Plunger rod releasably attached to plunger head in pump device

Abstract

A mechanism for a pump device includes a rotatable cam body axially attached to a distal end of a plunger rod that is retractable in the pump device and rotatable about the plunger rod. The cam body includes a cam surface to cam-interact with a stationary cam pin in the plunger head. The interaction between the cam surface of the cam body and the cam pin causes the cam body to rotate in the plunger head to an engagement angular position in which the cam body and the plunger head are engaged, and a disengagement angular position in which the cam body and the plunger head are disengaged, and rotate from the engaged angular position to the disengaged angular position via a series of alternating push-pull angular positions configured to alternately push and pull a plunger head in the syringe. The cam body is rotated from one angular position to another angular position by reciprocating axial movement of the plunger rod.

Description

[0001] Cross - reference to related applications

[0002] This application claims priority and the benefit of U.S. Provisional Patent Application No. 63 / 429,781, filed on December 2, 2022, entitled "Plunger Rod Releasably Attachable to Plunger Head in a Pump Device", the disclosure of which is incorporated herein by reference in its entirety. Field of the Invention

[0003] The present invention generally relates to systems and methods for coupling a disposable reservoir (e.g., a syringe) of a drug delivery device (e.g., a pump device) to a reusable portion ("RP") of the drug delivery device. More specifically, the present invention relates to a mechanism, a plunger rod, and a plunger head structure that enable the plunger rod to releasably engage with the plunger head and achieve a series of alternating push - pull angular positions between the engagement and disengagement of the plunger rod and the plunger head for alternately pushing and pulling the plunger head in the disposable reservoir.

[0004] Background

[0005] Some liquid drug delivery systems are two - part systems. Such systems typically include a reusable portion and a disposable portion (e.g., a disposable syringe). The reusable portion generally includes an electric motor and a gear system driven by the electric motor, etc. The disposable portion generally includes a reservoir (e.g., a syringe) and a gear - driven plunger device for expelling the drug from the medicament reservoir.

[0006] In a conventional drug delivery system, a plunger device includes a plunger rod (in the form of a "lead screw") and a plunger head (in the form of a "piston"), where the plunger rod is typically inseparable from the plunger head. Additionally, such a plunger device is usually inseparable from the reservoir itself. Thus, using such a plunger device has drawbacks. For example, a disposable reservoir is discarded along with the plunger rod and plunger head after use, which is wasteful and thus uneconomical. Further, since the plunger rod (lead screw) is conventionally an integral part of the disposable reservoir, the coupling between the disposable reservoir and the reusable part often results in reduced precision of the delivered medicament due to some uncertainty regarding the exact or axial position of the plunger rod in the reservoir / syringe. Moreover, the assembly process of the disposable reservoir including the plunger rod is relatively complex and lengthy due to the multiple steps involved in the assembly process. Additionally, inseparably attaching the plunger rod to the disposable reservoir prevents storage or dispensing, or otherwise treating such a disposable reservoir as a "pre-filled" device. Thus, conventional disposable reservoirs are typically filled from vials only shortly before use. Summary of the Invention

[0008] A pump device for delivering a medicament includes a disposable reservoir (e.g., a disposable syringe) and a reusable part detachably coupled to the disposable reservoir. The disposable reservoir includes a plunger head (piston), etc., which can move bidirectionally in the disposable reservoir, e.g., between a proximal end and a distal end of the disposable reservoir. The reusable part includes a plunger rod (lead screw), etc. The plunger head and the plunger rod are designed such that when the disposable reservoir and the reusable part are coupled to each other, the plunger rod can releasably engage with the plunger head as the plunger rod moves linearly bidirectionally (back and forth) in the disposable reservoir in unison with the plunger head.

[0009] The plunger rod and the plunger head together include a quick connecting-release camming mechanism that enables the plunger rod to quickly engage and quickly release from the plunger head. The cam mechanism includes: a rotatable cylindrical cam body axially attached to the distal end of the plunger rod, which is linearly movable between a stow (home) position and a fully extended position in the reusable portion of the pumping device. The cam mechanism is rotatable about the plunger rod camingly. The cam body includes a cam surface to co-act camingly with a stationary cam pin in the plunger head to rotate in the plunger head to an engagement angular position where the cam body and the plunger head are engaged with each other, and a disengagement angular position where the cam body and the plunger head can be disengaged, and to rotate from the engagement angular position to the disengagement angular position. The rotation of the cam body in the plunger head between the engagement angular position and the disengagement angular position is performed via a series of alternating push-pull angular positions for alternately pushing and pulling the plunger head in the disposable reservoir. Rotating the cam body in the plunger head from one angular position to another is achieved by axially (linearly) moving the plunger rod in a reciprocating manner (e.g., by an electric motor) so that the cam pin of the plunger head alternately and camingly engages the cam surface of the cam body, thereby causing an alternating push-pull operation of the plunger rod and thus the plunger head in the disposable reservoir. Brief Description of the Drawings

[0011] Various exemplary embodiments and aspects are shown in the drawings, with the intention that these examples are not restrictive. It should be understood that for simplicity and clarity of illustration, the elements shown in the drawings referred to below are not necessarily drawn to scale. Additionally, where considered appropriate, repeated reference numerals in the drawings indicate identical, corresponding, or similar elements. In the drawings:

[0012] Figures 1A - 1C A pumping device according to an exemplary embodiment is shown;

[0013] Figures 2A - 2C The plunger rod of FIG. 1 with its rotational movement restricted by a rotation restrainer is shown;

[0014] Figure 3 A lead screw type plunger rod according to an exemplary embodiment is shown;

[0015] Figure 4 A plunger head according to an exemplary embodiment is shown;

[0016] Figures 5A - 5B A typical cylindrical cam body according to an exemplary embodiment is shown;

[0017] Figure 6 shows a Figure 3 and Figure 4 on the plunger rod before being inserted into the Figure 2C and Figures 5A - 5B cylindrical cam body;

[0018] Figure 7 shows a zig-zag channel in the cylindrical cam body according to an exemplary embodiment;

[0019] Figure 8 is an exploded view schematically showing an exemplary pulling member of a cylindrical cam body according to an exemplary embodiment;

[0020] Figures 9A - 9L is an exploded view schematically showing the following manner: that is, by the Figure 2C axial movement of the Figure 3 plunger rod in a reciprocating manner by the Figure 5A - the cam surface of the cylindrical cam body of FIG. 5D is Figure 4 alternately engaged by the

[0021] Figures 10A - 10I stationary cam pins to achieve alternate pushing and pulling operations of the plunger rod and thus the plunger head; and

[0022]

[0023] Figure 1A The following description provides various details of the exemplary embodiments. However, this description is not intended to limit the scope of the claims, but rather to explain the various principles of the present invention and exemplary ways of implementing the present invention. Figure 1B 、 Figure 1C ​​A disassembled view, a cross-sectional view, and an assembled pump device 100 according to an exemplary embodiment are respectively shown. The pump device 100 includes a disposable medicament reservoir (e.g., in the form of a disposable syringe 101) and a reusable portion 116. The syringe 101 includes a syringe housing 102, a syringe inlet / outlet port 104 through which the syringe housing 102 can be filled with and drained of a liquid medicament, a plunger head 106 having two annular grooves (108, 110), and two O-rings 112 for the two annular grooves 108 and 110. The plunger head 106 can move bidirectionally in the syringe housing 102 between a first axial (proximal) position 103 on the longitudinal axis 107 of the syringe 101 and a second axial (distal) position 105 on the longitudinal axis 107.

[0024] The reusable portion 116 includes an electric motor 118, a gear train 120, a gear follower shaft 122, a plunger rod 124 (lead screw), a plunger rod rotation limiter 126, a syringe adapter 128 having a hand-grip surface (160, Figure 1C )), a cylindrical cam body 130, and two flat retaining E-clip rings 132 and 134 ("snap" rings). The cylindrical cam body 130 includes a concentric through-hole through which the plunger rod 124 is inserted during the assembly of the pump device. (The concentric hole in the plunger rod 124 is shown at 572 in Figures 5A - 5B ).)

[0025] The gear follower shaft 122 includes an oblong hollow cylindrical body 136 having a proximal portion 138 and a distal end including a gear 142. The gear 142 is operatively coupled to the gear train 120 and can be driven by the gear train 120. The proximal portion 138 of the cylindrical body 136 has a diameter that is reduced relative to the diameter of the body of the gear follower shaft 122, thereby forming a circumferential ledge 140 at the proximal end 138 of the gear follower shaft 122. The circumferential ledge 140 is used to hold the gear follower shaft 122 in the pump housing 114, as shown in Figure 1B . The gear follower shaft 122 includes a nut portion (the nut portion is not shown in Figure 1A but is shown at 156 in Figure 1B ) and a hole or sleeve, the opening of which is shown at 144. The hole or sleeve can be a through-hole or a through-sleeve, which means that the hole or sleeve can have a second opening opposite the opening 144.

[0026] The plunger rod 124 includes two threaded surfaces, one of which is shown at 146. (The two threaded surfaces 146 are positioned opposite to each other, so the other threaded surface is not shown in Figure 1A .) The plunger rod 124 also includes two circumferential grooves 148 and 150 that are recessed into the cylindrical body of the plunger rod 124 to receive and hold the E-clip rings 132 and 134, respectively.

[0027] The reusable portion 116 also includes a housing 114. The housing 114 includes a through hole 152 to enable the electric motor 118 (in combination with the gear train 120 and the gear 142) to axially (linearly) move the plunger rod 124 in both directions; that is, to extend the plunger rod 124 out of the housing 114, through the through hole 152, and to retract the plunger rod 124 completely backward into the housing 114 to the retracted position. The through hole 152 abuts the hole / sleeve opening 144. A space 154 is provided for releasably and securely attaching the syringe 101 and the syringe adapter 128 to the housing 114.

[0028] Figure 1B The assembled pump device 100 is shown, and a cylindrical cam body 130 is axially fixed to the distal end of the plunger rod 124 (between the retaining E-clip rings 132 and 134). This means that the cylindrical cam body 130 cannot move axially (along the axis 107) along the length of the plunger rod 124. However, the cylindrical cam body 130 can rotate freely around the plunger rod 124. The manner in which the cylindrical cam body 130 rotates around the plunger rod 124 will be described further below. Figure 1B Also shown is the plunger rod (lead screw) 124 partially located in the hole / sleeve of the gear follower shaft 122, and its two threaded surfaces 146 are threadedly coupled to the nut portion 156 of the gear follower shaft 122.

[0029] Figure 1B Also shown is that the reusable portion 116 and the disposable syringe 101 are releasably coupled to each other, for example, by using magnets (i.e., using magnetic attraction), snap-fit connectors, bayonet connectors, etc. For example, a permanent magnet can be fixedly embedded in the reusable portion 116 or the disposable syringe 101, and a metal plate that can be magnetically attracted to the magnet can be fixedly embedded in the other part (e.g., in the disposable syringe 101 or the reusable portion 116), such that when the reusable portion 116 and the disposable syringe 101 are brought close to each other, the permanent magnet will magnetically attract the metal plate. In Figure 1B is shown the cylindrical cam body 130 located in the plunger head 106.

[0030] Refer to Figure 1B, when the motor 118 is activated, the motor 118 rotates the gear train 120, which in turn rotates the gear 142, and thus rotates the entire gear follower shaft (122) about the longitudinal axis 107 of the plunger head 106, the cylindrical cam body 130, the gear follower shaft 122, and the plunger rod 124. Since the nut portion 156 is part of or formed into the cylindrical body 136 of the gear follower shaft 122, the nut portion 156 and the gear follower shaft 122 can rotate about the axis of rotation 107 as a single body / unit. Since the gear follower shaft 122 (and thus the nut portion 156) is axially restricted within the reusable portion 116 and the plunger rod 124 is rotationally restricted by the plunger rod rotator restrictor 126, rotation of the nut portion 156 causes the plunger rod 124 to move axially (linearly) along the longitudinal axis 107. The direction of movement of the plunger rod 124 along the axis 107 depends on the direction of rotation of the gear 142 (clockwise or counterclockwise), and the direction of rotation of the gear 142 in turn depends on the direction of rotation of the electric motor 118; that is, changing the direction of rotation of the electric motor 118 changes the direction of rotation of the gear 142, thus changing the direction of rotation of the nut portion 156, and thus changing the linear direction of movement of the plunger rod 124.

[0031] Figures 2A - 2C It is shown that the plunger rod 124 is restricted by the plunger rod restrictor 126 to prevent rotational movement while allowing the plunger rod 124 to move linearly or slide along the longitudinal axis 107 of the plunger rod 124. Refer to Figure 2A , the plunger rod 124 includes two flat truncated surfaces, one of which is shown at 210. (The other flat truncated surface 212 of the plunger rod 124 is opposite to the flat truncated surface 210 and is shown in Figure 2B .) The plunger rod restrictor 126 is generally a circular object including a concentric through hole 220 through which the plunger rod 124 can move linearly (axially) along the longitudinal axis 107 (e.g., by the electric motor 118). To restrict the rotational movement of the plunger rod 124 within the plunger rod restrictor 126, the through hole 220 of the plunger rod restrictor 126 includes two restricting flat surfaces (230, 232) that respectively abut the truncated surfaces 210 and 212 of the plunger rod 124. (The restricting flat surface 230 is shown at Figure 2A , and both the restricting flat surfaces 230 and 232 are shown in Figure 2B .) The plunger rod restrictor 126 also includes two peripheral flat truncated surfaces (240, 250) to prevent the plunger rod restrictor 126 from rotating within the housing 114, for example, due to the rotation of the nut portion 156 of the gear follower shaft 122 during the normal operation of the pump device. Figure 2B A top view of the plunger rod 124 and the plunger rod restrictor 126 is shown.

[0032] Figure 2C shows a cylindrical cam body 130 that is axially fixed to the distal end of the plunger rod 124 by flat retaining E - clips 132 and 134 (and between the flat retaining E - clips 132 and 134). (The E - clip 132 is not shown in Figure 2C .) In Figure 2C , the E - clip 134 installed in the annular groove 150 is shown. Using the retaining E - clips 132 and 134, the cylindrical cam body 130 cannot move axially (along the axis 107) on and along the length of the plunger rod 124. However, the cylindrical cam body 130 can rotate around the plunger rod 124 between the E - clips 132 and 134 by being provided with a cam surface, as shown in Figure 2C and as further described below, for example, in connection with Figures 5A - 5B .

[0033] Figure 2C Also shown is a plunger rod limiter 126 fixedly installed in the housing 114 of the reusable portion 116 of the pump device 100. Figure 2C Also shown in is a part of the power transmission system of the pump 100 that linearly moves the plunger rod 124 along the longitudinal axis 107. The power transmission system can include an electric motor 118, a gear train 120, a gear 142, and a control circuit or system that can control the operation of the power transmission system, etc. The electric motor 118 can be selectively controlled to rotate the gear driven shaft 122 ( Figures 1A - 1B ) bidirectionally (260) in the clockwise or counter - clockwise direction to selectively move the plunger rod 124 (270) in the forward or backward direction. Figure 2C Also shown are annular (circumferential) grooves 108 and 110.

[0034] Figure 3 The plunger rod 124 is shown more clearly. The plunger rod 124 has a proximal end 310 and a distal portion 320. The plunger rod 124 includes two threaded surfaces 146 that are separated by two flat truncated surfaces 210 and 212. (Only the flat truncated surface 210 is shown in Figure 3 .) The distal end 320 of the plunger rod 124 includes two axially - spaced annular (circumferential) grooves 148 and 150 for receiving the two flat retaining E - clips 132 and 134, respectively.

[0035] Figure 4Shows a cylindrical plunger head 106 according to an example embodiment. The plunger head 106 includes a one-sided open cylindrical chamber 410 that is concentrically formed in the plunger head 106 by a cylindrical wall 420. The plunger head 106 also includes a plurality of cam pins that are equally angularly spaced around the axis 107 of the plunger head 106 and are equally radially spaced (equiradially) from the axis 107 and project radially from the cylindrical wall 420 towards the axis 107.( Figure 4 The longitudinal axis 107 is not shown.) As an example, Figure 4 Four cam pins (e.g., cam pins 430, 440, 450, and 460) are shown. Although the plunger head 106 can be linearly moved bidirectionally in the syringe housing 102 along the longitudinal axis 107 (e.g., by using an electric motor 118), rotation of the plunger head 106 about the axis 107 in the syringe housing 102 is prevented by friction between two O-rings (112), typically made of rubber, and the inner cylindrical wall of the syringe housing 102. The cam pins 430, 440, 450, and 460 cooperate camingly with the cam surfaces of the cylindrical cam body 130 to rotate the cylindrical cam body 130 in the plunger head 106 to various operating angular positions about the longitudinal axis 107. The manner of doing so is described herein, for example, in conjunction with Figures 5A - 5B , Figure 6 , Figure 7 and Figures 9A - 9L . The cylindrical cam body 130 may include a plurality of spaced-apart cam surfaces located on the periphery of the cylindrical cam body 130.

[0036] Pulling member: "U"-shaped pulling recess and cam surface

[0037] The cylindrical cam body may include a plurality of pulling members positioned on the distal end of the cylindrical cam body and equally angularly spaced about the axis 107 of the cylindrical cam body 130 and equally radially spaced from the axis 107 over the entire extent of these pulling members. Each pulling member includes a U-shaped pulling recess. The number of pulling members is the same as the number of cam pins. Each U-shaped pulling recess is configured to receive and pulingly engage a corresponding one of the cam pins to pull the cam pin. (All cam pins are of the same size and shape, and all U-shaped pulling recesses are of the same size and shape because during the reciprocating axial movement of the plunger rod 124, any cam pin can engage any U-shaped pulling recess, and any U-shaped pulling recess can engage any cam pin.) When the plunger rod 124 is moved rearward (backward) in the syringe housing 102, for example, by the electric motor 118, the U-shaped pulling recesses are commonly used to axially pull the cam pins in the syringe housing 102, thereby axially pulling the plunger head 106.

[0038] Figures 5A to 5B An example cylindrical cam body (130) including four example pulling members is shown, the four example pulling members being designated P1, P2, P3, and P4, and each of these pulling members includes one pulling recess. However, the cylindrical cam body may include any mechanically useful number of pulling members, such as fewer than four pulling members (e.g., three pulling members) or more than four pulling members (e.g., five pulling members). Additionally, a pulling member may include more than one pulling recess, such as two pulling recesses, three pulling recesses, etc. (An example pulling member including three pulling recesses is shown in Figure 8 .) The number of pulling members included in the cylindrical cam body and the number of pulling recesses that each pulling member may include depend on, for example, the mechanical aspects of the cylindrical cam body, the plunger head, the cam pins, and the syringe (e.g., overall dimensions, inclination of the cam surface, diameter, shape, friction, materials used, etc.). Any number of pulling members and pulling recesses may be used as long as it is mechanically feasible.

[0039] Reference Figures 5A - 5B, the pulling members P1, P2, P3, and P4 are identical in size, shape, and spatial orientation (e.g., relative to the longitudinal axis 107 of the cylindrical cam body 130). The pulling members P1, P2, P3, and P4 include (provide) cam surfaces configured to operatively cooperate with the stationary cam pins 430, 440, 450, and 460 to rotate the cylindrical cam body 130 to a functionally desired angular position in the cylindrical chamber 410 of the plunger head 106 (relative to the cylindrical chamber 410 of the plunger head 106) as the plunger rod 124 (and thus the cylindrical cam body 130 in the plunger head 106) reciprocates axially.

[0040] Each of the pulling members P1, P2, P3, and P4 further includes a pulling recess. When the pulling recesses respectively abut the cam pins 430, 440, 450, and 460, the pulling recesses are respectively pull-engagable with the cam pins 430, 440, 450, and 460, and the plunger rod 124 linearly (longitudinally, axially) pulls the cylindrical cam body 130 in the direction 526. The pulling member P1 includes an exemplary pulling recess 504, and the pulling member P2 includes an exemplary pulling recess 506. (The pulling recesses of the pulling members P3 and P4 are not shown in Figures 5A - 5B but, as explained herein, they are identical to the pulling members P1 and P2 in shape, size, spatial orientation, and function.) Each U-shaped pulling recess generally opens toward the proximal end 508 of the cylindrical cam body 130 at an acute angle relative to a line parallel to the longitudinal axis 107 of the cylindrical cam body 130. (All U-shaped pulling recesses taper toward the distal end 502 of the cylindrical cam body 130 parallel to the axis 107.)

[0041] Each pulling member Pi includes a first prong and a second prong, and the "U"-shaped pulling recess associated with the pulling member Pi is formed by and formed between the first prong and the second prong. For example, the pulling member P1 ( Figures 5A - 5B ) includes a first prong (shown as 510) and a second prong (shown as 512). The prong 510 includes a cam surface 514, and the prong 512 includes a stop surface 516. The U-shaped pulling recess in the pulling member P1 (associated with the pulling member P1) is formed by the cam surface 514 and the stop surface 516 of the pulling member P1 and by the bottom surface (e.g., an arcuate surface, as shown as 504) interconnecting (bridging) the cam surface 514 and the stop surface 516.

[0042] Similarly, the pulling member P2 includes a first prong 518 and a second prong 520 ( Figure 5B), the first tip 518 is the same as the tip 510 of the pulling member P1 in terms of structure, geometry, shape, orientation, and function, and the second tip 520 is the same as the tip 512 of the pulling member P1 in terms of structure, geometry, shape, orientation, and function. The tip 518 includes a cam surface (522) that is the same as the cam surface 514 of the tip 510, and the tip 520 includes a stop surface (524) that is similar to the stop surface 516 of the tip 512. Similar to the U-shaped pulling recess 504 formed by the pulling member P1, the U-shaped pulling recess (associated with the pulling member P2) of the pulling member P2 is formed by the cam surface 522 and the stop surface 524 of the pulling member P2 and the bottom surface (e.g., an arcuate surface as shown in 506) that interconnects (bridges) the cam surface 522 and the stop surface 524. The U-shaped pulling recesses of all other pulling members are formed by similar tips in the same manner as shown and described in connection with the pulling members P1 and P2.

[0043] The cam surfaces of the first tips of the pulling members (e.g., the cam surface 514 of the first tip 510 of the pulling member P1, the cam surface 522 of the first tip 518 of the pulling member P2, etc.) cooperate with the cam pins 430, 440, 450, and 460 respectively to rotate the cylindrical cam body 130 in the cylindrical chamber 410 of the plunger head 106. The cylindrical cam body 130 rotates in the cylindrical chamber 410 until the cam pins 430, 440, 450, and 460 are respectively in pulling engagement with the pulling recesses (pulling recesses 504, 506, etc.) of the pulling members P1, P2, P3, and P4. When the cam pins 430, 440, 450, and 460 are respectively in pulling engagement with the pulling recesses of the pulling members P1, P2, P3, and P4, the electric motor 118 can controllably retract (move backward) the plunger rod 124 in the syringe housing 102 to pull the cylindrical cam body 130 backward (in the direction 526), thereby pulling the plunger head 106 in the syringe housing 102, for example, to fill the syringe housing 102 with a medicament.

[0044] Each pulling member includes three additional cam surfaces (and, according to the example described herein, a total of four cam surfaces). For example, the pulling member P1 further includes cam surfaces 528, 530, and 532, and the pulling member P2 further includes cam surfaces 534, 536, and 538.

