Backstop device for injection equipment

Abstract

A backstop device for maintaining the distal end of a plunger rod within a syringe barrel comprises an upper plate defining a first opening, configured to receive a plunger rod having an elongated body with a joint that joins a first curved end face to a second curved end face. The backstop device also comprises a lower plate defining a second opening configured to receive a syringe barrel, and at least one connector extending between the upper and lower plates. The first opening has a different shape from the second opening. An infusion device usable with the backstop device comprises a plunger rod having an elongated body, with a joint that joins the first and second curved end faces, which together define the discontinuous arcuate outer circumference of the elongated body.

Description

[Technical Field]

[0001] The disclosed concept relates to a backstop device that can be used with an injection device, such that the backstop device maintains the distal end of the plunger rod, more specifically, the stopper at the distal end of the plunger rod, within the syringe barrel. [Background technology]

[0002] background A syringe is a medical delivery device configured to administer a drug or other liquid medication to a patient. Syringes may be sold pre-filled, with the drug already inside the syringe during manufacturing, or they may be sold empty, with the drug being filled by the end user from a vial or other source immediately before administering the drug through the syringe.

[0003] Figures 1, 2A, and 2B show various parts of the injection device 12, including a syringe barrel 14 with a backstop 10 and a plunger rod 16. An example of an injection device including a syringe barrel, plunger rod, and backstop is provided in Patent Document 1.

[0004] Referring again to Figures 1, 2A, and 2B, the infusion device 12 generally comprises a syringe barrel 14 configured to contain a drug inside, the syringe barrel 14 having a distal end 15 to which a puncture element 17 (e.g., a needle) is connected, and an open proximal end 19 to which a flange 22 is positioned.

[0005] The plunger rod 16 is located at the proximal end 19. As best shown in the cross-sectional view of Figure 2B, obtained in plane A shown in Figure 2A, the conventional plunger rod 16 includes a first planar portion 21 and a second planar portion 23 that intersects the first planar portion 21 in a central region 25. Generally, the plunger rod 16 has a cruciate cross-section when observed in plane A. The plunger rod 16 has a finger rest portion 18 at its proximal end and a stopper 20 at its distal end.

[0006] The backstop 10 is attached to the syringe barrel 14 and configured to work in cooperation with the plunger rod 16. A prior art backstop 10 includes a lower plate 30 and an upper plate 32. The plates 30 and 32 define a surrounding space 31 between them. The surrounding space 31 is further defined by side walls that extend substantially vertically between the lower plate 30 and the upper plate 32, and along the three sides of the lower plate 30 and the upper plate 32. The side walls of the three sides extend around most of the perimeter of the backstop 10, substantially enclosing the flange 22 of the syringe barrel 14. A front opening 44 is provided to allow insertion of the flange 22 into it.

[0007] Openings are provided within each plate 30, 32. The opening 34 in the lower plate 30 is configured and dimensioned to accommodate the circumferential surface of the syringe barrel 14 and to form a mating contact with the circumferential surface of the syringe barrel 14. The opening 34 in the lower plate 30 includes a portion formed in a relatively arc shape to coincide with the substantially cylindrical outer surface of the syringe barrel 14. More specifically, the opening 34 is defined by the curved edge of the lower plate 30. The leading opening of the opening 34 is defined by two radially spreading, substantially flat surfaces extending from the curved edge. The leading opening of the opening 34 is typically formed to accommodate the insertion of the syringe barrel 14 through which it passes.

[0008] The opening 46 in the upper plate 32 is configured and dimensioned to accommodate the insertion of the plunger rod 16 into it. The opening 46 in the upper plate 32 is formed in substantially the same shape as the opening 34 in the lower plate 30. In particular, the opening 46 in the upper plate 32 includes a portion formed in a relatively arc shape by a curved edge to match the shape of a circle 27 inscribed on the discontinuous arcuate outer circumference of the plunger rod 16, which is defined by the outer surfaces of intersecting flat portions 21, 23. The lead opening is defined by two radially spreading, substantially flat surfaces extending from the end of the curved edge. The lead opening of the opening 46 is typically formed in a shape to accommodate the insertion of the plunger rod 16 through it.

[0009] During use, the plunger rod 16 can be advanced toward the distal end 15 of the barrel 14 to discharge fluid such as medicine from there. The plunger rod 16 can also be retracted from the distal end 15 toward the proximal end 19 to aspirate or fill the syringe barrel 14 with fluid. The backstop 10 is configured to allow the plunger rod 16 to move in any direction and to prevent the plunger rod 16 from being removed from the barrel 14.

[0010] In medical settings, a large number of syringes are used each year. Therefore, it is desirable that syringes be manufactured as cost-effectively as possible. For this reason, the design of the plunger rod has been modified to reduce material usage and manufacturing time. Modifications to the plunger rod, therefore, allow for modifications to the associated backstop, and allow for modifications to the backstop to reduce material usage and manufacturing time. [Prior art documents] [Patent Documents]

[0011] [Patent Document 1] U.S. Patent No. 5,667,495 [Overview of the project]

Problems to be Solved by the Invention

[0012] An object of the present disclosure is to provide a backstop device that cooperates with an injection device including a plunger rod for solving the above-mentioned drawbacks.

Means for Solving the Problems

[0013] The backstop device is for maintaining the distal end of the plunger rod within the syringe barrel. The backstop device includes an upper plate defining a first opening configured to receive therein a plunger rod having an elongated body with a joint that joins a first curved end face to a second curved end face. The backstop device also includes a lower plate defining a second opening configured to receive therein the syringe barrel. The first opening has a shape different from the shape of the second opening. The backstop device further includes at least one connector extending between the upper plate and the lower plate.

[0014] Certain preferred but non-limiting aspects of the backstop device described above are the following, which are employed individually or in combination The first opening of the upper plate is defined by a first flat surface, a second flat surface, and a third flat surface, the first flat surface and the second flat surface are positioned adjacent to opposite ends of the third flat surface, and extend in a parallel or radially spreading manner from the third flat surface The maximum depth of the upper plate is smaller than the maximum depth of the lower plate The maximum width of the upper plate is smaller than the maximum width of the lower plate The second opening of the lower plate is at least partially defined by an arcuate surface, and the curvature of the arcuate surface corresponds to the curvature of the outer surface of the syringe barrel to be received therein The upper and lower surfaces of the upper plate extend substantially parallel to each other At least one connector of the backstop device extends along a portion of the first side of the upper plate and along a portion of the first side of the lower plate, the first side of the upper plate facing a second side of the upper plate, with a first opening opening in the second side so as to receive a plunger rod therein, and the first side of the lower plate facing a second side of the lower plate, with a second opening opening in the second side so as to receive a syringe barrel therein. The backstop device comprises two opposing connectors, each of which extends from a first side of the upper plate and a first side of the lower plate toward a second side of the upper plate and a second side of the lower plate, and / or The volume of the upper plate is smaller than the volume of the lower plate.

[0015] The injection device comprises a syringe barrel, a plunger rod, and the backstop device described above. The plunger rod has an elongated body extending along the central axis between its proximal and distal ends. The body has a joint that joins a first curved end face to a second curved end face. Each of the first curved end face, the second curved end face, and the joint extends between the proximal and distal ends, and together the first and second curved end faces define a discontinuous arcuate outer circumference of the elongated body.

[0016] Certain preferred but non-limiting embodiments of the injection device described above are, individually or in combination, the following: The distance between the first flat surface and the second flat surface of the first opening in the upper plate is smaller than the diameter of the distal end of the plunger rod. The lower plate is positioned such that, when the backstop device is coupled to the syringe barrel, the lower surface of the upper plate and the upper surface of the lower plate contact the upper and lower surfaces of the syringe barrel flange, respectively.

[0017] The figures presented herein are not actual diagrams of any particular component, apparatus, or system, but are merely ideal representations used to illustrate embodiments of the present invention. Other aspects, purposes, and advantages of the present invention will be more clearly seen by reading the detailed description below and by reference to the drawings provided as non-limiting examples. [Brief explanation of the drawing]

[0018] [Figure 1] This is a perspective view of an injection device using conventional technology. [Figure 2A] This figure shows the plunger rod of the injection device in Figure 1 from a side view. [Figure 2B] This figure shows a cross-sectional view of the plunger rod of the injection device shown in Figure 1. [Figure 3] This is a perspective view of a plunger rod. [Figure 4] This is a side view of the plunger rod positioned inside the syringe barrel. [Figure 5] Figure 3 is a cross-sectional view of the plunger rod. [Figure 6] This figure shows the backstop in cross-section. [Figure 7] This diagram shows the backstop in strabismus. [Figure 8] This diagram shows the backstop on the top surface. [Figure 9] This is a diagram showing another backstop in strabismus. [Figure 10] This is a top view of another backstop. [Figure 11] This is a perspective view of a different backstop. [Figure 12] Figures 10 and 11 show perspective views of modified backstops. [Figure 13] Here is yet another perspective view of the backstop. [Figure 14] Here is yet another top view of a backstop. [Figure 15] Figures 13 and 14 are perspective views of modified backstops. [Modes for carrying out the invention]

[0019] Detailed explanation Figure 3 is a perspective view of the plunger rod 100. Figure 4 is a side view of the plunger rod 100 positioned inside the syringe barrel 140. Figure 5 is a cross-sectional view of the plunger rod 100.

[0020] The plunger rod 100 includes an elongated body 102 having a central axis 104 extending between a proximal end 106 and a distal end 108. In one embodiment, the central axis 104 of the plunger rod 100 may coincide with the corresponding central axis of the syringe barrel 140. The elongated body 102 of the plunger rod 100 also includes a first curved end face 110, a second curved end face 112, and a joint 114 joining the first curved end face 110 to the second curved end face 112. The first and second curved end faces 110 and 112 may also be formed of multiple straight segments or multiple corresponding adjacent segments. In one embodiment, each of the first curved end face 110, the second curved end face 112, and the joint 114 extends between the proximal end 106 and the distal end 108. At least the first curved end face 110 and the second curved end face 112 may together be inscribed by a circle defined by the outer circumference 130 (shown in Figure 5) of the elongated body 102. As shown, the outer circumference 130 may be discontinuous. As will be described later, the shape of the plunger rod 100 allows the plunger rod 100 to be manufactured with less material and formed in a shorter cycle time.

[0021] The plunger rod 100 may optionally further include a thumb press 126 located at the proximal end 106 of the elongated body 102 and a threaded connector 128 located at the distal end 108 of the elongated body 102. The thumb press 126 includes a portion wider than the internal dimensions of the syringe barrel 140 and provides a structure for the user to press when advancing the plunger rod 100 through the syringe barrel 140. The circumference and diameter of the arcuate outer circumference 130 may be smaller than the circumference and diameter of the arcuate outer circumference of the thumb press 126.

[0022] The stopper 127 can be screwed onto the connecting portion 128. Alternatively, the stopper 127 can be clipped to the plunger rod 100. During operation, the user can apply force to the thumb press 126 to advance the plunger rod 100 and the stopper 127 within the syringe barrel 140. The stopper 127 is sized relative to the syringe barrel 140 to provide a sealed engagement with the inner surface of the side wall of the syringe barrel 140. It should be noted herein that any suitable stopper may be used with the plunger rod 100.

[0023] When assembled, the elongated body 102 is positioned at least partially within the syringe barrel 140. The syringe barrel 140 may be of a typical elongated cylindrical shape, but it may also be of other shapes for containing the fluid to be delivered.

[0024] The syringe barrel 140 extends axially between the distal end 142 and the proximal end 144. The barrel 140 is configured to contain a medical fluid. The barrel 140 has an inner surface that defines a hollow space in which a stopper 127 may be placed. A cannula (e.g., a needle) for injecting medication into a patient may be coupled to the distal end 142. The needle may be stacked on the distal end 142 or coupled to the distal end 142 by screwing it in via an adapter that is snap-fitted or bonded to the distal end 142.

[0025] The syringe barrel 140 may be formed from glass or injection molded from thermoplastic materials such as polypropylene and polyethylene according to techniques known to those skilled in the art, but it should be understood that the syringe barrel 140 may be manufactured from other suitable materials according to other applicable techniques.

[0026] Continuing to refer to Figures 3 and 5, the plunger rod 100 may have several support ribs (two support ribs 116 and 118 are shown) extending from the elongated body 102 between the proximal end 106 and the distal end 108. The support ribs 116 and 118 may extend radially, for example, perpendicularly, with respect to the central axis 104, and the plunger rod according to the disclosed concept may include up to five ribs.

[0027] As best shown in Figure 5, the joint 114 includes an intermediate surface 120, a first connecting surface (e.g., a first angled surface 122, not limited to) extending from the intermediate surface 120 to a first curved end surface 110, and a second connecting surface (e.g., a second angled surface 124, not limited to) extending from the intermediate surface 120 to a second curved end surface 112.

[0028] The angled surfaces 122 and 124 may be curved or straight. The joint 114 may be a concave surface facing the central axis 104, at least partially defining the arcuate outer circumference 130 of the elongated body 102. In one exemplary embodiment, the intermediate surface 120 and the curved end surfaces 110, 112 may be inscribed together by a circle defined by the outer circumference 130 of the elongated body 102. Furthermore, the intermediate surface 120 may be curved or straight. Thus, it will be understood that the arcuate outer circumference 130 may be discontinuous.

[0029] Furthermore, the first and second connecting surfaces may include first and second angled surfaces 122 and 124 with respect to the intermediate surface 120, respectively. More specifically, in one exemplary embodiment, the first and second angled surfaces 122 and 124 extend from the intermediate surface 120 at angles θ1 and θ2, respectively, equal to or greater than 90 degrees with respect to the intermediate surface 120. Preferably, angles θ1 and θ2 are less than 120 degrees with respect to the intermediate surface 120. Furthermore, in one configuration, none of the first curved end face 110, the second curved end face 112, and / or any portion of the joint 114 intersect the central axis 104 of the elongated body 102 (shown as a circle to represent an axis perpendicular to the plane of paper). Thus, in this configuration, the central axis 104 of the plunger rod 100 is missing material. Furthermore, it should be noted that in certain embodiments, the first curved end face 110 and the second curved end face 112 do not intersect with each other; that is, the first curved end face 110 and the second curved end face 112 do not form a continuous outer circumference.

[0030] In practice, the shape of the plunger rod 100 offers many advantages over known plunger rods, such as the plunger rod 16 shown in Figures 2A and 2B. For example, having a discontinuous arc-shaped outer circumference 130 and having portions that do not intersect with each other, the elongated body 102 can be advantageously manufactured using less material than the conventional plunger rod 100. As previously mentioned with reference to Figure 2B, the first planar portion 21 and the second planar portion 23 intersect in a central region 25. It can be easily seen that the central region 25 has an undesirably large amount of material due to the intersection of the first planar portion 21 and the second planar portion 23. This is disadvantageous for at least the following reasons: Firstly, the material cost for manufacturing the plunger rod 16 is relatively high due to the increased amount of material present in this region. Secondly, the cycle time associated with forming the plunger rod 16 is relatively long due to the time required to cool the large central region 25.

[0031] The plunger rod 100 in Figures 3-5 solves these problems by having a gap in the central axis 104, which otherwise might generate a large amount of material in its central region, and the associated costs can be reduced. Furthermore, the plunger rod 100 can resist breakage with better resistance to bending (e.g., displacement away from the central axis 104) than the conventional plunger rod 16 during movement within the syringe barrel 140, and can resist breakage using less material. Due to the increased resistance to breakage, the plunger rod 100 can be manufactured from different materials (e.g., thermoplastic materials such as polycarbonate, polypropylene, polystyrene, etc., but not limited to these) than the plunger rod 16.

[0032] Figures 6-9 show a backstop 150 that can be used with the plunger rod 100 described herein. The backstop 150 includes an upper plate 160 and a lower plate 180. At least one connector 170 extends between the upper plate 160 and the lower plate 180 to connect the upper plate 160 and the lower plate 180.

[0033] The upper plate 160 has an upper surface 162 and an opposing lower surface 164. In some embodiments, the upper surface 162 and the lower surface 164 may be substantially flat and extend parallel to each other.

[0034] The lower plate 180 has an upper surface 182 and an opposing lower surface 184. The lower plate 180 is designed so that the user can grasp the injection device 101 and move the plunger rod 100 within the barrel 140. The lower surface 184 of the lower plate 180 may include one or more recesses shaped to receive the user's index and / or middle fingers for grasping the injection device 101, while the user's thumb rests on the thumb press 126 of the plunger rod 100.

[0035] The lower surface 164 and the upper surface 182 of the lower plate 180 are separated by a certain distance, defining a space between them. The space is sized to hold the flange 148 of the syringe barrel 140. For example, the height of the space may be substantially equal to the thickness of the flange 148 measured between the upper surface 145 and the lower surface 143 of the flange 148.

[0036] The upper plate 160 includes a first opening 166. The first opening 166 is configured to receive the plunger rod 100 and to allow the elongated body 102 of the plunger rod 100 to pass through it. The first opening 166 extends completely through the upper plate 160 (for example, from the top surface 162 to the bottom surface 164).

[0037] At least three flat surfaces 165, 167, and 169 define the first opening 166. The first flat surface 167 and the second flat surface 169 face each other and are positioned close to the opposing ends of the third flat surface 165. The first flat surface 167 and the second flat surface 169 may extend parallel to each other when the flat surfaces 167 and 169 extend away from the third flat surface 165. The first flat surface 167 and the second flat surface 169 may extend in a spreading shape when the flat surfaces 167 and 169 extend away from the third flat surface 165.

[0038] The first flat surface 167 and the second flat surface 169 may extend substantially parallel to the angled surfaces 122, 124 of the plunger rod 100. Thus, when the plunger rod 100 is advanced within the syringe barrel 140 when the user applies force to the thumb press 126, the plunger rod 100 may pass through the first opening 166.

[0039] The lower plate 180 includes a second opening 186. The second opening 186 has a different size and shape from the first opening 166. The second opening 186 is configured to hold the syringe barrel 140 within it. The surface 185 defining the second opening is generally arc-shaped to correspond to the arc-shaped outer surface of the syringe barrel 140.

[0040] In one configuration, as shown in Figures 6 and 7, the backstop 150 includes a connector 170 extending along a portion of the first side surface 161 of the upper plate 160 and along a portion of the first side surface 181 of the lower plate 180. The first side surface 161 of the upper plate 160 is positioned opposite the second side surface 163 of the upper plate 160, and a first opening 166 opens in the second side surface 163, so that the plunger rod 100 can be received therein during assembly of the injection device. The first side surface 181 of the lower plate 180 is positioned opposite the second side surface 183 of the lower plate 180, and a second opening 186 opens in the second side surface 183, so that the syringe barrel 140 can be received therein.

[0041] The connector 170 extends almost vertically between the upper plate 160 and the lower plate 180, and along one side of the upper plate 160 and the lower plate 180, so that a large portion of the area around the flange 148 of the syringe barrel 140 is not connected by the backstop 150.

[0042] In an alternative configuration, as shown in Figure 9, the backstop 150 comprises two opposing connectors 170. Each of the two connectors 170 extends from the first side 161 of the upper plate 160 and the first side 181 of the lower plate 180 toward the second side 163 of the upper plate 160 and the second side 183 of the lower plate 180.

[0043] The installation of two opposing connectors 170 is relative to the width W of the upper plate 160, which has a single connector 170. 160result in an increase, while, depth D 160 is maintained. The two opposing connectors 170 extend along two sides of the upper plate 160 and the lower plate 180, and most of the periphery around the flange 148 of the syringe barrel 140 is not joined by the backstop 150.

[0044] In any embodiment, the connector 170 extends around a small portion around the space where the flange 148 of the syringe barrel 140 is received. This limits the manufacturing cost and time by reducing the amount of material used.

[0045] The upper plate 160 is designed such that when the plunger rod 100, the syringe barrel 140, and the backstop 150 are assembled together, the stopper 127 connected to the connecting portion 128 of the plunger rod 100 is prevented from being removed from the syringe barrel 140, while allowing the elongated body 102 to pass through the first opening 126. The upper plate 160 has a width W sufficient to provide abutment against the upper surface 145 of the flange 148 160 and depth D 160 and has.

[0046] The upper plate 160 is dimensioned to minimize the amount of material used in its construction. The width W of the upper plate 160 160 is smaller than the width W of the lower plate 180 180 The depth D of the upper plate 160 160 is smaller than the depth D of the lower plate 180 180 Thus, the volume of the upper plate 160 is smaller than the volume of the lower plate 180.

[0047] The depth D of the upper plate 160 160 is selected to avoid contact between the support ribs 116, 118 and the upper plate 160, and when the user applies force to the thumb press 126, the plunger rod 100 passes through the first opening 166.

[0048] Width W of the first opening 166 of the upper plate 160 166 The width W of the second opening 186 of the lower plate 180 186 It may be smaller than the width W of the first opening 166. 166 The width W of the distal end 108 of the plunger rod 100. 108 Selected to be smaller than the distal end 108 of the plunger rod 100 to prevent it from being pulled out of the syringe barrel 140. 166 The distance between the angled surfaces 122 and 124 of the joint 114 is selected to be greater than the distance between them, so that when the user applies force to the thumb press 126, the plunger rod 100 passes through the first opening 166.

[0049] Figures 10-12 show another backstop 200 that can be used with the plunger rod 100 described herein. The backstop 200 includes an upper plate 210, a lower plate 230, and at least one connector 220 extending between them. The backstop 200 is substantially similar to the backstop 150, except that the overall shape of the lower plate 230 and the upper plate 210 differs from that of the upper plate 160 and the lower plate 180.

[0050] Similar to the upper plate 160, the upper plate 210 has an upper surface 212 and an opposing lower surface 214, which are substantially flat and may extend parallel to each other.

[0051] The lower plate 230 has an upper surface 212 and an opposing lower surface 214. The lower plate 230 is designed so that the user can grasp the injection device 101 and move the plunger rod 100 within the barrel 140. The lower surface 234 of the lower plate 230 is substantially flat and is configured so that the user's index and / or middle fingers rest there to grasp the injection device 101, while the user's thumb is positioned on the thumb press 126 of the plunger rod 100.

[0052] The lower surface 234 and upper surface 232 of the lower plate 230 are separated by a certain distance, defining a space between them, which is sized to hold the flange 148 of the syringe barrel 140 within it, as described above.

[0053] The upper plate 210 includes a first opening 216. Similar to the upper plate 160, at least three flat surfaces 215, 217, and 219 define the first opening 166. The first flat surface 215 and the second flat surface 217 may extend parallel to each other, or the flat surfaces 217 and 219 may extend in a manner that widens as they extend away from the third flat surface 165.

[0054] The lower plate 230 includes a second opening 236 configured to hold the syringe barrel 140. In one configuration, as shown in Figures 10 and 11, the backstop 200 includes a single connector 220 extending along a portion of the first side surface 211 of the upper plate 210 and along a portion of the first side surface 231 of the lower plate 230. The first side surface 211 of the upper plate 210 faces the second side surface 213 of the upper plate 210, and the first opening 216 opens in the second side surface 213, thereby receiving the plunger rod 100 during assembly of the infusion device. The first side surface 231 of the lower plate 230 faces the second side surface 233 of the lower plate 230, and the second opening 236 opens in the second side surface 233, thereby receiving the syringe barrel 140.

[0055] As shown in Figure 12, in an alternative configuration, the backstop 200 comprises two opposing connectors 220. Each of the two connectors 220 extends from the first side 211 of the upper plate 210 and the first side 231 of the lower plate 230 toward the second side 213 of the upper plate 210 and the second side 233 of the lower plate 230.

[0056] In either embodiment, the connector 220 extends substantially vertically between the upper plate 210 and the lower plate 230, and along one or two sides of the upper plate 210 and the lower plate 230, and most of the area around the flange 148 of the syringe barrel 140 is not coupled by the backstop 200. This reduces material usage and limits manufacturing costs and time.

[0057] The installation of two opposing connectors 220 is compared to the upper plate 210 having one connector 220, with a width W of the upper plate 210. 210 This leads to an increase in depth D 210 Maintain the following: The two opposing connectors 220 extend along the two sides of the upper plate 210 and the lower plate 230, and most of the area around the flange 148 of the syringe barrel 140 is not coupled by the backstop 200.

[0058] The size and shape of the first opening 216 in the upper plate 210 differ from the size and shape of the second opening 236 in the lower plate 230. As described with respect to the backstop 150, the first opening 216 is configured to receive the plunger rod 100 and allow the elongated body 102 of the plunger rod 100 to pass through it. The first opening 216 extends completely through the upper plate 210 (for example, from the top surface 212 to the bottom surface 214).

[0059] The upper plate 210 is designed to prevent the stopper 127, which is connected to the coupling portion 128 of the plunger rod 100, from being removed from the syringe barrel 140 when the plunger rod 100, syringe barrel 140, and backstop 200 are assembled together. The upper plate 210 has a width W sufficient to provide contact with the upper surface 145 of the flange 148. 210 and depth D 210 It has a mechanism to maintain the syringe barrel 140 within the backstop 200.

[0060] The top plate 210 is sized to minimize the amount of material used in its construction. Width W of the top plate 210 210 The width of the lower plate is 230 W 230 It is smaller than that. Furthermore, the depth D of the top plate 210 210 The depth D of the lower plate 230 230 It is smaller than the volume of the upper plate 210. Therefore, the volume of the upper plate 210 is smaller than the volume of the lower plate 230.

[0061] Depth D of the top plate 210 210 The support ribs 116, 118 are selected to avoid contact between the support ribs 116, 118 and the upper plate 210, so that the plunger rod 100 passes through the first opening 216 when the user applies force to the thumb press 126.

[0062] Width W of the first opening 216 of the upper plate 210 216 The width W of the second opening 236 of the lower plate 230 236 It may be smaller than the width W of the first opening 216. 216 The width W of the distal end 108 of the plunger rod 100. 108 Selected to be smaller than the distal end 108 of the plunger rod 100 to prevent it from being pulled out of the syringe barrel 140. 216 The distance between the angled surfaces 122 and 124 of the joint 114 is selected to be greater than the distance between the angled surfaces 122 and 124, so that when the user applies force to the thumb press 126, the plunger rod 100 passes through the first opening 216.

[0063] Figures 13–15 show another embodiment of a backstop 250 that can be used with the plunger rod 100 described herein. The backstop 250 includes an upper plate 260, a lower plate 280, and at least one connector 270 extending between them. The backstop 250 is substantially similar to the backstop 150, except that the overall shape of the lower plate 280 and the upper plate 260 differs from that of the upper plate 160 and the lower plate 180.

[0064] Similar to the upper plate 160, the upper plate 260 has an upper surface 262 and an opposing lower surface 264, which may be substantially flat and may extend parallel to each other.

[0065] The lower plate 280 has an upper surface 282 and an opposing lower surface 284. The lower plate 280 is designed so that the user can grasp the injection device 101 and move the plunger rod 100 within the barrel 140. The lower surface 284 of the lower plate 280 is substantially flat and is configured so that the user's index and / or middle fingers rest there to grasp the injection device 101, while the user's thumb is positioned on the thumb press 126 of the plunger rod 100.

[0066] The lower surface 284 and upper surface 282 of the lower plate 280 are separated by a certain distance, defining a space between them, which is sized to hold the flange 148 of the syringe barrel 140 within it, as described above.

[0067] The upper plate 260 includes a first opening 266. Similar to the upper plate 160, at least three flat surfaces 265, 267, and 269 define the first opening 266. The first flat surface 265 and the second flat surface 267 may extend parallel to each other, or in a diverging manner as the flat surfaces 267 and 269 extend away from the third flat surface 265.

[0068] The lower plate 280 includes a second opening 286 configured to hold the syringe barrel 140. In one configuration, as shown in Figures 13-15, the backstop 250 includes a single connector 270 extending along a portion of the first side surface 261 of the upper plate 260 and along a portion of the first side surface 281 of the lower plate 280. The first side surface 261 of the upper plate 260 faces the second side surface 263 of the upper plate 260, and the first opening 266 opens in the second side surface 263, thereby receiving the plunger rod 100 during the assembly of the injector 101. The first side surface 281 of the lower plate 280 faces the second side surface 283 of the lower plate 280, and the second opening 286 opens in the second side surface 283, receiving the syringe barrel 140.

[0069] In an alternative configuration, as shown in Figure 15, the backstop 250 comprises two opposing connectors 270. Each of the two connectors 270 extends from the first side 261 of the upper plate 260 and the first side 281 of the lower plate 280 toward the second side 263 of the upper plate 260 and the second side 283 of the lower plate 280.

[0070] The installation of two opposing connectors 270 is compared to the upper plate 260 having one connector 270, with a width W of the upper plate 260. 260 This leads to an increase in depth D 260 Maintain the following: Two opposing connectors 270 extend along the two sides of the upper plate 260 and the lower plate 280, and most of the area around the flange 148 of the syringe barrel 140 is not coupled by the backstop 250.

[0071] In either embodiment, the connector 270 extends substantially perpendicularly between the upper plate 260 and the lower plate 280, and along one or two sides of the upper plate 260 and the lower plate 280, with most of the area around the flange 148 of the syringe barrel 140 not being coupled by the backstop 250. This limits manufacturing costs and time by reducing the amount of material used.

[0072] The size and shape of the first opening 266 in the upper plate 260 differ from the size and shape of the second opening 286 in the lower plate 280. The first opening 266 is configured to receive the plunger rod 100 and allow the elongated body 102 of the plunger rod 100 to pass through it. The first opening 266 extends completely through the upper plate 260 (for example, from the top surface 262 to the bottom surface 264).

[0073] The upper plate 260 is designed to prevent the stopper 127, which is connected to the coupling portion 128 of the plunger rod 100, from being removed from the syringe barrel 140 when the plunger rod 100, syringe barrel 140, and backstop 250 are assembled together. The upper plate 260 has a width W sufficient to provide contact with the upper surface 145 of the flange 148. 260 and depth D 260 It holds.

[0074] The top plate 260 is sized to minimize the amount of material used in its construction. Width W of top plate 260 260 The width of the lower plate is 280 W 280 Smaller than that. The depth of the top plate is 260 D. 260 The depth D of the lower plate 280 280 It is smaller than. Therefore, the volume of the upper plate 260 is smaller than the volume of the lower plate 280.

[0075] Width W of the first opening 266 of the upper plate 260 266The width W of the second opening 286 of the lower plate 280 286 It may be smaller than the width W of the first opening 266. 266 The width W of the distal end 108 of the plunger rod 100. 108 Selected to be smaller than the distal end 108 of the plunger rod 100 to prevent withdrawal from the syringe barrel 140. 266 The distance between the angled surfaces 122 and 124 of the joint 114 is selected to be greater than the distance between them, so that when the user applies force to the thumb press 126, the plunger rod 100 passes through the first opening 266.

Claims

1. A backstop device (150, 200, 250) for maintaining the distal end (108) of a plunger rod (100) within a syringe barrel (140), wherein the plunger rod (100) has an elongated body (102) having a joint (114) that joins a first curved end face (110) to a second curved end face (112), the joint (114) defining a gap around the central axis (104) of the plunger rod, and the backstop device (150, 200, 250) is, The upper plates (160, 210, 260) define a first opening (166, 216, 266) therein, which is configured to receive only a portion of the joint (114) of the plunger rod (100). Lower plates (180, 230, 280), wherein the lower plates (180, 230, 280) define a second opening (186, 236, 286) configured to receive the syringe barrel (140), and the first opening (166, 216, 266) has a shape different from that of the second opening (186, 236, 286), and the lower plates (180, 230, 280) A backstop device (150, 200, 250) characterized by comprising at least one connector (170, 220, 270) extending between the upper plate (160, 210, 260) and the lower plate (180, 230, 280).

2. A backstop device (150, 200, 250) according to claim 1, wherein the first opening (166, 216, 266) of the upper plate (160, 210, 260) is defined by a first flat surface (167, 217, 267), a second flat surface (169, 219, 269), and a third flat surface (165, 215, 265), the first flat surface and the second flat surface are positioned close to the opposing ends of the third flat surface (165), and extend from the third flat surface in a parallel or radially spreading manner.

3. A backstop device (150, 200, 250) according to claim 1 or 2, wherein the maximum depth (D) of the upper plate (160, 210, 260) 160 , D 210 , D 260 ) is the maximum depth (D) of the lower plate (180, 230, 280). 180 , D 230 , D 280 Backstop devices (150, 200, 250) characterized by being smaller than ).

4. The backstop device (150, 200, 250) according to any one of claims 1 to 3, wherein the maximum width (W 160 , W 210 , W 260 ) of the upper plate (160, 210, 260) is smaller than the maximum width (W 180 , W 230 , W 280 ) of the lower plate (180, 230, 280). The backstop device (150, 200, 250) is characterized by this.

5. A backstop device (150, 200, 250) according to any one of claims 1 to 4, wherein the second opening (186, 236, 286) of the lower plate (180, 230, 280) is defined at least partially by an arcuate surface (185, 235, 285), and the curvature of the arcuate surface (185, 235, 285) corresponds to the curvature of the outer surface of the syringe barrel (140) that is received therein.

6. A backstop device (150, 200, 250) according to any one of claims 1 to 5, characterized in that the upper surface (162, 212, 262) and lower surface (164, 214, 264) of the upper plate (160, 210, 260) extend substantially parallel to each other.

7. A backstop device (150, 200, 250) according to any one of claims 1 to 6, wherein the at least one connector (170, 220, 270) of the backstop device (150, 200, 250) extends along a portion of the first side surface (161, 211, 261) of the upper plate (160, 210, 260) and along a portion of the first side surface (181, 231, 281) of the lower plate (180, 230, 280), and the first side surface (161, 211, 261) of the upper plate (160, 210, 260) extends along the second side surface (183, 233, 283) of the upper plate (160, 210, 260) A backstop device (150, 200, 250) characterized in that the first opening (166, 216, 266) is located on the second side surface (183, 233, 283) opposite the lower plate (180, 230, 280), and the second opening (186, 236, 286) is located on the second side surface (183, 233, 283), and the syringe barrel (140) is located therein.

8. A backstop device (150, 200, 250) according to any one of claims 1 to 6, wherein the at least one connector (170, 220, 270) of the backstop device (150, 200, 250) comprises two opposing connectors (170, 220, 270), each of the two connectors (170, 220, 270) is on the first side of the upper plate (160, 210, 260) Backstop devices (150, 200, 250) characterized by extending from the surfaces (161, 211, 261) and the first side surfaces (181, 231, 281) of the lower plates (180, 230, 280) toward the second side surfaces (163, 213, 263) of the upper plates (160, 210, 260) and the second side surfaces (183, 233, 283) of the lower plates (180, 230, 280).

9. A backstop device (150, 200, 250) according to any one of claims 1 to 8, characterized in that the volume of the upper plate (160) is smaller than the volume of the lower plate (180, 230, 280).

10. An injection device (101), wherein the injection device (101) is Syringe barrel (140) and, A plunger rod (100) comprising an elongated body (102) extending along a central axis (104) between a proximal end (106) and a distal end (108), wherein the body has a joint (114) joining a first curved end face (110) to a second curved end face (112), the joint (114) defining a gap around the central axis (104), and each of the first curved end face (110), the second curved end face (112), and the joint (114) extending between the proximal end (106) and the distal end (108), and together the first curved end face (110) and the second curved end face (112) defining a discontinuous arc-shaped outer circumference of the elongated body (102), the plunger rod (100), An injection device (101) comprising a backstop device (150, 200, 250) according to any one of claims 1 to 9.

11. The injection device (101) according to claim 10, wherein the distance (W) between the first flat surface (167, 217, 267) and the second flat surface (169, 219, 269) of the first opening (166, 216, 266) of the upper plate (160, 210, 260) is 166 , W 216 , W 266 The injection device (101) is characterized in that its diameter is smaller than the diameter of the distal end (108) of the plunger rod (100).

12. An injection device (101) according to claim 10 or 11, wherein the lower plates (180, 230, 280) are separated from the upper plates (160, 210, 260) by a certain distance, and when the backstop device (150, 200, 250) is coupled to the syringe barrel (140), the lower surface (164) of the upper plates (160, 210, 260) and the upper surfaces (182, 232, 282) of the lower plates (180, 230, 280) are in contact with the upper surface (157) and lower surface (159) of the flange (158) of the syringe barrel (140), respectively.

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