Self-regulating load spring washer

Abstract

To provide a more robust load spring washer to allow greater load recovery.SOLUTION: Provided herein is a load spring washer configured for use with a medical injection device, having: a main body having a proximal surface and a distal surface; and one or more protrusions extending proximally away from the proximal surface of the main body.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure generally relates to spring washers useful as alternatives to helical coil springs for medical devices, and in certain embodiments or aspects, to injection devices including spring washers, including elastomeric spring washers.

Background Art

[0002] [Cross - Reference to Related Applications] This application claims the benefit of U.S. Provisional Patent Application No. 62 / 872,017, filed Jul. 9, 2019, and U.S. Utility Patent Application No. 16 / 922,137, filed Jul. 7, 2020, the contents of which are hereby incorporated by reference in their entirety.

[0003] Medical injection devices often utilize elastic members, such as springs, placed between various components to bias the components in order to ensure more accurate drug delivery. However, there are drawbacks to the use of current elastic members in medical injection devices, such as a lack of control and load recovery. Thus, there is a need in the art for more robust components that allow for greater load recovery.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

[0005] A load spring washer configured for use with a medical injection device is provided, having a main body with a proximal surface and a distal surface, and one or more protrusions extending proximally away from the proximal surface of the main body.

[0006] A load spring washer having a circular main body with a proximal surface and a distal surface, configured for use with a medical injection device, wherein the cross-sectional shape of the main body along a plane extending between the proximal and distal surfaces has a sinusoidal shape.

[0007] Load spring washers configured for use with medical injection devices having a circular main body with a frustoconical shape are also provided herein.

[0008] A load spring washer configured for use with a medical injection device, having a main body comprising a ring having a proximal surface and a distal surface, the load spring washer comprising at least one arm and / or one flange projecting parallel to the longitudinal axis defined by the proximal and distal surfaces of the main body.

[0009] A medical injection device is also provided herein, having a housing, a brake member received within the housing, a cartridge received within the housing and holding a composition therein, a load spring washer as described herein, received within the housing and positioned between the brake member and the housing, an injection needle in fluid communication with the cartridge, and an actuator at the proximal end of the housing, configured to actuate the medical injection device to deliver a composition through the injection needle.

[0010] Further embodiments or aspects are described in the following numbered clauses.

[0011] 1. A load spring washer configured for use with a medical injection device, comprising a main body having a proximal surface and a distal surface, and one or more projections extending proximal to and away from the proximal surface of the main body.

[0012] 2. A load spring washer according to Clause 1, the main body of which is substantially circular.

[0013] 3. The main body is a load spring washer according to Clause 1 or Clause 2, which defines the opening so that the main body is ring-shaped.

[0014] 4. A load spring washer according to any of clauses 1 to 3, wherein the cross-sectional shape of one or more projections along a plane extending between the proximal and distal surfaces includes a parallelogram.

[0015] 5. A load spring washer according to any of clauses 1 to 3, wherein one or more projections are cylindrical.

[0016] 6. A load spring washer according to Clause 5, wherein the cross-sectional shape of one or more projections along a plane extending between the proximal and distal surfaces includes a cylindrical shape.

[0017] 7. A cylindrical load spring washer according to Clause 5 or Clause 6, defining a hollow interior.

[0018] 8. The hollow interior is filled with gas, load spring washer according to Clause 7.

[0019] 9. A load spring washer according to Clause 7, with a hollow interior containing a vacuum.

[0020] 10. A load spring washer according to any of clauses 1 to 3, wherein the cross-sectional shape of one or more projections along a plane extending between the proximal and distal surfaces includes a rhombic shape.

[0021] 11. A load spring washer according to any of clauses 1 to 3, wherein the cross-sectional shape of one or more projections along a plane extending between the proximal and distal surfaces includes an S-shape.

[0022] 12. A load spring washer according to any of clauses 1 to 3, wherein the cross-sectional shape of one or more projections along a plane extending between the proximal and distal surfaces includes an L-shape.

[0023] 13. A load spring washer according to any of clauses 1 to 3, the main body comprising multiple rings.

[0024] 14. The plurality of rings includes concentric circles, and there are gaps between each of the concentric circles, the load spring washer of clause 13.

[0025] 15. At least one of the concentric circles has a width greater than the width of another one of the concentric circles, the load spring washer of clause 14.

