FR2627822A1 - DEVICE FOR LOCKING A TIGHTENING SCREW - Google Patents

Abstract

The present invention relates to a device for locking a clamping screw, the head and part of the body of which remain outside the clamped parts, characterized in that it comprises: - a fixed support 12 in which a recess 16 of the form is arranged. annular arranged around the screw 6; said recess comprising a single opening on the side of the head of the screw 10, partially blocked by a shoulder 17 and a spring 23 placed in its bottom; a movable part 18 having a shoulder 19 and, on its internal face, means 20 capable of cooperating by complementarity of shape with the means of a ring 21 carried by the screw, said movable part 18 being mounted in said recess 16 and moving therein in axial translation and in a non-rotating manner between an unlocking position in which it compresses the spring 23 and releases the ring 21 and a locking position in which the shoulders 17 and 19 are in abutment while the means 20 of said movable part 18 cooperate with the means of the ring 21.

Description

The present invention relates to a device for

locking of a clamping screw.

  To assemble at least two parts, recourse is had to screw-nut systems, collars or jaws of

clamping ...

  These known assembly means comprise a mechanical part which comes into contact with at least one of the parts to be joined and which cooperates with a clamping means, so that, by clamping said assembly means, the solidarity of

parts be assured.

  The assembly means can be a nut, a collar, a

  clamp (clamping jaw), and the clamping means, a screw.

  It is generally desirable that the parts thus joined remain so, even subject to stresses and in particular to vibrations. It is often observed, on rotating machines in particular, that said vibrations cause a

loosen the screws.

  To solve this problem, it is proposed according to the invention

  a screw locking device.

  Said device can be used with any screw, provided that its head and part of its body remain, in the tightened state, external to the parts to be assembled. It is characterized in that it comprises: - a fixed support in which is arranged an annular recess arranged around the screw; said recess comprising a single opening on the side of the head of the screw, partially obstructed by a shoulder and a spring placed in its bottom; - A moving part having another shoulder and, on its internal face, means capable of cooperating by form complementarity with the means of a ring carried by the screw, said moving part being mounted in said recess and moving therein ci in axial translation and non-rotatingly between an unlocking position in which it compresses the spring and releases the ring and a locking position in which the two shoulders are in abutment while the means of said movable part cooperate with the

means of said ring.

  In the present application, the term “spring” means any means capable of deforming elastically so as to allow the

  displacements of the moving part, and in particular a conventional spring.

  Said moving part must "slide" in said annular recess, in a non-rotating manner in order to ensure the

locking in rotation of the assembly.

  This result can be obtained by any means and in particular by the specificity of the shapes of the external face of said moving part and of the internal face of the shoulder of the support; called

  to be vis-à-vis in the locked position.

  The external face of said movable part must be adapted so as to play the role of anti-torque within the annular recess. Said external and internal faces, respectively of said movable part and of said shoulder, may be of shape

  polygonal, in particular hexagonal, square ...

  The rotation lock can also be obtained by

  other means, including pin-type systems.

  In the locked position, said screw and said movable part are secured by means, located respectively on a ring carried by said screw and on the internal face.

of said moving part.

  These means cooperate by complementarity of form. he

  advantageously these are grooves or the like.

  They are nested one inside the other, in the locked position and capable of disengaging to allow the release of the ring and the disengagement of the screw and said movable part, when the screw is screwed in.

example.

  To cause this disengagement, it suffices to exercise a

  pressure on the moving part along the axis of the screw.

  The support of the device according to the invention can be fixed

262 782 2

  on any frame, and in particular on at least one surface of the parts to be clamped.

  Advantageously, it is fixed to a perpendicular surface.

  cular to the axis of rotation of the screw.

  Any method of attachment is suitable, and in particular attachment

by welding.

  The device according to the invention is advantageously used to lock screws used in combination with

  clamps (clamps), collars.

  Said device has the advantage of simplicity in its

design and operation.

  Indeed, it consists of a small number of parts, easily machinable, and operates by simple pressing on the moving part during the screwing of the screw, for example by pressing the

screwdriver.

  Therefore, it is ideal for remote operations, for example by remote manipulator, robot ... and can therefore advantageously be used in areas inaccessible to

  man, radioactive zones for example.

  It should also be noted that it can be placed on a screw, the axis of which is oriented in any direction, in particular

  in a horizontal, vertical, oblique plane.

  The device according to the invention will now be described for better understanding, with reference to the accompanying drawings, in which: FIG. 1 is an elevational view, in section, of a device according to the invention, for locking a screw used in combination with a clamp. The system in the locked position is shown on the left side of the figure; sure. the part

  right, the system is shown in the unlocked position.

  - Fig. 2 is an exploded perspective view of certain elements

  of the device according to the invention of FIG. 1.

  Let the parts 1 and 2 to be joined, which each have a surface (3) (4), the shapes of which fit together for a

good contact between them.

  The assembly means is a clamp (5), the tightening of which is controlled by the screw (6), which acts simultaneously on a nut (7). Said nut slides along the screw and in doing so, causes the movement of positioning of the clamp, coming to surround the parts (1) and (2) or its reverse movement. To ensure proper guidance of the foot (8) of the screw, a recess (9) has been provided

  on the external surface of the part (2) in contact with the screw.

