Patent Application
20150122144
The present disclosure relates to anti-rollback systems for track mounted vehicles and more particularly to silent anti-rollback systems.
The written disclosure herein describes illustrative embodiments that are non-limiting and non-exhaustive. Reference is made to certain such illustrative embodiments that are depicted in the figures, in which:
Track mounted carts or vehicles are often used in amusement rides or for transportation of humans, livestock, goods, or other materials. Wheels on the vehicle or track may be used to reduce resistance to movement of the vehicle. Often, the track mounted carts or vehicles are used to raise a payload along the track. On some amusement rides, for example, a vehicle carrying one or more passengers may be raised along a track to a high point where the vehicle can be released to roll down the track to gain speed and momentum for the amusement ride. The vehicle may be raised using a chain or other structure to move the vehicle against gravity up the track. Because the vehicles are being raised against gravity, a break in the chain or other structure can result in the vehicle falling or moving backwards along the track at dangerous speeds. Harm to human passengers or others nearby, as well as damage to goods, can result from such breakage.
Because of the danger of vehicles falling or sliding backwards down a track, anti-rollback devices and systems are often used to catch or stop the vehicle in the case of a system failure. In fact, anti-rollback systems are sometimes required by law on amusement rides or other track mounted vehicle systems. A number of considerations come into play with anti-rollback systems. One consideration is that the anti-rollback systems must have very low probability of failure. For example, the anti-rollback system must be very likely to operate even in the case of failure of other parts of a vehicle or track, or supporting systems. In many embodiments, it may be desirable that the anti-rollback system work even if there is a loss of electrical power or a failure of a motor or an engine.
Another consideration is that the anti-rollback systems must generally be structurally strong, such that the system can stop a loaded and heavy vehicle at what may be high speeds. Structures must be sufficiently robust that they are not likely to slip or break under the strain of forces that may be present. Another consideration includes how quickly the anti-rollback system engages in response to the vehicle or cart moving backwards along the track. For example, if the anti-rollback system engages more quickly, the speed and momentum of the vehicle are reduced. Slower speeds and momentum can reduce the likelihood of structural failure, as well as injury to humans or livestock in the vehicle or damage to goods.
Yet another consideration is the level of noise and wear and tear caused on the anti-rollback system when the vehicle is moving in a forward direction without any system failure. For example, in some embodiments, anti-rollback systems operate similarly to a ratchet where a pawl clicks past teeth as the ratchet or teeth move in relation to each other. Thus, a small amount of wear on the pawl and teeth can result with every click even though a vehicle is moving in a proper direction and no system failure has resulted. Additionally, the clicking and repeated impact between the pawl and teeth can cause loud sounds which can be harmful or unpleasant to passengers or operators.
The present application discloses systems, devices, and methods for providing anti-rollback for track mounted vehicles which may address one or more of the considerations discussed above. In one embodiment, for example, a system of the present disclosure provides for dependable and silent anti-rollback on a vehicle for an amusement ride.
In one embodiment, an anti-rollback device includes a pawl, a wheel, and a one-way bearing. The pawl may have a shape to selectively engage teeth on a track mounted plate. The wheel may be configured to roll on a surface of the track mounted plate. The one-way bearing may couple the wheel to the pawl. The one-way bearing may allow the wheel to rotate freely in a first direction and lock the wheel in relation to the pawl when the wheel rotates in a second direction to force the pawl to engage the teeth.
Turning to the figures,
The apparatus 100 includes a bracket 102 for mounting the apparatus to a frame of a vehicle or track. The bracket 102 includes a plurality of holes 124 through which bolts or other fasteners may be inserted to secure the bracket 102 to the vehicle or track. In some embodiments, the bracket may be welded to or built into a frame of a vehicle or track. The bracket 102 may function as a base for other parts of the apparatus 100 to provide a structure for supporting the other parts relative to each other and/or the frame of a vehicle or track.
The bracket 102 is coupled to a lock arm 104. The bracket includes flanges 126 which are pivotably coupled to the lock arm 104 using a lock arm bolt 106. The lock arm bolt 106 secures the lock arm 104 to the bracket 102 while allowing the lock arm 104 to pivot around the lock arm bolt 106 and pivot with respect to the bracket 102. The lock arm bolt 106 may be secured to the bracket 102 and lock arm 104 using threads, a pin, or another mechanism for keeping the lock arm bolt 106 from working free from the apparatus 100. The lock arm includes a first end 128 that limits movement of the lock arm 104 in relation to the bracket 102. For example, the first end 128 limits the lock arm 104 from pivoting past a specific angle with respect to the bracket 102. In one embodiment, if the lock arm is forced in an upwards direction (based on the depicted orientation) to a locked position, the load may be transferred to the bracket 102 via the lock arm bolt 106 and the first end 128 of the lock arm 104.
The lock arm 104 includes a second end 130 that is configured to support mechanisms for engaging stops or teeth on an anti-rollback plate. The second end 130 of the lock arm 104 is coupled to wheels 108 and a pawl 110 of the apparatus 100. The wheels 108 and pawl 110 are coupled to the lock arm 104 using an axle 112.
