FR2505222A1 - Finishing cutter for work from thread-cutting lathe - uses support panel opening to site rotary head with flat for cutter mounted over annular guide groove - Google Patents

Abstract

The cutter finishes workpieces after treatment by a thread-cutting lathe and cuts off axial waste from an extremity. It uses an opening (3) in a support-frame (1) to locate the head (7) of a rotatable tool holder (4) driven through reduction gearing (6) by a motor (5). A cutting plaquette is mounted on the exposed face of the head which includes a lateral flat and a circular groove (8). The flat cuts across the groove and the frontal frame face (2) with the opening inclined, the plaquette being demountable, extending across the full width of the groove. The support frame may locate the workpiece and the flat may be tangential to the internal groove wall.

Description

IMPROVED MACHINE FOR FINISHING WORKPIECES
HAS BEEN TAKEN OFF.

 The present invention relates to an improved machine for performing the finishing of various parts having undergone a turning operation.

 Bar turning is a well-known operation which consists of turning small parts (axes, screws.

..) taken from the bar. During this operation, there often remains in the axis of the part a small cylindrical allowance frequently designated by the expression "nipple", expression which will be used in the rest of the description.

 Consequently, there is the problem of eliminating this pin when the part is finished.

 The most widespread solution consists in the manual recovery of the produced part, which notably increases the manufacturing costs.

 To solve this problem, several types of machine have been proposed, these machines essentially comprising a knife driven by a reciprocating rectilinear movement as well as a guiding element making it possible to position and maintain the part on the path of the knife which therefore acts to like a "guillotine".

 The devices offered today however have a number of drawbacks, in particular by the fact that they require different settings depending on the dimensions and / or the shape of the parts to be finished. Thus, for example, it is necessary to adjust the length of the knife stroke according to the size of the pins to be removed.

 In addition, the cutting member being driven by a rectilinear reciprocating movement, it follows a fairly complex assembly and control as well as wear of the moving parts.

 Now we have found, and this is what is the subject of the present invention, a device of simple design, of great efficiency and precision which overcomes the drawbacks of the previous solutions.

In general, the invention therefore relates to a machine for finishing parts, more particularly metal parts, having undergone a bar turning operation, machine which comprises in combination t
- a support frame,
- a window in the front of the frame,
a cutting member which in its course cuts the stud resulting from the machining and which is present at the end of said part, characterized by the fact
- that the cutting member is mounted on a rotary tool holder, passing through the window of the frame, driven in a continuous movement by a motor disposed in the support frame, said rotary tool holder being constituted essentially by a truncated cylinder which has on its upper face a circular groove, the ends of which open freely onto the truncated surface of the cylinder.

Furthermore, in a preferred embodiment of the invention
- the support frame has an inclined flat bearing surface,
the cutting member is removably mounted on the rotary tool holder and has a cutting edge extending over the entire width of the groove,
the inner face of the groove is continuous and is practically tangent to the truncated surface of the cylinder, and serves as a bearing surface for the stud during cutting,
- means for positioning the workpiece to be finished are mounted on the support frame, said positioning means being constituted for example by a disc having openings of different shape and size, disc arranged parallel to the plane bearing face of the support frame and the openings being positioned so that the stud present at the end of the part is automatically placed in the groove of the tool holder and comes to bear on the inside face of said groove, the machined face of the part coming for its part, rest on the front face of the tool holder.

The invention and the advantages which it brings will however be better understood thanks to the embodiment given below by way of indication but not limitation and which is illustrated by the attached diagrams in which
- Figure 1 is a schematic overview, in perspective, partially exploded, showing the different organs of a machine according to the invention, the means for positioning and holding the part associated with the support frame not being represented by simplification measure,
FIG. 2 is a detail view, also in perspective, of a tool holder equipped with its cutting member used on a machine according to the invention,
Figure 3 is a longitudinal section along the axis
AA of FIG. 2 of such a tool holder,
- Figure 4 is an end view according to Figure 2.

 If reference is made to the appended diagrams, and more particularly to FIG. 1, the machine according to the invention consists essentially of a hollow support frame (1) having a flat inclined bearing surface (2), surface comprising a window (3) for example of circular shape.

This window (3) allows the passage of a tool holder (4> entralné via a motor (5) by means of a geared motor (6).

 According to the invention, and as shown in more detail in Figures 2, 3 and 4, the tool holder (4) is in the form of a truncated cylinder which has on its front face (7) a groove circular (8) whose ends (9-10) (see Figure 2) open freely on the truncated surface (11) of the cylinder.

 Furthermore, in accordance with the invention, the internal face (20) of the groove (8) is continuous and is practically tangent to the truncated surface (11) of the cylinder.

 An actual cutting member (12) is mounted on the tool holder (4) for example by means of a flange (13) allowing it to be easily dismantled in order to re-sharpen this cutting member (12) is disposed between the two ends (9-10) of the groove (8) and its cutting edge (14) has a width at least equal to the width of the groove (8).

 The attachment of the tool holder (4) to the output of the gear motor (6) is carried out in a conventional manner, for example by keying.

 The dimensions of the groove (8) are determined according to the dimensions of the parts to be finished, but, taking into account that in most cases, the nipples resulting from bar turning operations have a diameter which does not exceed 3 millimeters, the groove (8) will have a width and a depth of the order of 3 millimeters.

 In order to facilitate the positioning and the maintenance of the part during the finishing operation, additional means (not shown) can be associated with the frame of the machine. These positioning means can be constituted, for example, by an assembly in the form of a disc, mounted on the face (2) of the frame (1), this disc comprising openings of different size and shape, depending on the parts to be treated. , said openings being positioned so that they can be brought into view of the groove (8). In addition, a protective casing can possibly be associated with the assembly in the case where the tool holder (4) crosses the face (2).

 The implementation of such a machine is as follows.

 The tool holder (4) is rotated, continuously, by the motor (5). The part to be finished is brought perpendicular to the face (7) of the support of the tool holder (4), so that the stud which it has at its end automatically penetrates inside the groove (8) of said holder. tool (4). The stud present at the end of the part is supported on the inner face (20) of the groove (8) while the end of the part to be finished is supported on the face (7) of the holder. tool (4). Maintaining the part to be finished in this position is achieved by Fn fixed guide element not shown in Figure 1.ar following the rotation of the tool holder (4), the cutting edge (14) of the cut (12) cuts almost instantly the extra thicknesses (pins) present on the face of the workpiece. Given the fact that the cutting edge (14) and the bearing face (7) of the part are arranged strictly on the same plane, a perfect finish is obtained. Furthermore, given the fact that the groove (8) has open ends (9-10), the cut pieces are automatically evacuated.

Compared to previous machines, the machine according to the invention has many advantages, among which we can cite
- elimination of adjustments (stroke of the cutting tool, regardless of the diameter of the part or the stud,
- a very high cutting capacity and a very high production rate, since the cutting is carried out almost instantaneously,
- a perfect finish considering the fact that the face of the cutting tool and that of the workpiece are located strictly on the same plane,
- easy disassembly of the tool, for example for sharpening.

 In addition, such a machine does not require any qualified personnel for its use taking into account its very great simplicity and the great security which it presents.

 Of course, the invention is not limited to the embodiment described above, but it also covers all the variants produced in the same spirit.

Claims (5)

 1 / Machine for finishing parts having undergone a bar turning operation, machine which comprises in combination  - a support frame (1),  - a window (3) made in the front face (2) of the frame,  - a cutting member (12) which, in its course, cuts the pin resulting from the machining and which is present at the end of said part, characterized by the fact  - that the cutting member t12) is mounted on a rotary tool holder (4), passing through the window (3) of the frame (1), driven by a continuous movement by a motor (5> disposed in the frame support (1), said rotary tool holder (4) consisting essentially of a truncated cylinder which has on its upper face (7) a circular groove (8) whose ends open freely onto the truncated surface (11) of the cylinder.  2 / Machine according to claim 1 characterized in that the face (2) of the support frame (1) is inclined.  3 / Machine according to one of claims 1 and 2 characterized in that the cutting member (12) itself is removably mounted on rotary tool (4) and has a cutting edge (14) extending over the entire width of the groove (8).  4 / Machine according to one of claims 1 to 3 characterized in that the support frame (1) comprises means for positioning the workpiece.  5 / Machine according to one of claims 1 to 4 characterized in that the groove (8) of the tool holder has an inner face (20) circular substantially tangent to the swapped surface (11).