Patent Application
20060202550
The present invention relates, in general, to a truck-mounted brake assembly and, more particularly, this invention relates to an overload protection device for a truck-mounted brake assembly disposed on a railway car.
Prior to the present invention, the brakes on a truck-mounted brake assembly operate through the brake rigging either pneumatically, in response to the supply and release of compressed air at a brake cylinder device, or manually, in response to the operation of the railway car hand brake.
As illustrated in
This counterclockwise rotation of the equalizing lever results in the force-transmitting member being moved in the direction of the right hand, to effect counterclockwise rotation of the equalizing lever about its pivot pin. A portion of the force-transmitting member is secured to the fixed end of the brake cylinder, where resistance to movement is encountered at the end of the equalizing lever connected to the force-transmitting member by the pin, so that this lever acts as a second-class lever.
The force exerted at the other end of the equalizing lever from the force-transmitting member causes the equalizing lever to pivot about its connection with the force-transmitting member and thereby move the brake beam in the direction of the right hand through the connection of the equalizing lever with the strut bar, thereby bringing the brake shoes of the brake head and brake shoe assemblies associated with the brake beam into engagement with the wheel treads of the wheel/axle unit.
Once this brake shoe engagement occurs, the connection of equalizing lever with the force-transmitting member becomes solid and the equalizing lever becomes a second-class lever. Thus, the continued expansion of the free end of the brake cylinder causes a counterclockwise rotation of the equalizing lever to take place by pivotal rotation about the pin connection of the equalizing lever with the force-transmitting member.
Accordingly, the force of expansion of the brake cylinder acts through the pin of the equalizing lever and the strut bar to force the brake beam in the direction of the left-hand, thereby bringing the brake shoes of the brake head and the brake shoe assemblies associated with the other brake beam into engagement with the wheel treads of the second wheel/axle unit. An example of this type of truck-mounted brake assembly is taught in U.S. Pat. No. 4,613,016. The teachings of this patent are incorporated herein by reference thereto.
Similarly, rotation of the end of the actuating lever in a counterclockwise rotation, when the handbrake chain is taken up in a well-known manner, affects the same result. An example of this type of truck-mounted brake assembly is taught in U.S. Pat. No. 5,069,312. The teachings of this patent are incorporated herein by reference thereto.
A common practice in the railway industry is to have both the pneumatic and manual brake systems activated at the same time on a single railcar as a precaution against unwanted or unexpected movement of the car. This multiplies the forces on the brake assembly. Therefore, the brake beams may be subjected to a force exceeding their ultimate load capacity, thus causing deflection and premature failure. The present invention is designed with a preloaded compression member to absorb the excess force before deflection and possible failure of the brake beam occurs.
In a first aspect, the present invention provides an overload protection device for a truck-mounted brake assembly comprising a body member having a first end, a second end, at least one cavity of a predetermined size and shape disposed within the body member, and a compression member of a predetermined size, shape, material, and load rating, having a primary end and a secondary end. The compression member is compressed to a predetermined initial load, and is disposed within the cavity of the body member. The present invention further includes a first means secured to and disposed on the first end of the body member for engagement with a portion of a brake assembly, and a second means disposed on the second end of the body member for attaching to a force-transmitting member. A first portion of the second means is engageable with the compression member for transmitting an excess force generated from a railcar brake assembly to the compression member, whereby the overload protection device will compensate for a potential railcar brake overload condition.
In a further aspect, the present invention provides an overload protection device for a truck-mounted brake assembly comprising a body member having a first end, a second end, at least one cavity of a predetermined size and shape disposed within the body member and a compression member of a predetermined size, shape, material and load rating. The compression member is compressed to a predetermined initial load and is disposed within the cavity of the body member. A flange of a predetermined size and shape has a first surface and a second surface. The first surface is disposed on the second end of the body member. A first means is secured to and disposed on the first end of the body member for engagement with a portion of the brake assembly. A second means is reciprocally mounted adjacent the second end of the body member for attaching to a force-transmitting member. A first portion of the second means is engageable with the compression member for transmitting an excess force generated from a railcar brake assembly to the compression member. A retaining element is secured to and disposed on the second surface of the flange. The retaining element has an aperture of a predetermined size and shape concentrically disposed therein, wherein a second portion of the second means is reciprocally disposed therein. The overload protection device will compensate for a potential railcar brake overload condition.
