DESC:COORDINATE MEASURING MACHINE WITH PNEUMATIC COUNTER BALANCE MECHANISM

Field of invention:

The present invention relates to coordinate measuring machines and more particularly, the present invention relates to a coordinate measuring machine with pneumatic counter balance mechanism.

Background of the invention:

Coordinate measuring machines (CMMs) are well known in a prior art. A coordinate measuring machine (CMM) is a device for measuring the physical and geometrical characteristics of an object. Typically, the CMM has a probe mounted on a probe shaft, which is movable along a second axis to make measurements of an object. The probe shaft is typically mounted to a carriage or a spindle which is movable in Z axis along a first axis perpendicular to the second axis. The first axis is typically movable along a third orthogonal axis, thus allowing the probe to take measurements in all three coordinate axes. The movement of the probe or carriage is accomplished either manually in one type of the CMM, where an operator grasps the probe shaft and physically moves the probe shaft in the desired direction, or automatically in a more sophisticated type of the CMM, where the probe shaft is moved by an automatic controller driving a motor on each axis.

In existing design of the CMMs, typically a bare pneumatic cylinder or dead weight is used to balance the Z axis spindle on which the probe is mounted. Further, in the existing CMMs, there is no provision of backup system for smooth movement of a piston rod of the pneumatic cylinder and safety against pressure loss inside the pneumatic cylinder which may cause the spindle fall down.

Accordingly, there exists a need to provide a coordinate measuring machine (CMMs) that overcomes abovementioned drawbacks by providing pneumatic counter balancing mechanism for the Z axis spindle thereof.

Objects of the invention:

An object of the present invention is to provide a pneumatic counter balancing mechanism with reservoir for Z axis of a coordinate measuring machine.

Another object of the present invention is to provide smooth movement of a piston rod of a pneumatic cylinder in the coordinate measuring machine.

Yet, another object of the present invention is to avoid fall down of the Z axis due to pressure drop in the pneumatic cylinder.

Summary of the invention:

Accordingly, the present invention provides a coordinate measuring machine (CMM) (hereinafter referred as, “the CMM”) with pneumatic counter balance mechanism. The CMM comprises of a first component, a second component, a pneumatic cylinder and a holding assembly with reservoir. The first component includes a probing system configured thereon. The second component is arranged perpendicular to a pair of guideways, wherein the pair of guideways is arranged on columns. The second component moves along the pair of guideways. Further, the first component is attached to the second component in perpendicular manner. The first component moves vertically in relation to the second component. Specifically, the first component is a spindle and more specifically, a Z-axis spindle.

The pneumatic cylinder is operably connected to the first component. The pneumatic cylinder includes a piston rod configured therein and a precision regulator configured thereon. The piston rod includes free end vented to atmosphere and other end in communication with the pneumatic cylinder. The precision regulator is arranged for regulating pressure inside the pneumatic cylinder. Weight of the second component along with the probing system is counter balanced by the pneumatic cylinder.

The holding assembly with reservoir operably attached to the first component for providing continuous and sufficient air supply with varying speed. Specifically, the holding assembly with reservoir is operably attached to the precision regulator. The holding assembly with reservoir includes an engaging means for holding the free end of the piston rod of the pneumatic cylinder. Specifically, the engaging means is a screw. The holding assembly with reservoir transmits the counter balanced forces to the machine structure. The holding assembly with reservoir is made like a frame that engages the first component. The holding assembly with reservoir is made up of hollow pipes that act as a reservoir, wherein hollow pipes of are made of any one of materials selected from stainless steel, aluminum and iron pipe with rust-free process.

When, the first component moves with predefined speed in downward direction and upward direction, an input air supply is given to the holding assembly with reservoir and then to the pressure regulator. Thereinafter, the input air rushes in and out from the pneumatic cylinder for counter-balancing the coordinate measuring machine (CMM). Smooth movement of the first component with variable speed depends on sufficient flow of the input air as per requirement. The coordinate measuring machine is selected from any of coordinate measuring machines (CMMs) including gantry CMM, fixed table cantilever CMM, moving bridge CMM, L-shaped bridge CMM, fixed bridge CMM, moving table cantilever CMM, column CMM, moving ram horizontal-arm CMM, fixed table horizontal-arm CMM and moving table horizontal-arm CMM. The pneumatic counter balance mechanism is used for any type of CMMs.

