Locking device, clamp slider and medical device

Abstract

Provided is a locking device etc. that can accurately switch between locked and unlocked states and easily maintain the locked state. The locking device is provided on a clamp slider 1 that is guided using at least one guide rail R and includes: a locking section (21) that abuts against the guide rail to fix the movement of the clamp slider; a fixing force section (40) that applies a fixing force to make the locking section abut against the guide rail; a first rolling element (22) that is arranged between the locking section and the fixing force section and is capable of transmitting the fixing force from the fixing force section to the locking section; a second rolling element (23) that is arranged between the first rolling element and the fixing force section and abuts against the first rolling element and moves in a direction along the guide rail to lock or unlock the movement of the clamp slider; and a third rolling element (24) that is arranged between the second rolling element and the fixing force section and abuts against the second rolling element to transmit the fixing force from the fixing force section to the second rolling element.

Description

Technical Field

[0001] The present invention relates to a locking device, a clamp slider, and a medical device.

Background Art

[0002] Medical devices such as operating tables used in operating rooms or treatment rooms have a locking device that locks and unlocks the sliding of a table on which a patient is placed according to the situation of a medical procedure. For example, Patent Document 1 discloses a braking and clamping device provided on a carriage guided by a guide rail, which has at least one friction locking device operable via a slide wedge transmission device. The friction locking device has at least one pressing member supported in a housing and capable of being pressed against the guide rail. The slide wedge transmission device is moved in one direction using at least spring force to load the friction locking device, and is moved in the reverse direction using pressure by air force or hydraulic pressure by at least one piston to release the load. The slide wedge of the slide wedge transmission device acts on the pressing member via at least one rolling element, and the rolling element is supported in a cage. A braking and clamping device is disclosed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, due to the angle of the sliding wedge, the pressing member is pressed against the guide rail. If the wedge angle is small, the wedge may jam in the locked state, making it impossible to release. On the other hand, if the wedge angle is large, the reaction force is also large even in the locked state, requiring the wedge to be constantly and strongly pressed in the sliding direction. Therefore, it was difficult to simultaneously satisfy the requirements of easy switching between locking and unlocking, and easy maintenance of the locked state.

[0005] Therefore, the present invention has been made in view of the above-mentioned problems, and one example of the problem it addresses is to provide a locking device that can accurately switch between locking and unlocking and that can easily maintain the locked state. [Means for solving the problem]

[0006] To solve the above problems, the invention described in claim 1 is a locking device provided on a clamp slider guided by at least one guide rail, comprising: a locking part that abuts against the guide rail to fix the movement of the clamp slider; a fixing force part that applies a fixing force to bring the locking part into contact with the guide rail; a first rolling element disposed between the locking part and the fixing force part and capable of transmitting the fixing force from the fixing force part to the locking part; a second rolling element disposed between the first rolling element and the fixing force part, abutting against the first rolling element, and moving in a direction along the guide rail to lock or unlock the movement of the clamp slider; and a third rolling element disposed between the second rolling element and the fixing force part, abutting against the second rolling element, and capable of transmitting the fixing force from the fixing force part to the second rolling element.

[0007] Furthermore, the invention described in claim 2 is characterized in that, in the locking device described in claim 1, the movement of the clamp slider is locked by the first rolling element, the second rolling element, and the third rolling element being in contact with each other and aligned in a line from the fixing force portion toward the locking portion.

[0008] Furthermore, the invention described in claim 3 is characterized in that, in the locking device described in claim 2, the state in which the elements are arranged in a row is such that the second rolling element is moved in a direction along the guide rail and acts in a direction that pushes it between the first rolling element and the third rolling element, and the arrangement is such that the centers of the first rolling element, the second rolling element and the third rolling element are not aligned in a straight line.

[0009] Furthermore, the invention described in claim 4 is characterized in that, in the locking device described in claim 2, a first piston rod acts in a direction to push the second rolling element between the first rolling element and the third rolling element so that they are aligned in a row, and a second piston rod is located opposite the first piston rod and moves the second rolling element away from the aligned state.

[0010] Furthermore, the invention described in claim 5 is characterized in that, in the locking device described in claim 4, the first piston rod has contact surfaces that contact the first rolling element, the second rolling element, and the third rolling element, and the contact surface with respect to the second rolling element protrudes more than the other contact surfaces.

[0011] Furthermore, the invention described in claim 6 is characterized in that, in the locking device described in claim 4, it comprises a cage for housing the first rolling element, the second rolling element, and the third rolling element, the cage having an opening through which the first piston rod can pass, and the cage having an inner surface on the side opposite to the first piston rod that can contact each rolling element in a row.

[0012] Furthermore, the invention described in claim 7 is a locking device according to claim 5, comprising a cage for housing the first rolling element, the second rolling element, and the third rolling element, wherein the cage has an opening through which the first piston rod can pass, and the cage has an inner surface on the side opposite to the first piston rod that can contact each rolling element in the row, and the inner surface has a recess corresponding to the second rolling element.

[0013] Furthermore, the invention described in claim 8 is characterized in that, in the locking device described in claim 1, the second rolling element is moved in a direction along the guide rail by hydraulic pressure.

[0014] Furthermore, the invention described in claim 9 is characterized in that, in the locking device described in claim 1, the fixing force part generates the fixing force by a spring mechanism.

[0015] Furthermore, the invention described in claim 10 is characterized in that, in the locking device described in claim 1, the first rolling element, the second rolling element, and the third rolling element are cylindrical.

[0016] Furthermore, the invention described in claim 11 is characterized by comprising: a groove portion of a housing through which a guide rail is guided; a lock portion protruding into the space within the groove portion and contacting the guide rail to fix the movement of the clamp slider; a fixing force portion that applies a fixing force to bring the lock portion into contact with the guide rail; a first rolling element disposed between the lock portion and the fixing force portion and capable of transmitting the fixing force from the fixing force portion to the lock portion; a second rolling element disposed between the first rolling element and the fixing force portion, contacting the first rolling element, and moving in a direction along the guide rail to lock or unlock the movement of the clamp slider; and a third rolling element disposed between the second rolling element and the fixing force portion, contacting the second rolling element, and capable of transmitting the fixing force from the fixing force portion to the second rolling element.

