US3367561A - Diaphragm type air pump - Google Patents

Description

Feb. 6, 1968 R. D. BECK ET AL 3,367,561

DIAPHRAGM TYPE AIR PUMP Origianl Filed Nov. 3, 1961 2 Sheets-Sheet 1 1 i 24 i ,34 5% f 23 FIG-l 3 JOHN H. 'GEIGE f ATTORNEYS Feb. 6, 1968 R. D. BECK ET AL I 3,367,561

DIAPHRAGM TYPE AIR PUMP Origianl Filed Nov. 3, 1961 2 Sheets-Sheet 2 ATTORNEYS United States Patent Cfiiice 3,357,561 Patented Feb. 6, 1968 2 Claims. (Cl. 230-20) ABSTRACT OF THE DISCLOSURE This disclosure relates to a vacuum control system utilizing an electromagnetically driven pneumatic pump means for maintaining a vacuum requirement in the system, the pneumatic pump means having an inlet housing body secured to a frame means that carries an electromagnetic motor means that will operate a cantilevered mounted armature relative to the core of the motor means when the coil thereof is energized. The armature is secured to an exhaust chamber body of the pump to move the exhaust chamber body relative to the inlet pump housing in order to oscillate a flexible diaphragm interconnecting the inlet housing body and the exhaust chamber body together. The flexible diaphragm cooperates with one of the housings to define a pumping chamber and the pump is so constructed and arranged that the same will automatically vary its volumetric pumping capacity by changing the effective pumping surface area of the diaphragm even though the diaphragm is being oscillated at a constant frequency by the electromagnetic motor means.

This application is a divisional patent application under Rule 147 of its copending parent patent application, Ser. No. 428,605, filed Jan. 21, 1965, now Patent No. 3,255,956, which, in turn, is a continuation application of its copending patent application, Ser. N0. 149,990, filed Nov. 3, 1961, now abandoned.

A diaphragm pump according to this invention is so constructed that it may be driven by an electromagnetic vibrator motor in an advantageous manner, and this pump has been combined with such a vibrator motor in a novel, useful and effective manner.

However, certain advantages of the diaphragm type air pump may be used when the pump is driven by any other suitable power take off which can produce a substantially linear reciprocating motion of the desired force and magnitude.

An electromagnetic vibrator motor has been provided, according to this invention, of such construction that it can be combined with an air pump in an adjustable manner, so the vibrator motor and the air pump may be effectively driven by the vibrator motor.

Under certain circumstances, the resonance of the vibrator motor and the resonance of the air pump may be combined to provide an elfective combined action. However, under certain other circumstances, the resonance of the vibrator motor and of the air pump need not be used and many of the advantages of this invention may nevertheless be obtained.

The air pump is particularly useful and effective when it is used to produce a vacuum for a vacuum program system, which system requires a substantially constant source of vacuum at a substantially regulated vacuum pressure, and which also may require a variable capacity in the vacuum punip, so the vacuum pump can effectively maintain the desired vacuum with automatically reduced volumetric capacity when no substantial volume of air movement is required in the system, and which pump automatically can increase its volume capacity when a substantial amount of air is to be removed from the program system.

The diaphragm of this air pump is so constructed that it has a relatively large pumping area when the air pump is called upon to remove a substantial amount of air from the vacuum system. The diaphragm construction, and the support therefor is so combined that the diaphragm can automatically reduce its pumping area when it is called upon to maintain a vacuum with a substantially reduced amount of volume of air removal.

Adjustments are provided in the connections between the vibrator motor and the air pump, so the motor and air pump may be connected together in an effective manner. Such adjustments are useful whether the resonance of the vibrator motor and of the pump are to be combined, or whether the resonance of the motor and the air pump are not to be used, and the inherent power of the motor itself is used to drive the pump without regard to any resonance of the two members which may be present or absent.

Accordingly, it is an object of this invention to provide an improved air pump having one or more of the features herein disclosed.

Another object of this invention is to provide an improved electromagnetic vibrator motor having one or more of the features disclosed.

Another object of this invention is to provide a combined electromagnetic vibrator motor and air pump having one or more of the features herein disclosed.

Another object of this invention is to provide a vacuum producing apparatus, which is advantageously connected with a vacuum program system and the like, and having one or more of the features herein disclosed.

Another object of this invention is to provide an improved vacuum producing method.

Another object of this invention is to provide an improved method of producing electromagnetic vibrating power, having one or more of the features herein disclosed.

Another object of this invention is to provide an improved method of producing electromagnetic vibrating power to operate a pumping method, and having one or more of the features herein disclosed.

Another object of this invention is to provide a method of vacuum program control, and having one or more of the features herein disclosed.

