US3722526A

US3722526A - Pneumatic timing means

Info

Publication number: US3722526A
Application number: US00071491A
Authority: US
Inventors: K Henningsson
Original assignee: Atlas Copco AB
Current assignee: Atlas Copco AB
Priority date: 1969-09-19
Filing date: 1970-09-11
Publication date: 1973-03-27
Anticipated expiration: 1990-03-27
Also published as: FR2062931B3; CA920896A; SE338509B; DE2045306A1; FR2062931A7; GB1292360A; NL7013611A; JPS4934226B1

Abstract

A pneumatic timing means, which is particularly suitable for use as a delay device or a pulse device at the output end of pneumatic control circuits, especially such pneumatic control circuits which are of the integrated fluidistor type. The pneumatic timing means has very few movable parts, which makes it very reliable, and its exhaust or draining path is very short and has very little flow resistance in the open condition, which makes the exhaustion or draining after each operation of the timing means very quick. The timing means includes first and second diaphragms, preferably integrally formed, for selectively opening and closing the exhaust channel and the output channel, respectively.

Description

United States Patent 1 1 Henningsson [54] PNEUMATIC TIMING MEANS [75] Inventor:

Sweden [73] Assignee: Atlas Copco Aktiebolag, Wacka,

Sweden [22] Filed: Sept. 11, 1970 [21] Appl, No.: 71,491

[58] Field of Search .....137/107, 512.4, 525; 251/15, 251/16, 20, 55, 61.1, 51

[56] References Cited UNITED STATES PATENTS 2,529,028 11/1950 Landon ..251/61.1 X 2,677,390 5/1954 ..25l/61.1 X 3,010,476 11/1961 ....137/5I2.4 3,354,902 11 /1967 Obermaier... ...137/525 X 3,543,792 12/1970 OKeefe ..25 I/55 X Karl Giista Henningsson, l-landen,'

[ 1 Mar. 27, 1973 Primary Examiner-Martin P. Schwadron Assistant Examiner-David J. Zobkiw Att0rneyFlynn & Frishauf [57] ABSTRACT A pneumatic timing means, which is particularly suitable for use as a delay device or a pulse device at the output end of pneumatic control circuits, especially such pneumatic control circuits which are of the integrated fluidistor type. The pneumatic timing means has very few movable parts, which makes it very reliable, and its exhaust or drainingpath is very short and has very little flow resistance in the open condition, which makes the exhaustion or draining after each operation of the timing means very quick. The timing means includes first and second diaphragms, preferably integrally formed, for selectively opening and closing the exhaust channel and the output channel, respectively.

15 Claims, 2 Drawing Figures PATENTEDHARZ 7 I873 57 i 7% y p 2 #9 .0 2 19 h 2 3 m (W h E 6 PNEUMATIC TIMING MEANS The present invention relates to a timing means for delaying or pulsing a pneumatic signal, which consists of a pressure rise.

Previously known delay devices and pulse devices for pneumatic signals have many components, and thus they are expensive to produce. Besides, the valves in known delay devices and pulse devices have such a construction that a relatively high signal pressure is required for a reliable and accurate function.

, One object of the present invention is to provide a timing means which eliminates the deficiencies mentioned above.

Another object of the invention is to provide a simple and reliable timing means which can be used either as a delay device or as a pulse device. Such a timing means offers advantages with regard to production economy and assembly in series (or mass) production of the timing device.

Another important object of the invention is to provide a timing means offering a markedly shortened quick-exhaust time paired with a reliable function at low signal pressures. The novel timing means will thus be directly combinable with and connectable to fluidistor circuits and will work with an air consumption normal for fluidistor operation.

