# US 4,399,906 A · Temperature expansive screw conveyor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,399,906 A - Document ID: US4399906A - Status: Granted - Kind: A - Application number: 06/227,253 - Filed: 1981-01-22 - Granted: 1983-08-23 - Earliest claimed: 1981-01-22 - Assignees: Thomas Conveyor Company - Inventors: Cecil E. Millsap - Web page: https://patentgrep.com/patent/US4399906A ## CPC - B65G 33/265: {with a continuous helical surface (flexible screws B65G33/16)} - B65G: TRANSPORT OR STORAGE DEVICES, e.g. CONVEYORS FOR LOADING OR TIPPING, SHOP CONVEYOR SYSTEMS OR PNEUMATIC TUBE CONVEYORS (packaging B65B; handling thin or filamentary materials, e.g. paper sheets or thread, B65H; cranes B66C; portable mobile or lifting or hauling appliances, e.g. hoists, B66D; devices for lifting or lowering goods for loading or unloading purposes, e.g. fork-lift trucks, B66F9/00; emptying bottles, jars, casks, barrels or similar containers, not otherwise provided for, B67C9/00; delivering or transferring liquids B67D; filling or discharging vessels for liquefied, solidified or compressed gases F17C; pipe-line systems for fluids F17D) ## Abstract A screw conveyor (10) is disclosed for use in environments having a large range of temperature. The screw conveyor (10) includes a hollow shaft (12) having a number of aligned circular holes (18a, 18b) therein, with adjacent sets of holes being at right angles to each other. A stake (16) is slidably inserted in each set of holes (18a, 18b) for securing a helical flight (14a-e) to the shaft (12). Four stakes (16) are welded to the back (26) of each of the helical flights (14) along a helical line corresponding to the helical path defined by the flights (14). The slidable interaction of the stakes (16) with respect to the shaft (12) permits each flight (14) to move relative to the shaft (12) during expansion or contraction of the screw conveyor (10). The back peripheral edge (20) and front peripheral edge (22) of adjacent helical flights (14) are overlapping and movable with respect to each other to further accommodate the expansion and contraction of the screw conveyor (10). ## Claims ### Claim 1 A screw conveyor for conveying material comprising: shaft means mounted for rotation about an axis and having holes formed therein, each of said holes being positioned at a predetermined angle from the next adjacent hole; a plurality of stake means slidably inserted in said holes and extending generally outward from said shaft means; a plurality of adjacent flights having a trailing edge and a leading edge with a continuous helical contour therebetween positioned about a portion of said shaft means for conveying material as said shaft means is rotated, the trailing edge of each of said flights slideably overlapping the leading edge of the adjacent one of said flights, each of said flights secured to selected ones of said stake means so that each of said flights and said selected ones of said stake means can move relative to said shaft means during expansion and contraction of the screw conveyor. ### Claim 2 (depends on 1) The screw conveyor of claim 1 wherein said holes in said shaft means are circular and each of said stake means is circular in cross section to permit rotation of said stake means relative to said holes. ### Claim 3 (depends on 1) The screw conveyor of claim 1 wherein the leading edge of each of said flights nearest the point of entry of the material to be conveyed is secured to said shaft means. ### Claim 4 (depends on 1) The screw conveyor of claim 1 wherein each of said flight means is secured to four stake means, each of said stake means extending at right angles to the next adjacent stake means. ### Claim 5 A screw conveyor for conveying material comprising: an elongate central shaft mounted for rotation about an axis having holes formed therein, each of said holes being positioned at essentially ninety degrees from the next adjacent hole; a plurality of stakes slidably inserted in said holes and extending outwardly from said shaft; a plurality of adjacent flights having a trailing edge and a leading edge with a continuous helical contour therebetween positioned about a portion of said central shaft for conveying material as said central shaft is rotated, the trailing edge of each of said flights slideably overlapping the leading edge of the adjacent one of said flights, each of said flights secured to selected ones of said stakes with one of said stakes disposed proximate the surface of the leading edge of an associated one of said flights to support both the leading edge of the associated one of said flights and the overlapping edge of the adjacent one of said flights, the overlapping of said flights accomodating the relative movement