US3833971A

US3833971A - Cable clamps

Info

Publication number: US3833971A
Application number: US00289319A
Authority: US
Inventors: R Grasman; W Hell; W Mullner
Original assignee: Waagner Biro AG
Current assignee: Waagner Biro AG
Priority date: 1971-09-17
Filing date: 1972-09-15
Publication date: 1974-09-10
Anticipated expiration: 1991-09-10
Also published as: FR2154051A5; AT307178B; DE2244675A1

Abstract

A cable clamp adapted for use in cable-stretching installations. The cable clamp includes stationary and swingable clamp assemblies where the swingable assembly is connected to the stationary assembly for swinging movement with respect thereto between clamping and unclamping positions. The stationary assembly is formed as a power cylinder for a piston guided for movement toward the swingable assembly and urging a lining which directly engages the cable toward a corresponding lining carried by the swingable assembly.

Description

Grasman et a1.

1451 Set. 10, 1971 CABLE CLAMPS [75] Inventors: Rudolf Grasmaln; Walter Hell;

Wilhelm Mullner, all of Vienna,

Austria [73] Assignee: Waagner-Biro A.G., Vienna, Austria [22] Filed: Sept. 15, 1972 [21] Appl. No.: 289,319

[30] ForeignApplication Priority Data Sept. 17, 1971 Austria 8119/71 [52] Us. Cl. 24/132 WL, 24/249 DP, 24/263 DH, 269/31 [51] lint. Cl F16g 11/00, A44h 21/00 1 Field -2,62 .49 PLZQEPL; 2.6 .125. 24/010. 26, 132 ws, 132 HL, 132 R, 132

[56] References Cited UNITED STATES PATENTS 436,967 9/1890 Crawford..... 24/249 DP 1,842,026 1/1932 Hulshizer 24/D1G. 26 2,615,682 10/1952 Stone 81/57.l5 2,649,283 8/1953 Lundeen 81/57.19 2,695,189 11/1954 Chrisman 24/263 DL 2,857,824 10/1958 Fair 24/263 DH 2,985,455 5/1961 Powell 269/31 Primary Examiner-Bemard A. Gelak Attorney, Agent, or Firm-Steinberg and Blake [5 7 ABSTRACT A cable clamp adapted for use in cable-stretching installations. The cable clamp includes stationary and swingable clamp assemblies where the swingable assembly is connected to the stationary assembly for swinging movement with respect thereto between clamping and unclamping positions. The stationary assembly is formed asja power cylinder for a piston guided for movement toward the swingable assembly and urging a lining which directly engages the cable toward a corresponding lining carried by the swingable assembly.

6 Claims, 1 Drawing Figure BACKGROUND OF THE INVENTION the clamp which carries the 'hydraulicstructure is movable, difficulties are encountered in connection with inserting the cable which is to be stretched into such a clamp.

SUMMARY OF THE INVENTION It is accordingly a primary object of the present invention to avoid these drawbacks.

In particular, it is an object of the invention to provide a cable clamp structure which is capable ofutilizing the force of a fluid under pressure while at the same time avoiding difficulties which are encountered when the fluid-pressure system is mounted on a movable part of the clamp. 1

According to the invention the clamp includes a stationary clamp means and a swingable clamp means connected to the stationary clamp means for swinging movement with respect thereto between clamping and unclamping positions. These stationary and swingable clamp means respectively have linings for respectively engaging a cable at opposed positions of the latter. The stationary clamp means has the form of a power cylinder and includes a piston which is movable toward the swingable clamp means for urging the lining of the stationary clamp means toward the lining of the swingable clamp means.

BRIEF DESCRIPTION OF DRAWING The invention is illustrated by way of example in the accompanying drawing which forms part of this application and in which one embodiment of a clamp according to the invention is illustrated in a sectional elevation.

