GB2302835A - C clamp - Google Patents

Abstract

A C-clamp has a generally C-shaped frame 10 and a fixed jaw 11 disposed in the front end of the frame 10. A flange (12) has rectangular shaped recess 13 disposed at the rear end of the frame 10 which cooperates with a square hole 22 at the center of a holding seat 20. A fixed handle 23 which has a groove to receive a driving handle 24 connected to the holding seat 20. A square spindle 30 is inserted through a square hole 231 of the fixed handle 23 and the square hole 22 of the holding seat 20. A spring 31 and a pushing plate 32 which has a square hole 321 passes over the spindle 30 so that the spring 31 and the plate 32 are blocked by the holding seat 20. A flange 241 disposed on the upper end of the driving handle 24 pushes the pushing plate 32 forwardly when the driving handle is moved towards the fixed handle. The spindle may have a hexagonal cross-section (30' fig 3).

Description

TITLE C CLAMP BACKGROUND OF THE INVENTION The invention relates to a screw clamp such as a C-clamp. More particulary, the invention relates to a C-clamp with a square or hexagonal spindle.

A conventional C-clamp has a threaded rod which is slowly forward to a predetermined position to clamp an article. However, the forward motion of the threaded rod is very slow. Another conventional C-clamp applies a round rod to replace the threaded rod. However, the round rod is easily sliced or loosened while a machine is bumped or vibrated so that the article cannot be clamped tightly.

SUMMARY OF THE INVENTION An object of the invention is to provide a C-clamp which can clamp an article tightly.

Another object of the invention is to provide a Cclamp which is easily assembled.

Accordingly, a C-clamp has a generally C-shaped frame and a fixed jaw disposed in the front end of the frame. A Connecting end and an adjacent rectangular shaped recess are disposed at the rear end of the frame. A square hole is formed at the center of the holding seat. A fixed handle which has a groove to receive a driving handle connects the holding seat. A hole on the driving handle and two corresponding holes on the fixed handle are passed through by a pin so that the two handles are fastened together. A square hole is formed on the fixed handle. A square spindle is inserted through the square hole of the fixed handle and the square hole of the holding seat. A-spring and a pushing plate which has a square hole passes through the spindle so that the spring and the plate are blocked by the holding seat.The flange which is disposed on the upper end of the driving handle pushes the pushing plate forwardly.

BRIEF DESCRIPTION ÒF THE DRAWINGS FIG. 1 is a perspective exploded view of a C-clamp of a preferred embodiment in accordance with the invention; FIG. 2 is a perspective assembly view of FIG. 1; FIG. 2A is a sectional view taken along line 2A-2A of FIG.2; FIG. 3 is a perspective exploded view of a C-clamp of another preferred embodiment in accordance with the invention; FIG. 4 is a perspective assembly view of FIG. 3; FIG. 4A is a sectional view taken along line 4A-4A in FIG.4; FIG. 5 illustrates a schematic view of CO welding of the fixed jaw in FIG. 1; FIG. 6 illustrates a schematic view of spot welding of the fixed jaw in FIG. 1; and FIG. 7 is a perspective exploded view of the fixed jaw in FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION Referring to Figs. 1, 2 and 2A, a C-clamp contains a generally C-shaped frame 10 and a fixed jaw 11 disposed in the front end of the frame 10. A connecting end 12 and an adjacent rectangular shaped recess 13 are disposed at the rear end of the frame 10.

A rectangular shaped recess 21 which is- formed on the lobe in front of the holding seat 20 matches the rectangular shaped recess 13 to form a square passage.

