Patent Publication Number: US-6658966-B2

Title: Work bench including a vise

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This is a divisional application of Ser. No. 09/707,300 filed Nov. 7, 2000 entitled Work Bench Including a Vice now U.S. Pat. No. 6,415,683 issued on Jul. 9, 2002. 
    
    
     FIELD OF THE INVENTION 
     The invention relates to portable work benches or tables which include an integral clamping table or vise. More particularly, the present invention relates to a work table with a clamping table or vise where the vise may be operated with one hand. 
     BACKGROUND OF THE INVENTION 
     Carpenters, woodworkers and handymen which work with wood as well as other materials, often need a work bench or table which may be utilized to hold workpieces. Ordinarily, these work benches include a vise which clamps portions of the table top together to secure the workpiece on the table. One such device is that of the assignee of the present invention which is sold under the WORKMATE™ trademark. These tables are versatile, provide for secure clamping, are compact and are convertible to dual height positions. 
     The work bench ordinarily includes two vise screws with handles on each one. The vise screws, via the handles, are operated by the user with the user using both hands. While a user may utilize one hand, the user must rotate both handles in order to clamp a workpiece between the clamping table members. Accordingly, it is desirable to utilize one hand to crank both of the vise screws so that clamping of the workpiece may be accomplished by the user using only one hand. By enabling cranking of the vise to clamp the workpiece with one hand, the user is capable of holding the workpiece in place with his other hand. Also, it is desirable that the vise clamp irregular objects while turning the vise screws with one hand. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is an object of the present invention to provide an improved vise for a work bench which enables the vise to be tightened down utilizing one hand. 
     In accordance with one aspect of the invention, a work bench comprises a frame; a table surface on the frame, with the table surface including at least two members; one of which is movably coupled with the frame to enable clamping of a workpiece between the two table surface members. A drive mechanism moves the table members with respect to one another. The drive mechanism includes two screws coupled with one of the members. The two screws are spaced from one another to move the table member upon rotation of the screws. A sprocket is coupled with each screw. A transmission belt or chain is coupled with the sprocket to drive the screws together. At least one handle is coupled with one of the screws to rotate the screws. At least one clutch is coupled with at least one screw to limit clamping pressures on the workpiece. The clutch enables rotation of one screw with respect to the other screw so that irregular workpieces may be clamped between the table members and clamping of the workpiece may be accomplished by rotation of the handle by one hand of the operator. The clutch is self-actuating. The clutch includes a spring and a detent removably coupled within slots in a hub of the sprocket. Also, both screws may include a clutch. Further, each screw may include a handle. One of the handles has a different configuration than the other to identify to the user that clamping of the table surfaces may be accomplished by rotation of only one handle to drive both screws. 
     In accordance with a second embodiment, a work bench includes a frame; a table surface on the frame, with the table surface including at least two members; one of which is movably coupled with the frame to enable clamping of a workpiece between the two table surface members. A drive mechanism moves the table members with respect to one another. The drive mechanism includes two screws coupled with one of the members. The two screws are spaced from one another to move the table member upon rotation of the screws. A sprocket is coupled with each screw. A transmission belt or chain is coupled with the sprocket to drive the screws together. At least one handle is coupled with one of the screws to rotate the screws. At least one clutch is coupled with at least one screw to limit clamping pressures on the workpiece. The clutch enables rotation of one screw with respect to the other screw so that irregular workpieces may be clamped between the table members and clamping of the workpiece may be accomplished by rotation of the handle by one hand of the operator. A guard covers the transmission belt or chain. The guard is coupled with the frame. The guard includes at least one tensioning member unitarily formed with and extending from the guard. The guard includes at least one alignment member to maintain alignment of the belt or chain to the sprocket. A biasing member is associated with the belt or chain to automatically adjust to changes in the belt or chain length to take up slack and provide positive belt or chain tension. The biasing member may be a helical spring. Further, the guard may include two tensioning members as well as two pairs of alignment members, each pair sandwiching a tension member. 
     In accordance with a third aspect of the invention, a work bench comprises a frame; a table surface on the frame, with the table surface including at least two members; one of which is movably coupled with the frame to enable clamping of a workpiece between the two table surface members. A drive mechanism moves the table members with respect to one another. The drive mechanism includes two screws coupled with one of the members. The two screws are spaced from one another to move the table member upon rotation of the screws. A sprocket is coupled with each screw. A transmission belt or chain is coupled with the sprocket to drive the screws together. At least one handle is coupled with one of the screws to rotate the screws. At least one clutch is coupled with at least one screw to limit clamping pressures on the workpiece. The clutch enables rotation of one screw with respect to the other screw so that irregular workpieces may be clamped between the table members and clamping of the workpiece may be accomplished by rotation of the handle by one hand of the operator. The handle includes a hub, a straight portion extending from the hub, a curved portion extending from the straight portion, and a knob extending from the curved portion. The knob enables rotation of the handle. The curved portion has a truncated U-shape with one end coupled with the straight portion and the knob extending from the other end. The hub has a desired height as well does the straight portion which is less than that of the hub. The curved portion has a height greater than the hub. An end of the curved portion and a side of the straight portion are continuous forming a planar side portion of the handle. A connecting member extends from the hub and is unitary with the straight portion and a portion of the curved portion. The handle may be injected molded from a plastic material. 
     In accordance with a fourth aspect of the invention, a guard for a work bench drive transmission comprises a first wall, at least one second wall extending substantially perpendicular to the first wall, and at least one guide extending from the first wall. The guide extends transverse to the direction of travel of the transmission belt or chain. Preferably, a second guide extends from the first wall. Preferably, two parallel spaced second walls extend from the first wall. An alignment member extends from the first wall. Preferably, the alignment member is stamped into the first wall and two alignment members sandwich each guide member. Also, a second wall includes a biasing member to provide positive belt or chain tension. The first or second walls include cut-outs to secure the helical spring biasing member to the guard. 
     In accordance with a fifth aspect of the invention, a handle for operating a movable work bench comprises a hub, a straight portion extending from the hub, and a curved portion extending from the straight portion. A knob extends from the curved portion to enable rotation of the handle. The curved portion has a truncated U-shape with one end coupled with the straight portion and the knob extending from the other end. The hub has a desired height, as well does the straight portion, which is less than the height of the hub. Also, the curved portion has a height greater than the hub. Also, one end of the curved portion and a side of the straight portion are continuous forming a planar side portion of the handle. A connecting member extends between the hub, straight and curved portions, and is unitary with the three. The handle is ordinarily molded from a plastic material. 
     In accordance with a sixth aspect of the invention, a belt or chain drive transmission for a work bench comprises two screws adapted for coupling with a member to be moved against another member to provide clamping. A sprocket is coupled with each of the screws. A transmission belt or chain is coupled with the sprockets. At least one handle is coupled with one of the screws to rotate the screws. At least one clutch is coupled with at least one screw to limit clamping pressures on a workpiece. The clutch enables rotation of both screws, one with respect to the other which is being directly rotated. The clutch is self-actuating and includes a spring and a detent coupled with a slot in a hub of the sprocket. Preferably, each screw includes a clutch and each screw includes a handle. Also, one of the handles has a different configuration which identifies to the user that only one handle may be rotated to drive both the screws. Also, each screw includes a stop to position the spring with respect to the sprocket. 