DESCRIPTION OF PREFERRED EMBODIMENTS Referring to the drawing, the cable clamp illustrated therein includes a lower stationary clamp means 1 which has the form of a power cylinder 8 and which is pivotally connected with a swingable clamp means 2. The power cylinder 8 which forms part of the stationary clamp means accommodates in its interior a piston 3 capable of pressing a lower clamp lining 4 of the stationary clamp means 1 toward a clamp lining of the swingable clamp means 2. For this purpose the stationary clamp means 1 accommodates in its hollow interior a guide member 9 which is slidably guided for movement toward and away from the lining 10 when a cable is clamped, this guide member 9 being connected to the piston 3 to be moved thereby. The fluid under pressure which enters the power cylinder 8 may be a liquid in the case of hydraulic operation or compressed air in the case of pneumatic operation.

The upper clamp lining 10 is directly carried by the swingable clamp means 2 which is swingable on a pin 11 carried by the stationary clamp means 1.

A fluid-pressure means is provided to swing the clamp means 2 with respect to the pin 11. This fluidpressure means includes a power-cylinder 7 swingably connected by the pin 12 to the stationary clamp means 1 and a piston shiftable in the cylinder 7 and having a piston rod pivotally connected by a pin 13 to the swingable clamp means 2.

A releasable lock means 5 is provided for releasably locking the swingable clamp means 2 in the illustrated position when a cable is clamped. This releasable locking means includes the lock lever 5 which isswingable .on a pin 14 carried by the stationary clamp means 1. A

fluid-pressure means 6 has a power cylinder pivotally connected at one end to the stationary clamp means 1, this cylinder accommodating a piston whose piston rod is pivotally connected to the lock lever 5 on the side of pin 14 opposite from the locking projection at the top of the lever 5 which overlaps the left hand portion of the swingable clamp means 2, as viewed in the drawing, to maintain the clamp means 2 in its locked operating position.

In order to bring about clamping of a cable, the piston 3 is constructed as a double-acting piston and has lower and'upper chambers separated by a flange 17 and respectively communicating with the

bores

15 and 16 through which a pressure fluid such as oil or air is adapted to be introduced. When fluid under pressure is introduced through the bore 15, the chamber above flange 17 may be vented through the bore 16 and the lining 4 will be pressed toward the lining 10. When fluid under pressure is introduced through the bore 16 the chamber beneath flange 17 is vented through the bore 15 so that the piston 3 will be retracted. The guide piece 9 is fixed to the piston 3 by way of a bolt 18.

In cable-stretching systems, several cable clamps are disposed one behind the other'with their upper and lower portions acting as mutual supports for each other and with the last clamp in the series being supported against a frame of the installation. To simplify the illustration the cells of the pressure-transmitting components are not illustrated.

For safety purposes, it is not possible to introduce fluid under pressure into the chamber beneath the flange 17 unless the releasable lock means 5 has first been moved to its locking position shown in the drawing. Of course, the swingable clamp means 2 is first moved to the position shown in the drawing before the lock means is displaced to the position shown in the drawing. It is only then that it is possible with the safety device to urge the piston 3 toward the lining 10.

As is apparent from the drawing, when the swingable clamp means 2 is in its clamping position shown in the drawing, the lining 10 of the swingable clamp means and the lining 4 of the stationary clamp means respectively have inner concave surfaces opposed to each other and each extending approximately around a given axis which is perpendicular to the axis of the power cylinder 8. Also, as is apparent from the drawing, the stationary clamp means 1 has a pair of opposed walls part of which form part of the power cylinder 8, with these opposed walls extending parallel to the axis of the cylinder 8. In its clamping position the swingable clamp means 2 has opposed portions which are respectively in line with the opposed walls of the stationary clamp means 1, these opposedwalls being shown at the left and right in the drawing. It will be noted that the lock means 5 engages the left portion of the swingable clamp means 2 which is in line with the left wall of the stationary clamp means while the pivot means 11 is operatively connected with the right portion of the swingable clamp means 2 which is in line with the right wall of the stationary clamp means 1, as viewed in the drawingi As a result, since these opposed walls of the stationary clamp means 1 are situated equidistantly from the axis of the power cylinder 8 the force applied to the piston 3 is substantially evenly distributed between the opposed walls inasmuch as the moment arms are substantially equal, and in addition these moment arms are necessarily extremely short, because the opposed left and right portions of the swingable clamp means 2 are respectively in line with the opposed walls of the stationary clamp means 1, when the swingable clamp means 2 is in its illustrated clamping position, and as a result it is possible for the structure of the invention to withstand extremely large forces as are required for purposessuch as cable stretching.

What is claimed is:

1. In a clamp for clamping a cable or the like during a stretching operation such as a cable-stretching operation, stationary clamp means having a lining adapted to engage a cable or the like, swingable clamp means swingably connected to said stationary clamp means for movement to a clamping position and having a lining adapted to engage a cable or the like at a part thereof diametrically opposed to the lining of said stationary clamp means, said linings respectively having inner concave surfaces each extending approximately 180 around a given axis when said swingable clamp means is in said clamping position thereof, said stationary clamp means having in part the construction of a power cylinder and including a pair of opposed walls forming part of said cylinder and extending parallel to and situated at equal distances on opposite sides of the axis of said cylinder, said cylinder axis being perpendicular to said given axis, and said stationary clamp means accommodating in said cylinder a slidable piston which is operatively connected with said lining of said stationary clamp means for urging the latter lining along the axis of said cylinder toward the lining of said swingable clamp means when said swingable clamp means is in said clamping position and fluid under pressure is introduced into said cylinder of said stationary clamp means, said swingable clamp means having when in said clamping position thereof a pair of opposed portions which are respectively in line with said opposed walls of said stationary clamp means, lock means operatively connected with said stationary clamp means and engaging one of said opposed portions of said swingable clamp means for releasably locking said swingable clamp means in said clamping position thereof with respcct to said stationary clamp means, and pivot means swingably connecting the other of said opposed portions of said swingable clamp means, which is in line with the other of said opposed walls of said stationary clamp means, to said stationary clamp means for swingable movement with respect thereto about an axis which is parallel to said given axis.

2. The combination of claim 1 and wherein said piston is a double-acting piston.

3. The combination of claim 1 and wherein a fluid pressure means is operatively connected with said stationary and swingable clamp means for swinging said swingable clamp means with respect to said stationary clamp means.

4. The combination of claim 1 and fluid-pressure means operatively connected with said lock means and said stationary clamp means for displacing said locking means between locking and unlocking positions.

5. The combination of claim 1 and safety means preventing operation of said piston unless said swingable lock means is locked with respect to said stationary lock means.

6. The combination of claim 1 and wherein said stationary clamp means includes a guide member carrying said lining of said stationary clamp means and guided by said opposed walls of said stationary clamp means for movement toward and away from said lining of said swingable clamp means, when said swingable clamp means is in said clamping position thereof, said piston being operatively connected to said guide member for moving the latter.

Claims

1. In a clamp for clamping a cable or the like during a stretching operation such as a cable-stretching operation, stationary clamp means having a lining adapted to engage a cable or the like, swingable clamp means swingably connected to said stationary clamp means for movement to a clamping position and having a lining adapted to engage a cable or the like at a part thereof diametrically opposed to the lining of said stationary clamp means, said linings respectively having inner concave surfaces each extending approximately 180* around a given axis when said swingable clamp means is in said clamping position thereof, said stationary clamp means having in part the construction of a power cylinder and including a pair of opposed walls forming part of said cylinder and extending parallel to and situated at equal distances on opposite sides of the axis of said cylinder, said cylinder axis being perpendicular to said given axis, and said stationary clamp means accommodating in said cylinder a slidable piston which is operatively connected with said lining of said stationary clamp means for urging the latter lining along the axis of said cylinder toward the lining of said swingable clamp means when said swingable clamp means is in said clamping position and fluid under pressure is introduced into said cylinder of said stationary clamp means, said swingable clamp means having when in said clamping position thereof a pair of opposed portions which are respectively in line with said opposed walls of said stationary clamp means, lock means operatively connected with said stationary clamp means and engaging one of said opposed portions of said swingable clamp means for releasably locking said swingable clamp means in said clamping position thereof with respect to said stationary clamp means, and pivot means swingably connecting the other of said opposed portions of said swingable clamp means, which is in line with the other of said opposed walls of said stationary clamp means, to said stationary clamp means for swingable movement with respect thereto about an axis which is parallel to said given axis.