between each of said flights, and said central shaft during expansion and contraction of said screw conveyor. ### Claim 6 (depends on 5) The screw conveyor of claim 5 wherein each of said holes in said central shaft is circular and each of said stakes is circular in cross section to permit rotation of said stakes relative to said holes, the cross section of said stake means smaller than said holes for rotation therein. ### Claim 7 (depends on 5) The screw conveyor of claim 5 wherein said flights and said stakes are formed from a weldable material and said selected ones of said stakes are secured to said flight by welding. ### Claim 8 (depends on 5) The screw conveyor of claim 5 wherein said selected ones of said stakes includes four stakes positioned at right angles to each other along a path substantially equivalent to the path defined by each of said flights, one of the four stakes associated with a particular one of said flights attached to the peripheral edge of said flight nearest the point of entry of the material to be conveyed. ### Claim 9 A screw conveyor for conveying material comprising: an elongate central shaft mounted for rotation about its elongate axis and having a plurality of holes formed therethrough generally perpendicular to the axes of rotation, each of said holes being positioned along said central shaft at right angles to the next adjacent hole; a plurality of stakes slidably inserted in said holes and extending outwardly from said central shaft perpendicular to the axis of rotation; a plurality of adjacent helical flights having a leading edge and a trailing edge with a continuous helical contour therebetween for conveying material along said central shaft as said central shaft is rotated, each of said flights being positioned about a portion of said central shaft and dimensioned to circumvent said central shaft more than one revolution thereof, each of said flights secured to selected ones of said stakes with one of said stakes disposed proximate the surface of the leading edge of an associated one of said flights to support both the leading edge of the associated one of said flights and the overlapping edge of the adjacent one of said flights, adjacent ones of said flights slidable overlapping so that the expansion and contraction of the screw conveyor is accommodated by the relative motion of each of said flights and said selected ones of said stakes relative to said central shaft, each of said flights substantially retaining said stakes in said holes and said stakes substantially retaining rotational motion of each of said flights about said shaft. ### Claim 10 (depends on 9) The screw conveyor of claim 9 wherein said holes in said central shaft are circular and said stakes are circular in cross section and smaller than said holes to permit location of said stakes relative to said holes. ### Claim 11 (depends on 9) The screw conveyor of claim 9 wherein said selected ones of said stakes securing associated ones of said helical flights are positioned on the back side of said flights to prevent interference with the material being moved. ### Claim 12 (depends on 9) The screw conveyor of claim 9 wherein said helical flights and said stakes are formed from weldable materials and said selected ones of said stakes securing said helical flight are welded thereto. ### Claim 13 (depends on 9) The screw conveyor of claim 9 wherein said selected ones of said stakes include four stakes positioned at right angles relative to the next adjacent stake and one of said selected stakes secured to the peripheral edge of the associated one of said flights nearest the point of entry of the material to be conveyed. ### Claim 14 A screw conveyor for conveying material comprising: shaft means mounted for rotation about an axis and having holes formed therein, each of said holes being positioned at a predetermined angle from the next adjacent hole; a plurality of stake means slideably inserted in said holes and extending generally outward from said shaft means; a plurality of flights having a helical contour positioned about a portion of said shaft means for conveying material as said shaft means is rotated, the trailing edge of each of said flights slidably overlapping the leading edge of the adjacent one of said flights, each of said flights secured to selected ones of said stake means with one of said stake means disposed proximate the surface of the leading edge of an associated one of said flights to support both the leading edge of the associated one of said flights and the overlapping edge of the adjacent one of said flights so that said flights and said selected ones of said stake means can move relative to said shaft means during expansion and contraction of the screw conveyor.