US1163675A - Brake-operating mechanism. - Google Patents

Description

J. S. McWHlRTER. BRAKE OPERATING MEcHANlsM.

APPLICATION FILED NOV. 7. 1914.

Patented Dec. 14, 1915.

JOHN S. McWI-IIRTER, OF NEW YORK, N. Y.

BRAKE-OPERATING MECHANISM.

Specification of Letters Patent.

Application filed November 7, 1914. I Serial No. 870,777.

To all lwhom t mag/[concern:

Be it known that I, JOHN S. MCVHIRTER, a citizen of the United States, residing in the city, county, 4and Stateof New York, have made a certain new and useful Invention in `Brake-Operatin Mechanism for Streetars and Similar ehicles, of which the following is a specification.

This invention relates to brake operating nliechanism for street cars and similar vehic es.

The object of the invention is to provide a mechanism of the character referred to which is simple in construction, economical to manufacture, and eicient in operation.

A further object is to provide a brake operating mechanism designed to be installed upon the dash or other upright part of the platform of a car or other vehicle, and to occupy a minimum of space thereon.

Other objects of the invention will appear more fully hereinafter.

The invention consists substantially in the construction, combination, location, and relative arrangement of parts, all as will be` more fully hereinafter set forth, as shown in the accompanying drawing, and finally pointed out in the appended claims.

Referring to the accompanying drawing,-Figure l, is a View in front elevation, parts broken out and parts in vertical transverse section, showing a brake mechanism embodying the principles of my invention, and the stand or casing for installing the same. Fig. 2 is a side elevation of the same.

j Fig. 3 is a vertical transverse section of the sprocket sheave over which the operating connection for the brake chain operates. Fig. 4 is a similar view showing a modified arrangement embraced within the spirit and scope of my invention.

In the construction of brake mechanism for cars or similar vehicles, as heretofore employed, it has been a usual practice to locate the maj or part of the brake operating mechanism, including the drum on which thebperating connection to the brake is wound, and its operating gears, underneath the platform or truck of the car, and in many instances it has been found necessary to provide special blockings or fittings to properly secure such mechanism in operative position. Moreover, in such installations it is necessary to provide a vertical shaft to entend upwardly through the platform floor and to a sufiicient height above the platform gresses lengthwise of the drum, as to practi` cally defeat the principal object of dispensing with the vertical shaft arrangement. Again, where ratchet mechanism is employed in connection with the operation of the drum shaft and its gears, it has been a i.

usual practice to employ a retaining pawl which is ordinarily thrown out of engagement with its coperating ratchet by a rod operated by a foot treadle, and which is thrown into locking engagement with the ratchet by gravity. Ordinarily upon release of the ratchet mechanism which holds the drum in rotated position to apply the brakes, the drum revolves rapidly under the rotative tension to which it is subjected when the brakes are applied. It sometimes happens that through carelessness, inadvertence or accident, pressure on the foot treadle which controls the locking pawl is released before the unwinding operation of the drum rammed nec. ii, i915.

is completed, with the result that the locking dog drops by gravity into engaging relation with respect to its cooperating ratchet, and hence the rapidly rotating parts are sud-- denly brought to a stop with a shock which is liable to break the ratchet or the locking pawl, or their associated parts.

It is among'the special purposes of my present invention to avoid the objections noted and to provide a structure of brake operating mechanism which may be installed upon the platform of a car and will occupyv minimum space thereon, and wherein the lockingv dog is released by gravity and consequently falls away from engagement-w1th its coperating ratchet when pressure 1s removed from its operating rod or treadle.

ln carrying out my invention propose to dispense with the usual winding drum on which the brake chain operating cable or other connection heretofore has been wound spirally, and in place thereof to employ simply an idler or sheave around which, in one form of my invention, passes the bight of a looped cable, chain, or other eXible connection, the free ends thereof being connected to the brake operating chain or connection, the latterbeing led and guided in suitablek direction for connection with the brake devices. In another form of embodiment of the broad principles of my/invention, I propose to employ a metal or Y other form of strap which, through suitable connections, is secured at one end to the brake devices, and the other end thereof is passed partially around the sheave or idler and is attached thereto, whereby when the sheave or idler is revolved in one direction, the band or strap winds upon .itself thereon in convolute coils.

