Automated sequential air sampler

• US 3,884,081 A
• Filed: 06/24/1974
• Issued: 05/20/1975
• Est. Priority Date: 06/24/1974
• Status: Expired due to Term

• Current Assignee: George A. Griffith
• Original Assignee: George A. Griffith
• Inventors: Griffith, George A.
• Primary Examiner(s): Swisher, S. Clement
• Application Number:
  US05/482,140
• Time in Patent Office: 330 Days
• Field of Search: 73/421.5R,425.6,28 23/254R
• US Class Current: 73/863.31
• CPC Class Codes: G01N 1/24 Suction devices G01N1/22 - G01N1/2294 take precedence
• CPC Class Codes: G01N 2001/247 Syringes

Abstract

An automated sequential air sampler that is highly suitable for being remotely situated to obtain a plurality of air samples at predetermined intervals of time over an extended time period, is disclosed. The air sampler includes a plurality of piston pumps that may be in the form of hypodermic syringes. Each pump operates to obtain an air sample whenever a plunger thereof is retracted to have air drawn through an inlet needle into an interior chamber thereof. The inlet to each pump is automatically sealed by having the inlnet needle thereof covered by a septum that is drawn against said inlet with a guide rod on which it is mounted and in response to the plunger reaching the end of its stroke. Sequential retraction of the several syringe plungers is accomplished by operation of a timed retractor assembly which functions to retract individual plungers at predetermined intervals of time.

Claims

1. An air saMpling device for obtaining a plurality of air samples at scheduled time intervals, said air sampling device comprising:

a plurality of piston pumps each having a housing forming an interior chamber, an inlet port member communicating with said chamber, and a plunger which is partially retracted from within said chamber of said housing to draw air into said chamber through said inlet port member when a said piston pump is actuated;

a plurality of sealer means respectively connected to a different one of said pumps for sealing off said inlet port member thereof in response to the plunger thereof being partially retracted from within the chamber thereof by a predetermined distance; and

actuator means for actuating each of said plurality of pumps at scheduled time intervals.

2. The device defined by claim 1, said piston pumps being elongate and further including a stopper arm attached to said plunger, said sealer means including:

an elongated member positioned to extend along the length of a pump associated therewith; and

cover means attached at an end of said elongate member for preventing the passage of air through an inlet port member when positioned to cover said inlet port by being drawn thereagainst in response to being engaged by said stopper arm when said plunger is retracted by said predetermined distance.

3. The device defined by claim 2, said elongate member further including a nub attached on said elongate member to be engaged by said stopper arm, said stopper arm having a central groove for receiving said elongate member therein, said stopper arm engaging said nub on said elongate member to draw said cover means against said inlet port.

4. The device defined by claim 3, said cover means and said nub being movably on said elongate member to allow adjustment of the distance therebetween.

5. The device defined by claim 4, wherein the distance between said cover means and said nub is equal to the distance between the tip of said inlet port member and the outermost end of a plunger when retracted by said predetermined distance.

6. The device defined by claim 2, said sealer means further including:

a positioning arm attached to and extending from said elongate member, said positioning arm having an aperture for receiving said inlet port member which is extended therethrough; and

a guide member attached to said elongate member for slideably moving with respect to said housing of an associated pump for guiding said elongate member when moved with respect to said housing.

7. The device defined by claim 1, said air sampler device further including a mount on which said plurality of piston pumps are removably mounted, said mount configured to have first and second walls connected to a base panel to form a channel therebetween, said plurality of piston pumps being attached to said first wall.

8. The device defined by claim 7, said actuator means including:

a plurality of retention means respectively associated with each of said pumps for maintaining said plunger thereof within said interior chamber of the housing thereof;

a plurality of retracting means respectively connected to a plunger of one of said pumps for retracting a plunger connected thereto by said predetermined distance in response to an associated retention means being released; and

trigger means for releasing each of said retention means at scheduled time intervals.

9. The device defined by claim 8, said retracting means including a spring which is attached between the outermost end of a plunger to be retracted and said second wall of said channel mount.

10. The device defined by claim 8, said retention means including a latching pin and a latching arm having means for receiving said latching pin and thereby maintaining said latching pin in a position preventing retraction of a plunger retained thereby, said latching arm being mounted to be pivoted by said trigger means, whereby said latching pin is released by said latching arm when pivOted by said trigger means to allow retraction of said plunger.

11. The device defined by claim 10, said trigger means including:

an armature;

a plurality of trigger arms mounted on said armature; and

means for rotating said armature about the longitudinal axis thereof whereby said trigger arms are moved to contact and thereby cause pivoting of said latching arms to produce release of corresponding latching pins and consequent retraction of plungers retained thereby.

12. The device defined by claim 11, wherein the trigger arms are mounted on said armature at radial angles with respect to the longitudinal axis thereof that are determinative of the time interval at which individual ones of said plurality of pumps are actuated.

13. The device defined by claim 1, said actuator means including:

a plurality of retracting means respectively connected to a plunger of a different one of said plurality of pumps for retracting the plunger connected thereto at predetermined times; and

timing means for initiating the retraction of the respective plungers of said plurality of pumps in accordance with a predetermined time schedule.

14. The device defined by claim 13, said plurality of retracting means each including a chain and having a predetermined different length, a first end portion of each chain connected to the outermost end of a different one of said plungers, a second end portion of each chain connected to said timing means, said chains being drawn away from said plungers by said timing means.

