GB1590268A - Choke control device for an internal combustion engine - Google Patents

Description

(54) CHOKE CONTROL DEVICE FOR AN INTERNAL COMBUSTION ENGINE (71) We, FIAT AUTO SpA, an Italian Joint Stock Company of 200 Corso Giovanni Agnelli, Turin, Italy, do hereby declare the 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 particularly described in and by the following statement:- The present invention relates to a choke control device for an internal combustion engine, particularly in a motor vehicle.

It is known that, when starting the carburettor of an internal combustion engine has to be capable of supplying an extremely rich mixture, for the purpose of compensating for condensation which easily forms on the cold walls of the manifold tubing and the cylinders.

To meet these requirements an extra butterfly valve is provided in the carburettor, or alternatively a special starter which consists of a small individual carburettor provided in a by-pass arrangement.

Both of these systems, known as choke systems, are arranged to operate, when the engine is being started, by means of a manual control, consisting of an operating cable which is pulled by the driver by means of a knob.

The knob has has to be fixed in the position where it is effective, and is therefore rotated in order to locate with reference notches, this being an operation which can easily be forgotten by the operator which causes it not to fulfill the function for which it is intended.

A further serious disadvantage of the knob is the fact that it projects from the lower part of the instrument dashboard, with possible serious risk to the safety of the driver, owing to the fact that it could provide a fixed obstacle against which the knee, for example, of the driver could strike, especially in the case of a frontal collision of the vehicle.

An embodiment of the invention to be described herein eliminates the above disadvantage of the fixed obstacle and consequently reduces the danger of lesions to the persons travelling in the motor vehicle thus complying with international safety standards. Such embodiment is particularly functional, can be handled easily and rapidly and is at the same time of simple and economcal construction.

In accordance with this invention, there is provided a choke control device for an internal combustion engine, comprising a one-piece plastics member providing both a lever portion and a mounting portion for fixing rigidly to a support, the lever portion being pivotable relative to the mounting portion about a reduced-thickness junction between said lever and mounting portions, the lever portion being provided with a projecting tongue and being arranged to locate in at least one selected position relative to the mounting portion by engagement of notches on the tongue (or on said mounting portion) with teeth on said mounting portion (or on said tongue).

The embodiment to be described herein has a high operating efficiency and a long service life, owing to the particular shaping of the one-piece plastics member.

Said embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: FIGURE 1 is a side view of a choke control device according to the invention when mounted on a vehicle.

FIGURES 2, 3 and 4 show constructional details of the one-piece plastics member of the choke control device, said details being shown partially on an enlarged scale in each of these Figures; and FIGURE 5 is a partial cross-section according to the line V-V of Figure 4.

With particular reference to Figure 1, a box of a heater of a vehicle is shown located on the instrument dashboard and adjacent to the steering column for the steering wheel.

Of said box, two walls 1,2 can be seen, which are spaced from each other and joined by means of the continuous shaped portion of a further inclined wall 3. The cable 4 for choke control extends from wall 2 and is housed in protective sheath 5 and slides in sleeves 6 and 7.

Of the two sleeves the one which is indicated by 6 is located internally with respect to wall 2 whilst the one indicated by 7 is located externally with respect to the same wall 2.

The choke control device comprises a onepiece plastics member comprising a lever portion 8, which is curved at one of its ends 9, and a mounting portion 10 joined to the lever portion at its opposite end. The mounting portion is folded relative to the lever portion, against the elasticity of the plastics material, at their junction point 10a of reduced thickness. In Figure 2 the portion 10 can be seen before it has been folded over.

Screws 11 are provided in suitable holes in mounting portion 10 for connecting the lever portion 8 to the inclined wall 3 of the heater. Still with reference to mounting portion 10 and in particular in a hole 12 therein, a tongue 13 projecting from the lever portion is seated, being further housed in a hole 14 of wall 3.

The tongue 13, furthermore, is provided with a series of notches 15 which are spaced with respect to each other, whose depth can be seen in Figure 3 and which are arranged for engagement, with a slight interference fit, owing to the elasticity of the plastics material, in a pair of teeth 16 which are formed in hole 12 of the mounting portion 10 and which are indicated in Figure 5.

Below the tongue 13, the lever portion 8 is formed with a hook 17, which connects an end 18 of cable 4 which acts on the carburettor.

Figure 1 shows the choke control device in its position for which the choke is inoperative. When use of the choke is required, the operator, by acting on end 9 of the lever portion 8, causes the lever portion to swing to the position shown by dashed lines and consequently exercises a pulling force on cable 4, the end of which is indicated by 181.

