GB2072959A

GB2072959A - Cable clamps

Info

Publication number: GB2072959A
Application number: GB8010516A
Authority: GB
Original assignee: Chloride Group Ltd
Current assignee: Chloride Group Ltd
Priority date: 1980-03-28
Filing date: 1980-03-28
Publication date: 1981-10-07
Also published as: ZA812045B; ES267162Y; ES267162U; GB2072959B

Abstract

A generally planar one-piece plastics cable clamp 18 has a housing 20 defining an arch and upstanding formations 26, 28, 30, 32 and 34 defining an S shaped pathway so that in use the cable 42 passes through the arch turning a first curve of more than 90 DEG and then between the upstanding formations by which the cable is constrained to extend in two further curves of more than 90 DEG in a plane perpendicular to that of the first curve. There is also disclosed a battery incorporating such a cable clamp in a space defined between an inner lid 4 and an outer lid 14. <IMAGE>

Description

SPECIFICATION Cable clamps The present invention relates to cable clamps.

Such clamps are generally used anchored on or adjacent apparatus that is powered by or supplies electric power via an electric cable, and serve to absorb force applied to the cable to prevent the force acting directing on the electrical connection between the cable and the apparatus and potentially breaking this connection.

According to the present invention a cable clamp has a pathway adapted to receive a cable, the pathway being so shaped that, in use, the cable is constrained to turn through a first curve of at least 900 in one plane, then through a second curve of at least 900 in a second plane and then through a third curve of at least 900. The first and second planes are preferably perpendicular and the second and third curves are preferably in the same plane.

The clamp, which may be of generally planar construction, preferably has on it an arch which, in use, constrains the cable to turn through the first curve, and upstanding formations which constrain the cable to extend in an S shaped configuration which afford the second and third curves. The arch is preferably afforded by an upstanding hollow housing having an aperture in what will be termed its upper surface and an aperture in one of its walls, so that, in use, the cable passes into the first aperture and out of the other. The housing is preferably open-bottomed to facilitate the introduction of the cable into the pathway.

The upstanding formations preferably comprise two walls extending away from the housing and defining between them the S shaped portion of the pathway, the first wall having a first projection spaced from the housing and extending towards the second wall and a second projection more remote from the housing and extending in the same or similar direction to the first projection, the second wall having a projection extending towards the first wall and located between the first and second projections of the first wall, the cable in use passing around the first projection on the first wall in its second curve and around the projection on the second wall in its third curve.

In the preferred embodiment the cable clamp is a one-piece plastics moulding of e.g.

polypropylene. The invention aiso embraces electric apparatus to which such a clamp is anchored, in particular an electric storage battery having a space below its lid in which the clamp is retained.

In the preferred embodiment of the invention an electric storage battery has one or more cells sealed by an inner lid and having a further outer lid in which a hole is formed, the inner and outer lids defining a space accommodating the cable clamp, and a cable passing through the hole in the outer lid and along the pathway afforded by the clamp and being electrically connected to the terminal connectors of the battery. The clamp may be positively secured in position, but preferably the space is so dimensioned that this is not necessary and the clamp is merely retained in place by virtue of its geometry. The clamp preferably has terminals to which the cable is connected and which are in turn connected to the terminal connectors of the battery.It will be appreciated that the hole in the upper lid is positioned above the archway which will absorb tensile forces applied to the cable, and the upstanding formations further restrain the cable against movement so that no force applied to the cable is applied to the electrical connections.

Further features and details of the invention will be apparent from the following description of a miners cap lamp battery in accordance with the invention which is given by way of example with reference to the accompanying drawings in which Figure 1 is an exploded perspective view of the battery showing the upper portion of the battery container, the cable clamp and the outer lid; Figure 2 is a plan view of the cable clamp; and Figure 3 is a sectional elevation on the line Ill-Ill in Figure 2.

