CA2214756A1 - Hand brake chain and sheave arrangement - Google Patents
Hand brake chain and sheave arrangement Download PDFInfo
- Publication number
- CA2214756A1 CA2214756A1 CA002214756A CA2214756A CA2214756A1 CA 2214756 A1 CA2214756 A1 CA 2214756A1 CA 002214756 A CA002214756 A CA 002214756A CA 2214756 A CA2214756 A CA 2214756A CA 2214756 A1 CA2214756 A1 CA 2214756A1
- Authority
- CA
- Canada
- Prior art keywords
- wheel
- handbrake
- flexible member
- braking mechanism
- operated
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Landscapes
- Braking Arrangements (AREA)
Abstract
The invention enables conventional railroad car handbrakes to be used with railroad cars having increased gross rail loads by providing a chain and sheave arrangement for multiplying the braking force of the conventional railroad car handbrake. The arrangement includes a chain with one end attached to the handbra ke and the other end fixedly attached to the railroad car. A floating sheave wheel is mounted on the chain for movement towards and away from the handbrake, the sheav e wheel being provided with a trolley support from which another chain extend towa rds the braking mechanism. In this manner, the force on the braking mechanism can be doubled.
Description
CA 022147~6 1997-09-0~
FIELD OF T~IE INVENTION
The present invention relates to braking systems. More specifically, the invention relates to a railcar handbrake arrangement for use in conjunction withavailable railcar handbrakes and braking mech~ni.cm.~ in order to increase the braking force applied to the railcar wheels.
BACKGROUND OF THE INVENTION
In addition to air brakes powered from a locomotive, railroad cars or "railcars"are typically provided with a handbrake assembly which is used by the railroad personnel when a railcar is manipulated without being attached to the compressed air source. Certain standards, such as those adopted by the American Association of Railroads ("AAR"), require that the forces compressing shoes of the braking mechanism against the railroad railcar wheels must exceed 10% of the gross rail load of the railcar.
See, for in~t~n~e, AAR Standard No. S-401, published 1993.
For economic reasons, the gross rail loads of railroad cars have seen incr~ases over the years from 220,000 lbs (70 tons) to 263,000 lbs (100 tons) and, more recently, to 286,000 lbs (110 tons) . As the gross rail loads of railcars increase, the forces compressing the brake shoes against the wheels of the railcar must also be made to increase in order to comply with the AAR standard described above.
CA 022147~6 1997-09-0~
Unfortunately, some commercially available handbrake assemblies were not originally developed for use with today's higher gross rail load cars. As such, they cannot be implemented alone, or without modification, so as to provide the n~cess~ry brake shoe force to meet the above described standards. Some handbrake assemblies provide de lir~tçcl multiplying levers, typically using a lever pivotally mounted adjacent the brake shoes, so that the force applied is multiplied by a fixed ratio, e.g. by a factor of seven. Nevertheless, the total force applied by such brake systems may still be insufficient to meet the above standards for railcars having gross rail loads of 100 or 110 tons. However, since these handbrake assemblies are conventional and easily available, it is desirable to provide a handbMke force multiplier which is supplementary to the existing de-lir~ted force multiplying mech~nicmc used in such handbrake assemblies.
Accordingly, the present invention seeks to provide a handbrake arrangement which enables conventional or existing railroad braking mech~nicm.c to be used with railcars having increased gross rail loads.
SUl\IMARY OF THE INVENTION
According to one aspect of the invention, a retro-fittable handbrake system is provided for use with a railroad car having wheels and a wheel-operated handbrake connrctecl via a flexible member to an engagement member of a braking mechanism 20244654. 1 CA 022147~6 1997-09-0~
wherein operation of the wheel-operated handbrake effects and engages the braking mechanism. The retro-fittable system includes a sheave wheel which may be installed such that a portion of the flexible member is wrapped around the sheave wheel in a U-shaped configuration, one end of said flexible member being connected to the wheel-operated handbrake and the other end anchored to the railroad car in order to enable the sheave wheel to float. Means comprising an additional flexible member are provided for conn~-cting the floating sheave wheel and tr~n.cmittin~ a force applied thereto to the braking mechanism engagement member. In this manner, the retro-fittable system can apply a force to the engagement member of the braking mechanism twice as great as the original force provided thereon by the wheel-operated handbrake. This additional force is sufficient to permit the braking mechanism to handle increased gross rail loads in accordance with the applicable AAR standards.
In the prefelled embodiment, the wheel-operated handbrake is a group "O" type handbrake and the braking mechanism is a NYCOPAC II or NYCOPAC IIA braking mechanism m~nllf~hlred by New York Air Brakes of Watertown, New York.
According to another aspect of the invention, a handbrake system is provided for use with a railroad car having wheels. The invention comprises a wheel-operated handbrake mounted to the railroad car. A first flexible member is provided having one end attached to the wheel-operated handbrake and the other end anchored to the 20244654.1 CA 022147~6 1997-09-0~
railroad car. The wheel-operated handbrake is operative to take up the first flexible member and exert a force or tension thereon. A floating sheave wheel is also provided.
A portion of the first flexible member is wrapped around the sheave wheel in a U-shaped configuration such that the sheave wheel is moveable towards and away from the wheel-opel~led handbrake. A braking mechanism is included for applying braking force to the railroad car wheels. The braking mechanism includes a movable engagement member for eng~ging the braking mechanism. A second flexible member and first connection means are provided for connPcting the floating sheave wheel to the second flexible member, so that the second flexible member depends from the floating sheave wheel. A second connection means is provided for connecting the second flexible member to the braking mechanism engagement member. In this manner, the operation of the wheel-operated handbrake effects a braking force.
20244654. 1 CA 022147~6 1997-09-0~
BRIEF DESCRIPTION OF THE DRAVVINGS
For a better underst~ntling of the present invention and to show more clearly how it may be carried into effect, reference will now be made by way of example only to the accompanying drawings, in which:
Fig. 1 is a srhpm~tic diagram of a prior art handbrake assembly employed in conjunction with a known type of railcar braking mech~ni~m;
Fig. 2 is a partial view of the rear of a railroad car showing a handbrake arrangement according to a preferred embodiment of the present invention;
Fig. 3 is a sectional view of the handbrake arrangement, taken along line A-A
in Figure 2;
Fig. 4 is a partial side view of the railroad car showing how the handbrake arrangement of Figs. 2 and 3 is connected to the known railroad car braking mech~ni~m; and Fig. 5 is a detail view of a portion of the railroad car braking mech~ni~m 20244654. 1 CA 022147~6 1997-09-0~
DETAILED DESCRIPIION OF PREFERRED EMBODIMENTS
Fig. 1 shows a prior art railcar handbrake system in schPrn~tir form. The system comprises a conventional vertical wheel handbrake 10 which is fixed to a railcar (not shown in Fig. 1) and which can be manipulated by railroad personnel. A chain 12, which is anchored at one end thereof to the handbrake, connects the handbrake 10 to a known type of braking mechanism 16. A fixed, albeit rotatable, pulley 14 guides the chain 12 for this purposes. The braking mechanism 16 comprises a dedicated force multiplying lever 18 which is pivotally connected at its fulcrum 25 to a brake beam 20. The lever 18 has a long side and a short side, the long side of the lever being attached to the chain 12 and the short side of the lever being attached to the brake beam connection rod 26 via a two pin connection 27. The brake beam 20 carries two (2)brake shoes 22 for application against two railcar wheels 24. The short side of the lever 18 is connPctell via the connPcting rod 26 to a dead lever 28 which is pivotally connPcte~l to the railcar via a dead lever connection rod 30. The dead lever is similarly connecled to a second pa r oi brake shoes 32 via a second brake beam 34. As the chain 12isconnPctecl to the long side of lever 18, the lever multiplies the force or tension, X, applied to it by chain 12 by a ratio of R: 1. However, because the lever 18 is in effect connPcte~i to two (2) braking shoes, the force applied by each brake shoe to its respective railcar wheel is RX/2.
20244654. 1 CA 022147~6 1997-09-0~
With certain prior art handbrake systems, the force RX/2 applied by the braking shoes 22, 32 is insufficient to meet the above mentioned AAR standard which requires that the total handbrake shoe force is at least 10% of the railcar gross load.
