Method of clamping a workpiece

Information

  • Patent Grant
  • 6241231
  • Patent Number
    6,241,231
  • Date Filed
    Friday, March 17, 2000
    24 years ago
  • Date Issued
    Tuesday, June 5, 2001
    23 years ago
Abstract
A clamping device for frictional clamping of a workpiece which includes a clamp element adapted to frictionally clamp a workpiece and a mechanism for moving the clamp element which includes a shape memory alloy adapted to move the clamp element when the shape memory alloy is heated. The shape memory alloy moves the clamp element into a clamped state and/or unclamped state upon heating the shape memory alloy. The clamped element is preferably a super elastic alloy which is naturally oriented in a clamped position for a positive clamp and in an unclamped position for a non-positive clamp.
Description




The invention relates generally to a device for clamping workpieces and more particularly to a novel and improved clamping device which incorporates a shape memory alloy to clamp and/or unclamp a workpiece.




INCORPORATION BY REFERENCE




U.S. Pat. No. 5,197,720 illustrates the use of a super elastic alloy used in a non-positive clamping device and is incorporated herein by reference.




BACKGROUND OF THE INVENTION




Clamps for releasably holding materials during a manufacture process or the releasable locking of tooling such as dies, fixtures or molding plates are known in the art. Such self-locking clamping devices are illustrated in U.S. Pat. Nos. 4,721,293, RE 32,704 and 5,197,720. In U.S. Pat. Nos. 4,721,293 and RE 32,704, non-positive locking clamping devices are designed to use a fluid such as air or water to move a piston to clamp a workpiece. In U.S. Pat. No. 5,197,720, a non-positive clamping device is shown which incorporates the use of a super elastic alloy. The '720 patent incorrectly uses the term “shape memory alloy” to identify the super elastic alloy. As discussed below, shape memory alloys are a special class of alloys that have shape memory characteristics when heated, whereas super elastic alloys exhibit shape memory characteristics when physical stresses are applied to the alloys. The super elastic alloy in the '720 patent is designed to be mechanically moved by the use of a fluid to thereby lock a workpiece in position. When the workpiece is to be released, the fluid pressure is reduced thereby allowing the super elastic alloy to revert to its original shape and position thereby unclamping the workpiece.




Non-positive clamping tools can provide adequate clamping when properly operated. However, if a failure occurs which would result in a loss of fluid pressure, the clamping forces dissipate thereby allowing the workpiece to be inadvertently released from the clamp. Furthermore, the non-positive clamping device is typically complex in design and requires sophisticated pumps, seals and overall design to operate. The inherent complexity of this design subjects the design to an increased possibility of failure, i.e. pump, valve fitting or line failures. Positive clamping devices overcome the problems associated with non-positive clamping devices; however, such positive clamping devices have typically required complex designs resulting in a clamp that is difficult to repair when it fails.




In view of the prior art of clamping devices, there is a demand for a clamping device which is easy to manufacture, simple in design, reliable in operation and can clamp and unclamp a wide variety of workpieces.




SUMMARY OF THE INVENTION




In accordance with the present invention, there is provided a novel clamping device for the clamping of a workpiece in position. Preferably, the clamp device is designed for positive clamping; however, the clamp can be alternatively designed for non-positive clamping applications. The clamping device includes a clamping element such as a clamping surface, clamping pin, clamping lock, clamping clip, etc. which is designed to secure and unsecure a workpiece to and from a clamp surface. The clamping element is preferably made of a material strong enough to secure a workpiece in position for a particular type of operation. In addition, the clamping element preferably has flexible properties which allow the clamping element to be moved between a clamp and unclamped position. The clamping device also preferably includes a mechanism for moving the clamping element into a clamped state or unclamped state to provide for positive clamping or non-positive clamping, respectively. As can be appreciated, the clamping device has a wide variety of applications due to the positive nature or non-positive nature of clamping and further provides a mechanism for easily clamping or unclamping of a workpiece.




In accordance with another aspect of the present invention, the clamping element includes a super elastic alloy. Super elastic alloys are alloys which exhibit super elastic/pseudo elastic shape recovery characteristics. These alloys are characterized by their ability to be transformed from an martensitic crystal structure to a stress induced martensitic structure and return elastically to the austenitic shape when the stress is removed. These alternating crystalline structures provide the alloy with its super elastic properties. Such alloys may include an alloy comprising primarily of In—Ti, Fe—Mn, Ni—Ti, Ag—Cd, Au—Cd, Au—Cu, Cu—Al—Ni, Cu—Au—Zn, Cu—Zn, Cu—Zn—Al, Cu—Zn—Sn, Cu—Zn—Xe, Fe, Be, Fe


3


Pt, Ni—Ti—V, Fe—Ni—Ti—Co, Cu—Sn and Ni—Ti—Cu. These alloy systems may include small amounts of other metals which improve the super elastic characteristics of the alloy. These alloys are especially suitable for use in clamping devices in that their capacity to elastically recover almost completely to their initial configuration once stress has been removed on the alloy. In accordance with yet another aspect of the present invention, the super elastic alloy preferably is a separate component of the clamping device and is shaped to provide a force on the clamped element to force the clamped element into a clamped state for positive clamping. Alternatively, or in addition to, the clamping element may be made up of or include a super elastic alloy which is shaped for positive clamping of the workpiece. By designing the clamping element to be or include a super elastic alloy, the clamping element will position itself into a clamped state for positive clamping. An external force is used to move the clamping element into an unclamped state. Once the external force is reduced or removed, the clamping element will elastically move into its original clamped position.




In accordance with still another aspect of the present invention, the clamping device includes a super elastic alloy which is shaped to provide a force on the clamped element to force the clamped element into an unclamped state for non-positive clamping. Alternatively, or in addition to, the clamping element may be made up of or include a super elastic alloy which is shaped for non-positive clamping of a workpiece. By designing the clamping element to be or include a super elastic alloy, the clamping element will position itself in an unclamped state for non-positive clamping. An external force is used to move the clamping element into a clamped state. Once the external force is reduced or removed, the clamping element will elastically move into its original unclamped position.




In accordance with still yet another aspect of the present invention, the mechanism for moving the clamping element into an unclamped state includes the use of a fluid such as gas or liquid to apply a force to the clamping element to cause the clamping element to move into an unclamped state. Preferably, the fluid is at least partially encapsulated in a super elastic alloy. The pressurization of the fluid causes, the super elastic alloy to move thereby causing the clamping element to move into an unclamped state. When the pressure of the fluid is reduced, the force on the clamping element is also reduced thereby allowing the clamping element to return to the clamped state. The clamping element may include and/or be the super elastic alloy or be a separate component. Preferably, the clamping element is or includes a super elastic alloy that is shaped in a natural unclamped position.




In accordance with another aspect of the present invention, the mechanism for moving the clamping element into a clamped state includes the use of a fluid such as a gas or liquid to apply pressure to the clamping element and to cause the clamping element to move into its clamped state. Preferably, the fluid is a compressible fluid sealed in the body of the clamping device. The fluid is pressurized to constantly apply a force to the clamping element to force the clamping element into a clamped state. The fluid is compressible so as to allow the clamped element to be moved out of its clamped state when the mechanism for moving the clamping element out of its clamped state has been activated. The clamping element may include and/or be the super elastic alloy or be a separate component. Preferably, the clamping element is or includes a super elastic alloy that is shaped in a natural clamped position. Once the forces acting to move the clamping element to orient the clamping element in the unclamped state have been removed, the pressurized fluid in the fluid chamber forces the repositioning of the clamping element into its clamped state. Preferably, the fluid is a gas such as air, nitrogen or an inert gas.




