GB2182271A - Quick engaging clamping device - Google Patents

Abstract

A quick engaging clamping device has two jaw members with opposing gripping surfaces. A threaded bolt 18 has one end with a handle for rotating the bolt and is rotatably connected to a first of the jaw members. A quick engagement device is connected to a second of the jaw members and is selectively engagable with, or disengagable from, the bolt. The engagement mechanism has a pair of half nut members 42, 44 with opposing semi-cylindrical recesses having female threads on opposite sides of the bolt. Springs 72, 74 normally bias the half nut members towards each other so the female threads engage the bolt and rotation of the bolt moves the gripping surfaces together or apart. A first cam mechanism 84 (85) between the half nut members moves the half nut members apart so the female threads disengage from the bolt when the first cam mechanism is in one position. A second cam mechanism 114 is rotatable with the bolt and cooperates with the first cam mechanism for moving the first cam mechanism towards the one position when the bolt is rotated in one direction and for moving the first cam mechanism away from the one position when the bolt is rotated in a direction opposite the one direction so the springs move the half nut members together and the female threads engage the bolt. <IMAGE>

Description

SPECIFICATION Quick engaging clamping device Background of the invention This invention relates to a quick engaging clamping device orvises wherein half nuts are engaged with a screw or disengaged from the screw by rotation of the screw.

Common clamping devices, particularlyvises, include a pair of opposing jaw members which are brought into engagement with each other or moved away from each other by rotation of a screw which interconnects the members. A relatively fine thread is frequently used on the screw in order to increase the clamping force. This means that moving thejaw members apart by rotation ofthe screw is a relatively slow process. Quick engaging clamping mech anisms have therefore been developed to move the jaw members apart more quickly and quickly engage them when it is desired to clamp something between the jaws. Prior art devices of this type typically include a screw rotatably mounted on one of the members and a half nut mounted on the other member.A separate lever on the front of the vise can move the half nut into engagement with the screw or move the half nut awayfrom the screw. In this way the device is capable ofquick release as well as instantaneous grip. However, it should be noted that the operation of the vise may require two hands - one to move the lever and the other to move the jaws ofthe vise.

Forsome purposes it is desirableto providesingle handed operation of the vise. This could be achieved by a quick release and instantaneous engaging mechanism operated by the handletypicallyconnected to the screw. One such device shown in my previous United States patent #4.402.370.

Summary of the invention Aquickengaging clamping device according to the invention has two jaw members with opposing gripping surfaces. Athreaded bolt has one end with a handle for rotating the bolt. The bolt is rotatably connectedto a first ofthe jaw members. Aquicken gagement means is connected to a second ofthe jaw members and is selectively engageable with ordis engagablefrom the bolt. The engagement means has a pair of half nut members with opposing semicylindrical recesses having female threads on opposite sides of the bolt. There is means for normally biasing the half nut members towards each other so the female threads engage the bolt and rotation of the bolt moves the gripping surfaces together or apart.There is first cam means between the half nut members for moving the half nut members apart so the female threads disengage from the bolt when the first cam means is one position. There is second means rotatable with the bolt and cooperating with the first cam means for movingthefirst cam means towards the one position when the bolt is rotated in one direction and for moving the first cam means away from the one position when the bolt is rotated in a direction opposite the one direction so the means for normally biasing movesthehalfnutmem- bers together and the female threads engage the bolt.

The first cam means may comprise a linearcam member slidably received by both half nut members formovementalong an axis, the linearcam member having cam surfaces inclined with respect to the axis which slidably engage inclined cam surfaces of both half nut members.

The second cam means may include a stationary cam member and a rotatable cam member which is rotatable with the bolt, slidable along the bolt, and which contacts the linear cam member. The stationark cam member and the rotatable cam member have mutually contacting helical cam surfaces so rot- ation of the bolt in the one direction moves the rotatable cam member along the boltto movethefirst cam meanstowardsthe one position.

The rotatable cam member may comprise a plurality of segments held together about the bolt by retaining means for normally urging the rotatable cam member to rotate with the bolt, but for permitting the bolt to rotate relative to the rotatable cam member when atorque beyond a predetermined maximum torque is applied to the rotatable cam member.

