WO2004041610A2

WO2004041610A2 - Hydraulic hand brake

Info

Publication number: WO2004041610A2
Application number: PCT/US2003/035083
Authority: WO
Inventors: Richard Daigre; Greg Wampler
Original assignee: White Hydraulics Inc
Current assignee: White Hydraulics Inc
Priority date: 2002-11-04
Filing date: 2003-11-04
Publication date: 2004-05-21
Anticipated expiration: 2005-05-04
Also published as: WO2004041610A8; WO2004041610A3

Abstract

A manual hand brake is disclosed for devices having hydraulic brakes, which hand brake allows the selective disconnection of the brake from the remainder of the device’s braking sysem such that upon the manipulation of a manual brake pump the brakes can be released. This allows the device to be moved without operating the main hydraulic system.

Description

HYDRAULIC HAND BRAKE

Field to Which the Invention Relates This invention relates to a hydraulically operated manual brake pump for a hydraulic actuation mechanism. The brake is particularly useful as a deactivation mechanism for spring applied/pressure release brake disclosed in White U.S. Patent 6,145,635 entitled Spring Brake.

Background of the Invention Hydraulically released and/or applied brakes and clutches are used to control the operation of a torque between a rotating mechanism and another mechanism. One application in respect to brake shafts would be in the wheel drive mechanism for scissorlifts . Another example would be in a hydraulically applied/spring release spool for a mechanism for a winch. In these devices, it is not unusual for a piece of equipment to be moved when the device is not under power. An example of this would be on a scissorlift which has run out of fuel, or when it is desired to load a scissorlift onto a tilt bed truck. To accomplish these ends one needs to either run the main hydraulic systems of such device/or to somehow bypass such control mechanisms in order to allow the desired movement of the device. Summary of the Invention

It is an object of this invention to allow for a simply constructed and flexible manual pump for systems using hydraulic control.

It is an object of this invention to reduce the cost of manual pumps.

It is another object of this invention to provide for a pump using turning processes instead of grinding procedures in the manufacture thereof.

It is a further object of this invention to increase the flexibility of manual pumps.

It is another object of this invention to allow for manual hydraulic pumps to be utilized in more applications.

It is a further object of this invention to allow for a very flexible mechanical pump.

It is another object of this invention to reduce the cost of incorporating wheel brake systems into power application systems.

Other objects and a more complete understanding of the invention may be had by referring to the drawing in which:

Description of the Drawings FIGURE 1 is a cut-away cross-section side view of a hydraulic pump built according to the invention; FIGURE 2 is a cut-away cross-section of the pump like FIG 1 with the bypass lever engaged;

FIGURE 3 is a cut-away cross-sectional view like FIG 2 showing in addition the pump handle at the termination of a manual pumping cycle;

FIGURE 4 is a cut-away view of a hand pump like FIG 1 incorporating a balanced release systems and a lever assisted hand pump;

FIGURE 5 is a partial cross-sectional view of the balanced release of FIG 4; and,

FIGURE 6 is a schematic view of a typical application for the hand pump.

Detailed Description of the Invention The invention of this application relates to a manual pump hydraulic actuation assembly 10. This pump actuation assembly 10 is to be utilized in a operational system utilizing hydraulic pressure to actuate or deactuate a hydraulic mechanism 100.

In the particular embodiment disclosed the hydraulic mechanism 100 includes the spring applied mechanically released brakes 101, 102 of a scissorlift (see fig 5). (An example brake is disclosed in White U.S. Patent 6,145,635, contents of which are included by incorporation.) Its use with other pressure operated devices would also be possible. The pump actuation assembly 10 itself includes a release system 20 and a hand pump 50.

The release system 20 is to allow the selective interconnection of the hand pump 50 to the controlled device. It is preferred that the release in addition selectively disconnects the typical hydraulic control system 110 from the application mechanism 101, 102. This would reduce uncertainty in the hand pump's operation.