The lever portion becomes securely located in the fully-open position of the choke, owing to the upper notches 15 which engage in the teeth 16 of mounting portion 10 and at the same time these become detached from the lower notches 151.

The use of the intermediate notches 1511 allows for semi-opening of the choke.

Mounting portion 10 has been shown connected, by way of example, to the box of the heater but can instead be fixed directly to a wall of the dashboard or other accessories which are located on the dashboard itself but in each case where there is continuity of the surface shaping, so as to avoid it being a dangerous obstacle to the passenger in the case of harmful impact of the vehicle.

WHAT WE CLAIM IS: 1. A choke control device for an internal combustion engine, comprising a one-piece plastics member providing both a lever portion and a mounting portion for fixing rigidly to a support, the lever portion being pivotable relative to the mounting portion about a reduced-thickness junction between said lever and mounting portions, the lever portion being provided with a projecting tongue and being arranged to locate in at least one selected position relative to the mounting portion by engagement of notches on the tongue (or on said mounting portion) with teeth on said mounting portion (or on said tongue).

2. A choke control device according to Claim 1, in which said notches are elastically and firmly engageable in the teeth as a result of a slight interference fit.

3. A choke control device according to claims 1 or 2, in which the lever portion is provided with a hook for connection to a cable acting on the carburettor.

4. A choke control device substantially as herein described with reference to the accompanying drawings.

5. An internal combustion engine, or a vehicle having an internal combustion engine, having mounted thereon a choke control device as claimed in any preceding claim.

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

Claims (5)

**WARNING** start of CLMS field may overlap end of DESC **. housed in protective sheath 5 and slides in sleeves 6 and 7. Of the two sleeves the one which is indicated by 6 is located internally with respect to wall 2 whilst the one indicated by 7 is located externally with respect to the same wall 2. The choke control device comprises a onepiece plastics member comprising a lever portion 8, which is curved at one of its ends 9, and a mounting portion 10 joined to the lever portion at its opposite end. The mounting portion is folded relative to the lever portion, against the elasticity of the plastics material, at their junction point 10a of reduced thickness. In Figure 2 the portion 10 can be seen before it has been folded over. Screws 11 are provided in suitable holes in mounting portion 10 for connecting the lever portion 8 to the inclined wall 3 of the heater. Still with reference to mounting portion 10 and in particular in a hole 12 therein, a tongue 13 projecting from the lever portion is seated, being further housed in a hole 14 of wall 3. The tongue 13, furthermore, is provided with a series of notches 15 which are spaced with respect to each other, whose depth can be seen in Figure 3 and which are arranged for engagement, with a slight interference fit, owing to the elasticity of the plastics material, in a pair of teeth 16 which are formed in hole 12 of the mounting portion 10 and which are indicated in Figure 5. Below the tongue 13, the lever portion 8 is formed with a hook 17, which connects an end 18 of cable 4 which acts on the carburettor. Figure 1 shows the choke control device in its position for which the choke is inoperative. When use of the choke is required, the operator, by acting on end 9 of the lever portion 8, causes the lever portion to swing to the position shown by dashed lines and consequently exercises a pulling force on cable 4, the end of which is indicated by 181. The lever portion becomes securely located in the fully-open position of the choke, owing to the upper notches 15 which engage in the teeth 16 of mounting portion 10 and at the same time these become detached from the lower notches 151. The use of the intermediate notches 1511 allows for semi-opening of the choke. Mounting portion 10 has been shown connected, by way of example, to the box of the heater but can instead be fixed directly to a wall of the dashboard or other accessories which are located on the dashboard itself but in each case where there is continuity of the surface shaping, so as to avoid it being a dangerous obstacle to the passenger in the case of harmful impact of the vehicle. WHAT WE CLAIM IS:

1. A choke control device for an internal combustion engine, comprising a one-piece plastics member providing both a lever portion and a mounting portion for fixing rigidly to a support, the lever portion being pivotable relative to the mounting portion about a reduced-thickness junction between said lever and mounting portions, the lever portion being provided with a projecting tongue and being arranged to locate in at least one selected position relative to the mounting portion by engagement of notches on the tongue (or on said mounting portion) with teeth on said mounting portion (or on said tongue).

2. A choke control device according to Claim 1, in which said notches are elastically and firmly engageable in the teeth as a result of a slight interference fit.

3. A choke control device according to claims 1 or 2, in which the lever portion is provided with a hook for connection to a cable acting on the carburettor.

4. A choke control device substantially as herein described with reference to the accompanying drawings.

5. An internal combustion engine, or a vehicle having an internal combustion engine, having mounted thereon a choke control device as claimed in any preceding claim.