US2498422A

US2498422A - Hoist safety device

Info

Publication number: US2498422A
Application number: US27741A
Authority: US
Inventors: Edward O Hermann
Original assignee: Individual
Current assignee: Individual
Priority date: 1948-05-18
Filing date: 1948-05-18
Publication date: 1950-02-21
Anticipated expiration: 1967-02-21

Description

Feb. 21, 1950 E. o. HERMANN HOIST SAFETY DEVICE Filed May 1a. 1948 2 Shets-Sheet 1 IN V EN TOR. I [O WW'O 0. Her/mm B Y Feb. 21, 1950 E. o. HERMANN ,4

HOIST SAFETY DEVICE Filed May 18, 1948 2 Sheets-Sheet 2 fc/Wa/o 0. Herman/7 A 7' 7' GPA/i 75 Patented Feb. 21, 1950 U N [TE D S TATES' FlfiE- yl HOIST SAFETY DEVIGE' Edward 0. Hermann, Mill Valley, Calif. Application May 18,- 1948;'SerialNo.- 27,74 1

C .a mS.- 71- 'I-hisinventionrelates to a .hoist safety device cars and inlowering the same at. thepoint' of destination, it is desirable to provide emergency support for the load intheevent. of failureof the hoistingapparatush Such emergency support is desirably operable to provide support both during hoisting and lowering, and it is also desirable that itbe actuated only in the event of a sudden dropping of the load so as .not to interfere withnormalhoisting or loweringthereof. Safety supports for this purpose heretofore in use are-makeshift,--do not .provide support at all times when needed, or require considerable manepower in their handling.

It'isanobject ofthe invention to provide an improvedhhoist safety device.

It is a further object of the invention to provide ahoist safety device which is operative to provide. support for loads, both during hoisting and lowering of the same, in the event :of failure of the hoisting..apparatus.

It is a still further object ofthe invention to.

provide a-hoist safety device which is' adapted to use .eitheras a separate, transportable device.

which canbe. used wherever needed, or which can be installed as a permanent fixtureinafreightcar, ona loading platform, or wherever else it may be desired.

It'isa particular object of the invention to provide a hoist safety device for use in conjunction withauto'. racks infreight cars fulfilling several. or. all of the .desiderata detailed hereinabove.

These .and otherobjectsof the invention will bebetter understood by reference to the ensuing description and the, appended claims.

One form which the invention may assume is Fig.4 illustratesdiagrammatically how the de--;

vice of; the invention maybe used as a movable hoist support.

Fig. 5 illustrates diagrammatically how the device-of the invention may be used as a permanent fixture, as in a freight car.

Referring now-to the drawings, and more particularly to Figs. .1 and 2,- a load is indicated. at l,,such,' forexample as the angle of a conventional autoframe rack usedtohoist and support,

an automobile inafreight car. Emergency support for. the load,.in the event of failure o'f the hoisting apparatus; is provided by means of a co1umn2 and a mechanism generally designatedas 3. As. shown, the column 2 is provided with opposing sets of rack teeth 4, and the column is I of relatively large transverse dimensions so as to-be. capable of supportinga large load under compression.

The. mechanismscomprises a box lfl serving both as a. closure for the working parts-of the mechanism and as a framework for their support. As shown, the box I0 is provided with upper and lower openings and I2 adapted to receive the column 2 and to allowfree movementof the box up. anddown the :column. Disposed-within the box, near the bottom thereof, is-a base-o1' casting 13 having a central opening 14 adapted toreceive the. columnZ and to allo w-free-move ment ofthe base up anddown the column The base. is supported upon coil springs l5,swh-ich are normally .under a degree of compression determined by the: weight ofthe'base I3 and elements supported thereby .and which. rest upon thefloorof the box. A pair'of emergency supporting pawls; 16 :havingteeth. or: fingers IT: adapted toengagethe-rack teeth 4 of the column,-

are provided .on oppositeusides of thec'olumn;

