Patent Description:
In the related art, in the medical field, a flexible medical tube is used as a tube element which is a part of an extracorporeal circulation circuit of a body fluid such as blood, an auxiliary circuit connected to the extracorporeal circulation circuit, an infusion line of medical fluid, or the like. In some cases, the medical tube is equipped with a clamp for pressing and occluding the tube at a desired position. As the clamp applied for the medical tube, a clamp which is made of a resin and which can be manipulated with one hand is known.

For example, Patent Document <NUM> discloses a clamp made of a resin, wherein a protrusion that presses a tube is formed on each of opposing surfaces of two plates which are connected to each other, and there is provided a locking unit that fixes the plates at positions at which the plates are closer to each other and that maintains an occluded state of the tube. The locking unit fixes (locks) the plates in a state in which the two plates are closer to each other and press the tube, to thereby maintain the occluded state of the tube. The clamp disclosed in Patent Document <NUM> has a centering function to guide the plates to predetermined normal positions so that the plates do not significantly deviate from the predetermined position at which a normal locked state is realized.

In some cases, the medical tube is not viewed while being manipulated, the clamp is locked, and the tube is not pressed normally. In this case, an occlusion property of the tube is reduced and leakage is caused. As a mechanism for preventing such a situation, the clamp of Patent Document <NUM> discloses a centering function for guiding the plates to normal positions. However, as a result of various reviews of the clamp of Patent Document <NUM>, it was newly found that, in some cases, when the clamp is used for a tube of a large outer size, the clamp is locked while the centering function fails to be sufficiently realized. Specifically, a tube having a large outer size elastically deforms by the protrusions of the clamp at an early stage in the clamp manipulation. Because of this, a frictional force between each protrusion and the tube becomes significantly large due to a reaction force of the tube and an increase in a contact area in a width direction caused by widening of the tube in the width direction. Thus, a situation has been observed in which, even when the centering function acts, the plates do not move relative to each other in the width direction, due to the frictional force. In such cases, due to the structure of the centering function, the clamp should not be locked, because the plates which do not move relative to each other in the width direction also do not move in the direction toward each other. However, a situation was newly found in which, when an excessive pressurization force is applied to an end of the plate in the width direction, connecting portions deform while the plates are in a deviated state, the plates are thus inclined, a corner of the plate is locked to a locking portion, and the clamp is locked in a non-centered state.

According to the present invention, there is provided a medical tube clamp that presses and occludes a flexible medical tube, the medical tube clamp comprising: a first plate on which a first protrusion is formed; a second plate placed opposing the first plate, and on which a second protrusion that presses the medical tube along with the first protrusion is formed; a connecting portion that connects one end of the first plate in a length direction and one end of the second plate in a length direction, and that can elastically deform so as to cause the plates to be closer to each other; and a locking unit that is formed extending from the first plate toward the second plate, that locks the other end of the second plate in the length direction, and that maintains an occluded state of the medical tube, wherein a pair of sidewalls that extend in a standing manner are formed on respective ends in the width direction on the first plate, a sloped surface is formed on the second plate, the sloped surface being inclined toward the first plate from both ends in the width direction toward the center in the width direction of the second plate, and an inclination angle θ of the sloped surface with respect to the width direction of the second plate is <NUM>° ~ <NUM>°.

A medical tube clamp according to an aspect of the present invention desirably has a structure in which the second plate is inclined with respect to the first plate in an unlocked state so that a spacing between the two plates which press the tube is widened at the other end side in a length direction distanced from the connecting portion. In addition, the medical tube clamp according to an aspect of the present invention is desirable for a medical tube having a large outer size. For example, the medical tube clamp is desirable for a medical tube having an outer size which is equivalent to or larger than a spacing between the first protrusion and the second protrusion of the clamp before assembly; that is, a medical tube in which the first protrusion and the second protrusion of the clamp are in contact with an outer surface of the medical tube in the unlocked state. In the medical tube clamp according to an aspect of the present invention, the other end in the length direction of the second plate is pushed toward the first plate so that the spacing between the first protrusion and the second protrusion of the plates is reduced and the tube is pressed. The other end in the length direction of the second plate which is pushed is locked by the locking unit, to thereby maintain the locked state in which the tube is occluded.

With the medical tube clamp having the above-described structure, when an inappropriate manipulation is performed such as pushing the second plate in a slanted direction, the sloped surface of the second plate contacts the side wall of the first plate, and a contact point of the sloped surface with the side wall slides toward an upper end of the sloped surface. As a result, the second plate moves to an inner side of the clamp. That is, even when an inappropriate manipulation is performed, the second plate can be centered at the normal position at which the tube can be reliably occluded, and the normal locked state can be easily secured. Therefore, with the medical tube clamp having the above-described structure, the medical tube can be occluded quickly and reliably.

