Hand Vacuum Pump

Abstract

A small and compact vacuum pump which serves as a portable vacuum source. The pump includes a cylinder coupled with one handle and a piston therein coupled with another handle, along with a wafer valve assembly for allowing a vacuum to be drawn at an outlet of the pump. An indicator may be coupled with the outlet and may include a member for releasing the vacuum. The pump and indicator assembly are particularly useful with vacuum extractors used by doctors during childbirth, or any other use that requires a simple, lightweight, compact and portable vacuum source.

Description

The present invention relates to pumps, and more particularly to a relatively simple, lightweight, compact and portable pump and indicator therefor.

Various types of vacuum pumps have been devised, but many suffer from one or more disadvantages. Among these are the complexity of the pump, the costs of manufacture, bulkiness, and so forth. Additionally, increasing use is being made of vacuum extractors during childbirth, such as the extractor described in U.S. Pat. No. 3,202,152. However, many hospitals do not have a readily available vacuum supply for use with such extractors.

Accordingly, it is a principal object of this invention to provide an improved portable vacuum source.

An additional object of this invention is to provide a relatively compact vacuum pump which can be manufactured at low cost. A further object of this invention is to provide a novel hand-held vacuum pump and indicator therefor.

Another object of this invention is to provide a new indicator.

These and other objects and features of the present invention will become better understood through a consideration of the following description taken in conjunction with the drawing in which:

FIG. 1 is a view, partially in section, of a vacuum pump and indicator constructed in accordance with the present invention;

FIG. 2 is a sketch of a typical vacuum extractor;

FIG. 3 is a fragmentary view of a portion of the piston of the pump of FIG. 1;

FIG. 4 is a cross-sectional view of a portion of the pump taken along a line 4--4 of FIG. 1;

FIG. 5 is a cross-sectional view taken along a line 5--5 of FIG. 1;

FIG. 6 is a partial perspective view of a portion of the cylinder and cover therefor of the pump; and

FIG. 7 is a view of an alternative indicator arrangement.

Turning now to the drawing, a vacuum pump, generally denoted by the numeral 10, is illustrated in FIG. 1 along with a vacuum indicator 11. A flexible plastic tube 12 may be coupled from the indicator 11 to a vacuum extractor 13 shown in FIG. 2, such as that described in the aforementioned patent. Such extractors are known and are used instead of forceps by doctors during childbirth. The bell end 14 of the extractor is positioned on the head of the baby, and a vacuum is drawn by the pump 10 to the desired level as indicated by the indicator 11, and then the extractor 13 is used in withdrawing the baby during delivery.

Considering now the particular construction of the pump 10 and indicator 11, the pump includes a lower handle member 15 which is formed with depressions for the fingers of the hand of the operator and is affixed to a cylinder 16. An upper handle member 17 is pivoted at 18 on a support 19 upstanding from the handle 15, and an end of the handle member 17 is coupled at 20 to a piston rod 21. The piston rod extends into the cylinder 16 and includes a head 22 as best seen in FIG. 3 which supports a flexible piston 23.

The pivot member 18 may be cylindrical and formed as a part of the support 19. The member 18 is perpendicular to the support 19 and snaps into a circular opening in the handle 17. In this manner, the handle 17 can be released from the support 19 thereby allowing the piston rod and piston to be removed from the cylinder 16 by rotating and unlocking a cylinder cap 25 (note FIG. 6).

The piston 23 normally is biased downwardly to the bottom 26 of the cylinder 16 by a spring 27. The piston rod 21 may be flat and have a pair of reinforcing ribs on the opposite sides thereof, only rib 28 being seen in the drawing. The piston head 22 has a circular face 29 and is bevelled outwardly at 30 to form a lower flange for receiving and retaining the piston 23. The piston 23 is retained in position by a snap ring 31 which in turn is maintained in position by protrusions 32 on the piston rod 21. The piston 23 preferably has the configuration illustrated in FIG. 3, with the bottom annular face 33 thereof flush or slightly below the lower face 34 of the head 22 so that the piston extends all the way to the bottom 26 of the cylinder 16 thereby providing a very small void which must be exhausted to enable the pump to pull a good vacuum. The piston 23 may be made of any suitable flexible material, such as flexible polyurethane. By having the beveled surface on the piston head 22, the upper edge 35 of the piston is forced outwardly and forms a good seal with the cylinder 16 as the piston is pulled upwardly by the handle 17.

