Crimping and Cutting Tool

This invention relates to a crimping and cutting tool and especially to a crimping tool used for the securing of a wire by crimping to a circuit-board in which the wire once it is passed through the board is compressed or pinched to secure it to the board prior to electrical connections being made, generally by soldering.

According to the present invention we provide a crimping and cutting tool comprising a pair of relatively moveable jaws, means for closing said jaws in use to crimp a wire therebetween to form a crimping gap and a moveable cutting blade that wipes the said gap.

In use one such crimping tool closes the jaws about a wire therebetween to form a crimping gap and the cutting blade then wipes the said gap to sever the crimp per se in the said wire where the thickness of the wire is much reduced by the crimp.

In a preferred construction of a crimping and cutting tool the jaws and the blade move orthogonally to each other and the blade is constrained during its wiping and cutting action in a groove within the jaws. Part of said grooves is in each jaw and substantially symmetrical of the centre line of the jaws, said centre line being substantially co-incident with the centre of a wire between the jaws. The crimping tool of the invention is generally a hand tool.

The invention will be more fully understood from the following description given by way of example only in relation to the figures of the accompanying drawing in which:

FIG. 1 is a side elevation of a hand crimping and cutting tool.

FIG. 2 is an enlarged view, of the underside of one jaw of the tool of FIG. 1, shown in third angle orthographic projection.

FIG. 3 is an enlarged view, of inter alia the cutting blade of the tool of FIG. 1 shown in 3rd angle orthographic projection.

FIGS. 4A.sub.1, 4A.sub.11, 4B.sub.1, 4B.sub.11, 4C.sub.1, 4C.sub.11 are enlarged sequential views showing the jaws and cutting blade of the tool of FIG. 1 in action; FIGS. 4A.sub.11, 4B.sub.11, 4C.sub.11 being side views of FIGS. 4A.sub.1, 4B.sub.1, 4C.sub.1 with one jaw removed.

FIG. 5 is a view of an alternative jaw and cutting blade assembly.

Referring now specifically to the several figures of the drawings.

In FIG. 1 a hand crimping and cutting tool is seen to comprise a housing 10 terminated at one end by a connection 11 for a pneumatic hose 12. Pivoted to the housing at 13.sub.1 is an operating handle grip 13.sub.2 that actuates a pneumatic valve shown in part at V.sub.1. The handle grip 13.sub.2 may be rotated about axis A.sub.1 A.sub.2 by virtue of a sealed spigot not shown that co-operates, by a groove not shown, with opposed pins P.sub.1 P.sub.2, to suit the manual dexterity of the operator. Once air pressure is applied for the working of the tool the position of the handle is locked by said air pressure on the rotating parts. Inside the housing is a piston 14 co-operating with a helical return spring 15. The piston has a tapered end 14A shown in dotted lines in FIG. 1 that acts upon inclined surfaces 17.sub.5.sbsb.1, 17.sub.5.sbsb.11 of two jaws (to be described below) and receives centrally within itself piston abutment member 16.sub.3 of a cutting blade 16.sub.1 (FIG. 3); only the cutting blade 16.sub.1 being visible in FIG. 1. Two jaws, a left-hand jaw 17L and a right-hand jaw 17R are each pivoted individually at 17L.sub.1, 17R.sub.1 in the housing 10 and are brought together by the interpenetration of the piston 14.

In FIG. 2 the right-hand jaw 17R is shown more clearly. It is made of steel or some other strong material and has the form shown with a pivot hole at 17.sub.2 and a groove at 17.sub.3 which is in effect a half groove since it co-operates with a similar half groove in the complementary jaw 17L. It is along this groove that the cutting blade 16.sub.1 slides to wipe for example small gap g1 assuming a wire is crimped therebetween and to cut across a crimped wire therebetween. The jaw has a working tapered surface 17.sub.4 which co-operates with a plunger 16.sub.2 (FIG. 3). In FIG. 3 the cutting blade 16.sub.1 is seen to be the end part of the plunger 16.sub.2 which terminates at that end that co-operates with the piston 14 in a piston abutment member 16.sub.3. The modus-operandi of the crimping tool of FIGS. 1, 2 and 3 is shown in FIGS. 4A.sub.1 to FIG. 4C.sub.11 inclusive. A board B has a wire W of a resistor R or other component fed through it. The wire is accepted by the jaws 17L, 17R which when closed by actuation of handle grip 13.sub.2 crimp the wire W at W.sub.1 (FIG. 4B.sub.11) and secure it to the board B. The movement of plunger 16.sub.2 (moving in the direction of arrow A3 FIG. 1) then crops the wire to a predetermined length.

It will be clear from FIG. 1 and FIGS. 4A.sub.1 to 4C.sub.11 inclusive that the cutting blade 16.sub.1 moves in action orthogonally in respect of the closing action of jaws 17L, 17R as indicated by the orthogonal double headed arrows X and Y in FIG. 4C.sub.1 where arrow X shows the opening and closing action of the jaws and the arrow Y the reciprocatory action of the cutting blade 16.sub.1 and plunger 16.sub.2 ; as shown the line of reciprocation is along Y and is normal to the closing or opening action X of the jaws.

It is also to be noted that jaws 17L, 17R are substantially symmetrical of centre line A.sub.1 A.sub.2 of FIG. 1.

Cutting blade 16.sub.1 is forced by the action of piston 14 in the direction of arrow A3 (FIG. 1) and the lower arrow Y of FIG. 4C.sub.1 to slide in groove 17.sub.3 (FIG. 4C.sub.11) across the top of the crimp W1 to cut the wire W at W2 and part it from the crimp W1. The cutting blade 16.sub.1 then returns (upper arrow Y) under the action of return spring 15 once the air pressure is reduced and the jaws 17L, 17R then open ready for further action.

In FIG. 5 two jaws 18L, 18R co-operate in a head 19. Jaw 18R is fixed to the head at 18R.sub.1, 18R.sub.2. Jaw 18L (shown outside the head for convenience of description) is in use pivoted at 18L.sub.1 in head 19 via pivot hole 18L.sub.2. The jaw 18L is forced by any suitable means in a direction indicated by arrow A4 to close the jaws 18L, 18R.

A spring member 20 is fixed to jaw 18L at 18L.sub.3 and as the jaws 18L, 18R meet so the spring member is made to extend itself and so cuts a crimped wire between the said jaws 18L, 18R.

It is to be understood that the crimping and cutting tool of the invention may be actuated solely by hand via suitable linkages or similar means.

It is to be further understood from a consideration of FIG. 4C.sub.11 that the blade 16.sub.1 may, with but a small modification, cut the wire in the crimp W1 per se the blade moving in a groove in the end of the jaws where the thickness of the wire is much reduced by the crimp.