Other objects are apparent from this description and from the accompanying drawings in which:

FIGURE 1 is a side View of the electromagnetic vibrator motor and air pump in one of the many positions in which it may be operated.

FIGURE 2 is an end view taken along line 2-2 of FIGURE 1.

FIGURE 3 is an upward view taken along the line 33 of FIGURE 1.

FIGURE 4 is a top view taken along the line 4-4 of FIGURE 1.

FIGURE 5 is a cross section taken along the line 5-5 of FIGURE 1, and showing mainly the armature and its supporting spring structure.

FIGURE 6 is an enlarged longitudinal cross section of the air pump.

FIGURE 7 is a side view of the intake valve, and also may be representative of a side view of the exhaust valve.

FIGURE 8 is an enlarged cross section of a portion of FIGURE 6 and showing a portion of the exhaust valve construction.

FIGURE 9 is a view similar to FIGURE 8 but showing the somewhat similar construction of the intake valve construction.

FIGURE is a diagrammatic view showing a wiring construction which may be used to energize the magnetic motor.

FIGURE 11 is a diagrammatic view showing the application of the magnetic motor and air pump to a portion of a program vacuum operated system.

FIGURE 12 is a top view of a portion of FIGURE 11.

FIGURE 13 is a cross section of a portion of another embodiment of the exhaust chamber body shown in FIG- URE 6.

Certain words of indicating direction, relative position, etc., are used in this application for the sake of brevity and clearness of description. However, such words are used mainly in connection with the directions and relative positions shown in the drawings, and it is to be understood that such words are equally applicable to structures which do not have the particular direction, relative position, etc., which are shown in the drawings. Examples of such words are upper, lower, vertical, horizontal, etc.

In the drawings, a diaphragm type air pump and an electromagnetic vibrator motor 22 may form a motorpump unit 23 and may have means 24 of assembling them in appropriate relationship so the motor may drive the pump in an improved manner. However, as previously indicated, many of the advantages may be obtained where the drive motor may be of other construction, such as a rotary type motor or any other device, from which a suitable power take-otf would produce a substantially linear reciprocating motion of the desired force and magnitude.

The vibrator motor may comprise a coil 26 and a laminated, U-shaped, iron core 28, having poles 30 and 32. The motor and pump may be mounted on a base 34, which may be above, below, or to the side of the motor and pump. The motor may have a metallic armature 36, which may be rectangular in shape, and relatively thin, when compared to its side area, as illustrated. The armature may be supported by a fiat spring 38 which is mounted on the base 34 between the spring pivot supports 40 and 42.

If desired, the weight of the armature, distribution of its mass, and the rate and length of the spring 38 may be designed for mechanical resonance with the impulse forces of the motor 22, such as at a frequency of 60 cycles per second.

Rectangular slots 44, slightly larger in width and length than the cross section of the poles 30 and 32, are provided in the armature 36. These slots 44 permit the armature 36 to oscillate in and out over the core poles 30 and 32 to provide any ampliture for the armature 36, within the maximum stroke of the pump and without interference between the armature and the core.

The slots 44 permit operation without adjustment of the armature and core which might be required to avoid interference which could result from changes in the rate of air flow, or in fluctuations of the supply voltage, the net result of which might be lower output from the pump at normal operating voltage.

Electromagnetic energy to drive the armature at 60 cycles per second may be supplied to the core 28, FIG- URE l0, and the coil 26, by connection to a conventional 115 volt, 60 cycle, AC power supply 46, with a rectifier 48 in one side of the AC line. With suitable redesign of the armature and spring, the motor and the pump support, the construction may be made to operate without the rectifier 48 at 120 cycles per second when connected to a 115 volt, 60 cycle, AC power supply.

When the pump is operated at 60 strokes per second, however, spring length may be greater for a specific width and thickness of the spring than when operated at 120 strokes per second. This permits a longer stroke of the pump from a specific energy input to the coil. The lower operating frequency also will increase pump life.

The air pump 20 may be mounted on the pump bracket 50, which is fastened to the base 34. If desired, the bracket may be resilient and may be fastened adjacent the spring pivot supports 40 and 42, and held by screws 52.

If desired, the bracket 50 when flexible may have a mechanical resonance equal to the impulse frequency of the motor 22, such as of approximately 60 cycles per second, which serves to increase pump stroke and output.

The base 34 preferably may be rigid, to eliminate undesirable twisting of the base which might otherwise occur as the armature moves in and out past the ends of the core.

