US3793908A

US3793908A - Electric pneumatic shift control

Info

Publication number: US3793908A
Application number: US00243722A
Authority: US
Inventors: R Luft; Halvorson Leroy
Original assignee: International Harverster Corp
Current assignee: Ingersoll Rand Co; Navistar Inc
Priority date: 1972-04-13
Filing date: 1972-04-13
Publication date: 1974-02-26
Anticipated expiration: 1991-02-26
Also published as: CA1018269A

Abstract

A means for controlling a transmission from either one of a pair of operator stations. A multi-position cylinder conditions the transmission for a given direction of travel and speed range. Air pressure is directed to various chambers within the cylinder to achieve the desired position by a plurality of solenoid-operated valves. The valves are selectively energized by a circuit means, including a switch means located in each of the operator stations. A selector switch in one station selectively connects one of the switch means with a source of electrical energy.

Description

United States Patent Luft et al.

ELECTRIC PNEUMATIC SHIFT CONTROL 3,512,277 5/1970 Stuller 180/77 R X [75] Inventors: Robert G. Luft, Wildwood; LeRoy G. I-Ialvorson, lngleside, both of 111. Prlma'y McKem Attorney, Agent, or Firm-Ronald C. Kamp; Floyd B. [73] Assignee: International Harvester Company, Harman Chicago, Ill. [22] Filed: Apr. 13, 1972 [57] ABSTRACT [2l] Appl. No.: 243,722 A means for controlling a transmission from either one of a pair of operator stations. A multi-position cylinder conditions the transmission for a given direction Ill. of travel and Speed range. Air pressure is directed to [58] Fie'ld 180/77 S various chambers within the cylinder to achieve the desired position by a plurality of solenoid-operated 56] Reerences cued valves. The valves are selectively energized by a circuit means, including a switch means located in each UNHED STNI PATEN] 5 of the operator stations. A selector switch in one sta- 3,679.0l3 7/1972 u t v l 180/77 3 tion selectively connects one of the switch means with Bechman et Ell. a source of electrical energy 3,386,316 6/1968 Armantrout 74/870 3,487,725 1/1970 Brunot 74/870 X 7 Claims, 1 Drawing Figure 70 0 IV. ARM 68 F/w/vr M 5 $74710 1P 2 TRANSMISSION 64 1g 51 mks/firm? I F a- 22 3 1 5 0 54 X rM/vsH/ss/o/v XX gg lll o fill/F7071. 7-0 0:515 0 98 I 48 3 P 46 a 56 58 PEAPNSTATIOIV 14 A B D E F 62 74 R(n vo) mm) X X X M ./\96' 92 REV) x X 44 i R Re s Evan? ELECTRIC PNEUMATIC SHIFT CONTROL CROSS REFERENCE TO RELATED APPLICATION This application is related to that disclosed and claimed in the application of Robert G. Luft entitled DUAL STATION TRANSMISSION CONTROL, Ser. No. 52,938 now US. Pat. No. 3,679,018 filed July 7, 1970.

BACKGROUND AND SUMMARY OF THE INVENTION The aforementioned patent fully describes some of the reasons for and necessity of an arrangement for controlling a transmission from two different operator stations. It is an object of this invention to provide a dual station control for a transmission which is simple, inexpensive and reliable, and in which the number and length of fluid conduits are minimized, the use of a plurality of common standard components is maximized, and the need for specially constructed cams and the like is eliminated. It is also an object of this invention to provide a control means having the aforementioned attributes for control of a transmission, and especially a transmission of the automatic type, from a single station.

These and other objects and many of the attendant advantages of the present invention will become more readily apparent upon a perusal of the following description and the accompanying drawing, wherein the sole figure is a schematic diagram of a transmission control incorporating the invention.

