US3701226A

US3701226A - Adjustable positionable structural device

Info

Publication number: US3701226A
Application number: US108094A
Authority: US
Inventors: Junius H Fulcher
Original assignee: Cooper Industries LLC
Current assignee: Cooper Industries LLC
Priority date: 1971-01-20
Filing date: 1971-01-20
Publication date: 1972-10-31
Anticipated expiration: 1989-10-31

Abstract

A structural device composed of lazy-tong frame members is adjusted to different positions by an enclosed piston, which exerts a force upon the structure in a location providing improved stability in the device while the position is being adjusted. Stabilizer arm members situated substantially parallel to the lazy-tong frame members assist in overcoming twisting forces, and consequent lateral movement, created when the position is being adjusted. The lazy-tong frame members and stabilizer arms are mounted at their ends to angle iron corner members which prevent the structure from locking up when such structure is in a collapsed position. Adjustable tension spring loading is provided at the mounting between the lazy-tong frame members and the angle iron corner members, to assist in overcoming and neutralizing inertia and friction in the structure.

Description

United States Patent Fulcher [54] ADJUSTABLE POSITIONABLE STRUCTURAL DEVICE [72] Inventor: Junius H. Fulcher, Houston, Tex.

[73] Assignee: Cooper Industries, Inc., Houston,

Tex.

[22] Filed: Jan. 20, 1971 [21] Appl. No.: 108,094

[52] US. Cl. ..52/l09, 182/63, 182/141 [51] Int. Cl ..E04g 1/22 [58] Field of Search ..l82/63,141,148, 69, 157;

[56] References Cited UNITED STATES PATENTS 2,625 ,443 1/1953 Sesenbaugh ..182/14l 1,859,830 5/1932 Kummel ..182/141 3,015,497 1/1962 Aldred ..182/17 2,798,641 7/1957 Coddington ..182/l41 1,135,440 5/1915 Javal ..254/122. 2,767,812 10/1956 Boger ..52/l09 Oct. 31, 1972 990,399 5/1911 Smith ..245/277 Primary Examiner-Reinaldo P. Machado Attorney-Owen & Owen [5 7] ABSTRACT A structural device composed of lazy-tong frame members is adjusted to different positions by an enclosed piston, which exerts a force upon the structure in a location providing improved stability in the device while the position is being adjusted. Stabilizer arm members situated substantially parallel to the lazytong frame members assist in overcoming twisting forces, and consequent lateral movement, created when the position is being adjusted. The lazy-tong frame members and stabilizer arms are mounted at their ends to angle iron corner members which prevent the structure from locking up when such structure is in a collapsed position. Adjustable tension spring loading is provided at the mounting between the lazy-tong frame members and the angle iron corner members, to assist in overcoming and neutralizing inertia and friction in the structure.

3 Claims, 9 Drawing Figures P'A'TENTEDH'BI I 1912 r 3.701.226

SHEET 3 0F 3 PWJ Wm & Mme

ATTORNEYS ADJUSTABLE POSITIONABLE STRUCTURAL DEVICE BACKGROUND OF THE INVENTION DESCRIPTION OF THE PREFERRED EMBODIMENT In the drawings, the letter D designates generally an The field of this invention is adjustably positionable adjustably positionable structural device of this invenstructural devices such as platform lifts, scaffolding, extendible crane booms, structural members and the like.

The prior art, such as US. Pat. No. 3,053,351, taught the use of structural devices composed of lazy-tong frame members. However, such structural devices if sufficiently large suffered diminished stability due to improper resolution within the device of the forces applied thereto, causing twisting and lateral movement when the position of the structural device was being changed. Further, the devices required that relatively large forces be applied to adjust the position of such devices, in order to overcome the friction in the connections between lazy-tong frame members, and the inertia of the structure. When the device was initially fully collapsed, it had a tendency to lock-up, due to the inertia of the device and the friction between frame members at the connections.

