Micro-adjustable steady rest system

Abstract

The steady rest includes a work cover plate, a right cover plate, and a center plate sandwiched therebetween. The work cover plate has upper and lower guide tracks and a track engagement spring received in a cavity. The center plate is slidable between the work cover plate and the right cover plate. The center plate slidably engages upper and lower gripping arms, which are movable relative to the work cover plate between a clamped position and a retracted position. Tapered rails and rail engagement springs are disposed in rail recesses in the work cover plate. The rails are movable relative to each other to precisely adjust the position at which the workpiece is clamped and moved horizontally or vertically when the gripping arms are in the clamped position. The track and rail engagement springs have common mechanical characteristics, allowing them to be interchangeable, reducing inventory concerns.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Application No. 17 / 981,161, filed November 4, 2022, the disclosure of which is incorporated herein by reference. [Technical Field]

[0002] The present disclosure relates to a finely adjustable steady rest system for positioning rotationally symmetric workpieces. [Background technology]

[0003] Adjustable steady rest systems are commonly used to secure a workpiece during machining operations such as, but not limited to, grinding, turning, milling, boring, etc. In such systems, a gripping arm secures the workpiece while a cutting tool, such as a grinding wheel, blade, or bit, removes material from the workpiece. Known steady rests include mechanisms for adjusting the position or location of the gripping arm, and therefore the workpiece, to improve the accuracy of the machining operation.

[0004] Today's machines often require tight tolerances. Such challenges are more prevalent in high production volumes. It is desirable to avoid adverse workpiece conditions such as out-of-roundness and roving.

[0005] End users expect adjustment mechanisms to be accurate, fine-tunable, repeatable, and reliable. Reducing the number of parts, especially the number of moving parts, is advantageous. This can improve the reliability of the mechanism and reduce the chance of moving parts coming into contact with contaminants. Furthermore, reducing the number of parts can potentially reduce the manufacturing cost and complexity of the tool.

[0006] Against this background, it would be desirable to provide a sophisticated adjustment system that allows for repeatable and higher accuracy with a minimum number of parts required to achieve such adjustment.

[0007] Ideally, such systems would be designed to minimize downtime and facilitate repairs.

[0008] Such adjustment mechanisms ideally have many parts that must work together so that none of them stick or interfere unnecessarily with one another when guided movement is required during the adjustment process. It is desirable to anticipate the possibility of such unwanted interference through better design modifications. For example, it is desirable to eliminate the possibility of a spring becoming "squeezed" between adjacent parts of the adjustment mechanism. Another example concerns situations where one part supports another moving part. Ideally, the interface between the two parts has a curved shape to prevent unwanted coupling interference between them. Such factors are important when two parts work together under the influence of large engagement forces.

[0009] To facilitate replacement and repair, it is useful for all springs in the adjustment mechanism to be of the same size, have common mechanical properties, and be easily replaceable.

[0010] Ideally, the spring should not be subjected to unnecessary compression during a single use or repeated uses, as such exposure can lead to a weakening of the spring's rebound properties.

[0011] Therefore, a mechanism that allows for a more precise adjustment system that meets the above design criteria is desirable.

[0012] Documents considered in making this application include US Pat. Nos. 9,174,317 and 8,955,419, which are incorporated herein by reference to the extent they do not contradict the disclosure herein. Summary of the Invention

[0013] Some embodiments of the disclosed steady rest adjustment mechanism have multiple parts that cooperate to prevent the parts from binding or interfering unnecessarily with one another when guided movement is required during the adjustment process. In such embodiments, the possibility of the spring being "squeezed" between adjacent parts of the adjustment mechanism is eliminated.

[0014] The present disclosure also addresses situations where a part supports another moving part. The mating surfaces defining the interface between the two parts have a curved shape to prevent unwanted coupling interference between them. Such a factor is important when the two parts cooperate under the influence of large engagement forces.

