Low input pressure lung demand regulator

Abstract

A demand regulator for a breathing apparatus includes a main lever arm including a cam element having a first profile and a second profile, the main lever arm being pivotable; and a valve configured to regulate a flow of breathing gas through the demand regulator, the valve including a valve member displaceable to regulate the flow of breathing gas; wherein the cam element of the main lever arm is configured to displace the valve member during pivoting of the main lever arm; and wherein pivoting of the main lever arm past a first arc corresponding to the first profile of the cam element displaces the valve member at a first displacement rate; and pivoting the main lever arm through a second arc corresponding to the second profile of the cam element displaces the valve member at a second displacement rate; the second displacement rate is different from the first displacement rate. A breathing apparatus including a demand regulator, a diaphragm actuated lever arm for a demand regulator, and a method for designing a cam element profile are also disclosed.

Description

Technical Field

[0001] This disclosure relates to lung demand regulators, and more specifically, to lung demand regulators for use in respiratory devices. Background Art

[0002] Self-contained breathing apparatus (SCBA) typically consists of a lung demand regulator (also known as a LDR, "demand regulator," or "regulator") and a mask. The LDR is attached to the mask to provide the user with breathable air as needed. SCBA systems are often used by factory workers or emergency service personnel such as firefighters, and are therefore frequently exposed to environments containing harmful contaminants such as fumes or toxic chemicals. Typically, the LDR used in SCBAs is configured in "positive pressure" mode to prevent any environmental contaminants from entering the SCBA system.

[0003] In some situations, the pressure of the breathing gas supplied to the LDR may fluctuate. For example, the pressure in a pressurized gas distribution system (e.g., a loop trunk line) in a plant may fluctuate depending on its location within the system and the needs of each node, or the pressure of the breathing gas cylinder may gradually decrease as the cylinder is depleted. When the pressure of the breathing gas entering the LDR drops below a specified level, there is a risk that the pressure inside the mask may become negative relative to ambient air pressure. Negative pressure in the mask puts the SCBA user at risk because environmental contaminants may be inhaled into the mask. Therefore, it should be understood that improvements to existing LDR designs are necessary. Summary of the Invention

[0004] In a first aspect, a demand regulator for a breathing apparatus is provided, comprising: a main arm including a cam element having a first profile and a second profile, the main arm being pivotable; and a valve configured to regulate the flow rate of breathing gas flowing through the demand regulator, the valve including a displaceable valve member for regulating the flow rate of breathing gas; wherein the cam element of the main arm is configured to displace the valve member during pivoting of the main arm; and wherein pivoting of the main arm through a first arc corresponding to the first profile of the cam element displaces the valve member at a first displacement rate; and pivoting of the main arm through a second arc corresponding to the second profile of the cam element displaces the valve member at a second displacement rate; the second displacement rate is different from the first displacement rate. The second displacement rate may be higher than the first displacement rate.

[0005] The pivoting of the main rod arm through the first arc corresponding to the first profile of the cam element should be understood as meaning that during the rotation of the main rod arm through the first arc, the first profile of the cam element displaces the valve member. Similarly, the pivoting of the main rod arm through the second arc corresponding to the second profile of the cam element should be understood as meaning that during the rotation of the main rod arm through the second arc, the second profile of the cam element displaces the valve member.

[0006] It should be understood that the valve member can act as a cam follower to follow a first and second profile of the cam element during rotation or pivoting of the main lever arm. Alternatively, a linkage can be provided to transmit motion of the cam follower to the valve member. This linkage can be a secondary lever arm that includes the cam follower. Pivoting of the main lever arm in a first direction (e.g., counterclockwise) can cause the secondary lever arm to pivot in the opposite direction (e.g., clockwise). The cam element of the main lever arm can contact the secondary lever arm.

[0007] It should be understood that a valve member may be associated with a cam element. The valve member may be in direct or indirect contact with the cam element. The valve may also include a piston associated with the valve member. The piston may be arranged between the valve member and the main rod arm, or (in the case of a secondary rod arm) between the valve member and the secondary rod arm. The reference to "indirect contact" may mean that one component engages with another component without physical contact. For example, indirect contact between the valve member and the cam element may mean that the valve member is connected to and / or can engage with the cam element without physical contact.

[0008] During the pivoting of the main arm, the valve component can be displaced radially relative to the axis of rotation of the main arm. The magnitude of the displacement corresponds to the effective radial thickness of the cam element at the point where the cam element connects to the valve component.

[0009] The displacement rate can be the rate of change of the displacement of the valve component relative to the pivoting rate of the main lever arm. The pivoting rate of the main lever arm can be considered as the angular velocity of the main lever arm. The displacement rate can be constant (i.e., linear) across each corresponding profile of the cam element, or it can vary with the rotation of the main lever arm.

[0010] The valve component can be configured to form an airtight seal against a sealing seat included in the valve when the valve component is in its minimum displacement state.

[0011] The pivoting of the main arm through the first arc corresponds to the pivoting of the main arm between the first and second rotation angles; and the pivoting of the main arm through the second arc corresponds to the pivoting of the main arm between the third and fourth rotation angles.

[0012] Each of the first to fourth rotation angles can be measured about the axis of rotation of the main arm. Each of the second to fourth rotation angles can be measured from a first position on the longitudinal axis of the main arm. This first position can correspond to the first rotation angle. The first rotation angle can be set to zero degrees (i.e., the initial position of the main arm). Each of the first to fourth rotation angles can be different. The magnitude of each of the first to fourth rotation angles can gradually increase. The second and third rotation angles can be equal.

[0013] It should be understood that pivoting the master arm through the first arc means pivoting the master arm from the first rotation angle to the second rotation angle (or from the second rotation angle to the first rotation angle). It should be understood that pivoting the master arm through the second arc means pivoting the master arm from the third rotation angle to the fourth rotation angle (or from the fourth rotation angle to the third rotation angle).

