FR2518076A1 - IMPROVEMENTS TO HOISTS - Google Patents

Abstract

1. A tackle comprising pulley-block means (9) having an upper block (6) carried by a frame (10) and a lower block (27) carrying a hoisting hook (15) or like member and suspended from below the upper block (6) through at least one flat flexible line (5) passing around return pulleys (4) which are carried by the two blocks (6, 27) and at least one end (23) of which is attached to the drum (21) of a drum-pulley (2) driven by a rotary driving member (1), characterized in that the upper block (6) is mounted on the frame (10) in such manner as to be freely pivotable about a horizontal axis (X-X) substantially tangent to upper parts of grooves of two successive return pulleys (4), namely that pulley (4b) carried by the upper block (6) which the flat flexible line reaches first in travelling away from the drum-pulley (2) and that pulley (4) which succeeds the last-mentioned pulley in a direction toward the drum-pulley (2).

Description

The invention relates to hoists, that is to say lifting devices

  comprising, on a chassis, a flexible link at the first end of which is attached a lifting hook or the like and on the second end of which acts a rotary motor member, of manual type, electrically

that, pneumatic or hydraulic.

  It is said above that ltl lifting hook or

  a similar member is coupled to one end of the flexible link.

  This means that such a hook can be attached either directly to this end which then hangs freely relative to the frame of the hoist, or to a block suspended from the flexible link, said end of which is then fixed to the above frame. Furthermore, by "analogous member to a lifting hook "means in particular an electromagnet, suitable for lifting ferrous masses, or a suction cup system, suitable for lifting

windows or the like.

  In the usual hoists, the flexible link is generally constituted by a catne and the rotary motor member by a nut or pulley the gobrge of which is dimpled in the form of the links of the chain e L on which the chain is wound only on a fraction of a turn Ae beyond this nut (on the side

  opposite the drain hook), the chain hangs more or less

  In a nutshell, by cluttering the space below the hoist, where it is received in a volu-minous tank which creates difficulties in housing and equilibrating the hoist In other hoists, the chain is replaced by a ro- nde but this solution

  also leads to innonvnints well known in the art

  ciens (encamrbeent, brittleness, nécces it of a cable guide) o

  The purpose of the invrion is to remedy these disadvantages.

state of the art.

  To this end, the hoist according to the invention is

  essentially characterized in that the flexible link is cons-

  formed by a flat textile strap or by a flat metallic braid and the rotary motor member by a pulley-drum made of a drum and two cheeks, and in that the aforesaid second end of the strap or braid is anchored to the drum drum pulley whose cheeks have a sufficient diameter to

  that they contain the strap or braid wound on the drum

  bour when the lifting hook or the like occupies its

  highest position in relation to the hoist frame.

  A hoist is thus obtained in which the strap or braid can be wound over a small height since the thickness of the strap or braid can be maintained, that is to say V thickness of each winding turn on the drum, at relatively low values since we

  can play on the width of the strap or braid to increase

  ment its tensile strength On the contrary, the width of a chain (measured parallel to the axis of the nut) is equal to its thickness (measured radially with respect to the nut) while its conformation prevents it from rolling up on itself in contiguous turns Analogous considerations

apply to round cables.

  We know that the loads suspended on a hoist

  are generally subject to some lateral swaying

  ral Belt or braid hoists according to the invention

  lend themselves particularly well to such a swing.

  For this purpose and in accordance with a first perfec-

  tioning of the invention, the hoist, which is provided with a hauling system consisting of an upper yoke carried by the frame of the hoist and a lower yoke suspended below the upper yoke by means of the flexible link which passes over pulleys carried by the two yokes and the aforesaid first end of which is fixed to the upper yoke, is characterized in that Raw the upper yoke is mounted on the

  chassis so that it can rotate freely on a horizontal axis

  high s zontal tangent to the parts / grooves of two successive deflection pulleys, namely the pulley of the upper yoke that the

  strap or braid reached first when arriving from the pulley

  drum and the pulley which follows it towards the drum pulley.

