GB1600132A

GB1600132A - Engine control linkage

Info

Publication number: GB1600132A
Application number: GB455577A
Authority: GB
Original assignee: Howard Machinery Ltd
Current assignee: Howard Machinery Ltd
Priority date: 1978-05-04
Filing date: 1978-05-04
Publication date: 1981-10-14

Description

(54) ENGINE CONTROLLINhAGE (71) We, HOWARD MACHINERY LIMITED, a British Company of Saxham, Bury St. Edmunds, Suffolk, England do hereby declare this invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be described in and by the following statement:- This invention relates to engine control linkages and in particular to remote control linkages for internal combustion engines whereby an engine cut-out function can be combined with another engine control function.

With some internal combustion engines particularly relatively small engines for use on horticultural or gardening implements it is necessary to earth the electrical ignition system when the engine is to be stopped after use. This may be achieved by the use of a conductor connected to the engine block and arranged to be movable to make contact with the contact breaker points. Alternatively for a remote control arrangement an earthing circuit may be completed adjacent the control handle.

An object of the invention is to provide means for stopping internal combustion engines remotely from the engine which is reliable in operation and which is combined with means for operating another control function of the engine.

According to the invention an internal combustion engine control linkage comprises a cable element arranged to be extendable with one end adjacent an internal combustion engine and the other end remote from the engine, the cable element having a central control rod or wire of electrically conductive material, at least one electrically conductive member which is electrically insulated from the control rod, and an outer covering of electrically insulating material located about said member, the control rod being movable longitudinally of the cable element and being connectable to effect an engine control function, the linkage further comprises operating means remote from the engine for effecting said movement of the control rod, means for selectively electrically connecting the control rod and the electricity conductive member adjacent the operating means, means for electrically connecting an earthing member to the control rod or to the electrically conductive member, and means for connecting an electrical ignition member to the electrically conductive member or to the control rod respectively, the arrangement being such that the linkage can be operated to interrupt engine ignition and thereby stop the engine.

Preferably the operating means and the means for electrically connecting the control rod and said member are constituted by pivotable lever means and the lever means is arranged to effect electrical connection between the control rod and the electrically conductive member at a predetermined point at one end of its travel and said predetermined point is reached after the lever means has ceased to influence said engine control function, conveniently the electrical ignition member is the low tension supply for the engine ignition system.

Further features of the invention will appear from the following description of an embodiment of the invention given by way of example only and with reference to the drawings in which: Fig. 1 is a part sectional elevation of a control linkage according to the invention, Fig. 2 is a diagram showing the electrical circuit brought about by the linkage of Fig.

1, Fig. 3 is a section through one form of cable for use with the linkage of Fig. 1, and Fig. 4 is a section through another form of cable to that of Fig. 3.

The described embodiment is particularly intended for use with a hand-controlled, wheel mounted, rotary cultivating machine (not shown) which includes an internal combustion engine mounted on a frame to drive a pair of wheels and an output shaft through gearing, the output shaft driving a rotary shaft on which rotary implements of various forms can be carried.

The engine is a single cylinder spark ignition engine with a manual starting mechan ism, and the throttle control clutch and the gear change are controlled from the end of a handle extending upwards away from the machine frame for the operator to hold the handle at its end remote from the engine and frame.

Referring to Figs. 1, 2 and 3 of the drawings in which part of the handle 10 is seen, a cable 11 passes between the engine and the upper end of the handle 10, the cable being of a form (see Fig. 3) having a hollow core 12 in which is movably located a throttle control rod 13 which is of electrically conductive material and extends from a connecting member 14, connected to a throttle control mechanism (not shown) of known form, to a two-armed throttle control lever mounted on the handle 10. Around the control rod is an annular member 17 of electrically insulating material defining the hollow core 12 and a spirally wound stranded wire sheath 18 of electrically conductive material surrounds the annular member. The wire sheath is made up of an annular array of wires each of which extends longitudinally of the cable.Around the sheath is an outer lawyer 19 of electrically insulating material which provides a cover for the cab 11.

Through the throttle control mechanism the control rod 13 is electrically connected to the engine block which acts as an earthing member (see Fig. 2) and it will be appreciated that the connecting member 14 lies beyond the end of the cable 11 for connection to the throttle control mechanism. At the lower end of the cable a connection 16 (FiB. 2) is made between the wire sheath 18 and the primary coil windings 30 of the ignition system by a conductor and the cable is clamped by a clamp 20 against movement relative to the engine.

The end of the cable at the upper end of the handle 10 is clamped to the handle and the control rod 13 extends beyond the end of the cable for connection to the pivoted throttle control1ever 15 which is pivoted at 27 and is movable over an arc-shaped support 28 between two throttle control positions A and B corresponding to a high throttle setting as shown in full lines and an idling setting (not shown). The lever 15 is also movable beyond point B at the idling setting after passing through a resistance or gate to an engine cut-out setting 15', shown in chain lines. The throttle control lever is located in a throttle lever assembly 21 which includes an electrical conductor connecting the cable sheath 18 to a stop member 22 against which an arm l5a of the throttle lever bears when in the cut-out position.The throttle lever is electrically connected to the control rod so that an electrical circuit between the sheath and the rod is completed when the lever arm 15a is moved to the cut-out position 15' to engage the stop member 22. In this way the low tension supply is electrically connected to the engine block to short out the electrical charge to the primary coil windings 30 and cause the engine to stop running. This action is simply effected by moving the throttle control lever beyond the idling position B to engage the lever with the stop member 22.

The control linkage of the invention utilises the control cable for another engine control function, in this case throttle control, to effect stopping of the engine thereby obviating the need or a separate control linkage for this purpose.

It will be appreciated that instead of using the throttle control the electrical connection may be obtained through a cable element of another control function.

As an alternative to the control cable described with reference to Fig. 3, the cable may take the form shown in Fig. 4 in which an inner control wire or cable 23 is spaced from an inner sleeve 24 of plastics. The sleeve is surrounded by an annular outer layer 25 of plastics in which are embedded longitudinally extending wires 26, in this case three, but varying in number between three and sixteen depending on the application of the cable. These wires 26 serve the function of reinforcing the cable and also as the electrically conductive members by which engine cut out is achieved as described. It will be appreciated that other forms of cable may also find application with this invention.

WHAT WE CLAIM IS: 1. An internal combustion engine control linkage, comprising a cable element arranged to be extendable with one end adjacent an internal combustion engine and the other end remote from the engine, the cable element having a central control rod of wire of electrically conductive material, at least one electrically conductive member which is electrically insulated from the control rod, and an outer covering of electrically insulating material located about said member, the control rod being movable longitudinally of the cable element and being connectable to effect an engine control function, the linkage further comprising operating means remote from the engine for effecting said movement of the control rod, means for selectively electrically connecting the control rod and the electrically conductive member adjacent the operating means, means for electrically connecting an earthing member to the control rod or to the electrically conductive member, and means for connecting an electrical ignition member to the electrically conductive member or to the control rod respectively, the arrangement being such that the linkage can be operated to interrupt engine ignition and thereby stop the engine.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. ism, and the throttle control clutch and the gear change are controlled from the end of a handle extending upwards away from the machine frame for the operator to hold the handle at its end remote from the engine and frame. Referring to Figs. 1, 2 and 3 of the drawings in which part of the handle 10 is seen, a cable 11 passes between the engine and the upper end of the handle 10, the cable being of a form (see Fig. 3) having a hollow core 12 in which is movably located a throttle control rod 13 which is of electrically conductive material and extends from a connecting member 14, connected to a throttle control mechanism (not shown) of known form, to a two-armed throttle control lever mounted on the handle 10. Around the control rod is an annular member 17 of electrically insulating material defining the hollow core 12 and a spirally wound stranded wire sheath 18 of electrically conductive material surrounds the annular member. The wire sheath is made up of an annular array of wires each of which extends longitudinally of the cable.Around the sheath is an outer lawyer 19 of electrically insulating material which provides a cover for the cab 11. Through the throttle control mechanism the control rod 13 is electrically connected to the engine block which acts as an earthing member (see Fig. 2) and it will be appreciated that the connecting member 14 lies beyond the end of the cable 11 for connection to the throttle control mechanism. At the lower end of the cable a connection 16 (FiB. 2) is made between the wire sheath 18 and the primary coil windings 30 of the ignition system by a conductor and the cable is clamped by a clamp 20 against movement relative to the engine. The end of the cable at the upper end of the handle 10 is clamped to the handle and the control rod 13 extends beyond the end of the cable for connection to the pivoted throttle control1ever 15 which is pivoted at 27 and is movable over an arc-shaped support 28 between two throttle control positions A and B corresponding to a high throttle setting as shown in full lines and an idling setting (not shown). The lever 15 is also movable beyond point B at the idling setting after passing through a resistance or gate to an engine cut-out setting 15', shown in chain lines. The throttle control lever is located in a throttle lever assembly 21 which includes an electrical conductor connecting the cable sheath 18 to a stop member 22 against which an arm l5a of the throttle lever bears when in the cut-out position.The throttle lever is electrically connected to the control rod so that an electrical circuit between the sheath and the rod is completed when the lever arm 15a is moved to the cut-out position 15' to engage the stop member 22. In this way the low tension supply is electrically connected to the engine block to short out the electrical charge to the primary coil windings 30 and cause the engine to stop running. This action is simply effected by moving the throttle control lever beyond the idling position B to engage the lever with the stop member 22. The control linkage of the invention utilises the control cable for another engine control function, in this case throttle control, to effect stopping of the engine thereby obviating the need or a separate control linkage for this purpose. It will be appreciated that instead of using the throttle control the electrical connection may be obtained through a cable element of another control function. As an alternative to the control cable described with reference to Fig. 3, the cable may take the form shown in Fig. 4 in which an inner control wire or cable 23 is spaced from an inner sleeve 24 of plastics. The sleeve is surrounded by an annular outer layer 25 of plastics in which are embedded longitudinally extending wires 26, in this case three, but varying in number between three and sixteen depending on the application of the cable. These wires 26 serve the function of reinforcing the cable and also as the electrically conductive members by which engine cut out is achieved as described. It will be appreciated that other forms of cable may also find application with this invention. WHAT WE CLAIM IS:

1. An internal combustion engine control linkage, comprising a cable element arranged to be extendable with one end adjacent an internal combustion engine and the other end remote from the engine, the cable element having a central control rod of wire of electrically conductive material, at least one electrically conductive member which is electrically insulated from the control rod, and an outer covering of electrically insulating material located about said member, the control rod being movable longitudinally of the cable element and being connectable to effect an engine control function, the linkage further comprising operating means remote from the engine for effecting said movement of the control rod, means for selectively electrically connecting the control rod and the electrically conductive member adjacent the operating means, means for electrically connecting an earthing member to the control rod or to the electrically conductive member, and means for connecting an electrical ignition member to the electrically conductive member or to the control rod respectively, the arrangement being such that the linkage can be operated to interrupt engine ignition and thereby stop the engine.

2. A linkage according to claim 1

wherein the operating means and the means for electrically connecting the control rod and said member are constituted by pivoted lever means arranged to effect said engine control function over part of its operating range and to affect said electrical connection over another part of its operating range.

3. A linkage according to claim 2 wherein the lever means is arranged to effect electrical connection between the control rod and the electrically - conductive member at a predetermined point at one end of its travel and said predetermined point is reached after the lever means has ceased to influence said engine control function.

4. A linkage according to claim 3 wherein movement of the lever means from the engine control function operating range to said predetermined point is resisted.

5. A linkage according to any one of the preceding claims wherein the electrical ignition member is the low tension supply for the engine ignition system.

6. A linkage according to any one of the preceding claims wherein the electrically conductive member is a stranded wire sheath.

7. A linkage according to any one of claims 1 to 5 wherein the electrically conductive member is in the form of longitudinally extending wires embedded in the outer covering of insulating material.

8. An internal combustion engine control linkage substantially as described with reference to Figs. 1 and 2 of the drawings embodying the cable of Figs. 3 or 4.