JP2657551B2 - Hoist equipment - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a hoisting device for raising and lowering a load along a cable, and more particularly to a simpler construction, lighter weight, relatively inexpensive, and less service. An improved hoist device that is simple, capable of bleach cable loading, incorporates advantageous safety features, and is highly reliable.

BACKGROUND OF THE INVENTION A traction hoist moves a wire rope (cable) up and down by creating friction between the wire rope and one or more pulleys and a drum. Current traction hoists are illustrated in U.S. Patent Nos. 4,139,178 and 3,944,185. These hoists include motors, transmissions, cable driven pulleys, cable pulleys, pressure application chains, and a number of brake mechanisms. All of these main components are mounted on the same skeleton-a large casting, the drive pulley is radially stationary and the chain moves to bias the cable.

Prior art hoists generally operate in a satisfactory manner, but the mechanisms involved are heavy, complex, and require relatively many moving parts. As a result, such devices are expensive and require significant service and maintenance. Threading a cable through many prior art hoists is a time consuming process as it may involve passing a large amount of cable through the hoist. Unnecessary large forces pushing the cable against the drive pulley cause the cable to undergo excessive wear. Thanks to the attachment to the whole frame, the force of the drive pulley can be transmitted to the gearbox and the gearbox shaft. This is especially true for overload (cantilever)
Hung) is particularly important in situations where damage to these expensive parts may result (requires heavier gearboxes and shafts as a precautionary measure). Although prior art devices employ safety brakes, they typically serve as a function of the speed of cable operation, ie, overspeed braking. However, it is also desirable to automatically brake the system in overload and underload conditions.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an improved hoisting apparatus that is simple to configure, inexpensive, lightweight, easily inspected and serviced, and reliable.

It is another object of the present invention to provide a hoist that allows for bleach loading of cables.

It is yet another object of the present invention to provide a hoist for adjusting the amount of force that the cable holds against the drive pulley.

It is yet another object of the present invention to provide a hoist that eliminates the cantilever load of a gearbox.

Another object of the present invention is to provide a hoist which is modular and consists of two main parts instead of one whole part, the two main parts being individually lighter or handling than one whole part. Is easy.

Finally, another object of the present invention is to provide a hoist having effective safety braking means, including one means for responding to overload and underload conditions.

Briefly, in accordance with the present invention, there is provided a hoist arrangement for moving a load along a cable, including a frame, cable biasing means, and a pulley. The cable biasing means is mounted on the frame. The pulley is movably connected to the frame and is free to move relative to the frame within a limited range of approaching and moving away from the cable biasing means. The pulley has a circumferential groove for receiving the cable. The cable biasing means biases toward the cable channel when the pulley is positioned adjacent to the cable biasing means. The pulley is movably positioned with respect to the cable biasing means as a function of cable tension. Preferably, the cable biasing means includes two pressure rollers and two rim rollers for dividing the load of the cable biasing means therebetween. The cable biasing means can be rigidly mounted to the upper frame so that it does not move up and down regardless of the pressure between it and the cable. Alternatively, the cable biasing means may include a roller assembly and a shaft movable relative to the spring at a distance proportional to the cable tension. The positioning of the roller assembly in such a situation may be used to activate the braking means or provide a measure of the load condition. Pulley positioning may be used to activate other braking means.
In one embodiment of the invention, a leaf spring acts on the cable biasing means to allow the motor to pass the cable around the pulley.

Other objects and advantages of the present invention will become apparent upon reading the following detailed description and upon reference to the drawings.

While the invention will be described in connection with preferred embodiments, it will be understood that it is not intended to limit the invention to these embodiments. On the contrary, the intent is to cover all alternatives, modifications and equivalents included within the spirit and scope of the invention as defined by the appended claims.

