TECHNICAL FIELD

[OOO1] This invention is related to laundry drying machine burners and burner assemblies.

BACKGROUND

[0002] Typical laundry dryers are constructed to maximize the laundry load capacity by making the rotating dryer drum as large as possible. The size of the drum is limited by the size of the dryer cabinet, and the size of the cabinet is typically dictated by factors related to commercial expectations, such as the need to fit the dryer into a typical household laundry room or the like. The drive to increase drum size, while not exceeding the desired cabinet size, leads to a reduction in useable free space for internal components that surround the drum, such as the gas burner assembly. [0003] It has been found that it is difficult to accommodate dryer burners without adapting the burner to the particular internal layout of the dryer. Any significant deviation among products can lead to the need for a customized burner assembly to fit the particular drum and cabinet configuration. For example, a freestanding dryer can have a significantly different internal space than a so-called laundry center having a dryer mounted above a washer. Similarly, a combined washer/dryer that uses a single drum to perform washing and drying, can have a significantly different internal layout than a freestanding dryer or a laundry center.

[0004] Previous efforts to provide burner assemblies for different types of dryer have led to excess costs to make unique designs for each internal layout. Thus, the inventor has determined that the state of the art of dryer burners can still be advanced. [0005] This description of the background is provided to assist with an understanding of the following explanations of exemplary embodiments, and is not an admission that any or all of this background information is necessarily prior art. SUMMARY

[0006] In a first aspect, there is provided A laundry dryer burner assembly having: a burner chamber extending along a longitudinal direction; a burner located within the burner chamber and extending along the longitudinal direction, the burner being rotationally fixed relative to the burner chamber; and a rotatable assembly connected to the burner and selectively movable about the longitudinal direction between a first position and a second position, the rotatable assembly comprising a mixing tube having a mixing tube outlet rotatably connected to the burner and a mixing tube inlet that is offset in a radial direction that is perpendicular to the longitudinal direction from the mixing tube outlet.

[0007] In some examples, the mixing tube inlet is located, relative to the radial direction, outside an outer perimeter of the burner chamber.

[0008] In some examples, the rotatable assembly further comprises a venturi, the venturi having a venturi outlet connected to the mixing tube inlet, a venturi tube gas inlet, and one or more venturi tube air inlets.

[0009] In some examples, the rotatable assembly further comprises a gas valve connected to the venturi tube gas inlet.

[0010] In some examples, the mixing tube is bent 180° between the mixing tube inlet and the mixing tube outlet, and at least one of the venturi and the gas valve is at least partially located adjacent an outer wall of the burner chamber, and between an inlet end and an outlet end of the burner chamber with respect to the longitudinal direction.

[0011] In some examples, the mixing tube is bent 180° between the mixing tube inlet and the mixing tube outlet.

[0012] In some examples, the first position is at least 90° about the longitudinal direction from the second position.

[0013] In some examples, the burner comprises a plurality of first flame ports extending along the longitudinal direction on a first lateral side of the burner, and a plurality of second flame ports extending along the longitudinal direction on a second lateral side of the burner, with the first plurality of flame ports and the second plurality of flame ports being at an equal vertical height when the burner is installed in a laundry dryer.

[0014] In some examples, the rotatable assembly further comprising an igniter positioned adjacent the burner.

[0015] In some examples, the burner comprises one or more first flame ports at a first angular position relative to the longitudinal direction, and one or more second flame ports at a second angular position relative to the longitudinal direction, and the igniter is positioned adjacent at least one of the one or more first flame ports when the rotatable assembly is in the first position, and adjacent at least one of the one or more second flame ports when the rotatable assembly is in the second position.

[0016] In some examples, the rotatable assembly further comprises a flame sensor that is positioned adjacent at least one of the one or more first flame ports when the rotatable assembly is in the first position, and adjacent at least one of the one or more second flame ports when the rotatable assembly is in the second position [0017] In some examples, a connector joins the burner to the burner chamber. [0018] In some examples, the connector is rigidly connected to one of the burner and the burner chamber, and slidingly engaged along the longitudinal direction with the other of the burner and the burner chamber.

[0019] In some examples, the connector extends radially between a longitudinal end of the burner opposite the mixing tube and an inner wall of the burner chamber.

[0020] In some examples, one of the mixing tube outlet and the burner comprises a radial flange, and the other of the mixing tube outlet and the burner comprises a radial groove, the radial flange being captured in the radial groove to allow relative rotation between the burner and the mixing tube outlet about the longitudinal direction.

