US3863893A - Cable traction and hoisting apparatus - Google Patents

Abstract

This traction and hoisting apparatus operating on a loaded cable by means of a pair of control levers, one for the forward motion and the latter for the controlled reverse motion, comprises in a relatively flat casing consisting of two halves, two pairs of clamping jaws, the jaws of each pair being interconnected by levers having their lower ends connected to forward-motion and reverse-motion rods made of punched flat sheet metal stock and their upper ends operatively connected to the reverse motion control lever; one of said rods comprises a lateral aperture permitting the passage and lateral exit of the slack run of the cable; a pull-rod normally retained by an inner projection of said casing keeps a pair of compression springs in their pretightening condition.

Description

United States Patent Cavalieri Feb. 4, 1975 3,702,689 11/1972 Zeller 254/107 Primary Examiner-Al Lawrence Smith [75] Inventor. iglrlsiice Cavalieri, Neuilly sur Marne, Assistant Examiner-3oben 0 Watson Attorney, Agent, or Fzrm-Ulle C. Linton [73] Assignee: Tractel S. A., Bagnobt, France 22 Filed: June 21,1973 d A S 1s traction an oistlng apparatus operating on a [211 App! 372304 loaded cable by means of a pair of control levers, one

for the forward motion and the latter for the con- [30] F i A li ti P i it D t trolled reverse motion, comprises in a relatively flat June 27 1972 France 7223132 casing consisting of two halves two Pairs of clamping jaws, the jaws of each pair being interconnected by le- 52 vs. 01 254/76, 254/106, 254/135 Vets having their ends Connected fmward- 51] Int. Cl 866d 1/00, B66f 1/00 motion and reverse-mono F made of Punched, flat [58] Field 61 Search 254/76, 105, 106, 107, Sheet metal Stock and ends operatwely 254/135; 24/134 N connected to the reverse motion control lever; one of said rods comprises a lateral aperture permitting the [56] References Cited paslsage and lateral exit of th; slack run of the cable; af

u -rod norma y retained y an inner projection 0 UNITED STATES PATENTS said casing keeps a pair of compression springs in their 2,585,101 2/1952 Faure 254/76 pretightening condition 2,995,339 8/1961 Persiaux 254/76 3,222,742 12/1965 Persiaux 254/76 4 Claims, 3 Drawing Figures 3s, 1T) I 38 1 40 za 8 3 n a 20 8 2s 22 13 4 1 x V 2o m III 3111: 2 h 21 9 -r-- crtir 1 19 3 I l l l l 3 CABLE TRACTION AND HOISTING APPARATUS BACKGROUND OF THE INVENTION The present invention relates in general to traction and hoisting apparatus of the type operating by means of self-clamping jaws, and has specific reference to an improved apparatus of this type, adapted to clamp a loaded metal cable.

BRIEF DESCRIPTION OF THE PRIOR ART More particularly, metal-cable traction and hoisting apparatus are already known wherein the cable is hauled or released by a pair of self-tightening clamps to which rectilinear reciprocating movements are imparted in opposite directions, the clamp which travels in the direction of motion to be imparted to the cable being tightened thereon so as to travel bodily with the cable while the other clamp is released and moves along the cable in the opposite direction. In known apparatus of this type each clamp comprises as a rule a pair of jaws between which the cable is passed, said jaws being interconnected by sets of parallel tightening levers whereby movements of translation are imparted thereto causing said jaws to move either towards each other in the tightening position or away from each other in the release position; the ends of these tightening levers are connected on one side of the cable to a pair of control or driving rods moving in opposite directions and responsive to a control lever, usually referred to as the forward motion lever, disposed near the end of the apparatus which is opposite to the inlet of the tight run of the cable for pulling same, the other ends of the tightening levers being connected to another control lever usually referred to as the reverse lever, thus permitting the alternating movement in opposite directions of the pair of clamps but with the reversal of the tightening and release, respectively, thereof, for producing the hauling-off or release, that is, the controlled backward motion of the cable urged by the load attached thereto. Moreover, in these known apparatus the clamps are somewhat pre-tightened so that, by virtue of the reaction produced by the cable on the clamps, the clamp urged in the forward direction by the forward motion lever or the clamp urged in the backward direction by the reverse motion lever, is locked automatically.