DETAILED DESCRIPTION OF THE INVENTION Referring to FIGS. 1, 2, and 3, there is shown a hoist apparatus of the present invention, indicated generally at 10, surrounded by a housing 14. FIG. Hoist 10 is drivingly associated with cable 12. Cable 12 is typically a flexible steel wire rope having a diameter based on the maximum load to be lifted. By convention, another cable ("slack rope") 16 is also used as part of the hoist as a safety device. The cable 16 passes through a safety brake means 18, which in certain situations, such as underload conditions, such as occurs when a load is accidentally lowered onto a building obstacle, disconnection of the cable 12, etc. The brakes work automatically. The cable 12 is interconnected with the safety brake in the form of an overspeed governor means 20. Means 20 stops the hoist 10 from descending when the downward speed of the hoist 10 with respect to the cable 12 exceeds a predetermined maximum value. After the cable 12 has passed through the braking means 20, the pulley 22 is wound around the
From the housing 14.

The pulley 22 is part of a lower assembly consisting of a motor 26, a gear box 28 and a lower frame 30, preferably in the form of a casting. The pulley 22, the motor 26, and the gear box 28 are mounted on a casting 30. Attached to the motor 26 via the clamp 32 is an electrical control box 34. The cover 36 is a box 34 with a flange 38
Connected to. Associated with the control box 34 is a switch 40 and an emergency stop button 42. The switch 40 controls the direction of rotation of the motor output, which results in the hoist 10 moving up or down. Button 42 turns off power to motor 26 and can also be used to manually (by lever) drive brake 20.

The hoist 10 also includes an upper assembly consisting of a frame 50, a cable biasing means, indicated generally at 52, a braking means 20, and a braking means 18. Cable bias means 52
The brake means 20 is connected to the side surface 53 of the frame 50, and the brake means 18 is connected to the side surface 54 of the frame 50.

Referring to FIG. 4, FIG. 5, FIG. 6, FIG. 7, and FIG. 8, a first embodiment of the present invention is shown. Cable 12
Is fixedly connected, for example, to a stable point in the building and passes down through a bush 56 in an opening 57 in the upper wall of the housing 14. Upon entering hoist 10, the cable passes through overspeed governor means 20. Such means are disclosed in U.S. Pat.
Nos. 185 and 4,139,178, the specifications of which are incorporated by reference. In essence, the cable 12 is gripped between the brake cam and the stop, and when the cable speed through the hoist exceeds a predetermined limit, the cable 12 through the hoist 10
Brake the movement of When the brake cam exceeds the limit, it is moved to the gripping position.

After passing through the governor means 20, the cable 12 is received in a circumferential groove 58 on the circumference of the pulley 22. The cable 12 passes almost completely around the groove 58 and over the branch block 24, the cable 12 is led out of the groove 58 and exits the housing 14. The branch block 24 is attached to the casting 30 and has its own grooved channels (not shown) to guide the cable 12 out of alignment with the groove 58. Rigid stationary cable guide
60 is concentrically positioned around the lower portion around the pulley 22. The cable guide 60 is an integral part of the casting 30,
Alternatively, it can be another member (preferably for activating bleach loading) that is removably mounted on the casting 30. The cable guide 60 guides the cable 12 around the periphery of the pulley 22 when the cable 12 is first passed through the hoist 10 and also prevents it from exiting the groove 58 when the cable 12 is not under tension.

In this embodiment, the cable biasing means 52 is
Including a roller assembly rigidly connected to 50. Two pressure rollers 62 mounted for rotation are shown between two triangular brackets 64 and 65. Although one pressure roller can be used, two are preferred to divide the applied load between them (when the pressure roller 62 compresses the cable 12 against the pulley 22 as described below). . The compression roller 62 is mounted on an axle 66 fastened to brackets 64 and 65. There is a spacer 68 on each side of the pressure roller 62. Assembly is framed by bolt 70
Fixed at 50. Spacers 72 and 74 are each bracket
Bolt between 64 and 65 and bracket 65 and frame 50
Mates around 70. Pressure roller 62 has a grooved perimeter adapted to engage the outwardly facing surface when cable 12 is received in groove 58 of pulley 22.

5 to 7 show the movable connection of the frame 50 to the casting 30. The casting 30 has an integral upwardly extending flange 76 with a vertically extending slot 78 therein.
The shoulder bolt 80 connected to the frame 50 has a slot 78
Fits inside. Washers 82 hold bolts 80 in slots 78. This connection allows the lower assembly (casting 30 / pulley 22 / motor 26 / gearbox 28) to be limited within a limited range, ie, the length of movement of the bolt 80 in the slot 78 (frame 50 / cable biasing means 52). ) Is movable up and down with respect to

A plurality of guide members are used to prevent rotation of the lower assembly and maintain vertical alignment of the upper and lower assemblies. Flanged to the casting 30 are two hollow guide blocks 84. Mounted within the inner diameter of each block 84 is a guide pin 68. Frame 50 has a pair of tubular guide block flanges 88
There is. Each of the flanges 88 has a central inner diameter 90 that is longitudinally aligned with the pins 86 and is dimensioned for receiving. A bush 92 can be fitted within the inside diameter 90 of each flange 88 to facilitate movement of the pin 89. It should be understood that pin 86 moves up and down within flange 88 with the relative up and down movement of the lower and upper assemblies. This serves to maintain the vertical alignment of the upper and lower assemblies without impeding such relative vertical movement.

In operation of this embodiment, a load such as a scaffold that carries personnel and equipment along the surface of the building is attached to the frame 50 and moves the upper assembly and more specifically the cable biasing means 52 vertically toward the lower assembly. Press Similarly, the tension in the cable 12 pushes the lower assembly and more particularly the pulley 22 vertically toward the upper assembly. As a result, the cable 12 is biased by the pressure roller 62 into the groove 58 of the pulley 22. The amount of force in the cable 12 is proportional to the tension in the cable 12. Due to the biasing force pushing the cable 12 into the groove 58, the frictional force between the cable 12 and the pulley 22 increases and the pulley
Prevent slippage between 22 and cable 12. In this manner, the rotational movement of pulley 22 is translated into up and down movement of hoist 10 along cable 12.

Many advantages of the present invention should now be understood. The hoist 10 is simple to construct, inexpensive, lightweight, has relatively few moving parts, is simple to service, and reliable. Easy bleach-loading by separating or separating the upper and lower assemblies (this also simplifies service, handling and maintenance). The cantilever load of the gearbox shaft is eliminated so that all longitudinal forces and cable tension from the cable biasing means are absorbed by the pulley 22 rather than transmitted to the gearbox. Because the force of the cable 12 is proportional to the load being lifted, lighter loads place less pressure on the cable 12 and increase the useful life of the cable, and the traction is adjusted upwards by the load, thus increasing the risk of cable slippage. Is reduced and there is insufficient traction to force the damaged cable movement, thereby reducing the possibility of rope jam during threading / unloading.

5 and 8 also show an advantageous slack rope brake. Pinned to the upper edge of the casting flange 76 is a link 91, which is connected to another link 89. Link 89 is suitably mechanically connected to slack rope brake 18. The braking means 18 preferably has a cam and a stop member between which the cable 16 passes, like the braking means 20. However, instead of the cam and stop having a cable speed dependent mechanism that drives the braking means 18 to clamp the cable 16, the cam is moved by the movement of the link 89, which allows the cam to be positioned directly. Moved easily into position.
Thus, the downward movement or position of the pulley 22 due to the lack of tension in the cable 12 positions the brake cam of the means 18 to move (or leave) the link 89 down in its clamp or brake position. Overall, this braking system is simpler, lighter in weight, and allows for a wider range of braking in appropriate situations.

A second embodiment of the present invention is shown in FIGS. 9a and 9b. Here, the cable bias means 93 includes a rim roller 94. A rim roller 94 (shown in more detail in FIG. 12) is mounted for rotation between a pair of bell crank brackets 96. The rim roller 94 is mounted on an axle 98 fastened to a bracket 96. Spacer between rim rollers 94
There is a 100 which positions the rim roller 94 to press against both outer edges of the groove 58 while bridging the groove itself and the cable 12. Alternatively, one rim roller with a central groove works equivalently. The bell crank bracket 96 has brackets 64 and 65 and an end opposite to the end where the rim roller 94 is connected.
The bracket 97 is stopped by brackets 64 and 65 by an axis 97 passing through 96. The shaft 97 is clamped (not shown) at both ends outside the bracket 96. The only connection of the cable biasing means 93 to the frame 50 is made pivotally at 102.

