Apparatus for adjusting the level of the deflector for a shoulder belt in the occupant restraint system of an automotive vehicle

The frame of the motor vehicle carries a vertical rail defining an elongated track for a plastic slide which carries a first pivotable lever serving as a means for releasably coupling the slide to the rail. A pivot member which secures the first lever to the slide carries a deflector for the shoulder belt of the occupant restraint system, and the first lever has a tooth which is biased against one of two sidewalls of the rail to enter into one of a row of sockets in the one sidewall. A second lever or a wheel is provided to extract the tooth from a selected socket and to thus enable the slide to move along the track to a different position in which the tooth is aligned with a different socket. The first lever is centered between the two sidewalls which flank the track for the slide. The central portion of the first lever resembles or constitutes a disc with two convex surfaces which are closely adjacent the respective sidewalls and have centers of curvature on or close the pivot axis of the first lever.

BACKGROUND OF THE INVENTION 
The invention relates to occupant restraint systems for use in automotive 
vehicles, for example, in road vehicles. More particularly, the invention 
relates to improvements in apparatus for selecting the level of a 
deflector for a shoulder belt or strap of an occupant restraint system. 
Published German patent application No. 37 13 137 discloses an apparatus 
wherein a slide is movable up or down in a substantially vertical rail and 
carries a pivotably mounted level which can be moved to a position of 
engagement with or disengagement from the rail. The pivot member for the 
lever carries a deflector for a shoulder belt. A spring is provided to 
permanently bias the lever away from engagement with the rail. One end of 
the shoulder belt is connected to the rotary spool or reel of a standard 
retractor, and the other end of the shoulder belt carries a customary 
tongue which can be inserted into a buckle after the belt has been caused 
to overlie the chest of the occupant of the respective seat in a motor 
vehicle. When the shoulder belt is subjected to a pull, the lever on the 
slide is caused to move downwardly and is pivoted relative to the slide so 
that its tooth enters one of a row of slots in the rail. The rail is 
affixed to the so-called B-column of the frame of the motor vehicle. A 
bowden wire is used to change the level of the slide in the track which is 
defined by the rail, and the adjustment of the level of the slide by way 
of the bowden wire takes place in automatic response to forward or 
rearward adjustment of the respective seat in the motor vehicle. The 
bowden wire can be withdrawn against the resistance of a spring. A force 
which acts upon the shoulder belt to extract a length of the belt from the 
retractor must overcome the bias of the spring which acts upon the bowden 
wire, as well as the resistance of the spring which acts upon the lever, 
in order to ensure that the projection of the lever will enter a slot of 
the rail. The apparatus which is disclosed in the German patent 
application is rather complex and expensive. 
OBJECTS OF THE INVENTION 
An object of the invention is to provide a novel and improved apparatus 
which can be used to adjust the level of a deflector for the shoulder 
strap or belt of an occupant restraint system for use in a motor vehicle. 
Another object of the invention is to provide a simple, compact and 
reliable apparatus which can be used as a superior substitute for existing 
apparatus. 
A further object of the invention is to provide an apparatus which is less 
likely to jam than a conventional level adjusting apparatus. 
An additional object of the invention is to provide an apparatus which can 
be manipulated by hand to select an optimum level for the deflector of a 
shoulder belt so that the person occupying the respective seat or 
intending to occupy the seat is in a position to select an optimum level 
of the deflector for the purposes of convenience and safety. 
Still another object of the invention is to provide the apparatus with a 
novel and improved slide and with a novel and improved device which 
releasably couples the slide to a part of the vehicle frame. 
A further object of the invention is to provide a novel and improved 
apparatus of the above outlined character wherein the means for separably 
coupling the slide, which carries the deflector, to the frame of the motor 
vehicle can establish a highly reliable disengageable connection between 
the slide and the frame of the motor vehicle. 
An additional object of the invention is to provide a novel and improved 
method of manipulating the above outlined coupling device. 
Another object of the invention is to provide a novel and improved method 
of indicating to the operator that the slide is in the process of moving 
the deflector for a shoulder belt with reference to the frame of the motor 
vehicle. 
An additional object of the invention is to provide a novel and improved 
guide for the slide of the above outlined level adjusting apparatus. 
Another object of the invention is to provide one or more safety devices 
which serve as a last resort to establish a reliable connection between 
the deflector and the frame of the motor vehicle in an emergency, 
particularly in the event of a collision and/or overturning of the 
vehicle. 
SUMMARY OF THE INVENTION 
The invention is embodied in an apparatus for changing the level of a 
deflector for a shoulder belt or strap in an occupant restraint system for 
use in a motor vehicle. The improved apparatus comprises a guide (e.g., an 
elongated metallic rail having a substantially C-shaped cross-sectional 
outline) which is connectable to or can be installed in the body of a 
motor vehicle and defines an elongated track which is substantially 
vertical in upright position of the vehicle. The guide has two sidewalls 
which are preferably exactly parallel to each other and flank the track. 
One of the sidewalls has a plurality of preferably (but not necessarily) 
equidistant sockets (e.g., in the form of elongated closed slots extending 
all the way through the one sidewall) which are spaced apart from each 
other in the longitudinal direction of the track, and the apparatus 
further comprises a slide or carriage which is installed in the guide for 
movement along the track. The apparatus also comprises means for separably 
coupling the slide to the guide, and such coupling means comprises a 
(first) lever having at least one arm including a projection (e.g., in the 
form of a tooth or pallet) adjacent the one sidewall to enter or leave a 
selected socket in response to pivoting of the lever about an axis which 
is normal to the track and is disposed substantially midway between the 
sidewalls. Still further, the apparatus comprises deflector-supporting 
pivot means defining the aforementioned axis and secured to the slide. The 
lever may but need not be rotatably mounted on the pivot means and 
preferably includes substantially mirror symmetrical centering portions 
which flank the pivot means; each of these centering portions is 
preferably closely or immediately adjacent a different one of the two 
sidewalls, and the apparatus still further comprises means for yieldably 
biasing the lever for pivotal movement about the axis which is defined by 
the pivot means in a first direction to urge the projection against the 
one sidewall and into a selected socket in response to movement of the 
slide along the track to a position in which the projection is in register 
with the selected socket. The apparatus also comprises means for pivoting 
the lever about the axis in a second direction counter to the first 
direction to thus withdraw the projection from a selected socket 
preparatory to movement of the slide along the track. 
The width of the track (as measured transversely of the axis) is preferably 
constant, and the centering portions of the lever preferably include 
convex surfaces which are adjacent the respective sidewalls. The centers 
of curvature of such convex surfaces are on or close to the axis which is 
defined by the pivot means. The lever can include a substantially 
disc-shaped section, and the centering portions preferably form part of 
such disc-shaped section. 