In accordance with still another aspect of the present invention, the mechanism for moving the clamping element into a clamped or an unclamped orientation includes the use of a shape memory alloy. Shape memory alloys are alloys which, after being deformed, can recover their original shape when heated. Due to the unique property of these alloys, such alloys upon being heated expand in size and upon being cooled return to essentially the original shape and size. The alloy composition of the shape memory alloy is selected to have a hardness and strength which is sufficient to apply a force when expanded by heat to the clamping element to move the clamping element and clamp a workpiece in position. Such alloys may include an alloy comprising primarily of Ti—Ni, Ti—Ni—Fe, Cu—Zn—Al, and Cu—Al—Ni. These alloy systems may include small amounts of other metals, preferably non-ferrous, which improve the shape memory characteristics of the alloys. One type of shape memory alloy which is particularly applicable to the present invention is a nickel-titanium alloy. Such an alloy exhibits the hardness and strength which is comparable to steel materials, has excellent corrosion resistant properties, excellent strength and has a very high reversible deformation property. In addition, a nickel-titanium alloy has a transformation temperature which can be adjusted between the marstenstitic and austhentic microstructure in a range from−100° to 100° C. by using an appropriate alloy composition. The shape memory alloy is preferably heated by an electric heating element positioned closely adjacent to the shape memory alloy. Upon applying a current to the electrodes, the heating element increases in temperature thereby causing the shape memory alloy to expand. Once the current through the electrodes is terminated, the heat in the heating element dissipates and the shape memory alloy returns to its original size and shape. The heating of the shape memory alloy can alternatively or in combination be heated by electrical resistance heating, fluid heat exchange heating, chemical reaction heating, convection heating and/or radiation heating. The heating of the shape memory alloy causes the clamped element to move and the subsequent cooling of the shape memory alloy allows the clamped element to return to its original position.




In accordance with still yet another aspect of the present invention, the clamping device incorporates a clamping element made up of or including a super elastic alloy which is designed to move into a clamped and/or an unclamped state, and a shape memory alloy to move the clamping element. For a non-positive clamp arrangement, the clamping device clamps a workpiece when the shape memory alloy is heated by forcing the clamping element into the clamped position. The subsequent cooling of the shape memory alloy results in the contracting of the shape memory alloy and allows the clamping element to move into the unclamped position. For a non-positive clamp arrangement, the clamping element preferably is a super elastic alloy having a natural shape corresponding to the unclamped position. For a positive clamp arrangement, the clamping device unclamps a workpiece when the shape memory alloy is heated by forcing the clamping element into the unclamped position. The subsequent cooling of the shape memory alloy results in the contracting of the shape memory alloy and alloys the clamping element to move into the clamped position. For a positive clamp arrangement, the clamping element preferably is a super elastic alloy having a natural shape corresponding to the clamped position.




It is the object of the present invention to develop a clamping device which can clamp a wide variety of workpieces.




It is another object of the present invention to provide a clamping device which is cost effective and easy to manufacture and which device has a durable, reliable and simple design to ensure the proper clamping of a workpiece.




It is still another object of the present invention to include a super elastic alloy in a clamping device which super elastic alloy is designed to clamp and/or unclamp a workpiece in place.




It is still yet another object of the present invention to provide a shape memory alloy in a clamping device, which alloy upon heating expands in size, wherein the shape memory alloy moves into a clamped and/or unclamped position when the shape memory alloy is heated.




It is yet another object of the present invention to provide a clamping device which includes a shape memory alloy and a super elastic alloy wherein the shape memory alloy applies a force upon heating to the super elastic alloy to cause the super elastic alloy to move into a clamped and/or unclamped position.




It is another object of the present invention to provide a clamping device which includes a shape memory alloy wherein the shape memory alloy clamps and/or unclamps a workpiece upon being heated.




These and other objects and advantages will become apparent to those skilled in the art upon reading the following description taking together with the preferred embodiments disclosed in the accompanied drawings.











BRIEF DESCRIPTION OF THE DRAWINGS




Reference may now be made to the drawings, which illustrate various preferred embodiments that the invention may take in physical form and in certain parts and arrangements of parts wherein:





FIG. 1

is a plan view of a prior art non-positive clamping device;





FIG. 2

is a plan view of a positive clamping device in accordance with the present invention;





FIG. 3

is a cross-sectional view taken along line


3


:


3


of

FIG. 2

;





FIG. 4

is a plan view of the clamping device as in

FIG. 2

which illustrates the clamping device in an unclamped position;





FIG. 5

is a pictorial view of two components of the clamp illustrated in

FIG. 2

;





FIG. 6

is a top view of a second embodiment of a clamp in accordance with the present invention;





FIG. 7

is a side view of the clamp as illustrated in

FIG. 6

;





FIG. 8

is a cross-sectional view taken along line


8


:


8


in

FIG. 6

which illustrates the clamp in a clamped position;





FIG. 9

is a similar view as shown in

FIG. 8

but which illustrates the clamping device in an unclamped position;





FIG. 10

is a pictorial view of several elements of the clamp as shown in

FIG. 6

;





FIG. 11

is a top view of another embodiment of a clamp in accordance with the present invention;





FIG. 12

is a side view of the clamp illustrated in

FIG. 11

;





FIG. 13

is a cross-sectional view taken along line


13


:


13


in

FIG. 11

which illustrates the clamp in a clamped position;





FIG. 14

is a cross-sectional view taken along line


14


:


14


of

FIG. 11

which illustrates the clamp in a clamped position;





FIG. 15

is a similar view as shown in

FIG. 14

but which illustrates the clamp in an unclamped position;





FIG. 16

is a pictorial view of several elements of the clamp as illustrated in

FIG. 11

;





FIG. 17

is a view similar to

FIG. 13

but illustrates still another embodiment of the present invention;





FIG. 18

is a pictorial view of two elements of the clamp illustrated in

FIG. 17

;





FIG. 19

is a top view of another embodiment of the clamp in accordance with the present invention;





FIG. 20

is a side view of the clamp illustrated in

FIG. 19

;





FIG. 21

is a cross-sectional view taken along line


21


:


21


of

FIG. 20

;





FIG. 22

is a cross-sectional view taken along line


22


:


22


of

FIG. 19

which illustrates the clamp in a clamped position;





FIG. 23

is a cross-sectional view taken along line


23


:


23


of

FIG. 20

;





FIG. 24

is a similar view as shown in

FIG. 22

but which illustrates the clamp in an unclamped position;





FIG. 25

is a pictorial view of several of the components of the clamp as illustrated in

FIG. 19

;





FIG. 26

is a top view of another clamp in accordance with the present invention;





FIG. 27

is a side view of the clamp illustrated in

FIG. 26

;





FIG. 28

is a cross-sectional view taken along line


28


:


28


of

FIG. 26

which illustrates the clamp in a clamped position; and,





FIG. 29

is a cross-sectional view taken along line


29


:


29


of FIG.


28


.











DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS




Referring now to the drawings wherein the showings are for the purpose of illustrating preferred embodiments of the invention only and not for the purpose of limiting the same, an improved clamping device is proved which incorporates the use of a shape memory alloy to clamp and/or unclamp a workpiece to significantly improve the reliability of clamping in both a positive clamping or non-positive clamping configuration. Shape memory alloys are known for their unique quality for retaining their original shape upon being heated below their critical temperature and subsequently cooled. Another unique feature of shape memory alloys is that upon heating, the alloy increases in volume and upon subsequent cooling, returns to its original volume and shape. These unique qualities of shape memory alloys can be advantageously used to clamp and/or unclamp a workpiece. One type of shape memory alloy which is of particular interest for use in a clamp is a nickel titanium alloy. Such an alloy is very durable and strong and is ideal for use in a clamp. One specific type of shape memory alloy is a titanium-nickel alloy manufactured by Raychem and identified as TINEL® alloy K.




In addition to the incorporation of a shape memory alloy in a clamp device, the use of a super elastic alloy in combination with a shape memory alloy has been found to form both positive and non-positive clamps which were, until now, unavailable. Super elastic alloys are a unique type of alloy which retain their original shape qualities even after being forced to move into a non-natural shape. For instance, a super elastic alloy having a naturally occurring planar shape that is forced into a slightly arcuate shape, will return to its original planar shape once the force is removed from the super elastic alloy. As can be appreciated, this unique physical property of super elastic alloys is highly beneficial to various types of clamping devices. One particular type of super elastic alloy which is preferably used in clamping devices is a nickel-titanium alloy manufactured by NDC and identified as Nitanol Se 10. Nickel titanium alloys are alloys exhibiting excellent durability and high strength properties.




A shape memory alloy or a shape memory alloy and a super elastic alloy can be used in many types and designs of clamps. In one type of clamp arrangement, the clamp is a non-positive clamp which is defined as a clamp which requires the shape memory alloy to be heated so as to clamp a workpiece in position. When the shape memory alloy is not heated, the clamp is in an unclamped position therefore allowing the workpiece to be non-securely inserted into and/or removed from the clamp arrangement. The shape memory alloy can be positioned in the clamp arrangement such as to directly contact the workpiece upon expansion thereby clamping the workpiece in position or the shape memory alloy can cause another piece of the clamp arrangement to engage the workpiece during clamping. As can be appreciated, such a clamp design can be a simple yet effective design to clamp a workpiece. Due to the special nature of the shape memory alloys, the increase in heat of the shape memory alloy causes the shape memory alloy to further expand. Therefore, the clamping force applied to a workpiece is a function of the amount of heat being applied to the shape memory alloy. This additional feature of the shape memory alloy can be incorporated into an automated control mechanism whereby the desired amount of clamping force applied by the shape memory alloy can be selected by supplying a specific amount of heat to the shape memory alloy. Preferably, the heat source to the shape memory alloy is by electric resistance heating a heating element positioned adjacent to the alloy by an electric current. However, other sources of heat to the shape memory alloy can include electric resistance heating, radiation heating, heat from a chemical reaction or by some form of convection heating.




In another type of clamping arrangement, the shape memory alloy can be used in a positive clamping configuration so that when the shape memory alloy is heated, the shape memory alloy causes the workpiece to become unsecured from the clamp. In one such arrangement, a workpiece is held in position by a clamping element which is biased in a clamping position by a spring. The shape memory alloy is positioned relative to the clamping element such that when the shape memory alloy is heated, the shape memory alloy counteracts the force of the spring thereby causing the clamping element to reduce the force being applied to the workpiece thereby allowing the workpiece to be removed from the clamp arrangement. As can be appreciated, a number of clamping arrangements can be used which incorporates a shape memory alloy in a positive and non-positive clamping arrangement.




The clamping arrangements which include both a shape memory alloy and a super elastic alloy further increase the number of different types of clamping arrangements for both positive and non-positive clamps. When a super elastic alloy is incorporated in the clamping arrangement, the super elastic alloy is preferably in the form of the clamping element which is designed to directly contact the workpiece and hold the workpiece in a clamped position. For non-positive clamping arrangements, the natural shape of the super elastic alloy is in the shape of an unclamped position to allow the workpiece to be unsecuredly inserted into and removed from the clamping arrangement. The shape memory alloy is positioned with respect to the super elastic alloy such that when the shape memory alloy is heated, the shape memory alloy directly and/or indirectly applies a force to the super elastic alloy thereby causing the super elastic alloy to deform into a clamped position to secure the workpiece. When the shape memory alloy is cooled, the shape memory alloy returns to its original shape and form thereby removing the deforming forces on the super elastic alloy, which in turn results in the super elastic alloy returning to its natural unclamped position. As can be appreciated, a similar arrangement can be used for a positive clamping arrangement. For a positive clamping arrangement, the super elastic alloy is shaped such that its natural shape or orientation is in the clamped state thereby securing the workpiece securely to the clamp. Therefore, the workpiece can only be removed from the clamp when the shape memory alloy is heated which in turn applies a force directly and/or indirectly on the super elastic alloy which causes the super elastic alloy to deform in shape into the unclamped position thereby allowing the workpiece to be removed from the clamp. As can be appreciated, there are many clamp arrangements which can incorporate a super elastic alloy and a shape memory alloy to form a positive or non-positive clamp arrangement.




Reference will now be made to specific applications for a clamp arrangement which incorporates a shape memory alloy and/or a super elastic alloy in a positive clamp arrangement.

FIG. 1

illustrates a prior art non-positive clamping arrangement. Clamping arrangement


30


clamps a workpiece


40


to the clamp body


48


by using a clamping element


60


. Workpiece


40


is positioned onto clamp body


48


and arranged such that one surface of the workpiece is positioned against clamp base surface


50


and another portion of the workpiece is positioned against clamp side surface


52


. The clamp body also includes a clamp element cavity


54


positioned adjacent to the workpiece. Clamp base


72


of the clamping element is partially inserted into the clamp element cavity


54


. The clamp element includes two legs


70


extending from each end of clamp base


72


. At the end of each clamp leg


70


is a clamp head


62


which includes a clamp surface


64


and a wedging surface


66


. Clamping element


60


is positioned into the clamp element cavity


54


such that the clamping surface


64


is positioned closely adjacent to workpiece


40


. A clamp wedge is inserted between the two clamp heads


62


such that the wedge face


86


engages the wedging surfaces


66


of clamp heads


62


. The clamp wedge includes a wedge hole


82


which extends through clamp wedge


80


and is adapted to receive a bolt


90


. Bolt


90


extends through the clamp wedge and continues through the clamp hole


68


of clamping element


60


and into fastener cavity


56


of clamp body. The end of bolt


90


preferably is threaded so that it can be secured into fastener cavity


56


. At the top of bolt


90


is a bolt head


92


which has a larger diameter than the remaining section of bolt


90


. Bolt head


92


is designed to engage hole landing


84


in clamp wedge


80


. Workpiece


40


is secured to clamp body


48


by screwing bolt


90


into fastener cavity


56


which causes bolt head


92


to engage hole landing


84


thereby forcing clamping wedge


80


toward clamp base


72


. As clamp wedge


80


is forced toward clamp base


72


, wedge face


86


applies pressure to wedging surface


66


which in turn causes clamp surface


64


to engage workpiece


40


. Bolt


90


is screwed into fastener cavity


56


until a sufficient force is being applied by clamp surface


64


against workpiece


40


to adequately clamp workpiece


40


to clamp body


48


.




