DESC:FORM 2

THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENT RULES, 2003

COMPLETE SPECIFICATION
(See Section 10 and Rule 13)

Title of invention:
APPARATUS FOR SPOT FACING OF SURFACE AND METHOD OF WORKING THEREOF

Applicant:
Mazagon Dock Shipbuilders Limited
A company Incorporated in India under the Companies Act, 1956
Under Ministry of Defence,
(A Govt. of India Undertaking)
Having address:
Dockyard Road, Mazagon,
Mumbai - 400010, Maharashtra, India

The following specification particularly describes the invention and the manner in which is to be performed.

CROSS-REFERENCE TO RELATED APPLICATIONS AND PRIORITY
[001] The present application claims priority from an Indian patent application 201921024040 filed on 18th June, 2019.
TECHNICAL FIELD
[002] The present subject matter described herein, in general, relates to an apparatus for spot facing of surfaces and more specifically relates to an apparatus for spot facing of under surfaces of a component.
BACKGROUND
[003] Generally, facing operation is a process of removing metal from the surface to make a flat metal surface. Facing operation is performed in almost every mechanical industry for various mechanical components. However, it is not easy to perform facing operation in complex areas of the components. In some cases, grinding operation is used instead. But, performing grinding in some under surface areas is also difficult as it is mostly a manual process. Usually, the difficulties in reaching surfaces are due to space restrictions and structure of the components. Also, manual processes may not be accurate and efficient. Hence, there is a need for a process or an apparatus that can perform facing operation with ease and with improved accuracy, specially in areas where grinding and facing is difficult to perform.

SUMMARY
[004] Before the present system and method are described, it is to be understood that this application is not limited to the particular machine or an apparatus, and methodologies described, as there can be multiple possible embodiments that are not expressly illustrated in the present disclosures. It is also to be understood that the terminology used in the description is for the purpose of describing the particular versions or embodiments only, and is not intended to limit the scope of the present application. This summary is provided to introduce aspects related to an apparatus for spot facing of surface, and the aspects are further elaborated below in the detailed description. This summary is not intended to identify essential features of the proposed subject matter nor is it intended for use in determining or limiting the scope of the proposed subject matter.
[005] The present subject matter relates to an apparatus for spot facing of surface and to a method used for performing spot facing. The apparatus is used for spot facing of an under surface of drilled holes. The apparatus comprises a spindle mounting device, a spindle and a cutting tool. Wherein the spindle mounting device comprises a tang, a socket, a flange and a stepped flange. The tang is mounted on a chuck of the machine. Further, the stepped flange comprises an opening for insertion of the spindle, a hole to hold the spindle, and a threaded hole to insert a bolt for securing the spindle in the stepped flange. Further, the spindle is inserted from the bottom side of the drilled hole of component and connected to the stepped flange. Further, the lower end of the spindle is provided with a groove to hold the cutting tool and the bottom surface of the spindle is provided with a threaded hole which goes up to the groove wherein the threaded hole is provision for inserting a bolt. The bolt secures the cutting tool in the groove such that the cutting tool may not move freely. The cutting tool is configured with at least two cutting edges and the cutting edges performs spot facing when the apparatus with the cutting tool rotates. The size of the cutting tool may vary based on a diameter of required spot facing area whereas the size of the spindle may vary based on a diameter of the drilled hole. Further, a bush is also mounted on an upper side of the drilled hole around the spindle to reduce the vibrations by supporting the spindle and by providing proper alignment to the spindle. The size of the bush may also varies based on the spindle diameter and the drilled hole diameter. The bush is mounted on the surface by using a C-clamp.
The method of spot facing on a surface with the help of spot facing apparatus comprises the steps of:
connecting the spindle mounting device to the machine by inserting the tang in the chuck of the machine, mounting the bush on the upper side of the drilled hole of component and mounting the bush with the C-clamp, mounting the spindle in the spindle mounting device by inserting the spindle from lower side of the drilled hole and connecting the one end of the spindle to the stepped flange while the other end configured with groove is kept on the lower side of the drilled hole, securing the cutting tool in the groove of the spindle by tightening of the bolt through the threaded hole, the machine is provided with the upward feed such that the cutting edges of the cutting tool touches the bottom surface of the drilled hole. Then performing the spot facing operation on the component.

