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: 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. 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. 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. 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. 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. 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. The invention will now be explained in detail with reference to the figure, which shows a hoist clamp according to the invention, 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 2, the plates being connected with a bridge element 18 and with a block 19, which is intended for increasing the grip on a profile 11 to be hoisted. The profile 11 is when hoisted clamped between the hook parts 2, together with block 19, and a clamping catch 12, which clamping catch 12 is capable of rotating about a spindle 13. A hoisting chain 9 is connected to clamping catch 12 with the aid of a pin 14. Between the plates making up the frame part 1 a chain pulley 10 is mounted to a swiveling arm 20 and the plates comprise two indentations 4,8 each, by which two stable positions for chain pulley 10 are realized. Prior to hoisting the swiveling arm 20 can be put manually into one of two possible stable positions, whereupon during hoisting swiveling 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 swiveling arm 20 and frame part 1 is implemented as a pin 21 and slotted hole joint 22 respectively. With the swiveling arm fixed in the position represented by the dotted line in the figure, the clamp will lift profile 11 substantially without rotating it around its longitudinal axis. With the swiveling arm fixed in the position represented by the solid line in the figure, the clamp will rotate profile 11 at an angle which, when the profile is lowered onto a base, is sufficient for rotating it from a standing position to a lying position. When starting with profile 11 already in the lying position the hoist clamp evidently works the other way around. Clamping catch 12 is provided with a spring 16, for realizing a pre-tension for achieving a sufficiently strong grip before the force of the chain is optimally applied. Although spring 16 is in this realization 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. Although the explanation to the figure 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 cable pulley 10 should be read. 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. In that case bridge element 18 and block 19 can be deleted.

Claims: Hoist clamp for picking up and manipulating for instance metal profiles, comprising a frame part (1) which can be fitted to a chain (9) or a cable and a hook part (2), the frame part (1) being provided with a clamping catch (12) cooperating with the chain (9) or the cable for securing, during hoisting, a profile (11) held between the frame part (1) and the hook part (2), the frame part (1) being additionally provided with an adjustable chain pulley (10) or cable pulley for the selection of a contact point of the chain (9) or the cable on the hoist clamp, characterized in that the chain pulley (10) or cable pulley is mounted on a swivelling arm (20) which is rotatably fitted to the frame part (1) and in that the frame part (1) is provided with means (4,8) for locking the swivelling arm (20) in two stable positions. Hoist clamp as claimed in claim 1, characterized in that the frame part (1) comprises two interconnected frame plates, at the outer edges being provided with two pairs of matching indentations (4,8), into one pair of which, prior to hoisting, the chain pulley (10) or cable pulley can be placed with the aid of the swivelling arm (20), for the selection of the contact point. 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. Hoist clamp as claimed in claim 3, characterized in that means (16) are provided for the creation of a pre-tension on the clamping catch (12), prior to hoisting.

Inventors: BUSSCHERS ALFONSIUS JOHANNES M, BUSSCHERS, ALFONSIUS JOHANNES MARIA
Applicants: BUSSCHERS METAALBEDRIJF BV, METAALBEDRIJF BUSSCHERS B.V.
Application year: 1996
Main classification: B66C1
IPC codes: B66C1