WO2026006169A1 - Ratchet mechanism, system and method comprising the same including single ratchet with offset driving pawls - Google Patents

Abstract

Present disclosure provides systems and combinations of features or components comprising ratchet gear having an outer circumferential surface with ratchet teeth with a spacing between adjacent to the ratchet teeth, a driving pawl configured to individually contact the ratchet teeth to advance the ratchet gear by an advance increment, another driving pawl configured to individually contact the ratchet teeth to advance the ratchet gear by another advance increment, and a driver operatively connected to the driving pawls, wherein one of driving pawls can be offset from the other driving pawl by an offset increment, and the driver can cause one of the driving pawl to push on a tooth of the ratchet gear teeth to advance the ratchet gear by one advance increment, and the other driving pawl to push on the tooth of the ratchet gear teeth to advance the ratchet gear by the another advance increment.

Description

RATCHET MECHANISM, SYSTEM AND METHOD COMPRISING THE SAME

INCLUDING SINGLE RATCHET WITH OFFSET DRIVING PAWLS

[0001] This application claims priority from U.S. Provisional Patent Application No. 63/663,156 filed June 23, 2024, the contents of which (including all attachments filed therewith) are hereby incorporated by reference in their entirety.

Background

[0002] Generally, exemplary embodiments of the present disclosure relate to the fields of driving mechanisms for medication delivery devices. More specifically, exemplary embodiments of the present disclosure relate to medication delivery devices where a stopper or plunger is advanced through a reservoir to dispense medication from the reservoir by use of a driving mechanism including a ratchet.

[0003] In the example of medical applicati ons, a patch pump is an integrated device that facilitates infusion therapy for diabetic patients. A patch pump combines most or all of the fluidic components, including the fluid reservoir, pumping mechanism and mechanism for automatically inserting the cannula, in a single housing which is adhesively attached to an infusion site on the patient’s skin, and does not require the use of a separate infusion or tubing set. A patch pump containing insulin adheres to the skin and delivers the insulin over a period of time via an integrated subcutaneous cannula. Some patch pumps may be configured to include wireless communication with a separate controller device, while others are completely self-contained. Such devices are replaced on a frequent basis, such as every three days, particularly when the insulin reservoir is exhausted.

[0004] As patch pumps are designed to be a self-contained unit that is worn by the diabetic patient, it is preferable to be as small as possible so that it does not interfere with the activities of the user. Thus, in order to minimize discomfort to the user, it would be preferable to minimize the overall size of the patch pump. Conventional patch pumps or a syringe-type devices typically include a driving mechanism with a single advancing lead screw inside medium or fluid reservoir or chamber to push, advance, or otherwise apply force on the plunger in order to dispense the medium or fluid out of the chamber.

[0005] An example of a patch pump having single advancing lead screw features is disclosed in WO2022/261100, published December 15, 2022, the entire disclosure of which is incorporated herein by reference. As illustrated in FIGs. 1A - 1C, a wearable disposable patch pump 100 can be configured to include a base 102, outer housing 104, and an insertion mechanism 106. FIG. 1C illustrates a top view, of pump 100 without the outer housing or cover 104, and diagrammatically shows at least some of the various components that can be configured on base 102 of a pump 100 including a pumping mechanism 200 having a motor 202 operatively connected to lead screw 204 by gears including reduction gears 206 and lead screw gear 208 configured to rotate lead screw 204. A plunger assembly 210 is disposed inside barrel 212 such that plunger 210 translates or moves axially with respect to barrel 212 due to rotation of lead screw 204 whereby fluid can be dispensed by rotating the motor 202 forward driving the plunger 210 to move axially with respect to barrel 212 away from proximal end 213 and toward distal end 215 of barrel 212 forcing fluid out of the barrel outlet 107.

[0006] Other mechanisms for advancing a plunger in a barrel described in WO2022/261100 include a linkage mechanism, illustrated in FIG. ID, and a collapsible drive mechanism, illustrated in FIG. IE. As shown in FIG. ID, a pumping device 900, which can be deployed for example in a pump 100, can comprise a plunger 910 disposed in barrel 912, such that plunger 910 can be advanced axially toward and away from distal end 915 of barrel 912 by a two linkage mechanism 904 driven through appropriate gearing 920 by a motor (not shown) for example operatively connected at 921. As shown in FIG. IE, a collapsible drive mechanism 1200, which can be deployed for example in a pump 100, can include a linkage mechanism 1304 connected to a plunger 1210 disposed in barrel 1212 and driven by a motor (not shown) for example operatively connected at 1207. The linkage mechanism can comprise a single linkage or a set of two full linkages 1305 and 1306 and two half linkages 1307 and 1208, where distal ends of half linkages 1307 and 1308 can be joined at, or pivotally coupled to, plunger 1210, for example at proximal end 1415 of plunger 1210, for example via a loose pin 1420. Proximal ends of half linkages 1307 and 1308 can be joined at, or pivotally coupled to, distal ends of respective full linkages 1305 and 1306, for example via respective loose pins 1421 and 1422. Full linkages 1305 and 1306 crisscross and can be joined, or pivotally coupled, essentially at the centers thereof, for example by means of a loose pin 1423. Proximal ends of full linkages 1305 and 1306 are joined at, or pivotally coupled to, the driveshaft 1207 at opposing left 1302 and right 1301 hand female screw threads, respectively, for example by means of respective loose pins 1425 and 1424.