In the medical tube clamp according to an aspect of the present invention, the inclination angle θ of the sloped surface is <NUM>° ~ <NUM>°, and the sloped surface is a steeply inclined surface. Thus, a force in a lateral direction which acts from the inclined surface to the side wall is large. As a result, even in a case where the outer size of the medical tube is large or the like, the second plate is guided to the inner side against the frictional force, and, when an inappropriate manipulation is performed such as pushing the second plate in the slanted direction, the normal locked state can be easily secured. The inclination angle θ of the sloped surface is desirably <NUM>° ~ <NUM>°, and is more desirably <NUM>° ~ <NUM>°. According to this configuration, a force necessary for the centering of the second plate is significantly reduced, and smoother centering can be enabled. As a result, in a case where an inappropriate manipulation is performed such as pushing the second plate in the slanted direction, the normal locked state can even more easily secured.

Alternatively, a configuration may be employed in which one of the first protrusion and the second protrusion is more sharply pointed than the other of the first protrusion and the second protrusion. As a result, the force necessary for pressing the medical tube can be reduced, maneuverability can be improved, and an occlusion property of the medical tube can be improved. Because of this, a desirable clamp can be realized even for a medical tube having a small outer size for which occlusion is relatively difficult.

According to an aspect of the present invention, a medical tube clamp can be provided in which the tube can be more reliably occluded even when an inappropriate manipulation is performed, while securing superior maneuverability. With the medical tube clamp of the present invention, for example, when a manipulation is performed such as pushing the second plate in a slanted direction, the second plate can be centered at the normal position at which the tube can be reliably occluded, and the normal locked state can be easily secured.

An embodiment of the present invention will now be described in detail with reference to the drawings. The embodiment described below is merely exemplary, and the present invention is not limited to the embodiment. In the present invention, unless otherwise noted, a description of "a numerical value (A) ~ a numerical value (B)" means a value of greater than or equal to the numerical value (A) and less than or equal to the numerical value (B).

In the following, a case is exemplified in which a medical tube clamp <NUM> (hereinafter simply referred to as a "clamp <NUM>") according to an embodiment of the present invention is equipped on a medical tube <NUM> exemplified in <FIG> or the like, but, alternatively, the clamp <NUM> may be applied to other medical tubes such as a tube having a smaller diameter than the medical tube <NUM>. The medical tube on which the clamp <NUM> is equipped is a part of, for example, an extracorporeal circulation circuit, an auxiliary circuit, an infusion line, or the like.

<FIG> is a perspective diagram of the clamp <NUM>, and <FIG> is a side view of the clamp <NUM>. <FIG> are diagrams showing states in which the clamp <NUM> is equipped on the medical tube <NUM>. <FIG> shows an unlocked state in which the medical tube <NUM> is not pressed or occluded, and <FIG> shows a locked state in which the medical tube <NUM> is pressed and occluded, and a second plate <NUM> is locked by a locking unit.

As shown in <FIG>, the clamp <NUM> is a molded structure made of a resin and having a first plate <NUM> on which a first protrusion <NUM> is formed, and the second plate <NUM> which is placed opposing the first plate <NUM> and on which is formed a second protrusion <NUM> which presses the medical tube <NUM> along with the first protrusion <NUM>. The clamp <NUM> presses and occludes the medical tube <NUM> with the two plates. The second plate <NUM> is placed opposing the first plate <NUM> with a gap between the second plate <NUM> and the first plate <NUM> through which the medical tube <NUM> can be passed. Each of the first plate <NUM> and the second plate <NUM> has an approximate rectangular shape.

In the following, for the convenience of description, each of one end in a length direction of the first plate <NUM> and one end in a length direction of the second plate <NUM> connected by a connection portion <NUM> to be described below is referred to as a "base end", and each of the other ends in the length direction opposite from the base ends is referred to as a "tip end". The terms base end and tip end are similarly used for the clamp <NUM>. Further, a direction along the length direction of each plate will be referred to as a "vertical direction" of the clamp <NUM>, a direction along a width direction will be referred to as a "lateral direction", and a direction orthogonal to the vertical direction and the lateral direction will be referred to as an "up-and-down direction".

The clamp <NUM> is equipped at a desired position of the medical tube <NUM> in a state in which the length direction of each plate is along a length direction of the medical tube <NUM>. The clamp <NUM> has a structure in which a spacing between the first plate <NUM> and the second plate <NUM> which press the medical tube <NUM> is widened at a tip end side of each plate, in an unlocked state in which the medical tube <NUM> is not occluded. In the clamp <NUM>, a tip end portion of the second plate <NUM> is pressed toward the first plate <NUM> to reduce the spacing between the plates, so that a spacing X between the first protrusion <NUM> and the second protrusion <NUM> is reduced and the medical tube <NUM> is occluded. Here, the spacing X means a length along the up-and-down direction, from an upper end of the first protrusion <NUM> to a lower end of the second protrusion <NUM>.

