US2151338A

US2151338A - Lifting and lowering mechanism

Info

Publication number: US2151338A
Application number: US123158A
Authority: US
Inventors: Harold W Shonnard
Original assignee: Individual
Current assignee: Individual
Priority date: 1937-01-30
Filing date: 1937-01-30
Publication date: 1939-03-21
Anticipated expiration: 1956-03-21

Description

March 21, 1939. H. w. sHoNNARD LIFTING AND LOWERING MECHANISM Filed Jan. 30, 1937 4Sheet's-Sheet l in H v//l//A I l NVENTOR afo/a M4 Shan/mrd nj l BY E. Mgg@ -March 2l, 1939. H. w. sHoNNARD LIFTING AND LOWERING MECHANISM Filed Jan. 30, 1957 4 Sheets-Sheet 2 /v/ ATTORNEYS March 21, A1939.

H. W. SHONNARD LIFTING AND LOWERING MECHANISM Filed Jan. 30, 1937.

4 Sheets-Sheet 3 vlNvx-:NTOR

Haro/a W. 5ba/mara MKM ATTORNEY` Mmh 21, 1939. -H. w. SHONNARD 2,151,338

LIFTING ANDVLOWERING MECHANISM Filed Jan. 50, l937 4 Sheets-Sheet 4 Fig JilNVENTOR ATTO RNEY5 Patented Mar. 21, 1939 UNITED STATES `lPVA'rEN'r, oFFlcE 2,151,333 i LrF'nNG AND Lownamo, MECHANISM Harold W. anonima, Monteur, N. J.

Applicaties January so, 1937, serial No. 123,158

' 12 claims. (ci. asi- 172) I'his invention relates to improvements in lifting and lowering mechanism.

Its object is. to provide a simple, compact, efficient and inexpensive apparatus for raising objects from one level to anotherand for retarding the descent of objects under variable .speed control.

Another object is to lprovide an arrangement for connecting a driving shaft with a hoisting m element, such asy a cable drum, through a friction clutch for moving such element in one direction and to provide for use of the same clutch as a variable brake for controlling the rate of ,movement of the element in the opposite direction.

15 This invention'is applicable to tail gate elevators for vehicles, but is in no sense limited to that specific use.

y 2 A further object is to provide a' single control lever for both lifting and lowering. I also pro'- vide an interlocking arrangement, which may be associated with the control lever to prevent release of the clutch for permitting and retarding 39 the descent of a load while the driving force isA connected with the hoisting gear and to insure the engagement of the clutch before the driving force can be connected with the hoisting gear.

A still further object is to provide for changing 35 the ratio of driving gears while in mesh and in motion.

These and other objects of the invention will appear in the'followlng specification in which certain embodiments of the invention will be 40 shown and described and their novel features set forth in appended claims. l

Referring to the drawings,

Fig. 1 is a vsectional end elevation of a preferred embodiment of my invention, the section Fig. 2 is a side elevation partly in section of the parts shown in Fig. 1;

Fig. 3 is an end view of an over-running clutch arrangement shown in Fig. 2;

50 Fig. 4. is a side view of an electric switch and its control lever which are shown in Fig. 2;

Fig. 5 is an enlarged end elevation partly in section of a holding mechanismvwhich is shown in Fig. 2, the section in this figure being taken u on the line 5 5 of Fig. 2; y

Several applications of the mechanism will be illustrated and described tor Fig. 6 isa sectional elevation of another form of holding' mechanism;

' Fig. '1 is a side elevation of a truck provided with a tail gate hoist and my novel actuating and controlling device; 5

Fig. 8 is a plan view of a part of the truck shown in Fig. 7, and ofsome of the devices which are mounted thereon;

Fig. 9 is a diagram of some ofthe parts of the raising and lowering mechanism and of the tail 10 gate hoist and interconnecting electric circuits;

Fig. 10 is a side elevation with parts in section, of a modified arrangement ofthe control device. This gure shows aI transmission shaft of' a vehicle motor used to drive the hoisting gearing;

Fig. 11 is an end elevation partly in section of the arrangement shown in Fig. 10;

Fig. 12 is an' illustration of another type of apparatus with which this invention may be used, in this particular case showing my raising and lowering mechanism applied to a movable crane;

Fig. 13 shows a similar mechanism applied to an overhead crane; and

Fig. 14 shows the, mechanism used as a jack for a vehicle, such for example, as an automobile trailer.

