Patent Application
20100244348
None
Not Applicable
Not Applicable
Portions of the disclosure of this patent document contain material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure as it appears in the Patent and Trademark Office file or records, but otherwise reserves all copyright rights whatsoever.
The present invention relates to work piece-holding devices and more particularly to C-clamps and even more particularly to a C-clamp with an expeditious adjustment feature.
A C-clamp typically includes a C-frame and a threaded rod to be used in conjunction with the C-frame. The C-frame comprises a pair of oppositely faced arms, namely first and second arms, both connected by an intermediate arm. The ends of the first and the second arms include a seat pad and a threaded hole respectively; the seat pad for providing a gripping surface. The threaded rod is to be received within the threaded hole. One end of the threaded rod includes a shoe member that faces the seat pad of the first arm. The other end of the threaded rod includes a handle. The handle can be rotated in either direction so that the threaded rod can be moved thread-by-thread in a forward or backward direction. Generally, to make use of the C-clamp, a work piece/work pieces are placed between the shoe member and the seat pad. The handle of the threaded rod is rotated until the work piece/work pieces are firmly secured between the seat pad and the shoe member.
C-clamps are generally made of different sizes, ranging from small to large. The operation of the C-clamps, especially the larger ones, is inefficient because the threaded rod has to be rotated so that its entire length has to advance thread-by-thread until the work piece is firmly clamped. This process becomes all the more difficult and strenuous when smaller and/or thinner work pieces are to be clamped. This is because the thinner/smaller the work piece, the more thread-by-thread displacement of the threaded rod required. Thus, more time and efforts is required. To overcome this problem, it is desirable to move or slide the threaded rod rapidly, without having to rotate it, over a considerable distance until the work piece is gripped, and then secure the work piece firmly by rotating the threaded rod. Several C-clamps which facilitate this expeditious movement of the threaded rod are known in the art.
For example, U.S. Pat No. 4,627,604 to Choi discloses a multi-element C-clamp having a work piece-gripping surface at a gripping arm on one end piece, and a gripping element supported from a cooperating gripping arm of a second end piece; the gripping element being advanced as rotated. A spring biased locking lever locks the end pieces in predetermined juxtaposition with respect to one another, with one non-gripping arm of one end piece inserted into a corresponding non-gripping hollow arm of the other end piece. Security latches are provided in the locking levers to ensure against accidental disengagement of end pieces during use. Although the C-clamp and the present invention serve the same purpose, the present invention is structurally distinguishable as it needs to be manipulated at the point where the clamp rod and the C-frame are coupled to achieve the purpose.
U.S. Pat. No. 6,296,241 to Harrison discloses an adjustable C-clamp, which includes a C-shaped frame fitted with parallel bottom and top clamp seats and a clamp cylinder at the top clamp seat. A slotted cylinder is secured in the clamp cylinder by an Allen screw. A clamp rod disposed in the slotted cylinder is fitted with a clamp rod pin. A clamp nut typically attached to one end of the clamp rod faces the bottom clamp seat across the expanse of the clamp frame. The clamp rod pin is designed to slide through a pair of parallel, diametrically-opposed longitudinal cylinder slots in the slotted cylinder to facilitate adjusting the clamp rod in the slotted cylinder and quickly positioning the clamp nut at a selected spacing from the bottom clamp seat. By rotation of the clamp rod in the slotted cylinder, the clamp rod pin is seated in a selected pair of multiple spaced-apart pin slots extending from the respective longitudinal cylinder slots in diametrically opposed relationship with respect to each other. Continued rotation of the clamp rod facilitates threaded extension of the clamp cylinder through the top clamp seat and advancement of the clamp nut against the bottom clamp seat. In another embodiment, the slotted cylinder is omitted and the longitudinal cylinder slots and respective sets of pin slots are provided in the clamp cylinder.
U.S. Pat. No. 5,423,525 to Spainhower discloses a C-clamp comprising a C-shaped body. The body comprises a first end and a second end, the first and the second ends terminating in an anvil and a base respectively. The base includes an opening. Further, the base includes a first member and a second member, both pivotally connected thereon. The first and second members are operative between open and second positions. In the closed position, the first and the second members are joined together to form an aperture that is aligned with the opening in the base; the aperture being internally threaded. In the open position, the first and the second members are tilted sideward in opposite directions whereby the aperture is divided longitudinally. The first and second members are operated between the open and closed position by means of a latch. The C-clamp further comprises a screw which includes a foot and a rod at either end, the rod acting as a handle. The screw is disposed within the opening and the aperture such that the foot and the anvil are oppositely located. The screw can be slid within the opening when the first and the second members are in the open position. However, when the first and the second members are in closed position, the screw needs to be rotated so as to advance it in forward or backward direction. Therefore, to make use of the C-clamp, a work piece is to be placed across the expanse of the C-shaped body and the screw is to be freely pushed until the work piece is gripped in between the foot and the anvil. Then the latch is to be released, so that the first and second members engage in closed position. Subsequently, the screw is rotated until the work piece is tightly clamped.
Although the above references facilitate an expeditious adjustment of the C-clamps, the present invention differs from the above inventions in that the present invention employs a groove and locking device mechanism to secure a clamp rod and facilitate efficient clamping and unclamping of a work piece.
Therefore, it is an objective of the present invention to provide a C-clamp with an expeditious movement/adjustment feature so as to avoid thread-by-thread advancement of the clamp rod for clamping a work piece.
A further object is to provide a means for facilitating expeditious adjustment at the point where the C-frame and the clamp rod are coupled.
Finally, it is an object of the present invention to provide the expeditious adjustment feature by employing a cylinder with a bore, at least one groove, a locking device, and a clamp rod thereby differentiating the present invention from the above references and other related art. These and other objects of the present invention will become better understood with reference to the appended Summary, Description, and Claims.
The present invention is an adjustable C-clamp comprising a clamp rod and a C-frame, which in turn comprises first and second arms. The ends of the first and the second arms comprise a seat pad and hole respectively. The clamp rod is engaged with the C-frame. The clamp rod includes a shoe member at one of its end.
The C-clamp further comprises a cylinder that is to be received within the hole. The cylinder contains a bore and thus, comprises an exterior and interior side. The interior includes at least one groove. At least one end of the groove terminates in a shallow end or another groove that is shallower than the first groove. The interior further comprises a locking device initially located within the groove. The clamp rod is to be disposed within the interior such that the seat pad and the shoe member are oppositely faced. The clamp rod can slide within the interior.
To make use of the C-clamp, the clamp rod is pushed until a work piece is gripped between the shoe member and the seat pad. The clamp rod is then rotated in a first direction so that the locking device moves towards the shallow end of the groove. At this point the clamp rod gets substantially locked within the interior of the cylinder. Further rotation of the clamp rod in the same direction enables a tighter gripping on the work piece due to extension of the cylinder along with the clamp rod thereby producing the desired clamping effect. Rotating the clamp rod in a second direction followed by sliding it backwards disengages the work piece from the C-clamp.
Referring to the drawings, a preferred embodiment of an adjustable C-clamp 100 is illustrated in
Referring to
Referring to
Referring to
Referring to
Alternatively, if there are two shallow ends of groove 410, the rotation of clamp rod 170 in the second direction produces the same locking effect within cylinder 160. Further rotation of clamp rod 170 in the same second direction moves the cylinder 160 in the second direction thread-by-thread. Rotating clamp rod 170 in the first direction brings back the clamp rod 170 to the initial position.
Therefore, to clamp a work piece 900 or a plurality of work pieces as seen in
Referring to
All features disclosed in this specification, including any accompanying claims, abstract, and drawings, may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.
Any element in a claim that does not explicitly state “means for” performing a specified function, or “step for” performing a specific function, is not to be interpreted as a “means” or “step” clause as specified in 35 U.S.C. §112, paragraph 6. In particular, the use of “step of” in the claims herein is not intended to invoke the provisions of 35 U.S.C. §112, paragraph 6.
Although preferred embodiments of the present invention have been shown and described, various modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustration and not limitation.
