US3325148A - Pneumatically-operated hoist - Google Patents

Description

June 13, 1967 E. R. POWELL 3,325,148

PNEUMAT I CALL OPERATED HOI ST Filed Dec. 27, 1965 5 Sheets-Sheet 1 I NVENTOR. [064)? A? Pan/44 47 TORA/EKS' June 1967 E. R. POWELL PNEUMATIC-ALLY-OPERATED HOIST a Sheets-Sheet? Filed Dec. 2'7, 1965 flllllqlllw TN UUT i June 13, 1967 om 3,325,148

PNEUMATICALLY-OPERATED HOIST Filed Dec. 27, 1965 5 Sheets-Sheet Big-i INVENTOR. [paw Q Pom/44 United States Patent 3,325,148 PNEUMATICALLY-OPERATED HOIST Edgar R. Powell, 7358 St. Auburn Drive,

Birmingham, Mich. 48010 Filed Dec. 27, 1965, Ser. No. 516,620 7 Claims. (Q1. 254186) This invention relates to a pneumatically-operated hoist and particularly to such a hoist which enables a load car ried thereby to be more easily manipulated and positioned.

Many types of hoists are known in the art, most of which are driven electrically. Hoists heretofore known generally have had one common disadvantage. When the load must be positioned accurately for a particular use, considerable manipulation of the controls often is required to cause the hoist to move the load to the exact position. Particularly if the momentum of the hoist drive is such as to tend to move the load slightly beyond the intended point when the controls are manipulated, exact positioning is often difiicult and time consuming. It is also diflicult with previous hoists to set a delicate load gently on a surface to avoid damage such as denting, scratching, breaking, etc. Particularly if the momentum of the drive tends to cause the load to move beyond the desired position, the setting of the load on the surface may be excessively hard with damage resulting.

The present invention relates to a pneumatically-operated hoist which is capable of raising and lowering loads with considerable facility and speed and, in addition, can enable the operator to manually move the load to a precise position once it is moved to an approximate position by the hoist. Thus, for example, where a load must be accurately aligned with a stationary object, the load can be brought to the approximate position by means of the hoist controls, after which the load can simply be handled by the operator and moved upwardly or downwardly slightly, as required, to the position in which it is in the proper alignment. Also, when moving a delicate load down to a surface, for example, the load can be brought down to a position near the surface, perhaps an inch or a few inches therefrom, and then the load gently pushed down onto the surface by the operator, with the controls of the hoist then manipulated to lower the hoist hook further to release the hook from the load.

The new hoist has other advantages, including having few moving parts and requiring little maintenance. The hoist is capable of moving loads at high speed and the speed can be easily varied. The hoist also can be tailored to the requirements of any particular application with a minimum amount of adjustments and modifications.

It is, therefore, a principal object of the, invention to provide a hoist capable of moving a load to a position and then enabling an operator to further manipulate the load by hand to a desired position.

Another object of the invention is to provide a pneumatically-operated hoist capable of operating at controlled high speeds.

Still another object of the invention is to provide a pneumatically-operated hoist which can be used for a variety of applications with a minimum amount of adjustments and modifications.

Other objects and advantages of the invention will be apparent from the following detailed description of a preferred embodiment thereof, reference being made to the accompanying drawings, in which: FIG. 1 is a view in perspective of a pneumaticallyoperated hoist embodying the invention, shown supported from an overhead rail, and in turn supporting a specific load by means of a particular supporting hook;

3,325,148 Patented June '13, 1967 FIG. 2 is a somewhat schematic view in longitudinal cross section taken through the hoist and showing a drum and a piston in one position;

FIG. 3 is a view similar to FIG. 2 but showing the drum and piston in elevation and in another position;

FIG. 4 is a view in perspective of a flow control device used with the hoist of FIGS. 1-3;

FIG. 5 is a view in transverse cross section taken along the line 5-5 of FIG. 4;

FIG. 6 is a view in transverse the line 6--6 of FIG. 4;

FIG. 7 is a rear view in elevation of a body of a hand controller for the hoist;

FIG. 8 is a view in a longitudinal cross section taken along the line 88 of FIG. 7 and also showing controller components;

FIG. 9 is a view in cross section similar to FIG. 8 and taken along the line 9-9 of FIG. 7;

FIG. 10 is an enlarged view in section of one valve used with the controller of FIGS. 79; and

FIG. 11 is an enlarged view in section of another valve used with the controller of FIG. 7.

Referring to the drawings, and more particularly to FIG. 1, a pneumatically-operated hoist embodying the invention is indicated at 20 and is supported from an overhead support or beam 22 by a hoist trolley 24. The trolley 24 preferably is of the type discussed in more detail in my co-pending application Ser. No. 389,143, now United States Patent No. 3,261,477. The hoist 20' has a lifting cable 26 extending downwardly therefrom and has a separate control line assembly indicated at 28 terminating in a hand-operated hoist controller 30 located at a convenient height, preferably around waist level or somewhat thereabove, of the hoist operator.

To illustrate the invention more specifically, the cable 26 is shown connected to a particular load hook 32 of generally C-shape configuration. The hook 32 includes an arm 34 and supporting cylinder 36 which extends into a hollow core of a large roll 38 of paper used in printing, for example. The hook is designed so that the cable 26 is approximately over the center of the roll 38 when the supporting cylinder 36 is inserted fully into the core. However, the cylinder 36 does not extend completely through the core but terminates short of the opposite end. In this manner, the roll 38 can be moved onto a suitable spindle of a press or the like when aligned therewith.

With hoists heretofore known, the roll 38 had to be raised or lowered by means of the hoist and the controller 30 until the core of the roll was aligned exactly with the spindle. This often was time consuming and difficult, particularly with the usual hoist in which the momentum of the drive tended to carry the cable slightly beyond the desired position when the drive was shut off. Consequently, the manipulation of the load was slow, even though the hoist was controlled by an experienced operator.

With the new hoist 20, as will be discussed fully subsequently, after the supporting hook 32 is engaged with the roll 38, the roll is picked up by manipulation of the hoist controller 30 and raised or lowered to an approximate position relative to the spindle on which the roll is received. The exact positioning of the roll in alignment with the spindle is then accomplished by the operator who simply pushes upwardly or downwardly slightly on the roll to move it the distance desired until aligned. By Way of example, the roll can be moved within six inches of the spindle and the final manipulation then accomplished by the operator. The extent of manipulation possible in the positioning of the load depends on a number of factors, such as the size of the hoist, the pneumatic pressure involved, and the weight of the load.

cross section taken along If the load is fragile and is to be set on a surface, the controller 31) can be manipulated to move the load within a few inches, for example of the surface. The load is then pushed downwardly onto the surface bythe operator through light pressure on the load, at which time the controller 38 is manipulated to lower the hoist cable further and enable the load hook to be disengaged. Hence, there is little possibility of the operator causing the hoist to be moved too far so that the load sharply contacts the surface and causes damage.

Referring'to FIGS. 2 and 3, the hoist 20 includes a housing 40 having end walls 42 and 44. A ball screw 46 extends longitudinally through the housing 40 and is fastened at each end centrally to the end walls 42 and 44. A ball screw assembly 48 is mounted on the ball screw 46 and moves longitudinally in the housing 48 when turned relative to the ball screw. Ball screw assemblies of this nature are known in the art and will not be discussed in detail. A cable drum 50 is mounted on the ball screw assembly 48 and moves therewith both rotatably and longitudinally relative to the screw 46. The drum 50 has a shallow helical groove 52 which receives the cable 26 when the load is raised and the cable is wound on the drum. One end of the cable is suitable aflixed to the drum at one end of the helical groove.

A thrust bearing 54 is located adjacent the drum t) and bears against a hub portion 56 of the drum. The hearing 54 is mounted on an extension 58 of the drum and is arranged to bear against a piston 60. The piston 68 has a peripheral seal 62 which engages and slides on the inner surface of the housing 40 in gas-tight relationship. In this manner, the second end wall 44, the right hand portion of the housing 40, and the piston 68 form a power or gas chamber to receive gas for operating the hoist. A suitable O-ring seal 64 is held by the piston 60 and is in slidable but sealing contact with a sleeve 66 mounted over the right end of the ball screw 46.

When gas is supplied to the power chamber, air usually being used, and is under sufficient pressure, the piston 60 is moved toward the left and, through the thrust bearing 54, forces the drum 50 and the ball screw assembly 48 in the same direction. During this movement, the ball screw assembly 48 is caused to rotate the drum in a manner to raise the cable 26 and the load. The drum and ball screw assembly in the position of FIG. 2 support the load in the raised position.

Air is supplied to and exhausted from the chamber through an inlet opening 68 in the second end wall 44. The rate of air flow is controlled by a flow control device 70 which, in this instance, is mounted directly on the end wall 44. Air is supplied to the device 70 from a suitable source through a line 72 connected to an inlet passage 74 (FIGS. 4 and 5). The passage 74 communicates with an outlet passage 76 connected to a first flexible control line 78 for the hoist controller 30. Air flow from the line 72 to the line 78 is controlled by a needle valve 80 cooperating with a seat 82 and adjustable by means of a knob 84.

Air from the hoist controller 30 is supplied through a line 86 to an inlet passage 88 and, hence, through an outlet passage 90 to the inlet opening 68 in the second end wall 44-. Flow through these passages 88 and 90 is controlled by a needle valve 92 cooperating with a valve seat 94 and adjustable through a knob 96.

Referring now more particularly to FIGS. 79, the hoist controller 30 includes a main body 100 which receives the lines 78 and 86 and is connected to the housing 40 through a supporting cable 102 (FIG. 1) and a ring 104. A suitable handle 106 extends from the rear of the body 100 and a support 108 extends below the body 100.

A check valve 110 is located in the line 78 to enable flow from the flow control device 70 to the hoist controller 30, but not in the opposite direction. This prevents air in the power chamber from exhausting back through the line 78 in the event of failure of the air supply source.

The body has an inlet passage 112 communicating with the line 78 and with a lower inlet chamber 114. The inlet air flows past a valve 116, when opened, and into a first upper chamber 118. From here, the air flows through a transverse passage to a second lower chamber 122 and to an outlet passage 124. The air then flows through the second flexible line 86 to the How control device 70 and into the hoist power chamber. When the air builds to a suflicient pressure, it raises the load by moving the piston to the left, as shown in FIG. 2, until the valve 116 is again closed to stop the flow. The valve 116 is operated by an L-shaped lever 126 which is pivotally connected to an upper front corner of the body 180 by a pin 128.

If the valve 116 is closed and the load is in a given position, it can then be lowered by opening a second control valve 130 which enables air in the hoist chamber to flow back through the line 86 and the passage 124 and into a second upper chamber 132, from which the air is vented or exhausted through vent ports 134. As the air pressure in the hoist chamber thereby decreases, the load will lower as the piston is urged back toward the right under the force of the load which tends to turn the cable drum 50 and the ball screw assembly 48 in a manner such as to move the piston toward the right. The exhaust valve 130 is operated by another L-shaped lever 136 which also is pivoted at the upper front corner of the body by the pin 128.

The supply and exhaust valves 116 and 130 are preferably especially constructed to obtain particular control characteristics. As shown in FIG. 10, the supply valve 116 includes a valve body 138 forming a chamber 140 having outlet ports 142. A lower opening 144 of the chamber is normally sealed off by a gasket 146 which also seats against a shoulder 148 between the lower and upper chambers 114 and 118 of the control body 100. A valve stem 150 extends through the valve body 138 and below the gasket 146 to a flange 152. A thick valve stem portion 154 immediately above the flange 152 is only slightly smaller than a central opening 156 in the gasket 146. An upper thin portion 158 of the stern 158, however, is of much smaller diameter than the central opening 156.

When the valve stem 150 is pushed downwardly against the force of a return spring by pressure on the L- shaped lever 126, the flange 152 moves away from the gasket 146 enabling a small amount of air to flow between the large portion 154 of the stern 150 and the central opening 156 of the gasket 146. This enables the air to enter the hoist chamber slowly and thereby enables the load to be raised slowly, so that its movement can be closely controlled. If the lever 126 is depressed further, however, so that the thin portion 158 of the stern 150 extends through the central opening 156, the air flow is much greater with the speed at which the load is raised much faster. This enables the load to be raised rapidly, when desired, simply by the operator exerting greater pressure on the lever 126. The air passing through the central opening 156, of course, flows into the chamber 140 of the valve body 138 and out the ports 142 from which it flows to the transverse passage 120.