[0014] It should be understood that during the pivoting of the main arm through the first arc, the valve member is associated with the first profile of the cam element, thereby displacing the valve member according to the first profile. It should be understood that during the pivoting of the main arm through the second arc, the valve member is associated with the second profile of the cam element, thereby displacing the valve member according to the second profile.

[0015] The main lever can be configured to pivot through a first arc when the breathing gas input to the demand regulator is above a threshold pressure. The main lever can also be configured to pivot through a second arc when the breathing gas input to the demand regulator is below a threshold pressure.

[0016] "Configured to pivot through the first arc" should be understood as meaning that when the pressure of the input breathing gas is higher than the threshold pressure, the main lever arm can pivot to any point on the first arc and / or between any points on the first arc. "Configured to pivot through the second arc" should be understood as meaning that when the pressure of the input breathing gas is lower than the threshold pressure, the main lever arm can pivot to any point on both the first and second arcs and / or between any points on both the first and second arcs.

[0017] When the pressure of the input breathing gas is higher than the threshold pressure, the first profile of the cam element (corresponding to the first arc through which the main lever arm pivots) can displace the valve member during the first arc of the main lever arm pivoting. When the pressure of the input breathing gas is lower than the threshold pressure, the second profile of the cam element (corresponding to the second arc through which the main lever arm pivots) can displace the valve member during the second arc of the main lever arm pivoting. The threshold pressure can be between 300 kPa and 600 kPa, optionally between 400 kPa and 500 kPa, and further optionally, can be 450 kPa.

[0018] References to “above” and “below” thresholds in this document may include “equal to or above” and “equal to or below”, respectively.

[0019] The first profile and the second profile can be convex. The first profile can be an arch with a first radius, and the second profile can be an arch with a second radius. The first radius can be different from the second radius.

[0020] An arched shape should be understood as a portion of the circumference of a circle. Therefore, it should be understood that the first cam profile and the second cam profile can each take the shape of a portion of the circumference of a circle, and each cam profile has a given first radius and second radius. The first radius and the second radius can be the same or different. The first radius can be larger than the second radius. The first radius can be smaller than the second radius.

[0021] The first and second contours may intersect at a transition point. This transition point can be a continuous or discontinuous transition point. The transition point can be a smooth / continuous transition point between the first and second contours. The transition point can also be a discontinuous transition point.

[0022] The demand regulator may also include a secondary lever arm disposed between the cam element and the valve member. The secondary lever arm may be configured to transmit motion of the cam element to the valve member. The secondary lever arm may be an adjustable lever arm configured to adjustably change the proportion of motion transmitted from the cam element to the valve member. The adjustable lever arm may include an adjusting screw.

[0023] The adjusting screw can change the effective thickness of the adjustable lever arm. Adjusting the effective thickness of the adjustable lever arm can apply a displacement offset to the displacement transmitted from the cam element to the valve member. The adjusting screw may or may not be accessible from the outside of the demand regulator. The user may or may not be able to access and / or configure the adjusting screw.

[0024] The demand regulator may further include: a body defining an internal cavity; and a diaphragm disposed within the body. A first side of the diaphragm may communicate with the internal cavity, and a second side of the diaphragm may communicate with the surrounding environment. A main arm may be configured to abut or otherwise contact the diaphragm. A pressure drop in the internal cavity may cause the diaphragm to bend toward the internal cavity, thereby pivoting the main arm. The diaphragm may be configured to bend toward and / or away from the internal cavity according to the pressure difference across the diaphragm. The pressure difference across the diaphragm should be understood as the pressure difference between the first and second sides of the diaphragm.

[0025] It should be understood that when breathing gas with a pressure greater than the ambient pressure is introduced into the demand regulator, a pressure differential can form across the diaphragm. This pressure differential can correspond to the input breathing gas pressure. A higher or lower input breathing gas pressure can correspond to a higher or lower pressure differential, respectively.

[0026] It should be understood that the pressure differential can (at least partially) correspond to the degree to which the diaphragm is pushed toward and / or away from the internal cavity. When the pressure differential across the diaphragm is high, the pressure drop caused by the user's demand-based inhalation may result in less movement of the diaphragm toward the internal cavity compared to a lower pressure differential across the diaphragm. The body may house the valve components. The body may house the auxiliary rod. The diaphragm may be an adjustable diaphragm, wherein the degree to which the diaphragm is pushed toward the internal cavity due to pressure reduction is adjustable.

[0027] In a second aspect, a breathing device is provided, comprising a regulator according to the needs of the first aspect. The breathing device may include a mask, a breathing gas canister, a first-stage breathing circuit, a second-stage breathing circuit, and / or one or more pressure regulators.

[0028] In a third aspect, a diaphragm actuation lever arm for a demand regulator is provided, comprising: a cam element for displacing a valve of the demand regulator, the cam element including a first cam profile and a second cam profile; and a diaphragm contact portion configured to transmit motion of the diaphragm to the diaphragm actuation lever arm, thereby pivoting the diaphragm actuation lever arm; wherein the lever arm pivots via a first arc corresponding to the first cam profile to displace the valve at a first displacement rate; and the lever arm pivots via a second arc corresponding to the second cam profile to displace the valve at a second displacement rate different from the first displacement rate.

[0029] The diaphragm actuation lever arm may include a pivot located at its proximal end. A diaphragm contact portion may be located at the distal end of the diaphragm actuation lever arm. The diaphragm contact portion may abut against the diaphragm. The diaphragm contact portion may be the foot of the diaphragm actuation lever arm. The diaphragm contact portion allows the diaphragm actuation lever arm to rotate about the pivot in response to movement of the diaphragm. A cam element may be located close to the pivot. The cam element may be positioned between the pivot and the diaphragm contact portion.

[0030] In a fourth aspect, a method is provided for designing a cam element profile for a demand regulator lever arm, the demand regulator including a valve member, the cam element profile being configured to displace the valve member, the method comprising the steps of: determining a first peak breathing gas flow rate at a first breathing gas input pressure at a plurality of different valve member displacements, thereby determining a first flow-displacement profile; determining a first minimum required peak flow rate at the first breathing gas input pressure; determining a first minimum valve displacement providing the first minimum required peak flow rate based on the first flow-displacement profile; and determining a first cam profile included in the cam element profile, the first cam profile displacing the valve member at least to the first minimum valve displacement over the entire first pivot arc of the lever arm. The method may be a computer-implemented method. The method may further include: manufacturing a lever arm including the determined cam element profile. The method may further include: outputting data comprising a 3D design model including the determined cam element profile, such as a CAD model, an additive manufacturing model, and / or additive manufacturing instructions. The 3D design model may include data indicating the determined cam element profile or indicating a lever arm including the determined cam element profile.

[0031] This method can be repeated once or multiple times. When repeating the method, the cam element profile designed in the previous method can be used to determine the first flow-displacement curve, the minimum required peak flow rate, and / or the minimum valve displacement in the subsequent method. In this way, the design of the cam element profile can be iteratively improved and / or optimized.

[0032] The method may further include the following steps: determining a second peak breathing gas flow rate at the second breathing gas input pressure under the aforementioned plurality of different valve member displacements, thereby determining a second flow-displacement curve; determining a second minimum required peak flow rate at the second breathing gas input pressure; determining a second minimum valve displacement providing the second minimum required peak flow rate based on the second flow-displacement curve; and determining a second cam profile included in the cam element profile, the second cam profile causing the valve member to be displaced at least to the second minimum valve displacement over the entire second pivot arc of the lever arm. Attached Figure Description

[0033] The arrangement of the present invention will now be described by way of example and with reference to the accompanying drawings, in which:

[0034] Figure 1 A schematic diagram of a breathing device according to an exemplary arrangement is shown, the breathing device including a breathing mask and a demand regulator;

[0035] Figure 2 A schematic diagram of a face mask connected to a demand regulator according to the present invention is shown;

[0036] Figure 3 It shows Figure 2 The demand regulator shown is a cross-sectional view (cut along AA).

[0037] Figures 4A to 4C An embodiment of the main arm according to the invention is shown, which is in different pivot positions;

[0038] Figures 5A to 5C Some other embodiments of the main strut according to the invention are shown; and

[0039] Figure 6 A block diagram of the method according to the present invention is shown. Detailed Implementation

[0040] As discussed above, existing regulators are prone to performance degradation and increased safety risks when faced with lower breathing gas input pressures. When a regulator receives lower-pressure breathing gas, the user's inhalation is likely to cause a period of negative pressure (i.e., pressure below ambient pressure) inside the regulator and / or mask. This negative pressure increases the risk of harmful environmental contaminants being inhaled into the regulator and / or mask, thus endangering the user.

[0041] A lower breathing gas input pressure typically means that the breathing gas pressure is lower than the commonly used or "designed" breathing gas input pressure. In other words, a lower breathing gas input pressure can indicate that the breathing gas pressure is lower than the operating pressure that the demand regulator is designed to operate at during normal use.

[0042] To date, few solutions have attempted to overcome these drawbacks. Notably, US 6,729,331B2 appears to disclose a pressure regulator comprising a diaphragm whose bias can be adjusted via a load spring and a knob. By adjusting the diaphragm bias, the pressure regulator can be adapted to handle lower input breathing gas pressures while maintaining positive pressure within the regulator. However, this regulator exhibits several significant limitations. First, the load spring must be manually adjusted by the user. This adjustment requires precise hand movements, which are difficult or even impossible to perform while wearing heavy gloves or engaging in strenuous activity. Furthermore, the user must distract themselves at the right time to carefully adjust the knob to ensure their safety. In critical situations (e.g., when the user is a firefighter responding to an emergency), such distraction from the task at hand may be unsafe. Indeed, even if the user is able to distract themselves, they must adjust at the appropriate time to ensure the diaphragm bias closely corresponds to the input breathing gas pressure. Otherwise, the user faces the risk of exposure to harmful environmental contaminants.

[0043] Secondly, the load spring and knob introduce other problems: manufacturing tolerances and variations can significantly affect the regulator's performance. Even minor differences in the dimensions of the load spring and / or knob can have a significant impact on the accuracy of any adjustments made by the user. These additional components can also be affected by the unpredictable environment in which the regulator is used. In particular, the bias provided by the load spring may change independently of any adjustments made by the user due to variations in ambient temperature, further endangering the user's health.

[0044] As will be briefly described through various exemplary embodiments, the present invention provides an improvement over known pressure regulators.

[0045] refer to Figure 1 An exemplary breathing device 10 is shown. The breathing device 10 is a self-contained breathing apparatus (SCBA) and includes a support frame or backplate 12, straps 14 for securing the SCBA to a user, a breathing gas cylinder 16, a face mask 18, a lung demand regulator 100 connectable to the face mask 18, and a pneumatic system 20 for delivering breathing gas from the cylinder 16 through a hose or flexible tubing 22 to the lung demand regulator 100, thereby delivering breathing gas to the user wearing the face mask 18 as needed. The breathing device 10 may also include other components or systems (not shown), including but not limited to electrical systems, monitoring systems, or communication systems. The lung demand regulator 100 is referred to as regulator 100 throughout this specification.

[0046] In the illustrated arrangement, breathing equipment 10 is a self-contained breathing apparatus (SCBA), but it should be understood that lung demand regulators can also be applied to other types of breathing apparatus, such as self-contained underwater breathing apparatus (SCUBA) and emergency escape breathing apparatus.

