US3114669A - Spacer - Google Patents

Description

Dec. 17, 1963 c. A. HERBST 3,114,559

SPACER Filed Jan. 8, 1960 2 Sheets-Sheet 2 Q f W 16i" )UQ M INVENTOR.

Clarnce 0/. Herafi United States Patent 3,114,669 SPACER Clarence A. Her-list, Park Ridge, 111., assignor to Resinoid Engineering Corporation, a corporation of lllinois Filed Jan. 8, 1960, Ser. No. 2,098 2 Claims. (Cl. 161l65) This invention relates to a spacer for joining two metal bodies in spaced relation and more particularly to an insulating spacer having surfaces for sealing contact with the carburetor and intake manifold of an internal cornbustion engine. This application is a continuation-inpart of my copending application Serial Number 603,577, filed August 13, 1956, now abandoned, which was a division of my copending application Serial No. 342,499,

led March 16, 1953, now US. Patent 2,793,152.

The carburetors of automobile engines are usually made of a brass casting with a lower flange which is intended for fastening to the intake manifold of the engine proper. The manifold is ordinarily a metal casting of iron with an upwardly facing flange having appropriate openings matching those in the lower flange of the carburetor. It is desired that an insulation be provided between the manifold and the carburetor to avoid excessive heat transfer from the engine to the carburetor body. In the past this insulation has been provided by a spacer placed between the flanges on the manifold and carburetor respectively.

Difficulty has been experienced in the past in obtaining an accurate seal between the spacer and the flanges on the manifold and carburetor. Various expedients have been used including the use of soft gaskets on either side of the spacer and also a coating of varnish on the surfaces of the spacer. These attempts to seal the surface were necessary in that the flange surfaces could not be ground to sulficient accuracy in production methods. These flanges were often .005 to .008 concave so that air leakage occurred without the use of a separate sealing medium.

In fastening the carburetor to the intake manifold, the spacer has to resist a considerable compressive force and to maintain this resistive quality throughout the life of the engine. For this reason, a completely resilient spacer having cold flow properties cannot be used.

The principal object of this invention is to provide a one piece spacer of the character described which has compressive resistance combined with compressible sealing surfaces for engaging the flanges of the carburetor and intake manifold of an engine.

A further object is to provide a spacer of the character described which is a chemically bonded sandwich type spacer. A further object is to provide a bonded spacer having a core capable of permanently resisting compression placed on the spacer.

Further advantages, features and objects of the invention will be ascertained from the description to follow and thte accompanying drawings, in which:

FIG. 1 is a diagrammatic broken side elevational view of a spacer of this invention installed between the flanges of an engine carburetor and intake manifold;

FIG. 2 is a perspective view of the spacer of this invention;

FIG. 3 is an exploded side elevational view of the mold plates used to form the spacer of FIG. 2;

FIG. 4 is a side elevational view of the mold of FIG. 3 shown in assembled relation;

FIG. 5 is a vertical sectional view through the mold showing a spacer formed therein and taken through the mold so as to illustrate the aligning means, the pins for forming openings through the spacer and the sprue plugs for admitting material within the cavity of the mold;

FIG. 6 is a top plan view of the sprue plate of the mold taken substantially along line 66 of FIG. 3; and

FIG. 7 is a top plan view of the cavity plate of the mold taken substantially along line 77 in FIG. 3.

While this invention is susceptible of embodiments in many different forms, there is shown in the drawings and will herein be described in detail one specific embodiment, with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the embodiment illustrated. The scope of the invention will be pointed out in the appended claims.

The spacer is diagrammatically illustrated in FIG. 2 and is shown to have four relatively large air and gas vapor passages 19 for permitting the passage of the fuel from the carburetor into the intake manifold of the engine. This spacer is about /2 thick so as to provide adequate heat insulation between the intake manifold and the carburetor. The bolts 11 shown in FIG. 1 pass through corner openings 12 in the spacer to secure the parts together. In appearance, the spacer appears to be a single unit of homogeneous material and only upon close examination can it be ascertained that the core might have been separate from the facing surfaces. In the upper face of the spacer as illustrated, there are five openings 13 which extend only a portion of the depth into the core of the spacer. These openings are left in the spacer as a result of placing the molding material in the mold to form the spacer. This procedure will be defined in detail below.

