Patent Application
20130233121
The present invention relates to handheld extension tools, and more particularly to extension tools for operating a hand wheel associated with a handbrake used on a railroad locomotive.
This invention relates to the field of tools used in the railroad industry by locomotive engineers to aid in the application release of locomotive engine vertical handwheel handbrakes. The operation of locomotive handbrakes is, in principle, the same as the handbrakes used on railroad cars. Application of the brakes means to set the handbrake to a “stop” position in which the locomotive will not move accidentally. Release of the brake means to set the handbrake to an “off” position in which the locomotive can be safely moved.
Locomotive handbrakes are placed on locomotives to be used in addition to the locomotive air brakes to keep the locomotives from moving while not in use, should the locomotive air brakes fail or be accidentally released by mistake. Handbrakes on locomotives are always left in the applied position when not being used.
One brake application release tool is shown in U.S. patent application Ser. No. 13/025,880, filed on Feb. 11, 2011. The tool is used for the application release of handbrakes on railroad freight and passenger cars. Where railroad car handbrakes are mounted on either the end or side of the car, the handbrakes on locomotive engines are typically mounted on the side of the locomotive engine compartment. The handbrake is operated from the locomotive walkway that extends the length of the engine compartment, from the rear of the locomotive to the locomotive cab. The handbrake is located so that the engineer or worker operates the brake at about waist or chest level relative to the handbrake wheel.
The handbrakes in both railroad cars and locomotives include a handbrake chain that tightens as the handbrake is applied by rotating the handbrake wheel. The biggest difference between handbrakes on railroad cars and handbrakes on locomotives is the amount of free slack in the handbrake chain. On railroad car handbrakes, this free slack is eliminated by about 2 to 4 revolutions of the wheel. However, in locomotive handbrakes, free slack is about 20 to 25 complete revolutions of the wheel. The handbrake must also be released completely when not in use, which requires reversing the process of setting the handbrake entirely. That is, turning the handwheel all the way until there is slack in the chain and the brake is fully released.
To begin the process of applying or releasing a locomotive handbrake, a railroad worker stands on the compartment walkway and grasps the handwheel with one or two hands. The worker then turns the handle in the clockwise direction to apply the brake, or in the counterclockwise direction to release the brake. This process may require the worker to re-grasp the wheel two to three times to complete one revolution of the handbrake wheel. Some operators may place two or three fingers at the junction of the handwheel inside rim and spoke, and rotate the handwheel continuously until all free slack is removed. Then, the worker grasps the handwheel at the highest point with one or both hands and fully applies the handbrake.
By trying to spin the handwheel with two or three fingers, an unsafe condition is created if the handwheel should suddenly stop and lock up. Some wheels offer continuous resistance to free spinning, and require too much force to utilize this method. This situation could also result in serious injury to the railroad worker's fingers. Therefore, a need exists for safe and effective tools for any railroad worker to remove the free slack in a handbrake chain.
Most new locomotives purchased by railroads around the time of filing, and those purchased in the prior decade, contain computers that monitor all aspects of the locomotive. These computers have sensors that trip an alarm should the handbrake not be completely released and someone tries to move the locomotive. Consequently, the handbrake handwheel must be rotated in the counterclockwise direction until it stops, and must be left in that position, in order for the locomotive computer to not trip the handbrake set alarm.
Should the locomotive handbrake handwheels have a permanently mounted handgrip on the handwheel, the handgrip would create a tripping or impact hazard, because it would be sticking out into the walking path of the railroad employee. Even if the handgrip were made to fold out of the way of the walking path, the handgrip could still become a tripping hazard due to bad maintenance or being accidentally left unfolded. The tripping hazard of a permanently mounted handgrip is increased by the fact that a high percentage of the times these walkways are traversed, they are done so at night and while the train is moving.