SUMMARY OF THE INVENTION With the present invention, an adjustably positionable structural device is provided comprising a plurality of frames composed of lazy-tong frame members, connected at their ends to angle iron corner members which prevent the structure from locking up when in a collapsed position, and preferably with adjustably tensioned spring clips positioned at the connection between the frame members and the corner members, to assist in overcoming and neutralizing inertia of the device and friction between frame members at the connections. The force required to adjust the position of the device is generated by a cylinder and piston situated interiorly with respect to the frames, with the force created by the expanding piston transmitted to cables which are attached to the frames at suitable positions to apply the forces to the frames to increase the stability of the device during movement.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevational view of an adjustably positionable platform according to the present invention, in a raised or elevated position;

FIG. 2 is an elevational view of a platform adjusted to its fully collapsed position;

FIG. 3 is a cross-sectional view taken along the line 3-3 of FIG. 2;

FIG. 4 is a cross-sectional view taken along line 4-4 of FIG. 2;

FIG. 5 is an isometric view of the moving force generating portion of the adjustable structural device of the present invention;

FIG. 6 is a cross-sectional view taken along the line 6-6 of FIG. 3;

FIG. 7 is a cross-sectional view taken along the line 7-7 of FIG. 4;

FIG. 8 is an enlarged sectional view illustrating in detail the portion circled in FIG. 1 and having the numeral 8 designating same; and

FIG. 9 is a cross-sectional view taken along the line 9-9 of FIG. 8.

tion. As will be explained in detail, the device D is movable to plural adjustable positions by application of suitable adjusting forces, and is suitable for use as a platform, scaffolding, elevator, extendible crane boom, structural member or the like.

In FIG. 1, the device D used as a movable platform is shown, comprising a platform T with an associated guard rail G, positioned atop a plurality of frames F, each comprising plural lazy-tong frame members 20 pivotally connected at their

ends

21 and 22 to a corner member 30, and positioned atop a base member B.

The platform T comprises a work surface 10, upon which a worker or rider and cargo can be positioned, a cruciform support member 11, and a plurality of tracks 12, each mounted to the support member 1 1.

Each of the lazy-tong frame members 20 is pivotally connected at its center to a corresponding lazy-tong frame member 20a and at its

ends

21 and 22 to corner members 30, in a manner to be later discussed. The lazy-

tong frame members

20 and 20a may be of several configurations, such as angle iron members, rods, or flat bars, or any of the various configurations disclosed and discussed in US. Pat. No. 3,053,351. A plurality of stabilizer bars 25 are positioned substantially parallel to selected ones of the lazy-tong frame members 20, such stabilizer bars 25 being pivotally connected at their centers to a corresponding stabilizer bar 25a, and at their ends to corner members 30 to enhance the stability of the device D in a manner to be later discussed.

A plurality of clevis-shaped members 33 are mounted with respect to a plurality of corner members 31 atop each of the frames F, and a like plurality of clevis-shaped members 34 are mounted with respect to a plurality of corner members 32 at the base of each of the frames F.

The clevis-shaped members 34 each enclose an arm 41 of a cruciform support member 44 of base B. An outrigger, or support leg, 42 is hingably mounted with respect to each arm 41 of the support member, and has a base pad 43 hingably mounted with respect to such leg. The pad 43 engages the surface upon which the device D is to be positioned for operation, and provides a broad support base as will later be discussed for the frame member F. A dolly 50 with attached wheels 51 also comprises a part of the base member B, and facilitates movement of the device D from one location to another.

A cylinder with an associated piston P, to which a bridle 60 is mounted, is situated interiorly with respect to the frame members F, and creates the movement required to adjust the position of the device D in a manner to be described.

A plurality of pulleys 61, each of which is mounted with respect to an arm 65 of the bridle 60, and over which a cable or rope 62, affixed at one end to eyelets formed in a plurality of flanges 63 extending from the arms 41, and at the other end to one of the intermediate corner members 30, impart the motion of the piston P with respect to the cylinder C to the frame members F.

In FIG. 2, the device D is shown in a collapsed position, with like parts bearing like reference numerals to FIG. 1. To preserve clarity in the drawings, several reference numerals have been omitted from FIG. 2. The piston P is substantially completely enclosed within the cylinder C, and each of the frame members F is substantially fully collapsed with the pivotally connected lazy-tong frame members and 20a being spaced their maximum angular displacement with respect to each other about their pivot center connection. When the device D is in the collapsed position, each of the corner members is in contact at an upper surface 30a and a lower surface 30b with the lower surface and upper surface, respectively, of the adjacent corner members, stacking to form a solid column of such corner members and displacing the pivotally connected

ends

21 and 22 of the lazy-tong frame members 20 relative to the pivotally connected ends of adjacent frame members. The displacement of the pivotally connected

ends

21 and 22 prevents adjacent pivotally connected ends from coming into engagement with respect to one another and due to such engagement causing the device D to lock-up in the collapsed position, whereby the pivotally connected ends cannot move freely with respect to one another in response to the movement of the piston P, and thus are resistant to a change in position of the device D.

The cables 62 are connected to a respective intermediate corner member 30, intermediate the upper and lower ends of the frame members F so that the force created by the motion of the piston P, when applied to the corner members 30, resolves itself into a vertical component, which moves the corner member 30 upwardly when the device D is being moved upward, and correspondingly downward when the device D is being moved downward, and two rectangular horizontal components which are applied to the ends of the lazy-tong frame members causing such frame members to move pivotally with respect to one another as the position of the device is being changed. Location of the cable attachment at corner members 30 intermediate the ends of the frames F also permits use of a smaller, and consequently less expensive, cylinder C and allows further collapse of the device D to a lower position, permitting access to the platform at a lower height, and occupying a smaller space when the device D is moved from one position to another as will later be described.

Should the rectangular horizontal force components be unequal, a torsional or twisting force is created, tending to rotate the frames F and platform P relative to the base B. To assist in overcoming such twisting force, the

stabilizer bars

25 and 25a are positioned parallel to selected

frame members

20 and 20a according to the dimensions, size, and particular use of the structural device D, to gain additional structural support against such force.

When the device D is in the collapsed position (FIG. 2), it may be moved from one position to another by means of the dolly 50. The wheels 51 may, if desired, be positioned on tracks to facilitate such movement. The device D may also be placed in a truck, trailer or the like and moved from one job site to another. If the device D is used as a platform, a ladder or steps could be attached to the platform T to allow the user to mount the platform T more easily.

In FIG. 3, the structure of the base B, whereby a broader and more stable support for the device is provided, is illustrated. The dolly 50 itself provides a sufficiently stable when the device D is in the collapsed position (FIG. 2). However, when the position of the device D has been adjusted to a suitable height, a broader and thus more stable base is desirable.

A plurality of wheels 360 through 36d are positioned within clevis-shaped members 34a through 34d on axles 38 (FIG. 6), and ride upon an upper surface 50a of the dolly 50 (FIG. 3'). The wheels 36a through 36d are positioned within grooves in corresponding arms 41a through 41d of cruciform member 44, and move within such grooves to allow inward and outward movement of the lower corner members 32a through 32d, and thus the lower ends of the frames F, with respect to the upper surface 50a and the dolly 50 when the position of the device D is being adjusted. Flanges 63a through 63d, in which eyelets for the passage of the cable 62 are formed, are positioned on an upper surface of the arms 41a through 41d, respectively, and the cylinder C, within which the piston P is positioned, is positioned at the center of the base member 44 where the arms 41a through 41d intersect. The

support legs

42a, 42b, 42c and 42d are hingeably mounted by pins, bolts or other suitable means, illustrated as 45a and 45b, at the ends of

arms

41a, 41b, 41c and 41d, respectively outside of the dolly 50. The

support pads

43a, 43b, 43c and 43d are hingeably mounted by pins, bolts or other suitable means 46a to the ends of

support legs

42a, 42b, 42c and 42d, respectively, opposite the dolly 50. The pads 43 thus engage the surface upon which the device D is positioned at a greater distance from the device D than the dolly 50, providing a broader support base for the device D, thereby rendering the device more stable when such device is at an elevated position (FIG. 1), particularly if the surface upon which the device D is positioned is rough or uneven.

In FIG. 4, the pulleys 61 mounted to the arms 65 of 'the bridle 60 extending outwardly with respect to a v stem S of the piston P are shown. A plurality of

wheels

37a, 37b, 37c and 37d are positioned within

clevisshaped members

33a, 33b, 33c and 33d axles 39 (FIG. 7) and engage the lower surfaces 13a, 13b, 13c and 13d of the tracks 12a, 12b, 12c and 12d (FIG. 4), respectively, moving within such tracks to allow inward and outward movement of the upper corner members 31a through 31d, and thus the upper ends of the frames F with respect to the tracks 12 and the platform P, when the position of the device D is being adjusted.

In FIG. 5, the means for generating the forces required to adjust the position of the device D is shown, comprising a cylinder C mounted with respect to the arms 41 of the base member 44, containing a piston P whose stem S has attached at an end opposite the cylinder C a bridle 60 comprising a plurality of outwardly extending flanges 65a through 65a' to which are mounted pulleys 61a through 61d, respectively. A plurality of cables 62a through 62d are respectively attached to eyelets in the flanges 63a through 63d in the arms 41a through 41d of the base member 44, and to intermediate corner members 30.

The piston P may be pneumatically, hydraulically, electrically or mechanically moved from one position to another to adjust the position of the structural device. If pneumatic or hydraulic means are used, a

check valve and line bleeder may be included for safety purposes.

Movement of the piston P caused by suitable means set forth above causes the stem S and bridle 60 to-correspondingly move, exerting by means of pulleys 61a through 61d, and cables 62a through 62d, respectively, corresponding forces on the intermediately located corner members 30 of the frames F, thereby adjusting the position of the device D to the desired position.

In FIG. 8 and FIG. 9, the mounting of lazy-tong frame members and 20a with respect to the corner member 30 is illustrated. An opening 28 is formed in the ends 21 (not shown) and 22 of each of the

frame members

20 and 20a, and a similar opening 30c (in each wall of the angle iron corner member 30) is formed by drilling or other suitable techniques. Another opening 29 is also formed in the

ends

21 and 22, and a corresponding pair of

openings

30d and 30e are formed in the angle iron corner member 30. A suitable attaching device 80 which could be for example a bolt, pin, brad, cotter key or the like is inserted through the

openings

28, 30c and 28a to attach the

frame members

20 and 20a to the corner member 30. A spring 70 is then tensioned and inserted with one end in the opening 29 and the other end in opening 30d, and another spring 70a is tensioned and similarly inserted in the openings 29a and 302. The force in the tension springs is designed to overcome the frictional forces between individual frame members, and between frame members and corner members, as well as the inertia in the device D, all of which tend to resist the forces applied to the device D to adjust its position.

The size of the spring 29, and the amount of tension applied, could be varied in accordance with the position of the corner member to which such spring 29 is mounted. For example, the size and the tension of the spring 29 at the lower corner members 32 should be somewhat larger than that of the springs 29 located at the intermediate corner members 30 and at the upper members 31. Also, similar spring tensioning arrangements could be accomplished with respect to the stabilizer bars 25.

' In the operation of the present invention as an adjustably positionable platform, the user desiring access to an elevated position places himself and the tools and/or materials he requires on the surface 10 of the platform T, and either a co-worker or the user actuates the motor or other suitable device to cause the piston P to move with respect to the-cylinder C until the platform T is at a suitable height. The frames F supporting the platform T provide support for such platform and make the platform self-supporting and stable even if the user moves about on the platform. The device D offers a safety feature of protection against an overload condition, since if the platform T is overloaded, the piston P and the cylinder C cannot generate sufficient force to overcome the overload weight on the platform T, and the platform T does not move. Another safety feature offered by the device is that should the piston P or cylinder C suffer a leak when the device D is at an elevated position, the device will not collapse. Rather, the piston P will slowly be compressed into the cylinder C, due to the weight on the platform T, allowing a slow, gradual safe lowering of such platform to the collapsed position (FIG. 2).

Although the device D has been illustrated as comprising four frames F of lazy-tong frame members, forming a square cross-section, other configurations of frames are equally suitable for use in the device D of the present invention, for example a triangular arrangement of three frames of lazy-tong frame members, or a rectangular arrangement of four frames.

In addition to serving as an adjustably positionable platform as illustrated in the drawings, the structural device D of the present invention is useful as numerous other types of structural devices. For example, the device D of the present invention may be used to expand horizontally and serve as an extendible crane boom, temporary bridge or the like. The device D with a platform T can also be used as an elevator. A plurality of structural devices D may be situated with boards or runways extending therebetween to serve as highly safe and stable scaffolding. The device D may be used to temporarily replace damaged utility pole or other structural member while a replacement pole or member is being put into position.

The foregoing disclosure and description of the invention areillustrative and explanatory thereof, and various changes in the size, shape, and materials as well as in the details of the illustrated construction may be made within departing from the spirit of the invention.

