Safety lock for automobiles

A safety lock for automobiles with a manual transmission operable by a shift stick is associated with the shift stick which includes a double-armed shift lever supported by a ball joint pivotally disposed in a floor-mounted neck member and a locking sleeve disposed on the shift stick axially movable between upper and lower end positions in which the sleeve may be locked and having a locking member at its bottom end adapted to firmly engage a flanged tubular member mounted on the neck member when locked in its lower position.

BACKGROUND OF THE INVENTION 
The present invention relates to a safety lock for automobiles which have a 
manual transmission operable by a double-armed stick shift lever supported 
by means of a ball joint disposed within a neck portion mounted on the 
floor of the automobile. 
Such a transmission shift lever lock is disclosed, for example, in U.S. 
Pat. No. 2,046,279 wherein the ball joint for the shift lever is arranged 
within an upwardly projecting transmission housing section which also 
receives a locking block. Such a locking arrangement, together with all 
the mounting structure, is an integral part of the whole transmission. It 
is provided by the transmission factory and cannot be retrofitted. Without 
doubt, such transmission locks are very safe, but they are unusable for 
vehicles in which they have not been installed by the factory assembling 
the vehicle and, therefore, they have not found any noticeable 
utilization. 
It is the object of the present invention to provide a safety lock for 
automobiles, in which, like in the arrangement according to U.S. Pat. No. 
2,046,279, the transmission shift lever may safely be locked but which may 
be installed into an automobile, especially a passenger car, after its 
assembly and which may be installed in a relatively simple and economical 
manner. 
SUMMARY OF THE INVENTION 
A safety lock for an automobile with a manual transmission operable by a 
shift stick pivotally mounted by a ball joint which is supported in a neck 
member mounted on the floor of the automobile includes a locking sleeve 
surrounding the shift stick and being movable between an upper operating 
position and a lower end position in which a locking member disposed at 
the lower end of the sleeve is received in an upper tube section 
projecting from a flange having a lower tube section firmly mounted on the 
neck member. Means are provided at the top end of the shift stick for 
locking the sleeve member in the upper operating position or in its lower 
end position in which its engagement with the flanged tube section 
prevents operation of the transmission. 
The device according to the present invention need not be installed by the 
transmission and vehicle manufacturers. No provisions or changes on the 
transmission housing are necessary, which provisions would have to be made 
by the transmission manufacturer; rather, the invention utilizes the 
tubular neck member which receives the shift lever ball joint and which is 
normally provided in this type transmission for the support of the shift 
lever. Only a flanged tube section is mounted over the neck member, which 
flanged tube section is then utilized as a locking block and which is 
adapted to closely receive the locking member provided at the bottom end 
of the axially movable sleeve for blocking movement of the shift lever. In 
the locking position of the sleeve, shifting of the transmission is not 
possible. Shifting is only possible when the axially movable sleeve is in 
its upper end position where it is preferably also lockable for safety 
reasons. 
The arrangement according to the present invention may easily be installed 
into automobiles even after manufacture simply by placing the flanged tube 
section onto the neck member mounted on the vehicle floor and replacing 
the original shift lever by a new lever which carries an axially movable 
sleeve which has at its lower end a lock member and which may be locked to 
the transmission shift lever in its lower end position in which it blocks 
operation of the shift stick.

DESCRIPTION OF A PREFERRED EMBODIMENT 
As shown in the figures, the bottom floor panel 1 of an automobile has a 
neck member 2 mounted thereon and surrounded by a layer 32 of a foamed 
material above which a top floor panel 33 is disposed which forms the top 
surface of the automobile's floor. A double arm shift lever 5 is pivotally 
supported by means of a ball joint 4 mounted within the neck member 2 by 
bearing rings 3. The bearing rings 3 are forced into engagement with the 
ball joint 4 by a spring 34 which is held in position by a spring ring 30 
seated in a groove in the neck member 2. The shift lever 5 has its lower 
end below the automobile's floor linked to a transmission by a shift rod 6 
which is secured to the shift lever 5 by a lock washer 31. The upwardly 
projecting arm of the shift lever 5 carries at its upper end a shift stick 
35. 
For the installation of the safety device according to the invention, the 
shift stick 35 alone is removed from the upper end of the shift lever 5 
and replaced by a new shift stick 35a (FIG. 4) or the shift stick 35 is 
removed together with the double arm shift lever 5 and the ball joint 4 
and replaced by a new structure. 
Experience has shown that, generally, the second method is preferable, 
since the ball joint 4 and the bearing rings 3 are usually worn to such a 
degree that their replacement is justified. 
After removal of the spring ring 30 and the lock washer 31, the complete 
original shift stick 35, together with the double arm shift lever 5, the 
ball joint 4 and the bearing rings 3 may be removed so that, of the whole 
structure, only the neck member 2 remains in place as shown in FIG. 2. 
For the mounting of the safety device according to the invention, a flanged 
tube section 11, 12 is placed onto the neck member 2 and fixed in position 
by shear bolts. It is not difficult to move the flanged tube section 11 in 
position over the neck member 2 since the foamed material 32 does not 
provide any particular resistance. The flanged tube section 11, 12 
consists of lower and upper tubular parts 11, 12 which are joined together 
by an intermediate flange 8. The upper tubular part 12 is inclined 
somewhat with respect to the lower tubular part 11 since the shaft stick 
of a passenger car is usually inclined backwardly. The upper tubular part 
12, which is actually a locking member, includes a key 13 adapted to 
insure that the locking member 10 of a locking sleeve 9, which has a 
corresponding groove, is always inserted in the proper angular position. 
After these preparations, the new shift stick 35 is inserted, its lower arm 
5 is linked to the shift rod 6 and secured in place by the lock washer 31, 
the ball joint 4 together with new bearing rings 3 is placed into the neck 
member 2 and secured in place by the spring ring 30. Then already the 
safety device according to the invention is fully operative since the new 
shift stick 35 is already provided with the axially movable sleeve 9 which 
carries the locking member 10 at its lower end and has a lock 15 provided 
in the shift button for locking the sleeve 9 in both axial end positions 
by means of a lock pin 16 operable by a key 17 which is insertable into 
the lock 15, the locking pin 16 being radially movable into, and out of, 
engagement with the sleeve 9. 
FIG. 4 shows the shift lever in a locked state and so does FIG. 5, left 
side, while the right side shows the shift lever in the operative 
position. As shown in FIG. 4, the locking member 10 is inserted into the 
flanged tube section 12 in which position operation of the shift lever is 
blocked. As shown in the right side of FIG. 5, the locking member 10 is 
disposed in a non-restraining position above the flanged tube section 12 
in which position the shift stick 35 is freely movable. 
The shift stick 35a comprises a tube 7 mounted on the upper arm of the 
shift lever 5 by means of pins or bolts 14, the axially movable sleeve 9 
being disposed around and spaced from the tube 7. A tubular guide member 
18, preferably of plastic material, is fastened to the lower end portion 
of the tube 7 for slidably supporting the lock member 10. A spring 19 is 
disposed in the annular space between the tube 7 and the sleeve 9 and 
abuts at its lower end said guide member 18 and, at its upper end, a ring 
member 20 associated with the locking sleeve 9 so as to resiliently retain 
the sleeve 9 with the locking member 10 out of engagement with the tube 
section 12. The shift button 21 is mounted on the sleeve 9 and is axially 
movable therewith. A lock 15 is disposed within the shift button 21 and is 
adapted to operate the locking pin for engagement with the shift 
lever-mounted tube 7 to hold the locking sleeve 9 down against the force 
of spring 19 for locking the transmission as to lock the sleeve 9 in its 
upper operative position. 
A trained worker needs only a few minutes for the conversion of the gear 
shift mechanism. Accordingly, the installation of the device according to 
the invention involves only minimal expenditure. It is noted, furthermore, 
that the parts required are inexpensive so that the complete installation 
is very economical. 
The safety device according to the present invention therefore permits 
retrofitting thereof into vehicles in a very economical manner.