Referring firstly to Figure 1 the battery comprises a container 2 of polycarbonate or glasscoupled polypropylene material containing two cells sealed by a common inner lid 4. The lid 4 has formed in it two wells 6, each accommodating a vent tube 8 communicating with the interior of a respective cell. The lid 4 also affords a rectangular section recess 10 whose function will be explained below. On its rear surface the container has two integral belt loops 12 to secure the battery to a miner's belt.

In use, the battery is capped by a second outer lid 14 which is secured to the container 2 by means which form no part of the present invention. In its upper surface the lid has a central aperture 1 6. The lids 4 and 14 define a space which accommodates a generally planar cable clamp 18 in accordance with the invention which is formed as a one piece injection moulding of polypropylene.

On its upper surface the cable clamp is formed with an open bottomed hollow rectangular housing 20 having an aperture 22 in its upper surface and a further aperture or cut-away portion 24 in its lefthand wall, as seen in Figures 1 and 2.

Integral with the far wall of the housing 20 is a first wall 26 having a first projection 30 and a second projection 28. The first projection 30 of the first wall 26 extends parallel to the second projection 28. Spaced from the first wall and extending generally parallel to it is a second wall 32 having at its end remote from the housing 20 a projection 34 inclined to it at about 450 and extending towards the first wall 26 between the projections 30 and 28. The wall portions 26 and 32 and projections 28, 30, and 34 therefore together define a generally S shaped pathway.

The clamp carries an electrical screw connector 36, whose function will be described below, and on its lower surface a fuse 37 which is accommodated in the recess 10 and is connected to two electrical connectors 38 and 40 on the upper surface of the clamp. The connectors 36, 38 and 40 and the fuse 37 have been omitted from Figures 2 and 3 for the sake of clarity.

In use, the terminal connectors of the battery (which are on its rear upper surface and are not visible in Figure 1) are permanently electrically connected to the connectors 36 and 40 respectively. As shown in chain-dotted lines in Figure 1 the cable 42, which has two cores, passes through the hole 16 in the upper lid and is secured therein against lateral movement by a plastics grommet (not shown). The cable then passes into the housing 20 via the aperture 22 and out again through the aperture 24 thereby passing under the arch formed by the material of the housing between the apertures 22 and 24 and is thus constrained to extend in curve of somewhat more than 900 in a vertical plane.The cable then passes through the gap defined by the wall 32 and the projection 30 and then through the further gap defined between the wall 26 and the projection 34, and thence parallel to the second projection 28 of the first wall for a short distance. The cable is thus constrained to extend through two further curves in opposite senses of more than 900 in the same plane inclined at 900 to the plane of the first curve. The cable then extends towards the connector 36 to which one of the cores is connected, whilst the other core is connected to the connector 38, which is connected to the connector 40 via the fuse 37.

The cable clamp thus absorbs all forces exerted on the cable 40 and prevents direct mechanical force being applied to the electrical connections.

The fuse 37 has an appropriate value of say 3 amps to ensure that the current which the battery delivers is not substantially above its rated value which may be of the order of 2 amps. If it is required to replace the cable, which is frequently the case for batteries used under mining conditions, this may be done without disturbing the relatively fragile battery terminal connectors since the permanent connections to the terminals 36 and 40 are not subject to damage and may therefore be left undisturbed.

It will be appreciated that the cable clamp may be integrally moulded with the battery lid or with any other appropriate component of the apparatus in which the cable clamp is to be used.

Claims

1. A cable clamp having a pathway adapted to receive a cable, the pathway being so shaped that in use, the cable is constrained to turn through a first curve of at least 900 in one plane, then through a second curve of at least 900 in a second plane and then through a third curve of at least 900.

2. A clamp as claimed in Claim 1 in which the first and second planes are perpendicular.

3. A clamp as claimed in Claim 1 or Claim 2 in which the second and third curves are in the same plane.

4. A clamp as claimed in any one of the preceding claims which is of generally planar construction.

5. A clamp as claimed in any one of the preceding claims having an arch through which, in use, the cable passes and is thereby constrained to turn through the first curve.

