FR2845442A1 - Fixing device for mechanical parts of variable thickness comprises cylindrical rod with end support surface contacting first part to be fixed and outer body with support surface contacting second part - Google Patents

Abstract

The fixing device (10) comprises a cylindrical rod (14) having a support surface (18) at one end which comes into contact with the first part to be fixed. An outer body (28) comprises a support surface (33) which comes into contact with the second part. An internal cylindrical body (40) located between the rod and the outer body comprises locking means (54,56) which engage rod stop means (34,35) to leave free sliding of the internal body on the rod and lock it relative to the rod according to determined axial positions. The internal and outer bodies comprise adjustment means (38,42) for continuously adjusting the axial position of the internal cylindrical body relative to the rod.

Description

DEVICE FOR FIXING PI CES M CANICS

  The present invention relates to a device for fixing mechanical parts of variable thicknesses.

  The fixing of mechanical parts of variable thicknesses can be obtained by means of a bolt consisting of a screw and a nut. When the parts to be fixed can have variable thicknesses, the length of the screw is provided large enough to suit all possible thicknesses

mechanical parts to be fixed.

  Therefore, in the case where the thicknesses of the parts to be fixed are small compared to the length of the screw, the operation of screwing the nut onto the screw can prove to be long and tedious insofar as nut must be screwed on a

  large portion of the screw length.

  To overcome this drawback, there are so-called quick-mounting nuts 15 which allow an approximate and rapid pre-adjustment of the position of the nut relative to the screw, and then a precise adjustment of the position. of the nut relative to the screw to achieve the final fixing of the parts to be fixed. An example of a quick-mount nut consists of a split nut over its entire length such that, without external action, the internal thread of the nut does not cooperate with the thread of the screw. The nut can then be positioned quickly and approximately on the screw. A washer comprising a conical part is slidably mounted on the screw. By cooperating with the nut, the washer can force the reduction in the internal diameter of the nut so that the internal thread of the nut comes into contact with the external thread of the screw. The final position of the nut

  can then be precisely adjusted by screwing.

  A disadvantage of this type of quick-mounting nut is that the forced contacting of the threads of the nut and of the screw risks causing deterioration of the threads, in particular when the materials constituting the screw and the nut are different. Such a quick-mounting nut can then only accept a limited number of mounting and dismounting operations. The present invention presents a fixing device allowing rapid pre-adjustment of the device for use with pieces to be fixed of variable thicknesses.

  not having the aforementioned drawback.

  For this purpose, it provides a device for fixing first and second parts, comprising a cylindrical rod passing through the first and second parts and comprising at one end a bearing surface adapted to come into contact with the first part; an external body mounted coaxially on the rod and comprising a bearing surface adapted to come into contact with the second part; and an internal cylindrical body disposed between the rod and the external body and comprising a locking means adapted to cooperate with means for stopping the rod to allow the internal cylindrical body to slide freely on the rod and to block the internal cylindrical body by ratio 30 to the rod according to determined axial positions, the internal cylindrical body and the external body comprising adjustment means for continuously adjusting the axial position of the

  internal cylindrical body relative to the rod.

  According to one embodiment of the invention, the locking means and the stop means are adapted to allow the internal cylindrical body to slide freely on the rod when it is in a first angular position relative to the rod and blocking the internal cylindrical body relative to the rod in discrete axial positions when it is in a second angular position relative to the rod. According to one embodiment of the invention, the

  adjustment means comprise a thread arranged on an external face of the internal cylindrical body cooperating with a threaded opening of the external body.

  According to one embodiment of the invention, the threaded opening comprises a shoulder against which the body

  internal cylindrical is adapted to come into abutment.

  According to one embodiment of the invention, the blocking means comprises at least one lug and the stop means 15 comprise notches projecting relative to the surface of the rod and aligned along a generatrix of the rod, said lug being disposed between two notches in the second angular position to block the internal cylindrical body in sliding

relative to the rod.

