# US 9,038,272 B1 · Variable force spring tapes and method of manufacture > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,038,272 B1 - Document ID: US9038272B1 - Status: Granted - Kind: B1 - Application number: 13/906,417 - Filed: 2013-05-31 - Granted: 2015-05-26 - Earliest claimed: 2012-06-04 - Assignees: Vulcan Spring & Mfg. Co. - Applicants: Vulcan Spring & Mfg. Co. - Inventors: Alexander Rankin, VI - Web page: https://patentgrep.com/patent/US9038272B1 ## CPC - F03G 1/02: characterised by shape or material of spring, e.g. helical, spiral, coil - B23K 26/0846: {for moving elongated workpieces longitudinally, e.g. wire or strip material} - B23K 26/38: by boring or cutting - B26D 1/015: {for thin material, e.g. for sheets, strips or the like} - F03G 1/00: Spring motors (spring-driven toys A63H; springs in general F16F; precision time mechanisms, e.g. for clocks or watches, G04B) - Y10T 29/49609: Spring making - F03G: SPRING, WEIGHT, INERTIA OR LIKE MOTORS; MECHANICAL-POWER PRODUCING DEVICES OR MECHANISMS, NOT OTHERWISE PROVIDED FOR OR USING ENERGY SOURCES NOT OTHERWISE PROVIDED FOR (arrangements in connection with power supply in vehicles from force of nature B60K16/00; electric propulsion with power supply in vehicles from force of nature B60L8/00) - B23K: SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM - B26D: CUTTING; DETAILS COMMON TO MACHINES FOR PERFORATING, PUNCHING, CUTTING-OUT, STAMPING-OUT OR SEVERING (for growing crops or plants A01D, A01G; for fodder or straw A01F; for bulk butter A01J; for dough A21C; slaughtering A22B; for tobacco, cigars or cigarettes A24; marking-out, perforating or making buttonholes A41H25/00; manufacturing footwear A43D; brushmaking A46D; surgery A61B; disintegrating, mincing or shredding in general B02C; cutting wire, making pins or nails B21F, B21G; of the kind used formetal B23; cutting by abrasive fluid jets B24C5/02; hand-held cutting tools B26B; perforating, cutting-out, stamping-out or punching, or severing by means other than cutting B26F; for wood B27; for stone B28D; working of plastics or substances in a plastic state B29; making boxes, cartons, envelopes or bags, of paper or similarly worked materials, e.g. metal foil, B31B; article or web delivery apparatus incorporating cutting or line-perforating devices B65H35/00; for leather or upholstery B68, C14B; for glass C03B; making matches C06F; for peat C10F; for sugar C13B45/00; for textile materials D06H; civil engineering, building, mining, see Section E; for light guides G02B6/25; cutting processed photographic material G03D15/04) - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A spring tape suitable for use in spring motor applications where reactive torque varies with rotational deflection. An elongate elastic element is advanced lengthwise and is laser cut into longitudinally complementary shapes which are separated and subsequently pre-stressed into rolls which are cut to length for assembly into a spring motor. ## Claims ### Claim 1 A method of making a flat rolled spring element capable of providing a reactive force that varies with extension tangentially from its rolled state, comprising the steps of: providing an indeterminate length of flaccid tape having a pair of parallel edges defining therebetween a constant widthwise dimension of the tape, advancing said tape lengthwise, and while said tape is advancing, cutting said tape lengthwise and partially widthwise between said edges to form an undulating cut and cutting said tape to form a running cut extending in substantially parallel relation to said edges and intersecting said undulating cut such that a complementary pair of separate co-extending tape strips is formed, and thereafter separating one of said tape strips from the other for coiling about a tool to form said flat rolled spring element. ### Claim 2 (depends on 1) A method according to claim 1, wherein said cutting step is performed by directing a laser beam through said tape. ### Claim 3 (depends on 2) A method according to claim 2, wherein said laser beam is displaced widthwise during said cutting step to form said undulating cut. ### Claim 4 (depends on 3) A method according to claim 3, wherein, during said cutting step, said laser beam is directed to cut along at least one of said edges to form said running cut such that said running cut extends in substantially parallel relation to said edge and intersects said undulating cut. ### Claim 5 (depends on 4) A method according to claim 4, wherein said running cut is repeated at periodic intervals during said cutting step. ### Claim 6 (depends on 1) A method according to claim 1, wherein, during said separating step, said tape strips are displaced for movement in diverging paths. ### Claim 7 (depends on 6) A method according to claim 6, wherein one of said diverging paths leads to a coiling tool and the other of said diverging paths leads to a take-up reel. ### Claim 8 (depends on 1) A method according to claim 1, further comprising the steps of coiling said one of said tape strips and thereafter severing the coiled tape strip completely widthwise after said coiling step. ### Claim 9 (depends on 1) A method according to claim 1, wherein forming said running cut is repeated at periodic intervals during said cutting step. ### Claim 10 A method of making a flat rolled spring element, comprising the steps of: providing an indeterminate length of a flaccid metal tape capable of being pre-stressed into a rolled coil and having a pair of parallel edges defining therebetween a constant widthwise dimension of the metal tape; advancing said metal tape lengthwise; during said advancing step, cutting said metal tape lengthwise and partially widthwise between said edges by directing a laser beam through said metal tape to form an undulating cut such that a complementary pair of separate co-extending first and second metal tape strips is formed, wherein, during said cutting step, said laser beam is directed to cut said metal tape to form a running cut extending in substantially parallel relation to said edges and intersecting said undulating cut; and after said cutting step, separating the first metal tape strip from the second metal tape strip, coiling the first metal tape strip about a coiling tool, and thereafter severing the first metal tape strip completely widthwise after said coiling step to form a flat rolled spring element capable of providing a reactive force that varies with extension tangentially from its rolled state. ### Claim 11 (depends on 10) A method according to claim 10, wherein forming said running cut is repeated at periodic intervals during said cutting step. ### Claim 12 (depends on 10) A method according to claim 10, wherein said laser beam is displaced widthwise during said cutting step to form said undulating cut, and wherein each of said first and second metal tape strips has a continuous linear guide edge defining a lengthwise dimension and an opposite free edge extending in non-parallel relation with said guide edge as a result of said cutting step. ### Claim 13 (depends on 12) A method according claim 12, wherein said opposite free edge of each of said first and second metal tape strips has a saw tooth configuration. ### Claim 14 (depends on 12) A method according to claim 12, wherein, during said separating step, said first and second metal tape strips are displaced for movement in diverging paths. ### Claim 15 (depends on 14) A method according to claim 14, wherein one of said diverging paths leads to said coiling tool and the other of said diverging paths leads to a take-up reel. ### Claim 16 (depends on 12) A method according to claim 12, wherein said metal tape is made of high-tensile strength spring steel.