METALLIC SUPPORT STRUCTURE IN THE DRIVE ARM/HEAD OF A MEDICAL FLUID PUMP

Abstract

A medical fluid pump, in particular a syringe pump, includes a housing and a drive head linearly movable toward the housing via a tubular or rod-shaped drive arm. The drive head has a drive head lower shell facing the housing and a drive head upper shell turned away from the housing. A metallic support structure in the form of a plate is accommodated in an interior space formed by the drive head lower shell and the drive head upper shell and is directly fixed to the drive head lower shell and to a free end portion of the tubular or rod-shaped drive arm.

Claims

1. A medical fluid pump comprising: a housing; a drive arm that is tubular or rod-shaped; a drive head linearly movable toward the housing via the drive arm; and a metallic support structure comprising a plate, the drive head having a drive head lower shell facing the housing and a drive head upper shell turned away from the housing, the metallic support structure being accommodated in an interior space formed by the drive head lower shell and the drive head upper shell, the metallic support structure being directly fixed to the drive head lower shell and to a free end portion of the drive arm.

2. The medical fluid pump according to claim 1, further comprising a U-shaped bracket extending in an axial direction of the drive arm, the U-shaped bracket being integrally formed on a side of the drive head lower shell facing the interior space so that the U-shaped bracket encompasses the drive arm and delimits an axial insertion depth of the drive arm in the drive head lower shell.

3. The medical fluid pump according to claim 1, wherein the metallic support structure comprises a first portion and a second portion formed separately from the first portion, each of the first portion and the second portion abutting on the drive arm.

4. The medical fluid pump according to claim 3, wherein the first portion and the second portion form a clamp which clamps the drive arm at the U-shaped bracket so that the drive arm is fixed in an axial direction and fixed against rotation.

5. The medical fluid pump according to claim 4, wherein the clamp has an inner contour reproducing the U-shaped bracket which permits an axial and rotational fine alignment at the U-shaped bracket.

6. The medical fluid pump according to claim 3, wherein the first portion is indirectly connected to the drive head lower shell via a screwed connection.

7. The medical fluid pump according to claim 3, wherein the first portion includes a recess for passing through cables.

8. The medical fluid pump according to claim 3, wherein the first portion and the second portion are detachable from each other.

9. The medical fluid pump according to claim 1, wherein the metallic support structure engages, via projections, in bores of the drive arm and fixes the drive head lower shell relative to the drive arm in an axial direction and fixes the drive head lower shell against rotation.

10. The medical fluid pump according to claim 1, wherein the drive head upper shell closes and fluid-tightly seals the interior space without aligning components in the drive head lower shell.

11. The medical fluid pump according to claim 1, wherein the medical fluid pump is a syringe pump.

Description

BRIEF DESCRIPTION OF THE DRAWING FIGURES

[0020] The disclosure shall be illustrated in detail in the following by means of Figures using a preferred embodiment.

[0021] FIG. 1 is a perspective view of a syringe pump according to the invention.

[0022] FIG. 2 is a perspective view of a drive head comprising swivel arms and a drive arm.

[0023] FIG. 3 is a perspective view of the inner face of the drive head lower shell without an installed base plate.

[0024] FIG. 4 is an exploded view of the drive head lower shell as well as the components of base plate, board and board end plate to be inserted.

[0025] FIG. 5 is a perspective view of the drive head lower shell comprising the inserted components of base plate, board and board end plate as well as an exploded view of the support structure consisting of the first and second portions.

[0026] FIG. 6 is a perspective view with the inserted base plate, board and board end plate and the mounted support structure.

[0027] FIG. 7 shows an exploded view of the drive head lower shell with installed components and support structure as well as the drive head upper shell.

[0028] The Figures are schematic and serve only for the comprehension of the disclosure. Like elements are provided with like reference symbols.

