JP5058670B2 - Caster lock mechanism of caster frame - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve reliable performance and improvement in operability of each lock mechanism in a bed with casters with the lock mechanisms. <P>SOLUTION: The casters 4 with the lock mechanisms are arranged at four corners of a bed frame, and the rotary cams of the left and right lock mechanisms are combined by a rotary shaft 9 and rotated coaxially, and moreover, the front and rear lock mechanisms, which is one of the left and the right, are link-coupled via a ratchet gear device and an interlocking lever 18. Operation arms 12 are pivotally supported in the front side of the frame so as to be rotated coaxially with the rotary shaft, ratchet gears 15 are fixed in the rotary shaft, and claws 16 energized by a spring toward ratchets are pivotally supported in the operation arms. The rotary cams can be stepped by rotation of the operation arms by a prescribed angle from an initial position, and the operation arms are energized by the spring and returned to the initial position. Thus, the lock and release of the lock mechanisms can be repeated at each operation, and the operation can be simplified without inconvenience. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a caster lock mechanism for a bed such as a movable bed, a cart, or a carriage.

Conventionally, there are a bed, a cart, a cart, etc. as a bed. For example, in a bed, casters are attached to four corners of the frame, and the bed can be manually moved to an arbitrary position. In addition, in order to fix the bed at the destination, a caster with a lock mechanism equipped with a brake that applies braking force to the wheels of the caster is provided, and the wheels of the caster are rotatable when moving, and when locked, the wheels are braked by the brake. (For example, refer to Patent Document 1).
JP-A-8-324206

  There are various mechanisms for locking and releasing when a caster with a lock mechanism is mounted on a bed as described above. An operation arm with a pedal that can be stepped on is provided at the bottom of the bed, and the operation arm is Some have been made easy to operate by making them operable.

  On the other hand, in the caster lock mechanism, the brake shoe is pressed against the wheel to be locked, the brake shoe is released to be unlocked, and the brake shoe is contacted and released using a rotating cam. There is. In that case, the rotation cam can be turned by a predetermined rotation angle in accordance with the shape of the peak / valley to switch between locking and release, and the mechanism for selectively rotating the rotation cam at a predetermined angle in conjunction with the operation arm with the pedal. And so on.

  In the interlocking mechanism between the operation arm with pedal and the rotation cam, in Patent Document 1, the operation is performed by rotating the rotation cam in one direction by depressing the operation arm with pedal and releasing the pedal. The rotating cam is reversed by performing the operation of returning the attached operation arm with the instep. Therefore, a burden is placed on the instep and ankle in the movement of the foot at the time of release, and there is no problem if the number of operations is small, but there is a problem that the burden becomes large when many beds are moved.

  In addition, two operation arms with pedals, a lock pedal and a release pedal, are provided side by side. For example, one operation arm with a pedal is gear-coupled to a rotating shaft that is coaxial and integral with the rotary cam, and the other operation arm with a pedal is connected to the other operation arm with a pedal. On the other hand, by engaging the gears via the idle gear, it is possible to lock and release by depressing each operation pedal alternately so that when one of them is depressed, the other returns. However, in this case, learning is necessary to determine which operating pedal is for locking or releasing, and it is difficult to say that the operation is easy.

  In addition, one operation arm with a pedal is provided, for example, a heart cam mechanism is provided, and the operation arm is also held in the depressed position so as to be locked when the pedal is depressed, and further depressed when released. In some cases, the holding of the operation arm is released and the locked state is also released. In this case, it is possible to determine whether the operation arm is locked or released, but for the sake of clarity, it is necessary to increase the amount of displacement of the operation arm, which makes the stepping posture difficult. There is a fear.

  In addition, in the case where casters are disposed at the four corners of the bed frame, for example, an operation arm with a pedal is provided on one side in the longitudinal direction of the bed, and all operations can be performed by operating the operation arm with the pedal. It is better to operate the caster lock mechanism. In that case, a rotation shaft is provided between the casters arranged in the width direction of the bed, and the rotation cams of these lock mechanisms are coupled to the rotation shaft coaxially to form a pair in the width direction. Synchronize. On the other hand, it is necessary to provide some kind of transmission mechanism between the lock mechanisms of the casters arranged in the longitudinal direction to synchronize the rotary cams.

