Abstract:
A manifold assembly and method of making the same is disclosed. The manifold assembly is preferably made of a polymer. A mold is used to make the manifold portion of the manifold assembly such that small diameter passageways and valve seats are formed enabling use of small solenoids. Since pressure is applied to small diameter plunger seals (valves) driven by solenoid plungers, small solenoids may be used because the force on the solenoid plungers is correspondingly low. The manifold assembly is comprised of a manifold portion and a plug portion. The manifold portion, as disclosed, has an inlet port for the supply of air pressure. An inlet housing in which an inlet solenoid is housed, a supply port for supplying air to or exhausting air from a reservoir, and an exhaust housing in which an exhaust solenoid is housed are connected to a chamber. The chamber which interconnects the housings and supply port is enclosed by the plug portion which is ultrasonically welded to the manifold portion.

Description:
FIELD OF THE INVENTION 
     The invention is a manifold assembly and the method of making it. One use of the manifold assembly is to control the height of a truck&#39;s seat. The manifold assembly may be used in many other instances where small solenoids are employed in the manifold assembly. 
     BACKGROUND OF THE INVENTION 
     Small solenoids produce small plunger forces. Small solenoids may be used in a manifold where low forces are applied to the plungers or to plunger seals attached to the plungers. Pressure applied to a surface area results in a force on that surface. Therefore, it is desirable in the design of manifolds to minimize the area of the plunger seal upon which pressure is applied. Plunger seals attached to solenoid plungers are used to control the flow of gas or other fluid through orifices (having cross-sectional areas) in manifolds. 
     Manifolds are generally molded in one piece and usually require machining. One piece molded manifolds require a longitudinal pin and multiple transverse pins to be used as part of the mold. The transverse pins are attached to the longitudinal pins and it is these transverse pins which form the passageways and orifices in the manifold through which fluid/gas flows. Small orifices are closed with small plunger seals having small surface areas. Since pressure is applied to these small plunger seal surface areas, the operators (i.e., solenoids) driving the plunger seals do not have to be very large to resist the forces applied to the plunger seals. Pins in a one piece mold are difficult to positionally control and they can be damaged by the incoming polymeric material which is injected under high pressure and high velocity. 
     The instant invention solves the aforementioned problems. 
     SUMMARY OF THE INVENTION 
     A manifold assembly is disclosed having two portions, a manifold portion and a plug portion ultrasonically welded together. Sometimes herein just the word manifold may be used to denote the manifold assembly. A multiple piece mold is used to form the manifold portion such that small orifices and passageways are formed which are subject to process pressure. By reducing the cross-sectional area of the orifices, forces on the plunger seals attached to solenoid plungers are reduced enabling the use of smaller operators (i.e. solenoids). 
     The manifold assembly comprises a body having an inlet port, an inlet housing, a supply port, an exhaust housing, and a chamber. The chamber interconnects the inlet housing, the supply port, and the exhaust housing. The inlet port is interconnected by a first passageway with the inlet housing. The inlet housing is interconnected by a second passageway to the chamber. The exhaust port is also interconnected by a third passageway to the chamber. The exhaust port is interconnected by a fourth passageway to the atmosphere external to the manifold. The chamber is formed by a plug portion ultrasonically welded to the manifold portion of the manifold assembly. 
     An inlet solenoid with a first plunger seal resides in the inlet housing and an exhaust solenoid with a second plunger seal resides in the exhaust housing. The inlet housing includes a first valve seat and the exhaust housing includes a second valve seat. The first plunger seal acts and seals against the first valve seat. The second plunger seal acts and seals against the second valve seat. The second passageway interconnects the chamber and the inlet housing and a third passageway interconnects the chamber and the exhaust housing. 
