Abstract:
A hydraulic system bleed device for applying pressure to a pedal associated with a hydraulic system so as to permit the hydraulic system to be bled by a single person. The hydraulic system bleed device includes a cylinder with an internal compression spring, extension shafts extendable from within the cylinder, a telescoping extension shaft, a pedal attachment assembly, a steering wheel attachment assembly, and a lever for compressing the cylinder spring to provide an urging force against a hydraulic system pedal.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates to tools used for bleeding a hydraulic system. Specifically, the present invention relates to a hydraulic system bleed tool which simplifies the bleeding process and allows for a single person to accomplish the bleeding process.  
       BACKGROUND OF THE INVENTION  
       [0002]     Hydraulic systems are commonly used in vehicles and other equipment in various applications such as brake systems, clutch systems, and auxiliary systems. Hydraulic systems work because the hydraulic fluid within these systems in non-compressible. However, maintenance on these systems typically requires that the hydraulic system be opened to the atmosphere such that air is introduced into the system. Because air is compressible, introduction of air into a hydraulic system comprises the operation of such hydraulic systems because pressure applied to the hydraulic fluid must first compress the air trapped in the system. Thus, at the conclusion of such maintenance activities, it is essential to the proper operation of such systems that all air be removed from the hydraulic system.  
         [0003]     This process is generally known as “bleeding” the system, a process by which air is removed from the hydraulic system. This process is well known and is most frequently used in association with maintenance on braking systems on all manner of vehicles and equipment.  
         [0004]     Presently, the simplest and most cost effective method of bleeding a brake system is to open bleed ports or fittings in the brake system and then apply pressure to the system by depressing the brake pedal. However, this generally requires the labor of two persons; one to depress the brake pedal, and the second to monitor the flow of brake fluid through the bleed ports. Because two persons are needed to perform this process, the labor costs associated with this type of maintenance are effectively doubled. Thus, there is a need in the art for a device that allows a single person to bleed a hydraulic system and thereby reduce the labor costs associated with this maintenance activity.  
       SUMMARY OF THE INVENTION  
       [0005]     The present invention provides the art with a hydraulic system bleed device that allows a single person to bleed a hydraulic system. The hydraulic system bleed device of this invention comprises a spring loaded cylinder which is positionable between a vehicle steering wheel and a brake pedal. Once positioned, operation of a compression lever compresses the cylinder spring applying a downward force on the connected pedal. This downward force pressurizes the hydraulic system.  
         [0006]     The hydraulic system bleed device of the present invention allows a single person to bleed a hydraulic system. After the tool is positioned and compressed, the bleed ports may be opened to allow entrained air to escape. A single mechanic can perform this maintenance because a second person is no longer needed inside the vehicle to manually apply pressure to the hydraulic system being bled.  
         [0007]     It is an object of the present invention to provide a hydraulic system bleeding device that allows one person to bleed a hydraulic system. Another object of the present invention is to provide simple and effective connections that allow the hydraulic system bleed device to easily be attached to pedals of various shapes and sizes, and to steering wheels of various dimensions and configurations. It is another object of the invention to provide a hydraulic system bleed device that uses quick connect type fittings to facilitate placement and removal. It is another object of the present invention to provide a hydraulic system bleed device that is easily pressurized by one person located outside of a vehicle.  
         [0008]     Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. 
     
    
     DRAWINGS  
       [0009]     These and other features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings wherein:  
         [0010]      FIG. 1  is an isometric view of the present invention;  
         [0011]      FIG. 2  is an isometric view of the steering wheel attachment assembly of the present invention  
         [0012]      FIG. 3  is an exploded view of the pedal attachment assembly of the present invention;  
         [0013]      FIG. 4  is a sectional view of the main cylinder of the present invention in an unloaded condition;  
         [0014]      FIG. 5  is a sectional view of the main cylinder of the present invention in a loaded condition.  
         [0015]      FIG. 6  is a partial sectional view of an embodiment of the invention employing an offset J-hook. 
     
    
     DESCRIPTION  
       [0016]     The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.  
         [0017]     Referring now to the drawings in which like reference numbers designate like or corresponding parts throughout the several views, there is shown in  FIG. 1 a  hydraulic system bleed device which is designated generally by the reference number  100 , hydraulic system bleed device (“HSBD”)  100  is comprised of main cylinder  101 , cylinder endcaps  111 , compression lever  104 , outboard extension shaft  103 , inboard extension shaft  105 , nesting extension shaft  104 , steering wheel attachment assembly  109 , and pedal attachment assembly  110 .  