each such'pawl' being pivotally' supported upon-a shaft [8 carried in bearings 19 which are suitably' secured to the side walls of the box. HIV The lower-end of each pawl I6 is connected to a link ZS-by'meansof-a joint 26, and the'inner end of each link 25 ispivotally connected at :21 to a shaft 28 carried in brackets 28a extending up-. wardlyifromand integralwith the base l3. Also,

eachpawl is urgedinwardly,.that is, soas to engage its, fingers with the rack teeth 4 of the column 2, by a coil spring. '29 received within asocket 341 formedin the pawl and compressed between the. pawl and the end wall of the box.

It, will be understood that each of the coil. springs I5 and -29 maybe anchored by any suitable means'toprevent accidental displacement.

A, cam 3| 'pivotallyand eccentrically supported upon a shaft 32, and a roller 33 mounted on a shaft 34, carriedain brackets'35; are provided for the purpose of manuallyactuatingzthe supporting pawls IS in the manner and for a purpose hereinafter described. Theshaft 32 extends through and outwardly of the front wall of the .box, and to its; outer end is secured a lever or crank40: having an arrow-shaped head d serving. as a pointer for a purposeexplained hereinafter.

A pair of escape pawls ll, each having a finger-v mare also provided on opposite sidespfthe column. Each such escape pawl ispiyotallysupported upon-a shaft 42 carried inbearings 43': suitablyanchored in the-sidewallsof the-box Ill, and, the lower end of each escapepawl: 4| "is:- pivotally connected at 44';-toa link- 45; the other;: endof which is pivotallyconnected to.;a pendulum; 46.- r The pendulum, 46 Iisgpivotally-supported ate 41 by a pendulum support 48, which in turn is supported for linear and angular movement by means of a shaft 48a carried in a bearing suitably anchored in the front wall of the box In and received within a slot 49 formed in the top. of the pendulum support, and by means of a pivotal connection 50 with the center of the cam 3|.

The mechanism is further provided with a plunger 55 secured to or integral with the base l3. The plunger 55 extends upwardly through an opening 56 formed in the top of the box Ill, and it is provided with a, support bracket or foot member 51 at its upper endabove the box. Also, the mechanism is provided with a chain and hook 58 for a purpose described hereinafter.

The device as thus far described operates as follows: Referring to Fig. 4, and assuming it is desired to provide support during lowering an automobile (not shown) supported on a standard auto rack i in a freight car, a column 2 will be positioned on each side of the freight car and at thefront end of the rack, as shown. Support for the columns 2 may be provided by means of blocks 60 secured to the floor Bl of the freight car, and by engaging the top of each column with brackets (not shown) at the top of the freight car, such brackets being well known, standard equipment.

,Next, each box in is elevated to the position shown, with the bracket 51 adjacent the load and with the pointer 40a directed downward. The various pawls and links will then be in the positions shown in Fig. 1, in which, it will be noted, the supporting pawls l6. are held out of engagement with the rack teeth 4 of the column. As the load is lowered, a downward force is exerted on whichever of the escape pawls 4| is in contact with a rack tooth of the column. The shape of the fingers Ala on the escape pawls is such that by engaging the rack teeth 4 on the column, either pawl will support the weight of the box and its associated elements at any desired position on the column. However, the added weight of a load, as the same is lowered, is sufficient to displace or rock whichever pawl is in contact with the rack teeth, th-us rocking the pendulum 46. It will thus be' seen that the pendulum 46 and escape pawls 4| will oscillate and will thus cause the box it] to travel downwardly along the column at the rate of lowering the load. The pendulum is effective, by reason of its period of oscillation, to control the rate of travel of the box down the column. Preferably, a short pendulum having a short period is employed, thus rapidly accommodating the rate of chain and hook 58.

