US 2837335 A
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Description (OCR text may contain errors)
June 3, 1958 F. c. KOENIG 2,837,335
' STILT CONSTRUCTION Filed March 16, 1955 5 Sheets-Sheet 1 I N VENTOR FREDERICK G K 05 N16 BY v 40% ATTORNEYS F. c. KOENIG 2,837,335
STILT CONSTRUCTION 5 Sheets-Sheet 2 June 3, 1958 Filed March 16, 1955 A. M ii: a
- INVENTORY FREDERICK U. KOE/V/G Y ATTORNEYS June 3, 1958 c, KOENIG I 2,837,335
STILT CONSTRUCTION Filed March 16, 1955 5 Sheets-Sheet 5 INVENTOR Mom/0x, a ROE/W6 BY QM; [0 ,465
ATTORNEYS United States PatentO TILT CONSTRUCTION Frederick C. Koenig, West Palm Beach, Fla. Applicationll/iarch 16', 1955, Serial No. 494,722
14) Claims. (Cl. 27270.1)
This invention relates to stilt constructions which may be worn by an individual and have mechanism operable by the foot of the wearer for enabling the stilts to be extended and retracted so as to permit the wearer to raise and lower himself without the necessity of his using his hands or removing the stilts.
The invention is particularly suited for use by bricklayers, plasterers, painters, and others, whose occupationsrequire them to work at successively different levels and to have sufiicient mobility to be able to move laterally to Work zones outside the reach of their arms. Heretofore, it has been necessary for a workman to erect scaffolding or use a ladder to enable him to reach work zones above his head, but these practices are not altogether satisfactory because of the time required to erect scaffolding or move a ladder from a zone where work has been completed to a zone where work is to be done. Furthermore, scaffolding and ladders have an additional disadvantage in that their placement usually enables the workman to work comfortably in only a single, limited work zone. If the workman is to work comfortably, he must make time consuming multiple adjusunents of his support.
An object of the invention is to provide stilt constructions which may be worn by a person and which include mechanism operable by the wearer without the necessity of his using his hands or removing the stilts, for raising and lowering himself.
Another object of the invention is to provide a stilt construction adapted to be worn by an individual and having means for elongating and shortening the stilt controllable by the foot of the wearer.
Another object of the invention is to provide a vertically adjustable stilt construction having means for locking the stilt in adjusted position.
Other objects of the invention will be pointed out specifically or will become apparent from the following specification and claims when considered in conjunction with the accompanying drawings, in which:
Figure l is a front elevational view, partly in section, of one form of the invention;
Figure 2 is a side elevational view, partly in section, of the construction shown in Figure 1;
Figure 3 is a sectional view taken substantially along the line 3-3 of Figure 2;
Figure 4 is an enlarged fragmentary sectional view taken along the line 4i of Figure 3;
Figure 5 is a side elevational view of a modified form of the invention;
Figure 6 is a front elevational view of the construction shown in Figure 5;
Figure 7 is a sectional View taken along the line 7-7 of Figure 5 and turned through 180 degrees;
Figure 8 is an enlarged fragmentary sectional view taken along the line 8-8 of Figure 7;
Figure 9 is a side elevational view of another modified form of the invention;
Figure 10 is an enlarged fragmentary sectional view taken along the line 1010 of Figure 9 Patented June 3, 1958 "ice Figure 11 is an enlarged fragmentary sectional view taken along the line 1111 of Figure 10;
Figure 12 is a front view, partly in elevation and partly in section, of another modified form of the invention;
Figure 12A is an enlarged detail view of aportion of the construction shown in Figure 12;
Figure 13 is a reduced side elevational view of the construction shown in Figure 12;
Figure 14 is an enlarged sectional view taken along the line 14-14 of Figure 12; and
Figure 15 is an enlarged sectional view taken along the line l515 of Figure 12.
In the embodiment of the invention shown in Figures 1 to 4, inclusive, an extensible and retractable stilt 1 comprises a first support member 20 having a substantially channel shaped cross-sectional configuration. One end of the support member 2% is provided with a flat, ground engaging plate 21, the bottom face of which is equipped with a rubber or the like pad 22 so as to provide'a nonskid and mar-preventing ground engaging surface. Two opposite side walls of the member 20 are provided with flanges 23 and 24, the facing edges of which define a longitudinally extending slot 20 The flange 23 is wider than the flange 24 so that the siot 20 is ofiset slightly to one side of the center line of the supporting member 20. A plurality of preferably cylindrical pins or stops 26, arranged in vertically spaced relation, extend between the flange 23 and the rear wall of the support member 20 and are secured in their respective positions in any suitable way, such as by spot welding.
A second support member 30 is mounted for vertical movement relative to and within the first support member2l). The support member 30 preferably is of substantially rectangular cross sectional configuration; as shown, but one wall 30 may be provided with a slot 30 extending substantially the entire length of the member, or, if desired, the wall 36 may be eliminated entirely.
At its upper end the member 30 may be provided with an arcuate part 31 having slots 32 at its extremities for reception of a leg encircling strap'33, at one end of which is a buckle 34. If desired, the part 31 may be adjustably secured to the member 3%) by means of a cooperable screw 31= and screw holes, two of which are shown at 31 so as to permit the part to be mounted on the member 31) at a position most comfortableto the individual user.
At the lower part of the support member 30 there is journalled a rock shaft 35. Mounted on and'fast with the rock shaft 35 is a holding element formed. as a pawl 36 adapted to project through a slot 30 formed at the lower part of the support member 30 and prevent relative vertical movement of the members 20 and 30 by engaging a selected one of the stops 26 in a manner to be described more fully hereinafter. The rock shaft 35 extends outwardly through the slot 20* between the flanges 23 and 24 and projects through a bracket 37 which. is fixed to the underside of a foot support or' plate 38. The end of the shaft 35 which is remote from the member30 is journalled in an upstandingpart 35 of a bracket 35 which is fixed to the member 30 and projects through the slot 20 The shaft 35 and thebracket 37 are made fast with one another in a suitable way, such as by welding, so as to preclude relative rotation between the two parts. Thus, the rock shaft 35 interconnects the foot plate 38 and the pawl 36-and is operablein response to rocking of the foot'support 38 to rocktlie pawl 36 and control the position of the pawl.
The foot support 38 is provided at its rear end with a heel retainer part 39 slotted as at 40 to receive a strap 41 adapted to be fastened around the ankle of theuser. At the front end of the foot support 38 therev is :a
of ea1:s,42, each of which is slotted to receive a portion of a strap 43 adapted to be fastened over the toes or insteps of the user.
Means-for biasing or urging the second support member 30 upwardly,relatively'to the lower support member 20; is providedand in the form of the invention shown in; Figures, 1 through 4 the biasing; means comprises a spring 45 located within the upper support member 30 and having its upper end secured to a lug 46 fixed to the inside of the first support member 20 adjacent to its upper end and projecting through the slot 30 The lower end of the spring 45 may be secured to a lug 47 fixed ,to an inside wall of the second support member 30 adjacent to the rock shaft 35.
' ;,:';Only ,one stilt has been described in connection with the construction disclosed in Figures 1-4 and that stilt "isyadapted to be fastened on the right leg of the user. In this embodiment of the invention, as well as in the embodiments yet to be described, the two stilts of a pair will be identical in construction except that one will be for the right leg of the user and the other will be for the left leg.
When using a pair of stilts constructed in accordance.
with the embodiment of the invention shown in Figures l%-.4," one stilt 1 will be secured to each leg and foot of the user by means of the straps 33, 41 and 43. Assuming that the foot plate 38of each stilt is in its lowermost position, that is, adjacent to the base plate 21, and assuming that the user wishes to elevate himself to a higher level, the user shifts his weight to one foot and rocks his-other foot about his ankle joint in a movement simiislar to that assumed during normal Walking conditions, i. e. the foot moves in a plane of articulation substantially coinciding with the general plane of the users leg, .moving the foot plate 38 clockwise, as viewed in Figure 2. The removal of weight from one stilt permits the nose of the pawl 36 to be rocked in response to rock- .-ing of the foot plate and be withdrawn from between adjacent pins 26 so as to permit relative movement between the support members 20 and 30. By holding his foot, and consequently the foot plate 38, in rocked position, the user may move the member 30 upwardly, relatively to the member ,20, the upward movement of the .member 30 being assisted by the spring45. When the one stilt has been extended to the desired level, the user rocks his foot and the plate 38 counterclockwise, as viewed in Figure 2, so as to rock the pawl 36 counterclockwise to project its nose between a pair of adjacent .pins 26. The interengagement of the pawl 36 and a pair of adjacent stops 26, together with the adjacent Wall of the member 20, prevents the foot plate 38 from being rocked in a counterclockwise direction from the substantially horizontal position shown in the drawing. Accordingly, the foot plate 38 afiords support in a substantially horizontal plane for the foot of the user. With the plate 38 in horizontal position, the user may shift his weight --to the foot carrying the extended stilt, which will support his weight due to the interengagement of the pawl 36 and one of the pins 26, and extend the other stilt in a manner similar to that just described.
-To retract the stilts and lower himself, the user goes through the same procedure just described, except that -.when the pawl 36 is withdrawn from between adjacent pins 26 in response to rocking of the foot plate 28, the Auser pushes down on the foot plate so as to cause the member 30 to move downwardly relatively to the member 20.
Means is provided for locking the foot plate 38 in horiz'ontalposition so as to prevent the pawl 36 from being withdrawn inadvertently from engagement with the pins or stops.26. The locking means comprises a rod .50 projecting through. the closed upper end of the support member 30, the upper end of the rod being provided :with'an enlarged part or finger grip 51 adapted to bear againstla washer or the like 51 which surrounds the rod and rests on the top of the member 30. The lower end of the rod 50 is threaded as indicated at 52 and is adapted to be received in a hole 53 tapped in a link 54, the lower end of the link being pivoted as at 55 to an intermediate portion of the pawl 36. To lock the foot rest in horizontal position, the rod 50 is screwed into the link 54 by means of the finger grip 51 until the part 51 bears against the washer 51. In these positions of the parts, it is not possible to rock the foot plate 38 clockwise, and the stilt user need not constantly be on guard to prevent inadvertent withdrawal of the pawl 36 from between a pair of adjacent pins 26. To disable the locking means the rod 51 is unscrewed from the link 54 a distance sufficient to remove the finger piece 51 from engagement with the washer 51 prior to the foot plates being rocked.
Figures 5 through 8 disclose a modified form of stilt construction 59 in which the first support member 60 comprises an elongated, generally rectangular rod having a ground engaging plate 61 secured to one end of the rod. The plate 61 may be provided on its lower face with a rubber or the like pad 62 similar to the pad 22 shown in Figures ,1 and 2. One face of the first support member 60 is provided with a channel or groove 64 which extends from end to end of the rod. Mounted for relative movement externally of the support member 60 is a rectangular, hollow, or tubular second support member 63. The member 63 cariies a lug 65 to which is secured one end of a coil spring 66, the spring 66 being positioned within the channel 64 of the support member 60, and having its other end secured to a lug 67 carried by the support member 68 adjacent to its upper end.
Adjacent to the upper end of the second support member 63 there is secured, by suitable means such as screws 68, an arcuate part 69 similar to the part 31 shown in Figures 1 and 2, the ends of which are slotted as at 70 for reception of a leg engaging strap (not shown).
A foot supporting plate is pivotally mounted on the support member 63 by means of a rock shaft 76 which is mounted at one end for rocking movement in a block 77 secured to the lower end of the member 63. The block 77 has a laterally extending wing 77 including a flange 77 which provides a bearing for the other end of the shaft 76. The block 77 contains a recess 78 within which is mounted a holding element in the form of a cam or clamp 79 fast with the rock shaft 76, the shaft thus constituting means for interconnecting the cam and foot plate. The cam 79 has an arcuate face 80 which is adapted to be rocked in response to rocking of the shaft 76 into and out of clamping engagement with the bottom face of the groove or channel 64 so as selectively to prevent and permit relative vertical movement of the support member. The foot plate 75 includes a heel retainer 91 and a toe retainer 92, each of which is provided with slots 93 and 94, respectively, adapted to receive straps (not shown) for securing a foot of the user to the foot plate.
The operation of the stilt construction 59 is similar to the operation of the embodiment disclosed in Figures 1. through 4 in that rocking of the foot plate 75 counterclockwise, as viewed in Figure 5, causes a corresponding movement of the cam 79 so as to unclamp the cam face Stl from the channel 64 to permit relative vertical movement of the first and second support members 60 and 63. Rocking of the foot plate '75 in the opposite direction causes a corresponding movement of the cam 79 to engage the cam face 80 clampingly against the support member 60 so as to prevent relative vertical movement of the two members. The arcuate face of the cam is so formed as to permit the foot plate 75 to lie in a substantially horizontal plane when it supports the weight of the stilt user.
Locking means are provided for holding the cam 79 in clamping engagement with the support member 60, and
inthe form shown, the locking means Comprises a rod 81 having a threaded lower end received in a threaded socket member 81". The upyer end of the rod 81 passes through an opening in a flange 63 forming a part of the support member 63, the upper end of the rod 81 terminating in a finger piece 82. The lower end of the socket member 81 is pivoted as at 83 both to a link 84 and to a second link 88. The second link 88 is pivoted to a lug 90 carried by the support member 63 by means of a pin 89. The lower end of the link 84 extends into a recess 86 formed in the cam 79 and is pivoted to the cam by means of a pin 85.
Tolock the members 60 and 63 in relatively immovable relation, the cam 79 is rotated into clamping engagement with the member 60 in response to rotation of the foot plate 75, and the rod 81 is screwed into the socket member 81' until the finger piece 82 bears against a washer 82 mounted on top of the flange 63a. The engagement of the finger piece 82 and washer 82 prevents the cam 79 from being rotated out of clamping engagement with the member 60. To disable the locking means prior to unclamping rocking of the foot plate, the rod 81 isunscrewed from the socket 81 a distance sufficient to remove the finger piece 82 from engagement with the Washer 82*.
Figures 9 through 11 disclose a stilt construction 99 including first and second support members 100 and 106,
respectively, mounted for relative vertical movement.
'tangular part 107 is welded or otherwise rigidly secured adjacent to the lower end of the member 100 on three sides, the fourth side of the member 100 being slotted as at 100 One wall 107 of the part 107 is spaced from the member 100 so as to provide a space therebetween, and a holding element, namely a clamping block 110 adapted to clamp against the member 106 is located in the space between the wall 107 of the part 107 and the "member 100. The block 110 is adapted for movement through the slot 100 into and out of clamping engagement with the support member 106 selectively to prevent and permit relative vertical movement of the members 100 and 106.
The part 107 has an extension 120 secured thereto having an upwardly directed flange 121 which is apertured to provide bearing means for one end of a screw threaded rock shaft 108, the other end of which projects through a hole tapped in the wall 107 of the part 107. The
nose 109 of the shaft 108 is tapered and seats in a corresPo'ndingly shaped recess in the movable block 110 so as to cooperate with the facing walls of the parts 106 and 107 to prevent the block 110 from dropping out of the bottom of the block 107. A foot rest or plate 112 is mounted fast on the shank of the screw 108 by means of brackets 111 which may be spot welded to the screw. Thus,'the screw 108 interconnects the foot plate 112 and the block 110 so that rocking of the foot plate controls the operation of the'block to clamp or unclamp the support members. I g g p 'The foot rest 112 includes heel retainers 113 slotted as at 115 for reception of ankle engaging straps (not shown) and at the forward end of the foot rest 112 there aretoe retainers 114 slotted as at 116 for reception of footengaging straps (not shown).
The operation of the stilt 99 is similar to that described :in connection with the previously described embodiments of the invention in that rocking of the shaft 108 in response to rocking of the foot plate 112 selectively per- 6 mits or prevents relative vertical movement of the support members. counterclockwise rotation of the foot rest 112, as viewed in Figure 9, will cause rotation of the screw 108 in a direction tending to withdraw it from theplate 107 so as to release the block from clamping engagement with the member 106 and permit relative vertical movement of the support members. Rotation of the foot plate 112 in a clockwise direction as viewed in Figure 9 will cause rotation of the shaft 108 in a direction tending to screw it into the plate 107 whereby the nose 109 of the screw will bear against its seat in the block 110 to cause the block to clamp against the member 106 and maintain the two members 100 and 106 relatively immovable, the arrangement of the parts being such as to permit the foot plate 112 to support the weight of the user and lie in a substantially 7 horizontal plane.
Figures 12 through 15 disclose an embodiment of the invention in which the extension and retraction of the stilt is accomplished by combined hydraulic and compressed air piston and cylinder assembly means. The stilt construction of this embodiment comprises a first support member 151 including an outer cylinder 152 and an inner cylinder 153 concentrically positioned within the outer cylinder. At the upper ends of the cylinders 152 and 153 there is a plug 154 cut away on its underneath side to form a chamber 155 and an annular portion 156 which is positioned between the cylinders 152 and 153 and welded or otherwise suitably secured thereto in a fluid tight manner to maintain the cylinders in concentric relation. At the lower ends of the cylinders 152 and 153 there is a part 157 having an annular por tion 158 which is secured in a fluid tight manner to and between the cylinders to maintain their concentricity.
The stilt 150 includes a second support member 159 mounted for relative movement with respect to the first support member 151, and, as shown in Figure 12, the second support member comprises inner and outer cylinders 160 and 161, respectively, concentrically mounted within cylinder 153 for movement relative to each other and to support member 151.
The lower end of the inner cylinder 160 includes an enlarged part 162 which is received in a cup shaped housing 163 formed on the upper surface of a ground engaging plate 164. A cushioning bushing 165 surrounds the enlargement 162 and removably connects the plate 164 to the inner cylinder 160. The lower face of the plate 164 may be provided with a mar-preventing, nonskid pad 166.
The upper end of the inner cylinder 160 is closed and includes an enlarged part 167 which constitutes a guide for the cylinder 160 when it moves relatively to the outer cylinder 161. On the top of the cylinder 160 is mounted a leather or the like cup sealing washer 168 maintained in position by means of a washer 169 and screw 1'70 threaded into the end of the cylinder 160.
The outer cylinder 161 of the second support member 159 carries a threaded part 171 suitably secured to the cylinder at its lower end. A gland 172 is threaded onto the part 171, the dimension of the opening in the gland being proportioned to fit snugly around the inner cylinder 160 to guide its movements. A packing 173 is compressed between the lower end of the outer cylinder 161 and the gland 172 so as to provide a seal between the inner and outer cylinders. The upper end of the outer cylinder 161 has an enlargement as at 174, similar to the enlargement 167, so as to space and guide the cylinder 161 with respect to the cylinder 153. The top of the cylinder 161 is tapped for reception of a hollow screw 175 which serves the dual purpose of anchoring a washer 176 and a leather or the like cup sealing washer 177, and providing a communicating passage 178 between the cylinders 160 and 161.
The cylinder 161 extends beyond the lower end of the support member 151 which is provided with abored 'into the opening between the passages 183 and 184.
nut 179 threaded into the part 157, the bore in the nut being so proportioned as to receive and guide the cylinder 161. A suitable packing 179 is compressed between the nut 179 and a shoulder 179 on the part 157 to provide a seal between the cylinder 161 and the part 157.
The arrangement of the parts described thus far is such that the space between the cylinders 152 and 153 defines a chamber 180 which hereinafter will be referred to as the hydraulic fluid and compressed air reservoir, or simply The plug 154 at the upper end of the stilt 150 is pro vided with a laterally extending passage 181 communicating with the chamber 155 and with a tube 182 positioned in the reservoir 180 and extending between the plug 154 and the part 157 at the lower end of the first support member 151. The part 157 has a vertically extending fluid passage 183, in communication with the tube 182, and an obliquely extending fluid passage 184 (seeFigure 14) in communication with the reservoir 180.
The passages 183 and 184 converge within the part 157 along lines which intersect, but the passage 183 terminates short of intersection with the passage 184 as shown in Figure 14. A tapered opening extending partly through the part 157 and through a boss 185 forming a part thereof provides communication between the passages 183 and 184 and also provides a seat for a valve 186. The valve 186 is ground on one side to leave only a portion 186*, segment shaped in cross-section, extending In one position of the valve 186, such as is shown in Figure 14, the valve segment 186 prevents communication between the passages 183 and 184, but rotation of the valve in either direction will enable the fluid to pass from one passage to the other. The valve 186 thus constitutes control means for selectively permitting and preventing relative vertical movement of the support members 151 and 159 as will be more fully pointed out hereinafter.
