US2669421A - Lifting and transporting truck - Google Patents

Description

Feb. 16, 1954 J. B. WILLIAMS LIFTING AND TRANSPORTING TRUCK Filed Oct. 12, 1951 2 Sheets-Sheet 1i IIL Inventor John .Brynm or Williams A Home y Feb. 16, 1954 J. B. WILLIAMS 2,669,421

LIFTING AND TRANSPORTING TRUCK Filed Oct. 12, 1951 2 Sheets-Sheet 2 Inventor John .Brynmor Williams I y 3% SPQMQTA, 23mm ttorney Patented Feb. 16, 1954 LIFTING AND TRANSPORTING TRUCK John Brynmor Williams, Parbold, near Wigan, England, assignor to Ajax Trucks Limited, Manchester, England, a British company Application October 12, 1951, Serial No. 250,993

3 Claims.

This invention relates to that kind of lifting and transporting truck wherein the carrying platform is lifted by means of a lifting lever.

According to the said invention, a lifting and transporting truck of the hereinbefore specified kind has a link which is jointed by connections including a universal ball joint to the lifting 1ever and to a part connected to or associated with the carrying platform, and operates to transmit motion from the lifting lever to the said part. The connections preferably also include an articulating joint of a different kind from the said universal ball joint.

The lifting lever is preferably operated by a handle lever adapted to push the lifting lever positively in the upward lifting direction but leave the lifting lever free to move independently of the handle lever in the return direction.

The lifting lever and handle lever are preferably arranged to swivel about a vertical axis and be also capable of operation in the upward lifting and return directions when in different angular positions relative to the said vertical axis, whereby the platform can be raised and lowered and the truck can be pushed or pulled by the handle lever whilst it is in different angular positions.

The lifting lever and handle lever are preferably both pivotally mounted to rotate about the same. axis, the lifting lever being accommodated by a gap in a forked end of the handle lever.

The link is preferably provided with a ball which engages a ball socket on the said part.

The link preferably has additionally a bearing provided in it and engaging a ball segment provided on the lifting lever.

Preferably, the link and the lifting lever cooperate, in the uppermost position of the carrying platform, to produce a toggle action whereby the carrying platform can be locked in a raised position.

A pedal or lever may be provided which when operated displaces the link and lifting lever from the carrying platform locking position, and thereby causes them to cease to perform a toggle action.

The pedal or lever is preferably provided on the handle lever so that it becomes operative only when the handle lever is in an out-of-use position where it cannot be forced upwards by the descent of the carrying platform and therefore cannot strike the operator.

A transmission member for transmitting motion. from the handle lever to the lifting lever in the lifting direction only is preferably provided of the arrow shown in Figure 1; and

on the handle lever and is adapted to be shifted into an inoperative position by hand.

A locking device is preferably provided between the transmission member and the handle lever for releasably locking the transmission member in an inoperative position.

A handle lever locking device is preferably provided for cooperation with a bracket on the truck chassis frame for releasably locking the handle lever in an out-of-use position.

In the accompanying drawings- Figure 1 is a fragmentary side elevation of a lifting and transporting truck;

Figure 2 is a detached side view illustrating a. detail, some of the parts being shown in different positions from thoseshown in Figure 1;

Figure 3 is an end view taken in the direction Figure 4. is a detached end view, partly in section, illustrating a detail.

Referring to the drawings, in the construction shown therein, a truck chassis frame I having a pair of wheels 2 mounted on horizontal axles 3 and a caster wheel 4, has pivoted on it two pairs of coupled bell-crank levers one bell-crank lever of each pair being designated 5 and 6 respectively. The bell-crank levers 5, 6 have pivotally mounted on them a platform frame 1. The platform frame I may, as shown in Figures 1 and 3, carry a carrying platform 8, according to the purpose for which the truck is intended, The

platform frame I has at one end, which terminates short of the caster wheel 4, an upwardly projecting part 9 having a horizontally extending portion Hi.

The caster wheel 4 is mounted in a caster fork i I having a vertical ofiset spigot I2 which is journalled in a ball bearing [3 provided ina part 14' of the truck chassis frame I. An upwardly projecting lug or bracket I4 is journalled on the part 44' of the truck chassis frame I to rotate independently of the caster fork II. The lug I4 is connected by means of a pivot pin l5 to the forked lower end of a handle lever 15, the lug H extending into the gap between the prongs of the handle lever fork and being mounted on the pivot pin 5 to be rotatable independently thereof. A