[0015] In one embodiment, the present disclosure provides a steady rest system for accurately positioning a rotating workpiece while being subjected to forces by one or more machine tools in a direction oblique (e.g., perpendicular) to the workpiece's axis of rotation. The steady rest includes a work cover plate (described further below) and a right cover plate (as viewed from the rear). Between these plates is a center plate (which moves parallel to the X-axis or horizontal axis). The work cover plate includes a pair of recesses that receive two guide tracks that significantly affect and enable finely tuned displacement of upper and lower gripping arms that secure and displace the workpiece.

[0016] Within the guide track, the roller guides are displaced in a precise, predictable and defined manner.

[0017] The center plate slidably engages upper and lower gripping arms that are movable between a closed clamping position and an open, retracted position to releasably secure the workpiece, allowing fine horizontal and vertical repositioning of the workpiece.

[0018] This allows for predictable fine adjustment of the gripped workpiece in the horizontal and vertical directions. [Brief explanation of the drawings]

[0019] The drawings described herein are intended to illustrate selected embodiments, but do not depict every possible embodiment, and are not intended to limit the scope of the present disclosure. [Figure 1] FIG. 1 is a perspective exploded view of a portion of the adjustable steady rest system with the right cover plate removed for clarity. [Figure 2] FIG. 2 is an exploded perspective view of the steady rest system. [Figure 3A] FIG. 3C is a vertical cross-sectional view of the steady rest system taken along line BB of FIG. 3B. [Figure 3B] FIG. 10 is a vertical cross-sectional view of the steady rest system with the right cover plate removed. [Figure 4A] FIG. 4A shows the various components during vertical adjustment. [Figure 4B] FIG. 4B shows the various components during vertical adjustment. [Figure 5A] FIG. 5A shows the various components during horizontal adjustment. [Figure 5B] FIG. 5B shows the various components during horizontal adjustment. [Figure 6] 10 shows the horizontal displacement of the clamped workpiece in response to rotation of the adjustment screw. [Figure 7] 10 illustrates vertical displacement of a clamped workpiece in response to rotation of another adjustment screw. [Figure 8A] 8A is a diagram of a previous steady rest. In the relationship between the rail pin 155 and the vertical rail 58 or horizontal rail 60 in FIG. 8A, the rail engagement spring 90 may be secured within the rail spring pocket 157. [Figure 8B]Figure 8B is a revised version of Figure 8A. To solve the problem of Figure 8A, rail washer 156 is added. This eliminates rail spring pocket 157 and changes the relationship between rail pin 155 and vertical rail 58 or horizontal rail 60. Additionally, spring 104 is characterized by a higher spring force.

[0020] Corresponding reference numbers indicate corresponding parts consistently throughout the several views. DETAILED DESCRIPTION OF THE INVENTION

[0021] Representative embodiments and improvements over previous steady rests are described in more detail below with reference to the accompanying drawings.

[0022] Components of a typical steady rest system

[0023] 1-8B, in one embodiment, an adjustable steady rest system (hereinafter "steady rest") 10 is provided that is adapted to clamp a workpiece and fine-tune its position as needed by horizontal or vertical displacement, or both horizontal and vertical displacement, during a machining operation (e.g., grinding or turning). In one embodiment, steady rest 10 preferably includes a work cover plate 14, a right cover plate 16 (as viewed from FIG. 3A), and a center plate 18 slidably disposed therebetween.

[0024] The steady rest 10 is adapted to grasp and displace a workpiece 12 vertically (FIGS. 4A, 4B, and 7) or horizontally (FIGS. 5A, 5B, and 6).

[0025] Upper and lower gripping arms 20, 22 (FIG. 1) and a cylinder / piston actuation mechanism 24 (FIG. 2) are provided. As described in more detail below, the actuation mechanism 24 is operable to move the center plate 18 and gripping arms 20, 22 between a clamped position in which the steady rest 10 grips the workpiece 12 and a retracted position in which the workpiece 12 is released and the gripping arms 20, 22 are retracted into the steady rest 10.

