Device for activating an opening mechanism and/or a closing mechanism for lockable moving parts on vehicles, such as flaps, doors or similar

Information

  • Patent Grant
  • 6696652
  • Patent Number
    6,696,652
  • Date Filed
    Monday, October 8, 2001
    23 years ago
  • Date Issued
    Tuesday, February 24, 2004
    21 years ago
Abstract
The invention relates to a device for activating an opening mechanism for lockable moving parts on vehicles. The device has a manual activator, which acts on a contact sensor (13) of a switch (12) for activation purposes. An outer skin (40) is provided on the vehicle. A part (43′) of the actual outer skin (40) is made elastically deformable (43′) and this part (43′) is used as the activator for the switch (12).
Description




BACKGROUND OF THE INVENTION




1. Field of the Invention




The invention relates to a device for activating an opening mechanism and/or a closing mechanism for lockable moving parts on vehicles. The device includes a manual actuator which, upon its actuation, acts on a switch and switches on a drive for opening or closing the movable vehicle part. Such a drive can belong to a closure which is embodied as a rotary latch. The rotary latch is secured by a locking pawl in the locking position and, upon activating the actuator, is transferred into an opening position. Such a device is, for example, used at the rear hatch of a motor vehicle.




2. Description of the Related Art




In the known device of this kind (DE 34 40 442 A1) the actuator is a pushbutton which is arranged in a hole in the outer skin. In order to secure the pushbutton in its initial position, a pressure spring is required. In order to protect the mechanism against dirt and moisture, the pushbutton is covered by a foil and sealed. Upon actuating the pushbutton, a ball is moved which acts on a contact maker of a switch which is arranged adjacent to the pushbutton. This known actuator comprises several components which must be manufactured separately and assembled with one another. Despite the elastic cover, dirt and moisture can enter the hole of the outer skin.




Moreover, in devices of the kind mentioned further decorative elements can be provided before, on and/or within the outer skin of the vehicle which serve for embellishing or provide a visual information content. A typical example for this is a company emblem.




SUMMARY OF THE INVENTION




In a device of the latter kind (DE 197 22 503 A1) the decorative element is comprised of a company emblem which is supported rotatably on the outer skin which in its initial position covers a lock body relative to the exterior. The company emblem can be transferred into a release position in which it releases the lock body or another actuator for the vehicle part. In the release position, the company emblem at the same time functions as a grip element in order to completely open the vehicle part, for example, a rear hatch of the vehicle. After actuation of the means, it was necessary to return the company emblem into its initial position. This is cumbersome.




It is known to arrange push buttons for interior gauges of motor vehicles under an elastic plastic skin (DE 42 13 084 A1) and to actuate the switches through the skin. The elastic skin serves as a cover of the steering wheel or an arm rest in the vehicle interior. Such a plastic skin cannot be used for the external actuation of doors or flaps of a vehicle. The external actuator of a door must be able to withstand impacts and must be weathering resistant.




It is moreover known to employ for actuation of switches in an arm rest (WO 97/11473) pressure-responsive resistors which are connected to a control module. The pressure-responsive resistors are arranged on the surface of a foam material laver and the foam material layer is covered by a flexible skin which may have a soft outer layer. Upon pressure actuation on the flexible skin, the foam material layer is compressed and this results in a thickness change of the soft cover positioned above the pressure-responsive resistors. Such soft inner covers of the vehicles are not suitable for external actuators of doors.




It is finally also known in the case of inner covers of vehicles (GB 2 161 122 A) to employ membrane switches underneath an elastic foam material layer, wherein the arrangement locations of the switch, for the purpose of visual and touch recognition, are recessed at some locations. The actuation pressure results in a deformation of the recessed locations of the foam material layer which then act on the membrane switch. Such foamed material layers have also been used for rocker actuators or membrane switches (U.S. Pat. No. 5,448,028), wherein projecting areas in the arm rest indicated the position of the switch. This foam material layer was covered by a flexible skin. The pressure actuation resulted in the compression of the laver above the membrane switch or the rocker with regard to its layer thickness which resulted in pressure being exerted onto the switching elements underneath. Such foam material layers which are compressible with regard to their laver thickness are not suitable for the external actuation of doors.




Cushions of elastic material, whose exterior however must be covered by a metallic coating, have been used on grips or buttons positioned on the exterior side of doors (FR 2 217 784 A). In the elastic cushions a switch with a contact maker was integrated. The contact maker was supported on a bracket arranged before the cover. The car body of the door in this area was provided with a depression in order to provide space for the hand. The hand compressed the elastic cushion from behind, i.e., from the interior of the depression. Accordingly, the cushion together with the switch integrated therein was pressed against the bracket underneath the cover. This door actuators are comprised of numerous components. This known door actuators form disturbing components projecting from the car body which can easily soil and are difficult to clean.




The invention has the object to develop a reliable device of the kind mention above which is embodied inexpensively and is easy to manipulate.




The invention has recognized that either the outer skin of the vehicle or a decorative element seated on the outer skin of the vehicle can take over the further novel functions of being the actuator for the switch. According to a first embodiment, a portion of the outer skin itself is used as an actuator for the switch. For this purpose, it is sufficient to make a certain location at the outer skin elastically deformable by pressure loading. This can be realized by a suitable material selection, sizzling or shaping of the outer skin at this location. The outer skin remains smooth at this location relative to the exterior, requires no holes and no inserted parts. It is sufficient to arrange the contact maker of the switch either directly or indirectly within the yielding path of the car body portion. Since holes are no longer required in the outer skin, there are no sealing problems and there is not risk of soiling.




In an analog way, according to another embodiment, a portion of the decorative element itself is embodied to be elastically deformable and fulfills thus the function of an actuator for a switch whose contact maker is again arranged directly or indirectly in the yielding path of the decorative element portion. In this connection, according to

FIG. 4

, it is beneficial to use the configuration of the decorative element in the form os stays in accordance with the decorative function or the visual information function. The decorative element is in fact divided by stays with intermediately positioned penetrations. The invention has recognized that the stays favor the elastic yielding in a certain portion of the decorative element such that this area is particularly suitable in order to serve as an actuator of the switch. This means that a number of components are no longer needed as they were otherwise required for an actuator provided underneath the decorative element. Moreover, the decorative element must not change at all its initial position in order to trigger the actuator. It is sufficient to press down on the corresponding yielding location of the decorative element in order to obtain the desired switch actuation.











BRIEF DESCRIPTION OF THE DRAWINGS




Further features and advantages of the invention result from the dependent claims, the following description, and the drawings. In the drawings, the invention is illustrated in several embodiments. It is shown in:





FIG. 1

a longitudinal section of a portion of the outer skin of a vehicle with the actuating location according to the invention, shown in the rest position;





FIG. 2

the device illustrated in

FIG. 1

in the situation of pressure actuation;





FIG. 3

a first alternative embodiment of the invention, i.e., a longitudinal slot through a portion of a rear hatch of a motor vehicle, shown in the rest position;





FIG. 4

the device illustrated in

FIG. 2

in the actuating situation;





FIG. 5

a further embodiment of the device according to the invention, where the actuatable deformation location is integrated into a company emblem which is seated on the outer skin of a rear hatch of the vehicle, shown in a rest position;





FIG. 6

a detail of the device shown in

FIG. 5

during its pressure actuation;





FIG. 7

the spaced position of the company emblem resulting from the pressure actuation of FIG.


6


and now serving as a hand grip for completely opening the flap; and




FIGS.


8


+


9


two modified embodiments of the device illustrated in

FIGS. 5 through 7

when the company emblem is in a spaced position.











DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS





FIG. 1

shows in a longitudinal section a portion of a rear hatch


10


of the motor vehicle which is secured by a lock, not shown in detail, in the closed position. In order to facilitate opening of the lock, a drive, not illustrated in detail, is provided, for example, an electric motor. For switching on or off this drive, a switch


12


is provided which is connected by lines


35


with the drive. In the usually present closed position of

FIG. 1

the drive is inactive. The switch


12


is fastened on a support


36


which is integrated into the structure of the hatch


10


in this configuration. A contact maker


13


of the switch


12


is arranged on the backside


41


of the outer skin


40


and should be, if possible, in contact with the backside


41


. The contact maker


13


in the present case is comprised of a pin which is longitudinally movable in the direction of arrow


16


and, according to its movement, can perform different switching functions within the switch


12


. When the pin


13


is pushed in, the contacts within the switch


12


are closed, and a corresponding switch-on signal is transmitted via lines


35


to the drive.