The pivoting means is movable between an operative and an inoperative 
position, and the biasing means is free to maintain the projection in 
contact with the one sidewall or in a selected socket in the inoperative 
position of the pivoting means. 
In accordance with a presently preferred embodiment, the lever of the 
coupling means has two arms one of which is provided with the projection 
and the other of which is engaged by the pivoting means. The pivoting 
means can comprise a second lever which is pivotably mounted in or on the 
slide and has a first arm engaging the lever of the coupling means and a 
second arm which is accessible to the hand of a person (e.g., the occupant 
of a seat in a motor vehicle) to facilitate pivoting of the second lever 
relative to the slide. The lever of the coupling means can be provided 
with a substantially V-shaped or L-shaped cam groove for the first arm of 
the second lever. The cam groove includes two mutually inclined legs and a 
junction between the legs. The second lever assumes an inoperative 
position (in which the biasing means is free to maintain the projection in 
abutment with the one sidewall or in a selected socket) when the first arm 
of the second lever extends into the junction of the cam groove. Means can 
be provided for releasably holding the second lever in the inoperative 
position, and such holding means can comprise one or more springs which 
react against the slide and bear against the second lever. 
Means can be provided for biasing the slide longitudinally of the track 
toward a predetermined position, and such biasing means can comprise a 
torsion spring. The latter ensures that a person wishing to adjust the 
level of the deflector must exert a force only to move the slide in one 
direction (against the opposition of the just mentioned biasing means). 
The other sidewall can be provided with a plurality of recesses (e.g., in 
the form of elongated closed slots) which are spaced apart from each other 
in the longitudinal direction of the track. The mutual spacing of the 
recesses can match or closely approximate the mutual spacing of the 
sockets, and the slide can be provided with at least one resilient 
follower having a portion which extends into one of the recesses when the 
projection of the lever of the coupling means extends into one of the 
sockets. 
The slide can contain or consist of plastic material and preferably 
includes a plurality of sections which are connected to each other. The 
sections can constitute plastic extrusions or moldings and can include 
elongated shell-shaped first and second sections which extend 
longitudinally of the track. The lever of the coupling means is then 
disposed between the first and second sections of the slide. 
Instead of having a substantially V-shaped or L-shaped cam groove, the 
lever of the coupling means can be provided with a substantially 
triangular cam groove, and the pivoting means can again comprise a second 
lever having a first arm which extends into the triangular cam groove and 
a second arm which is accessible for manipulation by a person, i.e., for 
pivoting of the second lever between operative and inoperative positions. 
When the second lever assumes its inoperative position (in which the means 
for biasing the lever of the coupling means is free to maintain the 
projection in abutment with the one sidewall or in a selected socket), the 
first arm of the second lever extends into a predetermined corner of the 
triangular cam groove. The means for releasably holding the second lever 
in the inoperative position (in which the first arm of the second lever 
extends into the predetermined corner of the triangular cam groove) can 
include at least one spring which reacts against the slide and bears 
against the second lever. 
As mentioned above, the projection can resemble a tooth, and such tooth can 
be provided with a first flank having a first inclination relative to the 
longitudinal direction of the track, and a second flank having a less 
pronounced second inclination with reference to the longitudinal direction 
of the track. Such inclination of the tooth flanks facilitates penetration 
of the tooth into and its retention in a selected socket of the one 
sidewall. 
The inner side of the one sidewall (i.e., the side which is adjacent the 
track) can be provided with ramps which are adjacent the sockets to direct 
the projection into the respective sockets when the biasing means for the 
lever of the coupling means is free to urge the projection against the one 
sidewall and the slide is caused to move longitudinally of the track in a 
predetermined direction. The sockets in the one sidewall have first and 
second end portions which are spaced apart from each other in the 
longitudinal direction of the track, and the one sidewall has surfaces 
which bound the first end portions of the sockets and preferably extend 
into the track to intercept the oncoming projection while the slide is 
caused to move in the predetermined direction. The ramps are adjacent the 
second ends of the respective sockets. 
The lever of the coupling means can be provided with a second projection 
which extends into one of the recesses in the other sidewall of the guide 
when the first named projection extends into one of the sockets in the one 
sidewall. The two projections of the lever of the coupling means can be 
disposed substantially diametrically opposite each other with reference to 
the axis which is defined by the pivot means. If the lever of the coupling 
means has two arms, one of the projections is provided on the first arm 
and the other projection is provided on the second arm of such lever. 
The lever of the coupling means can be provided with a first pocket (e.g., 
a window in the arm which carries the first named projection), and the 
slide can be provided with at least one second pocket adjacent the first 
pocket. The means for biasing the lever of the coupling means can comprise 
a spring (e.g., a coil spring) which is received in the pockets to react 
against the slide and to bear against the lever of the coupling means. 
The sockets in the one sidewall of the guide preferably form a row 
including a first socket and a last socket (as seen in a predetermined 
direction longitudinally of the track). The guide of such apparatus can be 
provided with a stop which extends into the path of movement of the lever 
of the coupling means along the track in the predetermined direction to 
pivot the lever in the first direction and to thereby introduce the first 
named projection into the last socket of the row. The at least one arm of 
the lever of the coupling means (i.e., the arm which carries the first 
named projection) has a first side facing the one sidewall and a second 
side facing the other sidewall. The first named projection is provided at 
the first side of such arm, and the stop of the guide serves to engage the 
second side of the at least one arm. 
The slide which pivotally supports the lever of the coupling means can be 
provided with two resilient followers one of which tracks the one sidewall 
and the other of which tracks the other sidewall of the guide. The one 
follower has a portion which rides over the sockets in response to 
movement of the slide longitudinally of the track, and the other follower 
has a portion which rides over the recesses in the other sidewall in 
response to movement of the slide longitudinally of the track. The mutual 
spacing of the recesses can match or approximate the mutual spacing of the 
sockets so that the aforementioned portion of the one follower rides over 
a socket when the aforementioned portion of the other follower rides over 
a recess and vice versa. To this end, each socket can be aligned with one 
of the recesses, as seen transversely of the track, and the two followers 
of the slide can be mirror symmetrical to each other with reference to a 
plane which extends longitudinally of the track and includes the axis for 
the lever of the coupling means. The aforementioned portions of the two 
followers can be arranged to generate noise in response to riding over the 
sockets and the recesses, respectively. 