DETAILED DESCRIPTION

[0029] FIG. 1 illustrates a fluid pump according to the disclosure, in particular a syringe pump 1 comprising a pump housing 2 and a display 3 on the front side thereof. Laterally from the display 3 on a sidewall of the housing 2, a drive head 4 disposed substantially perpendicularly to the sidewall of the housing 2 is provided (outside the housing 2), which drive head 4 can be retracted and extended via a retaining/drive arm 5 (FIG. 2) substantially perpendicularly to the sidewall of the housing 2.

[0030] For operating the syringe pump 1, the display 3 can be unfolded and a syringe (not shown) with a filled syringe barrel can be inserted into a dedicated free space in the syringe pump 1. The free end of an extracted syringe plunger is further fixed to the drive head 4 which has been extended before via the drive arm 5 away from the sidewall of the housing 2, preferably with two swiveling angled arms 6 (FIG. 2) as a part of the drive head 4. In order to empty the syringe content in a controlled manner, the drive head 4 serving as a stop for the syringe plunger here is displaced toward the sidewall of the housing 2 preferably via a spindle drive inside the housing not shown in more detail.

[0031] As is evident from FIG. 1, the drive head 4 consists of a drive head lower shell 7 facing the housing 2 and preferably made of plastic and a drive head upper shell 8 turned away from the housing 2 and equally preferably made of plastic.

[0032] FIG. 3 illustrates the inner face of the drive head lower shell 7. As is visible, a free end portion 9 of the drive arm 5 is accommodated in a U-shaped bracket 10 serving as a stop. Further, a clamp sleeve 40 which is also passed through through-holes located at the free end portion 9 of the drive arm 5 extends transversely through the legs 11 of the U-shaped bracket 10. Using the clamp sleeve 40, the drive arm 5 is already preadjusted relative to the drive head and secured in the axial direction as well as against rotation relative to the drive head.

[0033] In FIG. 4, a base plate with electronic components 12, hereinafter merely referred to as base plate 12, inserted in the drive head lower shell 7 is shown. It is emphasized that the base plate 12 is merely inserted or attached but not screwed with the drive head lower shell 7. The base plate 12 includes three circular recesses 13 and two guide strips 14 substantially perpendicularly projecting from the base plate 12 by means of which the base plate 12 is aligned at dedicated contours of the drive head lower shell 7. Inserting the base plate 12 without screwing offers the advantage that no screwing points must be provided which might produce different stress zones on the surface of the base plate 12 and which might transfer locally concentrated shock pulses to the base plate 12 which may result in damage of the electronic components fastened on the base plate 12. At the same time, the mounting position of the base plate 12 is safeguarded by the recesses 13 and guide strips 14 which align the base plate 12 at the contours of the drive head lower shell.

[0034] Further, three substantially perpendicularly projecting cylinder pins 15 which at their free ends form a circular shoulder 16 with a cylinder pin tip 17 situated centrally therein are arranged on the base plate 12. A board 18 including three corresponding circular recesses 19 is placed, in turn, on the three shoulders 16, the recesses 19 indirectly encompassing the cylinder pin tips 17. Further, a board end plate 20 is placed onto the board 18. The board end plate 20 includes three sleeve-type extensions 21 on its side facing the board 18. The sleeve-type extensions 21 engage in the circular recesses 19 of the board 18, equally rest on the circular shoulders 16 of the cylinder pins 15 and directly enclose the cylinder pin tips 17. As the sleeve-type extensions 21 engage in the recesses 19 of the board 18 and at the same time directly encompass the cylinder pin tips 17, the board end plate 20 rests stably on the board 18 without getting out of place relative to the latter.

[0035] FIG. 5 illustrates the drive head lower shell 7 comprising the already inserted base plate 12, the board 18 and the board end plate 20. Moreover, a metallic support structure 22 is visible in an exploded view and consists of a first portion 23 and a second portion 24 both of which are provided to encompass the free end portion 9 of the drive arm 5 and the U-shaped bracket 10.

[0036] Moreover, on the end face of the first portion 23 of the support structure 22 a first cylindrical projection 25 and a second cylindrical projection 26 of a different circle diameter can be seen which are adapted to engage in two bores 27, visible in FIG. 3, and to secure the drive arm 5 relative to the drive head in the axial direction as well as against rotation in the installed state of the support structure 22 in the drive head lower shell 7.

