THE DRAWINGS
Several embodiments of the invention are illustrated in the accompanying drawings wherein:
FIG. 1 is an isometric view of a damper-accommodating frame within which is a damper supported in a retracted, air-passing position by a collapsible strut;
FIG. 2 is a view similar to FIG. 1 but illustrating the strut in damper-free position and the damper in extended, air-blocking position;
FIG. 3 is a vertical sectional view illustrating the damper supported by the collapsible strut in its retracted, air-passing position;
FIG. 4 is a view similar to FIG. 3, but illustrating the damper in its extended, air-blocking position;
FIG. 5 is an exploded, isometric view of the collapsible strut and its connecting means for connecting and disconnecting the strut from the frame;
FIGS. 6 and 7 are views similar to FIGS. 3 and 4, respectively, illustrating a different collapsible strut embodiment;
FIG. 8 is an isometric view illustrating the strut of FIGS. 6 and 7 removably connected to the damper-supporting frame;
FIG. 9 is a view similar to FIG. 1, but illustrating another modified embodiment of the collapsible strut;
FIG. 10 is an isometric view illustrating in greater detail the strut of FIG. 9;
FIGS. 11 and 12 are views similar to FIGS. 3 and 4, respectively, but illustrating the modified strut in its damper-supporting and its damper-free positions, respectively;
FIG. 13 is a view similar to FIG. 10 but illustrating the components of the strut in collapsed condition;
FIG. 14 is a view similar to FIG. 1, but omitting the damper support and illustrating adjustable connections for attaching the strut to the damper support.
THE PREFERRED EMBODIMENTS
Apparatus constructed in accordance with the embodiment shown in FIGS. 1-5 includes a frame 1 which may comprise an air duct or a separate frame accommodated within and fixed to such duct. In either event, the frame has opposed side walls 2 joined by top and bottom walls 3. Within the frame is an open sided, open bottom housing 4 within which is mounted an extendible and retractable damper 5 of known construction. The damper has a plurality of pivoted leaves including an anchor leaf 6 fixed to the top wall of the housing 4 and pivotally coupled to leaves 7, 8, and 9 which, in the retracted position shown in FIGS. 1 and 3 occupy a folded condition which enables air to move through the duct past the damper. A coilable spring blade 10 is secured at one end 11 to the damper leaf 9 and has its other end secured to a spindle 12 mounted within a housing 13 for rotation. The spindle is connected to a torsion spring (not shown) which urges the spindle to rotate in such direction as to cause the blade 10 to be wound about the spindle within the housing.
The spring blade 10 constantly biases the damper to move from its-air-passing, retracted position shown in FIGS. 1 and 3 to an extended, air-blocking position shown in FIGS. 2 and 4. The damper could be gravity biased, if desired, but for assured operability the damper preferably is spring biased to its extended position.
The apparatus thus far described is conventional and forms no part of the invention apart from its cooperative relationship with the apparatus subsequently described herein.
The apparatus includes a collapsible strut 15 which, in one position, underlies and engages the lower leaf 9 of the damper and maintains the damper in its retracted position until such time as it is desired to enable the damper to move from its retracted position to its extended position. The strut comprises a plurality of separate components 16 and 17 which are aligned with one another, but spaced by a gap 18. The gap is spanned by a thermally sensitive, fusible linkage 20 having two links 21 and 22 which overlap one another. The link 21 is secured to the component 16 by a rivet 23 and the link 22 is secured to the component 17 by a rivet 24. Interposed between the overlapping ends of the links 21 and 22 is a known eutectic material (not shown) which, under normal ambient temperature conditions, is solid and secures the two links to one another. However, in response to an increase in ambient temperature to a predetermined level the eutectic material will liquefy and enable the two links 21 and 22 to separate from one another, thereby enabling the strut 15 to collapse. The construction and operation of the links 21 and 22 and the eutectic material are well known and conventional. Such links and material are commercially available from Globe Technologies Corporation, Standish, Mich.
Connecting means 25 is provided at each end of the strut 15 for removably connecting the strut to the frame via the housing 4 and in a position to underlie and support the damper. Each connecting means comprises a headed pin 26 secured to and projecting from a tab 27 extending from side walls 28 of the housing 4. Each of the strut-forming limbs 16 and 17 has a bayonet slot 29 for the accommodation of one of the pins 26. The strut 15 can be removed from both of the pins 26 so as to enable the strut to be replaced by another. However, if the strut is to be removed from only one of the pins, the other pin forms a pivot about the axis of which the strut may swing from its damper engaging and supporting position to a vertical position, as shown in FIGS. 2 and 4 in which the strut is disengaged from the damper. Disengagement of the strut from the damper enables the latter to move from its upper or retracted position to its extended position in which it blocks the flow of air past the damper.
The disconnection of one of the ends of the strut from one of the connecting pins 26 may be accomplished manually by a technician's simply raising one end of the strut slightly and pulling such end in a direction to enable the adjacent pin to pass through the bayonet slot. No bending or threading or other adjustment of any part of the strut connecting means is required.
To restore the damper to its retracted position the extended damper leaves may be moved manually upwardly and held in such position while the strut is rocked about the axis of the one pin 26 until the bayonet slot at the opposite end of the strut may be aligned and slipped over the other pin 26. Again, this operation may be performed manually without having to view the component parts of the assembly and without having to bend, thread, or otherwise adjust the parts of the assembly. The simplicity of the connection and disconnection of the supporting strut to the damper mounting frame is such that testing the operability of the damper is neither awkward nor burdensome.
The embodiment shown in FIGS. 6-8 corresponds to that described earlier with the exception that the damper engageable support strut 30 comprises two links 31 and 32 having corresponding ends which overlap one another. The overlapping portions of the strut have guide openings 33 through which bullet-nosed retainers 34 removably extend. The retainers maintain the link components in alignment until such time as the eutectic material (not shown) that is interposed between the overlapping portion of the links liquefies, whereupon the force applied on the strut by the overlying damper effects separation of the links.
The operation of the embodiment shown in FIGS. 6-8 corresponds to that illustrated in FIGS. 1-5.
The embodiment shown in FIGS. 9-12 corresponds to the previously described two embodiments except for the damper engaging strut 36. The strut 36 comprises a lever or support arm 37 having at one end a bayonet slot 38 which rockably accommodates a pin 39, thereby mounting the strut 36 for swinging movements about the axis of the pin 39. The lever 37 includes a right angular flange 40 which may underlie and engage the lower leaf 9 of the damper when the latter is in its retracted, air passing position. That end of the lever opposite the connecting bayonet slot and pin is separably secured by a eutectic substance (not shown) to a link 41 having aligning openings and projections 42 similar to those shown in FIGS. 1-5. The link also has adjacent its free end an opening 43 which accommodates a retaining stud or projection 44 which is fixed to a tab 45 forming part of the housing 4 and extends through a slot 46 formed in the lever 37. That end of the lever 37 opposite the connecting bayonet slot and pin therefore is supported on the frame via the housing 4 by the link 41 and the projection 44. The slot 46 in the lever 37 has an extension 47 in the flange 40. The extension is of such size as to enable the projection 44 to pass through the slot when necessary.
The operation of the embodiment shown in FIGS. 9-12 is very similar to that of previously described embodiment. However, there are some differences as will be explained.
To disconnect the lever arm 37 of the strut 36 from the connecting projection 44 when the strut supports the damper in its retracted position, that end of the lever opposite the bayonet slot and pin connection is moved manually in such direction as to enable the projection 44 to pass out of the opening 43 in the link 41, whereupon the strut may swing downwardly from the position shown in FIG. 10 to the position shown in FIG. 11, thereby disengaging the strut from the damper and enabling the latter to move to its extended, air blocking position.
When it is desired to restore the strut to its damper engaging position following testing of the apparatus, the damper manually may be returned to its retracted position and the strut returned manually to a position in which the projection 44 may enter the opening 43 and be retained therein.
The simplicity of the construction of the strut assembly is such as to make it possible to move the strut between its damper supporting and damper disengaged positions without having to view the parts, thereby avoiding the awkwardness and difficulty in disassembling and reassembling the component parts of the prior art constructions.
When the ambient temperature rises to a predetermined elevated level, the eutectic material which is interposed between and binds the link 41 to the lever 37 will liquefy. When the eutectic substance liquefies, the strut 36 is free to rock downwardly about the axis of the pin 39 from the position shown in FIG. 12 and such downward movement is unimpeded inasmuch as the projection 44 may pass freely through the slot extension 47. In this event the link 41 will remain suspended from the projection 44 whereas the lever 37 of the strut 36 will assume the position shown in FIG. 13 in which the lever is disengaged from the damper.
When it is desired to test the operability of the damper without liquefying the eutectic material, that end of the lever adjacent the projection 44 may simply be moved in a direction to withdraw the projection 44 from the opening 43, whereupon the strut may be swung to the damper disengaged position. The damper then is free to move to its extended, air blocking position.
FIG. 14 illustrates a modified frame construction wherein the only differences from that shown in FIG. 1 are that the frame illustrated in FIG. 14 has enlarged mounting tabs 27a on each of which a plurality of vertically spaced connecting pins 26a is mounted. This arrangement enables the level of the damper 5 in its retracted position to be varied.
This disclosure is representative of presently preferred embodiments of the invention, but is intended to be illustrative rather than definitive thereof. The invention is defined in the claims.
Patent Application
20080064322
