Hoist clamp

Abstract

 Hoist clamp for lifting and manipulating profiles, provided with a frame part (1) and a hook part (2). The frame part (1) comprises and adjustable chain pulley (10), enabling the contact point of a chain (9) on the frame part (1) to be selected. During hoisting, the profile can thus be made to rotate about its axis or, alternatively, be prevented from doing so.

Description

[0001] The present invention relates to a hoist clamp for picking up and manipulating for instance metal profiles, comprising a frame part which can be fitted to a chain or a cable, and a hook part, the frame part being provided with a clamping catch cooperating with the chain or the cable for securing, during hoisting, a profile held between the frame part and the hook part, the frame part being additionally provided with an adjustable chain pulley or cable pulley for the selection of a contact point of the chain or the cable on the hoist clamp.

[0002] A hoist clamp of this type is known from EP-A-0 216 175. The prior art hoist clamp is of the compound type and acts in two places on the profile to be hoisted. For influencing the position of the profile about its longitudinal axis the frame part is provided with an edge in which a number of indentations have been made, into which, prior to hoisting, the chain pulley or cable pulley can be placed. This enables, when for instance transporting wide profiles along narrow galleries in mines, an optimum position of the profile to be selected at all times.

[0003] The present hoist clamp actually solves another problem in that it reduces the risks inherent in hoisting a heavy profile. More particularly, the invention prevents a profile during hoisting from unpredictably rotating about its longitudinal axis and possibly in consequence slipping loose from the hoist clamp. Additionally the invention enables a controlled rotation of the profile about its longitudinal axis to be performed, in the course of which for instance a lying H-profile is placed upright or the other way round. To this end the invention is characterized in that the chain pulley or cable pulley is mounted on a swivelling arm which is rotatably fitted to the frame part, and in that the frame part is provided with means for locking the swivelling arm in two stable positions, one in which the chain or the cable is substantially perpendicular over the centre of gravity of the profile, and a second one which is differently positioned so that a measure of rotation will occur.

[0004] An advantageous embodiment of the hoist clamp is characterized in that the frame part comprises two interconnected frame plates, provided at the outer edge with two pairs of matching indentations, into one pair of which, prior to hoisting, the chain pulley or cable pulley can be placed with the aid of the swivelling arm, for the selection of the contact point. The hoist clamp thus obtained has a low self-weight and a minimum of parts and is therefore inexpensive.

[0005] Another advantageous embodiment of the hoist clamp is characterized in that a first indentation is provided for placing, during hoisting, a previously lying H-profile in an upright position and in that a second indentation is provided for placing a previously upright H-profile in a lying position.

[0006] A still further advantageous embodiment of the hoist clamp is characterized in that means have been provided for the creation of a pre-tension on the clamping catch, prior to hoisting, preventing a profile from slipping loose from the clamp in the event of a rotation occurring before the clamping catch has been pulled sufficiently tight by the chain or cable.

[0007] The invention will now be explained in detail with reference to the following figures, of which:

Fig. 1a

shows a hoisting clamp provided with slots and indentations, lifting a large profile;

Fig. 1b

shows the same hoist clamp lifting a small profile;

Fig. 1c

shows the same hoist clamp rotating a profile;

Fig. 2

shows a hoist clamp provided with slots, which is able to lift an H-profile in both positions and rotate it to both rotation positions;

Fig. 3

shows a hoist clamp provided with indentations at the outer edge of the frame plates.

[0008] Fig. 1 shows a first type of hoist clamp built up of two identical steel plates, of which only the foremost plate is visible. Each plate comprises a frame part 1 and a hook part 1, the frame part 1 being provided with a slot 3, which in turn is provided with indentations 4,5,6,7,8 into which, for the guiding of a chain 9, a chain pulley 10 can be positioned prior to hoisting. The position of chain pulley 10 may be chosen, as appears from Figures 1a,1b,1c, depending on the size of the profile 11 and of the rotational position about the longitudinal axis in which the profile 11 is to be lifted up or into which it is to be brought. It should be noted that the indentations 4,5,6,7 are chiefly intended for handling profiles of different sizes, whereas the purpose of indentation 8 is to bring the profile into such a position that it can be tilted.

[0009] The hoist clamp furthermore comprises a clamping catch 12, which is capable of rotation about a spindle 13 and which is provided with a spring (not shown) pressing the clamping catch onto the profile 11. On the surface contacting profile 11 the clamping catch 12 is provided with notches (not shown), to prevent profile 11 from slipping back during hoisting. During hoisting, clamping catch 12 is moreover pulled down onto profile 11 by the tensile force in chain 9, the tensile force being transmitted to clamping catch 12 through a pin 14. To prevent the force with which clamping catch 12 presses on profile 11 from depending on the position of chain pulley 10, rotatable chain pulley 15 is at least for translations fixed-positioned.

[0010] Although the explanation to Fig. 1 has been given for a hoisting appliance provided with a chain, a similar explanation can be given for a hoisting appliance provided with a cable, for instance a steel cable. Then for chain pulley 10 read cable pulley 10, and for fixed-position rotatable chain pulley 15 read fixed-position rotatable cable pulley 15.

[0011] It is furthermore possible for the frame part of the hoist clamp to be composed of two identical plates with a differently composed hook part fitted to it, for instance a solid hook part fitted between the frame parts by means of screwed connections.

[0012] Fig. 2 shows a second type of hoist clamp, where slot 3 has only two indentations 4,8 for realizing two stable positions for chain pulley 10, such that position 4 will achieve a vertical lifting of profile 11, whereas position 8 will cause profile 11 to be tilted at an angle which, when the profile is lowered onto a base, is sufficient for rotating profile 11 through 90 degrees.

[0013] Fig. 2 furthermore shows how, with the aid of a spring 16, a defined pre-tension can be applied to clamping catch 12. Although spring 16 is in this instance implemented as a spiral spring, other spring types, such as leaf springs and cup springs, may also be applied. It is additionally shown how, with the aid of an array of notches 17 in clamping catch 12, an improved grip on profile 11 is obtained. It can finally be seen from Fig. 2 how, with the aid of a bridge element 18, a connection between the two identical steel plates can be realised, and how, with the aid of a block 19 the grip of hook part 2 on profile 11 can be increased.

[0014] Fig. 3 shows a third type of hoist clamp, also for the vertical lifting or the tilting of profiles, the outer edge of the plates making up frame part 1 also comprising two indentations 4,8, by which two stable positions for chain pulley 10 are realized. In this case chain pulley 10 is mounted between the plates to a swivelling arm 20, which prior to hoisting can be brought manually into one of the two possible stable positions, whereupon during hoisting swivelling arm 20 is fixed in that position through the action of chain 9 on chain pulley 10. To allow movement to at least some degree, a connection between swivelling arm 20 and frame part 1 is implemented as a pin 21 and slotted hole joint 22 respectively. Finally the third type of hoist clamp is also provided with a clamping catch 12 which is capable of rotation around a spindle 13, the force of chain 9 being transmitted to clamping catch 12 with the aid of a pin 14 with a spring 16 providing a pre-tension for achieving a sufficiently strong grip before the force of the chain is optimally applied.

Claims

1. Hoist clamp for picking up and manipulating for instance metal profiles, comprising a frame part which can be fitted to a chain or a cable and a hook part, the frame part being provided with a clamping catch cooperating with the chain or the cable for securing, during hoisting, a profile held between the frame part and the hook part, the frame part being additionally provided with an adjustable chain pulley or cable pulley for the selection of a contact point of the chain or the cable on the hoist clamp, characterized in that the chain pulley or cable pulley is mounted on a swivelling arm which is rotatably fitted to the frame part and in that the frame part is provided with means for locking the swivelling arm in two stable positions.

2. Hoist clamp as claimed in claim 1, characterized in that the frame part comprises two interconnected frame plates, at the outer edges being provided with two pairs of matching indentations, into one pair of which, prior to hoisting, the chain pulley or cable pulley can be placed with the aid of the swivelling arm, for the selection of the contact point.

3. Hoist clamp as claimed in claim 2, characterized in that a first indentation is provided for placing, during hoisting, a previously lying H-profile in an upright position, and in that a second indentation is provided for placing a previously upright H-profile in a lying position.

4. Hoist clamp as claimed in claim 3, characterized in that means are provided for the creation of a pre-tension on the clamping catch, prior to hoisting.

Drawing