US2991053A

US2991053A - Vacuum controlled dampening device for secondary throttles

Info

Publication number: US2991053A
Application number: US758207A
Authority: US
Inventors: Thomas F Cramer
Original assignee: Holley Carburetor Co
Current assignee: Holley Performance Products Inc
Priority date: 1958-09-02
Filing date: 1958-09-02
Publication date: 1961-07-04
Anticipated expiration: 1978-07-04

Description

y 4, 1961 T. F. CRAMER 2,991,053

VACUUM CONTROLLED DAMPENING DEVICE FOR SECONDARY THROTTLES Filed Sept. 2, 1958 2. Sheets-Sheet 1 m o a} o N 0 Q- 9\ o m O O (I) (O Y q- LO 3 m u u INVENTOR.

THOMAS F. GRAMER ATTORNEYS July 4, 1961 -r. F. CRAMER 2,991,053

VACUUM CONTROLLED DAMPENING DEVICE FOR SECONDARY THROTTLES Filed Sept. 2, 1958 2 Sheets-Sheet 2 4 62 6o 58 FIG.2. I72

7: 9 o 54 070 Q o 30 v 64 I64 56 o o 52 I68 38 o 7 I24 5 (6;

I J FIG.5.

j INVENTOR.

THOMAS F.CRAMER BY w m 441/ ATTORNEYS United States Patent() 2 991 053 VACUUM CONTROLLED DAMPENING DEVICE FOR SECONDARY TI-IRO'ITLES Thomas F. Cramer, Warren, Mich., assignor to Holley Carburetor Company, Van Dyke, Mich., a corporation of Michigan Filed Sept. 2, '1958, Ser. No. 758,207

Claims. (Cl. 261-23) This invention pertains to a selective dampening device and more particularly to a dampening device for use with a secondary throttle plate in an internal combustion engine multiple stage carburetion system.

A multiple stage carburetion system comprises an operator-controlled primary throttle plate assembly and a venturi vacuum controlled secondary throttle plate assembly which is operable to supply additional air flow to the combustion chambers at high speeds.

a In engines having governing systems wherein at govapplying a dampening or resisting movement to the secondary plate so that its initial closing after governing is modified and subsequent changing of the primary throttle plate is substantially eliminated.

The dampening action is provided by a piston which is operated in a closed cylinder with restrictions formed in the piston walls to provide limited fluid movement therethrough resulting in a controlled piston movement. The piston is connected to the secondary throttle plate and the cylinder has a lost motion connection to an en- .gine-vacuum-responsive rod. Placed intermediately of the cylinder and the lost motion connection is a fork which is registrable with a lock attached to the carburetor body and under the proper vacuum conditions, the vacuum-responsive rod is moved against spring pressureto engage the fork with the lock so that any subsequent movement of the secondary throttle will be subject to the controlled movement of the piston in the cylinder, thereby dampening the quick secondary plate movement and preventing hunting.

It is therefore an object of this invention to provide in a governed, multiple-stage carburetion system means for eliminating the hunting which occurs at governed speeds.

Another object is to provide the secondary throttle plate assembly in such a system with dampening means which is selectively applied to prevent exceptionally quick plate movement and subsequent hunting of the secondary throttle plate.

A further object is to provide in a governed multiplestage carburetion system dampening means for the secondary throttle plate in the form of a piston and cylinder combination with the piston being connected to the secondary throttle plate and with the cylinder having a lost motion connection to an engine vacuum responsive member so that due to the lost motion connection the secondary throttle movement is unmodified and with lockingmeans to lock the cylinder against the carburetor body to eifect-ively eliminate the lost motion connection so that the secondary throttle plate is subject to the controlled movement of the piston in the cylinder.

taken in conjunction with the accompanying drawings,

FIG. 1 is a side elevational view with portions thereof in cross section of a four-barrel carburetor provided with a governor embodying the invention;

FIG. 2 is a side elevational view, with portions thereof in cross section, taken on the plane of line 2-4v of FIG. 1 and looking in the direction of the arrows;

FIG. 3 is a bottom plan view taken on the plane of line 3-*3 of FIG. 1 and looking in the direction of the arrows;

FIG. 4 is a sectional view taken along the line 4-4 of FIG. 3;

FIG. 5 is a view taken from the direction of arrow 5 in FIG. 4 showing the carburetor body attached lock.

