Patent Publication Number: US-2003230159-A1

Title: Power brake lock

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
     [0001] This application is a §111 (a) application relating to commonly owned co-pending U.S. Provisional Application Serial No. 60/388,797, entitled “Power Brake Lock,” filed Jun. 14, 2002. 
    
    
     
       FIELD OF THE INVENTION  
       [0002] The present invention relates to locking devices and, more particularly, to devices used to lock down brake pedals of motor vehicles used during the launch and retrieval of boats from and onto boat trailers connected to the vehicles.  
       BACKGROUND OF THE INVENTION  
       [0003] Various types of motor vehicle foot pedal locking devices have been proposed in the past. Dunham U.S. Pat. No. 3,722,266 (“Dunham &#39;266 Patent”) discloses a tool for temporarily holding down an automobile brake pedal. The brake tool disclosed in the Dunham &#39;266 Patent contains a flat end plate fitted on one end of a tubular member, and, when the brake tool is engaged, the plate is positioned against the front side of an automobile&#39;s driver seat. The Dunham &#39;266 Patent, however, does not disclose that the plate is flexible so as to enable the entire surface of one side of the plate to remain in constant contact with the driver&#39;s seat. As a result, the brake tool may not always maintain the correct or constant pressure on the brake pedal.  
       [0004] The Dunham &#39;266 Patent also discloses the use of a smooth rubber boot fitted on one end of a solid metal bar that is placed on the brake pedal. However, the use of this type of boot may slip off the brake pedal, especially in wet conditions.  
       [0005] The Dunham &#39;266 Patent also discloses that a compression coil spring exerts force against a collar when the brake tool is engaged. However, the Dunham &#39;266 Patent does not disclose any means for preventing the spring from wearing out the collar over an extended period of use of the brake tool.  
       [0006] In addition, the brake tool disclosed in the Dunham &#39;266 Patent is not adjustable to fit vehicles with having different distances between the bottom of the vehicle&#39;s driver seat and the brake pedal. As a result, this brake tool does not control the correct brake pressure from vehicle to vehicle. Finally, the brake tool disclosed in the Dunham &#39;266 Patent does not extend above the front of the vehicle&#39;s driver seat when in operation. As a result, it is more difficult for an operator of the vehicle to engage or disengage the brake tool from a normal driving position.  
       [0007] Phillips U.S. Pat. No. 3,910,135 (“Philips &#39;135 Patent”) discloses an accelerator pedal holding device. The Phillips &#39;135 Patent discloses the use of a threaded rod to enable the accelerator pedal holding device to be adjusted to fit a variety of motor vehicles. However, the threaded rod is rigid and, therefore, does not compensate for any “pulsing” of the vehicle&#39;s accelerator pedal while the vehicle&#39;s engine is running. As a result, this accelerator pedal holding device may not always maintain the desired predetermined position of the accelerator pedal.  
       [0008] Neither the Dunham &#39;266 Patent nor the Phillips 135 Patent discloses means that enable operators of the respective devices to easily and comfortably exert ample downward pressure from the top of each device. Without such means, operators of the devices may be inclined to grasp the main body of the devices to push down in an effort to engage the devices. This may result in the operator losing his grip on the devices.  
       SUMMARY OF THE INVENTION  
       [0009] The problems and disadvantages associated with the prior art are overcome by the present invention, which includes a cylinder and a piston mounted for reciprocating movement relative to each other. More particularly, the piston is moveable between an extended position, in which an external or free end of the piston is remote from the cylinder, and a retracted position, in which the external end of the piston is proximate to the cylinder. A spring or some other urging mechanism is positioned within the cylinder so as to urge the piston away from its retracted position and towards its extended position. The external end of the piston is adapted to engage an exposed surface of a motor vehicle&#39;s brake pedal. The cylinder includes a hook member or some other mechanism adapted to engage an exposed surface of a motor vehicle&#39;s driver seat. The position of the hook member on the cylinder is adjustable so as to accommodate varying distances between the brake pedal and the driver seat.  
       [0010] In use, the present invention functions to lock down a motor vehicle&#39;s brake pedal when a boat is being launched or retrieved from or onto a boat trailer, which is connected to the vehicle, at a boat launch ramp. Frequently, the vehicle is vacant while the operator is launching or retrieving the boat from the trailer. For vehicles containing automatic transmissions, the operator will typically place the vehicle in “Park” and may apply the vehicle&#39;s emergency brake in order to prevent the vehicle from moving during the launch or retrieval of the boat. For vehicles containing manual transmissions, the operator would simply engage the parking brake (which only locks the rear wheels of the vehicle) to prevent the vehicle from moving. However, an operator of any type of vehicle would typically want additional security that all four wheels of the vehicle will not move when launching or retrieving the boat. For example, when a boat is drawn onto a boat trailer, the weight of the boat is primarily on the back of the trailer and the front of the trailer tends to lift the back of the tow vehicle. In turn, the vehicle&#39;s weight on the rear wheels decreases and the weight on the front wheels increases. The grip of the rear wheels is significantly reduced due to this weight transfer. As a result, use of the parking brake as the only means to keep the vehicle stationary is not effective. The present invention solves this problem by employing a spring and a piston, which cooperate to lock down the vehicle&#39;s brake pedal. As a result, constant pressure is maintained on the brake pedal and, thus, the vehicle&#39;s brakes are applied to all wheels.  