[0021] In another exemplary aspect, there is provided a method for installing a laundry dryer burner assembly, the method comprising: providing a dryer cabinet assembly with a burner chamber in a fixed position within the cabinet assembly; providing a laundry dryer burner assembly having a burner and a rotatable assembly comprising a mixing tube rotatably connected to the burner; rotating the burner relative to the rotatable assembly to orient the burner with a first row of flame ports on a first lateral side of the burner at an equal vertical height with a second row of flame ports on a second lateral side of the burner; inserting the burner into the burner chamber; rotationally fixing the burner to the burner chamber; and connecting the rotatable assembly to a gas supply line.

[0022] In some examples, the step of rotating the burner relative to the rotatable assembly is performed before the step of inserting the burner into the burner chamber.

[0023] In some examples, the step of rotating the burner relative to the rotatable assembly is performed after the step of rotationally fixing the burner to the burner chamber.

[0024] In some examples, the method includes rotationally fixing the rotatable assembly relative to the burner after the step of rotating the burner relative to the rotatable assembly.

[0025] In some examples, rotationally fixing the rotatable assembly comprises securing the rotatable assembly to the gas supply line.

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Embodiments of inventions will now be described, strictly by way of example, with reference to the accompanying drawings, in which:

[0027] Figure 1 is a schematic side elevation view of a first exemplary burner assembly. [0028] Figure 2 is a schematic side elevation view of a second exemplary rotatable assembly.

[0029] Figures 3A and 3B illustrate the burner assembly of Figure 1 in two different installations.

[0030] Figure 4 illustrates another exemplary burner assembly without the burner chamber.

[0031] Figure 5 illustrates an exemplary connector for joining a burner to the wall of a burner chamber.

[0032] Figure 6 shows a cutaway view of the connector of Figure 5.

[0033] Figure 7 illustrates an exemplary mixing tube and rotatable connector.

[0034] Figure 8A and 8B show the burner assembly of Figure 4 in two different orientations relative to the burner chamber and burner.

[0035] In the drawings, like numbers refer to like elements.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

[0036] The inventor has determined that requirements to provide gas burners to multiple different dryer product configurations can be satisfied by providing a gas burner assembly having a burner and burner chamber that are fixed in the same orientation in all dryer configurations, and a rotatable assembly that can be reoriented to accommodate differences in the surrounding cabinet layout. While embodiments are expected to have particular utility for using a single burner assembly in multiple different products, embodiments also provide flexibility to accommodate individual product lines, and provide advantages in the product assembly process. Thus, there is no need to use embodiments in conjunction with multiple different dryer products.

[0037] Figure 1 schematically illustrates an exemplary embodiment of a laundry dryer burner assembly 100. The burner assembly 100 has a burner chamber 102 and a burner 104 located within the burner chamber 102. The burner chamber 102 and burner 104 extend along a longitudinal direction L from a chamber inlet 106 to a chamber outlet 108.

[0038] The burner chamber 102 is defined by one or more walls, which may have a circular cross-section or other cross-sectional shapes as viewed along the longitudinal direction L. As shown in the subsequent embodiments, the wall may have various openings to allow airflow or for other reasons. The chamber 102 may conveniently be formed by sheet metal, such as a rolled steel sheet that is bonded or crimped to form a closed seam, such as known in the art.

[0039] The burner 104 is positioned within the burner chamber 102 and configured to generate a flame pattern that is configured to heat air passing from the chamber inlet 106 to the chamber outlet 108. A variety of different burners 104, and associated flame patterns, are known in the art. In the shown example, the burner 104 comprises a tubular burner having a first row of flame ports 110 extending along the longitudinal direction L on a first lateral side of the burner 104, and a second row of flame ports 110 extending along the longitudinal direction L the opposite lateral side of the burner 104. The term "lateral side" refers to sides in a horizontal plane when the burner 104 is installed for use. When so installed, the burner 104 is oriented with the first row of flame ports 110 at the same vertical height as the second row of flame ports 110, preferably with mirror symmetry with respect to a plane defined by the longitudinal direction L and the global (gravitational) vertical direction V.

[0040] The burner 104 may be positioned at any suitable location with respect to the burner chamber 102. In the shown example, the burner 104 is located entirely within the confines of the burner chamber 102, and at a location below a vertical center of the burner chamber 102. This configuration is expected to provide a relatively large space within the burner chamber 102 above the burner 104, where heat can be exchanged between the burner flames and the passing air. Other configurations may be used in other embodiments.

