US1691807A - Safety device for automobile lifts - Google Patents

Description

Nov. 13, 1928. 1,691,807

E. E. HOLLISTER .SAFETY DEVICE FOR AUTOMOBILE LIFTS Filed Au 24, 1926 4 f Y'all, W mL Patented Nov. 13, 1928.

UNIED STA EDWARD E. HOLLISTER, OF QUINCY, ILLINOIS, ASSIGNOR TO HOLLISTER-WHITNEY COMPANY, OF QUINCY, ILLINOIS, A CORPORATION OF ILLINOIS.

SAFETY DEVICE FOR AUTOMOBILE LIFTS.'

Application filed August 24, 1926. Serial No. 131,263.

The present invention relates to improvements in lifts, and more especially to those of the class adapted to lift an automobile or the like above a floor to enable workmen to enter beneath it for the purpose of inspection, servicing or repair, and the primary'object is to provide a safety device which is movable automatically into operative position while the lift is being raised, and when the lift has reached its uppermost position will act to lock the lift against accidental descent, which, if permitted to occur, would en-' danger the workmen or render the automobile liable to damage. The safety device may be used .to especial advantage where fluid pressure, such as air, is employed for raising the lift. as the safety device will'prevent de-. scent of the lift due to leakage or other unintended escape of the air or actuating fluid.

Another object of the invention is to provide a safety device of this character with a latch or equivalent means for holding it in an inoperative position preliminary to the lowering of the lift, thereby preventing the safety device from obstructing or otherwise interfering with the restoration of the lift to its lowered position, the latch being'so arranged that it will automatically release the safety device when the lift is substantially fully lowered, thus insuring the placing of the safety deviete) condition to move automatically in operative position during the next succeeding ascent of the lift.

To these and other ends the invention consistsin certain improvements and combinations and arrangements of parts, all as will be hereinafter more fully "described, the features of novelty being pointed out particularly in the claims at the end of the specification.

In the accompanying drawing:

Figure 1 is a side elevation of a portion of an automobile lift using fluid pressure such as air for its actuation, the lift being shown equipped with asafety device embodying the present invention;

Figure 2 is a side elevation of the upper portion of the lift and the safety device as viewed from the right in Figure 1,"the safety device being shown in'position to prevent descent of the lift;

Figure 3 is a detail view on an enlarged scale of a portion of the safety device and the latch, the latter being shown in condition to hold the safety device in a position which will permit descent of the lift; and

Figure 4 is a detail perspective view of a portion of the safety device and the latch therefor.

Similar parts are designated by the same reference characters in the several views.

' Safety devices embodying the present invention are applicable generally to lifts and similar devices generally where it is desirable or necessary to insure the same against accidental or unintentional descent, although they are particularly applicable to automobile lifts and the like for the protection of workmen who may be beneath the lifted automobile engaged in the inspection, servicing or repair thereof, and who wouldbe liable to injury if the lift descended prematurely or accidentally. A safety device embodying the present invention is particularly advantageous when. used in conjunction with an automobile lift of the class shown and de scribed in my c'o-pending application, Serial No. 131,261, filed Aug. 24, 1926, where no pit is formed in the floor beneath the lift table.

The'preferred embodiment of the invention is shown in the accompanying drawing and will be hereinafter described in detail. It is to be understood that the invention is not restricted to the precise construction shown as equivalent constructions are contemplated. and such will be included within the scope of the claims.

In the present instance, 1 designates portions of the bolster members of a table which has rails thereon or is otherwise adapted to receive the automobile to be lifted, the table being constructed, for example, as shown in my co-pending application above referred to. In the present instance, the table is lifted by fluid pressure, as, for example, air, the lift having a plunger 2, the head 3 of which is secured to and supports the table, and this plunger reciprocates vertically in a cylinder which may be sunk in the floor of the garage shop or place where the lift is installed, the cylinder having a flange 4 at its upper end which rests on the surface of the floor and a stuffing box 5 through which the plunger operates. The

. flanges for the support of the strut.

