US1643669A

US1643669A - A cokpobation of

Info

Publication number: US1643669A
Authority: US
Publication date: 1927-09-27
Anticipated expiration: 1944-09-27

Description

sept. 27, 1927. 1,643,669

H. S. LOOMIS RAILWAY BRAKING APPARATUS Filed Deo. 26, 1925 Patented Sept. 27, 1927.

UNITED STATES PATENT OFFICE.

HAROLD S. LOOMIS, 0F WILKINSBURG, PENNSYLVANIA, ASSIGNOR Tt')` THE UNION SWITCH & SIGNAL COMPANY, OF SWISSVALE, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

RAILWAY BRAKING APPARATUS.

Application led December 26, 1925.

My invention relates to railway braking apparatus, and particularly toapparatus of the type comprisingr trackway mechanism adapted to engage a part of a railway vehicle. l

I will describe one form of railway brakinc apparatus embodyingr mv invention. and will then point out the novel features thereof in claim.

The accompanying drawing is a view, partlv diagrammatic. illustratine: one form of railway braking' apparatus embodying my invention. l

Referring to the drawing. the reference characters 4 and 4. designate the two track rails of a stretch of railway track provided with trackway brakingr mechanism. In the torno here shown. this mechanism comprises two braking bars 5 and 6. located on opposite sides of the rail 4 and arranged to en- .Qaae the two sides disposed in parallel relation of a wheel of a. car pas-siner along the track. Two similar brakino hars 5 and 6 are located on opposite sides of the track rail 4.

The brakiner bars 5. 6. 5 and 6. are com trolled bv a fluid pressure motor device desianated bv the reference character As here shown. this motor device comprises a cylinder 1 containing a reciprocable piston 2. This piston carries a plunger 3. which is operatively connected with the hrakinfr hars through the medium'of link work 7. It will a be plain from the drawing. that when the piston 2 is in its left-hand position. the braking hars are in their non-braking positions. When piston 2 is driven to its righthanrl `position in cvlinder 1. however. the braking bars associated with each of the track rails are urged toward the rail so as to engage the sides of the wheels of a railway vehicle. bars 5 and 5* moving toward the right, and hars 6 and 6 moving toward the left.

The reference character B designates a. magnet valvecomprising a valve stem 8 provided with an armature 8*l and a windingr 9. When winding 9 is energized. the left hand end of cylinder 1 is connected with a suitable source of fluid pressure, not shown in the drawing. through pipe 10, valve B. and pipe 13. When winding 9 is de-energized. however, the valve Bis closed, so that the Serial No. 77,751.

supply oit fluid pressure from pipe 10 to cylinder 1 is discontinued. A second valve C comprises a valve stem 8 which is also provided with a winding; 9 and an armature 8a. and is so arranged that when winding` 9 is cle-energized cylinder 1 on the lett-hand side of piston 2 is connected with atmosphere throuefh pipe 14. valve (l and port 11. It, however. winding 9 is enereized. valve stem 8 is drawn downwardly to blank pipe 14 and prevent the escape ot' fluid pressure trom cylinder 1. A, third valve` designated hv the reference character D. controls the supplv of fluid pressure to the richt-hand end ot cvlinder l. lllfhcn this valve is cle-enen .r1-ized. pine 12 communicating with the richthand end ot cylinder 1 is connected with atmosphere throufrh port 11. Wien nndinoq 9 of valve D is cneroizf-id. however valvel stem 8 is moved downwardlv and pipe 12 is disconnected from port 11 and is connected with a source oi duid pressure. not shown in the drawinfr. throue'h pipe 10.

The three valves l?. and l). are controlled by a manually operable circuit controller dcsirrnated hv the reference character K. and bv three automatic circuit nontrollcrs E. F and (l. Referring narticularlv to circuit controller the reference character 16E desifrnates al pressure responsive unit.. such` for example. as a `Bourdon tube. which controls a contact 17E. so that when thc pressure in the Bourdon tube 16E exceeds predetermined amount. the contact 17E will be open. rlhe circuit controllers F and G are constructed in the sance manner as the circuit controller lll. and ch ot the Bourdon tubes 16E. 161 and 16G is connected with the letthand end oi cylinder 1 throucfh a pipe 15. The parts are so proportioned that the circuit controllers F. and G operate at dit* ferent pressures. For purposes ot' explanation. I will assume that all ot' thc circuit controllers F and G are closed at pressures below 25 lbs. per square inch. At all pressures above 25 lbs. per square inch. contact 1'?G is open. at all pressures above 50 lbs. per square inch. contact 1'?F is open. at all pressures above '75 lhs. per square inch. contact 17E is open.

The circuit controller K comprises a pivoted lever 18 and a plurality ot' fixed

contacts

21, 22, 23, 24 and 25 which may be selectively engaged by the lever 18, depending upon its position. rl'he circuit controller l also comprises a contact segment 20, so disposed that When lever 18 engages contact 21 or contact 24, or occupies any position intermediate these tivo contacts, the lever Will also engage the segment' 20. Carried on lever 18 a push button designated by the reference character 19. his push button is normally closed, but is arranged to be opened manually.

lts shoWn in the drawing, all ot the valves B, C and D, are dc-energizcd and the piston 2 is in its lett-hand position, so that the 'I braking bars located in the tracliWav are in their non-brak ng or inetlective positions. .l Will iirst assume that the operator Wishes to make a light brake application. To accomplish this, he moves lever K into engagement With contact 24. ln so doing, the lever 18 also engages segment 20. Push button 19 is closed, so that current tloWs trom a suitable source ot energy, such a battery J, through Wire 26, push button 19, Wire 18a,

` lever 18, segment 20, Wire 2i, Winding 9 .ot

valve C, and Wires 28 and .29 back to battery J. Valve C is therefore closed to blank pipe 14 and prevent the escape ot' tluid pressure trom the lett-ha d end ot' cylinder 1. fit the same time. current tloWs trom battery J,

through Wire 26, bush button 19, Wire 18, lever 18, Contact 2st, Wire 31, Contact 17C ot circuit controller G, Wires 82, 83. 34, and 85, Winding 9 ot valve B, and Wires 86 and 29 back to battery J. Valve B is therefore opened and fluid pressure is supplied to the lett-hand end ot cylinder 1 forcing piston 2 and plunger B carried thereby, to the right, and urging the braking bars into their brake applying positions. lt the track rails l and el are occupied by a railWay vehicle, the braking bars and 6 Will engage the flanges ot the Wheels With a torce Which depends upon the pressure supplied to cylinder 1. T."Vhen this pressure reaches lbs. per square inch, the contact 17G opens, thereby inter'- rupting the circuit just traced tor Winding 9 ot valve B and interrupting the supply of pressure to cylinder 1. It the pressure in cylinder 1 is decreased, as by leakage past the piston 2, to a value beloW 25 lbs. per square inch, contact 17C' immediately closes and restores the pressure to the proper value.

Should the operator Wish to increase the braking torce applied to the braking bars in the track Way to lbs. per square inch, tor example, he moves lever 18 into engagement With contact The lever still engages segment 2O and valve C is therefore still closed. The circuit just traced ifor Winding 9 ot valve B is noW broken, hoW- ever, but a neW circuit is closed from battery il, through Wire 26, contact 19, Wire 18, lever 18, contact 28, Wire 2l, con act 17F oi circuit controller F, Wires 88, 33, 8st and 85, Winding 9 of magnet valve B, and

Wires

36 and 29 back to battery J. The valve B is noW energized over this neW circuit so the fluid pressure is supplied to cylinder 1 until the pressure in the lett-hand end ot the cylinder reaches 50 lbs. per square inch. Contact 17T then opens. The pressure in the lett-hand end of cylinder 1 is thereafter maintained at the proper value, as explained in connection With circuit controller G. In similar tashion, it lever 18 is moved into engagement With contact 22, magnet valve B is energized over contact 17E, so that the `pressure in the lett-hand end ot1 cylinder 1 Will then be maintained at 75 lbs. per square inch. The circuit tor valve B Will then be from battery J., through Wire 26, push button 19, Wire 18a, lever 18, Contact 22, Wire 89, contact 17E, Wires s0, 311, and 35, Winding 9 of valve B, and