  According to one embodiment of the invention, the

  stop means comprise a stop strip projecting from the surface of the rod, said lug pressing against the stop strip in the second angular position so as to block the internal cylindrical body in rotation in a 25 direction relative to the rod.

  According to one embodiment of the invention, the rod comprises two series of notches, the notches of each series of notches being also distributed along two generatrices of the rod diametrically opposite, the internal cylindrical body 30 comprising two lugs, each lug being adapted to cooperate

  with the notches of one of the two sets of notches.

  According to one embodiment of the invention, the lug protrudes relative to the surface of an internal opening passing through the internal cylindrical body, the lug extending substantially over less than a quarter of the diameter of the internal opening. According to one embodiment of the invention, each notch extends substantially over less than a quarter of the diameter of the rod. According to one embodiment of the invention, the device comprises a means for blocking the rotating rod

compared to the first piece.

  This object, these features and advantages, as well as others of the present invention will be explained in detail.

  in the following description of particular embodiments given without limitation in relation to the figures

  among which: FIG. 1 shows a perspective view of a first embodiment of a fixing device according to the invention mounted on a part to be fixed; FIG. 2 represents an axial section of a second embodiment of the fixing device according to the invention; Figure 3 shows a side view of an isolated element of the device of Figure 2; Figure 4 shows a section of Figure 3 along line IV-IV; Figure 5 shows a top view of another isolated element of the fixing device of Figure 2; Figure 6 shows a section of Figure 5 along line VI-VI; Figure 7 shows a side view of a variant of the element of Figure 2; and Figure 8 shows a sectional view of a variant

of the element of figure 5.

  FIG. 1 represents a perspective view of a first embodiment of the fixing device 10 according to the invention intended to fix a first mechanical part 35 12 on a second part (not shown). The device 10

  comprises a cylindrical rod 14 having at one end a head 16, for example of rectangular section, having a bearing surface 18 adapted to come into contact with the first mechanical part 12. The head 16 can comprise two grooves 20, 22 5 adapted to slide in a slide 24 formed on the first part 12 so as to block the rod 14 in rotation relative to the first part 12. By way of example, a second slide 26 is shown in FIG. 1 allowing different possibilities of positioning the fastening device 10 10 according to the invention to the first part 12.

  The device 10 according to the invention comprises a nut 28 disposed axially on the rod 14. The nut 28 can be a wing nut comprising two ears 30, 32 so as to facilitate the handling of the nut 28 by an operator. The nut 15 28 includes a bearing surface 33 intended to come into contact

with the second part to be fixed.

  The rod 14 comprises two series of notches arranged

  diametrically opposite with respect to the axis of the rod 14.

  Each series of notches comprises notches 34, 35 distributed along a generatrix of the rod 14 substantially from the end opposite to the head 16 as close to said head 16. The notches 34, 35 of each series of notches can be split evenly or not. Each notch 34, 35 corresponds to a cylindrical portion projecting from the surface of the rod 14 which extends over less than a quarter of the diameter of the rod 14. The notches 34, 35 of the same series of notches are connected at one end by a stop strip 36, 37 which extends along a generatrix of the rod 14 and which has a thickness substantially identical to that

notches 34, 35.

  FIG. 2 shows a section of a second embodiment of the device 10 according to the invention in which the rod 14 comprises a smaller number of notches 34, 35 per series of notches compared to the first embodiment. The nut 28 comprises an internal cylindrical threaded opening 38 in which is disposed a cylindrical sleeve 40 comprising on

  its outer wall an external thread 42 cooperating with the threaded opening 38 of the nut 28. The opening 38 comprises a shoulder 44 against which the sleeve 40 may possibly come into abutment. The two series of notches and the stop bands 5 36, 37 delimit two free surfaces 46, 48 of the rod 14 corresponding to cylindrical portions which extend over the entire length of the rod 14. The sleeve 40 comprises an opening interior 52 in which the rod 14 is arranged.