[0047] Go to Figure 2 A schematic diagram of a mask 18 attached to regulator 100 is shown. A hose 22 of pneumatic system 20 is connected to inlet 101 of regulator 100 to supply breathing gas from cylinder 16. Pneumatic system 20 may include a first-stage pressure reducer to an intermediate pressure, which may reduce the pressure of the breathing air stored in the cylinder at several hundred bar to allow for supply via hose 22 to regulator 100. This intermediate pressure may be too high to supply breathing gas directly to the user for breathing. Regulator 100 may also include a second-stage pressure reducer to further reduce the pressure of the breathing gas to a pressure suitable for delivery to the user for breathing. In other arrangements, more than two or fewer pressure reducers may be provided. In some arrangements, regulator 100 is connected to a pressurized breathing gas circuit for use by workers, such as in a factory. In this case, breathing gas can be supplied by the circuit at a breathable pressure, so a pressure reducer may not be necessary.

[0048] Figure 3 The regulator 100 is shown along the line. Figure 2 The cross-sectional view is taken from the face marked "AA". The regulator 100 includes a body 104, a diaphragm 102, a main rod arm 200, and a valve 300. In the illustrated embodiment, the diaphragm 102 is a thin, flexible, and waterproof membrane fixed to the body 104. One side of the diaphragm 102 is exposed to the surrounding environment and therefore to ambient air pressure. The other side of the diaphragm 102 is exposed to an internal cavity 103 formed in the body 104 of the regulator 100.

[0049] Because the diaphragm 102 is made of a flexible material, any difference between the ambient air pressure and the pressure in the internal cavity 103 will cause the diaphragm 102 to bend. When the ambient pressure is greater than the pressure in the internal cavity 103, the diaphragm 102 bends inward toward the internal cavity 103. When the ambient pressure is less than the pressure in the internal cavity 103, the diaphragm 102 bends outward away from the internal cavity 103. The greater the difference between the ambient pressure and the pressure in the internal cavity 103, the greater the degree of bending of the diaphragm 102.

[0050] The main lever arm 200 includes a pivot point 210 about which the main lever arm 200 can pivot. The main lever arm 200 communicates with a valve 300, and the pivoting of the main lever arm 200 actuates the valve 300 (described in more detail later) to control the introduction of pressurized breathing gas into the internal cavity 103. The main lever arm 200 also includes a foot 201 located at one end of the main lever arm 200 away from the pivot point 210. The foot 201 contacts the diaphragm 102. In the illustrated embodiment, the foot 201 contacts a generally central portion of the diaphragm 102. The foot 201 can be positioned at an angle relative to the main lever arm 200. When the diaphragm 102 bends inward toward the internal cavity 103, the diaphragm 102 pushes the foot 201, thereby pivoting the main lever arm 200 about the pivot point 210.

[0051] according to Figure 3In the view shown, when the diaphragm 102 bends inward, the main rod arm 200 pivots counterclockwise about the pivot point 210. It should be understood that the degree of pivoting of the main rod arm 200 about the pivot point 210 corresponds to the degree of inward bending of the diaphragm 102. Therefore, when the ambient air pressure is significantly greater than the pressure in the internal cavity 103, the diaphragm 102 will bend significantly inward, causing the main rod arm 200 to pivot significantly about the pivot point 210. Similarly, when the ambient air pressure is slightly greater than the pressure in the internal cavity 103, the diaphragm 102 will bend slightly inward, causing the main rod arm 200 to pivot slightly about the pivot point 210. When the foot 201 is not in contact with the diaphragm 102, the main rod arm 200 can be biased (e.g., biased by the valve 300) and pivot clockwise. Therefore, when the diaphragm 102 bends inward and causes the main rod arm 200 to pivot counterclockwise and then bend outward, the bias causes the main rod arm 200 to pivot clockwise until the foot 201 returns to contact the diaphragm 102.

[0052] When regulator 100 is connected to mask 18, the internal cavity 103 of regulator 100 is in fluid communication with the internal cavity of mask 18. Therefore, when the user wears mask 18, the user's inhalation causes a decrease in pressure within internal cavity 103. This pressure decrease causes diaphragm 102 to move inward, thereby pivoting master arm 200. The pivoting of master arm 200 causes valve 300 to open, allowing breathing gas to be introduced into internal cavity 103 for the user to inhale. As breathing gas is introduced, the pressure within internal cavity 103 increases and eventually causes diaphragm 102 to bend outward, allowing master arm 200 to pivot back to its original position due to bias.

[0053] The amount of air a user breathes each time is typically roughly the same. Therefore, the degree to which the diaphragm 102 bends inward during inhalation generally depends on the ambient pressure (which is usually relatively constant) and the pressure of the breathing gas introduced into the internal cavity 103. The pressure of the introduced breathing gas is typically between 140 kPa and 900 kPa. When the input breathing gas pressure is higher (e.g., between 450 kPa and 900 kPa), the degree to which the diaphragm 102 bends inward during inhalation is less significant, while when the input breathing gas pressure is lower (e.g., between 140 kPa and 450 kPa), the degree to which the diaphragm 102 bends inward during inhalation is more significant. When the input breathing gas pressure is higher and the user inhales, the pressure difference between the internal cavity 103 and the ambient air pressure is smaller than when the input breathing gas pressure is lower and the user inhales. Therefore, when the input breathing gas pressure is higher, the main arm 200 pivots less due to the bending of the diaphragm 102 compared to when the input breathing gas pressure is lower. Therefore, the degree of pivoting of the main arm 200 can be considered to be at least partially negatively correlated with the pressure of the input breathing gas.

[0054] like Figure 3 As shown, the main lever arm 200 includes a cam element 220 near the pivot point 210. The cam element 220 is formed by a proximal portion of the main lever arm 200 (enlarged in this example) and a surface surrounding the proximal portion, which is configured to actuate the valve 300 (either via direct or indirect contact, such as via a connecting rod) as the main lever arm 200 pivots.

[0055] The main lever arm 200 can directly contact the valve 300. In this case, the cam element 220 of the main lever arm 200 can directly contact the piston 310 of the valve 300. In this embodiment, as the main lever arm 200 pivots, the cam element 220 pushes the piston 310. Thus, the piston 310 acts as a cam follower and moves laterally to lift the valve member 320 away from the sealing seat 330, thereby allowing pressurized breathing gas to flow through the valve member 320 and into the internal cavity 103. In other embodiments, including Figure 3In the illustrated embodiment, the main lever arm 200 can indirectly engage the piston 310 of the valve 300. In this case, a secondary lever arm 400 can be provided to form a link between the cam element 220 of the main lever arm 200 and the piston 310. The secondary lever arm 400 may include a secondary pivot point 410 about which the secondary lever arm 400 can pivot. The secondary pivot point 410 can be arranged to be offset relative to the pivot point 210 of the main lever arm 200. As in the illustrated embodiment, the secondary lever arm 400 can be configured to pivot in a direction opposite to the pivot direction of the main lever arm 200. Thus, as the main lever arm 200 pivots counterclockwise, the cam element 220 can contact the secondary lever arm 400 and cause the secondary lever arm 400 to pivot clockwise. In some embodiments, the secondary lever arm 400 is an adjustable lever arm 400. For example, in the illustrated embodiment, the secondary lever arm 400 includes an adjusting screw 420 that can be adjusted to change the effective thickness of the secondary lever arm 400. By adjusting the effective thickness of the adjustable lever arm, a "displacement offset" is applied to the displacement transmitted from the cam element 220 of the primary lever arm 200 to the piston 310. Thus, the secondary lever arm 400 can be used to change the angle at which the primary lever arm 200 must pivot in order to lift the valve member 320 from the seal seat 330.

[0056] Valve 300 may also include a biasing element 340, such as a spring. Once the dynamic pressure of the breathing gas moving through valve 300 (relative to the pressure of the internal cavity 103) is no longer sufficient to keep valve 300 open, the biasing element 340 biases valve member 320 back to sealing seat 330. In the process, this bias also causes main rod arm 200 to pivot clockwise about pivot point 210.

[0057] Now go to Figures 4A to 4C For ease of understanding, the cam element 220 of the master lever 200, the secondary lever 400, and the piston 310 are shown separately and in more detail. As shown in the figures, the cam element 220 includes a first profile 222 and a second profile 224. The arrow marked X indicates the displacement of the secondary lever 400 relative to the pivot point 210. The cam element engagement point 221 indicates the position where the cam element 220 engages (in this example, contacts) with the secondary lever 400. The plunger engagement point 223 indicates the position where the secondary lever 400 engages (in this example, contacts) with the piston 310. Therefore, the cam element engagement point 221, the plunger engagement point 223, the first profile 222, and the second profile 224 define the degree to which the valve 300 is actuated. It is noteworthy that throughout the entire pivot range of the master lever 200, the cam element engagement point 221 moves further away from the pivot point 210 (indicated by arrow X, its length is within...). Figures 4A to 4C(The rotation gradually increases). Therefore, the pivoting of the main lever arm 200 throughout its entire range of motion causes the rotation of the secondary lever arm 400 to continuously increase, thereby causing the displacement of the valve 300 via the piston 310 to continuously increase.

[0058] It should be understood that in some embodiments where the piston 310 directly contacts the cam element 220, the cam element engagement point 221 and the plunger engagement point 223 may be the same point on the cam element 220.

[0059] When the main lever arm 200 pivots about the pivot point 210, the cam element 220 contacts the secondary lever arm 400, which pushes the piston 310, thereby opening the valve 300. Figure 4A The primary lever arm 200 is shown in its initial position, corresponding to the unbent position of the diaphragm 102. Initially, the first profile 222 of the cam element 220 contacts the secondary lever arm 400 (indicated by the position of the cam element engagement point 221). As the primary lever arm 200 pivots due to the inward bending of the diaphragm 102 (as... Figure 4B As shown in the diagram, the cam element engagement point 221 moves along the first profile 222. During this pivoting process, the shape of the first profile 222 determines the pivoting rate of the secondary lever arm 400 (relative to the pivoting rate of the primary lever arm 200), thereby determining the displacement rate of the piston 310. Therefore, the shape of the first profile 222 determines the rate at which the valve member 320 moves away from the seal seat 330. When the cam element engagement point is located on the first profile 222, the position through which the primary lever arm 200 can pivot can be considered to form a "first arc". In other words, the pivoting of the primary lever arm 200 through the first arc corresponding to the first profile 222 causes the valve member 320 to shift at a first displacement rate.

[0060] As the main boom 200 further pivots (as... Figure 4C As shown in the diagram, the cam element engagement point 221 moves across the first profile 222 and onto the second profile 224. As the cam element engagement point 221 moves along the second profile 224, the second profile 224 determines the rate at which the valve member 320 moves away from the seal seat 330. When the cam element engagement point 221 is located on the second profile 224, the position through which the master arm 200 can pivot can be considered to form a “second arc.” In other words, the pivoting of the master arm 200 through the second arc corresponding to the second profile 224 causes the valve member 320 to shift at a second displacement rate. The first profile 222 is typically different from the second profile 224. Therefore, the first displacement rate and the second displacement rate are typically different. In some embodiments, the second displacement rate is higher than the first displacement rate.

[0061] The first arc can be considered as representing the angular range through which the main arm 200 pivots. Therefore, pivoting the main arm 200 through the first arc can be defined as the main arm 200 pivoting about the pivot point 210 between a first rotation angle and a second rotation angle. Similarly, the second arc can be considered as representing the angular range through which the main arm 200 pivots. Therefore, pivoting the main arm 200 through the second arc can be defined as the main arm 200 pivoting about the pivot point 210 between a third rotation angle and a fourth rotation angle. In some embodiments, the second and third rotation angles are the same, meaning that the first profile 222 and the second profile 224 intersect at a transition point (described in more detail later).

[0062] As discussed above, when the breathing gas introduced into the internal cavity 103 is at a higher pressure (e.g., above the threshold pressure between 300 kPa and 600 kPa), compared to when the breathing gas introduced into the internal cavity 103 is at a lower pressure (e.g., below the threshold pressure between 300 kPa and 600 kPa), the user's inhalation causes the main lever arm 200 to pivot to a less extent. Therefore, the main lever arm 200 and the cam element 220 are arranged such that when the pressure of the input breathing gas is above the threshold (e.g., at least 450 kPa), the main lever arm 200 pivots through a first arc (corresponding to the first profile 222). Therefore, the main lever arm 200 and the cam element 220 are also arranged such that when the pressure of the input breathing gas is below the threshold (e.g., approximately 450 kPa), the main lever arm 200 pivots through the first arc and then through a second arc (corresponding to the second profile 224). Thus, when the breathing gas is at a higher pressure, the shape of the first contour 222 controls the introduction of the breathing gas, while when the breathing gas is at a lower pressure, the second contour 224 controls the introduction of the breathing gas.

[0063] In some embodiments, the first displacement rate and / or the second displacement rate are constant (i.e., linear) along the corresponding first profile and / or second profile. In some embodiments, the first displacement rate and / or the second displacement rate vary with the position of the main arm 200.

[0064] The pressure (i.e., the threshold pressure) that moves the cam element engagement point 221 from the first profile 222 to the second profile 224 can be set according to the design requirements of the regulator 100 and the breathing device 10 and possible usage scenarios. The threshold pressure is typically slightly lower than the commonly used (or anticipated) breathing gas pressure available to the regulator 100 during use. As mentioned above, the threshold pressure can be between 300 kPa and 600 kPa. In some embodiments, the threshold pressure is approximately 450 kPa. Thus, when the pressure of the input breathing gas is higher than 450 kPa, the first profile 222 determines the displacement rate of the valve member 320, while when the pressure of the input breathing gas is lower than 450 kPa, the second profile determines the displacement rate of the valve member 320.

[0065] In some embodiments, the second profile 224 corresponds to a greater displacement rate of the valve member 320 compared to the first profile 222. Thus, when the input breathing gas is at a lower pressure, the valve 300 will open further. Since the user's breathing rate is generally relatively stable between breaths, further opening of the valve 300 means a longer total open time. The combination of further opening of the valve 300 and a longer open time allows more breathing gas to enter the internal cavity 103 during each inhalation. The introduced additional breathing gas advantageously prevents any period of negative pressure formation within the cavity 103. Therefore, the invention advantageously enables the regulator 100 to operate normally when the input breathing gas pressure is at the expected value and prevents potentially harmful contaminants from being inhaled into the regulator 100 and / or the mask 18 when the input breathing gas pressure is below the optimal and / or expected pressure. The invention achieves these benefits by automatically adjusting the amount of breathing gas introduced into the regulator 100 according to the pressure of the breathing gas.

[0066] In some embodiments, the first profile 222 and / or the second profile 224 are convex on the surface of the cam element 220. In some embodiments, the first profile 222 and / or the second profile 224 are arched and have a first radius and a second radius, respectively. In some embodiments, the first radius and the second radius are the same, but the centers of the arcs of each profile do not coincide. In some embodiments, the first radius and the second radius are different, and the centers of the arcs of each profile do not coincide. When the first radius and the second radius are different, the first radius may be smaller than the second radius. When the centers of each arc do not coincide, the center of the first arc may be radially closer to the pivot point 210 than the center of the second arc.

[0067] In some embodiments, the first profile 222 and the second profile 224 intersect at a continuous transition point on the surface of the cam element 220. In some embodiments, the first profile 222 and the second profile 224 intersect at a discontinuous transition point on the surface of the cam element 220. A continuous transition point is a point where the tangent of the first profile 222 at its endpoint is collinear with the tangent of the second profile 224 at its starting point. A discontinuous transition point is a point where the tangent of the first profile 222 at its endpoint is not collinear with the tangent of the second profile 224 at its starting point (but may intersect).

[0068] While the invention applies to the regulator 100 and breathing device 10 discussed, it also depends on the main lever arm 200 itself. It should be understood that the main lever arm 200, including a cam element having a first profile 222 and a second profile 224, is suitable for many different types of regulators 100, and the application of the main lever arm 200 in such regulators enables the realization of the benefits of the invention.

[0069] Figures 5A to 5C Other implementations of the main boom are shown. Figure 5A A main lever arm including a cam element 520 is shown. The first profile 522 and the second profile 524 of the cam element are similar to the first profile 222 and the second profile 224 discussed above, but with different shapes. The different shapes of the first profile 522 and the second profile 524 enable the valve member to have different displacement rates for use in other suitable regulators (not shown).

[0070] Figure 5B Another embodiment of the cam element 540 is shown, which also includes a first profile 542 and a second profile 544. The cam element 540 in this embodiment further includes a third profile 546. The third profile 546 provides a displacement rate different from that of both the first profile 542 and the second profile 544. In some embodiments, the displacement rate provided by the third profile 546 may be greater than that provided by both the first profile 542 and the second profile 544. When the breathing gas pressure is particularly low, embodiments including a cam element having more than two profiles can be used to further increase the flow rate of breathing gas entering the regulator.

