Specification
FORM 2
The Patents Act 1970
(39 of 1970)
&
The Patent Rules 2003
COMPLETE SPECIFICATION
(See Section 10 and rule 13) TITLE OF THE INVENTION:
WIRECUT BED ASSEMBLY WITH MULTIHOLDER
APPLICANT:
LARSEN & TOUBRO LIMITED
L&T House, Ballard Estate, P.O. Box No. 278,
Mumbai, 400 001, Maharashtra .
INDIA.
PREAMBLE OF THE DESCRIPTION:
THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED
A) TECHNICAL FIELD
[0001] The present invention generally relates to work holding devices and more particularly to a wire cut multi holder which can be used as a common reference for holding work pieces or job of irregular surfaces.
B) BACKGROUND OF THE INVENTION
[0002] Wire cut operation is a manufacturing operation in which a thin wire, with a current flowing through it is passed through the workpiece. When the current is passed through the workpiece both the wire and the work piece or job are in the electrical circuit. Usually a small gap is provided between the workpiece and the wire, this gap for which the current flows is called as spark gap. When a potential difference is achieved between the workpiece, which is cathode and wire which is anode, a spark flies from the wire bombards the surface of the workpiece and erodes the material from its surface, such continuous bombardment on the surface of the workpiece causes a cut with a very close tolerance. The path for the wire movement can be controlled and any desired shape can be achieved.
[0003] Wire-cut machine has an open bed. Various work holding devices are used for clamping the job on the machine bed. The wire-cut operation can be done by conventional work holding devices such parallel clamps, toolmakers clamps, V-Block
and collets for round jobs. Mounting the job through this conventional means is having certain disadvantages.
[0004] There are various methods for holding the workpiece on to the wire cut bed. The conventional methods available uses V block and tool makers clamp as a work holding device. The V block is a commonly used work holding device, it consists of a V grove on which a round job is placed the tangential contact of the two V faces self locate the round job on the V block. The wire of the wire cut machine touches the tow highest points on the round job and fixes the mid axis. After touching the outermost face, the extreme reference can be fixed and program can be run in accordance. The major problem with this work holding device is no self referencing system is available. The referencing procedure has to be repeated for every piece. More over since, the V Block is mounted on the machine bed the workpiece is to be machined at both ends for two settings. And the rectangular jobs cannot be held using this method.
[0005] The toolmakers clamp are used for holding the flat jobs on the wire cut machine , one half of the inserts are placed on the bed and clamped on the bed and the remaining portion of the job which is at the open end of the bed can be machined. In this case if any tooling hole that is any accurately finished hole if present can be used as a reference hole while in other cases touching the highest point at the outermost edge can be used for referencing. In this method other half on the bed cannot be used for machining. Using dial's for checking the parallity of the workpiece is a must and is a very time consuming activity. It is not suitable for holding round jobs.
[0006] Hence there is a need to provide a work holding device or a tool maker's clamp, which can be used for clamping round as well as rectangular jobs. Hence there is a need to eliminate the aligment and referencing problems that was faced during clamping.
C) OBJECTS OF THE INVENTION
[0007] The primary object of the present invention is to provide a wirecut multiholding device which can be used as an alignment cum referencing device for round as well as rectangular job.
[0008] Another object of the present invention is to provide a wirecut multiholder which can be used as a common reference and the jobs can be machined using the same reference.
[0009] Yet another object of the present invention is to provide a wire cut multiholder which can be used for machining both side of the round job at same time.
[0010] Yet another object of the present invention is to provide a wire cut multiholder using which both the plane and the top view cutting of the job or work piece is possible.
[0011] Yet another object of the present invention is to provide a wire cut multiholder using which the clamping and the alignment becomes very simple for round as well as rectangular jobs.
[0012] These and other objects and advantages of the present invention will become readily apparent from the following detailed description taken in conjunction with the accompanying drawings.
D) SUMMARY OF THE INVENTION
[0013] The above mentioned shortcomings, disadvantages and problems are addressed herein and which will be understood by reading and studying the following specification.
[0014] The various embodiments of the present invention provide a wirecut multiholder to hold the workpiece or jobs of round as well as rectangular shape. It provides a common reference point and the jobs can be machined using the same reference. Both sides of the round job can be machined at a time using the multiholder. Both plane and top view cutting can be done using the same device.
[0015] According to one embodiment of the present invention, a wire cut bed assembly for jobs with multiple shapes has a base support frame provided with a rectangular recess at the centre. A first lead screw and a second lead screw are mounted on the mutually orthogonal side surfaces of the base support frame for holding rectangular jobs. A third
lead screw and a fourth lead screw are provided one below the other in the same corner of the base support frame for holding circular jobs. A first set of grooves and the second set of grooves are formed on the mutually orthogonal side surface of the base support frame. A first job clamping thread is formed near the first set of grooves. A second job clamping thread is formed near the second set of grooves. Two spacers are removably provided on the first set of grooves and the second set of grooves. The base support frame is used to hold job of different shapes.
[0016] The rectangular recess is provided at the centre of the base support frame for holding the jobs of different shapes. The third lead screw and the fourth lead screw are formed on the same corner arranged between the orthogonal side surfaces provided with the first lead screw and the second lead screw. The set of grooves are V-shaped grooves with an angle of 120 degrees. The second set of grooves is V-shaped grooves with an angle of 90 degrees. The first set of grooves and the second set of grooves are used to hold jobs to perform machining at both ends of the job simultaneously. The spacers are provided on the grooves to carry out machining on the collared jobs.
[0017] According to one embodiment of the present invention, a reference hole or datum hole is used to take the reference that is the first position of the fixture and the job mounted on the fixture. The wire of the wirecut machine is touched on the four sides of the accurately made hole and the reference is taken.
[0018] According to embodiment of the present invention, two right angled faces 2 are provided for holding rectangular jobs. The job is butt on the two right angled faces to achieve accurate/ true positioning of the job on the fixture. These features are accurately
made by wirecut operation and are checked for the accuracy through inspection. The two cross lead screws 3 are used for holding round jobs on to the fixture. They are placed opposite to the angled face for accurate holding of round job against the right angular faces. The side lead screws 4 and 5 provided for holding the rectangular jobs on to the fixture, each screw holds the job accurately against one of the right angular face. A 120° V grove 6 is provided to hold round Jobs up to 100 Diameter, it is an open V grove and the job can be cut at its both extreme ends. A 90° V Grove 7 holds round Jobs up to 50 Diameter, it is an open V grove and the job can be cut at its both extreme ends. The bed clamp screw 8 is provided to mount the multi holder or fixture on the wire cut bed. A Job clamping thread 9 with 120° V grove and a job clamping thread 10 with 90° V grove are provided to hold the round job securely on to the fixture. The V spacers 11 and 12 are used for round job or workpiece having collars that is diametric variant jobs where the larger diameter interferes in the holding of the job on the V grove.
[0019] According to embodiment of the present invention, when the job is held on the
right angular face, the wire alignment is taken from the reference hole which is at 5mm
from both faces and the following calculation is applied
JOB CENTER = 5mm + HALF JOB DIAMETER
Once the job center is reached the wirecut program can be run from the Job center.
[0020] According to embodiment of the present invention, when the job is held in the right angular face using lead screw a wire alignment is taken from the reference hole which is at 5mm from both faces and the following calculation is applied JOB CENTER = 5mm + half width of rectangular job (distance form right angular face)
The length reading can be taken by simply touching the wire on the outermost edge of the face. Once the job center is reached the wirecut program can be run from the Job center.
[0021] According to embodiment of the present invention, when the rectangular job is held in the right angular face using lead screw a wire alignment is taken from the reference hole which is at 5mm from both faces and the following calculation is applied JOB CENTER = 5mm + half width of rectangular job (distance form right angular face) The length reading can be taken by simply touching the wire on the outermost edge of the face. Once the job center is reached the wirecut program can be run from the Job center.
[0022] According to one embodiment of the present invention, when the collared round
job is held in V groove spacers the wire alignment is taken from the reference hole which
is at 5mm from both faces and the following calculation is applied
JOB CENTER = 5mm + HALF JOB DIAMETER
The length reading can be taken by simply touching the wire on the outermost edge of the
face. Once the job center is reached the wirecut program can be run from the Job center.
E) BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The other objects, features and advantages will occur to those skilled in the art from the following description of the preferred embodiment and the accompanying drawings in which:
[0024] FIG. 1 shows a top perspective view of the wirecut multiholder held on the wire cut bed with screws according to one embodiment of the present invention.
[0025] FIG. 2 shows a top view of the wirecut multiholder according to one embodiment of the present invention-
[0026] FIG. 3 shows a top perspective view of the wirecut multiholder with round job held on fixture with cross lead screws according to one embodiment of the present invention,
[0027] FIG. 4 shows a top perspective view of the wirecut multiholder with round job held on the 120° V grove and clamped with strap clamp according to one embodiment of the present invention.
[0028] FIG. 5 shows a top perspective view of the wirecut multiholder with rectangular job held on the work holding device according to one embodiment of the present
invention.
[0029] FIG. 6 shows a top perspective view of the wirecut multiholder with collared
round job held in V groove spacers according to one embodiment of the present
invention.
[0030] Although specific features of the present invention are shown in some drawings and not in others. This is done for convenience only as each feature may be combined with any or all of the other features in accordance with the present invention.
F) DETAILED DESCRIPTION OF THE INVENTION
[0031] In the following detailed description, reference is made to the accompanying drawings that form a part hereof, and in which the specific embodiments that may be practiced is shown by way of illustration. These embodiments are described in sufficient detail to enable those skilled in the art to practice the embodiments and it is to be understood that the logical, mechanical and other changes may be made without departing from the scope of the embodiments. The following detailed description is therefore not to be taken in a limiting sense.
[0032] The various embodiments of the present invention provide a wirecut multiholder to hold the workpiece or jobs of round as well as rectangular shape. It provides a common reference point and the jobs can be machined using the same reference. Both sides of the round job can be machined at a time using the multiholder. Both plane and top view cutting can be done using the same device. Reference hole or datum hole is used to take the reference that is the first position of the fixture and the Job mounted on the fixture. The wire of the wirecut machine is touched on the four sides of the accurately made hole and the reference is taken.
[0033] According to one embodiment of the present invention, a wire cut bed assembly for jobs with multiple shapes has a base support frame provided with a rectangular recess at the centre. A first lead screw and a second lead screw are mounted on the mutually
orthogonal side surfaces of the base support frame for holding rectangular jobs. A third lead screw and a fourth lead screw are provided one below the other in the same corner of the base support frame for holding circular jobs. A first set of grooves and the second set of grooves are formed on the mutually orthogonal side surface of the base support frame. A first job clamping thread is formed near the first set of grooves. A second job clamping thread is formed near the second set of grooves. Two spacers are removably provided on the first set of grooves and the second set of grooves. The base support frame is used to holdjob of different shapes.
[0034] The rectangular recess is provided at the centre of the base support frame for holding the jobs of different shapes. The third lead screw and the fourth lead screw are formed on the same corner arranged between the orthogonal side surfaces provided with the first lead screw and the second lead screw. The set of grooves are V-shaped grooves with an angle of 120 degrees. The second set of grooves are V-shaped grooves with an angle of 90 degrees. The first set of grooves and the second set of grooves are used to hold jobs to perform machining at both ends of the job simultaneously. The spacers are provided on the grooves to carry out machining on the collared jobs.
[0035] FIG. 1 shows a top perspective view of the wirecut multiholder held on the wire cut bed with screws according to one embodiment of the present invention. The reference hole or datum hole 101 is used to take the reference that is the first position of the multiholder and the job to be held on the multiholder. The wire of the wirecut machine is touched on the four sides of the accurately made hole and the reference is taken. The two
right angled faces 102 are provided for holding rectangular jobs. The job is Butt on the two right angled faces to achieve accurate/ true positioning of the job on the fixture. These features are accurately made by wirecut operation and are checked for the accuracy through inspection. The two cross lead Screws 103 is provided to hold the round jobs on to the fixture. They are placed opposite to the angled face for accurate holding of round job against the right angular faces. The side lead Screw 104 and 105 provided for holding the rectangular jobs on to the fixture, each screw holds the job accurately against one of the right angular face. A 120° V Grove 106 is provided to hold round jobs up to 100 diameters, it is an open V grove and the job can be cut at its both extreme ends. A 90° V Grove 107 holds round jobs up to 50 Diameter, it is an open V grove and the job can be cut at its both extreme ends. The bed clamp screw 108 is provided to mount the multi holder or fixture on the wire cut bed. A job clamping thread 109 with 120° V Grove and a job clamping thread 110 with 90° V grove are provided to hold the round job securely on to the fixture. The V Spacers 111 and 112 are used for round job or workpiece having collars i.e diametric variant jobs where the larger diameter interferes in the holding of the job on the V grove.
[0036] FIG. 2 shows a top view of the wirecut multiholder according to one embodiment of the present invention. As shown in figure, the wirecut multiholder is designed to hold the workpiece or jobs of round as well as rectangular shape. It can be used as a common reference for holding jobs and machining using same reference. Both sides of the round job can be machined at a time using the multiholder. Both plane and top view cutting can be done using the same device. Reference hole or datum hole 101 is provided to take the
reference that is the first position of the fixture and the job mounted on the fixture. The wire of the wirecut machine is touched on the four sides of the accurately made hole and the reference is taken. The two cross lead Screws 103 is provided to hold the round jobs on to the fixture. They are placed opposite to the angled face for accurate holding of round job against the right angular faces. A 120° V Grove 106 is provided to hold round jobs up to 100 diameters, it is an open V grove and the job can be cut at its both extreme ends. A 90° V grove 107 holds round Jobs up to 50 Diameter, it is an open V grove and the job can be cut at its both extreme ends. The V Spacers 111 and 112 are used for round job or workpiece having collars that is diametric variant jobs where the larger diameter interferes in the holding of the job on the V grove.
[0037] FIG. 3 shows a top perspective view of the wirecut multiholder with round job
301 held on fixture with cross lead screws 103 according to one embodiment of the
present invention. With respect to figure 3, the round job 301 is held between the right
angular face 102. Once the job is held on the right angular face, the wire alignment is
taken from the reference hole 101 which is at 5mm from both faces and the following
calculation is applied
JOB CENTER - 5mm + HALF JOB DIAMETER
Once the job center is reached the wirecut program can be run from the Job center.
[0038] FIG. 4 shows a top perspective view of the wirecut multiholder with round job 401 held on the 120° V grove 106 and clamped with strap clamp according to one embodiment of the present invention. With respect to figure 4, once the job is held in the
V grove 106, the wire alignment is taken from the reference hole 101 which is at 5mm
from both faces and the following calculation is applied
JOB CENTER = 5mm + 50mm (distance from the right angular face)
The length reading can be taken by simply touching the wire on the outermost edge of the
face. Once the job center is reached the wirecut program can be run from the job center.
A maximum diameter of 100 DIA round job can be held with side clamping as shown in
figure 4.
[0039] FIG. 5 shows a top perspective view of the wirecut multiholder with rectangular job 501 held on the holder or work holding device according to one embodiment of the present invention. It shows a square job 501 held on the right angled side wall 102 with the side lead screws 104 and 105, the same referencing hole can be used for taking wire reference and cutting the job. Once the job is held in the right angular face using lead screw a wire alignment is taken from the reference hole which is at 5mm from both faces and the following calculation is applied
JOB CENTER = 5mm + half width of rectangular job (distance form right angular face) The length reading can be taken by simply touching the wire on the outermost edge of the face. Once the job center is reached the wirecut program can be run from the Job center.
[0040] FIG. 6 shows a top perspective view of the wirecut multiholder with collared round job held in V groove spacers according to one embodiment of the present invention. After the job is held in the V grove using V spacers as shown in figure 6, the
wire alignment is taken from the reference hole which is at 5mm from both faces and the
following calculation is applied
JOB CENTER - 5mm + HALF JOB DIAMETER
The length reading can be taken by simply touching the wire on the outermost edge of the
face. Once the job center is reached the wirecut program can be run from the Job center.
G) ADVANTAGES OF THE INVENTION
[0041] The various embodiments of the present invention provide a wirecut multiholder to hold the workpiece or jobs of round as well as rectangular shape. It provides a common reference point and the jobs can be machined using the same reference. Both sides of the round job can be machined at a time using the multiholder. Both plane and top view cutting can be done using the same device. Reference hole or datum hole is used to take the reference i.e the first position of the fixture and the Job mounted on the fixture. The wire of the wirecut machine is touched on the four sides of the accurately made hole and the reference is taken.
[0042] Although the invention is described with various specific embodiments, it will be obvious for a person skilled in the art to practice the invention with modifications. However, all such modifications are deemed to be within the scope of the claims.
[0043] It is also to be understood that the following claims are intended to cover all of the generic and specific features of the present invention described herein and all the
statements of the scope of the invention which as a matter of language might be said to fall there between.
Date: March 30, 2009 RAKESH PRABHU
Place: Bangalore. Patent Agent
CLAIMS
What is claimed is:
1. A wire cut bed assembly for jobs with multiple shapes comprising: a base support frame;
a rectangular recess provided at the centre of the base support frame; a first lead screw mounted on one side surface of the base support frame for holding rectangular jobs;
a second lead screw mounted on one side surface of the base support frame for holding rectangular jobs;
a third lead screw provided at one corner of the base support frame for holding circular jobs;
a fourth lead screw provided at one corner of the base support frame for holding circular jobs;
a first set of grooves formed on one side surface of the base support frame; a second set of grooves formed on one side surface of the base support frame; a first job clamping thread formed near the first set of grooves; a second job clamping thread formed near the second set of grooves; and two spacers removably provided on the first set of grooves and the second set of grooves; wherein the base support frame is used to hold job of different shapes.
2. The assembly according to claim 1, wherein the rectangular recess is provided at the centre of the base support frame for holding the jobs of different shapes.
3. The assembly according to claim 1, wherein the first lead screw and the second lead screw are formed respectively on the mutually orthogonal side surfaces.
4. The assembly according to claim 1, wherein the third lead screw and the fourth lead screw are formed one below the another on the same corner.
5. The assembly according to claim 1, wherein the third lead screw and the fourth lead screw are formed on the same corner arranged between the orthogonal side surfaces provided with the First lead screw and the second lead screw.
6. The assembly according to claim 1, wherein the first set of grooves and the second set of grooves are formed one the side surfaces which are mutually orthogonal.
7. The assembly according to claim 1, wherein the first set of grooves are V-shaped grooves with an angle of 120 degrees.
8. The assembly according to claim 1, wherein the second set of grooves are V-shaped grooves with an angle of 90 degrees.
9. The assembly according to claim 1, wherein the first set of grooves and the second set of grooves are used to hold jobs to perform machining at both ends of the job simultaneously.
10. The assembly according to claim 1, wherein the spacers are provide on the grooves to carry out machining on the collared jobs.
Dated this the 30th day of March 2009
RAKESH PRABHU Patent Agent,
ALMT Legal,
#2, Lavelle Road, Bangalore-560 001
To,
The Controller of Patents, The Patent office, Mumbai
