FR2742373A3 - Screw mounted machine tool adjuster - Google Patents

Abstract

The adjuster includes two screws with a pointer (24) or measurement scale (13) on the head end. The pointer is located on a cap (22) which is fitted on the head of the inner screw. The measurement scale is located on a collar which is axially fixed to the hollow outer screw (2).An elastic friction ring fits between the body of the outer screw and the collar. A plain washer fits between the end of the outer screw and the machine part to which the inner screw is fitted

Description

Screw adjusting device, in particular for machine tools La

  The present invention relates to a screw adjustment device in particular for machine tools. In the machine tool sector, it is often necessary to be able to reliably adjust the reciprocal position between two parts, in order to prepare the machine for the execution of a specific machining. This requirement arises, for example, in the case of profiling machines, where for each cage it is necessary to be able to modify the position of the movable flange supporting the axis of a profiling roller with respect to the flange and the fixed shaft; or in the case of straighteners where it is necessary to be able to modify the position of the mobile straightening rollers relative to the fixed straightening rollers in order to obtain a positioning

  correct reciprocal of the various parties.

  A known adjustment device comprises a screw fixed to one end of the movable flange of the machine and engaging in a threaded ring locked axially, but free to rotate relative to the fixed structure. The rotation of the threaded ring causes the axial displacement of the screw and, consequently, the vertical movement of the flange, to which the screw is assembled, relative to the

  structure, to which the ring is assembled.

  As a rule, a graduated scale device is applied to this ring, allowing precise adjustment and at the same time the display of the

desired displacement.

  This solution achieves the primary goal, that is to say to obtain the desired setting,

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  but it is expensive and requires laborious mounting of the threaded ring on the head and imposes a high height of this ring and therefore of the head part on which it must be applied. Furthermore, the assembly of the graduated scale device is quite complex and requires a number

high of pieces.

  Another known adjustment device comprises a screw, one end of which is T-shaped and which is connected to the movable flange of the machine so as to be able to rotate relative to the latter, but without being able to effect any axial movement. The threaded rod of the screw passes through a tapped hole provided in the structure so that after the rotation of the screw, the latter also moves axially relative to the tapped hole and thus causes the displacement of the flange. mobile by

compared to the fixed structure.

  Like the previous one, this solution is also quite expensive since it requires difficult machining of the T-end of the screw and of the movable head of the machine, in which the T-end

  of the screw must be able to enter and pivot.

  Furthermore, this solution presents a certain difficulty with regard to the application of a device with a graduated scale, given that the structure is already by itself.

quite complex.

  According to the invention, the problem is solved by means of a screw adjustment device, in particular for machine tools, comprising a first hollow screw threaded outside to engage in a first part of a machine tool. and housing inside a second threaded screw outside and

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  fixed at one end to a second part of the machine tool, the first and second screws being provided with means for preventing the axial exit of the first screw relative to the second screw, characterized in that at the head ends of the two screws are provided respectively an index and a

scale.

  According to a characteristic of the invention, the index is provided on a cap applied to the head of the second screw, and the graduated scale is provided on a ring locked axially with respect to

the first screw.

  As a variant, the graduated scale can be provided on said cap and the index can be provided on

said ring.

  Typically, an elastic friction ring is interposed between the body of the first screw and the ring. In addition, the device may include an elastic washer interposed between one end of

  the first screw and the second part of the machine-

  tool, on which the second screw is screwed.

  According to another characteristic of the invention, the second screw is fixed to the second part of the

  machine tool by at least one lug.

  According to yet another characteristic of the invention, a lock nut cooperating with the first part of the machine tool is associated with the first screw to prevent rotation of the first

  screw, when the desired setting is obtained.

  In addition, the head of the second screw can be

  applied to a friction washer.

  Other characteristics and advantages of the present invention will appear more clearly on

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  reading the following description of several

  preferred embodiments of the invention with reference to the corresponding accompanying drawings in which: - Figure 1 is a front view of the device on a graduated scale; and - Figure 2 is a longitudinal sectional view of the screw adjustment device according to the invention applied between the movable flange and the fixed structure

of a profiling group.