The clamp <NUM> has the connecting portion <NUM> which connects the tip end portions of the first plate <NUM> and the second plate <NUM>. The connecting plate <NUM> is elastically deformable in the up-and-down direction so as to cause the first plate <NUM> and the second plate <NUM> to be closer to each other. In the clamp <NUM>, with the elastic deformation of the connecting portion <NUM>, when the second plate <NUM> is pressed or the pressing force is released, the spacing X between the first protrusion <NUM> and the second protrusion <NUM> changes, and the medical tube <NUM> is opened or closed.

The connecting portion <NUM> largely curves toward an outer side of the clamp <NUM>, and is formed in an approximate U shape in side view. The spacing between the first plate <NUM> and the second plate <NUM> can be adjusted by changing a length in the up-and-down direction of the connecting portion <NUM> (diameter of an arc). A tube pass-through hole <NUM> is formed on the connecting portion <NUM> in a wide area other than respective end portions in the width direction. By forming the tube pass-through hole <NUM> large, it becomes possible to facilitate equipment of the clamp <NUM> on the medical tube <NUM>, and to reduce rigidity of the connecting portion <NUM>, which facilitates elastic deformation of the connecting portion <NUM>.

In addition, the clamp <NUM> includes a locking portion <NUM> formed extending from the first plate <NUM> toward the second plate <NUM>. The locking portion <NUM> is a locking unit which locks the tip end portion of the second plate <NUM> and maintains the occluded state of the medical tube <NUM>. On a tip end portion of the locking portion <NUM>, a hook <NUM> protruding to an inner side of the clamp <NUM> is formed, on which the tip end portion of the second plate <NUM> is hooked. In the present embodiment, a slanted surface inclined toward the inner side of the clamp <NUM> and in a slanted downward direction is formed at the tip end portion of the locking portion <NUM>, and a lower end of the slanted surface protrudes to the inner side of the clamp <NUM> to form the hook <NUM>. The slanted surface and the hook <NUM> are formed over the entire width of the locking portion <NUM>.

The locking portion <NUM> is a plate-shaped portion extending from the tip of the first plate <NUM> in the upward direction, and is formed to have the same width as the first plate <NUM>. In the present embodiment, the first plate <NUM>, the second plate <NUM>, the connecting portion <NUM>, and the locking portion <NUM> are formed to have the same width, and, in the unlocked state and in the normal locked state, center parts of the two plates in the width direction overlap each other in the up-and-down direction. The locking portion <NUM> has a shape in which a base end portion close to the first plate <NUM> is curved toward the outer side of the clamp <NUM>, and a tip end portion is slightly inclined toward the inner side. Moreover, a tube pass-through hole <NUM> is formed on the locking portion <NUM>, similar to the connecting portion <NUM>.

The locking portion <NUM> elastically deforms in the vertical direction of the clamp <NUM>. When the tip end portion of the second plate <NUM> is pushed toward the first plate <NUM>, the tip end portion contacts the slanted surface formed on the tip end portion of the locking portion <NUM>, to thereby elastically deform the locking portion <NUM> toward the outer side, and the tip end portion moves over the hook <NUM> and close to the first plate <NUM>. At this point, the locking portion <NUM> is restored to its original shape, and, when a hand is moved off from the second plate <NUM>, the tip end portion of the second plate <NUM> is hooked and locked on the hook <NUM>, and a locked state is realized in which the medical tube <NUM> is occluded.

On the other hand, when the tip end portion of the locking portion <NUM> is pushed to the outer side and is elastically deformed in the locked state, the second plate <NUM> is released from the hook <NUM> and the locked state is released. The second plate <NUM> returns to the position of the unlocked state due to a restoration force of the connecting portion <NUM>. In the clamp <NUM> in the unlocked state, an opening <NUM> is formed between the tip end portion of the second plate <NUM> and the tip end portion of the locking portion <NUM>. In the locked state, the opening <NUM> does not exist, and the first plate <NUM>, the connecting portion <NUM>, the second plate <NUM>, and the locking portion <NUM> are connected in an annular shape.

The clamp <NUM> is equipped on the medical tube <NUM> by passing the medical tube <NUM> through the tube pass-through holes <NUM> and <NUM> of the connecting portion <NUM> and the locking portion <NUM>, in a state in which the medical tube <NUM> is sandwiched between the first plate <NUM> and the second plate <NUM>. In this process, the clamp <NUM> is equipped in such a manner that the medical tube <NUM> passes through a region between the first protrusion <NUM> of the first plate <NUM> and the second protrusion <NUM> of the second plate <NUM>. Therefore, the spacing X between the first protrusion <NUM> and the second protrusion <NUM> is set to be larger than the diameter of the medical tube onto which the clamp is equipped.

The first plate <NUM> and the second plate <NUM>, in particular, a structure related to a centering function of the second plate <NUM>, will now be described in detail.

