US767817A - Automatic brake and safety device for hand-cranes. - Google Patents

Description

No. 767,817. A I PATENT'ED AUG. 16, 1904. E. R. INMAN. AUTOMATIC BRAKE AND SAFETY DEVICE FOR HAND GRANES. APPLIOATION FILED D20. 1a. 1903.

NO MODEL. 2 SHEETS-SHEET 1.

FIG. 1.

uwnloc Witness I W 5'2 MW 4) No. 767,817. PATENTED AUG. 16, 1904.

' E. R. 'INMAN. AUTOMATIC BRAKE AND SAFETY DEVICE FOR HAND GRANES.

APPLICATION FILED DBO. 18. 1903. NO MODEL.

2 SHEETSSHE BT 2.

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Patented August 16, 1904.

UNITED STATES PATENT OFFICE.

EDWARD R. INMAN, OF FRANKLIN, PENNSYLVANIA, ASSIGNOR TO JOHN P. FRAZIER AND ED. D. SMITH, OF FRANKLIN, PENNSYLVANIA.

AUTOMATIC BRAKE AND SAFETY DEVICE FOR, HAND-CRANES.

SPECIFICATION forming part of Letters Patent No. 767,817, dated August 16, 1904.

Application filed December 18, 1903. Serial No. 185,709. (No model.) i I T (til whom, it may concern.-

Be it known that I, EDWARD R. INMAN, a citizen of the United States, residing at Franklin, in the county of Venango and State of Pennsylvania, have invented certain new and useful Improvements in Automatic Brakes and Safety Devices for Hand-Cranes, of which the following is a specification, reference being had therein to the accompanying drawings.

My invention relates to an improved automatic brake and safety device for hand-cranes, the construction,object, and operation of which are herein fully set forth, reference being had to the accompanying drawings, which form a part of this specification, and in which- Figure 1 is a side elevation of a portable hand-crane embodying my invention, a portion of the standard being broken away to expose the drum to view.

Fig. 2 is a rear view of Fig. 1. Fig. 3 is an enlarged view of the drum and a portion of each standard, the end of the drum which contains the brake being shown in section in order to show the detailed construction of the brake. Fig. 4 is an end view of the drum, showing the brake-lever.

My device is designed especially to be applied to a portable hand-crane primarily for the purpose of automatically preventing or arresting the unwinding of the drum in the case of an accident, and thus it performs the oflice of a safety device. It may also be used as a means of controlling the retrograde motion or unwinding of the drum, and when thus used it performs the functions of a brake.

The elements of my device, as illustrated especially in Figs. 3 and 4, are as follows: 1 and 2 are the jib-standards of the crane. 3 is the drum-body. L and 5 are the flanges of the drum. 6 is an internally-screw-threaded cone, a seat 6 for which is provided in the end of the drum. 7 is a stud or stub-shaft rigidly afliXed to standard 1 by means of the plate 7 and the screws 7", said stub-shaft being provided on its inner end with a screw-thread upon which is operably screwed the truncated cone 6. 8 is a handle or lever rigidly attached to the cone for the purpose of manipulating the same. 9 is a counterweight attached to the lever for the purpose of holding the cone always in contact with its seat. The drum 5o winds up inthe direction indicated by the arrow a and unwinds in the direction indicated by the arrow 6.

The operation of my device is as follows: hen the drum is being wound up and turned in the direction indicated by the arrow at, the friction of the drum upon cone 6 causes the same to turn in unison with the drum or to tend to do so; but the thread in the cone also tends to draw thecone away from its seat until the frictional resistance between said cone and seat becomes so small that the cone ceases to turn, and the drum is free to continue turning in this direction until the load to which cable 10 is attached is drawn to the desired height. 5 It will be noted, however, that the function of the counterweight 9 is to cause a continuous impingement between the truncated cone 6 and its seat 6 and that when the drum starts to revolve in the direction indicated by the 7 arrow 5 the friction between the cone and its seat, together with the action of the counterweight, cause said cone to turn upon the screw and to arrest the motion of the drum in this direction, which is the unwinding or retro grade direction. When it is desired to have the drum continue to unwind, the cone may be manipulated by means of the lever 8 in such a manner as to permit the drum to revolve at any desired speed. The drum is here 30 shown mounted upon a shaft '11, whichpasses entirely. through the same and through the stud or stub-shaft. In order to prevent any endwise motion of the drum 3, the end of the stub-shaft is caused to bear against the drum, 5 and by placing a liner 12 between the plate 7 and standard 1 an accuracy of adjustment may be obtained by which the above-mentioned result is readily attained.

Having thus described my device, what I 9 claim as new, and desire to secure by Letters Patent, is

1. In an automatic brake and safety device for hand-cranes, the jib-standards of said crane, a hoisting-drum mounted between said standards, a friction device mounted upon one of said standards in juxtaposition to one end of said drum and adapted to press thereon,

means of automatically causing said pressure to decrease when the drum is revolved in one direction and to increase when said drum is revolved in the opposite direction, and means of manually actuating said device substantially as and for the purpose specified.

2. In a portable hand-crane, a drum having a taper seat in one end thereof, a truncated cone operably mounted upon screw-threaded stub-shaft and seated within the taper seat aforesaid, a lever attached to said cone, substantially as and for the purposes specified.

3. In an automatic brake and safety device for hand cranes, a hoisting drum suitably mounted upon the j ib-standards of such crane,

a friction device suitably mounted upon one of said standards in juxtaposition to one end of said drum and adapted to impinge therewith, means of automatically causing said impingement to decrease when said drum is revolved in one direction and to increase when the drum is revolved in the opposite direction.

In testimony whereof I afiix my'signature in presence of two witnesses.

EDWARD R. INMAN.

Witnesses:

Buss L. BLACK, EDWARD E. HUGHES.

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