Device and method for removing a locking pin of a tensioner for a belt transmission

Abstract

A device for removing a locking pin (2) of a tensioner (3), the device comprising: a body (11) provided with a key (34) coupleable to a loading element (35) integral with an arm (5) of the tensioner (3); a rod (12) rigidly coupled to the body (11); a sliding element (13) coupled in a prismatic shape to the main body (11) and movable relative to the main body (11) along a first axis (C) parallel to the axis of the locking pin (2) when the key (34) is coupled to the loading element (35); at least one magnet (71) carried by a sliding element (13) and configured to interact with a locking pin (2) of the tensioner (3), the sliding element (13) being movable between a rearward rest position and a forward position coupled with the locking pin (2); and elastic means (91) which exert on the sliding element (13) an elastic force parallel to the direction of the relative movement between the main body (11) and the sliding element (13) in order to return the sliding element (13) from the forward position to the rest position.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This patent application claims the priority of Italian Patent Application No. 102022000011642 filed on June 1, 2022, the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] The invention relates to a device and a method for removing a locking pin of a tensioner for a belt drive. Background Art

[0004] As is known, a tensioner for a belt of a transmission comprises a base, an arm hinged to the base, a pulley carried by the arm and rotatable relative to the arm, and a spring exerting a torque on the arm configured to maintain the pulley in contact with the belt. Typically, the tensioner also comprises a locking pin configured to lock the arm in a mounted position relative to the base.

[0005] Conveniently, the tensioner is provided in the installed position, i.e. with the locking pin inserted so as to lock the arm relative to the base. This facilitates the installation of the belt and the tensioner, in particular the positioning and fixing of the base, but makes it necessary to remove the locking pin in order to operate the tensioner.

[0006] Since the locking pin is subject to the cutting force exerted by the spring on the arm, its removal is only possible under balanced conditions, in which the operator manually balances this force by acting with a key on a loading element integral to the arm. This operation is performed with only one hand, since the other hand is manually extracting the locking pin. The manual effort required is therefore very high.

[0007] The object of the present invention is to provide a device capable of overcoming the above-mentioned problems. Summary of the invention

[0008] The above object is achieved by the device according to claim 1.

[0009] The invention also relates to a method as claimed in claim 10 . BRIEF DESCRIPTION OF THE DRAWINGS

[0010] For a better understanding of the present invention, preferred embodiments are described below by way of non-limiting examples and with reference to the accompanying drawings, in which:

[0011] - Figure 1 is a front view of the device according to the present invention;

[0012] - Figure 2 yes Figure 1 A rear view of the device;

[0013] - Figure 3 yes Figure 1 A side view of the device;

[0014] - Figure 4 is along Figure 1 A cross-sectional view taken along line IV-IV of ;

[0015] - Figure 5 is along Figure 3 A cross-sectional view of line VV;

[0016] - Figure 6 is along Figure 1 A partial cross-sectional view taken along line VI-VI of FIG.

[0017] - Figure 7 is Figure 3 The opposite side of Figure 1 A partial side elevation view of the device in different operating positions on an enlarged scale; and

[0018] - Figure 8 yes Figure 1 A partial exploded view of the device. DETAILED DESCRIPTION

[0019] refer to Figure 1 , denoted by 1 is a device according to the invention for removing a locking pin 2 of a tensioner 3 .

[0020] In particular, the tensioner 3 is of a known type and comprises a base 4, an arm 5 hinged to the base 4 and a pulley 6 carried by the arm 5 and rotatable relative thereto. The tensioner 3 also comprises a spring (not shown) which exerts a torque on the arm 5 configured to cause the arm 5 to rotate relative to the base 4 in a direction so as to maintain the pulley 6 in contact with a belt (not shown) of a transmission (e.g. an accessory transmission of an internal combustion engine) in use. The locking pin 2 is configured to lock the arm 5 in the mounted position relative to the base 4 and must be removed in order to operate the tensioner 3 and to enable the arm 5 to rotate under the action of the spring.

[0021] The device 1 comprises a body 11 , a rod 12 rigidly coupled to the body 11 , and a sliding element 13 prismatically coupled to the body 11 .

[0022] The body 11 comprises a coupling portion 21 shaped substantially as a cylinder having an axis A, and a guide portion 22 extending along a lateral outer surface 23 of the coupling portion 21 and configured to guide the sliding element 13 .

[0023] The connecting portion 21 of the main body 11 ( Figure 2) is configured to be coupled to the tensioner 3. In particular, the coupling portion 21 has a substantially cylindrical base 31 defined by a substantially circular portion 32 with axis A and a circumferential edge 33 extending axially from the lateral outer surface 23. The coupling portion 21 is provided with a key 34 with axis A, arranged in the portion 32, capable of being coupled to a loading element 35 integral with the arm 5 of the tensioner 3.

[0024] In particular, the loading element 35 ( Figure 4 ) is the prismatic end of the pin of the pulley 6 of the tensioner 3. Thus, the base 31 is configured to at least partially house the pulley 6, and the "female" type key 34 is configured to cooperate with the loading element 35 in a prismatic shape. Conveniently, the key 34 is interchangeable and can be selected based on the prismatic end of the pin in order to couple therewith.

[0025] The rod 12 comprises a shank 36 extending along an axis B orthogonal to the axis A and rigidly coupled to the coupling portion 21 .

[0026] Handle 36( Figure 4 and Figure 5 ) comprises a first end 41 which is free and constitutes the handle of the device 1 and a second end 42 which is inserted inside the body 11 and carries the key 34. Conveniently, the body 11 has a generally tubular connecting portion 43 which extends from the coupling portion 21 along the axis B and surrounds a section of the handle 36 close to the second end 42.

[0027] The guide portion 22 of the main body 11 ( Figure 8 ) is generally shaped as a prism with a trapezoidal base, which extends along an axis C parallel to the axis A and is connected to the coupling portion 21 along its own lateral face (corresponding to the larger base of the trapezoid). The guide portion 22 ( Figure 6 ) is hollow and has lateral walls 51 and a base wall 52 orthogonal to the axis C, which as a whole define a cavity 53 that is open on the side of the edge 33 of the coupling portion 21 and is configured to at least partially accommodate the locking pin 2.

[0028] In particular, the locking pin 2 is made of ferromagnetic material, generally L-shaped, with a long section 54 defining the axis of the locking pin 2 and a short section 55 orthogonal thereto. The long section 54 is configured to lock the arm 5 in the mounted position relative to the base 4 of the tensioner 3, engaging with corresponding holes (not shown) obtained in radial appendages 56 of the arm 5 and in the base 4, respectively, the short section 55 being arranged on the opposite side relative to the base 4 of the tensioner 3.

[0029] The cavity 53 of the guide portion 22 is dimensioned to allow entry of the locking pin 2 along its own axis, which is arranged parallel to the axis C, so that the short section 55 is completely accommodated in the cavity 53 and the long section 54 is at least partially accommodated in the cavity 53 .

[0030] The sliding element 13 is shaped to at least partially surround the guide portion 22. In particular, the sliding element 13 is substantially a prism with a trapezoidal base, which is shaped similarly to the guide portion 22 and has a cavity sized to accommodate the guide portion 22. In particular, the sliding element 13 includes a lateral wall 61 and a base portion 62, the lateral wall 61 being shaped to surround and slide along the lateral wall 51 of the guide portion 22, and the base portion 62 being arranged on the opposite side relative to the edge 33 and extending from the lateral wall 61 toward the coupling portion 21.

[0031] Preferably, the axial length of the lateral wall 61 is substantially equal to the axial length of the coupling portion 21 .

[0032] The lateral wall 61 of the sliding element 13 has corresponding axial projections along its lateral edge adjacent to the body 11, which can slide in corresponding grooves 63 present in the guide portion 22. Therefore, the sliding element 13 behaves like a kind of slider sliding on the guide portion 22.

[0033] The sliding element 13 can be in the rearward rest position ( Figure 3 , Figure 4 and Figure 6 ) and forward connection position ( Figure 7 ) where the sliding element interacts with the locking pin 2.

[0034] Device 1( Figure 6 ) also comprises two magnets 71 which are carried by the sliding element 13 and are configured to interact with the locking pin 2 of the tensioner 3 .

[0035] In particular, the sliding element 13 internally comprises a cylindrical central element 81 having an axis C and two cylindrical lateral elements 82 having axes parallel to the axis C, the cylindrical lateral elements 82 being equidistant from the cylindrical central element 81 and arranged along a plane containing the cylindrical central element 81 .

