US2733950A - Attor ey - Google Patents

Description

Feb. 7, 1956 L. H. JANZER ETAL 2,733,950

STAKE GRAPPLING AND PULLING MACHINE Filed Sept. 10, 1953 2 Sheets-Sheet 1 IN V EN TORS Feb. 7, 1956 H. JANZER ET AL STAKE GRAPPLING AND PULLING MACHINE 2 Sheets-Sheet 2 Filed Sept. 10, 1955 fllm United States Patent 0 STAKE GRAPPLING AND PULLING MACHINE Lorin H. Janzer and Loyd R. Harriman, Bowling Green,

Ohio, assignors to Urschel Engineering Qompan Bowling Green, Ohio, a corporation of Ohio Application September 10, 1953, Serial No. 379,402

9 Claims. (Cl. 294-88) Our invention has to do with grappling and pulling objects from the embrace of a holding body. The invention essentially relates to grappling equipment by which an object may be drawn from such embracement.

More particularly, our invention concerns a machine for seizing an exposed end of an earth bound stake, such as those used to hold a road building side form in screeding position, and for pulling such seized stake from the ground to free the form.

Those familiar with road building know that, in road construction using concrete or other similarly bound ag gregates, it is common practice to pour the aggregate, before it becomes set, on the road bed between spaced parallel and generally vertically extending side forms. These side forms are usually metal lineal sections of about ten foot lengths. They are laid end to end in successive abutting relation to form curbs on each side of the road strip to be poured. The upper edges of the forms provide a gauge for finish screeding the aggregate following pouring. Often times, this upper edge is turned upon itself to also provide a rail-like flange over which pouring and finishing equipment sometimes track, in the road laying operation.

In order that these forms may be used repeatedly for successive pourings on the same or different road constructions, the forms are not only made in the described sectional lengths but they are also prepared for easy removal after the aggregate has set or cured. It is necessary, however, before the form sections can be moved, to draw the stakes with which they were held during the road pouring and finishing.

The stakes holding the form sections are, of the necessity of being capable to hold the forms from movement when equipment tracks over them or the aggregate courses are poured or applied against them, usually made from metail rod or dowel stock driven well into the road bed. These stakes, as a consequence, become earth bound and most difiicult to remove. The difiiculty of their removal is enhanced by the need, if clearance for road building equipment to ride the forms is to be had, to drive the stacks so that only a short stub end of each extends exposed above ground. Such short ends present the only part available to seizure or for working, in attempting to release the stakes.

Also, the very nature of the stakes, without heads as in spikes and with only smooth lateral surfaces to grip, makes seizure still more difficult. In addition, the presence of the road forms, with their bracing flanges and parts limit the freedom one might use to maul or pry the stakes free.

The removal of these stakes, prefacing as it does the freeing of the side forms sections for reuse and being the task that it is, has often required the contractor to purchase and maintain a considerably larger stock of side forms, if he desires to effect continuous pouring, than would be necessary were the forms to be readily freeable. In addition, the freeing of stakes absorbs nonroad producing labor, increasing the burden costs of road "ice building. Ways and equipment have long been sought to eliminate this troublesome problem. Some of these have been adaptations of spike pulling equipment like that shown in United States Patents No. 1,771,712; 1,893,719 and 1,908,299, while others have utilized variations of hand pulling tools like those shown in United States Patents Nos. 523,181; 616,207; 649,873 and 842,185.

In designing the nail puller shown in United States Patent No. 2,570,914, the patentee there made what appears to be the first attempt to solve the problem of preventing grappling jaws from moving axially away from an element to be drawn as the jaws close laterally thereon. However, the construction shown there deals only with a headed nail, as distinct from a smooth ended stake. Hence, closure of the jaws in nail-pulling is sufficient if the jaw ends or beaks take positions behind the nail head, as distinct from seizure on the smooth shank.

Our invention therefore has for its prime purpose to provide stake engaging and pulling jaws which, in closing laterally on the stake, move axially toward the stake end and on pulling exert further tendency to close. Thus, embodiments of our invention obtain good purchase and seizure on the stake and upon application of a pulling force to the jaws will quickly draw the stake.

In addition, our invention has for an object to provide portable power actuated stake pulling equipment. By reason of such provision, not only may the power-needed to exert stake pulling be motor generated but the mass and bulk of the pulling equipment and power generator may be easily conveyed from place to place and from stake to stake.

