Balancing damper

Abstract

A ductless balancing damper is provided that is to be mounted in a duct. The balancing damper includes a blade and a mount. The mount includes a blade support portion and an attachment portion. The blade support portion of the mount rotatably supports the blade. The attachment portion is configured to frictionally engage an end of the duct to secure the balancing damper to the duct and support the blade in the duct.

Description

BALANCING DAMPER CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 696,262, filed September 18, 2024, which is incorporated herein by reference in its entirety. FIELD

[0002] This disclosure relates to heating, ventilation, and air conditioning (HVAC) systems and, in particular, to airflow control dampers for HVAC systems. BACKGROUND

[0003] HVAC systems often include balancing dampers to regulate the flow of air through a duct. The balancing damper includes one or more blades that can be rotated in the duct between open and closed positions. Rotating the blade toward the closed position increases the airflow restriction of the balancing damper through the duct. The balancing damper may be adjusted to reduce or eliminate pressure imbalances in a building caused by the HVAC system.

[0004] Many existing balancing dampers include a sleeve in which a blade is disposed and fastened. As one example, the sleeve may be an 8-inch-long sleeve having an oval cross- sectional shape. The sleeve forms a channel through which air is able to flow. For example, one end of the sleeve may mount to a neck of a plenum box and the other end of the sleeve may mount to a transport duct. Such balancing dampers including sleeves are bulky making them expensive to ship and store. Indeed, the sleeves are frequently assembled to a plenum box before shipping which significantly increases the package volume of the plenum box. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] FIG.1A is a front perspective view of a balancing damper mounted to a plenum box.

[0006] FIG.1B is a side perspective view of the balancing damper of FIG.1A mounted to the plenum box.

[0007] FIG.2 is a front perspective view of the balancing damper of FIG.1A.

[0008] FIG.3 is a rear perspective view of the balancing damper of FIG.1A.

[0009] FIG.4 is an exploded view of the balancing damper of FIG.1A.

[0010] FIG.5A is a front perspective exploded view of a first mounting assembly of the balancing damper of FIG.1A.

[0011] FIG.5B is a rear perspective exploded view of the first mounting assembly of the balancing damper of FIG.5A.

[0012] FIG.6A is a front perspective, exploded view of a second mounting assembly of the balancing damper of FIG.1A.

[0013] FIG.6B is a rear perspective, exploded view of the second mounting assembly of FIG.6A.

[0014] FIGS.7A and 7B are perspective views of an alternative clip for the mounting assemblies of FIGS.5A and 6A.

[0015] FIG.8. shows the balancing damper of FIG.1A separated from the plenum box.

[0016] FIGS.9A and 9B are perspective views showing the mounting assembly of FIG.6A connecting the balancing damper of FIG.1 to a neck of the plenum box.

[0017] FIG.10 is a perspective view of a blade of the balancing damper of FIG.1A having mounting shafts according to another embodiment. DETAILED DESCRIPTION

[0018] With respect to FIGS.1A-1B, a balancing damper 100 is shown attached to a plenum box 102 to form a plenum box assembly 103. The plenum box 102 has a box portion 104 and a duct connection portion such as a collar or neck 106 to which a transport duct is to be connected. The balancing damper 100 is ductless such that the balancing damper 100 is supported in the neck 106 and / or a transport duct connected to the neck 106. Because the balancing damper 100 does not have duct or housing as in conventional balancing dampers, the balancing damper 100 has a relatively small packing volume making it easier to store and transport. Moreover, when the balancing damper 100 is attached to the plenum box 102, the balancing damper 100 does not extend significantly outward from of the plenum box 102 and thus minimally increases the size of the package volume for storing and transporting the plenum box assembly 103 having the balancing damper 100.

[0019] The balancing damper 100 includes a blade 108, a first mount such as mounting assembly 110, and a second mount such as mounting assembly 112. The first mounting assembly 110 and second mounting assembly 112 attach to the neck 106 of the plenum box 102 and support the blade 108 in the airflow at the neck 106. The blade 108 is rotatably connected to the first mounting assembly 110 and second mounting assembly 112 to permit the blade 108 to be rotated in the neck 106. The blade 108 may be rotated to adjust the restriction of airflow through the neck 106.

[0020] With respect to FIGS.2-4, the balancing damper 100 is shown detached from the plenum box 102. The balancing damper 100 includes the blade 108, the first mounting assembly 110, the second mounting assembly 112, mounting shafts 114, 116, and a drive assembly 118.