[0071] Figure 5C Another embodiment of the cam element 560 is shown, which is similar to Figure 5BThe embodiment shown is illustrated. The shapes of the first profile 562, second profile 564, and third profile 566 of the cam element 560 are different from the shapes of the first profile 542, second profile 544, and third profile 546 of the cam element 540 described above. Notably, the radius of the arch of the third profile 566 of the cam element 560 is larger than the radius of the arch of the third profile 546 of the previous cam element 540.

[0072] It should be understood that many different shapes and designs of cam elements are suitable for the main lever arm according to the present invention. The shape of the cam element can be determined according to the intended application (e.g., the intended operating pressure) of each type of regulator.

[0073] Go to Figure 6 A block diagram of a method 600 according to an embodiment of the present invention is shown. Method 600 can be a computer-implemented method, wherein the steps of method 600 are all executed by a computer processor. The method described herein primarily relates to designing a cam element profile for an adjuster lever arm. The lever arm can be a master lever arm as described above. As described above, an adjuster typically includes a valve member. The cam element profile is configured to displace the valve member. According to... Figure 6 The method shown in the illustration begins at step 610: determining a first peak breathing gas flow rate at multiple different valve component displacements under a first breathing gas input pressure, thereby determining a first flow-displacement curve. The first flow-displacement curve can be viewed as the relationship between the breathing gas flow rate and the valve component displacement. The first flow-displacement curve can be determined through analysis and / or experience.

[0074] In some embodiments, the step of determining the first flow-displacement curve includes: firstly determining multiple peak breathing gas flow rates at each of a plurality of different valve member displacements at a first breathing gas input pressure. This data may be represented in a data point table. The data points may be interpolated to determine a trend line that can be used to determine the flow rate at any given valve member displacement at a given input breathing gas pressure. In some embodiments, the determined trend line is a linear trend line corresponding to a linear relationship between valve member displacement and peak breathing gas flow rate.

[0075] In step 612, a first minimum required peak flow rate is determined at the first breathing gas input pressure. The first minimum required peak flow rate represents the minimum peak flow rate required (e.g., acceptable) at a given breathing gas input pressure. The peak flow rate must be sufficient to allow a sufficient amount of breathing gas (e.g., free air volume) to flow through the valve member in order to provide an appropriate breathing gas pressure within the regulator when the valve is open.

[0076] Based on the first flow-displacement curve, in step 614, a first minimum valve displacement is determined to provide the first minimum required peak flow rate. Since the first flow-displacement curve represents the relationship between flow rate and valve component displacement at a given pressure, this curve can be used to determine the minimum valve component displacement that provides the minimum required peak flow rate.

[0077] In step 616, a first cam profile included in the cam element profile is determined, which causes the valve member to be displaced by at least a first minimum valve displacement over the entire first pivot arc of the lever arm. One or more portions of the first cam profile can displace the valve member to a position further than the first minimum valve displacement. For example, the end point of the first cam profile can displace the valve member further than the start point of the first cam profile.

[0078] This method can be repeated iteratively once or multiple times to optimize the cam element profile design (e.g., to bring the cam element profile design towards an ideal state) for a given set of design parameters. When the method is repeated, the cam element profile designed in the first iteration can be used to determine the first flow-displacement curve during the second iteration, and so on. In this way, the design of the cam element profile can be iteratively improved / optimized. Since the first flow-displacement curve is typically specific to each regulator, a regulator including a valve member and a lever arm with a “best guess” cam element profile can be used in the first iteration to provide a starting point for determining the first flow-displacement curve. After the first iteration of the method is completed, the lever arm of the regulator can be modified to include the cam element profile determined during the first iteration. A regulator with the modified lever arm can then be used in the second iteration, and so on.

[0079] In some embodiments, the method includes determining a second cam profile included in the cam element profile. To determine the second cam profile, the method may include the following steps: determining a second peak breathing gas flow rate at the second breathing gas input pressure under the plurality of different valve member displacements, thereby determining a second flow-displacement curve, which is determined in a manner similar to that of the first flow-displacement curve. The method may then proceed to the following step: determining a second minimum required peak flow rate at the second breathing gas input pressure. After determining the second minimum required peak flow rate, a second minimum valve displacement providing the second minimum required peak flow rate can be determined based on the second flow-displacement curve. A second cam profile can then be determined such that the valve member is displaced at least to the second minimum valve displacement over the entire second pivot arc of the lever arm.

[0080] In some embodiments, the first cam profile and the second cam profile may be arranged continuously along the cam element profile. The first cam profile may intersect the second cam profile at a transition point (e.g., a continuous transition point or a discontinuous transition point).

[0081] It should be understood that the method may further include: determining one or more additional cam profiles included in the cam element profile. Specifically, the method may include: determining a third cam profile included in the cam element profile. It should be understood that each determined cam profile corresponds to a valve member displacement. Therefore, in embodiments of this method that include determining a third cam profile or additional cam profiles, these cam profiles correspond to a third valve member displacement or an additional valve member displacement.

[0082] Method 600 may further include the following follow-up step: manufacturing a lever arm including the determined first cam profile. Method 600 may further include the following follow-up step: outputting data containing a 3D design model, such as a CAD model, manufacturing model, or manufacturing instructions. The manufacturing type may include additive manufacturing or subtractive manufacturing. The 3D design model may contain data indicating the determined cam element profile or indicating a lever arm including the determined cam element profile.

[0083] Although the implementation of the methods described herein is presented in a specific order, it should be understood that these steps can be performed in any suitable order, provided that the technical content of each step and any dependency of each step on other steps are taken into account.

[0084] Those skilled in the art will understand that although the invention has been described by way of example with reference to one or more exemplary embodiments, the invention is not limited to the disclosed examples, and alternative embodiments may be constructed without departing from the scope of the invention as defined by the appended claims.