the under side of the plunger head 3 so that they project downwardly therefrom, these flanges being spaced apart sufliciently to clear the stuflin box 5, but to come to rest-on the flange 4 of the cylinder when the lift is lowered, these'flanges thus acting as stops which limit the descent of the table, and the upward movement of the plunger incident'to the raising ,of the lift may be arrested at a predetermined point by stop means, such, for example, as that shown and described in myco-pending application, Serial No. 131,262 filed Aug. 24,1926. I

The safety device as shown in the'present instance comprises a strut 7 which is composed preferably of a length of channel iron of a length" approximately equal to the distance of the plunger head above the cylinder flange when the lift is fully raised. lhe strut is attached .to the plunger head so that it may swing either'into a position in sustantial parallelism with the axis of the plunger, thus enabling its lower end to rest on the cylinder flange lwhen the lift is fully raised, and its lower end may swing outwardly from the plunger to a position where the strut is approximately horizontal or at a right angle to the axis of the plunger to enable the lift to be I lowered and the strut accommodated in the relatively shallow space between the table of the lift and the floor when the lift is lowered. As shown,- the strut is pivotally suspended at its upper end by a pivot rod 8 which may extend through the flanges of the channel iron forming the strut, and this pivot rod may extend through the stop flanges 6 secured to the upper side of the head, thus utilizing these Brace rods 9 are preferably secured to the opposite sides of the strut and extend upwardly and divergently and connect with the pivot rod 8 at points immediately within the flanges 6, these rods acting to reinforce the strut and prevent tipping thereof under strains that may be imposed upon the strut while the lat ter is in its operative position with its lower end resting on the cylinder flange and sustaining the weight of the lift. When the strut is in this position, its upper end is prefe'rably immediately below a portion of the plunger head so that the upper end of the strut will bear solidly against the plunger head if the rod 8 becomes bent under the weightimposed upon it. The weight imposed on the strut will retain it in its. upright operative pogition with its foot resting on the cylinder an e.

v 11% order to lower the lift, the lower end of the strut must be swung outwardly or away from the plunger toward or into substantially the dotted line position shown in Figure 1. When the strut is swung into this position, it will not obstruct descent of the lift. However, in order to hold the strut in this inoperative position and thus preventits lower end from being blocked by the floor during descent of the lift, a latch is provided and this latch is preferably so constructed that it will automatically hold the strut in its elevated or inoperative position when swung manually into that position. The latch comprises preferably a pin 10 which is carried by a pair of links '11, these links being pivotally connected by a pin 12 to a bracket 13, the latter being fixed to the plunger head or to one of the bolster members 1 secured thereto. The pin 12 about which the pin 10 swings as a center is located above the pivot pin 8 about which the strut swings so that the pin 10 will be movable longitudinally along the under side of the strut while the latter is being swung into operative or inoperative position. The pin 10 is guided to move longi: tudinally in close relation with the under side of the strut by a pair of guides 14 which may be composed of pieces of angle iron which are bolted to the under side of the strut in spaced relation thereto, and two of the flanges of theseangleirons may be turned downwardl and spaced apart to provide a slot in whic a dog 15 operates. The dog is pivoted to these guides by a pivot pin 16 and the weight of the'dog is so distributed that its, end ,17

side of the strut by the overbalance of the tail of the dog, when the strut is swung into an approximately horizontal position, as

or toward the free end of the strut 7 as the latter is swung from the operative or full line )osition toward the dotted line position in igure 1, the pin 10 passing idly the end 17 of the dog until the pin is in a position to abut against the end of the dog, the dog automatically latching behind the pin when the strut reaches a predetermined raised position and thus acting automatically to prevent reverse movement of the pin 10 so that the strut will be held in its raised position.- If it should be desirable to release and swing downwardly the strut 7 after it has been raised, such may be accomplished by pushing upwardly the tail end 18 of the dog, this movement of the dog removing its opposite end 17 from the pathof the pin 10 and thus allowing the strut to be lowered. However, the dog ordinarily locks the strut in its raised position prepa at y to the descent of the lift will be swung upwardly against the under and it retains the strut in its laterally extended position until the lift has been sub stantially fully lowered. The final part of the lowering movement of the lift, however,