[0007] Yet other mechanisms for advancing a plunger in a barrel of a patch pump can include a ratchet. Referring to FIG. 2, components of a conventional ratchet include a ratchet wheel or gear 1 rationally 11 mounted on a spindle 2, a driving pawn 3 springmounted 4 on an movable/ driven 55 arm 5, and a spring-mounted 6 locking pawl 7. Typically, the purpose of a ratchet is to allow rotation in one direction 11 and/or to increment rotation resolution finely. When preventing back drive (by a locking pawl 7) or incrementing (by a driving pawl 3), a typical ratchet’s rotation resolution is limited by the number of teeth 8 on the ratchet wheel 1 that interact with driving pawl 3 and locking pawl 7. When designed to prevent back drive, ratchet wheel 1 will be driven into the nearest tooth 8 and be stopped from rotating further. If designed to increment, ratchet wheel 1 will be rotationally incremented one tooth 8 at a time.

[0008] Referring to FIGs. 3 A, 3B, 3C, 3D, and 4, as described in U.S. Provisional Application No. 63/572,707, the entire disclosure of which is incorporated herein by reference, a patch pump structure 2000 can comprise a mechanism 2010 where a cam 2006, driven by a motor 2002 connected to a power source 2014, and a ratchet 2008 can be configured to rotate a lead screw 2004 to drive a plunger disposed in a barrel 2012. As illustrated in FIG. 3B, a vertical plate 2020, such as a formed baseplate (with various alignment features), can be provided in addition to, or integral with, structure 2000 for accommodating a ratchet gear 2008, a cam, for example a single-part dual cam driver, 2006 actuated by a bi-directional motor 2002, a metal spring clip 2022 (for example a single clip with two arms, or two one-arm clips), a clip bias pin 2024, a cam alignment pin (not visible), one or more stopper pins 2028, 2028A can be used to constrain and/or guide the aforementioned components, and a stopper pin 2028 A can be used to hold the metal spring clip 2022 against the alignment features 2021 of the formed baseplate 2020.

[0009] As illustrated in FIGs. 3C and 3D, ratchet 2008 can be configured as a ratchet gear 3008 comprising two sets of gear teeth 3032, 3034 that can be split via a central circular flange 3036 which extends past the maximum diameter of the gear teeth and separates and guides the two arms 3022, and 3024 of the metal spring clip, such as a clip 2022. Cam 2006 can be configured as a single-part dual cam driver 4006 that can be composed of two cam surfaces 4010, 4012 which are axially aligned but symmetrically mirrored. As illustrated in FIG 4, various components of mechanism 2010, can be configured on a base 3002 of a pump 3000 were a distal end of barrel 2012 may include an endcap 3070 to facilitate connection of barrel 2012 to an insertion mechanism, such as a mechanism 106, for example via port or tube 3072, to dispense medium or fluid out of barrel 2012 by displacement of plunger 2005. Endcap 3070 can also be configured to facilitate connection of barrel 2012 to fill port or inlet 3200, for example via a tube such as tube 3074, to fill barrel 2012 with medium or fluid. In an exemplary implementation, motor 2002 can be controlled by a microprocessor having a memory, such as a microchip mounted on a PCB 300, or other controlling method.

[OO1O] In order to further minimize the size of the patch pump and possibly improve its performance and/or reliability, a number and/or function of its constituent parts, such as those of the driving mechanisms, can be optimized as much as possible without compromising the accuracy and reliability of device or its feature set.

[0011] For example, in a patch pump that uses a ratchet, to get finer rotational resolution more teeth per revolution can be added, either by making the teeth smaller or the diameter of the ratchet wheel/gear bigger. However, when trying to incorporate a ratchet into a device such as a patch pump, this can lead to a design contradiction: a ratchet mechanism needs to have as many increments as possible (large number of teeth), but be as small as possible (smallest ratchet wheel diameter) and retain manufacturability (individual teeth cannot be too small). Accordingly, there is a need to address such contradiction, which may not be solved by known ratchet mechanism designs.

Summary of Disclosure

[0012] The matters exemplified in this description are provided to assist in a comprehensive understanding of exemplary embodiments of the disclosure. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the disclosure. Also, descriptions of well-known functions and constructions are omitted for clarity and conciseness.