[0045] Referring to the pulling member P1, each of the cam surfaces 528 and 530 (in combination with the corresponding cam surfaces of the other pulling members) can cooperate with one of the cam pins 430, 440, 450, and 460 to rotate the cylindrical cam body 130 in the cylindrical chamber 410 to an angular position where the cylindrical cam body 130 can receive all of the cam pins 430, 440, 450, and 460 and cooperate with all of the cam pins to rotate the cylindrical cam body 130 to various operating angular positions. The various operating angular positions of the cylindrical cam body 130 relative to the cam pins and thus relative to the plunger head correspond to different stages of the reciprocating movement of the plunger rod 124, including the engagement of the plunger rod 124 with the plunger head 106 (by means of the cylindrical cam body 130), the alternating pushing and pulling of the plunger head 106 in the syringe housing 102 (by means of the cylindrical cam body 130), and finally the release (disengagement) of the plunger rod 124 from the plunger head 106 by releasing the plunger rod 124 from the cylindrical cam body 130. The various operating angular positions corresponding to the different actuations of the plunger rod 124 are described herein, for example, further described below.

[0046] Referring to the pulling member P2, the cam surfaces 534 and 536 act in the same manner as the cam surfaces 528 and 530 of the pulling member P1, but by cooperating with a different one of the cam pins 430, 440, 450, and 460. All of the other pulling members similarly include two cam surfaces of the same type as, for example, the cam surfaces 528 and 530. All of the cam surfaces and the stop surfaces of the cylindrical cam body 130 are equally angularly spaced about the axis 107 of the cylindrical cam body 130 and are equally radially spaced from the axis 107 over their entire extent.

[0047] Figures 5A - 5B An example cylindrical cam body 130 is shown, which includes four example pulling members, which are represented as P1, P2, P3, and P4, and each of these pulling members includes a pulling recess. As an example, each of the pulling members P1, P2, P3, and P4 includes a pulling recess.

[0048] Pulling member - through channel: inlet funnel and outlet funnel

[0049] Each two adjacent pulling members (Pi, Pi+1) together form (define) a through-channel therebetween, through which a respective one of the cam pins 430, 440, 450, and 460 can enter or leave the cylindrical cam body 130. (During the reciprocating axial movement of the plunger rod 124, the cam pins do not enter and leave the cylindrical cam body 130 through the same through-channel. That is, if a cam pin (e.g., cam pin 430) enters the cylindrical cam body 130 through a specific through-channel, the cam pin only leaves the cylindrical cam body 130 through a different, subsequent through-channel.)

[0050] The through-channel includes an inlet funnel and an outlet funnel. The number of through-channels is the same as the number of cam pins. The through-channels and the cam pins are configured such that each specific cam pin abuts the inlet funnel of a specific one of the through-channels for insertion (i.e., engagement) into the cylindrical cam body 130 when the plunger rod 124 moves the cylindrical cam body 130 forward (544) into the chamber 410 of the plunger head 106, and abuts the outlet funnel of a different through-channel for withdrawal (removal) from the cylindrical cam body 130 when the plunger rod 124 moves the cylindrical cam body 130 backward (526) and away from the chamber 410 of the plunger head 106. (The inlet funnel is axially located in front of the outlet funnel in the cylindrical cam body 130.)

[0051] The inlet funnel Fi is formed by a pair of conjugate axially forward cam surfaces, which pair of conjugate axially forward cam surfaces includes the forward cam surface of the specific pulling member Pi and the forward cam surface of the pulling member Pi+1 adjacent to the specific pulling member (Pi). The outlet funnel Ei is formed by a pair of conjugate axially backward surfaces, which pair of conjugate axially backward surfaces includes the rear cam surface of the specific pulling member Pi and the rear surface of the adjacent pulling member Pi+1. As an example (refer to Figure 5B ), the inlet funnel F1 is formed by a pair of conjugate axially forward cam surfaces, which pair of conjugate axially forward cam surfaces includes the forward cam surface 530 of the pulling member P1 and the forward cam surface 534 of the pulling member P2 adjacent to the pulling member P1. Similarly (see Figures 5A - 5B ), the inlet funnel F4 is formed by a pair of conjugate axially forward cam surfaces, which pair of conjugate axially forward cam surfaces includes the forward cam surface 574 of the pulling member P4 and the forward cam surface 528 of the pulling member P1 adjacent to the pulling member P4.)

[0052] As an example (again refer to Figure 5B) The outlet funnel E1 is formed by a pair of conjugate axially posterior surfaces that include a posterior cam surface 532 of the pulling member P1 and a posterior stop surface 542 of the pulling member P2 adjacent to the pulling member P1. (As used herein, "anterior" and "posterior" positions are relative to the axial position of the cylindrical cam body 130. For example, as "axially anterior", the cam surfaces 530 of the pulling member P1 and 534 of the pulling member P2 enter the cylindrical cam body 130 in front of the cam surface 532 of the pulling member P1 and the surface 542 of the pulling member P2.)

[0053] Each inlet funnel is configured to rotatably receive a respective one of the cam pins and guide the respective one of the cam pins to an engagement angular position when the cylindrical cam body 130 is linearly inserted into the chamber 410 of the plunger head 106 by the plunger rod 124. The linear (axial 107) and non-rotational movement of the cylindrical cam body 130 forward in the direction 544 into the chamber 410 of the plunger head 106 causes the respective cam surfaces of the cylindrical cam body 130 to cooperate with the cam pins 430, 440, 450, and 460 to rotate the cylindrical cam body 130 about the longitudinal axis 107 to an angular position in the chamber 410 where the cam pins are respectively engaged by the pushing recesses, at which position the plunger rod 124 can uniformly push the cam pins 430, 440, 450, and 460, thereby pushing the plunger head 106 in the syringe housing 102.

[0054] Conversely, the linear (axial 107) and non-rotational movement of the cylindrical cam body 130 rearward (backward) in the direction 526 into or within the chamber 410 of the plunger head 106 causes the respective cam surfaces (e.g., other cam surfaces) of the cylindrical cam body 130 to cooperate with the cam pins 430, 440, 450, and 460 to rotate the cylindrical cam body 130 about the longitudinal axis 107 to an angular position in the chamber 410 where the cam pins are respectively engaged by the pulling recesses, and the plunger rod 124 can uniformly pull the cam pins 430, 440, 450, and 460, thereby pulling the plunger head 106 in the syringe housing 102.

[0055] Reference Figures 5A to 5B The inlet funnel F1 is configured to rotatably receive a respective one of the cam pins 430, 440, 450, and 460 and guide the respective one of the cam pins 430, 440, 450, and 460 to an engagement angular position in the cylindrical cam body 130 when the cylindrical cam body 130 is linearly inserted into the chamber 410 by the plunger rod 124. (The linear movement of the cylindrical cam body 130 against the cam pins in the direction 544 causes the cylindrical cam body 130 to rotate about the axis 107.) Figures 5A - 5BAn example cylindrical cam body (130) having four example pushing members is shown. Accordingly, there are a total of four through-channels, and each through-channel includes an opening similar to opening 540. Figure 5B Three other inlet funnels are shown; namely, F2 (defined jointly by pulling members P2 and P3 and located between pulling member P2 and pulling member P3), F3 (defined jointly by pulling members P3 and P4 and located between pulling member P3 and pulling member P4), and F4 (defined jointly by pulling members P4 and P1 and located between pulling member P4 and pulling member P1).

[0056] Reference Figure 5B , the outlet funnel E1 is configured such that when the cam body 130 linearly retracts from the chamber 410 of the plunger head 106, the cylindrical cam body 130 rotatably receives a respective one of the cam pins 430, 440, 450, and 460 and guides the respective one of the cam pins 430, 440, 450, and 460 away from the disengaging angular position in the cylindrical cam body 130. (The linear movement of the cylindrical cam body 130 away from the cam pins causes the cylindrical cam body 130 to rotate about axis 107 until the cam pins can be released from the cylindrical cam body 130 via the outlet funnel, respectively.)

[0057] Each inlet funnel (e.g., inlet funnel F1) has a large opening at the distal end 502 of the cylindrical cam body 130, and each inlet funnel (e.g., inlet funnel F1) tapers (narrows) from the distal end 502 of the cylindrical cam body 130 toward the proximal end 508. Each outlet funnel (e.g., outlet funnel E1) has a large opening that opens toward the proximal end 508 of the cylindrical cam body 130, and each outlet funnel (e.g., outlet funnel E1) tapers (narrows) toward the distal end 502 of the cylindrical cam body 130. Accordingly, the inlet funnels (F1, Figure 5B ) and the outlet funnels (E1, Figure 5B ) of each through-channel are longitudinally "back-to-back" positioned such that the narrow openings of the inlet funnel and the outlet funnel coincide. Reference Figure 5B , the inlet funnel F1 and the outlet funnel E1 are longitudinally back-to-back positioned such that the narrow openings of the inlet funnel and the outlet funnel coincide as opening 540.

[0058] Tooth - cam surface and pushing recess

[0059] The cylindrical cam body 130 includes a number “n” of teeth that are circumferentially and equally angularly spaced about axis 107 and are equally radially spaced from axis 107 throughout their extent and are disposed on the periphery of the cylindrical cam body 130 to provide “n” cam surfaces and “n” stop surfaces on the proximal end of the cylindrical cam body. The “n” cam surfaces and the “n” stop surfaces provided by the “n” teeth together form “n” “U”-shaped pushing recesses for enabling the plunger rod 124 to push the plunger head 106 via a cam pin, for example to expel a medicament contained in the syringe housing 102. (For example, expelling the medicament from the syringe housing can be performed for priming an infusion set and / or for subcutaneous delivery of the medicament to a patient, for example.)

[0060] By way of example, the cylindrical cam body 130 includes eight (n = 8) circumferential teeth, which are sequentially denoted as T1, T2, T3, T4, T5, T6, T7, and T8. The teeth T1 - T8 are circumferentially, equally angularly, and equally radially spaced about the longitudinal axis 107 of the cylindrical cam body 130 at the proximal end 508 of the cylindrical cam body 130.( Figure 5A Teeth T1, T2, T3, T4, and T8 are shown. Figure 5B Teeth T1, T2, T3, T4, and T5 are shown.) The circumferential teeth T1, T2, T3, T4, T5, T6, T7, and T8 together form a serrated crown 578 in the proximal end 508 of the cylindrical cam body 130, and each tooth of the serrated crown 578 is a right triangle including a cam surface and a stop surface.

[0061] The teeth T1, T2, T3, T4, T5, T6, T7, and T8 form eight structurally identical “U”-shaped pushing recesses therebetween. Each particular “U”-shaped pushing recess is formed by: the cam surface of a particular tooth (T i ) and the stop surface of the subsequent tooth (T i+1 ), and the bottom surface that interconnects the cam surface of the particular tooth (T i ) with the stop surface of the subsequent (consecutive) tooth (T i+1 ) and thereby forms a continuous surface. As an example (refer to Figure 5B ), the “U”-shaped pushing recess 546 is formed between teeth T2 and T3, i.e., by the cam surface 548 of tooth T2 and the stop surface 550 of tooth T3 and by the bottom surface (552) that interconnects the cam surface 548 and the stop surface 552. (The cam surface 548, the stop surface 550, and the bottom surface 552 form a continuous surface.)

[0062] Similarly, a U-shaped pushing recess 554 is formed between teeth T3 and T4, i.e., formed by the cam surface 556 of tooth T3 and the stop surface 558 of tooth T4 and by the bottom surface (560) that interconnects the cam surface 556 and the stop surface 558 and thereby forms a continuous surface. (The cam surface 556, the stop surface 558, and the bottom surface 560 form a continuous surface.) Similarly, a U-shaped pushing recess 562 is formed between teeth T1 and T2, i.e., formed by the cam surface 564 ( Figure 5A ) of tooth T1 and the stop surface 566 ( Figure 5A ) of tooth T2 and by the bottom surface (568) that interconnects the cam surface 564 and the stop surface 566 and thereby forms a continuous surface. The remaining U-shaped pushing recesses are formed in a similar manner between teeth T4 and T5, between teeth T5 and T6, between teeth T6 and T7, between teeth T7 and T8, and between teeth T8 and T1. (The cam surface 564, the stop surface 566, and the bottom surface 568 form a continuous surface.)

[0063] The cam surfaces of the teeth (e.g., the cam surface 564 of tooth T1, the cam surface 548 of tooth T2, the cam surface 556 of tooth T3, etc.) cooperate with the cam pins 430, 440, 450, and 460, respectively, to rotate the cylindrical cam body 130 in the cylindrical chamber 410 of the plunger head 106. The cylindrical cam body 130 rotates in the cylindrical chamber 410 until the cam pins 430, 440, 450, and 460 engage the pushing recesses (pushing recesses 562, 546, 554, etc.), respectively. When the cam pins 430, 440, 450, and 460 engage the pushing recesses, respectively, the electric motor 118 can controllably push (move forward) the plunger rod 124 in the syringe housing 102 to push the cylindrical cam body 130 forward (in the direction 544), thereby pushing the plunger head 106 in the syringe housing 102, e.g., to expel a medicament from the syringe housing 102, e.g., to prime an infusion set and / or to deliver the medicament to a patient.

[0064] The cam surfaces of the cylindrical cam body 130 can, for example, follow a 30° helix around the cylindrical cam body 130, and these cam surfaces are configured to impart a unidirectional rotational movement to the cylindrical cam body 130 when the cylindrical cam body 130 reciprocates axially (by the plunger rod 124) against the rotationally fixed cam pins of the plunger head 106. (The plunger rod 124 repeatedly moves axially forward and backward to align the alternating cam surfaces with the stationary cam pins, thereby alternately holding the cam body 130 in the plunger head pushing position and the plunger head pulling position.)

[0065] Unidirectional rotation of the cylindrical cam body

[0066] Generally, the orientation of the pulling member and the cam surfaces of the teeth of the cylindrical cam body 130 is such that reciprocating movement of the cylindrical cam body 130 in the chamber 410 of the plunger head 106 along the axis of rotation 107 by the plunger rod 124 imparts a unidirectional rotational movement to the cylindrical cam body 130 in the chamber 410 ( Figure 5A 576 in ) as well as longitudinal reciprocating movement. (The unidirectional rotational direction, which is the rotational direction 576 in this example, is referred to herein as the "primary rotational direction".) However, there is a conditional exception to this concept, which is related to the inlet funnels, among other factors, as described below.

[0067] Before the plunger rod 124 engages the plunger head 106 via the cylindrical cam body 130 and the cam pins (i.e., before the cylindrical cam body 130 is pushed into the chamber 410 of the plunger head 106 by the plunger rod 124), the cylindrical cam body 130 rotates freely on the plunger rod 124 between two retaining E - clip rings 132 and 134. This means that the initial angular orientation of the inlet funnels F1, F2, F3, and F4 of the cylindrical cam body 130 relative to the angled stationary cam pins in the chamber 410 is random. Additionally, the angular orientation of the chamber 410 (and thus the cam pins) relative to the syringe housing can vary from one syringe to another (e.g., during the assembly of the syringe), which adds another factor to the randomness of the alignment of the "inlet funnels" to the "cam pins".

[0068] Accordingly, when engaging between the cylindrical cam body 130 and the cam pins, the front cam surface of the inlet funnel that can potentially rotate the cylindrical cam body 130 (''potentially'' - if these cam surfaces cooperate with the cam pins) in the same main rotation direction 576 as the other cam surfaces of the cylindrical cam body 130 does not have to be angled with respect to the cam pins. The front cam surface of the inlet funnel that maintains the main rotation direction 576 when cooperating with the cam pins in a cam manner is referred to herein as the ''main cam surface''. (The inlet funnel cam surfaces 530, 536, and 574 are example main cam surfaces.) However, it is possible that the front cam surface of the funnel that can potentially rotate the cylindrical cam body 130 in the main rotation direction 576 is not angled with respect to the cam pins; that is, when engaging between the cylindrical cam body 130 and the cam pins, the front cam surface of the funnel can be angled relative to the cam pins. Accordingly, in the case of an angular misalignment between the main cam surface and the cam pins, the cam surfaces that can be aligned with the cam pins are other front cam surfaces of the inlet funnel, which are referred to herein as ''auxiliary cam surfaces''. (The inlet funnel cam surfaces 528 and 534 are example auxiliary cam surfaces.) In this case, the cooperation between the auxiliary cam surface and the cam pins will cause the cylindrical cam body 130 to rotate in a direction opposite to the main rotation direction 576. However, there is a third option, where the cam pins are aligned with the openings 540 in the through channels, in which case the cam pins will reach the cam surfaces adjacent to the teeth of the through channels respectively, without causing the cylindrical cam body 130 to rotate in any direction.

[0069] When the plunger rod 124 is moved forward, for example, by the electric motor 118, the U-shaped pushing recesses are configured to axially push the cam pins (e.g., cam pins 330, 340, 350, and 360) in the syringe housing 102 in the forward direction (in direction 544) in unison, thereby axially pushing the plunger head 106 to move the cylindrical cam body 130 in direction 544 to, for example, expel the medicament from the syringe housing 102.

[0070] In an example embodiment, the number of teeth (''n'') can be twice the number of pulling members ''k'' (e.g., k = n / 2). Continuing with this example, the number of pulling members is four (k = 4), as, for example Figures 5A - 5B shown Figures 5A - 5B shows example pulling members P1, P2, P3, and P4. Each U-shaped pushing recess generally opens towards the distal end 502 of the cylindrical cam body 130 at an acute angle with respect to a line parallel to the longitudinal axis of the cam body 130. (All U-shaped pushing recesses taper towards the proximal end 508 of the cylindrical cam body 130 parallel to the axis 107.)

[0071] "n" circumferential teeth and "n / 2" pulling members are circumferentially arranged on the cylindrical cam body in an alternating relationship, such that each odd tooth T 2i-1 (e.g., teeth T1, T3, T5, etc.) is structurally adjacent (positioned opposite) to a through-channel formed jointly by two adjacent pulling members Pi and Pi+1 and formed between the two adjacent pulling members Pi and Pi+1, and each even tooth T 2i (e.g., teeth T2, T4, T6, etc.) is structurally adjacent (positioned opposite) to a U-shaped pulling recess of a specific pulling member (P i+1 ). For example, teeth T1, T2, T3, T4, T5, T6, T7, and T8 and pulling members P1, P2, P3, and P4 are circumferentially arranged on the cylindrical cam body 130 in an alternating relationship, such that:

[0072] ● Tooth T1 is adjacent to a through-channel formed jointly by adjacent pulling members P1 and P4 and formed between the adjacent pulling members P1 and P4;

[0073] ● Tooth T2 is adjacent to the U-shaped pulling recess 570 of pulling member P1;

[0074] ● Tooth T3 is adjacent to a through-channel formed jointly by adjacent pulling members P1 and P2 and formed between the adjacent pulling members P1 and P2;

[0075] ● Tooth T4 is adjacent to the U-shaped pulling recess 580 of pulling member P2( Figure 5A ), and so on.

[0076] Figure 6 The assembled cylindrical cam body 130 and the plunger rod 124 are shown, and the cylindrical cam body 130 before being inserted into the plunger head 106 through the plunger rod 124 is shown; that is:

[0077] ● A cam pin 430 (not shown in Figure 6 ) radially opposite to the cam pin 450 abuts (610) a through-channel formed by pulling members P1 and P2 and formed between the pulling members P1 and P2;

[0078] ● A cam pin 460 of the plunger head 106 abuts (620) a through-channel formed by pulling members P2 and P3 (pulling member P3 is not shown in Figure 6 ) and formed between the pulling members P2 and P3;

[0079] ● A cam pin 450 of the plunger head 106 abuts a through-channel formed by pulling members P3 and P4 (pulling member P3 is not shown in Figure 6 ) and formed between the pulling members P3 and P4, and

[0080] ● The cam pin 440 positioned radially opposite to the cam pin 460 ( Figure 6 , not shown in

[0081] ) abuts (630) a through-channel formed between and by the pulling members P4 and P1. Figure 6 In the exemplary orientation of the cylindrical cam body 130 relative to the plunger head 106 shown, the cam surface of the cylindrical cam body 130 abutting the cam pin is a rotation-retaining cam surface. Thus, when the plunger rod 124 is linearly (axially) moved in the forward direction (544) along the longitudinal axis 107, for example, by an electric motor 118, the front cam surface of the cylindrical cam body 130 and the cam pins of the plunger head 106 cooperate in a cam manner to rotate the cylindrical cam body 130 in the direction 576.

[0082] The “n / 2” pulling members are axially away from the “n” teeth of the serrated crown, thereby defining a guiding “zigzag” channel for the cam pins in the cylindrical cam body in the plunger head to pass through when the plunger rod reciprocates axially and the cylindrical cam body rotates from the engagement angular position (where the cam pins respectively abut the through-channel) to the disengagement angular position (where the cam pins respectively abut the through-channel) via a series of alternating push-and-pull angular positions. (The guiding zigzag channel guides the cam pins in the cylindrical cam body from one recess to another, and accordingly from one operating angular position of the cylindrical cam body to another operating angular position.)

[0083] Referring to Figure 7 , the pulling members P1, P2, P3, and P4 (the pulling member P3 is not shown in Figure 7 ) are axially away from the serrated crown 578, thereby defining a guiding “zigzag” channel, which is shown by the dashed (dotted) line 710 in Figure 7 . (The five arrows on the dashed line 710 indicate the moving direction of the cam pins relative to the zigzag channel 710 when the cylindrical cam body 130 rotates in the direction 576 and reciprocates in the plunger head 106.)

[0084] The guiding zigzag channel 710 surrounds the outer surface 720 of the cylindrical cam body 130, and each cam pin of the plunger head 106 enters or gets into the guiding zigzag channel 710 via an opening in the corresponding through-channel (e.g., Figure 5B 540 in

[0085] The rotation "cycle" of the cylindrical cam body 130 in the plunger head 106 includes the cylindrical cam body 130 rotating from the engagement angle position where the cam pins of the plunger head 106 respectively abut the inlet funnel to the disengagement angle position where the cam pins respectively abut the outlet funnel, such that each particular cam pin abuts the outlet funnel of the through-channel after the through-channel of the inlet funnel including the particular cam pin. The rotation of the cylindrical cam body 130 from the engagement angle position to the disengagement angle position is accomplished via a continuous series of alternating push and pull angle positions as the plunger rod 124 reciprocates axially, as described herein, for example, hereinafter.

[0086] For simplicity, Figure 7 Shown is a zigzag channel 710 through which an example cam pin (e.g., cam pin 440) passes. (Other cam pins of the plunger head enter the zigzag channel 710 at different entry points and pass through different portions of the zigzag channel 710.) When the cylindrical cam body 130 is pushed forward (544) into the plunger head 106 by the plunger rod 124 (as Figure 6 shown), the cam pin 440 enters (730) the cylindrical cam body 130 and enters the zigzag channel 710 by entering the inlet funnel 740 and moving along the inlet passage path 750. The cam pin 440 is stationary while the cylindrical cam body 130 is rotated from one angular position to another by the cam pin 440 (and by other cam pins of the plunger head) as the cylindrical cam body 130 reciprocates axially in the plunger head 106 by the reciprocating plunger rod 124.