As described above, on the first plate <NUM>, the first protrusion <NUM> which presses the medical tube <NUM> is formed. The first protrusion <NUM> is formed protruding toward the second plate <NUM> on an opposing surface <NUM> which opposes the second plate <NUM>. In the present embodiment, the first protrusion <NUM> is formed over an entire width of the first plate <NUM> at a center part in the length direction of the first plate <NUM>. In addition, a tip portion of the first protrusion <NUM> which contacts the medical tube <NUM> is formed in a rounded, semispherical shape in a side view of the clamp <NUM>.

On an outer surface of the first plate <NUM> opposite from the opposing surface <NUM>, there is no large protrusion similar to the first protrusion <NUM>. When the clamp <NUM> is locked, for example, the first plate <NUM> and the second plate <NUM> are pinched from above and below the structure, and pressure is applied to the second plate <NUM>. Thus, a small unevenness <NUM> for preventing slippage is formed on the outer surface of the first plate <NUM>. The thickness of the first plate <NUM> is, for example, about <NUM> ~ <NUM> in a flat portion where there is no large unevenness (this is similarly applicable to the second plate <NUM>).

A pair of sidewalls <NUM> which extend in a standing manner are formed at respective ends in the width direction of the first plate <NUM>. The pair of sidewalls <NUM> are formed to protrude toward the second plate <NUM> and to be higher than the first protrusion <NUM> on the opposing surface <NUM> of the first plate <NUM>. Meanwhile, each of the sidewalls <NUM> is formed in a height and a width such that a length in the up-and-down direction (height) is shorter than a length of the locking portion <NUM> in the up-and-down direction, and the sidewall <NUM> does not contact the second plate <NUM> in the unlocked state and in the normal locked state.

The pair of sidewalls <NUM> is a structure related to the centering function of the second plate <NUM>, and the second plate <NUM> is centered such that a centering guide <NUM> to be described below is positioned between the pair of sidewalls <NUM>. The sidewalls <NUM> are desirably formed to be high in a range of not obstructing an appropriate locking manipulation, from the viewpoint of improving the centering function. In addition, the sidewalls <NUM> are formed in a thickness within a range of not obstructing an appropriate locking manipulation; that is, in a thickness to not interfere with the centering guide <NUM> when the pressure is applied on the second plate <NUM> straight toward the first plate <NUM>.

The pair of sidewalls <NUM> are identical in shape and size, and are formed between a tip of the first plate <NUM> and the first protrusion <NUM>, aligned in the width direction of the first plate <NUM>. In the present embodiment, each of the sidewalls <NUM> is formed at a side nearer to the tip of the clamp <NUM> than the second protrusion <NUM> of the second plate <NUM>, and an upper end of each of the sidewalls <NUM> is positioned at an upper position than a lower end of the second protrusion <NUM> in the unlocked state. An upper end surface of the sidewall <NUM> is formed, for example, parallel to the opposing surface <NUM> of the first plate <NUM>. The sidewall <NUM> also functions as a tube guide for preventing squeezing-out of the medical tube <NUM> to the lateral direction from between the two plates.

As described above, on the second plate <NUM>, the second protrusion <NUM> which presses the medical tube <NUM> is formed. The second protrusion <NUM> is formed protruding toward the first plate <NUM> on an opposing surface <NUM> which opposes the first plate <NUM>. In the present embodiment, the second protrusion <NUM> is formed over the entire width of the second plate <NUM> at a center part in the length direction of the second plate <NUM>. In addition, a tip end portion of the protrusion <NUM> which contacts the medical tube <NUM> is more sharply pointed than the first protrusion <NUM>, and the protrusion <NUM> is formed in an approximate V shape in side view. In this case, the force necessary for pressing the medical tube <NUM> is reduced, the maneuverability is improved, and the occlusion property of the medical tube <NUM> is improved. Such a shape particularly desirably acts on a medical tube having a small outer size. A lower end of the second protrusion <NUM> is desirably chamfered so as to not damage the medical tube. Alternatively, the tip end portion of the first protrusion <NUM> may be more sharply pointed than the second protrusion <NUM>.

The lower end of the second protrusion <NUM> is positioned at a side nearer to the tip of the clamp <NUM> than the upper end of the first protrusion <NUM>. With the placement of the protrusions in a shifted manner in the vertical direction such that the first protrusion <NUM> and the second protrusion <NUM> are not aligned in the up-and-down direction, even when the medical tube <NUM> is pressed by the sharply pointed second protrusion <NUM>, the medical tube <NUM> tends not to be damaged, and the occlusion property of the medical tube <NUM> can be improved.

A pair of tube guides <NUM> protruding from respective ends in the width direction of the opposing surface <NUM> toward the first plate <NUM> are formed between the base end of the second plate <NUM> and the second protrusion <NUM>. The pair of tube guides <NUM> prevent squeezing-out of the medical tube <NUM> in the lateral direction from between the two plates. In addition, similar to the first plate <NUM>, a small unevenness <NUM> for preventing slippage is formed on an outer surface of the second plate <NUM>.

