The present invention relates to a gearshift assembly comprising base, a shift lever having an overmoulded ball portion which is received in a socket fixed in the base, the socket having a sidewall with an inner surface forming part of a sphere to provide a pivotal mounting for the ball portion for pivotal movement of the shift lever over a pivotal movement range, the socket having vertical slots in the sidewall which have parallel vertical side edges and which are open at their upper ends to allow a sidewall portion between adjacent vertical slots to elastically flex outwardly during insertion of the ball portion into the socket, the ball portion comprising a pattern of recesses, each recess having straight side walls.
A gearshift assembly can for example have two shifting gates, for example one for automatic mode and one for manual mode; another example is a gearshift assembly for a manual transmission where a first shifting gate contains the reverse gear, a second shifting gate the first and second gear and so on. The shift lever can be pivoted about a first axis along one of the shifting gates, and about a second axis perpendicular to the first axis between the shifting gates. Such pivotal mounting of the shift lever is typically accomplished by ball portion on the shift lever which is received in a complementary spherical socket that is fixed in a base of the gearshift assembly. The present invention relates to gearshift assemblies in which the ball portion is formed by injection moulding as an overmoulded plastic ball portion on the shift lever. Due to the manufacturing process it is not possible to form the ball portion as full solid ball portion of plastic. One of the reasons is that due to the varying thickness of plastic material, namely the decreasing thickness starting from the equator of the ball portion in both directions, the shrinking of the plastic material would result in a non-spherical surface of the finished moulded plastic portion. To compensate this it is known that the amount of plastic material has to be reduced by including recesses or indentations distributed over the ball portion. In particular it is known that objects to be formed by injection moulding should consist of an arrangement of rather thin walls of uniform thickness to avoid deformation and warping.
In case of forming a ball portion by thin wall injection moulding this leads to a structure as shown in
The socket for receiving the ball portion is open on the upper and the lower side such that the shift lever can extend through the socket, and such that the ball portion can be inserted into the socket by pushing it downwards into the socket. In order to allow such insertion of the ball portion into socket, the socket has to be elastic. In addition the socket is provided with vertical slots extending through the sidewall of the socket from an open upper end of the socket through a part of the vertical extension of the sidewall of the socket. Several vertical slots are distributed around the circumference of the socket. This design allows that each circumferential wall portion between two adjacent vertical slots is able to elastically flex outwardly in order to let the ball portion pass during insertion, whereafter the sidewall portion elastically returns to embrace the ball portion.
In this known design the vertical sidewalls of the recesses are extending parallel to the vertical edges defining the vertical slots in the sidewall of the socket. Due to this alignment of the straight vertical sidewalls of the recesses and of the edges of the vertical slots in the sidewall of the socket it occurs during shift movements that several aligned straight vertical sidewalls of recesses pass vertical edges of the vertical slots of the socket. It has been found that a feeling of a slight jerk or unevenness is experienced when the driver performs such shift movement including movement of the aligned straight vertical side walls of the recesses over straight side edges of the vertical slots in sidewall of the socket.
It is an object of the present invention to arrange a gearshift assembly of this kind in such that shift movements of the shift lever proceed in a smooth and steady manner, without any feedback feeling of jerks or unevenness.
This object is achieved by a gearshift assembly comprising the features of claim 1. Preferred embodiments are set out in the dependent claims.
According to the present invention the pattern of the recesses in the ball portion is arranged such that the sidewalls of the recesses are inclined or disaligned with respect to side edges of the vertical slots over the pivotal movement range of the shift lever. In other words the sidewalls are inclined with respect to the longitudinal axis of the recesses by an angle of inclination such that they never assume a vertical orientation over the pivotal movement range of the shift lever.
In a preferred embodiment the recess pattern comprises series of recesses extending along the ball portion. Between adjacent series of recesses inclined wall portions of the overmoulded ball portion are formed which are disaligned with the vertical slots over the entire pivot movement range of the shift lever.
In a preferred embodiment the recesses are rectangular in cross-section, and in each of the series of recesses the recesses have two opposite side walls aligned in the direction of the extension of the series of recesses. In this manner wall portions of uniform thickness are formed between adjacent series of recesses.
In a preferred embodiment the recesses have a square cross-section rotated by 45° with respect to the longitudinal axis of the shift lever.
Preferably the longitudinal line of extension of each series of recesses is oriented at an angle of 45° with respect to the longitudinal axis of the shift lever.
The present invention will now be described with reference to preferred embodiment shown in the drawings in which:
As shown in
When such a series of vertical sidewalls of recesses 2, 4, 6 and 8 passes side edges 24, 26 of vertical slots 22 during a shift movement a feeling of a slight jerk or unevenness is resulting.
In
As can be seen in
According to the invention the straight side walls of the grid of crossing wall portions are inclined with respect to the longitudinal direction of the shift lever such that they are never aligned with the vertical side edges 14, 16 of the vertical slots 22 of the socket over the pivotal movement range of the shift lever.
Filing Document | Filing Date | Country | Kind |
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PCT/EP2015/065333 | 7/6/2015 | WO | 00 |