The slide can include a sleeve which extends from the track and surrounds a 
portion of the pivot means for the lever of the coupling means. The 
deflector for the shoulder belt surrounds such sleeve of the slide. The 
sleeve can be provided on one of the aforementioned first and second 
sections of the slide. 
The pivot means can be non-rotatably connected with the lever of the 
coupling means, and the means for pivoting this lever can include means 
for turning the pivot means about the axis. The turning means can comprise 
a handle (e.g., a substantially wheel-shaped handle or a handle having a 
polygonal outline). The turning means is movable about the axis to and 
from an inoperative position in which the means for biasing the lever of 
the coupling means is free to urge such lever against the one sidewall, 
and the apparatus can further comprise an additional lever which is 
pivotably mounted on the lever of the coupling means, and means (e.g., a 
link train) for transmitting motion from the turning means to the 
additional lever in order to pivot the additional lever toward the one 
sidewall in response to movement of the turning means to the inoperative 
position and to pivot the additional lever away from the one sidewall in 
response to movement of the turning means from the inoperative position. 
It is also possible to employ an additional lever which is pivotably 
mounted on the lever of the coupling means and is operative to engage the 
one sidewall and enter one of the sockets in response to abrupt movement 
of the slide along the track in a predetermined direction (e.g., in the 
event of a collision or another accident). The lever of the coupling means 
has a first side which confronts the one sidewall and a second side which 
confronts the other sidewall. In accordance with a presently preferred 
embodiment of the apparatus, the first named projection and the additional 
lever are disposed at the first side of the lever of the coupling means. 
The novel features which are considered as characteristic of the invention 
are set forth in particular in the appended claims. The improved apparatus 
itself, however, both as to its construction and its mode of operation, 
together with additional features and advantages thereof, will be best 
understood upon perusal of the following detailed description of certain 
presently preferred specific embodiments with reference to the 
accompanying drawing.

DESCRIPTION OF PREFERRED EMBODIMENTS 
FIGS. 1 to 3 show certain details of an apparatus which embodies one form 
of the present invention. The purpose of the apparatus is to adjust the 
level of a substantially annular deflector D for a shoulder belt or strap 
B (see FIG. 8) so that the belt B will be more comfortable to and will 
better protect the occupant of the respective seat S in a motor vehicle. 
The apparatus comprises a vertical or nearly vertical guide 1 which is 
secured to or is installed in the so-called B-column or frame member BC 
(FIG. 8) of the frame of the motor vehicle. The illustrated guide 1 is an 
elongated metallic rail having a substantially C-shaped cross-sectional 
outline (see particularly FIG. 3) and defining an elongated track la 
flanked by two elongated parallel sidewalls 18 and 19. The track 1a of the 
guide 1 receives an elongated slide 2 which is made of or contains a 
suitable plastic material and includes two elongated substantially 
shell-shaped sections 9, 10 connected to each other and confining a 
pivotable lever 3 forming part of a means for separably coupling the slide 
2 to the guide 1 in a selected position as seen longitudinally of the 
track 1a. The lever 3 is a two-armed lever and is pivotable about an axis 
extending at right angles to the longitudinal direction of the track 1a 
substantially or exactly midway between the sidewalls 18 and 19. The pivot 
means for the lever 3 comprises a pivot member 4 having a polygonal (e.g., 
hexagonal) head 5 which is spaced apart from the track 1a between the 
sidewalls 18, 19 of the guide 1. 
The head 5 is outwardly adjacent a smooth cylindrical portion 6 terminating 
in an annular shoulder which abuts the adjacent surface of the lever 3. An 
externally threaded inner end portion 7 of the pivot member 4 is received 
in a tapped bore of the substantially disc-shaped central portion of the 
lever 3. The smooth cylindrical portion 6 is surrounded by the deflector D 
(not shown in FIGS. 1 to 3) for the shoulder belt B. The deflector D can 
swivel (i.e., perform a pendulum movement) about the axis of the pivot 
member 4 so that the inclination of its eyelet can change in dependency 
upon the orientation of that portion of the shoulder belt B which is being 
deflected by the part D. As a rule, the deflector D has a substantially 
triangular outline with the hole for the portion 6 in one of the corners 
and a slot for the shoulder belt B extending between the other two 
corners. The slot is bounded by suitably rounded surfaces of the deflector 
D to facilitate sliding movements of the shoulder belt B as well as to 
reduce the likelihood of damage to the belt. One end of the belt B is or 
can be connected to the spool or reel of a suitable retractor R shown in 
FIG. 8 (e.g., a retractor of the type disclosed in U.S. Pat. No. 4,241,886 
granted Dec. 30, 1980 to Maekawa et al.), and the other end portion of the 
belt B can carry a tongue which is removably insertable into a buckle. The 
tongue can be of the type disclosed in commonly owned copending patent 
application Ser. No. 423,114 filed Oct. 19, 1989 by Knut Oberhardt. The 
retractor R can be installed in the column BC or elsewhere close to or at 
the floor level of the frame of the motor vehicle, and the buckle is 
affixed to the floor at the inner side of the respective seat S. The 
occupant restraint system which embodies the apparatus of the present 
invention can further include the structure which is disclosed in commonly 
owned copending paten application Ser. No. 451,091 filed Dec. 15, 1989 by 
Walter Notar for "Apparatus for damping translatory and rotary movements" 
and in commonly owned copending patent application Ser. No. 242,910 filed 
August, 1988 for "Belt clamping apparatus for a seat belt system 
comprising a belt retractor". 
As can be seen in FIG. 2, the means for preferably separably connecting the 
sections 9 and 10 of the slide 2 to each other comprises complementary 
male and female detent elements. Each of the sections 9, 10 can constitute 
an extrusion or a molding, depending on the nature of the machine which is 
used to mass-produce such parts. The sections 9, 10 define a chamber which 
receives the lever 3 of the coupling means with certain freedom of pivotal 
movement relative to the slide 2 and guide 1. The section 9 has an opening 
11 which receives a ring-shaped axial extension 12 of the disc-shaped 
central portion of the lever 3. The extension 12 defines a portion of the 
tapped bore for the inner end portion 7 of the pivot member 4. The section 
9 also comprises a ring-shaped extension or bead 13 which surrounds the 
opening 11 and serves as an abutment for the adjacent surface of the lever 
3. The section 10 has an inwardly extending collar 14 which surrounds the 
inner part of the cylindrical portion 6 of the pivot member 4. The inner 
end face of the collar 14 is adjacent the respective surface of the 
disc-shaped central portion of the lever 3. 