[0087] When the cam pin 440 enters the inlet funnel 740 via landmark A1 (by pushing the cylindrical cam body 130 against the cam pin 440), the cam pin 440 rotates the cylindrical cam body 130 in the direction 576 or in the opposite direction, depending on which front cam surface (the rotation retaining cam surface or the reverse rotation cam surface) the cam pin 440 acts upon. If neither of these cam surfaces is acted upon by the cam pin 440, the cam pin 440 will enter the zigzag channel 710 along the inlet path 750 without rotating the cylindrical cam body 130.

[0088] For simplicity of description, the cam pin 440 is shown in Figure 7Five different moments and markings (designated as A1, A2, A3, A4, and A5) along its path relative to the cylindrical cam body 130 are shown to illustrate the various angular positions of the cylindrical cam body 130 as it is rotated by the stationary cam pin 440 and relative to the stationary cam pin 440. Marking A1 corresponds to the engagement angular position of the cylindrical cam body 130 (relative to the cam pin 440) at which the cylindrical cam body 130 can be engaged with the plunger head 106 by moving the cylindrical cam body 130 in the forward direction 544 against the stationary plunger head 106. Markings A2 through A4 represent a continuous series of alternating push and pull angular positions of the cylindrical cam body 130 relative to the cam pin 440. Marking A5 corresponds to the disengagement angular position (relative to the cam pin 440) at which the cylindrical cam body 130 can be disengaged from the plunger head 106 by moving the cylindrical cam body 130 away from the stationary plunger head 106.

[0089] Regarding markings A2 through A4, marking A2 represents a first U-shaped push recess corresponding to the first push angular position at which the plunger rod 124 can push the plunger head 106 forward, marking A3 represents a U-shaped pull recess corresponding to the pull angular position at which the plunger rod 124 can pull the plunger head 106 backward, and marking A4 represents a second U-shaped push recess corresponding to the second push angular position at which the plunger rod 124 can push the plunger head 106 forward again, such that the push recesses and pull recesses have an alternating "nature".

[0090] When the cam pin 440 is at marking A4 (after passing in a zigzag pattern along the zigzag channel 710), the cylindrical cam body 130 can first be pushed forward (544) by the plunger rod 124 (e.g., to expel the medicament from the syringe housing 102), and then sequentially pulled by the plunger rod 124 in order to disengage the cylindrical cam body 130 from the cam pin 440. Disengagement of the cam pin 440 from the cylindrical cam body 130 is accomplished by pulling the cylindrical cam body 130 backward to move the cam pin 440 out of the zigzag channel 710, into the outlet funnel 760, and generally out of the cylindrical cam body 130 (770) along the outlet passage path 780.

[0091] Figure 7The example shown illustrates a cylindrical cam body with a specific design, where each of the pulling members P1, P2, P3, and P4 includes a pulling recess. This design (i.e., the pulling members include a pulling recess) provides a series of three alternating push-pull angular positions for each cam pin, as well as a total of five angular positions, including an engagement angular position (A1), a series of three alternating push-pull angular positions (A2 to A4), and a disengagement angular position (A5). However, in other embodiments, the cylindrical cam body can be designed to provide different numbers of pulling angular positions and pulling angular positions, as described below in connection with Figure 8 as described. The zigzag channel formed in the cylindrical cam body (e.g., zigzag channel xxx, Figure xx) guides the cam pins in the cylindrical cam body from one recess to another and, correspondingly, from one operating angular position of the cylindrical cam body to another operating angular position.)

[0092] Figure 8 Figure 8 schematically shows an unfolded cylindrical cam body 800 according to another embodiment. Similar to the cylindrical cam body 130, the cylindrical cam body 800 includes four pulling members, which are denoted as P1', P2', P3', and P4'. However, different from the cylindrical cam body 130, each of the pulling members P1', P2', P3', and P4' includes (provides) three pulling recesses. For example, the pulling member P1' includes pulling recesses 810, 820, and 830. Thus, the cylindrical cam body 800 provides a total of twelve pulling recesses. The four pulling members P1', P2', P3', and P4' define four through channels therebetween. Thus, the cylindrical cam body 800 is also designed to cooperate with a plunger head similar to the plunger head 106 including four cam pins. The cam body 800 further includes sixteen teeth, which are denoted as T1', T2', T3',..., T16', and sixteen pushing recesses are defined between these teeth, which can be similar to the teeth T1, T2, T3,..., T8 of the cylindrical cam body 130.

[0093] As described in connection with the cylindrical cam body 130, a cam pin (e.g., cam pin 440) enters the cylindrical cam body 130 via a specific through channel and leaves the cam body 130 via a subsequent (continuous) through channel. Similarly, the cam pin 840 enters (850) the cylindrical cam body 800 via the through channel 860 and leaves (870) the cylindrical cam body 800 via a subsequent (continuous) through channel 880.

[0094] In Figure 8In it, the cam pin 840 is shown at nine different moments and markings (designated as B1, B2, B3, B4, B5, B6, B7, B8, and B9) along a zigzag path 890 relative to the cylindrical cam body 800. The nine markings show the various angular positions that the cylindrical cam body 800 rotates continuously to through the stationary cam pin 840 and relative to the stationary cam pin 840. Marking B1 corresponds to the engagement angular position of the cylindrical cam body 800 (relative to the cam pin 840) at which the cylindrical cam body 800 can engage with the plunger head by moving the cylindrical cam body 800 in the forward direction against the stationary plunger head. Markings B2 to B8 represent a continuous series of alternating push - pull angular positions of the cylindrical cam body 800 relative to the cam pin 840. Marking B9 corresponds to the disengagement angular position (relative to the cam pin 840) at which the cylindrical cam body 800 can disengage from the plunger head by moving the cylindrical cam body 800 away from the stationary plunger head.

[0095] Regarding markings B2 to B8, marking B2 represents a first U - shaped push recess corresponding to the first push angular position at which the plunger rod can push the plunger head forward. Marking B3 represents a U - shaped pull recess corresponding to the first pull angular position at which the plunger rod can pull the plunger head backward. Marking B4 represents a second U - shaped push recess corresponding to the second push angular position at which the plunger rod can push the plunger head forward again. Marking B5 represents a U - shaped pull recess corresponding to the second pull angular position at which the plunger rod can pull the plunger head backward. Marking B6 represents a third U - shaped push recess corresponding to the third push angular position at which the plunger rod can push the plunger head forward again. B7 represents a U - shaped pull recess corresponding to the third pull angular position at which the plunger rod can pull the plunger head backward. Marking B8 represents a fourth U - shaped push recess corresponding to the fourth push angular position at which the plunger rod can push the plunger head forward again, so the push recesses and pull recesses have an alternating "nature".

[0096] Figures 9A to 9L An exploded view of an exemplary cylindrical cam body is shown, which step - by - step shows the manner in which the cam surface of the cylindrical cam body engages with an exemplary cam pin (co - acting with the exemplary cam pin) to effect an alternating push - pull operation of the cylindrical cam body and thus an alternating push - pull operation of the plunger head of the syringe. The cylindrical cam body 910 (similar to the cylindrical cam body 130 in this example) is axially locked to the distal end of the plunger rod 920 (similar to the plunger rod 124 in this example) but can rotate bidirectionally about the plunger rod. The pulling members P1", P2", P3", and P4" are respectively similar to the pulling members P1, P2, P3, and P4 of the cylindrical cam body 130. The reference line 970 indicates the stationary angular position of the cam pin 930. As with respect to the cylindrical cam body 910.

[0097] Figure 9A Shows the cylindrical cam body 910 before engagement with the cam pin 930 (similar to the cam pins 430, 440, 450, and 460 in this example). The cam body 910 provides a "five-position" cycle, which includes the cylindrical cam body 910 rotating from the engagement angular position (position A1) where the cam pin 930 abuts the inlet funnel 960 to the disengagement angular position (position A5), at which the cam pin 930 abuts the outlet funnel 962 of the through-channel after the through-channel including the inlet funnel 960. The rotation of the cylindrical cam body 910 from the engagement angular position A1 to the disengagement angular position A5 is accomplished via a continuous series of alternating push and pull angular positions as the plunger rod 920 reciprocates axially (942), as described herein, for example, as described below. In this example, the series of alternating push and pull angular positions includes two push angular positions (angular positions A2 and A4) and one pull angular position (angular position A3), which is angularly after the push angular position A2 and angularly before the push angular position A4.

[0098] Reference Figure 9A , when the plunger rod 920 moves the cylindrical cam body 910 forward (in the direction 940) into the plunger head (the plunger head is not shown in Figure 9A ), this movement causes the stationary cam pin 930 to enter (950) the inlet funnel 960, which is formed by and formed between the pull members P1" and P2". When the cylindrical cam body 910 continues to move in the direction 940, the cam pin 930 continues its movement through the inlet funnel 960 into the cylindrical cam body 910 until the front cam surface 980 of the pull member P1" engages the cam pin 930 in a cam manner. The reference numerals 990, 992, 994, and 996 denote successive legs of the zigzag channel through which the cam pin 930 travels as the plunger rod 920 reciprocates (942) along the longitudinal axis 107 (e.g., up and down in Figures 9A - 9L ).

[0099] Figure 9B Shows the front cam surface 980 engaged by the cam pin 930 in a cam manner. As Figure 9CAs shown, when the cylindrical cam body 910 continues to move further in the direction 940, the cam surface 980 and the cam pin 930 act in a cam-like manner together to cause the cylindrical cam body 910 on the plunger rod 920 to rotate about the axis of rotation 107 in the direction 982 until the cylindrical cam body 910 reaches the engagement angle position A1. When the cylindrical cam body 910 continues to move further in the direction 940, the cam pin 930 continues its movement from the engagement angle position A1 deeper into the cylindrical cam body 910 along the segment 990 of the zigzag channel towards the push angle position A2. More specifically, in order for the cam pin 930 to reach the push angle position A2, the cylindrical cam body 910 first moves in the direction 940 (which is equivalent to moving the cam pin 930 downward relative to the cam body 910 along the reference line 970) until the cam surface 984 of the tooth T3” is cam-engaged by the cam pin 930, as Figure 9D shown.( Figure 9D The cam surface 984 of the tooth T3” cam-engaged by the cam pin 930 is shown.) Then (refer to Figure 9D ), further moving the cylindrical cam body 910 forward in the direction 940 causes the cam surface 984 and the cam pin 930 to act in a cam-like manner together to cause the cylindrical cam body 910 to rotate further in the direction 982 until the cylindrical cam body 910 reaches the push angle position A2, as Figure 9E shown.

[0100] Referring again to Figure 9B , the longitudinal (axial) spacing 946 between the pull recess and the push recess is the axial distance that the cylindrical cam body 910 must travel in order for the cam pin to switch from engaging the push recess to engaging the pull recess, and vice versa. Since the plunger rod is an integral part of the reusable part of the pump device, the exact axial position of the plunger rod and the spacing between the pull recess and the push recess (spacing 946) are always known to the controller of the pump device. Therefore, in the case where the spacing 946 is a known factor to the controller of the pump device, the controller always “knows” the exact axial position of the plunger head 106 in the syringe housing 102. Therefore, the pump device can precisely control the flow rate of the medicament and the dose of the medicament delivered to the subject using the pump device.

