GB1567087A

GB1567087A - Torque restricion member for incorporation in a torque-transmitting drive

Info

Publication number: GB1567087A
Application number: GB52647/77A
Authority: GB
Original assignee: BONDIOLI E
Current assignee: BONDIOLI E
Priority date: 1976-12-20
Filing date: 1977-12-19
Publication date: 1980-05-08
Also published as: DE2756809A1; IT1069344B; ES465711A1; DE2756809C2; FR2374556A1; FR2374556B1

Description

(54) A TORQUE RESTRICTION MEMBER FOR INCORPORATION IN A TORQUE-TRANSMITTING DRIVE (71) I, EDI BONDIOLI, an Italian citizen, of Via Gina Bianchi 2, Suzzara, Mantova, Italy, do hereby declare the invention for which I pray that a patent may be granted to me, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to a torque restriction member for incorporation in a torque-transmitting drive.

According to the present invention, there is provided a torque restriction member for incorporation in a torque-transmitting drive, said member comprising a first element arranged for engagement with a shaft of the drive, a second element including a connecting fork, said first and second elements being assembled for relative rotation, and a shear element coupling said first and second elements against relative rotation whereby to permit transmission of torque between said first and second elements, said shear element shearing at transmission of torques above a predetermined torque.

An embodiment of the invention will now be described, by way of example only, with reference to the accompanying diagrammauc drawings, in which: Figure 1 illustrates a longitudinal section of a torque restriction member according to the invention; Figures 2 and 3 illustrates sections taken ond line Il-Il and Ill-Ill of Figure 1; and Figure 4 illustrates, for comparison purposes, part of a conventional universal joint which may be replaced by the torq. restriction member of Figures 1 to 3.

The part of the universal joint shown in Figure 4 comprises a core 1 with a splined bore 3 which receives the shaft to be coupled.

The core 1 is integral with a fork comprising two branches 5. A locking pin 7 serves to releasably lock the shaft with the splined bore 3.

A torque restriction member intended to replace the component shown in Figure 4, is i1ustrated in Figures 1 to 3. In these figures, 10 denotes a core having a splined bore 12 for receiving the shaft. At one side of the core 10 there is provided a seat 14 (see Figure 3) for a locking pin 16 which serves to releasably lock the shaft within the bore 12. On its outer surface, the core 10 is provided with a projecting collar 10A and with an annular seat 18 forming a race for balls 20.

A collar 22, from which two fork branches 22A extend (and which correspond to the branches 5 of the fork shown in Figure 4), is mounted on the core 10 with its end face adjacent an end face of the collar 10A. The collar 22 is provided with an annular seat 24 which faces the annular seat 18 and which likewise forms a race for the balls 20. A radial bore provided in the collar 22 in com munication with the seat 24, receives a lubri cation nipple 26 to enable lubrication of the bearing assembly formed by the balls 20 and the annular seats or races 18, 24. The nipple 26 is removable to permit insertion of the balls into the annular seats via the radial bore in the collar 22. The balls 20 allow relative rotation of the parts 10 and 22 but prevent.

their axial movement.

The core 10 and the collar 22 are each formed respectively with a radial projection 10B and 22B, the two projections being bored to form a through-seat for a shear pin or bolt 30, arranged with its axis parallel to that of the splined bore 12 and thus of the shaft.

The pin or bolt 30 forms a torque-transmitting coupling between the core 10 and collar 22 and is such that it will shear at torques above a specified limit. For smooth operation of the torque restriction member, a hardening treat ment is advantageously provided for the facing end edges of the seats for the pin or bolt 30, as is shown at 32 in Figure 3. This arrangement protects, against deformation, the edges of the seat provided for the pin or bolt 30 on each of the two projections 10B and 22B and ensures a functional coupling which is broken when the pin or bolt 30 shears.

The torque restriction member described can be used in existing drives provided with a component such as that of Figure 4, by simple replacement of the existing component with the described torque restriction member which has the same coupling sizes as the original component. In this way it is possible to introduce, into the drive, a torque restric tion member to protect certain components of the drive, which could otherwise be damaged in the presence of a very high torque.

WHAT I CLAIM IS: 1. A torque restriction member for incor poration in a torque-transmitting drive, said member comprising a first element arranged for engagement with a shaft of the drive, a second element including a connecting fork, said first and second elements being assembled for relative rotation, and a shear element coupling said first and second elements against relative rotation whereby to permit transmis- sicn of torque between said first and second elements, said shear element shearing at transmission of torques above a predetermined torque.

2. A torque restriction member according to claim 1, wherein the shear element com prises a pin or bolt offset with respect to the rotational axis of the member.

3. A torque restriction member according to claim 2, wherein the shear pin or bolt is located in adjacent seats formed in the first and second elements, the seats having adjacent end edge potions which are hardened.

4. A torque restriction member according to any one of claims 1 to 3, wherein the first and second elements are assembled for relative rotation by a set of balls accommodated in annular seats of the two members, said balls allowing relative rotation of said two elements but preventing their relative axial movement.

5. A torque restriction member according to claim 4, wherein an outer one of the first and second elements has a bore leading to its annular seat, the bore serving to feed lubricant to the seats and balls and also to permit introduction of the balls into the seats.

6. A torque restriction member substantially as hereinbefore described with reference to Figures 1 to 3 of the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. a component such as that of Figure 4, by simple replacement of the existing component with the described torque restriction member which has the same coupling sizes as the original component. In this way it is possible to introduce, into the drive, a torque restric tion member to protect certain components of the drive, which could otherwise be damaged in the presence of a very high torque. WHAT I CLAIM IS:

1. A torque restriction member for incor poration in a torque-transmitting drive, said member comprising a first element arranged for engagement with a shaft of the drive, a second element including a connecting fork, said first and second elements being assembled for relative rotation, and a shear element coupling said first and second elements against relative rotation whereby to permit transmis- sicn of torque between said first and second elements, said shear element shearing at transmission of torques above a predetermined torque.