In a still further aspect, the present invention provides an overload protection device for a truck-mounted brake assembly comprising a body member having a first end, a second end, and at least one cavity of a predetermined size and shape disposed within the body member. A compression member of a predetermined size, shape, material and load rating has a primary end, a secondary end and a concentric bore of a predetermined size and shape disposed from the primary end to the secondary end. The compression member is disposed within the cavity of the body member. A first means is secured to and disposed on the first end of the body member for engaging a portion of the brake assembly. A second means is disposed within the concentric bore of the compression member and is engageable with the compression member and connectable to a force-transmitting member. A securement member is disposed on the second end of the body member for securing the compression member in the cavity of the body member, whereby the overload protection device will compensate for a potential railcar brake overload condition.
In yet still a further aspect, the present invention provides an overload protection device for a truck-mounted brake assembly comprising a body member having a first end, a second end and at least one cavity of a predetermined size and shape disposed within the body member. The first end of the body member has an aperture of a predetermined size and shape concentrically disposed therein and the second end has an opening of a predetermined size and shape concentrically disposed therein. A compression member of a predetermined size, shape, material and load rating has a first end, a second end and a concentric bore of a predetermined size and shape disposed from the first end to the second end. The compression member is compressed to a predetermined initial load and is disposed within the cavity of the body member. The present invention additionally includes a first element having a primary end and a secondary end. The first element is disposed through the first aperture in the first end of the body member and through the concentric bore of the compression member. The first element further has an attachment for engagement with a portion of the brake assembly. A securement means is disposed on the secondary end of the first element and is engageable with the second end of the compression member. A second element is disposed on the second end of the body member for attaching a hand brake chain, whereby an excess force is transmitted through at least one of a railcar hand brake chain, a brake assembly, and a combination of a railcar hand brake chain and brake assembly to the compression member, whereby the overload protection device will compensate for a potential railcar brake overload condition.
It is, therefore, one of the primary objects of the invention to provide an overload protection device which will substantially minimize the possibility of overloading the brake beams disposed on a railway vehicle.
Another object of the present invention is to provide an overload protection device which can be readily retrofitted into existing railway vehicle brake systems.
Still another object of the present invention is to provide an overload protection device which is relatively inexpensive to manufacture.
Yet another object of the present invention is to provide an overload protection device which will require a minimum amount of maintenance.
A further object of the present invention is to provide an overload protection device which is relative easy to install.
In addition to the various objects and advantages of the invention that have been described above, various other objects and advantages of the invention will become more readily apparent to those persons skilled in the relevant art from the following more detailed description of the invention, particularly, when such description is taken in conjunction with the attached drawing figures and the appended claims.
Prior to proceeding to a more detailed description of the invention, it should be noted that identical components having identical functions have been designated with identical reference numerals for the sake of clarity.
Refer now more particularly to
A compression member 20 of a predetermined size, shape, material and load rating is compressed to a predetermined initial load and disposed within the cavity 18 of the body member 12.
Preferably, the compression member 20 is selected from the group consisting of a compression spring, Belleville spring and an elastomer. The preferred elastomer is hytrel. It is also preferred that the predetermined initial load of the compression member 20 is about 10,000 pounds.