[0026] As depicted in Figure 2, the work cover plate 14 is a generally solid, flat plate having a plurality of threaded and unthreaded mounting openings 32 (Figure 2). Upper and lower sliding plates 28, 30 (Figure 1) are attached (directly or indirectly) to the work cover plate 14. The center plate 18 is adapted to be guided by and move between the sliding plates 28, 30. The upper and lower sliding plates 28, 30 have threaded and / or unthreaded openings 32 that align with the openings 26 in the work cover plate 14.

[0027] The right cover plate 16 (FIG. 3A) has openings that align with the openings 32 in the sliding plates 28 and 30 and the openings 26 in the working cover plate 14. Bolts 40 or other fasteners are received in some or all of the openings to secure the working cover plate 14 and the right cover plate 16 to the sliding plates 28 and 30 and to each other. The center plate 18 is sandwiched therebetween (as shown in FIGS. 1 and 3) and is horizontally movable between the sliding plates 28, 30.

[0028] The working and right side cover plates 14, 16 and the sliding plates 28, 30 cooperate to define a cavity 43 within which guide tracks 44, 46 are movably received. The guide tracks 44, 46 are adapted to move horizontally under the influence of heavy-duty track-engaging springs 42 (FIG. 1). The track-engaging springs 42 are selected to withstand repeated compression and rebound. For ease of maintenance, such springs preferably conform to the other springs described below.

[0029] As shown in FIGS. 1-2, the work cover plate 14 contains upper and lower guide tracks 44, 46 that are received within the cavity 43 (FIG. 1). Each guide track 44, 46 preferably has an elongated leg 50 and a shorter leg 52 (FIG. 2). The legs 50 of the upper and lower guide tracks 44, 46 preferably extend parallel to each other and parallel to the longitudinal axis -X (FIG. 6). Each short leg 52 extends laterally outward and away from the workpiece 12 from one end of the corresponding long leg 50 (i.e., an acute angle is formed between the long leg 50 and the short leg 52).

[0030] To displace the gripping arms 20, 22, and therefore the clamped workpiece 12, in precise, predictable, and finely metered amounts, multiple components work together to displace the workpiece vertically (FIGS. 4A, 4B, and 7) and horizontally (FIGS. 5A, 5B, and 6).

[0031] Shaped rails 58, 60 (FIG. 1) cooperate to precisely displace workpiece 12 vertically and horizontally with predictable accuracy in a manner described below. These rails are independently slidable within rail recess 48 (e.g., FIGS. 2-7). Vertical rail 58 has a flat surface 70 (enlarged view, FIG. 7) that contacts horizontal rail 60 and an opposing surface with angled portions 62, 64 that meet at opposite ends of a flat midsection.

[0032] The work cover plate 14 preferably extends perpendicular to the longitudinal axis XX and has threaded openings 92, 94 (FIG. 1) that communicate with the rail recess 48 (FIG. 2). Adjustment screws or rods 96, 98 (FIGS. 2, 6-7) threadingly engage the threaded openings 92, 94, respectively, and extend into the rail recess 48. Approximately 100 threads per inch are preferably provided to allow fine adjustment. An end 102 of the upper or vertical adjustment rod 98 abuts an end of the rail 58, ultimately providing fine vertical adjustment of the workpiece position ("vertical rail 58"). An end 100 of the lower or horizontal adjustment rod 96 abuts an end of the rail 60 (FIG. 5A) and ultimately providing fine horizontal adjustment of the workpiece position ("horizontal rail" 60).

[0033] Similar to the track engagement springs associated with the upper and lower guide tracks 44, 46, rail engagement springs 104 (FIG. 2) are disposed between the bottom surface 106 of the rail recess 48 and the corresponding ones of the vertical and horizontal rails 58, 60 (FIGS. 4A, 4B, 5A, and 5B). For interchangeability and ease of maintenance, all engagement springs preferably share common mechanical characteristics. The common characteristics eliminate inventory issues associated with purchasing different size springs.