The stationary cam member may have one helical cam surface for each segment of the rotatable cam member, each cam surface of the stationary cam member curving helicallyfrom afirst point on said each cam surface furthestfromthefirst cam means to a second point closest to the first cam means. The stationary cam member in this case has connecting surfaces between the first and second points of adjacent cam surfaces,the connecting surfaces being parallel to the axis ofthe first cam member. Cam surfaces ofthe segments of the rotatable cam member curve helically from a first point fu rthest from the firstcam means to a second point closest to the first cam means and adjacent segments have adjacent surfaces which are parallel to the axis ofthefirstcam means.

Briefdescription ofthe drawings Figure lisa perspective view, of a quick engaging clamping device according to a firstembodimentof the invention, shown partly in ghost; Figure2 is a perspective view, partly broken away, of a quick engaging clamping device according two a second embodiment of the invention; Figure 3 is a perspective view of the quick engagement means and a portion ofthe bolt utilized in the devices of Figures 1 and 2; Figure4is a sideelevation ofthe quickengage- ment means of Figure 3 shown engaging the bolt; Figure5is an elevational viewsimilarto Figure 4, shown with the bolt disengaged; Figure 6is a sectional viewtaken along line 6-6 of Figure4; and Figure 7is a sectional view taken along line 7-7 of Figure 5.

Description of the preferred embodiments Figure 1 illustrates a quick engaging clamping device in the nature of a vise 1 which includes a firstjaw member2 and a second jaw member4. The bottom part of jaw member 4 comprises a mounting plate 6 having a pairofapertures 8 and 10for bolting or screwing the mounting plate to an appropriate surface. The jaw members have opposing gripping surfaces 12 and 14. Achannel 16 is formed along thetop side of mounting plate 6 which forms a 9 u ideway for movement ofjaw member 2.

A bolt 18 is rotatably connected to jaw member2 byajournal 20. In this manner, the bolt 18 jaw member 2 move together in the axial direction ofthe boltand along channel 16.Aconventional handle 22 intheformofanelongated rod with end caps 28 and 30 passes freely through aperture 24 of cylindrical member 26 on the front end of bolt 18. As described thus far, vise 1 is conventional.

An arched housing 32 is connected to the front of mounting plate 6 by rivets 34. In a conventional vise, this housing would have a threaded aperture for receiving bolt 18. In the type of quick engaging device disclosed, housing 32 contains an interior quick end gagement device 36 which is thus connected to the second jaw member 4 and is selectively engagable with or disengagablefrom the bolt 18 by rotation of bolt 18 as described below.

The quick engagement device 36 is capable of being employed in a variety of clamping devices. For example, another embodiment is shown in Figure 2 where equivalent parts have the same numbers as in Figure 1, but with the additional designation of a prime mark. In this case, member2 has an elongated, open-bottomed channel member 38 extending rearwardlytherefrom. The channel member is slid ably received in a rectangular aperture 40 extending through jaw member 4'. In this case, the housing 32 is omitted and quick engagement device 36' is mounted on top of mounting plate 6' within channel 38.

Referring to Figures 3-7, these illustrate in more detail quick engagement device 36 from Figure 1 which is identical to the device 36' of Figure 2.

Device 36 includes a pair of half nut members 42 and 44 respectively provided with female threads 46 and 48, shown best in Figure 5, within opposing semi-cylindrical recesses 50 and 52 shown best in Figure 7. The threaded recesses are seen to be on opposite sides of bolt 18.

The quick engagement device 36 includes a hous ing formed by a top plate 54, a bottom plate 56, a front plate 58, and a back plate 60. A plurality of bolts 62 secure the top and bottom plate to the front and back plate. The front plate has rearwardly extending flanges 64 and 66 shown in Figure 6. The back plate has similarflanges 68 and 70 shown in Figure 7. The configuration ofthe flanges is best understood, how ever, with reference to Figure 3 which shows only flanges 66 and 68. These flanges serve as guideways forguiding the half nut members42 and 44,while permitting vertical movement thereof. The front and back plates have apertures 110 and 112 respectively, shown in Figure 5, for rotatably receiving bolt 18.

Two coil springs 72 are 74 and compressibly re ceived between top plate 54 and half nut member42.

