US3078941A

US3078941A - Propulsion device of the walker type

Info

Publication number: US3078941A
Application number: US156059A
Authority: US
Inventors: George B Baron; Edwin W Sankey
Original assignee: Universal Marion Corp
Current assignee: Universal Marion Corp
Priority date: 1961-11-30
Filing date: 1961-11-30
Publication date: 1963-02-26
Anticipated expiration: 1980-02-26
Also published as: GB972744A; DE1291218B

Description

Feb. 26, 1963 Filed Nov. 30, 1961 G. B. BARON ETAL PROPULSION DEVICE OF THE WALKER TYPE 3 Sheets-Sheet l INVENTORS Feb. 26, 1963 a. B. BARON ETAL PROPULSION DEVICE OF THE WALKER TYPE Filed Nov. 30, 1961 5 Sheets-Sheet 2 ATTORNEYS Feb. 26, 1963 G. B. BARON ETAL PROPULSION DEVICE OF THE WALKER TYPE 3 Sheets-Sheet 3 Filed Nov. 30, 1961 INVENTORS fieazye 3. 121mm 5 I [09/4110 1/. Jamie BY I WM 5 ATTORNEYS United States Patent 3,078,941 FROPULSION DEVICE 8F THE WALKER TYPE George B. Baron and Edwin W. Sankey, Marion, Ohio, as'signors to Universal Marion (Iorporation, Marion, Ohio, a corporation of Florida Filed Nov. 38, 1961, Ser. No. 156,35?

6 Claims. (Cl. 136-43) This invention relates to propulsion devices specially adapted for use with heavy equipment, and particularly to propulsion devices of the walker type.

The general object of the present invention is to prtr vide a propulsion means of the walker type which will be an improvement over those previously suggested.

A more specific object is the provision of mechanism of this type which is capable of infinite adjustment to vary the shape and inclination of the orbital path defined by the connection between the mechanism and tread during operation.

A further object is to provide a walker which will supply the necessary motion to the tread members without need for slides, towers, etc.

Other objects of the invention will become apparent from the following description of one practical embodie ment thereof, when taken in conjunction with the drawings which accompany, and form part of, this specification.

In the drawings:

FIGURE 1 is a side elevation of a piece of heavy equipment provided with the propulsion device of the resent invention;

FIGURE 2 is a perspective view of the operating mechanism at one side of the equipment, illustrating a portion of the drive for the mechanism and a portion of a tread carried by the mechanism;

FIGURES 3 and 4 show the mechanism in side elevation in two positions in its cycle of operation; and

FIGURES 5 to 7 show diagrammatically variations of the mechanism setting out the orbital movement paths obtained thereby.

In general, the invention contemplates providing a walker propulsion mechanism for heavy equipment which will have a double eccentric, or crank, drive means, with a pair of links interconnecting the eccentrics, or cranks, and the tread member, to divide the load of the equipment between two drive shafts.

Referring to the drawings in detail, the propulsion de vice is shown, for purpose of illustration, mounted upon a dragline excavator 1, which includes a platform 2 supporting the body portion 3 and pivotally mounted upon a circular base 4. The excavator is not shown in detail, and parts are broken away, but it has the usual boom 5 by which the drag bucket (not shown) is carried in a conventional manner. The boom is mounted at the rear of the platform, and the machine is designed to be moved normally in the opposite direction.

Treads 6 are located at opposite sides of the machine for contact with the ground at opposite sides of the circular base. The treads are connected by

links

7 and 8 with drive shafts 9 and 10 mounted upon the platform. Only one tread and its drive have been shown, but it will be understood that this mechanism is duplicated on the opposite side of the platform as in the mentioned previous patents.

Drive shafts 9 and 10 extend transversely of the platform and are supported in suitable bearings 11 and 12. The shafts are relatively short, and carry spur gears 13 and 14, respectively, at their inner ends. These gears mesh with a gear 15 mounted on the end of a principal drive shaft 16, supported in appropriate bear- 3,078,941 Patented Feb. 26, 1963 ings (not shown) and driven from a suitable power source (not shown) carried on the platform.

All of the above structure, with the exception of

links

7 and 8, is completely shown in the patent to Busick et al., No. 2,541,496, and that patent can be referred to for the structural details which have been omitted here to simplify the present disclosure.

