US3843759A

US3843759A - Method for producing a reinforced resinous housing

Info

Publication number: US3843759A
Application number: US00000712A
Authority: US
Inventors: D Keeham
Original assignee: Individual
Current assignee: Individual
Priority date: 1970-01-05
Filing date: 1970-01-05
Publication date: 1974-10-22
Anticipated expiration: 1991-10-22

Abstract

The present invention discloses a method of making a reinforced, cured, resinous housing such as a pump housing which has high strength and a high resistance to corrosive and errosive fluids. The method includes the steps of forming an initial housing from a synthetic resin which has an internal portion which is essentially in its finished form and which will be subjected to the action of fluids, and an exterior, with the exterior of the initial housing being in unfinished form. A tensioning member is movably located adjacent or contiguous the exterior of the initial housing and has wall means for receiving and securing portions of an elongated reinforcing member. The elongated reinforcing member is wrapped about the exterior of the initial housing to cover at least a portion thereof and separated portions of the reinforcing member are secured to the wall means of the tensioning member. Thereafter, a force is exerted on the tensioning member to move the same relative to the initial housing to tension the wrapped reinforcing member and after this is accomplished, the wrapped reinforcing member is covered with a resin to finish the exterior of the housing. The resins which are capable of use in the method are quite varied and may be either thermosetting of thermplastic in nature. It has been found in the practice of the present invention that an epoxy resin system works extremely well.

Description

United States Patent 1191 Keeham METHOD FOR PRODUQlljg-A kamroncanaasm HOUSING [76] lnventor: Donald J. Keeham, 31012 Huntington Woods Pky., Bay Village, Ohio 44140 [22] Filed: Jan. 5, 1970 [21] Appl. No.: 712

Primary Examiner-Richard R. Kucia Attorney, Agent, or Firm-Woodling, Krost, Granger & Rust [57 ABSTRACT The present invention discloses a method of making a reinforced, cured, resinous housing such as a pump housing which has high strength and a high resistance to corrosive and errosive fluids. The method includes the steps of forming an initial housing from a synthetic resin which has an internal portion which is essentially in its finished form and which will be subjected to the action of fluids, and an exterior, with the exterior of the initial housing being in unfinished form. A tensioning member is movably located adjacent or contiguous the exterior of the initial housing and has wall means for receiving and securing portions of an elongated reinforcing member. The elongated reinforcing member is wrapped about the exterior of the initial housing to cover at least a portion thereof and'separated portions of the reinforcing member are secured to the wall means of the tensioning member. Thereafter, a force is exerted on the tensioning member to move the same relative to the initial housing to tension the wrapped reinforcing member and after this is accomplished, the wrapped reinforcing member is covered with a resin to finishthe exterior of the housing. The resins which are capable of use in the method are quite varied and may be either thermosetting of thermplastic in nature. It has been found in the practice of the present invention that an epoxy resin system works extremely well.

19 Claims, '13 Drawing lFigures PATENIEBum 22 I974 INVENTOR.

DONALD J. KE'EHA/V PATENIEDBBIZZ m4 3,843,759

sum ear 5 INVENTOR.

' DONALD J. KEEHA/V BY 60%;; mgm-Ym mmmncr 22 m4 3343,1759

SHEEI .3 9F 5 INVENTOR. DONALD J. KEEHAA/ PATENTEDOEI 22 m4 INVENTOR.

00mm .1 KEEHA/V 1 METHOD FOR PRODUCING A REINFORCED RESINOUS HOUSING The method outlined above produces a finished reinforced resinous housing which comprises an initial resinous housing having an internal surface and having an exterior surface. The finished product includes a tensioning member adjacent the initial housing which has wall means and an elongated reinforcing member wrapped about the exterior surface of the initial housing with spaced portions secured by the wall means of the tensioning member. Means are provided which urge the tensioning member relative to the initial housing to maintain a constant tension on the wrapped elongated reinforcing member and a resinous covering is located over the wrapped reinforcing member to secure the same in position and complete the exterior surface of the housing.

The apparatus of the present invention is for the purpose of completing the finished housing after the elongated reinforcing member has been wrapped about the initial housing and includes in combination upper and lower mold parts which form a cavity which has the shape of the finished housing and into which the reinforcing member wrapped initial housing is placed. Ram means are provided in the apparatus for forcing a resinous material into the cavity. A plurality of openings extend into the cavity, preferably through the lower mold part and tensioning pins reside in these openings and at the cavity ends of these pins they are secured respectively to portions of the tensioning member and at their other ends extend exteriorly of the lower mold part. Means are provided for securing all of the tensioning pins together at their ends exterior of the lower mold part and means are then provided forexerting a force on the means which secure the ends of the tensioning pins together to pull the tensioning pins in a direction, which direction is outwardly of the cavity. This serves to move the tensioning member and apply a consistent tension to the wrapped elongated reinforcing member. In the preferred embodiment this tensioning force is exerted as a function of the closing of the mold parts.

The present invention which will be discussed in detail hereinafter relates generally to a reinforced housing or otherstructure which is in substance constructed of a hardenable or curable synthetic resin material either of the thermosetting or thermoplastic type. The invention is particularly adaptable for use in producing shapes which are irregular or in other words which do not follow a definite geometric form. In order to illustrate the unique advantages of the present invention, it will be described in conjunction with a centrifugal pump housing, however, it will be readily appreciated by those skilled in the art that the present invention is v susceptible of much broader application and to this end it might be pointed out (for the sake of examplelit is equally susceptible of use in the production of reinforced housings for valves, which are constructed essentially of hardenable synthetic resin materials.

With the above in mind, it may be said in the pump art, it is the custom that pumps be constructed from a metal because of the unique strength advantages which are realized from practically all metals. One of the considerable disadvantages of metal pumps is evident when the metals are subjected, primarily in the chemical industry, to the highly corrosive and errosive nature of many chemicals, for example, acids and alkalis. Pump manufacturers have attempted to combat these particular problems by constructing the metal pumps of highly sophisticated and expensive combinations of metals, and have in some instances attempted to coat the surfaces of the pumps which are to be subjected to the fluids with non-corroding materials, for example rubbers. In some instances attempts have been made to construct pumps of non-corroding synthetic resinous materials. While the constructions which have included the synthetic resinous materials have been highly advantageous from the standpoint of attack by corrosive fluids, they have essentially met with failure because they have not had sufficient strength to withstand the fluid pressures to which the parts have beensubjected.

The present invention is therefore directed to the method, apparatus and finished product of a reinforced synthetic resinous housing uniquely susceptible for use in the pump industry which enables pump housings to be constructed which have the unique advantages of high corrosive and errosive resistance to the fluids which they are to handle but which also have burst strengths which equal and at times exceed those of metal pump constructions. It had also been found that because of the nature of the synthetic resinous materials, that the efficiencies of these pumps are higher be cause the friction between the fluids and the synthetic resinous materials is less than between fluids and the metal constructions.

Other specific objects will be appreciated from the following detailed description and drawings, which point out the steps of the method of the present invention as well as the construction of the product and the apparatus.

Other objects and a fuller'understanding of this invention may be had by referring to the following description and claims, taken in conjunction with the accompanying drawings, in which:

FIG. I is an elevational view in section of a transfer molding apparatus which is utilized to produce the initial resinous housing; I

FIG. 2 is a bottom plan view of the initial resinous housing removed from the molding apparatus of FIG. 1 and taken generally in the direction of line 2-2 of FIG. ll;

FIG. 3 is an elevational view in section of a mold which is utilized in producing the ring-shaped tensioning member which is utilized in the finished housing construction;

FIG. 4 is a plan view of the mold shown in FIG. 3 and illustrating how a fiberglass reinforcing member is wrapped about the pins prior to introducing the resinous molding material into the mold];

FIG. 5 is a plan view of the finished ring-shaped ten- 'oning member produced in the mold of FIGS. 3 and FIG. 6 is an elevational view of the initial resinous housing which is shown in FIGS. 1 and 2, in full elevation and taken in the direction of the view of FIG. 1 with a layer of resin pre-wetted cloth such as fiberglass adhered thereto and with the ring-shaped tensioning member of FIG. 5 positioned relative thereto;

FIG. '7 is a view similar to FIG. 6 but showing the cloth of FIG. 6 being partially covered by wrapping an elongated reinforcing member such as a fiberglass fiber completely thereabout as shown and intermittently attaching same at spaced portions to the pins which are secured to the tensioning member;

FIG. 8 is a view'similar to FIG. 7 but showing the initial housing in a more complete state of being wrapped by the reinforcing member;

FIG. 9 is a view similar to FIGS. 7 and 8 but showing the reinforcing member completely wrapped about the exterior of the initial housing;

FIG. is an elevational view in section of another transfer molding apparatus showing the initial housing covered as in FIG. 9 and placed in a mold therein which mold is adapted to have injected thereinto a synthetic resinous material which is to cover the wrapped initial housing to produce the final exterior surface of the pump housing;

FIG. 10A is an enlarged view of a portion of FIG. 10;

FIG. 11 is a view taken generally along the line ll--ll of FIG. 10; and,

FIG. 12 is an enlarged elevational view in section showing the threaded connection between the tensioning pins of FIG. 10 and the pins of the tensioning member.

The present invention will be more specifically illustrated in connection with the construction of a double volute housing for a centrifugal pump construction which housing is constructed of a thermosetting, curable, resin composition, in this particular instance specifically an epoxy resin composition which is reinforced in the manner described generally above and which is more specifically described hereinafter.

An initial resinous housing is produced in the apparatus illustrated in FIG. 1 which initial housing 20 is shown removed from the molding apparatus in FIGS. 2 and 6-9. This particular initial housing in its completed form has an interior surface 21 and an unfinished exterior surface 22. The finished interior surface 21 is adapted to be subjected to .the action of fluids which are to be handled by the pump and this surface is the one which the impeller (not shown) of the pump construction rotates adjacent.

The apparatus of FIG. lincludes an upper fixed platen 23 and a lower movable platen 24 which is movably supported by a motive power source which includes a piston 25. Upper and

lower mold parts

26 and 27, respectively, are secured to the upper and lower platens and these mold parts are provided with mold inserts both identified by the reference numeral 29 which are secured in position by threaded members as shown. The apparatus also includes a knock-out plate 31 which has knock-out pins 32 secured thereto which find access to the mold cavity through openings in the lower mold part 27. The purpose of pins 32 is to remove the finally molded part from the mold cavity as will be more fully described hereinafter. A tie rod 34 is secured to the knock-out plate 31 andextends upwardly to terminate in an upper end which has an actuating shoulder 36 secured thereto which in traveling downwardly from the position shown in FIG. I will be in position to strike-a fixed abutment 35. Also included as part of the apparatus is the mechanism for injecting resinous material into the mold cavity and this portion of the apparatus comprises a pressure pot 38 which is adapted to receive and contain the resinous material and a transfer piston 40 which includes a piston rod 42 and a plug 43. Prior to the molding operation, the transfer piston 40 is in raised position from that shown in FIG. I and resinous material is contained in the pot 38 and upon downward movement of the transfer piston the resinous material is injected into the mold cavity by the action of plug 43 injecting the resin into the mold cavity by way of port 41.

The operation of the apparatus is essentially as follows. The lower movable platen 24is in a lowered position from that shown in FIG. I, causing the cavity in both of the

mold parts

26 and 27 to be exposed and a meltable core 44 is placed in position in the lower mold cavity. The meltable core 44 is seen both in the right portion as well as in the left portion of the cavity. The meltable core does not form any essential part of the present invention and is provided for the purpose, which will be appreciated by those skilled in the art, of forming the internal portion of the discharge port 28 of the housing 20 at the right end and at the left end providing for the construction of a wall 39 in the housing 20 which forms the double volute construction. In the event a housing were to be constructed which was not to be of the double volute type, then the wall 39 would be unnecessary, thereby making the core 44 less complicated in its construction. The two

mold parts

26 and 27 are next brought into mating engagement by raising of the piston 25 and with the transfer piston 40 in raised position, resinous material is introduced into the pres sure pot 38 after which the transfer piston is forced downwardly injecting resinous material through port 41 into the mold cavity formed by the upper and

lower mold parts

26 and 27. The resinous material will be described in more detail hereinafter; however, it is sufficient to point out at this time that it includes both the resinous material as well as a catalyst system and the mold parts are kept in mating engagement with each other until the formed housing 20 is of sufficient cured strength to be removed from the

mold parts

26 and 27. The time that the parts are maintained in the mold can vary substantially, depending upon the curing system utilized, which may or may not include the use of heat.

After the initial housing has been sufficiently cured under the conditions set forth hereinabove, the mold parts are separated by lowering the piston 25 which at the same time causes lowering of the tie rod 34 and the attached knock-out plate and knock-out pins. When the piston 25 has been lowered sufficiently in accordance with the construction shown in FIG. I, it will be noted that the shoulder 36 will strike abutment 35 thereby prohibiting further lowering of the tie rod and attached knockout plate and knock-out pins. Further lowering of the piston 25 will thus cause the knock-out pins to urge the finished initial housing 20 from the lower mold cavity, thus aiding in its removal. With the mold parts in open condition, the initial housing 20 with core 44, is removed therefrom and may or may not be curedifurther. The finished initial housing shape is additionally illustrated in FIG. 2 with this view taken generally along the line 22 of FIG. 1. It will be noted in FIG. 2 that the as-formed initial housing includes two bosses 37 which are used for positioning a tensioning ring member 45 which is best shown in FIG. 5.

The next description will be that of the tensioning ring member 45 just previously referred to. In this re gard, FIGS. 3 and 4 illustrate the construction of a mold and somewhat schematically the system used in this construction. In this regard, the mold includes an upper mold part 48 and a lower mold part 49. The

lower mold part 49 and an insert secured thereto provides an annular cavity as shown which conforms to the shape of the finished ring member as seen in the plan view of FIG. 5, and in the bottom of this annular cavity is provided a plurality of hexagonally shaped recesses within which to receive the ends of a plurality of insert pins 47. FIG. 12 shows quite well the construction of each of the insert pins 47 and in this regard it will be seen that three hexagonally shaped shoulders are provided since the part is machined with hexagonal bar stock. The end of the pins 47 are inserted into the cavities as shown in FIG. 3 to position the same. The intermediate shoulder on the insert pins 47 just coincides with the top of the recess and prevents resinous material from traveling down into the recess within which the one end of the pins reside. FIG. 4 demonstrates the initial wrapping of a strand of fiberglass about the ends of the insert pins which are to be imbedded in the finally molded resinous part. After the fiberglass has been wrapped as indicated, resinous material is introduced into the annular cavity in sufficient quantity to produce the molded part and the upper mold part 48 is then brought into closed engagement'with the lower mold part 49. A kick-out'plate 54 and kick-out pins 55 are provided in this construction for the purpose of removing the finally molded part. The resin from which this part is constructed will be discussed in more detail hereinafter; however, it may be of the same material as used in forming the initial housing 20. It will be noted from viewing FIG. 12 that the insert pins 47 are all provided on an interior surface with female threads 53 for a purpose to be described hereinafter.

FIG. 6 shows the next step in the method of the present invention and involves the placing of a layer of woven cloth (for example of fiberglass) which has been pre-wetted with a resinous material. The woven cloth material 58 is suitably cut so as to conveniently form and fit the contours of the exterior of the housing and the generally tacky nature of the resin enables it to be conveniently placed and initially maintained on the exterior surface 22.

FIG. 7 demonstrates the next step in the process of the invention which involves wrapping an elongated reinforcing member 61 which has been previously wetted with a resinous materialabout the exterior surface. As noted in FIG. 7, the discharge port 28 is initially wrapped with the elongated reinforcing member (which may be a fiberglass fiber) and after a short dis tance the reinforcing member is brought down around one of the pins 47 and thereafter passes up around the portion identified as the inlet port 30 of the housing. The reinforcing member is then continued around the inlet port and various of the pins 47 in the manner shown in FIG. 7.