The disc-shaped central portion of the lever 3 includes two preferably 
mirror symmetrical centering portions 15, 16 having convex surfaces 15a, 
16a which are closely adjacent or even contact the inner sides 18a, 19a of 
the sidewalls 18, 19, respectively. The centers of curvature of the convex 
surfaces 15a, 16a are located on or very close to the axis of the pivot 
member 4, i.e., in a plane extending longitudinally of the track 1a and 
including the axis of the member 4. The diameter of the cylindrical 
surface which includes the convex surfaces 15a, 16a is only slightly 
smaller than the shortest distance between the inner sides 18a, 19a of the 
sidewalls 18, 19 (i.e., those sides which are adjacent the track 1a). 
The sidewall 19 of the track 1 is provided with a row of preferably (but 
not necessarily) equidistant elongated slots 20 (hereinafter called 
sockets) each of which can receive a tooth- or pallet-shaped projection 21 
at the free end of a first arm 22 of the two-armed lever 3. The means for 
biasing the lever 3 in a clockwise direction (as viewed in FIG. 1) 
comprises a coil spring 23 reacting against the slide 2 and bearing 
against that side 22b of the arm 22 which faces away from the side 22a 
carrying the projection 21. The coil spring 23 is received in a pocket 25 
of the section 9 and is free to bias the projection 21 against the inner 
side 19a and into the adjacent socket 20 as soon as the slide 2 is moved 
along the track 1a to assume a position in which the projection 21 is in 
register with the selected socket 20. 
The apparatus further comprises means for pivoting the lever 3 against the 
opposition of the coil spring 23. Such pivoting means comprises a second 
lever 29 which is pivotably mounted on a shaft 30 in the section 10 of the 
slide 2 and has a first arm 28 extending into a substantially V-shaped cam 
groove 27 in the second arm 26 of the lever 3. The shaft 30 extends 
transversely of the track 1a so that the lever 29 is pivotable in the 
plane which includes the axis of the pivot member 4, and the second or 
outer arm 31 of the lever 29 extends away from the guide 1 to be readily 
grasped by the hand of a person who wishes to adjust the level of the 
deflector D. The free end of the second arm 31 of the lever 29 carries a 
round knob 32. The free end 33 of the first arm 28 of the lever 29 is 
received in the junction between the two mutually inclined branches or 
legs of the V-shaped cam groove 27 when the lever 29 assumes an 
inoperative position in which the coil spring 23 is free to maintain the 
projection 21 in contact with the inner side 19a of the sidewall 19 or in 
a selected socket 20. In order to expel the projection 21 from the 
selected socket 20 (preparatory to movement of the slide 2 along the track 
1a in order to move the projection 21 to a position of register with 
another socket 20), the operator moves the knob 32 of the second arm 31 of 
the lever 29 to the right or to the left (as seen in FIG. 2) so that the 
free end 33 of the arm 28 leaves the junction and enters the one or the 
other branch or leg of the V-shaped cam groove 27 in the arm 26 of the 
lever 3. This results in a pivotal movement of the lever 3 in a 
counterclockwise direction (as seen in FIG. 1), i.e., the cam groove 27 is 
moved from the solid-line position to the phantom-line position of FIG. 1 
and the projection 21 is then located in the track 1a so that the knob 32 
can be used as a means for moving the slide 2 and the lever 3 
longitudinally of the track 1a until the projection 21 moves to a position 
of register with a newly selected socket 20. The knob 32 is then released 
and the spring 23 is free to propel the projection 21 into the newly 
selected socket 20. The two legs of the illustrated V-shaped groove 27 
make an obtuse angle. The slide 2 and the lever 3 are moved up or down, 
depending on the stature and/or posture of the occupant of the seat S and 
on the width of the shoulder which is to be engaged by the shoulder belt 
B. 
The means for holding the lever 29 in the inoperative position comprises 
two leaf springs 35, 36 which are affixed to and react against the section 
10 of the slide 2 in order to bear against the second arm 31 of the lever 
29. These leaf springs cooperate to bias the lever 29 to that position 
(shown in FIG. 2 by solid lines) in which the free end 33 of the first arm 
28 extends into the junction between the legs of the V-shaped cam groove 
27 in the second arm 26 of the lever 3. The leaf springs 35, 36 then 
cooperate with the coil spring 23 to maintain the projection 21 in the 
selected socket 20. This is desirable and advantageous because the three 
springs 23, 35, 36 jointly prevent undesirable expulsion of the projection 
21 from the selected socket 20, e.g., in response to abrupt acceleration 
of the apparatus in the event of an accident. 
The sidewall 18 of the guide 1 is provided with a row of preferably (but 
not necessarily) equidistant elongated slots 40 (hereinafter called 
recesses) the mutual spacing of which is or can be the same or nearly the 
same as that of the row of resilient follower 42 having an arcuate portion 
41 which rides over the recesses 40 when the slide 2 is caused to move 
longitudinally of the track 1a and the portion 41 snaps into one of the 
recesses 40 when the projection 21 is caused to enter a socket 20. The 
arcuate portion 41 of the follower 42 can produce clicking noises while 
riding over the recesses 40; this indicates to the operator of the lever 
29 that the slide 2 is in motion as well as that the projection 21 is 
aligned with one of the sockets 20. The follower 42 can but need not form 
an integral part of the section 9 of the slide 2, depending on the 
elasticity of the material of the section 9 and on the desired elasticity 
of this follower. 
The apparatus still further comprises means for biasing the slide 2 in one 
direction longitudinally of the track 1a. The illustrated biasing means 
comprises a torsion spring 45 which tends to wind itself onto a core on 
the guide 1 and the free end of which is affixed to the slide 2 to pull 
the latter in a direction to the left, as seen in FIG. 1 or 2. The torsion 
spring 45 can include a relatively wide strip (see FIGS. 4, 6 and 7) of 
spring steel or the like. 
It will be seen that, in contrast to the construction of the apparatus 
which is disclosed in the aforediscussed published German patent 
application No. 37 13 137, the coil spring 23 serves to permanently bias 
the arm 22 of the lever 3 in a direction to maintain the projection 21 in 
abutment with the inner side 19a of the sidewall 19 or in the adjacent 
socket 20. Moreover, the lever 3 is much less likely to jam than in a 
conventional apparatus because the convex surfaces 15a, 16a of its 
centering portions 15, 16 are immediately or closely adjacent the inner 
sides 18a, 19a of the respective sidewalls 18, 19, i.e., the diameter of a 
cylindrical surface including the convex portions 15a, 16a is only 
slightly smaller than the shortest distance between the sidewalls 18 and 
19. Such proper centering of the lever 3 between the sidewalls 18, 19 
relieves the slide 2 which can be made of a lightweight plastic material 
because it need not withstand pronounced deforming and/or other stresses. 
