US3240474A

US3240474A - Hoisting winch

Info

Publication number: US3240474A
Application number: US128096A
Authority: US
Inventors: Garnier Georges
Original assignee: DBA SA
Current assignee: DBA SA
Priority date: 1957-09-26
Filing date: 1961-07-31
Publication date: 1966-03-15
Anticipated expiration: 1983-03-15

Description

March 15, 1966 G. GARNIER 3,240,474

HOISTING WINCH Original Filed Sept. 26. 195'? 3 Sheets-Sheet 1 fig/ INVENTOR GEORGES GAR/VIE by W? 20.2224- ATTOR/VE KS March 15, 1966 5. GARNIER HOISTING WINCH 3 Sheets-Sheet 2 Original Filed Sept. 26. 1957 INVENTOR 5E0/P6'E5 GA'RN/ER b 767.4%? 20% ATTORNEYS United States Patent C) Georges The present invention relates to a hoisting winch and, in particular, to a winch mounted on aircraft, such as helicopters, and is a division of the pending application Serial No. 868,508, now Patent No. 3,005,622.

In the present application, priority is claimed of the French application as filed in the above parent application.

It is an objectof the invention to provide means ensuring slow operation when hoisting in the absence of a load on the cable, that is, when the unloaded hook is being raised or when slack is being taken up after the load has been fixed to the cable, normal operation being automatically resumed as soon as the load is applied.

Further features and advantages of the invention will be apparent from the following description of one embodiment of the invention with reference to the accompanying drawing, to which the invention is in no way limited.

, In the drawing:

FIG. 1 is an assembly diagram of the essential circuits, pipe lines and members of the winch when operating to raise the cable;

FIG, 2 is an axial cross-sectional view of a winch according to the diagram of FIG. 1;

p FIG. 3 is a cross-sectional view along line III-III of FIG. 2; r 7. FIG. 4 is a cross-sectional view along line IV- IV of FIG. 2;

'= FIG. 5 is a cross-sectional view along line V-V of FIG. 2;

. FIG. 6 is a cross-sectional view along line VIVI of FIG. 2;

."FIG; 7 is a cross-sectionalview along line VIIVII of FIG. 2.

f The 'winch shown in the figures comprise, inside a body or casing 1, areversi-ble volumetric pneumatic or air motor 2 of the type having blades 3 centered on a shaft 4 which is. co-axial with the part 5 of the winch body and drives an eccentric rotor 6 through which the blades 3extend through the medium of guides 7. The output shaft 8, fixed to and co-axial with the rotor 6, carries at its end a gear 9in mesh with two

gears

10, 10 mounted on. roller bearings 11, 11' carried by the body of the winch, A crown gear 12, the gears 10, 10' and the gear 9 constitute a speed-reducing planetary gear train. The output gear 12 of this first gear train is rigidly connected by a plate 13 to a centralshaft 14 which extends through the winch body and is co-axial with the rotor 6 of the motor.

The pulley 15, which winds or hoiststhe cable 4, is co-axial with the shaft 14 and is supported by a single roller bearing 16 mounted on the body 3 in the midplane of the pulley. The pulley comprises an inner gear ring 17 which forms with the

gears

18, 18, journalled on parts integral with the winch body 1, and the central gear 19 a second speed-reducing planetary gear train. The shaft 14 transmits motion to the central gear 19 of the second train through an automatic cable descent control brake. of the screw and nut connection type. This automatic brake comprises a nut 22 which is so mounted 3,240,474 Patented Mar. 15, 1966 ice as to be capable of screwing itself along the shaft 14 and is at its right end rigid with the central gear .19. Disposed between a flange 23 on the nut 22 and a flange 21 on the shaft 14 is a flat-disc self-tightening device. The latter comprises a ratchet wheel 24 which is freely rotative on the nut 22 and is capable of being clamped or gripped between the flanges 2 1 and 23 which are provided with friction liners 25 and 26 respectively. Co-opcrating with the teeth of the ratchet wheel 24, are six pawls 27 having springs 28 radially disposed in the body 3 in such manner that the wheels 24 cannot rotate more than a fraction of a tooth without pawl engagement.

The hoisting winch operates in the following manner:

When hoisting the load, the shaft 14, driven by the motor 2 through the planetary gear train, 9, 10, 12, rotates in such direction that it is screwed into the nut 22. The latter therefore moves toward the left (as viewed in 'FIG. 2) and exerts pressure on the ratchet wheel 24 and the flange 21. Thus, the automatic brake rotates bodily while the pawls slide over the teeth of the ratchet wheel v24, which rotates in the direction of the arrow in FIG. 4. The automatic brake is therefore inoperative and rotates bodily about its axis. When the load moves downwardly, the motor 2 has only to release or untighten the brake, the loading having a natural tendency to descend. The shaft 14 rotates to unscrew itself relative to the nut 22 and the latter rotates in a direction to screw itself along the shaft 14. The ratchet wheel 24, which has a tendency to rotate in an opposite direction to the arrow, (see FIG. 4) is held stationary by the pawls 27. When the motor 2 stops, the brake is re-tightened and the descent of the cable or load also ceases. During the unloaded descent of the cable, the driving dogs 122 ensure that the pulley 15 rotates in the required direction.

A drive connection 29 is provided coaxially of the pulley 15 to permit winch operation without starting up the motor. The motor is driven at the same time as the pulley and, in this case, rotates under no load.

As can be seen on the diagram of FIG. 1, the motor 2 is supplied with compressed air through two air circuits or pipe lines, one of which is a large-section line which is the actual air supply line of the motor and comprises an air supply pipe 30 which is connected in the presentlydescribed embodiment to the air compressor of the turbine of the aircraft on which the winch is mounted. A cock 31 disposed in this supply pipe 30 regulates the air suppliedand thus regulates the rotational speed of the motor and the pulley of the winch. This supply pipe 30 is connected to a pneumatic or air distributor 32 which comprises two

valve bodies

33, 34 which permit, when they are open, the air supplied to arrive either by way of the

pipe

35 or 36 respectively through the aperture 37 shown at the upper right part of the motor 2 or at the aperture 38 shown at the upper left part of the motor respectively. These two

main valves

33, 34 are urged against their seating by

springs

39, 40 respectively and are controlled by

pistons

41, 42 having

needle portions

43, 44 respectively subjected to the action of return springs 45, '46. These two

pistons

41, 42 are coupled by a lever 47 pivota'bly mounted at its centre so that the

valves

33 and 34 cannot be opened simultaneously. The two bodies of the coupled valves intercommunicate, at their right part (see FIG. 6), on line with the supply pipe 30, by way of the aperture 48 and at their left' part, in line with the lever 47, by way of the aperture 49 which communicates with the atmosphere by way of the apertures 50, 51. The enlarged port-

ions

52, 53 respectively at the rear of the

needle portions

43, 44 close the

passage apertures

54, 55 respectively when the

pistons

41, 42 are at the end of their travel toward theright and open these apertures as soon as they are mid-way of their travel, so

that, in particular, when the two

valves

33, 34 are closed (FIG. 6), the

pipes

35 and 36 communicate with the atmosphere. At the rear of the distributor are connected the

pipes

56, 57 of the control pipe line or circuit which will be described hereinafter, and ensures the displacement of the

control pistons

41, 42 and the

main valves

33, 34 of the distributor.

The control pipe line or circuit comprises two main electrically operated valves 58, 59 which respectively control the control pipe 56 of the valve 33 and the control pipe 57 of the ,valve 34. These two electrically operated valves are supplied with air under pressure by a pipe 60 connected to the supply pipe 36. These two valves are connected to the atmosphere by pipes 61, 62 respectively.

The electrically operated control valves are controlled by an electrical circuit comprising a source of electrical energy the poles of which are represented by the signs and in the diagram shown in FIG. 1, and-two

double switches

63, 64 placed at the disposal of an operator and the pilot and mounted in parallel. In one direction (toward the right in FIG. 1) the

switches

63, 64 close the circuit of the valve 58 and, in the other direction, they close the, circuit of the valve59.

Assuming that the control switches are in the position shown in FIG. 1, that is to say, one of them (the switch 64 of the pilot) is inclined to the left, the circuit of the valve 59 is closed and therefore this valve is excited. The corresponding valve is onthe left position in FIG. 1 and the air of the main supply pipe 30 passes through the pipe 60 into the pipe 57 and arrives behind the piston 42 which it urges toward the right. The needle portion 44 urges, through the medium of its enlarged portion or head 124, the main valve 34 toward the right at the same time as the stem 53 of this needle portion closes the aperture 55. As the piston 42 is urged to the right, the piston 41, coupled thereto by the pivotable lever 47,is brought to the left in abut-ment with the end of its cylinder in compressing. the spring 45. The aperture 54 is opened and the valve 33 is applied against its seating by the action of its spring 39. The supply of air, passing through the pipe 30, passes behind the valve 33, through the aperture 48 and enters, by way of the pipe 36, the aperture 38 at the upper left part of the motor 2 (as viewed in FIGS. 1 and The rotor 6 rotates in the direction of the arrow in FIG. 1. The air, after having passed through the motor in the same direction, issues from the upper right aperture 37 and escapes by way of the pipe .35, the aperture 54 and the aperture 50.

As has been mentioned in respect of the operation for raising the cable, moving one of the buttons of the

switches

63 or 64 in'the direction opposite to the preceding direction, causes closure of the circuit of the cablelowering electrically operated valve 58. The movements of the various members of the distributor 52 are exactly opposite to the movements just described forraising the cable, and the motor, through which passes the air entering through the aperture 37 and passing out of the aperture 38 rotates in the opposite direction so as to release the

brake

24, 25, 26 and allow the load to descend.

Since an excessive speed when the cable carries no load would cause the hook to strike against and damage the aircraft, and since it is advantages to take up slack without causing a shock when the slack has been taken up, there is provided a slow-operation device which utilizes the internal pressure variations in the air motor, which pressure is proportional to the load on the hook. To this end, there is provided a pressure-operated contact 65 formed by a diaphragm 66 (FIG. 5) which is subjected, on one side, to atmospheric pressure and, on the other, to the pressure of the air at a point 67 of the motor 2 situated in the vicinity of the aperture 38 and by a switch .68 series connected to the electric supply circiut of the 4 valve 59 and a slow-operation electrically operated valve 69 connected in parallel with the valve 59.

It will be seen that when the contact 65 has detected the absence of a load, that is, when the hook raises no load or, when starting up, when taking up slack on the cable attached to a load, the switch 68 is open and the main valve 59 is not excited; only the slow operation valve is excited. The motor control air passing through the pipe 60 is directed by the slide of the valve 69 to the pipe 57, by way of the pipe 70, the pipe 57 connecting the main raising valve 59 to the distributor 32. As the slide of the valve 59 is in the right position of its travel, the pipe 57 is put into communication with the escape pipe 62. But a jet 71 is placed in this escape pipe so that the control piston 42 is not subjected on its left face (FIG. 1) to the total pressure of the pipe 30, as occurs when the valve 59 is excited, but merely to a reduced pressure, whereby the movement toward the right of the piston 40 and the needle portion 44 is just sufficient to open only a valve 72 provided in the centre of the main valve 34 and whose stern 125 protrudes from the front face of the valve 34. The air supply arriving behind the latter passes through an air vent 126 '(FIG. 6) and the supply of air to the motor is, in this case, reduced, the same being true of the speed.

When the load increases, or when the cable is rendered taut by its load, the pressure increases in the motor 2 and the pressure-operated contact 65 closes the exciting circuit of the valve 59, which causes the main valve 34 to open and permits the full supply of air through the aperture 38. Thus the winch is put into operation in two stages.

