Cam action clamp

• US 5,156,508 A
• Filed: 01/09/1991
• Issued: 10/20/1992
• Est. Priority Date: 12/27/1989
• Status: Expired due to Term

• Current Assignee: Grisley, Kenneth M.
• Original Assignee: Grisley, Kenneth M.
• Inventors: Grisley, Kenneth M.
• Primary Examiner(s): Wilson, Neill R.
• Application Number:
  US07/639,499
• Time in Patent Office: 650 Days
• Field of Search: 411/354, 411/355, 411/429, 411/432, 411/916, 411/935, 411/935.1, 269/230, 269/236
• US Class Current: 411/354
• CPC Class Codes: B25B 5/08 using cams
• CPC Class Codes: F16B 2/185 using levers
• CPC Class Codes: Y10S 411/916 Bolt having tension feature

Abstract

A cam action clamp for use against a fixed clamping surface comprising a threaded shaft extending outwardly from the fixed clamping surface and a movable clamping member having a channel therethrough to allow the clamping member to be mounted on the threaded shaft for slidable movement along the shaft. A thrust plate is affixed to the movable clamping member adjacent the channel. A mounting block is threadably mounted on the threaded shaft and a clamping handle is pivotally mounted to the mounting block. The handle is formed as a cam member that abuts the thrust plate. Pivoting the handle causes the cam member to engage the thrust plate to slidably advance the movable clamping member along the threaded shaft toward the fixed clamping surface in order to clamp an article between the surfaces. The mounting block can be rotated along the threaded shaft to vary the distance between the clamping surfaces. The thrust plate can be formed with stepped surfaces that allow the clamping handle to be repositioned to a more convenient angle while still applying the same clamping force. In addition, a shroud member is provided that encloses the threaded shaft to prevent objects, such as a user'"'"' s hand, getting pinched between the shaft and the pivotable clamping handle.

Claims

1. A cam action clamp for use against a fixed clamping surface comprising:

a threaded shaft extending outwardly from said fixed clamping surface;

a movable clamping member having a clamping surface and a channel therethrough to allow said member to be mounted on said threaded shaft for slidable movement along said shaft;

a thrust plate adjacent said movable clamping member adjacent said channel;

coarse adjustment means comprising a mounting block threadably mounted on said threaded shaft;

a clamping handle pivotally mounted to said mounting block for movement between a released and a clamped position, said handle being formed with fine adjustment means comprising a cam member that abuts said thrust plate whereby pivoting said handle causes said cam member to engage said thrust plate to slidably advance said movable clamping member along said threaded shaft toward said fixed clamping surface in order to clamp an article between said clamping surfaces, and whereby said mounting block can be rotated along said threaded shaft to vary the distance between said clamping surfaces;

said thrust plate being formed with means to permit substantially the same clamping force to be exerted at different clamped positions of the clamping handle with respect to said threaded shaft.

2. A cam action clamp as claimed in claim 1 in which said handle comprises a pair of parallel, longitudinal extensions pivotally mounted to opposite sides of said mounting block.

3. A cam action clamp as claimed in claim 1 in which said thrust plate has a circular face to accommodate said cam members of said handle no matter the rotational angle of said mounting block on said threaded shaft.

4. A cam action clamp as claimed in claim 1 in which said cam member is adapted to engage said thrust plate when said clamping handle is pivoted to align essentially parallel to said threaded shaft.

5. A cam action clamp as claimed in claim 1 in which said cam member is adapted to engage said thrust plate when said clamping handle is pivoted to align essentially perpendicular to said threaded shaft.

6. A cam action clamp as claimed in claim 1 in which said means to permit substantially the same clamping force to be exerted comprises a plurality of stepped surfaces formed on the face of said thrust plate for engagement by said cam member whereby said clamping handle can be rotated on said threaded shaft from a first position engaging one of said plurality of stepped surfaces to a second position at a different angle with respect to said threaded shaft, said thrust plate at said second position of said clamping handle being rotated such that said cam member engages a different one of said plurality of stepped surfaces that allows said cam action clamp to exert the same clamping force as when at the first position.

7. A cam action clamp as claimed in claim 6 in which said stepped surfaces are separated by a distance that corresponds to the thread pitch of said threaded stud divided by the number of stepped surfaces.

8. A cam action clamp as claimed in claim 6 in which said clamping handle is formed with paired cam members pivotally mounted to opposite sides of said mounting block and said stepped surfaces are formed in pairs on said thrust plate adapted to be engageable by said paired cam members.

9. A cam action clamp as claimed in claim 8 in which said thrust plate is formed with a central projection adapted to be removably inserted between said paired cam members to releasably connect said thrust plate to said clamping handle.

10. A cam action clamp for use against a fixed clamping surface comprising:

a threaded shaft extending outwardly from said fixed clamping surface;

a movable clamping member having a clamping surface and a channel therethrough to allow said member to be mounted on said threaded shaft for slidable movement along said shaft;

a thrust plate adjacent said movable clamping member adjacent said channel;

coarse adjustment means comprising a mounting block threadably mounted on said threaded shaft;

a clamping handle pivotally mounted to said mounting block, said handle being formed with fine adjustment means comprising a cam member that abuts said thrust plate whereby pivoting said handle causes said cam member to engage said thrust plate to slidably advance said movable clamping member along said threaded shaft toward said fixed clamping surface in order to clamp an article between said clamping surfaces, and whereby said mounting block can be rotated along said threaded shaft to vary the distance between said clamping surfaces; and

a shroud member in the form of an arcuate section enclosing said threaded shaft and adapted to permit pivoting of said handle member past said shaft and prevent objects from becoming caught between said handle and threaded shaft during said pivoting.

11. A cam action clamp as claimed in claim 10 in which said shroud member is formed with a hollow interior that encloses said threaded shaft.

12. A cam action clamp as claimed in claim 10 in which said shroud member is in the form of an arcuate section mounted at its apex to said mounting block, and said clamping handle comprises a grip with attached spaced, parallel arms that extend on either side of said arcuate section and terminate in said cammed members, said arms being pivotally mounted to opposite sides of said mounting block such that said arcuate section passes freely between said spaced, parallel arms when said clamping handle is pivoted.

13. A cam action clamp as claimed in claim 12 in which said shroud member is in the form of an arcuate quarter section pivotally mounted at its apex to said mounting block.

14. A cam action clamp as claimed in claim 13 including co-operating tongue and groove means formed on said spaced, parallel arms and said arcuate section to coordinate pivoting of said arcuate section with respect to said clamping handle.