US3210004A

US3210004A - Thermostatic choke valve

Info

Publication number: US3210004A
Application number: US247253A
Authority: US
Inventors: Paul R Hunt; Bois Chester Du
Original assignee: Outboard Marine Corp
Current assignee: Outboard Marine Corp
Priority date: 1962-12-26
Filing date: 1962-12-26
Publication date: 1965-10-05
Anticipated expiration: 1982-10-05

Description

Oct. 5, 1965 P. R. HUNTETAL 3,210,004

THERMOSTA'I'IC CHOKE VALVE Filed Dec. 26, 1962 INVENTORS. 401. 16 4 0? gx/wrze 0 5 /5 W,mym

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United States Patent 3,210,094 THERMOSTA'IIC CHOKE VALVE Paul 1%. Hunt, Lindenhurst, and Chester Du Rois, Zion,

Ill., assignors to Qutboard Marine Corporation, Waukegan, Ill., a corporation of Delaware Filed Doc. 26, 1962, Ser. No. 247,253 14 Claims. (Cl. 236101) The invention relates generally to chokes such as are associated with carburetors or other combustion air-intake arrangements for internal combustion engines. More specifically, the invention relates to automatic chokes including temperature responsive means for providing a variably controlled air flow so as to obtain a variably enriched fuel-air mixture for engine starting and operating.

For various reasons including, for instance, a sticky choke shaft, damage to the temperature responsive automatic operating means, or faulty delivery of heat to the temperature responsive means, the operation of an automatic choke may become either partially or wholly unreliable or ineffective.

The invention provides means for manually overriding the automatic operation of the choke, preferably by means for impositively or resiliently closing the choke and for positively opening the choke. More particularly, in one embodiment of the invention, the overriding positive and impositive means are both mounted on a single member which is shiftable from an automatic setting to a first or closed position removed from said automatic setting and to a second or open position remote from the automatic setting. In said one embodiment, the automatic temperature responsive means also is mounted on the shiftable member.

Other objects and advantages of the invention will become known by reference to the following description and the accompanying drawings of one embodiment of the invention.

In the drawings:

FIGURE 1 is an elevational view partially in section of a choke 11 in accordance with the invention;

FIGURE 2 is a plan view taken generally along line 2-2 of FIGURE 1;

FIGURE 3 is a view taken generally along line 3-3 of FIGURE 1, showing the choke in its automatic control setting and with the choke valve member closed;

FIGURE 4 is a view similar to FIGURES 2 and 3, showing the choke in its manually closed settitng;

FIGURE 5 is a view similar to FIGURES 2, 3, and 4, showing the choke in its manually open setting; and

FIGURE 6 is a perspective view showing the mounting of an automatic choke, such as disclosed herein, on an internal combustion engine.

As shown in the drawings, the choke 11 comprises, in part, a frame or element 13 including an air or gas passage 14, and a shaft 15 extending across the passage 14 and carrying a valve member or plate 17. The shaft 15 is rotatably journaled by the frame 13 for variably locating the valve member 17 between a substantially open position, shown in outline in FIGURE 5, wherein the valve member 17 lies substantially in a plane extending axially of the air passage 14 and a closed position, shown in outline in FIGURE 4, wherein the valve member 17 extends across the air passage 14 in generally blocking relation thereto at an angle of about 75 degrees relative to its open position. v

The frame 13 also includes or has mounted thereon a housing or chamber 19 which contains an operating mechanism 21 connected to the shaft 15. Although various configurations can be employed, the housing 19 is generally cup shaped and is closed by a cap or cover 23 which is angularly shiftable around the mouth of the "ice housing 19 and is connected to a handle 25 to facilitate such angular shifting.

More specifically, the cap 23 is retained on the housing 19 by a retainer ring 27 which can be secured to the housing 19 by suitable means, as for example, a plurality of screws 29. Notwithstanding the angular shiftability of the cap 23 to the housing 19, the cap 23 is sealed to the housing 19 and friction is reduced by means of a pair of gaskets 31 and 33 respectively interposed between the retaining ring 27 and the cap 23 and between the cap 23 and the housing 19. The cap 23 and its attached handle 25 are shiftable relative to, and between, manually closed and manually open positions located approximately 180 degrees apart and shown respectively in FIGURES 4 and 5, and relative to an intermediate automatic position located midway between the open and closed positions, as shown in FIGURES 2 and 3.

