Patent Application
20070035075
1. Field of Invention
The present invention relates to a vise clamp
2. Related Prior Art
A vise clamp is primarily used in places where a vise cannot be used. For example, in processing planks, a vise clamp can be moved to various positions as desired by a user, but a vise cannot. A C-shaped vise clamp includes a body, a stationary jaw formed on the body, a screw installed on the body, and a movable jaw with a screw hole for receiving the screw. By means of rotating the screw, the movable jaw is moved up and down in order to clamp. For not including a retaining device, the C-shaped vise clamp often looses when subject to vibration. The following steps of the operation are thus affected. Moreover, the movable jaw can only be moved by means of rotating the screw, the speed of clamping is slowed. The smoothness of the operation is affected.
There has been devised a new C-shaped vise clamp including a stationary jaw, a movable jaw installed on the stationary jaw, and a clamping device connected to the movable jaw. The clamping device includes a lever formed with a cam. A ratchet mechanism is provided between the lever and the movable jaw. A contact element is put against the cam. Wishing to clamp a workpiece, a user moves the movable jaw so that the movable jaw reaches the workpiece. The user pivots the lever. The cam pushes the contact element. Thus, vise clamp clamps the workpiece. The ratchet mechanism is supposed to retain the lever and therefore the contact element in position. The pivotal of the lever is faster than the rotation of a screw.
In the foregoing C-shaped vise clamp, the cam formed on the lever is used to clamp; however, it causes an inadequate stroke of the movement of the contact element and therefore an adequate clamping force. The clamping force is particularly inadequate when it is used to clamp an elastic workpiece. Moreover, the abutment of the cam against the contact element affects the position of the contact element so that the contact element may not fully contact a workpiece. Hence, the clamping is not stable. Hence, there is room for improvements.
The present invention is therefore intended to obviate or at least alleviate the problems encountered in prior art.
The primary objective of the present invention is to provide a vise clamp that can provide a large clamping force and be operated stably.
According to the present invention, a vise clamp includes a stationary jaw and a movable jaw put on the stationary jaw. The movable jaw includes an ear formed with ratchets. A lever is formed with two ears connected to the ear of the movable jaw. A pawl is connected to the lever and formed with ratchets for engagement with the ratchets of the movable jaw. Two pinions are connected to the ears of the lever. Two pushers sandwich the pinions, and each includes a slot defined therein and a rack engaged with one of the pinions so that the pushers are moved as the pinions are rotated. A contact element is put against the pushers so that the former can be pushed by means of the latter. The contact element includes two ears sandwiching the pushers. Each of the ears of the contact element defines a slot. A shaft is driven through the ear of the movable jaw, the ears of the lever and the pinions so that they are rotated together with one another. The slots of the pushers and the slots of the contact element receive the shaft in order to allow movement of the pushers and the contact element relative to the shaft.
Other advantages and novel features of the invention will become more apparent from the following detailed description in conjunction with the drawings.
The present invention will be described through detailed illustration of the preferred embodiment referring to the drawings.
Referring to
The movable jaw 20 includes, at an end, an ear 25 to which the clamping device 30 is connected. The ear 25 includes an aperture 26 defined therein and a series of ratchets 27 formed along the periphery of the ear 25. The lever 31 includes, at an end, two ears 32 corresponding to the ear 25 of the movable jaw 20. Each ear 32 defines a non-circular aperture 320. A shaft 33 includes two non-circular ends 34 compliant to the non-circular apertures 320. The shaft 33 is inserted through the aperture 26. The non-circular ends 34 of the shaft 33 are fit in the non-circular apertures 320 of the lever 31. Thus, the lever 31 is connected to the movable jaw 20, and the shaft 33 will be rotated together with the lever 31. Each non-circular end 34 of the shaft 33 is fit in a non-circular aperture 350 defined in a pinion 35. Teeth 351 are formed along the periphery of each pinion 35.
The clamping device 30 includes two pushers 36 provided beyond the pinions 35. Each pusher 36 includes a slot 360 defined therein, a space 361 communicated with the slot 360 and a rack 362 formed on the wall of the space 361. The racks 362 are engaged with the pinions 35 so that the pushers 36 are moved as the pinions 35 are rotated. The contact element 37 includes two ears 370 formed on two sides and located beyond the pushers 36. Each ear 370 defines a slot 371 for receiving the shaft 33. Thus, the contact element 37 can be moved by means of the pushers 36. A pawl 38 is pivotally connected to the lever 31 by means of a pin 39. A spring 380 is put between the pawl 38 and the lever 31. The pawl 38 includes, at an end, ratchets 381 for engagement with the ratchets 27 of the ear 25. Thus, after pivoted, the lever 31 is retained in position by means of the pawl 38.
As discussed above, the vise clamp according to the present invention can provide a large clamping force and be operated stably.
Referring to
The present invention has been described through the detailed illustration of the preferred embodiment. Those skilled in the art can derive variations from the preferred embodiment without departing from the scope of the present invention. Therefore, the preferred embodiment shall not limit the scope of the present invention defined in the claims.