The main advantage of the cable biasing means 93 is that it allows adjustment of the pressure of the cable 12. In FIG. 9a, there is minimal cable tension and only the pressure roller 62 contacts the cable 12. The cable 12 is shown projecting out of the groove 58 under such circumstances. However, as cable tension increases and cable biasing means 93 and pulley 22 are moved toward each other, cable 12 is compressed between cable biasing means 93 and pulley 22 and biased in groove 58. Here the force on the cable 12 is taken by the rim roller 94 and
It is reduced by the amount of load absorbed by the rim on the pulley 22. The allocation of force between the pressure roller 62 and the rim roller 94 can be determined by the opposing arm length of the bell crank bracket 96. Therefore, if the arm length from the axle 98 to the connection 102 is smaller than the arm length from the shaft 97 to the connection 102, as shown, the rim roller 94
The force directed at is proportionally greater. Preferably, about two thirds of the force is directed to the rim roller.

FIG. 10 shows a third embodiment. 9a, but with overload mechanism and connection to frame 50 (bracket
113 and 116 only). A hollow block 110 is connected between the brackets 96. Block 110 supports shaft 112. Shaft 112 is vertically movable between aligned holes in brackets 113 and 116. Bracket 113 acts as a stop for movement above and below shaft 112. Mounted about axis 112 is spring 114. A spring 114 is located between the support bracket 116 and a plate 118 that is pinned to the shaft 112 at 119. Mounted on the plate 118 for movement therein is a rod 120 having an enlarged end 122. The position of the rod 120 is a measure of the load condition and can be advantageously used to indicate or act on overload and / or underload conditions. Thus, in an overloaded condition, the bracket 96 moves upward to overcome the tension of the spring 114 and move the rod 120 upward (the degree of which depends on the magnitude of the load), and the end 122 is connected to the lever 123 of the switch 124. To make contact. Switch 124 is for motor 2
Can be used to turn off power to 6. Similarly, another switch (not shown) located beneath rod 120 can be used to turn off motor power in a downward direction under underload conditions. Alternatively,
Switch 124 can be used to activate the braking means.

FIG. 11 and FIG. 12 show another embodiment. Here the brackets 96 are connected together or to a lever 132 by a shaft 130. Lever 132 is pivotally connected to frame 50 by bolts 134. Bolts 134 are spaced from frame 50 by bushes 136 to allow rotation of lever 132. The lever 132 serves to increase the transmitted movement of the bracket 96, but has an upwardly projecting knob 138 that is contacted by a spring-loaded plug 140. Plug 140 is biased against knob 138 by leave spring 142.
The leave spring 142 biases the lever 132 downward, which exerts pressure on the roller 62 and the pressure roller 62 biases the cable 12 into the groove 58 even when the cable 12 is not tensioned. This creates sufficient traction to allow the lifting (or unloading) of the cable 12 and the lifting of the unloaded hoist 10 until the load begins to be raised. A number of disc springs 144 are positioned around the hollow cylinder 146 between the bracket 148 and the lower flanged end 150 of the cylinder 146. The bracket 148 is fixed to the frame 50. The leave spring 142 and the plug 140 fit between the inner diameter 152 of the cylinder 146. Cylinder 14 through bracket 148
6 can move up or down depending on the load of the hoist 10. The load pushing the bracket 96 upward is the lever 132
It works to turn upward. This is a leave spring 14
Blocked by 2 and spring 144. If the load is large enough,
The cylinder 146 is moved upward. In the overload situation, as in the embodiment of FIG. 10, the lever 160 of the switch 162 is now activated by the head of the cylinder 146, and the power to the motor in the upward direction is turned off. Nut 164 and spacer 166, which fit around the upper end of cylinder 146, serve as a stop against downward movement of cylinder 146 (by contacting bracket 148).

FIG. 13 shows the lower assembly-pulley 22, motor 26, casting 3
0, shows the connection of the gearbox 28. The motor shaft 170 is fastened at 172 to a gearbox input shaft 174 mounted for rotation between bearings 176. The stationary shaft 175 of the gearbox 28 is connected to the casting 30 by fasteners 178 and 180. Pulley 22 is mounted for rotation with gear box 28. Suitable gears (not shown) are pulley 22
Used to connect the gearbox shaft 174 to the housing of the gearbox 28 to control the rotation of the gearbox. Cable guide 60
Is attached to the casting 30 to keep the cable 12 in the groove 58 as previously described.