[0026] 16. The cross-sectional profile of one or more protrusions along a plane extending between a proximal surface and a distal surface includes a U-shape, and the U-shape includes a first arm connected to a first one of the plurality of rings of the main body and a second arm connected to a second one of the plurality of rings of the main body, and both the first arm and the second arm extend parallel to the longitudinal axis defined by the proximal surface and the distal surface of the main body, the first arm and the second arm, and a transverse member connected to the first arm and the second arm and extending perpendicular to the longitudinal axis defined by the proximal surface and the distal surface of the main body, the load spring washer of any one of clauses 13-15.

[0027] 17. One or more protrusions include a first arm connected to a first one of the plurality of rings of the main body and a second arm connected to a second one of the plurality of rings of the main body, and both the first arm and the second arm extend parallel to the longitudinal axis defined by the proximal surface and the distal surface of the main body, the first arm and the second arm, and an arch including a curved portion connected to the first arm and the second arm, the load spring washer of any one of clauses 13-15.

[0028] 18. The protrusion includes a frustum-shaped portion, the load spring washer of any one of clauses 1-3.

[0029] 19. The load spring washer includes an elastomeric material, the load spring washer of any one of clauses 1-18.

[0030] 20. The load spring washer includes rubber, the load spring washer of any one of clauses 1-19.

[0031] 21. The load spring washer is formed from ethylene propylene diene monomer rubber, as specified in any of clauses 1 to 20.

[0032] 22. The load spring washer has a Shore A hardness of 20 to 40, preferably 30 to 40, according to any of the load spring washers in Clauses 1 to 21.

[0033] 23. A load spring washer comprising a circular main body having a proximal surface and a distal surface, wherein the cross-sectional outer shape of the main body along a plane extending between the proximal and distal surfaces is sinusoidal.

[0034] 24. A load spring washer having a circular main body with a frustoconical shape.

[0035] 25. A load spring washer comprising a main body having a ring having a proximal surface and a distal surface, the load spring washer comprising at least one arm and / or one flange projecting parallel to the longitudinal axis defined by the proximal and distal surfaces of the main body.

[0036] 26. Load spring washers include elastomer material, as specified in any of clauses 23-25.

[0037] 27. Load spring washers include rubber, any load spring washer specified in clauses 23-26.

[0038] 28. The load spring washer is formed from ethylene propylene diene monomer rubber, as specified in any of clauses 23 to 27.

[0039] 29. The load spring washer has a Shore A hardness of 20-40, preferably 30-40, according to any of the load spring washers in clauses 23-28.

[0040] 30. A medical injection device comprising a housing, a brake member received within the housing, a cartridge received within the housing and holding a composition therein, a load spring washer according to any of clauses 1 to 29, received within the housing and positioned between the brake member and the housing, an injection needle in fluid communication with the cartridge, and an actuator at the proximal end of the housing, configured to actuate the medical injection device to deliver a composition through the injection needle. [Brief explanation of the drawing]

[0041] [Figure 1A] This figure shows various embodiments or aspects of the load spring washer described herein. [Figure 1B] This figure shows various embodiments or aspects of the load spring washer described herein. [Figure 1C] This figure shows various embodiments or aspects of the load spring washer described herein. [Figure 2] This is a schematic diagram of a load spring washer according to one non-limiting embodiment or aspect. [Figure 3A] This is a schematic diagram of a load spring washer according to one non-limiting embodiment or aspect. [Figure 3B] This is a force diagram showing the bending of the pillar of a load spring washer. [Figure 4A] This is a schematic diagram of a load spring washer according to a non-limiting embodiment or aspect. [Figure 4B] This is a schematic diagram of a load spring washer according to a non-limiting embodiment or aspect. [Figure 5] This is a schematic diagram of a load spring washer according to one non-limiting embodiment or aspect. [Figure 6A] This is a schematic diagram of a load spring washer according to a non-limiting embodiment or aspect. [Figure 6B] This is a schematic diagram of a load spring washer according to a non-limiting embodiment or aspect. [Figure 6C] This is a schematic diagram of a load spring washer according to a non-limiting embodiment or aspect. [Figure 6D] This is a schematic diagram of a load spring washer according to a non-limiting embodiment or aspect. [Figure 7A] This is a schematic diagram of a load spring washer according to a non-limiting embodiment or aspect. [Figure 7B] This is a schematic diagram of a load spring washer according to a non-limiting embodiment or aspect. [Figure 7C] This is a schematic diagram of a load spring washer according to a non-limiting embodiment or aspect. [Figure 8A] This is a schematic diagram of a load spring washer according to a non-limiting embodiment or aspect. [Figure 8B] This is a schematic diagram of a load spring washer according to a non-limiting embodiment or aspect. [Figure 8C] This is a schematic diagram of a load spring washer according to a non-limiting embodiment or aspect. [Figure 8D] This is a schematic diagram of a load spring washer according to a non-limiting embodiment or aspect. [Figure 9A] This is a schematic diagram of a load spring washer according to a non-limiting embodiment or aspect. [Figure 9B] This is a schematic diagram of a load spring washer according to a non-limiting embodiment or aspect. [Figure 10A] This is a schematic diagram of a load spring washer according to a non-limiting embodiment or aspect. [Figure 10B] This is a schematic diagram of a load spring washer according to a non-limiting embodiment or aspect. [Figure 11A] This figure shows various embodiments or aspects of the load spring washer described herein. [Figure 11B] This figure shows various embodiments or aspects of the load spring washer described herein. [Figure 11C] This figure shows various embodiments or aspects of the load spring washer described herein. [Figure 11D] This figure shows various embodiments or aspects of the load spring washer described herein. [Figure 11E]This figure shows various embodiments or aspects of the load spring washer described herein. [Figure 12A] This figure shows a load spring washer and its placement within the housing of a drug delivery device, according to a non-limiting embodiment or aspect. [Figure 12B] This figure shows a load spring washer and its placement within the housing of a drug delivery device, according to a non-limiting embodiment or aspect. [Figure 13A] This figure shows a load spring washer and its placement within the housing of a drug delivery device, according to a non-limiting embodiment or aspect. [Figure 13B] This figure shows a load spring washer and its placement within the housing of a drug delivery device, according to a non-limiting embodiment or aspect. [Figure 14A] This figure shows a load spring washer and its placement within the housing of a drug delivery device, according to a non-limiting embodiment or aspect. [Figure 14B] This figure shows a load spring washer and its placement within the housing of a drug delivery device, according to a non-limiting embodiment or aspect. [Figure 15A] This figure shows a load spring washer and its placement within the housing of a drug delivery device, according to a non-limiting embodiment or aspect. [Figure 15B] This figure shows a load spring washer and its placement within the housing of a drug delivery device, according to a non-limiting embodiment or aspect. [Figure 16] This is an exploded view of a medical injection device including a load spring washer as described herein. [Figure 17] This is a graph showing the load under tension for one non-limiting embodiment or aspect of a load spring washer described herein. [Figure 18A] This is a schematic diagram of a load spring washer according to a non-limiting embodiment or aspect. [Figure 18B] This is a schematic diagram of a load spring washer according to a non-limiting embodiment or aspect. [Figure 19A]This is a schematic diagram of a load spring washer according to a non-limiting embodiment or aspect. [Figure 19B] This is a schematic diagram of a load spring washer according to a non-limiting embodiment or aspect. [Modes for carrying out the invention]

[0042] The use of numerical values ​​within the various ranges specified herein is, unless otherwise explicitly stated, to be as follows: the minimum and maximum values ​​within the stated ranges are both stated as approximations, preceded by the word “approximately.” As used herein, the term “approximately” means ±10% of the stated value. Thus, slight variations above and below the stated ranges are usable to substantially achieve the same results as values ​​within the range. Furthermore, unless otherwise specified, these disclosures are intended as a continuous range encompassing all values ​​between the minimum and maximum values. With respect to the definitions provided herein, those definitions refer to the forms, cognates, and grammatical variations of those words or phrases.

[0043] The drawings accompanying this application are representative in nature and should not be construed as implying any particular scale or orientation unless otherwise specified. For the purposes of the following description, the terms “upward,” “downward,” “right,” “left,” “vertical,” “horizontal,” “upper,” “lower,” “lateral,” and “longitudinal,” and their derivatives, are used in relation to the invention as oriented in the drawings. However, it should be understood that the invention may assume various alternative forms and step sequences unless explicitly specified otherwise. Therefore, specific dimensions and other physical characteristics relating to the embodiments disclosed herein should not be considered limiting.

[0044] Load spring washers for use as spring substitutes in medical devices are provided herein. A spring washer is a washer having axial flexibility, as is known to those skilled in the art. When used herein, the “spring” aspect of a spring washer for use in medical devices is a washer having axial flexibility, depending on the material from which the washer is formed (e.g., compressibility / expandability derived from the elastomeric nature of the material), the shape or form of the washer, and a combination thereof. In non-limiting embodiments or aspects, the load spring washer is formed from an elastomer material. In non-limiting embodiments or aspects, the elastomer material is a highly elastic elastomer material. In non-limiting embodiments or aspects, the load spring washer is formed from rubber. In non-limiting embodiments or aspects, the rubber is polyisoprene rubber, silicone rubber, and / or butyl rubber. In non-limiting embodiments or aspects, the rubber is butyl rubber (IIR), isoprene rubber (IR), butadiene rubber (BR), styrene-butadiene rubber (SBR), ethylene-propylene rubber (EPM), ethylene-propylene-diene rubber (EPDM), chlorosulfonated polyethylene (CSM), ethylene-vinyl acetate copolymer (EVA), styrene-isoprene rubber (SIR), thermoplastic elastomer, and / or natural rubber.

[0045] In non-limiting embodiments or aspects, the load spring washer is formed from an elastomer copolymer containing a thermoplastic elastomer, a thermoplastic vulcanized product, a styrene-butadiene (SBR or SBS) copolymer, a styrene-isoprene (SIS) block polymer, or a styrene copolymer such as styrene-isoprene / butadiene (SIBS), wherein the styrene content in the styrene block copolymer is about 10% to about 70%, and preferably about 20% to about 50%. The elastomer composition may include, but is not limited to, antioxidants and / or inorganic reinforcing agents, vulcanizing agents, vulcanization accelerators, vulcanization activators, processing aids, fillers, etc., to maintain and improve the physical properties and thermal resistance of the rubber material and to maintain the stability of the elastomer composition.

[0046] In non-limiting embodiments or aspects, the load spring washer is formed from a material having a Shore A value of 20–40, optionally 30–40, encompassing all values ​​and partial ranges between them. In non-limiting embodiments or aspects, the load spring washer is formed from a material containing ethylene propylene diene monomer (EPDM) rubber. In non-limiting embodiments or aspects, the load spring washer is formed from a material containing EPDM rubber and various fillers / additives. In non-limiting embodiments or aspects, the load spring washer is formed from ultra-high molecular weight EPDM rubber (e.g., KELTAN9565Q), various fillers (e.g., MISTRON Vapor), mineral oil, zinc oxide, stearic acid, antioxidants (e.g., SONGNOX1076), curing accelerators (e.g., TBzTD), vulcanizing agents (e.g., VULTAC710), and sulfur (e.g., hydrated sulfur).

[0047] In non-limiting embodiments or aspects, the load spring washer is formed from foam. In non-limiting embodiments or aspects, the load spring washer is formed from a mixture of materials, for example, metal and / or polymer together with rubber and / or foam, for example, but not limited to rubber and / or foam. For example, but not limited to load spring washers described below, the load spring washer may include a main body that is metal, polymer, or a mixture, along with protrusions formed from rubber, foam, or an elastomer material such as an elastomer polymer.

[0048] Referring to Figures 1A to 1C, various load spring washers 100 described herein are shown. The load spring washers shown in Figures 1A to 1C are substantially circular. However, those skilled in the art will understand that any suitable shape may be available depending on the intended use / application. Figures 11A to 11E show various non-limiting embodiments or aspects of shapes available for the load spring washers 100 described herein, including circular, ring-shaped, star-shaped, and h-shaped. It should be understood that the shapes shown are illustrative only and that this disclosure is not so limited.

[0049] Referring to Figure 2, a schematic diagram of a load spring washer 100 in a non-limiting embodiment or aspect is shown. In a non-limiting embodiment or aspect, the load spring washer 100 may include a main body 105 and one or more projections 110, such as pillars, extending from the main body 105. The main body includes a proximal surface 101 and a distal surface 102, defining a longitudinal axis between them. While we do not wish to be bound by theory, the pillars 110 are thought to allow for modification of the compressive force of the load spring washer by providing resistance to compression. Figure 2 (and other figures) shows a specific number of projections, such as pillars, but it should be understood that the number of projections, such as pillars 110, is modifiable to provide appropriate modification of the compressive force for the intended application. The projections 110 may assume any useful shape and orientation on the load spring washer main body 105. Those skilled in the art will understand that the thickness (depth) and circumferential size (width) of the main body 105 are adjustable, insofar as the load spring washer exhibits the characteristics described herein with respect to bending or buckling when a force or pressure is applied parallel to the longitudinal axis defined by the proximal surface 101 and distal surface 102 of the main body 105.