lifting lever l1 comprising two similar plates and therefore being a double lever has its two plates extending between the prongs of the handle lever 15 and has the lug l4 between its two plates. The lifting lever I! is mounted on the pivot pin i5. so that the lifting lever IT. can rotate independently of the pivot pin l5. The part M is a pivoting means common to the lifting lever l'l and the handle lever l8 and is also a bearing for the lug ill by which the lifting lever 11 and handle lever 16 are rendered swivellable on the truck chassis about a vertical axis. A lateral pin it is shiftably mounted on the handle lever l6 and is arranged to exert a rotative force on engagement thereof with shoulders IS on the plates of the lifting lever ll when the handle lever 16 is rotated downwards on the pivot pin H in the platform frame lifting direction, but to exert no rotative force on the lifting lever if when rotated on the pivot pin in the return direction. The pin it is therefore a transmission member transmitting motion from the handle lever Hi to the lifting lever H. The pin I8 is connected to the ends of the arms of a hoop which is on the handle lever IE and can slide longitudinally relative to the handle lever l6. Slots 2| are provided in the handle lever it for the pin l8 which projects therethrough and can move a distance in respect thereof sufdcient to allow the pin I8 to pass out of register with shoulders 19 on the lifting lever 11 when the hoop 2! is lifted. The hoop 20 has a handle portion 22 which can be hooked on to a projection 23 on the handle lever i 6 to hold the hoop 29 in its lifted position. The portion 22 and projection 23 together form a locking device for releasably locking the transmission member in an inoperative position. A pair of springs 24 is provided normally to urge the hoop 20, when not hooked in its lifted position, into its lowermost position wherein the pin i8 registers with the shoulders it on the lifting lever i1. By these means, the handle lever can be disengaged from the lifting lever and swung downwardly without raising the platform 3.

The plates of the lifting lever H are secured together by a member which has a ball segment 25, namely a ball with fiat sides, and is attached to the plates by means of opposed screwthreaded spigots 25 forming pivot studs projecting from the sides of the ball segment 25 into holes in the plates and having securing nuts 2'! screwed on them. The ball segment 25 is connected to the lower end of a link 28 by providing a bearing 29 in the link, the surface of the bearing 29 being spherically curved and the bearing 29 having the ball segment 25 mounted in it so as to surround the ball segment 25, whereby the ball segment 25 is held against separation from the link 28. The bearing 29 and ball segment form an articulating joint between the link 28 and the lifting lever 11. The said joint transmits motion from the lifting lever I! to the part 9 by the link 28 with a toggle action. The link 28 forms a tog le joint. of the bearing 29 is preferably porous oil impregnated metal.

The metal forming the bearing surface The link 23 extends upwards and its upper end is provided with a universal joint ball .30 by having screwed into a screwthreaded hole in its upper end, a screwthreaded spigot provided on V the ball 39. The ball 36 is connected to the horizontally extending part ll) of the platform frame by being permanently mounted in. a ball socket 31 having a spigot 32 screwed into a screw threaded hole in the part it and having a pad of bearing metal (not shown), preferably porous oil impregnated metal, with a spherical bearing surface for the ball. The ball socket 3| and ball form a universal ball joint and the ball 30 is held against separation from the socket 3! by a cuff -33 screwed on to the socket 3i and having a restricted end orifice of less diameter than the ball 30.

A framework 34 attached to the truck chassis frame I forms an immovable bracket and has a catch recess 35 for co-operation with a handle lever locking device comprising spring loaded catch 36 provided on the handle lever Hi to lock the handle lever It in an upstanding, out of use position, the catch 36 being withdrawable against the action of the spring load by means of a hand operable handle '37 provided inside a larger stirrup-shaped part 38 of the handle lever I6.

The lifting lever IT has on each of its plates a shoulder 39 and the shoulders co-operate with stops 40 on the lug 14 to limit the pivotal move-- ment of the lifting lever in the anti-clockwise direction so that the centre of the ball segment joint 25, 29 can be rotated into a position beyond the point where it is in line with the centres of the ball joint 39, 31 and the pivot l5 and be prevented by stops Ml and shoulders 39 from rotating beyond that position. In the said position, gravity operates to keep the parts in the said position and therefore the platform remains in its up position. The dot-and-dash line 4|, 42 makes clear it e locking condition.

To release the platform from its up position, the lever if and fink 23 are displaced manually about their respective axes of rotation in clockwise direction until the centre of the ball segment joint 25, 29 has moved beyond the said point, and

= thus enables gravity to continue movement of the said parts in clockwise direction and thereby allow the platform to sink into the down position. Horizontal offsetting of the centres of the pivot 15 and the ball joint 30, 3| as shown ensures the ability to move the parts into the said position at will. a

In operation, when the handle lever 18 is in the locked position, the platform frame 1 is in the down position. The handle lever I6 is released by operating the catch 36 by means of the handle 3'! and the platform frame I is lifted by rotating the handle lever l6 about the pivot pin i5 whilst the hoop 28 is in the position shown in Figure 1 relative to the handle lever H5. The pin l8 impinges against the projections I9 on the lifting lever l1 and thereupon rotates the lever i! on the pivot pin (5 to force the link 28 upwards. The upwardly forced link 28 pushes the horizontally extending. part Ill of the platform frame I upwards and the platform frame 1 is thereby swung upwards on the bell-crank levers 5 and 6. The ball segment 25, hearing 29 and universal ball joint 30, 31 by which the link 28 is connected to the lifting lever H and the platform frame I allow arcuate movements of the lifting lever and the different arcuate movement of the platform frame I to take place irrespective of the momentary angular position 'of the handle lever! 6 and lifting lever 11, about a vertical axis, whilst ensuring a strong simple and enduring force-transmitting connection between the parts.

When the lifting platform is up it is locked temporarily in the up position by the hereinbefore referred to toggle action and can be unlocked by the trip pedal 43. In order to guard against release of the platform whilst the handle lever is in any other than an upstanding position, with the consequent risk of the operator being struck under the chin by the handle lever, the means consisting of the pedal 43 cannot operate on the link 23 unless the handle lever is in a safe upstanding position.

The platform canbe made to descend slowly in known manner by dashpot or other means which form no part of this invention.

Iclaim:

1. A lifting and transporting truck comprising a truck chassis, a carrying platform movahly mounted on and supported b 3 voted link on said chassis for lifting with respect the an upwardly projecting part directly connected to said carrying platform one end thereof, a hall socket provided on part at the end thereof, a call engaging socket, a link having said hall at one end, the said socket and ball forming a universal ball joint between said part and said link, a lift lever provided on the truck chassis in the vicinity of the said link for lifting said carrying hall segment on said li Ag lever, a hearing provided at the other end of said link engaged by hall segment forming therewith an articulating joint between said link and said lifting lever for transmitting motion from said lifting lever to said part by link with a toggle action EJ115138 by the lifting lever and link support said carrying platform in a lifted position, a handle lever mounted on the tract; chassis for pushing said lifting lever positively in. the upward lifting direction, a shoulder on the lifting lever, a transmission member shiitahly mounted on said handle lever and transmitting motion from said handle lever to said lifting lever lay engagement With said shoulder in the platform lifting direction only whilst leaving said lifting lever free for movement independently of handle lever in the reverse direction, a loc i handle lever for releasahly lo sion member in an inoperative position, an movable bracket provided on said chassis, a handle lever locking device provided on the handle lever at its upper part for locking said handle lever to said bracket in an out-of-use position of said handle lever, a trip pedal rockalol mounted on said handle lever and situated in close proximity to the said lin: only when the handle lever is in its outf-use position, in which position of the handle lever op eration of the trip pedal displaces said link and said lifting lever from the position in which they support the carrying platform in the lifted position and thereby cause the lifting lever and link to cease to support the platform in the said position, pivoting rneans provided on the truck chassis and common to said lifting lever and said handle lever, a forked end provided on the handle lever and engaged by said lifting lever, and a bearing on the truck chassis by which said handle lever and said lifting lever are mounted swivellably on truck chassis about a vertical axis.

2. A lifting and transporting truck comp-rising a truck chassis, a truck platform liftably connected to the chassis by pivoted link means, a toggle joint operatively connected at its ends to the chassis and platform for lifting the platform, a stop on the chassis which limits the extent of angular motion of the toggle joint for locking the said joint against further movement in one direction after it has passed its state of full extension, a lifting and hauling handle have con-- nected to the chassis, a retractable pin on the er, a shoulder on the toggle joint enthe for operation of the toggle platfo m lifting direction, a rockable lvct iy mounted on and participatnts and changes of position or relative to the toggle joint, being located operativeiy close to only when the handle lever is perative position and usable in that position, for joint in the platform by fcrcec impingement tthe saidtoggle joint.

3. A lilting transporting truclr comprising in combination, a chassis, a platform liftably -mounted thereon oy pivoted link means, a bracket secured to one end of the platform, a hall socket se to the upper end of the bracket, a ha l permanently mounted in the ball socket, a link of which the upper end is formed by ball, a ng at the lower end of the link, a bearing surface in the said hearing, hall permanently mounted in the he ring, extending pivot studs on the lever is canted, a pivot pin on the t whereby e double lever is mounted on 1 a bearing on the chassis vhy the bracket is swivellahly mounted on re cha e? a handle lever mounted on the said straddling the double lever and "ing to lift platform and haul and push truck, a stirrup slidable on the handle lever, a catch pin secured to shiftable by the ""lilltip, the lever having slots for the catch pin to slide in laterally, a shoulder on the lever for transferring motion, when enicy said catch of the handle lever to the doc is lever in the platform lifting direction, stop on the bracket for limiting the extent of movement of the double lever in the said direction, a second houlder on the double lever co-operation with the stop on the bracket, and means on the handle lever which can be operated to trip the link only when the handle is in a position corresponding to the lowered position or the platform.

JOHN BRYNMOR WILLIAMS.

llteierences Cited in the file of this patent UNITED STATES PATENTS

Images