US3834488A

US3834488A - Aerial platform with articulating jib

Info

Publication number: US3834488A
Application number: US00303760A
Authority: US
Inventors: J Grove
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-11-06
Filing date: 1972-11-06
Publication date: 1974-09-10
Anticipated expiration: 1991-09-10
Also published as: BE814260A; DE2355370C2; DE2355370A1; CA988043A

Abstract

An aerial platform is carried by an extensible boom which is mounted on a motor vehicle for swinging movement in horizontal and vertical planes: a connector is pivoted to the end of the boom, a jib is pivoted at one end to the connector for vertical swinging movement and the aerial platform is pivotally connected to the other end of the jib. The jib has upper and lower arms, which remain parallel. The platform is a basket and the arms are connected to the lower portion of the basket. Power devices cause pivoting of the connector relative to the boom, and the boom relative to the vehicle, and comprise hydraulic cylinders connected in master-slave relationship.

Description

United States Patent [191- [111 3,834,488 Grove Sept. 10, 1974 [5 AERIAL PLATFORM WITH ARTICULATING JIB Primary Examiner-ReinaldoP. Machado [76] Inventor: John L. Grove, PO. Box 695, Mame Agent McConnellsburg, Pa. 17233 [22] Filed: Nov. 6, 1972 [21] Appl. No.: 303,760

[52] US. Cl. 182/2 [51] Int. Cl 1366f 11/04 [58] Field of Search 182/2, 141, 148; 212/17, 212/144 [56] References Cited 7 UNITED STATES PATENTS 2,674,500 4/1954 Hukari 182/2 2,724,620 11/1955 Johnson 182/2 3,043,395 7/1962 Volkel 182/2 3,470,980 10/1969 Irwin 182/2 3,708,037 1/1973 Tranchero 182/2 ABSTRACT An aerial platform is carried by an extensible boom which is mounted on a motor vehicle for swinging movement in horizontal and vertical planes: a connector is pivoted to the end of the boom, a jib is pivoted at one end to the connector for vertical swinging movement and the aerial platform is pivotally connected to the other end of the jib. The jib has upper and lower arms, which remain parallel. The platform is a basket and the arms are connected to the lower portion of the basket. Power devices cause pivoting of the connector relative to the boom, and the boom relative to the vehicle, and comprise hydraulic cylinders connected in master-slave relationship.

14 Claims, 3 Drawing Figures PATENTED I 0 1974 SHEHZGFZ AERIAL PLATFORM WITH ARTICULATING JIB BACKGROUND OF THE INVENTION The present invention relates to aerial platforms for supporting workmen at positions remote from a supporting vehicle.

Aerial platforms are in wide-spread use for supporting a workman in a position which is remote from a supporting surface such as a road-way, so that the workman can perform his tasks while supported at substantial heights above the ground, or in positions laterally spaced from a supporting location, such as a roadway. Typically, aerial platforms comprise a motor vehicle having an extensible boom mounted on the vehicle for swinging movement in horizontal and vertical planes, the boom carrying a workmans platform, in the form of a basket, at its outer end. A basket comprised a floor and upstanding walls to prevent the accidental falling of the workman from the basket. The platform or basket was pivotally connected to the boom, usually at the free end thereof, and provision was made for maintaining the floor of the basket horizontal during vertical swinging movement of the boom. Typically, hydraulic cylinders were used for the swinging movements of the boomand for extending the boom, although the prior art recognized that other mechanical devices could be provided for causing such movements.

Control of the movements of the platform were provided both in the platform, and at ground level.

The constructions of aerial platforms provided heretofore have permitted the workmen to achieve a position remote from the supporting vehicle, typically a position substantially above the level of the vehicle and laterally, or to the side, of the vehicle. Thus, work could be performed in trees, on wires, on elevated structures such as the sides of buildings or of large airplanes and the like, even where the supporting vehicle could not be placed under or directly adjacent the work location.

In order to provide greater flexibility, a number of proposals have been made for alternate constructions of the above described basic aerial platform construction. In one construction, a pivoted extensible boom had an arm pivoted at one end to the free end of the boom and the arm carried at its other end a pivotally supported platform; the pivoted arm was actuated by a piston and cylinder arrangement for vertical swinging movement, the construction limiting the movement of the arm from a position forming an acute angle with the boom axis to a position substantially in line with the boom axis.

