US2491064A - Walking tractor - Google Patents

Description

- Attorney w. E. URSGHEL WALKING TRACTQRl 3 Shets-Sheet 1 `Filed June 26,- 1945 WALKING- f 'rRAcToR Filed June 26, 1945' Dec. 13, 1949 w. URSCHEL 2,491,064

WALKING TRACTQR' 3 Sheets-Sheet 3 Filed June 26. 194151 554g@- y '77 a @wfg Patented Dec. 13, 1949 WALKING TRACTOR .vvilliamfE.lll1fschiel, Valparaiso, f-Ind.; Jue B. Urschel administrator of sad""Willam E.

Urschel, deceased 2 Claims.

`My, invention'relates-to improvements in walking tractors andit more especially. consists; of the features pointed routin the'lfollowmg descripl tion.

`accumulation-,of earth; that provides a duplication of'poperating parts-onthe left handand .right hand side of the machine; that employsa difvferential power drivebetweenA the two duplicate cams, rightuand left, on the machineyand that it has a ,separate control `for each sidetsoY that thepowercan be applied to` either side alone, thus facilitating Athe turning', vof the tractor .within a very short radius;y andfthat encloses all the, power mechanism and connectedcamsin a..cas1ng,.to

.protect it.

With vthese and other related endsin view I illustrate on the accompanyingdrawingssuchinstances y of f adaptation VVasy will disclose the broad cooper-atingieatures of the mechanismwithout limiting" myself to :theaspecic details. shown thereon and described herein.

Fig. 1 is a side elevation ofthe machine. Fig.,2,isV atop plan View of Fig. 1. Parts are shown in section.

Fig. 3 is a-top plan View of the frame Aof the machineA in assembled relationV only with the main ,parts v Fig. 4 is an enlargedsplan of the cam portion of theentire machinerpartly in. section.

,l Fig. 571s an enlarged View of the` double roller cam follower, inlsection.

Fig. 6 isan enlarged.. diagrammatic view lillustrating the cylclev ofv operationlof the `camsand associated legs.

Fig. 7 is atop `plans-viewer amechan-icallyconnected -front and rear foot of. the .tread `portion of the machine.

Fig. 8 is a side elevation of the control forthe differential drive.

Fig. 9 is a partial perspective*view.of.,the leg structure for different forms of legs.

Fig. 9a is an elevation of amodication ofthe leg 2B shown on Fig. 9.

In practicing my invention I may uselwhatever modifications of the `structurefor alternatives of function that the exigencies of. varying conditions may demand without departing from the broad spirit of the invention.

In contrast to so called Steppers` and conven tional endless tread tractors this invention includes a pair of front and rear feet on each-side f2 of themachine whichv are duplicates ofseach other. --Infoperationat no time `is-,apairof-ffeet ,entirelyoffromthe ground., As a foot is being` .raised anotherv neighboring foot -has .justen- :gagedlthe ground.

To control the movement of the legs and-connected feet two duplicate cam groups are provided each grouphaving ,an outside. duplicate cam and an inside duplicate cam.

Both of the outside camsI control the up and downl movement ofyalll the 1legssand connected feet, and both ofthe insidecams controlt-he to and fro movement of` alle ,the-legsand their connected pfeetto cause, the; machine to travel v.over the ground.

,Theinside cams `are -madeheavier because they havethe heaviest workrto doin moving the machine forward.,-While sonrie-,of` the -feet areinengagement with the ground andaare fstanding still.

The'up and down movement of some ofthe legs vandieet at the-beginning and at they end of each l IThis enablesA 1the operator to entirely stop lor variablymodiiythe movementof all the legsand feet ononelside ofthe machine from the legs and feeton the other sideso asto permit a sharp turningof themachineto the right or left.

A detailedidescription of the machine follows:

The frame l about midway` andtransverse of its length .has a stationaryshaft 5 I`on. which .the sleeve portion 5i integral with camsVSll-B'l and the diierential 39 are mounted. At v,each ,endof the frame .andtransverse thereof there isadisconnected rock shaft 9. Parallel4 rto the shaft. 9 thereisa duplicate rockt-shafted `These shafts have 4their-` abutting .ends 'l Lin` bearings 3 located centrally crosswise l,of. the, frame. Atthe ends of these shafts thereare cranks which actuate the up and down movement of the feet andtheir attached legs.

