Patent Publication Number: US-11642759-B1

Title: Workpiece clamp assembly for machining and cutting

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to clamp assembly. More particularly, the present invention is generally directed to a clamp assembly for holding work pieces of varying shapes and sizes for cutting, milling, drilling, tapping, boring, or other purposes in a fabrication environment. 
     2. State of the Art 
     In the manufacturing field, there are times when small or irregularly shaped parts are difficult to hold during fabrication. Conventionally, part specific specialized fixtures need to be produced in order to hold workpieces. 
     For example, U.S. Pat. No. 3,105,330 to Grage discloses a large solid block fixture adapted to hold flat-sided stock for grinders. 
     U.S. Pat. No. 3,982,739 to Maes discloses a portable vise which can clamp sections of pipe, structural tubing, or solid bar. 
     U.S. Pat. No. 3,982,740 to Gutman discloses a clamp device used in conjunction with an existing vice, which maintains a workpiece in fixed relationship with the vice. 
     U.S. Pat. No. 4,340,211 to Chiappetti discloses an adjustable V-block clamping devise that is intended to hold longer workpieces exclusively and is not conducive to holding small work pieces in varying positions. 
     U.S. Pat. No. 6,158,728 to Smith discloses a fixture with a clamping arm and a block for holding a workpiece. The block is specifically adapted for being received in a T-slot of a machine table. The fixture has limited application on machine tables that do not have T-slots. 
     U.S. Pat. No. 6,247,690 to Wolf discloses a V-block style clamping tool capable of securing small workpieces to be held for precision fabrication. 
     However, none of the references cited above provide a means of holding irregularly shaped parts of varying lengths, widths, and thicknesses. In addition, the prior art designs tend to be adapted for limited applications, for example, a particular machining operation or type of machine table. Additionally, all of the prior art reference designs can be limited in their portability. 
     Thus, due to the associated time, expense, and practicality, unique fixtures for each part instance may not be prudent for limited production quantities. In addition, fixtures with universal, multi-workpiece size, or multi-situation adaptability may be considered less cost prohibitive. 
     SUMMARY OF THE INVENTION 
     In accord with an aspect of the invention, a universal clamp assembly is provided. A universal clamp assembly includes an elongate tubular base, a clamp arm adjustably secured to the tubular base at a threaded connection and an adjustment screw that adjusts the angle of the clamp arm relative to an upper surface of the base. In an embodiment, the clamp assembly includes the components of an elongate tubular base, a nut plate optionally integrated with the tubular base, a clamp arm adjustably mounted to the tubular base with a fastener assembly, preferably including a threaded shaft, a nut, and a washer, and an adjustment screw for adjusting the angle of the clamp arm relative to an upper surface of the base. 
     The tubular base defines a longitudinal hollow, and a proximal end and a distal end. The distal end is preferably tapered with angled or rounded corners. The base has two longitudinally offset apertures in its upper surface. 
     The nut plate, when provided, is a generally rectangular bar stock sized to inserted into the hollow of the base and seats against an upper inside surface of the base. The nut plate includes a preferably flat upper surface, a distal end, a proximal end, and first and second threaded openings. The nut plate is integrated with the base. 
     The clamp arm is the element by which a clamping force is imparted to the workpiece. The clamping arm has a flat upper surface and a lower surface with a longitudinal channel extending from a distal end and proximally back, e.g., to a midportion. The channel is preferably in the form of a V-notch. The distal end may be tapered with angled or rounded corners. The clamp arm includes two openings: an unthreaded slot and a round threaded hole. 
     The adjustment screw includes a head and a shaft. The head preferably includes a knurled exterior and a hex head opening. The shaft includes machines screw threads and an end. 
     The unthreaded base apertures and the threaded nut-plate openings are aligned along two vertical axes. The unthreaded slot of the clamp arm is aligned with the distal one of the vertical axes. 
     A first end of the threaded shaft is inserted through the elongate slot of the clamp arm, through one of the apertures in the base and is threaded into one of the threaded openings of the nut plate. Depending on the size of the workpiece, the threaded shaft can be inserted into the distal or proximal aperture and threaded opening. The washer and nut are provided onto the second end of the threaded shaft. 
     The shaft of the adjustment screw is threadedly engaged with the second opening of the clamp arm and advanced until the end seats on the upper surface of the base. 
     Adjustment of the nut enlarges or decreases the distance between the clamp arm and the base to stably clamp a workpiece therebetween. The clamp arm can be moved proximally or distally along the base to facilitate securing a workpiece of various sizes. The adjustment screw is adjustable to hold the clamp arm such that the clamping and base surfaces are in a position relative to each other, e.g., parallel or optionally angled. The distal rounded corners on the base and clamp arm permit working a workpiece at such locations without interference from the clamp assembly. 
     In an optional aspect of the clamp assembly, a supplementary clamping block can be secured to the upper surface of the base to facilitate handling and securing of workpieces having elongate cylindrical components. The supplementary clamping block has a first surface which contacts an upper surface of the base, and a second surface provided with a V-groove which faces the opposing channel in the clamping arm. Alternatively, the supplementary clamping block can be received at the interior of the base and be used to secure a workpiece between the V-groove and the nut plate or another interior surface of the base. 
     The proximal end of the base can be secured in standard clamps of numerous machines, including chop saws, band saws, grinders, drill presses, etc., while the workpiece is cut, machined, or otherwise shaped. In view of the above, it is appreciated that the clamp assembly permits stably holding a variety of workpieces for shaping processes. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a perspective view of a universal clamp assembly according to an embodiment of the invention, in a first configuration, and shown securing a thin portion of a workpiece. 
         FIG.  2    is an exploded view of the universal clamp assembly, assembled as shown in  FIG.  1   . 
         FIG.  3    is a longitudinal section view of the assembly of  FIGS.  1  and  2   , shown without workpiece. 
         FIG.  4    is a perspective view of the universal clamp assembly according to an embodiment of the invention, in the first configuration, and shown securing a thick portion of the workpiece. 
         FIG.  5    is a perspective view of the universal clamp assembly according to an embodiment of the invention, in a second configuration, and shown securing a thick portion of the workpiece. 
         FIG.  6    is a perspective view of a universal clamp assembly according to an embodiment of the invention, in the first configuration and provided with an optional clamping block, shown securing a cylindrical portion of workpiece. 
         FIG.  7    is a longitudinal section view of the assembly of  FIG.  6   , shown without the workpiece. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to  FIG.  1   , a universal clamp assembly  10  is shown securing a workpiece  12 . The exemplar workpiece  12  has a thinner plate portion  14 , and a thicker cylindrical portion  16 , but the workpiece can have any of variety of shapes and sizes, and the shape thereof is not an aspect of the invention but rather merely representative of a workpiece suitable for use in the clamp assembly. 
     Referring now to  FIGS.  1  through  3   , the clamp assembly  10  shown includes the components of an elongate tubular base  20 , an optional nut plate  22  integrated with the tubular base, a clamp arm  24  adjustably mounted to the tubular base with a threaded fastener assembly, preferably including a threaded shaft  26 , a nut  28 , and a washer  30 , and an adjustment screw  32  for adjusting the angle of the clamp arm relative to an upper side  36  of the base. 
     The tubular base  20  defines a longitudinal hollow  34 , and in a preferred embodiment has a rectangular cross section thereby defining four sides: upper side  36 , lower side  38 , and first and second lateral sides  40 ,  42 . Each of the sides  34  has outer and inner surfaces, with the respective outer surface denoted a, and the inner surface denoted b. The base  20  has a proximal end  44  for supporting the clamp assembly  10  in a clamp of a machine and a distal end  46  for supporting the workpiece  12 . The distal end  46  may be tapered with angled or rounded corners  48 . The base  20  has two longitudinally off set apertures  50 ,  52  in the upper side  36 . 
     The nut plate  22  is a generally rectangular bar stock inserted into the hollow  34  of the base and integrated with the inside upper side  36   a  of the base, e.g., via welding, brazing, adhesion bonding or other suitable means. The nut plate  22  includes first and second machine-threaded holes  54 ,  56  that are axially aligned with the apertures  50 ,  52  in the upper side  36  along first and second axes, A 1 , A 2 , respectively. Alternatively, the upper side  36  of the base  20  can be made of sufficiently thick material to support machine threads itself about the periphery of the apertures  50 ,  52  without addition of the nut plate; in such case, the nut plate is not required as part of the assembly. However, by keeping the wall thickness of the base  20  relatively thin, the weight of the base  20  is reduced for increased portability and maneuverability, and a larger internal volume of the hollow  34  is provided for securing workpieces therein as well, as discussed below. 
     The clamping arm  24  has an upper surface  60  and a lower surface  62 . The lower surface  62  has a longitudinal channel  64  extending from a distal end  66  and proximally back, e.g., to a midportion. The channel  64  is preferably in the form of a V-groove. The distal end  66  of the clamping arm may be tapered with angled or rounded corners  68 . The clamping arm includes two openings: an unthreaded elongate slot  70  and a round threaded hole  72 . The unthreaded slot  70  of the clamp arm  24  is aligned with the distal vertical axis A 1 . 
     A first end  74  of the threaded shaft  26  is inserted through the slot  70  of the clamping arm  24 , through the first aperture  50  of the base  20  and is threaded through the distal threaded hole  54  of the nut plate  22  until the first end  74  seats against the lower side of the  38  of the base. The washer  30  and nut  28  are provided onto the second end  76  of the threaded shaft  26 . The washer  30  and nut  28  may be separate components, as shown, or integrated as a single and unitary component. For example, the washer  30  may be defined as a lip about the periphery of the nut  28 . (As such, reference to the washer and nut individually, here or in the claims, should not be read to require that such components be separable.) Alternatively, in the fastener assembly it is possible that no washer  30  be used, and the clamping arm be secured with the nut only. The clamping arm  24  can be longitudinally displaced on the slot  70 , to a furthest extended position in which the threaded shaft  26  contacts the proximal end of the slot  70  and the distal end  66  of the clamping arm  24  is substantially even with the distal end  46  of the base  20  ( FIG.  3   ), and to a retracted position in which the threaded shaft  26  contacts the distal end of the slot  70 . The nut can be threaded on the threaded shaft to move the washer against the upper surface of the clamping arm and provide a compression force to prevent additional displacement of the clamping arm on the threaded shaft and relative to the base. This permits application of clamping force to a workpiece located between the clamping arm  24  and the upper side  36  of the base  20 . 
     The adjustment screw  32  includes a head  80  and a shaft  82 . The head  80  preferably includes a knurled exterior and a hex head opening  84 . The shaft  82  includes machines screw threads  86  and an end  88 . The shaft  82  of the adjustment screw  32  is threadedly engaged with the threaded hold  72  of the clamp arm  24  and advanced until the end  88  seats on the outer upper side  36   a  of the base  20 . The adjustment screw  32  is rotatably adjustable to cause the end  88  of the screw to be displaced relative to the threaded hole  72  by a distance that maintains the clamp arm  24  in a parallel configuration relative to the base  20 , or optionally, in an angle orientation. The end  88  can be seated at any location on an arc defined by rotation of the hole  72  about the first axis A 1 . 
     The distal angled corners  48 ,  68  on the base and clamping arm, respectively, permit working a workpiece at such locations without the clamp assembly  10  interfering with the machine or machine tool. 
     Referring now to  FIG.  4   , clamping assembly  10  is shown adjusted into a second configuration (of many) to hold a workpiece. The exemplar workpiece  12  is clamped between the base  20  and the clamping arm  24  to hold the thicker cylindrical portion  16  of the workpiece. The adjustment is quick and easy: the nut  28  is unthreaded along the threaded shaft  26  (relative to the position in  FIG.  1   ) and the nut  28  and washer  30  are displaced to allow a sufficient space between the base  20  and the clamping arm  24  to receive the intended portion  16  of the workpiece  12 . The clamp arm  24  can be longitudinally displaced relative to the threaded shaft  26  along the slot  70 , as necessary. Then the nut  28  is threadedly tightened to force the washer  30  against the upper surface  60  of the clamping arm  24  and thereby stably hold the workpiece. 
     In addition, the threaded shaft  26 , and clamp arm  24  supported thereby, can be anchored proximally along the base  20  at the second aperture  52  and threaded into threaded hole of the nut plate  22 , as shown in  FIG.  5   . This accommodates positioning the workpiece further back along the base to accommodate various machining operations as well as larger workpieces. 
     Turning now to  FIGS.  6  and  7   , in an optional aspect of the clamp assembly  10 , a supplementary clamping block  90  can be attached to the outer upper surface  36   b  of the base  20  to facilitate handling and securing of a workpiece having an elongate cylindrical portion. The supplementary clamping block  90  has a first surface  92  which contacts the outer upper surface  36   b  of the base  20 , and a second surface  94  provided with a V-groove channel  96  which faces the opposing channel  64  in the clamping arm  24 . The clamping block  90  also includes two holes  97 ,  98  spaced apart the distance between the first and second apertures  50 ,  52  in the base. The threaded shaft  26  is inserted through the hole  97  as well as first aperture  50  and secured into threaded aperture  54  of nut plate  22  (or integrated threaded first hole of the base), and a set screw  100  is provided and inserted at second aperture  98  of the clamping block, the second hole  52  of the base, and into the corresponding threaded aperture  56  of the nut plate (or integrated threaded second aperture of the base). An elongate portion of a workpiece  112 , e.g., cylindrical bar stock, polygonal bar stock, or other material, can be inserted between the clamping arm  24  and the clamping block  90 , and the clamping arm  24  can be tightened against the material as described above to secure the material for machining. While the channels  64 ,  96  on the clamping arm  24  and clamping block  90  facilitate engagement and securing of an elongate portion of a workpiece, it is appreciated that, if necessary, an elongate portion can be secured via the channel  64  in the clamping arm  24  and the upper surface  36   b  of the base  20 , even if the clamping block  90  is not utilized or is not provided. 
     In addition, the clamping arm  24  can be secured with the threaded shaft  26  positioned through the second hole  52  of the base  20 , as shown in  FIG.  5   , even when the supplementary clamping block  90  is used. In such situation, the set screw is inserted through the first hole  50  of the base and into the corresponding threaded aperture of the nut plate  22 . 
     According to another aspect of the system, the supplementary clamping block  90  can be received into the hollow  34  of the base  20 . In such manner, the clamping block  90  and be used to secure a workpiece or a portion thereof between the V-groove channel  96  of the clamping block and the nut plate  22  or another interior surface of the base  20 . 
     In all configurations, the proximal end  44  of the base  20  can be secured in standard clamps of numerous machines, including chop saws, band saws, grinders, drill presses, etc., while a workpiece is cut, machined, or otherwise shaped. To facilitate clamping in the standard clamps of such devices, the base  20  is: at least 4 inches in length (between the proximal end  44  and the distal end  46 ), preferably at least 8 inches in length, and more preferably 8 to 16 inches in length; preferably at least 0.5 inch in height (between the upper surface  36  and lower surface  38 ), and more preferably 1 to 2 inches in height to provide safety of use and a suitable hollow; and preferably at least 1.5 inches in width (between the lateral sides  40 ,  42 ), and more preferably 2 to 4 inches in width for sufficient strength. In one preferred embodiment, the base conforms to the dimensions of a 2×4 common stud, which has actual dimensions of 1.5 inches in height by 3.5 inches in width, but in hollow metal form, with a length of 10-12 inches for handling and clamping and preferably with the defined contours at the distal end. The shape of the clamping assembly is adapted to minimize interference with the machine tool during the machining operation, permitting unfettered approach to the workpiece. 
     In view of the above, it is appreciated that the clamp assembly permits stably holding a variety of workpieces for shaping processes. The components of the clamp assembly  10  are preferably made from metal such as steel, iron, or other suitable strong and durable materials. For example, the components can be made of wood for use in a wood shop or of high strength polymers. 
     There have been described and illustrated herein several embodiments of a universal clamping assembly and methods of clamping a workpiece. While embodiments of the invention have been described, it is not intended that the invention be limited thereto, as it is intended that the invention be as broad in scope as the art will allow and that the specification be read likewise. It will therefore be appreciated by those skilled in the art that yet other modifications could be made to the provided invention without deviating from its spirit and scope as claimed.