Claims:WE CLAIM :

1. A cross slide assembly of a lathe machine with a slide carriage along z-axis comprising of a :

- cross slide driving assembly which has two portions, with a top portion having an interior to accommodate a bottom portion displacebly therewithin, which is moveable outwardly relate to top portion and a fixed protective cover attached to the edge of top portion extending outwardly to encase the displaced bottom portion therewithin itself,
- the said arrangement characterised in that slide is partitioned into two portions with bottom portion moveable with respect to top portion and slide moveable with respect to fixed protective cover.

2. A cross slide assembly of a lathe machine with a slide carriage along z-axis comprising of :
- a cross slide assembly (A),
- a guide way assembly (B),
- a tool holder assembly (C),
- a drive assembly (D),
- wherein the said cross slide assembly (A) is a x-axis cross slide mounted on a fixed angular bracket attached to the slide carriage and the said cross slide assembly (A) having a top cross slide (A1), a bottom cross slide (A2), and a protective cover (A3), with said bottom cross slide (A2) attached to said top cross slide (A1) and moveable with respect to said top cross slide (A1), the said protective cover (A3) disposed between the said top cross slide (A1) and the said bottom cross slide (A2) and attached to the fixed angular bracket,
- wherein the said guide way assembly (B) has a first LM guide rail (B1) and a second LM guide rail (B2), onto which a corresponding first LM guide carriage (B3) and a second LM guide carriage (B4) are mounted, and the top cross slide (A1) is mounted moveably on the said first LM guide carriage (B3) and bottom cross slide (A2) is mounted moveably on the said second LM guide carriage (B4),
- wherein the said tool holder assembly (C) has a turret assembly which is connected to bottom moveable cross slide (A2),
- wherein the said drive assembly (D) has a ball screw (D1) and drive means (D2) which is attached to the said top cross slide (A1).

characterised in that the cross slide has two portions (A1,A2) disposed on top and bottom with a fixed protective cover (A3) disposed therein-between, and the bottom portion (A2) moveable with respect to top portion (A1) and protective cover (A3).

3. A lathe comprising of cross slide assembly as claimed in claim 1.

4. A lathe comprising of cross slide assembly as claimed in claim 2. , Description:FIELD OF INVENTION :

The disclosure relates to a lathe machine and more specifically to a horizontal lathe machine having an angular slanted X axis with a main spindle and having at least one sub spindle.

The invention relates to a novel chip and coolant protection solution offered for these lathes on the X axis slide and more particularly to a lathe with a sub spindle having an arrangement of telescopic hood in existing lathes.

PRIOR ART AND BACKGROUND :

A conventional horizontal lathe machine with angular slanted X axis with two spindles such as main spindle and sub spindle are well known in prior art.

In a lathe, which is a machine for chipping and shaping articles of wood, metal, etc, wherein the said workpiece is held and turned rapidly at highspeed against a cutting tool, chips are formed during such a machining operation and fall onto the cross slider’s guide ways with moving and non moving parts in the proximity. Hence, in prior art, telescopic cover was introduced, but which telescopic cover in its retracted state interferes and hinders the operation of the sub spindle. If sub spindle headstock housing is mounted horizontally and aligned Inline with the main spindle to keep the cost low.

There are many suggestions in prior art patents in designing different types of hoods and covers which are typically telescopic in nature or otherwise. Most preferred cover is ‘telescopic’ designs, as it is versatile to design and flexible in nature and which can be deployed and retracted in simple manner.

Hence the prior art continues to suffer the space constraint in the proximity of sub spindle even when the protective telescopic cover is in its retracted state.

OBJECT OF THE INVENTION :

The first object of the invention is to find an alternate to the telescopic cover known to be used with for cross slides in a lathe so that formed chips will not hinder the guide ways moving and non moving parts/portions of the cross slide.

The other object of the invention is to eliminate the protective telescopic cover which demands a large length beyond the length of the cross slide.

The other object of the invention is to attempt to reduce the length of the cross slider and incorporate the protective cover integral with the cross slider.

The above and other objects, feature and advantages of the invention will become apparent from the detail description given herein with accompanying drawings.

SUMMARY OF THE INVENTION :

The above described disadvantages of the prior art with respect to telescopic cover for cross slide are overcome by this invention by inserting fastening a protective cover into a slot which exists between to a double layered two-portion cross slide. The double layer and two portion cross slide shortens the overall length of cross slide to the extent of nesting of telescopic protection cover beyond the actual length of the crossslide, thereby providing space for attaching a protective cover which is fixed in nature. In all prior art, the telescopic cover is retracted and deployed with respect to cross slide but in this invention cover is fixed and one portion of cross slide itself is adapted to extend and retract with respect to the fixed cover and the other cross slide portion to achieve the purpose and object of invention.

DESCRIPTION WITH RESPECT TO DRAWINGS :

Fig. 1 and 2 – Assembly overview of the invention and the conventional method – the left-hand side drawing illustrating the new innovative method of protecting LM guide and ballscrew using fixed stainless steel cover and right-hand side drawing illustrating the conventional method using telescopic cover.
Fig. 3 and 4 – The protection cover arrangement illustrated in conventional method and as per the invention – the top drawings illustrating the conventional guideway protection using telescopic cover needs more length thereby occupies more space for compression and elongation of telescopic cover and the lower drawing illustrating the innovative guideway protection with two piece slide construction with a hollow slot between top slide and bottom slide enables to fix a stainless steel cover which does not move thereby occupies less space.
Fig. 5 and 6 – Illustration of protrusion length in conventional method and innovative method – top drawing illustrating conventional method and bottom drawing illustrating the new innovative method.
Fig. 7 – Broken out view of the new innovative design
Fig. 8 – conceptual view of the innovative method with two piece with hollow slot to enable fixed stainless steel cover to protect LM guide way and ballscrew from chips and coolant.
Fig. 9 – illustration of x-axis assembly
Fig. 10 - illustration of tool holder assembly.
Fig. 11 – the comparison of advantages of innovative method with respect to conventional method.
Fig. 12 – Exploded view of the design.

DESCRIPTION OF THE INVENTION :

The present invention can be used with various lathes and is not limited to just turret lathe having a main spindle and sub spindle. As will be apparent from the following description, the novel cross slider has been designed with a built-in fixed protective cover with an aim to enable sub spindle operation effectively. But the same design and concept can be used and utilised in various lathes or other machine tools in various slides when there is a space constraint for the simple reason that one can avoid the usage of telescopic protective cover, which has inherent nesting storage space demand disadvantageously.

As per this invention, to protect the non-driving portions of the cross slide, the cross slide advantageously covers the narrow portion between the main spindle and turret completely with a fixed cover attached to the cross slide itself.

For simple understanding of various components that comprise a typical lathe, a fuller understanding of the state of art of known lathes is given herein.

Lathes are designed to rotate a workpiece against a tool bit. The workpiece rotates against a stationery tool bit to remove a portion from a workpiece to give it a desired shape and size. Hence it is obvious chips are scattered during the operation of the lathe.

A NC automatic lathe is used for holding a workpiece securely and rigidly and turning it against cutting tools which remove undesired portions off from the workpiece in the form of chips. In a lathe with main spindle and sub spindle, main spindle holds the work first for machining and then sub spindle grabs the work before cut off and holds it for subsequent machining.

So when there are more than one main spindle, programmable cross slides are advantageously exploited, which are mounted proximate to the main spindle and turret tool post with mounted tools. Hence in such an arrangement, it becomes possible to engage more than one tool while the work is engaged in main spindle and then cut it off and move it to sub spindle and then engage more than one tools at this end also.

Slant bed lathe typically at 30°C-45°C is popular. The slant bed lathe has advantage i.e., more effective in chip evacuation and chips can be easily washed into a chip conveyor/tray/disperser. Also slant bed lathe have longer x-axis travel than a flat bed lathe with same foot print.