[0034] Rail engagement springs 104 (FIG. 4B) bias rails 58, 60 into contact with axial ends 100, 102 of adjustment rods 96, 98. In this manner, rails 58, 60 are displaced toward and away from bottom surface 106 (as shown in FIGS. 4-5) as adjustment rods 96, 98 are moved along threaded openings 92, 94 into and out of rail recesses 48.

[0035] By threadably adjusting the position of the horizontal adjustment rod 96 (FIGS. 5A, 5B, and 6), the horizontal rail 60 slides against the wall of the rail recess 48. A relative angle (θ) is established between the wall and the side 72 of the horizontal rail 60 (FIG. 5A and enlarged view, FIG. 5B). Thus, movement of the horizontal rail 60 along the wall 56 creates a wedge-like effect, causing the vertical rail 58 to move in a corresponding direction along or parallel to the longitudinal X-axis, toward or away from the wall 56.

[0036] Threaded adjustment of the position of vertical adjustment rod 98 (FIGS. 4A, 4B, and 7) causes vertical rail 58 to slide against side surface 70 of horizontal rail 60. A relative angle (θ) is established between sides 62, 64 of vertical rail 58 and walls 45, 47 of guide tracks 44, 46 (close-up view, FIG. 4B). Thus, movement of vertical rail 58 along side surface 70 causes opposite movement of guide tracks 44, 46 toward or away from wall 70, respectively, along or parallel to the vertical Y-axis.

[0037] Cross channels 112, 114 (FIGS. 2, 3A, and 3B) formed in the center plate 18 slidably support the gripping arms 20, 22. The upper channel 112 supports the upper arm 20. The lower channel 114 supports the lower arm 22. A slot 116 extends through the upper channel 112. The longitudinal axis of the slot 116 extends parallel to the longitudinal axis of the upper channel 112, as does the slot in the lower channel 114. The upper and lower channels 112, 114 are angled relative to the longitudinal axis and relative to each other. The upper and lower channels 112, 114 intersect with each other, forming a general X-shaped pattern. The channels 112, 114 are configured to allow the upper and lower gripping arms 20, 22 to move without interfering with each other.

[0038] Gripping fingers 118 extend from center plate 18 between upper and lower channels 112, 114 (FIG. 3B). Gripping fingers 118 cooperate with gripping fingers 119 on upper and lower gripping arms 20, 22 to grip and finely displace workpiece 12 when steady rest 10 is in the clamped position (FIGS. 4-7).

[0039] Another end of center plate 18 has a generally T-shaped opening 124. T-shaped opening 124 receives a similarly shaped end 126 of a ramrod 128 of actuation mechanism 24, as shown in Figure 3B.

[0040] The upper and lower gripper arms 20, 22 each preferably include an elongated upper portion 130 and a shorter lower portion 132 (FIG. 2). The upper and lower portions 130, 132 are preferably angled relative to one another. The gripper fingers 119 extend from the lower portions 130, 132, respectively, toward one another.

[0041] The upper portions 130 of the gripping arms 20, 22 (FIG. 2) have pins or roller guides 134, 135 projecting therefrom and extending into corresponding ones of the upper and lower guide tracks 44, 46. As shown in FIG. 2, the pin 134 of the upper gripping arm 20 extends through the slot 116 and into the lower guide track 46. In this manner, the axial end of the pin 134 slidably engages the groove 54 of the lower guide track 46. The pin 135 of the lower gripping arm 22 extends into the upper guide track 44. The axial end of the pin 135 slidably engages the groove 54 of the upper guide track 44. The pins 134, 135 have bushings 140, 142 that are slidably received in the lower and upper guide tracks 46, 44, respectively (FIG. 3B).

