a vision sensor, such as an In-Sight Vision Sensor available from Cognex Corporation of Natick, Mass. Since each component part of a product resulting from a web process has a point of incorporation into the product, visual inspection of each component part preferably occurs prior to the point of incorporation. The results of the visual inspections that occur are relayed from each visual inspection station 101 to a programmable logic controller (PLC) (not shown). Each visual inspection station 18 may provide diagnostic capability by monitoring lighting, focus and positioning.
[0054] Machine vision systems typically require digital input/output devices and computer networks to control other manufacturing equipment, in this case the correction sequence initiated by rotation of ring 20 .
[0055] A typical machine vision system will consist of several among the following components:
One or more digital or analog camera (black-and-white or color) with suitable optics for acquiring images Lighting Camera interface for digitizing images (widely known as a “frame grabber”) A processor (often a PC or embedded processor, such as a DSP) Computer software to process images and detect relevant features. A synchronizing sensor for part detection (often an optical or magnetic sensor) to trigger image acquisition and processing. Input/Output hardware (e.g. digital I/O) or communication links (e.g. network connection or RS-232) to report results Some form of actuators used to sort or reject defective parts.
[0064] The sync sensor determines when a part (often moving on a conveyor) is in position to be inspected. The sensor triggers the camera to take a picture of the part as it passes by the camera and often synchronizes a lighting pulse. The lighting used to illuminate the part is designed to highlight features of interest and obscure or minimize the appearance of features that are not of interest (such as shadows or reflections).
[0065] The camera's image can be captured by the framegrabber. A framegrabber is a digitizing device (within a smart camera or as a separate computer card) that converts the output of the camera to digital format (typically a two dimensional array of numbers, corresponding to the luminous intensity level of the corresponding point in the field of view, called pixel) and places the image in computer memory so that it may be processed by the machine vision software.
[0066] The software will typically take several steps to process an image. In this case, the image processing will result in either detection of the appropriate side of the web 16 , or detection of the incorrect orientation 14 of the web 12 .
[0067] Commercial and open source machine vision software packages typically include a number of different image processing techniques such as the following:
Pixel counting: counts the number of light or dark pixels Thresholding: converts an image with gray tones to simply black and white Segmentation: used to locate and/or count parts Blob discovery & manipulation: inspecting an image for discrete blobs of connected pixels (e.g. a black hole in a grey object) as image landmarks. These blobs frequently represent optical targets for machining, robotic capture, or manufacturing failure. Recognition-by-components: extracting geons from visual input Robust pattern recognition: location of an object that may be rotated, partially hidden by another object, or varying in size Barcode reading: decoding of 1D and 2D codes designed to be read or scanned by machines Optical character recognition: automated reading of text such as serial numbers Gauging: measurement of object dimensions in inches or millimeters Edge detection: finding object edges Template matching: finding, matching, and/or counting specific patterns.
[0079] In most cases, a machine vision system will use a sequential combination of these processing techniques to perform a complete inspection. A system that reads a barcode may also check a surface for scratches or tampering and measure the length and width of a machined component.
[0080] Additionally, machine downtime can be minimized by the provision of systems and methods for warning a machine operator of expected machine troubles so that scheduled maintenance can occur.
[0081] The PLC includes software adapted to run several routines that may be initiated by some triggering event, such as an automatic detection of a defined condition or manual input by a machine operator. Some routines are run during machine setup while other routines are run during machine operation, while still other routines are run during machine diagnostics at some point during machine downtime.
[0082] In the present case, the route that the PLC initiates is triggered by detection of the narrow web in an improperly oriented condition. The correction sequence is rotation of ring 22 , carrying web guide plates 22 .
[0083] Referring now to FIG. 1B , a top plan view of the web processing system 10 is shown carrying the web 12 in a properly oriented condition, with side 16 visible from the top. A pair of guide plates 22 carry between them the incoming web 12 . The guide plates 22 are preferably actuated between a closed condition and an open condition by pneumatic air lines 26 , in order to in the closed condition effectuate a twist in the web 12 , and in the open condition, allow splices in the incoming web 12 to pass.
[0084] Guide plates 22 are carried by and coupled to rotatable ring 20 . Ring 20 is rotatable by any means, such as additional pneumatic or belt driven means (not shown).
[0085] Web 12 is passed by a series of rollers 30 and passed downstream for further processing, such as slip/cut application units, introduction onto a disposable product, or intermittent or constant laydown onto other additional webs as desired.
[0086] Referring now to FIG. 2A , a perspective view of a web processing system 10 is shown carrying web 12 in a twisted condition. As previously noted, the twisting often occurs upstream, or just after the material unwind station (not shown). In this twisted condition, unacceptable product could be produced as the web would be in its incorrect facing orientation. FIG. 2B is a top plan view of this condition.
[0087] This condition will be detected by detection (vision) stations 18 , which would detect the presence of incorrect side 14 of the web 12 (as opposed to side 16 ) and reported to the PLC, which will initiate, as shown in FIGS. 3 and 4 , a top and perspective view of the web processing system initiating a correction sequence. In the correction sequence, the ring 20 is rotated 180 degrees either clockwise or counterclockwise, but in the case of FIG. 3 , counterclockwise.
[0088] As shown in FIGS. 4-8 , the correction sequence will result in an inversion of the web by introducing a counter-twist downstream of the ring 20 , which will then pass in migratory fashion downstream as more web material 12 is pulled through the system, until finally in FIG. 8 , the twisted web condition is eliminated downstream. In this condition, web 12 has been restored to its proper orientation, after the web correction sequence has been performed.
[0089] After performing the correction sequence, diagnostics can continue to be performed in regular run mode to indicate whether the product continues meets acceptable criteria. If so, discrete elements, such as the core, tissue layers, elastic, etc., continue to be applied in a sequence as desired. Until, as shown in FIG. 9 a new twist occurs in the web 12 as indicated by the visibility of side 14 of web 12 . At this point, the correction sequence is again triggered by the vision system 18 as previously described. Preferably (although not required), in alternating correction sequences, the ring 20 is rotated counterclockwise ( FIGS. 3-8 ) and clockwise ( FIGS. 9-11 ). This is done in order to minimize the amount of twist imparted upstream of the ring 20 , although some amount of upstream twist is tolerable in the system.
[0090] FIGS. 10-14 show the correction sequence again being accomplished, this time in clockwise fashion with the result once again that the web is returned to its properly oriented condition.
[0091] The vision and data tracking and control is fully disclosed in U.S. application Ser. No. 11/880,261, which is incorporated herein by reference.
[0092] The foregoing is considered as illustrative only of the principles of the invention. Furthermore, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims.
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Apparatus and methods are provided to minimize waste and improve quality and production in web processing operations. The apparatus and methods provide defect detection in deposition of acquisition material, which on current machines frequently flips and is difficult to detect when it has flipped causing manufacturers to scrap thousands of products. Using the present invention, defects are able to be detected by discerning a difference in the appearance from side to side with a vision camera, and an acquisition inverter can flip the material to a correct orientation.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a color image processing apparatus and a color image forming method for forming a color image on a recording medium. The present invention is suitable for use in a color image output apparatus that forms an image by obtaining image data input from outside such as a color facsimile, a color printer, a color copier, etc., or a color printer software that operates inside a computer.
2. Description of the Related Art
In recording a full-color image with a color ink-jet printer, inks in three different colors, cyan C, magenta M, and yellow Y, or otherwise four colors, with the addition of black Bk to the above colors, are used to reproduce the colors of the original image. When the amount of discharged ink for each color approaches its maximum level, the amount of ink applied per unit area may be extremely large and the recording medium such as paper may not be able to soak up all the ink. Thus, the ink may spread out to other portions of the paper, or wrinkles may be created on the paper, thus significantly degrading the recording image quality.
In response to the above problem, various methods for controlling the total amount of ink and toner particles in a color ink-jet printer or a color laser printer have been proposed.
For example, in Japanese Patent Laid-Open Publication No.61-290060, an imaging method for recording an image is disclosed, wherein the total amount of recording material used in the recording is reduced when the total amount of a plurality of colors obtained for each pixel exceeds a predetermined value, while the input image data is processed so that the ratio of the cyan component to the magenta component to the yellow component will not be altered in the reproduced image. Also, in Japanese Patent Laid-Open Publication No.10-86413, a total ink quantity controlling method is disclosed, wherein multi-level image data are converted into bi-level data by reducing the multi-level data according to the size of the multi-level data of each color in the halftone image data.
As an example of an image output apparatus, an ink-jet printer represents an image tone (gray level) through a pseudo-halftone process using a plurality of dots of different sizes generated by changing the amount of discharged ink droplets according to an applied voltage and dither matrixes. FIG. 1A shows the relationship between the input gray level and dot size. FIGS. 1B, 1 C, and 1 D show the dither matrixes for the small dots, medium dots, and large dots, respectively. By way of example, when the input gray level is in the small dot range, the dither matrix of FIG. 1B for the small dots may be used to output small dots on the pixel positions corresponding to threshold values 2, 18, 6, 10, 14, 8, 24, 4, 20, 16, and 12 to reproduce the input gray level.
FIG. 2 shows the relationship between the recording control information and the actual amount of ink drops used in the above ink-jet printer. As is shown in FIG. 2, this relationship is nonlinear.
Basically, the above-described technology for controlling the total amount of coloring material has been developed for a case in which the relationship between the recording control information and the amount of ink drops is linear. Therefore, it is quite difficult to apply this technology to an ink-jet printer in which the relationship between the recording information and the ink drop level is nonlinear.
When a total amount of coloring materials is controlled using recording control information such as the CMYK multi-level data, the amount of ink applied per unit area will be different depending on the combination of the coloring materials; that is, the amount of ink varies depending on whether the relevant color is a primary color, a secondary color, or a tertiary color. For example, in a printer that establishes a relationship between the recording control information and the actual amount of ink drops used to be identical to that shown in FIG. 2, when the total amount of coloring materials is controlled so that the printer is prevented from recording with a total value of the recording control information for each color exceeding 150% of the maximum value for one single color, secondary colors such as blue (cyan: 255, magenta: 255) are recorded at approximately 7000 pl whereas tertiary colors (cyan: 255, magenta: 255, yellow: 255) are restricted to being recorded at around a total of 3000 pl. In such case, sufficient concentration cannot be obtained.
Further, when the relationship between the recording control information and the amount of ink drops is nonlinear, the ratio of colors will be altered even in reproducing secondary colors, that is, the suitable ink quantity can differ greatly even with just a difference in the hue. Thus, as a result of controlling the total amount of coloring materials, the color reproducing range that the printer is originally capable of recording may end up being minimized.
SUMMARY OF THE INVENTION
The present invention has been developed in response to the above mentioned problems of the related art and its general object is to make full use of the capabilities of a color image output apparatus upon reproducing the colors of the image.
Specifically, it is an object of the present invention to provide a color image processing apparatus that is capable of realizing color reproduction in a color image output apparatus having various features by controlling the total amount of coloring materials while making full use of the color reproducing range of the color image output apparatus.
Accordingly, a color image processing apparatus of the present invention for processing recording control information to reproduce a color image includes:
a converter that is adapted to convert the recording control information for each of color components into an amount of coloring material that is to be used after a halftone process; and
a total quantity control unit that is adapted to control the amount of coloring material of each color component based on a total amount of coloring materials of all the color components and a prescribed limit value.
Further, the recording control information may be arranged for an ink-jet printer, and the color image processing apparatus may include:
a first converter that is adapted to convert the recording control information for each of color components into an amount of ink drops that is to be used after a halftone process;
a total quantity control unit that is adapted to control the amount of ink drops of each color component based on a total amount of ink drops of all the color components and a prescribed ink drop limit value corresponding to an image forming condition; and
a second converter that is adapted to convert the controlled amount of ink drops into recording control information.
In this arrangement, the object of the present invention can be realized even in a case where the image forming condition is altered.
Additionally, the first converter and the second converter may perform a conversion by referring to a pre-established table providing a relationship between the recording control information and the amount of ink drops. This arrangement enables the object of the invention to be realized even when the relationship between the recording control information and the amount of ink drops in the image output apparatus is nonlinear.
Also, an image forming condition may include at least one of the material of a recording medium, the printing method, the resolution, the halftone processing method, or the color reproducing method. Thus, the object of the invention may be realized even when the image forming condition changes depending on for what purpose the color image device is used.
Further, the coloring materials may include a black coloring material, and the total quantity control unit is preferably adapted to control the amount of each coloring material other than the black coloring material. This arrangement prevents the degradation of black text contained in the image.
Additionally, the coloring materials may include cyan, magenta, and yellow, and the total quantity control unit is preferably adapted to control the amount of ink drops of each color component without changing the original ratio of the amount of coloring materials of cyan, magenta, and yellow. In this way, the object of the invention can be realized and the desired color can be reproduced.
It is another object of the present invention to provide a color image forming method that realizes color reproduction in a color image output apparatus having a variety of features by controlling the total amount of coloring material while making full use of the color reproducing range.
Such a color image forming method for reproducing a color image on a recording medium may include:
converting recording control information of each color component into an amount of coloring material that is to be used after a halftone process;
calculating a total amount of coloring material of all the color components; and
reducing the amount of coloring material of each color component when the total amount of coloring material exceeds a predetermined value.
It is a further object of the present invention to provide a storage medium storing a color image processing program that enables color reproduction in a color image output apparatus having a variety of features by controlling the total amount of coloring material while making full use of the color reproducing range.
Such a storage medium is adapted to store a program for processing recording control information to reproduce a color image in a color image output apparatus, the program containing instructions for a computer to perform procedures of:
converting recording control information of each color component into an amount of coloring material that is to be used after a halftone process;
calculating a total amount of coloring material of all the color components; and
reducing the amount of coloring material of each color component when the total amount of coloring material exceeds a predetermined value.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A shows a relationship between input grey level and dot size, and FIGS. 1B-1D show dither matrixes for each of the dot sizes;
FIG. 2 shows a relationship between a recording control signal and an amount of ink drops;
FIG. 3 shows an exemplary configuration of an image processing system;
FIG. 4 illustrates the processing functions of a computer and an image processing apparatus;
FIG. 5 shows a configuration of a color converter according to an embodiment of the present invention;
FIG. 6 illustrates a color conversion process performed in a color conversion unit;
FIG. 7 shows a configuration of a total quantity control unit according to an embodiment of the present invention;
FIG. 8 shows a one-dimensional conversion table for converting a recording control signal into an amount of ink drops;
FIG. 9 is a flowchart illustrating an image processing method according to an embodiment of the present invention; and
FIG. 10 shows a configuration of the computer according to an embodiment of the present invention in which image processing functions are realized using a program.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the following, preferred embodiments of the present invention are described with reference to the accompanying drawings.
Configuration of Image Processing System
FIG. 3 shows an image processing system 10 according to an embodiment of the present invention. This image processing system 10 includes a display 100 , a computer 101 , image output apparatuses 1021 - 1024 , and a color image processing apparatus 200 .
Herein, software such as various applications and printer drivers may be implemented in the computer 101 . The display 100 is an output apparatus for displaying image data, and the image output apparatuses 1021 - 1024 are output apparatuses for printing out the image data. The image output apparatuses 1021 - 1024 may include color printers or other suitable types of output apparatuses having printer functions, for example, color copiers. Also, the number of the image output apparatuses used in the system 10 is not limited to four as in the illustrated example, rather, any number of image output apparatuses can be incorporated into the image processing system 10 .
FIG. 4 is a diagram illustrating the processing functions of the computer 101 and the color image processing apparatus 200 in the image processing system 10 of FIG. 3 . The computer 101 sends a depiction command to the color image processing apparatus 200 via software such as an application and a printer driver.
The color image processing apparatus 200 includes a color converter 201 , a rendering device 202 , a band buffer 203 , a tone processing device 204 , and a page memory (memory device) 205 . The color image processing apparatus 200 converts the depiction command sent from the computer 101 into data that can be processed by the image output apparatuses 1021 - 1024 .
Operation of Image Processing System
In the following, an operation of the computer 101 in generating the depiction command will be described.
First, an operator displays image data on the display 100 and edits this data using an application, for example, implemented in the computer 101 . When the editing process is completed, the image output apparatus ( 1021 - 1024 ) from which the image data will be output is selected, and a printing operation is instructed.
When the printing operation is instructed, the display 100 displays a print setup menu for setting printing conditions such as the material of the recording medium, the printing method, the resolution, the halftone processing method, the color reproducing method.
Upon receiving a command instructing the printing operation from the application, the computer 101 sends text data maintained in the application to the printer driver. The printer driver converts the text data into a depiction command that can be received by the color image processing apparatus 200 , and then sends this command to the color image processing apparatus 200 .
Next, an operation of the color image processing apparatus 200 according to the present embodiment will be described.
The color image processing apparatus 200 transmits/receives depiction commands to/from the computer 101 and also sends color data of the depiction command to the color converter 201 . The color converter 201 converts the received color data in the RGB format into color data that is suitable for the image output apparatuses 1021 - 1024 (e.g. color data in the CMYK format), and then sends the converted data to the rendering device 202 . The rendering device 202 converts the image data in command format to data in the Raster format and sends this data into the band buffer 203 . Then, the tone processing device 204 reads the Raster image data from the band buffer 203 , converts this data into tone data that can be processed by the image output apparatuses 1021 - 1024 through dithering, for example, and sends this tone data to the image output apparatuses 1021 - 1024 . In this way, the image output apparatuses 1021 - 1024 are able to print out an image.
In the example of FIGS. 3 and 4, the rendering process, the color conversion process, and the tone process, are performed in the color image processing apparatus 200 , independently from the computer 101 or the image output apparatuses 1021 - 1024 . However, a portion of the above processing functions may be implemented in the computer 101 or the image output apparatuses 1021 - 1024 . Alternatively, the above processing functions may be implemented in a printer control apparatus set independently from the image output apparatuses 1021 - 1024 .
Also, the color image processing apparatus 200 of the present invention can be implemented as software. For example, the functions of the color image processing apparatus 200 can be realized in a printer driver, which is a software program implemented in a computer.
Configuration of Color Converter 201
In the following, an exemplary embodiment of the color converter 201 , including a characteristic feature of the present invention, will be described with reference to FIG. 5 .
The color converter 201 receives input color signals such as RGB signals. The illustrated color converter 201 includes a color conversion unit 301 that converts these signals into CMY signals for the image output apparatuses 1021 - 1024 , an ink processing unit 302 that converts the CMY signals into CMYK signals, which have K (black) components added according to a UCR (Under Color Removal) or UCA (Under Color Addition) rate, a γ conversion (gamma conversion) unit 303 that corrects the image forming engine characteristics, a total quantity control unit 304 that corrects the CMYK signals according to the maximum total quantity value of recording color material that the image output apparatuses 1021 - 1024 are capable of using in recording an image.
Next, the operation of the color converter 201 will be described.
First, RGB input signals, which correspond to the color data of the depiction command received from the printer driver, are sent to the color conversion unit 301 . In the color conversion unit 301 , the input RGB signals are converted into output CMY signals by referring to a pre-established three-dimensional look-up table (not shown), for example. That is, an output CMY signal value corresponding to a representative RGB value in the RGB space is pre-calculated and stored in the three-dimensional look-up table, and the color conversion unit 301 reads a plurality of output values from the three-dimensional look-up table to perform an interpolation computation.
In other words, the RGB (Red, Green, Blue) three-dimensional color space tone data are converted into output color components (C (Cyan), M (Magenta), and Y (Yellow)) data through memory map interpolation. FIG. 6 illustrates the memory map interpolation. Given that the RGB space corresponds to the input space, the RGB space is broken down into identical three-dimensional figures (the space is divided into cubes in this example). In order to obtain an output value P corresponding to the input coordinates (R, G, B), the cube that contains the above input coordinates is selected, and line interpolation is performed based on the weighted average of the volumes V1-V8 of the eight rectangular solid figures obtained from subdividing the selected cube at point P with respect to the output values of eight pre-selected corner points of the selected cube and the position of the input point within the cube (the distance from each of the points to the input point).
The ink processing unit 302 performs a process of replacing the common portions of the CMY components with K (black) components based on the UCR or UCA rate. For example, the CMY signal is converted into a CMYK signal using formulae (1) shown below:
K ′=α×(min ( C, M, Y )− Th )
C′=C −β×(min ( C, M, Y )− Th )
M′=M −β×(min ( C, M, Y )− Th )
Y′=Y −β×(min ( C, M, Y )− Th ) (1)
According to this formula, when α=β=1, and Th=0, the UCR rate will be 100%. Herein, min (C, M, Y) denotes the minimum value of CMY, αand β are constants, and Th denotes the ink-in starting point.
The ink-processed CMYK signal goes through a γ conversion at the γ conversion unit 303 . Then, at the total quantity control unit 304 , the signal is corrected according to the maximum total quantity value of the recording coloring materials with which the image output apparatuses 1021 - 1024 are capable of recording, and sends the corrected signal as a recording control signal to the image output apparatuses 1021 - 1024 via the rendering device 202 , the band buffer 203 , the tone processing device 204 , and the memory device 205 .
In the following, the total quantity control unit 304 will be described in further detail with reference to FIG. 7 .
The total quantity control unit 304 includes a control signal conversion (recording control signal→amount of ink drops) unit 310 , total ink drop quantity control unit 311 , a control signal conversion (amount of ink drops→recording control signal) unit 312 , and a maximum ink quantity memory unit 313 . The control signal conversion (recording control signal→amount of ink drops) unit 310 performs a halftone process for each color component and converts the CMYK signal, which CMYK signal has been γ-converted at the γ conversion unit 303 , into an amount of ink drops (VcVmVyVk) to be used in the imaging. In this conversion process, a one-dimensional table, shown in FIG. 8, is used for providing the relationship between the recording control signal (CMYK) and the amount of ink drops (V). This relationship between the recording control signal and the ink drop quantity is nonlinear, as in FIG. 2 .
The data converted into an amount of ink drops for each color (VcVmVyVk) at the control signal conversion (recording control signal→amount of ink drops) unit 310 is controlled at the ink drop total quantity control unit 311 . For example, the total ink quantity is controlled so that it does not exceed a limit value (maximum total ink drop quantity, ‘Max_Ink’) using formulae ( 2 ) shown below:
When ( Vc+Vm+Vy+Vk )>Max_Ink,
V′c=t×Vc
V′m=t×Vm
V′y=t×Vy
V′k=Vk
t =(Max_Ink− Vk )/( Vc+Vm+Vy ) (2)
Herein, the maximum total ink drop quantity is determined through experimentation.
The limit value of the total ink quantity (maximum total ink drop quantity) is determined by the maximum ink quantity memory unit 313 according to printing (image forming) conditions such as the material of the recording medium, the printing method, the resolution, the halftone processing method, color reproducing method, set by the operator upon instructing a printing operation.
Ink data (V′cV′mV′yV′k) obtained from controlling the amount of ink drops (VcVmVyVk) at the total ink drop quantity control unit 311 are re-converted into a recording control signal (C″M″Y″K″) at the control signal conversion (amount of ink drops→recording control signal) unit 312 . It is noted that the amount of ink drops (VcVmVyVk) is not controlled when the total ink drop quantity value does not exceed the maximum total ink drop quantity (Max_Ink). The recording control signal is then sent to the image output apparatuses 1021 - 1024 via the rendering device 202 , the band buffer 203 , the tone processing device 204 , and the memory device 205 . In converting the amount of ink drops into a recording control signal, the one-dimensional table of FIG. 8 providing the relationship between the recording control signal (CMYK) and the ink drop quantity information may be used, and a reverse conversion with respect to the conversion performed by the control signal conversion (recording control signal→amount of ink drops) unit 310 may be performed. However, the conversion of the amount of ink drops into the recording control signal (CMYK) is not limited to the illustrated table conversion.
FIG. 9 is a flowchart illustrating a color conversion method including the above-described process of converting the recording control information.
First of all, in step S 1 , an input RGB signal is converted into a CMY signal by interpolation using the three-dimensional look-up table (not shown).
In step S 2 , the ink process in which the common portions of the CMY components are replaced with K (black) components is performed according to the formulae (1) so that the CMY signal is converted into a CMYK signal.
In step S 3 , γ conversion is performed to convert the CMYK signal into a printer control signal, and in step S 4 , the printer control signal is converted into an amount of ink drops necessary for each color component.
In step S 5 , the total ink drop quantity for all the color components is calculated. In step S 6 , the total ink drop quantity is compared with the maximum total ink quantity allowed for a particular image forming condition, and when the total ink drop quantity is greater than the maximum total ink quantity, the total ink drop quantity is controlled according to the formulae (2) in step S 7 . In the total ink quantity control, the CMY ink drop quantity is reduced without changing the original CMY color ratio.
In step S 8 , the amount of ink drop quantity for each color is re-converted into a recording control signal (CMYK), and in step S 9 , it is confirmed that all the above processes have been performed for all of the image data and the color conversion process is completed.
According to another embodiment of the present invention, a storage medium that records software program codes that realize the above described image processing functions may be provided in a system or an apparatus, and the computer (alternatively a CPU, or an MPU) of the system or apparatus may be arranged to read and execute the program codes stored in the storage medium.
FIG. 10 shows an exemplary configuration of an image processing system 710 that is capable of executing the image processing programs that realize the functions of the present invention. In this image processing system 710 , a work station 712 and a printer 102 are connected. The work station 712 realizes the above described color conversion functions, and includes a display 100 , a keyboard, a program reading device, and a computation processing device 714 . The computation processing device 714 includes a CPU that is capable of executing various commands, and a ROM and a RAM are connected to the CPU via a bus. Also, a DISK, which is a large capacity storage device, and an NIC that performs communication with the apparatuses within the network are connected to the bus.
The program reading device is a device that reads the various program codes stored in a storage medium such as a floppy disk, a hard disk, an optical disk (i.e. CD-ROM, CD-R, CD-R/W, DVD-ROM, DVD-RAM, for example), a magneto-optical disk, or a memory card. This program reading device may be a floppy disk drive, an optical disk drive, or a magneto-optical disk drive, for example.
The program codes stored in the storage medium are read out by the program reading device and stored in the DISK. The program codes stored in the DISK are then executed by the CPU so that the above described image processing method, for example, can be realized. Also, in another embodiment, the computer 101 may read and execute the program codes, and an OS (operating system), a device driver, for example, may perform all or a portion of the actual processes based on the instructions of the program code.
Alternatively, the program codes read out from the storage medium may be written in a function extending card inserted in the computer or a memory that is implemented in a function extending unit connected to the computer 101 , wherein the function extending card or a CPU implemented in the function extending unit performs all or a portion of the actual processes to realize the functions of the present invention.
Further, the present invention is not limited to the above described preferred embodiments, and variations and modifications may be made without departing from the scope of the present invention.
The present application is based on and claims the benefit of the earlier filing date of Japanese priority application No.2002-165204 filed on Jun. 6, 2002, the entire contents of which are hereby incorporated by reference.
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A color image processing apparatus realizes color reproduction in a color image output apparatus by controlling the total amount of coloring material used while making full use of the color reproduction range of the color image output apparatus. To this end, a signal C′M′Y′K′, obtained after a γ conversion (gamma conversion), is converted into an amount of ink drops V (CMYK) at a conversion unit. Then, at a total ink drop quantity control unit, a total ink quantity of the amount of ink drops converted at the conversion unit and a limit value (maximum total ink drop quantity) stored in a maximum total ink quantity memory unit are compared, and the total ink quantity is controlled to be lower than the limit value. Then, the controlled amount of ink drops is converted into a recording control signal C″M″Y″K″ at a control signal conversion unit.
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BACKGROUND
In the course of operating a computer on a network, computer application processes need to access the host computer's file system through a variety of system calls. In systems of the prior art, when the file system is corrupt, the software requesting access to a file system resource will hang, often with no way to be killed, or terminated. Problem elements of the file system are bad disk sectors, bad inode table, full inode table, bad FAT tables, etc. Once the software hangs, it is necessary for the user to reboot the system in order to resume. The system is rebooted so that the operating system (OS) will exclude the corrupt file system from being mounted. Once the software hangs, it usually requires a user to personally either reboot the system or repair the corrupted file system.
Problems with a corrupt file system are even more critical with the widespread use of storage area networks (SANs). More and more network devices now attempt to access storage file systems of the SAN. The benefits of SANs, e.g., storage scalability, availability, and flexibility, are becoming clearer as the entire IT industry adopts this storage topology. As SANs grow to accommodate the growth in storage requirements, the task of managing this business-critical resource, without increasing staff, becomes daunting.
To help customers manage their SANs, a powerful, integrated suite of SAN-management software products, collectively called OpenView Storage Area Manager (OVSAM), have been developed and are available through the Hewlett-Packard Company. These products provide a single, centralized solution for managing a SAN. The products automatically discover storage devices, interconnect devices, and hosts, to enable a user to proactively manage more storage with less effort.
SUMMARY
The system and method described herein automatically detect various corruptions in a file system and notify a system administrator of the corruption. Detailed information on the file system is collected by a probe process. If the file system is corrupt or inaccessible, the system and method marks the file system as bad, notifies the system administrator and then ceases to attempt to collect information on that system again until it has been repaired.
DESCRIPTION OF THE DRAWINGS
The detailed description will refer to the following drawings, wherein like numerals refer to like elements, and wherein:
FIG. 1 illustrates a flow diagram of an exemplary process to monitor a file system for corruption; and
FIG. 2 is block diagram showing an exemplary storage area network with three file systems.
DETAILED DESCRIPTION
A feature of the apparatus and method described herein is to probe the health status of a system. Probing of the file system is done by appending data to an opened data file. The file is opened by a probe process. If appending data to an opened data file is successful within an adjustable time interval (e.g., PROBE_INTERVAL, where the default is 1 second), the file system is considered to be functioning well and responsive to the users. If a file system doesn't respond to the outside users within the time interval, the probe will then continue for a specified number of tries (e.g., MAX_PROBE, where the default is 300 times). If the file system is still not able to append data to the opened data file after the selected time period of PROBE_INTERVAL*MAX_PROBE, the file system is considered as corrupted.
Referring now to FIG. 1 , there is shown a flow diagram of an exemplary method, generally designated by the reference numeral 100 , for probing a file system to detect corruption therein. The described method operates on various operating systems, but each operating system has its own indicators of file system corruption. For instance, Unix and Linux use an inode table. If the operating system of the target computer is Unix or Linux, as determined in step 101 , then a determination is made as to whether the inode table is full or bad, in step 103 . It will be apparent to one of ordinary skill in the art that step 103 can be customized for any operating system that has unique indicators of file system corruption. For instance, for a Windows™ operating system, the FAT table is checked. Inode or FAT table checking is different from appending data to the opened file. Operating System APIs are relied upon to find out such information. Further, there are other reasons why a file system is corrupted that are tested, for instance, if someone pulls out the hard disk prematurely. If the test for a bad table fails, then the probe process attempts to append data to an opened file on the file system, in step 105 . The probe process basically tries to collect some basic file information by attempting the write/append: the probe process basically tries to probe the health status of the file system by appending data to an opened file. If the process doesn't come back right away (within PROBE_INTERVAL*MAX_PROBE time), then the process streams bytes back to the main process. If the same number of bytes is not received back within a certain amount of time, then the file system can be marked as corrupted. If the write is successful within the specified time interval, PROBE_INTERVAL, then the file system is declared okay, in step 109 . If the write is not successful in the specified time, then it is determined whether the number of tries exceeds the maximum specified, MAX_PROBE, in step 107 . If the maximum number of tries has been exceeded without a successful write/append, or the inode table was full or bad, then a file system corrupted message is posted to the system administrator, in step 111 . If the maximum number of tries has not been exceeded, then the probe process continues at step 105 to attempt another write/append.
The exemplary method uses two time out thresholds to make this detection mechanism both responsive and generic. If a file system works well, the detection returns fairly quickly, i.e., within the PROBE_INTERVAL. If a file system fails to write data, e.g., within the afore-mentioned the MAX_PROBE=300 seconds, it is fairly safe to assume that file system is in bad shape for some reason. In an exemplary embodiment, the two time out thresholds (PROBE_INTERVAL and MAX_PROBE) are configurable to handle the extreme case that a file system works but does not write data to the data file within a default time, for instance, if the system load is extremely heavy. Thus, the threshold, MAX_PROBE, can be set to a bigger number. To make the probing more responsive, PROBE_INTERVAL can be set to a small number, for instance, 100 milliseconds.
In one embodiment, this implementation of the file system corruption mechanism is incorporated into the Storage Builder of Open View Storage Area Management (OVSAM) 3.0. As before, default thresholds (PROBE_INTERVAL=1 second and MAX_PROBE=300) are used in the tests. The probe process is always on during a file collection, to make sure the process will not hang. In this embodiment, when there is no need to collect data for an OVSAM Storage Builder, the probe process is turned off. When the corrupted file system is fixed, the probe process can be notified via the a graphic user interface or command line interface (GUI/CLUI) to enable file collection on that corrupted file system again.
The present system and method is system-independent. One embodiment is written in JAVA™ and has different native codes for Windows™ and UNIX. In an exemplary embodiment, the probe process is implemented as native code on UNIX and Windows™ using C to append data to an opened data file. The file system corruption detection framework in this embodiment is written as Java™ code.
Referring now to FIG. 2 , there is shown an exemplary storage area network 200 having several file systems. In the exemplary network 200 , a host CPU 201 is connected to a network of file systems 205 , 207 , and 209 . Suppose that file system FS 1 205 has become corrupt. If the host CPU 201 tries to access file system FS 1 205 , it will be unable to do so, and the application requiring access to FS 1 205 will typically hang and never return. It is advantageous for the applications to know when a file system is corrupt to bypass it or more quickly return from an operation. The probe process 203 runs on a host CPU 201 , which has three file systems mounted 205 , 207 , and 209 , respectively. The probe process 203 creates a data file on each file system and appends data to each to probe the status of the file system. As described above, the file system is considered to be corrupted if the appending is unsuccessful within the interval of PROBE_INTERVAL*MAX_PROBE.
The probe process software goes out to all of the attached file systems and retrieves information to find out how much capacity is left on the respective file systems. This process sends out an event and a desired action associated with the event. The action is user selectable, and can be e-mailing, paging or just appearing as a warning on the application process. The probe process is always on when a file collection is performed as a safeguard to make sure the application software does not hang. Once a corrupt file system is fixed, the user can check this file system, and then the disks of file systems will be collected on again.
It will be apparent to one skilled in the art that the described system and method is scalable to multiple file systems on a network of computers. The probe process will typically reside on the host computer that controls a given file system. However, any computer on the network that can run the operating system APIs on the file systems can host the probe process.
As noted, an advantage of this corrupted file system detection is that it is system-independent. The same concept carries over to all the file systems. Another advantage is using a multi-level time-out mechanism. Such mechanisms have the great advantage that not much performance penalty is brought to a good file system, and a corrupted file system can be detected quite fast. A further advantage is that the time-out thresholds are user-selectable. Thus, the time-outs are adaptable for different work loads.
The terms and descriptions used herein are set forth by way of illustration only and are not meant as limitations. Those skilled in the art will recognize that many variations are possible within the spirit and scope of the invention as defined in the following claims, and their equivalents, in which all terms are to be understood in their broadest possible sense unless otherwise indicated.
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The system and method described herein automatically detect various corruptions in a file system and notify a system administrator of the corruption. Detailed information on the file system is collected by a probe process. If the file system is corrupt or inaccessible, the system and method marks the file system as bad, notifies the system administrator and then ceases to attempt to collect information on that system again until it has been repaired.
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REFERENCE TO RELATED APPLICATIONS
This application is a nonprovisional of U.S. Provisional Application No. 61/738,278, filed Dec. 17, 2012, which claims priority to German Application No. 20 2012 011 960.5, filed Dec. 14, 2012, the entire contents of which are incorporated herein by reference.
FIELD OF THE INVENTION
The invention relates to an intervertebral fusion implant for fusing two adjacent vertebrae, comprising an adjustable support body, the base surface and cover surface of which are configured to bear on the vertebrae.
BACKGROUND OF THE INVENTION
The intervertebral disks of the vertebral column suffer degeneration as a result of wear or of pathological changes. If conservative treatment by medication and/or physiotherapy is ineffective, surgical treatment is sometimes indicated. In this connection, it is known for a movable or immovable implant to be inserted into the intervertebral space containing the degenerated intervertebral disk. This implant takes over the support function of the degenerated intervertebral disk and to this extent restores a stable support between the adjacent vertebrae. Immovable implants are also referred to as “fusion implants”.
Various surgical techniques are known for implanting the fusion implants. A traditional surgical technique involves a ventral access route, in order thereby to avoid the danger of damaging the spinal cord in the vertebral column. However, this advantage is obtained at the price of a very long access route through the abdominal cavity or thoracic cavity of the patient. Since this can cause complications, an alternative access route has become established, namely from the dorsal direction. Although the latter affords the advantage of a short route, there is the danger of collision with or damage to the spinal cord. To minimize this danger, the operation is usually performed by minimally invasive surgery. Approaches of this kind directly from the dorsal direction or more from the side are known as PLIF (posterior lumbar intervertebral fusion) or TLIF (transforaminal lumbar interbody fusion), in which the intervertebral disk is exposed from the posterior or lateral direction, respectively. Because of the small transverse incisions used in the approach by minimally invasive surgery, the size of the fusion implants is of course greatly restricted here.
For treatment using the PLIF or TLIF technique, very small fusion implants are known. They afford the advantage of being able to be implanted by minimally invasive surgery thanks to their small size. However, an inherent disadvantage of their small size is that the support function is limited because of the small dimensions and is sometimes inadequate. Although a larger size of the fusion implants would improve the support function, this is impractical because of the limits of minimally invasive surgery.
SUMMARY OF THE INVENTION
The invention has set out to improve a fusion implant of the type mentioned at the outset to the extent that, while still having a small access cross section, as is conventional for minimally invasive surgery, it can nevertheless achieve an improved support effect.
In an intervertebral fusion implant for fusing two adjacent vertebrae, comprising an adjustable support body, the base surface and cover surface of which are configured to bear on end plates of the adjacent vertebrae, provision is made, according to the invention, for a side bracket, which can be pivoted laterally about a hinge and the base and cover of which have a planar extension, and provision is furthermore made for an actuation means for pivoting out the side bracket into a position (working position) spread from the support body.
The invention is based on the concept of developing an intervertebral fusion implant which has particularly small dimensions in an assembly position and can, after the assembly at the envisaged implantation site, be actuated in such a way that it becomes larger and thereby affords a larger support surface for support in the intervertebral space. The latter state is referred to as working position. As a result, the implant according to the invention unifies the advantage of access through a comparatively small access opening, as is typical for minimally invasive surgery, with the advantage of a comparatively large support surface, as is typical for conventional implants implanted in a substantially more invasive fashion.
The invention is based on the concept of, as a result of a lateral pivot mechanism, configuring the implant to be as small as possible for assembly and, by pivoting out, configuring the implant to be as large as possible at the envisaged implantation site. Here the seemingly contradictory goals of, firstly, the small size for implantation and also of the largest possible support surface for fusing the vertebrae to one another are linked. The implant according to the invention is therefore also suitable for treating comparatively large-area defects of an intervertebral disk, to be precise even if the operation is merely to be undertaken by way of minimally invasive surgery. There are no examples of this in the prior art.
The side bracket is expediently configured as a toggle expander, which comprises a pivot arm with a spreader arm. The result of this is an approximately triangular structure, which enables good and safe guidance of the pivoting-out arm, and the risk of jamming during the pivoting, which could lead to blocking of the implant, is effectively counteracted thereby. It is particularly expedient if the spreader arm is locked on the support body in the working position. Such locking ensures that the working position is maintained, even if large loads occur. In a proven embodiment, a sliding piece is attached to the spreader arm and displaced, in particular retracted, by the actuation means during the spreading and it preferably latches into recesses when the working position is reached. The latching results in positive locking, affording particularly high security against undesired detachment.
In order to ensure as small as possible dimensions of the implant during the assembly, the side bracket is preferably retracted into the support body. The smallest possible design is obtained by such positioning. As a result of this, the largest possible size of the support body can be selected; accordingly, the side bracket retracted therein can also be selected to be relatively large.
In order to simplify the insertion and counteract the risk of catching on surrounding tissue, the base and the cover of the side bracket are preferably configured such that they lie flush against the base and/or cover surfaces of the support body in the assembly position. This results in a continuous surface without interspace. It has particularly proven its worth if the base and the cover of the side bracket lie in a plane, i.e. they are aligned with the base and/or cover surface of the support body. What this achieves is that, after spreading, the base and the cover of the side bracket have reliable contact with the end plates of the two adjacent vertebrae, to be precise in the same manner as the support body itself.
In order to promote the implant growing into the intervertebral space, provision can be made for cutting teeth to be arranged on the base surface and/or the cover surface of the support body and/or on the base or cover of the side bracket. The cutting teeth can, particularly during the spreading motion, bring about trimming of the endplate, as a result of which natural bone growth and hence the sought-after fusion of the two vertebrae is promoted and accelerated.
A widening is expediently provided at the free end of the side bracket, to be precise respectively for the base and for the cover. This widening increases the load-bearing surface in the region of the free end of the side bracket. The supporting effect is thereby further improved.
It has proven its worth to design the side bracket to be shorter than what corresponds to the length of the support body. A preferred value lies in the range from 0.7 to 0.9 times the length of the support body. A geometry for the spread state that is very expedient for the practical requirements emerges if the hinge for the side bracket is positioned in such a way that the support body and the side bracket form an approximate isosceles triangle in the spread state. This can achieve a secure support of the end plates, particularly in the regions thereof close to the edge, which are provided with a relatively hard cortical layer. The support effect is then substantially better than in the case of conventional implants, which, due to their small nature, are rather to be positioned in the center of the end plates where the load capacity of the vertebrae is significantly smaller.
The side bracket is preferably configured in such a way that it pivots out at least by a travel corresponding to three times the value of the width of the support body. The result of this is a base width for the implant which enables secure support, even in the case of only a single implant in an intervertebral space.
For the practical application, it is advantageous if an end face, preferably an anterior end face, of the support body is beveled and substantially flat. Here, the anterior end face is understood to be the one which, in the implanted state, points to the frontal side of the patient; accordingly, the posterior side is the one which points in the dorsal direction. By virtue of the end face being flattened, the risk of tissue irritations of the tissue adjoining the vertebral bodies, in particular of the large vessels extending there, is reduced. The risk of injuries as a result of the implantation is significantly reduced thereby.
In order to enable reliable actuation of the intervertebral fusion implant through the same access which is also provided for the implantation of the implant, provision is preferably made for an end-face connector, preferably on a posterior end face, for the actuation means. As a result, the actuation can occur through the same access, without this requiring a change of the access or even the laying of an additional access.
The actuation means expediently has a self-retaining design. What this achieves is that the side bracket is fixed in the pivoted-out position without additional support. An expedient embodiment for the actuation means provides for a spindle as actuator. This enables precise movement true to position since every rotational movement of the spindle achieves a specific defined measure of spreading predetermined by the pitch. Furthermore, the spindle enables reversible actuation such that the spreader arm can optionally also be pivoted back in again if unexpected problems arise during the implantation. The spindle affords the further advantage of being inherently self-retaining.
If the self-retaining property is not to be decisive after spreading has taken place because, for example, the bracket is in any case securely held in its spread position by locking, provision can be made for the spindle to be removable. As a result, it is possible for the spindle to be removed after the implantation is complete. On the one hand, this affords the advantage that material foreign to the body does not necessarily remain and, on the other hand, this affords the advantage of it being possible to introduce bone material, such as grafts or chips, into the cavity in the support body created thus. Bone material introduced thus promotes bone growth and thereby accelerates the fusion of the adjacent vertebral bodies. Provision is preferably made for an opening through which, in the case of an actuation means, there is a clear access to the cavity in the support body. This will often be the opening through which the actuation means was introduced into the support body.
The invention furthermore is furthermore based on the concept of an instrument set for the intervertebral fusion implant, comprising a guide tube, an insertion rod and an actuation rod. The insertion rod is inserted into the guide tube and connected to the intervertebral fusion implant on the posterior end face thereof. For the rotationally secure hold of the implant on the guide tube, the latter preferably has a tongue which is designed for engagement into a corresponding recess in the support body of the intervertebral implant. Finally, the actuation rod is pushed through the guide tube with the insertion rod. It serves for actuating the actuation means. It preferably itself carries part of the actuation means, namely in the form of a thread at the front end thereof, with the thread acting as a spindle for the actuation means.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be explained in more detail below with reference to the attached drawing, in which advantageous exemplary embodiments are depicted. In detail:
FIG. 1 shows a schematic view of an intervertebral fusion implant, in the intervertebral space between the vertebral bodies;
FIG. 2 shows illustrations of the exemplary embodiment in accordance with FIG. 1 in assembly position and working position;
FIG. 3 shows a perspective illustration of a first exemplary embodiment;
FIG. 4 shows an illustration of an instrument set;
FIG. 5 shows a detailed illustration in relation to connecting an insertion instrument;
FIG. 6 shows a frontal view of a second exemplary embodiment;
FIG. 7 shows a perspective illustration of a second exemplary embodiment;
FIG. 8 shows illustrations of the second exemplary embodiment for an intermediate state during the assembly and after completion of the assembly in the working position; and
FIG. 9 shows illustrations of a third exemplary embodiment in assembly and working position.
DETAILED DESCRIPTION OF THE INVENTION
An intervertebral fusion implant, denoted by reference sign 1 in its entirety, is provided for implantation in an intervertebral space 91 between two immediately adjacent vertebral bodies 9 , 9 ′. In a physiologically intact vertebral column, an intervertebral disk 90 is located in the intervertebral space between the vertebrae. This intervertebral disk may undergo degeneration as a result of disease or wear, with the result that it has to be at least partially resected. In order to achieve sufficient support of the intervertebral space 91 , despite the loss of intervertebral disk material, and to thereby prevent collapse of the vertebral column, the intervertebral fusion implant 1 is inserted into the intervertebral space 91 . It provides a supporting action and thus facilitates fusion of the two adjacent vertebrae 9 , 9 ′ in a natural way through bone growth.
Reference is now made to the illustration in FIGS. 2 and 3 . The first exemplary embodiment depicted there comprises a support body 2 with a side bracket 3 arranged thereon in a pivotable manner by means of a hinge 30 . The side bracket has a two-part design with a pivot arm 31 , which is mounted movable in a pivoting manner with one end on the hinge 30 and is likewise connected movable in a pivoting manner to a spreader arm 32 by means of a second hinge 36 . This results in a structure which can pivot out like a toggle (cf. FIG. 2 b ).
Provision is furthermore made for an actuation means 4 , which, in the depicted exemplary embodiment, comprises an integrated actuation spindle 41 and a sliding piece 42 . The sliding piece 42 is arranged movable in a pivoting manner on the free end of the spreader arm 32 by means of a holding pin 43 . In the center, the sliding piece 42 has a through-hole with a female thread. The spindle 41 of the actuation means is guided therethrough and the former is mounted in a posterior end wall 22 of the support body 2 by means of the head 44 thereof. If the spindle 41 is rotated by rotating the spindle head, the sliding piece 42 moves in the posterior direction, starting from an assembly position (see FIG. 2 a ) at the anterior end of the spindle, wherein the pivot arm 31 and the spreader arm 32 pivot out laterally like a knee joint.
On its anterior, front end face 21 , the support body 2 has a flat bevel. The latter has an angle of approximately 20° with respect to a normal of a longitudinal axis of the support body 2 formed by the spindle 41 . What this bevel achieves is a flat, non-protruding design of the front end face. The risk of irritation of tissue lying in front of the vertebra is thereby minimized.
The support body 2 has a cover surface 23 on its upper side and, correspondingly, a base surface 24 on its lower side. They serve for bearing on the corresponding end plates 92 , 93 of the two adjacent vertebral bodies 9 , 9 ′. Flush on a level therewith is the cover 33 or the base 34 of the side bracket 3 . What this achieves is that there is support on the pivoted-out side bracket at the same level as the support from the support body 2 . In the assembly position, the cover 33 lies flush on the cover surface 23 of the support body; the same applies accordingly to the base 34 in respect of the base surface 24 .
Teeth 5 are arranged on the cover 33 and on the base 34 (not depicted there). The teeth are aligned in such a way that, when the side bracket 3 is pivoted out, they remove bone material from the associated end plate 92 , 93 and, as a result, carry out trimming of the bone in this region.
For implantation purposes, provision is made for an instrument set 7 , which is depicted in FIG. 4 . It comprises an insertion rod 70 , a guide tube 73 and an actuation rod 76 . The insertion rod is pushed through the guide tube 73 and, with the front end thereof, is attached to the support body 2 of the intervertebral fusion implant 1 . The group created thus can be introduced into the intervertebral space 91 through a minimally invasive access, which for example was created within the scope of the PLIF (posterior lumbar intervertebral fusion) method. It then assumes there the position depicted in FIG. 2 a . In a next step there is spreading by the actuation means. In the depicted exemplary embodiment in accordance with FIGS. 2 and 3 , a suitable screw drive is, to this end, inserted into the screwing head 44 of the actuation spindle 41 and the side bracket 3 is thereby pivoted out by rotating the spindle 41 . This occurs in such a manner by virtue of the sliding piece 42 being pulled in the posterior direction, i.e. toward the screw head 44 , by the spindle 41 being rotated and hence by virtue of the spreader arm 32 attached there pivoting out the side arm 31 . Finally, the assembly position depicted in FIG. 2 b is reached.
In FIG. 2 b , it is possible to identify that, in particular, the hard cortical edge of the vertebral body, identified by the dashed line, bears on broad surface portions on the cover surface or base surface in a manner expedient for force transmission, namely in the region of the posterior end face and the anterior end face of the support body 2 and on the widening 39 provided on the side bracket 3 . Thanks to this broad design, a very good force transmission can be achieved even with a comparatively small implant.
The third exemplary embodiment depicted in FIG. 9 is a variant of the first exemplary embodiment. It differs substantially in that the side bracket 3 is hinged on the posterior end using a hinge 30 ′, and not on the anterior end as in the first embodiment depicted in FIGS. 1 to 3 . The intervertebral fusion implant in accordance with the third exemplary embodiment therefore accordingly spreads in an opposite sense, namely in the anterior direction. As a result, a screw head 44 ′ for the actuation spindle 41 is situated on the same side as the hinge 30 ′, which correspondingly has a lateral offset in order to provide sufficient installation space here. Furthermore, the posterior end face 23 ′ is also beveled in this embodiment in order to achieve a termination which is as smooth as possible and does not harbor the risk of irritating surrounding tissue. Otherwise, the same parts have the same functions as in the above-described first exemplary embodiment. They are also provided with the same reference signs. In this respect, reference is made to the description above.
A second exemplary embodiment is explained with reference to FIGS. 5-8 . It substantially has the same design as the first exemplary embodiment, with the same or similar elements being denoted by the same reference signs. It differs in terms of the actuation means 4 ′. Thus, the actuation means 4 ′ provides a sliding piece 42 , by means of which spreading of the side bracket 3 is achieved in the same fashion as in the first exemplary embodiment. However, the actuation means 4 ′ does not comprise its own spindle, but merely a corresponding spindle mount in an enlarged opening 25 on the posterior end face 22 of the support body. This enlarged opening 25 can be provided with a female thread. The diameter thereof is approximately twice the size of the through-hole with the thread, leading through the hinge piece.
Furthermore, a U-shaped recess 27 extending from the end face 22 is provided on the base side 24 of the support body 2 . It serves for holding a fixation tongue of the instrument set, as will be explained below.
Furthermore, recesses 28 are arranged on the cover and base surfaces 23 , 24 in the region of the support body in which the sliding piece 42 is positioned in the working position. These recesses are shaped in such a way that they hold the sliding piece-side end of the spreader arm 32 in an positive locking manner. In this fashion, the spreader arm is locked in the anterior/posterior direction, as a result of which the pivot arm 31 is also locked in its pivoted-out position. In order to ensure secure, positive locking, the hinge piece-side end of the spreader arm 32 is provided with engagement edges 38 . The recesses 28 and 38 thus together form a locking means 8 .
As a result of the locking means 8 being independent of the actuation means 4 , it is no longer necessary for a spindle 41 to remain in the implant after pivoting-out the side bracket 3 . Said spindle can therefore be removed. As a result, the opening 25 provided for holding the spindle head 44 becomes unoccupied and can act as access opening to an interior space 20 in the support body 2 . As a result, grafts or chips with bone material can be introduced through the minimally invasive access after inserting the implant and spreading it into the working position in order thereby to promote the fusion of the two adjoining vertebral bodies 9 , 9 ′.
In the following text, the implantation is described with reference to the instrument set, as depicted in FIG. 4 . The guide tube 73 has a tongue 74 at its front end, which engages in an positive locking manner in the recess 27 in the support body 2 and thus fixes the latter secured against rotation on the guide tube 73 . The insertion rod 70 is pushed through the guide tube 73 and the thread 71 thereof at the front end is screwed into the female thread in the opening 25 . As a result, the implant at the guide tube 73 is securely held on the insertion rod 70 (see FIG. 5 ). In the next step the actuation rod 76 is guided through the insertion rod 70 which, for this purpose, has been drilled to be hollow. With its thread 77 , the actuation rod 76 engages into the sliding piece 42 . As a result, the implant 1 ′ is held on the instrument set in its assembly position, as depicted in FIG. 6 . It can then be introduced into the intervertebral space 91 through the minimally invasive access. After this, the sliding piece 42 is moved in the posterior direction by rotating the actuation rod 76 , which acts as spindle for the actuation means 4 , as a result of which the spreader arm 32 is moved outward and the pivot arm 31 is accordingly pivoted out in the lateral direction. The assembly position with fully pivoted-out pivot arm 31 is reached when the detents 38 of the locking means 8 engage in the recess 28 . As a result, the implant is locked. The actuation rod 76 can then be taken out and the guide tube 73 with the insertion pin 70 can likewise be removed.
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The invention relates to an intervertebral fusion implant for fusing two adjacent vertebrae, comprising an adjustable support body, the base surface and cover surface of which are configured to bear on end plates of the adjacent vertebrae, wherein provision is made for a side bracket, which can be pivoted laterally about a hinge and the base and cover of which have a planar design, and provision is made for an actuator for pivoting out the side bracket into a position (working position) spread from the support body. As a result, the implant has particularly small dimensions and can, after assembly at the envisaged implantation site, be actuated in such a way that it becomes larger and thereby affords a larger support surface for support in the intervertebral space. Thus, even comparatively large-area defects can be treated by minimally invasive surgery.
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CROSS REFERENCE TO RELATED PATENT APPLICATION
[0001] This application claims the benefit of U.S. Provisional Patent Application No. 61/697,058, filed Sep. 5, 2012, which is hereby incorporated by reference herein in its entirety.
TECHNICAL FIELD
[0002] The disclosed subject matter relates to systems, methods and devices for washing or drying items, including personal care and delicate items. More particularly, the disclosed subject matter relates to systems, methods and devices for washing items that are susceptible to damage when placed in washing machines or dryers, for example, personal care items, prosthetic devices and delicate items such as lingerie, brassieres, and other intimate apparel.
BACKGROUND
[0003] Given that intimate apparel is often not subject to the same wear and tear that regular garments are, it is often very delicately constructed. Adding to the delicate construction of such apparel is the proximity it shares with the wearer as well as the desired aesthetics it is expected to exude. Even in instances where intimate apparel is not nearly as delicate in construction, it is, nevertheless, constructed keeping in mind certain enhancements or features that appeal to its wearer. For example, a brassier may be constructed such that it enhances and/or supports the wearer's breasts. Similarly, speciality thongs and underwear are often constructed to enhance the buttocks of the wearer. Such a construction typically requires special care in handling, washing, drying, etc., than afforded regular garments to maintain the integrity of the offered enhancements and other features. Indeed, washing machines and dryers try to address such concerns by offering, for example, a delicate spin cycle and variations in drying temperatures. The foregoing concern is not limited to intimate apparel, but also extends to other items, for example, prosthetic devices that, too, require delicate handling when being cleaned and/or dried.
[0004] Despite efforts to address issues relating to the cleaning and drying of items requiring special care by, for example, offering a delicate spin cycle or variations in drying temperatures, such items, nevertheless, suffer damage. For example, traditional washing of bras in a standard washing machine generally results in the bra straps of two or more bras becoming entangled, forming a “Gordian Knot” that is difficult and frustrating to unravel.
[0005] In addition to offering a delicate spin cycle and variations in drying temperatures, numerous attempts have been made to eliminate this frustration by providing holders/containers for brassieres and similar garments for use during washing and/or drying. However, such efforts have predominantly suffered from various limitations in addressing the problem, and some have even introduced further complications.
[0006] Related patents and published patent applications known in the background art include the following, which are incorporated herein in their entirety.
[0007] U.S. Pat. No. 2,473,408, issued to Alkin on Jun. 14, 1949, discloses clothes hanger providing an improved form and disposition of clips which are adapted to suspend items and permit a tension to be applied to the clipped part of the item.
[0008] U.S. Pat. No. 5,320,429, issued to Toyosawa on Jun. 14, 1994, discloses a laundry net for holding a brassiere while the brassiere is being laundered, has a dome-shaped bag having a substantially circular bottom member and a substantially conical upper member joined thereto for covering cups of the brassiere.
[0009] U.S. Pat. No. 5,556,013, issued to Mayer on Sep. 17, 1996, discloses an intimate garment protector for protecting a garment or multiple garments, namely bras, during laundering. The device comprises first and second basket members that are designed and configured to receive the cup portions of at least one bra. Preferably, the basket members have a generally dome-like or conical-like shape.
[0010] U.S. Pat. No. 5,829,083, issued to Sutton on Nov. 3, 1998, discloses a device used during washing of a brassiere to protect the brassiere and maintain the shape of the cups of the brassiere. It includes an inner spherical framework contained within a larger outer spherical framework. Each framework is formed by a pair of hemispherical sections that upon being coupled together form the individual frameworks. With the inner framework open, the brassiere is fitted over the hemispherical sections, with one section being placed inside each cup of the brassiere. The sections of the inner framework with the brassiere thereon are then closed and placed inside an open outer framework. The outer framework is then closed to enclose the inner framework, and the assembly of frameworks is placed into a washing machine.
[0011] U.S. Pat. No. 5,971,236, issued to DesForges et al. on Oct. 26, 1999, discloses a device for protecting a brassiere in a washing machine that includes a pair of hemispherically shaped shells (preferably injection molded polypropylene material) adapted to assemble together over a cup of the brassiere as a protective covering for the cup. The outer shell has a circularly shaped first rim portion and a hemispherically shaped first dome portion larger than the cup of the brassiere that extends to the first rim portion. The inner shell has a circularly shaped second rim portion and a hemispherically shaped second dome portion that extends to the second rim portion, said second dome portion having a size adapted to fit within the first dome portion of the outer shell with the first and second rim portions in concentric relationship and the cup of the brassiere disposed intermediate the first and second dome portions.
[0012] U.S. Pat. No. 6,234,368, issued to DesForges et al. on May 22, 2001, discloses a device for protecting a brassiere and other delicate undergarments during laundering and includes a pair of domed or hemispherically shaped shells adapted to assemble together over a cup of the brassiere as a protective covering for the cup. The outer shell has a circularly shaped first rim portion and a hemispherically shaped first dome portion larger than the cup of the brassiere that extends to the first rim portion. The inner shell has a circularly shaped second rim portion and a hemispherically shaped second dome portion that extends to the second rim portion, said second dome portion having a size adapted to fit within the first dome portion of the outer shell with the first and second rim portions in concentric relationship and the cup of the brassiere disposed intermediate the first and second dome portions.
[0013] U.S. Pat. No. 6,742,683, issued to Phan on Jun. 1, 2004, discloses a device for washing, drying, and storing brassieres and bikini tops and the like comprises an outer shell having two halves that have a plurality of holes. A foraminous inner form, which also contains a plurality of holes, has an exterior surface shaped like the contours of a padded bra cup breast side. The bra cups' breast side rests against the inner form's exterior surfaces to prevent it and the bra's underwires from losing their natural curvature. The inner form is hollow and provides space for the containment of a bra's shoulder and back straps. The inner form is secured to the outer shell's two halves by a first hinge, which allows the inner form to swing from first half to second half and vice-versa, and also allows first half and second half to open and close like a clamshell. A second hinge is located between the first hinge and the inner form to allow the inner form to swing away from the outer shell's two halves and back to its original position for easy placement and removal of bra(s) inside in the device. A latching mechanism secures the device in a closed and locked or latched position and is located between the exterior and interior surfaces of the outer shell's two halves. The protruding rim on one half of the outer shell nestles within the receiving rim on the other half to prevent lateral movement of the two halves.
[0014] U.S. Pat. No. 6,973,808, issued to Peska on Dec. 13, 2005, discloses an apparatus for washing at least one item, comprising a frame having a dome shape when viewed from its end, and a generally semicircular shape when viewed from its side; and a flow through mesh on the frame which allows washing fluid (generally water) to freely flow to and from the item being washed; the apparatus having an opening through which the at least one item to be washed can be placed into and removed from the apparatus. The frame may have an endless pocket; and a stiffener disposed within the pocket, the stiffener having a length exceeding that of the endless pocket, so that ends of the stiffener overlap each other within the pocket.
[0015] U.S. Pat. No. 7,350,679, issued to Radtke et al. on Apr. 1, 2008, discloses a container for supporting a brassiere or a similar garment for cleaning and storage includes opposed flat plate members connected by a hinge, and opposed container cup members connected to the respective plate members at hinge connections for folding the container cup members over the plate members and for folding the plate members with respect to each other to form a closed container for supporting a brassiere. The plate members include hinged support members, each having an arcuate cross shape, for supporting brassiere cups between the plate members and the container cup members. Spaced apart clips secure the brassiere straps to the plate members. Spaced apart latches releasably secure the cup members to the plate members and the plate members to each other for placing the container in a compact folded position.
[0016] U.S. Pat. No. 7,743,953, issued to Okazaki et al. on Jun. 29, 2010, discloses a brassiere holder that includes two cup receiving portions, a connecting portion and a hook portion. When the cup receiving portions are pressed from the side, the connecting portion is elastically deformed to allow the two cup receiving portions to be folded back on each other such that a part of a flange portion of the two cup receiving portions is brought into contact with the other part of the flange portion and a gap gradually increasing toward the upper side is formed between the two cup receiving portions.
[0017] Traditional approaches to cleaning and drying delicate items rely on confining such items in a structure moulded to conform to the shape of the item. Other approaches have included confining such items to a bag. In addition to structural and implementation limitations these approaches present with respect to, for example, front and top loaded washers and dryers, and washers with a centrally located agitator, some approaches also tend to limit the surface area of the item being exposed to the cleaning agent, soap, detergent, water, etc. Indeed, some approaches even seem to work against the washer and dryer by hindering and limiting the cleaning and drying potential offered by such appliances. Yet other approaches tend to only accomplish separating the delicate items from the remainder, but leave unaddressed how such delicate items interact with each other within the confines of a bag.
[0018] There is therefore a need in the art for approaches that minimize the wear and tear of delicate items without any significant reduction in the cleansing or drying of said items. Accordingly, it is desirable to provide methods, systems, and media that overcome these and other deficiencies of the prior art.
BRIEF SUMMARY
[0019] In accordance with various embodiments, systems, methods and devices for washing delicate items are provided.
[0020] In certain embodiments, the assembly comprises a clothes line assembly comprising an elongated line made from a stretchable material, e.g., a bungee cord, the elongated line terminating on both the distal and proximal ends in a connector. Each connector is configured and dimensioned for releasable attachment to, for example, a water spin drain hole in the wall of the tub of a standard washing machine. Each connector may either be affixed or attached to an end of the elongated line. The assembly described herein is further comprised of clips or brackets configured for releasable securing, for example, a bra to the elongated line.
[0021] In certain embodiments, the product may be secured within a plastic container which is then secured to the elongated line, either by securing means of the plastic container or by separate clips/brackets.
[0022] In accordance with some embodiments, the assembly need not be run diametrically across the cylinder, particularly when, for example, an agitator blocks the path. In such instances, or when desired by the user, the assembly described herein is capable of being secured to the interior of the appliance in a cord like fashion that does not pass through the centre.
[0023] In accordance with some embodiments, mechanisms are provided to address the problem of tangled bra straps during washing using a washing machine.
[0024] It should be noted that the described assembly is reusable and provides a cleaning and drying system that is economical to manufacture. In addition, the described assembly also secures the product without unduly limiting the surface area exposed to the cleansing liquid, soap, detergent, fabric softener, etc.
[0025] There has thus been outlined, rather broadly, the features of the present invention in order that the detailed description that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are additional features of the invention that will be described and which will form the subject matter of the claims. Additional aspects and advantages of the present invention will be apparent from the following detailed description of an exemplary embodiment which is illustrated in the accompanying 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 are for the purpose of description and should not be regarded as limiting.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIG. 1 is an illustration of an assembly for reducing wear and tear of products within an appliance, showing an exemplary use of the assembly according to certain embodiments of the disclosed subject matter.
[0027] FIG. 2 is an illustration of an assembly for reducing wear and tear of products within an appliance, showing the elements of assembly 100 , according to certain embodiments of the disclosed subject matter.
[0028] FIGS. 3-5 illustrate three connectors suitable for use with an assembly for reducing wear and tear of products within an appliance, according to certain embodiments of the disclosed subject matter.
[0029] FIG. 6 is an illustration of a holding element suitable for use with an assembly for reducing wear and tear of products within an appliance, according to certain embodiments of the disclosed subject matter.
[0030] FIG. 7 is an illustration of another holding element suitable for use with an assembly for reducing wear and tear of products within an appliance, according to certain embodiments of the disclosed subject matter.
[0031] FIG. 8 is an illustration of yet another holding element suitable for use with an assembly for reducing wear and tear of products within an appliance, according to certain embodiments of the disclosed subject matter.
DETAILED DESCRIPTION
[0032] It will be understood by one of ordinary skill in the art that the embodiments described herein may be adapted and modified as is appropriate for the application being addressed and that the embodiments described in more detail below may be employed in other suitable applications, and that such other additions and modifications will not depart from the scope hereof.
[0033] FIG. 1 is an illustration of an assembly for reducing wear and tear of products within an appliance, showing an exemplary use of the assembly according to certain embodiments of the disclosed subject matter. FIG. 1 shows an appliance 200 , which is a front-loading clothes washer and dryer. Appliance 200 performs a wash cycle for washing clothes and a dry cycle for drying clothes. Appliance 200 includes a tub 210 , which holds the clothes for washing and drying. Tub 210 includes a plurality of holes 220 along its surface for allowing circulation and drainage of water when appliance 200 is performing the wash cycle. Holes 220 further allow drainage of water and circulation of air and water vapour during the period when appliance 200 is performing the dry cycle. While various embodiments of the disclosed subject matter have been illustrated with the example of a clothes washer and dryer, it would be apparent to one skilled in the art that the principles and teachings of the disclosed subject matter may be applied to various other appliances, such as but not limited to front-loading or top-loading washing machines, clothes dryers, dishwashers, etc.
[0034] FIG. 1 further shows assembly 100 for reducing wear and tear of a product 300 within appliance 200 . In various embodiments, product 300 may be a delicate item susceptible to wear and tear within appliance 200 . Product 300 shown in FIG. 1 is a brassiere, which includes delicate parts such as cups, underwires, padding, etc., and is therefore particularly prone to damage and/or deformation during washing and drying. The brassiere also includes straps 310 , which are prone to entanglement during washing and drying in appliance 200 , thereby forming knots that are typically untangled manually after the washing and drying cycle. Such manual disentanglement is often tedious and time consuming. Further, the entanglement and subsequent disentanglement may also cause damage to the delicate parts of the brassiere and reduce its lifespan. While various embodiments of the disclosed subject matter have been illustrated in the context of a brassiere, it would be apparent to one skilled in the art that the principles and teachings of the disclosed subject matter may be applied to various other products or delicate items, such as but not limited to other lingerie items, prosthetic devices, and etc.
[0035] Assembly 100 includes an elongated member 110 , first and second connectors 120 (not shown), and at least one holding element 130 . First and second connectors 120 are attached to a proximal and distal end of elongated member 110 respectively. Connectors 120 connect elongated member 110 to parts of appliance 200 . In various embodiments, connectors 120 are inserted into first and second holes 220 of tub 210 to connect elongated member 110 to appliance 200 . While various embodiments have been described with the example of connectors 120 that affix to holes 220 of tub 210 , it will be apparent to one skilled in the art that other mechanisms for connecting elongated member 110 to appliance 200 , such as vacuum cups/grippers, adhesives, hooks, screws, etc. may be used without deviating from the spirit and scope of the disclosed subject matter. Holding elements 130 are removably mounted on elongated member 110 and releasably hold product 300 . Assembly 100 holds product 300 within appliance 200 in a manner that significantly mitigates the damage caused to product 300 during the operation of appliance 200 . In various embodiments, assembly 100 serves to distance product 300 from moving parts of appliance 200 , or areas within appliance 200 experiencing extreme temperatures that may damage product 300 , or from other objects within appliance 200 that may damage product 300 during operation.
[0036] FIG. 2 is an illustration of an assembly for reducing wear and tear of products within an appliance, showing the elements of assembly 100 , according to certain embodiments of the disclosed subject matter. FIG. 2 shows elongated member 110 , connectors 120 , and holding elements 130 . In various embodiments, elongated member 110 is made of an extensible material, such as extensible cord or a bungee cord. In another embodiment, elongated member is an extensible telescopic rod. The extensibility of elongated member 110 allows a user to easily adapt it for use with a variety of appliances 200 with different geometries, as well as for different use configurations within appliance 200 . Connectors 120 may be, without limitation, hooks, clamps, vacuum cups, adhesive pads, or other suitable fastening mechanisms. In various embodiments, connectors 120 removably connect elongated member 110 to appliance 200 .
[0037] Holding elements 130 hold product 300 to reduce wear and tear suffered by it during operation of appliance 200 . Holding element 130 includes a mechanism for holding product 300 , and a mechanism for mounting itself on elongated member 110 . In various embodiments, holding element 130 has a jaw-like structure for gripping product 300 securely. In addition, in various embodiments, holding element 130 has smooth and rounded edges to further ameliorate the wear and tear of product 300 .
[0038] FIGS. 3-5 illustrate three connectors suitable for use with an assembly for reducing wear and tear of products within an appliance, according to certain embodiments of the disclosed subject matter. FIG. 3 shows a hook connector 310 , an embodiment of connector 120 . Hook connector 310 is attached to an end of elongated member 110 and inserted through hole 220 to connect elongated member 110 to tub 210 as shown. FIG. 4 shows a screw connector 410 , another embodiment of connector 120 . Screw connector 410 is attached to an end of elongated member 110 and inserted and screwed into hole 220 to connect elongated member 110 to tub 210 as shown. Screw connector 410 has a substantially helical shape, with increasing radius as shown. Such a shape allows ease of insertion into hole 220 , while still providing a snug and secure fit between screw connector 410 and tub 210 . FIG. 5 shows a snap-on connector 510 , another embodiment of connector 120 . Snap-on connector 510 is attached to an end of elongated member 110 and inserted and snapped into position in hole 220 to connect elongated member 110 to tub 210 as shown.
[0039] FIG. 6 is an illustration of a holding element suitable for use with an assembly for reducing wear and tear of products within an appliance, according to certain embodiments of the disclosed subject matter. FIG. 6 shows a structure of holding element 130 that will secure a product 300 while allowing adequate water and air flow to product 300 to facilitate washing and drying. Holding element 130 shown in the figure has a jaw-like structure, and includes an upper lip 602 and a lower lip 604 . Upper lip 602 and lower lip 604 are connected by hinge 606 . Lips 602 and 604 are shaped to form an elongated member channel 608 , which houses elongated member 110 during use of holding element 130 . Further, lips 602 and 604 have interlocks 610 that lock into each other when lips 602 and 604 are pressed shut, and keep them shut during use. Upper lip 602 has a convex surface 612 , and lower lip 604 has a concave surface 614 . Surfaces 612 and 614 are shaped to fit substantially snugly with each other when lips 602 and 604 are pressed shut. In various embodiments, at least one of surfaces 612 and 614 is made of compressible material, such as rubber. Lower lip 604 further includes one or more transverse bands 616 , which may be used to weave with a part of product 300 to secure product 300 with holding element 130 . In certain embodiments, transverse bands 616 may be strong rubber bands. Lips 602 and 604 further have recesses 618 that provide space for housing the portion of product 300 that connects the parts retained within holding element 130 and the remainder of product 300 . In certain embodiments, recesses 618 have a smooth and rounded surface, and are composed of soft material, to minimize wear and tear to product 300 .
[0040] For washing and drying of product 300 , for example a brassiere, a part of product 300 , for example the straps 310 of the brassiere, may be weaved into transverse bands 616 before snapping upper lip 602 and lower lip 604 shut to firmly hold the brassiere. The shape of surfaces 612 and 614 , in conjunction with the compressible material used therein, provides a firm grip over straps 310 to withstand the strains of washing and drying, while minimizing the risk of wear and tear. Recesses 618 house the remaining portion of straps 310 and/or the connection between the brassiere and straps 310 . As a result, only a small part of product 300 is covered by holding element 130 , and a majority of the surface area of product 300 is directly accessible to the washing liquid/water and air for effective washing and drying.
[0041] Holding element 130 further includes circulation holes 620 , which allow washing fluids and air to circulate within holding element 130 , thereby providing for washing and drying of portions of product 300 retained within holding element 130 as well. In various embodiments, finger tabs 622 are provided in at least one of lips 602 and 604 to facilitate easy opening of holding element 130 .
[0042] In certain embodiments, hinge 606 includes a locking mechanism. The locking mechanism, when in an unlocked position, allows lips 602 and 604 to rotate along hinge 606 relative to each other. Once the locking mechanism is turned to a locked position, upper lip 602 and lower lip 604 are securely abutted against each other, and hold product 300 as well as elongated member 110 firmly.
[0043] FIG. 7 is an illustration of another holding element suitable for use with an assembly for reducing wear and tear of products within an appliance, according to certain embodiments of the disclosed subject matter. The figure shows a holding element 130 that includes a hanging hook 702 . Hanging hook 702 is pivotally connected with a hinge 704 , and can rotate along the axis of the hinge, as shown by rotating positions 702 a and 702 b of hanging hook 702 . Hanging hook 702 may be used to hang product 300 in order to, for example, air dry or store product 300 . During use within appliance 200 , hanging hook may be rotated to recede into a hook cavity 706 in a lip 708 , to prevent damage during operation of appliance 200 .
[0044] FIG. 8 is an illustration of yet another holding element suitable for use with an assembly for reducing wear and tear of products within an appliance, according to certain embodiments of the disclosed subject matter. Holding element 130 shown in the figure includes an upper lip 802 and a lower lip 804 joined together at joint 806 . Lips 802 and 804 have circulation holes 808 , which allow washing fluids and air to circulate within holding element 130 , thereby providing for washing and drying of portions of product 300 retained within holding element 130 as well. In various embodiments, lips 802 and 804 are made of soft, strong, and flexible material such as polymers. Lips 802 and 804 may be closed shut by the use of closing elements 810 provided substantially along the peripheries of lips 802 and 804 . In various embodiments, closing elements 810 are, without limitation, patches of Velcro® hooks and loops, interlocking Ziploc® type members, or other mechanisms for reversible and reusable fastening.
[0045] Holding element 130 also includes a perforation 812 to facilitate better circulation of washing fluids and air within the holding element 130 . In certain embodiments, perforation 812 may also be used to removably attach holding element 130 with elongated member 110 . Further, in certain embodiments, elongated member 110 may be encircled by upper lip 802 and lower lip 804 once they have been closed using closing elements 810 .
[0046] Recesses 814 are provided along the periphery of holding element 130 to provide space to accommodate the connecting portion of product 300 . Holding element 130 further includes one or more binders 816 attached to lower lip 804 . Binders 816 are wound around a loop 818 as shown, and include fastening elements 820 for securing binders 816 .
[0047] In an exemplary use case in accordance with certain embodiments, binders 816 are tightened over brassiere straps 310 woven through them, and secured using fastening elements 820 . The remaining portion of straps 310 exits holding element 130 through recesses 814 . Elongated member 110 is attached to holding element 130 by encircling it within lips 802 and 804 . Alternatively, a portion of elongated member 110 may be received in holding element 130 through perforation 812 to achieve the desired attachment. The brassiere is thus suspended from elongated member 110 using holding element 130 inside tub 210 for the washing and drying cycle for the brassiere. Circulation holes 808 and perforation 812 provide for circulation of washing fluids and air within holding element 130 to enable cleaning and drying of straps 310 retained inside holding element 130 .