The pump 20 may be held in a notch 54 in the end of the bracket 50 which notch receives the inlet conduit 56, FIGURE 6. A washer 58 may be placed around the inlet conduit 56 and then the nut 60 may be threaded on the inlet conduit 56 to clamp the bracket 50, washer 58 and pump body 62 firmly together.

The pump 20 may be connected to the armature 36 by a threaded connecting rod 64 which may be attached to the armature by means of a grommet 66 which may be made of neoprene or other suitable resilient material.

The grommet 66 may be placed around the connecting rod 64 and inside the opening 68 in the narrowed circular portion 70 of the armature 36. The grommet 66 may be tightened to a desirable tightness by the nuts 72 and 74.

The lock nut 76 may secure the threaded connecting rod 64 to the exhaust chamber body 78 of the pump 20.

Longitudinal adjustment between the motor 22 and pump 20 is thus provided.

The grommet 66 may be used to absorb most of the .arcuate motion of the connecting rod 64 and provide what is essentially a linear reciprocating motion to drive the pump for increased pump efliciency. The durometer hardnes of the grommet and the degree to which it is compressed by the connecting rod 64 and the fastening nuts 72 and 74 may be chosen and adjusted to produce desirable pump performance. In general, the lower the durometer hardness and the less compressive force of the nuts 72 and 74 on the grommet 66, the higher will be the pump output within the practical limits of the assembly.

The exhaust valve assembly 86, FIGURES 6 and 8, includes a circular clamping disc 92 which can telescope into the circular recess 94 of the pump body 62. An exhaust valve retainer body 96 may be placed on the other side of the diaphragm 82. The disc 92, diaphragm 82 and retainer body 96 may be clamped together by a tube 98 with the flange 100 at one end and an exhaust valve seat flange 102 at the other end of tube 98. The exhaust valve assembly 86 is secured together by the tube 98 and is threadedly secured at 104 to the exhaust chamber body 78.

The exhaust valve assembly 86 has a valve retaining or receiving groove 106, FIGURE 8, which has side walls 108 and which are slightly wider than the thickness of the exhaust valve 84. The valve seat 102 extends leftward in FIGURE 8 slightly beyond the plane 109 of groove side wall 110 a suflicient distance to cause the left edge 112 of the valve 84 to bear lightly on the side wall 108 and cause a small closure force of the side 1114 of the valve 84 against the exhaust valve seat 102.

The corners 116 and 118 may be sharp. The corner 120 may have a .005 inch radius.

An annular undercut area 122 is produced between the valve seat 102 and the groove wall 110. This area 122 reduces valve noise by permitting the valve to contact only the small area of the valve seat 102. In addition, it provides an expansion volume at 122 for the air passing through openings 123 in valve disc 84, to reduce air velocity. This eliminates much of the objectionable noise occurring in pumps which depend only upon air pressures to seat the valves.

The inlet valve 80, FIGURE 9, may be identical to the exhaust valve 84 and may cooperate with groove walls 108A, 110A, valve seat 102A, etc., which are substantially identical to correspondingly numbered parts of FIGURE 8 and which have the suflix A omitted. However, the corner 124 of FIGURE 8 may be sharp, Whereas the corner 124A of FIGURE 9 may have a slight radius, such as a inch radius. The openings 81 in valve disc 80 may be identical with the openings 123 in valve disc 84.

The shape and dimensions of the pump body 62 have been designed for high volumetric efliciency in comparison with the pump con-figuration and the stroke characteristics.

An example is the clearance volume provided at 94 for the clamping disc 92 to clamp the diaphragm 82 and exhaust valve assembly 86.

In a typical operation of the pump 20, starting from a neutral position, as shown in FIGURE 6, with the pump being driven in a substantially simple harmonic motion, such as would be provided by vibrator motor 22, the force applied on the connecting rod 64 moves the diaphragm 82 and the associated parts leftward away from the pump body 62. The pressure inside the suction chamber 125 of the pump is then reduced. This causes the exhaust check valve 84 to seal tightly against its seat 102, and the inlet check valve 80 to move leftward away from its seat 102A and to allow air to flow through the inlet connection 56 into the pump 20. As the limit of the stroke is approached, its stroke velocity decreases, causing the rate of change of pressure within the suction chamber 125 of the pump to decrease until at the end of the leftward stroke the stroke velocity is O, the pressure drop across the inlet valve 80 is 0, and the inlet valve 80 is closed. Upon reversal of the diaphragm motion to start the rightward stroke, resulting from the energy stored in the leaf spring 38 and in the diaphragm 82, the pressure within the chamber 125 of the pump increases, forcing the exhaust valve 84 to open. Air is discharged from the tube 98 in the exhaust chamber 88, creating a slight back pressure which, in combination with the construction of the chamber 88, has a muffiing effect on the exhaust noise. Air from the chamber 88 then passes out through the exhaust nipple 90, where further mufliing may be achieved by attaching to the exhaust nipple 90 a suitable length of flexible tubing 91. A small piece of foam rubber 93 may be used in the tubing 91 for additional reduction of noise.