For example, the combination of a conventional group UO" handbrake, such as the S model Universal #4493-3 vertical wheel handbrake m~nllfactllred by Universal Railway Devices Co., Chicago, Illinois, when coupled with the well known model NYCOPAC
II or NYCOPAC IIA braking mechanism manufactured by New York Air Brakes of Watertown, New York, cannot produce enough braking force to comply with the AAR
standards for railcars having a gross rail load of 110 tons (286,000 Ibs). This is because the conventional group "O" handbrake can only provide a tension on chain 12 of about 4,500 Ibs, and the NYCOPAC II or NYCOPAC IIA braking mech~ni~m, which employ a dedicated force multiplying lever as described above, only has a seven-fold multiplication factor. This yields a total applied force of only about 7,875 lbs per each of the four (4) brake shoes, which is insufficient to meet the above mentioned AAR
standards for railcars having a gross rail load of 263,000 Ibs (100 tons) or 286,000 Ibs or (110 tons).
Figs. 2-5 show a handbrake system in accordance with the preferred embodiment. The system comprises a plefel,ed handbrake arrangement 40 which is employed in conjullclion with the above described known braking mechanism 16.
Referring to these figures, the preferred handbrake arrangement 40 colllpfises 20244654. 1 CA 022147~6 1997-09-0~
handbrake 10, such as the conventional group uon handbrake described above, which is mounted to the rear end of a rail car 42. A first flexible member, such as chain 44, is conn~cted at one end thereof to a shock retarder 46 which is affixed to the railcar 42 by a mounting bracket 48. The chain 44 exits the handbrake 10 in a vertical plane parallelling the rear face of railcar 42, but instead of being connected directly to the braking mechanism 16, chain 44 passes under a floating sheave wheel 50 in a U-loop configuration and returns to be anchored to the railcar by a shackle 52. Other anchoring means can be employed as well. The floating sheave wheel 50 is provided with a trolley support 51 to which a second chain 54 is connlocted The trolley support has bifurcated arms 53 which are pivotably or rotatably connected to a central axis 55 (or axle) of the sheave wheel thereby enabling the sheave wheel 50 to rotate when the handbrake 10 is operated to take up or release the chain 44. The floating sheavewheel 50 is partially covered by a housing 56 to prevent injury to railroad personnel due to the movement of the sheave wheel.
The direction of the second chain 54 is changed from ~ertical to horizontal by alower sheave wheel 58 which is rotatably mounted under the railcar 42 by a mounting bracket 60. In the horizontal plane (best seen Fig. 4), the second chain 54 is attached to a rod 62 which is conn~cted to the long side of the decli~tecl force multiplying lever 18 associated with the braking mechanism 16. In the preferred embodiment, braking mechanism 16 is a NYCOPAC II or NYCOPAC IIA brake mechanism 20244654. 1 CA 022147~6 1997-09-0~
described above. A detail view of the lever 18 and associated braking shoe 22 is shown in Fig. 5, wherein the released or rest position of the lever is shown in phantom and the engaged or operative position of the lever is shown in solid lines. It will be appreciated, however, that the brake arrangement 40 of the present invention can be used with other types of braking mech~ni~m.c, employing different multiplication ratios.
It will thus be seen from the foregoing that the chain 44 extending from the handbrake 10, instead of being attached directly to the braking mechanism as in the prior art, passes under floating sheave wheel 50 and returns to be anchored to the railcar 42. Another chain extends from the sheave wheel trolley support 51 to the braking mechanism 16. This arrangement thus forms a tackle which multiplies the force or tension applied by the handbrake 10 by a factor of two. Thus, if the conventional "O" type handbrake 10 exerts a force of, for example, 4,500 lbs, the force or tension applied to the longer side of the braking mechanism lever 18 will be about 9,000 lbs. Hence, the force applied by the smaller side of the braking mechanism lever 18 will be a theoretical 63,000 lbs due to the 7:1 multiplication ratio provided by the force multiplying lever 18 of the NYCOPAC II or NYCOPAC IIA brake mechanism.
As the smaller side of the lever 18 is attached to the brake beam connection rod 26, the force comples~ g each brake beam against its respective two wheels, via the two
FIELD OF T~IE INVENTION
The present invention relates to braking systems. More specifically, the invention relates to a railcar handbrake arrangement for use in conjunction withavailable railcar handbrakes and braking mech~ni.cm.~ in order to increase the braking force applied to the railcar wheels.
BACKGROUND OF THE INVENTION
In addition to air brakes powered from a locomotive, railroad cars or "railcars"are typically provided with a handbrake assembly which is used by the railroad personnel when a railcar is manipulated without being attached to the compressed air source. Certain standards, such as those adopted by the American Association of Railroads ("AAR"), require that the forces compressing shoes of the braking mechanism against the railroad railcar wheels must exceed 10% of the gross rail load of the railcar.