[0048] Although the invention has been described and illustrated in the foregoing illustrative embodiments, it is understood that the present disclosure has been made only by way of example, and that numerous changes in the details of implementation of the invention can be made without departing from the spirit and scope of the invention, which is only limited by the claims which follow. Features of the disclosed embodiments can be combined and rearranged in various ways.
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Systems, methods and devices for washing delicate items are provided. In accordance with some embodiments, an assembly for reducing wear and tear of products within an appliance is provided. The assembly comprising an elongated member having distal and proximal connectors that are secured to receiving parts of the appliance, and having least one holding element that is removably mounted along the length of the elongated member and is configured to releasably hold at least one product.
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FIELD OF THE DISCLOSURE
[0001] The present disclosure relates generally to semiconductor manufacturing equipment and, more particularly, to techniques for improving extracted ion beam quality using high-transparency electrodes.
BACKGROUND OF THE DISCLOSURE
[0002] Ion implantation is a process of depositing chemical species into a substrate by direct bombardment of the substrate with energized ions. In semiconductor manufacturing, ion implanters are used primarily for doping processes that alter a type and level of conductivity of target materials. A precise doping profile in an integrated circuit (IC) substrate and its thin-film structure is often crucial for proper IC performance. To achieve a desired doping profile, one or more ion species may be implanted in different doses and at different energy levels.
[0003] FIG. 1 depicts a conventional ion implanter system 100 . The ion implanter 100 includes a source power 101 , an ion source 102 , extraction electrodes 104 , a 90° magnet analyzer 106 , a first deceleration (D 1 ) stage 108 , a 70° magnet analyzer 110 , and a second deceleration (D 2 ) stage 112 . The D 1 and D 2 deceleration stages (also known as “deceleration lenses”) each comprising multiple electrodes with a defined aperture to allow an ion beam 10 to pass therethrough. By applying different combinations of voltage potentials to the multiple electrodes, the D 1 and D 2 deceleration lenses can manipulate ion energies and cause the ion beam 10 to hit a target workpiece 114 at a desired energy. A number of measurement devices 116 (e.g., a dose control Faraday cup, a traveling Faraday cup, or a setup Faraday cup) may be used to monitor and control the ion beam conditions.
[0004] The ion source 102 and extraction electrodes 104 are critical components of the ion implanter system 100 . The ion source 102 and extraction electrodes 104 are required to generate a stable and reliable ion beam 10 for a variety of different ion species and extraction voltages.
[0005] FIG. 2 depicts a conventional ion source and extraction electrode configuration 200 . Referring to FIG. 2 , which is a schematic diagram of the conventional ion source and extraction electrode configuration 200 , the ion source 102 is provided in a housing 201 . The ion source 102 has a faceplate 203 , which has an aperture from which the extraction electrodes 104 may extract ions from plasma in the ion source 102 . The extraction electrodes 104 include a suppression electrode 205 and a ground electrode 207 . As depicted in FIG. 2 , the suppression electrode 205 and the ground electrode 207 are often double-slotted with different slot dimensions, large slot for high-energy implant application (e.g., >20 keV), and small slot for low-energy application (e.g., <20 keV).
[0006] It should be appreciated that arrows are shown in FIG. 2 to represent vacuum pumping directions. Vacuum pumping, as depicted by the arrows, is required to provide pressure level low enough for stable beam-extraction operation between the suppression electrode 205 and the ground electrode 207 for ion beam extraction.
[0007] FIGS. 3A-3B depict a conventional ground electrode 207 . FIG. 3A depicts a three-dimensional view 300 A of a conventional ground electrode 207 . In this example, the ground electrode 207 is double-slotted, having a first slot 309 a and a second slot 309 b. FIG. 3B depicts a cross-sectional view 300 B of the conventional ground electrode 207 . The ground electrode 207 has a overall height H, which includes a base height b and a slot height a. The ground electrode 207 also has a base angle α and a slot angle β. In the conventional ground electrode 207 , the base height b is greater than the slot height a and the base-to-slot height ratio may be expressed as b/a>1.
[0008] A problem that currently exists in conventional ion implantation is that as extraction current from the ion source 102 increases, undesirable beam shape may be observed at the target workpiece 114 . This undesirable beam shape may provide “beam wiggles” that ultimately reduce uniformity in the ion beam 10 . Although this problem may be associated with plasma instability and/or plasma oscillation inside the ion source 102 , the extraction electrodes 104 play a critical role and may add to the problem. For example, mechanical imperfections and high background pressure at the extraction electrodes 104 may greatly amplify the “beam wiggles” and degrade ion beam quality.
[0009] FIG. 4 depicts an illustrative graph 400 of an extracted ion beam profile. In this example, a wiggle-shaped extracted ion beam profile 410 is depicted. As depicted in dotted lines, an ideal extracted ion beam profile 420 is provided. Although both the wiggle-shaped extracted ion beam profile 410 and the ideal extracted ion beam profile 420 have similar profiles, the ideal ion beam profile 420 has a smooth profile, which may be transported and tuned as a high quality ion beam at the target.
[0010] As described above, “beam wiggles” generated and/or amplified by the extraction electrodes 104 may lead to degraded beam uniformity and poor quality of the ion beam 10 at the target workpiece 114 . In order to improve ion beam quality, the “beam wiggles” in the extracted ion beam profile 410 should be reduced to resemble more closely the ideal extracted ion beam profile 420 . However, conventional systems and methods do not provide an adequate solution to reduce “beam wiggles” in an extracted ion beam profile.
[0011] In view of the foregoing, it may be understood that there are significant problems and shortcomings associated with current ion beam extraction technologies.
SUMMARY OF THE DISCLOSURE
[0012] Techniques for improving extracted ion beam quality using high-transparency electrodes are disclosed. In one particular exemplary embodiment, the techniques may be realized as an apparatus for ion implantation. The apparatus may comprise an ion source for generating an ion beam, wherein the ion source comprises a faceplate with an aperture for the ion beam to travel therethrough. The apparatus may also comprise a set of extraction electrodes comprising at least a suppression electrode and a high-transparency ground electrode, wherein the set of extraction electrodes may extract the ion beam from the ion source via the faceplate, and wherein the high-transparency ground electrode may be configured to optimize gas conductance between the suppression electrode and the high-transparency ground electrode for improved extracted ion beam quality.
[0013] In accordance with other aspects of this particular exemplary embodiment, the high-transparency ground electrode may be configured with an overall height H, one or more slot portions, a base angle θ, and a slot angle δ, wherein the overall height may comprise a base height y and a slot height x such that the base height y may be less than the slot height x and the base-to-slot height ratio y/x may be equal to or less than 1.
[0014] In accordance with further aspects of this particular exemplary embodiment, the base angle θ may be 20°.
[0015] In accordance with additional aspects of this particular exemplary embodiment, the base angle θ may be greater than 20°, such as 40°.
[0016] In accordance with other aspects of this particular exemplary embodiment, the high-transparency ground electrode may be a single-slot high-transparency ground electrode or a double-slot high-transparency ground electrode.
[0017] In accordance with further aspects of this particular exemplary embodiment, the ion source may be encased in a housing having a tapered configuration.
[0018] In accordance with additional aspects of this particular exemplary embodiment, the faceplate may be a protruded faceplate.
[0019] In accordance with other aspects of this particular exemplary embodiment, the suppression electrode may be a protruded suppression electrode.
[0020] In accordance with further aspects of this particular exemplary embodiment, the high-transparency ground electrode may further comprise one or more anchor portions positioned near one or more extraction slots of the high-transparency ground electrode for defining stable plasma boundaries inside of the high-transparency ground electrode.
[0021] In another particular exemplary embodiment, the techniques may be realized as a method for improving ion beam quality. The method may comprise providing an ion source comprising a plasma generator for generating an ion beam and a faceplate with an aperture for the ion beam to travel therethrough. The method may also comprise providing a set of extraction electrodes comprising at least a suppression electrode and a high-transparency ground electrode, wherein the set of extraction electrodes may extract the ion beam from the ion source via the faceplate, and wherein the high-transparency ground electrode may be configured to optimize gas conductance between the suppression electrode and the high-transparency ground electrode for improved ion beam quality.
[0022] The present disclosure will now be described in more detail with reference to exemplary embodiments thereof as shown in the accompanying drawings. While the present disclosure is described below with reference to exemplary embodiments, it should be understood that the present disclosure is not limited thereto. Those of ordinary skill in the art having access to the teachings herein will recognize additional implementations, modifications, and embodiments, as well as other fields of use, which are within the scope of the present disclosure as described herein, and with respect to which the present disclosure may be of significant utility.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] In order to facilitate a fuller understanding of the present disclosure, reference is now made to the accompanying drawings, in which like elements are referenced with like numerals. These drawings should not be construed as limiting the present disclosure, but are intended to be exemplary only.
[0024] FIG. 1 depicts a conventional ion implanter system.
[0025] FIG. 2 depicts a conventional ion source and extraction electrode configuration.
[0026] FIGS. 3A-3B depict a conventional ground electrode.
[0027] FIG. 4 depicts an illustrative graph of a wiggle-shaped extracted ion beam profile and an ideal extracted ion beam profile.
[0028] FIG. 5 depicts an ion source and extraction electrode configuration, according to an exemplary embodiment of the present disclosure.
[0029] FIGS. 6A-6B depict a double-slot high-transparency ground electrode, according to an exemplary embodiment of the present disclosure.
[0030] FIG. 7 depicts an ion source and extraction electrode configuration, according to another exemplary embodiment of the present disclosure.
[0031] FIG. 8 depicts an ion source and extraction electrode configuration, according to another exemplary embodiment of the present disclosure.
[0032] FIG. 9 depicts an ion source and extraction electrode configuration with a high-transparency ground electrode using anchors, according to another exemplary embodiment of the present disclosure.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0033] Embodiments of the present disclosure improve extracted ion beam quality by using high-transparency electrodes. More specifically, various geometric schemes and/or configurations for an ion source and extraction electrodes may provide improved vacuum characteristics for reducing “beam wiggles” in an extracted ion beam profile and improve overall ion beam quality.
[0034] FIG. 5 depicts an ion source and extraction electrode configuration 500 according to an exemplary embodiment of the present disclosure. Referring to FIG. 5 , which depicts a schematic diagram of the ion source and extraction electrode configuration 500 , an ion source 502 may be provided in a housing 501 . The ion source 502 may have a faceplate 503 that includes an aperture from which extraction electrodes 504 may extract ions from plasma inside the ion source 502 . The extraction electrodes 504 may include at least a suppression electrode 505 and a ground electrode 507 .
[0035] In some embodiments, as depicted in FIG. 5 , the suppression electrode 505 and the ground electrode 507 may be double-slotted. In this example, it should be appreciated that one slot may be for high-energy ion beam application (e.g., >20 keV) and another slot may be for low-energy ion beam application (e.g., <20 keV). However, unlike the conventional ground electrode 207 described above, the ground electrode 507 of FIG. 5 may be a high-transparency ground electrode 507 having a geometry that optimizes gas conductance in an extraction region (e.g., a region between the suppression electrode 505 and the ground electrode 507 ). It should be appreciated that large arrows are shown in FIG. 5 to represent vacuum pumping directions. As depicted by the large arrows, using the high-transparency ground electrode 507 may provide improved gas conductance in the extraction region (e.g., due to a large opening area) in a direction toward a turbo pump (not shown) (vertical) and an analyzer magnet (not shown) (horizontal).
[0036] FIGS. 6A-6B depict views of the high-transparency ground electrode 507 according to an exemplary embodiment of the present disclosure. For example, FIG. 6A depicts a three-dimensional view 600 A of the high-transparency ground electrode 507 according to an exemplary embodiment of the present disclosure. The high-transparency ground electrode 507 of FIG. 6A may be a double-slot high-transparency ground electrode 507 having a first slot 609 a and a second slot 609 b.
[0037] However, unlike the conventional ground electrode 207 described above, the double-slot high-transparency ground electrode 507 of FIGS. 6A-6B may have dimensions that provide improved gas conductance in the extraction region, especially between the suppression electrode 505 and the double-slot high-transparency ground electrode 507 . In particular, the double-slot high-transparency ground electrode 507 may have a substantially reduced base portion. FIG. 6B depicts a cross-sectional view 600 B of the double-slot high-transparency ground electrode 507 . In this example, the double-slot high-transparency ground electrode 507 may have an overall height L, which includes a base height y and a slot height x. The double-slot high-transparency ground electrode 507 may also have a base angle θ and a slot angle δ. In some embodiments, the base angle θ may be 20°. It should be appreciated that the base height y may be lesser than the slot height x. Therefore, the base-to-slot height ratio may be expressed as y/x<1. It should also be appreciated that in some embodiments, the slot angle δ may be reduced as well.
[0038] The above-described double-slot high-transparency ground electrode 507 has a geometry that may provide improved gas conductance. More specifically, the overall volume of the ground electrode 507 may be reduced and therefore provide more room for effective vacuum pumping, which may improve gas conductance. Additionally, the double-slot high-transparency ground electrode 507 may be utilized in existing systems without additional alterations and/or modifications. Thus, using the double-slot high-transparency ground electrode 507 may provide a cost-effective way to optimize gas conductance and improve extracted ion beam quality.
[0039] FIG. 7 depicts an ion source and extraction electrode configuration 700 according to another exemplary embodiment of the present disclosure. Similar to FIG. 5 , FIG. 7 depicts a schematic diagram of an ion source and extraction electrode configuration 700 . Here, an ion source 702 may be provided in a housing 701 . The ion source 702 may also have a faceplate 703 having an aperture from which extraction electrodes 704 may extract ions from plasma in the ion source 702 . The extraction electrodes 704 may include a suppression electrode 705 and a high-transparency ground electrode 707 .
[0040] However, unlike FIG. 5 , the suppression electrode 705 and the high-transparency ground electrode 707 of FIG. 7 may be single-slotted. For similar reasons stated above, such geometric configurations may optimize gas conductance in the extraction region.
[0041] It should be appreciated that large arrows are shown in FIG. 7 to represent pumping directions. As depicted by the large arrows, using the single-slotted high-transparency ground electrode 707 may provide improved gas conductance in the extraction region (e.g., between the suppression electrode 705 and the ground electrode 507 ) in a direction toward a turbo pump (not shown) (vertical) and an analyzer magnet (not shown) (horizontal). Similar to FIG. 5 , overall volume of the high-transparency ground electrode 707 may be reduced in a single-slot configuration and therefore provide more room for vacuum pumping and an improve ion beam profile.
[0042] A variety of additional geometric configurations may also be provided. For example, FIG. 8 depicts an ion source and extraction electrode configuration 800 according to another exemplary embodiment of the present disclosure. Similar to FIG. 7 , FIG. 8 depicts a schematic diagram of an ion source and extraction electrode configuration 800 . In this example, an ion source 802 may be provided in a housing 801 . The ion source 802 may also have a faceplate 803 having an aperture from which extraction electrodes 804 may extract ions from the plasma in the ion source 802 . The extraction electrodes 804 may include a suppression electrode 805 and a ground electrode 807 , which in turn may be single-slotted.
[0043] However, unlike FIG. 7 , the housing 801 , the faceplate 803 , the suppression electrode 805 , and the ground electrode 807 of FIG. 8 may each have different geometric schemes and/or configurations. For instance, the housing 801 may have a tapered configuration (e.g., a tapered top hat configuration) and each of the faceplate 803 , the suppression electrode 805 , and the ground electrode 807 may have a protruded configuration. For similar reasons stated above, these various geometric configurations, independently or altogether, may optimize gas conductance and improve an extracted ion beam profile.
[0044] The tapered housing 801 , as opposed to the conventional configuration (e.g., non-tapered configuration), may improve gas conductance between the faceplate 803 and the suppression electrode 805 . A tapered shape may provide more room for gas conductance and may therefore minimize gas pressure for improved extracted ion beam quality. The protruded faceplate 803 may also improve gas conductance between the faceplate 803 and the suppression electrode 805 .
[0045] According to an exemplary embodiment of the present disclosure, the protruded ion source faceplate 803 may be provided. In this example, rather than a conventional planar configuration, the protruded faceplate 803 may be sloped such that an extraction aperture of the protruded faceplate 803 may “protrude” towards the extraction electrodes.
[0046] It should be appreciated that while beam optics of the protruded faceplate 803 remain the same or similar to that of a conventional faceplate, the shape of the protruded faceplate 803 may provide an improved geometric scheme. Ultimately, a protruded shape may provide more space for improved gas conductance and may therefore lower gas pressure for improved extracted ion beam quality.
[0047] Referring back to FIG. 8 , protruded extraction electrodes 804 may also improve gas conductance between the faceplate 803 and the suppression electrode 805 . For example, the protruded suppression electrode 805 may extend further toward the faceplate 803 to improve gas conductance at a region between the faceplate 803 and the suppression electrode 805 .
[0048] Additionally, in this configuration, the high-transparency ground electrode 807 may be protruded and widened to improve gas conductance as well. For example, in FIG. 8 , the high-transparency ground electrode 807 may also have widened base angle θ′. In some embodiments, the widened base angle θ′ may be twice that of the base angle θ from previous embodiments. For instance, in one embodiment, base angle θ′ may be 40°. Other various embodiments may also be provided.
[0049] By using a protruded and widened high-transparency ground electrode 807 , gas conductance may be improved in the region between the suppression electrode 805 and the ground electrode 807 . It should be appreciated that improvements in gas conductance may also be provided in a (horizontal) direction toward an analyzer magnet (not shown).
[0050] It should be appreciated that anchors may also be provided at the high-transparency ground electrode 807 to alter pressure distribution in an extraction region (e.g., between the suppression electrode 805 and the high-transparency ground electrode 807 ). For example, FIG. 9 depicts an ion source and extraction electrode configuration 900 with a high-transparency ground electrode 907 using anchors 909 according to another exemplary embodiment of the present disclosure. In some embodiments the high-transparency ground electrode 907 using anchors 909 may better define stable plasma boundaries inside an extraction slot of the ground electrode 907 . In other embodiments, the high-transparency ground electrode 907 using anchors 909 may provide a pressure gradient in a downstream region of an extracted ion beam path. This may provide increased pressure between the suppression electrode 905 and the high-transparency ground electrode 907 and reduce pressure within the high-transparency ground electrode 907 and in regions further downstream.
[0051] Embodiments of the present disclosure may provide improved extracted ion beam quality by optimizing gas conductance at an ion source and extraction electrodes. These techniques may separately or conjunctively reduce “beam wiggles” in an extracted ion beam profile. In doing so, desired correction to a shape of the ion beam may be provided. More specifically, greater ion beam uniformity, reliability, and predictability may be achieved and effected for improved ion implantation process.
[0052] It should be appreciated that while certain geometries have been described (e.g., protruded shapes, sizes, changes in angles/ratios, etc.), other geometric configurations for improving gas conductance and improving ion beam quality may also be provided.
[0053] It should be appreciated that while these embodiments of the present disclosure may be depicted and described as having certain shapes, cross-sectional shapes, numbers, angles, and sizes, other various shapes, cross-sectional shapes, numbers, angles, and sizes may also be considered.
[0054] It should also be appreciated that while embodiments of the present disclosure are directed to a high-transparency electrode configuration having a single slot or a double slot, other various configurations may also be provided. For example, a high-transparency electrode configurations having smaller or larger numbers of slots (e.g., configurations having single, multiple, or segmented electrodes) may also be provided.
[0055] It should also be appreciated that operation of the geometric configurations in the embodiments described above should not be restricted to ion source and extraction electrode configurations. For example, the various techniques and geometric configurations described above may also be applied to other ion implantation components as well.
[0056] It should be also appreciated that while embodiments of the present disclosure are directed to improving gas conductance and extracted ion beam quality, other implementations may be provided as well. For example, the disclosed techniques for utilizing various geometric ion source and extraction electrode configurations may also apply to other various ion implantation systems that use electric and/or magnetic deflection or any other beam collimating systems. Other various embodiments may also be provided.
[0057] The present disclosure is not to be limited in scope by the specific embodiments described herein. Indeed, other various embodiments of and modifications to the present disclosure, in addition to those described herein, will be apparent to those of ordinary skill in the art from the foregoing description and accompanying drawings. Thus, such other embodiments and modifications are intended to fall within the scope of the present disclosure. Further, although the present disclosure has been described herein in the context of a particular implementation in a particular environment for a particular purpose, those of ordinary skill in the art will recognize that its usefulness is not limited thereto and that the present disclosure may be beneficially implemented in any number of environments for any number of purposes. Accordingly, the claims set forth below should be construed in view of the full breadth and spirit of the present disclosure as described herein.
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Techniques for improving extracted ion beam quality using high-transparency electrodes are disclosed. In one particular exemplary embodiment, the techniques may be realized as an apparatus for ion implantation. The apparatus may comprise an ion source for generating an ion beam, wherein the ion source comprises a faceplate with an aperture for the ion beam to travel therethrough. The apparatus may also comprise a set of extraction electrodes comprising at least a suppression electrode and a high-transparency ground electrode, wherein the set of extraction electrodes may extract the ion beam from the ion source via the faceplate, and wherein the high-transparency ground electrode may be configured to optimize gas conductance between the suppression electrode and the high-transparency ground electrode for improved extracted ion beam quality.
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FIELD OF THE INVENTION
This application claims priority to German Patent Application 10349968.7, filed Oct. 24, 2003.
The invention concerns a radial rotary transfer assembly comprising at least one rotor and at least one stationary part, wherein the at least one rotor has at least two axially spaced sealing surfaces and wherein two sliding rings with overall at least two sealing surfaces are arranged between the stationary part and the rotor, wherein the sealing surfaces of the sliding rings co-operate with the rotor sealing surfaces, and with at least one radial feed passage between the pairs of co-operating sealing surfaces.
BACKGROUND OF THE INVENTION
Rotary transfer assemblies for transferring fluids from a stationary machine part into a rotating machine part are known from the state of the art. The technical problem to be resolved by all rotary transfer assemblies is that of providing a sealed transition between two mutually rotating parts.
BACKGROUND OF THE INVENTION
The rotary transfer assemblies known from the state of the art are either axial transfer assemblies in which the fluid is passed along the axis of rotation or parallel thereto into the rotating machine part, or radial rotary transfer assemblies. Japanese patent specification JP 09196265 A which the present application takes as its basic starting point discloses such a radial rotary transfer assembly in which the fluid is passed from the stationary machine part into the rotating part in a direction perpendicular to the axis of rotation of the rotating part. In that respect, provided on the rotating part, also referred to hereinafter as the rotor, are two annular projections having axial sealing surfaces whose surface normals point in the direction of the axis of rotation and which extend in an annular configuration around the axis of rotation of the rotor. In that arrangement the sealing surfaces of the two annular projections face towards each other. The sealing surfaces of two sliding rings bear against the sealing surfaces of the rotor. The sliding rings are secured to the stationary part to prevent them from rotating with the rotor and their sealing surfaces are pressed against the sealing surfaces of the rotor by means of springs which are supported against a portion of the stationary part. The fluid is fed through a duct between the two sliding rings in a direction perpendicular to the axis of rotation of the rotor. The fluid is thus prevented from escaping by means of the sealing surfaces, which bear flat against each other, of the rotor and the two sealing rings, and by seals between the stationary part and the sliding rings.
The rotary transfer assembly known from JP 09196165 A is of a very complex and bulky structure. The part which carries the sliding sealing surfaces and which is connected to the shaft comprises two axially spaced rotor rings, with each of which is associated a respective sliding ring. The rotor rings have to be fixed on the shaft in sealed relationship. Associated with each rotor ring is its own sliding ring which admittedly does not rotate therewith but which is arranged on the shaft in an axially floating and resiliently biased condition in order always to ensure sealing contact in respect of its sliding sealing surfaces, irrespective of any component and assembly tolerances. For mounting and supporting the sliding rings the stationary part has a radially inwardly projecting flange which is arranged between the sliding rings and which presses the sliding rings against the rotor ring by way of springs. That structure takes up a relatively large amount of space both in the axial and also the radial direction.
Radial (and also axial) rotary transfer assemblies are used inter alia for the internal coolant feed in machine tools. It will be noted that a disadvantage of those rotary transfer assemblies is that they are relatively bulky and correspondingly take up space on a tool spindle. That is a nuisance in particular in modern machining centers which in any case require space for tool magazines and turret heads. Retro-fitting a coolant feed by replacing a spindle without devices for the coolant feed by a spindle with corresponding devices is often not viable because of the space additionally required for the rotary transfer assembly.
In comparison with that state of the art, the object of the present invention is to structurally design a radial rotary transfer assembly in such a way that the installation thereof in machining centers and retro-fitment thereof on existing apparatuses is simplified and does not fail because of the small space available.
SUMMARY OF THE INVENTION
That object is attained by the provision of a radial rotary transfer assembly comprising at least one rotor and at least one stationary part, wherein the at least one rotor has at least two sealing surfaces and wherein two sliding rings with overall at least two sealing surfaces are arranged between the stationary part and the rotor, wherein the sealing surfaces of the sliding rings co-operate with the rotor sealing surfaces, and with at least one radial feed passage between the pairs of co-operating sealing surfaces, wherein the normals to the sealing surfaces of the rotor face axially away from each other, wherein the normals to the sealing surfaces of the sliding rings are directed axially towards each other.
In this configuration the sliding sealing surfaces of the rotor can be arranged on one and the same component and a particular advantage with this structure is that it can be afforded with a reduced axial height.
A particularly preferred embodiment of the invention is one in which the axial height, that is to say the dimension of the rotary transfer assembly in a direction parallel to the axis of rotation of the rotor, is less than 40 mm, preferably less than 20 mm, and particularly preferably is 18 mm. By suitable optimisation of the individual components, with current nominal diameters of corresponding shafts of between 20 mm and about 100 mm, that can be readily achieved on the basis of the structure according to the invention.
Such a small axial structural height permits installation in machine tools directly between the spindle bearings even when there is a short distance between the bearings of the shaft, and therefore does not require any additional space at all. By virtue of their being arranged between the bearings, it is appropriate if the rotary transfer assemblies used at those locations are completely leak-free in order not to adversely affect the adjacent bearings.
Therefore, in order to prevent adjacent components from being adversely affected, it is desirable if the leakage spaces of the rotary transfer assembly, which are axially outside the sliding ring seals, are sealed off with annular leakage space seals which press against the shaft.
In general terms, it is advantageous if the ratio of the diameter of the shaft to the axial height of the rotary transfer assembly is greater than 1, preferably greater than 1.5 and particularly preferably greater than 2. That ensures comparatively small installation dimensions of the rotary transfer assemblies, even for large shaft diameters.
It is desirable if the maximum ratio between the radial thickness of the rotary transfer assembly and the diameter of the shaft is less than ⅓, preferably less than ⅕ and particularly preferably less than ⅙. In that way the radial installation dimension is maintained within limits even when comparatively large shafts are involved.
It is further desirable if the rotor is made in one piece. That saves on time and costs in production and in particular in assembly of the rotor.
A preferred embodiment of the invention is one in which the rotor has an annular projection whose ends or parts thereof form the sealing surfaces. As both sealing surfaces are part of the annular projection, less space is taken up than when using a respective carrier for each sealing surface. In addition the annular projection can be of a relatively thin configuration in the axial direction as the sealing surfaces lie on the oppositely disposed cover surfaces of the annular projection so that the forces exerted on the sealing surfaces compensate each other. That also saves on axial structural height. It will be noted that the axial height of the projection must be sufficient also to be able to dispose between the sliding sealing surfaces which are formed by the ends of the projection, a radial bore or a passage which can also be of a non-round, narrow cross-section, for example a slot.
In an alternative embodiment of the invention the rotor is of a multi-part structure, comprising at least one core and at least one ring pushed thereon. In that case the ends of the pushed-on ring or parts thereof form the sealing surfaces. This design configuration is advantageous as it allows simpler manufacture and assembly of the rotor. In that arrangement, the pushed-on ring preferably forms the annular projection or has the annular projection on which the axial sealing surfaces are arranged.
It is particularly advantageous in that respect if the at least one pushed-on ring is connected to the at least one core by way of at least one entrainment pin. In that way the rotary movements of the core and the pushed-on ring are coupled to each other.
A particularly preferred embodiment of the invention is one in which the stationary part is of the cross-section of a U-shaped profile and forms an annularly peripherally extending clamp, wherein the limbs of the U-shaped profile axially embrace from the outside the sliding rings and the rotor or parts thereof. That affords a particularly compact structural shape.
In that respect it is desirable if the stationary part comprises a ring of an L-shaped profile cross-section and a ring which is fixed thereto and which supplements the L-shaped profile to form a U-shaped profile. In that way the stationary part, except for the ring, can be made in one piece. After assembly of the other parts the ring is fixed in position and supplements the L-shaped profile member to constitute a U-shaped profile member which embraces the sliding rings and the rotor or parts thereof. Preferably, at its outside, the ring has a screwthread by means of which the ring can be screwed into the L-shaped profile. Alternatively it can be fixed to the L-shaped profile with additional screws. It is equally possible to envisage a welded, soldered or adhesive connection.
Desirably in that case both the (integral) rotor and also the stationary part of the rotary transfer assembly extend axially over the full height of the rotary transfer assembly, wherein the rotor is arranged radially within the stationary part and an annular projection on the rotor radially overlaps with inwardly projecting U-limbs of the stationary part and arranged between those overlapping parts are the sliding rings of which one could also be formed integrally with the stationary part.
Preferably the sliding ring seals are hydrostatically compensated. When a sliding ring with oppositely disposed end faces of equal size has a fluid flowing therearound, which is subjected to the effect of pressure, then the forces acting on the sliding ring from both sides are of equal magnitude and the sliding ring is free of forces. The hydrostatic pressure on a sealing surface of a sliding ring, which sealing surface runs against the oppositely disposed sliding surface of a rotating part, decreases with the spacing of the fluid-filled chamber and is zero at the other end of the sliding ring. Therefore, with the same area in respect of the top and bottom sides of the sliding ring, the force on the side of the sliding surface is lower than the force on the opposite side. If that force unbalance is not compensated, the sliding ring is very firmly pressed against the second sealing surface by the pressurised fluid, in addition to the springs, and in the extreme situation can run dry and seize. That can be avoided if the sizes of the surfaces around which the fluid flows, on the top and bottom sides of the sliding ring, are such that the forces acting thereat compensate for each other, although the pressure on the sliding surfaces falls in the radial direction. In that respect it is advantageous if the sliding ring seals are hydrostatically compensated almost completely, that is to say in practice between 90% and 100%, preferably at about 95%.
For passing through specific fluids, a preferred embodiment of the invention is one in which the sliding rings are made from a technical ceramic or carbide or hard metal. Such ceramics or also carbide or hard metals are of high strength and have good sliding properties while they are subjected to only a slight amount of wear. As an alternative thereto, as is known from the state of the art, the sliding rings can be made from a steel/bronze alloy. Further features, advantages and possible uses of the present invention will be apparent from the description hereinafter of a preferred embodiment together with the accompanying drawings in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a preferred embodiment of the present invention,
FIG. 2 shows an enlarged broken-away view of the embodiment of the invention shown in FIG. 1 ,
FIG. 3 shows a second embodiment of the present invention, and
FIG. 4 shows an alternative embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The embodiment of the rotary transfer assembly according to the invention, which is shown in FIGS. 1 and 2 , comprises four essential functional elements, the stationary part 1 , the sliding rings 2 , 3 and the rotor or rotating part 4 . The stationary part 1 of the rotary transfer assembly is so designed that it forms an annularly peripherally extending clamp which at least partially embraces the other elements and holds them together. In order to permit assembly of the two sliding rings 2 , 3 and the rotor 4 and in order to support them at both sides, the upper end of the stationary part 1 is provided by a ring 5 which can be screwed in. So that no fluid can pass outwardly by way of the screwthread of the ring 5 , the screwthread is sealed off at the lower end by a peripherally extending O-ring 6 . In the illustrated embodiment the rotor 4 is in one piece and is of a substantially hollow-cylindrical shape, wherein an annular projection 7 is provided on the outside of the cylinder symmetrically at half the height. The hollow-cylindrical rotor 4 can be pushed over a hollow shaft, wherein two radially peripherally extending O-ring seals 8 , 9 seal off the rotor with respect to the shaft. If the rotor is to be fixed additionally to its seat on the O-rings 8 , 9 on the shaft, it can be fixed by adhesive or screws. The stationary part 1 and the rotor 4 are of approximately the same axial height or length and are arranged in the same radial plane. They thereby also define the overall axial height of the rotary transfer assembly.
In order to permit the fluid to flow into the shaft, the rotor in the illustrated embodiment is provided with two oppositely arranged through-flow ducts 10 , 11 which are arranged symmetrically in the center of the annular projection 7 . It will be appreciated that it is also possible to provide only one duct or a plurality of peripherally distributed ducts as the space 14 annularly surrounds the projection 7 as an interconnected volume.
In order to prevent the fluid from escaping between the rotor 4 and the shaft the O-ring seals 8 , 9 are arranged in the axial direction on both sides of the through-flow ducts 10 , 11 . The hollow cylinder of the rotor 4 is substantially of such dimensions that its outside diameter is smaller than the inside diameter of the stationary part 1 . Only the annular projection 7 projects with its outside diameter into the annular clamp formed by the stationary part 1 .
Just like the rotor 4 the stationary part 1 has through-flow ducts 12 , 13 which communicate the outside of the stationary part 1 with the internal space 14 of the clamp formed by the stationary part 1 . The fluid flows out of the internal space 14 of the clamp through the through-flow ducts 10 , 11 in the rotor 4 into the shaft, or also in the reverse direction.
In order to provide a sealing effect in respect of the internal space 14 of the stationary part 1 and the through-flow ducts 10 , 11 , 12 , 13 in relation to an external region of the rotary transfer assembly, a respective sliding ring seal is provided above and below the through-flow ducts 10 , 11 , 12 , 13 . The sliding ring seals substantially comprise two respective sliding surfaces 15 , 16 and 17 , 18 respectively which slide or run against each other. If firstly only the upper sliding ring seal is considered, it will be seen that an L-shaped sliding ring 2 is arranged between the stationary part 1 and the rotor 4 ; the sliding ring 2 is carried with a small clearance between the stationary part 1 and the rotating part 4 . One of the limbs of the L-shaped sliding ring 2 extends radially outwardly in perpendicular relationship to the axis of rotation. At the underside of its limb which is perpendicular to the axis of rotation, the sliding ring 2 has an annularly peripherally extending projection 30 whose flat lower surface 15 forms the first sealing surface of the sliding ring seal. The sealing surface 15 of the sliding ring 2 slides against a second sliding surface 16 formed by one of the cover surfaces of the annular projection 7 of the rotor 4 . A normal n 16 to the sealing surface 16 and a normal n 18 to the sealing surface 18 extend axially in opposite directions from one another. A normal n 5 to the sealing surface 15 and a normal n 17 to the sealing surface 17 extend axially toward one another. The second sliding ring seal beneath the through-flow ducts 10 , 11 , 12 , 13 has identical features to the first sliding ring seal, but it is mirrored around the axis of the through-flow ducts 10 , 11 , 12 , 13 . So that the sealing surfaces 15 , 16 and 17 , 18 respectively which slide against each other can have a sealing effect, the sliding rings 2 , 3 are pressed against the sealing surfaces 16 , 18 of the annular projection 7 by springs 19 , 20 which are distributed around the periphery of the seals and which are supported against the stationary part 1 . The second sides of the L-shaped sliding rings 2 , 3 are sealed in relation to the stationary part 1 , by means of annular seals 21 , 22 . In that arrangement, the sealing rings 21 , 22 are arranged at the limbs of the L-shaped sliding rings 2 , 3 , those limbs being parallel to the axis of rotation. The sealing rings 21 , 22 are of a substantially U-shaped cross-section so that the sliding rings 2 , 3 can be easily displaced along the sealing rings 21 , 22 . In order to prevent the sliding rings 2 , 3 from being rotationally entrained with the rotor 4 , provided on the stationary part 1 are pins 23 , 24 which project from the upper and lower limbs respectively of the stationary part 1 into the internal space 14 and engage through the sliding rings 2 , 3 so that they can no longer be rotated with respect to the stationary part 1 .
In the illustrated embodiment the sliding rings 2 , 3 are made from a technical ceramic. Those ceramics exhibit good sliding properties because they are of high strength and experience low abrasion wear.
The L-shaped configuration of the sliding rings 2 , 3 and the fact that their limbs which are directed in perpendicular relationship to the axis of rotation have the fluid flowing therearound both on the top side 27 and also on the underside 28 permits hydrostatic compensation of the sliding rings 2 , 3 . The function of hydrostatic compensation can be particularly easily understood by referring to FIG. 2 . The radially outwardly disposed end 25 of the limb of the L-shaped sliding ring 3 , which limb is perpendicular to the axis of rotation, is at a sufficient spacing from the stationary part 1 so that there is formed a duct 26 through which the fluid can flow out of the internal space 14 on to the top side 27 of the limb which is perpendicular to the axis of rotation. In that respect the pressure of the fluid is constant and is of equal magnitude on all sides of the sliding ring 3 . The force which, in addition to the force of the springs 20 , acts on the surface 32 of the top side 27 of the limb which is perpendicular to the axis of rotation, is equal to the product of the pressure and the size of the upper surface 32 . A hydrostatic force also acts on the underside 28 of the limb which is perpendicular to the axis of rotation. The surface of the underside 28 is composed of two portions: the surface 29 of the limb between the radially outwardly disposed end 25 and the beginning of the annular projection 30 and the sealing surface 15 of the annular projection 30 . The force acting on the surface 29 is again equal to the product of the pressure of the fluid and the size of the surface 29 . To calculate the force on the sealing surface 15 in contrast it is necessary to take account of the fact that the pressure decreases along the sealing surface 15 with increasing distance from the internal space 14 . The force acting on the surface is then calculated as the integral of the pressure over the surface area. As the sealing surface 15 , in co-operation with the sealing surface 16 of the rotor, prevents the fluid from escaping into the region 31 behind the annular projection 30 , no hydrostatic force acts on the limb there. The force which acts overall on the underside 28 of the limb is equal to the sum of the two contributions. If the sum of the surface 25 and the sealing surface 15 1 s equal to the upper surface 27 of the limb, then effectively a force acts on the limb from above by virtue of the reduction in pressure along the sealing surface 15 . The position of the sealing surface is now so selected that the forces acting on the limb from below and from above just cancel each other out. That condition is referred to as hydrostatic compensation. In the illustrated embodiment the second sliding ring 3 is also hydrostatically compensated.
In the compensated condition the sealing rings 2 , 3 are only pressed against the sealing surfaces 16 , 18 by the springs 19 , 20 so that the sliding ring seals are prevented from running dry.
FIG. 3 shows a further embodiment of the invention in which the leakage spaces 31 ′, 33 ′, 34 ′, outside the sliding ring seals 15 ′, 16 ′ and 17 ′, 18 ′ respectively, are additionally sealed off with annular leakage space seals 35 ′, 36 ′ with respect to the area 37 ′ surrounding the rotary transfer assembly. In that way the fluid which inevitably escapes through the sliding ring seals ( 15 ′, 16 ′ and 17 ′, 18 ′ respectively) cannot pass into the region ( 37 ′) outside the rotary transfer assembly.
FIG. 4 shows an alternative configuration of the embodiment of the rotary transfer assembly as shown in FIGS. 1 and 2 , in which the rotor 4 ″ is of a two-part configuration. It is composed of a hollow-cylindrical core 38 ″ and a ring 39 ″ which is pushed on to the core 38 ″ to the half-height position so that the two parts 38 ″ and 39 ″ of the rotor 4 ″ are together of approximately the same external shape as the one-piece rotor 4 of FIGS. 1 and 2 . The pushed-on ring 39 ″ has a clearance in relation to the core 38 ″ and the transition between the two elements 38 ″, 39 ″ is sealed off in relation to the surrounding region by means of two O-rings 40 ″ and 41 ″. The pushed-on ring 39 ″ has through-flow bores for the fluid which are aligned with the bores of the core 38 ″ so that the fluid can flow into the shaft. So that the pushed-on ring 39 ″ can rotate together with the shaft and the core 38 ″ of the rotor 4 ″ it is connected to the core 38 ″ by means of two entrainment pins 42 ″ arranged on mutually opposite sides of the rotary transfer assembly. As in the case of the annular projection 7 of the one-piece rotor 4 the end faces of the pushed-on ring 39 ″ also form the sealing surfaces 16 ″, 18 ″ of the rotor 4 ″.
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A radial rotary transfer assembly including at least one rotor ( 4 ) and at least one stationary part ( 1 ) The rotor ( 4 ) has at least two sealing surfaces ( 16, 18 ). Two sliding rings ( 2, 3 ) having at least two sealing surfaces ( 15, 17 ) are arranged between the stationary part and the rotor. The sealing surfaces ( 15, 17 ) of the sliding rings ( 2, 3 ) co-operate with the rotor sealing surfaces ( 16, 18 ), and with at least one radial through-flow duct ( 10 ) between the pairs ( 15, 16; 17, 18 ) of co-operating sealing surfaces. In order to structurally design a radial rotary transfer assembly in such a way that the installation thereof in matching centers and retro-fitment thereof on existing apparatuses is simplified and does not fail because of the small space available it is proposed in accordance with the invention that the normals (n 16 , n 18 ) to the sealing surfaces of the rotor ( 4 ) face axially away from each other, wherein the normals (n 15 , n 17 ) to the sealing surfaces of the sliding rings ( 2, 3 ) are directed axially towards each other.
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FIELD OF THE INVENTION
The present invention relates to an injectable pharmaceutical preparation containing human growth hormone, and, in particular, to a pharmaceutical preparation in the form of a solution containing human growth hormone.
BACKGROUND OF THE INVENTION
Human growth hormone (abbreviated to "hGH") is a single chain polypeptide hormone, the naturally occurring type of which consists of 191 amino acid residues. hGH usually occurs in a biologically active monomer form, but is known to aggregate into dimers and then polymers under thermal stress or mechanical stress such as shaking imposed on its pharmaceutical preparation, leading to a loss of its biological activity (Becker, G. W. et al.(1987) Biotechnol. Appl. Biochem.,9, p.478).
On the other hand, it is known that long-term storage of a hGH aqueous solution causes a gradual production of a deamidation products while less forming polymerization products of hGH. The deamidated hGH, although having no alteration in its biological activity (Becker,G. W. et al.(1988) Biotechnol. Appl. Biochem., 10, p.326), is undesirable in a pharmaceutical product as its presence is thought to imply declining qualities, and its allowable content is thus usually provided by the specification.
It is also generally known that the denaturation of hGH by aggregation occurs mainly under physical stresses, while its denaturation by deamidation occurs mainly under chemical stresses.
Due to these problems, an optimal aqueous preparation of hGH has never been developed, and thus lyophilized preparations are common which are dissolved prior to injection.
As treatment with hGH to alleviate dwarfism takes a long period of years, self-injection is allowed and generally conducted at home from the start of its administration. When using a lyophilized preparation of hGH, the preparation is dissolved in an attached solvent and then injected subcutaneously or intramuscularly by the patient himself (usually a child) or his family members. Thus, it is the patient or his family members that carry out the dissolution procedure of the lyophilized preparation. Therefore, it is necessary for a physician in charge to give an adequate guidance as to how to dissolve it in order to avoid formation of aggregation products which leads to reduction of biological activity of the hGH. Their product inserts also contain cautions and instructions that hGH should be dissolved with a gentle circular motion.
As aggregates formation has also been noted in production steps of lyophilized preparations, various attempts have been made to suppress aggregates formation. However, there still are eager needs for development of more easily handled, stable preparations than the usual types of preparations which are dissolved prior to use. Recently, a kit type preparation with an associated syringe has come into use. But it has a complex structure so that dissolution of the lyophilized hGH is effected within the syringe, and it therefore makes it necessary to give especially careful and thorough explanation to the patient or his family on how to use it. Also, risks of unforeseeable erroneous handling cannot be cleared off.
As hGH is thus commonly injected at home by the patient or his family, provision of an aqueous form hGH preparation, in which dissolution procedure is eliminated, would promote convenience. Such a proper form of aqueous preparation would serve to ease the burden imposed on the patient and his family because it can be handled easily without the need of structurally complex devices employed in usual two-chamber type products requiring dissolution prior to use, e.g., a pen-type product including lyophilized hGH and a solvent which are separated by a partition.
There are following predominant patent applications addressed to hGH aqueous preparations.
CABI, in Unexamined Patent Publication No. 508156/1994 (hereinafter referred to as "CABI publication"), discloses an injectable composition of hGH or its active analogues with a pH of 5-7.5 and containing 2-50 mM citric acid as a buffering agent. It is stated in the same publication that better stability has been obtained by employing citrate than phosphate and that pH of about 6.0-7.0 is relatively preferable.
The above CABI publication teaches that the preparation set forth therein is stable for at least 12 months. In the same publication, however, "being stable" with regard to the monomer is defined as keeping the content not less than 85% of initial. Considering that specifications on the monomer content is generally considered to be not less than 90%, that preparation by CABI hardly seems to have sufficient stability.
On the other hand, through studies for improvement of quality and stability, the present inventors have also found, separately from the above disclosure by CABI, that pH is a crucial factor in the production of hGH preparation in the form of a solution, that use of a buffering agent which can maintain the preferable pH of 5-7, more preferable pH of 5.5-6.5, and that citrate, for example, is effective as such a buffering agent (Unexamined Patent Publication No. 92125/1996).
On the other hand, Genentech Inc. describes, in Unexamined Patent Publication No. 509719/1995 (hereinafter referred to as the "Genentech publication"), a liquid form hGH preparation comprising hGH, mannitol, a buffer and a nonionic surfactant. Citrate buffer is exemplified in that publication as being preferable.
Further, in Unexamined Patent Publication No. 507497/1993, Novo Nordisk Pharma describes a preparation which is produced first by crystallizing hGH by addition of acetone or ethanol in the presence of a divalent cation, e.g. Zn 2+ , lyophilizing the crystals and putting the dried crystals into a pH 6.1-6.2 suspension comprising, e.g., phosphate, zinc acetate, glycerol, and benzylalcohol. In that publication, 6-month stability tests results at 22-24° C. are reported for the suspension made of hGH crystals, using ion-exchange HPLC for patterns of deamidation and decomposition and GPC for content of dimers and polymers, respectively. It is reported that even after 6 months the content of desamide products in the preparation was 5.0%, didesamide products 1.8%, dimers 1.2% and polymers 0.3% preparation, any of which were lower than the stability test results with the solutions reconstructed from usual lyophilized preparations. The same publication states that Zn 2+ is essential in crystallization to obtain large crystals. In addition, in spite that a water-soluble solvent such as acetone or ethanol is required in the crystallization of hGH, no mention is given to any alteration in secondary or higher structures of hGH crystals in the suspension, thus leaving points unclarified.
Acetone and ethanol are often used in purification of proteins to obtain them in precipitation. This method makes use of the lower solubility of proteins to organic solvents. Though the concentration of such organic solvents in the same publication are lower than those used for making proteins precipitate, they would not be preferable for a pharmaceutical preparation administered to a human.
Upon this background, the present inventors pursued further research for an improved aqueous hGH preparation. In the process of our research, a variety of aqueous hGH preparations in liquid state were made using citrate buffer in accordance with what is described in the above unexamined patent publication by the present inventors and the CABI publication, and tests were conducted for their stability for a variety of time periods. It was then noted that any of these preparations developed slightly visible fine particles which were distinguished from aggregates. The fine particles were removable with a 0.22 μm filter, for example, but could be found again after a long-term storage or under such a stress as shaking. As formation of such fine particles would be problematic in quality with a pharmaceutical product, development of a new aqueous preparation was needed in which formation of such particles is suppressed.
On the other hand, while citrates are widely used in injectable preparations as buffering agents in slightly to weakly acidic conditions, it has been reported that they cause pain when the solution is injected subcutaneously or intramuscularly as is the case of the hGH (Unexamined Patent Publication No. 510031/94). The present inventors themselves also tested the preparations produced in accordance with the descriptions in the above CABI publication and above Unexamined Patent Publications by the present inventors, and found that these citrate-containing hGH injections cause substantial pain when the solution is infused.
Unlike stability problems of a preparation, the pain upon infusion is not a significant problem from the viewpoint of quality of the preparation. However, considering that a hGH preparation is injected on a frequent basis for a log period of time and that the patients of interest are children, and in order to ease the pain in the patients and, at the same time, thereby assuring compliance, it naturally is desired that the injectable solution itself would cause no pain. There is so far no preparation actually used in treatment and that causes no pain in the patients upon infusion of the composition. Therefore, in light of pain upon infusion, further room for an improvement is left in any of the preparations described in the above CABI publication and the Genentech publication (the latter describes citrate buffer as being preferable), as well as in the preparation according to the above patent application by the present inventors. Elimination or reduction of pain would be beneficial to the patients.
The first objective of the present invention is to solve the above stability problems of a hGH aqueous preparation for injection, i.e., to provide a stable hGH aqueous preparation in which deamination, polymerization and aggregation are sufficiently suppressed and formation of the above fine particle is also suppressed.
Another objective of the present invention is provide a hGH aqueous preparation with which pain due to its composition felt during infusion in subcutaneous or intramuscular injection is eliminated or reduced.
With a variety of hGH preparations unintentionally kept in storage before lyophilization, the present inventors found that preparations obtained by dissolving hGH in aqueous solutions the pH of which was maintained at 6 with maleate buffer or succinate buffer are comparably stable to the solution (described in Unexamined Patent Publication No. 92125/1996) in which the same pH was kept by means of citrate buffer, and that they do not produce dimers or polymers, nor do they produce deamidated products. The tests conducted and best reflecting changes in the quality of human growth hormone were: determination of monomer content on size-elimination high performance liquid chromatography (SE-HPLC), determination of the content of deamination products using high-performance liquid chromatography using a reverse-phase column, observation of general appearance and pH measurement. As a result of further intense examinations on the aqueous preparations during production, under conditions with thermal stress and after 6-month storage in cool place, maleate buffer, succinate buffer and citrate buffer were selected as having proper buffering ability out of pyruvate buffer, acetate buffer, phosphate buffer, citrate buffer, succinate buffer and maleate buffer.
It was confirmed again that by employing those proper buffers stabilization of hGH could be achieved at slightly or weakly acidic pH. However, closer observation revealed that slightly visible fine particles which scatter light and are distinguished from aggregates were detectable when preparations had been made under slightly to weakly acidic conditions. Therefore, we examined the effect of a number of compounds in search of a method to suppress the formation of the fine particles. As a results, we discovered that a low concentration of benzalkonium chloride can effectively suppress the formation of the fine particles. Further studies were carried out on the basis of this finding and it was made clear that a stable hGH aqueous preparation, in which deamination, polymerization and aggregation, as well the fine particle formation is suppressed, can be produced by employing certain formulations of aqueous preparation according to which hGH is dissolved in a solution adjusted to slightly to weakly acidic pH and containing benzalkonium chloride. The present invention was thus completed.
Meanwhile, further studies of such slightly to weakly acidic aqueous preparations led to an unexpected finding that while citrate used as a buffering agent for maintaining this pH range caused substantial pain in subcutaneous injection when the solution was infused, maleate or succinate, which are similar polycarboxylic acid salts, in contrast caused no pain substantially. On the basis of this finding, a preferable hGH-containing aqueous pharmaceutical composition has been successfully prepared which has good stability and causes no pain upon infusion.
SUMMARY OF THE INVENTION
Thus, the present invention provides an aqueous pharmaceutical composition for injection comprising human growth hormone wherein said human growth hormone is dissolved in a benzalkonium chloride-containing, slightly to weakly acidic buffered solution.
The slightly to weakly acidic pH is preferably equal to or greater than 5 and lower than 7, more preferably 5.5-6.5, further more preferably 5.75-6.25, and particularly preferably about pH6.
From the viewpoint of stability, the amount of benzalkonium chloride to be contained in the composition of the present invention may be determined within a wide range as long as the formation of fine particles can be suppressed both during preparation and long-term storage. However, the amount is preferably 0.002-0.03 mg per ml, which is the amount allowed for pharmaceutical preparations for subcutaneous or intramuscular injection, and more preferably 0.005-0.02 mg per ml.
As to buffering agents, those that are suitable to adjust the pH to lower than 7, preferably not more than 6.5, and having buffering ability to keep the pH above a lower limit that would not cause hGH precipitation. Such buffers may be advantageously used that have buffering action preferably within a range of pH5 to less than 7, more preferably 5.5-6.5. Examples of especially preferred buffering agents include maleate, succinate and citrate.
While there is no particular limitation with regard to concentration of a buffering agent as far as the buffering ability is retained, the concentration is usually 1-100 mM, more preferably 1-50 mM, further more preferably 2-20 mM. In the present specification, the term "concentration" when referred to in relation to a buffering agent is meant to indicate the total concentration of the chemical species consisting of the free organic acid that constitute the buffer and all the conjugate bases that are formed by its primary or further dissociation.
Among these buffering agents, maleate and succinate are especially advantageous as they will cause no substantial pain attributable to the composition of the solution upon subcutaneous or intra-muscular infusion of the composition according to the present invention. In particular, maleate is most preferable as it has an abundance of experiences used as a buffering agent for subcutaneous and intramuscular injections.
Therefore, the present invention further provide an aqueous pharmaceutical composition for injection comprising human growth hormone wherein said human growth hormone is dissolved in a benzalkonium chloride-containing, slightly to weakly acidic buffered solution, and wherein maleate or succinate, particularly preferably maleate, is used as the buffering agent, said composition thereby made less painful when infused. Such a composition can not only retain higher stability of hGH but also greatly ease pain felt by the patients on each administration, thus having further advantage.
DETAILED DESCRIPTION OF THE INVENTION
In the present invention, the term "human growth hormone" or its abbreviation "hGH" includes natural-type hGH consisting of 191 amino acids. Its origin is not limited and it may therefore be obtained through any route such as by genetic recombination technique or extraction from the pituitary gland. Moreover the term further includes a physiologically active type having N-terminal methionine and consisting of 192 amino acids as is obtained by gene recombination, as well as other variants in which some of the amino acids are deleted, substituted or added but having substantially comparable activity to the natural-type human growth hormone.
There is no particular limitation with regard to the amount of human growth hormone contained in the composition of the present invention. Thus, its upper limit may be the utmost amount that can be dissolved in the buffer solution employed and the lower limit may be any of the amount that is common among the preparation. Preferably, the amount of human growth hormone is up to about 10 mg per ml, the amount commonly adopted in these preparations.
In the production of the composition of the present invention, benzalkonium chloride may be used in either liquid form of solid one insofar as it is of allowable grade as an additive to pharmaceutical products.
The osmotic pressure of injections is particularly important in subcutaneous and intramuscular injection and therefore care must be taken. Injectable solutions, when hypotonic or hypertonic, would cause pain upon infusion. Usually, it is recommended that the relative osmolarity of an injectable solution be 0.9-1.6, more preferably 1.0-1.4, in comparison with physiological saline.
D-mannitol and neutral salts may be included, singularly or in combination, so that the composition of the present invention is adjusted to this relative osmolarity. D-mannitol may be included to make the relative osmolarity of 0.9-1.6, preferably 1.0-1.4, provided that its amount is 30-100 mg per ml of the composition of the present invention. Further, neutral salts, e.g. sodium chloride, may be included to make the relative osmolarity of 0.9-1.6, preferably 1.0-1.4, provided that its amount is 5-20 mg per ml of the composition of the present invention.
Because the dosage of hGH used as a pharmaceutical product is at present regulated to be 0.5 [IU] per kg body weight per week, its lyophilized preparation is sometimes injected portionwise over several times. Because of this, preservatives are often added in order to prevent contamination with bacteria and the like during storage.
It is also allowed to add preservatives to the composition of the present invention in the amount that does not affect the quality of the hGH and exhibits the preservative effect. In general, sodium benzoate is first recommended as a suitable preservative for the composition of the present invention, but benzoic acid, phenol and the like may also be used. Addition of benzyl alcohol, metacresol and methyl p-hydroxybenzoate, which are generally employed in those lyophilized hGH preparations that require dissolution prior to use, are not recommended to the composition of the present invention as they tend to cause a somewhat accelerated formation of deamidation products compared with addition of sodium benzoate, benzoic acid or phenol. The amount of a preservative may be conveniently adjusted with reference to the usually employed amount in injections. For sodium benzoate, the amount may be, for example, 0.1-5 mg, preferably 0.5-3 mg per ml of the composition of the present invention.
The composition of the present invention may contain a nonionic surfactant. A nonionic surfactant, e.g. polysorbate 20 or polysorbate 80, when added in an amount of 0.5-5 mg, more preferably 1-2 mg per ml of the composition of the present invention, can further enhance the stability, though slightly.
The production of the composition of the present invention may be conducted following conventional procedures for production of aqueous injections. The composition of the present invention is preferably kept in cool storage, particularly at 2-8° C.
As it is an aqueous solution, the composition of the present invention can be supplied in a more convenient form than the usual preparations requiring dissolution prior to use. While filling of the composition into supply containers may be conducted by a conventional method for production of single-solution-type injections, it is preferred to leave no air bubble behind after filling in order to reduce the influence of shaking during storage to thereby further ensure stability.
Stability Tests
Formation of dimers, polymers and deamidated products are well known alteration occurring in hGH. The former two can be determined by size-elimination HPLC (SE-HPLC), and the latter by reverse-phase HPLC (RP-HPLC). In addition, physicochemical determination of its content using a reference standard with known biological activity is accepted as a proper alternative determination method to the hGH biological assay, for there has been observed correlation between peak area of monomer detected on size-elimination HPLC of hGH and its biological activity (Yuki et al., Iyakuhin Kenkyu, 25: 383 (1994)). Therefore, the evaluation of hGH using these two HPLC's provides not only evaluation of monomer and deamidated products, but also determination of biological activity of hGH.
The present inventors examined the stability of the hGH aqueous preparation of the present invention by these methods of determination. As a result, while gradual formation of deamidation products were detected, calculation on the basis of the results obtained after storage at 30° C. and 40° C. revealed that the amount of deamidation products can be confined within 12% for a year under a storage condition of 4° C., pH 5.5-6.5. In addition, it was also revealed that the monomer content can be maintained at 98% or more after one-year storage at 4° C. These results indicate that the hGH aqueous pharmaceutical composition according to the present invention can be supplied as a product under a condition of being stored in cool place, and without lyophilization, which is required by the conventional products. The details of the stability studies are described below.
Determination Methods
The size-elimination HPLC and the reverse-phase HPLC were carried out in accordance with the method by Yuki et al.(Iyakuhin Kenkyu, 25: 383 (1994)).
1. Size-elimination HPLC (SE-HPLC): The following column and conditions were employed.
(1) Column: TSK gel G3000SW XL (7.8 mm×30 cm)
(2) Eluant: 0.2 M sodium phosphate buffer (pH 6.5), 0.2 M sodium chloride.
(3) Flow rate: 0.6 ml/min, Column Temp.: room temperature, Detection wavelength: 280 nm
2. Reverse-phase HPLC (RP-HPLC): The following column and conditions were employed.
(1) Column: Vydac 214TP54 (4.6 mm×25 cm)
(2) Eluant: 50 mM Tris-HCl buffer (pH 7.5):n-propanol=71:29
(3) Flow rate: 0.5 ml/min, Column Temp.: 45° C., Detection wavelength: 280 nm
Test Example 1
Buffer Solution 1
A 20 mM citrate buffer containing, per ml, 0.02 mg of benzalkonium chloride and 100 mg of D-mannitol (pH 6.0).
Buffer Solution 2
A 20 mM citrate buffer containing, per ml, 100 mg of D-mannitol (pH 6.0).
Buffer Solution 3
A 20 mM maleate buffer containing, per ml, 0.02 mg of benzalkonium chloride and 100 mg of D-mannitol (pH 6.0).
Buffer Solution 4
A 20 mM maleate buffer containing, per ml, 100 mg of D-mannitol (pH 6.0).
Buffer Solution 5
A 20 mM succinate buffer containing, per ml, 0.02 mg of benzalkonium chloride and 100 mg of D-mannitol (pH 6.0).
Buffer Solution 6
A 20 mM succinate buffer containing, per ml, 100 mg of D-mannitol (pH 6.0).
To each of the above six buffer solutions was added an equal volume of a 6.8 mg/ml natural-type hGH aqueous solution and gently mixed to give aqueous compositions 1-6, respectively (final pH 6). Then, each of the solutions was passed through a filter with a pore size of 0.22 μm and drawn into needled syringes by 1 ml each, removed of air babbles and then sealed to give samples.
A portion of each of the above aqueous preparations was subjected to horizontal shaking (amplitude 20 mm, 220 cycles/min) at 2-8° C. for 24 hours. Table 1. shows the results.
Out of the aqueous preparations, in aqueous preparations 2, 4 and 6, any of which included no benzalkonium chloride, a trace amount of fine particles were noticed to form during dispensation into the syringes and sealing. The amount of the fine particles increased by shaking. In contrast, in aqueous preparations 1,3 and 5, to which benzalkonium chloride had been added, no formation of fine particles was observed during dispensation and sealing, and, moreover, formation of fine particles was suppressed even in vigorous shaking. As for monomer content as determined by SE-HPLC or the amount of deamidation products as determined by RP-HPLC, no difference was observed between pre- and post-shaking, and the addition of benzalkonium chloride caused no difference, either. The results indicate that benzalkonium chloride is an effective stabilizer for suppressing fine particle formation in hGH-containing aqueous preparations.
TABLE 1__________________________________________________________________________Relation between stability and presence of benzalkonium chloride inbuffer solutions. During dispentsation and sealing After 24-hour shaking Monomer Amount of Monomer Amount of Aqueous content deamidation General content deamidation General preparation (%) product appearance (%) product (%) appearance__________________________________________________________________________1 99.1 2.9 Colorless and 99.1 3.0 Colorless andclear, clear,No fine particles No fine particles 2 99.2 2.9 Colorless and 99.2 3.1 Colorless andclear, clear,Fine particles Fine particlesslightly increasedobserved 3 99.2 2.8 Colorless and 99.2 2.9 Colorless andclear, clear,No fine particles No fine particles 4 99.2 2.8 Colorless and 99.2 2.9 Colorless andclear, clear,Fine particles Fine particlesslightly increasedobserved 5 99.1 2.5 Colorless and 99.1 2.7 Colorless andclear, clear,No fine particles No fine particles 6 99.2 2.4 Colorless and 99.1 2.6 Colorless andclear, clear,Fine particles Fine particlesslightly increasedobserved__________________________________________________________________________
Test Example 2
To each of 20 mM citrate buffer (pH 6.0) and maleate buffer (pH 6.0), both containing 0.002-0.1 mg per ml of benzalkonium chloride and 100 mg/ml of D-mannitol, was added an equal volume of a 6.8 mg/ml natural-type hGH aqueous solution, and gently mixed (final pH 6.0). Each of the solutions was passed through a filter with a pore size of 0.22 μm and drawn into needled syringes by 1 ml each, removed of air babbles and then sealed. They were evaluated based on their general appearance and the amount was determined of benzalkonium chloride required for effective suppression of fine particle formation. The results were as shown in Table 2. The suppression effect was observed when the amount of amount of benzalkonium chloride was 0.002-0.03 mg per ml of the preparations.
TABLE 2______________________________________Relation between benzalkonium chloride concentration and suppression of fine particle formation Concentration of benzalkonium chloride Citrate buffer Maleate buffer (mg/ml) General appearance General appearance______________________________________0.05 slightly cloudy Colorless and clear, No fine particles 0.03 Colorless and clear, Colorless and clear, No fine particles No fine particles 0.02 Colorless and clear, Colorless and clear, No fine particles No fine particles 0.01 Colorless and clear, Colorless and clear, No fine particles No fine particles 0.005 Colorless and clear, Colorless and clear, No fine particles No fine particles 0.002 Colorless and clear, Colorless and clear, No fine particles No fine particles 0.001 Colorless and clear, Colorless and clear, Fine particles observed Fine particles observed 0 Colorless and clear, Colorless and clear, Fine particles observed Fine particles observed______________________________________
Test Example 3
Each of the aqueous preparations 1,3 and 5 in Test Example 1 above was stored in incubators at 40° C. and 50° C. for 0, 3, 7, 10, 14 and 21 days, and then removed of the seal and analyzed on RP-HPLC and SE-HPLC. The results are shown in Table 3. Calculation on the results of RP-HPLC in accordance with an equation for stability estimation revealed that, although there would occur gradual formation of deamidation products, these preparations are stable for at least one year, when a provisional upper limit for deamidation products is set at 12%. On the other hand, from the result of the SE-HPLC analysis, it was concluded that the monomer content could be maintained equal to or greater than 98% even after one year storage at 2-8° C. From the comparison of samples taken at points along the storage period, no difference was observed among those types of buffers in either results from these HPLC determination.
TABLE 3__________________________________________________________________________Stability of aqueous preparations 1, 3 and 5 after storage at 40°C. and 50° C. Monomer content (%) Amount of deamidation product (%) Aqueous (SE-HPLC) (RP-HPLC)preparation Initial 7 days 14 days 21 days Initial 7 days 14 days 21 days__________________________________________________________________________Storage at 40° C.1 99.1 99.1 99.1 99.0 2.9 13.4 22.7 28.9 3 99.2 99.3 99.2 99.0 2.8 13.5 22.6 28.9 5 99.1 99.0 98.8 98.8 2.5 13.3 23.0 28.7Storage at 50° C.1 99.1 98.8 98.5 98.3 2.9 29.7 36.3 38.9 3 99.2 99.0 98.9 98.6 2.8 29.9 36.5 39.1 5 99.1 98.8 98.3 97.5 2.5 30.0 36.5 39.0__________________________________________________________________________
Test Example 4
Buffer Solution 7
A 20 mM citrate buffer containing, per ml, 0.02 mg of benzalkonium chloride and 100 mg of D-mannitol (pH 6.0).
Buffer Solution 8
A 20 mM maleate buffer containing, per ml, 0.02 mg of benzalkonium chloride and 100 mg of D-mannitol (pH 6.0).
Buffer Solution 9
A 20 mM succinate buffer containing, per ml, 0.02 mg of benzalkonium chloride and 100 mg of D-mannitol (pH 6.0).
To each of the above three buffer solutions was added an equal volume of a 6.8 mg/ml natural-type hGH aqueous solution and gently mixed to give aqueous compositions 7-9, respectively (final pH 6). Then each of the solutions was passed through a filter with a pore size of 0.22 μm and drawn into needled syringes by 1 ml each, removed of air babbles and then sealed to give samples. Each aqueous solution was put in storage for 6 months at 2-8° C. and samples were checked for change in monomer content, amount of deamidation products and general appearance after 0, 1, 3 and 6-month storage. The results are shown in Table 4. No formation of fine particles was observed in any of these aqueous preparation.
TABLE 4__________________________________________________________________________Results with aqueous preparations 7-9 stored for 6 months at 2-8°C. Monomer content (%) Amount of Deamidation product (%) Aqueous (SE-HPLC) (RP-HPLC)preparation Initial 1 month 3 months 6 months Initial 1 month 3 months 6 months__________________________________________________________________________7 99.0 99.0 99.0 99.1 2.4 2.4 3.7 4.2 8 99.2 99.3 99.1 99.0 2.3 2.3 3.6 4.0 9 99.1 99.0 98.9 98.8 2.4 2.5 3.7 4.3__________________________________________________________________________
Test Example 5
Test for Pain Upon Infusion
For evaluation of pain felt upon subcutaneous infusion which is attributable to the composition, injectable preparations were made by the addition of D-mannitol to each of a citrate, maleate or succinate buffer (final pH 6.0) in such a proper amount that would give a relative osmolarity of 1.1 compared with physiological saline. hGH, however, was not added because the purpose of the test was to examine the pain attributable to buffer types. After adequate explanation of the test purpose, the test was conducted on ten healthy male volunteers for the strength of pain upon infusion of the following three preparations. The tests of these preparations were conducted in blind fashion. The strength of pain was expressed by; (++) as being very painful, (+) painful, (±) could be said painful, (-) not painful.
Formula 1: 10 mM citrate buffer+D-mannitol (pH 6.0)
Formula 2: 10 mM maleate buffer+D-mannitol (pH 6.0)
Formula 3: 10 mM succinate buffer+D-mannitol (pH 6.0)
TABLE 5______________________________________Relation of pain upon infusion and the type of buffer (10 for each group) Formula (++) (+) (±) (-)______________________________________Formula 1 10 0 0 0 Formula 2 0 0 0 10 Formula 3 0 0 1 9______________________________________
The results are shown in Table 5. Figures in the table indicate the number of the subjects who gave the corresponding judgement. While all of the ten subjects judged the citrate based preparation as being "very painful", all the subjects judged the maleate based preparation as being "not painful". In addition, succinate based preparation was judged as being "not painful" by 9 subjects out of 10 and judged as "could be painful" by one subject. These results have revealed that there is felt little or no pain with maleate or succinate based preparations, in contrast with citrate based preparations, which cause strong pain upon infusion.
Test Example 6
Buffer Solution 10
A 20 mM citrate buffer containing, per ml, 0.02 mg of benzalkonium chloride, 50 mg of D-mannitol, 5 mg of sodium chloride and 2 mg of sodium benzoate (pH 6.0).
Buffer Solution 11
A 20 mM maleate buffer containing, per ml, 0.02 mg of benzalkonium chloride, 50 mg of D-mannitol, 5 mg of sodium chloride and 2 mg of sodium benzoate (pH 6.0).
Buffer Solution 12
A 20 mM succinate buffer containing, per ml, 0.02 mg of benzalkonium chloride, 50 mg of D-mannitol, 5 mg of sodium chloride and 2 mg of sodium benzoate (pH 6.0).
To each of the above three buffer solutions was added an equal volume of a 6.8 mg/ml natural-type hGH aqueous solution and gently mixed to give aqueous compositions 10-12, respectively (final pH 6). Then each of the solutions was passed through a filter with a pore size of 0.22 μm and drawn into needled syringes by 1 ml each, removed of air babbles and then sealed to give samples. Each aqueous solution was put in stored at 40° C. and 50° C., opened after 21 days, and then analyzed on RP-HPLC and SE-HPLC. The results are shown in Table 6.
TABLE 6__________________________________________________________________________Results of analyses of aqueous preparations 10-12 Monomer content (%) Amount of deamidation product (%) (SE-HPLC) (RP-HPLC)Aqueous 40° C. 50° C. 40° C. 50° C.preparation Initial After 21 days Initial After 21 days Initial After 21 days Initial After 21 days__________________________________________________________________________10 99.2 99.1 99.2 98.5 2.3 28.0 2.3 38.1 11 99.4 99.2 99.4 98.5 2.3 27.9 2.3 37.9 12 99.2 98.9 99.2 98.0 2.4 28.0 2.4 38.3__________________________________________________________________________
In any of the aqueous preparations, change in monomer content was very little after storage of 21 days at 40 and 50° C. Formation of deamidation products, on the other hand, was within limits of the expected long-term stability as mentioned in Test Example 3 above, i.e., enough to predict one-year stability.
Test Example 7
Buffer Solution 13
A 20 mM maleate buffer containing, per ml, 0.02 mg of benzalkonium chloride and 100 mg of D-mannitol (pH 6.0).
To the above buffer solution 13 was added an equal volume of a 20.4 mg/ml natural-type hGH aqueous solution and gently mixed to give aqueous preparation 13 (final pH 6.0). Then the solution was passed through a filter with a pore size of 0.22 μm and drawn into needled syringes by 1 ml each, removed of air babbles and then sealed to give samples. The aqueous preparation 13 was put in storage in incubators at 40° C. and 50° C., opened after 21 days, and then analyzed on RP-HPLC and SE-HPLC. The results are shown in Table 7.
TABLE 7__________________________________________________________________________Stability of aqueous preparation 13 Monomer content (%) Amount of deamidation product (%) (SE-HPLC) (RP-HPLC)Aqueous 40° C. 50° C. 40° C. 50° C.preparation Initial After 21 days Initial After 21 days Initial After 21 days Initial After 21 days__________________________________________________________________________13 99.2 98.8 99.2 97.1 2.2 28.5 2.2 39.6__________________________________________________________________________
The preparation showed little change in monomer content after 21-day storage at 40° C. and 50° C. Formation of deamidation products, on the other hand, was within limits of the expected long-term stability as mentioned in Test Example 1 above, i.e., enough to predict one-year stability
EXAMPLES
The present invention is described in further detail below with reference to typical examples. It should be noted, however, that the present invention is not limited by these examples. It is possible to increase or decrease the amount or concentration of each of the components set forth in the examples below, to substitute one ore more of their components with other components, or to include additional components.
Example 1
The components is admixed in accordance with the following formula to form a buffer solution, then added with the hGH solution described below, and sterilized by filtration to give an injectable preparation (final pH 6.0).
Buffer Solution
______________________________________Benzalkonium chloride 0.02 mg D-mannitol 100 mg 20 mM citrate buffer q.s. Total amount 1 ml (pH 6.0)______________________________________
hGH Solution
6.8 mg/ml natural-type hGH aqueous solution . . . 1 ml
Example 2
An injectable preparation is formed according to the formula below following the same procedure as Example 1 (final pH 6.0).
Buffer Solution
______________________________________Benzalkonium chloride 0.02 mg D-mannitol 100 mg 20 mM maleate buffer q.s. Total amount 1 ml (pH 6.0)______________________________________
hGH Solution
6.8 mg/ml natural-type hGH aqueous solution . . . 1 ml
Example 3
An injectable preparation is formed according to the formula below following the same procedure as Example 1 (final pH 6.0).
Buffer Solution
______________________________________Benzalkonium chloride 0.02 mg D-mannitol 100 mg 20 mM succinate buffer q.s. Total amount 1 ml (pH 6.0)______________________________________
hGH Solution
6.8 mg/ml natural-type hGH aqueous solution . . . 1 ml
Example 4
An injectable preparation is formed according to the formula below following the same procedure as Example 1 (final pH 6.0).
Buffer Solution
______________________________________Benzalkonium chloride 0.02 mg D-mannitol 50 mg Sodium chloride 5 mg Sodium benzoate 2 mg 20 mM citrate buffer q.s. Total amount 1 ml (pH 6.0)______________________________________
hGH Solution
6.8 mg/ml natural-type hGH aqueous solution . . . 1 ml
Example 5
An injectable preparation is formed according to the formula below following the same procedure as Example 1 (final pH 6.0).
Buffer Solution
______________________________________Benzalkonium chloride 0.02 mg D-mannitol 50 mg Sodium chloride 5 mg Sodium benzoate 2 mg 20 mM maleate buffer q.s. Total amount 1 ml (pH 6.0)______________________________________
hGH Solution
6.8 mg/ml natural-type hGH aqueous solution . . . 1 ml
Example 6
An injectable preparation is formed according to the formula below following the same procedure as Example 1 (final pH 6.0).
Buffer Solution
______________________________________Benzalkonium chloride 0.02 mg D-mannitol 50 mg Sodium chloride 5 mg Sodium benzoate 2 mg 20 mM succinate buffer q.s. Total amount 1 ml (pH 6.0)______________________________________
hGH Solution
6.8 mg/ml natural-type hGH aqueous solution . . . 1 ml
Example 7
An injectable preparation is formed according to the formula below following the same procedure as Example 1 (final pH 6.0).
Buffer Solution
______________________________________Benzalkonium chloride 0.002 mg D-mannitol 100 mg 20 mM maleate buffer q.s. Total amount 1 ml (pH 6.0)______________________________________
hGH Solution
6.8 mg/ml natural-type hGH aqueous solution . . . 1 ml
Example 8
An injectable preparation is formed according to the formula below following the same procedure as Example 1 (final pH 6.0).
Buffer Solution
______________________________________Benzalkonium chloride 0.01 mg D-mannitol 100 mg 20 mM maleate buffer q.s. Total amount 1 ml (pH 6.0)______________________________________
hGh Solution
6.8 mg/ml natural-type hGH aqueous solution . . . 1 ml
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Provided is an aqueous pharmaceutical composition comprising human growth hormone wherein said human growth hormone is dissolved in a benzalkonium chloride-containing, slightly to weakly acidic solution buffered, most preferably, with maleate. The composition is sufficiently stable to be supplied in liquid state and can be prepared as a less painful composition.
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This application is a continuation of U.S. patent application Ser. No. 10/256,598 filed on Sep. 27, 2002.