On the opposing surface <NUM> of the second plate <NUM>, a sloped surface which is inclined to be closer to the first plate <NUM> from the ends in the width direction toward the center in the width direction is formed. That is, the sloped surface is inclined with respect to the width direction in such a manner that the ends in the width direction of the second plate <NUM> are upper ends, and the center in the width direction is the lower end.

The sloped surface is formed to contact the sidewall <NUM> of the first plate <NUM> when an inappropriate locking manipulation is performed such as pushing the second plate <NUM> in a slanted direction. As will be described below in detail, with the sloped surface contacting the sidewall <NUM>, the second plate <NUM> slides toward an inner side of the clamp <NUM>, and the centering of the second plate <NUM> is performed. The sloped surface is desirably formed to be symmetric in the left and right with respect to the center in the width direction of the second plate <NUM>. In this case, the same centering process is applied in cases where the second plate <NUM> is pushed in a slanted direction to the left and to the right.

The sloped surface of the present embodiment includes a first sloped surface <NUM> and a second sloped surface <NUM> having a smaller inclination angle θ than the first sloped surface <NUM>, and the centering guide <NUM> is formed from the two sloped surfaces. The centering guide <NUM> (sloped surface) is formed between the tip of the second plate <NUM> and the second protrusion <NUM>. Alternatively, the centering guide may be formed from one sloped surface (for example, only the first sloped surface <NUM>), or may be formed from three or more sloped surfaces having different inclination angles θ from each other.

The centering guide <NUM> is formed in a slanted direction with respect to the opposing surface <NUM> from a region near the tip of the second protrusion <NUM> protruding toward the first plate <NUM> to a region near the tip of the second plate <NUM>. In the present embodiment, in the side view of the clamp <NUM>, the opposing surface <NUM>, the second protrusion <NUM>, and the centering guide <NUM> are placed to respectively form one side of a triangle. In a region surrounded by the opposing surface <NUM>, the second protrusion <NUM>, and the centering guide <NUM>, a reinforcement rib <NUM> having an approximate triangular shape in side view is formed. The reinforcement rib <NUM> is formed to be higher toward the second protrusion <NUM> in the center part in the width direction of the second plate <NUM>.

According to the invention, a biting-prevention piece <NUM> protruding toward the first plate <NUM> is formed on the opposing surface <NUM> of the second plate <NUM>. The biting-prevention piece <NUM> extends beyond a tip end position of the locking portion <NUM> toward the first plate <NUM>. Because the opening <NUM> is formed between the second plate <NUM> and the locking portion <NUM> of the clamp <NUM>, for example, a situation may be considered in which, during transport or storage, another clamp <NUM> enters the inside of the clamp <NUM>, and the clamps cannot be easily separated. With the provision of the biting-prevention piece <NUM>, such a disadvantage can be avoided.

The biting-prevention piece <NUM> is formed along the length direction from the tip of the second plate <NUM> to the second protrusion <NUM> at the center part in the width direction of the opposing surface <NUM>. With a connecting portion with the biting-prevention piece <NUM> on the second sloped surface <NUM> of the centering guide <NUM> being a lower end, the second sloped surface <NUM> is divided by the biting-prevention piece <NUM> into a one-end side and the other-end side in the width direction of the second plate <NUM>. On the other hand, the lower end of the first sloped surface <NUM> formed at the center part in the width direction of the opposing surface <NUM> protrudes beyond a lower end of the biting-prevention piece <NUM> toward the first plate <NUM>, and is thus not divided by the biting-prevention piece <NUM>. Alternatively, the biting-prevention piece <NUM> may be omitted.

A structure of the centering guide <NUM> will now be described in detail with reference to <FIG> is a cross-sectional diagram along a line AA in <FIG>, and <FIG> is a cross-sectional diagram along a line BB in <FIG>.

As shown in <FIG>, the centering guide <NUM> is formed to be positioned at the inside of the pair of sidewalls <NUM> formed on the first plate <NUM> in the normal locked state. That is, on the opposing surface <NUM> of the second plate <NUM>, the centering guide <NUM> is formed in a region not overlapping the pair of sidewalls <NUM> in the up-and-down direction. With this configuration, when an appropriate locking manipulation is performed to push the second plate <NUM> straight, interference between the sidewall <NUM> and the centering guide <NUM> is prevented.

As shown in <FIG>, the sloped surface (the first sloped surface <NUM> and the second sloped surface <NUM>) of the centering guide <NUM> is inclined by a predetermined angle θ with respect to the width direction of the second plate <NUM>. A pair of the first sloped surfaces <NUM> are provided, forming an approximate V-shaped portion. The first sloped surfaces <NUM> are formed in such a manner that a vertex of the approximate V-shaped portion is positioned at an upper position in relation to the second protrusion <NUM>, so as to reduce influences of the approximate V-shaped portion on the tube during the clamping. In addition, the sloped surfaces are formed in such a manner that the sloped surfaces can contact the pair of the sidewalls <NUM> when the spacing X between the first protrusion <NUM> and the second protrusion <NUM> is reduced by <NUM>% ~ <NUM>%. As described above, when the appropriate locking manipulation is performed, the sloped surface does not contact the sidewalls <NUM>. In other words, the sloped surfaces are formed in such a manner that the sloped surfaces contact the sidewalls <NUM> when the second plate <NUM> is pushed in the direction in which the plates move toward each other in a state in which the second plate <NUM> is deviated in the lateral direction with respect to the first plate, and the spacing X is reduced by <NUM>% ~ <NUM>%.