[0017] Furthermore, the invention described in claim 12 is a medical device comprising a table movable with respect to a base, a guide rail defining the direction of movement of the table, and a clamp slider guided by the guide rail and locking its movement, wherein the clamp slider has a locking part that abuts against the guide rail and fixes the movement of the clamp slider, a fixing force part that applies a fixing force to bring the locking part into contact with the guide rail, a first rolling element disposed between the locking part and the fixing force part and capable of transmitting the fixing force from the fixing force part to the locking part, a second rolling element disposed between the first rolling element and the fixing force part, abutting against the first rolling element, and moving in a direction along the guide rail to lock or unlock the movement of the clamp slider, and a third rolling element disposed between the second rolling element and the fixing force part, abutting against the second rolling element, and capable of transmitting the fixing force from the fixing force part to the second rolling element. [Effects of the Invention]

[0018] According to the present invention, a first rolling element, a second rolling element, and a third rolling element are arranged in order between a locking element that contacts a guide rail to fix the movement of the clamp slider and a fixing force element that applies a fixing force to contact the locking element with the guide rail. In this configuration, the second rolling element enters between the first and third rolling elements, the fixing force from the fixing force element is transmitted to the locking element, locking the movement of the clamp slider. Conversely, the second rolling element disengages, releasing the lock. This allows for precise switching between locking and unlocking, and makes it easy to maintain the locked state. [Brief explanation of the drawing]

[0019] [Figure 1] This is a perspective view showing an example of the internal configuration of the clamp slider according to this embodiment. [Figure 2] Figure 1 is a perspective view showing an example of the external configuration of the clamp slider. [Figure 3] Figure 1 is a perspective view showing an example of the external configuration of the clamp slider. [Figure 4]It is a cross-sectional view showing an example of the cross-section of the clamp slider in FIG. 3. [Figure 5] It is a perspective cross-sectional view showing an example of the cross-section of the clamp slider in FIG. 3. [Figure 6] It is a perspective view showing an example of the first piston rod in FIG. 1. [Figure 7A] It is a perspective view showing an example of the cage in FIG. 1. [Figure 7B] It is a perspective view showing an example of the cage in FIG. 1. [Figure 8] It is a perspective view showing an example of the arrangement of the cage and each member in FIG. 1. [Figure 9] It is a cross-sectional view showing an example of the arrangement of the cage and each member in FIG. 1. [Figure 10A] It is a cross-sectional view showing an example of the operation of the clamp slider. [Figure 10B] It is a cross-sectional view showing an example of the operation of the clamp slider. [Figure 11] It is a perspective view showing an example of the appearance of the operating table using the clamp slider in FIG. 1. [Figure 12] It is a perspective view showing an example of the horizontal slide portion of the operating table in FIG. 11. [Figure 13] It is a perspective view showing an example of the elevating portion in the base of the operating table in FIG. 11.

Mode for Carrying Out the Invention

[0020] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The embodiments described below are embodiments when the present invention is applied to a clamp slider or the like.

[0021] [1. Configuration and Functional Outline of Clamp Slider and Each Part] (1.1 Configuration and Functional Outline of Clamp Slider)

[0022] First, the configuration and outline functions of the clamp slider according to an embodiment of the present invention will be described with reference to FIGS. 1 to 6.

[0023] Figure 1 is a perspective view showing an example of the schematic configuration of a clamp slider according to this embodiment. Figures 2 and 3 are perspective views showing an example of the external configuration of the clamp slider of Figure 1. Figure 4 is a cross-sectional view showing an example of a cross-section along line AA of the clamp slider 1 of Figure 3. Figure 5 is a perspective view showing an example of a cross-sectional view along line AA of the clamp slider 1 of Figure 3. Figure 6 is a perspective view showing an example of the first piston rod of the clamp slider.

[0024] As shown in Figure 1, the clamp slider 1 according to this embodiment includes a housing portion 10 that is slidably installed on a guide rail R, a lock / release portion 20 that locks and unlocks the movement of the clamp slider 1 on the guide rail R, hydraulic portions 30 and 35 that lock and unlock the lock / release portion 20 by hydraulic pressure, a spring portion 40 that applies a fixing force to contact the guide rail, and a cage 50 that houses some of the components constituting the lock / release portion 20.

[0025] Furthermore, the locking mechanism for a clamp slider guided by a guide rail is comprised of at least the lock / release section 20 and the spring section 40. The locking mechanism may also include hydraulic sections 30, 35 and a cage 50.

[0026] The clamp slider 1 is fixed to the object to be slid relative to the guide rail R with bolts or the like, and locks or unlocks the sliding movement of the object. For example, when the clamp slider 1 is installed on an operating table, it locks or unlocks the sliding movement of the operating table's table. The locking device of this invention can also be applied to objects that slide along guide rails, such as transport devices for liquid crystals and semiconductors, and machine tools.

[0027] As shown in Figures 1 to 4, the housing portion 10 has a groove portion 11 for sliding the guide rail R, a through hole 12 for housing the hydraulic portion 30, a through hole 13 for housing the hydraulic portion 35, a housing space 14 for housing the cage 50, a through hole 15 for housing the pressing member 21 of the lock / release portion 20, and a through hole 16 for housing the spring portion 40. The material of the housing portion 10 is a metal such as alloy steel, carbon steel, copper, copper alloy, cast iron, aluminum, or stainless steel.

[0028] The groove 11 is formed in a direction D1 along the guide rail R, and is sized to accommodate the guide rail R.

[0029] The through-hole 12 is cylindrical in shape, having a central axis C1 in the direction D1 along the guide rail R, and is sized to accommodate the piston and other components of the hydraulic section 30. The through-hole 12 has an opening that opens to the outside of the housing section 10 and communicates with the housing space 14 via the connection hole 14a.

[0030] The through-hole 13 is cylindrical in shape, having a central axis C1 in the direction D1 along the guide rail R, and is sized to accommodate the piston and other components of the hydraulic section 35. The through-hole 13 has an opening that opens to the outside of the housing section 10 and communicates with the housing space 14 via the connection hole 14b.

[0031] The containment space 14 is formed to a size that can accommodate a cage 50, etc.

[0032] The through-hole 15 is cylindrical in shape, having a central axis C2 perpendicular to the central axis C1, and is sized to accommodate the pressing member 21. The through-hole 15 has an opening that opens into the groove 11 of the housing portion 10 and communicates with the accommodating space 14.

[0033] The through-hole 16 is cylindrical with a central axis C2 and is sized to accommodate the disc springs and spring piston of the spring section 40. The through-hole 16 has an opening that opens to the outside of the housing section 10 and communicates with the housing space 14. The outer opening of the through-hole 16 is fitted with a spring housing section 42a that can accommodate stacked disc springs 42 by a screw structure.

[0034] As shown in Figure 2, the housing portion 10 has a mounting member 5 that is attached to the object to be slid relative to the guide rail R with bolts or the like. A recess is formed on the surface of the housing portion 10 opposite the groove portion 11, and the mounting member 5 is embedded in it. The mounting member 5 is fixed to the housing portion 10 with bolts or the like at its center. Bolt holes for attachment to the object are formed at four locations on the mounting member 5.