As can be seen particularly well in FIGURE 2, the

links

7 and 8 have their upper ends journalled, respectively, on the crank pins 17 and 18 of the

cranks

19 and 20, fixed to the ends of drive shafts 9 and 10. The lower ends of the links are mounted upon a pivot pin 21 transversely bridging a yoke 22. In order for the two links to be positioned and operate in the same vertical plane for balance, and to equalize the load upon pivot pin 21, one of the links, as shown the link 8, may be bifurcated at its lower end so that it will straddle the lower end of link 7. Yoke 22, in turn, has coaxial trunnions 23 projecting fro-m its ends, with their com.- mon axis lying normal to the axis of pivot pin 21. Trunn-ions 23 are rotatably mounted in ears 24 upstanding from the tread 6. This mounting permits universal movement to the tread 6, so that the tread is free to adapt its position to ground contour each time the tread is placed upon the ground.

It'will be evident that with the above described linkage between the drive shafts 9 and 10 and the tread, the tread will be lifted each rotation of the drive shafts, moved forward and again moved down into ground contact. When the tread rests upon the ground, the remaining cycle of rotation of the cranks will result in pivotal movement of the cranks about the crank pins 17 and 18 and movement bodily of the drive shafts 9 and 10, upwardly and forwardly, to move the machine in a forward direction.

When cranks of the same length are employed and the cranks are arranged on their respective drive shafts so as to lie parallel to one another, the movement described by pivot pin 21 in lifting and moving forward the tread will be a semi-circle. Similarly, the movement of the machine as it is raised and moved forward as the cranks pivot about the crank pins 17 and 18 will be semi-circular.

The orbital path of movement of the pivot pin 21 can be changed considerably to increase the vertical lift or the horizontal step length, as desired, by advancing one crank relative to the other, by using cranks of different lengths, by using links of difierent length, by changing the spacing between cranks or the relative elevations of the cranks, or combination of these variations. In the illustrated embodiment, the rear crank has been advanced in the direction of crank rotation over the forward one. This will materially increase the forward movement of the machine each cycle of shaft rotation. As shown in the diagram of FIGURE 6, the plotted path of the pivot pin is generally elliptical with its long axis extending horizontally. This not only increases the forward length of the step ta-ken each cycle, but reduces the height the machine need be lifted from the ground.

The benefit of lengthened step can be retained, and the long axis of the elliptical plotted path can be angularly adjusted by changing the lengths of the respective cranks. For example, FIGURE 7 illustrates an arrangement wherein the forward crank is larger than the rear one, and the rear crank is advanced 45 relative to the forward one. This produces a fiat orbit having a longitudinal axis which is inclined forwardly. With this structure, the tread and the machine will each move forward in a trajectory which will progressively rise during a major portion of the forward motion, and lower at the end of the step.

which provides all of the advantages of prior structures,

and, at the same time, eliminates the need for slides or towers to obtain the proper tread advancing movement.

While in the above one practical embodiment of the invention has been disclosed, it will be understood that the details of structure shown and described are merely by way of illustration and the invention may take other forms within the scope of the appended claims.

What is claimed is:

1. A propulsion device of the walker type for heavy equipment having a platform and a power source on the platform comprising, a pair of parallel drive shafts mounted transversely of the platform at one side of the platform and operatively connected to the power source for simultaneous rotation at the same speed, means carried by the shafts radially removed from the axes of the respective shafts to provide eccentric driving members, a tread at the side of the platform extending longitudinally of the platform, and a pair of links each pivoted at one end to the tread, one link of the pair of links having its opposite end journalled on the eccentric driving member of one shaft of the pair of shafts and the other link of the pair of links having its opposite end journalled on the eccentric driving member of the other shaft of the pair of shafts.

2. A propulsion device of the walker type as claimed in claim 1 wherein one of the eccentric driving members is advanced in the direction of shaft rotation relative to the other eccentric driving member.

3. A propulsion device of the walker type as claimed in claim 1 wherein the eccentric driving members are cranks.

4. A propulsion device of the walker type as claimed in claim 1 wherein, the eccentric driving member of one shaft of the pair of shafts isspaced a greater radial distance from the axis of the shaft that carries it than the radial spacing of the other eccentric driving member from the axis of the shaft that carries it.

5. A propulsion device of the walker type for heavy equipment having a platform and a power source on the platform comprising, a principal drive shaft mounted transversely of the platform and operatively connected to the power source, a pair of parallel drive shafts mounted on the platform at each side of the platform,

means interconnecting the principal drive shaft and the pairs of parallel drive shafts to rotate each shaft of the pairs of shafts at the same speed in the same direc- =tion, means carried by each shaft of the pairs of shafts radially removed from the axes of the shafts that carry them to provide eccentric driving members, a tread member at each side of the platform extending longitudinally of the platform, and a pair of links pivotally connected at one end to each tread member, the links of each pair having their opposite ends journalled to the eccentric driving members of the pair of drive shafts at the same side of the platform as the tread member to which the respective links are connected.

6. A propulsion device of the walker type as claimed in claim 5 wherein, the eccentric driving members are cranks.

References Cited in the file of this patent UNITED STATES PATENTS