When the buttons of the

switches

63 and 64 are in their neutral position, the three valves 58, 59 and 69 cease to be excited; the slides of these valves resume the position of rest under the effect of the springs of these valves. The control air escapes to the atmosphere and, as a consequence, the

main valves

33, 34 and the auxiliary valve 72 are once more closed. The

pipes

35 and 36 also communicate with the atmosphere through the pipe spaces 54, 55 (FIG. 6).

To permit starting up and stopping the winch with a load which does not result in a great dynamic overload on the aircraft, two progressive operation screws 73, 74 are placed in the lowering control line 56 and the raising control line 57, so that the harsh action of the electric control is tempered by the pneumatic braking produced on the control air circulation, by these screws, which permit a suitable adjustment.

The cable withdrawing device comprises a roller 75 having a fixed axis of rotation and a roller 76 which is pivoted at 78 to the body of the winch and is biased by a spring 79 (FIG. 3) toward the other roller so as to exert pressure on the cable passing between these rollers. The latter are driven by a device comprising gears and two free-wheels. This gear device comprises two

co-axial gears

80, 81, the smaller gear 80 meshing with a crown gear 82 provided on one of the sides or cheeks of the winch pulley 15. Meshed with the gear 81 is a gear 83 mounted on one end of the spindle of the roller 75. At the other end of this spindle, a gear 84, having the same spindle and the same diameter as the gear 83, meshes with a gear 85 rigid with the spindle of the other roller 76. A free-wheel 86, 86 (FIG. 2) is provided in the spindle of the gear 81 and a free-

wheel

87, 87 is provided on the spindle of the

gears

83, 84. The freewheel 86, 86' comprises a ratchet wheel 86 keyed to the spindle of the gear 80 and a pawl 86 rigid with the gear 81. The free-

wheel

87, 87 comprises a ratchet wheel 87 rigid with the gear 83 and a pawl 87' having a fixed pivot'axis. Thus, when the cable descends, the gear 82 drives the gear 80 and therewith the ratchet wheel 86 in a direction opposite to that of the arrow (FIG. 7). Rotation of the ratchet wheel 86 drives the pawl 86' and, therewith, the gear 81 in the same direction. The

gear 83, which is in mesh with the gear 81', therefore rotates in the direction opposite to that of the arrow, the teeth of the ratchet wheel 87 sliding past the pawl 87". The two

rollers

75 and 76 pull on the cable 130.

When the cable is being hoisted up (directions of the arrows in FIG. 7), the gear 80 and the ratchet wheel 86 rotate without driving the pawl 86 and thus without driving the gear 81. The gear 83 is therefore not driven by the pulley, and the cable cannot drive the rollers, owing to the ratchet wheel 87 which is held stationary by the pawl 87'.

The foregoing arrangement permits, when the cable descends, rotating the pressure-applying

rollers

75, 76 by means of the pulley at such speed that they always exert a traction on the cable for withdrawing it from the pulley and, when hoisting the cable, those rollers ensure that the cable is not wound on the pulley in a disorderly manner, even when there is no load on the cable, the free-

wheels

86, 86', 87, 87' preventing any rotation of these rollers. The spring 79, which urges the rollers together, provides the necessary frictional contact between the rollers and the cable. These rollers have sufiicient hardness so that they have a suitably long life. Provided in the part of the winch through which the cable is -unwounded from the pulley, is a guide 88 which is placed perpendicular to the rollers and ensures that the cable enters or issues from the winch in a normal manner without need for the aircraft carrying the winch to be perfectly vertical. The aircraft could be inclined as much as 30 from the vertical.

To permit an easier use of the winch and, in particular, to allow automatic slowing down when the loaded hook reaches the upper point of its travel, for instance near the door of an helicopter, the diameter of the cable is slightly increased as at 89, which is, indeed, any point of the cable. When the enlarged part 89 of the cable comes between the pressure-

rollers

75 and 76, it forces the roller 76 pivotally mounted about the axis 78, to move and to make the valve 90, urged by spring 91 (FIG. 1) to slide (towards the left on FIG. 4, on the right on FIGS. 1 and 3). This valve 90 is connected, by the pipe 92 to the supply pipe 30, by pipe 93 to the open air, and, by pipe 94, to the rear part of slowing down valve 95 which, when sliding towards the left, reduces the section of. passage of air supplied in the raising operation of the cable. When the part 89 of the cable makes the roller 76 to move away from the roller 75, and therefore the valve 90 to slide, the air is supplied through the

pipes

92 and 94 at the rear of the valve 95 and pushes it back thus reducing the cross-section of the passge of air supply, and therefore slowing-down the raising of the hook. An aperture 120 is provide-d in the body of the valve 95 to permit the approach of the hook at a reduced speed.

At the end of the raising travel, a disc 96, provided close to the hook, actuates a button 97 which, when moving upwards, (see FIGS. 1 and 3) against the action of a spring 98, put the air supply pipe 58, which controls the main raising valve, into communication with the open air, through the pipe 99 connected to said pipe 57. The Winch stops then for good.

To ensure an automatic stop of the winch when the cable is completely unwound, it is provided a roller 100 (see FIGS. 1 and 4) of same width as the pulley 15 on which the cable is wound. Said roller 100 is mounted at the end of a lever 101 pivoting around axis 102 and urged upwardly by spring 103 acting on a small rod 104 pivotally connected to the lever 101. Thanks to the spring 103 and to the rod 105, the roller 100 is permanently pressed against the cable. Said roller 100 thus measures the outside diameter of the pulley with the cable wound mounted in series on the operating control circuit of the electro-valve 58 (see FIG. 1) the winch stops in the down travel.

There is further provided a safety switch 109 (FIG. 1) which permits short-circuiting the switch 108 provided for the end of the down travel, so that said switch be inoperative.

Thanks to said switch 109, it becomes possible, when the winch is operated in the down" direction, to unhook the cable, by not stopping the motion of the winch at the end of the normal travel. When the cable is entirely unwound and that, therefore, the pulley 15 still rotates in the down direction, the cable will tend to be wound up in the reverse direction and the sole anchoring screw 110 (FIG. 4) adapted to be easily borken, will allow the cable to become completely free.

At the lower part of the winch, and immediately before the exit of the cable, is provided a device for rapidly cutting the cable, which comprises a cutter 111 (FIGS. 1 and 3) cutting the cable against a fixed part 112. The cutter 111 is mounted in a cylinder 113 and is used as a piston. It is submitted to the pressure of gases produced by the combustion of a charge of powder 114 ignited by an electric firing-tube 115. The electric circuit of said firing-tube can be closed by the switch 116. A pin 121 holds the cutter 111 at the beginning of the combustion of the charge 114 and permits the full use of the energy produced during a very short stroke. A vent 123 allows for the outlet of the combustion gases. The cutting of the cable is instantaneous, even when the cable is moving in front of the cutter 112.

To permit the use of the winch, even when the latter has been stopped, during atmospheric circumstances liable to cause an inner or outer deposit of rirne on the winch, the latter is partially surrounded with a casing 117 into which can be blown hot air, for instance air coming from the airplane engine. This air can be blown permanently through a jet 118 of small cross-section into the protecting casing of the winch, so as to produce a heating as quick as necessary. A cock can be inserted on the air-supply pipe to stop said supply.

What I claim is:

A hoisting winch having a pulley, a cable wound on said pulley, a reversible pneumatic motor driving said pulley, a cable raising valve and a cable lowering valve for controlling the supply of air under pressure to the said motor, an auxiliary cable raising valve for reduced supply of air under pressure to the said motor when under no load, a pressure activated switching device responsive to the internal pressure of said motor, said switching device actuating only said auxiliary valve when said cable is not loaded.

References Cited by the Examiner UNITED STATES PATENTS 1,517,503 12/1924 Hansen 9129 2,246,910 6/1941 Amtsberg 9159 2,247,201 6/1941 Loos 9129 2,514,045 7/ 1950 Gardenhire 254-473 X SAMUEL F. COLEMAN, Primary Examiner.

JOSEPH P. STRIZAK, Examiner.