US1728460A - Hoist - Google Patents

Description

Sept. 17, 1929.

C. J. WEBER ET AL HOIST Filed June 29, 1926 2 Sheets-Sheet indenara:

Patented Sept. 17,- 1929 UNITED STATES PATENT OFFICE CLARENCE J. AND ROY A- SEE K, OF CHICAGO, ILLINOIS, ASBIGNOBS TO NA- 'IIONLL BBICK'COHPANY, OF CHICAGO, ILLINOIS, A. CORPORATION OI ILLINOIS HOIST Application am! June 29, 19211. Serial No. 119,312.

Our invention pertains in general .to trucks or trailers and more particularly to hoisting mechanism therefor. we contemplate the provision of improved mechanism for tiltin a truck or trailer body for the purpose of discharging the contents therefrom with facility.

In hydraulic hoists for liftin the'front end of a body of a truck or trai or, it is old to permit the hoist cylinder to move about its pivotal mounting as far as the body of the truck will permit. That is to say, as the plunger in the cylinder is elevated, the end of the body is also raised about its pivot,

pulling towards it the upper end of the cylinder. This movement of the cylinder has been usually taken care of by providing a pivotal mounting for the lower end thereof. The primary disadvantage of this construction was that it permitted the cylinder to freely sway to and fro.

This swaying action is undesirable for two reasons. In the first lace, it increases to a considerable extent t e wear of the parts,

particularly the bearings associated, with the pivotal mounting for the c linder. In the second place, it causes the lifting cables to flex much more than is necessary and thus decreases the longevity of these cables. Also it is to be understood that this swaying action is deleterious to the 'efliciency of the hoist itself in raising the end of the truck body.

Now we propose to provide a hoist of the character mentioned above wherein the movement of the cylinder is restricted. In fact, We contemplate ,the provision of mechanism for actually resisting this lateral movement of the hoist cylinder.

We have disclosed herein a construction with which we have attained highly desirable results. It comprises, in general, essentially a resilient mounting for the hoist cylinder. More specifically, it consists of a spring device for resisting movement of the hoist cylinder about its pivot. The degree of movement of the cylinder about its p vot depends upon the amount of the load 1mpos'ed thereon. In fact the movement 1s Specifically proportional to the weight of the load in the truck body.

In accordance with the general features of our invention there is provided a hoist cylinder having a: pivotal mounting and resilient means associated with the mountmg comprising a plurality of leaf springs adapted to at all times urge the cylinder into a true vertical position with respect to the chassis of the truck.

Also, we have from experience found that the cup leather associated with the hoist piston tends to wear out much faster than is usual, due to the fact that it is flexed considerably. We have remedied this condition by positioning the cup leather in a substantially central position with respect to the piston, and by providing the piston with piston rings on each side of the cup leather. These piston rings serve to confine the cup leather ,and also to relieve the cup leather of considerable wear by preventing it from being flexed to any considerable extent.

In accordance with other features ofour invention, we have provided novel detachable connections between'the hoist cylinder and the source of hydraulic power, which connections permit of the cylinder being disconnected with facility from the hydraulic power unit. 4

In accordance with still other features of our invention, we provide in the connections between the hoist and the pump a three way valve construction for controlling the operation of the hoist. This valve permits of an oscillatory movement being imparted to the hoist. plunger to cause the same to jar the trailer body and thus cause allof the contents thereof to be quickly discharged. Then, too, thevalve may be actuated to disconnect the. pump from the hoist cylinder and to thus cause the plunger to be maintained in a 'ven stationary osition or to cause all 0 the fluid to be ischarged into the tank to lower the hoist plunger depending upon the position of the yalve control member.

Other objects and advantages of our 1nvention will more fully appear from the following detailed descriptlon taken in connectibn with the accompanging drawings which illustrate one embo iment thereof and in which,

Fig. 1 is a side elevation of a truck and trailer having associated therewith .a hoisting device embodying the features of our invention;

Fig. 2 is an enlarged view of the hoist cylinder and its pivotal mounting;

' Fig. 3 is a sectional view taken ,on the 'line 33 of Fig. 2 looking in the direction indicated by the arrows;

Fig. 4 is a sectional view of our novel hoist piston construction; and

' Fig. 5 is an enlarged sectional view of the three-way control valve associated with the pumping mechanism and oil tank.

Referring now to the drawings in detail, in which like reference numerals designate similar parts throughout the several views, 10 denotes generally a tractor (Fig. 1) which may be of any conventional construction. The tractor 10 is provided with the usual turn table 11 to which one end of a trailer 12 is connected. The tractor 10 and the trailer 12 comprise a truck, such as is well known in the automotive art. The trailer 12 is equipped with the customary body 13 having one end pivotally attached at 14 to the rear of the trailer 12. The front end of the body 13 is adapted to be raisedjto a position such as that illustrated by dotted lines in Fig. 1.

The body 13 is adapted tonormally rest upon the frame 15 of the trailer 12. The rear end of the frame 15 is provided with a pair of wheels 16 and a pair of springs I 17. The front end of the frame 15 is adapted to rest upon the turn table 11 associated with the chassis 18 of the tractor 10. Normally, the front end of the -frame 15 will be connected to the said turn table 11.

The frame 18 of the tractor 10 carries a pair of gas'tanks 19 and 20 which supply thefuel to the power unit of the tractor 10. These gasoline tanks 19 and 20 are positioned immediately behind the drivers station 21.

Mounted upon the front end of the trailer frame 15 is a hoisting device designated generally by the reference character 25. This device is adapted'to'be utilized to raise the body 13 about its pivot to a posit-ion such as that illustrated by dotted lines in Fig. 1. The device 25 includes a vertical cylinder 26 4 and a reciprocable plunger 27 mounted within the cylinder 26. The plunger 27 is preferably tubular in construction and has associated with its lower end a piston 28.

The piston 28 (Fig. 4) comprises a pair of annular members 29 and 30 separated by a cup leather 31. The annular member 29 is equipped with a reduced portion 32 which telescopes the lower end of the tubular plunger 27. The reduced portion 32 may be fastened to the plunger 27 in any desirable, manner. The annular member 29 is also provided with an annular stud 33 which extends through an aperture 34 in the center of the cup leather 31 and through an aperture 35 int e center of the annular member 30. The annular member 30 is prefer'ablyfequipped with an annular recess 36 in which a nut 37 is threaded upon the exposed end of the stud 33. This nut 37 serves to draw the members 29 and 30 together andserves to fasten the members and cup leather rigidly together. The an- 'nular member 30 is provided with a reduced portion 38 between the periphery of which and the inner wall of the cylinder I 26 is located the annular'rim 39 of the cup leather 31. In other words, the annular member 30 in reality telescopes the cup leather 31 and thus tends to prevent undue flexing of the cup leather. The annular member 29 is provided with a piston ring 40 and the annular member 30 is provided with a piston ring 41.

The piston rings 40 and 41 engage the inner periphery of the cylinder 26 and serve to relieve the cup leather 31 of some of the strains and stresses imposed thereon when the plunger 27 ,is actuated. Since the cup leather 31 is confined intermediate the telescoping annular member 30 and the inner wall 'of the cylinder 26 it cannot flex as freely as in prior piston constructions. This arrangement increases the longevity of the cup leatherand insures a reliable service on the part of the piston 28. Heretofore, the cup leather was caused to be flexed considerably upon' the reversal of the direction of movement of the plunger in the cylinder. In our construction the cup leather 31.cannot thus flex upon the reversal of the movement of the plunger due to its being confined intermediate the two members 29 and 30.

The upperend of the plunger 27 has fastened thereto a cross arm construction 45 which carries a pair of revolvable pulleys 46. Each pulley 46 is pivotally attached to an arm 47 pivotally bolted to the cross arm construction 45.

Referring now to Fig. 3, the upper end of the cylinder 26 is preferably threaded and provided with a cap 50 threaded thereon. The cap 50 has a plurality of notches 51 preferably four in number for enabling the sameto be turned with facility. The plunger 27 extends through an aperture 52 in the cap 51. The aperture 52 is preferably countersunk as indicated at 53, in order to accommodate a gland member 54 threaded into the upper part ofthe can 50. The gland member 54 is provided with a central aperture 55 through which the plunger 27 extends.

The lower part of the cylinder 26 is tightly fitted in a pivotally mounted member 56. This member 56 is provided with a pair of diametrically opposed extensions 57 and 58 journaled in bearing brackets 59 and 60. Thus it will be seen that the lower end of tlie plunger cylinder 26 is pivotally mounte cured to portions 62 and 63 of a base plate 64 by means of bolts 65. The portions 62 and63 are elevated from the plane of the base plate 64. The base plate 64 is provided with a pair of flanges 66 and 67 bolted to the channel irons 68 and 69 of the frame 15. The base plate 64 is also equipped with a pair of raised portions 71 and 72, upon each of which portions is supported a spring construction designated encrally by therefer ence character 70. Since both of the spring constructions are identical, .it is believed the description of one will suffice for both.

Each spring construction comprises a plurality of leaf springs 74 which vary in length. The springs 74 are held together by means of the usual clip 75. The longest, leaf spring 74 abuts the outer wall of the cylinder 26, as indicated at 76. The lower ends of the leaf springs 74 abut the top of the raised portion associated therewith. The springs are bolted to a lateral extension 78 projecting upwardly from the base plate 64. A

clamping plate 79 and a plurality of bolts, and nuts 80 are preferabl employed for lateral extension clamping the springs to the 70 Now it will be obvious that the spring construction 70 will normally function to maintain the hoist cylinder 26 in a vertical Iposition with respect to the base plate 64. owever, upon the raising of the body 13 by the plunger 27, the cylinder 26 will begin to tilt about its pivot towards the rear of the trailer 12. This movement will be resisted by the spring construction 70 nearest to the body 13. The degree to which the cylinder 26 will pivot about the axis of its pivotal mounting will depend upon the load in the body 13. That is to say, the tilting will be proportional to the weight of the load in the truck body 13.

. Each pulley 46 has passing over its groove a cable 80, one end of which is fastened to a channel beam 81 of the body 13 and the other end of which is fastened to an eyelet 82 secured to the base place 64. The pair of aibles 80 are utilized upon the raising of the pulleys 46 by the plunger 27 to raise the associated end of the body 13.

Associated with the cylinder 26 intermediate its ends is a ring of metallic material 90. This ring may be secured to the outer wall of the casing or cylinder 26 by any suitable means. This ring 90 constitutes a support for the flexible-connections to be hereinafter described. Fastened to this The bearing brackets 59 and 60 are seis connected to an outlet in the cylinder wall 26, designated by the reference character 93. The pipe line 92 may be provided with a a union 94 intermediate its ends to facilitate the disconnecting of the pi the cylinder 26 whenever it is esired. Also secured to the ring 90 is a tubular block 91' which is identical in construction to the block 91. Connected to this block 91' is a pipe line 95, the lower end of which comline from municates with an inlet 96 for the cylinder 26. The ipe line 95 is also equipped with a union 9 positioned intermedlate its ends. Since both t 1e blocks 91 and 91' are identical in construction, it is believed a descri tion of one will suflice for both.- Each lock 91 is provided with a lateral projection 98 having a tapered orifice portlon 99. The

projection 98 is tubular in construction and communicates with the pipe line associated with the block.

Associated with the projections 98 of the blocks 91 and 91' are a pair of flexible lines 100 and 101. The line 100 constitutes the inlet lead for the hoisting device and the line 101 constitutes the outlet for hoisting device. Each 0f these lines has an end provided with a metallic ring of material 102 to which is pivotally attached a yoke member 103 for straddling the associated projection 98. The yoke member 103 has an adjustable screw 104 adapted to be moved into engagement with the top of the corresponding ro'ection 98. The taipered portion 99 0? t e projection is a apted to be inserted into the end of the pipeline and the pipe line is adapted to be tightly held in lace on the projection by It should of course be understood that the inlet pipe line 100 is associated with the blok 91' communicating with the inlet pipe 95 and that the pipe line 101 is associated with the block 91 communicating with the outlet 93. The detachable connections, including the yoke members 103 previously described, enable the pipe lines 100 and 101 to be detached from .the hoist cylinder 26 with facility. This is particularly advantageous when it is desired to disconnect the trailer from the tractor.

Referring now to Fig. 1, it will be observed that the inlet pipe line 100 communicates with a three-way valve 105. The flexible pipe connection 101 has its other endconnected to a pipe 106 discharging into an oil tank 107. The upper end of the pipe 106 communicates with the three-way valve 105. The three-way valve is also connected by a flexible connection 107 to a pumpin mechanism, designated generally by the re .erence numeral 108. The pumping mechanism is connected by a pipe line 109 to the bottom of the oil tank 107. The oiltank 107 and the pumping mechanism 108 are preferably disposed intermediate the two gas tanks 19 and 20, previously described.

We have illustrated somewhat diagrammatically in Fig. 5 a three-Way valve construction 105 for controlling the operation of our hoist. The valve proper includes a T body 111, a valve member 112 and a han trated, the pump will be forcing fluid or oil to the hoisting cylinder 26. After the plunger 27 has been moved to its uppermost position, the oil entering the cylinder 26 from the pump will cause the plunger 27 to oscillate. This oscillatory movement on the part of the plunger 27 jars the body 13 and enables all of the contents to be dis-' charged therefrom quickly. Now, by operating the handle 110 to cause the valve member 112 to close the port 115, the pumping mechanism 108 will be disconnected from the three-way valve 105. in the plunger 27 forcing the oil out of the cylinder 26 through the pipe line 101, port 113, into the port'lll and into the tank 107, In other words when the port 115 is closed, the plunger 27 will be moved to its lowermost position.