Referring now to FIG. 1, a four-barrel carburetor 10, of the type referred to above and having an air intake 12, is sectioned to expose one of the primary barrels 14 and one of the secondary barrels 16. The primary barrel 14 is provided with a restriction or venturi throat 18 and a conventionally operated throttle plate 20 mounted on the shaft 22 which extends through the other primary barrel in which is mounted a throttle plate identical to plate 20. The secondary barrel 16 is also provided with a venturi throat 24 and a throttle plate 26 mounted on the shaft 28 which extends through the other secondary barrel in which is mounted another secondary plate.

While a particular four-barrel carburetor is shown for purposes of illustration, it will be apparent that the invention is equally applicable to two-barrel or other multistage carburetors.

-A vacuum device 30, commonly referred to as a governor diaphragm assembly, is mounted on the boss 32 extending from the carburetor throttle body 34. The

.36 by means of a cover member 44 formed to provide an air tight chamber 46 of which the flexible diaphragm 42 forms a wall. The cover member may be secured by any suitable means such as screws 47.

-As shown by FIGS. 1 and 2, the diaphragm 42 has secured to the center thereof in the conventional manner a rod 48 passing through passage 50 in the body 36 and having a. laterally extending end 52 pivotally secured to the lever 54 which is rigidly secured to the end 56 of the primary throttle shaft 22 extending into the chamber 38. The shaft 22 is mounted in an anti-friction bearing 39, and a spring 41 is disposed between the bearing 39 and the steel and

leather washers

43 and 45 to provide a seal. A tension spring 58 attached between the adjustable pin 60, mounted in one of the holes 62 in the body 36, and

the fixed pin 64, secured to the lever 54, tends to hold the primary throttle plate 20 in the open position. An atmospherically vented cover plate 66 may be secured by screws 68 to housing 36, thereby protecting the mechanism within chamber 38.

The orifice 72 at the primary venturi throat 18 and the orifice 74 below the primary throttle plate 20 are connected by means of the passages 76 and 78 having :fixed restrictions 80 and 82 respectively with the passage 84 in the :body member 36 and the passage 86 in the cover member 44 which lead to the chamber 46. A passage 88 connecting with passage 84 terminates in an opening in 102 in the sleeve by attachment at one end to the internally threaded member 104, which is keyed in passage 102. Spring 100 is adjustable axially of sleeve 98 by turning the adjustment screw v106 which is reached by removing the access screw 108. The other end of the spring 100 is secured to the governor weight 110 movable axially within the chamber 112 against the spring 100 and having at the free end thereof a valve 114 adapted to close the orifice .116 when the weight 110 is forced outwardly due to the rotation of the shaft 96 and the sleeve 98 in accordance with engine speed. The engine or vehicle speed at which the orifice 116 will be closed is dependent, of course, upon the adjustment of the spring 100. It is apparent, also, that some other governor valve structure may be employed.

A vacuum balancing air bleed is provided through assembly 92 to chamber 46 when orifice 116 is uncovered. Conduit 118 between the air intake 12 of the carburetor and the housing 94 and conduit 122 between the housing 94 and the passage 88 in the body 36 are provided so that when the engine or vehicle is operating at a speed insufiicient to close the orifice 116, engine vacuum will draw clean air through the conduit 118, into the housing 94, through the orifice 116 and into the chamber 112, through the passage 102 and the axial passage 120 in the shaft 96 and thence through the condui-t 122 to the governor diaphragm assembly 30. When the engine reaches governed speed, the orifice 116 is closed and the air bleed through conduit 122 is cut off. When this occurs, vacuum in the chamber 46 urges the diaphragm 42 downwardly, as in FIG. 2, against the spring 58 to close the primary throttle plates 20.

