CHANGING LENGTH OF A RAILROAD SLACK ADJUSTER

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is related to and claims priority from U.S. Provisional Patent Application Serial No. 61/443,432 filed on February 16, 2011. This application is also closely related to Regular U.S. Utility Patent No. 4,662,485 issued to Kanjo et al. on May 5, 1987 and whose teachings are incorporated into this document by reference thereto.

FIELD OF THE INVENTION

The present invention relates, in general, to slack adjusters for railcar brake rigging and, more particularly, this invention relates to device and method for manually changing length of a railcar slack adjuster without unpinning or removal thereof from the brake rigging.

BACKGROUND OF THE INVENTION

As is generally well known, slack adjuster are utilized extensively on brake riggings for railcars in order to apply and equalize forces onto each brake shoe. Prior to the conception and development of the instant invention, a common method to manually elongate or shorten many slack adjusters, in order to change brake shoes, required the step of unpinning one of the jaw from its connection with the brake rigging due to its rotation, the step of inserting an elongated rod/pry bar through the jaw and the step of rotating the jaw by way of such elongated rod/pry bar. Another method was to use rod/pry bar so as to push the brake shoe assembly away from the wheel. There are potential safety issue with changing the brake shoes by these method as the twisting of the internal springs may potentially result in undesirable instant take-up of the slack adjuster.

Therefore, there is a need for an improved device and method to manually change length of a railcar slack adjuster without unpinning or removal thereof from the railcar brake rigging.

SUMMARY OF THE INVENTION

The invention provides a device disposed between one end of a railcar slack adjuster and a member connecting such one end to the railcar brake rigging. The device is configured to allow manual change of a relative longitudinal position between the housing member and the elongated rod member without unpinning or removing the slack adjuster from the railcar brake rigging. The device includes a first member having one end thereof in at least semipermanently secured connection with an end of the slack adjuster disposed adjacent one of the first and second pivotal connections to the brake rigging. A second member is provided and has one end thereof disposed adjacent to and is spaced apart from an axially opposite end of the first member, the second member having an axially opposite end thereof in at least semi-permanently secured connection with the one of the first and second pivotal connections. There is also a third member being so sized and shaped that the one end of the second member is mounted at least for a rotational movement therewithin and that the axially opposite end of the second member extends beyond an end surface of the third member. A first plurality of ratchet teeth is provided on the second member and a second plurality of ratchet teeth is provided in the third member in operative alignment with the first plurality of ratchet teeth. A bias member is axially disposed in a space between the axially opposite end of the first member and the one end of the second member.

The invention also provides a method for enabling replacement of at least one brake shoe on a railcar brake rigging including a slack adjuster. The method includes the step of providing a device having a ratchet arrangement disposed therewithin. Then, installing the device between one end of the slack adjuster and a connection of the slack adjuster to the railcar brake rigging. Applying manual rotational force to a portion of the slack adjuster. Then, changing longitudinal position of an elongated rod member of the slack adjuster relative to a housing member thereof aided by the ratchet arrangement.

OBJECTS OF THE INVENTION

It is, therefore, one of the primary objects of the instant invention to provide a slack adjuster for railcar brake rigging.

Another object of the present invention is to provide a device for manually changing length of a railcar slack adjuster without unpinning or removal thereof from the brake rigging.

Yet another object of the present invention is to provide a device for changing length of a railcar slack adjuster without unpinning or removal thereof from the brake rigging that uses a ratchet assembly mounted adjacent and attached to a standard jaw of the slack adjuster.

A further object of the present invention is to provide a device for changing length of a railcar slack adjuster without unpinning or removal thereof from the railcar brake rigging that uses a ratchet assembly mounted within a housing of the slack adjuster.

Yet a further object of the present invention is to provide a method for changing length of a railcar slack adjuster without unpinning or removal thereof from the brake rigging. Yet another further object of the present invention is to provide a method for replacing brake shoes on a brake rigging without unpinning or removal of the railcar slack adjuster without therefrom.

In addition to the several objects and advantages of the present invention which have been described with some degree of specificity above, various other objects and advantages of the invention will become more readily apparent to those persons who are skilled in the relevant art, particularly, when such description is taken in conjunction with the attached drawing Figures and with the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates a perspective view a slack adjuster employing a device of the instant invention for manually elongating or shortening railcar slack adjuster without unpinning or removal thereof from the railcar brake rigging;

FIG. 2 illustrates a partial cross-sectional view of the slack adjuster of FIG. 1 ;

FIG. 3 illustrates a partial cross-sectional view of the device of FIG. 1 ;

FIG. 4 illustrates a perspective view of the device of FIGS. 1-3;

FIG. 5 illustrates a perspective view of one member employed within the device of FIGS. 1-3;

FIG. 6 illustrates a perspective view of another member employed within the device of FIGS. 1-3;

FIG. 7, labeled as prior art, illustrates a partial cross-sectional longitudinal view of a prior art double-acting tension type railcar slack adjuster;

FIG. 8 is a partial enlarged view of the railcar slack adjuster of FIG. 7;

FIG. 9 illustrates a partial cross-sectional view of the slack adjuster employing another device of the instant invention for manually changing length of the railcar slack adjuster without unpinning or removal thereof from the railcar brake rigging; and

FIG. 10, labeled as prior art, illustrates a partial cross-sectional longitudinal view of a prior art double-acting compression type railcar slack adjuster.

BRIEF DESCRIPTION OF THE VARIOUS EMBODIMENTS OF THE INVENTION

Prior to proceeding to the more detailed description of the present invention, it should be noted that, for the sake of clarity and understanding, identical components which have identical functions have been identified with identical reference numerals throughout the several views illustrated in the drawing figures. The instant invention describes a device and method for device for manually elongating or shortening railcar slack adjuster 10 without unpinning or removal thereof from the railcar brake rigging.

The instant invention is illustrated and described in combination with a slack adjuster 10 of a rotary double-acting tension type, as manufactured by the assignee of the instant invention under 2300, shown in FIGS. 7-8. Selected structure and operation principles as related to the cone nut and friction services of such slack adjuster are taught in Regular U.S. Utility Patent No. 4,662,485 issued to Kanjo et al. on May 5, 1987 and owned and by the assignee of the instant invention. Teachings of the U.S. Pat. No. 4,662,485 are incoiporated into this document by reference thereto. However, it will be apparent to those skilled in the relevant art that the instant invention may be applied to other slack adjusters and, as such, should not be interpreted as a limiting factor of the instant invention.

For the sake of brevity, with a portion of the slack adjuster is illustrated in FIG. 10, the detail description of such prior art slack adjuster 10 is omitted in this document. Essentially, the slack adjuster 10 includes an elongated hollow cylindrical housing member 12 which is provided in three housing portions 76, 78 and 80. The housing member 12 has a first pivotal connection 140 at a first end thereof to the railway vehicle brake rigging (not shown) and an elongated rod member 20, which has a second pivotal connection 142 at a first end thereof to the railcar brake rigging (not shown). As best shown in FIG. 1, the first pivotal connection 140 is disposed adjacent the trigger mechanism 148 and essentially is as part of the housing member 12. The rod member 20 has a thread 30 provided on at least a portion of the exterior surface thereof. The threaded portion of the rod member 20 extends into the housing member 12 through a second end thereof. A nut 34 is mounted within the housing member 12 for a linear translation movement on the outer threaded portion of the elongated rod 20. A rod guide 12a is also provided and has on end thereof extending into the housing member 20 and being disposed adjacent the nut 34 in at least an alignment with trigger pin 12c. The axially opposite end of the rod guide 12 has an external thread 12b for use with the internal thread of the first pivotal connection 140. Each of the first and second pivotal connections, 140 and 142 respectively, is illustrated as a convention bifurcated jaw but may be provided by any other conventional attaching members.

In reference to FIGS. 1-6, the instant invention provides a device, generally designated as 150, which is disposed adjacent one of the first and second pivotal connections, 140 and 142 respectively, and is being configured to allow manual change of relative longitudinal position between the housing member 12 and the elongated rod member 20 without unpinning or removing the slack adjuster 10 from the railcar brake rigging (not shown).

More specifically, in the presently preferred embodiment of the invention, the device 150 is disposed between the end of the housing member 12 and the first pivotal connection 140.

Further, the ratchet assembly 150 includes a first member or a cap, generally designated as 160, having one end thereof in at least semi-permanently secured connection with an end of the rod guide member 12a, a second member or ratchet shaft, generally designated as 190, having one end thereof disposed adjacent to and is spaced apart from an axially opposite end of the first member 160, the second member 190 having an axially opposite end thereof in at least semi-permanently secured connection with the second pivotal connection, a third member or a ratchet housing, generally designated as 220, being so sized and shaped that the one end of the second member 190 is mounted at least for a rotational movement therewithin and that the axially opposite end of the second member 190 extends beyond an end surface of the third member 220, a first plurality of ratchet teeth 208 provided on the second member 190, a second plurality of ratchet teeth 250 provided in the third member 220 in operative alignment with the first plurality of ratchet teeth 208, and a bias member 260 axially disposed in a space between the axially opposite end of the first member 160 and the one end of the second member 190.

In accordance with a more detailed description, the first member 160, best shown in

FIGS. 2 and 4, includes a peripheral surface 162 thereof having a substantially round cross- section in a plane being generally transverse to a longitudinal axis 152 of the device 150. Preferably, the substantially round cross-section is being substantially constant tliroughout length of the first member 160. It must be noted that longitudinal 152 of the device 150 also defines the longitudinal axis of the slack adjuster 10. There is also a pair of ends, 164 and 166, terminating length of the first member 160 and being spaced apart from each other along the longitudinal axis 152 of the device 150. Each of the pair of ends 164, 166, has a generally planar surface disposed generally transverse to the longitudinal axis 152. An optional peripheral flange 168 is disposed on one of the pair of ends, referenced with numeral 164. The optional peripheral flange 168 has an exterior generally planar surface 170 essentially defining the surface of the end 164. A cavity 174 is disposed axially within the first member 160 in open communication with the end 164. A first internal thread 178 is provided on a portion of a peripheral surface 176 of the cavity 174. The first internal thread 178 has one end thereof disposed at least in close proximity to the generally planar surface 170 of the end 164. The first internal thread 178 is sized to threadably engage the external thread 12b of the rod guide member 12a in at least a semi-permanent secured connection. There is also a first external thread 180 that is provided on the peripheral surface 162 of the first member 160 in close proximity to another one of the pair of ends, referenced with numeral 166. Another optional element of the first member 160 is a first spring seat 182 depending and extending axially from the end 166. The spring seat 182 has a generally round cross-section in the plane being generally transverse to the longitudinal axis 152 of the device 150.

The second member 190, best shown in FIGS. 3-5, is provided as a substantially solid unitary one-piece member. The second member 190 includes a first portion 192 defining a first end 194 of the second member 190 having a generally planar end surface 196 disposed generally transverse to the longitudinal axis 152. An optional axial cavity 198 is disposed in open communication with the first end 194 of the second member 190 and defines a second spring seat. The second end of the first portion 192 is defined by a first frustoconical peripheral surface portion 200 depending on and terminating the substantially cylindrical peripheral surface 202 of the first portion 190. A first ledge 204 terminates the first frustoconical peripheral surface portion 200 and is being disposed in a plane being generally transverse to the longitudinal axis 152. A ratchet ring is disposed on the first ledge 204 and has a first plurality of ratchet teeth 208 disposed in a circular pattern concentric with the longitudinal axis 152. Each of the first plurality of ratchet teeth 208 has a first surface 210 disposed generally transverse to the longitudinal axis 152 and a second surface 212 disposed at an angle relative to the first surface 210.

The second portion 214 has a proximal end 216 thereof disposed on the first ledge 204 within the ratchet teeth 208 and a distal end 218 thereof carrying a second end of the second member 190. The second portion 214 further defines a substantially cylindrical smooth surface portion 218 and a second external thread 220 provided on a peripheral surface of the second portion 214 adjacent to and spaced from the distal end 217 of the second portion 214. The second external thread 220 is sized to mate with the internal thread of the conventional bifurcated jaw 140 in at least a semi-permanent secured connection.

The generally hollow third member or the ratchet housing 220, best shown in FIGS. 3-4 and 6, has a generally open first end 222 and an axially opposite generally closed second end 224. The second end 224 defines an exterior surface 226 and an interior surface 228 axially spaced from the exterior surface 226 to define a thickness 230 of the generally closed end 222. There is also a peripheral wall 232 that extends between the open first end 222 and generally closed second end 224 of the third member 220. The peripheral wall 232 is illustrated as having a substantially smooth and even exterior surface 234 and an interior surface 236, although other shapes of the third member 220 are contemplated by the instant invention. The interior surfaces 228 and 236 define a cavity 238 of the third member 220. The interior surface 236 is so sized that the substantially cylindrical peripheral surface 202 of the second member 190 operatively mates therewith. More specifically, first portion 192 of the second member 190 is allowed to rotate, with guidance, within the cavity 238. Preferably, a bore 240 is disposed in the interior surface 236 of the peripheral wall 232 adjacent the open first end 22 and defining a second ledge 242. The second ledge 242 is configured to abut the generally planar surface of the end 166 of the first member 160 during assembly of the device 150. A second internal thread 244 is disposed in the bore 240 and is so sized that the second internal thread 244 operatively engages the first external thread 180 of the first member 160. The third member 220 also defines a second frustoconical peripheral surface portion 246 being so sized that the second frustoconical peripheral surface 246 abutingly mates with the first frustoconical peripheral surface portion 200 of the second member 190. An axial aperture 248 is formed through the thickness 230 of the generally closed second end 224. The axial aperture 248 is so sized that the second portion 214 of the second member 190 is passed therethrough such that the substantially cylindrical smooth surface portion 218 is disposed within the thickness portion 230 and is free to rotate about the longitudinal axis 152. Finally, the third member 220 defines a second plurality of ratchet teeth 250, also being disposed in a circular ring like pattern on the interior surface 228 of the generally closed second end 224 around the axial aperture 248. Each of the second plurality of teeth 250 has a first surface 252 disposed generally perpendicular to the interior surface 228 of the generally closed second end 224 and a second surface 254 disposed at an angle relative to the first surface 252.

Finally, the device 150 includes a bias member 260, such as a coiled spring or an equivalent) that is seated in or on the first and second spring seats, 182 and 198 respectively. The bias member 260 is configured to bias the first plurality of ratchet teeth 208 for operative engagement with the second plurality of ratchet teeth 250 during operation.

During assembly and installation of the device 150 onto the slack adjuster 10, the first portion 160 is threadably fastened to the threaded end of the rod guide member 12a. The second member 190 is inserted into the third member 220 and is fastened to the conventional bifurcated jaw 140. The third member 220 is than threadably fastened to the first member 160 after the bias member 260 is seated.

In operation, the cap member 160 adapts the ratchet assembly 150 to a standard slack adjuster 10 and seals the second member 190 and the bias member 260 from external elements. The ratchet housing 220 connects the cap member 160 and transfers tension load from the jaw 140 to the slack adjuster 10. The spring 260 maintains tension between the cap member 160 and the ratchet shaft 190, thus maintaining engagement and allowing at least rotational movement due to cam action. Furthermore, the first and second plurality of ratchet teeth, 208 and 250 respectively combine to allow free rotation of the first member 160 and the third member 220 about the second member 190 in one direction and prevent rotation in an opposite direction.

Thus, when the manual force is applied to the housing member 12 and is continued to be applied so as to cause rotation thereof, the first and second plurality of ratchet teeth, 208 and 250 respectively ratchet freely about one another allowing translation of the nut 34 on the thread 30 and, more particularly, allowing the elongated rod member 20 to change the longitudinal position relative to the housing member 12. Consequently, the length of the slack adjuster 10 is increased to increase the slack in the railcar brake rigging (not shown) and allow replacement of the brake shoes (not shown).

After the brake shoe change, the first operation of the rail car brake rigging (not shown) resets the length of the slack adjuster 10 by way of first surfaces 210 and 252 being locked, in abutting relationship, against one another.

Thus, the device 150 is configured to allow change in the length of the slack adjuster 10 simply by manually turning the housing member 12 without use of any tools (bars, wrenches, etc) and further without unpinning or removing the slack adjuster 10 from the brake rigging (not shown). The device 150 is also configured for ease of field installation and retrofit on slack adjusters presently in use in applications capable of accommodating a slight increase in the overall length of the slack adjuster 10.

The instant invention contemplates that the device 150 will operate without the need for the first member 160 by threadeably securing the third member 220 directly to the end of the rod guide member 12a of the slack adjuster 10 and accommodating the seat for the bias member 260, for example with a washer or flange (not shown) at the end 12a.

Now in reference to FIG. 9, therein is illustrated a ratchet assembly, generally designated as 350, that is mounted within the housing member 12 of the slack adjuster 10. Such ratchet assembly 350 includes a cone nut housing or a hollow sleeve 360 that is mounted adjacent the third housing portion 80 of the slack adjuster 10 of FIG. 1. Such cone nut housing 360 includes an internal thread 374 operatively cooperating with the external thread of the housing portion 78 and an axially opposed external thread 378 operatively cooperating with the internal thread of the housing portion 80. The first portion 370 further takes advantage of a shoulder 380 radially formed in the wall 380. The ratchet assembly 350 further defines a slot 384 formed at least through the wall of the cone nut housing 260 and is further formed through a wall of the housing portion 80.

There is also a second cone nut 400 that is essentially identical to the cone nut 44 of the slack adjuster 10. The second cone nut 400 is positioned adjacent to the cone nut 34 and is axially spaced therefrom. The second cone nut 400 configured so as to allow the second nut 400 to be forced into rotation. A spring 430 is positioned in the axial void between the cone nuts 34 and 400 and maintains the second cone nut 400 centered while preventing binding.

Any external sleeves, pry bar, pawl or ratchet activate and turn the second cone nut 400. Turning the second cone nut 400 has the same effect as pulling/pushing on the elongated rod 20 thus manually elongating/shortening the slack adjuster 10 without unpinning or removing it from the brake rigging (not shown).

It would be understood that the ratchet assemblies 150 and 350 have been described and illustrated in combination a tension type slack adjuster, the instant invention contemplates that ratchet assemblies 150 and 350 may be adapted for use on the compression style slack adjuster taught in Regular U.S. Utility Patent No. 4,662,485, as well as on other slack adjusters, for example of the type as manufactured by the New York Air Brake of

Watertown, NY under the model KDR-482-E.

Thus, the present invention has been described in such full, clear, concise and exact terms as to enable any person skilled in the art to which it pertains to make and use the same.

It will be understood that variations, modifications, equivalents and substitutions for components of the specifically described embodiments of the invention may be made by those skilled in the art without departing from the spirit and scope of the invention as set forth in the appended claims.