US1944102A - Braking apparatus - Google Patents

Description

Jan. 16, 1934.

R. MOORE BRAKING APPARATUS Filed Dec. 11, 1930 2 Sheets-Sheet 1 30500 e [V0019 6y 15,215 $2129 5 Jan. 16, 1934.

R. MOORE 1,944,102

BRAKING APPARATUS Patented Jan. 16, 1934 UNITED STATES PATENT OFFEE BRAKING APPARATUS Roscoe Moore, Kingston, Pa.

Application December 11, 1930 Serial No. 501,624

9 Claims. (01. 188174) engaged in moving cars up the slope the inertia of the cars will cause a continued travel thereof with the result that slack is formed in the cable and the cars drop back against this slack after their motion ceases, thus endangering the cable i and tending to cause breakage thereof. Accordingly, an important object of the present invention is the production of a control for the braking apparatus of such hoists of such character that the brakes cannot be applied while the hoistdrum is rotating in a direction such that the cars are. being lifted except when these cars reach their upper travel limit.

I The braking apparatus hereinbefore referred to usually includes weights which actually cause the operation of the brakes. These weights are in practically all instances held supported by a latch released through an eleotro-magneti-c means'by limit switches and over-speed or governor switches. Obviously, failure of the electric circuit including such switches will permit the elec-tro-magnetic apparatus to act to release the latch resulting in application of the brakes. Ordinarily such weights must be restored to position manually and, accordingly, the electric circuit fails for any reason during operation of the hoist there is a tendency on the part of the operator to block up the weights so that there will be no necessity for. continued manual-effort each time that the brakes are applied. This is extremely dangerous in that the operator may forget to remove the blocks from the weights when the circuit is restored thereby rendering the safety brake disastrously inoperative. Therefore, a further object of the invention is the provision of control apparatus for the brake which notonly acts to prevent operation of the brake until the hoist drum is rotating in the direction permitting the supported cars to lower on the inclined plane, but likewise to prevent operation of the brake even in event of failure of the electro-magnetic circuit until the car has reached its upper travel limit.

These and other objects I attain by the construction shown in the accompanying drawings,

wherein for the purpose of .illustration, I have shown a preferred embodiment of my invention, and wherein:

Fig. 1 is a semi-diagrammatic viewshowing braking apparatus constructed in accordance with my invention;

- Fig. 2 is an end elevation of the control mechanism; I

Fig. 3 is aside elevation partially in section thereof;

Fig. 4 is a plan view thereof; and Fig. 5 is a sectional View on line 55 of Fig. 3

showing a manner'of mounting the threaded por-' tion of the shaft.

Referring now more particularly to the drawings, the numeral 10 generally designates a hoist mechanism including a brake'B and an operating mechanism 12 for the brake of which no further description need be given other than to state that it includes a latch 12-a, an electromagnetic control element 13 controlling operation through the latch 12--a of a vertically movable bar 14 connected to the brakes B, which bar when released by de-energization of the field of the magnetic element 13 and consequent release of the latch 12a, drops under influence of weights 12b instituting operation of the brake B. Such devices are ordinarily controlled by a limit switch 15 which may be either actuated by the cage not shown or in any other suitable or well known manner. Limit switch 15 is at present disclosed as opening the circuit of an operating motor for the hoist and as opening the circuit of the electromagnetic apparatus 13 to permit bar 14 to drop. The bar 14 has preferably associated therewith a piston 14-a operating in a cylinder l4,-b, communication between the ends of this cylinder being controlled by an adjustable vent 14-0 so that the speed of movement of the piston may be regulated. When bar 14 is lowered, it maybe restored to its normal or brake-releasing position by manipulation of a manually operated reel 12-c.

In the ordinary apparatus in case of accidental opening of switch 15, or any other operation which tends to open the circuit of both the motor and the electromagnetic apparatus, or the electromagnetic apparatus alone, the operation of the apparatus 12 is immediate. It will be obvious that in the ordinary apparatus of this character a sudden application of the brake would result, and if the cage or car is at the time of application of-the brake moving upwardly, there would be a tendency of the car to continue its movement forming cable slack and causing the dangerous condition hereinbefore referred to.

In accordance with my invention, I arrange beneath the bar 14 a suitable support 18 mounting bearings 19 and 20, one of which is formed as a nut, as more clearly shown in Fig. 5. Mounted in the bearings 19 and 20 is a shaft 21 formed with threaded and plain sections 22 and 23. The plain section has splined thereto a sprocket 24 received in a furcation of bearing 20. The threaded section 22 operates through the nut of bearing 19, and has an extended end 25 to which is adjustably secured a drum 26 underlying rod 14. The lower end of rod 14 has hingedly connected thereto at 27 a foot 28, the under surface of which in the normal position of the bar closely overlies the surface of drum 26 in slightly spaced relation thereto. The foot 28 at its pivotal connection has shouldered engagement at 29 with bar 14 preventing swinging movement of the foot in one direction so that this foot when lowered upon drum 26 will, if the rotation is in one direction, remain rigid with relation to rod 14, and if the rotation is in the opposite directon, be kicked out by the drum so that it will not serve as a support for rod 14 but will permit this rod to fall. Sprocket 24 is suitably connected with the hoist mechanism as at 30 so that the shaft 21 is rotated when the hoisting mechanism is in operation. In the present diagrammatic illustration of Fig. 1, the connections are shown as direct, but it will, of course, be understood that these connections will be of such character that the shaft 21 will be given a desired speed with relation to the speed of the drum and will be rotated in the proper direction when the drum is in use in elevating the cage. During operation of the hoist the drum 26 is simultaneously rotated and longitudinally moved, the direction of rotation and longitudinal movement, of course, depending upon the direction of movement of the hoist. When the hoist is being lowered, the direction of rotation is such that the foot 28 will be kicked out by the drum and the foot rendered inoperative to prevent downward movement of the member 14 to an extent causing operation of the brakes. Application of the brakes will not occur at this time, however, unless the circuit is opened for the solenoid 13 is energized at all pther times and will not permit the member 14 to drop. When the hoist is being raised, the rotation is such that the foot 28 is not kicked out by the drum but is held in alignment with the member 14. The drum, however, due to its longitudinal travel is, when the hoist engages the limit switch, withdrawn from beneath the end of the foot 28 so that the member 14 may drop sufiiciently to cause operation of the brakes. It will, of course, be obvious that it is unnecessary that the drum travel sufficiently far to free the foot of the drum during the lowering movement and at the time that the lower limit switch is engaged, for the reason that the brakes are effective at any time that the circuit is opened during such lowering movement.

