US 3081793 A
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March 19, 1963 J. H. FLAT-r ETAL 3,081,793
VALVE MECHANISM Filed Feb. 1s, 1961 INV EN TORS A FTORNEV Patented Mar. 19, 1953 mee 3,081,793 VALVE MECHANISM James H. Flatt and Donald G. Guetersloh, Anderson, Ind., assignors to General Motors Corporation, Detroit, Mich., a corporation of Delaware Filed Feb. 13, 1961, Ser. No. 88,815 3 Claims. (Cl. 137-620) The present invention relates to a valve mechanism particularly adapted for use with an anti-smog controlling device generally of the type shown in copending application A-436 Bale et al.
As some engines are throttled down there is an unaccounted for sound created which has been characterized as a blooping noise or a chuckle The cause of this noise is not known, however, the subject valve mechanism has been developed which obviates such noise. While the subject Valve mechanism has been developed in conjunction with an anti-smog program, it is assumed that it would be effective to eliminate such noise from a carburetion system whether or not an anti-smog device was involved.
In general, the present valve mechanism includes a pair of loosely mounted valve members which alternatively communicate manifold vacuum to the distributor servo device, to advance the spark, or block manifold vacuum from such device while at the same time communicating the latter with atmospheric pressure to retard the spark.
The details as well as other objects and advantages of the present invention will be apparent from a perusal of the detailed description which follows.
The drawing is a diagrammatic representation of a portion of an engine controlling system embodying the subject valve mechanism.
An intake manifold is indicated generally at and has a carburetor 12 mounted thereon. Carburetor 12 includes a throttle valve 14 for controlling the quantity of combustible mixture admitted to the manifold. A conventional spark distributor mechanism is shown generally at 16 and includes a diaphragm servo device 18 adapted to advance or retard the engine spark in accordance with variations in manifold depression. Distributor servo device f8 is connected to manifold d0 through conduits 20 and 22 and valve mechanism 24 disposed therebetween.
Valve mechanism 24 includes a casing 26 having counterbored portions 2S and 30 communicated through a reduced diameter longitudinal opening 32 formed through wall 34. A passage 36 is formed in casing wall 34 transvensely of and communicating with longitudinal opening or passage 32. Conduit 2t) communicates with transverse passage 36. A port 38 is formed in casing 26 and through conduit 22 communicates counterbore 2S with intake manifold 10.
A pin k40 is loosely disposed within longitudinal opening 32 and is respectively engaged at its ends by valve discs 42 and 44 loosely disposed within counterbores 28 and 30. A plug member 46 encloses one end of valve casing 26 and provides a seat for a spring 48 the other end of which biases valve disc 42 in engagement with pin 40. Valve disc 44 is similarly biased against pin 4i) by a suitable spring member to be subsequently described.
A second plug 5l) is `disposed in the other end of casing 26 and includes a central opening 52 therethrough. A diaphragm assembly is mounted on plug 50 and includes a pair of casing members 54- and 56 peripherally clamping a liexible diaphragm 58 therebetween. Casing 54 includes a central opening aligned with plug opening 52 and through which a rod 6() centrally fixed to diaphragm S8 extends to engage valve disc 44. A spring member 62 seats against casing 56 and engages a reinforcing ring 64 centrally secured to diaphragm y58 to urge the diaphragm and rod 60 to the left as shown.
Chamber 66 defined by diaphragm 5S and casing 56 is communicated with intake manifold 10 through a conduit 68. Chamber 70 defined by diaphragm 58 and casing 54 is open to the atmosphere through casing opening 72. Longitudinal opening 52 in end plug 5()` is sufficiently larger than rod 60 to admit atmospheric pressure to valve casing counterbore 30.
Under normal operating conditions, manifold vacuum in chamber 66 will be of insufficient force to overcome spring 62 whereby the valve parts will be in the position shown in the drawing. In this case, manifold vacuum will be admitted to distributor servo device 18 since valve disc 42 is moved ofi? or away from its seat 74 by diaphragm spring `62. At the same time valve disc 44 is maintained against its seat 76 blocking the admission of atmospheric pressure to conduit 20. On the other hand, when manifold vacuum exceeds a predetermined value, e.g., as will occur when the vehicle is coasting, the force of such vacuum in chamber 66 will overcome spring 62 moving diaphragm 58 to the right and thereby permitting spring `48 to seat valve disc 42 and at the same time moving pin 40 to unseat valve disc 44. In this manner manifold vacuum is cut off from distributor servo device 18 while the unseating of valve disc 44 opens the servo device to atmospheric pressure insuring that the distributor spark advance will be fully retarded.
As engine speed decreases the manifold vacuum acting on diaphragm 58 also decreases. When this vacuum force decreases sufficiently spring 62 will cause valve 44 to be closed and valve 42 to be opened restoring the system to its normal condition.
Whatever the reason for the aforenoted objectionable noise which has previously occurred during engine coasting operation, the present valve device in permitting the rapid cutting off of manifold vacuum and the admission of atmospheric pressure to the distributor servo device has eliminated such noise.
l. A valve mechanism of the type adapted to control the admission of manifold vacuum to an engine spark distributor servo device in which said mechanism includes a valve casing having longitudinally aligned first and second counterbored portions separated by a wall, a longitudinal opening formed in the casing wall and interconnecting said portions, seats formed on said casing wall at each end of said longitudinal opening, a pin member' loosely disposed in said opening and adapted to extend longitudinally therebeyond, first and second disc valve members respectively disposed in said first and second counterbored portions, first and second spring members respectively urging each of said valve disc members axially into engagement with the ends of said pin, a vacuum inlet port formed in said casing means and communicating with said first counterbored portion, a vacuum outlet port formed in said casing wall and communicating with said longitudinal opening, the second counterbored casing portion being open to the atmosphere, said :second spring member being adapted to seat the second and unseat the first valve disc members and thereby communicate the inlet and outlet ports, and a vacuum responsive diaphragm device adapted to overcome the second spring member permitting the first spring member to seat the first and unseat the second disc valve members whereby the cornmunication between the inlet and outlet ports is blocked and the latter opened to the atmosphere.
2. A valve mechanism as set forth in claim 1 in which the vacuum responsive diaphragm device comprises a pair of casing members, a diaphragm peripherally clamped between said casing members, a rod centrally secured to the diaphragm and extending within the second. counterbored 3 il portion of said casing to engage the second `disc valve References Cited in the e of this patent member.
3. A Valve mechanism as set forth in claim 2 in which UNITED STATES PATENTS the second springlmember is disposed between One 0f 2,229,821 Seymour jan 2g, 1941 the draphragm dev1ce casrng members and the draphragm 5 2,925,066 Thomer Feb 15l 1960 toseat the second and unseat the first disc valve members.
UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,081 ,793 March 19 1963 .Iames H. Flatt et al.
It is hereby certified that error appears in the above numbered patd that the said Letters Patent should read as ent requiring correction an corrected below.
Column 1, lines lO and 1l, for "copending application A-l Bale et al." read Unite Signed and sealed this '7th day of January 1964.
(SEAL) Attest: EDWIN L. REYNOLDS ERNEST w. swIDEE Attesting Officer Ac t i ng Commissioner of Patents d States Patent 8,027 ,884.