Self-controllable 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 relates generally 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 technology]

[0002] [CROSS REFERENCE TO RELATED APPLICATIONS] This application claims the benefit of U.S. Provisional Patent Application No. 62 / 872,017, filed July 9, 2019, and U.S. Utility Patent Application No. 16 / 922,137, filed July 7, 2020, the contents of which are incorporated herein by reference in their entireties.

[0003] Medical injection devices often utilize elastic members, such as springs, placed between various components to bias the components to ensure more accurate drug delivery. However, there are drawbacks to the use of current elastic members used in medical injection devices, such as 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] U.S. Pat. No. 9,421,334 Summary of the Invention

[0005] 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.

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

[0007] Also provided herein is a load spring washer configured for use with a medical injection device having a circular main body having a frusto-conical shape.

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

[0009] Also provided herein is a medical injection device 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 actuation member at a proximal end of the housing, the actuation member configured to actuate the medical injection device to deliver the 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, the load spring washer comprising 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.

[0012] 2. The load spring washer of clause 1, wherein the main body is substantially circular.

[0013] 3. A load spring washer as in clause 1 or clause 2, wherein the main body defines an opening such that the main body is ring-shaped.

[0014] 4. The load spring washer of any of clauses 1-3, wherein a cross-sectional profile of the one or more protrusions along a plane extending between the proximal surface and the distal surface comprises a parallelogram.

[0015] 5. A load spring washer according to any of clauses 1 to 3, wherein the protrusion or protrusions have a cylindrical shape.

[0016] 6. The load spring washer of clause 5, wherein a cross-sectional profile of the one or more protrusions along a plane extending between the proximal surface and the distal surface comprises a cylindrical shape.

[0017] 7. A load spring washer of Clause 5 or Clause 6, the cylindrical shape defining a hollow interior.

[0018] 8. A load spring washer as per Clause 7, the hollow interior of which is gas filled.

[0019] 9. A load spring washer as per Clause 7, the hollow interior containing a vacuum.

[0020] 10. The load spring washer of any of clauses 1-3, wherein a cross-sectional profile of the one or more protrusions along a plane extending between the proximal surface and the distal surface includes a rhomboid.

[0021] 11. The load spring washer of any of clauses 1-3, wherein a cross-sectional profile of the one or more protrusions along a plane extending between the proximal surface and the distal surface includes an S-shape.

[0022] 12. The load spring washer of any of clauses 1-3, wherein a cross-sectional profile of the one or more protrusions along a plane extending between the proximal surface and the distal surface includes an L-shape.

[0023] 13. A load spring washer according to any of clauses 1 to 3, wherein the main body comprises a plurality of rings.

[0024] 14. The load spring washer of clause 13, wherein the plurality of rings comprises concentric circles, with a gap between each of the concentric circles.

[0025] 15. The load spring washer of clause 14, wherein at least one of said concentric circles has a width greater than a width of another of said concentric circles.

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

[0027] 17. The load spring washer of any of clauses 13-15, wherein the one or more protrusions comprise an arch having 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, both of the first arm and the second arm extending parallel to a longitudinal axis defined by the proximal and distal surfaces of the main body, and a curved portion connected to the first arm and the second arm.

[0028] 18. A load spring washer according to any of clauses 1 to 3, wherein the protrusion comprises a frusto-conical portion.

[0029] 19. A load spring washer of any of clauses 1 to 18, wherein the load spring washer comprises an elastomeric material.

[0030] 20. A load spring washer of any of clauses 1 to 19 containing rubber.

[0031] 21. A load spring washer according to any of clauses 1 to 20, wherein the load spring washer is formed from ethylene propylene diene monomer rubber.

[0032] 22. The load spring washer of any of clauses 1 to 21, wherein the Shore A hardness of the load spring washer is 20 to 40, preferably 30 to 40.

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

[0034] 24. A load spring washer having a circular main body having a frusto-conical shape.

[0035] 25. A load spring washer comprising 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 a longitudinal axis defined by the proximal and distal surfaces of the main body.

[0036] 26. A load spring washer of any of clauses 23 to 25, wherein the load spring washer contains an elastomeric material.

[0037] 27. A load spring washer according to any of clauses 23 to 26, including a rubber load spring washer.

[0038] 28. A load spring washer according to any of clauses 23 to 27, wherein the load spring washer is formed from ethylene propylene diene monomer rubber.

[0039] 29. The load spring washer of any of clauses 23 to 28, wherein the Shore A hardness of the load spring washer is 20 to 40, preferably 30 to 40.

[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 actuation member at a proximal end of the housing, the actuation member configured to actuate the medical injection device to deliver the composition through the injection needle. [Brief description of the drawings]

[0041] [Figure 1A] 1A-1D illustrate various embodiments or aspects of a load spring washer as described herein. [Figure 1B] 1A-1C illustrate various embodiments or aspects of a load spring washer as described herein. [Figure 1C] 1A-1D illustrate various embodiments or aspects of a load spring washer as described herein. [Diagram 2] 1 is a schematic image of a load spring washer according to one non-limiting embodiment or aspect. [Figure 3A] 1 is a schematic image of a load spring washer according to one non-limiting embodiment or aspect. [Figure 3B] FIG. 13 is a force diagram showing the bending of a pillar of a load spring washer. [Figure 4A] 1 is a schematic image of a load spring washer in accordance with a non-limiting embodiment or aspect. [Figure 4B] 1 is a schematic image of a load spring washer in accordance with a non-limiting embodiment or aspect. [Diagram 5] 1 is a schematic image of a load spring washer according to one non-limiting embodiment or aspect. [Figure 6A] 1 is a schematic image of a load spring washer in accordance with a non-limiting embodiment or aspect. [Figure 6B] 1 is a schematic image of a load spring washer in accordance with a non-limiting embodiment or aspect. [Figure 6C] 1 is a schematic image of a load spring washer in accordance with a non-limiting embodiment or aspect. [Figure 6D] 1 is a schematic image of a load spring washer in accordance with a non-limiting embodiment or aspect. [Figure 7A] 1 is a schematic image of a load spring washer in accordance with a non-limiting embodiment or aspect. [Figure 7B] 1 is a schematic image of a load spring washer in accordance with a non-limiting embodiment or aspect. [Figure 7C] 1 is a schematic image of a load spring washer in accordance with a non-limiting embodiment or aspect. [Figure 8A] 1 is a schematic image of a load spring washer in accordance with a non-limiting embodiment or aspect. [Figure 8B] 1 is a schematic image of a load spring washer in accordance with a non-limiting embodiment or aspect. [Figure 8C] 1 is a schematic image of a load spring washer in accordance with a non-limiting embodiment or aspect. [Figure 8D] 1 is a schematic image of a load spring washer in accordance with a non-limiting embodiment or aspect. [Figure 9A] 1 is a schematic image of a load spring washer in accordance with a non-limiting embodiment or aspect. [Figure 9B] 1 is a schematic image of a load spring washer in accordance with a non-limiting embodiment or aspect. [Figure 10A] 1 is a schematic image of a load spring washer in accordance with a non-limiting embodiment or aspect. [Figure 10B] 1 is a schematic image of a load spring washer in accordance with a non-limiting embodiment or aspect. [Figure 11A] 1A-1D illustrate various embodiments or aspects of a load spring washer as described herein. [Figure 11B] 1A-1D illustrate various embodiments or aspects of a load spring washer as described herein. [Figure 11C] 1A-1D illustrate various embodiments or aspects of a load spring washer as described herein. [Figure 11D] 1A-1D illustrate various embodiments or aspects of a load spring washer as described herein. [Figure 11E]1A-1D illustrate various embodiments or aspects of a load spring washer as described herein. [Figure 12A] FIG. 13 illustrates a load spring washer and its placement within a housing of a drug delivery device, according to a non-limiting embodiment or aspect. [Figure 12B] FIG. 13 illustrates a load spring washer and its placement within a housing of a drug delivery device, according to a non-limiting embodiment or aspect. [Figure 13A] FIG. 13 illustrates a load spring washer and its placement within a housing of a drug delivery device, according to a non-limiting embodiment or aspect. [Figure 13B] FIG. 13 illustrates a load spring washer and its placement within a housing of a drug delivery device, according to a non-limiting embodiment or aspect. [Figure 14A] FIG. 13 illustrates a load spring washer and its placement within a housing of a drug delivery device, according to a non-limiting embodiment or aspect. [Figure 14B] FIG. 13 illustrates a load spring washer and its placement within a housing of a drug delivery device, according to a non-limiting embodiment or aspect. [Figure 15A] FIG. 13 illustrates a load spring washer and its placement within a housing of a drug delivery device, according to a non-limiting embodiment or aspect. [Figure 15B] FIG. 13 illustrates a load spring washer and its placement within a housing of a drug delivery device, according to a non-limiting embodiment or aspect. [Figure 16] FIG. 1 is an exploded view of a medical injection device including a load spring washer as described herein. [Figure 17] 1 is a graph illustrating load versus tension for one non-limiting embodiment or aspect of a load spring washer described herein. [Figure 18A] 1 is a schematic image of a load spring washer in accordance with a non-limiting embodiment or aspect. [Figure 18B] 1 is a schematic image of a load spring washer in accordance with a non-limiting embodiment or aspect. [Figure 19A]1 is a schematic image of a load spring washer in accordance with a non-limiting embodiment or aspect. [Figure 19B] 1 is a schematic image of a load spring washer in accordance with a non-limiting embodiment or aspect. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0042] The use of numerical values ​​in the various ranges specified in this application, unless expressly stated otherwise, are stated as approximations, as if both the minimum and maximum values ​​in the stated range were preceded by the word "about". As used herein, the term "about" means the stated value ±10%. Thus, slight variations above and below the stated range can be used to achieve substantially the same results as the values ​​within the range. Also, unless otherwise stated, the disclosure of these ranges is intended as a continuous range including every value between the minimum and maximum values. With respect to the definitions provided herein, these definitions refer to forms, cognates, and grammatical variations of those words or phrases.

[0043] The figures accompanying this application are representative in nature and should not be construed to imply any particular scale or orientation unless otherwise specified. For purposes of the following description, the terms "upper", "lower", "right", "left", "vertical", "horizontal", "top", "lower", "lateral", "longitudinal" and their derivatives shall refer to the present invention as oriented in the drawings. However, it should be understood that the present invention may assume various alternative variations and step sequences unless expressly specified to the contrary. Thus, specific dimensions and other physical characteristics relating to the embodiments disclosed herein should not be considered limiting.

[0044] Provided herein are load spring washers for use as a replacement for springs in medical devices. A spring washer is an axially flexible washer, as known to those skilled in the art. As used herein, the "spring" aspect of a spring washer for use in a medical device is a washer that has axial flexibility due to the material from which it is formed (e.g., compressibility / expansion resulting from the elastomeric nature of the material), the shape or form of the washer, and combinations thereof. In non-limiting embodiments or aspects, the load spring washer is formed from an elastomeric material. In non-limiting embodiments or aspects, the elastomeric material is a highly elastic elastomeric 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 elastomeric copolymer, including, but not limited to, a thermoplastic elastomer, a thermoplastic vulcanizate, a styrene copolymer, such as a styrene-butadiene (SBR or SBS) copolymer, a styrene-isoprene (SIS) block polymer, or a styrene-isoprene / butadiene (SIBS), in which the styrene content in the styrene block copolymer is about 10% to about 70%, and preferably about 20% to about 50%. The elastomeric composition can include, but is not limited to, antioxidants and / or inorganic reinforcing agents that maintain the stability of the elastomeric composition, vulcanizing agents, vulcanization accelerators, vulcanization activators, processing aids, fillers, etc., to maintain and improve the physical properties and heat resistance of the rubber material.