I claim:

1. An adjustably positionable structural device for use as a platform lift, scaffolding, extendible crane boom, structural member or the like, comprising:

a. a plurality of frames, each of said frames comprising a plurality of lazy-tong frame members, each of said members being pivotally mounted at its center to another frame member and pivotally connected at its ends to other members;

b. force generating means for generating a force to adjust the position of said frames relative to each other;

0. means for connecting said force generating means to at least oneof said frames at a position intermediate the ends thereof; and

d. a plurality of stabilizer bars, each bar being pivotally mounted at its center to another stabilizer bar, and pivotally connected at its ends to other stabilizer bars, and situated substantially parallel to a lazy-tong frame member to assist in overcoming torsional forces created when the position of said device is being adjusted.

2. An adjustably positionable structural device for use as a platform lift, scaffolding, extendible crane boom, structural member or the like, comprising:

c. means for connecting said force generating means to at least one of said frames at a position intermediate the ends thereof; and

d. said force generating means including:

1. a piston located interiorly of said frames; 2. a bridle mounted with respect to said piston; 3. a pulley mounted with respect to said bridle;

4. means for adjusting the position of said piston, thereby generating the force required to adjust the position of said device; and

5. a cable engaged with said pulley to impart to said frames the force being generated by said piston, said frames being disposed exteriorly of said force generatingmeans.

3. An adjustably positionable structural device for use as a platform lift, scaffolding, extendible crane boom, structural member or the like, comprising:

c. means for connecting said force generating means to at least one of said frames at a position intermediate the ends thereof;

d. connecting means for connecting said frames at said ends of said members and comprising an angle iron corner member, said corner member displacing the pivotally connected ends of the frame members of a frame relative to each other to thereby preclude said device from locking up in the collapsed position; and

. a plurality of stabilizer bars, each bar being pivotally mounted at its center to another stabilizer bar, and pivotally connected at its ends to respective ones of said angle iron corner members, and situated substantially parallel to a lazy-tong frame member, said stabilizer bars and said angle iron corner members assisting in overcoming torsional forces created when the position of said device is being adjusted.

Claims

1. An adjustably positionable structural device for use as a platform lift, scaffolding, extendible crane boom, structural member or the like, comprising: a. a plurality of frames, each of said frames comprising a plurality of lazy-tong frame members, each of said members being pivotally mounted at its center to another frame member and pivotally connected at its ends to other members; b. force generating means for generating a force to adjust the position of said frames relative to each other; c. means for connecting said force generating means to at least one of said frames at a position intermediate the ends thereof; and d. a plurality of stabilizer bars, each bar being pivotally mounted at its center to another stabilizer bar, and pivotally connected at its ends to other stabilizer bars, and situated substantially parallel to a lazy-tong frame member to assist in overcoming torsional forces created when the position of said device is being adjusted.

2. An adjustably positionable structural device for use as a platform lift, scaffolding, extendible crane boom, structural member or the like, comprising: a. a plurality of frames, each of said frames comprising a plurality of lazy-tong frame members, each of said members being pivotally mounted at its center to another frame member and pivotally connected at its ends to other members; b. force generating means for generating a force to adjust the position of said frames relative to each other; c. means for connecting said force generating means to at least one of said frames at a position intermediate the ends thereof; and d. said force generating means including:

2. a bridle mounted with respect to said piston;

3. a pulley mounted with respect to said bridle;

3. An adjustably positionable structural device for use as a platform lift, scaffolding, extendible crane boom, structural member or the like, comprising: a. a plurality of frames, each of said frames comprising a plurality of lazy-tong frame members, each of said members being pivotally mounted at its center to another frame member and pivotally connected at its ends to other members; b. force generating means for generating a force to adjust the position of said frames relative to each other; c. means for connecting said force generating means to at least one of said frames at a position intermediate the ends thereof; d. connecting means for connecting said frames at said ends of said members and comprising an angle iron corner member, said corner member displacing the pivotally connected ends of the frame members of a frame relative to each other to thereby preclude said device from locking up in the collapsed position; and e. a plurality of stabilizer bars, each bar being pivotally mounted at its center to another stabilizer bar, and pivotally connected at its ends to respective ones of said angle iron corner members, and situated substantially parallel to a lazy-tong frame member, said stabilizer bars and said angle iron corner members assisting in overcoming torsional forces created when the position of said device is being adjusted.

5. a cable engaged with said pulley to impart to said frames the force being generated by said piston, said frames being disposed exteriorly of said force generating means.