The exhaust valve .130 includes a valve body 160 forming a chamber 162 with outlet ports 164. A lower central opening 166 of the valve body 160 is closed off by a gasket 168 which seats on a shoulder 170 between the lower and upper chambers 122 and 1'32. A valve stem 172 also has a lower flange 174 but has a thin stern portion 176 immediately thereabove which extends through a central opening 178 in the gasket 168 when thestem 172 is depressed by the lever 136. This enables the air from the power chamber to be exhausted at a substantially fixed rate controlled by the needle valve 92 of the flow control device 70. The stem 172 is urged upwardly by a spring 180 in the same manner as the stem 150.

Regardless of the position of the load, it can be raised or lowered manually by the operator, simply by lifting upwardly slightly or pushing downwardly slightly on the load. While the extent to which the load can be so moved and the pressure required will vary with such factors as the size of the hoist, the pressures used, and the weight of the load, some manual movement is always possible and this is sufiicient in practically all instances to enable the operator to easily manipulate the load from an approximate position to a predetermined position. In a typical example, air pressure can be supplied to the flow control device 70 and to the hoist chamber at a pressure of ninety pounds. The load, and specifically the roll 38 of paper, can weigh sixty pounds. When the load is to be raised and lowered over a total distance of six feet, it can be easily hand manipulated from any approximate position a distance six inches above or below that position to a predetermined position. Further, if the load is delicate and must be placed carefully on a surface, the load can be lowered to a point slightly above the surface by decreasing the pressure in the power chamber by opening the valve 130 through the lever 136. At that point, the load is pushed gently against the surface by the operator and the lever 136 is again depressed to open the valve and further exhaust the hoist chamber so that the supporting hook can be lowered more so as to be disengaged from the load to complete the operation.

Various modifications of the above described embodiment of the invention will be apparent to those skilled in the art and it is to be understood that such modifications can be made without departing from the scope of the invention, if they are within the spirit and the tenor of the accompanying claims.

I claim:

1. A hoist for raising and lowering loads and for enabling a load to be vertically positioned by an operator after the load is moved to an approximate position by the hoist, said hoist comprising a housing forming a gas chamber and an inlet communicating with the chamber, a piston in said housing forming an end of said chamber, a cable drum in said housing movable longitudinally of said housing with said piston, means in said housing rotatably supporting said drum and causing said drum to rotate when moved longitudinally; a flow control device comprising a body having an inlet passage for a supply of gas, an outlet passage, a gas passage communicating with said gas inlet of said housing, a needle valve associated with said inlet passage to control the supply of gas therefrom, a second needle valve associated with said gas passage to control the flow of gas therethrough, a first flexible gas line communicating with said outlet passage, a second flexible gas line communicating with said gas passage; a hand controller including a main body, a handle attached to said main body, said man body having an inlet connection to receive said first gas line, a second connection to receive said second gas line, a transverse passage connecting said first and said second connections, a first valve arranged to control the flow through said transverse passage, a lever pivotally connected to said body for operating said first valve by hand, a vent in said main body communicating with said second gas line downstream of said first valve, a second valve in said body to control the flow of gas from said second line to said vent, a second lever connected to said body for operating said second valve, and a check valve in said first gas line to prevent flow therethrou-gh from said main body to said flow control device.

2. A hoist for raising and lowering loads and for en abling a load to be manipulated directly by an operator after the load is moved to an approximate position by the hoist, said hoist comprising a housing forming a gas chamber and an inlet communicating with the chamber, a piston in said housing forming an end of said chamber, a cable drum in said housing movable longitudinally of said housing with said piston, means in said housing rotatably supporting said drum and causing said drum to rotate when moved longitudinally, a source of gas, a flow control device for regulating rate of flow of gas to said chamber from said source, a hand controller including a body, said body having an inlet connection, and a second connection, a first flexible gas line communicating with said inlet connection and said flow control device to supply gas from said device to said hand controller, a second flexible gas line communicating with said second connection and said flow control device to supply gas from said controller to said device, said controller having a first valve in said body arranged to control flow of gas from said first line to said second line, a vent in said body disposed to communicate with said second gas line, and a second valve in said body arranged to control flow of gas back from said second line to said vent.

3. A hoist according to claim 2 wherein said flow control device comprises a body having an inlet passage connected with the source of gas, an outlet passage connected with said first flexible gas line, valve means associated with said inlet passage and said outlet passage for regulating the flow of gas therethrough, a second inlet passage connected with said second flexible gas line, a second outlet passage communicating with said housing inlet, and second valve means associated with said second inlet passage and said second outlet passage for controlling the flow of gas therethrough.

