Hose pump, in particular an insulin pump
First Claim
1. In a hose pump of the type comprising an elastic hose for local compression between a hose supporting face and at least one pressure roller for rotation at a constant speed of rotation around an axis, of the pressure roller whereby to pumpingly flow liquid in the hose to an outlet end of the hose, the supporting face being formed with a track for receiving the hose, the track having a varying depth for determining the degree of the local hose compression, the improvement in that the track comprises at least one section with an increasing engagement angle and at least one section with a decreasing engagement angle, the engagement angle being the angle between the axis and the track and, thereby, the hose therein at the point of the local compression between the pressure roller and the hose, the sections of the track being so positioned and their engagement angles so increased and decreased as to comprise compensation means for increasing the flow of the liquid in the hose by an amount compensating for decreased flow caused by opening of the outlet end of the hose.
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Accused Products
Abstract
A hose pump (1) consisting of a hose (2), at least one, preferably two pressure rollers (3,4), a support plate (9) and a drive source (26). The hose (2) is paced in a hose receiving track (6) in the support plate (9). The rollers (3,4) are rotatably journalled on a common rotary shaft (10), whose center (11) is firmly connected with a drive shaft (12), which is perpendicular to the support face (5) of the support plate (9) engaging the rollers (3,4). The rollers (3,4) act on the hose (2) in the flow direction of the pump (1) and alternately determine, in specific angle ranges, the liquid volume flow discharged. The succeeding roller (4) cooperates with the hose (2) in such a manner that the hose is completely closed when the forwardly disposed roller (3), as seen in the flow direction, initiates its disengaging movement away from the hose (2). During the following opening movement of the forwardly disposed roller (3) from having closed the hose (2) completely to letting it be completely open, the succeeding roller (4) cooperates with the hose (2) so that hose, in addition to discharging a volume flow corresponding to the normal volume flow of the pump (1), also discharges an additional volume flow to compensate for the loss caused by the opening movement of the forwardly disposed roller (3). Then, the volume flow discharged by the pump (1) is constant per unit of time. Further, reverse suction in the outlet end of the hose is obviated.
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Citations
14 Claims
- 1. In a hose pump of the type comprising an elastic hose for local compression between a hose supporting face and at least one pressure roller for rotation at a constant speed of rotation around an axis, of the pressure roller whereby to pumpingly flow liquid in the hose to an outlet end of the hose, the supporting face being formed with a track for receiving the hose, the track having a varying depth for determining the degree of the local hose compression, the improvement in that the track comprises at least one section with an increasing engagement angle and at least one section with a decreasing engagement angle, the engagement angle being the angle between the axis and the track and, thereby, the hose therein at the point of the local compression between the pressure roller and the hose, the sections of the track being so positioned and their engagement angles so increased and decreased as to comprise compensation means for increasing the flow of the liquid in the hose by an amount compensating for decreased flow caused by opening of the outlet end of the hose.
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3. A hose pump according to claim, wherein, in a first path section (B-C), the hose track (6), as seen in the flow direction (S) from the point (19) where the hose (2) is just closed, constitutes a circular arc segment (20) with an evenly increasing radius measured from the axis (18) of the drive shaft and with an evenly decreasing track depth, and that, in a second path section (E-F) which is traversed by the front roller (3) as the rear roller (4) traverses the first path section (B-C), the hose track (6) has the same shape as in the first path section (B-C), but with a constantly increasing track depth, and that, in a third path section (C-E) disposed between the said first and the said second path sections, the hose track (6), as seen in the flow direction (S), is shaped as at least two successive (21, 22 and 22'"'"') segments of Archimedean spirals with an evenly increasing radius and an evenly decreasing radius, respectively, followed by a third circular arc segment with a constant radius, and that, in a fourth path section (F-G) disposed after a path section (E-F), the hose track (6), as seen in the flow direction (S), is shaped as a fourth circular arc segment (24) with a constant radius and with a continuously increasing track depth, the arc angle of said fourth path section (F-G) corresponding to the arc angle of the path section (C-D) within which the track (6) has two or more successive spiral-shaped courses (21, 22 and 22'"'"').
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6. A hose pump of the type comprising an elastic hose which may be compressed locally on its length between an inlet (13) and an outlet (14) section thereof between a hose supporting face (5) and at least one pressure roller orbiting around an axis whilst rotating around its own axis, said support face (5) being formed with a track (6) adapted to receive the hose and whose varying depth determines the degree of hose compression, said track being so arranged that at least two portions of the hose are affected simultaneously by the same or respective rollers, characterized in that said track comprises at least one section with an increasing engagement angle and at least one section with a decreasing engagement angle, said engagement angle being defined by the angle (α
- ) between the axis (H-I) of rotation of the pressure roller and the tangent to the hose at the point of contact between the pressure roller and the hose, said sections being so positioned that the increased flow caused by the varying engagement angles compensates the decreased flow caused by the opening of the hose at the outlet section of the hose.
- View Dependent Claims (7, 8, 9, 10, 11, 12, 13, 14)
Specification