A central member 'l extends rearwardlyvfrom the engineY base to the rear Hedge -ofthe iframe to-provide rigidity. Onit "bearings 3,l 54 and are located. The center member 1 is joined to the sides of the frame by transverse members 6. Between bearings 54 and 58 the member 1 is divided into two parts, see Fig. 3.

The sides of the frame I have lateral bosses 2, 49 and 5U that form pivot points for separate rock arms (Fig. 2), which arms are joined by links that connect them to the respective cams 34-31.

An imaginary horizontal line 19 in Fig. 6 represents the extent of actual ground traverse of a shoe I6 or I9. A second imaginary line 18 represents the raised and reverse traverse of a shoe. The lines 18 and 19 are joined by two reverse curves 80.

I plot the contour and extent of the required radii of the cam roller positions. The center of lines 18 and 19 is taken as a starting point on the ground The entire length of these two lines and their connected curved ends 88 are divided arbitrarily into twelve distinct steps or positions consecutively numbered up to twelvef parts as shown in Fig. 6. These positions are projected back through the connected levers, links, etc., to the cams where corresponding radii positions are located. From these the changing contour of the cam grooves is determined and the variations of the radii corresponding to the related points of the positions of a foot is established.

In Fig. 6 the No. l position is at the center of the ground line 19. This position is also identified at 1 on the cam diagram, Fig. 6. This portion of the entire perimeter of the cam groove is the position of an actuating cam roller 63 or 64 corresponding to l on the ground line 19. The other roller positions on the cam grooves are similarly located from the other points on the lines 18-80.

The mechanism on one side of the tractor is a duplicate of the cooperating mechanism on the other side. For simplicity the description is now conned to the single pair of front 22 and rear legs 23 on the left side of the machine (Figs. 1 and 2). Immediately adjacent these outside legs 22, 23 there is a duplicate pair of inside legs 26, 21 positioned next to the frame I.

There are two rigidly formed cams 34--31 forming one group to the left of the center, lengthwise of the machine, facing from the front. A duplicate cam group is positioned to the right of that center line and in axial alignment with the other cam group. On the inside of each cam group there is the cam 34, 35 which serves to control the to and fro movement of both pairs of legs 22 and 26. On the outside of each cam group there is the cam 36, 31 which only controls the up and down movement of the feet.

At the upper end of each of the legs 22, 23, 26, and 21 (Fig. l) there are outside cranks 24, 25, '28 and 29 which simulate the thigh portion of the human anatomy. These are attached to the outer ends of the two-part rock shafts 8 and 9. On the inside of the frame there are duplicate cranks 39 and 3|. The cranks 36 are on rock shafts 8 and 9, and the cranks 3| are on rock shafts 9 and 8.

On the outside of the frame, right and left, the bosses 2 serve for the rock shafts 8 and 9. The inside bosses 49 are extended on the outside of the frame and serve as a bearing for the spindles 45 and the bosses 50 serve for the spindles 41.

The free ends of the cranks 3| are connected by a link 32 at 14 and the free ends of the cranks 3U are similarly connected at 14 by links 33. The links 32 are also connected to the free end 61 of the cam roller rock arm 56 and the links 33 are similarly connected at 61 to the upper rock arm 56 (Fig. 2). The links 32 and 33 coact with the outside cam 36, 31 to produce the up and down movement of the legs and feet. The links 4|, 43, 52 and 53 are connected to the inside cam roller carrying rock arms 56 to produce a to and iro movement of the legs. They are acted upon by the inside cam 34, 35. There are eight of these cam roller carrying rock arms duplicates of each other, four on the right and four on the left and they all bear the same reference numeral, viz., 56.

The spindles 41 are connected to rock arms 44 and 48 and the rock arms 44 are connected by links 43 to the inside legs 26 at 68. The rock arms 42 on spindles 45 and the rock arms 46 are connected by links 52 to the lower cam roller rock arms under the control of the inside cam 34, 35. The inside rock arms 48 are supported on spindles 41 in the bosses 58.

The inside cam roller rock arm 56, the lower one, is pivoted on a spindle 51 positioned in the bearing 54. It is connected to the link 52 and the upper link 53 is pivoted to the rock arm 48 at 14. All the pivot points of the ends of the links 32, 33, and 53 are designated by the numeral 14 and all the pivot points on such links for the cam roller rock arms are designated by the numeral 61.

A single roller and attached connections from a given cam will perform one of the leg functions of the outside group of the front and rear legs and the cam roller diametrically opposite, on the same cam, at degrees, will perform the same function for the adjacent and inside group of a front and a rear leg.