When the pump 20 is to be used as a vacuum pump only, the exhaust chamber 88A, FIGURE 13, corresponding to chamber 88 of FIGURE 6, may be made of powdered metal 78A having density such that the desired air flow at a suitable noise reducing back pressure occurs directly through the powdered metal wall 7 8A. The chamber 83A of FIGURE 13 may be similar in shape to the chamber 88 of FIGURE 6, with the exception that the exhaust nipple 90, pipe 91, and foam rubber 93 may be omitted, in which case the air filters out through the casing wall 78A.

In general, small air pumps can be very noisy in their operation, if not designated properly. In the air pump of this invention, a unique design of valving has been provided to reduce noise. Both of the valves 80 and 84 are circular discs, as shown in FIGURE 7, and are retained at their peripheries in the grooves 106 and 106A, which have been described.

In the construction shown and described herein, the valves 80 and 84 seat on narrow annular seats 102 and 102A respectively, which extend leftwardly, as illustrated in the drawings, slightly beyond the plane of the peripheral retaining grooves 110 and 110A. The annular areas 122 and 122A between the valve seats 102 and 102A and peripheral retaining groove walls 110 and 110A are undercut for reasons described herein.

In the pump assembly, the leftwardly extended seats 102 and 102A cause the valves 84 and to assume an almost imperceptible cupped shape, thereby exerting a small closure force on seats 102 and 102A by reaction on the surfaces 112 and 114, and 112A and 114A, respectively. This makes the valves return naturally to a closed position before, but near, the end of the pump stroke when the velocity and pressure drop across the valves are approaching 0. In this manner, valve slap is minimized.

The undercut, annular areas 122 and 122A reduce the noise by permitting the valves to contact only the small area of the valve seats 102 and 102A. In addition, the areas 122 and 122A provide an expansion volume respectively to reduce air velocity noise of the air passing through the openings 81 and 123. This eliminates much of the objectionable noise occurring in pumps which depend only upon changes in air pressure to seat the valves.

Another advantageous feature of the pump 20 and vibrator motor 22 is the unique dynamic operating characteristic which can be obtained by means of the angled pole faces 150 and 152. Such angled faces are provided on both of the poles 30 and 32. These angled pole faces of the laminated core 28 cooperate with the amount of concavity of the pump body 62 at the conical portion 154. The concavity 154 may be 15, more or less, with respect to the normal central perpendicular position of the diaphragm 82, as illustrated in FIGURE 6. With the pump operating under minimum air flow, or no flow conditions, with a maximum pressure differential or vacuum across suction chamber 125 to the exhaust chamber 88 of the pump, the resilient, flexible diaphragm 82 will be forced rightwardly against the pump body concave or conical surface 154 at the diaphragm periphery. The effects of this are: (l) the effective working area of the diaphragm 82 is reduced as the pressure differential increases; (2) the center of oscillation of both the diaphragm 82 and of the armature 36 are moved rightwardly, that is, away from the core pole faces and 152; and (3) the changing armature position results in an increase in the average air gap, the magnitude of which is determined by the angularity of the pole faces 150 and 152, resulting in a reduction in the electromagnetic force of attraction. The combination of these three effects provides a unique method of limiting the maximum pressure dif ferential without sacrificing performance at the maximum flow conditions when a substantial amount of air is required to be moved away from the vacuum program system and the like at a much lower pressure differential. In addition, the magnitude of the maximum pressure differential can be varied as desired over a wide range, by positioning the armature with respect to the core by adjusting the position of the nuts 72 and 74, and the position of the rod 64 and the nut 76, to provide a smaller or larger air gap, and a corresponding smaller or larger pumping capacity, as desired.

When greater air flow volume is required to be removed from the vacuum system, the reduced pressure differential across the pump automatically allows the diaphragm 82 to have a greater working area because it operates farther away from the concavity 154. Also it has a more leftward center of oscillation with a reduced average air gap between the armature 36 and the core 28, which results in a greater or stronger electromagnetic force and a larger stroke.

In this manner, the relationship of the concavity 154 with respect to the diaphragm 82 provides automatic reduction of pump stroke after the desired vacuum or pressure differential has been obtained by the contact of a portion of the diaphragm 82 with the concavity 154. However, when air in larger volume is desired to be removed from the system, when the vacuum has been partially reduced in the system, then the diaphragm 82 operates farther from the concavity 154, to provide a larger effective diaphragm area and also a longer stroke of the diaphragm, to produce a greater volumetric pumping power in the pump 20.