In the particular preferred embodiment disclosed, the hydraulic control system 110 includes a pressurized line ill which is selectively interconnected to a source of high pressure by a valve (not shown) . This valve can be a manual valve and/or an automatically operated valve. Upon the selected pressurization of the line 111, the particular application mechanism 110 would release the right and left brakes 101, 102 thus to allow the associated device to rotate unimpeded.

The brake release 20 is located in this line. This preferred release 20 accomplishes two purposes: a) the first purpose is to isolate the hand pump 50 hydraulically from the incoming portion of the line 111; and, b) the second purpose is to automatically disconnect the hand pump from the application mechanism 100 upon the receipt of high pressure on the incoming line 111. The purpose of the hand pump 50 is to selectively pressurize the application mechanism 100 and thus to transfer it to its pressure associated state. It is preferred that this hand pump 10 be physically attached to the device with which it is associated at a physically convenient location, further preferably in a location where the pressurized hydraulic line 111 is run between the main source of fluidic actuating pressure and the application mechanism 100. Thus except for the inclusion of a source 112 of fluid for the hand pump 10, an additional length of hydraulic line would not be necessary.

In the preferred embodiment, it is preferred that the brake release 20 and hand pump 50 be incorporated into a single part so as to simplify its utilization and reduce the cost of adding this feature into devices having hydraulically powered applications. This part is bolted onto a frame or other part of the hydraulic device with which it is to be utilized. (Note that since all three fittings 95, 96, 97 face in a single direction, it is possible to remove the housing 11 from the frame with movement in a single direction without changing the positioning of the lines 111, 112, 113 leading thereto.)

In the preferred embodiment disclosed, the release 20 and hand pump 50 are incorporated in a single housing 11. This housing, substantially rectangular in appearance, includes all of the operative members of the brake assembly. The only interconnections needed are fluidic lines 95 leading to the application mechanism 100, the pressure line from the main operating system 111 and a source of fluid 112 for the hand pump (this is the purpose of the fittings 95, 96, 97, respectively, in FIG 1) . Note that it is preferred that the fitting 97 interconnect to a common tank as the fluid from the line 111 so as to not include different fluid types to the application mechanism 100. This can be either its own separate reservoir or (preferably) the same tank as is used as an external source to pressurize line 111.

The release 20 disclosed is a cartridge-type valve 21. As is appropriate, this cartridge-type valve 21 is selectively movable by a handle 23 between a raised position (FIGS 1 and 4) and an engaged lowered position (FIGS 2 and 3). Preferably the handle 23 to the release mechanism is colored in a relatively neutral color so as to differentiate it from the hand pump 50. In the embodiment disclosed the handle 23 is black and its engaged position is inwards in respect to the body 11 (orientation of the body is not critical although an upward handle positioning is preferred) .

In the released upper position (FIG 1) the release 20 allows for the unfeatured flow of fluid from the incoming line 111 to the application mechanism 100 through fitting 96 and 95. A bumper 24 at the top of the cartridge-type valve 21 aids to absorb any movement of the valve 21 upwards in respect to the housing. (Upon normal operation, the release 20 is forced upwards by the operating pressure in the incoming line 111: no separate biasing spring is necessary.) A rod seal 25 seals the area around the rod from fluid leaks while two static seals 26 next to the rod bushing 27 eliminate fluid loss along the threaded area between the bushing 27 and the housing 11 of the device.

Upon manipulation of the release 20 into its downward condition a face-type seal is formed between the conical mechanical end 27 of the cartridge-type valve 21 and the corresponding tapered shoulder 13 of the housing (FIGS 2, 3). (Note that in the particular embodiment disclosed as the valve rod is hard (steel) while the body is soft (aluminum) the seal is somewhat self-adjusting.) If desired, a separate seal can be incorporated at this location, albeit at the risk of complicating the design of the overall brake assembly 10. Under this condition, it would be preferred to include that the seal into the cartridge-type valve 21 both for simplicity of construction as well as the displacement of same from the pressure control loop when the application mechanism 100 is under the control of the incoming line 111.

Once sealed with the shoulder 13 of the housing, the release mechanism will tend to stay in position until the physical moving of the handle 23 to its upward position (or, in the preferred embodiment disclosed, sufficient time passes that the leakage past the shoulder 13 and the system 100 allows the brakes to revert to their default braked condition. This time should be long enough to accomplish the reason for the manual release of the brake) . This can be by the automatically reapplication of fluidic pressure through the line 111 which application of power would move the cartridge-type valve 21 upwards into its previously described deactivated position.

The hand pump 50 is the main operative member of the brake assembly 10: The selective manipulation of the hand pump will cause fluidic power to the application mechanism 100, thus to selectively manually alter its operating condition between its various unpressurized and pressurized conditions.

The particular hand pump 50 disclosed is a spring loaded rod valve. In this valve's upper position (FIGS 1 and 2) , the rods physical displacement in the cylindrical chamber 52 is limited - the end of the rod 53 extends substantially half the way into such chamber (see FIGS 1 and 2). A spring 57 biases the rod valve 51 in its upward position (coil spring disclosed) . Upon application of physical movement to the rod 53, the movement will reduce the relative volume of the chamber 52 due to the rods extension therein. This creates a pressure differential in the chamber (contrast FIG 3 to FIG 2) . This pressure unseats the one-way valve 58 which is located between the hand pump 50 and the release 20 (separate integral ball check valve disclosed - pressed into its passage through plugged holed 61) . This in turn pressurizes the line 113 leading the the application mechanism 100. Upon release of the rod 53, the rod 53 is moved to its return position by the pressure of the spring 57. This increases the relative volume of the chamber 52 back to its original value. At this time, fluid is pulled through the one-way valve 59 leading from the tank line 112, thus to refill the chamber 52 with a new charge of fluid (again separate integral ball check valve disclosed - pressed into fitting 97) . Upon the further engagement of the rod valve downwards, the process would be repeated with a further volume of pressured^' fluid being sent to the application mech.ani.sm 100. When the volume of pressurized fluid is sufficient, the application mechanism will be actuated to its second, pressurized condition. Due to the use of a displacement rod 53 as a pump, there are no surfaces in the hand pump 50 requiring critical construction. Therefore, no grinding or fine machining is necessary to manufacture same. (Note that the one way valve 58 is press fit from the output fitting 95 side to rest against a slight shoulder 54 thus to hold it in place on pressurization of line 111.)

In the embodiment disclosed, the hand pump 50 is under the control of a protruding handle 60 with a high pressure rod seal 61 and a static seal 62 eliminate the passage of fluid outwardly of the housing 11. The bumpers 64 prevent any substantial damage to either the rod valve 51 or the housing bushing upon its toggling motion. When the handle 60 of the hand pump brake assembly 10 has been energized sufficiently, the device with which the application mechanism 100 is associated can be moved around without the application of its main power source and the pressurization of line 111. Preferably the handle of this pump is colored to a prominent color to differentiate it from the release. In the embodiment disclosed the handle 60 is red and its engaged position is outwards of the body 11.

In the design of the preferred embodiment there are two main operating parameters: 1) that the end of the cartridge-type valve 21 and the shoulder 13 of the housing remain seated under manual or other movement of devices incorporating the application mechanism for the desired length of time; and, 2) that the size of the rod valve 51 in respect to the chamber 52 reflect the appropriateness of building up a sufficient amount of pressure on the application mechanism 100 to cause its operation.

The size of the sealing of the cartridge valve 21 to the shoulder 13 is primarily due to the pressure differential across this face-type seal (which is preferred for simplicity) . This differential should be sufficiently high that shock induced pressure changes do not inadvertently operate the release, which release should occur primarily on the last of pressurization of incoming line 111 or the passage of more than sufficient time to accomplish the task for which the hand pump

10 is incorporated.