Passing through the cap 23 and through a hub 35 projecting from the undersurface of the cap 23 is a stud 37 which is angularly shiftable about its own axis relative to the cap 23 and which extends into the housing 19 in generally axial alignment with the shaft 15. Carried by the stud 37 is a temperature sensitive or responsive means in the form of a bimetallic element or coil 39 having an outer free end which is indicated at 41 and which is reversely curved or hooked. The outer hooked end 41 of the bimetallic coil 39 is located for engagement with an arm 43 which extends in parallel relation to the axes of the stud 37 and shaft 15 and which constitutes one part of a right angle leg or bracket 45 fixed to the end of the shaft 15 extending in the housing 19.

In order to adjust the choke, means are provided for varying the relation of the bimetallic coil 39 to the cap 23. In the specifically disclosed construction, such means take the form of an arrangement including a plate 47 which is fixed to the outer end of the stud 37 and which is angularly positionable on the top surface of the cap 23. The plate 47 can be fixed in any desired position of angular relation to the cap 23 by means including an arcuate cut out 48 in the plate 47 and a screw 49 which connects the handle 25 to the cap 23 and which passes through the cut out 48. By loosening the screw 49, the plate 47 and the connected stud 37, together with the bimetallic coil 39, can be angularly shifted relative to the cap 23. When a desired adjustment is obtained, the screw 49 is then tightened to prevent further relative angular movement between the plate 47 and the cap 23.

When the bimetallic coil 39 is cold, and when the cap 23 is in automatic position, as shown in FIGURES 2 and 3, the hooked outer end 41 of the bimetallic coil 39 is positioned to engage the arm 43 to locate the valve member 17 in its closed position. Heating of the bimetallic coil 39 causes its hooked outer end 41 to rotate in a counterclockwise direction, as shown in FIGURE 3, permitting the arm 43 to move, under the influence of gas flow within the air passage 13 from the closed position, shown in full lines in FIGURE 3, to the open position shown in dotted outline in FIGURE 3. Should the bimetallic coil 39 again cool, the hooked end 41 will rotate in a clockwise direction toward the closed, full line position shown in FIGURE 3, thereby proportionately restricting the amount of gas flow permitted by the valve member 17 as the hooked end of the bimetallic coil travels from its open position to its closed position.

The air passageway 14 can be manually closed, when the bimetallic coil is heated, by rotating the cap 23 in a clockwise direction as seen in FIGURES 2 through 5, through an angle of about degrees from the automatic setting to the position shown in FIGURE 4. Counter-clockwise movement of the cap 23 can be limited to about 90 degrees by suitable means, such as by en- 3 gagement of a stop 51 on the top surface of the cap 23 with a radially inwardly extending detent or lug 53 projecting from the retainer ring 27.

Such movement of the cap to its manually closed position rotates the stud 37 and the connected bimetallic coil 39 through a corresponding angle. In the event the bimetallic coil 39 is cooled with its hooked end located as shown in full lines in FIGURE 3, such movement will effect resilient displacement of the bimetallic coil 39 from its normal relation to the stud 37. In the event the bimetallic coil 39 is heated and the valve member 17 is at least partially open, the hooked end 41 will be rotated so as to engage and at least partially advance the arm 43 toward its closed position.

However, in the event that the linkage between the cap 23 and the shaft is interrupted, as by breaking of the bimetallic coil 39 or by loosening of the screw 49, thereby permitting shifting of the plate 4-7 relative to the cap 23, movement of the arm 43 to its valve member closing position is assured by biasing means which, in the specifically disclosed construction, takes the form of a spring 55 carried by the cap 23.

More specifically, the spring 55 is formed with at least one coil encircling the hub and is fixedly connected, by suitable means indicated at 56 in FIGURE 3, at the end of one leg 57 to the cap 23. The other leg 59 projects into a position for engagement with the arm 43 to displace the arm to its valve member closing position in response to rotation of the cap 23 to its manually closed position. As the full range of movement of the arm 43 between its open and its closed positions is through an arc of about 75 degrees, movement of the spring through an angle of 90 degrees, by reason of like angular shifting of the cap 23 to its manually closed position, serves both to engage the arm 43 by the spring in response to initial shifting of the cap 23 and to locate the end or leg 59 of the spring 55 in a tensioned condition after displacement of the arm 43 to its valve member closing position. Consequently, maintenance of the valve member 17 in closing relation to the air passage 14 is assured when the cap 23 is in its manually closed position.

Notwithstanding the above, when the cap 23 is in its manually closed position with the valve member 17 retained in closing relation to the air passage 14 by the spring 55 and by the bimetallic coil 39, the arrangement permits breathin through the air passage 14 by reason of valve member action against the torque loading of the bimetallic coil 39 and spring 55 in response to a sufiicient draft or vacuum in the air passage 14. Such breathing provides the operator with time to reset the cap to its automatic position before the engine dies because of an excessiveiy rich mixture.

When a lean mixture is required for starting, the cap 23 can be rotated to the manually open position shown in FIGURE 5. Such action can occur when the bimetallic coil 39 is cold and in the position shown in FIGURE 3. Because of the absence of fixed engagement between the bimetallic coil 39 and the arm 43, mere rotation of the bimetallic coil 39 in a counterclockwise direction as seen in FIGURE 5, accompanying like rotative movement of the cap 23, will not effect positive movement of the valve member 17 from its closed position in the absence of a sufficient pressure differential or draft across the opposite faces of the valve member. Accordingly, means in the form of a lug 61 is provided on the undersurface of the cap 23, which lug projects for engagement with the arm 43 in response to movement of the cap through an arc of about 90 degrees from the automatic position. As only about 75 degrees of rotation is required to displace the arm 43 from its valve member closing position to its valve member opening position, the initial 15 degrees of movement of the cap 23 permits disengagement of the hooked end 41 of the bimetallic coil 39 from the arm 43 prior to engagement of the lug 61 with the arm. Thus, movement of the arm 43 from its valve member closing position to its valve member opening position occurs entirely without any load on the bimetallic element.

Upon return of the cap 23 to its automatic position, the hooked end 41 of the bimetallic coil 39 will engage the arm d3 for movement of the arm between its valve member opening position and its valve member closing position in accordance With the extent to which the bi metallic coil 39 is heated. Movement of the cap 23 through the automatic position to the manually closed position will effect displacement of the arm 43 to its valve member closing position, notwithstanding any heated condition of the bimetallic coil 39 by action of the spring 55.

Various arrangements can be used to effect heating of the bimetallic coil 3% in response to heating of the engine. For instance, the housing 19 could be arranged so that it is mounted on an engine block or otherwise conveniently located so as to be heated by conduction. In FIGURE 6, a choke 111 embodying various of the features of the invention is shown mounted on the exhaust manifold of an engine 105 so as to receive heat from the engine incident to operation thereof. In addition, or alternatively, the heat source for the bimetallic coil 33 can take the form of an air flow which has been previously heated by the exhaust of the engine and which is drawn into the housing by intake manifold vacuum pressure, as for instance, through a conduit 65 such as shown in FIGURE 5.

While the discussed arrangement has included a handle 25 attached to the cap 23 for angularly shifting the cap, various arrangements such as cable or other means can be employed for angularly shifting the cap from a remote point.

Various of the features of the invention are set forth in the following claims.

What is claimed is:

1. A choke for controlling gas fiow comprising means defining a gas passage, a valve member, means mounting said valve member in said gas passage for rotative movement about an axis transverse to said gas passage between a first position closing said passage and a second position permitting relatively free flow through said passage, temperature responsive means free of fixed connection with said valve member and operative to connect with said valve member for controlling the movement of said valve member between said first position and said second position, and manually operative means for locating said valve member relative to said first and second positions notwithstanding the action of said temperature responsive means.

2. A choke for controlling gas flow comprising means defining a gas passage, a valve member, means mounting said valve member in said gas passage for rotative movement abount an axis transverse to said gas passage between a first position closing said passage and a second position permitting relatively unobstructed flow through said passage, temperature responsive means free of fixed connection with said valve member and operative to connect with said valve member for displacing said valve member from said second position to said first position in response to a change in one direction of the temperature of said temperature responsive means and for permitting movement of said valve member from said second position to said first position in response to a change in the other direction of the temperature of said temperature responsive means, and manually operative means for locating said valve member relative to said first and second positions notwithstanding the ac tion of said temperature responsive means.

3. A choke for controlling gas flow comprising means defining a gas passage, a valve member, means mounting said valve member in said gas passage for displacement between a first position closing said passage and a second position permitting relatively unobstructed fiow through said passage, means connected to said valve member for displacing said valve member between said first and second positions, temperature responsive means having a portion disposed for engagement with said valve member displacing means to displace said valve member to its first position in response to cooling of said temperature responsive means from a relatively heated condition and for permitting movement of said valve member from its first position toward its second position in response to heating of said temperature responsive means from a relatively cool condition, manually shiftabtle resilient means connected to said gas passage defining means for engaging said valve member displacing means to locate said valve member in said first position notwithstanding the action of said temperature responsive means, and manually shiftable rigid means connected to said gas passage defining means for engagement with said valve member displacing means to locate said valve member in its second position notwithstanding the action of said temperature responsive means.

4. A choke for controlling gas flow comprising means defining a gas passage, a valve member, means mounting said valve member in said gas passage for displacement between a first position closing said passage and a second position permitting relatively unobstructed flow through said passage, means for displacing said valve member between said first and second positions including a crank arm connected to said valve member and movable between a first position locating said valve member in its first position and a second position locating said valve member in its second position, means manually shiftable for movement in opposite directions from a predetermined position, resilient means carried by said shiftable means for engaging said crank arm to locate said crank arm in its first position in response to movement of said shiftable means in one direction from said predetermined position, fixed means on said shiftable means in position for engagement with said crank arm to locate said crank arm in its second position in response to movement of said shiftable means from said predetermined position in a direction opposite from said one direction, and temperature responsive means carried by said shiftable means and having a portion disposed, when said shiftable means is in said predetermined position, for movement in the path of movement of said crank arm for engagement with said crank arm to displace said crank arm to its first position in response to cooling of said temperature responsive means from a relatively heated condition and for permitting movement of said crank arm from its first position toward its second position in response to heating of said temperature responsive means from a relatively cool condition.

5. A choke in accordance with claim 4 including means for limiting movement of said manually shiftable means in said one direction to control the stress in said resilient means.

6. A choke in accordance with claim 4 wherein said temperature responsive means is carried on said manually shiftable means by means for selectively shifting the disposition of said temperature responsive means relative to said manually shiftable means.

7. A choke for controlling gas flow comprising means defining a gas passage, a valve member, means mounting said valve member in said gas passage for angular displacement between a first position closing said passage and a second position permitting relatively unobstructed flow through said passage, means for displacing said valve member between said first and second positions including a crank arm connected to said valve member and movable between a first position locating said valve member in its first position and a second position locating said valve member in its second position, means manually shiftable for movement through a first angular distance greater than the angular distance between said first and second positions of said valve member between a first closed position and a second automatic position and for movement through a second angular distance greater than the angular distance between said first and second positions of said valve member between said automatic position and a third open position, resilient means carried by said shiftable means for engaging said crank arm to locate said crank arm in its first position in response to movement of said shiftable means from its automatic position to its closed position only after an initial range of movement from said automatic position less than the difference between the range of angular movement of said valve member and the range of angular movement of said shiftable means between its automatic and its closed positions, fixed means on said shiftable means in position for engagement with said cank arm to locate said crank arm in its second position in response to movement of said shiftable means from its automatic position to its open position only after an initial range of limited movement from said automatic position, temperature responsive means carried by said shiftable means and having a portion disposed, when said shiftable member is in its automatic position, for movement in the path of movement of said crank arm for engagement with said crank arm to displace said crank arm to its first position in response to cooling of said temperature re- ,sponsive means from a relatively heated condition and so as to permit movement of said crank arm from its first position toward its second position in response to heating of said temperature responsive means from a relatively cool condition.

