US1690107A - Elevating apparatus - Google Patents

Description

Nov. 6, 1928.

H. S. GERMOND, JR

ELEVATING APPARATUS Filed Oct. 6, 1927 [/4 mvsmoa .BY 'f ATTORNEYE.

Patented Nov. 6, 1928.

UNITED STATES HENRY s. GERMOND, an, or BAYONNE, NEW JERSEY.

, ELEVATING ArrARA'rUs.

Application file d bombers, 1927. semi No. 224,378.

This invention relates in general to elevating apparatus and particularlyto portable elevators or so-oalledtiering machines'which comprise a portable vertical frame upon which is vertically movable by hoisting apparatus a load carrying platform. The hoisting apparatus now is usually driven'by electric motors, and either mechanical or solenoid brakes are commonly utilized for holding the platform in elevated position. Also means is usually provided forsimultaneously automatically shutting off the power, such as elec tric current, from the hoisting apparatusand automatically applying the brake when the platform reaches itsupperlimit and its lower limit of movement, such means comprising a control chain or cable running freely over pulleys at the top and ,thebottom of the eleva tor frame and having stopblocks engaged by a projecting stop arm on the platform, and

means connectingthe cable to the power control means and the brake so that movement of the cable caused by contact of said stop arm with either stop block shuts offthe power and applies the brake. VVit'h such construct-ions now known considerable difiiculty is expe rienced by presence of slack in the cable or chain and lost motion thereof over the pulleys,

which makes the operation of the power con trol means and the brakemechanism slow and unreliable, and the slack chain or eable is an obstruction or hindrance to other moving parts. ,p i

One object ofmy invention is to provide elevating apparatus ofthis general character including novel and improved means for maintaining the cable or chain taut to eliminate lost motion, andto provide a positive and quick acting connection of the cable or chain to the power control means. Another object is toprovide a novel and im proved construction whereby both the brake and the powercontrol means, such as an electric switch, are operated instantly, positively, and simultaneously upon movement of the control cable.

A further object is to provide in such apparatus a novel and improved combination of i means for maintainingthecontrol cabletaut and eliminating slack and relative sliding of the cable and the pulleys, andmeans for operating the brake and the power control means,-

whereby power to operate the-brake the power control means is applied to the brake and the power control means from'the same point both in manualoperation and through and quick operation of both the brake and the power control means is ensured at all times whether-the controlling movement is applied to the control cable-by an operator on the platform or on the floor, or is automatically appliedby'the platform.

Other objects are to provide apparatus of this character wherein the control cable is wound arounda drum on the brake shaft which is connected by crank arms and a link to the shaft of the power controllingmeans, and the brake shaft has an operating handle for manual control, whereby said drum serves both to maintain the control cable taut and to operatlvely connect the cable to the brake shaft; to provide such a construction includ ing a. minimum number of simple and inexpensive parts, and-to obtain other advantages and results asmay be brought out by the following description. v

Referring to the accompanying drawings in which corresponding; and like partsare designated throughout the several views by the same reference characters,

Figure 1 is a side elevation of a portable elevator embodying my invention, certain details of construction of elevators-not essential to an understanding of the invention being omitted;

Figure 2 is a front-elevation ofthe elevator,

Figure 3 is an enlarged fragmentary end view of the brake mechanism.

Specifically describing the illustrated embodiment of the invention, the elevatoris of the general type-described in United States Patent No. 1,197 ,597, dated September 12,

1916, andcomprises a vertical frame A formed of two uprightandspaced channel bars which have their channels facing each other. A load carryingplatform Bis mounted on rollers C within the channels of the. bars 1 to move up and down on the frame A. Any suitable mechanismmay-be utilized for raising and lowering the platform, but in the present instancel have shown this mechanism as comprising-a cable 2 to pass over a sheave 3 mounted at the upper end ofthe frame, the cable being attached to a drumt mounted on a supplementary frame 5. The drum is driventhrough a gear 6 meshed with .a pin ion? on-a countershaft 8 upon which is-ialso mounteda gear 9 which mesheswith another pinion '10 ona second countershaft'll. The

sprocket 12 connected by a chain 13 to a sprocket 14: on the shaft of a reversible motor 15. \Vith this construction, obviously rotation of the motor in opposite directions will cause respective raising and lowering of the platform B.

The motor 15 is controlled by an electric switch 16 of known construction which includes a shaft 17 having a crank arm 18 there on. The switch is in neutral or open position when the crank arm is substantially horizontal, and is closed to start the motor in one direction when the arm 18 is swung upwardly and closed to start the motor in the other direction when said arm is swung downwardly.

Brake mechanism D is provided for holding the platform 13 in any position on the frame A. The brake mechanism is identical with that disclosed in said Patent No. 1,197,597 and includes brake drum 19 rotatable on the eountershaft 11, the drum having an interior ratchet 20 with which cooperates a spring pawl 21 carried by a cross head 22 fixed upon the shaft 11. A pair of brake shoes 23 surround the brake drum and are connected at one end by a tiebolt 2t. The ends of the shoes are bifurcated and embrace an ope 'ating shaft 25, a compression spring 26 being ar 'anged on said shaft to normally force said brake shoes out of engagement with the drum. For forcing the brake shoes into engagement with the drum a pair of earns 27 are keyed on the shaft and cooperate with the follower rollers 28 on the respeetive brake shoes. \Vith this construction when the shaft 25 is rotated in one direction the cams 27 are rotated so as to permit the b ake shoes to be disengaged from the drum by the spring 26, while when the shaft 25 is rotated in the other direction the brake shoes are forced by the cams 2T tightly into engagement with the drum to prevent rotation thereof. It will be observed that the operatin; shaft 25 in connection with the brake drum permits free rotation of the shaft 11 to elevate the platform, but backward rotation of the shaft in a direction to permit descent of the platform is prevented until the brake shoes are positively released by rotation of the shaft 25.

A drum 30 is fixed upon the shaft 25 and has wound around it a control cable 31 which also passes freely around pulleys 32 at the upper and lower ends of the frame A. lurnbuckles 33 may be provided for adjustment of the cable on the respective pulleys and the drum. Upon the reach of the cable 31 opposite that wound around the drum 30 are fixed stop blocks 31 to be engaged by a stop arm 35 on the platform B, one stop block being arranged at the upper limit of movement of the platform and the other stop being arranged at the lower limit of movement. The drum is preferably provided with a handle 36 whereby the shaft may be rotated by an operator standing on the floor.

Shaft 25 is also provided with a crank arm 37 which is connected by a link 38 to the crank arm 18 on the switch shaft 17, so that rotation of the shaft 25 will cause simultancously rotation of the shaft 17.

\Vith this construction, it will be observed that the cable 31 will be mo ved by engagement of the stop arm 35 with the stops 341 and will rotate shaft through the drum 30 in one direction or the other. The parts are so arranged and connected that when the shaft :25 is in the position indicated by the handle 36 illustrated in solid lines, the circuit through the switch 15 is open and the brake mechanism is applied or set. \Vhen the handle 36 is swung upwardly the brake is released and the circuit through the switch 16 is closed so that the motor 1:) rotates the drum 4 to raise the platform while when the handle is moved downwardly the brake is released and the circuit through the switch 16 is closed to cause the motor 1:") to rotate the drum to lower the platform. Obviously. when the platform reaches the lower limit of its movement the cable 31 will be moved by the sto arm 35 so as to rotate the brake shaft and the switch shaft 17 simultaneously into neut 'al position so that the brakes are automatically applied and the switch sinnlltaneously automatically opened. Similar action takes place when the platform reaches the upper limit of its movement, the handle 36 being swung downwardly into said neutral position.

It will be observed that the drum 30 serves both to maintain the cable taut and to prevent any lost motion between the cable and the pulleys 32, and also to positively connect the cable to the brake shaft. Furthermore it will be observed that the power for operating the brake and the switch is applied at the same point, that is the drum 30, whether the actuation is automatic by the platform. or by an operator on the platform grasping the cable, or by an operator on the floor grasping the handle 36. Direct, positive, quick and simultaneous actuation of the brake and the switch is accordingly ensured at all times, and there are a minimum number of simple parts so that there is little danger of failure of operation and the apparatus will be long lived and reliable even in the hands of an unskilled person. The connection of the cable 1 to the shaft through the drum 30 is such that there is no bending or flexing of the reaches of the cable as is the case where the cable is connected to a lever, and this permits the cable to be maintained taut which is not possible where some play or flexibility in the cable is required as with a lever.