       [0011] Also, wet conditions are prevalent at boat launch and retrieval sites. As a result, the vehicle&#39;s foot pedals usually become wet and slippery from the operator&#39;s wet shoes or feet. In these wet conditions, there is a concern that a foot pedal holder that includes a smooth tip will slip off a wet pedal. The present invention employs an antifriction mechanism at the external end of the piston, which enables it to firmly grip the exposed surface of the vehicle&#39;s brake pedal, especially in those wet conditions frequently encountered at boat launch sites.  
       [0012] In addition, an operator will typically keep the vehicle&#39;s engine running while he or she launches or retrieves the boat. However, the vibrations of a running engine can cause the vehicle&#39;s brake pedal to “pulse.” This frequently occurs in vehicles containing power assisted, hydraulic brake systems. As a result, there is a concern that a brake pedal holding device would not maintain constant pressure on the brake pedal while pulsing occurs. As described in greater detail below, the invention, by use of a spring or other urging mechanism, ensures that the correct and constant pressure is always maintained on the brake pedal, even when the brake pedal is pulsing.  
       [0013] Finally, not all vehicles and their operators are alike. Different vehicles have driver seats that are different in size, shape and style. Furthermore, the operators have different heights and leg lengths, resulting in a vehicle&#39;s driver seat being adjusted to accommodate the operator&#39;s height and leg length. Therefore, there is a need for a brake pedal holder to be as accommodating. The present invention employs an adjusting mechanism that allows for it to be adjusted for use between different types of vehicles and different driver seat positions, while maintaining the correct and constant pressure of the brake pedal.  
       [0014] Although the present invention has been adapted for use when launching and retrieving a boat from or onto a boat trailer and in wet conditions, the present invention can be utilized in other scenarios, environments and conditions.  
       [0015] Further features and advantages of the invention will appear more clearly on a reading of the detailed description of a preferred embodiment of the invention, which is given below by way of example only with reference to the accompanying drawings. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0016] For a better understanding of the present invention, reference is made to the following detailed description of an exemplary embodiment considered in conjunction with the accompanying drawings, in which:  
     [0017]FIG. 1 is a perspective view of the power brake lock constructed in accordance with an exemplary embodiment of the present invention;  
     [0018]FIG. 2 is a side cross-sectional view, taken along section line II-II and looking in the direction of the arrows, of the power brake lock shown in FIG. 1;  
     [0019]FIG. 3 is a side view of the power brake lock of FIGS. 1 and 2 which shows the present invention in use; and  
     [0020]FIG. 4 is a cross-sectional view, taken along section line IV-IV and looking in the direction of the arrows, of the power brake lock of FIG. 3 that shows the present invention in use. 
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS  
     [0021] Referring to FIGS. 1 and 2, a power brake lock  10  includes a cylinder (i.e., tubular member)  12  that is rigid and hollow. The cylinder  12  is a base for other components of the power brake lock  10 . For instance, a cap  14  is firmly mounted on an upper end  16  of the cylinder  12 , the cap  14  having a rounded outer surface  18  for a purpose to be described hereinafter.  
     [0022] A compression coil spring  20  is slidably positioned within the cylinder  12 . An upper end  22  of the spring  20  abuts against an inside surface  24  of the cap  14 . A washer  26  is positioned inside the cylinder  12  and abuts against a lower end  28  of the spring  20 .  
     [0023] A piston  30  is slidably mounted in a lower end  32  of the cylinder  12  for reciprocating movement relative thereto. The piston  30  contains a first collar  34 , which is fitted around and attached proximate to an upper end (i.e., internal end)  36  of the piston  30 . The first collar  34  functions as a piston ring to promote the centering of the piston  30  within the cylinder  12 . The washer  26  prevents the lower end  28  of the spring  20  from wearing out the first collar  34  over an extended period of use of the power brake lock  10 . The piston  30  also contains a second collar  38 , which is fitted around and attached to the piston  30  remote from the upper end  36  of the piston  30 , and is spaced apart from the first collar  34 . The location where the second collar  38  is attached to the piston  30  determines how far the piston  30  extends outward from the lower end  32  of the cylinder  12 . The second collar  38  also functions as a piston ring to promote the centering of the piston  30  within the cylinder  12 .  
