DE8700977U1 - Push rod made of plastic - Google Patents

Description

VOLVO CAR BV,, Steenovenweg 1, NL-5708 HN HELMOND "Push rod made of plastic"

The innovation relates to a push rod for coupling a control element to an element actuated thereby, in particular for coupling the release button on the selector lever handle of a motor vehicle with the lever in the "Park" position.

Such pressure rods have a wide range of applications in technology and a particular type of application is the one mentioned above.

The aim of the innovation is to make available a push rod which is designed in such a way that incorrect assembly between the two parts to be coupled together is impossible _- is lightweight, has a low mass inertia and can be made from inexpensive material, has good vibration and noise damping characteristics and is corrosion-resistant.

This purpose is achieved according to the innovation with the measures specified in the characterising features of the main claim.

A preferred embodiment, which has the advantage of low friction, particularly when guided in a cylindrical bore, is characterized by the measures described in claim 2.

The innovation is explained using the drawing.

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- 2 The drawing shows in

a side view of a push rod, a side view on an enlarged scale of one of the end pieces, a top view of this end piece and a partial side view, a partial longitudinal section of a selector lever

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&Igr;&Ogr; push rod is equipped.

In Fig. 1, a pressure rod 2 is shown in its entirety and this pressure rod consists of an elongated cylindrical part 4 with the two end pieces 6 and 8 designed in a matching manner. The end piece 6 is shown on an enlarged scale in Figs. 2 and 3 and consists of two slightly springy legs 12, 14 protruding from a stop surface 10 and hook-shaped locking elements 16 and 18 protruding radially therefrom.

The two end pieces 6 and 8 are thus suitable for working with receiving openings with a diameter that is slightly smaller than that of the circular stop surface 10 and with a height that is at most equal to the distance from the lower edge of the hook-shaped locking members 16 and 18 to that surface 10.

A special application of this pressure rod is that in which the pressure rod is guided in a cylindrical bore. In this case, the inner diameter of this bore is larger than the outer diameter of the rod part 4 and a number of spherical guides are distributed along its length.

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ring thickenings 20 to 26 are arranged, each of which is provided with recesses 20a to 26a running in the longitudinal direction of the rod 2. This prevents impurities and abraded material from piling up on one of the guide balls and preventing the rod from moving in its longitudinal direction, while the balls simultaneously prevent the pressure rod from bending out, which can therefore have a large length.

Fig. 4 shows how the rod 4 is guided in the bushing 30, which is accommodated in the body 32 of a selector handle for an automobile gearbox, connected to the hinge part 38 which can be rotated about the axis 34 in a support device 36. This hinge part 38 is connected to a transmission element.

In the selector device of an automatic transmission, it is usually ensured that it is not possible to switch from the "neutral" position to the "reverse" position, or from the "reverse" position to the "park" position, for example. For this purpose, a locking device is provided that works together with a suitable locking lever with a movable pivot point, which is actuated by a push button in the selector lever handle for the purpose of unlocking. Fig. 4 shows the use of the push rod 4 for this purpose. From the figure, it can be seen how the upper end piece 6 of the push rod is engaged in the receiving bore 42, which is formed in the cylindrical part 44 of the push button 46, while the lower end piece is engaged in a similar bore, which is formed in the locking

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is engaged by a locking member 47 which cooperates in a manner not specified with a locking lever with a movable pivot point and releases the movement of the hinge part 38 about the pivot point 34 when the button 46 is pressed.

By means of the above-described design of the innovative pressure rod, the advantage is achieved that HaR H &ogr; Y* &agr; &eegr; iinifi rhti &pgr;&ohgr; Mnnfano &eegr;&igr; rht mn n~\ -&iacgr;&eegr; h -ic+ »&igr;&eegr;&Agr;

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assembly can be carried out more quickly. The presence of the spherical thickenings ensures optimal guidance in the bore.

Claims (1)

"Plastic push rod" 10 Push rod for coupling an operating element to an element actuated thereby, in particular for coupling the locking button in the selector handle of an automobile gearbox to a locking element, characterized in that the push rod (2) made of plastic is provided at both ends with an identical locking end piece (6, 8), consisting of at least two resilient legs (12, 14) projecting axially from a stop surface (10), which are provided at the free end with radially projecting hook-shaped locking elements (16, 18) for interacting with the edge of a receiving opening in the operating element or in the actuated element. 20 Pressure rod according to claim 1, characterized in that the outer diameter of the pressure rod (2) to be guided in an elongated cylindrical bore is smaller than the inner diameter of the bore and that the Pressure rod (2), along the length of which there are at least two spherical guide thickenings (20...) which are provided with recesses (20a...) running in the longitudinal direction of the rod (2).