The number of sockets 20 can be selected practically at will so as to 
enable the operator of the pivoting means (lever 29) to select any one of 
two, three, four, five or more different levels for the deflector D. When 
the lever 3 couples the slide 2 to the guide 1, its projection 21 extends 
into one of the sockets 20 and is urged to remain in such socket by the 
coil spring 23 as well as by the leaf springs 35, 36, and the convex 
surfaces 15a, 16a of the centering portions 15, 16 of the lever 3 are 
immediately adjacent or actually abut the inner sides 18a, 19a of the 
respective sidewalls 18, 19 to thus ensure that the lever 3 is maintained 
in an optimum position with reference to the guide 1 and to thus fully or 
at least substantially relieve the slide 2. The springs 23, 35 and 36 
cooperate to ensure that a pull upon the shoulder belt B cannot cause the 
deflector D to disengage the projection 21 of the lever 3 from the 
sidewall 19 of the guide 1 when such disengagement is undesirable or 
dangerous to the occupant of the seat S adjacent the guide 1. The 
lightweight slide 2 merely serves as a means for ensuring that the lever 3 
can be moved along the track 1a to a selected position in which the 
projection 21 is adjacent a desired socket 20 and can enter such socket as 
soon as the springs 23, 35 and 36 are capable of pivoting the lever 3 in a 
clockwise direction (as seen in FIG. 1). The slide 2 need not take up 
and/or withstand any stresses which develop as a result of tensioning of 
the shoulder belt B when the lever 3 maintains its projection 21 in a 
selected socket 20. However, it is clear that, if desired, the slide 2 can 
be made of a suitable metallic material without departing from the spirit 
of the invention. 
The centering portions 15, 16 of the disc-shaped central portion of the 
lever 3 ensure that the axis of the pivot member 4 is maintained in an 
optimum position with reference to the sidewalls 18, 19 of the guide 1, 
preferably in a plane which extends longitudinally of the tracks 1a 
substantially or exactly midway between the inner sides 18a, 19a of the 
sidewalls 18 and 19. Such accurate positioning of the pivot axis for the 
lever 3 contributes to the ease of penetration of the projection 21 into a 
selected socket 20 when the lever 3 is permitted to pivot under the action 
of the spring 23 and the springs 35, 36 are free to maintain the lever 29 
of the pivoting means in the inoperative position. 
The bias of the spring 23 can be readily selected in such a way that this 
spring reliably ensures retention of the projection 21 in a selected 
socket 20 in the event of an accident. The leaf springs 35, 36 assist the 
coil spring 23 when the lever 29 is free to assume its inoperative 
position in order to further reduce the likelihood of unintentional 
disengagement of the lever 3 from the guide 1, for example, in the event 
of an accident when the improved apparatus is or can be accelerated in a 
direction which could result in expulsion of the projection 21 from the 
adjacent socket 20 if the lever 3 were biased by the coil spring 23 alone. 
The bias of the leaf springs 35, 36 in a direction to maintain the 
projection 21 of the lever 3 in a selected socket 20 need not be very 
pronounced because any abrupt acceleration of the lever 3, in whatever 
direction, is not likely to generate large forces which would tend to 
expel the projection 21 from the adjacent socket 20. 
If the lever 3 comprises a single arm (e.g., the arm 22), the single arm is 
provided with the projection 21 as well as with the cam groove 27 or with 
an equivalent of this cam groove to receive the free end 33 of the first 
arm 28 of the pivoting lever 29. It is presently preferred to employ a 
two-armed coupling lever 3 with a substantially disc-shaped portion 
(including the centering portions 15 and 16) between its arms 22 and 26. 
An advantage of the V-shaped cam groove 27 is that it ensures disengagement 
of the projection 21 from the sidewall 19 of the guide 1 in response to 
pivoting of the arm 31 and knob 32 of the lever 29 in a direction to the 
right or to the left (as seen in FIGS. 1 and 2), depending on the desired 
direction of advancement of the slide 2 along the track 1a. If the 
illustrated V-shaped cam groove 27 is replaced with a simpler cam groove 
(e.g., with a cam groove including only one branch or leg of the V-shaped 
groove 27), the lever 29 is pivotable (from its inoperative position) in a 
single direction in order to disengage the projection 21 from the sidewall 
19. 
The leaf springs 35, 36 can be replaced by or used jointly with simple 
detent means or any other suitable means for releasably holding the lever 
29 in the inoperative position. 
The torsion spring 45 constitutes a desirable but optional feature of the 
improved apparatus. As stated above, the purpose of this spring is to 
permanently bias the slide 2 in one direction longitudinally of the track 
1a, i.e., the person in charge need not apply any force to move the slide 
in one direction except to oppose excessive acceleration of the slide 2 
under the action of the spring 45. The arrangement may be such that the 
torsion spring 45 biases the slide 2 toward an upper end position so that 
the deflector D can be moved to a lower level when the lever 29 is 
actuated to disengage the projection 21 from the sidewall 19 and to 
thereupon move the slide 2 downwardly by simultaneously stressing the 
spring 45. 
The resilient follower 42 also constitutes an optional but desirable and 
advantageous feature of the improved apparatus. This follower produces 
noise when its arcuate portion 41 enters a recess 40 so that the operator 
of the lever 29 knows that the projection 21 is in accurate register with 
a socket 20. Thus, the operator need not repeatedly move the slide 2 up 
and down in order to accidentally advance the slide 2 to a level at which 
the projection 21 is aligned with one of the sockets 20. The hand holding 
the lever 29 can sense that the arcuate portion 41 of the follower 42 has 
partially entered one of the recesses 40 so that the follower need not 
generate appreciable noise whenever its portion 41 reaches a recess in the 
sidewall 18. 
The guide 1 can be replaced with a guide or rail having a substantially 
U-shaped cross-sectional outline. The illustrated C-shaped cross-sectional 
outline is preferred at this time because the slide 2 and the lever 3 are 
reliably confined in the track 1a which is in communication with the 
surrounding atmosphere only by way of a relatively narrow elongated slot 
(FIG. 3) between the adjacent portions of the sidewalls 18, 19. Such slot 
is necessary in order to provide room for the central portion of the 
section 10 of the slide 2. 
FIGS. 4 and 5 show a portion of a second apparatus. All such parts of this 
second apparatus which are identical with or clearly analogous to the 
corresponding parts of the apparatus of FIGS. 1 to 3 are denoted by 
similar reference characters. 
The somewhat modified projection 21 of the lever 3 which is shown in FIGS. 
