US2775488A

US2775488A - Walking ladder construction

Info

Publication number: US2775488A
Application number: US513999A
Authority: US
Inventors: Claude O Wingrove
Original assignee: Individual
Current assignee: Individual
Priority date: 1955-06-08
Filing date: 1955-06-08
Publication date: 1956-12-25
Anticipated expiration: 1973-12-25

Description

Dec. 25, 1956 c, o, WINGROVE 2,775,488

WALKING LADDER CONSTRUCTION Filed June 8, 1955 v 2 Sheets-Sheet 1 Fig.

Fig.2

Claude 0. Wingro ve IN V EN TOR.

Dec. 25, 1956 c. o. WINGROVE WALKING LADDER CONSTRUCTION 2 Sheets-Sheet 2 Filed June 8, .1955

Claude 0. Wingrove INVENTOR.

BY ymeyfim WALKING LADDER CONSTRUCTION Claude 0. Wingrove, Tucu'mcari, N. Mex. Application June s, 1955, Serial No. 513,999

10 Claims. 01. 304-4 This invention relates generally to step-ladder constructions and is more particularly concerned with a convertible step-ladder construction whereby by the incorporation of wheels and manipulable levermembers a ladder may be moved to various positions by a person mounted on said ladder facilitating the usage thereof in picking fruit, painting etc.

A further object of invention in conformance with that set forth above is to provide on a conventional stepladder construction an auxiliary platform for accommodating the user of the ladder thereon and providing on oppositely disposed sides of vertical pivotal supports of a step-ladder manipulable force transmitting levers which when manipulated by the user of said ladder will provide a walking motion and permit ready maneuvering of said ladder.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

Figure l is a perspective view illustrating the step-ladder having provided thereon the novel structure permitting ready mobility of said ladder;

' Figure 2 is an enlarged fragmentary perspective view of a lower support foot portion of said ladder illustrating a sliding shoe and means for positioning the friction foot of the force transmitting lever thereon;

Figure 3 is a further enlarged sectional view taken substantially on line 33 of Figure 2; t

Figure 4 is a perspective view illustrating the sliding shoe attachable to the bottom portion of a support leg of a ladder;

Figure 5 is a side elevational view of the novel ladder when folded illustrating how the novel ladder is readily stored;

Figure 6 is a transverse sectional view taken substantially on line 66 of Figure 1 illustrating a platform at-- tachment thereon;

Figure 7 is an enlarged sectional view taken substantially on line 7-7 of Figure 6;

Figure 8 is a perspective view of the platform attachment shown in position in Figure 6; and

Figure 9 is a perspective view of a platform attachment for replacing the slidable platforms of Figures 1 and 6.

A ladder as indicated generally at 10 includes a support platform 12 having downwardly extending mutually

parallel flange portions

14 and 16 suitably secured on the underside. A pair of relatively parallel

fixed support standards

18 and 20 are secured at their upper ends 22 to one end of the

flanges

14 and 16, respectively, in any suitable manner. A plurality of horizontally disposed steps 24 extend between the

fixed supports

18 and 20 being secured therebetween in any suitable manner. Each of the

supports

18 and 20 include on suitable shaft members 26, wheels 28.

The

flanges

14 and 16 include on the ends opposite to nited States Patent 0 2,775,488 Patented Dec. 25, 1956 those which the ends 22 of the fixed standards are secured pivotally mutually

parallel legs

30 and 32 which are pivoted on the

flanges

14 and 16 by means of suitable pivot pins 34. Extending between the

pivotal legs

30 and 32 and being secured thereon in any suitable manner are

transverse brace elements

36 and 38.

Extending between

legs

18 and 30 and 20 and 32 are folding braces 40 which are pivoted on suitable pivot pins 42 on each of the legs, including two

links

44 and 46 which are pivoted together at 48, the link 46 including an overlying stop flange portion 50 which engages the upper portion of the link 44 and retains the

legs

30 and 32 in a relatively fixed position relative to fixed

legs

18 and 20, respectively.

The heretofore described structure, with the exception of the wheels 28 is conventional and that structure subsequently described including the wheels 28 heretofore mentioned constitutes applicants invention.

A transverse support shaft 52 extends through the

pivotal legs

30 and 32 having suitably journalled on opposite ends thereof spaced

washers

54 and 56 spaced by a suitable spacer sleeve 58 therebetween. The shaft 52 including on the end thereof a suitable flange retaining portion 60. As seen in Figure 3, only one end of the shaft 52 is disclosed in detail, however, the other end includes identical structure with the exception that the end of the transverse support shaft 52 may include thereon a suitable conventionalfastener (not shown). An elongated force transmitting leg 62 is provided on opposite sides of the ladder, each including on the upper side thereof an elongated bracket which includes a top portion 64 parallel to the force. transmitting leg being connected thereto on the upper edge of the force transmitting leg by means of a downwardly and outwardly extending flange portion 66 being secured thereon by a suitable fastener 68. As most clearly seen in Figures 2 and 3 the force transmitting leg 62 and the parallel flange 64 are. retained in position between the

washers

54 and 56 with the transverse support shaft 52 extending between the space formed by the force transmitting legs and the top portion 64 of the bracket element. Thus the force transmitting legs 62 may reciprocate relative to the transverse support shaft 52 within the limits of the attaching flange portion 66.

Each of the force transmitting legs include on their lower end portions bifurcated attaching ears 70 which pivotally support therebetween on a pivot pin 72 a shoe element 74 having a serrated undersurface 76 for providing good frictional contact with the ground. The opposite ends of the force transmitting legs have pivotally secured thereon by means of a pivot pin 76 bifurcated ear portions 78 of a pivotal lever 80 having suitable handles 82 attached on the end opposite the pivot 76. Secured on the outer sides of the legs 18 and 20 (only one being shown) are suitable outwardly opening bracket elements 84 which are engageable withthe underside of the force transmitting legs providing a suitable support for the same to rest therein.

A pair of vertically spaced

transverse elements

86 and 88 are disposed on the rear edge of the

pivot legs

30 and 32 supporting therebetween a reciprocable platform 90 which includes on the upper side a transverse raised edge member 92 and on the underside a similar transverse brace member 94 as seen in Figures 1 and 6. The plat-, form 9%) may bepositioned as shown in Figure .1 wherein the transverse element 92 will be in juxtaposition with the transverse brace element 86 on the ladder, the platform 0 providing an available space whereby the user of the ladder may face in the direction of the handles and by pulling alternately or simultaneously on one or both of the handles may move the same forward in a simulated Walking motion. The platform 90 of course may be moved into the position shown in Figure 6 when the ladder is not being moved as heretofore described. The platform 90 provides an available space as to the steps 24 whereby a person painting, picking fruit, etc., may use the same.

To facilitate the movement of the ladder in the manner just mentioned, the

pivotal legs

30 and 32 thereof include on the bottom end portion suitable slidable foot members 96 which include a lower slide portion 98 having upturned

ends

100 and 102 and

side flange portions

104 and 106 for accommodating therebetween the lower portion of the heretofore mentioned

legs

30 and 32. The foot members may be secured by suitable screws extending therethrough and into the bottoms of the legs. The flange 106 includes an outwardly extending fiange portion 108 having an upwardly extending raised portion 110 for extending between the serrations 76 on the friction members 74 on the bottom of the force transmitting legs.

The platform 90 rests on the horizontal step 24 in alignment with the

transverse support members

86 and 88, said platform 90 may be replaced by the platform member 112 which includes on the underside adjacent the forward edge a brace element 114 similar to brace 94 on the platform member 90, and includes on the rear edge secured to a transverse brace 116 on the upper side adjacent the rear edge thereof rearwardly facing U-shaped elements 118 having spaced leg portions 120 receiving therebetween the brace element 86 on the pivotal legs at any desired interval on the horizontal steps 24, said support platform 124 including a reciprocable support platform which may be the same as that indicated at 90 being supported by vertical support legs 126 having upper and lower

transverse support elements

128 and 130 operable to

transverse elements

86 and 88 secured directly on the ladder, said legs 126 including a pair of spaced clamping brackets 132 which have leg portions 134 to extend over the rear portion of the horizontal steps 24, as seen in Figure 6, said bracket portions 132 having transverse apertures 136 extending therethrough threadedly accommodating fastening screws 138.

Various positional directional terms such as front,

top, rear, etc., are utilized herein to have only a relative connotation to aid in describing the device and are not intended to be interpreted as requiring any particular orientation with respect to any external elements. The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. In combination with a ladder having a top platform, a first pair of downwardly extending mutually parallel support legs secured on one side of said top platform, a plurality of mutually horizontal steps extending between said support legs, a second pair of mutually parallel downwardly extending supporting legs secured on an opposite side of said top platform, wheels rotatably carried on the lower ends of said first pair of support legs; a pair of elongated force transmitting levers pivotally and slidably supported on said second pair of mutually parallel support legs, said force transmitting levers each including a lower portion engageable with the ground surface and an upper end portion pivotally secured to a handle portion, and a horizontal platform member supported in extending relationship between the first and second pairs of downwardly extending legs adjacent said handle portions.

2. In a combination as set forth in claim 1 wherein said force transmitting levers are pivotally and slidably supported on said second pair of support legs on an outwardly extending portion of a support shaft, each of said force transmitting levers including an elongated bracket slidably and pivotally receiving said outwardly extending portion of the support shaft.

3. A combination as set forth in claim 2 wherein said force transmitting levers each include a foot portion on the lower end thereof having a lower serrated surface for engaging the ground.

4. In the combination as set forth in claim 3 wherein said second pair of downwardly extending support legs each include a shoe element on the lower end thereof for slidably engaging the ground surface.

5. In the combination as set forth in claim 2 wherein said horizontal platform includes means thereon for clampingly engaging a transverse support portion extending between a pair of said downwardly extending support legs.

6. In combination with a ladder having a top platform, a first pair of downwardly extending mutually parallel support legs fixedly secured on one side of said top platform, a plurality of mutually horizontal steps extending between said support legs, a second pair of mutually parallel downwardly extending support legs pivotally supported on an opposite side of said top platform, movable legs pivotally supported between the fixed and pivotally supported support legs, and wheels rotatably carried on the lower ends of said first pair of support legs; a pair of elongated force transmitting levers pivotally and slidably supported on said second pair of mutually parallel support legs, said force transmitting levers each including a lower portion engageable with the ground surface and an upper end portion pivotally secured to a handle portion, and a horizontal platform member supported in extending relationship between the first and second pairs of downwardly extending legs adjacent said handle portrons.

7. In a combination as set forth in claim 6 wherein said force transmitting levers are pivotally and slidably supported on said second pair of support legs on an outwardly extending portion of a support shaft, each of said force transmitting levers including an elongated bracket slidably and pivotally receiving said outwardly extending portion of the support shaft.

8. A combination as set forth in claim 7 wherein said force transmitting levers each include a foot portion on the lower end thereof having a lower serrated surface for engaging the ground.

9. In the combination as set forth in claim 8 wherein said second pair of downwardly extending support legs each include a shoe element on the lower end thereof for slidably engaging the ground surface.

10. In the combination as set forth in claim 6 wherein said horizontal platform includes means thereon for clampingly engaging a transverse support portion extending between a pair of said downwardly extending support legs.

No references cited.