[0101] Referring again to Figure 9B , the line 928 is parallel to the longitudinal axis 107. The center line 934 of the tooth T8”, and thus the entire tooth, is inclined at an angle α with respect to the line 928. For example, the value of the angle α can be between 30° and 50° (e.g., α = 45°). In the developed view, all the teeth of the serrated crown are inclined at the same angle and in the same direction.( Figures 9A - 9L The teeth T1÷T8 in

[0102] Reference Figure 9E , when the cam pin 930 is in the angular position A2, the forward movement (in the direction 940) of the plunger rod 920 causes the pushing recess associated with the angular position A2 to push the cylindrical cam body 910 forward in the syringe, thus pushing the plunger head ( Figure 1A , 106 in FIG. 2), for example, from the proximal end 103 of the syringe housing 102 ( Figure 1A ) to the distal end 105 of the syringe housing 102 ( Figure 1A ) to expel air from the syringe housing, for example, in preparation for filling the syringe with a medicament. After the plunger head reaches the distal end of the syringe housing, or at any time before the plunger head reaches the distal end of the syringe housing, the direction of the axial movement of the plunger rod 920 can be reversed, i.e., the plunger rod 920 can move backward (e.g., by an electric motor 118) in the direction 944.

[0103] Reference Figure 9E , when the cylindrical cam body 910 is moved backward (in the direction 944) by the plunger rod 920, the cam pin 930 continues to "travel" in the cylindrical cam body 910 along a segment 992 of the zigzag channel from the pushing angular position A2 toward the pulling angular position A3. More specifically, in order for the cam pin 930 to reach the pulling angular position A3, the cylindrical cam body 910 first moves in the direction 944 (which is equivalent to moving the cam pin 930 upward relative to the cam body 910 along the reference line 970) until the cam surface 986 of the pulling member P2" is cam-engaged by the cam pin 930, as Figure 9F shown. ( Figure 9F The cam surface 986 of the pulling member P2" cam-engaged by the cam pin 930 is shown.) Then (refer to Figure 9F ), further moving the cylindrical cam body 910 backward in the direction 944 causes the cam surface 986 to act in cam cooperation with the cam pin 930 to cause the cylindrical cam body 910 to rotate again in the direction 982 until the cylindrical cam body 910 reaches the pulling angular position A3, as Figure 9G shown.

[0104] Reference Figure 9G , when the cam pin 930 is in the angular position A3, the backward movement (in the direction 944) of the plunger rod 920 causes the pulling recess associated with the angular position A3 to pull the cylindrical cam body 910 backward in the syringe, thus pulling the plunger head ( Figure 1A , 106 in FIG. 2), for example, from the distal end 105 of the syringe housing 102 ( Figure 1A ) to the proximal end 103 of the syringe housing 102 ( Figure 1A) For example, the syringe housing is filled with a medicament. After the plunger head reaches the proximal end of the syringe housing, or at any time before the plunger head reaches the proximal end of the syringe housing, the direction of the axial movement of the plunger rod 920 can be reversed, i.e., the plunger rod 920 can be moved forward again (e.g., by the electric motor 118) in the direction 940.

[0105] Reference Figure 9G , when the cylindrical cam body 910 moves again in the direction 940, the cam pin 930 continues its travel in the cylindrical cam body 910 along the segment 994 of the zigzag channel from the pulling angular position A3 towards the pushing angular position A4. More specifically, in order for the cam pin 930 to reach the pushing angular position A4, the cylindrical cam body 910 moves in the direction 940 (which is equivalent to moving the cam pin 930 downward relative to the cam body 910 along the reference line 970) until the cam surface 988 of the tooth T4” is cam-engaged by the cam pin 930, as Figure 9H shown. ( Figure 9H The cam surface 988 of the tooth T4” cam-engaged by the cam pin 930 is shown.) Then (reference Figure 9H ), further moving the cylindrical cam body 910 forward (in the direction 940) causes the cam surface 988 to act in cam cooperation with the cam pin 930 to rotate the cylindrical cam body 910 again in the direction 982 until the cylindrical cam body 910 reaches the pushing angular position A4, as Figure 9I shown.

[0106] Reference Figure 9I , when the cam pin 930 is in the angular position A4, the forward (in the direction 940) movement of the plunger rod 920 causes the pushing recess associated with the angular position A4 to push the cylindrical cam body 910 forward in the syringe, thus pushing the plunger head ( Figure 1A 、106 in Figure 2), for example, from the proximal end 103 of the syringe housing 102 ( Figure 1A ) to the distal end 105 of the syringe housing 102 ( Figure 1A ), for example, to deliver the medicament filled in the syringe housing to the patient. After the plunger head reaches the distal end of the syringe housing, or at any time before the plunger head reaches the distal end of the syringe housing, the direction of the axial movement of the plunger rod 920 can be reversed, i.e., the plunger rod 920 can be moved backward in the direction 944 (e.g., by the electric motor 118) to release the plunger rod 920 from the plunger head, for example, for replacing the used (empty) disposable syringe (102) with a new disposable syringe.

[0107] As the cylindrical cam body 910 moves rearwardly (in direction 944), the cam pin 930 continues its relative travel along the segment 996 of the zigzag channel from the push angle position A4 towards the release angle position A5 through the exit funnel 962 (guided by the exit funnel 962). More specifically, in order for the cam pin 930 to reach the release angle position A5, the cylindrical cam body 910 moves axially in the direction 944 (which is equivalent to moving the cam pin 930 upward relative to the cam body 910 and along the reference line 970) until the cam surface 997 of the pulling member P2” is cam-engaged by the cam pin 930, as Figure 9J shown.( Figure 9J The cam surface 997 of the pulling member P2” cam-engaged by the cam pin 930 is shown.) Then (refer to Figure 9J ), further moving the cylindrical cam body 910 rearwardly in the direction 944 causes the cam surface 997 to act in cam cooperation with the cam pin 930 to cause the cylindrical cam body 910 to rotate again about the axis of rotation 107 in the direction 982 until the cylindrical cam body 910 reaches the release angle position A5, as Figure 9K shown. Refer to Figure 9K , when the cam pin 930 is in the release angle position A5, further rearward movement (in the direction 944) of the plunger rod 920 disengages the cylindrical cam body 910 from the cam pin 930, as Figure 9L shown.

[0108] The front cam surface 980 of the pulling member P1”, the cam surface 984 of the tooth T3”, the rear cam surface 986 of the pulling member P2”, the cam surface 988 of the tooth T4” and the rear cam surface 997 of the pulling member P2” are inclined in such a way that the reciprocating axial movement (942, Figure 9A ) of the plunger rod 920 causes these cam surfaces to act continuously in cam cooperation with the cam pin 930 (i.e., the first front cam surface 980, then the cam surface 984, etc.) to cause the cylindrical cam body 910 to rotate unidirectionally in the direction 576. The cam pin 930 is one of the cam pins described as rotating the cylindrical cam body 910 unidirectionally in the direction 576. However, as described herein and for example Figure 4As shown, the plunger head includes more than one cam pin, and all the cam pins operate in unison to rotate the cylindrical cam body 910 unidirectionally in the direction 576. The unison operation of the cam pins also means that all the cam pins simultaneously enter (engage) the cylindrical cam body through different through channels (through their inlet funnels), then these cam pins travel through similar zigzag segments, and finally simultaneously exit (disengage) the cylindrical cam body through different through channels (through their outlet funnels). The inlet through channel of a particular cam point is the outlet through channel of another cam point. Similarly, the outlet through channel of a particular cam point is the inlet through channel of another cam point.

[0109] Figure 9L Also shown are two cam pins (out of a total of four cam pins), one shown at 930 and the other shown at 932. When the cam pin 930 rotates the cylindrical cam body 910 to enter the cylindrical cam body 910 through the inlet funnel 960 at the engagement angular position (A1), the cam pin 932 simultaneously rotates the cylindrical cam body 910 to enter the cylindrical cam body 910 through the inlet funnel 964 (like the other cam pins, but through a different inlet funnel) at its engagement angular position (A1') simultaneously. The other cam pins travel to their engagement angular positions via similar paths simultaneously. In this way, all the cam pins enter the cylindrical cam body 910 simultaneously.

[0110] When the cam pin 930 rotates the cylindrical cam body 910 to its first push angular position (A2) while traveling to this position via the segment 990 of the guiding zigzag channel, the cam pin 932 rotates the cylindrical cam body 910 cam - wise to its first push angular position (A2') while traveling to this position via the segment 990' of the zigzag channel. The other cam pins travel (in a zigzag) to their push angular positions via similar paths simultaneously. In this way, all the cam pins can be pushed simultaneously by the cylindrical cam body 910, thus pushing the plunger head 106.

[0111] When the cam pin 930 rotates the cylindrical cam body 910 to its pull angular position (A3) while traveling to this position via the segment 992 of the zigzag path, the cam pin 932 rotates the cylindrical cam body 910 to its pull angular position (A3') while traveling to this position via the segment 992' of the zigzag channel. The other two cam pins travel to their pull angular positions via similar paths simultaneously. In this way, all the cam pins can be pulled simultaneously by the cylindrical cam body 910, thus pulling the plunger head 106.

[0112] When the cam pin 930 rotates the cylindrical cam body 910 to its second pushing angle position (A4) while traveling to this position via the segment 994 of the guiding zigzag channel, the cam pin 932 rotates the cylindrical cam body 910 to its second pushing angle position (A4') while traveling to this position via the segment 994' of the zigzag channel. The other two cam pins travel to their pushing angle positions via similar paths simultaneously. In this way, all the cam pins can be pushed by the cylindrical cam body 910 simultaneously, thereby pushing the plunger head 106 for the second time.

[0113] When the cam pin 930 rotates the cylindrical cam body 910 to its disengaging angle position A5 while traveling to this position via the segment 996 of the zigzag channel, the cam pin 932 rotates the cylindrical cam body 910 to its disengaging angle position A5' while traveling to this position via the segment 996' of the zigzag channel. The other cam pins travel to their disengaging angle positions via similar paths simultaneously. In this way, all the cam pins can be disengaged from the cylindrical cam body 910 simultaneously so that the plunger rod 910 can be released from the plunger head 106. Thus, when the cam pin 930 enters the cylindrical cam body 910 through the inlet funnel 960, travels along the zigzag channel including the segments 990, 992, 994 and 998 and leaves the cylindrical cam body 910 via the outlet funnel 962, all the other cam pins do the same simultaneously. For example, the cam pin 932 enters the cylindrical cam body 910 through the inlet funnel 964, travels along a similar zigzag channel including the segments 990', 992', 994' and 996', and then leaves the cylindrical cam body 910 via the outlet funnel 966.

[0114] Referring again to Figure 9A , the pulling member P3” includes a first (outer) stop surface 912, and the tooth T6” includes a stop surface 914. The stop surfaces 912 and 914 are laterally spaced apart (916) such that the stop surface 912 is in front of the stop surface 914 with respect to the rotational direction (576) of the cylindrical cam body 910. The space 916 is selected such that a cam pin entering the cylindrical cam body 910 via the through-channel between the pulling members P2” and P3” will be able to engage the cam surface of the tooth T5” and act in a cam manner together. The space 916 is also selected such that a cam pin located in the pushing recess between the teeth T5” and T6” will be able to engage the inner cam surface 924 of the pulling member P3” and act in a cam manner together.

[0115] Similarly, the pulling member P3” includes a second (inner) stop surface 918, and the tooth T7” includes a stop surface 920. The stop surfaces 918 and 920 are laterally spaced apart (922) such that the stop surface 918 is in front of the stop surface 920 relative to the direction of rotation (576) of the cylindrical cam body 910. A space 922 that may be the same as the space 916 is selected such that a cam pin located in the pulling recess of the pulling member P3” will be able to engage the cam surface of the tooth T6” and act in a cam manner. The space 922 is also selected such that the cam pin will be able to engage the outer cam surface 926 of the pulling member P3” and act in a cam manner. Similarly, a spacing that is the same as the spacings 916 and 922 exists between the two stop surfaces of each pulling member Pi” and the stop surface of the corresponding tooth. The spacing between the stop surfaces allows all cam pins to smoothly pass through a guiding zigzag channel (e.g., the guiding zigzag channel 710).

