Solenoid electrical connection and electrical spring terminal therefor

A right angle configured spring contact terminal for a solenoid with a hooked end adjacent a region of contra-curvature adapted for contact with an electrical contact on an external mounting member. The opposite end is bifurcated for plug-in connection to a solenoid coil terminal receptacle. A plastic/elastomeric insulator is overmolded adjacent the right angle bend for inserting the hooked end in an aperture in the body structure upon which the solenoid coil is mounted.

BACKGROUND OF THE INVENTION

The present invention relates to electrical connector terminals and particularly terminals for use with solenoid operators and more particularly for providing energization of the solenoid by making electrical connection through a mechanical operating member of the operating system into which the solenoid is assembled. An example of such a device is a solenoid operated dampening or flow restricting valve associated with an hydraulic shock absorber for a vehicle suspension wherein a mechanical member associated with the moveable parts of the shock absorber provides electrical contact for energizing the solenoid operated dampening valve in response to a control signal. In such shock absorber applications, the solenoid operated valve is operable to restrict the flow of hydraulic fluid in the shock absorber to alter the rate of flow and thus the dampening in the shock absorber. Such arrangements are employed in motor vehicle suspensions where it is desired to alter the stiffness or dampening rate of the shock absorbers in real time or on a running basis in response to changes in road conditions or driving patterns.

Heretofore in such vehicle suspension shock absorber application problems have been encountered with undesired movement of electrical contacts providing current to the solenoid coil from the deformation and relative movement between the shock absorber components which has resulted in permanent deformation of the contacts and early failure of the contacts. This problem has been particularly prominent in installations where the solenoid contact terminal is disposed in the attachment fitting portion of the solenoid valve body which is attached to the structural member such as the piston rod of a motor vehicle shock absorber. Heretofore, in solenoid valves for such installations, the contact terminal has been inserted through an aperture in the solenoid operated valve body such that upon assembly of a solenoid coil thereover the terminal makes a bayonet style or plug-in connection with a mating terminal on the solenoid coil. The electrical terminal has been provided with an insulator thereabout for insertion into an aperture in the attachment portion of the valve body and electrical isolation of the terminal from the valve body, which is typically formed of metal.

In such an aforesaid installation, it has been found extremely difficult to provide adequate deflectability or sufficiently low lateral spring rate of the electrical terminal to accommodate relative movement of the structural components because of the minimum space available for the formation of the electrical terminal in the mounting on the valve body. Thus, it has long been desired to provide an electrical terminal in a solenoid which is capable of withstanding the deformation without premature failure when subjected to high inertial loading caused by relative movement of the components of the systems in which the valve is installed.

BRIEF SUMMARY OF THE INVENTION

The present invention provides an electrical terminal adapted for external contact and connected by bayonet or plug-in connection with a solenoid coil when the terminal is installed in a valve operated by the solenoid. The terminal is installed in the attachment portion of the valve body for connection therewith upon assembly of the body into the system to be controlled by the valve, such as a shock absorber.

The present invention provides a spring type electrical terminal for mounting through an aperture and having a right angle configuration for effecting a plug-in connection thereto by a coil. The spring terminal has a hooked or folded end capable of absorbing contact by an external contact member upon installation in a structure, such as a shock absorber piston rod contact. The region of the terminal adjacent the hooked or folded end is formed with a contra curvature which cooperates with the hooked portion for lowering the lateral spring rate and absorbing deflection by the external contact. Insulating material is disposed over the right angle bend for enabling mounting of the terminal through an aperture in a metal valve body. In the presently preferred practice, the insulating material is plastic molded over the terminal and alternatively may be formed of or may include elastomeric material.

DETAILED DESCRIPTION OF THE INVENTION

Referring toFIGS. 1 through 3, the terminal assembly of the present invention is indicated generally at10and includes a deflectable terminal member formed of a strip of preferably spring tempered material indicated generally at12.

In the presently preferred practice, strip12has a relatively thin rectangular shape in transverse section. The strip may be formed of a continuous length of relatively thin material having a generally flat transverse section. The strip12may be formed of material consisting essentially of copper.

Terminal member12has a bifurcated end14formed generally at right angles to the central portion of the terminal member12which bifurcated end14is adapted for bayonet or plug-in type connection thereto. The member12has a hook or folded portion16formed in the end thereof remote from bifurcation14; and, the hook preferably has the open end thereof formed in a straight or planar configuration as denoted by reference numeral18. The member12has a region indicated generally at20which is formed in contra curvature e.g. that has a reversal of curvature therein or S-shape, which portion20in conjunction with hook16provides for improved deflectability or lowered lateral spring rate for the terminal member12.

The portion of the member12between contra curvature20and the bifurcated end14has a right angle bend22which has an insulator24formed thereon preferably by overmolding. The insulator24is preferably formed of plastic material but alternately may be formed of or may include elastomeric material. The insulator24has the end portion thereof adjacent contra curvature20provided with an annular taper26to facilitate installation as hereinafter will be described. In the presently preferred practice, the insulator24has an annular rib28formed thereon with a plurality of tapered deformable lugs adjacent thereto and spaced circumferentially thereabout to facilitate installation and retention.

Referring toFIG. 4, the terminal assembly is shown installed in an aperture32formed in a valve body34by insertion of the hooked end of the terminal through the aperture and engaging the sides of the aperture with the rib28and lugs30by compression thereof, thereby frictionally retaining the terminal assembly in the aperture32. The hook16and straight portion18extend into a threaded bore36formed in the valve body. In operation, the hook is deflected to close and move laterally to the position shown in dashed outline inFIG. 4upon being contacted by the end of an electrical conductor40extending through external member38threadedly engaging bore36as shown in dashed line in FIG.4. In the present practice of the invention member38is the piston rod of an hydraulic shock absorber, but may alternatively be any structural mounting member as for applications other than shock absorbers.

Upon assembly of a coil46over body34, the bifurcated portion14of the terminal12is engaged in plug-in arrangement with a corresponding electrical terminal receptacle44provided with the solenoid coil46.

The present invention thus provides a unique electrical terminal assembly which is capable of being installed through an aperture in a solenoid operated valve and extending into a limited space for making electrical contact with an external contact on an attachment structure engaging the solenoid valve. The terminal strip of the present invention is overmolded with insulating material and the strip has a region of contra curvature adjacent a hook shaped contact end for lowering the stiffness or lateral spring rate of the terminal. One end of the strip is bifurcated for plug-in connection to a solenoid coil on the valve body.

The present invention thus provides a unique and relatively low cost terminal contact for insertion in a valve body and for plug-in connection with the solenoid coil upon assembly to the valve body.

Although the invention has hereinabove been described with respect to the illustrated embodiments, it will be understood that the invention is capable of modification and variation and is limited only by the following claims.