US2371865A - Counterweight control system for lifting device carriages - Google Patents

Description

March 20, 1945. 2,371,865

COUNTERWEIGHT CONTROL SYSTEMS FOR LIFTING DEVICE CARRIAGES P. J-M. T. ALLARD a o T E v N \a ierre Tean-Mqn eTWeodoRN N g rr Y.

Patented Mar. 20, 1945 ooUNTEnWErGH'r ooN'mon srs'rnmg'ron LIFTING DEVICE OARRIAGES Pierre Jean-Marie Theodore Allard, Chantilly, France; yested in the Alien Property Custodian ApplicationF ebr uary 1, 1943, Serial e. 474,326 In France Marclijll, 1941 Claims. ((1212-84)- My invention relates to lifting devices of the type including a horizontal or slightly inclined guideway' along whicha carriage is adapted to run, to which crab is hung an automatic grab or like goods-handling device, said carriage advancing in a given direction under the action of a counterweight adapted to return the carriage towards the discharging position- The invention is; more particularly. applicable to the apparatuses of the type described in my prior specification Ser. No. 282,817, filed on July 4, 1939, now Patent No.'2,270,91 6, granted January 27, 1942.

Said invention has for its object a countenweight control system forreturning the carriage towards the discharging position and adapted to stop the carriage at a predetermined point of its return travel. To this end, according to the invention, an adjustably positioned stop is arranged in the path of the counterweight so as to balancethe action of the latter and to stop the carriage at the desiredpoint. a

In the .case of an automatic grab of the type described in the above mentioned prior specifica-' tion, this stopping of the carriage produces at the'sarne moment the automatic emptying of the grab through the slack given to the lifting cable to which-the grabis suspended. Other features of the invention will: appear from the following description, reference being made to .the accompanying drawing in which;

' Fig. 1 is a diagrammatic viewof a first form of the invention.

weight stop, including a single stop adjustably weight It.

arranged in thefsame longitudinal vertical plane as theicable 2. A lever B is pivotally secured as at- 9 to thecarriage 4, said lever being provided with a counterweight or aspring 10 for urging brake shoe 36 into contact with the rail or guidewayi.

When in position for loading over the axis, AB,

the carriage abuts against the. stop I I under the actionof the weight of the grabsuspended to the cable, 2.

The carriage is urged to .theright in Fig. 1, by thereturn system, including a cable 12 passing over a return pulley l3 and to the end of which is suspended a driving counterweight I 4.

In the forrnof execution of Fig. 1, a rotary rod I5 is arranged parallel to the path of; the counterweight M. Rod 15 is provided at different heights with fingers l6, l1, l8, which fingers project-radially. at difierent angles from the rod and serve as stops when moved into the path of the. counterweight. Rod I5 is mounted in bearings l5a and (5b attached toa stationary object.

In the form of execution illustrated inFigsIZ and 2'A, 2I designates one of the stops distributed at different heights along the path of the counterv This stop is carried by a lever 22 adapted'to pivot round a stationary axis 23 said stop being urged in'one direction by a spring 24 and-in the opposite direction by the armature empties its contents between two extreme points corresponding to the extremities of the path allowed for the adjustable stop.

Referring to the drawing, 1 designatesan automatic grab, secured to the end of a hoisting cable 2 passing over a return pulley 3 carried by a carriage or trolley 4, the rollers 5 of said trolley running along .a. horizontal or slightly inclined rail '5. The opening ring I is suspended by a cable 25 of a coil 26. Coil 26 is inserted in the circuit of 1 a current supply 21, which circuit has a switch 28. Normally, the switch 28 being open, the spring'z l urges thelever 2 2'into the position shown in dot and dash lines, for which th stop 2| is no longer in the path of thecounterweight I4. Whenthe switch 28 is closed,v the coil '25 attracts its armature 25 which, in turn, brings the stop 2! back into the path of the counterweight. I

.H'I hestops '21 oscillate back and forth in slots ing rotation of the rod, a motor constantly r0- tating the nut, and means controlled by the stop at two points of its travel for reversing the direction of rotation imparted to the nut. l

10.- In a lifting device including a substantially horizontal guideway, a grab, a carriage carrying said grab and adapted to move along the guideway between loading and discharging positions,

a descending counterweight for returning the grab towards the discharging position, abutment means for stopping said descending counterweight, and means for adjustably moving said abutment means along the path of the counterweight to different obstructing positions.

PIERRE JEAN-MARIE I THEODORE ALLARD.

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