FIELD OF THE INVENTION
The present invention generally relates to systems and methods for online trading, and more particularly to systems and methods for conducting online trading in Over-The-Counter (OTC) instruments using electronic spreadsheets.
BACKGROUND OF THE INVENTION
Online trading of financial instruments such as equities (i.e., stocks) has become increasingly popular. In order to facilitate such trading, systems have been developed to provide data streams of real time exchange market data such as BLOOMBERG™ and REUTERS™. Systems have further been developed to accept this exchange data into electronic spreadsheets and to provide a link from the spreadsheet to exchange trading systems. One such system is known as AUTOMATE™ provided by GL™.
One other such trading system is disclosed in U.S. Pat. No. 6,134,535 to Belzberg. Belzberg discloses an automated trading system to launch a trading order to the order entry system of a stock exchange for stocks listed on the stock exchange. The system monitors real-time data feeds for a list of stocks and their prices that are recorded and displayed to a user in a spreadsheet format on a personal computer. When the composite price of the list of stocks conforms to certain predetermined parameters, the list is transformed into an order, which is immediately sent to an exchange order entry system.
One further trading system is shown in U.S. Pat. No. 5,893,079 to Cwenar. Cwenar discloses a system where an external data interface receives and processes real-time investment information from outside sources. The real-time data is processed and stored on a central server. Multiple users have access to the data through a spreadsheet interface. The system can be used to effect trades and monitor proposed trades for compliance with laws, rules, and preferences. A group of securities can be combined into “baskets”. Baskets can also be a single fund or group of funds combined for purposes of transactions.
SUMMARY OF THE INVENTION
The present invention is a system and method for receiving streamed, real time investment quotes, applying a spreadsheet based investment strategy to the real time quotes, generating electronic orders based on the results of the investment strategy analysis and transmitting the orders for real time execution.
In one embodiment of the present invention, the live real time quotes are for Over The Counter (OTC) investments, and in an alternative embodiment, the real time quotes are Exchange Traded (ET) instruments. These real time quotes are preferably provided in a secure session though the publicly accessible Internet. The real time quotes are received by remotely located user workstations (e.g., personal computers) through a standard web browser and a customized. Dynamic Data Exchange (DDE) interface into an Excel® spreadsheet. Although the present invention has been developed using Excel®, other comparable spreadsheet applications can be used, such as Lotus 123®. The spreadsheet program contains predefined logic representing an investment strategy that is applied to the received real time quotes. Of particular note is that the present invention is able to employ an investment strategy that encompasses several instruments (e.g., bonds, futures or options).
After the investment strategy logic has processed the real time quotes (in real time) and if the logic indicates that one or more instruments should be bought or sold, an order is automatically generated. This single order can contain instructions to buy or sell a plurality of instruments. In a preferred embodiment, the automatically generated order is confirmed by the operator of the workstation, or if desired, the order can be submitted automatically if it satisfies rules previously established by the user. The order is then electronically transmitted, in a secure session over the public Internet to a dealer that executes the order in real time.
An order identifier is automatically assigned when an order is submitted by a spreadsheet. This order identifier is recorded both in the spreadsheet and in the dealer's trade execution system. The dealer's execution system then provides real-time updates using this order identifier. Thenceforth, the execution status of the order is available in real time to the sender of the order as well as to other parties as authorized by the sender. This feature of the present invention is particularly attractive for developing and executing hedging strategies. For example, a second workstation can be monitoring for executed orders and can generate hedging orders based upon the execution of an original order.
The present invention can instantly evaluate trading strategies, positions, or Profit and Loss (P/L) based on live, executable prices. It automatically executes trades based on the previously spreadsheet calculated portfolio allocations, hedging strategies, funding requirements, etc. The positions contained in the spreadsheet are immediately updated as orders are executed. Multiple orders, either OTC (such as bond or OTC equity warrant orders) or ET (such as future or ET option orders), can be confirmed at once when submitted from the spreadsheet. The present invention further supports Futures and Options order modification and cancellation.
BRIEF DESCRIPTION OF THE DRAWINGS
For the purposes of illustrating the present invention, there is shown in the drawings a form which is presently preferred, it being understood however, that the invention is not limited to the precise form shown by the drawing in which:
FIG. 1 illustrates the system of the present invention;
FIG. 2 illustrates the steps for obtaining real time price quotes;
FIG. 3 shows a user interface screen illustrating a spreadsheet sheet populated by the present invention;
FIG. 4 depicts the steps for submitting an order;
FIG. 5 illustrates the steps for obtaining the status of an order; and
FIG. 6 illustrates the system for two traders to obtain order status.
DETAILED DESCRIPTION OF THE INVENTION
The system of the present invention is illustrated in FIG. 1 . As previously described, the system of the present invention is a real-time link between a spreadsheet 10 and a server 30 that both feeds the spreadsheet 10 with a real time data feed as well as accepts trade execution orders from the spreadsheet. In a preferred embodiment, the spreadsheet application is the EXCEL™ product from MICROSOFT™, but as appreciated by those skilled in the art, any robust electronic spreadsheet application can be used in the system of the present invention. In the preferred embodiment, the spreadsheet 10 is executing on a personal computer (not shown) preferably running Windows NT™ or another suitable operating system. The standard spreadsheet application 10 is supplemented with “add-in” programming to provide the user interfaces, simplify certain operations in the spreadsheet 10 and to support the functionality described herein (e.g., order submission).
The spreadsheet application 10 is coupled to a Dynamic Data Exchange (DDE) server 15 . DDE 15 is an interprocess communication (IPC) system built into most personal computer operating systems. In DDE terminology; the “server” 15 is a piece of software running on a personal computer that serves the DDE requests generated by the DDE client (the spreadsheet 10 , e.g., Excel). Alternatively, DDE server 15 is known as a DDE adapter 15 . DDE 15 enables two running applications to share the same data. In the present invention, DDE 15 provides links that make it possible for server 30 to supply real-time prices to spreadsheet 10 , and to allow spreadsheet 10 to submit orders to server 30 . Whenever the real time prices for a particular instrument specified in spreadsheet 10 changes, the price contained in (displayed by) the spreadsheet 10 changes accordingly. As an alternative to the DDE mechanism, Object Linking and Embedding (OLE) tools can be used. OLE enables one to create objects with one application and then link or embed them in a second application. Embedded objects retain their original format and links to the application that created them.
The DDE 15 is coupled to the workstation's Internet web browser 20 . In the preferred embodiment, the web browser is INTERNET EXPLORER™ from MICROSOFT™. Similar to the add-in for the spreadsheet 10 , the system of the present invention further has a signed Java applet which operates in conjunction with the web browser 20 to provide the functionality described herein. The web browser 20 provides connectivity, though the communication network 25 to server 30 . In the preferred embodiment, the communication network 25 is the Internet, but a private network or a dial up connection could be used. Such alternatives are not preferable to the Internet, though, given the ubiquity of the Internet. Web browser 20 communicates with the server 30 using a combination of streaming HTTPS data (for price and order updates) and synchronous HTTPS requests (for subscriptions and order submission).
Server 30 is the element of the present invention that maintains all of the real time financial instrument data and provides the interface for the execution of order submission. In the embodiment of the present invention involving non-exchange traded financial instruments (such as bonds or OTC equity warrants), the data maintained in server 30 is gathered from non-publicly available sources. Specifically, since the financial instruments are not exchange traded, the pricing of the instrument is made via quotes. In the preferred embodiment, this data is supplied from automated price generation systems controlled by traders for the OTC instruments. For ET instruments, the prices for the instruments are obtained from exchange feeds or market data vendor feeds (e.g. Bloomberg). Server 30 is coupled to various trading engines 35 which serve to actually execute the orders received from the customers through the spreadsheet 10 and the server 30 . The trading engines operate in the various markets in which the financial instruments are traded. In the preferred embodiment, OTC orders are executed automatically by execution engines 35 based on trader-supplied parameters, as known by those skilled in the art. ET orders are preferably routed to the trading desks of the operators of the system of the present invention or to external exchanges for execution. Based on the architecture shown, orders would be routed through server 30 and routed to the external exchanges. Alternately, the data feed can be routed directly from the user to the external vendor. The manner in which the data feed is routed is dependent upon the system architecture and the way the exchange licenses market data distribution.
FIG. 2 illustrates the interaction of the various components and the steps for obtaining real time price quotes. As previously described, the system of the present invention allows the user to use it familiar spreadsheet application 10 to define cell formulas that reference various attributes of a financial instrument. For example, the instrument can be described in a sheet of the spreadsheet application 10 in terms of its bid and ask prices and sizes, its trading status, and other real-time information, as well as reference data such as maturity date. As those skilled in the art are familiar with the types and formats of programming available in electronic spreadsheet applications 10 , no further discussion is necessary with respect to the routine establishment of a sheet in such a spreadsheet application 10 . In the preferred embodiment, the user of the system programs one or more sheets in the spreadsheet application 10 to reflect his/her trading strategy.
As described in FIG. 2 , the spreadsheet 10 will be automatically, continuously, and instantaneously updated to reflect any changes in the data related to any instrument defined in the spreadsheet 10 . This automatic and continuous updating is accomplished through the DDE server 15 . Values for specific attributes related to an instrument can be used in the present invention as any traditional spreadsheet value could be used. Such values can be entered into formulas, formatted using standard spreadsheet formatting rules (including dates and times), etc. The system of the present invention automatically loads and subscribes to the quotes (the data related to the financial instrument) when the spreadsheet 10 sheet is first loaded, assuming that you are set up to see the corresponding instrument.
Prices and statuses from server 30 can also be used to update conditional formats in spreadsheet 10 . This feature of the present invention allows the user to highlight changes that the user desires to be tracked closely. For example, a cell could cause to change color when a bid or ask price approaches or passes a target, assisting the user in monitoring and executing the user's predefined trading strategies with less effort.
Prior to the acquisition of real time data, the user loads his/her trading strategy sheet into spreadsheet 10 . This sheet identifies the financial instruments in which the user is interested. The instruments are identified by their industry standard codes such as ISIN (for International Securities Identification Number) or CUSIP (for Committee on Uniform Securities Identification Procedures), using a symbol such as ISIN_xxxxxxxxxxxxx, where xxxxxxxxxxxx is the 12 character ISIN code for the instrument
In step S 1 , the spreadsheet 10 contacts the DDE server 15 and subscribes to a DDE topic and several DDE items in order to obtain the data related to the instrument(s) contained in the user's sheet in the spreadsheet 10 . As known to those skilled in the art, a topic is the first part (usually a broader category) and item is a narrower piece of information. DDE 15 is relatively flexible about how one uses the constructs of topics and items. In a preferred embodiment of the present invention, topics are used to identify instruments and orders, and items are used to identify fields within these. As appreciated, different market data vendors and system designers can construct their data structures differently. Using Excel, the full DDE syntax in Excel is “=Service|Topic!Item.” In the preferred embodiment this will result in a syntax of “=Service|InstrumentID!FieldName”. By subscribing, the spreadsheet 10 is requesting that the DDE 15 set up links with server 30 to retrieve all of the relevant data for the instruments specified in the subscription. In step S 2 , the DDE 15 passes the subscription onto the Java applet in the web browser 20 . An example of a protocol for the transmission of the subscription from the DDE 15 to the Java applet 20 for a single instrument with an ISIN code of ISIN_DE0001135135 is as follows:
SUBSCRIBE|ACTIVATE|ISIN_DE0001135135|*
In step S 3 , the Java applet in the web browser 20 transmits a query to the server 30 with respect to the instrument(s) specified in the subscription from the DDE 15 . Note that the communication network 25 ( FIG. 1 ) has been omitted in the present Figure, merely for reasons of simplicity. Again, in the preferred embodiment, the communication network 25 is the Internet. In response to the query form the web browser 20 , in step S 5 , server 30 returns reference data related to the specified instrument(s) to the Java applet in the web browser 20 . The reference data is obtained by the server 30 from the real time markets through trading engines 35 (only one shown). The reference data is obtained in order to determine a correlation between the descriptions of instruments as used by spreadsheet 10 and by the real time markets. For example, the symbol used by an Excel spreadsheet 10 is not the same as that used by the real-time market data infrastructure. One advantage of providing this abstraction of the real time market symbols this is that the server 30 can obtain prices for the same instrument from different sources in response to a single query by a user using a single common description of the instrument.
Once the correlation for the symbols for the instrument is established, the trading engines 35 continuously updates the instrument data to the server 30 (step S 4 ). In the ET embodiment, the real time data representing the financial instruments can be received from an external vendor for this data. In a preferred embodiment, the data from trading engines or the external ET vendor is cached by server 30 (or by a separate caching system coupled to server 30 .
In step S 6 , the Java applet in the web browser 20 transmits a subscription to server 30 with respect to the real-time data related to the specified instrument(s). In response to this subscription, the server 30 returns real time updates for the instrument(s) to the web browser 20 (step S 7 ). Most importantly, the real time update data for the instrument includes real time updates with respect to the price of the instrument(s). If the instrument is a stock, though, important update data could include the quantity of the stock traded for the day. Trade volume is data related the stock that changes constantly and must be updated and monitored in real time in certain trading strategies.
In step S 8 web browser 20 passes the updated instrument data onto DDE server 20 . Below is an example of the format of such an update.
M|u|ISIN_DE0001135135|DESCRIPTION=BUND 5.375
Jan10|MARKET_PHASE=System
Unavailable|CCY=EUR|BID_QTY=10,000,000|BID=103.41|
ASK=103.51|ASK_QTY=10,000,000|BID_YLD=4.817|
ASK_YLD=4.802|YLD_CHG_DAY=−5.933|ASSET_SWP=−
15|ASSET_SWP_CHG=1|TIME=12:08:32|CODE=ISIN
DE0001135135|MATURITY_DT=2010/01/04|SETTLE_DT=
2002/07/05|COUNTRY=DE|ISSUE_DT=1999/10/12|
INSTR_GROUP=EGB
German|COUPON=5.375|PRICE_CHG_DAY=0.373|PVBP=
6.316|SUPPORT_CODE=|BID_PRICE_FLAG=Firm|
ASK_PRICE_FLAG=Firm|BID_STATUS=Active|ASK_
STATUS=Active|
BID_TICK=0|ASK_TICK=0|SYS_SOURCE_LOC=LON
Steps S 4 , S 7 and S 8 continuously feed new pricing data for the instruments in the subscription from the trading engines 35 to the server 35 to the web browser 20 to the DDE server 15 . This automatic feed continues until the subscription is cancelled. No further requests from the DDE 15 or web browser 20 are required. In step S 9 , the price update is passed onto the spreadsheet application 10 from the DDE 15 . The spreadsheet 10 uses this data to update the sheet that initiated the entire process. Steps S 10 and S 11 illustrate the continuous process by which the spreadsheet 10 is updated with new real time pricing data from the DDE server 15 . DDE 15 notifies spreadsheet 10 when update data is available. Spreadsheet 10 pulls the update data from DDE 15 when it is ready to process the update data. Spreadsheet 10 then waits for another notification from DDE 15 that updated data is available. Once it has established a subscription with respect to one or more instruments, it is not necessary for spreadsheet 10 to actively poll DDE 15 for data updates.
FIG. 3 illustrates a sample sheet 150 in spreadsheet application 10 that has been populated by the system of by the present invention in accordance with the process described in connection with FIG. 2 . Although the screen illustrated in FIG. 3 depicts eight different columns, as appreciated by those skilled in the art, the user can choose to include any combination of the fields that constitute the reference data that defines the instruments. Typically, there are 50-150 fields that describe any particular financial instrument. Column 155 contains the industry standard codes for the financial instruments that the user has included as part of sheet 150 . Again, these financial instruments are instruments that the user has chosen to keep track of, and include as part of the user's trading strategy. Column 160 contains the description of the instruments of column 155 . Columns 165 , 170 , 175 and 180 respectively contain the Bid and Ask quantities as well as the Bid and Ask prices. Column 185 indicates whether or not the market for the particular instrument is presently open. Finally, column 190 contains a proposed settlement date for a trade involving any particular financial instrument.
As appreciated by those skilled in the art, sheet 150 can contain formulas and other programming that analyzes the data for the financial instruments. In a simple example, the Bid 165 and Ask 170 columns can be conditionally formatted to indicate tic up/down in these prices by shading the changing values in different colors (e.g., red and green). As further described below, other extensive programming can be applied to the cells of the sheet 150 to implement the user's trading strategy. For example, in a simple trading strategy, the user can program spreadsheet 10 to implement a trading strategy that recognizes when the price of an instrument reaches a predetermined threshold, that the instrument should be sold. As appreciated by those skilled in the art, this is the simplest of trading strategies. Modern electronic spreadsheets 10 are capable of implementing incredibly complex trading strategies analyzing the data for hundreds or even thousands of financial instruments in real time. Tabs 195 and 200 indicate other sheets for implementing the user's other trading strategies.
FIG. 4 illustrated the submission flow for orders in accordance with the present invention. Orders are the instructions from the user to either buy or sell one or more financial instruments. There are several methods according to the present invention by which orders can be prepared in spreadsheet 10 prior to their transmission and execution. The method of the present invention allows the user to automate routine order entry tasks, such as those involved with re-balancing a portfolio or hedging a book.
There are two basic ways in which the system of the present invention generates orders, one manual and one automatic. In each of the methods, the order would contain the basic information required to execute the order such as a description of the financial instrument (e.g., the ISIN number), the quantity, the price, the settlement date, etc. IN the manual mode, the user has an active page on spreadsheet 10 that contains all of the potential orders. One of the columns associated with each order is an “Enabled” column that indicates whether the user wants a particular order executed or not. The spreadsheet has a button 200 (See FIG. 3 ) that the user activates to submit the orders. Only the orders with a positive indication in the “Enabled” column will processed for submission to the trading engines 35 (see FIG. 1 ). In the preferred embodiment, the system requires active confirmation for all orders that are submitted manually.
In the automatic mode, spreadsheet 10 is programmed to automatically generate and submit orders if certain conditions occur. In a very simple example, the user can specify that an order be executed if the price of a particular financial instrument attains a certain value. As appreciated by those skilled in the art, spreadsheet 10 can be programmed to evaluate hundreds of variables in executing complex trading strategies in order to determine if an order should be automatically submitted. As with the manual mode, the automatically submitted orders contains all of the information required to execute the order (e.g., price, quantity . . . )
In a preferred embodiment, the spreadsheet generates an order ID when the order is submitted. This order ID can be written into a cell of the spreadsheet. The order ID is used to obtain order status updates for specific orders. The order ID allows precise automated monitoring of order status, which in turn allows trading strategies to be developed that depend upon the execution status of a previous order. For example, a limit order can be submitted to an exchange, which is not executed immediately. When the limit order is executed, another order can be automatically submitted, possibly on another market, e.g., an OTC bond order. The order ID allows individual orders to be tracked and allowing various trading strategies to be implemented including automated trading.
In step S 20 , spreadsheet 10 has generated an order that contains instructions with respect to one or more financial instruments. As part of the actual order, spreadsheet 10 includes a unique order identifier (e.g., BRIANLYNNTRADER2002070212190000). This unique order identifier is assigned by the spreadsheet 10 add-in, which updates the sheet from which the order originated to create a subscription to keep track of the status of the execution of the order (see below).
DDE server 15 receives the order from spreadsheet 10 and transmits the order to the web browser in step S 21 . The order submitted by DDE 15 retains the unique order identifier assigned by spreadsheet 10 . The following is an example of the protocol of the order transmitted by DDE 15 :
JPEX_ORDER|BRIANLYNNTRADER2002070212190000|
ISIN_DE0001141281|ORDER_QTY=10000|
BUY_SELL=FALSE|ORDER_TYPE=IMMEDIATE|
PRICE_CHECK_TYPE=At Market|
BATCH=BRIANLYNNTRADER2002070212183600RANGE
In step S 22 , web browser 20 transmits the order (still including the unique order identifier) to the server 30 . One again, the communication network 25 ( FIG. 1 ) has been omitted from the present Figure merely for purposes of clarity. Upon receipt of the order from web browser 20 , server 30 saves original order that contains the unique order identifier. As explained below, this is a significant feature of the present invention that allows tracking of the status of the order by one or more parties. In processing the original order, server 30 takes the information contained in the order and generates executable orders in the format required by trading engines 35 . This is the reason that server 30 must save the original order containing the unique order identifier. Otherwise, the original order identifier generated by spreadsheet 10 would be lost to server 30 and thus unusable for updating the order status in linked spreadsheets 10 .
In step S 23 , sever 30 sends the formatted order (or multiple orders if several financial instruments are involved) to trading engines 35 . The orders sent to trading engines 35 by server 30 contain new unique server order identifier that is generated by server 30 and inserted into the order(s). Server 30 maintains a database in which it correlates the unique order identifier generated by spreadsheet 10 with the unique server order identifier that it has generated. This correlation is used by server 30 to enable tracking by the system of the status of the orders submitted by the spreadsheet 10 as illustrated in FIG. 5 .
FIG. 5 illustrates the method of the present invention for tracking the status of an order. The present invention provides the capability to monitor the status of orders in real time. The DDE references to various order fields, including order ID, status, executed quantity and price, update time, etc can be entered on a sheet in spreadsheet 10 to view the real time status of the orders. These values are also provided in standard spreadsheet 10 data types, and can be used to drive formulas. For example, a status sheet could use the executed quantity in a formula to drive a position-keeping sheet. In a preferred embodiment of the present invention, when an order is submitted, an entry is automatically created for the submitted order on a status sheet known as a blotter. Once the order is submitted, the system creates the status entry on the blotter sheet and the user is able to switch over to that blotter to view the status of all of its orders.
In step S 30 of FIG. 5 , spreadsheet 10 submits a subscription 10 DDE 15 with respect to the order for which status is desired. In the subscription, the topic is set equal to the unique spreadsheet identifier as previously described with respect to FIG. 4 . An example of the format for such a subscription is: BRIANLYNNTRADER2002070212. DDE 15 takes this subscription from spreadsheet 10 and in step S 31 transmits the subscription to the add-in in the web browser. The subscription from DDE 15 to web browser 20 includes the unique spreadsheet identifier associated with the order. A sample protocol for the subscription is:
SUBSCRIBE|ACTIVATE|JPEX_ORDER.DDE.BRIANLYNNTRADER2002070212190000|*
In the preferred embodiment, server 30 is programmed to automatically provide status updates for all active orders after the order has been submitted to server 30 . Accordingly, there is no need for web browser 15 to send any further messages to server 30 to set up the subscription for the status of active orders. In step S 32 , the trading engines 35 , pursuant to the automatic updating of the preferred embodiment, provides server 30 with an update of all of the fields associated with the order. The order status from the trading engines only includes the server 30 assigned identifier, as the trading engines 35 are unaware of the spreadsheet identifier. Upon receipt of the update from the trading engines 35 , the server 30 consults its database and retrieves the spreadsheet unique order identifier and appends that identifier to the order status.
In step S 33 , server 30 transmits the order status to web browser 20 (in a preferred embodiment through the Internet, not shown). The order status from server 30 preferably contains both the server identifier for the order as well as the spreadsheet identifier. One reason for the inclusion of the server identifier is that in one embodiment of the present invention it is possible for spreadsheet 10 to keep track of orders by the server identifier in addition to the internally assigned spreadsheet identifier. This allows the spreadsheet to track orders not originally submitted from a spreadsheet, e.g. orders submitted directly into web browser 20 . Due to the automatic updating of order status in the preferred embodiment, steps S 32 and S 33 continually feed the web browser 10 with the updates of the statuses of the active orders.
In step S 34 , the add-in to the web browser 20 transmits the received order status to DDE server 15 . The order status preferably contains the unique spreadsheet identifier and optionally contains the server identifier or other identifier that allows the spreadsheet to uniquely identify the order. A sample protocol for the order status is as follows:
M|u|JPEX_ORDER.DDE.TRADER12002072417301701|ORDER_
ID=10,997|Trade ID=7,409|RFQ_ID=|ORDER_STATUS=Executed|
INSTR_NAME=OBL 128 3.75
Aug03|BUY_SELL=Sell|CCY=EUR|EXEC_QTY=10,000|MARKUP=
---|Exec Spd=---|SETTLE_AMT=0|SETTLE_DT=2002/07/29|EXCH_
CODE=|REJECTION_MSG=|ORDER_QTY=10,000|PRICE_
CHECK_TYPE=At Market|VALIDITY=Immediate|PRICE=100.306|
Order Spd=---|QUOTED_PRICE=---|Quoted Spd=---|LOCAL_CODE=
|CREATION_DT=2002/07/24|CREATION_TIME=17:30:17|UPDATE_
DT=2002/07/24|UPDATE_TIME=17:30:20|INSTR_ALT_ID=
DE0001141281|USER_ID=trader1|NOTES=|REM_QTY=0|FILLS=
1|COUNTRY=DE|CLIENT_FIRM=BL Company|EE_ORDER_ID=
133773|EE Trade ID=118518|EE_QUOTE_ID=|DESCRIPTION=
OBL 128 3.75 Aug03|CODE=DE0001141281|INSTR_GROUP=EGB
German|LIMIT_POS=|EXEC_PRICE=100.306|STOP_PRICE=---
|BE_CREATION_DT=2002/07/24|BE_CREATION_TIME=17:30:17|
BE_UPDATE_TIME=17:30:20|BE_ACCOUNT=GSAMXLON|
ACCOUNT_NAME=account 1|CTI=|ORIGIN= |FEE= |ALLOC_
PCT=|ACCOUNT_TYPE=|EXCH_ORDER_ID=133773|CREATOR_
ID=trader1|LAST_MOD_ID=trader1|ORIG_OWNER_ID=trader1|
BE_USER_ID=|AltOrderID=TRADER12002072417301701|
AltBatchID=TRADER12002072417301700RANGE|
AltOrderSource=Excel Manual|INSTR_ID=ISIN_DE0001141281|
DDE_ORDER_ID=TRADER12002072417301701
In step S 35 , DDE server 15 notifies spreadsheet 10 that an update to the status of the order is available. In step S 36 , spreadsheet 10 requests the update. And in step S 37 , DDE server 15 provides the update to spreadsheet 10 . Spreadsheet 10 then uses the updated data to refresh the data corresponding to the order contained on one or more sheet within spreadsheet 10 .
FIG. 6 illustrates the system for two traders to obtain order status. In particular, this embodiment is useful for executing a hedging strategy. FIG. 6 illustrates the process by which trader 102 can monitor trader 101 's complex trading strategies using spread sheet 10 . In this embodiment, each trader 100 and 102 has identical systems, namely a spreadsheet application 10 with an appropriate add-in as described above, a DDE server 15 and a web browser 10 (with appropriate applet). In a hedging scenario, trader 100 is performing trades against which trader 102 is hedging.
In this scenario, trader 100 creates a series of automatically maintained limit orders in it spreadsheet 10 and saves a copy of his spreadsheet-based orders. Trader 102 then loads a view of these orders and automatically sets up hedging orders in a second session in his spreadsheet application 10 . The hedging orders of trader 102 are based on real-time price and order status feeds relative to trader 100 's orders. As previously described, all trading strategies according to the present invention are entirely user-definable using the rules of the spreadsheet application 10 .
In step S 40 , trader 100 submits his orders to server 30 as previously described with respect to FIG. 4 . In step S 41 trader 100 saves his spreadsheet that contains the unique spreadsheet order identifiers to a shared file server 105 . In step S 42 , trader 102 retrieves the saved spreadsheet that contains trader 100 's live orders. In step S 43 , each of traders 100 and 102 begins receiving the order status updates for the live orders as previously described with respect to FIG. 5 . Again, trader 102 is able to retrieve the status of the order of trader 100 because trader 2 is using the unique spreadsheet order identifier assigned to trader 100 's orders. Server 30 is able to provide trader 102 with the status of trader 100 's orders as trader 102 is using the unique order identifiers assigned to trader 100 's orders. In executing a hedging strategy, the spreadsheet 10 of trader 102 will monitor the status of the orders of trader 100 , and when specific conditions occur (e.g., trader 100 's orders are executed), trader 102 's spreadsheet 10 will automatically generate its own hedging orders.
Although the present invention has been described in relation to particular embodiments thereof, many other variations and other uses will be apparent to those skilled in the art. It is preferred, therefore, that the present invention be limited not by the specific disclosure herein, but only by the gist and scope of the disclosure.
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A system and method for receiving streamed, real time quotes with respect to financial instruments. The system applies a spreadsheet based investment strategy to the real time quotes, generating electronic orders based on the results of the investment strategy analysis and transmitting the orders for real time execution. The system generates a unique order identifier that allows users to actively track the status of orders in real time. This unique order identifiers can be shared with other users so that other trading strategies can be developed to execute upon the successful execution of the order (e.g., hedging).
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TECHNICAL FIELD
[0001] The present disclosure relates to digital printing apparatus, such as printers and copiers.
BACKGROUND
[0002] Copiers, printers, and other multifunction machines, such as including scanning and facsimile capabilities, are familiar in offices. (As used herein, all such machines will be generically called “printers.”) A digital printer is typically a machine having both hardware and software aspects. Various of these aspects mandate that the machine undergo a distinct time period between the machine being turned on or otherwise requested to operate and the machine being ready to output prints. Among possible software aspects may be a need for an internal processor to “boot up” or otherwise become active; or an interpreter or equivalent program to process incoming image data to make the data directly useable by the hardware. Among possible hardware aspects are activating any number of motors or drives, such as to draw a print sheet into a position to receive an image. In the case of xerographic or electrostatographic printers, there is typically an appreciable “warm-up” time in which a fuser is brought to a necessary temperature, and/or a charging device is brought to a necessary potential. In the case of an ink-jet printer, there is typically a warm-up time in which, for instance, lines or channels for conveying liquid ink are primed, or a solid ink stick is partially melted to yield a useable quantity of liquid ink. In the case of an input scanner, which is usually part of a digital copier, there is typically a necessary warm-up time for an illumination lamp to reach a necessary luminescence.
[0003] It is generally known, in the office equipment industry, to provide systems by which a printer can have active and inactive modes. Clearly, a printer will be consuming more energy during an active state than an inactive state. In many cases, the warm-up time (whether literal or figurative) of a printer is itself a major consumer of time and energy, and therefore there is a desire to lessen the number of times a printer is requested to “wake up” in the course of a day.
[0004] U.S. Pat. Nos. 6,252,681; 6,805,502; and 6,819,445 propose methods of operating digital printers to enhance long-term performance.
SUMMARY
[0005] According to one aspect, there is provided a method of operating a digital printer, the digital printer accepting data relating to a document to be printed, and outputting a print related to the data, the digital printer being operable in an inactive mode and an active mode. In response to receiving a first print request, the digital printer delays beginning switching from the inactive mode to the active mode, for a delay period of predetermined duration. In response to receiving a second print request during the delay period, the digital printer begins switching from the inactive mode to the active mode substantially immediately.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a simplified elevational view of a copier/printer.
[0007] FIG. 2 is a flowchart illustrating an aspect of a method of controlling a printer.
DETAILED DESCRIPTION
[0008] FIG. 1 is a simplified elevational view of a copier/printer, referred to generally as printer 10 . (As used herein, the word “printer” shall apply to any machine that outputs prints based on image data from any source, including copiers, facsimile machines, and multi-function devices.) The printer 10 includes a control system 12 , which accepts image data from an external source, such as a network. Control system 12 can include means, such as including a memory, for retaining image data, such as when multiple jobs or other print requests are entered into the control system 12 . Control system 12 typically includes one or more processors, along with ancillary chips such as for memory. Such processors may require an appreciable amount of time to “boot up” or otherwise become able to process data.
[0009] Control system 12 is operative of what can generally be called a “print engine” 14 , that can be of any type familiar in the art of office equipment. A print engine can be defined as any hardware that can be controlled to create a desired image on a sheet. Most types of print engine include at least one motor, such as for moving a sheet relative to the print engine; such a motor is indicated in a general form as 16 . This motor 16 can be generally considered to be able to position a sheet drawn from a stack such as 24 to receive an image from the print engine 14 . If the print engine 14 is xerographic, the engine will further include at least one device or member, such as a corona device, development unit, or transfer device, which must be brought to a predetermined potential in order to operate; such a member is generally indicated as charge device 18 . If the print engine 14 is of another type, such as ink-jet of some type, there is typically some heating device, here generally indicated as 20 , which must be brought to a predetermined temperature to operate. Even in a typical xerographic printer, a heating device in the form of a fuser is typically employed.
[0010] Also associated with control system 12 is a scanner 30 , for recording image data from a hard-copy original such as placed on a platen 34 or run through a document handler (not shown). Many scanners include an illumination lamp 36 , which must reach a certain brightness in order to operate. The image data recorded at scanner 30 is retained within control system 12 , for substantially instant printing through print engine 14 , when the printer 10 is operating as a copier. There is typically also provided at the printer 10 a user interface 40 , such as in the form of a button-pad or touchscreen, by which a human user near the printer can enter commands (e.g., how many copies to be printed, reduction/enlargement, stapling, etc.).
[0011] As mentioned above, various hardware elements of a printer 10 , such as most typically motor 16 , charge device 18 , heating device 20 , and/or illumination device 36 , require an appreciable amount of time to change from a “inactive” mode to an active mode, in which the elements are ready for outputting prints. In practice, there are two general types of active/inactive modes. It is known in the art of office equipment to control a printer to operate in what is generally called a “sleep” or “energy-saving” mode, in which, for example, after a period of about 30 minutes without receiving a new job to be printed, the fuser, and perhaps the corotrons or other charged members, are shut down. When a print job is subsequently sent to the printer, the fuser and charge devices must literally “warm up”. To warm up from sleep mode typically takes on the order of one to two minutes.
[0012] Another type of active/inactive mode relates specifically to the starting of motors within the printer, and can be called “cycle in/cycle out” time. In a typical practical xerographic printer, the main motor such as 16 , developer module such as including a charge device 18 , etc. start working about 0.5 seconds before starting to feed the paper from stack 24 , which then takes about three seconds to get to the location within print engine 14 where an image is transferred or conveyed to the sheet. The placing of the image on the sheet takes about one second for a 60 page-per-minute machine and then takes about three seconds to feed to the output tray. The efficiency is 1 second of printing out of 7.5 total seconds of operation from a “standing start”; this means that 1/7.5=13.3% of the time to run the job is actually spent placing an image on the sheet and almost 87% is wasted time. If two jobs are stacked together and run with one “standing start” of the motors, the imaging time is two seconds out of an overall run time of 8.5 seconds for an efficiency of 23.5%.
[0013] It will be noted that the cycle-in time is typically on the order of three to ten seconds, while the warm-up time is on the order of one to two minutes. In a practical application, the two types of inactive/active modes are qualitatively different, as warm-up time from sleep or energy-saving mode requires heating and/or charging (which can involve heating) of a member such as 18 , while cycle-in time is mainly directed to starting at least one motor such as 16 and positioning a sheet to receive an image from a print engine 14 . Also, sleep modes are typically designed with an emphasis on energy efficiency, while cycle-in/cycle-out times are considered mainly from the standpoint of time efficiency.
[0014] FIG. 2 is a flowchart describing an operation of control system 12 . According to an embodiment, control system 12 operates to identify opportunities to combine jobs or print requests in time, to reduce the number of changes between active and inactive modes, and thereby improve the efficiency (in a time and/or energy sense) of the printer 10 .
[0015] At some time while it is in an inactive mode, the control system 12 receives a first print job (step 200 ). First it must be determined that the printer is in an operational mode in which the method is desirable to be used (step 202 ); this step will be described in detail below. If the method is desirable to be used, upon receiving the first print job, a clock is in effect started (step 204 ). The printer 10 , as controlled by control system 12 , will not begin changing from inactive to active mode (of either the warm-up or cycle-in type) until the clock reaches a time limit of predetermined duration, unless another print job is received during the duration (steps 206 and 208 ). If a second print job is received during the duration, the control system substantially instantly enters an active mode, and the first print job and second print jobs are printed in succession (step 210 ). If no second job is received before the clock ends, the first job is printed by itself (step 212 ).
[0016] The underlying operational theory of effectively delaying the beginning of changing from an inactive to an active mode until two jobs are accumulated is to reduce the number of times the mode must change over a period of time. Ideally, a number of jobs or other print requests should be clumped together closely in time following a single cycle-in or warm-up period. The purpose of the delay is to have the control system await an opportunity to concatenate a plurality of jobs over time. The duration of the delay should be selected so that the first job will be printed (if no second job arrives) before a significant customer dissatisfaction occurs. In one practical context involving cycle-in times, an effective duration is about fifteen seconds, or more broadly in a range between ten and thirty seconds. A duration can be programmed in non-volatile memory and be changed as per user preference, or in response to some control algorithm.
[0017] A copy job requested through user interface 40 may count as a second print job in the method of FIG. 2 , although any change from inactive to active mode may have to take into account an amount of time for an illumination lamp such as 36 to reach a predetermined brightness before exposing an image placed on platen 34 .
[0018] Returning to step 202 , there are many factors that may be used to determine whether to use the delay described in the method, and also to select the predetermined duration of the delay. Among the possible factors are: the distribution and frequency of jobs received in a preceding period, such as an hour; the time of day; the average length (and/or other derivative statistics) of jobs received over some past time; the location or other origin of the first or second print job (i.e., the customer dissatisfaction with a delay will be less if the computer sending the job is physically far away from the printer 10 ); or some other identifier of the first or second print job (such as a job effectively indicated as low-priority). Also, if the first job is a copy job, there is likely to be a more noticeable customer dissatisfaction if there is a noticeable delay in the time of the output sheet. Of course, if the printer 10 is already in active mode when the first print request is received, the method of FIG. 2 need not be used.
[0019] Although the method illustrated in FIG. 2 is generalized for a change from an inactive mode of either type, warm-up or cycle-in, there may exist within a control system 12 a plurality of similar methods, with different criteria and differently-determined delay periods, one for each type of change.
[0020] Although the method illustrated in FIG. 2 specifies that the control system 12 will begin changing from an inactive to active mode if two print jobs are requested within a time period of predetermined duration, it is conceivable that a higher standard, such as accumulating three or more print jobs before ending the delay period, could be provided.
[0021] As used herein, the term “print request” shall mean any request of the printer 10 to output prints from any source, including print jobs, copy jobs, facsimile jobs, etc.
[0022] The claims, as originally presented and as they may be amended, encompass variations, alternatives, modifications, improvements, equivalents, and substantial equivalents of the embodiments and teachings disclosed herein, including those that are presently unforeseen or unappreciated, and that, for example, may arise from applicants/patentees and others.
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A digital printer is operable in an inactive mode, such as a sleep mode or a cycle-in mode, and an active mode. In response to receiving a first print request, the digital printer delays beginning switching from the inactive mode to the active mode, for a delay period of predetermined duration. In response to receiving a second print request during the delay period, the digital printer begins switching from the inactive mode to the active mode substantially immediately. The delay increases opportunities for processing multiple print requests within one switching to the active mode.
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INCORPORATION BY REFERENCE
[0001] The disclosure of Japanese Patent Application No. 2007-222866 filed on Aug. 29, 2007, including the specification, drawings and abstract, is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to a structure of an oil pan provided in an internal combustion engine, such as an engine for an automobile, and an internal combustion engine including the oil pan. In particular, the invention relates to an improvement in the shape of the oil pan having a small-depth portion and a large-depth portion.
[0004] 2. Description of the Related Art
[0005] In an engine for an automobile, or the like, engine oil (which will be simply called “oil”) is stored in an oil pan that is provided in a lower part of the cylinder block. When an oil pump is driven using the torque of the crankshaft, the oil in the oil pan is drawn up via a strainer, and is fed under pressure to various parts of the engine, for lubrication or cooling of these parts. The oil that has been used for lubrication or cooling of the engine parts drops into the interior of the oil pan, to be collected for reuse (as disclosed in, for example, Japanese Patent Application Publication No. 2003-49624 (JP-A-2003-49624)). The oil pump may be of a motor-driven or electrically-operated type.
[0006] When the automobile runs on an inclined road or slope, or when a lateral acceleration (centrifugal force) is applied to the automobile during cornering, the oil stored in the oil pan may shift to one side and accumulate on this side in the oil pan. In this case, the oil pump may be brought into a condition (which will be called “air sucking condition”) in which an oil inlet of the above-mentioned strainer is exposed to the air. In the air sucking condition, lubricating oil fails to be introduced into the oil pump (i.e., the oil pump is brought into a “dry” state), and the operation to circulate the oil is not smoothly performed. Furthermore, various sliding parts in a pumping mechanism of the oil pump suffer from poor lubrication, resulting in wear of components that constitute the pump, and its sealed regions may not provide desired air- or oil-tightness, resulting in reduction in the reliability of the pump.
[0007] Technologies for avoiding the “air sucking condition” as described above have been proposed in Japanese Patent Application Publication No. 8-189324 (JP-A-8-189324) and Japanese Patent Application Publication No. 6-101568 (JP-A-6-101568). In the structures as disclosed in these publications, the bottom of the oil pan is shaped so as to provide a small-depth portion and a large-depth portion, and an oil strainer is placed in the large-depth portion that permits the oil to be stored to a large depth, so as to avoid the “air sucking condition” as described above. In an engine having a relatively large displacement, which is installed on, for example, a SUV (Sport Utility Vehicle), a large-sized oil pan is employed in which a large amount of oil is to be stored, and the depth of the large-depth portion is also set to a relatively large value.
[0008] In the structure as disclosed in JP-A-8-189324, vertical ribs extending in the vertical direction and a top-face rib that spreads in the horizontal direction at the upper ends of the vertical ribs are provided on an outer circumferential surface of a suction member located in the large-depth portion, so that air is inhibited from flowing into an oil inlet of the suction member.
[0009] In the structure as disclosed in JP-A-6-101568, a structural component, which is to be immersed under an oil surface when the oil surface is inclined during, for example, cornering of the automobile, is bolted to the cylinder block via a support or supports. With this arrangement, the “air sucking condition” may be avoided by raising the oil level by an amount corresponding to the volume of the structural component when the oil surface is inclined.
[0010] However, the above-described structures of JP-A-8-189324 and JP-A-6-101568 have problems as described below.
[0011] In the structure of JP-A-8-189324, since the vertical ribs and top-face rib need to be provided on the outer circumferential surface of the suction member, the structure of the suction member and the production thereof tend to be complicated. Also, the outer edges or peripheries of the vertical ribs and top-face rib need to be located close to the inner wall of the large-depth portion of the oil pan, so that the vertical ribs and top-face rib effectively restrict or inhibit flowing of air into the suction member. Thus, it takes substantial time and effort to design the shapes of the outer edges of the vertical ribs and top-face rib and the shape of the inner wall of the large-depth portion, with a low degree of flexibility or freedom in design thereof, resulting in a significant restriction imposed on the shape of the oil pan. Thus, the oil pan having this structure is not suitable for practical use.
[0012] In the structure of JP-A-6-101568, the structural component needs to be bolted to the cylinder block via the support(s), resulting in an increase in the number of components and complication of the assembling procedure. Thus, the oil pan having this structure is not suitable for practical use, as in the case of JP-A-8-189324.
[0013] The above-described technologies as disclosed in JP-A-8-189324 and JP-A-6-10156 aim to avoid the “air sucking condition” under a situation where a certain amount of oil is stored in the large-depth portion of the oil pan. Namely, the technologies of these publications are based on a technical concept that it is possible to avoid the “air sucking condition” by keeping the level of the oil stored in the large-depth portion at a sufficiently high level even when the oil pan is in an inclined state. Thus, if the amount of oil collected into the large-depth portion is kept extremely reduced for a relatively long period of time, as compared with the amount of oil drawn up by the oil pump through the strainer, namely, if the amount of oil collected into the large-depth portion after being circulated through various engine parts is kept extremely reduced for a relatively long period of time, the structures of the above publications may not be expected to provide the effect of avoiding the air sucking condition. In the following description, this situation will be explained more specifically.
[0014] FIG. 8 is a view showing an oil pan o including a small-depth portion b and a large-depth portion c, in which the small-depth portion b is located on the front side of the vehicle and the large-depth portion c is located on the rear side of the vehicle. Referring to FIG. 8 , the oil storage condition and oil collecting condition of the oil pan o when the vehicle runs on a downhill will be explained.
[0015] While the vehicle keeps running on a downhill, the oil in the large-depth portion c is drawn up via a strainer d in accordance with driving of the oil pump. Then, the oil is collected into the oil pan o for reuse after being circulated along the inner walls of the cylinder block and the outer surface of the crankshaft. In this case, the oil flows down, along the inner walls of the cylinder block and the outer surface of the crankshaft, toward the front side of the vehicle body due to its own weight. Therefore, a large portion of the oil collected in the oil pan o reaches the small-depth portion b. The length of arrows shown in FIG. 8 represents the amount of the oil that drops or flows down into each region of the oil pan o. Namely, a large amount of oil is collected in a region of the oil pan where the arrow has a large length, and a small amount of oil is collected in a region where the arrow has a small length. In FIG. 8 , virtual lines (two-dot chain lines) indicate the respective oil levels in the large-depth portion c and small-depth portion b at the time when the vehicle starts running on the downhill, and solid lines indicate the respective oil levels in the large-depth portion c and small-depth portion b at the time when the vehicle has run on the downhill for a certain period of time. While the oil in the large-depth portion c is drawn up and the oil level in this portion c is lowered, as indicated by the solid line, a large portion of the oil collected into the oil pan o reaches the small-depth portion b without flowing into the large-depth portion c.
[0016] In the oil collecting condition as described above, a sufficient amount of oil may not be collected into the large-depth portion c unless the oil level of the oil collected into the small-depth portion b is elevated to be higher than the top edge of a ridge portion e between the small-depth portion b and the large-depth portion c (i.e., unless the oil overflows from the top edge of the ridge portion e into the large-depth portion c).
[0017] In the above-described case, while a sufficient amount of oil is collected in the oil pan o as a whole, a large portion of the oil collected is present in the small-depth portion b, and the amount of the oil stored in the large-depth portion c is extremely reduced, with the oil level being largely lowered, which may result in the “air sucking condition” as described above. This situation cannot be avoided through the use of the structures as disclosed in JP-A-8-189324 and JP-A-6-101568, and there still remains a concern about the occurrence of the air sucking condition.
[0018] In an engine having a relatively large displacement, which is installed on a vehicle, such as SU, in particular, a large-sized oil pan is employed, and its small-depth portion has a relatively large volume. Therefore, unless a large amount of oil is collected into the oil pan as a whole, the oil is unlikely to flow over the top edge of the ridge portion, from the small-depth portion into the large-depth portion, (i.e., the oil level is unlikely to be elevated to be higher than the top edge of the ridge portion). In a condition where a large amount of oil is collected in the small-depth portion, the oil level has already been largely lowered in the large-depth portion, which creates a high possibility of the occurrence of the air sucking condition.
SUMMARY OF THE INVENTION
[0019] It is an object of the invention to provide an oil pan structure for an oil pan including a small-depth portion and a large-depth portion, which ensures a sufficiently large amount of oil collected in the large-depth portion even in a situation where the oil pan is kept in an inclined state, so as to avoid the “air sucking condition”. It is another object of the invention to provide an internal combustion engine including the oil pan.
[0020] In an oil pan according to one aspect of the invention, the ridge portion includes a relatively low-level region that permits flowing of oil from the small-depth portion into the large-depth portion even in a situation where the oil level in the small-depth portion is relatively low, when the oil pan is in an inclined state in which the small-depth portion is shifted downward. With the low-level region provided in a part of the ridge portion, a sufficiently large amount of oil can be collected in the large-depth portion even when the oil pan is kept in the inclined state.
[0021] More specifically, an oil pan according to a first aspect of the invention is provided in a lower part of an internal combustion engine, and includes a small-depth portion having a bottom that is positioned at a high level, a large-depth portion formed adjacent to the small-depth portion and having a bottom that is positioned at a lower level than that of the small-depth portion, the large-depth portion defining an interior space in which an oil suction member is housed, and a ridge portion that connects a vertical wall that forms the large-depth portion with a bottom wall that forms the small-depth portion. In this oil pan, the ridge portion includes a first connecting portion that connects the vertical wall of the large-depth portion with the bottom wall of the small-depth portion via a curved surface, and a second connecting portion that connects the vertical wall of the large-depth portion with the bottom wall of the small-depth portion at a position lower than that of the first connecting portion.
[0022] An oil pan according to a second aspect of the invention is provided in a lower part of an internal combustion engine, and includes a small-depth portion having a bottom that is positioned at a high level, a large-depth portion formed adjacent to the small-depth portion and having a bottom that is positioned at a lower level than that of the small-depth portion, the large-depth portion defining an interior space in which an oil suction member is housed, and a ridge portion that connects a vertical wall that forms the large-depth portion with a bottom wall that forms the small-depth portion. In this oil pan, the ridge portion includes a first connecting portion and a second connecting portion. The first connecting portion connects an upper end of the vertical wall of the large-depth portion continuously with a distal end of the bottom wall of the small-depth portion, in a region in which the upper end of the vertical wall of the large-depth portion has a vertical position that is substantially equal to that of the bottom wall of the small-depth portion, and the distal end of the bottom wall of the small-depth portion lies at a position up to which the vertical wall of the large-depth portion rises. On the other hand, the second connecting portion connects the upper end of the vertical wall of the large-depth portion with the distal end of the bottom wall of the small-depth portion at a position lower than the first connecting portion, in a region in which the upper end of the vertical wall of the large-depth portion has a vertical position that is lower than that of the bottom wall of the small-depth portion, and the distal end of the bottom wall of the small-depth portion lies at a position that is retracted from a position up to which the vertical wall of the large-depth portion rises.
[0023] With the above arrangements, when the oil pan is not in an inclined state, such as when the vehicle is running on a flat road, a large portion of the oil in the oil pan is stored in the large-depth portion, and the oil that has been used for lubrication and cooling of various parts of the engine is collected into the large-depth portion and small-depth portion. Furthermore, the oil that has been collected in the small-depth portion quickly flows into the large-depth portion, thereby to ensure a sufficiently high level of the oil in the large-depth portion. Consequently, no “air sucking condition” occurs, namely, an oil inlet of an oil suction member (such as an oil strainer) is prevented from being exposed to the air.
[0024] When the oil pan is brought into an inclined state in which the small-depth portion is shifted downward, such as when the vehicle is running on a hill, a large portion of the oil that has been used for lubrication and cooling of various parts of the engine is collected into the small-depth portion due to its own weight. In the oil pan structure according to the first or second aspect of the invention, in which the second connecting portion that connects the vertical wall of the large-depth portion with the bottom wall of the small-depth portion at a relatively low position or level is provided in a portion of the ridge portion between the small-depth portion and the large-depth portion, the oil level in the small-depth portion easily goes beyond (i.e., becomes higher than) the second connecting portion, and the oil flow into the large-depth portion via the second connection portion, even in a situation where the oil level in the small-depth portion is relatively low, namely, where the amount of oil collected into the small-depth portion is relatively small. Thus, even when the oil pan is in the inclined state, the level of the oil in the large-depth portion is kept sufficiently high, and the occurrence of the “air sucking condition” in which the oil inlet of the oil suction member is exposed to the air is avoided.
[0025] Since the above-described effects are provided only by improving the shape of the oil pan, the freedom or flexibility in design of the oil pan is not reduced under influences of other components. Furthermore, the first connecting portion and the second connecting portion are formed as integral parts on the oil pan, thus making it possible to provide an oil pan with high practicality, without increasing the number of components of the oil pan or complicating the process of assembling the components into the oil pan.
[0026] The second connecting portion is provided only in a part of the ridge portion between the small-depth portion and the large-depth portion, and the remaining part of the ridge portion, i.e., the first connecting portion, formed with a curved surface having a certain radius of curvature connects the large-depth portion with the small-depth portion at a relatively high level or vertical position. Therefore, when the oil pan is not in an inclined state, flowing of the oil from the large-depth portion into the small-depth portion is effectively restricted or inhibited at a location where the first connecting portion is formed, and the first connecting portion contributes to establishment of a sufficiently high oil level in the large-depth portion.
[0027] According to the first or second aspect of the invention, the ridge portion as a boundary between the small-depth portion and large-depth portion of the oil pan includes, as a portion thereof, a relatively low-level region that permits flowing of the oil from the small-depth portion into the large-depth portion even in a situation where the oil pan is in an inclined state and the oil level in the small-depth portion is relatively low. Thus, even if the oil pan is kept in the inclined state, a sufficient amount of oil is surely collected in the large-depth portion, and the “air sucking condition” in which the oil inlet of the strainer is exposed to the air can be effectively avoided.
[0028] An internal combustion engine according to a third aspect of the invention includes an oil pan having the oil pan structure according to the first or second aspect of the invention.
[0029] In the internal combustion engine according to the third aspect of the invention, a sufficient amount of oil is surely collected in the large-depth portion even if the engine is kept in an inclined position, and the “air sucking condition” in which the oil inlet of the strainer is exposed to the air can be effectively avoided.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] The foregoing and further features and advantages of the invention will become apparent from the following description of example embodiments with reference to the accompanying drawings, wherein like numerals are used to represent like elements, and wherein:
[0031] FIG. 1 is a perspective view of an oil pan according to one embodiment of the invention;
[0032] FIG. 2 is an exploded perspective view of the oil pan;
[0033] FIG. 3A and FIG. 3B are cross-sectional views showing a condition in which an upper oil pan, a lower oil pan and an oil strainer are assembled together, wherein FIG. 3A is a cross-sectional view taken along line 3 A- 3 A in FIG. 1 , and FIG. 3B is a cross-sectional-view taken along line 3 B- 3 B in FIG. 1 ;
[0034] FIG. 4A is a view showing an automobile running on a flat road, and FIG. 4B is a cross-sectional view showing an oil storage condition in the oil pan during flat-road running of the automobile;
[0035] FIG. 5A is a view showing an automobile running on a downhill, and FIG. 5B is a cross-sectional view showing an oil storage condition in the oil pan during downhill running of the automobile;
[0036] FIG. 6 is a view corresponding to that of FIG. 3B , which shows an oil pan according to a modified example of the embodiment of FIG. 1 ;
[0037] FIG. 7 is a perspective view of an oil pan according to another modified example of the embodiment of FIG. 1 ; and
[0038] FIG. 8 is a cross-sectional view showing an oil storage condition in an oil pan of the related art, during downhill running of an automobile.
DETAILED DESCRIPTION OF EMBODIMENTS
[0039] One embodiment of the invention will be described with reference to the drawings. In this embodiment, the invention is applied to an oil pan provided in an engine that is installed on a SUV (Sport Utility Vehicle).
[0040] FIG. 1 is a perspective view of the oil pan 1 according to this embodiment of the invention, and FIG. 2 is an exploded perspective view of the oil pan 1 . As shown in FIG. 1 and FIG. 2 , the oil pan 1 consists of an upper oil pan 2 made of an aluminum alloy, and a lower oil pan 3 made of iron, which are assembled together into an integral structure. For example, the upper oil pan 2 is formed by casting, and the lower oil pan 3 is formed by sheet-metal stamping. It is to be understood that the materials of the upper oil pan 2 and the lower oil pan 3 and the methods of working thereof are not limited to those as described above.
[0041] Referring to FIG. 2 , an oil strainer 4 through which oil stored in the lower oil pan 3 is drawn up is housed in the lower oil pan 3 . The oil strainer 4 is connected to an inlet of an oil pump that is driven with engine power. With this arrangement, as the oil pump is driven, the oil in the lower oil pan 3 is drawn up via the oil strainer 4 , to be fed under pressure to various parts of the engine and used for lubrication or cooling of these parts. The oil that has been used for lubrication or cooling of the engine parts drops into the oil pan 1 and is collected in the oil pan 1 for reuse.
[0042] FIG. 3A is a cross-sectional view taken along line 3 A- 3 A in FIG. 1 , showing a condition in which the upper oil pan 2 , lower oil pan 3 and the oil strainer 4 are assembled together.
[0043] As shown in FIG. 3A , the upper oil pan 2 is attached to a lower surface of a cylinder block (not shown), and is formed with a mounting flange 21 that extends over the entire circumference of the top edge thereof at which the upper oil pan 2 is attached to the cylinder block. Also, mounting holes 21 a adapted to receive mounting bolts are formed at a plurality of locations of the mounting flange 21 , as shown in FIG. 1 .
[0044] The upper oil pan 2 includes a wall portion 22 that extends from the inner edge of the mounting flange 21 downwards in a generally vertical direction. The vertical position of the lower end of the wall portion 22 is set at substantially the same level over the entire circumference of the upper oil pan 2 . The upper oil pan 2 further includes a bottom portion 23 that extends inwards from the lower end of the wall portion 22 in a substantially horizontal direction (i.e., extends in a horizontal direction when the vehicle runs on a flat road and the oil pan 1 is not inclined). The bottom portion 23 may be slightly inclined downwards toward an opening 24 that will be described later.
[0045] The opening 24 having a relatively large diameter is formed in a rear portion of the bottom portion 23 of the upper oil pan 2 as viewed in the longitudinal direction of the vehicle, such that the opening 24 extends through the bottom portion 23 in the direction of the thickness (i.e., vertical direction) thereof. As described later, the opening 24 communicates with the interior space of the lower oil pan 3 .
[0046] The upper oil pan 2 further includes a vertical wall portion 25 formed generally in the shape of a flattened cylinder at the periphery of the opening 24 , such that the vertical portion 25 extends continuously from the bottom portion 23 . The shape or configuration of a connecting portion that connects the vertical wall portion 25 with the bottom portion 23 will be described in detail later. In addition, a flange 26 to be joined to the top edge of the lower oil pan 3 is formed at the bottom edge of the vertical wall portion 25 .
[0047] Thus, the upper oil pan 2 is formed as an oil storage container or reservoir having a relatively small depth.
[0048] On the other hand, the lower oil pan 3 is joined to the lower end of the vertical wall portion 25 that is formed integrally with the bottom portion 23 of the upper oil pan 2 , so as to communicate with the opening 24 . More specifically, the shape of the lower oil pan 3 as viewed in a horizontal plane is substantially identical with the shape of the periphery of the opening 24 , and a mounting flange 31 to be attached to the upper oil pan 2 is formed over the entire circumference of the top edge of the lower oil pan 3 . Also, mounting holes 31 a , 31 a , . . . adapted to receive mounting bolts are formed at a plurality of locations of the mounting flange 31 , as shown in FIG. 2 .
[0049] The lower oil pan 3 includes a wall portion 32 that extends from the inner edge of the mounting flange 31 downwards in a generally vertical direction. The vertical dimension, or height, of the wall portion 32 is set to be relatively large, so as to increase the volume of the interior of the lower oil pan 3 . The lower oil pan 3 further includes a bottom portion 33 that extends inwards from the lower end of the wall portion 32 in a generally horizontal direction (i.e., extends in a horizontal direction when the vehicle runs on a flat road and the oil pan 1 is not inclined).
[0050] Thus, the lower oil pan 3 is formed as an oil storage container or reservoir having a relatively large depth. The lower oil pan 3 is located at a rear portion of the bottom portion 23 of the upper oil pan 2 as viewed in the longitudinal direction of the vehicle, so as to avoid interference with a driveshaft that extends below the oil pan 1 in the vehicle-width direction. The virtual line (two-dot chain line) in FIG. 3A indicates the position at which the driveshaft is installed. Thus, the lower oil pan 3 serving as a large-depth oil storage container is provided in a part of the oil pan 1 , so as to ensure a large amount of oil stored in the oil pan 1 while avoiding interference of the oil pan 1 with the driveshaft.
[0051] As described above, the lower oil pan 3 is joined to the lower end of the upper oil pan 2 , to form the oil pan 1 . Therefore, the interior space of the oil pan 1 has a small-depth portion 5 having a bottom that is positioned at a relatively high level, and a large-depth portion 6 having a bottom that is positioned at a level lower than that of the small-depth portion 5 , as shown in FIGS. 3A and 3B . In this embodiment, the small-depth portion 5 is constituted by the wall portion 22 and bottom portion 23 of the upper oil pan 2 , and the large-depth portion 6 is constituted by the vertical wall portion 25 of the upper oil pan 2 and the lower oil pan 3 .
[0052] The present embodiment is characterized by the shape of a ridge portion 7 as a connecting portion that connects the small-depth portion 5 with the large-depth portion 6 , namely, a connecting portion that connects the bottom portion 23 and vertical wall portion 25 of the upper oil pan 2 with each other.
[0053] As shown in FIG. 1 and FIG. 2 , the ridge portion 7 includes a first connecting portion 71 that extends from one end of the ridge portion 7 as viewed in the longitudinal direction thereof (i.e., the vehicle-width direction in this embodiment) to a middle portion thereof, and a second connecting portion 72 formed only in the other longitudinal end portion of the ridge portion 7 . For example, where the ridge portion 7 has a dimension of 500 mm as measured in the longitudinal direction, the longitudinal dimension of its region in which the first connecting portion 71 is formed is 400 mm, and the longitudinal dimension of its region in which the second connecting portion 72 is formed is 100 mm. The dimensions and the ratio of the dimensions are not limited to those of this example.
[0054] FIG. 3A is a cross-sectional view taken along line 3 A- 3 A in FIG. 1 , as described above, and shows a section of the first connecting portion 71 . On the other hand, FIG. 3B is a cross-sectional view taken along line 3 B- 3 B in FIG. 1 , and shows a section of the second connecting portion 72 .
[0055] In the first connecting portion 71 as shown in FIG. 3A , the upper end of the vertical wall portion 25 that constitutes the large-depth portion 6 is located at the same level as that of the bottom portion 23 that constitutes the small-depth portion 5 . In a region where the distal end of the bottom portion 23 is located at a position up to which the vertical wall portion 25 rises in the vertical direction, a curved surface having a certain radius of curvature (e.g., a radius of 10 mm) is formed so as to connect the upper end of the vertical wall portion 25 with the distal end of the bottom portion 23 .
[0056] In the second connecting portion 72 , on the other hand, the upper end of the vertical wall portion 25 that constitutes the large-depth portion 6 is located at a level lower than that of the bottom portion 23 that constitutes the small-depth portion 5 , as shown in FIG. 3B . In a region where the distal end of the bottom portion 23 is located at a position retracted (i.e., shifted to the right in FIG. 3B ) from the position up to which the vertical wall portion 25 rises in the vertical direction, the second connecting portion 72 is formed with an inclined surface (slope) that connects the lower-level upper end of the vertical wall portion 25 with the distal end of the bottom portion 23 located at the retracted position. Namely, the second connecting portion 72 is shaped so as to connect the vertical wall portion 25 of the large-depth portion 6 with the bottom portion 23 of the small-depth portion 5 , at a position lower than that of the first connecting portion 71 .
[0057] Next, oil storage conditions of the oil pan 1 according to this embodiment of the invention will be described. In the following description, an oil storage condition observed when the automobile runs on a flat road, and an oil storage condition observed when the automobile runs on a downhill will be explained.
[0058] When an automobile C runs on a flat road, as shown in FIG. 4A , the oil pan 1 is not inclined, and a large portion of the oil in the oil pan 1 is stored in the large-depth portion 6 constituted by the vertical wall portion 25 of the upper oil pan 2 and the lower oil pan 3 , as shown in FIG. 4B . In this condition, the oil that has been used for lubrication and cooling of various parts of the engine is substantially evenly collected into the lower oil pan 3 and the upper oil pan 2 (as indicated by arrows in FIG. 4B ). Also, the oil collected into the small-depth portion 5 constituted by the wall portion 22 and bottom portion 23 of the upper oil pan 2 flows quickly into the lower oil pan 3 , so that a sufficiently high oil level is surely established in the large-depth portion 6 . Consequently, an oil inlet of the oil strainer 4 is prevented from being exposed to the air, namely, the oil pump is not brought into the “air sucking condition” as described above.
[0059] When the automobile C runs on a downhill, as shown in FIG. 5A , the oil pan 1 is inclined as shown in FIG. 5B , and a large portion of the oil that has been used for lubrication and cooling of various parts of the engine is collected, due to its own weight, toward the bottom portion 23 of the upper oil pan 2 . Namely, a large portion of the oil is collected into the small-depth portion 5 of the oil pan 1 (as indicated by arrows in FIG. 5B , in which the length of the arrow represents the amount of oil collected in each region). This is because the oil flows down, under its own weight, along the inner walls of the cylinder block and the outer surface of the crankshaft, toward the front side of the vehicle body.
[0060] In this embodiment, a part of the ridge portion 7 between the small-depth portion 5 and the large-depth portion 6 is formed as the second connecting portion 72 that connects the vertical wall portion 25 of the large-depth portion 6 with the bottom portion 23 of the small-depth portion 5 at a relatively low level. In the above-described situation as shown in FIG. 5A and FIG. 5B , therefore, the oil level in the small-depth portion 5 becomes higher than the second connecting portion 72 even in a condition where the oil level in the small-depth portion 5 is relatively low, namely, even when the amount of oil collected into the small-depth portion 5 is relatively small, so that the oil starts flowing into the large-depth portion 6 over the second connecting portion 72 .
[0061] In FIG. 5B , the solid line indicates an oil level which the oil in the small-depth region 5 reaches when the oil starts flowing from the small-depth portion 5 into the large-depth portion 6 in this embodiment. On the other hand, the virtual line (two-dot chain line) in FIG. 5B indicates an oil level which the oil in a small-depth region reaches when the oil starts flowing from the small-depth portion into a large-depth portion in an oil pan of the related art. As is understood from a comparison between these lines, in (the oil pan 1 of) this embodiment, the second connecting portion 72 allows the oil to flow from the small-depth portion 5 into the large-depth portion 6 , even in a condition where the oil level in the small-depth portion 5 is relatively low. In FIG. 5B , the one-dot chain line indicates the shape or profile of the ridge portion of the oil pan according to the related art.
[0062] Thus, in this embodiment, even when the oil pan is in an inclined state, a sufficiently high oil level is surely established in the large-depth portion 6 , and the “air sucking condition” in which the oil inlet of the oil strainer 4 is exposed to the air is avoided. Namely, it is possible to effectively avoid the “air sucking condition” as described above merely by changing the shape or configuration of the oil pan 1 . While the lubricating oil may fail to be introduced into the oil pump and the operation to circulate the oil may not be smoothly carried out if the “air sucking condition” occurs, this situation can be avoided in this embodiment. Also, since various sliding parts in a pumping mechanism of the oil pump are held in well-lubricated conditions, wear of the components that constitute the oil pump is prevented, and good sealing is provided at sealed regions, thus assuring high reliability of the oil pump.
[0063] Since the above-described effects are provided only by improving the shape of the oil pan 1 , as described above, the freedom or flexibility in design of the oil pan is not reduced under influences of other components that would otherwise be incorporated into the oil pan. Furthermore, the first connecting portion 71 and the second connecting portion 72 are formed as integral parts on the oil pan 1 , thus making it possible to provide the oil pan 1 with high practicality, without increasing the number of components of the oil pan 1 or complicating the process of assembling the components into the oil pan 1 .
[0064] The second connecting portion 72 is provided only in a part of the ridge portion 7 between the small-depth portion 5 and the large-depth portion 6 , and the remaining part of the ridge portion 7 , i.e., the first connecting portion 71 , formed with a curved surface having a suitable radius of curvature connects the large-depth portion 5 with the small-depth portion 6 at a relatively high level (i.e., at a position higher than that at which the second connecting portion 72 connects the large-depth portion with the small-depth portion 6 ). Therefore, when the oil pan 1 is not in an inclined state, flowing of the oil from the large-depth portion 6 into the small-depth portion 5 is effectively restricted or inhibited at a location where the first connecting portion 71 is formed, and the first connecting portion 71 contributes to establishment of a sufficiently high oil level in the large-depth portion 6 .
[0065] In the illustrated embodiment, the second connecting portion 72 is formed with the inclined surface (or slope). As a modified example of the embodiment, the second connecting portion 72 may be formed with a stepped portion shaped like stairs as shown in FIG. 6 (a cross-sectional view corresponding to that of FIG. 3B ), in place of the inclined surface.
[0066] In this case, too, the second connecting portion 72 that connects the vertical wall portion 25 of the large-depth portion 6 with the bottom portion 23 of the small-depth portion 5 at a relatively low level is formed in a part of the ridge portion 7 between the small-depth portion 5 and the large-depth portion 6 , so that effects similar to those of the illustrated embodiment are provided.
[0067] In the illustrate embodiment, the second connecting portion 72 is formed in one longitudinal end portion of the ridge portion 7 . As another modified example of the illustrated embodiment, the second connecting portion 72 may be formed in a longitudinally middle portion of the ridge portion 7 as shown in FIG. 7 (a view corresponding to that of FIG. 1 ), and first connecting portions 71 , 71 may be formed on the opposite sides of the second connecting portion 72 .
[0068] While the second connecting portion 72 shown in FIG. 7 is formed with an inclined surface (or slope) as in the illustrated embodiment, the second connecting portion 72 may be formed as a stepped portion shaped like stairs as in the above-described modified example.
[0069] In the illustrated embodiment and its modified examples, the invention is applied to the oil pan 1 provided in the engine installed on the SUV. It is, however, to be understood that the present invention is not limited to this application, but may be applied to oil pans provided in engines installed on other types of vehicles. Also, the engine on which the oil pan according to the invention is installed is not particularly limited, but the invention may be applied to oil pans installed on various types of engines, such as gasoline engines and diesel engines, or engines having various cylinder arrangements, such as in-line engines, V-type engines and horizontal opposed engines, with no regard to the number of cylinders.
[0070] While the oil pan 1 is of a split type consisting of the upper oil pan 2 and the lower oil pan 3 in the illustrated embodiment and its modified examples, the invention may be equally applied to an oil pan in which the small-depth portion 5 and the large-depth portion 6 are formed as an integral body.
[0071] In the illustrated embodiment and its modified examples, the invention is applied to the oil pan 1 in which the lower oil pan 3 is provided in a rear portion of the bottom portion 23 of the upper oil pan 2 as viewed in the longitudinal direction of the vehicle. However, the invention is not limited to this arrangement, but may be applied to an oil pan in which the lower oil pan 3 is provided in a front portion of the bottom of the upper oil pan 2 as viewed in the longitudinal direction of the vehicle. In this case, when the vehicle runs on an uphill, the oil in the small-depth portion 5 is collected into the large-depth portion 6 via the second connecting portion 72 , so as to provide the effect of the invention, namely, to ensure a sufficiently high oil level in the large-depth portion 6 .
[0072] While the invention has been described with reference. to example embodiments thereof, it is to be understood that the invention is not limited to the described embodiments or constructions. To the contrary, the invention is intended to cover various modifications and equivalent arrangements. In addition, while the various elements of the example embodiments are shown in various combinations and configurations, other combinations and configurations, including more, less or only a single element, are also within the spirit and scope of the invention.
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An oil pan structure for an internal combustion engine includes: a small-depth portion having a bottom that is positioned at a high level; a large-depth portion formed adjacent to the small-depth portion and having a bottom that is positioned at a lower level than that of the small-depth portion, said large-depth portion defining an interior space in which an oil suction member is housed; and a ridge portion that connects a vertical wall that forms the large-depth portion with a bottom wall that forms the small-depth portion. The ridge portion includes a first connecting portion that connects the vertical wall of the large-depth portion with the bottom wall of the small-depth portion via a curved surface, and a second connecting portion that connects the vertical wall of the large-depth portion with the bottom wall of the small-depth portion at a position lower than that of the first connecting portion.
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This application claims the benefit of the Korean Application No. P 2002-45349 filed on Jul. 31, 2002, which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
Embodiments of the present invention generally relates to communications.
2. Background of the Related Art
The development of both mobile networks (e.g., cellular phone networks) and the Internet have revolutionized lifestyles of many people. However, as these technologies have developed, some criminal problems have arisen. For example, on the Internet, illegal information (e.g., terrorist communications, child pornography, and computer hacking) may be prohibited. Accordingly, police agencies may have a desire to track illegal Internet use to physical locations, so that criminals can be apprehended. If police are able to track illegal Internet use, criminal behavior and the effects of criminal behavior can be mitigated.
Mobile communications is another developing area of technology that has criminal problems. For example, cellular phones can be used by criminals to communicate during commission of a crime. Technologies have been developed to trace cellular telephone calls to mitigate crimes. Recently, Internet communication systems have been merged with cellular phones. Although there are many advantages to this merger, there may be an increase in criminal problems. For instance, a criminal can perform illegal Internet usage on a mobile phone, making it difficult for police to track the criminal and/or the location of the illegal Internet usage. Accordingly, there is a long felt need to have the ability to track Internet usage on cellular phones.
SUMMARY OF THE INVENTION
Embodiments of the present invention relate to searching a mobile communication system (e.g., a cellular telephone network) for use of a network address (e.g., an Internet address). Embodiments of the invention have many advantages, as police or cellular service providers may be able to track or trace illegal Internet usage to a particular cellular telephone. For example, if a terrorist is communicating to other terrorists over the Internet, using his/her cellular telephone, the police may be able to associate the illegal Internet usage with the mobile telephone. Accordingly, in this example, the police may be able to locate the terrorists and detain him/her before they can cause harm to innocent individuals. One of ordinary skill in the art would appreciate other advantages of being able to search a mobile communication system for use of a network address.
Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objects and advantages of the invention may be realized and attained as particularly pointed out in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exemplary block diagram of a circuit-type mobile communication system.
FIG. 2 is an exemplary block diagram of a packet-type mobile communication system.
FIG. 3 is an exemplary view illustrating a signal transmitting/receiving process among blocks in the packet-type mobile communication system.
FIG. 4 is an exemplary view illustrating a signal flow.
FIG. 5 is an exemplary flowchart illustrating a packet call tracing and monitoring operation.
FIG. 6 is an exemplary flowchart illustrating activating packet call tracing and monitoring.
FIG. 7 is an exemplary flowchart illustrating inactivating packet call tracing and monitoring.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
As mobile Internet services are spreading with the development of data communications, illegal uses of the Internet or cyber crimes on the Internet are increasing. Accordingly, call tracing and monitoring of subscribers may be required in order to control illegal use of the Internet or cyber crimes on the Internet. Call tracing is a function of tracing a shift of a call state or a possession/release process of resources which are related to a call. Call tracing may be performed with respect to the subscribers or trunks. Information on the subscribers and the trunks subject to tracing may be registered in a call-tracing database. Call monitoring may be a function of outputting, to an operator terminal, particulars related to a call of a specified subscriber. Monitoring of the call may be required when the call is produced and registered in the same tracing database as the call tracing function.
A mobile communication switch may be divided into a packet switch and a circuit switch. A packet switch may take charge of a packet service such as an Internet connection. A circuit switch that takes charge of a service, such as an existing telephone network connection, in accordance with the kind of service. In a mobile communication network, call tracing and monitoring may be performed with respect to the circuit service and the audio-oriented call. Call tracing and monitoring may be used for call tracing and monitoring in a mobile communication system using a signaling system.
FIG. 1 is an example block diagram of a circuit-type mobile communication system The circuit-type mobile communication system may include a public switched telephone network (PSTN) 11 an integrated services digital network (ISDN) 12 , a mobile switch center (MSC) 13 , a radio network subsystem (RNS) 14 , a mobile station (MS) 15 , an hour location register (HLR) 16 , a visitor location register (VLR) 17 , a MSC management center 18 , and an RNS management center 19 . PSTN 11 may be for a general subscriber telephone service provided by a communication network provider. ISDN 12 may be for digitalizing and transmitting a communication service including a telephone service through one subscribed line.
MSC 13 , which may be connected between PSTN 11 and ISDN 12 , may be for performing circuit switching and exchange call processing among mobile communication subscribers so that the mobile communication subscribers can receive services. RNS 14 may be for providing allocation of radio resources and handoff functions to MS 15 . HLR 16 may be for managing subscription information and position information of the mobile communication subscribers. VLR 17 may be for bringing subscriber information from HLR 16 in order to search for information for processing a call request produced from a visitor subscriber of another communication network and performing an authentication. MSC management center 18 and RNS management center 19 , which may be connected to MSC 13 and RNS 14 , respectively, may be for performing a call tracing and monitoring in a circuit-oriented mobile communication system.
Circuit-oriented mobile communication systems may provide wire and radio services to mobile communication subscribers using PSTN 11 and/or ISDN 12 . PSTN 11 may be used for general subscriber telephone service provided by a communication network provider. ISDN 12 may be used for digitalizing and transmitting communication services including the telephone service through one subscribed line. MSC 13 may perform circuit switching and switched call processing among subscribers so that mobile communication subscribers can receive services. RNS 14 may provide allocation of radio resources and handoff function to MS 15 . HLR 16 may contain two kinds of information (e.g., subscriber information and position information of mobile communication subscribers) in order to take charge of management of mobile communication subscribers. HLR 16 may designate a path of a terminating call to the MS 15 . VLR 17 may bring subscriber information from HLR 16 in order to search for information for processing a call request produced from a visitor subscriber of another communication network and perform authentication.
