EP1961531A1 - Tightening device with a retractable manoeuvring arm and apparatus including such a device - Google Patents

Abstract

The device has a connection device to connect a nut and an operating key that includes an arm (17) made of magnetic material. The connection device is arranged such that the key is tilted with respect to the nut around a tilting axis for placing the key in rest position. The key rotatably drives the nut around a screwing axis (X-X) in a locking/unlocking direction, or freely rotates relative to the nut around the screwing axis over an angular clearance range of 170 degrees in a direction opposite to the locking direction after immobilization of the nut in end of locking operation.

Description

The present invention relates to a clamping device with retractable operating arm. It also targets devices equipped with this clamping device, for example portable tools and, in particular portable chain saws.

It is common to use a screw or a nut screwed on a threaded rod to achieve a clamping force between two parts. A piece mounted using a screw-nut system has the advantage of being removable. Disassembly and subsequent reassembly, however, require the loosening of nuts or screws using an independent tool such as a wrench or a screwdriver, and then tightening with the same tool. However, we do not always have such a tool that can be lacking at the very moment when we need to loosen and / or tighten nuts or screws.

In addition, it frequently happens that a screwdriver or a key accidentally disconnects from the head of the screw or the nut being maneuvered. Therefore, the tightening and loosening of a nut or a screw sometimes require to know combine strength and skill.

A screw-nut device generally equips the portable chain saws to perform the clamping and immobilization, in the desirable position, of the guide bar, to allow adjustment of the tension of the latter or the establishment of a new chain.

In such an application, it is conceivable that the operator must always have, at hand, a dedicated tool to loosen or tighten the nut or the clamping screw, particularly during the use of the tool outside when It may be necessary to make adjustments to the tension of the chain of the saw.

To overcome this constraint, it has been proposed ( DE-29909645 U1 ) a device for clamping the chain guide of a chain saw by means of a screw-nut system in which the nut of that system is permanently secured to a operating key that can be folded against the tool housing, in the neutral position, when not in use. According to this device, a rotating ring is placed under the head of the nut and the key is fixed with a tiltability on this ring, about an axis perpendicular to the axis of the nut and offset from to the latter. On the other hand, the head of the nut is provided with two radial notches, while the key is provided with a tooth which, according to the tilting position of said key, can mesh with one of said notches to allow the rotating the nut in one direction or the other, or being free of said notches to allow free rotation of the wrench around the nut.

This device requires, prior to the rotational movement of the nut or placement of the key in the storage position, a clutch maneuver or disengagement required, as appropriate, which may not be immediately understood by users.

The aim of the invention is at least to propose a solution to the problems arising from the various constraints described above.

According to the invention, this object is achieved by means of a clamping device of the screw-nut type, comprising a clamping member adapted to be rotated and a drive key of this clamping member provided with a maneuvering arm. this key and the clamping member being united by a connecting device arranged so that the key can tilt relative to the clamping member about a tilting axis perpendicular to the screw axis of said clamping member , so as to allow its placement in the rest position substantially perpendicular to said screw axis, and can cause the clamping member to rotate about the screw axis in the direction of tightening or loosening, or to rotate freely relative to the clamping member, about said screw axis, over an angular range of travel of at least 170 °, after immobilization of said clamping member, at the end of clamping maneuver.

Thanks to the invention, the operation of the clamping device does not require the use of any external tool to tighten or loosen the clamping member (screw or nut) of said device. The key connected to the clamping member allows the drive in rotation of the latter, while being able to be placed in a determined rest position without modifying the tightening obtained, for example in a position folded against the housing of the apparatus so as not to hinder the use thereof . In addition, this maneuver is very simple and fast.

According to an advantageous embodiment, the rotary clamping member of the screw-nut system connected to the operating key, is constituted by the nut of said system.

Advantageously, the clamping member and the driving key of the connecting device are provided, respectively, with means coming into contact with each other, during the rotation of the key, on the one hand, in the the tightening direction of the clamping member when the key is at a first end of the range of angular deflection, and secondly in the direction of unscrewing of the clamping member when the key is at a second end of the range of angular deflection.

• une gorge annulaire ménagée dans la surface cylindrique externe du corps de l'organe de serrage rotatif et dans le fond de laquelle est logée une butée d'entraînement orientée parallèlement à l'axe de vissage dudit organe de serrage rotatif ;
• un chapeau rotatif tubulaire dans lequel est logé le corps dudit organe de serrage et comportant deux trous diamétralement opposés débouchant dans la gorge annulaire dudit organe de serrage, et
• un agencement de la tête de la clé d'entraînement selon lequel ladite tête est réalisée sous forme d'une fourchette à deux branches, les extrémités de ces branches étant recourbées ou formées en direction l'une de l'autre et engagées avec une aptitude de rotation dans les trous diamétralement opposés du chapeau rotatif, l'une au moins de ces extrémités recourbées étant dimensionnée pour s'étendre à travers ladite gorge et venir au contact de la butée d'entraînement de l'organe de serrage rotatif.

According to a preferred embodiment, the connection means between the drive key and the clamping member comprise:

• an annular groove formed in the outer cylindrical surface of the body of the rotary clamping member and in the bottom of which is housed a drive stop oriented parallel to the axis of screwing of said rotary clamping member;
• a rotatable tubular cap in which is housed the body of said clamping member and having two diametrically opposed holes opening into the annular groove of said clamping member, and
• an arrangement of the head of the driving key in which said head is in the form of a fork with two branches, the ends of these branches being bent or formed towards one another and engaged with an aptitude rotating in the diametrically opposite holes of the rotary cap, at least one of these curved ends being dimensioned to extend through said groove and come into contact with the driving abutment of the rotary clamping member.

According to another advantageous characteristic, the curved end of the second branch of the drive fork is dimensioned so as not to come into contact with the driving abutment of the clamping member, during the pivoting of the wrench around of the screw axis, relative to the clamping member.

Another advantageous feature of the clamping device may be that said connecting device provides an unmountable connection between the key and the clamping member.

Advantageously, the unmountable connection between the key and the clamping member is obtained by plastic deformation of said branches towards each other, so as to engage these branches in the holes of the cap.

Preferably, said connecting device provides a removable connection between the key and the clamping member, at least in the absence of clamping by this clamping member.

Preferably, the clamping member comprises a notch for lateral access to said annular groove, for the passage of one of said branches towards this annular groove, one of said holes of the hat having the shape of a slot having an open end for the passage of one of said branches.

Advantageously, the key comprises an operating arm provided with an extension with which this operating arm forms a telescopic handle of adjustable length, said extension being movable along the operating arm between a retracted position and a handle extension position telescopic.

Preferably, at least a portion of the operating arm is made of a magnetic material.

The invention also relates to an apparatus, characterized in that it comprises a clamping device as defined above.

According to an advantageous application, this apparatus is constituted by a chain saw which comprises an endless cutting chain and a chain guide. for this chain, and a locking device of this guide comprises said clamping device.

Advantageously, the apparatus comprises a storage area of the handle of the clamping device, in a predetermined angular position, around the screw axis.

Preferably, the apparatus comprises a sleeve retaining magnet in a stowed position at said storage area.