As a rule, these apparatus are adapted to be anchored to a fixed point, for example by means ofa hook provided at the front end of the apparatus so that the hauling or hauling-off operation can be accomplished according as one or the other control lever is actuated; clutch means are provided for eliminating the pre tightening action when it is desired to permit the free passage of the cable through the apparatus, for instance when the cable is introduced into the apparatus or on the contrary has to be removed therefrom.

In apparatus of the type broadly disclosed hereinabove the cable extends and travels through the apparatus along a substantially rectilinear longitudinal path, so that manufacturers were led to utilize forged component elements notably for the forward motion mechanisms, with complicated shapes for permitting the rectilinear passage of the slack run of the cable at the front of the apparatus, and the egress of the slack cable run through the tubular rod of the anchoring hook. Under these conditions, relatively cumbersome and heavy apparatus, of relatively high cost, were obtained, thus positively limiting the field of application of the apparatus.

SUMMARY OF THE INVENTION It is the primary object of the present invention to provide an apparatus operating according to the principle set forth hereinabove but having exceptionally reduced over-all dimensions and weight, which comprises but a minimum number of flat parts punched from sheet-metal stock, without resorting to any forged or molded metal parts whatsoever, the thickness of the apparatus in a direction perpendicular to the cable being extremely reduced and the mechanism transmitting to the surrounding casing only very reduced efforts, thus permitting the use of a lightweight casing having a generally very flat shape.

To comply with the latest safety regulations and obtain a highly reliable operation, the essential feature characterising the apparatus according to this invention is that the two control rods performing opposite longitudinal movements when actuated by the forward motion control lever, as well as this control lever itself consist exclusively of flat punched parts, that said control rods are guided by one another towards the ends of the apparatus, that the forward motion control lever is pivoted to a link connected to the anchoring hook without any connection with the casing, and that furthermore one of the control rods consists of a pair of flanges disposed on either side of the other rod and carries a deflecting plate directing the outgoing cable laterally through an opening formed to this end in a lateral face of the casing.

The cable flexibility permits an easy egress of the cable from a side wall of an apparatus of relatively reduced dimensions, ahead of its rectilinear passage through the pair of clamps. It is clear that this lateral egress leaves ample room in the front portion of the apparatus, throughout the thickness of the mechanism, for housing the control rods and the control lever. Moreover, by causing each rod to be guided by the other rod any guiding effort reacting against the casing is definitely or substantially eliminated, and pivoting the control lever directly to the anchoring hook avoids the application of undue tractive efforts to the casing proper, so that a light-weight casing of very reduced thickness may be contemplated.

According to a complementary feature characterising this invention, the pre-tightening is produced by providing a pair of longitudinal coil compression springs reacting between'the reverse motion lever and a member rigid with an upper clutch-release control rod adapted to be set at the front of the casing in the spring pre-tightening position for a normal operation of the apparatus, releasing this rod eliminating the pretightening force to permit the free passage of the cable (release position). Advantageously, the clutch control rod comprises on one fraction of its length a pair of plates parallel to the lateral faces of the casing, between which the flat forward-motion control lever can extend.

A clearer understanding of this invention will be had as the following description proceeds with reference to the accompanying drawing illustrating diagrammatically by way of example a typical form of embodiment of the apparatus constituting the subject-matter of the invention. In the drawing:

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a side elevational and sectional view of the apparatus from which a casing half together with onehalf of a control rod have been removed in order to show more in detail the mechanism, and

FIG. 2 is a detail section taken along the line llll of FIG. 1.

FIG. 3 is a top view of the control rod assembly.