20 designates a casing having removable ends 2| which form bearings for a load shaft 22. In Fig. 1, a cable drum 23 is shown keyed to one end of this shaft. The. shaft projects from both of the sides 2l, so that drum or other transmission element may be mounted on either of its ends. The ends of the shaft may be constructed to receive a hand crank 2A. Intermediate its ends, the shaft 22 has a splined portion 25, on which 35 is non-rotatively, but slidably mounted a friction disk 26.

30 is a hub freely mounted on the shaft 22 and carrying a circular plate 3|. 32 is a packing between one end of the hub and the shaft 22. 40 The plate 3| has an inner surface which cooperates with the friction disk 26. 33 is a rim secured to the plate 3i, provided with external gear teeth I4. Another plate 35 is secured to the other side of the rim 33. The plates 3l, 35 and the rim 33 form 45 'an oil-tight chamber within which the clutch mechanism which I am about to describe, is enclosed. f

A series of radially disposed levers 40, one of which is shown, are pivotally supported at 4i on 50 the plate 35. l2 is a pressure plate supported on the outer ends of the levers 40 and normally pressed by springs 43 against the friction disk 2i. 44 is a collar freely mounted on the shaft 22. l The plate I5 is rotatably supported on the outer 65 surface of this collar. 45 is a flange projecting from the inner end of the collar 44 and bearing against .the inner ends of the levers 40. The plate 35 and the collar 44 are provided with oil sealing packings 36 and 46, respectively.

41 is another collar, freely supported on. shaft 22 and having an outwardly projecting ange 48. 49 is an anti-friction thrust bearing interposed between the collars 44 and 41,

50 is a shifter which is forked, as shown in Flg. 2, to clear the collar 41, but to bear upon its flange 48. 'I'his shifter is aiiixed to a shaft 5| which is rotatable in

stationary bearings

52, 53 in the casing. Another forked member 54 is affixed to shaft 5|, spaced from the shifter 50, but within the casing. Between the ends of this forked member 54 is an internally threaded member 55 having pin and slot connections with the ends of member 54. This member 55 is'mounted upon a threaded portion of a control shaft 56 which is parallel with shaft 22 outside of the gear teeth 34, but within the casing 26. This control shaft is supported in bearings 51in the casing and projects through both of its sides 2| to receive a control handle 56B.

58 is another lever affixed to shaft 5| outside of the casing.. This is arranged to open a normally closed electric switch 59, a side view of which is shown in Fig. 4.

The shafts 5| and 56 may be located in the positions indicated in dotted lines and designated by 5|A and 56A in Fig. 2, if it is desired to place the control shaft below the load shaft 22.

66 is ahollow shaft in bearings 6| in the casing 20. On it is a worm 62 in engagement with the gear 34. 63 is a gear and 64 a member of a spiral lar pockets 14 in which are locking balls or rollers 15. These cause the gear to be driven by the disk when the latter is rotated in the direction of the arrow, but permit the gear to rotate freely on the 0 disk in the same direction when the gear is driven at a higher rate'of speed by another mechanism.

g 16 is another gear affixed to the countershaft 16, in mesh with a gear 11 afhxed to the shaft 18 v of an electric motor 19. The motor shaft 18 exutends into the hollow worm shaft 60. Slidably but non-rotatively mounted on it is another spiral jawed clutch member 65 which maybe moved into and out of engagement with clutch member 8| is a disk afxed to worm shaft 66 on which are t pivoted a series of pawls 82. These move outwardly under the influence of centrifugal force when the disk 8| is rotated, to clear the teeth vof the ratchet wheel, but when at rest at least onel of the pawls engages the teeth `of the ratchet wheeland holds the disk and Worm shaft together,

and consequentlyholds the plate 3| against rei verse movement. v

ii. l

Another arrangement for accomplishing this result is shownA in Fig. 6. In this case a stationary disk 86A having a cylindric outer surface is aixed to the casing and 'is surroundedA by a disk 6|A on the worm shaft. 82A designates locking balls or rollers in angular pockets 83. These permit disk 8|A to rotate in the direction indicated by the arrow, but become jammed between the walls of pockets 63 and the outer surface of disk 66A to prevent rotation in thel opposite direction. I prefer to make the pockets'f83 of sufficient depth to permit the balls or rollers to move out entirely clear of disk 66A under the action of centrifugal force when the disk 8|A is in motion.

Before describing further modifications and specific applications of the invention I will describe the 'operation of the mechanisms shown in Figs. l6.

When at rest the parts will bein the relative position in which they are shown, with theshaft 22 and side plate 3| held by one of the pawls 62y l against rotation in one direction and the friction clutch engaged by the pressure of the friction disk 26 against plate 3|. A load connected by a cable with the cable drum 23 will be held stationary. If it is desired to raise such a load the yoperator rotates the control shaft 56'in a direction to move member 55 to the right, as viewed in Figs. 1 and 4. This first eects a driving connection between the friction disk 26 and the plate 3 I, and continued movement of member 55 in the same direction removes lever 58 from the switch 59 and allows the latter to'close the motor circuit.

The motor will rotate the worm 62 through

gears

11, 16 and 12, 63, the gear 34 and clutch plate 3|. The friction disk 26 is held in engagement with plate 3| by the pressure plate 42 and moves with it to rotate the load shaft 22 andlift the load. This will continue until the motor circuit is opened when the parts will be held again to prevent descent of the load.

The gear ratio between the motor and the Worm may be changed during this hoisting operation by moving lever 66 to move clutch member 65 into engagement with clutch member 64. Then worm shaft 60 will be connected to run in unison with motor shaft 16. The gear 12 will overrun the disk 13 whichgcontinues to rotate at the slower speed of the countershaft 10. This operation may be reversed at will. y

When it is desired to lower the load, the operator turns control shaft 56 to move member 55 to the left, thus 'forcing shifter 50 against the flange 48 of collar 41 and'moving collars 41 and 44 and the inner ends of levers 46 to the right (Fig. `1 position)' and releasing the pressure of presser plate 42 from the friction clutch. This release is gradual and can be nicely adjusted to: let the clutch slip as rapidly or as slowly as desired to contro-l the rate of the descent ofthe load. An interlocking condition exists in that at the time the clutch is released to lower the load, the motor shaft 68 and the parts 'directly connected with it are held againstreverse rotation and the switch 59 cannot be closed when the member 55 is in position to release the friction clutch. 4

Referring now to Figs. 7 and 8, I will describek the application of this invention for actuating a tail gate hoist for vehicles. In these figures, 90 designates a truck having a floor 9|. Vertical guides 92 are affixed to opposite sides of the rear end of the truck and braced to the truck body by cables 93. Each of these guides has two channels.

Posts 94 slide in one of these channels and'coun- 75 tov these posts with their upward movement limlted by stop pins 91. Chains 93 connect the outer end of these links lwith the upper end of counter-- weights. Chains 99 connect the lower ends of the counterweights with the cable drum 23A.

A load platform isI pivoted to the posts 94 in such a manner that it will assume a tilted position when'theposts 94 rest on the ground. |0| are chains connecting the loading platform with the links 96. The platform is heavier than the counter-weights so that it will pull the links away l from their stop pms s1.

The cable drums 23A are. connected with the power shaft 22 by cross-shafts 22A and exible couplings. In Figs. 7 and 8 the change-gear arrangement interposed between the motor and casing 20 is omitted. 1 In this arrangement the ends of the contro shaft 56 are extended to near the hoisting platform convenient `to the operator. After a load has been placed on the platform |00 the latter can be raised, rst to a horizontal position and then tothe level of the truck floor 9|, in the manner previously described. The rate ofrise of the platform may be retarded by la manipulation of the control shaft 56/to permit the friction clutch to slip.

ALoads of delicate merchandise may be lowered on the platform |00 as its rate of descentmay be controlled to a nicety by the operator. In case of loss of power, the hand crank 24 may be used to lift posts 94 off the ground.

l If desired to provide an automatic stop device for the platform, a self-closing limit switch |02 maybe placed in the path of movement of the counterweight 95, or two such switches connected in 'series may be placed one under each counterweight. A diagram of such connections as may be used is shown in Fig. 9. i

When the parts are in the positions shown in Fig. 9, the motor switch'59 is open and the limit switch |02 closed. One side of a. battery |03 is grounded to the frame of the vehicle at A. The

other side of the battery is connected to the limit switch by a conductor |04. |05 is a. conductor from the limit switch to themotor switch 59.- 4|06 is a conductor from the motor switch to lthe motor 19, the. other side of which is grounded to the vehicle frame at B. Now, when motor swltch-59 is closed by the rotation of control shaft 56, the motor will be energized to pull down the counterweight 95 and lift the load. This loperation will continue until the counterweight 95 strikes the limit switch |02 to open it and stop the motor. The limit switch is positioned to be opened when the load lplatform reaches a desired predetermined level,-such as thelevel of the truck floor 9|. i'

Th motor 19 cannot be energized again until the limit switch is closed andthe latter cannot be closed until the load platform is lowered, at