SUMMARY OF THE INVENTION These objects are attained by providing according to the invention a pneumatic timing means, comprising an input channel, a throttling means and a first cavity, which are so arranged that a pneumatic signal, which is the input signal of the timing device and which is supplied through the input channel and the throttling means to the first cavity, produces a delayed pressure rise in the first cavity in a manner known per se, an output channel and an exhaust valve disposed in a second cavity for rapid exhausting, each time the input signal ceases, of the first cavity via a channel leading from the first cavity to the exhaust valve characterized in that the exhaust path of the first cavity after the exhaust valve comprises a passage leading from the second cavity directly out to the surrounding atmosphere, that the exhaust valve is a diaphragm valve communicating at the one face thereof with the input channel and movable with the other face thereof to close or to open the exhaust path, and that another diaphragm is provided to selectively open and close the output channel responsive to the pressure rise.

Further objects and advantages will appear from the following detailed description of embodiments of the invention taken in conjunction with the accompanying drawings, in which FIG. 1 shows an embodiment of the timing device as a delay device and FIG. 2 shows an embodiment of the timing device as a pulse device.

The timing device comprises a housing or casing 2, in which both the first cavity 3, the choke or throttling means 1, the exhaust valve 7 in the second cavity, the channel 4 which leads to the choke means 1, and the

exhaust channels

5 and 6 which run from the first to the second cavity and from the second cavity to the environment, respectively, are arranged.

In the embodiments shown the housing 2 is closed by means of a lid or a plate 18, which contains the input channel 16 and the output channel 17.

The choke means 1, which can be of a fixed or an adjustable type, is situated in the wall of the housing 2 and has direct connection to the first cavity 3. The choke means 1 and the cavity 3 constitute the time measuring means or the timer of the timing device in a manner known per se.

The exhaust channel 5, which leads from the first cavity 3, has its outlet in the second cavity in the valve seat of the exhaust valve 7, whereby the outlet of the channel preferably constitutes the valve seat of the exhaust valve in the manner which is shown on the drawings.

The exhaustion of the first cavity 3 goes faster than by previously known timing devices each time the input signal ceases, partly because the exhaust valve is a diaphragm valve, which can be constructed with little flow resistance in the open condition, partly because the exhaust valve is situated in the wall of the housing 2 close to the first cavity 3, so that the exhaust channel 5 between the first and the second cavity is short, and partly because the exhaustion takes place directly to the environment via the exhaustion outlet 6 and not, as by conventional timing devices, back to the signal source.

The input channel 16 of the timing device has two openings, of which the first opening 12 leads to the channel 4 which runs to the choke means 1 and the second opening 11 leads to the second cavity on the control side of the diaphragm 9 of the exhaust valve 7 for control of the exhaust valve, so that the exhaust valve 7 is kept closed is the input signal is present. The elasticity of the diaphragm 9 causes the exhaust valve to be in its open condition when no input signal is present.

In the timing device of FIG. 1 the output channel 17 has direct connection with the first cavity via an opening 14.

By the embodiment of FIG. 1 the diaphragm 9 of the exhaust valve 7 is shaped in such a manner that it also serves as a tightening element 10 between the housing 2 and the plate 18, whereby the tightening element closes a third opening 13 from the input channel and an exhaust outlet 15 from the output channel 17, which openings are used in the embodiment which Is shown in FIG. 2.

The diaphragm 9 and the tightening or sealing part 10 are, as an example, made of rubber or some kind of elastic and tightening material.

The plate 18 suitably consists of a fluidistor circuit plate.

The delay device according to FIG. 1 works in the following way. When a pneumatic signal in the form of a pressure rise is supplied to the input channel 16, the diaphragm 9 in the exhaust valve 7 is affected in such a way via the second opening 11 that the exhaust valve blocks the exhaust path. Via the first opening 12 air then flows from the input channel through the channel 4 and the choke means 1 into the first cavity 3. Because of the choke means 1 the pressure rise in the cavity 3 is delayed in relation to the input signal fed to the input channel 16 in a manner known per se. The delayed pressure rise is the output signal of the delay device,

and this output signal further goes through the opening 14 and the channel 17.

