DESC:FIELD OF INVENTION

The present invention relates to the production of sheet metal dies. In particular, the present invention relates to machining of cam sliders used as a sliding part driven by cam driver in dies. More particularly, the present invention relates to a special stopper for cam slider set-up on a CNC machine, which facilitates in holding of odd-shaped cam slider during CNC machining for a very quick machining operation thereof.

BACKGROUND OF THE INVENTION

Conventionally for setting-up the cam slider for machining operation in the sheet metal dies, a series of operations and adjustments are required to be done, which is a time consuming, unsafe and un-ergonomic activity.

This method of setting up cam sliders in the sheet metal dies includes following steps:

• Arranging all the accessories required for cam slider set-up on the machine table i.e. spacers, clamps, clamping studs, bolts, washers, screw jacks, lever dial and hammer etc.

• Loading the cam slider, after properly aligning the spacers on machine table.

• Picking up a cam slider, loading it on the machine table and adjusting the clamping stopper at the respective position and manual tightening.

• Aligning the cam slider with respect to the machine axis within 10 microns with the help of the lever dial and hammer i.e. called Line truing.

• Setting up the work piece (cam slider) central axis both in X and Y direction.

• Finally, run the machine program for the machining operation on the cam sliders.

PRIOR ART

US 5904064 A discloses a cam assembly for use in a pressing machine having a lower cam to be fixed to the base of the pressing machine, a spring-biased sliding cam whose front surface is allotted to fix a machining tool and a cam holder to be fixed to the upper frame of the pressing machine. The sliding cam is operatively combined with the lower cam to slide on the inclined surface of the lower cam synchronously with the rising and descending of the upper frame of the pressing machine, whereas the cam holder and the sliding cam is so combined as to leave a predetermined space defined therebetween, thereby permitting the sliding cam to be held slidable in the cam holder. The cam assembly further has a spacer to be inserted in the predetermined space and detachable fastening means to fix the sliding cam in the cam holder as if the slider were like with the upper frame of the pressing machine staying at its lower dead end. A required machining to be affected on the tool mount of the sliding cam for changing the machining tool can be advantageously affected in situ without disassembling the cam assembly.

US 20110167954 A1 discloses a cam device including: a cam holder; a cam slider, and a cam-driver in order to make easier to change the size of a cam device during press mold design, wherein such cam devices are grouped depending on the basis of width dimensions in combination of hardness of a sliding contact surface of the cam holder and a sliding contact surface on the cam slider end, and hardness of a cam surface of the cam driver and a cam surface of the cam slider, and the design structures of the respective groups are determined in such a manner that the maximum process ability in a certain group among the groups is larger than the minimum process ability of an adjacent group having a larger width dimension, and smaller than the maximum process ability in an adjacent group having a smaller width dimension.

DISADVANTAGES WITH THE PRIOR ART

However, the main disadvantages associated with the conventional method of setting up the cam sliders units for performing cam slider machining operation in sheet metal dies are as follows:
• Time required for setting-up the cam slider units is very high (e.g. about 80 minutes per unit).

• This method involves NVAs (Non-value adding activities).

• Substantial care must be taken by the machine operators during this lengthy and complex setting-up operation from the safety point of view.

• High-skilled operators are required.

• Entire operation is quite unergonomic and it is very difficult to clamp the cam sliders due to odd shapes thereof.

• Variation in the machining quality from one operator to another because of differences in their skills.

Therefore, in order to overcome all above disadvantages of the conventional method, there is a need for devising an improved method for substantially reducing the setting up time for cam slider units on a CNC machines.

OBJECTS OF THE INVENTION

Some of the objects of the present invention - satisfied by at least one embodiment of the present invention - are as follows:

An object of the present invention is to provide a special stopper for performing setting up the cam slider unit on CNC machines for an easy clamping thereof.

Another object of the present invention is to provide a special stopper for setting up the cam slider unit on CNC machines for a quick machining thereof.

Still another object of the present invention is to provide a special stopper for substantially reducing the setting up time of the cam sliders on CNC machines.