Several switches


12


can be provided at this location or in the neighboring area which are correlated with further functions in the vehicle, for example, for closing the closure when closing the rear hatch. Such switches


12


can also activate additional functions on the vehicle, such as closing or opening of the doors, the windows and the sliding roof of a vehicle. These different functions can alternatively also be triggered by different magnitudes of the pushing-in movement


16


of the contact maker


13


. Between the contact maker


13


of the switch


12


and the backside


41


of the skin, it is also possible to arrange transmission members for the switch actuation so that the switch


12


itself could be fastened at a more beneficial location relative to the outer skin


40


which location is moved farther away.




The location


43


of the outer skin


40


which is substantially aligned with the contact maker


13


is elastically deformable relative to the adjoining neighboring area


42


when pressure is exerted there according to the force arrow


20


of FIG.


2


. For short, this location


43


will therefore be referred to in the following as “deformation location” of the outer skin


40


. The actuation situation of the deformation location is illustrated in FIG.


2


and the deformation resulting therefrom is indicated at


43


′. The yielding path, indicated in

FIG. 2

at


29


, results in which the contact maker


13


is arranged directly, as mentioned before. The drive is then activated in the described way. The rear hatch


10


can be transferred in the direction of movement arrow


11


of

FIG. 2

into the upwardly folded position, not illustrated in detail.




The deformation location


43


is suitably embodied such that upon pressure actuation


20


a defined yielding action is realized. This can be realized by a corresponding shaping of the location


43


and/or by a reduction of the wall thickness


45


of this outer skin


40


. Also, weakening of this deformation location


43


by cutouts in the wall of the outer skin


40


would be conceivable. The center of the deformation location


43


, which is especially effective for the exertion of the pressure


20


, should be marked in a special way at the exposed side


46


of the outer skin


40


. The drive, in the actuation situation of the deformation location


23


′, can be used for a complete opening of the rear hatch


10


without this requiring an auxiliary manual handling. This should also apply in the case of the other embodiments.




The embodiment according to

FIGS. 3 and 4

shows a modification of the lock wherein for identifying corresponding components the same reference numerals as in the preceding embodiment of

FIGS. 1 and 2

are used. In this connection, the previous description applies. It is sufficient to discuss the differences.




The actuator for the switch in the present case is a company emblem


25


with a circular contour


24


which has an elastically deformable portion. The company emblem


25


has a logo which is comprised of several stays


23


,


27


. The stays


23


,


27


fulfill a certain decorative function and can also provide a visual information content and can be comprised of letters and/or an image. Between the stays there are penetrations. In the present embodiment there is even a separating cut


26


between two stays


23


,


27


which make one stay


23


flexible. The stay


23


is fast at one end in the circumferential area


24


, but is flexible at its oppositely positioned free end


28


. The stay


23


fulfills the function of a flexible bar. It is deformed in the direction of arrow


20


″ of

FIG. 4

relative to the neighboring stay


27


, which is in itself rigid, toward the switch


12


and reaches the position


23


′. This is illustrated in

FIG. 4

by the deformation travel


29


. The company emblem is integrated into a neighboring area


22


of the car body.




As can be seen in

FIG. 4

, the company emblem


25


belongs to a modular unit


30


which in itself can be completely pre-assembled and comprises the following components. There is first a mounting plate


17


on whose backside


18


the already mentioned microswitch


12


with its housing is fastened. A guide


14


on the switch housing penetrates a penetration


19


provided within the mounting plate


17


so that the contact-providing pin


13


is positioned at the inner side


31


of the mounting plate


17


. In front of the contact pin


13


a continuous elastic membrane


33


can be arranged, which is illustrated in

FIGS. 3 and 4

only by a dash-dotted line and which is a component of the modular unit


30


and extends over the entire inner side


31


of the plate in a sealing way. The company emblem


25


, together with the membrane


33


and a circumferential seal


34


, is fixedly connected to the mounting plate


17


, for example, by screws. Of course, these fastening screws do not impair the flexibility of the afore described yielding location


23


. This modular unit


30


is mounted in the aforementioned neighboring area


22


of the outer skin in a cutout


32


, illustrated in FIG.


4


.




When the force exertion


20


of

FIG. 4

is finished, the elasticity within the company emblem


25


ensures that the car body location returns from its actuating position


23


′ again into its initial position of FIG.


