US3176792A - Movable work platform - Google Patents

Description

April 6, 1965 D. c. OLSON MOVABLE WORK PLATFORM 5 Sheets-Sheet 1 Filed Feb. 28, 1963 INVENTOR. DAVID C. OLSON BY Agent April 6, 1965 D. c. OLSON 3,176,792

MOVABLE WORK PLATFORM Filed Feb. 28, 1963- 5 Sheets-Sheet 2 82 i f l 1 no m INVENTOR.

DAVID C. OLSON BY Z Agent April 6, 1965 D. c. OLSON ,1 6,

MOVABLE WORK PLATFORM Filed Feb. 28, 1963 s Sheets-Sheet a FIG. 2B

INVENTOR. DAVID C. OLSON 2 Agent MOVABLE WORK PLATFORM Filed Feb. 28, 1963 5 Sheets-Sheet 4 Z 5, m 2 N O u m m 9 Q g INVENTOR.

DAVID C. OLSON 2 Agent April 6, 1965 D. c. OLSON 3,176,792

MOVABLE WORK PLATFORM Filed Feb. 28, 1963 5 Sheets-Sheet 5 INVENTOR. DAVID C. OLSON Agent United States Patent 3,176,792 MOVABLE WORK PLATFQRM David C. Olson, Burbank, Califi, assignor to Lockheed Aircraft Corporation, Burbank, Calif. Filed Feb. 28, 1963, Ser. No. 261,634 4 Claims. (Cl. 182-2) This invention relates to a work platform which is universally movable in a manner such that it is capable of being moved vertically, horizontally, or laterally without deviation of the platform thereof from a horizontal plane.

Prior to the present invention, it has been extremely dillicult for workmen to gain easy access to otherwise inaccessible regions in performance of various tasks. For example, electrical repairmen, aircraft maintenance men, and a multitude of other occupations require that the workmen be ascended to otherwise inaccessible regions. It is many times necessary that movement in six degrees of freedom be provided in order that the workmen can gain full access to the locations at which their work must be accomplished.

It is a principal object of the present invention to provide means whereby easy access to otherwise virtually inaccessible locations may be accomplished.

Another object of this invention is to provide a work platform which is universally movable through six degrees of freedom and is capable of transporting workmen and equipment to given locations otherwise diflicult or impossible to reach.

A further object or" the invention is to provide a movable work platform which always remains in an upright position while being moved vertically, horizontally, or laterally.

A still further object of this invention is to provide a universally movable work platform which includes a high structural integrity, a stable base for operation and easy controllability from either a base or a movable platform position.

Other objects of invention will become apparent from the following description, considered in view of the accompanying drawings, in which:

FIGURE 1 is an elevational view of the invention with the work platform in an extended position;

FIGURES 2A, 2B and 2C are cutaways cooperatively illustrating a complete elevational view as taken along lines 2--2 of FIGURE 1;

FIGURE 3 is a cross-sectional view of atypical pivotal structure as taken along lines 3-3 of FIGURE 1;

FIGURE 4 is a cross-sectional view taken along lines 4-4 of FIGURE 2A, partially cutaway to illustrate the upper roller and track configuration of the.

basket assembly; and

FIGURE 5 is a cross-sectional View taken along lines 55 of FIGURE 2A and partially cutaway to illustrate the lower track and roller and the rack and pinion configurations.

The invention, in its more general aspects, is directed to a work platform comprised of a base, which may include outrigger assemblies for stability purposes, a

basket assembly or work platform adapted to hold and transport workmen and equipment, a pair of parallelogram linkages having ends respectively pivotally mounted to the base and to a basket support assembly with their adjacent ends pivotally connected to a stabilizer assembly. Each of the parallelogram linkages includes an actuator means for raising and lowering its individual linkages.

Referring now to the drawings, wherein similar reference numerals are used to designate similar elements throughout the various views shown, the numeral iii designates the overall universally movable work platform. An

opposite arms.

