A DEVICE FOR THE DISMANTLING AND REASSEMBLY OF VEHICLE-SUSPENSION SPRING/SHOCK-ABSORBER UNITS

Abstract: The device comprises: a fixed support frame (10) with which first engagement means for engaging the upper end of the spring (B) of the unit (A) are associated, the first engagement means being able to act on portions of the upper end disposed on opposite sides of a vertical plane extending through the longitudinal axis of the spring (B) as a result of a synchronous movement in a plane transverse the longitudinal axis of the spring (B), an actuator (12) mounted on the lower portion of the frame (10), and a movable frame (14) which can move vertically along the fixed frame (10) as a result of the operation of the actuator (12) and with which second engagement means for engaging the lower end of the spring (B) of the unit (A) are associated, the second engagement means being able to act on portions of the lower end disposed on opposite sides of a vertical plane extending through the longitudinal axis of the spring (B) as a result of a synchronous movement in a plane transverse that axis.

Description: A device for the dismantling and reassembly of vehicle- suspension spring/shock-absorber units The present invention relates to a device for the dismantling and reassembly of vehicle-suspension spring/shock-absorber units, in particular, those commonly known as McPherson struts . These devices have the function of neutralizing the resilient load transmitted by the spring to the remaining components of the unit which can thus be dismantled in safe conditions by an operator. The operator can then perform the necessary repair operations, for example, the replacement of the shock-absorber, and then reassemble the unit . The object of the present invention is to provide a device which permits the dismantling and reassembly of spring/shock-absorber units of various sizes and geometrical arrangements, in particular even those having springs which are conical or have their axes offset relative to the axis of the shock-absorber rod, ensuring a high degree of safety for the operator. According to the invention, this object is achieved by means of a device having the specific characteristics recited in the appended claims . Since the engagement means of the device of the invention act solely on the spring of the spring/shock-absorber unit, they enable the device, in particular, to be fully adaptable to units with springs which have various diameters and/or a conical structure and/or which are offset relative to the shock-absorber rod. Further advantages and characteristics of the present invention will become clear from the following detailed description, given with reference to the appended drawings, provided by way of non-limiting example, in which: Figure 1 is a perspective view of a device of the invention, Figure 2 is an exploded view of the main components of the device of Figure 1, Figure 3 is a perspective view showing a detail of the device of Figure 1, on an enlarged scale, and Figure 4 is a view of the device of the previous drawings operating on a spring/shock-absorber unit. A device for the dismantling and reassembly of a vehicle- suspension spring/shock-absorber unit A (visible in Figure 4) comprises (Figures 1 and 2): a fixed support frame 10, an actuator 12 mounted on the lower portion of the fixed frame, and a movable frame 14 which can move vertically along the fixed frame 10 as a result of the operation of the actuator 12. The fixed frame 10 includes two vertical profiled elements 18 fixed to a base 20 and connected at their upper ends by a cross-member 22 on the top of which a compartment 24 for holding objects is fixed. First engagement means for engaging the upper end of the spring B of the unit A are associated with the fixed frame 10 and comprise a first arm and a second arm 26a, 26b each having one end 28 articulated to the cross-member 22 of the frame 10 and an opposite, distal end 30 supporting a coupling member. Each of the coupling members comprises a rod 32 which can be housed in a seat 34 of square cross-section in the distal end 30 of the respective arm 26a, 26b. A pin 36 mounted rotatably in the rod 32 carries, at its distal end, a bracket 38 which has tabs 40 for restraining the spring B and from which project two hooks 42 for the coupling member of the arm 26a, and only one hook 42 for the coupling member of the arm 26b, respectively. Each coupling member also has means for adjusting the height at which it is positioned relative to the fixed frame 10. These adjustment means comprise a plurality of holes 44 which are offset vertically on the distal ends 30 of the arms 26a, 26b and communicate with the seat 34, and a key 46 which can be inserted in one of the holes 44 , according to choice . Respective rods 48a, 48b project from the ends 28 of the first and second arms 26a 26b which are articulated to the frame 10 (Figure 3) , the distal ends 50 of the rods 48a, 48b being coupled in a manner such that a rotary movement imparted to one of the arms 26a, 26b about the end 28 brings about a rotary movement of equal amplitude of the other arm 26b, 26a about its end 28. In greater detail, the two arms 26a, 26b are coupled by virtue of the fact that an eye 52 is fixed to the end 50 of one of the rods 48a and the end 50 of the other rod 48b is restrained in the eye. Second engagement means for engaging the lower end of the spring B are associated with the movable frame 14 (Figures 1 and 2) and comprise a third arm 26c and a fourth arm 26d each having one end 28 articulated to the movable frame 14 and an opposite, distal end 30 supporting a coupling member. The coupling member associated with the fourth arm 26d comprises a rod 32 which can be housed in a square-sectioned seat 34 formed in the distal end 30 of the arm 26d. A pin 36 mounted rotatably in the rod 32 carries, at its distal end, a bracket 38 which has tabs 40 for restraining the spring B and from which a hook 42 projects. The coupling member associated with the fourth arm 26d has means for adjusting the height at which it is positioned relative to the frame 14. These adjustment means comprise a threaded seat formed in the member and an adjustment screw 54 which can be screwed into the seat . In embodiments of the invention which are not shown, adjustment means of this type could be used for adjusting the height of the coupling members associated with the arms 26a, 26b and, conversely, the adjustment means described above for the adjustment of the height of the latter coupling members could be used for the adjustment of the height of the coupling member associated with the arm 26d. The coupling member associated with the third arm 26c comprises a threaded rod 56 which can be screwed into a threaded seat 58 in the distal end 30 of the arm 26c and carries, at its distal end, a bracket 38 which has tabs 40 for restraining the spring B and from which two hooks 42 project. As described above with reference to the first and second arms 26a, 26b and illustrated in Figure 3, respective rods project from the ends 28 of the third and fourth arms 26c, 26d which are articulated to the frame 14, the distal ends of the rods being coupled in a manner such that a rotary movement imparted to one of the arms brings about a rotary movement of equal amplitude of the other arm. The movable frame 14 comprises (Figures 1 and 2) two vertical bars 60 connected at their upper and lower ends by respective cross-members 62 and has spaced-apart rollers 64 for enabling it to slide linearly along the fixed frame 10. A plate 66 for supporting the lower end of the spring/shock- absorber unit A is mounted so as to be slidable vertically on the frame 14. The plate 66 is mounted, with the interposition of resilient means such as a helical spring 68, on a flange 70 of a support member to an opposed flange 72 of which is fixed a sleeve 74 which can slide about a rod 76 fixed to the movable frame 14. The plate 66 can be fixed at a predetermined level relative to the movable frame 14 in a known manner, not shown in the drawings, for example, by means of a screw which extends through a radial hole in the sleeve 74 and is intended to abut the rod 76. The actuator 12 is a pneumatic unit of the cylinder-piston type, the piston of which can act on a respective abutment surface of the upper cross-member 62 of the movable frame 14. The actuator 12 can be operated by means of a pedal 78 provided with protection 80 for the operator's foot. The actuator 12 advantageously incorporates a safety valve which can close automatically in the event of failure of the air supply, whilst permitting decompression of the spring B. The device also has a protection member 82 for the region which is intended to house the spring/shock-absorber unit A. The member 82 is in the form of a generally C-shaped cage articulated to the fixed frame 10 at distal ends 84 of arms 86 and movable between an operative configuration and an inoperative configuration to which it is pivoted through approximately 90° from the former configuration (see arrow 87 in Figure 1) . When the protection member 82 is in the inoperative configuration, it advantageously deactivates the actuator 12 automatically. When the device just described is in operation, the spring/shock-absorber unit A to be dismantled is placed on top of the movable frame 14 , the lower end of the spring B being engaged first of all (Figure 4) . This engagement takes place by pivoting of the arms 26c, 26d in a plane transverse the axis of the spring B and in a synchronous and symmetrical manner by virtue of the engagement achieved by the rods 48a, 48b (see arrow 88 in Figure 1) , thus bringing the respective coupling members into contact with portions of the spring B disposed on opposite sides of a vertical plane extending through its longitudinal axis, in particular, substantially diametrally opposed portions. These portions are held between the hooks 42 and the respective portions of the brackets 38 having restraining tabs 40. The engagement of the hooks 42 on the portions of the spring B facing them is further favoured by the fact that the brackets 38 carrying the hooks 42 can be rotated about a vertical axis (see arrows 90 in Figure 1) . The height at which the coupling member associated with the arm 26d is positioned can undergo a specific adjustment by the operation of the screw 54 (see arrow 92 in Figure 1) since the portion of spring B engaged thereby will typically be disposed at a different height from that engaged by the engagement member associated with the arm 26c, owing to the helical shape of the coils of the spring B . It is therefore clear that the reference to "substantially diametrally opposed portions of the spring B" in the previous paragraph, as well as in other passages of the present description, should be understood in a broad sense as referring to the projections of these spring portions in a horizontal reference plane . The movable frame 14 is then urged upwards by the actuator 12 (see arrow 94 in Figure 1) , operated by the pedal 78, until the upper end of the spring B is engaged by the fixed frame 10. This engagement takes place by pivoting of the arms 26a, 26b in a plane transverse the axis of the spring B and in a synchronous and symmetrical manner by virtue of the engagement achieved by the rods 48a, 48b (see arrows 96 in Figure 1) , thus bringing the respective coupling members into contact with portions of the spring B disposed on opposite sides of a vertical plane extending through its longitudinal axis, in particular, substantially diametrally opposed portions. These portions are held between the hooks 42 and the respective portions of the brackets 38 provided with restraining tabs 40, advantage being taken, in this case also, of the fact that the brackets 38 carrying the hooks 42 can be rotated about a vertical axis (see arrows 98 in Figure 1) in order to achieve a more secure engagement. The height at which the engagement members associated with the arms 26a, 26b are positioned may undergo a specific adjustment (see arrows 100 in Figure 1) by the insertion of the respective keys 46 in suitable holes 44, since the portions of the spring B engaged thereby will typically be at different heights . Altogether, the capability for simultaneous radial movement of the two pairs of arms 26a, 26b; 26c, 26d of the lower and upper engagement means, respectively, thus permits self- centring clamping of the spring B, irrespective of its diameter and of any taper and/or lack of alignment with the shock-absorber C. The secure and firm clamping of the spring B is also favoured by the restraining tabs 40 and by the fact that the heights at which the coupling members associated with the arms 26a, 26b and 26d are positioned can be adjusted, whereas that of the member associated with the arm 26c remains fixed, acting as a reference. Once the spring B is firmly fixed at both of its ends, the actuator 12 can be operated again so as to bring about a further upward movement of the movable frame 14 and a consequent gradual compression of the spring B until the resilient load transmitted by the spring to the remaining components of the unit A is cancelled out. The operator can thus remove the nut D clamping the plate E without any risk and, by virtue of the particular structure of the device, the nut is easily accessible, even with professional unscrewing tools . When the nut D has been unscrewed, the shock-absorber C is released from the other components of the unit A. It is prevented from falling by the fact that its base bears on the plate 66 which has previously been positioned adjacent the top of the movable frame 14 , the upward movements of which it has followed. If the plate 66 is now moved downwards (see arrow 102 in Figure 1) along the rod 76 fixed to the frame 14 which, at this stage, remains stationary, the shock-absorber C is freely accessible. It should be noted that, even if the operator were to forget to position the plate 66 initially adjacent the top of the movable frame 14 so as to arrange it directly beneath the base of the shock-absorber C, its fall would be deadened by the helical spring 68 disposed beneath the plate 66. In any case, once the shock-absorber C bears on the plate 66 and the plate is lowered, the shock-absorber C can easily and quickly be removed and replaced by a spare one . The operator can then reassemble the unit A by repeating the steps just described in reverse. At this stage, the plate 66 performs the task of supporting the new shock-absorber in the correct position, leaving the operator's hands completely free to position the various accessories beneath the nut D. Naturally, the principle of the invention remaining the same, the details of construction and forms of embodiment may vary widely with respect to those described purely by way of example, without thereby departing from its scope.

Claims: CLAIMS 1. A device for the dismantling and reassembly of a vehicle- suspension spring/shock-absorber unit (A) , comprising: - a fixed support frame (10) with which first engagement means for engaging the upper end of the spring (B) of the unit (A) are associated, the first engagement means being able to act on portions of the upper end disposed on opposite sides of a vertical plane extending through the longitudinal axis of the spring (B) as a result of a synchronous movement in a plane transverse the longitudinal axis of the spring (B) , - an actuator (12) mounted on the lower portion of the frame (10) , and - a movable frame (14) which can move vertically along the fixed frame (10) as a result of the operation of the actuator (12) and with which second engagement means for engaging the lower end of the spring (B) of the unit (A) are associated, the second engagement means being able to act on portions of the lower end disposed on opposite sides of a vertical plane extending through the longitudinal axis of the spring (B) as a result of a synchronous movement in a plane transverse the longitudinal axis of the spring (B) . 2. A device according to Claim 1, in which the first and second engagement means can act on respective pairs of substantially diametrally opposed portions of the upper and lower ends of the spring (B) . 3. A device according to Claim 1 or Claim 2 , in which the first engagement means comprise a first arm and a second arm (26a, 26b) each having one end (28) articulated to the frame (10) and an opposite, distal end (30) supporting a coupling member . . A device according to Claim 3 , in which at least one component of the coupling member is mounted so as to be rotatable about a vertical axis . 5. A device according to Claim 4 , in which the coupling member comprises a rod (32) which can be housed in a seat (34) in the distal end (30) and in which a pin (36) is mounted rotatably, the pin (36) carrying, at its distal end, a bracket (38) from which at least one hook (42) projects. 6. A device according to any one of preceding Claims 3 to 5 , in which the coupling member has means for adjusting the height at which it is positioned relative to the fixed frame (10) . 7. A device according to Claim 6, in which the adjustment means comprise a plurality of holes (44) offset vertically on the distal ends (30) of the arms (26a, 26b) and communicating with the seat (34) , and a key (46) which can be inserted in one of the holes (44), according to choice. 8. A device according to any one of preceding Claims 3 to 7 , in which respective rods (48a, 48b) project from the ends (28) of the first and second arms (26a, 26b) which are articulated to the frame (10) , the distal ends (50) of the rods (48a, 48b) being coupled in a manner such that a rotary movement of one of the arms (26a, 26b) about the end (28) brings about a rotary movement of equal amplitude of the other arm (26b, 26a) about the respective end (28) . 9. A device according to any one of the preceding claims, in which the second engagement means comprise a third arm and a fourth arm (26c, 26d) each having one end (28) articulated to the movable frame (14) and an opposite, distal end (30) supporting a coupling member. 10. A device according to Claim 9 , in which at least one component of the coupling member is mounted so as to be rotatable about a vertical axis. 11. A device according to Claim 10, in which the coupling member of the fourth arm (26d) comprises a rod (32) which can be housed in a seat (34) in the distal end (30) and in which a pin (36) is mounted rotatably, the pin (36) carrying, at its distal end, a bracket (38) from which at least one hook (42) projects. 12. A device according to any one of preceding Claims 9 to 11, in which the coupling member of the fourth arm (26d) has means for adjusting the height at which it is positioned relative to the frame (14) . 13. A device according to Claim 12, in which the adjustment means comprise a threaded seat in the coupling member of the fourth arm (26d) and an adjustment screw (54) which can be screwed into the threaded seat . 14. A device according to any one of the preceding claims, in which respective rods (48a, 48b) project from the ends of the third and fourth arms (26c, 26d) which are articulated to the movable frame (14) , the distal ends (50) of the rods (48a, 48b) being coupled in a manner such that a rotary movement of one of the arms (26c, 26d) about its end (28) brings about a rotary movement of equal amplitude of the other arm (26d, 26c) about the respective end (28) . 15. A device according to any one of the preceding claims, in which the movable frame (14) comprises two vertical bars (60) connected by respective cross-members (62) at their upper and lower ends and has rollers (64) for enabling it to slide along the fixed frame (10) . 16. A device according to any one of the preceding claims, in which a plate (66) for supporting the lower end of the shock-absorber (C) of the unit (A) is mounted so as to be slidable vertically on the movable frame (14) . 17. A device according to Claim 16, in which the plate (66) is mounted, with the interposition of resilient means (68) , on a flange (70) of a support member to an opposite flange (72) of which is fixed a sleeve (74) which can slide along a rod (76) fixed to the movable frame (14) . 18. A device according to any one of the preceding claims, in which the actuator (12) is a pneumatic unit of the cylinder-piston type. 19. A device according to any one of the preceding claims, having a protection member (82) for protecting the region intended to house the spring/shock-absorber unit (A) , the member (82) being movable between an operative configuration and an inoperative configuration in which it prevents the operation of the actuator (12) . 20. A device according to Claim 19, in which the member (82) is in the form of a generally C-shaped cage, articulated to the support frame (10) in the region of ends (84) of arms (86) of the cage.

Inventors: GAZZANO CARLO, GAZZANO, CARLO
Applicants: GAZZANO CARLO, SEMAD S R L UNIPERSONALE, GAZZANO, CARLO, SEMAD S.R.L. UNIPERSONALE
Application year: 2000
Main classification: B25B27
IPC codes: B25B27