A secondary throttle diaphragm assembly 124 is mounted at the opposite side of the throttle body 34. This assembly comprises a body 126 having a recess 128 vented to the atmosphere through a plate 130 secured by screw 132 and a recess 134 closed by a flexible diaphragm 136 which is secured to the body 126 by means of a cover 138 formed to provide oppositely disposed

chambers

140 and 142 between which the flexible diaphragm 136 forms a movable wall. The chamber 142 contains a compression spring 144 positioned between the cover V138 and the rod 146, which is secured to the center of the diaphragm 136, so that the spring 144 urges the rod 146 upwardly to rotate the lever 148 secured rigidly to the secondary throttle shaft 28 counterclockwise, as in FIG. 3, and close the secondary throttle plates 26. A conduit 150 extending between the chamber 142 and the

vacuum passages

152 and 154 opening to the primary and

secondary venturi throats

18 and 24 enables primary and/or secondary venturi vacuum to evacuate the chamber 142 and displace the diaphragm 136 downwardly, as in FIG. 1, against the spring 144 to open the secondary throttle 26. The force of the spring 144 is selected so that the secondary throttle plate 26 will be open at any predetermined venturi vacuum.

The structure described above, or its equivalents, is well known in the art, and proper governing action depends upon the particular closing of the

throttle plates

20 and 26 when the engine or vehicle has reached a predetermined governing speed so as to diminish or cut ofl? the flow of motive fluid to the engine. However, in the case of dual carburetion as described above, the automatic closing of the secondary throttle plates 26 lags behind that of the primary throttle plates 20, particularly at governed engine speeds at which the second plates 26 are not fully open so that linkage (not shown) usually effective to positively close the secondary plates 26 with the primary plates 20 does not come into operation. While this is tolerable in the normal function of the dual carburetor, e.g., during acceleration, it is highly objectionable for the purposes of governing. This causes hunting, since the primary throttle plates have to first close farther than would otherwise be required to com- 4 pensate for the open secondary plates and then open when the secondary plates finally close.

In order to remedy this situation a dampening device is provided as shown in FIGS. 3-5. Diaphragm assembly 156 is welded or otherwise attached to diaphragm assembly 124 and has diaphragm 157 circumferentially secured therein and urged by spring 158 to an upward position. Tube 159 communicates with a vacuum source such as engine manifold vacuum or governor vacuum and lifts diaphragm 157 against spring 158. Attached to and movable with diaphragm 157 is rod 161 having a transversely extending pin 162 at the outer bifurcated end thereof which is engaged with slotted end 163 of threaded rod 164. Intermediate of the ends of rod 164 is fork 166 which is secured on either side by threaded nuts and is engageable with carburetor body attached lock 167. The other end of rod 164 is attached to closed, oil filled cylinder 168 having piston head 170 slidable therein. Formed along the walls of piston head 170 are longitudinal grooves 171 which permit limited flow of oil or other suitable fluid from one side of the piston head to the other opposing its movement and providing a dampening effect. Piston rod 172 is pivotally connected to arm 148 as indicated at 149.

In the operation of this device as governing speed is approached, an increase in the vacuum applied to the diaphragm 157 through tube 159 causes the diaphragm and rod 161 to move downwardly engaging fork 166 with lock 167. Any movement of secondary throttle lever 148 will now cause movement of piston head 170 in cylinder .168 and since this movement is restricted, movement of the secondary throttle will be dampened.

When the vacuum applied to diaphragm 157 is reduced, spring 158 will urge fork 166 to an unlocked position and movement of arm 148 will not be dampened. A lost motion connection between

rods

161 and 164 is provided so that in the unlocked position, rod 161 will not interfere with the movement of rod 164.

While control of the application of dampening elfect in accordance with manifold vacuum is satisfactory, it has been found that supplying governor pressure from line 122 results in a very desirable response movement of diaphragm 157 since this pressure is not as sensitive to slight changes in engine speed. Of course, other suitable actuating means for rod 161 may be used to properly and timely lock rod 164.

If desired, of course, all or any part of the structure shown herein may be incorporated into a single, compact carburetor unit adapted for placement in a vehicle engine compartment.

The drawings and the foregoing specification constitute a description of the improved vacuum controlled dampening device for secondary throttles in such full, clear, concise and exact terms as to enable any person skilled in the art to practice the invention, the scope of which is indicated by the appended claims.

What I claim as my invention is:

l. A dampening device for an internal combustion engine comprising a carburetor having a barrel in which a throttle plate is pivotally supported, actuating means for moving said throttle plate to various throttle plate positions in said barrel, dampening means engageable with said actuating means to dampen movement of said throttle plate, and selective means responsive to speed for operably connecting said dampening means with said actuating means at a selected engine condition which is also a function of speed to dampen throttle plate movement.