DESCRIPTION OF A PREFERRED EMBODIMENT Referring now to the drawing, there is shown a front station or operator compartment 12 and a rear station 14. A selector switch 16 is provided in the front station 12 and is connected with a source of electrical energy, such as a battery 18, by means of conductor 20, The switch 16 is of the two-position type and in its FRONT position, is illustrated in the drawing, connects the battery 18 with a conductor 22. The conductor 22 communicates with a transmission control switch means 24 which comprises seven single pole single throw switches. These switches are closed by a cable control means 26 which is actuated by a manual handle 28 located in the front station l2.

Considering now the individual switches, the N switch is closed when the handle 28 is positioned in its neutral position and directs electrical energy to the starter circuit through the conductor 30. When the R switch is closed by moving the handle 28 to its reverse position, electric energy is directed through

conductors

32 and 80 to actuate the solenoids of valve 34 and through

conductors

36 and 38 to actuate the solenoids of

valves

40 and 42 respectively. These

valves

34, 40 and 42 are spring biased to the position shown in the drawing and are shifted by their solenoids to direct air pressure from the reservoir 44 to the respective ports A, B and D of the shift cylinder 46. The shift cylinder is of the multiposition type having a plurality of chambers to which air pressure may be selectively directed to control the degree of extension of the rod 48 in the cylinder, and may, for example be of the type soldby Westinghouse Air Brake Co. and identified as their 2X3M4-N-2B Cylinder Assembly.

The rod 48 of the cylinder is linked to a bellcrank 50, which in turn is connected to gear shift arm 52 of the transmission 54 by means of link 51. The gear shift arm 52 is connected to a conventional type of transmission conditioning mechanism, such as a valve spool for directing hydraulic pressure to the proper clutch packs within the transmission for achieving the designated direction and speed range gear changes. For reverse gear the pressuring of ports A, B and D will extend the rod 48 of the cylinder 46 the proper amount to move the gear shift arm 52 to condition the transmission for low speed in a reverse direction.

When the handle 28 is moved to its 1 position for low gear in a forward direction the switch identified as 1 will be closed. Electrical energy will be transmitted through the

conductors

56 and 58 to actuate the solenoids of

valves

60 and 62 respectively. Energizing the solenoids causes the

valves

60 and 62 to shift against the bias of their springs directing air pressure from the reservoir 44 to the port E of the shift cylinder 46 and to the port F of the slave cylinder 64. The rod 66 of the slave cylinder 64 includes a plunger 68 which is capable, in its extended position, of moving the throttle valve arm associated with the transmission 54, which is of the automatic type in that it will automatically shift to higher gears as engine speed increases and the load encountered permits, and will shift down as the engine throttle control is moved to accelerate the engine or when load encountered lugs the engine down. The rod 66 and its plunger 68 is normally biased to a retracted position, but when air pressure is introduced through port F the rod 66 is extended causing the throttle valve arm 70 to be moved whereby the transmission 54 receives the same signal or indication it would if the operator were attempting to rapidly increase engine speed. Hence, the transmission 54 will be prevented from shifting up, i.e., shifting from first gear to a higher gear. The air pressure directed to port E of the shift cylinder 46 will have shifted the rod 48 to position the arm 52 at the position indicated l-2 so that the transmission is conditioned for first gear in a forward direction, with the capability of shifting to second gear but for the fact that the throttle valve arm 70 has been moved to prevent the automatic shift to second gear.

When the handle 28 is moved to a position to close the switch indicated l-2, electrical energy will be directed through conductor 72 causing the solenoid of valve 60 to be actuated. Valve 60 will be shifted directing air pressure from the reservoir 44 to the port E. The transmission gear shift arm 52 will be positioned as previously described at the 1-2 position. Now, however, the diode 74 will prevent actuation of the solenoid of valve 62 and the plunger 68 will be retracted by the spring biased slave cylinder 64 and the throttle valve arm 70 can perform its normal function, permitting the transmission 54 to shift to second gear when conditions permit.