[0050] Referring to Figure 3A, a schematic diagram of a load spring washer 100 according to a non-limiting embodiment or aspect is shown. The load spring washer 100 includes a main body 105 and one or more S-shaped projections 110, the gap 120 between the proximal (uppermost) portion of the S-shaped projection and the main body 105 having a predetermined height. The design of the projection 110 in Figure 3 allows the projection to bend or buckle in a flat direction when a force is applied perpendicular to the main body 105, as shown in Figure 3B, such that the height of the gap 120 is smaller than when no force is applied to the load spring washer 100. As mentioned above, the projection, in this case the S-shaped projection, including its individual parts, may be of any suitable size, and the gap 120 may likewise be of any suitable size.

[0051] Referring to Figures 4A to 4B, schematic diagrams of load spring washers 100 according to non-limiting embodiments or aspects are shown. The load spring washer 100 includes a main body 105 and one or more L-shaped projections 110, with a gap 120 between the proximal (uppermost) portion of the L-shaped projection 110 and the main body 105. As mentioned above, the projections, in this case the L-shaped projections, including their individual parts, may be of any appropriate size, and the gap 120 may also be of any appropriate size.

[0052] Referring to Figure 5, a schematic diagram of a load spring washer 100 according to a non-limiting embodiment or aspect is shown. The load spring washer 100 includes a main body consisting of multiple parts, including an inner portion 107 and an outer portion 109. In the non-limiting embodiment or aspect, the inner portion 107 and the outer portion 109 are at least two concentric circles. In the non-limiting embodiment or aspect, at least one of the concentric circles has a width greater than the width of the other concentric circle. The retaining spring washer 100 further includes one or more projections 110. In the illustrated embodiment or aspect, the projection includes a proximal (upper) end and a distal (lower) end, and the projection 110 bridges the inner portion 107 and the outer portion 109 of the main body, with a gap 120 between the proximal end of the projection 110 and the inner portion 107 and the outer portion 109 of the main body. The projection 110 has a rectangular shape in Figure 5. However, the disclosure is not limited in this way, and the projection 100 may assume any useful shape or orientation, such as, for example, an arch or arched shape.

[0053] Referring to Figures 6A to 6D, schematic top view (Figure 6A), schematic side view (Figure 6B), schematic cross-sectional view (Figure 6C), and schematic perspective view (Figure 6D) of a load spring washer 100 according to a non-limiting embodiment or aspect are shown. The load spring washer 100 includes a main body 105 and a projection 110. In the non-limiting embodiment or aspect shown, the projection has a cylindrical shape and optionally has a dome 125 at its proximal (upper) end. In the non-limiting embodiment or aspect, the inside of the cylinder is hollow and may define a chamber 130. The presence of a chamber 130, which may be subjected to a vacuum during manufacturing so that no air is present within it, allows the walls of the dome (120) and / or projection 110 to collapse or buckle inward toward the distal (lowest) end of the load spring washer 100 when a force is applied to the load spring washer 110 parallel to the longitudinal axis defined by the proximal surface 101 and distal surface 102 of the main body 105. In a non-limiting embodiment or aspect, the outermost circumference of the main body 105 may include one or more projections that provide greater frictional engagement between the outer diameter of the main body 105 and the inner diameter of the medical device housing into which the load spring washer 100 may be introduced.

[0054] Referring to Figures 7A to 7C, schematic top view (Figure 7A) and schematic side view (Figures 7B to 7C) of a load spring washer 100 according to a non-limiting embodiment or aspect are shown. In the non-limiting embodiment or aspect shown, the load spring washer 100 has a waveform. Figures 7B to 7C show a sinusoidal wave including peaks 150 and troughs 140, but the disclosure is not limited in that sense, and it should be understood that various waveforms, such as, but not limited to, square waves, sawtooth waves, and triangular waves, may be used as long as the waveform provides the desired buckling characteristics described herein. In addition, although not shown in Figures 7A to 7C, in a non-limiting embodiment or aspect, the waveform load spring washer 100 further includes one or more projections 110 as described herein.

[0055] Referring to Figures 8A to 8D, a top view (Figure 8A), a side view (Figure 8B), a cross-sectional view (Figure 8C), and a perspective view (Figure 8D) of a load spring washer 100 according to a non-limiting embodiment or aspect are shown. In the non-limiting embodiment or aspect shown, the load spring washer 100 includes a main body 105 and a frustoconical portion 170 at the proximal (uppermost) end of the main body 105. The frustoconical portion 170 may assume an orientation as shown in Figures 8B to 8C (the larger circumference at its proximal end) or the opposite orientation (the larger circumference at its distal (lower) end, not shown). In the non-limiting embodiments or aspects shown, the portion of the frustoconical section 170 having the larger circumference is located at the proximal (uppermost) end, and a height gap 180 is defined between the proximal (uppermost) end of the frustoconical section 170 and the proximal surface 101 of the main body 105. In the non-limiting embodiments or aspects shown, the proximal end of the frustoconical section 170 buckles toward the distal (lower) end of the load spring washer 100 when a force is applied to the load spring washer 110 in a direction parallel to the longitudinal axis defined by the proximal surface 101 and distal surface 102 of the main body 105, such that the height of the gap 180 is smaller than when no force is applied to the load spring washer 100.