4 shown in Fig. 3, thus engaging the support pawls It with the rack teeth 4 of the column. It will also be seen that such movement of the cam through 180 will also rotate the pivot point 5!! of the pendulum support 48 through an equal angle, thus displacing the pendulum support downwardly and actuating the escape pawls 4! through the medium of the links so as to completely disengage them from the rack teeth of the column. The support pawls [5 are meanwhile held by the coil springs 29 firmly in engagement with the rack teeth of the column, so as to prevent falling of the load in the event of failure of the hoisting apparatus. As the load is hoisted, the box it will follow it up the column since it is secured to the load by the The upward force exerted on the load by the hoisting mechanism will disengage the support pawls [6 from the rack teeth 4 suificiently to allow upward travel of the box, but at all times support is provided in the event 'of sudden falling of the load.

Referring again to Figs. 1 and 2, an auxiliary feature may be provided, if desired, to ensure that the escape levers 4! will support the weight of the box it and elements associated therewith when the box is not under an added load. This auxiliary feature comprises a lever 10 pivotally supported at 1i, as shown, having a weight 12 depending therefrom and overlying the pendulum 46 and normally pivoted out of engagement with i the pendulum by a coil spring 13 compressed between the opposite end of the lever and the top of the box If A rod 14 reciprocably disposed within the plunger is thrust upwardly by a coil spring 15 disposed within a recess in the plunger .75, ,such that its upper end projects above the bracket 51 and a pin 11 projecting from the rod pivots the lever it against the tension of coil spring 13 so as to press the weight 12 against the pendulum 46, thus preventing it from oscil- 1 'lating. However, when a load is imposed on the bracket 51, as during lowering of a load, the rod 14 is depressed, th-us disengaging the pin 11 from the lever 19 and allowing the pendulum and support pawls to operate.

Referring now to Fig. 5, the device of the invention is shown adapted to use as a permanent car fixture. The column 2 is secured to the floor BI and roof 80 of'a freight car, and it is inverted, with the rack teeth 4 in reverse position as compared with the position shown in travel of the box to changes in the rate of low- This will result in actuating the support pawls 7 [650 as to engage the same with the rack teeth 4 of the column, as shown in Fig. 3. Suflicient support is thus provided almost immediately to prevent further falling of the load.

Assuming now that it is desired to provide emergency support for the load during hoisting of the same, the chain and hook 58 are engaged with the load and the pointer 40a is moved into upward position as shown in Fig. 3. This movement of the pointer will rotate the cam 3| which, bearing against the roller 33, will depress the base l3 and compress the coil springs l5, as

Fig. 1. The column 2 may also be of smaller dimensions, as indicated, since it is under tension rather than compression. The box It, shown diagrammatically, is also inverted, and

the auxiliary features identified as 10 to 11 are secured at one end to the load I, is trained over a pulley 82 secured at or near the roof of r the freight car as shown, passes through appropriate openings (not shown) in the box structure and is secured at its other end to a counterweight 83 abutting the bracket 51 at the lower end of the plunger 55.

In operation, the adaptation shown in Fig. 5 functions similarly to that shown in Figs. 1 to 4,

except that the box lfi and counterweight 83 move oppositely to the load. On failure of the load during lowering, the counterweight 83 is raised by the cable 8!, thus compressing the identical with the coil springs l5 and engaging the support pawls I6 with the rack teeth 4. Desirably, in this adaptation of the device, the coil springs l5 are somewhat larger and stronger than in the movable device of Figs. 1 to 4. It will be understood, of course, that the cable 8| does not normally carry a load except for the weight of the box I!) and counterweight 83.

While I have shown the preferred form of my invention, it is to be understood that various changes may be made in its construction by those skilled in the art without departing from the spirit of the invention as defined in the appended claims.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. A hoist safety device comprising a main load supporting member adapted to rest upon and support a load above a floor, a frame movable longitudinally of said main member, an auxiliary load supporting member pivotally supported by said frame and pivotable into and out of engagement with said main member, co-engaging means on said main and auxiliary members adapted to look the members together when said co-engaging members are in engagement, resilient means for actuating said auxiliary member, said resilient'means being such as to pivot said auxiliary member into engagement with the main member on compression thereof, means responsive to sudden lowering of the load operative to compress said resilient means and oscillatory means for restricting the rate of downward movement of said frame.

