US1434016A - Single-lift elevating truck - Google Patents

Description

R. M LOVEJOY.

SINGLE LIFT ELEVATING TRUCK. APPLICATION FILED 00129. I919.

Patented Oct. 31, 1922.

3 SHEETSSHEET I.

Fig. 1.

" n Ralph M. LQVGJOY byMMxW Atty/5 R. M. LOVEJOY.

SINGLE LIFT ELEVATING TRUCK. APPLICATION FILED OCT. 29. 1919.

1,43%,016. Patented 0ct.31,1922.

3 SHEETS-SHEET Z.

I nvemor. Ralph Ma Lovejoy by MkM Am/s;

R. M. LOVEJOY. SINGLE LIFT ELEVATING TRUCK. APPLICATION FILED 0CT.29, 1919.

' 1,434,016, Patented Oct. 31,1922.

3 SHEETS-SHEET 3.

Invenmn I Hqflph M. Love oy byMWkW Anya Patented Get. 31, 1922.

in srrss ear RALPH M. LOVEJOY, OF MEREDITH, NEW HAMPSHIRE, ASSIGNOR T LEWIS- SHEPARD COMPANY, OF BOSTON, TKASSACHUSETTS, A. CORPORATION OF MASSACHUSETTS.

SINGLE-LIFT ELEV'ATING TRUCK.

Application filedflctober 29, 1919. Serial No. 334,338.

To all whom it may concern:

it known that I, RALPH M. LOVEJOY,

a citizen of the United States and resident of M eredith, county of Belknap, State of New Hampshire, have invented an Improve ment in Single-Lift Elevating Trucks,

than In trucks heretofore constructed.

usual elevating truck constructions provided iior locking the load supportingmeans in elevated positions which are adapted to be released by the operator to pe'mit the load supporting means to descend toits normal position.

This other necessitates the use of a daslrpot or cushiomng device to prevent breakt the truck or inJuIy of the material carried by the load supporting means by the sudden dropping of the load. supporting means.

One of the principal objects of the pres ent invention is to provide means for locking the load supporting means in elevated positi on which can be released only upon.

re-engagement of the elevating mechanisms and re-elevation or the load supporting means sufliciently to impose the load upon the tongue so that the operator will have full control of the load before the load supporting means begins to descend.

Another object of the invention is to provide an elevating mechanism for the load.

supporting means comprising intere by th releasable ngaging members carried respectively e load supporting means and the elevating lever or tongue which tend normally to engage so that when the load supporting means is in elevated position re-engagement of the interengaging members may be at fected by depression of the elevating lever or tongue.

A further object of the invention is to the p provide means operable by the lowering of lattorm to position one of the interengaging mei'nbers out of operative relation to the other so that the tongue will be freed "for steering purposes.

Another object of the invention is to provide a novel means which will automatically engage and lock the load supporting means when it reaches elevated position, said locking means desirably beingprovided with a manually operable reversible counterweight which may be positioned alternatively to retain the locking means in operative position or to act upon the operating means in such a manner to tend to release it from operative position so that when the interengaging members are re-engaged and the load supporting means is moved slightly forward from its elevated position the locking means will be automatically released, thereby permitting the operator to lower the load.

A further object of the invention is to provide means automatically operable upon the descent of the load supporting means to reverse the position of: the counterweight so that the locking means will be restored to operative position.

Another object of the invention is to provide a truck in which the load supporting means is carried by parallel links with a link member of such a character that the wearing out of its pivot will be avoided and re placement unnecessary. This is accomplished by utilizing a strut which preferably is pivotally mounted at its lower end upon the rear axle ot' the truck and at its upper end provided with a rounded bearing member or members engaging within the angle or an angle plate extending transversely of the load supporting means.

Another feature of the invention relates to platform constructions in which the platform comprises atront end bar which may be in the form oi? a webbed casting of special construction and a rear end bar in the form of an angle iron arranged to pre sent a top horizontal surface and a vertical end suri'r'ace, the trout and rear end bars being connected by fiat side plates which lap around the ends of the rear end bar and are secured in the vertical sections thereof.