15. The device defined in claim 14, the lengths of said chains determining the succession in which the plungers connected thereto are retracted, the plunger connected to the shortest chain being retracted first and the plunger attached to the longest chain being retracted last.

16. The device defined by claim 13, said timing means including:

a plurality of sprockets each positioned to be engageable with a different one of said retracting means; and

mover means for driving said sprockets to have said retracting means engaged therewith retract plungers connected thereto at said predetermined times.

17. The device defined by claim 16, said mover means including an armature that is adapted to be rotated about the longitudinal axis thereof, said armature being connected to at least one of said sprockets to cause rotation thereof.

18. The device defined by claim 14, said timing means including:

a plurality of sprockets each positioned to engage a different one of said chains; and

mover means for causing said sprockets to be rotated to have chains engaged therewith drawn in a direction away from the plungers connected thereto to produce retraction of said plungers connected thereto.

19. The device defined by claim 18, said sprockets each having a diameter corresponding to a desired rate at which an associated plunger is to be retracted.

20. The device defined by claim 19, wherein said mover means is connected to rotate said sprockets in unison.

21. The device defined by claim 19, wherein said mover means is connected to rotate said sprockets successively.

22. The device defined by claim 5, said air sampler device further including a mount on which said plurality of piston pumps are removably mounted, said mount configured to have first and second walls connected to a base panel to form a channel therebetween, said plurality of piston pumps being attached to said first wall.

23. The device defined by claim 22, said actuator means including:

a plurality of retention means respectively associated with each of said pumps for maintaining said plunger thereof within said interior chamber of the housing thereof;

a plurality of retracting means respectively connected to a plunger of one of said pumps for retracting a plunger connected thereto by said predetermined distance in response to an associated retention means being released; and

trigger means for releasing each of said retention means at scheduLed time intervals.

24. The device defined by claim 23, said retracting means including a spring which is attached between the outermost end of a plunger to be retracted and said second wall of said channel mount.

25. The device defined by claim 14, said retention means including a latching pin and a latching arm having means for receiving said latching pin and thereby maintaining said latching pin in a position preventing retraction of a plunger retained thereby, said latching arm being mounted to be pivoted by said trigger means, whereby said latching pin is released by said latching arm when pivoted by said trigger means to allow retraction of said plunger.

26. The device defined by claim 25, said trigger means including:

an armature;

a plurality of trigger arms mounted on said armature; and

means for rotating said armature about the longitudinal axis thereof whereby said trigger arms are moved to contact and thereby cause pivoting of said latching arms to produce release of corresponding latching pins and consequent retraction of plungers retained thereby.

27. The device defined by claim 26, wherein the trigger arms are mounted on said armature at radial angles with respect to the longitudinal axis thereof that are determinative of the time intervals at which individual ones of said plurality of pumps are actuated.

28. The device defined by claim 5, said actuator means including:

a plurality of retracting means respectively connected to a plunger of a different one of said plurality of pumps for retracting the plunger connected thereto at predetermined times; and

timing means for initiating the retraction of the respective plungers of said plurality of pumps in accordance with a predetermined time schedule.

29. The device defined by claim 28, said plurality of retracting means each including a chain and having a predetermined different length, a first end portion of each chain connected to the outermost end of a different one of said plungers, a second end portion of each chain connected to said timing means, said chains being drawn away from said plungers by said timing means.

30. The device defined by claim 29, the lengths of said chains determining the succession in which the plungers connected thereto are retracted, the plunger connected to the shorter chain being retracted first and the plunger attached to the longest chain being retracted last.

31. The device defined by claim 29, said timing means including:

a plurality of sprockets each positioned to be engageable with a different one of said retracting means; and

mover means for driving said sprockets to have said retracting means engaged therewith retract plungers connected thereto at said predetermined times.

32. The device defined by claim 29, said sprockets each having a diameter corresponding to a desired rate at which as associated plunger is to be retracted.

33. The device defined by claim 32, wherein said mover means is connected to rotate said sprockets in unison.

34. The device defined by claim 32, wherein said mover means is connected to rotate said sprockets successively.

35. The device defined by claim 33, said mover means including an armature that is adapted to be rotated about the longitudinal axis thereof, said armature being connected to at least one of said sprockets to cause rotation thereof.

36. An air sampling device for successively obtaining a plurality of air samples, said device comprising:

a plurality of air sampler units each including a cylindrical housing defining an interior cavity, an inlet needle connected to said cavity, and a piston-like plunger housed in said cavity for drawing an air sample through said inlet needle into said cavity as said plunger is partially withdrawn from said cavity;

a plurality of stopper means respectively connected with a different one of said sampler units for covering the inlet needle thereof in response to the plunger thereof being withdrawn from the cavity thEreof by a predetermined distance, said stopper means serving to prevent the escape of an air sample through the inlet needle covered thereby;

retractor means connected to the plungers of said sampler units for partially withdrawing each plunger for said predetermined distance in accordance with a selected time schedule.

37. An air sampling device for automatically obtaining an air sample, said device comprising:

an air sampler unit including a housing defining an interior cavity, an inlet needle connected to said cavity, and a piston-like plunger housed in said cavity for drawing an air sample through said inlet needle into said cavity as said plunger is partially withdrawn from said cavity;

stopper means connected with said sampler unit for covering said inlet needle in response to the plunger thereof being withdrawn from said cavity by a predetermined distance, said stopper means serving to prevent the escape of an air sample through said inlet needle covered thereby;

retractor means connected to said plunger for partially withdrawing said plunger for said predetermined distance.