BRIEF DESCRIPTION OF THE DRAWINGS
[006] The foregoing summary, as well as the following detailed description of embodiments, is better understood when read in conjunction with the appended drawing. For the purpose of illustrating the disclosure, there is shown in the present document example constructions of the disclosure, however, the disclosure is not limited to the specific methods and apparatus disclosed in the document and the drawing:
[007] The detailed description is described with reference to the accompanying figure. In the figure, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the drawing to refer like features and components.
[008] Figure 1 illustrates an apparatus for spot facing of surfaces, in accordance with an embodiment of the present subject matter.
[009] Figure 2 illustrates a cutting tool, in accordance with an embodiment of the present subject matter.
[0010] Figure 3 illustrates a bush, in accordance with an embodiment of the present subject matter.
[0011] Figure 4 illustrates an assembly with C-clamp, in accordance with an embodiment of the present subject matter.
[0012] Figure 5 (a) illustrates an under surface area of a drilled hole with stepped flange of the cutting tool, in accordance with an embodiment of the present subject matter.
[0013] Figure 5 (b) illustrates an upper surface of a drilled hole with stepped flange of the apparatus and the bush, in accordance with an embodiment of the present subject matter.
[0014] Figure 6 illustrates a spot faced area, in accordance with an embodiment of the present subject matter.
[0015] Figure 7 illustrates a washer with a bolt fastened after spot facing, in accordance with an embodiment of the present subject matter.
[0016] The figure depicts various embodiments of the present disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following discussion that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.
DETAILED DESCRIPTION
[0017] Some embodiments of this disclosure, illustrating all its features, will now be discussed in detail. The words "comprising", “having”, and "including," and other forms thereof, are intended to be equivalent in meaning and be open ended in that an item or items following any one of these words is not meant to be an exhaustive listing of such item or items, or meant to be limited to only the listed item or items. Although any systems and methods similar or equivalent to those described herein can be used in the practice or testing of embodiments of the present disclosure, the exemplary, systems and methods are now described. The disclosed embodiments are merely exemplary of the disclosure, which may be embodied in various forms.
[0018] Various modifications to the embodiment will be readily apparent to those skilled in the art and the generic principles herein may be applied to other embodiments. However, one of ordinary skill in the art will readily recognize that the present disclosure is not intended to be limited to the embodiments illustrated, but is to be accorded the widest scope consistent with the principles and features described herein.
[0019] An apparatus (100) is described, that may be used for spot facing of surfaces. Basically, the proposed apparatus (100) may be configured for spot facing of under surface of a drilled hole of component wherein the spot faced area may be used for mounting of a washer. The apparatus (100) may comprise a removable and non-removable part. The apparatus (100) may generally be used for spot facing of already drilled holes. A spindle (116) with provision to hold a cutting tool (200) may be configured as a main part of the apparatus (100). A cutting tool (200) of the proposed invention may vary based on an area where spot facing has to be performed. The apparatus (100) may be engaged in a drilling machine in order to perform the spot facing operation.
[0020] Referring to figure 1, an apparatus (100) for performing a spot facing operation on a surface is shown. The apparatus (100) comprises a spindle mounting device, a spindle (116) and a cutting tool (200). The spindle mounting device comprises a tang (102), a socket (104), a flange (106) and a stepped flange (108).
In an embodiment, the socket (104) may be configured to be of tapered shape. The tang (102) of the spindle mounting device may be fitted in the drilling machine. The stepped flange (108) comprises an opening (114), a hole (110) to hold the spindle (116) and a threaded hole (112) for inserting a bolt. The bolt may be fastened to secure the spindle (116) in the hole (110). Further, the spindle (116) may be removably connected to the stepped flange (108). An upper end of the spindle (116) may be inserted in the stepped flange (108) through the opening (114). A lower end of the spindle (116) may be provided with a groove (118). The groove (118) may be configured to hold the cutting tool (200). The lower end of the spindle (116) comprises a threaded hole (120) for inserting a bolt wherein the threaded hole (120) goes up to the groove (118). In an embodiment, the bolt may be fastened to secure the cutting tool (200) in the groove (118).
[0021] Referring now to figure 2, the cutting tool (200) configured to be fitted in the apparatus (100) is shown. The cutting tool (200) comprises a shank (202) wherein the shank (202) may be configured to be rest in the groove (118) of the spindle (116). The cutting tool (200) may be configured with at least two cutting edges (204). The cutting edges (204) may cut the surface and spot facing is performed by the cutting edges (204) on the under surface of the drilled hole. In an embodiment, the cutting tool (200) may be tightened with the help of the bolt in the groove (118) such that the cutting tool (200) may not move freely in the groove (118).
[0022] Referring now to figure 3, a bush (300) for holding the spindle (116) in place, is shown. The bush (300) may be placed on the upper surface of the part where spot facing has to be performed. The bush (300) provides alignment to the spindle 106 of the apparatus 100. The bush (300) may provide support to the spindle (116) and hence reduces vibrations to the spindle (116) and reduces chances of occurring any errors. The bush (300) may be configured with different inner diameter and outer diameter with reference to the hole where the spot facing has to be performed. In an embodiment, the bush (300) may be mounted on the surface with the help of a C-clamp (402) so that the bush (300) may not move while machining.
[0023] Referring now to figure 4, the C-clamp (402) configured to fix the bush (300) on the surface is shown. In an embodiment, the C-clamp (402) may be any structure such that the clamp does not allow misalignment of the bush (300).
[0024] Referring to figure 5 (a), the under surface area where spot facing may be performed is shown along with the cutting tool (200) fixed in the apparatus (100). In an embodiment, the diameter of the area of spot facing and the depth of cut of the spot facing area may vary.
[0025] Referring to figure 5 (b), the assembly of the apparatus (100) and the bush (300) mounted on the upper surface of the component comprising hole is shown.
[0026] Referring to figure 6, a surface after spot facing operation is shown. In an embodiment, the surface of spot facing may also be provided with depth based on the requirement. The diameter of the spot faced surface may also depend on a washer diameter which needs to be fitted on the surface while fastening of a bolt.
[0027] Referring to figure 7, a component with the bolt fastened in a drilled hole after spot facing of the lower surface of the drilled hole is shown.
[0028] Further, the method of working of the proposed invention is described. The apparatus (100) may be fitted in the drilling machine by inserting the tang (102) of the spindle mounting device in the chuck of the drilling machine. Further, before fitting the spindle (116) in the stepped flange (108), the bush (300) is fixed on the upper surface of the component comprising drilled hole. The C-clamp (402) is mounted on the bush (300) and fixed with fitting mechanism such that the bush (300) may not vibrate and hold the spindle (116) in proper alignment while performing spot facing operation. The upper end of the spindle (116) is inserted from the lower side of the drilled hole and fixed in the hole (110) of the stepped flange (108) with the help of the bolt. The bolt is fastened in the threaded hole (112) to secure the spindle (116) in the hole (110). The spindle (116) may be mounted in such a way that some part of the spindle (116) is kept above the upper surface of the drilled hole whereas some part of the spindle (116) is kept below the lower surface of the drilled hole. However, the lower end of the spindle (116) comprising the groove (118) must lie below the lower surface of the drilled hole. Further, the cutting tool (200) is inserted in the groove (118) of the spindle (116). Further, the bolt is inserted in the threaded hole (120) and tightened from the bottom of the spindle (116) in order to secure the cutting tool (200) in the groove (118). Further, when whole setup is ready, the drilling machine may be operated to lift the spindle (116) in the upper direction until the cutting edges (204) of the cutting tool (200) touches the lower surface of the component comprising drilled hole. After that, the drilling machine may be turned ON and the cutting tool (200) may rotate to perform spot facing on the under surface of the drilled hole. When the required depth of cut is achieved, the drilling machine may be turned OFF. In an embodiment, the upper feed of the drilling machine may be decided based on a thickness of washer which is to be secured on the lower surface of the component comprising drilled hole. After completion of the spot facing operation, the spindle (116) may be removed from the lower side of the component comprising drilled hole.
[0029] Exemplary embodiments discussed above may provide certain advantages. Though not required to practice aspects of the disclosure, these advantages may include the following.
[0030] Some of the embodiments of the apparatus enable the increased speed of the spot facing operation for lower surfaces of a plate.
[0031] Some of the embodiments of the apparatus enable the increased accuracy of the spot facing operation for under surfaces of a component.
[0032] Some of the embodiments of the apparatus enable reduced time for performing the spot facing operation for under surfaces of a component.
[0033] Some of the embodiments of the apparatus enable spot facing of the surfaces with different size of holes without making much changes to the apparatus.
[0034] Although implementations for the apparatus 100 have been described in language specific to structural features and/or methods, it is to be understood that the appended specifications are not necessarily limited to the specific features or methods described. Rather, the specific features and methods are disclosed as examples of implementation for the apparatus 100.
[0035] Following is a list of reference numerals used in accordance with the present subject matter.
Part No Part Name
102 Tang
104 Socket
106 Flange
108 Stepped Flange
110 Hole
112 Threaded Hole
114 Opening
116 Spindle
118 Groove
120 Threaded Hole
200 Cutting Tool
202 Shank
204 Cutting edge
300 Bush
402 C-clamp

,CLAIMS:
1. An apparatus (100) for spot facing of surface comprising:
a spindle mounting device, wherein the spindle mounting device configured with a tang (102), a socket (104), a flange (106) and a stepped flange (108) to hold a spindle (116) wherein the stepped flange (108) is configured with a hole (110), an opening (114) and a threaded hole (112);
wherein the spindle (116) is removably connected to the stepped flange (108) from one end and another end of the spindle (116) is configured with a provision to hold a cutting tool (200) and wherein a bottom of the spindle (116) is configured with a threaded hole (120) ;
the cutting tool (200) is configured to be fitted in the spindle (116) such that a cutting edge (204) of the cutting tool (200) enables the spot facing of the surface;
and wherein the apparatus (100) is configured to rotate while performing spot facing.

2. The apparatus (100) for spot facing of surface as claimed in claim 1, wherein the apparatus (100) is used for spot facing of under surfaces of drilled holes.

3. The apparatus (100) for spot facing of surface as claimed in claim 1, wherein the hole (110) of the stepped flange (108) is provided to securely hold the spindle (116) by inserting a bolt through the hole (112) of the stepped flange (108).

4. The apparatus (100) for spot facing of surface as claimed in claim 1, wherein the lower end of the spindle is configured with a groove (118) to hold the cutting tool (200).

5. The apparatus (100) for spot facing of surface as claimed in claim 1, wherein the threaded hole (120) of the spindle (116) is configured for inserting a bolt, in order to secure the cutting tool (200) in the groove (118).

6. The apparatus (100) for spot facing of surface as claimed in claim 1, wherein the cutting tool (200) is configured with at least two cutting edges (204) and a shank (202) and wherein a size of the cutting tool (200) is adapted to vary based on a diameter of a washer required to be mounted on the lower surface of the drilled hole.

7. The apparatus (100) for spot facing of surface as claimed in claim 1, wherein a bush (300) is mounted on upper side of the drilled hole of component around the spindle (116) to reduce vibrations to the spindle (116) by providing proper alignment and support to the spindle (116).

8. The apparatus (100) for spot facing of surface as claimed in claim 1, wherein the bush (300) is configured with different inner and outer diameter based on the spindle (116) diameter and the hole diameter.

9. The apparatus (100) for spot facing of surface as claimed in claim 1, wherein a C-clamp (402) is mounted on the bush (300) for mounting the bush (300) on the surface.

10. The method of spot facing on a surface with the help of spot facing apparatus comprising the steps of:
connecting the spindle mounting device to the machine by inserting the tang (102) in the chuck of the machine;
mounting the bush (300) on the upper side of the drilled hole of component and fixing the bush (300) with the C-clamp (402);
fitting the spindle (116) in the spindle mounting device by inserting the spindle (116) from lower side of the drilled hole and connecting one end of the spindle (116) to the stepped flange (108) while the other end configured with groove (118) is kept on the bottom side of the drilled hole;
securing the cutting tool (200) in the groove (118) of the spindle (116) by tightening of the bolt through the threaded hole (120).
the machine is provided with the upward feed such that the cutting edges (204) of the cutting tool (200) touches the bottom surface of the drilled hole; and
performing the spot facing operation on the component.