  The rod 14 may have at its end opposite the head 16 a conical end 50 so as to facilitate the introduction of the rod 14 inside the opening 52 passing through the bush 40. The internal opening 52 comprises two protruding lugs 54, 56 adapted to cooperate with the notches 34, 35 of the rod 14

  as will be explained in more detail later.

  FIG. 3 represents the rod 14 of FIG. 2 in isolation. By way of example, for use for fixing a toilet seat to a toilet bowl, the elements constituting the fixing device 10 according to the invention can be made of plastic and the rod 14 can measure approximately 80 mm along its axis. Each notch 34, 35 can

  substantially measure 3.75 mm along the axis of the rod 14, the axial distance between two notches 34, 35 can be 3.75 mm.

  As appears more clearly in FIG. 4, the radial thickness r of the notches 34, 35 and the stop strips 36, 25 37 can be 3 mm. The width 1 of the stop bands 36, 37

may be substantially 1.8 mm.

  FIGS. 5 and 6 respectively represent a top view and a section of the sleeve 40. The axial width of each lug 54, 56 is slightly less than the distance 30 separating two successive notches 34, 35 from the same series of notches the rod 14. The pins 54, 56 are disposed substantially at the level of the perpendicular median plane of the sleeve 40 and are diametrically opposite. Each lug 54, 56 extends substantially over less than a quarter of the diameter of the interior opening 52 of the socket 40. For example, each lug 54, 56 extends over one sixth of the diameter of the opening interior 52 of the

socket 40.

  The method of mounting the fixing device 10 according to the invention is as follows: The rod 14 is arranged on the first part 12 to

  fix so as to be locked in rotation relative to the first part 12. The sleeve 40 is screwed inside the nut 28 so as to abut against the shoulder 44.

  The assembly consisting of the sleeve 40 and the nut 28 is then presented at the free end of the rod 14 so that each

  lug 54, 56 of the socket 40 is disposed opposite a free surface 46, 48 the rod 14. The assembly consisting of the socket 40 and the nut 28 is then free to slide along the axis of the rod 14 until the bearing surface 15 of support 33 of the nut 28 is pressed against the second part to be fixed.

  In this position, the pins 54, 56 are not

  generally not perfectly opposite a space separating two successive notches 34, 35 from a series of notches of the rod 14.

  The nut 28 is then screwed by means of the ears 30, 32. The rotation movement imposed on the nut 28 rotates the sleeve 40. Each lug 54, 56 then comes into abutment against a notch 34, 35 of a series of notches of the rod 14, thus blocking in rotation the sleeve 40. The sleeve 40 then moves axially because of the cooperation of the threads of the sleeve 40 and the nut 28. The sleeve 40 then moves away from the shoulder 44 of the nut 28 until each lug 54, 56 faces a free space separating two notches 34, 35 from a series of notches. The sleeve 40 then performs a rotational movement so that each lug 54, 56 penetrates into the space separating two notches 34, 35 until it abuts against the stop strip 36, 37 associated with the series of notches . The sleeve 40 is then blocked in rotation. An additional screwing of the nut 28 then results in a tightening torque exerted on the parts to be fixed. To dismantle the fixing device 10 according to the invention, it suffices to turn the nut 28 in a conventional manner in the direction opposite to the trigonometric direction. In the case where the friction forces between the threads of the socket 40 and of the nut 28 are sufficient, the rotational movement applied to the nut 28 causes the socket 40 to rotate so that each lug 54, 56 frees a space separating two successive notches 34, 35 from a series of notches until it abuts against the stop strip 36, 37 of the opposite series of notches. The assembly formed by the sleeve 40 and the nut 28 is then free to slide axially relative to the rod 14. In the case where the friction forces between the threads of the sleeve 40 and the nut 28 are insufficient , a rotary movement of the nut 28 does not cause the bush 40 to rotate. In this case, as long as the bush 40 remains in the locked position relative to the rod 14, a rotation movement of the nut 28 causes the axial displacement of the nut 28 relative to the rod 14 until the bush 40 comes into abutment against the shoulder 44 of the nut 28. At this time, the bush 40 being blocked against the shoulder 44 of the nut 28, it is rotated and the pins 54, 56 release notches 34, 35 from

the rod 14.