, least enough to raise the counterweight 95 from end of a drive shaft IIB. The drive shaft I|6 extends into the worm shaft 60A with a loose nt. In this case the worm shaft is provided with one or more longitudinal key-ways, into one of which a key ||1 on the drive shaft ilts.v

|20 is a bifurcated shift lever which .engages a kroove ||3.in the clutch member H3. It is afxed to a shaft |2| rotatable in 4bearings |22 in casing 20. |23 is a lever affixed to shaft |2|. This is connected by a link |24 with a lever |25 affixed to a. shaft |26'rotatable in the casing. |21 is an arm of another member afxed to shaft |26 within the casing and having an anti-friction roller |28 at its upper end. |29'is a cam arm integral with' the arm |21. i

|30 is the driving member of an intermittent gear, aillxed to the load shaft 22. This intermittently actuates a driven disk |3| pivoted at |32 to the casing and bearing a pin |33 which as it Imoves engages the vcam arm |29. 'I'his disconnects clutch members ||3, ||5. It is to `be noted that the movement of pin |33 is comparatively fast at the time it moves cam lever |29.

. In this case the control shaft 56C has a threaded portion 4|34 in an internally threaded stationary member |35 so that a longitudinal movement is imparted to the shaft when it is rotated and to the member 55A which is affixed to it. A cam drum |36 is also affixed to control shaft 56C against which the roller |28 is pressed by the spring ||4. This drum has a depressed w portion which permits the roller |28 to move toward the control shaft to the position in which it is shown in Fig. 10. This occurs when the control shaft is rotated in the direction to effect vhoisting and 'causes the clutch members ||3, H5 to engage each other, and connect shaft ||0 operatively with worm 62A.

Rotation of load shaft 22 will continue through j a predetermined number of revolutions when the intermittent gear members |30, |3| will move pin |33 under camarm |29 to raise it and disconnect clutch members ||3, ||5, thus stopping the hoisting movement automatically.

The parts are now so held that no further hoisting connections can be made until the cable drum and its shaft.22 have been reversed to lower a. load or the load platform. When the drive shaft is thus disconnected, control shaft 56C may be rotated in the direction to permit the friction clutch to slip to effect lowering. Such rotation of the Icontrol shaft brings the larger part of cam drum |35 under -roller |28 and holds it out to prevent reconnection of clutch members ||3, ||5 during the operation of lowering.

'I'he cam drum |36 is so proportioned that the control shaft can be rotated to cause parts of the friction clutch to become rmly engaged to prevent further lowering of the load before roller |23v reaches the depression in the c am drum.

In Fig. 14 the parts of the mechanism are somewhat modiiled to adapt them to be used` as a jack for the front end of a vehicle trailer |60. Instead On the frame of of a solid power shaft 22, suchvas shown in the other figures, a hollow internally threaded shaft Several modifications and adaptations of this invention have been illustrated and described in order to show that many changes in the construction and arrangement of the parts may be made within its spirit and scope, and I intend no limitations -other than those imposed by the appended claims.

What I claim is:

1. A shaft, means for connecting a load therewith, a friction member connected to rotate with the shaft, a driving member freely supported on the shaft, associated with the friction member, means for rotating the driving member in one direction only, and means for operatively connecting the friction member with the driving member to rotate the shaft in one direction and for gradually releasing the connection between said members to permit the shaft to be rotated in the opposite direction under the influence of a load thereon and to control the rate of said movements in both directions.

2. A shaft, means for connecting a load therewith, a friction member connected to rotate with the shaft, a driving member freely supported on the shaft, associated with the friction member, means for rotatingfthe driving member in one direction, means for holding the driving member against rotation in the opposite direction, and means for operatively connecting the friction member with the driving member to rotate the shaft in one direction and to prevent relative rotation between said members and for gradually releasing said connection to permit the-shaft to be rotated at a desired rate under the influence of a load thereon, in the direction opposite to that of the driving member.

3. A load shaft,'means for connecting a load therewith, a friction member connected to rotate with the load shaft, a driving member freely supported on the load shaft associated with the friction member, a power shaft and gearing between the power shaft and the driving member whereby the driving member may be rotated in one direction, means associated with the power shaft for holding the driving member against rotation in ,the opposite direction, and means for operatively connecting the friction member with the driving member to rotate the load shaft in one direction and to prevent relative `rotation between said members and for gradually releasing said connection to permit .the load shaft to be rotatedA at a desired rate under the influence of a load thereon, in the direction opposite to that of.y the driving member.