  As a transmission mechanism for transmitting rotation, for example, there is a mechanism in which one connecting shaft is disposed between two rotating shafts separated in the longitudinal direction and a bevel gear is used between the connecting shaft and each rotating shaft. . However, in this case, there is a problem that there is a backlash of the gear, and the rotation cams of the lock mechanism disposed in the longitudinal direction may not be synchronized with each other. Alternatively, it is conceivable that radially outward arms are integrally provided on two rotating shafts separated in the longitudinal direction, and the arms are connected to each other via a wire. However, in this case, there is a problem that if the wire is stretched, it cannot be synchronized as described above.

  Separately from the transmission mechanism as described above, a gear is coaxially and integrally provided on the rotation cam for each caster, and engages in one rotation direction of the gear but escapes in the other rotation direction (reverse rotation). It is conceivable to provide the slide member provided with the triangular claw to be biased toward the engagement position. However, in the slide structure, since a part of the slide member appears and disappears with respect to the support portion of the housing, the sliding side of the support portion of the housing may be scraped or a smooth slide may be secured. There is a problem that foreign matter such as dust enters into the gap as the clearance, and the slidability deteriorates. In addition, there is a problem that the rotation amount of the rotary cam is lost by the amount of swing of the slide member due to the clearance.

In order to solve such problems and realize reliable operation and operability improvement of each lock mechanism in a bed or the like having a caster with a lock mechanism, in the present invention, a caster having a lock mechanism is provided. A caster-locking mechanism for a caster-equipped frame that is movable by a plurality of casters including a brake member that is detachably displaceable from a wheel of the caster, and the brake member selectively An operating arm that is pivotally supported on the caster-mounted frame so as to rotate by a predetermined angle and is biased by a spring toward the initial position; and The rotating cam and the operating arm are configured to advance the rotating cam by a predetermined angle by displacing the predetermined angle from the initial position against an urging force. A step mechanism provided between the brake members, and the brake member is switched to one of the engagement / disengagement states by the predetermined angle step of the rotary cam, and the operation arm is in any of the engagement / disengagement states. Is placed in the initial position by being biased by the spring.

In particular, the operation arm may be disposed at a position where the operation arm can be stepped on, and a pedal may be provided at the swing end of the operation arm. In addition, the operation arm has an identification display body having different forms of a lock display portion and a release display portion for making the lock state and the release state distinguishable, the lock display portion, and the release display portion. And at least one of the identification display body and the window is displaced according to the rotation of the rotating cam , and one of the lock display unit and the release display unit is selected. It would be better to be visible visually. The window may be provided in the vicinity of the pedal or the pedal of the operation arm. In addition, it is preferable that at least two casters each including the lock mechanism and the stepping mechanism are disposed, and the two stepping mechanisms are connected via a link mechanism so as to step in synchronism with each other. The link mechanism comprises a parallel link having a fixed joint that constitutes a part of the frame, and a cylinder that receives the link parallel to the fixed joint in a portion that forms the fixed joint of the frame in a displaceable manner. It is preferable that a body is formed. Further, it is preferable that at least one of the stepping mechanisms is provided with means for invalidating the stepping. Further, the stepping mechanism includes a pawl wheel coaxially and integrally provided on the rotating cam, and a pawl for meshing with the pawl wheel, and the means for invalidating the step is It is preferable that the release lever is provided integrally with the claw so as to disengage the claw from the engagement position with the claw wheel. Further, the operation pedal may be provided integrally with a link that constitutes a part of the link mechanism.

  As described above, according to the present invention, in a bed or the like provided with a caster with a lock mechanism for freely moving / fixing, the step is performed between the operation arm pivotally supported by the frame and the rotary cam of the lock mechanism. A mechanism is provided so that the rotating cam can be stepped by rotating at a predetermined angle from the initial position of the operating arm, and the operating arm is always spring-biased and always returns to the initial position. The lock mechanism can be repeatedly locked and released each time it is rotated by a predetermined angle. In this way, the operation arm can be switched between locking and releasing by always repeating the same operation in one direction, the operation is simplified, and only one operation arm needs to be provided. Since there is no need to provide an operation arm separately, there is no troublesome operation.

  Further, by providing a pedal on the operation arm so that the foot can be stepped on, the operation arm can be operated by a natural operation of stepping on, so that the burden of returning with the back of the foot can be eliminated and the work burden can be reduced. Further, the identification display body is displaced according to the rotation of the rotation shaft so that the identification according to the lock / release can be visually recognized. The locked or unlocked state of the attached caster can be easily visually confirmed. In addition, when the operation arm is made to be a stepping type, for example, in the bed, the operation arm is hidden by a mat or the like. It can be visually recognized and is suitable.