In FIGURES 11 and 12 a program system 159 is shown wherein a card or film 160 passes over a smooth surfaced block or reading head 162 with a smooth reading surface 164.

The reading head 162 has one or more discharge passageways 166 with discharge ports 168 at the reading surface 164. The discharge passageways 166 are connected by resilient plastic pipes 167, if desired, respectively with one or more vacuum motors or actuators 170 which operate various levers, switches, etc., of a machine such as a washing machine.

The reading head 162 has one or more intake pass-ageways 172 which have intake or suction ports 174 at the reading surface 164. The passageways 172 may merge into a common suction passageway or manifiold 176 which is connected by a resilient plastic pipe 177, if desired, to the intake 156 of the motor pump unit 23, such as disclosed in FIGURES 1-10 and 13.

The card or film 160 may have a plurality of indentations or closed inverted channels 176 which bridge two or more ports such as ports 168 and 174, as illustrated in FIGURES 11 and 12. The margins of the indentations 176 form a seal with the reading surface 164 and form a fluid connection between the respective vacuum actuator 170 and the source of vacuum or motor pump unit 23.

The indentations 176 in each of the rows 178 and 180 are sufficiently close to maintain a substantially constant bridging action between the ports 168 and 174 as the indentations pass over the ports. This is accomplished by making the space between the indentations of the particular row narrower than the diameter of the ports, if desired.

When a particular vacuum actuator 170 has been energized by being subjected to a vacuum to pull on its respective diaphragm 171, such actuator 170 may be deenergized by breaking the vacuum in its respective passageway 166 to allow its diaphragm 171 to be pulled out by combined atmospheric and spring action or the like. The vacuum may be broken by causing a hole 182, in the film 160, to pass over the respective port 168. This permits atmospheric air to enter the respective passageway 166 to allow the respective diaphragm to move outwardly.

Ordinarily the corresponding suction port 174, pposite the hole 182, is not uncovered so the film 160 prevents the breaking of the vacuum in the passageway or manifold 176 which is connected to the vacuum pump 20.

Because of the relatively small size of the vacuum chambers in actuators 170 and of the respective passageways 166, only a small volume of air is introduced into the system through the hole 182. In view of this the pump ordinarily has long periods of time when it operates to maintain a vacuum without pumping any material amount of air. The ability of the diaphragm 82 to reduce its eifective pumping area by contact with the concave wall 154 permits the pump 20 to operate with a very small power consumption.

For a control system for a domestic automatic clothes washing machine, the following sizes more or less have been found satisfactory.

Diaphragm diameter AA=% Diameters of valves and 82,

Diameters of valve holes 81,

Other parts of the pump, etc., may be of proportional size.

It is thus to be seen that new and useful constructions and methods have been provided.

While the form of the invention now preferred has 'been disclosed as required by statute, other forms may be used, all coming within the scope of the claims which follow.

What is claimed is:

1. In combination: a vacuum program control system having a variable air volume removal requirement; an electromagnetically driven vacuum air pump connected to said system, said pump having a housing and a flexible diaphragm cooperating together to define a pumping chamber, said diaphragm being oscillated at a constant frequency relative to said housing by an electromagnetic motor means to cause said air removal for said system; and means automatically varying the air volume removal capacity of said pump in response to the air volume removal requirement of said system by changing the effective pumping surface area of said diaphragm even though said diaphragm is still being oscillated at said constant frequency by said motor means.

2. A method of maintaining a vacuum in a vacuum program control system having a variable air volume removal requirement which comprises maintaining said vacuum by a pumping action of an electromagnetically driven diaphragm pump that has its diaphragm oscillated at a constant frequency by an electromagnetic motor means, and automatically varying the volumetric capacity of said pumping action in response to said variable air volume removal requirement by changing the effective pumping surface area of the diaphragm of said pump even though said diaphragm is still being oscillated at said constant frequency by said motor means.

References Cited UNITED STATES PATENTS 1,265,928 5/1918. McClymont 23 013 1,394,887 10/1921 Cooper 230-20 2,018,111 10/1935 Ba'bitch 230 2,471,796 5/1949 Thiberg 230---162 2,890,810 6/1959 Rohling 230170 3,039,399 6/1962 Everett 103-38 X FOREIGN PATENTS 956,466 8/ 1949 France. 990,042 5/ 1951 France.

DONLEY I. STOCKING, Primary Examiner.

LAURENCE V. EFNER, Examiner.

W. L. FREEH, Assistant Examiner.

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