[0056] Referring to Figures 9A and 9B, perspective views (Figure 9A) and cross-sectional views (Figure 9B) of a load spring washer 100 according to a non-limiting embodiment or aspect are shown. In the illustrated non-limiting embodiment or aspect, the load spring washer 100 has a frustoconical shape, and the proximal surface 101 may be narrower (smaller circumference) than the distal surface 102, but opposite orientations may be used. In the illustrated non-limiting embodiment or aspect, the proximal surface 101 buckles toward the distal surface 102 of the load spring washer 100 when a force is applied to the load spring washer 110 in a direction parallel to the longitudinal axis defined by the proximal surface 101 and the distal surface 102.

[0057] Referring to Figures 10A and 10B, perspective views (Figure 10A) and cross-sectional views (Figure 10B) of a load spring washer 100 according to a non-limiting embodiment or aspect are shown. The load spring washer 100 illustrated in Figures 10A and 10B includes a projection 110. The projection 110 is oriented such that, when considered together with the main body 105, it provides the load spring washer 100 with a frustoconical shape, as best illustrated in the cross-sectional view of Figure 10B. In the non-limiting embodiment or aspect shown, the projection 110 buckles toward the distal surface 102 of the load spring washer 100 when a force is applied to the load spring washer 110 in a direction parallel to the longitudinal axis defined by the proximal surface 101 and distal surface 102 of the main body 105.

[0058] Referring to Figures 12A to 12B, non-limiting embodiments or aspects of a load spring washer 200 comprising a main body 205, at least one flange 210, and / or at least one arm 225 are shown. Figure 12B shows the load spring washer 200 within a medical injection device housing 250. The flange 210 can be defined by a portion 215 extending outward from the outer diameter of the main body 205 and a portion 220 extending substantially perpendicular to portion 215. The lengths of portions 215 and 220 are adjustable based on the medical device into which the load spring washer 200 is introduced.

[0059] The arm 225 may include a portion 215 extending outward from the outer diameter of the main body 205 and a portion 220 extending substantially perpendicular to the portion 215. The arm 225 further includes a portion 230 extending substantially perpendicular to the portion 220. In a non-limiting embodiment or aspect, the portion 230 is substantially parallel to the portion 215.

[0060] Referring to Figures 13A to 13B, non-limiting embodiments or aspects of the load spring washer 300 are shown. Figure 13B shows the load spring washer 300 within a medical injection device housing 350. In the non-limiting embodiments or aspects shown, the load spring washer 300 is a ring-shaped foam member.

[0061] Referring to Figures 14A to 14B, non-limiting embodiments or aspects of the load spring washer 400 are shown. Figure 14B shows the load spring washer 400 within a medical injection device housing 450. In the non-limiting embodiments or aspects shown, the load spring washer 400 includes one or more projections 410 and / or patterns cut into the proximal surface 401. In the non-limiting embodiments or aspects shown, the load spring washer 400 is a ring-shaped rubber base member. While we do not wish to be constrained by theory, the patterns appear to allow for buckling of various parts of the load spring washer 400 as described herein.

[0062] Referring to Figures 15A and 15B, a non-limiting embodiment is shown in which load spring washers are not used. Rather, the brake tower 500 of the medical injection device (described in more detail below) includes one or more elastomer protrusions 510 on its proximal surface. Although we do not wish to be bound by theory, it appears that the elastomer protrusions 510 enable the buckling described herein. Figure 15B shows the brake tower 500 within the medical injection device housing 550.