[0035] Note that the movement of the clamp slider 1 and the guide rail R is relative. For example, the object to be mounted by the mounting member 5 of the clamp slider 1 may be guided and moved along the guide rail R installed on a base or the like, or at least one guide rail R attached to a table may slide along the clamp slider 1 attached to the object to be mounted on a base or the like.

[0036] As shown in Figures 1, 4, and 5, the lock / release section 20 includes a pressing member 21 that contacts the guide rail R, a first rolling element 22 capable of transmitting a fixing force from the spring section 40 to the pressing member 21, a second rolling element 23 that contacts the first rolling element 22 and moves in a direction D1 along the guide rail R to fix or release the movement of the clamp slider 1, and a rolling element 24 that contacts the second rolling element 23 and is capable of transmitting a fixing force from the spring section 40 to the second rolling element 23. The first rolling element 22, the second rolling element 23, and the third rolling element 24 form a fixing force transmission section that transmits the fixing force from the spring section 40, which is a fixing force section, to the pressing member 21, which is an example of a lock section.

[0037] The pressing member 21 is an example of a locking mechanism that contacts the guide rail R to fix the movement of the clamp slider 1. The pressing member 21 is made of a metal such as carbon steel, alloy steel, steel, stainless steel, or copper alloy. The contact portion of the pressing member 21 with the guide rail R functions as a brake shoe.

[0038] The pressing member 21 is substantially cylindrical and has a flange portion 21a. The diameter of the flange portion 21a is larger than the diameter of the through hole 15 and is located on the side of the housing space 14, preventing the pressing member 21 from coming out of the through hole 15 into the groove portion 11. An elastic ring member is inserted in the part of the flange portion 21a that corresponds to the inner wall of the housing space 14. This ring member abuts against the inner wall of the housing space 14, which is around the opening on the through hole 15 side of the housing space 14. This ring member biases the pressing member 21 toward the first rolling element 22. Therefore, even if the fixing force from the first rolling element 22 loosens in the unlocked state, the contact between the pressing member 21 and the first rolling element 22 does not separate. As a result, rattle does not occur. The material of the ring member is preferably an elastic material such as urethane or rubber. The ring member may also be an elastic material such as a metal disc spring. The ring component is optional.

[0039] The first rolling element 22 has a cylindrical shape. The central axis of the cylindrical first rolling element 22 is perpendicular to the central axes C1 and C2. The first rolling element 22 is positioned between the pressing member 21 and the spring portion 40. The first rolling element 22 is positioned between the pressing member 21 and the second rolling element 23, in contact with each other. The cylindrical surface of the first rolling element 22 is in contact with the bottom surface of the pressing member 21 on the flange portion 21a side. The cylindrical surface of the first rolling element 22 is in contact with the cylindrical surface of the second rolling element 23. The first rolling element 22 is also capable of rolling into contact with the pressing member 21 and the second rolling element 23.

[0040] The first rolling element 22 is an example of a first rolling element that is positioned between the locking part and the fixing force part and is capable of transmitting the fixing force from the fixing force part to the locking part.

[0041] The second rolling element 23 has a cylindrical shape. The central axis of the cylindrical second rolling element 23 is perpendicular to the central axes C1 and C2. The second rolling element 23 is positioned between the first rolling element 22 and the spring portion 40. The second rolling element 23 is positioned between the first rolling element 22 and the third rolling element 24, with their cylindrical surfaces in contact with each other. The second rolling element 23 is also capable of rolling into contact with the first rolling element 22 and the third rolling element 24. The second rolling element 23 contacts the first rolling element 22 and moves in a direction along the guide rail R, thereby fixing or releasing the movement of the clamp slider 1.

[0042] The second rolling element 23 is an example of a second rolling element that is positioned between the first rolling element and the fixed force element, contacts the first rolling element, and moves in a direction along the guide rail to lock or unlock the movement of the clamp slider.

[0043] The shape of the third rolling element 24 is cylindrical. The central axis of the cylindrical third rolling element 24 is perpendicular to the central axes C1 and C2. The third rolling element 24 is positioned in contact with each other between the second rolling element 23 and the spring portion 40. The cylindrical surface of the third rolling element 24 is in contact with the cylindrical surface of the second rolling element 23. The cylindrical surface of the third rolling element 24 is in contact with the bottom surface of the spring piston 41 of the spring portion 40. The third rolling element 24 is also capable of rolling into contact with the bottom surfaces of the second rolling element 23 and the second spring piston 41. The third rolling element 24 is in contact with the second rolling element 23 and is capable of transmitting the fixing force from the spring portion 40 to the second rolling element 23.

[0044] The third rolling element 24 is an example of a third rolling element that is positioned between the second rolling element and the fixed force unit, contacts the second rolling element, and is capable of transmitting the fixed force from the fixed force unit to the second rolling element.

[0045] The central axes of the first rolling element 22, the second rolling element 23, and the third rolling element 24 are parallel to each other.

[0046] The first rolling element 22, the second rolling element 23, and the third rolling element 24 are preferably made of materials that exhibit low wear, such as alloy steel, carbon steel, stainless steel, or ceramic. The first rolling element 22, the second rolling element 23, and the third rolling element 24 are preferably cylindrical, but may also be spherical.

[0047] The hydraulic unit 30 includes a lid member 31 having a packing mechanism to prevent hydraulic fluid leakage, a piston 32 that slides in the direction of the central axis C1 by the hydraulic fluid, and a piston rod 33 connected to the piston 32 in the direction of the central axis C1.

[0048] The cover member 31 is fixed so as to block one of the through holes 12. The cover member 31 has a supply port for supplying hydraulic fluid. The hydraulic unit 30 is connected to a hydraulic pump (not shown) via the cover member 31.

[0049] The piston 32 has a fitting hole formed in the center of one side of the piston 32, which engages with one end of the piston rod 33.

[0050] The materials used for the piston 32 are steel, stainless steel, aluminum, and copper alloy.

[0051] The piston 32 is fitted with an elastomer ring made of rubber or similar material to prevent hydraulic fluid from leaking out. The piston 32 slides within the through hole 12. To facilitate the sliding of the piston 32 and prevent hydraulic fluid leakage, a tube-shaped component is inserted between the inner wall of the through hole 12 and the piston 32 to improve surface roughness and precision. The material of the tube-shaped component can be steel, carbon steel, alloy steel, stainless steel, copper alloy, etc.

