GB2286987A

GB2286987A - Single handed slide bar clamp

Info

Publication number: GB2286987A
Application number: GB9423106A
Authority: GB
Inventors: Douglas Lacey
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-03-04
Filing date: 1994-11-16
Publication date: 1995-09-06
Also published as: GB9423106D0

Abstract

A single action slide bar clamp comprises a serrated edged slide bar 1, a first jaw head 4 fixed at one end of the slide bar, a second jaw head 5 having a clamping up screw 6 with a swivel shoe 7 to engage work pieces 8, 9 by means of a handle 10. Spring means 11 extend between the two jaw heads to bias them together. Typically the spring means comprises braided fabric covered elastic cord and may run over pulleys 14, 15 and fixed to the heads at the ends of the cord by screws 17, 18. <IMAGE>

Description

SINGLE HANDED SLIDE BAR CLAMP Technology Field: The Intellectual Property covered by this patent relates to improvements in Slide Bar Clamps (also referred to as "Speed Clamps" and "Speed Clamps") and tnore particularly to a Vibration Proof Single Handed Single Action Slide Bar Speed Clamp. The improvement makes it easier and quicker to temporarily clamp the work pieces using one hand to hold the work pieces and one hand to operate the clamp, then frees both hands to make finer accurate adjustments and aiter tightening up minimising failure of the clamp and accidents from vibration caused by local drilling, routing. hammering and saving.

Background: Slide bar Clamps haTe been widely used be generations of Craftsnien in Carpentry, Boat Building, Civil Engineering, Building and General Engineering g Industries for temporarily holding work pieces in place prior to permanent fastening and operations to work pieces.

Present Day Speed Clanips usually comprise a briglfl drawn steel slide bar having a cast ductile iron fixed jaw head al: one end and a cast ductile iron sliding jaw head containing a two-start acme thread screw with a swivel shoe to address the work pieces. A handle at the other end of the acme screw provides for extra leverage. Both edges of the slide bar are serrated so that when tightening up clamping pressure is applied, friction between the serrations and the siiding jaw head lock and secure the work pieces.

Drawbacks: The present design of Speed Clamps have some major drawbacks: Third band - they require two hands to operate, plus a third hand (or second operative) to hold the work pieces in place until the clamp is fully tightened up; Inaccuracy - even after the clamp is filly tightened up, if there is vibration (due to local drilling or sawing operations), the serrated edges slip loosening tlle clamp sufficiently to allow toe work pieces to mole from its desired position leading to inaccurate work.

Acddcnt Prone - Vibration loosening ofthe clamp caused by (local drilling and sawing operations) causes slipping on the serrated edge, leading not only to failure of the clamp. but accidents which can in some instances be serious.

Object: The object of the present invention is to overcome the above drawbacks in present day Speed Clamps. by providing a Vibration Proof Single Action Single Handed Slide I3ar Speed Clamp allowing:- a) Instant engagement with one hand only, leaving the other hand free to temporarily hold the work pieces in place; b) Both Hands Free to make fine adjustments until the clamp is fully secured; c) Vibration Proof bg dampening out vibration with constant elastic cord pressure against the bar. thus preventing the work pieces from moving from the desired location improving both work accuracy and safety.

Quantum Leap - These features constitute a n1ajor advance in Speed Clamp design.

Prior Art - No Anticipations: A search carried out on the Vorld Patent Index Database has revealed that there are no anticipations of the specific embodiments covered by the claims of this patent.

Pumping Trigger Action Devices: For the record. it must be pointed out that there are now available on the market some single handed quick-grip clamps using a totally difièrent principle to the present invention, They involve multiple pumping of a trigger mechanism for "advance" and "release" of the adjustable jaw. Neither device has the vibration proof feature embodied in the present invention.

Tlle present invention does not involve multiple pumping, nor embody the use of an "advance" and "release" trigger mechanism, and consequently has not been anticipated.

Essential Technical Features - Briefly the improvement embodies a multistrand elastic cord pulleys and anchor arrangement, see Figs. 1 to 5. to pull the sliding jaw towards the fixed jaw. The elastic cord also acts as a vibration damper.

Operation: To use the present invention, the sliding jaw is pushed down the slide bar away from the fixed jaw against the tension of the elastic cord and held open by one hand gripping the moving jaw and slide bar. the fingers acting as a brake. The work pieces are placed in position by the other hand, tlle fixed jaw placed on one side of the work pieces and the braking fingers released, which allows the jaws to spring together and hold the work pieces with reasonable pressure. Both hands are now free to make fine and accurate adjustments to the work pieces after which the clamp is fully tightened Up using the screw handle. As elastic cord pressure is maintained even aiter tightening tip, vibration is damped out, minimising serration slip, and the clamp remains secure.

REFERENCE TO DRAWINGS A specific embodiment of the invention will now be described by way of example with reference to the accompanying drawings, in which: Figure 1 is an illustration of a Vibration Proof, Single Handed. Single Action Slide bar Speed Clamp embodiment of the present invention, in its basic form, showing the spring means that pulls the sliding jaw head towards the fixed jaw head.