[0063] Medical injection devices including the load spring washer described above are also provided herein. Such devices, such as injection pens, are described, for example, in Patent Document 1, which is incorporated herein in whole by reference, but is not limited thereto. Referring to Figure 16, an exploded assembly diagram of an injection pen 51 for the delivery of a composition to a user is shown. As shown, the injection pen 51 includes a pen upper body or housing 1 that houses multiple dose settings and injection components. The pen upper body 1 is connected to a cartridge holder 14, which houses a drug cartridge 15. The injection pen 51 may also include a lower pen cap 12 that covers the cartridge 15 and cartridge holder 14 when the injection pen is not in use. As shown, the injection pen 51 may include a dose setting knob 2 which includes a knob-like portion that is rotated by the user to set a desired dose. The dose setting knob 2 may also include multiple digits corresponding to the number of dose units visible through a window 13 provided on the pen upper body 1. The user rotates the dose setting knob 2 until the desired dose is visible in the window 13. The upper body 1 of the pen may include an arrow or other indicator 53 to show the set dose precisely. Once the desired dose is set, the user presses button 3 until the set amount of medication is completely injected. The outer shield 69 can cover the needle 56 to prevent accidental needle sticks when removing the lower pen cap 12.

[0064] The injection pen 51 includes a push button 3 at its proximal end, positioned closest to the user and furthest from the needle 56 on the upper body 1 of the pen. The push button 3 may include an annular bead or rim 57 that engages with a corresponding annular groove (not shown) provided on the inner surface of the dose setting knob 2. The annular rim and groove connection may be a friction fit that maintains the push button 3 in a biased position on the dose setting knob 2 under the force of the button spring 10, but allows the push button 3 to be pressed onto the dose setting knob 2 to inject the set dose. The interior of the push button 3 may house a setback member or a setback bearing insert 8 that rests on the inner surface at the proximal end of the drive unit 9. The push button 3 may be designed to rotate freely on the setback bearing insert 8.

[0065] The setback member or drive unit 9 may be a cylindrical member coaxial with and surrounded by the dose setting knob 2. The setback member 9 may be coaxially mounted around a brake tower 5 that is axially and rotatably fixed to the pen upper body 1. The brake tower 5 coaxially surrounds the piston rod 6. The piston rod 6 includes a set of keys 62 that engage with slots (not shown) inside the brake tower 5 to rotatably lock the piston rod 6 to the brake tower 5. The piston rod 6 may include a plurality of threads (not shown) provided on its internal surface. The piston rod 6 may coaxially surround a lead screw 4 having at least a series of threads 42 at its distal end. The threads 42 of the lead screw may be configured to screw into a female screw (not shown) provided on the inside of the piston rod 6. Its screwing with the lead screw 4 allows the piston rod 6 to move towards the cartridge 15 during injection to push a stopper 16 provided inside the cartridge 15 to discharge a dose of the drug.

[0066] Referring to this disclosure, the injection pen 51 includes a load spring washer 11 provided between the distal end of the brake tower 5 and the cartridge 15 and / or cartridge holder 14 to bias the cartridge 15 distally, thereby reducing / preventing movement of the cartridge 15. Reducing and / or preventing movement of the cartridge 15 can greatly reduce and improve the intrusion of the needle 56 into the cartridge 15 before loading.

[0067] [example] The load spring washer was formed from a highly elastic elastomer material containing the following components.

[0068] [Table 1]

[0069] The materials described above were used to manufacture load spring washers of various orientations / shapes, as shown in Figure 11. The data is presented in the table below.

[0070] [Table 2-1]

[0071] [Table 2-2]

[0072] [Table 3]

[0073] In addition, data (compressive load vs. compressive tension) from the above samples is shown in Figure 17.

[0074] In addition, 19 more samples were produced from a silicone-based rubber material durometer Shore A35, where the silicone rubber rings were cut using a 14 mm outer diameter punching die, and then the inner diameter was perforated with a 10 mm (samples 5, 6, and 7 in Tables 4 and 5) or 12 mm (others) punching die. The rings were cut from ASTM rubber plates 6.5” (16.51 cm) L × 6.5” (16.51 cm) W and 1.8–2.0 mm thick. All samples in Tables 4 and 5 are the same test, but the forces are specified at different compression distances. The maximum compression tensile was 1.5 mm.

[0075] Tables 6 and 7 represent the same test, but the forces are specified at different compression distances. The maximum compression-tensile force was 1.5 mm.

[0076] All samples for Tables 4 and 5, 6 and 7 were prepared in the same manner by perforating rings from rubber slabs, with dimensions provided in Figures 18A and 18B (Figure 18A is a top view and Figure 18B is a cross-sectional view), and the data are presented below.

[0077] [Table 4-1]

[0078] [Table 4-2]

[0079] [Table 5]

[0080] Finally, 14 additional samples were produced using the dimensions provided in Figures 19A–19B (Figure 19A is a top view and Figure 19B is a cross-sectional view), and the data is presented below.