See, for in~t~n~e, AAR Standard No. S-401, published 1993.
For economic reasons, the gross rail loads of railroad cars have seen incr~ases over the years from 220,000 lbs (70 tons) to 263,000 lbs (100 tons) and, more recently, to 286,000 lbs (110 tons) . As the gross rail loads of railcars increase, the forces compressing the brake shoes against the wheels of the railcar must also be made to increase in order to comply with the AAR standard described above.
CA 022147~6 1997-09-0~
Unfortunately, some commercially available handbrake assemblies were not originally developed for use with today's higher gross rail load cars. As such, they cannot be implemented alone, or without modification, so as to provide the n~cess~ry brake shoe force to meet the above described standards. Some handbrake assemblies provide de lir~tçcl multiplying levers, typically using a lever pivotally mounted adjacent the brake shoes, so that the force applied is multiplied by a fixed ratio, e.g. by a factor of seven. Nevertheless, the total force applied by such brake systems may still be insufficient to meet the above standards for railcars having gross rail loads of 100 or 110 tons. However, since these handbrake assemblies are conventional and easily available, it is desirable to provide a handbMke force multiplier which is supplementary to the existing de-lir~ted force multiplying mech~nicmc used in such handbrake assemblies.
Accordingly, the present invention seeks to provide a handbrake arrangement which enables conventional or existing railroad braking mech~nicm.c to be used with railcars having increased gross rail loads.
SUl\IMARY OF THE INVENTION
According to one aspect of the invention, a retro-fittable handbrake system is provided for use with a railroad car having wheels and a wheel-operated handbrake connrctecl via a flexible member to an engagement member of a braking mechanism 20244654. 1 CA 022147~6 1997-09-0~
wherein operation of the wheel-operated handbrake effects and engages the braking mechanism. The retro-fittable system includes a sheave wheel which may be installed such that a portion of the flexible member is wrapped around the sheave wheel in a U-shaped configuration, one end of said flexible member being connected to the wheel-operated handbrake and the other end anchored to the railroad car in order to enable the sheave wheel to float. Means comprising an additional flexible member are provided for conn~-cting the floating sheave wheel and tr~n.cmittin~ a force applied thereto to the braking mechanism engagement member. In this manner, the retro-fittable system can apply a force to the engagement member of the braking mechanism twice as great as the original force provided thereon by the wheel-operated handbrake. This additional force is sufficient to permit the braking mechanism to handle increased gross rail loads in accordance with the applicable AAR standards.
In the prefelled embodiment, the wheel-operated handbrake is a group "O" type handbrake and the braking mechanism is a NYCOPAC II or NYCOPAC IIA braking mechanism m~nllf~hlred by New York Air Brakes of Watertown, New York.
According to another aspect of the invention, a handbrake system is provided for use with a railroad car having wheels. The invention comprises a wheel-operated handbrake mounted to the railroad car. A first flexible member is provided having one end attached to the wheel-operated handbrake and the other end anchored to the 20244654.1 CA 022147~6 1997-09-0~
railroad car. The wheel-operated handbrake is operative to take up the first flexible member and exert a force or tension thereon. A floating sheave wheel is also provided.
A portion of the first flexible member is wrapped around the sheave wheel in a U-shaped configuration such that the sheave wheel is moveable towards and away from the wheel-opel~led handbrake. A braking mechanism is included for applying braking force to the railroad car wheels. The braking mechanism includes a movable engagement member for eng~ging the braking mechanism. A second flexible member and first connection means are provided for connPcting the floating sheave wheel to the second flexible member, so that the second flexible member depends from the floating sheave wheel. A second connection means is provided for connecting the second flexible member to the braking mechanism engagement member. In this manner, the operation of the wheel-operated handbrake effects a braking force.
