US1430992A - Lifting truck - Google Patents

Description

S. HERTZ.

LIFTING TRUCK.

APPLICATION FILED MAY 10' I921.

Patented Oct. 3, 1922.

4 SHEETS$HEET 1 N Eye 01" S. HERTZ.

LIFTING TRUCK.

APPLICATION FILED MAY 10, 1921.

Patented 001;. 3, 1922.

' 4 SHEETS-SHEET 3 I S. HERTZ.

LIFTING TRUCK.

APPLICATION FILED MAY 10, 1921.

1,430,992; Patented 0017. 3, 1922.

4 SHEETS-SHEET 4. N I Q m L w Patented @ct. if), 1 .29322.

LIIF'JI'ING TRUCK.

Application filed may 10,

To all whom it may concern:

Be it known that l, STANISLAS ll-lnn'rz, citizen of the French Republic, residing at Paris, France, have invented certain new and useful Improvements in Lifting Trucks, of which the following is a specification.

This invention relates to lifting trucks with elevating mechanism for raising and moving loads upon platforms elevated from the ground by supports at the side.

The invention has for its object so to construct devices of the character just referred to in such a way that they are more certain in action, more simple in construction and consequently less costly than those hitherto constructed.

The truck is of the general type comprising an under framework upon which is mounted a rising and falling platform with means for clutching or looking the platform in the raised position and for declutching or unlocking the same; and one of the principal features of the invention consists in mounting the mec anism for efiecting the declutching upon the platform and in soconstructing and arranging such mechanism that, after declutching has been effected, the said mechanism may be utilized to assist the downward movement of the platform.

A second feature of the invention consists in providing, for the purpose of raising. the

platform to the elevated position, a hook pivotally mounted upon a transverse axle upon the platform and in providing upon the pivoted handle, by means of which the truck may be drawn or pushed, a projecting rod or other device with which the hook can engage. Means are also provided for holding the hook, when free, in such a position that in order to bring the rod or its equivalent into engagement with said hook, it is simply necessary first to push the handle towards the truck and then to draw the said handle back.

A third feature of the invention consists in forming or providing the end of the framework of the truck opposite that to which the handle is pivoted with a prowshaped portion, which enables the truck to some extent automatica-lly to adjust itself in the correct position between the side supports of the platform to be raised thereby,

192i. aerial No. 468,347.

even when the truck is pushed in a direction co-inciding only approximately with the axis of the platform.

The invention also refers to certain constructional embodiments of mechanism, for carrying out its objects, which constructional embodiments will be described more fully in connection with the accompanying drawings, which however are given merely by way of example.

Figs. 1 and of the drawing show respectively in side elevation and infront elevation, one-form of truck embodying the invention, the platform being shown in the raised position.

Fig. 3 shows thesame truck with the handle removed, the lower portion of the view being a true plan, and the upper portion a plan with certain parts removed.

Fig. 4 shows the truck in a similar manner to Fig. 1, but in this case the platform is in the lowered position, and the handle is turned into the position for enabling the platform to be raised.

Figs. 5, 6 and 7 show respectively in part side elevation, in part front elevation, and in part plan, the front portion of another truck containing another embodiment of the invention, the platform being in the raised position.

Figs. 8, 9, and 10 are views similar to Fig. 5, illustrating different positions of the handle and the platform. v

The trucks illustrated in the drawings are of the type to which the invention can be applied with the greatest advantage and they comprise a platform a and an under framework b, connected together by links a, so arranged that the platform and the frame constitute with them a hinged parallelogram enabling the platform to be suitably raised or displaced with regard to the framework. A brake d of the usual character is also provided, such for instance as a hydraulic brake so as to prevent the platform returning too suddenly to the lower position when it is loaded and declutching takes place.

Referring now to the features to which the invention more particularly relates, these are constructed and proportioned so as to harmonize with the other constructional details, but substantially as follows 1- is mounted by means of a universal joint isformed more or less in the shape of a prow, so that the truck may be pushed conveniently between the side supports of the platform or transporter,-not shown on the drawings.

