US809083A - Automatic electrical controller for air-compressors. - Google Patents

Description

P. D. AOKERMAN. AUTOMATIC ELECTRICAL CONTROLLER FOR AIR COMPRESSORS.

APPLICATION FILED MAY 17. 1905.

PATEN'I'ED JAN. 2, 1906.

3 SHEETS-SHEET 1.

ATTORNEYS N0. 809,083. PATENTED JAN. 2, 1906. P. D. AGKBRMAN.

3 SHEETS-SHEET 2.

W/T/VESSES: INVENTOR %4 Q.@ I FRED a HOKERMfl/V W By W ATTORNEY? PATENTED JAN. 2, 1906.

. F. D. AGKERMAN.

AUTOMATIC ELECTRICAL CONTROLLER FOR AIR GOMPRESSORS.

APPLICATION FILED MAYl'I, 1905.

N a n Q N m w E H mm ugfivnh EQTBJAJJMPAE M g 5 W 0 i I I .H h, l N Nw mfi R a ATTORNEYS the cylinder (see Figs. 2 and 5) is secured a Vertical bracket or bent arm 27, carrying a vertical tube 28. Within this tube a rod or plunger 29 is adapted to slide, the same having a lateral pin 30 working in a vertical slot in the tube 28, so that the rod is prevented from rotating. The lower end of the rod is provided with a roller'31, which is adapted to seat in the depressions or cavities 26, before referred to. A cylindrical screw 32, having a milled head, is applied to the upper end of the tube 28, which is screw-threaded internally at that point. Between the said screw and the slidable plunger 29 is arranged a spiral spring 33. It is apparent that by rotating the screw 32 the pressure of the same upon the spring 33 and the compression of the latter may be regulated, as desired, with the corresponding efiect of varying the pressure of the roller 31 in the depressions 26 of the cylinder 18.

As illustrated in Fig. 4c, the D-valve 3 is held to its seat by a spring 34. An exhaustport 35 is provided in the air-chest 2 adjacent to the port 36,that communicates with the pipe 11, which connects the air-chest with the lower air-cylinder 12.

Let it be supposed that the switch 22 is closed and that the motor is operating the pump to compress air. The valve 3 would then be, as shown in Fig. 4, connecting the left end of the cylinder 12 to the exhaust through ports 36 and 35. There being no pressure at the left of piston 13, the spring 17 would be fully expanded. As the air is compressed the piston 6 is gradually moved to the right against the tension of the spring 10, carrying valve 3 with it. WVhen the pressure is sufiiciently great, the port 26 is disconnected from the port 35 and connected to the interior of valve-chest 2, as shown in Fig. 1. Thereby air is admitted to the left of the cylinder 12, forcing piston 13 to the right against the pressure of spring 17 and compressing spring 19 until said latter spring overcomes the retaining influence of spring 33 and latch 31 and opens switch 32 with a snap action, whereby operation of the motor and air-compressor is arrested. Fig. 7 illustrates the compression of the spring 19 in casing 18 just previous to release of the latter from the spring-actuated latch 21, and Fig. 2 shows the position of said casing after such release. As air is drawn off from the storage-tank the airpressure falls in chamber 2, the spring 10 gradually moves piston 6 and valve 3 to the left, so as to cover ports 35 36, or at minimum pressure disconnecting port 36 from valve-chest 2 and connecting it to exhaustport 35, so that air escapes from cylinder 12 and piston 13 therein moves to the left, the switch 22 is closed, and the motor operates the pump to compress air again. This cycle of operation continues to maintain the pressure between certain maximum and minimum limits, which are determined by the adjustment of spring 10. It will be understood that when the piston 13 of cylinder 12 thus resumes its normal position (shown in Fig. 6) the slidable casing 18 and its contained spring 19 are also drawn back to normal position by engagement of the pin 21 of bar 15 with the adjacent head of, said casing. In this movement the spring 19 simply slides with the casing and has no function save in producing the automatic snap action before described.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. The improved automatic controller for the purpose specified, comprising a valve-chest and valve, an air-cylinder and a slidable piston contained therein and connected with said valve, a spring for opposing the movement of the piston in one direction, a second aircylinder having a spring-pressed piston, an air-conductor connecting such second cylinder with the valve-chest, a slidable bar connected with the last-named piston, a casing applied to and slidable on said bar, a spring contained within the said casing and applying pressure between it and the bar, an electrical switch one member of which is connected with the casing, and spring locking and release mechanism connected with the casing for holding it normally immovable and the switch normally closed until a certain predetermined air-pressure is accumulated, substantially as described.

2. The improved controlling apparatus for the purpose specified, comprising two aircylinders and pistons therein having springs for opposing movement in one direction, an air-chamber having a slidable Valve which'is connected with one of said pistons, a pipe connecting the air-chamber with a second cylinder, and an automatic locking and releasing mechanism connected with the piston of the second cylinder and comprising a slidable bar, a device that is slidable on said bar and provided with abutments or shoulders, a spring arranged between said device and a projection on said bar, and a spring-pressed latch adapted to engage with and automatically release said device, substantially as shown and described.

3. In a controller for the purpose specified, the combination with an air-cylinder, a piston slidable therein, a slidable bar extending therefrom and a guide in which said bar works, a casing applied to such bar and slidable thereon, a spring interposed between one portion of such casing and a stop on the bar, the casing having a top portion provided with depressions at opposite ends, a locking and releasing mechanism comprising aspringactuated plunger having at its free end a roller adapted to enter said depressions and thus lock the casing until the pressure of the plunger-spring is overcome, and a switch included in a motor-circuit and adapted to be broken when the air-pressure reaches a certain predetermined degree and the locking mechanism releases the cylinder which it engages, substantially as described.

4. In a controller for the purpose specified, the combination with an air cylinder and means for connecting it with an air-storage tank, of a piston which is slidable in said cylinder, a spring applied thereto for opposing movement in one direction, a bar connected with the piston and slidable therewith, a cas ing applied to the bar and slidable thereon, a spring inclosed by the casing and arranged between one end thereof and a stop on the bar, a casing having on its upper side engaging shoulders, a locking and releasing mechanism comprising a vertical tube having a FRED D. 'ACKERMAN.

Witnesses:

OSCAR WILLIAMS, W. G. WATKINS.

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