On the other hand, when the port 113 is closed, the plunger 27' will not oscillate, but, on the contrary, will remain at a given raised position. The oil pumped through the line 107' by the pump 108 will be bypassed by the valve 105 into the tank 107. Thus it will be seen that through the threeway valve 105 liquid may be either pumped to the hoist, by-passed to the tank. or the oil in the cylinder 13 may be caused to be discharged into the tank or in the hoist plunger 27. I

We desire it understood that although we have described in detail the preferred embodiment of our invention, the invention is not to be limited thereby, but only in so far as defined by the scope and spirit of the appended claims.

We claim 1. The combination with a reciprocable plunger and a cylinder therefor having one end pivotally mounted of resilient means comprising two oppositely disposed leaf springs at each side of the cylinder, the ends This will result of said springs being fixedly mounted adjacent. to the cylinder support with the free ends of said springs slidingly contacting the cylinder surface for at all times urging the cylinder into a predetermined position and for resistin movement of the cylinder about its pivot.

2. The combination with a reciprocable plunger and a cylinder therefor having one end pivotally'mounted of resilient means for at all times urging the cylinder into a pre determined position and for resisting movement of the cylinder about its pivot, said means comprising a plurality of leaf springs independent of the pivot for the cylinder adapted to engage opposite sides of the said cylinder.

3. In a hoisting device including a pivoted hoist cylinder and a reciprocable plunger therein, resilient means for urging the plunger into a predetermined position, said means comprising a plurality of leaf springs independent of the hoist pivot and engaging opposite sides of the cylinder to resist movement of the same about its pivot.

4. In a hoisting device including a hoist cylinder, a re'iprocable plunger therein, and a pivotal mounting for the cylinder, resilient means associated with the mounting for resisting movement of the cylinder about its pivot, said means comprising a plurality of leaf springs independent of the pivotal mounting for the cylinder adapted to engage opposite sides of the said cylinder.

5. In a hoisting device including a hoist cylinder, a reciprocable plunger therein, and a pivotal mounting for the cylinder, resilient means associated with the mounting for resisting movement of the cylinder about its pivot, said means including a plurality of fixed leaf springs independent of the hoist pivot and having their free ends engaging opposite sides of the cylinder for maintaining the cylinder in a given position.

6. In combination in a hoisting device, a hoist cylinder, a reciprocable plunger therein, a pivotal mounting for one end of the said cylinder, a support for the said mounting, a lateral projection associated with the said support, a plurality of leaf springs asso ciated with the said projection and extending alongside the said cylinder, said leaf springs having their free ends associated with the said cylinder for resisting movement of the cylinder about its pivotal mounting, and means for actuating the said plunger.

7. In combination, in a hoisting device, a hoist cylinder,a reciprocable plunger therein, a pivotal mounting for one end of the said cylinder, a support for the said mounting, resilient means associated with the said support and in engagement with the periphery of the said cylinder for normally maintaining the cylinder in a substantially vertical hoist cylinder, a reeiprocable plunger therein, a pivotal mounting for one end of the said cylinder including a pair of bearings, a

support for the said bearings, a lateral exr tension connected to the said support, a plurality of leaf springs connected to the said extension, said springs extending alongside the said cylinder and serving to resist movement of the cylinder about its pivot, and means for actuating the plunger in the said cylinder.

9. In combination, an upright hoist member a pivotal mounting for the lower end of said hoist member, and means for yieldingly holding the hoist member in upright position and resisting pivotal movement of said memher about its pivotal mounting, said means comprising a pair of oppositely disposed leaf springs extending along and engaging opposite sides of the cylinder and mounted at their lower ends on opposite sides of the pivotal mounting for the cylinder and independently thereof.

10. in combination, in a truck including a hoist body, a hoist cylinder pivotally mounted on the said truck, a reciprocable plunger in the said cylinder andmeans for actuatlng the same, a connection between the plunger and the body for enabling the raising of one end of the body to discharge the contents thereof and a leaf spring construction comprising two oppositely disposed springs fixedl y mounted on the track with the free ends thereof slidably engaging the sides of the cylinder, said leaf springs being entirely independent of the pivoted mounting of the cylinder for normally maintaining the cylinder in a given position with respect to the truck and for resisting any swaying movenieutot the cylinder about its pivot during the time the said plunger is effective in holding the said end of the body in an elevated position.

In witness whereof, We hereunto subscribe our names this 7th day of April, 1926.

CLARENCE J. WEBER. BUY A. SEEK.

Images