GB1564472A

GB1564472A - Cable clamp

Info

Publication number: GB1564472A
Application number: GB79877A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1977-01-10
Filing date: 1977-01-10
Publication date: 1980-04-10

Description

(54) CABLE CLAMP (71) I, PAUL ANDRIAN CORNELL, of 424 S. Beverly Drive, Beverly Hills, California 90212, United States of America a citizen of the United States of America, do hereby declare the invention, for which I pray that a patent may be granted to me, and the method by which it is to be performed, to be particularly described in and by the following statement: Cable connectors of the clamping type, especially useful as electrical connectors and also useful for effecting mechanical cable connections, are known in the art as disclosed in Schuck et al. United States Patent No. 3,118,720. Such a clamp comprises, in general, a female member having a Cshaped sleeve and a male member having a cylindrical head for relative rotatable movement within the sleeve.The sleeve and head have respective diametrical bores which, in the open position of the connector, are axially aligned to receive a cable (such as an electrical conductor). The male and female members have generally coextensive tails which, when secured together, cause the internal surfaces of the bores to exert a clamping force on the cable.

The connector is adapted to be mounted upon a planar body or other mounting surface.

Such connectors are typically designed for use with only a single size cable. In many applications, however, it is desirable to have a single connector which is adapted for use with cables of different diameters.

One such design for connectors of a somewhat similar type is shown in Beaudion United States Patent No. 3,437,979. That design, however, is not suitable for use with connectors of the type contemplated by the present invention.

In attempting to use connectors of this type to clamp cables of different diameters, conflicting considerations arise. A first consideration is the need to keep the cable insertion angle (i.e., the angle formed by the intersection of the axis of the bores with the body upon which the connector is mounted) to a minimum so as to permit insertion of large diameter cables without interference from the mounting surface. A second consideration is to provide for sufficient angular rotation between the male and female members to effect clamping of smaller diameter cables. Recognition of these conflicting considerations is a significant aspect of the concept of the present invention.

In accordance with the present invention, there is provided a lamp type cable connector comprising: a male member including a tail having planar surface for mounting said connector on a planar body; and a generally cylindrical head at one end of said tail, said head having a transverse bore for receiving a cable; a female member including a tail; and a generally C-shaped sleeve at one end of said tail, said sleeve having a transverse bore for receiving said cable; said sleeve being adapted to receive said head for rotatable movement between open and closed positions of said connector as said tails are moved apart or together, said bores being in generally axial registry when said tails are spaced apart in the fully open position of said connector, with the internal surfaces of said bores serving to clamp said cable upon relative rotation of said sleeve and head as said tails are moved together to close said connector; wherein the relative rotation of said sleeve and said head between fully open and closed positions of said connector is through an angle greater than the angle of the axis of the bore in said sleeve with the plane of said surface when said connector is fully open.

A preferred form of connector and a modification thereof both in accordance with the invention. will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a cross-sectional view of a connector embodying the invention, shown in the fully open position with a larger diameter cable inserted therein; Figure 2 is a cross-sectional view of the same connector shown in closed position for clamping the larger diameter cable; Figure 3 is a cross-sectional view of the same connector, shown in fully closed position for clamping a smaller diameter cable; Figure 4 is a top view of the same connector taken on the line 44 a1 in Figure 1; Figure 5 is a transverse sectional view of a portion of the same connector, taken on the line 5-5 of Figure 1;; Figure 6 is a cross-sectional view of a modified form of cable connector embodying the present invention, shown in the closed position for clamping a cable of medium diameter: Figure 7 is a partial top view of the connector of Fig. 6, taken on the line 7-7 in Figure 6; and Figure 8 is an exploded perspective view of the connector of Figure 1.

With reference to the drawings, there is shown in Figures 1-5 and 8 thereof, as an example of one form in which the present invention may be embodied, a clamp type cable connector comprising male and female members 10 and 12, each having a tail, 14 and 16, respectively. The connector is adapted to be mounted upon a planar body or mounting surface 18.

It should be understood that all reference herein to angles and directions are on the basis of the connector being oriented as shown in Figure 1; i.e., with the mounting body 18 in a horizontal position and with the connector mounted on the top side of the body with the tails 14 and 16 extending to the right. In this orientation, the plane of the upper surface of the mounting body 18 will be taken to be the reference (i.e., at 0 ) with angular displacement in a counterclockwise direction therefrom taken as positive and rotation in a clockwise direction taken as negative. It should be understood that this orientation is assumed for purposes only of this description and the appended claims, and that the body 18 and the mounting of the connector thereon may be at any desired orientation.

As shown in Figure 1. the female member 12 includes a generally C-shaped sleeve 24 adapted to mate with a generally cylindrical head 26 on the male member 10. The sleeve 24 of the female member 12 includes a generally diametrical transverse bore 28. The head 26 of the male member 10 includes a similar transverse bore 30.

The connector is shown in Figure 1 in its fully open position for receiving a cable 32. The cable 32 is arbitrarily selected for purposes of this description to be of 4/0 si7e. As can be seen in Figure 1, when the connector is fully open for insertion of the cable 32, the bores 28 and 30 are in generally co-axial alignment, with the axis of the bore 28 being represented by the line A-A.

A line parallel to the upper surface of the mounting body 18 is represented by the line B-B.

The angle formed by the intersection of lines A-A and B-B, the "insertion angle", a, is significant. If the insertion angle a is too larger, it will be difficult or impossible to insert a cable of larger diameter into the connector, due to interference with the upper surface of the mounting body 18 at point 34. As can be seen, the cable 32 must be bent in order to achieve clearance for insertion into the connector. It has been found that the positive acute insertion angle a must be maintained at less than about 30 and, preferably at less than about 18 , with larger diameter cables.

The interrelationship of the male member 10 and the female member 12 can best be appreciated by considering Figure 8 in conjunction with Figure 1. As can be seen from Figure 8, the generally cylindrical head 26 of the male member 10 is adapted for relative rotation within the C-shaped sleeve 24 of the female member 12. The female member 12 is prevented from over-rotation in a counterclockwise direction beyond the fully open position of the connector by the free end 36 of the sleeve which will make contact at point 38 on the male member and serve as a stop for rotation in the counterclockwise direction. The male member 10 also includes one or more teeth 40 on the head portion 26, adapted to mate with corresponding notches 42 on the interior surface of the sleeve 24. These notches provide a lock for the connector as described in Lawlor United States Patent No. 3,801,952.

As can be seen from Figure 1, the tail 14 of the male member 10 has an unthreaded aperture 44. Similarly, the tail 16 of the female member 12 has an unthreaded aperture 46. The apertures are arranged so as to be in substantially co-axial alignment when the tails 14 and 16 are moved toward one another to the closed position of the connector. A screw or bolt 48 passes through the apertures 46 and 44 into a suitably threaded aperture 22 in the body 18. The screw 48 serves as a closure means to maintain the tails 14 and 16 in a fixed angular position and thus to maintain the degree of closure of the connector.

In order to clamp a cable in the connector, the cable 32 is inserted as shown in Figure 1. The tails 14 and 16 are then moved relatively toward one another, causing relative rotation of the sleeve 24 and the head 26. Clamping is effected by the interior surfaces of the bores 28 and 30.

Figure 2 shows the 4/0 size cable 32 in clamped position. It will be noted that the screw 48 is engaged with the threaded aperture 22, thus providing a constant closure pressure on the tails 14 and 16 and a resultant clamping force on the cable 32.

It will be noted in Figure 2, that there is still a fairly large gap between the distal ends 50 and 52 of the respective tails 14 and 16. In other words, but for the provision of a stop, an index, or some other means of achieving a predetermined spacing between the tails 14 and 16, the tails could be brought closer together by further tightening of the bolt 48. This could result in an increased clamping force on the cable 32 which could damage either the cable, the connector or both. Accordingly, a stop member 54 is provided in association with the tail 16. As can be best seen from Figures 4 and 5, the stop member 54 is a generally C-shaped member adapted for sliding movement along the tail 16. The stop member 54 is provided with tabs 56 which are designed to mate with corresponding grooves 58 in the tail member 16.Thus the stop member 54 may be moved along the tail 16 to predetermined locations. The tail 14 of the male member has its upper surface formed into steps, which provide stop surfaces 60, 62 and 64.

The stop member 54, and in particular the lower surface 66 thereof, cooperates with the steps of or stop areas 60, 62 and 64 to provide means for positioning the tails 14 and 16 at three predetermined angular spacings, thus controlling in three steps the degree of closure of the connector. For example, in Figure 2, the stop member 54 is positioned so that its tabs 56 interact with the set of grooves 58 closest to the sleeve 24. Thus the bottom surface 66 of the stop member 54 is positioned to interact with the first step or stop area 60. The height of the stop area 60 is preselected to achieve a proper degree of closure of the connector for the 4/0 cable 32. Thus, when the bolt 48 is tightened down to the point where the stop member 54 contacts the stop area 60, the proper amount of clamping force will be exerted on the 4/0 cable 32.

Figure 3 shows the connector in its fully closed position with a 2/0 cable 68 in place.

With a cable of this size, the stop member 54 is moved to the groove 58 which is closest to the distal end of the tail 16 and the stop member 54 is thus positioned to interact with the lowest stop area 64. Again, the height of the stop area 64 is preselected to achieve a predetermined angular spacing between the tails 14 and 16 and thus control the degree of closure of the connector and exert the appropriate amount of clamping force on the 2/0 cable 68.