20244654. 1 CA 022147~6 1997-09-0~
BRIEF DESCRIPTION OF THE DRAVVINGS
For a better underst~ntling of the present invention and to show more clearly how it may be carried into effect, reference will now be made by way of example only to the accompanying drawings, in which:
Fig. 1 is a srhpm~tic diagram of a prior art handbrake assembly employed in conjunction with a known type of railcar braking mech~ni~m;
Fig. 2 is a partial view of the rear of a railroad car showing a handbrake arrangement according to a preferred embodiment of the present invention;
Fig. 3 is a sectional view of the handbrake arrangement, taken along line A-A
in Figure 2;
Fig. 4 is a partial side view of the railroad car showing how the handbrake arrangement of Figs. 2 and 3 is connected to the known railroad car braking mech~ni~m; and Fig. 5 is a detail view of a portion of the railroad car braking mech~ni~m 20244654. 1 CA 022147~6 1997-09-0~
DETAILED DESCRIPIION OF PREFERRED EMBODIMENTS
Fig. 1 shows a prior art railcar handbrake system in schPrn~tir form. The system comprises a conventional vertical wheel handbrake 10 which is fixed to a railcar (not shown in Fig. 1) and which can be manipulated by railroad personnel. A chain 12, which is anchored at one end thereof to the handbrake, connects the handbrake 10 to a known type of braking mechanism 16. A fixed, albeit rotatable, pulley 14 guides the chain 12 for this purposes. The braking mechanism 16 comprises a dedicated force multiplying lever 18 which is pivotally connected at its fulcrum 25 to a brake beam 20. The lever 18 has a long side and a short side, the long side of the lever being attached to the chain 12 and the short side of the lever being attached to the brake beam connection rod 26 via a two pin connection 27. The brake beam 20 carries two (2)brake shoes 22 for application against two railcar wheels 24. The short side of the lever 18 is connPctell via the connPcting rod 26 to a dead lever 28 which is pivotally connPcte~l to the railcar via a dead lever connection rod 30. The dead lever is similarly connecled to a second pa r oi brake shoes 32 via a second brake beam 34. As the chain 12isconnPctecl to the long side of lever 18, the lever multiplies the force or tension, X, applied to it by chain 12 by a ratio of R: 1. However, because the lever 18 is in effect connPcte~i to two (2) braking shoes, the force applied by each brake shoe to its respective railcar wheel is RX/2.
20244654. 1 CA 022147~6 1997-09-0~
With certain prior art handbrake systems, the force RX/2 applied by the braking shoes 22, 32 is insufficient to meet the above mentioned AAR standard which requires that the total handbrake shoe force is at least 10% of the railcar gross load.
For example, the combination of a conventional group UO" handbrake, such as the S model Universal #4493-3 vertical wheel handbrake m~nllfactllred by Universal Railway Devices Co., Chicago, Illinois, when coupled with the well known model NYCOPAC
II or NYCOPAC IIA braking mechanism manufactured by New York Air Brakes of Watertown, New York, cannot produce enough braking force to comply with the AAR
standards for railcars having a gross rail load of 110 tons (286,000 Ibs). This is because the conventional group "O" handbrake can only provide a tension on chain 12 of about 4,500 Ibs, and the NYCOPAC II or NYCOPAC IIA braking mech~ni~m, which employ a dedicated force multiplying lever as described above, only has a seven-fold multiplication factor. This yields a total applied force of only about 7,875 lbs per each of the four (4) brake shoes, which is insufficient to meet the above mentioned AAR
standards for railcars having a gross rail load of 263,000 Ibs (100 tons) or 286,000 Ibs or (110 tons).
Figs. 2-5 show a handbrake system in accordance with the preferred embodiment. The system comprises a plefel,ed handbrake arrangement 40 which is employed in conjullclion with the above described known braking mechanism 16.
Referring to these figures, the preferred handbrake arrangement 40 colllpfises 20244654. 1 CA 022147~6 1997-09-0~
handbrake 10, such as the conventional group uon handbrake described above, which is mounted to the rear end of a rail car 42. A first flexible member, such as chain 44, is conn~cted at one end thereof to a shock retarder 46 which is affixed to the railcar 42 by a mounting bracket 48. The chain 44 exits the handbrake 10 in a vertical plane parallelling the rear face of railcar 42, but instead of being connected directly to the braking mechanism 16, chain 44 passes under a floating sheave wheel 50 in a U-loop configuration and returns to be anchored to the railcar by a shackle 52. Other anchoring means can be employed as well. The floating sheave wheel 50 is provided with a trolley support 51 to which a second chain 54 is connlocted The trolley support has bifurcated arms 53 which are pivotably or rotatably connected to a central axis 55 (or axle) of the sheave wheel thereby enabling the sheave wheel 50 to rotate when the handbrake 10 is operated to take up or release the chain 44. The floating sheavewheel 50 is partially covered by a housing 56 to prevent injury to railroad personnel due to the movement of the sheave wheel.
