Damper

April 28, 1959

F. HONERKAMP ET AL

DAMPER

2,884,005

Filed July 27, 1956

Sheets-Sheet 1

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April 28, 1959

F. HONERKAMP ET AL.

2,884,005

DAMPER

Filed July 27, 1956 3 Sheets-Sheet 2

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April 28, 1959 f. honerkamp et al 2,884,005

DAMPER Filed July 27, 1956 3 Sheets-Sheet 3

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2,884,005

Patented Apr. 28, 1959

United States Patent Office

2,884,005

DAMPER

Friedrich Honerkamp, West Hartford, Conn., Franz J. Kurth, Mamaroneck, N.Y., and Raymond S. Barlow, Hartford, Conn., assignors to Anemostat Corporation of America, New York, N.Y., a corporation of Delaware

Application July 27,1956, Serial No. 600,581

Claims. (Cl. 137—601)

This invention relates to dampers for regulating flow of air through air ducts of ventilating systems and for analogous uses, and has particular reference to improvements in dampers of the collapsible and expansible louver type.

Generally speaking the objects of the invention are to provide a damper of the collapsible and expansible louver type which is very simple in construction; which may be manufactured economically; which has little tendency to create turbulence of the air which it controls and which, hence, operates substantially noiselessly even though the air flowing therethrough may be at high velocity; which offers minimum resistance to flow of air therethrough when its louvers are fully collapsed, and which includes simple means whereby the louvers may readily and easily be collapsed and expanded to regulate the air flow.

With the foregoing and other objects in view, as will become more fully apparent as the nature of the invention is better understood, the same consists in a damper of the collapsible and expansible louver type embodying the novel features of construction, combination and arrangement of parts as are illustrated by way of example in the accompanying drawings and as will hereinafter be more fully described and claimed.

In the accompanying drawings, wherein like characters of reference denote corresponding parts in the different views:

Fig. 1 is a front elevation of a damper constructed in accordance with one practical embodiment of the invention.

Fig. 2 is a side elevation of the damper showing the louvers thereof fully expanded and the damper consequently closed.

Fig. 3 is a view similar to Fig. 2 showing the louvers fully collapsed and the damper consequently fully open.

Fig. 4 is a section taken approximately on the line 4—4 of Fig. 1.

Fig. 5 is a section taken approximately on the line 5—5 of Fig. 2.

Fig. 6 is a vertical section through a portion of the damper showing the same in approximately half open condition; and

Fig. 7 is a view partly in elevation and partly in section, illustrating details of the louver operating means.

Referring to the drawings in detail, A designates, generally, a rectangular frame which defines a passageway for the air to be controlled or regulated and which, as will be understood, is intended to be interposed in an air duct so as to form a part thereof. As shown, said frame may be provided at its front and rear ends with flanges 10 to be riveted, bolted, welded or otherwise fastened to similar duct flanges to incorporate said frame in a duct.

The frame A includes side walls 11, 11 and end walls 12, 12 and, in accordance with the illustrated embodiment of the invention, additionally includes a pair of plates 13, 13 spot-welded or otherwise suitably secured against the inner faces of the side walls 11, 11, respectively.

The plates 13, 13 may appropriately correspond in length and width to the frame side walls 11, 11 and each 5 plate is suitably formed with a pair of inwardly directed, spaced apart ribs 14 and 15 which extend longitudinally thereof and define between them an inwardly opening, longitudinally extending channel 16. Equivalently, the frame side walls 11, 11 may be formed with the ribs 10 14, 15 and the channels 16, in which case the plates 13, 13 are unnecessary. However, for reasons of simplicity and economy in manufacture of the frame A, use of the plates 13, 13 is preferred, particularly since they serve to reinforce and stiffen said frame.

With reference to the direction of flow of air through the frame A, the ribs 14 are located adjacent to the front or upstream end of said frame and the ribs 15 are located rearwardly of said ribs 14 or toward the downstream end of said frame. Said ribs and, hence, the 20 channels 16 extend preferably from end to end of the plates 13, 13.

Within the frame A is a series of duplicate collapsible and expansible louvers, individually designated generally as B, which extend transversely of said frame between 25 the ribs 14, 15 of the plates 13, 13 and which are disposed in side to side spaced apart relationship to each other in a row extending from end to end of said frame.

Each louver B is composed of a first plate, designated as 17, a second plate, designated as 18, a third plate, 30 designated as 19, and a fourth plate, designated as 20.

The plates 17 are relatively wide and preferably are disposed parallel to the general direction of flow of air through the frame A. In other words, said plates 17 preferably are disposed parallel to the end walls 12, 12 35 of the frame A.

Along their side edges all of the plates 17, 18, 19 and 20 of each louver are serrated and rolled to provide hinge eyes 21, and in each louver the hinge eyes along the front or upstream side edge of the first plate 17 are 40 interfitted with the hinge eyes along one side edge of the second plate 18 and are pivotally connected thereto by a hinge pin 22. Similarly, in each louver, the hinge eyes along the rear of downstream side edge of the first plate 17 are interfitted with the hinge eyes along one 45 side edge of the third plate 19 and are pivotally connected thereto by a hinge pin 23. Also, in each louver, the hinge eyes along the other side edge of the second plate 18 are interfitted with the hinge eyes along one side edge of the fourth plate 20 and are pivotally connected ¢0 thereto by a hinge pin 24. Finally, in each louver, the hinge eyes along the other side edge of the third plate and the rear edge of the fourth plate are interfitted with each other and are pivotally connected together by a hinge pin 25.

End portions of the hinge pins 22 of the several louvers B project beyond the ends of said louvers and are engaged in holes in the ribs 14 of the plates 13. Similarly, end portions of the hinge pins 23 of the several louvers project beyond the ends of said louvers and are engaged βθ in holes in the ribs 15 of the plates 13. Therefore, the plates 17 of the several louvers are fixed in the frame A. Said plates 17 are equally spaced apart and their spacing determines, of course, the spaced apart relationship to each other of the several louvers B.

End portions of the hinge pins 24 of the several louvers B also project beyond the ends of said louvers and are engaged in holes in rods 26, 26 which are disposed in and extend longitudinally of the channels 16, 16, respectively.

₇0 The second plates 18 of the several louvers B extend at all times rearwardly from the front edges of the first plates 17 and are of widths suitably greater than the dis2,884,008 tances between said first plates 17 so that they are not swingable about the hinge pins 22 away from said first plates beyond positions in which they form suitable acute angles with said first plates. In other words, the amount of swinging movement of the second plate 18 away from the first plate 17 of any given louver is limited by contact of the rear edge or what may be termed the free edge of said second plate with the first plate 17 of the next adjacent louver, and since in each louver, the second plate 18 extends rearwardly from the first io plate 17, the second plate is not swingable away from the first plate beyond a position in which it forms an acute angle therewith.

In each louver all of the hinge eyes 21 of the plates 17, 18, 19 and 20 are turned or rolled inwardly from 15 said plates so that they are disposed within the louver and do not interfere with smooth flow of air over the louver. In other words, by reason of the hinge eyes 21 being turned or rolled inwardly from the plates 17, 18, 19 and 20, the exterior surfaces of the louvers are smooth, 20 even at the junctions of the plates 17, 18, 19 and 28 with one another.

In each louver the second plate 18 is swingable toward the first plate 17 until the hinge eyes at the junction of said second plate 18 with the fourth plate 20 engage the 25 first plate 17. In this connection, the third plate 19 is of less width than the second plate 18 and the fourth plate 20 is of such width that when the second plate 18 is at its limit of swinging movement toward the first plate 17, the second and the fourth plates 18 and 20, 30 respectively, are disposed substantially in a common plane, substantially parallel to the first plate 17, the third plate 19 extends rearwardly from the first plate 17 and is disposed substantially in the plane thereof, and the louver as a whole is relatively thin, being no thicker 35 than the diameter of a single hinge eye 21 plus the thickness of a single plate.