  As it appears in the figures, the device according to the invention comprises a first hollow screw 2, having an external thread substantially over its entire length. This screw is extended beyond an operating head 4 by an annular body 6 comprising a peripheral groove 8, in which is housed an elastic ring 10 cooperating by friction with a plastic ring 12 on which a scale

graduated 13 is applied.

  The screw 2 has over its entire length an internal axial hole 14, inside which is housed a second screw 16 provided with a head 18 and the opposite end of which is threaded. The screw 16 has an annular groove 20 in which engages a cap 22 also designed in plastic, on

  the outer surface of which an index finger 24 is provided.

  Below this head 18 is mounted a

friction washer 17.

  For use, for example on a profiling group, after having engaged the hollow screw 2 in a corresponding transverse threaded orifice formed in the fixed structure 26 of said profiling group, the screw 16 is introduced inside the hollow screw 2 and is assembled by its threaded end in the

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  movable flange 28 of the group. The screw 16 is fully screwed when the washer 17 is in full support on the annular body 6 in the ring 12 and when the lower edge of this screw 2 abuts against the flange 28 an elastic washer 30

which is sandwiched between them.

  Once the screw 16 is screwed onto the head 28, it is permanently locked in the correct position by

a lug 32.

  Furthermore, the ring 12 is turned to bring the 0 of the graduated scale into correspondence

with index finger 24.

  To adjust the position of the movable flange 28 relative to the fixed structure 26, it suffices to rotate the screw 2 using any tool. This rotation, allowed by the elasticity of the washer 30, causes the axial displacement of the screw 2 and consequently of the screw 16 and its head

  18, relative to the fixed headstock 26.

  Since each notch of the graduated scale 13 corresponds to a predetermined axial displacement of the screw 2, it is possible to

  determine the position you wish to obtain.

  At this stage, the hollow screw 2 is blocked by

  relative to the structure 26 by a lock nut 34.

  All of the above clearly shows that the screw adjustment device according to the invention is very advantageous compared to traditional screw devices since its realization is very simple since it requires only a simple tapped orifice in the two parts 26 and 28 between which the adjustment must be made. Besides, its use is quite simple. In addition, thanks to the presence of the elastic washer 30, it makes it possible to make up for play that can be caused as well.

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  by the use as by vibrations due to both the use and any manual adjustments. Finally, this device allows a reversible use, that is to say, it allows to maintain fixed indifferently one of the two parts and to modify the position of the other. Then thanks to the presence of the index and the graduated scale, it makes it possible to determine in a

reliable reciprocal displacement.

  According to an alternative embodiment not shown in the drawings, the graduated scale is

  provided on the cap 22 while the index finger is provided on the collar 12.

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Claims (9)

  1. Screw adjustment device in particular for machine tools, comprising a first hollow screw (2) threaded on the outside to engage in a first part (26) of a machine tool and accommodating the inside a second screw (16) threaded on the outside and fixed by one end to a second part (28) of the machine tool, the first and second screws (2, 16) being provided with means to prevent the axial exit of the first screw (2) relative to the second screw (16), characterized in that at the head ends (6, 18) of the two screws are provided respectively an index (24) and a scale graduated (13).   2. Device according to claim 1, characterized in that the index (24) is provided on a cap (22)   applied to the head (18) of the second screw (16).   3. Device according to claim 1, characterized in that the graduated scale (13) is provided on a ring (12) locked axially relative to the first screw (2).   4. Device according to claim 3, characterized in that an elastic friction ring (10) is interposed between the body of the first screw (2) and the ring (12).   5. Device according to claim 1, characterized in that it comprises an elastic washer (30) interposed between one end of the first screw (2) and the second part (28) of the machine tool, on   which is screwed the second screw (16).   6. Device according to claim 1, characterized in that the second screw (16) is fixed to the second part (28) of the machine tool by at least one lug (32). 8 2742373   7. Device according to claim 1, characterized   in that the first screw (2) is associated with a counter   nut (34) cooperating with the first part (26) of the machine tool to prevent rotation of the first screw (2), when the desired adjustment is obtained. 8. Device according to claim 1, characterized in that the graduated scale (13) is provided on a cap (22) applied to the head (18) of the second screw (16), and the index (24) is provided on a ring (12) locked axially relative to the first screw (2). 9. Device according to claim 1, characterized in that the head (18) of the second screw (16) is   applied to a friction washer (17).