US3310290A

US3310290A - Braking means for a rotary hoist

Info

Publication number: US3310290A
Application number: US454501A
Authority: US
Inventors: Lawrence H Workman
Original assignee: Gardner Denver Inc
Current assignee: Gardner Denver Inc
Priority date: 1965-05-10
Filing date: 1965-05-10
Publication date: 1967-03-21
Anticipated expiration: 1984-03-21
Also published as: SE327520B; DE1431990A1; GB1123443A; BE679894A

Description

March 21, 1967 H. WO RKMAN 3,310,290

BRAKING MEANS FOR A ROTARY IiIOIST Filed May 10, 1965 INVENTOR. LAWRENCE H. WORK/WAN W ZZ/ A T TOR/V5 Y United States Patent 3,310,290 BRAKING MEANS FGR A ROTARY HOET Lawrence H. Workman, Muskegon, Mich. assignor to Gardner-Denver Company. a corporation of Delaware Filed May 10, 1965, Ser. No. 454,561 2 Claims. (Cl. 254-168) This invention generally concerns hoists and, more particularly, an improved structural and functional relationship of a rotary hoist motor and a load braking device.

An object of the invention is the provision of a hoist body having a hollow casing member providing a common housing for a rotary drive motor and a load brake wherein the motor and the brake are advantageously disposed in closely spaced, coaxial relation to one another.

Another object is to provide a hoist motor and adjustable load brake in a common housing member whereby the motor and other operating elements of the hoist may be easily assembled and disassembled with respect to the brake without disturbing a preset adjustment of the braking force provided by the brake.

Another aspect of the invention is the provision of a drum-type brake for a rotary hoist which is supported and journaled by a hoist casing member so that braking forces which are radially applied to the brake drum are borne by the casing member rather than by the motor bearings or other operating parts of the hoist.

Yet another object is the provision of a hoist which is characterized by light weight and compactness, by economical manufacture and maintenance, and by simplicity and reliability in operation.

These and other objects and advantages will appear upon reading the following description and appended claims and upon considering in conjunction therewith the accompanying drawings, in which:

FIG. 1 is a perspective view of a hoist embodying the present invention;

FIG. 2 is a section taken generally along lines 2-2 of FIG. 3; and

FIG. 3 is an enlarged fragmentary section taken generally along lines 3-3 of FIG. 2.

FIG. 1 illustratues a hoist having a body, indicated in its entirety by numeral 10, including a gear housing 12, a motor housing 14 and a closure member 16. Integrally formed on the exterior of the gear hOusing 12 are two projecting

bosses

18 and 20 which respectively provide a fair-lead for a hoist cable 22 and a mount for a load hook 24. The load hook 24 and the cable 22 are vertically aligned and are laterally offset from the vertical center line of the hoist body 10. The upper end of the cable 22 is connected to a support book 26 by means of a swivel plate 28; and, the support book 26 is adapted to engage with any suitable overhead member, not shown. As best shOWn in FIG. 3, the gear housing 12 is substantially bellshaped and houses in its interior rotative drive elements of the hoist. A lipped flange 30 of the gear housing 12 matingly receives a radially projecting flange 32 of the motor housing 14 and is attached thereto for ready removal by the threaded fasteners 34. A cylindrical cavity 36 extends nearly the full length of the motor housing 14 and is substantially closed at its inner end by a transverse Wall 38 having a central aperture 40 opening therethrough. The aforementioned closure member 16 is removably secured to one end of the motor housing 14 by suitable fasteners 42 for closing the outer end of the cavity 36. Integrally formed with the closure member 16 are arm 44 and a horizontally disposed handle 46, the latter being laterally spaced from the hoist body 10 and intersecting the arm 44 at approximately right angles to form an elbow. By removing the fasteners 42, the closure member 16 may be rotated 180 to facilitate grasping of the handle 46 by a left-handed operator.