FIG. 8 shows the inital housing more completely wrapped with the elongated reinforcing member and FIG. 9 shows the initial housing as completely wrapped with the reinforcing member.

It should be pointed out at this juncture that the present invention contemplates the step of FIG. 6 to be an alternate step which may or may not be utilized in conjunction with the wrapping of the elongated reinforcing member as shown in FIGS. 7, 8 and 9. In other words, the use of the woven cloth material as in FIG. 6 may or may not be utilized as desired and this will be essentially determined by the ultimate environment within which the housing is to reside.

The materials of construction of the woven cloth material I00 as well as the elongated reinforcing member may be varied substantially; however, some of the preferred materials of construction are fiberglass, metal, graphite, and such synthetic fiber materials as nylon and dacron.

The construction of FIG. 9 is next placed in the transfer molding apparatus of FIG. 10. The transfer molding apparatus of FIG. 10 is in many respects similarto the molding apparatus of FIG. 1; however, some detail will be resorted to in describing this particular construction. In this regard, the apparatus includes upper and

lower platens

67 and 68 respectively, having secured thereto upper and lower molds parts 71 and 72. The mold parts 71 and 72 have been appropriately. machined so as to form the exterior configuration of the finished housing. Mold insert 74 is suitably secured to the lower mold part and an insert 75 is provided to fit within the inlet port 30 as shown. The construction also comprises a plurality of tensioning pins 78 which find access to the mold cavity through openings in the lower mold part 72. The lower ends of the tensioning pins 78 are secured together by means of a tension plate 76 which has a plurality of openings extending therethrough as best seen in FIG. 1 1. Each of the tensioning pins is provided with a reduced diameter portion 97 I and these reduced diameter portions are located laterally in line with pairs of openings for cooperation with the reduced diameter portion of each of the tensioning pins. The large diameter opening of each pair is identified by the reference numeral 82 and the small diameter portion is identified by the reference numeral 83 and as will be noted, each of the

openings

82 and 83 are interconnected. The tension plate 76 is movable back and forth in the direction of 84 shown inFIG. 11 to either lock all of the tensioning pins 78 to. the tension plate 76 when the reduced diameter portions 97 are lo- 'cated in the small diameter portions 83 or to release the tensioning pins 78 from the tension plate 76 when the reduced diameter portions are located in line with the large diameter openings 82. The tensioning pins 78 also perform another function upon opening of the mold parts and this is the same function that is performed by the knock-out pins 32 in the apparatus of FIG. 1. In this particular regard, the lower ends of each of the tensioning pins is secured to a knock-out plate 88 as shown.

The apparatus also comprises what are referred to as tension plate tie rods which are fixedly secured at their lower ends to the tension plate 76 and their upper ends extend through openings in abutments 85 and may travel therethrough freely until the abutments are engaged by stop nuts 86 secured to the tie rods 80. The function of these parts will be described briefly hereinafter.

The apparatus also includes a pressure pot 91 for the reception of resinous material which is to be subsequently injected into the mold cavity as well as a transfer piston which is not shown and which includes a piston rod 93 and a plug 94 which has projections thereon which serve to provide openings for the reception of bolts in a finished flange which is formed on the inlet port of the pump housing.

Briefly, the operation of the apparatus of FIGS. 10 and II is as follows. The lower platen 68 is lowered by means of a motive power piston not shown but similar to piston 25 in the apparatus of FIG. I, so as to separate the upper and lower mold parts 71 and 72. The tension plate 76 is moved to the left in the direction of arrow 84 from the position shown in FIG. 11 so as to disconnect the tensioning pins 78 from the tensioning plate.