A. further object of the invention is to provide an extensible tongue by means of which a greater lifting leverage may be obtained.

Other objects and features of the invention will more fully appear from the fol-- lowing description and the accompanying drawings and will be pointed out particularly in the annexed claims.

A preferred embociment of my invention is illustrated herein as applied to an elevating truck comprising a main frame having a steering head with steering mechanism therein, said steering mechanism including a tongue pivotally mounted to provide a vertically swinging elevating mechanism and a load supporting mean carried on parallel. links, interengaging members being carried by said tongue and said load supporting means, whereby upon engagement of said interengaging members the load supporting means may be moved longitudinally relatively to the frame and simultaneously elevated through the action of the parallel links.

In the drawings:

Fig. 1 is a side elevation of a truck e1nbodying my invention showing the load supporting means in lowered position.

Fig. 2 is a similar view of the truck showing the platform located in elevated position, the rear portion of the truck being broken away,

Fig. 3 is an enlarged detail view of a portion of the steering mechanism. the load supporting means and frame illustrating the inter-engaging members of the platform and tongue being forced into engagement with the load supporting means in lowered position,

Fig. t is a side elevation of the front end portion of the truck with the load supporting means in lowered position viewed from the side opposite to that illustrated in. Figs. hand 2 and illustrating the locking mechanism,

F ig. 5 is a similar view showing the load supporting means locked in elevated position,

Fig. 6 is a plan view of a truck, the central portion being broken away,

Fig. 7 is a detail elevation of the interengaging member or hook which is pivotally mounted upon the load supporting means, and, v

Fig. 8 is a detail sectional view on line 8-8, F ig. 6, showing the strut which forms one of the parallel links for elevating the load supporting means, as pivoted upon the rear axle of the truck.

The preferred form of truck illustrated in the accompanying drawings comprises a head 1 which may be a casting comprising? aflat body portion preferably having a cylindrical upwardly extending boss 2 hnddownwardly extending end flanges 3 to which side bars 4 are connected. The side bars l are provided at their rear ends with brackets 5 providing journals 6 to receive the rear axle 7 of the truck. /Vheels 8 desirably are mounted. upon an axle 7 uponv the outside of the side bars a and are secured upon the axle by cotter pins or any other usual construction.

Preferably roller bearings are employed for the rear axles as is usual in trucks adapted to transport heavy loads. By reason of this construction the wheels can be readily removed from the axle after replacement or oiling without the necessity of dismantling the axle from the frame.

At its front end the truck is provided with suitable steering mechanism which may be in the form of a steering wheel 9 or pair of steering wheels journalled in the lower end of a yoke 10 having vertical steering post 11 journalled centrally in the cylindrical boss 2. (See Fig. 4.)

The upper end of the steering post 11 is provided with a bracket having upwardly extending ears 12 providing journals to receive the shaft 13 upon which the tongue 14 is pivotally mounted to swing vertically.

The tongue 14 desirably is in the form of an elevating lever having a bifurcated "rearward extension 15 the arms of which support an elevating member preferably in the form of a rod or bolt 16 extending across said arm. constitutes one of the pair of interengaging members which are carried by the tongue and platform respectively and are adapted when engaged to raise and lower the load supporting means upon vertical swinging movements of the tongue.

The tongue may be made in one piece but preferably is made in two sections, the lower section comprising the extension 15 and a split tubular member 17 integral therewith which is adapted to receive a pipe 18, which when forced into the split section 17 may be clamped therein by a bolt 19, thus forming a very rigid construction. The upper end of the tongue may be provided with a handle 20 which desirably is in the form of a pipe extending through a bracket 21 which is in the form of a split collar clamped upon the end of the pipe 18 by asuitable bolt 22.

In some instances it is desirable to provide an extension for the tongue in order that a greater lifting leverage may be obtained and to this end a cylindrical member 23 is telescopically mounted in the pipe 18, the member desirably being also tubular in form and provided with a suitable cap 24. In order that the extension 23 may be retained in any desired adjusted position frictional means are provided which are adapted to retain the same wherever placed. A

T he elevating member lti preferred mechanism comprises a rod 25 pivotally secured to the inner end of the extension 23, having at its opposite end a cross head 28 which fits loosely within the pipe 18. An expanding spring :27 secured split the pipe 18, consequently it have provided stop screw 28 extending through the pipe 18 into the path of the cross head 26 to limit the outward movement of the extension 23.

