Cross-drilling milling unit for lower spindle

Description

1. Field of the Invention

[0001] The present invention relates to a cross drilling-milling unit for a sub spindle, and more particularly to a cross drilling-milling unit which can prevent a mandrel from tilting when adjusting the mandrel.2. Description of Related Art

[0002] A conventional cross drilling-milling unit for a sub spindle, also known as a side milling holder for back processing, is mounted to a machine tool for side milling a workpiece, and comprises a body, a transmitting assembly, and a mandrel assembly. The body includes a mounting portion for the mandrel assembly to be disposed therethrough. The mounting portion has a slit which separates the mounting portion into two bulks. The two bulks are configured to clamp the mandrel assembly when an adjusting screw forces the two bulks to approach each other. The transmitting assembly is mounted inside the body, and is configured to be driven by a spindle of the machine tool and rotate the mandrel assembly. A cross drilling-milling unit on which the preamble of appended claim 1 is based is known from Patent Document US 2002 / 185289 A1.

[0003] When a user intends to adjust an axial position of the mandrel assembly, he / she may loosen the adjusting screw, then the two bulks may separate from each other, so the user can move the mandrel assembly to an appropriate position and fasten the adjusting screw to fix the mandrel assembly again.

[0004] However, when the two bulks are loosened, the mandrel assembly loses support or limitation in a sudden, so the mandrel assembly tends to tilt. When the two bulks once again clamp and hold the mandrel assembly, the mandrel assembly may be held in the tilted manner relative to an original axis. As a result, the following processing will be done inaccurately beyond tolerance, and an adverse effect may happen to transmission between the transmitting assembly and the mandrel assembly.

[0005] The main objective of the present invention is to provide an improved structure of a cross drilling-milling unit for a sub spindle to solve the above-mentioned problems.

[0006] The present invention provides a cross drilling-milling unit for a sub spindle having a body and a mandrel assembly. The body has a first direction, a second direction being perpendicular to the first direction, and a mounting portion having a first deck, a second deck, and a third deck arranged along the first direction in order and spaced apart from one another. The mandrel assembly is disposed through the first deck, the second deck, and the third deck along the first direction and is mounted on the mounting portion. The second deck has a slit disposed along the second direction and separating the second deck into two bulks, and the two bulks are configured to clamp the mandrel assembly when forced to move toward each other.

[0007] Other objectives, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.

[0008] In the drawings: Fig. 1 is a perspective view of a preferred embodiment of a cross drilling-milling unit for a sub spindle in accordance with the present invention; Fig. 2 is an exploded view of the cross drilling-milling unit in Fig. 1; Fig. 3 is a front view in partial section of the cross drilling-milling unit in Fig. 1; Fig. 4 is a side view in partial section of the cross drilling-milling unit in Fig. 1; and Fig. 5 is an enlarged top view in partial section of the cross drilling-milling unit in Fig. 1.

[0009] With reference to Figs. 1 and 2, a preferred embodiment of a cross drilling-milling unit for a sub spindle in accordance with the present invention comprises a body 10, a driving assembly 20, a gear box 30, a mandrel assembly 40, an adjusting assembly 50, and a set screw 60.

[0010] With reference to Fig. 1, a body 10 defines a first direction D1, a second direction D2, and a third direction D3, all of which are mutually perpendicular. The body 10 has a substantially inverted L-shaped configuration. Furthermore, the body 10 comprises a mounting portion 11 having a first deck 111, a second deck 112, and a third deck 113 that are formed along the first direction D1 in order and spaced apart from one another.

[0011] With reference to Figs. 2 and 3, the driving assembly 20 is mounted inside the body 10, extends along the first direction D1, and comprises a shaft 21 protruding from the body 10 along the second direction D2. The driving assembly 20 is rotatable via a gear module.

[0012] With reference to Figs. 2 and 3, the mandrel assembly 40 is mounted on the mounting portion 11 of the body 10 through the first deck 111, the second deck 112, and the third deck 113 along the first direction D1. With reference to Figs. 2 and 3, the gear box 30 is mounted on a side of the body 10 along the first direction D1, and covers the driving assembly 20 and the mandrel assembly 40. The gear box 30 has a transmitting gear module inside for torque transmission. The driving assembly 20 is capable of rotating the transmitting gear module inside the gear box 30, and further rotating the mandrel assembly 40. Since specific structures and principles of transmission of the driving assembly 20 and the gear box 30 are prior arts, detailed descriptions are omitted.

[0013] With reference to Figs. 1, 4, and 5, the second deck 112 has a slit extending along the second direction D2 and separating the second deck 112 into two bulks 114. When the two bulks 114 are forced to approach each other, the two bulks 114 clamp the mandrel assembly 40. Specifically, in the preferred embodiment of the present invention, with reference to Figs. 4 and 5, the adjusting screw 50 penetrates one of the two bulks 114 of the second deck 112 along the second direction D2, a head of the adjusting screw 50 is engaged in the bulk 114, and the adjusting screw 50 is mounted with the other one of the two bulks 114 by threads. In this way, when the adjusting screw 50 is tightened up, the two bulks 114 are thereby forced to approach each other, so as to provide an attracting force for the two bulks 114.

[0014] With the aforementioned technical features, when a user intends to reset the mandrel assembly 40, he / she may loosen the adjusting screw 50, the two bulks 114 of the second deck 112 thereby release the mandrel assembly 40, and the user may change a position of the mandrel assembly 40 relative to the mounting portion 11 along the first direction D1. During this process, the first deck 111 and the third deck 113 still provide necessary constraints to two ends of the mandrel assembly 40 on two sides of the second deck 112 to prevent tilt and swing of the mandrel assembly 40 and keep the mandrel assembly 40 extending along the first direction D1 to overcome the problems of the conventional cross drilling-milling unit for a sub spindle.

[0015] Moreover, with reference to Figs. 2 and 3, the mandrel assembly 40 comprises a sleeve 41 and an output shaft 42 rotatably disposed in the sleeve 41. The first deck 111 has a cavity 115 and a through hole 116 disposed on a side of the first deck 111 facing the gear box 30. The cavity 115 and the through hole 116 jointly form a stepped edge, facilitating the sleeve 41 of the mandrel assembly 40 to be supported by the cavity 115 and further to extend through the second deck 112 and the third deck 113 via the through hole 116.

[0016] In the preferred embodiment of the present invention, the first deck 111 is a single-block structure, not being divided by any slit such that the through hole 116 has a closed periphery. Therefore, when the adjusting screw 50 is loosened, constraining capability of the first deck 111 for the sleeve 41 is improved. The third deck 113 may have a similar configuration as well. In another embodiment, the configurations of the first deck 111 and the third deck 113 may be similar to that of the second deck 112, i.e. two-bulk structures that may be adjusted by adjusting screws. As long as the mandrel assembly 40 is not fixed by any one of the first deck 111 and the third deck 113 to an extent that its position cannot be adjusted, the user may only operate the adjusting screw 50 on the second deck 112 to adjust the mandrel assembly 40, and this embodiment also satisfies the purpose of the present invention, namely the effect of constraining the two ends of the mandrel assembly 40 to prevent tilt.

[0017] Preferably, with reference to Figs. 2 and 3, the sleeve 41 has an elongated groove 411 disposed radially on an outer surface of the sleeve 41 and extending along the first direction D1. The set screw 60 is mounted through the first deck 111 of the body 10 along the second direction D2 and extends into the elongated groove 411. In this way, the set screw 60 is capable of preventing the sleeve 41 from rotating relative to the mounting portion 11 of the body 10, thereby further constraining the sleeve 41 to solely move along the first direction D1 relative to the mounting portion 11, so avoidable processing error when the mandrel assembly 40 is clamped may be prevented.

[0018] With the aforementioned technical features, the present invention provides the user with the effect to prevent the mandrel assembly 40 from tilting and swinging when the user adjusts the position of the mandrel assembly 40 by providing two-position constraints with the first deck 111 and the third deck 113. The problems of the conventional cross drilling-milling unit for a sub spindle is therefore effectively solved, processing precision is improved, and transmitting effect is kept in a good manner.

Claims

1. A cross drilling-milling unit for a sub spindle, characterized in that the cross drilling-milling unit comprises: a body (10) having a first direction (D1) and a second direction (D2) being perpendicular to the first direction (D1), and comprising a mounting portion (11); characterised in that the mounting portion (11) has a first deck (111), a second deck (112), and a third deck (113) arranged along the first direction (D1) in order and spaced apart from one another; and a mandrel assembly (40) is disposed through the first deck (111), the second deck (112), and the third deck (113) along the first direction (D1), and is mounted on the mounting portion (11); wherein the second deck (112) has a slit (110) disposed along the second direction (D2) and separating the second deck (112) into two bulks (114), and the two bulks (114) are configured to clamp the mandrel assembly (40) when forced to move toward each other.

2. The cross drilling-milling unit as claimed in claim 1, wherein the first deck (111) has a through hole (116) disposed therethrough along the first direction (D1), having a closed periphery, and configured for the mandrel assembly (40) to be disposed through.

3. The cross drilling-milling unit as claimed in claim 1, wherein the mandrel assembly (40) comprises a sleeve (41) having an elongated groove (411) disposed radially on an outer surface of the sleeve (41) and extending along the first direction (D1); and the body (10) comprises a set screw (60) mounted through the first deck (111) of the body (10) along the second direction (D2) and extending into the elongated groove (411).

4. The cross drilling-milling unit as claimed in claim 2, wherein the mandrel assembly (40) comprises a sleeve (41) having an elongated groove (411) disposed radially on an outer surface of the sleeve (41) and extending along the first direction (D1); and the body (10) comprises a set screw (60) mounted through the first deck (111) of the body (10) along the second direction (D2) and extending into the elongated groove (411).

5. The cross drilling-milling unit as claimed in any one of claims 1 to 4, wherein the body (10) comprises an adjusting screw (50) passing through one of the two bulks (114) and connected with the other one of the two bulks (114) so as to force the two bulks (114) to approach one another.

6. The cross drilling-milling unit as claimed in claim 5, wherein the body (10) has a third direction (D3) which is perpendicular to the first direction (D1) and the second direction (D2), and the adjusting screw (50) is configured to force the two bulks (114) to approach one another along the third direction (D3).