The embodiment of FIG. 2 of the timing device, which as is mentioned above is a pulse device, is used to generate an output pulse having a predetermined pulse width from an input signal, which can be of a continuous type or of a pulsed type.

The pulse device is different from the delay device in that a signal interrupting or breaking valve 20 is arranged in the first cavity 3, so that the connection between the first cavity 3 and the opening 14 of the output channel 17 is closed and that the signal breaking valve 20 can open and close a signal connection from the input channel 16 to the output channel 17. The signal breaking valve 20 is a diaphragm valve, whose valve seat suitably is the plate 18. By absence of an input signal the diaphragm 23 of the signal breaker is pressed against the valve seat by a resilient means 19, which suitably is a helical spring which is placed at the control side of the diaphragm, ie the side which does not face the valve seat, as is shown in FIG. 2, whereby a tightening exists around the opening 14 of the output channel 17 and the signal connection between the input channel and the output channel is broken.

In the embodiment shown in FIG. 2 the diaphragm 23 of the signal breaking valve and the diaphragm 9 of the exhaust valve are combined in one piece, which furthermore includes the sealing part between the housing 2 and the plate 18. Thus the change of the timing device from a delay device into a pulse device can be done by exchanging the sealing part 10 of the delay device with the sealing part 10' of the pulse device.

The signal breaker diaphragm 23 of FIG. 2 on its seat side is provided with a tighteningring 24 and on its control side with a projection 22 or another reinforcement which opposes deformation because of the spring 19 coupled to the portion of the diaphragm which comprises the sealing ring 22. The projection 22 has a projecting part 21 which serves as a guide for the spring 19.

The sealing part 10 has a hole which gives connection between the exhaust opening 15 of the output channel to a bleed or leakage throttling means 8, which is arranged in the wall of the timing device.

The pulse device according to FIG. 2 works in the following manner. When an input signal is fed via the input channel 16, the exhaust valve 7 is closed in the same manner as in the delay device. At the same time the signal breaker valve 20 is opened by the signal pressure which is applied to the seat side of the diaphragm 23 via the third opening 13 of the input channel 16, whereby a signal connection is established between the input channel 16 and the output channel 17 via the opening 13, the signal breaker valve 20 and the opening 14. Because air flows from the input channel 16, through the opening 12, the channel 4 and the choke means 1 into the first cavity 3 a successive equalizing of the pressure difference between the input signal pressure and the pressure within the cavity 3 takes place. After a certain time, which may be adjustable by means of the choke means 1, the pressure difference is so small that the resilient means 19 closes the signal breaker valve 20. In this way an output pulse without delay and with substantially the same pulse width as the delay time of the delay device is achieved.

At the closing instant there occurs an almost stepwise rise of the force onto the seat side of the diaphragm because the area which is affected by the input signal pressure decreases with the area which is surrounded by the sealing ring 24 at the signal side of the diaphragm. Therefore it is expedient that the area which is surrounded by he sealing ring 24 forms a substantial part of the area of the diaphragm. A ring with a large diameter also has the advantage that is the resilient means 19 causes a moment which acts to twist the diaphragm obliquely in relation to the valve seat or the plate 18, the diaphragm is twisted back into its right position during the closing.

The output channel 17 is exhausted after the closing of the signal breaker valve 20 via the bleed throttling means 8, and the first cavity 3 is exhausted by means of the exhaust valve 7 in the same manner as in the delay device, when the input signal ceases.

By virtue of the construction of the timing device according to FIGS. 1 and 2, the housing 2 of the timing device can be very simply exchanged with another component which gives direct signal connection between the input channel 16 and the output channel 17.