FIG. 14 shows an alternative approach to mounting the lower assembly to obtain relative movement of the pulley to the cable biasing means. In this embodiment, a casting 198 that forms part of a lower assembly (pulley, motor, casting, gearbox), indicated generally at 200, is pivotally connected at 202 to the plate 204. Fastener 202 connects flange 206 of plate 204 and integral bracket 208 of casting 198. Further integral with the casting 198 is a flange 210 having a slot 212 therebetween. Bolts 214 mounted on plate 204 project through slots 212. Washers 216 hold bolts 214 in slots 212. Thus, the lower assembly 200 can pivot up or down relative to the upper frame 206 within the range of movement of the slot 212 about the bolt 214. 9a is mounted to the upper frame 206 (not shown) and the pulley of the lower assembly 200 is positioned adjacent thereto.
I.e. the lower assembly when the cable 12 is under tension
Engage 200 pulleys. A leaf spring 220 mounted on the plate 204 may be used to bias the lower assembly 200 upward to create a force in the cable 12 that passes between the pulley and cable biasing means.

Referring to FIGS. 15 to 17, another embodiment of the present invention is shown. In this embodiment, a stirrup that couples the hoist to the load is used to further stabilize the hoist. This hoist, shown generally at 250, includes the same components as the hoist 10, but with some additions and has a larger lower assembly casting, shown at 252. Identical elements of the previous embodiment are also shown for convenience. Stirrups 254 and 255 are connected to frame 50 of hoist 250 by fasteners 260 and to plant home 262 by brackets 264. Roller 262 is rotatably mounted to casting 252 at the upper extending edge of casting 252 by shaft 267 and clips 268 and 269. roller
270 is similarly mounted to the lower extending edge of casting 252 at a location opposite the upper edge. Thus, roller 266 is positioned adjacent to stirrup 255 at the upper portion of casting 252 and roller 270 is positioned adjacent to stirrup 254 at the bottom of casting 252. Mounted on stirrups 254 and 255 are vertical guide strips 280 and 282, respectively. The guide strip 280 has a vertical groove 284. Strip282
Has a vertical groove 286 as well. Roller 266 is positioned to rotate within groove 286. Similarly, roller 270 is positioned to rotate within groove 284. With roller 266
With 270 positioned in the vertical groove, they move only up and down. This is a casting 252 and a mounted pulley 22
Allow relative movement up and down the frame 50 and the cable biasing means 52. A flange stop 290 at the bottom of the strip 280 prevents separation of the lower assembly from the hoist 250 (and also limits the relative movement of the pulley 22 to the cable biasing means 52). By allowing only the up and down movement of the casting 252, the mounting of the rollers 266 and 270 in the grooved guides 282 and 280 maintains the up and down alignment of the pulley 22 and the cable biasing means 52, and The assembly is rotating, i.e. from the load again motor 26cg
From the position indicated by the rotation moment. The guide means of this embodiment may be used in addition to or as an alternative to blocks 84 and 88 with pins 86 shown in FIG.

FIG. 18 shows an alternative to using rollers 266 and 270.
This is to use a male V-shaped guide 300 and a female V-shaped guide 302. For example, V-shaped guide 300 is used in place of roller 266 and is connected to casting 252 by fastener 304. V-shaped guide 300 engages female V-shaped guide 302 (which replaces guide 282) which is connected to stirrup 255 by fastener 306. The result is the same in guide 300,
The casting 252 (and thus the lower assembly) can slide up and down within the guide 302 while preventing rotation.

Thus, it is apparent that there has been provided, in accordance with the present invention, a hoist apparatus which fully satisfies the objects, aims and advantages set forth above. Although the present invention has been described in relation to particular embodiments, it is evident that many alternatives, changes and modifications will be apparent to those skilled in the art in light of the foregoing description.
It is therefore intended to include all such alternatives, changes and modifications that fall within the spirit of the appended claims.