[0042] 2 and 3B, the actuation mechanism 24 includes a housing 144 having a chamber 148, a piston 146, and a ramrod 128. The housing 144 has a flange 145 that is bolted or otherwise attached to the work cover plate 14 and / or the right cover plate 16. The housing 144 and piston 146 define fluid chambers 148, 150 that communicate with upper and lower ports 152, 154, respectively (FIG. 2). The piston 146 is attached to the ramrod 128 and separates the fluid chambers 148, 150. The ports 152, 154 are in fluid communication with a source of actuation fluid (e.g., compressed air or preferably actuation fluid). A fluid control (not shown) is operable to control the flow of actuation fluid into and out of the ports 152, 154 (FIG. 2).

[0043] To move the piston 146 and ramrod 128 away from the workpiece 12, the controller causes hydraulic fluid to flow into the fluid chamber 150 while draining fluid from the other fluid chamber 148. To move the piston 146 and ramrod 128 toward the workpiece 12, the controller causes hydraulic fluid to flow into the fluid chamber 148 while draining fluid from the fluid chamber 150. Because the ramrod 12 is connected to the center plate 18, movement of the piston 146 and ramrod 128 toward or away from the workpiece 12 causes corresponding movement of the center plate 18 toward or away from the workpiece 12.

[0044] Although the actuation mechanism 24 is described above as being a fluid-actuated device, it should be understood that any type of actuator (e.g., an electric motor or other electromechanical device) may be used. Preferably, the fluid is a liquid.

[0045] In conventional steady rests, the working and right cover plates 14, 16 are provided with tapped holes directly. If these holes are damaged, the cover plates themselves often must be replaced, requiring downtime and associated costs. However, with the steady rest system disclosed herein, most repairs (if necessary) are limited to replacing the horizontal and / or threaded adjustment rods 96, 98, their associated lock nuts, the brass blocks with receiving openings defined therein, the roller bearings or bushings 140, 142, and the seals within the cylinder 24. This configuration offers economic advantages over prior approaches.

[0046] As described herein, the vertical threaded adjustment rod 98 is on the left side (as viewed from FIG. 1). In an alternative embodiment, the vertical threaded adjustment rod 98 and associated components may be on the right side.

[0047] Typical steady rest system operation (a) Clamping and releasing the workpiece

[0048] 1-7, the operation of an exemplary embodiment of steady rest system 10 will now be described. As mentioned above, actuation mechanism 24 (FIG. 2) is configured to move center plate 18 and gripping arms 20, 22 between a clamped position in which steady rest 10 grips workpiece 12 and a retracted position in which workpiece 12 is released and gripping arms 20, 22 are retracted into steady rest 10.

[0049] The steady rest 10 allows fine, precise, and predictable adjustments to move the position of the workpiece 12 relative to the steady rest 10 when the workpiece 12 is in the clamped position (see FIGS. 4-7). For example, a 90-degree rotation of the vertical or horizontal adjustment rods 96, 98 can displace the gripped workpiece by 1 micron while holding the workpiece 12 in place, regardless of forces that may be generated by the machining operation or the rotating mass of the workpiece. Such precision is not possible with conventional steady rests.

[0050] To move the steady rest 10 from the retracted position to the clamped position, hydraulic fluid is injected into chamber 148 of the actuation mechanism 24 and hydraulic fluid (if present) is expelled from chamber 150 (FIG. 2), which causes the piston 146 and ramrod 128 to move toward the workpiece 12 (i.e., toward the right relative to the reference frame of FIG. 3B).

[0051] The center plate 18, along with the ramrod 128, moves relative to the work plate 14 and right plate 16 along the longitudinal X-axis (FIG. 3A). As the center plate 18 and gripper arms 20, 22 move toward the clamping position, the pins 134, 135 and bushings 140, 142 slide along the legs 50 of the corresponding guide tracks 44, 46 (FIG. 3B). As the ramrod 128 and center plate 18 continue to move along the longitudinal X-axis toward the workpiece 12, the bushings 140, 142 contact the surfaces 51 of the guide tracks 44, 46, respectively (FIG. 5B).