Another disclosure heretofore known provides an extensible mast which had no vertical pivoting motion, which carried at its free end a pivotal arm or jib which could move to either side of the substantially vertical boom or mast, the pivoting arm or jib supporting a platform at its outer end. This construction was limited in that the supporting vehicle could not be further from the work position than the length of the pivoted arm plus a small distance gained by the slight tilt of the boom or mast from the vertical.

Another known construction included a telescopic and articulated boom assembly having a swingable arm member pivotally connected on one boom section, and at its outer end, the pivoted arm pivotally supported a workmans basket which hung suspended beneath the pivotal connection between the basket and the arm. This construction was limited in that the pivoted arm could not move below the axis of the boom, but was required to be above or in line with the boom in all positions thereof.

A further known construction of interest provided an extensible boom which was swingable in vertical and horizontal planes, and included a rotatable elbow connected to a boom section intermediate the ends of the boom for rotation through 360, this rotatable elbow carrying a platform at its outer end, being pivotally connected to the platform at the top thereof. While in this construction the elbow could move to positions both above and below the boom axis, this construction was limited in that it would not permit the workman to be positioned in a downwardly facing opening, such as a bottom bay of a large aircraft, while the vehicle was at a relatively great distance from the aircraft.

SUMMARY OF THE INVENTION The aerial platform of the present invention includes a vehicle having an extensible boom mounted on it for swinging movement in vertical and horizontal planes. At its free end, the boom has a connector which is pivoted to it for swinging movement in a vertical plane, being operated by a hydraulic cylinder which is a slave cylinder to a master hydraulic cylinder which causes vertical swinging movement of the boom. Consequently, the connector moves in a vertical are equally and oppositely to the vertical swinging of the boom. An articulated jib is provided, being pivotally connected at one end of the connector, outwardly of the boom, and being pivotally connected at its other end to the lower portion of a workmans basket. The articulated jib is in the form of upper and lower parallel arms, which are swung by an independently controlled hydraulic cylinder approximately above and below the boom axis.

Among the objects of the present invention are to provide an aerial platform of sturdy construction and improved flexibility. A further object of the present invention is the provision of an aerial platform which has an articulated jib capable of movement both above and below the boom axis. Yet another object of the present invention is to provide an aerial platform which is capable of positioning a workman both within a downwardly facing bay opening provided in a large airplane, while the vehicle is laterally remote from the opening, and another. object is to provide such a vehicle which will enable a workman to be positioned above a point on an aircraft wing located substantially above ground level, and which point is substantially spaced from the leading and trailing edges of the aircraft wing.

Other objects and many of the advantages of the present invention will be readily understood from the following specification and drawings.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is an elevational view of an aerial platform in accordance with the present invention, and showing the parts in alternate positions thereof.

FIG. 2 is an elevational view, with parts removed, of l the boom and associated elements of the aerial platform of FIG. 1, to an enlarged scale, and partially schematic.

FIG. 3 isa plan view of the structure of FIG. 2, with parts removed.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, wherein like or corresponding reference numerals are used for like or corresponding parts throughout the several views, there is shown in FIG. 1 an aerial platform apparatus generally designated and including a wheeled vehicle 12 of conventional engine-powered and steerable construction. The vehicle 12 includes outriggers 14, one of which is shown in FIG. 1, and a base 16 for supporting the boom support 18. The boom support 18 is journalled to the base 16 so that it may rotate through a full circle about a vertical axis, in conventional manner. At its upper end, the boom support 18 pivotally supports an extensible boom 20, so that boom 20 may be swung in a vertical plane by boom luffing cylinder 19. At its outer end, boom 20 has pivotally secured to it a connector 30, and an articulated jib 40 is pivotally con nected to the connector at its inner end, and carries a workmans basket 60 at its outer end. As may be seen from the dotted line showings in FIG. 1, the articulated jib may move to positions above and below the axis of boom 20, and specifically in the embodiment shown, the jib 40 may move to positions substantially 63 above and below the axis of boom 20. The attitude of the platform 60 is unchanged during movement of both the boom 20 and the articulated jib 40, so that the floor of the platform or basket 60 always remains substantially horizontal.

It will be noted that when the extensible boom 20 is luffed or swung in a vertical plane from the horizontal position to the inclined position, the connector 30 will rotate in a vertical plane, simultaneously, equally and oppositely, so that as the boom 20 is luffed upwardly, the orientation of the articulated jib and the attitude of the basket or platform 60 will remain unchanged.