3


. This restoring movement can be supported, if needed, also by additional elastic means such as leaf spring. Normally, this is not required, in particular, because the membrane


33


has a certain restoring elasticity. The membrane


33


has in fact the tendency to return into the curved position illustrated in

FIG. 3

which is its stable state.




It is understood that, instead of a company emblem


25


, other decorative elements on the outer skin of the vehicle can take over the function of the inventive actuator for a microswitch. For example, it is possible to use decorative parts of a vehicle for this purpose. However, suitable would be also designation parts on the vehicle which are provided anyway, for example, the model designation of the vehicle.




In the third embodiment of

FIGS. 5 through 7

, a modular unit


21


comprised of an attachment


50


and an insert


37


is provided, wherein a company emblem


51


is integrated also in the attachment


50


. This modular unit


21


is pre-manufactured and mounted in the neighboring area


22


of the car body. In contrast to the preceding embodiment of

FIGS. 3 and 4

, the company emblem


51


integrated into the attachment


50


is movable by the same motor


15


which also serves for actuating the lock which is not illustrated in detail.

FIG. 7

shows the spaced position


50


.


2


where the attachment


50


has an angle α of approximately 45° relative to the contact position


50


.


1


in FIG.


5


.




The insert


37


on the other hand remains stationary. It forms the inner layer of this modular unit


21


, is comprised of elastomeric material, and is seated in a cutout


32


of the outer skin


40


. this inner layer


37


forms an elastic seal and has a central dome


38


in front of the contact maker


13


of a switch


12


which is seated on the support


36


. In a paced position according to

FIG. 7

, a closing cylinder


48


, which in an emergency situation allows for a key actuation of the rear hatch lock, is accessible through an opening


39


in the inner layer


37


. the closing cylinder


48


is mounted on the support


36


. On the support


36


two levers


47


are connected at


49


. The levers


47


support the attachment


50


.




As can be taken best from

FIG. 7

, the attachment


50


itself is of a multi-layer configuration comprised of the outer company emblem


51


, a membrane


52


arranged at the backside thereof and having elasticity of extension, and a shape-stiff grip plate


53


which is comprised of metal. The company emblem


51


is comprised of a relatively shape-stable material, i.e., plastic, but has penetrations


54


which provide in the central area of this outer layer


51


a sufficient elasticity of flexure. The company emblem


51


is three-dimensional and has penetrations


54


in the relief between the lettering and the image. The penetrations


54


are closed at the backside by the expandable membrane


52


and are thus sealed. The grip plate


53


positioned underneath is seated on the free ends of the levers


47


and has a hole


55


at a defined location. The three layers


51


,


52


,


53


of the attachment


50


are fixedly connected to one another at their periphery


24


. At the central area of the attachment


50


a sufficient spacing is provided between the grip plate


53


and the flexible layers


51


,


52


positioned above.




Normally, the contact position


50


.


1


, which is indicated in

FIG. 5

by an auxiliary line


50


.


1


, is present where the modular unit


21


is positioned closely at the inner layer


37


within the cutout


32


of the outer skin


40


. In this case, the central dome


38


of the elastic inner layer


37


projects through the hole


55


of the grip plate and, as illustrated in

FIG. 5

, is aligned with a yielding location


23


of the company emblem


51


. The yielding action is recognizable for the pressure actuation


20


illustrated in FIG.


6


. In the company emblem


51


the yielding location


23


is transferred into the pushed-in position


23


′ illustrated therein where the dome of the elastic inner layer


37


positioned behind has been pushed into the area of the grip plate hole


55


and thus has suffered a flattening


38


′. Accordingly, the contact maker


13


is pushed in and the switch


12


actuated. The grip plate


53


limits the pressure actuation


20


of the actuated deformation location


23


′ according to FIG.


4


.




The actuation of the switch


12


activates the drive


15


by means of an electronic control, not illustrated in detail, which drive, as mentioned already above, first transfers the lock of the rear hatch


10


into a ready position for opening. The same motor drive


15


, expediently after a short delay, is also used for movement of the modular unit


50


. This movement is realized via the levers


47


which are pivoted outwardly. This results in the already aforementioned spaced position of

FIG. 7

which is indicated therein by the auxiliary line


50


.


2


. Now the grip plate


53


can be engaged from behind by a human hand


5


.


6


in order to transfer the rear hatch


10


in the direction of movement arrow


11


of

FIG. 7

into the completely open position. For this purpose, the opening force which is illustrated by the force arrow


57


is provided.




