GB2132478A

GB2132478A - Castor

Info

Publication number: GB2132478A
Application number: GB8236255A
Authority: GB
Inventors: Stafford Thomas Screen
Original assignee: British Castors Ltd
Current assignee: British Castors Ltd
Priority date: 1982-12-21
Filing date: 1982-12-21
Publication date: 1984-07-11
Also published as: GB2132478B

Abstract

A twin-wheeled castor has a brake lever (28) pivoted on a part of the body (18) which lies between the wheels. A control rod (14) extends upwardly from one end of the brake lever through a hollow mounting spindle (25) of the castor. An opposite end portion of the lever carries a brake shoe which engages internal surfaces of peripheral walls of the wheels. <IMAGE>

Description

SPECIFICATION Castor One aspect of this invention relates to a castor having a pair of wheels mounted on a body and a brake element which can be moved into engagement with the wheels to impede rotation of the wheels relative to the body.

According to a first aspect of the invention, there is provided a castor comprising a body, a pair of wheels mounted on a part of the body which lies between the wheels for rotation relative to the body about a rolling axis, a lever disposed between the wheels and pivotally mounted on the body, a brake element on the lever, the brake element being engageable with an internal surface of a peripheral wall of one or each of the wheels, a hollow spindle mounted on the body for swivelling relative thereto about a swivelling axis which is generally upright in use, is perpendicular to the rolling axis and is off-set from the rolling axis, and a control element which extends from the lever through the spindle and is adapted to pull towards the spindle a portion of the lever remote from the brake element.

With this arrangement, the brake element, lever and at least an adjacent part of the control element can be concealed from view in normal use of the castor by the body and wheels.

Furthermore, the effectiveness of the braking action is not affected by changes in the condition of the external surfaces of the peripheral walls of the wheels.

According to a further aspect of the invention, a mobile article is provided with at least one castor according to the first aspect of the invention and the control element of that castor is connected with a control lever mounted on the article at a position remote from the wheels of the castor.

An example of a castor in accordance with the invention, in combination with a mobile article, will now be described with reference to the accompanying drawing wherein: Figure 1 shows diagrammatically a perspective view of a trolley; and Figure 2 shows diagrammatically a crosssection through a castor of the trolley.

The trolley illustrated in Figure 1 is of the kind used by pedestrians for transporting goods, particularly in self-service stores. The trolley comprises a frame with a transverse handlebar 10, a container 11 for the goods to be transported and four castors supporting the trolley on the ground. In the particular example illustrated, two of the castors, the castors 12 and 13 at the rear of the trolley, incorporate brakes and the two castors at the front of the trolley are unbraked.

The castors 12 and 1 3 have respective control elements 14 and 1 5 connected by a common Bowden cable 1 6 with a brake lever 17 pivotally mounted on the handlebar 10. A user of the trolley can establish tension in the control elements 14 and 1 5 by drawing a free end portion of the lever 1 7 towards the handlebar. If required, separate brake levers could be provided for the castors 12 and 13.

The castors 12 and 1 3 are identical with each other and accordingly only the castor 12 will be described. As shown in Figure 2, this castor comprises a body 18 and a pair of wheels 19 and 20 mounted in a known manner on a part of the body which extends between them to rotate relative to the body about a rolling axis 21. The wheels are hollow and have respective peripheral walls 23 which engage a floor surface when the trolley is in use. On the internal surface of each peripheral wall 23, there is provided a lining 24.

There is formed in the castor body 18 an opening of generally cylindrical form in which there is received a lower end portion of a hollow spindle 25. A portion of the spindle 25 which protrudes above the body is secured in a known manner to the frame of the trolley. The spindle is retained in the body by means of a pin 26 which extends horizontally through the body and engages in a peripheral groove in the spindle. The body and pin 26 are free to rotate relative to the spindle about a swivelling axis 27 which is generally upright in use.

A brake lever 28 is disposed in the gap between the wheels 1 9 and 20 at a position generally below that of the body 10. One end portion of the lever carries a brake shoe 29. The opposite end portion of the lever lies directly below a lower end portion of the spindle 25.

Between its end portions, the lever is pivotally mounted on the body for movement relative thereto about an axis parallel to the rolling axis 21.

The brake shoe 29 extends into the interior of both of the wheels 19 and 20 and can, by rocking of the lever relative to the body, be engaged with the linings of both wheels concurrently.

Preferably, the linings are formed of steel and at least the surface of the shoe which is presented towards the linings comprises bonded fibrous material as used in the brake shoes of motor vehicles. The surface of the brake shoe presented towards the linings has a curvature corresponding to that of the linings.

The control element 14 extends downwardly through the spindle 25 and through an opening in an end portion of the lever 28 remote from the shoe 29. The control element is connected with the lever in a manner which permits unlimited swivelling of the lever relative to the control element about the swivelling axis 27 but which enables the control element to draw the adjacent end portion of the lever upwardly towards the spindle 25, thereby rocking the brake shoe 29 into engagement with the linings of the wheels.

The connection between the control element and the lever 28 permits limited rocking of the lever on its pivot relative to the control element.

The control element 14 may be a cable or similar flexible element throughout its length.

Alternatively, a part of the control element which passes through the spindle may be in the form of a relatively rigid rod. It will be noted that the force transmitted by each of the control elements 14 and 15 tends to draw together components of the castor concerned and does not tend to expel the spindle 25 from the body 18.

It will be noted that, in the particular example described, the control elements 14 and 1 5 pass around guides 30 and 31 fixed on the frame of the trolley. It will be appreciated that there is no significant restriction to positioning of the brake lever 17, since that lever can be connected by flexible elements with the castors 12 and 13 and the flexible elements are required only to transmit tensile force to the castors.

The braking force exerted by the brake shoe 29 on the wheels of each castor can be steplessly varied by the user. The lever 28 may be mounted on the body in such a manner that it can rock slightly relative to the body about an axis perpendicular to the rolling axis 21. This ensures that equal forces are exerted on the two wheels by the shoe 29.

Claims

1. A castor comprising a body, a pair of wheels mounted on a part of the body which lies between the wheels for rotation relative to the body about a rolling axis, a lever disposed between the wheels and pivotally mounted on the body, a brake element on the lever, the brake element being engageable with an internal surface of a peripheral wall of one or each of the wheels, a hollow spindle mounted on the body for swivelling relative thereto about a swivelling axis which is generally upright in use, is perpendicular to the rolling axis and is off-set from the rolling axis, and a control element which extends from the lever through the spindle and is adapted to pull towards the spindle a portion of the lever remote from the brake element.

2. A castor according to Claim 1 wherein the lever is connected with the control element in a manner which permits swivelling of the lever relative to the control element about the swivelling axis.

3. A castor according to Claim 1 or Claim 2 wherein each wheel has on an internal face of a peripheral wall a lining and the brake element is engageable with the linings of both wheels concurrently.

4. A mobile article provided with at least one castor according to any preceding claim, wherein the control element of the one castor is connected with a control lever mounted on the article at a position remote from the wheels of the castor.

5. An article according to Claim 4 wherein the control element is or includes a cable or like flexible element.

6. A castor substantially as herein described with reference to and as shown in the accompanying drawing.

7. A trolley substantially as herein described with reference to and as shown in the accompanying drawing.

8. Any novel feature or novel combination of features disciosed herein and/or shown in the accompanying drawing.