8. A choke for controlling gas flow comprising a frame including means defining a gas passage, a cup-shaped housing on said frame, a shaft extending across said gas passage and into said housing, a valve member on said shaft in said gas passage, means mounting said shaft for angular displacement of said valve member between a first position closing said passage and a second position permitting relatively free flow through said passage, a crank arm in said housing connected to said shaft and movable between a first position locating said valve member in its first position and a second position locating said valve member in its second position, a cover, means mounting said cover on said housing for manual angular shifting relative to said housing in opposite directions from a predetermined position, a spring carried by said cover in said housing and including an end displaceable in the path of movement of said crank arm for engaging said crank arm to locate said crank arm in its first position in response to movement of said cover in one direction from said predetermined position, a lug on said cover within said housing in position for engagement with said crank arm to locate said crank arm in its second position in response to movement of said cover from said predetermined position in a direction opposite from said one direction, and a bimetallic coil carried by said cover within said housing and having a hooked end portion disposed, when said cover is in said predetermined position, for movement in the path of movement of said crank arm so as to engage said crank arm to displace said crank arm to its first position in response to cooling of said temperature responsive means from a relatively heated condition and so as to permit movement of said crank arm from its first position toward its second position in response to heating of said temperature responsive means from a relatively cool condition.

9. A choke in accordance with claim 8 wherein said cover is angularly shiftable about an axis in alignment with the rotational axis of said shaft.

10. A choke in accordance with claim 8 including means for limiting movement of said cover in said one direction to control the stress in said spring.

11. A choke in accordance with claim 8 wherein said bimetallic coil is carried on said cover by means for selectively shifting the disposition of said bimetallic coil relative to said cover.

12. A choke in accordance with claim 8 in combination with an internal combustion engine and means munting said choke on said engine in position for heating said housing in response to operation of said engine.

13. A choke for controlling gas flow comprising means defining a gas passage, a valve member, means mounting said valve member in said gas passage for rotative movement about an axis transverse to said passage between a first position closing said passage and a second position permitting relatively free flow through said passage, temperature responsive means for controlling the movement of said valve member between said first position and said second position, and manually operative means free of fixed connection with said valve member and operative to connect with said valve member for locating said valve member relative to said first and second positions notwithstanding the action of said temperature responsive means.

14. A choke for controlling gas flow comprising means defining a gas passage, a valve member, means mounting said valve member in said gas passage for rotative movement about an axis transverse to said passage between a first position closing said passage and a second position permitting relatively unobstructed flow through said pas sage, temperature responsive means engageable with said valve member for displacing said valve member from said second position to said first position in response to a change in one direction of the temperature of said temperature responsive means and for permitting movement of said valve member from said second position to said first position. in response to a change in the other direction of the temperature of said temperature responsive means, and manually operative means free of fixed connection with said valve member and operative to connect with said valve member for locating said valve member relative to said first and second positions notwithstanding the action of said temperature responsive means.

References Cited by the Examiner UNITED STATES PATENTS 1,530,850 3/25 Partlow 236-102 1,849,906 3/32 Carson 23642 2,019,589 11/35 Weber 23610l 2,180,800 11/39 Cyr 236-101 X 2,351,190 6/44 Carlson 236-92 2,571,602 10/51 Neuser 236101 2,646,933 7/55 Boyce 236-101 EDWARD J. MICHAEL, Primary Examiner.

ALDEN D. STEWART, Examiner.

Claims

1. A CHOKE FOR CONTROLLING GAS FLOW COMPRISING MEANS DEFINING A GAS PASSAGE, A VALVE MEMBER, MEANS MOUNTING SAID VALVE MEMBER IN SAID GAS PASSAGE FOR ROTATIVE MOVEMENT ABOUT AN AXIS TRANSVERSE TO SAID GAS PASSAGE BETWEEN A FIRST POSITION CLOSING SAID PASSAGE AND A SECOND POSITION PERMITTING RELATIVELY FREE FLOW THROUGH SAID PASSAGE, TEMPERATURE RESPONSIVE MEANS FREE OF FIXED CONNECTION WITH SAID VALVE MEMBER AND OPERATIVE TO CONNECT WITH SAID VALVE MEMBER FOR CONTROLLING THE MOVEMENT OF SAID VALVE MEMBER BETWEEN SAID FIRST POSITION AND SAID SECOND POSITION, AND MANUALLY OPERATIVE MEANS FOR LOCATING SAID VALVE MEMBER RELATIVE TO SAID FIRST AND SECOND POSITIONS NOTWITHSTANDING THE ACTION OF SAID TEMPERATURE RESPONSIVE MEANS.