FR2499447A1 - Closure sprung cable cutting pincers - has cam with ratchet to transmit hand lever force to mobile jaw via elbow jointed lever - Google Patents

Abstract

The cable-cutting pincers uses cutters mounted on coupled jaws, the movement of a movable hand-lever being transmitted to the mobile jaw through a cam and an elbow-jointed lever system. The transmission linkage multiplies the force applied to the hand lever and a ratchet wheel with pawl prevents return hand lever movements, a tensioned spring being used to hold the jaws closed when not in use. A trigger may be used to effect relaxation of the spring, permitting the jaws to be opened for the work to be inserted, and caused the work to be gripped when released. The cam may be in one piece with the ratched wheel, and transmit force to a roller in the lever system. The pincer is mounted between two rigidly connected plates.

Description

Cutting pliers
The invention relates to a cutting pliers, in particular a cable cutting pliers or the like having a large cutting force. To cut cables it is necessary that the clamp has a great force, which is generally obtained from a manual operation. The force exerted by the user must therefore be amplified. On the other hand it is necessary that this pliers of great cutting force does not present a danger for the user.

 The object of the invention is to make a cutting pliers of great cutting force which, in the rest position, has its knives always closed.

 The object of the invention is a cutting pliers, comprising jaws coupled to one another so that one is movable relative to the other, the jaws carrying knives, characterized in that it comprises a cam driven by a ratchet wheel actuating a toggle device, a pawl being mounted on the movable handle so as to drive the ratchet wheel step by step by displacement of the movable handle, the toggle device acting on the movable jaw in the closing direction, the knives being kept closed in the rest position and a device allowing the knives to open for the introduction of the workpiece.

The invention will be clarified by the description which follows of a preferred embodiment of the invention given, by way of nonlimiting example, with reference to the appended drawing in which
Figure 1 is an elevational view of a clamp according to the invention.

 FIG. 2 is a view in longitudinal section along the line II-II of FIG. 1.

 Referring to the drawing, the clamp comprises two series of knives 6, 7 and 8, 9 fixed respectively on a fixed jaw 11 and a movable jaw 12. The fixed jaw 11 has a pivot 12a around which the movable jaw 12, driven by a movable handle 13 via, on the one hand, a cam 15 integral with a ratchet wheel 16, mounted on an axis 16a, in advance step by step by a pawl 17 mounted on an axis 17a of the handle 13 and biased by a spring 17b, and part of a toggle device 20, 21, 22 on which the cam 15 acts.

 A trigger 19 allows the teplaeement of the movable jaw 12 for the introduction of the cutting maple? between the knives. The trigger 19 acts on a link rod LO which moves a movable roller 21 towards the hollow 32 of the cam 15 and causes the opening of the movable jaw 12 by tensioning a tension spring 25 seen from the movable saehoore, which is fixed to the end 20b of the 2Cl link.

 The clamp preferably comprises a double cam 15 which acts on the same roller 21 of the toggle joint formed by two rods G, 22. It suffices for a displacement of 1800 from the cam to carry out the cutting operation. A full revolution of 3600 of the cam allows two cutting operations to be carried out, which halves the number of operations for the movable handle. The links 20, 22 can be double as shown in FIG. 2.

 The cam 15 is integral with one or two toothed wheels (16, 16b) disposed on each side of the cam, with advance pawl 17 and retaining pawl 24. The latter pivots on an axis 2 a and is biased by a spring 24b. The cam 15 advances step by step, always in the same direction when the movable handle 13 which operates on the advance pawl 17 fixed on its lever arm by the axis 17a. The tension spring 25 of the movable jaw keeps the knives in the closed position.

 Maintaining the cable between the knives allows it to be positioned with greater precision before the cutting operation. It also frees one hand from the operator.

 The clamp is produced in the form of two flanges 27, 28 of light alloy or of plastic material trapping the mechanism itself.

 For mounting, the mechanism can be positioned in a flange, then place the second flange on the first and then the two flanges are locked by means of screws or a hook. The assembly is thereby facilitated.

 A flexible rubber ring 30 stops the cam 15 in a fixed position after the end of each half-stroke of the double cam. The clamp has insulating handles 31 fitted on the fixed 33 and movable 13 handles for working under tension.

 The introduction of a cable in the clamp is carried out by pressing the trigger 19 so as to open the jaws. Once the cable is positioned, the trigger is released and the cable is held between the knives of the pliers. The cutting operation is carried out by maneuvering the movable handle 13 with return spring 34 which advances step by step the toothed wheel 16 and consequently the cam 15 which is integral with it. This step-by-step progression of the cam 15 produces a large cutting force.

 The knives are mounted interchangeable and their shape is adapted to the workpiece.

Claims (3)

 1 / Cutting pliers, comprising jaws coupled one to the other  be so that one is movable relative to the other, the jaws carrying knives, characterized in that it  comprises a cam (15) driven by a ratchet wheel (16) action  nant a toggle device (20, 21, 22), a pawl (17) being  mounted on the movable handle (13) so as to drive the wheel to  ratchet step by step by moving the movable handle, the device  with toggle acting on the movable jaw (12) in the direction of the  closing, the knives being kept closed in the rest position  and a device (19) allowing the opening of the knives for the in  production of the workpiece.  2 / Pliers according to claim 1, characterized in that, in  rest position, the movable jaw (12) is kept closed under  the action of a tension spring (25), a trigger (19) allowing  the spacing of the movable jaw for the introduction of the part to  cut between the knives, releasing the trigger ensuring  holding the workpiece between the knives.  3 / Pliers according to claim 1 or 2, characterized in that  that it has a double cam. (15) mounted on the wheel  ratchet (16) and acting on a roller (21) of the toggle joint (20,  22).  between them the mechanism of the clamp.  fact that it comprises two monobloc flanges (27, 28) trapping  LII Forceps according to one of claims 1 to 3, characterized by