The operation of this apparatus is as follows: Assuming the hoist to be engaged in elevating the cage, if at any time prior to the operation of the limit switch 15, the circuit of electromagnetic apparatus 13 is broken, as for example, by manual switch 31, bar 14 will drop. Drum 26 will, however, check the downward fall of this bar and as a result latch 12a will not be disturbed and brake B will not be applied and as long as the hoist continues to rise, the foot 28 will remain rigid with relation to bar' 14 and will prevent dropping of the bar a distance sufiicient to cause the brake B to operate. When, however, hoisting ceases and the cage starts to drop back, movement of the drum 26 is immediately reversed with the result that the foot 28 is kicked to its dotted line position in Fig. 2, permitting bar 14 to fall and the brake to be applied. Assuming that the interruption of the circuit of electromagnetic apparatus 13 does not occur until the cage oper ates limit switch 15, then the drum 26 through operation of the screw thread 22 through the nut of bearing 19 will have shifted to the right in Fig. 3 a distance such that the foot 28 will no longer lie thereover, but will be positioned as shown in dotted lines in Fig. 3.

It will also be obvious that the construction employed is capable of a certain range of change and modification without in any manner departing from the spirit of my invention, I, accordingly, do not wish to be understood as limiting myself to the specific arrangement hereinbefore set forth except as hereinafter claimed.

I claim:

1. In combination with an apparatus having two operating phases, a control therefor including a member effective when moved to a predetermined extent, a stop for the member normally preventing movement thereof to such extent and means increasing the efiective distance between the member and stop during one operating phase of the apparatus.

2.'In combination with an apparatus having two operating phases, a control therefor including a member efiective when moved to a predetermined extent, a rotatable drum arranged in the path of the member, an interponent carried by the member and engaging the drum upon movement of the member through a distance insufiicient to render it effective, said interponent being pivoted to the member to swing in a plane transverse to the axis of the drum and having engagement with the member limiting such pivotal movement under the influence of force applied in one direction of rotation of the drum. 7

3. In combination with an apparatus having two operating phases, a control therefor including a member effective when moved to a predetermined extent, a rotatable drum arranged in the path of the member, an interponent carried by the member and engaging the drum upon movement of the member through a distance insufficient to render it effective, said interponent being pivoted to the member to swing in a plane 180 transverse to the axis of the drum and having engagement with the member limiting such pivotal movement under the influence of force applied in one direction of rotation of the drum, and means'for shifting the drum longitudinally as it is rotated.

4. In control apparatus of the character described, a longitudinally-movable bar having a foot pivoted thereto to swing in a predetermined plane, means limiting pivotal movement of the foot in one direction and while the foot is aligned with the bar, and a drum arranged in the path of the bar and in close proximity to the free end of the foot and means for rotating said drum in either direction.

5. In control apparatus of the character described, a longitudinally-movable bar having a foot pivoted thereto to swing in a predetermined plane, means limiting pivotal movement of the foot in one direction and while the foot is aligned 350 with the bar, and a drum arranged in the path of the bar and in close proximity to the free end of the foot and means for rotating said drum in either direction, and for shifting the drum longitudinally.

6. In combination with an apparatus having two operating phases, a control therefor including a member eifective when moved to a predetermined extent, a stop for the member normally preventing movement thereof to such extent, means increasing the effective distance between the member and stop during one operating phase of the apparatus, and means for withdrawing the stop from the path of the member after a predetermined duration of the other operating phase of the apparatus.

7. In combination with a reversely operable hoist, a brake for the hoist, an actuator for the brake including a longitudinally shiftable member, a drum arranged in the path of the longitudinally shiftable member and operated from the hoist and a foot for the longitudinally shiftable member rigid thereto against forces applied to the foot by rotation of said drum in one direction and pivoted with relation thereto under the influence of forces applied by rotation of the drum in the opposite direction while the foot is engaged therewith, said foot engaging said drum prior to movement of the longitudinally shiftable member through a distance rendering the brake efiective.

8. In combination with a reversely operable hoist, a brake for the hoist, an actuator for the brake including a longitudinally shiftable memher, a drum arranged in the path of the longitudinally shiftable member and operated from the hoist a foot for the longitudinally shiftable member rigid thereto against forces applied to the foot by rotation of said drum in one direction and pivoted with relation thereto under the influence of forces applied by rotation of the drum in the opposite direction while the foot is engaged therewith, said foot engaging said drum prior to movement of the longitudinally shiftable member through a distance rendering the brake effective, and means for shifting the drum longitudinally as it is rotated.

9. The combination with a member to be raised and lowered of a hoist for raising the same, means to limit the raising operation of the hoist, a normally inoperative brake for the hoist, an actuator for said brake, means effective only during operation of the hoist to raise the member for rendering the brake-actuator inoperative, and means to render the last-named means inoperative when the limit means is operated.

ROSCOE MOORE.

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