     A first tube connector is affixed to the inlet port and a second tube connector is affixed to the supply port. The tube connectors are inserted in the manifold portion prior to the complete cooling of the manifold portion after it is removed from the mold. This enables easy assembly of the tubes to the manifold. The supply port supplies air or other fluid to a reservoir. When air or other fluid is removed from the reservoir, it flows through the supply port and through the chamber, through the third passageway, through the exhaust housing past the second valve and through the fourth passageway to atmosphere. Preferably the manifold body and the plug are made from an acetal resin sold under the trademark Delrin® which is registered to E. I. DuPont de Nemours. 
     Preferably each of the aforementioned second and fourth passageways have a length to diameter ratio less than 4. Specifically it is desired that the length-diameter ratio of each of the second and fourth passageways between the inlet housing and the chamber and between the exhaust housing and the exterior of the manifold be less than 4. 
     The inlet housing and the exhaust housing each include a valve seat. Concentric with these valve seats are the aforementioned second and fourth passageways. These passageways have a small diameter which enables the use of a small solenoid in the respective housings. A small solenoid may be used because the pressures are applied to a small plunger seal area resulting in a relatively small force which must be overcome by the respective solenoid. The small diameter passageways and orifices are made by a process for making the manifold portion. 
     The manifold assembly is manufactured from two parts, a manifold portion and a plug portion ultrasonically welded together. A multiple piece mold is employed to make the manifold portion of the manifold assembly. 
     A bottom mold portion, a top mold portion, a first rotatable mold portion, a second rotatable mold portion, an inlet mold portion, a right slide portion, and a left slide portion are secured together and form a cavity therein. The bottom mold portion and the top mold portion are in contact in one place. The bottom mold portion contacts the first rotatable mold portion forming: (1) the first passageway interconnecting the inlet port and the inlet housing; and, (2) a second passageway interconnecting the inlet housing and the chamber. The bottom mold portion contacts the second rotatable mold portion forming: (1) the third passageway interconnecting the chamber and the exhaust housing; and, (2) a fourth passageway interconnecting the exhaust housing and the atmosphere external to the manifold. Once the mold is secured together a polymer is injected into the cavity. The polymer, once injected, is then allowed to partially cool. The rotatable mold portions are removed by rotating them and then the top portion of the mold is removed. The rotatable mold portions must be rotated because threads are formed in the inlet housing and exhaust housing therearound during the molding process. The right and left slide portions separate. The top and bottom portions of the mold are then removed. 
     While the injected polymer is still very warm and has not yet taken its final room temperature size and shape, the plug portion is ultrasonically welded to the manifold portion enclosing the chamber which creates the manifold assembly. 
     It is an object of the present invention to provide a manifold assembly having valve seats in solenoid housings with concentric passageways therethrough having small diameters. 
     It is a further object of the present invention to provide a manifold assembly having eccentric passageways connecting into or out of the solenoid housing cavities. 
     It is a further object of the present invention to provide a manifold assembly manufactured by ultrasonically welding two pieces together, a manifold portion and a plug portion. 
     It is a further object of the present invention to provide a manifold assembly having at least one tube connector secured therein. 
     It is a further object of the present invention to provide a manifold assembly having at least one barbed end connector integral therewith. 
     It is a further object of the present invention to provide a manifold assembly which uses small, low power solenoids for closing orifices in the manifold. 
     It is a further object of the present invention to provide a manifold assembly which employs passageways having a length to diameter ratio less than or equal to 4. 
     Further objects of the invention will be understood when reference is made to the Brief Description of the Drawings, the Description of the Invention, and the Claims which follow hereinbelow. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a top plan view of the manifold portion of the manifold assembly. 
     FIG. 2 is a cross-sectional view of a portion of the manifold portion of the manifold assembly taken along the lines  2 — 2  of FIG.  1 . 
     FIG. 3 is a cross-sectional view of the manifold portion of the manifold assembly taken along the lines  3 — 3  of FIG.  1 . 
     FIG. 3A is an enlarged view of a portion of FIG. 3 illustrating a passageway and a valve seat. FIG. 3A also illustrates the relationship between the length and diameter of the passageway. 
     FIG. 4 is a view of the manifold portion of the manifold assembly looking from the air inlet or, put another way, this view is a front view of the manifold portion of the manifold assembly. 
     FIG. 5 is a side view of the manifold portion of the manifold assembly. 
     FIG. 6 is a cross-sectional view of the manifold portion of the manifold assembly taken along the lines  6 — 6  of FIG.  1 . 
     FIG. 7 is a bottom view of the manifold portion of the manifold assembly. 
     FIG. 8 is a cross-sectional view of the manifold portion of the manifold assembly taken along the lines  8 — 8  of FIG.  5 . 
     FIG. 9 is a perspective view of the manifold portion of the manifold assembly. 
     FIG. 10 is a cross-sectional view of the exhaust housing of the manifold portion of the manifold assembly taken along the lines  10 — 10  of FIG.  1 . 
     FIG. 11 is a top view of the plug portion of the manifold assembly. 
     FIG. 12 is a cross-sectional view of the plug portion of the manifold assembly taken along the lines  12 — 12  of FIG.  11 . 
     FIG. 13 is a cross-sectional view of the plug portion of the manifold assembly ultrasonically welded to the manifold portion of the manifold assembly. Solenoids are shown in elevation (i.e., not in cross-section) in the inlet and exhaust housings illustrating the interconnection of the inlet port and the chamber and the supply of air to the supply port. FIG. 13 illustrates the inlet solenoid valve in the open position and the exhaust solenoid valve in the closed position. 
     FIG. 13A is a cross-sectional view of the manifold portion of the manifold assembly ultrasonically welded to the plug portion of the manifold assembly. Solenoids are shown in elevation (i.e., not in cross-section) in the inlet and exhaust housings illustrating the exhaust of air from the supply port to the atmosphere. FIG. 13A illustrates the inlet solenoid valve in the closed position and the exhaust solenoid valve in the open position. 
     FIG. 13B is a cross-sectional view of the manifold assembly ultrasonically welded to the plug portion of the manifold assembly. Solenoids are shown in elevation (i.e., not in cross-section) in the inlet and exhaust housings illustrating both the inlet solenoid valve and the exhaust solenoid valve in the closed position. 
     FIG. 13C is a cross-sectional view similar to FIG. 13 only tube connectors are illustrated in the inlet and supply ports. 
     FIG. 14 is a cross-sectional view of the mold for forming the manifold portion (depicted in FIGS. 1-13) of the manifold assembly. 
     FIG. 15 is a top view of the mold for forming the manifold portion (depicted in FIGS. 1-13) of the manifold assembly. 
     FIG. 16 is a perspective view of the manifold portion of another embodiment of the manifold assembly which includes an inlet connector and a supply connector. 
     FIG. 17 is a cross-sectional view of the manifold portion of the embodiment of FIG. 16 of the manifold assembly. 
     FIG. 18 is a cross-sectional view of the manifold portion of the embodiment of FIG. 16 ultrasonically welded to the plug portion. 
     A better understanding of the invention will be had by referring to the Description of the Invention and Claims which follow hereinbelow. 
    
    
     DESCRIPTION OF THE INVENTION 
     FIG. 1 is a top plan view of the manifold portion  100  of the manifold assembly  1300 . See, FIG. 13 which illustrates the manifold assembly in cross-section. Inlet port  101  supplies air from an air pressure source (not shown). The inlet port  101  has a stepped bore having stepped portions  123 ,  124 ,  125 , and  126 . See, FIGS. 3 and 13. Structural ribs  102 ,  103 , and  104  provide strength to the manifold assembly. See, FIG.  1 . Bolt holes  105  and  106  secure the manifold assembly  1300  to a frame. The particular manifold assembly illustrated in the drawings may be used in connection with raising and lowering of a seat in a truck. Other uses will be apparent to those skilled in the art. Many housings may be employed in other embodiments of the invention. 