[0041] When fully installed, the burner 104 may be rotationally fixed relative to the burner chamber 102. Rotational fixation between the burner 104 and the burner chamber 102 is desirable when the burner 104 is configured to operate in a particular orientation with respect to the vertical direction V. For example, in the shown embodiment, the burner 104 is intended to operate with the two rows of flame ports 110 facing in opposite lateral directions to evenly heat the air passing through the burner chamber 102. Rotational fixation may be provided by one or more connectors 112 that extend from the burner 104 to the wall of the burner chamber 102. The connectors 112 may have permanent attachments, such as rivets, welds, or crimped joints. The connectors 112 alternatively may be detachable, such as discussed in more detail herein. The connectors 112 hold the burner 104 relative to the burner chamber 102 to prevent relative rotation between them about the longitudinal direction L, which prevents the burner 104 from being improperly installed or positioned relative to the burner chamber 102, and ensures proper orientation of the flame ports 110.

[0042] While it is preferred for there to be a connector 112 joining the burner 104 to the burner chamber 102, in some cases the connector 112 may be omitted while still providing relative rotational fixation. For example, the burner 104 may be connected to the rotatable assembly 114 discussed below by a collar that rotationally fixes the rotatable assembly 114 to the burner 104 once the burner 104 and rotatable assembly 114 are moved to their desired final relative angular positions, or a rotation lock may be installed to secure the positions of the parts. [0043] The burner assembly 100 also includes a rotatable assembly 114 having a mixing tube 116. The mixing tube outlet 118 is connected to the burner 104 by a joint that allows the mixing tube 116 (and the remainder of the rotatably assembly 114) to rotate relative to the burner 104 about the longitudinal direction L. The mixing tube 116 extends from a mixing tube inlet 120 to the mixing tube outlet 118. The mixing tube inlet 120 is offset in a radial direction R from the mixing tube outlet 118. The radial direction R is any direction that is perpendicular to the longitudinal direction L. In Figure 1, the radial direction is illustrated by an arrow pointing down along the vertical direction V, but the radial direction may be oriented laterally or at any other angle.

[0044] The mixing tube inlet 120 may be positioned outside an outer perimeter of the burner chamber 102, such as shown, but this is not strictly required. For example, the mixing tube inlet could be positioned at the location identified by line 122. The mixing tube inlet 120 may be located, with respect to the longitudinal direction L, between the chamber inlet 106 and the chamber outlet 108, such as shown. Alternatively, the mixing tube inlet 120 may be located outside the longitudinal extend of the burner chamber 102, such as shown at the alternative location identified by line 122.

[0045] The mixing tube 116 is a rigid conduit having a closed passage forming a fluid communication path from the mixing tube inlet 120 to the mixing tube outlet 116. Gas and air are blended within the mixing tube 116 and conveyed to the burner 104 at the mixing tube outlet 116. The mixing tube inlet 120 may be connected to one or more flexible conduits that provides the gas and air, but more preferably it is connected to a venturi 124.

[0046] The venturi 124 comprises a rigid passage having a gas inlet 126 and one or more air inlets 128. The air inlets 128 and gas inlet 126 are upstream of a constriction, which causes incoming pressurized gas to accelerate and reduce pressure and thereby entrain air into the gas stream. Venturis are well known in the art and need not be described in more detail herein.

[0047] The venturi 124 may be connected at its upstream end to a flexible conduit that provides a flow Office Action gas, but more preferably a gas valve 130 is rigidly attached to the venturi 124. In this case, the gas valve 130 is also part of the rotating assembly 114. Gas valves are known in the art and need not be described in more detail herein. The gas valve 130 is connected to a flexible conduit 132 that provides gas to the rotatable assembly 114.

[0048] The burner assembly 110 also may include other features, such as an igniter 134 (e.g., a resistance heated coil or spark generator, as known in the art) and a flame sensor 136 (e.g., a conductive rod though which a current indicating the presence of a flame is detected, or the like as known in the art). In the embodiment of Figure, the igniter 134 and flame sensor 136 are mounted to the wall of the burner chamber 102, but one or both may be mounted directly to the burner 102. Other locations for the igniter 134 and flame sensor 136 are discussed below.

[0049] The rotatable assembly 114 of the embodiment of Figure 1 is configured with the mixing tube 116 being bent such that the mixing tube inlet 120 faces 180° relative to the mixing tube outlet 118. The mixing tube 116 is also dimensioned such that the venturi 124 and gas valve 130 are located outside and adjacent to the burner chamber 102. This provides a compact arrangement of parts relative to both the radial direction R and the longitudinal direction L.

