US2749895A - Vacuum breaker - Google Patents

Description

June 12, 1956 c. R. FLINT 2,74%,8W51

VACUUM BREAKER Filed Oct. 29, 1952 s Sheets-Sheet 1 C. R. FLINT VACUUM BREAKER June 12, 1956 3 Sheets-Sheet 2 Filed Oct. 29

J7? a? for June 12, 1956 c. R. FLINT 2,749,895

VACUUM BREAKER Filed 001?. 29, 1952 3 Sheets-Sheet 5 I a n I VACUUM BREAKER Charles R. Flint, La Porte, Ind., assignor to United Specialties Company, Chicago, 1th, a corporation of Delaware Application Gctoher 29, 1952, Serial No. 317,407

3 Claims. (Cl. 12397) My invention relates to a device to be used with the carburetors on internal combustion engines and has for a primary purpose breaking a vacuum created in the intake manifold of an internal combustion engine and in the idle well of the carburetor.

This is an improvement on the devices shown in my prior patents, Nos. 2,267,020 and 2,453,125, and a discussion of the problems, purposes, and function of the devices shown in those two patents is pertinent to the instant structure. For a discussion of the problems created during deceleration of an internal combustion engine while operating under momentum conditions and the difficulties attendant with such operation, reference is made to those two patents.

A primary object of my invention is a device, commonly termed a vacuum breaker, for relieving or breaking the vacuum created in the intake manifold and in the idle well of an internal combustion engine during momentum conditions.

Another object of my invention is a vacuum breaker adapted to open the intake manifold and break the vacuum created therein when the vacuum has reached a predetermined amount and to close the manifold when the vacuum has been reduced to another predetermined amount.

Other objects will appear from time to time in the ensuing specification and drawings in which:

Figure 1 is a side view of my new, improved vacuum breaker, taken partly in section and broken away;

Figure 2 is a sectional view taken along line 2--2 of Figure 1;

Figure 3 is a sectional view taken along line 33 of Figure 1;

Figure 4 is a detail view of a bearing supporting spider contained in my new, improved vacuum breaker;

Figure 5 is a sectional view taken along line 5-5 of Figure 4;

Figure 6 is a modified form of my invention as a side view taken partly in section and broken away to illustrate various details;

Figure 7 is a sectional view taken along line 77 of Figure 6; and

Figure 8 is a sectional view on a reduced scale of a diaphragm chamber structure positioned on a carburetor idle jet to be used with my vacuum breaker.

In the embodiment of Figures 1 through 5 the vacuum breaker consists primarily of an upper housing 10 and a lower housing 12, these two housings being joined by a circular bracket 34, shown in detail in Figure 2. The upper housing is provided on its lower edge with an extended flange l6, and the lower housing fits partially inside the upper housing and is provided with a circular head 18 which is engaged by the flange 16. When the flange and the bead are in position adjacent each other with a gasket 19 interposed therebetween, the circular bracket 14 is secured around them and is drawn in tightly by an appropriate nut and bolt connection 20, as shown in Figure 2.

The lower end of the lower housing 12 is provided with abottom plate 22 which is secured to a lower flanged 2,749,895 Ca Patented June 12, 1956 edge 24 on the lower housing by a crimped edge 26, a suitable gasket 27 being interposed therebetween to form an air and gas tight connection. The bottom plate is secured to an appropriate fitting 28 by a suitable weld 30 which forms an air and gas tight connection therewith. The fitting 23 is threaded into the intake manifold 32 of an internal combustion engine at any appropriate location.

The upper housing 10 is provided with a top plate 34 which is connected thereto by a crimped edge 36 with an appropriate gasket 37 interposed to form an air and gas tight connection. An air inlet vent 38 is securely welded as at as in air and gas tight relationship in a suitable aperture in the upper housing.

internally positioned within the housings is a vertically disposed, movable shaft 42 which slides or reciprocates in upper and lower bearings 44 and 46, respectively. The upper bearing is supported by and positioned in an upper spider 48 which is circular in contour and is welded to the interior of the upper housing at St). The lower bearing 46 is also held by a similar spider 52 which is appropriately welded to the interior of the lower housing at 54. It should be understood that each of the spiders is formed with a circular outer ring which is connected to the in terior of the housing and a circular inner ring which supports the particular bearing and is connected to the outer ring by at least two radial legs, this structure being shown in Figures 4 and 5.

The lower end of the shaft 42 is provided with a circular, perforate plate 56 which acts as a lower stop for the shaft in its movements. The plate, when the shaft has been moved downwardly, strikes the bottom plate 22 and defines the lowermost position of the shaft.

A valve structure is provided in the lower housing 12 and includes a circular valve seat 58 which is secured to the inside of the lower housing by an appropriate air and gas tight weld 66, so that during the periods the valve is closed air will not move past the valve seat. A valve plate 62, which is circular in contour, is positioned on the lower end of the shaft 42 above the circular stop plate 56 and is retained thereon by a pair of resilient washers 64. The inside diameter of the valve plate is slightly larger than the diameter of the lower end of shaft 42 so that the valve plate will wobble slightly or position itself upon contacting the valve seat 58. The resilient washers 64 accommodate any movement of the valve plate and thus provide for an accurate seating of the plate against a lapped and ground valve surface 66 on the valve seat. The circular stop plate 56, the two resilient washers 64, and the valve plate 62 are retained on the lower end of the shaft 4-2 between a pair of metal washers 63 and '76, the upper washer 625 engaging a shoulder on shaft 42.

It should be noted that the stop plate 56 has an outside diameter slightly less than the inside diameter of the lower housing 12 and is also provided with large perforations or openings therethrough so that it will not constitute a hindrance to the free circulation of air through the lower housing from the valve structure to the intake manifold 32.

The upper end of the shaft 42 is provided with a circular plate 72 which has an outside diameter of slightly less than the inside diameter of the upper housing. This plate is retained on the upper end of the shaft in one of a plurality of positions. The shaft has six circular grooves 74 which are engaged by upper and lower snap rings '76 and 78 which retain between them the circular plate 72 and a washer 80. The total distance between the snap rings due to the intervention of the plate and the washer covers four of the circular grooves on the shaft; consequently, by moving the snap rings from one groove to another the plate can be accurately placed in one of three different positions along the shaft. It should be understood that the shaft may have more or less than six circular grooves 74 so as to provide any number of positions for the circular plate 72.

Mounted on the upper side of the spider 52 is a leaf spring 81 Which engages shaft 42 and acts as a damper or drag against the movements of the shaft so that the same will not vibrate from one position to another during operation of the valve.

A coil spring 82 is positioned around the shaft and engages at its upper end a domed-up portion 84 in the plate 72 and on its lower end the spider 52 supporting the bearing 46. As the spider 52 is stationarily mounted with respect to the housing structure, the spring will force the plate 72 and consequently the shaft 42 and its associated structure upwardly until the valve plate 62 engages the valve surface 66 on the valve seat at which point the spring 82 remains under an amount of compression sulficient to keep the valve closed during various stages of operation.

In the side of the upper housing an appropriate opening 36 is provided with an adaptor 88 which serves as a means of direct communication with a diaphragm chamber structure designated generally 9%) in Figure 8. As shown in this figure, the diaphragm structure includes a two compartment chamber with a separating diaphragm 92 and an aperture 94 in the side of the internal combustion engines carburetor 96, the aperture 94 being in communication with the idle well fuel jet as shown in my prior Patent 2,453,125. One compartment 98 of the chamber structure is in communication with the upper housing 10 through an appropriate tubular connection 100 shown partly in Figure 8 and Figure 1. The other compartment 162 is in communication with the idle well fuel jet through aperture 64, and upon withdrawal of a needle valve 194 air is admitted to the jet through an opening 106, the needle valve 104 being biased closed by a coil spring 107.

The use and operation of this embodiment are as follows:

When the internal combustion engine with which my vacuum breaker is used is subjected to momentum conditions, meaning that the engine is operating under other forces than its own power and at a speed greater than that attained by the carburetor throttle setting, an excessive vacuum will exist in the intake manifold. This vacuum is communicated to the lower end of the housing 12 through fitting 28, and at a predetermined vacuum the valve plate 62 will be moved away from the valve surface 66 on the valve seat 58. The coil spring 82 is preloaded against this vacuum so that the valve structure will open only when subjected to a vacuum of a predetermined amount. It should be understood that prior to the opening of the valve structure the interior of the vacuum breaker above the valve is at atmospheric pressure through the inlet vent 38. The compartment 98 of the diaphragm chamber 90 is also at atmospheric pressure. When the valve structure has been opened and shaft .2 has been lowered somewhat, air is immediately moved from the upper part of the housing past the valve structure into the intake manifold, and the pressure in the upper part of the housing is reduced causing air to move rapidly through the small circular vent defined between the inside of the upper housing 10 and the circular plate '72. This rapid movement of the air past the circular plate 72 causes further depression of the shaft 42 until the circular stop plate 56 engages the bottom plate 22, and the pressure in the housings is greatly reduced. The pressure reduction in the housings will be communicated to the compartment 98 of the diaphragm chamber 90 withdrawing the needle valve 104 from the opening 94, thus admitting air through the opening 106 into the idle well fuel jet.

When the throttle valve of the engine is again opened and the vacuum in the intake manifold falls below a certain value, the coil spring 32 will force the valve plate 62 into engagement with the valve surface 66, thus eliminating the pressure reduction in the upper housing 10 and in the compartment 98 of the diaphragm chamber 90,

and the spring 107 will force the needle valve closed. The amount of vacuum necessary to close the valve structure is far less than that required to open it due to the additional force exerted downwardly on plate 72, once the valve has been opened, by the rapid movement of air through the restricted space defined by the upper housing and circumferential edge of the plate.

It should be understood that the upper housing 10 may be easily removed from the lower housing 12 by the removal of the circular bracket 14, so that the valve structure, the vertical shaft 42, and its associated parts can be exposed for cleaning, maintenance and repair.

In the modification of Figures 6 and 7, the vacuum breaker again consists primarily of an upper housing and a lower housing 122 joined together in the same manner by a circular bracket 124. The lower housing has a fitting 126 which is adapted to be connected to the intake manifold, and the upper housing has an inlet vent 123 which establishes atmospheric pressure in the upper housing above the valve structure. The upper housing also has an appropriate fitting 136 which is connected to a diaphragm chamber structure such as that shown in Figure 8.

The internal valve structure has been modified in this embodiment and consists of a vertically movable shaft 132 which is supported between an upper bearing 134 and a lower bearing 136. Each bearing is supported by an appropriate spider-like ring bracket, the lower bracket 137 consisting of a circular flange portion welded to the lower housing 122 at 138 with at least a pair of legs extending radially inwardly to a bearing supporting ring. The upper spider 139 consists of a bearing supporting ring connected by an appropriate number of legs to a depending skirt 141) welded in air and gas tight relationship to the lower end of the upper housing as at 142.

A valve seat 144 is appropriately welded in air and gas tight relationship to the spider and has a valve surface 146 which is lapped and ground to an appropriate finish. A valve plate 148 is mounted on the shaft 132 between a pair of resilient washers 150 so as to allow for the wobbling movement of the plate as described in connection with the embodiment of Figures 1 through 5. It should be noted that the valve plate 143 extends outwardly so as to provide a small clearance between its circumferential outer edge and the inside of the skirt 140 on the spider 139.

A retaining element 152 is mounted around the shaft 132 and is secured thereto by any appropriate means such as the pin 154. This retaining means has a shoulder 156 against which bears a coil spring 158. The other end of the spring bears against the lower spider, and at all times the spring is under compression so as to bias the shaft 132 upwardly and the valve plate 148 into engagement with the valve seat 144.

This embodiment is also provided with a damping leaf spring 160 mounted on the upper spider to bear against the shaft 132.

The use and operation of this embodiment are as follows:

The fitting 126 is connected to the intake manifold so that the area approximately below the valve plate 148 is subjected to the pressure that exists in the manifold. When that pressure becomes suiiiciently low, the atmospheric pressure in the upper chamber above the valve and the plate 143 will force the shaft downward to open the valve and allow a passage of air through the valve structure into the manifold. Due to the passage of air therethrough into the manifold, the pressure above the valve structure will be reduced, this reduction being communicated to the diaphragm chamber structure in the same manner as explained with reference to the embodiment of Figures 1 through 5, thus opening the aperture $4 and admitting air through the opening 106 to the idle well fuel jet.

