From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Patent specification for an electric starter system incorporating an auxiliary battery.
| Identifier | ExFiles\Box 147\2\ scan0308 | |
| Date | 1st March 1939 | |
| 4 515,731 ary battery from the negative to the positive terminals thereof, whereas when the auxiliary battery is on charge the charging current must be passed through said battery in the reverse direction. This object is achieved by the arrangement shown. As will be seen, the high resistance 27 is wired in series with the main battery 1 and the negative side of said resistance is connected to a contact 28 into contactual relationship with which the switch 25 is moved whenever the starter button 9 is depressed to close the starter circuit. Normally, that is to say when the starter switch 4 is open, the switch 25 co-operates with a contact 29 which is connected to earth as indicated at 30. The side of the resistance remote from the contact 28 is connected with another contact 31 with which the switch 26 is normally in contactual relationship. When, however, the starter switch is closed, the switch 26 is drawn over into engagement with a contact 32 which latter is thereby connected with the contact 22 by way of the branch 33. Assume now that the ignition key has been turned to close the switch 2 and that the button 9 has just been depressed to effect closure of the starter switch 4 (as indicated in dotted lines); then, current will flow from the negative to the positive terminals of the main battery 1, through the switch 2, along the branch 34, through the switch 4 to the relay 18 and thence to earth at 21 with the result that the relay is excited to pull over all three switches 17, 25 and 26 simultaneously into engagement with the contacts 22, 28 and 32 respectively—as indicated in dotted lines. By reason of the said switches being moved over in this way the auxiliary battery 16 is brought into circuit with the main battery 1 and the resistance 27 is cut out of circuit. This will be clear from a consideration of the full line arrows which, as well as indicating that current is passed through the relay 18 also shows that current flows from the main battery along the branch 35, through the switch 25, thence through the auxiliary battery 16 from the negative to the positive terminals thereof, through the switch 26, along the branch 33, and, by way of the switch 17, through the primary winding of the ignition coil 3 and thence to earth at 8. Consider now the case where the engine has been started and is running. In these circumstances the starting motor 5 is cut out and the switches 17, 25 and 26 are in the full line positions shown. Consequently current from the battery 1 will then flow along the paths represented by the dotted arrows. That is to say it will flow along the branch 35, through the switch 17 and thence through the primary winding of the coil 3 before passing to earth at 8; but it will also flow through a parallel path including the high resistance 27. Hence it will also flow through said resistance, through the switch 26, through the battery 16—but from the positive to the negative terminals thereof—and thence to earth (30) by way of the switch 25. Under these conditions, whenever the main battery 1 is being automatically charged current therefrom, suitably reduced by the high resistance 27, also passes through the auxiliary battery 16 for the purpose of charging it. As hereinbefore mentioned, however, by placing the ignition switch 2 in an appropriate position in the primary ignition circuit, the auxiliary battery may be permanently on charge. In this way it can be left on charge even when the engine is not running. Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is:— 1. An electric starter system for an internal combustion engine incorporating one or more engine starting devices adapted to be operated from a battery, characterised by the provision therein of an auxiliary battery which is so arranged as to be brought into circuit with the main battery to supplement the latter upon closure of a starter switch, for the purpose specified. 2. An electric starter system for an internal combustion engine employing battery coil ignition, characterised by the provision therein of an auxiliary battery which is so arranged as to be brought into circuit with the customary battery to supplement the latter upon closure of a starter switch, so that when starting the engine a voltage at least equivalent to the rated value of the main battery is immediately applied to the ignition coil. 3. A system as claimed in Claim 1 or 2 which is of the single pole type with earth return. 4. A system as claimed in Claim 1, 2 or 3, wherein the starter switch has associated therewith an auxiliary switch which is adapted, upon closure of said starter switch to bring the auxiliary battery temporarily into circuit and in series with the main battery to boost up the latter. 5. A system as claimed in the last preceding Claim, wherein the said auxiliary switch is mechanically connected to and thereby follows the movements of the starter switch. 515,731 5 6. A system as claimed in Claim 1, 2 or 3, wherein there is provided for bringing the auxiliary battery into circuit for starting, an independent switch adapted to be influenced by a relay which is in circuit with and excitable upon closure of the starter switch. 7. A system as claimed in the last preceding claim, wherein the relay is in the form of an electro-magnetic device. 8. A system as claimed in any of the preceding claims, wherein provision is made whereby the auxiliary battery can be automatically charged from the main battery. 9. A system as claimed in the last preceding claim, wherein there is provided a resistance, which is located between the main and auxiliary batteries, and means associated with said resistance whereby it can be automatically cut out of circuit at such times as the starter switch is closed, for the purpose specified. 10. A system as claimed in Claims 6 or 7, wherein the resistance is connected in parallel with the primary circuit of the ignition coil and is adapted to be put into and out of circuit upon opening and closure of the starter switch respectively by switch means which are connected and operable with the aforesaid independent switch. 11. A system as claimed in Claim 8, 9 or 10, wherein whenever the main battery is being charged during running of the engine current therefrom is passed through the auxiliary battery for charging purposes. 12. A system as claimed in Claim 8, 9 or 10, wherein the auxiliary battery is left permanently on charge. 13. An electric starter system for an internal combustion engine which is adapted to function substantially in any of the ways herein described with reference to the accompanying drawings. DATED this 1st day of March, 1939. FREDERICK LEE WITCOMB, E.{Mr Elliott - Chief Engineer} N. Lewis & Taylor, Chartered Patent Agents, Berridge Street Chambers, Leicester, Agents for the Applicant. Leamington Spa: Printed for His Majesty's Stationery Office, by the Courier Press.—1940. | ||