2. A hoist safety device comprising a load supporting column having a rack disposed longitudinally thereof, a frame movable longitudinally of said column, a pawl pivotally supported by said frame for pivotal movement into and out of engagement with said rack, resilient means supported by said frame, means connecting said resilient means and pawl for pivotal movement of the pawl into and out of engagement with said rack upon compression and expansion, respectively, of the resilient means, means responsive to a sudden lowering of the load for compressing said resilient means and oscillatory means for restricting the rate of downward movement of said frame.

3. A hoist safety device comprising a load supporting column having a rack disposed longitudinally thereof, a frame, a pawl pivotally supported by said frame for movement into and out of engagement with said rack, resilient means supported by the frame, means connecting said resilient means and pawl for pivoting said pawl into and out of engagement with said rack upon compression and expansion, respectively, of the resilient means, means responsive to a sudden lowering of the load for compressing said resilient means, and independent means for compressing said resilient means comprising a member eccentrically and pivotally supported by said frame and adapted in one angular position to compress and in another angular position to release compression of said resilient means.

4. A hoist safety device comprising a load supporting column having a rack disposed longitudinally thereof, a frame, a pawl pivotally supported by said frame for movement into and out of engagement with said rack, a coil spring supported by the frame, a rigid member supported by said coil spring and free to move relatively to said frame and longitudinally of said column upon compression and expansion of said spring, said rigid member being provided with a longitudinal member adapted to bear against a load, and a link connecting said rigid member and said pawl for pivotal movement of said pawl into engagement with said rack upon compression of said spring.

5. A hoist safety device comprising a vertically disposed rack adapted to support a load, a frame movable longitudinally of said rack, a pawl pivotally supported by said frame for pivotal movement into and out of engagement with said rack, resilient means for pivoting said pawl into and out of engagement with said rack on compression and expansion, respectively, of the resilient means, means responsive to sudden lowering of the load for compressing said resilient means, independent means for compressing said resilient means, and other resilient means for holding said pawl yieldably in engagement with said rack.

6. In a hoist safety device comprising a rack adapted to be positioned vertically and to support a load when in vertical position, a frame, a pawl pivotally supported by the frame for pivotal movement into and out of engagement with said rack, and means responsive to load pressure for pivoting said pawl into engagement with said rack but normally holding said pawl out of engagement therewith except in response to sudden lowering of the load, the improvement which comprises a second pawl pivotally supported for movement into and out of engagement with said rack, said second pawl being such as to support the weight of said frame and elements supported thereby upon said rack when in engagement therewith but such as to be rocked out of engagement by the added weight of a load, and a pendulum supported for oscillatory movement and connected to said second pawl, said pendulum being operable to return said second pawl to rack-engaging position.

7. Ina hoist safety device comprising a vertical rack having two opposed sets of rack teeth on two sides thereof, a frame, a first pawl pivotally supported by said frame for movement into and out of engagement with said rack, resilient means operable to engage and disengage said first pawl with said rack upon compression and expansion, respectively, of said resilient means, and means responsive to a sudden lowering of the load operable to compress said resilient means, the improvement which comprises an escapement mechanism for supporting the weight of said frame and elements supported thereby at any desired level on said rack, but allowing downward movement thereof relative to the rack in response to lowering of a load, said mechanism comprising a pair of opposed escape pawls each pivotally supported to move into and out of engaging position with respect to one of said sets of rack teeth, each said escape pawl being adapted when in en gaging position to support said weight but such as to rock out of said position under an added load, and a pendulum supported for oscillatory movement and pivotally connected to each escape pawl to control the rate of movement of said frame relative to said rack.

EDWARD O. HERMANN.

REFERENCES CITED UNITED STATES PATENTS Name Date Taylor Mar. 29, 1898 Number