US3083948A

US3083948A - Electro-lift

Info

Publication number: US3083948A
Application number: US166344A
Authority: US
Inventors: Goldfader Sol
Original assignee: Individual
Current assignee: Individual
Priority date: 1962-01-15
Filing date: 1962-01-15
Publication date: 1963-04-02
Anticipated expiration: 1980-04-02

Description

April 2, 1963 s. GOLDFADER 3,083,948

ELECTRO-LIFT 2 Sheets-Sheet 1 Filed Jan. 15, 1962 IN VEN TOR.

50/ Goldfader April 2, 1963 s. GOLDFADER ELECTRO-LIFT 2 Sheets-Sheet 2 Filed Jan. 15. 1962 INVENTOR.

Sol Goldfader United States Patent 3,083,948 ELECTRO-LIFT Sol Goldfader, 8116 Halifax Drive, Clayton, Mo. Filed Jan. 15, 1962, Ser. No. 166,344 2 Claims. (01.254 1 This invention relates generally to lifting devices, and more specifically to an electrically operated portable hoist of novel construction.

It is a primary object of this invention to provide a portable hoist which may be raised and lowered in response -to an electrically operated thread drive which enables precise control of the hoist in both directions.

It is a further object of this invention to provide a screw operated portable hoist which is combined with limit switches for preventing extension or retraction beyond safe limits.

It is a still further object of this invention to provide a portable hoist of the above class which can be used by electrical contractors for hoisting and holding fluorescent fixtures and similar electrical equipment for mounting in the ceiling. It is also adaptable for use in positioning plasterboard sheets, air conditioning ducts, pipes, sprinkler systems, and all types of elevated structure which is to be supported from the ceiling of the building.

A full understanding of the details of the invention, together with further advantages, will become apparent by reference to the following detailed description of a preferred embodiment thereof, taken in conjunction with the attached drawings wherein:

FIG. 1 is a perspective View of the portable hoist in the collapsed condition.

FIG. 2 is a cross sectional side elevation taken along the line 2-2 of FIG. 1.

FIG. 3 is a fragmentary side elevation taken along the line 33 of FIG. 2.

FIG. 4 is a cross sectional plan view taken along the line 4-4 of FIG. 3.

FIG. 5 is a cross sectional plan view taken along the line 5-5 of FIG. 2.

FIG. 6 is a fragmentary underside view and taken at 66 in FIG. 2.

FIG. 7 is a schematic wiring diagram of the electrical circuit used in operating the hoist.

Similar reference characters indicate corresponding parts throughout the several views in the drawings.

Referring now to the drawings in detail, the numeral 10 represents a dome shaped pedestal which is circular in shape and is supported about its periphery by four castor wheels 11. A tubular standard 12 projects upwardly from the centre of the pedestal and is sealed thereto so as to communicate inwardly of the pedestal. A fixed bronze bearing 13 is'mounted in the lowermost end of the standard and receives the lower end 14 of a threaded shaft 15 therethrough. The shaft 15 is threaded along its length as indicated at 16, the said threads terminating at 17 at which point a bushing .18 is firmly secured about the shaft. An intermediate bushing 19 is disposed between the bearing 13 and bushing 18 so as to provide a thrust bearing on which the threaded shaft may rotate on a vertical axis. The lower end 14 of the shaft extends through the bearing and terminates within the pedestal with a large belt pulley 20. An electric motor 21 is mounted on a platform 22 formed on the outer side of the pedestal such that the motor shaft 23 projects beneath the pedestal and terminates with a drive pulley 24 disposed in a horizontal plane with the pulley 29 for cooperation therewith by means of a belt 25.

A threaded boss 26 is slideably received within the standard 12 and engages on the threaded shaft 15 for axial movement therealong in response to rotation of Patented Apr. 2, 1963 the shaft by the motor 2 3. The standard is provided with a slot 27 which extends axially thereof along the greater part of its length for the purpose of receiving a stop lug 28 therethrough, the stop lug being mounted radially into'the side of the threaded boss 26. The stop lug prevents rotation of the boss so as to restrict movement of the same longitudinally within the tubular standard. A tubular extension sleeve 29 is slideably received within the standard 12. and is secured at its lower end to a protruding portion 30 of the boss. The extension sleeve will .thus move longitudinally with respect to the standard in response to movement of the boss 26.

A telescopic tubular extension 31 protrudes from the upper end of the extension sleeve 29 and is provided with a slot 32 extending longitudinally of the extension and terminating inwardly ofthe ends thereof. The tubular extension extends and retracts within the sleeve 29 simultaneously with the said extension sleeve. This is accomplished by mounting a small pulley 33 on the coupling 34 which forms the uppermost end of the extension sleeve 29. A strap or wire 35 extends over the pulley and inwardly through the slot 32 terminating within the extension at its lowermost end 36. The other end of the wire 35 extends downwardly on the outer side of the extension 31 and is secured to the coupling 37 which forms the uppermost end of the tubular standard 12. It will thus be seen that the extension of the sleeve 29 outwardly of the standard will simultaneously cause the tubular extension 31 to extend outwardly of the extension sleeve 29.

The upper end of the telescopic extension 31 terminates with a small platform 38 having upstanding sides 39 for the purpose of mounting specialized adaptors such as 40 shaped to suit the purpose for which the hoist is being used.

