TECHNICAL FIELD

The present invention relates to vehicle throttle sensors and, more particularly, to an automobile or other vehicle throttle sensor that transmits signals according to the positioning of the engine throttle.

BACKGROUND ART

In order to better control internal-combustion engine operation, it occasionally and more frequently becomes advantageous to determine the status of the engine throttle and whether or not it is open or closed. One such motivation for the detection of throttle status arises with the use of the engine's vacuum in order to provide emission-reducing and/or performance-enhancing operations during certain times.

Engine vacuum for internal -combustion engines is often inconsistent and cannot be predetermined or relied upon. For example, when a positive crankcase ventilation (PCV) valve is used to positively ventilate the oil crankcase, the blow-by vapors passing through the crankcase and flowing into the intake manifold through the PCV valve may enhance engine performance and reduce emissions during times of high engine activity (such as when the throttle is open) or may kill the engine during periods of low engine activity (when the throttle is closed). It therefore becomes necessary to detect the status of the engine throttle so as to determine when to best open such a PCV valve. Of course, certain enhancements of such PCV valves may be implemented in line with same.

It can be seen, therefore, that providing an engine throttle sensor switch can enhance the operation, performance, and possible emission-reduction activity of an internal-combustion engine.

DISCLOSURE OF INVENTION

The present invention resides in an engine throttle sensor switch that uses a pair of opposing springs in order to mediate the switching on or switching off of a microswitch. The microswitch is encased in a housing and may take several forms. Such forms of the microswitch include default-on and default-off switches as well as

clockwise, counterclockwise, and linear potentiometers. From these available variations of the microswitch and variations of the opposing springs, a number of signals may be selectively generated in order to provide status information regarding the open or closed nature of the engine throttle. Furthermore, the engine throttle sensor switch is easily installed, greatly enhancing the utility as indicated in more detail below.

BRIEF DESCRIPTION OF DRAWINGS

Figure 1 is an exploded isometric view of the engine throttle switch of the present invention. Figure 2 is a cross-section view of the present invention.

Figure 3 is an exterior isometric view of the present invention when assembled.

Figure 4 is a cross-section view of the present invention using a linear potentiometer.

MODEtSi FOR CARRYING OUT THE INVENTION

The present invention provides an engine throttle sensor switch for use in determining the open or closed nature of the engine throttle, allowing (among other things) devices relying upon engine vacuum to operate in coordination with determine the detected level engine activity. Referring now to Figure 1 , the engine throttle sensor switch 10 of the present invention is shown in exploded view. A 90° bracket 12 may be fixed to a stationary object as by a nut and bolt, screw or other means of attachment. A first bracket leg 14 has a generally central hole 16 through which such nut and bolt fixing means (not shown) may be used to attach the 90° bracket 12 to a stationary object local to a portion of the engine throttle cable (not shown). A second bracket leg 18 extends generally peφendicular to the first bracket leg 14; however, it is contemplated that other angular relationships between the first and second bracket legs 14, 18 may be advantageously implemented. The second bracket leg 18 also has a generally central hole 20 through which one side of an S-hook 22 engages the 90° bracket 12. The

other side of the S-hook 22 may engage a D-ring 24 or other swivelable attachment means.

The D-ring 24 engages oppositely opposed holes 26, 27 at a distal end of the switch housing 28. Switch housing 28 may be made of plastic or other durable material able to withstand the environment within the close confines adjacent an internal combustion engine. Such confines often find dirt, oil and other grime collecting in every available location. The switch housing 28 and is preferably cylindrical in shape, having a hollowed-out portion for use as is described in more detail below. Beyond the switch housing holes 26, 27 allowing engagement by the D- ring 24, the switch housing 28 also has a wiring aperture 30 through which wires may pass from the interior of the switch housing 28 to the exterior thereof.

A microswitch 36 may be inserted into the cavity 38 of the switch housing 28. The interior of the switch housing 28 may be formed to conform with the exterior of the microswitch 36, as is shown in Figure 2. The construction in operation of the microswitch 36 is set forth in more detail below. For purposes of explanation, the microswitch is described herein as operating in a certain manner which varies according to the operational characteristics of the microswitch 36.

As shown in Figure 1, the microswitch 36 has a push button 40 coupled to the microswitch chassis 42. As contemplated in one embodiment of the present invention, the microswitch 36 is on when the push button 40 is depressed. As can be seen in Figure 2, the depression of push button 40 serves to connect the two terminals 44, 45 allowing a signal to be conducted or transmitted between terminals 44, 45. As shown in Figures 1 and 2, the terminals 44, 45 may be connected by wires 46 to a two-pole plug 48. The two-pole plug 48 serves as an adaptor or connection means to devices which utilize the throttle position in order to determine their operation.

As shown in Figures 1 and 2, a pull rod 50 serves to engage or withdraw from the push button 40 of microswitch 36. The pull rod 50 has a hemispherical head 52 centrally attached to the pull rod shaft 54. The pull rod shaft 54 extends a significant length away from the hemispherical head 52 and is encircled by a compression spring 60. When threaded upon the pull rod shaft 54, the travel of the compression spring

60 is halted by the flat rear surface 62 of hemispherical pull rod head 52.