In order to avoid the complications of conventional parallelogram movements between the front and rear legs and their feet, I form the front and rear feet as a part of a rigid connecting link such as I8 and 2| connected respectivef ly to the feet- I6, I1 and I9 and 28. These feet are pivoted to the lower end of the legs at 15. These connected feet are shown as a detached member on Fig. '1. This construction insures that the feet will remain flat during their entire cycle of movement. If desired the shoes 11 of rubber may be vulcanized to the respective metal feet and the feet may be made removable from the legs so as to be replaced by different sizes to accommodate the machine to terrain that is more or less soft and soggy and if desired additional feet or shoes may be provided between the front and rear legs by stiiening the links I8 and 2| and placing attachable and detachable feet thereon.

In practically constructing the machine for actual heavy duty operation I may make the legs 22, 23, '26 and 21 of rectangular cross section or of round cross section 69 shown in Fig. 9a. When formed of round cross section the structure would be tubular to save weight.

The legs 22, 25, 23 and 21 are pivoted at their upper end at 13 to their respective cranks 24, 25, 28 and 29. The stationary shaft 5 is supported in bosses 4 on the inner face of the frame.

To protect the working parts of the machine an upper cover I I encloses the engine I8 and with an underneath cover I2 secured to the frame forms an oil tight compartment. The lower casing has a drain outlet 16. A seat I3, Fig. 1, is for the operator and a transmission lever I4 gives him control over the engine movement and a pair of differential levers l5, see Figs. 2 and 8, control the progress of the tractor. These hand levers may have the usual rachet segment and interacting spring pressed teeth. They are pivoted to the engine support and a link 1l connects each lever to one of the differential brake disks 38 (Fig. 3) by means of a band 10 (Fig. 8).

The differential gear 39 is connected by a pinion 40 which in turn is connected by two bevel gears to the engine shaft. If the operator wishes to turn the machine to the right he pulls the right hand lever I5. This action, through the diierential will stop the articulated legs on the right hand side of the machine or if the lever l is not pulled to its maximum extent the right hand legs in their movement will be only partially stopped. By this control the machine can be readily and quickly turned to the right or left as desired. When a left turn is intended the left hand control lever l5 will be used in the same way (Fig. 2)

The cam roller rock arms 54 are pivoted on a spindle 51 positioned in the bearing 58. A similar short spindle 51 forms a pivot for the other roller bearing rock arm 56 (Figs. 1 and 2).

In order to avoid a reversal ofrotation of the cam rollers 63 and 64 I form them of different diameters. These rollers are supported by threaded pins 59 (Fig. 5) which have two diierent diameters 60 and 6I. On these diameters needle rollers 65 are held in place by roller cages 66. In this construction, Figs. 4 and 5, on one set of pins 59`the large cam internal ring 34 and the smaller diameter rollers 63 roll on the external cam ring 35. This construction leaves a clearance 62 adjacent the roller 63. It insures that the rollers 63 and 64 do not reverse their rotation during the revolution of the cams. In contrast, on the cam 36, 31 the small roller 63 engages the internal cam 36 and the larger roller 64 engages the external cam 31, Fig. 4.

What I claim is:

1. In a walking tractor, a supporting frame, a source of power on the frame, a plurality of interconnected pairs of front and rear legs on each side of the frame, a separate compound cam unit for each pair of legs, each cam unit having two bearing faces, a diierential drive from the source of power positioned between the cam units, one bearing face of a cam serving to control the up and down movements of both pairs of legs, and the other face of said cam serving to control the to and fro movements of both pairs of legs.

2. In a walking tractor, a supporting frame, separately connected to a source of power on the frame, a pair of separate front legs a pair of separate rear legs pivoted to the frame at each side thereof, a pair of links at each side respectively connecting a corresponding front and rear leg together, means for coordinating movements of the separate pairs of legs independently of each other to maintain a walking pace of all the legs in related steps, said means composing a pair of separate compound cams on each side of the tractor for controlling all the movements of the legs.

WILLIAM E. URSCI-IEL.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 916,702 Hartt Mar. 30, 1909 1,266,774 Delo May 21, 1918 1,309,053 Adams July 8, 1919 1,382,854 Rasmussen June 28, 1921 1,500,723 Roy July 8, 1924 1,560,325 Roy Nov. 3, 1925 1,691,233 Ehrlich Nov. 13, 1928 1,798,104 Palmer Mar. 24, 1931 FOREIGN PATENTS Number Country Date 560,657 France July 16, 1923

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