FR 3081804 A1 20191206 FR 1905904 A 20190604 Description Titre de l'invention : Connection device for connecting a push-rod to a control member, such as a control pedal of a vehicle [0001] The present invention relates in general to a connection device for connecting a push- rod to a control member, such as a control pedal of a vehicle (particularly, although not necessarily, a brake pedal). [0002] More specifically, the present invention relates to a connection device comprising a cage structure integral with the control member, the cage structure having a ball socket adapted to receive a ball head provided at an end of the push-rod; a fixing element which is releasably mounted in the cage structure and is provided with first and second elastically deformable locking means, wherein said first locking means are shiftable between an elastically deformed condition, in which they allow the ball head of the push-rod to be inserted into the fixing element, along an insertion direction substantially coinciding with the longitudinal axis of the push-rod, until the ball head engages in the ball socket, and an undeformed condition, in which they retain the ball head of the push-rod in the ball socket and hence in the fixing element, once the ball head is engaged in the ball socket, and wherein said second locking means are shiftable between an elastically deformed condition, in which they allow the fixing element to be inserted into the cage structure along the aforementioned insertion direction, and an undeformed condition, in which they retain the fixing element in the cage structure once the fixing element has been inserted into the cage structure; and third locking means for holding said second locking means in said undeformed condition, thereby preventing disengagement of the fixing element from the cage structure once the ball head of the push-rod is engaged in the ball socket. [0003] A connection device of the above-identified type is known from EP 1 787 878 Al. [0004] According to this known example, the fixing element has a generally parallelepiped shape and the aforementioned second locking means are formed by a pair of elastically deformable pawls provided on two opposite sides of the fixing element, while the aforementioned first locking means are formed by a pair of elastically deformable tabs provided on the other two opposite sides of the fixing element. The aforementioned third locking means are formed by the ball head of the push-rod which, once inserted into the fixing element to engage the respective ball socket, rests against respective faces of the pawls in such a manner as to keep said pawls locked in the undeformed condition in which they retain the fixing element in the cage structure. Each pawl must cooperate with the ball head to be held by the latter in the undeformed condition, and therefore it is positioned substantially in the centre of the respective side of the fixing 2 element, i.e. substantially at the same distance from the other two opposite sides of the fixing element where there are provided the elastically deformable tabs for retaining the bail head in the fixing element. Such an arrangement of the pawls, however, does not ensure that the fixing element is securely retained in the cage structure, so there is still the risk that the push-rod be disconnected from the cage structure, and hence from the control member, in case high tension forces are applied on the same. [0005] It is therefore an object of the present invention to provide a connection device for connecting a push-rod to a control member, such as a pedal of a vehicle, which ensures a more secure connection of the push-rod with the control member than the abovediscussed prior art. [0006] This and other objects are fully achieved according to the invention by virtue of a connection device of the above-identified type, wherein the second locking means include a pair of first elastically deformable pawls on a first side of the fixing element and a pair of second elastically deformable pawls on a second side of the fixing element opposite to the first one, and wherein the third locking means include a pair of locking inserts which are made as separate pieces with respect to the bail head of the push-rod and are carried by the fixing element, on opposite sides of the bail head, said locking inserts being slidable relative to the fixing element, in a direction parallel to the aforementioned insertion direction, from a non-working position, in which each locking insert protrudes from the fixing element, to a working position, in which each locking insert is fully received inside the fixing element and holds a respective first pawl and a respective second pawl in the undeformed condition, thereby preventing disengagement of said pawls, and hence of the fixing element, from the cage structure. [0007] By virtue of such a configuration, the connection device according to the present invention ensures a more stable and secure connection of the fixing element with the cage structure than the prior art. [0008] The invention also relates to a control system, particularly for a motor-vehicle, comprising a control pedal, a push-rod arranged to transmit to an actuation device, such as for example a brake servo of a vehicle braking system, a force imparted by the user (driver) through the control pedal, as well as a connection device arranged to releasably connect the push-rod to the control pedal. [0009] Further features and advantages of the present invention will become more apparent from the following detailed description, given purely by way of non-limiting example with reference to the appended drawings, wherein: [0010] [fig.1] is a side view showing a portion of a control pedal of a vehicle connected to a push-rod through a connection device according to an embodiment of the present invention. [0011] [fig.21 is a perspective view of the connection device of Figure 1. 3 [0012] [fig.31 is an exploded view of the connection device of Figure 1. [0013] [fig.41 is a section view of the control pedal of Figure 1, in the condition in which the push-rod is disconnected from the control pedal. [0014] [fig.51 [0015] [fig.61 show the connection device of Figure 1, with the locking inserts in the non- working position and in the working position, respectively. [0016] With reference to the drawings, numeral 10 generally indicates a control pedal of a vehicle, in particular (although not necessarily) a brake pedal, for controlling an actuation device (not shown), such as for example a brake servo of a vehicle braking system, through a push-rod 12 arranged to transmit to the actuation device the force imparted by the driver on the control pedal 10. The push-rod 12 is releasably connected to the control pedal 10 by means of a connection device, generally indicated at 14. [0017] The connection device 14 comprises a cage structure 18 integral with the control pedal 10. The cage structure 18 may be, for example, made in one piece with the control pedal 10, as in the embodiment shown in the drawings, or be made as a separate piece with respect to the control pedal 10 and then be firmly secured thereto (for example, by welding). [0018] The cage structure 18 has a generally parallelepiped shape, with an open side allowing insertion of an end portion of the push-rod 12 provided with a bail head 20 into the cage structure 18. On the side opposite to the aforementioned open side, the cage structure 18 has a bail socket 22 adapted to partially receive the bail head 20 of the push-rod 12 (as can be seen in Figure 1). [0019] With reference in particular to Figure 3, the bail socket 22 is preferably formed by a suitably shaped bottom element 24, which is made separately from the cage structure 18 and is received inside the cage structure 18 so as to close the side opposite to the aforementioned open side through which the end portion of the push-rod 12, carrying the bail head 20, is inserted into the cage structure 18. [0020] As shown in Figures 1 and 4, in order to insert the end portion of the push-rod 12 carrying the bail head 20 into the cage structure 18, the push-rod 12 is urged along its longitudinal axis x towards the cage structure 18. The direction of the longitudinal axis x will be hereinafter also referred to as insertion direction. [0021] The connection device 14 further comprises a fixing element, generally indic ated at 26, which is made as a separate element with respect to the cage structure 18 and is configured to be inserted into the cage structure 18 and releasably retained therein. [0022] With reference in particular to Figures 2, 3, 5 and 6, the fixing element 26 comprises an upper frame 28 of substantially rectangular shape, which in the assembled condition of the fixing element 26 in the cage structure 18 is positioned near the open side of that 4 structure. [0023] The fixing element 26 comprises a pair of elastically deformable tabs 30 which extend from a pair of opposite and parallel sides 28a of the upper frame 28 so as to converge towards the inside of the fixing element 26. The tabs 30 allow, by virtue of their elastic deformability, the bail head 20 to be inserted into the fixing element 26 until it is engaged in the bail socket 22. Once the bail head 20 is engaged in the bail socket 22, the tabs 30 return back to the undeformed condition (as shown in Figures 1 and 2), where they hold the bail head 20 preventing disengagement of the latter from the bail socket 22 and the fixing element 26. The tabs 30 act therefore as first elastically deformable locking means arranged to retain the bail head 20 of the pushrod 12 in the fixing element 26 once the bail head 20 is engaged in the bail socket 22. [0024] The tabs 30 are advantageously formed in one piece with the upper frame 28, for example by plastic injection moulding process. [0025] The fixing element 26 further comprises a pair of elastically deformable first pawls 32 which extend parallel to the insertion direction x from one of the aforementioned pair of opposite and parallel sides 28a of the upper frame 28, and are arranged on opposite sides of the tab 30 extending from that side 28a of the upper frame 28. Preferably, the first pawls 32 are connected to each other at their respective free ends by means of a first connecting bridge 34. Likewise, the fixing element 26 comprises a pair of elastically deformable second pawls 36 which extend parallel to the insertion direction x from the other one of the aforementioned pair of opposite and parallel sides 28a of the upper frame 28, and are arranged on opposite sides of the tab 30 extending from that side 28a of the upper frame 28. Preferably, the second pawls 36 are also connected to each other at their respective free ends by means of a second connecting bridge 38. The first and second pawls 32 and 36 are shaped in such a manner as to allow, by virtue of their elastic deformability, the fixing element 26 to be inserted into the cage structure 28 along the insertion direction x until it reaches a final assembled position (shown in Figures 1, 5 and 6), in which the first and second pawls 32 and 36 engage in corresponding scats 40 (shown in Figures 1 and 3) of the cage structure 18 and thus retain (although in a releasable manner) the fixing element 26 in the cage structure 18. [0026] The first and second pawls 32 and 36 are thus elastically shiftable between a deformed condition, in which they allow the fixing element 26 to be inserted into the cage structure 18 or removed therefrom, and an undeformed condition, in which they engage in the respective scats 40 of the cage structure 18 to ensure that the fixing element 26 is held in the cage structure 18, and that therefore the fixing element 26, along with the bail head 20 of the push-rod 12, is connected to the control pedal 10. [0027] The first and second pawls 32 and 36, as well as the tabs 30, are also advantageously formed in one piece with the upper frame 28, for example by plastic injection moulding process. [0028] In order to ensure that the first and second pawls 32 and 36 are held in the afore- mentioned undeformed condition, in which they engage in the respective scats 40 of the cage structure 18, when the fixing element 26 is mounted inside the cage structure 18, the connection device 14 further comprises a pair of locking inserts 42 (preferably made of plastic) arranged to cooperate with the first and second pawls 32 and 36. [0029] With reference in particular to Figures 3, 5 and 6, the locking inserts 42 are carried by the fixing element 26 on opposite sides of the tabs 30, that is to say, on opposite sides of the ball head 22 when the latter is received in the ball socket 22 and retained by the tabs 30. The locking inserts 42 are slidable relative to the fixing element 26, in a direction parallel to the insertion direction x, along the other pair of opposite and parallel sides (indicated at 28b) of the upper frame 28. [0030] Preferably, in order to reduce the number of parts that have to be moved by the operator during assembly of the connection device, the locking inserts 42 are made in one piece with the fixing element 26, and are each connected to the fixing element 26 by a respective thin connecting portion defining an easily breakable point, so that they can be easily detached from the fixing element 26 to be moved relative to that element in a direction parallel to the insertion direction x. Alternatively, the locking inserts 42 may be made as separate pieces with respect to the fixing element 26. [0031] In order to guide the sliding movement of the locking inserts 42 along the fixing element 26, preferably each of the sides 28a of the upper frame 28 of the fixing element 26 has a pair of guide grooves 44 which extend parallel to the insertion direction x and in each of which a respective guide edge 46 of a respective locking insert 42 slidably engages. [0032] Each locking insert 42 is movable relative to the fixing element 26 in the insertion direction x, starting from a non-working position (shown in Figure 5), in which the guide edges 46 of the locking insert 42 start to engage in the respective guide grooves 44 of the fixing element 26, but the locking insert 42 is still almost completely outside the fixing element 26, up to a working position (shown in Figures 2 and 6), in which the locking insert 42 is completely received inside the fixing element 26 and rests with its pair of opposite and parallel sides 42a against a respective one of the first pawls 32 and against a respective one of the second pawls 36, thereby preventing these pawls from elastically deforming to such an extent as to disengage from the respective scats 40 of the cage structure 18. Therefore, as long as the locking inserts 42 are in the aforementioned working position, in which they are completely received inside the fixing element 26, the fixing element 26 cannot be disassembled from the cage structure 18, and hence the ball head 20 of the push-rod 12, which is retained in the fixing element 6 26 by the tabs 30, cannot be disconnected from the control pedal 10 unless a special tool is used to force the tabs 30 away from each other. [0033] Preferably, in order to ensure that the locking inserts 42 are held in the afore- mentioned working position, each locking insert 42 is provided with a respective elastically deformable detent tooth 48. Each detent tooth 48 is suitably shaped to allow, by virtue of its elastic deformability, the respective locking insert 42 to be inserted into the fixing element 26, but to prevent (obviously, unless it is deformed by an operator by means of a special tool), by resting in abutment against a respective side 28b of the upper frame 28, the respective locking insert 42 from being pulled out of the fixing element 26. [0034] As will be apparent from the above description, the connection device of the present invention allows to quickly, easily and securely connect a push-rod to a control member, such as a control pedal of a vehicle. The locking inserts 42 may advantageously be mounted in advance on the fixing element 26 (as shown in Figure 5), so as to be handled as a single piece with the fixing element 26. In order to retain the fixing element 26 in the cage structure 18, and hence to securely connect the ball head 20 of the push-rod 12 to the control member 10, the operator just needs to push the two locking inserts 42 into the fixing element 26 until they reach the aforementioned working position. In that position, the locking inserts 42 prevent disengagement of the first and second pawls 32 and 36 from the respective scats 40 of the cage structure 18, and therefore the fixing element 26 is firmly and securely retained in the cage structure 18. [0035] Naturally, the principle of the invention remaining unchanged, the embodiments and the constructional details may vary widely from those described and illustrated purely by way of non-limiting example, without thereby departing from the scope of the invention as defined in the appended claims. 7 [Revendication 11