The upward extension of the tubular sleeve 29 is limited by a limit switch 41 which is secured to the upper end of the standard with a downwardly protruding sensing button 42 positioned for engagement by a stop arm 43 secured to the protruding stop lug 28.

The stop arm 43 extends downwardly below the stop lug 23 with an arm 44 which terminates with a normally protruding roller 45. The roller is adapted to engage with a limit switch 46 which is housed in a casing 47 mounted on the pedestal 10. The design of the limit switch is a matter of choice .and both switches may be identical and constructed in a conventional manner.

The hoist may be stabilized when necessary by three telescopic legs 4-8 which are bifurcated at 49 at their upper ends for pivotal attachment to the tubular standard intermediate the length thereof. The legs 48 have telescopic extension arms 50 which may be locked at a desired extension by means of wing nuts 51 disposed at the lower end of the legs. Outward pivotal movement of the legs is restricted by a safety chain 52 which extends around the legs as indicated in FIG. 1, of the drawing. The legs may be folded and collapsed adjacent the tubular standard or may be extended in a form of a tripod to stabilize the standard when necessary.

A control switch 53 is provided with spring operated forward and reverse buttons 54 and 55 for controlling the motor when raising or lowering the hoist. It is intended that the switch may be located remotely from the lift if so desired, so as to enable operation from a ladder or other relatively remote position.

it will be appreciated that some modifications may be made to the precise configuration, Without departing from the scope or spirit of the invention, as defined by the following claims.

I claim:

1. A portable electrically operated hoist comprising, a pedestal, castor wheels mounted on the underside of the pedestal for engagement with the ground, an electric motor mounted on the pedestal and having a shaft extending vertically therethrough, a tubular standard secured to project vertically from the centre of the pedestal, a threaded shaft mounted concentrically within the standard and protruding through the pedestal, drive means connecting the motor shaft and the protruding portion of the threaded shaft, a threaded boss slideably mounted within the standard and engaging over the threaded shaft, means preventing rotation of the boss within the standard, a tubular extension sleeve slideably mounted within the standard and terminating at its lower end in engagement with the boss for movement therewith, a telescopic 20 tubular extension slideably mounted in the extension sleeve, an adaptor removably mounted to the upper end of the telescopic extension, and limit means controlling the degree of extension and retraction of the extension sleeve with respect to the standard, a slot formed longitudinally of the standard, a stop lug secured to the boss and protruding through the slot to prevent rotation of the boss, said lug cooperating with the limit means to arrest movement of the extension sleeve relative to the standard.

2. A portable electrically operated hoist according to claim 1, wherein three telescopic legs are pivotally mounted to the side of the standard for selective extension in the form of a tripod to engage with the ground and provide increased rigidity for the hoist.

References Cited in the file of this patent UNITED STATESPATENTS 1,694,243 Wilford Dec. 4, 1928 1,708,761 Horhath Apr. 9, 1929 2,792,913 Capgras May 21, 1957 2,969,220 Spencer Jan. 24, 1961

Claims

1. A PORTABLE ELECTRICALLY OPERATED HOIST COMPRISING, A PEDESTAL, CASTOR WHEELS MOUNTED ON THE UNDERSIDE OF THE PEDESTAL FOR ENGAGEMENT WITH THE GROUND, AN ELECTRIC MOTOR MOUNTED ON THE PEDESTAL AND HAVING A SHAFT EXTENDING VERTICALLY THERETHROUGH, A TUBULAR STANDARD SECURED TO PROJECT VERTICALLY FROM THE CENTRE OF THE PEDESTAL, A THREADED SHAFT MOUNTED CONCENTRICALLY WITHIN THE STANDARD AND PROTRUDING THROUGH THE PEDESTAL, DRIVE MEANS CONNECTING THE MOTOR SHAFT AND THE PROTRUDING PORTION OF THE THREADED SHAFT, A THREADED BOSS SLIDEABLY MOUNTED WITHIN THE STANDARD AND ENGAGING OVER THE THREADED SHAFT, MEANS PREVENTING ROTATION OF THE BOSS WITHIN THE STANDARD, A TUBULAR EXTENSION SLEEVE SLIDABLY MOUNTED WITHIN THE STANDARD AND TERMINATING AT ITS LOWER END IN ENGAGEMENT WITH THE BOSS FOR MOVEMENT THEREWITH, A TELESCOPIC TUBULAR EXTENSION SLIDEABLY MOUNTED IN THE EXTENSION SLEEVE, AN ADAPTOR REMOVABLY MOUNTED TO THE UPPER END OF THE TELESCOPIC EXTENSION, AND LIMIT MEANS CONTROLLING THE DEGREE OF EXTENSION AND RETRACTION OF THE EXTENSION SLEEVE WITH RESPECT TO THE STANDARD, A SLOT FORMED LONGITUDINALLY OF THE STANDARD, A STOP LUG SECURED TO THE BOSS AND PROTRUDING THROUGH THE SLOT TO PREVENT ROTATION OF THE BOSS, SAID LUG COOPERATING WITH THE LIMIT MEANS TO ARREST MOVEMENT OF THE EXTENSION SLEEVE RELATIVE TO THE STANDARD.