3 ,176,792 Patented Apr. 6, 1965 elongated base or chassis 11 usually is provided with a conventional caster assembly 12 on each of its 4 corners. The casters 12 may be provided with locks (not shown) in order to stabilize their positions during operation when such is desired. A tow bar 13 may be provided at one end of the base Ill .for moving same. Although the specific construction of the base 11 forms no part of the present invention, it is usually constructed from various structural beams in a generally rectangular pattern with lateral and diagonal members sufiicient to support the weight of the movable structure. It is particularly desirable that stiffening members be provided approximately intermediate of the base to prevent sagging of the beams in that vicinity.

A pair of outrigger assemblies 15a and 15b are pivotally mounted by conventional means at positions 16a and 16b approximately centrally oil the base '11. Such outrigger assemblies usually include brace members 17, also pivotally mounted to the base 11 and adapted to retain the outrigger assemblies in their extended positions. These assemblies may, however, be rotated into a stowed position such as illustrated by the dotted line position in FIGURE 1. At the outer extremity of each assembly, a jack 18:: or 18b is provided. This jack, shown herein as being of a hand-operated worm gear type, is jacked downward to engage the ground and provide platform stability during operation.

A step assembly 20 is sometimes constructed intermediately of the base 11 to provide easy access to the basket assembly (hereinafter describedywhen the basket assembly is in its lowered position.

A first parallelogram linkage is comprised of four arms, each of the respective arms 31a and 31b and 32a and 3272 being left and right hand duplicates of one another. In their preferred embodiment, the arms 31a and 3111 are constructed of a cylindrical tube, bent at the position indicated as 33, and a pair of flanges 34 welded to opposite sides thereof. A cavity 35, open at its upper extremity, is defined between the fianges34. This provides for a nesting of the lower extremity of a second parallelogram linkage arm, hereinafter described, when such arm is in its extreme lowered position. The lower extremity of the arms 31a and 3111 include a pair of mounting flanges 36 which are pivotally mounted upon a bracket 37 afiixed to the base 11. The parallelogram linkage 39 includes a rigid brace structure generally indicated by the numeral 38 which retains the arms 31a and 31b in a parallel relationship and which is capable of accepting compression loads.

Each of the arms 32a and 32b includes a pair of fianges 39 at its lower extremity which are pivotally mounted to a bracket 40 aflixed to the base 11. Each also includes a pair of flanges 41 at its upper extremity which are pivotally mounted to a stabilizer assembly as hereinafter described. The sectional illustration of FIG- URE 3 shows a pivotal mounting assembly, the bearing and pin construction of which is generally typical of all pivotal connections in major assemblies utilized herein. Therein, the flanges 39.straddle a boss 42 formed upon the bracket 4t). A journal bearing 43 is concentrically disposed within the boss 42 in a conventional manner and a bolt 44 is disposed therethrough to connect the same with the ends of the flanges 39 through suitable perforations. The bolt is retained in this position by means of a nut 45; In the immediately illustrated assembly of arms 32a and 3212, a terminal bracket 46 is also retained by the bolt 44. A pair of tie rods 47 are adjustably connected to the terminal brackets 46 by means of terminals 48. The tie rods 47 run diagonally from the bottom of each arm 32a and 32b to the top of the These tie rods are adapted to accept tensile loads applied to the arms 32a and 32b.

A stabilizer assembly 50, preferably comprised of a series of-tubular members forming a triangle when viewed in verticaly section, and interconnected in a conventional manner, substantially as illustrated in FIGURE 2, is pivotally mounted to the upper extremities of the. arms 31a and 31b and the arms 32a and 32b.

A second parallelogram assembly 60, similar to the first assembly 30, includes a pair of arms 61a and 61b and a pair of arms 62a and 62b. Arms 61a and 61b are retained in their. parallel position and rigidly supported by a. rigid brace assembly 63 adapted for the acceptance of compression loads. Each of the latter arms also includes a pair of flanges 64 on its lower extremity which are. pivotally mounted to the stabilizer assembly 50 and the flanges 34, in the manner illustrated in cutaway sec tion inFIGURE 2. The upper extremity of each arm 61a and 61b includes a pair of flanges 65 adapted for a pivotal mounting.