The exemplatory embodiments of clamping devices of the present invention which are illustrated in

FIGS. 2-29

are all related to positive clamping arrangements. However, it is understood that one skilled in the art can just as easily design a non-positive clamping device which incorporates the concepts set forth in this invention. Referring specifically to

FIG. 2

, a positive clamping device


100


is illustrated. A workpiece


102


is clamped between clamp body


108


and clamping element


120


. As can be appreciated, many workpiece configurations can be clamped by clamping device


100


. For illustrative purposes, two shaped workpieces are illustrated, one workpiece having a circular cross-section and another workpiece having a rectangular cross-section. Both workpieces are positioned against clamp base surface


110


and clamp side surface


112


of clamp body


108


. The clamp body includes a clamp element cavity


114


which is designed to receive a portion of clamping element


120


. In the base of clamp element cavity


114


is a fastener cavity


116


adapted to receive a bolt


160


which secures clamp element


120


to clamp body


108


. Clamp element


120


includes two clamp legs


128


connected together by a clamp arm


130


. On the top side of each clamp leg is a clamp head


122


which includes a clamp surface


124


. Clamp surface


124


is adapted to contact workpiece


102


and to rigidly secure workpiece


102


on clamp body


108


. The clamp surface may include a rough surface to improve the grip of the clamp surface to the workpiece during clamping. Each clamp leg also includes a clamp slot


136


located at the lower inner surface of the clamp leg. The clamp slot is adapted to receive an expander head


142


of expander


140


. Connected to the clamp arm


130


and between the two clamp legs


128


are two clamp fingers


132


. Clamp fingers


132


include a finger opening


134


adapted to receive the end of bolt


160


so that the clamp element


120


can be securely attached to the clamp body


108


. As best illustrated in

FIG. 4

, bolt


160


is inserted into the base of clamp body


108


through fastener cavity


116


and into finger opening


134


. Preferably, finger opening


134


includes a threaded surface so the end of bolt


160


can be threaded into finger opening


134


. Bolt


160


includes a bolt head


162


which engages fastener landing


117


to prevent bolt


160


from passing completely through fastener cavity


116


so that bolt


160


can properly secure clamp element


120


to clamp body


108


when bolt


160


is threaded into finger opening


134


. Expander


140


which is positioned between the two clamp legs


128


and secured in clamp slot


136


is also preferably positioned between the two clamp fingers


132


connected to clamp arm


130


. Expander


140


includes a heat jacket


144


and an electric cable


146


which is connected to the heat jacket. The electric cable provides an electric current from power source


150


to heat jacket


144


which in turn transfers heat to the expander material inside heat jacket


144


. Clamp body


108


includes a cable passage


118


to allow cable


146


to pass through the clamp body and connect to heat jacket


144


. Preferably, the expandable material of the expander is a shape memory alloy composed primarily of nickel and titanium.




As illustrated in

FIG. 2

, clamp


100


is a positive clamp arrangement. Clamp element


120


is originally shaped so as to naturally apply a clamping force to workpiece


102


as illustrated by the clamping force arrows in FIG.


2


. The release of the workpiece from clamping device


100


is illustrated in FIG.


4


. Power source


150


is activated which supplies an electric current through electric cable


146


to heat jacket


144


of expander


140


. Heat jacket


144


rises in temperature causing the expander material of the expander to increase in volume thereby causing expander ends


142


to apply a force to clamp legs


128


as illustrated by the force arrows in FIG.


4


. Expander


140


causes clamp legs


128


to move apart which results in the clamp heads moving toward one another thereby moving the clamp surface


124


of clamp head


122


away from workpiece


102


. This allows the workpiece


102


to be removed from clamp device


100


. A new workpiece can then be inserted into clamp device


100


by placing the workpiece on clamp base surface


110


and against clamp side


112


. Once the workpiece is properly positioned on clamp body


108


, power source


150


is deactivated which allows heat jacket


144


to begin cooling off. The cooling off of heat jacket


144


results in the expander material to return to its original shape and volume. The return of the expander to its original shape allows the clamping element


120


, which is preferably made up of a super elastic alloy primarily of titanium and nickel, to return to its natural clamped state.





FIGS. 6-10

illustrate another design for a positive clamping device. Referring now to

FIGS. 6

,


7


and


10


, clamp device


200


clamps a workpiece


202


onto clamp body


210


between clamp base surface


212


, clamp side surface


214


and clamp surface


224


. Clamp body


210


includes a clamp element cavity


216


wherein a clamp element


220


is rigidly secured to the clamp body by a bolt


270


. Clamp element


220


includes two legs connected at the two ends of clamp base


230


. Clamp base


230


includes at least one clamp opening


232


which allows bolt


270


, which is passed through fastener cavity


218


, to be threaded into the clamp opening


232


to secure clamp element


220


to the base of clamp element cavity


216


. Bolt


270


includes a bolt head


272


which engages fastener landing


219


of fastener cavity


218


so as to prevent bolt


270


from freely passing through fastener cavity


218


when clamping element


220


is secured to clamp body


210


. At the top ends of each clamp leg


228


is a clamp head


222


. The clamp head includes a clamp surface


224


adapted to engage workpiece


202


and a wedging surface


226


adapted to engage wedge face


252


. The wedging surface


226


is a sloped surface that slopes away from side surface


214


. The upper side of clamp base


230


includes an expander cavity


238


adapted to receive the base of expander


260


. The two sides of clamp base


230


each include a compressor slot


234


having two slot landings


236


. The two slot landings


236


are spaced apart and are sloped so as to slope toward one another. Compressor slot


234


is adapted to receive the compressor base


242


of compressor


240


. Compressor base


242


includes two base legs


244


shaped to engage the two slot landings


236


in compressor slot


234


. Preferably, the slope surfaces of base legs


244


are complementary to the slope surfaces of slot landings


236


. As illustrated in

FIG. 7

, clamp wedge


250


is inserted onto the top side of expander


260


. Preferably, clamp wedge


250


includes an expander cavity


259


to receive the top part of expander


260


. The two sides of clamp wedge


250


include a compressor opening


256


. Each compressor opening


256


includes two sloped opening landings


258


. The compressor openings


246


are adapted to receive the compressor head


256


of compressor


240


. Compressor head


246


includes two slope head legs


248


which are adapted to engage opening landings


258


of the compressor opening


256


of clamp wedge


250


. The head legs


248


are sloped so as to be complementary to the slope surfaces of opening landings


258


. Clamp wedge


250


includes a wedge hole


254


to allow heat core


264


to be inserted through clamp wedge


250


into expander opening


262


of expander


260


. Heat core


264


includes an electric cable


266


which is connected to a power source.




Expander


260


is a shape memory alloy preferably made up of a majority of nickel and titanium. Clamping element


220


is a super elastic alloy which is shaped to be in an unclamped position in its natural state. Compressor


240


is also preferably a super elastic alloy. The super elastic alloy for both the compressor and clamping element is preferably a nickel-titanium based alloy. Referring now to

FIGS. 7 and 8

, when the clamping element, compressor, clamp wedge and expander are connected together, compressor


240


causes clamp wedge


220


to be drawn toward the base of clamping element


220


. The movement of clamp wedge


250


toward the base of clamping element


250


in turn causes clamp heads


222


of clamping element


200


to move toward workpiece


202


thereby clamping workpiece


202


onto clamp body


210


as shown by the arrows in

FIGS. 7 and 8

. When the workpiece is to be removed from clamp device


220


, a current is supplied through electric cable


266


to heat core


264


causing the heat core to increase in temperature. The increase in temperature of the heat core in turn causes expander


260


to expand in volume as shown in FIG.


