DESC:FIELD
The present disclosure relates to the field of mechanical engineering. In particular, the present disclosure relates to the field of sine bars.
BACKGROUND
A sine bar is typically used to measure angles of various components during manufacturing. The sine bar has a precision body with two ground cylinders/rollers of equal dimensions fixed at the operative ends of the body. The body of the sine bar abuts to the surface of a workpiece whose angle is to be measured.
For abutting the sine bar to the work piece, one of the roller is raised by a known distance using gauge blocks/slip gauges which tilts the sine bar, such that an angle is formed therebetween. The gauge blocks/slip gauges are usually available in sets of specific number of blocks of varying sizes. These gauge blocks/slip gauges of varying sizes are combined in order to obtain particular height, preferably by wringing the slip gauges together. Wringing is a process of sliding slip gauges together such that air between their surfaces is removed, thereby causing the slip gauges to adhere to each other tightly. This is a time consuming process, and requires a skilled person to ensure that the wringing is done precisely, and the usage of number of gauges is kept minimal. Moreover, if a work piece has a reverse taper with respect to a machine chuck, the conventional sine bars do not always provide correct angular degree which leads to many iterations and re-checks during manufacturing process.
There is, therefore, felt a need to provide an attachment for a sine bar which reduces the complexity and time consumption in angular measurements and angular settings.

OBJECTS
Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows:
It is an object of the present disclosure to eliminate one or more problems of the prior art or to at least provide a useful alternative.
An object of the present disclosure is to provide an attachment for a sine bar.
Another objective of the present disclosure is to provide an that limit requirement of skilled labour.
One more object of the present disclosure is to provide an attachment that reduces complexity in angular measurements.
Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.
SUMMARY
The present disclosure envisages an attachment for a sine bar having at least two rollers. The attachment has a body that is defined by a first surface and a second surface. The first surface has a trapezoidal configuration. The second surface extends from an operative flat end of the first surface and is configured to securely couple the sine bar with the attachment. In one embodiment, the body has an L – shaped configuration.
The first surface has at least two sides configured opposite to each other that makes a predetermined angle with each other, thereby defining the trapezoidal configuration. In an embodiment, the predetermined angle is in the range of 5 degrees to 25 degrees.
In an embodiment, the second surface is adapted to couple the sine bar with the attachment by means of at least one fastener selected from a group consisting of nut and bolt, threaded screw, cap screw, and rivet.
In another embodiment, the second surface is adapted to couple the sine bar with the attachment by means of at least one magnet.
The attachment further includes a cover plate that is mounted on the first surface, and is configured to align the attachment with the sine bar. In an embodiment, the cover plate is mounted on said first surface by means of at least one fastener that is selected from a group consisting of nut and bolt, threaded screw, cap screw, and rivet.
BRIEF DESCRIPTION OF ACCOMPANYING DRAWING
The present disclosure will now be explained in relation to the non-limiting accompanying drawing, in which:
Figure 1 illustrates a schematic representation of a conventional sine bar with slip gauges;
Figure 2a illustrates a schematic representation of a conventional sine bar in an inoperative configuration;
Figure 2b illustrates a schematic representation of a conventional sine bar in an operative configuration;
Figure 3a illustrates a schematic representation of a workpiece with backward decreasing taper to be fitted in the machine chuck;
Figure 3b illustrates a schematic representation of a workpiece with backward increasing taper to be fitted in the machine chuck;
Figure 4 illustrates an isometric view of an attachment for a sine bar in accordance with one embodiment of the present disclosure;
Figure 5 illustrates a front view of a sine bar and the attachment of Figure 4 in accordance and with one embodiment of the present disclosure;
Figure 6a illustrates a schematic representation of a sine bar in an inoperative configuration accordance with one embodiment of the present disclosure; and
Figure 6b illustrates a schematic representation of a sine bar in an operative configuration accordance with one embodiment of the present disclosure.
LIST OF REFERENCE NUMERALS
100 – Conventional sine bar
100a, 100b – Roller
102 – Slip-gauge
104 – Surface
200 – Machine chuck
202 – Taper job / Workpiece
204 – Grinding wheel
206 – Dial
302, 304 – Workpiece
400 – Attachment
402 –Body
402a – First Surface
402b – Second Surface
402i – Flat end
404 – Cover plate
406 – Fasteners
408 – Magnet
500 – Sine bar
500a, 500b – Roller
600 – Machine chuck
602 – Taper job/workpiece
604 – Grinding spindle
DETAILED DESCRIPTION
Conventionally, a sine bar along with gauge-blocks or slip-gauges is used to measure angles of work pieces during manufacturing. Figures 1, 2a and 2b illustrate a conventional sine bar 100 in different configurations. Typically, in order to grind a work piece/ taper job 202, it is clamped to a machine chuck 200 and an arrangement so formed by clamping the workpiece 202 to the machine chuck 200 is then adjusted, so that a tapered surface of the workpiece 202 is parallel to the grinding axis of a grinding wheel 204 to obtain desired grinding. The sine bar 100 is generally used to adjust and measure the angle of the tapered surface of the workpiece 202. The sine bar 100 has a body and two rollers 100a and 100b fixed at the ends of the body. One of the roller 100a of the sine bar 100 is placed on a surface 104 and the other roller 100b is placed on slip gauges 102 which are placed on the surface 104 so as to make the surface 104 in line with the work piece/ taper job 202. A plurality of slip gauges 102 of different heights are combined and placed on the surface 104 till the tapered surface of the workpiece 202 is parallel to the grinding wheel 204 and a dial 206 connected to the arrangement as illustrated in the figures, reads zero. An angle ? thus formed, when one end of the sine bar 100 is titled due to the plurality of slip gauges 102, is then measured using the sine rule to obtain angle of the work piece. The sine rule is as follows:
Sin ? = h / l
where, ‘h’ is total height of slip gauges 102 placed between the roller and the surface, and ‘l’ is the length of sine bar. The length ‘l’ is considered to be the distance between the center of the rollers 100a and 100b. Thus, if the angle ? is known, the height can be calculated and slip gauges can then be used to obtain that height in order to achieve uniform results in case plurality of workpieces need to be grinded/manufactured. Different angles can be measured or set by using the sine bar 100 for different work pieces.
Figure 3a illustrates a workpiece 302 having a backward decreasing taper which is to be fitted in the machine chuck 200, and Figure 3b illustrates another workpiece 304 having a backward increasing taper to be fitted in the machine chuck 200.
The accuracy of angular measurements of sine bars depends on the distance between centres of its two rollers. It is difficult to hold a sine bar physically in a fixed position as the slip gauges tend to shift causing angular errors. Additionally, longer shift gauges are not as accurate as shorter gauges, and so sine bars are not typically suitable for angles that exceed 45°. Also, in case of higher angles, the difference in deformation occurs at a point of contact where a roller is placed on the slip gauges as the load is shifted towards another roller. Moreover, it is difficult for an operator/ user to set and maintain a specific angle in case of work pieces having backward increasing taper. To limit these drawbacks of conventional sine bar using slip gauges, the present disclosure envisages an attachment for a sine bar.
A preferred embodiment of the attachment, of the present disclosure will now be described in detail with reference to the Figure 4 though Figure 6.
Figure 4 illustrates an isometric view of an attachment 400 in accordance with one embodiment of the present disclosure. Figure 5 illustrates a front view of a sine bar 500 and the attachment 400. Figure 6a illustrates a schematic representation of the sine bar 500 in an an operative configuration accordance with one embodiment of the present disclosure. Figure 6b illustrates a schematic representation of the sine bar 500 in an operative configuration in accordance with another embodiment of the present disclosure.
The attachment 400 for the sine bar 500 has a body 402 that is defined by a first surface 402a and a second surface 402b. The first surface 402a has a trapezoidal configuration. In an embodiment, the first surface 402a has at least two sides configured opposite to each other that makes a predetermined angle with each other, thereby defining the trapezoidal configuration. In another embodiment, the predetermined angle is in the range of 5 degrees to 25 degrees.
The second surface 402b extends from an operative flat end 402i of the first surface 402a, and is configured to securely couple the sine bar with the attachment 400. In an embodiment, the second surface 402b is adapted to couple the sine bar with the attachment 400 by means of at least one fastener selected from a group consisting of nut and bolt, threaded screw, cap screw, and rivet. In another embodiment, the second surface is adapted to couple the sine bar with the attachment by means of at least one magnet 408.
In one embodiment, the body 402, thereby the attachment 400, has an L – shaped configuration.
The attachment 400 further includes a cover plate 404 that is mounted on the first surface 402a, and is configured to align the attachment 400 with the sine bar 500. In an embodiment, the cover plate 404 is mounted on the first surface 402a by means of at least one fastener 406 that is selected from a group consisting of nut and bolt, threaded screw, cap screw, and rivet.
In an embodiment, the attachment 400 includes the body 402, typically an angle adjusting body, the cover plate 404, two cap screws 406, and two button magnets 408.
In an operative configuration, the cover plate 404 is attached to the angle adjusting body 402. The cover plate 404 facilitates accurate alignment of the attachment 400 with the sine bar 500. The cap screws 406 are used to secure the cover plate 404 with the body of the sine bar 500. The button magnets 408 firmly attach the attachment 400 to the sine bar 500. In one embodiment, the attachment 400 having a pre-determined angle is attached to the sine bar 500 to change angle of an arrangement, consisting of a work piece/ taper job 602 clamped to a machine chuck 600, to the pre-determined angle. The work piece 602 is then grinded as required by a grinding spindle 604.
In another embodiment, the attachment 400 having a pre-determined angle is attached to the sine bar 500 and slip gauges are attached to one of the roller of the sine bar 500 to achieve the desired angle. For example, if the attachment 400 has an angle of 10°, slip gauges that are required to achieve an angle ‘?’ is calculated as follows:
Sin (10- ?) = x1 / l
i.e. x1 = Sin (10- ?) X l
where, x1 is the total height of slip gauges that is required to be achieved, and ‘l’ is the length of sine bar.
The attachment of the present disclosure fits easily on grinding machines including universal and OD grinders. It is easy to use and eliminates component rejection. The use of the attachment also reduces process time and requirement of skilled labour.

TECHNICAL ADVANCES AND ECONOMICAL SIGNIFICANCE
The present disclosure described herein above has several technical advantages including but not limited to the realization of an attachment for a sine bar that:
- limits requirement of skilled labor;
- reduces complexity in angular measurements;
- easily fits with all types of grinding machines; and
- reduces process time
The disclosure has been described with reference to the accompanying embodiments which do not limit the scope and ambit of the disclosure. The description provided is purely by way of example and illustration.
The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
The foregoing description of the specific embodiments so fully revealed the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.
The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results.
Any discussion of documents, acts, materials, devices, articles or the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.
While considerable emphasis has been placed herein on the components and component parts of the preferred embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other changes in the preferred embodiment as well as other embodiments of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.
,CLAIMS:1. An attachment (400) for a sine bar (500) having at least two rollers (500a, 500b), said attachment (400) having a body (402) defined by a first surface (402a) and a second surface (402b), wherein said first surface (402a) has a trapezoidal configuration and said second surface (402b) extends from an operative flat end (402i) of said first surface (402a), and configured to securely couple said sine bar (500) with said attachment (400).
2. The attachment as claimed in claim 1, wherein said first surface (402a) has at least two sides configured opposite to each other and making a predetermined angle with each other, thereby defining said trapezoidal configuration.
3. The attachment as claimed in claim 2, wherein said predetermined angle is in the range of 5 degrees to 25 degrees.
4. The attachment as claimed in claim 1, wherein said second surface (402b) is adapted to couple with said sine bar (500) by means of at least one fastener selected from a group consisting of nut and bolt, threaded screw, cap screw, and rivet.
5. The attachment as claimed in claim 1, wherein said second surface is adapted to couple with said sine bar by means of at least one magnet (408).
6. The attachment as claimed in claim 1, wherein said attachment further includes a cover plate (404) mounted on said first surface (402a), and is configured to align said attachment (400) with said sine bar (500).

7. The attachment as claimed in claim 1, wherein said cover plate (404) is mounted on said first surface (402a) by means of at least one fastener 406) selected from a group consisting of nut and bolt, threaded screw, cap screw, and rivet.
8. The attachment as claimed in claim 1, wherein said body (402) has an L – shaped configuration.