An exhaust port 36 is formed as an integral part of the cylinder 16 and handle 15, and includes a wafer valve 37 which is biased by a spring 38 to normally close an exhaust outlet 39. The spring is retained in position by a cap 40 which includes an opening 41 to the exterior of the pump. The outlet 39 is provided at the bottom of the cylinder 16 to allow the best vacuum to be pulled.

An adapter 42 is secured to the bottom wall 26 of the cylinder 16 which has several openings 43 therethrough. The adapted 42 serves to house a wafer valve 44 which is normally biased to close an inlet 45 by means of a spring 46 mounted on a projection 47 extending downwardly from the bottom wall 26 of the cylinder 16. The lower end of the adapter 42 includes a bore 48 for receiving the indicator 11, or other device, or tubing which is used with the pump 10.

The indicator 11 includes a body 50 having an outlet 51 coupled within the bore 48 of the adapter 42, an inlet 52 to which the tubing 12 is coupled, an exhaust 53, and a gauge port 54. A cylindrical indicator housing is coupled to the port 54. An indicator rod 57 is positioned in the housing and includes an outer end 58 which has indicia thereon, an inner end 59, with a piston 60 therebetween. An O-ring 61 is mounted on the piston, and a spring 62 normally biases the indicator rod 57 to the position shown in FIG. 1. A cap 63 is provided on the end of the indicator housing 56.

A wafer valve 65 is mounted at the exhaust port 53 at the other end of the indicator 11, and is normally biased to close the port 53 by a spring 66. The spring 66 is retained by a cap 67 having an exhaust opening 68 therein. The left end 69 of the indicator rod 57 is of reduced diameter so that the rod may be depressed into the housing 56 (to the left as viewed in FIG. 1) and body 50 to depress the wafer valve 65 and thereby vent the exhaust port 53 to the atmosphere through the exhaust opening 68. As will be apparent, this allows the vacuum to be readily released as desired. Ribs 70 within the left end of the housing serve as a bearing for the end 69 of the rod 57.

The pump 10 is operated by working the handle 17 up and down with respect to the handle 15. Each time the handle 17 is depressed (rotated counterclockwise as seen in FIG. 1), the piston rod 21 raises the piston 23. This causes the pressure to be reduced in the lower part of the cylinder 16 thereby causing the wafer valve 44 to raise against the bias of the spring 46 and provide a reduced pressure through the tube 12. As the piston 23 moves to the bottom of the cylinder 16 through the force of the spring 27, the wafer valve 44 closes, and the wafer valve 36 opens thereby exhausting the cylinder 16 through the exhaust outlet 41. It will be noted that the piston 23 moves all the way to the bottom 26 of the cylinder 16 and relatively close to the wafer valve 44 thereby minimizing the void space below the piston which must be exhausted each time the piston is raised.

As a vacuum is drawn in the tube 12, the piston 60 of the indicator rod 57 is drawn against the force of the spring 62. The indicator rod 57 thus moves to the left as viewed in FIG. 1 to provide an indication of the degree of vacuum drawn by the pump. Suitable markings may be hot stamped on the end 58 of the rod 57. When it is desired to release the vacuum, the rod 57 is merely completely depressed against the force of the spring 62 thereby causing the end 69 thereof to move the wafer valve 65 away from the port 53 thereby exhausting the tube 12 to the atmosphere through the opening 68.

An alternative indicator arrangement is illustrated in FIG. 7 and includes a body 75 and conventional dial-guage vacuum indicator 76. The body 75 has an outlet port coupled with the bore 48 of the adapter 42, an inlet 78 coupled with the tubing 12, an exhaust port 79, and a gauge port 80 to which the gauge 76 is coupled. A wafer valve 81 is normally biased by a spring 82 to maintain the exhaust port 79 closed, but may be opened by pulling release rod 83. The gauge 76 is a conventional vacuum gauge and includes a pointer 84 for indicating the vacuum pulled by the pump.