Likewise, coil springs 76 and 78 are compressively received between the bottom plate 56 and half nut member 44. The ends ofthe springs are received in corresponding cylindrical recesses in the half nut members and the top and bottom plates, for ex- ample spring 78 has its top end received in recess 80, while its bottom end is received in recess 82 as designated in Figure 4. The coil springs serve as means for normally biasing the half nut memberstowards each other so the female threads 46 and 48 engage the bolt 18. In this position, shown in Figures 4 and 6, rotation of the bolt 18 moves, for example, jaw members 2 and 4 of Figure 1 as well gripping surfaces 12 and 14togetherwhen the bolt 18 is rotated in the clockwise direction using handle 22. This corresponds to normal operation of a vise.

A pair offirst cams 84 and 85, which are mirror images of each other, are located on each side ofthe half nut members 42 and 44as shown in Figure 6.

These cams are guidably received by keyways in the frontand back plates 58 and 60. For example, as shown in Figure 3, first cam 84 is received in keyways 86 and 88 in the front and back plates. These cams move along an axis, such as axis 87 for cam 84 shown in Figure 4. Each ofthe first cam 84 and 85 includes a pair of arrowhead-like configuration 90 and 92. As shown in Figures 4 and 5, each ofthese configurations includes a pair of inclined cam surfaces, for example surfaces 94 and 96 of configuration 90. Opposing notches are formed in the half nut members for receiving the arrowhead configuration of each first cam. For example,the half nut members have opposing notches 98 and 100 for arrowhead configuration 90.Each notch has an inclined cam surfaceforsildably engaging the inclined cam sur faces of one of the first cam members. For example, notches 98 and 100 are provided with inclined cam surfaces 102 and 104, respectively shown in Figure 3.

It may be seen by comparison of Figures 4 and 5 how thefirstcams 84 and 85 act as linearcams which tend to move the half nut members 42 and 44apartand out of engagement with bolt 18 as each ofthefirst cams moves axially to the right on the position of Figure 4to the position of Figure 5.

A U-shaped cam cover 106 is connected to the front offront plate 58 as shown in Figure 3,4 and 5.

The cam cover has an aperture 108 for bolt 18. A second cam mechanism 114 is located within cam cover 106. This includes a stationary cam member 116 connected to the front of the cam cover by rivets 1 shown in Figure 3. The stationary cam member has four distinct helical cam surfaces, each of which extends 90 about the stationary cam member. Two of these helical cam surfaces 119 and 120 are seen in Figures 4 and 5. The othertwo helical cam surfaces on the opposite side ofthe cam member 116 are identical. The shape of the helical cam surfaces is best appreciated with reference to Figure 3 which shows cam surface 119. Helical cam surface 119 curves helicallyfrom afirstpoint 112, which is furthest from the first cams 84 and 85 in the direction of the axes of the cams, to a second point 124 which is closestto the first cams. Adjacent cam surfaces on the stationary cam member are connected by a flat surface parallel to the axes ofthefirstcams,forex ample connecting surface 126 between cam surfaces 119 and 120. As may be observed in Figure 3, bolt 18 passes through an aperture 128 in staionarycam member 116. The bolt then passes through ring shaped clutch member 130 located between statio nark cam member 116 and front plate 58. The clutch member hastwo halves 132 and 134,shownin Figure 3, which are slightly spaced-apart as may be observed in Figure 4.Thus the clutch member may be held tightly against bolt 18 when sufficient force is applied squeezing thetwo halvestowardseach other.

The second cam mechanism 114 also includes a rotatable cam member 138 which has four separate quadrants, each extending aboutthe bolt18slightly less than 90". Two ofthe quadrants 140 and 142 are visible in Figures 3-5. Two similar quadrants are on the opposite side of the bolt. Because each ofthe quadrants extends over slightly less than 90% they are together capable of being squeezed together tightly over clutch member or collar 130 so asto squeeze the two halves ofthe clutch member against the bolt 18. This is accomplished by means of a pair ofspaced-apartring clips 144and 146.Thesefit within circumferential grooves 148 and 150 in the rotatable cam member shown in Figure 3.Each of the rings is split, such as split 152 in ring clip 144 as shown in Figure 4. The ring clips are of a resilient material such as spring steel and, unstressed, assume a diameterslightlysmallerthan the diame terofthe grooves in the quadrants. In this manner, the ring clips tends to squeeze the quadrants tow ardsthecenterofshaft 18 and thereby squeeze togetherthe two halves of clutch member 130 to fric tionallyengagetheclutch member with bolt 18.