The tensioning pins 78 are previously rotatably secured in respective pins 47 by means of the female threads 53 on pins 47 and the male threads on tensioning pins 78 as more clearly shown in the enlarged view of FIG. 12. The pins 78 may be attached to pins 47 prior to the winding operation of FIGS. 7, 8 and 9 if desired. This enables one to have a slightly longer pin to string the reinforcing member around. The attaching of pins 78 to pins 47 may be (as shown) accomplished subsequent to the wrapping operation which is shown completed in FIG. 9. In any event, the wrapped initial housing with the attachedtensioning pin is inserted into the cavity in the lower mold part 72 as shown in FIG. 10. The lower platen 68 with the attached lower mold part is then raised (after moving tension plate 76 back to the right) and brought into closed position as shown in FIG. 10. In the process of raising the lower mold part the stop nuts 86 are caused to engage the abutments 85 which prevents further upward movement of the tie r'ids 80 which by the connection previously described to the tensioning pins 78 causes the tensioning pins to be pulled downwardly through the openings in the lower mold part 72. This in turn causes the pins 47 to be forced downwardly as well as the tensioning ring member 45 which causes the wrapped reinforcing member which is. secured about the plurality of pins 47 to be consistently tensioned.

After this resinous material which is contained within the pressure pot 91 is injected into the mold cavity by bringing the piston rod 93 and plug 94 downwardly from the position shown to its lower-most position which places the protrusions on plug 94 into the position indicated by the finished holes in the inlet port flange.

As will be noted in FIG. 10, the downward pull which is exerted on the pins 47 and tensioning member 45 causes a space 100 to be provided between a side of the tensioning ring member and a portion of the initial housing. .As the resinous material is injectedinto the mold cavity the force exerted thereon causes the mold cavity to be completely .filled with the resin thereby completelycovering the wrapped reinforcing member and also causes the space 100 to be completely filled with resin. FIG. 10 shows the space 100 to be empty for more ease in illustrating the invention; however, it is in fact full of resin as is illustrated in the enlarged view of FIG. 10A. This prevents the ring member 45 from returning and keeps the elongated reinforcing member constantly tensioned. It will be appreciated that other means can be utilized to move the ring member and keep it in position for example by using shims. The part is maintained within the mold cavity for a sufficient time to harden the injected resin and thereafter the mold parts are separated by lowering the lower platen 68 and when the lower platen reaches its lowermost position the tensioning pins 78 act as knock-out pins by a mechanism'similar to that shown in FIG. I but not shown in this Figure and identified in FIG. 1 as the

parts

34, 35 and 36.

After the finished housing is removed from the mold cavity it is placed in an oven for a suitable additional cure and the oven is also raised to a temperature which permits the intricate shape of the meltable core 44 to be melted from the'configuration of the finished housing. This meltable core is preferably constructed of a thermoplastic type resin which has a lower melting temperature than the temperature which would provide any particular damage to or melting of the resinous material from which the finished housing is constructed] The oven is also utilized to give additional cure to the housing.

After this operation is completed, specifically the pump housing is ready for its ultimate use and the pump of course must be assembled by appropriately mounting an impeller appropriately within the confines of the interior surface 21 of the initial housing and the impeller is driven by a shaft which is suitably mounted on bearings which are carried by a back plate not shown which back plate covers the opening into the housing and which is formed by means of the mold insert 74 as seen in FIG. 10.

As mentioned hereinabove, the resins which may be satisfactorily utilized as the materials of construction for both the initial housing which is produced in the apparatus of FIG. 1 and the finished exterior surface as accomplished in the apparatus of FIG. 10, may be quite varied and may be either thermosetting of thermoplastic in nature. They may also contain suitable fillers and- /or reinforcing agents which areinjected into the mold cavities during the molding operation and an example of a reinforcing agent would be chopped fiberglass. The thermosetting resins which have been found to be quite satisfactory are varied with one of the preferred being a commercially available epoxy resin combination. Other thermosetting resins suitable for the purpose are polyesters, phenolics, melamines and urethanes. Examples of suitable thermoplastic resinous materials which can be utilized are polyvinyl chloride and polyvinylidene chloride. The cloth covering 58 which is alternatively utilized in this invention and which is demonstrated in FIG. 6 is preferably pre-wetted with a resinousmaterial which is compatible with the resinous material of the initial housing as well as the resinous material which is utilized to pre-wet the reinforcing member 61 which is shown in FIGS. 7, 8 and 9. The resin utilized for the final finishing of the exterior which is accomplished in the apparatus of FIG. 10, should also be compatible with the resins used in the rest of the housing construction. The resins therefore can be quite varied from the standpoint of the teachings of the present invention; however, in any given housing the basic chemical constitution of all of the resins should be compatible.

The specific pump housing which has been disclosed in the present teaching of one of the preferred embodiments of the present invention is extremely desirable and has an extremely high burst strength. This is particularly true when' the resinous material of construction is a thermosetting epoxy resin and when the elongated reinforcing member utilized is a continuous strand of fiberglass. Fiberglass has a high tensile strength and when wound about the rather inconsistent or odd geometrical shape of the housing and then consistently tensioned by the present method, the relatively low strength of the plastic or resinous material is enhanced by the fiberglass material. By the same token the fiberglass is completely covered or contained between the exterior of the initial housing and the finished exterior coating of resin and is not subject to the action of fluids handled by the pump. The portion of the housing which is exposed to the action of errosive and corrosive fluids in the interior surface of the initial housing and is comprised of the basic resin utilized.

For the purpose of further describing a suitable resin formulation to enable those skilled in the art to adequately practice the invention, one may use for forming the initial housing 20 of FIG. 1 an epoxy resin which comprises a diglycidyl ether of Bisphenol PA which includes 2 parts per 100 of resin of a hardener (or catalyst) of imidazole. Also included as part of the formulation is 25 parts per 100 of hexahydrophthalic anhydride and 0.5 parts per 100 of stannous octate. Also included as part of the formulation is 1% parts by weight of ground carbon to one part of resin and hardener.

A satisfactory resin formulation of the final molding step which is shown in FIG. comprises an epoxy resin of a diglycidyl ether of Bisphenol PA with 2 parts per 100 of resin of a hardener of imidazole. 25 parts per 100 of a polyamide is added and 0.5 parts per 100 of stannous octate is added. To this formulation is added a 50 percent by weight of chopped fiberglass fibers.

As a result, the objects of the present invention are uniquely accomplished in that the corrosion and errosion resistant qualities of the appropriate resin are utilized while the high strength characteristics are attained by the wrapping and appropriate winding and tensioning of the elongated reinforcing member which has high strength characteristics.

Although this invention has been described in its preferred form and preferred practice with a certain degree of particularity, it is understood that the present disclosure of the preferred form and preferred practice has been made only by way of example and that numerous changes in the details of construction and the combination and arrangement of parts and steps may be resorted to without departing from the spirit and the scope of the invention as hereinafter claimed.

What is claimed is:

1. The method of making an irregularly shaped, reinforced resinous pump or valve housing having high strength and a high resistance to corrosive fluids including the steps of forming an initial housing from a resin which initial housing has an internal portion and an exterior with the exterior of the initial housing being in unfinished form and having a tensioning member located contiguous to the exterior of the said initial housing and movable relative thereto which tensioning The method as claimed in claim 2, wherein the elongated reinforcing member is pre-wetted with a thermosetting resin.

9. The method as claimed in claim 3, wherein the elongated reinforcing member is pre-wetted with a thermosetting resin.

10. The method as claimed in claim 3, wherein the elongated reinforcing member is pre-wetted with a thermoplastic resin.

11. The method as claimed in claim 3, wherein a layer of woven cloth constructed of said selected material is placed on the exterior of the housing prior to the wrapping of the reinforcing member.

T2. The method as claimed in claim 11, wherein the cloth is pre-wetted with a resin.

T3. The method as claimed in claim 1, wherein the resin is applied to the wrapped reinforcing member by placing the housing and wrapped reinforcing member in a mold and forcing the resin thereinto.

M. The method as claimed in claim 4, wherein the resin from which the initial housing is constructed or the resin covering the wrapped fiberglass may have chopped fiberglass therein.

115. The method as claimed in claim 1, wherein the internal portion of the initial housing is in its finished condition as formed and is the portion to be subjected to corrosive fluids.

16. The method as claimed in claim 1, wherein the wall means of the tensioning member are pins.

member has wall means for receiving and securing porresin is a thermosetting resin.

3. The method as claimed in claim 1, wherein the elongated reinforcing member is selected from the group of materials consisting of metal, graphite, nylon, polyester resin, fiberglass and combinations thereof.

4. The method as claimed in claim 3, wherein the 17. The method as claimed in claim 1, wherein when the tensioning member is moved relative to the housing in exerting a tensioning force on the reinforcing member a space is created between the tensioning member and the initial housing and means. are inserted in the space to prevent return relative movement and untensioning of the reinforcing member.

18. The method as claimed in claim 1, wherein when the tensioning member is moved relative to the housing in exerting a tensioning force on the reinforcing member a space is created between the tensioning member and the initial housing and the resin which covers the wrapped reinforcing member also fills the space preventing return of the tensioning member and untensioning of the reinforcing member.

19. The method as claimed in claim 13, wherein when the tensioning member is moved relative to the housing in exerting a tensioning force on the reinforcing member a space is created between the tensioning member and the initial housing and the resin which covers the wrapped reinforcing member also fills the space preventing return of the tensioning member and untensioning of the reinforcing member.

Claims

1. THE METHOD OF MAKING AN IRREGULARLY SHAPED, REINFORCED RESINOUS PUMP OR VALVE HOUSING HAVING HIGH STRENGTH AND A HIGH RESISTANCE TO CORROSIVE FLUIDS INCLUDING THE STEPS OF FORMING AN INITIAL HOUSING FROM A RESIN WHICH INITAL HOUSING HAS AN INTERNAL PORTION AND AN EXTERIOR WITH THE EXTERIOR OF THE INITIAL HOUSING BEING IN UNFINISHED FORM AND HAVING A TENSIONING MEMBER LOCATED CONTIGUOUS TO THE EXTERIOR OF THE SAID INITIAL HOUSING AND MOVABLE RELATIVE THERETO WHICH TENSIONING MEMBER HAS WALL MEANS FOR RECEIVING AND SECURING PORTIONS OF AN ELONGATED REINFORCING MEMBER, WRAPPING AN ELONGATED REINFORCING MEMBER ABOUT THE EXTERIOR OF THE INITAL HOUSING TO COVER AT LEAST A PORTION THEREOF AND SECURING SEPARATED PORTIONS OF THE REINFORCING MEMBER TO THE WALL MEANS EXERTING A FORCE ON THE TENSIONING MEMBER TO MOVE SAME RELATIVE TO THE HOUSING TO TENSION THE WRAPPED REINFORCING MEMBER, AND THEREAFTER COVERING THE WRAPPED REINFORCING MEMBER WITH A RESIN TO FINISH THE EXTERIOR OF THE HOUSING.

2. The method as claimed in claim 1, wherein the resin is a thermosetting resin.

4. The method as claimed in claim 3, wherein the resin is a thermosetting resin.

5. The method as claimed in claim 3, wherein the resin is a thermoplastic resin.

6. The method as claimed in claim 4, wherein the thermosetting resin is an epoxy resin.

7. The method as claimed in claim 4, wherein the thermosetting resin is selected from the resins consisting of polyesters, phenolics, melamines and urethanes.

8. The method as claimed in claim 2, wherein the elongated reinforcing member is pre-wetted with a thermosetting resin.

12. The method as claimed in claim 11, wherein the cloth is pre-wetted with a resin.

13. The method as claimed in claim 1, wherein the resin is applied to the wrapped reinforcing member by placing the housing and wrapped reinforcing member in a mold and forcing the resin thereinto.

14. The method as claimed in claim 4, wherein the resin from which the initial housing is constructed or the resin covering the wrapped fiberglass may have chopped fiberglass therein.

15. The method as claimed in claim 1, wherein the internal portion of the initial housing is in its finished condition as formed and is the portion to be subjected to corrosive fluids.

17. The method as claimed in claim 1, wherein when the tensioning member is moved relative to the housing in exerting a tensioning force on the reinforcing member a space is created between the tensioning member and the initial housing and means are inserted in the space to prevent return relative movement and untensioning of the reinforcing member.