  The parts (1) and (2) being brought into contact with each other by their surfaces (3) (4), the clamp and the screw being placed so that the clamp surrounds said parts; the screw is then tightened from its head (10), the nut (7) rises, the foot (11) of the clamp and the foot (8) of the screw are then supported on the parts (1) (2) ; tightening is continued until the

desired constraint.

  This device and its operation are perfectly known. According to the invention, a device is proposed for

  locking of the assembly thus obtained.

  It consists of the support (12) fixed on the part (2), more precisely on the surface (13) thereof. Said support is

fixed by welding (14).

  The support (12) comprises a part (15) arranged around the screw and in which the shaped recess (16) is arranged.

  annular, whose axis of revolution is that of the screw.

  The recess (16) has only one opening on the side of the head of the screw (10). This opening does not occupy the entire face of

  the recess, a shoulder (17) of the support partially obstructs it.

  In this recess, the movable part (18) slides freely, which is provided with a shoulder (19) which, coming to bear on the shoulder (17), prevents this part from coming out of the recess. The width of said recess is just greater than that of the shoulder (19)

to ensure sliding.

  The part (18) is provided on its internal face (that facing the screw) with grooves thus forming a toothed part (20) which can come to fit on the ring (21) carried by the screw

  which is also provided with grooves, of the same dimensions.

  The movement of the ring (21) is controlled by the screw.

  That of the movable part (18) is independent of the screw. It is controlled from a force applied by the operator on the surface (22) of the movable part (18), surface directed towards the screw head. The spring (23) placed in the bottom of the recess absorbs

  displacement towards the foot of screw.

  When the operator releases his pressure, the moving part (18) moves in the opposite direction under the action of the spring and

  abuts against the shoulder (17) of the recess.

  During these movements, the toothed part of the movable part either meets the toothed ring, or escapes from it. The length of the travel of the moving part in the recess is such that this contact between the toothed parts is possible as well as non-contact. From this data, the length of the recess and

the spring are chosen.

  During the screwing operation, the operator exerts pressure on the face (22) of the moving part (18) so that the toothed part (20) moves away from the ring (21). The screw thus released can be tightened, the moving part being prevented from rotating during this operation (role of anti-torque) thanks to an appropriate external shape, hexagonal in the present case, the same shape equipping the face of the screw support. opposite. In Figure 1, these are the outer face (24) of the movable part and the inner face (25) of the shoulder (17). To keep the screw in its axis during this operation, a stop (26) is mounted,

it is supported on the support.

  The screwing being finished, the operator releases his pressure on the movable part (18); under the action of the spring (23) which then relaxes, the movable part (18) rises until the shoulders (17) (19) come into abutment. In doing so, the ring (21) and the toothed part (20) come into contact. The nested grooves then prevent any lateral movement (that is to say perpendicular to the axis of rotation of the screw). Locking is then ensured against any possibility of loosening of the screw. The shoulders (17) (19) being in abutment, the contact cannot be broken by an additional displacement of the part

  movable towards the screw head.

  In FIG. 2, certain elements of the device are shown according to FIG. 1. In particular, we can better visualize the

  external shape of the movable part (18).

Example

  - Dimensions of the screw: 0 = 16 mm (diameter) - Dimensions of the annular recess: length = 16 mm 0 outside = 50 mm 0 inside = 32 mm - tightening torque applied to the head of the screw (hexagon of which the

  flat to flat distance is 24 mm) = 6 m / kg.

- steel spring.

  This device is used to fix an engine to a frame

  used fuel shears.

Claims (8)

Claims:   1. Locking device for a clamping screw, the head and a part of the body of which remain external to the clamped parts, characterized in that it comprises: - a fixed support (12) in which a recess (16) is arranged. annular shape arranged around the screw (6); said recess comprising a single opening on the side of the head of the screw (10), partially obstructed by a shoulder (17) and a spring (23) placed in its bottom; - A movable part (18) having a shoulder (19) and, on its internal face, means (20) capable of cooperating by form complementarity with the means of a ring (21) carried by the screw, said movable part (18) being mounted in said recess (16) and moving therein in axial translation and in a non-rotating manner between an unlocking position in which it compresses the spring (23) and releases the ring (21) and a position locking in which the shoulders (17) and (19) are in abutment while the means (20) of said   moving part (18) cooperate with the means of the ring (21).   2. Device according to claim 1, characterized in that the external face (24) of the movable part (18) and the internal face (25) of the shoulder (17) are shaped to ensure the rotation lock.   3. Device according to claim 2, characterized in that said external (24) and internal (25) faces are polygonal, by hexagonal example.   4. Device according to any one of claims 1 to   3, characterized in that the means (20) of the movable part (18) and   those of the ring (21) consist of grooves.   5. Device according to any one of claims 1 to   4, characterized in that the support (12) is fixed to at least one surface of the parts to be clamped.   6. Device according to any one of claims 1 to   , characterized in that the support (12) is fixed on a surface   perpendicular to the axis of rotation of the screw.   7. Device according to any one of claims 1 to   6, characterized in that the screw is used in combination with a clamp.   8. Device according to any one of claims 1 to   6, characterized in that the screw is used in combination with a collar.