[0052] As shown in Figure 6, the piston rod 33 has a contact portion 33a that abuts against the second rolling element 23, a contact portion 33b that abuts against the first rolling element 22 and the third rolling element 24, a fitting portion 33c that fits into the fitting hole of the piston rod 33, and four recesses 33d that are partially cut out from the contact portion 33b side in the direction of the central axis C3. The contact portion 33a protrudes slightly from the contact portion 33b toward the second rolling element 23 in the sliding direction of the piston rod 33. This slight protrusion is preferably 1% to 5% relative to the diameter of the second rolling element 23. Since this slight protrusion corresponds to the recess on the surface 55a of the inner surface 55 of the cage 50, which will be described later, it is preferable that it be equivalent to the recess on the surface 55a of the inner surface 55. Note that the slight protrusion may be greater than 5%, but the fixing force will decrease.

[0053] The piston rod 33 is an example of a first piston rod that acts in a direction to push the second rolling element between the first and third rolling elements so that they are aligned in a line. The piston rod 33 is an example of a first piston rod that has contact surfaces that come into contact with the first, second, and third rolling elements, and the contact surface with respect to the second rolling element protrudes more than the other contact surfaces.

[0054] As shown in Figures 4 and 5, the piston rod 33 is installed in the connection hole 14a through the through hole 12 such that its central axis C3 coincides with the central axis C1. The contact portions 33a and 33b are located within the housing space 14. The piston rod 33 slides within the connection hole 14a.

[0055] The material of the piston rod 33 can be steel, carbon steel, alloy steel, stainless steel, copper alloy, etc.

[0056] The hydraulic section 35 includes a lid member 36 having a packing mechanism to prevent leakage of hydraulic fluid, a piston 37 that slides in the direction of the central axis C1 by the hydraulic fluid, and a piston rod 38 connected to the piston 37 in the direction of the central axis C1.

[0057] The cover member 36 is fixed so as to block one of the through holes 13. The cover member 36 has a supply port for supplying hydraulic fluid. The hydraulic section 35 is connected to a hydraulic pump (not shown) via the cover member 36.

[0058] The piston 37 has a fitting hole formed in the center of one side of the piston 37, which engages with one end of the piston rod 38. The material of the piston 37 is the same as that of the piston 32. The piston 37 slides within the through hole 13. To facilitate the sliding of the piston 32 and to prevent leakage of hydraulic fluid, a tube-shaped member is inserted between the inner wall of the through hole 13 and the piston 37, similar to the case of the through hole 12.

[0059] The piston rod 38 has a contact portion that abuts against the second rolling element 23 and a main body portion that fits into the fitting hole of the piston 37. The piston rod 38 has a cylindrical main body portion with a smaller diameter than the piston rod 33 in order to abut only against the second rolling element 23, and the contact portion of the piston rod 38 is shaped like a thin rectangular prism. One end of the cylindrical main body portion of the piston rod 38 serves as the fitting portion.

[0060] The piston rod 38 is located opposite the first piston rod and is an example of a second piston rod that displaces the second rolling elements from their aligned state.

[0061] As shown in Figures 4 and 5, the piston rod 38 is installed in the connecting hole 14b through the through hole 13 so that its axis coincides with the central axis C1. The contact portion of the piston rod 38 is located within the housing space 14. The body of the piston rod 38 slides within the connecting hole 14b. The material of the piston rod 38 is the same as that of the piston rod 33.

[0062] The hydraulic units 30 and 35 cause the piston rods 33 and 38 to move in opposite directions in conjunction. That is, when the piston rod 33 protrudes toward the second rolling element 23, the piston rod 38 retracts toward the cover member 36. When the piston rod 38 protrudes toward the second rolling element 23, the piston rod 33 retracts toward the cover member 31. In this way, the hydraulic units 30 and 35 move the second rolling element 23 along the guide rail R by hydraulic pressure.

[0063] The spring section 40 includes a spring piston 41 that slides in the direction of the central axis C2, a plurality of disc springs 42 that generate a fixing force toward the pressing member 21 relative to the spring piston 41, and a lock / unlock sensor section 43 for detecting locking and unlocking.

[0064] The spring piston 41 has a contact portion 41a that contacts the third rolling element 24 and a spring shaft portion 41b that passes through the holes of the stacked disc springs 42. The shape of the spring piston 41 is that of stacked cylinders of different diameters, with the diameter of the contact portion 41a being larger than that of the spring shaft portion 41b. The material of the spring piston 41 is the same as that of the piston rod 33, etc.

[0065] The disc spring 42 is made of steel such as carbon steel, alloy steel, or stainless steel. The disc spring 42 and spring piston 41 are housed in the spring housing 42a. The disc spring 42 mainly generates a fixing force that causes it to contact the guide rail R. A coil spring may be used instead of the disc spring 42.

[0066] Thus, the spring section 40 is an example of a fixing force section that applies a fixing force to bring the pressing member 21, which is an example of a locking section, into contact with the guide rail R. The spring section 40 is an example of a fixing force section that generates a fixing force by a spring mechanism.

[0067] The lock / release sensor unit 43 is formed from a cylindrical metal member. The lock / release sensor unit 43 is inserted into a cylindrical hole in the housing unit 43a and displaces in accordance with the movement of the spring piston 41, displacing in the direction of the central axis C2. A displacement sensor (not shown) that detects the displacement in the direction of the central axis C2 is installed on a protruding part of the lock / release sensor unit 43. The housing unit 43a is fixed to the spring housing unit 42a by four bolts. This displacement sensor is, for example, a switch that turns ON and OFF in accordance with the movement of the lock / release sensor unit 43 in the direction of the central axis C2. In the locked state, the lock / release sensor unit 43 presses the switch, making electrical contact and turning the switch ON. When unlocked, the lock / release sensor unit 43 retracts, making electrical contact and turning the switch OFF. The position of the displacement sensor is adjusted so that it operates in this manner.

[0068] (1.2 Configuration and Functional Overview of Cage 50) Next, the configuration and function of cage 50 will be explained using diagrams. Figures 7A and 7B are perspective views showing an example of the cage in Figure 1.

[0069] As shown in Figures 7A and 7B, the cage 50 has an opening 51 for the first rolling element 22, an opening 52 for the third rolling element 24, an opening 53 for the piston rod 33, and an opening 54 for the piston rod 38. The opening 51 is formed on the end face 50a of one bottom surface of the cylindrical cage 50, and the opening 52 is formed on the end face 50b of the other bottom surface of the cylindrical cage 50. The openings 53 and 54 are formed on the cylindrical surface of the cylindrical cage 50.