     [0024] A lower end (i.e., external end)  40  of the piston  30  has a toothed tip  42  integrally formed therein for a purpose to be described hereinafter. The lower end  40  of the piston  30  also includes a colored mark  43  of a predetermined length that longitudally extends from the tip  42 , and circumferentially around the lower end of the piston  30 . The mark  43  functions as an indicator to show that the power brake lock  10  is properly adjusted when engaged. In any event, the color of the mark  43  is preferably black, but other colors or shades can be utilized. The color of the mark  43  should be different than that of the piston  30 .  
     [0025] A flanged insert  44  is secured within an opening  46  of the lower end  32  of the cylinder  12  and around the piston  30 . The insert  44  has a radially extending flange  48 , which abuts against the lower end  32  of the cylinder  12 . The insert  44  cooperates with the second collar  38  to limit the distance the piston  30  extends outward from the opening  46  of the lower end  32  of the cylinder  12 . The insert  44  also promotes the centering of the piston  30  within the cylinder  12 .  
     [0026] A pair of adjustable band clamps  50  and  52  is fitted around the outer-surface  54  of the cylinder  12 . Each band clamp  50  and  52  contains a tightening screw  56  and  58 . The tightening screws  56  and  58  are preferably worm-drive screws.  
     [0027] A stop hook  60  is mounted to the outer surface  54  of the cylinder  12  by the band clamps  50  and  52 . The band clamps  50  and  52  allow the stop hook  60  to be adjusted and secured in any location around the outer surface  54  of the cylinder  12 . Other attachment means are available to adjust and secure the stop hook  60  to the outer surface  54  of the cylinder  12 .  
     [0028] In a preferred embodiment of the invention, the cylinder  12 , the cap  14 , the piston  30 , the collars  34  and  38  and the insert  44  are manufactured from Schedule 40 PVC or gray electrical conduit and the washer  26  is manufactured from steel. However, these components may be made from other materials. Preferably, the cap  14  and the insert  44  are secured to the cylinder  12  and the collars  34  and  38  are secured to the piston  30  with PVC glue. However, the cap  14  and the insert  44  can be secured to the cylinder  12 , and the collars  34  and  38  can be secured to the piston  30  by other adhesives or by other means.  
     [0029] Furthermore, the ideal dimensions of the cylinder  12  are approximately 23.75 inches in length, 1.315 inches outside diameter and 1.049 inches inside diameter, with the ideal dimensions of the piston  30  being 21.5 inches in length overall, 0.840 inches outside diameter and 0.622 inches inside diameter. In addition, the clearance between the outside surfaces of the collars  34  and  38  and an inside surface  39  of the cylinder  12  is preferably 0.02 to 0.03 inches. Similarly, the clearance between the inside surface of the insert  44  and outside surface of the piston  30  is ideally 0.02 to 0.03 inches. The dimensions of these components, however, may be altered accordingly.  
     [0030] In an exemplary embodiment, the spring  20  is made from 0.080 inch steel wire, is 0.875 inches in diameter and 12 inches long, contains approximately 3.3 coils per inch, and has a spring constant of 3.5 pounds per inch or 42 pounds overall when fully compressed. The dimensions and characteristics of the spring  20  can be altered.  
     [0031] Preferably, the band clamps  50  and  52  are #301 stainless steel bands and are 0.023 inches thick. The tightening screws  56  and  58  are preferably made from zinc-plated steel, but they can be made from other materials.  
     [0032] Finally, the stop hook  60  is preferably made of hardened steel wire with a {fraction (5/32)}-inch diameter, and may contain a chrome finish. Alternatively, the stop hook  60  can be made from other materials and have a different diameter size and appearance. The distance between the outer-surface  54  of the cylinder  12  and the outward tip  62  of the stop hook  60  is preferably 3.5 inches. The length of the stop hook  60  can be increased or decreased as desired.  
     [0033] In use, as shown in FIG. 3 and FIG. 4, the power brake lock  10  is placed in contact between a motor vehicle&#39;s brake pedal  64  and driver seat  66 . The stop hook  60  can be adjusted and secured in any position around the outer surface  54  of the cylinder  12 . This allows the power brake lock  10  to be used in connection with different types of vehicles or different positions of a vehicle&#39;s driver seat  66 . To adjust the position of the stop hook  60  along the cylinder  12 , the tightening screws  56  and  58  are loosened which, in turn, loosens the band clamps  50  and  52 . This enables the stop hook  60  to slidably move along the outside surface  54  of the cylinder  12  and be positioned accordingly. Once the stop hook  60  is adjusted, the tightening screws  56  and  58  are tightened which, in turn, tightens the band clamps  50  and  52  around the outside surface  54  of the cylinder  12  and the stop hook  60  until the stop hook  60  is firmly secured.  