Call tracing and monitoring may be performed by MSC management center 18 or RNS management center 19 in a circuit-oriented mobile communication system. If the number of subscribers subject to tracing and monitoring are inputted, a protocol processor of MSC 13 and/or the RNS 14 may activate call tracing and monitoring with respect to the inputted subscriber's numbers. A number may be allocated to a subscriber or a subscriber's mobile station as an identifier of a subscriber subject to call tracing and monitoring. The allocated number may be an international mobile communication subscriber identity (IMSI) or an electronic serial number (ENS).
In order to perform tracing and monitoring of a subscriber, a signal message transmitted and received at MSC 13 may be analyzed. During transmission of a signal message, a message transfer part layer2 (TP2), a message transfer part3 (MTP3), and a signal connection control part (SCCP) may be used as a protocol. By analyzing such a protocol, call tracing and monitoring of a mobile communication subscriber may be performed. A circuit type mobile communication service may allocate channels to respective subscribers who perform communications one by one. If there are many subscribers, many channels may be secured. For example, during use of the radio frequency resources as communication channels, a plurality of subscribers may not simultaneously successfully perform communications due to limited radio frequency resources.
Subscribers allocated with communication channels may not be able to continuously transmit communication data in a state that they possess the allocated channels. However, there may be a lot of idle or standby time when data is not transmitted, which may degrade efficient use of a corresponding channel. Packet type mobile communication service may enable a plurality of subscribers to simultaneously perform communication using one channel. Without additional protocols, this service may not be able to provide packet call tracing and monitoring of mobile communication subscribers who use the packet service (e.g., Internet service). Since mobile communication subscribers may not use an identifier (e.g., IMSI or ESN) in an Internet protocol network, it may become impossible to perform the call tracing and monitoring with respect to the subscribers who use only an IP address as a service identifier on the Internet. Accordingly, embodiments of the present invention relate to a mobile communication system that provides packet service and packet call tracing/monitoring. In embodiments, an IP address is used as an identifier of a mobile communication subscriber.
FIG. 2 is an exemplary block diagram of a packet-type mobile communication system. A packet-type mobile communication system may include an Internet protocol (IP) network 24 , a gateway general packet radio service GPRS support node (GGSN) 25 , a serving GPRS support node 23 , a radio network subsystem (RNS) 22 , a home location register (HLR) 26 , a network management center 27 , and/or a radio network subsystem (RNS) management center 28 .
GGSN 25 may perform a function of a gateway for connecting to the IP network 24 . SGSN 23 may be connected to GGSN 24 through a GPRS network. GGSN 25 may manage the mobility of mobile station 21 in packet mode. GGSN 25 may perform functions of a packet switch. HLR 26 may be connected to SGSN 23 and may manage subscription information and position information of packet service subscribers. RNS 22 may manage radio resources and may perform data transmission/reception with mobile station 21 by allocating a traffic channel. Network management center 27 and RNS management center 28 may perform a packet call tracing and/or monitoring functions.
A mobile communication subscriber may receive Internet service through GGSN 25 . In order for mobile station (MS) 21 to connect to an IP network, MS 21 may be assigned an IP address that is used as a service identifier on the Internet. Two methods of allocating an IP address are to allocate a static IP address in advance and to dynamically allocate an IP address in a communication network when a subscriber requests a packet call.
Embodiments of the present invention relate to tracing and monitoring a packet call of a mobile communication subscriber. FIG. 3 is an exemplary view illustrating a signal transmitting/receiving process among blocks in a packet-type mobile communication system according to embodiments of the present invention. FIG. 4 is an exemplary view illustrating a signal flow according to embodiments of the present invention.
If illegal use of the Internet or a cyber crime is detected on IP network 24 , a National Police Agency or a similar agency may transfer information to the network management center 27 relating to a target IP address for tracing and monitoring (step 401 ). Network management center 27 may request tracing and monitoring of the target IP address to SGSN 23 (step 402 ). SGSN 23 , which may have received a request for tracing and monitoring, may perform tracing and monitoring of the target IP address and transmit results of the target IP address tracing and monitoring to network management center 27 (step 403 ). Accordingly, tracing and monitoring of a mobile communication subscriber may be possible.
FIG. 5 is a flowchart illustrating a packet call tracing and monitoring operation according to embodiments of the present invention. If a specified IP address is illegally used on an IP network and a request for tracing and monitoring of the specified IP address is transferred from a policing agency to network management center 27 (step S 501 ), then network management center 27 may request SGSN 23 to activate tracing and monitoring of a target IP address (step S 502 ).
SGSN 23 , responsive to receiving a tracing and monitoring activation request message, may check whether a target IP address is an effective IP address in a network to which the subscriber belongs (step S 503 ). If it is confirmed that the target IP address is not an effective IP address in the network, SGSN 23 may return the system to a state before the request for tracing and monitoring of the corresponding target IP address is produced in the IP network so that the request for tracing and monitoring of the corresponding target IP address is ignored. If it is confirmed that the target IP address is the effective IP address, then SGSN 23 may activate call tracing and monitoring of the target IP address (step S 504 ). SGSN 23 may then perform packet call tracing and monitoring of the target IP address (step S 505 ).
Performing packet call tracing and monitoring (step S 505 ) may include checking for a request and change of packet call, a request for release of a packet call, or other protocols which involve messages transmitted between SGSN 23 and mobile station (MS) 21 . SGSN 23 may collect and periodically transmit to network management center 27 results obtained through packet call tracing and monitoring (step S 506 ). SGSN 23 may inactivate tracing and monitoring functions (step S 507 ) to complete packet call tracing and monitoring.
FIG. 6 is an exemplary flowchart illustrating activating packet call tracing and monitoring of a target IP address of FIG. 5 . If a target IP address subject to activation of the tracing and monitoring is input into SGSN 23 through an operator terminal of network management center 27 (step S 601 ), SGSN 23 may check whether a packet call having the target IP address exists in a packet data protocol (PDP) context database stored of SGSN 23 (step S 602 ). If it is confirm that a packet call having a target IP exists in a PDP context database, SGSN 23 may start packet call tracing and monitoring of the target IP address (step S 603 ).
If it is determined that a packet call having a target IP address does not exist in a PDP context database, then SGSN 23 may set a trigger flag for the target IP (step S 604 ) in order to trace and monitor the packet call. SGSN 23 may check whether a packet call having the IP address included in the trigger flag exists in the PDP context database (step S 602 ). If it is confirmed that a packet call having the IP address included in the trigger flag exists in the PDP context database, then SGSN 23 may start packet call tracing and monitoring of the IP address (step S 603 ). Packet call tracing and monitoring may be performed for messages transmitted between SGSN 23 and mobile station (MS) 21 .
For example, a message transmitted between SGSN 23 and mobile station (MS) 21 may be an active PDP context request message that is transmitted from the mobile station 21 to the SGSN 23 or an active PDP context acceptance message that is transmitted from the SGSN 23 to the mobile station 21 . An IP address may be used as an identifier of such messages. SGSN 23 may collect and periodically transmit results of packet call tracing and monitoring to network management center 27 .
FIG. 7 is an exemplary flowchart illustrating inactivating packet call tracing and monitoring of FIG. 5 . If a target IP address subject to inactivation of tracing and monitoring is inputted into SGSN 23 through an operator terminal of network management center 27 (step S 701 ), SGSN 23 may determine whether tracing and monitoring of the target IP address is in an active state or in an inactive state (step S 702 ). If it is determined that tracing and monitoring of a target IP address is in an active state, then SGSN 23 may terminate the activation and transmit results of the inactivation to an operator terminal of network management center 27 (step S 703 ).
If it is determined that call tracing and monitoring of a target IP address is in an inactive state, then SGSN 23 may determine whether a trigger flag for tracing and monitoring of the target IP address is set (step S 704 ). If it is determined that a trigger flag is set, SGSN 23 may remove the trigger flag (step S 705 ) and may terminate tracing and monitoring. The trigger flag may be removed to prevent errors if a packet call of the trigger IP address exists in a PDP context database. If it is determined that a trigger flag for packet call tracing and monitoring of a target IP address is not set, SGSN 23 may return the mobile communication system to a state before a target IP address subject to the inactivation was inputted to network management center 27 . In embodiments of the present invention, a function of SGSN 23 may be performed by GGSN 25 . Operation and effect of other function blocks of GGSN 25 may be similar to SGSN 23 .
In embodiments of the present invention, packet call tracing and monitoring in a mobile communication system may have several advantages. For example, if it is required to trace and monitor a packet call of a mobile communication subscriber who has connected to the Internet, embodiments of present invention may perform the packet call tracing and monitoring using the IP address of subscriber. Accordingly, because illegal use of the Internet or cyber crimes on the Internet are increasing with the spread of mobile Internet services, it may be possible to perform tracing and monitoring of a packet subscriber in order to control the illegal use of the Internet or the cyber crime on the Internet.
Embodiments of the present invention relate to a method of tracing and monitoring a call in a mobile communication system. An object of embodiments of the present invention is to provide a method of tracing and monitoring a call in a mobile communication system that enables the tracing and monitoring of a packet call of a mobile communication subscriber. A method of tracing and monitoring a call in a mobile communication system according to embodiments of the present invention performs the tracing and monitoring of the packet call of the mobile communication subscriber using an Internet protocol (IP) of an Internet subscriber.
Embodiments relate to a method of tracing and monitoring a call in a mobile communication system provided with a network management center and a serving general packet radio service (GPRS) support node (SGSN), includes a first step of a related agency transmitting a target Internet protocol (IP) subject to a request for tracing and monitoring to the network management center of the mobile communication system, a second step of the network management center requesting a packet call tracing and monitoring of the target IP to the SGSN, and a third step of the SGSN tracing and monitoring the packet call of the target IP and transmitting a result of the packet call tracing and monitoring to the network management center.
In embodiments, the third step includes the steps of checking whether the target IP is an effective IP in a network to which the corresponding subscriber belongs, if it is checked that the target IP is the effective IP, activating the call tracing and monitoring of the target IP, and performing the packet call tracing and monitoring and transmitting the result of the packet call tracing and monitoring.
The method of tracing and monitoring the call according to embodiments of the present invention further includes the step of if it is checked that the target IP is not the effective IP in the network to which the corresponding subscriber belongs, returning the system to a state before the request for tracing and monitoring of the target IP is produced in the IP network. In embodiments, the step of activating the packet call tracing and monitoring of the target IP includes the steps of the SGSN judging whether the packet call having the target IP exists in a packet data protocol context database stored in the SGSN, and if it is judged that the packet call having the target IP exists in the packet data protocol context database, starting the packet call tracing and monitoring of an address of the target IP.
In embodiments, the step of activating the call tracing and monitoring of the target IP further includes the steps of if it is judged that the packet call having the target IP does not exist in the packet data protocol context database, setting a trigger flag of the target IP address, and if the packet call having an IP with the set trigger flag exists in the packet data protocol context database, starting the packet call tracing and monitoring of the corresponding IP. In embodiments, the step of performing the packet call tracing and monitoring is a step of the SGSN checking whether a request and change of the packet call, a request for release of the packet call, etc., are produced with respect to a message that the SGSN transmits to and receives from a mobile station.
In embodiments, the message that the SGSN transmits to and receives from the mobile station may include an active PDP context request message that is transmitted from the mobile station to the SGSN and an active PDP context request response message that is transmitted from the SGSN to the mobile station. In embodiments, at the third step, the SGSN periodically transmits the result of the packet call tracing and monitoring to the network management center.
The method of tracing and monitoring the call according to embodiments of the present invention further includes a fourth step of the SGSN inactivating the packet call tracing and monitoring after the third step. The fourth step of inactivating the packet call tracing and monitoring of the target IP includes the steps of the SGSN receiving input of the target IP subject to inactivation through the network management center, checking whether the packet call tracing and monitoring of the target IP is in an active state, and if it is checked that the packet call tracing and monitoring of the target IP is in the active state, terminating the activation and transmitting a result of the inactivation.
In embodiments, the fourth step of inactivating the packet call tracing and monitoring of the target IP further includes the steps of if it is checked that the packet call tracing and monitoring corresponding to the target IP is in an inactive state, checking whether a trigger flag for the tracing and monitoring of the target IP is set, and if it is checked that the trigger flag is set, removing the trigger flag and terminating the tracing and monitoring work. The fourth step of inactivating the packet call tracing and monitoring of the target IP further includes the step of if it is checked that the trigger flag for the call tracing and monitoring of the target IP is not set, returning the mobile communication system to a state before an address of the target IP subject to inactivation is inputted to the network management center.
In embodiments of the present invention, a method of tracing and monitoring a call in a mobile communication system provided with a network management center and a gateway general packet radio service (GPRS) support node (GGSN), includes a first step of a related agency transmitting a target Internet protocol (IP) subject to a request for tracing and monitoring to the network management center of the mobile communication system, a second step of the network management center requesting a packet call tracing and monitoring of the target IP to the GGSN, and a third step of the GGSN tracing and monitoring the packet call of the target IP and transmitting a result of the packet call tracing and monitoring to the network management center.
The foregoing embodiments and advantages are merely exemplary and are not to be construed as limiting the present invention. The present teaching can be readily applied to other types of apparatuses. The description of the present invention is intended to be illustrative, and not to limit the scope of the claims. Many alternatives, modifications, and variations will be apparent to those skilled in the art.
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Embodiments of the present invention relate to searching a mobile communication system (e.g., a cellular telephone network) for use of a network address (e.g., an Internet address). Embodiments of the invention have many advantages, as police or cellular service providers may be able to track or trace illegal Internet usage to a particular cellular telephone. For example, if a terrorist is communicating to other terrorists over the Internet, using his/her cellular telephone, the police may be able to associate the illegal Internet usage with the mobile telephone. Accordingly, in this example, the police may be able to locate the terrorists and detain him/her before they can cause harm to innocent individuals. One of ordinary skill in the art would appreciate other advantages of being able to search a mobile communication system for use of a network address.
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CROSS REFERENCE
[0001] The present application is a divisional of U.S. application Ser. No. 13/190,904, filed Jul. 26, 2011, which claims the benefit of priority to U.S. Provisional No. 61/367,706, filed Jul. 26, 2010, and to U.S. Provisional No. 61/510,607, filed Jul. 22, 2011, the disclosures of which are hereby incorporated by reference.
GOVERNMENT SUPPORT
[0002] This invention was made with government support under W911 NF-06-1-0377 awarded by the U.S. Army Research Office. The government has certain rights in the invention.
TECHNICAL FIELD
[0003] The present application may relate to the use of materials for managing the propagation characteristics of electromagnetic waves incident thereon.
[0004] The present application may relate to the use of materials for managing the propagation characteristics of electromagnetic waves incident thereon.
BACKGROUND
[0005] While the theoretical concept of “black body” radiation has proved remarkably useful for modern science and engineering, from its role in the creation of quantum mechanics to its applications to actual light sources, few actual materials or structures come close to 100% absorption for all angles over a broad bandwidth. Even though many applications would greatly benefit from such a perfect absorber, from cross-talk reduction in optoelectronic devices to thermal light emitting sources to solar light harvesting, as examples, a perfect absorber has remained elusive. Herein, the term “black hole” simply refers to the highly efficient “capture” of the electromagnetic energy incident on the device, and does not imply any profound analogy to General Relativity.
SUMMARY
[0006] Disclosed herein is an approach to highly efficient electromagnetic energy absorption, based on the materials having particular spatial dependencies of the permittivity. The term “absorption” may be understood in this context to describe a situation where the electromagnetic energy enters a structure, and does not come out. The incident energy may, however, be converted to other energy forms; for example: to electrical energy by photodetectors, or to heat by an absorbing material located therein.
[0007] The system and method employs the control of the local electromagnetic response of the material of the structure, with a resulting “effective permittivity potential” that determines the dynamics of the wave propagation in the structure so as to form an effective “black hole.” That is, the electromagnetic energy goes in and does not come out, even if the structure itself were to be essentially lossless. In an ideal case, all of the energy is trapped in the interior, or is converted to another energy form. The device, in some configurations, exhibits efficient omnidirectional energy capture over a broad spectral bandwidth.
[0008] In an aspect, the system includes a material having a spatial variation of permittivity selected such the variation of the permittivity in a direction along the local radius of curvature of the system is at inversely proportional to at least the square of the local radius of curvature.
[0009] In another aspect, the system may comprise a plurality of contiguous thin shells each shell having a permittivity. The shells may be arranged about a center of curvature so that the variation of permittivity of the shells with a radial distance from a center of curvature is at least an inverse square radial function.
[0010] A central region of the structure may have a device such as a photodetector for converting the electromagnetic energy to an electrical signal, or an absorbing medium for converting the electromagnetic energy to heat.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 shows (A) cut-out views of the spherical and (B) cylindrical optical “black holes.” The core represents the “payload” of the device (e.g., a detector, a photovoltaic element, or the like);
[0012] FIG. 2 shows ray trajectories in systems with the permittivity defined by Eq. 7 for (A) n=−1, (B) n=1, (C) n=2, and (D) n=3; the core radius is assumed to be infinitesimal;
[0013] FIG. 3 shows a Gaussian beam incident on the “black hole” (A) off-center and (B) on-center. Note the lack of any visible reflection which would be manifested by the interference fringes between incident and reflected light. The solid black lines in (A) show the classical ray trajectories. The “black hole” is formed by n-doped silicon-silica glass composite with the inner radius of 8.4 μm and the outer radius of R=20 μm. The free-space incident light wavelength is λ=1.5 μm;
[0014] FIG. 4 . shows the schematic geometry of a layered structure;
[0015] FIG. 5 . Illustrates the effect of an Ideal black hole with ∈ s =2.1, ∈ c =12, γ c =0.7, r s =20 μm, and r c =r s (∈ s /∈ c ) 1/2 =8.367 μm on an incident Gaussian beam with free-space wavelength λ=1.5 μm and full width w=2λ is focused at x 0 =0, and (A) y 0 =1.5r s ; (B) y 0 =r s ; (C) y 0 =0.75r s , and (D) γ 0 =0;
[0016] FIG. 6 shows simulated electromagnetic field maps for a lamellar “black hole” optical concentrator and absorber (∈ s =2.1, r s =20 μm, and r c =8.367 μm) as a function of the total number of layers, l. The device is illuminated by a plane wave with free-space wavelength A=1.5 μm. (A) I=3, and 72% absorption efficiency, (B) I=5, and 84% absorption efficiency, (C) I=9, and 90% absorption efficiency, (D) I=17, and 94% absorption efficiency; and (E) is the reference case of the ideal black hole with smooth gradient, and 99% absorption efficiency;
[0017] FIG. 7 shows simulated electromagnetic field maps of the black hole device (∈ s =2.1, r s =20 μm, and r c =8.367 μm) illuminated by a TE-polarized plane wave with a free-space wavelength of (A) 1.5 μm, (B) 3.0 μm, (C) 4.5 μm, and (D) 6.0 μm;
[0018] FIG. 8 shows (A) the absorption efficiency Q a vs. the ratio λ/r s obtained for the TE- and TM-polarized plane wave; and, (B) a more detailed plot for the ratios from 0.075 to 0.15; and,
[0019] FIG. 9 shows an example of a planar solar panel having a plurality of solar cells with a black hole structure interposed between the solar cell and the energy source.
DESCRIPTION
[0020] Exemplary embodiments may be better understood with reference to the drawings, but these embodiments are not intended to be of a limiting nature.
[0021] To achieve substantially equal performance at any incidence angle direction, a spherically symmetric shell, for example, may be used, as shown in FIG. 1A . The shell 5 may have an outer radius R s , 6 , and an inner radius R c , 7 , with the radial variation in the shell permittivity ∈(r) matching those of the outer medium 9 and of the internal core 10 at the corresponding interfaces
[0000]
ɛ
=
{
ɛ
c
+
i
γ
,
r
<
R
c
,
ɛ
(
r
)
,
R
c
<
r
<
R
,
ɛ
0
,
r
>
R
,
(
1
)
[0000] where the core radius R c =√{square root over (∈ 0 /∈ c )}. Alternatively, cylindrical geometry 11 may be used and this is also easy to exactly analyze formally (see FIG. 1B ). Other device shapes are possible and may be evaluated with numerical methods. A person of skill in the art will be able to formulate such cases and use commercially available software packages to design the structures and materials properties, after having been made aware of the teachings herein.
[0022] When the materials forming the shell are essentially non-magnetic, the refractive index is:
[0000] n =√{square root over (∈)}
[0023] The inner core 10 may represent the location of the “payload” of the device: e.g., a photovoltaic system for recovering the trapped light energy for solar power applications, or a photodetector, or absorbing (lossy) material, such as a highly doped semiconductor (e.g., silicon, germanium, gallium arsenide, or the like). Similarly, for applications where a waveguide propagation mode may be used, a cylindrical equivalent (see FIG. 1B ) may be considered.
[0024] A desired radial variation in the permittivity of a composite shell structure may be achieved by, for example, changing the relative volume fractions of the component materials. The structure may be fabricated using thin layers of differing material properties, or other known or to be developed techniques for making a structure with the specified spatial electromagnetic properties. That is, it is the spatial variation of the characterizable electromagnetic properties of the materials comprising the structure that determine the resultant optical performance. These characteristics may be obtained with a variety of materials, or metamaterials, depending on the operating wavelength, bandwidth of operation and other device attributes.
[0025] The permittivity may vary spatially depending on the topological structure of the structure which may be, for example, a composite structure, a layered or lamellar system, a fractal material mixture, or other arrangement. The permittivity may generally be a monotonic function and thus the desired variation in ∈(r) can be realized with a suitable radial dependence of the component densities. However this is not required.
[0026] Herein, it is convenient to use the relative permittivity where numerical examples are given. The relative permittivity is the ratio of the material permittivity to that of a vacuum. As this would be apparent to a person of skill in the art, the modifier “relative” is often omitted.
[0027] The specific materials used may depend on the wavelength of operation and the bandwidth of the device, and may be selected based on practical considerations of fabrication and cost, while conforming to the electromagnetic properties described herein. Where the electromagnetic properties of the materials are described, a person of skill in the art will understand that the materials themselves may be composite materials where selected materials having differing electromagnetic properties are combined on physical scales such that the measurable electromagnetic properties of the composite material are based on the sizes and shapes of the component materials and the electromagnetic properties of the individual components.
[0028] Often, the material properties may be predicted by using an effective medium model. Certainly, the properties may be measured using appropriate measurement techniques for bulk materials so as to characterize the material at a wavelength or a range of wavelengths. A useful broadband material is silicon, which has a low loss transmission window over the range 1<λ<10 μm, and again at longer wavelengths. Other materials which may be used at optical, near infrared and infrared wavelengths may be, for example, germanium, gallium arsenide, and silicon carbide.
[0029] Matching the permittivity of the system to a low-refractive-index environment such as air may require metallic components (with ∈ m <0) in the composite forming the outer portion of the structure, with the concomitant losses leading to a nonzero imaginary part of ∈(r). On the other hand, if the permittivity of the outer medium ∈ 0 >1, an all-dielectric design is possible. Typically the permittivity of the material at the outer boundary of the structure may be greater than unity, and conventional impedance matching layers (e.g., thin films) may be used for impedance matching to the external environment as is the case for conventional optical lenses and other electromagnetic structures.
[0030] To incorporate the application-dependent inner core, such as a photodetector, the dimensions of the structure may significantly exceed the light wavelength
[0000] R c ≧λ,R>>λ (2)
[0000] The size of a structure may be substantial, and be capable of enclosing conventional optical, electrical or other components.
[0031] In this scale size regime, semiclassical electromagnetic analysis may be used and leads to a clear physical picture of the wave dynamics and an accurate quantitative estimation of the performance. An exact is analysis presented subsequently.
[0032] For spherically and cylindrically symmetric distributions of the permittivity ∈(r), the effective Hamiltonian describing the electromagnetic wave propagation is:
[0000]
H
=
P
r
2
2
ɛ
(
r
)
+
m
2
2
ɛ
(
r
)
r
2
,
(
3
)
[0000] where P r is the radial momentum and m is the total angular momentum for a spherical system, or the projection thereof on a cylinder axis for the cylindrical version. The form of the classical equations of motion corresponding to the Hamiltonian outside the core, r>R c , are the same as those of a point particle of unitary mass in a central potential field:
[0000]
V
eff
(
r
)
=
1
2
(
ω
c
)
2
[
ɛ
0
-
ɛ
(
r
)
]
,
(
4
)
[0000] where c is the speed of light in a vacuum and ω is the radian frequency.
[0033] For a radial permittivity profile described by e(r)∝1/r, the properties may be considered as an optical analog to the Kepler problem in celestial mechanics. A solution of the Hamiltonian equations yields the optical ray trajectories in polar coordinates
[0000]
Φ
(
r
)
=
Φ
0
+
∫
m
/
r
1
m
/
r
ξ
C
0
ɛ
(
m
ξ
)
-
ξ
2
,
(
5
)
[0000] where the constants r 1 , φ 0 and C 0 are set by the initial conditions of the incident light ray on the external surface.
[0034] When the effective potential V eff ∝∈ 0 −∈ is sufficiently i “attractive,” the corresponding ray trajectories experience a fall onto the core of the system. Representing the permittivity as:
[0000] ∈( r )=∈ 0 (1+Δ∈) (6)
[0000] where Δ∈ may be represented by a power law variation, Δ∈˜1/r n , any value of n≧2 leads to such a “fall” Into the core region. That is, the variation of the permittivity with radius is at least as great as an inverse square function of the radial distance.
[0035] Thus, an example of a family of optical “black holes” may be characterized by having a variation of permeability given by (6) with:
[0000]
Δɛ
n
(
r
)
=
{
0
,
r
>
R
,
(
R
r
)
n
,
r
<
R
,
(
7
)
[0000] For this class of permeability variation for the ray trajectories within the “event horizon,” r≦R, one obtains the result:
[0000]
r
(
φ
)
=
R
{
[
cos
(
n
-
2
2
(
φ
-
φ
0
)
)
cos
(
n
-
2
2
(
φ
R
-
φ
0
)
)
]
2
n
-
2
,
n
≠
2
exp
[
-
mR
n
C
0
-
1
(
φ
-
φ
0
)
]
,
n
=
2
(
8
)
[0000] where φ R is an arbitrary constant, determined from the initial conditions of a particular trajectory.
[0036] Representative trajectories corresponding to different orders n are shown in FIG. 2 . Higher order variations of the radial permeability are also possible. For purposes of analysis and understanding, examples are shown which use the smallest order of the variation which captures the incident rays: n=2.
[0037] In an example where the materials and fabrication method chosen results in permittivity values in the range ∈ 0 <∈<∈ c , the black hole may be expressed as:
[0000]
ɛ
(
r
)
=
{
ɛ
0
,
r
>
R
.
ɛ
0
(
R
r
)
2
,
R
c
<
r
<
R
,
ɛ
c
+
i
γ
,
r
<
R
c
.
(
9
)
[0000] where the core radius R c is:
[0000]
R
c
=
R
ɛ
0
ɛ
c
,
(
10
)
[0038] FIG. 3 shows a full wave numerical calculation (using COMSOL Multiphysics, from COMSOL, Burlington, Mass.)) of the light guidance in a shell structure according to (9) and (10) with a permittivity varying from an outer boundary layer 6 of ∈ 0 =2.1 (which may represent silica glass) to a value at the core radius 7 of ∈ c +iγ=12+0.7i (which may represent n-doped silicon with the doping density n≈2.7·10 20 cm −3 ). The shell structure may be formed by such a glass glass-silicon composite material with an outer radius R≈20 μm and a core radius R c ≈8.4 μm.
[0039] The materials used may be metamaterials or other composite materials, or layers of conventional materials, or a combination thereof. Such materials may be, for example, concentric shells of materials having differing electromagnetic properties, or where the properties vary in a smooth or stepwise manner with radial distance. The scale size of the material variation may be greater than that of metamaterials for the shell thickness, for example, and the material properties may be homogeneous over a scale size greater than a wavelength. In the example of FIG. 3 , the free-space wavelength of the incident radiation is λ=1.5 μm.
[0040] There is excellent agreement between an exact calculation and the result from using a semiclassical theory. As such, the use of ray tracing and other approximations in designing structures may be appropriate. The shape of the structure may differ from that of a sphere or cylinder and the effect of such other shapes may be understood by numerical analysis. Moreover, the material electromagnetic properties and the spatial variation thereof need only generally approximate the theoretical results. The use of spheres and cylinders has been for computational convenience and not intended to be a limitation.
[0041] So as to provide further insight into the concepts, the same structures are evaluated by a direct solution of Maxwell's equations.
[0042] Consider the cylindrical version of the device, assuming that the system is infinite in the “axial” direction z (see FIG. 1B ). When used to design a structure this would correspond to either (i) the length of the cylinder, d R λ, or (ii) the cylinder inside a single-mode waveguide system, where one may use the effective values of the permittivity, taking into account the waveguide mode structure. In this example, the TE and TM polarizations are decoupled and can be independently treated with nearly identical steps, so we will limit our analysis to the TE mode where the electric field E={circumflex over (z)}E. Using the polar coordinates (r,φ) we introduce the “wavefunction” ψ
[0000]
E
(
r
,
t
)
=
(
0
,
0
,
1
r
ψ
(
r
)
)
exp
(
m
φ
-
ω
t
)
(
11
)
[0000] For R c <r<R the wave equation reduces to
[0000]
ψ
″
+
(
k
0
R
)
2
-
m
2
+
1
/
4
r
2
ψ
=
0
(
12
)
[0000] where the wavenumber k i =√{square root over (∈ 0 ω/c)}. Equation 12 allows an analytical solution:
[0000]
ψ
(
r
)
=
A
r
cos
(
(
k
0
R
)
2
-
m
2
log
r
R
)
+
B
r
sin
(
(
k
0
R
c
)
2
-
m
2
log
r
R
c
)
(
13
)
[0000] where A and B are constants defined by the boundary conditions at the “inner” (r=R c ) and “outer” (r=R) interfaces of the shell. In the core and outer regions where the permittivity is constant, the solutions of the wave equations reduce to the standard Bessel (J m ) and Hankel (H m ± ≡J m ±iY m ) functions
[0000] E ( r,Φ,t )=exp( imΦ−iωt )
[0000]
x
{
CJ
m
(
ɛ
c
+
i
c
ω
r
)
,
r
<
R
c
,
H
m
-
(
k
0
r
)
+
r
m
H
m
+
(
k
0
r
)
,
r
>
R
.
(
14
)
[0000] where C is a constant and r m is the reflection coefficient for the angular momentum m. Note that only the Bessel function J m is present in the core region as Y m and H m diverge at the origin.
[0043] For the TE polarization that we consider, the boundary conditions for the electromagnetic field reduce to the continuity of E(r,φ) and the normal derivative thereof. Solving the resulting system of linear equations on A, B, C, and r m for the reflection coefficient:
[0000]
r
m
=
-
H
m
-
′
(
k
0
R
)
+
η
m
H
m
-
(
k
0
R
)
H
m
+
′
(
k
0
R
)
+
η
m
H
m
+
(
k
0
R
)
where
(
15
)
η
m
=
-
(
k
0
R
)
2
-
m
2
k
0
R
tan
[
(
k
0
R
)
2
-
m
2
log
R
R
c
-
arctan
(
pk
0
R
(
k
0
R
)
2
-
m
2
)
J
m
′
(
pk
0
R
)
J
m
(
pk
0
R
)
]
where
p
=
(
ɛ
c
+
i
γ
)
/
ɛ
0
.
(
16
)
[0044] For a given reflection coefficient in the angular momentum representation, the absorption cross section per unit length of a long cylinder is:
[0000]
σ
a
=
1
k
0
∑
m
1
-
r
m
2
2
(
17
)
[0000] Substituting (15) and (16) into (17), in the limit k 0 1, one obtains
[0000]
σ
a
=
2
R
[
1
-
2
F
(
k
0
R
γ
ɛ
c
)
+
F
(
2
k
0
R
γ
ɛ
c
)
]
,
where
F
(
x
)
=
∫
0
π
/
2
θ
cos
θ
exp
(
-
x
cos
θ
)
=
{
1
-
x
2
+
(
x
2
)
,
x
1
,
1
x
2
+
(
1
x
4
)
,
x
1.
(
18
)
[0045] In the absence of losses (18) yields zero absorption cross-section, while for k 0 Rγ 1, σ a is close to the full geometrical cross-section per unit length of the cylinder, 2R. Thus, as previously predicted by the semiclassical theory, the device does indeed capture all electromagnetic energy incident thereon from every direction. Furthermore, the effect is essentially nonresonant, leading to nearly perfect capture for an wide range of incident wavelengths, as long as the size of the structure is substantially larger than the free-space wavelength λ 0 , and:
[0000]
σ
a
=
2
R
[
1
-
7
4
(
ɛ
c
k
0
R
γ
)
2
]
,
R
γ
≥
λ
0
.
(
19
)
[0046] Thus, the structures are suitable for the capture (concentration) and absorption of electromagnetic energy (where absorption includes the transformation of the electromagnetic energy to an electrical signal or other energy form such as thermal) with nearly 100% efficiency. Such devices can find multiple applications in photovoltaics, solar energy harvesting, optoelectronics, omnidirectional sensors, and other applications where efficient collection or management of electromagnetic energy flows is desired.
[0047] Practical realizations of spherical or cylindrical optical and optoelectronic devices, or devices having more complex geometries, often involve a design that includes a number of layers. This is for convenience in fabrication, or to take advantage of specific material properties to achieve the desired spatial electromagnetic properties. Outer layers may be incorporated as a protective covering or for impedance matching, while an internal layer between the absorber (detector) and the inner shell surface of the optical concentrator may provide mechanical support as well as possible impedance matching. In a cylindrical configuration, a liquid may flow in the central core so as to absorb the incident energy and transfer the energy to other portions of a system through the ends of finite-length cylinders.
[0048] In an example, a concentric cylindrical device having l−1 layers, r i <r<r i+1 , i= 1,l−1 , with the “outer” (r>r s ) layer l is embedded in a host media, as shown in FIG. 4 . That is, the permittivity of the outside medium is equal to that of the outermost layer of the shell. In this manner, reflections at the outer boundary are suppressed. In some embodiments, reflections at this interface are suppressed by an anti-reflection layer or coating.
[0049] In an aspect, a simple (n=2) electromagnetic black hole may be a three-layered system with a radial gradient-index shell and an absorbing core, where the incident radiation is orthogonal to the cylinder axis. FIG. 5 shows an example full-wave simulation of an ideal black hole with ∈ s =2.1, ∈ c =12, γ c =0.7, r s =20 μm and r c =r s (∈ s /∈ c ) 1/2 =8.367 μm. The structure is illuminated with a Gaussian beam (free-space wavelength λ=1.5 μm and full width w=2λ), which is focused at x 0 =0, and (a) y 0 =1.5r s ; (b) γ 0 =r s ; (c) y 0 =0.75r s , and (d) y 0 =0.
[0050] The formalism of a layered system can also be used to study a non-ideal lamellar “black hole” optical concentrator and absorber, which approximates the ideal device (∈ s =2.1, r s =20 μm, and r c =8.367 μm) with a plurality of individually homogeneous layers. This example is presented to enable a person of skill in the art to make an initial choice of the number of layers that may be suitable for a particular application. Non-uniform thicknesses, variation of properties within a layer, and the like, will suggest themselves in particular applications, or for convenience in fabrication.
[0051] The device is illuminated by a plane wave with free-space wavelength λ=1.5 μm; for a system with 3, 5, 9, or 17 layers. The computed scattering and absorption efficiencies are 72%, 84%, 90%, and 94%, respectively, as shown in FIG. 6 A-D. FIG. 6E depicts the field map of the ideal black hole with smooth gradient, where 99% absorption efficiency is achieved.
[0052] To further illustrate the concept, FIG. 7 qualitatively portrays the effects on performance as one moves further away from the semiclassical limit. FIG. 7 shows field patterns of the device characterized by (∈ s =2.1, r s =20 μm, r c =8.367 μm) and illuminated by a TE-polarized plane wave having free-space wavelengths between 1.5 and 6.0 μm, where increasing scattering is observed with increase of wavelength.
[0053] A quantitative comparison of the absorption efficiency, Q abs , versus the ratio λ/r s is shown in FIG. 8A , and is separately calculated for the TE- and TM-polarized plane wave using the exact method described above, and for the and the semiclassical result, which is valid for both polarizations. FIG. 8A indicates the good quality of the semiclassical approximation of the absorption cross-section even far beyond the semiclassical limit. FIG. 8B shows a more detailed plot for λ/r s between 0.075 and 0.15.
[0054] The ability to accept electromagnetic energy over a wide range of incidence angles and over a broad spectrum of wavelengths may improve the performance of a variety of systems such as solar power generation, visible and infrared sensors, and the like.
[0055] Solar cells are often planar devices, which may be overlaid with roughened surfaces, whiskered surfaces or microlenses so as to improve the coupling of the incident radiation to the photovoltaic cells. Even so, the effectiveness of most solar cells falls of markedly when the radiation is not normally incident on the surface thereof. This is in addition to the cosine effect of energy density. Fixed orientation solar cells may therefore be inefficient except for a small portion of the day. Solar cells that are mechanically orientated to face the sun require expensive mounts and maintenance. However, as shown in FIG. 9 , a plurality of solar cells 20 , overlaid by hemispherical or half-cylindrical “black hole” structure 30 would collect electromagnetic energy over a large range of incidence angles. That is, the solar energy 50 would enter the black hole and be directed onto the solar cells, which may be mounted to a substrate 40 .
[0056] By concentrating the solar energy in this manner, the size of the solar cells can be reduced, while maintaining a capture area essentially equal to the planar extent of the array of black holes. In addition, solar energy that is scattered by clouds, reflected from the earth, and the like, and which is within the angular view of the array will likewise be directed to the solar cell. Not only does this mitigate the effects of scattering of the solar energy, but the total solar energy available is somewhat greater than that of the direct solar illumination itself.
[0057] In optical detectors using photodetectors, the background or “dark” noise is a function of the surface area of the detector. So, a concentrator that directs light from a wide range of angles onto a smaller area detector may improve the sensitivity of systems using photodetectors.
[0058] Some military systems are intended to detect the infrared radiation from hot bodies such as engines, and their exhausts, including jet and rocket exhausts. Often it is sufficient to detect the presence of the infrared emitter regardless of the angle of incidence of the radiation. So, for example, a spherical or hemispherical black hole directing the incident radiation onto the photodetector may increase the field-of-view of the detector, as well as the sensitivity of the system.
[0059] The example applications are not intended to be limiting as it will be apparent to a person of skill in the art that a variety of uses are possible. The black holes may be used singly, or arrayed as a plurality of black holes, and may be formed on a surface, where the surfaces may themselves be curved. In this context, a black hole may be a section of a simple structure which may be spherical or cylindrical; other shapes and variations may be designed, and such shapes may be chosen so as to facilitate the manufacture or deployment of the devices.
[0060] The structures may be entirely formed of solid materials, however, liquids, gels, and other materials may be used as material components thereof in order to take advantage of the material properties.
[0061] It is therefore intended that the foregoing detailed description be regarded as illustrative rather than limiting, and that it be understood that it is the following claims, including all equivalents, that are intended to define the spirit and scope of this invention.
|
An electromagnetic black hole may be fabricated as concentric shells having a permittivity whose variation is at least as great as an inverse square dependence on the radius of the structure. Such a structure concentrates electromagnetic energy incident thereon over a broad range of angles to an operational region near the center of curvature of the structure. Devices or materials may be placed in the operational region so as to convert the electromagnetic energy to electrical signals or to heat. Applications included solar energy harvesting and heat signature detectors.
| 7
|
FIELD OF THE INVENTION
[0001] The invention relates to building structures, and more particularly to trim members for protecting, covering and decorating the area from the base of the roof to the upper portion of the outer well of a building structure, such as a home or office or other commercial building, where the trim members are manufactured by pultrusion.
BACKGROUND OF THE INVENTION
[0002] In the United States, most residential or light weight-building systems employ wood or metal rafters, which extend from six to twenty-four inches beyond the outer wall. The outer wall is typically constructed of masonry or wood construction. Typically, the rafters and the sub-fascia (a member that connects the rafter ends together) support roof decking which forms the base of the roof. Shingles or other roofing materials cover the roof decking. Typically, the entire area from the lower edge of the roof decking to the upper portion of the outer wall of the building structure is covered with a cornice assembly, usually made of wood or wood covered with aluminum or vinyl. Aluminum or vinyl is a preferred material because of the high maintenance of wood trim pieces, which require repainting every few years (but in fact, vinyl cannot be painted at all). A fascia, usually the upper trim member of the cornice assembly, typically covers the sub-fascia or the outer portion of the rafter ends. This fascia protects the sub-fascia or rafter ends from the elements, and provides a decorative cover. The soffit, another trim member of the cornice, typically extends horizontally between the bottom inside edge of the fascia to the upper portion of the outer wall. The third trim member of the cornice assembly, known as the frieze, is a decorative member that starts at the soffit and runs down the outside surface of the top of the outer wall. The frieze is usually made of the same material as the fascia and soffit.
[0003] One problem associated with decorative and protective cornice assemblies is the labor required to install the several component parts, such as the fascia, the soffit, the frieze, and decorative moldings associated therewith. A second problem occurs when wood is used, which may not and which requires regular repainting. A third problem is denting of aluminum products, and a fourth problem is expanding and contracting of aluminum and vinyl. Numerous fastening means, such as nails, staples, and the like must be used to attach the component parts together and/or to the building. This practice adds significant time and expense to the construction of a conventional building structure.
[0004] In addition, a problem associated with aluminum or vinyl cornice assemblies is the shearing of the fasteners used to fasten the cornice assembly or the enlarging of the holes created for fastening the assembly to the building structure. This shearing/enlarging problem is due to the relatively large amount of expansion and contraction due to temperature or moisture variations, which also causes buckling of the aluminum or vinyl material. As a result, the cornice assembly may become detached from the building structure or may appear warped.
[0005] In the past, a cornice assembly has had to be fabricated in place. Each portion of the cornice assembly is attached to the building individually. When a wood backing is used in conjunction with vinyl or aluminum assembly, yet another aspect of the assembly must be attached individually. This process is time-consuming, labor-intensive, and difficult to attain professional looking results.
[0006] A known method of manufacturing articles which have a lineal profile and a constant cross-section is called pultrusion. Pultrusion is the opposite of extrusion. It is a continuous pulling process in which rovings or strands of fibers are impregnated with resin and are then pulled through a heated die which cures the resin while also providing the cross-sectional shape to the piece. The cured piece is cut to length as it comes off the line. See, for example, “Pultrusion for Engineers” (Trevor F. Starr ed., CRC Press, 2000), which is hereby incorporated by reference. Pultruded material can be colored during manufacture, but unlike vinyl, also has surface that can accept and permanently retain paint.
[0007] Therefore, pultrusion is desirable to provide an improved method for the manufacture of the cornice assembly (or other trim members used in home construction), to protect the interface between the roof decking and the upper portion of the outer wall of a building structure. Pultrusion would provide a cornice assembly that minimizes structural instability by eliminating expansion and contraction of the cornice assembly and minimizes the use of fasteners while providing a less labor-intensive fabrication process. In addition, a pultruded cornice assembly is desirable to reduce production and labor costs, including the elimination of the need to paint the trim after assembly—although painting remains an option if color change is desired.
SUMMARY INVENTION
[0008] The present invention includes improved methods for fabricating cornice assemblies and other trim members used in house construction. The cornice assemblies and trim members are fabricated through a process of pultrusion. Improved cornice assemblies are disclosed, which include at least a fascia, a soffit and a frieze with crown molding, all of which may be integrated into a unitary structure. The improved cornice assemblies may be constructed from one, two or more trim members. Also disclosed is a method of trimming a building structure using the cornice assemblies and trim members made by pultrusion. The dies utilized in the pultrusion of the cornice assemblies and trim members are also disclosed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a cross-section of a cornice assembly made of a unitary construction which includes a facia, a soffit, a crown, a frieze and a gutter.
[0010] FIG. 2 is a cross-section of a cornice assembly made of two trim members.
[0011] FIG. 3 is a pultrusion die with a channel for a unitary construction cornice assembly with a facia, a soffit, a crown, a frieze and a gutter.
[0012] FIG. 4 is a pultrusion die for a trim member including a soffit and a crown.
[0013] FIG. 5 is a pultrusion die for a trim member including a facia and a gutter.
[0014] FIG. 6 is a pultrusion die for a trim member including a frieze.
[0015] FIG. 7 is a cross-section of a cornice assembly made of three trim members.
[0016] FIG. 8 is a cross-section of a cornice assembly made of two trim members.
[0017] FIG. 9 is a cross-section of a trim member including a facia, a soffit and a gutter and a longitudinal section of the soffit including an area of vent holes.
[0018] FIG. 10 is a cross-section of a trim member including a facia and a soffit without gutter.
[0019] FIG. 11 is a cross-section of a trim member including a crown and a frieze where the frieze includes a slotted opening to receive wood, metal or vinyl siding.
[0020] FIG. 12 is a cross-section of a trim member including a crown and a frieze where the frieze includes a slotted opening to receive brick veneer.
[0021] FIG. 13A is a cross-section of an outside edge can trim member.
[0022] FIG. 13B is a cross section of an inside edge cap.
[0023] FIG. 14 is a cross-section of a belt board trim member.
[0024] FIG. 15 is a cross-section of a rake trim member.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0025] Referring now to FIG. 1 , a cornice assembly 10 according to the invention is shown. The cornice assembly 10 includes portions a facia 12 , a soffit 14 , a crown 16 , and a frieze 18 . Optionally, the cornice assembly may also include a gutter 20 in which case the facia 12 forms the back side of the gutter 20 .
[0026] A significant advantage may be gained through a unitary construction (formed as one piece) of the cornice assembly 10 in terms of the amount of labor needed to install the cornice assembly 10 . With a unitary construction, effort need only be spent on attaching the cornice assembly 10 to the building structure, while effort spent on fabricating the cornice assembly 10 is completely eliminated.
[0027] The cornice assembly 10 may be used in with walls made of any suitable outer sheathing building material known in the art, such as plywood, fiber board, celotex, OSB (oriented strand board) and the like.
[0028] In a second embodiment, as best seen in FIG. 2 , the cornice assembly 22 may be made of two or more trim members which are connected together to form the overall cornice assembly 22 . For example, one trim member may comprise the gutter 20 , the facia 12 and the soffit 14 , while another trim member includes the crown 16 and the frieze 18 . In this embodiment, the trim members are preferably constructed such that they may be press fit together. However, any suitable means of connecting the trim members to form the cornice assembly 22 may be used, including adhesives, bolts, nails or screws. By using press fit connections, the effort of fabricating the cornice assembly 22 on the job site is reduced as compared to traditional cornice assemblies. First, trim members capable of being press fit can be connected without the use of tools. Second, because press fitting connections are separate from the means for attaching the cornice assembly 22 to the building structure, the cornice assembly 22 can be fabricated at ground level as opposed to during attachment to the building structure. This saves both on the effort needed to fabricate the cornice assembly 22 and to attach the cornice assembly 22 to the building structure.
[0029] The cornice assemblies and trim members of the present invention are preferably manufactured through the process of pultrusion. Pultrusion is an economical technique which is especially suited for the manufacture of cornice assemblies and other trim members because they have uniform cross-sections and also benefit from the high strength to weight ratio provided by pultrusion.
[0030] Of importance to the pultrusion process is the die through which the resin impregnated reinforcements are pulled. Die include multiple metal blocks, which, when assembled, has a through-hole or channel in the shape of the desired cross-section of the trim member. FIG. 3 shows a die 24 with a channel 25 which would be used to manufacture an entire cornice assembly in a unitary construction. As can be seen, a total of ten different blocks 26 - 44 make up the die 24 for the unitary construction of the cornice assembly. The various blocks of the die 24 are held together with bolts, screws or other suitable fasteners 46 . FIG. 4 shows a die 48 which is used to manufacture a portion of a cornice assembly including a soffit 14 and a crown 16 . The soffit/crown trim member made with die 48 would be connected to a trim member including a gutter 20 and a facia 12 made with die 50 , shown in FIG. 5 , and to a trim member including a frieze 18 made with die 52 , shown in FIG. 6 . Together the trim members created by these die 48 , 50 and 52 would fit together to form a cornice assembly 54 , shown in FIG. 7 .
[0031] Selection of the particular resin and reinforcements that maybe used in the pultrusion of cornice assemblies and trim members are well within the design capability of those skilled in the art. Exemplary reinforcements include continuous strands of fiberglass, aramid fibers, and graphite. In addition, chopped strand, continuous strand or swirl mats may also be used as reinforcements. A useful reinforcement is glass fiber because it is economically priced as compared to other fibers, such as carbon fibers, and has a high strength to weight ratio. Exemplary resin include polyurethane, polyesters, vinyl esters, epoxy resins, acrylic and phenolic resins.
[0032] One or more stiffening ribs may be attached to the building structure side of the cornice assemblies and trim members. In FIG. 8 , stiffening rib 55 included in a two piece cornice assembly made of a trim member with a gutter 20 , a facia 12 and a soffit 14 and a trim member with a crown 16 and a frieze 18 . These stiffening ribs may be pultruded from the same die as the cornice assemblies or trim members. The stiffening ribs provide extra support for the cornice assemblies and trim members against forces applied there against. This bracing prevents damage which may result from the placement of ladders against the cornice assemblies and trim members, particularly placement of ladders at the frieze 18 . Furthermore, nailers 57 , 61 , which form a nailing surface for nailing the cornice assembly or trim member to the building structure.
[0033] The available cross-sections for trim members is unlimited. Exemplary cross-sections, in addition to the ones previously shown with regard to the die 48 - 52 , include a trim member 56 which includes a gutter 20 , a facia 12 and a soffit 14 shown in FIG. 9 , a trim member 58 which includes a facia 12 and a soffit 14 shown in FIG. 10 , a trim member 60 which includes a crown 16 and a frieze 18 (adapted for use with exterior sheet siding) shown in FIG. 11 . shown in FIG. 12 . The friezes shown in FIGS. 8 and 11 show a relatively narrow channel 63 for accepting exterior sheet siding (such as aluminum, vinyl, wood, or the like). The frieze shown in FIG. 12 has a relatively wide channel 65 designed to accept brick or stone veneering. The trim members 56 - 62 may be mixed and matched to achieve the desired cornice assembly.
[0034] Other trim members which may be pultruded include caps for covering vertical edges, as shown in FIG. 13A , which are used to cover an outside edge cap where two pieces of siding come together. Belt boards as shown in FIG. 14 , which are used to transition from one siding material 71 to another FIG. 13B shows an inside edge cap. One trim member which may be pultruded is a rake, which is used along the gable side of the intersection between the siding material 71 and the roof deck 73 , as seen in FIG. 15 .
[0035] One or more vent holes may be made in the soffit allow circulation of air and escape of moisture. These vent holes may be made shortly after the time of fabrication of the pultruded member or at the job site, as dictated by the needs of the installer. Vent holes 64 in the soffit 14 , are shown in a longitudinal view of the soffit portion 14 of trim member 56 in FIG. 9 .
[0036] Preferably, the method of attaching the trim members to each other are press fit connections 59 , as best seen in FIG. 11 , because such fasteners are easily constructed during the pultrusion process. However, because of the thermal stability of pultruded members, any fastening means may be used without concern about the expansion and contraction due to variations in temperature or moisture. Cornice assemblies and trim member manufactured via pultrusion expand and contract less than 1 / 26 th of that of steel over a given temperature range. Thus, fasteners will not be sheared by pultruded cornice assemblies and trim members.
[0037] Various fastening slots are needed in aluminum and vinyl siding trim members to facilitate expansion and contraction that occurs after installation around the fastening nail after installation. However, such fastening slots are not necessary with pultruded members because, as discussed above, the pultruded cornice assemblies and trim members of the present invention do not expand or contract due to changes in temperature or moisture. Thus, when fastening pultruded cornice assemblies to building structures, the step of having to form slots can be eliminated. Also, trim members made from aluminum or vinyl and more difficult to install than pultruded members because they cannot be firmly nailed to the sheathing but must be loosely nailed so that they literally “hang” from the mounting nails by way of the slots. Pultruded members can be nailed firm just like wood can be nailed to other wood.
[0038] Because the pultruded cornice assemblies and trim members of the present invention have superior rigidity and strength to weight ratios, a significantly fewer fasteners are needed to attach the cornice assemblies and trim members to building structures.
[0039] In combination with the pultruded cornice assemblies of the present invention and other trim members, a variety of butt joint caps, corner caps, and end caps may be used to complete the trimming of a building structure. Butt joint caps are used to bridge the area where two linear sections of a cornice assembly or trim member come together.
[0040] Corner caps are used to bridge the area where two linear section of a cornice assembly or trim members come together at a corner. Both inside and outside corners are needed. While not suitable for manufacturing by pultrusion, butt joint, end, and corner caps may cost effectively be manufactured by other conventional methods such as foam injection, plastic injection, urethane casting, and the like. Caps are preferably attached with two-sided tape.
[0041] End caps are used to close off the ends of cornice assemblies and trim members to prevent dirt and water from penetrating behind the cornice assembly and potentially damaging the building structure.
[0042] While the invention has been specifically described in connection with certain specific embodiments thereof, it is to be understood that this is by way of illustration and not of limitation, and the scope of the appended claims should be construed as broadly as the prior art will permit.
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The present invention is an improved method of making cornice assemblies and other trim members utilizing the process of pultrusion. The cornice assemblies and the other than members made by the method of the present invention exhibit superior strength to weight ratios, low expansion and contraction due to changes in temperature and humidity, as well being less labor intensive to install.
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[0001] This is a continuation of co-pending application Ser. No. 07/937,893, filed Dec. 22, 1992, which is US nationalization of PCT application PCT/US91/02650, filed Apr. 18, 1991, which PCT application is a continuation-in-part of application Ser. No. 07/615,715, filed Nov. 20, 1990, now U.S. Pat. No. 5,141,851, which is a continuation-in-part of application Ser. No. 07/510,706, filed Apr. 18, 1990, abandoned. The government may own certain rights in the present invention pursuant to NIH grant number 5-PO1-HL20948.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to the identification and characterization of an enzyme involved in expression of the cancer phenotype, as well as to the identification and selection of compounds for its inhibition. In particular aspects, the invention relates to farnesyl protein transferase enzymes which are involved in, among other things, the transfer of farnesyl groups to oncogenic ras protein.
[0004] 2. Description of the Related Art
[0005] In recent years, some progress has been made in the elucidation of cellular events lending to the development or progression of various types of cancers. A great amount of research has centered on identifying genes which are altered or mutated in cancer relative to normal cells. In fact, genetic research has led to the identification of a variety of gene families in which mutations can lead to the development of a wide variety of tumors. The ras gene family is a family of closely related genes that frequently contain mutations involved in many human tumors, including tumors of virtually every tumor group (see, e.g., ref. 1 for a review). In fact, altered ras genes are the most frequently identified oncogenes in human tumors (2).
[0006] The ras gene family comprises three genes, H-ras, Kras and N-ras, which encode similar proteins with molecular weights of about 21,000 (2). These proteins, often termed. P21 ras , comprise a family of GTP-binding and hydrolyzing proteins that regulate cell growth when bound to the inner surface of the plasma membrane (3,4).
[0007] Overproduction of P21 ras proteins or mutations that abolish their GTP-ase activity lead to uncontrolled cell division (5). However, the transforming activity of ras is dependent on the localization of the protein to membranes, a property thought to be conferred by the addition of farnesyl groups (3,6).
[0008] A precedent for the covalent isoprenylation of proteins had been established about a decade ago when peptide mating factors secreted by several fungi were shown to contain a farnesyl group attached in thioether linkage to the C-terminal cysteine (7-9). Subsequent studies with the mating a-factor from Saccharomyces cerevisiae and farnesylated proteins from animal cells have clarified the mechanism of farnesylation. In each of these proteins the farnesylated cysteine is initially the fourth residue from the C terminus (see refs. 3, 4 and 10). Immediately after translation, in a sequence of events whose order is not yet totally established, a farnesyl group is attached to this cysteine, the protein is cleaved on the C-terminal side of this residue, and the free COOH group of the cysteine is methylated (3, 10, 11, 12). All of these reactions are required for the secretion of active a-factor in Saccharomyces (4).
[0009] Most, if not all, of the known p21 ras proteins contain the cysteine prerequisite, which is processed by farnesylation, proteolysis and COOH-methylation, just as with the yeast mating factor (3, 4, 10, 11, 12). The farnesylated p21 ras binds loosely to the plasma membrane, from which most of it can be released with salt (3). After binding to the membrane, some P21 ras proteins are further modified by the addition of palmitate in thioester linkage to cysteines near the farnesylated C-terminal cysteine (3). Palmitylation renders the protein even more hydrophobic and anchors it more tightly to the plasma membrane.
[0010] However, although it appears to be clear that farnesylation is a key event in ras-related cancer development, prior to now, the nature of this event has remained obscure. Nothing has been known previously, for example, of the nature of the enzyme or enzymes which may be involved in ras tumorigenesis or required by the tumor cell to achieve farnesylation. If the mechanisms that underlie farnesylation of cancer-related proteins such as P 21 ras could be elucidated, then procedures and perhaps even pharmacologic agents could be developed in an attempt to control or inhibit expression of the oncogenic phenotype in a wide variety of cancers. It goes without saying that such discoveries would be of pioneering proportions in cancer therapy.
SUMMARY OF THE INVENTION
[0011] The present invention addresses one or more shortcomings in the prior art through the identification and characterization of an enzyme, termed farnesyl:protein transferase, involved in the oncogenic process through the transfer of farnesyl groups to various proteins, including oncogenic ras proteins. Further, the present invention provides novel compounds, including proteins and peptides, that are capable of inhibiting the farnesyl:protein transferase enzyme.
[0012] It is therefore an object of the present invention to provide ready means for obtaining farnesyl transferase enzymes from tissues of choice using techniques which are proposed to be generally applicable to all such farnesyl protein transferases.
[0013] It is an additional object of the invention to provide means for obtaining these enzymes in a relatively purified form, allowing their use in predictive assays for identifying compounds having the ability to reduce the activity of or inhibit the farnesyl transferase activity, particularly in the context of p 21 ras proteins.
[0014] It is a still further object of the invention to identify classes of compounds which demonstrate farnesyl transferase inhibiting activity, along with a potential application of these compounds in the treatment of cancer, particularly ras -related cancers.
[0015] Farnesyl:Protein Transferase Enzyme
[0016] Accordingly, in certain embodiments, the present invention relates to compositions which include a purified farnesyl protein transferase enzyme, characterized as follows:
[0017] a) capable of catalyzing the transfer of farnesyl to a protein or peptide having a farnesyl acceptor moiety;
[0018] b) capable of binding to an affinity chromatography medium comprised of TKCVIM coupled to a suitable matrix;
[0019] c) exhibiting a molecular weight of between about 70,000 and about 100,000 upon gel filtration chromatography; and
[0020] d) having a farnesyl transferase activity that is capable of being inhibited by one of the following peptides:
[0021] i) TKCVIM;
[0022] ii) CVIM; or
[0023] iii) KKSKTKCVIM.
[0024] As used herein, the phrase “capable of catalyzing the transfer of farnesol to a protein or peptide having a farnesyl acceptor moiety,” is intended to refer to the functional attributes of farnesyl transferase enzymes of the present invention, which catalyze the transfer of farnesol, typically in the form of all-trans farnesol, from all-trans farnesyl pyrophosphate to proteins which have a sequence recognized by the enzyme for attachment of the farnesyl moieties. Thus, the term “farnesyl acceptor moiety” is intended to refer to any sequence, typically a short amino acid recognition sequence, which is recognized by the enzyme and to which a farnesyl group will be attached by such an enzyme.
[0025] Farnesyl acceptor moieties have been characterized by others in various proteins as a four amino acid sequence found at the carboxy terminus of target proteins. This four amino acid sequence has been characterized as —C-A-A-X, wherein “C” is a cysteine residue, “A” refers to any aliphatic amino acid, and “X” refers to any amino acid. Of course, the term “aliphatic amino acid” is well-known in the art to mean any amino acid having an aliphatic side chain, such as, for example, leucine, isoleucine, alanine, methionine, valine, etc. While the most preferred aliphatic amino acids, for the purposes of the present invention include valine and isoleucine, it is believed that virtually any aliphatic amino acids in the designated position can be recognized within the farnesyl acceptor moiety. In addition, the enzyme has been shown to recognize a peptide containing a hydroxylated amino acid (serine) in place of an aliphatic amino acid (CSIM). Of course, principal examples of proteins or peptides having a farnesyl acceptor moiety, for the purposes of the present invention, will be the p21 ras proteins, including p21 H-ras p21 K-rasA , p21 rasB and p21 N-ra . Thus, in light of the present disclosure, a wide variety of peptidyl sequences having a farnesyl acceptor moiety will become apparent.
[0026] As outlined above, the inventors have discovered that the farnesyl transferase enzyme is capable of binding to an affinity chromatography medium comprised of the peptide TKCVIM, coupled to a suitable matrix. This feature of the farnesyl transferase enzyme was discovered by the present inventors in developing techniques for its isolation. Surprisingly, it has been found that the coupling of a peptide such as one which includes CVIM, as does TKCVIM, to a suitable chromatography matrix allows for the purification of the protein to a significant degree, presumably through interaction and binding of the enzyme to the peptidal sequence. A basis for this interaction could be posited as due to the apparent presence of a farnesyl acceptor moiety within this peptide.
[0027] The phrase “capable of binding to an affinity chromatography medium comprised of TKCVIM coupled to a suitable matrix,” is intended to refer to the ability of the protein to bind to such a medium under conditions as specified herein below. There will, of course, be conditions, such as when the pH is below 6.0, wherein the farnesyl transferase enzyme will not bind effectively to such a matrix. However, through practice of the techniques disclosed herein, one will be enabled to achieve this important objective.
[0028] There are numerous chromatography matrixes which are known in the art that can be applied to the practice of this invention. The inventors prefer to use activated CH-Sepharose 4B, to which peptides such as TKCVIM, or which incorporate the CVIM structure, can be readily attached and washed with little difficulty. However, the present invention is by no means limited to the use of CH-Sepharose 4B, and includes within its intended scope the use of any suitable matrix for performing affinity chromatography known in the art. Examples include solid matrices with covalently bound linkers, and the like, as well as matrices that contain covalently associated avidin, which can be used to bind peptides that contain biotin.
[0029] Farnesyl transferase enzymes of the present invention have typically been found to exhibit a molecular weight of between about 70,000 and about 100,000 upon gel filtration chromatography. For comparison purposes, this molecular weight was identified for farnesyl protein transferase through the use of a Superose 12 column, using a column size, sample load and parameters as described herein below.
[0030] It is quite possible, depending on the conditions employed, that different chromatographic techniques may demonstrate a farnesyl transferase protein that has an apparent molecular weight somewhat different than that identified using the preferred techniques set forth in the examples. It is intended therefore, that the molecular weight determination and range identified for farnesyl transferase in the examples which follow, are designated only with respect to the precise techniques disclosed herein.
[0031] It has been determined that the farnesyl:protein transferase can be characterized as including two subunits, each having a molecular weight of about 45 to 50 kDa, as estimated by SDS polyacrylamide gel electrophoresis (PAGE). These subunits have been designated as α and β, with the α subunit migrating slightly higher than the β subunit, which suggests that the α subunit may be slightly larger. It has also been found that the α and β subunits have different amino acid sequences as determined by sequence analysis of tryptic digests prepared from the two purified proteins, and appear to be produced by separate genes. The peptide sequences obtained from the two proteins from rat brain are as follows:
TABLE I Farnesyl: Protein Transferase Peptide Sequences α subunit: 1) RAEWADIDPVPQNDGPSPVVQIIYS SEQ ID NO:1 2) DAIELNAANYTVWHFR SEQ ID NO:2 3) NYQVWHHR SEQ ID NO:3 4) HFVISNTTGYSD SEQ ID NO:4 5) VLVEWLK SEQ ID NO:5 6) LVPHNESAWNYLK SEQ ID NO:6 α subunit: 7) AYCAASVASLTNIITPDLFE SEQ ID NO:7 8) LQYLSIAQ SEQ ID NO:8 9) LLQWVTS SEQ ID NO:9 10) IQATTHFLQKPVPGFEEC ? EDAVT SEQ ID NO:10 11) IQEVFSSYK SEQ ID NO:11
[0032] The inventors have found that the holoenzyme forms a stable complex with ( 3 H]farnesyl pyrophosphate (FPP) that can be isolated by gel electrophoresis. The ( 3 H]FFP is not covalently bound to the enzyme, and is released unaltered when the enzyme is denatured. When incubated with an acceptor such as p21 H-ras , the complex transfers [ 3 H]farnesyl from the bound [ 3 H]FFP to the ras protein. Furthermore, crosslinking studies have shown that p21 H-ras binds to the β subunit, raising the possibility that the [3H]FFP binds to the a subunit. If this is the case, it would invoke a reaction mechanism in which the α subunit act as a prenyl pyrophosphate carrier that delivers FPP to p21 H-ras which is bound to the β subunit. Interestingly, the inventors have recently discovered that the at subunit is shared with another prenyltransferase, geranylgeranyltransferase, that attaches 20-carbon geranylgeranyl to ras-related proteins.
[0033] An additional property discovered for farnesyl transferase enzymes is that they can be inhibited by peptides or proteins, particularly short peptides, which include certain structural features, related in some degree to the farnesyl acceptor moiety discussed above. As used herein, the word “inhibited” refers to any degree of inhibition and is not limited for these purposes to only total inhibition. Thus, any degree of partial inhibition or relative reduction in farnesyl transferase activity is intended to be included within the scope of the term “inhibited.” Inhibition in this context includes the phenomenon by which a chemical constitutes an alternate substrate for the enzyme, and is therefore farnesylated in preference to the ras protein, as well as inhibition where the compound does not act as an alternate substrate for the enzyme.
[0034] Preparation of Farnesyl:Protein Transferase
[0035] The present invention is also concerned with particular techniques for the identification and isolation of farnesyl transferase enzymes. An important feature of the purification scheme disclosed herein involves the use of short peptide sequences which the inventors have discovered will bind the enzyme, allowing their attachment to chromatography matrices, such matrices may in turn, be used in connection with affinity chromatography to purify the enzyme to a relative degree. Thus, the present invention is concerned with a method of preparing a farnesyl transferase enzyme which includes the steps of:
[0036] (a) preparing a cellular extract which includes the enzyme;
[0037] (b) subjecting the extract to affinity chromatography on an affinity chromatography medium to bind the enzyme thereto, the medium comprised of a farnesyl transferase binding peptide coupled to a suitable matrix;
[0038] (c) washing the medium to remove impurities; and
[0039] (d) eluting the enzyme from the washed medium.
[0040] Thus, the first step of the purification protocol involves simply preparing a cellular extract which includes the enzyme. The inventors have discovered that the enzyme is soluble in buffers such as low-salt buffers, and it is proposed that virtually any buffer of this type can be employed for initial extraction of the protein from a tissue of choice. The inventors prefer a 50 mM Tris-chloride, pH 7.5, buffer which includes divalent chelator (e.g., 1 mM EDTA, 1 mM EGTA), as well as protease inhibitors such as PMSF and/or leupeptin. Of course, those of skill in the art will recognize that a variety of other types of tissue extractants may be employed where desired, so long as the enzyme is extractable in such a buffer and its subsequent activity is not adversely affected to a significant degree.
[0041] The type of tissue from which one will seek to obtain the farnesyl transferase enzyme is not believed to be of crucial importance. It is, in fact, believed that farnesyl transferase enzyme is a component or virtually all living cells. Therefore, the tissue of choice will typically be that which is most readily available to the practitioner. In that farnesyl transferase action appears to proceed similarly in most systems studied, including, yeast, cultured hamster cells and rat brain, it is believed that this enzyme will exhibit similar qualities, regardless of its source of isolation.
[0042] In preferred embodiments, the inventors have isolated the enzyme from rat brains in that this source is readily available. However, numerous other sources are contemplated to be directly applicable for isolation of the enzyme, including liver, yeast, reticulocytes, and even human placenta. Those of skill in the art, in light of the present disclosure, should appreciate that the techniques disclosed herein will be generally applicable to all such farnesyl transferases.
[0043] After the cell extract is prepared the enzyme is preferably subjected to two partial purification steps prior to affinity chromatography. These steps comprise preliminary treatment with 30% saturated ammonium sulfate which removes certain contaminants by precipitation. This is followed by treatment with 50% saturated ammonium sulfate, which precipitates the farnesyl transferase. The pelleted enzyme is then dissolved, preferably in a solution of 20 mM Tris-chloride (pH 7.5) containing 1 mM DTT and 20 μM ZnCl 2 . After dialysis against the same buffer the enzyme solution is applied to an ion exchange column containing an ion exchange resin such as Mono Q. After washing of the column, the enzyme is eluted with a gradient of 0.25-1.0 M NaCl in the same buffer. The enzyme activity in each fraction is assayed as described below, and the fractions containing active enzyme are pooled and applied to the affinity column described below.
[0044] It is, of course, recognized that the preliminary purification steps described above are preferred laboratory procedures that might readily be replaced with other procedures of equivalent effect such as ion exchange chromatography on other resins or gel filtration chromatography. Indeed, it is possible that these steps could even be omitted and the crude cell extract might be carried directly to affinity chromatography.
[0045] After the preliminary purification steps, the extract may be subjected to affinity chromatography on an affinity chromatography medium which includes a farnesyl transferase binding peptide coupled to a suitable matrix. Typically, preferred farnesyl transferase binding peptides will comprise a peptide of at least 4 amino acids in length and will include a carboxy terminal sequence of —C-A-A-X, wherein:
[0046] C=cysteine;
[0047] A=an aliphatic or hydroxy amino acid; and
[0048] X=any amino acid.
[0049] Preferred binding peptides of the present invention which fall within the above general formula include structures such as —C—V—I-M, —C—S—I-M and —C-A-I-M, all of which structures are found to naturally occur in proteins which are believed to be acted upon by farnesyl protein transferases in nature. Particularly preferred are relatively short peptides, such as on-the order of about 4 to 10 amino acids in length which incorporate one of the foregoing binding sequences. of particular preference is the peptide T-K—C—V—I-M which is routinely employed by the inventors in the isolation of farnesyl protein transferase.
[0050] The next step in the overall general purification scheme involves simply washing the medium to remove impurities. That is, after subjecting the extract to affinity chromatography on the affinity matrix, one will desire to wash the matrix in a manner that will remove the impurities while leaving the farnesyl transferase enzyme relatively intact on the medium. A variety of techniques are known in the art for washing matrices such as the one employed herein, and all such washing techniques are intended to be included within the scope of this invention. of course, for washing purposes, one will not desire to employ buffers that will release or otherwise alter or denature the enzyme. Thus, one will typically want to employ buffers which contain non-denaturing detergents such as octylglucoside buffers, but will want to avoid buffers containing, e.g., chaotropic reagents which serve to denature proteins, as well as buffers of low pH (e.g., less than 7), or of high ionic strength (e.g., greater than 1.0M), as these buffers tend to elute the bound enzyme from the affinity matrix.
[0051] After the matrix-bound enzyme has been sufficiently washed, for example in a medium-ionic strength buffer at essentially neutral pH the specifically bound material can be eluted from the column by using a similar buffer but of reduced pH (for example, a pH of between about 4 and 5.5). At this pH, the enzyme will typically be found to elute from the preferred affinity matrices disclosed in more detail hereinbelow.
[0052] While it is believed that advantages in accordance with the invention can be realized simply through affinity chromatography techniques, additional benefits will be achieved through the application of additional purification techniques, such as gel filtration techniques. For example, the inventors have discovered that Sephacryl S-200 high resolution gel columns can be employed with significant benefit in terms of protein purification. However, the present disclosure is by no means limited to the use of Sephacryl S-200, and it is believed that virtually any type of gel filtration arrangement can be employed with some degree of benefit. For example, one may wish to use techniques such as gel filtration, employing media such as Superose, Agarose, or even Sephadex.
[0053] Through the application of various of the foregoing approaches, the inventors have successfully achieved farnesyl transferase enzyme compositions of relatively high specific activity, measured in terms of ability to transfer farnesol from farnesyl pyrophosphate. For the purposes of the present invention, one unit of activity is defined as the amount of enzyme that transfers 1 pmol of farnesol from farnesyl pyrophosphate (FPP) into acid-precipitable p21 H-ras per hour under the conditions set forth in the Examples. Thus, in preferred embodiments the present invention is concerned with compositions of farnesyl transferase which include a specific activity of between about 5 and about 10 units/mg of protein. In more preferred embodiments, the present invention is concerned with compositions which exhibit a farnesyl transferase specific activity of between about 500 and about 600,000 units/mg of protein. Thus, in terms of the unit definition set forth above, the inventors have been able to achieve compositions having a specific activity of up to about 600,000 units/mg using techniques disclosed herein.
[0054] Of principal importance to the present invention is the discovery that proteins or peptides which incorporate a farnesyl acceptor sequence, such as one of the farnesyl acceptor sequences discussed above, function as inhibitors of farnesyl:protein transferase, and therefore may serve as a basis for anticancer therapy. In particular, it has been found that farnesyl acceptor peptides can successfully function both as false substrates that serve to inhibit the farnesylation of natural substrates such as p21 ras , and as direct inhibitors which are not themselves farnesylated. Compounds falling into the latter category are particularly important in that these compounds are “pure” inhibitors that are not consumed by the inhibition reaction and can continue to function as inhibitors. Both types of compounds constitute an extremely important aspect of the invention in that they provide a means for blocking farnesylation of p21 ras proteins, for example, in an affected cell system.
[0055] Inhibitors or Farnesyl:Protein Transferase
[0056] The farnesyl transferase inhibitor embodiments of the present invention concern in a broad sense a peptide or protein other than p21 ras proteins, lamin a or lamin b, or yeast mating factor a, which peptide or protein includes a farnesyl acceptor sequence within its structure and is further capable of inhibiting the farnesylation of p21 ras by farnesyl transferase.
[0057] In preferred embodiments, the farnesyl transferase inhibitor of the present invention will include a farnesyl acceptor or inhibitory amino acid sequence having the amino acids —C-A-A-X, wherein:
[0058] C=cysteine;
[0059] A=any aliphatic, aromatic or hydroxy amino acid; and
[0060] X=any amino acid.
[0061] Typically, the farnesyl acceptor or inhibitory amino acid sequence will be positioned at the carboxy terminus of the protein or peptide such that the cysteine residue is in the fourth position from the carboxy terminus.
[0062] In preferred embodiments, the inhibitor will be a relatively short peptide such as a peptide from about 4 to about 10 amino acids in length. To date, the most preferred inhibitor tested is a tetrapeptide which incorporates the —C-A-A-X recognition structure. It is possible that even shorter peptides will ultimately be preferred for practice of the invention in that the shorter the peptide, the greater the uptake by such peptide by biological systems, and the reduced likelihood that such a peptide will be destroyed or otherwise rendered biologically ineffective prior to effecting inhibition. However, numerous suitable inhibitory peptides have been prepared and tested by the present inventors, and shown to inhibit enzymatic activities virtually completely, at reasonable concentrations, e.g., between about 1 and 3 μM (with 50% inhibitions on the order of 0.1 to 0.5 μM).
[0063] While, broadly speaking, it is believed that compounds exhibiting an IC 50 of between about 0. 01 μM and 10 μM will have some utility as farnesyl transferase inhibitors, the more preferred compounds will exhibit an IC 50 of between 0.01 μM and 1 μM. The most preferred compounds will generally have an IC 50 of between about 0.01 μM and 0.3 μM.