Claims

1. A demand regulator (100) for a breathing device (10), the demand regulator comprising: The main lever arm (200) includes cam elements (220, 520, 540, 560) having a first profile (222, 522, 542, 562) and a second profile (224, 524, 544, 564), and the main lever arm (200) is pivotable; as well as A valve (300) is configured to regulate the flow rate of breathing gas through the demand regulator (100), the valve (300) including a valve member (320) that can be displaced to regulate the flow rate of breathing gas. The cam elements (220, 520, 540, 560) of the main lever arm (200) are configured to displace the valve member (320) during pivoting of the main lever arm (200); and in: The main arm (200) pivots through a first arc corresponding to the first profile (222, 522, 542, 562) of the cam elements (220, 520, 540, 560), causing the valve member (320) to shift at a first displacement rate; and The main arm (200) pivots through a second arc corresponding to the second profile (224, 524, 544, 564) of the cam element (220, 520, 540, 560) to displace the valve member (320) at a second displacement rate, which is different from the first displacement rate.

2. The demand regulator (100) according to claim 1, wherein, The second displacement rate is higher than the first displacement rate.

3. The demand regulator (100) according to claim 1, wherein: The pivot of the main arm (200) through the first arc corresponds to the pivot of the main arm (200) between the first rotation angle and the second rotation angle of the main arm (200); and The pivot of the main arm (200) through the second arc corresponds to the pivot of the main arm (200) between the third and fourth rotation angles.

4. The demand regulator (100) according to any one of the preceding claims, wherein, The main arm (200) is configured to pivot through the first arc when the breathing gas input to the demand regulator (100) is above the threshold pressure, and to pivot through the second arc when the breathing gas input to the demand regulator (100) is below the threshold pressure.

5. The demand regulator (100) according to claim 4, wherein, The threshold pressure is between 300 kPa and 600 kPa.

6. The demand regulator (100) according to any one of the preceding claims, wherein, The first contour (222, 522, 542, 562) and the second contour (224, 524, 544, 564) are convex.

7. The demand regulator (100) according to any one of the preceding claims, wherein, The first profile (222, 522, 542, 562) is a circular arch with a first radius, and the second profile (224, 524, 544, 564) is a circular arch with a second radius, wherein, optionally, the first radius is different from the second radius.

8. The demand regulator (100) according to any one of the preceding claims, wherein, The first contour (222, 522, 542, 562) and the second contour (224, 524, 544, 564) intersect at a transition point, which may be a continuous transition point or a discontinuous transition point.

9. The demand regulator (100) according to any one of the preceding claims further includes a secondary lever arm (400) disposed between the cam elements (220, 520, 540, 560) and the valve member (320), the secondary lever arm (400) being configured to transmit motion of the cam elements (220, 520, 540, 560) to the valve member (320).

10. The demand regulator (100) according to claim 9, wherein, The secondary lever arm (400) is an adjustable lever arm configured to adjustably change the proportion of motion transmitted from the cam elements (220, 520, 540, 560) to the valve member (320), wherein, optionally, the adjustable lever arm includes an adjusting screw (420).

11. The demand regulator (100) according to any one of the preceding claims further includes: The main body (104) defines the internal cavity (103); and A diaphragm (102) is disposed in the main body (104), a first side of the diaphragm (102) is in communication with the internal cavity (103), and a second side of the diaphragm is in communication with the surrounding environment; The main arm (200) is configured to be adjacent to the diaphragm (102), and a pressure drop in the internal cavity (103) will push the diaphragm (102) toward the internal cavity (103), thereby causing the main arm (200) to rotate.

12. A breathing device (10) comprising a demand regulator (100) according to any of the preceding claims.

13. A diaphragm actuation lever for a demand regulator (100), comprising: Cam elements (220, 520, 540, 560) for displacing the valve (300) of the demand regulator (100), the cam elements (220, 520, 540, 560) comprising a first cam profile and a second cam profile; and The diaphragm contact portion is configured to transmit the motion of the diaphragm (102) to the diaphragm actuation lever arm, thereby causing the diaphragm actuation lever arm to pivot; in: The lever arm pivots through a first arc corresponding to the first cam profile to displace the valve (300) at a first displacement rate; and The lever arm pivots through a second arc corresponding to the second cam profile to displace the valve (300) at a second displacement rate different from the first displacement rate.

14. A method for designing the profile of cam elements (220, 520, 540, 560) for a lever arm of a demand regulator (100), the demand regulator (100) including a valve member (320), the profile of the cam elements (220, 520, 540, 560) configured to displace the valve member (320), the method comprising the steps of: The first peak breathing gas flow rate under multiple different valve component displacements was determined at the first breathing gas input pressure, thereby determining the first flow-displacement curve; Determine the first minimum required peak flow rate at the first respiratory gas input pressure; Based on the first flow-displacement curve, determine the first minimum valve displacement to provide the first minimum required peak flow rate; and A first cam profile is defined in the profile of the cam elements (220, 520, 540, 560), the first cam profile causing the valve member (320) to be displaced at least to the first minimum valve displacement over the entire first pivot arc of the lever arm.

15. The method of claim 14, further comprising the step of: The second peak breathing gas flow rate was determined at multiple different valve component displacements under the second breathing gas input pressure, thereby determining the second flow-displacement curve; Determine the second minimum required peak flow rate at the second respiratory gas input pressure; Based on the second flow-displacement curve, determine the second minimum valve displacement to provide the second minimum required peak flow rate; and A second cam profile is defined in the profile of the cam elements (220, 520, 540, 560), the second cam profile causing the valve member (320) to be displaced at least to the second minimum valve displacement over the entire second pivot arc of the lever arm.

Images