GB2110792A - Universal joints - Google Patents

Abstract

A universal transmission joint has a transmission assembly comprising two identical half-knuckles (1, 2) angularly adjustable with respect to one another and operatively coupled together by a crosshead (3), the assembly being mounted within two half-bearings (4) enclosed in a tubular casing (5) the ends of which are turned in to provide a secure assembly and one end of which is adapted to exert pressure on an annular detent (6) partially housed in a circular groove (4a) in the side face of one of the half-bearings (4). <IMAGE>

Description

SPECIFICATION Hooke's type transmission joint This invention relates to Hooke's type transmission joints.

The invention provides a Hooke's joint which is designed to replace the known cardan joints and, in a simple straightforward and economic way, to provide an angularly adjustable assembly having a single point of articulation and permitting rotational movement to be transmitted in any position thereof and at the same speed and in the same direction as it is received from a driving unit.

In view of its simple construction the joint in question can have many different uses e.g.

in controls of all types in which there is a need for angles and bends for transmitting gyratory movement around obstacles situated in one and the same plane and which in the majority of cases, necessitate more than a universal joint. In accordance with the invention, the transmission of forces is achieved using only three parts, two of which are identical, which parts are coupled together inside two half bearings enclosed in a tubular casing. One of the two identical parts is adapted to receive the force while the other is adapted to transmit it, each of the parts being able to function at different angles with respect to the geometrical axis of the assembly, variations being possible in any sense, up to a maximum of 40 .

Another advantage of the invention is that the ends of the drive receiving and transmitting members are perfectly free and therefore, without restriction concerning their connection to driving and driven units. It is obvious that depending on the torque and speed of the gyratory movement to be transmitted, it is possible to make the joint in different sizes and even from different materials, which may range from treated steels as required for high speeds, steels which have undergone moulding, forging, machining, sintering, etc., for average speeds and plastics materials intended for low speeds.To sum up, the universal joint which is the subject of the invention has virtually universal application and may be used with the same efficiency to transmit rotary movement to a wheel of a motor vehicle or to operate the mechanism for raising a blind, an awning, a garage door or a window control at an elevated level, where bends and angles are involved.

For easier understanding of the invention and solely by way of example, one form of joint is shown in the accompanying drawing in which: Figure 1 shows in side view and longitudinal section, a universal joint according to the invention, in which the input and output shafts are aligned with each other; Figure 2 shows the joint of Fig. 1 during bending.

Figure 3 shows in elevation and in section, an exploded view of the various components of the joint; Figure 4 is a view in the direction of the arrow "A" Fig. 3; Figure 5 is a view in the direction of the arrow "B" in Fig. 3; Figure 6 is a view in the direction of the arrow "C" in Fig. 3; Figure 7 is a perspective view illustrating the physical form of the cross-head shown in Fig. 6; and Figure 8 shows in lateral and sectional views, a bridle or clasp, the use of wich is optional, depending on the relationship between driving and driven units at the input and output ends of the transmission.

From the drawing, it can be seen that the joint of the invention essentially comprises two identical half knuckles 1 and 2, each of which has a semi-cylindrical recess 1 a, 2a which, during assembly, are arranged facing each other in interesting planes, with each housing the corresponding part of a crosshead 3.

This cross-head 3 (as can be seen from Fig.

7) consists of two half-cylinders extending in planes which intersect at 90 . Each of these half-cylinders matches the shape of the corresponding one of the recesses 1 a, 2a in the half knuckles 1, 2 and is made to fit within the corresponding half-knuckle, so that the half-knuckles, when assembled, have their recesses likewise extending in intersecting planes so that the cross-head 3 forming the core of the double joint, serves as a support for the half-knuckles which permits them to perform angular movements in planes which intersect at 90 .

These angular movements are those which ensure operation of the universal joint when its input and output axes are not in alignment with each other.

Each half-knuckle 1, 2 is extended by a bush 1 b, 2b for input and/or output transmission and these bushes may vary in form according to the application of the joint assembly. A spherical zone 1 c, 2c of the head of each half-knuckle is seated within a spherical bearing 4, which during assembly is seated astride both half-knuckles and held in position by a tubular casing 5, the edges of which are laterally cramped to ensure permanent assembly.One of these edges exerts pressure on an annular catch 6 which is partially housed in a circular groove 4a in the side face of the bearing 4, in order to retain the parts in any position of adjustment In the embodiment shown, the bushes Ib, 2b each have a cylindrical surface with a tangential groove to receive a clasp 7, shown in Fig. 8, which can be secured thereto by a nut and bolt 8 and constitutes one of the various expedients which may be employed to transmit gyratory movement. On the other hand, the casing 5 may be provided with suitable means for attachment to a fixed support when this is necessitated by the connection of the universal joint in a specific form of transmission system.

In the embodiment described, the transmission of movement is carried out by the crosshead 3 through contact of the side surfaces of its half-cylinders with the side walls of the recesses 1 a, 2a of the half-knuckles, while angular variation in planes at 90 are achieved through engagement of the curved surfaces of said semi-cylindrical parts with the bottom of the recesses 1 a, 2a of the aforesaid half-knuckles, resulting in an improvement in the performance of the functions required of any Hooke's type universal transmission joint.

Variations in the size, shape and materials employed may be made without departing from the scope of the appended claims.

Claims (5)

1. A Hooke's type universal transmission joint in which the transmission of torque is carried out by only three parts, two of which are identical, which parts are coupled together within two half-bearings enclosed in a tubular casing, the edges of which are laterally cramped to ensure a permanent fit and one of said edges exerting pressure on an annular detent which is partially housed in a circular groove in the side face of one of the two halfbearings.

2. A joint according to Claim 1, characterised in that the joint comprises two identical half-knuckles, each of which has a semi-cylindrical recess which, during assembly, is arranged opposite and at an angle of 90 with respect to the other, and houses the corresponding part of a cross-head which is shaped to form two half-cylinders, the circumferential planes of which intersect at 90 and each of which conforms to the shape of the recess in the half-knuckle in which it is fitted, so ensuring that during assembly the planes of the recess in said half-knuckles continue to intersect, enabling the core of the double joint, constituted by said cross-head, to serve as a support for the half-knuckles so that they can perform angular variations in planes which intersect at 90 , and ensure operation of the universal joint when its input and output shafts are not aligned with one another.

3. A joint in accordance with any preceding claim, characterised in that each halfknuckle is extended by a bush for reception and/or transmission of movement and is formed with a spherical head which is seated within a matching spherical bearing which, during assembly, straddles the spherical head of the other half-knuckle, the two halves being held in position by a tubular casing, the edges of which are laterally cramped to ensure a permanent fit and one of which edges exerts pressure against an annular catch which is partially housed in a circular groove in the side face of one of the bearings to secure the casing which, in turn, may be provided with external means of fixing it to a fixed support when it is necessary for the universal joint to be coupled in a specific form of transmission system.

4. A joint in accordance with any preceding claim, characterised in that the cross-head ensures transmission of torque through contact of its half-cylinders with the side walls of the recesses in the half-knuckles and angular variations in planes up to 90 by engagement of the curved surfaces of said half-cylinders with the bottoms of the recesses in said halfknuckles.

5. A Hooke's type universal transmission joint, substantially as hereinbefore described with reference to and as shown in the accompanying drawing.