Referring to FIG. 3, an expansible chamber pressure fluid motor of the conventional rotary vane type is generally designated by numeral 48 and is removably mounted in cavity 36 of the motor housing member 14. The motor 48 comprises a cylinder 50

mounting end plates

52 and 54, the latter end plate carrying an antifriction bearing 56 which rotatively journals a hollow driving sleeve extension 58 of the motor rotor 60. The construction and operation of this type of pressure fluid motor is well known and need not be described herein in detail. For the purpose of supplying motive fluid to the motor 4-8, a flexible conduit 62 which encircles the cable 22 is coupled to the handle 46 by a suitable fitting 64 and is anchored at its upper end to the swivel plate 28. Pressure fluid is supplied from a source, not shown, to a fitting 66 at the upper end of the conduit 62.

Valve actuating levers

68 and 70 are pivotally mounted near the juncture of the arm 44 and the handle 46 and are alternately depressible for actuating a pair of fluid supply valves, not shown, disposed within the handle 46. These supply valves are operable in a conventional manner to communicate motive fluid from conduit 62 to inlet ports of the motor 48 through suitable fluid passages, not shown, in the closure member 16. Other passages, not shown, in the motor casing 14 and the closure member 16 return motor exhaust to a bore 72 through the handle 46 for venting the exhaust to atmosphere. By digitally manipulating the valve actuating levers 68 and 70, the hoist operator can effect reversible rotation of the motor 48 and, as will be understood from the following description, the hoist motor can be controlled in this manner for vertically raising and lowering the hoist body 10 and a load attached to the hook 24.

The rotary power output of the motor 48 is imparted to a pinion shaft 74 which has a splined end '76 held in relatively reciprocable, but nonrotatable relationshi with mating splines on the interior wall of the sleeve extension 58 of the rotor 66. The pinion shaft 74 extends coaxially from the motor 48 into the gear housing 12 into rotary driving engagement with the input elements of a conventional speed reducing gear train, not shown, the output element of which rotatively drives a cable reel 77 comprising joined plates 78 and 80. As shown in FIG. 3, the load bearing cable 22 is wound about the reel 77 within an annular groove defined between the plates 78 and 80. Plate 78 is journaled by a bearing 82 carried by the gear housing 12; and, plate is journaled by a bearing 84 carried by the transverse wall 38.

A load brake assembly for the hoist includes a rotary brake drum 86, a brake shoe 88, a brake spring and a brake releasing piston 92. The brake drum 86 is located within the cavity 36 generally between the motor end plate 54 and the transverse wall 38 and in coaxial relation with the motor 48 and the pinion shaft 74. The brake drum 86 has an internally splined center opening and an extension or boss 94 which is supported and rotatively journaled in the aperture 40 of wall 38 by means of a bearing 96. The drum 86 coaxially surrounds the splined end 76 of the pinion shaft 74 in relatively reciprocable, but nonrotatable relationship. As viewed in FIG. 2, the brake shoe 8% is in the shape of a reversed C and is pivotally attached at one end to the transverse wall 38 by a pin 98 which penetrates a bent over En of the shoe. The other end of the shoe 88 carries a spring guide pin 100 which engages with one end of the brake spring 90 extending into the cavity 38 in line with the shoe 88. The curved central portion of the shoe 88 is provided with a replaceable brake liner 102 for frictionally engaging the circumferential Wall of the drum 86 when the spring 90 forcibly biases the shoe 88 against the rim of the drum. An adjusting screw 104 bears against the spring 90 and may be turned within the threaded opening 106 in the motor housing 14 to move the spring relative to the shoe 86 thereby to preset the compressive force with which the spring 90 biases the shoe 88 and liner 102 against the drum 86. From the foregoing it will be understood. that the brake is spring applied and may be adjusted to regulate the frictional braking force applied to the rotary drum 86. A preferred means for releasing the brake comprises a pressure fluid actuated piston 92 which is shiftable within a cylinder 103 defined by the motor housing 16. It is contemplated that, upon energization of the motor 48 for driving in either direction, pressure fluid, will be directed through suitable passages, not shown, in the motor housing to the cylinder 108 for shifting the piston 92 in a direction to cause a piston stem 110 to compress spring 90 and to pivot the brake shoe 88 and the liner 102 out of braking engagement with the shoe 86.

The preferred mode of operation of the illustrative hoist is as follows: Assuming that it is desired to lower the hoist body 10 to position the hook 24 for loading,

the operator grasps the handle 46 with his hand so that his thumb overlies the valve actuator 70. Upon depression of actuator 70, motive fluid is admitted to the motor 48 for driving the pinion shaft 74, the associated reduction gearing, and the reel 77 in a direction whereby the cable 22 will pay out and the hoist body 10 will travel downwardly. Simultaneously with actuation of the motor 48, it is contemplated that pressure fluid will be supplied to cylinder 102 to force the piston stem 110 against the brake shoe 88 thereby compressing the spring 90 and releasing the brake drum 86 for rotation with the pinion shaft 74 to which it is splined. When the body 10 has been lowered to the desired loading position, the actuator 70 is released thereby deenergizing the motor 48 and interrupting the fluid supply to the cylinder 108 so that the braking force of the brake spring 90 will be applied radially to the drum 86 by means of the shoe 88 and the liner 102. The drum 86 will transmit such braking force to the motor 48 and the reel 77 through the shaft 74. To raise the loaded hoist body, the valve actuator 68 is depressed thereby energizing the motor 48 for reverse rotation and releasing the brake assembly to permit the reel 77 to rotate for taking up the cable 22.

Prior to operating the hoist, the adjusting screw 104 should be preset Within the opening 106 to effect compression of the spring 90 sufficiently to assure that the braking force applied to the drum 86 is sufiicient to prevent retograde movement of the motor 48, the pinion shaft 74, the reduction gearing, and the reel 77 under conditions of maximum anticipated loading of the hook An advantageous feature of this invention is realized by the provision of a brake drum 86 which is independently supported and journaled by a main structural element of the hoist body, i.e. by the transverse wall 38 of the motor housing 16. This is in contradistinction to conventional practice wherein the brake drum is journaled on and supported by the motor drive shaft or by a drive coupling member such as the pinion shaft 74. By inde pendently journalling and supporting the brake drum 86 in the manner disclosed herein, the radially applied braking loads imparted to the drum by the spring 90 through shoe 88 are substantially isolated from the rotor bearings 56 and the pinion shaft 74. By this means, loading and resultant wear of the rotor bearings 56 due to braking forces are substantially reduced or completely eliminated; .and, bending stresses in the pinion shaft 74 tending to produce deleterious misalignment of the same are likewise reduced or eliminated.

Another distinguishing feature of this invention is the provision of a motor housing member having a cavity which conveniently receives both the hoist motor and the brake assembly. As will be observed in FIG. 3, the motor 48 and the brake parts 86 and 88 are both disposed in a (common cavity 36 and in closely spaced coaxial relation to one another. This arrangement of the motor and the brake is particularly advantageous where minimizing the over-all length of the hoist body is an important design consideration. Moreover, in accordance with the disclosed arrangement of the motor and brake, the brake can be located so that the braking force produced thereby is applied to the motor pinion shaft 74 at a point intermediate the ends thereof, i.e. between the driving motor 48 and the driven reduction gearing, thereby greatly reducing normally expected inertia and reactance forces tending to produce potentially damaging torsional stress and deflection in the pinion shaft.