[0070] The cage 50 has openings 51, 52, 53, 54 and an internal space formed within it so that the first rolling element 22 and the third rolling element 24 can be displaced in the direction of the central axis C4, and the piston rods 33, 38 and the second rolling element 23 can be displaced in the sliding direction of the piston rod. Examples of materials for the cage 50 include alloy steel, carbon steel, and stainless steel.

[0071] The shape of opening 51 is rectangular, which is the cross-sectional shape of the first rolling element 22 in the direction of its long axis. The shape of opening 52 is rectangular, which is the cross-sectional shape of the third rolling element 24 in the direction of its long axis. The shape of opening 53 is such that the contact portions 33a and 33b of the piston rod 33 can slide. The shape of opening 54 is such that the contact portion of the piston rod 38 can slide.

[0072] The cage 50 houses the first rolling element 22, the second rolling element 23, the third rolling element 24, the piston rod 33, and the piston rod 38. The cage 50 houses these rolling elements in a way that maintains a predetermined arrangement. For example, the cage 50 acts to stabilize the arrangement of the first rolling element 22, the second rolling element 23, and the third rolling element 24 in both the locked and unlocked states. The cage 50 also acts to ensure that changes in arrangement occur smoothly during transitions between the locked and unlocked states. The cage 50 is installed within the housing space 14 such that its central axis C4 is parallel to the central axis C1. The cage 50 is housed within the housing space 14 so as to be displaceable in the direction of the central axis C1.

[0073] Thus, cage 50 is an example of a cage that houses the first rolling element, the second rolling element, and the third rolling element. Also, opening 53 is an example of an opening through which the first piston rod can pass.

[0074] The cage 50 has an internal surface 55 parallel to the central axis C4. The internal surface 55 has a surface 55a to which the second rolling element 23 can abut, and a surface 55b to which the first rolling element 22 and the third rolling element 24 can slide in the direction of the central axis C4. Surface 55a is formed slightly closer to the opening 54 than surface 55b, and is a recessed shape of the internal surface 55. When locked, the second rolling element 23 can be positioned slightly closer to the opening 54 than the first rolling element 22 and the third rolling element 24. The recessed surface 55a of the internal surface 55 corresponds to the protrusion of the protruding contact portion 33a of the piston rod 33. This slight recess is preferably 1% to 5% of the diameter of the second rolling element 23. Since it corresponds to the contact portion 33a of the piston rod 33, it is preferable that the protrusion of the contact portion 33a relative to the contact portion 33b of the piston rod 33 is equivalent. However, this slight recess may be greater than 5%, but the fixing force will decrease.

[0075] Thus, the inner surface 55 is an example of an inner surface that can contact each rolling element in a line on the opposite side of the first piston rod. The inner surface 55 is an example of an inner surface that has a recess corresponding to the second rolling element.

[0076] (1.3 Arrangement of Cage 50 and each component) Next, the arrangement of the cage 50 and the hydraulic sections 30, 35 and the lock / release section 20 will be explained using Figures 8 and 9. Figure 8 is a perspective view showing an example of the arrangement of the cage 50 and the components. Figure 9 is a cross-sectional view taken along line B-B in Figure 8, showing an example of the arrangement of the cage 50 and the components.

[0077] Figures 8 and 9 show the locked state. As shown in Figures 8 and 9, the piston rod 33, rolling elements 22, 23, and 24, and piston rod 38 are arranged in direction D1 along the guide rail R. The rolling elements 22, 23, and 24, and parts of the piston rods 33 and 38 are housed in the cage 50. In the locked state, the first rolling element 22, the second rolling element 23, and the third rolling element 24 are arranged in an almost straight line perpendicular to direction D1.

[0078] In the locked state, the protruding contact portion 33a of the piston rod 33 positions the second rolling element 23 closer to the piston rod 38 than the first rolling element 22 and the third rolling element 24. A portion of the surface 55a of the cage 50 supports the second rolling element 23. The first rolling element 22 and the third rolling element 24 are sandwiched between the contact portion 33b of the piston rod 33 and the surface 55b of the cage 50.

[0079] The piston rod 33 and the cage 50 are slidable relative to each other in direction D1 through the opening 53 of the cage 50. The piston rod 38 and the cage 50 are slidable relative to each other in direction D1 through the opening 52 of the cage 50.

[0080] A portion of the first rolling element 22 protrudes from its end face 50a in the direction of the central axis C2 from the opening 51 of the cage 50, thereby applying a fixing force to the pressing member 21. A portion of the third rolling element 24 protrudes from its end face 50b in the direction of the central axis C2 from the opening 54 of the cage 50, and is in contact with the contact portion 41a of the spring piston 41.

[0081] When the first rolling element 22, the second rolling element 23, and the third rolling element 24 are aligned in a nearly straight line, the locking force from the spring piston 41 is applied directly to the guide rail R, resulting in a locked state. In other words, the first rolling element 22, the second rolling element 23, and the third rolling element 24 are in contact with each other and are aligned in a line from the spring portion 40 toward the pressing member 21.

[0082] Furthermore, with the second rolling element 23 slightly offset toward the piston rod 38, the first rolling element 22, the second rolling element 23, and the third rolling element 24 are sandwiched and fixed inside the cage 50 by the contact portions 33a and 33b of the piston rod 33 and the surfaces 55a and 55b of the inner surface 55 of the cage 50. As a result, the locked state remains stable even with external forces such as vibration. Specifically, the contact portion 33a of the piston rod 33 moves the second rolling element 23 in a direction along the guide rail R, pushing it between the first rolling element 22 and the third rolling element 24, causing the centers of the first rolling element 22, the second rolling element 23, and the third rolling element 24 to be in a state beyond a straight line alignment. This slight offset is preferably 1% to 5% relative to the diameter of the second rolling element 23. Note that this slight deviation can be greater than 5%, but the fixing strength will decrease.

[0083] [2. Example of Clamp Slider 1 in operation] Next, examples of the locking and unlocking operations of the clamp slider 1 will be explained using diagrams. Figure 10A is a cross-sectional view showing the unlocked state of the clamp slider 1. Figure 10B is a cross-sectional view showing the locked state of the clamp slider 1.

[0084] (2.1 Unlocked state) Figure 10A shows the unlocked state in which the clamp slider 1 and the guide rail R can slide freely relative to each other. As shown in Figure 10A, in the unlocked state, the hydraulic pressure is controlled so that the hydraulic fluid of the hydraulic unit 30 is drawn out from the space between the cover member 31 and the piston 32, and the space between the cover member 31 and the piston 32 is narrowed. Also in this unlocked state, the hydraulic pressure is controlled so that the hydraulic fluid of the hydraulic unit 35 is supplied to the space between the cover member 36 and the piston 37, and the space between the cover member 36 and the piston 37 is widened.