Referring now to FIG. 2, the boom support 18 is shown, having a bearing 22 at its upper end in which is journalled a shaft which supports the boom 20 in known manner. Boom 20 is provided with an ear 23 to which is anchored the piston rod of the cylinder 21, the

cylinder 21 being connected to the boom support by a pivotal connection provided at 24.

The boom 20 is an extensible boom of known configuration, having three telescopic sections, 20A, 20B and 20C, telescoping movement of which may be effected by a suitable power means. The power means (not shown) for extending and retracting the boom 20, as well as all of the other power means for swinging the boom 20 and the articulated jib 40 are controlled by control switches, control valves or the like, with control elements placed both in the platform or basket 60 and on the vehicle 12.

The outer or free end of the boom 20, and more particularly of the boom fly section 20C, is provided by a pair of spaced

plates

26A and 26B (see also FIG. 3) fixed to either side of the end portion of the fly section 20C and thence extending rearwardly and above the boom, as shown in FIGS. 1 and 2. A hydraulic cylinder 27 lies between the rearward extension of the

plates

26A and 26B, cylinder 27 being pivotally connected at its rear end to the plates 26A and 2613 by a pivot pin 28.

A connector 30 is pivotally connected to the free or outer end of the boom 20, connector 30 comprising a pair of plates 31A and 3113 which are in spaced parallel the connector 30 to boom 20, specifically passing through the

plates

26A and 26B and the connector plates 31A and 318. The piston rod of cylinder 27 (see also FIG. 3) is pivotally connected by a pin 34 to the connector 30.

The boom 20 is raised by supplying pressure from a pump (not shown) to the lower end of boom luffing cylinder 19. As boom 20 is raised in a vertical plane, pivoting counter-clockwise about pivot 22, the ear 23 is also pivoted, and forces the piston rod of the master cylinder 21 downwardly, expelling liquid from the lower end of the cylinder 21. This liquid passes by hydraulic line L-l to the rear or left end of the hydraulic cylinder 27, thereby causing the piston of hydraulic cylinder 27 to move to the right, so as to rotate the connector 30 about the pivot pin 33 in a clockwise direction.

Cylinders

21 and 27 are of equal bore diameter, rod diameter and stroke. The construction is such that the connector 30 is caused to swing in a vertical plane substantially simultaneously with the vertical swinging or luffing of the boom 20, connector 30 moving equally and oppositely to the swinging movement of the boom 20. This master-slave connection of the

cylinders

21 and 27 serves to maintain the articulated jib 40 in its original attitude during luffing movement of the boom 20. When boom 20 is lowered through movement in a vertical plane, the piston of hydraulic cylinder 21 will travel upwardly and hydraulic liquid will flow through the hydraulic line L-2 from the upper end of cylinder 21 to the right hand or outer end of cylinder 27 through said hydraulic line L-2, thereby causing counterclockwise rotation or swinging movement in a vertical plane of the connector 30. This movement, also, will be simultaneously, equally and opposite to the movement of the boom 20.

The articulated jib 40 comprises an upper arm 31 which is located between the

plates

31A and 31B, upper arm 41 being of hollow rectangular cross section and having at its left or rear end a pair of ears 42A and 428 which also extend within the

plates

31A and 31B and which are pivotally connected by a pivot pin 43, as is clearly shown in FIG. 3. At its outer or forward end, the upper arm 41 has a pair of ears 44A and 448 through which passes a pivot pin 45.

A pair of

lower arms

46 and 47 cooperate with the upper arm 41 to form the jib 40, the

lower arms

46 and 47 being preferably of tubular construction, and being connected at their left or rear ends by a horizontally extending pivot pin 48 to the connector 30. The

arms

46 and 47 lie outwardly of the

plates

31A and 31B forming the connector 30, and at their forward ends, the

lower arms

46 and 47 are journalled to a lower pivot pin 49.

As will be seen from FIG. 2, the pivot pins 43 and 48 lie in substantially vertical alignment in the position of the parts as shown, as do the pivot pins 45 and 49. The latter two pivot pins connect the jib 40 to a U-shaped basket support 50 which is rearwardly facing, and of substantial vertical extent. Thus, the articulated jib 40, together with the connector 30 and support 50 form a parallelogram. The jib 40 may be articulated, or swung in a vertical plane relative to the connector 30 by means of the hydraulic cylinder 51having its one pivotally connected to the connector 30 by the pivot pin 48, and having the piston rod thereof pivotally connected by a pivot pin 52 which extends between

ears

53A and 53B which are secured to and depend from the upper arm 41. Extension and retraction of the jib actuating cylinder 51 will cause the jib 40 to move from the position shown in FIG. 2 to a position in which the

arms

41, 46 and 47 are substantially 63 above or below, as required, the axis of the boom 20.