It should be understood that while 1 have illustrated one specific embmliment of my invention this is prin'iarily for the purpose of illustrating the principle of the invention,

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and many modifications and changes by those a skilled in the artwithout departing from the of thesegment, respectively, so that the cable Ill is always in lines tangent to both the seg ment andthe pulleys 32: Therefore, I do not desire to be understood as: limitingmyself except as required by the following claims when construed in the light of the priorart. i

Having thus described the invention, what I claim is:

. 1. Elevating apparatus comprisinga frame, a load-carrying platform mounted to move thereon, power-driven means for moving said platform, brake mechanism for controlling said power-driven means, power-controlling means for regulating the application of ower to said power-driven means, a shaft, a rum fast mounted on said shaft, a cable movable on said frame and wound around said drum so that movement-of said cable rotates said drum, cooperating means on said platform and said cable so that the cable will be moved by said platform at certain points in the movement of said platform in opposite directions, an operative connection between said shaft and said brake mechanism, and an operative connection between said shaft and said power-controlling means, whereby said drum may be rotated by said cable to apply and release said brake mechanism and actuate said power-controlling means to regulate the power supplied to said power-driven means.

2. Elevating apparatus comprising a frame,

a load-carrying platform mounted to move thereon, power-driven means for moving said platform, brake mechanism for controL ling said power-driven means, power-controlling means for regulating the application of power to said power-drivenmeans, a shaft, a drum fast mounted on said shaft,

spaced pulleys onsaid frame, an endless cable mounted on said pulleys and having one reach wound around said drum so that move ment of said cable rotates said drum, an operative connection between said shaft and said brake mechanism and an operative connection between said shaft and said powercontrolling means, whereby said drum may be rotated by said cable to apply and release said brake mechanism and actuate said power-controlling means to regulate the power supplied to said power-driven means.

3. Elevatingapparatuscomprisingaframe, a load-carrying platform mounted to move thereon, power-driven means for moving said platform, brake mechanism for controlling said power-driven means, power-controlling means for regulating the application of power to said power-driven means and inshaft to said crank arm on the first-men tioned shaft so that movement of said cable causes application and release of said brake mechanism and respectively simultaneously therewith the shutting 0d and application of power from and to said power-driven mechanism, and cooperating means on said platform and said cable so that said platform moves said cable at certain points in the movement of said platform.

4. Elevating apparatus comprising a frame, a load-carrying platform mounted to move thereon, power-driven means for moving said platform, brake mechanism for controlling said power-driven means, powercontrolling' means for regulating the application of power to said power-driven means and including a rotatable operating shaft, a crank arm on said shaft, a second rotatable shaft, an operative connection between said second shaft and said brake mechanism, a drum fast on said second shaft, a cable mov able on said frame with an intermediate portion woundaround said drum so that said cable is operatively connected to said drum and movement of said cable rotates said drum and said drum maintains said cable taut, a

move thereon, power-driven means for mov- 7 ing said platform, power-controlling means for regulating the application of power to said power-driven means, a shaft, a drum fast mounted on said shaft, a cable movable on said frame and wound around said drum so that movement ofsaid cable'rotates said drum, cooperating means on said platform and said cable so that the cable will be moved by said platform at certain points in the movement of said platform in opposite directions, and an operative connection between said'shaft and said power-controlling means, whereby said drum may be rotated by said centric with said shaft and so that movement of said cable rotates said shaft, cooperating means on said platform and said cable so that the cable will be moved by said platform at certain points in the movement of said platform in opposite directions, and an operative connection between said shaft and said power-controlling means, whereby said drum may be rotated by said iIlJlQ, to actuate said power-controlling means to regulate the power supplied to said power-driven means.

HENRY S. GERHONILJR.

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