What we claim is:

1. A pneumatic timing means comprising:

an input channel;

a throttling means;

a first cavity;

passage means interconnecting said input channel,

said throttling means and said first cavity in series; an output channel connected to said first cavity; a second cavity; an exhaust channel connected to said first and second cavities;

an exhaust passage downstream of said exhaust channel; an exhaust valve disposed in said second cavity for controlling the communication between said exhaust channel and said exhaust passage, said exhaust valve including a first diaphragm forming a partition in said second cavity, said exhaust channel and exhaust passage opening on the same side of said diaphragm, and said exhaust valve further including means communicating the other side of said diaphragm with said input channel, said diaphragm selectively opening and closing said exhaust channel; signal interrupting valve in said first cavity, said signal interrupting valve including a second diaphragm forming a partition in said first cavity between said throttling means and said output channel, and spring means in said first cavity for biasing at least a portion of said second diaphragm to a position closing said output channel, the part of said first cavity adjacent said biased second diaphragm portion and on the output channel side of said second diaphragm having communication with said input channel.

2. A pneumatic timing means according to claim 1 wherein said first diaphragm communicates at one face thereof with said input channel and is movable to open or close said exhaust channel with the other face thereof.

3. A pneumatic timing means according to claim 1 wherein said first and second diaphragrns are integrally formed as a single diaphragm member.

4. A pneumatic timing means according to claim 3 wherein said input and output channels are formed in a plate; said throttling means, first cavity, second cavity, passage means and exhaust channel are formed in a housing; and said integrally formed first and second diaphragm members further include means interposed between said housing and said plate for sealingly connecting said housing and plate.

5. A pneumatic timing means according to claim 1 wherein the part of said first cavity around said biased second diaphragm portion and on the output channel side of said second diaphragm is in communication with said input channel.

6. A pneumatic timing means according to claim 1 wherein said spring means is a spring interposed between said second diaphragm and a wall portion in said first cavity, and a sealing ring is provided on said second diaphragm on the side thereof opposite to said spring.

7. A pneumatic timing means according to claim 6 wherein said second diaphragm includes a projection which is engaged with said spring, said spring being interposed between said projection and said wall portion in said first cavity.

8. A pneumatic timing means comprising:

a plate;

an input and an output channel in said plate;

a housing;

a throttling means in said housing;

a first cavity in said housing open to one end portion thereof;

passage means in said housing connecting said throttling means with said first cavity and' with said input channel;

a second cavity in said housing open at said one end portion thereof;

an exhaust channel leading from said first cavity to said second cavity;

an exhaust passage in said housing downstream of said exhaust channel and leading from said second cavity directly out to the surrounding atmosphere;

a diaphragm member sealingly connected between said one end portion of said housing and said plate with a first portion of said diaphragm member disposed as a partition across said second cavity, said diaphragm member having a first opening therein for connecting said output channel with said throttling means, and a second opening therein in the path of said passage means between said input channel and said throttling means; and

a connection between said input channel and said partition for moving said partition to close or to open said exhaust channel.

9. A pneumatic timing means according to claim 8 in which said exhaust channel has a mouth opening in said second cavity which provides a valve seat for said first portion of said diaphragm member.

10. A pneumatic timing means comprising:

a plate; an input and an output channel in said plate; a housa throttling means in said housing; a first cavity in said housing open to one end portion thereof; passage means in said housing connecting said throttling means with said first cavity and with said input channel;

a second cavity in said housing open at said one end portion thereof;

an exhaust channel leading from said first cavity to said second cavity;

a diaphragm member sealingly connected between said one end portion of said housing and said plate with a first portion of said diaphragm member disposed as a partition across said second cavity, said diaphragm member having an opening therein in the path of said passage means between said input channel and said throttling means;

a connection between said input channel and said partition for moving said partition to close or to open said exhaust channel; and

signal interrupting valve in said first cavity, said signal interrupting valve including a second diaphragm forming a partition in said first cavity between said throttling means and said output channel, and spring means in said first cavity for biasing at least a portion of said second diaphragm to a position closing said output channel, the part of said first cavity adjacent said biased second,

diaphragm portion and on the output channel side of said second diaphragm having communication with said input channel.