The load supporting means is in the form of a platform supported upon parallel links which are adapted upon forward movement of the load supporting means to cause its elevation.

I The platform which is illustrated herein is of special construction comprising a front end bar 29 having a strengthening web 30 and provided with forwardly extending bosses 31 in which a rod 32 is mounted which serves a pivot for the interengaging inember whichis carried by the load supporting means and also serves as means to be en gaged by the locking device which retains the load supporting means in elevated position. i

The end member 29 desirably also is provided with an integral upwardly extending flange 33 which serves as a dashboard to limit the forward position of the load which is placed upon the truck.

The platform also has a rear end bar 34c which desirably is in the form of an angle plate presenting horizontal top .tion 35 and a vertical rear section 36.

The front end bar 29 and rear end bar 30 are connected by side bars 37 which are secured to downwardly depending end flanges 38 on the front bar by rivets 39 and at their rear ends are bent around the ends of the rear end bar and secured by rivets 40 to the vertical section 36 of said end bar.

The platform frame thus constructed isof an exceedingly rigid character, Any suitable floor may be secured to the end bars or side bars to provide a closed platform if desired or the platform may be used in the sheleton form above described. The load sup 'iorting means or platform may be mounted upon parallel links in any suitable manner or may be sustained by any other means such inclined planes creams which will operate to raise the platform as it is moved longitudinall by the elevating meclr anisnn As illustrated in the accom 'ianying drawings the front end of the platform is carried upon links {ti which. are pivotally mounted to the rear end bar at their lower ends upon studs 4-2 carried by brackets 43 secured to the side bars a and at their upper ends are mounted upon the shaft 32 which is carried by the brackets 31 upon the front bar. At its rear end the platform desirably is mounted upon a special link in the form of a strut id having longitudinally and laterally extending strengthening welos the lower end of said strut being provided with bosses which are journalled on the rear axle '7 of the truck. The upper end of the strut ist is provided with hearing portions 46 which engage within the angle formed by the sections 35 and 36 of the rear end bar thereby providing the long bearing surface which will not wear to any appreciable extent during the life of the truck.

The upper end of the strut may be secured as above described by a plate or plates 4-7 bolted to the vertical section 36 of the end bar and having an ex tension 48 embracing a central preferably cylindrical portion 49 of the strut. The strut is provided with a suitable aperture 50 through its contra. portion to enable its connection to be made.

As before stated thefinterengaging members through which the elevating of the load supporting means or platform is accomplished are carried respectively by the tongue which acts as a lifting lever, and the platform. The member which is carried by the platform desirably is in the form ofa hook 51 having a downwardly turn-ed end 52 which may be caused to engage the rod 16 carried by the tongue extension 155. The hook 51 desirably has central reinforcing web extending throughout its length and at its bottom is secured to or formed inte ral 1 with a bracket 5% having downwardly extending ears 55 which are pivotally mounted upon the rod which carried in the bosses 31 of the front end bar 29.

The weight of the overhanging hook tends normally to cause it to fall. into engagement with. its oo-operating interengaging member or rod 16, and means are provided which will permit the hook automatically to assume a position to enga e the rod 16 upon depression of the tongue when the platform. is in elevated position so that the operator 1 by merely depressing the tongue reenn 'e the interengaging members and elevate the truck sufficiently to release the lock ing means and then lower the load. By

thus eliminating the necessity of operating ered position it would interfere with the lateral steering movement of the tongue. Means are therefore provided which act when the load supporting means is in its lowered position to withhold the hoolr from operative relation to the member upon the tongue which co-operates with to elevate the load supporting A preferred mechanism for accomplishing this purpose which is illustrated in the accompanying drawings comprises a hoolr posi loning member which is in the form of a linlr 56 which is pivotally mounted upon a stud 57 carried by ear 58 extending upwardly rrom the bracket 54:, and located at a considerable distance from the rod 32 upon which the hook is pivoted.