  In addition, when a lock mechanism is provided on two casters that are spaced apart from each other, both stepping mechanisms such as gears and wires are linked by linking each stepping mechanism via a link mechanism. There is no deviation between the rotating shafts, and synchronization can be ensured. Furthermore, the link mechanism is formed as a parallel link having a fixed joint that constitutes a part of the frame, and a cylindrical body is formed in a portion forming the fixed joint, and the link parallel to the fixed joint is received in a displaceable manner. The displacing link can be covered by the frame, and contact with the displacing link can be prevented.

  In addition, by providing means for invalidating the step in at least one of the step mechanisms, even if the synchronization is not possible, one of the step mechanisms can be put into a so-called idle state, and then both It is possible to synchronize the stepping mechanism and easily cope with the synchronization error. For example, in a bed with a four-wheel caster, if the four wheels are not locked synchronously for some reason, even if the display is locked, the bed may move, or conversely, for example, one wheel If it is only in the locked state, unexpected things such as dragging one wheel when the bed is moved will occur. In such a case, each step mechanism can be synchronized by means for invalidating the step, and the above problem can be avoided. In particular, the stepping mechanism is composed of a pawl wheel and a pawl, and the release lever is provided integrally with the pawl, so that the pawl can be moved away from the pawl wheel by operating the release lever. Means for disabling can be configured.

  Further, by providing the pedal integrally with the link constituting a part of the link mechanism, the link connected to the stepping mechanism can be used as a pedal, and it is not necessary to separately configure the pedal mechanism, so that the mechanism can be simplified. .

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic external view of a main part of a frame 1 provided at the lower part of the bed. In the frame 1 shown in the figure, when the longitudinal direction of the bed is the front-rear direction and the direction orthogonal to the plan view is the left-right direction, a pair of support members 2 extending in the front-rear direction extend, The front portions of the two support members 2 in the drawing are coupled via a rod-like member 3 extending in the left-right direction. A caster 4 with a lock mechanism is attached to each of the front and rear ends of both support members 2. In the figure, the structural portion for ensuring the rigidity of the frame 1 is not shown.

  The caster 4 with the lock mechanism may be a known one, and an example is shown in FIG. The caster 4 with a lock mechanism in FIG. 2 includes a cylindrical column 5 coupled to the support member 2, a wheel case 6 a that is coaxially and swingably mounted on the column 5 and supports the wheel 6, The lock mechanism 7 can selectively lock and release the rotation.

  The lock mechanism 7 includes a brake member 7a that is supported by the wheel case 6a so as to be swingable so as to be in contact with and away from the outer peripheral surface of the wheel 6 and is spring-biased in the direction of separation, and a column at the upper part of the column 5 in the figure. The rotary cam 7b is rotatably provided around an axis orthogonal to the axis 5 and the linear motion member 7c is provided in the column 5 so as to be freely slidable in the axial direction so as to be in sliding contact with the rotary cam 7b. The cam receiver 7d has a spring 7e that urges the cam receiver 7d in a direction to press the tip of the cam receiver 7d against the rotating cam 7b. In addition, a bevel gear 7f is integrally provided at the lower end portion of the linear motion member 7c in the drawing so as to face the back portion of the upper surface of the brake member 7a in the drawing, and the teeth of the bevel gear 7f are provided on the back portion of the brake member 7a. A receiving tooth 7g capable of meshing with a part is provided. The rotary cam 7b is formed as a cam having a shape in which peaks and valleys are alternately arranged in the circumferential direction as shown in the figure on the outer periphery, and the tip of the cam receiver 7d is also engaged in the mountain. Thus, the position can be maintained for each pitch of the peaks and valleys in a state where the rotating cam 7b is not rotated by an external force.

  FIG. 2 shows a state in which the cam receiver 7d is engaged with the valley of the rotating cam 7b. In this state, the linear motion member 7c (bevel gear 7g) is raised to the upper side of the figure, and the brake member 7a is a wheel. Since it is away from 6, the wheel 6 can rotate freely. On the other hand, in the state where the cam receiver 7d is engaged with the crest of the rotating cam 7b as shown in FIG. 3, the linear motion member 7c (bevel gear 7g) is lowered to the lower side of the figure, and the brake member 7a contacts the wheel 6, a braking force is applied to the wheel 6, and the wheel 6 is in a stopped state.

  A hexagon hole 8 is formed coaxially in the rotating cam 7b. Further, as shown in FIGS. 1 and 4, a rotating shaft 9 formed in a hexagonal cross section having the same shape as the hexagonal hole 8 is provided between the left and right casters 4 with a locking mechanism. The hexagonal holes 8 of the left and right rotating cams 7b are fitted to both ends of the rotating shaft 9, so that the left and right rotating cams 7b can rotate integrally with each other before and after the frame 1, respectively.

  Next, a lock mechanism operating device according to the present invention will be described. As shown in FIG. 1, a cylindrical member 11 that surrounds the rotating shaft 9 extends halfway in the axial direction of the rotating shaft 9 on the column 5 of the casters 4 with the right and left locking mechanisms on the rear side in the drawing of the frame 1. It is fixed to do. A pair of left and right operation arms 12 are pivotally supported by the left and right cylindrical members 11 thus provided as a part of the frame 1 so as to rotate coaxially with the rotation shaft 9. The operation arm 12 extends outward in the radial direction of the rotary shaft 9, and a long plate-like pedal 13 is attached between the extended ends of both operation arms 12 so as to extend in the left-right direction of the bed. ing. Further, the extension length of the operation arm 12 is set so that the pedal 13 can be easily stepped on in a state where a mat or the like is assembled to the frame 1.

  As shown in FIG. 5, the operation arm 12 is substantially L-shaped, and an end portion corresponding to a short side thereof is provided coaxially with the rotary shaft 9. A follower arm 14 is provided on the front side of the frame 2 so as to be coaxially rotatable with respect to the rotary shaft 9 provided in the same manner as the rear side. Note that. The follower arm 14 is formed in the same manner as the portion corresponding to the short side of the L-shape of the operation arm 12.

  A portion corresponding to the short side of the L shape of one of the left and right operating arms 12 and the driven arm 14 incorporate a pawl wheel device constituting a stepping mechanism. Both the handwheel devices built in the one arm 12 and the driven arm 14 may have the same configuration, and the one operation arm 12 will be described below as a representative. A pawl wheel 15 is coaxially fixed to the rotary shaft 9, and a pawl 16 having a tip portion that can be engaged with one of a plurality of teeth 15 a arranged to be inclined in one circumferential direction of the pawl wheel 15. The boss portion formed on the side wall of the operation arm 12 is supported so as to be swingable. The claw 16 is urged by a torsion coil spring 17 interposed between it and the peripheral wall of the operation arm 12 in the direction toward the teeth 15a. In this way, the stepping mechanism is configured.

  In addition, the support member 2 is a fixed node, and the front and rear arms 12 and 14 are connected via an interlocking rod 18 so that the operation arm 12 and the driven arm 14 are parallel links. In the support member 2, an intermediate portion excluding the support portion of the caster 4 is formed in a cylindrical body, and the interlocking rod 18 excludes the connection portions with the arms 12 and 14 and supports the support member 2. Is received in the cylindrical body part so as to be displaceable.

  Further, a tension coil spring 19 is connected between the rod-shaped member 3 and the driven arm 14, whereby the driven arm 14 is spring-biased toward the initial position. The initial position is a position where the operation arm 12 connected to the driven arm 14 via the interlocking rod 18 is flipped up. For example, as shown in FIG. 6A, the cylindrical member 11 is provided with a stopper 11a formed in a sector cross-sectional shape at an appropriate position in the axial direction thereof, and the operation arm 12 is rotated in its circumferential direction by the circumferential movement of the stopper 11a. Protrusions 12c that are in contact with both end faces are provided integrally. By adjusting the angles of the respective formation ranges of the stopper 11a and the protrusion 12c, the angle at which the operation arm 12 can be rotated is determined. The initial position is the position where the operating arm 12 is flipped up by the spring force of the tension coil spring 19 and the circumferential end surface of the protrusion 12c abuts the opposing circumferential end surface of the stopper 11a.

  In this way, the lock mechanism operating device is configured, and when the operating arm 12 is rotated in the direction of arrow A in FIG. Engages with the teeth 15a, and the pawl wheel 15, that is, the rotary shaft 9 can be rotated in the direction of arrow B in FIG. 5A by an amount corresponding to the rotation angle of the operation arm 12. Since the rotary shaft 9 and the rotary cam 7b rotate integrally, as shown in FIG. 2, for example, in the case of the rotary cam 7b provided with five peaks and valleys, the tip of the cam receiver 7d is rotated by 36 degrees. Moves relatively from the mountain to the valley or from the valley to the mountain, and the movement can displace the linear motion member 7c. The linear motion member 7c reciprocates according to the peak / valley of the cam, and the wheel 6 is switched to the locked or released (free rotation) state as described above.

  In addition, the predetermined angle which can be rotated by stepping on the operation arm 12 is regulated by the other end surface in the circumferential direction of the protrusion 12c coming into contact with the opposite circumferential end surface of the stopper 11a. The predetermined angle may be a value including an error with respect to the pitch (36 degrees in the illustrated example) between the peaks and valleys of the rotating cam 7b.

  When the lock and release are switched by the stepping operation shown in FIG. 7A, the operation is performed as shown in FIG. 7B by releasing the foot from the pedal 13 and by the spring force of the tension coil spring 19. The arm 12 is automatically returned to the initial position (direction of arrow C). At this time, since the pawl 16 moves in the inclination direction of the teeth 15a of the pawl wheel 15, the pawl 16 does not engage with the teeth 15a, and the rotary cam 7b integrated with the pawl wheel 15 is switched to either lock or release. Is kept in the state.

  In this way, each time the pedal 13 is depressed, the operation arm 12 swings, and the rotation cam 7b of the lock mechanism of the caster 4 is moved up and down according to the rotation of a predetermined angle (until it hits the stopper 11a) from the initial position. Can be rotated by the pitch of. By releasing the stepping on the pedal 13 (releasing the foot), the operating arm 12 returns to the initial position by the spring force of the tension coil spring 19 described above. Accordingly, the caster 4 can be locked and released by repeatedly depressing the pedal 13 in the initial position at all times. As in the prior art, the caster 4 can be lifted on the instep or operated separately. Therefore, the operability can be improved.

  In addition, a gear member is coaxially and integrally provided on the rotating cam 7b, and a slide member having a triangular claw that engages in one rotation direction of the gear but escapes in the other rotation direction (reverse rotation) is provided. In the case of a conventional structure that is spring-biased toward the engagement position, foreign matter is mixed into the slide part, or the backlash increases due to shaving during sliding, and the slidability deteriorates. In contrast to the above problem, the above-mentioned problem in the slide structure is unlikely to occur when the stepping is performed by the rotational movement using the pawl wheel 15 and the pawl 16 as in the illustrated example. Further, since the rotary cam 7b is rotated in one direction by the stepping mechanism, when five peaks / valleys are provided as in the illustrated example, wear due to sliding contact with each peak / valley is dispersed, and the rotary cam The durability of 7b can be improved.

  Next, the visual confirmation structure of the caster 4 locked and released according to the present invention will be described below. As shown in FIG. 8, in the operation arm 12, a cam 21 coaxially attached to the rotary shaft 9 and a shape of the operation arm 12 so as to reach a portion where the pedal 13 is provided from the cam 21. And a disc 23 as an identification display body rotatably supported by a portion where the pedal 13 is provided. The cam 21 may have a cam shape in which peaks and valleys are arranged at the same circumferential pitch as the cylindrical cam 7b, for example.

  The link member 22 is pivotally supported in the vicinity of the cam 21 so that a protruding portion 22a formed at one end portion on the cam 21 side performs a swinging motion that follows a mountain and a valley according to the rotation of the cam 21. . Further, in order to rotate the disk 23 by a predetermined rotation angle by the swing motion of the link member 22, a pin 23 a is projected at a predetermined position of the disk 23, and the other end of the link member 22 on the disk 23 side is provided at the other end. A long hole 22b that engages with the pin 23a is provided. A torsion coil spring 24 is provided between the pivot portion of the link member 22 and the intermediate portion of the disk 23 and the peripheral wall of the operation arm 22 so as to bias the projection 22a against the cam 21. Has been.

  Further, on the outer peripheral surface of the circular plate 23, for example, a red portion 23R colored in red as a lock display portion and a blue portion 23B colored in blue as a release display portion are arranged. A window 12a that allows only the red portion 23R or the blue portion 23B to be visible from the outside is provided in the peripheral wall portion that surrounds the disc 23 of the operation arm 12. Note that the window 12a is provided at a position that can be visually recognized when the operator approaches in a state where the operation arm 12 is positioned at an initial position (a state where the operation arm 12 is lifted up).

  In the locked state shown in FIG. 8A, the protruding portion 22a of the link member 22 contacts the peak of the cam 21, and the disk 23 is moved to the arrow D in the figure by the swinging displacement of the link member 22 moving from the valley to the peak. The red portion 23R faces the window 12a at that position. On the other hand, in the release state shown in FIG. 8B, the protruding portion 22a of the link member 22 comes into contact with the valley of the cam 21, and the rotational movement of the operation arm 12 for releasing releases the valley from the mountain. The disk 23 reverses by a predetermined rotation angle due to the rocking displacement of the link member 22 moving to, and the blue portion 23R faces the window 12a at that position.