  Thanks to this construction, the swings

  of the suspended load result in an oscillation of the upper yoke around its horizontal axis, this oscillation simply having the effect of twisting and slightly untwisting the strap or braid without imposing on the latter lateral forces which would tend to cause it to come out various

pulleys that guide it.

23 130716

  we also know that there is interest in providing a pa-

  Load limiter lan Belt or braid hoists

  according to the invention p-stop particularly well also

  if incorporating such a safety device.

  For this purpose and conif ox kmenilt to a çl'euxîêre perf ecticn-t nemuent of the invention, the tpal Xn comprises, as a charge limiter, a disposïii; i popre to r 4 act when the voltage of at least a strand of the strap or braid exceeds an 8 eye

  predetermined, 'adjustable prezerence.

  The invention will now be described in more detail.

  tail using the mode of r 4.1 isat-0 on which is rep-re-Oenté schÈ &,

  matically to the drawings ann 1 exes.

  Figure 1 of cos drawings represents the palama con-

  form of the invention, ent vertical section longitadine IG o'elon

line I from figure 2.

  Figure 2 shows the hoist of Figure 1: elder nop by vertical planes diia Iês according to, the league 1 ld 3 fiigu Ure 1 The figure 3 re 4 eun 3 'tai of pm alare Gii vertical section along 1 F line 111 711 do le 2 igurk 3 1 Le ralan pr P-Pës I- ioer m îf-esoi 10 irde ec-e vertical flanges 16, 1 7 ui Bornt silgd à llai de, for example, dc oiot 13 that u; of a cross member 28 and (tubulafre%, Instead of being ps; u ar nechaine or a cable as in the usual hoists-s, the soeupl link of the hoist according to the invention is sonstituer pays a texytile siingle (or a metallic braid, flat 5 Consequently to be constituted by a nut or pulley alvdolée, the rotary motor member of the pal-an is constituted by a pulley-drum 2 made of a drum 21 and two cheeks 22 and housed between the two flanges 16 and 17 One end 23 of the strap is anchored, for example using a key 24; to the drum 21 of the drum pulley 2 whose cheeks 22 have a diameter D sufficient for they contain the strap 5 wound at most on the drum 21, as seen in

  section in Figure 2 (the strap 5 then leaving the pulley-

  drum 2 as shown in solid lines in Figure 1).

? 3 '13076

  The drum pulley 2 is keyed onto a shaft 25 which constitutes the output shaft (low speed shaft),

  suitably extended, of an electric gear motor 1.

  As can be seen in particular from FIG. 2, the latter, which is of the type with incorporated brake, is mounted on the external face of the flange 16 while its shaft 25 crosses the two flanges

  16 and 17 and protrudes beyond the flange 17.

  Leaving the drum pulley 2, the strap 5 passes over several return pulleys 4 and its end 26, opposite

  at the end 23, or hangs freely while supporting a hook

  lifting chet 15, or more generally is hooked to the chassis 10, in the manner described below, so that the strap 5 can support a muffle 9 with one, two or three strands, the hook 15 being then mounted on this muffle 9 This comprises an upper yoke 6 carried by the chassis 10 and

  a lower yoke 27 suspended below the yoke above

  6 through the strap 5 According to the embodiment shown, the strap 5 passes successively

  on a first return pulley 4 a whose axis is carried di-

  straight through the chassis 10, on a second return pulley

  see 4 b mounted in the upper yoke 6, on a third idler pulley 4 c mounted in the lower yoke 27, on

  a fourth deflection pulley 4 d mounted in the upper yoke

  6 and on a fifth * 4th return pulley mounted in the lower yoke 27, its end 26 being fixed to the upper yoke 6 in any suitable manner, for example using a transverse pin 34 It goes without saying that such hauling could be replaced by hauling of any other

equivalent type.

  According to an important characteristic of the invention, the upper yoke 6 is mounted on the chassis 10 so as to

  ability to rotate freely around a horizontal geometric axis

  tal XX tangent to the upper part of the groove of that 4b of the return pulleys 4 of the upper yoke 6 that the strap 5 reaches first arriving from the pulley-drum 2 as well as to the upper part of the throat of the pulley 4a which follows it towards the drum pulley 2 (see FIG. 1) This horizontal axis XX is materialized by a hinge pin 44 which passes through aligned holes, zrnages in crosspieces 19 of the upper yoke 6 thus as in the cross member 28 and in one of the tubular spacers of the chassis 10 The latter is provided, at its lower part and at the level of the lower yoke 27, with a notch 29 facilitating the d 4 lat 3 lat beats Èle the latter clevis 27. The hoist preferably comprises, as a load limit, a device 7 suitable for reacting when the tension of at least one strand of strap, in this case the strand between the pulleys 4 a and 4 b, has a predetermined scil preferably adjustable According to a construction ava ntageuse, the load limiting device 7 comprises a roller 30 which rests

  on the upper face of the strap 5 between the pulleys

being

  derivatives 4 a and 4 b, this roller 30 / guided along a vertical trajectory

  wedge (or approximately vertical) and being biased downwards by a spring 31 For this purpose, the horizontal axis of the roller 30 is carried by a rod 32 guided in a green sleeve: 33 and threaded, opposite the roller 30, so as to receive a nut and a lock nut 8 The latter zervent of supporting a cup 35, the spring 31 being a compression spring which acts on this cup 35 by reacting on the support 36 of the sleeve 33 By its free end in the form of a ramp 37, the rod 32 actuates an electrical limit switch 13 Ce

  contact 13 is monA on the motor supply circuit

  reducer 1 so as to stop the latter when the load ap.

  folded on the hook 15 protrudes from an finished eye 4, that is to say when the rod 32 is fresh I high top height 4 relative to the frame 10 -, m Ddl% l eye can be adjusted 5 using the nut and its tale - nut 8 which determines the

spring tension 31.

  The feed circuit of the gear motor 1 is completed by limit switches 38 and 39 which cooperate

  with a nut 40 mounted on the threaded free end of the rear

  bre 25 of the gear motor 1 and which respectively determine the limit positions of the hook 15, upwards and downwards are these limit switches 38 and 39 / mounted on a strip 3 inside a cabinet electric 11 mounted on the chassis 10 At the crossing of the shaft 25, this cabinet 11 can be made watertight by means of a gasket 41 It suffices to use a geared motor 1, with incorporated brake, of the explosion-proof type and to accommodate in an explosion-proof box 11 the contacts 13, 38, 39 and other electrical components of the supply circuit of the geared motor 1, to have a hoist having an explosion-proof and non-sparking character. The hoist according to the invention can be of the type placed, hung or suspended from a trolley. It is this latter possibility which has been shown diagrammatically in broken lines in FIG. 2 o a trolley 12 rolls on a monorail 42, the hoist being suspended to this carriage using hanger pins

  14, passing through the tubular spacers 20.

  A hoist is thus obtained, the strap 5 of which is

  held taut between its ends 23 and 26, by its winding

  also in successive spiral layers on the drum pulley

  2, the limits of the winding being shown diagrammatically,

  dotted line and solid line in Figure 1, by the extreme positions of the strap 5 when it leaves this

drum pulley 2.

  When the load suspended on the hook 15 tends to swing transversely, this results in an oscillation of the lower yoke 27, facilitated by the notch 29, and therefore in an oscillation of the upper yoke 6

around the horizontal axis X-X.

  When the load suspended on the hook 15 exceeds a safety threshold, the tension of the strap strand 5 comprised between the return pulleys 4 a and 4 b has, at the level of the roller 30, a vertical component sufficient to overcome the action of the spring 31 This results in an uplift of the roller 30 and of the rod 32, the ramp-shaped end 37 of which leaves the electrical contact 13, which cuts off the supply of the gear motor 1 in the direction of ascent. reduce the load to allow the spring 31 to lower the rod 32 until its end 37 returns to touch the contact 13

  and restore power to the gear motor 1.