DESCRIPTION OF THE PREFERRED EMBODIMENT The mechanism is enclosed in the relatively flat casing consisting of a pair of elongated and shallow halves 1, 2 substantially symmetrical to each other and assembled by means of screws or bolts passing through assembly holes 3 properly distributed near the outer periphery of the casing halves. The taut run of the traction cable or rope 4 is adapted to penetrate into the casing at 5, i.e., at the casing end to be referred to as the rear end, the slack run 6 of the cable or rope 4 being adapted to emerge from the casing through a longitudinal slot 7 formed at mid-height of the casing half 2 (i.e., the half removed from FIG. 1).

Projecting from the front end of the casing, between a pair of registering notches formed in said halves l, 2, is an anchoring hook 8 fulcrumed to a transverse pivot pin 9 carried by one end of a double retaining link 10 having its other end pivoted to a transverse pivot pin 11 carried by the so-called forward-motion control lever 12 adapted to drive the cable in the forward direction by pulling or hoisting a load attached to the cable. The control lever 12 actuates the control rods performing longitudinal movements in opposite directions through a pair of pivot pins 13 and 14 disposed symmetrically on either side of pivot pin 11. Pivotally connected to pin 13 are a pair of parallel spaced flanges constituting the control rod 15 actuating the rear clamp, and pivotally connected to pin 14 is one end of a double longitudinal link 16 having its other end pivotally connected to a central member 17 constituting the front clamp control rod.

The two clamps are similar and each comprises an upper jaw 18 formed with a lower groove of arcuate cross-section contour and a lower jaw 19 formed with an upper groove of same contour. The jaws l8, 19 of each clamp carry each a pair of transverse pivot pins designated by the reference numerals 20 and 21, respectively, to which two pairs of tightening levers (22-24 for the rear clamp and 23-25 for the front clamp) are pivoted, the levers of each pair being dis.- posed on either side of the corresponding jaws l8, l9 and having a downward extension pivotally connected by means of pins 26 to rod 15 in the case of the rear clamp and by means of pins 27 to rod 17 in the case of the front clamp.

The rear tightening levers of the front clamp are pivoted about the upper jaw 18, by means of a pin 28, to the lower end of the reverse control lever 29, and the rear tightening levers 24 of the rear clamp are pivoted through a pivot pin 30 to one end of a link 31 having its other end pivoted by means of a pin 32 to said control lever 29. Substantially half-way between pins 28 and 32 said control lever 29 carries a double strap 33 adapted to receive the thrust of a pair of pre-tightening coil compression springs 34 surrounding tie-rods 35 adapted to slide through a yoke 36 receiving the front ends of said springs 34 opposite said strap 33. The yoke 36 is an integral part of a control rod 37 emerging from the casing of the apparatus above the anchoring hook and carrying on its outer end a release control knob 38 permitting of either setting the control rod 37 in its rear position in which the springs 34 are somewhat compressed, or releasing said rod 37 to permit the expansion of these springs 34. To this end, the control rod 37 consisting for example of a piece of sheet metal bent to a U-shaped cross-sectional configuration carries on its lower face a retaining catch or notch 39 adapted to be engaged by a projection, for instance a small plate 40, rigid with the casing. The tie-rods 35 may consist if desired of metal wires bent to a U shape, and the double strap 33 may consist of a suitably shaped plate through which these tie-rods 35 are passed.

The pair of control rods l5, 17 are guided by each other during their movements of translation in opposite directions by a distance piece 41 rigid with rod 15 and passing through a roller 42 engaging the edges of an elongated hole 43 formed in the front portion of rod 17, the other end of said rod 17 having an integral guiding extension 44 movable between a pin 45 rigid with rod 15 and the aforesaid pivot pins 26.

At its front portion and level with the cable 4 the rod 15 carries a deflector 46 (FIG. 2) adapted to guide the cable 4 in an oblique outward direction to permit the exit thereof through an aperture 47 formed in one of the flanges of rod 15 and also through the longitudinal opening 7 formed in the corresponding half 2 of the casing.

