Abstract:
The present invention is an adjustable fluid friction valve. It is comprised of a left cap, a casing, a right cap, a fluid reservoir, a rotated-member, a stem, and an adjustment grip. The adjustment grip is turned by the user&#39;s hand and connects to and turns the central stem that connects to and turns the rotated-member. The rotated-member communicates fluid flow to different cross-sections of an annular passage that is disposed in the left cap where it is used for variable flow restriction. It is a groove having a varying cross-sectional area along its length with a smaller beginning terminal and a larger concluding terminal. The smaller beginning terminal is blind and the larger concluding terminal communicates with the mid passage of the left cap. The mid passage communicates with the fluid reservoir. The annular passage receives fluid flow from the rotated-member at a cross-section of its length. A smaller cross-section is accompanied by a longer length. Both these conditions increase fluid friction in the valve and have a restricting effect on its fluid flow. A restricted fluid flow increases the force required to push fluid through the valve and any connected external hydraulic circuit, thereby increasing the dampening effect inside the circuit. A grip stopping means is easily added to the grip to stop its rotation in incremental steps.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    Not applicable 
       BACKGROUND 
       [0002]    1. Technical Field 
         [0003]    The present invention relates to a valve that is a hydraulic device for use in conjunction with another hydraulic device having a cylinder and a piston such as a hydraulic cylinder or a hydraulic damper. 
         [0004]    2. Description of the Related Art 
         [0005]    Presently the more advanced hydraulic dampers are adjustable and have a flow control valve disposed within them. This valve uses fluid friction to restrict fluid flow through an internal circuit within the damper. The damper is self-contained in a single housed unit and has an integral grip for the adjustment of its valve. The valve changes the amount of force required to operate the damper. In some instances, the hydraulic damper along with its integral grip must be buried within another machine. The grip becomes inaccessible. The present invention solves this problem by separating the grip from the damper. 
         [0006]    The device described in U.S. Pat. No. 4,591,032 (1986) to Itazu is an example of the present self-contained adjustable hydraulic damper. The internal valve in Itazu&#39;s patent is similar in operation to the external valve in the present invention (see FIGS. 5, 6, and 7 reference numeral 57 of Itazu&#39;s patent,) but the present invention does not require a hollow stem and a hollow rotated-member as Itazu&#39;s device does (see FIG. 5 reference numerals 36 and 44 respectively of Itazu&#39;s patent.) 
         [0007]    The following are other advantages of the present invention: It can be produced economically in small lots because it is made by basic inexpensive machining and manufacturing operations. It can be connected to two dampers at the same time by adding an external check valve to each damper. It has an inexpensive and effective outer seal because the seal is disposed at its low-pressure end. Its annular passage groove is easily milled with a standard woodruff key seat cutter. It has better heat dissipation than one self-contained device because the working fluid of its circuit is exposed to a greater surface area. Its surface area is spread over two devices and two external conduits. 
       SUMMARY 
       [0008]    The object of the present invention is to move the adjustment grip of a hydraulic damper to a separate remote location so that it is easily accessible while leaving the hydraulic damper itself buried within a larger machine. To further understand this new arrangement one must visualize the adjustment grip and its associated parts being stripped and discarded from the present hydraulic damper and a similar adjustment grip and its parts being placed in a separate device remote from the stripped hydraulic damper. This separate device is an adjustable fluid friction valve. The valve has a left and a right port that connects it with a hydraulic circuit that includes the stripped hydraulic damper. 
         [0009]    Accordingly the present invention is an adjustable fluid friction valve for use in a hydraulic circuit and has these items located on the same longitudinal axis: a left cap, a casing, a right cap, a fluid reservoir, a stem, a stem retaining ring, and a grip. The left cap has a single annular passage on one of its internal diameters for the variable restriction of fluid flow. This annular passage is a groove that has a varying cross-sectional area along its length with a smaller beginning terminal and a larger concluding terminal. The smaller beginning terminal is blind and the larger concluding terminal communicates with a mid passage that communicates with the fluid reservoir. The fluid reservoir communicates with a right port that connects to the hydraulic circuit. The opposite end of the hydraulic circuit connects back to the friction valve at its left port that communicates with a bent passage disposed within a rotated-member. The bent passage directs fluid flow to different portions of the annular passage. The rotated-member is rotated around the longitudinal axis and is moved in this rotation by the rotation of the stem. The stem is rotated by the grip and the grip is connected to the stem with a fastening means. 
         [0010]    The grip of the friction valve is adjusted by the user to adjust the force required to produce a desired flow of fluid through the friction valve and the hydraulic circuit. 
     
    
     
       DRAWING FIGURES 
         [0011]    In the description the directions left and right are used to name items. In viewing  FIGS. 1 ,  2 , and  3 , the viewer&#39;s left or right is applied to the appropriately named item. The tilt of the perspective drawings puts the direction (left) towards the lower left corner of the drawing, and the direction (right) towards the upper right corner of the drawing. Only the main item of a standard and well known fastening arrangement is given a reference numeral. 
           [0012]      FIG. 1  is a perspective view showing the complete device connected to fluid conduits. 
           [0013]      FIG. 2  is an exploded perspective view showing the complete device taken apart. 
           [0014]      FIG. 3  is a section taken along line  3 - 3  of  FIG. 1 . 
           [0015]      FIG. 4  is an enlarged view taken along line  4 - 4  of  FIG. 2 . 
           [0016]      FIG. 5  is an enlarged view taken along line  5 - 5  of  FIG. 2 . 
           [0017]      FIG. 6  is an enlarged view taken along line  6 - 6  of  FIG. 2 . 
           [0018]      FIG. 7  is an enlarged view taken along line  7 - 7  of  FIG. 2 . 
           [0019]      FIG. 8  is an enlarged view taken along line  8 - 8  of  FIG. 2 . 
           [0020]      FIG. 9  is an enlarged view taken along line  9 - 9  of  FIG. 2 . 
           [0021]      FIG. 10  is a view taken along line  10 - 10  of  FIG. 9 . 
           [0022]      FIG. 11  is a schematic diagram illustrative of the manner in which the valve is connected to a hydraulic device. 
           [0023]      FIG. 12  is schematic diagram illustrative of the manner in which the depth of the restriction of  FIG. 4  varies annularly. 
       
    
    
     REFERENCE NUMERALS 
       [0000]    
       
           22  friction valve 
           24  right conduit 
           26  hydraulic damper 
           28  left conduit 
           30  left cap 
           32  cap recess 
           34  small portion 
           35  inner seal 
           36  cap recess 
           38  left flange 
           40  rotated-member 
           42  large portion 
           44  pin slot 
           46  left socket 
           50  left port 
           52  passage 
           54  bent passage 
           56  annular passage 
           58  mid passage 
           60  pin 
           64  stem 
           66  reservoir 
           68  casing 
           70  right flange 
           72  right cap 
           74  cap recess 
           76  cap recess 
           78  mark 
           80  ball 
           82  symbols 
           84  spring 
           88  grip 
           92  right socket 
           100  setscrew 
           104  outer seal 
           108  opening 
           110  right port 
           112  retaining ring 
           116   a  grip wing 
           116   b  grip wing 
           118  curve transition 
       
     
         [0065]    Although one skilled in the art would have little trouble making the apparatus from the drawings, the reference-numeral list, and a statement of its use alone, the following text will further describe the apparatus for those without these special skills. 
       DESCRIPTION 
       [0066]    An embodiment of the present invention, friction valve  22 , will be described herein in conjunction with drawing  FIGS. 1-12 . The drawings and the following description include a grip stopping means that is easily added to the device. 
         [0067]    In  FIG. 11 , the friction valve  22  is in a circuit with a hydraulic damper  26 . A left conduit  28  transports fluid from the damper  26  to the valve  22  and a right conduit  24  transports fluid from the valve  22  back to the damper  26  closing the circuit. Damper  26  is similar to a standard damper that is stripped down and therefore is nothing more than a positive displacement hydraulic-piston-pump with a check valve in the piston to keep the fluid flowing in one direction and to make the damper  26  a single acting damper. Either an internal or external spring is included with most dampers to passively return the piston to the end of its passive stroke so the damper is ready for the next active stroke. 
         [0068]    In  FIG. 3 , a single continuous internal fluid passage for the working oil of the friction valve  22  has these segments that in the following order communicate with each other and form a left to right flow path: left port  50 , passage  52 , cap recess  32 , bent passage  54 , annular passage  56 , mid passage  58 , fluid reservoir  66 , cap recess  74 , and right port  110 . 
         [0069]    The friction valve  22  has a longitudinal axis that passes through the central axis of its major parts making them coaxial to the longitudinal axis of the valve. These parts are a left cap  30 , a casing  68 , a right cap  72 , a fluid reservoir  66 , a stem  64 , a stem retaining ring  112 , a grip  88 , and a rotated-member  40 . Each of these parts is made up of mostly cylindrical shapes. (See  FIG. 2 .) 
         [0070]    The valve&#39;s parts are made out of metal with the exception of the grip  88  that is made out of a durable firm plastic and the o-ring seals  35  and  104  that are made out of rubber. 
         [0071]    In  FIG. 3 , the left cap  30  of the friction valve  22  is a single machined piece that is cylindrical in shape with a central axis and has three internal recesses disposed on this central axis. These recesses communicate with each other and are concentric internal bores made in the right face of the left cap  30 . The left most and smallest bore is cap recess  32  that houses the small portion  34  of the rotated-member  40  and forms part of the internal passage. The middle bore houses an inner seal  35  that is a standard o-ring seal. The last bore of the three is cap recess  36  that houses the large portion  42  of the rotated-member  40  and communicates with the fluid reservoir  66 . Disposed on the internal diameter of this bore is a single annular passage  56  for the variable restriction of fluid flow that is a groove having a varying cross-sectional area along its length with a smaller beginning terminal and a larger concluding terminal, the smaller beginning terminal is blind, and the larger concluding terminal communicates with a mid passage  58  that is an axial hole that is drilled into the right face of the left cap  30 . The mid passage  58  communicates with the fluid reservoir  66 . 
         [0072]    The annular passage  56  is made by mill cutting with a standard woodruff key seat-cutting tool in conjunction with a boring mill modified for annular milling. The radius of the cutting tool  118  is shown in  FIG. 4  at the concluding terminal of the annular passage  56 . 
         [0073]    A diagram showing only the usable part of the annular passage  56 , its cross-sectional variation, and the passages it communicates with is shown in  FIG. 12 . 
         [0074]    In  FIG. 3 , the left cap  30  also has the following: (1) an external flange  38  disposed in its outside diameter on its right end to accommodate the left end of casing  68  and to give the external surface of the valve  22  a smooth flush appearance, (2) a small external ring groove (not shown) disposed in the left flange  38  for the left end of the casing  68  to be rolled into for a fluid tight connection between the left cap  30  and the casing  68 , and (3) a left port  50  that is a pipe tapped hole that is disposed in the left cap  30  normal to the longitudinal axis of the friction valve  22  for a fluid tight connection between the left cap  30  and the left conduit  28 . 
         [0075]    Casing  68  is a thin walled tube cut to a predetermined length in order to produce an adequate fluid supply in the fluid reservoir  66 . 
         [0076]    The right cap  72  of the friction valve  22  is a single machined piece that is cylindrical in shape with a central axis that has a cap recess  74  and an opening  108  disposed on this central axis. The recess and the opening communicate with each other and are concentric internal bores. The larger bore that is cap recess  74  is made in the left face of the right cap  72 . It forms part of the internal passage and communicates with the fluid reservoir  66 . The right most and smallest bore that is opening  108  is a through bore made in the right face of right cap  72  to accommodate the stem  64 . The right cap  72  also has the following: (1) an external flange  70  disposed in its outside diameter on its left end to accommodate the right end of casing  68  and to give the external surface of the valve  22  a smooth flush appearance, (2) a small external ring groove (not shown) disposed in the right flange  70  for the right end of the casing  68  to be rolled into for a fluid tight connection between the right cap  72  and the casing  68 , (3) a distinctive mark  78 , that is a recess, that is milled with an end mill in an axial direction at a 45 degree angle to the longitudinal axis of the friction valve  22  in the right outermost rim of the right cap  72 , (4) an appropriate number of the occurrences of the cap recess  76  that is a blind drilled axial hole that is radially disposed in a ring centered around the longitudinal axis of the friction valve  22  (Each hole is drilled into the right face of the right cap  72 ), and (5) a right port  110  that is a pipe tapped hole that is disposed in the right cap  72  normal to the longitudinal axis of the friction valve  22  for a fluid tight connection between the right cap  72  and the right conduit  24 . 
         [0077]    For the radial arrangement of the features of the right cap  72  just described see  FIGS. 7 and 8 . 
         [0078]    In one alternative arrangement, a single friction valve is used with two dampers that have alternating active strokes. Each damper has an isolating check valve on its high-pressure discharge conduit. An additional left port  50  and right port  110  is needed in the friction valve  22  to accommodate the additional damper. In this arrangement the right ports may be modified to go directly into the fluid reservoir  66 . 
         [0079]    In  FIG. 3 , the grip  88  of friction valve  22  is a continuous molding and has a large left cylinder and a small right cylinder that are end joined cylinders on the same central axis of the grip  88 . This central axis also has disposed upon it a coaxial socket  92  that is a recess that is made in the left face of the large cylinder that extends into the small cylinder. This coaxial recess accommodates the right end of stem  64 . The grip  88  additionally has a grip stopping means that stops it incrementally in its rotation around the longitudinal axis of the friction valve  22  with a ball  80  that partially moves into one of the radially disposed recesses  76  of the right cap. The ball is urged by a spring  84 . The spring along with the ball  80  is disposed in a recess that is a blind drilled axial hole in the grip  88 . At different times each of the radially disposed cap recesses  76  line up with the single combined ball and spring recess while the grip  88  is being rotated stopping the grip  88  in increments of rotation. The ball  80  is held in the ball and spring recess by deformities (not shown) made in the open end of the recess by an impact driven deforming tool. The grip  88  also has the following: (1) a fastening means that connects the grip  88  to the stem  64  that is a standard setscrew  100  disposed normal to the longitudinal axis of the friction valve  22  in a threaded opening in one side of the large cylinder of the grip  88 , (2) two grip wings  116   a  and  116   b , for increasing the torque transmitted between the user hand and the grip  88 , that are disposed on the right end of the grip  88  in opposing position to each other, that are a part of the continuous body of the grip  88 , and that are molded into the large and small cylinders of the grip  88 , and (3) a grip position indicator that is a series of sequential symbols  82  that are printed on a flexible adhesive tape that is applied to the outside diameter of the large cylinder of the grip  88  near its left end in opposed position to the distinctive mark  78  of the right cap  72 . 
         [0080]    For the radial arrangement of the features of the grip  88  just described see  FIG. 9 . 
         [0081]    In  FIG. 3 , the stem  64  of the friction valve  22  is a round bar that is the connecting link between the grip  88  and the rotated-member  40 . The three items become a rotating unit within the friction valve. The stem  64  has a pin  60  inserted in a drilled hole disposed in its outside diameter near its left end. The hole is normal to the longitudinal axis of the friction valve  22 . The stem  64  also has the retaining ring  112  that is a standard shafting accessory inserted in an annular groove disposed in its outside diameter near its right end. This ring holds the stem  64  inside the valve  22  when fluid pressure in the left cap urges the rotating unit to the right. The stem  64  finally has an outer seal  104  inserted in an annular groove in its outside diameter near its right end to the right of the retaining ring  112 . This seal is a standard o-ring seal that prevents fluid from leaking from the friction valve  22 ; otherwise, close tolerances and costly fits would be necessary to prevent this leakage. 
         [0082]    For the radial arrangement of the features of the stem  64  just described see  FIG. 6 . 
         [0083]    One alternative that immediately presents itself in regards to the making of the stem  64  is to make it and the rotated-member  40  out of one piece of machined stock and eliminate the connection between these two items to lower the unit cost on high volume production runs of the friction valve. 
         [0084]    In  FIG. 3 , the rotated-member  40  of friction valve  22  is a single machined piece and has a left small portion  34  and a right large portion  42  that are end joined cylinders on the same central axis of the rotated-member  40 . This central axis also has disposed upon it a coaxial recess that is made in the left face of the small portion  34  that extends into the larger portion  42 . This recess is the coaxial portion of a bent passage  54 . The remainder of the bent passage is made of an intersecting hole drilled from the center of the outside diameter of the large portion  42 . The bent passage  54  is for directing and communicating fluid flow to different portions of the annular passage  56 . 
         [0085]    The rotated-member  40  is rotated around the longitudinal axis of the friction valve  22  and is moved in this rotation by the rotation of the stem  64 . The stem  64  is moved in this rotation by the grip  88 . The large portion of the rotated-member  40  has a coaxial recess on its central axis that is the left socket  46  that is a bore made in the right face of the large portion  42  that accommodates the left end of stem  64 . The large portion  42  also has a pin slot  44  in its right face that is a radial slot that has a terminal that communicates with recess  46  and an opposite terminal that is blind. This slot engages pin  60  of the stem  64  and transfers torque from the stem to the rotated-member  40 . 
         [0086]    The small portion  34  of the rotated-member  40  forms a seat for the inner seal  35  that is a standard o-ring seal that prevents fluid from leaking around the rotated-member  40 ; otherwise, close tolerances and costly fits would be necessary to minimize this leakage. 
         [0087]    For the radial arrangement of the features of the rotated-member  40  just described see  FIG. 5 . 
         [0088]    To assemble the friction valve  22 , use  FIG. 3  as a reference, and do as follows: (1) Pick up stem  64  and put pin  90 , retaining ring  112 , and outer seal  104  on it and then insert the stem through the opening  108  of the end cap  72  until its right end is fully extended to make assembly ‘A’. (2) Pick up grip  88  and install spring  84  and ball  80  in their combination recess, install setscrew  100  in its recess, apply the symbol-tape to the outside diameter of the grip, and then put the socket  92  of the grip on the extended right stem end of assembly ‘A’, tighten the setscrew of the grip—Procedure (2) changes assembly ‘A’ to a larger assembly ‘B’. (3) Pick up casing  68  and put it on the flange  70  of assembly ‘B’ and roll this combination in a rolling machine to connect casing  68  to assembly ‘B’—Procedure (3) changes assembly ‘B’ to a larger assembly ‘C’. (4) Pick up rotated-member  40  and put seal  35  on it and put this combination into the recess  36  of cap  30  so that the socket  46  is facing outward—Procedure (4) makes assembly ‘D’. Pick up assembly ‘D’ and insert its flange  38  into the open end of the casing  68  of assembly ‘C’ and roll this combination in a rolling machine to complete the assembly of friction valve  22 . 
         [0089]    The friction valve  22  is operated by turning the grip  88  to one of the symbols  82  on the symbol-tape. The valve has been calibrated so that a grip symbol setting on the symbol-tape gives a predetermined restriction of fluid flow through the valve. 
         [0090]    It was shown in the previous description that: (1) The grip of the damper  26  was separated from the damper so the damper itself could be used in an inaccessible location. (2) The manufacturing set-up costs of the device are low which keeps its selling price low during the initial low volume phase of marketing. (3) In application where two dampers have alternate active strokes one friction valve  22  can be used for their control with addition of more fluid ports. (4) An inexpensive low-pressure seal can be used for the outer seal  104  because the high pressure in the working oil from the active stroke of the damper is dropped across the annular passage  56  that precedes the outer seal in the flow path of the working oil. (5) The annular passage  56  is milled with a standard woodruff key seat cutter eliminating the need for expensive and sophisticated machining methods. 
         [0091]    While we have shown and described an embodiment in accordance with the present invention, it should be clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention.