Patent Description:
The present invention relates to a syringe gasket having an element therein and a syringe including the syringe gasket.

Conventionally, there is known a gasket (piston) configured to slide in a cylindrical barrel (cartridge body) while maintaining liquid-tightness so as to prevent leakage of a medical solution in the barrel (see Patent Literature <NUM>). The gasket has elasticity in order to ensure the liquid-tightness by being in close contact with an inner peripheral surface of the barrel. Also, the gasket has an element (microchip) therein that stores data on at least one of the date and time of the production (date and time when the barrel is filled with a medical solution). It is possible to check at least one of the date and time date and time when the barrel is filled with a medical solution by reading the data of the element, thereby facilitating, for example, quality control of the medical solution filled in the barrel.

There is a case where, when the gasket is inserted into the barrel, the elastic deformation of a portion of the gasket that comes into close contact with the barrel is hardly made due to, for example, the arrangement position of an element such as a microchip, thereby increasing the resistance (sliding resistance) at the time of sliding the gasket in the barrel.

It is therefore an object of the present invention to provide a syringe gasket capable of suppressing a sliding resistance with a barrel even it has an element therein, and a syringe including the syringe gasket.

A syringe gasket according to the present invention is a syringe gasket configured to be connected to a distal end of a plunger rod, while being disposed in a cylindrical barrel, the syringe gasket including: a first member having a large diameter part and a small diameter part, the large diameter part being in close contact with an entire area of an inner peripheral surface of the barrel in a circumferential direction when the syringe gasket is inserted into the barrel, the small diameter part being located adjacent to the large diameter part and having a smaller diameter than the large diameter part; a second member configured to be connected to the first member from a side of the small diameter part in an axial direction that is a direction in which the large diameter part and the small diameter part are aligned with each other; and an element disposed between the first member and the second member, the first member and the second member having elasticity, the first member having a recess that is recessed from an end surface on the side of the second member toward the large diameter part in the axial direction, the recess having a bottom that is recessed to reach a boundary position between the large diameter part and the small diameter part in the axial direction or a certain position on the side of the second member relative to the boundary position, the second member having a projection that projects toward the first member and is configured to fit into the recess with the element disposed between the recess and the projection, and having a screw hole extending from an end surface of the second member on an opposite side to the first member toward the first member to reach an inside of the projection in the axial direction to allow a screw part provided at the distal end of the plunger rod to be screwed thereinto.

The syringe gasket can be configured such that the small diameter part has an annular projection that projects radially outward at a position with a distance from the large diameter part in the axial direction, while extending through the entire area in the circumferential direction, the annular projection is in close contact with an entire area of the inner peripheral surface of the barrel in the circumferential direction when the syringe gasket is inserted into the barrel, the element is disposed between the large diameter part and the annular projection in the axial direction, and the screw hole extends at least to a position of the annular projection in the axial direction.

Further, a syringe according to the present invention includes: a syringe body having a cylindrical barrel: the syringe gasket of any one of the above being disposed in the barrel; and a plunger rod extending along a central axis of the barrel and having a screw part that is provided in a distal end of the plunger rod and configured to be threaded into the screw hole of the syringe gasket.

A syringe gasket according to this embodiment is a syringe gasket configured to be connected to a distal end of a plunger rod, while being disposed in a cylindrical barrel, the syringe gasket including: a first member having a large diameter part and a small diameter part, the large diameter part being in close contact with an entire area of an inner peripheral surface of the barrel in a circumferential direction when the syringe gasket is inserted into the barrel, the small diameter part being located adjacent to the large diameter part and having a smaller diameter than the large diameter part; a second member configured to be connected to the first member from a side of the small diameter part in an axial direction that is a direction in which the large diameter part and the small diameter part are aligned with each other; and an element disposed between the first member and the second member, the first member and the second member having elasticity, the first member having a recess that is recessed from an end surface on the side of the second member toward the large diameter part in the axial direction, the recess having a bottom that is recessed to reach a boundary position between the large diameter part and the small diameter part in the axial direction or a certain position on the side of the second member relative to the boundary position, the second member having a projection that projects toward the first member and is configured to fit into the recess with the element disposed between the recess and the projection, and having a screw hole extending from an end surface of the second member on an opposite side to the first member toward the first member to reach an inside of the projection in the axial direction to allow a screw part provided at the distal end of the plunger rod to be screwed thereinto.

Accordingly, the element is disposed at a position displaced in the axial direction (i.e., between the recess of the first member and the projection of the second member) relative to the large diameter part that is brought into close contact with the inner peripheral surface of the barrel by the elasticity when the syringe gasket is disposed within the barrel. Thus, it is possible to ensure ease of elastic deformation of the large diameter part in a radial direction. Also, the screw hole extending to the inside of the projection is provided in the second member to minimize the thickness in the radial direction of a part in which two members overlap with each other in the radial direction in the syringe gasket (i.e., a portion with the projection of the second member fitting into the recess of the first member). Thus, it is possible to ensure ease of elastic deformation of this portion. These configurations can suppress sliding resistance when the syringe gasket slides in the barrel.

According to this configuration, the syringe gasket is in close contact with the inner peripheral surface of the barrel at two positions (i.e., the position of the large diameter part and the position of the annular projection) when the syringe gasket is inserted into the barrel. Thus, the liquid-tightness between the barrel and the gasket can be sufficiently ensured. Moreover, the screw hole extends at least to the position at which the annular projection is formed in the syringe gasket to thereby suppress the thickness in the radial direction of this portion (that is, in order to ensure ease of elastic deformation of this portion). Thus, it is possible to effectively suppress the increase in the sliding resistance due to the increase in parts in close contact with the inner peripheral surface of the barrel.

Further, a syringe according to this embodiment includes: a syringe body having a cylindrical barrel: the syringe gasket of any one of the above being disposed in the barrel; and a plunger rod extending along a central axis of the barrel and having a screw part that is provided in a distal end of the plunger rod and configured to be threaded into the screw hole of the syringe gasket.

According to this configuration, the element is disposed at a position displaced in the axial direction (i.e., between the recess of the first member and the projection of the second member) relative to the large diameter part that is in close contact with the inner peripheral surface of the barrel due to the elasticity. Thereby, it is possible to ensure ease of elastic deformation (flexibility) of the large diameter part in a radial direction. Also, the screw hole extending to the inside of the projection is provided in the second member to minimize the thickness in the radial direction of a part in which the two members overlap with each other in the radial direction in the syringe gasket (i.e., a portion with the projection of the second member fitting into the recess of the first member). Thereby, it is possible to ensure ease of elastic deformation of this portion. These configurations can suppress the sliding resistance when the syringe gasket slides in the barrel.

As described above, according to this embodiment, it is possible to provide a syringe gasket capable of suppressing sliding resistance even it has an element therein, and a syringe including the syringe gasket.

Hereinafter, an embodiment of the present invention will be described with reference to <FIG>.

As shown in <FIG> and <FIG>, the syringe according to this embodiment includes a syringe body <NUM> having a cylindrical barrel <NUM>, a gasket (syringe gasket) <NUM> to be inserted into the barrel <NUM>, and a plunger rod <NUM> extending in a direction of a central axis C of the barrel <NUM> and having a distal end to which a gasket <NUM> is connected.

The syringe body <NUM> includes a barrel (trunk) <NUM>, a discharge part <NUM> extending from one end (i.e., distal end) in the direction of the central axis C of the barrel <NUM>, and a flange <NUM> disposed at the other end (i.e., proximal end) in the direction of the central axis C of the barrel <NUM>. The syringe body <NUM> is rigid and formed by, for example, glass or a hard resin (e.g., plastic) through which the inside is visible. Note that, hereinafter, one side (i.e., lower side in <FIG>) in the direction of the central axis C will be referred to as a distal side, and the other side (i. e, upper side in <FIG>) in the central axis C direction will be referred to as a proximal side.

The cylindrical barrel <NUM> has an inner peripheral surface <NUM> having an inner diameter (diameter) constant at every position in the direction of the central axis C. The distal end of the barrel <NUM> except for the discharge part <NUM> is closed, and the proximal end of the barrel <NUM> is open (see <FIG>). The syringe body <NUM> of this embodiment has a nominal volume of <NUM>, and an inner diameter ϕ1 of the barrel <NUM> is, for example, approximately <NUM> to <NUM>.

The discharge part <NUM> projects in a cylindrical shape from the distal end of the barrel <NUM> and is a part with which a hub of a needle tube or a connector can be fitted (mounted).

The flange <NUM> is a plate-shaped part to which a fingers are hooked when the plunger rod <NUM> is relatively moved to the syringe body <NUM> (i.e., barrel <NUM>) in the direction of the central axis C, and extends from the barre <NUM> along a surface (i.e., virtual surface) orthogonal to the central axis C.

The plunger rod <NUM> includes a rod body <NUM> extending in the direction of the central axis C, and a male screw part (screw part) <NUM> extending from the distal end of the rod body <NUM> in the direction of the central axis C and having a male screw on an outer peripheral surface. The plunger rod <NUM> also includes a flange <NUM> disposed at the proximal end of the rod body <NUM> and extending along a surface (i.e., virtual surface) orthogonal to the central axis C. The plunger rod <NUM> is rigid and formed by, for example, a hard resin (e.g., plastic).

The rod body <NUM> includes a plate-shaped pressing part <NUM> located at the distal end and extends in a direction orthogonal to the central axis C. The pressing part <NUM> is a part configured to press the gasket <NUM> in the barrel <NUM>. The pressing part <NUM> of this embodiment has a disc shape with a diameter (outer diameter) slightly larger than a part of the gasket <NUM> which abuts the pressing part <NUM> and slightly smaller than the inner diameter ϕ1 of the barrel <NUM>.

The male screw part <NUM> extends from a center of the disc-shaped pressing part <NUM> in the direction of the central axis C.

The gasket <NUM> is a column-shaped member capable of sliding in the barrel <NUM> while maintaining the liquid-tightness between the gasket <NUM> and the inner peripheral surface <NUM> of the barrel <NUM>. The gasket <NUM> of this embodiment is composed of a plurality of members. Specifically, as shown in <FIG>, the gasket <NUM> includes a first member <NUM>, a second member <NUM> to be connected to the first member <NUM> from the proximal side of the first member <NUM>, and an RF tag (element) <NUM> disposed between the first member <NUM> and the second member <NUM>. The first member <NUM> and the second member <NUM> are aligned with each other in the direction of the central axis C and have elasticity.

The first member <NUM> and the second member <NUM> each are made of an elastic material and typically, made of rubber or a thermoplastic elastomer. More specifically, the first member <NUM> and the second member <NUM> can be made of, for example, butyl rubber, isoprene rubber, butadiene rubber, halogenated butyl rubber, ethylene propylene terpolymer, and silicone rubber, but are not limited to these examples. Also, the first member <NUM> and the second member <NUM> can be made of the same material or can be made of different materials.

The first member <NUM> includes a large diameter part <NUM> that is in close contact with an entire area of the inner peripheral surface <NUM> of the barrel <NUM> in a circumferential direction when the gasket <NUM> is inserted into the barrel <NUM>, and a small diameter part <NUM> that is located adjacent to the large diameter part <NUM> in the direction of the central axis C and has a smaller diameter (outer diameter) than the large diameter part <NUM>. The first member <NUM> of this embodiment is made of butyl rubber.

The large diameter part <NUM> is a column-shaped part having a center on the central axis C and has a surface <NUM> that faces the distal side to serve as a distal end surface of the gasket <NUM>. In the large diameter part <NUM> of this embodiment, the distal end surface <NUM> has a conical shape, and a peripheral surface <NUM> has a cylindrical surface shape. An outer diameter ϕ2 of the large diameter part <NUM> is larger than the inner diameter ϕ1 of the barrel <NUM> (see <FIG>). Thus, when the gasket <NUM> is inserted into the barrel <NUM>, the large diameter part <NUM> as a whole is elastically deformed (i.e., elastically compressed) radially inward (i.e., toward the central axis C), thereby causing the peripheral surface <NUM> of the large diameter part <NUM> to come into close contact with the inner peripheral surface <NUM> of the barrel <NUM>.

The outer diameter ϕ2 of the large diameter part <NUM> of this embodiment is, for example, approximately <NUM> to <NUM>. The size (thickness) T1 of the large diameter part <NUM> in the direction of the central axis C is, for example, approximately <NUM> to <NUM>.

The small diameter part <NUM> is a part extending from the large diameter part <NUM> to the proximal side and having a columnar-shaped appearance having a center on the central axis C. An outer diameter (diameter) ϕ3 of the small diameter part <NUM> is smaller than an outer diameter (diameter) ϕ2 of the large diameter part <NUM>. The small diameter part <NUM> has a recess <NUM> recessed from an end surface <NUM> on the proximal side (that is, on the side of the second member <NUM>) toward the distal side, that is, toward the large diameter part <NUM> in the direction of the central axis C. The small diameter part <NUM> also has a first annular projection (annular-shaped projection) <NUM> that projects radially outward at a position with a distance from the large diameter part <NUM> on the proximal side in the direction of the central axis C, and extends through an entire area in the circumferential direction.

In the small diameter part <NUM> of this embodiment, the outer diameter ϕ3 is set to be constant at every position in the direction of the central axis C except for the position at which the first annular projection <NUM> is provided, and is, for example, approximately <NUM> to <NUM>. The outer diameter ϕ3 is set to have such a size as to cause no contact with the inner peripheral surface <NUM> of the barrel <NUM> even in a state where the gasket <NUM> is inserted into the barrel <NUM>.

The recess <NUM> is recessed from the end surface <NUM> of the small diameter part <NUM> to a boundary position B between the large diameter part <NUM> and the small diameter part <NUM> or a certain position closer to the proximal side than the boundary position B. Specifically, the recess <NUM> is recessed to a certain position on the proximal side of a virtual surface K including the boundary position between the large diameter part <NUM> and the small diameter part <NUM> on the surface of the gasket <NUM> (in the example shown in <FIG>, a virtual surface extending in the direction orthogonal to the central axis C and including the boundary position on the surface of the gasket <NUM>). That is, the boundary position B in this embodiment means not only the boundary position between the large diameter part <NUM> and the small diameter part <NUM> on the surface of the gasket <NUM> but also a position defined by the virtual surface K including the boundary position and extending in the direction orthogonal to the central axis C. The recess <NUM> of this embodiment is recessed from the end surface <NUM> to the boundary position B and is a recess having a truncated cone-shape. Specifically, in the recess <NUM>, a bottom surface <NUM> is a circular surface extending in the direction orthogonal to the central axis C, and an inner peripheral surface (i.e., surface surrounding the central axis C) <NUM> connected to a peripheral edge of the bottom surface <NUM> has a tapered shape with an inner diameter gradually decreasing toward the bottom surface <NUM>.

A depth of the recess <NUM> of this embodiment, that is, a distance from the end surface <NUM> to the bottom surface <NUM> in the direction of the central axis C is approximately <NUM> to <NUM>. An angle α1 of the inner peripheral surface <NUM> relative to the central axis C is larger than <NUM>° (not vertical), preferably <NUM>° or more, more preferably <NUM>° or more. The angle α1 is limited by the outer diameter (ϕ3) of the small diameter part <NUM> and an outer diameter (ϕ8) of an RF tag <NUM> to be described later, and thus the limited angle is accordingly adopted. The larger the angle α1, the easier the arrangement of the RF tag <NUM> at the time of assembly (i.e., at the time of production) of the gasket <NUM>. Further, joining of the first member <NUM> to the second member <NUM> can be easily performed and become strong.

The first annular projection <NUM> is in close contact with an entire area of the inner peripheral surface <NUM> of the barrel <NUM> in the circumferential direction when the gasket <NUM> is inserted into the barrel <NUM>. In the small diameter part <NUM>, an outer diameter ϕ4 of a part in which the first annular projection <NUM> is located is larger than the outer diameter ϕ3 of the other part in the direction of the central axis C and smaller than the outer diameter ϕ2 of the large diameter part <NUM>. The outer diameter ϕ4 of a part in which the first annular projection <NUM> is provided in the small diameter part <NUM> of this embodiment is, for example, approximately <NUM> to <NUM>.

The second member <NUM> includes a columnar-shaped base part <NUM>, and a projection <NUM> that projects from the base part <NUM> toward the distal side (i.e., toward the first member <NUM>) and fits into the recess <NUM> with the RF tag <NUM> located between the projection <NUM> and the recess <NUM> of the first member <NUM>. The second member <NUM> of this embodiment is made of butyl rubber.

The base part <NUM> includes: a second annular projection <NUM> that projects radially outward at a position with a distance from the first annular projection <NUM> of the first member <NUM> on the proximal side in the direction of the central axis C, and extends through an entire area in the circumferential direction; and an annular recess <NUM> that is provided at a position adjacent to the second annular projection <NUM> on the proximal side in the direction of the central axis C. The annular recess <NUM> extends through an entire area in the circumferential direction. In the base part <NUM> of this embodiment, a part on the proximal side of the annular recess <NUM> has a tapered shape with the outer diameter gradually decreasing toward the proximal side. The part on the proximal side of the annular recess <NUM> is preferably smaller than the inner diameter ϕ1 of the barrel <NUM>.

Also, the base part <NUM> includes a screw hole <NUM> extending from an end surface on the proximal side (i.e., end surface opposite to the first member <NUM>) <NUM> toward the distal side, that is, toward the first member <NUM>. The end surface <NUM> on the proximal side of the base part <NUM> of this embodiment serves as an end surface on the proximal side of the gasket <NUM>.

An outer diameter ϕ5 of the base part <NUM> is the same or substantially the same as the outer diameter ϕ3 of the small diameter part <NUM>, and is, for example, approximately <NUM> to <NUM>. A size (thickness) T3 of the base part <NUM> in the direction of the central axis C is, for example, approximately <NUM> to <NUM>.

The second annular projection <NUM> is in close contact with an entire area of the inner peripheral surface <NUM> of the barrel <NUM> in the circumferential direction when the gasket <NUM> is inserted into the barrel <NUM>. In the base part <NUM>, an outer diameter ϕ6 of a part in which the second annular projection <NUM> is provided is larger than the outer diameter ϕ5 of the other part in the direction of the central axis C and smaller than the outer diameter ϕ2 of the large diameter part <NUM> of the first member <NUM>. In the base part <NUM> of this embodiment, the outer diameter ϕ6 of a part in which the second annular projection <NUM> is provided is the same or substantially the same as the outer diameter ϕ4 of the part in which the first annular projection <NUM> of the first member <NUM> is provided. In the base part <NUM> of this embodiment, the outer diameter ϕ6 of the part in which the second annular projection <NUM> is provided is, for example, approximately <NUM> to <NUM>.

The screw hole <NUM> is a hole, into which the male screw part <NUM> of the plunger rod <NUM> is screwed, and has a female screw on its inner peripheral surface surrounding the central axis C. The screw hole <NUM> extends to the inside of the projection <NUM> of the second member <NUM> in the direction of the central axis C. The screw hole <NUM> of this embodiment extends from the end surface <NUM> of the base part <NUM> to the position of the first annular projection <NUM> of the first member <NUM> in the direction of the central axis C. More specifically, the screw hole <NUM> extends from the end surface <NUM> toward the distal side so as to have the position of a bottom surface <NUM> of the screw hole <NUM> coinciding with an end edge position on the distal side of the first annular projection <NUM> in the direction of the central axis C. A hole diameter of the screw hole <NUM> is set so that a gap is formed between the inner peripheral surface of the screw hole <NUM> and the male screw part <NUM> of the plunger rod <NUM> (see <FIG>).

The projection <NUM> has a distal end recess <NUM> located at the distal end into which the RF tag <NUM> is fitted. The projection <NUM> has a shape corresponding to the recess <NUM> of the first member <NUM>. Specifically, the projection <NUM> has a truncated cone shape with its outer diameter gradually decreasing toward the distal side, that is, has a tapered outer peripheral surface <NUM>, and has a distal end surface <NUM> having the distal end recess <NUM> recessed toward the proximal side. The distal end surface <NUM> is a circular-shaped surface extending in the direction orthogonal to the central axis C and has the same diameter as the bottom surface <NUM> of the recess <NUM> of the first member <NUM>. The shape of the projection <NUM> of this embodiment, that is, the shape of each of the distal end surface <NUM>, the distal end recess <NUM>, the tapered outer peripheral surface <NUM>, etc. is formed in conformity with the shape of the recess <NUM> and the shape of the RF tag <NUM> respectively by a material (i.e., material for forming the second member <NUM>) that is solidified after being injected into the recess <NUM> of the first member <NUM> with the RF tag <NUM> disposed inside the recess <NUM>. Specific descriptions will be given below.

First, the first member <NUM> is formed. The aforementioned elements <NUM>, <NUM>, <NUM>, <NUM>, etc., are formed in the first member <NUM>. Note that the method for forming the first member <NUM> is not limited.

Next, as shown in <FIG>, the first member <NUM> is disposed on a cavity <NUM> that is formed in a lower mold <NUM> out of a pair of upper and lower molds <NUM> (i.e., lower mold <NUM> and upper mold <NUM>). The cavity <NUM> of the lower mold <NUM> is a columnar-shaped recess extending downward from an upper end surface 81a of the lower mold <NUM> and has a shape corresponding to the outer peripheral surface and the distal end surface <NUM>, of the gasket <NUM>. Here, the upper mold <NUM> out of the pair of molds <NUM> includes a projection <NUM> extending downward a lower end surface 82a. The projection <NUM> has a shape corresponding to the screw hole <NUM> of the gasket <NUM> (the second member <NUM>). In these lower mold <NUM> and upper mold <NUM>, when the lower mold <NUM> and the upper mold <NUM> are closed (overlapped with each other) to allow the projection <NUM> to be inserted along the center of the cavity <NUM>, a space S having a shape corresponding to the gasket <NUM> is formed between the lower mold <NUM> and the upper mold <NUM> (i.e., inside the pair of molds <NUM>).

The first member <NUM> disposed on the bottom of the cavity <NUM> is oriented such that the distal end surface <NUM> is located at the lower end of the first member <NUM> and the recess <NUM> is located at the upper end of the first member <NUM>. With the first member <NUM> held in this state, the RF tag <NUM> is disposed in the recess <NUM> in a state where a surface on one side (i.e., distal side surface) faces the bottom surface <NUM>.

Subsequently, a material for the second member <NUM> is injected into the cavity <NUM> (i.e., the space S defined in the inside of the pair of molds <NUM> except for an area in which the first member <NUM> is disposed), while the lower mold <NUM> and the upper mold <NUM> are closed. When the material is solidified by, for example, heating or vulcanization with the area S1 filled with the material, the second member <NUM> having a shape corresponding to the area S1 and joined to the first member <NUM> is formed, that is, the gasket <NUM> is formed.

When the material for the second member <NUM> is injected into the area S1 as described above, the inside of the recess <NUM> with the RF tag <NUM> disposed on the bottom surface <NUM> is filled with the material, and then the material is solidified. Thereby, the distal end recess <NUM> having a shape in conformity to the shape of the RF tag <NUM> is formed in the distal end surface <NUM> of the projection <NUM> of the second member <NUM>.

The projection amount of the projection <NUM> of this embodiment, that is, the distance from the distal end surface <NUM> of the base part <NUM> to the distal end surface <NUM> of the projection <NUM> in the direction of the central axis C is the same as the depth of the recess <NUM> of the first member <NUM>, and is approximately <NUM> to <NUM>. Also, an angle α2 of the outer peripheral surface <NUM> relative to the central axis C is the same as the angle of the inner peripheral surface <NUM> of the recess <NUM> relative to the central axis C, and is <NUM>° or more (not vertical), preferably <NUM>° or more, more preferably <NUM>° or more. The angle α2 is limited by the outer diameter (ϕ3) of the small diameter part <NUM> and the outer diameter (ϕ8) of the RF tag <NUM> to be described later, and thus the limited angle is accordingly adopted.

The distal end recess <NUM> is recessed to correspond to the shape of the RF tag <NUM>. The distal end recess <NUM> of this embodiment is recessed so that the distal end surface <NUM> is flush or substantially flush with the distal side surface <NUM> of the plate-shaped RF tag <NUM> with the RF tag <NUM> fitted in the distal end recess <NUM>. Specifically, the distal end recess <NUM> has a circular-shaped bottom surface <NUM> extending in the direction orthogonal to the central axis C and an inner peripheral surface <NUM> having an inner diameter ϕ7 that is constant at every position in the direction of the central axis C. A depth D1 of the distal end recess <NUM> of this embodiment (i. e, distance in the direction of the central axis C from the distal end surface <NUM> to the bottom surface <NUM>) is approximately <NUM> to <NUM>.

In the first member <NUM> and the second member <NUM> configured as above, with the RF tag <NUM> being disposed in the area surrounded by the bottom surface <NUM> of the recess <NUM> of the first member <NUM> and the distal end recess <NUM> provided in the projection <NUM> of the second member <NUM>, the bottom surface <NUM> of the recess <NUM> in the first member <NUM> and the distal end surface <NUM> of the projection <NUM> in the second member <NUM> are adhered (joined) to each other; the inner peripheral surface <NUM> of the recess <NUM> in the first member <NUM> and the outer peripheral surface <NUM> of the projection <NUM> in the second member <NUM> are adhered (joined) to each other; and the end surface <NUM> on the proximal side in the first member <NUM> and the distal end surface <NUM> of the base part <NUM> in the second member <NUM> are adhered (joined) to each other.

Further, in the gasket <NUM>, the depth of the recess <NUM> of the first member <NUM> (that is, the projection amount of the projection <NUM> of the second member <NUM>) and the depth D1 of the distal end recess <NUM> in the projection <NUM> of the second member <NUM> are set so that the RF tag <NUM> is located between the large diameter part <NUM> and the first annular projection <NUM> of the first member <NUM> in the direction of the central axis C (see <FIG>).

The RF tag <NUM> is capable of storing (recording) information about the liquid (e.g., medical solution) to be, for example, sealed in the syringe <NUM>, information about the date and time of sealing, and the production record, and information of the sealed medical solution, and allows the aforementioned information to be read out and written in by, for example, a reader-writer from the outside of the syringe with the liquid sealed therein. This RF tag has a plate shape extending in the direction orthogonal to the central axis C, and the RF tag <NUM> of this embodiment has a disc shape. The RF tag <NUM> is harder than the first member <NUM> and the second member <NUM>. That is, the hardness of the RF tag <NUM> is higher than the first member <NUM> and the second member <NUM>.

In the RF tag <NUM>, the outer diameter ϕ8 is preferably <NUM>% or more of the diameter of the bottom surface <NUM> of the recess <NUM> in the first member <NUM>. Thereby, displacement (movement) of the RF tag <NUM> at the time of producing the gasket <NUM> can be suppressed.

Also in terms of the sliding resistance (i.e., in terms of preventing the degradation of slidability), it is preferable to select at least one of the configurations including: the configuration in which the outer diameter ϕ8 of the RF tag <NUM> is <NUM>% or less of the outer diameter ϕ2 of the large diameter part <NUM> of the first member <NUM>; the configuration in which the outer diameter ϕ8 of the RF tag <NUM> is <NUM>% or less of the outer diameter (i.e., outer diameter of the small diameter part <NUM>) ϕ3 at the part in which the RF tag <NUM> of the gasket <NUM> is disposed in the direction of the central axis C; and the configuration in which the outer diameter ϕ8 of the RF tag <NUM> is <NUM>% or less of the inner diameter ϕ1 of the barrel <NUM>.

The outer diameter (diameter) ϕ8 of the RF tag <NUM> is, for example, approximately <NUM>, and the thickness T4 thereof is, for example, approximately <NUM>.

As shown in <FIG>, the gasket <NUM> with the RF tag <NUM> therein is disposed in the barrel <NUM>, and in this state, the male screw part <NUM> of the plunger rod <NUM> is screwed into the screw hole <NUM>, that is, the gasket <NUM> is connected to the distal end of the plunger rod <NUM>. At this time, the gasket <NUM> has a larger diameter than the inner diameter of the barrel <NUM> at the large diameter part <NUM>, the first annular projection <NUM>, and the second annular projection <NUM> (see <FIG>), and thus is held in a compressed state in the radial direction in the barrel <NUM>. The elastic force due to this compression brings the large diameter part <NUM> and the annular projections <NUM>, <NUM> into close contact with the entire area of the inner peripheral surface <NUM> of the barrel <NUM> in the circumferential direction, thereby ensuring the liquid-tightness of the syringe <NUM> between the barrel <NUM> and the gasket <NUM>.

Thus, it is possible to ensure ease of elastic deformation (i.e., flexibility) of the large diameter part <NUM> in the radial direction by the syringe <NUM> described above, in which the RF tag <NUM> is disposed at a position (i.e., between the recess <NUM> of the first member <NUM> and the projection <NUM> of the second member <NUM>) displaced in the direction of the central axis C relative to the large diameter part <NUM> of the gasket <NUM>, the large diameter part <NUM> being configured to be elastically deformed in the radial direction in the barrel <NUM> to come into close contact with the inner peripheral surface <NUM> of the barrel <NUM>. It is also possible to ensure ease of elastic deformation of the part in which two members overlap with each other in the gasket <NUM> in the radial direction (i.e., part in which the projection <NUM> of the second member <NUM> fits into the recess <NUM> of the first member <NUM>) by the configuration where the second member <NUM> is provided with the screw hole <NUM> extending in the direction of the central axis C to the inside of the projection <NUM>, which minimizes the thickness of the aforementioned part. These configurations can suppress the sliding resistance when the gasket <NUM> is made to slide in the barrel <NUM>. Further, it is possible to suppress the deformation of the RF tag <NUM> by the configuration where the RF tag <NUM> is disposed between the recess <NUM> of the first member <NUM> and the projection <NUM> of the second member <NUM>, which can reduce the pressure on the RF tag <NUM> in the radial direction when the gasket <NUM> is disposed in the barrel <NUM>.

Also, according to the syringe <NUM> of this embodiment, the small diameter part <NUM> of the gasket <NUM> includes the first annular projection <NUM> that projects radially outward at a position with a distance from the large diameter part <NUM> in the direction of the central axis C and extends through the entire area in the circumferential direction, and the first annular projection <NUM> is in close contact with the entire area of the inner peripheral surface <NUM> of the barrel <NUM> in the circumferential direction when the gasket <NUM> is inserted into the barrel <NUM>. Further, according to the gasket <NUM>, the RF tag <NUM> is disposed between the large diameter part <NUM> and the first annular projection <NUM> in the direction of the central axis C, and the screw hole <NUM> extends to the position of the first annular projection <NUM> in the direction of the central axis C. As described above, the gasket <NUM> in a state of being inserted in the barrel <NUM> is in close contact with the inner peripheral surface <NUM> of the barrel <NUM> at two positions with a distance from each other in the direction of the central axis C (i.e., the position of the large diameter part <NUM> and the position of the first annular projection <NUM>), and thus the liquid-tightness between the barrel <NUM> and the gasket <NUM> is more sufficiently ensured. Moreover, it is possible to effectively suppress increase in the sliding resistance due to the increase in parts in close contact with the inner peripheral surface <NUM> of the barrel <NUM> by the configuration where the screw hole <NUM> in the gasket <NUM> extends to the position at which the first annular projection <NUM> is formed to thereby suppress the thickness of this part (that is, the ease of elastic deformation of this part can be ensured).

In the syringe <NUM> of this embodiment, it is possible to further ensure the liquid-tightness between the barrel <NUM> and the gasket <NUM> by the configuration where the second annular projection <NUM> located at the position with a distance from the first annular projection <NUM> in the direction of the central axis C is also in close contact with the inner peripheral surface <NUM> of the barrel <NUM>. Also, it is possible to suppress the sliding resistance due to the increase in parts of the gasket <NUM> in close contact with the inner peripheral surface <NUM> of the barrel <NUM> by the configuration where the screw hole <NUM> is provided to extend in the direction of the central axis C to the position at which the second annular projection <NUM> is provided , and thus, the ease of elastic deformation in this part can be ensured in the same manner as the first annular projection <NUM>,.

Moreover, in the syringe <NUM> of this embodiment, it is possible to suppress Thus, the increase in the sliding resistance due to the increase in parts of the gasket <NUM> in close contact with the peripheral surface <NUM> of the barrel <NUM> by the configuration where a gap that is formed between the inner peripheral surface of the screw hole <NUM> and the male screw part <NUM> of the plunger rod <NUM>, which can ensure ease of deformation at the position at which the first annular projection <NUM> of the gasket <NUM> is provided.

The syringe gasket and the syringe including the syringe gasket of the present invention are not limited to the aforementioned embodiments. For example, a configuration of another embodiment can be added to a configuration of one embodiment, and a part of the configuration of one embodiment can be replaced with the configuration of the other embodiment. Further, a part of the configuration of one embodiment can be omitted.

In the gasket <NUM> of the above embodiment, the RF tag <NUM> is disposed inside the gasket <NUM>, but is not limited to this configuration. The member to be disposed inside the gasket <NUM> is not limited to the RF tag <NUM>, and any member can be employed as long as an member can allow information to be remotely read out and written in (that is, from the outside of the gasket <NUM> or from the outside of the syringe <NUM>). Also, the member disposed inside the gasket <NUM> can be an element capable of sensing, for example, temperature and pressure, and capable of remotely transmitting the results of the sensing.

The element (RF tag) <NUM> of the above embodiment has a higher hardness than the first member <NUM> and the second member <NUM> of the gasket <NUM>, but is not limited to this configuration. The hardness of the element <NUM> can be the same as or lower than the hardness of the first member <NUM> and the second member <NUM>. The element <NUM> of the above embodiment has a plate shape extending in the direction orthogonal to the central axis C, but is not limited to this shape. Any shape can be adopted as long as the element <NUM> can be disposed inside the gasket <NUM>.

The element (RF tag) <NUM> of the above embodiment is not adhered (joined) to either the first member <NUM> or the second member <NUM>, but is not limited to this configuration. For example, it can be configured such that the distal side surface 61of the element (RF tag) <NUM> is adhered to the first member <NUM> (specifically, the bottom surface <NUM> of the recess <NUM>) via an adhesive layer, and a proximal side surface <NUM> of the element (RF tag) <NUM> is adhered to the second member <NUM> (specifically, the bottom surface <NUM> of the distal end recess <NUM>) via an adhesive layer. In this case, the entire area or part of the area of each of the surfaces <NUM>, <NUM> can be adhered to the first member <NUM> or the second member <NUM> in the element (RF tag) <NUM>. Since both the surfaces <NUM>, <NUM> of the plate-shaped RF tag <NUM> are adhered to the first member <NUM> and the second member <NUM> in this manner, the variation of the sliding resistance in each syringe <NUM> (i.e., sliding resistance during the movement of the plunger rod <NUM> in the direction of the central axis C relative to the syringe body <NUM>) can be suppressed.

In addition to the RF tag (element) <NUM>, the gasket <NUM> of the above embodiment is composed of two members having elasticity (i.e., the first member <NUM> and the second member <NUM>) aligned in the direction of the central axis C, but is not limited to this configuration, and can be composed of three or more members having elasticity aligned with each other in the direction of the central axis C.

The distal end surface <NUM> of the gasket <NUM> of the above embodiment has a conical shape, but is not limited to this configuration. The distal end surface <NUM> can be a surface extending in the direction orthogonal to the central axis C.

In the gasket <NUM> of the above embodiment, the screw hole <NUM>, into which the male screw part <NUM> of the plunger rod <NUM> is screwed, extends in the direction of the central axis C from the proximal side surface <NUM> of the gasket <NUM> to the position of the first annular projection <NUM>, but is not limited to this configuration. The screw hole <NUM> can extend to a certain position on the distal side of the position of the first annular projection <NUM>, and can extend to a certain position on the proximal side of the position of the first annular projection <NUM>, in the direction of the central axis C.

In the gasket <NUM> of the above embodiment, the first member <NUM> and the second member <NUM> are made of the same material without limitation thereto. The first member <NUM> and the second member <NUM> can be made of different materials, respectively.

In the gasket <NUM> of the above embodiment, the outer diameter ϕ4 of the part in which the first annular projection <NUM> is provided and the outer diameter ϕ6 of the part in which the second annular projection <NUM> is provided are the same or substantially the same as each other without limitation thereto. One of the outer diameter ϕ4 and the outer diameter ϕ6 can be larger than the other one within a range not exceeding the outer diameter ϕ2 of the large diameter part <NUM>.

The nominal volume of the syringe body <NUM> of the above embodiment is <NUM>, but any volume can be adopted. The nominal volume can be, for example, from <NUM> to <NUM>. In this case, the barrel <NUM> is configured to have an inner diameter corresponding to each volume, and each of the diameters in the gasket <NUM> is also configured to have a size corresponding thereto.

The gasket <NUM> of the above embodiment is formed such that a second molding is made on the RF tag <NUM> disposed in the recess <NUM> (on the bottom surface <NUM>) of the first member <NUM> that is fitted into the cavity <NUM> of the mold <NUM> (lower mold <NUM>). Thereby, a product (gasket <NUM>) is molded. That is, the distal end recess <NUM> of the second member <NUM> is inevitably formed by the shape of the RF tag <NUM> at the time of the second molding (i.e., at the time of molding of the second member <NUM>) without limitation thereto. The configuration can be such that, for example, the projection <NUM> without a recess is molded at the time of molding of the second member <NUM>, and then the distal end recess <NUM> is molded, that is, the first member <NUM> and the second member <NUM> are separately molded and then connected to each other.

The configuration can be such that the first member <NUM> and the second member <NUM> are separately molded, and then the first member <NUM> and the second member <NUM> are joined to each other so as to locate the RF tag <NUM> between the recess <NUM> of the first member <NUM> and the projection <NUM> of the second member <NUM>.

Claim 1:
A syringe gasket (<NUM>) configured to be connected to a distal end of a plunger rod (<NUM>), while being disposed in a cylindrical barrel (<NUM>), the syringe gasket comprising:
a first member (<NUM>) having a large diameter part and a small diameter part, the large diameter part being in close contact with an entire area of an inner peripheral surface of the barrel in a circumferential direction when the syringe gasket is inserted into the barrel, the small diameter part being located adjacent to the large diameter part and having a smaller diameter than the large diameter part;
a second member (<NUM>) configured to be connected to the first member from a side of the small diameter part in an axial direction that is a direction in which the large diameter part and the small diameter part are aligned with each other; and
an element (<NUM>) disposed between the first member and the second member,
the first member and the second member having elasticity,
the first member having a recess (<NUM>) that is recessed from an end surface on a side of the second member toward the large diameter part in the axial direction,
the recess having a bottom that is recessed to reach a boundary position between the large diameter part and the small diameter part in the axial direction or a certain position on the side of the second member relative to the boundary position,
the second member having a projection (<NUM>) that projects toward the first member and is configured to fit into the recess with the element disposed between the recess and the projection, and having a screw hole (<NUM>) extending from an end surface of the second member on an opposite side to the first member toward the first member to reach an inside of the projection in the axial direction to allow a screw part (<NUM>) provided at the distal end of the plunger rod to be screwed thereinto.