         [0018]     Main cylinder  101  is preferably a hollow, aluminum tube designed to securely accommodate a compression spring (not shown in  FIG. 1 ) used to pressurize a hydraulic system. Main cylinder  101  further includes cylinder end caps  111  which are inserted into the inboard (pedal attachment assembly end) and outboard (steering wheel attachment assembly end) of main cylinder  101 . Bracket  108  extends perpendicularly from the exterior of main cylinder  101  and is located at the outboard end of main cylinder  101 . Lock support  114  extends perpendicularly from the exterior of main cylinder  101  and is located just inboard of the center of main cylinder  101 .  
         [0019]     End caps  111  are preferably constructed from hollow aluminum tube for slidingly receiving inboard extension shaft  102  and outboard extension shaft  103 . End caps  111  have a first outer diameter that is slightly smaller than the inner diameter of main cylinder  101  and extending for a length sufficient to slidingly engage with main cylinder  101 ; a square shoulder rising to a second diameter that is approximately equal to the outer diameter of main cylinder  101 ; and a radiused shoulder that ends in a third inner diameter that is slightly larger than the outer diameter of inboard extension shaft  103  and outboard extension shaft  102 . End caps  111  are fastened to main cylinder  101  by pins, screws, or the like.  
         [0020]     Outboard extension shaft  103  extends from the interior of main cylinder  101  and is connected to wheel attachment assembly  109  by a spring detent, quick-connect, type fitting. As shown in  FIG. 4 , outboard extension shaft  103  includes fitting  610  at its outboard end. Fitting  610  is connected to outboard extension shaft  103  by a pin or screw and includes a reduced diameter section terminating in a full diameter section. Outboard extension shaft  103  is free to move axially within main cylinder  101 . Similarly, inboard extension shaft  102  extends from the interior of main cylinder  101  and moves axially within main cylinder  101 . Inboard extension shaft  102  has an inner diameter that is slighter larger than the outer diameter of nesting extension shaft  104 , allowing nesting extension shaft  104  to slidingly engage, and move axially within and telescope from inboard extension shaft  102 . The amount of engagement of nesting extension shaft  104  within inboard extension shaft  102  is fixable via clamp  106  and locking screw  105 . The inboard end of nesting extension shaft  104  includes a reduced diameter shoulder  607  terminating in a spherical ball  608 . Spherical ball  608  is received by socket  609  and the resulting ball-in-socket connection allows for and accommodates any misalignment between nesting extension shaft  104  and socket  609 . Socket  609  includes a nipple on its outboard end that is received by nesting extension shaft connector  403 .  
         [0021]     Compression lever  1041  is preferably constructed of aluminum tubing and attaches to outboard extension shaft  103  just inboard of fitting  610 . The attachment of compression lever  1041  to outboard extension shaft  103  is preferably a pinned connection perpendicular to the axis of outboard extension shaft  103 . Compression lever  1041  includes a first section  1042  that is approximately the length of main cylinder  101 , and an offset section  1043  that extends from the outboard end of first section  1042  at approximately a  30  degree angle. Offset section  1043  terminates at a connection to outboard extension shaft  103  and includes slot  115  which allows rotation of compression lever  1041  about outboard extension shaft  103 . Link  107  extends between link support  108  and the inboard end of offset section  1043  of compression lever  1041 . Preferably, link  107  is comprised of a pair of flat plates. Link support  108  is comprised of a pair of parallel flanges extending radially from main cylinder  101 . Compression lever  1041  is movable between a first position (as shown in  FIG. 1 ) where first section  1042  is substantially parallel to main cylinder  101  and a second position (as shown in  FIG. 4 ) where second section  1043  is substantially perpendicular to main cylinder  101 .  
         [0022]     Compression lever  1041  further includes trigger support  113  which holds trigger  112  and is positioned to engage lock support  114  when compression lever  1041  is positioned in its first position, substantially parallel to main cylinder  101 . Trigger support  113  is comprised of a pair of parallel flanges separated by a space sufficient to receive trigger  112  and extending radially from compression lever  1041  towards main cylinder  101 . Lock support  114  is likewise comprised of a pair of parallel flanges extending radially from main cylinder  101  towards compression lever  1041  and includes a receiving pin transverse to the parallel plates of lock support  114 . Trigger support  113  and lock support  114  are positioned to be substantially aligned when compression lever  1041  is in its first position. Trigger  112  is connected between the parallel flanges of trigger support  113  through a pinned connection transverse to the parallel plates of trigger support  113 , such that trigger  112  may selectively engage the locking pin included in lock support  114 .  