[Brief description of the drawings]

FIG. 1 is a perspective view of an improved hoist device. FIG. 2 is a side elevational view of the hoist of FIG. 1 with portions shown broken away. FIG. 3 is an elevational view of the other side of the hoist of FIG. 1,
Some parts are shown broken. FIG. 4 is a cross-sectional elevational view of the hoist taken along line 4-4 of FIG. 1 and illustrates a first embodiment of the present invention. FIG. 5 is a sectional elevation view of the hoist taken along line 5-5 of FIG. FIG. 6 is a partial cross-sectional side view taken along line 6-6 of FIG. 4, showing the cable biasing means of the first embodiment. FIG. 7 is a partial cross-sectional elevational view taken along line 7-7 of FIG. 5, showing details of the means for aligning the frame and pulley. FIG. 8 is a partial cross-sectional elevational view taken along line 8-8 of FIG. 5 showing further details of the frame and pulley alignment means. FIG. 9a is a detailed elevational view of the cable biasing means of the second embodiment of the present invention, with no biasing force on the cable. FIG. 9b is a detailed elevational view of the cable biasing means of the second embodiment of the present invention, with the cable having a biasing force. FIG. 10 is a detailed elevational view of the cable biasing means of the third embodiment of the present invention, showing the sensing means cooperating with the cable biasing means to drive the safety brake. FIG. 11 is a detailed elevational view of a cable biasing means according to a fourth embodiment of the present invention, wherein a detecting means cooperating with the cable biasing means and a leave spring acting on the cable biasing means for driving a safety brake. Is shown. FIG. 12 is a partial cross-sectional elevational view taken along line 12-12 of FIG. 11, showing the rim roller of the cable biasing means. FIG. 13 is a partial plan view with parts shown broken away of the motor / gearbox / pulley assembly. FIG. 14 is a partial elevational view of a motor / gearbox / pulley assembly according to another embodiment of the present invention. FIG. 15 is an elevation view of another embodiment of the present invention, showing a hoist connected to a load (platform). FIG. 16 is a side elevational view of the hoist of FIG. 15, showing the connection of the stirrup to the hoist. FIG. 17 is a partial cross-sectional plan view taken along line 17-17 of FIG. 16, showing the guide means of the upper and lower assemblies of the hoist. FIG. 18 is a detailed cross-sectional view of the alternative guide means shown in FIG. In the figure, 10 is a hoist device, 12 is a cable, 14 is a housing, 16 is a cable, 18 is a safety brake means, 20 is a governor means, 22 is a pulley, 24 is a branch block, 26 is a motor, 28 is a gear box, 30 Is the lower frame and casting, 32 is the clamp, 34 is the control box, 36 is the cover, 38 is the flange, 40 is the switch, 42 is the emergency stop button, 50 is the frame, 52 is the cable bias means, 53 and 54 are the sides, 60 is a cable guide,
62 is a pressure roller, 64 and 65 are brackets, 66 is axle, 68 is spacer, 70 is bolt, 72 and 74 are spacer, 76 is flange, 78 is slot, 80 is bolt, 82 is washer, 84 is guide block, 86 is a guide pin, 88 is a guide block flange, 90 is a central inner diameter, 93 is a cable bias means, 94 is a rim roller, 96 is a bracket, 98 is an axle, 100 is a spacer, 110 is a hollow block, 112 is a shaft, 113 and 116. Is a bracket, 114 is a spring, 116 is a support bracket, 118 is a plate, 120 is a rod, 122 is an enlarged end, 123 is a lever, 124 is a switch, 130 is a shaft, 132 is a lever, 134 is a bolt, 136 is a bush, 138 is a knob, 140 is a plug, 142 is a leave spring, 1
44 is a disk spring, 149 is a hollow cylinder, 148 is a bracket, 150 is a lower flange end, 160 is a lever, 162 is a switch, 164 is a nut, 166 is a spacer, 170 is a motor shaft, 1
74 is the gearbox input shaft, 175 is the stationary shaft, 176 is the bearing, 178 and 180
Is a fastener, 198 is a casting, 202 is a fastener, 204 is a plate, 206 is a flange, 208 is an inner bracket, 210 is a flange, 212 is a slot, 214 is a bolt, 216 is a washer, 254 and
255 is stirrup, 250 is hoist, 260 is fastener, 2
62 is a platform, 264 is a bracket, 266 is a roller,
267 is a shaft, 268 and 269 are clips, 270 is a roller, 280 and 282
Is a guide strip, 284 is a groove, 300 is a male V-shaped guide,
302 is a female V-shaped guide, and 304 and 306 are fasteners.

