The device concerns a switch, in particular a self-adjusting pedal-box
switch, with facilities for self-adjustment of the switch during mounting, and
with adjustment protection. The switch is inserted into a pedal box panel above
the pedal shaft, and perpendicular to the plane of the pivot bearing of the moveable
During vehicle assembly, when installing switches which are used in
particular to monitor the positioning of clutch or brake pedals and as brake light
switches, many problems occur with the adjustment needed to ensure correct operation.
This applies in particular to accurate adjustment of the switch position and contact
travel required to take account of the tolerance involved in manufacture of the
pedal housing. This leads to the need for switches with adjustable lengths which
often fail to provide the required precision. Moreover, installation and adjustment
of such switches is time consuming and thus more expensive.
Self-adjusting switches can be prone to the following problems:
- Accidental or unintentional maladjustment during shipment of parts, vehicle
assembly or servicing;
- Fatigue or gradual slackening of the adjustment system;
- Maladjustment of the switch by excessive pressure on the pedal.
This has led to various designs of quick-fit, self-adjusting switches
which are often still not satisfactory.
Object of the invention is to develop a switch of the above mentioned
type with the capability of self-adjustment only at the time of installation and
with a simple construction so that it can be installed and adjusted for correct
functioning in a single operation during vehicle assembly.
This object is accomplished with a switch according to the generic
part of claim 1 with the following features:
- a) the switch has a housing with fixed contacts which are connected via terminals
to the outside of the housing,
- b) in the switch housing is a moveable contact bridge carrier, which pivots
on a spindle when the switch is installed and which is positioned parallel to the
pivot bearing spindle of the pedal body,
- c) the contact bridge carrier is constructed in two parts, consisting of a rotor
with a contact bridge, which is located in the switch housing and rotates against
the force of a return spring, and a swivel plunger, which can be adjusted incrementally
and which is pivoted on the same spindle as the rotor and works together with the
shaft of the pedal body or with a pedal flag attached to the pedal body,
- d) the rotor has external stops , which work together with moveable locking
pins on the switch housing, which are arranged perpendicular to the direction of
movement of the rotor, when the switch is mounted in the pedal box carrier, in
order to lock the rotor body until just before the switch reaches its final installed
- e) the locking pins on the switch housing are held in a locked position by the
edges of an U-shaped mounting slot in the pedal box carrier, when the switch is
inserted into the slot, and are released by clearance notches in the mounting slot
when the switch is in its final installed position.
Specific advantageous developments of the invention are found in the
patent claims 2 to 10.
The device has the advantage that these switches cannot accidentally
or unintentionally be maladjusted before it is installed. Furthermore, when the
switch, in the condition as when delivered by the manufacturer, is installed in
the vehicle in a prepared mounting slot in a suitable carrier (for example in a
pedal box carrier), the moveable switch parts are automatically adjusted so that
after installation the switch is fully adjusted and ready for operation. The return
spring for the rotor of the contact bridge carrier ensures that before the installation
of the switch, the contact bridge carrier is in the correct position for the adjustment
of the switch when the switch is mounted. This adjustment is achieved by the swivel
plunger, which is secured by a ratchet on the rotor in its delivered state, touching
the pedal body, or a flag mounted on the pedal body, via the rotor. The
rotor is secured in its delivered state by the locking pins on the switch housing,
which are pushed inwards by the long edges of the mounting slot during insertion
of the switch. Therefore the rotor cannot rotate with the swivel plunger during
the automatic adjustment of the swivel plunger to its end position. The adjustment
protection for the rotor of the contact bridge carrier is maintained until the
switch has reached its installed position in the pedal box carrier. At this time
the locking pins, which up to now have secured the rotor of the contact bridge
carrier in the switch housing against accidental or unintentional adjustment, are
released by a clearance notch in the long edges of the mounting slot and free the
rotor of the contact bridge carrier for turning during in-service operation of
the switch. At the same time the switch is locked in its installed position by
engagement of the locking pins in the clearance notches directly opposite each
other on the long edges of the mounting slot.
A preferred embodiment of the invention is shown in the drawings.
- Fig. 1
- shows a perspective view of a switch with arrangement for self-adjustment during
assembly in a pedal box carrier,
- shows a vertical longitudinal section through the switch in the delivered state
ready for assembly and the transverse section of Fig. 2 is shown by cutting line
II-II in Fig. 3,
- shows another section through the switch according to the cutting line III -
III in Fig. 2 and
- shows a perspective exploded view of the switch components.
The switch 1 according to Fig. 1 to 4 serves in particular to indicate
the functioning position of foot pedals in vehicles and especially when used as
a brake light switch.
The switch 1 has an arrangement for self-adjustment only during assembly
of the switch into the pedal box carrier 2 that is mounted above the pedal shaft
5 perpendicular to the plane of the pivot bearing 3 of a moveable foot pedal body
The switch 1 has a housing 6 with fixed contacts 7 that are connected
to the terminals 7a (Fig. 4) on the exterior of the housing.
There is a moveable contact bridge carrier 8 in the switch housing
6 which is pivoted on a spindle 9, which is parallel to the to the pivot bearing
spindle 3 of the pedal body 4 when in the installed position.
The contact bridge carrier 8 is constructed in two parts: a contact
bridge 12 with a rotor 11 which rotates against the force of a return spring 10
and, inside the rotor 11, a swivel plunger 13 which can be adjusted incrementally
and which is pivoted on the same spindle 9 as the rotor 11.