Now the mode of operation of this apparatus, which is similar to that of hitherto known traction and hoisting apparatus comprising two clamps operating in opposite directions for alternatively clamping and releasing the cable, will be described.

To eliminate the pre-tightening action and permit the free passage of the cable 4 through the pairs ofjaws l8, 19 of the two clamps, the springs 34 are released by triggering the control rod 37 and allowing same to emerge to a greater extent from the casing l, 2. Thus, the free end of a cable attached to a load can be inserted freely through the inlet 5 until this end emerges laterally from the casing, after having passed through the pair of clamps, as already explained hereinabove. Then, if the rod 37 is reset to compress the springs 34 the apparatus is ready for pulling or hoisting the load through the cable 4.

By actuating the control lever 12 to-and-fro, i.e., forwards and backwards, the clamps are moved in opposite directions and the clamp pulled forwards from beneath is tightened because the rotation of the tightening levers 22, 24 or 23, 25 of the clamps in the clockwise direction about their pivot pins 26, 27 tends to increase the tightening action. Since the other clamp pushed backwards is released, in contrast to the action produced with the first clamp, due to the action of the levers of said other clamp of which the line of axes 20, 21 is straightened to a position substantially perpendicular to the cable axis while moving its jaws l8, 19 away from each other, it is clear that this actuation will cause the cable 4 and the load attached thereto to move in the forward direction, i.e., towards the apparatus.

If on the other hand a similar to-and-fro movement is impressed to the reverse control lever 29, the two clamps will likewise operate in opposite directions, but the one moved in the forward direction is released while the other is tightened, thus permitting a controlled backward movement of the load due to the outward movement of the tight run of the cable through the inlet aperture 5.

From the foregoing it is clear that the control rods and the levers associated therewith consist of flat pieces of punched sheet metal stock and that the overall thickness of the casing l, 2 can be reduced considerably, since it is only necessary that this thickness corresponds to the sum of the thicknesses of the pair of flanges constituting the rod 15, of the pair of flanges constituting the link 16 and of the lever 12 or rod 17 (these two last-mentioned parts being disposed in a common central plane between the two flanges constituting said rod 16), plus the necessary play, and of course the thickness of the casing halves l and 2. Under these conditions, an extremely flat casing may be obtained. Since on the other hand this casing is subjected only to the relatively moderate pre-tightening efforts exerted by the pair of springs 34, this casing may have relatively thin walls and therefore a low weight. More particularly, its two halves 1, 2 may be molded from suitable plastic material, with the joint plane constituting the median longitudinal joint plane of the casing proper, the control members 12, 29 and 38 projecting from this casing through peripheral openings consisting of registering notches formed in the central edges of these half-casings l, 2.

Moreover, the release or clutch device is particularly simple in design and operates very easily and is highly reliable.

It will be readily understood that the specific form of embodiment described hereinabove and illustrated in the accompanying drawing should not be construed as limiting the present invention, since various modifications could be brought thereto without departing from the basic principles of the invention as set forth in the appended claims. Thus, more particularly, the guide pin 45 may be dispensed with by giving to the rear extension 44 of rod 17 a shape permitting the engagement of this extension with a certain play with the underface of the lower jaw of the rear clamp.

What I claim is:

1. An apparatus for pulling and hoisting a load attached to one end ofa cable comprising a casing having detachably connected halves and openings at each end, a pair of clamps each having a pair of superposed jaws, two pairs of tightening levers with each pair of levers interconnecting one of said pair ofjaws, a first control rod axially positioned within said casing and being pivotally connected to an end of said levers of one of said clamps, a forward motion control lever having one end pivotally connected to said first control rod, a second control rod parallel to said first control rod and pivotally connected to an end of said levers of the other of said clamps and said forward motion control lever, said first and second control rods and said forward motion control lever each consisting of flat metal sheet elements, and anchoring hook extending through one of said casing openings, a link pivotally connected to said hook and said forward motion control lever at a position of said forward motion control lever. intermediate the positions where said forward motion control lever is pivotally connected to said first and second control rods, a deflecting plate carried laterally of and by one of said first and second control rods and said casing encasing the above elements and having a lateral opening adjacent said deflecting plate whereby a cable can extend through the other of said end openings, through said clamps and then be deflected by said deflecting plate through said casing lateral opening upon operation of said forward motion control lever.

