Elastic and sliding locking device for disc brake with a floating caliper supported by a single axial pin, and disc brake equipped with such a device

The device (10), mounted elastically for example on a projecting part (30) of the caliper adjacent a projecting part (8) of the fixed support (5), incorporates a flat leaf surface (15) intended to be interposed between the cooperating slide surfaces of the caliper (31) and the support (82) and formed at the end of an intermediate leaf zone forming a flexible ramp surface (14) which cooperates, when fitting the caliper into position, with the adjacent part (8) of the fixed support (5) so as to cause the flat surface (15) to deflect and thus ensure automatic locking of the caliper, the unlocking being easily achieved manually by a similar retraction of the flat slide surface (15). The device (10) is made in a single piece from a sheet of stainless spring steel.

The present invention concerns disc brakes and, more particularly, elastic 
sliding and locking devices for disc brakes of the type with a floating 
caliper slidingly mounted on a fixed support by means of a single axial 
pin or column firmly fixed to the caliper or to the fixed support, which 
elastic sliding and locking device is capable of being inserted between 
one end of the caliper opposite the pin and and adjacent part of the fixed 
support by being mounted on the first of a pair of components consisting 
of this end of the caliper and this adjacent part of the fixed support, so 
as to co-operate in guiding the sliding of the two components relative to 
one another by coming into contact engagement, over an engagement portion, 
against adjacent slide zones of each of these two components in the normal 
operating position of the brake, at least this engagement portion of the 
sliding and locking device being capable of being deflected, e.g. 
retracted elastically so as to allow the caliper to pivot about the pin in 
the vicinity of this normal operating position. 
The general construction of a disc brake with a floating caliper sliding on 
a single pin is described in European Patent Application No. 0,030,502 in 
the name of the applicant, and whose contents are integrated herewith for 
reference. 
A disc brake of this type, provided with an elastic sliding and locking 
device of the type defined above, is also the subject of European Patent 
Application No. 0,036,368, again in the name of the applicant. In this 
document, the elastic sliding and locking device, with which slidingly 
cooperate bearing faces of the caliper and of the fixed support which are 
opposing and are off-set axially, consists of a spring of cylindrical wire 
having one end fixed to the inside of the caliper and a straight portion 
running along the length of the end of the caliper opposite the single 
pin, in such a way that it presents an end of a free arm capable of being 
retracted, e.g. deflected or displaced towards the caliper when the latter 
pivots towards its normal operating position, by co-operating with a ramp 
surface formed on a protruding part, adjacent to this end of the caliper, 
of the fixed support. The free end of the lateral arm of the spring is 
locked in an engagement position with the bearing face of the protruding 
part of the fixed support by a safety pin. Although giving complete 
satisfaction, this arrangement presents the disadvantage that the sliding 
zones of the caliper and of the fixed support sliding on the spring wire 
interposed therebetween are limited to the outlines, e.g. generatrices of 
the cylindrical spring which may thus groove the material of the caliper, 
which is generally made of light alloy, for example of aluminum. In 
addition, the fitting of the spring in position dictates a particular 
configuration for the end of the caliper, and the safety pin also forms an 
addtional component which must be fitted or removed when ratchetingly 
fitting the caliper in position or when subsequently raising it again, for 
example in order to change the brake pads. 
British Pat. No. 1,532,572 on the other hand proposes an arrangement for a 
brake construction of the type described above which makes use, according 
to a technique which is well known in conventional disc brakes with a 
floating caliper, of a retaining and sliding key interposed between the 
end of the caliper and the adjacent part of the fixed support, thus 
providing optimum slide surfaces between these two components. However, 
withdrawing of this key requires the removal of the two safety pins at its 
two ends and the removal of the key by axial displacement thereof. 
One object of the present invention is to propose an elastic and sliding 
locking device for disc brakes of the type defined above, which is of 
simple construction, is simple to fit into position and to remove, whose 
operation is reliable, and which provides improved slide surfaces between 
the caliper and the fixed support. 