[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, including all values ​​and subranges therebetween. In non-limiting embodiments or aspects, the load spring washer is formed from a material including ethylene propylene diene monomer (EPDM) rubber. In non-limiting embodiments or aspects, the load spring washer is formed from a material including 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), cure accelerators (e.g., TBzTD), vulcanizing agents (e.g., VULTAC710), and sulfur (such as hydrated sulfur).

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

[0048] With reference to Figures 1A-1C, various load spring washers 100 as described herein are shown. The load spring washers shown in Figures 1A-1C are substantially circular. However, one of ordinary skill in the art will appreciate that any suitable shape may be used depending on the intended use / application. Figures 11A-11E show various non-limiting embodiments or aspects of shapes that may be utilized for the load spring washers 100 as described herein, including circular, ring-shaped, star-shaped, and h-shaped. It should be understood that the shapes shown are merely exemplary and the disclosure is not so limited.

[0049] Referring to FIG. 2, a schematic diagram of a load spring washer 100 is shown according to a non-limiting embodiment or aspect. In a non-limiting embodiment or aspect, the load spring washer 100 can include a main body 105 and one or more protrusions 110, such as pillars, extending from the main body 105. The main body includes a proximal surface 101 and a distal surface 102 that define a longitudinal axis therebetween. Without wishing to be bound by theory, it is believed that the pillars 110 allow for modification of the compressive force of the load spring washer by providing resistance to compression. Although FIG. 2 (and other figures) shows a particular number of protrusions, such as pillars, it should be understood that the number of protrusions, such as pillars 110, can be modified to provide appropriate modification of the compressive force for an intended application. The protrusions 110 can assume any useful shape and orientation on the load spring washer main body 105. Those skilled in the art will appreciate that the thickness (depth) and circumferential extent (width) of the main body 105 can be adjusted so long 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 and distal surfaces 101, 102 of the main body 105.

[0050] Referring to FIG. 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 protrusions 110, with a gap 120 between a proximal (top) portion of the S-shaped protrusion and the main body 105 having a predetermined height. The design of the protrusions 110 in FIG. 3 allows the protrusions to bend or buckle in a flat orientation when a force is applied in a direction perpendicular to the main body 105, as shown in FIG. 3B, such that the height of the gap 120 is less than when no force is applied to the load spring washer 100. As previously mentioned, the protrusions, here the S-shaped protrusions, including their individual portions, may be of any suitable size, and the gap 120 may be of any suitable size as well.

[0051] 4A-B, a schematic diagram of a load spring washer 100 is shown according to a non-limiting embodiment or aspect. The load spring washer 100 includes a main body 105 and one or more L-shaped protrusions 110 with a gap 120 between a proximal (top) portion of the L-shaped protrusions 110 and the main body 105. As previously mentioned, the protrusions, here the L-shaped protrusions, including their individual portions, may be of any suitable size and the gap 120 may likewise be of any suitable size.

[0052] Referring to FIG. 5, a schematic diagram of a load spring washer 100 is shown according to a non-limiting embodiment or aspect. The load spring washer 100 includes a multi-piece main body including an inner portion 107 and an outer portion 109. In a non-limiting embodiment or aspect, the inner portion 107 and the outer portion 109 are at least two concentric circles. In a non-limiting embodiment or aspect, at least one of the concentric circles has a width greater than a width of another of the concentric circles. The stop spring washer 100 further includes one or more protrusions 110. In the illustrated embodiment or aspect, the protrusions include a proximal (top) end and a distal (bottom) end, the protrusions 110 bridge the inner portion 107 and the outer portion 109 of the main body, and a gap 120 is between the proximal end of the protrusion 110 and the inner portion 107 and the outer portion 109 of the main body. The protrusions 110 have a square shape in FIG. 5. However, the disclosure is not so limited and the projections 100 may assume any useful shape or orientation, such as, for example, but not limited to, an arch or vaulted shape.