From its spaced position


50


.


2


the modular unit


50


is returned manually or by a motor drive into, its contact position


50


.


1


of FIG.


1


. This can also be performed automatically upon closing of the rear hatch.




The device according to

FIG. 3

to


5


could also be integrated as an immobile attachment


50


or as an insert into the outer skin


40


when the function of a hand grip according to

FIG. 5

is not to be utilized. In this case, the grip plate


53


and the lever


47


can be eliminated. however, the outer layer


51


as the company emblem remains in place behind which sealing layers


52


and/or


37


are positioned and which acts through the actuating pressure


20


according to

FIG. 4

in the already described way on the contact member


13


of the switch


12


.




Should the electrical devices of the vehicle be defective and the switch


12


and the drive


15


therefore not be functioning, the rear hatch


10


can still be opened. The attachment


50


has, as illustrated in

FIGS. 5 and 7

, in the lower area a rearward cutout


58


which is accessible for the fingertips of a human hand. By a manual pulling action, the levers


47


can then be decoupled from a locking position coupled with the motor


15


and make possible a manual pivoting of the modular unit into the spaced position illustrated in FIG.


7


. As already mentioned, the end face of the closing cylinder


48


, which is normally positioned below the modular unit


50


, is then accessible through the opening


39


of the inner layer


37


and makes possible the opening of the rear hatch, as already mentioned, by means of an emergency key.




In

FIG. 8

a modification of the device of

FIGS. 5 through 7

is illustrated. It is sufficient to only discuss the differences while in other respects the description provided above applies. In this case the levers


47


are connected fixedly to a bearing shaft


59


for common rotation. The shaft


59


is driven by a transmission


16


which is arranged downstream of the motor


15


.




The emergency situation described in the preceding embodiment can be applied also in this modification of FIG.


8


. In this case, between the bearing shaft


59


and the transmission


60


a locking coupling is provided which can be, for example, a magnetic coupling which acts by means of permanent magnets. By exerting a sufficiently great opening force, the magnetic coupling is decoupled and the levers


47


reach a “freewheeling” position.




In the embodiment of

FIG. 9

, a drive


61


, modified in comparison to

FIG. 8

, is illustrated which is comprised of a motor, in particular, an electric motor and a transmission. Here, the output member of the transmission is a tooth rack


62


which engages a gear wheel


63


. The gear wheel


63


is fixedly connected with the levers


47


and pivotable together with them about their connecting location


49


.





FIG. 9

shows in solid lines the inserted position


62


of the tooth rack. Its retracted position


62


′ is illustrated in dash-dotted lines. It is present when the attachment


50


is positioned in the contact position illustrated in the second to last embodiment of FIG.


5


. In this case, in an emergency situation it is possible to manually move away the attachment


50


from the outer skin


40


. For this purpose, it is sufficient to employ a double tooth rack or to employ again the afore described magnet coupling between the movable transmission parts.