Yet another object of the present invention is to provide a special stopper for setting up the cam slider unit on CNC machines, which eliminates the non-value adding activities and ensures the safety of the machine operators.
A further object of the present invention is to provide a special stopper for setting up the cam slider unit on CNC machines, which reduces the lead time for increasing the productivity of the die shop.

A further object of the present invention is to provide an improved method for setting up the cam slider unit on CNC machines, which involves ergonomic, very simple, operator friendly method steps.

These and other objects and advantages of the present invention will become more apparent from the following description, when read with the accompanying figures of drawing, which are however not intended to limit the scope of the present invention in any way.

SUMMARY OF THE INVENTION

In accordance with the present invention, there is provided a special stopper for cam slider set-up on CNC machine, the stopper is configured as a substantially solid elongated body comprising:

• at least two clamping holes;

• at least two resting faces;

• at least one rib; and

• at least one lifting hole for provided on the body for easy lifting of the stopper by means of eye bolt/s;

wherein the clamping holes are provided for adjusting and tightening the cam slider to be set-up thereon, the resting faces are configured for resting the stopper in the slot provided in the table of the machine; and the slotted rib is configured for engaging the stopper in the slot.

Typically, the clamping holes are provided on one of the longitudinal faces of the body.

Typically, the first of the resting face is formed by one of the axial ends of the body.

Typically, the second of the resting face is formed as an extension protruding away from the first axial end of the body and disposed in the plane of the first resting face.

Typically, the rib is formed as a longitudinal slotted rib extending away from and in a plane of the longitudinal face of the body comprising the heads of the clamping holes.

Typically, the second resting face and the slotted rib are configured perpendicular to each other.

Typically, the lifting hole is configured on the first axial end of the body disposed away from the second axial end of the body forming the resting faces.

Typically, the second resting face and the slotted rib are preferably made equal in length and the length of the slotted rib is made smaller than the depth of the slot provided in the table of the machine.

In an embodiment of the present invention, there is also provided a case hardened mild steel (MS) stopper for cam slider set-up on CNC machine, the stopper is configured as a substantially solid elongated body of square cross-section and comprising:

• two clamping holes provided on one of the longitudinal faces of the body for adjusting and tightening the cam slider to be set-up thereon;

• two resting faces, the first resting face being formed by the second axial end of the body for resting the stopper in the slot provided in the table of the machine; and the second resting face being formed as an extension protruding away from the second axial end and disposed in the plane of the first resting face;
• a rib formed as a longitudinal slotted rib extending away from and disposed in a plane of the longitudinal face comprising the heads of the clamping holes, for engaging the stopper in the slot; and

• a lifting hole on the top end of the body for easy lifting and lowering of the special stopper by means of an eye bolt;

wherein the lifting hole being configured on the first axial end (top) of the body disposed away from the second axial end of the body forming the resting faces; the length of the slotted rib being made smaller than the depth of the slot provided in the table of the machine; and preferably the second resting face and said slotted rib being made equal in length.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The present invention will be briefly described with reference to the accompanying drawings.

Figure 1a shows the conventional method of setting up the cam slider on CNC machine table for machining in sheet metal dies.

Figure 1b shows the stopper used in the conventional method of cam slider setup as shown in Fig.1a.

Figure 2a shows the improved set-up using the special stopper configured in accordance with the present invention for performing the method of quickly setting up the cam sliders on CNC machines for machining in sheet metal dies.

Figure 2b shows the special stopper used for quickly setting up cam slider on CNC machines as shown in Fig.2a.

Figure 3 shows another perspective view of an exemplary embodiment of the special stopper configured according to the present invention for quickly setting up cam slider units on CNC machines.

Figure 4a shows a top view of the special stopper of Fig. 3.
Figure 4b shows a front view of the special stopper of Fig. 3.

Figure 4c shows a rear view of the special stopper of Fig. 3.

Figure 4d shows a left-hand side view of the special stopper of Fig. 3.

Figure 4e shows a right-hand side view of the special stopper of Fig. 3.

DETALED DESCRIPTION OF THE ACCOMPANYING DRAWINGS

Figure 1a shows a typical layout of performing the conventional method of setting up the cam slider on CNC machine table 20 for machining in sheet metal dies by using stopper 10.

Figure 1b shows the stopper 10 used in the layout of Fig. 1a for performing the conventional method for setting up cam slider 30 on CNC machine table 20.

Figure 2a shows the improved set-up using the special stopper 100 configured in accordance with the present invention for performing the method of setting up the cam sliders 30 quickly on the slots 40 of CNC machine table 20 for machining in sheet metal dies.

Figure 2b shows the special stopper 100 used in the layout of Fig. 2a for performing the improved method for setting up cam slider 30 quickly on the slots 40 of CNC machine table 20.

Figure 3 shows another perspective view of an exemplary embodiment of the special stopper 100 configured according to the present invention for setting up cam slider units quickly on slots 40 of CNC machine table 20. It includes two clamping holes 1, 2; two resting faces 3, 4; a slotted rib 5, all made on body 6 of stopper 100.

Figure 4a shows a top view of the special stopper 100 of Fig. 3 depicting the hole 7 provided on the body 6 for its easy lifting by using an eye bolt (not shown).

Figure 4b shows a front view of the special stopper 100 of Fig. 3 depicting two holes 1, 2; the resting face 3; a slotted rib 5 made on the body 6 thereof.

Figure 4c shows a rear view of the special stopper 100 of Fig. 3 depicting the holes 1, 2 provided on the body 6 thereof.

Figure 4d shows a left-hand side view of the special stopper 100of Fig. 3 depicting the two resting faces 3, 4 and a slotted rib 5 provided on its body 6.

Figure 4e shows a right-hand side view of the special stopper 100 of Fig. 3 depicting the two resting faces 3, 4 and a slotted rib 5 provided on its body 6.

DESCRIPTION OF THE INVENTION

The special stopper 100 (Figure 2a) is used for resting and supporting the cam slider units, which are made of mild steel (MS) and duly case hardened to improve its resistance to wear and tear, thereby improving the service life of the special stopper 100.

The stopper 100 includes two clamping bolt (M24) holes 1, 2 provided for adjusting and tightening of the job (cam slider units) in the horizontal; two resting faces 3, 4 for resting the stopper 100 on the machine table 20; a slotted rib 5 for engaging the stopper 100 in the slot 40 provided in the CNC machine table 20 and another (M12) hole 7 provided on the MS body 6 of the stopper 100 for its easily lifting by using the eye bolt (not shown).

WORKING OF THE INVENTION

The method of setting up the cam sliders in sheet metal dies devised in accordance with the present invention comprises the following sequential steps:
- Loading the special stopper 6 on a slot 40 of a vertical machining center (VMC) of a CNC machine 20 disposed with its front oriented towards the machine operator by using the slotted rib 4.

- Clamping and setting up of the stopper 6 by using clamping accessories.

- Putting the cam slider unit with proper butting on the stopper 6.

- Clamping the cam slider unit using two (2) M24 bolts.

- Setting up the cam slider axis (Truing) with the help of tooling holes.

- Starting the desired machining operation on CNC machine as per the NC program pre-stored therein.

TECHNICAL ADVANTAGES AND ECONOMIC SIGNIFICANCE

The special stopper configured in accordance with the present invention has the following technical and economic advantages:

• Special stopper facilitates in an easy clamping of the cam slider for setting it up on CNC machines.

• Facilitates quick machining of the cam slider units on CNC machines.

• Substantially reduces cam sliders setting up time on CNC machines, only 40 minutes required as against 80 minutes for conventional method, i.e. setting up time reduced by almost 50%.

• Eliminates non-value adding activities (NVAs) during machining of cam sliders on CNC machines.

• Ensures the safety of the machine operators during machining of cam sliders on CNC machines.

• Reduces the lead time for increasing the die shop’s productivity.

• Involves ergonomic, very simple, operator friendly method steps.

• Substantial cost saving of about 1.98 lakhs per year, considering 200 cam sliders (i.e. 200 x 0.66 = 132 x 1500 = INR 1,98,000).

• Reduction in operator’s fatigue by avoiding repetitive adjustments.

• Accurately locates the cam slider unit between both angular surfaces.

The foregoing description of the specific embodiments will so fully reveal 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 distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation.