Bed/base is a horizontal structure/beam and is the base for the working parts of the lathe. The main feature of the bed is in its “ways” formed on its upper surface and which typically extend along the full length of the lathe. These ways are accurately machined parallel to the axis of the main spindle (mounted on the base) and to each other. The head stock carrying the main spindle is permanently fixed at one end but the tail stock and carriage slide on the “ways” in parallel alignment with the head stock.

Head stock is a robust portion and arranged on one end of the bed/base. Once bolted/clamped to the end, the head stock is used to give rotational power to rotate the workpiece against the stationery tool bit. The head stock carries the head/main spindle and mechanisms for driving it such as speed change mechanism, change gears, etc.

Tail stock is arranged on the other distal end of the bed/base. Once clamped to that distal end, it is like a non-rotating barrel/cylinder body used to hold tool bits and for supporting workpieces while they turn/rotate.

The purpose of tail stock is to hold the dead centre to support one end of the work being machined between centers. The tail stock moves along the “ways” along the length of the bed/base to accommodate work of varying lengths. It can be clamped/bolted in the desired portion by tail stock clamping nut/bolting nut.

The tail stock is thus a tool (drill) and a centre mount, opposite the main spindle. This tail stock sub spindle does not rotate but travels longitudinally under the action of lead screw. Hence tail stock is different from the head stock and sub spindle is very different from the main spindle.

Lathe Centres

The workpiece is supported between two centres, one in the head stock spindle and one in the tail stock spindle/sub spindle.

Main Spindle holds and drives the workpiece and is arranged on the head stock side of the lathe.

The first machining operation is performed in the workpiece chucked by main spindle and then chucked by the sub spindle. The head stock main spindle is the main rotating element of the lathe and is directly connected to the workpiece which revolves with it.

Chucks chuck is mounted on the spindle. The workpiece is held to main spindle with chuck, which chuck exerts pressure on the workpiece to hold it secure to the sub spindle.

The main spindle is generally hollow and long bar to extend through to the work area.

The main spindle runs in precision bearings and is fitted with chucks i.e., means for attaching to the workpiece. The motion of workpiece is rotation about spindle axis and tool is fed against the revolving workpiece. The movement of tool can be parallel to or at any inclination to the workpiece axis. With main spindle configuration lathe, a workpiece can be completed from one end only.

Sub spindle is arranged on the tail stock side of the lathe and opposed to the main spindle such that it can move towards and away and also in angular directional to main spindle, with respect to longitudinal axis of lathe. A number of back machining tool means are arranged in this side, which is done without increasing the dimension of lathe in direction of depth and height, and whereby complex and diversified rear backend machining can be conducted and consequently much machining time is reduced. The first machining operation is done on the workpiece chucked by main spindle and then chucked by sub spindle.

Chucks The “workpiece” is held to sub spindle with chucks, which chuck exerts pressure on the workpiece to hold it secure to the main spindle.

Unlike single main spindle lathe in which work can be completed from one end only, a lathe with sub spindle provides the ability to machine to operate at different angles of the workpiece, without handling it i.e., sub spindle grabs the workpiece before cut off and holds it for subsequent machining.

With the main spindle and sub spindle arrangement, and turning centres being coaxial, the two spindles are facing each other and the variance can be that power of sub spindle may be same or different from power of main spindle but generally sub spindle has less cutting capacity than main spindle.

The main spindle generally holds and rotates the workpiece while the front/first end of the workpiece is machined by tools in a turret. Then the sub spindle picks up the workpiece from the main spindle to rotate the workpiece while the rear/second end of the workpiece is machined, usually by tools in the same turret. Hence sub spindle turning are very useful for machining workpiece in which both ends to be machined.

Sub spindle

The sub spindle grabs the workpiece for machining on its back side to complete the workpiece in one step.

Z axis slide Carriage is arranged displacebly on the bed/base and is nestled between the head stock at one end and tail stock/subspindle at other end. The carriage is necessary to guide the tool bit as it cuts the workpiece.

This Z axis slide carriage can provide provides longitudinal movements of cutting tools parallel to the main spindle various movements to cutting tools. It can assist the longitudinal feed (parallel to the axis of the workpiece) movement and also cross feed (perpendicular to the axis of workpiece).