The direction of the second chain 54 is changed from ~ertical to horizontal by alower sheave wheel 58 which is rotatably mounted under the railcar 42 by a mounting bracket 60. In the horizontal plane (best seen Fig. 4), the second chain 54 is attached to a rod 62 which is conn~cted to the long side of the decli~tecl force multiplying lever 18 associated with the braking mechanism 16. In the preferred embodiment, braking mechanism 16 is a NYCOPAC II or NYCOPAC IIA brake mechanism 20244654. 1 CA 022147~6 1997-09-0~
described above. A detail view of the lever 18 and associated braking shoe 22 is shown in Fig. 5, wherein the released or rest position of the lever is shown in phantom and the engaged or operative position of the lever is shown in solid lines. It will be appreciated, however, that the brake arrangement 40 of the present invention can be used with other types of braking mech~ni~m.c, employing different multiplication ratios.
It will thus be seen from the foregoing that the chain 44 extending from the handbrake 10, instead of being attached directly to the braking mechanism as in the prior art, passes under floating sheave wheel 50 and returns to be anchored to the railcar 42. Another chain extends from the sheave wheel trolley support 51 to the braking mechanism 16. This arrangement thus forms a tackle which multiplies the force or tension applied by the handbrake 10 by a factor of two. Thus, if the conventional "O" type handbrake 10 exerts a force of, for example, 4,500 lbs, the force or tension applied to the longer side of the braking mechanism lever 18 will be about 9,000 lbs. Hence, the force applied by the smaller side of the braking mechanism lever 18 will be a theoretical 63,000 lbs due to the 7:1 multiplication ratio provided by the force multiplying lever 18 of the NYCOPAC II or NYCOPAC IIA brake mechanism.
As the smaller side of the lever 18 is attached to the brake beam connection rod 26, the force comples~ g each brake beam against its respective two wheels, via the two
(2) brake shoes, will be a theoretical 31,500 lbs. This force, when the actual efficiency is take into account, is above 10% of the gross rail load of a 110 ton or 286,000 lb.
20244654. 1 - CA 022147~6 1997-09-0~
freight car and thus within the above described AAR specification. In this manner the invention enables conventional or existing railroad braking systems designed for lower gross load rated railcars to be used with railcars having increased gross rail loads and still comply with the applicable AAR standard. Moreover, it will be appreciated that S the force multiplying tackle featured in the invention can be relatively easily retrofitted to existing railcars having the group "O" type handbrake and a braking mechanismsimilar to the NYCOPAC II or NYCOPAC IIA brakes.
Although the handbrake arrangement 40 comprising a single floating sheave wheel represents a preferred embodiment of the invention, persons skilled in the art will appreciate that an arrangement employing a plurality of floating sheave wheels will also fall within the scope of the present invention. While a single sheave wheelprovides a multiplication factor of 2, a plurality of sheave wheels will provide a multiplication factor of 3, 4, etc., depending on the number of sheave wheels employed. There is, however, an issue to be considered in determining the actuallayout of the handbrake arrangement; namely the m~ximnm amount of travel that the handbrake 10 can impart to the first chain 44, that is, the maximum amount of handbrake "pickup" .
The handbrake pickup replese~ a tlist~nre between the fully released and fully engaged positions of the free end of the longer side of the braking mechanism lever 18.
20244654. 1 - CA 022147~6 1997-09-0~
The handbrake pickup depends on the type of braking mechanism. NYCOPAC II and IIA brakes, for example, have a pickup of approximately 15 inches. Conventionally, therefore, in order to bring the braking mechanism into a fully engaged position, the handbrake wheel has to be turned until 15 inches of chain are taken up. With a single sheave wheel according to the preferred embodiment (providing a force multiplication factor 2), the handbrake has to take up 30 inches of chain, with a multiplication factor of 4, it would have to take up 60 inches, etc., which poses a practical limit to the number of sheave wheels that can be used.
This description is made with reference to the pre&rred embodiment of the invention. However, a person skilled in the art will be aware of numerous modifications and variations that can be made without departing from the spirit and scope of the present invention as defined in the appended claims.