[0064] Exemplary peptides which have been prepared, tested and shown to inhibit farnesyl transferase at an IC 50 of between 0.01 and 10 μM include CVIM; KKSKTKCVIM; TKCVIM; RASNRSCAIM; TQSPQNCSIM; CIIM; CVVM; CVLS; (SEQ ID NO: 12) CVLM; CAIM; CSIM; (SEQ ID NO: 13) CCVQ; (SEQ ID NO: 14) CIIC; (SEQ ID NO: 15) CIIS; (SEQ ID NO: 16) CVIS; (SEQ ID NO: 17) CVLS; (SEQ ID NO: 18) CVIA; (SEQ ID NO: 19) CVIL; (SEQ ID NO: 20) CLLL; (SEQ ID NO: 21) CLLL; (SEQ ID NO: 22) CTVA; (SEQ ID NO: 23) CVAM; (SEQ ID NO: 24) CKIM; (SEQ ID NO: 25) CLIM; (SEQ ID NO: 26) CVLM; (SEQ ID NO: 27) CFIM; (SEQ ID NO: 28) CVFM; (SEQ ID NO: 29) CVIF; (SEQ ID NO: 30) CEIM; (SEQ ID NO: 31) CGIM; (SEQ ID NO: 32) CPIM; (SEQ ID NO: 33) CVYM; (SEQ ID NO: 34) CVTM; (SEQ ID NO: 35) CVPM; (SEQ ID NO: 36) CVSM; (SEQ ID NO: 37) CVIF; (SEQ ID NO: 38) CVIV; (SEQ ID NO: 39) CVIP; (SEQ ID NO: 40) CVII.
[0065] A variety of peptides have been synthesized and tested such that now the inventors can point out peptide sequencing having particularly high inhibitory activity, i.e., wherein relatively lower concentrations of the peptides will exhibit an equivalent inhibitory activity (IC 50 ). Interestingly, it has been found that slight changes in the sequence of the acceptor site can result in loss of inhibitory activity. Thus, when TKCVIM is changed to TKVCIM, the inhibitory activity of the peptide is reversed. Similarly, when a glycine is substituted for one of the aliphatic amino acids in CAAX, a decrease in inhibitory activity is observed. However, it is proposed that as long as the general formula as discussed above is observed, one will achieve a structure that is inhibitory to farnesyl transferase.
[0066] A particularly important discovery is the finding that the incorporation of an aromatic residue such as phenylalanine, tyrosine or tryptophan into the third position of the CAAX sequence will result in a “pure” inhibitor. As used herein, a “pure” farnesyl:protein transferase inhibitor is intended to refer to one which does not in itself act as a substrate for farnesylation by the enzyme. This is particularly important in that the inhibitor is not consumed by the inhibition process, leaving the inhibitor to continue its inhibitory function unabated. Exemplary compounds which have been tested and found to act as pure inhibitors include (SEQ ID NO: 29) CVIF, (SEQ ID NO: 28) CVFM, and (SEQ ID NO: 33) CVYM. Pure inhibitors will therefore incorporate an inhibitory amino acid sequence rather than an acceptor sequence, with the inhibitory sequence characterized generally as having an aromatic moiety associated with the penultimate carboxy terminal amino acid, whether it be an aromatic amino acid or another amino acid which has been modified to incorporate an aromatic structure.
[0067] Importantly, the pure inhibitor CVFM is the best inhibitor identified to date by the inventors. It should be noted that the related peptide, (SEQ ID NO: 28) CFVM is not a “pure” inhibitor; its inhibitory activity is due to its action as a substrate for farnesylation.
[0068] The potency of CVFM peptides as inhibitors of the enzyme may be enhanced by attaching substituents such as fluoro, chloro or nitro derivatives to the phenyl ring. An example is parachlorophenylalanine, which has been tested and found to have “pure” inhibitory activity. It may also be possible to substitute more complex hydrophobic substances for the phenyl group of phenylalanine. These would include naphthyl ring systems.
[0069] The present inventors propose that additional improvements can be made in pharmaceutical embodiments of the inhibitor by including within their structure moieties which will improve their hydrophobicity, which it is proposed will improve the uptake of peptidyl structures by cells. Thus, in certain embodiments, it is proposed to add fatty acid or polyisoprenoid side chains to the inhibitor which, it is believed, will improve their lipophilic nature and enhance their cellular uptake.
[0070] Other possible structural modifications include the addition of benzyl, phenyl or acyl groups to the amino acid structures, preferably at a position sufficiently removed from the farnesyl acceptor site, such as at the amino terminus of the peptides. It is proposed that such structures will serve to improve lypophilicity. In this regard, the inventors have found that N-acetylated and N-octylated peptides such as modified CVIM retain there much of their inhibitory activity, whereas S-acetoamidated CVIM appears to lose much of its inhibitory activity.
[0071] The invention also contemplates that modifications can be made in the structure of inhibitory proteins or peptides to increase their stability within the body, such as modifications that will reduce or eliminate their susceptibility to degradation, e.g., by proteases. For example, the inventors contemplate that useful structural modifications will include the use of amino acids which are less likely to be recognized and cleaved by proteases, such as the incorporation of D-amino acids, or amino acids not normally found in proteins such as ornithine or taurine. Other possible modifications include the cyclization of the peptide, derivatization of the NH groups of the peptide bonds with acyl groups, etc.
[0072] Assays for Farnesyl:Protein Transferase
[0073] In still further embodiments, the invention concerns a method for assaying farnesyl transferase activity in a composition. This is an important aspect of the invention in that such an assay system provides one with not only the ability to follow isolation and purification of the enzyme, but it also forms the basis for developing a screening assay for candidate inhibitors of the enzyme, discussed in more detail below. The assay method generally includes simply determining the ability of a composition suspected of having farnesyl transferase activity to catalyze the transfer of farnesol to an acceptor protein or peptide. As noted above, a farnesyl acceptor protein or peptide is generally defined as a protein or peptide which will act as a substrate for farnesyl transferase and which includes a recognition site such as —C-A-A-X, as defined above.
[0074] Typically, the assay protocol is carried out using farnesyl pyrophosphate as the farnesol donor in the reaction. Thus, one will find particular benefit in constructing an assay wherein a label is present on the farnesyl moiety of farnesyl pyrophosphate, in that one can measure the appearance of such a label, for example, a radioactive label, in the farnesyl acceptor protein or peptide.
[0075] As with the characterization of the enzyme discussed above, the farnesyl acceptor sequence which are employed in connection with the assay can be generally defined by —C-A-A-X, with preferred embodiments including sequences such as —C—V—I-M —C—S—I-M, —C-A-I-M, etc., all of which have been found to serve as useful enzyme substrates. It is believed that most proteins or peptides that include a carboxy terminal sequence of —C-A-A-X can be successfully employed in farnesyl protein transferase assays. For use in the assay a preferred farnesyl acceptor protein or peptide will be simply a p21 ras protein. This is particularly true where one seeks to identify inhibitor substances, as discussed in more detail below, which function either as “false acceptors” in that they divert farnesylation away from natural substrates by acting as substrates in and or themselves, or as “pure” inhibitors which are not in themselves farnesylated. The advantage of employing a natural substrate such as p21 ras is several fold, but includes the ability to separate the natural substrate from the false substrate to analyze the relative degrees of farnesylation.
[0076] However, for the purposes of simply assaying enzyme specific activity, e.g., assays which do not necessarily involve differential labeling or inhibition studies, one can readily employ short peptides as a farnesyl acceptor in such protocols, such as peptides from about 4 to about 10 amino acids in length which incorporate the recognition signal at their carboxy terminus. Exemplary farnesyl acceptor protein or peptides include but are not limited to CVIM; KKSKTKCVIM; TKCVIM; RASNRSCAIM; TQSPQNCSIM; CIIM; CVVM; and CVLS.
[0077] Assays for Candidate Substances
[0078] In still further embodiments, the present invention concerns a method for identifying new farnesyl transferase inhibitory compounds, which may be termed as “candidate substances.” It is contemplated that this screening technique will prove useful in the general identification of any compound that will serve the purpose of inhibiting farnesyl transferase. It is further contemplated that useful compounds in this regard will in no way be limited to proteinaceous or peptidyl compounds. In fact, it may prove to be the case that the most useful pharmacologic compounds for identification through application of the screening assay will be nonpeptidyl in nature and, e.g., which will be recognized and bound by the enzyme, and serve to inactivate the enzyme through a tight binding or other chemical interaction.
[0079] Thus, in these embodiments, the present invention is directed to a method for determining the ability of a candidate substance to inhibit a farnesyl transferase enzyme, the method including generally the steps of:
[0080] (a) obtaining an enzyme composition comprising a farnesyl transferase enzyme that is capable of transferring a farnesyl moiety to a farnesyl acceptor substance;
[0081] (b) admixing a candidate substance with the enzyme composition; and
[0082] (c) determining the ability of the farnesyl transferase enzyme to transfer a farnesyl moiety to a farnesyl acceptor substrate in the presence of the candidate substance.
[0083] An important aspect of the candidate substance screening assay hereof is the ability to prepare a farnesyl transferase enzyme composition in a relative purified form, for example, in a manner as discussed above. This is an important aspect of the candidate substance screening assay in that without at least a relatively purified preparation, one will not be able to assay specifically for enzyme inhibition, as opposed to the effects of the inhibition upon other substances in the extract which then might affect the enzyme. In any event, the successful isolation of the farnesyl transferase enzyme now allows for the first time the ability to identify new compounds which can be used for inhibiting this cancer-related enzyme.
[0084] The candidate screening assay is quite simple to set up and perform, and is related in many ways to the assay discussed above for determining enzyme activity. Thus, after obtaining a relatively purified preparation of the enzyme, one will desire to simply admix a candidate substance with the enzyme preparation, preferably under conditions which would allow the enzyme to perform its farnesyl transferase function but for inclusion of a inhibitory substance. Thus, for example, one will typically desire to include within the Cadmixture an amount of a known farnesyl acceptor substrate such as a p21 ras protein. In this fashion, one can measure the ability of the candidate substance to reduce farnesylation of the farnesyl acceptor substrate relatively in the presence of the candidate substance.
[0085] Accordingly, one will desire to measure or otherwise determine the activity of the relatively purified enzyme in the absence of the added candidate substance relative to the activity in the presence of the candidate substance in order to assess the relative inhibitory capability of the candidate substance.
[0086] Methods of Inhibiting Farnesyl:Protein Transferase
[0087] In still further embodiments, the present invention is concerned with a method of inhibiting a farnesyl transferase enzyme which includes subjecting the enzyme to an effective concentration of a farnesyl transferase inhibitor such as one of the family of peptidyl compounds discussed above, or with a candidate substance identified in accordance with the candidate screening assay embodiments. This is, of course, an important aspect of the invention in that it is believed that by inhibiting the farnesyl transferase enzyme, one will be enabled to treat various aspects of cancers, such as ras-related cancers. It is believed that the use of such inhibitors to block the attachment of farnesyl groups to ras proteins in malignant cells of patients suffering with cancer or pre-cancerous states will serve to treat or palliate the cancer, and may be useful by themselves or in conjunction with other cancer therapies, including chemotherapy, resection, radiation therapy, and the like.
[0088] Genes Encoding Farnesyl:Protein Transferase Enzyme
[0089] In still further embodiments, the invention relates to the preparation of farnesyl:protein transferase through the application of recombinant DNA technology. The inventors have recently determined the feasibility of isolating genes encoding one or both of the farnesyl:protein transferase subunits. It is proposed that such recombinant genes may be employed for a variety of applications, including, for example, the recombinant production of the subunits themselves or proteins or peptides whose structure is derived from that of the subunits, in the preparation of nucleic acid probes or primers, which can, for example, be used in the identification of related gene sequences or studying the expression of the subunit(s), and the like.
[0090] It is proposed that the recombinant cloning of the genes encoding the respective α and β subunits may be achieved most readily through the use of the peptide sequence information set forth above. The direct manner in which to proceed with such cloning is through the preparation of a recombinant clone bank, preferably cDNA clone bank using poly A + RNA from a desired cell source (although it is believed that where desired, one could employ a genomic bank). In that the enzyme appears to be fairly ubiquitous in nature, it is believed that virtually any eukaryotic cell source may be employed for the initial preparation of RNA. One may mention by way of example, yeast, mammalian, plant, eukaryotic parasites and even viral-infected types of cells as the source of starting poly A + RNA.
[0091] Since the protein was initially purified from a mammalian source (rat), one may find particular advantage in employing a mammalian cell source, such as a rat or human cell line, as an RNA source. It may, however, be advantageous to first test the cell to be employed to ensure that relatively high levels of the enzyme are being produced by the selected cell line. Rat brain, PC12 (a rat adrenal tumor cell line) and KNRK (a newborn rat kidney cell line) cells are presently the most preferred by the inventors in that they very high levels of endogenous farnesyl:protein transferase activity. The inventors have proceeded in initial studies employing the foregoing cell types as sources of RNA.
[0092] It is believed that the type of cDNA clone bank is not particularly crucial. However, one will likely find particular benefit through the preparation and use of a phage-based bank, such as λgt10 or λgt11, preferably using a particle packaging system. Phage-based cDNA banks are preferred because of the large numbers of recombinants that may be prepared and screened will relative ease. The manner in which the cDNA itself is prepared is -not believed to be particularly crucial. However, the inventors believe that it may be beneficial to employ the both oligo dT as well as randomly primed cDNA in that the size of the mRNA encoding the farnesyl:protein transferase may be large and thus difficult to reverse transcribe in its entirety.
[0093] Once a clone bank has been prepared, it may be screened in a number of fashions. For example, one could employ the subunit peptide sequences set forth above for the preparation of nucleotide probes which may be employed directly to screen the bank by hybridization screening. However, a more preferred approach is to use the peptide sequences in the preparation of primers which may be used in PCR-based reactions to amplify and then sequence portions of the selected subunit gene, to thereby confirm the actual underlying DNA sequence, and to prepare longer and more specific probes for screening. These primers may also be employed for the preparation of cDNA clone banks which are enriched for 3′ and/or 5′ sequences. This may be important, e.g., where less than a full length clone is obtained through the initially prepared bank.
[0094] Once a positive clone or clones have been obtained, and engineered to ensure a full length sequence (if needed and where desired), one may proceed to prepare an expression system for the recombinant preparation of one or both subunits. It is believed that virtually any expression system may be employed for preparing one or both subunits. For example, it is envisioned that even bacterial expression systems may be employed, e.g., where one envisions using the subunit for its immunologic rather than biologic properties. of course, where a biologically active enzyme is needed, one will prefer to employ a eukaryotic expression system employing eukaryotic cells, most preferably cotransformed with DNA encoding both subunits.
[0095] It is believed that virtually any eukaryotic expression system may be employed as desired. A preferred system for expression of farnesyl:protein transferase DNA is a cytomegalo virus promoter-based expression vector in simian COS cells or human embryonic kidney 293 cells, although other systems, including but not limited to baculovirus-based, glutamine synthase-based or dihydrofolate reductase-based systems may prove to be particularly useful. It is believed that once a full length recombinant gene has been obtained, whether it be cDNA based or genomic, then the engineering of such a gene for expression in a prokaryotic or eukaryotic system may be performed by techniques generally known to those of skill in recombinant expression.
BRIEF DESCRIPTION OF THE DRAWINGS
[0096] The invention is described in part by reference to the following figures:
[0097] [0097]FIG. 1. Transfer of Farnesol from [ 3 H]FPP to p21 H-ras by Partially Purified Rat Brain Farnesyl:Protein Transferase. Each standard assay mixture contained 10 pmoles of ( 3 H]FPP and 3.5 μg of partially purified farnesyl transferase in the absence (▴) or presence () of 40 μM p21 H-ras . Duplicate samples were incubated for the indicated time at 37° C., and TCA-precipitable radioactivity was measured as described in the Examples. The inset shows the migration on a 12% SDS polyacrylamide gel of an aliquot from a reaction carried out for 1 h in the absence or presence of p21 H-ras . The gel was treated with Entensify solution (DuPont), dried, and exposed to XAR film for 2 days at −70° C.
[0098] [0098]FIG. 2. Substrate Saturation Curves for Farnesyl:Protein Transferase. Panel A, each standard reaction mixture contained 1.8 μg of partially purified farnesyl transferase, 40 μg p21 H-ras , [ 3 H]FPP (250,000 dpm); and varying amounts of unlabeled FPP to give the indicated final concentration of [ 3 H]FPP. Panel B, each standard reaction mixture contained 3.2 μg partially purified farnesyl transferase, 10 pmol [ 3 H]FPP, and the indicated concentration of p21 H-ras that had been incubated with 50 μM of the indicated nucleotide for 45 min at 30° C. and then passed through a G-50 Sephadex gel filtration column at room temperature in buffer containing 10 mM Tris-chloride (pH 7.7), 1 mM EDTA, 1 mM DTT, and 3 mM MgCl 2 . For both panels, assays were carried out in duplicate for 1 h at 37° C., and TCA-precipitable radioactivity was measured as described in the Example.
[0099] [0099]FIG. 3. Divalent Cation Requirement for Farnesyl:Protein Transferase. Each standard reaction mixture contained 10 pmol ( 3 H]FPP, 2.5 μg of partially purified farnesyl transferase, 40 μM p21 H-ras , 0.15 mM EDTA, and the indicated concentrations of either ZnCl 2 () or MgCl 2 (▴). Incubations were carried out in duplicate for 1 h at 37° C., and TCA-precipitable radioactivity was measured as described in the Examples.
[0100] [0100]FIG. 4. Identification of ( 3 H]FPP-derived Radioactive Material Transferred to p21 H-ras . Panel A, an aliquot from a standard reaction mixture was subjected to cleavage with methyl iodide as described in the Examples. Panel B, another aliquot was treated identically except methyl iodide was omitted. After cleavage, the extracted material was dried under nitrogen, resuspended in 0.4 ml of 50% (v/v) acetonitrile containing 25 mM phosphoric acid and 6 nmoles of each isoprenoid standard as indicated. The mixture was subjected to reverse phase HPLC (C18, Phenomex) as described by Casey, et al. (6) except that an additional 10-min wash with 100% acetonitrile/phosphoric acid was used. The isoprenoid standards were identified by absorbance at 205 nm: C 10 , all-trans geranylgeraniol.
[0101] [0101]FIG. 5. Chromatography of Farnesyl:Protein Transferase on a Mono Q Column. The 30-50% ammonium sulfate fraction from rat brain (200 mg) was applied to a Mono Q column (10×1-cm) equilibrated in 50 mM Trischloride (pH 7.5) containing 1 mM DTT, 20 μM ZnCl 2 , and 0.05 M NaCl. The column was washed with 24 ml of the same buffer containing 0.05 M NaCl, followed by a 24-ml linear gradient from 0.05 to 0.25 M NaCl, followed by a second wash with 24 ml of the same buffer containing 0.25 M NaCl. The enzyme was then eluted with a 112-ml linear gradient of the same buffer containing 0.25-1.0 M NaCl at a flow rate of 1 ml/min. Fractions of 4 ml were collected. An aliquot of each fraction (2 μl) was assayed for farnesyl:protein transferase activity by the standard method (∘). The protein content of each fraction () was estimated from the absorbance at 280 mM.
[0102] [0102]FIG. 6A. SDS Polyacrylamide Gel Electrophoresis of Farnesyl:Protein Transferase at Various Stages of Purification. 10 μg of the 30-50% ammonium-sulfate fraction (lane 1), 3 μg of the Mono Q fraction (lane 2), and approximately 90 ng of the peptide affinity-column fraction (lane 3) were subjected to SDS-10% polyacrylamide gel electrophoresis, and the protein bands were detected with a silver stain. The farnesyl:protein transferase activity in each sample loaded onto the gel was approximately 0.1, 0.8, and 54 units/lane for lanes 1, 2, and 3, respectively. The molecular weights for marker protein standards are indicated. Conditions of electrophoresis: 10% mini gel run at 30 mA for 1 h.
[0103] [0103]FIG. 6B. SDS Polyacrylamide Gel Electrophoresis of Purified Farnesyl:Protein Transferase. 0.7 μg of the peptide affinity-purified-column fraction (right lane) was subjected to SDS-10% polyacrylamide gel electrophoresis, and the protein bands were detected with a Coomassie Blue Stain. The molecular weights for marker protein standards (left lane) are indicated. Conditions of electrophoresis: 10% standard size gel run at 30 mA for3 h.
[0104] [0104]FIG. 7. Gel Filtration of Farnesyl:Protein Transferase. Affinity-purified farnesyl transferase farnesyl transferase ( 18 1 μg protein) was subjected to gel filtration on a Superose-12 column (25×0.5-cm) in 50 mM Tris-chloride (pH 7.5) containing 0.2 M NaCl, 1 mM DTT, and 0.2% octyl-β-D-glucopyranoside at a flow rate of 0.2 ml/min. Fractions of 0.5 ml were collected. Panel A, a 6-μl aliquot of each fraction was assayed for farnesyl:protein transferase activity by the standard method except that each reaction mixture contained 0.2% octyl-β-D-glucopyranoside. The column was calibrated with thyroglobulin (670 kDa), γ-globulin (158 kDa), ovalbumin (44 kDa), myoglobin (17 kDa), and vitamin B12 (1.35 kDa). Arrows indicate the elution position of the 158-kDa and 44-kDa markers. Panel B, a 0.42-ml aliquot of each fraction was concentrated to 40 μl with a Centricon 30 Concentrator (Amicon), and 25 μl of this material was then subjected to electrophoresis on an 10% SDS polyadrylamide gel. The gel was stained with silver nitrate and calibrated with marker proteins (far-right lane).
[0105] [0105]FIG. 8. Inhibition of Farnesyl:Protein Transferase Activity by Peptides. Each standard reaction mixture contained 10 pmol [ 3 H]FPP, 1.8 μg of partially purified farnesyl:protein transferase, 40 μM p21 H-ras , and the indicated concentration of competitor peptide added in 3 μl of 10 mM DTT. After incubation for 1 h at 37° C., TCA-precipitable radioactivity was measured as described in Experimental Procedures. Each value is the mean of triplicate incubations (no peptide) or a single incubation (+peptide). A blank value of 0.11 pmol/h was determined in a parallel incubation containing 20 mM EDTA. This blank was subtracted from each value before calculating “% of control” values. The “100% of control” value after subtraction of the blank was 3.78 pmol of [ 3 H]FPP p21 H-ras formed per h. Peptides Δ, ∘ and ∘ correspond to the COOH-terminal 10, 6, and 4 amino acids of wild-type human p21 H-ras protein, respectively. Peptides □ and ▴ are control peptides.
[0106] [0106]FIG. 9. Inhibition of Farnesyl:Protein Transferase Activity by Peptides. Incubations were carried out exactly as described in the legend to FIG. 8. The “100% of control value” was 2.92 pmol of ( 3 H]farnesyl p21 H-ras formed per hour. The blank value was 0.20 pmol/h. Each peptide consisted of the COOH-terminal 10 residues of the indicated protein.
[0107] [0107]FIG. 10. Inhibition of Farnesyl:Protein Transferase By Tetrapeptide Analogues of CVIM. The standard assay mixture contained 15 pmol [ 3 H]FPP, 4 to 7.5 μg partially purified farnesyl transferase, 30 or 40 μM p21 Hras , and the indicated concentration of competitor tetrapeptide. After 30 or 60 min, the amount of [ 3 H]farnesyl attached to p21 H-ras was measured by trichloracetic acid precipitation as described in the methods section of Example II. Each value is the average of duplicate or triplicate incubations (no peptide) or a single incubation (+peptide). Each tetrapeptide was tested in a separate experiment together with equivalent concentrations of CVIM. The values for inhibition by CVIM ( . . . ) represent mean values from 21 experiments in which the mean “100% of control” value was 13 pmol min −1 mg protein −1 . K i concentration of tetrapeptide giving 50% inhibition. CVIA is SEQ ID NO: 18 and CVAM is SEQ ID No: 23.
[0108] [0108]FIG. 11. Inhibition of Farnesyl:Protein Transferase Activity By Phenylalanine-Containing Analogues of CVIM. Enzyme activity was measured in the presence of the indicated concentration of competitor tetrapeptide as described in the legend to FIG. 10. CVFM is SEQ ID NO: 28, CFIM is SED ID NO: 27 and CVIF is SEQ ID NO: 29.
[0109] [0109]FIG. 12. Inhibition of Farnesylation of p21 H-ras (A) and Biotinylated KTSCVIM (SEQ ID NO: 41) (B) By CVFM (SEQ ID NO: 28). Panel A: Each reaction mixture contained 15 pmol [ 3 H]FPP, 4.5 or 6 ng of purified farnesyl:protein transferase, 40 μM p21 H-ras , and the indicated concentration of competitor tetrapeptide. After incubation for 30 min at 37° C., the amount of [ 3 H]farnesyl transferred to p21 H-ras was measured by the standard filter assay. Values shown are the average of two experiments. The “100% of control” values were 16 and 19 nmol min −1 mg protein −1 . Panel B: Each reaction contained 15 pmol [ 3 H]FPP, 4.5 or 6 ng of purified farnesyl:protein transferase, 3.4 μM biotinylated KTSCVIM, and the indicated concentration of competitor tetrapeptide. After incubation for 30 min at 37° C., the [ 3 H]farnesyl-labeled peptide was trapped on streptavidinagarose, washed, separated from the unincorporated (3H]FPP, and subjected to scintillation counting. Values shown are the mean of 3 experiments. The “100% of control” values were 10, 17, and 21 nmol min −1 mg protein −1 .
[0110] [0110]FIG. 13. Inhibition of Farnesyl:Protein Transferase By Modified Tetrapeptides. Enzyme activity was measured in the presence of varying concentrations of the indicated tetrapeptide as described in the legend to FIG. 10. The “100% of control” values were 9.3 and 9.2 pmol min −1 mg protein −1 in Panels A and B, respectively.
[0111] [0111]FIG. 14. Inhibition of Farnesyl:Protein Transferase By Tetrapeptides With Single Amino Acid Substitutions in CVIM. Enzyme activity was measured in the presence of the indicated competitor tetrapeptide as described in the legend to FIGS. 10 and 11 . Each tetrapeptide was tested at seven different concentrations ranging from 0.01 to 100 μM. The concentration of tetrapeptide giving 50% inhibition was calculated from the inhibition curve. The single and double underlines denote tetrapeptides corresponding to the COOH-terminal sequence of mammalian and fungal proteins, respectively, that are candidates for farnesylation (see Table III).
[0112] [0112]FIG. 15. Farnesylation of CVIM but not CVFM by purified farnesyl:protein transferase. The standard assay mixture (25 μl) contained 17 pmol [ 3 H]FPP (44,000 dpm/pmol), 5 ng of purified farnesyl:protein transferase, 0.2% (w/v) octyl-β-D-glucoside, and 3.6 μM of the indicated tetrapeptide. After incubation for 15 min at 37° C., the entire reaction mixture was subjected to thin layer chromatography for 4 h on Polygram SIL G sheet (Brinkmann Instruments) in a solvent system containing N-propanol/concentrated NH 4 OH/water (6:3:1). The TLC sheet was then dried, sprayed with ENHANCE Spray (Dupont-New England Nuclear) and exposed to Kodak X-OMAT AR Film XAR-5 for 25 h at −70° C. SVIM is SEQ ID NO: 42 and CVFM is SEQ ID NO: 28.
[0113] [0113]FIG. 16. A description of primers proposed for use in the cloning of the α subunit gene. In the Figure, Primer 1 is SEQ ID NO: 43; Primer 2 is SEQ ID NO: 45, reading in the direction of the arrow; the amino acid sequence is SEQ ID NO: 44; and the 38-mer is SEQ ID NO: 46.
[0114] [0114]FIG. 17. A description of primers proposed for use in the cloning of the β subunit gene. In the Figure, Primer 1 is SEQ ID NO: 47; the longer primer immediately below in the figure is SEQ ID NO: 48; Primer 2 is SEQ ID NO: 49, reading in the direction of the arrow; the amino acid sequence is SEQ ID NO: 7; and the 40-mer is SEQ ID NO: 50.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0115] The following examples illustrate techniques discovered by the inventors for the identification and purification of farnesyl protein transferase enzyme, as well as techniques for its assay and for the screening of new compounds which may be employed to inhibit this enzyme. These studies also demonstrate a variety of peptidyl compounds which themselves can be employed to inhibit this enzyme. It should be appreciated by those of skill in the art that the techniques disclosed in the examples which follow represent laboratory techniques discovered by the inventors to function well in the practice of the invention, and thus can be considered to constitute preferred modes for its practice. However, those of skill in the art should, in light of the present disclosure, appreciate that many changes can be made in the specific embodiments which are disclosed and still obtain a like or similar result without departing from the spirit and scope of the invention.
EXAMPLE I
Preparation and Characterization of Farnesyl:Protein Transference
[0116] 1. Materials
[0117] Peptides were obtained from Peninsula Laboratories or otherwise synthesized by standard techniques All peptides were purified on HPLC, and their identity was confirmed by amino acid analysis. Just prior to use, each peptide was dissolved at a concentration of 0.8 mM in 10 mM dithiothreitol (DTT), and all dilutions were made in 10 mM DTT. Unlabeled farnesyl pyrophosphate (FPP) was synthesized by the method of Davisson, et al. (13). (1- 3 H]Farnesyl pyrophosphate (20 Ci/mmol) was custom synthesized by New England Nuclear. Geraniol and farnesol (both all-trans) were obtained from Aldrich Chemical. All-trans geranylgeraniol. was a gift of R. Coates (University of Illinois).
[0118] Recombinant wild type human p21 H-ras protein was produced in a bacterial expression system with pAT-rasH (provided by Channing J. Der, La Jolla Cancer Research Foundation, La Jolla, Calif.), an expression vector based on PXVR (14). The plasmid was transformed into E. coli JM105, and the recombinant p21 H-ras protein was purified at 4° C. from a high speed supernatant of the bacterial extracts by sequential chromatography on DEAE-Sephacel and Sephadex G-75. Purity was ˜ 90% as judged by Coomassie blue staining of SDS gels. Purified p21 H-ras was concentrated to 15 mg/ml in 10 mM Tris-chloride (pH 7.5) containing 1 mM DTT, 1 mM EDTA, 3 MM MgCl 2 , and 30 μM GDP and stored in multiple aliquots at −70° C.
[0119] 2. Assay for Parnesyl:Protein Transferase Activity
[0120] Farnesyl:protein transferase activity was determined by measuring the amount of 3 H-farnesol transferred from [ 3 H]farnesyl pyrophosphate ([ 3 H]FPP) to p21 H-ras protein. The standard reaction mixture contained the following concentrations of components in a final volume of 25 μl: 50 mM Tris-chloride (pH 7.5), 50 μM ZnCl 2 , 20 mM KCl, 1 mM DTT, and 40 μM p21 H-ras . The mixture also contained 10 pmoles of [ 3 H]FPP (˜30,000 dpm/pmol) and 1.8-3.5 μg of partially purified farnesyl:protein transferase (see below). After incubation for 1 h at 37° C. in 12×75-mm borosilicate tubes, the reaction was stopped by addition of 0.5 ml of 4% SDS and then 0.5 ml of 30% trichloroacetic acid (TCA).
[0121] The tubes were vortexed and left on ice for 45-60 min, after which 2 ml of a 6% TCA/2% SDS solution were added. The mixture was filtered on a 2.5-cm glass fiber filter with a Hoefer filtration unit (FH 225). The tubes were rinsed twice with 2 ml of the same solution, and each filter was washed five times with 2 ml of 6% TCA, dried, and counted in a scintillation counter. One unit of activity is defined as the amount of enzyme that transfers 1 pmol of [ 3 H]farnesol from [ 3 H)FPP into acid-precipitable p21 H-ras per hour under the standard conditions.
[0122] 3. Purification of Farnesyl:Protein Transferase
[0123] All steps were carried out at 4° C. except where indicated:
[0124] Step 1—Ammonium Sulfate Fractionation: Brains from 50 male Sprague-Dawley rats (100-150 g) were homogenized in 100 ml of ice-cold buffer containing 50 mM Trischloride (pH 7.5), 1 mM EDTA, 1 mM EGTA, 0.2 mM phenylmethylsulfonyl fluoride, and 0.1 mM leupeptin, and the extract was spun at 60,000×g for 70 min. The supernatant was brought to 30% saturation with solid ammonium sulfate, stirred for 30 minutes on ice, and centrifuged at 12,000×q for 10 min to remove precipitated proteins. The resulting supernatant was adjusted to 50% saturation with ammonium sulfate, and the resulting pellet was dissolved in ˜ 20 ml of 20 mM Trischloride (pH 7.5) containing 1 mM DTT and 20 μM ZnCl 2 and dialyzed for 4 hours against 4 liters of the same buffer and then 4 liters of fresh buffer of the same composition for 12 h. The dialyzed material was divided into multiple aliquots and stored at ˜70° C.
[0125] Step 2—Ion-exchange Chromatography: A portion of the 30-50% ammonium sulfate fraction (200 mg protein) was chromatographed on a Mono Q 10/10 column using an FPLC system (Pharmacia LKB Biotechnology). The column was run as described in the legend to FIG. 5. Fractions eluting between 0.3 and 0.4 M NaCl contained the majority of the transferas e activity. These fractions were pooled, divided into multiple aliquots, and stored at −70° C.
[0126] Step 3—Affinity Chromatography: An affinity column containing a peptide corresponding to the COOH-terminal six amino acids of p2 K-ras-B protein was prepared as follows. Fifteen mg of the peptide TKCVIM were coupled to 1 g of activated CH-Sepharose 4B (Pharmacia LKB Biotechnology) according to the manufacturer's instructions. The resulting 2.5-ml slurry was poured into a column, and excess uncoupled peptide was removed by 10 cycles of alternating washes, each consisting of 40 column volumes of 0.1 M sodium acetate (pH 4.0) and then 0.1 M Tris-chloride (pH 8.0). Both buffers contained 1 M NaCl and 10 mM DTT. The column was stored at 4° C. in 20 mM Tris-chloride (pH 7.2) and 0.02% sodium azide. Fifteen mg of Mono Q-purified material in 10 ml were applied to a 1-ml peptide column equilibrated in 50 mM Tris-chloride (pH 7.5) containing 0.1 M NaCl and 1 mM DTT (Buffer A). The enzyme-containing solution was cycled through the column three times at room temperature. The column was washed with 20 ml of Buffer A containing 0.2% (w/v) octyl-β-D-glucopyranoside (Buffer B). The enzyme was eluted with 20 ml of 50 mM Trissuccinate (pH 5.0) containing 1 mM DTT, 0.1 M NaCl, and 0.2% octyl-β-D-glucopyranoside. The pH 5 eluate was concentrated and washed twice with a 10-fold excess of Buffer B in a CF25 Centriflo ultrafiltration cone (Amicon) and brought to 1 ml (10-fold concentration relative to the starting material).
[0127] Step 4 Gel Filtration: Affinity-purified farnesyl transferase ( ˜ 1 μg) was chromatographed on a Superose 12 column as described in the legend to FIG. 7.
[0128] In the enzyme characterization experiments of FIGS. 1 - 4 , 8 , and 9 , a partially purified fraction of farnesyl:protein transferase was used. This enzyme was prepared by Steps 1 and 2 as described above, after which 6 mg of the Mono Q-purified material was concentrated to 2 ml and then loaded onto a 1.6×50-cm Sephacryl S-200 high resolution gel filtration column (Pharmacia LKB Biotechnology). The column was equilibrated with 50 mM Tris-chloride (pH 7.5) containing 1 mM DTT, 0.2 M NaCl, 20 μM ZnCl 2 , and 0.2% octyl-β-glucopyranoside and eluted with the same buffer at a flow rate of 15 ml/h. Only the peak fraction, containing 1 mg protein and 40% of initial activity, was used for studies.
[0129] 4. Identification of 3 H-Isoprenoid Transferred from [ 3 H]FPP
[0130] A modification of the procedure described by Casey et al. (ref 6) was employed as follows: Briefly, two standard transferase reactions of 25-μl each were conducted for 1 hour at 37° C. The mixtures were then pooled, and a 25-μl aliquot from the 50-μl pooled sample was diluted to 250 μl with 2% (w/v) SDS. This mixture was precipitated with an equal volume of 30% TCA, filtered through nitrocellulose, (7 mm disc), washed twice with 250 μl 6% TCA/2% SDS followed by five washes with 5% TCA, digested with 8 μg trypsin, and subjected to cleavage with methyl iodide. The released 3 H-isoprenoids were extracted into chloroformn/methanol and chromatographed on a reverse-phase TPLC system as described in the legend to FIG. 4.
[0131] 5. Other Methods
[0132] SDS polyacrylamide gel electrophoresis was carried out as described by Laemmli (16). Gels were calibrated with high range SDS-PAGE standards (Bio-Rad). Protein content of extracts was measured by the method of Lowry, et al. (17) except for that of the affinity-purified material, which was estimated by comparison to the bovine serum albumin marker (M r 66, 000) following SDS gel electrophoresis and Coomassie staining.
[0133] 6. Discussion
[0134] As an initial attempt to identify a farnesyl protein transferase enzyme, rat brain cytosol was fractionated with ammonium sulfate and the active fraction subjected to ion exchange chromatography on a Mono Q column followed by gel filtration on Sephacryl S-200. FIG. 1 shows that the active fraction from this column incorporated radioactivity from ( 3 H]farnesol into trichloroacetic acid precipitable p21 H-ras in a time-dependent fashion at 37° C. The incorporated radioactivity could be visualized as a band of the expected molecular weight of 18 21 kDa on SDS polyacrylamide gels (inset). The concentration of [ 3 H]farnesyl pyrophosphate that gave half-maximal reaction velocity was approximately 0.5 μM (FIG. 2A). The half-maximal concentration for p21 H-ras was approximately 5 μM, and there was no difference when the p21 H-ras was equilibrated with a non-hydrolyzable GTP or ATP analogue or with GDP (FIG. 2B).
[0135] With p21 H-ras as a substrate, the transferase reaction was inhibited by 0.15 mM EDTA, and this inhibition was reversed by 0.1 to 1.0 mM concentrations of zinc or magnesium chloride (FIG. 3). At higher concentrations of zinc chloride, inhibition was observed.
[0136] To confirm that the transferred material was [ 3 H]farnesol, the washed trichloracetic acid-precipitated material was digested with trypsin, the radioactivity released with methyl iodide, and the products subjected to reverse-phase HPLC. The methyl iodide-released material co-migrated with an authentic standard of all-trans farnesol (C 15 ) (FIG. 4A). Some radioactivity emerged from the column prior to the geranol standard (C 10 ), but this was the same in the presence and absence of methyl iodide treatment. This early-eluting material was believed to represent some tryptic peptides whose radioactivity was not released by-methyl iodide.
[0137] [0137]FIG. 5 shows the elution profile of farnesyl transferase activity from a Mono Q column. The activity appeared as a single sharp peak that eluted at approximately 0.35 M sodium chloride.
[0138] The peak fractions from the Mono Q column were pooled and subjected to affinity chromatography on a column that contained a covalently-bound peptide corresponding to the carboxyl-terminal 6-amino acids of p21 K-rasB . All of the farnesyl transferase activity was adsorbed to the column, and about 50% of the applied activity was recovered when the column was eluted with a Tris-succinate buffer at pH 5.
[0139] Table II summarizes the results of a typical purification procedure that started with 50 rat brains. After ammonium sulfate precipitation, mono Q chromatography, and affinity chromatography, the farnesyl transferase was purified approximately 61,000-fold with a yield of 52%. The final specific activity was about 600,000 units/mg.
TABLE II PURIFICATION OF FARNESYL-PROTEIN TRANSFERASE FROM RAT BRAIN Specific Total Protein Activity Activity Purification Recovery Fraction mg Units/mg Units -fold % 30-50% 712 9.7 a 6906 1 100 Ammononium Sulfate Mono Q 30 275 8250 28 119 Affinity ˜0.006 b 600,000 3600 61,855 52 Column
[0140] [0140]FIG. 6A shows the SDS gel electrophoretic profile of the proteins at each stage of this purification as visualized by silver staining. The peptide affinity column yielded a single protein band with an apparent subunit molecular weight of 50,000. When the purified enzyme was subjected to SDS gel electrophoresis under more sensitive conditions, the 50-kDa protein could be resolved into two closely spaced bands that were visualized in approximately equimolar amounts (FIG. 6B).
[0141] To confirm that the 50-kDa band was the farnesyl transferase enzyme, the affinity column purified material was subjected to gel filtration. FIG. 7 shows that the farnesyl transferase activity and the 50-kDa band co-eluted from this column at a position corresponding to an apparent molecular weight of 70-100 kDa as determined from the behavior of markers of known molecular weight.
[0142] The adherence of the farnesyl transferase to the peptide affinity column suggested that the enzyme was capable of recognizing short peptide sequences. To test for the specificity of this peptide recognition, the ability of various peptides to compete with p21 H-ras for the farnesyl transferase activity was measured. The peptide that was used for affinity chromatography corresponded to the carboxyl terminal six amino acids of p21 K-rasB (TKCVIM). As expected, this peptide competitively inhibited farnesylation of P21 H-ras as (open circles in FIG. 8). The terminal 4-amino acids in this sequence (CVMI) (closed circles) were sufficient for competition. These two short peptides were-no less effective than a peptide that contained the final 10 amino acids of the sequence (KKSKTKCVIM) (open triangles). The simple transposition of the cysteine from the fourth to the third position from the COOH-terminus of the hexapeptide (TKVCIM) (closed triangles) severely reduced inhibitory activity. An irrelevant peptide (closed squares) also did not inhibit.
[0143] [0143]FIG. 9 compares the inhibitory activities of four peptides of 10-amino acids each, all of which contain a cysteine at the fourth position from the COOH-terminus. The peptides corresponding to the COOH-terminus of human p21K-rasB and human lamin A and lamin B all inhibited farnesylation. All of these peptides are known to be prenylated in vivo (6, 15). On the other hand, the peptide corresponding to the sequence of rat Giαl, a 40 kDa G protein that does not appear to be farnesylated in vivo (Casey, P., unpublished observations), did not compete for the farnesyl transferas e reaction.
[0144] In data not shown it was found that the 10-amino acid peptide corresponding to the COOH-terminus, of p21 H-ras (CVLS), p21 N-ras (CVVM), and p21 H-ra A (CIIM) all competed for the farnesylation reaction.
EXAMPLE II
Further Characterization of Farnesyl:Protein Transferase
[0145] In the present Example, a series of tetrapeptides were tested for their ability to bind to the rat brain p21 H-ras farnesyl: protein transferase as estimated by their ability to compete with p21 H-ras , in a farnesyl transfer assay. Peptides with the highest affinity had the structure Cys-A1-A2-X, where A1 and A2 are aliphatic amino acids and X is a C-terminal methionine, serine, or phenylalanine. Charged residues reduced—affinity slightly at the A1 position and much more drastically at the A2 and X positions. Effective inhibitors included tetrapeptides corresponding to the COOH-termini of all animal cell proteins known to be farnesylated. In contras t, the tetrapeptide CAIL, which corresponds to the COOH-terminus of the only known examples of geranylgeranylated proteins (neural G protein γ subunits) did not compete in the farnesyl transfer assay, suggesting that the two isoprenes are transferred by different enzymes. A biotinylated hexapeptide corresponding to the COOH-terminus of p21 K-rasB was farnesylated, suggesting that at least some of the peptides serve as substrates for the transferase. The data are consistent with a model in which a hydrophobic pocket in the farnesyl:protein transferase recognizes tetrapeptides through interactions with the cysteine and the last two amino acids.
[0146] 1. Materials and Methods
[0147] a. Peptides
[0148] Peptides were prepared by established procedures of solid-phase synthesis (18) Tetrapeptides were synthesized on the Milligen 9050 Synthesizer using Fmoc chemistry. After deprotection of the last residue, a portion of the resin was used to make the N-acetyl-modified version of CVIM. This was done off-line in a solution of acetic anhydride and dimethylformamide at pH 8 (adjusted with diisopropylethylamine). The acetylated and unacetylated peptides were cleaved with 50 ml of trifluoroacetic acid:phenol (95:5) plus approximately 1 ml of ethanedithiol added as a scavenger. The N-octyl-modified version of CVIM was synthesized on an Applied Biosystems Model 430 Synthesizer using tBoc chemistry. The octyl group was added in an amino acid cycle using octanoic acid. The peptide was cleaved from the resin at 0° C. with a 10:1:1 ratio of HF (mls):resin (g):anisole (ml). The peptides were purified by high pressure liquid chromatography (HPLC) on a Beckman C18 reverse phase column (21.1 cm×15 cm), eluted with a water-acetonitrile gradient containing 0.1% (v/v) trifluouroacetic acid. Identity was confirmed for all peptides by fast atom bombardment (FAB) mass spectrometry. Just prior to use, each peptide was dissolved at a concentration of 0.8 mM in 10 mM dithiothreitol (DTT), and all dilutions were made in 10 mM DTT.
[0149] Biotinylated KTSCVIM was synthesized on an Applied Biosystems 430A Synthesizer. The biotin group was added after removal of the N-terminal protecting group before cleavage of the peptide from the resin. specifically, a 4-fold molar excess of biotin 4-nitrophenyl ester was added to the 0.5 g resin in 75 ml dimethylformanide at pH 8 and reacted for 5 h at room temperature. Cleavage, identification, and purification were carried out as described above.
[0150] To synthesize S-acetoamido CVIM, purified CVIM was dissolved at a final concentration of 1 mM in 0.1 ml of 0.5 M Tris-chloride (pH 8.0) containing 15 mM DTT. The tube was flushed with nitrogen for 2 min, sealed, and incubated for 2.5 h at 37° C. to reduce the cysteine residue, after which iodoacetamide was added to achieve a final concentration of 35 mM. After incubation for 15 min at 37° C., the reaction was stopped by addition of 10 mM DTT. Complete alkylation of CVIM was confirmed by FAB spectrometry and HPLC. The molecular weight of the product corresponded to the expected molecular mass of Sacetoamido CVIM.
[0151] b. Assay for Farnesyl:Protein Transferase
[0152] The standard assay involved measuring-the amount of [ 3 H]farnesyl transferred from all-trans [ 3 H]FPP to recombinant human p21 H-ras described in Example I. Each reaction mixture contained the following concentrations of components in a final volume of 25 μl:50 mM Tris-chloride (pH 7.5), 50 μM ZnCl 2 , 30 mM KCl, 1 mM DTT, 30 or 40 μM p21 H-ras 15 pmol [ 3 H]FPP (12-23,000 dpm/pmol), 4 to 7.5 μg of partially purified farnesyl:protein transferase (Mono Q fraction, see Example I), and the indicated concentration of competitor peptide added in 3 μl of 10 mM DTT. After incubation for 30-60 min at 37° C., the amount of( 3 H)farnesyl present in trichloroacetic acid-precipitable p21 H-ras was measured by a filter assay as described in Example I. A blank value (<0.6% of input [ 3 H]FPP) was determined in parallel incubations containing no enzyme. This blank value was subtracted before calculating “% of control” values.
[0153] C. Transfer of [ 3 H]Farnesyl from [ 3 H]FPP to Biotinylated KTSCVIM Peptide
[0154] This assay takes advantage of the fact that peptides containing the Cys-AAX motif of ras proteins can serve as substrates for prenylation by farnesyl transferase. A heptapeptide containing the terminal four amino acids of p21 K-rasB was chosen as a model substrate since it has a 20 to 40-fold higher affinity for the enzyme than does the COOH-terminal peptide corresponding to p21 H-ras . A biotinylated peptide is used as substrate so that the reaction product, [ 3 H]farnesylated peptide, can be trapped on a solid support such as streptavidinagarose. The bound [ 3 H]farnesylated peptide can then be washed, separated from unincorporated [ 3 H]FPP, and subjected to scintillation counting.
[0155] The biotin-modified KTSCVIM is synthesized on an Applied Biosystems 430A Synthesizer using established procedures of solid phase peptide synthesis. The biotin group is added after deprotection of lysine and before cleavage of the peptide from the resin. The identity and purity of the biotinylated peptide is confirmed by quantitative amino acid analysis and fast atom bombardment (FAB) mass spectrometry.
[0156] An aliquot of biotinylated KTSCVIM (0.4 mg) is dissolved in 0.6 ml of 10 mM sodium acetate (pH 3) buffer containing 1 mM DTT and 50% ethanol to give a final concentration of 0.67 mg/ml or 601 μM. This solution can be stored at 4° C. for at least 1 month. Immediately prior to use, the peptide solution is diluted with 1 mM DTT to achieve a peptide concentration of 18 μM. The standard reaction mixture contains the following components in a final volume-of 25 μl: 50 mM Tris-chloride (pH 7.5), 50 μM ZnCl 2 , 20 mM KCl, 1 mM DTT, 0.2% (V/V) octyl-β-glucopryranoside, 10-15 pmol of [ 3 H]FPP (15-50,000 dpm/pmol), 3.6 μM biotinylated KTSCVIM, and 2-4 units of enzyme. After incubation at 37° C. for 30-60 min in 0.5-ml siliconized microfuge tubes, the reaction is stopped by addition of 200 μl of 20 mM Tris-chloride (pH 7.5) buffer containing 2 mg/ml bovine serum albumin, 2% SDS, and 150 mnM NaCl. A 25-μl aliquot of well mixed streptavidinagarose (Bethesda Research Laboratories, Cat. No. 5942SA) is then added, and the mixture is gently shaken for 30 min at room temperature to allow maximal binding of the [ 3 H]farnesylated peptide to the beads.
[0157] The beads are then collected by spinning the mixture for 1 min in a microfuge (12,500 rpm). The supernatant is removed, and the beads are washed three times with 0.5 ml of 20 mM Tris-chloride (pH 7.5) buffer containing 2 mg/ml bovine serum albumin, 4% SDS, and 150 mM NaCl. The pellet is resuspended in 50 μl of the same buffer and transferred to a scintillation vial using a 200-μl pipettor in which the tip end has been cut off at an angle. The beads remaining in the tube are collected by rinsing the tube with 25 μt of the above buffer and adding it plus the pipettor to the vial. A blank value, which consists of the radioactivity adhering to the beads in parallel incubations containing no enzyme, should be less than 0.5% of the input [3H]FPP.
[0158] 2. Results
[0159] To screen peptides for their affinity for the farnesyl:protein transferase, studies were conducted wherein the ability of the peptides to compete with p21 H-ras for acceptance of [ 3 H]farnesyl from [ 3 H]FPP as catalyzed by a partially purified rat brain farnesyl:protein transferase was tested. As a reference point for the peptides, the tetrapeptide CVIM corresponding to the COOH-terminal sequence of p21 K-rasB was employed. FIG. 10 shows a series of typical experiments in which alanine (Panel A), lysine (Panel B), or leucine (Panel C) was systematically substituted at each of the three positions following cysteine in CVIM. In each experiment the results were compared with those obtained with CVIM. Alanine and lysine were tolerated only at the A1 position. Insertion of these amino acids at the A2 or X positions decreased the affinity for the enzyme by more than 30-fold as estimated by the concentration required for 50% inhibition. Leucine was tolerated at the A2 position, but it decreased the affinity when inserted at the X position.
[0160] The substitution of phenylalanine for isoleucine at the A2 position increased the affinity for the enzyme by 6-fold, with half-maximal inhibition occurring at 25 nM (FIG. 11). No such effect was observed when phenylalanine was inserted at either of the other two positions.
[0161] In addition to performing assays with-p21 H-ras as a substrate, assays were also performed in which the substrate was a biotinylated heptapeptide, KTSCVIM, which contains the COOH-terminal four amino acids of p21 H-rasB (2). The biotin was attached to the NH 2 -terminus by coupling to the resin-attached peptide. The [ 3 H]farnesylated product was isolated by allowing it to bind to beads coated with streptavidin as described in section c. above.
[0162] [0162]FIG. 12 shows that the peptide CVFM was more potent than CVIM when either p2 H-ras or the biotinylated heptapeptide was used as acceptor (Panels A and B, respectively). In contrast to the other studies, which were conducted with a partially purified enzyme, the studies of FIG. 12 were carried out with a homogeneous preparation of affinity-purified farnesyl:protein transferase.
[0163] The free sulfhydryl group for the cysteine is likely required for tetrapeptide inhibition, as indicted by the finding that derivitization with iodoacetamide abolished inhibitory activity (FIG. 13A). A blocked NH 2 -terminus is not required, as indicated by similar inhibitory activity of N-acetyl CVIM and N-octyl CVIM (FIG. 13B) as compared to that of CVIM (FIG. 13).
[0164] [0164]FIG. 14 summarizes the results of all competition assays in which substitutions in the CVIM sequence were made. The results are presented in terms of the peptide concentration required for 50% inhibition. Table III summarizes the results of other experiments in which tetrapeptides corresponding to the COOH-termini of 19 proteins were studied, many of which are known to be farnesylated. The implications of these studies are discussed below in Section 3.
TABLE III Inhibition of Rat Farnesyl: Protein Transferase by COOH-Terminal Tetrapeptides Corresponding to Known Proteins COOH-Terminal Concentration For 50% Inhibition Protein Species Tetrapeptide μm *p21 K-rasB Human, mouse CVIM 0.15 *p21 K-rasA Human CIIM 0.15 p21 N-ras Human CVVM 0.15 p21 N-ras Mouse CVLM *Lamin B Human, Xenopus CAIM 0.15 laevis Lamin A Human, Xenopus CSIM 0.20 laevis Retinal cGMP Bovine CCVQ (SEQ ID NO:13) 0.35 Phosphodies- terase, α-subunit *ras1 S. cereviscia CIIC (SEQ ID NO:14) 0.35 *ras2 S. cereviscia CIIS (SEQ ID NO:15) 0.35 *γ-Subunit of Bovine CVIS (SEQ ID NO:16) 1.0 transducin P21 H-ras Chicken CVIS (SEQ ID NO:16) 1.0 p21 H-ras Human, rat CVLS (SEQ ID NO:17) 3.0 *a-Mating S. cereviscia CVIA (SEQ ID NO:18) 5.0 factor rap2b Human CVIL 11 Dras Dictostelium CLIL (SEQ ID NO:20) 17 rapla/krevl Human CLLL (SEQ ID NO:21) 22 *Mating factor R. Taruloide CTVA (SEQ ID NO:22) 30 γ-Subunit of Bovine CAIL (SEQ ID NO:51) 100 G protein HMG CoA S. cereviscia CIKS (SEQ ID NO:52) >100 reductase-1
[0165] 3. Discussion
[0166] The current data extend the observations on the p21 ras farnesyl:protein transferase set forth in Example I, and further indicate that the recognition site for this enzyme is restricted to four amino acids of the Cys-A1-A2-X type. As a reference sequence for these studies, the peptide CVIM was used. This peptide inhibited the farnesyl:protein transferase by 50% at a concentration of 0.15 μM. Substitution of various amino acids into this framework yielded peptides that gave 50% inhibitions at a spectrum of concentrations ranging from 0.025 AM (CVFM) to greater than 50 μM (FIG. 14).
[0167] In general, the highest inhibitory activities were achieved when the A1 and A2 positions were occupied with nonpolar aliphatic or aromatic amino acids. This stringency was more severe at the A2 than at the A1 position. Thus, peptides containing lysine or glutamic acid at the A1 position gave 50% inhibition at 0.7 and 1.5 μM, respectively. When these two residues were inserted at the A2 position, the affinity for the enzyme declined by more than 50-fold. Glycine and proline lowered inhibitory activity moderately at the A1 position (50% inhibition at 4 and 8 μM) and somewhat-more severely at the A2 position (8 and 20 μM).
[0168] The X position showed the highest stringency. In the context of CVIx, methionine was the preferred residue but phenylalanine and serine were tolerated with only modest losses in activity (0.5 and 1 μM, respectively). Aliphatic resides and proline were disruptive at this position, with 50% inhibitions in the range of 5-11 μM. Glutamic acid, lysine, and glycine were not tolerated at all; 50% inhibition required concentrations above 40 μM.
[0169] A study of tetrapeptides corresponding to the COOH-termini of known proteins (Table III) gave results that were generally in keeping with those obtained with the substituted CVIM peptides. They provided the additional information that glutamine and cysteine are well tolerated at the X position (CCVQ (SEQ ID NO: 13) and CIIC (SEQ ID NO: 14)). All of the proteins that are known to be farnesylated in intact cells (indicated by the asterisks in Table III) followed the rules outlined above, and all inhibited farnesylation at relatively low concentrations (5 μM or below) with the exception of the CTVA (SEQ ID NO: 22) sequence, which is found in the mating factor of R. toruloides (19). This peptide inhibited the rat brain farnesyl:protein transferase by 50% only at the high concentrations of 30 μM. It is likely that the farnesyl:protein transferase in this fungal species has a different specificity than that of the rat brain.
[0170] The peptide CAIL (SEQ ID NO: 15), which corresponds to the COOH-terminus of the y-subunit of bovine brain G proteins (20,21), did not compete efficiently with p21 H-ras for farnesylation (Table III). A 50% inhibition at the highest concentration tested (100 μM) was observed. The inhibitory activity was lower than that of CVIL (SEQ ID NO: 19) (12 μM) or CAIM (0.15 μM). Thus, the combination of alanine at the A1 position and leucine at the X position is more detrimental than either single substitution. This finding is particularly relevant since the-gamma subunit of G proteins from human brain (22) and rat PC12 cells (23) have been shown to contain a geranylgeranyl rather than a farnesyl. These findings suggest the existence of a separate geranylgeranyl transferase that favors CAIL (SEQ ID NO: 5 1) and perhaps other related sequences.
[0171] The studies with the biotinyated heptapeptide (FIG. 12B) confirm that at least some of the short peptides act as substrates for the enzyme. The saturation curves relating reaction velocity to the concentration of either p21 H-ras or the biotinylated heptapeptide are complex and sigmoidal. The inhibition curves with the various peptides differ from classic competitive inhibition curves. Finally, as mentioned in Example I, the maximal velocity of the purified enzyme is relatively low. These findings suggest that the binding of the peptides to the enzyme is not a simple equilibrium reaction. Rather, there may be a slow binding that requires conformational change.
[0172] The observation that the A1 position shows a relaxed amino acid specificity suggests that the residue at this position may not contact the farnesyl:transferase directly. Rather, the contacts may involve only the cysteine and the residues at the A2 and X positions. A working model for the active site of the farnesyl-protein transferase places the peptide substrate in an extended conformation with a largely hydrophobic pocket of the enzyme interacting with the X group of the CAAX-containing substrate.
EXAMPLE III
Recombinant Cloning of the Farnesyl:Protein Transferase Subunit Genes
[0173] This example demonstrates an approach which the inventors propose may be employed for the recombinant cloning of one or both of the farnesyl:protein transferase subunits. As will be appreciated by those of skill in the art from the following description, the preferred approach recommended by the inventors involves the application of the peptide sequence information set forth above to prepare specific primers for PCR-based sequencing, which sequences are then used for the construction of probes for screening. The specific primers proposed for use are set forth below, with reference to FIGS. 16 and 17.
[0174] A. General Methods
[0175] The inventors propose that general molecular biology techniques may be employed in connection with the cloning reactions described below (24). Where desired, cDNA clones may be subcloned into M13 and pUC vectors and sequenced by the dideoxy chain termination method (25) using the M13 universal sequencing primer or gene specific internal primers. Sequencing reactions are preferably performed using a modified bacteriophage T7 DNA polymerase (26) with 35 S-labeled nucleotides, or Taq polymerase with fluorescently labeled nucleotides on an Applied Biosystems Model 370A DNA Sequencer.
[0176] For the isolation of total RNA from rat tissues, the inventors prefer to employ the guanidinium. thiocyanate/CsCl centrifugation procedure (27). For the isolation of RNA from cell lines, the guanidinium HCl method is generally preferred (28). The isolation of poly A + RNA by oligo(dT)-cellulose chromatography is preferably by the procedure of Aviv and Leder (29). Northern blot hybridization using single-stranded 32P-labeled probes is generally carried out as described by Lehrman et al. (30).
[0177] B. cDNA Libraries
[0178] For the construction of a cDNA libraries, the inventors propose to employ poly A + RNA from rat brain, PC12 and/or KNRK, cells. These cells are preferred in that they are believed to be rich in farnesyl:protein transferase mRNA. Although numerous convenient methods are known for the construction of cDNA libraries, the inventors believe that the use of a cDNA synthesis kit, e.g., from Invitrogen, is the most convenient. The cDNA itself is preferably prepared using both oligo(dT)- and random hexamer-primed cDNA, and then ligated to adapters, e.g., EcoR1/Not1 adapters. Next, it will generally be desirable to isolate cDNAs greater than 1 kb in size, e.g., by fractionation on a 1% agarose gel, prior to ligation to EcoR1-cleaved λgt10 DNA (Stratagene), in order to complete the construction of the cDNA-containing vectors for library preparation.
[0179] After in vitro packaging of the recombinant lambda phage with a DNA packaging extract (Stratagene), phage may be plated out on host strain Escherichia coli C600 hfl-cells. Typically, it will be desirable to screen approximately 1×10 6 plaques from the random hexamer-primer rat brain library. To carry out the screening, duplicate filters are hybridized in 6×SSC at 37° C. with about 1×10 6 cpm/ml of the appropriate 32 p-labeled oligonucleotide probe. The polymeras e chain reaction may be used to obtain an unambiguous probe for screening of the cDNA library, as well as to characterize positive λ clones, as discussed below.
[0180] The filters are washed in 6×SSC (1×SSC=150 mM NaCl, 15 mM sodium citrate, pH7) and 0.2% SDS at room temperature. DNA from colonies which remain positive after a second round of screening are purified and subcloned into a vector that is suitable for sequencing and restriction mapping, such as a bacteriophage M13 and/or pBluescript vector.
[0181] C. Polymerase Chain Reaction
[0182] 1. α Subunit
[0183] To derive a sequence for constructing an appropriate probe, rat genomic DNA may be used as a template for PCR as described by Saiki et al. (31) and Lee et al. (32). The approach is to sequence a portion of the a subunit gene through-the use of appropriate PCR primers (based on a consideration of the peptide sequences shown in Table 1). The inventors propose to use primers that are synthesized based on the NH2- and COOH-terminal sequences of peptide 2 (see Table I above), and which include the degenerate inosine base (see FIG. 16). PCR primers are end-labeled with [γ- 32 p]ATP. The resultant amplified DNA fragment is then eluted and sequenced, e.g., by the Maxam-Gilbert technique (33). Translation of the nucleotide sequence between two primers should give the expected amino acid sequence of peptide 2. From this information, one may then synthesize an oligonucleotide probe that will hybridize with the region corresponding to the peptide 2 coding region, for direct screening of the library.
[0184] To characterize hybridizing λgt10 clones, plaques are eluted in 0.2 ml SM buffer (100 mM NaCl, 8 mM MgSO4, 50 mM Tris-HCl pH7.5, and 0.01% (w/v) gelatin). A primer corresponding to the right arm or left arm of λgt10 sequences flanking the unique EcoR1 site may be used in combination with a primer derived from the cDNA sequence in order to conduct a PCR amplification reaction, which may be carried out by the procedure of Saiki et al. (31). PCR products may then be analyzed on an agarose gel and the clone containing the longest insert selected and purified for further characterization.
[0185] 2. β Subunit
[0186] As with the α subunit cloning, the polymerase chain reaction is used to obtain an unambiguous sequence for the peptide and to characterize positive λ clones. To derive an unambiguous sequences for the peptide, rat genomic DNA is again used as a template for PCR. In this case, though, primers are synthesized based on the NH2- and COOH-terminal sequences of peptide 7 from Table I, and include the degenerate base inosine (see FIG. 17). As above, one of the PCR primers is end-labeled with [γ- 32 P]ATP. The resultant amplified DNA fragment is then eluted from acrylamide gel and sequenced. Translation of the nucleotide sequence between two primers should give the expected amino acid sequence derived from peptide. From this information, one will desire to synthesize an oligonucleotide primer for use as a hybridization probe.
[0187] D. 5′ and 3′ End Amplification
[0188] If one obtains a clone that is less than full length, it will, of course, be important to obtain a clone which comprises the missing sequences. This can be done through the preparation of either a 5′ or 3′ extended clone, depending on what is needed. To obtain an extended clone, the general procedures of Frohman et al. (34) are preferably followed that involve a combination of reverse transcription, tailing with terminal deoxytransferase and, finally, PCR.
[0189] 1. 5′-End Amplification of cDNA End
[0190] Where the clone is deficient in its 5′-end, one will typically desire to carry out an 5′-end amplification, which may be carried out generally as described by Frohman et al. (34). In general, first strand cDNA is generated by reverse transcription of polyA + RNA from, e.g., either KNRK, rat brain or PC12 cells, pretreated with methyl mercury and primed with a 5′-end primer derived from the longest cDNA then available. Thus, in the case of the a subunit, one may desire to employ specific primer 1 (TGCAGTGATGTAGTTCAT), which is complementary to amino acids located towards the amino terminal of the alpha subunit.
[0191] Excess primer is removed by, e.g., application to a Amicon Centricon 100 spin filter and the first strand cDNA tailed with dATP using terminal deoxynucleotidetransferase (BRL). The reaction mixture is typically diluted to 500 μl in TE and 1- to 10-μl aliquots are used for amplification with about 10 pmol of a (dT)17-adaptor oligonucleotide which serves to prime off of the dA tail added at the 5′ end of the cDNA, and about 25 pmol of a second specific primer which serves to narrow the amplification to cDNAs derived from the farnesyl-protein transferase mRNA, in 50 μl of PCR cocktail. In the case of the a subunit, the inventors propose to use the (dT) 17-adaptor primer, GACTCGAGTCGACATCGA(T)17, adaptor primer (GACTCGAGTCGACATCAG) and specific primer 2 (AGCGACCTCAAGAGAACT) as the second specific primer.
[0192] The mixture is denatured (5 min, 95° C.), annealed at 52-58° C., Taq DNA polymerase added, and extended at 72° C. for 40 min. Using a DNA thermal cycler (Perkin-Elmer-Cetus), it is preferable to carry out at least 40 cycles of amplification (94° C., 40 sec; 52-58° C., 2 min; 72° C., 3 min) followed by a 15 min final extension at 72° C. Amplified PCR products may be analyzed by Southern gel analysis. The hybridizing DNA fragments are isolated and used as templates for a second PCR amplification as described above, except for the substitution of about 25 pmol of an additional specific primer 3 (such as ATGCCACACCGTATAGTT in the case of subunit α), which further limits the amplification to templatescorresponding to the farnesyl:protein transferase cDNA. The reamplified DNA may be reprobed by Southern analysis, isolated, treated with T4 polynucleotide kinase, and cleaved with PstI for subcloning to M13 and sequencing.
[0193] 2. 3′-End Amplification of cDNAs
[0194] Where resultant clones are found to be deficient in their 3′ sequence, one will desire to carry out 3′-end amplification, such as described by Frohman et al. (34). For reverse transcription, KNRK cell poly(A) + RNA may be used as a template and primed with a (dT)17-adaptor. In a 20 μl reaction mixture, 1 μg poly(A) + RNA, 0.5 μg (dT)17adaptor and 100 units reverse transcriptase (BRL) are incubated at 3 7° C. for 1 hr. Reverse transcribed cDNA is diluted 50 fold with TE (10 mM Tris-HCl, pH8.0 and 1 mM EDTA) for PCR amplification.
[0195] As an example, in the case of, e.g., the β subunit, 10 μl of diluted cDNA and 25 pmole each of adaptor primer and 17-base primer 1 (FIG. 17) are boiled, after which PCR is carried out 40 cycles of amplification (94° C., 40 sec; 58° C., 2 min; 72° C., 3 min) with TaqI polymerase. A second round of PCR is carried out as described above, except that specific primer 2 (FIG. 17) and the adapter primer are employed. Amplified PCR products are analyzed on an agarose gel, transferred to a nylon membrane and probed with 32 P-labeled primer 2 (FIG. 17). The hybridizing DNA fragment is eluted, extracted with phenol/chloroform, and used as a template for a second round PCR amplification. This amplification—is carried out in same cycles as described above, except that 25 pmole each of adaptor and primer 2 is preferably substituted for primers. This reamplified DNA is then purified, cleaved with RsaI or TaqI and subcloned into, e.g., M13 vectors for sequencing.
[0196] While the compositions and methods of this invention have been described in terms of preferred embodiments, it will be apparent to those of skill in the art that variations may be applied to the composition, methods and in the steps or in the sequence of steps of the method described herein without departing from the concept, spirit and scope of the invention. More specifically, it will be apparent that certain agents which are both chemically and physiologically related may be substituted for the agents described herein while the same or similar results would be achieved. All such similar substitutes and modifications apparent to those skilled in the art are deemed to be within the spirit, scope and concept of the invention as defined by the appended claims.
REFERENCES
[0197] The references listed below are incorporated herein by reference to the extent that they supplement, explain, provide a background for or teach methodology, techniques and/or compositions employed herein.
[0198] 1. Bos, J. (1989), “ras Oncogenes in Human Cancer: A Review”, Cancer Res., 49:4682-4689.
[0199] 2. Barbacid (1987), “ras Genes”, Ann. Rev. Biochem., 56:779-827.
[0200] 3. Hancock, J. F., et al. (1989), “All ras proteins are polyisoprenylated but only some are palmitoylated.”, Cell, 57:1167-1177.
[0201] 4. Scheler, W. R. et al. (1989), Science. 248:379-385.
[0202] 5. Gibbs, J. B., et al. (1989), “The ras oncogene—an important regulatory element in lower eucaryotic organisms.”, Micro Rev. 53:171-185.
[0203] 6. Casey, P. J., et al. (1989), Ilp21ras is modified by a farnesyl isoprenoid,” Proc. Natl. Acad. Sci. U.S.A.,. 86:8323-8327.
[0204] 7. Kamiya, Y., et al. (1978), “Structure of rhodotorucine A, a novel lipopeptide, inducing mating tube formation in Rhodosporidium toruloides.”, Biochem. Biophys. Res. Comm., 31:10771083.
[0205] 8. Kamiya, Y., et al. (1979), N. Agric. Biol. Chem. 43:1049-1053.
[0206] 9. Sakagami, Y., et al. (1981), “Peptidal sex hormones inducing conjugation tube formation in compatible mating type cells of Tremella - mesenterica.”, Science,=: 1525-1527.
[0207] 10. Gutierrez, L., et al. (1989), “Post-translational processing of p21ras is two-step and involves carboxy-methylation and carboxy-terminal proteolysis.”, Embo J, Q: 1093-1098.
[0208] 11. Lowry, D. R. et al. (1989), Nature, 341: 384-385.
[0209] 12. Clarke, E., et al. (1988), “Posttran-slational modification of the Ha-ras oncogene protein: evidence for a third class of protein carboxyl methyltransferas es.”, Proc Natl. Acad. Sci, U.S.A. 1 !˜:4643-4647.
[0210] 13, Davisson, V. J., et al. (1986), “Phosphorylation of isoprenoid alcohols.”, J. Org. Chem., 51:4768-4779.
[0211] 14. Feig, L. A., et al. (1986), “Isolation of ras GTPbinding mutants using an in situ colony-binding assay.”, Proc. Natl. Acad. Sci. U.S.A., 83:46074611.
[0212] 15. Farnsworth, D. C., et al. (1989), “Human lamin B contains a farnesylated cysteine residue.”, J. Biol. Chem., 264:20422-20429.
[0213] 16. Laemmli, U. K. (1970), “Cleavage of structural proteins during the assembly of the head of bacteriophage T4.11, Nature, 227:680-685.
[0214] 17. Lowry, O. H., et al. (1951), J. Biol. Chem., 193:265275.
[0215] 18. Stewart, J. M. et al. (1984), Solid Phase Peptide Svnthesi˜i, 2nd ed., Pierce Chemical Co., Rockford, Ill.
[0216] 19. Akada, R., et al. (1989), Mol. Cell. Biol. 2:34913498.
[0217] 20. Gautam, N., et al. (1989), Science. 244:971-974.
[0218] 21. Robishaw, J. D., et al. (1989), J. Biol, Chem. 2 §A:15758-15761.
[0219] 22. Yamane, H. K., et al. (1990), Proc, Natl. Acad. Sci. USA, 87:5868-5872.
[0220] 23. Mumby, S. M., et al. (1990), Proc. Natl, Acad. Sci. USA, 87:5873-5877.
[0221] 24. Sambrook, J., et al. (1989), Molecular Cloning, A Laboratory Manual, Cold Spring Harbor Laboratory, Cold Spring Harbor, N.Y.
[0222] 25. Sanger, F., et al. (1977), Prog Natl - Acad, Sci. USA, 74:5463-5467
[0223] 26. Tabor, S., et al. (1987), Proc Natl. Acad. Sci. USA, 844767-4771
[0224] 27. Glisin, V., et al. (1974), Biochemistry, 11:26332640
[0225] 28. Chirgwin, J. M., et al. (1979), Biochemistry, la: 5294-5303
[0226] 29. Aviv, H., et al. (1972), Proc. Nati. Acad. Sci. USA, 69:1408-1412
[0227] 30. Lehrman, M. A., et al. (1987), J. Biol. Chem., 2 U:3354-3361
[0228] 31. Saiki, R. K., et al. (1988), Science 239:487-491
[0229] 32. Lee, C. C., et al. (1988), Science, 239:1288-1291
[0230] 33. Maxam, A. M., et al. (1980), Methods Enzymol., §L!˜: 499-560
[0231] [0231] 34 . Frohman, M. A., et al. (1988), Proc. Natl. Acad. Sci. USA, 85:8998-9002
1
52
25 amino acids
amino acid
single
linear
peptide
1
Arg Ala Glu Trp Ala Asp Ile Asp Pro Val Pro Gln Asn Asp Gly Pro
1 5 10 15
Ser Pro Val Val Gln Ile Ile Tyr Ser
20 25
16 amino acids
amino acid
single
linear
peptide
2
Asp Ala Ile Glu Leu Asn Ala Ala Asn Tyr Thr Val Trp His Phe Arg
1 5 10 15
8 amino acids
amino acid
single
linear
peptide
3
Asn Tyr Gln Val Trp His His Arg
1 5
12 amino acids
amino acid
single
linear
peptide
4
His Phe Val Ile Ser Asn Thr Thr Gly Tyr Ser Asp
1 5 10
7 amino acids
amino acid
single
linear
peptide
5
Val Leu Val Glu Trp Leu Lys
1 5
13 amino acids
amino acid
single
linear
peptide
6
Leu Val Pro His Asn Glu Ser Ala Trp Asn Tyr Leu Lys
1 5 10
20 amino acids
amino acid
single
linear
peptide
7
Ala Tyr Cys Ala Ala Ser Val Ala Ser Leu Thr Asn Ile Ile Thr Pro
1 5 10 15
Asp Leu Phe Glu
20
8 amino acids
amino acid
single
linear
peptide
8
Leu Gln Tyr Leu Ser Ile Ala Gln
1 5
7 amino acids
amino acid
single
linear
peptide
9
Leu Leu Gln Trp Val Thr Ser
1 5
23 amino acids
amino acid
single
linear
peptide
10
Ile Gln Ala Thr Thr His Phe Leu Gln Lys Pro Val Pro Gly Phe Glu
1 5 10 15
Glu Cys Glu Asp Ala Val Thr
20
9 amino acids
amino acid
single
linear
peptide
11
Ile Gln Glu Val Phe Ser Ser Tyr Lys
1 5
4 amino acids
amino acid
single
linear
peptide
12
Cys Val Leu Met
1
4 amino acids
amino acid
single
linear
peptide
13
Cys Cys Val Gln
1
4 amino acids
amino acid
single
linear
peptide
14
Cys Ile Ile Cys
1
4 amino acids
amino acid
single
linear
peptide
15
Cys Ile Ile Ser
1
4 amino acids
amino acid
single
linear
peptide
16
Cys Val Ile Ser
1
4 amino acids
amino acid
single
linear
peptide
17
Cys Val Leu Ser
1
4 amino acids
amino acid
single
linear
peptide
18
Cys Val Ile Ala
1
4 amino acids
amino acid
single
linear
peptide
19
Cys Val Ile Leu
1
4 amino acids
amino acid
single
linear
peptide
20
Cys Leu Ile Leu
1
4 amino acids
amino acid
single
linear
peptide
21
Cys Leu Leu Leu
1
4 amino acids
amino acid
single
linear
peptide
22
Cys Thr Val Ala
1
4 amino acids
amino acid
single
linear
peptide
23
Cys Val Ala Met
1
4 amino acids
amino acid
single
linear
peptide
24
Cys Lys Ile Met
1
4 amino acids
amino acid
single
linear
peptide
25
Cys Leu Ile Met
1
4 amino acids
amino acid
single
linear
peptide
26
Cys Val Leu Met
1
4 amino acids
amino acid
single
linear
peptide
27
Cys Phe Ile Met
1
4 amino acids
amino acid
single
linear
peptide
28
Cys Val Phe Met
1
4 amino acids
amino acid
single
linear
peptide
29
Cys Val Ile Phe
1
4 amino acids
amino acid
single
linear
peptide
30
Cys Glu Ile Met
1
4 amino acids
amino acid
single
linear
peptide
31
Cys Gly Ile Met
1
4 amino acids
amino acid
single
linear
peptide
32
Cys Pro Ile Met
1
4 amino acids
amino acid
single
linear
peptide
33
Cys Val Tyr Met
1
4 amino acids
amino acid
single
linear
peptide
34
Cys Val Thr Met
1
4 amino acids
amino acid
single
linear
peptide
35
Cys Val Pro Met
1
4 amino acids
amino acid
single
linear
peptide
36
Cys Val Ser Met
1
4 amino acids
amino acid
single
linear
peptide
37
Cys Val Ile Phe
1
4 amino acids
amino acid
single
linear
peptide
38
Cys Val Ile Val
1
4 amino acids
amino acid
single
linear
peptide
39
Cys Val Ile Pro
1
4 amino acids
amino acid
single
linear
peptide
40
Cys Val Ile Ile
1
7 amino acids
amino acid
single
linear
peptide
41
Lys Thr Ser Cys Val Ile Met
1 5
4 amino acids
amino acid
single
linear
peptide
42
Ser Val Ile Met
1
36 base pairs
nucleic acid
single
linear
DNA
43
GAYGCNATNG ARYTAAACGC AGCCAACTAT ACGGTC 36
16 amino acids
amino acid
single
linear
peptide
44
Asp Ala Ile Glu Leu Asn Ala Ala Asn Tyr Thr Val Trp His Phe Glu
1 5 10 15
14 base pairs
nucleic acid
single
linear
DNA
45
CKRAARTGCC ANAC 14
38 base pairs
nucleic acid
single
linear
DNA
46
TANGAGTTAA ACGCAGCCAA CTATACGGTC TGGCACTT 38
16 base pairs
nucleic acid
single
linear
DNA
47
GCGTACTGTG CGGCTC 16
35 base pairs
nucleic acid
single
linear
DNA
48
GCNTAYTGYG CNGCCTCAGT GCCTCTCTCA CCAAC 35
14 base pairs
nucleic acid
single
linear
DNA
49
GGNGTRATNA TRTT 14
37 base pairs
nucleic acid
single
linear
DNA
50
TACTGTGCCT CAGTAGCCTC TCTCACCAAC ATNATCA 37
4 amino acids
amino acid
single
linear
peptide
51
Cys Ala Ile Leu
1
4 amino acids
amino acid
single
linear
peptide
52
Cys Ile Lys Ser
1
|
Disclosed are methods and compositions for the identification, characterization and inhibition of farnesyl protein transferases, enzymes involved in the farnesylation of various cellular proteins, including cancer related ras proteins such as p21 ras . One farnesyl protein transferase which is disclosed herein exhibits a molecular weight of between about 70,000 and about 100,000 upon gel exclusion chromatography. The enzyme appears to comprise one or two subunits of approximately 50 kDa each. Methods are disclosed for assay and purification of the enzyme, as well as procedures for using the purified enzyme in screening protocols for the identification of possible anticancer agents which inhibit the enzyme and thereby prevent expression of proteins such as p21 ras . Also disclosed is a families of compounds which act either as false substrates for the enzyme or as pure inhibitors and can therefore be employed for inhibition of the enzyme. The most potent inhibitors are ones in which phenylalanine occurs at the third position of a tetrapeptide whose amino terminus is cysteine.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to the field of apparatus and methods for shielding the body from hostile gunshot activity or bomb explosions. More particularly, this invention relates to an apparatus and method for the automated introduction of a protective, inflatable shield between the concussive force of a bomb blast or the impact energy of a projectile, and the body of the person at which it is directed.
