Air-flow capture and control device for flow measurement

• US 4,231,253 A
• Filed: 06/04/1979
• Issued: 11/04/1980
• Est. Priority Date: 06/04/1979
• Status: Expired due to Term

• Current Assignee: Buford, Buff Ohnhaus
• Original Assignee: Buff Ohnhaus, James D. Faith
• Inventors: Faith, James D., Ohnhaus, Buff
• Primary Examiner(s): Woodiel, Donald O.
• Application Number:
  US06/045,051
• Time in Patent Office: 519 Days
• Field of Search: 73/212
• US Class Current: 73/861.62
• CPC Class Codes: G01F 1/40 Details of construction of the flow constriction devices

Abstract

Four curtains are drawn or released together to set the measuring aperture of an air-flow measuring box at the desired area and the linear velocity of flow through the aperture is measured by a single-probe velometer normally held with the probe tip essentially at the center of the aperture, a perimeter sealing strip blocks unmeasured air flow around the back of the curtains. A box-like hood guides the air flow from a ceiling outlet under investigation to the curtained aperture and is provided with diagonal vanes to keep the measurement from being falsified by cyclonic air movement. The box-like hood folds up for storage or transportation.

Claims

1. Portable apparatus for collecting and guiding an airflow to be measured, comprising:

a first frame (1) mounting an apertured panel (25) and provided with means for varying the open area of the panel aperture while maintaining it in a polygonal shape, said varying means comprising a plurality of movable members (32-35) of sheet material and means (38-42) for moving said members simultaneously and for indicating the aperture area defined by said members;

means (4) supported on said first frame for mounting the probe (8) of an air-velocity-meter adjustably with reference to the center of said aperture and for mounting the indicating portion (9) of said air-velocity-meter on said frame in an attitude making it easily readable by a person holding up said apparatus;

means (27) for sealing said members of said varying means with respect to said apertured panel (25);

a hood (3) foldable into said first frame and having folding legs (46-50) and a second frame (52,12) arranged to be held parallel to said first frame when said hood is erected; and

vanes (71-74) hingedly connected to said legs, firmly engageable together within said hood in the central region thereof, with their surfaces parallel to the axis of said hood when said hood is erected.

2. Portable apparatus as defined in claim 1, in which said movable members of said area varying means are curtains each provided with a roller (65,68) and arranged to pass around said roller so as to permit the end portion of each curtain to be drawn up vertically when said aperture is widened while disposed in a horizontal plane.

3. Portable apparatus as defined in claim 2, in which said polygonal shape of said aperture is square.

4. Apparatus as defined in claim 1 or claim 2, in which said means (4) for mounting said probe (8) constitute means for mounting said probe essentially at the center of said aperture.

5. Apparatus as defined in any one of claims 1-3, in which said vanes (71-74) are arranged so as to nest in parallel pairs, each disposed between a pair of said legs, to facilitate folding of said legs.

6. Apparatus as defined in claim 3, in which said first (1) and second (52) frames are of square contour and in which said legs connect corners of said first and second frames so that when said hood is erected, each of said legs is straight and connects corresponding corners, respectively, of said frames.

7. Apparatus as defined in claim 6, in which each of said legs consists of two members (46,47,48,49) articulated, for swinging in one plane, where they are joined together and pivoted respectively on said frames at the respective other ends of said members for swinging in said plane.

8. Apparatus as defined in claim 7 in which the respective articulated joints of two of said legs are at a different level with respect to the axis of said hood from that at which the respective articulated joints of the other two legs are located when said hood is erected.

9. Apparatus as defined in claim 6 in which each of said vanes (71-74) is made of sheet metal and has a lip (121-124) which is disposed in a plane substantially perpendicular to said hood axis when said hood is erected.

10. Apparatus as defined in claim 9 in which each of one diagonally opposite pair (72,74) of said vanes also has an end lip (97,98) substantially at right angles to the vane surface and running parallel to said hood axis when said hood is erected and a slot (100,101) for passage of the horizontal lip (121,123) of one of the other pair (71,73) of said vanes when all the vanes are engaged together, the vanes of said other pair (71,73) having cooperating notches (95,96) in their respective free ends and having their end portions adjacent to said notches twist-bent to facilitate a firm engagement of said vanes of said last-mentioned pair (71,73).

11. Apparatus as defined in any one of claims 6-10 in which a set of spring (61) each located adjacent to a different one of said legs is provided for urging the free ends of said curtains apart from each other and arranged so as to pull upwards two adjacent corners respectively of two adjacent curtains, and in which apparatus said means (38-40) for simultaneously moving said curtains (32-35) are constituted as means for drawing and holding oppositely disposed pairs (32,34;

33,35) of said curtains together against the force of said springs.