To achieve this, according to a feature of the present invention, the 
elastic sliding and locking device is made from a spring steel sheet, the 
engagement portion of this device consisting of a flat slide leaf surface 
connected to a mounting body portion for mounting the device by an 
intermediate leaf zone forming a flexible inclined ramp surface diverging 
from the body portion and arranged so as to co-operate with the second 
relatively sliding component (caliper or fixed support) to achieve the 
retraction of the engagement portion during the pivoting of the caliper 
towards its normal operating position. 
With this arrangement, the flat engagement portion of the device, with 
whose opposite faces the slide zones of the caliper and of the fixed 
support cooperate in sliding engagement, acts as a slide key forming an 
integral part of a device which further achieves an elastic locking 
function permitting the caliper to be fitted in place by simple ratcheting 
at the end of its pivoting movement, while allowing, by simple deflection 
of the intermediate leaf zone, with a screwdriver for example, the 
retraction of the engagement portion so as to permit separation of the end 
of the caliper from the fixed support and to allow the assembly of the 
caliper and pads to be pivoted about the single pin. 
Another object of the present invention is to provide a disc brake of the 
type defined above, of simple construction and reliable operation, 
arranged to accept said elastic and sliding locking device. 
To achieve this, according to a feature of the invention, in a disc brake 
of the type defined above, wherein the caliper is provided with a part 
which projects outward from said end of the caliper in the region of said 
adjacent part of the fixed support and forming said slide zone of the 
caliper, the body portion of the elastic and sliding locking device is 
mounted on the first component in such a way that the intermediate zone 
forming a flexible inclined ramp surface extends into the region of the 
projecting part of the caliper towards the second component, with which 
this flexible intermediate zone can thus cooperate so that it bends when 
the caliper pivots towards its operating position, thus providing 
automatic positioning, with locking, of the caliper.

In the following description and drawings, identical or similar components 
are identified by same reference numbers, if appropriate with primes. 
As shown in the figures, a disc brake of the type with a floating caliper 
mounted so as to slide on a single axial pin according to the invention 
consists essentially of a caliper body 1 in which are mounted friction 
pads 3, 3' either side of a rotating disc 2, and incorporating a hydraulic 
piston 4 which acts upon the inner pad 3' against the disc 2 and, by 
reaction, upon the outer pad 3 against the other face of the disc. The 
caliper 1 is mounted so as to slide on a fixed support 5, for example a 
yoke, by means of a single axial pin 6 firmly fixed to the caliper or to 
the fixed support and slidingly received within a tubular housing 7 in the 
body of the fixed support or of the caliper. In FIGS. 2, 10, 14, and 16 
the support pin is fixed to the body of the fixed support 5, while as a 
variation, in FIG. 3, this support pin 6 is shown to the caliper 1. The 
end portion of the caliper opposite the pin 6 is normally positioned in 
the vicinity of an adjacent part 8 of the support body 5, these two 
adjacent components being arranged to co-operate with an elastic sliding 
locking device 10 according to the present invention. 
For this purpose, the adjacent part of the support body 5 is provided, 
slightly set back from the outside arm of the caliper 1, with a projecting 
part 8 which extends axially in the region of the adjacent end of the 
caliper. This projecting part 8 of the support 5 is provided with an upper 
inclined surface 81, diverging upwards away from the caliper, extended 
downwards by a recess which defines a slide surface 82 facing downwards 
and extending substantially in an horizontal plane, parallel to the axis 
of the brake disc as embodied by the axes Ox and Oy, and an offset 
abutment surface 83 which extends in a plane substantially perpendicular 
to the horizontal plane mentioned above and embodied by the axes Oy and 
Oz. 
In the embodiments shown in FIGS. 1 to 7 and 13 and 14, the end portion of 
the caliper 1 opposite the support pin 6 is provided with a projecting 
part 30 extending outwards in a direction opposite to the pin 6 and 
provided with an upper flat surface 31 arranged so as to extend, in the 
normal operating position of the brake, in a horizontal plane xy 
substantially coincident with the horizontal plane of the face 82 of the 
projection 8 of the fixed support 5, as may be seen more clearly in FIGS. 
4 and 5. In these embodiments, the projecting part 30 of the caliper is 
provided with a thickened installation zone of cubic configuration having 
a length, outwards, less than the distance normally separating the end of 
the caliper from the edge of the projecting part 8 of the fixed support 5 
as defined by the surfaces 81 and 82. 
The projecting part 30 is provided with an end 32 extending outwards 
laterally relative to the projecting part 8 of the support 5, a clearance 
e normally being provided between the lateral inner face of the end 32 and 
the adjacent lateral outer face of the projecting part 8 when the brake is 
equipped with new linings, as may be seen in FIG. 3. The end 32 terminates 
in a front face 33 extending, in the normal operating position of the 
brake, in a plane parallel to the plane yz and thus to the recessed face 
83 of the projecting part 8 of the fixed support 5, the outwards extension 
of the end 32 of the projecting part 30 in the direction x being less than 
the distance normally separating in this direction x, the offset face 83 
from the adjacent end of the caliper 1. 
In this way, in the normal operating position, as the brake progressively 
wears, when the caliper moves relative to the fixed support 5, the 
projecting part 30 can engage in the recess formed by the faces 82 and 83 
of the projecting part 8 of the support 5, as shown diagrammatically in 
FIG. 7. 
In the embodiment of the sliding and locking device 10 according to the 
invention shown in FIGS. 1 to 7, the latter consists of a body portion 11 
which is essentially of cubic configuration with a bottom web 12 and two 
rear flaps 13 folded to form a closed U, the bottom web 12 being extended 
outwards by an intermediate leaf zone 14 of reduced width (in the 
direction y) extending upwards and outwards away from the flaps 13 (in the 
direction x) so as to form an inclined and flexible ramp surface, this 
intermediate leaf zone 14 being extended in turn, at its upper end, by a 
flat leaf surface 15 extending in a plane parallel to that of the bottom 
web 12 over the whole width (in the direction y) of the device 10. The 
leaf surface 15 is, in turn, extended by an end portion 16 folded upwards 
so as to extend in a plane which is essentially perpendicular to that of 
the leaf surface 15. The whole of the device 10 is made in a single piece 
from a sheet of stainless spring steel stamped and formed to the 
configuration shown. This device 10 is fitted into position on the 
projecting part 30 of the caliper in the manner shown, that is to say by 
elastically inserting the body portion 11 onto the base of the projecting 
part 30, the intermediate leaf zone 14 thus extending in the region of the 
end 32 of the projecting part and the flat leaf surface 15 extending in a 
plane parallel to that of the upper surface 31 of the projecting part 30, 
slightly above the latter. As may be seen in FIGS. 6 and 7, the extension 
in the direction x of the flat leaf surface 15 is such that, the device 10 
being mounted on the projecting part 30 of the caliper, the leaf surface 
15 extends outwards beyond the edge of the projecting part 8 of the 
support 5 defined by the faces 81 and 82. However, according to the 
invention, when the caliper 1 pivots about the support pin 6 in the 
direction from its desengaged position to its normal operating position, 
indicated by the arrow in FIG. 2, the intermediate leaf zone 14 forming a 
ramp surface comes into contact with the edge of the projecting part 8 and 
bends about its lower zone of attachment to the bottom web 12 towards the 
caliper so as to cause in this way the flat leaf surface 15 to be 
retracted and to permit the completion of the downward pivoting of the 
caliper. On the other hand, as soon as the plane of the flat leaf slide 
surface 15 has passed the edge formed by the faces 81 and 82, by virtue of 
the elasticity of the material of the device 10, the slide surface 15 
substantially recovers its initial position in sliding engagement contact 
with the slide face 82 of the projecting part 8, as may be seen in FIGS. 4 
and 5. In accordance with the aim of the invention, the device 10 thus 
ensures automatic locking of the caliper 1 in its normal operating 
position relative to the adjacent end 8 of the fixed support 5, whereas 
the flat leaf surface 15, interposed between the upper face 31 of the 
projecting part 30 of the caliper and the face 82 of the projecting part 8 
of the support 5, which co-operate with the opposite faces of the leaf 
surface 15, acts as a sliding key "bridging" the two movable components 
one relative to the other in the initial configuration with the brake 
provided with new linings, in the same way, ultimately, as the linings 
wear, when the projecting part 30 of the caliper comes into engagement 
below the face 82 of the projecting part 8. In this latter configuration, 
to prevent the caliper becoming skew or tilted when it is displaced, the 
dimensions of the projecting part 30 of the caliper are arranged so that 
the front face 33 of the end 32 of this projecting part comes into bearing 
engagement with the recessed abutment face 83 of the projecting part 8 of 
the support body. In a preferred embodiment, to prevent, in these 
conditions, hammering of the end 32 of the projecting part (made of light 
alloy whereas the support body 5 is typically made of cast iron for 
example), the body portion 11 of the device 10 is provided with a flap 18 
folded upwards from the bottom web 12 adjacent flexible leaf zone 14 and 
is thus interposed between the front face 33 and the abutment face 83. 
The embodiment of the device 10 shown in FIG. 8 differs from that described 
above, in that the body portion 11, insted of forming a prismatic box 
fitted over the projecting part 30 of the caliper 1, is prolongated 
opposite the flexible leaf zone 14, by a web 110 folded upwards relative 
to the bottom web 12 (and thus parallel to the end portion 16, at a 
distance therefrom). In the web portion 110 is cut a window 111 of a 
general rectangular shape with ears 112 extending inwards which apply 
elastic retaining pressure when the projecting part 30 is force fitted 
into the window 111. As for the previous embodiment, the web portion 12 
may advantageously be provided with a flap 18 folded upwards which extends 
in front of the front face 33 of the end 32 of the projecting part 30. 
In the embodiment shown in FIGS. 9 to 12, the projecting part of the 
caliper is divided into two portions 30' separated laterally from one 
another, the projecting part 8 of the fixed support 5 then presenting a 
reduced lateral width to be interposed, in the normal operating position 
of the caliper provided with new linings, between these two portions 30' 
protruding from the caliper, as may be seen in FIGS. 10 and 12. The 
corresponding sliding and locking device 10 is modified accordingly. It 
incorporates a body portion similar to that of the embodiment in FIG. 8, 
the flexible intermediate leaf zone 14 being formed centrally and the flat 
leaf slide surface 15 extending laterally symmetrically either side of 
this intermediate flexible zone 14, as may be clearly seen in FIG. 9. In 
these conditions, as shown in FIG. 12, in the initial configuration, the 
slide leaf surface 15 co-operates, at its two ends, its lower face with 
the upper slide surfaces 31 of the two portions 30' of the projecting 
parts of the caliper, and its upper face centrally with the face 82 of the 
projecting part 8 of the fixed support 5. According to an aspect of the 
invention, the body portion 111 forms, in this embodiment, a flexible leaf 
113 extending parallel to the plane of the flat surface 15 between the 
upwardly folded end portion 16, and the end web 110 of the body portion 11 
so as to provide in this way a releasable locking for the flat slide leaf 
surface 15 to prevent undesirable retraction of the latter. Hence as in 
the preceding embodiments, during the fitting into position of the caliper 
1 by pivoting towards its normal operating position, the retraction of the 
leaf surface 15, resulting from the bending of the flexible intermediate 
leaf zone 14 co-operating with the projecting part 8 of the fixed support 
5, is only permitted on condition that the locking leaf 113 is previously 
bowed upwards to allow the end portion 16 to clear towards the rear, which 
otherwise would immediately come into abutment against the locking leaf 
113 in its rest position. 
A simplified embodiment of the device 10 according to the invention is 
shown in FIGS. 13 and 14. In this variant, instead of being elastically 
mounted on the projecting part 30 of the caliper (which is reduced, in 
this variant, to a parallelepiped of a section corresponding to the end 
32), the device 10 has a body portion 11 reduced to a leaf 115 
prolongating the flexible intermediate leaf zone 14 and extending in a 
plane substantially perpendicular to that of the flat leaf surface 15, 
this leaf portion 115 being provided with a hole 116 for mounting it onto 
the end of the caliper 1 by means of a splined nail 500. 
In the different embodiments described above, the end portion 16 
prolongating the flat slide leaf surface 15 of the device 10 serves for 
unlocking the device so as to release the caliper 1, by pivoting, from the 
fixed support 5, for example in order to inspect the pads or to replace 
them. Thus, by applying pressure, with a screwdriver for example, between 
the edge of the projecting part 8 of the support 5 and this end protion 16 
of the device 10, this end portion may thus be pushed towards the caliper, 
thus releasing the flat leaf surface 15 from the slide face 82 of the 
projecting part 8 of the support 5 so as to pivot the caliper away from 
this projecting part 8. 
In the embodiment shown in FIGS. 15 to 18, the sliding and locking device 
10 is in this case mounted on the projecting part 8 of the support body 5. 
For this purpose, the projecting part 8 is provided with a boss 80 
extending upwards and having an upper flat surface 810 parallel to the 
plane xy mentioned above and a rear shoulder with a mounting face 820 
perpendicular to said face 810. In this embodiment, the device 10 is still 
provided with a flat leaf surface 15 (not incorporating in this case a 
folded end portion 16) connected by the intermediate zone 14 forming a 
flexible ramp to a body portion 11 which is reduced to a flat surface 117 
extending into an end flap 118 folded downwards, perpendicular to the 
latter, towards the flat slide surface 15, and provided with a hole 119. 
The device 10 is thus installed on the boss 80 with the flat surface 117 
bearing against the upper face 810 of the boss and the end flap 118 
bearing against the rear face 820 of the boss, to which it is firmly fixed 
by means of a splined nail or rivet 500 passing through the hole 119. In 
this embodiment, as may be clearly seen in FIGS. 16 and 18, the projecting 
part 300 of the caliper 1 is not provided with an end 32 extending 
laterally, in the normal initial position, next to the projecting part 8 
of the support 5, this projecting part 300 being reduced to the root 
portion of the projecting part 30 of the embodiment shown in FIGS. 1 to 7, 
that is to say having a reduced extension outwards which permits it to 
pass through the gap arranged between the end of the body of the caliper 1 
and the edge of the adjacent projecting part 8 of the support 5. In this 
embodiment, during the fitting into position of the caliper by pivoting 
towards its normal operating position, it is the lower edge 301 of the 
projecting part 300 which co-operates with the flexible intermediate leaf 
zone 14 of the device 10 so as to push the flat leaf surface 15 outwards, 
below the slide face 82, as indicated by the arrow E in FIG. 18, after 
which, when the upper slide surface 31 of the projecting part 300 has 
passed the horizontal plane of the leaf surface 15, the latter 
substantially recovers its initial position for forming a key between the 
opposing slide surfaces 82 of the projecting part 8 of the support 5 and 
31 of the projecting part 300 of the caliper 1 (which, unlike the previous 
embodiment, as the linings were, no longer comes into engagement below 
this slide face 82 of the projecting part 8 of the support 5). As 
illustrated in FIG. 18, to unlock the caliper, it is here only necessary 
to insert a screwdriver 400 between the flexible intermediate leaf zone 14 
and the adjacent end of the caliper body 1 so as to push the sliding and 
locking flat leaf surface 15 of the device 10 in the direction of the 
arrow E and thus permit the caliper 1 to pivot away from the support 5. 
Although the present invention has been described in relation to particular 
embodiments, it is not limited by them, but on the contrary is capable of 
modifications and variants which will be apparent to those skilled in the 
art.