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

[0054] 7A-7C, there are shown schematic top (FIG. 7A) and side (FIG. 7B-7C) views of a load spring washer 100 according to a non-limiting embodiment or aspect. In the illustrated non-limiting embodiment or aspect, the load spring washer 100 has a wave shape. Although FIGS. 7B-7C show a sine wave shape including peaks 150 and valleys 140, it should be understood that the disclosure is not so limited and various wave shapes may be used, such as, but not limited to, square waves, sawtooth waves, and triangular waves, so long as the wave shape provides the desired buckling characteristics described herein. Additionally, although not shown in FIGS. 7A-7C, in a non-limiting embodiment or aspect, the wave load spring washer 100 further includes one or more protrusions 110 as described herein.

[0055] 8A-8D, there are shown a top ( FIG. 8A ), side ( FIG. 8B ), cross-sectional ( FIG. 8C ), and perspective ( FIG. 8D ) views of a load spring washer 100 according to a non-limiting embodiment or aspect. In the illustrated non-limiting embodiment or aspect, the load spring washer 100 includes a main body 105 and a frusto-conical portion 170 at a proximal (top) end of the main body 105. The frusto-conical portion 170 may assume the orientation illustrated in FIGS. 8B-8C (larger circumference at its proximal end) or the opposite orientation (larger circumference at its distal (bottom) end, not shown). In the illustrated non-limiting embodiment or aspect, the portion of frustoconical portion 170 having the greater circumference is disposed at the proximal (top) end, and a gap 180 having a height is defined between the proximal (top) end of frustoconical portion 170 and the proximal surface 101 of main body 105. In the illustrated non-limiting embodiment or aspect, the proximal-most end of frustoconical portion 170 buckles toward the distal (bottom) end of load spring washer 100 when a force is applied to load spring washer 110 in a direction parallel to a longitudinal axis defined by the proximal and distal surfaces 101, 102 of main body 105 such that the height of gap 180 is less than when no force is applied to load spring washer 100.

[0056] 9A-9B, a perspective view (FIG. 9A) and a cross-sectional view (FIG. 9B) of a load spring washer 100 are shown in accordance with a non-limiting embodiment or aspect. In the illustrated non-limiting embodiment or aspect, the load spring washer 100 has a frusto-conical shape with the proximal surface 101 being narrower (smaller circumference) than the distal surface 102, although 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 a longitudinal axis defined by the proximal and distal surfaces 101, 102.

[0057] 10A-10B, a perspective view (FIG. 10A) and a cross-sectional view (FIG. 10B) of a load spring washer 100 are shown in accordance with a non-limiting embodiment or aspect. The load spring washer 100 shown in FIGS. 10A-10B includes a protrusion 110. The protrusion 110 is oriented in a manner that provides the load spring washer 100 with a frusto-conical shape when considered with the main body 105, as best shown in the cross-sectional view of FIG. 10B. In the illustrated non-limiting embodiment or aspect, the protrusion 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 a longitudinal axis defined by the proximal and distal surfaces 101, 102 of the main body 105.

[0058] 12A-12B, a non-limiting embodiment or aspect of a load spring washer 200 is shown that includes a main body 205, at least one flange 210, and / or at least one arm 225. FIG. 12B shows the load spring washer 200 within a medical injection device housing 250. The flange 210 can be defined by a portion 215 that extends outwardly from an outer diameter of the main body 205 and a portion 220 that extends substantially perpendicular to portion 215. The length of portions 215 and 220 can be adjusted based on the medical device into which the load spring washer 200 is to be deployed.

[0059] Arm 225 can include a portion 215 that extends outwardly from an outer diameter of main body 205 and a portion 220 that extends substantially perpendicular to portion 215. Arm 225 further includes a portion 230 that extends substantially perpendicular to portion 220. In a non-limiting embodiment or aspect, portion 230 is substantially parallel to portion 215.

[0060] 13A-13B, there is shown a non-limiting embodiment or aspect of a load spring washer 300. Figure 13B shows the load spring washer 300 within a medical injection device housing 350. In the illustrated non-limiting embodiment or aspect, the load spring washer 300 is a ring-shaped foam member.