2. Description of the Related Art
Many different approaches to the protection of personnel from life-threatening attacks exist. Examples of such approaches include bullet-proof glass, concrete and steel building structures, armored cars, bullet-proof jackets, and others. The particular avenue taken depends on whether the person is stationary, located in a vehicle, located within a building, or is required to maintain mobility outside the confines of any specific stationary structure.
Many law enforcement agencies have the designated task of protecting public figures from terroristic attacks. Most often this protection is achieved through some combination of passive personnel armor (e.g., previously mentioned bullet-proof vests, etc.), identification and control of potential sniper vantage points, and passive protection such as shields, bullet-proof glass, armor plates, and other devices mentioned previously. Since public figures often desire unrestricted access to the public and commensurate high visibility, traditional ballistic screens and placement of protective personnel in close proximity are often not practical or effective. Therefore, a need exists for an unobtrusive, reactive device that provides adequate ballistic protection. This need can be satisfied by detecting an incoming pistol or rifle ballistic projectile, discriminating that projectile from other potential airborne particles or objects, and activation/deployment of a protective device, prior to the arrival of the projectile at the designated target.
A search of the prior art did not disclose any patents that read directly on the claims of the instant invention, however, the following U.S. patents were considered related:
______________________________________U.S. PAT. NO. INVENTOR ISSUE DATE______________________________________3,861,710 Okubo January 21, 19754,856,436 Campbell August 15, 19895,327,811 Price et al. July 12, 19944,782,735 Mui et al. November 8, 1988______________________________________
Okubo discloses a vehicular safety system having an obstacle detector and an impact detector. These detectors are coupled to a single, inflatable air bag which can be deployed by the activity of either detector. One of the detectors is a Doppler radar for predicting collision with the vehicle, and the other senses impact at the moment it occurs between the vehicle and another object. The air bag is incrementally inflated by signals emanating from either of these detectors, being interposed between the occupants of the vehicle and destructive interior vehicle surfaces.
Campbell discloses an invention to automatically cover electronic equipment for protection from automatic sprinkler systems and other sources of water during the activation of a fire alarm. The cover is deployed by the automatic expansion of spring-loaded telescopic arms which respond to a manual or electronic alarm signal. The cover can be manually reset by rotating and compressing the telescopic arm system to replace the cover into its enclosure. The object of this invention is to protect expensive equipment from fire, smoke, and water damage resulting from fire in the immediate vicinity of the equipment.
Price et al. describes an adaptable bullet-proof vest which makes use of SPECTRA® materials components. The body armor vest consists of several pieces of SPECTRA SHIELD® material (consisting of resin bonded fibers) sewn into woven ballistic SPECTRA® fiber fabric. This combination of woven and non-woven SPECTRA® components creates increased levels of protection for a bullet-proof vest, while simultaneously reducing weight and bulk.
Finally, Mui et al. speaks to a bullet-proof protection apparatus consisting of a full-length, inflatable body shield which can be carried in a portable fashion. The shield consists of an encased, inflatable mattress which is deployed by manual activation of a pressurized gas source. This invention anticipates the use, storage, and re-use of the mattress.
SUMMARY OF THE INVENTION
Public officials, military personnel, and civilian leaders are often exposed to a wide range of physical threats. While the related devices described in the previous section are somewhat effective in detecting destructive terroristic activity, each approach has its own limitations. The most likely threat areas currently encountered are those provided by high explosives, detonated within a building or at some short distance from a building, and small arms fire (e.g. an assassination attempt). The invention herein described incorporates a combination of systems to produce a robust, unobtrusive, and easily installed apparatus which acts to defeat these threats after detonation of a bomb, or discharge of a weapon.
The present invention is a reactive personnel protection system which acts by detecting the presence of a destructive force or object and interposing a protective shield between personnel under attack and the force in an almost instantaneous fashion. Several embodiments of the invention are provided, namely, detection of an incoming small arms projectile, or detection of a concussive blast triggered by a bomb explosion. In either case, a triggering mechanism is provided to rapidly inflate an air bag fabricated from SPECTRA®, KEVLAR®, or similar materials. This air bag is rapidly inflated and interposed between the projectile or concussive force and the person to be protected so as to either deflect the projectile or reduce the effects of the concussive force.
In the case of projectile detection and protection, a radar-based bullet detection system with anti-jamming electronics is used to detect the presence of an incoming small arms projectile and determine its path of travel. A bi-static radar system is used tech detect the Doppler shift signature of any detected objects to reliably determine the presence of a bullet, and discriminate between the bullet and any other rapidly moving object in the vicinity. Additionally, signal processing circuitry and algorithms are used to help differentiate between projectiles and noise or other extraneous signals to prevent false alarms. Once the presence of a ballistic object is confirmed, a control unit activates a gas generation device, which in turn rapidly inflates an anti-ballistic air bag.
In the case of a concussive blast triggered by a bomb explosion, the detection mechanism consists of blast pressure gauges or other devices which are sensitive to rapid changes in acceleration (if mounted to a physical structure), and/or air pressure (e.g. the concussive wave front which accompanies an explosion). These blast pressure gauges are placed at a suitable distance from, and on a periphery around, the personnel to be protected. Other devices, such as magnetostrictive transducers, ultrasonic transducers, accelerometers, and other mechanical and/or electro-mechanical sensors can also be applied to sense the occurrence of a concussive explosion. Signal analysis hardware is used to discriminate and verify the presence of a concussive blast wave front. Redundant verification is also provided, to minimize the likelihood of accidental deployment. Further, anti-jamming electronics are used to provide immunity to electronic noise which may otherwise render the system inoperable. Of course, such redundant verification and anti-jamming electronic systems are also applied to the aforementioned ballistic object detection system.
In the case of either detection system, any type of destructive force confirmation signal resulting therefrom is used to bring about the rapid inflation of an anti-ballistic air bag. This air bag is specially fabricated from ultra-high molecular weight polyethylene, such as SPECTRA®, KEVLAR®, or similar materials which can be used to redirect or lessen the approach of an unwanted destructive object or force. The overall size of the inflated bag depends upon the desired level of protection and the time needed to deploy the bag. Vents are incorporated into the bag to control stress in the bag material during deployment, and also to determine the length of deployment time. Prior to deployment, the air bag is housed in an unobtrusive container having a metallic base plate, and held in place with a pinching bar. The container has a frangible surface through which the air bag can be rapidly deployed.
A gas generation system (also housed in the container holding the air bag) is used to fill and deploy the anti-ballistic air bag. Multiple air bags and/or multiple generators may also be employed, depending on the particular system protection requirements.
It should be noted that the present invention is distinctly different from existing sniper detection systems, which are designed to locate the source of a ballistic projectile after the target has been hit, so that return fire or other offensive actions can be taken. These systems typically make use of Doppler radar or acoustic technology, and do not incorporate any proactive, protective capabilities. The present invention, however, is designed to detect the presence of the projectile during its flight, and before impact.
Therefore, the reactive personnel protection system of thus present invention makes use of a radar-based bullet detection system, or a concussive blast detection system, which provides an inflation signal to an anti-ballistic air bag interposed between the approach of an unwanted destructive object and the personnel to be protected. The signal denoting approach of a destructive force is analyzed and confirmed to make sure that it is properly differentiated from noise or other extraneous signals which may be present. The detection system further includes anti-jamming circuitry for electronic noise immunity and redundant verification to help prevent spurious activation of the air bag.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a perspective view of the explosion protection embodiment of the present invention before air bag deployment.
FIG. 1B is a perspective view of the explosion protection embodiment of the present invention after detection of an explosion.
FIG. 2A is a perspective view of the ballistic protection embodiment of the present invention before air bag deployment.
FIG. 2B is a perspective view of the ballistic protection embodiment of the present invention after detection of a ballistic projectile.
FIG. 3 is a three-view depiction of a deployed air bag.
FIG. 4 is a schematic block diagram of a bi-static radar ballistic projectile detection system.
FIG. 5 is a schematic diagram for Doppler-shifted tone detection.
FIG. 6 is a schematic diagram of a gas-generator squib ignition circuit.
DETAILED DESCRIPTION OF THE INVENTION
Turning now to FIG. 1A, a perspective view of the explosion protection embodiment of the present invention can be seen. This view depicts the state of the apparatus of the present invention prior to detection of a concussive (blast) pressure wave. Person (100) is shown seated in a room (90) having doorway opening (80). Pressure wave sensor (50) is placed at some distance away from air bag enclosure (20) sufficient to ensure that pressure wave (70) emanating from explosion (60) will not reach person (100) before the protective element of reactive personnel protection system (10) can be fully activated.
Referring now to FIG. 1B, the deployed condition of the present invention can be seen. Since sound normally travels at a speed of 1,025 ft./sec. at sea level, and it may take air bag (25) approximately 30 msec. to deploy, the minimum distance that sensor (50) should be placed from enclosure (20), which houses air bag (25), is 50 ft. This gives approximately 20 msec. for the control unit (40) to process the signal provided by sensor (50) via sensor output conduit (55), confirm that the signal indicates the presence of a destructive pressure wave (70), and initiate deployment of air bag (25) via trigger output (30).
Turning now to FIG. 2A, a perspective view of the ballistic protection embodiment of the present invention before the protective element has been deployed can be seen. It has been determined that the best method for detecting the presence of a bullet (130) is radar technology; acoustic-based systems are less reliable and can be defeated by silencers applied to small arms. Doppler radar systems have been used successfully as velocimeters in ballistic applications, and in general, Doppler radar system perform well in noisy and/or geometrically complex environments. The present invention incorporates a bi-static configuration of Doppler radar in which a separate illuminator or transmitter (110) is located at some distance from passive receiver (120). The sensor output conduit (55) from receiver (120) is monitored by control unit (40) and, after suitable analysis and discrimination, trigger output (30) is activated whenever the presence of bullet (130) is detected and confirmed. Trigger output (30) is sent to enclosure (20), which houses air bag (25) (not shown in this figure).
Turning now to FIG. 2B, the deployed condition of the ballistic protection embodiment of the present invention can be seen. Initial trajectory (140) of bullet (130) has been detected by receiver (120) and air bag (25) has been deployed from enclosure (20). It should be noted that several enclosures (20), housing multiple air bags (25), can also be employed in this embodiment of the invention. Once control unit (40) has determined initial trajectory (140) of bullet (130), then the appropriate air bag (25) can be deployed via trigger output (30). This figure also illustrates intermediate trajectory (150) of bullet (130), after it is redirected by encountering front surface (220) of air bag (25). Bullet (130) is further redirected by rear surface (230) to follow exit trajectory (160). As mentioned previously, air bag (25) is deployed by control unit (40) so as to interpose a protective shield between the initial trajectory (140) of bullet (130) and person (100).
Lightweight materials, such as DuPont's KEVLAR® and Allied Signal's SPECTRA®, are available as woven fabrics to provide proper anti-ballistic air bag protection. These materials can be sewn or configured in many ways to accommodate ballistic protection applications; in the present invention, the selected material is formed into air bags similar to those found in automobiles, but of larger size and thickness. The strength to weight ratio of these anti-ballistic fabrics are among the highest available, either man-made or natural.
Turning now to FIG. 3, a three-view depiction of the deployed air bag (25) of the present invention can be seen. After detection and confirmation of a concussive shock wave or ballistic projectile, an activation signal is sent to gas generator (210) so that air bag (25) is inflated within approximately 20-30 msec of receipt. Enclosure (20) has frangible upper surface (260) through which air bag (25) emerges when inflated by gas generator (210). Front surface (220), rear surface (230), and top surface (245) of air bag (25) are made from SPECTRA®, KEVLAR®, or other similar ultra-high molecular weight polyethylene fabric. Using such construction results in a type of spaced-plate armor system. That is, for a given level of protection, such a multi-plate system results in a lighter protective element, per unit area, than using a single, equivalent layer of the same material.
The inflation of air bag (25) by way of gas generator (210) is also controlled using vents 9240) and cross-ties (200). Air bag (25) should optimally be configured to remain effectively inflated and in place for at least two seconds.
The effectiveness of the anti-ballistic air bag (25) in stopping a bullet is a function of the thicknesses of the front surface (220) and rear surface (230), as well as the distance between them. The mechanical advantage of this spaced-plate system lies in the fact that the front surface (220) slows, deforms, and re-directs the projectile as it passes through; the slower, tumbling projectile is then either halted or further re-directed by the rear surface (230) of air bag (25).
In the present invention, any material of sufficient strength and toughness to significantly re-direct a ballistic projectile along its initial trajectory can be used to construct the air bag (25). However, the preferred embodiment of air bag (25) is constructed from SPECTRA®, due to its strength, ballistic protection properties, and the ease with which it can be used to fabricate the air bag (25). The thickness of the anti-ballistic fabric can be varied and should be chosen to match a particular threat.
The shape and dimensions of inflated air bag (25) can be modified to meet the required level of protection (e.g. projectile size and velocity), along with area coverage requirements. As shown, the inflated anti-ballistic air bag (25) has a pillow shape, and would be sized to cover a typical doorway if used as illustrated in FIG. 1B. That is, the dimensions would be roughly 4 ft. wide by 8 ft. high by 11/2 ft. thick at the widest portion. Air bag (25) is continuously attached to a base plate (250), located near the bottom of enclosure (20), and held in place with a pinching bar (not shown) around the periphery of base plate (250).
The seams of air bag (25) are sewn using SPECTRA® or other, similar fibers, and the structure of air bag (25) is reinforced using cross-ties (200), also of SPECTRA® or similar material so that the air bag (25) deploys vertically, rather than billowing horizontally. The size and position of cross-ties (200) are a function of the size of air bag (25), the required inflation time, and the size of the gas generator (210). Air bag (25) also contains reinforced vents (240) that are sized to control the peak pressure experienced during inflation of air bag (25) and therefore, the peak stress applied to the material used to fabricate air bag (25). Vents (240) located in top surface (245) of air bag (25) also act to provide a downward force which acts against base plate (250) due to vertical jetting of gas expelled through vents (240).
While the system is described as being implemented with SPECTRA® fabric, which is a trademark of the Allied Fibers Division of Allied Signal, Inc., other materials may be used. SPECTRA® fiber is an ultra-high molecular weight polyethylene fiber with high strength and low specific gravity. KEVLAR®, which is a trademark for aramid fiber sold by DuPont, or Dyneema™ can also be used. Also, such materials can be used in combination, such as combining woven ballistic fabric and a non-woven SPECTRA® fiber shield. This method is disclosed in U.S. Pat. No. 5,237,811 issued to Price, et al. Any material which is described as an ultra-high molecular weight polyethylene fiber, or fabric, or any other flexible material of sufficient strength to resist puncture by typical bullet-like projectiles and concussive explosion blasts can be used to implement the air bag of the instant invention.
Gas generator (210) is similar to that found in conventional automobiles, but larger in size and utilizing a faster burning oxidizer component. As illustrated in FIG. 3, a single gas generator (210) is used. However, multiple generators (210) can be used to reduce inflation time and prolong the duration of time during which air bag (25) remains effectively deployed. Gas generator (210) is affixed to base plate (250) and is surrounded by insulation (215) which provides a thermal barrier between gas generator (210), and the nearby base plate (250) and air bag (25).
Turning now to FIG. 4, a schematic block diagram of the present invention, using a bi-static radar detection system for ballistic projectiles, can be seen. In this embodiment of the invention, an analog signal processing system is illustrated, however, a RISC processor or other relatively fast digital computer can also be used to process signals from sensory components in the system to reliably detect the presence of a ballistic projectile or concussive wave front.
Power supply (305) is used to supply power to all components employed in the detection, discrimination, and gas generator activation circuits. In this particular embodiment, signal generator (310) supplies a 10.5 GHz signal (normally continuous wave, but modulation for anti-jamming and noise rejection may be added) to directional coupler (320). The generator signal is then amplified by amplifier (330) and passed to transmitting antenna (340) for illumination of incoming objects. The transmitted signal is applied to the general area surrounding personnel to be protected. Transmitting antennae (340) are operated with approximately 100 milliwatts of power at a frequency of 10.5 GHz. Dedicated receiving antenna (350) is passive. The bi-static system, using a separate transmitting antenna (340) and receiving antenna (350), provides greater received signal isolation and greater detection range by reducing receiver signal overload (due to spatial isolation between the respective antennae). Such a system also provides greater flexibility in shaping detection elevation and azimuth coverage. Receiving antenna (350) output is amplified by low noise amplifier (360) and mixed with a sample of the signal provided by signal generator (310) via directional coupler (320) and mixer (370). The resulting signal, introduced into broadband transformer (380) (North Hill Electronics, Inc. model 0016PA, or equivalent), is a Doppler-shifted beat signal. After passing the beat signal through high pass filter (390) (optimally operating at a 3 dB point of 6 kHz, with maximum rejection of 100 dB at 2 kHz), the signal is then amplified via received signal amplifier (400), further filtered by way of low pass filter (410) (optimally acting at a 3 dB point of 200 kHz, maximum rejection of 100 dB at 600 kHz), further amplified using signal amplifier (420), and passed on to tone decoder (430). The low noise amplifier (360) should have as low a noise figure as practical without being overly sensitive to in-band intermodulation. products. The broadband transformer (380) is not essential to system functionality, but is useful for isolating ground-induced noise and further limiting the received signal bandwidth to the bands of interest. The signal amplifier (400) is a low noise (S/N<4 dB) amplifier operating at the doppler frequencies (20 to 70 kHz). Performance is not critical to the operation of the circuit as long as it provides enough gain with the received signal amplifier (420) to trigger the tone decoder.
Tone decoder (430) responds to a Doppler shift produced by predetermined bullet velocities. The shift is determined by the well known equation Δf=2 Vf c /C, where Δf is the doppler shift, V is the velocity, f c is the CW frequency, and C is the speed of light. The tone decoders can be set for a nominal center frequency and bandwidth (bandwith should be limited to 14% of f c ). The circuit values illustrated in FIG. 5 produce a response frequency which corresponds to the velocity of a 9 mm bullet. Tone decoder response time varies with the velocity of the bullet plus many other factors. Another detection method requires designing of a recognition algorithm combined with digital signal processing of the sampled doppler waveform. Much better sensitivity and lower false alarms should be possible than those methods using simple tone decoders, which function adequately and provide a lower cost approach. Multiple tone decoders (430) (not shown) with overlapping frequency bands can also be used to detect a range of Doppler shift frequencies so that a corresponding range of ballistic projectile velocities can also be detected.
The ballistic protection embodiment of the present invention may be refined by using one or more transmit and receive antennas to produce a Doppler shift from ballistic projectiles entering a well-defined volume of space. Such antennae combinations would be placed in a specific series of locations optimized for ranging and simultaneously reducing the chance of false alarms by signal sources outside the radar field of view.
To overcome jamming which disables destructive force detection, or deliberate activation of the system through use of electromagnetic signals (either spurious or intended), anti-jamming circuitry is also included in the present invention. Various approaches are available, including signal amplitude and frequency coding, as is well known to those skilled in the art. Such coding may include simple sinusoidal amplitude or frequency modulation, which in turn would produce recognizable side bands on a true Doppler-shifted signal; such side bands would not appear as the result of a jamming signal. More sophisticated coding techniques, including signal doping, can also be used, but should be evaluated in light of possible additional inflation signal output delays, as derived from the resulting decoding constraints.
In other embodiments of the system, a RISC-type control processor, or other fast signal processors as are known in the art, may be used to conduct analysis of signals from receiving antenna (350) after such signals have been suitably filtered and digitized. Software may be used to do simple frequency detection. In addition, algorithms may be used to recognize specific signals for verification of frequency, amplitude, modulation, and/or spectral content of the acquired signal. Redundant hardware and/or processing algorithms can also be used to confirm the presence of a ballistic projectile or concussive wave front, to minimize the likelihood of accidental deployment.
Once the presence of a ballistic projectile has been reliably detected, then the firing circuit (440) is activated. The squib (450) (not shown) is located inside gas generator (210) and is used to ignite the oxidizer therein. The gas generator (or gas generators, since multiple units may be used, depending upon the application) is a Primex 28534-301 (or equivalent) with 68 ft 3 free volume and approximately 1 lb of propellant. The generator is initiated with a squib, such as an M-102 Atlas Match squib (or equivalent) typically using a firing signal of 3 amps or more at 12 volts for a duration of 2 ms or longer.
Tone decoder (430) can be constructed from a conventional LM567C tone decoder integrated circuit, or similar device, and is used to detect the presence of certain frequencies to determine the presence of a Doppler-shifted ballistic projectile signal.
Turning now to FIG. 5, the circuit diagram for tone decoder (430) is illustrated. As can be seen, tone decoder integrated circuit (460) of type LM567C, or similar, is surrounded by conventional components, the particular values of which are illustrated on the diagram. Individual component values are determined by formulas well-known in the art, and the values shown in the figure are typical for detection of a Doppler-shifted frequency generated by a 9 mm bullet. For example, it has been experimentally determined that the range of doppler shift varies from approximately 19 Khz to 26 kHz for a 9 mm bullet travelling at speeds of 900 fps to 1200 fps, respectively. For a 5.56 mm bullet, the shift goes from 64 kHz to 73 kHz for velocities ranging from 3,000 fps to 3,400 fps, respectively. Of course, multiple tone decoders, operating simultaneously, can be used in this particular embodiment of the present invention, any one of which is capable of activating firing circuit (440).
Turning now to FIG. 6, a schematic diagram of the gas generator squib ignition circuitry is illustrated, using typical component values well known in the art. Generally, a signal of at least 3 amps at 12 volts must be present for a duration of 2 ms or longer. The propagation delay involved in firing the squib after receiving the validated concussive shock wave or ballistic projectile detection signal is approximately one msec, depending on tone decoder detection time.
Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limited sense. Various modifications of the disclosed embodiments, as well as alternative embodiments of the inventions will become apparent to persons skilled in the art upon the reference to the description of the invention. It is, therefore, contemplated that the appended claims will cover such modifications that fall within the scope of the invention.
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A counter-terrorism, reactive personnel protection system which detects the presence of a concussive shock wave or ballistic projectile as it approaches a designated personnel target. Before impact, an air bag is rapidly inflated and interposed between the destructive force and the target so as to provide a protective barrier. The air bag is constructed from ultra-high molecular weight polyethylene material, and serves to halt or redirect the detected destructive force and thereby protect the designated target from attack.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of priority under 35 U.S.C. §119(a) to German Patent Application DE 10 2015 206 578.2, filed Apr. 13, 2015 (pending), the disclosure of which is hereby incorporated by reference in its entirety.
TECHNICAL FIELD
[0002] The invention relates to a handheld robot operation unit, comprising a housing that has a handle-like grip section, a basic safety control device arranged in the housing, and at least a holder connected to the housing, which is designed for the manually detachable, mechanic coupling of the housing to a device, different from the handheld robot operation unit and electronically communicating with the basic safety control device, and a corresponding method.
BACKGROUND
[0003] DE 10 2010 025 781 A1 describes a mobile safety input device with at least one input means for entering a safety signal to a robot control, which comprises an interface for communicating with a mobile device, connected particularly in a detachable fashion to the safety input device, for controlling a robot via communication with said robot control.
[0004] The objective of the invention is to provide a handheld robot operation unit and a corresponding method by which a particularly flexible and/or intuitive control, particularly programming of robots is possible.
SUMMARY
[0005] The objective of the invention is attained in a handheld robot operation unit, comprising a housing that has a handle-like grip section, a basic safety control device arranged in the housing, and at least one holder connected to the housing, which is designed for the manual, detachable and mechanical coupling of the housing to a device, different from the handheld robot operation unit and electronically communicating with the basic safety control device, with the fastener having a first holding arm, which is designed for a mechanic connection of the handheld robot operation unit to a first edge section of the device, leaving clear the opposite edge sections of the device, and a second holding arm, which is designed for a mechanic connection of the handheld robot operation unit with a second edge section of the device, which abuts the first edge section and this way forms a corner section of the device, leaving clear an edge section of the device opposite the second edge section.
[0006] The handheld robot operation unit may particularly be a mobile robot programming device. The handheld robot operation unit may also be a mobile manipulator control device and/or called such a device. The handheld robot operation unit may comprise at least one emergency stop trigger, at least one enabling device, at least one operating type selector, a 3D/6D-mouse, a joystick, and/or a display, particularly an illuminated and/or electronic display.
[0007] At least one emergency stop trigger, at least one approval device, and/or at least one operating type selector may be connected with secure technology to a robot control by way of a control system, particularly communicate with it.
[0008] The basic safety control device of the handheld robot operation unit is also designed and/or equipped to not only control a robot when the handheld robot operation unit is mechanically connected via the holder to the respective device, but can also be designed and/or equipped for controlling the robot when the handheld robot operation unit is mechanically distanced from the device. Additionally, basic control functions of the robot can also be controlled, mechanically separated from each other, via input means of the handheld robot operation unit. This may represent particularly the already mentioned emergency trigger, the approval device, and/or the operating type selector. Furthermore, other, perhaps not secured input means and/or display means may be provided at the handheld robot operation unit. This may include one or more displays, lighting means, switches, sensors, particularly for the menu control and for triggering touch-ups and/or start/stop keys, for example.
[0009] The device, electronically communicating with the basic safety device, may also represent a robot control, the robot arm itself, and/or a robot frame, a mobile robot platform, and/or particularly a mobile terminal.
[0010] In case of a mobile terminal, particularly a computer tablet as the device electronically communicating with a handheld robot operation unit, the mobile terminal and/or the tablet may have a program-controlled electronic computer, a touch display, and a program saved in the electronic computer, which is designed to generate robot programs and/or to control a robot, particularly for moving a robot arm and the touch display, and can be operated via the touch display.
[0011] The holder according to the invention is designed for the manual connection of the handheld robot operation unit to the respective device electronically communicating. A user, for example a robot programmer, can manually detach the handheld robot operation unit from the device electronically communicating and/or connect it thereto without requiring any tools. The holder is designed here for the manually detachable mechanic coupling of the housing, without requiring any tools, to a device, different from the handheld robot operation unit, and electronically communicating with the basic safety control device.
[0012] By the holder comprising a first holding arm, which is designed for the mechanic connection of the handheld robot operation unit to a first edge section of the device, leaving clear the opposite edge section of the device, and a second holding arm, which is designed for the mechanic connection of the handheld robot operation unit to a second edge section of the device, which is adjacent to the first edge section and here forms a corner section of the device, leaving clear an edge section of the device opposite the second edge section, optionally different devices with various sizes can be mechanically connected to the same handheld robot operation unit without any structural changes being required in the device and/or in the handheld robot operation unit. Respective adjustments can be waived, because a mechanic coupling of the handheld robot operation unit to the device always occurs only at a corner section, particularly a right-angle corner section of the device. This way, independent from the respective size of the device, the handheld robot operation unit can be mechanically fastened via the same holder at a corner of the device. Such a mechanic fastening occurs here such that no additional adapters are required and no changes must be made to the device. With the holder according to the invention, devices with right angles, particularly devices that are not square, can also be optionally coupled horizontally or laterally to the handheld robot operation unit in a mechanic fashion. This applies particularly for tablet-like devices, such as mobile terminals and computer tablets. The handheld robot operation unit can also be mechanically coupled to other devices, such as robot arms, mobile robot platforms, or other bases, for example at edges of a table-like coupling site of the respective device abutting in a corner section, i.e. of a robot arm, the mobile robot platforms, or other bases.
[0013] Each holding arm can encompass a corresponding edge section of the device in a form-fitting and/or force-fitting fashion. The two holding arms are always designed and/or arranged such that only a single corner of the device is engaged, with the other corners of the device remaining clear and not engaged by a holder, particularly the remaining three corners in case of a rectangular device. In case of rectangular or square devices, the holding arms are designed and/or arranged to mechanically encompass a rectangular corner of the device.
[0014] The first holding arm may have a first groove-like seat, which is designed to encompass the first edge section of the device, and the second holding arm may here have a second groove-like seat, designed to encompass the second edge section of the device, with the two groove-like seats being arranged with their longitudinal extension at an angle, particularly a right angle in reference to the first groove-like seat.
[0015] Each groove-like seat comprises here a groove bottom, which connects two groove walls, particularly aligned parallel in reference to each other. An upper groove wall of the two groove walls rests on an upper side of the device, when the device is plugged to the handheld robot operation unit. The lower groove wall of the two groove walls contacts the bottom of the device when the device is plugged to the handheld robot operation unit. The two groove walls and perhaps also the groove bottom may have profiled inserts. The profiled inserts may be designed elastically in order to allow independent adjusting to the contour of the device. Alternatively or additionally the profiled inserts may have a profiled design in their cross-section, which is at least approximately or precisely adjusted to the shape of the device. The profiled inserts may be installed fixed to the groove-like seats. Alternatively, the profiled inserts may also be inserted in a fashion detachable from the groove-like seats. By the profiled inserts being deformable or interchangeable, devices of different thickness can optionally be mechanically coupled to the very same handheld robot operation unit.
[0016] The housing may have a first housing leg, in which the first holding arm is arranged, and a second housing leg, with the second holding arm arranged thereat, with the first housing leg and the second housing leg stretching a level of the housing which extends parallel to a main level of the device held and extends from the handle-like grip section of the handheld robot operation unit downwards, particularly perpendicular away from said level. However, the handle-like grip section can particularly also be arranged in a different orientation, here at an angle from approx. 20 to 25 degrees in reference to the vertical. This way, ergonomic edge conditions of the human physique can be better considered.
[0017] The first housing leg and/or the second housing leg may be designed in one piece with the housing. The first housing leg and the second housing leg may be arranged at a fixed angle, particularly at a fixed right angle in reference to each other. The two housing legs may stretch a level with their longitudinal extensions, aligned parallel to the one of the device, when it is mechanically coupled to the handheld robot operation unit.
[0018] The first holding arm and the second holding arm, particularly the first groove-shaped seat and the second groove-shaped seat, may be formed by a bracket, having an L-shaped or U-shaped cross-section, and a compression plate supported in a fashion adjustable in reference to the bracket.
[0019] In case of an L-shaped cross-section, one leg of the L-shaped holding arm and/or the L-shaped seat forms the groove bottom and the other leg forms one of the groove walls, either contacting the top or the bottom of the device. The adjustably supported compression plate forms here the other of the two groove walls, either contacting the top or the bottom of the device.
[0020] The compression plate may also be supported in an adjustable fashion, out of a default position into a seating position, subject to a spring-loaded return force, in which, when the device is attached to the handheld robot operation unit, the two edge sections of the device, abutting at an angle, are seated by the first holding arm and the second holding arm, particularly the first groove-shaped seat and the second groove-shaped seat, in a form-fitting and/or force-fitting fashion.
[0021] By the compression plate being supported in an adjustable fashion, out of a default position into an seat position with a returning spring force, here the width of the groove of the holding arm and/or the groove-like seat can be adjusted. In other words, this way the two opposite groove walls can be opened or expanded such that the respective edge section of the device can be easily inserted, i.e. with little manual force. The compression plate can be connected to a spring device, which automatically pushes the compression plate against the default position. When a device is inserted, here the spring device pushes the compression plate against the device, for example against the bottom of the device, and clamps the device at its edge section to the opposite groove wall, which comes to rest at the top of the device.
[0022] The first holding arm and the second holding arm, particularly the first groove-shaped seat and the second groove-shaped seat, may have a stop area, which is designed to contact a front of the device in an seat arrangement of the device at the handheld robot operation unit, and the compression plate is designed for contacting the rear of the device, with the compression plate being supported in an adjustable fashion in reference to the stop area in order to seat differently thick devices.
[0023] The compression plate and the stop area limit therefore the groove-like seat into which the device is inserted. By the compression plate being supported in an adjustable fashion in reference to the stop area, the size of the groove-like seat can be adjusted to the thickness of the device respectively to be inserted.
[0024] The compression plate may be supported in a linearly adjustable fashion in reference to the stop area. For this purpose, the handheld robot operation unit may have a linear guidance, which allows a linearly adjustable support of the compression plate in reference to the stop area. The linear guidance can here have a spring device, which automatically moves the compression plate into a default position or against the stop area. In the default position of the compression plate the compression plate can abut flush at the contact area, i.e. aligned in the same level.
[0025] The adjustable compression plate may be supported in a linearly adjustable fashion together with the handle-like grip section.
[0026] The adjustable compression plate may also be supported in a linearly adjustable fashion in reference to the stop area and the handle-like grip section, in particular the handle-like grip section may be fastened rigidly with regards to the stop area.
[0027] The compression plate may be supported pivotally in reference to the stop area.
[0028] The compression area may form a type of closing cap of a groove-like seat in such an embodiment. In a default position, in which the device is removed, the pivotally supported compression plate may cover and/or seal the groove-like seat. When the device approaches, a lateral edge of the device presses flatly against the compression plate, pivoting it inwardly into the cavity of the groove-like seat. The edge section of the device can then be seated in the groove-like seat. The pivotally supported compression plate may be supported in a pre-stressed fashion by a spring such that the compression plate in a position seated in a groove-like seat of the device presses against the top or optionally against the bottom of the device and this way the device is clamped fixed in the groove-like seat. When it is attempted to pull out the device, the pressure of the pivotally supported compression plate upon the device is additionally enhanced, resulting in a particularly reliable mechanic coupling of the device to the handheld robot operation unit.
[0029] The first holding arm and the second holding arm, particularly the first groove-like seat and the second groove-like seat, may have a clamping profile made from an elastic material, particularly a hollow chamber profile comprising an elastic material.
[0030] The clamping profile may have at least one, particularly two wedge-shaped inner walls. This way, the device can be inserted and the clamping profile presses against opposite sides, i.e. at the top and the bottom of the device against said device and this way clamps it tightly. The clamping profiles may be produced from an elastomer material.
[0031] The clamping profile, particularly the hollow chamber profile, may be expandable via a fluid, particularly compressed air, in order to generate a clamping force. Accordingly, the handheld robot operation unit may have a fluid reservoir and/or a fluid pump. Via the fluid pumps the fluid can be pumped into at least one hollow cavity of the hollow chamber profile so that the hollow chamber profile increases and this way the edge section of the device can be clamped inside the groove-like seat.
[0032] In all exemplary embodiments the basic safety control device may have at least one emergency stop trigger, at least one enabling device, at least one operating type selector, and/or at least one display means, particularly at least one electronic display.
[0033] In general, the handheld robot operation unit may have a holder, particularly a holder as described above, which is designed for fastening the handheld robot operation unit to a device, particularly a robot arm, a control base, a mobile robot platform, and/or a mobile terminal, particularly a computer tablet.
[0034] The described holder according to the invention may be designed, in addition to the option for coupling a mobile terminal, particularly a computer tablet, to allow mechanically coupling the handheld robot operation unit to a corresponding edge of a robot arm, a control base, and/or a mobile robot platform. For this purpose, the robot arm, the control base, and/or the mobile robot platform may have a brace, which comprises an edge section at which the holder, particularly the groove-shaped seat of the handheld robot operation unit, can be mechanically coupled.
[0035] However, the handheld robot operation unit may also have a holder separated from the one described according to the invention, i.e. an additional one, which is designed to allow mechanically connecting the handheld robot operation unit to the robot arm, the control base, and/or the mobile robot platform. Alternatively, the robot arm, the control base, and/or the mobile robot platform may have a seating niche, in which the handheld robot operation unit and/or its housing can be inserted at least partially or even totally.
[0036] In all embodiments the handheld robot operation unit may have a manual actuating means, particularly an actuating means arranged at the handle-like grip section, which is designed to keep the holder in a clamped position in the locked stage of the actuating means, and to release the holder from the clamped position in an unlocked stage of the actuating means.
[0037] The actuating means may be integrated in the handle-like grip section. For example, the actuating means may be designed to be operated only with one finger of one hand, when a user of the handheld robot operation unit holds the handle-like grip section in his/her hand. For example, the holder can be released with one hand and the device can be removed from the handheld robot operation unit with the other hand. When the device is mechanically coupled to the handheld robot operation unit the actuating means can lock automatically and fix the holder in the clamping position.
[0038] The handheld robot operation unit according to the invention may offer one or more of the following advantages, depending on the embodiment.
[0039] With the holder according to the invention a handheld robot operation unit can be provided, which allows universal coupling and fastening options with almost any computer tablet, i.e. independent from size and manufacturer. With the holder according to the invention the handheld robot operation unit can be used both by right-handed persons as well as left-handed ones. Additionally, the devices, particularly computer tablets, can optionally be used in a lateral alignment or a longitudinal alignment, without here requiring any changes or adjustments of elements at the computer tablet or the handheld robot operation unit.
[0040] The invention also allows the use of the handheld robot operation unit according to the invention in mobile robotics, so that here too always a secure state of the system is ensured.
[0041] The invention also allows the use of the handheld robot operation unit according to the invention in stationary robotics, so that here too always a secure state of the system is ensured.
[0042] Alternatively, for manually moving a robot, either in a mobile or a stationary fashion, for example via a 6D-mouse or the control keys at the mobile control device and/or via hardware or software keys, the robotic system can also be controlled by gestures, such as manual guiding. Here, the mobile control device may also be fastened via a standard adapter directly at the robot and/or the mobile platform. The user can guide the system via the 6D-mouse into the desired position, without requiring any force. Alternatively, the 6D-mouse may also be coupled via a mechanic adapter interface on the top directly to the system to be moved.
[0043] When the directions of motion are inverted automatically in the control, the user can very easily and intuitively guide any arbitrary robot system manually, by moving and/or rotating, particularly with one hand, the grip into the desired direction and here simultaneously activating the enabling key. By pressing the teach-keys the points are then saved in the program.
[0044] The operation of a redundant robot system can also occur intuitively and directly via hardware keys, such as 6D-mouse or individual keys, by the degrees of freedom being addressed in groups in a suitable fashion and zero-space motions being used efficiently.
[0045] The present invention shall realize a mechanic coupling concept. Here, focus is given to a simple, quick, and stable coupling and decoupling principle, which allows the integration of arbitrary devices, such as particularly computer tablets with different dimensions and key and/or connection arrangements. Here, intentionally special solutions are waived, which require adjustments, changes, or special features at the device.
[0046] It shall be possible to easily connect all models of different manufacturers, from small smart phones to large industrial computer tablets, mechanically to the handheld robot operation unit so that the user can hold and operate all safety switches, as well as robot-specific keys comfortably in one hand, together with the computer tablet. A quick exchange from the vertical format to the lateral one or vice versa is also possible by a simple device reorientation at the handheld robot operation unit, such as the change from the holding hand operated by a right-handed person to a left-handed person.
[0047] The effective areas of the clamping are limited to the corner section and the two corresponding legs of the device, particularly a tablet computer. This allows, on the one hand, a stable conduction of force and moment support on minimum structural space and on the other hand an only minimal covering of the top of the device and/or the display. The primary clamping sites at the device, particularly at the computer tablet, shall be limited at least largely to the bottom as well as the edge section next to the display.
[0048] The holder according to the invention provides optimal stability of the clamping connection with simultaneously the advantages described above. For example, a secure and simultaneously easily applied clamping function is given, which prevents any accidental release of the device even when shaken. Although in the following the invention is explained in greater detail based on a computer tablet, these aspects can generally also apply according to the invention to other types of devices.
[0049] For this purpose, in the position of the tablet in the lateral direction it may contact in a defined fashion at two lateral stops in a corner arrangement, while two L-shaped braces, articulate in reference to each other, clamp the tablet with friction elements at the edge of the top and bottom securely in the area of a corner. The normal force for friction is generated in an exemplary variant with a central plate via a helical spring with an inclined parameter, which ensures that small, flat tablets or smart phones can easily be clamped, and heavier, thick tablets are clamped with a stronger force. The braces or clamping braces may be designed at the holding arms and/or at the grooves of the holding arms and/or directly be formed thereby.
[0050] A relative motion of the two braces comprises here the spectrum at different tablet heights, which shall be clamped, which generally ranges from 0 mm to 20 mm. A parallel guidance of the braces may be realized via a simple rail-sled solution.
[0051] When the handle for holding the mobile control device incl. the tablet is connected fixed during use with the clamping braces located at the bottom, the actuating forces upon the tablet are usually directed straight to the handle. This releases the clamping connection and avoids that the tablet is accidentally pushed out of the fastening.
[0052] In order to insert and remove the tablet the spring-loaded clamping braces are pushed apart by a manual actuating force at an additional trigger key such that an easy tablet handling is possible. Here, the trigger key is designed in such a form that it simultaneously serves as a type of holding grip for the mobile control device. This may be necessary, because the user must hold the mobile control device with one hand, while he/she inserts and/or removes the tablet with the other one. Due to the fact that this process requires the actuation of the trigger key, it may be located in direct proximity of the holding grip or form a unit with said holding grip. After insertion, the user changes his/her grip from the holding grip to the handle of the mobile control device, which is provided to carry and control the device. The holding grip and the handle are generally two differently formed elements at the mobile control device, which may also be combined in special cases of the embodiment.
[0053] Optional top and bottom friction areas of the L-shaped braces may be arranged such that they contact oppositely, i.e. at a zero distance, or that they pass each other slightly offset from one another. Here, the tablet is clamped either by compression or by shearing. When the two friction areas, as in the first case in the zero position when no tablet is inserted, are pressed against each other, they are only open briefly during the coupling process. This way, a loss of friction, caused by soiling or contamination of the contact areas, can be considerably reduced.
[0054] The bottom L-shaped brace, connected to the handle, can be expanded in the central part in a planar fashion such that here structural space develops for a flat simple display, which is covered by an inserted tablet and thus is functionally replaced. This central plate is advantageous, in combination with the above-explained clamping principle, in that visual gaps are avoided and a uniformly closed appearance develops, both with as well as without any tablet inserted. Simply stated and in other words, the clamping gap is always just as wide as absolutely necessary. Without any tablet, the gap is therefore completely closed and the central plate with the display and the bottom clamping braces visually transfers evenly or at best with a minimum step into the upper clamping braces, on which the control and safety keys shall rest. This underscores the valuable character of the mobile control device, representing a complete and independent compact unit.
[0055] The handheld robot operation unit may form a portable and/or compact unit which can easily be coupled, disconnected, and transported, particularly carried by hand. By the handheld robot operation unit the capacity, display quality, and/or the user friendliness of newest devices, such as mobile terminals, as for example computer tablets for controlling a robot can be used.
[0056] Integration and coupling options for several tablet models and series of different manufacturers can be provided here. Even newly obtained models can easily be integrated and used without little expense. User requirements and user demands regarding hardware and software can be considered by an individual selection of the mobile terminal. The user of the robot profits from the constant further development of mobile terminals, particularly computer tablet and their capacities. A new device can easily be integrated, which is possible with little expense and low costs. Different users can easily connect their various mobile terminals, particularly computer tablets, optionally to the same robot using mechanic and control engineering. A user may select from the wide spectrum of mobile terminals, such as computer tablets, depending on performance and price category most appropriate for him/her. Here, a mixture may also be possible. For example, simple mobile terminals and/or computer tablets for maintenance and service technicians may be provided and very powerful mobile terminals and/or computer tablets may be provided, for example for developers or testers of applications.
[0057] The handheld robot operation unit may therefore form a basic control device for the robot. It may offer a basic functionality at the robot, primarily with regards to a safety functionality. The handheld robot operation unit alone can be designed cost-effectively and in a standardized fashion. It may remain at the robot and/or in the proximity of said robot or distanced therefrom. One handheld robot operation unit may be provided per robot. It may be implemented to provide only simple mechanic and electric coupling options, with the basic safety control device not necessarily requiring any changes or upgrades, but it may be sufficient to exchange or replace for example the mobile terminal when progressive retrofitting shall be provided. The handheld robot operation unit may be designed in an appealing fashion and like a complete unit, even without any device and/or mobile terminal at least operational in its basic functions.
[0058] By the holder according to the invention the handheld robot operation unit can optionally be used autonomously, i.e. separated from other devices electronically communicating with the mobile robot control, or it may be connected to the respective device in a particularly temporary mechanic connection. For example, the handheld robot operation unit may be mechanically coupled, particularly in a temporary fashion, to most different devices. Additionally, by the holder according to the invention the handheld robot operation unit can be mechanically coupled at various points of the same device and/or in most different alignments of the handheld robot operation unit at the same device. For example, different ergonomic embodiments of the handheld robot operation unit and the device may be created. For example, the same device, such as a mobile terminal like a computer tablet, can be altered by different plug-in sites of the handheld robot operation unit from a right-handed operation into a left-handed operation and/or into a longitudinal format or a lateral format.
[0059] In general, by the holder according to the invention at least one mechanic connection is provided between the handheld robot operation unit and the electronically communicating device. The mobile robot control unit itself is connected by control technology in general to a robot control such that by operating the basic safety control device of the handheld robot operation unit the robot control is addressed in order to move for example the robot arm or control the mobile robot platform. A connection between the robot control, the handheld robot operation unit, and the electronically communicating device, particularly a mobile terminal, such as a computer tablet using control engineering, may be an electric connection. Here, the handheld robot operation unit may communicate securely either wirelessly or wired to the robot control. Additionally, the electronically communicating device, particularly the mobile terminal such as a computer tablet, can be directly connected to the robot control or electrically coupled to the handheld robot operation unit and this way use the already existing communication of the handheld robot operation unit to the robot control. The commands or signals transmitted via the electronically communicating device, particularly via the mobile terminal such as the computer tablet, to the computer control, can be transmitted using safe technology or non-secured technology. The handheld robot operation unit with its safety-relevant operator functionality, such as emergency shut-off or enabling key, must however be connected securely to the robot control. A wireless interface of the electronically communicating device, particularly the mobile terminal, such as the computer tablet, can also be used at a work site distanced from the robot for a wireless communication, for example using an external keyboard, mouse, and/or an external monitor.
[0060] The invention can therefore connect, depending on the embodiment of the two worlds, a secure and reliable industrial control and progressive, user-friendly and powerful consumer electronics to each other and this way open new paths in an efficient and simple robot operation and robot control.
[0061] This invention describes the basic concept as well as exemplary embodiments of a temporary, mechanic coupling of a device, separate from the handheld robot operation unit communicating electronically, particularly a mobile terminal with safety-relevant robot and/or equipment-specific basic operating elements, which are provided on the handheld robot operation unit, i.e. the basic safety control device of the handheld robot operation unit.
[0062] By the technical solution of a mechanical and technical coupling of controls, by connecting the handheld robot operation unit to a separate electronically communicating device, such as for example a mobile terminal, like a computer tablet, to a robot control in order to control said robot, accordingly different device systems can be generated, which can be combined for many operating scenarios, such as shown among other things in exemplary embodiments of the figures.
[0063] The basic safety control device may have in all variants of the embodiment at least one emergency stop trigger, at least one enabling device, at least one operating type selector, and/or at least one display, particularly at least one electronic display.
[0064] The handle-like grip section of the handheld robot operation unit may be designed like a handle of a ski pole or a pistol grip, for example. The handle-like grip section of the handheld robot operation unit may therefore have a circumference, which is maximally so large that its housing section may be encompassed at its jacket wall at least approximately completely by the hand of the user. Additionally, recess-like indentations may be provided at the jacket wall, which are designed for inserting one finger each of the hand of the user at respectively one recess-like indentation at the jacket wall. The recess-like indentation may therefore be adjusted in size, shape, and alignment with regards to ergonomic aspects to a hand of a human being. An upper section of the jacket wall may project, in a manually grasped condition of the handheld robot operation unit, beyond the first of the holding user towards the top and comprise the holder according to the invention. A sub-section of the jacket wall may project in a manually grasped condition of the handheld robot operation unit beyond the first of the holding user towards the bottom.
[0065] The total period in which the user operates the active robot, programs it, manually displaces it, analyzes or changes settings or parameters, is usually very short compared to the overall operating period. In this short period of time, a user device is desired as high-quality, capable, and user-friendly as possible, in order to allow an efficient, quick, and flawless operation with minimal downtime of the robot. In the remaining time, i.e. during the normal operation of the robot in automatic operation, only a few basic functions are required for operation, primarily safety functions and status displays; thus high functionality of the control device is not required permanently or only in a very targeted fashion and only briefly.
[0066] An approach to temporarily increase the functionality to a considerable degree is the separation of high-quality operating functions and simple basic functions in two spatially separated units. The two units may meet, in addition to different operating functionality, also different safety requirements.
[0067] A temporary coupling of these units allows avoiding a dual assignment of functions, such as for example safety hardware keys, and thus reduces costs and structural space.
[0068] The goal is to provide an operating concept, both with respect to technical operation as well as economic feasibility, in which a cost-effective basic operating device is used with basic functionality and a powerful computer tablet from the consumer field.
[0069] The invention presented here relates to such a basic control device, i.e. a handheld robot operation unit, designed as a multi-functional control grip that has various coupling options to stationary or mobile machines, as well as robots or different control devices. It serves as a universal base device and has, depending on its coupling partner, i.e. an electronically communicating device, different functionalities and differential scopes of functions. The invention offers essential advantages over the known concepts and control and input devices presently available in the market, for example that a single universal basic device can be used for most different fields of application in robotics, which can be coupled to different partners allowing the functionality to be adjustable depending on the coupling partner. Used as coupling partners may be, for example, active systems, such as robots and mobile platforms, and/or passive systems such as the environment and cell frames, as well as additional input devices, such as computer tablets, smart phones, and/or measuring and analysis systems, such as camera/tracking systems or force measuring sensors. The particular embodiment of the basic device with a handle-like grip section offers an ergonomic and intuitive operation with simultaneously compact and user-friendly dimensions. The ergonomic form of the handle as well as the hardware keys for safety functionality and basic operation are also required in the coupled state in order to hold the coupled partner, for example a computer tablet, or for example to guide a robot and here always allowing to access functions, such as enabling and emergency-off. The most important status reports and system conditions can also be displayed without any computer tablet coupled, directly at the control handle.
[0070] The coupling concept allows a free expansion and adjustment of coupling partners and potential coupling sites, which are essentially separate from the geometric embodiment of the coupled partners. Accordingly, arbitrary models of computer tablets of different sizes, key positions, and connections can be connected in a simple fashion, using the handheld robot operation unit according to the invention.
[0071] In order to allow fulfilling different requirements set for a robot control device over its life cycle, either a very high-quality operation device can be used for each robot unit or, in the sense of the invention, a minimalistic basic operating handle can provide the required basic safety functions.
[0072] This simple and cost-effective basic operating handle, i.e. a handheld robot operation unit according to the invention, can temporarily be coupled to another, this time very high-quality separate device, such as a standard computer tablet, in order to allow briefly a powerful operation. Here, any robotic unit, such as a robot or mobile platform, may have perhaps at least one such basic operating handle for every cell. The high-quality separate devices are here not allocated to fixed units of handheld robot operation units, and can therefore always be used as necessary at the location they are needed. The number of these computer tablets, for example, depends on the type and size of the overall arrangement and can be easily increased by the user independently and on short notice.
[0073] The invention therefore provides a control concept, which uses resources efficiently at the location required, and in spite thereof allows at all times secure control of the basic functions on site of the unit. This allows to offer to the user a very powerful robot control, which always meets the standards of present state of the art, offers the user very economic robot control, which always optimally utilizes the resources available, and among other things creates standard input units, offers to the user a very secure robot operation fulfilling all necessary guidelines and standards, and offers to the user a very intuitive, efficient, and individual robot operation, which can be configured via the graphic user surface of the tablet completely freely and specific for the application and the user.
[0074] The handheld robot operation units can therefore be designed such that optionally one of several possible, different mobile terminals, particularly mobile terminals of different model types and/or sizes can be connected to the same basic safety control device, and the selected mobile terminal can be mechanically connected in an inserted or attached condition to the basic safety control device.
[0075] The goal of the invention can therefore be to provide an industrial handheld robot operation unit, which with regards to control standards and safety regulations as well as environmental influences and/or ergonomic features can be held at an advanced level of quality during operation. With the holder according to the invention it is possible to connect for example present commercially available mobile terminals to an existing basic safety control device, and this way very powerful mobile terminals presently available in the market can be used for controlling industrial handheld robot operation units.
[0076] Using the holder according to the invention, differently designed mobile terminals can be connected mechanically to the particularly uniform basic safety control device in a particularly simple and flexible fashion. Using the holder according to the invention, for example the mobile terminal can even be optionally separated or connected manually by a user from the basic safety control device. For example, here two or more devices, i.e. the uniform basic safety control device and the selected mobile terminal can be combined to each other, or each individual device may be used separately. The handheld robot operation unit, particularly the basic safety control device is here operational in an autonomous fashion in a safe operation to such an extent and for example the removed device is also independently operational, although not with secured technology. Consequently, here several adequate operating devices can be generated for different scenarios.
[0077] Deviating from solutions of prior art, the user is additionally provided with the option by the handheld robot operation unit according to the invention to manually control or stop a robot at any time using a handheld robot operation unit connected to the robot, particularly directly or in a mechanic fashion, with regards to common or minimum basic functions. This simple handheld robot operation unit can be expanded by mechanical and technology engineering coupling to a robot, a mobile robot platform, and/or a mobile terminal, such as a computer tablet or a smart phone to form a high-quality and multifunctional mobile control device, which is suitable even for very complex and complicated programming, analysis, and service tasks. In the separate operation of a mobile terminal, such as a computer tablet, also detached from the handheld robot operation unit, this mobile terminal is portable and can be used locally independent, e.g., at the work site, in the office, or in a conference room individually or for example in combination with external monitors or external input devices in order to prepare offline certain processing steps or programs for the robot, evaluate data gathered, and/or inquire about status reports and/or conditions of one or more robots via distant monitoring. Furthermore, in this case the mobile terminal can be used as a user-based, personal input device of the handheld robot operation unit. This is advantageous in that for example several persons may work in different functions for the same robot, with perhaps optimal configurations, e.g. regarding software equipment, user data, such as cookies, accounts, and/or access rights, being individually generated on the mobile terminal and/or can be recalled at a later day.
[0078] The objective according to the invention is additionally attained in a method for operating a handheld robot operation unit, particularly according to one or more embodiments as described, having a basic safety control device comprising a holder, designed for the manual connection of a device communicating electronically with the basic safety control device to the basic safety control device, comprising the step:
[0079] clamping the device to the holder of the handheld robot operation unit only at a single corner section of the device.
[0080] A further development of the method according to the invention comprises the step:
[0081] automatically and/or manually releasing the clamped device such that a robot arm or a mobile robot platform can be addressed by operating input means of the device when the basic safety control device is connected to the device and/or an electronic communication is established between the basic safety control device and the device, and the device is clamped fixed in an orderly fashion, particularly securely, to the handheld robot operation unit.
[0082] Another further development of the method according to the invention includes the step:
[0083] manually operating the basic safety control device for controlling a robot arm or a mobile robot platform when the basic safety control device is separated from the device and/or an electronic communication between the basic safety control device and the device is interrupted, particularly no sufficient clamping is given between the handheld robot operation unit and the device.
[0084] Several exemplary embodiments of the invention are explained in greater detail in the following description with reference to the figures. Specific features of these exemplary embodiments may include general features of the invention, regardless of context in which they are mentioned, that may be comprised individually or in other combinations.
BRIEF DESCRIPTION OF THE DRAWINGS
[0085] FIG. 1 a schematic illustration of a robot, comprising a robot arm and a robot control, as well as a handheld robot operation unit according to the invention,
[0086] FIG. 2 a perspective illustration of a special embodiment of the handheld robot operation unit standing alone,
[0087] FIG. 3 a perspective illustration of the handheld robot operation unit according to FIG. 2 from the rear,
[0088] FIG. 4 a side view of a handheld robot operation unit according to FIG. 2 ,
[0089] FIG. 5 a perspective illustration of a handheld robot operation unit according to FIG. 2 from the bottom,
[0090] FIG. 6 an illustration of a system of a manual robot control device and a device attached to the manual robot control device in the form of a mobile terminal like a computer tablet,
[0091] FIGS. 7-10 various schematic perspective illustrations of compression plates and their potential adjustments to the handheld robot operation unit,
[0092] FIGS. 11-12 various schematic perspective illustrations of clamping profiles of the manual robot control device,
[0093] FIG. 13 a schematic perspective illustration of a combination of clamping profiles with an adjustably supported compression plate,
[0094] FIG. 14 a schematic perspective illustration with pivotally supported compression plates,
[0095] FIG. 15 a schematic perspective illustration with a hollow chamber-clamping profile, which can be expanded via a fluid,
[0096] FIGS. 16-18 various schematic, exemplary variants of holding arrangements between the handheld robot operation unit and different devices, and
[0097] FIGS. 19-20 two exemplary variants of manual actuating means, which are arranged in the handle-like grip section of the manual robot control device.
DETAILED DESCRIPTION
[0098] FIG. 1 illustrates a robot 1 , comprising a robot arm 2 and a robot control 12 . The robot arm 2 comprises, in case of the present exemplary embodiment, several links 14 arranged behind one another and connected via joints 13 . The links 14 particularly represent a frame 3 and a carousel 4 , supported rotational in reference to the frame 3 about an axis A 1 which extends vertically. In case of the present exemplary embodiment, further links of the robot arm 2 are a link arm 5 , a cantilever 6 , and a robot hand 7 comprising preferably several axes with a fastening device, designed as a flange 8 , for fastening an end effector not shown in greater detail. The link arm 5 is supported in a pivotal fashion at the bottom end, e.g., at a link bearing head not shown in greater detail on the rotating carousel 4 about a preferably horizontal axis of rotation A 2 . At the upper end of the link arm 5 in turn the cantilever 6 is supported in a pivotal fashion about an also preferably horizontal axis A 3 . It carries at the end the robot arm 7 with its preferably three axes of rotation A 4 , A 5 , A 6 .
[0099] The cantilever 6 shows, in case of the present exemplary embodiment, an arm housing 9 supported pivotally at the arm link 5 . A basic hand housing 10 of the cantilever 6 is supported at the arm housing 9 , pivotal about the axis of rotation A 4 .
[0100] The robot arm 2 is mobile via three electric drive motors 11 in its three basic axes and via three additional electric drive motors 11 in its three axes of the hand.
[0101] The robot control 12 of the robot 1 is designed and/or implemented to execute a robot program, by which the joints 14 of the robot arm 2 can automatically be adjusted and/or rotationally moved automatically according to the robot program or in a manual drive operation. For this purpose, the robot control 12 is connected to the electric drive motors 11 that can be addressed, which are designed to adjust the joints 14 of the robot arm 2 . With the robot control 12 , a handheld robot operation unit 15 is connected by control engineering.
[0102] FIG. 2 shows the handheld robot operation unit 15 . The handheld robot operation unit 15 has a housing 16 and a basic safety control device 17 arranged inside the housing 16 . The housing 16 comprises a handle-like grip section 16 a . The basic safety control device 17 may comprise an electronic circuit board, which is electrically connected to input and/or output means.
[0103] The basic safety control device 17 may have as an input and/or output means at least one emergency stop-trigger 18 , at least one enabling device 19 ( FIG. 3 ), at least one operating type selector 20 , at least one 3D/6D-mouse 21 , and/or a joystick and/or at least one display, particularly an electronic display.
[0104] The handheld robot operation unit 15 has a holder 22 , which is designed for the manual and detachable mechanic coupling of the housing 16 to a device 23 , which is different from the handheld robot operation unit 15 and electronically communicates with the basic safety control device 17 . The holder 22 comprises a first holding arm 22 . 1 , which is designed for the mechanic connection of the handheld robot operation unit 15 to a first edge section 23 . 1 of the device, keeping clear an opposite edge section 23 . 3 of the device 23 . The holder 22 additionally comprises a second holding arm 22 . 2 , which is designed for the mechanic connection of the handheld robot operation unit 15 to a second edge section 23 . 2 of the device 23 , which is adjacent to the first edge section 23 . 1 and here forms a corner section 24 of the device 23 , keeping clear an edge section 23 . 4 of the device 23 opposite the second edge section 23 . 2 .
[0105] As shown particularly in FIG. 2 , the first holding arm 22 . 1 has a first groove-like seat 24 . 1 , which is designed to encompass the first edge section 23 . 1 of the device 23 . The second holding arm 22 . 2 also has a second groove-like seat 24 . 2 , which is designed for encompassing the second edge section 23 . 2 of the device 23 . The second groove-like seat 24 . 2 is here arranged with its longitudinal extension at a right angle in reference to the first groove-like seat 24 . 1 .
[0106] The embodiment shown in FIGS. 2 to 6 has the housing 16 of the handheld robot operation unit 15 of a first housing leg 16 . 1 , which is arranged at the first holding arm 22 . 1 . In this embodiment the housing 16 of the manual robot control device 15 additionally comprises a second housing leg 16 . 2 , at which the second holding arm 22 . 2 is arranged. The first housing leg 16 . 1 and the second housing leg 16 . 2 here stretch a level of the housing 16 , which extends parallel to a main level of the device 23 held ( FIG. 1 and FIG. 6 ) and from which the handle-like grip section 16 a of the handheld robot operation unit 15 extends away towards the bottom, particularly perpendicular to the level. As shown in FIG. 5 , at a bottom of the handle-like grip section 16 a , the handheld robot operation unit 15 may have electric connections 25 . The electric connections 25 may for example be charging contacts, by which an internal battery and/or an internal accumulator of the handheld robot operation unit 15 can be charged by an external electric energy source. The electric connections 25 may however also represent contacts of a signal line, which allows a wired electronic communication of the handheld robot operation unit 15 to an external device.
[0107] In the embodiment shown in FIGS. 2 to 6 the first holding arm 22 . 1 and the second holding arm 22 . 2 , particularly the first groove-like seat 24 . 1 and the second groove-like seat 24 . 2 are formed by holding means with a U-shaped cross-section. In this case, a clamping profile 27 is respectively inserted into the U-shaped holding bracket.
[0108] FIG. 7 shows schematically another embodiment of a holder 22 . The first holding arm 22 . 1 and the second holding arm 22 . 2 , particularly the first groove-like seat 24 . 1 and the second groove-like seat 24 . 2 are formed in this embodiment by a holding bracket 28 , with an L-shaped cross-section, and a compression plate 26 supported in an adjustable fashion in reference to a holding bracket 28 .
[0109] The compression plate 26 is supported in a fashion adjustable from a default position ( FIG. 8 a ) by the force of a return spring (spring 29 ) into an seat position ( FIG. 8 b , FIG. 8 c ), in which the two angular abutting edge sections of the device 23 are seated, when the device 23 is connected to the handheld robot operation unit 15 ( FIG. 8 b , FIG. 8 c ) by the first holding arm 22 . 1 and the second holding arm 22 . 2 , particularly the first groove-like seat 24 . 1 and the second groove-like seat 24 . 1 in a formfitting and/or force fitting fashion.
[0110] The first holding arm 22 . 1 and the second holding arm 22 . 2 , particularly the first groove-like seat 24 . 1 and the second groove-like seat 24 . 2 have a stop area 30 , which is designed for contacting a front of the device 23 in an seat arrangement ( FIG. 8 b , FIG. 8 c ) of the device 23 at the handheld robot operation unit 15 , and the compression plate 26 is designed for contacting at a rear of the device 23 , with the compression plate 26 being supported, in order to seat differently thick devices ( FIG. 8 b , FIG. 8 c ) adjustable in reference to the stop area 30 . The compression plate 30 is supported in the exemplary embodiment of FIG. 7 and FIG. 8 a to FIG. 8 c linearly adjustable in reference to the stop area 30 .
[0111] In a variant here the adjustable compression plate 26 is supported in a linearly adjustable fashion together with the handle-like grip section 16 a , as shown schematically in FIG. 9 .
[0112] In another variant the adjustable compression plate 26 is supported linearly adjustable in reference to the stop area 30 and in reference to the handle-like grip section 16 a , in particular the handle-like grip section 16 a is fastened rigidly in reference to the stop area 30 , as shown schematically in FIG. 10 .
[0113] In FIG. 11 it is shown schematically how the first holding arm 22 . 1 and the second holding arm 22 . 2 , particularly the first groove-like seat 24 . 1 and the second groove-like seat 24 . 2 , have a clamping profile 27 made from an elastic material.
[0114] FIG. 12 shows schematically, how differently designed clamping profiles 27 or also a hollow-chamber profile 27 a made from an elastic material can be inserted into the first groove-like seat 24 . 1 and/or the second groove-like seat 24 . 2 and can also be removed therefrom. For example, different clamping profiles 27 or hollow-chamber profiles 27 a can be used depending on the device 23 respectively selected for insertion.
[0115] FIG. 13 shows an embodiment variant, in which the clamping profiles 27 are used combined with a compression plate 26 and a stop area 30 in the corner section 24 of the holder 22 , in which the compression plate 26 is pre-stressed by a spring 29 into a clamping position.
[0116] FIG. 14 shows an embodiment variant, in which the compression plate 26 is supported pivotally in reference to the stop area 30 . The two springs 29 are designed as torsion springs, and pivot the compression plate 26 against the stop areas 30 .
[0117] FIG. 15 shows a variant in which a hollow-chamber profile 27 a can be expanded via a fluid, particularly compressed air, in order to generate a clamping force.
[0118] According to such a variant the handheld robot operation unit 15 may have a fluid reservoir 31 and/or a fluid pump 32 . Via the fluid pump 32 the fluid can be pumped into at least one hollow chamber 33 of the hollow chamber profile 27 a , so that the hollow chamber profile 27 a can enlarge, allowing the first groove-shaped seat 24 . 1 and/or the second groove-shaped seat 24 . 2 to constrict.
[0119] FIG. 16 shows a mobile robot platform 34 on which a robot arm 35 is fastened. Via a holder both a handheld robot operation unit 15 according to the invention, as well as a device 23 can be held at the mobile robot platform 34 in a manually detachable fashion.
[0120] FIG. 17 shows a control base 36 on which a robot arm 35 is fastened. Via a holder a handheld robot operation unit 15 according to the invention can be held at the control base 36 in a manually detachable fashion. For this purpose, the control base 36 may have an edge 37 like the edge of a table, at which the handheld robot operation unit 15 according to the invention can be clamped with its holder 22 according to the invention as described and claimed.
[0121] When the handheld robot operation unit 15 according to the invention is removed manually from the control base 36 , for example, and held as a separate handheld robot operation unit 15 in the hand of the user, this separately held handheld robot operation unit 15 forms an autonomous 6D-mouse, by which the user can directly and manually guide the robot arm 35 or also the mobile robot platform 34 by moving and/or rotating the hand and/or the wrist. For example, for this purpose the positions and/or alignments of a reference point, particularly TCPs of the robot arm 35 and/or the mobile robot platform 34 can be coupled to the positions and/or alignments of the handheld robot operation unit 15 held manually. A movement of the hand and/or the handheld robot operation unit 15 held manually causes here directly a respective equivalent motion of the robot arm 35 or the mobile robot platform 34 .
[0122] FIG. 18 shows a robot arm 35 . Via the holder 22 a handheld robot operation unit 15 according to the invention can for example also be fastened at a flange 38 of the robot arm 35 in a manually detachable fashion. For this purpose, the flange 38 may show an edge, at which the handheld robot operation unit 15 according to the invention can be clamped with its holder 22 according to the invention, as described and claimed. In the clamped arrangement of the handheld robot operation unit 15 at the flange 38 can the robot arm 35 then be guided, for example manually, and its joints can be adjusted by a manual guidance of the handheld robot operation unit 15 .
[0123] FIG. 19 and FIG. 20 show two variants of handheld robot operation units 15 , each respectively with an actuating means 39 arranged at the handle-like grip section 16 a , which is designed to hold the holder 22 in a clamped position in a locking stage of the actuating means 39 and in an unlocking stage of the actuating means 39 releasing the holder 22 from its clamped position.
[0124] Pairing of the handheld robot operation unit 15 with the device 23 can for example occur by NFC and/or RFID-technologies known per se to one trained in the art by a simple holding together and/or plugging together of the respective partners.
[0125] An actuating means and/or a trigger, such as the locking means 39 , may particularly be integrated at the handle, however it may for example also rest separately on a corner of the device 23 and thus be arranged intentionally separated from the handle. This way, an intentional triggering is necessary and desired with a hand different from the holding one. Here, the actuating means may serve, in combination with a specially formed environment, also as a handle for the one-handed holding during the coupling process.
[0126] By a special design of the second leg 16 . 2 this may also be grasped. A second enabling key located underneath thereof, for example, can allow forming a second holding variant. The right hand here grasps the leg 16 . 2 , the left hand grasps the left edge of the tablet. This way, the holding position of the device 23 can also be changed arbitrarily, particularly according to ergonomic aspects.
[0127] When holding the handheld robot operation unit 15 the top of the hand may rest on the bottom of the central plate. This allows a relaxed holding. When a tablet PC is integrated, it rests with the corner/bottom facing away from the handheld robot operation unit 15 on the lower arm of the user. This allows a relaxed holding with the tablet.
[0128] While the present invention has been illustrated by a description of various embodiments, and while these embodiments have been described in considerable detail, it is not intended to restrict or in any way limit the scope of the appended claims to such detail. The various features shown and described herein may be used alone or in any combination. Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and method, and illustrative example shown and described. Accordingly, departures may be made from such details without departing from the spirit and scope of the general inventive concept.
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A handheld robot operation unit includes a housing having a handle-like grip section, a basic safety control device arranged in the housing, and at least one holder connected to the housing and configured for manually detachably coupling the housing to a device that is different from the handheld robot operation unit and which electronically communicates with the basic safety device. The holder includes a first holding arm for mechanically connecting the handheld robot operation unit to a first edge section of the device, with an opposite edge section of the device being free. A second holding arm is configured to mechanically connect the handheld robot operation unit to a second edge section of the device, adjacent the first edge section and forming a corner section of the device, with an edge section of the device opposite the second edge section being free. A corresponding method is disclosed.
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BACKGROUND OF THE INVENTION
The present invention relates generally to tape cassette loading mechanisms, and particularly to a mechanism for loading cassettes into a tape drive from a multi-cassette magazine.
Magnetic tape may be used to store data, both as the primary storage means and as a backup to data normally stored on disk. Digital audio tape (DAT) cassettes originally developed for audio applications have been found useful for this purpose because of their small size and large storage capacity. Conventional DAT drives are adapted to receive a single DAT cassette at a time, either to play its contents or to record data thereon. Although DAT cassettes have a relatively sizable storage capacity, the amount of data which it is desired either to access or to back up continues to increase. It would clearly increase the usefulness of a DAT drive if it could be augmented with a cassette changer which would automatically load any one of a number of cassettes stacked in a single magazine. A group of such stacked DAT cassettes could provide an extremely large library of information or, where used as a backup, could multiply manifold the data that can be backed up by an unattended DAT drive. The present invention provides a loading mechanism capable of inserting DAT cassettes from a common magazine into a DAT drive and a magazine for holding DAT cassettes which is uniquely adapted for that purpose.
SUMMARY OF THE INVENTION
In accordance with the invention, use is made of an exterior recess along one of the walls of the typical DAT cassette in the process of loading and withdrawing the cassette from a tape cassette drive. The inventive loading mechanism includes a magazine having at least one, and typically a plurality of, chamber(s) for holding a tape cassette, the chamber(s) having front and rear openings. The magazine is positioned with a chamber opposite the tape drive inlet. Latching means, such as a latch, and a pushing means are held in a resting position outside of the chamber so positioned. The pushing means is adapted to force the cassette out of the chamber through its rear opening into the drive inlet, and the latch is adapted to hook into the exterior recess of the cassette held in the positioned chamber to pull a cassette ejected from the drive inlet back into the chamber. The pushing means and the latch are driven by means external to the magazine from their resting position outside of the positioned chamber, into that chamber through its front opening. Within the chamber, they are moved first toward and then away from the tape cassette drive, the pushing means being operative to move the cassette into the cassette drive from the positioned chamber, and the latch being operative to pull the cassette from the cassette drive into the positioned chamber through its rear opening.
In its preferred embodiment, the magazine chamber has a floor and a ceiling, one of which is faced by the recess in the cassette when the cassette is inserted in the chamber. A slot runs the length of the floor or the ceiling (whichever faces the cassette slot, but hereafter assumed to be the floor). The slot has ramps near its opposite ends. Preferably, the slot comprises a shallow central region and two deeper terminal regions at its opposite ends, next to the front and rear openings of the chamber. As the pushing means presses against the cassette in the positioned chamber, the latch enters the slot at its deep end in the front of the chamber with sufficient clearance to engage the recess in the cassette. Thereafter, the latch rides up on the front ramp onto the shallower central region of the chamber slot, where it enters the cassette recess.
When the cassette is about to be ejected from the chamber into the tape drive, the latch rides onto the ramp near the rear opening of the positioned chamber, allowing it to ride away from the cassette in the chamber so as to exit from the cassette recess, thereby allowing the cassette to be ejected from the positioned chamber. Subsequently, when the cassette is ejected from the tape drive back into the positioned chamber, the process is reversed by retracting the latch into that chamber, and, by the action of the ramps, the latch may be made to reenter and reengage the recess of the ejected cassette, pulling it back into the positioned chamber, after which the latch, by riding along the front ramp, may be disengaged from the cassette and withdrawn from the magazine.