[0081] [Table 6]

[0082] [Table 7]

[0083] The tested rings in Tables 4, 5, 6, and 7 exhibited buckling of different girders and were performed with the expectation that the resulting compressive and tensile forces would be limited to a maximum of less than 1.5 mm. The variation in maximum compressive force is due to either the ring width of 1.5 mm in samples 5, 6, and 7 in Tables 4 and 5, or to the drilling and centering of the mold during ring manufacturing. In practice, process variability resulted in asymmetrical cross-sections of the rings, which facilitated the buckling concept method.

[0084] While the devices have been described in detail for illustrative purposes based on what is currently considered most practical and preferred embodiments, it should be understood that such details are for that purpose only, and the systems and methods are not limited to the embodiments of the present disclosure, but rather are intended to encompass modifications and equivalent arrangements that fall within the spirit and scope of the appended claims. For example, it should be understood that, to the extent possible, the systems and methods are intended to allow one or more features of any embodiment to be combined with one or more features of any other embodiment.

Claims

1. A load spring washer configured for use with a medical injection device, The main body is annular and has a proximal surface and a distal surface, One or more protrusions are arranged on the proximal surface of the main body and extend proximal to the proximal surface of the main body, Equipped with, A gap is defined between the proximal portion of each of the one or more protrusions and the proximal surface of the main body. In accordance with the force applied when one or more of the protrusions come into contact with the brake member of the medical injection device, the height of the gap between each of the proximal portions of the one or more protrusions and the proximal surface of the main body decreases. Load spring washer.

2. When a force is applied to the load spring washer, the height of one or more of the protrusions decreases. A load spring washer according to claim 1.

3. The shape of one or more of the aforementioned protrusions is a parallelogram. A load spring washer according to claim 1.

4. The shape of one or more of the aforementioned protrusions is rhombic. A load spring washer according to claim 1.

5. The shape of one or more of the aforementioned protrusions is S-shaped. A load spring washer according to claim 1.

6. The shape of one or more of the aforementioned protrusions is L-shaped. A load spring washer according to claim 1.

7. The main body comprises a plurality of rings, A load spring washer according to claim 1.

8. The shape of the one or more protrusions is U-shaped, The aforementioned U-shape is, A first arm connected to the main body, A second arm connected to the main body, A transverse member connected to the first arm and the second arm, Equipped with, The aforementioned gap is located between the transverse member and the main body. A load spring washer according to claim 1.

9. The shape of the one or more protrusions constitutes an arch. A first arm connected to the main body, A second arm connected to the main body, The curved portion connected to the first arm and the second arm, Equipped with, The gap is located between the curved portion and the main body. A load spring washer according to claim 1.

10. The one or more of the aforementioned protrusions have a frustoconical portion. A load spring washer according to claim 1.

11. The aforementioned load spring washer comprises an elastomer material. A load spring washer according to claim 1.

12. The aforementioned load spring washer is made of rubber. A load spring washer according to claim 1.

13. The aforementioned load spring washer is formed from ethylene propylene diene monomer rubber. A load spring washer according to claim 1.

14. The Shore A hardness of the aforementioned load spring washer is 20 to 40. A load spring washer according to claim 1.

15. The main body is cylindrical. A load spring washer according to claim 1.

16. The main body is frustoconical in shape. A load spring washer according to claim 1.

17. A medical injection device, A housing having a proximal end, a distal end, and a side wall between them defining the interior, A brake member received inside the housing, A cartridge holder is provided distal to the brake member, and is located inside the housing. A cartridge that is received in the cartridge holder and holds the composition therein, A load spring washer comprising: a main body which is annular and has a proximal surface and a distal surface; one or more projections disposed on the proximal surface of the main body and extending proximal from the proximal surface of the main body, wherein a gap is defined between each of the proximal portions of the one or more projections and the proximal surface of the main body, and the height of the gap between each of the proximal portions of the one or more projections and the proximal surface of the main body decreases in accordance with the force applied when the one or more projections come into contact with the brake member of the medical injection device; A syringe needle is in fluid communication with the cartridge and is located at the distal end of the housing, An actuator positioned at the proximal end of the housing and configured to actuate the medical injection device to deliver the composition through the injection needle, Equipped with, When the medical injection device is assembled, one or more protrusions abut against the brake member, and the distal surface abuts against the cartridge and / or the cartridge holder, thereby biasing the cartridge and / or the cartridge holder distally to prevent all movement of the cartridge during injection. Medical injection device.

18. When a force is applied to the load spring washer, the height of one or more of the protrusions decreases. A medical injection device according to claim 17.

Images