GB2291586A - A castor - Google Patents
A castor Download PDFInfo
- Publication number
- GB2291586A GB2291586A GB9515168A GB9515168A GB2291586A GB 2291586 A GB2291586 A GB 2291586A GB 9515168 A GB9515168 A GB 9515168A GB 9515168 A GB9515168 A GB 9515168A GB 2291586 A GB2291586 A GB 2291586A
- Authority
- GB
- United Kingdom
- Prior art keywords
- castor
- support member
- mounting member
- recess
- detent
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60B—VEHICLE WHEELS; CASTORS; AXLES FOR WHEELS OR CASTORS; INCREASING WHEEL ADHESION
- B60B33/00—Castors in general; Anti-clogging castors
- B60B33/02—Castors in general; Anti-clogging castors with disengageable swivel action, i.e. comprising a swivel locking mechanism
- B60B33/025—Castors in general; Anti-clogging castors with disengageable swivel action, i.e. comprising a swivel locking mechanism by using form-fit, e.g. front teeth
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60B—VEHICLE WHEELS; CASTORS; AXLES FOR WHEELS OR CASTORS; INCREASING WHEEL ADHESION
- B60B2200/00—Type of product being used or applied
- B60B2200/40—Articles of daily use
- B60B2200/43—Carts
- B60B2200/432—Shopping carts
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60B—VEHICLE WHEELS; CASTORS; AXLES FOR WHEELS OR CASTORS; INCREASING WHEEL ADHESION
- B60B33/00—Castors in general; Anti-clogging castors
- B60B33/0002—Castors in general; Anti-clogging castors assembling to the object, e.g. furniture
- B60B33/0005—Castors in general; Anti-clogging castors assembling to the object, e.g. furniture characterised by mounting method
- B60B33/0007—Castors in general; Anti-clogging castors assembling to the object, e.g. furniture characterised by mounting method by screwing
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60B—VEHICLE WHEELS; CASTORS; AXLES FOR WHEELS OR CASTORS; INCREASING WHEEL ADHESION
- B60B33/00—Castors in general; Anti-clogging castors
- B60B33/0036—Castors in general; Anti-clogging castors characterised by type of wheels
- B60B33/0039—Single wheels
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60B—VEHICLE WHEELS; CASTORS; AXLES FOR WHEELS OR CASTORS; INCREASING WHEEL ADHESION
- B60B33/00—Castors in general; Anti-clogging castors
- B60B33/0047—Castors in general; Anti-clogging castors characterised by details of the rolling axle
- B60B33/0049—Castors in general; Anti-clogging castors characterised by details of the rolling axle the rolling axle being horizontal
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60B—VEHICLE WHEELS; CASTORS; AXLES FOR WHEELS OR CASTORS; INCREASING WHEEL ADHESION
- B60B33/00—Castors in general; Anti-clogging castors
- B60B33/0047—Castors in general; Anti-clogging castors characterised by details of the rolling axle
- B60B33/0057—Castors in general; Anti-clogging castors characterised by details of the rolling axle the rolling axle being offset from swivel axis
Abstract
A castor (10) includes a wheel (3) rotatably mounted on a support member (5). A mounting member (1) is rotationally coupled to the support member (5) and a detent mechanism (6, 7, 8) is mounted between the support member (5) and the mounting member (1) to substantially prevent rotational movement of the support member (5) relative to the mounting member (1) when the rotational force applied between the support member (5) and the mounting member (1) is less than a threshold level. The defent mechanism comprises a ball (7) which is urged into a recess (6) in the rotatable part of the wheel support. Spring bias is provided by a rubber sleeve (9) surrounding the assembly. The ball sits in an aperture (8) in the periphery of the fixed part or mounting member (1). <IMAGE>
Description
"A Castor"
The invention relates to castors and especially castors for trolleys such as shopping trolleys.
A problem with castors, especially when used on trolleys, such as shopping trolleys, is that it is difficult to steer them round corners and bends as the natural tendency of the castor wheel is to go in a straight line when moving.
A number of ideas have been put forward to overcome this problem. However, most have fallen by the wayside due to designs not being user friendly and using complicated steering mechanisms. For example some proposals require levers to operate the mechanism. The latest in this mode has actually been taken on trial by a major shopping chain. This design uses a lever and cable attachments to lock the front wheels during steering.
However, this has the disadvantage that it uses a lever and cables to operate the mechanism and the lever must be operated by the user. It has been found that levers confuse shoppers. Also front wheel locking has the disadvantage of requiring considerable space in order to turn the trolley.
In accordance with the present invention, a castor comprises a wheel rotatably mounted on a support member, a mounting member rotationally coupled to the support member, the mounting member for attaching the castor to an object, and a detent mechanism mounted between the support member and the mounting member to substantially prevent rotational movement of the support member relative to the mounting member when the rotational force applied between the support member and the mounting member is less than a threshold level.
Typically, the detent mechanism substantially prevents rotational movement of the support member relative to the mounting member when the support member is in one orientation with respect to the mounting member.
Preferably, there is only one orientation in which rotation is substantially prevented.
Preferably, the detent mechanism comprises a recess on one of the support member and the mounting member which co-operates with a detent member on the other of the support member and mounting member, the detent member being biassed into the recess. Typically, the detent member may be provided by a spherical member which is captive on the other of the support member and the mounting member.
Preferably, the castor also comprises a spring biassing member to bias the detent member into the recess.
Typically, the biassing member is provided by an elastically compressible material, such as rubber.
Typically, the castor is attached to an object by the mounting member which is rotationally fixed with respect to the object. The biassing member is, preferably, located on the mounting member to bias the detent member and the recess towards each other, when the detent member is aligned with the recess.
In one example, the recess is located on the support member and the detent member is mounted on or within the mounting member. In another example, the recess is located on the mounting member and the detent member is mounted on or within the support member.
Typically, the object may be an item of furniture or a trolley. Preferably, the trolley is a shopping trolley such as the type used in supermarkets. Preferably, two castors according to the invention are provided as the rear wheels of a shopping trolley. The front wheels are conventional castors.
The principle of the invention is that if the rear castor wheels on a trolley are locked in the straight ahead position more leverage can be applied to the front wheels to steer right or left more easily.
However since the rear wheels cannot be locked all of the time (for reasons of manoeuvrability) a system of semi-locking has to be used. In the invention the method devised uses a detent mechanism.
Examples of a castor in accordance with the invention will now be described with reference to the accompanying drawings, in which:
Fig. 1 is an exploded side view of a first example
of a castor;
Fig. 2 is a cross-sectional view through the
castor shown in Fig. 1; and
Fig. 3 is an exploded side view of a second
example of a castor.
Fig. 1 is an exploded side view of a castor 10 which has a wheel 3 with an axle 4 on which the wheel 3 rotates. The axle 4 is mounted between the legs of a
U-shaped support member 5 which has a circular domed section 2 on its upper section. In the domed section 2 a recess 6 is formed with has a radius which substantially corresponds to the radius of a steel or nylon ball 7. A domed cover 1 covers the domed section 2 and has a throughbore 8 in which the spherical ball 7 may be located. A rubber sleeve 9 fits over the domed cover 1 and retains the spherical ball 7 within the recess 8. The resiliency of the rubber sleeve 9 acts to bias the ball 7 into the recess 6 in the domed section 2 of the support member 5.The castor 10 may then be attached to a trolley leg 11 by a bolt 12 which is inserted between the legs of the U-shaped support member 5 and passes through central holes in the domed section 2, domed cover 1 and rubber shroud 9 to secure the castor 10 to the trolley leg 11.
Fig. 2 shows a cross-section through the castor 10 in which it can be seen that when the recess 6 is aligned with aperture 8, the spherical ball 7 sits in the recess 6 and is biassed to this position by the rubber sleeve 9.
In use, the conventional rear wheels of a shopping trolley are replaced by two castors 10 by securing the castors 10 to the rear legs using bolts 12. The castors 10 will be fitted to the shopping trolley such that the ball 7 and aperture 8 in the domed cover are aligned in a forward direction.
Hence, when a force above a threshold force is applied sideways to the trolley the force will overcome the biassing force of the rubber sleeve 9 so that the ball 7 "breaks out" of the recess 6 to enable the domed section 2 to rotate relative to the domed cover 1.
This permits the support 5 to be rotated to change the direction of the wheel 3. When the trolley is directed such that the wheel 3 again points in a forward/backward direction with the recess 6 pointing forwards, the ball 7 will be forced into the recess 6 by the rubber sleeve 9 to relock the rear castor wheels in a forward/backward direction with respect to the trolley.
Fig. 3 shows a second example of the invention in which two wheels 20 (only one shown) are rotationally mounted on an axle 21 which is attached to a support 22. In this example, the support 22 is central and wheels 20 are provided on each side of the support 22. A blind bore 23 extends into the support 22 to accept a vertical axle 24 on which the support 22 rotates.
Attached to the top of the support 22 by screws 25 is a member 26 which has a throughbore 27 and a hole 28 for receiving a nylon or steel ball 7. It is possible that member 26 may be integral with the support 22.
When the vertical axle 24 is inserted through the throughbore 27 into the blind bore 23, a recess 29 in the upper portion of the axle 24 can be aligned with hole 28 in the member 26 such that the ball 7 may engage with the recess 29. A rubber sleeve 30 is placed over the outside of the member 26 and the resiliency of the rubber sleeve acts as a spring biassing mechanism to bias the ball 7 towards the axle 24 and into the recess 29. The castor 40 may be attached to a leg of a shopping trolley by means of a threaded member 31 on the upper end of the axle 24.
As with the castor 10 shown in Figs. 1 and 2, the castor 40 may be used to replace the conventional rear castors of a shopping trolley and operation of the castor 40 is similar to that described above for the castor 10.
It is possible that the rubber sleeves 9, 30 can be varied in thickness to give a degree of adjustment to the force with which the ball is held in the recesses 6, 29 and therefore alter the "break out" force required to move the ball out of the recesses 6, 29.
Similarly, the ball size can be altered to give greater or lesser degrees of resistance, as required.
In both examples of the invention described above and shown in Figs. 1 to 3, the rubber sleeve 30 may be replaced by a resilient plastic sleeve or a steel spring sleeve.
The advantages of the invention are that the castor is only marginally larger than a normal castor and is rubber covered to reduce the likelihood of damage to other objects. No additional levers and cables are required. Other designs are bulky and so are prone to damage. It also has the advantage of being cost effective and easily fitted to existing trolleys.
The castor of the invention when incorporated into a trolley requires no levers, steers easily and when sideways pressure is applied to the trolley, the ahead position is easily overcome and the wheels will turn only to lock again as one moves forward.
Modifications and improvements may be incorporated without departing from the scope of the invention.
Claims (10)
1. A castor comprising a wheel rotatably mounted on a support member, a mounting member rotationally coupled to the support member, the mounting member for attaching the castor to an object, and a detent mechanism mounted between the support member and the mounting member to substantially prevent rotational movement of the support member relative to the mounting member when the rotational force applied between the support member and the mounting member is less than a threshold level.
2. A castor according to Claim 1, wherein the detent mechanism substantially prevents rotational movement of the support member relative to the mounting member when the support member is in one orientation with respect to the mounting member.
3. A castor according to Claim 1 or Claim 2, wherein the detent mechanism comprises a recess on one of the support member and the mounting member which cooperates with a detent member on the other of the support member and the mounting member.
4. A castor according to Claim 3, wherein the detent member is provided by a spherical member which is captive on the other of the support member and the mounting member.
5. A castor according to Claim 3 or Claim 4, further comprising a spring biassing member to bias the detent member into the recess.
6. A castor according to Claim 5, wherein the spring biassing member is provided by an elastically compressible material.
7. A castor according to Claim 5 or Claim 6, wherein the biassing member is located on the mounting member and biasses the detent member towards the recess when the detent member is aligned with the recess.
8. A trolley comprising a castor according to any of the preceding claims.
9. A trolley fitted with castors, wherein the rear castors are castors in accordance with any of Claims 1 to 7.
10. A castor substantially as hereinbefore described with reference to any of the accompanying drawings.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB9515168A GB2291586B (en) | 1994-07-23 | 1995-07-24 | A castor |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB9414903A GB9414903D0 (en) | 1994-07-23 | 1994-07-23 | A castor |
GB9515168A GB2291586B (en) | 1994-07-23 | 1995-07-24 | A castor |
Publications (3)
Publication Number | Publication Date |
---|---|
GB9515168D0 GB9515168D0 (en) | 1995-09-20 |
GB2291586A true GB2291586A (en) | 1996-01-31 |
GB2291586B GB2291586B (en) | 1998-09-16 |
Family
ID=26305332
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB9515168A Expired - Fee Related GB2291586B (en) | 1994-07-23 | 1995-07-24 | A castor |
Country Status (1)
Country | Link |
---|---|
GB (1) | GB2291586B (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2325150A (en) * | 1997-05-13 | 1998-11-18 | Leslie Armstrong | Detachable rolling element, e.g. a castor |
Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2583858A (en) * | 1949-12-10 | 1952-01-29 | Jarvis & Jarvis Inc | Automatic swivel locking caster |
FR2350972A1 (en) * | 1976-05-11 | 1977-12-09 | Marti Paul | Castor wheel assembly with lockable swivel - uses double ball bearing swivel which can be locked by screw action from fixed to moving swivel parts |
US4246677A (en) * | 1979-05-14 | 1981-01-27 | The Colson Company | Cart caster |
WO1994010000A1 (en) * | 1992-10-23 | 1994-05-11 | Stanley John Dibben | Wheel assemblies |
EP0618089A1 (en) * | 1993-03-30 | 1994-10-05 | Guitel-Etienne Mobilor | Castor wheel with locking of steering |
GB2279242A (en) * | 1993-06-14 | 1995-01-04 | James Arthur Watts | "Castor" |
GB2286523A (en) * | 1994-02-22 | 1995-08-23 | Brian Joseph Cunnington | Castors for trolleys |
-
1995
- 1995-07-24 GB GB9515168A patent/GB2291586B/en not_active Expired - Fee Related
Patent Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2583858A (en) * | 1949-12-10 | 1952-01-29 | Jarvis & Jarvis Inc | Automatic swivel locking caster |
FR2350972A1 (en) * | 1976-05-11 | 1977-12-09 | Marti Paul | Castor wheel assembly with lockable swivel - uses double ball bearing swivel which can be locked by screw action from fixed to moving swivel parts |
US4246677A (en) * | 1979-05-14 | 1981-01-27 | The Colson Company | Cart caster |
WO1994010000A1 (en) * | 1992-10-23 | 1994-05-11 | Stanley John Dibben | Wheel assemblies |
EP0618089A1 (en) * | 1993-03-30 | 1994-10-05 | Guitel-Etienne Mobilor | Castor wheel with locking of steering |
GB2279242A (en) * | 1993-06-14 | 1995-01-04 | James Arthur Watts | "Castor" |
GB2286523A (en) * | 1994-02-22 | 1995-08-23 | Brian Joseph Cunnington | Castors for trolleys |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2325150A (en) * | 1997-05-13 | 1998-11-18 | Leslie Armstrong | Detachable rolling element, e.g. a castor |
Also Published As
Publication number | Publication date |
---|---|
GB2291586B (en) | 1998-09-16 |
GB9515168D0 (en) | 1995-09-20 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 20100724 |