Wires

36 and 29 back to battery J. Finally, When lever 18 is moved into engagement With contact 21, current tloWs from battery J, through Wire 26, push button 19, Wire 18, lever 18, contact 21, Wires ll1 and 85, Winding 9 ot' valve B, and Wires 86 and 29, back to battery J'. lt Will therefore be plain that When the lever 18 is in this position, ,the control ot magnet valve B is independent ot the pressure existing in cylinder 1 and that the full amount ot pressure available in pipe 10 Will be admitted to the tluid pressure motor A. to give a maximum braking effect.

I Will noW assume that the lever 18 is in engagement With Contact 21, so that full braking pressure iseXerted by the braking apparatus, and that the opera-toif'Wis'lies to reduce the braking torce to that corresponding to a pressure of 25 lbs. per square inch in the lett-hand end of the cylinder 1. To accomplish this, the 4operator moves lever K into'engagement With contact 24. Valve C is still closed, and valve B is also closed because Contact 17G is noW open. The operator then opens push button 19. As a result, the circuit is opened for magnet valve C. Which valve immediately opens and vents the lett-hand end of cylinder 1 to atmosphere. This operation is continued until the pressure in the lett-hand end of cylinder 1 is someWhatbeloW 25 lbs. per square inch. The push button 19 isv then released, so that the circuit is again closed tor valve C Which valve immediately closes. The pressure in cylinder 1 is noW beloW 25 lbs. per square inch, so that contact 17G is closed and valve B is energized to raise the pressure in the cylinder to 25 lbs. per square inch. The operation of the apparatus for accomplishing a reduction in braking pressure tro-m any higher pressure to any loWer pressure Will he readily understood from the Jforegoing. lt should be particularly pointed out in this connection. hoWever., that Whenever the push button 19 is opened to vent the cylinder to atmosphere through valve C, the circuit for valve B is also opened, no matter what the pressure in the cylindermay be. It follows that only one of valves B and C can be open at any one time so that it is impossible to waste more than one cylinder full of air at one time.

If the operator wishes to restore the bralr ing bars to their ineffective positions` he first moves lever 18 to the position in which it is illustrated in the drawing. All contacts are then open, so that valve B is closed and valve C is open. The left-hand end of cylinder l is therefore connected with atmosphere. The operator next moves lever 18 into en gagement with contact 25. Current then flows from battery J, through wire 26, push button 19, wire 18, lever 18, contact 25, wire 30, winding 9 of valve D and wire 29 back to battery J. Valve stem 8 of valve D therefore moves downwardly and fluid pressure is supplied to the right-hand end of c ylinder 1` Piston 2 is therefore driven to the left and the braking bars are moved to their non-braking positions. With the braio ing' apparatus thus released, the operator returns lever 18 to the position shown in the drawing, thereby de-energizing valve D and restoring' the apparatus to its normal condition.

I do not claim as my invention the combi nation of a plurality of pressure responsive devices subjected to the pressure in the operating cylinder and in turn actuating a plu` rality of circuit controllers for governing the valve which admits fluid pressure to said cylinder, such combination being the invention of John P. Coleman and disclosed and claimed by him in an application for Letters Patent of the United States, filed April 26, 1926, Serial No. 104,566, for railway braking apparatus.

Although I have herein shown and de scribed only one form of railway braking apparatus embodying my invention. it is un- "e-:ffod that various changes and modifica tions may be made therein within the scope of the appended claim without departing from the spirit and scope of my invention.

Having thus described my invention what I claim is:

Railway braking apparatus comprising a braking bar located in the trackway, a fiuid pressure motor for actuating the bar, a first winding for controlling the admission of fluid to the motor, a second winding for controlling the exhaust of fluid from the motor, a source of energy having one terminal conneeted with one terminal of each of said windings, two fixed Contact members connected with the free terminals of said two windings respectively, a manually operable lever movable into engagement with both fixed contacts but not with either fixed contact alone, and manually operable means 'for connecting the free terminal of the source with said lever.

In testimony whereof I aflix my signature.

HAROLD S. LOOMIS.