     With respect to a seventh aspect of the invention, a work bench includes a frame; a table surface on the frame, with the table surface including at least two members; one of which is movably coupled with the frame to enable clamping of a workpiece between the two table surface members. A drive mechanism moves the table members with respect to one another. The drive mechanism includes two screws coupled with one of the members. The two screws are spaced from one another to move the table member upon rotation of the screws. A sprocket is coupled with each screw. A transmission belt or chain is coupled with the sprocket to drive the screws together. At least one handle is coupled with one of the screws to rotate the screws. At least one clutch is coupled with at least one screw to limit clamping pressures on the workpiece. The clutch enables rotation of one screw with respect to the other screw so that irregular workpieces may be clamped between the table members and clamping of the workpiece may be accomplished by rotation of the handle by one hand of the operator. A guard covers the transmission belt or chain. The guard is coupled with the frame. The guard includes at least one tensioning member unitarily formed with and extending from the guard. The guard includes at least one alignment member to maintain alignment of the belt or chain to the sprocket. A biasing member is associated with the belt or chain to automatically adjust to changes in the belt or chain length to take up slack and provide positive belt or chain tension. The biasing member may be a helical spring. Further, the guard may include two tensioning members as well as two pairs of alignment members, each pair sandwiching a tension member. The handle includes a hub, a straight portion extending from the hub, a curved portion extending from the straight portion, and a knob extending from the curved portion. The knob enables rotation of the handle. The curved portion has a truncated U-shape with one end coupled with the straight portion and the knob extending from the other end. The hub has a desired height as does the straight portion, which is less than that of the hub. The curved portion has a height greater than the hub. An end of the curved portion and a side of the straight portion are continuous to form a planar side portion of the handle. A connecting member extends from the hub and is unitary with the straight portion and a portion of the curved portion. The handle may be injected molded from a plastic material. 
     Additional objects and advantages of the invention will be apparent from the detailed description of the preferred embodiment, and the appended claims and accompanying drawings, or may be learned by practice of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate one embodiment of the present invention and together, with the description, serve to explain the principles of the invention. In the drawings, the same reference numerals indicate the same parts. 
     FIG. 1 is a perspective view of a work bench top in accordance with the present invention. 
     FIG. 2 is a side elevation view of the work bench with the top of FIG.  1 . 
     FIG. 3 is an exploded perspective view of FIG.  1 . 
     FIG. 4 is a cross-section view of FIG. 1 along line  4 — 4  thereof. 
     FIG. 5 is a perspective partially in cross-section view of a portion of the transmission drive of the present invention. 
     FIG. 6 is an enlarged perspective view of a portion of the drive. 
     FIG. 7 is a perspective view of the handle without the knob in accordance with the present invention. 
     FIG. 8 is a cross-section view of FIG. 7 along line  8 — 8  thereof. 
     FIG. 9 is a cross-section view of FIG. 7 along line  9 — 9  thereof. 
     FIG. 10 is an enlarged cross-section view of FIG. 1 along line  10 — 10  thereof. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The preferred embodiment of the present invention is a work bench which is identified with the reference numeral  10 . The work bench includes a frame structure  12  which includes a base  14 , four foldable legs  16 , two upright H supports  18  which extend from the base  16 , and brackets  20  at the other end of the supports  18 . The work bench  22  is generally formed from two members  24  and  26  which are coupled with the brackets  20 . 
     The brackets  20  are hollow and include elongated slots  21  which enable movement of the front table  24  with respect to the brackets  20 . Also, the brackets include apertures  23  to enable the second table portion  26  to be stationarily locked onto the brackets  20 . An additional slot  25  is formed in the side of the brackets  20  to enable the belt  56  to pass into the brackets  20  and be coupled with the sprockets  50 . 
     Two screws  30  are positioned within the brackets  20 . The screws include a threaded portion  32  which includes a threaded pivot nut  34  which in turn, via a block  36 , is coupled with the front moving member  24  of the work bench  22 . Also, the screws  30  includes a smooth shank portion  38  which includes a portion which extends out beyond the bracket  20  as seen in FIG.  1 . The smooth shank portion  38  includes a stop  40  as well as apertures  44  and  46 . 
     Sprockets  50  are slidably positioned onto the smooth shank portion  38  of the screws  30 . The sprocket  50 , as shown, has projecting members  52  which extend into apertures  54  of the belt  56 . However, if a chain is used, the projections may be substituted for recesses or the like. The sprocket  50  includes a hub  58  which includes slots or detents  60 . The slots  60  are adapted to couple with a detent pin  62  which passes through aperture  44  of the screw  30 . 