         [0023]     Referring to  FIG. 2 , an isometric view of the steering wheel attachment assembly  109  is shown. Main beam  301  is preferably constructed of square structural tubing, but may be constructed of other structural shapes that are sufficiently strong and rigid. Center slide  303  slidingly engages main bean  301  and is composed of square structural tubing with an inside height and width slightly larger than the outside height and width of main beam  301 . Once positioned on main beam  301 , lock screw  305  may be tightened to assert a frictional force against main beam  301  that prevents movement of center slide  303  along main beam  301 . Center slide  303  further includes outboard extension shaft connector  311  which is structurally connected, preferably by welding, to center slide  303 . Outboard extension shaft connector  311  is a quick connect fitting that utilizes spring detent  308  to capture outboard extension shaft  103  (not shown) and allow for a rapid and secure connection. A slide  302  is slidably engaged with main beam  301  on both sides of center slide  303 . Each slide  302  includes a two piece clamp  306 . Clamp  306  is composed of two opposed U-shaped retainers that pivot about a pinned connection at the end of the “U” closest to main beam  301 . This connection employs a spring detent  308  which selectively allows pivoting of the U-shaped retainers. The inside, engaging surface of each U-shaped connector is covered by pad  307  which is preferably a foam type pad that accommodates a secure connection to a steering wheel (not shown) without causing damage to the surface of the steering wheel (not shown). Clamp  306  includes clamp connector  312 , which is a quick fit connector that mates with clamp quick connect  313  which is attached to slide  302 . Lock pin  309  is spring loaded and engages with a reduced diameter portion of clamp quick connect  313  to secure clamp  306  to slide  302 . Clamp  306  is positioned to receive a steering wheel (not shown) by retracting spring detent  308 , separating the U-shaped retainers, and moving steering wheel attachment assembly  109  into place. Once positioned, the U-shaped retainers are designed to securely retain a steering wheel (not shown), and the engagement of spring detent  308  prevents movement of the U-shaped retainers.  
         [0024]     Referring to  FIG. 3 , an exploded view of pedal attachment assembly  110  is shown. Pedal attachment assembly  110  is comprised of pedal clamp support  402  and a pair of pedal clamps  401 . Pedal clamp support  402  is preferably rectangular in shape and formed from a metal or structural plastic material. Pedal clamp support  402  includes nesting extension shaft connector  403 , which is a quick-connect type fitting further including spring detent  404 , which is preferably welded to pedal clamp support  402 , or integrally formed into pedal clamp support  402 . Pedal clamp support  402  includes through holes  407  which are transverse to the longitudinal axis of pedal clamp  402  and slidingly receive pedal clamps  401 . Pedal clamps  401  include a pair of parallel legs  407  that slidingly engage pedal clamp support  402  through holes  407 , and an offset section  408  that extends transversely between parallel legs  407  and provides a receiving offset to capture a vehicle pedal (not shown). Pedal clamps  401  are inserted through pedal clamp support  402  in an opposed fashion. Once positioned through pedal clamp support  402 , limit pins  406  are inserted through parallel legs  407  to retain each clamp  401  and limit the sliding travel of parallel legs  407  within pedal clamp support  402 . In operation, pedal clamps  401  are extended to the limit of their travel to receive a vehicle pedal (not shown). Once the vehicle pedal is received, each clamp  401  is slid inward to capture a vehicle pedal. Once captured, lock screws  405  are tightened to prevent any further movement of clamps  401 .  
         [0025]     Each pair of clamps  306  are moveable from a first position (not shown)  
         [0026]     Referring to  FIG. 4 , a sectional view of HBSD  100  in the unloaded condition is shown. Compression lever  1041  is shown in its second position. In this position, outboard extension shaft  103  is primarily disposed within main cylinder  101 . Spring  601  is unloaded (not compressed) and is disposed between spring stop and shaft guide  604  which is internal to main cylinder  101  and positioned proximate to the outboard end of main cylinder  101 , and spring disc  603  which is connected to the outboard end of inboard extension shaft  102 . The axial alignment of outboard extension shaft  103  within main cylinder  101  is maintained by spring stop and shaft guide  604  and the axial alignment of inboard extension shaft  102  is maintained by bearing  602  which is disposed interior to main cylinder  101  and located proximate to the inboard end of main cylinder  101 . Inboard extension shaft spring  605  is disposed within inboard extension shaft  102  between spring stop  606  and the outboard end of nesting extension shaft  104 . Distance A is the distance from a vehicle&#39;s steering wheel to a vehicle&#39;s brake pedal.  