Brief description of the drawings:

Figure 1 shows a schematic drawing of a coordinate measuring machine, in accordance with an embodiment of the present invention;

Figure 2 shows a front view of a pneumatic counter balance mechanism of the coordinate measuring machine, in accordance with the present invention;

Figure 3 shows a side view of the pneumatic counter balance mechanism of the coordinate measuring machine, in accordance with the present invention;

Figure 4 shows a perspective view of the pneumatic counter balance mechanism of the coordinate measuring machine, in accordance with the present invention; and

Figure 5 shows various types of the coordinate measuring machines, in accordance with alternative embodiments of the present invention.

Detailed description of the embodiments of the invention:

The foregoing objects of the present invention are accomplished and the problems and shortcomings associated with the prior art, techniques and approaches are overcome by the present invention as described below in the preferred embodiments.

The present invention provides a coordinate measuring machine with counter balancing mechanism for Z axis spindle, in accordance with the present invention. Specifically, a holding assembly with reservoir is used for backup supply to a pneumatic cylinder, in which pneumatic cylinder work as counter balancing mechanism for Z axis.

The present invention is illustrated with reference to the accompanying drawings, throughout which reference numbers indicate corresponding parts in the various figures. These reference numbers are shown in bracket in the following description.

Referring to figures 1 to 5, a coordinate measuring machine (CMM) (100) (hereinafter referred as, “the CMM (100)”) with pneumatic counter balance mechanism is shown, in accordance with the present invention. The CMM (100) comprises of a first component (30), a second component (10), a pneumatic cylinder (50) and a holding assembly with reservoir (60). The second component (10) is arranged perpendicular to a pair of guideways (20). The pair of guideways is arranged on columns (not shown). The second component (10) moves along the pair of guideways (20).

The first component (30) is attached to the second component (10) in perpendicular manner. The first component (30) moves vertically in relation to the second component (10). In preferred embodiment, the first component (30) is also known as a spindle (30) and more specifically, a Z-axis spindle (30). Specifically, the first component (30) is referred as the spindle (30) throughout the description for better understanding of the invention. The spindle (30) includes a probing system (not shown) configured thereon.

The pneumatic cylinder (50) is operably connected to the spindle (30). The pneumatic cylinder (50) includes a piston rod (50a) configured therein and a precision regulator (52) configured thereon. The piston rod (50a) includes free end vented to atmosphere and other end in communication with the pneumatic cylinder. Specifically, the precision regulator (52) is arranged for regulating pressure inside the pneumatic cylinder (50). In the CMM (100), weight of the spindle (30) along with the probing system is counter balanced by the pneumatic cylinder (50). When the spindle (30) moves with a predefined speed in downward direction and upward direction, an input air rushes in and out from the pneumatic cylinder (50).

The holding assembly with reservoir (60) is operably attached to the first component (30) for providing continuous and sufficient air supply with varying speed. In preferred embodiment, the holding assembly with reservoir (60) is operably attached to the precision regulator (52). More specifically, the holding assembly with reservoir (60) transmits the counter balanced forces to the machine structure. The holding assembly with reservoir (60) includes an engaging means (54) for holding the free end of the piston rod (50a) of the pneumatic cylinder (50). In an embodiment, the engaging means is a screw.

The holding assembly with reservoir (60) is made like a frame that engages the spindle (30). In an embodiment, the holding assembly with reservoir (60) is made up of hollow pipes that act as a reservoir. In the preferred embodiment, the hollow pipes of the holding assembly with reservoir (60) are made of any one of materials selected from stainless steel, aluminum and iron pipe with rust-free process.

When the spindle (30) moves with predefined speed in downward direction and upward direction, the input air supply is given to the holding assembly with reservoir (60) and then to the pressure regulator (52). Thereinafter, the input air rushes in and out from the pneumatic cylinder (50) for counter-balancing the coordinate measuring machine (CMM) (100). Specifically, smooth movement of the spindle (30) with variable speed depends on sufficient flow of the input air as per requirement.