Figure 2 is an end view illustration of the same Speed Clamp showing a single longer cord anchored and looped around pulleys on the sliding and the fixed jaws to provide a more constant pulling force between the jaws at different jaw opening gaps, by dividing the gap stretch by the apparent plurality of cords, in this case 3.

Figure 3 is an illustration of the invention, wherein part of the elastic cord, the guide pulleys and one end of the cord securing screw fastening is located on the fixed jaw head and encased by a protection cover to minimise the amount of pulleys and cord running along the slide bar with exposure to manhandling damage.

Figure 4 is an illustration of the same embodiment as figure 3. but viewed from the opposite side.

Figure 5 is an end view illustration of figures 3 and 4. viewed from the slide bar end.

DESCRIPTION According to one preferred embodiment of the present invention. there is provided a Vibration Proof, Single Handed, Single Action Slide bar Speed Clamp, comprising a bright drawn steel slide bar. 1, having serrated edges, 2/3. A cast ductile iron jaw head, 4. is fixed at one eiid of the slide bar, 1 and the slide bar is provided with a sliding cast ductile iron jaw head, 5, containing a clamping up screw, 6, with a swivel shoe, 7, to address the work pieces, 8/9, hinged screw handle, 10, spring means, 11, typically braided fabric covered multi-stranded rubber elastic cord, spring securing means 12., and spring guide means 13. to pull the sliding jaw head, 5, towards the fixed jaw head, 4.

Alternative spring means include constant force springs and helical springs.

The spring securing means includes hook shaped anchoring means, 12h, and screw fastening means, 12.

The spring guide means includes revolving pulleys, 14115, located otl the jaw heads, 4/5, preferably the guide pulleys have a profile to match the elastic cord to enable a single, longer elastic cord, 16 (see figures 2, 3 & 5).

anchored at two ends, 17/18, to loop around the pulleys, 14/15 to provide a more constant pulling force between the jaws, 4 & 5, at different jaw opening gaps.

Alternatively, fixed pulleys are provided instead of revolying pulleys.

Preferably the spring pulling tension is pi-oided to act on the opposite side of the slide bar, 1, to the work pieces, 8/9. This ensures that elastic cord pressure is maintained even after tightening lip, which helps to dampen out vibration and millimise serration slip.

Referring to figures 3. 4 & 5, as an optional enhancement part ofthe elastic cord, 19/20, the guide pulleys, 21/22, and one end of the cord securing screw fastening, 23, is located on the fixed jaw head and is encased by a protection cover, 24, in order to minimise the amount of pulleys and cord running along the slide bar with exposure to manhandling damage.

Claims

CLAIMS:

1. A Vibration Proof, Single Handed, Single Action Slide bar Speed Clamp, comprising a serrated edged steel slide bar havino a cast iron jaw head fixed at one end, a sliding cast iron iaw head containing a clamping up screw with swivel sloe to address the work pieces, screw handle, spring means spring securing means and spring guide means to pull said sliding jaw head towards said fixed jaw head, said spring means including constant force springs, helical springs and braided fabric covered single and mlliti-stlallded rubber elastic cord.

2. A Vibration Proof Single Handed. Single Action Slide bar Speed Clamp as in claim 1, characterised in that said spring securing means includes hook shaped anchoring means and screw fastening means.

3. A Vibration Proof, Single Handed, Single Action Slide bar Speed Clamp as in any one or more of the above claims, characterised in that said spring guide means includes pulleys, including fixed pulleys and revolving pulleys located on said jaw head/s.

4. A Vibration Proof, Single Handed. Single Action Slide bar Speed Clamp as in any one or more of the above claims, characterised in that said guide pulleys have a profile to match said elastic cord to enable a single, longer cord anchored at two ends to loop around said pulleys to provide a more constant pulling force between the jaws at different iaw opening gaps.

5. A Vibration Proof, Single Handed. Single Action Slide bar Speed Clamp as in any one or more of the above claims, characterised in that said spring pulling tension is provided to act on the opposite side of said slide bar to work pieces.

6. A Vibration Proof Single Handed. Single Action Slide bar Speed Clamp as in any one or more of the above claims, characterised in that part of said elastic cord, said guide pulleys and said cord securing means is located on said jaw head, preferably said fixed jaw head, in order to minimise the amount of pulleys and cord running along said slide bar with exposure to man handling damage.

7. A Vibration Proof, Single Handed, Single Action Stide bar Speed Clamp as in claim 6 characterised in that said pulley, cord and securing means is encased by a protection cover.

8. A vibration proof single handed, single action slide bar speed clamp as in any one or more of the above claims where the fixed jaw may be made of cast iron, or formed from the slide bar, or fabricated from steel, or plastic, or steel and plastic.

8. A Vibration Proof Single Handed, Single Action Slide bar Speed Clamp substantially characterised and described herein and with reference to the accompanying drawings.

Amendments to the claims have been filed as follows CLAIMS AMENDMENTS 7. A vibration proof single handed, single action slide bar speed clamp, as in any one or moreof the above claims where one edge is indented so as to form a rack.