# US 4,393,630 A · Actuation means for the racking platform of a mast > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,393,630 A - Document ID: US4393630A - Status: Granted - Kind: A - Application number: 06/243,049 - Filed: 1981-03-12 - Granted: 1983-07-19 - Earliest claimed: 1981-03-12 - Assignees: Crane Carrier Company - Inventors: Arnold W. Knox, deceased - Web page: https://patentgrep.com/patent/US4393630A ## CPC - E21B 7/023: {the mast being foldable or telescopically retractable} - B66F 11/04: for movable platforms or cabins, e.g. on vehicles, permitting workmen to place themselves in any desired position for carrying out required operations ({Working platforms on fork-lift trucks B66F9/127; } vehicle aspects of service vehicles B60P3/14; platforms for cleaning windows A47L3/02; devices for rescuing persons from buildings A62B1/02; liftable or lowerable platforms for use on ladders E06C7/16; maintenance travellers for bridges E01D19/10; scaffolds on an extensible sub-structure E04G1/22) - E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS - B66F: HOISTING, LIFTING, HAULING OR PUSHING, NOT OTHERWISE PROVIDED FOR, e.g. DEVICES WHICH APPLY A LIFTING OR PUSHING FORCE DIRECTLY TO THE SURFACE OF A LOAD ({invalid lifting devices A61G7/10; } mounting artificial islands on piles or like supports E02B17/00; scaffolding combined with lifting devices E04G1/22; lifting devices for sliding forms E04G11/24; lifting of buildings E04G23/06; shores or struts E04G25/00; lifts or other hoisting devices on ladders E06C7/12; props for mining E21D15/00) ## Abstract In combination with a telescoping well mast structure having a fixed lower structure and a traveling upper structure, a device to time and actuate the extension and retraction of a racking platform pivotally attached to the upper structure. The device comprises at least one pulley secured within the upper derrick structure adjacent the crown and at least one lower pulley secured within the upper structure adjacent the lower end thereof. At least one cable extends from the platform around the upper pulley, the lower pulley and to a wheeled trolley adapted to travel along a portion of the lower structure. When the upper structure is extended the wheeled trolley is propelled along the lower structure by a pushing member on the upper structure until received into a catch housing on the upper portion of the lower structure. Once the wheeled trolley is restrained by the housing continued extension of the upper structure allows for the racking platform to extend by means of gravity. Retraction of the platform is accomplished by reversing the steps outlined above. ## Claims ### Claim 1 In combination with a telescoping mast having a fixed lower structure and a traveling upper structure, actuation means for timed extension and retraction of a platform attached to said upper structure comprising; at least one upper pulley secured within said upper structure above said platform; at least one lower pulley secured within said upper structure below said platform; traveling means cooperable with said upper structure and said lower structure; catch means on said lower structure for receiving and retaining said lower traveling means; and cable means extending from said platform around said upper pulley, said lower pulley and connected to said traveling means, whereby when said upper structure is extended said traveling means is propelled along said lower structure until received by said catch means whereupon said platform is extended. ### Claim 2 (depends on 1) Actuation means as in claim 1 wherein said telescoping mast being a well mast. ### Claim 3 (depends on 2) Actuation means as in claim 2 wherein said well mast being mounted to a vehicle. ### Claim 4 (depends on 1) Actuation means as in claim 1 wherein said traveling means moves along a selected portion of a vertical member of said lower structure. ### Claim 5 (depends on 4) Actuation means as in claim 4 wherein said catch means being attached to a top portion of said vertical member of said lower structure. ### Claim 6 (depends on 4) Actuation means as in claim 4 wherein said catch means being a housing for receiving said traveling means. ### Claim 7 (depends on 1) Acuation means as in claim 1 wherein said upper structure is provided with a pushing member cooperable with said traveling means to propel said traveling means along said lower structure. ### Claim 8 (depends on 1) Actuation means as in claim 1 wherein said traveling means being a wheeled trolley. ### Claim 9 (depends on 8) Actuation means as in claim 8 wherein said wheeled trolley comprising a central frame, a plurality of aligned wheels connected to said central frame and connection means in said frame for connection of said cable means. ### Claim 10 (depends on 1) Actuation means as in claim 1 wherein said traveling means pivots upon encountering said catch means and is restrained therein. ### Claim 11 In a well mast having a fixed lower structure and a telescoping upper structure, the structures having a rectangular cross-section with said upper structure disposed within and slidably engagable with said lower structure, an improved actuation means for timed extension and retraction of a platform pivotally connected to said upper structure comprising: a plurality of parallel pulleys secured parallel with said platform within an upper portion of said upper structure; a plurality of pulleys secured within a lower portion of said upper structure below said platform; traveling means adapted to move along a selected portion of a vertical member of said lower structure; push means on said upper structure to propel said traveling means along said lower structure; catch means attached to an upper portion of said vertical member of said lower structure for receiving and retaining said traveling means; and a plurality of cables extending from said platform around said upper and lower pulleys and pivotally connected to said traveling means, whereby when said upper structure is extended said push means moves said traveling means into contact with said catch means and the continued extension of the upper structure allows the platform to extend by gravity. ### Claim 12 (depends on 11) Actuation means as in claim 11 wherein said well mast being mounted to a vehicle. ### Claim 13 (depends on 11) Actuation means as in claim 11 wherein said traveling means being a wheeled trolley comprising a central frame, a plurality of aligned wheels connected to said frame and connection means on said frame for pivotal connection of said cable means, one of said wheels of said trolley being in contact with said vertical member of said lower structure. ### Claim 14 (depends on 13) Actuation means as in claim 13 wherein said trolley rotates about the central axis of said frame upon encountering said catch means and is retained therein. ### Claim 15 (depends on 11) Actuation means as in claim 11 wherein said push means being a curved brace extending from said upper structure. ### Claim 16 (depends on 11) Actuation means as in claim 11 wherein said catch means being a housing attached to the upper end of said vertical member of said lower structure.