[0116] For example, the pump device 100 is a four-stroke cycle pump that implements the following four different plunger rod (and thus plunger head) strokes:

[0117] 1. “Engagement and air discharge” stroke (first stroke): The plunger rod 124 is linearly moved out of the retracted (origin) position in the reusable portion 116 of the pump device 100, for example by an electric motor 118, to engage the plunger head 106 at the bottom (proximal end 103) of the syringe housing 102, and continuously push the plunger head 106 to the distal end 105 of the syringe housing 102 to discharge air (as an example) from the syringe 101;

[0118] 2. “Filling” stroke (second stroke): The plunger rod 124 is linearly moved back from the distal end 105 of the syringe housing 102 to the bottom (proximal end 103) of the syringe housing 102 to fill the syringe housing 102 with a medicament (as an example);

[0119] 3. “Delivery” stroke (third stroke): The plunger rod 124 is linearly moved back from the proximal end 103 of the syringe housing 102 to the distal end 105 of the syringe housing 102 to discharge the medicament (as an example) from the syringe housing 102; and

[0120] 4. “Disengagement and retraction” stroke (fourth stroke): The plunger rod 124 is linearly moved backward from the distal end 105 of the syringe housing 102 such that the plunger rod 124 disengages from the plunger head 106 and continuously moves backward all the way to the retracted position in the reusable portion 116 of the pump device 100.

[0121] Thus, the plunger rod 124 (and thus the plunger head 106) passes completely through the syringe 101 four times to complete one full operating cycle of the pump device 100 from the engagement of the plunger rod 124 with the plunger head 106 to the disengagement of the plunger rod 124 from the plunger head 106. As used herein, a "stroke" is the maximum axial distance that the plunger rod (and thus the cylindrical cam body and the plunger head) can travel when the plunger rod moves between a predetermined axial position and another predetermined axial position along the longitudinal axis of the cylindrical syringe housing within the cylindrical syringe housing. In Figures 10A - 10I the example shown, the stroke distance of the plunger rod 124 can be the distance that the plunger rod 124 travels between the proximal end 103 of the syringe housing 102 (or the retracted / origin position of the cylindrical cam body 130) and the distal end 105 of the syringe housing 102. Depending on the use of the pump device, the operating cycle of the pump device can include fewer than four strokes or more than four strokes, and the number of teeth of the serrated crown (and thus the number of pushing recesses), the number of pulling members, and the number of pulling recesses of each pulling member can be set to conform to the selected operating cycle of the pump device.

[0122] Figures 10A - 10I An example nine-step process for operating the pump device 100 according to an example embodiment is shown. (Some of the nine steps can be consolidated into a single step.) The nine-step process generally includes operably engaging a disposable syringe 101 with the reusable portion 116 of the pump device 100, engaging the plunger rod 124 of the pump device 100 with the plunger head 106 of the disposable syringe 101, operating the pump device while the disposable syringe and the reusable portion of the pump device are engaged, and finally disengaging the plunger rod 124 from the plunger head 106 to enable the disposable syringe 101 to be separated from the reusable portion 116 of the pump device. The nine-step operating process of the pump device demonstrates (includes) the four-stroke operating cycle of the pump device 100.

[0123] Figure 10A The first step in the nine-step process of operating the pump device is shown. (This step in the nine-step process of operating the pump device corresponds to Figure 9A , Figure 9A the cylindrical cam body before it engages the plunger head is shown.) In this step, the syringe 101 is attached to the reusable portion 116 of the pump device 100, and the cylindrical cam body 130 is in the retracted / origin position within the reusable portion 116 of the pump device 100, thus disengaged from the plunger head 106.

[0124] Figure 10B The second step in the nine-step process of operating the pump device is shown. (This step in the nine-step process of operating the pump device corresponds to Figure 9E , Figure 9EA cylindrical cam body is shown which, by co - acting with a cam pin, cams (and rotatably) itself into a first push - angle position in the plunger head. ) In this step, the plunger rod 124 extends axially (longitudinally) partially forward in direction 940 to engage the plunger head 106 (lock onto the plunger head 106) by engaging the cylindrical cam body 130 with the cam pins of the plunger head. One of the four cam pins (e.g., cam pin 430) is shown resting in a first push recess in the cylindrical cam body 130, which corresponds to the first push - angle position of the cylindrical cam body 130. At this stage, the plunger rod 124 is located at the proximal end 103 of the syringe 101, ready to expel air from the syringe 101, for example.

[0125] Figure 10C The third step in a nine - step process of operating a pump device is shown. (This step in the nine - step process of operating the pump device also corresponds to Figure 9E , Figure 9E a cylindrical cam body still in its push - angle position in the plunger head is shown. ) In this step, after having traveled a first stroke forward in the syringe 101 (e.g., from the proximal end 103 to the distal end 105 of the syringe 101), the plunger rod 124 extends fully in the syringe 101 (the cam body 130 is at the distal end 105 of the syringe 101) to expel air from the syringe 101 (as an example). At this stage, the plunger rod 124 is almost ready for its second stroke to fill the syringe 101 with a medicament, for example, by moving the plunger rod 124 backward (rearward) in direction 944 (and thus moving the plunger head 106). To start moving the plunger head 106 rearward by the plunger rod 124 in direction 944, the plunger rod 124 must first move backward (944) the distance (distance 946) required to start guiding the cam pin 430 into a pull recess in the cam body 130 so that the cylindrical cam body 130 rotatably aligns itself, by co - acting with the cam pin in a cam - like manner, into a pull - angle position in the plunger head 106.

[0126] Figure 10D The fourth step in a nine - step process of operating a pump device is shown. (This step in the nine - step process of operating the pump device corresponds to Figure 9G , Figure 9GA cylindrical cam body is shown which, in cam fashion (and rotatably), aligns itself to a pull angle position in the plunger head by co - acting with a cam pin. ) In this step, the plunger head 106 is ready to be moved backward by the plunger rod 124 in the direction 944 (from the distal end 105 to the proximal end 103 of the syringe 101) to complete the second stroke (e.g., "filling" stroke) of the plunger rod 124 to pull back the plunger head 106 to, for example, fill the syringe 101 with a medicament.

[0127] Figure 10E The fifth step in a nine - step process of operating a pump device is shown. (This step in the nine - step process of operating the pump device also corresponds to Figure 9G , Figure 9G a cylindrical cam body still in its pull angle position in the plunger head is shown. ) Figure 10E The plunger rod 124 after the second stroke (e.g., "filling" stroke) has been completed is shown. At this stage, the plunger rod 124 is almost ready for its third stroke (e.g., "medicament delivery" stroke) to, for example, expel the medicament from the syringe 101 or prime an infusion set (tubing system) by moving the plunger rod 124 forward in the direction 940 (and thus moving the plunger head 106). To start moving the plunger head 106 forward (in the direction 940) by the plunger rod 124, the plunger rod 124 must first move forward (940) by a distance (distance 946) required to start guiding the cam pin 430 into the second (subsequent) push recess of the cam body 130 such that the cylindrical cam body 130 rotatably aligns itself to a subsequent push angle position in the plunger head 106 by co - acting with the cam pin in cam fashion.

[0128] Figure 10F The sixth step in a nine - step process of operating a pump device is shown. (This step in the nine - step process of operating the pump device corresponds to Figure 9E , Figure 9E a cylindrical cam body which, in cam fashion (and rotatably), aligns itself to a push angle position in the plunger head by co - acting with a cam pin. ) In Figure 10F one of four cam pins (e.g., cam pin 430) is shown resting in the second (subsequent) push recess in the cylindrical cam body 130 which corresponds to the second push angle position of the cylindrical cam body 130. At this stage, the plunger head 106 is still engaged with the cam body 130 and is ready to be moved forward in the direction 940 by the plunger rod 124 to start the third stroke (e.g., "filling", "priming", etc.) of the plunger rod 124 to expel the medicament from the syringe 101 or prime an infusion set.

[0129] Figure 10GShows the seventh step in a nine-step process of operating a pump device. (This step in the nine-step process of operating the pump device also corresponds to Figure 9E , Figure 9E which shows the cylindrical cam body still in its push angle position in the plunger head.) At this stage, after the plunger rod 124 has completed the third stroke (e.g., the "drug delivery" stroke) in the syringe 101 by moving from the proximal end 103 of the syringe 101 to the distal end 105 of the syringe 101, it extends fully into the syringe 101 (the cam body 130 is at the distal end 105 of the syringe 101) to deliver a drug (as an example) from the syringe 101.

[0130] After having traveled the third stroke, the plunger rod 124 is ready to disengage from the plunger head 106 and is ready to retract within the pump device. To disengage the plunger rod 124 from the plunger head 106, the plunger rod 124 moves backward in the direction 944. Moving the plunger rod 124 in the direction 944 causes the cylindrical cam body 130 and the cam pin of the plunger head 106 to act in a cam-like manner together to rotate the cylindrical cam body 130 such that the cylindrical cam body 130 rotatably aligns itself to the disengagement angle position in the plunger head 106, similar to Figure 9K as shown. Once the cylindrical cam body 130 is rotatably aligned to the disengagement angle position in the plunger head 106, further moving the plunger rod 124 backward in the direction 944 disengages the plunger rod 124 from the plunger head 106, similar to Figure 9L as shown.

[0131] Figure 10H Shows the eighth step in a nine-step process of operating a pump device. (This step in the nine-step process of operating the pump device corresponds to Figure 9L , Figure 9L which shows the cylindrical cam body disengaged from an example cam pin of the plunger head.) At this stage, the plunger rod 124 is fully retracted and returned to the retracted position within the reusable portion 116 of the pump device 100 after having completed the fourth stroke (e.g., the "retraction" stroke).

[0132] Figure 10I Shows the ninth step in a nine-step process of operating a pump device, which is or includes removing (948) the syringe 101 from the reusable portion 116 when the plunger rod 124 is in the retracted / origin position within the reusable portion 116. If desired or needed, the removed syringe can be replaced with a new similar disposable syringe.

[0133] The benefits of the pump device of the present invention compared to a conventional pump are at least as follows:

[0134] 1. A quick-release cam mechanism flexibly designed for desired requirements, including the ability to engage a plunger rod with a plunger head by simply moving the plunger rod forward, and the ability to disengage the plunger rod from the plunger head by simply moving the plunger rod backward;

[0135] 2. Reducing the cost of goods sold (COGS) associated with the disposable part (syringe) of the pump device;

[0136] 3. Fewer components inseparably embedded in the disposable part (syringe);

[0137] 4. Improving product sustainability;

[0138] 5. Since the plunger rod (lead screw) is part of the reusable part of the pump device, the propulsion system has higher precision, enabling the pump device to operate with higher precision and smaller or stricter tolerances;

[0139] 6. Capable of designing a circular syringe rather than an oval syringe or a syringe with other shapes;

[0140] 7. Simplifying the assembly process of the disposable part (syringe);

[0141] 8. Supporting or facilitating the prefilled reservoir concept;

[0142] 9. Higher accuracy in lead screw positioning and position monitoring;

[0143] 10. More effective occlusion control due to enhanced control of the position of the lead screw (plunger rod), and

[0144] 11. An improved pharmaceutical delivery system concept.

[0145] As used herein, the articles "a" and "an" are used to refer to one or more than one (e.g., at least one) grammatical object of an item. For example, depending on the context, "element" can mean one element or more than one element. The term "comprising" is used herein to mean the phrase "comprising but not limited to" and is interchangeable with the phrase "comprising but not limited to". Unless the context clearly indicates otherwise, the terms "or" and "and" are used herein to mean the term "and / or" and are interchangeable with the term "and / or". The term "such as" is used herein to mean the phrase "such as but not limited to" and is interchangeable with the phrase "such as but not limited to".

[0146] The exemplary embodiments of the present invention have been thus described such that it will be apparent to those skilled in the art that modifications of the disclosed embodiments will be within the scope of the present invention. Accordingly, alternative embodiments may include functionally equivalent objects / articles. For example, the plunger head and / or the plunger rod and / or the cylindrical cam body may have a different design (e.g., different shape, size, and / or material, different number of cam pins, different number of cam surfaces and / or stop surfaces, different number of pull recesses, different number of push recesses, etc.) from that described herein and shown in the drawings. The features of certain embodiments may be used in conjunction with other embodiments shown herein. The present disclosure is described in connection with a pump device that includes a disposable reservoir (syringe) and a reusable portion. However, the present disclosure may be relevant to other types of "two-part" devices, pumps, syringes, therapeutic drug delivery devices, etc. (e.g., the present disclosure may be implemented by, used in conjunction with, or for other types of "two-part" devices, pumps, syringes, therapeutic drug delivery devices, etc.). Accordingly, the scope of the appended claims need not be limited by the disclosure herein.

Claims

1. A quick-connect release cam mechanism for a pump device, the pump device including a reusable portion and a disposable portion, the cam mechanism comprising: A rotatable cam body including a plurality of cam surfaces, the rotatable cam body being axially attached to a distal end of a plunger rod and being rotatable about the plunger rod, the plunger rod being movable between a retracted position and an extended position in the reusable portion; And A plurality of cam pins located in a plunger head of the disposable reservoir, the plunger head being linearly movable bidirectionally in the disposable reservoir, Wherein the plurality of cam surfaces and the plurality of cam pins are configured to cooperate in a cam manner to rotate the rotatable cam body in and relative to the plunger head to an engagement angular position where the cam body and the plunger head engage and a disengagement angular position where the cam body and the plunger head disengage, and to rotate from the engagement angular position to the disengagement angular position via a series of alternating push-pull angular positions for alternately pushing and pulling the plunger head in the disposable portion, and wherein rotating the rotatable cam body from one angular position to another is achieved by axially reciprocating the plunger rod relative to the plunger head.

2. A mechanism for selecting an operating association between an axially reciprocating plunger rod of a pump device and a plunger head, the plunger head being movable bidirectionally between a first axial position and a second axial position in a syringe and being restricted in the syringe to prevent rotational movement, the mechanism comprising: A cylindrical cam body axially restricted on the axially reciprocating plunger rod and rotatable about the axially reciprocating plunger rod, and being receivable by a single-sided open chamber concentrically formed in the plunger head through a cylindrical wall, the cylindrical cam body including a plurality of spaced-apart cam surfaces circumferentially located on the cylindrical cam body; And A plurality of cam pins projecting equiangularly from the cylindrical wall toward a longitudinal axis of the plunger head, the plurality of cam pins being configured to cooperate with the cylindrical cam body when the plunger rod reciprocates to sequentially pass through the plurality of cam surfaces, thereby rotating the cylindrical cam body in and relative to the chamber to successive different angular positions corresponding to different operating associations between the plunger rod and the plunger head.

3. The mechanism according to claim 2, wherein, When the cam body axially reciprocates in the chamber, the plurality of cam pins cooperate with the cam body to sequentially pass through the plurality of cam surfaces, thereby causing the cam body to rotate unidirectionally relative to the chamber to successive different rotational operating positions during successive operation of the reciprocating plunger rod.

4. The mechanism according to claim 2, wherein, The different operating associations between the plunger rod and the plunger head include: (i) causing the plunger rod to engage with the plunger head when the cam body is axially moved into the chamber by the plunger rod; (ii) When the plunger rod reciprocates axially, the plunger head in the syringe is alternately pushed and pulled by the plunger rod; and (iii) When the cam body axially moves out of the chamber through the plunger rod, the plunger rod is disengaged from the plunger head.

5. The mechanism according to claim 2, wherein The successive different angular positions of the cam body in the chamber include: An engagement angular position at which the cam surface of the cam body abuts against the cam pin and axially moves forward through the plunger rod, so that the plunger rod engages with the plunger head; A disengagement angular position at which the cam body axially moves backward from the chamber through the plunger rod, so that the cam body can be released from the cam pin; and A series of alternating push-and-pull angular positions between the engagement angular position and the disengagement angular position, at which the cam body alternately pushes and pulls the plunger head in the syringe during successive axial reciprocating movement of the plunger rod.

6. The mechanism according to claim 5, wherein, The series of alternating push-and-pull angular positions includes: (i) A first angular position at which the cam body is seated in the plunger head to axially push the plunger head from a first axial position in the syringe to a second axial position in the syringe; (ii) A second angular position after the first angular position, at which the cam body is seated in the plunger head to axially pull the plunger head from the second axial position in the syringe to the first axial position in the syringe; and (iii) A third angular position after the second angular position, at which the cam body is seated again to axially push the plunger head from the first axial position in the syringe to the second axial position in the syringe.

7. The mechanism according to claim 6, wherein, The first angular position is for expelling air from the syringe, the second angular position is for filling the syringe with a medicament, and the third angular position is for expelling the medicament from the syringe.

8. The mechanism according to claim 5, wherein The cylindrical cam body includes: A number "n" of circumferential teeth that are equally angularly spaced at the proximal end of the cam body and form "n" U-shaped pushing recesses for axially pushing the cam pin, thereby axially pushing the plunger head in the syringe; and A number "n / 2" of circumferential pulling members that are equally angularly spaced at the distal end of the cam body, and each pulling member includes a U-shaped pulling recess for axially pulling the cam pin, thereby axially pulling the plunger head in the syringe.

9. The mechanism according to claim 8, wherein Each U-shaped pushing recess is open at an acute angle toward the distal end of the cam body with respect to a line parallel to the longitudinal axis of the cam body, and each U-shaped pulling recess is open at an acute angle toward the proximal end of the cam body with respect to the line parallel to the longitudinal axis of the cam body.

10. The mechanism according to claim 8, wherein, The "n" teeth and the "n / 2" pulling members are arranged on the cylindrical cam body in an alternating relationship such that each odd tooth (Ti) abuts a through-channel formed jointly by two adjacent pulling members (Pi, Pi+1) and formed between the two adjacent pulling members (Pi, Pi+1), and each even tooth (Ti+1) abuts a "U"-shaped pulling recess of a specific pulling member (Pi+1).

11. The mechanism according to claim 10, wherein, The through-channel formed by every two adjacent pulling members and formed between every two adjacent pulling members includes: An inlet funnel configured to rotatably receive a respective one of the plurality of cam pins when the cylindrical cam body is inserted into the chamber and to guide the respective one of the plurality of cam pins to the engagement angle position; and An outlet funnel configured to rotatably receive a respective one of the plurality of cam pins when the cam body is retracted from the chamber and to guide the respective one of the plurality of cam pins away from the disengagement angle position, wherein the inlet funnel and the outlet funnel of each through-channel are longitudinally positioned "back-to-back" such that the narrow openings of the inlet funnel coincide with the narrow openings of the outlet funnel.

12. The mechanism according to claim 11, wherein, The inlet funnel is formed by a pair of conjugate axially forward cam surfaces, the pair of conjugate axially forward cam surfaces including the forward cam surface of a specific pulling member (Pi) and the forward cam surface of a pulling member (Pi+1) adjacent to the specific pulling member (Pi), and wherein the outlet funnel is formed by a pair of conjugate axially rear surfaces, the pair of conjugate axially rear surfaces including the rear cam surface of a specific pulling member (Pi) and the rear surface of an adjacent pulling member (Pi+1).

13. The mechanism according to claim 12, wherein, The number of the through-channels is the same as the number of the cam pins, and wherein each cam pin is configured to abut the inlet funnel of a specific one of the through-channels for inserting the cam body into the chamber of the plunger head and to abut the outlet funnel of a different one of the through-channels for withdrawing the cam body from the chamber of the plunger head.

14. The mechanism according to claim 13, wherein n = 8 and the number of the cam pins is 4.

15. The mechanism according to claim 8, wherein The "n" circumferential teeth form a serrated crown at the proximal end of the cam body, wherein each tooth of the serrated crown is a right triangle-shaped tooth, the right triangle-shaped tooth including a cam surface and a stop surface among the plurality of cam surfaces, and wherein each specific "U"-shaped pushing recess is formed by connecting (bridging) the cam surface of a specific tooth (Ti) and the stop surface of a subsequent tooth (Ti+1) by a bottom surface, and Wherein, each specific pulling member (Pi) includes a first tip and a second tip, the first tip includes a cam surface among the plurality of cam surfaces, and the second tip includes a stop surface, and wherein the "U"-shaped pulling recess in the specific pulling member (Pi) is formed by connecting (bridging) the cam surface and the stop surface of the specific pulling member (Pi) by a bottom surface.

16. The mechanism according to claim 15, wherein, The "n / 2" pulling members axially away from the serrated crown, and thereby define a guiding "zigzag" channel for when the cylindrical cam body rotates from the engaging angular position to the disengaging angular position via the series of alternating push-pull angular positions during the reciprocating movement of the plunger rod, the plurality of cam pins pass through the guiding "zigzag" channel.

17. The mechanism according to claim 15, wherein, The serrated crown includes an annular base at the proximal end of the cam barrel, and the circumferential teeth longitudinally extend at right angles from the plane of the annular base such that all the teeth point to the distal end of the cam body. Wherein, for each tooth, the cam surface is inclined with respect to a line parallel to the longitudinal axis of the cam body, and the stop surface is parallel to the line parallel to the longitudinal axis of the cam body.

18. A pump device for delivering a medicament, comprising: A disposable reservoir, the disposable reservoir comprising: - A plunger head, the plunger head being capable of moving bidirectionally between a first axial position and a second axial position in the disposable reservoir, the plunger head comprising: -- A one-sided open chamber, the one-sided open chamber being concentrically formed in the plunger head by a cylindrical wall, and -- A plurality of cam pins, the plurality of cam pins protruding equiangularly and radially from the cylindrical wall towards the longitudinal axis of the plunger head; and A reusable part, the reusable part comprising: - A plunger rod, the plunger rod being configured for axial reciprocating movement, and - A cylindrical cam body, the cylindrical cam body being axially restricted on the plunger rod and capable of rotating around the plunger rod, and capable of being received by the one-sided open chamber, the cylindrical cam body including a plurality of cam surfaces circumferentially located on the cylindrical cam body. Wherein, the plurality of cam pins are configured to cooperate with the cylindrical cam body when the plunger rod reciprocates axially to sequentially pass through the plurality of cam surfaces to rotate the cylindrical cam body in the one-sided open chamber and relative to the one-sided open chamber to consecutive different angular positions corresponding to different operational associations between the plunger rod and the plunger head.

19. The mechanism according to claim 18, wherein The cam pins are configured to pass through the plurality of cam surfaces of the cam body when the cam body reciprocates axially in the chamber to cause the cam body to rotate unidirectionally relative to the chamber to consecutive different rotational operating positions during consecutive operations of the reciprocating plunger rod.

20. A method of operating a pump device having a plunger rod provided with a rotatable cam body, the method comprising: Join a disposable reservoir provided with a plunger head to a reusable part of the pump device, and when the disposable reservoir and the reusable part of the pump device are joined, Axially move the plunger rod in a reciprocating manner in the disposable reservoir so that the rotatable cam body and the cam pin in the plunger head act in a cam manner together, thereby rotating the rotatable cam body to an engagement angular position where the plunger rod engages with the plunger head, and then through a series of alternating push-pull angular positions corresponding to a series of alternately pushing forward and pulling backward the plunger head in the disposable reservoir, and then rotating to a disengagement angular position where the plunger rod can disengage from the plunger head.

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