[0052] Preferably, rails 58, 60 engage one another with a sliding interference fit. In one embodiment, there is a slope of about 1 degree between surfaces 64 and 47, and between surfaces 62 and 45 (close-up, FIG. 7). There is a corresponding slope of about 1 degree between surfaces 56 and 72.

[0053] As the bushings 142, 140 contact the guide tracks 44, 46 and thus the surfaces 62, 64 of the vertical rail 58 (FIGS. 4A and 7), and the ramrod 128 and center plate 18 continue to move along the longitudinal X-axis toward the workpiece 12, the pins 134, 135 (FIGS. 1 and 2) and bushings 140, 142 slide laterally outward along the lower legs 52 of the guide tracks 44, 46. As the roller guides 134, 135 and bushings 140, 142 slide laterally outward along the lower legs 52 of the guide tracks 44, 46, the protruding ends (i.e., lower portions 132) of the gripping arms 20, 22 move toward each other. The direction of movement of the protruding ends is perpendicular to the longitudinal X-axis. The gripping arms 20, 22 slide within the channels 112, 114, respectively, relative to the center plate 18 until the gripping fingers 119 of the gripping arms 20, 22 and the gripping fingers 118 of the center plate 18 contact and securely clamp the workpiece 12. To move the steady rest 10 from the clamped position to the retracted position (FIG. 7), hydraulic fluid is pumped into the chamber 150 of the actuation mechanism 24 and hydraulic fluid, if present, is pumped out of the other chamber 148. This causes the piston 146, ramrod 128, and center plate 18 to move relative to the work plate and right cover plates 14, 16, away from the workpiece 12, after releasing the workpiece 12. This movement is the reverse of the movement of the gripper arms 20, 22 described above. (b) Displacing the workpiece horizontally and vertically.

[0054] 4-7, by turning the adjustment rods 96, 98 (fine threaded at approximately 100 threads per inch), the position to which the clamped workpiece 12 is moved by the gripping fingers 118, 119 can be finely adjusted.

[0055] 6, to move the workpiece 12 horizontally toward the work and right cover plates 14, 16, the user rotates the horizontal adjustment rod 96 in a direction that causes movement of the horizontal rail 60. Such movement occurs in a direction perpendicular to the longitudinal X-axis within the recess 48. The rail engagement spring 90 biases the rails 96, 98 upward.

[0056] A slight inclination angle (θ, approximately 0.92 to 1.08 degrees, preferably 1.00 degrees) is provided between the horizontal rail 60 and the wall surface of the recess 48. As a result, a wedge effect is created that influences and restricts the movement of the guide tracks 44, 46 that contact the rail 58.

[0057] By moving the horizontal guide rail 60 upwardly under the influence of the associated rail engagement spring 90 (FIGS. 5B, 6), the location where the bushings 140, 142 contact the guide tracks 44, 46 also moves outward along the guide tracks 44, 46.

[0058] 6-7 show schematically how rotation of one or both adjustment screws 96, 98 moves the clamped workpiece inward or outward (FIG. 6) and / or upward and downward (FIG. 7).

[0059] For example, a user rotates adjustment rod 98 to move the position where gripping fingers 118, 119 precisely move workpiece 12 vertically. As an example, a 90-degree clockwise displacement raises workpiece 12 by 1 micron. Conversely, a counterclockwise displacement lowers the workpiece by a corresponding amount.

[0060] It should be understood that intermediate adjustments are possible and the displacement is not limited to 90 degree increments or decrements.

[0061] The steady rest 10 may be used to hold a workpiece 12 for grinding operations. However, it should be understood that the principles of the present disclosure are also applicable to steady rests configured for turning operations and / or other machining or manufacturing operations.