Related to the just mentioned objective, our invention also has for a purpose to provide a wheeled truck upon which the stake seizing and pulling equipment and actuating power generator and converter are all mounted. A particular object in this connection is to provide a truck having a triangular frame, on three wheels, with certain of its wheels, preferably two in line, in riding contact with the side forms and substantially in vertical plane with the stake pulling equipment. By this arrange ment, equipment embodying our invention can be used soon after pouring, without injury to the curing aggregate because the forces of stake drawing are transmitted through the wheels and forms to the road bed, as distinct from being applied to the then curing aggregate.

A further particular object appertaining to the truck of our invention is to provide means operative, without supervision of the equipment operator, when once rendered effective, to assure that the two mentioned wheels ride the side forms and that the truck remains in constant line relative to the roadway and forms as the truck is moved progressively to each undrawn stake.

Our invention has for a still further object to provide advantageous structures and arrangements which will appear from an examination of the following description and the accompanying drawings. In the description which follows, we describe completely a specific embodiment of the invention in the best mode now contemplated by us for carrying out our invention and, in addition, we outline the manner and process of making and using the same. The accompanying drawings show such embodiment and, by reference to the description, illustrate details and relations mentioned therein.

Fig. 1 of the accompanying drawings show, in perspective view, stake grappling and pulling equipment embodying our invention, in position at Work on a roadway. Fig. 2 illustrates an end view, in elevation, of the equipment shown in Fig. 1. Fig. 3 illustrates a plan view of one of the cantable wheels provided on the equipment shown in Fig. 1. Fig, 4 illustrates a front, somewhat enlarged, view of the stake grappling and pulling chuck which forms part of the equipment shown in Fig. 1. Fig. illustrates a side view of the chuck shown in Fig. 4. Fig. 6 illustrates view of a section taken along the plane of the line 66 indicated in Fig. 4. Fig. 7 illustrates, a side form in common use which differs somewhat from that shown in Fig. 1 but which presents equal difiiculty to the removal of stakes. Fig. 8 illustrates one of the jaw cranks.

The stake grappling and pulling machine which illustrates the best mode of an embodiment of our invention now known to us includes a wheel supported truck, indicated generally 10, on which power generator elements, indicated generally 11, and power converters, indicated generally 12, are mounted. Connected to the power converto'rs is a stake grappler and puller, indicated generally 14.

The wheel supported truck 10 has a frame 21. The traine21inplt1n is preferably of a basic triangular outline. It has a pair of L beams 22 and 23 of equal length forming the base leg of the triangular outline. The -L beams are joined together, 'as by welding, so that their narrow flanges 24 engage and overlay each other throughout their lengths and their 'wide -fianges 25 depend therefrom in facing -spac'ed parallel relation forming a somewhat shrouded chamber 26 between the flanges 25. The frame also has two pairs 0f angle iron struts '27 and 28. The struts of the lpair27 are of equal length and having their ends connected, as bywelding, with points "on the narrow flange 24 of the L beam '23 on opposite sides and equally spaced from the lineal center of the L beam 23. From their connection with the "L beam 23 the struts extend parallel to each other and at right angles to the L beams 22 and '23 to points on one side of and spaced from said L beams. The struts of the pair 28 each have one of their ends connected, as by Welding, to points of the narrow flange 24 of L beam 23 near opposite ends of said Lbearn. Each strut o'f'th'e pair 28 extends inc'linedly to :the "L beam from said point of connection therewith toward the free ends of the pair of struts 27. The free ends of the "struts *o'fbothpairs 27 "and 28 are joined by a spider 29 'of rectangular outline whose longer sides 30 parallel the "L beams and are spaced therefrom, for reasons and advantages becoming later apparent. Supported on the spider 29 is a housing 31 for enclosing the power generator elements 11 to be later described.

The frame 21 rides 'on wheels. In the construction described herein, there are three wheels used, 'one 35 of which preferably has "a rubber and pneumatically inflated tire. The other pair of wheels 36 have flat metal rims.

The-wheel 35 runs free on a stub shaft 37 supported on th'e'pair of struts'27. Preferably, I provide 'ap'air of plates 39 which extend in spaced parallel relation to each other between and downwardly from the struts .27, at points below but inwardly on center for the spider '29. Each t plate 39 has an opening (not shown) axially aligned with a corresponding 'opeiiin'gin the other plate and providing journal bearing support forthe stub "shaft 37, in a mannerc'omm'on to the art. The ends of the stub shaft are threaded and receive a nut '40 thereon to lock the shaft in an installed relation in'theplates as. The rubber tired wheel 35 rides theportio'ns of road spaced inwardly from edgefantl nearer the 'center. 'The provision of said rubber tired rim on wheel 35 becomes advantageous in moving the equipment over the roadway from one stake pulling po'sitionto the other, particularly in a period soon after the 'road formingaggregate has been first poured.

The other wheels 36 are preferably mounted in line near opposite ends of the paired L beams 22 and 23 and in the "chamber 26 between the wide flanges 25 thereof. Each Wheel 36 is similarly mounted'so it should sutlice to describe only one, with the detail that is duplicated in the other.

Each wheel '36 runs free un a stub shaft 42. One end of the stub shaft 42extends through a journal opening 43 in the wide flange 25 of the L beam 23. This end of the stub shaft 42 receives a washer and is threaded to receive and has a nut 44. threadably mounted thereon. The other end of the stub shaft 42 extends through a bushing 45. The bushing 45 has a cylindrical outer surface 46 and an inner journal cylindrical surface 47. The inner surface 47 is eccentric to the outer surface 46 of the bushing 45. It is on this inner cylindrical surface 47 that the said other end of the stub shaft 42 journals in extending through the bushing 45. The outermost portion of said other end of the stub shaft 42, like its opposite, also has a washer and nut 49 threadably mounted thereon. The bushing 45 is mounted in the wide flange 25 of the other L beam '22.

The L beam 22 has a circular opening 50 in its wide flange 25 of a greater diameter than opening 43 in L beam 23. The opening 50, while cross registering with opening 43, is eccentric thereto along a line radial to the opening 43 and extending parallel to the lineal extension of said L beams. The opening 50, however, exactly fits and forms a journal bearing for the bushing 45 and engages the outer surface 46 thereof. Preferably, the bushing has a handle 52 extending radially to the axis of the outer cylindrical surface 46. When the handle 52 is moved angularly about an axis corresponding to that of said outer surface 46, the bushing-45 rotates in the opening 50. As the bushing is thus rotated, the relation, eccentric-wise, between the inner surface 47 of the bushing 45 in L beam 22 and the opening 43 in the L beam 23 changes between two relative positrons.

In one position, shown in Fig. 3 of the accompanying drawing, the handle '52 points in a direction paralleling the L beams and toward one end thereof. When in that position, the bushing-45 and opening 50 in-rela'tionto the inner bushing surface 47 and the opening 43 serve to cant the stub shaft 42 in relation to the wide flanges '25 of the -'L beams. The described canting of the stub shaft 42 causes the wheel 36 to toe-in toward the flange 25 of the inner L beam 23. Now,'when the truck 10 moves in the direction indicated by arrow 55 in Fig. 3, the truck tends to move toward the road center and away from the side of the road.

The other position, to which rotation of the bushing 45 will place the stub shaft 42 and wheel 36, is a reverse one to that shown in Fig. 3 of the accompanying drawings. In that other position, the handle 52 points in the direction opposite to that towards which .the arrow 55 points in Fig. 3 and the stub shaft 42 will then be canted inward toward the flange "25*0'f L beam 23 "in the opposite direction. As before, the c'anting of the stub shaft 42 will cause wheel '36 ,to toe-in. Now, when the truck is moved in a direction opposite 'to that indicated by the arrow 55 '(Fig. 3) the truck 1'0te'nds to move to- Ward the road center away "from the road side. 'By having the "thus rotatable bushings '45 to adjustably' caut the wheels 36, the truck may be easily adjusted for working either the right or left hand "side "of the road or for up or down the roads lineal lay.

Beneficially counter-active to the wheel canting provision just described are means resisting the tendency of the truck 10 to respond to the in-t'oeing of wheels 36. This last named means cooperates with the ,provision for Wheel can'ting just described, 'in "the sense of. assuring that wheels 36 track properly, without the use of rim flanges which might undesirably cut into the road finished surface. Said means preferably includes riders or rollers 58 mounted on the L beams. The rollers 58 rollably engage with the staked road building side forms 60, whose structure is well known to the art, but may here be conveniently described.