4. A hoist according to claim 2 wherein said hand controller is further characterized by a transverse passage connected between said inlet connection and said second connection downstream of said first valve and independent of said second valve.

5. A hoist according to claim 4 characterized by said second valve in said controller being a poppet valve including means forming an opening of predetermined diameter between said second flexible gas line and said vent, and a stem having an end flange adapted to close said opening when said stem is in one position, said stem having a thin portion substantially smaller than said opening adapted to be disposed in said opening when said valve stem is in a second position to enable a substantially unrestricted flow of gas therethrough.

6. A hoist according to claim-4 wherein said first valve includes means forming an opening between said first flexible gas line and said transverse passage, and a stem extending through said opening and having an end flange adapted to close said opening when said stem is in one position, said stem having a thick portion slightly smaller than said opening above said flange and a thin portion substantially smaller in diameter than said opening beyond said thick portion, whereby said stem enables relatively small flow of gas through said opening when in a second position with the thick portion in said opening and enables greater flow of gas through said opening when in a third position with said thin portion in said opening.

7. A hoist for raising and lowering loads and for enabling a load to be manipulated directly by an operator after the load is moved to an approximate position by the hoist, said hoist comprising a housing forming a gas chamber and an inlet communicating with said chamber, a piston in said housing forming an end of said chamber a cable drum in said housing movable longitudinally of said housing with said piston, means in said housing rotatably supporting said drum and causing said drum to rotate when moved longitudinally, a source of gas, a flow control device for regulating rate of flow of gas to said chamber from said source, a hand controller including a body, said body having an inlet connection, and a second connection, a first flexible gas line communicating with said inlet connection to supply gas from said source to said hand controller, a second flexible gas line communicating with said second connection and said flow control device to supply gas from said controller to said device, said controller having a first valve in said body arranged to control flow of gas from said first line to said. second line, a vent disposed to communicate with said second gas line, and a 7 second valve in said'body arranged to control flow of gas 2,500,879 back from said second line to said vent. 2,710,107 2,831,554 References Clted 2,932,316 UNITED STATES PATENTS 5 1,606,426 11/1926 Justen 137-5962 2,129,511 9/1938 Thompkins et a1 25112 1 2,478,494 8/ 1949 Martin 254-150 %3 Smallpiece. Powell. Reynolds 254186 Stanton 251-121 EVON C. BLUNK, Primary Examiner.

H. C. HORNSBY, Assistant Examiner.

Claims (1)

1. 2. A HOIST FOR RAISING AND LOWERING LOADS AND FOR ENABLING A LOAD TO BE MANIPULATED DIRECTLY BY AN OPERATOR AFTER THE LOAD IS MOVED TO AN APPROXIMATE POSITION BY THE HOIST, SAID HOIST COMPRISING A HOUSING FORMING A GAS CHAMBER AND AN INLET COMMUNICATING WITH THE CHAMBER, A PISTON IN SAID HOUSING FORMING AN END OF SAID CHAMBER, A CABLE DRUM IN SAID HOUSING MOVABLE LONGITUDINALLY OF SAID HOUSING WITH SAID PISTON, MEANS IN SAID HOUSING ROTATABLY SUPPORTING SAID DRUM AND CAUSING SAID DRUM TO ROTATE WHEN MOVED LONGITUDINALLY, A SOURCE OF GAS, A FLOW CONTROL DEVICE FOR REGULATING RATE OF FLOW OF GAS TO SAID CHAMBER FROM SAID SOURCE, A HAND CONTROLLER INCLUDING A BODY, SAID BODY HAVING AN INLET CONNECTION, AND A SECOND CONNECTION, A FIRST FLEXIBLE GAS LINE COMMUNICATING WITH SAID INLET CONNECTION AND SAID FLOW CONTROL DEVICE TO SUPPLY GAS FROM SAID DEVICE TO SAID HAND CONTROLLER, A SECOND FLEXIBLE GAS LINE COMMUNICATING WITH SAID SECOND CONNECTION AND SAID FLOW CONTROL DEVICE TO SUPPLY GAS FROM SAID CONTROLLER TO SAID DEVICE, SAID CONTROLLER HAVING A FIRST VALVE IN SAID BODY ARRANGED TO CONTROL FLOW OF GAS FROM SAID FIRST LINE TO SAID

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