It may be observed that each of the quadrants comprising the rotatable cam member has a helical cam surfacesimilartothe cam surfaces ofthestati- onarycam member 116. For example, quadrant 140 has cam surface 154, while quadrant 142 has cam surface 156, both shown in Figure 5. Each cam surface curves helicallyfrom a first point furthest from thefirstcams 84 and 85 in a direction parallel to the cam axes, such as point 158 of cam surface 154 shown in Figure 5, to a pointclosestto the first cams, such as point 160 of cam surface 154.Adjacent cam surfaces are separated by adjacent surfaces which are parallel to the axes ofthefirst cam members, suchassurface162Ofquadrant140.

As bestseen in Figure 5, both the boltand halfnut members have threads which have adjacent surfaces inclined away from the front end ofthe boltwhere the handle is located. For example, half nut member 42 has threads with inclined surfaces 164,whilethe bolt has threads with inclined surfaces 166. These inclined surfaces make iteasierforthe half nut mem bersto re-engagewiththe boltthanwould bethe case ifthethreads had sides more perpendicularto the axis ofthe bolt.

Operation The operation of vise 1 shown in Figure 1 is ex plained with additional reference to Figure 4-7. The operation ofthe vise of Figure 2 is the same.

The first step in using the vise 1 is to separate the gripping surfaces 12 and 14 of the jaw members 2 and 4. This is accomplished by grasping handle 22 and turning it 90" counter clockwise. Figure 4shows the initial position. Figure 5 shows the position after turning 90" counter clockwise. The effect is to move point 158 of quadrant 140 from point 122 on statio nary cam member 116 until it is near point 124. Likewise the pointon each ofthe quadrantsfurthestfrom the first cam is moved from a point on the stationary cam memberfurthestfromthefirstcam memberto one ofthe four points on the stationary member closest to the first cams.Thus the entire rotatable cam member 138 slides along clutch member 130 in the direction ofthe longitudinal axis of bolt 18. This is accomplished becausethroughoutthis one quarter turn,thespring clips 144 and 146 hold the rotatable cam member and the clutch member into rotatable engagementwith bolt 18. This causesthe cam surfaces of the rotatable cam memberto move slidably along the cam surfaces ofthe stationary cam member. The final position is shown in Figure 5. The rotation ofthe rotatable cam member in the counter clockwise direction is terminated when the rotatable cam member contacts front plate 58.The spacing between the stationary cam member and the front plate is such asto prevent the points on each ofthe quad rants fu rthestfrom the first cam from passingcom- pletely overthe points on the stationary cam member closest to the first cams. This may be observed in Figure 5.

The rotation of the bolt one quarterturn thereby causes movement of the rotatable cam membertow ards the first cam member. It may be observed that the clutch member 130 is thereby pushed against the first cam members to move the first cam members along their longitudinal axes to the right fro the point of view of the Figure 4 and 5. The inclined cam surfaces on the first cams and the corresponding in clined surfaces ofthe half nut members thereby slide overeachotherto move the half nut members apart as shown in Figure 5 so the threads ofthe half nut members disengage from the threads of the bolt.

Thusthe bolt may befreely pulled or pushed along its longitudinal axis to separate the gripping surfaces of the jaw members ofthevise.

Once this is accomplished, the material to be clamped is placed between the gripping surfaces of thejaw members. The bolt 18 isthen rotated clockwise from the point of view of Figure 1 by means of handle 22 for 900. This reverses the process just described and causes the rotatable cam memberto rotate with the bolt until the cams re-achieve therelative position shown in Figure 1. At this point, the connecting surfaces, such as surface 126 of the stati- onarycam member, contact one ofthe adjacentsur- faces ofthe rotatable cam members, such as surface 162. Further rotation of the rotatable cam members is prevented and the bolt rotates relative to the rotatable cam member, the slippage being permitted by ring clips 144 and 146. Thus it may be observed that the clamping device is released so the jaws can be moved apartwith only one quarterturn inthecounterclockwise direction ofthe bolt. Likewise, a one quarterturn in the clockwise direction quickly engages the clamping device for normal operation.

