US2402579A - Load lifter - Google Patents

Description

June 25, 1946. w. A. ROSS 2,402,579

LOAD .LIFTER Filed May 24, 1945 5 Sheets-Sheet l 7 June 25, 1946. w. A. Ross 2,402,579

LOAD LIFTER Filed May 24, 1945 -3 Sheets-Sheet 2 IN VEN TOR.

Patented June 25, 1946 UNITED STATES PATENT OFFICE LOAD LIFTER William A. Boss, Springfield, Ill., assignor to Weaver Manufacturing Company, Springfield, 111., a corporation of Illinois Application May 24, 1945, Serial No. 595,505

2 Claims. 1

Substantial advancement in the structural and functional properties of load elevating and loading appliances constitute the subject matter of the present invention whereby to afiord mechanisms of this general character with constructional features which permit the devices to operate to substantially better advantage than heretofore.

Among the various aims of the invention may be mentioned the provision of an apparatus of this type which avoids complexity of construction, which may be manufactured at comparatively small cost, and which functions advantagously and efliciently.

To enable those skilled in this art to understand the invention and the advantages which accrue from its employment a present preferred embodiment of the invention has been illustrated in the accompanying drawings forming a part of this specification and to which reference should be had in connection with the following detailed description, and, for simplicity, like reference characters have been employed to designate the same parts throughout the several views of the drawings.

In the drawings:

Figure 1 shows the appliance in elevated relation in perspective;

Figure 2 portrays the apparatus in perspective in its lowered condition;

Figure 3 is a side elevation of the mechanism in partially raised condition;

Figure 4 is a similar view of the structure in further depressed relation;

Figure 5 is a plan of the construction with its supporting carriage or saddle, denoted as a whole by the reference numeral l5, and which may be of any suitable size, shape and form, depending upon the type of load to be elevated, includes twin, transversely-registered, pantograph-linkages each having, in the present instance, three pairs of channel-bar links l6, l6, l1, l1 and l8, [8, each hinged at its middle at l8 to the center of its companion link of the pair and also hinged 2 to ends of other links at 2|, all in the well known pantograph arrangement.

One I it of each pair of upper links at its top is hinged at a fixed point 22 to the corresponding side of the forward portion of carriage IS, the upper end of its companion link 18 being hinged at 23 to a frame 24 slidable lengthwise in the sides of the longitudinal channel-bars constituting parts of the carriage I 5, whereby such end of each of the specified top links H8, H8 may travel lengthwise of the carriage during its up and down movements.

The lower end of each of the two links it is hinged at 25 to the corresponding chassis, side channel-bar and the lowermost end of each of the companion links I I6 is provided with a roller at 26 adapted to travel forwardly and rearwardly in a channel guide-bar 21 fixed to the outer face of the answering side-bar of the chassisframe.

To actuate these two, complementary, transversely-registered pantograph-linkages simultaneously, the following means is provided.

An oil-pump 28, operated by rocking handle l4, feeds oil under pressure into a horizontal cylinder 29 hinged on the chassis at 30, the piston-rod 3| of the piston (not shown) in the cylinder being rockingly connected at 32 to the short arm of a bell-crank 33 fulcrumed at 34 on a stationary bracliet 35 mounted on the chassis. the longer arm of the bell-crank being joined by a short link 36 to the pivotal connections IS. IS of the two pairs of links l6 and I It as by a crossrod or shaft I31 at that point.

Obviously, as the oil under pressure enters cylinder 29, its piston-rod 3| rocks the bellcrank 33 around its fixed axis 34, thus swinging the longer arm of the bell-crank up and forcing both pantograph-linkages and their common carriage up by the force applied through the connecting link 36.

It will be clear that when the operative parts are collapsed, as portrayed in Figure 7, the cylinder and its piston-rod are not in such position to apply its power to best advantage and it is therefore desirable to employ a booster means to assist such main operating mechanism during the first or initial portion of its action, that is to say, until its parts have changed their .position to render them more efflcient and effective.

Accordingly, the following additional or supplemental power-operating medium is employed during the introductory or inaugural action of the main power means.

As presented, perhaps most clearly in Figure 6, a smaller auxiliary or booster cylinder 21 is hinged or pivoted at 38 on the long arm of the bell-crank, the turning of such cylinder about the axis 38 being limited or restricted by the adjacent mechanical parts, the piston-rod 39 of the piston in the cylinder having a rounded head or end 41 adapted to coact with a complementary, concave, .socket member 42 welded or otherwise fixedly secured to the two links l8, l8 and adapted to rest on the head 4| during the first portion of the upward action.

The lower portion of the interior of the smaller cylinder 31 is connected by a flexible conduit 43 joined to the interior of cylinder 29 so that the oil under pressure operates the pistons in both cylinders at the same time.

Assuming that the appliance is in the completely folded, lowermost condition, as depicted in Figure 2, and that it is desired to raise a load resting in the seat or carriage IS, the operator by manually rocking or oscillating handle [4 simultaneously pumps oil under pressure into the main and booster cylinders 29 and 31, respectively, thereby initiating the elevation of the carriage and its load through the piston-rod 3|, bell-crank 33, link 36 and the pair of pantograph-linkages, this action being aided and facilitated by the upward pressure ofpiston-rod 39 acting on the same linkages through the coacting part .39 and 42, the cylinder, piston and pistonrod rocking somewhatas they ascend by the conjoint-action of .part 42 with the end of the piston-rod.

By the time the main operating means reaches a condition and position of cooperating elements to more eillciently and forcefully perform its lifting action, the link l8 will have risen sufllciently to raise the cap 42 away from the piston-rod l9 and the latter will remain inactive because it has reached its limit of extension.

when the carriage is to descend the usual 11:-

lease-valve (not shown) of the pump discharges the machine is equipped with a pair of outrlgsers 5|, 5| hinged to the opposite sides of the chassis extended, active positions or folded back against the chassis in inoperative positions.

The arms of these Outriggers have adjustable Jack-screws SI, 53 at their free ends with groundengaging discs or feet 54, 54.

Manifestly, by turning the jack- screw cranks 55, 55 and thereby setting the height of these arms the appliance may be stabilized or it may be tilted, if desired, to either side if necessary when in raised position.

As the appliance has been used as a bomb loading truck mounted on pneumatictires, the out-. riggers prevent swaying and allow lateral mo tion, as referred to.

The appliance, as described above, is not nec-. essarily limited and restricted to the precis features of structure since these may be modified within reasonable limits without digression from the nature and principle of the invention, as de fined in the appended claims, and without loss ofl any of the material benefits or advantages accruing from the employment of the invention in physical form.

I claim:

1. In a load-lifting apparatus including a base,

a load-lifting carriage, a pair of transverselyregistered carriage-operating pantograph-linkages between said base and carriage and means to actuate said linkages simultaneously, the novel improvement of said actuating-means including a bell-crank hinged on said base, main hydraulic operating-means connected to the shorter arm of the bell-crank, a link connecting the longer arm of said bell-crank t0 the lower pairs of links of the two linkages, and a booster hydraulic means mounted on the longer arm of said bell-crank and adapted to cooperate with said linkages to assist in raising them dining the initial portion only of the lifting operation of said main hydraulic means.

2. The novel improvement set forth in claim 1, I including the additional novel improvement that said booster hydraulic means is hinged on the longer arm of said bell-crank and said linkages have means cooperating with said booster hydraulic means and rocking the latter dining at least a portion of the active operation thereof.

wnnaua. Ross.

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