Scaffold Drive And Steering Unit

Abstract

A scaffold unit for construction and maintenance activities which provides a reversible drive motor at a fixed support wheel for propelling the scaffold and a motorized steering apparatus for the directional control of said scaffold by steering at least one castor mounted support wheel. The drive and steering motors are connected to a control panel that is movable to various elevated and/or remote locations. Electric drills may be used for said motors.

Description

BACKGROUND OF THE INVENTION

In connection with construction of maintenance operations, it is often advantageous for a workman to have a scaffold support so that he can work at high elevations with safety. Where ceilings or utilities are being installed or where lighting and heating systems are to be maintained, a rolling type scaffold is often used that may be conveniently moved to various work locations. Manipulation of the usual castor wheel supported scaffold generally requires an additional workman who can push and guide the scaffold and the workmen supported thereby to successive work stations. In order to avoid this obvious misuse of labor, others have previously devised scaffold propelling and steering systems that may be operated by a workman at his elevated work station. In general, the previous systems have been quite expensive. It is believed that the overall expense and the inconvenience of using and storing prior types of steering and drive apparatus have been detrimental to the widespread use of such systems. The present invention is intended to overcome shortcomings of the previous systems.

SUMMARY OF THE INVENTION

Briefly stated, the present invention provides attachments that may be applied to wheel supported scaffold units to propell the units and to steer the entire scaffold so that a single workman can move the scaffold and himself to successive work stations. A first drive unit provides a drive reduction system and a mounting for a drive motor. The motor and drive reduction are connected to one support wheel of the scaffold. A steering unit is similarly affixed to the scaffold in position adjacent a castor type wheel to steer the wheel. A crank arm is powered by a steering motor, and the crank arm is connected by a steering rod to a steering arm associated with the pivoted wheel. Either or both motor devices may use a conventional electric drill which may itself provide a substantial gear reduction. Both motor devices are connected to a remote steering control unit that may be positioned adjacent the work platform. Steering and drive control is obtained by manipulation of control elements.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing a preferred embodiment of the invention,

FIG. 2 is a plan view taken along the line 2--2 of FIG. 1 and illustrating the steering control unit,

FIG. 3 shows an electric drill for use as a motor drive,

FIG. 4 is a top view taken along the line 4--4 of FIG. 1,

FIG. 5 is a side elevation of the drive mechanism as shown in FIG. 4, and

FIG. 6 is an illustration of the remote control apparatus.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In FIG. 1 a preferred embodiment of the invention is shown. Here a scaffold unit 11 is shown to be of somewhat conventional construction with the end frames 12 and 13 being joined together by cross braces 14. The cross braces are engaged in lock receptacles 16 on the upright standards 17. While a single height scaffold is shown for convenience of illustration, it should be recognized that the upper ends 18 of the upright standards 17 are adapted to receive a pin of additional scaffold components so that the total height of the scaffold system may be increased to as much as 3 or 4 units.

At the lower ends of the scaffold standards 17, support wheels are provided. The wheel 19 may be fixed with respect to its associated standard 17, or it may be a freely pivoting castor wheel. Support wheels 21 are castor wheels that are free to turn with respect to their standards 17. A separate "front" wheel 22 is likewise of a castor type. Provision is made for guiding and steering this wheel 22. Remaining wheel 23 is a drive disposed in fixed position with respect to its associated standard 17.

A platform 24 is welded or formed integrally with the forked support 26 for drive wheel 23. The platform provides support for an electrically powered drive motor 27. As best shown in FIGS. 4 and 5 the output power from drive motor 27 is connected by a drive belt 28 to a jack shaft 29 that is itself rotatably mounted on platform 24. A further input gear or sprocket 31 is also mounted on jack shaft 29 to turn therewith and to deliver power by means of the drive chain 32 to a driven sprocket 33 mounted on the axle 34 of drive wheel 23. Rotation and power provided by the drive motor 27 then serves to rotate the drive wheel 23. Since the direction of rotation for the drive motor 27 is reversible, the end frame 12 may then be moved forwardly and rearwardly to propell such end frame and the entire scaffold unit 11. Since a relatively slow moving speed will be satisfactory, the drive reduction provided by the pulley sprocket system illustrated will, together with any gear reduction in the motor unit itself, give close control over the scaffold drive speed. For either maintenance or construction operation uses, it has been found that the motor of an electric drill can be used beneficially for this purpose since reversible and multispeed drills are available at a reasonable cost. Such electric drills may be provided with a drive pulley 36 to serve this auxiliary purpose. For the particular type of electric drill illustrated the handle has been removed, and the handle mounting is directly applied to a support frame 37. For other uses the support frame could include elements for grasping the drill handle to provide an adequate mount. Similarly, a spindle for drive pulley 36 can be engaged in the chuck of an electric drill so that the drill can be used without modification. This alternate configuration is shown in FIG. 3 where the drill chuck 38 receives and holds the spindle 39 of a drive pulley 36. Where this alternate system is used the drill can be used for conventional drilling operations when it is not in use as a scaffold drive component. A heavy duty three-eighths inch drill or a one-half inch drill can be successfully used in either of the described installations.

