US1134437A

US1134437A - Tiltable-ladder structure.

Info

Publication number: US1134437A
Application number: US84401214A
Authority: US
Inventors: Ole H Blom
Original assignee: Individual
Current assignee: Individual
Priority date: 1914-06-09
Filing date: 1914-06-09
Publication date: 1915-04-06
Anticipated expiration: 1932-04-06

Description

0. H. BLOM.

TILTAB'LE LADDER STRUCTURE.

APPLICATION FILED JUNE 9, I9I4.

Patented Apr. 6, 1915 avwmdoz O/e H B o 2 SHEETS'SHEET 1.

THE NORRIS PETERS ca. FHOTC-LITHO.. WASHINGTON, D. c

0. H. BLOM.

TILTABLE LADDER STRUCTURE.

APPLICATION FILED JUNE 9. 1914.

1,134,437, Patented Apr. 6,1915,

2 SHEETS-SHEET Z.

l c U '(T 5/ Jv T 1 5 wuawboz wilbweooeo attoa'mw THE NORRIS PETERS c0, FHOTO-LITHO.. WASHINGTONv D. C.

UNITED TATE PATIENT @FFIQE.

OLE lI-I. BLOIVI, OF FAIRFIELD, WASHINGTON.

TILTABLE-LADDER STRUCTURE.

Application filed June 9, 1914.

To all whom it may concern Be it known that I, OLE H. BLOM, a citizen of the United States, residing at Fairfield, in the county of Spokane and State of Washington, have invented certain new and useful Improvements in Tiltable-Ladder Structure, of which the following is a specification.

This invention relates to improvements in tiltable ladder structure and has to do more particularly with a ladder structure mounted upon a base frame Which is portable on wheels.

It is one of the objects of my invention to provide a base frame on which a ladder is tiltably mounted for adjustment with re spect to the vertical both forwardly and backwardly and also laterally.

It is a further object of this invention to provide means for imparting tilting movement or adjustment to the ladder which will serve to lock the ladder in its tilted adjustment so as to afford a firm support for the user.

Other features and objects of the invention will be more fully described in connection with the accompanying drawings and will be more particularly pointed out and ascertained in and by the appended claims.

In the drawings :Figure 1 is a view in side elevation of a ladder structure embodying one form of my invention. Fig. 2 is an end view looking from the right of Fig. 1. Fig. 3 is an end View looking from the left of Fig. 1. Fig. 4 is a fragmentary detail elevation of a portion of one of the tilting means employed in my invention. Fig. 5 is a sectional view on line 55 of Fig. 4. Fig. 6 is a sectional view on line 6-6 of Fig. 3. Fig. 7 is a sectional View on line 77 of Fig 3. Fig. 8 is a detail view partly in section of aportion of a tilting means employed in my invention.

Like characters of reference designate similar parts throughout the different figures of the drawings.

As illustrated, I have shown my invention as including a base frame which may be a wheeled frame and the said base frame is substantially V-shaped comprising frame members 1 which converge and are secured together at 2. The free ends of the frame members 1 of the V-shaped base frame are mounted upon a bolster 3 which is supported upon bearing wheels 4:- The apex of the base frame may be held above the ground by Specification of Letters Patent.

Patented Apr. 6, 1915.

Serial No. 844,012.

a strut like support 5 which is reduced in length with respect to the radius of the wheels t so that the base or wheeled frame will normally be supported at an inclination to the horizontal, as illustrated more particularly in Fig. 1. The support 5 for the base frame may be secured to the latter, as indicated at 6, and a handle 7 may serve as a grip when it is desired to move the ladder structure from one point to another.

A ladder is indicated at 8 and the same is provided beneath its lower step 9 with an arcuate base 10 adapted to rest upon the bolster 3. As will be seen more particularly by reference to Fig. 7, the upper face of the bolster 3 is transversely convex and the lower face of the arcuate bar 10 is correspondingly concaved so that the tendency of the bar or base 10 will be to assume a normal position against displacement trans versely with respect to the bolster 3. However I provide means for tiltably connecting the ladder 8 with the bolster 3 and as shown, I provide the bar 10 with an enlarged opening 11 through which a pivot bolt 12 is extended. The pivot bolt 12 is held by supports 13 which are firmly secured to bolster 3 by bolts 14.

It will be seen that the supports 13 do not closely fit on opposite sides of the arcuate bar 11 and it will also be observed that the bolt 12 is considerably reduced in size with respect to the opening 11 so as thereby to afford a considerable range of movement of the ladder 8 both forwardly and backwardly, and likewise laterally of the vertical.

I will next describe the manner in which the ladder 8 is supported in different angular positions and the means by which the ladder is tilted laterally from the vertical.

A supporting frame is provided which may comprise

uprights

16 and 17 which are hinged or fulcrumed on the base frame members 1 near the bolster ends thereof for tilting movement of the upper ends of the upright toward and away from the vertical. The uprights are connected by an abutment board 18, to form a frame, and the abutment 18 is designed for sliding movement abreast of one face of an abutment board 19 which is secured to the ladder 8.

Abutments

18 and 19 are designed for a free sliding movement relatively to each other to permit of the ladder being tilted backwardly or forwardly, and also laterally. In order to hold the ladder in sliding engagement with the frame, I provide means which may com-' engagement with the teeth of rack 24 so that when the shaft 25 is rotated in one or another. of two directions, the worm 27 will engage the rack 24 to shift the latter and theladder 8 laterally from the vertical in adirect-ion corresponding to the direction in which'the shaft is rotated. The lladder will be, rocked upon the bolster 3, when'the ladder is tilted laterally, about the bolt 12 as its center and it will be under- 25 stood that a considerable degree of tilt of the upper end of the ladder can beeifected with the somewhat limited play afiorded between the bolt 12vand the opening 11. It is a special feature of my invention 80 that the means including the rack and worm, in this specific construction, which serves to tiltrthe ladder laterally, also serves to lock the ladder in its tiltedor normal up- :right position so as to afford the user a firmand secure support on which to climb. Any tendency of the ladder, or rather the arcuate base frame thereof to shift its position off from the bolster, 3 or out of alined relation therewith, may be counteracted by spring retainers which may be in the form of spring strips 28 which are secured to the bolster 3 and which extend .up-

wardly and rearwardly of the ladder and intoabutting relation therewith. The 46 spring retainers are disposed on opposite sides of the bolt 12, as will be clearly seen ,byreference to. Figs. 2 and 3. r. v

Abrace is provided for. tilting the ladder forwardly and rearwardly and the brace includes means for operating the same and preferably also locking such operating means in'its adjusted positions. As illustrated, the braceincludes a longitudinally :extensible brace structure comprising a brace member 29 which is slidable between brace members 30; Brace member 29 is chamfered, as at 31, and is provided with a connecting hook 32 whichis secured to saidbrace member 29 as indicated at 33. 'The hook 32 extends through a U-shaped bolt 34 which latter extends through atransyerse framemember 35 of the base frame 1. 7 i It will be seen from the foregoing, and by reference more particular to Fig. 8, that 651 means are provided for connecting the brace member 29 with the base frame 1 in such a' 7 ture which is in the form of brace bars 30,

is pivotallv connected at 36 to the supporting tilting frame,'and' specifically, through the abutment 18 thereof. Said brace bars 30 are slidably connected with the-brace member 29 byguiding straps 37 and 38,211 the lowerends of said bars, and a transverse gide 39 prevents relative movement; of the

members

29 and 30 out of alined relation near the upper end of brace member 2.9. In

order to render the members 30 more rigid, I provide braces 40 which extend up to the pivotal member 36 and which may engage the pintle of the pivot connection 36 if de sired] The bracemember 29 is vprovided with a rack which may be in the form of a strip 41 in which cavity tooth openings or sockets 42 are formed in proper spaced relatrons; Therack4l is shown secured to the] base member 29,-which'may be termed the rack member of the brace, by means of such as screws 43. A toothed wheel 44 is rota- .tively mounted for mesh engagement with the, rack openings 42 for efiecting extensibility and contract-ibility of the brace members comprising the brace structure, relatively to each other, such movement being in the direction of the length of said members. Said wheel 44 is non-rotatively but longitudinally slidably mounted upon a shaft 45 and I have shown the latter provided with a key 46 which slidably engages a suitable key-way formed in the wheel 44. Bear- .

ings

47 and 48 are mounted upon the brace bars-30 for supporting the shaft 45, it being understood that mesh engagement of the teeth of the wheel v44 withthe rack member A of the brace will serve to prevent; longitudinal displacement of the wheel 44 with respect to the rack member 29.. A bearing 49 is mounted on one of the brace bars 40 for supporting the extreme end of the shaft 45 'and the latter is provided with a crank 50 whereby rotative movement may be .im-

the shaft 45. The spring 53 normally acts to hold the locking polygonal end 52 in the locking member 51' so as to lock the shaft 45 against rotation. When'it is desired to lengthen or shorten the brace structure, to vary the tilt of the ladder 8,the shaft 45is shifted longitudinally to the left'ofFig. 5

to release the polygonal locking end 52 from the locking member 51 so that shaft 4.5 can be rotated.

It will now be seen that the brace structure can be extended and contracted. in the direction of its length to alter the inclination of the supporting frame and thereby tilt the ladder to the desired angle, and further, that irrespective of the forward or backward tilt of the ladder, the same can be tilted laterally in either direction and automatically held in its tilted adjustment.

If desired, an apron 55 may be easily mounted to overlap the connection of the brace structure with the supporting frame, as indicated more particularly in Figs. 1

and

lVhen it is desired to knock down the structure, bolt 12 and bolt 3% can be removed and likewise the pivotal connections can be made removable so that the parts can be attached without difiiculty.

It is believed that the novelty and utility of the device of my invention will be thoroughly understood from the foregoing di closure and while I have herein shown and described one specific form of my invention, I do not wish to be limited thereto except for such limitations as the claims may import.

I claim 1. A tiltable ladder structure comprising the combination with a base frame having one part fulcrumed at its lower end and supported at its upper end by a part extensible to vary the angle to the vertical of said first part, of a ladder pivoted at its foot to tilt sidewise in its own plane, and means substantially at the top of the base frame to support and guide the ladder in its sidewise tilt.

2. A tiltable ladder structure comprising the combination with a wheeled frame, a base frame having one part pivoted at its lower end on said wheeled frame and supported at its upper end by a part extensible to vary the angle to the vertical of said first part, a ladder pivoted at its foot to the wheeled frame to tilt sidewise in its own plane, and means substantially at the top of the base frame to support and guide the ladder in its sidewise tilt.

3. A tiltable ladder structure comprising in combination, a wheeled frame, a ladder, means loosely holding the foot of the ladder on the wheeled frame to permit sidewise tilt of the former in its own plane and also adjustment with respect to the vertical in directions angular to the plane of the ladder, adjustable means movably mounted on the wheeled frame for inclining the ladder with respect to the vertical and engaging the ladder near its upper end to support the latter in an inclined or substantially vertical position, and mechanism carried by the ladder and said movably mounted means for tilting the ladder sidewise in its own plane and locking the ladder in its tilted position, substantially as described.

In testimony whereof I affix my signature in presence of two witnesses.

OLE H. BLOM.

Witnesses:

HENRY TREEDE, SoU'rHwnLL lVILLMAN.

(Topics of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C.