• la figure 1 est une vue en perspective d'une scie à chaîne conforme à l'invention ;
• la figure 2 est une vue éclatée d'un dispositif de serrage qui équipe la scie à chaîne de la figure 1 et qui est conforme à l'invention ;
• la figure 3 est une vue de dessus, avec arrachement, du dispositif de serrage de la figure 2 ;
• la figure 4 est une coupe selon la ligne IV-IV de la figure 3 ;
• la figure 5 est une coupe selon la ligne V-V de la figure 3 ;
• la figure 6 est une vue en perspective du dispositif de serrage représenté aux figures 2 à 5, montré sans sa rallonge formant poignée et illustrant une étape de l'assemblage des éléments dudit dispositif ;
• la figure 7 est une vue de dessus, avec arrachement, du dispositif de serrage des figures 2 à 5 et illustre une position de la clé considérée arbitrairement comme une étape finale d'un serrage à l'aide du dispositif de serrage des figures 2 à 5 ; le tracé en traits fins interrompus illustre une position de la clé lors du desserrage ;
• la figure 8 est une vue analogue à la figure 1 et illustre la même étape finale de serrage que la figure 7 ;
• la figure 9 est une vue analogue à la figure 7 et illustre le pivotement de la clé dans une position permettant son basculement autorisant son escamotage en position de repos ;
• la figure 10 est une perspective d'une scie à chaîne et montrant la clé dans une position de basculement corrrespondant à la figure 9 ;
• la figure 11 est une vue analogue à la figure 9 et montre le basculement de la clé en position de repos.
• la figure 12 est une vue en perspective de la scie à chaîne représentée aux figures 8 et 10 et montrant le bras de manoeuvre de la clé en position escamotée contre le carter de ladite scie à chaîne.

The invention will be better understood on reading the description which follows, given solely by way of example and with reference to the appended drawings, among which:

• the figure 1 is a perspective view of a chain saw according to the invention;
• the figure 2 is an exploded view of a clamping device that equips the chain saw of the figure 1 and which is in accordance with the invention;
• the figure 3 is a top view, broken away, of the clamping device of the figure 2 ;
• the figure 4 is a section along line IV-IV of the figure 3 ;
• the figure 5 is a section along line VV of the figure 3 ;
• the figure 6 is a perspective view of the clamping device shown in FIGS. Figures 2 to 5 , shown without its handle extension and illustrating a step of assembling the elements of said device;
• the figure 7 is a top view, broken away, of the clamping device of the Figures 2 to 5 and illustrates a position of the key considered arbitrarily as a final step of a tightening using the clamping device of the Figures 2 to 5 ; the broken fine line diagram illustrates a position of the key during loosening;
• the figure 8 is a view similar to the figure 1 and illustrates the same final tightening step as the figure 7 ;
• the figure 9 is a view similar to the figure 7 and illustrates the pivoting of the key in a position allowing it to tilt allowing its retraction in the rest position;
• the figure 10 is a perspective of a chainsaw and showing the key in a tilting position corresponding to the figure 9 ;
• the figure 11 is a view similar to the figure 9 and shows the tilting of the key to the rest position.
• the figure 12 is a perspective view of the chain saw shown in Figures 8 and 10 and showing the actuating arm of the key in the retracted position against the casing of said chain saw.

Referring to said drawings to describe an advantageous embodiment although not limiting of the clamping device according to the invention.

It is further emphasized that if a particularly advantageous application of the invention to the equipment of chain saws is described below, the claimed clamping device can also be applied to other tools or machines in which frequent adjustments of tightening must be carried out, in particular for devices that can be used outdoors.

On the figure 1 , there is shown a portable chain saw 1, which comprises a partially illustrated endless cutting chain 2 and a chain guide 3 holding and supporting this chain 2. A clamping device 4 generally designated by reference 4 to FIG. figure 1 clamps this bar 3 and a protective casing 5 between a jaw 5A and an assembly body 6.

On the figure 2 , is shown the clamping device 4, which comprises a nut 7 to be screwed onto a threaded rod 8, for example constituted by the threaded rod of a screw. This clamping device also comprises an operating key 11 and a connecting device generally designated by the reference 9 for joining the nut 7 to said operating key 11.

The nut 7 is pierced with a tapped hole 13 of axis X-X ', which is the axis of screwing of this nut 7, that is to say the axis around which the nut 7 turns when his face and his unscrewing. The nut 7 is provided with an annular and lateral groove 14, at its peripheral surface 15.