[0050] While the configuration of Figure 1 is expected to be particularly useful, it is not strictly required. For example, the rotatable assembly 114 may be configured with the mixing tube inlet 120 oriented at 90° to the mixing tube outlet 118, and with the venturi 124 or other parts extending along the radial direction R, such as shown in Figure 2. Other alternatives and variations will be apparent to persons of ordinary skill in the art in view of the present disclosure.

[0051] Figures 3A and 3B illustrate two different laundry drying machines with the burner assembly 100 two different orientations. Figure 3A shows the drum 300 and cabinet 302 of a typical standalone laundry dryer. The cabinet 302 encloses various parts, such as a blower 304 for directing the drying air through the burner assembly 100 and drum 300. Here, the burner assembly 100 is configured with the rotatable assembly 114 pointing downward relative to the burner chamber 102 to fit within the allowed space.

[0052] In Figure 3A, the drying machine is a laundry center type machine, and the cabinet 302 is relatively narrow, leaving insufficient room to install the burner assembly 100 in the configuration shown in Figure 3A. Thus, the rotatable assembly 114 is repositioned by rotating it about the longitudinal axis to be offset radially to the right, such that the burner assembly 100 fits within the allowed space.

[0053] The angular range of motion 0 of the rotatable assembly 114 relative to the burner chamber 102 and burner tube 104 may be selected according to any criteria. Preferably, the angular range of motion 0 is selected to allow installation of the burner assembly 100 into at least two different drying machines having different configurations of internal parts. Alternatively, or in addition, the angular range of motion 0 may be selected to allow the rotatable assembly 114 to be moved into position where it can be installed in the burner chamber 102. For example, the rotatable assembly 114 may be placed in one orientation to slide the burner 104 into the burner chamber 102, and then rotated to fit the rotatable assembly 114 into the desired location within the cabinet 302. In various embodiments, the angular range of motion 0 may be at least 45°, at least 90°, or at least 120°. Other alternatives and variations will be apparent to persons of ordinary skill in the art in view of the present disclosure.

[0054] Figures 4 through 8B illustrate another exemplary embodiment of a burner assembly 100. In this case, the burner assembly comprises a burner housing 102, a burner 104, and a rotatable assembly 114, generally as described previously herein, so differences will be highlighted in the following description. As before, the burner 104 includes two lateral rows of flame ports 110, and also may include one or more additional flame ports or rows of flame ports, such as a circumferential row of flame ports 400 that are useful to convey the flame from one lateral row to the other. The burner 104 may be formed, for example, as a metal casting, tube, or sheet. In this example, the burner 104 is a metal tube having the flame ports 110, 400 drilled, or otherwise formed into it, and the end of the tube may be closed and folded to form a connector 112 to join the burner 104 to the burner chamber 102.

[0055] Referring to Figures 5 and 6, the connector 112 is configured hold the burner 104 relative to the burner chamber 102 to prevent relative rotation between these parts. Specifically, the connector 112 has a longitudinally extending foot 500 that engages a tab 502 that extends inwardly from the wall of the burner chamber 102. The foot 500 has a notch 600 that is sized to receive the tab 502 to prevent the foot 500, and thus the connector 112 and the burner 104, from rotating relative to the burner chamber 102. This configuration is expected to be beneficial to allow the burner 104 to be assembled into the burner chamber 102 by sliding the burner along the longitudinal direction until the tab 502 is captured in the notch 504, at which point the rotatable assembly 114 can be rotated to the desired final angular orientation while the burner 104 remains rotationally fixed to the burner chamber 102.

[0056] Other embodiments may use different connectors 112 (e.g., a connector 112 formed by a separate part that is attached to the burner 104), or the connector may be omitted. Other alternatives and variations will be apparent to persons of ordinary skill in the art in view of the present disclosure.