     [0034] The toothed tip  42  is placed against the outer surface (i.e., exposed surface)  68  of the brake pedal  64 . The toothed tip  42  securely grips the outer surface  68  of the brake pedal  64  so as to prevent the power brake lock  10  from slipping off the brake pedal  64 , especially in wet conditions typically encountered at boat launch sites. Preferably, the power brake lock  10  is positioned perpendicularly to the outer surface  68  of the vehicle&#39;s brake pedal  64  so that the entire surface area of the toothed tip  42  abuts the outer surface  68  of the brake pedal  64 . By placing the power brake lock  10  in this position, maximum efficiency of the toothed tip&#39;s  42  gripping capability of the outer surface  68  of the brake pedal  64  is achieved. Alternatively, the lower end  40  of the piston  30  can include other antifriction mechanisms formed therein or attached thereto adapted to grip the outer surface  68  of the brake pedal  64 , such as a rubber pad or a rubber cap (not shown in the Figures).  
     [0035] Thereafter, a user of the device exerts downward pressure against the cap  14 . The cap  14  enables a user to comfortably grip the power brake lock  10  and easily exert ample downward pressure when using the device. Preferably, the outer surface  18  of the cap  14  is rounded so as to provide extra comfort for an operator using the device. Alternatively, the cap  14  can have other shapes and sizes. As pressure is exerted, the cylinder  12  slides over the piston  30 , which remains substantially stationary. The collars  34  and  38  keep the piston  30  centered within the cylinder  12  as the cylinder  12  slides over the piston  30 . As the cylinder  12  slides over the piston  30 , the spring  20  is compressed between the inner surface  24  of the cap  14  and the washer  26 . Downward pressure is continuously increased until the brake pedal  64  is fully depressed and the stop hook  60  clears the bottom front surface  70  of the driver seat  66  so as to be enable the stop hook  60  to abut against said surface  70 . At this point, the piston  30  is situated in a retracted position.  
     [0036] Once the power brake lock  10  is in position to enable the stop hook  60  to be placed against the bottom front surface  70  of the driver&#39;s seat, the user releases pressure against the cap  14 . As pressure is released from the cap  14 , the spring  20  expands. Upon expansion of the spring  20 , the upper end  22  of the spring  20  exerts force against the inside surface of the  24  of the cap  14  and the lower end  28  of the spring  20  exerts force against washer  26  which, in turn, exerts force against the first collar  34 . As a result, the cylinder  12  slides upward and away from the piston  30  and the piston  30  is urged towards an extended position. Alternatively, other urging mechanisms, such as a leaf spring or a pneumatic mechanism, can be utilized to urge the piston  30  towards its extended position.  
     [0037] The cylinder  12  slides upward until the stop hook  60  abuts against the bottom front surface  70  of the seat  66 . The stop hook  60  may be shaped so as to conform to the shape of the bottom front surface  70  of the driver seat  66 . This allows for the power brake lock  10  to maintain the correct and constant pressure on a brake pedal  64 . Alternatively, other mechanisms adapted to engage the driver seat  66  can be utilized. The mark  45  functions as an indicator to show that the power brake lock  10  is properly adjusted when engaged. Ideally, the flange  48  lines up with the top of the mark  43  when the power brake lock  10  is engaged. When engaged in this manner, the power brake lock  10  applies the correct amount of pressure on the brake pedal  64 . Alternatively, other indicia may be utilized to show that the power brake lock  10  is properly adjusted when engaged.  
     [0038] As the power brake lock  10  is engaged, constant pressure is maintained on the brake pedal  64  and the vehicle&#39;s brakes are applied. This allows an operator to exit the vehicle to launch or retrieve his boat from or onto the trailer connected to the vehicle with the assurance that the vehicle&#39;s brakes are applied and the vehicle&#39;s wheels will not move. Also, the piston  30  and the spring  20  cooperate with each other to allow the device to compensate for any pulsing of the brake pedal  64  while the vehicle&#39;s engine is running. This allows for the power brake lock  10  to maintain the correct and constant pressure on the brake pedal  64 . Also, when engaged, the power brake lock  10  extends above the front of the seat  66 . This enables the vehicle&#39;s operator to engage and disengage the power brake lock  10  from a normal driving position.  
     [0039] It should be understood that the embodiments described herein are merely exemplary and that a person skilled in the art may make many variations and modifications without departing from the spirit and scope of the invention. Accordingly, all such variations and modifications are intended to be included within the scope of the invention as defined in the appended claims.