Referring to Figs. '1 and 2, where these side forms are best shown and t'oZFi'g. '7 where a variety thereof isfiill'us trat'e'd, one will see that these side forms are basically angle irons e'ac'h approximately of about It) foot length and having quite large section. One leg 61 of the angle iron form acts as a foot adapted to rest upon the graded road bed. The other leg 62 of the form is upstanding at right angles to leg 61 and provides a curb against which the aggregate is poured. In some cases, like that shown in Fig. 1, the leg 62 may have a channel projection 63 or other configuration which, in the finished road, forms shapes, such as a relief groove 64 shown.

Suitable bracing gussets and webs extend between the legs 61 and 62. One variety of these is shown at 65 in Fig. 1, another at 66 in Fig. 7. Most often, the upper edge of the leg 62 is bent upon the leg and itself to form a large head 67. The bead 67 provides a fiat rail face 68 with a depending edge flange 69. The rail face 68 provides support for the wheels of the aggregate pouring and road finshing equipment, during the building operation, and serves as a screeding or finishing gauge to the road builder. It is on this face that the heretofore described wheels 36 are set to ride, while the rollers 58 rotatably engage, somewhat, cam-wise, the edge flange 69.

The rollers 58 are each identical in form and support. Hence, to describe the details of one should suffice for both. Each roller 58 is rotatably supported on a stub shaft 70. The shaft 70 is supported in a bracket 71. Each bracket 71 has an upright extending triangular outlined web 72 and a generally square step 73 at right angles to the web 72. The web 72 and step 73 are integrated, as by welding, to one end of L beam 22 so that the web 72 and step 73 extend outwardly and at right angles to the wide flanges 25 of the L beam 22. The step 73 has a journal opening therein for receiving, in bearing relation, one end of a stub shaft 70. If desired, the shaft 70 may also support a thrust spacer sleeve 79 for holding the roller 58 to rotation in a plane corresponding with at intersected by the edge flange 69 when the wheels 36 engage the rail face 68. The end of the shaft may be threaded to receive washer and nut 80 and thus lock the roller 58, sleeves 79, shaft 70 and bracket 71 together in operative relation.

This operative relation will be appreciated, when it is recognized that with the wheels 36 positioned to toe-in, as explained, and the rollers 58 in engaging the flanges 69, limit the trucks response to wheel toe-in. The resultant effect is to produce forces preventing the truck 10 from running off the road and, particularly, the wheels 36 from off the rail face 68, as the truck is moved along the road to engage successive stakes. This eliminates the need for flanging the wheels 36 and assures that the weight and stake pulling forces exerted by and on the truck 10 will be transmitted through the wheels 36 and the side forms 60 and to the road sub-grade, rather than on the curing road aggregate.

The truck 10, as before mentioned, supports power generator elements on the spider 29 and within the housing 31. In the particular construction described, compressed air is utilized as the power medium. Hence, the power generator elements include a motor driven compressor 84 suitably mounted on a superstructure frame 81, above the spider 29, and a suitable pressure tank 82 below the compressor. The tank 82 is connected by a conduit 83 to a power converter on the truck 10. 9

In the particular described construction, the power convertor comprises a cooperating cylinder 85 and piston. The cylinder 85 may have an exhaust manifold 86 and communicates with the pressure tank 82 through the conduit 83' and a valve (not shown). Preferably, the cylinder 85 is mounted near the upper end of a vertically extending column 88. The column 88 engages and, by welding, preferably, at its lower end is connected to the narrow flange 24 of L beam 23 at points intermediate the pair of struts 27. Preferably, the column 88 is a channel bar having a projecting tongue 89 at its upper end. vThe tongue 89 meshes with clevis parts 90 on the upper end of the cylinder 85. A suitable clevis pin 91 joins the cylinder and column together. Thus, the cylinder 85 may swing away from the column 88 in fitting most effectively to exert stake pulling forces, as will later appear.

The piston of the cylinder 85 connects with the stake grappler and puller 14 by means of piston rod 92. Preferably, such connection is of an articulated character. This enables easy manipulation of the grappler and puller 14 to effect registration with the stake, preliminary to exerting the draw force. Also such connection assures a direct straight line transmission of the forces exerted in pulling. In the particular construction shown in the accompanying drawings, the articulated connection between the piston rod 92 and the grappler-puller 14 includes a coupler 95.

The coupler 95 has an end flange 96 at one end and a clevis pair 97 at the other end. The flange 96 extends normal to the coupler 95 and has a circular opening 98 therein. The opening 98 is adapted to receive and journal with an end of the piston rod 92, such as the reduced and threaded end 99. The end 99 extends through said opening and with a nut 100 threaded thereon which provides a thrust bearing to support the coupler 95 for rotation about the piston rod axis.

The clevis pair 97 at the other end of the coupler 95 have aligned circular openings 101 whose common axes extend at right angles to the axis of the opening 98 in the flanged end 96 of the coupler. Thus, a part which pivotally joins the clevis pair 97 will be connected for universal movement relative to the column 88 and the cylinder 85 supported thereon. Such a part is a draw block 105 of the stake grappler-puller 14.

The draw block 105 may, as shown, he a rectangular plate body have an opening 107 at one end to receive a clevis pin 106, when the draw block is placed between the clevis pair 97, as shown in Figs. 4 and 5 of the accompanying drawings. In addition, the draw block 105 has means cooperating to connect the draw block 105 to a chuck head 110 of the grappler-puller 14 for limited relative movement between the two. This type connection, commonly known as a lost motion connection, operates so that, although movement of one part causes ultimate movement of the other, there is a phase in the movement of one part in which the other dwells. The particular lost motion connection means includes a pair of stud pins 111. The pins 111 extend parallel to the axis of opening 107 in the draw block 185 and have free opposite ends 112 which extend a short distance beyond the planes of the opposite faces of the draw block. The stud pins 111 are preferably at spaced points on a straight line intersecting the axis of connection between the clevis pair 97 and coupler 95 (see Fig. 4) and provide bearing and guidance to a bifurcated guide strap 114.

The guide strap 114 has its two legs 115 provided each with a lineally extending slot 116 therein. When properly assembled, the stud pins 111, extending from one face of the draw block 105, extend through the slot 116 of one leg 115 of the guide strap 114 and the stud pins extending from the other face of the draw block extend through the slot 116 of the other leg 115. Thus, the guide strap 114 and draw block 105 may be reciprocated along a straight line relative to each other through limited distances without effecting movement of the other or the chuck head 110 connected to the end of the guide strap 114. This provision is advantageously utilized to operate parts of the grappler-puller 14 as will later be explained.

Preferably, the chuck head 110 comprises a pair of parallel spaced plates 120. The plates 120 have identical dimension and outline and are connected to and are on opposite faces of the end of the guide strap 114 so that the profile of both plates 120 register, as shown in Fig. 4. Each plate 120 has a reentrant lower edge 121 forming a bay 122 extending upwardly between two projecting ears 123. The bay 122 constitutes the working or target zone into which an exposed end 125 of a stake 126 to be drawn is, by manipulation of the chuck head, through means of a suitable handle 13!), located preparatory to stake grappling and pulling.

The stake 126 and its companions shown in the drawings are representative of those common to art. It will be observed they are made from metal dowel stock of about 1%" diameter, a ground off pointed end, a smooth shank and no head, as spikes or nails have. Usually there are three stakes required to anchor each side form 6i).

The forms 6% have suitable openings through which the T.

stakes are driven into the sub-grade. In the construction shown in Figs. 1 and 2 of the accompanying drawings, there is an oval opening 132 in the gusset in vertical alignment with circular opening 133 in the leg 61. In addition, the gussets may have shims or wedges 134, in opposed and vertically spaced relation. in setting the side forms shown in Fig. 1, the stakcs 126, after the form has been properly lined and graded, are each placed, point down, extending through the oval opening 132, between shim wedges 134 and through the opening 133 in the form foot. With a sledge or power hammer, the stake 126 is then driven well into the road sub-grade. Particularly, each stake must be driven so that the upper end 125 is below the plane of the face '63 and thus out of the Way of road construction machinery passing thcreover. The relation of stake ends 125 to the form parts, when properly driven, is fairly shown by the stakes marked S, in Fig. 1. When thus driven, the operator by driving the shim wedges 134 locks the form 69 to the stake 126, all in a manner known to the art.

Very similar operations are followed, when setting stakes using forms of the type shown in Fig. 7. However, in forms of that type there usually are no shim wedges 134. Instead, the axially and vertically aligned holes 136 in the gusset 66 and leg 61 are of a size closely fitting the shank of a stake 126. The stakes are, as before described, initially placed point down extending through the holes 136. Then, the stakes are driven well into the sub-grade, until only a short stub end 125 extends above the plane of the gusset 65.