4 and 5 is a tooth having a first flank 56 which exhibits a pronounced 
inclination with reference to the longitudinal direction of the track 1a, 
and a second flank 58 with a much less pronounced inclination. The 
left-hand ends of the sockets 20 in the sidewall 19 of the guide or rail 1 
are bounded by surfaces 60 which extend in part into the track 1a to 
intercept the flank 56 of the oncoming tooth-shaped projection 21 while 
the slide 2 is caused to advance in the direction of arrow a. The 
right-hand ends of the sockets 20 are adjacent to ramps 62 which form part 
of the inner side 19a of the sidewall 19 and serve to steer the projection 
21 into the respective sockets 20 while the slide 2 is caused to move in 
the direction of arrow a. The just described configuration and inclination 
of the tooth flanks 56, 58, of the surfaces 60 and of the ramps 62 
facilitates penetration of the projection 21 into a selected socket 20. 
The surfaces 60 and the ramps 62 can be formed in a metallic blank which 
is thereupon converted into the guide 1 of FIGS. 4 and 5. 
The means for biasing the arm 22 of the lever 3 in a clockwise direction 
(as seen in FIG. 4) comprises a coil spring 66 which is received in part 
in a window-like pocket 68 of the arm 22 and in part in two pockets 74 
which are defined by the adjacent arcuate portions 70, 72 of sections 10, 
9 of the slide 2. One end convolution of the coil spring 66 reacts against 
the sections 9, 10 of the slide 2 to urge the other end convolution 
against the arm 22 which thereby tends to maintain the projection 21 in 
contact with the inner side 19a of the sidewall 19 or in a selected socket 
20, depending on the momentary position of the slide 2 relative to the 
guide 1. 
The lever 3 of FIGS. 4 and 5 comprises a second projection 64 which is 
provided on the arm 26 substantially or exactly diametrically opposite the 
projection 21 and extends into one of the recesses 40 when the projection 
21 extends into one of the sockets 20. The configuration of the second 
projection 64 may but need not be identical with that of the projection 
21. 
The guide 1 of FIGS. 4 and 5 further comprises a stop 75 which can 
constitute an inwardly extending bent or otherwise deformed portion of the 
sidewall 18 and is located slightly to the left of the leftmost or last 
socket 20 of the row of such sockets in the sidewall 19. The purpose of 
the stop 75 is to extend into the path of movement of that side (22b) of 
the arm 22 of the lever 3 which faces away from the side 22a (the 
projection 21 is located at the side 22a) and to pivot the lever 3 
clockwise (as seen in FIG. 4) so that the projection 21 is compelled to 
enter the last (leftmost) socket 20 if it has failed to enter this socket 
under the action of the spring 66. The stop 75 further serves as a means 
for preventing total expulsion of the slide 2 from the track 1a in the 
direction of arrow a, i.e., against the opposition of the torsion spring 
45). 
The means for pivoting the lever 3 of FIGS. 4 and 5 against the opposition 
of the coil spring 66 again comprises a lever 29 which is pivotably 
mounted in the section 10 of the slide 2. The free end 33 of the first arm 
28 of the lever 29 extends into a triangular cam groove 50 in the arm 26 
of the lever 3. When the lever 29 is maintained in the inoperative 
position of FIG. 5, the free end 33 of the arm 28 extends into one corner 
of the triangular cam groove 50; at such time, the spring 66 is free to 
maintain the projection 21 in contact with the inner side 19a of the 
sidewall 19 or in a selected socket 20. The means for holding the lever 29 
in the inoperative position comprises two leaf springs 52, 54 which react 
against the slide 2 and bear against the second arm 31 of this lever. The 
leaf springs 52, 54 cooperate with the coil spring 66 to prevent 
unintentional expulsion of the projections 21 form a selected socket 20. 
The section 10 of the slide 20 is provided with a sleeve 80 which surrounds 
the smooth cylindrical portion 6 of the pivot member 4. The deflector D 
(not shown in FIGS. 4 and 5) is mounted for swiveling or pendulum movement 
about the sleeve 80. This sleeve can form an integral part of the section 
10. 
The means for collecting the convolutions of the torsion spring 45 is 
mounted on the guide 1, and the free or outer end portion of this torsion 
spring is connected to the slide 2 to urge the slide counter to the 
direction which is indicated by the arrow a. 
The section 9 of the slide 2 which is shown in FIGS. 4 and 5 comprises two 
resilient followers 78 and 42 which are mirror symmetrical to each other 
with reference to a plane including the axis of the pivot member 4 and 
extending longitudinally of the track 1a. The follower 78 has an arcuate 
portion which is slidable along the inner side 19a of the sidewall 19, and 
the follower 42 has an arcuate portion which is slidable along the inner 
side 18a of the sidewall 18. Each socket 20 is located opposite a recess 
40 (as seen transversely of the track 1a), and the aforementioned arcuate 
portions of the followers 78 and 42 are caused to ride over successive 
sockets 20 and recesses 40, respectively, when the slide 2 is caused to 
advance along the track 1a, either under the bias of the torsion spring 45 
or in the opposite direction. The followers 78, 42 are preferably designed 
to generate a certain noise (clicking) as their arcuate portions ride over 
the sockets and recesses. 
FIG. 4 shows the lever 3 in its operative position by solid lines, i.e., in 
that position in which the projection 21 extends into one of the sockets 
20 and the projection 64 extends into one of the recesses 40. The 
disengaged position of the lever 3 is shown by phantom lines; the slide 2 
is then free to move longitudinally of the track 1a. 
The arm 26 of the lever 3 carries an additional lever or pawl 82 which is 
located substantially opposite the projection 64, i.e., at the same side 
of the lever 3 as the projection 21) and is designed to pivot from the 
solid-line position to the broken-line position of FIG. 4 (and to thereby 
enter one of the sockets 20) in response to abrupt acceleration of the 
slide 2 and lever 3 in the direction of arrow a. The lever 3 is preferably 
provided with a depression or cutout into which the additional lever 82 
normally extends. The pivotal connection between the levers 3 and 82 is 
such that the lever 82 will automatically find its way out of the 
aforementioned depression or cutout if the acceleration of the lever 3 in 
the direction of arrow a is sufficiently pronounced. In the event of an 
accident, the additional lever 82 moves to the broken-line position of 
FIG. 4 and engages the nearest surface 60 in response to movement of the 
slide 2 in the direction of arrow a. The lever 82 then causes the lever 3 
to pivot in a clockwise direction and to introduce its projections 21, 64 
into the adjacent socket 20 and recess 40, respectively. In other words, 
the additional lever 82 pivots clockwise (as seen in FIG. 4) due to its 
inertia in order to engage a surface 60, and the lever 82 then pivots the 
lever 3 to ensure reliable engagement between the lever 3 and the guide 1. 