The means for raising the platform a, are constructed substantially as follows e is the handle, pivoted upon a transverse axle at its lower end to a part bfiwhich part is itself adapted to rotate in suitable bearings about a vertical axis located at the middle of'the front of the frameworkb. The lower end of the handle is formed or provided with an extension approximately at right angles thereto, 0

f f are two hooks, each of which is pivotally mounted upon a transverse axle, such for instance as an axle g with a support 9 This mounting is effected near the front of the platform a, so that the hooks are symmetrically placed at equal distances on either side of the longitudinal axis and are somewhat further apart than the width of the part 5 Each of these hooks is provided on the side which is uppermost when the hook is extended horizontally forward, either with a single engaging portion f as shown in Figs. l l; or as an alternative, and preferably, it may be provided with a pluralitv of engaging portions, as illustrated in Figs. 5-10, where two such portions 7' and f are furnished.

h are two powerful resilient plates or leaf springs. These are mounted at one end on the forward extremity of the lower framework b, so that they extend longitudinally on each side, the other extremities being rearwardly directed and adapted to support the hooks f. This may be effected either as shown in Figs. 1-4 by providing at the outer faces of the hooks projections f of suitable length; or alternatively and as shown in Figs. 5 10, the free ends of the plates or springs k may be connected by the bar 72. adapted to support the hook.

i is a short bar or shaft provided on the lower extended portion 6 of the handle 6, and projecting transversely and so arranged that it constitutes means for bringing the handle into engagement with the hooks f when the said handle is turned into the appropriate position.

j j are looking pawls, one or more of which may be provided. The pawls are keyed to transverse shafts k carried by suitable bearings at the front of the platform a.

Each of these pawls is provided at the side which is directed downwards, when the pawl is turned so that it points forward in a horizontal direction, with one or more projecting points j", or j", j equal to the number of the stages of elevation.

Z Zare steps, corresponding in number to the pawls and provided on the framework 5, so that the engaging point of the pawls lock with them, when the platform a is raised from its lowermost position to one or other of its higher positions: the result being that after this locking has taken place, the platform is held in the desired position.

In the preferred construction the relative dimensions and arrangements of the parts.

are as shown in the drawings.

In order to raise the platform a from its lower position to the upper position, it is necessary to proceed as follows The handle e is pushed towards the back of the framework, so as to bring the projecting shaft 2' over the engaging portions f of the hooks 7", which hooks are yieldingly supported by the leaf springs 72-. It is to-be noted that as thehandle e is pushed back wards the projecting shafts i press down the hooks f against the upward push of the leaf springs h. lVhen the shafts i have cleared the ends of the hooks, the latter are pushed upwards ready to engage the said shafts upon the return of the handle. The said handle 6 is now pulled forward and, as just stated, the shafts i engage with the portions f of the hooks, and the movement of the handle 6 is continued until the platform 0. has been raised sufficiently to bring the projecting end j of the pawl j into engagement with the corresponding catch or step Z.

If the method of construction is that shown at Figs. 1 when the platform has been brought into the raised position, on again pushing back the handle 6, the projecting shafts i are disengaged from the portions f? and the hooks being released again rest upon the leaf springs h, from which they were removed during the raising of the platform. The handle 6 itself is consequently freed and may then be utilized in the ordinary way for pushing or pulling the truck.

On the other hand, if the methodof carrying out the invention isthat illustrated in. Figs. 510the construction which is preferably utilized where relatively heavy loads have to be dealt with, without the use of great power, by spreading the effort over a number of platforms-the platform a is only raised into an intermediate position by the foregoing operations and after the handle 6 has been pushed backwards and drawn forwards as just described, the operation is again repeated so that, as shown in Fig. 10 the projecting shafts i are en aged in the portions f of the hooks. an then when the handle e is again pulled towards the front the platform is again raised, the result being that the projecting points 3' of the pawls engage with the steps or catches Z. The handle a is then liberated as previously I naeoeea described in connection with the form of the invention shown in l igs. l-d.

tion, even 'wheuno load is placed upon the. platform, and againstthe resistance, exerted hy the brake.