When, by manipulation of the handle 13h, the chuck head 11% is located above the stake end 125 so that such stake end extends upwardly between the ears 123 into the bay area 12?. formed thereby, the first upward movement of the draw block causes such stake end to be seized by jaws on the chuck head 110. in the particular construction shown in the accompanying drawings, such jaws are embodied in a pair of jaw cranks 15%.

Each jaw crank 15% is similar to the other, except that one (looking at Fig. 4 of the accompanying drawing) is a left hand one and the other a right hand one. Both jaw cranks are substantially housed between the plates 12%} and are pivotally connected thereto for rocking movement. Each jaw crank 151 preferably has th triangular outline, sometimes found in bell-cranks. instead of having three pivotal connecting points as hellcranks do, however, each jaw crank 15% has but two: one a circular bearing opening 151 at the fulcrum corner of the crank and the other the circular bearing opening 152 at the power corner of the crank. The working corner 153 of the crank jaw 159 has a beak 154. The beak 154 preferably has an reentrant, almost arcuate, edge 155 (see Fig. '6) that approximates the cylindricity of the stake end 125.

The relation of the bearing openings 151 and 152 to the beak 15a in each jaw crank produces the critical downward or stake-ward movement of the beaks 154 as they close on the stake end 125. Because of this motion, instead of movement away from the stake as oc curs in prior art construction, the beaks 15 i grapple the exposed stake end 125 very securely-cven though such exposed stake end be short and stubby. This critical relation of the points of openings 151 and 152 to the beaks 15-1 is best shown in Fig. 4 of the accompanying drawing. It also may be described as a relation in which the beak 154- on each jaw crank 15%) is on one side of'a straight line passing through the axes of bearings .151 and 152. and on the far side of a second line normal to said first line and passing through the axis of fulcrum bearing 151 to that on which the power bearing 152 is located. Thus, the bearings 151 and 152 and the beak 154 are at the vertexes of an obtuse triangle, the fulcrum opening 151 being at the obtusive vertex of said triangle. Another way to describe this relation is based on the view that the jaw beak 15 3- and power bearing 152 have clock face positions four hours apart, i. e. nine and one oclock positions in relation to the fulcrum bearing 151, as shown in Fig. 4-. This puts the jaw beak 154 above the fulcrum bearing 151 in each case.

When the cranks 150 are to engage the stake end 125, the right hand crank (in Fig. 4) moves angularly counterclockwise about its fulcrum bearing 151 and the left hand crank clockwise. Thus, the jaw beaks 154 lead the jaw crank 15!) in rotation to closure. Disengagcment is effected, of course, by reverse angular movement of the jaw cranks.

To support the jaw cranks 15h for such movement, suitable fulcrum pins 158 extend through openings or hearing journals 159 in the ears 123 of the chuck head 1'10 and through the fulcrum bearing 151 of the crank. The journals 159 are spaced from each other horizontally a distance less than twice that between the jaw beak 154 and its fulcrum bearing 151. Each jaw crank is separately supported at a point below its beak 154. In order to produce the desired rocking movement of the jaw cranks, we attach link pairs 1-69 pivotally, as by link pins 161, to the power bearing 152 of each jaw crank. The link pairs 160 are also connected to the draw plate 105, by pins 163 fixed on the draw plate. The pins 163 for each link pair 160 are on opposite sides and equally spaced from a straight line passing through the axes of stud pins 111 and the opening 107 in the draw plate which receives the clevis pin 1%.

Now, when the draw plate 165 moves relative to the chuck head 110, as permitted by the loss motion connection between them, the link pairs 160 cause rocking movement of the jaw cranks 15h. Particularly, when the draw plate 105 moves away from the chuck head 110, the link pairs 16% cause the jaw cranks 150 to rock in directions bringing the jaw beaks 154 together until they grapple the stake end 3.25 therebetween, much as shown in Fig. 4 of the accompanying drawing. As the cranks move to bring the beaks 15d together, the fact that the beaks lead the cranks in the direction of their closing movement should be note Once the beak-s 154 close on the stake end 125, the further relative movement of the draw plate 165 away from the chuck head 119 is resisted through the link pairs 160. Continued movement of the draw plate H25 in a direction away from the chuck head 119 will hence cause corresponding movement of the chuck head lilditself in that direction, along with the stake 126 seized between the beaks of the jaw cranks. The resistance of the stake to upward pull tends to draw the jaws into greater congestion about the stake because such pull tends to rock the jaw cranks toward making what for them is an impossible pass between the journals 159. This produces a grappling strain to be exerted on the stake 12.6 between the jaw crank-s, and allows drawing of such stake from out of the roadsu'bgrade to thereby free the side form an held "by such stake.

