Title of Invention	IMPROVED SLIDING UNIT FOR LINEAR BORING OPERATION IN AN ENGINE BLOCK
Abstract	This invention relates to an enveloping guideway for machine tools, especially for special purpose machines. A combination of three LM guideways, are arranged enveloping the spindle unit. With this arrangement, the machining accuracy obtained is of higher degree due to better alignment conditions and the ability to avoid deflections. Also, the elimination of overhang of spindle 4 from the guideway results in better surface finish on the component.

Title of Invention

IMPROVED SLIDING UNIT FOR LINEAR BORING OPERATION IN AN ENGINE BLOCK

Abstract

This invention relates to an enveloping guideway for machine tools, especially for special purpose machines. A combination of three LM guideways, are arranged enveloping the spindle unit. With this arrangement, the machining accuracy obtained is of higher degree due to better alignment conditions and the ability to avoid deflections. Also, the elimination of overhang of spindle 4 from the guideway results in better surface finish on the component.

Full Text	FIELD OF THE INVENTION This invention relates to an improved sliding unit for linear boring operation in an engine block including an enveloping linear motion guideway. The said unit is for use in machine tools, especially for special purpose machines. BACKGROUND Guideways in the area of machine tools are a critical area of design while determining the rigidity of the machine, accuracy on component machined, feed and rapid travel rates allowed, machine life etc. The guideway size, form and arrangements largely depend on machining and structural loads placed directly on them. Prismatic guideways in dovetail or rectangular forms are commonly being used in machine tools. The limitation of using such guideways for higher rate of slide motions leads to the choice of linear motion guideways (L.M. guideways). However, the positioning and arrangement of the guideway are all the more important in determining the machined accuracy on the component. There is also a cost aspect while determining guideway designs. The accuracy levels and the surface finish on the component by the known machines are not up to the high standards expected. DISCUSSION OF PRIOR ART: U.S. Patent No. 5,501,527 discloses a linear movement ball guideway including a slide block, a guide rail and multiple loaded and unloaded ball members. U.S. Patent No. 6,960,022 discloses a macrocomposite guideway where additional support is afforded to the conventional guideway with the support being made of lightweight material. Both these inventions are different from the current invention, whose objectives include easy assembly, increased precision and the employment of three linear motion guideways to facilitate the enveloping guideway, arranged to envelop the spindle unit with the spindle unit itself acts as the sliding unit for linear boring operation in an engine block. Accordingly, it is the primary objective of the present invention to provide an improved sliding unit with a novel enveloping guideway, which is simple and yet has better alignment conditions. SUMMARY OF THE INVENTION In comparison to a conventional guideway, the LM guideway is easier to assemble. This does not require highly skilled technicians to perform the assembly work. This will result in less man-hours for assembly and a less expensive product. A Linear Motion system has rolling elements, such as balls placed between two raceways. The rolling motion provided by the rolling elements reduces the frictional resistance to a considerable extent than that in a conventional rectangular guideway. With good lubrication, stick - slip motion also does not occur in a LM guideway. Hence higher rapid rates can be achieved. The LM guideways are mounted on a sturdy housing. The housing is machined accurately to mount the LM guideways, so that the final sliding movement accuracy is built in. Even on an imprecise mounting surface, the LM guideway can absorb the machining accuracy errors by virtue of the elastic deformation of the guide balls, thus maintaining high precision at all times. The size and type of the guideway is chosen such that the load canying capacity is adequate. The whole unit is designed as a vertical slide and spindle centerline is centralized with the enveloping guideway centerline so that any vibration due to overhang of spindle center to guideway top is minimized. The unit gets fed through ball lead screws and is driven by AC servomotor directly coupled. Advantages of New Innovative Method: With this arrangement the machining accuracy obtained is of a higher degree due to better alignment conditions and the capability to avoid deflections. Also the elimination of overhang of spindle from the guideway results in better surface finish on the component. BRIEF DESCRIPTION OF DRAWINGS Fig I. illustrates the existing/conventional guideway, and Fig 2. illustrates the novel enveloping guideway of the present invention. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Fig 1. illustrates the existing/conventional guideway. Conventionally, the guideways shown in part 1, are present on one side of the spindle unit, shown in part 2, and the slide, shown in part 3, moves in a direction parallel, across or in combination of these to the spindle axis. The offset distance between the spindle axis and the guideway is a contributing factor to rigidity, which is to be taken care of while creating the design. Fig 2. illustrates the novel enveloping guideway of the present invention. The present invention adopts an unconventional approach in introducing enveloping guideway on one of the engine block machining SPMs. In this arrangement, the spindle shown in part 4, has an axis that coincides with the enveloping guideway centerline. A combination of three LM guideways, shown in part 5, are arranged enveloping the spindle unit, shown in part 6. The spindle unit itself acts as the sliding unit for linear boring operation in engine block. WE CLAIM: 1. An improved sliding unit for linear boring operation in an engine block, comprising a spindle unit, three linear-motion guideways that are arranged to envelop the spindle unit. 2. The improved sliding unit as claimed in claim t, wherein the said unit acts as a vertical slide and spindle centerline is centralized with enveloping guideway centerline so that any vibration due to overhang of spindle center to guideway top is minimized. 3. The improved sliding unit as claimed in claim 1 or 2 wherein the spindle unit gets fed through ball lead screw and is directly coupled to an AC servomotor.

Full Text

FIELD OF THE INVENTION
This invention relates to an improved sliding unit for linear boring operation in an engine block including an enveloping linear motion guideway. The said unit is for use in machine tools, especially for special purpose machines.
BACKGROUND
Guideways in the area of machine tools are a critical area of design while determining the rigidity of the machine, accuracy on component machined, feed and rapid travel rates allowed, machine life etc. The guideway size, form and arrangements largely depend on machining and structural loads placed directly on them. Prismatic guideways in dovetail or rectangular forms are commonly being used in machine tools. The limitation of using such guideways for higher rate of slide motions leads to the choice of linear motion guideways (L.M. guideways). However, the positioning and arrangement of the guideway are all the more important in determining the machined accuracy on the component. There is also a cost aspect while determining guideway designs. The accuracy levels and the surface finish on the component by the known machines are not up to the high standards expected.
DISCUSSION OF PRIOR ART:
U.S. Patent No. 5,501,527 discloses a linear movement ball guideway including a slide block, a guide rail and multiple loaded and unloaded ball members.
U.S. Patent No. 6,960,022 discloses a macrocomposite guideway where additional support is afforded to the conventional guideway with the support being made of lightweight material.
Both these inventions are different from the current invention, whose objectives include easy assembly, increased precision and the employment of three linear motion guideways

to facilitate the enveloping guideway, arranged to envelop the spindle unit with the spindle unit itself acts as the sliding unit for linear boring operation in an engine block.
Accordingly, it is the primary objective of the present invention to provide an improved sliding unit with a novel enveloping guideway, which is simple and yet has better alignment conditions.
SUMMARY OF THE INVENTION
In comparison to a conventional guideway, the LM guideway is easier to assemble. This does not require highly skilled technicians to perform the assembly work. This will result in less man-hours for assembly and a less expensive product.
A Linear Motion system has rolling elements, such as balls placed between two raceways. The rolling motion provided by the rolling elements reduces the frictional resistance to a considerable extent than that in a conventional rectangular guideway. With good lubrication, stick - slip motion also does not occur in a LM guideway. Hence higher rapid rates can be achieved.
The LM guideways are mounted on a sturdy housing. The housing is machined accurately to mount the LM guideways, so that the final sliding movement accuracy is built in. Even on an imprecise mounting surface, the LM guideway can absorb the machining accuracy errors by virtue of the elastic deformation of the guide balls, thus maintaining high precision at all times. The size and type of the guideway is chosen such that the load canying capacity is adequate.
The whole unit is designed as a vertical slide and spindle centerline is centralized with the enveloping guideway centerline so that any vibration due to overhang of spindle center to guideway top is minimized. The unit gets fed through ball lead screws and is driven by AC servomotor directly coupled.

Advantages of New Innovative Method:
With this arrangement the machining accuracy obtained is of a higher degree due to better alignment conditions and the capability to avoid deflections. Also the elimination of overhang of spindle from the guideway results in better surface finish on the component.
BRIEF DESCRIPTION OF DRAWINGS
Fig I. illustrates the existing/conventional guideway, and
Fig 2. illustrates the novel enveloping guideway of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Fig 1. illustrates the existing/conventional guideway. Conventionally, the guideways shown in part 1, are present on one side of the spindle unit, shown in part 2, and the slide, shown in part 3, moves in a direction parallel, across or in combination of these to the spindle axis. The offset distance between the spindle axis and the guideway is a contributing factor to rigidity, which is to be taken care of while creating the design.
Fig 2. illustrates the novel enveloping guideway of the present invention. The present invention adopts an unconventional approach in introducing enveloping guideway on one of the engine block machining SPMs. In this arrangement, the spindle shown in part 4, has an axis that coincides with the enveloping guideway centerline. A combination of three LM guideways, shown in part 5, are arranged enveloping the spindle unit, shown in part 6. The spindle unit itself acts as the sliding unit for linear boring operation in engine block.

WE CLAIM:
1. An improved sliding unit for linear boring operation in an engine block,
comprising a spindle unit, three linear-motion guideways that are arranged to
envelop the spindle unit.
2. The improved sliding unit as claimed in claim t, wherein the said unit acts as a
vertical slide and spindle centerline is centralized with enveloping guideway
centerline so that any vibration due to overhang of spindle center to guideway top
is minimized.
3. The improved sliding unit as claimed in claim 1 or 2 wherein the spindle unit gets
fed through ball lead screw and is directly coupled to an AC servomotor.

Documents:

1291-che-2004 abstract duplicate.pdf

1291-che-2004 claims duplicate.pdf

1291-che-2004 description (complete) duplicate.pdf

1291-che-2004 drawings duplicate.pdf

1291-che-2004-abstract.pdf

1291-che-2004-correspondnece-others.pdf

1291-che-2004-correspondnece-po.pdf

1291-che-2004-description(provisional).pdf

1291-che-2004-drawings.pdf

1291-che-2004-form 1.pdf

1291-che-2004-form 18.pdf

1291-che-2004-form 26.pdf

1291-che-2004-form 5.pdf

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Patent Number

229358

Indian Patent Application Number

1291/CHE/2004

PG Journal Number

12/2009

Publication Date

20-Mar-2009

Grant Date

17-Feb-2009

Date of Filing

01-Dec-2004

Name of Patentee

BHARAT FRITZ WERNER LIMITED

Applicant Address

PEENYA, YESHWANTHPUR P.O., BANGALORE 560 022,

Inventors:

#	Inventor's Name	Inventor's Address
1	HARADI VASANTHA PRABHU	232/11/1, 14TH TANK B MAIN, A BLOCK, SUBRAMANYA NAGAR, BANGALORE 560 021,
2	MADIHALLI VISHWANATHASWAMY RAVISHANKAR	232, 5TH C MAIN, REMCO LAYOUT, VIJAYA NAGAR, BANGALORE 560 040,

PCT International Classification Number

B23B41/12

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA