Self-Controllable Load Spring Washer
20210008282 ยท 2021-01-14
Inventors
- Nestor Rodriguez San Juan (Hamburg, NJ, US)
- Evan LEIBOWITZ (Linden, NJ, US)
- Kayla Kaspar (Parsippany, NJ, US)
Cpc classification
B21D53/22
PERFORMING OPERATIONS; TRANSPORTING
A61M5/31543
HUMAN NECESSITIES
C08K3/011
CHEMISTRY; METALLURGY
A61M5/2053
HUMAN NECESSITIES
C08L23/16
CHEMISTRY; METALLURGY
C08L23/16
CHEMISTRY; METALLURGY
A61M5/24
HUMAN NECESSITIES
C08K3/011
CHEMISTRY; METALLURGY
F16F1/328
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
C08L91/00
CHEMISTRY; METALLURGY
A61M5/2033
HUMAN NECESSITIES
A61M5/31585
HUMAN NECESSITIES
C08L91/00
CHEMISTRY; METALLURGY
A61M2207/00
HUMAN NECESSITIES
A61M2005/2477
HUMAN NECESSITIES
F16F1/32
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
International classification
A61M5/20
HUMAN NECESSITIES
B21D53/22
PERFORMING OPERATIONS; TRANSPORTING
Abstract
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.
Claims
1. A medical injection device comprising: a housing having a proximal end, a distal end, and 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 of the brake member; a cartridge received within the 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 away from the proximal surface of the main body, the load spring washer received within the interior of the housing and positioned between the brake member and the cartridge holder such that, when the medical injection device is assembled, the one or more protrusions abuts the brake member and the distal surface abuts the cartridge and/or the cartridge holder; an injection needle in fluid communication with the cartridge and arranged at a distal end of the housing; and an actuation member arranged at the proximal end of the housing, the actuation member configured to actuate the medical injection device to deliver the composition through the injection needle.
2. The medical injection device of claim 1, wherein a cross-sectional profile of the one or more protrusions of the load spring washer, taken along a plane extending between the proximal surface and the distal surface, comprises a parallelogram.
3. The medical injection device of claim 1, wherein a cross-sectional profile of the one or more protrusions of the load spring washer, taken along a plane extending between the proximal surface and the distal surface, comprises a cylindrical shape.
4. The medical injection device of claim 3, wherein the cylindrical shape defines a hollow interior.
5. The medical injection device of claim 4, wherein the hollow interior is filled with a gas.
6. The medical injection device of claim 4, wherein the hollow interior comprises a vacuum.
7. The medical injection device of claim 1, wherein a cross-sectional profile of the one or more protrusions of the load spring washer, taken along a plane extending between the proximal surface and the distal surface, comprises a rhomboid.
8. The medical injection device of claim 1, wherein a cross-sectional profile of the one or more protrusions of the load spring washer, taken along a plane extending between the proximal surface and the distal surface, comprises an s-shape.
9. The medical injection device of claim 1, wherein a cross-sectional profile of the one or more protrusions of the load spring washer, taken along a plane extending between the proximal surface and the distal surface, comprises an 1-shape.
10. The medical injection device of claim 1, wherein the main body of the load spring washer comprises a plurality of rings.
11. The medical injection device of claim 10, wherein the plurality of rings comprise concentric circles, with a gap between each of the concentric circles.
12. The medical injection device of claim 11, wherein at least one of the concentric circles has a width that is greater than a width of another of the concentric circles.
13. The medical injection device of claim 10, wherein a cross-sectional profile of the one or more protrusions of the load spring washer, taken along a plane extending between the proximal surface and the distal surface, comprises a u-shape, wherein the u-shape comprises: a first arm connected to a first of the plurality of rings of the main body and a second arm connected to a second of the plurality of rings of the main body, both the first arm and the second arm extending parallel to a longitudinal axis defined by the proximal surface and the distal surface 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 surface and the distal surface of the main body.
14. The medical injection device of claim 10, wherein the one or more protrusions of the load spring washer comprise an arch comprising: a first arm connected to a first of the plurality of rings of the main body and a second arm connected to a second of the plurality of rings of the main body, both the first arm and the second arm extending parallel to a longitudinal axis defined by the proximal surface and the distal surface of the main body; and a curved portion connected to the first arm and the second arm.
15. The medical injection device of claim 1, wherein the one or more protrusions of the load spring washer comprise a frustoconical portion.
16. The medical injection device of claim 1, wherein the load spring washer comprises an elastomeric material.
17. The medical injection device of claim 16, wherein the load spring washer comprises an ethylene propylene diene monomer rubber.
18. The medical injection device of claim 16, wherein the load spring washer has a Shore A hardness of 20-40.
19. A load spring washer configured for biasing an injection sub-assembly of a medical injection device, comprising: a circular main body having a proximal surface and a distal surface, the distal surface configured to abut a cartridge holder and/or cartridge of a medical injection device; and one or more protrusions extending proximally away from the proximal surface of the main body, wherein the one or more protrusions are configured to abut a brake member of a medical injection device.
20. The load spring washer of claim 19, wherein the load spring washer comprises an elastomeric material having a Shore A hardness of 20-40.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DESCRIPTION OF THE INVENTION
[0059] The use of numerical values in the various ranges specified in this application, unless expressly indicated otherwise, are stated as approximations as though the minimum and maximum values within the stated ranges are both preceded by the word about. As used herein, the term about means the stated value 10%. In this manner, slight variations above and below the stated ranges can be used to achieve substantially the same results as values within the ranges. Also, unless indicated otherwise, the disclosure of these ranges is intended as a continuous range including every value between the minimum and maximum values. For definitions provided herein, those definitions refer to word forms, cognates and grammatical variants of those words or phrases.
[0060] The figures accompanying this application are representative in nature, and should not be construed as implying any particular scale or directionality, unless otherwise indicated. For purposes of the description hereinafter, the terms upper, lower, right, left, vertical, horizontal, top, bottom, lateral, longitudinal and derivatives thereof shall relate to the invention as it is oriented in the drawing figures. However, it is to be understood that the invention may assume various alternative variations and step sequences, except where expressly specified to the contrary. Hence, specific dimensions and other physical characteristics related to the embodiments disclosed herein are not to be considered as limiting.
[0061] Provided herein is a load spring washer for use as a replacement for a spring in a medical device. A spring washer, as is known to those of skill in the art, is a washer having axial flexibility. As used herein, the spring aspect of a spring washer for use in a medical device is a washer that has axial flexibility by virtue of the material from which the washer is formed (e.g., compressibility/expandability derived from the elastomeric nature of materials), by virtue of a shape or form of the washer, and combinations thereof. In non-limiting embodiments or aspects, the load spring washer is formed of an elastomeric material. In non-limiting embodiments or aspects, the elastomeric material is a highly resilient elastomeric material. In non-limiting embodiments or aspects, the load spring washer is formed of a 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), chlorosulphonated polyethylene (CSM), ethylene-vinyl acetate copolymer (EVA), styrene-isoprene rubber (SIR), thermoplastic elastomers, and/or natural rubbers.
[0062] In non-limiting embodiments or aspects, the load spring washer is formed of a elastomeric copolymer, including, without limitation, thermoplastic elastomers, thermoplastic vulcanizates, styrene copolymers such as styrene-butadiene (SBR or SBS) copolymers, styrene-isoprene (SIS) block polymers or styrene-isoprene/butadiene (SIBS), in which the content of styrene in the styrene block copolymer ranges from about 10% to about 70%, and preferably from about 20% to about 50%. The elastomer composition can include, without limitation, antioxidants and/or inorganic reinforcing agents to preserve the stability of the elastomer composition, a vulcanizing agent, a vulcanizing accelerator, a vulcanizing activator, a processing aid, a filler, etc. to maintain and improve the physical properties and heat resistance of the rubber material.
[0063] In non-limiting embodiments or aspects, the load spring washer is formed of a material having a Shore A value of 20-40 optionally 30-40, all values and subranges therebetween inclusive. In non-limiting embodiments or aspects, the load spring washer is formed of a material comprising an ethylene propylene diene monomer (EPDM) rubber. In non-limiting embodiments or aspects, the load spring washer is formed of a material comprising an EPDM rubber, and various fillers/additives. In non-limiting embodiments or aspects, the load spring washer is formed of an ultra-high molecular weight EPDM rubber (e.g., KELTAN 9565Q), various fillers (e.g., MISTRON Vapor), mineral oil, zinc oxide, stearic acid, antioxidant(s) (e.g., SONGNOX 1076), curing accelerator(s) (e.g., TBzTD), vulcanizing agent(s) (e.g., VULTAC 710), and sulfur (such as a wettable sulfur).
[0064] In non-limiting embodiments or aspects, the load spring washer is formed of a foam. In non-limiting embodiments or aspects, the load spring washer is formed of a mixture of materials, for example, and without limitation, a metal and/or polymer, together with a rubber and/or foam. For example, and without limitation, a load spring washer as described below can include a main body that is a metal, a polymer, or a mix, together with a protrusion that is formed of an elastomeric material, such as a rubber, foam, or elastomeric polymer.
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[0076] Arm 225 can include portion 215 extending outward from an outer diameter of main body 205, and a portion 220 extending substantially perpendicular to portion 215. Arm 225 further includes portion 230 extending substantially perpendicular to portion 220. In non-limiting embodiments or aspects, portion 230 is substantially parallel to portion 215.
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[0080] Also provided herein is a medical injection device including a load spring washer as described above. Such devices, such as injection pens, are described in, for example and without limitation, U.S. Pat. No. 9,421,334, which is incorporated herein by reference in its entirety. With reference to
[0081] Injection pen 51 includes a push button 3, provided at a proximal end, closest to a user and farthest from a needlf18Ae 56, of the pen upper body 1. The push button 3 can include an annular bead or rim 57 that engages with a corresponding annular groove (not shown) provided on the internal surface of the dose set knob 2. The annular rim and groove connection can be a friction fit that maintains the push button 3 in a biased position on the dose set knob 2 under the force of a button spring 10, but allows the push button 3 to be pushed into the dose set knob 2 for injecting a set dose. The interior of the push button 3 can accommodate a setback bearing insert 8 that rests on an internal surface at a proximal end of a setback member or driver 9. The push button 3 can be designed to rotate freely on the setback bearing insert 8.
[0082] The setback member or driver 9 can be a cylindrical member, coaxial with and surrounded by the dose set knob 2. The setback member 9 can be provided co-axially around a brake tower 5 that is axially and rotatably fixed to the pen upper body 1. The brake tower 5 co-axially surrounds a piston rod 6. The piston rod 6 includes a set of keys 62 that engage a slot (not shown) internal to 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) provided on the interior surface thereof. The piston rod 6 can co-axially surround a lead screw 4 that includes a series of threads 42 at least at its distal end. The lead screw threads 42 can be configured to be in threaded engagement with the internal threads (not shown) provided on the interior of 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 press on a stopper 16 provided inside the cartridge 15 to expel a dose of medication.
[0083] With reference to the present disclosure, injection pen 51 includes load spring washer 11, provided between a 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 reduce rattling and improve needle 56 penetration into the cartridge 15 before priming.
Example
[0084] Load spring washers were formed out of a highly resilient elastomeric material including the following ingredients:
TABLE-US-00001 TABLE 1 Density Formulation Batch Batch Ingredient PHR (g/ml) Volume (ml) Weight (g) Weight (lbs) KELTAN 9565Q 150 (equivalent to 100 0.87 172.4 1719 3.8 PHR of the polymer) MINSTRON Vapor 37 2.80 13.2 424 0.9 Mineral Oil 10 0.87 11.5 115 0.3 Zinc Oxide 5 5.61 0.9 57 0.1 Stearic Acid 1 0.94 1.1 11 0.0 SONGNOX 1076 2 0.90 2.2 23 0.1 TBzTD 2.5 1.40 1.8 29 0.1 VULTAC710 6.5 0.80 8.1 75 0.2 Sulfur/80 1 2.07 0.5 11 0.0
[0085] The above material was utilized to manufacture load spring washers of various orientations/shapes, as shown in
TABLE-US-00002 TABLE 2 Compressive Load Area Loading Area Unloading Sample at Max Load (N) (mJ) (mJ) Ring (Cycle 1) 21.070760 12.11671 Ring (Cycle 2) 27.06701 16.34493 Ring (Cycle 3) 28.86325 18.21729 Ring (Cycle 4) 28.57111 18.33210 H-Shape (Cycle 1) 39.58269 22.04388 19.03213 H-Shape (Cycle 2) 54.70945 34.01410 H-Shape (Cycle 3) 55.12173 33.77259 Star-Shape 7 (Cycle 1) 34.50593 18.54269 Star-Shape 7 (Cycle 2) 36.79152 19.66360 Star-Shape 6 (Cycle 1) 23.41913 10.59406 9.08724 Star-Shape 6 (Cycle 2) 37.52744 19.25595 Star Shape 5 (Cycle 1) 20.81262 8.90632 Star Shape 5 (Cycle 2) 35.15383 16.75382 Star-Shape 8 (Cycle 1) 24.83673 10.29839 Star-Shape 8 (Cycle 2) 46.02887 23.23951 Mean 34.31326 18.80640 14.05969 Standard Deviation 11.00674 7.46342 7.03210
TABLE-US-00003 TABLE 3 Compressive Load Compressive Load Area Loading- Sample at 0.06 mm (N) at 0.1 mm (N) Unloading Ring (Cycle 1) 0.11229 0.12129 Ring (Cycle 2) 0.12245 0.14109 Ring (Cycle 3) 0.14285 0.18381 Ring (Cycle 4) 0.14561 0.20023 H-Shape (Cycle 1) 0.14093 0.16526 22.02485 H-Shape (Cycle 2) 0.37301 0.69075 H-Shape (Cycle 3) 0.38491 0.72202 Star-Shape 7 (Cycle 1) 0.21051 0.33861 Star-Shape 7 (Cycle 2) 0.26773 0.38741 Star-Shape 6 (Cycle 1) 0.12589 0.14490 10.58497 Star-Shape 6 (Cycle 2) 0.18198 0.27805 Star Shape 5 (Cycle 1) 0.12710 0.16690 Star Shape 5 (Cycle 2) 0.14909 0.18438 Star-Shape 8 (Cycle 1) 0.13538 0.15526 Star-Shape 8 (Cycle 2) 0.16724 0.22068 Mean 0.18580 0.27358 16.30491 Standard Deviation 0.08791 0.19092 8.08921
[0086] In addition, data (compressive load vs. compressive extension) from the above samples is presented in
[0087] In addition, 19 more samples were produced from a silicone-based rubber material durometer Shore A 35 where the silicone rubber rings were cut using a 14 mm outer diameter cutting die and the internal diameter was subsequently punched with a 10 mm (samples 5, 6, and 7 on Tables 4 and 5) or 12 mm (otherwise) cutting dies. The rings were cut from ASTM rubber plates 6.5 L6.5 W and 1.8-2.0 mm thick. All samples in Tables 4 and 5 are the same test but with the forces specified at different compression distance. The maximum compression extension was 1.5 mm
[0088] Tables 6 and 7 are the same test but with the forces specified at different compression distance. The maximum compression extension was 1.5 mm.
[0089] All samples for Tables 4 and 5, 6 and 7 were made in the same way, by punching rings from a rubber slab, with dimensions as provided in
TABLE-US-00004 TABLE 4 Compressive Load Area Loading Sample at Max Load (N) (mJ) 1 93.88897 0.18077 2 10.45748 0.03745 3 16.52684 0.04315 4 10.11987 0.03775 5 95.78949 0.12344 6 83.01142 0.06146 7 84.12963 0.06087 8 47.08079 0.04381 9 60.84618 0.05374 10 51.33612 0.04990 11 34.94950 0.04530 12 34.81499 0.03465 13 56.72254 0.03722 14 62.92496 0.03778 15 50.73323 0.06551 16 46.06429 0.07922 17 34.00679 0.08139 18 27.50728 0.05415 19 24.93059 0.03774 Mean 48.72847 0.06133 Standard Deviation 26.58819 0.03616
TABLE-US-00005 TABLE 5 Compressive Load Compressive Load Sample at 0.06 mm (N) at 0.1 mm (N) 1 2.05477 4.63418 2 0.46023 0.70048 3 0.507741 0.75857 4 0.44663 0.69240 5 1.43243 3.13971 6 0.72140 1.35426 7 0.72024 1.31258 8 0.50808 0.95933 9 0.61815 1.16032 10 0.58744 1.06286 11 0.53254 0.92751 12 0.41074 0.63211 13 0.43921 0.68218 14 0.44336 0.71033 15 0.71995 1.71387 16 0.91263 1.96137 17 0.95401 1.95577 18 0.61690 1.30184 19 0.41083 0.88197 Mean 0.71038 1.39693 Standard Deviation 0.41041 1.00186
[0090] Lastly, 14 additional samples were produced with dimensions as provided in
TABLE-US-00006 TABLE 6 Compressive Load Area Loading Sample at Max Load (N) (mJ) 1 24.69491 0.04113 2 37.05007 0.04490 3 33.01292 0.05191 4 37.35841 0.02748 5 34.43204 0.02544 6 47.63247 0.04586 7 41.19097 0.01437 8 41.629663 0.08237 9 21.41265 0.10109 10 17.45964 0.04048 11 43.15011 0.05729 12 38.22097 0.06700 13 30.09437 0.07706 14 26.62738 0.05819 Mean 33.85475 0.05247 Standard Deviation 8.80111 0.02371
TABLE-US-00007 TABLE 7 Compressive Load Compressive Load Sample at 0.06 mm (N) at 0.1 mm (N) 1 0.45692 1.02958 2 0.48036 1.30489 3 0.56545 1.37173 4 0.30807 0.57717 5 0.28093 0.54226 6 0.50611 1.24077 7 0.14521 0.31382 8 0.96456 2.14320 9 1.18252 2.40098 10 0.43440 1.05093 11 0.65224 1.42832 12 0.76420 1.74184 13 0.85138 2.07813 14 0.66296 1.38261 Mean 0.58966 1.32902 Standard Deviation 0.28198 0.61696
[0091] The rings tested in Table 4 and 5 and 6 and 8 performed as expected showing different orders of buckling and limiting the developed forces for compression extension up to 1.5 mm below. The variations on the max compressions forces is due to either the width of the ring 1.5 mm on samples 5, 6, and 7 on Tables 4 and 5 or the variation on the punching and centering of the dies during the ring manufacturing. In fact, the variability of the process created asymmetric cross sections of the rings which facilitate the buckling concept approach.
[0092] Although the devices have been described in detail for the purpose of illustration based on what is currently considered to be the most practical and preferred embodiments, it is to be understood that such detail is solely for that purpose and that the systems and methods are not limited to the disclosed embodiments, but on the contrary, is intended to cover modifications and equivalent arrangements that are within the spirit and scope of the appended claims. For example, it is to be understood that the present 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.