Patent Application
20130312247
I determined that it would be beneficial for a user to substantially increase the force exerted against a work piece by a c-clamp. This would also mean that less muscular effort would be needed by a user to obtain a satisfactory clamping force while saving energy to operate which could aid the handicapped worker. Also I have designed an automated clamping device that calls for a significantly smaller motor to exert the same clamping force. This will save money and energy for equipment designers.
A clamping or gripping device includes a double threaded drive shaft operating opposable threaded linkage driving members that in turn drive sets of linkages inward toward the clamping direction. As the threaded linkage driving members are driven toward each other, they actuate links that in turn push a clamping or gripping plate upward to clamp material between itself and an opposing facing clamping or gripping surface. As the threaded linkage driving members move closer, the resulting angle of the links becomes steeper, thus increasing the mechanical advantage of the clamping or gripping device, enhancing clamping or gripping forces against an object e.g. a work piece. A beneficial result is a clamping apparatus that requires significantly less muscular energy to operate than a traditional c-clamp that can help the handicapped user. Another beneficial result is that if the same amount of muscular energy is applied to the driveshaft as in connection with a traditional c-clamp, the resulting clamping force is significantly higher, aiding in such operations as shearing and punching.
A preferred embodiment also then permits the linkages to toggle over center and lock the device in place. This is an added safety benefit for the clamp in that the device will resist excessive vibration, or accidental bumping of the driveshaft handle.
Tools of the invention can be configured with multiple embodiments, and can be used for many applications such as holding parts for fabrication, gripping, or even cutting, shearing or punching material. Another application is manual or robotic spot welding. The resulting very high application forces is a substantial benefit for these operations, particularly punching and shearing. For workbench applications it can be used in place of traditional c-clamps to require less effort to clamp parts together that can aid the handicapped. For gripping or lifting applications it can be attached to a gantry or robot arm and operated via a motor to achieve significantly higher clamping or gripping forces when compared to standard screw-drive actuators or grippers. Thus, the double threaded drive shaft and link assembly enables the clamping plate to have a higher resulting force against any fixed opposing surface.
a Is a side elevation of the device, with cover plate removed, and with clamp assembly shown with the clamping plate nearly fully extended. The links are shown at a very steep angle so as to illustrate the higher mechanical advantage of the assembly.
b Is the same side elevation as in
As shown in
As shown in
As shown in
The center guide shaft 11 may not be required in all applications. In fact it may be advantageous to omit the center guide shaft feature in order to gain more adjustability in clamping material at varying angles and varying thicknesses.
Also, the clamping assembly can be configured such that the double threaded driveshaft 1 can be separated into right and left threaded rods that can be independently rotated from opposing ends, either manually or via motors.
In the case of the preferred embodiment, where the threaded linkage driving members are moving toward each other, the links are forced into a steeper angle with respect to the driveshaft's axis. The steeper angle results in corresponding increasing mechanical advantage. This mechanical advantage results in the user being required to exert only a fraction of the amount of tightening torque when compared to similar devices, e.g. c-clamps, with standard single threaded rod actuators. This can benefit users that are physically handicapped.
The double threaded driveshaft 1 can be mounted inside a main clamp housing 7, and cover plate 8 and cover plate screws 9 shown in
The double threaded driveshaft has an optional shaft adapter 17 and manual crank handle 14 attached thereto as shown in
The preferred embodiment also has an opposing clamping member 6 can be optionally attached to an adjustment threaded rod 19 and optional crank handle 14a shown in
Another way of characterizing the embodiment of the invention shown in
The embodiment shown in
Further customization of the clamping or gripping device is easily attainable with the motorized assembly of
A set of attachment points can be added to the main housing of
Sensing elements can be added to the clamping/gripping device to enable part presence detection and clamping and unclamping states.
While the invention has been described in connection with preferred embodiments, the description is not intended to limit the scope of the invention to the particular forms set forth, but on the contrary, it is intended to cover such alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention as indicated by the language of the following claims.
For example, the term “double threaded driveshaft” is intended to cover separate right handed and left handed threaded rods that can be independently rotated from opposing ends, either manually or via motors.