[0013] As would be readily appreciated by skilled artisans in the relevant art, while descriptive terms such as “medium,” “medicament,” “stopper,” “plunger,” “arm,” “syringe,” “motor,” “pawl,” “ratchet,” “gear,” “teeth,”, “flange,” “cam,” “dwell,” “wall,” “top,” “side,” “bottom,” “upper,” “lower,” “proximal,” “distal,” “container” “reservoir,” “chamber,” “driver,” “offset,” “wheel,” and others are used throughout this specification to facilitate understanding, it is not intended to limit any components that can be used in combinations or individually to implement various aspects of the embodiments of the present disclosure.

[0014] Exemplary’ embodiments of the present disclosure provide devices, systems, and components where a single ratchet can be rotate/pushed/advanced pushed by multiple offset driving pawls such that the increment size of rotation/push/advance of the ratchet can be decreased by increasing the number of the offset driving pawls.

[0015] Exemplary’ embodiments of the present disclosure provide a combination of features and^zor components comprising: a ratchet gear having an outer circumferential surface comprising a plurality’ of ratchet teeth with a spacing between adjacent to the ratchet teeth; a first driving pawl configured to individually contact the ratchet teeth to advance the ratchet gear by a first advance increment; a second driving pawl configured to individually contact the ratchet teeth to advance the ratchet gear by a second advance increment; and a driver operatively connected to the first driving pawl and the second driving pawl, wherein the first driving pawl can be offset from the second driving pawl by a first pawl offset increment, and the driver can cause: the first driving pawl to push on a tooth of the ratchet gear teeth to advance the ratchet gear by the first advance increment; and the second driving pawl to push on the tooth of the ratchet gear teeth to advance the ratchet gear by the second advance increment after the advance by the first advance increment. [0016] Exemplary implementations of embodiments of the present disclosure provide a combination wherein the first pawl offset increment is less than the spacing between the adjacent of the ratchet teeth.

[0017] Exemplary implementations of embodiments of the present disc losure provide a combination comprising a plurality of pawls comprising the first driving pawl and the second driving pawl, wherein the ratchet gear can be advanced with respect to the tooth by a plurality of advance increments comprising the first advance increment and the second advance increment, and a number of the advance increments of the ratchet gear with respect to the tooth can be increased or decreased based on a number and configuration of the pawls with respect to the tooth of the ratchet gear.

[0018] Exemplary implementations of embodiments of the present disclosure provide a combination, wherein a driver can oscillate within a region greater than the first pawl offset increment and less than the spacing between the adjacent of the ratchet teeth.

[0019] Exemplary implementations of embodiments of the present disclosure provide a combination, wherein the ratchet gear can be advanced by the first pawl offset increment with each reciprocal motion of the driver.

[0020] Exemplary implementations of embodiments of the present disc losure provide a combination further comprising a metal spring clip, wherein a first arm of the metal spring can comprise the first driving pawl, and a second arm of the metal spring can comprise the second driving pawl. [0021] Exemplary implementations of embodiments of the present disclosure provide a combination, wherein the cam can comprise a single outer surface for advancing the first driving pawl and the second driving pawl.

[0022] Exemplary implementations of embodiments of the present disc losure provide a combination further comprising: a third driving pawl configured to individually contact the ratchet teeth to advance the ratchet gear by a third advance increment; and a fourth driving pawl configured to individually contact the ratchet teeth to advance the ratchet gear by a fourth advance increment, wherein the driver can be operatively connected to the third driving pawl and the fourth driving pawl, the second driving pawl can be offset from the third driving pawl by a second pawl offset increment, the third driving pawl can be offset from the fourth driving pawl by a third pawl offset increment, and the driver can cause: the third driving pawl to push on a tooth of the ratchet gear teeth to advance the ratchet gear by the third advance increment after the advance by the second advance increment; and the fourth driving pawl to push on the tooth of the ratchet gear teeth to advance the ratchet gear by the fourth advance increment after the advance by the third advance increment.

[0023] Exemplary implementations of embodiments of the present disclosure provide, wherein a sum of the first pawl offset increment, the second pawl offset increment, and the third pawl offset increment can be less than the spacing between the adjacent of the ratchet teeth. [0024] Exemplary implementations of embodiments of the present disclosure provide, comprising a plurality of pawls comprising the first driving pawl, the second driving pawl, the third driving pawl and the fourth driving pawl, wherein the ratchet gear can be advanced with respect to the tooth by a plurality of advance increments comprising the first advance increment, the second advance increment, the third advance increment, and the fourth advance increment, and a number of the advance increments of the ratchet gear with respect to the tooth can be increased or decreased based on a number and configuration of the pawls with respect to the tooth of the ratchet gear.

[0025] Exemplary’ implementations of embodiments of the present disclosure provide, wherein a driver can oscillate within a region greater than the first pawl offset increment, the second pawl offset increment, or the third pawl offset increment, and less than the spacing between the adjacent of the ratchet teeth.

[0026] Exemplary implementations of embodiments of the present disclosure provide, wherein the ratchet gear can be advanced by the first pawl offset increment, the second pawl offset increment, or the third pawl offset increment, with each reciprocal motion of the driver.

[0027] Exemplary’ implementations of embodiments of the present disclosure provide, further comprising a metal spring clip, wherein a first arm of the metal spring can comprise the first driving pawl, a second arm of the metal spring can comprise the second driving pawl, a third arm of the metal spring can comprise the third driving pawl, and a fourth arm of the metal spring can comprise the fourth driving pawl. [0028] Exemplary implementations of embodiments of the present disclosure provide. wherein the cam can comprise a single outer surface for advancing the first driving pawl, the second driving pawl, the third driving pawl and the fourth driving pawl.

[0029] Exemplary implementations of the exemplary embodiments of the present disclosure provide system components for a drug delivery device, such as a patch pump, including for example in a pumping mechanism that, for example and without limitation, can be functional in a wider range of temperature settings, for example at higher temperatures, and can allow for a more compact design of various syringe driven pumps.

[0030] Further exemplary' implementations of the exemplary embodiments of the present disclosure provide combinations of various feature of a drive mechanism including a ratcheting mechanism actuated using, for example a bi-directional, motor paired, for example, with a leadscrew driven syringe pump or a linkage driven syringe pump, for advancing a plunger to dispense the medium or fluid in a drug delivery device.

[0031] According to exemplary embodiments of the present disclosure, a system can include a syringe-style drug container, reservoir, or chamber containing a medium or fluid which can be dispensed by advancing a plunger disposed inside the container facing, or in contact with, or proximal to, the medium inside the container, and a ratchet mechanism, for example disposed outside the container, driven by a motor to advance the plunger to dispense the medium or fluid out of the container.

[0032] According to exemplary embodiments of the present disclosure, certain space savings and/or a more compact design of various syringe driven pumps can, but is not required to, be achieved by utilizing exemplary implementations of a mechanical drive mechanism that has, for example and without limitation, a parallel axial alignment between a ratchet/lead screw and a motor driver. For example, in such an implementation, a motor may be arrange to take up the length of space adjacent to the syringe pump reservoir.

[0033] In exemplary implementations of embodiments of the present disclosure, in example proposed design embodiment only a ratchet gear can be configured to contribute directly to functional increment tolerancing.

[0034] Further, in exemplary implementations of the embodiments of present disclosure, a cam driven index drive mechanism can be paired with a leadscrew driven syringe pump, where the cam driven index drive mechanism can offer, for example and without limitation, a safety feature when used in conjunction with a leadscrew driven syringe pump in that the mechanism can mitigate the possibility of a runaway fluid infusion in the event of an error state in which the driving motor is left miming.

[0035] In yet further exemplary implementations of embodiments of the present disclosure, a ratchet advancement can be facilitated using a metal spring clip comprising a plurality of offset pawls to rotate, push, or advance a ratchet wheel.

[0036] In yet further exemplary implementations of embodiments of the present disclosure, a cam follower and an element that puts tension on the cam follower can be implemented as a single component. [0037] In exemplary implementations of embodiments of the present disclosure, conversion of rotational to linear motion can be achieved using a bi-directional motor.

[0038] In exemplary implementations of embodiments of the present disclosure, double acting spring arms can be used to replace a ratchet locking pawl.

[0039] Exemplary implementations of embodiments of the present disclosure can utilize a single ratchet wheel with gear teeth.

[0040] Exemplary implementations of embodiments of the present disclosure can utilize variable thickness metal spring clip.

[0041] Exemplary implementations of embodiments of the present disclosure can utilize three or more offset pawls that are not equally offset or spaced with respect to each other.

[0042] Exemplary implementations of embodiments of the present disclosure can utilize offset pawls that are equally spaced or offset.

[0043] In exemplary implementations of embodiments of the present disclosure, a leadscrew can be configures as either fused to a ratchet or interfaced as two separate components.

Brief Description of Drawings

[0044] Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views, embodiments of the present disclosure are described as follows. [0045] FIGs. 1A and IB are examples of perspective views of an exterior of a device according to exemplary embodiment of the present disclosure.

[0046] FIGs. 1C, ID and IE are examples of perspective views of components of device configurations that can be optionally implemented with various configurations of exemplary embodiment of the present disclosure.

[0047] FIG. 2 diagrammatically illustrates a conventional ratchet design.

[0048] FIG. 3A illustrates a top view of a combination of system components of a device that can implement, or can be modified to implement, certain features of exemplary embodiments of the disclosure.

[0049] FIGs. 3B, 3C and 3D diagrammatically illustrate views of combinations of system components device that can implement, or can be modified to implement, certain features of exemplary embodiment of the present disclosure.

[0050] FIG. 4 illustrates another top view of a combination of system components of a device that can implement or can be modified to implement, certain features of exemplary embodiments of the disclosure

[0051] FIGs. 5A and 5B diagrammatically and comparatively illustrate exemplary' features and non-limiting implementation of disclosed exemplary embodiments.

[0052] FIGs. 6A and 6B illustrate in more detail examples of various configurations of a components, such as in the example of FIG. 5B, that can be implemented in a device and/or system according to the exemplary embodiments of the disclosure. [0053] FIGs. 7 A and 7B diagrammatically and comparatively illustrate exemplary' features and non-limiting implementation of disclosed exemplary embodiments.

[0054] FIGs. 8A and 8B diagrammatically illustrates exemplary features and nonlimiting implementation of disclosed exemplary embodiments, such as illustrated in the example of FIG. 5B, as implemented in an example configuration such as illustrated in the examples of FIGs. 3A-3D and 4.

Detailed Description of Disclosure

[0055] Exemplary embodiments of the present disclosure provide systems, devices, components, and methodologies comprising, without limitation, various design of a ratcheting mechanism, for example driven by a back-and-forth rotation of a motor such as a bi-directional motor.

[0056] Referring to FIGs. 5B, 6A and 6B, certain component configurations according to an exemplary embodiments of the present disclosure can be implements for example and without limitation in a wearable disposable patch pump, such as a pump 100 or a pump 3000, that utilizes a ratchet mechanism, such as a mechanism 2010, or in any device that utilizes a ratchet to achieve fine rotational resolution. As diagrammaticalty shown in FIGs 5B, 6A and 6B in exemplary implementations of disclosed embodiments, a ratchet mechanism 5100 comprises a single ratchet gear 5000, for example a ratchet wheel, with teeth 5018 on its outer, for example circumferential, surface, that can be pushed/advanced/rotated 5002 by multiple, for example two, offset driving pawls (first pawl 5004 and second pawl 5006) driven by, for example reciprocating/oscillating 5009, driver 5008, rather than being driven/advanced/rotated 5003 by a single driving pawl 5001 as shown in FIG. 5 A. For example and without limitation, driver 5008 can comprise, or be operatively coupled to, a motor, for example a bi-directional motor.

[0057] In an exemplary implementation, first pawl 5004 and second pawl 5006 can be offset such that when driver 5008 pulls back by about a 3/4 tooth 5018 rotation of ratchet wheel/gear 5000, only first pawl 5004 will fall and advance ratchet wheeVgear 5000. On next pull back, only second pawl 5006 will fall so as to advance ratchet wheel/gear 5000. According to exemplary implementations of disclosed embodiments, the number of increments by which ratchet wheel/gear can be advanced per tooth can be increased or decreased based on the number and configuration of pawls, such as a first pawl 5004 and a second pawl 5006, with respect to ratchet gear teeth 5018, for the example by increasing or decreasing the number of pawls within the space between two adjacent teeth 5018 of a ratchet gear 5000. Such that, for example, a configuration comprising four pawls can have four increments per ratchet tooth. The size of each increment can be controlled by the offset between the pawls. Advantageously, exemplary implementations of disclosed embodiments, do not increase configuration size because multiple pawls can remain connected 5020 and the number of ratchet gear teeth 5018 is not increased to achieve finer rotational or linear resolution of gear 5000.

[0058] Referring further to example diagram of FIGs. 6 A and 6B, in an exemplary implementation, ratchet teeth 5018 of ratchet/gear 5000 can be evenly spaced, for example and without limitation 1 mm apart, and two driving pawls of ratchet mechanism 5100 can be configured such that a first driving pawl 5004 is offset with respect to a second driving pawn 5006, for example and without limitation 0.5 mm apart. According to an exemplary implementation, driver 5008 would need to rock (for example, pull back and forth) by an amount greater than the pawl offset (0.5 mm in a prior non-limiting example) and less than the teeth spacing (1 mm in a prior non-limiting example) with each oscillation. In the exemplary’ implementation, as long as a driver rocks/advances/drives/oscillates within the region greater than the pawl offset and less than the teeth spacing (between 0.5 mm and 1 mm, in the prior non-limiting example), the ratchet mechanism 5100 will advance/rotate ratchet wheel/gear 5000 by the offset amount between the first driving pawl 5004 and the second driving pawl 5006 (0.55 mm, in the prior non-limiting example) with each reciprocal motion of the driver 5008.

[0059] Referring to FIGs. 7B, 8A and 8B, certain component configurations according to an exemplary' embodiments of the present disclosure can be implements for example and without limitation in a wearable disposable patch pump, such as a pump 100 or a pump 3000, that utilizes a ratchet mechanism, such as a mechanism 2010, or in any device that utilizes a ratchet to achieve fine rotational resolution. As diagrammatically shown in FIGs. 7B, 8A and 8B, in exemplary^ implementations of disclosed embodiments, a ratchet mechanism 8100 comprises a single ratchet gear 8000 with teeth 8018 (rather than two sets of gear teeth 3032, 3034, as illustrated in FIGs. 3B and 3C) that can be pushed''advanced''rotated by driving pawl 7000 comprising two offset 7010, or different length, arms/fingers, a first arm 7024 and a second arm 7026, of a metal spring clip, such as a clip 7022 (rather than the two equal arms 3022 and 3024 of a metal spring clip 2022, as illustrated in FIGs. 3B, 3C, 3D, and 7A) driven by a driver 8008. For example and without limitation, driver 8008 can comprise, or be operatively coupled to, a motor, for example a bi-directional motor. For example and without limitation, driver 8008 can comprise, or be operatively coupled to, a cam, for example a singles and/or uniform surface cam.

[0060] In an exemplary implementation, arms/fingers 7024/7026 can be configured to flex separately. In contrast to configuration shown in examples of FIGs. 3 A, 3B, 3C, 3D, and 4, the arms/fingers 7024/2026 no longer need to travel back and forth as separate units (can go back and forth together). In a further exemplary configuration, cam/driver 8008 can utilize a simpler cam, for example with only one cam face. According to exemplary implementations of disclosed embodiments, the number of increments by which ratchet gear 8000 can be advanced per tooth can be increased or decreased based on the number and configuration of arms of a metal spring clip 7022, such as a first arm 7024 and a second arm 7024, with respect to ratchet gear teeth 8018, for the example by increasing or decreasing the number of arms within the space between two adjacent teeth 8018 of a ratchet gear 8000. Such that, for example, a configuration comprising four amis can have four increments per ratchet tooth. The size of each increment can be controlled by the offset between the arms. Advantageously, exemplary implementations of disclosed embodiments, do not increase configuration size because a single metal spring clip, such as a clip 7022, can comprise multiple arms and the number of ratchet gear teeth 5018 is not increased to achieve finer rotational or linear resolution of ratchet gear 8000. [0061] According to exempl ary implementations of the disclosed embodiments, ratchet gear 5000, 8000 can comprise a round or a circular gear/wheel or a linear rack with teeth, where a pawl is configure to engage the teeth of the ratchet gear. The teeth 5018, 8018 of the ratchet gear 5000, 8000 can be uniform and/or asymmetrical, with each tooth having a first slope on one edge and a second slope on the other edge, where the second slope can be steeper than the first slope. Each pawl can be configured to catch against a second slope of a tooth. A driver can be configured to causes the pawl caught against the second slope of the tooth to push on the tooth to advance the ratchet gear 5000, 8000.

[0062] Furthermore, for example, and without limitation, an exemplary’ implementation of the disclosed embodiments can comprise any number of offset driving pawls and can be applied to any ratchet design.

[0063] According to yet further exemplary implementations of disclosed embodiments, multiple driving pawls can be spaced equally, such that all incremental rotations/advancements of a ratchet are equal. For example, a four-pawl design can have four increments per ratchet tooth. For example, and without limitation, referring to diagrams of FIGs. 6B and 7B, there can be configured four driving pawls instead of two spaced/offset by the same amount. For example and without limitation, if the four driving pawls are offset/spaced by 0.25 mm with respect to each other, and the driving mechanism is configured to reciprocate/ oscillate back and forth, or otherwise drive the pawls, anywhere between 0.25 mm and 0.5 mm, the ratchet mechanism can be advanced

0.25 mm with each motion of the diver. [0064] According to still further exemplary implementations of disclosed embodiments, multiple driving pawls can be spaced unequally, such that all incremental rotations/advancements of a ratchet are not the same. For example, in exemplary implementations, a desired asymmetric pattern of rotations/advancements of a ratchet can be achieved by unequal spacing driving pawls while operating on a ratchet with a uniform spacing of ratchet teeth. For example, and without limitation, according to an exemplary implementation, a three-pawl mechanism comprising three driving pawls unequally offset by predetermined amounts can be configured with respect of single ratchet wheel, such as a wheel 5000, to rotate/move/advance the ratchet wheel, by a first amount (for example, X degrees), then by a second amount (for example, Y degrees), then by a third amount, for example, Z degrees), then repeating X,Y,Z advancement. In a non- limiting example, X can equal 10, Y can equal 8, and Z can equal 9.

[0065] While the present disclosure has been shown and described with reference to certain exemplary’ embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the embodiments of the present disclosure. For example, operative variations and alternative different lead designs may be employed to change dosing resolution, encoders may be used to have feedback of drive mechanism, indexing drives can be employed to repeatably and fail-safe advance the plunger. Generally, for example, non-circular syTinge barrel cross-sections may be employed to optimize space utilization and tailor device size to best suit user comfort. Furthermore, any of the features or elements of any exemplary implementations of the embodiments of the present disclosure as describes above and illustrated in the drawing figures can be implemented individually or in any combination! s) as would be readily appreciated by skilled artisans without departing from the spirit and scope of the embodiments of the present disclosure.

[0066] In addition, the included drawing figures further describe non-limiting examples of implementations of certain exemplary’ embodiments of the present disclosure and aid in the description of technology associated therewith. Any specific or relative dimensions or measurements provided in the drawings other as noted above are exemplary and not intended to limit the scope or content of the inventive design or methodology as understood by artisans skilled in the relevant field of disclosure. The following non-limiting examples of operative variations or alternatives to the disclosed design embodiments are applicable and may further facilitate understanding of exemplary implementations of embodiments of the present disclosure.

[0067] For example, ratchet gear can comprise a round or a circular gear/wheel or a linear rack with teeth, where a pawl is configure to engage the teeth of the ratchet gear. The teeth of the ratchet gear can be uniform and/or asymmetrical, with each tooth having a slope on one edge and a steeper slope on the other edge. A pawl is configured to catch against a steeper sloped edge of a tooth, and a driver is configured to causes the pawl to push on the tooth to advance the ratchet gear.

[0068] teeth to push the ratchet gear in an unrestricted (for example, forward) direction, the pawl easily slides up and over the gently sloped edges of the teeth, with a spring forcing it (often with an audible 'click') into the depression between the teeth as it passes the tip of each tooth. When the teeth move in the opposite (backward) direction, however, the pawl will catch against the steeply sloped edge of the first tooth it encounters, thereby locking it against the tooth and preventing any further motion in that direction.

[0069] For example and without limitation, each of the motion phases of a CAM driver may be reduced or extended to produce a desired ratchet mechanism motion. A cam surface minimum and maximum outer diameter(s) may be adjusted to increase or decrease stroke length, and other motion curve types (such as sinusoidal, harmonic, or other variations) may be considered during the effective motion phase to change acceleration and actuation forces.

[0070] For example and without limitation, some or all of the stopper pins may be eliminated by adding protruding features to the formed baseplate. Elimination of pins may reduce part count and decrease costs to manufacture.

[0071] For example and without limitation, a wide range of materials may be used for some or all of the components used in the designed mechanism.

[0072] For example and without limitation, the shape, size, and number of teeth on the ratchet gear may be changed to satisfy a wide variety of increment sizes.

[0073] Other objects, advantages and salient features of the disclosure will become apparent to those skilled in the art from the details provided, which, taken in conjunction with the annexed drawing figures, disclose exemplary embodiments of the disclosure.

Claims

Exemplary Non-Limiting Claims:

1. A combination comprising: a ratchet gear having an outer circumferential surface comprising a plurality of ratchet teeth with a spacing between adjacent to the ratchet teeth; a first driving pawl configured to individually contact the ratchet teeth to advance the ratchet gear by a first advance increment; a second driving pawl configured to individually contact the ratchet teeth to advance the ratchet gear by a second advance increment; and a driver operatively connected to the first driving pawl and the second driving pawl, wherein the first driving pawl is offset from the second driving pawl by a first pawl offset increment, and the driver causes: the first driving pawl to push on a tooth of the ratchet gear teeth to advance the ratchet gear by the first advance increment; and the second driving pawl to push on the tooth of the ratchet gear teeth to advance the ratchet gear by the second advance increment after the advance by the first advance increment.

2. The combination of claim I , wherein tire first pawl offset increment is less than tire spacing between the adjacent of the ratchet teeth.

3. The combination of claim 1 or 2, comprising a plurality of pawls comprising the first driving pawl and the second driving pawl, wherein the ratchet gear is advanced with respect to the tooth by a plurality of advance increments comprising the first advance increment and the second advance increment, and a number of the advance increments of the ratchet gear with respect to the tooth is increased or decreased based on a number and configuration of the pawls with respect to the tooth of the ratchet gear.

4. The combination of claim 1, 2 or 3, wherein a driver oscillates within a region greater than the first pawl offset increment and less than the spacing between the adjacent of the ratchet teeth.

5. The combination of claim 4, wherein the ratchet gear is advanced by the first pawl offset increment with each reciprocal motion of the driver.

6. The combination of claim 1, 2, 3, 4, or 5, further comprising a metal spring clip, wherein a first arm of the metal spring comprises the first driving pawl, and a second arm of the metal spring comprises the second driving pawl.

7. The combination of claim 1 , 2. 3, 4, 5, or 6, wherein the cam comprises a single outer surface for advancing the first driving pawl and the second driving pawl.

8. The combination of claim 1, further comprising: a third driving pawl configured to individually contact the ratchet teeth to advance the ratchet gear by a third advance increment; and a fourth driving pawl configured to individually contact the ratchet teeth to advance the ratchet gear by a fourth advance increment, wherein the driver is operatively connected to the third driving pawl and the fourth driving pawl, the second driving pawl is offset from the third driving pawl by a second pawl offset increment, the third driving pawl is offset from the fourth driving pawl by a third pawl offset increment, and the driver causes: the third driving pawl to push on a tooth of the ratchet gear teeth to advance the ratchet gear by the third advance increment after the advance by the second advance increment; and the fourth driving pawl to push on the tooth of the ratchet gear teeth to advance the ratchet gear by the fourth advance increment after the advance by the third advance increment.

9. The combination of claim 8, wherein a sum of the first pawl offset increment, the second pawl offset increment, and the third pawl offset increment is less than the spacing between the adjacent of the ratchet teeth.

10. The combination of claim 8 or 9, comprising a plurality of pawls comprising the first driving pawl, the second driving pawl, the third driving pawl and the fourth driving pawl, wherein the ratchet gear is advanced with respect to the tooth by a plurality of advance increments comprising the first advance increment, the second advance increment, the third advance increment, and the fourth advance increment, and a number of the advance increments of the ratchet gear with respect to the tooth is increased or decreased based on a number and configuration of the pawls with respect to the tooth of the ratchet gear.

11. The combination of claim 8, 9, or 10, wherein a driver oscillates within a region greater than the first pawl offset increment, the second pawl offset increment, or the third pawl offset increment, and less than the spacing between the adjacent of the ratchet teeth.

12. The combination of claim 11 , wherein the ratchet gear is advanced by the first pawl offset increment, the second pawl offset increment, or the third pawl offset increment, with each reciprocal motion of the driver.

13. The combination of claim 8, 9, 10, 11 , or 12, further comprising a metal spring clip, wherein a first arm of the metal spring comprises the first driving pawl, a second arm of the metal spring comprises the second driving pawl, a third arm of the metal spring comprises the third driving pawl, and a fourth arm of the metal spring comprises the fourth driving pawl.

14. The combination of claim 8, 9, 10, 11, 12, or 13, wherein the cam comprises a single outer surface for advancing the first driving pawl, the second driving pawl, the third driving pawl and the fourth driving pawl.

15. The combination of claim 1, further comprising: a third driving pawl configured to individually contact the ratchet teeth to advance the ratchet gear by a third advance increment; wherein the driver is operatively connected to the third driving pawl, the second driving pawl is offset from the third driving pawl by a second pawl offset increment, and the driver causes the third driving pawl to push on a tooth of the ratchet gear teeth to advance the ratchet gear by the third advance increment after the advance by the second advance increment.

16. The combination of claim 8, 9, 10, 11, 12, 13, 14, or 15, wherein the first pawl offset increment is equal to the second pawl offset increment.

17. The combination of claim 8, 9, 10, 11, 12, 13, 14, or 15, wherein the first pawl offset increment is not equal to the second pawl offset increment.

18. The combination of claim 8, 9, 10, 11, 12, 13, or 14, wherein the first pawl offset increment, the second pawl offset increment and the third pawl offset increment are equal to each other.

19. The combination of claim 8, 9. 10, 11, 12, 13, or 14, wherein at least one of the first pawl offset increment, the second pawl offset increment and the third pawl offset increment is not equal to at least another of the first pawl offset increment, the second pawl offset increment and the third pawl offset increment.

20. The combination of claim 8, 9, 10, 11, 12, 13, or 14, wherein at least one of the first pawl offset increment, the second pawl offset increment and the third pawl offset increment is equal to at least another of the first pawl offset increment, the second pawl offset increment and the third pawl offset increment.

21. A system comprising the combination as claimed in claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20, the system further comprising: a motor operatively connected to a lead screw by the driver and the ratchet gear to rotate the lead screw; and a plunger disposed inside a barrel such that the plunger moves axially with respect to the barrel due to rotation of the lead screw, whereby fluid can be dispensed from the barrel by the motor rotating the lead screw to drive the plunger to move axially with respect to the barrel, away from a proximal end and toward a distal end forcing the fluid out of the barrel.

22. The system of claim 21, wherein a portion of the lead screw operatively coupled to the ratchet gear is configured outside of the barrel to operatively connect the lead screw to the motor.

23. The system of claim 21 or 22, wherein the motor is a bi-directional motor.

24. The system of claim 21, 22 or 23, wherein the driver comprises the motor.