2. A dampening device for an internal combustion engine comprising a carburetor having a barrel in which a throttle plate is pivotally supported, actuating means for moving said throttle plate to various throttle plate positions in said barrel, a double acting piston movable in a closed, fluid filled cylinder, a restricted fluid passage between opposite piston ends to provide controlled piston movement in both directions, and means for selectively applying said controlled piston movement to the throttle plate under a selected engine condition which is a function of speed so that movement of the throttle plate is Subjected to a dampening action.

3. A dampening device for an internal combustion engine comprising a multiple stage carburetor having priand secondary barrels, a throttle plate pivotally mounted in. said secondary barrel, actuating means for 'moving said throttle plate to various throttle plate positions in said secondary barrel, a piston movable in a closed, fluid filled cylinder and arestricted fluid passage being between opposite piston ends to provide controlled piston movement, movable means responsive to a selected engine condition which is a function of speed, one of said piston and cylinder being connected to said actuating means and the other being connected through a lost motion connection to said movable means, and means for locking the other of said piston and cylinder when said movable means is actuated so that said actuating means is subject to the dampened movement of said piston in said cylinder.

4. A dampening device for an internal combustion engine comprising a multiple stage carburetor having primary'and secondary barrels, a throttle plate pivotally mounted in said secondary barrel, actuating means for moving said throttle plate to various throttle plate positions in said secondary barrel, a piston movable in a closed, fluid filled cylinder, a restricted fluid passage be tween opposite piston ends to provide controlled piston movement, engine governing means, movable means responsive to an engine governing condition which is a function of speed, one of said piston and cylinder being connected to said actuating means and the other being pivotally connected through a lost motion pivot connection to said movablemeans, fonked means connected to the other of said piston and cylinder, and lock means registrable with said forked means for relatively fixing the other of said piston and cylinder, said movable means being actuated upon the attainment of the engine governing condition which is a function of speed to urge said forked means into engagement with said lock means so that said actuating means is subject to the dampened movement of said piston in said cylinder.

5. A dampening device for an internal combustion engine comprising a carburetor having a barrel in which a throttle plate is pivotally supported, actuating means for moving said throttle plate to various throttle plate positions in said barrel, a piston movable in a closed, fluid filled cylinder, a restricted fluid passage between opposite piston ends to provide controlled piston movement, engine vacuum responsive means movable under a selected engine condition which is a function of speed, one of said piston and cylinder being connected to said actuating means and the other being connected through a lost motion connection to said engine vacuum responsive means, and means for locking the other of said piston and cylinder when said engine vacuum responsive means is moved so that said actuating means is subject to the dampened movement of said piston in said cylinder.

6. A dampening device for an internal combustion engine comprising a carburetor having a barrel in which a throttle plate is pivotally supported, actuating means for moving said throttle plate to various throttle plate positions in said barrel, a piston movable in a closed, fluid filled cylinder and a restricted fluid passage between opposite piston ends to provide controlled piston movement, locking means, one of said piston and cylinder connected to said throttle plate, the other connected to said locking means, and means responsive to an engine vacuum condition for holding said locking means in a relatively fixed position so that said throttle plate is subjected to the dampening action of said piston in said cylinder.

7. A multiple stage carburetor for an internal comnect and disconnect said dampening means to and from said secondary throttle.

8. Amultiple stage carburetor for an internal combustion engine comprising primary and secondary barrels,

primary and secondary throttles located respectively in said barrels, a speed governor for actuating said primary throttle, means responsive to an engine governing condition which is a function of engine load and speed, said means being connected to said secondary throttle for actuating the same, dampening means effective to oppose movement of said secondary throttle, and dampening control means responsive to an engine governing condition which is a function of speed to operatively connect and disconnect said dampening means to and from said secondary throttle, said dampening means comprising a piston member, a closed fluid filled cylinder member in which said piston member is movable, fluid flow remeans connecting one of said members to said secondary throttle.