The valve 186 is rotatably maintained in position by means of a gland 188 which comprises a packing 190 between itself and a shoulder 191 formed on the valve body, the gland 188 being threaded onto the end of the boss 185.
A foot support or plate 192 is pivotally mounted on the first support member 151 by brackets 193 and 194 secured to the bottom of the support 192 and journalled respectively on bosses 185 and 185 the boss 185- being carried by an extension 187 forming a part ofthe part 157. An car 195 is secured to the under surface of the foot plate 192. One end of a link 196 is pivotally secured to the ear 195 by means of a pivot pin 197, the other end of the link being pivoted by a pin 198 to an arm 199 which is fast with the stem 189 of the valve 186. In the disclosed arrangement of the parts, rocking of the foot plate 192 about its pivots 185 and 185 will cause rotation or rocking of the valve 186 so as to turn the segment portion 186* of the valve selectively to prevent or permit communication between the passages 183 and 184 so as selectively to permit or prevent relative movement of the first and second support members in response to fluid pressure.
In the form of the invention shown in Figures 12-15, means for controlling the rocking of the foot plate 192 comprises a pair of lugs 200 and 201 carried by each of the brackets 193 and 194. The front lug 200 of each pair preferably is the larger so as to engage the surface of the extension 187 upon slight rocking of the foot plate 192 and brackets 193 and 194 in a clockwisedirection,
as viewed in Figure 14, thereby to permit the foot plate 192, in conjunction with the extension 187 and the lugs 200, to support the weight of the stilt user and lie in a substantially horizontal plane. The rear and smaller lug 201 of each pair of lugs is adapted to engage the surface of the extension 187 after substantial rocking of the foot plate 192 and brackets 193 and 194 in a counterclockwise direction, as viewed in Figures 14, so as to permit enough rotation of the foot plate to ensure turning of valve segment 186 to establish communication between the passages 183 and 184 when desired.
A leg engaging part 202 may be secured in any suitable manner to the first support member 151 adjacent to its upper end, the part being slotted as at 203 for reception of a leg surrounding strap (not shown). The foot support 192 preferably includes means (not shown) such as retainers similar to the heel and toe retainers in the other embodiments of the invention for anchoring the user's foot to the plate 192.
The plug 154 at the upper end of the stilt is provided'with a threaded opening 204 which normally is closed by a screw 205, the shank of which is surrounded by a sealing washer 206 adapted to be compressed between the top of the plug 154 and the head of the screw 205. The shank of the screw is provided with an axial passage 207 for a portion of its length, the passage 207 communicating with a radial passage 208 located intermediate the ends of the screw. The significance of the passages 207 and 208 willbe pointed out in connection with the description of the manner of conditioning the stilt construction for use.
To condition the stilt construction for use, the screw 205 is removed from the plug 154 and the second support member cylinders or plungers and 161 are withdrawn as much as possible from the first support member 151, and the cylinder 160 is withdrawn as much as possible from the cylinder 161. Hydraulic fluid then is poured into the opening 204 of the plug 154, completely filling the cylinders 161 and 153, the cylinder 161 being filled through the hollow screw at its upper end. When the cylinders 161 and 153 are full of hydraulic fluid, the screw 205 is replaced and turned down tightly against the seal 206 to seal the opening 204 and to close the passages 207 and 208, The foot plate is manually rocked counterclockwise, as viewed in Figure 14, to turn the valve segment 186 and permit communication between the passages 183 and 184. With the valve 186 open, the plungers or cylinders 160 and 161 are retracted completely by manually pushing them into the support member 151. As the plunger 160 is retracted, fluid within the cylinder or plunger 161 is forced through the hollow screw 175 into the interior of cylinder 153 and displaces fluid from the latter which enters passage 181 from chamber 155 and flows through the tube 182 into passage 183, past the valve segment 186 into passage 184, and emerges into the reservoir 180. When the .support member 159 is completely retracted, the foot plate 192 is rocked clockwise, as viewed in Figure 14, to close the valve 186.
It is necessary that additional or reserve fluid be contained in the reservoir so that even with the stilt fully extended, the reservoir will contain fluid. To accommodate the additional fluid and a head of compressed air, the dimensions of the several parts of the stilt construction should be so selected that the volume of the reservoir 180 is greater than the combined volume of the other parts 153, 155, 161, 181, 182, 183, and 184 through which fluid passes. To add the required additional fluid, the screw 205 again is removed from the opening 204 and the support member 159 partially withdrawn. Indicla, not shown, may be provided on one or both of the cylinders of the support member 159 to indicate when they have been withdrawn the required extent. The cylinders 153 and 161 are filled a second time with hydraulic fluid and, when full, the screw 205 is inserted in the opening 204 and turned down tightly against the seal 206. The same procedure as has been described is followed to force the reserve fluid into the reservoir 180.
To enable the stilt to be extended upon actuation of the valve mechanism, a charge of air is introduced into the hydraulic motor when the'valve 186 is in its closed position by unscrewing the screw 205 a distance sufficient to enable the passage 208 to be uncovered. Then the support member cylinders 160 and 161 are extended manually their full extent, thus drawing air through the passages 207 and 208 into the interior of the cylinders 153 and 161. With the cylinders 160 and 161 fully extended, the screw 205 is turned down tightly against the seal 206, thereby sealing the upper end of the plug 154. The foot plate 192 then is rocked to open the valve 186 and the cylinders 160 and 161 are retracted manually so as to force air through the passages 181, 182, 183 and 184, into the reservoir 180, where it bubbles through the previously admitted hydraulic fluid to the top of the first support member 151 and is compressed. This operation is repeated as many times as is required to cause the cylinders 160 and 161 to extend automatically when the valve 186 is open.
The amount of air forced into the reservoir should not be so great as to cause the stilt to be extended upon rocking of the foot plate 192 when the stilt is supporting the weight of the user. It is preferred that only suflicient air be compressed in the reservoir 180 to exert a force tending to extend the support member 159 when the stilt is not supporting the weight of the user. The compressed air charge, therefore, is similar to the springs 45 and 66 disclosed in connection with other embodiments of the invention in that the compressed air constitutes means for biasing the support members for relative vertical movement.
In use, a stilt constructed in accordance with the embodiment of the invention disclosed in Figures 12-15 is secured to each leg of the user. When the user wishes to elevate himself, he shifts his weight to one leg, raises his other leg and with the foot of the raised leg rocks the foot plate 192 in a clockwise direction, as viewed in Figure 14, so as to open the valve 186 and establish communication between the passages 183 and 184. The compressed air at the top of the reservoir 180 expands and forces hydraulic fluid past the valve 186 into passage 183, into and through the tube 182, through passage 181, and into the cylinder 161, through the hollow screw 175, so as to cause the cylinder 160 to be extended. When the cylinder or cylinders of the second support member 159 have been extended the desired amount, the
valve 186 is closed in response to counterclockwise rota tion of the foot plate 192, as viewed in Figure 14, thereby trapping the hydraulic fluid which was forced past the valve 186 and enabling the stilt to support the weight of the user. This procedure is repeated with the stilt on the other foot in order that both stilts will be extended to the same height. Should the user wish to lower himself, he may rock one or both feet to cause rotation of one or both of the foot plates in a direction to open the valve 186, whereupon the weight of the user causes the second support members cylinders 160 and 161 to be retracted by displacing fluid from the cylinders 153 and 161 through the passages into the reservoir 180 as previously described. It is preferred that the bushing 165 extend slightly above the top of the housing 163, as shown in the drawing, so as to provide a cushion against which the gland 172 on the lower part of the cylinder 161 may rest when the stilt is in fully retracted condition.
Means is provided for locking the first and second support members against relative movement so as to permit the user freedom of movement without fear of inadvertently opening the valve 186. As shown in Figure 12, the locking means comprises a threaded pin 209 mounted in the plug 154 at the upper end of the stilt by means of a gland 210. The gland 210 compresses a packing 211 between itself and a shoulder in the plug 154 to provide a fluid seal between the pin 209 and the gland 210. The end of the pin 209 is tapered as at 212 to fit into a correspondingly shaped seat 213 at the junction of the passage 181 and the tube'182. A finger piece 214 is provided at the other end of the pin 209 to enable the pin to be turned easily. To lock the support members against relative movement, the pin 209 is screwed into the plug 154 until its tapered end 212 bears against its seat '213. In this position, fluid is unable to flow in either direction past the pin 209 and the support members, therefore, are locked in relatively immovable relation. To unlock the support member, it is necessary only to unscrew the pin 209 a distance sufficient to move the pointed end 212 out of engagement with its seat. 7 I,
In each of the described embodiments of the invention, the footsupporting plate or member is so mountedion one of the relatively movable vertical supporting members as to be in a substantially horizontal plane in its normal foot supporting position in which it extendsin a direction fore and aft of the support members, but is capable of being rocked about an axis transverse to the longitudinal extent of the foot supporting plate so as to condition the relatively movable supports for movement. The foot supporting plate is mounted to rock relatively to the support members in a substantially vertical plane extending fore and aft of the foot supporting plate about an axis transverse to the longitudinal extent of the foot supporting plate. This axis is between the toe and heel receiving parts of the foot supporting member.
The stilt constructions disclosed are representative of preferred forms of the invention, but it is intended that the disclosure be illustrative rather than definitive of the invention. The invention is defined in the claims.
1. In and adjustable stilt construction, first and second vertically extending support members mounted for vertical movement relative to one another; a ground engageable part on the lower end of one of said members; a foot supporting plate extending longitudinally in a direction fore and aft of said members and substantially horizontally when in its normal supporting position and having toe and heel receiving parts respectively at its front and rear ends; means mounting said foot supporting plate on the other of said support members for rocking relatively to said support members from and to its normal position in a substantially vertical plane extending fore and aft of said supporting plate and about an axis transverse to the longitudinal extent of said foot supporting plate and between said toe and heel receiving parts; control means normally preventing relative vertical movement of said support members; and means interconnecting said foot supporting plate and said control means for operating the latter in response to rocking of said foot supporting plate in said substantially fore and aft extending vertical plane to render said control means inoperative, and thereby permit relative vertical movement of said support members.
2. An adjustable stilt construction according to claim 1 in which said control means comprises a holding element, and means mounting said holding element on said other of said support members for movement into and out of holding engagement with said one of said support members.
3. An adjustable stilt construction according to claim 2 in which said holding element is a clamp engageable with said one of said support members.
4. An adjustable stilt construction according to claim 3 in which said clamp is formed with a cam surface engageable with said one of said support members.
5. An adjustable stilt construction according to claim 3 in which said holding element comprises a block, and said interconnecting means comprises a screw connected to said foot supporting plate and bearing against said block upon rocking of said foot supporting plate for pressing said block into clamping engagement with said one ofsaid support members. i 6. An adjustable stilt construction according to claim 1 in which said control means comprises a pawl movably mounted on said other of said support members, and a plurality of pawl engageable stops on said one of said support members. i
7. An adjustable stilt construction according to claim 1 inwhich said control means comprises a hydraulic piston and cylinder assembly including a piston connected to one of said support members and a cylinder connected to the other of said support members, and valve means connected to said foot supporting plate and being operable in response to rocking of the latter for selectively permitting and preventing relative movement of said piston and cylinder.
, 8. An adjustable stilt construction according to claim 1 including means for biasing said other of said support members upwardly relatively to said one of said support members.
- 9. An adjustable stilt construction according to claim 8 in which'said biasing means comprises a vertically extending coiled spring connected at its'upper end'to said one of said supportmembers and connected at its lower end to said other of said support members.
10. An adjustable stilt construction according to claim 8 in which said biasing means comprises means providing a chamber containing hydraulic fluid and entrapped compressed air.
References Cited in the file of this patent UNITED STATES PATENTS I r 1,418,685 Summers June 6, 1922 1,804,858 Burrell et al May 12, 1931 1,984,114 Collins Dec. 11, 1934 2,351,145 Pearson June 13, 1944 2,531,251 Bruno Nov. 21; 1950 2,705,637 Hranicka Apr. 5, 1955