     The supply port  118  supplies air to a reservoir (not shown). Similarly the supply port  118  may exhaust air from the reservoir. The supply port  118  to the reservoir comprises a bore having stepped portions  119 ,  120 ,  121  and  122  best viewed in FIGS. 3 and 13. FIG. 3 is a cross-sectional view of the manifold portion taken along the lines  3 — 3  of FIG.  1 . Referring to FIGS. 1 and 3, reference numeral  127  represents the upper portion of the chamber  301 . Still referring to FIGS. 1 and 3, inlet solenoid housing  107  and exhaust solenoid housing  108  are illustrated. Reference numeral  114  indicates threads on the inlet solenoid housing  107  and reference numeral  15  indicates threads on the exhaust solenoid housing  108 . First air passageway  109  supplies air from the inlet port  101  to the inlet solenoid housing  107 . Valve seat  110  on inlet solenoid housing  107  is illustrated best in FIG.  3 . 
     Valve seat  112  in the exhaust solenoid housing  108  is best illustrated in FIG.  3 . Third air passageway  113  interconnects chamber  301  to the exhaust solenoid housing  108 . 
     Second air passageway  111  interconnects the inlet solenoid housing  107  with the chamber  301 . Exhaust solenoid housing  108  is interconnected to the atmosphere external to the manifold by fourth air passageway  116 . Both of these passageways  111 ,  116  have small length to diameter ratios. Preferably these length to diameter ratios are less than or equal to 4. The diameter that is referred to in this discussion is the minimum diameter of the passageways  111 ,  116  illustrated in FIG. 3 at the points where the passageway extends up to the valve seats  110  and  112 . The length that is meant in this discussion is the length from the opening of the passageways (at the valve seats) to the point where the opening extends into either the chamber  301  (in the case of second passageway  111 ) or to the atmosphere (in the case of fourth passageway  116 ). FIG. 3A is an enlarged view of a portion of FIG.  3 . FIG. 3A illustrates the diameter  310  of the second passageway  111  and reference numeral  311  illustrates the length of the second passageway  111 . The diameter  310  is desirably 0.031 inches. Reference numeral  117  as indicated in the various drawing figures refers to the body of the manifold portion  100 . 
     Referring to FIG. 3 reservoir  128  is illustrated as an annular volume about the valve seat  110  in inlet solenoid housing  107 . Reservoir  129  is similarly illustrated as an annular volume about the valve seat  112  in the exhaust solenoid housing  108 . 
     FIG. 2 is a cross-sectional view of the manifold portion taken along the lines  2 — 2  of FIG.  1 . FIG. 2 is an enlarged view. It will be noted that FIG. 2 is a cross-sectional view of a portion of the manifold portion taken along the lines  2 — 2  of FIG.  1 . FIG. 2 provides a good view of the valve seat  110  and the passageway  111  from the inlet solenoid housing to the chamber  301 . Chamber  301  is closed by the plug  1101  as viewed in FIG. 11 when the plug  1101  is ultrasonically welded to the manifold portion. 
     FIG. 11 is a top view of the plug and FIG. 12 is a cross-sectional view of the plug  1101  taken along the lines  12 — 12  of FIG.  11 . FIG. 13 illustrates the plug  1101  welded to the manifold portion  100 . 
     FIG. 13 is a cross-sectional view of the manifold assembly  1300  illustrating the plug portion  1101  ultrasonically welded to the manifold portion  100 . Reference numeral  1301  indicates ultrasonic welding. Ultrasonic welding occurs between the interfering surfaces of the plug portion  1101  and the manifold portion  100 . The ultrasonic welding occurs uniformly around the rectangular forms of plug  1101  and entirely seals chamber  301 . Chamber  301  in FIG. 13 is completely enclosed whereas in FIG. 3 chamber  301  is not enclosed. FIG. 3 does not represent the total assembly. FIG. 13 illustrates solenoids  304 ,  305  shown in elevation in the inlet and exhaust housings. FIG. 13 illustrates the exhaust solenoid having a valve  307  in closed position to seat upon valve seat  112 . Valve  306  on inlet solenoid  304  is in open position to permit air flow through inlet port  101 , first passageway  109 , inlet housing  107 , second air passageway  111 , chamber  301  and through supply port  118 . 
     FIG. 13A is a cross-sectional view of the manifold assembly of FIG. 3 with solenoids  304 ,  305  shown in elevation in the inlet and exhaust housing  107 ,  108  illustrating the exhaust of air from the supply port  118  to the atmosphere. In FIG. 13A, valve  307  is shown in its open position permitting air or other fluid flow from supply port  118  through chamber  301 , third passageway  113  and fourth passageway  116 . FIG. 13A illustrates valve  306  engaging valve seat  110 . Valve  306  is exposed to system pressure but only has to overcome a small force due to the small area of the valve exposed. 
     FIG. 13B illustrates the manifold assembly in the condition where both valves  306 ,  307  are closed against the pressure in chamber  301 . Valve  306  seats against valve seat  110  and only needs to overcome a small force since the area of the valve exposed to pressure is small. 
     FIG. 3A is an enlarged portion of FIG. 3 illustrating passageway  111  and valve seat  110 . Reference numeral  310  represents the diameter of passageway  111  and reference numeral  311  represents the length of the passageway. It is these dimensions that are referred to when length to diameter ratios are discussed. Particularly it is the ratio of the length as represented by numeral  311  to the diameter as represented by reference numeral  310 . Referring to FIG. 14, when the ratio of length  311  to diameter  310  is 4.0 or less, then pin portions  1407  and  1408  will have the strength and rigidity to withstand the forces generated by both mold injection and clamping pressures, typically at least 10,000 psig and 4000 psig, respectively. 
     Referring to FIG. 12 reference numeral  1102  is a concavity in plug  1101 . Reference numeral  1103  indicates another concavity in plug  1101 . Reference numeral  1105  is a shoulder of the plug  1101 , the side of which is ultrasonically welded to the manifold portion  100  of the manifold assembly  1300 . The side of shoulder  1106  is similarly ultrasonically welded to the manifold portion of the assembly  100 . 
     FIG. 4 is a view of the manifold portion looking from the air inlet or put another way this view is a front view of the manifold portion. Chamber  301  can be viewed looking inwardly through the inlet port  101 . The concentric circular lines within inlet port  101  are radiuses and shoulders as will be understood by those skilled in the art when viewing FIG.  3 . FIG. 5 is a side view of the manifold portion. FIG. 6 is a cross-sectional view of the manifold portion taken along the lines  6 — 6  of FIG.  1 . 
     FIG. 7 is a bottom view of the manifold portion of the assembly. Passageways  109 ,  111 ,  113  and  116  are viewed from the bottom as is chamber  301 . 
     FIG. 8 is a cross-sectional view of the manifold portion taken along the lines  8 — 8  of FIG.  6 . Again, the passageways  109  and  116  can be viewed from FIG.  8 . 
     FIG. 9 is a perspective view of the manifold. Inlet housing  107 , supply port  118 , and exhaust housing  108  are viewed well in FIG.  9 . Valve seats  110  and  112  are also illustrated well in this view. FIG. 10 is a cross-sectional view of the exhaust port of the manifold portion of the assembly taken along the lines  10 — 10  of FIG.  1 . 