The link 56 has a downwardly extending a] .ovided at end with a foot 60 w h when the load supporting; means is in elevated. position en 'ap s one of the ears of the bracket 54 a; limits the movement of the hook in the manner hereinafter described so that its curved end 52 is retained in the path of the rod 16 which is :arried by the tongue extension.

The other end of the link 56 is provided with a slot 61 which is engaged by a stud 62 upon a hell crank lever 63 which is mounted upon a stud 6% extending through the flange or car 65 upon the head. 1 into the cylindrical portion 2 of said head The bell crank lever 63 is provided with. a pedal 66. T he slot 61 is so proportioned that the hell crank lever 63 may be operated through the pedal 66 to draw the link 56 forwardly and thereby force the hook downwardly into engagennent with the rod 16 of the tongue e1:- tension is illus rated in Fig- 3 when the platform is in lowered position.

A spring 67 connected at one end to the link 56 and at its opposite end desirably secured to an 68 upon the hook bracket 5% and quite closely adjacent to its pivotal support upon the rod 32 tends normally to force the'link endwise in a direction toward the load supporting means thereby causing the hook to be carried into the vertical position illustrated in Fig. i when the load supporting means is in lo o cred posit-ion.

.ls the load supporting means is raised and advanced during its elevating movement the link 56 is pivotally moved about the stud 62 on the bell crank lever 63 and when it is in suhstantially its evated position the foot 60 of the arm 59 engages the lower portion 55 of the hook bracket, thus limiting the endwis movement of the link and positioning the hook properly to engage the rod 16 upon the depression of the tongue. Consequently the positioning means acts to overcome the tendency of the hook to enits co-opcrating mber when tl. load supporting means is in lowered ositi-on and serves to remove the book from the path of the tongue extension so that the tongue may he moved freely laterally to steer thetruck. When the load supporting means is in eleposition the hook positioning means permits the hook to fall forward and retains it in a predetermined position in which it will engage the rod-16 on the tongue extension.

y reason of this construction a mechanism is provided by means of which the truck may be readily'drawn' or pushed in any direction without interference of the elevating mechanism with the steering mech-- anism when the load supporting means is in lowered position.

ll hen the load supporting means is in elevated position he hook is so located as not to interfere with the normal steering movements the tongue but is in proper position to he engaged by the rod 16 when the tongue is depressed for the purpose of raisthe load supporting means sufficiently to thus positioning the interenpgaging memso th they will enga when the load supporti means is in elevated position, by the depression of the tongue. the operator is nrhled to conven ently re-engage the elearing mechanism when he desires to lower the load and by reason of the fact that the locking; means cannot be disengaged until the load is sligh ly raised the operator is re quired to have full control of the load before the load supporting means begins to descend; conseouently the liability of dropping the load supporting means and the flying oi the tongue, by reason of an. improper relea e of the locking mechanism, is avoided.

The hook 53 is so sustained by the mechi 'n heretofore descrioed that when the load supporting means is in elevated position the oeak of the hook is in position to he eng n red by the depression of the handle to the position shown in 2 which is below the normal steering and hauling position or the handle.

The invention further contemplates the provision of means which will automatically lock the load supporting; means in elevated position. means also preferably being pro vided which may be manually operated to cause the locking means automatically to release when the elevating means are re-enstaged for the purpose of lowering the load supporting means.

The preferred locking mechanism comprises a hool-r shaped n ieinherv 70 which is pivotally mounted upon stud 71 carried in suitable bracketserr-tendingupwardly from the head 1. The beak 72 of the hook is curved sutliciently to embrace the shaft 32 which extends across the forwardend of the load supportin means when the platform as will hereinafter be more fully described.-

is raised to elevating position and to retain it until the load supporting means is moved forward preliminarily to the lowering operation. The hook preferably is provided with a downwardly extending strengthening web 73 which has an inclined surface 74 adapted to engage the rod 32 as the load supporting means is moved upwardly and forwardly and which acts as a cam to depress the hook until its beak 72 snaps beneath the rod 32. The hook 70 is also desirably provided with an upwardly extending stop 75 which will engage the rod 32 andlimit the forward movement of the load supporting means, thereby advising the operator that the load supporting means is in its predetermined elevated position.

