DESC:FORM-2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See section 10 and rule 13)

Title: A WEDGE-LOCK

APPLICANT DETAILS:
(a) NAME: BHARAT ELECTRONICS LIMITED
(b) NATIONALITY: Indian
(c) ADDRESS: Outer Ring Road, Nagavara, Bangalore 560045, Karnataka, India

PREAMBLE TO THE DESCRIPTION:
The following specification (particularly) describes the nature of the invention (and the manner in which it is to be performed):
A WEDGE-LOCK

FIELD OF INVENTION:
The present invention relates to wedge-locks that are used as retainers of PCBs and electronic modules within guide ways.

BACKGROUND OF THE INVENTION:
The following background discussion includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication expressly or implicitly referenced is prior art.
Generally, wedge-locks contain a long shaft such as screws which control the expansion of wedges. The shaft is retained intact within the wedges with the help of holes formed along their axis. The size of the cross section and the length of these holes vary based on the application. These holes are considerably long in comparison with their cross-section dimensions. Therefore, formation of the holes requires special operations such as extrusion or EDM or machining with special tools such as profile slot cutters which have significant inherent limitations. Conventionally, wedge-lock mechanisms to retain PCBs/Electronic modules are known however, wherever central axial holes had been a need such central holes would have been made with special operations such as extrusion or EDM or machining with special tools such as profile slot cutters. The ’in-between wedges’ of the wedge-lock mechanisms are made using the conventional manufacturing processes as described above. Extrusions are not cost efficient for small volume production and other approaches are time consuming leading to low productivity and high cost of production.
Accordingly, there exists a need to provide a wedge-lock to overcome one or more of the aforementioned problems.

OBJECTIVES OF THE INVENTION:
The primary object of the present invention is to overcome the problem stated in the prior art.
Another object of the present invention is to provide a wedge-locks that are used as retainers of PCBs and electronic modules within guide ways.

SUMMARY OF THE INVENTION:
The present invention provides a wedge-lock comprising;
a) plurality of side wedges (2) and (4);
b) a shaft (1) of circular cross section; and
c) an in-between wedge(s)(3), where the in-between wedge (3) comprises a rectangular prism object whose side faces (3D) are cut typically at an angle of 450, where along the axis of the wedge (3) a central axial hole (3A) of suitable cross section formed configured to retain the shaft (1).
In the current embodiment, the central axial hole (3A) is formed by carving a two pockets (3C and 3B) in combination on top and bottom surface of the wedge (3) respectively.
In an embodiment, the pocket (3B) is carved from the bottom side towards top side till the boundary decided by the central axial hole (3A) and the pocket 3C is carved from the top side till the boundary decided by the central axial hole.
In an embodiment, the pockets (3B) and (3Cx2) overlap each other thus allowing formation of the central axial hole (3A) along the axis of the wedge, where the depth of pockets (3C) and (3B) till a certain extent is governed by the boundary of the central axial hole (3A) in transverse direction.
In an embodiment, the width (3A1) and a height (3A2) of the intended longitudinal hole(3A) govern the length, width and depth of top and bottom pockets (3C and 3B),where the pocket (3B) from the bottom side is such that the length (3B2) of the pocket leaves uncut a width (3E) on both ends of the bottom side, where the width (3B1) and a depth (3B3) of the bottom pocket is governed by the intended dimensions of the central axial hole (3A).
In an embodiment, the width, depth and length (3B1, 3B2 & 3B3) collectively provides mechanical strength in the ‘in-between wedge' to withstand the load offered by adjacent wedges during expansion of wedges in the application.
In an embodiment, the pockets (3Cx2) from the top side at two longitudinal ends is such that the width (3C2) coincides with width (3B2) from bottom side. Length (3C1) of the pocket (3C) is such that, pockets(3C) thus formed sufficiently overlaps the pocket (3B) to form longitudinal hole (3A).

DETAILED DESCRIPTION OF DRAWINGS:
To further clarify advantages and features of the present invention, a more particular description of the invention will be rendered by reference to specific embodiments thereof, which is illustrated in the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of their scope. The invention will be described and explained with additional specificity and detail with the accompanying drawings in which:
Fig. 1: illustrates an isometric view of a wedge-lock.
Fig. 2: illustrates an isometric view of in-between wedges.
Fig. 3: illustrates a detailed side view and a cross-sectional view of the in-between wedges.

DETAILED DESCRIPTION:
For the purpose of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated system, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.

It will be understood by those skilled in the art that the foregoing general description and the following detailed description are exemplary and explanatory of the invention and are not intended to be restrictive thereof.
The terms “comprises”, “comprising”, “includes”, or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a setup, device or method that comprises a list of components or steps does not include only those components or steps but may include other components or steps not expressly listed or inherent to such setup or device or method. In other words, one or more elements in a system or apparatus proceeded by “comprises... a” does not, without more constraints, preclude the existence of other elements or additional elements in the system or method.
According to an exemplary embodiment, the present invention provides a wedge-lock with in-between wedges that effectively eliminate usage of special tools or operations thus improving productivity and cost benefit. The in-between wedges are provided with pockets in two directions (top and bottom) which enable the formation of the longitudinal holes without any dedicated operations for the longitudinal hole. The in-between wedges are provided with pockets in two directions (top and bottom) which enable general standard end milling cutters to carve out longitudinal holes needed for expansion shafts.
According to the exemplary embodiment, the size and location of the pockets are such that structural integrity of the ‘in-between wedge’ is ensured. The size and location of the pockets are such that depth(d) to diameter(D) ratio during milling is kept minimum (typically less than 5) which enable utilization of standard general end milling cutters for manufacturing. Because of this, usage of special tools or operations is effectively eliminated thus improving productivity and cost benefit.
In an embodiment, the present invention provides a wedge-lock comprising;
a) plurality of side wedges (2) and (4);
b) a shaft (1) of circular cross section; and
c) an in-between wedge(s)(3), where the in-between wedge (3) comprises a rectangular prism object whose side faces (3D) are cut typically at an angle of 450, where along the axis of the wedge (3) a central axial hole (3A) of suitable cross section formed configured to retain the shaft (1).
In an embodiment, the central axial hole (3A) is formed by carving a two pockets (3Cx2 and 3B) in combination on top and bottom surface of the wedge (3) respectively.
In an embodiment, the pocket (3B) is carved from the bottom side towards top side till the boundary is decided by the central axial hole (3A) and the pocket 3C is carved from the top side till the boundary decided by the central axial hole.
In an embodiment, the pockets (3B) and (3C) overlap each other thus allowing formation of the central axial hole (3A) along the axis of the wedge, where the depth of pockets (3C) and (3B) till a certain extent is governed by the boundary of the central axial hole (3A) in transverse direction.
In an embodiment, the width (3A1) and a height (3A2) of the intended longitudinal hole(3A) govern the length, width and depth of top and bottom pockets (3C and 3B),where the pocket (3B) from the bottom side is such that the length (3B2) of the pocket leaves uncut a width (3E) on both ends of the bottom side, where the width (3B1) and a depth (3B3) of the bottom pocket is governed by the intended dimensions of the central axial hole (3A).
In an embodiment, the width, depth and length (3B1, 3B2 & 3B3) collectively provides mechanical strength in the ‘in-between wedge' to withstand the load offered by adjacent wedges during expansion of wedges in the application.
In an embodiment, the pockets (3C) from the top side at two longitudinal ends is such that the width (3C2) coincides with width (3B2) from bottom side. Length (3C1) of the pocket (3C) is such that, pocket(3C) thus formed sufficiently overlaps the pocket (3B) to form longitudinal hole (3A).
Referring Figures 1-3, according to an exemplary aspect, the present invention discloses a three-piece wedge-lock having in-between wedges. The wedge-lock (100) has side wedges (2) and (4), a shaft (1) of circular cross section or as suitable for the application and an in-between wedge(s)(3) (one or more as suitable for the application). The present invention discloses a structure of the ‘in-between wedges’ (3) and does not typically limit to the shown embodiment but applies to all ‘in-between wedges’ of wedge-locks where in long hole of any suitable cross sections is necessary to retain a shaft such as screws to enable wedlock expansion.
According to an exemplary embodiment, the present invention discloses the in-between wedges (3) that are generally rectangular prism objects whose side faces (3D) are cut typically at an angle of 450. Along the axis of this wedge, a hole (3A) of suitable cross section as per the need of the application is formed which is utilized for retaining the shaft (1). The central axial hole (3A) is formed by carving two pockets (3Cx2 and 3B) in combination on top and bottom surface of the wedge respectively.
According to the exemplary embodiment of the present invention, the pocket 3B is carved from the bottom side towards top side till the boundary decided by the retaining longitudinal hole as per the need of the application and the pocket 3C is carved from the top side till the boundary decided by the retaining axial hole as per the need of the application. The pockets 3B and 3C overlap each other thus allowing formation of longitudinal hole 3A along the axis of the wedge. The depth of pocket 3C and 3B till a certain extent is governed by the boundary of the anticipated axial hole in transverse direction.
According to the exemplary embodiment of the present invention, the location of pockets (3B and 3C) is relative to each other ensures the formation of axial hole 3A without the need of performing manufacturing operations such as wire EDM along the axis or profile slot cutters or extrusion. Elimination of non-conventional special operations and special tools result in improved productivity thereby saving cost and time. The depth of pocket 3C and 3B is also such that the in-between wedge thus formed remains as a single integral wedge with sufficient strength to withstand the load applied on it by neighbouring wedges during the expansion of wedges for the purpose of retaining the PCB/module within guide ways.
According to the exemplary embodiment of the present invention, such particular placement of pockets (3B and 3C) has enabled usage of simple manufacturing methods namely pocket milling with either end mill cutter or round nose end mill cutter or similar cutters as per the application. Because of this, depth (D) to Diameter(d) ratio of the tools is typically less than 5 which eases manufacturability and improves productivity.
According to the exemplary embodiment of the present invention, the ‘in-between wedge’ has pockets (3Cx2 and 3B) from top and bottom side thus forming a longitudinal hole (3A) of desired cross section (both profile and size), as per the application for the purpose of retaining the shaft of a wedge-lock. The said ‘in-between wedge’ may or may not contain fixing provision in the form of holes based on the application. The ‘in-between wedge’ is independent or built as an integral part of housings/chassis/modules based on the application and need.
According to the exemplary embodiment of the present invention, based on the intended cross section of the longitudinal hole 3A, depth and width of the pockets 3C and 3D is arrived. Width (3A1) and height (3A2) of the intended longitudinal hole(3A) govern the length, width and depth of top and bottom pockets (3C and 3B). The pocket 3B from the bottom side is such that the length (3B2) of the pocket leaves uncut width 3E on both ends of the bottom side. Width (3B1) and depth (3B3) of the bottom pocket is governed by the intended dimensions of longitudinal hole (3A). The uncut width 3E also allows space for mounting holes. The width, depth and length (3B1, 3B2 & 3B3) in combination is such that adequate mechanical strength is ensured in the ‘in-between wedge' to withstand the load offered by adjacent wedges during expansion of wedges in the application.
According to the exemplary embodiment of the present invention, the pocket 3C from the top side at two longitudinal ends is such that the width (3C2) coincides with width (3B2) from bottom side. Length (3C1) of the pocket (3C) is such that, pocket(3C) thus formed sufficiently overlaps the pocket (3B) to form longitudinal hole (3A).
According to the exemplary embodiment of the present invention, the pockets 3C and 3B are in conjunction form longitudinal hole 3A. The pockets 3C and 3B enable general end milling operations with end mill cutters or ball nose cutters with depth to diameter ratio typically less than 5, rather than complicated manufacturing operations such as t-slot milling, extrusion and wire EDM in longitudinal direction. The in-between wedge may be used singular or in plurality as suitable for the application.
The foregoing description of the invention has been set merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the substance of the invention may occur to person skilled in the art, the invention should be construed to include everything within the scope of the invention.
,CLAIMS:We Claim:

1. A wedge-lock comprising;
a) plurality of side wedges (2) and (4);
b) a shaft (1) of circular cross section; and
c) an in-between wedge(s)(3), where the in-between wedge (3) comprises a rectangular prism object whose side faces (3D) are cut typically at an angle of 450, where along the axis of the wedge (3) a central axial hole (3A) of suitable cross section formed configured to retain the shaft (1).
2. The wedge-lock as claimed in claim 1, wherein the central axial hole (3A) is formed by carving a two pockets (3C and 3B) in combination on top and bottom surface of the wedge (3) respectively.
3. The wedge-lock as claimed in claim 1, wherein the pocket (3B) is carved from the bottom side towards top side till the boundary decided by the central axial hole (3A) and the pocket 3C is carved from the top side till the boundary decided by the central axial hole.
4. The wedge-lock as claimed in claim 1, wherein the pockets (3B) and (3C) overlap each other thus allowing formation of the central axial hole (3A) along the axis of the wedge, where the depth of pockets (3C) and (3B) till a certain extent is governed by the boundary of the central axial hole (3A) in transverse direction.
5. The wedge-lock as claimed in claim 1, wherein a width (3A1) and a height (3A2) of the intended longitudinal hole(3A) govern the length, width and depth of top and bottom pockets (3C and 3B),where the pocket (3B) from the bottom side is such that the length (3B2) of the pocket leaves uncut a width (3E) on both ends of the bottom side, where the width (3B1) and a depth (3B3) of the bottom pocket is governed by the intended dimensions of the central axial hole (3A).
6. The wedge-lock as claimed in claim 1, wherein the width, depth and length (3B1, 3B2 & 3B3) collectively provides mechanical strength in the ‘in-between wedge' to withstand the load offered by adjacent wedges during expansion of wedges in the application.
7. The wedge-lock as claimed in claim 1, wherein the pockets (3Cx2) from the top side at two longitudinal ends is such that the width (3C2) coincides with width (3B2) from bottom side. Length (3C1) of the pocket (3C) is such that, pocket(3C) thus formed sufficiently overlaps the pocket (3B) to form longitudinal hole (3A).