  Figures 7 and 8 show the rod 14 and the sleeve 40 according to a variant of the fixing device 10 of the invention. Each notch 34, 35 comprises a notch 58 at the end of the notch 34, 35 connected to the stop strip 36, 37. Each lug 54, 56 of the sleeve 40 has at one end a protuberance 60 having a shape complementary to the notch 58. When a lug 54, 56 is introduced into the space separating two notches 34, 35, the protuberance 60 penetrates into the notch 58. When the nut 28 is unscrewed to disassemble the fixing device 10, because of the cooperation of the protrusions 60 of the lugs 54, 56 and the notches 58 of the notches 34, 35, the sleeve 40 remains blocked relative to the rod 14 35 until it comes into contact with the 'shoulder 44 of the nut 28. At this time, the sleeve 40 being locked against the shoulder 44 of the nut 28, it is rotated and the protrusions 60 of the lugs 54, 56 are released from the notches 58 of the notches 34,

of the rod 14.

  The present invention has many advantages. It allows rapid mounting and dismounting of the fixing device for parts to be fixed, which may have variable thicknesses. The assembly formed by the sleeve and the nut can be mounted on the rod by simple sliding, a subsequent screwing of the nut then causing the blocking relative to the rod and the tightening of the assembly. The rod can then have a considerable length so that the fixing device according to the invention can be used for

pieces of variable thickness.

  The present invention also makes it possible to carry out

  multiple assembly and disassembly operations avoiding deterioration of the components of the device according to the invention. In fact, the threads of the sleeve and the nut are in permanent contact during assembly or disassembly of the device and are therefore not weakened.

  According to a variant of the invention, the shape of the head of the rod can be adapted according to the parts to be fixed. In particular, the part may include an opening in which the rod is initially inserted, the opening comprising on the side 25 of the face of the part to be fixed opposite the second part an imprint whose shape is complementary to that of the rod

  so as to lock the head of the rod in rotation.

  According to another variant of the invention, each series

  of notches comprises a series of projecting elements distributed over the stop strip of the series of notches on the side opposite the notches.

  Each projecting element of a series of notches is arranged substantially opposite a space separating two notches from the other series of notches and near the notch delimiting said space furthest from the head of the rod . The projecting elements, by cooperating with the pins of the socket, allow

  maintain the assembly formed by the sleeve and the nut relative to the rod when a user mounts said assembly by sliding on the rod and releases it. In addition, the projecting elements define preset positions which, during the rapid presetting of the position of the assembly formed by the nut and the socket with respect to the rod, keep each lug of the socket substantially facing each other. vis-à-vis a space separating two notches from a series of notches, which allows faster locking of the sleeve relative to the rod during the subsequent screwing of the nut.

  According to another variant of the invention, the socket may include more than one lug associated with a series of notches on the rod. For example, the socket may have four lugs. In this case, two diametrically opposite lugs are located at a first transverse plane of the socket. The two other pins, also diametrically opposite, are then each located in the extension of one of the pins in the foreground and at a second transverse plane of the socket distant from the foreground substantially by a distance substantially equal to 20 the distance between two successive notches of a series

  stem notches. The two axially aligned lugs are intended to cooperate with the notches of the same series of notches.

  Such a variant makes it possible to better distribute the stresses

  exerted on the notches and lugs.

  According to another variant of the invention, the stop bar for each series of notches is eliminated. To block the sleeve in rotation relative to the rod, each notch can have a shape such that the axial distance separating two successive notches allows the passage of a lug at one end and prevents it at the opposite end. The pins are then blocked

  sliding and rotating only by the notches.