The axle 112 includes an elongated member which extends through and transverse to the lock arm 104. The axle 112 may extend through a hole of the lock arm. A small amount of friction between the lock arm and the axle 112 may hold the axle 112 in place with respect to the lock arm 104. The axle may include one or more threads, nuts, and/or pins to secure the axle 112 to the wheels 108, pawl 110, and/or the lock arm 104.
The axle 112 may operate as a one-way joint for the wheels 108. In one embodiment, the axle may include a rod member and bearings 114. For example, the wheels 108 may be coupled to the axle 112 using the bearings 114. The bearings 114 may include one-way bearings, which may also be known as clutch bearings, to provide the one-way joint for the wheels 108. In one embodiment, the pawl 110 is secured to the axle 112 in a manner such that the axle 112 and pawl 110 rotate together.
In one embodiment, the pawl 110 is configured to engage stops or teeth on a corresponding anti-rollback plate, which may be mounted to a frame of a track or vehicle. For example, if the anti-rollback apparatus 100 is mounted on a vehicle the anti-rollback plate may be located on a frame of a track on which the vehicle rides. The wheels 108 are placed to ride along a surface, such as a surface on the anti-rollback plate, as the vehicle and track move in relation to each other. In one embodiment, the axle 112 forms a one-way joint that allows the wheels 108 to spin freely in relation to the pawl 110 in one direction while limiting movement of the wheels 108 in relation to the pawl 110 when the wheels 108 rotate in the opposite direction.
The apparatus 100 is configured to bias the lock arm 104 and wheels 108 toward a locked position with respect to the bracket 102. Specifically, the apparatus 100 includes a spring 118 and bias bracket 120 to provide a force to hold the lock arm 104 away from the bracket 102 and in a locked position, such that the first end 128 of the lock arm engages the bracket 102 (see
The pawl 110 is shaped to engage stops on an anti-rollback plate or another location. For example, the pawl 110 includes an elongated nose shape on a first end 132 to correspond to teeth (see
The pawl 110 also includes a shape to engage the lock arm 104 on a second end 134. For example, the pawl 110 may be configured to be rotatable on the axle 112 between an engaged and disengaged position. In
The bracket 102, lock arm 104, pawl 110, axle 112, wheels 108, and or other components of the apparatus 100 may be formed of hardened materials that can handle a load of a given vehicle. For example, the components of the apparatus 100 may include metals, such as hardened steel or other alloys that can hold up under the forces and/or momentum of a falling or backwards-moving vehicle.
In one embodiment, the apparatus 100 can operate to stop a vehicle regardless of the orientation of the apparatus 100 and/or its location with respect to an anti-rollback plate. For example, because the wheels 108 and the friction between the wheels 108 and a running surface cause the pawl 110 to rotate, the pawl 110 can be rotated against gravity toward an engaged position. In fact, a significant amount of force may be generated to ensure that the pawl 110 engages corresponding teeth on an anti-rollback plate. Similarly, because the rotation of the pawl 110 toward the engaged position may be based on movement of the vehicle, the pawl 110 may be dependably rotated to engage stops and stop or slow backward movement.
In one embodiment, at least a small amount of friction is present between the lock arm 104 and the axle 112 such that the axle 112 and/or pawl 110 do not rotate with respect to the lock arm 104 unless the wheel 108 rotates in the second direction 304. For example, a rubber member between the axle 112 and the lock arm 104 may provide sufficient friction to hold the pawl 110 away from the teeth or stops of an anti-rollback plate so that the pawl does not hit each tooth or stop, causing noise. However, the friction between the lock arm 104 and the axle 112 may be small enough that when the wheel 108 rotates in the second direction 304 the wheel forces the pawl 110, via the bearings 114 and the axle 112, to rotate in the second direction 304 to engage teeth or stops to prevent the vehicle from moving in a backward direction. Similarly, if the pawl 110 is not in a disengaged position while the vehicle is moving in a forward direction, the pawl 110 may be forced toward the disengaged position by stops or teeth to overcome the resistance between the lock arm 104 and the axle 112 and place the pawl 110 in the disengaged position.
It will be understood by those having skill in the art that changes may be made to the details of the above-described embodiments without departing from the underlying principles presented herein. For example, any suitable combination of various embodiments, or the features thereof, is contemplated.
Any methods disclosed herein comprise one or more steps or actions for performing the described method. The method steps and/or actions may be interchanged with one another. In other words, unless a specific order of steps or actions is required for proper operation of the embodiment, the order and/or use of specific steps and/or actions may be modified.
Throughout this specification, any reference to “one embodiment,” “an embodiment,” or “the embodiment” means that a particular feature, structure, or characteristic described in connection with that embodiment is included in at least one embodiment. Thus, the quoted phrases, or variations thereof, as recited throughout this specification, are not necessarily all referring to the same embodiment.
Similarly, it should be appreciated that in the above description of embodiments, various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure. This method of disclosure, however, is not to be interpreted as reflecting an intention that any claim requires more features than those expressly recited in that claim. Rather, inventive aspects lie in a combination of fewer than all features of any single foregoing disclosed embodiment. It will be apparent to those having skill in the art that changes may be made to the details of the above-described embodiments without departing from the underlying principles set forth herein. The scope of the present invention should, therefore, be determined only by the following claims.