[0062] Figures 8A-8B show improvements to the previous design described in the parent patent application. Figure 8A is the original design, and Figure 8B is its revised version. The relationship between rail pin 155 and vertical rail 58 or horizontal rail 60 in Figure 8A could cause rail engagement spring 90 to become trapped within rail spring pocket 157. To solve this problem, rail washer 156 is added (Figure 8B). This eliminates rail spring pocket 157 and changes the relationship between rail pin 155 and vertical rail 58 or horizontal rail 60. Additionally, spring 104 features a higher spring force.

[0063] The foregoing description of the embodiments has been provided for purposes of illustration and description and is not intended to be exhaustive or to limit the present disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment and, where applicable, may be interchangeable and used in selected embodiments even if not specifically shown or described. The same may also be varied in various ways. Such variations are not considered a departure from the present disclosure, and all such modifications are intended to be included within the scope of the present disclosure. [Explanation of symbols]

[0064] 10 Steady Rest System 12 workpieces 14 Work cover plate 16 Right side cover plate 18 Center Plate 20 Upper gripping arm 22 Lower gripping arm 24 Operating mechanism 26 Opening 28 Upper sliding plate 30 Lower sliding plate 32 Opening 40 volts 42 Track engagement spring 43 Cavity 44 Upper guide track 45 Upper truck sidewall 46 Lower guide track 47 Lower truck sidewall 48 Rail recess 49 Inner wall of upper guide track 50 Long, slender upper leg 51 Inner wall of lower guide track 52 Short lower leg 54 Groove 56 Upper wall 58 Vertical Rail 60 horizontal rail 62 Upper side of vertical rail 64 Underside of vertical rail 70 Upper side of horizontal rail 72 Underside of horizontal rail 90 Rail engagement spring 92 threaded opening 94 threaded opening 96 Horizontal screw adjustment rod 98 Vertical screw adjustment rod 100 96 shaft end 102 98 shaft end 104 Rail engagement spring 106 48 Second Wall 108 18th page 1 110 18th page 2 112 Upper Cross Channel 114 Lower Cross Channel 116 Slots 118 Grasping Fingers 119 Grasping Finger Arm 124 T-shaped opening 126 128 T-shaped end 128 24 Ramrod 130 elongated first portion of gripping arm 132 Short second part of grasping arm 134 pins 135 pins 140 Bushing 142 Bushing 144 Housing 145 flange 146 Piston 148 First liquid chamber 150 Second liquid chamber Port 152 154 port 155 rail pin 156 Rail washer 157 Rail Spring Pocket

Claims

1. 1. A steady rest for gripping and fine positioning a workpiece, comprising: a work cover plate and a right cover plate; a center plate disposed between the working cover plate and the right cover plate and configured to slide therebetween, the center plate having upper and lower cross channels for engaging upper and lower gripping arms, the gripping arms being movable relative to the working cover plate and the right cover plate between a clamped position and a retracted position, the center plate also having a rail recess and a pair of cavities that respectively house upper and lower guide tracks and track engagement springs that respectively bias the guide tracks; a tapered horizontal rail located within the rail recess configured to horizontally displace the workpiece; a vertical rail positioned within the rail recess, the vertical rail having a flat surface facing the horizontal rail and an opposing surface having an inclined portion meeting at both ends of the flat intermediate portion, the vertical rail being configured to vertically displace the workpiece; The horizontal and vertical rails contact the rail recesses and each other when the gripping arms are positioned, and are movable relative to each other by the guidance of rail pins and rail washers extending along channels defined in the horizontal and vertical rails, thereby avoiding binding and enabling adjustment of the relative positions of the working cover plate and right cover plate when the upper and lower gripping arms are in the clamping position and the workpiece is clamped, a steady rest.

2. 2. The steady rest of claim 1, further comprising horizontal and vertical threaded adjustment rods threadably received in openings in the work cover plate and extending into the rail recesses, the horizontal threaded adjustment rod abutting the horizontal rail and being rotatable to adjust the position of the horizontal rail, and the vertical threaded adjustment rod abutting the vertical rail and being rotatable to adjust the position of the vertical rail.