Z axis slide Carriage carries the angular bracket on which the X axis cross feed slide and the compound rest which in turn carries the cutting tool on the tool post or turret in the tool post. The carriage can slide on the “ways” along the bed/base. The compound rest is mounted on top of cross feed slide. The X axis cross slide could also have carriage has slots/holes for clamping “workpiece” for operation. When the X axis cross slide is mounted and clamped with a work piece The Z axis slide carriage movement feeds the work to the cutting tool which is revolved by the head stock spindle.

As detailed above, the angular bracket thus enables tilting of the X axis cross slide to an inclination angle of 35degress in respect to the Z – axis slider which sits horizontally. Angular bracket is mounted on the Z axis slider in the bottom side. The top side of the angular bracket is mounted with linear motion guide rails for the X axis cross slide. The linear motion rails are fixed to angular bracket and has on it four linear motion carriages which slide on the rails which is called lm guide & rail assembly. The X axis cross slide is mounted on the linear motion carriages.

X axis Cross slide allows the tool bit to slide back and forth. The cross slide allows for the tool to travel 90° to the bed/base of the lathe and perpendicular to the main spindle.

The cross slide rides on the carriage and has a feed screw which travels at right angles to the main spindle axis and enabling facing and depth of cuts adjustments to the workpiece.

Hence the cross slide mounted on the carriage primary functions to provide cross feed of the tool and its movement is perpendicular to the centre of the lathe machine.

Tool post moves in x and z direction is for providing x and y axis, the tool post is mounted on comprises a cross slide assembly including a first slide moveable in x-direction at 90 degrees / perpendicular to the main spindle and a second slide moveable in y z-direction parallel to the main spindle and the tool past can be moved simultaneously or one after another in any direction within the plane of x and y z directions in case of a traditional CNC lathe with 2 axis & a tailstock, or X, Y & Z directions in case of a Millturn center with 3-Axis for linear movement plus a rotary axis for spindles perpendicularly to the longitudinal axis of the turret body and perpendicular to the respective axis of the respective workpiece spindle.

Tool post is a turret mounted on the X axis slide carriage and said turret holding a variety of tools or a turret which has access to a tool magazine

Physical proximity of main spindle and sub spindle

Since the two spindles i.e., main spindle and sub spindle are synchronised spindles for operation, there is a need to ensure that ‘no’ physical hindering component is very proximate to the sub spindle.

In prior art, it is identified that telescopic cover on the cross slide is a hindering component interfering with the efficient operation of the spindle.

Telescopic cover

In a lathe machine tool, cover is required to be associated with slider so that drive unit is protected from chips and cutting fluids and thereby telescopic cover is used which is flexibly connected to the cross slide. There is a suffering of space in retracted/deployed state of telescopic cover due to its physical proximity to the slider and so too its proximity to main spindle and sub spindle.

A telescopic cover has a plurality of shield/plate elements which engage with one another and slide within one another telescopically. As much as telescopic cover can extend and contract, it essentially suffers a disadvantage of that at least some portion/zone is required to be occupied around the slider proximity even when the telescopic cover is not in use and in collapsed closed state. Hence as much as telescopic cover is useful and essential in its fully deployed condition, its existence in retracted or nested condition is a disadvantageous suffering, more so when this protective cover of slider is very proximate to main spindle/sub spindle.

Irrespective of the telescopic cover different shapes and different profiles, the suffering in its retracted/nested condition cannot be overcome when it is used in a lathe machine. But it is necessary to have a “cover” to protect the non moving and moving portions of the guide way and “drive mechanism of the “slide” surface, away from the chip and cutting fluid during lathe operation. But the suffering of “nesting side” of telescopic cover occupying space so hinders the operation of lathe and hence not desirable, but it cannot be eliminated as a cover is very essential which cover needs to seal the narrow portion between the head stock and turret from the scattering the chips and cutting fluids, etc. In a turret lathe, the tool on the turret part moves to the vicinity of the centre of rotation of the workpiece, which means there is a need to move the turret post to a position very close to the main spindle of head stock and a covers becomes almost mandatory for sealing the narrow portion between the head stock and turret to protect the non-machining area of the sliding guide drive. The telescopic covers are hence very commonly and largely used for chip protection for cross slides in all of the known prior art.