This peripheral surface 15 is cylindrical and has a circular section centered on the axis X-X '.

The nut 7 is provided with a pin 16 which passes through the lateral groove 14 from one side to the other.

The nut 7 is capped with a rotatable wrapping tubular cap 10 having two diametrically opposed holes 26a, 26b opening into the peripheral groove 14 of said nut.

The key 11 is flat and can advantageously be made in a steel blank. It comprises an arm 17 that extends a coupling head 18 to the nut 7. The head 18 has the shape of a fork having two branches 19 and 20 which curve and then move towards one another. One of these branches (branch 19) is longer than the other (branch 20) and its end portion forms a finger 21 abutting against the pin 16, on one side or the other of the ci, depending on the direction of rotation of the key.

The cap 10 comprises a cylindrical skirt 24, which closes an end wall 25. Two through holes 26a and 26b for the passage of the branches 19 and 20 are pierced in the skirt 24, opposite each other . One of the holes (hole 26a) can be circular and closed laterally.

According to one embodiment, the second hole (hole 26b) has the shape of a slot whose one end is in the axis of the hole 26a and whose other end, opens into the edge of the cap 10, to the back of it.

The end portions of the legs 19 and 20 are coaxial and engaged in the holes 26a and 26b so as to together form a discontinuous tilt shaft of the key 11 on the cap 10. The Y-axis tilting of this key 11 is perpendicular to the axis of screwing X-X ', said axes YY' and XX 'intersecting.

As can be seen from the Figures 3 to 5 , the cap 10 is rotatably mounted on the nut 7, so that its axis of rotation coincides with the screw axis X-X '. The branches 19 and 20 penetrate into the peripheral groove 14 and thus hold the key 11 and the cap 10 on the nut 7. In doing so, they have the advantage of filling a second function, their first function mentioned above being form a tilting mounting shaft.

In this respect, it should be noted that the branch 19, via its end 21, also fulfills a function of a rotary drive finger of the nut 7. The accumulation of functions performed by the branches 19 and 20 participates in an advantageous simplification of the clamping device 4 and promotes its compactness.

A notch 27 is formed laterally in the rear wall delimiting the groove 14 of the nut 7, this notch opening into said groove.

To assemble the elements of the connecting device, the nut 7 is placed in the cap 10. Next, the branch 19 is inserted in the hole 26a and in the groove 14 of the nut. Finally, the other branch is slid towards the bottom of the slot 26b, at the same time as this branch 20 is engaged in the peripheral groove 14, by passing it through the notch 27 ( figure 6 ). This method of assembly makes it possible to form a detachable connection between the key 11 and the nut 7.

According to another embodiment, the nut 7 may be devoid of the notch 27, while the hole 26b may have the same circular shape as the hole 26a. If this is the case, the branches 19 and 20 can be inserted into the holes 26a, the hole 26b and the groove 14 by plastically deforming them towards each other. In this case, an unmountable connection is made between the key and the clamping member.

According to an advantageous embodiment, the operating arm of the key has an adjustable length. In this case, this maneuvering arm is constituted two telescopically assembled elements, namely an arm 17 provided with the coupling head 18 on which is mounted, with a sliding ability, an extension 12.

This extension is a handle that can be performed in any suitable rigid material, for example plastic. The inner arm 17 is provided with a longitudinal slot 22, in which the rod of a bolt 23 passes. The slot 22 has two ends each of which its edge forms one of two abutments 22a and 22b for the bolt rod. 23. This bolt 23 and the stop 22a form complementary means for retaining the handle 12 on the arm 17.

Unlike branch 19, the branch 20 can cross the location of the pin 16 without clinging to it, as can be seen at figure 3 .

