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).
Promotional document detailing the applications and operation of the Burgess Micro Switch.
| Identifier | ExFiles\Box 152\3\ scan0179 | |
| Date | 23th March 1936 guessed | |
| MICRO SWITCH APPLICATIONS DOOR SWITCHES Its small size and ease of mounting suit the Micro Switch to installation in doors of refrigerators and similar equipment for turning on lights automatically, or as a safety switch for opening the line circuit. AUTOMATIC MACHINERY Burgess Micro Switches are fitted for practically any job on automatic machines where a definite actuating pressure or motion is available and automatic electric control is desired. As a limit switch they provide .001″ accuracy of control. Successful applications of this type are too numerous to be listed. PRESSURE SWITCHES—WATER LEVEL CONTROL Burgess Micro Switches are well adapted for gas, steam, or liquid pressure controls, and for pressure safety devices. Operating with a pressure differential of approximately four ounces, and capable of handling line voltage for the control of solenoid or motorized valves, they make possible accurate control with simple mechanism. MOTOR OVERLOAD RELEASES The Micro Switch combined with a suitable thermal expansion element forms a compact motor overload release capable of handling a 1/2 H. {Arthur M. Hanbury - Head Complaints} P. AC motor. Such a device provides protection against burn-out from stalled rotor without being affected by high momentary starting currents. VIBRATOR CIRCUIT INTERRUPTER The Burgess Micro Switch is one of the few switches having the stamina to withstand vibrator service, as evidenced by its successful performance in Burgess neon flashing units. Its ability to withstand the millions of flexures required in such applications is provided by use of heat treated Beryllium Copper spring stock combined with a design which holds material stresses to a minimum. Because of low resistance provided by large silver contacts, the Micro Switch is practical for vibrators on as low as 1 1/2 volts. Its positive snap action assures a uniform vibrating period free of chattering and with a definite armature stroke. PRINCIPLE OF OPERATION THE operation of the Burgess Micro Switch depends upon producing a sufficient change in the relative forces of two opposing spring systems to cause the contacting silver plates to separate or come together with a positive snap action. The switch is so designed that the required changes in these forces are obtained when the operating plunger is depressed approximately one thousandth of an inch. In the normal position of the switch, the movable contact element, mounted on the main spring system, is held resiliently against the upper limiting stop. In the case of the normally closed switch, this stop is the stationary electrical contact, while in the normally open switch, it is an insulated stop. When a pressure of approximately 14 ounces is applied to the operating plunger, the plunger will have been depressed until the forces in the springs upon which the moving contact is mounted will have been altered sufficiently to cause that contact to leave the upper stop suddenly and assume the position shown in the phantom photograph. Subsequently, when the pressure acting upon the plunger is relieved, and as soon as it is reduced to approximately ten ounces, the plunger will have raised approximately one thousandth of an inch, and the spring forces will have regained their normal values, whereupon the moving contact will leave the lower stop suddenly and make contact with the upper stop. In this way a positive, quick action is obtained in both directions, assuring a definite snap action both in the making and breaking of electrical circuits. The successful commercial adaptation of this principle, in which long life and continued uniformity of performance are essential, is made possible largely by the use of beryllium copper for the moving elements. The high electrical conductivity of this material, combined with its ability to withstand millions of repeated stresses without fatigue, crystallization, or deformation, is responsible for the ability of the Burgess Micro Switch to provide precision, reliability and continuous operation. Phantom view of the Burgess Micro Switch, illustrating operation of Red Top Normally Closed Type. C. F. {Mr Friese} Burgess Laboratories, Inc., Freeport, Illinois PRINTED IN U. S. A. {Mr Adams} THERMOSTATS Small operating motion, positive snap action, make Burgess Micro Switches well suited to thermostatic controls. They have been used successfully in controls for domestic and industrial heating systems, ovens, deep frying equipment, incubators and brooders—operating with mercury, bimetal, and liquid or gas filled bellows as sensitive elements. Because of their sensitivity, combined with high current capacity at line voltage, Burgess Micro Switches make possible close temperature control without intermediate relays. RELAYS Because of their compact, easily mounted, dirt free construction, Burgess Micro Switches lend themselves readily to relay design. The extremely small armature stroke required results in high relay sensitivity. A positive control of one thousand watts AC is obtainable from four thousandths of an inch ounce of energy. CLOCK OPERATED CONTROLS For controls such as automatic process timers, refrigerator defrosters, day-night switches for heating systems, Burgess Micro Switches are well suited. So little energy is required that they can be operated directly from a cam on the second hand shaft of small electric clock motors; depending upon shape of the cam any desired cycle may be obtained. The housing is fully insulated and may be mounted directly upon metal parts. Current capacity is ample for practically all domestic motor-powered AC equipment. SIGN FLASHERS Micro Switches are well fitted for sign flasher service, being capable of standing the millions of operations required. They can be operated singly by an expanding medium with heater element, or in multiple by a set of cams—producing any flashing sequences or moving effects desired. A minimum of operating power is required. A flashing unit built with Micro Switches possesses compactness combined with ruggedness not obtainable with other switches. BURGESS MICRO SWITCH PATENT NO. 1,960,020 C. F. {Mr Friese} Burgess Laboratories, Inc. Freeport, Illinois from BURGESS PRODUCTS COMPANY PARWELL, LEICESTER. | ||