Again, referring to figure 1, a gantry CMM is shown in accordance with an embodiment of the present invention. However, in alternative embodiments, the CMM (100) can be selected from any of coordinate measuring machines (CMMs) including fixed table cantilever CMM, moving bridge CMM, L-shaped bridge CMM, fixed bridge CMM, moving table cantilever CMM, column CMM, moving ram horizontal-arm CMM, fixed table horizontal-arm CMM and moving table horizontal-arm CMM as shown in the figure 5. The pneumatic counter balance mechanism disclosed in the present invention is applicable to any of the coordinate measuring machines (CMMs).

Advantages of the invention:

1. The CMM (100) with the pneumatic counter balance mechanism provides smooth movement of the piston rod (50a).

2. The CMM (100) with the pneumatic counter balance mechanism provides safety against the pressure loss inside the pneumatic cylinder (50) that may cause the spindle (30) fall down.

The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the present invention and its practical application, and to thereby enable others skilled in the art to best utilize the present invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omissions and substitutions of equivalents are contemplated as circumstances may suggest or render expedient, but such omissions and substitutions are intended to cover the application or implementation without departing from the spirit or scope of the claims of the present invention. ,CLAIMS:We claim:

1. A coordinate measuring machine (CMM) (100) with pneumatic counter balance mechanism, the coordinate measuring machine (100) comprising:
a first component (30) having a probing system configured thereon;
a second component (10) arranged perpendicular to a pair of guideways (20) arranged on columns, wherein the second component (10) moves along the pair of guideways (20) and further wherein, the first component (30) is attached to the second component (10) in perpendicular manner and the first component (30) moves vertically in relation to the second component (10);
a pneumatic cylinder (50) operably connected to the first component (30), the pneumatic cylinder (50) having,
• a piston rod (50a) configured therein, the piston rod (50a) having free end vented to atmosphere and other end in communication with the pneumatic cylinder (50), and
• a precision regulator (52) configured thereon for regulating pressure inside the pneumatic cylinder (50),
wherein weight of the first component (30) along with the probing system is counter balanced by the pneumatic cylinder (50); and
a holding assembly with reservoir (60) operably attached to the first component (30) for providing continuous and sufficient air supply with varying speed, the holding assembly with reservoir (60) having an engaging means (54) for holding the free end of the piston rod (50a) of the pneumatic cylinder (50), wherein the holding assembly with reservoir (60) transmits the counter balanced forces to the machine structure;
wherein, once the first component (30) moves with predefined speed in downward direction and upward direction, input air supply is given to the holding assembly with reservoir (60) and then to the pressure regulator (52), thereinafter the input air rushes in and out from the pneumatic cylinder (50) for counter-balancing the coordinate measuring machine (CMM) (100).

2. The coordinate measuring machine (100) as claimed in claim 1, wherein smooth movement of the first component (30) with variable speed depends on sufficient flow of the input air as per requirement.

3. The coordinate measuring machine (100) as claimed in claim 1, wherein the first component (30) is a spindle and more specifically, a Z-axis spindle.

4. The coordinate measuring machine (100) as claimed in claim 1, wherein the holding assembly with reservoir (60) is specifically attached to the precision regulator (52) in an operable manner.

5. The coordinate measuring machine (100) as claimed in claim 1, wherein the holding assembly with reservoir (60) is made like a frame that engages the first component (30).

6. The coordinate measuring machine (100) as claimed in claims 1 and 5, wherein the holding assembly with reservoir (60) is made up of hollow pipes that act as a reservoir.

7. The coordinate measuring machine (100) as claimed in claims 1 and 6, wherein the hollow pipes of the holding assembly with reservoir (60) are made of any one of materials selected from stainless steel, aluminum and iron pipe with rust-free process.

8. The coordinate measuring machine (100) as claimed in claim 1, wherein the engaging means (54) is a screw.

9. The coordinate measuring machine (100) as claimed in claim 1 is selected from any of coordinate measuring machines (CMMs) including gantry CMM, fixed table cantilever CMM, moving bridge CMM, L-shaped bridge CMM, fixed bridge CMM, moving table cantilever CMM, column CMM, moving ram horizontal-arm CMM, fixed table horizontal-arm CMM and moving table horizontal-arm CMM.

Dated this 07th day of April 2017

Madhavi Vajirakar
(Agent for the applicant)
(IN/PA-2337)