9


. The expansion of expander


260


causes a force to be applied to the underside of clamp wedge


250


causing the clamp wedge to move away from clamp base


230


. The upward movement of clamp wedge


250


causes compressors


240


to expand in length. Furthermore, the upward movement of clamp wedge


250


allows clamp heads


222


to move into their natural unclamped state thereby moving clamp surfaces


224


from workpiece


202


thereby allowing the workpiece to be removed from clamp device. Once the workpiece is removed, a new workpiece can be repositioned onto the clamp body. Once the workpiece is properly positioned on the clamp body, the current to the heat core is terminated thereby allowing heat core


264


to cool. The cooling of heat core


264


results in expander


260


to return to its original shape and volume which in turn results in compressor


240


to also return to its original shape thereby forcing clamp wedge


250


downwardly toward clamp base


230


. The downward movement of clamp wedge


250


in turn causes clamp heads


222


to move toward workpiece


202


causing clamp surfaces


224


to engage and clamp workpiece


202


onto clamp body


210


.




Referring now to

FIGS. 11-18

, there is illustrated another clamping device


300


which clamps a workpiece


302


to clamp body


310


at clamp base surface


312


and clamp side surface


314


. Clamp body


310


includes a clamp element cavity


316


adapted to receive clamp base


330


of clamping element


320


. Clamp base


330


includes two clamp openings


332


which are positioned to be aligned with the two fastener cavities


318


in the base of clamp element cavity


316


. Positioned between the two clamp openings


332


is preferably an expansion cavity


340


adapted to receive the base of expander


380


. Although this expander cavity is not specifically illustrated in

FIGS. 11-18

, such a an expander cavity would be similar in design to the expander cavity disclosed in

FIGS. 7 and 10

. Connected to each end of clamp base


330


is a clamp leg


328


. The top of each clamp leg


328


includes a clamp head


322


which has a clamp surface


324


facing workpiece


302


and a wedging surface


326


on the opposite side of clamp head


322


. Both wedging surfaces


362


slope downwardly and toward one another. Wedging surfaces


326


are adapted to contact wedge face


326


of clamp wedge


360


. Wedge faces


362


are slop surfaces which preferably have a complementary surface to the wedging surface


326


of clamping element


320


. Clamp wedge


360


includes two compressor openings


368


which are in longitudinal alignment with the two clamp openings


322


and two fastener cavities


318


. Compressor opening


368


is adapted to allow the end of compressor


340


to pass through clamp wedge


360


. Compressor


340


includes a compressor head


342


which includes a wedge engagement surface


350


. The wedge engagement surface is a sloped surface designed to engage the sloped surface of opening landing


370


of compressor opening


368


. Compressor head


342


is sized larger than the body of compressor


340


so as not to be able to pass through compressor opening


368


. The end of compressor


340


includes a threaded end


346


designed to pass through compressor opening


368


of clamping wedge


360


and clamp opening


332


of clamping element


320


and to engage the threaded surfaces of fastener cavity


318


. Clamp wedge


360


also includes an expander cavity


366


adapted to allow a heat core


384


to pass through the expander cavity and into the expander opening


382


of expander


380


. Heat core


384


has an electric cable


386


attached thereto.




In operation, compressor


340


is secured into fastener cavity


318


so as to force clamp wedge


360


toward clamp base


330


thereby resulting in wedge face


362


to engage wedging surfaces


326


of clamp head


322


thereby causing clamp surface


324


to engage with and clamp workpiece


302


onto clamp body


310


as shown in

FIGS. 12-14

. Preferably, clamping element


320


is shaped to be naturally oriented in an unclamped position and is made of a super elastic alloy. In addition, compressor


340


is also preferably made up of a super elastic alloy. Both the clamping element and compressor are preferably made up of an alloy including nickel and titanium. Expander


380


is preferably made up of a shape memory alloy. Preferably, the shape memory alloy is primarily a nickel-titanium alloy. The clamping force caused by compressor


340


forces clamp wedge


360


downwardly which results in clamp surfaces


324


to engage with workpiece


302


. When a workpiece is to be removed from clamp body


310


, an electric current is supplied through electric cable


386


to heat core


386


to heat the heat core. The heating of the heat core results in expander


380


to expand in size as illustrated in FIG.


15


. Expansion of expander


380


causes clamp wedge


360


to move upwardly and away from the base of the clamp base


330


of clamping element


320


. The upward movement of clamp wedge


360


allows clamping element


320


to move in its natural unclamped position thereby allowing clamp surfaces


324


to move away from workpiece


302


. Such movement of clamp surfaces


324


allows workpiece


302


to be removed from clamp body


310


. A new workpiece can be inserted onto the clamp body to be clamped. Once the workpiece is properly positioned onto clamp base surface


312


and clamp side surface


314


, the current supplied to heat core


384


is terminated thereby allowing expander


380


to return to its natural shape and size. Once expander


380


begins to contract in size, compressors


340


also begin to return to their natural shape due to their super elastic characteristics thereby causing clamp wedge


360


to move toward clamp base


330


. This movement of clamp wedge


360


causes clamp surface


324


to once again toward workpiece


302


thereby clamping the workpiece onto clamp body


310


.





FIGS. 17 and 18

illustrates an alternative design of compressor


340


. The threaded end of compressor


340


is substituted for a compressor cavity


344


which allows a securing lug


352


to be inserted therein. At the base of compressor cavity


344


there is a small compressor passage which is designed to allow the end of securing lug


352


to be passed therethrough but is small enough to prevent the lug head


354


from passing through the compressor passageway


348


. Securing lug


352


includes a threaded end


358


adapted to engage threaded surfaces of fastener cavity


318


. Lug head


358


includes a head slot


356


to allow the securing lug to be rotated so that the securing lug can be threaded into fastener cavity


318


to secure compressor


340


into position. The base of compressor


340


rests upon the top of clamp base


330


. Compressor passage


348


is in longitudinal alignment with clamp opening


332


and fastener cavity


318


so as to allow the end of securing lug


352


to pass through compressor passageway


348


and clamp opening


332


so as to engage fastener cavity


318


. The securing lug is designed to secure both the compressor and clamping element to clamp body


318


.




Another alternate embodiment of a clamping device is illustrated in

FIGS. 19-25

. Referring now to

FIGS. 19

,


21




22


,


23


and


25


, there is disclosed a positive clamping device


400


designed to clamp a workpiece


402


onto clamp body


410


. Clamp body


410


includes a clamp base surface


412


and a clamp side surface


414


adapted to receive workpiece


402


. Clamp body


410


also includes a clamp element cavity


416


adapted to receive a clamp mount


450


and a clamping element


420


rotatably mounted onto clamp mount


450


. The size of clamp element cavity


416


is selected to allow for a limited rotation of clamping element


420


on clamped element


450


. Clamp mount


450


includes a clamp mount leg


456


and two mount brackets


452


attached to the upper portion of both sides of clamp mount leg


456


. The height of clamp mount leg


456


is selected to be longer than the height of the two mount brackets


452


such that the mount brackets


452


do not contact the base of clamp element cavity


416


when secured to clamp body


410


. Clamp mount leg


456


includes a mount fastener cavity


460


extending through the mount leg to allow the end of a securing lug


464


to pass through mount leg


456


and engage fastener cavity


418


to the base of clamp element cavity


416


so as to secure clamp mount


450


to clamp body


410


. Securing lug


464


includes a threaded end


470


adapted to be threaded into the threaded surfaces of fastener cavity


418


. Securing lug


464


also includes a lug head


466


which has a larger diameter than the body of the securing lug so as not to allow the lug head to pass through fastener cavity


460


of clamp mount


450


. A head slot


468


is positioned on lug head


466


so that the securing lug can be threaded into fastener cavity


418


. The two mount brackets on clamp mount


450


are spaced from the sides of mount fastener cavity


460


. Positioned at each end of the mount brackets is a bracket opening


454


. Bracket openings


454


pass through mount brackets


452


at an axis transverse to the longitudinal axis of the mounting brackets. Clamp mount leg


456


includes a leg opening


458


which is in longitudinal alignment with the mounting brackets that are mounted on both sides of the mount leg. Clamping element


420


includes a clamp face


432


and a clamp surface


424


positioned at the upper part of the clamp face. Clamp surface


424


is adapted to clamp workpiece


402


onto clamp body


410


. Two clamp legs


434


are positioned on both sides of clamp surface


424


. Each clamp leg includes a leg opening


436


. On the backside of clamp element


420


there is mounted four clamp fingers


438


which are spaced apart at a substantially equal distance from one another. The clamp fingers include finger openings


440


which are alignment with and are approximately the same size as leg openings


436


on clamp legs


434


.




As best illustrated in

FIG. 25

, four clamp fingers are connected to each clamp leg


434


. Clamp element


420


is rotatably connected to clamp mount


450


by positioning the sides of the clamp fingers closely adjacent to the sides of mount brackets


452


and/or mount leg


456


until the opening in the fingers and the legs of clamping element


420


are in alignment with the openings in the mount brackets and mount leg of clamping element


450


. Once all the openings are properly aligned, clamp pins


462


are inserted through the openings so as to rotatably secure clamping element


420


to clamp mount


450


as illustrated in FIG.


21


.




Referring now to

FIGS. 22 and 25

, clamping element


420


includes two compression slots


426


positioned at the upper inner side of the clamping element. These compression slots are adapted to receive the ends of compressor


444


. Clamping element


420


also includes two expander slots


430


positioned at the lower back face of the clamping element. These expander slots are adapted to receive the ends of expander


480


. Expander


480


includes an expandable material


482


which is surrounded by a heat jacket


484


. An electric cable


486


is connected to heat jacket


484


.




Referring now to

FIG. 20

, when clamp device


400


is assembled, the clamp device is a positive clamping device. Compressor


444


which is made up of a super elastic alloy is sized so that when the two compressors are positioned in the compressor slots of the clamping element, the clamp face


432


is slightly rotated such that the clamp surface


424


engages workpiece


402


and clamps workpiece to clamp body


410


. The super elastic alloy preferably includes titanium and nickel. When a workpiece is to be removed or replaced from the clamp body, a current is supplied through electric cable


486


to heat jacket


484


to heat the heat jacket. When the heat jacket is heated, the two expanders


480


which are made up of a shape memory alloy, expand in size thereby applying a force onto the bottom portion of the clamp leg. The shape memory alloy is primarily made of titanium and nickel. This expansive force causes the clamped element


420


to rotate on the clamp mount and compresses compressor


444


together thereby resulting in the clamp surface


424


moving away from workpiece


402


. Once the clamp surface has moved a sufficient distance from the workpiece, the workpiece can be removed from the clamped body and a new workpiece can be repositioned in the clamp body. To cause a workpiece to once again be clamped to the clamp body, the current to the heat jacket is terminated thereby allowing the heat jacket to cool. When the heat jacket begins to cool, the expander retracts to its original shape and volume thereby allowing the compressors to move to their original natural position which in turn causes the clamping element to rotate on the clamp mount so that the clamp surface engages workpiece


402


to clamp the workpiece to clamp body


410


.




In another embodiment of the present invention, a positive clamping device


500


is illustrated in

FIGS. 26-29

. Clamp device


500


includes a clamp body


510


mounted onto a bolster plate


512


. Clamp body


510


includes four fastener cavities


516


. The fastener cavities are sized to allow the body of a securing lug


600


to pass through the clamp body and to engage a threaded plate cavity in the bolster plate. The securing lug includes a threaded end


604


and a lug head


602


. A portion of the top side of the fastener cavity can be sized so as to allow the lug head


602


to fit inside the portion of the expanded cavity. The lug head includes a lug slot


606


adapted to receive a tool for turning the securing lug so that the secure lug can fasten clamp body


510


to bolster plate


512


. Clamp body


510


includes a clamp arm slot


514


, longitudinally positioned at the top of the clamp body and between the two sides of the clamp body. The clamp arm slot includes a base surface which slopes upwardly from the front to the rear of the clamp body. A clamp arm is mounted in clamp arm slot


514


and is rotatably mounted to clamp body


510


. Clamp arm


530


includes a connector opening


534


which traverses the longitudinal axis of the clamping arm. The connector opening is adapted to receive a connector pin


550


which is passed through arm slot opening


515


in clamp body


510


and through connector opening


534


of clamp arm


530


thereby rotatably connecting clamp arm


530


to clamp body


510


to allow for rotation of clamp arm


530


in clamp arm slot


514


. Clamp arm


530


includes an arm head


536


which includes a pin opening


532


passing through the top and bottom ends of the arm head. A clamping pin


522


is inserted through pin opening


532


and is secured in the pin opening at the bottom side of arm head


536


by a pin bolt


528


. The clamping pin includes a pin head


523


at the top of the pin which prevents the top of the pin from passing through pin opening


532


at the top of the arm head


536


. At the bottom of clamping pin


522


is a pin face adapted to engage a workpiece and clamp a workpiece between the pin face and bolster plate


512


as illustrated in

FIGS. 27 and 28

. Clamp arm


530


also includes a clamp end


538


having a bearing surface


540


facing the base of clamp arm slot


514


. Clamp body


510


also includes a shuttle chamber


560


positioned in the interior of the clamp body and beneath clamp arm slot


514


. Rearwardly of shuttle chamber


560


is a narrower spring chamber


564


. Shuttle chamber


560


is adapted to receive a shuttle


582


. Shuttle chamber


560


is sized to allow shuttle


582


to longitudinally move within the shuttle chamber. Positioned in spring chamber


564


is a release spring


576


. The release spring is preferably made up of a shape memory alloy. At one end of the spring chamber there is a spring wall


572


. The other end of the spring chamber opens up into the larger diameter shuttle chamber. Spring chamber


564


also includes a spring chamber opening


566


providing a passage between the spring chamber and the side of clamp body


510


. The spring chamber opening allows for a release spring cable


580


to connect to the release spring or a heating element positioned adjacent to the release spring. The release spring is positioned in the spring chamber so that one end of the release spring engages spring wall


572


and the other end of the release spring engages one end of shuttle


582


. Preferably, shuttle


582


includes a spring cavity on release face


586


of shuttle


582


which is adapted to receive the end of release spring


576


. At the opposite end from the release face of shuttle


582


there is a compression face


584


which engages one end of compression spring


574


. Preferably, compression face


584


includes a compression cavity adapted to receive the end of compression spring


574


. The other end of compression spring


574


engages compression wall


568


. Compression wall


568


is preferably a removable wall which allows access to the shuttle chamber. Preferably, compression wall


568


includes a threaded end


569


which can be threaded into one end of the shuttle chamber as illustrated in FIG.


