US3499601A

US3499601A - Pump for medical purposes

Info

Publication number: US3499601A
Application number: US705746A
Authority: US
Inventors: Asmund S Laerdal
Original assignee: Individual
Current assignee: Individual
Priority date: 1967-02-18
Filing date: 1968-02-15
Publication date: 1970-03-10
Anticipated expiration: 1987-03-10
Also published as: NO116099B; DE1616201B2; DE1616201C3; GB1200841A; NL6802132A; FR1555102A; DE1616201A1

Description

March 10, 1910 SQ LA ERDAL 3, 9

I PUMP on mnnxcn, PURPOSES 2 Sheets-Sheet 1 FiledFeb. 15, 1968 il it'l llllll. llllllllllllllLnnnclJ FIG.1

, mvemron: Asmund-s. Laerclu United States Patent Office Patented Mar. 10, 1970 3,499,601 PUMP FOR MEDICAL PURPOSES Asmund S. Laerdal, Stavanger, Norway Filed Feb. 15, 1968, Ser. No. 705,746 Claims priority, application Norway, Feb. 18, 1967, 166,906/ 67 Int. Cl. F04!) 37/10, 21/04 US. Cl. 230-492 7 Claims ABSTRACT OF THE DISCLOSURE The invention relates to a double-acting, combined vacuum and pressure pump for medical purposes. Such pumps may be used for the removal of secretion and for use in combination with asthma appliances.

Known pumps of this type have the disadvantage that relatively small secretion particles which unavoidably penetrate into the pump chamber may give rise to difliculties. A further disadvantage consists in that special tools are necessary for their assembly and disassembly and that this work can only be done by mechanical experts. Furthermore, it may frequently be necessary to clean the pump. This cleaning must as a rule be carried out by people having little mechanical knowledge, such as nurses.

According to the present invention, there is provided a double acting combined vacuum and compression pump, for medical purposes, such pump comprising a pump cylinder having two pistons axially slidable therein, such pistons being spaced apart by a rigid connecting member to form a free space between said pistons, an external conduit connected to each of the cylinder end walls, a crank mounted for rotation in the cylinder side wall about an axis substantially perpendicular to the cylinder axis, said crank engaging said connecting member to reciprocate said connecting member and pistons upon rotation of said crank, the side wall of the cylinder having an aperture therethrough in communication with said free space, said pistons each having an orifice providing communication between the cylinder end chambers and the free space, a first pair of valves associated with the cylinder end walls, selectively to disconnect said external conduit from said cylinder end chambers, and a second pair of valves associated with said piston orifices, whereby reciprocation of said pistons causes said cylinder end chambers to act as suction chambers, and said free space to act as a compression chamber.

The pump according to the invention, which is suitable for use both for the removal of secretion and also in combination with asthma appliances, is, due to the provision of the valves, substantially insensitive to the penetration of secretion particles into the pump interior. The pump continues to operate even if a relatively large quantity of secretion has penetrated into the pump interior. The secretion which has entered therein is able to penetrate through the valves into the free space and to flow from there, via the aperture in the cylinder wall, without the pump coming to a standstill. Simultaneously, the simple association of the pump and pump drive crank ensures that the unit can, for cleaning purposes, be assembled and reassembled without difficulty.

According to a preferred embodiment, the two pistons are connected together by a wide web extending between said pistons and formed with a transverse slot engaged by said crank. Advantageously, a seating flange extends outwardly from the central portion of said cylinder side wall, and an electric motor, having an annular rim thereon, seats in an annular groove on said seating flange, the drive shaft of said motor being connected to said crank.

In order that the invention may more readily be understood, the following description is given, merely by way of example, reference being made to the accompanying drawings, in which:

FIGURE 1 is a longitudinal section through one embodiment of the pump according to the invention and through a secretion container connected thereto, and

FIGURE 2 shows a cross-section through the pump cylinder of FIGURE 1, half-way up the height thereof.

The pump has a single cylinder 1 which is manufactured from transparent plastics material. Enclosed in the cylinder are two plungers or pistons 2 connected together co-axially, by a broad plate-like web 3 centrally recessed at both ends and forming between the pistons a free space 2'. In the web 3 is a slot 4 which extends transversely of the cylinder axis and in which a crank shaft arm 5 engages. The crank shaft arm 5 has a surrounding self-lubricating sleeve 20 and is directly conne'cted with the driving shaft of an electric motor 15 arranged on the cylinder wall.

The motor may receive its current from electrical batteries or directly from the mains, or from the mains via a rectifier.

Arranged in the plungers 2 and in the covers of the cylinder 1 are valves 11 designed as large, soft clack valves. The valves 11 of the plungers are situated in the recessed portions of the web. The clack valves readily permit the passage of secretion particles, without the pump being thereby put out of operation. During the operation of the plungers, the free space 2' serves as a compression chamber whereas a vacuum forms in the cylinder end chambers 17. In the illustrated embodiment, the vacuum chambers 17 are connected by

flexible tubes

8 and 9 with a separate secretion collector container 7, which may be connected by means of a pipe 10, with the patient. .Alternatively, the vacuum chambers 17 may be connected, by means of the

flexible tubes

8 and 9 directly With the patient, the container 7. then being omitted.

Formed in the zone of the free space 2' in the lateral wall of the cylinder 1 is an aperture 6, which serves for the discharge of any secretion which has penetrated into the cylinder. The aperture 6 may, if desired, be provided with a flexible tube, for the purpose of blowing-in air when treating an asthma patient.

The pump operates with only a slight degree of resistance and is self-lubricating. This is extremely important for medical pumps since, when the pump according to the invention is used in combination with asthma appliances, it is necessary to avoid contamination of the compressed air by oil vapours, and it is also necessary to avoid excessive heating of the air. The large-dimensioned clack valves 11 are preferably manufactured fromsoft silicone rubber, so that their functioning is not detrimentally influenced by secretion particles, and a good sealing effect is always achieved. Filters 12 are fitted in both ends of the cylinder. v

The central zone of the side wall of the cylinder 1 is provided with a seating flange 16, having an annular groove therein, in which a flange on the base 13 of the motor 15 seats. The flange on the base 13 is held in place by countersunk head screw bolts 14, which ensure accurate relative positioning of the motor and the cylinder. A packing is additionally provided on the inner side of the motor base 13. By means of the motor base 13 and the packing, the cylinder chamber is sealed with respect to the motor 15.

Since the cylinder housing 1 and the plungers 2 are manufactured from a transparent plastics material, effective monitoring of the pump is guaranteed, so that the necessity for cleaning is observed in good time. The transparency furthermore facilitates the assembly of the crank shaft arm 5.

The pump is mounted, preferably upright, in a suitcase. In use, however, it may also be horizontal, so that the pump cylinder adopts a horizontal position. The aperture 6 for discharge of the secretion for the central compression chamber is therefore formed in the cylinder Walls, on the downwardly located side, so that the secretion is able, during operation of the pump in the horizontal postion, to run unhindered out of the compression chamher.

What is claimed is:

1. A double acting combined vacuum and compression pump, for medical purposes, said pump comprising, in

combination:

(a) a pump cylinder;

(1)) at least one side wall and two end walls to said cylinder, at least a part of said side wall being transparent;

(c) two spaced coaxial pistons axially slidable in said cylinder;

(d) a web rigidly connecting said pistons to define a free space therebetween, said web being centrally recessed at both ends and provided with a slot extending transversely of the cylinder axis;

(e) crank means mounted in said cylinder side wall for rotation about an axis perpendicular to the cylinder axis, said crank means engaging in said slot of said web, effective to reciprocate said web and pistons upon rotation of said crank means;

(f) an external conduit connected to each of said cylinder end walls;

(g) an aperture through said cylinder side wall communicating with said free space;

(h) an orifice situated centrally in each piston providing communication between cylinder interior adjacent said end walls and said free space;

(i) a first pair of centrally positioned, large dimension, soft clack valves associated with said cylinder end walls selectively to disconnect said conduit; and

(j) a second pair of centrally positioned, large dimension, soft clack valves associated with said piston orifices, whereby reciprocation of said pistons causes said cylinder interior adjacent said end walls to act as suction chambers and said free space to act as a compression chamber.

2. A pump as defined in claim 1, and further comprising a separate container connected to said external conduit, and separate conduit means for connecting the container to a source of secretions, whereby secretions are collected in the container during pump operation.

3. A pump as defined in claim 1, and further comprising a seating flange extending outwardly from said cylinder side wall, an annular groove in said seating flange, an electric motor, an annular rim on said motor seating in said annular groove, countersunk head screw bolts connecting said annular rim to said seating flange, and a drive shaft to said motor driving said crank means, said countersunk head screw bolts ensuring accurate relative positioning of said motor and said cylinder.

4. A pump as defined in claim 1, wherein said cylinder side Walls are manufactured from a transparent plastics material.

5. A pump as defined in claim 4, wherein said pistons are manufactured from a transparent plastics material.

6. A pump as defined in claim 1, in which said pump is self-lubricating.

7. A pump as defined in claim 6, in which said crank means comprises a crank arm having a surrounding selflubricating sleeve.

References Cited UNITED STATES PATENTS Re. 24,932 1/1961 Davey.

84,754 12/1868 Palmer 103-186 275,680 4/1883 Marchand 103-186 1,952,640 3/1934 Ventress et a1. 103-186 2,515,956 7/1950 Greenberg. 2,295,592 9/1942 McConnohie 103-186 2,611,323 9/1952 Digney. 2,704,234 3/1955 Love et a1 308-237 3,120,338 2/1964 Rhodes 230-58 3,410,477 11/1968 Hartley 230- 95,943 10/ 1869 Sluthoin 103-186 FOREIGN PATENTS 417,127 1910 France.

HENRY F. RADUAZO, Primary Examiner