It will be noted that the upper surface 70 of the tail 16, in the vicinity of the aperture 46, is curved. This curvature provides a horizontal bearing surface for the underside of the head 72 of the bolt 48 regardless of the degree of closure of the connector.

As can be seen in Figure 3, the line B-B again represents a line parallel to the upper surface of the mounting body 18, and the line A-A represents the axis of the bore 28. With the sleeve 24 rotated to the fully closed position of the connector as shown in Figure 3 with a 2/0 cable 68 clamped in place, the angle b formed by the intersection of lines A-A and B--B is a negative acute angle. In prior art connectors of the type shown in Schuck United States Patent No.

3,118,720, this angle, when the connector is fully closed, is generally zero. Inasmuch as the prior art connectors are designed only for a single cable diameter, this presents no problem, inasmuch as the insertion angle a can be kept acceptably small and satisfactory clamping force can be achieved simply by rotating the tails through an angular displacement approximately equal to the insertion angle a. Inasmuch as the bores of the prior art connectors are sized to receive the single diameter cable with only slight clearance, the required clamping force can be achieved with a smaller angular displacement.Any attempt to use the prior art connector with a smaller diameter cable, however, would be ineffective, because the diameter of the bores would then be significantly larger than the cable and it would be impossible to exert sufficient clamping force on a smaller cable in rotating to the fully closed position of the connector. As long as the angle b is near zero (or positive) the only practicable way to adapt the prior art connector so that it would exert sufficient force to clamp a cable of diameter significantly less than the diameter of the bores would be to increase the insertion angle.But this, as mentioned previously, is undesirable, since an increase in the insertion angle beyond certain limits renders it impossible to insert the cable. (It would, of course, be possible to provide more clearance for a given insertion angle by raising the center of rotation of the connector assembly higher above the mounting body, as by a shim or increased thickness of the male tail; but this increases both size and cost of the connector.) Accordingly, the present invention employs male and female members of a construction which permits the angle b to be negative, thus permitting a sufficient degree of relative rotation between the sleeve 24 and the head 26 to achieve the required clamping force for a small diameter cable, without increasing the insertion angle.In other words, the present invention contemplates a construction which permits the sleeve 24 to rotate through an angle greater than the insertion angle.

Figures 6 and 7 show a modified connector, also embodying the invention, with an alternative positioning means. As shown therein, the sleeve 24 of the female member 16 includes a viewing aperture 74 which permits visual access to the upper surface of the head 26. Inscribed on the head are indicia 76 representing cable diameters.

Thus, in order to achieve the appropriate degree of closure of the connector for clamping, for example, a size 3/0 connector 78. the tails are moved toward one another until the indicia "3/0" is visible tIirough,the aperture 74. The operator will then know that a proper clamping force for a 3/0 size cable is being exerted on the cable 78.

Alternatively, an index system could be inscribed on the sides of the sleeve 24 and head 26.

It will be noted that, in the embodiment of Figure 6, the connector is again mounted to the body 18 by means of the screw 48, which serves both to mount the connector on the body 18 and as the closure means for maintaining the tails 14 and 16 in fixed angular position to maintain the degree of closure of the connector. It should be understood that other mounting means may be employed. For example, a separate screw (not shown) could pass through a suitable aperture in the tail 14 and into a threaded aperture in the body 18 to hold the connector rigidly in place. Alternatively, the aperture 44 could be threaded for the screw 48, with the aperture 22 unthreaded, and a separate nut (not shown) could be used in conjunction with the screw 48 to hold the connector firmly in place on the body 18.

As can be seen, any suitable mounting means may be employed, either separately, or serving also as the closure means.

Again, it should be emphasized, as explained above, that the use of the term "positive" and "negative" angles refers to the particular arbitrary orientation of the connectors in the appended drawings. Any orientation may be used, as desired. It is important to keep the insertion angle a (i.e., the angle between the bore 28 in the female member 12 and the plane of the mounting body 18) as small as possible while still permitting sufficient relative rotation between the head 26 of the male member 10 and the sleeve 24 of the female member 12 to achieve sufficient clamping force for smaller diameter cables.In some cases, as for example with only two sizes of cable, it may be possible to achieve this by permitting the angle b between the axis of the bore 28 in the female sleeve 24 and the plane of the mounting body 18 to be zero or even positive in the fully closed position of the connector. In order to accommodate a wider range of cable diameters, however, it is usually necessary to construct the female and male members so that such angle is negative.