In the embodiment of Figures 1 through 5, the valve plate 62 performs only the function of closing and opening the orifice defined by the valve seat 58, and the plate 72 in connection with the upper housing constitutes a restricting means to the flow of the air passing downwardly from the upper chamber through the valve structure into the intake manifold. However, in the embodiment of Figures 6 and 7, the valve plate has been extended so as to closely approach the inside diameter of the housing, and this plate in addition to performing the function of opening and closing the orifice defined by the valve seat also performs the function of restricting the flow of air to the intake manifold once the valve has been opened. Consequently, the circular plate 72 and the upper end of the shaft 42 have been eliminated from the embodiment of Figures 1 through 5. Both the circular plate 72 in Figures 15, inclusive, and the valve plate 148 in Figures 6 and 7 serve to retain the spring compressed and the valve open until the vacuum in the manifold reaches a predetermined amount which is a great deal less than that required to open the valve.

The lowermost position of the shaft 132 in its movements of opening and closing the valve is defined by the lower end of the retainer 152 which will abut against the lower spider 137. The upper position of the shaft 132 is reached when the valve plate 148 contacts the Valve surface 146.

The upper housing 120 in this embodiment may also be removed in a manner similar to that of the structure of Figures 1 through 5. Once the circular bracket 124 has been removed, the upper housing can be lifted vertically so as to expose the valve mechanism. As the valve seat 144 and the upper spider 139 are firmly attached to the upper housing at 142, when the upper housing is lifted, these parts will also be removed and the shaft 132 with the valve plate 148 will remain exposed and be easily accessible for maintenance, repair, and cleaning.

While I have shown and described a preferred form and one modification of my invention, it should be understood that these are only illustrative and should not be interpreted to restrict or confine my invention except as by the appended claims.

I claim:

1. A vacuum breaker for use with an internal combustion engine comprising a low pressure chamber, a normal pressure chamber, and a valve structure between the chambers adapted to open and close so as to establish and extinguish communication between the chambers at predetermined pressures in the low pressure chamber including a valve seat, a valve plate mechanism adapted to engage the seat, yielding means biasing the plate toward the seat, restricting means adapted to restrict the flow of the air through the valve structure during its open periods, and damping means in engagement with the valve plate mechanism to regulate the movements of the same.

2. A vacuum breaker for use with an internal combustion engine comprising a low pressure chamber, a normal pressure chamber, and a valve structure between the chambers adapted to open and close so as to establish and extinguish communication between the chambers at predetermined pressures in the low pressure chamber including a valve seat, a valve plate mechanism adapted to engage the seat, yielding means biasing the plate toward the seat, restricting means adapted to restrict the flow of the air through the valve structure during its open periods, and damping means in engagement with the valve plate mechanism to regulate the movements of the same, said valve plate mechanism including a shaft movable longitudinally within said chamber, and at least one bearing in the chamber adapted to permit longitudinal movement of the same.

3. For use with an internal combustion engine having an intake manifold, a vacuum controlled device which includes a low pressure chamber adapted to be connected to the intake manifold of the engine, a normal pressure chamber open to the atmosphere, and a valve mechanism between the low pressure chamber and the normal pressure chamber adapted to open and establish communication between the two chambers at a predetermined pressure in the manifold, said valve structure including a valve seat, a valve plate mechanism adapted to engage the seat, yielding means biasing the plate toward the seat, restricting means adapted to restrict the flow of the air through the valve structure during its open periods, said valve plate mechanism including a shaft movable longitudinally within said chambers, and bearing means in the chambers adapted to permit longitudinal movement of the shaft.

References Cited in the file of this patent UNITED STATES PATENTS 2,036,205 Ericson Apr. 7, 1936 2,443,562 Hieger et al June 15, 1948 2,453,125 Flint Nov. 9, 1948 2,496,679 Saurer Feb. 7, 1950 2,573,623 St0ver Oct. 30, 1951 2,598,224 Clonts May 27, 1952

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