[0037] The first portion 23 of the support structure 22 also includes, on its end face, a strip-like extension 28 with two differently sized recesses which are adapted to enable two differently sized tooth-like projections 29 at the second portion 24 of the support structure 22 to engage in the recesses of the strip-like extension 28. The side of the second portion 24 of the support structure 22 opposite to the tooth-like projections 29 in turn includes two through-bores 30 via which, using two screws 31, the second portion 24 of the support structure 22 can be screwed with the first portion 23 of the support structure 22 on the end face of which two threaded holes 32 are provided.

[0038] FIG. 6 shows the support structure 22 in the mounted state in the drive head lower shell 7. As is evident, the first portion 23 and the second portion 24 of the support structure 22 jointly form a clamp 22 which clamps the free end portion 9 of the drive arm 5 enclosed therein so that the drive head is secured relative to the drive arm in the axial direction as well as against rotation. It is emphasized in this context that the inner contours of the first portion 23 and the second portion 24 situated toward the free end portion 9 of the drive arm 5 reproduce the U-shaped bracket 10, thereby allowing for axial and rotational fine alignment at the U-shaped bracket 10.

[0039] As can also be seen from FIG. 6, the first portion 23 of the support structure 22 is screwed with the board end plate 20 via a screwed connection 33, resulting in the support structure 22 being indirectly connected to the drive head lower shell 7 by resting on the board end plate 20. At the same time, in the mounted state the first portion 23 and the second portion 24 of the support structure 22 directly rest, with the respective so-to-speak lower clamp side, on a shoulder of a sleeve-type portion 34 of the drive head lower shell 7, which is visible in FIG. 3.

[0040] As is evident from FIG. 6, the base plate 12, the board 18 and the board end plate 20 are held together sandwich-like via defined pressing forces from two sides, namely on the lower side by the drive head lower shell 7 and on the upper side by the first portion 23 of the support structure 22. The defined pressing forces are mainly resulting from the predetermined spaces as a result of the direct bearing faces between the support structure 22 or, resp., clamp 22 and the sleeve-type portion 34 of the drive head lower shell 7 as well as via the stacking height between the base plate 12 and the board end plate 20 which is significantly defined by the length of the cylinder pins 15.

[0041] The afore-mentioned type of assembly or the clamp-like arrangement of the drive head lower shell 7 and the support structure 22 with the interposed sensitive components which are situated above all on the base plate 12 and the board 18, offers the advantage that screwed connections can be almost completely dispensed with in shock-sensitive zones and that the pressing forces required for the cohesion of the base plate 12, the board 18 and the board end plate 20 can be distributed extensively and evenly. The support structure 22 further adopts the function of a partition from the drive head upper shell 8 and additionally protects the components situated in the drive head lower shell against impacts.

[0042] It is also visible in FIG. 6 that the U-shaped bracket 10 has on its end face a U-shaped recess 35 which serves for guiding a ribbon cable 36 which is guided through the drive arm 5. In the first portion 23 of the support structure 22, a connector recess 37 is provided which enables the ribbon cable 36 guided out of the drive arm 5 to be guided through the support structure 22 and to be connected to the board 18 underneath.

[0043] FIG. 7 illustrates an exploded view of the drive head lower shell 7 with components installed there and the support structure 22 as well as the drive head upper shell 8. The drive head upper shell 8 is screwed, via through-bores 38, with screw bosses 39 in the drive head lower shell 7 so that the drive head upper shell 8 closes and seals the drive head 4 without the drive head upper shell 8 or the screwed connections having an influence on the alignment of the base plate 12 and the board 18. Possible flows of forces caused by impacts onto the drive head upper shell 8 are thus not transferred directly to the base plate 12 and the board 18. The base plate 12 and the board 18 are quasi force-decoupled from direct force impacts of the drive head upper shell 8 and absorb them only indirectly via the bearing face in the drive head lower shell 7.