20244654. 1
20244654. 1 - CA 022147~6 1997-09-0~
freight car and thus within the above described AAR specification. In this manner the invention enables conventional or existing railroad braking systems designed for lower gross load rated railcars to be used with railcars having increased gross rail loads and still comply with the applicable AAR standard. Moreover, it will be appreciated that S the force multiplying tackle featured in the invention can be relatively easily retrofitted to existing railcars having the group "O" type handbrake and a braking mechanismsimilar to the NYCOPAC II or NYCOPAC IIA brakes.
Although the handbrake arrangement 40 comprising a single floating sheave wheel represents a preferred embodiment of the invention, persons skilled in the art will appreciate that an arrangement employing a plurality of floating sheave wheels will also fall within the scope of the present invention. While a single sheave wheelprovides a multiplication factor of 2, a plurality of sheave wheels will provide a multiplication factor of 3, 4, etc., depending on the number of sheave wheels employed. There is, however, an issue to be considered in determining the actuallayout of the handbrake arrangement; namely the m~ximnm amount of travel that the handbrake 10 can impart to the first chain 44, that is, the maximum amount of handbrake "pickup" .
The handbrake pickup replese~ a tlist~nre between the fully released and fully engaged positions of the free end of the longer side of the braking mechanism lever 18.
20244654. 1 - CA 022147~6 1997-09-0~
The handbrake pickup depends on the type of braking mechanism. NYCOPAC II and IIA brakes, for example, have a pickup of approximately 15 inches. Conventionally, therefore, in order to bring the braking mechanism into a fully engaged position, the handbrake wheel has to be turned until 15 inches of chain are taken up. With a single sheave wheel according to the preferred embodiment (providing a force multiplication factor 2), the handbrake has to take up 30 inches of chain, with a multiplication factor of 4, it would have to take up 60 inches, etc., which poses a practical limit to the number of sheave wheels that can be used.
This description is made with reference to the pre&rred embodiment of the invention. However, a person skilled in the art will be aware of numerous modifications and variations that can be made without departing from the spirit and scope of the present invention as defined in the appended claims.
20244654. 1
Claims (4)
1. A handbrake system for use with a railroad car having wheels, comprising:
a wheel-operated handbrake mounted to the railroad car;
a first flexible member with one end attached to the wheel-operated handbrake and the other end anchored to the railroad car, wherein the wheel-operated handbrake is operative to take up the first flexible member and exert a force or tension thereon;
a floating sheave wheel, wherein a portion of the first flexible member is wrapped around the sheave wheel in a U-shaped configuration such that the sheave wheel is moveable towards and away from the wheel-operated handbrake;
a braking mechanism for applying braking force to the railroad car wheels, wherein the braking mechanism includes a movable engagement member for engaging the braking mechanism;
a second flexible member and first connection means for connecting the floating sheave wheel to the second flexible member, so that the second flexible member depends from the floating sheave wheel; and second connection means for connecting the second flexible member to the braking mechanism engagement member, whereby operation of the wheel-operated handbrake effects a braking force.
a wheel-operated handbrake mounted to the railroad car;
a first flexible member with one end attached to the wheel-operated handbrake and the other end anchored to the railroad car, wherein the wheel-operated handbrake is operative to take up the first flexible member and exert a force or tension thereon;
a floating sheave wheel, wherein a portion of the first flexible member is wrapped around the sheave wheel in a U-shaped configuration such that the sheave wheel is moveable towards and away from the wheel-operated handbrake;
a braking mechanism for applying braking force to the railroad car wheels, wherein the braking mechanism includes a movable engagement member for engaging the braking mechanism;
a second flexible member and first connection means for connecting the floating sheave wheel to the second flexible member, so that the second flexible member depends from the floating sheave wheel; and second connection means for connecting the second flexible member to the braking mechanism engagement member, whereby operation of the wheel-operated handbrake effects a braking force.
2. The handbrake mechanism according to claim 1 wherein the first connection means comprises a trolley support having an end portion which is rigidly fixed to the second flexible member and an opposed end portion rotatably connected to a central axis of the sheave wheel thereby allowing the sheave wheel to rotate when the wheel-operated handbrake is operated to take up or release the first flexible member.