With the fork supports of two or three of the scaffold support wheels being free to turn with respect to the upright standards 17, some steering system is required for controlling the direction of travel for the scaffold unit 11. Powered components for a preferred steering system are shown in FIGS. 1 and 2. Here a steering motor 41 is interconnected to a gear box drive 42. The steering motor 41 is reversible and it is used to move a crank arm 43 to alternate positions. Preferably limit stops are provided by the motor or gear box or in association with the crank arm 43 so that the crank arm will move only in an arcuate pattern. A steering rod 44 is connected to the crank arm 43 and the steering rod is itself connected to an arm 46. Arm 45 moves with the support forks for front wheel 22 and causes rotation thereof with respect to its associated standard 17. Since thrust bearings are used between the standards and all of the castor type wheels, a low order of power will cause pivoting of the wheel 22. As the wheel 22 is turned, the entire scaffold will be steered in the direction that the wheel 22 is turned.

Cables 47 and 48 interconnect the drive motor 27 and the steering motor 41, respectively, to a remote control unit 49. The control unit 49 is provided with mounting brackets 51 so that it may be positioned on a cross bar 52 of the scaffold unit at any position convenient to a workman standing on support planks or deck 53. A substantial length of cable is provided so the control unit 49 may be moved to a next higher scaffold and to convenient operative position at a work deck that may be 20 to 30 feet above the supporting floor.

The remote control unit 49 as shown in FIGS. 1 and 6 provides drive and steering controls 54 and 56, respectively. The toggle of the drive control may be moved to forward, neutral and reverse positions, while the toggle of the steering control 56 is moved to left and right positions to correspondingly energize the associated motors. Signal lights are provided with the drive light 57 indicating when the drive motor is energized, and a steering light 58 gives indication of steering unit actuation. A power cable 59 provides power to the remote control unit 49 and through such control unit to the drive and steering components. A rheostat speed control 61 is provided to further control the propulsion speed for the scaffold unit 11.

With this type of scaffold unit a single workman may install plumbing, electrical or heating utilities or suspended ceilings or lighting systems. Similarly the scaffold may be used for the maintenance of such systems as in the replacement of fluorescent lights, etc. A stock of parts may be carried to the upper supporting deck 53 and thereafter a plurality of operations can be accomplished before a workman would have to come down.

The movable control system is especially beneficial for one-man operation, since the control unit can at all times be placed adjacent the work station. Further, the control unit 49 is of light weight, and it may be readily moved to the top platform or to a position near the supporting ground. When the scaffold is moved from one work station to another, the control box may be carried or attached to the scaffold at a low elevation for manipulation by a walking workman.

When the scaffold is to be used at unimproved work sites, the support wheels will usually be of larger diameter or of a pneumatic type so that the scaffold can be moved across and over minor obstructions. Pneumatic wheels are or useful when the scaffold is to be used over unimproved floors or on uncompacted earth surfaces.

The gear or power reduction used in the drive system is usually sufficient to prevent free-wheeling movement of the scaffold. This feature prevents undesired movement unless the drive or steering motors are actuated, and it further prevents unauthorized use of misuse of the scaffold. Actually when the unit is to be left over-night, the drive and steering motors can be conveniently removed to be left in secure storage. The gear reduction or power reduction drive is sufficient to prevent undesirable movement of the scaffold even when the motors are removed. Where an electric drill motor is used, the electric drill may be removed for storage or other useage at times when it is not to be used for scaffold drive and steering operations.

Claims

I claim

1. A drive and steering attachment for scaffolding type supports having upright standards that in scaffolding usage may be mateably engaged one above another when multi stages are to be used and wherein each of said standards are further adapted to receive separate supporting wheel attachments when increased mobility is advantageous comprising a plurality of separable and separate wheel attachments for said support with a wheel attachment for each standard, wheels for each said attachment, frame components for each attachment, wheel axles on said frame components for the rotative support of said wheels, means for separately and selectively engaging each of said wheel attachments with the upright standards of said supports, means facilitating the rotative movement of a plurality of said frame components with respect to the vertically disposed axis of the associated support upright to provide a castor type mounting for said plurality of frame components and wheels, an anchor element on said support for non-moving relationship therewith, motive drive means interconnecting said anchor element and at least one of aid castor wheels to provide a steerable wheel whereby said steerable wheel and its associated frame component may be rotated to forwardly and laterally directed positions with respect to the axis of its associated upright and said support, a mount adjacent the frame component of one wheel attachment, a motor drive unit on said mount, drive reduction means intermediate said motor and the wheel of said attachment, means for reversing the drive rotation of said wheel to power forward and reverse movement operations of said wheel attachment, and power control apparatus interconnected to said motive drive means and said motor drive unit whereby an operator may conveniently steer and drive said support unit.

2. The combination as set forth in claim 1 wherein said motive drive means is interconnected to only one steerable wheel.

3. Structure as set forth in claim 1 wherein said steerable wheel and its associated frame component may be rotated through an arc greater than ninety degrees.

4. Structure as set forth in claim 3 wherein electric power control apparatus is provided.

5. The combination as set forth in claim 1 wherein the drive motors are removable and wherein a high drive ratio is provided for said drive reduction means for resisting unpowered movement of said scaffold.

6. The combination as set forth in claim 4 wherein at least one support wheel for said scaffolding is fixed and said motor drive unit is operatively connected to such fixed support wheel.

7. The combination as set forth in claim 4 wherein a cable interconnects the control apparatus to said power steering means and to said motor drive unit.

8. The combination as set forth in claim 4 and additionally comprising a speed change component for varying the speed of said motor drive unit.

9. The combination as set forth in claim 4 and further comprising reversing means for said motor drive unit.