[0061] 14A-14B, a non-limiting embodiment or aspect of a load spring washer 400 is shown. FIG. 14B shows the load spring washer 400 within a medical injection device housing 450. In the illustrated non-limiting embodiment or aspect, the load spring washer 400 includes one or more protrusions 410 and / or a pattern cut into the proximal surface 401. In the illustrated non-limiting embodiment or aspect, the load spring washer 400 is a ring-shaped rubber-based member. Without wishing to be bound by theory, it is believed that the pattern allows for buckling of various portions of the load spring washer 400 as described herein.

[0062] 15A-15B, a non-limiting embodiment is shown in which a load spring washer is not used. Rather, the brake tower 500 of the medical injection device (described in more detail below) includes one or more elastomeric projections 510 on its proximal surface. Without wishing to be bound by theory, it is believed that the elastomeric projections 510 enable the buckling described herein. FIG. 15B shows the brake tower 500 within a medical injection device housing 550.

[0063] Also provided herein is a medical injection device including the load spring washer described above. Such devices, such as injection pens, are described, for example and without limitation, in U.S. Patent No. 6,399,363, which is incorporated herein by reference in its entirety. Referring to FIG. 16, an exploded view of an injection pen 51 for 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 a plurality of 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 the cartridge holder 14 when the injection pen is not in use. As shown, the injection pen 51 may include a dose setting knob 2 that includes a knob-like portion that is rotated by a user to set a desired dose. The dose setting knob 2 may also include a plurality of numbers corresponding to the number of dosage 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 pen upper body 1 may include an arrow or other indicator 53 to pinpoint the set dose. Once the desired dose is set, the user presses the button 3 until the set dosage is fully injected. An outer shield 69 may cover the needle 56 to prevent accidental needle sticks upon removal of the lower pen cap 12.

[0064] The injection pen 51 includes a push button 3 at the proximal end, closest to the user and furthest from the needle 56 of the pen upper body 1. The push button 3 may include an annular bead or rim 57 that engages with a corresponding annular groove (not shown) 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 into the dose setting knob 2 to inject the set dose. The interior of the push button 3 may accommodate a setback bearing insert 8 that rests on the inner surface at the proximal end of the setback member or driver 9. The push button 3 may be designed to rotate freely on the setback bearing insert 8.

[0065] The setback member or driver 9 can be a cylindrical member coaxial with and surrounded by the dose setting knob 2. The setback member 9 can be coaxially disposed around a brake tower 5 axially and rotatably fixed to the pen upper body 1. The brake tower 5 coaxially surrounds a piston rod 6. The piston rod 6 includes a set of keys 62 that engage slots (not shown) in the interior of the brake tower 5 to rotatably lock the piston rod 6 to the brake tower 5. The piston rod 6 can include a plurality of threads (not shown) disposed on its interior surface. The piston rod 6 can coaxially surround a lead screw 4 that includes at least a series of threads 42 at its distal end. The lead screw threads 42 can be configured to threadably engage with an internal thread (not shown) disposed on the interior of the piston rod 6. Due to its threaded engagement with the lead screw 4, the piston rod 6 can be moved into the cartridge 15 during injection to push a stopper 16 disposed inside the cartridge 15 to expel a dose of medication.

[0066] With reference to the present disclosure, the injection pen 51 includes a load spring washer 11 disposed between the distal end of the brake tower 5 and the cartridge 15 and / or cartridge holder 14 to bias the cartridge 15 in a distal direction, thereby reducing / preventing movement of the cartridge 15. Reducing and / or preventing movement of the cartridge 15 can greatly reduce and improve penetration of the needle 56 into the cartridge 15 prior to loading.

[0067] [example] The load spring washer was formed from a highly resilient elastomeric material containing the following components:

[0068] [Table 1]

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

[0070] [Table 2-1]

[0071] [Table 2-2]

[0072] [Table 3]

[0073] Additionally, data (compressive load vs. compressive tension) from the above samples is shown in FIG.