The return spring 10 is a compression coil spring or torsion spring
with one end 10a supported on the inside of the switch housing 6 and the other
end 10b on the rotor 11.
During normal operation the rotor 11 and the swivel plunger 13 are
fixed together. The rotor 11 has external lugs 14 which, during the mounting of
the switch 1 onto the pedal box carrier 2, work together with the moveable locking
pins 15 on the switch housing 6. The locking pins 15 are perpendicular to the direction
of movement of the rotor 11. In this way the rotor body 11 is secured by the locking
pins 15 until shortly before reaching the final installed position.
The locking pins 15 on the switch housing 6 are moved into the locking
position for the rotor 11, by insertion of the switch into the U-shaped mounting
slot 16 in the pedal box carrier 2. The locking pins 15 are released by the clearance
notches 16a (Fig. 1) in the mounting slot when the switch is in the final installed
The switch housing 6 is constructed in two parts - a bottom housing
section 17 with the spindle 9 for the contact bridge carrier 8 that includes a
rotor 11 and swivel plunger 13, and a top housing section 18 with the contacts
7, 7a fixed to the housing and a support for the return spring 10 for the contact
bridge carrier 8.
On the bottom housing 17 there are parallel, U-shaped external guide
rails 19, 20 which overlap the edges of the U-shaped mounting slot 16 on the pedal
box carrier 2, and serve to secure the switch 1 in the installed position in the
pedal box carrier 2.
The locking pins 15 for the rotor 11 are formed from the eye-shaped
ends 22 of a U-shaped fastening spring 21. The eye-shaped ends 22 protrude through
slots 23 in the form of guide openings in the side walls of the bottom housing
17 (Fig. 3 and 4) between the guide rails 19, 20, and are pushed inwards by the
long edges of the mounting slot 16 during insertion to the end stop.
The switch housing 6, the rotor 11 and the swivel plunger 13 of the
contact bridge carrier 8 are made in the form of a sector of a circle, referenced
to their spindle 9.
The rotor 11 of the contact bridge carrier 8 is constructed as a hollow
body with a cut-out for the swivel plunger 13 and has inward facing ratchet teeth
24 that engage with the protruding spring-loaded indexing pin 25, radial to the
spindle 9, on the outer circumference of the swivel plunger 13.
Moreover, the rotor 11 of the contact bridge carrier 8 is guided by
separate guide lugs 30 (Fig. 4) sliding in arc-shaped slots on the inner side of
the switch housing 6.
A radial lug 26 on the rotor 11 serves as anchorage for the contact
The swivel plunger 13 is incrementally adjustable along the ratchet
teeth 24 between two end stops in the cut-out of the rotor 11. Furthermore, it
has an outward facing guide shoe 27 to position it on the shaft 5 of the pedal
body 4 or an attached flag 28. During the operation of the switch, the guide shoe
27 also serves as an end stop for the movement of the contact bridge carrier against
the switch housing 6.
During the installation of the switch 1 into the mounting slot 16
of the pedal box carrier in the direction of the arrow 29 in Fig. 1, the following
sequence of events occur:
During the insertion of the switch 1 into the mounting slot 16 in
the direction of the arrow 29 in Fig. 1, the locking pins 15 of the U-shaped fastening
spring 21, which protrude outwards between the parallel guide rails 19, 20 of the
switch housing 6, are pushed together by the long edges of the mounting slot 16
in the pedal box carrier 2. During this action the swivel plunger 13 of the switch
1 meets the flag 28 or a projection on the shaft 5 of the pedal body 4 and is thereby
gradually pushed into the cavity of the rotor 11.
As the swivel plunger 13 is bound with the rotor 11 by the indexing
pin 25 engaging with the inner ratchet 24 of the rotor 11, the rotor 11 moves with
the swivel plunger 13 through a distance "T" in Fig. 3, until the two side stops
14 on the outside of the rotor 11 contact the locking pins 15 of the fastening
spring 21 thus preventing the rotor 11 from being pushed further into the switch
When the switch 1 is pushed further into the mounting slot 16 the
force on the swivel plunger 13 increases, and the indexing pin 25 moves over the
ratchet 24 on the rotor, and is thus automatically adjusted.
Immediately before the switch 1 reaches the end of the mounting slot
16 the locking pins 15 are released.
In this manner, the adjustment range "L" of the swivel plunger 13
(Fig. 2) relative to the rotor 11 is set to the required distance in a single operation,
without any risk that the switch 1 could be later put out of adjustment during
the life of the vehicle. During shipment of the switch, the locking pins 15 are
not activated so that the swivel plunger 13 cannot be set prior to assembly in
the vehicle. The switch 1 can, however, be readjusted by pulling back the swivel
plunger 13 with a force greater than that required to set the length adjustment.
It should be noted that the force required to depress the pedal body
4 with the pedal flag 28 is much greater than the force required for the operation
of the switch 1 and for setting its length adjustment. Therefore the pedal flag
28 can be considered as being rigid.
List of reference numbers
- pedal box carrier
- pivot bearing spindle
- pedal body
- pedal shaft
- switch housing
- contact bridge carrier
- return spring
- end of spring
- end of spring
- contact bridge
- swivel plunger
- locking pin
- mounting slot
- clearance notch
- bottom housing
- top housing
- guide rail
- guide rail
- fastening spring, stopper spring
- ends of fastening spring
- locking ratched, internal teeth
- indexing pin
- radial lug
- guide shoe
- pedal flag
- arrow, insertion direction
- guide lugs
- dimension in Fig. 3
- adjustment range in Fig. 2