An extension tool is provided for enabling locomotive engineers and other railroad workers to easily remove the extreme amount of slack present in locomotives with vertical handwheel handbrakes. The tool comprises a spinning handle and a tool body connected to the handle for attaching to a handbrake wheel. The tool body has a tool body structure, a face that is constructed to sit against the handwheel, and jaws that clamp against the wheel. The jaws can be quickly opened or closed with an interior screw mechanism inside the tool body.
One goal of the present invention is to provide a tool that is both quickly attachable to and detachable from the vertical handbrake handwheel. This tool provides a secure method of turning the handbrake handwheel to safely and easily remove the extreme amount of slack in the chain.
Preferably, the tool comprises an elongated handle that freely rotates about a longitudinal axis. The freely rotating handle provides a user with a spinning grip, allowing the user to quickly and easily turn a handwheel. The tool also comprises a tool body, which further comprises two or more jaws that clamp to the handwheel. The tool body additionally comprises a screw mechanism for selectively tightening or releasing the jaws, in order to respectively attach or detach the tool from the handwheel as desired.
Preferably, the interior screw mechanism comprises a drawbar that extends through an interior of the handle, and is adapted to move along the longitudinal axis in order to selectively tighten or release the jaws. The screw mechanism may also comprise a threaded drawbar nut that interacts with a threaded portion of the drawbar to move the drawbar longitudinally, in order to tighten or release the jaws. In such embodiments, the tool may further comprise a compression spring that pushes against the drawbar, biasing the jaws into a certain position. The drawbar may further include a drawbar head that interacts with a drawbar head notch on each of the jaws, causing the jaws to undergo angular displacement with respect to the tool body.
In operation, a user attaches the tool to a wheel by fitting the jaws to the wheel, preferably at a spoke junction as shown in
A preferred embodiment of the tool includes a tool head body design so a face of the tool head fits flat against the outer junction between the handwheel rim and a spoke of the handwheel. Through the center of the tool head body there is a longitudinal hole centered around a longitudinal axis, preferably the full length of the tool head. Within the hole is a drawbar threaded on one end, and on the other end, provided with a double tapered, semi-rounded drawbar head larger than the diameter of the drawbar shaft. The drawbar is adapted to move along the longitudinal hole in order to selectively tighten or release the jaws. The tool head face has three slots at given angles, each slot constructed to receive a respective tool jaw. The three jaws are formed to bear against the inner and outer junction surfaces of the outer handwheel rim and one spoke of the wheel. A threaded drawbar nut is provided that interacts with the drawbar to longitudinally move the drawbar within the tool head in two directions, in order to tighten or release the jaws as desired by the operator.
Because of the way most handwheels are constructed, the three jaws are preferably rotationally asymmetric about the longitudinal axis in order to best accommodate the handwheel. However, some versions of the invention may have three jaws placed in rotational symmetry about the longitudinal axis. Other preferred versions of the invention use two jaws instead of three.
On preferred versions of the invention having three jaws, the jaws bear against the inner surface of the junction of the outer handwheel rim and one of the handwheel spokes. The jaws transmit multidirectional force to the handwheel rim. This is possible because, as the drawbar is tightened, each of the jaws pivots on a respective jaw attachment screw, causing the handwheel-spoke junction to be centered between the three jaws, and further causing the handwheel to be pulled toward the face of the tool head. This multidirectional force allows the tool to remain steady and in place while the handwheel is turned.
This tool 100 is employed to provide a handle extension to the existing locomotive handbrake wheel. It serves as a useful tool to help remove the extreme amount of slack in handbrake chain. However, this tool is not a leverage increasing device, as one of the inventor's prior applications is directed to. The tool also provides improved safety by allowing a safe and secure hand placement option that will prevent injuries to employees' fingers while rotating the handbrake wheel. When the tool is attached to a handbrake handwheel (as shown in
Although the depicted tool 100 is machined from aluminum, any suitable material may be used in accordance with the present invention. Such materials may include steel or other metals, rubber, wood, or plastic. For example, jaws 103 are preferably machined from a round piece of aluminum about 2.75″×6.25″ long, but other suitable materials may be used as further described below.
The depicted tool body includes three jaws 103 connected to the tool body structure 104. The jaws 103 grasp the handbrake wheel when the tool is in use. The jaws 103 are attached to the tool body structure 104 by the jaw mounting screws 114. Each jaw 103 moves inside a jaw slot 113, as depicted. Jaws 103 are adapted to undergo angular displacement with respect to tool body structure 104 in order to apply or release the tool 100. Tool 100 has a tool body face 102 that, when applied to a handwheel, rests against the outside of the handwheel, and by its large diameter of approximately 2¾ inches, it provides a stable connection to operate the handwheel. In this embodiment, the tool 100 is configured to be applied at the junction of the outside handwheel rim and one spoke of the handwheel.
The tool body structure 104 has a ⅜ inch hole drilled through its center, and centered about a longitudinal axis 117 (
Tool 100 further includes a rotating handle 106 that surrounds an elongated portion of drawbar 107, and an elongated portion of tool body structure 104 (
Because
Also, it should be noted that in the embodiment illustrated in
As force is applied to the drawbar 107 via the drawbar nut 110 (not shown in this figure), the drawbar head 101 begins to move toward the drawbar spring counter bore 112. This movement applies pressure to the compression spring 105. Further, this movement causes contact between a number of jaw drawbar head contact surfaces 306 and a drawbar head rounded taper 305, each jaw drawbar head contact surface 306 associated with a respective one of jaws 201-203. The contact between jaw drawbar head contact surfaces 306 and rounded taper 305 causes jaws 201-203 to move angularly toward the handwheel 210. As each of the three jaws 201-203 contact the handwheel 210, multidirectional pressure is applied to the handwheel 210 as designated by force arrows 308. The three jaws 201-203 pull towards each other and pull the handwheel down toward the tool body face. When jaws 201-203 are fully tightened, the tool 200 is substantially perpendicular to the outer rim of the handwheel 210. This connection provides a sturdy device for rotating the handwheel 210. Arrow 307 in
The depicted handwheel 210 shows one type of handwheel shape used on locomotives. The shape is designated the elongated-C wheel. On this type of wheel, the open side of the “C” faces away from the locomotive body.
After the tool has been attached to handwheel 210, the user then rotates handwheel 210 by grasping the rotating handle 106, and turning the handwheel in a circular motion until the locomotive handbrake is set or released, as desired. As the wheel turns, the handle 106 freely rotates around its longitudinal axis 117 (
The tool head body, jaws, and drawbar may be made of various materials, and different materials may be used to construct a single tool 100. For example, one version includes a tool head body, jaws, and drawbar that are made with CNC machining out of aluminum round rods and flat stock. The jaw mounting screws and anti-friction washer in this version are constructed of steel. The drawbar nut, in this embodiment is made from nylon, which is used due to the problem in soft materials, like aluminum, gauling when both the threaded end of the drawbar and drawbar nut are made out of aluminum. This can cause the drawbar nut to seize to the threads of the drawbar, thereby causing both components premature wear or damage. In mass production, the tool components can also be cast out of aluminum or aluminum type material that is easily cast, and will withstand the pressures required.
Another suitable material is injection molded plastic of different suitably strong plastic compounds that are known in the art. In mass production, injection molded plastic may provide cost advantages and still meet the mechanical strength required for the tool 100.
Besides injection molded plastic, many other suitable materials are available in both rods and flat material stock in all sizes needed to make the parts described herein. For example, probably the most widely known materials are ABS (acrylonitrile butadiene styrene) and PVC (polyvinyl chloride). These materials are widely available, and can be both molded and machined to size.
Another material widely available is nylon, which is used to construct the drawbar nut in some preferred embodiments. This material is available in both broad and flat stock in all needed sizes. It is easily CNC machined and may be used for the tool body, jaws, drawbar nut, and grip. Another material similar to nylon is Nylatron. It is widely available in all sizes and machineable, and can also be used for any of the tool body, jaws, drawbar nut, and grip.
Yet another material is Acetal, or polyoxymethylene plastic, which is also known by the leading brand name of Delrin. This material is extremely tough, and is commonly used in wheels for industrial class casters which carry extremely heavy loads. It is available in all suitable sizes and machineable to construct all of the parts listed above.
One of the toughest materials that may be used to produce very high quality and durable tools as described herein is UHMW, or ultrahigh molecular weight polyethylene. This material is machineable similar to the other plastics and available in all suitable sizes. This material is an excellent choice for all component parts, and a really good choice especially for constructing the jaws.
As listed above, these materials are but just a few of the available materials that may be used in constructing the devices described. Any material, or combination of materials for different parts, with suitable strength and rigidity to apply the force needed to turn the wheel may be used. A common railroad test for the force needed to finish setting the handbrake is 125 pound weight applied to the outer radius of the wheel as rotational force. While this force may vary as handbrake technologies vary, and a suitable margin of strength such as doubling or tripling this force may be required for some applications, this general guideline provides the testing methodology that may be used to select suitable materials. One preferred combination uses steel for the parts described above as employing steel, uses aluminum for the jaws, and uses plastics for the handle and tool body structure. Another variation uses steel for the spring and pins and plastic for the remaining parts.
The tool body has two jaws 103 connected to the tool body structure. The jaws 103 grasp the wheel when the tool is in use. The jaws 103 are attached to the tool body structure 104 by the jaw mounting screws 114. Each jaw 103 moves inside a jaw slot 113, as depicted. Jaws 103 are adapted to undergo angular displacement with respect to tool body structure 104 in order to apply or release the tool 300.
The tool has a tool body face 102 that rests against the outside of the handwheel, and by its smaller diameter of approximately 2 inches, it provides a stable connection to operate the handwheel. Generally, the two jaw version with its smaller diameter head allows for a smaller, slimmer tool that is easier to carry from engine to engine in railroad operations. The tool is applied at any suitable location along the outside hand wheel rim, either between spokes or near a spoke. It is noted that the depicted two jaw version may therefore be applied at wheel locations where a three jaw version may not be applied in some handwheel designs.
The tool body structure 104 has a ⅜ inch hole drilled through its center, and centered about a longitudinal axis 117. A drawbar 107 functions through this hole to move the jaws 103 back and forth. Drawbar 107 has a drawbar head 101 and a threaded drawbar end 116. In addition, drawbar 107 is attached to a compression spring 105 positioned to press against the drawbar head 101 in a manner to return the jaws 103 to the position shown in
On the threaded end 116 of the drawbar 107 is a drawbar nut 110. The drawbar nut 110, which rotated clockwise, pulls the drawbar head 101 against the drawbar compression spring 105, and thus causes the jaws 103 to rotate into a closed position. The drawbar nut 110 also operates to return the jaws 103 to the open position when it is turned counterclockwise. A drawbar nut antifriction washer 109, located between tool body structure 104 and drawbar nut 110, is provided to keep the drawbar nut 110 from eroding the end of the tool body structure 104.
Tool 300 further includes a rotating handle 106 that surrounds an elongated portion of drawbar 107, and an elongated portion of tool body structure 104. Rotating handle 106 freely rotates about longitudinal axis 117. The freely rotating handle 106 thus provides a user with a spinning grip, allowing him or her to quickly and easily turn a handwheel, as may be best understood with respect to
As used herein, whether in the above description or the following claims, the terms “comprising,” “including,” “carrying,” “having,” “containing,” “involving,” and the like are to be understood to be open-ended, that is, to mean including but not limited to. Only the transitional phrases “consisting of and “consisting essentially of,” respectively, shall be considered exclusionary transitional phrases, as set forth, with respect to claims, in the United States Patent Office Manual of Patent Examining Procedures (Eighth Edition, August 2001 as revised October 2005), Section 2111.03.
The above described preferred embodiments are intended to illustrate the principles of the invention, but not to limit the scope of the invention. Various other embodiments and modifications to these preferred embodiments may be made by those skilled in the art without departing from the scope of the following claims.