11. A pneumatic timing means according to claim 10 wherein both said second diaphragm of said exhaust valve and said first portion of said diaphragm member are integral parts of said diaphragm member.

12. A pneumatic timing means according to claim 10 further comprising a bleed throttling means between said output channel and the surrounding atmosphere.

13. A pneumatic timing means according to claim 10 in which said spring means is a spring interposed between said second diaphragm and a wall portion in said first cavity, and a sealing ring is provided on the face of said second diaphragm opposite to said spring.

14. A pneumatic timing means according to claim 13 wherein said second diaphragm includes a projection which is engaged with said spring, said spring being interposed between said projection and said wall portion in said first cavity.

15. A pneumatic timing means according to claim 13 in which said plate around the inlet of said output channel provides a valve seat for said sealing ring.

Claims

1. A pneumatic timing means comprising: an input channel; a throttling means; a first cavity; passage means interconnecting said input channel, said throttling means and said first cavity in series; an output channel connected to said first cavity; a second cavity; an exhaust channel connected to said first and second cavities; an exhaust passage downstream of said exhaust channel; an exhaust valve disposed in said second cavity for controlling the communication between said exhaust channel and said exhaust passage, said exhaust valve including a first diaphragm forming a partition in said second cavity, said exhaust channel and exhaust passage opening on the same side of said diaphragm, and said exhaust valve further including means communicating the other side of said diaphragm with said input channel, said diaphragm selectively opening and closing said exhaust channel; a signal interrupting valve in said first cavity, said signal interrupting valve including a second diaphragm forming a partition in said first cavity between said throttling means and said output channel, and spring means in said first cavity for biasing at least a portion of said second diaphragm to a position closing said output channel, the part of said first cavity adjacent said biased second diaphragm portion and on the output channel side of said second diaphragm having communication with said input channel.

3. A pneumatic timing means according to claim 1 wherein said first and second diaphragms are integrally formed as a single diaphragm member.

8. A pneumatic timing means comprising: a plate; an input and an output channel in said plate; a housing; a throttling means in said housing; a first cavity in said housing open to one end portion thereof; passage means in said housing connecting said throttling means with said first cavity and with said input channel; a second cavity in said housing open at said one end portion thereof; an exhaust channel leading from said first cavity to said second cavity; an exhaust passage in said housing downstream of said exhaust channel and leading from said second cavity directly out to the surrounding atmosphere; a diaphragm member sealingly connected between said one end Portion of said housing and said plate with a first portion of said diaphragm member disposed as a partition across said second cavity, said diaphragm member having a first opening therein for connecting said output channel with said throttling means, and a second opening therein in the path of said passage means between said input channel and said throttling means; and a connection between said input channel and said partition for moving said partition to close or to open said exhaust channel.

10. A pneumatic timing means comprising: a plate; an input and an output channel in said plate; a housing; a throttling means in said housing; a first cavity in said housing open to one end portion thereof; passage means in said housing connecting said throttling means with said first cavity and with said input channel; a second cavity in said housing open at said one end portion thereof; an exhaust channel leading from said first cavity to said second cavity; an exhaust passage in said housing downstream of said exhaust channel and leading from said second cavity directly out to the surrounding atmosphere; a diaphragm member sealingly connected between said one end portion of said housing and said plate with a first portion of said diaphragm member disposed as a partition across said second cavity, said diaphragm member having an opening therein in the path of said passage means between said input channel and said throttling means; a connection between said input channel and said partition for moving said partition to close or to open said exhaust channel; and a signal interrupting valve in said first cavity, said signal interrupting valve including a second diaphragm forming a partition in said first cavity between said throttling means and said output channel, and spring means in said first cavity for biasing at least a portion of said second diaphragm to a position closing said output channel, the part of said first cavity adjacent said biased second diaphragm portion and on the output channel side of said second diaphragm having communication with said input channel.