In respect to the hand pump 50, the preferred embodiment uses a circular handle 60 to operate the rod 53. The two main operating parameters are thus the size of the diameter of the handle 60 and the diameter of the rod 53. The former is responsible for the application of force from the user from the pump assembly 10, while the latter acts as a force multiplier between this force and the application mechanism 100 so as to allow build-up of pressure sufficiently opera-te such application mechanism 100 - preferably with i multiple but not excessive number of pumps (2-10 desired with 3 or 4 preferred) .

The actuation assembly 10 includes an aluminum body

11 3.9" x 3.9" x 1.9". The release system 20 is spaced 1.75" on center with the hand pump 50. The release system rod has a major diameter of .52". The hand pump 50 has a 1.45" stroke and rod diameter of .27". Both are in cavities 2.97" x .64". The release system 20 and hand pump have handles 23, 60 1.15" in diameter.

The preferred embodiment of the invention disclosed includes the method of manufacture (drilled and tapped) with only one pressure seal formed in the body of the device. Most of the manufacture uses the same drills and taps for multiple operations. As both the release and hand pump have aligned axis of movement mounting is further facilitated. The use of a volumetric pump relieves the necessity of secondary seals. The use of a face seal for the release allows repressurization of the primary hydraulic system to actuate the controlled device. Any installation requiring short term high pressure can be actuated. As all fittings axially align it is possible to install (and remove) the unit with relative ease.

Although the invention has been described in its preferred form with a certain degree of particularity, it is to be understood that modifications can also be made without deviating from the invention. For example a pressure released brake embodiment is disclosed in the preferred embodiment. Other pressurized operated devices could be substituted. For additional example the preferred embodiment of the invention, an intermediate lever could be incorporated in respect to the housing 10 so as to provide the amplification of forces (to operate the pump handle disclosed in FIG 4) while also allowing the relocalization of the position as well as the amount of physical forces necessary to operate the pump from that of the location of the physical housing 11 (shown in representational form in FIG 4) . The rate of multiplication of these handles would vary as appropriate. At higher pressure a balanced release valve might also be appropriate, both might be suitable for higher pressure application mechanisms. An additional example, the spring 57 could be eliminated, allowing a manual upwards motion of the hand pump 10 in addition to the disclosed downward motion.

Other changes can be made without deviating from the invention as hereinafter claimed.

What is claimed is:

Claims

Claim 1. A manual actuator for a pressure operated braking system having a selectively operated pressure line, the actuator comprising a body, said body having an input connection and an output connection and an intermediate volumetric pump cavity, an output valve, said output connection being connected to the selectively operated pressure line through said output valve, an input valve, said input connection being connected to a source of fluid through said input valve, a hand pump, said hand pump having a displacement rod and an operating handle, said displacement rod being in said volumetric pump cavity with said operating handle extending from said body for selective movement of said displacement rod within said volumetric pump cavity, and said selective move pnt transferring fluid from said input connection to said output connection through said input valve and said output valve respectively to cause the manual actuator to operate the pressure operated braking system connected to said output connection.

Claim 2. The manual actuator of claim 1 characterized by the addition of a disconnect valve, and said disconnect valve cutting off the selectively operated pressure line from the braking system.

Claim 3. The manual actuator of claim 2 characterized in that pressurization of the selectively operated pressure line reconnects the selectively operated pressure line to the braking system.

Claim 4. The manual actuator of claim 1 characterized in that said displacement rod has one high pressure seal to said body of said actuator.

Claim 5. The manual actuator of claim 1 characterized by the addition of a bias spring, and said bias spring extending between said displacement rod and said body of said actuator to bias said volumetric pump cavity in a relatively enlarged volume.

Claim 6. The manual actuator of claim 1 characterized in that said displacement rod is a turned rod.