The key 11 can freely rotate with respect to the nut 7, over a range of angular displacement referenced α to the figure 7 . At one end of this range or deflection angle α, the finger 21 abuts against the pin 16 and thus couples the key 11 to the nut 7 in the direction of a screwing F ₁ of the nut 7, which is the case of the finger 21 in full line at the figure 7 . At the other end of the range or deflection angle α, the finger 21 also abuts against an opposite surface of the pin 16 and thus couples the key 11 to the nut 7, but in the direction of unscrewing F ₂ of this nut 7, which is the case of the finger 21 of the key 11 in phantom end to the figure 7 . The pin 16 therefore forms a double stop for the finger 21.

In the example shown, the range of angular deflection α extends over more than 340 °, which is advantageous. It can however be less extensive. Preferably, the angular range or angle of deflection α is, however, at least 170 °.

The handle 12 forms an extension in that it can slide longitudinally on the arm 17. In other words, the arm 17 and the handle 12 together form a telescopic handle 28, which is shown in the retracted position at the figure 4 and which is illustrated in extension to the figure 6 .

The housing 5 of the tool is provided laterally with a housing 29 for receiving the operating arm 17 of the key or the telescopic handle 28 of the latter in the retracted position. A retaining means keeps the operating arm 17 or the telescopic handle 28 of the key in the retracted position, against the housing 5 of the tool. For example, in the bottom of the housing 29, is disposed a magnet for retaining the actuating arm 17 or the handle 28 in the retracted rest position, this magnet being visible and designated by the reference 30 to Figures 8 and 10 .

To screw the nut 7, turn the key 11 in the direction F ₁ about the screw axis XX '( figure 7 ), so that its finger 21 comes into contact with the pin 16 and then drives the nut 7 via said pin 16.

On the figures 7 and 8 it is considered that the key 11 is in a position corresponding to the moment when the appropriate clamping force has been obtained. It is then necessary to retract the handle 28 in the housing 29, which is done without difficulty when the angular position of this housing 29 about the axis XX 'is in the range of angular deflection α, at the end of the tightening of the nut 7. Indeed, the key 11 can rotate freely, the clamping member 7 remaining locked in the immobilization position corresponding to the desired tightening.

In the example shown in figure 8 , the angular position of the housing 29 around the axis XX 'is outside the range of angular displacement α, after the tightening of the nut 7. The storage of the handle 28 then comprises a first step which consists of place this sleeve 28 in the position illustrated in figure 10 , by rotating it about the axis X-X ', after having retracted it. On this figure 10 , the retracted handle 28 is opposite the housing 29 relative to the axis X-X '. It is then tilted around the axis Y-Y ', in the direction of the arrow F ₃ , so as to embed it in the housing 29, after which the handle 28 is as illustrated in FIGS. figures 1 and 12 . In these figures, the handle 28 of the key is stored in the housing 29, where it is retained by the magnet 30 attracting a magnetic portion of the handle 28, namely its operating arm 17. Other means of retaining the operating arm of the key in the retracted position of rest can be provided.

When the nut 7 is tightened against the jaw 5A, the latter laterally closes the notch 27, as well as the hole 26b, so that the key 11 and the cap 10 can no longer be dissociated from the nut 7.

The invention is not limited to the embodiment described above. In particular, the movable clamping member in rotation may be constituted by a screw, in which case the connecting device 9 which has just been described is located at the head of this screw.

Claims (15)

Clamping device of the screw-nut type, comprising a clamping member (7) capable of being driven in rotation and a key (11) for driving this clamping member (7), provided with an operating arm (17 ), this key (11) and the clamping member (7) being united by a connecting device (9) arranged so that the key (11) can tilt relative to the clamping member (7) around a tilting axis (Y-Y ') perpendicular to the screw axis (X-X') of said clamping member (7) so as to allow it to be placed in the rest position substantially perpendicular to said screwing axis and can cause the clamping member (7) rotating about said screw axis (X-X '), in the tightening or loosening direction, or freely rotating relative to the clamping member (7), about said axis of rotation screwing (X-X '), over a range of angular deflection (α) of at least 170 °, in the opposite direction to the clamping direction after immobilization of said clamping member (7), at the end of e tightening maneuver. Clamping device according to claim 1, characterized in that the rotary clamping member (7) of the screw-nut system (7-8) connected to the operating key (11) is constituted by the nut (7) of said system. Clamping device according to one of claims 1 or 2, characterized in that the clamping member (7) and the operating key (11) of the connecting device (9) are provided respectively with means (16, 21 ) coming into contact with each other, during the rotation of said key, on the one hand, in the direction of the screwing (F1) of the clamping member (7) when the key (11) is located at one end of the angular deflection range (α), and also in the direction of unscrewing (F ₂ ) of the clamping member (7) when the key (11) is at a second end of the range of angular deflection (α). Clamping device according to one of Claims 1 to 3, characterized in that the connecting means (9) between the drive key (11) and the clamping member (7) comprise: - an annular groove (14) formed in the outer cylindrical surface (15) of the body of the clamping member (7) and in the bottom of which is housed a drive stop (16) oriented parallel to the axis of screwing (X-X ') said clamping member (7); a rotatable tubular cap (10) in which is housed the body of said clamping member (7) and having two diametrically opposite holes (26a, 26b) opening into the annular groove (14) of said clamping member (7), and - an arrangement of a head (18) of the drive key (11) wherein said head (18) is in the form of a fork with two branches (19, 20), the ends of these branches being bent or formed in a direction towards each other and engaged with a rotational ability in the diametrically opposed holes (26a, 26b) of the rotary cap (10), at least one (21) of these curved ends being dimensioned to extend through said groove (14) and come into contact with the stop (16) for driving the clamping member (7) during the operation of said key. Clamping device according to claim 4, characterized in that the bent end of the second leg (20) of the fork (18) is dimensioned so that it does not come into contact with the drive stop (16) of the clamping member (7), when pivoting the key (11) about the screw axis (X-X '), relative to the clamping member (7). Clamping device according to any one of claims 1 to 5, characterized in that said connecting device (9) provides an unmountable connection between the key (11) and the clamping member (7). Clamping device according to any one of claims 1 to 5, characterized in that said connecting device (9) provides a detachable connection between the key (11) and the clamping member (7), at least in the absence of clamping by this clamping member (7). Clamping device according to claim 7, characterized in that the clamping member (7) comprises a notch (27) for lateral access to said annular groove (14), for the passage of at least one of said branches (19). 20) to said annular groove (14), one of said holes (26a, 26b) of the hat (10) having the shape of a slot (26b) having an open end for the passage of one of said branches (19). , 20). Clamping device according to any one of claims 1 to 8, characterized in that the key (11) comprises an operating arm (17) provided with an extension (12) with which this operating arm forms a telescopic handle ( 28), said extension (12) being movable along the operating arm (17) between a retracted position and an extension position of the telescopic handle (28). Clamping device according to claim 9, characterized in that the key (11) comprises a stop (22b) for retaining the extension (12) on said operating arm (17). Clamping device according to any one of the preceding claims, characterized in that the key (11) comprises an operating arm (17) or a handle (17-28) of which at least part (17) is made of a magnetic material. Apparatus, characterized in that it comprises a clamping device (4) according to any one of the preceding claims. Apparatus according to claim 12, characterized in that it is a chain saw (1) which comprises an endless cutting chain (2), as well as a chain guide (3) and a block comprising said clamping device (4) for clamping said chain guide (3) to the body (6) of the apparatus. Apparatus according to one of claims 12 and 13, characterized in that it comprises a zone (29) for storing the clamping arm (17) or a handle (28) of the clamping device (4), in a predetermined angular position of retraction around the screw axis (X-X ') against the casing (5) of the apparatus. Apparatus according to claim 14, characterized in that it comprises a magnet (30) for retaining the operating arm (17) and the handle (28) in the retracted position at said storage area (29).

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