Similarly, each of the arms 62a and 62b includes a pair of. flanges 66 at its lower extremity, the flanges being pivotally mounted to the upper extremity of the stabilizer assembly. 50. The upper end of each arm similarly includesapair of flanges 67 which are adapted for pivotal mounting. A pair of tie rods 68 diagonally interconnect opposite ends of the arms 62a and 62b for the acceptance of tension loads and are connected in the same manner as are tie rods 47, heretofore described.

A basket support assembly 70, generally comprised of a series of Weldedpipes, as particularly illustrated in FIG- URE 2, includes ,at its upper extremity a tubular member 71 which is generally rectangular in cross-section (FIG- URE. 4) and a track or channel member 72 at its lower extremity. A gear rack 73 is rigidly aflixed to and supported with respect to the track 72 by a pair of support members 74 and 75, as more particularly illustrated in FIGURE 5. Each corner of the basket support assembly 70-is mounted to the various flanges 65 and 67 for pivoting with respect thereto.

A basket assembly 80 is rigidly constructed with four sides, tworof which are illustrated in FIGURES 1 and 2, respectively, by numerals 81 and 82. A. front side thereof, illustrated by the numeral 83, usually includes a door (not shown) of conventional construction through which workmen may enter and leave the basket assembly 80. A rigid floor 84.is provided at the lower extremity of the assembly.

A's more specifically illustrated in FIGURE 4, a bracket 84; having a roller 85 mounted for rotation therein, is connected to the basket side 82 and is disposed about the tubular member 71 such that the roller 85 bears against and rolls over one side of the tubular member 71. The weight of the basket assembly 80 is exerted generally in the direction of arrow 86 in FIGURE 1. Hence, a force is exerted against the tubular member 71 by the roller 85. Simultaneously, a roller 87 mounted upon the lowerextremity of the basket assembly 81 bears and rolls against the track 72, the force being transmitted in,the,direc tion of .arrow 88. A separate roller 89,-also mountedupon. basket 81, rolls on the lower surface of the track 72 to limit theverticalpoistioning of the basket assembly 80.with.respect to the basket support assembly 70.

A c r ank 90 mounted for rotation upon the basket assemblylStLhas an automatic disengagement means 91 of standard spring loaded. socket configuration attached thereto, This means engages, when the crank 90 is presseddownward, a matching unit upon a shaft 92. The

45,. trols the movement of the linkage 30 and an actuator assembly 104 controls the linkage assembly 60.

Each such actuator assembly is preferably comprised of a pair of ball screw actuators. For example, the actuator assembly 94 includes a pair of ball screw actuators Q5 and 96. These actuators may be of a commercially available type available from the Saginaw Steering Gear, Division of General Motors Corporation, Saginaw, Michigan, and identified as a Recirculating Ball Screw. A standard and commercially available drive motor 97, preferably of an electric type, in a typical application and as applied herein, includes a shaft driving a pair of miter gears in the housing indicated as 98. The miter gears drive a pair of worm gears in the housings 99a and 9%. These worm gears, in turn, engage and drive the ball screw actuators 95 and 96. The ball screw actuators 95 and 96 are usually covered with a pair of telescoping tubes 1% and 161 for purposes of cleanness. The actuators 95 and 96 are pivotally connected to a pair of brackets I92 and 103 rigidly affixed to the base 11. Their upper extremities are similarly pivotally attached to the stabilizer assembly 50. Thus, the extension or retraction of the actuator assembly 94 results in a raising or lowering of the parallelogram linkage 30. In such case, the arm pairs 31a and 31b and 32a and 32b remain parallel to one another at all times, their relative distance from one another, however, increasing and decreasing, respectively, as the assembly is raised and lowered.

The actuator assembly 104 includes a pair of ball screw actuators 105 and 106 motor driven in the same manner as are the actuators 9'5-and 96. The lower extremities of the actuators 105 and 106 are pivotally mounted to the upper structural member of the stabilizer assembly 50 and the upper actuator extremities of the actuators 105 and 106 are pivotally mounted to the upper structural member of the stabilizer assembly 50 and the upper actuator extremities are pivotally mounted to the basket support assembly 70.

Extension of the actuators 105 and 166 causes the linkage arms 6*1a-6 1b and 62a62b to diverge in parallel relation with a resultant raising of the arms and the basket assembly 81 therewith.

A pair of control panels 107 and 168 are respectively mounted upon the base 11 and within the basket assembly 81. Each such panel includes conventional switch means for individually raising or lowering each of the parallelogram linkages 30 and 60 through the actuationof their associated actuator assemblies.

The electrical system is of a conventional and standard configuration. It is to be understood that operation of switches upon the control panels cause the motors to become operative in clockwise or counter-clockwise motion for controlling extension or retraction of the various actuators. Similarly, the limit means 'act conventionally to cut off the power supply in the event of structural inter'ference.

A conventional limit switch is attached adjacent to or upon the lower extremity of the actuator 95, as typically applied, to prevent movement of the first linkage 30 be yond a predetermined position.

Similarly, 'a iimit switch 113, actuated by a cable 114 is provided upon the arm 31a.

Operationally, when particular stability of operation is required, the outrigger assemblies 15a and 15b are swung outwardly from their stowed positions and the jacks 18a and 18b are engaged with the ground in order to provide lateral stability. At this time the basket assembly 81 is usually in its extreme downward position, as illustrated by the dotted line basket position in FIGURE 1. The operator enters the basket assembly by means of the steps '20. He is elevated to the desired ultimate position through the operation of the control panel 108 or, alternately, the operation can be controlled from the ground by means of the control panel 107. Assuming that the ar /ease ultimate position desired is that illustrated in FIGURE 1,

the operator utilizes the control panel switches to cause the extension of the actuators of assembly 9 and 1M, either individually or simultaneously. The actuation is continued until such time as the basket assembly at atrives at its desired vertical and horizontal position. It will be understood that horizontal positioning, i.e., movement forward and rearward with respect to the base 11, can be achieved within certain limits resultant from the movement of the parallelogram assemblies.

Once the desired vertical and horizontal position is achieved, lateral positioning may be accomplished by turning the crank 99', thereby turning the pinion 93 with respect to the gear rack 73 and causing the basket as sembly $1 to be moved laterally with respect to the balance of the mechanism. For example, the basket assembly 81 may be moved to either of the alternate positions 110 or 111 illustrated in FIGURE 2.

As will be understood by the foregoing description, the universally movable work platform of the present invention may be utilized to gain access to otherwise inaccessible regions and to provide convenient working facilities for workmen in carrying out each of applicants aforesaid objectives.

While there is herein shown and described what is conceived to be the most practical and preferred embodiment of this invention, it is recognized that departures may be made therefrom Within the scope of the invention without limiting the details disclosed herein, the invention being limited only in accordance with the spirit and scope of the appended claims.

I claim:

1. A work platform comprising:

(a) a base; i

(b) a basket assembly- (c) mechanical means connected to said base and said basket assembly vertically and horizontally relative to said base and including,

a pair of parallelogram linkages, a stabilizer assembly pivotally connected to mutually adjacent ends of said linkages, separate actuator means for independently moving each of said parallelogram linkage, a first one of said linkages pivotally connected to said base and said stabilizer assembly, and a second one of said linkages pivotally connected to said stabilizer and said basket assembly; (d) a pair of vertically spaced tracks upon upper and lower portions of said second parallelogram linkage adjacent said basket assembly;

(e) first roller means aifixed to said basket assembly and positioned to bear against and roll over said upper track so as to facilitate lateral basket movement and prevent separation of said basket from .said second parallelogram linkage;

(7) second roller means/affixed .to said basket as sembly and positioned to bear against and rollover said lower track so as to facilitate lateral basket movement and support said basket in its vertical position with respect to said parallelogram linkage; and

(g) drive means upon said basket assembly and said second parallelogram linkage for moving said basket assembly laterally with respect to said last mentioned linkage.

2. The work platform of claim 1, wherein said lower track includes vertical and horizontal portions and said second roller means comprises a roller bearing against said vertical track portion to restrain movement of said basket toward said second parallelogram linkage, and a roller bearing against said horizontal track portion to maintain the vertical position of said basket relative to said second parallelogram linkage.

3. The work platform of claim 1, wherein said drive means comprises:

(a) a gear rack alfixed to said second parallelogram linkage and spaced 'adjacently outward from said lower track;

(b) a pinion gear engaging said gear track and rotatably ailixed upon said basket for movement therewith; and

(c) crank means connected to said basket for rotating said pinion and causing said basket to be moved laterally.

4. The work platform of claim 1, wherein limit switch means are provided to prevent said parallelogram linkages from being depressed beyond predetermined locaions "and wherein detector means is provided to stop parallelogram movement in the event that structural in terference should occur during operation.

References Cited by the Examiner UNITED STATES PATENTS 803,717 11/05 Schwarz et a1. 182-63 2,500,815 3/50 Gerli 1s2 2 2,674,500 4/54 Hukari 182-2 3,031,021 4/62 Mitchell 1s2 -22s HARRISON R. MOSELEY, Primary Examiner.

Claims (1)

1. A WORK PLATFORM COMPRISING: (A) A BASE: (B) A BASKET ASSEMBLY; C) MECHANICAL MEANS CONNECTED TO SAID BASE AND SAID BASKET ASSEMBLY VERTICALLY AND HORIZONTALLY RELATIVE TO SAID BASE AND INCLUDING, A PAIR OF PARALLELOGRAM LINKAGES, A STABILIZER ASSEMBLY PIVOTALLY CONNECTED TO MUTUALLY ADJACENT ENDS OF SAID LINKAGES, SEPARATE ACTUATOR MEANS FOR INDEPENDENTLY MOVING EACH OF SAID PARALLELOGRAM LINKAGE, A FIRST ONE OF SAID LINKAGES PIVOTALLY CONNECTED TO SAID BASE AND SAID STABILIZER ASSEMBLY, AND A SECOND ONE OF SAID LINKAGE PIVOTALLY CONNECTED TO SAID STABILIZER AND SAID BASKET ASSEMBLY; (D) A PAIR OF VERTICALLY SPACED TRACKS UPON UPPER END LOWER PORTIONS OF SAID SECOND PARALLELOGRAM LINKAGE ADJACENT SAID BASKET ASSEMBLY; (E) FIRST ROLLER MEANS AFFIXED TO SAID BASKET ASSEMBLY AND POSITIONED TO BEAR AGAINST AND ROLL OVER SAID UPPER TRACK SO AS TO FACILITATE LATERAL BASKET MOVEMENT AND PREVENT SEPARATION OF SAID BASKET FROM SAID SECOND PARALLELOGRAM LINKAGE; (F) SECOND ROLLER MEANS AFFIXED TO SAID BASKET ASSEMBLY AND POSITIONED TO BEAR AGAINST AND ROLL OVER SAID LOWER TRACK SO AS TO FACILITATE LATERAL BASKET MOVEMENT AND SUPPORT SAID BASKET IN ITS VERTICAL POSITION WITH RESPECT TO SAID PARALLELOGRAM LINKAGE; AND (G) DRIVE MEANS UPON SAID BASKET ASSEMBLY AND SAID SECOND PARALLELOGRAM LINKAGE FOR MOVING SAID BASKET ASSEMBLY LATERALLY WITH RESPECT TO SAID LAST MENTIONED LINKAGE.

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