In further keeping with the invention, the means for driving the pushing means includes a scissors mechanism, having an output arm driven at one end and carrying the pushing means at its opposite end into a cassette-holding chamber when the scissors mechanism is extended, and carrying the pushing means out of the chamber when the scissors mechanism is retracted. Because of the linkages which exist between the arms of the scissors mechanism, the pushing means carried by the free end of the mechanism's output arm is moved in a straight-line motion against the cassette in the holding chamber, preventing the cassette from being cocked to one side or another and thereby jamming in the magazine as it is being pushed. Both the output arm of the scissors mechanism and a link connected to the output arm are dimensioned to fit into a cassette-holding chamber in the magazine, yet occupy a minimum lateral space when fully retracted.
The latch by which the cassette is pulled from the cassette drive is biased away from engagement with the cassette recess so that it will move away from such engagement, except when pressed into engagement by being positioned between the cassette and the floor of the magazine chamber in which the cassette is held. Due to the action of the biasing means, the latch is forced out of engagement with the cassette when it enters and leaves the magazine chamber floor slot at its front and rear ramps. According to one variation of the invention, the latch is biased away from engagement with the cassette recess by being rockably mounted on the pushing means with a compression spring between the two, so as to cause the latch to ride along the front and rear ramps to engage and disengage the cassette recess. In accordance with another variation of the invention, biasing of the latch is accomplished by a constant-force spring, whose spiral configuration causes it to exert a force upon the latch away from the cassette and toward the floor of the magazine chamber containing the cassette. In the latter version, the constant-force spring also serves to help orient the latch in a direction parallel to its line of motion.
BRIEF DESCRIPTION OF THE DRAWINGS
These features and advantages of the invention, as well as other features and advantages of the invention, will be more apparent from a reading of the claims and of the detailed description of the invention in conjunction with the drawings described below.
FIG. 1 is a plan view of a magazine constructed in accordance with the present invention;
FIG. 2 is a front view of the magazine of FIG. 1;
FIG. 3 is a side view of the magazine of FIG. 1;
FIG. 4 is a perspective view of one of the shelves of the magazine of FIG. 1;
FIG. 5 is a plan view of the shelf illustrated in FIG. 4;
FIG. 6 is an end view of the shelf illustrated in FIG. 4;
FIG. 7 is a cross-section through the shelf illustrated in FIG. 4, taken along lines 7--7 in FIG. 5;
FIG. 8 is a perspective view of a subassembly of the cassette loader of the present invention, showing the cassette pushing and pulling devices mounted on a scissors mechanism;
FIG. 9 is a view in front elevation of the cassette loading mechanism;
FIGS. 10A-10G are a series of plan views of the cassette loading mechanism, showing it in a time sequence from the time that a cassette is first engaged in a magazine, through the time when it is ejected from the magazine into a tape drive to the time when it is recaptured in the magazine from the tape drive and returned to its original position;
FIGS. 11A-11I are a series of cross-sectional views showing the mechanism illustrated in plan view in FIGS. 10A-10G through the same sequence, sometimes at slightly different moments in time;
FIGS. 12A-12H are a series of cross-sectional schematic views of an alternative embodiment of the invention utilizing a constant-force spring;
FIG. 13 is an enlarged portion of FIG. 12A showing the latch parked on its ledge;
FIG. 14 is an enlarged portion of FIG. 12E showing the latch biased away from a cassette by the constant-force spring when the scissors mechanism is fully extended; and
FIG. 15 is a block schematic diagram of selected sensors which control movement of the magazine past the tape drive's inlet, and which also control the scissors mechanism in response to sensed positions of the scissors mechanism and sensed movements of a cassette.
DETAILED DESCRIPTION
A magazine constructed in accordance with the invention is illustrated in FIGS. 1-7. Constructed, preferably of high-strength injection-molded polycarbonate, with its shelves, which form spring tabs, possessing a high degree of elastic memory, the magazine 11 comprises a pair of side members 13 and 15 and top and bottom members 17 and 19, arranged in a rectangular configuration. The side members 13 and 15 have rearwardly-extending slots 21, with slots of one being aligned with corresponding slots in the other to permit photoelectric monitoring of cassettes within the magazine. Extending outwardly from both of the side members 13 and 15, in an L-shaped configuration, are front rails 25 having serrated tracks 26 on their front surfaces. Second rails 27 extend parallel to the front rails 25 toward the rear of the magazine 11 and, as will be seen, ride on a bearing surface of an elevator shaft. Extending between the front and rear rails 15 and 27 are a series of ribs 23 separated by spaces 29. The spaces 29 serve to provide a path for the light beam of an emitter/detector pair, located in the apparatus within which the magazine is transported, to keep track of the magazine's location therein. Stacked between the floor and ceiling members 17 and 19 are a series of identically-configured shelves 31, each pair of shelves defining a chamber 32 of the magazine 11. The shelves 31 are retained in the side members 13 and 15 by means of grooves therein (not shown).
As is best seen in FIGS. 4-7, each shelf has a generally-rectangular configuration and is of even thickness, except for variations that will be described. A pair of ears 33, extending from either side of the shelf 31, serve to key the shelf within the shelf-retaining grooves (not shown) in the side members 13 and 15. Also, for purposes of assembly, the front edge of the shelf extends outwardly on either side, as shown at 36, fitting against corresponding transitional surfaces 38 near the front of the side members 13 and 15.
Formed in either side of the shelf 31 and extending from the vicinity of the ears 33 are a pair of identical resilient tabs 35. Each of the tabs has a groove 37 near its fixed end, for greater resiliency, and a downwardly-extending projection 41 terminating in a face 43, which protrudes from the bottom planar surface 46 of the shelf 31. The tabs 35 serve to prevent incorrect insertion of cassettes into the magazine.
The top planar surface 45 of the shelf 31 is broken by a central slot 47 running front to back. The slot 47 has a shallow central region 49 and deep front and rear regions 51 and 53. Ramp 55 provides a gradual transition from the front deep region 51 to the shallow central region 49 of the slot 47, and a second ramp 57 provides a similar transition from the central slot region 49 to the rear deep slot region 53.
Cut through the center of the shallow central slot region 49 is a U-shaped channel 59, which terminates near the interface of the rear ramp 57 and the rear deep slot region 53. The portion of the shelf defined by the U-shaped channel 59 forms a cantilevered tongue 61 (see FIGS. 4, 5, and 7) having a bump 63 at its end which protrudes beyond the bottom planar surface 46 of the shelf 31. The tongue 61 serves as a resilient retention means for a cassette inserted in a chamber whose roof is formed by the shelf 31.
A cassette loading-and-unloading apparatus 67 will be described with reference to FIG. 8, showing a subassembly containing a cassette pushing-and-pulling mechanism 8, and with reference to FIGS. 10A-10G, which show the cassette loading apparatus in plan view during successive steps of its operation, as well as with reference to FIGS. 11A-11I, showing the same mechanism in cross-section during successive steps of its operation. For sake of clarity, in FIGS. 10A-10G the magazine 11 is shown with its ceiling member 19 removed so as to reveal the successive locations of a cassette 161 in its top chamber 32.
Turning to FIG. 8 first, the cassette pushing-and-pulling assembly is mounted on a U-shaped bracket 67 having a central panel 69 and a pair of arms 68 and 70. The principal elements carried by the bracket 67 are a scissors assembly 73; a motor 75 for driving the scissors assembly; pushing means, in the form of a cap 77; and latching means, in the form of a latch 79. The cap and latch 77, 79 are carried by the scissors assembly 73 and serve as its pushing and pulling implements. The motor 75 may be a conventional micromotor, mounted on a bracket 81, which in turn is carried by a ledge 85 attached to the central panel 69. Coupled to the output shaft of the motor 75 through a microgear 76 is a lead screw 87, which is driven by the motor 75 through the microgear at a lower RPM than that of the motor 75.
The lead screw is anchored at its non-driven end by a collar 89 in a hole 91 in the bracket arm 68. Carried on the lead screw 87 is a lead screw nut 97, in the form of a block. Comprising the scissors mechanism are a pair of links 93 and 95. The link 93, having a stepped configuration, is rotatably mounted at its upper end (as seen in FIG. 8, wherein movements will be referred to with reference to the X, Y, and Z axes as illustrated thereon) by means of a screw 99 on a ledge 83. At its opposite, lower end, the link 93 is rotatably coupled to the long arm 95, at its midpoint, by a screw 101. The scissors' long arm 95 is pivotably mounted at one of its ends for rotation about the lead screw nut 97 by a screw 103 rotatably fastening the arm 95 to the lead screw nut 97.
The lead screw nut 97 rides, in the Z direction, upon a rail 105 mounted on the bracket panel 69 (see FIG. 10A). The nut 97 is driven by the lead screw 87, which extends through it, so that the scissors mechanism 73 may be extended and retracted under the force of the motor 75 transmitted through the lead screw 87, and its nut 97 to the long scissors arm 95 attached to the nut. Significantly, the free end of the long arm 95 moves in a straight line in the X direction.
When the scissors mechanism 73 is fully retracted, the latch 79 rides onto the ledge 85. As seen in FIG. 11A, the cap 77 is mounted on a bent finger 141, which extends from the long scissors arm 95. A slot 143 in the cap 77 receives the finger 141. A hole 145 in the cap, threaded at its end and countersunk at its inlet, receives a threaded bolt 149, which extends through a hole 146 in the finger 141 in alignment with the hole 145 in the cap 77. The latch 79 is rockably mounted relative to the long scissors arm 95 by placing it between the head of the bolt 149 and a compression spring 147, and then screwing the bolt 149 into the cap 77 so that the compression spring 147 is received by the countersunk inlet of the ca hole 145. The cap is thus securely and firmly mounted on the finger 141, while the latch 79 is free both to rock and to rotate relative to the cap 77 from which it is biased away by the compression spring 147.
Mounted above the ledge 85 (FIG. 8) is a microswitch 111, whose purpose it is to sense when the scissors mechanism 73 has been fully retracted. In that position, shown in FIG. 10A, the tail 151 of the latch 79 (shown in FIG. 11A) is pressed against the microswitch 111 so as to actuate it. A similar microswitch 107, visible in FIG. 10B, mounted below the ledge 85 and facing toward the nut 97, serves to sense the fully-extended condition of the scissors mechanism 73. For that purpose, the nut 97 carries a screw 109 in line with the microswitch 107, which may be adjusted so that the motor 75 may be stopped when the long arm 95 has reached a previously determined, precise position along its travel in the X direction, toward the DAT drive inlet.
Beginning with FIG. 10A, there will be described the remainder of the loading and unloading apparatus 7, for loading a tape cassette into the inlet 9 of a DAT drive. The apparatus 7 is contained within a frame 113, to which the bracket 67 of the push/pull mechanism is attached. The frame 113 is, in turn, attached to the front of a DAT tape drive, whose front surface 100 is closely spaced from the rear of the apparatus 7. Extending upright, near the rear, are a pair of elevator posts 115 and 117, capped by guide blocks 112. Between them, the posts 115, 117 define part of an elevator shaft, within which the magazine 11 is raised and lowered. The guide posts 115, 117 have flat bearing surfaces 114, on which the magazine rear rails 27 ride in the Y direction. The guide blocks 112 have slots 121, slightly V-shaped in the Y direction, to guide the magazine rails 27 into position.
Spaced from the posts 115, 117, a pair of rubber drive rollers 125 and 127 are mounted on a powered shaft 128. The powered shaft 128 is journaled in the frame 113 for rotation and carries a driven gear 129 and a driving sprocket 135. The driven gear 129, in turn, is engaged to be driven by a gear 131, which is mounted for rotation about the Y axis and which, in turn, is driven by a micromotor 133. A second pair of rubber rollers 119 and 120 (FIG. 9) are carried by a second, driven, shaft 130. A driven sprocket 132, coupled to the driving sprocket 135 by a drive belt 134, completes the power train to the lower pair of rollers 119, 120, so that the magazine 11 is driven by all four rollers 119, 120, 125, and 127, powered by the motor 133. Under the control of an emitter/detector pair 140, 142, located on either side of the series of ribs 23 which extend from the side of the magazine 11, motor 133 is made to position a selected one of the chambers 32 opposite the DAT drive inlet 9.
As the magazine 11 is pushed down into place, its front tracks 26 press first against the upper drive rollers 125, 127 and then against the lower drive rollers 119, 120. The rollers 125, 127, 119, and 120, in turn, press the magazine rear rails 27 against the bearing surfaces 118 of the posts 115, 117. Mounted next to the post 117 is one element 118 of a photoemitter/detector pair, and mounted next to the other post 115 is another element 116 of the pair, to permit sensing of the ejection of a cassette from the DAT drive into the magazine chamber 32, which is then in line with the DAT drive inlet 9. A second emitter/detector pair 136, 138 is positioned at the same elevation (along the Y axis) as the pair 116, 118, but farther from the DAT drive face 100. They serve to detect when the pusher cap 77 is in its forward, parked position, signalled by the breaking of a light link between the pair 136, 138 through a pair of the magazine rear slots 21. The magazine 11 is shown with the top one of its chambers 32 aligned with the DAT drive inlet 9, in FIGS. 10A-10E and in FIG. 11D. The same position is illustrated in FIGS. 11A-11I, but, for simplicity, the DAT drive inlet 9 does not appear in all of them. Suffice it to say that a common plane B--B (FIG. 11A) extends through the scissors mechanism 73, the DAT drive inlet 9, and the chamber 32 positioned between them. A significant advantage of the magazine 11 is that it is easily lifted out of its elevator and replaced by another magazine.
Referring particularly to FIG. 11A, a DAT cassette 161 is shown fully recessed in the chamber 32 of the magazine 11. The cassette 161 comprises a body 163, on which is mounted a sliding cover 165. A small detent 166 in the top of the cassette body 163 receives the enlarged end 63 of the retaining tongue 61 which depends from the shelf 31 forming the roof of the chamber 32. Mounted on the rear of the cassette body 163 is a hinged tape cover 167. The DAT cassette which is illustrated is a standard product whose cover 165 is spaced from a lip 166 at the front of the cassette, to form a recess 171. When the DAT cassette is inserted into a DAT drive, the sliding cover 165 slides toward the front of the cassette into the clearance formed by the recess 171, bringing a pair of windows (not shown) into alignment with the hubs of the supply and take-up reels inside the cassette. At the same time, the hinged cover 167 swings up, exposing the tape to magnetic read/write heads. In its closed condition, where the covers 165 and 167 are as shown, the cassette is a fully enclosed and protected package and provides the recess 171 upon which, in its preferred embodiment, the present invention relies to enable the cassette to be withdrawn from the DAT drive in a manner to be described next.
As shown in FIG. 11A, the latch 79 is formed, in its preferred embodiment, in the shape of a hook having a tail 151, an anchor 153, an intermediate sloping section 155, a slide portion 157, and a tip 159. The cap 77 and latch 79 are shown immediately adjacent the front of the magazine 11, where they are positioned by the fully retracted scissors mechanism 73. The latch 79 rests on the ledge 85, in which it is aligned to be in line with the central slot 47 of the shelf 31. For this purpose, the ledge 85 is provided with upright (in the X-Y plane, as viewed in FIG. 8) walls 85a and 85b, which flare outwardly at 85c and 85d to receive, and then orient, the latch 79 on the ledge 85.
When it is desired to insert the cassette residing in the chamber 32 opposite the DAT drive inlet 9, a signal is sent to the motor 75, causing the scissors mechanism to begin to move toward its extended position. The latch 79 enters the chamber 32, its tip 159 clearing the space between the bottom of the DAT cassette 161 and the front deep slot portion 51. As the scissors mechanism continues to progress, the latch tip 159 rides up the front ramp 55 into the space between the bottom shelf 31 and the cassette 161 provided by the cassette recess 171. It will be noted that the height of the latch tip 159 must not exceed the depth of the shelf slot front region 51 and that the ramp 55 must be far enough away from the front end of the shelf 31 to permit the latch tip 159 to clear the cassette front lip 166.
In FIG. 11C, the cap 77 is shown to have engaged the cassette 161, which begins to be pushed by the cap toward the rear of the magazine chamber 32 and into the DAT drive inlet 9. The latch tip 159 is inside the cassette recess 171, and the latch slide portion 157 has entered the shallow central portion 49 of the shelf slot 47. Due to the proximity of the ledge 55 to the magazine shelf 31, the latch slide portion 157 transits from the ledge 85 to the shelf slot 47 without losing its orientation acquired in the ledge. The width of the latch slide 157 is matched to fit closely within the slot region 49 so as to keep the latch 79 aligned within the slot 47. The thickness of the latch slide 157 is matched to the depth of the slot shallow portion 49 so as to be fully recessed therein, or at least sufficiently so as not to interfere with the movement of the cassette 161. The height of the latch tip 159 ensures that, being sandwiched between the cassette 161 and the shelf slot shallow portion 49, the latch 79 will firmly engage the cassette, and particularly its front lip 166, when the latch is subsequently retracted.
Movement of the cap 77 and latch 79 toward the rear of the magazine 11 continues, with two successive positions of the cassette being illustrated in plan view in FIGS. 10B and 10C.
The next notable event is depicted in FIG. 11D, when the latch is about to descend the rear ramp 57. Shortly thereafter, as shown in FIG. 11E, the bend in the latch joining its portions 155 and 157 reaches the ramp 57 and begins to ride down the ramp, which results in the latch rocking about its mounting bolt 149. The latch slide portion 157 is nearly fully on the rear terminal portion 53 of the slot 47, and the tip 159 of the latch has moved out of the way of the cassette lip 166. This prepares the way for the next event, shown in FIG. 11F, where the cassette 161 has traveled far enough into the DAT drive inlet 9 to cause the DAT drive to grab the cassette and move it out of the magazine 11. The latch 79 has, by this time, moved beyond the rear of the shelf 31 and protrudes slightly from the magazine 11. This fully-extended position of the scissors mechanism 73 is sensed by the microswitch 107, in response to which, by appropriate electronic controls, shown and later described with reference to FIG. 15, the motor 75 is reversed, causing the scissors drive 73 to begin to retract, pulling the latch 79 back into the magazine 11 to assume the position shown in FIG. 11G, where it is parked until the cassette 161 is ejected from the DAT drive inlet 9. The "parked" position of the latch 79 is sensed by reestablishment of the previously broken light path between the emitter/detector pair 136, 138 by the pusher cap 77, causing the motor 75 to stop with the latch in that (parked) position.
The cassette 161 is shown in FIG. 11G as being ejected from the DAT drive into the magazine chamber 32. When the front end of the cassette 161 crosses the gap between the DAT drive face 100 and the magazine 11, the second emitter/detector pair 116, 118 senses the presence of the cassette 161 and, through the same electronic controls as are associated with emitter/detector pair 136, 138 restarts the motor 75. This causes the latch 79 to remount the rear ramp 57 and to pivot about the tip of its tail 151, whereby the latch tip 159 enters the cassette recess 171, engages its front lip 166, and pulls the cassette with the receding arm 95 of the cassette mechanism. In this manner, the cassette 161 continues to be withdrawn from the DAT drive until the latch tip 159 again reaches the front ramp 55, whereupon the latch 79 slides away from the cassette 161, out through the gap between the cassette lip 166 and the shelf ramp 55, and onto the ledge 85, where it is parked. This marks the full retraction of the scissors mechanism 73, sensed by the microswitch 111. In response thereto, through the action of the aforementioned electronic control, the motor 75 is stopped. The positions of the mechanism depicted in FIGS. 11F and 11G are respectively illustrated in plan view in FIGS. 10D and 10E. FIG. 10G shows in plan view the position corresponding to that illustrated in cross-section in FIG. 11I. FIG. 10F illustrates the mechanism at an intermediate point between the positions depicted in FIGS. 11G and 11H.
It will be understood that, as used herein, "floor" is an arbitrary designation used in the context of equipment that is upright, as shown. Therefore, regardless of the orientation, the term "floor" as used herein shall be understood to designate the shelf 31 toward which the cassette slot 171 faces, and that the latch 79 always travels between the cassette 161 and the shelf faced by its slot 171.
Certain geometric relationships among the locations of the DAT drive inlet 9, the chamber 32 which is positioned next to it, the cap 77, the scissors arm 95, the link 93, and its pivot point defined by the center of the screw 99, are worth noting. The chamber 32 is rectangular in cross-section and is symmetrical about a center plane A (FIG. 10A), which lies in the X-Y plane. The pivot point about which the link 93 is anchored by the screw 99 to pivot, lies in the plane A adjacent the front opening of the chamber 32. A second plane B (FIG. 11A), which is orthogonal to the first plane A and which extends along the X and Z axes (FIG. 8), extends through the DAT drive inlet 9 and through the chamber 32 positioned opposite the inlet. It is along the intersection of the A and B planes that the cap 77 is pushed by the output arm 95 through the positioned chamber 32 toward, and away from, the DAT drive inlet 9. It is because of this straight-line motion of the means which contacts the cassette 161 (in this case, the front end of the cap 77) that the cassette 161 may be pushed without cocking it to one side or another, which might cause it to bind in the magazine chamber 32.
It will be seen from the foregoing that the slot 47, by virtue of its configuration, functions as a camming surface, and that the tail and slide portions 157 of the latch 79 function as cam followers, which are guided by the surfaces of the cam to move the latching tip 159 into engagement with the cassette recess 171, and, under the urging of the biasing means 147, which normally urges the latching means away from engagement of its latching tip 159 with the cassette recess 171, to guide the latching tip 159 out of engagement with the cassette recess 171.
Operation of the system may be best summarized with reference to FIG. 15, showing the control 173 connected to the motor 75 and receiving inputs from the detectors 118, 138 and 142 and from microswitches 107 and 111. In response to a "select" signal 172 to the control 173, indicating which chamber 32 is to be positioned opposite the DAT drive inlet 9, the motor 133 drives the magazine 11 until the magazine is sensed, by means of the emitter/detector pair 140, 142, to be in the proper positions relative to the DAT drive inlet 9. In response to a "start" signal 175, the control 173 activates the motor 75, causing the scissors mechanism 73 to begin to advance. After the cassette 163 has been grabbed by the DAT drive out of the magazine 11, the scissors mechanism 73 continues to advance until its fully-extended position is sensed by the microswitch 107. The control 173 is programmed to reverse the motor 75, withdrawing the long arm 95 until the latch 79 is sensed by the emitter/detector pair 136, 138, which senses interruption of light between the pair by the presence of the cap 77. This represents the "wait" position of the cap and latch 77, 79, as shown in FIG. 11G. When the cassette 161 is ejected from the DAT drive inlet 9, the event is sensed by the emitter/detector pair 116, 118, which cause the control 173 to reactivate the motor 75, initiating the retraction of the long arm 95 and with it, the cassette 161, until the scissors mechanism is fully retracted, as sensed by the microswitch 111, which, through control 173, stops the scissors drive motor 133.
FIGS. 12A-12E, 13, and 14 illustrate an alternative embodiment of the invention which may be similar to the embodiment illustrated in FIGS. 10 and 11, with the principal difference being that the latch is differently configured and is supported at the end of a constant-force spring 201. In the alternative embodiment illustrated in FIGS. 12A-12E and in FIGS. 13 and 14, a constant-force spring 201 is mounted next to and below the ledge 85. Welded to the end of the spring 201 is a latch 207, which may be made of spring steel. In this embodiment, the latch may be more simply configured, 207a extending at right angles from the body 207a.
A post 203 is pinned to the spring and latch 201/207 so that the three elements (spring/post/latch 201/203/207) are rigidly attached, with the post 203 at substantially right angles to the hook 207. Of course, due to the flexibility of the spring 201, the hook 207 is movable between the two positions shown in FIGS. 12 and 13 respectively. In this respect, it is noted that the post 203 extends through a hole 95b in the modified long arm 95a of the scissors mechanism, which may be identical to that illustrated in FIG. 8 except for the modification that the long arm 95a is straight, with the hole 95b at its end, rather than having the bent finger 141 at its end, as shown in FIG. 11A, for example. For reasons which will become immediately apparent, the hole 95b is sufficiently large to allow the post to rock inside the hole. A retaining clip 205, at the end of the post, may be provided to ensure that the post remains in the long arm 95a at all times.
The initial position of the modified push/pull mechanism is shown in FIG. 12A. The arm 95a is fully retracted, and the hook 207 rests on the ledge 85 next to the magazine 11. As is best seen in FIG. 13, the post 203 rests upright n the arm hole 95b. When the arm 95a begins to advance toward the magazine 11 (FIG. 12B), the natural bias of the constant-force spring urges the latch 207 against the ledge 85 and the bottom of the shelf slot 47. Furthermore, since the latch 207 is welded to the end of the spring 201, the latch is kept in alignment such that its longitudinal axis is at right angles to the cassette recess 171. Indeed, since the latch 207 is thus kept in its desired orientation, it need no longer rely on the slot 47 in the shelf 31 to keep it in alignment as was the case with the first-disclosed embodiment. So, whereas, in the first-disclosed embodiment, the latch 207 is biased away from the cassette 161 and against the shelf 31 by the compression spring 147 and is aligned in its desired orientation by means of the slots in the ledge 85 and the magazine shelf 31, in the second embodiment both the biasing and aligning functions are performed by the same element--the constant-force spring 201.
As the long arm 95a continues to advance by operation of the scissors mechanism, in the same manner explained with respect to the first embodiment (FIGS. 10 and 11), the latch 207 rides up the front ramp 55 and enters the cassette front recess 171 as before. The front end of the long arm 95a of the scissors mechanism 73 directly abuts the cassette 161 and begins to push it toward the DAT drive inlet 9 (FIGS. 12B, 12C). When the arm 95a reaches the rear end of the magazine 11 (FIGS. 12D, 12E), the latch 207 is biased away from the cassette 161, as particularly shown in FIG. 14, by the force of the constant-force spring 201. In this position, the post 203 is tilted within the long arm hole 95b, and the latch 207 rests against the rear sloping surface 57 of the shelf 32. Because of the different configuration of the latch 207, and because it is now biased away from the cassette 161 by the constant-force spring 201 rather than by the rocking action of the rear ramp 57, the ramp 57 may simply assume a curved lip shape, as shown in FIGS. 12A-12H and in FIG. 13. The cassette 161 is now in the DAT drive. When the cassette 161 is thereafter ejected back into the magazine 11 (FIG. 12F), ejection of the cassette is sensed in the same manner as described previously. The motor 75 is activated and withdraws the long arm 95 and with it, the latch 207. The latch 207 then rides back up the shelf slope 57, reenters the cassette slot 171 (FIG. 12F), pulls the cassette 161 back into the magazine chamber 32 (FIG. 12G), and escapes the cassette recess 171 by sliding back down the front ramp 55 and back onto the parking ledge 85 (FIG. 12H).
In summary, there has been provided a cassette loading and unloading apparatus by which a selected one of a plurality of cassettes may be inserted into and received from a DAT cassette drive. By virtue of its scissors-driven push-pull mechanism, the apparatus is compact, since not much additional lateral space is required for the scissors drive when it is fully retracted, in front of the cassette magazine from which it loads and unloads cassettes. Forming an important part of the loading and unloading apparatus is the novel scissors mechanism, which combines compactness with straight-line motion, allowing it to push cassettes out of the magazine without tilting them. Combined with the scissors mechanism, in accordance with another feature of the invention, is the provision of a biased latch adapted to hook into the recess which is characteristic of DAT cassettes.
A further inventive aspect of the invention is the provision of the magazine with its uniquely-configured shelves with which the latch cooperates to enter and leave the cassette recess with which the latch cooperates to pull it from the DAT drive inlet. While in its preferred mode, the latch is biased by means of a compression spring, an alternative version, pursuant to which the latch is both biased and aligned by means of a constant-force spring which is unwound as the scissors mechanism extends into the magazine chamber holding a cassette, is also disclosed.
All aspects of the invention have been described in the context of a DAT cassette. It will be understood that the invention is not limited to the handling of that type of cassette, but that it would be equally suitable for use with any cassette which has a recess along its side similar to the recess characteristic of DAT cassettes.
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A cassette loader for a DAT cassette drive includes a specially-constructed, multi-chamber magazine which rides in an elevator to bring selected ones of a plurality of cassettes in the magazine into operative alignment with the inlet of the DAT cassette drive. A push-pull mechanism is positioned at a distance from the DAT cassette drive inlet so that the magazine is transported between the mechanism and the inlet. The mechanism includes a motor-driven scissors mechanism whose output arm extends into a selected one of the plurality of chambers in the magazine, thereby pushing the cassette out of the chamber and into the DAT drive. A latching means, carried on, and extending beyond, the end of the scissors output arm, is inserted between the cassette and the floor of the chamber containing it, through a slot which runs front-to-back along the floor, and hooks into a recess which is characteristic of DAT cassettes. When a cassette is ejected from the DAT drive into the selected chamber of the magazine, the scissors output arm is retracted, and the hook rides up a ramp at the end of the slot in the floor of the magazine chamber, into engagement with the cassette recess, thereby hooking into the cassette and drawing it out as the scissors arm retracts.
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RELATED APPLICATIONS
[0001] This patent application claims the benefit of U.S. Provisional Patent Application Serial No. 60/302,630 filed Jul. 2, 2001 and entitled Truck Operated Transfer System.
BACKGROUND
[0002] 1. The Field of the Invention
[0003] This invention relates generally to the field of transfer equipment. More particularly this invention relates to an apparatus to move a body from a supporting structure onto a truck. This invention also relates to mechanisms for coupling trailers to vehicles. More particularly, the invention relates to draw bars for securing trailers to trucks.
[0004] 2. The Background Art
[0005] In many instances cargo or equipment needs to be loaded onto trucks. These loads are generally very large and may require specialized equipment to aid in loading and unloading. Loads may be containers, dump-truck bodies, mechanical equipment such as cranes or spreaders, or the like. A special problem exists where the transfer of a load onto a truck needs to take place away from industrial equipment such as cranes, fork-lifts, or other supporting equipment. In such cases the capability to transfer the load must be relocatable to the location of the vehicle.
[0006] In some situations an operator of a truck may maximize the amount of cargo hauled during a trip by carrying a load mounted on the truck as well as drawing a trailer carrying additional cargo. For example, a dump truck may tow a trailer having an additional dump truck body mounted thereto. In this manner the truck may carry more cargo to or from a work site in a single trip. In some locations local laws may limit the weight of the load a truck is allowed to carry, based on the number of axles and the spacing between axles. Thus a trailer allows a truck to carry more load than the law would normally permit the truck to carry directly.
[0007] Dump trucks have long made use of such functionality by towing “pup trailers” having their own dumping body. In some cases a pup trailer may have its own hydraulics to effect dumping of a load. A dump truck may also tow a transfer trailer that does not have dumping hydraulics. The body of the transfer trailer must therefore be transferred into the dumping body on the truck in order for the load to be dumped. An advantage of a transfer trailer is that a truck can transport a large load because of the extended wheel base of the truck and transfer trailer, and yet can still have good maneuverability at the dump-site because of the short wheelbase of the dump truck. In addition the transfer trailer is made inexpensive through the elimination of hydraulic dumping hardware or other complex systems.
[0008] Some transfer trailers have small roller wheels that are powered along a track by an air or even electrical motor mounted to a transfer body resting on the transfer trailer. In typical operation an operator will position the back of the truck adjacent the front of the transfer trailer. The operator then exit the truck and goes to a switch at the back of the transfer trailer. The operator will then activate a switch that powers the wheels to propel the transfer body into the truck body. In some cases the roller wheels may roll along rails on the transfer trailer. In some systems, the operator must continually apply force to the switch as the transfer body moves from the trailer frame into the truck body in order to load the transfer body. Accordingly, the operator is obliged to walk along with the transfer body as it is loaded into the truck.
[0009] Such a manner of operation has many inconveniences and disadvantages. First of all, the operator must exit the safety and controlling environment of the truck in order to effect the loading of the transfer trailer body. The unprotected operator is very close to a moving object weighing many tons during the process. In addition, the amount of force that can be transferred between the transfer body roller wheels and the transfer trailer is limited by the frictional forces that the roller wheel can exert on the rails.
[0010] The amount of energy available to effect the transfer is also limited by the amount of energy that can be stored on the transfer body as pressurized gas, a battery, or the like. Thus, the wheels may not be able to overcome the weight of the transfer body if the transfer trailer is inclined. Thus, it would be an advancement in the art to provide a transfer system powered by the truck, in order to provide more power and energy to effect transfer of the transfer body. It would be a further advancement in the art to provide a transfer system that could be operated from within the cab of a truck.
[0011] Once the transfer body is loaded onto the truck the operator is then required to again exit the truck and unlatch the tailgate of the transfer body so the load can be dumped. The operator then must enter the cab of the truck to operate the controls for the hydraulics to dump the contents of the transfer body. Disadvantages to this manner of operation include the fact that the driver must exit the truck to unlatch the tailgate. It may also pose a safety risk, inasmuch as the load may be exerting a force on the tailgate such that when the latch is released the load may spill out creating potential for potential harm of the operator.
[0012] In some applications it may be advantageous for the truck to be in motion when the latch is released, such as when the truck is being used to spread material. Thus, a further disadvantage of such a conventional system is that the transfer body cannot be used to spread material, since the tailgate cannot be unlatched while the truck is in motion. Thus it would be an advancement in the art to provide a transfer body having a tailgate latch operable from within the cab of a truck.
[0013] A transfer trailer may be secured to a truck by a draw bar. The draw bar typically has a fixed length such that the truck must be positioned at a precise distance from the trailer in order for the draw bar to connect to a hitch on the truck. To accomplish this an operator will typically turn off the engine and leave the truck with the brake disengaged, the transmission in reverse gear, and the clutch engaged. The operator will then walk to the back of the truck and push a button activating the starter motor of the truck, thereby causing the truck to move toward the drawbar. The operator is thereby enabled to position the truck with sufficient precision to connect the draw bar to the truck.
[0014] This manner of operation has the principle disadvantage that an operator must stand behind a truck weighing many tons and set it in motion without access to a brake. A further disadvantage is that it is not conveniently performed with trucks having automatic transmissions. Thus it would be an advancement in the art to provide a drawbar that is extensible, enabling an operator to position the truck with less precision relative to the trailer. The operator would then be able to safely engage the brake of the truck before walking behind the truck to connect the draw bar to the truck. The draw bar could then be extended to reach the hitch on the truck, compensating for imprecision in the position of the truck relative to the transfer trailer. Such an extensible draw bar would have applications for a variety of trailers, besides transfer trailers, that makes use of draw bars in order to connect to a towing vehicle.
BRIEF SUMMARY OF THE INVENTION
[0015] An invention is disclosed in sufficient detail to enable one of ordinary skill in the art to make and use the invention. In some embodiments a transfer module may rest on a support. In some embodiments a driver mounted to a truck may engage a track secured to the transfer module. The driver may engage the track in order to draw the transfer module onto the truck. In some embodiments the truck may have a dumping body having a substantially continuous floor. The track may be mounted to a pull bar secured at the rearward end of the transfer module. The pull bar may be pivotably secured to the rearward end of the transfer module. The transfer module may be pulled inside the dumping body whereas the pull bar may be located underneath the dumping body when the transfer module is loaded onto the truck.
[0016] The track may be a chain extending along the pull bar and the driver may have a sprocket configured to engage the chain. Registration members such as horns secured to the forward end of the support may serve to align the transfer module and truck. The horns may insert into tubes or cavities formed in the truck.
[0017] In some embodiments the transfer module may be embodied as a transfer dumping body having a tailgate. A latching system may enable an operator to latch and unlatch the tailgate of the transfer dumping body. In some embodiments an actuator may drive the movement of the latching system. In some embodiments the actuator may serve to both latch and unlatch the tailgate of the transfer dumping body as well as the tailgate of the dumping body mounted on the truck. In certain embodiments a locking systems may maintain the tailgates of the transfer dumping body and truck-mounted dumping body latched. In certain embodiments the locking systems may maintain themselves locked without the continuous application of force. In certain embodiments a locking system may be embodied as an over-center lock taking advantage of the toggle position of a linkage forming part of the locking system.
[0018] A trailer may have a draw bar secured thereto. A truck hitch may secure near a free end of the draw bar. In certain embodiments an extension may be adjustable with respect to the remaining portion of the draw bar. In certain embodiments a lock may be activated to fix the position of the extension relative to the remainder of the draw bar. In certain embodiments the lock may be embodied as pins or posts secured to a pneumatic piston. The pneumatic piston may fix the position of the extension relative to the remaining portion by forcing a pin, post, or the like, into an aperture formed in the free end. In certain embodiments an extender may provide the force to drive the extension outwardly from the remaining portion in order to extend the length of the draw bar. In certain embodiments the extender may be a pneumatic piston acting on the extension.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The foregoing and other objects and features of the present invention will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. Understanding that these drawings depict only typical embodiments of the invention and are, therefore, not to be considered limiting of its scope, the invention will be described with additional specificity and detail through use of the accompanying drawings in which:
[0020] [0020]FIG. 1 is a perspective view of a transfer system in accordance with the invention;
[0021] [0021]FIG. 2 is a perspective cutaway view showing components of the transfer system in accordance with the invention;
[0022] [0022]FIG. 3 is lower quarter perspective view of a transfer module and track with various alternative track embodiments in accordance with the invention;
[0023] [0023]FIG. 4 is a side elevation view of a transfer system in accordance with the invention;
[0024] [0024]FIG. 5 is a side elevation view of a transfer system with the trailer and draw bar oriented in preparation for engagement of the truck and support in accordance with the invention;
[0025] [0025]FIG. 6 is a side elevation view of a transfer system with the truck and support engaged with one another in accordance with the invention;
[0026] [0026]FIG. 7 is a partial cutaway side elevation view detailing the disposition of various components of the transfer system when engaged in accordance with the invention;
[0027] [0027]FIG. 8 is a side elevation view of a transfer system with the transfer module loaded onto the truck in accordance with the invention;
[0028] [0028]FIG. 9 is a partial cutaway side view detailing the disposition of the various components of the transfer system when the transfer module is loaded onto the truck;
[0029] [0029]FIG. 10 is a side elevation view of a transfer system having an alternative embodiment of a support in accordance with the invention;
[0030] [0030]FIG. 11 is a bottom, rear quarter perspective view of an alternative embodiment of a track and pull bar in accordance with the invention;
[0031] [0031]FIG. 12 is a is a perspective cutaway view showing an alternative embodiment of a truck body in accordance with the invention;
[0032] [0032]FIG. 13 is a cutaway perspective view of a transfer system which does not have a dumping body secured to the truck;
[0033] [0033]FIG. 14 is a cutaway perspective view showing alternative embodiments for a driver in accordance with the invention;
[0034] [0034]FIG. 15 is a cutaway perspective view of a transfer system having a track mounted on the truck in accordance with the invention;
[0035] [0035]FIG. 16 is a partial side elevation view of the apparatus of FIG. 15 showing the disposition of the various components of the apparatus when the support and transfer module are initially engaged with the truck in accordance with the invention;
[0036] [0036]FIG. 17 is a partial side elevation view of the apparatus of FIG. 15 showing the disposition of the various components of the apparatus as the transfer module is being moved onto the truck;
[0037] [0037]FIG. 18 is an exploded view of the components of a latching system and a locking system for a transfer module tailgate in accordance with the invention;
[0038] [0038]FIG. 19 is an exploded view of the components of a latching system and a locking system for a truck-mounted dumping body tailgate in accordance with the invention;
[0039] [0039]FIGS. 20A and 20B are side elevation views of an over-center lock in accordance with the invention;
[0040] [0040]FIG. 21 is a side elevation of latching and locking systems for use with transfer module and truck-mounted dumping body tailgates, with the transfer module tailgate locked in a closed position in accordance with the invention;
[0041] [0041]FIG. 22 is a side elevation of latching and locking systems for use with a transfer module and truck-mounted dumping body tailgates, with the latching systems in unlocked positions in accordance with the invention;
[0042] [0042]FIG. 23A is a schematic representation of an electrical system for use in accordance with the invention
[0043] [0043]FIG. 23B is a schematic representation of a hydraulic system suitable for use in accordance with the invention;
[0044] [0044]FIG. 23C is a schematic representation of a pneumatic system for use in accordance with the invention;
[0045] [0045]FIG. 24 is a partial perspective view of an extensible draw bar in accordance with the invention;
[0046] FIGS. 25 A-C are cross sectional views illustrating the manner of operation of a lock suitable for use with an extensible draw bar in accordance with the invention;
[0047] [0047]FIG. 26 is a partial perspective view of an alternative embodiment of an extensible draw bar in accordance with the invention;
[0048] [0048]FIG. 27 is a partial perspective view of an alternative embodiment of an extensible draw bar in accordance with the invention; and
[0049] FIGS. 28 A- 28 C are side elevation views showing a manner of operation of an extensible draw bar in accordance with the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0050] It will be readily understood that the components of the present invention, as generally described and illustrated in the Figures herein, may be arranged and designed in a wide variety of different configurations. Thus, the following more detailed description of the embodiments of the system and method of the present invention, as represented in FIGS. 1 through 28C, is not intended to limit the scope of the invention. The scope of the invention is as broad as claimed herein. The illustrations are merely representative of certain, presently preferred embodiments of the invention. Those presently preferred embodiments of the invention will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout.
[0051] Those of ordinary skill in the art will, of course, appreciate that various modifications to the details of the Figures may easily be made without departing from the essential characteristics of the invention. Thus, the following description of the Figures is intended only by way of example, and simply illustrates certain presently preferred embodiments consistent with the invention as claimed.
[0052] Referring to FIG. 1, an apparatus 10 may comprise a truck 12 and a transfer module 14 . The transfer module 14 may rest on a support 16 . The support 16 may be embodied as a trailer 18 towable by a truck 12 . In certain embodiments the trailer 18 may have a draw bar 20 secured to the trailer 18 . The draw bar may serve to couple the trailer 18 to the truck 12 . The truck 12 may have a body 22 secured to a frame 24 .
[0053] A longitudinal direction 26 a may be defined as being parallel to the direction of travel of a truck 12 . A lateral direction 26 b may be defined as being substantially parallel to a supporting surface under the truck 12 and perpendicular to the longitudinal direction 26 a . A transverse direction 26 c may be defined as being substantially orthogonal to both the longitudinal direction 26 a and the lateral direction 26 b. The directions 26 a - 26 c may also be considered to be axes 26 a - 26 c , accordingly rotation may be defined in terms of rotation about an axis parallel to an axis 26 a - 26 c.
[0054] The truck 12 may define a forward end 28 and a rearward end 30 . In certain embodiments the truck body may be embodied as a dumping body 32 , or dump-truck body 32 , having a tailgate 34 . The tailgate 34 may be secured to the body 32 by pivots 36 . An arm 38 may be secured to the tailgate 34 and to an actuator 40 . The actuator 40 may be used to open the tailgate 34 to facilitate dumping.
[0055] In certain embodiments the transfer module 14 may be embodied as a dumping body 42 . The dumping body 42 may have a forward end 44 and a rearward end 46 . The trailer 18 may have stops 48 formed to engage the rearward end 46 of the trailer 18 to prevent the body 42 from sliding off the trailer 18 . The body 42 may also have a tailgate 50 secured to the body 42 by pivots 52 . In certain embodiments the draw bar 20 may have a pintle ring 54 secured thereto. The pintle ring 54 may engage a pintle hitch 56 secured to the truck 12 .
[0056] Referring to FIGS. 2 and 3, in certain embodiments the transfer module 14 may have a track 60 secured thereto. The track 60 may engage a driver 62 secured to the truck 12 . In certain embodiments, the track 60 may be secured to a pull bar 64 secured to the rearward end 46 of the transfer module 14 and extending toward the forward end 44 . In certain embodiments the pull bar 64 may be secured to the transfer module 14 by means of a pivot 66 . A pivot 66 may be embodied as a bolt 68 or pin 68 , or other structure 68 , extending through apertures 70 in the transfer module 14 and through the pull bar 64 . Alternatively, a pivot 66 may be embodied as studs 68 , or a pin 68 , either fixedly or pivotably secured to the pull bar 64 and extending through an aperture 70 or apertures 70 in the transfer module 14 . A rest 72 , or restraint 72 , may be secured to the support 14 to support the pull bar 64 , capturing the pull bar 64 and preventing the pull bar 64 from falling further toward the ground. The pull bar 64 may rotate, or pivot, about a number of axes, for example, the pull bar 64 may pivot about an axis substantially parallel to a lateral axis 26 b.
[0057] The support 16 may have registration members 74 secured thereto, which may engage registration members 76 secured to the truck 12 . The registration members 74 , 76 may serve to ensure adequate alignment of the truck 12 and transfer module 14 when the transfer module 14 is being transferred on to and off of the support 16 . The registration members 74 , 76 may align the truck 12 and transfer module 14 in the longitudinal direction 26 a and the lateral direction 26 b. In certain embodiments the registration members 70 may be embodied as a horn 78 , or horns 78 , extending from the forward end 44 of the support 16 along a longitudinal direction 26 a. The horn 78 , or horns 78 , may engage receivers 80 shaped to permit insertion of a horn 78 while still substantially forcing alignment of the truck 12 and transfer module 14 . In certain embodiments, a horn 78 may have a tapered end 82 to serve as a pilot to accommodate misalignment during insertion into a receiver 80 .
[0058] In certain embodiments a lock 84 may secure to the truck 12 and lock the transfer module 14 to substantially fix its position relative to the truck 12 . The lock 84 may comprise a pin 86 actuated by a hydraulic piston 88 , pneumatic piston 88 , or the like. The pin 86 may insert into an aperture 90 formed in the transfer module 14 . In one embodiment, the aperture 90 may be formed in the pull bar 64 .
[0059] The driver 62 may be embodied as a motor 98 , such as a hydraulic motor 98 , electric motor 98 , pneumatic motor 98 , or the like, having a drive wheel 100 . In certain embodiments the track 62 may be embodied as either a rigid or flexible member 62 , such as a rack or a chain 102 . The chain 102 may be secured along the length of the pull bar 64 , or may be secured only near the free end 104 and near the secured end 106 of the pull bar 64 . Accordingly the drive wheel 100 may be embodied as a sprocket 108 for engaging the chain 102 . The rest 72 may have a notch 110 to facilitate engagement of the sprocket 108 with the chain 102 .
[0060] In certain embodiments, the transfer module 14 may have rollers 120 secured thereto to facilitate transfer of the transfer module 14 . The support 14 may have rails 122 to guide the transfer body 14 during transfer. Accordingly, the rollers 120 may have flanges 124 to maintain the rollers on the rails 122 . The truck 12 may likewise have rails 126 , along which the rollers 120 may roll. Alternatively, the transfer module 14 may simply be dragged onto the truck 12 without the benefit of rails 122 , 126 , rollers 120 , or both.
[0061] The track 60 may have various embodiments. For example, the track 60 may be a belt 132 secured near the free end 104 and near the secured end 106 of the pull bar 64 . The belt 132 may be secured at a distance 134 from the pull bar 64 in order to permit the insertion of a roller (e.g. idler) or other mechanism to increase friction between the drive wheel 100 and the belt 132 .
[0062] The track 60 may also be embodied as a rack 136 formed along the pull bar 64 . Alternatively, the track may be a surface 138 , or surfaces 138 , formed on the pull bar 64 for engaging the drive wheel 100 . The pull bar 64 may have a tapered end 140 to facilitate initial engagement with the drive wheel 100 and to accommodate misalignment between the pull bar 64 and the drive wheel 100 . The surface 138 , or surfaces 138 , may be toothed, perforated, stepped, textured, roughened, coated, treated, or the like to enhance friction between a surface 138 and the drive wheel 100 . In certain embodiments the track 60 may be mounted to the truck 12 . Accordingly the pull bar 64 may have a hook 142 a , hooks 142 a and 142 b, or a ring 142 , aperture 142 , or other structure 142 for engaging a track 60 .
[0063] Referring to FIGS. 4 and 5, a draw bar 20 may be secured to a trailer 18 by a pivot 143 allowing the draw bar 20 to be positioned as shown in FIG. 4 when towing a trailer 18 , and positioned as shown in FIG. 5 when transferring a transfer module 14 onto the truck 12 . During the process of transferring a transfer module 14 , the truck 12 and trailer 18 are typically positioned relative to one another as shown in FIG. 4. An operator may detach the pintle ring 54 from the hitch 56 and pivot the draw bar 20 out of the way into the position of FIG. 5. The operator will then back the truck toward the support 14 as shown in FIG. 5.
[0064] Referring to FIG. 6, the operator may back the truck 12 toward the support 14 such that the horns 78 insert into the receivers 80 . The track 60 is then positioned proximate the driver 62 . For embodiments having a driver 62 embodied as a hydraulic motor 98 , the motor hydraulics may be switched to allow the drive wheel 100 to spin freely as the free end 104 of the draw bar 64 is forced over the drive wheel 100 during insertion.
[0065] A trailer lock 144 may function in conjunction with the stops 48 to secure the transfer module 14 to the trailer 18 . In certain embodiments the trailer lock 144 may automatically lock the transfer module to the trailer 18 upon transfer of the transfer module 14 onto the trailer 18 . The lock 144 may also be configured to automatically disengage the transfer module 14 when a truck 12 backs up against the trailer 18 . Alternatively the lock 144 may be manually disengaged when the transfer module 14 is being transferred off the support 16 .
[0066] Referring to FIG. 7, with the truck 12 positioned relative to the transfer module 14 as shown in FIG. 6, the pull bar 64 may be positioned over the driver 62 . The track 60 may also engage the drive wheel 100 . For embodiments of the apparatus 10 having a drive wheel 100 embodied as a sprocket 108 , the pivoting of the draw bar 64 relative to the transfer module 14 may allow the free end 104 of the pull bar 64 to be forced up over the teeth of the sprocket 108 and then fall down toward the sprocket 108 with the chain 102 engaged with the teeth of the sprocket 108 . In embodiments of the apparatus 10 having a truck body 22 embodied as a dumping body 32 , the driver 62 is typically positioned below the floor 146 of the body 32 . This may be the case for other embodiments of a truck body 22 having a continuous floor 146 that cannot conveniently have transfer hardware such as a driver 62 secured thereto.
[0067] Referring to FIGS. 8 and 9, the driver 62 may be activated to exert a force on the track 60 to draw the transfer module 14 onto the truck 12 as shown in FIG. 8. The lock 84 may be activated during the transfer of a transfer module 14 into a truck 12 . The lock 84 may be continuously activated during the transfer process without effectively locking the position of the transfer module 14 into the truck 12 until the transfer module 14 is substantially completely transferred.
[0068] In embodiments of the apparatus 10 having a locking pin 86 actuated by a piston 88 , the piston 88 may push the pin 86 against a structure of the transfer module 14 , allowing the transfer module 14 to slide by until a locking aperture 90 reaches a position near the piston 88 . The piston 88 may then force the pin 86 into the aperture 90 effectively locking the transfer module 14 into the truck 12 .
[0069] In embodiments of the apparatus 10 wherein the locking aperture 90 is formed in the draw bar 64 , the locking pin 86 may slide along the draw bar 64 as the transfer module 14 is being transferred into the truck 12 until the locking aperture 90 is positioned such that the pin 86 inserts into the locking aperture 90 , as shown in FIG. 9. As shown in FIG. 9, for truck bodies 12 having continuous floors 146 the pull bar 64 is typically drawn into the envelope of the truck underneath the floor 146 while the transfer module 14 is drawn into the envelope of the truck above the floor 146 .
[0070] Referring to FIG. 10, a support 16 may be embodied as a pedestal 148 . A pedestal 148 may allow transfer modules 14 to be stored at a height 150 such that they may be loaded into a truck 12 in the same manner as a transfer module 14 stored on a trailer 18 . In this manner a municipality, or other organization or individual, may purchase a single truck 12 and have several types of transfer modules 14 stored on pedestals 148 . A transfer module 14 may have any one of several functionalities and may accordingly be embodied as a spreader 152 , dumpster 152 , container 152 , garbage-truck body 152 , crane 152 , or the like. In this manner an organization may derive more functionality from a single truck 12 .
[0071] Referring to FIGS. 11 - 13 , the pull bar 64 may be disposed in a variety of configurations. For example, the pull bar 64 may be fixedly, rather than pivotably, secured to the transfer module 14 . The pull bar 64 shown in FIG. 11 may also be formed without a chain 102 , but may rather have a surface 138 , or surfaces 138 , for engaging a drive wheel 100 . A floor 146 of a truck body 32 may have a channel 156 formed therein as in FIG. 11. The channel 156 may accommodate a pull bar 64 that is fixedly secured to the transfer module 14 . Alternatively a truck 12 may not have a floor 146 , but rather, merely a frame 24 having rails 126 , as shown in FIG. 12.
[0072] Referring to FIG. 13, a driver 62 may be disposed in a variety of configurations. For example, a driver 62 may have a drive wheel 100 embodied as a gear 160 having involute gear teeth 162 suitable for engaging a track 60 embodied as a rack 136 . The normal operation of a gear 160 having involute gear teeth 162 results in a force exerted on the mating gear directed from the axis of rotation of the gear 160 toward the point of contact with the mating gear teeth.
[0073] Accordingly, a retainer 164 may be needed to maintain the rack 136 in contact with the gear 162 . A retainer 164 may be embodied as a roller 166 spaced apart from the drive wheel 100 , such that the draw bar 64 extends between the drive wheel 100 and roller 166 with the roller 166 urging the draw bar 64 into the drive wheel 100 during transfer of a transfer module 14 .
[0074] A roller 166 may have an actuator 168 , such as a piston 168 , solenoid 168 , or the like. The actuator 168 may be activated to position the roller 166 opposite the drive wheel 100 during transfer and moved out of the way of the free end 104 of the pull bar 64 during insertion.
[0075] A track 60 may be embodied as a belt 132 . Accordingly, a drive wheel 100 may be embodied as a drive roller 170 . A roller 166 may be used to press the belt 132 against the roller 170 . The roller may insert between the pull bar 64 and the belt 132 . An actuator 168 may be used to move the roller 166 out of the way of the pull bar 64 during insertion and between the pull bar 64 and the belt 132 during transfer. A drive roller 170 may have flanges 172 to maintain the belt 132 substantially centered on the drive roller 170 .
[0076] In certain embodiments of an apparatus 10 , the track 60 may be embodied as surfaces 138 formed on the pull bar 64 . Accordingly, the drive wheel 100 may be embodied as a drive roller 170 . A retainer 164 may be used to press the pull bar 64 onto the drive wheel 100 . The retainer 164 may move the roller 166 along a substantially transverse direction 26 c . Thus the force exerted on the pull bar 64 can be controlled using the actuator 168 .
[0077] In certain uses the transfer of a transfer module 14 into or out of a truck may take place on uneven terrain. Accordingly, the transfer module 14 may not be adequately aligned with the truck 12 . The support 16 may likewise be at an angle relative to the truck 12 . Such variability in orientation may cause variations in the angle that the pull bar 64 makes with the truck 12 .
[0078] A roller 166 positioned a fixed distance away from the drive wheel 100 may be able to accommodate only small variations in the angle of the pull bar 64 relative to the truck 12 . An actuator 168 that has a range of motion parallel to a transverse direction 26 c enables the application of a force to urge the draw bar 64 onto the drive wheel 100 . In the case where the draw bar is at an angle with respect to the truck, the actuator 168 may be forced to move the roller 166 in order to accommodate the angle. However, because the motion of the draw bar 64 is parallel to the direction of motion of the actuator 168 , no bending or breakage of hardware results.
[0079] For example, an actuator 168 may be a hydraulic piston 168 . Application of pressurized hydraulic fluid to the piston will result in a constant force exerted on the pull bar 64 . Should the pull bar 64 be angled wrong it will exert a force on the roller 166 . If the force exerted by the pull bar 64 is greater than the force exerted by the piston 168 , the piston 168 will merely be extended from its cylinder until the force exerted by the pull bar 64 on the roller is equal to the force exerted by the hydraulic piston 168 .
[0080] An actuator 168 may also be a biasing spring 168 that urges the roller onto the drive wheel 100 . The free end 104 of the pull bar 64 may have a tapered end 140 such that the pull bar 64 may be piloted between the roller 166 and the drive wheel 100 when the truck 12 is backed up to the support 16 .
[0081] Alternatively, the weight of the pull bar 64 may be sufficient to maintain the urge the pull bar 64 against the drive wheel 100 such that enough friction is developed between the track 60 and drive wheel 100 to enable the drive wheel 100 to transfer force to the transfer module 14 effective to move the transfer module 14 to and from the truck 12 . In some embodiments the weight of the pull bar 64 may be enough to maintain a rack 136 in mating engagement with a gear 160 even while the gear 160 is driving the rack 136 .
[0082] The driver 62 and lock 84 may be disposed in a variety of configurations. For example, the axis of rotation of the drive wheel 100 of the driver 62 may be substantially parallel to a transverse axis 26 c. An actuator 168 may, accordingly, move substantially in a lateral direction 26 b. The lock 84 may rely on a piston 88 to move the locking pin 86 along a transverse direction 26 c, accordingly the locking aperture 90 may extend through the pull bar 64 in a transverse direction 26 c.
[0083] Referring to FIGS. 15 - 17 , a track 60 may be positioned on the truck 12 rather than on the transfer module 14 . In certain embodiments of an apparatus 10 , the track 60 may be embodied as a conveyor 178 extending from proximate the rearward end 46 toward the forward end 44 of the truck 12 . The conveyor 178 may be driven by the hydraulic motor 98 . The conveyor 178 may be a chain 180 , belt 182 , or the like. A conveyor 178 may have a dog link 184 , or dog 184 , having one or more protrusions or side pieces 186 on either one or both sides of the chain 180 , a cross bar 188 may extend therebetween.
[0084] The cross bar 188 is typically secured to the side pieces 186 such that it is positioned a distance 190 away from the chain. Alternatively the side pieces 186 may be replaced by a single hook 186 , or post 186 , protruding from the dog link 184 for engaging a hook 142 , aperture 142 , ring 142 , or the like, formed on the pull bar 64 .
[0085] Conveyors 178 embodied as belts 182 may have a dog 184 with side pieces 186 embodied as two links 194 having one end pivotably secured to the cross bar 188 and the other end secured to one of two bands attached to the belt 182 in order to allow the belt to wrap around a roller, such as a drive roller 170 .
[0086] A dog 184 may be positioned as shown in FIG. 16 at the time the truck 12 backs up to the transfer module 14 . The driver 60 may be activated to move the dog 184 to the position shown in FIG. 17. As the dog 184 moves from the position of FIG. 16 to the position of FIG. 17 the cross bar 188 catches the hook 142 a, or other protrusion, structure, or aperture. The driver 60 may then drive the dog 184 toward the forward end 44 of the truck 12 in order to load the transfer module 14 onto the truck 12 . The driver may likewise be reversed to cause the cross bar 188 to catch the hook 142 b, or other protrusion, structure, or aperture, and drive the transfer module 14 toward the rearward end 46 of the truck 12 in order to unload the transfer module 14 .
[0087] Referring to FIG. 18, a transfer module 14 having a tailgate 50 may have a latching system 200 secured to either side of the transfer module 14 . The latching system 200 shown in FIG. 18 illustrates one side of the latching system 200 , the other side of the latching system 200 may be substantially the mirror image of the side illustrated in FIG. 18. A latching system 200 may comprise a latch 202 for maintaining a tailgate 50 closed.
[0088] A locking system 204 may be used to both actuate the latch 202 and to maintain the latch 202 in a position suitable for retaining the tailgate 50 . A latch 202 may have an arm 206 for retaining a structure on the tailgate 50 in order to hold the tailgate 50 closed. In certain embodiments the arm may retain a rod 208 , post 208 , or other structure 208 , extending from the tailgate 50 .
[0089] A catch 210 may secure to the transfer module 14 . The catch 210 may serve to register the rod 208 with respect to the transfer module 14 . In certain embodiments the catch 210 may be or include a notch 212 formed to receive the rod 208 , post 208 , or other structure 208 .
[0090] The latch 204 may be either fixedly or pivotably secured to a pivot 216 or shaft 216 . The shaft 216 may be pivotably or fixedly secured to the transfer module 14 . For embodiments having a latch 204 fixedly secured to the shaft 216 , the shaft 216 is typically pivotably secured to the transfer module 14 . For embodiments having a latch 204 pivotably secured to the shaft 216 the shaft 216 may be either pivotably or fixedly secured to the transfer module 214 .
[0091] A crank 220 may be either fixedly or pivotably secured to the pivot 216 . For embodiments having a crank 220 and latch 204 pivotably secured to the pivot 216 , the crank 220 may also secure to the latch 204 such that relative rotation therebetween is substantially prevented. A pin 222 may pivotably secure the free end 224 of the crank 220 to the end 226 of a hook 230 .
[0092] A roller 238 may be rotatably secured to the hook 230 by a pin 234 . The end 240 of the hook 230 may be secured with a pin 242 to the free end 244 of a toggle link 246 . The toggle link 246 may be fixedly secured to a pivot 248 , or shaft 248 , pivotably secured to the transfer module 14 . Alternatively, the toggle link 246 may be pivotably secured to the shaft 248 and the shaft 248 may then be either pivotably or fixedly secured to the transfer module 14 .
[0093] A spring 250 may serve to predictably position the roller 238 for engagement in order to change the state of the locking system 204 . The spring 250 typically urges the hook 230 into a position to engage a driving surface, or the like, which may serve to force the hook locking system 204 into a variety of positions. The spring 250 may bias the hook 230 in a variety of directions in order to accomplish its purpose.
[0094] For example, a spring 250 , such as a torsion spring 250 or the like, may have one end 252 a engaging the hook 230 and the other end 252 b engaging the transfer module 14 to urge the end 240 of the hook 230 downward substantially in the transverse direction 26 c . Alternatively, the spring 250 may have one end 252 a engaging the toggle link 246 and the other end 252 b engaging the transfer module 14 biasing the toggle link 246 to rotate about the pivot 248 , effectively urging the end 240 of the hook 230 downward substantially in the transverse direction 26 c . The spring 250 may also have one end 252 a engaging the hook 230 and the other end 252 b engaging the toggle link 246 with the spring loaded to cause the hook 230 to rotate relative to the toggle link 246 , effectively urging the hook 230 downward substantially in the transverse direction 26 c.
[0095] Referring to FIG. 19, A truck 12 having a body 22 with a tailgate 34 may have a latching system 258 having latches 260 located on either side of the truck 12 and locking systems 262 on either side 263 of the truck 12 . A locking system may provide for locking of the position of a latch 260 relative to the truck 12 . The locking system 262 may also provide for the actuation of the latch 260 . A latch 260 may have an arm 264 for engaging a rod 266 , post 266 , or other structure 266 extending from the sides of the tailgate 34 .
[0096] Catches 268 maybe formed on the truck 12 for receiving the rods 266 . The rods 266 , or posts 266 , may be held between the arms 256 and the catches 268 when the tailgate 34 is being held closed. In certain embodiments a catch 368 may have a notch 270 for retaining a rod 266 , or post 266 . The latch 260 may be either fixedly or pivotably attached to a pivot 272 . The pivot 272 may be either fixedly or pivotably secured to the truck 12 . For embodiments of an apparatus 10 having a latch 260 fixedly secured to the pivot 272 , the pivot 272 is typically pivotably secured to the truck 12 .
[0097] A latch 260 may have a driving surface 274 on the latch 260 to engage the roller 238 secured to the hook 230 . A stop 276 may also be either formed with or secured to the latch 260 near the driving surface. The stop 276 may then catch the roller 238 as the transfer module 14 is inserted into the truck 12 and also serve to drive the locking system 204 into a locked position.
[0098] A crank 278 may be either fixedly or pivotably secured with respect to the pivot 272 . For embodiments of the apparatus 10 having a latch 260 that is pivotably secured to the pivot 272 , the crank 278 may be secured to the latch 260 such that relative rotation of the crank 278 with respect to the latch 260 is substantially prevented. For embodiments wherein the latch is fixedly attached to a pivot 272 pivotably secured to the truck 12 , the crank 278 is typically fixedly secured to the pivot 272 .
[0099] A crank 278 may have a free end 280 pivotably secured, by a pin 282 , or some other fastener 282 , to the end 284 of a hook 286 . An end 288 of the hook may be pivotably secured with a pin 290 , or other fastener 290 , to the free end 292 of a toggle link 294 . The toggle link 294 may be fixedly secured to a shaft 296 extending across the truck 12 substantially in a lateral direction 26 b. The shaft 296 may be rotatably secured to the frame 24 of the truck 12 . A crank 298 may be fixedly secured to the shaft 296 . The free end 300 of the crank 298 may engage an actuator 302 , such as a hydraulic piston 304 , or the like. Alternativley, the crank 298 may be embodied as a gear 298 which may engage a gear 306 driven by a motor 308 .
[0100] Referring to FIGS. 20A and 20B, a locking system 204 , 262 may make use of the toggle position of the various components of the system 204 , 262 in order to provide a self locking system 204 , 202 . For example a toggle link 246 , 294 , may be forced to rotate from the position shown in FIG. 20A to the position shown in FIG. 20B. The rotation of the toggle link 246 , 294 may require rotation through an angular region 324 where the distance between the end 240 , 288 and the end 226 , 284 of the hook 230 , 286 must exceed the undeformed length of the hook 230 , 286 in order for the end 226 , 284 to be moved therethrough. Thus, it requires that a force sufficient to deform a hook 230 , 286 be exerted on the toggle link 246 , 294 in order to move the hook 230 , 286 into and out of the position of 19 B. The end 226 , 284 may need to be restrained from moving in order for the rotation of the toggle line 246 , 294 to cause deformation of the hook 230 , 286 . A catch 210 , 268 may interfere with the arm 206 , 264 in order to constrain rotation of the latch 202 , 260 , effectively restraining the end 226 , 284 of a hook 230 , 286 .
[0101] The curvature 326 of the hook may facilitate locking by preventing further rotation in a direction 328 of a toggle link 246 , 294 once the hook 230 , 286 has been moved through the angular region 324 . The curvature 326 allows the end 240 , 288 to be moved through the angular region 324 without interference with the pivot 248 or shaft 296 . However, once the toggle link 246 has moved through the angular region 324 , the hook 230 , 286 will interfere with the pivot 248 , or shaft 296 , to prevent further substantial rotation in a direction 328 .
[0102] Typically a hook 230 , 286 and toggle link 246 , 294 will be loaded substantially in a direction 328 . It can readily be seen that such loading cannot result in a rotational force sufficient to move a toggle link 246 , 294 out of the position of FIG. 19B into the position of FIG. 19A. Thus, the toggle link 246 , 294 and hook 230 , 286 are effectively locked in position and require no constant exertion of force to be maintained locked. The toggle link 246 , 294 and hook 230 , 286 can therefore be used to move a structure, such as a latch 202 , 260 , through an angle 330 and lock it in place.
[0103] Referring to FIGS. 21 and 22, upon transfer of a transfer module 14 into a truck 12 the roller 238 may be positioned adjacent the driving surface 274 . The hook 230 and toggle link 246 may be in a locked position, maintaining the arm 206 of the latch pressed against the catch 210 , maintaining the tailgate 50 closed as shown in FIG. 21. The hook 286 and toggle link 294 may likewise be in a locked position.
[0104] The actuator 302 may exert a force on the crank 298 in a direction 334 , thereby causing the shaft 296 to rotate the toggle link 294 and hook 286 out of the locked position of FIG. 21. The hook 286 may then exert a force on the crank 278 , causing the driving surface 274 to push against the roller 238 . The force exerted on the roller 238 may then force the hook 230 and toggle link 246 out of the locked position of FIG. 21. The force exerted on the hook 230 may be transferred through the hook 230 to the crank 220 , opening the latch 202 and releasing the rod 208 , or post 208 , effectively allowing the tailgate 50 to open as shown in FIG. 22.
[0105] The actuator 302 may exert a force on the crank 298 in a direction 336 , thereby causing the shaft 296 to rotate the toggle link 294 and hook 286 into the locked position of FIG. 21. The hook 286 may then exert a force on the crank 278 , causing the stop 276 to push against the roller 238 . The force exerted on the roller 238 may then force the hook 230 and toggle link 246 into the locked position of FIG. 21. The force exerted on the hook 230 may be transferred through the hook 230 to the crank 220 , closing the latch 202 and engaging the rod 208 , or post 208 , effectively closing the tailgate 50 as shown in FIG. 21.
[0106] The actuator 302 may also serve to latch and unlatch the tailgate 34 of the body 32 . The actuator 302 may cause the hook 286 and toggle link 294 to move to the locked position of FIG. 21 thereby locking a rod 208 . In the absence of a transfer module 14 loaded onto the truck 12 , the latch may then move to secure the rod 266 , or post 266 , secured to the tailgate 34 between the arm 264 of the latch 260 and the catch 270 . In a like manner the actuator 302 may move the hook 286 and toggle link 294 to the open position of FIG. 2B and release the rod 266 , or post 266 , from the arm 264 of the latch 260 . In this manner the same actuator 302 may latch and unlatch both of the tailgates 34 , 50 .
[0107] Referring to FIGS. 23 A- 23 C, the pneumatic and hydraulic components of the apparatus 10 may be controlled by an electrical system 348 shown schematically in FIG. 23A. The electrical system 348 may be powered by a power source 346 , such as a battery 346 . The hydraulic components of the apparatus 10 may form part of a hydraulic system 348 shown in FIG. 23B. The hydraulic system 348 may be powered by a pressure source 350 , such as a hydraulic pump 350 associated with the truck 12 . The pneumatic components of the apparatus 10 may form part of a pneumatic system 352 shown in FIG. 23C. The pneumatic system 352 may be powered by a pressure source 354 , such as a compressor 354 on the truck 12 .
[0108] A switch 358 may be closed to apply a voltage to a tailgate valve 60 , opening the valve 60 and enabling hydraulic fluid to enter the cylinder 40 , the cylinder thereby raises the tailgate 34 of the dumping body 32 . A transfer mode switch 362 may be moved to a position 364 a in order to apply a voltage to the free wheel valve 366 . By opening the valve and thereby directing the flow of hydraulic fluid to bypass the motor 98 allowing the motor to be spun freely by the track 60 forced over the drive wheel 100 . The transfer mode switch 362 may be moved to a position 364 b to apply a voltage to a lock pin valve 368 . Opening the valve 368 and enabling pressure to be applied to the cylinder 88 causes the lock pin 86 to press against some structure of the transfer module 14 or to force itself into a locking aperture 90 .
[0109] The positioning of the transfer mode switch 362 to the position 364 b may also cause a voltage to be applied to retainer valve 370 . Opening a valve 370 and enables pressurized gas to cause the piston 168 to force the retainer 164 against a pull bar 64 to enhance friction between a drive wheel 100 and the track 60 . An override switch 372 may be used to cut off voltage from both the free wheel valve 366 and the retainer 164 . This may enable a user to disengage the locking pin 86 from the transfer module 14 when the transfer module 14 is being transferred out of the truck 12 .
[0110] The engage mode switch 374 may have positions 376 a , 376 b . The engage mode switch 374 may be placed in position 376 b to permit the application of voltage to a light in the cab of a truck 12 , thereby alerting the operator that a transfer module 14 is safely locked onto the truck 12 . The transfer mode switch 362 and engage mode switch 374 may be coupled by a linkage 378 such that whenever the switch 362 is in the position 364 a the switch 374 is in position the 364 a. Whenever the switch 362 is in the position 364 b the switch 374 is in position 364 b. Thus, the light 380 will not turn on unless the lock pin valve 368 is open.
[0111] A dump switch 382 may control the flow of hydraulic fluid to the hoist 383 . The dump switch 382 may have two positions 384 a , 384 b . The switch 382 may be located in position 384 a in order to apply a voltage to the dumping valve 386 . Opening the valve 386 pressurizes the hoist 383 to dump the load of the dumping body 32 .
[0112] The undump switch 388 may have two positions 388 a , 388 b . The switch 388 may be positioned in a position 390 a in order to apply a voltage to the undumping valve 392 . Opening the valve 392 enables the hoist 382 to de-pressurize, allowing the dumping body 32 to rest on the frame 24 of the truck 12 . The switches 382 , 388 may also have positions 384 c , 390 c resulting in an open circuit between the power source 346 and the valves 386 , 392 . The dump switch 382 and undump switch 388 may be coupled by a linkage 394 such that the switch 382 is in one of the positions 384 a - 384 c whenever the switch 388 is in one of the positions 390 a - 390 c , respectively.
[0113] A transfer switch 396 may have positions 398 a - 398 c . The switch 396 may be located in a position 398 a in order to apply a voltage to a transfer in valve 400 . Opening the valve 400 pressurizes the hydraulic motor 98 in a direction causing the transfer module to be transferred onto the truck 12 . The switch 396 may be located in the position 398 b in order to apply a voltage to a transfer out valve 402 . Opening the valve 402 pressurizes the motor 98 such that the transfer module 14 is transferred off the truck 12 .
[0114] A tailgate lock switch 404 may be closed to apply a voltage to the tailgate lock valve 406 , opening the valve 406 and causing the actuator 302 to open the tailgate latches 202 and 260 . In certain embodiments, the actuator 302 may have a bias such that when the valve 406 is open, the actuator 302 moves the latches 202 , 260 into locked positions as in FIG. 21.
[0115] A lock sensor 408 may follow the position of the lock 84 and restrict the operation of the other components of the hydraulic system 348 and pneumatic system 352 . For example the lock sensor 408 may be in a position 410 a when the lock pin 86 is engaged with the aperture 90 . Placing the sensor 408 in a position 410 a enables the light 380 to turn on indicating that the transfer module 14 is safely locked onto the truck 12 . The placement of the sensor 408 in position 410 a may also enable a voltage to be applied to the dump valve 386 in order to open it and dump a load from the truck 12 .
[0116] The sensor 408 may be placed in a position 410 b indicating that the lock pin 86 has not fully engaged the aperture 90 . Placing the sensor in position 410 b may prevent the application of voltage to the light 380 and dumping valve 386 , preventing the dumping of a transfer dumping body 42 not properly locked onto the truck 12 .
[0117] Referring to FIG. 23, a draw bar 20 may have an extension 450 slidably secured to a static portion 452 . The extension 450 may be adjustable with respect to the static portion 252 in order to vary the distance 454 between the pintle ring 54 and the static portion 452 . The adjustability of the distance 454 may provide for easier securement of a trailer 18 to a truck 12 . The adjustability may provide for the truck 12 to be positioned with the pintle hitch 56 located within a large region rather than at a specific point and still allow for the pintle ring 54 to be placed on the pintle hitch 56 . The extension 450 may have arms 456 a , 456 b , or a single arm 456 , which may slide along a guide 458 secured to the static portion 452 .
[0118] The guide 458 may be embodied as sleeves 460 a , 460 b , or a single sleeve 460 secured to arms 462 a , 462 b of the static portion 452 . The arms 456 a , 456 b , or arm 456 , may slide within the sleeves 460 a , 460 b , or sleeve 460 , in order to provide adjustability of the distance 454 . A lock 464 may fix the position of the extension 450 with respect to the static portion 452 . An extender 466 may move the extension 450 with respect to the static portion 452 .
[0119] In certain embodiments the extender 466 may be a pneumatic piston 467 , hydraulic piston 467 , electric actuator 467 , or the like. The pneumatic piston 467 may exert a force on a cross beam 468 secured to both of the arms 456 a , 456 b . In certain embodiments an operator may control the flow of air to the piston 467 in order to control extension of the extension 450 . In some embodiments an operator will open a valve or the like in order to allow pressurized gas, or the like, to contact the piston 467 . The cross beam 468 may serve to provide stiffness to the extension 450 and ensure that the arms 456 a , 456 b move simultaneously. The arms 456 a , 456 b may have apertures 470 formed therein to receive locking pins or the like to fix the position of the extension 450 with respect to the static portion 452 . In certain embodiments there may be a plurality of apertures 470 formed along an arm 456 a and along an arm 456 b . This may enable the pintle ring 454 to be fixed at a variety of lengths 454 from the static portion 452 .
[0120] In operation, an operator may disengage the lock 464 such that the extension 450 is free to move with respect to the static portion 452 . The operator may extend the extension 450 to the pintle hitch 56 and secure the pintle ring 54 thereto. The operator may then activate the lock 164 . The lock 164 may then automatically engage, fixing the position of the extension 450 with respect to the static portion 452 as the operator backs the truck 12 toward the trailer 18 .