  According to another variant of the invention, the series of notches of the rod are replaced by a thread produced on the rod having a very large pitch and cooperating permanently with a complementary thread produced on the interior opening of the sleeve. The use of threads with very large pitch allows rapid presetting of the position of the assembly formed by the sleeve and the nut relative to the rod. The fastening device may include means for locking the socket relative to the rod when the position of the socket is preset. The characteristics of the threads connecting the nut to the socket are adapted to apply a tightening torque to the parts to be fixed by screwing the nut once the socket is blocked. This variant is however less simple in design and use than those in the embodiments

previously described.

  Of course, the present invention is susceptible to various variants and modifications which will appear to those skilled in the art. In particular, the materials constituting the elements 15 of the fixing device according to the invention, the number of sets of notches, the number of notches of each series of notches, the profile of each notch and the number of pins of the socket will be especially adapted as a function of the maximum tightening torque that it is desired to be able to apply to the parts to be fixed. In addition, the wing nut can be replaced by a hexagon nut, a square nut or some other form, the screwing of which will be

  made using a suitable tool.

Claims (10)

  1. Fastening device (10) for first (12) and second parts, comprising: a cylindrical rod (14) passing through the first and second parts and comprising at one end a bearing surface (18) adapted to come into contact with the first room; an external body (28) mounted coaxially on the rod and comprising a bearing surface (33) adapted to come into contact with the second part; and an internal cylindrical body (40) disposed between the rod and the external body and comprising a locking means (54, 56) adapted to cooperate with stop means (34, 35, 36, 37) of the rod for allow the internal cylindrical body to slide freely on the rod and block the internal cylindrical body with respect to the rod according to determined axial positions, the internal cylindrical body and the external body comprising adjustment means (38, 42) for adjusting continuously the axial position of the internal cylindrical body by compared to the stem.   2. Fastening device according to claim 1, in which the locking means (54, 56) and the stop means (34, 35, 36, 37) are adapted to allow the internal cylindrical body (40) to slide freely. ) on the rod (14) when it is in a first angular position relative to the rod and to block the internal cylindrical body relative to the rod in discrete axial positions when it is in a second   angular position relative to the rod.   3. Fastening device according to claim 1, in which the adjustment means (38, 42) comprise a thread (42) disposed on an external face of the internal cylindrical body (40) cooperating with a threaded opening (38) of the body. external (28).   4. Fastening device according to claim 1, in which the threaded opening (38) comprises a shoulder (44) against which the internal cylindrical body (40) is adapted to come to a stop.   5. Fastening device according to claim 2,   wherein the locking means comprises at least one lug (54, 556) and the stop means comprise notches (34, 35) projecting from the surface of the rod (14) and aligned according to a generatrix of the rod, said lug being disposed between two notches in the second angular position to lock the internal cylindrical body (40) in sliding relative to the rod.   6. Fastening device according to claim 5, wherein the stop means comprise a stop strip (36, 37) projecting from the surface of the rod (14), said lug (34, 35) being bearing against the stop strip in the second angular position so as to block the internal cylindrical body (40) rotating in a direction relative to the stem.   7. Fastening device according to claim 5, in which the rod (14) comprises two series of notches (34, 35), the notches of each series of notches being also distributed along two generatrices of the diametrically opposite rod, the body internal cylindrical (40) comprising two lugs (54, 56), each lug being adapted to cooperate with the notches of one of the two sets of notches.   8. Fastening device according to claim 5, wherein the lug (54, 56) projects from the surface of an internal opening (52) passing through the internal cylindrical body (40), the lug s' extending significantly over less   a quarter of the diameter of the internal opening.   9. Fastening device according to claim 5, in which each notch (34, 35) extends substantially over less   a quarter of the diameter of the rod (14).   10. Fastening device according to claim 1,   comprising a locking means (20, 22) of the rod (14) in rotation relative to the first part (12).