As shown in Figure 2, the pull rod 52 in compression spring 50 fits within a switch end cap 64. The switch end cap 64 is hollow and generally cylindrical in nature. A cylindrically angular protrusion 66 extends out coaxially from the switch end cap 64 and fits into a recess 68 at the mouth of switch housing 28. The switch end cap's end opposite the protrusion 66 is perforated by a centrally located hole 70 through which the pull rod shaft 54 may pass.

At the opposite end of the pull rod shaft 54 to the hemispherical head 52 is a small hole 72 travelling centrally through shaft 54. When the pull rod 50 is threaded through the compression spring 60 within the switch end cap 64, the pull rod shaft hole 72 is exposed and made available as it passes through the central switch end cap hole 70.

When the pull rod shaft hole 72 passes through the switch end cap hole 70, a free end 80 of extension spring 82 may be threaded through the pull rod shaft hole 72, coupling the extension spring 82 to the pull rod 50 as well as the compression spring 60. The other free end 84 of extension spring 82 may be connected to a hole

86 present at an end of a spring anchor 88.

A spring anchor 88 may be connected to the throttle or accelerator cable (not shown) by compressing or pinching the cable between itself and an anchor base 90, the spring anchor connected to the anchor base by one or more screws 92. The spring anchor and anchor base are seen as providing the universal clamp that may engage cables or linkages from 1/16 to 1/2" in diameter. When the 90° bracket 12 and the spring anchor 88/anchor base 90 are attached to their respective positions, and when the engine throttle sensor switch of the present invention intermediates these two fixed points, the status of the throttle/accelerator may be determined and indication given as to the open or closed nature of the throttle/accelerator.

Turning now to Figure 2, it can be seen that when the compression spring 60 and the extension spring 82 are in their most natural and relaxed state, the compression spring 60 presses upon the flat rear surface 62 of hemispherical head 52 in order to press it against the push button 40 of microswitch 36. This engages microswitch 36 and allows it to conduct between its terminals 44, 45. As the

accelerator or throttle is depressed or moved to feed more fuel into the engine, the spring anchor 88 and anchor base 90 are pulled away from the 90° bracket 12. This movement of the clamp 92 made up of the spring anchor 88 and anchor base 90 causes the extension spring 82 to stretch. The stretching of extension spring 82 starts to pull upon the pull rod shaft 54 as the compression spring is attached to the pull rod shaft 54 through the small hole 72 by the extension spring end 80. As the universal clamp 94 moves farther away from the 90° bracket, the force upon the pull rod shaft 54 increases with the increasing stretch or displacement of extension spring 82. The pulling of extension spring 82 is balanced by the compression of compression spring 60 upon the hemispherical pull rod head 52. As the universal clamp 94 pulls farther away, at some point the force pulling the pull rod 50 towards the universal clamp 94 created by the extension spring 82 overcomes the push of compression spring 60 upon the hemispherical pull rod head 52 towards the microswitch push button 40. At that point, the hemispherical pull rod head 52 begins to disengage from the microswitch push button 40 until the hemispherical pull rod head 52 is free and clear of the microswitch push button 40. The initial state of microswitch 36 is then changed and the connection between terminals 44, 45 may be cut. This change in the state of microswitch 36 is then transmitted via wires 46 to the two-pole plug 48.

It can be seen that the point at which the pull rod 50 disengages the microswitch 36 is controlled by the relative strength between the compression spring

60 and the extension spring 82. By judicious choices of these spring strengths, the point at which the pull rod 50 disengages the microswitch 36 may be controlled. Note should be taken that the switch housing 28 and the switch end cap 64 are held stationary with respect to the 90° bracket through the S-hook 22 and D-ring 24. Figure 3 shows an isometric view of the engine throttle sensor switch at the present invention when fully assembled in its initial position.

As mentioned above, judicious choices may be made of microswitch 36 so that it is initially off and turns on or, as in the case with potential PCV valves, the microswitch may initially be on as button 40 is depressed, with the microswitch turning off as the pull rod 50 is retracted from the microswitch 36. In an alternative embodiment to the present invention, the microswitch 36 may be substituted by a

potentiometer or other small variable resistor.

As shown in Figure 4, a linearly variable resistor or potentiometer 102 may be used in the place of the microswitch 36. A flange 104 may retain the potentiometer 102 within the switch housing 28. The variable resistor 102 has a slider 106 which may be displaced through a distance appropriate for the device. The slider 106 follows the hemispherical head 52 of the pull rod 50. With the motion of the pull rod 50, the slider 106 will move, thereby altering the resistance of the variable resistor 102.

With the use of the variable resistor 102, an even higher degree of throttle status detection may be achieved through the present invention. The two-pole plug may be attached to the two terminals 44, 45 of the potentiometer 102 in order to transmit the signal therefrom.

As with the microswitch 36, the potentiometer 102 may be initially off or on when the slider 106 is depressed by pull rod 50. As pull rod 50 is withdrawn from the switch housing 28, the potentiometer 102 correspondingly increases or decreases the signal transmission between its terminals 44, 45. That is, the potentiometer 102 may increase signal transmission with either inward or outward displacement of the slider 106 according to propitious design choice.

While the present invention has been described with regards to particular embodiments, it is recognized that additional variations of the present invention may be devised without departing from the inventive concept.

INDUSTRIAL APPLICABILITY

The present invention may be used industrially in conjunction with internal combustion engines to indicate throttle status