US2894704A

US2894704A - Snow blower control systems

Info

Publication number: US2894704A
Application number: US481467A
Authority: US
Inventors: Herbert L Bone
Original assignee: Westinghouse Air Brake Co
Current assignee: Westinghouse Air Brake Co
Priority date: 1955-01-12
Filing date: 1955-01-12
Publication date: 1959-07-14
Anticipated expiration: 1976-07-14

Description

July 14, 1959 H. L. BONE 2,894,704

SNOW BLOWER CONTROL SYSTEMS Filed Jan. 12, 1955 2 Sheets-Sheet 1 v BY 104.6 1?!- HIJ' HTTORIVEI July 14, 1959 H. LEONE v 2,894,704

' SNOW BLOWER CONTROL SYSTEMS Filed Jan. 12, 1955 2 Sheets-Sheet 2 v A za M i v. '20 1 57 B I 55 7 21 I I k {F58 I a1 50 l l 29 i "c IN V EN TOR.

Herben Z. B0129.

MAW

Patented July 14, 1959 fire SNOW BL'OWER CONTROL SYSTEMS Herbert L. Bone, Forest Hills, Pa, assignor to Westinghouse Air Brake Company, Wilmerding, Pa., a corporation of Pennsylvania Application January 12, 1955, Serial No. 481,467

4 Claims. (Cl. 246428) My invention relates to automatic snow removing devices, and particularly to an automatic snow blower control system for removing accumulated or falling snow, or other foreign material, from between the switch points and stock rails of a railroad switch.

Heretofore it has been the practice to remove snow from railroad switches by the use of heaters or burners located at strategic points along the rails of the switch for melting the snow in those areas where accumulated and packed snow interferes with the proper operation of the railroad switch. The heater or burner installations at the railroad switches are expensive to install and operate, the heater or burner systems requiring constant care and watchfulness during their operation. The prevalent snow melting devices are usually set in operation only after the snow has accumulated, an error in judgment as to the amount of snow accumulated on the switches, or an error in judgment as to the rate of snow accumulation causing Serious delays in the movement of trains over the pro tected switches when the snow melting devices are turned on and cannot melt the snow fast enough. With snow melting devices there is also the problem of disposing of the melted snow, proper drainage of the water being seriously hindered by the subsequent formation of ice.

It is therefore an object of my present invention to provide apparatus for the removal of snow or other foreign material from between the switch points and stock rails of a railroad switch before the snow or other material has accumulated to a degree where it interferes with the proper operation of the switch.

A further object of my invention is to provide an automatic snow blower system for removing the snow or other material from between the points and rails of a railroad switch by timed blasts of air directed between the movable points and fixed rails of the railroad switch.

Another object of my invention is to provide an automatic snow blower system of compact and rugged design comprising few and simple parts inexpensive to manufacture and readily assembled and disassembled, the parts being such that the timed intervals of the delivery of air blasts to clear the snow may be readily altered to provide a cycle of operation suited for the particular need.

In carrying out my invention, I provide a series of noz- 21% for manifolds which are secured to the inner surfaces of the stock rail webs, the nozzles being directed toward the movable points of the railroad switch. The manifolds are connected by suitable pipe lines to an electropneumatic control valve which is opened and closed at timed intervals. The control valve of my control system is connected in the air line of a reservoir or tank for supplying air under compression to the manifold nozzles. The reservoir or tank is charged from a suitable source as, for example, from an air compressor, or from the air lines prevalent in railroad yards.

The control of my snow blower system is effected by a throttling valve placed in the supply line of the reservoir, the valve being set to provide a predetermined charging ate for the reservoir in which time the pressure of the reservoir attains a predetermined value. My novel snow blower system is further augmented by a pressure switch and an electrical delay circuit for operating the electropneumatic control valve connected in the discharge line. The pressure switch may be set to close at any predetermined pressure within the reservoir. When the pressure in the system is of the predetermined value, the pressure switch closes to energize the electromagnet of the control valve to open the valve. The air under pressure is thus delivered to the nozzles. A capacitor is provided in the circuit of the electromagnet for the control valve, the charge on the capacitor holding the electromagnet energized for a predetermined time interval after the pressure switch opens upon decrease in the pressure of the air in the reservoir. With the throttling valve in the air supply line to the reservoir and the capacitor in the circuit of the electromagnet for the control valve, I am able to Provide a timing cycle of snow blower operation which meets the requirements of a particular switch location.

Another feature of the snow blower control system embodying my invention is the provision of electrical contacts in series with the pressure switch, the electrical contacts providing the means whereby the system may be set into operation manually or automatically from a point at the switch location or from a remote point as from a control tower.

Other objects and characteristic features of my invention will become apparent as the description continues.

I shall describe one form of an automatic snow blower embodying my invention, and shall then point out the novel features thereof in claims.

In the accompanying drawings wherein similar reference characters refer to similar parts in each of the several views,

Fig. l is a plan view of a typical railroad switch layout including my novel automatic snow blower.

Fig. 2 is a sectional view along line 11-11 of Fig. 1.

Fig. 3 is a side elevational view of a stock rail of a railroad switch showing the installation of the manifold and the snow blower nozzles, while Fig. 4 is a schematic diagram of my novel automatic snow blower control.

Referring now in detail to the drawings, the reference character ll designates in general a railroad switch secured in the usual manner to railroad ties 2, the switch comprising the

fixed rails

3 and 4 and the

movable rails

5 and 6. The

movable rails

5 and 6 are interconnected by a tie rod 7 which is connected by way of the usual coupling 8 to a throw rod 9 of a switch movement Ill secured to the ties 2. The movable rails or

switch points

5 and 6 have secured thereto circuit controller operating rods 11, the

outer ends of the operating rods being connected to the Y cranks 13 of circuit controllers 14 secured to the ties 2.

Secured to a suitable foundation 15 adjacent the fixed rail 3, is a snow blower control box 16 housing the automatic control elements illustrated schematically in Fig. 4. The elements of the control box are connected to a supply of compressed air via a suitable pipe or conduit 17. The conduit 17 is connected to a storage or reservoir tank 18 secured to a suitable foundation (not shown), the inlet of the tank being connected by air lines 19 through a suitable throttle valve 20 to a compressed air supply source (not shown). The elements of the control box 16 are connected by pipe lines 21 to manifolds 22 secured to the inner surface of the webs of stock rails 3 and 4 (Fig. 3) by clips 23 fastened to the rails as by bolts 24, the pipe lines passing through suitable openings 4a provided in the rail webs. The manifolds 22 are provided with a plurality of nozzles 25 facing in the direction toward the switch points to direct blasts of air toward the points to blow away any accumulation of snow or other particles as, for

3 example, sand or cinders, from between the switch points and the stock rails.

Referring now in detail to the elements of the snow blower control box 16 illustrated schematically in Fig. 4, the conduit 17 from the air reservoir tank 18 is connected by a T-connection 26 to the inlet side of an electropneumatic control valve 27 of a standard design, and to a pres-- sure switch 28 of the Bourdon type. The outlet of the valve 27 is connected to the pipe lines 21 coupled to the nozzle manifolds 22. The valve 27 includes an operating winding or electromagnet 29 having one end thereof connected by a wire 30 to the terminal C of a suitable power supply while the other end of the winding is connected by a wire 31 to a stationary contact 32. The contact 32 is adapted to be engaged by a contact 33 controlled by the Bourdon tube 28, the arrangement being such for the installation illustrated that contacts 3233 will be closed when the air pressure in the tank is 80 pounds per square inch or more. The contact 33 is connected by a wire 34 through a suitable resistor 35 and through

contacts

35, 37 to the B terminal of the power supply. The

contacts

36, 37 may be closed and opened locally as by a manual push button, or they may be the contacts of a relay controlled from some remote point, as, for example, from a control tower. A timing condenser or capacitor 38 is connected across the

wires

30 and 31 in parallel with the operating winding 29 of the valve 27 for reasons hereinafter appearing.

In the operation of the automatic snow blower control described, the valve 24) is adjusted so that the air pressure within the reservoir reaches a predetermined value within a suitable time after the air has been discharged by the operation of the valve 27. By way of example, and with the reservoir 18 connected to a suitable source of compressed air, the valve 2i} is adjusted so that it takes approximately thirty seconds to build up a pressure of 80 pounds per square inch within the tank. With the contacts 3233 of the pressure switch adjusted to close when the pressure reaches 80 pounds per square inch and with the control contacts 3637 closed, an obvious circuit is completed for the electromagnet 29 to open the valve 27. The air under pressure in tank 18 passes through the valve 27 and is expelled in a blast from the manifold nozzles 25 to clear away the falling or accumulated snow and the like from between the points and the fixed rails. Quite obviously the pressure within the tank 18 falls quickly to a value below the 80 pounds per square inch at which the pressure switch contacts 3233 are closed. Under ordinary circumstances, the contacts 32-33 would open almost immediately after the valve 27 was opened, in which event the valve 27 would again close to shut off the air supply to the manifold nozzles. It has been found however that the valve 27 should remain open for some time, about one to four seconds, to provide an air blast period of suitable duration to blow away the snow. The timing condenser 38, connected in parallel with the electromagnet 29 of the valve, maintains the electromagnet in its energized condition for a predetermined period after the pressure switch contacts 3334 have been opened to hold the valve 2'7 open. Thus a timing cycle is established for removing the snow from between the switch points by blasts of air by the components of the electromagnet circuit and by the setting of the throttle valve in the supply line 19 for the tank 18. The one to four seconds air blast and thirty seconds charging time herein described has proven to be an ideal timing cycle for removing accumulated and falling snow. It will be readily apparent that any desired timing cycle for the operation of the snow blower may be easily established by including a condenser 38 of a particular value to provide the slow release time of the magnet 29 and/ or setting the throttling valve 20 for a particular charging time of the tank 18.

The automatic snow blower control system I have provided forms a compact unit of rugged design comprising few parts inexpensive to manufacture and readily assembled or disassembled, the control system providing a positive and accurate control of the air blasts for removing the snow from between the movable points and stock rails of a railroad switch. It will be readily appreciated that my novel control for snow blowers and the like is not necessarily limited to the clearing of railway switches but may readily be used in controlling the air blasts for clearing right-of-ways, roadways, runways and the like of snow or other accumulating material. The control system is such that any desired timing cycle for the delivery of the air blasts to the manifold nozzles may be readily set or altered to meet particular conditions at different locations, the control system being such that manual or automatic initiation of the blower operation may be controlled either locally or from a remote control point.

Although I have herein shown and described only one form of a snow blower control system embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. A fluid pressure operated blower comprising at least one nozzle directed toward a predetermined area, a source of fluid pressure, a reservoir connected by a first conduit to said source and by a second conduit to said nozzle, a throttling valve in said first conduit for controlling the charging rate of said reservoir to a predetermined pressure, a pressure switch actuated by the fluid pressure in said reservoir of the predetermnied value, a control valve in the second conduit, means including an electromagnet for opening said control valve upon actuation of said pressure switch, and means including a time delay circuit for said electromagnet for maintaining said valve open a predetermined period after the pressure in said reservoir falls below the predetermined value.

2. In a fluid pressure operated blower for a railroad switch having a plurality of interconnected nozzles directed toward the spaces between the switch points and the stock rails, the combination comprising, a source of fluid under pressure, a reservoir connected by a first conduit to said source and by a second conduit to said nozzles, valve means in said first conduit for controlling the charging rate of said reservoir to a predetermined pressure, a control valve in said second conduit, an electromagnet for opening said control valve upon energization thereof, said control valve closing upon deenergization of said electromagnet; a pressure switch including normally open contacts actuated by the fluid pressure of said reservoir when the pressure is of the predetermined value to close said contacts; an electrical circuit including in series a source of electrical power, said pressure switch contacts, and said electromagnet; said pressure switch when closed energizing said electromagnet to open said control valve, and electrical impedance means for maintaining said electromagnet energized a predetermined time after said pressure switch contacts are open upon the reduction of the pressure within said reservoir by the opening of said valve.

3. In a fluid pressure operated blower for a railroad switch having a plurality of interconnected nozzles directed toward the spaces between the switch points and the stock rails, the combination comprising, a source of fluid under pressure, a reservoir connected by a first conduit to said source and by a second conduit to said nozzles, valve means in said first conduit for controlling the charging rate of said reservoir to a predetermined pressure, a control valve in said second conduit, an electromagnet for opening said control valve upon energization thereof, said control valve closing upon deenergization of electromagnet; a pressure switch including normally open contacts actuated by the fluid pressure in said reservoir when the pressure is of the predetermined value to close said contacts; an electrical circuit including in series a source of electrical power, said pressure switch contacts, and said electromagnet; a normally open pair of contacts in series with said pressure switch contacts; said pressure switch and pair of contacts when closed energizing said electromagnet to open said control valve when the fluid pressure in said reservoir reaches said predetermined pressure, and capacitor means for maintaining said electromagnet energized a predetermined time after said pressure switch contacts are open upon the reduction of the pressure within said reservoir by the opening of said control valve.

4. In a fluid pressure operated blower for a railroad switch having a plurality of interconnected nozzles directed toward the spaces between the switch points and stock rail, the combination comprising, a source of fluid under pressure, a reservoir connected by a first conduit to said source and by a second conduit to said nozzles, a throttling valve in said first conduit for controlling the charging rate of said tank to a predetermined pressure, a control valve in said second conduit, an electromagnet for opening said control valve upon energization thereof, said control valve closing upon deenergization of said electromagnet; a pressure switch including normally open contacts actuated by the fluid pressure of said reservoir when the pressure is of the predetermined value to close said contacts; an electrical circuit including in series a source of electrical power, a normally open pair of contacts, said pressure switch, and said electromagnet; and a capacitor connected in parallel with said electromagnet, whereby closing said normally open contacts initiates cyclic energization of said eleetromagnet when said pressure switch is closed and deenergization of said electromagnet when said pressure switch is open after a delay time determined by said capacitor to cyclically operate said control valve to discharge fluid to said nozzles.

References Cited in the file of this patent UNITED STATES PATENTS 1,876,013 Livingston Sept. 6, 1932 1,990,521 Bone Feb. 12, 1935 2,361,466 Fitzsimmons Oct. 31, 1944 2,677,047 Mishelevich Apr. 27, 1954 2,700,519 Gilmore et a1. Jan. 25, 1955 2,784,928 Logan Mar. 12, 1957