In order that flow of air through the entire cross sectional area of the air passageway formed by the frame A may be controlled by collapse and expansion 40 of the series of louvers B disposed in said passageway, the first plate 17 of one of the terminal louvers of the series is disposed against one of the end walls 12 of said frame and the other terminal louver of the series has its first plate 17 spaced from the other end wall 12 of said 45 frame an amount equal to the spacing of the first walls 17 of the louvers from each other. Thereby, the second plate 18 of the last mentioned terminal louver cooperates with the last mentioned end wall of the frame A to control flow of air through the space between said last men- 60 tioned terminal louver and said last mentioned frame end wall in the same manner as the plates 18 of the other louvers cooperate with the plates 17 of the louvers next adjacent thereto to control flow of air through the spaces between the louvers. 55

Obviously, by longitudinally shifting the rods 26, the hinge pins 24 may be moved toward and away from the plates 17 to simultaneously collapse and expand the louvers B. When the louvers are fully collapsed, as shown in Fig. 3, the plates 17 and 19 of each louver 60 are disposed substantially in a common plane and the plates 18 and 20 are disposed in another substantially common plane closely adjacent to the plates 17, 19 and substantially parallel thereto. The louvers then are of minimum thickness and the spaces between them are of 65 maximum widths so that minimum resistance to flow of air through the frame A is offered, particularly since the louvers are disposed parallel to the general direction of flow of air through said frame. On the other hand, when the louvers are fully expanded, as shown in Figs. 1 and 70 2, the plates 18 extend fully across the spaces between the plates 17 and across the space between the second mentioned terminal leuver and the second mentioned end wall 12 of the frame A and thereby deny all flow of air through the frame A.

In intermediate positions of collapse or expansion of the louvers B, the rear ends of the second plates 18 of the louvers are more or less spaced from the plates 17 of adjacent louvers and from the second mentioned end 5 wall 12 of the frame A and thereby more or less air is permitted to flow through the damper. In this connection the third plates 19 preferably are of such less widths than the second plates 18 that in intermediate positions of collapse or expansion of the louvers B the rearward divergence of the fourth plates 20 relative to the first plates 17 of the adjacent louvers is such that the angles between said fourth and said first plates permit ready expansion and smooth flow of air between said plates substantially without creation of turbulence or noise. Further in this connection, the general tear-drop, cross sectional shape of the louvers B in intermediate positions of collapse or expansion thereof contributes materially to smooth, non-turbulent, noiseless flow of air through the damper.

While any suitable means may be provided to shift the rods 26 longitudinally to collapse or expand the louvers B, the present invention provides a very simple, practical, inexpensive means for this purpose. A shaft 27 extends transversely across the frame A, forwardly of the louvers B and preferably intermediate the ends of said frame, and is suitably mounted for rotation in the side walls 11, 11 of said frame. On said shaft, outwardly of but closely adjacent to the side walls 11, 11 of the frame A, are mounted two lever arms 28, 28, respectively, which have therein radially extending slots 29 wherein are disposed pins 30 which are fixed to the rods 26 and which extend through slots 31 in the frame side walls 11 and the plates 13. Thus, by rotating the shaft 27 in one direction the rods 26 may be shifted longitudinally in a direction to collapse the louvers B, while by rotating said shaft in the opposite direction the rods 26 may be shifted longitudinally in a direction to expand said louvers. Either or both end portions of the shaft 27 may be provided with a knob or handle or may be formed in any suitable manner for engagement therewith by any suitable implement to effect rotation of the shaft 27.

Preferably the lever arms 28, 28 are of sector shapes so as to cover the slots 31 and prevent escape of air therethrough from the interior of the frame A.

Since the pins 30 are constrained to move in arcs corresponding to the arcs of movement of the hinge pins 22, the slots 31 are of arcuate form having radii corresponding to the radii of the arcs of movement of said hinge pins 22. The channels 16 are, of course, amply wide to permit the rods 26 to partake of the lateral movements which result from their longitudinal shifting movement.

Obviously, only a single rod 26 and only a single lever arm 28 may be used in lieu of the two rods and two lever arms shown as a means of collapsing and expanding the louvers B.

From the foregoing description considered in connection with the accompanying drawings it is believed that the construction and mode of operation of the present damper will be clearly understood and that its advantages will be appreciated. It is desired to point out, however, that while only a single specific structural embodiment of the invention has been illustrated and described, the same is readily capable of specifically different structural embodiments within its spirit and scope as defined in the appended claims.