The hook 70 is provided with an extension 76 beyond its pivot upon which a counterbalance is pivoted, which is adapted normally to maintain the hook in operative position to engage the rod 32 when the load supporting means reaches its elevated position and which may be reversed and caused automatically to release the hook when the platform is re-elevated for the purpose of lowering the same.

As illustrated herein a counterweight 77 is pivotally mounted upon a stud 7 8 at the end of the extension 76. This counterweight is of elongated form and has a laterally extending member adapted to engage said hook or its extension. When supported in the position illustrated in Figs. 4 and 5 the counterweight forms in effect a continuation of the extension 7 6 and is of sufficient weight to raise the hook into its operative position so that when the load supporting means is elevated the rod 32 will ride along the cam surface 74: until it engages the beak 72 of the hook whereupon the latter will be caused by said counterweight automatically to look upon the rod 32. By reversing the position of the counterweight about its pivot its weight may be shifted to the opposite side of the pivot as illustrated in dotted lines in Fig. 5 and when in such position will tend to depress the hook 7 and thereby to release its engagement with the rod 32.

In the operation of the truck the operator first raises the load until it is engaged by the hook, then transports the load to its destination. When he desires to lower the load he reverses the position of the counterweight 77 so that it will tend to depress the hook, then forces down the tongue until the rod 16 upon the tongue extension engages the elevating hook 51 and slightly advances the load supporting means. Thereupon the weight 77 causes the hook 7 0 todrop, thus releasing the load supporting means and permitting it to descend.

Means desirably are provided for restoring the counterweight to its normal position central in which it tends to hold the hook in operative position. This 'is accomplished by providing a link 7 9 which is pivotally connected to a stud 80 upon the front end bar and at its opposite end provided with a slot 81 which engages a stud 82 projecting laterally from the side of the counterweight adjacent its end, the proportions of'the link being such that as the load supporting means is lowered the stud 82 will engage the end wall of the slot 81 and upon further lowering movement will rotate the counterweight about its pivot. The slot 81 is of such length that it will not have any operative engagement with the stud'82 when the load supporting means is moved forward.

In operation, the truck is backed beneath the load which is to be'transported, the op erator steps upon the pedal 66 thereby drawing the hook positioning member or link 56 forward and forcing the elevating hook 51 into operative engagement with the rod 16 upon the co-operating interengaging member of the tongue.

The tongue is then depressed causing the load supporting means to advance toward the steering mechanism, it being in the meantime elevated by the action of the parallel links. As the load supporting means approaches its elevated position the rod '32 engages the cam surface 74 of the locking hook 7O depressing the latter until the beak 72 snaps around the rod 32 and further movement of the load supporting means is arrested by the stop 75 on the hook. I

The operator then raises the tongue and proceeds to draw or push the truck to its destination. During the elevating operation the hook positioning means has been so actuated that when thetongue is raised a the elevating hook 51 will remain in proper position to be engaged by the rod 16 of the tongue extension upon depression of the tongue, consequently when the truck has reached its destination and it is desired to deposit the load the interengaging members of the platform and tongue may be re-engaged by merely depressing the tongue. Before depressing the tongue however the operator reverses the counterweight so that when the tongue is depressed the locking I lowest position the elevating hook 51 will ing normally to engage, and

be forced into an upright position and held there, thus permitting free steering movement of the tongue.

It will beunderstood that the embodiment of the invention disclosed herein is of an illustrative character and is not restrictive and that various modifications in form and construction may be made'within the spirit and scope of the following claims.

Having thus described my invention what I. claim as new and desire to secure by Letters Patent is:

1. In an elevating truck com u'ising load supporting means and a pivotally mounted lifting lever, detachable interengaging means carried by said load supporting means and said lifting lever respectively and tend- 7 automatically operable means acting to withhold said interengaging means from engagement when the load supporting means isin lowered position and to position one of the members of said interengaging means when the load supporting means is in elevated position so that the depression of the lifting lever, below normal hauling and steeringv position, will cause engagement of said interengaging means.