-Thus in either of the forms of my invention,

referred to the lengthof the drum or idler is required to be only sufficient to accom- Lmoda-te the transverse dimension of the chain, band strap or other connection to the brake devices since such connection operates in a single vertical plane instead of progressing along the drum as the winding operation progresses, and consequently the apparatus may be installed upon the platform/'of the car in compact form and will occupy minimum space thereon. I also propose to locate the locking pawl or dog for the ratchet mechanism which locks the brake operating devices in applied relation below the coperating ratchet wheel, and to mount saidpawl or dog to drop by gravity away from the ratchet, when released, and to be moved yieldingly into engaging relationV with respect to the ratchet through treadle .operated devices, whereby, whenever the treadle is released, whether through design or .inadvertence, accident or carelessness, the locking dog or pawl will drop be- 'low and out of the path of the teeth of the ratchet.-

In the accompanying drawing I have illustrated different. forms of arrangements which I have found to be practical and which embody the principles o f my invention, and wherein- 5 is an upright casing or stand designed to be installed upon the platform of a car or other vehicle, and preferably against the dash or other vertical part of the platform, and resting on the oor thereof. Upon a horizpntal stud 6, extending between the front and rear plates of the casingnear its upper end-is mounted an idler or sheave 7, formed on 'or secured to the hub of a gear wheel 8, in such manner as to cause the gear wheel and sheave to rotate in unison. In the form of my invention shown in Figs. 1, 2 andI 3, the sheave 7, is formed into a sprocket over which engages the bight of a chain 9, or other suitable connection, which is formed into a loop, the free ends of the connection 9, extending downwardly and both being connected tothe chain or other connection 10, which operates the brake devices, in a manner well understood in the art. Ordinarily the brake device connection 10 is located beneath the carplatform and operates horizontally. In order to facilitate the operation thereof and to afford a fair lead for the same, and reduce friction, I mount a guide roller 111, in suitable brackets 12 depending from the base 13 of the casing. The connection 10` passes around and is guided by this roller 11,. and its end is thereby deflected upwardly for attachment to the ends ofthe connection 9. These ends may be secured together in any convenient manner. A simple arrangement is shown wherein an extended link 14 forms the end of connection 10, and the two ends of the looped chain or connection 9, are secured .to this extended link. It is obvious that many other forms -of connections for the ends of the members 9 and 10 might readily suggest themselves to skilled in the art and still fall within the spirit and scope of my invention as defined in the claims.

Rotary movement may be imparted to the sheave 7 in any Asuitable l or convenient manner. A simple arrangement is shown wherein a shaft 15 is horizontally journaled in the upper end of the casing 5, and eX- tends through the front plate of the casing to receive an operating handle or wheel 16, by which said shaft may be rotated. This shaft in the form shown, is arranged in parallel relationto the aXis of rotation of the sprocket 7 and a pinion 17, thereon meshes with and drives the gear wheel 8, which is connected to the sprocket 7. With this construction it'will be seen that when the operating wheel 16 is rotated in either direction from a central 0r neutral position one or the-other of the ends of the looped connection 9 will be wound upon the sprocket, thereby exerting an upward pull on the connection 10 and hence elfecting an-application of the brake devices.

In place of alooped chain or connection 9, operating over the sheave 7, it is obvious that other constructions and provisions may be employed. For .instancesee Fig. 4, the sprocket wheel 7, may be replaced by a plain sheave 27 around which may be Wound spirally one end of a strap or band 28` of suitable material, said end being secured to the periphery of the sheave as indicated at 29, and the other end of said strap or band secured to the link 14, of chain 10. With this arrangement the advantages and benefits of my invention may be also secured.

persons l It is evident that still other arrangements Ordinarily it is desirable to lock the brake devices in more or less applied-relation, and ratchet and pawl mechanism is employed in practice for this purpose, said mechanism being usually so arranged as to lock the brake operating devices when the operating wheel is turned in one direction only. Pawl and ratchet mechanism is employed for this purpose, a foot treadle and suitable connections being employed to disengage the pawlfrom the ratchet. The disadvantage of this arrangement, as I have already indicated, is that'when the ratchet mechanism is released after operation of the brake applying devices, the drum and handle revolve rapidly toward brake release position, and with con# siderable force, and consequently the pawl must be retained in retracted position.

Sometimes the pawl is inadvertently or carelessly released from displaced position before this rapid rotation ceases thereby permitting the pawl` to drop back into engaging relation with the ratchet too soon, resulting in the pawl being engaged abruptly by a tooth of the ratchet wheel, and causing a severe shock if not destruction of the pawl or ratchet teeth. To avoid this objection and danger I locate the pawl member 18 below the ratchet wheel 19, the latter being carried on the shaft 15. In the form shown, the pawl 18 is a lever which is pivoted at one end upon a stud 20 in the casing at one side of the shaft 15, and extends horizontally from its pivot point, beneath the ratchet wheel 19, withits free end extended to the other side of the shaftfl, the pawl tooth or shoulder 21, being located upon the upper edge of the pawl to coperate with the teeth of the ratchet wheel 19 to form a stop therefor, when said wheel revolves in one direction. To the free end of the pawl 18 is connected a rod 22` upon which is mounted a spirally coiled spring 23, which bears at its upper end against a pin 24, in the rod 22, and at its lower end said spring is seated against the-upper end of a sleeve 25, freely ,into the upper end of which the rod 22 eX- tends. connected to one end of a foot treadle 26, pivotally mounted at the base of the casing. With this construction it will be seen that the pawl 18 is normally held by gravity with its shoulder 21, out of the path of the teeth of the ratchet wheel 19, and with its free end supported by the spring 2 3. however, the treadle 26 is depressed the sleeve 25 is moved endwise upwardly and the upper end thereof Working against the lower end of the spring 23, causes the latter to yieldingly raise the rod l2 and to roclz. the pawl into position to eng-age the ratchet wheel. Should pressure be released upon the treadle the pawl will again drop down out ofv engaging relation with the ratchet as soon as the tension on the tooth of the dog,

The lower end of the sleeve 25 isu When,

struction is that the motorman is enabled to depress the treadle with his foot and keep it depressed while the brake Wheel 16 is being rotated in brake applying direction, the spring support for the locking dog permitting said dog to yield as the teeth of the ratchet pass by it, whereas 1in the case of the rigid rod connection for operating the dog it is necessary to repeatedly work the foot treadle up and down while the brake Wheel is being operated in brake applying direction. a

Having now set forth the objects and nature of my invention, and arrangements embodying the principles thereof, I wish it to be understood that I do not limit or confine myself to the exact and specific details shown and described as variations therefrom and changes therein might readily occurto persons skilled in the art and still fall within the spirit and scope of my invention. But

IVhat I claim as new and useful,l and of my own invention, and desire to secure by Letters Patent is 1. In a brake operating mechanism for lcars or other vehicles, a horizontally acting brake applying connection having an upwardly eitending end, a vertically arranged,

ranged sheave over which said member op- -f erates, said sheave corresponding in length to the transverse width of said member, and vertically operating means for actuating said Sheave.

2. In a brake operating mechanism for cars or other vehicles, a casing vertically arranged on the car platform, a horizontally operating brake applying connection haying a portion extending vertically into S'ald casing, an operating member arranged yvlthin the casing and connected to the vertlcally extending portion of \said brake applymg connection, a horizontally arranged sheaye journaled in said casing upon which sald member operates, said Sheave having a length corresponding to the transverse width of said member, and means operating in a cars or other vehicles, a horizontally operating brake applying connection, a vertically operating chain formed into a loop and having its yends connected to said brake applying connection, a horizontally arranged sprocket over which the bight of said loop engages, and means operatingV inl a vertical plane for actuating said sprocket.

5. In a brake operating mechanism for cars or other vehicles, a horizontally operating brake applying connection having a vertically extending portion, a. chain operating in a single vertical plane and connected to the vertically extending portion of said brake applying connection, a horizontally arranged sprocket over which said chain operates, and means operating in a vertical plane for actuating said sprocket.

6. In a brake operating mechanism for cars or other vehicles, a horizontally operating brake applying connection, a vertically operating member connected at its lower end to said connection and working in a single vertical plane, and means operating in a vertical plane for actuating said member.

7. In a brake operating mechanism for cars or other Vehicles, a brake applying connection, located beneath the vehicle platform, means to direct the end of said connection upwardly above the platform, an operating member connected to said upwardly directed end, said member workingV in a single vertical planev transverse to the actuating means for said member, and means having a horizontal axis for actuating said member. i

8. In a brake operating mechanism for cars or other vehicles, a brake applying connection, located beneath the vehicle platform, a guide also located beneath the vehicle platform around which said connection passes whereby its end is directed vertically above the platform, an operating connection attached to the vertically directed end of the brakeapplying connection, and operating in a single vertical plane transverse to the actuating means for said member, and means operating on a horizontal axis for actuating said member. l

9. In a brake operating mechanism fo cars or other vehicles, a vertically extending casing, afstud transversely mounted in the upper end of the casing, a gear mounted on Asaid stud and having an' attached laterally extending hub, a drive shaft also mounted in said casing and carrying a pinion to mesh with and drive said gear, a connection engaging over said hub and depending vertically therefrom to operate in a single vertical plane, a brake applying A'connection to which the lower end of said chain or other connection is connected, and means for actuating said drive shaft.

:10. In a brake operating mechanism for cars or other vehicles, a vertically extending casing, a stud transversely mounted in the upper end of the casing, a gear. mounted on said stud and having an attached laterally extending hub, a drive shaft also mounted in said casing and carrying'a pinion to mesh with and drive said gear, a connection engaging over said hub and depending vertically therefrom to operate in a single vertical plane, a brake applying connection to which the lower end of said chain or other connection is connected, means to actuate said drive. shaft and a pawl and ratchet mechanism to lock the same.

In testimony whereof I have hereunto set my hand in the presence of thesubscribing witnesses, on this 28th day of October, A. D., 1914.

JOHN s. MCWHIRTER. Witnesses S. E. DARBY, Jr., S. E. DARBY.

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