The basket 60 is of generally known construction, comprising a floor 61 which is preferably of expanded metal or the like, and which is bounded by a lower rail 62. Vertical rails 63 extend upwardly from lower rail 62, and are connected with a mid-rail 64 and an upper rail 65, the basket 60 being of generally rectangular plan form.

Ears

66A and 66B are secured to portions of the basket or platform 60 and to the support 50, so as to secure the basket 60 to support 50. Conventional welding techniques are utilized to assemble the basket 60, and to secure it to the support 50.

In operation, the aerial platform apparatus may be moved to the location of the work, which in the present instance, for illustrative purposes, is taken to be maintenance of a large aircraft having a downwardly facing bay opening in the belly thereof, located many feet above the ground. The vehicle 12 cannot be placed directly under the aircraft bay, and so is placed laterally of the vertical projection thereof. The workman mounts the platform or basket 60, and through controls therein (not shown) actuates the cylinder 21 to raise the boom in a vertical plane. Due to the masterslave connection of the cylinder 27, the connector will be rotated about the pivot pin 33 in a clock-wise direction (as viewed in FIGS. 1 and 2), the rotation of connector 30 being substantially simultaneously with and equally and opposite to the swinging movement of boom 20, so as to maintain the attitude of the platform or basket 60 constant: that is, the floor 61 remains substantially horizontal while the boom 20 is being raised. The boom 20 may also be swung in a horizontal plane, in conventional manner. Further, the boom 20 is extended, so that the basket 60 is in position beneath the bay opening. The cylinder 51 may then be actuated to raise the jib 40 above the axis of boom 20, and as necessary the boom 20 may also be extended. This action will move the inner end of the jib 40 outwardly, and closer to the aircraft bay, permitting the workman in the basket 60 to move upwardly into the aircraft bay, this movement being facilitated by the connection of the jib 40 to the lower portion of the support 50 and basket 60. Adjustment in normal manner of the several hydraulic cylinders will continue until the exact position desired by the workman within the elevated downwardly opening aircraft bay is achieved.

Thereafter, by appropriate manipulation of the controls to thereby effect movement of the several hydraulic cylinders, the workman may remove the platform or basket 60 from the aircraft bay, and the aerial platform apparatus 10 may then be moved to a different position relative to the aircraft, to permit the workman to have access to the upper surface of the aircraft wing which is between the leading and trailing edges of the aircraft wing. As is known, it is often necessary for workmen to be positioned on the wing, so that they may have access to fuel openings or other maintenance points provided adjacent a spar which will support the weight of the workmen. The weight-supporting spar is spaced rearwardly of the wing leading edge and forwardly of the wing trailing edge, and the present apparatus 10 will permit the basket to be placed in position above the spar, and then the jib 40 may be moved downwardly of the axis of the boom 20, so that the connector 30 is substantially above the aircraft wing while the floor 61 of the basket 60 lies closely above the wing upper surface. In reaching the wing upper surface, the vehicle 12 may be placed either beneath the aircraft wing, or forwardly or rearwardly of it, so that there is a minimum of restriction of the positioning of the vehicle 12 relative to the point on the aircraft wing which is desired to reach.

There has been provided an aerial platform apparatus of strudy construction and great flexibility, the apparatus including an extensible boom having a connector pivoted to it, with an articulated jib connected to the connector and to the workmans basket by horizontal pivots. The platform is moved by a cylinder connected to the main boom working cylinder in masterslave relationship for simultaneous, equal and opposite swinging movement to the boom, so that the platform remains level or of constant attitude during boom luffing. Further, there has been provided a platform apparatus providing access to difficult-to-reach places, such as the downwardly facing bay of a large aircraft, where positioning of the vehicle of the apparatus relative to the bay is restricted to a position substantially laterally of the bay. Further, the articulated jib of the herein disclosed aerial platform apparatus may move substantially 60, actually 63 in the preferred embodiment, above and below the boom axis, and the articulated jib itself is of sturdy construction and is connected to the lower portion of the workman s basket, thereby providing greater access to remote working locations.

It will be obvious to those skilled in the art that various changes may be made without departing from the spirit of the invention and therefore the invention is not limited to what is shown in the drawings and described in the specification but only as indicated in the appended claims.

I claim:

1. Aerial platform apparatus comprising:

a. a vehicle,

b. a linearly extensible boom,

0. means mounting said boom on said vehicle for swinging movement in vertical and horizontal planes,

d. a connector pivoted to the boom free end for swinging movement thereabout in a vertical plane,

e. means for vertically swinging said boom,

f. means for vertically swinging said connector substantially equally and oppositely to the vertical swinging of said boom,

g. load support means, and

h. vertically swinging jib means extending between and pivotally connected to said load support means and said connector and comprising actuating means for raising and lowering said load support means relative to the axis of said boom while maintaining constant the attitude of said load support means.

2. The aerial platform apparatus of claim 1, said low support means comprising a personnel support platform having a floor, said last mentioned means maintaining said floor substantially horizontal during vertical swinging movement of said platform.

3. The aerial platform apparatus of claim 1, wherein said boom and connector swinging means comprises a pair of hydraulic cylinders.

4. The aerial platform apparatus of claim 3, wherein one said cylinder swings said boom and a second said cylinder swings said connector, and conduit means connecting said cylinders in master-slave relationship.

5. The aerial platform apparatus of claim 1, said last mentioned means comprising upper arm means and lower arm means, said arm means being substantially parallel.

6. The aerial platform apparatus of claim 5, said lower arm means comprising a pair of laterally spaced arms.

7. The aerial platform apparatus of claim 6, said upper arm means comprising an arm in a vertical plane between said pair of lower arms.

8. The aerial platform apparatus of claim 7, and by draulic cylinder means for swinging said arm means.

9. Aerial platform apparatus comprising:

a. a vehicle,

b. a linearly extensible boom,

c. means mounting said boom on said vehicle for horizontal swinging movement,

d. means mounting said boom on said vehicle for ver tical swinging movement,

e. a connector pivotally connected to said boom for vertical swinging movement about an axis through said boom, f. means for rotating said connector, g. platform means spaced from said connector, and

h. means connected to said platfrom means and to said connector for swinging said platform means to and from positions above and below the axis of said boom and for maintaining constant the attitude of said platform means.

10. The aerial platform apparatus of claim 9, wherein said last mentioned means comprises upper and lower parallel arms pivotally connected to said connector and to said platform means.

11. The aerial platform apparatus of claim 10, wherein said platform means comprises a floor and wall means extending upwardly therefrom, and wherein said arm means are pivotally connected to said basket at the lower part thereof.

12. The aerial platform apparatus of claim 10, wherein said last mentioned means comprises hydraulic cylinder means for swinging said arm means.

13. The aerial platform apparatus of claim 9, wherein said last mentioned means comprises arm means having a range of movement of approximately above and below said boom axis.

14. The aerial platform apparatus of claim 9, wherein said connector is pivotally connected to the free end of said extensible boom.

Claims

1. Aerial platform apparatus comprising: a. a vehicle, b. a linearly extensible boom, c. means mounting said boom on said vehicle for swinging movement in vertical and horizontal planes, d. a connector pivoted to the boom free end for swinging movement thereabout in a vertical plane, e. means for vertically swinging said boom, f. means for vertically swinging said connector substantially equally and oppositely to the vertical swinging of said boom, g. load support means, and h. vertically swinging jib means extending between and pivotally connected to said load support means and said connector and comprising actuating means for raising and lowering said load support means relative to the axis of said boom while maintaining constant the attitude of said load support means.

8. The aerial platform apparatus of claim 7, and hydraulic cylinder means for swinging said arm means.

9. Aerial platform apparatus comprising: a. a vehicle, b. a linearly extensible boom, c. means mounting said boom on said vehicle for horizontal swinging movement, d. means mounting said boom on said vehicle for vertical swinging movement, e. a connector pivotally connected to said boom for vertical swinging movement about an axis through said boom, f. means for rotating said connector, g. platform means spaced from said connector, and h. means connected to said platfrom means and to said connector for swinging said platform means to and from positions above and below the axis of said boom and for maintaining constant the attitude of said platform means.

13. The aerial platform apparatus of claim 9, wherein said last mentioned means comprises arm means having a range of movement of approximately 60* above and below said boom axis.