US2784928A

US2784928A - Snow blower control systems

Info

Publication number: US2784928A
Application number: US507582A
Authority: US
Inventors: Jr John W Logan
Original assignee: Westinghouse Air Brake Co
Current assignee: Westinghouse Air Brake Co
Priority date: 1955-05-11
Filing date: 1955-05-11
Publication date: 1957-03-12
Anticipated expiration: 1974-03-12

Description

March 12, 1957 J. w. LOGAN, JR 2,784,928

SNOW BLOWER CONTROL SYSTEMS Filed May 11, 1955 2 Shee ts-Sheet 1 I MI 4 EN TOR. ug I N V His ATTORNEY John "(Logan .ln

March 12, 1957 J. w. LOGAN, JR

snow BLOWER CONTROL SYSTEMS 2 Sheets-Sheet 2 I '20 VA. P4

Filed May 11, 1955 ll --l To Hanii'ald 012 1Zal'l4 INVENTOR.

John W Loyan Ji' BY 10. A, W.

HIS ATTORZVEY To fiam'fald 011 Rail 3 1 United States PatentO SNOW BLOWER CONTROL SYSTEMS John W. Logan, Jr., Forest Hills, Pa., assignor to Westinghouse Air Brake Company, Wilmerding, Pa., a corporation of Pennsylvania Application May 11, 1955, Serial No. 507,582

11 Claims. (Cl. 246-428) My invention relates to automatic snow removing devices, and particularly to an automatic snow blower con trol system for removing accumulated or falling snow, or other foreign material, from between the switch points and stock rails of a railroad switch.

It has been the practice in most instances in the past 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. With snow melting devices there is 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 autov matic 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 nozzles 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 such, for example, as an air compressor, or from the air lines prevalent in railroad yards.

My novel snow blower control system includes two pressure responsive devices connected in the discharge line of the pressure reservoir, each of the devices controlling a pair of electrical contacts. The pressure actuated cont acts are connected in a relay circuit for controlling the operation of the control valve of the system. With fluid pressure in the system above a predetermined value, the electrical circuit is such that operation of the blower may be initiated from a remote point either by way of a push button, a relay, or by control devices of various kinds.

2,784,928 Patented Mar. 12, 1957 The electrical contacts controlled by the pressure re= sponsive devices in the reservoir discharge line are actuated by their respective pressure devices so that one pair of contacts is closed when the fluid pressure falls below the one predetermined value and the other pair of contacts is closed below a second predetermined pres= sure value. The opening and closing of the pressure actuated contacts control the operation of the relay to provide a cycle of operation for the control valve which permits timed blasts of air to be directed at the switch points to clear away the snow or other material tending to hamper the proper operation of the switch. The snow blower control system described is further characterized by its adaptability to the various requirements of particular installations.

I shall describe two forms of automatic snow blowers 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 the 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.

Fig. 4 is a schematic diagram of my novel automatic snow blower control, while i Fig. 5 is a schematic diagram of a modification of my snow blower control whereby the blasts of air are directed only at the open switch points.

Referring now in detail to the drawings, the reference character 1 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 10 secured to the ties 2. The movable rail or switch point 6 has secured thereto a circuit controller operating rod 11, the outer ends of the operating rod being connected to the crank 12 of a circuit controller 13 secured to the ties 2.

Secured to a suitable foundation 14 adjacent the fixed rail 3 and between two ties 2, is a snow blower control box 15 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 16. The conduit 16 is connected to a storage or reservoir tank 17 secured to a suitable foundation (not shown), the inlet of the tank being connected through a throttling valve 18 to a compressed air supply source (not shown). The elements of the control box 15 are connected by pipe lines: 19 to manifolds 20 secured to the inner surface of the webs of stock rails 2 and 3 (Fig. 3) by clips 21 fastened to the rails as by bolts 22, the pipe lines passing through suitable openings 4a provided in the rail webs. The manifolds 20 are provided with a plurality of nozzles 23 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 example, sand or cinders, from between the switch points and the stock rails.

Referring now in detail to Fig. 4 illustrating schematically the elements of my novel snow blower control system, the conduit 16 from the fluid pressure reservoir 17 is connected to the inlet conduit 24 of an electropneumatic control valve 25 of a standard design, the outlet or discharge port 26 of the control valve being connected to a manifold conduit 19. Connected into the conduit 16 are two T-

connections

27 and 28 serving as connections for two pressure responsive devices or switches 29 and of the Bourdon type. The pressure responsive switch 29 is preset or adjusted to close its contacts 31-32 when the pressure in the reservoir conduit falls below a predetermined value, while the pressure 31-32 when the pressure falls below 55 pounds per square inch and with the pressure switch 30 set to close contacts 33-34 when the pressure in the system falls below 80 pounds per square inch.

The closing and opening of the contacts 31-32 and 33-34 by their respective pressure responsive devices control the operation of a relay 35. One end of the operating coil of the relay is connected to the N terminal 'of a suitable source of power supply, while the other end is connected by lead 36 to the contact 32, and by a lead 37 over the front contacts 38 of the relay to the "contact 34 of the pressure switch 30. The contact 31 of the pressure switch 29 is connected to a common lead '40 and through normally open contacts 41-42 to the "B terminal of the power supply. The contacts 41-42 may be closed and opened either locally or at a remote point by manual means as, for example, a push button, or by a relay or other control device.

The common lead 40 is connected to the contact 33 of the pressure switch 30 and by a lead 44 over the back 'contact 45 of the relay to one end of a solenoid operating coil 46 for the control valve 25. The other end of the operating coil 46 is connected to the N terminal of the power supply.

In the operation of the automatic snow blower control described, the throttling valve 18 is adjusted so that the air reservoir 17 is charged from the air supply source within a suitable time after the air has been discharged by the operation of the control valve 25. By way of example and with the reservoir 17 connected to a suitable air source, the throttling valve 18 is adjusted so that it takes approximately thirty seconds to build up a pressure of 80. pounds per square inch in the reservoir.

With pressure in the reservoir above the preferable predetermined pressure, the contacts 31-32 and 33-34 will beheld open by their respective pressure

responsive members

29 and 30. Closing the contacts 41-42 by any suitable means will complete an energizing circuit for the solenoid operating coil 46 from the B terminal "of the power supply over the leads and 44, over the closed back contacts of the deenergized relay 35 to "the N terminal of the power supply. The energization of the operating coil 46 will open the control valve 25 to permit the air under pressure to flow through the delivery duct 19 to the nozzle manifolds 20 secured to the

stock rails

3 and 4. The pressure in the system is quickly reduced upon opening of the control valve 25.

When the pressure within the system falls below 80 pounds per square in as the air is delivered to the 'nozzles 23, the contacts 33-34 of the pressure switch 30 close. A holding circuit is thus partially completed for the deenergized relay 35 from the B terminal of the power supply, through lead 40 and resistor 43, the closed contacts 33-34 to the open front contacts 38 of the 'relay. The continued delivery of the air to the snow blower nozzles 23 Will reduce the pressure in the system still further until the pressure falls below the previously indicated pressure of pounds per square inch. The pressure switch 29 will then close to complete an energizing circuit for the relay 35 from the B terminal of the power supply, through lead 40, over the closed contacts 31-32 and through the relay coil to the N terminal of the power supply. The energized relay 35 will now open its back contact 45 to deenergize the solenoid operating coil 46 of the control valve 25, thereby cutting off the air supply to the snow blower nozzles 23. The energized relay also closes its front contact 38 to complete a holding circuit for the relay over the closed contacts 33-34 of the pressure switch 30.

With the air supply cut off from the snow blower nozzles 23, the air pressure in the reservoir 17 will be built up again from the compressed air supply source. When the pressure exceeds 55 pounds per square inch, the pressure switch 29 will open its contacts 31-32. The relay, however, will be held energized by the stick or holding circuit previously described over the front contact 38 and the contacts 33-34 of the pressure switch 30. When the pressure in the reservoir again exceeds pounds per square inch, the pressure switch 30 opens the contacts 33-34 to deenergize the relay 35. The back contact 45 of the relay is again closed to complete the energizing circuit for the solenoid operating winding 46 of the control valve 25. The cycle of operation is repeated as long as the contacts 41-42 remain closed, the air being delivered to the nozzles in the form of blasts of about three seconds-duration with a delay between blasts while the resorvoir 17 is being recharged of about a thirty-seconds duration. It Will be appreciated that a different timing cycle may be readily provided by adjustment of the throttling valve 18 in the charging line of the reservoir 17 and by adjusting the pressure switches 29 and/ or 39 so that the contacts 31-32 and/ or 33-34 will be closed and opened at pressures other than those herein specified.

In Fig. 5 of the drawings I have illustrated a modification of my novel snow blower control whereby blasts of air are directed at the open switch points only. In the modification illustrated, two control valves 25a and 25b are connected to the reservoir outlet conduit 16. The delivery line 19a of valve 25a is connected to the manifold 20 secured to the stock rail 3 of the railroad switch 1, while the delivery line 19b of the valve 25b is connected to the manifold 20 secured to the stock rail 4 of the switch. The solenoid operating coils 46a of the control valves are connected by leads 47a and 471) through circuit controller contacts 48a and 48b, re-

spectively, through a common lead 49 to the back contact 45 of the relay 35. As illustrated in Fig. 5, the circuit controller operating rod 11 movable with the switch points closes the circuit controller contacts 48a while opening the contacts 48b when the railroad switch is in its normal position as illustrated in Fig. l of the drawings. The energizing circuit for operating coil 46a of the control valve 250 may thus be completed over the closed circuit controller contacts 48a so that air is passed through the delivery line 19a to the open point 5. When the switch 1 is in its reverse position with the point 5 against the stock rail 3 and the point 6 open, the circuit controller contacts 48a are open and the contacts 481) closed by the circuit controller operating rod. Only the control valve 2512 will be operated in this position of the switch 1, the blasts of air being delivered to the open point 6 of the switch. It will be appreciated that by selectively controlling the air delivered to the nozzle manifolds so that blasts of air are directed only toward the open switch point, only half the quantity of air is required in keeping the switch 1 clear of snow or other material.

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 railroad switches but may readily be used in controlling the air blasts for clearing r-ight-of-ways, roadways, runways and the like of snow or other accumulater or 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 condi tions at different locations, the control system being such that manual or automatic initiation of the blower operation may be controlled either locally or fromja remote control point.

Although I have herein shown and described two forms 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:

l. A fluid pressure operated device comprising at least one nozzle directed toward a predetermined area, a source of fluid pressure, a reservoir connected to said-source and to said nozzle, an electromagnetically operated control valve for controlling the exhaust of fluid from said reservoir to said nozzle, pressure actuated means for operating said control valve including electrical contacts actuated when the fluid pressure of said reservoir falls below a first predetermined pressure and when said pressure falls below a second predetermined pressure, and electrical circuit including said pressure actuated contacts, and relay means in said circuit controlled by said pressure actuated contacts for opening said control valve when the pressure in said reservoir is above the first predetermined pressure and maintaining the control valve open while the pressure falls to the second predetermined pressure, said relay controlling the closing of said control valve when the pressure falls below the second predetermined pressure and maintaining the control valve closed until the pressure in said reservoir rises to the first predetermined pressure.

2. A fluid pressure operated device comprising at least one nozzle directed toward a predetermined area, a source of fluid pressure, a reservoir connected to said source and to said nozzle, means for controlling the charging rate of said reservoir from said source; a control valve includingan electromagnetic operator for controlling the exhaust of fluid from said reservoir to said nozzle, first pressure operated contacts actuated when the reservoir pressure falls below a first predetermined pressure, second pressure operated contacts actuated when the reservoir pressure falls below a second predetermined pressure, a relay including front and. back contacts, and an electrical circuit for the electromagnetic valve operator, the pressure operated contacts and the relay; said electromagnetic operator being energized over a back contact of the relay to open said valve when the reservoir pressure is above the first predetermined pressure and maintained energized as the reservoir pressure falls below the first- :predeterrnined pressure to the second predetermined pressure, said electromagnetic operator being deenergized to close said valve upon energization of said relay when the-reservoir pressure falls below said second predetermined pressure and maintained deenergized during the recharging of said reservoir until the reservoir pressure is higher than first predetermined pressure.

3. A fluid pressure operated device comprising at least one nozzle directed toward a predetermined area, a source of fluid pressure, a reservoir connected to said source and to said nozzle, 21 control valve including an electromagnetic operator for controlling the exhaust of fluid from said reservoir to said nozzle, and an electrical circuit for controlling the energization of said electromagnetic operator, including a first pair of pressure operated contacts actuated when the reservoir pressure falls below a first predetermined pressure, a second pair of pressure operated contacts actuated when the reservoir pressure falls below a second predetermined pressure lower than said first predetermined pressure, a relay including front and back contacts, and means for energizing said electromagnetic operator over a relay contact to open said valve when the reservoir pressure is above the first predetermined pressure, said relay being energized to open the energizing circuit of said electromagnetic operator upon actuation of said second pair of pressure operated contacts when the reservoir pressure falls below the second predetermined pressure and being maintained energized over a relay contact and the actuated first pair of pressure operated contacts as the reservoir pressure builds up to the first predetermined pressure. 4. A fluid pressure operated device comprising at lea one nozzle directed toward a predetermined area, a source of fluid pressure, a reservoir connected to said source and to said nozzle, a control valve including an electromagnetic operator for controlling the exhaust of fluid from said reservoir to said nozzle, and an electrical circuit for controlling the energization of said electromagnetic operator, including a first pair of pressure operated contacts adapted to close when the reservoir pressure falls below a first predetermined pressure, a second pair of pressure operated contacts adaptedto close when the reservoir pressure falls below a second predetermined pressure lower than said first predetermined pressure, a relay including front and back contacts, and means for energizing said electromagnetic operator over a back contact of said relay to open said valve when both pairs of pressure operated contacts are open, said relay being energized to open the energizing circuit of said electromagnetic operator upon closure of said second pair of pressure operated contacts and being maintained energized over a front contact of the relay as long as the first'pair of pressure operated contacts remains closed. 5. A fluid pressure operated device comprising at least one nozzle directed toward a predetermined area, a source of fluid pressure, a reservoir connected to said source and to said nozzle, a control valve including an electromagnetic operator for controlling the exhaust of fluid from said reservoir to said nozzle, and an electrical circuit for controlling the energization of said electromagnetic operator including normally open controlling contacts, a first pair of pressure operated contacts adapted to close when the reservoir pressure falls below a first predetermined pressure, a second pair of pressure operated contacts adapted to close when the reservoir pressure falls below a second predetermined pressure lower than said first predetermined pressure, and a relay including front and back contacts, said electromagnetic operator being energized over a back contact of said relay to open said valve upon closure of the controlling contacts when both pairs of pressure operated contacts are open, said relay being energized to open the energizing circuit of said electromagnetic operator upon closure of said second pair of pressure operated contacts and being maintained energized over a front contact of the relay as long as the first pair of pressure operated contacts remains closed.

6. A fluid pressure operated device comprising at least one nozzle directed toward a predetermined area, a source of fluid pressure, a reservoir connected to said source and to said nozzle, means for controlling the charging rate of said reservoir from said source, a control valve including an electromagnetic operator for controlling the exhaust of fluid from said reservoir to said nozzle, and an electrical circuit for controlling the energization of said electromagnetic operator including normally open controlling contacts, a first pair of pressune operated contacts adapted to close when the reservoir pressure falls below a first predetermined pressure, a second pair of pressure operated contacts adapted to close when the reservoir pressure falls below a second predetermined pressure lower than said first predetermined pressure, and a relay including front and back contacts, said electromagnetic operator being energized over a back contact of said relay to open said valve upon closure of the controlling contacts when both pairs of pressure operated contacts are open, said relay being energized to open the energizing circuit of said electromagnetic operator upon closure of said second pair of pressure operated contacts and being maintained energized over a front contact of the relay as long as the first pair of pressure operated contacts remains closed.

7. A fluid pressure operated blower for a railroad switch comprising, at least one nozzle for each switch point directed to deliver a fluid blast between the switch point and the adjacent rail to clear snow, sand and other material from between the switch point and the rail, a source of fluid under pressure, a reservoir connected to said source and to each of said nozzles, a control valve for .each nozzle including an electromagnetic operator for controlling the exhaust of fluid from said reservoir to each of said nozzles, and an electrical circuit for selectively controlling the energization of each of the electromagnetic operators including circuit controller contacts selectively actuated when the switch occupies its normal position and predetermined pressure to open the selected control valve for exhausting the reservoir fluid between the one point and its adjacent rail.

.8. A fluid pressure operated blower for a railroad switch comprising, at least one nozzle for each switch point directed to deliver a fluid blast between the switch point and the adjacent rail to clear snow, sand and other material from between the switch point and the rail, 8. :source of'fluid under pressure, a reservoir connected to said source and to each of said nozzles, a control valve for each nozzle including an electromagnetic operator for controlling the exhaust of fluid from said reservoir to each of said nozzles, and an electrical circuit for selectively controlling the energization of each of the electromagnetic operators including circuit controller contacts selectively actuated when the switch occupies its normal position and its reverse position, pressure actuated contacts actuated when the pressure within the reservoir falls below a predetermined pressure, and means for energizing one of said electromagnetic operators over the selectively actuated circuit controller contacts when the pressure is above the predetermined pressure to open the selected control valve for exhausting the reservoir fluid between the one point and its adjacent rail, said last means including means for deenergizing the selectively energized electromagnetic operator when the reservoir pressure falls below the predetermined pressure and for maintaining the selected operator energized until the reservoir pressure again reaches the predetermined pressure.

9. A fluid pressure operated blower for a railroad switch comprising at least one nozzle for each switch point directed to deliver a fluid blast between the switch point and the adjacent rail to clear sand, snow or other debris from between the switch point and the rail, a source of fluid pressure, a reservoir connected to said source and to each of said nozzles, a control valve including an electromagnetic operator for each nozzle for controlling the exhaust of fluid from said reservoir to each of said nozzles, and an electrical circuit for controlling the energization of said electromagnetic operator including a first pair of pressure operated contacts adapted to close when the reservoir pressure falls below a first predetermined pressure, a second pair of pressure operated contacts adapted to close when the reservoir pressure falls below a second predetermined pressure lower than said first predetermined pressure, circuit controllercontacts selectively actuated in accordance with the normal and reverse positions of the switch points, and a relay including front and back contacts, one of said electromagnetic operators being energized over the selectively actuated circuit controller contacts and over a back contact of said relay to open the selected control valve when both pairs of pressure operated contacts are open, said relay being energized to open the energizing circuit. of said selected electromagnetic operator upon closure of said second pair of pressure operated contacts and maintained energized over a front contact 8 I of the relay as long as the first pair of pressure actuated contacts remains closed. I

10. A fluid pressure operated blower for a railroad switch comprising at least one nozzle for each switch point directed to deliver a fluid blast between the switch point and the adjacent rail to clear sand, snow or other debris from between the switch point and the rail, a source of fluid pressure, a reservoir connected to said source and to each of said nozzles, means for controlling the charg' ing rate of said reservoir from said source, a control valve including an electromagnetic operator for each nozzle for controlling the exhaust of fluid from said reservoir to each of said nozzles, and an electrical circuit for controlling the energization of said electromagnetic operator including a first pair of pressure operated contacts adapted to close when the reservoir pressure falls below a first predetermined pressure, a second pair of pressure operated contacts adapted to close when the reservoir pressure falls below a second predetermined pressure lower than said first predetermined pressure, circuit controller contacts selectively actuated in accordance with the normal and reverse positions of the switch points, and a relay including front and back contacts, one of said electromagnetic operators being energized over the selectively actuated circuit controller contacts and over a back contact of said relay to open the selected control valve when both pairs of pressure operated contacts are open, said relay being energized to open the energizing circuit of said selected electromagnetic operator upon closure of said second pair of pressure operated contacts and maintained energized over a front contact of the relay as long as the first pair of pressure actuated contacts remains closed.

11. A fluid pressure operated blower for a railroad switch comprising at least one nozzle for each switch point directed to deliver a fluid blast between the switch point and the adjacent rail to clear sand, snow or other debris from between the switch point and the rail, a source of fluid pressure, a reservoir connected to said source and to each of said nozzles, means for controlling the charging rate of said reservoir from said source, a control valve including an electromagnetic operator for each nozzle for controlling the exhaust of fluid from said reservoir to each of said nozzles, and an electrical circuit for controlling the energization of said electromagnetic operator including normally open control contacts, a first pair of pressure operated contacts adapted to close when the reservoir pressure falls below a first predetermined pressure, a second pair of pressure operated contacts adapted to close when the reservoir pressure falls below a second predetermined pressure lower than said first predetermined pressure, circuit controller contacts selectively actuated in accordance with the normal and reverse positions of the switch points, and a relay including front and back contacts, one of said electromagnetic operators being energized over the selectively actuated circuit controller contacts and over a back contact of said relay to open the selected control valve upon closure of the control contacts when both pairs of pressure operated contacts are open, said relay being energized to open the energizing circuit of said selected electromagnetic operator upon closure of said second pair of pressure operated contacts and maintained energized over a front contact of the relay as long as the first pair of pressure actuated contacts remains closed.

References Cited in the file of this patent UNITED STATES PATENTS Hollinger Oct. 14, 1930 Gilmore et al. Jan. 25, 19 55