Claims (14)

1. Aquickengagingclamping devicecompris- ing: two jaw members having opposing gripping sur faces; a threaded bolt having one end with a handlefor rotating the bolt, the bolt being rotatably connected to a first ofthe jaw members; and quick engagement means connected to a second of the jaw members and being selectively engagable with ordisengagablefrom the bolt, the engagement means having a pairofhalfnutmemberswithop- posing semi-cylindrical recesses having female threads on opposite sides ofthe bolt, meansfor normally biasing the half nut members towards each other so the female threads engage the bolt and rotation ofthe bolt moves the gripping surfaces together, first cam means between the half nut members for moving the half nut members apart so the female threads disengage from the bolt when the first cam means is in one position, and second cam means having at ieast one part rotatable with the bolt and cooperating with the first cam means for moving the first cam means towards the one position when the bolt is rotated in one direction and for moving the first cam means away from the one position when the bolt is rotated in a direction opposite the one direction so the means for normally biasing moves the half nut members together and the female threads engage the bolt.

2. Aquickengaging clamping device as claimed in Claim 1, wherein the firstcam means comprises a cam member slidably received by both half nut members for movement along an axis and having cam surfaces inclined with respectto the axis slidably engaging inclined cam surfaces of both half nut members.

3. A quick engaging clamping device as claimed in Claim 2, wherein the second cam means includes a stationary cam member and a rotatable cam member which is rotatable with the bolt, slidable along the bolt, and contacts the first cam means, the stationary cam member and the rotatable cam member having mutually contacting helical cam surfaces so rotation of the bolt in the one direction moves the rotatable cam member along the boltto move the first cam means towards the one position.

4. Aquickengaging clamping device as claimed in Claim 2, wherein the rotatable cam member comprises a plurality of segments held together about the bolt by retaining means for normally urging the rotatable cam member to rotate with the bolt, butfor permitting the boltto rotate relative to the rotatable cam member when a torque beyond a predetermined maximum is applied to the rotatable cam member.

5. A quick engaging clamping device as claimed in Claim 4, wherein the stationary cam member has one helical cam surface for each segment of the rotatable cam member, each cam surface of the stationarycam membercurving helicallyfrom afirst point on said each cam surface furthestfrom the first cam means in a direction parallel to the axis to a second point closestto the first cam means in a direction parallel to the axis, the stationary cam member having connecting surfaces between the first and second points of adjacent cam surfaces, the connecting surfaces being parallel to the axis of the first cam member, and cam surfaces of the segments ofthe rotatable cam member curve helicallyfrom a first pointfurthestfrom the first cam means in a direction parallel to the axis to a second point closestto the first cam means in a direction parallel to the axis and adjacent segments have adjacent surfaces which are parallel to the axis of the first cam means.

6. A quick engaging clamping device as claimed in Claim 5, wherein the quick release means further includes stationary stop means for contacting the rotatable cam member and limiting movement of the rotatable cam member towards the first cam means so, as the bolt is rotated in said one direction, the cam surfaces of the segments of the rotatable cam member slide overthe cam surfaces of the stationary cam member until the first point of the cam surface of each segment is nearthe second point of one of the cam surfaces of the stationary cam member.

7. Aquick engaging clamping device as claimed in Claim 6, wherein the rotatable cam member rotates with the bolt when the bolt is rotated in the opposite direction until the surfaces ofthe segments parallel to the axis of the first cam means contacts the connecting surfaces ofthe stationary cam member.

8. Aquickengagingclamping device as claimed in Claim 7, wherein the means for normally biasing the half nut members towards each other biases the first cam means against the rotatable cam member to hold the rotatable cam member against the stati onarycam member.

9. A quick engaging clamping device as claimed in Claim 8, wherein the meansfornormallybiasing comprises at least one spring.

10. Aquickengaging clamping device acclaimed in Claim 9, wherein the retaining means comprises a circular spring clip extending aboutthe segments.

11. Aquickengaging clamping deviceasclaimed in Claim 10,further comprising a segmented sleeve over the bolt between the stationary cam member and the stationary stop means, the segments ofthe rotatable cam means extending about the sleeve.

12. A quick engaging clamping deviceasclaimed in Claim 2, wherein the inclined surfaces are inclined away from the second cam means.

13. Aquickengaging clamping device as claimed in Claim 1, wherein the bolt and the half nut members have threads with adjacent surfaces inclined away from the one end ofthe bolt.

14. A quick engaging clamping devicesubstanti ally as hereinbefore described with reference to eitherofthe embodiments illustrated in the accompanying drawings.