2. An apparatus as set forth in claim 1, wherein said first control rod has a pair of parallel indentical flanges, a pin connectes said flanges at one end, a roller is rotatable on said pin, said second rod is positioned between said flanges and has an elongated operture in which said roller is positioned for rolling therealong whereby said first and second control rods guide each other in their movements towards the ends of said casing.

3. An apparatus as claims in claim 2 wherein said second control rod has an extension, a member is connected to said first control rod alongside said extension, pins pivotally connect said first control rod to the ends of said levers of said one of said clamps and said extension extends between said pin whereby said extension is guided in its movement by said first control rod member and said pins.

4. An apparatus as claimed in claim 3 including a reverse motion control lever pivoted at one end to tightening levers of said one of said clamps, a link is pivotally connected to an intermediate portion of said reverse motion control lever and to tightening levers of the other of said clamps, at least one tie-rod has one end secured to said reverse control lever, a clutch control rod is capable of moving axially within said casing and has the other end of said tie-rod slideable therein, a control knob on said clutch control rod, positioned exteriorly of said casing, a compression spring disposed along said tie-rod between said reverse control lever and said clutch rod, and means projecting from said casing and capable of engaging said clutch control rod for locking the same in a spring compressing position.

Claims (4)

1. An apparatus for pulling and hoisting a load attached to one end of a cable comprising a casing having detachably connected halves and openings at each end, a pair of clamps each having a pair of superposed jaws, two pairs of tightening levers with each pair of levers interconnecting one of said pair of jaws, a first control rod axially positioned within said casing and being pivotally connected to an end of said levers of one of said clamps, a forward motion control lever having one end pivotally connected to said first control rod, a second control rod parallel to said first control rod and pivotally connected to an end of said levers of the other of said clamps and said forward motion control lever, said first and second control rods and said forward motion control lever each consisting of flat metal sheet elements, and anchoring hook extending through one of said casing openings, a link pivotally connected to said hook and said forward motion control lever at a position of said forward motion control lever, intermediate the positions where said forward motion control lever is pivotally connected to said first and second control rods, a deflecting plate carried laterally of and by one of said first and second control rods and said casing encasing the above elements and having a lateral opening adjacent said deflecting plate whereby a cable can extend through the other of said end openings, through said clamps and then be deflected by said deflecting plate through said casing lateral opening upon operation of said forward motion control lever.

2. An apparatus as set forth in claim 1, wherein said first control rod has a pair of parallel indentical flanges, a pin connectes said flanges at one end, a roller is rotatable on said pin, said second rod is positioned between said flanges and has an elongated operture in which said roller is positioned for rolling therealong whereby said first and second control rods guide each other in their movements towards the ends of said casing.

3. An apparatus as claims in claim 2 wherein said second control rod has an extension, a member is connected to said first control rod alongside said extension, pins pivotally connect said first control rod to the ends of said levers of said one of said clamps and said extension extends between said pin whereby said extension is guided in its movement by said first control rod member and said pins.

4. An apparatus as claimed in claim 3 including a reverse motion control lever pivoted at one end to tightening levers of said one of said clamps, a link is pivotally connected to an intermediate portion of said reverse motion control lever and to tightening levers of the other of said clamps, at least one tie-rod has one end secured to said reverse control lever, a clutch control rod is capable of moving axially within said casing and has the other end of said tie-rod slideable therein, a control knob on said clutch control rod, positioned exteriorly of said casing, a compression spring disposed along said tie-rod between said reverse control lever and said clutch rod, and mEans projecting from said casing and capable of engaging said clutch control rod for locking the same in a spring compressing position.

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