An advantage of the coupling lever 3 which is shown in FIGS. 4 and 5 is 
that its substantially triangular cam groove or slot 50 can be machined 
and/or otherwise formed at a cost substantially less than the cost of 
making the V-shaped groove 27 in the lever 3 of FIGS. 1 to 3. The reason 
is that the end portion 33 of the first arm 28 of the lever 29 need not be 
guided (in the triangular cam groove 50) with the same degree of accuracy 
as in the cam groove 50. Another advantage of the pivoting means of FIGS. 
4 and 5 is that, if the slide 2 happens to assume a position in which the 
tooth-shaped projection 21 is not received in one of the sockets 20 but 
merely bears against the inner side 19a of the sidewall 19, the arm 28 of 
the lever 29 is disengaged from the surface surrounding the triangular cam 
groove 50 and the springs 52, 54 cannot stress the lever 3. If the vehicle 
is involved in an accident at the time the slide 2 is held in the just 
outlined position (in which the lever 3 is not in positive form-locking 
engagement with the guide 1), the lever 29 can remain in its momentary 
position because the spring 66 is free to pivot the lever 3 as soon as the 
projection 21 moves to a position of register with one of the sockets 20. 
This results in a desirable shortening of the interval which is required 
to positively couple the slide 2 to the guide 1 by way of the lever 3. 
The flanks 56, 58 of the tooth-shaped projection 21 of the apparatus which 
is shown in FIGS. 4-5, and the surfaces 60 and ramps 62 of the sidewall 19 
contribute to more rapid penetration of the projection 21 into a selected 
slot under the bias of the spring 66, and in more reliable retention of 
the projection 21 in the selected socket 20. Moreover, the surfaces 60 
which extend into the track 1a reliably ensure that the projection 21 
penetrates into the adjacent socket 20 even if the slide 2 happens to 
advance along the track 1a (in the direction of arrow a) at a speed which 
is too high to enable the spring 66 to invariably ensure entry of the 
rapidly advancing projection 21 into the nearest socket 20. The arrow a 
indicates the direction in which the slide 2 is likely or bound to be 
accelerated in the event of an accident if, at the time the accident 
occurs, the projection 21 is not already received in one of the sockets 
20. 
An advantage of the second projection 64 is that the slide 2 is reliably 
held (by the projection 21) against movement in the direction of arrow a 
and (by the projection 64) against movement counter to such direction (as 
long as the projections 21 and 64 extend into the adjacent socket 20 and 
the adjacent recess 40, respectively). This is desirable and advantageous 
because it further reduces the likelihood of undesirable shifting of the 
slide 2 along the track 1a, even in the event that the vehicle is 
overturned and comes to a standstill while resting on its roof. 
An advantage of the pocket 68 and of the pockets 74 which are defined by 
the portions 70, 72 of the respective sections 10 and 9 is that the coil 
spring 66 can be assembled with the lever 3, or with the lever 3 and slide 
2, prior to insertion of the slide into the track 1a of the guide 1. 
The stop 75 of the guide 1 also constitutes an optional but desirable 
feature of the apparatus which is shown in FIGS. 4 and 5. This stop not 
only prevents escape of the slide 2 from the track 1a of the guide 1 but 
also ensures that the projection 21 of the lever 3 is compelled to 
penetrate into the last (leaftmost) socket 20 in the sidewall 19. 
The two mirror symmetrical resilient followers 78 and 42 of the slide 2 
which is shown in FIGS. 4 and 5 contribute to the centering action of the 
disc-shaped central portion of the lever 3. FIG. 4 shows that the central 
portion of the lever 3 is not immediately adjacent the inner side of the 
sidewall 19 because this central portion should be capable of bypassing 
the innermost portions of surfaces 60 which extend into the adjacent 
marginal portion of the track 1a. The followers 78 and 42 compensate for 
such inability of the lever 3 to very closely follow the inner side 19a of 
the sidewall 19. The two followers 89, 42 even more reliably inform the 
operator of the lever 29 that the projection 21 has moved to a position of 
accurate alignment with one of the sockets 20 because the penetration of 
their arcuate portions into the adjacent sockets 20 and recesses 40, 
respectively, can be sensed by the hand holding the knob 32. In addition, 
the followers 78, 42 can generate a certain clicking noise which is also 
detectable by the person manipulating the lever 29. 
An advantage of the sleeve 80 on the section 10 of the slide 2 is that the 
deflector D need not come in actual contact with the pivot member 4. 
Therefore, swiveling of the deflector D relative to the sleeve 80 does not 
result in transmission of undesirable torque to the pivot member 4 and to 
the lever 3 (the latter is non-rotatably secured to the pivot member). The 
sleeve 80 renders it possible to assemble the section 10 of the slide 2 
with the deflector D prior to insertion of the lever 3 between the 
sections 9 and 10. The pivot member 4 can be threadedly connected with the 
lever 3 while the deflector D is already mounted on the sleeve 80. Still 
another advantage of the sleeve 80 is that it serves as a means for 
reliably guiding the externally threaded portion 7 of the pivot member 4 
into proper engagement with the internal threads of the lever 3, i.e., the 
sleeve 80 reduces the likelihood of damage to the threads of the pivot 
member 4 and lever 3 during attachment of the pivot member to the 
internally threaded central portion of the lever. 
FIGS. 6 and 7 show portions of a third apparatus which constitutes a 
modification of the apparatus of FIGS. 4 and 5. All such parts of the 
apparatus of FIGS. 6-7 which are identical with or clearly analogous to 
the corresponding parts of the apparatus of FIGS. 4-5 are denoted by 
similar reference characters. The pivoting means including the second 
lever 29 of FIGS. 4-5 is replaced with a pivoting means 180 including a 
wheel or knob which serves as a means for turning the lever 3 between its 
operative and inoperative positions. To this end, the wheel or knob 180 
(hereinafter called wheel) is non-rotatably connected with the pivot 
member 4 for the lever 3 and is readily accessible to be engaged by one 
hand of the person wishing to move the slide 2 longitudinally of the track 
1a between the sidewalls 18, 19 of the guide 1. The wheel 180 can 
constitute a separately produced part which is held (by friction and/or 
otherwise) on the polygonal head 5 of the pivot member 4. The coil spring 
66 (which is mounted in the same way as described with reference to FIGS. 
