US1091829A

US1091829A - Lifting device.

Info

Publication number: US1091829A
Application number: US76401113A
Authority: US
Inventors: Randall D Gardner
Original assignee: Individual
Current assignee: Individual
Priority date: 1913-04-28
Filing date: 1913-04-28
Publication date: 1914-03-31
Anticipated expiration: 1931-03-31

Description

R. D. GARDNER. LIPTING DEVICE.

APPLICATION FILED APR. 28, 1913. 1,09 1,829. Patented Mar. 3 1, 1914,

' 2 QHEETs-SHEET 1.

R. D. GARDNER.

LIFTING DEVICE. APPLICATION FILED APR. 2a, 1913.

Patented Mar. 31, 1914.

2 SHEETS-SHEET 2.

| I l I I I I I I l L I l I I l l l ll LVVE/VTOR. Mu bw IVJTNESSES:

ATTORNEY.

in ra mar anion.

RANDALL I). GARDNER, OF BOSTON, MASSACHUSETTS.

LIFlINGr DEVICE.

Specification of Letters IPatent.

Patented Mar. 31, 1914.

1/ b all whom it may concern Be it known that. I, RANDALL D. GARDNER, of Boston, in the county of Suffolk and State of Massachusetts, have invented a new and useful Lifting Device, of which the following is a specification.

The chief objects of my invention are to provide simple but quick, accurate and citicient mechanism for lifting heavy loads and particularly the ends of draw-bridges and my invention consists partly in a device for raising the member to be lifted so that a bearing block may be inserted, partly in means for centering the device, partly in means for preventing movement after the device is in place and partly in a mechanical automatic control for an electric motor which operates the mechanism although this automatic device is useful for other purposes.

In the drawings: Figure 1 is an elevation of a device embodying my invention; Fig. 2 is a plan of the same; Fig. 3 is a detail showing the centering mechanism; Fig. l is a detail of a modification; Fig. 5 is an elevation of the automatic mechanism for operating the reversing switch; and Fig. 6 is an end view of the same.

The lifting device may be attached to the member to be lifted in any suitable way and in the case of a drawbridge it may be attached to the girders, floor-beams or as shown in the drawing to a frame A suspended under the ends of the draw. Links a a form with the gear segments or actuators Z) Z) toggle joints for forcing the lower end of the lifting links 0 0 forward, link a being pivotally connected to segment Z2 at j and also pivotally connected to links 0, the latter being pivoted at their upper ends to swing on pin (Z. At the lower end of links 0 are pins 6 upon which one or more rolls 00 m are mounted, these rolls taking the weight of the load at the time of lifting. Sliding block 7 is slightly beveled on its lower face and is mounted to slide in guides g 9' attached to the bottom of frame A and has a pin and slot connection with links it la, the other end of links it it being pivotally connected at if to the segments Z) Z).

B is a bearing block fixed to the draw landing in the form shown upon which block the rolls a" 02 move when lifting or lowering the load and upon this bearing block the sliding block 7 rests when it is supporting the ends of the draw or other member. In Fig. 3 I show the beveled edges 6 b and these are engaged by the rolls :0 as they are forced forward and the result is that the end of the draw-bridge is brought to an accurate central position and the rolls remaining one on each side of the raised portion 6 of the bearing block B lock the draw against turning until they are withdrawn as hereinafter described. At either side of the raised portion 6 are the curved tracks 19 upon which the rolls w w ride to lift the end of the drawbridge for insertion of the sliding block and as the rolls then move along the horizontal portion o it will be clear that the end is lowered so that the sliding block rests upon the bearing block giving a rigid support to the drawbridge.

When the end of the drawbridge is to be released the gear segments are moved upward on the shaft in, this movement causing the rolls w x to swing to the right on an arc with reference to the pin (Z, which movement along the horizontal portion 6 elevates the end of the drawbridge and thus releases the sliding block 7 which, on account of its sliding connection with link it, does not move until the end has been lifted to a sufficient extent but further movement of the segment 6 draws the sliding block along its guides until it reaches the dotted position shown in Fig. 1. In the meantime the movement of the rolls down the inclines 79 allows the end of the drawbridge to drop to its lowered position. When the gear segments 1) are in their highest position the block f and rolls 00 are fully withdrawn as shown in dotted lines at as" and f allowing the ends of the drawbridge to swing clear of the bearing block B. In the reverse operation for lifting the drawbridge the gear segment starts downward and thrusts the rolls m to the left (as shown) and these rolls ride up the inclines 5 and raise the drawbridge away from the bearing block, the sliding block 7 being in the meantime, owing to the pin and slot connection, at rest but when the slot has completed its travel over the pin then the sliding block is moved along its guides into position over the bearing block. Ihe first effect of movement of the rolls is to center the drawbridge and later the rolls raise the end and allow the sliding block to be moved into operative position,

the sliding block having the faster movement owing to the position of the pin it on the segment and then as the rolls move along the horizontal portion 6 the end of the drawbridge is lowered and the weight is transferred to the sliding block 1, the rolls locking the end of the drawbridge against movement until they are subsequently withdrawn.

r The bearing block may be of the shape shown in Fig. 1 or of any other suitable shape an example of which I have shown in Fig. i, the parts being lettered as in Fig. 1, but the bearing block being guided in guides g which are at an angle with frame A and said block being in a slightly different location with reference to link 0 the latter, in the position shown, holding member A in its highest position and movement of the rolls in either direction lowering member A. The automatic 'mechanical device for controlling the motor D which operates the lifting mechanism is shown on a larger scale in Figs. 5 and 6 in which N is a suit-able frame or support in which turns shaft n which is adapted to-engage nut 79 the latter engaging an adjusting screw 1' when moving in one direction and another adjusting screw 1" when moving in the opposite direction. As the nut 79 is prevented from rotating by the guide '3 it moves longitudinally and therefore moves the adjusting screw and as the latter is mounted on rack q said rack will be moved and said rack engages teeth on gear segment .9. As segment s moves on shaft mto the position shown in Fig. 5 it raises the weight t and as the'center of gravity of the latter passes the vertical it tends to drop to the right in Fig. 5. This tendency is for a time retarded by a spring pin engaging guide 20 in member 25 but when the latter has fallen sufficiently it releases itself from the spring pin and falls with a sharp quick blow onto gear segment a, turning on shaft m, and segment a then turns shaft '0 through 90 to reverse the switch indicated at E.

\Vhen the motor I) is started the turning of the screw shaft n which is part of, or geared to, the motor causes the nut 79 to move longitudinally and thereby, through the rack '9' and segn'ient 8 lift the weight until thelatter passes the vertical and then it falls, giving a blow which quickly shuts ofi the current, leaving the motor in position to start in the opposite direction in which case shaft it rotates in the opposite direction carrying nut 72 in the opposite direction and turning segment 8 in the opposite direction, raising the weight from its position at t until it passes the vertical when it drops with a quick blow on the other end of segment at which then rotates and reverses the switch. It will be clear that my automatic mechanical control may be accomplished by means of various actuating mechanisms and any suitable connections may be made between shaft n and shaft 76. If desired shaft is may be turned by hand or a suitable hand operated rotating device although I prefer the use of a motor so that the operation may be controlled from some remote place.

A reat advantage of my automatic mechanical device is that it does not get out of order when exposed to moisture as might be the case with electrical control and this consideration is particularly important in the case of drawbridges.

What I claim is:

1. A lifting device comprising a fixed bearing; a rotary member to be lifted; a sliding block; means to move the member to be lifted away from said bearing, said means including a member cooperating with the fixed bearing to adjust centrally the member to be lifted; means to insert the sliding block between said bearing and said member when the latter is lifted, said moving means being movable while the block is stationary; and an actuator to actuate both of said means.

A lifting device comprising a fixed bearing; a rotary member to be lifted; a

sliding block; means to move the member to be llfted away from sald bearing, said means including a. member cooperating with the fixed bearing to lock said member against rotation; means to insert the slid ing block between said bearing and said member when the latter is lifted, said moving means being movable while the block is stationary; and an actuator to actuate both of said means.

3. A. lifting device comprising a member to be lifted, a fixed bearing having beveled faces and a track; rolls pivot-ally connected to the member to be lifted, the pivot being at a greater distance from one portion of the track than from another port-ion and the bearings for the rolls being connected together rigidly, said rolls engaging said beveled faces to center said member and riding upon said track to move said member away from, and allOw it to move toward, said bearing; a beveled sliding block; a reciprocating rotary member; means to move the latter; a link connection between the rolls and the rotary member; and a link con nected to therotary member and having a pin and slot connection with the sliding block, all combined to move the member to be lifted away from the fixed bearing for insertion of the sliding block and for lowerthe sliding block between said bearing and said member when the latter is lifted, said moving means being movable while the block is stationary and an actuator to actuate both of said means.