[0121] Referring to FIGS. 25 A- 25 C, a lock 464 may have an actuator 471 for engaging and disengaging the lock 464 . In certain embodiments the actuator 471 may move the lock 464 from the state shown in FIG. 25A to the state shown in FIG. 25C. In certain embodiments the actuator 471 may be embodied as a pneumatic piston 472 and cylinder 474 . Alternatively, the actuator 471 may be embodied as a hydraulic piston 472 and cylinder 474 , electric actuator 474 , or the like. In certain embodiments the lock 464 may be secured to the guides 458 . In other embodiments the lock 464 may be secured to the arms 456 a , 456 b , or arm 456 . A pin 476 may be secured to the piston 472 and a pin 478 secured to the cylinder 474 .
[0122] The cylinder 474 may be pressurized and force the piston 472 to move outwardly from the cylinder 474 . In certain embodiments an operator may pressurize the cylinder 474 by opening a valve, or the like, to allow pressurized gas to enter the cylinder 474 . The motion of the piston 472 may drive the pin 476 into an aperture 479 formed in the sleeve 460 a and the aperture 470 formed in the arm 456 a . The pin 478 may move into an aperture 479 formed in the sleeve 460 b and the aperture 470 formed in the arm 456 b , as shown in FIG. 25B. When the apertures 470 are not aligned with the pins 476 , 478 , as shown in FIG. 25C, the pins 476 , 478 may press against the arms 456 a , 456 b until the arms 456 a , 456 b are moved into position such that the apertures 470 are aligned with the pins 456 a , 456 b , at that point, the pins 476 , 478 will be forced into the apertures 470 . This may allow for the extension 450 to be drawn out in order to facilitate coupling with a trailer 18 .
[0123] The cylinder 474 may then be pressurized and the truck 12 backed toward the trailer 18 such that the arms 456 a , 456 b are pushed along the sleeves 460 a , 460 b until the pins 476 , 478 are aligned with the apertures 470 . The pins 476 , 478 may then insert into the apertures 470 effectively fixing the position of the extension 450 relative to the static portion 452 such that the truck 12 can now tow the trailer 18 .
[0124] In certain embodiments the arms 456 a , 456 b , or arm 456 a , may be formed as rectangular tubes. The locking pins 476 , 478 may be responsible for transferring loads from the extension 450 to the static portion 452 . The pins 476 , 478 may, therefore, exert very large forces on the arms 456 a , 456 b , or arm 456 a . Accordingly, a bushing 480 may be inserted into an aperture 470 and extend across the vacant area of the tube to help distribute loads from a locking pin 476 , 478 across both sides of the tube.
[0125] The actuator 471 may be slidably mounted with a guide 482 . The guide 482 may be embodied as slots 484 receiving pins 485 . The slots 484 may be formed in flanges 486 secured to the actuator 471 . Alternatively, the guide 482 may be embodied as rails 487 extending between the sleeves 460 a , 460 b . The actuator 471 may be secured to the rails and slide substantially freely therealong.
[0126] Alternatively, the guide 482 may be embodied as a channel 487 extending between the sleeves 460 a , 460 b with the actuator 471 sliding therealong. The pins 484 may be fixed to supports 488 extending between the arms 462 a , 462 b of the static portion 452 . The pins 484 may secure the actuator 471 to the supports 488 while still permitting the pins 484 to slide along the slots 485 .
[0127] The pin 476 may have a stop 490 formed thereon. The stop 490 may be embodied as a shoulder 491 , snap ring 491 , or other suitable structure 491 . The stop 490 may serve to prevent the pin 476 from inserting completely into the aperture 479 . In normal operation the piston 472 will continue to be forced outwardly from the cylinder 474 . The stop 490 will push against the sleeve 460 a causing the cylinder 474 and the pin 478 to slide along the guide 522 toward the sleeve 460 b until the pin 478 inserts sufficiently into the aperture 479 of the sleeve 460 b.
[0128] In certain embodiments a pad 496 may absorb the impacts of the stop 490 against the sleeve 460 a . In certain embodiments a flange 494 , or shoulder 494 , may be formed on the pin 478 . The flange 494 may be forced against a pad 496 as the cylinder is pushed along the guide 482 . The pad 496 may serve to absorb impacts between the flange 494 and the sleeve 460 b.
[0129] A return mechanism 498 may return the lock 464 to the state illustrated in FIG. 25A. In certain embodiments the return mechanism 498 may be embodied as a spring 500 having one end 502 a secured to the flange 486 and the other end 402 b secured to the sleeve 460 a . Alternatively, the spring 500 may be a compression spring 500 having one end 502 a secured to the flange 486 and the other end 502 b secured to the sleeve 460 b . Likewise, a biasing spring 504 may tend to draw the piston 472 into the cylinder 474 . In actual operation, the biasing spring 504 may return the piston 472 to the position of FIG. 25A when pressure ceases to be exerted on the piston 472 .
[0130] Referring to FIG. 26, an extension 450 and lock 464 may be disposed in a wide range of configurations. In certain embodiments, the lock 464 may be secured to the extension 450 rather than to the static portion 452 . The guide 522 may be embodied as channels 506 a , 506 b secured to the arms 462 a , 462 b of the static portion 452 . In embodiments having the lock 464 secured to the extension 450 , the pins 476 , 478 may extend through the apertures 470 in the arms 462 a , 462 b whether or not the cylinder 474 is pressurized.
[0131] Referring to FIG. 27, in certain embodiments, the extension 450 may have a single arm 456 . The extension 450 may slide within a single sleeve 460 formed in the static portion 452 . In certain embodiments a support 522 may also have a sleeve 524 to further guide the motion of the arm 456 and resist twisting and bending.
[0132] The lock 464 may still be have a cylinder 474 and may be fixedly secured to the support 522 . The lock 464 may drive a pin 476 into an aperture 470 formed in the arm 456 . In certain embodiments the sleeve 524 may have apertures 528 formed therein. The pin 476 may accordingly extend through the aperture 528 and into the aperture 470 in order to lock the extension 450 relative to the static portion 452 .
[0133] An extension 450 and static portion 452 may be used as shown in FIGS. 28 A- 28 C. A truck 12 may park near the pintle ring 54 as shown in FIG. 28A. An operator may disengage the lock 464 , permitting the extension 450 to be drawn out in a direction 534 and the pintle ring 54 placed over the hitch 56 . In certain embodiments the extender 466 may be activated to provide a force tending to extend the extension 450 from the static portion 452 .
[0134] The operator may then activate the lock 464 by, for example, pressurizing the cylinder 474 . With the cylinder 474 pressurized and the extension in the position shown in FIG. 28B, the pins 476 , 478 , or pin 476 , will press against the arms 456 a , 456 b , or arm 456 . The operator may then back the truck 12 toward the trailer 18 in a direction 536 .
[0135] As the extension 450 is pushed toward the static portion 452 , the lock 464 eventually engages by, for example, forcing the pins 476 , 478 , into the apertures 470 in the arms 456 a , 456 b as the apertures 470 become aligned with the pins 478 , 476 . The lock 464 may, alternatively, force a single pin 476 into a single aperture 470 in an arm 456 as the pin 476 becomes aligned with the aperture 470 . The truck 12 and trailer 18 are then positioned suitable for towing as shown in FIG. 28C.
[0136] The present invention may be embodied in other specific forms without departing from its essential characteristics. The described embodiments are to be considered in all respects only as illustrative, and not restrictive. The scope of the invention is, therefore, indicated by the appended claims, rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.
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An extensible draw bar for facilitating coupling of a towed vehicle to a towing vehicle. An extension may be slidably secured to a static portion of a draw bar. A lock may be secured to the draw bar and be activated and deactivated to fix and release the extension, respectively. An extender may be activated to move the extension outwardly from the static portion. The extension may be slidable with respect to the lock while the lock is activated for certain positions of the extension relative to the lock. The extension may be positionable relative to the activated lock to automatically engage the lock to fix the position of the extension relative to the static portion.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a hygienic napkin for feminine use, and more particularly to an envelope for convenient insertion of absorbent material for convenient utilization.
2. Description of the Prior Art
Various types of sanitary napkins and other devices for feminine hygiene have been devised in the past. These sanitary napkins have required the employment of sizable amounts of absorbent material. As a result, because of the cost of the absorbent material and the mass and bulk thereof, packaging of such devices is expensive and the handling and shipment is also expensive. Furthermore, because of the bulk of such devices, drug stores and other retail establishments have had to assign a large area for storage and merchandising for such devices, which is less profitable than higher cost items of small size.
In many locations, women have access to various types of absorbent material such as cotton waste, rags, sawdust, and other cellulosic materials. However, these absorbent materials are generally diffcult to secure in place, and may be loose and in particles of small size. Further, there is little protection provided by the absorbent materials against fluids penetrating the entire mass and thus staining the clothes or limbs of the user.
SUMMARY OF THE INVENTION
It is therefore the primary object of the present invention to provide a hygienic envelope for receiving therein a desired amount of absorbent materials, and for conveniently mounting the envelope on the garments or body of the user while providing for safeguard against leakage.
The concept of this invention features the use of an envelope formed preferably of a non-woven hydrophobic material but capable in this invention of being made of a woven fabric. The non-woven material or woven fabric can be cotton or polyester fabric as well as any other fibers of animal, vegetable or synthetic origin, either processed for the first time or regenerated. A liner of a thin film of fluid-impervious material made of any suitble plastic material, as for example, polyethylene, polyvinyl, polypropylene, Mylar or non-woven or woven material in any color, or transparent, is provided for preventing the migration of organic or inorganic fluids through the exterior of the envelope so that the liquids that are absorbed in the hygienic envelope do not wet the user's clothing or when used in a hospital, do not stain surgical garments or the bed. Suitable adhesive strips are provided in order to fasten the hygienic envelope to the under-garments or body of the user. The adhesive employed can be of a rubber base, or any combination of natural organic adhesive may be employed and may be of a pressure-sensitive type, as desired.
It is a further object of the invention to provide a do-it-yourself type of sanitary napkin wherein an envelope is sold to the eventual user who can fill the envelope with readily available absorbent material such as rags, cotton waste, paper, sawdust, or other like material.
Still further objects of the invention reside in the provision of an hygienic napkin which can be packaged for sale in a parcel of relatively small size for many envelopes, which is efficient and comfortable to use, and inexpensive to manufacture, thereby permitting wide use and distribution.
These, together with the various ancillary objects and features of the invention which will become apparent as the description proceeds, are attained by this hygienic napkin, a preferred embodiment being shown in the accompanying drawing, by way of example only, wherein:
BRIEF DESCRIPTION OF FIGURES
FIG. 1 is an exploded perspective view of the envelope used in a preferred embodiment of the present invention;
FIG. 2 is a plan view of the hygienic napkin;
FIG. 3 is an enlarged sectional view taken along the plane of line 3--3 in FIG. 2;
FIG. 4 is an enlarged detail sectional view taken along the plane of line 4--4 in FIG. 3;
FIG. 5 is an enlarged sectional view taken along the plane of line 5--5 in FIG. 2.
DETAILED DESCRIPTION OF THE INVENTION
With continuing reference to the accompanying drawing, wherein like reference numerals designate similar parts through the various views, reference numeral 10 generally designates the hygienic napkin constructed in accordance with the concepts of the present invention. This hygienic napkin contains three main parts, an envelope 12, a water-proof sheet 14, and a filling of absorbent material 16.
The envelope 12 is made preferably of a non-woven hydrophobic material. This type of material is such that it permits flow of liquid readily therethrough and through which the moisture does not spread, thereby permitting quick passage of menstrual fluids and the like which is then absorbed by the absorbent material 16, and also provides for a more sanitary condition. Alternatively, the envelope 12 can be a woven fabric as well as being of non-woven material, even though the non-woven hydrophobic material is preferred. The woven material can be fibers of animal, vegetable, or synthetic fibers as desired. The envelope 12 includes a back 20, a front 18, and a flap 22. The back 20 is folded at 24 into overlying position above the sheet 14. The edge 26 of the back 20 is secured to the edge 28 of the sheet as by bonding, heat sealing or welding, or by stitching. Further, the peripheral edges 30 and 32 of the back 20 are secured to the peripheral edges 34 and 36 of the front 18 as by stitching, bonding, heat-sealing or welding. The peripheral edges 30 and 32, and 34 and 36 are tapered to better conform to the contours desired for the particular use, which may also be rounded off as desired. The flap likewise has converging tapered edges 38 and 40.
It is noted that the filling 16, which may be of rags, cotton wastes, paper, sawdust, or any other available cellulosic or non-cellulosic absorbent material, is inserted in the pouch formed between the front 18 and the sheet 14 in the direction of the arrow 42. The sheet 14 is preferably a thin film of polyethylene, but may be made of polyvinyl, polypropylene, Mylar, or non-woven or woven material that is waterproof and may be transparent or of any color. After the absorbent material 16, which may be of a comminuted or small particle size, has been inserted in the pouch in the space between the sheet 14 and the front 18, the flap 22 may be folded in the direction of the arrow 44 to overlie the back.
Coated on the back are adhesive strips as at 49 which are used to hold the flap 22 in a closed position, closing the pouch and retaining the absorbent material 16 in position. The peelable tabs 48 are used to protect the adhesive strips until the sanitary napkin is ready to be inserted within the undergarments of the user. The tabs 48 are removed so that at least a portion of the adhesive strips 49 may be used to fasten the napkin 10 directly to the undergarment of the user. The adhesive strips may be of any rubber base and preferably of pressure-sensitive adhesive or may be formed of any combination of adhesive found to be of non-allergic quality.
As shown in FIG. 4, in the construction of the invention at the peripheral edges, as for example, of the back 20, the peripheral edge 32 is bent over to form a hem 50. Likewise, the front 18 has its peripheral edge at 36 bent over to form a hem 54. Stitching as at 56 or other means of securing the parts together is used to provide for very effective reinforcement and a strong edge, thereby preventing leaking. In use, with the hygienic napkin mounted in position, fluids will pass through the hydrophobic front 18 and will be absorbed by the absorbent material 16. Seepage onto the garments will thereby be prevented.
A latitude of modification, substitution and change is intended in the foregoing disclosure, and in some instances, some features of the invention may be employed without a corresponding use of other features.
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An hygienic napkin comprising an envelope of liquid penetrable material which is folded and secured in such a manner as to form a pouch for receiving absorbent material therein. The envelope is provided with a flap for closing the pouch and a fluid-impervious sheet is provided for preventing passage of liquids all the way through the envelope.
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FIELD OF THE INVENTION
This invention relates to the data processing field. More specifically, this invention relates to object encapsulation within an object-oriented programming environment.
BACKGROUND OF THE INVENTION
The development of the EDVAC computer system of 1948 is often cited as the beginning of the computer era. Since that time, computer systems have found their way into just about every aspect of the American life style. One reason for this proliferation is the ability of computer systems to perform a variety of tasks in an efficient manner. The mechanisms used by computer systems to perform these tasks are called computer programs.
Like computer systems themselves, the development of computer programs has evolved over the years. The EDVAC system used what was called a "one address" computer programming language. This language allowed for only the most rudimentary computer programs. By the 1960s, improvements in computer programming languages led to computer programs that were so large and complex that it was difficult to manage and control their development and maintenance.
Hence, in the 1970s, focus was directed away from developing new programming languages towards the development of programming methodologies and environments which could better accommodate the increasing complexity and cost of large computer programs. One such methodology is the Object Oriented Programming (OOP) approach. OOP advocates claim that this approach to computer programming can improve the productivity of computer programmers by as much as twenty-five fold. Hence, while it has been some time since OOP technology was originally developed, it is currently seen as the way of the future.
Not surprisingly, objects are central to OOP technology. Objects can be thought of as autonomous agents which work together to perform the tasks required of the computer system. A single object represents an individual operation or a group of operations that are performed by a computer system upon information controlled by the object. The operations of objects are called "methods" and the information controlled by objects is called "object data" or just "data." Methods and object data are said to be "encapsulated" in the object. The way an object acts and reacts relative to other objects is said to be its "behavior." Since the proper function of the computer system depends upon objects working together, it is extremely important for each object to exhibit a consistent behavior.
When a method of one object needs access to the data controlled by a second object, it is considered to be a client of the second object. To access the data controlled by the second object, one of the methods of the client (i.e., a client method) will call or invoke the second object to gain access to the data controlled by that object. One of the methods of the called object (i.e., a server method in this case) is then used to access and/or manipulate the data controlled by the called object. Limiting access to the called object's own methods is critical because each object's ability to exhibit a consistent behavior depends on its ability to prevent the methods of other objects from directly accessing and manipulating its data. Indeed, limiting access to the called object's own methods is so critical that the whole OOP methodology breaks down if this encapsulation is not preserved.
One mechanism for enforcing object encapsulation is presented in the copending, commonly assigned patent application having the Ser. No. 08/336,581. While the mechanism described in the copending patent application is an excellent solution to the problem of object encapsulation enforcement, the mechanism depends on the existence of specialized hardware that provides object based memory protection.
Without a hardware independent object encapsulation enforcement mechanism, the inability to guarantee object encapsulation will continue to limit the benefits of OOP.
SUMMARY OF THE INVENTION
A hardware independent object encapsulation enforcement mechanism is disclosed herein. The object encapsulation enforcement mechanism of the present invention uses encryption technology to ensure that data controlled by an object is accessed solely through use of the object's method programs. When an object is instantiated, the virtual address used to refer to the object is encrypted before it is returned to the instantiating application program. When access to a previously instantiated object is requested, the object encapsulation enforcement mechanism decrypts the presented object address and passes the address to the identified method program, thereby ensuring that only object method programs have access to data controlled by the object.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of the computer system of the present invention.
FIG. 2 is a flow diagram that shows steps used to carry out object creation and object address encryption, according to the preferred embodiment of the present invention.
FIG. 3 is a flow diagram that shows steps used to carry out object address decryption and object access, according to the preferred embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Overview
For those readers who are not experts in computer system memory organization or with the creation and use of object-oriented objects, a brief overview of these topics is presented here. Those readers who are familiar with computer system memory organization and object addressing should proceed to the Detailed Design section of this patent. The Detailed Design section immediately follows this Overview section.
Computer System Memory Organization
As is well known, information (called data) is stored in the computer system's memory. Computer system memory is generally categorized into two types, "main memory" and "auxiliary storage." Computer system information is located using what are called "memory addresses." Information stored in main memory is located via addresses known as real addresses, while information stored in auxiliary storage is located in a way that is specific to the particular type of auxiliary storage device. In general, main memory is used by the computer system to store information that is of current interest to the programs executing on the computer system's processor. Auxiliary storage, on the other hand, is used to store information that is not currently needed by the computer system's programs.
Over the years, computer system designers have created numerous types of addressing schemes. While these addressing schemes are quite complicated and vary to a large degree, most modern day addressing schemes share the concept of "virtual addressing." At the most fundamental level, virtual addressing allows most programs to operate without having to understand whether needed information is stored in main memory or in auxiliary storage. In other words, virtual addressing allows programs to locate and access needed information through a single virtual address, regardless of whether the information is actually stored in main memory or in auxiliary storage.
Object Creation and Access
Fundamentally, objects are created and accessed in the same way as any other information-oriented, computer system entity (i.e., as has just been described in the discussion of computer system memory organization). However, there are a few subtleties about object creation and access that bear explanation. When a program needs to create an object, it does so by requesting main memory space from the computer system's operating system. The operating system responds by first allocating the space needed for the object and then by returning the virtual address associated with the beginning of that space. This address then becomes the object's address, and of course, the address that clients use to gain access to the object.
DETAILED DESIGN
Turning now to the drawings, FIG. 1 shows a block diagram of the computer system of the present invention. The computer system of the preferred embodiment is an enhanced IBM AS/400 computer system. However, those skilled in the art will appreciate that the mechanisms and apparatus of the present invention apply equally to any computer system, regardless of whether the computer system is a complicated multi-user computing apparatus or a single user workstation. As shown in the exploded view of FIG. 1, computer system 100 comprises main or central processing unit (CPU) 105 connected to main memory 140, terminal interface 145, mass storage interface 155, and network interface 160. These system components are interconnected through the use of system bus 150. Auxiliary storage interface is used to connect mass storage devices (such as DASD device 195) to computer system 100.
Although computer system 100 is shown to contain only a single main CPU and a single system bus, those skilled in the art will appreciate that the present invention may be practiced using a computer system that has multiple CPUs and/or multiple buses.
Computer system 100 utilizes well known virtual addressing mechanisms that allow the programs of computer system 100 to behave as if they have access to a large, single storage entity instead of access to multiple, smaller storage entities such as main memory 140 and DASD device 195. Therefore, while application programs 185, object encapsulation enforcement mechanism 192, and operating system 165 are shown to reside in main memory 140, those skilled in the art will recognize that these programs are not necessarily all completely contained in main memory 140 at the same time. (It should also be noted that the term "computer system memory" is used herein to generically refer to the entire virtual memory of computer system 100.)
Application programs 185 are further shown to contain objects 190. As described in the Background section of this patent, objects 190 work together to perform the tasks required of the computer system. It should be noted that the statement of whether an object is a client object or a server object is one of relativity. In other words, an object that is said to be a client object relative to another object because its methods call those of the server object may well itself be a server object relative to other objects (i.e., because methods of those other objects call its methods). It should also be noted that the advantages of the mechanisms of the present invention have broader applicability than just to pure object-oriented environments (i.e., those that are made up solely of objects). One example is the case where standard procedural programs are used to access data controlled by objects. Accordingly the word "client" should be taken to refer to any programming entity (procedural, object-oriented, or otherwise) that seeks to gain access to the data controlled by an object.
Object encapsulation enforcement mechanism 192 comprises encryptor 180 method call manager 175, and storage management mechanism 170. Encryptor 180 is used to encrypt and decrypt object addresses that are respectively passed to it by storage management 170 or by method call manager 175. The AS/400 computer system of preferred embodiment provides encryption capability through an application programming interface (API) called CIPHBER. The CIPHER API uses the ANSI data encryption algorithm, which is standard in the industry; however, those skilled in the art will appreciate that the spirit and scope of the present invention is not limited to any one encryption mechanism. Indeed, the mechanisms of the present invention will work with any encryption mechanism that is capable of encrypting the object addresses used by particular computer system at issue.
Method call manager 175 is used in the preferred embodiment as a supervisory mechanism for controlling client calls to objects. Though method call manager 175 is shown as a separate entity to highlight its functionality and to best explain the mechanisms of the present invention, method call manager 175 can also be thought of as part of operating system 165.
Storage management 170 is the mechanism responsible for controlling and maintaining the virtual address space of computer system 100. Though storage management 170 is shown as a separate entity to highlight its functionality and to best explain the mechanisms of the present invention, storage management 170 can also be thought of as part of operating system 165. It should also be understood that the term "storage management mechanism" is not intended to somehow narrow the scope of the present invention and that all operating systems include an entity or group of entities that is/are responsible for managing computer system memory.
Operating system 165 is a multitasking operating system known in the industry as OS/400; however, those skilled in the art will appreciate that the spirit and scope of the present invention is not limited to any one operating system.
The interfaces (called input/output processors in AS/400 terminology) that are used in the preferred embodiment each include separate, fully programmed microprocessors that are used to off-load compute-intensive processing from CPU 105. However, those skilled in the art will appreciate that the present invention applies equally to computer systems that simply use I/O adapters to perform similar functions.
Terminal interface 145 is used to directly connect one or more terminals to computer system 100. These terminals, which may be non-intelligent or fully programmable workstations, are used to allow system administrators and users to communicate with computer system 100.
Network interface 160 is used to connect other computer systems and/or workstations to computer system 100 in networked fashion. The present invention applies equally no matter how computer system 100 may be connected to other computer systems and/or workstations, regardless of whether the connection(s) is made using present-day analog and/or digital techniques or via some networking mechanism of the future. It is also important to point out that the presence of network interface 160 within computer system 100 means that computer system 100 may engage in cooperative processing with one or more other computer systems or workstations. Of course, this in turn means that the programs shown in main memory 140 need not necessarily all reside on computer system 100. For example, one or more programs of application programs 110 may reside on another system and request access to one or more server objects that reside on computer system 100. This cooperative processing could be accomplished through use of one of the well known remote object access mechanisms such as those that are compliant with CORBA's Object Requester/Broker service.
It is important to note that while the present invention has been (and will continue to be) described in the context of a fully functional computer system, that those skilled in the art will appreciate that the mechanisms of the present invention are capable of being distributed as a program product in a variety of forms, and that the present invention applies equally regardless of the particular type of signal bearing media used to actually carry out the distribution. Examples of signal bearing media include: recordable type media such as floppy disks and CD ROMs and transmission type media such as digital and analogue communications links.
FIG. 2 is a flow diagram that shows steps used to carry out object creation and object address encryption. In block 205, an application program (i.e., one of application programs 185) instantiates an object via interaction with storage management 170. AS/400 computer systems use the virtual memory architecture known in the industry as single level store (SLS). In SLS computer systems, the virtual addresses that are associated with allocated space within computer system memory are said to be persistent, which means that the virtual address used to access an instantiated object never changes. As is well known in the art, other computer system memory architectures do not involve persistent virtual addresses. Instead, virtual address are more transient, which means that multiple accesses to a single object are not always made using the same virtual address. This distinction is discussed here to make clear that the benefits and advantages of the present invention are not limited to an SLS memory architecture. Irrespective of whether an object is instantiated in an SLS environment or in a non-SLS environment, the accessing entity (i.e., the client) must nevertheless access the object via a virtual address. The fact that a virtual address is always used means that there will always be an opportunity to encrypt or decrypt the address, as is taught herein.
When storage management 170 is invoked by an application program block 205!, storage management 170 proceeds to allocate memory within the computer system memory of computer system 100 and pass the virtual address associated with the beginning of this space (i.e., the object address) to encryptor 180 block 210!. Encryptor 180 then proceeds to encrypt the passed object address and return the encrypted object address back to storage management 170 block 220!. When storage management 170 receives the object address from storage management 170 it returns the encrypted object address and control of CPU 105 to the instantiating application program blocks 215 and 220!.
FIG. 3 is a flow diagram that shows steps used to carry out object address decryption and object access, according to the preferred embodiment of the present invention. When a client wishes to access the data controlled by a server object, it invokes method call manager 175. When invoking method call manager 175, the client furnishes identification information about which server object method program is to be executed and the object address of the server object itself. As previously mentioned, method call manager 175 is used in the preferred embodiment as a supervisory mechanism to control client calls to server objects. This step is denoted on FIG. 3 as block 300. Method call manager 175 then invokes encryptor 180 and passes encryptor 180 the object address that it received from the client block 310!. Encryptor 180 responds by decrypting the passed object address and returning the decrypted object address to method call manager 175 block 325!. Method call manager 175 then invokes the called method using the decrypted object address. Once the called method has finished executing, it returns control to method call manager 175 block 330!. Method call manager 175 then returns control to the client block 335!.
Advantages
The present invention provides an enhanced mechanism that limits access to object data to only the methods of the subject object. This has the advantageous affect of enforcing object encapsulation.
The present invention also provides an enhanced mechanism for enforcing object encapsulation that does not depend upon specialized hardware or upon any one memory architecture.
The embodiments and examples set forth herein were presented in order to best explain the present invention and its practical application and to thereby enable those skilled in the art to make and use the invention. However, those skilled in the art will recognize that the foregoing description and examples have been presented for the purposes of illustration and example only. The description as set forth is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the above teaching without departing from the spirit and scope of the following claims.
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This invention relates in general to object-oriented encapsulated enforcement mechanisms. In particular, a hardware independent object encapsulation enforcement mechanism is disclosed herein. The object encapsulation enforcement mechanism of the present invention uses encryption technology to ensure that data controlled by an object is accessed solely through use of the object's method programs. When an object is instantiated, the virtual address used to refer to the object is encrypted before it is returned to the instantiating application program. When access to a previously instantiated object is requested, the object encapsulation enforcement mechanism decrypts the presented object address and passes the address to the identified method program, thereby ensuring that only object method programs have access to data controlled by the object.
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CROSS REFERENCE TO RELATED APPLICATION
The present application is a continuation of U.S. patent application Ser. No. 10/321,084, filed Dec. 17, 2002 now U.S. Pat. No. 6,926,037.
BACKGROUND
Flexible pipes currently used in offshore oil and gas fields for the transport of fluids underwater between the subsea wellhead and the surface facilities are designed to retain a circular cross-section when subject to external hydrostatic pressure. This is usually achieved by the inclusion of metallic layers which extend around and support a polymer fluid barrier layer and which resists collapsing under the external hydrostatic pressure. However, for deep water applications, the strength and the weight of the metallic layers required to resist collapse becomes a limiting factor in flexible pipe design.
Also, in these designs the innermost barrier layer is designed to contain the fluid or gas. Thus, when the pipe collapses or is squashed, the barrier wall will experience excessive localized over-bending, which can cause structural damage to the barrier layer and result in failure of the pipe.
Therefore, what is needed is a flexible pipe that can tolerate relatively high hydrostatic pressure yet eliminate the disadvantages of the metallic layers discussed above while avoiding potential structural damage to the barrier layer.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric view of a pipe according to an embodiment of the invention.
FIGS. 2A , 2 B, 3 and 4 are enlarged transverse sectional views of the pipe of FIG. 1 , depicting various collapsed modes.
FIG. 5 is an enlarged longitudinal sectional view of the pipe of FIG. 1 .
FIG. 6 is an isometric view of a pipe according to an alternate embodiment of the invention.
DETAILED DESCRIPTION
Referring to FIG. 1 of the drawings, the reference numeral 10 refers, in general, to a pipe according to an embodiment of the invention. The pipe 10 is designed to receive a fluid at one end for the purpose of transporting the fluid. The pipe 10 includes a barrier layer 12 and an inner layer 14 disposed within the barrier layer in a coaxial relation thereto, with the inner layer normally conforming to the corresponding inner surface of the barrier layer in an abutting relationship, for the entire length of the latter layer.
The barrier layer 12 can be fabricated from a material that has reasonable ductility and elasticity such as a plastic or elastic polymer. The material forming the inner layer 14 can also be a plastic or elastic polymer, and preferably is selected so that it has sufficient ductility to survive after being subjected to large strain levels a number of times, and sufficient elasticity to tend to recover from a collapsed state when the pipe is repressurized.
The wall thickness of the inner layer 14 relative to the wall thickness of the layer 12 is selected so that damage to the barrier layer 12 is prevented when both the barrier layer and the inner layer are collapsed in response to a hydrostatic load placed on the pipe. For example, and assuming the layers 12 and 14 are fabricated from a polymer material as discussed above, their relatively thicknesses are selected so that, when the pipe 10 collapses under a hydrostatic load, a maximum strain on the layer 12 will occur that is no greater than approximately 7% which is below the value that will cause damage to the barrier layer for most polymer material. Thus, the thickness of the inner layer 14 relative to the thickness of the layer 12 is selected to limit the bending of the outer layer to within safe levels of strain. In this context, it is understood that the thickness of the inner layer 14 relative to the barrier layer 12 can vary from a value in which the former is less or greater than the latter based on the relative dimensions of the layer 12 and 14 and the material of the layers. Thus, the relative thicknesses of the layers 12 and 14 shown in the drawing are for the purposes of a non-limitative example only.
FIGS. 2A and 2B depict the pipe 10 after application of an external pressure to the barrier surface of the barrier layer 12 sufficient to collapse the pipe. In the case of FIG. 2A , one area of the pipe 10 has collapsed, whereas in FIG. 2B , diametrically opposite portions have collapsed. In both cases, the outer radius R of the inner layer 14 forms a cushion that limits the bending of the barrier layer 12 at an area where the maximum strain on the barrier layer normally occurs. The thickness of the inner layer 14 is selected so that the maximum possible bending of the barrier layer 12 is limited to an amount less than the bending that would cause strain on the barrier layer sufficient to damage it.
If the external pressure acting on the pipe 10 remains sufficiently high after the initial collapse shown in FIGS. 2A and 2B , then the pipe may be further forced into a post-buckled mode shown in FIG. 3 . In this situation, one portion of the barrier layer 12 and the inner layer 14 (in the example shown, the upper halves of the layers) attain maximum deformation, and the collapse is such that the flow path through the inner layer 14 is completely closed. As in the situation of FIGS. 2A and 2B , the collapsed inner layer 14 forms a cushion with round radii R which limit the maximum possible bending of the barrier layer 12 and thus protect if from damage.
The collapse of the pipe 10 can also result in small gaps G at two ends of the cross section of the pipe, as shown in FIG. 4 . As in the situation of FIGS. 2A and 2B , the collapsed barrier layer 12 and inner layer 14 form a cushion with round radii R where the maximum strain on the barrier layer occurs. However, due to the gaps G, the radii R will be greater than the radii R in the example of FIG. 3 . As a result, relative lower strain is expected on the barrier layer 12 . By taking this phenomenon into consideration, the relative thickness of the inner layer 14 (and therefore the ratio of the inner layer thickness over the thickness of the barrier layer 12 ) can be reduced from a value used when the gaps G are not present.
In each of these situations, the inner layer 14 can suffer localized structural damage, such as crazing or localized yielding, especially after several collapses, but this damage will not affect the function of the pipe and can be tolerated. When the inner layer 14 is, in fact, damaged, it functions as a sacrificial layer.
The accumulation of permeated fluid and/or gas in the interface between the barrier layer 12 and inner layer 14 can cause separation between the barrier layer 12 and inner layer 14 prior to collapse of the pipe 10 . This separation could result in an undesirable collapse mode other than those shown in FIGS. 2 and 3 since the inner layer 14 may not be able to protect the barrier layer from over-bending and subsequent structural damage. A technique to eliminate this accumulation and thus to insure that the pipe 10 collapses properly to the collapse modes (shapes) shown in FIGS. 2 and 3 is depicted in FIG. 5 .
Specifically, a series of small radially-extending and axially and angularly-spaced holes 14 a are formed through the inner layer 14 in any known manner, such as by drilling. During operation, the holes 14 a will promote the flow of the trapped fluid/gas from the interface F, and into the interior of the inner layer 14 as shown by the solid arrows. This is caused by two effects—a “vacuum” effect due to low pressure at the inner side of the holes 14 a which is generated by the flowing fluid/gas inside the inner layer 14 in the direction shown by the dashed arrow, and a “squeezing” effect as the internal flow pressure (with possible external pressure on the outer surface of the inner layer 12 ) pushes the inner layer 14 and the barrier layer 12 against each other. This flow through the holes 14 a avoids separation of the barrier layer 12 and inner layer 14 so that they will thus remain in contact in their designed, abutting, coaxial configuration, thus avoiding the undesirable separation and enabling the pipe 10 to return from its collapsed condition to its normal condition shown in FIG. 1 .
The pipe 10 thus can tolerate relatively high hydrostatic pressures while eliminating the disadvantages of the metallic layers discussed above and avoiding potential structural damage to the barrier layer. In addition, the pipe 10 can be wound on a storage reel in a collapsed, substantially flat form, an advantage from a storage and transportation standpoint.
The pipe 20 according to an alternate embodiment is shown in FIG. 6 and is designed to receive a fluid at one end for the purposes of transporting the fluid. The pipe 20 includes a barrier layer 22 and an inner layer 24 which are identical to the barrier layer 12 and the inner layer 14 , respectively, of the previous embodiment. Thus, the inner layer 24 is disposed in the barrier layer 22 in a coaxial relation thereto, with the inner layer normally conforming to the corresponding inner surface of the barrier layer in an abutting relationship, for the entire length of the barrier layer.
A protective layer 26 extends over the barrier layer 22 , a reinforcement layer 28 extends over the protective layer 26 and an additional protective layer 30 extends over the layer 28 . Although only one layer 26 , 28 , and 30 are shown, it is understood that additional layers 26 , 28 , and 30 can be provided. The protective layers 26 and 30 can be made from plastic or elastic polymer, or plastic or elastic polymer tapes with or without reinforcement fibers. The reinforcement layer(s) can be made from metallic or composite strips with or without interlocking.
The pipe 20 thus enjoys all of the advantages of the pipe 10 and, in addition, enjoys additional protection and reinforcement from the layers 26 , 28 , and 30 .
It is understood that variations may be made in the foregoing without departing from the scope of the invention. For example, the pipe can be provided with one or more protective layers and/or one or more reinforcement layers extending over the outer layer.
The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents.
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A collapse tolerant flexible pipe and method of manufacturing same according to which an inner tubular layer is provided within an outer tubular layer in a coaxial relationship thereto. The inner layer maintains the maximum allowable strain on the outer layer below a value that will cause damage to the outer layer when the pipe collapses.
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BACKGROUND OF THE INVENTION
This invention concerns a problem specific to packet transmission networks such as the Internet. Since such networks are inherently asynchronous, routing of packets is subject to delays of indefinite duration. Hence, data requiring isochronous handling (e.g. video or voice data contained in interactive communications) may be subject to undesired distortions on arrival at destinations.
In these networks, packets are transferred from sources to network routers (transmission distribution hubs) and via the latter to respective destinations. At routers, packets are placed on queues associated with a transmission interface to the network, or more loosely an output port. After some delay (usually indefinite or indeterminate), packets are forwarded to next stations (other routers or end destinations). Such delay may be due to problems on the transmission link, traffic congestion at next stations, or other causes. Hence, as noted, data needing isochronous handling requires additional support.
In respect to the Internet, two sets of standards have been proposed for addressing problems associated with delivery of isochronous real-time services. These are:
1. Resource Reservation Protocol (RSVP), a router protocol currently an Internet draft, allowing a designated packet receiving station to send a request for priority service back along the route of the transmitted packets. At each router which is RSVP enabled, the request makes a reservation for a certain class of priority in forwarding packets; typically, a choice of a class of priority associated with one of the following quality of service (QoS) levels:
a. Best effort
b. Controlled delay (upper bound on permitted forwarding delay)
c. Predictive service (guaranteed service level for some fraction of traffic in the class)
d. Guaranteed service (predefined average bit rates)
2. Real Time Protocol (RTP) and Real Time Control Protocol (RTCP), defining methods of transmitting packets of sampled audio, video or other real-time data using a Universal Datagram Protocol (UDP). RTP defines a packet header, containing, among other things, information representing a time-stamp for the respective packet that is intended to enable a receiving station to play out the samples with correct timing and sequence. RTCP comprises sets of messages that can be exchanged between sending and receiving stations to establish and control a flow of real-time information. Although RSVP and RTP need not be used together it is likely they will be.
A problem we have recognized is that although these protocols are likely to improve handling of real-time traffic, they do not define mechanisms for guaranteeing with any degree of certainty that a network can in fact meet user requests for prioritized services. For example, when an RSVP-enabled network becomes congested, it is reasonable to expect that users transmitting real-time data would tend to request increased priority for their packets, and this in turn could tend to reduce capacities available to new traffic and lead to further increases in congestion. Our invention is directed to solving this problem; i.e. to providing a mechanism for enabling such routers to meet guarantees associated with priority classed services with a high degree of certainty, and thereby effectively ensuring that traffic subscribed to a special class of service associated with isochronous handling will receive adequate handling.
Routers and their interfaces can become congested if they are unable to forward packets as fast as they are being received. The above-referenced protocol and other protocols allow routers to discard packets in such circumstances. Normally, this is very disruptive as the destination host will detect that packets have been lost in transmission and start a transport layer protocol to request re-transmission of the missing packets, which packets would have to be re-ordered relative to previously received packets before they are passed up to the higher protocol layers. It is necessary to recover missing packets because data containing the missing data could in some instances be worthless or unuseful without it; for example, if data in missing packets is part of a data set that represents the binary image of a program or contents of a database, the set minus the missing data may not have any usefulness.
However, the type of traffic for which RSVP and RTP were created--typically, samples of real-time audio or video--is tolerant of lost packets. For such traffic, loss of packets leads at worst to momentary glitches in playout of the audio or video. The perceptual degradation associated with such glitches is often acceptable provided only a small fraction of packets are lost. In many cases, codecs which recreate uncompressed streams of data representing audio or video functions can fill in missing data. Thus, it is acceptable to routinely discard packets from this type of traffic as a management strategy.
SUMMARY OF THE INVENTION
Our invention is a Quality of Service (QoS) control mechanism--for use e.g. in network routers--that enables network service providers to offer priority classes of service with special guarantees to real-time users (based on usage fees imposed on the users) and to meet respective guarantees with a high degree of certainty. This mechanism--which preferably would be implemented as software applications executable on general purpose computers, but also could be implemented in special purpose hardware--is designed specifically to ensure with a high degree of certainty that prioritized data will be delivered with isochronous timing; the degree of certainty increasing progressively for progressively higher levels of priority.
This mechanism has as main components in each enabled router: (a) an array of prioritized packet forwarding queues; (b) a QoS manager; (c) a packet prioritizing element; and (d) a prioritized packet forwarding element.
The QoS manager acts in response to requests routed through the network to assign incoming traffic to prioritized service levels associated with prioritized forwarding queues in the router, to monitor traffic congestion conditions locally in the forwarding queues, and to restrict admission of new flows into the queues when necessary to counteract congestion. Monitoring of congestion in the queues is achieved by having incoming packet flows time stamped as they enter the queues, sampling time stamps at appropriate intervals, and calculating average forwarding delays by subtracting sampled time stamps from a representation of current time and averaging the results over time.
The packet prioritizing element steers incoming packets to forwarding queues appropriate to their reserved classes of service (to a lowest priority queue if the packets do not have service reservations). If priority queues can accept additional traffic because they are being under-utilized, traffic in lower priority queues is transferred to the under-utilized queues. This effective promotion of lower priority traffic is maintained until all queues are operating just below their thresholds of congestion. The thresholds of congestion are associated with operating states in which queues are not actually congested but could become so with moderate increases in their loads.
The queue monitoring process conducted by the QoS is able to distinguish when queues are operating below and above their thresholds of congestion, as well as when queues are in a critical state of congestion well above that threshold.
The packet forwarding element is responsible for transferring traffic from the prioritized forwarding queues out to the network, and via the latter to next routers/stations. In this process packets are transferred preferentially from the highest priority non-empty queue, and dummy packets allocated to service levels associated with individual queues is inserted into the outbound traffic when forwarding rates from respective queues allows it; i.e. while respective queues are operating below their thresholds of congestion. Dummy packets have a form requiring network stations and routers receiving them to immediately discard them.
The dummy packets, and other forms of filler traffic explained herein, are used presently as a type of "discardable ballast" enabling the present QoS manager to precisely control congestion in the queues, even when causes of congestion are external to the respective router. The QoS manager allows for an initial or nominal rate of flow of dummy traffic relative to each queue (e.g. 10% of the capacity allocated to the service class corresponding to the respective queue's priority). Dummy traffic for each queue is discardable as real traffic occupying the queue increases to a level requiring such displacement.
Filler traffic other than dummy traffic is promotable up to a priority queue, from a queue of lower priority, while the queue is operating below its threshold of congestion. As noted above, the QoS manager is able to detect when a queue is operating in a critical state of congestion well above its threshold of congestion. While that state persists, forwarding of promoted filler traffic in the affected queue is suspended, thus allowing only unpromoted real traffic in the queue to be forwarded out to the network. At such times, admission of new incoming traffic that would go directly into the congested queue is also suspended. Such actions are expected to quickly reduce congestion (since some of the transmission associated with previously admitted traffic will be concluding), so that reductions in new traffic admission are expected to occur infrequently and last for very short intervals of time during station operations.
It is characteristic of many systems employing prioritized queues that as the traffic load on a queue increases from zero, the forwarding delay in the queue increases gradually and linearly at first, but beyond some threshold the delay increases very rapidly and non-linearly leading to congestion of the queue. The graph of forwarding delay versus queue load associated with this characteristic behavior is often called a "hockey-stick" curve because of its shape.
In a large network the volume of traffic at which this forwarding delay begins increasing non-linearly is difficult to predict and may vary depending on several factors in both the router and in the network in which the router is operating. In a lightly loaded network, the forwarding delay in a router is often very small, a few milliseconds, but can rise quickly to hundreds of milliseconds in congested conditions. While the volume of traffic which can cause congestion is not well defined, the bend between the linear and non-linear parts of the hockey stick curve is easily discerned, and a point in that bend representing the upper bound of linear increase in average forwarding delay is reasonably determinable. In this invention this upper bound representation is used to represent a threshold of congestion. When a queue is operating below that threshold in the present system it is deemed capable of handling both new incoming traffic and promoted filler traffic.
As noted earlier, the present QoS mechanism monitors the average forwarding delay in the queues, and determines when queues are operating above and below their threshold of congestion, as well as when queues are in a state of potentially critical congestion. While queues having other than a lowest priority are are operating below their threshold of congestion, this mechanism transfers/promotes filler traffic into the respective queue from lower priority queues. While queues are operating above their threshold of congestion but not in the above-mentioned state of potentially critical congestion, promoted filler traffic is moved/demoted to lower priority queues. When queues reach the potentially critical state, this mechanism acts to suspend admission of new incoming traffic into the queue and also suspends forwarding of filler traffic from the queue out to the network, allowing only traffic occupying the queue as other than filler traffic to be forwarded (i.e. allowing only traffic having a service reservation class corresponding to or greater than the queue's priority level to be forwarded).
These actions serve to regulate the flow through the priority queues so that traffic associated with a corresponding level of service is subject to being forwarded with less forwarding delays than any other traffic in the respective queue or in any lower priority queue. Thus, promoted filler traffic and dummy traffic associated with each priority queue serves as a kind of discardable ballast that keeps the queue operating efficiently when it is uncongested and to minimize forwarding delays encountered by traffic having service reservations entitling them to at least the priority of the respective queue.
This usage is described further in the detailed description below, and charts/graphs used to support that description should clarify many of the functions alluded to above.Thus, these charts and the following description should clarify how the regulating effects suggested above are actually achieved. They should show also that addition of filler traffic to non-congested queues leads to a small but acceptable forwarding delay, which is fully compensated for by the ballast effect associated with use of the filler traffic to counteract states of congestion. Thus, it will be seen that under less than extreme conditons of congestion, the router is able to comfortably accept reservations for more incoming priority traffic flow without detriment to the flow of existing real traffic; notwithstanding the promotions of filler traffic into the queues, and that only under more critical conditionst will the router be required to suspend admission of new incoming traffic to its queues.
As noted above, dummy filler traffic for each class of priority service supported at a station may be set initially to a predetermined fraction of the station's estimated capacity for that class; e.g. 10%. The estimate of forwarding capacity and the fraction thereof allocated to dummy filler traffic need not be exact since they are improved iteratively in the course of operating the station. Since real-time traffic (traffic requiring guaranteed isochronous handling) is expected to use a small fraction of a router's capacity, the presently contemplated interspersal of dummy filler traffic in the priority queues should not seriously reduce the capacity available to real traffic.
Structures and operations of elements of the subject mechanism, and other features, advantages and benefits of the invention, will be more fully understood by considering the following detailed description and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic of a network designed to use the present invention.
FIG. 2 is a block diagram of the subject QoS mechanism.
FIG. 3 indicates how dummy packets (packets void of significant data) are differentiated from other packets (packets containing significant data).
FIG. 4 is a flow diagram for explaining operations of the subject mechanism, relative to a priority queue associated with highest priority handling, in a generalized context.
FIG. 5 is a flow diagram for explaining details of a "filler insertion" process suggested in a generalized context in FIG. 4.
FIG. 6 is a flowchart for explaining how forwarding delays in present queues are monitored as indications of congestion which may be caused by network conditions external to present routers.
FIG. 7 is a graph for explaining how forwarding delays in present queues tend to vary non-linearly as traffic flow into respective queues approaches a threshold level.
FIG. 8 is a graph similar to FIG. 6 for indicating how the manipulations of filler traffic characterized in FIGS. 4 and 5 serves as a ballast or buffer enabling the present control mechanism to efficiently control traffic flow into present queues.
FIG. 9 is a time-based graph for explaining how the present invention deals with various stages of congestion in the queues.
DETAILED DESCRIPTION
1. Background
FIG. 1 shows a packet routing network designed to use the subject invention. End stations 1, 2 represent sources and destinations of real (non-ummy) traffic. Intermediate stations 3 represent packet routers or distribution hubs, each containing a QoS mechanism constructed in accordance with the present invention. Communication links between stations are suggested at 4 and 5; 4 showing links between pairs of illustrated stations, and 5 suggesting links between illustrated and unillustrated stations. As seen at 6, each router 3 supports "n" priority classes of service (n being an integer greater than 1) wherein class 1 is the lowest priority class ("best efforts" handling) and class n is the highest priority class (best guaranteed time of delivery per packet). The specific value of n is not considered relevant to our invention.
The purpose of the invention is to provide each router with a Quality of Service (QoS) system/mechanism router that will ensure with varying degrees of certainty that service guarantees associated with priorities greater than 1 are consistently met. With this invention, the degree of certainty increases progressively for services having progressively increasing priorities. The mechanism is designed specifically to ensure that guarantees associated with service priorities accorded to transmissions requiring isochronous handling are consistently met.
Each router contains programmable digital data processors of a standard form, and it should be understood that the subject system/mechanism can be implemented either as (new) application software executable by these processors or by means of special hardware augmenting these processors.
2. The QoS System
FIG. 2 is a block diagram of the QoS mechanism. As shown here, the mechanism contains as principal elements or components: arrays of forwarding queues 10, a QoS manager element 11, a packet prioritizer element 12 and a prioritized packet forwarder element 13.
QoS manager 11 controls assignment of incoming traffic 14 to priority classes, sets initial rates of dummy traffic (which may be varied iteratively as the station's history of traffic becomes known), monitors forwarding delays of traffic in the queues as indications of congestion (even when the congestion may be due to network conditions external to the respective router), uses forms of filler traffic explained later to keep uncongested queues optimally occupied while allowing for detected states of congestion in the queues to be efficiently counteracted, and restricts admission of new traffic when necessary to compensate for detected critical states of congestion.
While queues are operating in other than a critical state of congestion described later, packet prioritizer 12 routes incoming packet traffic 15 (other than incoming dummy traffic which is immediately discarded) into forwarding queues 10 suited to priority levels if any reserved to respective traffic flows. However, the invention tries to maintain constant "optimal" occupancy at each priority level by iteratively promoting traffic from lower priority queues to higher priority queues while the latter are operating below a threshold of congestion described later.
States of approaching/imminent congestion and criticall congestion are detected by monitoring the forwarding delay in each queue in a manner described below. When a state of approaching congestion is detected in a queue, traffic is demoted from the respective queue to lower priority queues in order to relieve the congestion in the respective queue and thereby ensure that incoming new traffic with a service reservation for the respective queue is not unnecessarily blocked from being serviced. While a queue is in a state of critical congestion admission of new traffic flows into the queue is suspended until the state of critical congestion ends.
Forwarding element 13 forwards packets from the queues and dummy packets associated with individual queues to output transmission interfaces 16 of the router.
3. Form of Dummy Packets
FIG. 3 shows how dummy packets are differentiated from other traffic. All packets are assumed to have a data portion 20 and header portion 21, the latter containing characters defining controlling functions required in the handling of the respective packet. In this figure, it is assumed that data packets are sent in the TCP/IP (Transmission Control Protocol/Internet Protocol) format used on the Internet. In that protocol, the header contains a "Time to Live" field 22. In accordance with the present invention, this field is set to 0 in transmitted dummy packets so that such packets are immediately discarded at routers and other stations receiving them. It should be understood, however, that dummy packets could be sent in any format containing a header or control field settable to a value causing respective packets to be discarded on reception.
4. Operations of the QoS Mechanism
Remaining figures of drawing (FIGS. 4 and higher) are used to explain operations of the subject mechanism.
FIG. 4 is a flowchart for explaining operations performed relative to queues 10 having highest priority n, such queues hereafter being denoted as "Qn", FIG. 5 is a flowchart for explaining details of an "add filler" operation shown in general form in FIG. 4, and FIG. 6 is a flowchart for explaining how congestion conditions are detected in queues such as Qn and how various controlling actions are evoked to specifically counteract such conditions (even when the cause of the condition is external to the respective router).
Referring to FIG. 4, router interfaces for incoming and outgoing data must be initialized (operation 30) before requests for reservations of service in highest priority class n can be processed. Interfaces are initialized when the router is first powered on or re-started. Logic at each interface is reset and link layer protocols establish communication with neighboring routers connected to the interfaces. When the interfaces are ready the router notifies its neighbors and the network topology is modified to include this router in tables that are used to compute routes for forwarding packets through the network.
When an application in a host terminal of the network determines that it needs a class of service at a particular priority level for a particular flow of packets (a stream of packets having a common origin and destination), a reservation protocol such as RSVP is used. A request for the required class of service is sent to each router along a defined path between the destination and source of the projected flow. Requests for these reservations, contained in special message packets conforming to the reservation protocol, are processed by QoS managers such as 11 (FIG. 2). Block 31 in FIG. 4 represents the processing of such requests directed specifically to services at priority class n. In this transaction, the reservation message requests to have a flow of one or more packets forwarded through the router at priority level n. If the request is accepted, the respective flow of packets is directed through Qn with preferential treatment relative to other packets in the same queue that are entitled to lesser priority handling as explained below.
Such prioritized packet flows--which may, for example, contain real-time audio or video data streams--are characterized in terms of their size (number of packets) and an average or peak rate of arrival of its packets. When the requesting application has negotiated a set of reservations to meet its needs, it starts one or more flows of packets through the route pre-negotiated, and routers at each stage of the route are obliged to handle the packets with appropriate priority (e.g. flows reserved to class n must be forwarded with highest priority through Qn.
It should be understood that flows of incoming real (non-dummy) data packets are subject to default handling at lowest priority level 1 ("best efforts") if a reservation is not made in advance for having them handled at a higher priority level.
For reservation requests that are granted, all subsequent associated packets received at the station are handled in accordance with the priority stipulated in respective reservation requests. Thus, received packets associated with a previously granted priority n request are scheduled to be placed directly on Qn, and received packets entitled to lesser priority service are placed initially on queues having priority lower than n.
A difficulty with such reservation schemes in prior systems was that the router generally had no way to know if it could afford to accept another reservation. This is because, as noted in the Summary of Invention section, the inflection of the hockey stick curves shown presently in FIGS. 7 and 8 need not occur as a consequence of conditions purely local to the router. Rather, the onset of congestion depends on both local conditions and conditions elsewhere in the network. While one could imagine global management schemes to oversee such conditions, we believe that global schemes would be very complex and potentially unstable. Therefore, in this invention we employ a purely local mechanism to provide a reserve of capacity that can be applied in case increasing priority traffic leads to approaching congestion, and to provide additional regulating actions tending to counter-act real congestion. This reserve is normally consumed by the filler traffic including dummy packets, but is quickly recoverable by discarding the filler traffic.
In the present reservation process (31), QoS manager 11 determines (operation 32) if average forwarding delays currently incurred by packets in transit through Qn are greater than a predetermined first threshold level 1. This is achieved by QoS manager operations described below relative to FIG. 6. Briefly, these operations sample time stamps inserted into accepted flow reservations admitted to Qn (the time stamps may be applied by packet prioritizer 12 in the course of handling its responsibilities). The sampling is at predetermined intervals. Periodically, say five times per second, the QoS manager scans time stamps in the queue, and subtracts them from the current actual time to calculate associated forwarding delays which are averaged to obtain an indication of current average forwarding delay in the respective queue (in FIG. 4, Qn). This average delay is compared to a definable threshold level 1. In FIG. 7, for instance, this threshold level 1 is approximately 10 milliseconds (in actual practice, the curve shape could yield a threshold between 10 and 30 milliseconds), which for the illustrated graph represents approximately the upper bound for the linear part of the delay curve and thus represents the possible onset of rapidly approaching congestion since the delay could could quickly rise to perhaps hundreds of milliseconds if the queue contents are not forwarded at a suitable rate.
If the average forwarding delay monitored in this fashion exceeds a second threshold level 2 greater than threshold level 1 (approximately 80 to 100 milliseconds for the curve shown in FIG. 7), it may be understood that the interface to the respective priority level is nearing a critical state of congestion.
Returning to consideration of FIG. 4, if decision 32 indicates an average forwarding delay in Qn less than first threshold level 1, the QoS manager determines next (decision 33) if the interface has been marked congested. The interface will have been so marked if on a previous execution of this process the average forwarding delay had been found to exceed threshold 1.
If the interface has not been marked congested ("N/no" determination at step 33), an additional unit of packet flow if available can be moved/promoted to Qn from a lower priority queue by means of the process indicated generally at 34 and explained in detail later with reference to FIG. 5. This additional traffic from lower priority queues is termed "filler" flow since its purpose while in Qn is to keep that queue filled to an efficient level.
The unit of filer flow for the (promotional) movement associated with block 34 is a flow reservation currently held in a next lower priority non-empty queue (Qn-1 if it is not empty, Qn-2 if it is not empty and Qn-1 is empty, and so on).
If the interface is found to have been marked congested at decision stage 33, it's marking is reversed to indicate a non-congested state (operation 35).
After either operation 34 or operation 35, processing of requests for priority service (operation 31) resumes
If the average forwarding delay examined at decision stage 32 is greater than threshold 1 ("Y/yes" determination at 32), the QoS manager moves a unit of filler flow from Qn to Qn-1 (operation 36) and marks the class n interface congested (operation 37). Here again the unit of filler flow is a flow reservation for a class of service lower than n. The filler flow moved to Qn-1 is effectively demoted to lesser priority handling as a result of this action, and the effect is to potentially make room in Qn for admission of additional traffic entitled to class n service at a reception interface of this router (i.e. the effect is to potentially lessen congestion at the class n interface).
After these operations, the QoS manager determines (decision 38) if the average forwarding delay currently exceeds threshold level 2, which is considerably greater than threshold 1 and is associatable with a state of actual congestion in Qn. If the delay exceeds threshold 2 (Y determination at 38) , all filler flow in Qn is dropped (operation 40) and the packet prioritizer (element 12, FIG. 2) begins discarding incoming packets having reservations for class n handling (operation 41). Discarded packets are saved (as suggested at 17, FIG. 2) but not entered into the forwarding queue. Accordingly, this tends to degrade handling of incoming packets entitled to class n service for the (usually brief) duration of the congested condition.
If the average delay is not greater than threshold 2 at decision 38 (decision N), the QoS manager acts to halt any discarding of incoming packets (operation 42) which may have been started previously; e.g. in a prior execution of the foregoing process and operation 41.
Details of the process performed to add/promote filler flow to Qn from a lower priority queue (operations 34, FIG. 4) are shown in FIG. 5. In FIG. 5, start and end terminators 48 and 49 respectively represent the entry to and exit from block 34 in FIG. 4.
This process starts with an examination of the state of Qn-1 (decision 50). If Qn-1 is not empty--i.e. if there is at least one traffic flow reservation at priority n-1--a flow reservation is moved from Qn-1 to Qn (operation 51). If Qn-1 is empty at step 50, the state of Qn-2, is examined (step 53). If Qn-2 is not empty, a flow reservation is moved from it to Qn (operation 34). As suggested by dotted lines from step 52 downward, if Qn-2 is empty this process continues through lesser priority queues in succession, down eventually to the lowest priority queue Q1, allowing for promotion of a traffic flow from the non-empty queue closest in priority rank to Qn.
If all lesser priority queues are empty when determinations 50, 53, . . . , 56 are made, dummy traffic associated with Qn is generated (operation 58) to correspond roughly to the traffic of a unit of flow reservation at the lowest priority level. This dummy traffic can be entered into Qn as filler traffic. As noted earlier, the amount of dummy traffic so generated at each queue is limited to a predetermined fraction of estimated peak traffic through the queue, and the limit can be changed iteratively as the router is used. The router can determine an appropriate volume for such traffic by randomly picking a flow reservation at priority level 1 and using its parameters. Dummy traffic consists of conventional size packets that are identified as dummy traffic by having their Time To Live fields set to zero (see FIG. 3). Consequently, dummy packets generated in this router are immediately discarded by routers to which they are sent.
The above processes of FIGS. 4 and 5 relative to Qn are applied successively to each lower priority queue (Qn-1, Qn-2, etc.); i.e. traffic in each lower priority queue is regulated by promotion of filler and dummy traffic, until the queue reaches its threshold of congestion, demotion of filler traffic when the queue passes that threshold, and further actions when the queue reaches the critical congestion state associated with threshold level 2. Consequeuently, each queue on the average should carry a maximum load of real, filler and dummy traffic keeping the queue operating near its threshold of congestion.
At each queue, action is taken to counteract states of near and critical congestion. While average forwarding delays are between threshold 1 (the "threshold of congestion") and threshold 2 (the threshold of "critical congestion") filler flows are demoted to lower priority queues, and while average forwarding delays are greater than threshold 2, forward handling of filler traffic and admittance of new incoming traffic are suspended.
FIG. 6 shows details of how functions 38 and 40-42 in FIG. 4 are accomplished. The packet prioritizer inserts time stamps into units of class n flow that are placed in Qn as well as units of class i flow (i<n) placed in respective queues Qi (operation 60). The QoS manager periodically samples these stamps, subtracts the samples from current actual time and averages the results to yield the average forwarding delay in each queue. If the average forwarding delay is less than threshold level 1 (N determination at decision 62) action 63 is evoked corresponding to action 33 in FIG. 4. If the average forwarding delay is greater than threshold 1 but less than full congestion threshold 2 (Y determination at 62 and N determination at 64) action 65 (corresponding to action 36 in FIG. 4) is evoked. If average forwarding delay is greater than threshold 2 (Y determinations at both 62 and 64) action 66 (corresponding to action 40, FIG. 4) is evoked.
FIG. 8 is a graph with hockey stick shaped curve, similar to the graph in FIG. 7, but indicating further how threshold levels 1 and 2 are reasonably determinable. The line designated "Threshold of Congestion" in both FIGS. 7 and 8 represents an approximate middle position in the bend between the flat, linear and slowly rising part of the curve and the non-linear fast-rising part of the curve. This position then can be treated as a threshold 1 of "non-critical" congestion, and a line drawn through the steep end of the bend can be used to define a threshold 2 of critical congestion.
FIG. 9 shows how this invention deals with various stages of congestion in any queue. Starting from an initial low level of filler traffic in the queue (time interval 1), the QoS manager accepts flow reservations for this queue. This increases the volume of traffic through the queue over successive intervals of time (intervals 2 and 3), and the average forwarding delay begins to rise. In interval 4, the average forwarding delay exceeds threshold level 1 causing the QoS manager to demote filler traffic out of the queue. This causes the average forwarding delay to fall and eventually drop below threshold 1, whereupon the promotion of filler traffic up to the queue resumes (intervals 5 through 7).
During interval 8, some significant perturbation of the network causes a rapid increase in average forwarding delay in this queue to above threshold level 2 associated with critical congestion. The QoS process now suspends forwarding of filler traffic out of the queue and starts to discard new incoming packet flows that would normally flow into this queue. This leads to a reduction in average forwarding delay. The interface may remain congested, but the process stops discarding packets (interval 9). Finally, in interval 10, the interface is no longer congested (average forwarding delay has fallen below threshold level 1) and the process begins to promote filler traffic again to the respective queue.
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A packet router for a data packet transmission network, wherein routers offer priority services of the type required for isochronous handling of data representing real-time voice, includes a Quality of Service (QoS) management system for ensuring that guarantees associated with such priority service can be met with a high degree of certainty. This management system provides prioritized queues including a highest priority queue supporting reservations for the priority service suited to isochronous handling. The highest priority queue and other queues are closely monitored by a QoS manager element for states of near congestion and critical congestion. While neither state exists, filler packet flows are promoted from lower priority queues to the highest priority queue, in order to keep the latter queue optimally utilized. If all lower priority queues are empty at such times, dummy packets are inserted as filler flows. Dummy packets have a form causing routers and other stations receiving them to immediately discard them. The volume of dummy traffic allowed for each queue of the system is a predetermined fraction of the queue's estimated peak traffic load, and that volume is displaceable to allow forwarding of additional traffic through the queue when conditions require it. While a state of near congestion exists, the QoS manager demotes filler flow units from the highest priority queues to lower priority queues, in order to lessen the potential forwarding delays presented to real traffic occupying the highest priority queue. When a state of critical congestion exists in the highest priority queue, admission of new incoming traffic flows to that queue is suspended and forwarding of filler flows from that queue out to the network is also suspended.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 09/698,934 filed Oct. 27, 2000, entitled “Retaining Wall Anchoring System”, now U.S. Pat. No. 6,652,196, which is a continuation of U.S. patent application Ser. No. 09/261,420, filed Mar. 3, 1999, now U.S. Pat. No. 6,168,351, entitled “Retaining Wall Anchoring System”, which is a continuation-in-pan of U.S. application Ser. No. 08/846,440, filed Apr. 30, 1997, now U.S. Pat. No. 5,921,715, entitled “Retaining Wall and Method” and which claims the benefit of the filing date of U.S. Provisional Application Ser. No. 60/086,843, filed May 27,1998, entitled “Retaining Wall Anchoring System”, all of which are incorporated herein by reference.
FIELD OF THE INVENTION
The invention relates generally to earth reinforcement. More particularly, the invention relates to a segmental retaining wall anchoring system for securing segmental retaining walls.
BACKGROUND OF THE INVENTION
Segmental earth retaining walls are commonly used for architectural and site development applications. Such walls are subjected to very high pressures exerted by lateral movements of the soil, temperature and shrinkage effects, and seismic loads. Therefore, the backfill soil typically must be braced with tensile reinforcement members.
Often, elongated structures, commonly referred to as geogrids or reinforcement fabrics, are used to provide this reinforcement. Geogrids often are configured in a lattice arrangement and are constructed of a metal or polymer, while reinforcement fabrics are constructed of woven or nonwoven polymers (e.g., polymer fibers). These reinforcement members typically extend rearwardly from the wall and into the soil. The weight of the soil constrains the fabric from lateral movement to thereby stabilize the retaining wall.
SUMMARY OF THE INVENTION
Briefly described, the present invention relates to a retaining wall anchoring system for a segmental retaining wall comprising a plurality of tieback rods adapted to be embedded into soil or rock with a proximal portion extending therefrom. The system includes at least one elongated force distribution member positionable directly adjacent the proximal portion of the tieback rods, at least one washer positionable about the proximal portions of at least one tieback rod in abutment with the force distribution member, and at least one fastener fixedly securable to the proximal portion of the tieback rod to securely clamp the washer against the force distribution member such that tensile forces imposed on the tieback rod are transmitted to the distribution member so as to distribute these forces throughout a portion of the retaining wall.
The above described apparatus therefore can be used to construct a segmental retaining wall system comprising a retaining wall having a plurality of wall blocks stacked in ascending courses with a plurality of the wall blocks being provided with interior openings that are aligned with each other to form an inner passageway within the retaining wall. The proximal portion of each tieback rod can be extended into the inner passageway formed within the retaining wall with the elongated force distribution member positioned within the inner passageway directly adjacent the proximal portion of at least one of the tieback rods, a washer positioned about the distal portion of the tieback rods in abutment with the force distribution member, and a fastener fixedly secured to the proximal portion of the tieback rods to securely clamp the washer against the force distribution member such that tensile forces imposed on the tieback rods are transmitted to the force distribution member so as to distribute the tensile forces throughout a portion of the retaining wall.
In addition, the apparatus can be used to construct a segmental retaining wall system comprising a retaining wall having a plurality of wall blocks stacked in ascending courses to form an interior surface and an exterior surface, a plurality of tieback rods adapted to be embedded into soil or rock with a proximal portion extending therefrom, the proximal portion of each tieback rod extending toward the interior surface of the retaining wall, at least one elongated force distribution member positioned adjacent the interior surface of the retaining wall and directly adjacent the proximal portion of at least one tieback rod, a washer positioned about the distal portion of the tieback rod in abutment with the force distribution member, a fastener fixedly secured to the proximal portion of the tieback rod to securely clamp the washer against the force distribution member, and a reinforcement member connected to the force distribution member and being securely attached to the retaining wall such that tensile forces imposed on the tieback rods are transmitted to the force distribution member and through the reinforcement member to the retaining wall so as to distribute the tensile forces throughout a portion of the retaining wall.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view of a retaining wall secured with an anchoring system constructed in accordance with the present invention.
FIG. 2 is a partial cross-sectional view of a retaining wall which shows a tieback connection of an anchoring system constructed in accordance with the present invention.
FIG. 3 is a partial cross-sectional view of a retaining wall secured with an anchoring system constructed in accordance with the present invention.
FIG. 4 is a partial cross-sectional view of a retaining wall which shows a tieback connection of an anchoring system constructed in accordance with the present invention.
DETAILED DESCRIPTION
Referring now in detail to the drawings, in which like numerals indicate corresponding parts throughout the several views, FIG. 1 illustrates a modular retaining wall 10 secured with a first embodiment 12 of an anchoring system constructed in accordance with the present invention. As depicted in this figure, the retaining wall 10 comprises a plurality of wall blocks 14 that are stacked atop each other in ascending courses 16 . When stacked in this manner, the wall blocks 14 together form an exterior surface 18 of the wall 10 which faces outwardly away from an earth embankment, and an interior surface 20 of the wall 10 which faces inwardly toward the embankment (FIG. 3 ). Typically, the blocks 14 are stacked in a staggered arrangement as shown in FIG. 1 to provide greater stability to the wall 10 .
Generally speaking, the blocks 14 are substantially identical in size and shape for ease of block fabrication and wall construction, although it will be understood that unidentical blocks could be used, especially for cap blocks or base blocks. In a preferred configuration, each block 14 is configured so as to mate with at least one other block 14 when the blocks are stacked atop one another to form the retaining wall 10 . This mating restricts relative movement between vertically adjacent blocks in at least one horizontal direction. To provide for this mating, the blocks 14 can include locking means 22 that secure the blocks together to further increase wall stability. More particularly, each block 14 can include a lock channel 24 and a lock flange 26 that are configured so as to positively lock with each other when the blocks 14 are stacked on top of each another as disclosed in co-pending U.S. application Ser. No. 09/049,627, which is hereby incorporated by reference into the present disclosure. When the blocks 14 include lock channels 24 and flanges 26 , the individual lock channels typically form a continuous lock channel that extends the length of the lower of two mating courses when the blocks are aligned side-byside within each course 16 . Similarly, the lock flanges 26 form a continuous lock flange that extends the length of the upper of the mating courses 16 which is received by the continuous lock channel of the lower of the mating courses.
Although the blocks 14 preferably are provided with such locking means 22 , it will be appreciated that the anchoring system of the present invention can be used with substantially any segmental retaining wall blocks. By way of example, the present system could be used with any of the blocks produced by Anchor Wall Systems, Inc. such as any block of the Anchor Diamond® and/or Anchor Vertica® product lines, or any block disclosed in U.S. Pat. No. 5,827,015, which is hereby incorporated by reference into the present disclosure. Moreover, the present system could be utilized with the segmental blocks produced by other manufacturers such as Keystone, Mesa, Versa-Lok, Newcastle, and Piza. Irrespective of the particular configuration of the wall blocks 14 , each of the wall blocks typically includes an interior opening 32 that either extends through the block horizontally (side-to-side) or vertically (top-to-bottom). When the blocks 14 are correctly aligned in their respective courses 16 , these openings 32 form continuous elongated passageways 34 . In that, as described below, the passageways 34 typically are only used for anchoring system attachment, it is to be appreciated that only the blocks 14 that receive the system's components need be provided with such openings 32 .
As indicated in FIGS. 1-3 , the retaining wall 10 is secured in several predetermined points with tieback connections 36 . Typically, each tieback connection 36 is spaced approximately 10 feet apart horizontally from each other to form rows of tieback connections that are approximately 2.5 feet apart vertically from each other. Accordingly, each tieback rod 38 is embedded into the soil and/or rock in these intervals. As shown in FIG. 2 , each tieback rod 38 extends through an opening 39 formed in the rear surface of its respective wall block 14 such that a proximal portion 40 of the rod 38 extends into the continuous elongated passageway. Also positioned within the passageway 34 is a tieback rod attachment mechanism 42 . The attachment mechanism 42 normally includes a pair of elongated force distribution members 44 , 46 that extend from one tieback rod 26 to the next along the passageway 34 and which are positioned above and below the tieback rods 38 as indicated in FIG. 1 . Typically, each force distribution member 44 , 46 comprises an elongated channel beam that is flanged so as to cooperate more readily with washers described below. Arranged in this manner, each passageway 34 having tieback rods 38 extending therein includes a plurality of force distribution members 44 , 46 aligned end to end both above and below the rods. To maintain parallel spacing between the force distribution members 44 , 46 , the attachment mechanism 42 can include spacers 47 that are positioned adjacent each rod 38 on both sides of the rod as indicated in FIG. 1 . Normally, the height of these spacers 47 generally approximates the diameter of the tieback rods 38 .
As shown in FIG. 2 , a pair of flanged washers 48 , 50 partially surround the upper and lower pairs of force distribution members 44 and 46 , and are fitted about each tieback bar 38 . To accommodate the rearmost 50 of the washers, each wall block 14 accommodating a tieback rod 38 normally is provided with an inner channel 54 that is sized and configured for receipt of the washer 50 . Threaded onto each tieback rod 38 is a conventional threaded fastener 56 such as a nut which, when fully tightened, urges the washers 48 , 50 inwardly to securely hold the force distribution members 44 , 46 in position, thereby securing the rod to the wall 10 . Normally, this tightening is achieved by accessing the interior of the block 14 by removing a face covering portion 57 of the block. Once fully tightened, the fastener 56 can be bonded in place with epoxy to prevent its inadvertent loosening. After the fastener 56 has been fixed in place, the face covering portion 57 of the block 14 can be secured to the block so that it matches the other blocks forming the wall. Configured in this manner, each tieback connection 36 evenly distributes any forces exerted on the tieback rods 38 throughout the wall 10 to greatly improve wall integrity.
FIG. 4 illustrates a second embodiment 58 of an anchoring system constructed in accordance with the present invention. This embodiment is structurally similar to the system depicted in FIGS. 1-3 and described above. Accordingly, the force distribution members 44 , 46 , flanged washers 48 , 50 , as well as the fastener 56 , are used to secure the tieback rods 38 to the wall 10 . However, in this embodiment, the rods 38 are secured with a reinforcement member 60 such as a geogrid wrap instead of directly to a wall block 14 such that the reinforcement member 60 is positioned outside of but adjacent to the interior surface 20 of the wall. Because of this arrangement, the blocks 14 need not comprise interior openings 32 , as in the first embodiment. Preferred for the construction of the reinforcement member 60 is geogrid material that comprises flexible fabric composed of a polymeric material such as polypropylene or high tenacity polyester. As shown most clearly in FIG. 4 , the reinforcement member 60 extends from the exterior surface 18 of the retaining wall 10 , into a lock channel 24 of the lower adjacent wall block 14 , out from the wall and into a portion of the stone fill 62 formed between the wall and the soil and/or rock, wraps around the force distribution members 44 , 46 , and then extends back underneath the upper adjacent block 14 (into the wall), into the lock channel 24 of the upper adjacent block, and back to the exterior surface of the wall 18 , tracing a substantially C-shaped path.
In the wall system illustrated in FIG. 4 , the reinforcement member 60 is locked to the wall 10 with a pair of retaining bars 64 that are positioned in the two lock channels 24 adjacent the tieback rod 38 . These retaining bars 64 lie atop the reinforcement member 60 and holds it against the rear walls of the locking channels 24 to prevent the reinforcement member from being pulled out from the retaining wall 10 . Although such retaining means are preferred, it will be understood that other types of retaining means could be used. When a tensile force is applied to the tieback rod 38 and translated to the reinforcement member 60 , the retaining bars 64 are urged towards the rear wall of the channels 24 , locking the reinforcement member in place. Thus, like the system of the first embodiment, the anchoring system of the second embodiment similarly distributes the forces exerted by the soil and/or rock of the embankment throughout the retaining wall 10 .
While preferred embodiments of the invention have been disclosed in detail in the foregoing description and drawings, it will be understood by those skilled in the art that variations and modifications thereof can be made without departing from the spirit and scope of the invention. For instance, although the anchoring system of the first embodiment herein is described and shown in use with a retaining wall having horizontal inner passageways, it is to be appreciated that this systems easily could be adapted for use with a retaining wall having vertical inner passageways.
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A retaining wall anchoring system for a segmental retaining wall comprising a plurality of tieback rods adapted to be embedded into soil or rock with a proximal portion extending therefrom, at least one elongated force distribution member positionable directly adjacent the proximal portion of at least one of the tieback rods, a washer positionable about the proximal portions of the tieback rod in abutment with the force distribution member, and a fastener fixedly securable to the proximal portion of the tieback rod to securely clamp the washer against the force distribution member such that tensile forces imposed on the tieback rod are transmitted to the force distribution member so as to distribute these forces throughout a portion of the retaining wall.
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