The body of the pump, that is the handle 15, cylinder 16, handle 17 and support 19 may be molded of high-impact styrene. The other rigid components of the pump, such as the piston rod 21, cap 25, cap 40, adapter 42, body 50, housing 56, indicator rod 57, and caps 63 and 67 may be formed of the same material. The wafer valves may be formed of rubber or flexible polyvinylchloride, and the springs may be metal. The adapter 42 may have a threaded inlet if desired for receiving the indicator body 50, or for receiving other types of indicators or other devices. Additionally, although a relatively simple coupling has been shown between the pivot member 18 and support 19 for the handle 17 so as to allow ready release of the piston and piston rod by unsnapping the handle and rotating the cap 25, other arrangements may be provided, such as a detachable coupling between the handle 17 and upper end of the piston rod 21.

It will be apparent that a relatively simple and compact pump which serves as a portable vacuum source is provided according to the teachings of the present invention. A typical pump according to this invention may have a cylinder bore of approximately 1 inch and a length of approximately 2 inches, with the length of the handles approximately 61/2inches. A pump of this general size constructed as described above can easily pull a vacuum of 26 inches.

It will be apparent that such a portable vacuum supply is particularly useful in hospitals because such devices can be manufactured relatively inexpensively and be disposable. Furthermore, pumps according to the present invention are useful in various applications, such as withdrawing oils or other fluids from automotive components, as for withdrawing oil from crankcases or transmission fluid from transmissions.

The present embodiments of this invention are to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims therefore are intended to be embraced therein.

Claims

What is claimed is:

1. A compact vacuum pump comprising

a cylinder and piston assembly, the cylinder of the assembly including an elongated body having a cover on a first end thereof, and inlet opening through said cover and an exhaust outlet through said cylinder at first end thereof, and the piston of the assembly comprising a piston head having resilient member coupled therewith and a piston rod, the interior of said body at said first end of said cylinder and said piston head being configured to allow said piston head to move completely to said cover at said first end of said cylinder for creating a minimum void between said piston head and interior of said cylinder at said first end for enabling a good vacuum to be drawn through said inlet by reciprocation of said piston in said cylinder,

first valve means coupled with said inlet opening of said cylinder, and second valve means coupled with said exhaust outlet of said cylinder,

biasing means coupled with said piston for normally biasing said piston toward said first end of said cylinder, and

adapter means coupled with said cylinder and housing said first valve means for enabling a vacuum to be drawn on an external device, said adapter means including manually operable valve means for releasing the vacuum drawn on an external device.

2. A pump as in claim 1 including

a first handle coupled with said cylinder, a second handle coupled with said piston rod, and releasable pivot means forming a fulcrum and interconnecting said handles for enabling reciprocation of said piston in said cylinder upon operation of said handles, and

cap means lockable with the second end of said cylinder, said piston rod extending through said cap means, and said releasable pivot means enabling said handles to be disengaged for unlocking of said cap means and removal of said piston from said cylinder.

3. A pump device as in claim 1 wherein

said exhaust outlet includes an aperture extending through the body of said cylinder at said first end thereof and adjacent said cover, and said biasing means normally biases said piston to close said exhaust outlet.

4. A compact vacuum pump comprising

a piston and cylinder assembly including a cylinder with a piston disposed therein and means for reciprocating said piston within said cylinder, said cylinder including a body having a cover at one end thereof, said cylinder having an exhaust opening and said cover having an inlet,

an adapter coupled with said cylinder, said adapter having a first end coupled to said cylinder at said inlet and a second end adapted to be coupled to an external device and a passageway communicating between said ends, a valve mounted in said passageway near said first end of said adapter for controlling the flow of fluid from an external device through said adapter and said cylinder to said exhaust opening, and

said adapter including an exhaust port between said second end of said adapter and said valve and having valve means for normally closing said exhaust port, and manually operable means coupled with said valve means for enabling the vacuum pulled on an external device to be readily released.