     FIG. 14 is a cross-sectional view of the mold forming the manifold portion of the assembly. Reference numeral  1400  indicates the mold generally. The mold is comprised of a bottom core portion  1401 , an inlet portion  1402 , a first rotatable core  1403 , a second rotatable core  1404 , a left-half slide portion  1421  of the mold, a right-half slide portion (not shown), and a top portion  1405 . The mold portions form a cavity  1420  which is filled with plastic to create the manifold portion. The first rotatable core  1403  includes a pin portion  1408  for forming second passageway  111 . The second rotatable core  1404  includes a pin portion  1407  for forming fourth passageway  116 . The bottom core portion  1401  of the mold includes a pin portion  1409  which together with pin portion  1408  of the first rotatable mold  1403  forms second passageway  111  and an opening  1440  which communicates with chamber  301 . The bottom core portion of the mold  1401  includes a pin portion  1411  which together with pin portion  1407  of the second rotatable mold  1404  forms a fourth passageway  116  and an opening  1441  which communicates with the atmosphere external to the manifold assembly. Pin portions  1410  and  1412  form passageways  109  and  113  in the manifold portion of the assembly, respectively. The use of the bottom core portion of the mold in conjunction with the rotatable cores  1403  and  1404  enable the formation of small diameter passageways  111  and  116 . In this way, passageways having a length to diameter ratio of 4.0 or less are formed. This enables the reliable formation of manifold portions of the assembly having small diameter passageways and orifices. This avoids the deficiencies of the prior art where metal rods and pins, having length to diameter ratios of more than 4.0, are used in a one piece mold system. After injection of the polymer in the prior art, the rods and pins are removed through access ports which subsequently have to be filled and sealed. The small in cross-section passageways and orifices create small forces acting upon plunger seals that seat against the valve seats which are formed by this molding process. The plunger seals are, in effect, valves. 
     Rotatable core portions  1403  and  1404  include threads thereon which enable the formation of threads in the molding process. The core portions are rotated away from the molding. This leaves the valve seats, threads, and O-ring sealing surfaces within the solenoid housings free of mold parting line mismatch and/or flash, thereby ensuring proper sealing of the housing when the solenoids are threaded into the housings. 
     Once the mold is assembled together, a polymer is injected into the cavity. The mold is held together by means known in the industry. A polymeric resin such as Delrin® or Celcon® may be used but many other polymers (plastics) may be used. Celcon® is a registered trademark of Celanese Corporation. The molding is then allowed to cool. The rotatable mold portions  1403 ,  1404  are rotated away from the molding and removed therefrom. The inlet mold portion is removed. The left  1421  and right  1530  slide portions of the mold are separated. Finally, the top core portion  1405  and bottom core portion  1401  of the mold are removed. Once the manifold portion is ejected from the mold, a plug  1101  is ultrasonically welded thereto as illustrated in FIG.  13 . 
     FIG. 15 is a top view of the mold for forming the manifold portion (depicted in FIGS. 1-13) of the manifold assembly. Left  1421  and right  1530  slide portions of the mold are separated by pulling (or sliding) them apart. 
     FIG. 16 is a perspective view of the manifold portion  1600  of another embodiment of the manifold assembly which includes an inlet connector  1601  and a supply connector  1602 . Connectors  1601  and  1602  enable flexible tubes to be connected thereto. Connector  1601  includes a passageway  1603  therethrough and connector  1602  includes a passageway  1604  therethrough. These passageways conduct air or fluid therethrough as required by the application of the manifold assembly. Barbs  1605  are on the outer periphery of inlet connector  1601  and function so as to resist extraction of a flexible tube placed over the barbs. Similarly, barbs  1606  are on the outer periphery of supply connector  1602  and function so as to resist extraction of a flexible tube placed over the barbs. FIG. 17 is a cross-sectional view of the manifold portion  1600  of the manifold assembly  1800  illustrated in FIG.  18 . FIG. 18 is a cross-sectional view of the manifold portion of the embodiment of FIG. 16 ultrasonically welded to the plug portion  1801 . 
     The invention has been described herein with specificity. Those skilled in the art will recognize that many changes may be made to the invention without departing from the spirit and scope of the claims which are appended hereto.