28


. Shuttle chamber


560


includes a shuttle chamber opening


562


which provides a passageway from the shuttle chamber to the side of clamp body


510


. The chamber opening


562


provides an opening for compression spring cable


578


to be attached to compression spring


574


or a heating element positioned closely adjacent to the compression spring. The compression spring is preferably made up of a shape memory alloy. The compression spring preferably has a larger spring modulas than the spring modulas of the release spring. Shuttle


582


includes a sloped notch


588


positioned at the top of the shuttle which has a surface that slopes downwardly from the front to the rear of the shuttle. Shuttle chamber


560


also includes a pin opening


596


which provides a passageway through the top of the shuttle chamber to the clamp arm slot. Pin opening


596


is adapted to receive a bearing pin


590


. Bearing pin


590


includes a pin top


592


adapted to engage the bearing surface


540


of clamp aim


530


. Pin bottom


594


is adapted to engage the sloped notch


588


of shuttle


582


.




The operation of the clamping device will now be described. As illustrated in

FIG. 28

, the spring modulas of compression spring


574


is larger than the spring modulas of release spring


576


thereby forcing shuttle


582


toward the back end of shuttle chamber


560


. The movement of shuttle


582


toward the back end of shuttle chamber


560


causes bearing pin


590


to move upwardly through pin opening


596


and forces arm end


538


upwardly. The upward movement of arm end


538


causes clamp arm


530


to rotate on connection pin


550


which in turn causes arm head


536


to move downwardly causing pin face


524


to engage workpiece


502


and clamp workpiece


502


to bolster plate


512


. The force applied by clamping pin


522


onto workpiece


502


can be increased by heating compression spring


574


to cause the compression spring to further expand. This expansion of compression spring


574


is accomplished by providing a current through compression spring cable


578


to heat compression spring


574


and/or a heating element positioned closely adjacent to compression spring


574


. When the workpiece


502


is to be removed from clamp device


500


, the current, if any, which is being supplied through spring cable


578


is terminated. In addition, the current through spring cable


580


is activated so as to supply a current directly to release spring


576


and/or a heating element positioned closely adjacent to the release spring so as to cause the release spring to expand in size. The expansion of the release spring causes shuttle


582


to move toward the front end of shuttle chamber


560


. As shuttle chamber


582


moves toward the front of shuttle chamber


560


, bearing pin


590


lowers in pin opening


596


as pin bottom


594


follows the downwardly sloped surface on slope notch


588


of shuttle


582


. The downward movement of bearing pin


590


allows arm end


538


to move downwardly thereby causing arm head


536


to move upwardly. The upward movement of arm head


536


results in the disengagement of clamping pin


522


from workpiece


502


thereby allowing the workpiece to be removed from clamping device


500


. When a workpiece is to be once again clamped in position, the current supply through spring cable


580


is terminated thereby reducing the heat being supplied to release spring


576


. As release spring


576


cools, the spring modulas decreases until it is once again less than the spring modulas of compression spring


574


. As the spring modulas of release spring continues to decrease, compression spring


574


forces shuttle


582


to move rearwardly in shuttle chamber


560


. The rearward movement of shuttle


582


causes bearing pin


590


to rise within pin opening


596


thereby causing clamp arm


530


to move into a clamping position whereby clamping pin


522


clamps workpiece


502


to bolster plate


512


. The clamping force applied by clamping pin


522


onto workpiece


502


can be further increased by heating the compression spring to cause the compression spring to further expand and to force bearing pin


590


further upwardly.




The invention has been described with reference to a preferred embodiments and alternates thereof. It is believed that many modifications and alterations to the embodiments discussed herein will readily suggest themselves to those skilled in the art upon reading and understanding the detailed description of the invention. It is intended to include all such modifications and alterations in so far as they come within the scope of the present invention.



Claims
  • 1. A method of clamping a workpiece comprising:a. providing a clamping device having a base, and an actuator including a heat altering material adapted to move a clamping member between a clamped position wherein said workpiece is held by said clamping member in a clamped state and an unclamped position wherein said workpiece is removable from said clamping device; b. providing a flexible material between said heat altering material and said clamping member; c. heating said heat altering material to cause a flexible material to move and engage said clamping member thereby causing said clamping member to move to said unclamped position; d. positioning said workpiece proximate said clamping member; and, e. cooling said heat expandable material to cause said clamping member to move back to said clamped position to clamp said workpiece in said clamping device.
  • 2. The method of claim 1, wherein said heat expandable material includes a shape memory alloy.
  • 3. The method of claim 2, wherein said shape memory alloy includes nickel and titanium.
  • 4. The method of claim 2, wherein said flexible material includes a super elastic alloy.
  • 5. The method of claim 4, wherein said super elastic alloy includes nickel and titanium.
  • 6. The method of claim 1, wherein said flexible material includes a super elastic alloy.
  • 7. A method of clamping a workpicce comprising:a. providing a clamping device having a base, and an actuator including a heat altering material adapted to move a clamping member between a clamped position wherein said workpiece is held by said clamping member in a clamped state and an unclamped position wherein said workpiece is removable from said clamping device; b. providing a flexible material between said heat altering material and said clamping member; c. cooling said heat altering material to reduce the amount of force applied to a flexible material thereby allowing said clamping member to move to said unclamped position; d. positioning said workpiece proximate said clamping member; and, e. heating said heat altering material to cause said clamping member to move back to said clamped position to clamp said workpiece in said clamping device.
  • 8. The method of claim 7, wherein said flexible material includes a super elastic alloy.
  • 9. The method of claim 7, wherein said heat altering material includes a shape memory alloy.
  • 10. The method of claim 9, wherein said shape memory alloy includes nickel and titanium.
  • 11. The method of claim 9, wherein said flexible material includes a super elastic alloy.
  • 12. The method of claim 11, wherein said super elastic alloy includes nickel and titanium.
  • 13. A method of clamping a workpiece comprising:a. providing a clamping device having a holding member, a clamping member and a force creation device to apply a force to said clamping member, said clamping member including a super elastic alloy, said force creation device adapted to selectively apply said force to said clamping member to move said clamping member between a clamped position wherein said workpiece is clamped between said clamping member and said holding member and an unclamped position wherein said workpiece is removable from said clamping device; b. applying said force to said clamping member to move said clamping member to said unclamped position; and c. reducing said force to said clamping member to move said clamping member to said clamped position.
  • 14. The method of claim 13, wherein said force creation device includes a shape memory alloy, said force from said force creation device at least partially produced by heating said shape memory alloy.
  • 15. The method of claim 13, wherein said clamping member includes a flexible metal material and a clamp face, said flexible metal material at least partially positioned between said force creation device and said clamp face.
  • 16. The method of claim 15, wherein said flexible metal material includes a super elastic alloy.
  • 17. The method of claim 16, wherein said force creation device includes a shape memory alloy, said force from said force creation device at least partially produced by heating said shape memory alloy.
  • 18. The method of claim 17, wherein said flexible metal material includes a super elastic alloy includes nickel and titanium.
  • 19. The method of claim 18, wherein said shape memory alloy includes nickel and titanium.
  • 20. A method of clamping a workpiece to a clamping device comprising:(a) providing a clamping arrangement having a clamping surface adapted to contact and secure a workpiece in a clamped state and a mechanism to move said clamping surface, said clamping surface positioned in a clamped orientation, said clamping arrangement includes a flexible metal component, said mechanism to move including a heat altering material; (b) heating said heat altering material to cause said flexible metal to move from a first orientation to a second orientation thereby causing said clamping surface to be positioned out of said clamped orientation and into an unclamped orientation; (c) positioning said workpiece in a clamping relationship with said clamping arrangement wherein said clamping surface is positioned at least closely adjacent to a surface of said workpiece; and, (d) cooling said heat altering material to cause said flexible metal component to move back to said first orientation thereby causing said clamping surface to move back to said clamped orientation to secure said workpiece in said clamping device.
  • 21. The method as defined in claim 20, wherein said flexible metal material is a super elastic alloy.
  • 22. The method as defined in claim 20, wherein said mechanism to move includes a shape memory alloy which applies a force to said flexible metal material when heat is applied to said shape memory alloy.
  • 23. The method as defined in claim 20, wherein said clamping arrangement including a super elastic component and a non-super elastic component.
  • 24. The method as defined in claim 20, wherein said flexible metal component has a natural orientation in said first orientation.
  • 25. The method as defined in claim 20, wherein said flexible metal component has a natural orientation in said second orientation.
  • 26. The method as defined in claim 20, wherein said heat to said heat altering material is from a heating source selected from the group consisting of electric resistant heating, chemical reaction heating, thermal heating, and combinations thereof.
  • 27. The method as defined in claim 20, wherein said heat altering material includes a shape memory alloy.
  • 28. The method as defined in claim 27, wherein said flexible metal material is a super elastic alloy.
  • 29. The method as defined in claim 28, wherein said mechanism to move includes a shape memory alloy which applies a force to said flexible metal material when heat is applied to said shape memory alloy.
  • 30. The method as defined in claim 29, wherein said clamping arrangement including a super elastic component and a non-super elastic component.
  • 31. The method as defined in claim 30, wherein said flexible metal component has a natural orientation in said first orientation.
  • 32. The method as defined in claim 30, wherein said flexible metal component has a natural orientation in said second orientation.
  • 33. The method as defined in claim 28, wherein said clamping arrangement including a super elastic component and a non-super elastic component.
  • 34. The method as defined in claim 27, wherein said mechanism to move includes a shape memory alloy which applies a force to said flexible metal material when heat is applied to said shape memory alloy.
  • 35. A method of clamping a workpiece to a clamping device comprising:(a) providing a clamping arrangement having a clamping surface adapted to contact and secure a workpiece in a clamped state and a mechanism to move said clamping surface, said clamping surface positioned in an unclamped orientation, said clamping arrangement including a flexible metal component, said mechanism to move including a heat altering material; (b) positioning said workpiece in a clamping relationship with said clamping arrangement wherein said clamping surface is positioned at least closely adjacent to a surface of said workpiece; and (c) heating said heat altering material to cause said flexible metal component to move from a first orientation to a second orientation to cause said clamping surface to be positioned in a clamped orientation to secure said workpiece in said clamping device.
  • 36. The method as defined in claim 35, wherein said heat altering material includes a shape memory alloy.
  • 37. The method as defined in claim 35, wherein said heat altering material applies a force to said flexible metal material when heat is applied to said heat altering material.
  • 38. The method as defined in claim 35, including:(d) cooling said heat altering material to cause said flexible metal component to move back to said first orientation thereby causing said clamping surface to move back to said unclamped orientation.
  • 39. The method as defined in claim 35, wherein said clamping arrangement including a super elastic component and a non-super elastic component.
  • 40. The method as defined in claim 35, wherein said flexible metal component has a natural orientation in said first orientation.
  • 41. The method as defined in claim 35, wherein said flexible metal component has a natural orientation in said second orientation.
  • 42. The method as defined in claim 35, wherein said mechanism to move includes a shape memory alloy which applies a force to said flexible metal material when heat is applied to said shape memory alloy.
  • 43. The method as defined in claim 35, wherein said flexible metal material includes a super elastic alloy.
  • 44. The method as defined in claim 43, wherein said heat altering material includes a shape memory alloy.
  • 45. The method as defined in claim 44, wherein said heat altering material applies a force to said flexible metal material when heat is applied to said heat altering material.
  • 46. The method as defined in claim 45, including:(d) cooling said heat altering material to cause said flexible metal component to move back to said first orientation thereby causing said clamping surface to move back to said unclamped orientation.
  • 47. The method as defined in claim 46, wherein said clamping arrangement including a super elastic component and a non-super elastic component.
  • 48. The method as defined in claim 47, wherein said flexible metal component has a natural orientation in said first orientation.
  • 49. The method as defined in claim 47, wherein said flexible metal component has a natural orientation in said second orientation.
  • 50. The method as defined in claim 47, wherein said heat to said heat altering material is from a heating source selected from the group consisting of electric resistance heating, chemical reaction heating, thermal heating, and combinations thereof.
  • 51. A method of clamping a workpiece to a clamping device comprising:(a) providing a clamping arrangement having a clamping surface adapted to contact and secure a workpiece in a clamped state and a mechanism to move said clamping surface, said mechanism to move including a first and a second heat altering materials; (b) positioning said workpiece in a clamping relationship with said clamping arrangement wherein said clamping surface is positioned at least closely adjacent to a surface of said workpiece; (c) heating said first heat altering material to cause said clamping surface to move into a clamped orientation to secure said workpiece in said clamping device; and, (d) at least partially reducing heat to said second heat altering material, said heat being at least partially reduced to said second heat altering material at a time selected from the group consisting of prior to said first heat altering material being heated or simultaneous to said first heat altering material being heated.
  • 52. The method as defined in claim 51, including the step of heating said second heat altering material to cause said clamping surface to move into an unclamped orientation with respect to said workpiece.
  • 53. The method as defined in claim 52, including the step of at least partially reducing heat to said first heat altering material at a time selected from the group consisting of prior to said second heat altering material is heated or simultaneous to said second heat altering material is heated.
  • 54. The method as defined in claim 53, wherein said first heat altering material includes a shape memory alloy.
  • 55. The method as defined in claim 54, wherein said second heat altering material includes a shape memory alloy.
  • 56. The method as defined in claim 51, wherein said first heat altering material includes a shape memory alloy.
  • 57. The method as defined in claim 51, wherein said second heat altering material includes a shape memory alloy.
Parent Case Info

This application is a continuation of U.S. patent application Ser. No. 09/272,685, filed on Mar. 19, 1999 which in turn is a divisional of U.S. patent application Ser. No. 08/925,449, filed on Sep. 8, 1997, now abandoned, which claims the benefit of U.S. Provisional Application Serial No. 60/027,533, filed on Oct. 7, 1996.

US Referenced Citations (13)
Number Name Date Kind
RE. 32704 Schron Jun 1988
4715637 Hosoda Dec 1987
4721293 Schron Jan 1988
4743079 Bloch May 1988
4802661 Jewett Feb 1989
4804171 Dornfeld Feb 1989
4874156 Goldzweig Oct 1989
4915273 Allen Apr 1990
5052092 Vallaruri et al. Oct 1991
5137263 Savoie et al. Aug 1992
5197720 Renz Mar 1993
5695393 Granziera Dec 1997
6109602 Schron, Jr. et al. Aug 2000
Foreign Referenced Citations (2)
Number Date Country
59-187470 Oct 1984 JP
5-67434 Sep 1993 JP
Provisional Applications (1)
Number Date Country
60/027533 Oct 1996 US
Continuations (1)
Number Date Country
Parent 09/272685 Mar 1999 US
Child 09/527609 US