9,. A multiple stage carburetor for an internal com- "bustion engine comprising primary and secondary barrels, primary and secondary throttles located respectively 'in said barrels, a speed governor for actuating said primary throttle, means responsive to an engine governing condition which is a function of engine load and speed, said means being connected to said secondary throttle for actuating the same, dampening means effective to oppose movement of said secondary throttle, and dampening control means to operatively connect and disconnect said dampening means to and from said secondary throttle, said dampening means comprising a piston member, a closed fluid filled cylinder member in which said piston member is movable, fluid flow restricting passage means connecting opposite end portions of said cylinder to restrict flow in both directions, and means connecting one of said members to said secondary throttle, said dampening control means being responsive to engine manifold vacuum.

10. A multiple stage carburetor for an internal combustion engine comprising primary and secondary barrels, primary and secondary throttles located respectively in said barrels, a speed governor for actuating said primary throttle, means responsive to an engine governing condition which is a function of engine load and speed, said means being connected to said secondary throttle for actuating the same, dampening means effective to oppose movement of said secondary throttle, and dampening control means to operatively connect and disconnect said dampening means to and from said secondary throttle, said dampening means comprising a piston member, a closed fluid filled cylinder member in which said piston member is movable, fluid flow restricting passage means connecting opposite end portions of said cylinder to restrict flow in both directions, and means connecting one of said members to said secondary throttle, said control means being responsive jointly to engine manifold vacuum and venturi vacuum.

11. A multiple stage carburetor for an internal combustion engine comprising primary and secondary barrels, primary and secondary throttles located respectively in said barrels, a speed governor for actuating said primary throttle, means responsive to an engine governing condition which is a function of engine load and speed, said means being connected to said secondary throttle for actuating the same, dampening means efiective to oppose movement of said secondary throttle dampening control means responsive to an engine governing condition which is a function of speed to operatively connect and disconnect said dampening means to and from said secondary throttle, said dampening means comprising a piston member, a closed fluid filled cylinder member in which said piston member is movable, fluid flow restricting passage means connecting opposite end portions of said cylinder to restrict flow in both directions, and means connecting one of said members to said secondary throttle, said dampening control means including means operably connected to the other of said members and means selectively effective upon the attainment of the engine governing condition to prevent movement of said other member and thereby oppose movement of said one member.

12. A multiple stage carburetor for an internal combustion engine comprising primary and secondary barrels, primary and secondary throttles located respectively in said barrels, a speed governor for actuating said primary throttle, means responsive to air flow to the engine, controlled in part by the positions of both of said throttles, said means connected to said secondary throttle for actuating the same, dampening means effective to oppose movement of said secondary throttle, and dampening control means responsive to engine manifold vacuum to operatively connect and disconnect said dampening means to and from said secondary throttle.

13. A multiple stage carburetor for an internal combustion engine comprising primary and secondary barrels, primary and secondary throttles located respectively in said barrels, a speed governor for actuating said primary throttle, means responsive to air flow to the engine, controlled in part by the positions of both of said throttles, said means connected to said secondary throttle for actuating the same, dampening means effective to oppose movement of said secondary throttle, and dampening control means responsive jointly to manifold and venturi vacuum to operatively connect and disconnect said dampening means to and from said secondary throttle.

14. A multiple stage oorburetor for an internal combustion engine comprising primary and secondary barrels, primary and secondary throttles located respectively in said barrels, a speed governor for actuating said primary throttle, means responsive to air flow to the engine, controlled in part by the positions of both of said throttles, said means connected to said secondary throttle for actuating the same, dampening means efiective to oppose movement of said secondary throttle, and dampening control means responsive to an engine governing condition which is a function of speed to operatively connect and disconnect said dampening means to and from said secondary throttle, said dampening control means including means operable only throughout a limited power range commencing at governor cut-oif.

15. A dampening device for an internal combustion engine comprising a carburetor having a throttle plate pivotally mounted therein, actuating means for moving said throttle plate to various throttle plate positions, and dampening means connected to said throttle plate, said dampening means being responsive to a selected engine condition which is a function of speed to selectively apply dampening action to the movement of the throttle plate.

References Cited in the file of this patent UNITED STATES PATENTS 2,315,912 Udale Apr. 6, 1943 2,609,187 Scott Sept. 2, 1952 2,703,705 Boller Mar. 8, 1955