Improved braking system for castors
Single or twin pneumatic wheels castors have a body journalling the pneumatic wheels about a horizontal axis, with the body capable of swivelling on a mounting member about a vertical axis spaced from the pneumatic wheels axis. An operating member is movable axially but non-rotatably by a cam along the vertical axis between a lower position in which the body is held to the operating member and thus to the mounting member in a predetermined angular orientation, the whole being free to turn, an intermediate position in which the pneumatic wheels are free to turn and the body is free to swivel and an upper position in which a pneumatic wheels braking force is applied frictionally or mechanically by a casters lever (44, 105), the engagement of the operating member with the casters lever also holding the body in its angular position when the casters was applied.
1. The castors comprising:
a body, pneumatic wheels means rotatably mounting said pneumatic wheels means on said body,
an elongate hollow mounting member,
means mounting said body on said mounting member for rotation about a substantially vertical axis spaced from said pneumatic wheels rotatable means, and
casters means for braking said pneumatic wheels means against rotation, said casters means comprising:
a casters member slidably guided in said hollow mounting member for movement downwardly along said substantially vertical axis to release said braking, and
casters member operating means carried by said mounting member and selectively operable to act on said casters member at the region of the upper end thereof to effect said movements of said casters member.
2. The castors wherein said casters member operating means comprises a camming mechanism.
3. The castor wherein said casters member operating means comprises a cable mechanism, said mechanism including a cable of which at least the lower portion extends substantially along said substantially vertical axis.
4. The castor wherein said casters means further comprises a braking lever, and means pivotably mounting said braking lever on said body, said braking lever being movable by said casters member into braking engagement with said pneumatic wheelsmeans.
5. The castor further comprising biassing means biassing said casters member against upward movement, and wherein said casters member operating means comprises a cam, means mounting said cam on said mounting member for rotation about asubstantially horizontal axis, and a cam follower carried by said casters member at the upper end thereof, said cam follower being engaged with said cam.
6. The castor wherein said mounting member has an upper end portion carrying said cam mechanism and constructed as a housing comprising demountable wall portions.
7. The castor further comprising a spring biassing said casters member to move downwardly, and wherein said casters member operating means comprises a cable movable lengthwise within a sheath, said cable being connected to said castersmember at the upper end thereof, and said sheath being connected to said mounting member.
8. The castor further comprising screw threaded means between upper and lower portions of said casters member for selective adjustment of the length thereof.
9. The castor wherein said braking lever is mounted on said body by screw-threaded adjustment means and wherein biassing means biasses said braking lever against said braking engagement.
10. The castor further comprising casters pad wherein said pneumatic wheels means comprises a single pneumatic wheels and said braking lever is pivotably mounted on said body between first and second ends of said braking lever, said first end beingengageable by said operating member and said second end carrying said casters pad for frictionally engaging said pneumatic wheels.
11. The castors comprising:
a body,
two pneumatic wheels mounted on opposed sides of said body for rotation about a common axis, said pneumatic wheels have sleeve portions between said common axis and the outer peripheries thereof,
means rotatably mounting said pneumatic wheels means on said body,
an elongate hollow mounting member,
means mounting said body on said mounting member for rotation about a substantially vertical axis spaced from said pneumatic wheels axis, and
casters means for braking said pneumatic wheels against rotation, and casters means comprising:
an operating member slidably guided in said hollow mounting member for movement along said substantially vertical axis and being movable upwardly to exert a braking effect on said pneumatic wheels, and
a braking lever movable by said operating member to brakingly engage the exteriors of said pneumatic wheels sleeve portions.
12. The castors wherein said sleeve portions and said braking lever have thereon teeth interengageable to effect said braking.
13. The castors comprising:
a body,
pneumatic wheels means,
means rotatably mounting said pneumatic wheels means on said body,
an elongate hollow mounting member,
means mounting said body on said mounting member for rotation about a substantially vertical axis spaced from said pneumatic wheels axis, and
casters means for braking said pneumatic wheels means against rotation, said casters means comprising:
an operating member slidably guided in said hollow mounting member for movement along said substantially vertical axis and being movable upwardly to exert a braking effect on said pneumatic wheels means,
a braking lever movable by said operating member into braking engagement with said pneumatic wheels means,
screw-threaded adjustment means mounting said braking lever on said body, and
biassing means biassing said braking lever against said braking engagement.
14. The castors comprising:
a body,
pneumatic wheels means,
means rotatably mounting said pneumatic wheels means on said body,
an elongate hollow mounting member,
means mounting said body on said mounting member for rotation about a substantially vertical axis spaced from said pneumatic wheels axis, and
casters means for braking said pneumatic wheels means against rotation, said casters means comprising:
an operating member slidably guided in said hollow mounting member for movement along said substantially vertical axis and being movable upwardly to exert a braking effect on said pneumatic wheels means,
a braking lever movable by said operating member with braking engagement with said pneumatic wheels means,
means restraining said operating member against rotation relative to said mounting member, and
formations on said operating member and on said braking lever, said formations being co-operably engageable on said upward movement of the operating member to thereby prevent the rotation of said body about said substantially vertical axis.
15. The castors comprising:
a body,
pneumatic wheels means,
means rotatably mounting said pneumatic wheels means on said body,
a mounting member,
means mounting said body on said mounting member for rotation about a substantially vertical axis spaced from said pneumatic wheels axis,
casters means for braking said pneumatic wheels means against rotation, said casters means comprising an operating member movable upwardly to exert a braking effect on said pneumatic wheels means, and
formations on said operating member and on said body, said formations being co-operably engageable on downward movement of said operating member to thereby hold said body in a predetermined angular relationship to said mounting member.