Claim 7. The manual actuator of claim 1 characterized in that said input connection and said output connection both having an axis of connection and said axis of connection being parallel.

Claim 8. The manual actuator of claim 7 characterized in that said displacement rod has a longitudinal axis, and said longitudinal axis being parallel to said axis of connection of said input connection and said output connection.'

Claim 9. The manual actuator of claim 1 characterized in that said input valve is located in said body of said actuator in line with said longitudinal axis of said displacement rod.

Claim 10. The manual actuator of claim 9 characterized in that said output valve is located in said body of said actuator perpendicular to said longitudinal axis of said displacement rod.

Claim 11. The manual actuator of claim 1 characterized in that said manual actuator places the braking system into an off condition.

Claim 12. The manual actuator of claim 2 characterized in that said displacement rod has a longitudinal axis, said disconnect valve has a longitudinal axis, and said two longitudinal axes being parallel.

Claim 13. A manual actuator for a pressure operated braking system having a selectively operated pressure line, the actuator comprising a body, said body having an input connection and an output connection and an intermediate volumetric pump cavity, an output valve, said output connection being connected to the selectively operated pressure line through said output valve, an input valve, said input connection being connected to a source of fluid through said input valve, a hand pump, said hand pump having a displacement rod and an operating handle, said displacement rod being in said volumetric pump cavity with said operating handle extending from said body for selective movement of said displacement rod within said volumetric pump cavity, a bias spring, said bias spring extending between said displacement rod and said body of said actuator to bias said volumetric pump cavity in a relatively enlarged volume, a disconnect valve, said disconnect valve cutting off the selectively operated pressure line from the braking system, pressurization of the selectively operated pressure line reconnecting the selectively operated pressure line to the braking system, and said selective movement transferring fluid from said input connection to said output connection through said input valve and said output valve respectively to allow the manual actuator to operate the pressure operated braking system connected to said output connection.

Claim 14. The manual actuator of claim 13 characterized in that said displacement rod has one high pressure seal to said body of said actuator.

Claim 15. The manual actuator of claim 13 characterized in that said displacement rod is a turned rod.

Claim 16. The manual actuator of claim 13 characterized in that said input connection and said output connection both having an axis of connection and said axis of connection being parallel.

Claim 17. The manual actuator of claim 16 characterized in that said displacement rod having a longitudinal axis, and said longitudinal axis being parallel to said axis of connection of said input connection and said output connection.

Claim 18. The manual actuator of claim 16 characterized in that said input valve is located in said body of said actuator in line with said longitudinal axis of said displacement rod.

Claim 19. The manual actuator of claim 18 characterized in that said output valve is located in said body of said actuator perpendicular to said longitudinal axis of said displacement rod.

Claim 20. The manual actuator of claim 19 characterized in that said manual actuator places the braking system into an off condition.

Claim 21. A method for manufacturing a manual actuator for a pressure operated braking system, said method comprising drilling a hole in a body, said hole having a width and depth and an opening, locating a rod having a diameter and length in said hole with a portion of the rod extending through the opening in the body, sealing the rod to the body at such opening with a high pressure seal, providing and locating an intake valve in the body leading to the hole to form an intake opening and providing and locating an output valve in the body leading to the hole to form an output opening.

Claim 22. The method of claim 21 characterized in that the intake valve is longitudinally aligned with said hole in said body.

Claim 23. The method of claim 21 characterized in that the output valve is substantially perpendicular to the longitudinal axis of said hole in said body.

Claim 24. The method of claim 21 characterized by the additional step of drilling a second hole in said body, said second hole having an inner end and an opening, and locating a second disconnect rod in the second hole.

Claim 25. The method of claim 24 characterized in that the output valve is located between the first and second holes .

Claim 26. A method for manufacturing a manual actuator for a pressure operated braking system, the method comprising drilling and turning the parts of the actuator.