5. A pump as in claim 4 wherein

said adapter has indicator means coupled therewith and communicating with said passageway for indicating the vacuum pulled by said pump, said indicator means having a moveable member forming said manually operable means.

6. A compact pump comprising

a cylinder having a piston therein and a piston rod coupled with said piston,

a first handle formed integral with said cylinder, a second handle coupled with said piston rod, and means releasably and pivotally coupling said handles together to provide a fulcrum to enable reciprocation of said piston in said cylinder upon operation of said handles and for enabling one handle to be readily released from the other,

said cylinder comprising a body having a cover on the first end thereof with a first fluid port in said cover, said cylinder having a second port,

cap means coupled with a second end of said cylinder, said cap means having an aperture therein through which said piston rod extends for engagement with said second handle, and locking means intercoupling said cap means and said second end of said cylinder for enabling said cap means to be readily removed from said cylinder for removal of said piston for cleaning of said pump.

7. A pump as in claim 6 wherein

said means coupling said handles together includes cooperating protuberances on said first and second handles forming a readily releasable coupling between said first and second handles.

8. A pump as in claim 6 wherein

said second port is an exhaust outlet and extends through the body of said cylinder substantially normal to the axis of the cylinder, said piston and cylinder are configured to allow said piston to move substantially completely to the cover on the first end of said cylinder, and said exhaust outlet extends through said body at said first end of said cylinder to allow said piston to close said exhaust outlet when said piston is positioned at said first end of said cylinder.

9. A compact pump device comprising

a cylinder having a piston therein and a piston rod coupled with said piston,

a first handle coupled with said cylinder, a second handle coupled with said piston rod, and means coupling said handles together so that movement thereof causes said piston to reciprocate in said cylinder,

first valve means having an inlet therein coupled at a first end of said cylinder, said first end of said cylinder having an exhaust port therein,

biasing means for normally biasing said piston to said first end of said cylinder,

second valve means coupled at said exhaust port, movement of said piston away from said first end of said cylinder causing said first valve means to open and movement of said piston toward said end of said cylinder causing said second valve means to open, and

indicator means coupled with said first valve means for indicating the pressure provided at said inlet by said pump device, said indicator means including body means having a piston member therein and an indicating member coupled with said piston member extending from said body means, said body means having an outlet coupled with said first valve means and having an inlet, said body means including third valve means adapted to be opened by manual movement of said indicating member.

10. A compact pump device comprising

a cylinder having a piston therein and a piston rod coupled with said piston,

a first handle coupled with said cylinder, a second handle coupled with said piston rod, and means coupling said handles together so that movement thereof causes said piston to reciprocate in said cylinder,

first valve means having an inlet therein coupled at a first end of said cylinder, said first end of said cylinder having an exhaust port therein,

biasing means for normally biasing said piston to said first end of said cylinder,

second valve means coupled at said exhaust port, movement of said piston away from said first end of said cylinder causing said first valve means to open and movement of said piston toward said end of said cylinder causing said second valve means to open, and

indicator means coupled with said first valve means, said indicator means including a body having an outlet coupled with said first valve means, an inlet, and a gauge port, a piston chamber coupled with said gauge port, a piston member in said chamber, said piston member including a rod extending from said chamber, said rod having indicia thereon, and said body including an exhaust outlet, third valve means coupled with said body at said exhaust outlet thereof, said piston member including means for contacting said third valve means upon manual movement of said rod.

11. A pump device as in claim 10 wherein

said first valve means includes an adapter coupled with said first end of said cylinder and a wafer valve within said adapter, said adapter having said inlet of said first valve means therein and having means biasing said wafer valve to normally close said last named inlet, and

said second valve means includes a second wafer valve normally closing said exhaust port at said first end of said cylinder, said exhaust port being normal to the axis of said cylinder, and means normally biasing said wafer valve of said second valve means to close said exhaust port.