In operation, after the aggregate has been poured and has set up sufiiciently stiff for pedestrain passage, the truck 10 is mounted with its wheels 36 riding the rail face 68 of a line of side forms 5t and its pneumatic tired wheel 35 riding over the finished surface, as shown in Pig. 1 of the accompanying drawings. The operator then sets handles "52 pointing in the direction along the successive forms 60 in which the truck 10 is to be moved. With the motor of compressor 84 started, the operator 'is ready to begin work. 7

He first rolls the truck so that the chuck head 110 is generally above the exposedend 126 of the first stake 125 to be pulled. Then grasping the handle 136 and through controls (not shown) mounted thereon, in a manner known in the art, he opens the exhaust 86 of the cylinder 85 and moves the chuck head 110 downwardly. This can be easily done because, once cylinder 85 exhausts, the weight of the piston rod 92 and the coupler 95, draw block 105 and linkage connected thereto overcomes most tendency of the parts to resist such downward movement.

Having lowered the chuck head 110, the operator manipulates it to position the stake end 126 in the bay 122 and between the ears 123. In such manipulation, the operator lifts the chuck head 110 slightly, moving it toward the draw plate 105. This through the links let? causes the jaw cranks 150 to rock indirections separating the jaw beaks 154. By directing the chuck head now so that the stake end 126 is between the separated beaks and allowing the chuck head to fall, the links cause the jaw cranks to rock in beak closing relation and take a preliminary grapple on the stake end. Then, through movement the controls on the handle 130, the operator momentarily effects a connection between the pressure tank 82 and cylinder 85 through conduit 83. This causes the draw block 105 to rise first. The rise of the draw block 105 causes the jaw cranks 150 to close more tightly on the stake end 126.

Now, the operator is prepared for the hard pull. He manipulates the controls on handle 130 to again open communication between conduit 83 and cylinder 85. The pneumatic pressure exerts full upward force in the cylinder through the piston rod 92, the coupler 95, the draw block 105 and chuck head 110 tending to pull the stake 126 upwards and free; to the position shown by the stake marked F, in Fig. 1 of the accompanying drawings. Should the stake resist the direct pull exerted by the equipment, the operator, using the handle 130 may rotate and apply a torque to the chuck head 110 and stake 126, thus tending to break any frictional grip which the road sub-grade elements may have on the stake 126. This becomes possible because of the universal support of the chuck head 110 and the continued pull of the draw block 105 exerts continued closing pressure on the jaw beaks, which increases as the pull exerted on the draw block increases. Such result becomes possible because the stake grippingjaw beaks lead in the direction of the pull, the resistance of the stake to the draw block acting to bring the beaks ever closer. In this way, wear of the beak if and when it occurs is automatically compensated for.

When the stake 126 is drawn, the operator, by shift of the controls on handle 130, reduces pressure in the cylinder 85, lowers the chuck head 110, freeing the then drawn stake. The truck 10 is then moved to the next stake and the same procedure enacted. In passing over the rail face 68 of successive side forms, the rollers 58 engaging the flanges 69 cause the wheels 36 to track the rail face 68.

It will be noted that in each stake pulling operation, the forces needed to effect extraction of the stake are exerted from the chuck head 110 upwardly through the articulated connection thereof with the tongue 89 at the top of column 88. These forces, to the extent that the clevised end of tongue 89 is offset horizontally from the vertical plane of support provided by Wheels 36, tend to tip the truck 10 sidewise. However, the truck frame 21 extending from the L beams 22 and 23, particularly the angle iron struts 27 and 28, in relation to the mass of the tank 82 and compressor 84 supported on said struts provides a lever arm means exerting forces in counteraction to the stake pulling forces about a fulcrum provided by the wheels 36 and keeps the truck from tip- 10 ping. In so doing the major forces ultimately come to focus and bearing on the form 60 and by it are advantageously transmitted to the sub-grade of the road.

While we have illustrated and described the best form of our invention now known to us, as required by the statutes, those skilled in the art will readily understand that changes may be made in the disclosed construction without departing from the spirit of our invention as set forth in the appended claims. 1

We claim:

1. In a stake grappling and pulling machine, a stake engaging chuck having a head and a pair of jaw cranks, said head having a pair of bearing journals in spaced relation; each jaw crank having a working arm and a power arm and a fulcrum bearing therebetween; a pair of pivot pins; each pivot pin being in engagement with a fulcrum bearing of one of said jaw cranks and with one of said bearing journals on said head whereby each jaw crank is supported for rocking movement on said head; the working arm of each jaw crank having a beak near its outer end; the power arm of each jaw crank having a bearing near its outer end; said beak and fulcrum and power bearings being in a spacial relation as are vertex points on a triangle; and movable means in engagement with said power bearing of each crank and operable on movement to rock one crank clockwise and the other crank counter-clockwise with the respective jaw beak of each jaw crank leading in the particular direction of rocking of its related jaw crank.

2. In a stake grappling and pulling machine, a stake engaging chuck having a head and a pair of jaw cranks; said head having a pair of bearing journals in spaced relation; each jaw crank having a working arm and a power arm and a fulcrum bearing therebetween; a pair of pivot pins; each pivot pin being in engagement with a fulcrum bearing of one of said jaw cranks and with one of said bearing journals on said head whereby each jaw crank is supported for rocking movement on said head; the working arm of each jaw crank having a beak; the power arm of each jaw crank having a bearing; said beak and fulcrum and power bearings being in a spacial relation to each other as are vertex points on an obtuse triangle, the fulcrum bearing being at the obtusive vertex point and the beak and power bearing being at points above a straight line in diametric relation to both axes of said bearing journals on said head; and movable means in engagement with said power bearing of each crank and operable on movement to rock the cranks and move the beaksthereof relative to each other and to thereby grapple a stake.

3. In a stake grappling and pulling machine, a stake engaging chuck described in claim 2 in which the bearing journals on said head are in a spaced relation of less than twice the distance between the jaw beak and fulcrum opening of one of said jaw cranks.

4. In a stake grappling and pulling machine having a stake engaging chuck described in claim 3 in which said head comprises a pair of parallel spaced plates of identical outline in perimetrical registration and having substantially a space enclosing relation, and said jaw cranks are between said plates and within said space thereby being in housed relation with the plates.

5. In a stake grappling and pulling machine having a stake engaging chuck described in claim 4 in which each of said plates has a reentrant edge delineating a bay between two projecting ears, said pair of registering ears having one of said pair of said jaw cranks supporting bearing journals therein.

6. In a stake grappling and pulling machine having a stake engaging chuck described in claim 5 in which said head has a strap bar with a bifurcate end, the other end of said strap bar being between said plates and in engagement therewith and providing means to connect the plates together, each bifurcate part of the bifurcate 1 1 end being parallel to the other and having a lineally extending slot therein parallel to the corresponding slot inthe companion bifurcate part.

7. In a stake grappling and pulling machine having a stake engaging chuck described in claim 6 and in addition thereto a draw block for moving said chuck, said draw block having two opposite faces in parallel spacial relation substantially equal to the distance between said bifurcate parts of said bifurcate end of said strap, said draw block having a pair of stud pins on each said face and in a relation of extending through said slot in one of said ibifurcate parts of. said bifurcate end of said strap to allow, by the stud pins engagement of only the opposite ends of said slot, limited independent movement of the draw block relative to the chuck head and upon engagement of pins and slot ends produce movement .of the draw block and chuck head together.

8. In a stake grappling and pulling machine having a stake engaging chuck and in addition the draw block described-in claim 7 in which said movable means operahle :to rock the cranks includes a pair of links; each link having one end thereof in pivotal engagement with said power bearing of one of said jaw cranks and the other end in pivotal engagement with said draw block 12 at a point on the opposite side of a line passing through both' of said draw-Block stud pins from that on-which the other link pivotally engages said draw 'block.

9. In a stake grappling and pulling machine having a stake engaging chuck and in addition "the draw hloe'k described in claim 8 and addition thereto having a power exerting means in engagement with said draw block operable to move the draw block relative to the head and comprising a source of air under pressure; a cylinder and piston; a conduit in communication with said source of air under pressure and said cylinder; and a coupler in engagement with said draw block and piston.

References Cited in the fileiof patent UNITED 'STATES PATENTS 550,878 Gilrnan Dec. 3, 1895 1,716,004 Ridley June 4 1929 1,771,712 Jimerson July 29, 1930 l,893,71-9 Talboys Jan. 10,1933 1,986,138 Creason Jan, L, 1935 2,376,251 Howerton May 1 5*, 1945 2,671,414 Moe Mar. 9, 1954

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