will bring the tail end. 18 of the dog into con-- tact with the flange 4 olrthe cylinder, and as the lift continues to descend, the dog will be rocked on its pivot in a direction to withdraw its end 17 from the path of the pin 10,,there-by releasing the strut and permitting it'to drop onto the floor as the lift reaches or nearly reaches the limit of its descent, as determined by the stop flanges 6. The strut is thus enabled to be accommodated in a flatwise position between the bottom of the table of the lift and the floor. The releasing of the strut automatically as the lift approaches the lower limit of its movement sets the strut in condition toautomatically swing into operative position to lock or hold the lift in its raised position, upon the next succeeding lifting operation, thus insuring certainty in the operation of the safety device and relieving the operator of the necessity of giving his attention thereto.

During the lifting operation, the unla-tched strut will rest with its free end on the floor while-its upper end will move vertically upward by the rise of the pivot pin 8 attached to the plunger head. As the ascent of the lift takes place, the strut will swing gradually from-a substantially horizontal to a vertical position, and as the lift reaches the upper limit of its movement, the lower end of the strut will ride over the cylinder flange 4 and. come against the stuffing box 5.which positions the lower end of'the strut to engage thetop of the c *linder flange 4. The upward movement 0 thevplunger is then arrested and the lower end of the strut will come to rest on top of the cylinder flange. Thus, the strut automatically moves into locking position incident to the ascent of the lift, and leakage of fluid pressure such as air, and which, if it occurred, would remove the support for the plunger, will not cause premature or unintentional descent of the lift as the strut will positively lock the lift in raised position. Wlin it is desired to lower thelift it is only necessary to admit fluid pressure to the cylinder to force the plunger upwardly sufli-- c'iently to relieve the load on the lower end of the strut, the strut being then swung outwardly and to the approximately horizontal position shown by the dotted lines in Figure 1 until the dog 15 locks it in such position.

' The fluid pressure may then be released from the cylinder, thus allowing the lift to descend, and when the lift approaches the limit of its descent, the tail of thedog striking the cylin der flange retracts the dog and thus automatically releases the strut and puts it in a condition to act automatically as, a support for the lift during the next succeeding ascent thereof. 1

I claim as my invention 1. In a vertically-movable lift of the class described, a safety device movableautomativ(-ally during ascent of the lift, into a posi-.

tion to prevent descent of the lift and means held in released condition while the lift is in lowered position, for holding said device 7 in inoperative position.

2. In a vertically-movable lift of the class described, a strut carried thereby and movably automatically in, upright position, during ascent of the lift, to retain the latter 1n raised position, and a latch for holding the, strut in inoperative position, said latch having means for releasing it automatically during descent of the lift.

3. In a vertically-movable lift of the class described, a strut pivotally connected thereto and movable automatically into an upright position, during ascent of the lift, to retain it in raised position and capable of being swung laterally to permit descent of the lift, and means releasable automatically during descent of the lift, for holding the strut in said lateral position.

4. In a vertically-movable lift of the class described, a member pivotally connected thereto to swing into a position to support the lift in raised position and to swing laterally into a position to permit descent of the lift, and means releasable automatically durmovable into a position to hold the lift in raised position and also movable into an inoperative position to permit descent ,of the, lift, and a latch operative automatically to retain said member in its inoperative position and releasable automatically during descent of the lift.

6. In a vertically-movable lift of the class described, a strut pivotally connected at one end to the lift whereby it will be automatically swung into an upright position, during ascent of the lift, to hold the lift in raised position, the'strut being capable of swinging laterally into a position which will permit descent of the lift, and a latch operative automatically to engage and hold the strut in said lateral position and releasable automatically during descent of the lift.

the class 7 In a vertically-movable lift-of the class 4 lift, to hold the latter in raised position and a part during the final portion of the decapable of being swung into inoperative posisuending movement of the lift, to trip said tion to permit descent of the lift, and a latch dog and thereby release said member. embodying a dog operative automatically In testimony whereof I have hereunto set While said member is being swung into inopmy hand. erative position; to hold it in such position,

said dog having a portion arranged to engage EDWARD HOLLISTER.

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