A square hole 22 is formed at the center of the holding seat 20. A fixed handle 23 which has a groove to receive a driving handle 24 connects the holding seat 20. A hole on the handle 24 and two corresponding holes on the handle 23 are passed through by a pin P so that the two handles 23 and 24 are fastened together. A square hole 231 is formed on the handle 23. A square spindle 30 is inserted in the square hole 231, the square hole 22 and the square passage which is formed by the recesses 13 and 21. A spring 31 and a pushing plate 32 which has a square hole 321 passes through the spindle 30 so that the spring 31 and the plate 32 are blocked by the holding seat 20. The flange 241 which is disposed on the upper end of the driving handle 24 pushes the pushing plate 32 forwardly. Thus the spindle 30 is moved forwardly.The spindle 30 and the plate 32 are not perpendicular to each other while the spindle 30 moves forwardly. A generally L-shaped plate 25 is disposed on the upper back portion of the handle 23. A through hole 251 is formed on the end of the plate 25 in order to receive an upper end of the braking plate 33. A square hole 331 is formed on the plate 33 in order to receive the spindle 30. A spring 34 which passes through the spindle 30 is blocked between the back of the handle 23 and the plate 33. When the spindle 30 moves forwardly, the plate 33 is skew so that the spindle 30 is blocked by the hole 331. Thus the spindle 30 cannot move rearwardly. When the driving handle 24 is released, the spindle 30 can passes the square hole 321 easily. The plate 33 will not block the motion of the spindle 30.

Referring to Figs. 3, 4 and 4A, a second preferred embodiment is illustrated. A C-clamp contains a generally C-shaped frame 10' and a fixed jaw 11' disposed in the front end of the frame 10'. A connecting end 12' which has two fixed fins 122' disposed at its back is disposed at the rear end of the frame 10'. A hexagonal shaped recess 121' which is formed on the connecting end 12' receives the spindle 30'. Each fin 122' has a hole 123'. A driving handle 24' which has a groove to receive a fixed handle 23' has two holes to be inserted by two corresponding pins P'. The handle 23' has two holes 26' in front portion to match the holes 123' on the corresponding fins 122'.

Two pins P' pass through the holes 26' on the handle 23 and the holes 123' on the fins 122' in order to fasten the C-shaped frame 10' and the fixed handle 23' together. The front portion of the handle 23' is inserted between the fins 122' and positoined by the fins 122'. The driving handle 24' has two holes 242' to match the corresponding holes 222' and 223' on the fixed handle 23'. Two pins 24' pass the corresponding holes 242' and 222' or 223' to fasten the twp handles 23' and 24' together. The spindle 30' passes the hexagonal holes 121', 221' and 322'. The spring 31' and the pushing plate 32' are disposed in the handle 23'.

The pushing plate 32' has a hexagonal hole 322'. The hexagonal hole 221' is formed at the front portion of the handle 23'. A lobe 25' is disposed on the upper rear portion of the handle 23'. A spring 34' and a braking plate 33' with a hexagonal hole 332' pass through the rear portion of the spindle 30'. The upper portion of the braking plate 33' is hooked by the lobe 25'. The spring 34' is restricted between the braking plate 33' and the back of the handle 23'. The periphery of the hexagonal holes 221', 322' and 332' provide friction force and pushing force for the spindle 30'.

Fig. 5 illustrates the CO welding between the fixed jaw 11 and the C-shaped frame 10. Fig. 6 illustrates the spot welding between the fixed jaw 11 and the C-shaped frame 10. Fig. 7 illustrates the combination of the jaw 11 and the C-shaped frame 10. A gap between two lobes 111 of the jaw 11 receives the Cshaped frame 10. Each lobe 111 has a hloe 112 to match the hole on the front portion of the C-shaped frame 10.

A screw P fastens the lobes 111 and the C-shaped frame 10 together.