WHAT WE CLAIM IS:- 1. A clamp type cable connector comprising: a male member including a tail having planar surface for mounting said connector on a planar body; and a generally cylindrical head at one end of said tail, said head having a transverse bore for receiving a cable: a female member including a tail; and a generally C-shaped sleeve at one end of said tail, said sleeve having a transverse bore for receiving said cable; said sleeve being adapted to receive said head for rotatable movement between open and closed positions of said connector as said tails are moved apart or together, said bores being in generally axial registry when said tails are spaced apart in the fully open position of said connector, with the internal surfaces of said bores serving to clamp said cable upon relative rotation of said sleeve and head as said tails are moved together to close said connector; wherein the relative rotation of said sleeve and said head between fully open and closed positions of said connector is through an angle greater than the angle of the axis of the bore in said sleeve with the plane of said surface when said connector is fully open.

2. A connector according to claim 1, wherein the axis of the bore in the sleeve forms a negative acute angle with the plane of said planar surface when the connector is fully closed.

3. A connector according to claim 1 or 2, including means for indicating positioning of the tails in each of two or more different relative positions in which cables of different sizes can be securely clamped.

4. A connector according to claim 3, in which the said indicating means comprises a visual index means indicating different degrees of rotation of the said tails.

5. A connector according to claim 3, in which the said indicating means comprises a stop member mounted on one tail for movement relative thereto and co-operating with the other tail in such a manner as to limit closing movement of the two tails to different degrees in respective positions of the stop member on the said one tail.

6. A connector according to claim 5, wherein the stop member is movable longitudinally of the said one tail and co-operates with different stop surfaces formed on the confronting face of the other tail.

7. A connector according to claim 6, wherein movement of the stop member along the one tail towards the free end thereof progressively increases the degree of closure of the two tails.

8. A connector according to any preceding claim, wherein the axis of the bore in

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. an alternative positioning means. As shown therein, the sleeve 24 of the female member 16 includes a viewing aperture 74 which permits visual access to the upper surface of the head 26. Inscribed on the head are indicia 76 representing cable diameters. Thus, in order to achieve the appropriate degree of closure of the connector for clamping, for example, a size 3/0 connector 78. the tails are moved toward one another until the indicia "3/0" is visible tIirough,the aperture 74. The operator will then know that a proper clamping force for a 3/0 size cable is being exerted on the cable 78. Alternatively, an index system could be inscribed on the sides of the sleeve 24 and head 26. It will be noted that, in the embodiment of Figure 6, the connector is again mounted to the body 18 by means of the screw 48, which serves both to mount the connector on the body 18 and as the closure means for maintaining the tails 14 and 16 in fixed angular position to maintain the degree of closure of the connector. It should be understood that other mounting means may be employed. For example, a separate screw (not shown) could pass through a suitable aperture in the tail 14 and into a threaded aperture in the body 18 to hold the connector rigidly in place. Alternatively, the aperture 44 could be threaded for the screw 48, with the aperture 22 unthreaded, and a separate nut (not shown) could be used in conjunction with the screw 48 to hold the connector firmly in place on the body 18. As can be seen, any suitable mounting means may be employed, either separately, or serving also as the closure means. Again, it should be emphasized, as explained above, that the use of the term "positive" and "negative" angles refers to the particular arbitrary orientation of the connectors in the appended drawings. Any orientation may be used, as desired. It is important to keep the insertion angle a (i.e., the angle between the bore 28 in the female member 12 and the plane of the mounting body 18) as small as possible while still permitting sufficient relative rotation between the head 26 of the male member 10 and the sleeve 24 of the female member 12 to achieve sufficient clamping force for smaller diameter cables.In some cases, as for example with only two sizes of cable, it may be possible to achieve this by permitting the angle b between the axis of the bore 28 in the female sleeve 24 and the plane of the mounting body 18 to be zero or even positive in the fully closed position of the connector. In order to accommodate a wider range of cable diameters, however, it is usually necessary to construct the female and male members so that such angle is negative. WHAT WE CLAIM IS:-

1. A clamp type cable connector comprising: a male member including a tail having planar surface for mounting said connector on a planar body; and a generally cylindrical head at one end of said tail, said head having a transverse bore for receiving a cable: a female member including a tail; and a generally C-shaped sleeve at one end of said tail, said sleeve having a transverse bore for receiving said cable; said sleeve being adapted to receive said head for rotatable movement between open and closed positions of said connector as said tails are moved apart or together, said bores being in generally axial registry when said tails are spaced apart in the fully open position of said connector, with the internal surfaces of said bores serving to clamp said cable upon relative rotation of said sleeve and head as said tails are moved together to close said connector; wherein the relative rotation of said sleeve and said head between fully open and closed positions of said connector is through an angle greater than the angle of the axis of the bore in said sleeve with the plane of said surface when said connector is fully open.

the head forms an angle of not more 300 with the said planar surface.

9. A clamp type cable connector substantially as herein described with reference to Figures 1 to 5 and Figure 8 of the accompanying drawings.

10. A clamp type cable connector substantially as herein described with reference to Figures 6 and 7 of the accompanying drawings.