5. A lifting device comprising a fixed bearing; a member to be lifted, a sliding block, means to move the member to be lifted away from said bearing; means to insert the sliding block between said bearing and said member when the latter is lifted, said moving means lowering said member on to said block after said insertion and said moving means being movable while the block is stationary and an actuator to actuate both of said means.

(3. A lifting device comprising a fixed bearing; a member to be lifted, a sliding block, means to move the member to be lifted away from said bearing; means to insert the sliding block between said bearing and said member when the latter is lifted, said moving means lowering said member on to said block after said insertion, said block being immovable when the load of said member rests upon it and an actuator to actuate both of said means.

7 A lifting device comprising a fixed bearing; a member to be lifted, a sliding block, means including a toggle joint to move the member to be lifted away from said bearing; means to insert the sliding block between said bearing and said member when the latter is lifted, said moving means lowering said member on to said block after said insertion; and an actuator to actuate both of said means.

8. A lifting device comprising a fixed bearing; a member to be lifted; a sliding block; means to move the member to be lifted away from said bearing; means to insert the sliding block between said bearing and said member when the latter is lifted, said inserting means including a link having a pin and slot connection With said block, said moving means lowering said member on to said block after said insertion; and an actuator to actuate both of said means and having during all its operation simultaneous movement wit-h said moving means and having direct connection with said link.

9. A lifting device comprising a fixed bearing; a member to be lifted; a sliding block; means to lift said member away from said bearing and to lower it onto said block; an actuator to actuate said means and to insert said block between said member and said bearing; means connecting the ac tuator and lifting means to provide movement of the lifting means during all the operation of the actuator; and means connect ing the actuator and block and having provision for relative movement between them during a portion of their operation, all combined to raise said member for the insertion of said block and to lower said member onto said block after the latter has been inserted and to raise said member while the block is stationary.

10. A lifting device comprising a member to be lifted; a fixed bearing; a movable block to rest on said bearing and to support said member; means engaging said bearing to lift said member away from said bearing and to lower it onto said block; and an actuator for operating said lifting means and. also for inserting said block between said bearing and said member and for withdrawing it; and a connection between the actuator and block to allow the block to remain stationary during a portion of the movement of the actuator.

11. A lifting device comprising a member to be lifted; a fixed bearing; a sliding block; a link pivotally connected to said member and adapted to ride on the fixed bearing; a pivoted actuator; a second link connecting the first link with the actuator at a distance from the pivot of the latter, the actuator and the second link forming a toggle joint to operate the first link to raise said member away from said bearing; and a connection between the actuator and the block to insert the latter between said member and the fixed bearing.

12. A lifting device comprising a rotary member to be lifted; a fixed bearing having a raised portion; a sliding block; a lifting member connected with the rotary member and engaging the fixed bearing to lift the rotary member away from the fixed bearing, said lifting member having projections adapted to engage said raised portion at each side thereof to prevent rotation of the rotary member; an actuator to operate said lifting member and also to insert the sliding block between said bearing and said rotary member and in position on said bearing, said actuator having connections with said block and said lifting member to cause the latter to raise the rotary member from the sliding block when the latter is sta tionary and in position between the rotary member and the fixed bearing.

13. A lifting device comprising a member to be lifted; a link pivotally connected to said member and having a roll at its free end; a fixed bearing having a track for said roll, one portion of the track being at a greater distance from said pivot than another portion; a rotary actuator; a second link pivotally connected with the first link and also pivotally connected with said actuator; a sliding block; a link having a pin and slot connection with said sliding block and having pivoted connection with said actuator, all combined to insert said block in position on said bearing after said member has been. lifted, to lower said member onto said block, to lift said member from said block While the latter is stationary and to ing block between said bearing and said Withdraw said block from its position on member When the latter is lifted; and an acsaid fixed bearing. tuator to actuate both ofsaid means.

14:. A lifting device comprising a member RANDALL D. GARDNER. to be lifted; a fixed bearing; a sliding block; 1 lVitnesses: means to move the member to be lifted away ARTHUR l3. RANDALL, from said bearing; means to insert the slid- GEORGE A. ROOKWELL.

Copies of this patent may be obtained for five cents each, by addressing'the Commissioxier of Batencs,

Washington. D. C.