4 and 5) is free to pivot the lever 3 of FIGS. 6-7 clockwise as soon as 
the wheel 180 has completed an angular movement which is necessary to 
retract the projection 21 from the adjacent socket 20 and as soon as the 
slide 2 has been caused to move the projection 21 into register with 
another selected socket 20. The operator then releases the torque applying 
force upon the wheel 180 or turns the wheel in the opposite direction to 
assist the spring 66 in propelling the projection 21 into the newly 
selected socket 20. At the same time, the projection 64 enters the 
corresponding recess 40. 
The lever 3 carries an additional lever 84 which, however, is not caused to 
automatically pivot relative to the lever 3 when the slide 2 is abruptly 
accelerated in the direction of arrow a. Instead, the additional lever 84 
is pivotable by a motion transmitting means including a link train 86, 88 
which receives motion from the wheel 180. The arrangement is such that the 
additional lever 84 is caused to pivot relative to the lever 3 and to 
enter the adjacent socket 20 when the wheel 180 of the means for pivoting 
the lever 3 is caused to assume its inoperative position. FIG. 6 shows the 
wheel 180 in the operative position (i.e., the projection 21 is held away 
from the adjacent socket 20 against the opposition of the coil spring 66), 
and the link train 86, 88 maintains the additional lever 84 in a 
depression or recess of the lever 3. Therefore, the operator can move the 
slide 2 along the track 1a in the guide 1 in order to place the projection 
21 into a position of register with a freshly selected socket 20. The 
additional lever 84 is then pivoted relative to the lever 3 (e.g., under 
the action of a coil spring 184 which is shown in FIG. 7). If the spring 
66 is free to bias the projection 21 toward the inner side 19a of the 
sidewall 19 but the projection 21 is not in alignment with a socket 20, 
the additional lever 84 also abuts the inner side 19a of the sidewall 19. 
If the vehicle embodying the apparatus of FIGS. 6-7 is involved in an 
accident during which the slide 2 is abruptly accelerated in the direction 
of arrow a, the spring 184 propels the free end portion of the additional 
lever 84 into the nearest socket 20 (see FIG. 7) whereby the lever 84 
tends to pivot the lever 3 in a clockwise direction to thereby positively 
propel the projection 21 into the nearest socket 20 as the slide 2 
continues to advance in the direction of arrow a. 
The wheel 180 has limited freedom of angular movement relative to the pivot 
member 4 in order to ensure that the additional lever 84 can be pivoted 
relative to the lever 3 while the wheel turns with reference to the pivot 
member 4 and lever 3. To this end, the pivot member has peripheral grooves 
90 for inwardly extending protuberances or claws 92 of the wheel 180. The 
claws 92 extend into the respective grooves 90 with a certain amount of 
clearance which is necessary to enable the wheel 180 to turn with 
reference to the pivot member 4 in order to actuate the link train 86, 88 
but without changing the angular position of the lever 3. 
An advantage of the apparatus which is shown in FIGS. 6 and 7 is that it is 
not necessary to provide a complex device for pivoting the lever 3 
relative to the slide 2 and guide 1. Thus, the wheel 180 is simply placed 
onto and can transmit torque to the pivot member 4 in order to change the 
angular position of the lever 3 with simultaneous stressing of the spring 
66. 
Problems can develop if the occupant restraint system of an automotive 
vehicle is equipped with a tensioning device for the shoulder belt. The 
tensioning device is likely to unduly accelerate the slide 2 in the event 
of an accident so that, if the projection 21 was not received in a socket 
20 at the time the accident occurred, the highly accelerated slide 2 is 
likely to propel the projection 21 beyond the nearest socket 20 and the 
spring 23 or 66 will be unable to pivot the projection 21 during the short 
interval which elapses while the rapidly moving projection 21 is ready to 
enter a socket 20. The aforementioned stop 75 can be said to constitute a 
safety device which compels the projection 21 to enter the last socket 20 
while simultaneously preventing total separation of the slide 2 from the 
guide 1. The ramps 62 and the surfaces 60 also contribute to greater 
reliability of penetration of the projection 21 into the nearest socket 
20. 
The lever 82 constitutes an additional safety device which is actuated in 
the event of an accident (involving abrupt acceleration of the slide 2 in 
the direction of arrow a) to reliably propel the projection 21 into the 
nearest socket 20. As mentioned above, rapid acceleration of the slide 2 
in the direction of arrow a can take place in response to the action of 
the aforementioned belt tensioning device when the vehicle embodying the 
apparatus of the present invention is involved in an accident. The 
additional lever 82 is caused to leave its depression or recess in the 
lever 3 and to assume the broken-line position of FIG. 4 to thus engage 
the nearest surface 60 and to pivot the lever 3 in a direction to propel 
the projection 21 into the nearest socket 20. 
The additional lever 84 in the apparatus of FIGS. 6 and 7 can be said to 
constitute a safety device which is used in lieu of the additional lever 
82 of FIGS. 4 and 5. The difference is that the wheel 180 can be used to 
move the lever 84 into the adjacent socket 20 (by way of the link train 
86, 88) irrespective of whether or not the projection 21 extends into the 
adjacent socket 20. The lever 84 is retracted into the depression or 
recess of the lever 3 when the wheel 180 is caused to assume its operative 
position, i.e., when the slide 2 is ready to be moved along the track 1a. 
When the wheel 180 is released, the spring 184 propels the lever 84 to the 
position of FIG. 7 so that this lever is bound to engage the nearest 
surface 60 when the slide 2 is propelled in the direction of arrow a 
whereby the lever 84 pivots the lever 3 which causes its projection 21 to 
penetrate into the nearest socket 20. If the wheel 180 is released while 
the projection 21 is not received in a socket 20 and while the free end of 
the additional lever 84 merely abuts the inner side of the sidewall 19, 
the lever 84 is compelled to penetrate into the nearest socket 20 as soon 
as it strikes the respective surface 60. In addition, the nearest ramp 62 
of the sidewall 19 enables the spring 184 to pivot the lever 84 in a 
clockwise direction even before the lever 84 reaches the nearest surface 
60. This even further enhances the likelihood of pivoting the lever 3 by 
way of the lever 84 in a direction to propel the projection 21 into the 
nearest socket 20 while the slide 2 is caused to abruptly advance in the 
direction of arrow a. 
Without further analysis, the foregoing will so fully reveal the gist of 
the present invention that others can, by applying current knowledge, 
readily adapt it for various applications without omitting features that, 
from the standpoint of prior art, fairly constitute essential 
characteristics of the generic and specific aspects of my contribution to 
the art and, therefore, such adaptations should and are intended to be 
comprehended within the meaning and range of equivalence of the appended 
claims.