[0074] In addition, 19 more samples were produced from a silicone-based rubber material durometer Shore A35, where silicone rubber rings were cut using a 14 mm outer diameter die and then drilled with a 10 mm (samples 5, 6, and 7 in Tables 4 and 5) or 12 mm (others) inner diameter die. The rings were cut from ASTM rubber plates 6.5” (16.51 cm) L x 6.5” (16.51 cm) W and 1.8 to 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 pull was 1.5 mm.

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

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

[0077] [Table 4-1]

[0078] [Table 4-2]

[0079] [Table 5]

[0080] Finally, an additional 14 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 and 5 and Tables 6 and 7 exhibited different orders of magnitude of buckling and were performed with the expectation of limiting the developed forces in compression and tension to a maximum of less than 1.5 mm. The variation in maximum compression force is due to either the 1.5 mm width of the rings in Samples 5, 6, and 7 in Tables 4 and 5 or the perforation and centering of the die during ring manufacture. In practice, process variability resulted in asymmetric cross sections of the rings, which facilitated the buckling concept approach.

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

Claims

1. 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; one or more protrusions extending proximally from the proximal surface of the main body; Equipped with each of the one or more projections defines a gap between a projection portion of the respective projection and the main body; Load spring washer.

2. When a force is applied to the load spring washer, the height of the gap decreases.

2. The load spring washer of claim 1.

3. The shape of the one or more protrusions is a parallelogram.

2. The load spring washer of claim 1.

4. The shape of the one or more protrusions is rhomboid.

2. The load spring washer of claim 1.

5. The shape of the one or more protrusions is S-shaped.

2. The load spring washer of claim 1.

6. The shape of the one or more protrusions is L-shaped.

2. The load spring washer of claim 1.

7. The main body comprises a plurality of rings.

2. The load spring washer of claim 1.

8. the one or more protrusions are U-shaped; The U-shape is a first arm connected to the main body; a second arm connected to the main body; a cross member connected to the first arm and the second arm; Equipped with the gap is between the cross member and the main body; 2. The load spring washer of claim 1.

9. the shape of the one or more protrusions defines an arch; a first arm connected to the main body; a second arm connected to the main body; a curved portion connected to the first arm and the second arm; Equipped with the gap is between the curved portion and the main body; 2. The load spring washer of claim 1.

10. the one or more protrusions comprise a frusto-conical portion; 2. The load spring washer of claim 1.

11. the load spring washer comprises an elastomeric material.

2. The load spring washer of claim 1.

12. the load spring washer comprises rubber; 2. The load spring washer of claim 1.

13. the load spring washer is formed from ethylene propylene diene monomer rubber; 2. The load spring washer of claim 1.

14. The Shore A hardness of the load spring washer is 20 to 40.

2. The load spring washer of claim 1.

15. The main body is annular.

2. The load spring washer of claim 1.

16. The main body is frusto-conical in shape.

2. The load spring washer of claim 1.

17. 1. A medical injection device comprising: a housing having a proximal end, a distal end and a sidewall therebetween defining an interior; a brake member received within the interior of the housing; a cartridge holder received within the interior of the housing distal to the brake member; a cartridge received in said cartridge holder and holding a composition therein; a load spring washer comprising a main body having a proximal surface and a distal surface, and one or more protrusions extending proximally from the proximal surface of the main body, each of the one or more protrusions defining a gap between a protruding portion of the respective protrusion and the main body; an injection needle in fluid communication with the cartridge and disposed at a distal end of the housing; an actuation member disposed 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, the one or more protrusions abut the brake member and the distal surface abuts the cartridge and / or the cartridge holder, biasing the cartridge and / or the cartridge holder in a distal direction to prevent any movement of the cartridge during injection. Medical injection device.

18. the height of the gap decreases in response to a force applied to the load spring washer; 18. The medical injection device of claim 17.

19. when a force is applied to the load spring washer, the height of the one or more protrusions decreases.

18. The medical injection device of claim 17.

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