[0085] Due to hydraulic pressure, the piston rod 38 slides and protrudes towards the second rolling element 23 via the piston 37, pushing out the second rolling element 23. On the other hand, due to hydraulic pressure, the piston rod 33 retracts towards the cover member 31 via the piston 32.

[0086] The second rolling element 23 is pushed out in the direction of the central axis C1, becoming separated from the alignment of the three rolling elements, and the transmission of the fixing force from the spring portion 40 to the first rolling element 22 is interrupted. As a result, the fixing force from the spring portion 40 to the pressing member 21 weakens, and the ring member of the flange portion 21a causes the pressing member 21 to move towards the spring portion 40 together with the first rolling element 22, moving away from the guide rail R.

[0087] In other words, when the second rolling element 23 is removed from the state in which the first rolling element 22, the second rolling element 23, and the third rolling element 24 are in contact with each other and lined up in the direction from the spring portion 40 toward the pressing member 21, the fixing force from the spring portion 40 can no longer be sufficiently transmitted to the pressing member 21.

[0088] (2.2 Locked state) Figure 10B shows the locked state in which the guide rail R is locked by the clamp slider 1. As shown in Figure 10B, in the locked state, the hydraulic pressure is controlled so that the hydraulic fluid of the hydraulic unit 30 is supplied to the space between the cover member 31 and the piston 32, and the space between the cover member 36 and the piston 37 is expanded. Also in this locked state, the hydraulic pressure of the hydraulic unit 35 is controlled so that the hydraulic fluid is drawn out of the space between the cover member 36 and the piston 37, and the space between the cover member 36 and the piston 37 is narrowed.

[0089] By hydraulic pressure, the piston rod 33 is pushed out toward the three rolling elements 22, 23, and 24 via the piston 32, and by hydraulic pressure, the piston rod 38 is retracted toward the cover member 36 via the piston 37. The three rolling elements 22, 23, and 24 are sandwiched between the contact surface of the piston rod 33 and the inner surface 55 of the cage 50, and are aligned almost in a straight line in the direction of the central axis C2. More specifically, as shown in Figures 8 and 9, the second rolling element 23 is fixed in a state slightly offset toward the piston rod 38. The second rolling element 23 is sandwiched between the contact portion 33a of the piston rod 33 and the surface 55a of the inner surface 55 of the cage 50. The first rolling element 23 and the third rolling element 24 are sandwiched between the contact portion 33b of the piston rod 33 and the surface 55b of the inner surface 55 of the cage 50.

[0090] With the three rolling elements 22, 23, and 24 aligned almost in a straight line in the direction of the central axis C2, a fixing force from the spring portion 40 acts on the pressing member 21, causing the pressing member 21 to press against the guide rail R. The guide rail R is sandwiched and fixed between the pressing member 21 and the wall on the other side of the groove portion 11 of the housing portion 10.

[0091] In other words, with the first rolling element 22, the second rolling element 23, and the third rolling element 24 in contact with each other and aligned in a line from the spring portion 40 toward the pressing member 21, the third rolling element 24 can sufficiently transmit the fixing force from the spring portion 40 to the second rolling element 23, and the first rolling element 22 can sufficiently transmit the fixing force from the spring portion 40 toward the pressing member 21.

[0092] (2.3 Transition from unlocked state to locked state) Next, we will explain the transition from the unlocked state in Figure 10A to the locked state in Figure 10B, that is, the braking and locking.

[0093] As shown in Figures 10A and 10B, the piston rod 33 moves toward the three rolling elements 22, 23, and 24 in the direction of the central axis C1 by hydraulic control. In particular, the piston rod 33 pushes the second rolling element 23 between the first rolling element 22 and the third rolling element 24. The second rolling element 23 moves toward the central axis C1 by hydraulic pressure.

[0094] When the second rolling element 23 is pushed in, the first rolling element 22, whose cylindrical surface is in contact with the second rolling element 23, moves toward the pressing member 21, causing the pressing member 21 to move toward the guide rail R. The third rolling element 24 moves toward the spring piston 41 along with the movement of the second rolling element 23 in the direction of the central axis C1. The spring piston 41, which is in contact with the third rolling element 24, also moves toward the lock / release sensor unit 43 in the direction of the central axis C2, causing the disc spring 42 to compress and increasing the fixing force of the spring unit 40. In other words, the force pushing the third rolling element 24 back toward the second rolling element 23 increases due to the force of the disc spring 42. The lock / release sensor unit 43 follows the movement of the spring piston 41 and moves toward the outside of the housing unit 10.

[0095] As shown in Figure 10A, when the second rolling element 23 is pushed in, the cage 50 is in contact with the main body of the piston rod 38. The movement of the first rolling element 22 and the third rolling element 24 in the direction of the central axis C1 is restricted by the surface 55b of the inner surface 55 of the cage 50. As a result, the hydraulic force from the piston rod 33 moves the pressing member 21 toward the guide rail R via the first rolling element 22, which is in contact with the second rolling element 23 at its cylindrical surface, and works effectively.

[0096] The pressing member 21 contacts the guide rail R, applying a brake, and when the fixing force from the pressing member 21 exceeds a predetermined level, the mechanism locks. The second rolling element 23 is pushed in further, and when the centers of the three rolling elements 22, 23, and 24 are aligned in a straight line in the direction of the central axis C2, the fixing force of the spring section 40 is maximized.

[0097] Furthermore, the contact portion 33a of the piston rod 33 causes the second rolling element 23 to move slightly toward the piston rod 38. At this time, the first rolling element 22 and the third rolling element 24 are sandwiched between the contact portion 33b of the piston rod 33 and the inner surface 55b of the cage 50, fixing and stabilizing the three rolling elements 22, 23, and 24. The centers of the three rolling elements 22, 23, and 24 are slightly misaligned from being in a straight line in the direction of the central axis C2, but the three rolling elements 22, 23, and 24 are almost in a straight line, fully locking the guide rail R, and the locking is completed as shown in Figure 10B.

[0098] (2.4 Transition from locked state to unlocked state) Next, we will explain the transition from the unlocked state in Figure 10A to the locked state in Figure 10B, i.e., unlocking.

[0099] As shown in Figures 10B and 10A, the piston rod 38 moves toward the three rolling elements 22, 23, and 24 in the direction of the central axis C1 by hydraulic control. In particular, the piston rod 38 pushes the second rolling element 23 out from between the first rolling element 22 and the third rolling element 24.

[0100] At this time, when the hydraulic force of the piston rod 38 exceeds a predetermined value, the centers of the three rolling elements 22, 23, and 24 are aligned in a straight line in the direction of the central axis C2, exceeding the state in which the fixing force of the spring portion 40 is at its maximum. Once this state is exceeded, the first rolling element 22 and the third rolling element 24 and the second rolling element 23, whose cylindrical surface is in contact with each other, suddenly detach, the transmission of the fixing force from the spring portion 40 of the pressing member 21 is cut off, and the lock is released all at once.

[0101] The third rolling element 24 moves toward the pressing member 21 along with the movement of the second rolling element 23 in the direction of its central axis C1. The spring piston 41 that contacts the third rolling element 24 also moves toward the pressing member 21 in the direction of its central axis C2, causing the disc spring 42 to loosen and the fixing force of the spring portion 40 to decrease. The lock / release sensor portion 43 follows the movement of the spring piston 41 and moves toward the pressing member 21, that is, toward the inside of the housing portion 10.

[0102] According to the clamp slider 1 of this embodiment, a first rolling element 22, a second rolling element 23, and a third rolling element 24 are arranged sequentially between a pressing member 21 that contacts the guide rail R to fix the movement of the clamp slider 1 and a spring portion 40 that applies a fixing force to bring the pressing member 21 into contact with the guide rail R. The second rolling element 23 fits between the first rolling element 22 and the third rolling element 24, and the fixing force from the spring portion 40 is transmitted to the pressing member 21, locking the movement of the clamp slider 1. Conversely, the second rolling element 23 disengages, releasing the lock. This allows for precise switching between locked and unlocked states, and makes it easy to maintain the locked state. Furthermore, according to the clamp slider 1 of this embodiment, the transition between the locked state and the unlocked state can be performed quickly.

[0103] In conventional sliding wedge designs, the fixing force that secures the guide rail R is constant. Therefore, to increase the fixing force, it was necessary to reduce the angle of the wedge to make it closer to parallel. However, if the wedge angle is close to parallel, there is a risk that the wedge will become stuck, like a stake driven into the ground, making it impossible to release the lock.

[0104] On the other hand, in the case of rolling elements instead of sliding wedges, as in the present invention, the fixing force of the spring portion 40 is maximized when the rolling element 23 is pushed and the centers of the three rolling elements 22, 23, and 24 are aligned in a straight line in the direction of the central axis C2. Even before they become aligned, as they approach a straight line, the force pushing back against the spring portion 40 increases, allowing the spring portion 40 to generate a stronger spring force. Furthermore, since the second rolling element 23 can be easily removed from the alignment of the three rolling elements by the piston rod 38, the lock can be easily released.

[0105] Furthermore, unlike conventional technologies where a sliding wedge required a large slide when the wedge's inclination was small, the clamp slider 1 according to this embodiment does not require a large shift of the rolling element, thus allowing for a more compact design.

[0106] When the movement of the clamp slider 1 is locked by the first rolling element 22, the second rolling element 23, and the third rolling element 24 being in contact with each other and aligned in a line from the spring portion 40 toward the pressing member 21, the fixing force from the spring portion 40 acts directly on the pressing member 21 via the aligned first rolling element 22, second rolling element 23, and third rolling element 24, thus reliably locking the movement of the clamp slider 1.

[0107] When the rollers are aligned in a line, the second rolling element 23 moves in the direction along the guide rail R, acting in a direction that pushes it between the first rolling element 22 and the third rolling element 24. If the centers of the first rolling element 22, the second rolling element 23, and the third rolling element 24 are positioned beyond a straight line, the second rolling element 23 has temporarily moved beyond the straight line, creating a barrier that returns the second rolling element 23 in the opposite direction, stabilizing the locked state and making it easier to maintain the locked state.

[0108] If the system is further equipped with a piston rod 33 that acts to push the second rolling element 23 between the first rolling element 22 and the third rolling element 24 so that they are aligned in a line, and a piston rod 38 positioned opposite the piston rod 33 that moves the second rolling element 23 out of the aligned state, then the piston rods 33 and 38 acting in a direction along the guide rail R allow for precise switching between locking and unlocking, and the locked state can be easily maintained. Furthermore, this enables quick transitions between the locked and unlocked states.

[0109] The piston rod 33 has contact portions 33a and 33b that contact the first rolling element 22, the second rolling element 23, and the third rolling element 24, and the contact surface of contact portion 33a with respect to the second rolling element 23 protrudes more than the contact surface of contact portion 33b. In this case, the protruding portion can be pushed back slightly so that the second rolling element 23 is temporarily positioned beyond a straight line. This acts as a barrier to return the second rolling element 23 in the opposite direction, stabilizing the locked state and making it easier to maintain the locked state.

[0110] The device has a cage 50 that houses a first rolling element 22, a second rolling element 23, and a third rolling element 24, and the cage 50 has an opening 53 through which a piston rod 33 can pass, and the cage 50 has an internal surface 55 on the opposite side of the piston rod 33 that can contact each rolling element in a line, so that each rolling element can be sandwiched and fixed between the piston rod 33 and the internal surface 55 of the cage 50 in a line, the locked state becomes more stable and easier to maintain.

[0111] The device has a cage 50 that houses the first rolling element 22, the second rolling element 23, and the third rolling element 24, the cage 50 having an opening 53 through which the piston rod 33 can pass, and the cage 50 having an internal surface 55 on the opposite side from the piston rod 33 that can contact each rolling element in a line, and the internal surface 55 has a recessed surface 55a corresponding to the second rolling element 23, the second rolling element 23 can fix each rolling element 22, 23, and 24 in a state beyond the arrangement where the centers of each rolling element are aligned in a straight line, and the locked state becomes more stable.

[0112] When the second rolling element 23 is moved along the guide rail R by hydraulic pressure, the second rolling element 23 can be moved quietly and reliably because it is hydraulic.

[0113] When a spring mechanism is used to generate the fixing force, the mechanism for driving the fixing force can be miniaturized. In particular, the disc spring 42 allows for even greater miniaturization.

[0114] If the first rolling element 22, the second rolling element 23, and the third rolling element 24 are cylindrical, unlike a wedge, their cylindrical surfaces come into contact with each other, and the second rolling element 23 moves between the first rolling element 22 and the third rolling element 24 when locked and moves out when unlocked. This allows for a clear switching between the locked and unlocked states, and enables a quick transition between the locked and unlocked states. Furthermore, it is possible to form a barrier that returns the second rolling element 23 in the opposite direction, thereby stabilizing the locked state.

