The present invention relates generally to track-riding vehicles (trolleys) and more specifically to methods and apparatus to enable line-drawn trolleys to turn corners using turntables.
In a wide variety of applications, a trolley is used to transport material or to provide a moveable anchor point for other equipment. In some applications, the trolley has powered wheels that react against the track to provide propulsion. Often, to facilitate that reaction, the powered wheels are actually pinions and the track is fitted with a rack.
Alternatively, propulsion may be achieved by providing an anchored draw line (for example, a wire rope stretched between opposing walls) and a trolley hoist, coupled to the trolley and to the draw line, so that the trolley uses the hoist to pull itself along the draw line as a “line-drawn” trolley. Owing to the lower cost of the components, the line-drawn approach often has significant economic advantage over the powered-wheel approach.
Some of that economic advantage is surrendered, however, in applications requiring the trolley to negotiate a corner. Both approaches typically use a section of track mounted on a turntable to turn the corner. Compared to the powered-wheel approach, however, the line-drawn approach conventionally requires additional labor-intensive tasks of unstringing and restringing the draw line.
Opportunities exist, therefore, to extend the economic advantage of the line-drawn trolley by providing an improved method and apparatus for manipulating the draw line when turning corners.
The opportunities described above are addressed, in one embodiment of the present invention, by an apparatus for turning a corner, the apparatus being disposed adjacent to a grounded surface and comprising: a turntable platter, rotatably coupled to the grounded surface, for orienting a line-drawn trolley; a locking mechanism, disposed on the turntable platter, for preventing rotation of the turntable platter with respect to the grounded surface; a first turntable guide, removably coupled to the turntable platter, for guiding a draw line through the line-drawn trolley; a second turntable guide, removably coupled to the turntable platter, for guiding the draw line through the line-drawn trolley; a first stationary diverter, removably coupled to the grounded surface, for diverting the draw line toward the periphery of the turntable platter; and a second stationary diverter, removably coupled to the grounded surface, for diverting the draw line toward the periphery of the turntable platter.
In another embodiment of the present invention a method for turning a corner comprises acts of: providing a turntable platter in a first orientation; drawing a line-drawn trolley onto the turntable platter; installing a first turntable guide; installing a first stationary diverter; unlocking a locking mechanism, rotating the turntable platter to a second orientation; locking the locking mechanism, removing a second turntable guide; removing a second stationary diverter; drawing the line-drawn trolley off of the turntable platter.
These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:
In accordance with one embodiment of the present invention,
In operation, turntable platter 130 rotates to orient a line-drawn trolley 110 with respect to grounded surface 120. When activated, locking mechanism 140 prevents rotation of turntable platter 130 with respect to grounded surface 120; when de-activated, locking mechanism 140 allows rotation of turntable platter 130 with respect to grounded surface 120. First turntable guide 150 and second turntable guide 190 serve to guide a draw line 180 through line-drawn trolley 110, while first stationary diverter 200 and second stationary diverter 230 divert draw line 180 toward the periphery of turntable platter 130.
In accordance with a more detailed embodiment of the present invention,
In accordance with another more detailed embodiment of the present invention,
In another aspect of the present invention, a method for turning a corner comprises acts of providing turntable platter 130 in a first orientation 210, drawing line-drawn trolley 110 onto turntable platter 130, installing first turntable guide 150, installing first stationary diverter 200, unlocking locking mechanism 140, rotating turntable platter 130 to second orientation 240, locking locking mechanism 140, removing second turntable guide 190, removing second stationary diverter 230, and drawing line-drawn trolley 110 off of turntable platter 130.
In a more detailed embodiment of the method for turning a corner, the act of rotating turntable platter 130 to second orientation 240 comprises drawing draw line 180 through line-drawn trolley 110. Referring to
In another more detailed embodiment of the method for turning a corner, the act of installing first turntable guide 150 comprises disposing first turntable guide 150 tangent to diametral line 170 on first side 160 of diametral line 170.
In yet another more detailed embodiment of the method for turning a corner, the act of installing first stationary diverter 200 comprises disposing first stationary diverter 200 tangent to diametral line 170 on the second side 220 of diametral line 170.
As used herein, line-drawn trolley 110 refers to any vehicle capable of riding a track, pulling (drawing) itself along draw line 180, and maintaining itself on the track despite the force of draw line 180 during rotation.
As used herein, grounded surface 120 refers to any surface with respect to which line-drawn trolley 110 is being moved and rotated. Examples of grounded surface 120 include, without limitation: earth ground; a building roof; or a building floor slab.
As used herein, turntable platter 130 refers to any apparatus or article of manufacture capable of supporting a section of track and line-drawn trolley 110 during rotation. Examples of turntable platter 130 include, without limitation: solid plates of any shape or suitable material; fabricated structures comprising intercoupled members such as, for example, a grillwork of coupled slender members; and combinations thereof.
As used herein, locking mechanism 140 refers to any apparatus or article of manufacture capable of selectively allowing and preventing rotation of turntable platter 130 with respect to grounded surface 120. Examples of locking mechanism 140 include, without limitation: pins (for example, dowel pins, cotter pins, clevis pins, etc.) and receptacles therefor; brakes; clamps; clutches; ratchets and pawls; and combinations thereof.
As used herein, first turntable guide 150, second turntable guide 190, first stationary diverter 200, and second stationary diverter 230 refer to any apparatus or article of manufacture capable of changing the direction of draw line 180 and capable of being installed and removed. Examples of first turntable guide 150, second turntable guide 190, first stationary diverter 200, and second stationary diverter 230 include, without limitation: posts of any suitable material or cross-section (for example,
As used herein, diametral line 170 refers to an imaginary line of infinite extent containing a diameter of turntable platter 130 and fixed to turntable platter 130.
As used herein, draw line 180 refers to any apparatus or article of manufacture capable of being drawn through line-drawn trolley 110 and capable of negotiating the required turns. Examples of draw line 180 include, without limitation: wires; filaments; cables; ropes, including wire rope; and combinations thereof.
As used herein, “drawing” draw line 180 refers to exerting sufficient force on draw line 180 to effect some motion of the system (for example, translating line-drawn trolley 110 or rotating turntable platter 130) other than merely passing a slack draw line 180 through line-drawn trolley 110.
While only certain features of the invention have been illustrated and described herein, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.