From the foregoing it will be seen that the disclosed hoist brake assembly having a brake drum 86 journaled independently on a casing member 14 of the hoist body 10 need not be disassembled from the hoist in order to disassemble either or both the motor 48 and the pinion shaft 74 from the hoist. To replace or repair the motor 48, it is only necessary to remove the closure member 16 and to withdraw the motor 48 axially from cavity 36 thereby disengaging the splined driving connection between the rotor sleeve extension 58 and the splined end 76 of the pinion shaft 74. To disassemble the pinion shaft 74 from the brake drum 86 in order to replace or repair any of the hoist parts housed in the gear housing 12, the gear housing is merely detached from the flange 32 of the motor housing 14 and withdrawn axially thereby disengaging the splined connection between the brake drum 86 and the splined end 76 of the pinion shaft 74. Thus it Will be understood that either or both the motor 48 and the pinion shaft 74 can-be disassembled from the brake assembly without disassembly of any of the parts of the brake assembly. This novel coaction of the brake assembly with the hoist motor 48 and with the motor pinion shaft '74 not only makes it easier to disassemble and reassemble the hoist parts, but also provides this advantage without disturbing a preset adjustment of the brake spring 90. Since the preadjusted setting of the brake spring need not be changed, repair of the hoist is made quicker and easier and all hazards due to improper readjustment of the brake are avoided.

The exemplary hoist is adapted for actuation by pressure fluid, such as compressed air; however, it is not intended that the invention be limited thereto. For example, an electric motor having suitable controls for effecting reverse rotation and associated solenoid means for releasing the brake shoe 88 could be substituted for the disclosed motor 48 and the brake releasing piston 92, respectively. Furthermore, the cable 22 could be replaced by any equivalent flexible tension member such as a chain. Moreover, it will be understood that the above description and accompanying drawings comprehend only a general and preferred embodiment of the invention and that various changes in construction, proportion, and arrangement of the elements thereof may be made with out sacrificing any of the above enumerated advantages or departing from the scope of the appended claims.

What is claimed as new and useful is:

1. A rotary hoist comprising:

housing means having a cavity therein;

a rotary motor disposed in said cavity;

reel means for a flexible load bearing member;

drive means connecting said motor to said reel means:

brake means for said motor and said reel means;

said brake means being disposed in said cavity; said brake means having a rotary element in brake force transmitting relation with said drive means; and

said rotary element being supported and journaled by said housing means, said housing means includes a transverse wall defining the closed end of said cavity; said wall being provided with an aperture; said rotary element being disposed between said motor and said wall, and said rotary element being supported and jou-rnaled in said aperture.

5 6 2. The invention according to claim 1, wherein: 2,831,554 4/1958 Reynolds 254-186 said drive means includes a shaft which penetrates said 3,184,018 5/1965 Christison 254186 aperture and extends into said cavity; and said motor and said shaft are held in relatively recip- FOREIGN PATENTS rocable, but nonrotatable relationship. 5 0,099 4/1956 France.

References Cited by the Examiner EVON BLUNK, Primary Examiner- UNITED STATES PATENTS H. C. HORNSBY, Assistant Examiner.

2,496,754 2/1950 Schramm 254168

Claims

1. A ROTARY HOIST COMPRISING: HOUSING MEANS HAVING A CAVITY THEREIN; A ROTARY MOTOR DISPOSED IN SAID CAVITY; REEL MEANS FOR A FLEXIBLE LOAD BEARING MEMBER; DRIVE MEANS CONNECTING SAID MOTOR TO SAID REEL MEANS; BRAKE MEANS FOR SAID MOTOR AND SAID REEL MEANS; SAID BRAKE MEANS BEING DISPOSED IN SAID CAVITY; SAID BRAKE MEANS HAVING A ROTARY ELEMENT IN BRAKE FORCE TRANSMITTING RELATION WITH SAID DRIVE MEANS; AND SAID ROTARY ELEMENT BEING SUPPORTED AND JOURNALED BY SAID HOUSING MEANS, SAID HOUSING MEANS INCLUDES A TRANSVERSE WALL DEFINING THE CLOSED END OF SAID CAVITY; SAID WALL BEING PROVIDED WITH AN APERTURE; SAID ROTARY ELEMENT BEING DISPOSED BETWEEN SAID MOTOR AND SAID WALL, AND SAID ROTARY ELEMENT BEING SUPPORTED AND JOURNALED IN SAID APERTURE.