The pedal 'm is rigidly connected with oneor more of the pawls j for instance as described through the shaft kmounted in bearings 7: upon the platform. Moreover the hearing is slotted so as to allow a certain amount of play, so that, when the pedal is operated, it first of all causes the pawlor pawls to be disengaged thus effecting the declutching, after which, owing to the pedal.

coming against the end a, n of the slot, on

further operating the pedal it causes a certain. amount of force to he applied directly to the platform in the required direction for causing it to descend or for assisting it in its descent. t

in some cases in addition to providing the edal mechanism just described, a finger 0 is provided interconnected with the pawls ,and so disposed with respect to 'a stop or the like 20 provided. on the framework 6 that, when the pedal m has been operated and declutching takes place, the said finger 0 comes into contact with the stop 12 the result being that the platform is pushed backwards as it moves downwards, whence again" the force exerted on thepedal assists in causing the motion. desired.

nits will he clearly; understood, and as has already been remarked, the invention is not limited to those ethods of carrying it out which have been described and shown on the ters accompanying drawin s but includes all modifications fallin within a fair-interpretation of the claims. 7

What I claim and desire to secure by Let- Patent of the United States of America l. lln a lifting truck, the combination of a lower framework mounted upon wheels, a platform, parallel links connecting the framework to the platform'and enabling the.

latter to rise into an elevated position, a brake for counteracting the downward movementofzthe platform, a pivoted handle connected to the framework, a hook pivoted to a transverse axle at the front of the platform, a projectin shaft attached transversely to the hand e and adapted to engage connected to the framework, an arm said hook, a resilient blade upon which the back of said hook is adapted to rest in position to automatically engage said projecting shaft when the handle is moved in one direction, means for locking the platform in the raised position and means for disengaging said locking means to lower said platform 2.111 a lifting truck, in a lower frame work mounted upon wheels, a. platform, parallel links connecting the frame work to the platform and enabling the latter to rise into an elevated position, a brake for counteracting the downward movement of the platform,

a'pivoted handle connected to the framework, an arm pivoted to'said platform and having a series of hooks, a projecting shaft attached transversely to the handle and adapted to successively engage said hooks, a resilient member upon which said arm rests in position for said hooks to he automatically engaged by said projecting shaft when said handle is moved in one direction, means for locking the platform in its successive stages of elevation and means for disengaging said locking means to lower the platform.

3. In a lifting truck in combination a lower framework mounted upon wheels, a

platform, parallel links connecting the framework to the platform and enabling the latter to rise into an elevated position, a

brake for counttracting the downward movement of the platform, a pivoted'handle connected to the framework, a hook pivoted to a transverse axle at the front of the plat form, a projecting shaft attached transversely to the handle and adapted to engage said hook to raise the platform, means for holdingsaid hook in position to automatically engage said shaft when the handle is moved'in one direction and means for automatically looking the platform in the raised position when the handle is moved in the opposite direction comprising a stop on said framework and amember pivoted to said platform having means for engaging said stop, a treadle secured to said member adapted to release said locking means and an arm for said member adapted. to engage said framework.

d. in a lifting truck in combination, 'a lower framework mounted upon wheels,--a platform, parallel links connecting the framework to the platform and enable the latter to rise into an elevated position, a brake for counteracting the downward movement of the platform,apivoted handle ivoted to a transverse axle at the front of the platform, a plurality of hooks on said arm,

a projecting shaft attached transversely to combination lot which seid arm is adapted to rest in posi tion for said hooks to be autemeigically ens gauged" by said transverse shafi; when, the arm is moved in one direction means for looking the p1atf0rm in its Successive stages of elevation comprising a stop onsaid framework, a member pivotally mountedon. a shaft secured to the letform and having means for engaging said stop eteech stage of elevation of the plstforin, a, tfeadle seemed to Iseid. pivotally mounted member,-

said- .tresdle havingstops to limit its-m0- tion and an arm on said pivotal member eirgaging said framework:

In testimony whereof I have hereunto set my hand STANISLAS

Images