When the handle 28 is positioned to close the switch indicated as 3-4, the conductor 76 is energized causing the solenoid of valve 60 to be actuated. Simultaneously, the diode 78 permits the conductor 80 to be energized and the solenoid of valve 34 actuated. Air pressure is thereby directed to the ports A and E of the shaft cylinder 46. The rod 48 will be extended on a point to position the arm 52 at the 3-4 position. The

transmission 54 will therefore be conditioned to operate in either third or fourth gear in a forward direction depending upon conditions. The

diodes

74, 82 and 84 prevent any of the other solenoids being actuated.

Closing the switch indicated as 3-5 by moving the handle 28 energizes the conductor 86 and actuates the solenoid of valve 40. The diode 82 also permits the solenoid of valve 60 to be actuated and diode 78, permits the solenoid of valve 34 to be actuated. Air pressure is, therefore, directed to ports A, B and E of shift cylinder 46 and its rod 48 moved to position the arm 52 as indicated at 3-5. The transmission 54 will thereby be conditioned to automatically shift to any one of third, fourth or fifth gears on a forward direction depending upon conditions.

Similarly, movement of handle 28 to its 3-6 position will close the switch indicated as 3-6, causing the conductor 88 to be energized and the solenoid of valve 42 to be actuated. Air pressure is directed to port D of the shift cylinder 46. The rod 48 will be extended to position the arm 52 at 3-6. The transmission 54 will be conditioned to automatically shift to any one of third, fourth, fifth and sixth gears, conditions permitting, in a forward direction.

The station selector switch 16, when moved to its rear position, isolates the switch 24 from the battery 18 and connects the conductor 20 with the conductor 90 leading to the wiper of a switch 92 in the rearstation 14. The front station 16 is rendered inactive and the rear station 16 now has control over the transmission 54. In order to drive the vehicle in a forward direction from the rear station 14 the switch 92 is moved to its R position. The conductor 90 is thereby connected with a conductor 94 which connects with the conductor 32. Energizing conductor 32 functions to actuate the solenoids of

valves

34, 40 and 42 which conditions the transmission 54 for reverse drive as described previously. Movement of the switch 92 to its 1 position will cause the vehicle to move in a reverse direction with respect to the rear station. The conductor 90 is connected with a conductor 96 which connects with the conductor 56. Energizing the conductor 56 will cause the solenoids of

valves

60 and 62 to be actuated which conditions the transmission 54 for forward drive as described previously.

The diodes 98 and 100 serve to insure isolation of the switch 92 from the battery 18 whenever the selector switch 16 is in its FRONT position. Similarly, the

diodes

102, 104, 106 and 108 insure that the switch 24 can exercise no control over the transmission 54 whenever the selector switch 16 is in its REAR position. The remaining diodes within the circuit means, indicated generally at 110, are for the purpose of insuring that only the desired ones of the solenoids, as previously described, are actuated. These diodes are conventional and consideration need be given only the power transmission requirements of each to fulfill optimum costperformance design criterion.

While a preferred embodiment of the present invention has been illustrated and described herein, it is to be understood that various changes and modifications may be made without depending from the spirit of the invention as defined by the scope of the appended claims.

What is claimed is:

l. A control means for a transmission having a shift arm capable of being moved between a plurality of positions, each of said positions conditioning the transmission for a given direction and speed range, comprising:

a multiposition shift cylinder operatively connected to the shift arm for moving said arm to its said positions;

said cylinder having a plurality of ports which, when selectively pressurized, cause said cylinder to move to each of its multipositions;

a solenoid-actuated valve communicating with each of said ports and capable, when energized, of directing fluid pressure thereto;

circuit means including a first manually actuated switch means for selectively energizing certain ones of said valves to extend said cylinder to a desired one of its multipositions.

2. A control for a transmission according to claim 1 and further comprising;

a second manually actuated switch means for selectively energizing at least a portion of said circuit means; and a selector switch for selectively energizing one of said first and second switch means. 3. A control means according to claim 2, wherein the transmission is capable of automatically shifting from a high gear to a lower gear under conditions of acceleration, and further comprising:

a throttle valve arm connected with said transmission to condition said transmission for said lower gear under conditions of acceleration;

a fluid cylinder engageable with said arm and movable under the influence of fluid pressure to move and maintain the throttle valve arm in the position it would assume under said acceleration condifluid pressure to said cylinder;

circuit means, including a first manually actuated switch means, for selectively energizing the desired ones of said valves to orient said cylinder to initially 5O condition the transmission for said low gear; and

means operable upon energization of a certain one of said valves to prevent said transmission from shifting to a higher gear.

5. A control according to claim 4 wherein said last mentioned means comprises;

a throttle valve arm connected with said transmission to insure the transmission is conditioned for said low gear under conditions of acceleration;

a fluid cylinder engageable with said arm and movable under the influence of fluid pressure received from said certain valve to move and maintain the throttle valve arm in the position it would assume under said acceleration conditions.

6. A control according to claim 5, and further comprising:

a second manually actuated switch means for selectively energizing at least a portion of said circuit means; and

a fluid cylinder engageable with said arm and movable under the influence of fluid pressure to move and maintain the throttle valve arm in the position it would assume under said acceleration conditions; and means for selectively directing fluid pressure to said cylinder.

Claims

1. A control means for a transmission having a shift arm capable of being moved between a plurality of positions, each of said positions conditioning the transmission for a given direction and speed range, comprising: a multiposition shift cylinder operatively connected to the shift arm for moving said arm to its said positions; said cylinder having a plurality of ports which, when selectively pressurized, cause said cylinder to move to each of its multipositions; a solenoid-actuated valve communicating with each of said ports and capable, when energized, of directing fluid pressure thereto; circuit means including a first manually actuated switch means for selectively energizing certain ones of said valves to extend said cylinder to a desired one of its multipositions.

2. A control for a transmission according To claim 1 and further comprising; a second manually actuated switch means for selectively energizing at least a portion of said circuit means; and a selector switch for selectively energizing one of said first and second switch means.

3. A control means according to claim 2, wherein the transmission is capable of automatically shifting from a high gear to a lower gear under conditions of acceleration, and further comprising: a throttle valve arm connected with said transmission to condition said transmission for said lower gear under conditions of acceleration; a fluid cylinder engageable with said arm and movable under the influence of fluid pressure to move and maintain the throttle valve arm in the position it would assume under said acceleration conditions; and means for selectively directing fluid pressure to said fluid cylinder.

4. A control for an automatic transmission capable of automatically shifting from a low gear to a higher gear comprising: a multiposition shift cylinder operatively connected to and capable of initially conditioning the transmission for said low gear; a plurality of solenoid-operated valves for directing fluid pressure to said cylinder; circuit means, including a first manually actuated switch means, for selectively energizing the desired ones of said valves to orient said cylinder to initially condition the transmission for said low gear; and means operable upon energization of a certain one of said valves to prevent said transmission from shifting to a higher gear.

5. A control according to claim 4 wherein said last mentioned means comprises; a throttle valve arm connected with said transmission to insure the transmission is conditioned for said low gear under conditions of acceleration; a fluid cylinder engageable with said arm and movable under the influence of fluid pressure received from said certain valve to move and maintain the throttle valve arm in the position it would assume under said acceleration conditions.

6. A control according to claim 5, and further comprising: a second manually actuated switch means for selectively energizing at least a portion of said circuit means; and a selector switch for selectively energizing one of said first and second switch means.

7. A control for an automatic transmission driven by an engine, which transmission is capable of shifting from a high gear to a lower gear under conditions of acceleration of the engine, comprising: a throttle valve arm connected with said transmission to condition said transmission for said lower gear under conditions of acceleration; a fluid cylinder engageable with said arm and movable under the influence of fluid pressure to move and maintain the throttle valve arm in the position it would assume under said acceleration conditions; and means for selectively directing fluid pressure to said cylinder.