A first means 22 is secured to and disposed on the first end 14 of the body member for engagement with a portion of a brake assembly. A flange 26 of a predetermined size and shape has a first surface 28 and a second surface 30. The preferred shape of the flange 26 is annular. The first surface 28 is disposed on the second end 16 of the body member 12. A second means, generally designated 24, is disposed on the second end 16 of the body member 12 for attaching to a force transmitting member. A first portion 32 of the second means 24 is engageable with the compression member 20 for transmitting an excess force generated from a railcar brake assembly to the compression member 20. Preferably, the first portion 32 is a plate-like member. A retaining element 34 is secured to and disposed on the second surface 30 of the flange 26. The retaining element 34 has an aperture 36 of a predetermined size and shape concentrically disposed therein; wherein a second portion 38 of the second means 24 is reciprocally disposed therein. Preferably, the second portion 38 is a push rod, and the retaining element 34 has an attachment means 40 to said flange 26, which is a plurality of bolts having a predetermined length and diameter. The overload protection device 10 will compensate for a potential railcar brake overload condition.
Now refer more particularly to
Preferably, an alignment means 44, which is at least one guide pin of a predetermined length and diameter, is disposed within the cavity 18 of the body member 12 for engagement with the compression member 20. This alignment means 44 will maintain the compression member 20 in a predetermined location. It is also presently preferred that the compression member 20 be selected from the group consisting of a compression spring, a Belleville spring and an elastomer. The presently preferred elastomer is hytrel. It is also preferred that the predetermined initial load of the compression member 20 is about 10,000 pounds. A first means 22 is secured to and disposed on the first end 14 of the body member 12 for engaging a portion of a brake assembly. It is presently preferred that the first means 22 is an integrally cast coupling device. A second means 24 is disposed within the concentric bore 42 of the compression member 20. This second means 24 is engageable with the compression member 20 and connectable to a force-transmitting member (not shown). Preferably, the second means 24 is a cylindrical tube having a primary end 46 and a secondary end 48 disposed within the concentric bore 42 of the compression member 20. Also, it is presently preferred that the second means 24 has a threaded inside diameter 54 to accept a threaded push rod.
The primary end 46 has a retaining member 50 disposed thereon which is engageable with the compression member 20. Preferably, the retaining member is a washer of a predetermined thickness, inside diameter, and outside diameter. The secondary end 48 has a compression element 52 disposed thereon. The compression element 52 is engageable with the compression member 20.
Preferably, the compression element 52 is a washer of a predetermined thickness, inside diameter and outside diameter. A retaining element 34 is secured to and disposed on the second end 16 of the body member 12 for securing the compression member 20 in the cavity 18 of the body member 12. The overload protection device 10 will compensate for a potential railcar brake overload condition.
Now refer more particularly to
It is also preferred that the predetermined initial load of the compression member 20 is about 10,000 pounds. A first element, generally designated 60, has a primary end 46 and a secondary end 48. Preferably, the secondary end 48 is threaded. The first element 60 is disposed through the first aperture 56 in the first end 14 of the body member 12, and through the concentric bore 42 of the compression member 20. The first element 60 has an attachment 62 on the primary end 46 for engagement with a portion of a brake assembly (not shown). Preferably, the attachment 62 is a ring of a predetermined size and material, which is welded to the primary end 46 of the first element 60. A securement means 66 is disposed on the secondary end 48 of the first element 60, and engageable with the compression member 20. It is presently preferred that the securement means 66 be a threaded nut of a predetermined size disposed on the secondary end 48 of the first element 60. A second element 64 is disposed on the second end 16 of the body member 12 for attaching a hand brake chain. Preferably, the second element 64 is substantially unshaped, and is welded to the second end 16 of the body member 12. When an excess force is transmitted through at least one of a railcar hand brake chain and a brake assembly, and a combination of a railcar hand brake chain and a railcar hand brake assembly to the compression member 20, the overload protection device 10 will compensate for a potential railcar brake overload condition.
Although the invention has been shown in connection with certain specific embodiments, it will be readily apparent to those skilled in the art that various changes in form and arrangement of parts and method may be made to suit requirements without departing from the spirit of the invention and the scope of the appended claims.