3. 3. The steady rest of claim 2, further comprising rail engagement springs that bias the horizontal and vertical rails into contact with the upper walls of the rail recesses, the track engagement springs and rail engagement springs having common mechanical characteristics.

4. 2. The steady rest of claim 1, wherein the vertical rail has a flat surface that slidably engages the horizontal rail and an opposing surface having an inclined surface inclined at an angle θ, the angle θ being between 0.92 degrees and 1.08 degrees.

5. 2. The steady rest of claim 1, wherein the horizontal rail has a flat surface that slidably engages the vertical rail and an opposing surface that slidably engages a wall of the rail recess, the flat surface and the wall being inclined at an angle θ, the angle θ being between 0.92 degrees and 1.08 degrees.

6. 2. The steady rest of claim 1, wherein the upper and lower gripping arms have pins extending therefrom that are slidably received in the upper and lower guide tracks located within the cavities in the work cover plate.

7. 7. The steady rest of claim 6, wherein the upper and lower guide tracks each have an elongated leg and a shorter leg extending therefrom.

8. 10. The steady rest of claim 1, further comprising a housing having a plurality of fluid chambers and an actuation mechanism including a piston and a ramrod disposed between the chambers, the housing being secured to the work cover plate and / or the right cover plate.

9. 9. The steady rest of claim 8, wherein the housing and the piston define the plurality of fluid chambers that communicate with upper and lower ports, respectively, the ports being in fluid communication with a source of hydraulic fluid and a fluid control device capable of controlling the flow of the hydraulic fluid into and out of the ports.

10. 10. The steady rest of claim 1, wherein a 90 degree rotation of the vertical or horizontal adjustment rod displaces the gripped workpiece by 1 micron while holding the workpiece in place despite forces that may be generated by machining operations and the rotating mass of the workpiece.

11. 10. A method for displacing the steady rest of claim 1 from a retracted position to a clamped position, comprising: injecting an actuating fluid into a chamber of the actuating mechanism, thereby moving a piston toward the workpiece; moving the center plate along an axis relative to the work plate and the right side plate under the influence of the actuation mechanism; and sliding pins and bushings along corresponding legs of the guide tracks as the center plate and gripping arms move toward a clamping position, causing the bushings to contact surfaces of the guide tracks and the pins and bushings to slide laterally outward along lower legs of the guide tracks, thereby causing the protruding ends of the gripping arms to move toward each other and contact and securely clamp the workpiece.

12. 10. A method for horizontally moving a clamped workpiece using the steady rest of claim 1, comprising: When the horizontal adjustment rod is rotated by the horizontal adjustment screw, the horizontal rail moves under the influence of the rail engagement spring, but such movement is constrained by the inclination angle (θ, approximately 0.92 to 1.08 degrees) between the horizontal rail and the wall surface of the rail recess so that a wedge effect influences and restricts the movement of the guide track contacting the rail; When the horizontal guide rail is moved upward under the influence of an associated rail engagement spring, the position along the guide track where the bushing contacts the guide track also moves outward, thereby displacing the workpiece horizontally, and as a result, rotation of the horizontal adjustment screw displaces the clamped workpiece inward or outward.

13. 10. A method for vertically moving a clamped workpiece using the steady rest of claim 1, comprising: When the vertical adjustment rod is rotated by the vertical adjustment screw, the vertical rail moves under the influence of the rail engagement spring, but such movement is constrained by the inclination angle (θ, approximately 0.92 to 1.08 degrees) between the vertical rail and the wall surface of the rail recess so that a wedge effect influences and restricts the movement of the guide track in contact with the rail; When the vertical rail is moved upward under the influence of an associated rail-engaging spring, the location along the guide track where the bushing contacts the guide track also moves vertically, thereby displacing the workpiece vertically.

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