         [0027]     Referring to  FIG. 5 , a sectional view of HBSD  100  in the loaded condition is shown. Compression lever  1041  is shown in its first position and trigger  112  is engaged with trigger lock  114 . In this position, outboard extension shaft  103  is primarily disposed without main cylinder  101 . Because distance A is substantially constant, the extension of outboard extension shaft outboard from main cylinder  101  causes main cylinder  101  to move inboard and spring  601  is compressed between shaft guide and spring stop  604  and spring disc  603  and spring  605  is compressed between spring stop  606  and the outboard end of nesting extension shaft  104 . The combined loading of spring  601  and spring  605  provides an urging force against pedal attachment assembly  110  that pressurizes a vehicle&#39;s hydraulic system.  
         [0028]     Referring to  FIG. 6 , an alternative embodiment of the present invention is shown. In this embodiment, steering wheel attachment assembly  109  is offset from main cylinder  101  by J-hook  620  and offset slide  621 . Offset slide  621  includes a recess  622  adapted to receive outboard extension shaft  103  and passageway  623  adapted to slidingly engage J-hook  620 . Offset slide  621  further includes a screw lock  105  (not shown) which selectively locks the position of J-hook  620  within offset slide  621 . J-hook  620  is a curved rod substantially in the shape of the letter “J.” The outboard end of J-hook  620  is adapted to receive handle  624  which facilitates position adjustment of J-hook  620  within offset slide  621 . The inboard end of J-hook  620  is adapted to connect to steering wheel attachment assembly  109  through spring detent quick connect  625 . This embodiment allows for additional compensation in effective overall length of HBSD  100  (through the positioning of J-hook  620  within offset slide  621 ) and additional compensation for alignment between pedal attachment assembly  110  and steering wheel attachment assembly  109 .  
         [0000]     Operation  
         [0029]     HSBD  100  allows for the positive, secure but adjustable, connection between a vehicle&#39;s steering wheel and brake pedal and provides a simple mechanism whereby a single person can pressurize a hydraulic system to effectuate the process of bleeding air entrained in that hydraulic system. In operation, steering wheel attachment assembly  109  and pedal attachment assembly  110  are first attached to a vehicle&#39;s steering wheel and brake pedal, respectively.  
         [0030]     Once the steering wheel attachment assembly is positioned, lock screws  305  are tightened to secure and fix the position of slides  302  and center slide  303 . Pedal attachment assembly  110  is connected to the appropriate pedal by loosening pedal clamp locks  405 , extending pedal clamps  401  to the limit of their travel, positioning pedal clamps  401  around the pedal selected, retracting pedal clamps  401  into pedal clamp support  402  until the selected pedal has been securely engaged, and tightening pedal clamp locks  405 .  
         [0031]     Following placement and positioning of steering wheel attachment assembly  109  and pedal attachment assembly  110 , HSBD  100  is connected between steering wheel attachment assembly  109  and pedal attachment assembly  110  in the unloaded condition as shown in  FIG. 4 . Although length A is approximately constant for a given vehicle, it will vary between vehicles. To accommodate this difference, lock screw  105  may be loosened to allow movement of nesting extension shaft  104  within inboard extension shaft  102  to allow placement of HSBD  100  with spring  601  in an unloaded condition. Alternatively, lock screw  105  controlling movement of J-hook  620  within offset slide  621  may be loosened to allow inboard/outboard movement of J-hook  620 . Once HSBD  100  is positioned, lock screw  105  is tightened, fixing the telescoped length of nesting extension shaft  104  and/or the final positioning of J-hook  620 . Preferably, HSBD is positioned with compression lever  1041  extending outward from a vehicle steering wheel towards a vehicle driver door, thereby allowing a technician external to the vehicle to easily reach compression lever  1041 . The technician then moves compression lever  1041  to its second position and secures trigger  112  to trigger lock  114 . Spring  601  is now loaded and applies an urging force against a captured vehicle pedal.  
         [0032]     Although the illustrative embodiments of the present invention have been described herein with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various other changes and modifications may be affected by one skilled in the art without departing form the scope or spirit of the invention. All such changes and modifications are intended to be included within the scope of the invention as defined by the appended claims.