     A helical spring  64  is positioned on the smooth shank portion  38  abutting the stop  40  and the sprocket  50 . The spring  64  along with the detent pin  62 , sprocket  50  and sprocket slots  60  act as a clutch which limits the pressure which can be applied onto the workpiece. The slot or detent  60  in the sprocket enables transmission of light torques necessary to overcome friction to move the first member  24  providing one hand operation. At high clamping torques, the pin  62  disengages from the sprocket detent or slot  60  and compresses the clutch spring  64 . When unclamping the workpiece, the clutch automatically engages the pin  62  via the sprocket detent  60  to once again allow one handed operation. The clutch  70  could be incorporated on both screws or a single clutch may be provided. In the case of a single clutch, the other sprocket will be securely pinned to the vise screw. Preferably, each of the screws  30  includes a clutch  70  as described above. 
     A guard  80  is positioned over the transmission belt or chain  56 . The guard  80  includes a first wall  82  and at least one second wall  84 , preferably two, which are perpendicular to the first wall  82  forming an overall U-shape and define a channel  85 . The guard  80  includes two guides  86  stamped in and cut out of the first wall  82 . The guides  86  extend substantially perpendicular to the first wall  80  into the channel  85 . The guides  86  are substantially parallel with the second wall  82  and apply tension on the leading  55  side of the belt  56 . The guides  86  help to tension the belt or chain as it moves during rotation of the screws  30 . Also, the guides  86  extend from the wall  82  transverse to the direction of travel of the belt  56 . The guard  80  spans the length of the belt  56  and is secured with the brackets  22  which, in turn, provides additional stability for the frame  12 . 
     Two embossed alignment members  90 ,  92  sandwich the guide  86 . The alignment members  90 ,  92  are stamped into the first wall  82  of the guard  80 . The alignment members  90 ,  92  help to maintain the belt  56  or chain onto the sprockets  50  during the clamping modes. 
     A biasing member  96  is secured to the second wall  82  to automatically adjust for changes in belt length and to take up slack in the belt  56 . The biasing member  96  is a helical spring which is secured on cut-outs  98 ,  99  in the guard  80 . The spring  96  always provides for positive belt  56  or chain tension. The spring  96  is positioned under the belt  56  and tensions both the leading  55  and trailing  57  sides of the belt  56 . 
     Each screw includes a handle  100  and  110 . The handle  100  includes a hub  102 , a handle arm  104  and a knob  106 . The handle  110  includes a hub  112 , a straight portion  114 , a curved portion  116  and a knob  118 . The hub  112  has a desired height which is larger than the straight portion  114 , but less than the curved portion  116 . The curved portion  116  has an overall truncated U-shape. Also, a connecting member  120  extends between the hub  112 , straight portion  114 , and curved portion  116 . The handle  110  provides a visual indication to the user that the work bench clamping system may be rotated with one hand. Also, the hub  112  includes an aperture  122  which enables a pin  124  to pass there-through to secure the handle on the screw  30  through the aperture  46 . Likewise, the handle  100  includes an aperture and a pin to secure it on the screw  30 . 
     The work bench vise of the present invention is ordinarily operated as follows. One of the handles  100 ,  110  is rotated which, in turn, rotates either one of the screws  30 . The rotation of the screw  30  rotates the sprocket  50  and via belt  56  rotates the other screw  30  via its sprocket  50 . Thus, both of the screws  30  rotate at the same time, ordinarily, synchronously. As the user is utilizing one hand to rotate both screws  50 , the user can use his other hand to hold the workpiece in between the two table members  24 ,  26 . As the table members  24 ,  26  contact the workpiece, and especially if the workpiece has an irregular shape, the front table member  24  will contact the workpiece and the sprocket  50  will compress against the spring  64  and move away from the pin  62 , thus engaging the clutch  70 . If an irregular shaped workpiece is between the table portions, then one of the screws  30  will not rotate due to the clutching effect while the other will continue to rotate to clamp on the irregular shape of the workpiece. Once the workpiece is initially clamped and not over tightened, the individual screws can be shored up to give a firm grip onto the workpiece. 
     While the above detailed description describes the preferred embodiment of the present invention, the invention is susceptible to modification, variation, and alteration without deviating from the scope and fair meaning of the subjoined claims.