| Title of Invention | ROLLER CHAIN SPROCKETS |
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| Abstract | A roller chain sprocket for clutch assembly, said sprocket comprising an integrally moulded toothed body made of a polymer and a circular metallic hub with formation on the periphery of the hub for fastening the toothed body to the hub during moulding and in use. |
| Full Text | FORM - 2 THE PATENTS ACT, 1970 (39 of 1970) & THE PATENTS RULES, 2003 PROVISIONAL Specification (See section 10 and rule 13) ROLLER CHAIN SPROCKETS HIGH TECHNOLOGY TRANSMISSIONS (I) PVT. LTD., an Indian Company of K-226, MIDC WALUJ, Aurangabad-431 136, Maharashtra, India, THE FOLLOWING SPECIFICATION DESCRIBES THE INVENTION. This invention relates to roller chain sprockets. Conventional roller chain sprockets which are part of a clutch assembly and are made of forging grade metals and are forged, machined & heat-treated . They constitute almost 25% of the cost of the complete clutch assembly. A power transmitting sprocket using a roller chain is required to have strength, anti-wear properties, sustenance to dynamic loading. These design requirements of roller chain automatically leads to a over-designed chain sprocket ( Factor of safety above 100). The major cost elements for a conventional sprocket are 1. RM forging material(35 to 45%), 2. CNC machining(8 to 14%), 3. Tooth Hobbing( 20 to 30%), 4. Heat Treatment ( 10 to 15%). An object of the present invention is to provide a roller chain sprocket which is less expensive and at the same time has all the design requirement of a conventional roller chain sprocket. Typically, it is required that the roller chain sprocket must withstand operating conditions for more than 15 years & more than 100000 Km of vehicle running. 2 The invention envisages having a sprocket which is partially of metal in the centre, in the form of a metal insert and a periphery of a special grade of plastic having following characteristics a. Sharp melting point b. Good mechanical strength( Minimum 3 Mpa in tension), c. Excellent oil aging properties, d. Exceptionally good dimensional stability & e. Good Anti-wear properties. The sprocket teeth are of the polymeric material and generated through regular hobbing process. The invention will now be described with reference to the accompanying drawing which shows the plan view of the roller chain sprocket in accordance with this invention. The sprocket 10, comprises a central metallic circular plate 12 and a periphery 14 having plastic teeth. Power transmission from plastic teeth to center metallic plate is done through the teeth inserts which provide engagement between two bodies. Samples tested for endurance as well as in accelerated testing methods & under heavily loaded abusive conditions passed all the testing. Extensive trials have been taken . A saving of 30% is achieved without deterioration of performance. 3 The special polymeric material goes by the name "Stanyl" Stanyl is a high performance, high temperature polyamide This highly crystalline polyamide has mechanical properties with a temperature capability of up to 280° F. The high crystallinity of the resin contributes not only to the wear characteristics of the polymer but also the rate that this crystallization occurs in the mold leads to some accelerated process cycle times. Stanyl's performance characteristics include good mechanical properties at high temperatures, resistance to wear, low friction as well as chemical resistance. Stanyl is light in weight In addition to having excellent heat resistance, it has low creep effects and retention of stiffness at elevated temperatures. Properties of Stanyl Property Value ► Dimensional stability ,-.- -?. H20 absorption 24 hours 1.3-3.7% Shrinkage 1.5-2% ►.Electrical performances Dielectric constant 3.4-3.8 Dielectric rigidity 15 - 25 kv/mm Dissipation factor 190-600 10A-4 Volume resistivity 15 10AXOhm.cm ►Fire performances- Fire resistance (LOI) 24% Flammability UL94 HB ■ ■ ■►Mechanical properties Elongation at break 160-300% Flexibility (Flexural Modulus) l-3.2GPa Hardness Rockwell M 92 Stiffness (Flexural Modulus) 1 - 3.2 GPa Strength at break (tensile) 65 - 85 MPa Strength at yield (tensile) 65 - 85 MPa Toughness (Notched Izod impact at room temperature) 30 - 250 J/m Young modulus 1 - 3.3 GPa ►Physical properties . .-.■:■*-:- Density : 1.17 - 1.19 g/cmA3 ► Radiation resistance ■ ..'. Gamma radiation resistance Fair UV light resistance Fair ►Service temperature [email protected](261psi) 150-155 °C Max continuous Service temperature 110-150 °C Min continuous service temperature -40 °C ► Others ._.. . _ - ;^H Thermal insulation (Thermal conductivity) 0.3 W/m.K While considerable emphasis has been placed herein on the specific structure of the preferred embodiment, it will be appreciated that many alterations can be made and that many modifications can be made in the preferred embodiment without departing from the principles of the invention. These and other changes in the preferred embodiment as well as other embodiments of the invention will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly 5 understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation. Dated this 18th day of august 2006. 6 |
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| Patent Number | 270525 | |||||||||
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| Indian Patent Application Number | 1305/MUM/2006 | |||||||||
| PG Journal Number | 01/2016 | |||||||||
| Publication Date | 01-Jan-2016 | |||||||||
| Grant Date | 29-Dec-2015 | |||||||||
| Date of Filing | 21-Aug-2006 | |||||||||
| Name of Patentee | HIGHTECHNOLOGY TRANSMISSIONS (I) PVT.LTD | |||||||||
| Applicant Address | K-226, MIDC, WALUJ, AURANGABAD 431 136, | |||||||||
Inventors:
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| PCT International Classification Number | F16435/00,F02B67/06 | |||||||||
| PCT International Application Number | N/A | |||||||||
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