The fragmentary view of FIG. 1 illustrates the barrel 14 of a carburetor having a lower flange 15 opposed to a flange 16 on the intake manifold 17. The spacer, generally indicated 20, is sandwiched between these flanges. The bolts 11 are pulled tight against the flanges to compress them into the surfaces of the spacer thereetween providing an airtight seal. Any slight irregularities in the surfaces of these flanges are accommodated in the compressible surfaces of the spacer and thus avoid air leakage.

The core of the spacer is preferably made of a thermosetting resin and a filler. This composition is injected into a closed mold internally of the surface sheets which are preferably made of a substantially heat resistant resilient material and a substantially heat resistant fibrous material. These sheets appear to have the character of gaskets prior to being bonded to the core. The material used in the surface sheets is different from the material of the core in order to obtain a composite spacer of the sandwich type in which the surface may have a Rockwell hardness of 10 while the core may have a hardness of 100, both using the L-scale. The thickness of the core should be a minimum in excess of the combined thickness of the surface layers. The surface layers should not ordinarily be more than & thick. The core provides a permanent compression resistant body while the surfaces provide the necessary compressibility to seal against slightly irregular surfaces of carburetor or intake manifold.

As stated above, the core is preferably made of a thermosetting resin and a filler. The core may contain from about 50-80% filler to about 50-20% resin. All percentages given herein are by weight. It is preferred however, that the core contain about 70% filler to about 30% resin. Among the thermosetting resins which are useful are the phenolic resins such as phenol-formaldehyde resins, melamine resins such as melamine formal dehyde resins, urea formaldehyde resins and polyester resins. Suitable fillers are mineral fillers such as powdered limestone, asbestos fibre, ceramic fibre, amorphous silica, powdered mica, glass fibre and mixtures thereof.

3 The preferred resin is the phenol-formaldehyde resin and the preferred filler is asbestos fibre.

The surface sheets are preferably made of a substantially heat resistant resilient or rubbery material and a substantially heat resistant fibrous material. The composition of the surface sheets may range from about 90% rubbery material to about fibrous material to about 50% rubbery material to about 50% fibrous material. The heat resistant rubbery materials are those which are substantially stable up to temperatures of about 250 F. and have an elastic recovery factor of about 95% or better. Examples of such materials are neoprene and natural rubber with neoprene being preferred. The heat resistant fibres used may be cellulose fibre, glass fibre, asbestos fibre and mixtures thereof. Since the sheet material must be relatively soft and flexible compared to the core the composition of the sheet material will be governed to some extent by the flexibility of the fibre. Thus with cellulose fibre, for example, less rubbery material may be used while with glass fiber more rubbery material is desirable. Of the fibres mentioned, cellulose fibre is preferred.

The spacer is formed in a closed mold. This mold includes a sprue plate 21 illustrated in FIGS. 3-7. The sprue plate 21 carries four lugs 22 in the shape of the gas and air passages 10 in the finished spacer. These lugs have a depth to fit into the cavity 32 of the cavity plate 31 and to rest upon the bottom of the cavity. The plates are brought into proper alignment by four corner aligning pins 23 which fit into corresponding bores 33 in the cavity plate. The plates are held together by twelve cap screws 34 extending upwardly through the cavity plate and into the sprue plate 21. When the plates are assembled as in FIGS. 4 and 5, aligning pins 25 meet within the cavity with similar pins 35 in the cavity plate. These pins form the corner openings 12 through the spacer. When assembled, five sprue plugs 26 extend through the sprue plate and into the cavity formed between the plates. These plugs ordinarily extend about half way into the cavity and are used for the purpose of introducing the core material into the mold.

Before the mold plates are assembled in closed relation, a surface sheet 18 having four openings therein corresponding to the gas passages 10, is fitted into the sprue plate and frictionally held in place by fitting over the lugs 22. A similar surface sheet 19 having the same openings is fitted into the cavity of the cavity plate 311 and is held in position by frictionally grasping the guide pins 35. These two surface sheets have other openings as required and sheet 13 has five openings to fit about the sprue plugs 26 so that the'plugs may extend through the sheet 18 into the space between the two sheets. The surface sheets are prepared in a conventional manner by mixing the rubbery material and the fibrous material, calendering the mixture and then heating it to vulcanizing temperatures for a time necessary to vulcanize the rubbery material.

The forming of the spacer is done under hydraulic pressure of about 2000 p.s.i. and at an elevated temperature of about 300 F., this temperature being that at which the thermosetting resins will react. A reservoir containing the core material is supported above the assembled mold on a plurality of posts 2'7 secured in the top surface of the sprue plate 21. The material flows from the reservoir through the sprue plugs 26 into the space between the sheets 13 and 19 and the pressure and temperature employed cause the sheets and core to bond together. The sheets and core in the finished product lose substantially all visible identity and the finished spacer appears to be made of homogeneous material. The compressible qualities of the surface sheets are retained while the core material sets up to a considerably greater hardness. In the finished product, the core provides suificient strength and resistance to compression while the surface sheets, although bonded to the core, provide sealing contact with the flanges described.

Ordinarily it is preferred that the sheet material which is used for the sheets 18 and 19 be from A to thick. The molding material as it is forced into the mold is a plastic clay-like mass. The holes formed in the sheets are located with considerable accuracy and generally are on centers within a tolerance of .O03. The spacers are generally required to pass a test according to automotive standards which require the material to withstand a considerable compression for a period of two hundred hours. By combining the surfac compressibility with the hard core in a single unit, considerable expense has been avoided in the handling of separate parts. Manufacturing assembly of motors has been speeded up in this operation without appreciable increase in the cost of the parts involved. The use of the spacer of this invention has resulted in a considerable savings in the manufacture of the automobile engines.

A specific example of a spacer made in accordance with the present invention used surface sheets of .020 thick and a core material of sufficient thickness to make a combined thickness of /2". The surface sheets comprised a mixture of 50% cellulose fibre and 50% neoprene and the core was a mixture of asbestos fibre and 30% phenol-formaldehyde resin. The materials were chemicaliy bonded together at about 300 F. and under a pressure of 2000 p.s.i. The resultant spacer had a permanent compressive resistance and surface portions which were deformable to seal against slight irregular surfaces. Ordinarily the spacers are made in a range from thick to /2" thick and the surface sheets may be of a thickness range between .020" to .030 with the core being between fifteen to thirty times as thick as the surface sheet.

I claim:

1. A spacer for use between the carburetor and intake manifold of an engine, comprising: a sandwich type gasket having a center core comprising by weight a hardened and compression resistant mixture of about 30% of a phenol-formaldehyde resin and about 70% of asbestos fibre, and a relatively thin and soft surface sheet bonded on each side of the core, each surface sheet comprising by weight a mixture of about 50% neoprene and about 50% cellulose fibre, said core having a Rockwell L-scale hardness of about and said sheets having a Rockwell L-scale hardness of about 10, the core having a thickness in excess of the combined thickness of the surface sheets.

2. The spacer of claim 1 wherein said sheets have a maximum thickness of about inch.

References Cited in the file of this patent UNITED STATES PATENTS 2,399,804 Hills et al. May 7, 1946 2,464,783 Dillehay Mar. 22, 1949 2,694,026 Johnson Nov. 9, 1954 2,698,788 Greenman et al. Jan. 4, 1955 2,750,322 Cooke et al. June 12, 1956

Claims (1)

1. A SPACER FOR USE BETWEEN THE CARBURETOR AND INTAKE MANIFOLD OF AN ENGINE, COMPRISING: A SANWICH TYPE GASKET HAVING A CENTER CORE COMPRISING BY WEIGHT A HARDENED AND COMPRESSION RESISTANT MIXTURE OF ABOUT 30% OF A PHENOL-FORMALDEHYDE RESIN AND ABOUT 70% OF ASBESTOS FIBRE, AND A RELATIVELY THIN AND SOFT SURFACE SHEET BONDED ON EACH SIDE OF THE CORE, EACH SURFACE SHEET COMPRISING BY WEIGHT A MIXTURE OF ABOUT 50% NEOPRENE AND ABOUT 50% CELLULOSE FIBRE, SAID CORE HAVING A ROCKWELL L-SCALE HARDNESS OF ABOUT 100 AND SAID SHEETS HAVING A ROCKWELL L-SCALE HARDNESS OF ABOUT 10, THE CORE HAVING A THICKNESS IN EXCESS OF THE COMBINED THICKNESS OF THE SURFACE SHEETS.

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