The description provided herein is purely by way of example and illustration. The various features and advantageous details are explained with reference to this non-limiting embodiment in the above description in accordance with the present invention.

The descriptions of well-known components and manufacturing and processing techniques are consciously omitted in this specification, so as not to unnecessarily obscure the specification.

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, the skilled person will recognize that the embodiments herein can be practiced with modification within the spirit and scope of embodiments described herein.

Therefore, the skilled person can easily make innumerable changes, variations, modifications, alterations and/or integrations in terms of materials and method used to configure, manufacture and assemble various constituents, components, subassemblies, assemblies and in terms of the size, shapes, orientations and interrelationships without departing from the scope and spirit of the present invention.

The numerical values given of various physical parameters, dimensions and quantities are only approximate values and it is envisaged that the values higher or lower than the numerical value assigned to the physical parameters, dimensions and quantities fall within the scope of the disclosure unless there is a statement in the specification to the contrary.

Throughout this specification, the word “comprise”, or variations such as “comprises” or “comprising”, shall be understood to implies including a described element, integer or method step, or group of elements, integers or method steps, however, does not imply excluding any other element, integer or step, or group of elements, integers or method steps.

The use of the expression “a”, “at least” or “at least one” shall imply using one or more elements or ingredients or quantities, as used in the embodiment of the disclosure in order to achieve one or more of the intended objects or results of the present invention. ,CLAIMS:We claim:

1. A special stopper for cam slider set-up on CNC machine, said stopper is configured as a substantially solid elongated body comprising:

• at least two clamping holes;

• at least two resting faces;

• at least one rib; and

• at least one lifting hole for provided on said body for easy lifting of said stopper by means of eye bolt/s;

wherein said clamping holes are provided for adjusting and tightening the cam slider to be set-up thereon, said resting faces are configured for resting said stopper in the slot provided in the table of said machine; and said slotted rib is configured for engaging said stopper in said slot.

2. Stopper as claimed in claim 1, wherein said clamping holes are provided on one of the longitudinal faces of said body.

3. Stopper as claimed in claim 1, wherein the first of said resting face is formed by one of the axial ends of said body.

4. Stopper as claimed in claim 3, wherein the second of said resting face is formed as an extension protruding away from the first axial end of said body and disposed in the plane of said first resting face.

5. Stopper as claimed in claim 1, wherein said rib is formed as a longitudinal slotted rib extending away from and in a plane of said longitudinal face of said body comprising the heads of said clamping holes.

6. Stopper as claimed in claim 4 and 5, wherein said second resting face and said slotted rib are configured perpendicular to each other.

7. Stopper as claimed in claim 1, wherein said lifting hole is configured on the first axial end of said body disposed away from the second axial end of said body forming said resting faces.

8. Stopper as claimed in claim 1, wherein said second resting face and said slotted rib are preferably made equal in length and the length of said slotted rib is made smaller than the depth of the slot provided in the table of said machine.

9. A special stopper for cam slider set-up on CNC machine, said stopper is configured as a substantially solid elongated body of square cross-section and comprising:

• two clamping holes provided on one of the longitudinal faces of said body for adjusting and tightening the cam slider to be set-up thereon;

• two resting faces, the first resting face being formed by the second axial end of said body for resting said stopper in the slot provided in the table of said machine; and the second resting face being formed as an extension protruding away from said second axial end and disposed in the plane of said first resting face;

• a rib formed as a longitudinal slotted rib extending away from and disposed in a plane of said longitudinal face comprising the heads of said clamping holes, for engaging said stopper in said slot; and

• a lifting hole on the top end of said body for easy lifting and lowering of said special stopper by means of an eye bolt;

wherein said lifting hole being configured on the first axial end (top) of said body disposed away from the second axial end of said body forming said resting faces; the length of said slotted rib being made smaller than the depth of the slot provided in the table of said machine; and preferably said second resting face and said slotted rib being made equal in length.

10. Stopper for cam slider set-up on CNC machine as claimed in anyone of claims 1 to 9, wherein said stopper is made of mild steel (MS), preferably case-hardened for improving the resistance to wear and tear thereof, and thereby to increase the service life thereof.