4. A load shaft. means for connecting a load therewith, a friction member connected to rotate with the load shaft, a driving member freely supported on the load shaft .associated with the friction member, a power shaft and gearing between the power shaft and the driving member whereby the driving member may-be rotated in one direction, means actuated by the rotation `of the load shaft in the load raising direction,'for automatically stopping the rotation of the power shaft, means associated with the power shaftv for holding the driving member against rotation in the opposite direction, and means for operatively connecting the friction .member with the 'driv-v ing member to rotate the' load shaft in one direction and to prevent relative rotation between said members and for gradually releasing said connection to permit the load shaft to be rotated at a desired rate under the influence of a load thereon, in the direction opposite to that of ing member.

5. A load shaft, means for connecting a load therewith, a friction member connected to rotate with said load shaft, a driving member freely supported on the load shaft having a friction surface, an oil-tight casing surrounding the friction member, means within the casing for pressing the friction member into engagement wtih the friction surface of the driving member, a power shaft geared to drive -said driving member, and an adjusting device outside of the casing for controlling the pressure between said members.

6. A load shaft, means for connecting a load therewith, a friction member connected to rotate the drivlwith said load shaft, a driving member in the `form of an oil-tight casing surrounding the friction member, freely supported on the load shaft, having an internal friction surface on one side of the friction member and supporting a presser plate on the other side of the friction member, a power shaft geared to driving said casing, and a control device outside of said casing for adjusting the pressure between said members and the presser plate.

7. A load shaft, means for connecting a load therewith, a friction member connected to rotate with said load shaft, a driving member freely supported on the load shaft having a friction surface, an oil-tight casing surrounding the friction member, means within the casing for pressing the friction member into `engagement with the friction of the friction member and supporting a presser plate on the other side of the friction member, a power shaft rotatable in one direction, geared to drive said casing, means for holding the power Shaft against rotation in the opposite direction, f'

and a control device outside of said casing for adjusting the pressure between said members and the presser plate. A'

9. An outer casing, a load shaft supported thereby, means for connecting a load therewith, a friction member on apart of said load shaft within the outer casing connected to rotate with the load shaft, a driving .member freely supported on the load shaft, having a friction surface. an inner oil-tight casing surrounding the friction member, a gear outside of said inner casing, va. power shaft, a gear thereon within the outer casing in mesh with the gear outside -of the inner casing, arranged to drive the driving member in one direction, means for holding the power shaft against rotation in the opposite direction-and a control device outside of said inner casing for adjusting the pressure between said members. v A 10. An outer casini. a load shaft supported Y v 2,151,838 thereby, means for connecting a load therewith, a

frictionmem-ber on a part of said load-shaft within the outer casing connected to rotate with the load shaft, a driving 'member in the form of an the friction member, a gear outside of said inner in one direction, means for lholding the power casing, a power yshafta gear thereon within the L outer casing in .mesh with vthe gear' outside of the inner casing.` arranged to drive ithe inner casing shaft against rotation in .the opposite direction, a control shaft in the outer 'casing-parallel -with the load shaft; extending through said outer casing, and a control member on the control shaft for adjusting the pressure between said members.

11. An outer casing, a'. loadrshaft extending through and beyond both 4sides thereof, a friction member on an intermediate part of said load shaft connected to rotate therewith, adriving member in the form of an inner casing-surrounding the friction member, freely supported on the load shaft, having an internal friction surface on one side of the friction member, supporting a presser plate on the other side of the friction member vand supporting springs acting on the presser plate to force the friction memberinto driving'engagementl lwith said friction surface, gear teeth lon the outside of said inner casing, a

power shaft, a gear thereon in mesh with the gear| teeth on the inner casing in the lower part ofthe outer casing, .arranged to drive the inner casing in one direction', means for holding the power shaft against rotation'in the opposite direction, and a control device outside of said inner casing for adjustably counteracting the effect of said 4springs.

12. An outer casing, a load shaft extending through and beyond both sides thereof, a friction member on an intermediate part of said load shaft connected torotate therewith, a driving member in the form of an inner casing surrounding the friction-member, freely supported on the 'load shaft, having an internal friction surface .on one side of the friction member, supporting a ,presser plate on the other. side of the friction member andsupportingl springs acting on the `presserplate to force the friction memberA into drivingk engagement with said friction surface,

, gearteeth on the outside of said inner casing, a power shaft, a gear thereon in mesh with the gear teeth on the inner casing in the lower part acted by rotation of the, control shaft.

HAROLD W. SHONNARD.