Respective ends in the width direction of the first sloped surface <NUM> and the second sloped surface <NUM> are desirably placed near a position immediately above the sidewalls <NUM> in a range not obstructing the appropriate locking manipulation, and, in some configurations, may be formed immediately above the sidewalls <NUM>. In the present embodiment, positions of the respective ends in the width direction of the first sloped surface <NUM> and the second sloped surface <NUM> coincide with each other, and the sloped surfaces are formed at a side slightly nearer to the center in the width direction of the second plate <NUM> than the positions immediately above the sidewalls <NUM>.

The inclination angle θ of the sloped surface of the centering guide <NUM> with respect to the width direction of the second plate <NUM> is <NUM>° ~ <NUM>°. The inclination angle θ is an angle of the sloped surface with respect to a virtual line α which is parallel to the width direction of the second plate <NUM> in a cross section (cross section shown in <FIG>) in which the second plate <NUM> is cut in the width direction, perpendicular to the lower end of the sloped surface. When, as in the present embodiment, the sloped surface includes the first sloped surface <NUM> and the second sloped surface <NUM>, at least the first sloped surface <NUM> having a steeper inclination is formed with the angle θ of <NUM>° ~ <NUM>°, and, desirably, both sloped surfaces are formed with the angle θ of <NUM>° ~ <NUM>°.

As the angle θ becomes larger, a component force in the lateral direction to the sidewall <NUM> in the slanted direction becomes stronger, and the centering can more reliably and easily performed against the frictional force. However, when the angle θ is too large, the slope height becomes high, resulting in firmer contact with the tube in the unlocked state, a higher frictional force, and, consequently, difficulty in the centering process. On the other hand, when the inclination angle θ of the sloped surface is less than <NUM>°, it becomes more difficult for the force, for sliding the second plate <NUM> toward the center in the width direction of the first plate <NUM> when the sloped surface contacts the sidewall <NUM>, to act, and, as a consequence, the centering process of the second plate <NUM> cannot be performed to a sufficient degree.

In the centering guide <NUM>, the inclination angle θ of at least the first sloped surface <NUM> (hereinafter referred to as an "inclination angle θ1") is desirably <NUM>° or greater, and is more desirably <NUM>° or greater, from the viewpoint of improving the centering function. An upper limit of the inclination angle θ1 is <NUM>°, or less than or equal to <NUM>°, from the viewpoint of a molding characteristic of the clamp <NUM>, prevention of interference with the medical tube <NUM>, or the like. Examples of a desirable range of the inclination angle θ1 include <NUM>° ~ <NUM>°, <NUM>° ~ <NUM>°, and <NUM>° ~ <NUM>°. Desirably, an inclined surface having the inclination angle θ1 in the above-described range is formed at least partially on the first sloped surface <NUM>, and, in this case, the centering process of the second plate <NUM> can be made smoother.

On the other hand, the inclination angle θ of the second sloped surface <NUM> (hereinafter, referred to as an "inclination angle θ2") is smaller than the inclination angle θ1 of the first sloped surface <NUM>, and may be, for example, <NUM>° or greater and less than <NUM>°, or <NUM>° or greater and less than <NUM>°. When the centering guide is formed from one sloped surface, the inclination angle θ of the sloped surface is desirably <NUM>° or greater, and is more desirably <NUM>° or greater, similar to the first sloped surface <NUM>.

In the present embodiment, the first sloped surface <NUM> and the second sloped surface <NUM> are both flat surfaces without unevenness. In addition, the second sloped surface <NUM> is formed at a side nearer to the tip of the second plate <NUM> than the first sloped surface <NUM>. When two sloped surfaces having different inclination angles θ are formed as in the present embodiment, the sloped surface with the smaller inclination angle θ is formed at a side nearer to the tip of the first plate <NUM> than the sloped surface with the larger inclination angle θ. It is sufficient that the first sloped surface <NUM> can contact a portion of the sidewall <NUM>, and the surface is formed to be longer in the lateral direction than in the vertical direction. With such a configuration, sink marks which are formed during the molding due to an increase in the thickness of the second plate <NUM> can be reduced, along with the adverse influences of the sloped surface on the tube during the clamping.