6. A clamp as claimed in Claim 5 in which the arch is afforded by an upstanding hollow housing having an aperture in what will be termed its upper surface and an aperture in one of its walls so that, in use, the cable passes into the first aperture and out of the other.

7. A clamp as claimed in Claim 6 in which the housing is open-bottomed.

8. A clamp as claimed in any one of the preceding claims having upstanding formations which, in use, constrain the cable to extend in an S shaped configuration which affords the second and third curves.

9. A clamp as claimed in Claim 8 when dependent on any one of Claims 6 or 7 in which the upstanding formations comprise two walls extending away from the housing and defining between them the S shaped portion of the pathway, the first wall having a first projection spaced from the housing and extending towards the second wall and a second projection more remote from the housing and extending in the same or similar direction to the first projection, the second wall having a projection extending towards the first wall and located between the first and second projections of the first wall, the cable, in use, passing around the first projection on the first wall in its second curve and around the projection on the second wall in its third curve.

10. A cable clamp substantially as specifically herein described with reference to the accompanying drawings.

11. An electric battery incorporating a clamp as claimed in any one of the preceding claims.

12. A battery as claimed in Claim 11 having one or more cells sealed by an inner lid and having a further outer iid in which a hole is formed, the inner and outer lids defining a space accommodating the cable clamp, and a cable passing through the hole in the outer lid and along the pathway afforded by the clamp and being electrically connected to the terminal connectors of the battery.

13. An electric battery substantially as specifically herein described with reference to the accompanying drawings.

13. A battery as claimed in Claim 12 in which the clamp is retained in position by virtue of its geometry.

14. A battery as claimed in Claim 12 or Claim 13 having terminals to which the cable is connected and which are in turn connected to the terminal connectors of the battery.

1 5. An electric battery substantially as specifically herein described with reference to the accompanying drawings.

New claims or amendments to claims filed on 29/1/81 Superseded claims 1-1 5 New or amended claims:

1. A cable clamp having a pathway adapted to receive a cable and including an arch afforded by an upstanding hollow housing having an aperture in what will be termed its upper surface and an aperture in one of its walls so that, in use, the cable passes into one aperture and out of the other and is thereby constrained to turn through a first curve of at least 900 and further including upstanding formations which, in use, constrain the cable to turn through a second curve of at least 900 in a second plane and then through a third curve of at least 900.

4. A clamp as claimed in Claim 3 in which the upstanding formations, in use, constrain the cable to extend in an S shaped configuration.

5. A clamp as claimed in any one of the preceding claims which is of generally planar construction.

6. A clamp as claimed in any one of the preceding claims in which the hollow housing is open-bottomed.

7. A clamp as claimed in Claim 4 in which the upstanding formations comprise two walls extending away from the housing and defining between them the S shaped portion of the pathway, the first wall having a first projection spaced from the housing and extending towards the second wall and a second projection more remote from the housing and extending in the same or similar direction to the first projection, the second wall having a projection extending towards the first wall and located between the first and second projections of the first wall, the cable, in use, passing around the first projection on the first wall in its second curve and around the projection on the second wall in its third curve.

8. A cable clamp substantially as specifically herein described with reference to the accompanying drawings.

9. An electric battery incorporating a clamp as claimed in any one of the preceding claims.

10. A battery as claimed in Claim 9 having one or more cells sealed by an inner lid and having a further outer lid in which a hole is formed, the inner and outer lids defining a space accommodating the cable clamp, and a cable passing through the hole in the outer lid and along the pathway afforded by the clamp and being electrically connected to the terminal connectors of the battery.

11. A battery as claimed in Claim 10 in which the clamp is retained in position by virtue of its geometry.

12. A battery as claimed in Claim 10 or Claim 11 having terminals to which the cable is connected and which are in turn connected to the terminal connectors of the battery.