2. In an elevating truck comprising load supporting means and a pivotally mounted lifting lever, detachable interengaging means carried by said load supporting means and said lifting lever respectively and tending normally to engage, automatically operable means acting to withhold said interengaging means from engagement when the load supporting means is in lowered position and to permit engagement of said interengaging meanswhen the load supporting means is in elevated position and manually operable means for causing engagement of said inter-engaging means when the load supporting means is in lowered position whereby the load supporting'means may be raised and lowered by the "swinging movement of said lifting lever about its pivot.

3. In an elevating truck comprising load supporting means and steering mechanism including a steering tongue pivotally mounted to provide a vertically swinging lifting lever, detachable interengaging means carried respectively by said load supporting means and, said tongue, means operating to withhold said interengaging members from interengaging position when the load supporting means is in lowered position, to permit lateral steering movements of said tongue and acting automatically as the load supporting means is raised to position one of said interengaging members in proper. rela tion to be engaged by the other upon depression of the tongue.

l. In an elevating truck comprising load supporting means and steering mechanism including a steering tongue pivotally mounted to provide a vertically swinging lifting le er detachable interengaging means carried respectively by said load supporting means and said. tongue, means operating to withhold. said interengaging members from interengaging position when the load supporting meansis in lowered position to permit lateral steering movements of said tongue and acting automatically as the load supporting means is raised to position one of said interengaging members in proper re lation to be engaged by the other upon depression of the tongue and to hold the positioned interengaging members in said relation while the load supporting means is in elevated position.

in an elevating truck comprising load supporting means andsteering mechanism including av steering tongue pivotally mounted to provide a vertically swinging lifting lever, detachable interengaging means carried respectively by said load supporting means and said tongue, means operating to withhold said interengaging members from interengaging position when the load supporting means is in lowered position to per- "nitlateral steering movements of said tongue and acting automatically as the load supporting means is raised to position one of said interengaging members in proper relation to be engaged by the other upon depression of the tongue and to hold the positioned inter-engaging member in said relation while the load supporting means is in elevated position, and manually operable means for causing interengagement of said interengaging means when the load supporting means is in lowered position.

6. In an elevatin truck comprising load supporting means and steering mechanism.

including a tongue pivotally mounted to provide a vertically swinging'lifting lever, a lifting member on said tongue, a co-operating. lifting member pivotally mounted on said load supporting means tending normally to engage the lifting member of said. tongue, automatically operablemeans connected to said co-operating lifting member acting to withhold the same from operative engaging position when the load supporting means is in lowered position and to place said co-operating lifting memberin engaging position when the load supporting means is in elevated position.

7. In an elevating truclr comprising load supporting means and steering mechanism including a tongue pivotally mounted to provide a vertically swinginglifting lever, a lifting member on said tongue, a hook pivotally mounted on said load supporting means, a hool; positioning member pivotally connected at one end to said hook above the pivotal support thereof and means acting to cause said hook positioning member to withhold said hook from interengaging relation to the lifting member of said tongue when the load supporting means is in lowered po sition and to position and ret 11 said hook in engaging relation to said hitting member when the load sumoorting means is in elevated position.

8. In an elevating truck comprising load supporting means and steering mechanism including a tongue pivotally mounted to provide a vertically swinging lifting lever, a lifting member on said tongue, a hook pivot ally mounted on said load supporting means, a hook positioning member pivotally connected at one end to said hook above the pivotal support thereof andmeans acting to cause said hook positioning member to with hold said hook from interengaging relation to the lifting member of said tongue when the load supporting means is in lowered position, said hook positioning member having a slot near its other end. and a manually operable lever having a stud. engaging said slot operable to cause said hook positioning member to force said hook into engagement with the lifting member of the tongue when the load supporting means is in lowered position.

9. In an elevating truck comprising load supporting means and steering mechanism including a tongue, pivotally mounted to provide a lifting lever, a lifting member on said tongue, a hook pivotally mounted on said load supporting means, a hook positioning member pivotally connected at one end to said hook above the pivotal support thereof and having a slot near its opposite end, a manually operable lever for actuating the same having a stud slidably mounted in said slot, and a spring connected to said hook positioning member and secured to said hook ata point adjacent its pivotal support tend ing to force the hook into inoperative position when the load supporting means is in lowered position and to position said hook in engaging relation to said lifting member when the load supporting means is in elevated position.

10. In an elevating truck comprising load supporting means and steering mechanism including a tongue pivotally mounted to provide a lifting lover, a lifting member on said tongue, a hook pivotally mounted on said load supporting means, a hook positioning member pivotally connected at one end to said hook al. ove the pivotal support thereof and having a slot near its opposite end, a manually operable lever for actuating the same having a stud slidably mounted. in said slot, a spring connected to said hook positioning member and secured to; said hook at a point adjacent its pivotal support tending to force the hook into inoperative position when the load supporting means is in lowered position and to position said hook in engaging relation to said lifting member when the load supporting means is in elevated position and neans on said hook positioning member for limiting the movement of the hook positioning member whcreliiy the hook will be retained in. operative position when the load supporting means is in elevated position.

11. in an elevating truck comprising a wheel supported main frame, steering mechanism including a tongue mounted to swing vertically, a platform movable longitudinally relatively to said frame and means for elevating said platform upon longitudinal movement thereof; releasable interenmembers upon said tongue and platform positioned to be engaged by the depression of the tongue when the platform. is in elevate position and means tending to remove said interengaging membes from interengaging relation upon raising the tongue when the platform is in a lowered position whereby the tongue will be freed r stecri purposes and means acting normally to lock said. platform in elevated position incapable of being unlocked until the in tere gaging members are engaged and the plati rm moved forward.

12. In an el vating truck comprising a wheel-supported frame, steering mechanism including a tongue mounted to swing vertically,'a platform movable longitudinally ively to said main frame, means for ting said platform upon relative longitudinal movement thereof, an extension upon said tongue having a lifting means, a hook pivotally mounted upon the front end of said platform and positioned to lie in the path of said lifting means of said tongue extension when the platform is in elevated position and means tending to remove and retain said hook out of engagement with said tongue extension when the platform is in lowered position whereby the tongue will be free for steering purposes.

18. In an. elevating truck comprising a wheel supported frame, steering means including tongue, a plat-form, elevating means connecting said platform to said tongue including a hook pivotallv mounted on said platform, means for normally holdtr i hook out of engagement with said tongue whereby free steering of the truckis permitted, a bell crank lever pivoted upon said platform and slotted link connecting said bell crank lever to said hook whereby actuation of said bell crank lever will force said hook into engagement with said tongue.

14-. In an elevating truck comprising a frame, a platform and means for elevating the platform, means for locking the platform in elevated position comprising a hook pivoted upon said frame, a member upon said platform adapted to be engaged by said hook and counterbalancing means movable elevated position comprising a hook pivoted upon said frame, acounterweight pivotally connected to said hook and means connecting said counterweight to said platform operable by the movement of said platform to shift said counterweight from one side of the pivot of said hook to the other whereby the hook will be alternatively sustained in operative or ii'ioperative position.

17. in an elevating truck comprising a frame, a platform and means for elevating the platform, means for locking the platform in elevated position comprising a hook pivoted upon said frame, a member upon said platform adapted to be engaged by said hook, at counterweight connected to said hook operable when the platform is in an elevated position to retain said hook in operative or inoperative position and means act-- ing automatically when the platform is lowered to cause said counterweight to retain said hook in operative position.

18. An elevating truck comprising load slmporting means, and steering mechanism including a tubular steering tongue pivotally mounted to provide a vertically swinging lifting lever, a tongue extension telescopically mounted in said tubular tongue, and frictional means operating to retain said extension in adjusted position.

19. An elevating truck comprising load supporting means, and steering mechanism including a tubular steering tongue pivotally mounted to provide a vertically swinging lifting lever, a tongue extension telescopically mounted in said tubular tongue a frictional member slidably mounted in said tubular tongue and means pivotally connecting said frictional member to said extension.

In testimony whereof, I have signed my name to this specification.

RALPH M. LOVEJOY.

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