The centering guide <NUM> is formed at a position to contact the sidewall <NUM> when the second plate <NUM> is pushed in a slanted direction and the spacing X is reduced by <NUM>% ~ <NUM>%, desirably, <NUM>% ~ <NUM>%. If the centering guide <NUM> contacts the sidewall <NUM> at a stage of a small reduction percentage of the spacing X, the centering process would be performed when the frictional force is relatively small. Thus, with the above-described structure, a situation in which the centering does not function due to the frictional force can be reduced. A length in the vertical direction of the first sloped surface <NUM> is, for example, <NUM>% ~ <NUM>% of the length in the vertical direction of the sidewall <NUM>. As the length in the vertical direction of the first sloped surface <NUM> becomes shorter, the contact area with the sidewall <NUM> becomes smaller, resulting in a smaller frictional resistance during the centering, and ease of manipulation. However, when the length in the vertical direction is too short, there is a possibility that the sloped surface does not contact the sidewall <NUM> when the connecting portion <NUM> is significantly distorted. Therefore, an appropriate relationship is desirable.

The centering guide <NUM> is desirably formed in such a manner that the centering guide <NUM> contacts the sidewall <NUM> before the second plate <NUM> is pushed in the slanted direction and the spacing X is reduced by <NUM>%. In this case, the centering of the second plate <NUM> can be realized quickly, and the maneuverability is further improved. In the side view of the clamp <NUM> in the unlocked state, the spacing between the lower end of the first sloped surface <NUM> and the upper end of the sidewall <NUM> is, for example, <NUM>% ~ <NUM>%, and is desirably <NUM> % ~ <NUM>%, of the spacing X between the first protrusion <NUM> and the second protrusion <NUM>.

Because the first sloped surface <NUM> protrudes more toward the first plate <NUM> than the second sloped surface <NUM> does, when the inappropriate locking manipulation is performed such as pushing the second plate <NUM> in the slanted direction, the first sloped surface <NUM> first contacts the sidewall <NUM>. On the other hand, when strong pressure is applied to the second plate <NUM> toward the connecting portion <NUM>, the second sloped surface <NUM> which is formed on the side nearer to the tip of the second plate <NUM> than the first sloped surface <NUM> contacts the sidewall <NUM>, and, thus, the second plate <NUM> is centered using the second sloped surface <NUM>.

<FIG> is a diagram showing a relationship between the inclination angle θ1 of the first sloped surface <NUM> and the force necessary for locking the clamp <NUM> (pressurization force of the second plate <NUM>). The pressurization force was measured using a precision universal testing machine autograph ("AG Xplus" manufactured by Shimadzu Corporation). In this experiment, for the inclination angles θ1 of <NUM>° and <NUM>°, pressurization forces were measured <NUM> times for each inclination angle, and average values were determined. For the clamp having θ1 of <NUM>°, the shape of the tip portion of the second protrusion <NUM> which contacts the medical tube <NUM> was set to a semispherical shape in side view, similar to the first protrusion <NUM>. For the medical tube <NUM>, a flexible tube having a diameter similar to the spacing X was used.

The configuration labeled "Normal" in <FIG> indicates a case where the clamp is locked by an appropriate manipulation to push the second plate <NUM> straight toward the first plate <NUM>. The configuration labeled "Abnormal" in <FIG> indicates a case where the second plate <NUM> is pushed in the slanted direction so that a region of the first sloped surface <NUM> near the lower end contacts the sidewall <NUM>, and the clamp is locked after the centering of the second plate <NUM>.

As shown in <FIG>, when the appropriate locking manipulation is performed, because the first sloped surface <NUM> of the second plate <NUM> does not contact the sidewall <NUM> of the first plate <NUM>, there is no significant difference in the pressurization force between different inclination angles θ1. In the clamp having θ of <NUM>°, the pressurization force is smaller by about <NUM>% than the clamp having θ1 of <NUM>°, but this difference may be considered to be caused by the shape of the tip end portion of the second protrusion <NUM>. In other words, by forming the tip end portion of the second protrusion <NUM> in the approximate V shape in side view, it becomes possible to reduce the force necessary for locking, and to improve maneuverability.

On the other hand, when the inappropriate locking manipulation in which the second plate <NUM> is pushed in the slanted direction is performed, there is a significant difference in the pressurization force depending on the inclination angle θ1. As shown in <FIG>, in the clamp having θ of <NUM>°, the pressurization force is significantly reduced in comparison to the clamp with θ1 of <NUM>°. In other words, in the clamp having θ of <NUM>°, in comparison to the clamp having θ1 of <NUM>°, when the inappropriate manipulation is performed, it is easier to center the second plate <NUM> and to secure the normal locked state.

When the inclination angle θ1 of the first sloped surface <NUM> is less than <NUM>°, the pressurization force necessary for locking when the inappropriate locking manipulation is performed is significantly increased, and the centering of the second plate <NUM> is difficult. When the inclination angle θ1 is <NUM>° or greater, the second plate <NUM>° can be centered, and, when the inclination angle θ1 is <NUM>° or greater, in particular, <NUM>° or greater, the pressurization force necessary for the locking is specifically reduced, and the maneuverability is significantly improved.

<FIG> are diagrams showing alternative configurations of the first sloped surface <NUM> of the centering guide <NUM>. A first sloped surface 33X exemplified in <FIG> is formed to be curved in a manner to be convex down, so that a distance between the sloped surface and the sidewall is reduced, and the centering is performed at an earlier stage when the plate is pushed in the slanted direction. A first sloped surface 33Y exemplified in <FIG> differs from the first sloped surface <NUM> formed in a flat shape in that the sloped surface 33Y is curved in a manner to be convex down, and there is a point of change of an angle. With such a configuration, the component force in the width direction when the sloped surface contacts the sidewall can be increased and the length in the height direction of the sloped surface can be reduced. Each of the first sloped surfaces 33X and 33Y is a convex surface protruding downward in relation to a virtual line β connecting an upper end P1 and a lower end P2 of the sloped surface in the cross section in which the second plate <NUM> is cut in the width direction, perpendicular to the lower end of the sloped surface. In this case, an angle between the virtual line α parallel to the width direction of the second plate <NUM> and the virtual line β is assumed to be the inclination angle θ1.

Alternatively, the sloped surface may be a curved or bent concave surface which is convex up. In this case also, the angle between the virtual line α and a virtual line β connecting the upper end P1 and the lower end P2 of the sloped surface is assumed to be the inclination angle θ. The sloped surface may be a concave surface, but desirably, the sloped surface is a flat surface or a convex surface. The first sloped surface 33Y exemplified in <FIG> is formed from two flat surfaces S1 and S2 having different inclination angles with respect to the virtual line α, and desirably, both of the flat surfaces S1 and S2 are inclined by an angle of <NUM>° or greater with respect to the virtual line α.

As described, with the clamp <NUM> having the above-described structure, even when inappropriate locking manipulation is performed, the second plate <NUM> can be centered at the normal position where the medical tube <NUM> can be reliably occluded, and the normal locked state can be easily secured. Therefore, with the clamp <NUM>, the medical tube <NUM> can be quickly and reliably occluded. In addition, even when the clamp <NUM> is equipped on a medical tube <NUM> having a large diameter, the centering of the second plate <NUM> can be easily performed.

In particular, by providing the centering guide <NUM> including the sloped surface having the inclination angle θ with respect to the width direction of the second plate <NUM> of <NUM>° ~ <NUM>°, and more desirably, <NUM>° ~ <NUM>°, the force necessary for the centering of the second plate <NUM> is significantly reduced, and a smoother centering is enabled.

The embodiment described above can be suitably changed in design within a range not adversely affecting the objective of the present invention. For example, in the embodiment described above, a clamp <NUM> formed from a resin molded structure which is integrally molded is exemplified, but alternatively, the clamp may be produced by assembling a plurality of components. In addition, in the embodiment described above, the sidewall <NUM> is formed on the first plate <NUM> and the sloped surface (the first sloped surface <NUM> and the second sloped surface <NUM>) is formed on the second plate <NUM>, but alternatively, the sloped surface may be formed on the first plate and the sidewall may be formed on the second plate.

Claim 1:
A medical tube clamp (<NUM>) which presses and occludes a flexible medical tube (<NUM>), the medical tube clamp (<NUM>) comprising:
a first plate (<NUM>) on which a first protrusion (<NUM>) is formed;
a second plate (<NUM>) placed opposing the first plate (<NUM>), and on which a second protrusion (<NUM>) which presses the medical tube (<NUM>) along with the first protrusion (<NUM>) is formed;
a connecting portion (<NUM>) that connects one end of the first plate (<NUM>) in a length direction and one end of the second plate (<NUM>) in a length direction, and that is elastically deformable so as to allow the first plate (<NUM>) and the second plate (<NUM>) to be closer to each other; and
a locking unit (<NUM>) that is formed extending from the first plate (<NUM>) toward the second plate (<NUM>), that locks an other end of the second plate (<NUM>) in the length direction, and that maintains an occluded state of the medical tube (<NUM>), wherein
a pair of sidewalls (<NUM>) which extend in a standing manner are formed on both ends in a width direction on the first plate (<NUM>),
a biting-prevention piece (<NUM>) is formed extending from the other end of the second plate in the length direction (<NUM>) to the second protrusion (<NUM>) along the length direction on a center in a width direction of the second plate (<NUM>), the biting-prevention piece (<NUM>) protruding toward the first plate (<NUM>),
a sloped surface (<NUM>) is formed on the second plate (<NUM>), the sloped surface (<NUM>) being inclined toward the first plate (<NUM>) from both ends in the width direction toward the center in the width direction of the second plate (<NUM>), and
an inclination angle θ of the sloped surface (<NUM>) with respect to the width direction of the second plate (<NUM>) is <NUM>° ~ <NUM>°, and characterized in that the sloped surface (<NUM>) protrudes beyond the biting-prevention piece (<NUM>) toward the first plate (<NUM>) at the center in the width direction of the second plate (<NUM>).