3. A retro-fittable handbrake system for use with a railroad car having wheels and a wheel-operated handbrake connected via a flexible member to an engagement member of a braking mechanism wherein operation of the wheel-operated handbrake engages the braking mechanism, the retro-fittable system comprising:
a sheave wheel, the sheave wheel for installation such that a portion of said flexible member is wrapped around the sheave wheel in a U-shaped configuration, one end of said flexible member being connected to said wheel-operated handbrake and the other end anchored to said railroad car in order to enable the sheave wheel to float; and means comprising an additional flexible member for connecting the floating sheave wheel and transmitting a force applied thereto to said braking mechanism engagement member.
a sheave wheel, the sheave wheel for installation such that a portion of said flexible member is wrapped around the sheave wheel in a U-shaped configuration, one end of said flexible member being connected to said wheel-operated handbrake and the other end anchored to said railroad car in order to enable the sheave wheel to float; and means comprising an additional flexible member for connecting the floating sheave wheel and transmitting a force applied thereto to said braking mechanism engagement member.
4. The retro-fittable handbrake system according to claim 3, wherein the wheel-operated handbrake is a group "O" type handbrake and the braking mechanism is a NYCOPAC II or NYCOPAC IIA braking mechanism.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US90856597A | 1997-08-08 | 1997-08-08 | |
| US08/908,565 | 1997-08-08 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2214756A1 true CA2214756A1 (en) | 1999-02-08 |
Family
ID=25425982
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002214756A Abandoned CA2214756A1 (en) | 1997-08-08 | 1997-09-05 | Hand brake chain and sheave arrangement |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2214756A1 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102501882A (en) * | 2011-11-29 | 2012-06-20 | 太原轨道交通装备有限责任公司 | Anti-shedding device for manual brake chain of railway wagon |
| CN102501881A (en) * | 2011-11-29 | 2012-06-20 | 太原轨道交通装备有限责任公司 | Manual braking pull rod device for driving pulleys of rail wagon |
-
1997
- 1997-09-05 CA CA002214756A patent/CA2214756A1/en not_active Abandoned
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102501882A (en) * | 2011-11-29 | 2012-06-20 | 太原轨道交通装备有限责任公司 | Anti-shedding device for manual brake chain of railway wagon |
| CN102501881A (en) * | 2011-11-29 | 2012-06-20 | 太原轨道交通装备有限责任公司 | Manual braking pull rod device for driving pulleys of rail wagon |
| CN102501882B (en) * | 2011-11-29 | 2015-04-22 | 太原轨道交通装备有限责任公司 | Anti-shedding device for manual brake chain of railway wagon |
| CN102501881B (en) * | 2011-11-29 | 2015-04-22 | 太原轨道交通装备有限责任公司 | Manual braking pull rod device for driving pulleys of rail wagon |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5738416A (en) | Railway braking apparatus to effect a change in a handbrake | |
| CA2523816C (en) | Simplified truck mounted brake system | |
| JP2001270433A (en) | Spring-applied parking brake assembly having manual quick release mechanism | |
| US3731766A (en) | Brake rigging for railway car trucks | |
| US6241057B1 (en) | Hydraulic parking brake lever arrangement for a railroad vehicle braking system | |
| US4312428A (en) | Truck mounted brake apparatus | |
| EP1827944A1 (en) | Disk brake arranged tmx | |
| CA2122883C (en) | Truck mounted brake apparatus | |
| CA1166976A (en) | Low noise railroad retarder brake shoe structure | |
| US4905795A (en) | Handbrake operating linkage for multi-unit rail cars | |
| CA2214756A1 (en) | Hand brake chain and sheave arrangement | |
| US4805743A (en) | Handbrake operating linkage for multi-unit rail cars | |
| US5279395A (en) | Railway car brake system | |
| EP0183299B1 (en) | A parking brake arrangement for a rail vehicle brake unit | |
| US4049088A (en) | Parking brake arrangement for a rail vehicle brake | |
| RU202158U1 (en) | RAIL VEHICLE PARKING BRAKE | |
| US4489814A (en) | Hand brake arrangement | |
| US2169751A (en) | Brake rigging | |
| US2657766A (en) | Brake rigging | |
| US3716119A (en) | Brake mechanisms | |
| US1559503A (en) | Truck brake | |
| CA1163931A (en) | Truck mounted brake apparatus | |
| RU2086446C1 (en) | Mechanical part of railway freight car brake | |
| US787643A (en) | Car-brake. | |
| RU2106272C1 (en) | Railway car brake rigging |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Dead |