[0057] Figure 7 shows an example of the mixing tube 116 construction. The mixing tube 116 is formed by two shells 700, each of which has an embossed region formed to shape one side of the mixing tube 116. The shells 700 are secured together such that the embossed regions form the mixing tube 116 therebetween. The shells 700 may comprise, for example, stamped metal sheets that are joined by welds, crimps, or the like. The shell 700 also may be configured with matching embossed regions to form the venturi 124, and may have cutouts to form the air inlets 128. [0058] Figure 7 also shows an example of a rotatable joint connecting the mixing tube outlet 118 to the burner 104. The rotatable joint is formed by a radial groove 702 in the rotatable assembly 114, and a radial flange on the burner 104. The radial flange 704 extends outward from the burner 104 and fits inside the radial groove 702. The radial groove 702 allows the radial flange 704, and thus the burner 104, to rotate about the longitudinal direction L, but prevents other relative motion. The fit between the radial flange 704 and radial groove 702 also may be selected to inhibit gas from exiting or entering at the rotatable joint. The radial groove 702 and radial flange 704 can be conveniently formed by swaging or stamping the parts forming the burner 104 and mixing tube 116. Other embodiments may use other rotatable connections between the burner 104 and the mixing tube 116, such as concentric tubes that may be secured to each other in different angular orientations with a clamp or screw, and so on. Other alternatives and variations will be apparent to persons of ordinary skill in the art in view of the present disclosure.

[0059] One or both of the shells 700 also may be configured to form other parts, such as a mounting flange 706 for holding the igniter 134 and/or flame sensor 136. For example, in the embodiment of Figures 4 through 8B, both the igniter 134 and the flame sensor 136 are mounted to the flange 706 to thereby be part of the rotatable assembly 114. Where the igniter 134 and flame sensor 136 are part of the rotating assembly 114, they preferably are configured to be operative at two or more angular orientations of the rotatable assembly 114 relative to the burner 104. For example, Figure 8B shows the rotatable assembly 114 at a first angular orientation relative to the burner 104, and Figure 8B shows the rotatable assembly 114 at a second angular orientation relative to the burner 104. In each of the positions shown in Figures 8A and 8B, the igniter 134 and flame sensor 136 are positioned adjacent one of the two rows of flame ports 110. Specifically, in Figure 8A, they are adjacent a first row of flame ports 110a on one side of the burner 104, and in Figure 8B they are adjacent a second row of flame ports 110b (see Figure 7) on the other lateral side of the burner 104. Thus, the igniter 134 and flame detector 136 are equally effective in either of the two positions.

[0060] The igniter 134 and flame detector 136 also may be effective throughout the angular range of motion 9 of the rotatable assembly 114. For example, as noted above, a circumferential row of flame ports 400 may extend around the burner 104, such that the igniter 134 and flame detector 136 are always adjacent one or more flame ports. Other alternatives and variations will be apparent to persons of ordinary skill in the art in view of the present disclosure, and it will be understood that other embodiments may have only one of the igniter 134 or flame detector 136 mounted as part of the rotatable assembly 114.

[0061] A burner assembly 100 according to these or other embodiments may be installed in various ways. In one example, the burner assembly 100 is assembled by installing the burner chamber 102 in the dryer cabinet 302, and then installing the combined burner 104 and rotatable assembly 114 in the cabinet 302 with the burner 104 inside the burner chamber 104. Installing the burner chamber 102 separately in this manner may be helpful to secure the burner chamber 102 to other parts of the airflow path within the dryer. During installation, the burner 104 may be rotated (in unison with or separately from the rotatable assembly 114) to orient the burner ports 110 at the desired orientation within the burner chamber 102 (e.g., rows on opposite lateral sides at an equal vertical height, as discussed above). Once the burner 104 is secured at the proper angular orientation relative to the burner chamber 102, the rotatable assembly 114 may be rotated to fit it into the desired space within the cabinet 302. Alternatively, the rotatable assembly 114 may be rotated to its final orientation relative to the burner 104 before the burner 104 is affixed to the burner chamber.

[0062] The rotatable assembly 114 may be rotationally fixed in its final position in various ways. For example, where the rotating joint requires significant force to cause relative rotation, the joint itself may have enough friction to prevent the rotatable assembly 114 from moving away from its desired final orientation. As another example, a fastener may be used to fix the rotatable assembly 114 to the burner chamber 102 or cabinet 302. As another example, the rotatable assembly 114 may be secured in place by attaching a rigid or rigidly mounted gas supply line 132 to the gas valve 130, such that the supply line 132 holds the rotatable assembly 114 in the desired orientation. Other alternatives and variations will be apparent to persons of ordinary skill in the art in view of the present disclosure.

[0063] The present disclosure describes a number of inventive features and/or combinations of features that may be used alone or in combination with each other or in combination with other technologies. The embodiments described herein are all exemplary, and are not intended to limit the scope of the claims. It will also be appreciated that the inventions described herein can be modified and adapted in various ways, and all such modifications and adaptations are intended to be included in the scope of this disclosure and the appended claims.