Claims (8)

WHAT IS CLAIMED IS:

1. A C-clamp comprising: a generally C-shaped frame; a fixed jaw disposed in front end of said frame; a connecting end and an adjacent rectangular shaped recess disposed at a rear end of said frame; a holding seat connecting a front portion of a fixed handle; a square hole formed at a center of said holding seat; a fixed handle which has a groove to receive a driving handle connecting said holding seat; a driving handle being fastened to said fixed handle; a square spindle being inserted through a square hole of said fixed handle and said square hole of said holding seat; a spring and a pushing plate which has a square hole passing through said spindle so that said spring and said pushing plate are blocked by said holding seat; a flange which is disposed on the upper end of said driving handle pushing said pushing plate forwardly;; a generally L-shaped plate disposed on the upper back portion of said fixed handle; a through hole formed on the end of said L-shaped plate to receive an upper end of said braking plate; a braking plate having an upper portion to be blocked by said L-shaped plate; a square hole formed on said braking plate to receive said spindle; a second spring which passes through said spindle is blocked between a back portion of said fixed handle and said braking plate.

2. A C-clamp comprising: a generally C-shaped frame; a fixed jaw disposed in the front end of said frame; a connecting end which has two fixed fins disposed at a back portion thereon being disposed at the rear end of said frame; a hexangonal recess formed on said connecting end; a driving handle and a fixed handle being fastened together; a front portion of said fixed handle being inserted between said fins and positoined by said fins; a spring and a pushing plate being disposed in said fixed handle; said pushing plate has a hexagonal hole to receive said spindle; a lobe being disposed on the upper rear portion of said fixed handle; a second spring and a braking plate with a hexagonal hole passing through the rear portion of said spindle; an upper portion of said braking plate being hooked by said lobe.

3. A C-clamp substantially as herein described with reference to the accompanying drawings.

Amendments to the claims have been filed as follows 1. A C-clamp comprising: a generally C-shaped frame which includes a fixed jaw disposed at a front end of said frame, a movable jaw mounted on a spindle and movable, as a result of axial movement of said spindle, towards and away from the fixed jaw, said frame having a rear end to which a handle assembly is connected, said handle assembly comprising a fixed handle for holding the C-clamp and a movable handle pivotable relative to the fixed handle for effecting movement of the spindle and hence of the movable jaw relative to the fixed jaw, said movable handle being arranged to engage a pushing plate which is formed with a hole through which the spindle passes, said pushing plate being acted on by a first spring which surrounds the spindle such that, as said movable handle is pivoted relative to the fixed handle to effect advancing movement of the spindle, said first spring is compressed so that, when the movable handle is released, the pushing plate is displaced rearwardly relative to the spindle, rearward movement of the spindle under the action of said first spring normally being prevented by means of a braking plate which is formed with a hole through which the spindle passes, said braking plate being acted on by a second spring which surrounds the spindle and acts between the fixed handle and the braking plate, characterised by the provision of a separately formed connecting member interposed between the rear end of the C-shaped frame and the fixed handle, said connecting member being formed with a hole of noncircular cross-section through which the spindle passes, said spindle being of corresponding cross-section to the hole in the connecting member, and said first spring acting between the connecting member and the pushing plate.

2. A C-clamp as claimed in Claim 1, in which the holes in the connecting member, the pushing plate and the braking plate are of square cross-section and the spindle is of corresponding square cross-section.

3. A C-clamp as claimed in either of the preceding claims, in which the movable handle is provided at its upper end with a flange which is arranged to engage the pushing plate to move it forwardly on pivotal movement of the movable handle.

4. A C-clamp as claimed in any one of the preceding claims, in which a generally L-shaped plate is disposed on the upper back portion of the fixed handle and provides a pivot mounting for the braking plate permitting pivotal movement of the braking plate relative to the fixed handle.

5 A C-clamp as claimed in Claim 2, in which the fixed handle is formed with a square hole through which the square spindle passes.

6. A C-clamp as claimed in any one of the preceding claims, substantially as hereinbefore described with reference to and as shown in Figures 1 and 2 of the accompanying drawings.

7. A C-clamp as claimed in Claim 6, in which the fixed jaw is substantially as hereinbefore described with reference to and as shown in Figure 5, or Figure 6, or Figure 7 of the accompanying drawings.

8. A C-clamp having any one or more of the new and useful features of the C-clamp shown in Figures 3 and 4 of the accompanying drawings.