Claims (11)

(57) [Claims] 1. A hoist device for moving a load along a cable, comprising: a frame; cable biasing means mounted on the frame; and a cable driven pulley rotatably mounted, wherein the pulley is Mounted for movement relative to the frame within a limited range of approaching and moving away from the cable biasing means, wherein the pulley has a peripheral circumferential groove for receiving the cable, the cable biasing means comprising: Engaging the cable when positioned adjacent to the biasing means to bias the cable toward the groove;
Hoist equipment. 2. The hoist of claim 1 wherein said cable is biased toward said groove with a force dependent on the amount of tension in said cable. 3. The hoist according to claim 1, further comprising a motor, wherein said motor is connected to said pulley to selectively rotate said pulley and move with said pulley relative to said frame. 4. The apparatus according to claim 1, wherein said cable bias means is a pressure roller,
A pressure roller including two brackets and a rim roller, wherein the pressure roller is rotatably connected to the bracket between the brackets, the brackets are connected to each other, and the pressure roller is configured such that the pulley is positioned adjacent the cable biasing means. Pressed against a cable, the rim roller is movably connected to the bracket, and the rim roller is positioned such that when the pulley is positioned adjacent to the cable biasing means, it does not contact the cable but contacts the periphery of the pulley. 2. The hoist according to claim 1, wherein the load of the cable biasing means is divided between the pressure roller and the rim roller to adjust a biasing force of the cable. 5. The vehicle further comprising two bell crank brackets, wherein said rim roller is rotatably connected to said bell crank bracket between said bell crank brackets, said bell crank bracket being pivotally connected to said bracket, Each of the crank brackets has two arms of a predetermined length, one arm is connected to the bracket, the other arm is connected to the rim roller, and the relative length of the arms is the pressure roller and the rim roller. 5. The hoist according to claim 4, wherein the division of the load of the cable biasing means is adjusted between. 6. The cable biasing means includes a pressure roller, the pressure roller being pressed against a cable when the pulley is positioned adjacent to the cable biasing means, the pressure roller approaching the pulley. The pulley is movable within a limited range and includes sensor means responsive to the position of the pressure roller, and selectively controls the motor to move the pulley in a predetermined direction corresponding to the position of the pressure roller. The hoist according to claim 3, wherein the hoist stops rotating. 7. The cable biasing means is mounted to the frame in a manner such that the cable biasing means allows a limited amount of movement toward and away from the pulley,
Further comprising a motor and sensor means, the motor being connected to the pulley for selectively rotating the pulley and moving with the pulley relative to the frame, wherein the sensor means is responsive to the position of the cable biasing means. hand,
5. The hoist according to claim 4, wherein the motor is selectively controlled to stop rotation of the pulley in a predetermined direction corresponding to a position of the cable biasing means. 8. The cable biasing means is mounted to the frame in a manner that the cable biasing means allows a limited amount of movement toward and away from the pulley,
And a leaf spring acting on the cable biasing means when the tension of the cable is at a minimum, the cable biasing means being positioned such that the cable is biased toward the groove to engage the cable. 4. The hoist of claim 3, wherein said hoist has sufficient traction to allow said cable to pass around said pulley by said motor. 9. The system further comprises cable guide means mounted for movement with said pulley relative to said frame,
The guide means directs the cable around the pulley as the cable is passed through the hoist and maintains the cable in the groove when the cable becomes slack.
The hoist according to. 10. The method according to claim 1, further comprising braking means for stopping hoisting movement with respect to the cable, said braking means being activated and deactivated depending on the position of said pulley relative to said frame. Hoist. 11. The vehicle further comprising a casting, wherein the pulley is movably mounted on the casting and further includes two stirrups connected to the frame;
The pulley is positioned between the stirrups and further includes a frame guide means mounted on the casting and the stirrup, the frame guide means keeping the casting in vertical alignment with the frame. 2. The hoist according to 1.