Having explained the state of art and its suffering of telescopic cover the improvements offered by this invention overcomes all the drawbacks of the prior art.

The lathe as per invention has a novel composite cross slide assembly.

In one aspect the composite cross slide assembly of the lathe having a slide carriage along z-axis comprises of :
- cross slide with drive assembly which has two portions, with a top portion having an interior to accommodate a bottom portion displacebly therewithin, which bottom portion is moveable from its retracted state outwardly relative to top portion to its deployed state and a fixed protective cover attached to the fixing plate which is mounted on the angular bracket which does not move, edge of the top portion extending outwardly beyond the edge of the top portion to encase the displaced bottom portion therewithin itself when the bottom slide portion is in its deployed state,
- the said arrangement is novel in that the slide is partitioned into two portions with bottom portion moveable with respect to top portion and the slide moveable with respect to fixed protective cover. In prior art, cross slide is a unitary means and never partitioned. In this invention, the cross slide is partitioned into top and bottom portion. In prior art, the protective cover moves with respect to slider but in this slider moves with respect to cover. Both these features are novel and new.

In second aspect, the cross slide assembly of lathe machine having a slide carriage along z-axis detailed above further comprises of:
a. x axis cross slide assembly (A) (A1-A2),
b. LM guide & Rail assembly (B) (B1-B2-B3-B4),
c. Tool Holder Assembly / Turret Assembly (C)
d. Ball Screw& Drive Assembly (D) (D1-D2),
e. wherein the said x axis cross slide assembly (A) is mounted on a fixed angular bracket which bracket is fixed on the slide carriage, and the said cross slide assembly (A) has a top cross slide (A1) attached with a ball screw &drive assembly(D), a bottom cross slide (A2)attached to top cross slide (A1) and movable with respect to top cross slide (A1), and a protective cover portion (A3) disposed between the top cross slide (A1) and a bottom cross slide (A2) and also fixed to the angular bracket;
wherein the bottom cross slide (A2) and top cross slide (A1) are connected to each other so that it moves together;
f. wherein the LM guide & Rail assembly (B) has a first LM guide rail (B1) & a second LM guide rail (B2) for supporting the guide way assembly (B) such that the top cross slide (A1) connected to Ball screw & drive assembly (D) with driving mechanism mounted on LM guide carriages(B3) is moveable along the guide rail (B1&B2) which also moves the bottom cross slide (A2) mounted on another set of LM guide carriage(B4) is moveable along the LM guide rail (B1&B2) with respect to top cross slide(A1) with a ball screw &drive assembly(D) with a driving mechanism wherein the tool holder assembly / turret assembly(C) is connected to the bottom moveable cross slide which is connected to the top cross slide with a Ball screw & drive assembly(D) which has a drive mechanism.

the said arrangement is novel in that the cross slide is divided into two portions with a fixed integral protective cover sandwiched between the top and bottom portion of the cross slide and further the cross slide moves relative to the protective cover.

In third aspect the invention is for a lathe comprising of cross slide assembly as detailed in first aspect.

In fourth aspect the invention is for a lathe comprising of cross slide assembly as detailed in the second aspect.

Owing to the arrangement as disclosed and represented, it is to be noted the width and height of bottom portion of the cross slide is slightly less than the width and height of top cross slide, so that the bottom portion can enter into the interior of the top portion of the cross slide when it is in its retracted state. Accordingly the width and height of bottom portion of the cross slide is slightly less than the width and height of the protective cover also so that the bottom portion can enter into the interior of the protective cover when it is in deployed state and moved outwardly beyond and out of top portion of the cross slide.

The various features of novelty which characterises the invention are pointed out with particularly in claims annexed to and forming a part of this specification. The operating advantages and specific objects obtained by its use are putforth in descriptive matter and illustrations annexed herein.