[0036] The cylindrical lateral element 82 has a respective first end housed in a plate 83 which is arranged in contact with the base portion 62 and is fixed to the base portion 62 by means of a screw 84 which passes through the base portion 62 and the plate 83. The second end of the cylindrical lateral element 82 is housed in a sliding manner in a respective hole 85 of the base wall 52 of the guide portion 22. Between the plate 83 and the base wall 52 of the guide portion 22, a respective compression spring 91 which is pre-stressed is mounted coaxially with the cylindrical lateral element 82. The spring 91 thus exerts an elastic force on the sliding element 13 which is configured to return the sliding element 13 from the forward position to the rest position.

[0037] The cylindrical central element 81 has a first end fixed to a plate 83 by means of screws 92, has a greater length relative to the cylindrical lateral elements 82 and can slide axially through a through hole 93 of the guide portion 22 with axis C. The second end of the cylindrical central element 81 is fixed by means of screws 94 to a support block 95 housed in a sliding manner in the cavity 53 of the guide portion 22. The support block 95 carries a magnet 71 fixed to the support block 95 by means of screws 96 and arranged on the opposite side relative to the axis C so as to interact magnetically with the short section 55 of the locking pin 2.

[0038] In use, the device 1 allows the locking pin 2 of the tensioner 3 to be removed.

[0039] In particular, the method of removing the locking pin 2 of the tensioner 3 by means of the device 1 comprises several steps, which will be described in detail below starting from the configuration in which the tensioner 3 is in the installed position, the locking pin 2 locks the arm 5 relative to the base 4 and the belt is installed.

[0040] First, the device 1 is coupled to the tensioner 3 so that the key 34 engages the loading element 35 .

[0041] Specifically, the key 34 is prismatically coupled to the prismatic end of the pin of the pulley 6 of the tensioner 3, so that the axis A coincides with the axis of the pin. Thus, the base 31 of the coupling part 21 at least partially accommodates the pulley 6 of the tensioner 3, and the cavity 53 of the guide part 22 at least partially accommodates the locking pin 2, in particular its short section 55.

[0042] Subsequently, the sliding element 13 is displaced from the rearward rest position into a forward position coupled with the locking pin 2 against the action of the spring 91 , in order to magnetically couple the magnet 71 to the locking pin 2 .

[0043] Since the sliding element 13 is movable relative to the body 11 along an axis C parallel to the axis of the locking pin 2 when the key 34 is coupled to the loading element 35 , the magnet 71 carried by the sliding element 13 comes into contact with the short section 55 of the locking pin 2 .

[0044] When the sliding element 13 is in the forward coupling position, the spring 91 exerts a restoring force that returns it to the rearward rest position, thereby removing the locking pin 2 from the tensioner 3. However, the long section 54 of the locking pin 2 is subjected to a cutting force caused by the spring of the tensioner 3, which exerts a torque on the arm 5, which is configured to cause the arm 5 to rotate in the first rotational direction relative to the base 4. Therefore, the locking pin 2 remains in the tensioner 3 and the sliding element 13 remains in the forward coupling position.

[0045] Subsequently, a torque opposite to the first rotational direction is applied to the rod 12 in order to balance the torque exerted by the spring of the tensioner 3 on the arm 5 and thereby eliminate the cutting force acting on the long section 54 of the locking pin 2, thereby releasing the locking pin 2. The locking pin 2 is thus automatically removed from the base 4 and can also be removed from the arm 5, since the sliding element 13 returns to the rearward rest position under the restoring action of the spring 91.

[0046] The guide device 1 can then be rotated under the action of the spring of the tensioner 3 to a position in which the pulley 6 cooperates with the belt, and the force exerted by the contact between the belt and the pulley 6 balances the torque exerted on the arm 5 by the spring of the tensioner 3 .

[0047] At this point, the device 1 can be removed from the tensioner 3 by disengaging the key 34 from the loading element 35, since the resultant of the cutting forces on the loading element 35 of the tensioner 3 is zero. Therefore, the key 34 can be easily disengaged from the loading element 35. Due to the magnetic interaction between the locking pin 2 and the magnet 71, the locking pin 2 remains magnetically coupled to the device 1.

[0048] Finally, the locking pin 2 can be manually pulled out of the device 1 , thereby disengaging it from the magnet 71 .

[0049] By examining the characteristics of the device 1, the advantages of the present invention are apparent.

[0050] In particular, device 1 allows to remove locking pin 2 in a simple and rapid manner, thus reducing manual operations. In fact, since the extraction of the pin is carried out automatically by spring 91, the operator has both hands free to apply on rod 12 a torque sufficient to balance the torque of the spring of tensioner 3.

[0051] Since the key 34 is interchangeable, the device 1 can be used on different tensioners simply by selecting the key 34 corresponding to the loading element 35 of the tensioner 3 .

[0052] Finally, it is obvious that modifications and variations may be made to the device 1 without departing from the scope of protection defined by the claims.

[0053] For example, the structure of the body 11, the rod 12 and the sliding element 13 may be different from what is described.

[0054] If the loading element 35 of the tensioner 3 is a "female" type key, the key 34 may be a "male" type, rather than a "female" type.

Claims

1. A device for removing a locking pin (2) of a tensioner (3), the device comprising: A body (11) provided with a key (34) capable of being coupled to a loading element (35) integral with an arm (5) of the tensioner (3); a rod (12) rigidly coupled to the body (11); a sliding element (13) coupled to the body (11) in a prismatic shape and capable of being moved relative to the body (11) along a first axis (C) parallel to the axis of the locking pin (2) when the key (34) is coupled to the loading element (35); at least one magnet (71) , the at least one magnet (71) is carried by the sliding element (13) and is configured to interact with the locking pin (2) of the tensioner (3), the sliding element (13) being movable between a rearward rest position and a forward position coupled to the locking pin (2); and an elastic device (91) exerting an elastic force on the sliding element (13) parallel to the direction of relative movement between the body (11) and the sliding element (13) so as to return the sliding element (13) from the forward position to the rest position.

2. The device according to claim 1, wherein: The body (11) includes a coupling portion (21) provided with the key (34) and a guide portion (22) configured to guide the sliding element (13).

3. The device as claimed in claim 2, wherein: The coupling portion (21) has a base (31) configured to at least partially accommodate a pulley (6) of the tensioner (3), the key (34) being accommodated in the base (31) and configured to cooperate with a prismatic end of a pin of the pulley (6), the prismatic end defining the loading element (35).

4. The device according to claim 2 or 3, wherein: The guide portion (22) has a cavity (53) configured to at least partially accommodate the locking pin (2).

5. The device according to any one of claims 2 to 4, wherein: The guide portion (22) extends along an outer surface (23) of the coupling portion (21), and the sliding element (13) is shaped to at least partially surround the guide portion (22).

6. A device as claimed in any one of the preceding claims, wherein: The rod (12) includes a handle (36) orthogonal to the first axis (C).

7. The device according to any one of claims 2 to 6, wherein: The elastic means (91) is operably interposed between the guide portion (22) and the sliding element (13).

8. The device according to claim 7, wherein: The elastic means (91) comprises at least one compression spring (91) having an axis parallel to the first axis (C), and wherein the at least one compression spring (91) has a maximum extension in the forward position of the sliding element (13) and a minimum extension in the rearward position of the sliding element (13).

9. A device as claimed in any one of the preceding claims, wherein: The keys (34) are interchangeable.

10. A method for removing a locking pin (2) of a tensioner (3) by means of a device (1) as claimed in any one of the preceding claims, the tensioner (3) comprising: a base (4); an arm (5) hinged to the base (4); A spring, the spring exerting a torque on the arm (5), the torque being configured to cause the arm (5) to rotate relative to the base (4) in a first rotational direction; a locking pin (2), the locking pin (2) being configured to lock the arm (5) in a mounted position relative to the base (4); a pulley (6), the pulley (6) being carried by the arm (5) and being rotatable relative to the arm (5) about a second axis; and a loading element (35), the loading element (35) being integral with the arm (5) of the tensioner (3), the pulley (6) being configured to cooperate with a belt of a transmission, the method comprising the following steps: - coupling the device (1) to the tensioner (3) such that the key (34) engages the loading element (35); - displacing the sliding element (13) from the rearward rest position to the forward position coupled to the locking pin (2) against the action of the elastic means (91) so as to magnetically couple the at least one magnet (71) to the locking pin (2); as well as - applying a torque on the rod (12) opposite to the first rotational direction in order to balance the torque applied by the spring of the tensioner (3) on the arm (5), thereby releasing the locking pin (2) at least from the base (4) by displacement of the sliding element (13) via the elastic means (91) from the coupled forward position to the rearward rest position.

11. The method of claim 10, further comprising the steps of: - under the action of the spring of the tensioner (3), the device (1) is guided to rotate to a position in which the pulley (6) cooperates with the belt and the force exerted by the contact between the belt and the pulley (6) balances the torque exerted on the arm (5) by the spring of the tensioner (3); - removing the device (1) from the tensioner (3) by disengaging the key (34) from the loading element (35); and - Removing the locking pin (2) from the device (1).

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