[0021] The blade 108 includes a body 120 having a first surface 122 and an opposite second surface 124. The body 120 is sized to fit inside the neck 106 of the plenum box or inside a duct. The body 120 may have a size and shape that corresponds to the interior opening of the neck 106 or duct in which the blade 108 is placed. For example, where the balancing damper 100 is to be mounted in a duct having an oval shape, the blade 108 may have a size and shape corresponding to the size and shape of the interior of the duct. Thus, when the blade 108 is rotated to a closed configuration, for example, where the body 120 of the blade 108 is perpendicular to the airflow through the neck 106, the body 120 substantially closes the neck 106 to restrict airflow therethrough. The body 120 may include one or more cutouts 121 to provide clearance for rotation relative to the first and second mounting assemblies 110, 112. The body 120 may be generally flat and have a small thickness such that when the blade 108 is rotated to an open configuration (e.g., where the body 120 is parallel to the direction of airflow), the blade 108 has a small cross-sectional area in the direction of airflow to permit airflow through the neck 106 with minimal restriction from the blade 108.

[0022] The blade 108 includes a mount such as sleeve 126 by which the blade 108 is connected to the first mounting assembly 110 and second mounting assembly 112. The sleeve 126 forms a channel 128 in which the mounting shafts 114, 116 extend. The sleeve 126 includes a first bend portion 130, a second bend portion 132, and a third bend portion 134 that protrude outward from the first surface 122 of the body 120 and form a portion of the channel 128. The sleeve 126 further includes a fourth bend portion 136 and a fifth bendportion 138 that protrude outward from the second surface 124 and opposite the first bend portion 130, the second bend portion 132, and the third bend portion 134. The fourth bend portion 136 and fifth bend portion 138 form a portion of the channel 128 between the first bend portion 130, the second bend portion 132, and the third bend portion 134. In other words, the channel 128 is formed by the alternating configuration of the bend portions 130, 132, 134, 136, and 138. The mounting shaft 114 extends in the channel between the first bend portion 130, fourth bend portion 136, and second bend portion 132 which keep the mounting shaft 114 aligned with the channel 128. The mounting shaft 116 extends in the channel 128 between the third bend portion 134, the fifth bend portion 138, and second bend portion 132 which keeps the mounting shaft 116 aligned with the channel 128.

[0023] The blade 108 may be formed from a flat sheet of metal. For example, the outer profile of the blade 108 may be cut, for example, using a laser to form the body 120. Cuts may also be formed in the body 120 between the bend portions 130, 132, 134, 136, and 138. The body 120 may then be bent at these cuts in the body 120 to form the bend portions 130, 132, 134, 136, and 138, and thus the sleeve 126, in the body 120.

[0024] The bend portions 130, 132, 134, 136, and 138 may form a channel 128 having a non-circular cross-sectional shape that corresponds with a non-circular shape of the mounting shafts 114, 116. For example, in the embodiment shown, the channel 128 and the mounting shafts 114, 116 have a substantially square cross-section. With the mounting shafts 114, 116 having a non-circular cross-sectional shape (e.g., a square) that corresponds to the shape of the channel 128, the mounting shafts 114, 116 are not able to rotate in the channel 128 and thus secure the shafts 114, 116 from rotation relative to the body 120. In other words, the mounting shafts 114, 116 key into the channel 128 of the blade 108 such that the mounting shafts 114, 114 rotate with the blade 108 and vice versa.

[0025] In some forms, the mounting shafts 114, 116 may be fixed from rotation relative to the blade 108 with fasteners. For example, fasteners may extend through one of the bend portions 130, 132, 134, 136, 138 and into the mounting shafts 114, 116 to secure the shafts 114, 116 from rotation in the channel. In some forms, the mounting shafts 114, 116 may be welded to the mount of the blade 108 to fix the blade 108 from rotation relative to the shafts 114, 116.

[0026] While the balancing damper 100 has two mounting shafts 114, 116, in other forms, the balancing damper 100 may have a single mounting shaft that extends the lengthof the channel 128 from the first mounting assembly 110 to the second mounting assembly 112. Using two mounting shafts 114, 116, however, enables the same mounting assemblies 110, 112 and mounting shafts 114, 116 to be used with a variety of blades 108 of different sizes and shapes (e.g., that correspond to the size and shape of the duct in which the balancing damper 100 is to be mounted).

[0027] With respect to FIGS.5A-5B, exploded views of the first mounting assembly 110 are provided. The first mounting assembly 110 includes a mounting bracket 140, a bushing 142, and clips 144, 146.

[0028] The mounting bracket 140 includes a main body 148 having a blade support portion 150 and an attachment portion 152 connected by a bend 154. The attachment portion 152 is to connect to the end portion of the neck 106 of the plenum box 102. The blade support portion 150 extends further into the neck 106 to support the blade 108 in the neck 106. The blade support portion 150 has an opening 156 that supports the bushing 142. The opening 156 is sized such that the bushing 142 is able to rotate in the opening 156, for example, as the blade 108 and mounting shafts 114, 116 rotate.

[0029] The blade support portion 150 includes a first limit arm 158 and second limit arm 160 that extend inward toward the blade 108. The first limit arm 158 and second limit arm 160 extend into the path of rotation of the blade 108 and serve as stops to limit how far the blade 108 is able to rotate. For example, the first limit arm 158 serves as a stop when the blade 108 is fully rotated to the closed configuration (e.g., substantially perpendicular to a direction of airflow). The first limit arm 158 has a stop surface 162 that contacts the first surface 122 of the blade 108 to limit rotation of the blade 108 beyond the first limit arm 158. The second limit arm 160 serves as a stop when the blade 108 is fully rotated to the open configuration (e.g., substantially parallel to a direction of airflow). The second limit arm 160 has a stop surface 164 that contacts the first surface 122 of the blade 108 to limit rotation of the blade 108 beyond the second limit arm 160.

[0030] The bushing 142 has an insertion portion 166 and a flange portion 168. The flange portion 168 has a larger radial dimension (e.g., diameter) than the insertion portion 166. The insertion portion 166 is sized to be inserted into the opening 156 of the blade support portion 150 of the mounting bracket 140, whereas the flange portion 168 is sized such that it is not able to pass through the opening 156. In some forms, the bushing 142 includes a protrusion (e.g., a snap protrusion) that secures the bushing 142 to the mountingbracket 140 while permitting the bushing 142 to rotate in the opening 156. The bushing 142 includes an opening 170 that receives an end of the mounting shaft 114 to rotatably connect the mounting shaft 114 to the mounting bracket 140. The opening 170 may have a cross- sectional shape that corresponds to the cross-sectional shape of the mounting shaft 114. For example, the opening 170 may have a non-circular cross-sectional shape such that the bushing 142 is fixed from rotation relative to the mounting shaft 114.

[0031] The attachment portion 152 includes a central portion 172 and wings 174, 176 extending outward from the central portion 172. The wings 174, 176 are bendable relative to the central portion 172 to match the shape of the interior of the duct (e.g., neck 106) into which the mounting assembly 110 is inserted. For example, where the duct has an oval or circular shape, the wings 174, 176 may be bent inward to match the contour of the of the portion of the duct the mounting assembly 110 is positioned adjacent and to support the clips 144, 146 for attachment to the duct. The attachment portion 152 may be formed of a pliable material such a metal (e.g., steel). The attachment portion 152 may include a slit 178 at the interface of the wing 174 to the central portion 172 and a slit 180 at the interface of the wing 176 to the central portion 172 to make it easier to bend the wings 174, 176 relative to the central portion 172.

[0032] The clips 144, 146 connect the mounting bracket 140 to the duct. For example, the clips 144, 146 receive an end portion of the duct and frictionally engage the duct to resist the duct from being withdrawn from the clips 144, 146. In other words, one or more surfaces of the clip 144, 146 contact one or more surfaces of the duct to interact with the surfaces of the duct through friction. The friction from the contact of the clip 144, 146 with the duct resists movement of the clips 144, 146 along the surface of the duct. The structure of the clips 144, 146 may be identical such that the discussion of clip 144 applies to clip 146. The clip 144 has a first clip portion 182 that clips to one of the wings 174, 176 and a second clip portion 184 that clips to the first duct to which the balancing damper 100 is to be mounted. The second clip portion 184 does not extend outward of the duct significantly which permits a second duct to be slid over the second clip portion 184 when connecting a second duct to the first duct. A portion of the clip 144 is thus between the first duct and second duct when the first and second ducts are connected to one another, which may help retain the clip 144 on the first duct (e.g., by imparting an inward force on the clip 144 and increasing the frictional engagement of the clip 144 with the duct). The first clip portion 182 and second clip portion184 may include a mouth that imparts a clamping force an object inserted therein to retain the object therein. The clip 144 may be formed of an elastically deflectable material that deflects from a resting configuration when an object is inserted therein, but applies an inward clamping force on the object due to its tendency to return to the original, resting configuration. The inward clamping force of the clip 144 increases the frictional engagement of the clip 144 with the duct and wings 174, 176. The clip 144 may be an S-clip where the first clip portion 182 and second clip portion 184 attach in opposing directions. In some forms, the clip 144 is secured to the wing (e.g. with a fastener or by welding) but includes the second clip portion 184 to clip to the mounting bracket 140.

[0033] In some forms, one or more fasteners (e.g., screws) are extended through the duct and attachment portion 152 of the mounting bracket 140 to further secure mounting bracket 140 to the duct. The fastener(s) may be extended through clips 144, 146. In some forms, the wings 174, 176 of the attachment portion 152 are bent to frictionally engage the duct to secure the mounting bracket 140 to the duct. For example, the wings 174, 176 may be bent to extend along the interior surface of the duct and provide frictional resistance. In some forms, the clips 144, 146 may be omitted, with the wings 174, 176 holding the balancing damper 100 in the duct. A fastener may be extended through the attachment portion 152 and duct to further secure the mounting bracket 140 to the duct. In some forms, the wings 175, 176 are bent to extend along the exterior surface of a first duct and provide frictional resistance. A second duct may be slid over the end of the first duct and the wings 174, 176 to hold the wings 174, 176 in place.

[0034] With respect to FIGS.6A-6B, exploded views of the second mounting assembly 112 are provided. The second mounting assembly 112 includes a mounting bracket 190, a helical gear 192, and clips 194, 196.

[0035] The mounting bracket 190 has a blade support portion 198, an attachment portion 200, and a third portion 202 spacing the blade support portion 198 from the attachment portion 200. The blade support portion 198 of the mounting bracket 190 has an opening 204 to which the helical gear 192 attaches. The blade support portion 198 of the mounting bracket 190 also includes a gear support portion 206. The gear support portion 206 includes arms 208, 210 with mounting openings 212, 214 to support a worm gear 216 of the drive assembly 118 as discussed below.

[0036] The helical gear 192 has a body 220, a gear portion 222, and an attachment portion 224. The attachment portion 224 includes protrusions 224A (e.g., snap protrusions) sized to be inserted through the opening 204 of the blade support portion 198 of the mounting bracket 190 to secure the helical gear 192 to the mounting bracket 190 while permitting the helical gear 192 to rotate therein. The gear portion 222 of the helical gear 192 is supported about the body 220 by arms 226. The gear portion 222 is fixed to the body 220 such that the body 220 rotates with the gear portion 222. The gear portion has teeth 223 that engage the worm gear 216 to rotate gear portion 222 and the blade 108 as discussed below.

[0037] The body 220 defines an opening 228 to receive an end of the mounting shaft 116 and rotatably connect the mounting shaft 116 to the second mounting assembly 112. The opening 228 may have a cross-sectional shape that corresponds to the cross-sectional shape of the mounting shaft 116. For example, the opening 228 may have a non-circular cross- sectional shape such that the helical gear 192 is fixed from rotation relative to the mounting shaft 116.

[0038] The attachment portion 200 of the mounting bracket 190 has a central portion 230 and wings 232, 234 extending outward from the central portion 230. The wings 232, 234 are bendable relative to the central portion 230 to match the shape of the interior of the duct (e.g., neck 106) into which the mounting assembly 110 is inserted similar to the wings 174, 176 of the first mounting bracket 140. The attachment portion 200 of the mounting bracket 190 supports the clips 194, 196 to attach the second mounting assembly 112 to the duct (e.g., the neck 106 of the plenum box 102). The clips 194, 196 may be the same as the clips 144, 146 discussed above, having a first clip portion to clip to the wings 232, 234 and a second clip portion to clip to the duct. For instance, the clips 194, 196 secure the mounting bracket 190 to the duct by frictional engagement.

[0039] In some forms, one or more fasteners (e.g., screws) are extended through the duct and attachment portion 200 of the mounting bracket 190 to further secure mounting bracket 190 to the duct. The fastener(s) may be extended through clips 194, 196. In some forms, the wings 232, 234 of the attachment portion 200 are bent to frictionally engage the duct to secure the mounting bracket 190 to the duct. For example, the wings 232, 234 may be bent to extend along the interior surface of the duct and provide frictional resistance. In some forms, the clips 194, 196 may be omitted, with the wings 232, 234 holding the balancing damper 100 in the duct. A fastener may be extended through the attachment portion 200 andduct to further secure the mounting bracket 190 to the duct. In some forms, the wings 232, 234 are bent to extend along the exterior surface of a first duct and provide frictional resistance. A second duct may be slid over the end of the first duct and the wings 232, 234 to hold the wings 232, 234 in place.

[0040] The drive assembly 118 includes a drive shaft 236 and the worm gear 216 that engages the helical gear 192. The worm gear 216 includes threads 238 that mesh with the teeth 223 of the helical gear 192 such that rotation of the worm gear 216 rotates the helical gear 192. Due to the angle of the threads 238 of the worm gear 216 relative to the teeth 223 of the helical gear 192, the helical gear 192 is not able to rotate the worm gear 216. The worm gear 216 thus locks the helical gear 192 from rotation and holds the orientation of the blade 108 in the duct even when force is applied to the blade 108 (e.g., caused by airflow) to rotate the blade 108 about the mounting shafts 114, 116. Thus, the worm gear 216 is used to set the orientation of the blade 108 and hold the blade 108 at the set orientation.

[0041] The drive assembly 118 may be mounted to the gear support portion 206. For example, the drive shaft 236 extends into the mounting openings 212, 214 of the arms 208, 210 to support the worm gear 216 of the drive assembly 118 and permit the drive shaft 236 to rotate in the mounting openings 212, 214. The drive shaft 236 may be press fit into the opening 216A of the worm gear 216 to secure the drive shaft 236 to the worm gear 216. For example, the worm gear 216 may be positioned in between the arms 208, 210 of the gear support portion 206 and the drive shaft 236 extended through the mounting opening 212, through the opening 216A of the worm gear 216, and into the mounting opening 214. The arms 208, 210 limit axial movement of the worm gear 216 and drive shaft 236 in the gear support portion 206 which keeps the drive shaft 236 in the openings 212, 214 of the arms 208. With the drive shaft 236 in the openings 212, 214 of the arms 208, the drive shaft 236 is not able to move substantially in a radial direction. The openings 212, 214 of the arms 208, 210 are sized to permit the drive shaft 236 to rotate therein. In another form, a pin or clip may be extended through an end of the drive shaft 236 passed through the mounting opening 214 to inhibit the drive shaft 236 from being withdrawn from the mounting opening 214.

[0042] The drive shaft 236 includes a body 240 having ribs 242 extending axially along the body 240. The drive shaft 236 is received in an opening 216A of the worm gear 216. The ribs 242 of the drive shaft 236 engage the worm gear 216 (e.g., frictionally engage) to fix the drive shaft 236 from rotation relative to the worm gear 216. The drive shaft 236 includes adrive opening 244 sized to receive a drive head operable to turn the drive shaft 236, for example a drive head 262 mounted to a rotary cable 260 (see FIG.4) that extends to a point of the HVAC system accessible by a user (e.g., a vent into a room such as a linear diffuser). A user may rotate the drive shaft 236 (e.g., using the drive cable) to rotate the worm gear 216 and cause the helical gear 192 and blade 108 rotationally coupled thereto to rotate in the duct. The blade 108 may be rotated between a fully closed position where the blade 108 contacts the first stop surface 162 and a fully open position where the blade 108 contacts the second stop surface 164.

[0043] The rotary cable 260 (see FIG.4) includes the drive head 262 and a flexible cable 264 coupled to the drive head 262. The drive head 262 may be an end portion of the flexible cable 264 shaped to rotatably engage the drive opening 244 (e.g., a square shape). The drive head 262 may be inserted into the drive opening 244 of the drive shaft 236 to rotate the drive shaft 236. The drive head 262 may be secured in the drive opening 244 by a set screw 266 that threads into an opening 268 in a sidewall of the drive shaft 236 forming the drive opening 244. The flexible cable 264 may be routed in the plenum or duct to a point of the HVAC system accessible by a user. The user may rotate the flexible cable 264 (e.g., an end of the flexible cable 264 accessible to the user), which causes the drive head 262 to rotate and turn the drive shaft 236, which adjusts the orientation of the blade 108 as discussed above.

[0044] In some forms, the balancing damper 100 forms part of a balancing damper assembly including a motor. The motor includes a motor shaft operably coupled to the drive shaft 236 of the drive assembly 118 of the balancing damper 100. For example, an end portion of the motor shaft may be inserted into the drive opening 244 to rotatably engage the drive opening 244 to rotate the drive shaft 236. As another example, the motor shaft may be connected to one end of the rotary cable, with the opposite end of the rotary cable coupled to the drive opening 244 of the drive shaft 236. The motor is operable to rotate the blade 108 of the balancing damper 100 to adjust the orientation of the blade 108 in the duct. The motor may be remotely controlled, for example, by a remote computer such as a master controller of an HVAC system.

[0045] The first mounting assembly 110 and second mounting assembly 112 support the mounting shafts 114, 116 and the blade 108 inside the neck 106. For instance, the blades 108 and mounting shafts 114, 116 rotate about an axis 246 (see FIG.3) that extends through the neck 106 of the plenum box 102 when the balancing damper 100 is mounted to the neck106. This axis of rotation may also extend through a transport duct attached to the neck 106. The neck 106 thus serves as the duct or housing about the blade 108 such that the balancing damper 100 itself is ductless.

[0046] The first mounting assembly 110 and second mounting assembly 112 also support the mounting shafts 114, 116 within the neck 106 such that the mounting shafts 114, 116 do not extend through the neck 106 or transport duct. The mounting shafts 114, 116 are supported inward of the outermost extent of the mounting assemblies 110, 112. For instance, the blade support portion 150 of the first mounting assembly 110 supports the mounting shaft 114 inward of the attachment portion 152 of the first mounting assembly 110 and the blade support portion 198 of the second mounting assembly 112 supports the mounting shaft 116 inward of the attachment portion 200 of the second mounting assembly 112. In other words, the first mounting assembly 110 and second mounting assembly 112 support the mounting shafts 114, 116 entirely inward of the neck 106 and do not extend outward beyond the neck 106. The neck 106, which forms the duct about the balancing damper 100, thus does not include any holes or openings to support the mounting shafts 114, 116 for rotation therein.

[0047] The balancing damper 100 is ductless, being configured to clip to the end of a duct such as the neck 106. Being ductless, the balancing damper 100 is significantly smaller than conventional ducted balancing dampers which reduces the costs associated with storing and shipping the balancing dampers. Additionally, when assembled to a plenum box 102, the balancing damper 100 does not increase the size of the plenum box assembly 103 because the balancing damper 100 supports the blade 108 in the neck 106 and similarly reduces the costs associated with storing and shipping plenum box assemblies.

[0048] With respect to FIGS.7A-7B, a clip 250 is provided that is similar to the clips 144, 146, 194, and 196. The clip 250 may be used as an alternative to the clips 144, 146, 194, and 196. The clip 250 is similar in many respects to the clips discussed above with a difference being that the second clip portion 252 of the clip 250 includes a flat outer surface 254. With the flat outer surface 254, the clip 250 does not protrude as far outward of the duct to which the second clip portion 252 is clipped (e.g., the neck 106 of the plenum box 102). Instead, the second clip portion 252 lays flat against the first duct to permit a second duct (e.g., transport duct) to be slid over the clip 250 and form a tight connection with the first duct.

[0049] With respect to FIG.8, a method of attaching the balancing damper 100 to a duct, such as the neck 106 of a plenum box 102 is provided. A blade 108 may be selected that has a shape and size corresponding to the shape and size of the neck 106. The mounting shafts 114, 116 may be extended into the sleeve 126 of the blade 108 to connect the blade 108 to the first and second mounting assemblies 110, 112.

[0050] The wings 174, 176 of the first mounting assembly 110 may be bent from the central portion 172 of the attachment portion 152 to fit inside the opening of the neck 106. For example, the wings 174, 176 may be bent inward to conform to the shape of the opening of the neck 106. The wings 232, 234 of the second mounting assembly 112 may also be bent from the central portion 230 of the attachment portion 200 to fit inside the openings. The wings 232, 234 may be bent inward to conform to the shape of the opening of the neck 106.

[0051] The first mounting assembly 110 and second mounting assembly 112 are aligned with the opening of the neck 106 of the plenum box 102. For example, the wings 174, 176 of the first mounting assembly 110 and the wings 232, 234 of the second mounting assembly 112 are positioned to be inserted into the opening of the neck 106. The second clip portions 182 of the clips 144, 146 of the first mounting assembly 110 are aligned with the neck 106 and positioned to receive the end portion of the neck 106 therein. Likewise, the second clip portions 182 of the clips 194, 196 of the second mounting assembly 112 are aligned with the neck 106 and positioned to receive the end portion of the neck 106 therein. The balancing damper 100 is then urged axially along the neck 106 in direction 256 to urge the end portion of the neck 106 into the clips 144, 146, 194, 196 and the wings 174, 176, 232, 234 into the neck 106.

[0052] In FIGS.9A-9B, the balancing damper 100 is shown attached to the plenum box 102 with the clips 144, 146, 194, 196 replaced with clips 250 that have a flat outer portion. As shown, the clips 250 of the second mounting assembly 112 receive the end portion of the neck 106 therein and the wings 232, 234 extend along the interior surface of the neck 106. The clips 250 of the first mounting assembly 110 may similarly receive the end portion of the neck 106, with the wings 174, 176 similarly extending along the interior surface of the neck 106. The balancing damper 100 is supported in the neck 106. A transport duct can be slid over the neck 106 and clips 250 of the balancing damper 100 to attach the transport duct to the plenum box 102. As the clips 250 do not protrude significantly outward from the neck, the transport duct is able to form a tight connection with the neck 106. The transport ductmay thus form a tight seal about the connection with the neck 106 of the plenum box 102 to inhibit air from leaking at the connection. Moreover, as the balancing damper 100 supports the mounting shafts 114, 116 and blade 108 entirely inside the neck 106, no openings or holes are formed in the neck 106 to permit the blade 108 to rotate, which aids to inhibit air from leaking at the connection between the neck 106 and the transport duct. In other words, the balancing damper 100 does not interfere with the connection of the transport duct to the neck 106 of the plenum box 102.

[0053] The user may operate the drive assembly 118 to adjust the orientation of the blade 108 at the neck 106 of the plenum box 102. The user may turn the drive shaft 236 (e.g., with the drive cable) to adjust the orientation of the blade 108 in the duct. For example, the drive shaft 236 may be rotated to set the blade 108 a position between the open configuration and the closed configuration to adjust the airflow restriction of the balancing damper 100 in the duct.

[0054] With respect to FIG.10, the blade 108 of the balancing damper 100 is shown with mounting shafts 270, 272 according to another embodiment. The mounting shafts 270, 272 are similar to the mounting shafts 114, 116 discussed above with the difference being that the inward ends 274, 276 of the mounting shafts 270, 272 are tapered. The tapered ends 274, 276 make it easier to insert the mountings shafts 270, 272 into the sleeve 126 of the blade 108. Specifically, the tapered ends 274, 276 have a smaller cross-sectional dimension than the remainder of the mounting shafts 270, 272 which makes it easier to insert into the channel 128 of the sleeve 126. The tapered ends 274, 276 may contact the bend portions 132, 136, 138 as the mounting shafts 270, 272 are extended along the sleeve 126, with the tapered surfaces aiding to align the mounting shafts 270, 272 with the channel 128 of the sleeve.

[0055] Uses of singular terms such as “a,” “an,” are intended to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open- ended terms. It is intended that the phrase “at least one of” as used herein be interpreted in the disjunctive sense. For example, the phrase “at least one of A and B” is intended to encompass A, B, or both A and B.

[0056] While there have been illustrated and described particular embodiments of the present invention, those skilled in the art will recognize that a wide variety of modifications, alterations, and combinations can be made with respect to the above-describedembodiments without departing from the scope of the invention, and that such modifications, alterations, and combinations are to be viewed as being within the ambit of the inventive concept.

Claims

CLAIMS What is claimed is:

1. A ductless balancing damper to be mounted in a duct, the balancing damper comprising: a blade; and a mount including a blade support portion and an attachment portion, the blade support portion rotatably supporting the blade and the attachment portion configured to frictionally engage an end of the duct to secure the balancing damper to the duct and support the blade in the duct.

2. The balancing damper of claim 1 wherein the attachment portion of the mount includes one or more clips that receive an end portion of the duct therein, the one or more clips frictionally engaging the duct to secure the end portion of the duct in the one or more clips.

3. The balancing damper of claim 2 wherein the attachment portion of the mount includes a mounting bracket having an arm supporting at least one clip of the one or more clips, wherein the at least one clip is an S-clip having a first portion clipped to the arm and a second portion to clip to the duct.

4. The balancing damper of claim 1 wherein the blade support portion extends from the attachment portion to support the blade inside the duct.

5. The balancing damper of claim 1 wherein the balancing damper does not include a housing about the blade.

6. The balancing damper of claim 1 further comprising at least one shaft connected to the blade support portion of the mount, wherein the blade includes a sleeve formed in the blade and having a channel receiving the at least one shaft.

7. The balancing damper of claim 6 wherein the at least one shaft includes a first shaft and a second shaft.

8. The balancing damper of claim 6 wherein the blade includes a first surface and an opposite second surface, the sleeve formed of a first bend portion extending outward from the first surface of the blade and a second bend portion extending outward from the second surface of the blade.

9. The balancing damper of claim 6 wherein the at least one shaft has a non- circular cross-section corresponding to a non-circular cross-section of the channel of the sleeve.

10. The balancing damper of claim 1 wherein the mount includes a mounting bracket having one or more wings, the attachment portion including the one or more wings of the mounting bracket, the one or more wings being pliable to conform the one or more wings to a shape of the duct to which the mount is secured.

11. The balancing damper of claim 1 further comprising at least one shaft connected to the blade and the blade support portion of the mount, wherein the at least one shaft is inward of the attachment portion of the mount.

12. The balancing damper of claim 1 wherein the blade support portion of the mount includes a bushing, the bushing connected to the blade to permit rotation of the blade relative to the attachment portion of the mount.

13. The balancing damper of claim 1 further comprising a drive assembly connected to the mount, the drive assembly operable to rotate the blade relative to the attachment portion of the mount.

14. The balancing damper of claim 13 wherein the drive assembly includes a helical gear rotatably fixed to the blade and a worm gear engaging the helical gear such that rotation of the worm gear adjusts an orientation of the blade relative to the attachment portion of the mount.

15. The balancing damper of claim 14 wherein the mount includes a mounting bracket having a gear support portion to support the worm gear.

16. The balancing damper of claim 1 wherein the mount includes a mounting bracket having a first stop to limit rotational movement of the blade in a first direction and a second stop to limit rotational movement of the blade in a second direction opposite the first direction.

17. The balancing damper of claim 1 wherein the mount includes a first mounting bracket and a second mounting bracket, the blade extending between the first mounting bracket and the second mounting bracket.

18. A plenum box assembly comprising: a plenum box having a box portion and a duct connection portion to be connected to a transport duct; and an adjustment damper having a first mount, a second mount, and a blade supported between the first mount and second mount, the first mount and second mount frictionally engaging the duct connection portion of the plenum box to secure the adjustment damper to the plenum box and support the blade at the duct connection portion of the plenum box.

19. The plenum box assembly of claim 18 wherein the first mount and second mount of the adjustment damper each include one or more clips receiving an end portion of the duct connection portion therein, the one or more clips frictionally engaging the duct connection portion and thereby securing the adjustment damper to the plenum box.

20. The plenum box assembly of claim 19 wherein the first mount and second mount each include a mounting bracket having an attachment arm supporting the clip, wherein the clip is an S-clip having a first portion clipped to the attachment arm and a second portion clipped to the duct connection portion of the plenum box.

21. The plenum box assembly of claim 18 wherein the blade is rotatable about an axis, the axis extending through one or more of the duct connection portion of the plenum box and a transport duct to be connected to the duct connection portion of the plenum box.

22. The plenum box assembly of claim 18 wherein the first mount and second mount support the blade inside the duct connection portion.

23. The plenum box assembly of claim 18 wherein the first mount and second mount of the adjustment damper include one or more attachment wings received in the duct connection portion of the plenum box, the one or more attachment wings extending along a wall of the duct connection portion.

24. The plenum box assembly of claim 18 wherein the adjustment damper includes at least one shaft connecting the blade to the first mount and the second mount, wherein the at least one shaft is inward of outermost portions of the first mount and second mount.

25. The plenum box assembly of claim 18 wherein the adjustment damper includes at least one shaft rotatably connected to the first mount and second mount, wherein the blade includes a sleeve formed in the blade receiving the at least one shaft.

26. The plenum box assembly of claim 25 wherein the at least one shaft has a non-circular cross-section, wherein the sleeve includes a channel having a non-circular cross-section corresponding to the non-circular cross-section of the at least one shaft.

27. The plenum box assembly of claim 18 wherein the first mount and second mount include a bushing rotatably supporting the blade to permit rotation of the blade relative to plenum box.

28. The plenum box assembly of claim 18 wherein the adjustment damper further comprises a drive assembly connected to at least one of the first mount and second mount, the drive assembly operable to rotate the blade relative to the plenum box.

29. The plenum box assembly of claim 28 wherein the drive assembly includes a helical gear rotatably fixed to the blade and a worm gear engaging the helical gear such that rotation of the worm gear adjusts an orientation of the blade relative to the plenum box.

30. The plenum box assembly of claim 18 wherein at least one of the first mount and second mount includes a first stop to limit rotational movement of the blade in a first direction and a second stop to limit rotational movement of the blade in a second direction opposite the first direction.

31. A method of installing a balancing damper, the method comprising: aligning an attachment portion of the balancing damper with an end portion of a duct extending along an axis; and urging the attachment portion of the balancing damper along the axis to clip the attachment portion of the balancing damper to the duct.

32. The method of claim 31 further comprising bending one or more wings of the attachment portion of the balancing damper to conform the attachment portion to a shape of the end portion of the duct.

33. The method of claim 31 further comprising operating a drive assembly to change an orientation of a blade of the balancing damper relative to the duct.

34. The method of claim 33 wherein the drive assembly includes a helical gear rotatably fixed to the blade and a worm gear engaging the helical gear, wherein operating the drive assembly includes rotating the worm gear to turn the helical gear and change the orientation of the blade.

35. The method of claim 31 further comprising assembling the balancing damper by inserting a shaft into a sleeve of a blade sized to be inserted into the end portion of the duct and rotatably coupling the shaft to the attachment portion of the balancing damper.

36. The method of claim 31 wherein the attachment portion of the balancing damper includes clips that receive the end portion of the duct therein.

37. A ductless balancing damper to be mounted in a duct, the balancing damper comprising: a blade; and a mount including a blade support portion and an attachment portion, the blade support portion rotatably supporting the blade and the attachment portion including at least one attachment flange that is adjustable to conform the attachment portion to a shape of the duct to secure the balancing damper to an end of the duct and support the blade in the duct.

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