[0115] [3. Examples of application] Next, a surgical table to which the clamp slider 1 of the present invention is applied will be described using Figures 11 to 13. Figure 11 is a perspective view showing an example of the appearance of a surgical table using the clamp slider 1. Figure 12 is a perspective view showing an example of the lateral sliding part of the surgical table in Figure 11. Figure 13 is a perspective view showing an example of the lifting part of the base of the surgical table in Figure 11.

[0116] The operating table 60 to which the clamp slider 1 is applied comprises a table 61 that slides in the longitudinal direction, a lateral sliding section 62 that slides in the short direction, a lifting section 63 for adjusting the height, a base 64 that is placed on the floor in an operating room or the like, and a controller 65 that controls the hydraulic pressure for moving the table 61 and the like.

[0117] Two parallel guide rails R are fixed to the underside of table 61 with bolts or the like.

[0118] As shown in Figure 12, a clamp slider 1 is fixed to the plate member 62a of the lateral sliding section 62 using bolts or the like at the mounting member 5. Two guide rails R of the table 61 are slidable relative to the lateral sliding section 62. The clamp slider 1 acts on one of the guide rails R, and the longitudinal movement of the table 61 is locked or unlocked hydraulically by a command from the controller 65.

[0119] Furthermore, three parallel guide rails R, as shown in Figure 13, are fixed to the back side of the lateral sliding section 62 with bolts or the like.

[0120] As shown in Figure 13, one clamp slider 1 is fixed to the lifting section 63 using mounting members 5 bolts, etc., for the middle of the three guide rails R. The three guide rails R of the table 61 are slidable relative to the lifting section 63. The clamp slider 1 acts on one of the guide rails R, and according to a command from the controller 65, the movement of the lateral sliding section 62 in the short direction is locked or unlocked by hydraulics.

[0121] By using the clamp slider 1, the transition from locked to unlocked can be done quickly, allowing the locked table 61 to be quickly released and slid. Therefore, even during surgery, the locking and unlocking can be switched precisely, and the table 61 can be securely fixed in the locked state. [Explanation of Symbols]

[0122] 1: Clamp slider 10: Housing Department 20: Lock / Unlock Section 21: Pressing member (locking part) 22: First rolling element 23: Second rolling element 24: Third rolling element 30, 35: Hydraulic section 33: Piston rod (first piston rod) 38: Piston rod (second piston rod) 40: Spring section (fixing force section) 50: Cage

Claims

1. A locking device provided on a clamp slider guided by at least one guide rail, a locking portion that abuts against the guide rail to fix the movement of the clamp slider; a fixing force portion that applies a fixing force to bring the lock portion into contact with the guide rail; a first rolling element disposed between the locking portion and the fixing force portion and capable of transmitting a fixing force from the fixing force portion to the locking portion; a second rolling element that is disposed between the first rolling element and the fixing force portion, comes into contact with the first rolling element, and moves in a direction along the guide rail to lock or unlock the movement of the clamp slider; a third rolling element that is disposed between the second rolling element and the fixing force portion, that comes into contact with the second rolling element, and that is capable of transmitting a fixing force from the fixing force portion to the second rolling element; A locking device comprising:

2. 2. The locking device according to claim 1, a locking device characterized in that the movement of the clamp slider is locked by the first rolling element, the second rolling element, and the third rolling element being in contact with each other and aligned in a row from the fixing force portion to the locking portion.

3. 3. The locking device according to claim 2, The state of being lined up in a row is a locking device characterized in that the second rolling element is moved in a direction along the guide rail and forced into a position between the first rolling element and the third rolling element, so that the centers of the first rolling element, the second rolling element, and the third rolling element are positioned beyond a state in which they are aligned in a straight line.

4. 3. The locking device according to claim 2, a first piston rod that acts in a direction to push the second rolling element between the first rolling element and the third rolling element so that the second rolling element and the third rolling element are aligned in a line; a second piston rod located opposite the first piston rod and configured to move the second rolling elements out of the aligned state; A locking device further comprising:

5. The locking device according to claim 4, a locking device characterized in that the first piston rod has contact surfaces that contact the first rolling element, the second rolling element, and the third rolling element, and the contact surface that contacts the second rolling element protrudes further than the other contact surfaces.

6. 5. The locking device according to claim 4, a cage that houses the first rolling element, the second rolling element, and the third rolling element; the cage has an opening through which the first piston rod can pass; The locking device is characterized in that the cage has an inner surface that can abut against each of the rolling elements when they are aligned in a row on the side opposite to the first piston rod.

7. 6. The locking device according to claim 5, a cage that houses the first rolling element, the second rolling element, and the third rolling element; the cage has an opening through which the first piston rod can pass; the cage has an inner surface that can come into contact with each of the rolling elements in the aligned state on the side opposite to the first piston rod, A locking device characterized in that the inner surface has a recess corresponding to the second rolling element.

8. 2. The locking device according to claim 1, A locking device characterized in that the second rolling element is moved in a direction along the guide rail by hydraulic pressure.

9. 2. The locking device according to claim 1, A locking device, wherein the fixing force portion generates the fixing force by a spring mechanism.

10. 2. The locking device according to claim 1, A locking device, wherein the first rolling element, the second rolling element, and the third rolling element are cylindrical.

11. a groove portion of the housing in which the guide rail is guided; a locking portion that protrudes into the space within the groove portion and abuts against the guide rail to fix the movement of the clamp slider; a fixing force portion that applies a fixing force to bring the lock portion into contact with the guide rail; a first rolling element disposed between the locking portion and the fixing force portion and capable of transmitting a fixing force from the fixing force portion to the locking portion; a second rolling element that is disposed between the first rolling element and the fixing force portion, comes into contact with the first rolling element, and moves in a direction along the guide rail to lock or unlock the movement of the clamp slider; a third rolling element that is disposed between the second rolling element and the fixing force portion, that comes into contact with the second rolling element, and that is capable of transmitting a fixing force from the fixing force portion to the second rolling element; A clamp slider comprising:

12. A medical device comprising: a table movable relative to a base; a guide rail that defines the direction of movement of the table; and a clamp slider that is guided relative to the guide rail and locks the movement, The clamp slider is a locking portion that abuts against the guide rail to fix the movement of the clamp slider; a fixing force portion that applies a fixing force to bring the lock portion into contact with the guide rail; a first rolling element disposed between the locking portion and the fixing force portion and capable of transmitting a fixing force from the fixing force portion to the locking portion; a second rolling element that is disposed between the first rolling element and the fixing force portion, comes into contact with the first rolling element, and moves in a direction along the guide rail to lock or unlock the movement of the clamp slider; a third rolling element that is disposed between the second rolling element and the fixing force portion, that comes into contact with the second rolling element, and that is capable of transmitting a fixing force from the fixing force portion to the second rolling element; A medical device comprising: