Locking device, clamp slider, and medical device

Abstract

The present invention provides, for example, a locking device that can appropriately switch between locking and unlocking, and that can easily maintain a locked state. Provided is a locking device which is provided to a clamp slider 1 that is guided using at least one guide rail R, said locking device comprising: a lock part (21) that contacts the guide rail and fixes movement of the clamp slider; a fixing force part (40) that applies a fixing force for causing the lock part to contact the guide rail; a first rolling element 22 that is disposed between the lock part and the fixing force part and that is capable of transmitting the fixing force from the fixing force part to the lock part; a second rolling element 23 that is disposed between the first rolling element and the fixing force part, that contacts the first rolling element, and that moves in a direction along the guide rail so as to lock or unlock movement of the clamp slider; and a third rolling element 24 that is disposed between the second rolling element and the fixing force part, that contacts the second rolling element, and that is capable of transmitting the fixing force from the fixing force part to the second rolling element.

Description

Locking device, clamp slider and medical device

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

[0002] For medical devices such as operating tables used in operating rooms or treatment rooms, locking devices have been developed that lock and unlock the sliding of a table on which a patient is placed depending on the situation of the medical procedure. For example, Patent Document 1 discloses a braking and clamping device provided on a carriage guided by a guide rail, the braking and clamping device having at least one friction locking device operable via a sliding wedge transmission, the friction locking device having at least one pressing member supported in a housing and capable of pressing against the guide rail, the sliding wedge transmission being moved in one direction using at least a spring force to load the friction locking device and being moved in the opposite direction using pneumatic or hydraulic pressure by at least one piston to release the load, the sliding wedge of the sliding wedge transmission acting on the pressing member via at least one rolling element, the rolling element being supported in a cage.

[0003] Special Publication No. 2012-517571

[0004] However, because the inclination of the sliding wedge presses the pressing member against the guide rail, if the inclination of the wedge is small, the wedge may get stuck in the locked state and be unable to be released, while if the inclination of the wedge is large, the reaction force is large even in the locked state, so it is necessary to constantly press the wedge hard in the sliding direction.As a result, it is difficult to simultaneously switch between locked and unlocked states and easily maintain the locked state.

[0005] Therefore, the present invention has been made in consideration of the above problems, and one example of the object is to provide a locking device or the like that can accurately switch between lock and unlock and easily maintain the locked state.

[0006] In order to solve the above problem, the invention described in claim 1 is a locking device provided on a clamp slider that is guided using at least one guide rail, and is characterized by comprising: a locking section that abuts against the guide rail to fix the movement of the clamp slider; a fixing force section that applies a fixing force to abut the locking section against the guide rail; a first rolling element 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 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 that is arranged between the second rolling element and the fixing force section and abuts against the second rolling element and is capable of transmitting the fixing force from the fixing force section to the second rolling element.

[0007] The invention described in claim 2 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 abut against each other and are aligned in a row in the direction from the fixing force portion to the locking portion, thereby locking the movement of the clamp slider.

[0008] The invention of claim 3 is characterized in that, in the locking device of claim 2, the state of being lined up in a row is a state in which the second rolling element is moved in a direction along the guide rail and forced into between the first rolling element and the third rolling element, exceeding the state in which the centers of the first rolling element, the second rolling element, and the third rolling element are 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, it further comprises 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 they are aligned in a row, and a second piston rod that is located opposite the first piston rod and moves the second rolling element out of the aligned state.

[0010] 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 the second rolling element protrudes more than the other contact surfaces.

[0011] The invention of claim 6 is characterized in that, in the locking device of claim 4, there is provided a cage that houses 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 that can abut against each of the rolling elements when lined up in a row on the side opposite the first piston rod.

[0012] The invention of claim 7 is the locking device of claim 5, further comprising a cage that houses 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, the cage having an inner surface on the opposite side to the first piston rod that can come into contact with each of the rolling elements when lined up in a row, and the inner surface having a recess corresponding to the second rolling element.

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

[0014] According to a ninth aspect of the present invention, in the locking device of the first aspect, the fixing force portion generates the fixing force by a spring mechanism.

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

[0016] The invention described in claim 11 is characterized in that it comprises: a groove portion of a housing along which a 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 make the locking portion abut against the guide rail; a first rolling element that is arranged between the locking portion and the fixing force portion and is capable of transmitting the fixing force from the fixing force portion to the locking portion; a second rolling element that is arranged between the first rolling element and the fixing force portion 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 that is arranged between the second rolling element and the fixing force portion and abuts against the second rolling element to transmit the fixing force from the fixing force portion to the second rolling element.

[0017] The invention described in claim 12 is a medical device comprising a table movable relative to a base, a guide rail that determines the direction of movement of the table, and a clamp slider that is guided along the guide rail to lock its movement, wherein the clamp slider has a locking section that abuts against the guide rail to fix the movement of the clamp slider, a fixing force section that applies a fixing force to abut the locking section against the guide rail, a first rolling element 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 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 that is arranged between the second rolling element and the fixing force section and abuts against the second rolling element and is capable of transmitting the fixing force from the fixing force section to the second rolling element.

[0018] According to the present invention, in the first rolling body, second rolling body, and third rolling body arranged in sequence between the locking section that abuts against the guide rail to fix the movement of the clamp slider and the fixing force section that applies a fixing force to abut the locking section against the guide rail, the second rolling body enters between the first rolling body and the third rolling body, and the fixing force from the fixing force section is transmitted to the locking section to lock the movement of the clamp slider, and conversely, the second rolling body comes out and the lock is released, so that switching between lock and unlock can be performed accurately and the locked state can be easily maintained.

[0019] 1. A perspective view showing an example of the internal configuration of a clamp slider according to the present embodiment. 2. A perspective view showing an example of the external configuration of the clamp slider of FIG. 1. 3. A perspective view showing an example of the external configuration of the clamp slider of FIG. 1. 4. A cross-sectional view showing an example of a cross section of the clamp slider of FIG. 3. 5. A perspective cross-sectional view showing an example of a cross section of the clamp slider of FIG. 3. 6. A perspective view showing an example of a first piston rod of FIG. 1. 7. A perspective view showing an example of a cage of FIG. 1. 8. A perspective view showing an example of a cage of FIG. 1. 9. A perspective view showing an example of an arrangement of the cage of FIG. 1 and each member. 10. A cross-sectional view showing an example of an arrangement of the cage of FIG. 1 and each member. 11. A cross-sectional view showing an example of an operation of the clamp slider. 12. A cross-sectional view showing an example of an operation of the clamp slider. 13. A perspective view showing an example of the appearance of a surgical table using the clamp slider of FIG. 1. 14. A perspective view showing an example of a lateral slide unit of the surgical table of FIG. 11. 15. A perspective view showing an example of a lifting unit in the base of the surgical table of FIG. 11.

[0020] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that the embodiment described below is an embodiment in which the present invention is applied to a clamp slider or the like.

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

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

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

[0024] As shown in Figure 1, the clamp slider 1 of this embodiment comprises a housing portion 10 that is slidably installed relative to the guide rail R, a locking / unlocking portion 20 that locks and unlocks the movement of the clamp slider 1 relative to the guide rail R, hydraulic portions 30, 35 that lock and unlock the locking / unlocking portion 20 using hydraulic pressure, a spring portion 40 that applies a fixing force to abut against the guide rail, and a cage 50 that houses some of the components that make up the locking / unlocking portion 20.

[0025] The locking device of the locking mechanism provided on the clamp slider guided by the guide rail is composed of at least the locking / unlocking unit 20 and the spring unit 40. The locking device may also have hydraulic units 30, 35 and a cage 50.

[0026] The clamp slider 1 is fixed with a bolt or the like to an object that slides relative to the guide rail R, and fixes or releases the sliding movement of the object. For example, when the clamp slider 1 is installed on an operating table, it fixes or releases the sliding movement of the table of the operating table. The locking device of the present application can be applied to objects that slide along guide rails, such as conveyance devices for liquid crystals, semiconductors, etc., and machine tools.

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

[0028] The groove portion 11 is formed in a direction D1 along the guide rail R, with a size large enough to accommodate the guide rail R.

[0029] The through hole 12 is cylindrical with a central axis C1 in a direction D1 along the guide rail R, and is formed to a size that can accommodate a piston or the like of the hydraulic unit 30. The through hole 12 has an opening that opens to the outside of the housing unit 10, and is connected to the accommodation space 14 via a connection hole 14a.

[0030] The through hole 13 is cylindrical with a central axis C1 in a direction D1 along the guide rail R, and is formed to a size that can accommodate a piston or the like of the hydraulic unit 35. The through hole 13 has an opening that opens to the outside of the housing unit 10, and is in communication with the accommodation space 14 via a connection hole 14b.

[0031] The accommodation space 14 is formed to a size that can accommodate the cage 50 and the like.

[0032] The through hole 15 is cylindrical and has a central axis C2 perpendicular to the central axis C1, and is formed to a size that can accommodate the pressing member 21. The through hole 15 has an opening that opens into the groove 11 of the housing part 10, and communicates with the accommodation space 14.

[0033] The through hole 16 is cylindrical with a central axis C2 and is formed in a size that can accommodate the disc springs, spring pistons, etc. of the spring portion 40. The through hole 16 has an opening that opens to the outside of the housing portion 10 and communicates with the accommodation space 14. The outer opening of the through hole 16 is fitted with a spring accommodation portion 42a that can accommodate stacked disc springs 42 using a screw structure.

[0034] As shown in Figure 2, the housing 10 has a mounting member 5 that is attached with bolts or the like to an object that slides along the guide rail R. A recess is formed in the surface of the housing 10 on the side opposite the groove 11, and the mounting member 5 is embedded in the recess. The mounting member 5 is fixed to the housing 10 at its center with bolts or the like. The mounting member 5 has four bolt holes formed in it for attaching it to an object.

[0035] The clamp slider 1 and the guide rail R move relative to each other. For example, the attachment target attached by the attachment member 5 of the clamp slider 1 may move while being guided on a guide rail R installed on a base or the like, or the clamp slider 1 attached to the attachment target installed on a base or the like may slide while being guided by at least one guide rail R installed on a table.

[0036] 1, 4, and 5, the lock / unlock unit 20 has a pressing member 21 that abuts against the guide rail R, a first rolling element 22 that can transmit a fixing force from a spring portion 40 to the pressing member 21, a second rolling element 23 that abuts against 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 abuts against the second rolling element 23 and can transmit the fixing force from the spring portion 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 unit that transmits the fixing force from the spring portion 40, which is a fixing force unit, to the pressing member 21, which is an example of a lock unit.

[0037] The pressing member 21 is an example of a locking portion that comes into contact with 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 portion of the pressing member 21 that comes into contact with the guide rail R functions as a brake shoe.

[0038] The pressing member 21 is substantially cylindrical and has a flange 21a. The diameter of the flange 21a is larger than the diameter of the through-hole 15 and is located on the housing space 14 side, preventing the pressing member 21 from slipping out of the through-hole 15 into the groove 11. A resilient ring member is inserted into the portion of the flange 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 of the housing space 14 on the through-hole 15 side. 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 pressing member 21 and the first rolling element 22 remain in contact. This prevents rattle. The ring member is preferably made of a resilient material such as urethane or rubber. The ring member may also be made of a resilient material such as a metal disc spring. The ring member may be omitted.

[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 axis C1 and the central axis C2. The first rolling element 22 is disposed between the pressing member 21 and the spring portion 40. The first rolling element 22 is disposed between the pressing member 21 and the second rolling element 23 so that they are 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 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 disposed between the locking portion and the fixing force portion and is capable of transmitting the fixing force from the fixing force portion to the locking portion.

[0041] The second rolling element 23 is cylindrical in 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 disposed between the first rolling element 22 and the spring portion 40. The second rolling element 23 is disposed 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 contact with the first rolling element 22 and the third rolling element 24. The second rolling element 23 abuts against 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 body 23 is an example of a second rolling body that is arranged between the first rolling body and the fixing force portion, and that abuts against the first rolling body and moves in a direction along the guide rail to lock or unlock the movement of the clamp slider.

[0043] The third rolling element 24 is cylindrical. The central axis of the cylindrical third rolling element 24 is perpendicular to the central axis C1 and the central axis C2. The third rolling element 24 is disposed between the second rolling element 23 and the spring portion 40 so as to be in contact with each other. 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 contact with the bottom surfaces of the second rolling element 23 and the second spring piston 41. The third rolling element 24 abuts against 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 body 24 is an example of a third rolling body that is arranged between the second rolling body and the fixing force section, abuts against the second rolling body, and is capable of transmitting the fixing force from the fixing force section to the second rolling body.

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

[0046] The first rolling element 22, the second rolling element 23, and the third rolling element 24 are preferably made of a material that is less susceptible to wear, such as alloy steel, carbon steel, stainless steel, ceramic, etc. The first rolling element 22, the second rolling element 23, and the third rolling element 24 are preferably cylindrical in shape, but may also be spherical.

[0047] The hydraulic section 30 has a cover member 31 having a packing mechanism to prevent hydraulic oil from leaking, a piston 32 that slides in the direction of the central axis C1 by the hydraulic oil, 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 close one end of the through-hole 12. The cover member 31 has a supply port through which hydraulic oil is supplied. 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, into which one end of the piston rod 33 fits.

[0050] The piston 32 is made of steel, stainless steel, aluminum, or a copper alloy.

[0051] A ring member made of elastomer such as rubber is installed on the piston 32 to prevent hydraulic oil from leaking. The piston 32 slides within the through-hole 12. A tubular member for improving surface roughness and precision is inserted between the inner wall of the through-hole 12 and the piston 32 to facilitate sliding of the piston 32 and prevent hydraulic oil from leaking. Examples of materials for the tubular member include steel, carbon steel, alloy steel, stainless steel, and copper alloy.

[0052] As shown in FIG. 6 , the piston rod 33 has an abutment portion 33a that abuts against the second rolling element 23, an abutment portion 33b that abuts against the first rolling element 22 and the third rolling element 24, a fitting portion 33c that fits into a fitting hole in the piston rod 33, and four recesses 33d that are milled from the abutment portion 33b side toward the center axis C3. The abutment portion 33a protrudes slightly from the abutment 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% of the diameter of the second rolling element 23. 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, and is preferably the same as 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 be reduced.

[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 rolling element and the third rolling element so that they are aligned in a row. The piston rod 33 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.

[0054] 4 and 5, the piston rod 33 is installed through the through-hole 12 into the connecting hole 14a so that the central axis C3 of the piston rod 33 coincides with the central axis C1. The abutting portions 33a and 33b are present in the accommodation space 14. The piston rod 33 slides within the connecting hole 14a.

[0055] Examples of materials for the piston rod 33 include steel, carbon steel, alloy steel, stainless steel, and copper alloy.

[0056] The hydraulic section 35 has a cover member 36 having a packing mechanism to prevent hydraulic oil from leaking, a piston 37 that slides in the direction of the central axis C1 by the hydraulic oil, 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 close one end of the through-hole 13. The cover member 36 has a supply port through which hydraulic oil is supplied. The hydraulic unit 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 thereof, into which one end of the piston rod 38 fits. The material of the piston 37 is the same as that of the piston 32. The piston 37 slides within the through hole 13. As in the case of the through hole 12, a tubular member is inserted between the inner wall of the through hole 13 and the piston 37 to facilitate sliding of the piston 32 and prevent leakage of hydraulic oil.

[0059] The piston rod 38 has an abutment 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 so that it abuts only against the second rolling element 23, and the abutment portion of the piston rod 38 has a thin rectangular pillar shape. One end of the cylindrical main body portion of the piston rod 38 directly serves as the fitting portion.

[0060] The piston rod 38 is an example of a second piston rod that is located opposite the first piston rod and moves the second rolling elements out of alignment.

[0061] 4 and 5 , the piston rod 38 is installed through the through-hole 13 into the connecting hole 14b so that the axis of the piston rod 38 coincides with the central axis C1. The abutting portion of the piston rod 38 is present in the accommodation space 14. The main 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 move the piston rod 33 and the piston rod 38 in an interlocking manner in opposite directions. 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 in the direction along the guide rail R by hydraulic pressure.

[0063] The spring portion 40 has 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 on the spring piston 41 in a direction toward the pressing member 21, and a lock / unlock sensor portion 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 a hole in the stacked disc springs 42. The shape of the spring piston 41 is a stack of cylinders with different diameters, and the diameter of the contact portion 41a is larger than that of the spring shaft portion 41b. The spring piston 41 is made of the same material as 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 the spring piston 41 are housed in a spring housing portion 42a. The disc spring 42 mainly generates a fixing force that causes the spring 42 to abut against the guide rail R. A coil spring may be used instead of the disc spring 42.

[0066] In this way, the spring portion 40 is an example of a fixing force portion that applies a fixing force to cause the pressing member 21, which is an example of a locking portion, to abut against the guide rail R. The spring portion 40 is an example of a fixing force portion that generates a fixing force by a spring mechanism.

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

[0068] (1.2 Overview of the Structure and Function of the Cage 50) Next, an overview of the structure and function of the cage 50 will be described with reference to the drawings. Figures 7A and 7B are perspective views showing an example of the cage of Figure 1.

[0069] 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 in an end face 50a of one bottom surface of the cylindrical cage 50, and the opening 52 is formed in an end face 50b of the other bottom surface of the cylindrical body. The openings 53 and 54 are formed in the cylindrical surfaces of the cylindrical cage 50.

[0070] The cage 50 is a cylindrical metal member having openings 51, 52, 53, 54 and an internal space formed therein 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 rods. Examples of materials for the cage 50 include alloy steel, carbon steel, and stainless steel.

[0071] The shape of the opening 51 is a rectangle, which is the cross section of the first rolling element 22 in the longitudinal direction. The shape of the opening 52 is a rectangle, which is the cross section of the third rolling element 24 in the longitudinal direction. The shape of the opening 53 is a shape that allows the contact portions 33a and 33b of the piston rod 33 to slide. The shape of the opening 54 is a shape that allows the contact portion of the piston rod 38 to slide.

[0072] The cage 50 accommodates and covers 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 accommodates these rolling elements so as to maintain 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 the locked state and the unlocked state. The cage 50 also acts to ensure smooth changes in arrangement during transition between the locked state and the unlocked state. The cage 50 is installed in the accommodation space 14 so that the central axis C4 of the cage 50 is parallel to the central axis C1. The cage 50 is accommodated in the accommodation space 14 so as to be displaceable in the direction of the central axis C1.

[0073] Thus, the cage 50 is an example of a cage that houses the first rolling element, the second rolling element, and the third rolling element. The 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 against which the second rolling element 23 can abut and a surface 55b against which the first rolling element 22 and the third rolling element 24 can slide in the direction of the central axis C4. The surface 55a is formed slightly closer to the opening 54 than the surface 55b, forming a recess in 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 abutment 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 this corresponds to the contact portion 33a of the piston rod 33, it is preferable that the protrusion of the contact portion 33a be equal to the protrusion of the contact portion 33b of the piston rod 33. Note that this slight recess may be greater than 5%, but the fixing force will decrease.

[0075] In this way, the inner surface 55 is an example of an inner surface that can come into contact with each rolling element while being aligned in a row on the side opposite to 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 Member) Next, the arrangement of the cage 50 and each member of the hydraulic units 30, 35 and the locking / unlocking unit 20 will be described with reference to Figures 8 and 9. Figure 8 is a perspective view showing an example of the arrangement of the cage 50 and each member. 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 each member.

[0077] 8 and 9 are views showing the locked state. As shown in Figures 8 and 9, the piston rod 33, the rolling elements 22, 23, and 24, and the piston rod 38 are arranged in a direction D1 along the guide rail R. The rolling elements 22, 23, and 24 and portions of the piston rod 33 and the piston rod 38 are housed in a 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 a substantially straight line perpendicular to the direction D1.

[0078] In the locked state, the protruding contact portion 33a of the piston rod 33 causes the second rolling element 23 to be 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 receives 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 able to slide relative to each other in the direction D1 through an opening 53 in the cage 50. The piston rod 38 and the cage 50 are able to slide relative to each other in the direction D1 through an opening 52 in the cage 50.

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

[0081] With the first rolling element 22, the second rolling element 23, and the third rolling element 24 aligned in a substantially straight line, a locked state is reached in which the fixing force from the spring piston 41 is directly applied to the guide rail R. That is, the first rolling element 22, the second rolling element 23, and the third rolling element 24 abut against each other and are aligned in a line in the direction from the spring portion 40 to 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 abutment portions 33a and 33b of the piston rod 33 and the surfaces 55a and 55b of the inner surface 55 of the cage 50, so that the locked state is stable even when subjected to external forces such as vibration. That is, the abutment portion 33a of the piston rod 33 moves the second rolling element 23 in a direction along the guide rail R, acting in a direction to compress it between the first rolling element 22 and the third rolling element 24, resulting in a state in which the centers of the first rolling element 22, the second rolling element 23, and the third rolling element 24 are no longer aligned in a straight line. This slight offset is preferably 1% to 5% of the diameter of the second rolling element 23. This slight deviation may be greater than 5%, but the fixing force will decrease.

[0083] 2. Operational Example of Clamp Slider 1 Next, an operational example of locking and unlocking the clamp slider 1 will be described with reference to the drawings. Fig. 10A is a cross-sectional view showing the unlocked state of the clamp slider 1. Fig. 10B is a cross-sectional view showing the locked state of the clamp slider 1.

[0084] (2.1 Unlocked State) Figure 10A shows an 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 oil of the hydraulic unit 30 is taken out of the space between the cover member 31 and the piston 32, narrowing the space between the cover member 31 and the piston 32. Also, in this unlocked state, the hydraulic pressure is controlled so that the hydraulic oil of the hydraulic unit 35 is supplied to the space between the cover member 36 and the piston 37, widening the space between the cover member 36 and the piston 37.

[0085] The hydraulic pressure causes the piston rod 38 to slide and protrude toward the second rolling element 23 via the piston 37, pushing out the second rolling element 23. On the other hand, the hydraulic pressure causes the piston rod 33 to retract toward 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 and is out of the arrangement of the three rolling elements, and the transmission of the fixing force from the spring portion 40 to the first rolling element 22 is cut off. As a result, the fixing force from the spring portion 40 to the pressing member 21 is weakened, and the ring member of the flange portion 21 a moves the pressing member 21 together with the first rolling element 22 toward the spring portion 40, and they are separated from the guide rail R.

[0087] In other words, when the first rolling body 22, the second rolling body 23 and the third rolling body 24 are in contact with each other and lined up in a row from the spring portion 40 toward the pressing member 21, if the second rolling body 23 is removed, 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 a 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 hydraulic oil from the hydraulic unit 30 is supplied to the space between the cover member 31 and the piston 32, widening the space between the cover member 36 and the piston 37. Also, in this locked state, the hydraulic pressure is controlled so that hydraulic oil from the hydraulic unit 35 is removed from the space between the cover member 36 and the piston 37, narrowing the space between the cover member 36 and the piston 37.

[0089] The piston rod 33 is hydraulically pushed toward the three rolling elements 22, 23, and 24 via the piston 32, while the piston rod 38 is hydraulically retracted toward the cover member 36 via the piston 37. The three rolling elements 22, 23, and 24 are sandwiched between the abutment surface of the piston rod 33 and the inner surface 55 of the cage 50, and are aligned substantially in a straight line along the central axis C2. More specifically, as shown in FIGS. 8 and 9 , the second rolling element 23 is fixed slightly offset toward the piston rod 38. The second rolling element 23 is sandwiched between the abutment 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 abutment 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 substantially in a straight line in the direction of the central axis C2, the 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, when the first rolling body 22, the second rolling body 23 and the third rolling body 24 are in contact with each other and lined up in a row in the direction from the spring portion 40 to the pressing member 21, the third rolling body 24 can fully transmit the fixing force from the spring portion 40 to the second rolling body 23, and the first rolling body 22 can fully transmit the fixing force from the spring portion 40 to the pressing member 21.

[0092] (2.3 Transition from Unlocked State to Locked State) Next, the transition from the unlocked state of FIG. 10A to the locked state of FIG. 10B, that is, braking and fixing, will be described.

[0093] 10A and 10B, the piston rod 33 is moved by hydraulic pressure control toward the three rolling elements 22, 23, and 24 in the direction of the central axis C1. 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 is moved by hydraulic pressure in the direction of the central axis C1.

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

[0095] 10A , when the second rolling element 23 is pressed in, the cage 50 abuts against 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. Therefore, 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 is able to function sufficiently.

[0096] The pressing member 21 contacts the guide rail R to apply the brake, and when the fixing force from the pressing member 21 reaches a predetermined value or more, the locking state is activated. When the second rolling element 23 is further pressed in and the centers of the three rolling elements 22, 23, and 24 are aligned in a straight line along the central axis C2, the fixing force of the spring portion 40 becomes maximum.

[0097] Furthermore, the second rolling element 23 moves slightly toward the piston rod 38 due to the abutment portion 33a of the piston rod 33. At this time, the first rolling element 22 and the third rolling element 24 are sandwiched between the abutment portion 33b of the piston rod 33 and the surface 55b of the inner surface 55 of the cage 50, and the three rolling elements 22, 23, and 24 are fixed and stabilized. Although the centers of the three rolling elements 22, 23, and 24 are slightly deviated from a state in which they are aligned in a straight line in the direction of the central axis C2, the three rolling elements 22, 23, and 24 remain substantially aligned, sufficiently locking the guide rail R and completing the locking as shown in FIG. 10B .

[0098] (2.4 Transition from Locked State to Unlocked State) Next, the transition from the unlocked state in FIG. 10A to the locked state in FIG. 10B, that is, unlocking, will be described.

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

[0100] At this time, when the hydraulic pressure of the piston rod 38 exceeds a predetermined value, the centers of the three rolling elements 22, 23, 24 are aligned in a straight line in the direction of the central axis C2, and the state where the fixing force of the spring portion 40 is at its maximum is overcome. Once this state is overcome, the first rolling element 22 and the third rolling element 24 suddenly separate from the second rolling element 23, whose cylindrical surfaces are in contact with each other, and 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 the central axis C1. The spring piston 41 in contact with the third rolling element 24 also moves toward the pressing member 21 in the direction of the central axis C2, the disc spring 42 loosens, and the fixing force of the spring portion 40 also decreases. The lock / unlock sensor portion 43 moves toward the pressing member 21, i.e., toward the inside of the housing portion 10, following the movement of the spring piston 41.

[0102] According to the clamp slider 1 of the embodiment, the first rolling element 22, the second rolling element 23, and the third rolling element 24 are arranged in this order between the pressing member 21 that abuts against the guide rail R to fix the movement of the clamp slider 1, and the spring portion 40 that applies a fixing force to bring the pressing member 21 into contact with the guide rail R, so that the second rolling element 23 enters 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 to lock the movement of the clamp slider 1, and conversely, the second rolling element 23 comes out to release the lock, so that switching between the locked and unlocked states can be performed accurately and the locked state can be easily maintained. Furthermore, the clamp slider 1 of the embodiment can quickly transition between the locked state and the unlocked state.

[0103] In the case of a sliding wedge, as in the prior art, the fixing force that fixes the guide rail R is constant. Therefore, in order to increase the fixing force, it was necessary to reduce the angle of the wedge and make it closer to parallel. However, if the angle of the wedge is closer to parallel, there is a risk that the wedge will get stuck like a stake being driven into the rail, making it impossible to release the lock.

[0104] On the other hand, in the case of rolling elements rather than sliding wedges as in the present application, 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 along the central axis C2. As the rolling elements approach a straight line, even before they are aligned, the force pushing back against the spring portion 40 becomes stronger, allowing the spring portion 40 to generate a stronger spring force. Furthermore, the second rolling element 23 can be easily removed from the alignment of the three rolling elements by the piston rod 38, making it easy to unlock.

[0105] Furthermore, in the case of a sliding wedge with a small inclination, as in the prior art, the wedge had to be slid a large distance, but the clamp slider 1 according to the embodiment does not require the rolling element to be shifted a large distance, and therefore can be made smaller.

[0106] When the movement of the clamp slider 1 is locked by the first rolling body 22, the second rolling body 23 and the third rolling body 24 abutting against each other and lining up in a row from the spring portion 40 towards the pressing member 21, the fixing force from the spring portion 40 acts directly on the pressing member 21 via the first rolling body 22, the second rolling body 23 and the third rolling body 24 which are lined up in a row, so that the movement of the clamp slider 1 is reliably locked.

[0107] The state of being lined up in a row causes the second rolling body 23 to move in a direction along the guide rail R, acting in a direction that pushes it between the first rolling body 22 and the third rolling body 24, and when the centers of the first rolling body 22, the second rolling body 23 and the third rolling body 24 go beyond the state in which they are lined up in a straight line, the second rolling body 23 has once gone beyond the state in which they are lined up in a straight line, and therefore acts as a barrier that causes the second rolling body 23 to return in the opposite direction, stabilizing the locked state and making it easier to maintain the locked state.

[0108] When the device further includes a piston rod 33 that acts in a direction 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 row, and a piston rod 38 that is located opposite the piston rod 33 and moves the second rolling element 23 out of the aligned state, the piston rod 33 and the piston rod 38 that act in a direction along the guide rail R can accurately switch between the locked and unlocked states and easily maintain the locked state. This also enables a quick transition between the locked state and the unlocked state.

[0109] When the piston rod 33 has contact portions 33a and 33b that contact the first rolling body 22, the second rolling body 23 and the third rolling body 24, and the contact surface of the contact portion 33a with the second rolling body 23 protrudes more than the contact surface of the contact portion 33b, the second rolling body 23 can be pushed in slightly by the protruding amount so that it moves beyond the linear arrangement, which acts as a barrier to move the second rolling body 23 back in the opposite direction, stabilizing the locked state and making it easier to maintain the locked state.

[0110] When a cage 50 is provided that houses the first rolling element 22, the second rolling element 23, and the third rolling element 24, and the cage 50 has an opening 53 through which the piston rod 33 can pass, and the cage 50 has an inner surface 55 that can abut each of the rolling elements when lined up in a row on the opposite side of the piston rod 33, the piston rod 33 and the inner surface 55 of the cage 50 can sandwich and fix each of the rolling elements when lined up in a row, making the locked state more stable and making it easier to maintain the locked state.

[0111] The cage 50 houses the first rolling element 22, the second rolling element 23, and the third rolling element 24, and the cage 50 has an opening 53 through which the piston rod 33 can pass. The cage 50 has an inner surface 55 that can abut each of the rolling elements when they are lined up in a row on the opposite side of the piston rod 33. If the inner surface 55 has a recessed surface 55a corresponding to the second rolling element 23, the second rolling element 23 can fix each of the rolling elements 22, 23, 24 in a state where the centers of each rolling element are not aligned in a straight line, and the locked state becomes more stable.

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

[0113] When the fixing force is generated by a spring mechanism, the fixing force drive mechanism can be made smaller. In particular, the disc spring 42 can make it even more compact.

[0114] When the first rolling element 22, the second rolling element 23, and the third rolling element 24 are cylindrical, unlike wedges, 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, so that the locked and unlocked states switch clearly and the transition between the locked and unlocked states can be made quickly.In addition, it is possible to form a barrier that forces the second rolling element 23 to return in the opposite direction, making it possible to stabilize the locked state.

[0115] 11 to 13, a surgical table to which the clamp slider 1 of the present application is applied will be described. Fig. 11 is a perspective view showing an example of the appearance of a surgical table using the clamp slider 1. Fig. 12 is a perspective view showing an example of a lateral slide unit of the surgical table in Fig. 11. Fig. 13 is a perspective view showing an example of an elevation unit in the base of the surgical table in Fig. 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 slide section 62 that slides in the lateral direction, a lifting section 63 for adjusting the height, a base 64 that is placed on the floor of an operating room or the like, and a controller 65 that controls the hydraulic pressure for moving the table 61, etc.

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

[0118] 12, one clamp slider 1 is fixed to a plate member 62a of the lateral slide portion 62 with a bolt or the like on a mounting member 5. Two guide rails R of the table 61 are slidable relative to the lateral slide portion 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 by hydraulic pressure in response to a command from a controller 65.

[0119] Three parallel guide rails R shown in FIG. 13 are fixed to the rear side of the horizontal slide portion 62 with bolts or the like.

[0120] 13, one clamp slider 1 is fixed to the lifting section 63 with a mounting member 5 bolt or the like for the middle guide rail R of 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 the movement of the lateral slide section 62 in the short side direction is locked or unlocked by hydraulic pressure in response to a command from the controller 65.

[0121] By using the clamp slider 1, the transition from the locked state to the unlocked state can be made quickly, so that the locked table 61 can be quickly unlocked and slid. Therefore, even during surgery, the switching between lock and unlock can be performed accurately, and the table 61 can be fixed accurately in the locked state.

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

Claims

1. A locking device provided on a clamp slider that is guided using at least one guide rail, comprising: a locking section that comes into contact with the guide rail to fix the movement of the clamp slider; a fixing force section that applies a fixing force to bring the locking section into contact with the guide rail; a first rolling element that is arranged between the locking section and the fixing force section and is capable of transmitting a fixing force from the fixing force section to the locking section; a second rolling element that is arranged between the first rolling element and the fixing force section and 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; and a third rolling element that is arranged between the second rolling element and the fixing force section and comes into contact with the second rolling element and is capable of transmitting a fixing force from the fixing force section to the second rolling element.

2. A locking device as claimed in claim 1, characterized in that the movement of the clamp slider is locked when the first rolling body, the second rolling body and the third rolling body come into contact with each other and are aligned in a row in the direction from the fixing force section to the lock section.

3. A locking device as described in claim 2, characterized in that the state of being aligned in a line is a state in which the second rolling body is moved in a direction along the guide rail and forced into between the first rolling body and the third rolling body, going beyond an arrangement in which the centers of the first rolling body, the second rolling body and the third rolling body are aligned in a straight line.

4. A locking device as described in claim 2, further comprising: 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 they are aligned in a row; and a second piston rod that is positioned opposite the first piston rod and moves the second rolling element out of the aligned state.

5. A locking device as described in claim 4, characterized in that the first piston rod has contact surfaces which contact the first rolling body, the second rolling body and the third rolling body, and the contact surface with the second rolling body protrudes further than the other contact surfaces.

6. A locking device as described in claim 4, further comprising a cage that houses the first rolling body, the second rolling body and the third rolling body, the cage having an opening through which the first piston rod can pass, and the cage having an inner surface that can abut against each of the rolling bodies when aligned in a row on the side opposite the first piston rod.

7. A locking device as described in claim 5, further comprising a cage that houses the first rolling body, the second rolling body and the third rolling body, the cage having an opening through which the first piston rod can pass, the cage having an inner surface on the opposite side to the first piston rod that can abut against each of the rolling bodies when lined up in a row, and the inner surface having a recess corresponding to the second rolling body.

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

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

10. A locking device according to claim 1, wherein the first rolling body, the second rolling body and the third rolling body are cylindrical bodies.

11. A clamp slider comprising: a groove portion of a housing along which a guide rail is guided; a locking portion that protrudes into the space within the groove portion and comes into contact with the guide rail to fix the movement of the clamp slider; a fixing force portion that applies a fixing force to bring the locking portion into contact with the guide rail; a first rolling element that is arranged between the locking portion and the fixing force portion and is capable of transmitting a fixing force from the fixing force portion to the locking portion; a second rolling element that is arranged between the first rolling element and the fixing force portion and 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; and a third rolling element that is arranged between the second rolling element and the fixing force portion and comes into contact with the second rolling element to transmit a fixing force from the fixing force portion to the second rolling element.

12. A medical device comprising a table movable relative to a base, a guide rail which determines the direction of movement of the table, and a clamp slider which is guided relative to the guide rail to lock its movement, wherein the clamp slider has: a locking section which comes into contact with the guide rail to fix the movement of the clamp slider; a fixing force section which applies a fixing force to bring the locking section into contact with the guide rail; a first rolling body which is arranged between the locking section and the fixing force section and is capable of transmitting a fixing force from the fixing force section to the locking section; a second rolling body which is arranged between the first rolling body and the fixing force section and comes into contact with the first rolling body and moves in a direction along the guide rail to lock or unlock the movement of the clamp slider; and a third rolling body which is arranged between the second rolling body and the fixing force section and comes into contact with the second rolling body to transmit a fixing force from the fixing force section to the second rolling body.

Images