  A hoist is thus obtained which in particular has the following advantages: low cost price; small footprint;

? 3 51 2 30? 6

  elimination of the usual cable guides absence of offset of the hook 15, between the low position and the high position of its coiarsee lifting and lowering of this hook 15 therefore being done on a perfectly vertical axis when the hoist is litilized in anti-flame type: anti or non-sparking, no risk of lethal sparks

  textile strap 5 and the r-artie≥ metalligues du -palar, (pomlie-

  drum 2, idler pulleys 4 etc) very low "headroom" dta Ceentre 1 b High hawk and hook 15 in baute position) -possibility to use -these elements -s -oor cusru a hoist with direct lifting (sar s,: chaule o lifted by 11-111 teriu-w diaire of a muffle on the strands; decrease in speed of ce 15, from sca pst high to its low position, and "ice liersa, in reason of î arlationcï progressi ,, Ye du diamété treruemn on the 22 eu The invention iov o îe pas iitea

  realization rep, -êser r L S n, -oetnts Lsrane.

  In particular, it would be o atiue atu d XX, not the only chave 6 pre, ritotl of the hoist, by ii Lr nrtie me for example, so J 3 ee: cr a good winding 11 det the strap 5 on the louse Ji Je -tambo i, and also-, d 2 cns le, Ca-s

  the most general, on the puouiies -Ie re-Z-ro 4.

? 518 76

Claims (1)

CLAIMS 1 Hoist comprising, on a chassis (10), a flexible link at the first end (26) of which is hooked a lifting hook (15) or similar member and on the second end (23) of which acts a driving member rotary, of manual, electric, pneumatic or hydraulic type, characterized in that the flexible link is constituted by a flat textile strap or by a flat metallic braid (5) and the rotary motor member by a pulley-drum (2) made a drum (21) and two cheeks (22), and in that the said second end (23) of the strap or braid (5) is anchored to the drum (21) of the drum pulley (2 ) whose cheeks (22) have a diameter (D) sufficient to contain the strap or braid (5) wound on the drum (21) when the lifting hook (15) or the like occupies its highest position relative to the frame (10) of the hoist. 2 hoist according to claim 1, which is provided with a hauling system (9) formed by an upper yoke (6) carried by the frame (10) of the hoist and a lower yoke (27) suspended below of the upper yoke (6) by means of the flexible link (5) which passes over deflection pulleys (4) carried by the two yokes (6, 27) and the aforesaid first end (26) of which is fixed to the upper yoke (6), characterized in that the upper yoke (6) is mounted on the frame (10) so that it can rotate freely along a horizontal axis (XX) tangent to the upper parts of the grooves of two idler pulleys (4) successive, namely the pulley (4 b) of the upper yoke (6) that the strap or braid (5) reaches first arriving from the drum pulley (2) and the pulley (4 a) which succeeds it towards the drum pulley (2). 3 hoist according to claim 1, characterized in that the frame (10) is mounted so as to be able to rotate freely along a horizontal axis (X-X). 4 Hoist according to any one of claims 1 to 3, characterized in that it comprises, as a load limiter, a device (7) porpre to react when the tension of at least one strand of the strap or braid (5) exceeds a predetermined threshold. Hoist according to claim 4, characterized in that the tension threshold is adjustable. 6 Hoist according to one of the e :, sendications 4 and 5, characterized in that the tension iilteur device (7) is constituted by a calect> O port A: r a movable rod? 32) and requested by ua nr = lort d 91) against a brnir of C-angle or braid (5) between - ler of '-zxeoi sc O cessivas (4 a, 4 b), the aforesaid rod (î 2? coptraet with a cotact 1 electric limit switch {13) incorporated into the feed circuit of a 4-read gearmotor: cue with ncorort brake on the output rbr (25) from which the pulbour-tarbour (2) is fixed 7 Salt hoist: n all of claims 5 and 6, characterized in that the spring {31) is provided with means (8,) for adjusting its degree of compression. 8 Hoist according to any one of claims   1 to 7, the drum pulley (2) of which is wedged on the output shaft   tie (25) of a geared motor (1) with incorporated brake, characterized in that the geared motor (1) is of the explosion-proof type and in that the electrical components (13, 38, 39) of the circuit d geared motor supply (1) are housed in a box explosion-proof (11).