US2471901A - Load-lifting appliance - Google Patents

Description

W. A. ROSS May 31, 1949.

LOAD-LIFTING APPLIANCE 2 Sheets-Sheet 1 Filed April 25, 1945 y 1, 1949. 1 w. A. ROSS 2,471,901

LOAD-LIFTING APPLIANCE Filed April 25, 1945 2 Sheets-Sheet 2 Patented May 31, 1949 LOAD-LIFTING APPLIANCE William A. Boss, Springfield, 111.,

assignor to Weaver Manufacturing Company, Springfield, 111., a corporation of Illinois Application April 25, 1945, Serial No. 590,291

3 Claims.

This invention concerns certain novel structural and functional features in load-lifting appliances, whereby to provide improved constructions involvingmore excellent operative properties as to efficiency and effectiveness, which desirable characteristics will become apparent from the following detailed description of a present preferred embodiment of the invention, fully illustrated in the accompanying drawings, forming a part. of this specification and to which reference should be had, and throughout the views of which, for the sake of simplicity, like reference numerals have beenemployed to designate the same structural elements or parts.

Among the various objects of this invention may be mentioned the provision of a portable load-lifting device capable of raising a load between very low and very high levels and having a wide range of lift in proportion to its lowest or collapsed height, one of such constructions having a collapsed height of sixteen inches and capable of raising a load to a maximum level of eighty-four inches.

Another aim of the invention is to so arrange the lifting element that either end of a substantially long load carrying carriage can be raised or lowered independently of the opposite end.

A further design of the invention is to provide a means of moving the load carrying carriage and thus the load a substantial amount to either side of its normal central position.

In these drawings:

Figure 1 is a sid representation of the new and improved lifting apparatus with the loadelevating saddle or carriage in raised position;

Figure 2 is a similar view with the carriage or saddle in its lowermost relation;

Figure 3 is a plan view of the structure; and

Figure 4 is a fragmentary cross-section on line 4-401" Figure 1. I

By reference to these drawings, it will be perceived that the novel device includes a metal chassis or base-frame I I mounted on four carrying-wheels I2, I2 and I3, I3, the former being manually steerable by an appropriate pulling handle I4 and suitable connecting operating means 55 (Figure 3).

Twin or duplicate, transversely-registered, four-link pantograph-mechanisms, characterized as a whole It, It, are mounted on the front portion of the chassis-frame, and a pair of similar, analogous or comparable four-link linkages H, H are carried by the rear portion of the chassis.

Each of these two side-mechanisms, in lateral register with one another, includes a one-half 2 length link I8, and a full length link I9, hinged together at the middle point 23 of the latter link which at its lower end is rockingly mounted at 22 on the corresponding chassis side-bar.

The upper end of each of the two links I9 is hinged at 2o to the lower end of an upper link 24 of thesame length pivotally connected at its top end at 25 to the side of the forward portion of an appropriately shaped and formed loadcarriage 26 which may be of any suitable design, depending upon the type of load which it is to support and elevate, another 1ink2'l, onehalf the length of element 24, being hinged to the center of each of the latter at 28 and at 29 to the upper end of the corresponding link I8, all as is most clearly depicted in Figure 1.

The parts of these two laterally-registered linkages are cross-connected together at various points by metal-rods SI, 32, 33 and 315 welded at their opposite ends to the inner faces of the links.

The rear actuating or operating mechanism is of substantially the same form, but of reversed construction, its elements being supplied with the same reference numerals as those employed above supplemented by loll, the material difference between the forward and back structures residing in the fact that each link II 8 is of full length and it is supplied with a roller I35 disposed and arranged to travel lengthwise the chassis in a straight, guiding, channel-member I36 mounted fixedly on the inner surface of the corresponding side-bar of the chassis.

Rod 3|, uniting the twin-links I9, has fixed thereto a pair of parallel, laterally-outstanding arms 4I between and to which, at 42, is hinged or pivoted the end of a piston-rod 43 whose piston, not shown, is reciprocatory in an elongated cylinder 44 hinged at its lower end at 45 on a crossmember of the chassis, the interior of the lower end portion of such cylinder being connected by a flexible pipe or conduit 46 to a hand-operated oil-pump 47 of known construction at the forward end of the appliance which receives its oil from a supply tank or receptacle 48, such conduit 46 being also joined to the interior of an upright, auxiliary or supplemental, booster cylinder 49 fixedly mounted on the chassis in the center, longitudinal, vertical plane thereof and having a piston, not shown, and its upstanding piston-rod 5| with an enlarged flat head or end.

The rear linkage for the carriage has a comparable hydraulic operating means supplied with like reference numerals plus I 00.

As will be readily understood, the principal lift-

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