  In the bed of the illustrated example, the rotating shaft 9 coupled to the caster 4, that is, the rotating cam 7 b is likely to be concealed by the mat or the like on the upper portion of the frame 1, and is displayed so as to rotate coaxially with the rotating shaft 9. When a body is provided, visual recognition becomes difficult. On the other hand, with the above structure, the operation arm 12 can be displayed in the vicinity of the pedal 13 that is directly depressed, so that it can be surely recognized during operation. Further, it can be displayed at an arbitrary position by setting the shape and extension length of the operation arm 12, and can easily cope with a bed having a different shape, and is highly versatile.

  Further, the form of the lock display part and the release display part is not limited to the above-described identification display, and may be various forms that can be identified (visually recognized). For example, it can be displayed as characters (locked, released), displayed as a picture, or displayed as an external shape. FIG. 9 shows an example of identifying by a difference in appearance shape. In addition, the same code | symbol is attached | subjected to the part similar to FIG. 8, and the detailed description is abbreviate | omitted. As shown in the figure, a projecting slide member 45 that is slidably supported at a suitable position of the disc 23 so as to be displaced in the radial direction, and the projecting slide member 45 is projected outward in the radial direction of the disc 23. A spring 46 is provided for biasing the strip. FIG. 9A shows a state corresponding to FIG. 8A. In this state, the protruding portion of the protruding slide member 45 protrudes outward from the window 12a. Then, when the release state is made in the same manner as described above and FIG. 8B, the projecting slide member 45 is moved from the position corresponding to the window 12a by the rotation of the disc 23 as shown in FIG. Since it is housed in the arm 12, the protruding portion disappears from the window 12a. Thus, the locked / released state can be visually recognized by the presence or absence of the protruding portion of the protruding slide member 45 in the window 12a. Further, by distinguishing the protruding portion of the protruding slide member 45 with red or the like, the distinguishability is further improved.

  Further, according to the present invention, the engagement between the pawl wheel 15 and the pawl 16 can be released, and an example of the structure is shown with reference to FIG. As shown in the figure, the pawl 16 is integrally provided with a shaft portion 16a coaxially with the rotation axis thereof, the shaft portion 16a projects outward from the operation arm 12, and a manual release lever 25 is coupled to the projecting end. ing. By turning the manual release lever 25 in the direction indicated by the arrow F in the figure, the pawl 16 also rotates integrally in the same direction, and the engagement of the pawl 16 with the pawl wheel 15 can be released. Note that a stopper 26 with which a part of the pawl 16 comes into contact protrudes at an appropriate position inside the operation arm 12 in order to restrict the operation range of the manual release lever 25 in the release direction. In this way, means for invalidating the step is provided.

  The torsion coil spring 17 generates a spring force in the direction in which the pawl 16 is engaged with the pawl wheel 15 in the stepping motion of the pawl 16, but as shown in FIG. When the pawl 16 is positioned, it is provided as a toggle spring that holds the release state shown in the drawing of the pawl 16 with respect to the pawl wheel 15.

  When the operation arm 12 is rotated in the direction in which the pedal 13 is depressed in the state of FIG. 11A, the rotational force is transmitted only to the driven arm 14 connected via the interlocking rod 18. Only the rotation shaft 9 of the rotation rotates by one pitch. Then, in the initial position state of the operation arm 12, the manual release lever 25 is rotated in the direction of arrow G as shown in FIG. 11 (b) to engage the pawl 16 with the teeth 15a of the pawl wheel 15, The operation arm 12 side is set to the state before the release operation. In this way, synchronization can be restored when there is a difference in locking and releasing between the casters 4 before and after the frame 1.

  The extended end of the manual release lever 25 can project from the operation arm 12 as shown in FIG. 11A when the manual release lever 25 is released. Thereby, the presence or absence of manual cancellation | release can be confirmed easily and an erroneous operation can be prevented, without providing a visual recognition mechanism separately. Further, as a means for invalidating the step by taking the manual release lever 25 as an example, in the illustrated example, two means are provided between the left and right casters 4 on the side where the operation arm 12 is provided (the back side of the bed). There is no need to use one. Further, two are not necessary between the left and right casters 4 on the side where the driven arm 14 is provided (front side of the bed), and only one is necessary. Furthermore, it suffices to be on either the side where the operation arm 12 is provided or the side where the driven arm 14 is provided, and at least one as a whole is sufficient.

  Further, the identification structure of the lock and release is not limited to that of the above illustrated example (FIGS. 8 and 9), and a third example is shown with reference to FIG. In addition, the same code | symbol is attached | subjected to the part similar to the said example of illustration, and the detailed description is abbreviate | omitted. In the third example, the same cam 21 may be used, and a rocking lever 31 that follows the peaks and valleys of the cam 21 is provided. The swing lever 31 is pivotally supported at the upper end portion in the figure on the cam 21 side, one end portion of the slide member 32 as an identification display body is connected to the lower end portion in the figure, and the mountain / Protruding portions 31a that abut the valleys are provided. In addition, a tension coil spring 33 is provided that biases the protrusion 31a in a direction in which the protrusion 31a abuts against a peak / valley of the cam 21.

  The operation arm 12 is substantially L-shaped as shown in the figure, and its short side portion is pivotally supported coaxially with the rotary shaft 9, and a pedal similar to the above is provided at the end of the long side portion. 13 is fixed. The slide member 32 is provided so as to reciprocate substantially along the upper wall portion of the long side portion of the operation arm 12 in accordance with the swing motion of the swing lever 31. On the other hand, a plurality of windows 12 b are arranged at predetermined intervals in the sliding direction of the slide member 32 on the upper wall portion of the long side portion of the operation arm 12. On the surface of the slide member 32 facing the window 12b, the same number of red portions 32R and blue portions 32B as those described above are arranged in the same number as the number of windows 12b.

  Thereby, according to the slide position of the slide member 32, any one of the red part 32R and the blue part 32B faces the window 12b, and there can exist an effect similar to the above.

  A fourth example is shown with reference to FIG. Also in this example, the same parts as those in the illustrated example are denoted by the same reference numerals, and detailed description thereof is omitted. In the fourth example, for example, a plate-like member 41 is rotatably received in the pedal 13, and pulleys 42a and 42b are attached to the rotary shaft 9 and the plate-like member 41, respectively. A belt 43 spanned between 42 b is received in the operation arm 12. Further, a red portion 44R is provided at an appropriate position on one surface of the plate-like member 41, and a blue portion 44B is provided at a corresponding portion on the other surface, and a window 13a is provided at a corresponding position on the front side of the pedal 13. Has been established.

  Even in this example, the plate-like member 41 rotates as the rotary shaft 9 rotates, and the plate-like member 41 reverses according to the repetition of the peaks and valleys of the rotating cam 7b by optimizing the pulley ratio. The red portion 44R or the blue portion 44B can face the window 13a. In this case, since the state is directly displayed on the pedal 13, it is possible to recognize the state easily and surely by simply moving the eyes to the pedal 13 when depressing.

  In the illustrated example, the rotating cams 7b of the casters 4 in the left-right direction of the frame 1 are connected by the rotating shaft 9, but the front-rear directions are connected by the same rotating shaft and the left-right directions are connected by a link. good.

  Further, in the link mechanism, since the operation arm 12 is provided with the step 16 of the stepping mechanism, the operation arm 12 becomes a part of the stepping mechanism, but the operation arm 12 and the stepping mechanism are separated. As a result, the displacement of the operation arm 12 can be transmitted to the stepping mechanism via the gear transmission mechanism. In that case, the gear of the gear transmission mechanism becomes a part of the stepping mechanism, and the same stepping motion can be performed by connecting the gears with a link, and the operation arm 12 can be rotated by changing the gear ratio. The predetermined angle of the rotating cam 7b corresponding to the step can be adjusted with respect to the angle.

  The caster lock mechanism such as a bed according to the present invention can be easily operated to lock and release the caster by one operation of the operation arm, and is useful as a bed in hospitals, various carts for transportation, and the like.

It is a figure which shows the flame | frame of the bed to which this invention was applied. It is a longitudinal cross-sectional view of the cancellation | release state which fractures | ruptures and shows the principal part of a caster with a locking mechanism. It is a figure corresponding to FIG. 2 which shows a locked state. It is a principal part front view which shows the state which stepped on seen from the arrow III line of FIG. It is a figure which shows the inside of the operation arm and follower arm which fractured | ruptured along the arrow VV line | wire of FIG. 3 in an initial position state. It is the figure which fractured | ruptured the principal part along the arrow VI-VI line of FIG. 3, (a) is a figure corresponding to the initial position of an operation arm, (b) is the position which rotated the operation arm by the predetermined angle. It is a corresponding figure. (A) is a figure corresponding to FIG. 4 which rotated the operation arm by the predetermined angle, (b) is a figure corresponding to (a) which shows the state in the middle of returning the operation arm. (A) is a figure which shows the inside of the operation arm shown fractured | ruptured along the arrow VIII-VIII line of FIG. 3 in an initial position state, (b) is a figure corresponding to (a) rotated by a predetermined angle. is there. It is a figure which shows the example identified by a shape change, (a) is a figure corresponding to Fig.8 (a), (b) is a figure corresponding to FIG.8 (b). It is a principal part perspective view which shows a manual release lever. (A) is a figure which shows the state which canceled the nail | claw of the nail | claw wheel, (b) is a figure which shows an engagement state. It is a figure which shows the 2nd example of the identification structure of a lock | rock and cancellation | release. It is a perspective view which shows the 3rd example of an identification structure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Frame 2 Support member 3 Rod-shaped member 4 Caster 5 Support | pillar 6 Wheel, 6a Wheel case 7 Lock mechanism 7a Brake member 7b Rotating cam 7c Linear motion member 7d Cam receiver 7e Spring 7f Bevel gear 7g Tooth receiving 8 Hexagonal hole 9 Rotating shaft 11 Cylinder Member, 11a stopper 12 operation arm, 12a window, 12b window, 12c protrusion 13 pedal, 13a window 14 driven arm 15 tooth wheel, 15a tooth 16 pawl, 16a shaft 17 torsion coil spring 18 interlocking rod 19 tension coil spring 21 cam 22 Link member, 22a Protruding portion 23 Disc, 23a Pin 23R Red portion, 23B Blue portion 24 Torsion coil spring 25 Manual release lever 26 Stopper 31 Swing lever, 31a Protruding portion 32 Slide member 32R Red portion, 32B Blue portion 33 Tension coil spring 41 Plate-like members 42a and 42b Over Li 43 belt 44R red portion, 44B blue portion 45 protruding slide member 46 spring

Claims (9)

A caster-locking mechanism of a frame with casters that is movable by a plurality of casters including a caster with a locking mechanism,
The lock mechanism includes a brake member that is detachably disengaged from a wheel of the caster, and a rotating cam that selectively drives the brake member to the engagement / disengagement state;
An operating arm pivotally supported by the caster frame so as to be rotatable by a predetermined angle from an initial position and spring-biased toward the initial position;
A step provided between the rotating cam and the operating arm to move the rotating cam a predetermined angle by displacing the operating arm from the initial position by the predetermined angle against the spring biasing force. A mechanism,
The brake member is switched to either the engaged state or the disengaged state by the predetermined angle step of the rotating cam, and the operating arm is biased by the spring and positioned at the initial position in any of the engaged and disengaged states. A caster lock mechanism for a frame with casters. The caster lock mechanism for a caster-equipped frame according to claim 1, wherein the operation arm is disposed at a position where the operation arm can be stepped on, and a pedal is provided at a swinging end portion of the operation arm. An identification display body having a lock display portion and a release display portion of different forms for enabling the operation arm to distinguish between the lock state and the release state, and one of the lock display portion and the release display portion And a window that makes it visible
The at least one of the identification display body and the window is displaced according to the rotation of the rotary cam , and one of the lock display unit and the release display unit is selectively visible. A caster locking mechanism for a caster-equipped frame according to claim 1 or 2. The caster lock mechanism for a caster-equipped frame according to claim 3, wherein the window is provided in the vicinity of the pedal or the pedal of the operation arm. At least two casters including the locking mechanism and the stepping mechanism are disposed;
The caster locking mechanism for a caster-equipped frame according to any one of claims 1 to 4, wherein the two stepping mechanisms are connected via a link mechanism so that the stepping mechanisms can step in synchronization with each other. . The link mechanism comprises a parallel link having a fixed joint constituting a part of the frame,
The caster of the frame with casters according to claim 5, wherein a cylindrical body that receives a link parallel to the fixed joint so as to be displaceable is formed in a portion of the frame forming the fixed joint. Lock mechanism. The caster lock mechanism for a caster-equipped frame according to claim 5 or 6, wherein means for invalidating the step is provided in at least one of the stepping mechanisms. The step mechanism includes a pawl wheel coaxially and integrally provided on the rotary cam, and a pawl for engaging with the pawl wheel;
8. The caster according to claim 7, wherein the means for invalidating the step is a release lever provided integrally with the claw so as to disengage the claw from the engagement position with the claw wheel. Caster lock mechanism with attached frame . The caster lock mechanism for a caster-equipped frame according to any one of claims 5 to 8, wherein the pedal is provided integrally with a link constituting a part of the link mechanism.

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