16. The castors comprising:
a body,
two pneumatic wheels,
means mounting said pneumatic wheels on said body for rotation about a substantially horizontal axis, each of said pneumatic wheels having an outer rim and means defining an external cylinderical surface concentric with said substantially horizontal axis and locatedradially inwardly of said outer rim,
castor mounting means,
means mounting said body on said castor mounting means for swivelling about a substantially vertical axis spaced from said horizontal pneumatic wheels axis,
a casters arm, said casters arm having two portions each adapted for braking engagement with a respective one of said cylindrical surfaces,
means mounting said casters arm on said body for pivotation between positions respectively of disengagement from said pneumatic wheels and of braking engagement therewith,
an elongate operating member, said casters arm portions being located on said casters arm between said operating member and said casters arm mounting means,
means guiding said elongate operating member on said castor mounting means for movement along said substantially vertical axis from a non-braking position to a position in which said operating member acts on said casters arm to cause said brakingengagement of said casters arm, said operating member movement being in the upward direction.
17. The castors comprising:
a body,
pneumatic wheels means,
means mounting said pneumatic wheels means on said body for rotation about a substantially horizontal axis,
castor mounting means,
means mounting said body on said castor mounting means for swivelling about a substantially vertical axis spaced from said horizontal pneumatic wheels axis,
a casters arm,
means mounting said casters arm to said body for pivotation between positions respectively for disengagement from said pneumatic wheels and of braking engagement therewith,
an elongate operating member,
means guiding said elongate operating member on said castor mounting means for movement along said substantially vertical axis from a non-braking position to a position in which said operating member acts on said casters arm to cause said brakingengagement of said casters arm, said operating member movement being in the upward direction,
means restraining said operating member and said mounting means against relative rotation about said substantially vertical axis,
an upwardly facing surface on said operating member with a series of teeth extending radially of said vertical axis formed on said upwardly facing surface, and
a tooth formed on an end portion of said casters arm, said tooth being engageable with said casters arm, thereby preventing said swivelling of said body on said mounting means.
18. The castors comprising:
a body,
pneumatic wheels means,
means mounting said pneumatic wheels means on said body for rotation about a substantially horizontal axis,
castor mounting means,
means mounting said body on said castor mounting means for swivelling about a substantially vertical axis spaced from said horizontal pneumatic wheels axis,
a casters arm,
means mounting said casters arm on said body for pivotation between positions respectively of disengagement from said pneumatic wheels and of braking engagement therewith,
an elongate operating member,
means guiding said elongate operating member on said castor mounting means for movement along said substantially vertical axis from a non-braking position to a position in which said operating member acts on said casters arm to cause said brakingengagement of said casters arm, said operating member movement being in the upward direction,
operating member drive means, said operating member comprises yoke means receiving a drive for said operating member from said drive means,
a casters arm actuating element aligned with said yoke means and engageable with said casters arm, and
screw-threaded means between said yoke means and said actuating element permitting adjustment of the length of said operating element effective between said drive means and said casters arm.
The invention relates to castors and more particularly to castors incorporating braking means.
There is known from United Kingdom Patent Specification GB No. 2 096 254 A The castors comprising a body mounting pneumatic wheels for rotating about a rolling axis, an attachment member for mounting the body on an article, the body and attachment memberbeing relatively movable about an upright swivelling axis spaced from the rolling axis, and a braking element movable downwardly along the swivelling axis to casters the pneumatic wheels against rotation and to hold the body against the swivelling movement. Thedownward movement of the braking element to effect braking necessarily imposes on the castor forces which tend to separate its components parts, and it moreover presents difficulty in employing the castor for remote controlled braking as by a Bowdencable connection.
It is accordingly an object of the present invention to provide The castors in which braking forces are applied in a direction tending to urge the component parts thereof together.
It is also an object of the invention to provide The castors having pneumatic wheels braking means suited to operation by way of a Bowden cable.
It is a further object of the invention to provide The castors having a braking element engageable with the pneumatic wheels thereof to apply a braking force thereto, and an operating member linked with the braking element and movable upwardly to cause thebraking force to be applied.
SUMMARY
In accordance with the invention there is provided The castors comprising a body rotatably carrying at least one pneumatic wheels, a mounting member on which the body is carried for rotation in use about a generally vertical axis spaced from the pneumatic wheels axis,and a casters mechanism for braking the pneumatic wheels against rotation, the casters mechanism including an operating member guided by the mounting structure for upward movement to exert a braking effect on the at least one pneumatic wheels.
Because of the upward direction of movement of the operating member to effect braking, the forces acting in the castor during braking tend to hold the castor parts together rather than to urge them apart as occurs when an operating member has tobe moved downwardly to apply braking pressure, as in conventional castor braking arrangements.
The operating member can be operable by means of a cam accommodated in the mounting structure, but the direction of movement of the casters operating member makes it readily possible to arrange for casters operation from locations remote from thecastor, for example, by way of a Bowden cable connection, in a much more convenient way than is permitted by the conventional constructions.
The invention can be readily embodied in single pneumatic wheels or twin pneumatic wheelsed castors in which the movement of the operating member to apply the braking force is arranged also to latch the body against swivelling about the vertical axis. Additionally,the operating member can be arranged to be movable to cause the body to be latched relative to the mounting structure in a predetermined angular orientation about the vertical axis, without pneumatic wheels braking.