Claims
  • 1. A device for actuating an opening mechanism and/or a closing mechanism of lockable movable parts on vehicles, wherein, when the lockable movable parts are in an open position, the lockable movable parts allow access to at least certain areas within an interior of the vehicle, the device comprisinga manual actuator which in an activated position acts on at least one contact maker of at least one switch, wherein the actuated switch switches on a drive for opening or closing the movable vehicle part, an outer skin mounted on the vehicle or on the movable vehicle part, a decorative element mounted in front of, on and/or in the outer skin, the decorative element having decorative character and/or an information content, wherein the decorative element is divided according to the decorative character and/or the information content into stays and penetrations positioned between the stays, and wherein at least one portion of the stays is elastically yielding and forms the actuator for the switch.
  • 2. The device according to claim 1, wherein the contact maker of the switch is arranged either directly or indirectly via transmission members in a yielding path of the decorative element portion.
  • 3. The device according to claim 1, wherein the decorative element has a contact-providing stay which is flexible and acts in a contact-providing way on the switch.
  • 4. The device according to claim 3, wherein at least one separating cut is arranged between neighboring stays of the decorative element, and wherein the separating cut increases the elasticity of flexure of the stay or stays acting as the switch actuator.
  • 5. The device according to claim 1, wherein the decorative element is comprised of an insert or an attachment which is movable relative to the outer skin between at least two positions, whereinthe attachment, after pressure actuation of the yielding stay, is movable from a substantially flush or parallel contact position relative to the surrounding area of the outer skin into a projecting spaced position, and wherein the attachment, which projects when in the spaced position, forms a hand grip for manually fully opening or closing the movable vehicle part.
  • 6. The device according to claim 5, wherein the insert or attachment is foldable relative to the neighboring area of the outer skin and is positioned at an angled position when in the spaced position.
  • 7. The device according to claim 5, wherein the spaced position of the decorative element is a ready position for opening from where a completely opened position of the vehicle part is realized by a further manual movement.
  • 8. The device according to claim 5, wherein the attachment, when in a projecting position, is movable after a renewed actuation from the spaced position into the contact position.
  • 9. The device according to claim 5, wherein a reversal of movement of the attachment between the contact position and the spaced position is effected by a drive, wherein the drive also serves for opening or closing the movable vehicle part or a corresponding lock.
  • 10. The device according to claim 9, wherein a lever supporting the attachment or insert is fixedly connected to a bearing shaft for common rotation, and wherein the bearing shaft is movable by a motor or transmission of the drive.
  • 11. The device according to claim 9, wherein the attachment or insert has an axis, and wherein the attachment or insert is fixedly connected in an area of the axis to a gear wheel for common rotation, and whereinthe gear wheel engages a tooth rack and the tooth rack is longitudinally movable by the motor or transmission arranged downstream of the motor of the drive.
  • 12. The device according to claim 5, wherein a locking coupling is connected within members of the drive extending to the attachment or insert, whereinthe locking coupling in a normal situation is engaged and makes possible a motor-driven movement of the attachment or insert, and wherein the locking coupling in an emergency situation is automatically releasable in order to transfer the attachment or insert manually from the contact position into the spaced position.
  • 13. The device according to claim 12, wherein the locking coupling act magnetically.
  • 14. The device according to claim 5, wherein the attachment or insert of the outer skin has several locations which are effective for actuation of one or more contact makers of one or more switches, and wherein the several actuating locations perform different functions on the vehicle.
  • 15. The device according to claim 14, wherein one actuation location serves for opening and another actuation location serves for closing the movable vehicle part and/or wherein the actuation locations serve for performing a movement of the attachment or insert between the contact position and the spaced position.
  • 16. The device according to claim 5, wherein the switch responds by means of the contact maker to different magnitudes of deformation of the actuation location, and whereindifferent deformations of the actuation location trigger different functions in the vehicle.
  • 17. The device according to claim 16, wherein the attachment or insert forms a modular unit mountable together on the outer skin of the vehicle.
  • 18. The device according to claim 5, wherein a stationary insert is arranged under the movable attachment in the outer skin, and whereinthe insert and attachment comprises at least over areas thereof several layers which, upon pressure actuation, are commonly deformable but separate with respect to their layers.
  • 19. The device according to claim 18, wherein an inner layer of the insert is comprised of elastomeric material and sealingly covers a cutout in the outer skin of the vehicle, and whereinthe contact maker and the switch and further functional parts of the vehicle are arranged in an area of the cutout.
  • 20. The device according to claim 18, wherein, on a backside of the outer layer of the attachment provided with stays and penetrations, a membrane having elasticity of extension is arranged which closes empty spaces of the penetrations.
  • 21. The device according to claim 5, wherein a layer of the insert or attachment is comprised of a shape-stiff material, and wherein the layer form s a plate which is rigid, and whereinthe plate has a hole through which, in the actuation situation, the pressure actuation force is transmitted onto a deformable area of a further layer arranged underneath.
Priority Claims (2)
Number Date Country Kind
199 22 657 May 1999 DE
199 61 246 Dec 1999 DE
PCT Information
Filing Document Filing Date Country Kind
PCT/EP00/03983 WO 00
Publishing Document Publishing Date Country Kind
WO00/70633 11/23/2000 WO A
US Referenced Citations (6)
Number Name Date Kind
3654415 Hawkins et al. Apr 1972 A
4713509 Chebowski Dec 1987 A
5448028 Filion et al. Sep 1995 A
5489754 Dirmeyer et al. Feb 1996 A
5498844 Chan Mar 1996 A
5784891 Lee Jul 1998 A
Foreign Referenced Citations (3)
Number Date Country
2217784 Sep 1974 FR
2161122 Jan 1986 GB
9711473 Mar 1997 WO