US20180274158A1

US20180274158A1 - Washing machine appliance with a tub counterweight

Info

Publication number: US20180274158A1
Application number: US15/468,813
Authority: US
Inventors: David Scott Dunn; Daniel Stephen Renz
Original assignee: Haier US Appliance Solutions Inc
Current assignee: Haier US Appliance Solutions Inc
Priority date: 2017-03-24
Filing date: 2017-03-24
Publication date: 2018-09-27

Abstract

A washing machine appliance includes a tub positioned within a cabinet. The tub has a wall and a plurality of ribs extending from the wall. A secondary wall is positioned on the plurality of ribs opposite the wall of the tub such that the secondary wall is spaced from the wall on the plurality of ribs. The wall of the tub, the plurality of ribs and the secondary wall define a plurality of cavities between the wall of the tub and the secondary wall. Each cavity of the plurality of cavities is at least partially filled or fillable with a liquid.

Description

FIELD OF THE INVENTION

The present subject matter relates generally to washing machine appliances and tub counterweights for washing machine appliances.

BACKGROUND OF THE INVENTION

During the operation of a washing machine, particularly during spin cycles, the washing machine can sometimes experience undesirable vibration. These vibrations can cause displacement of the washing machine as it “walks” across a surface, such as a floor. Typically, this event is due to the different shapes and densities of the clothing or other articles that are being washed which, after a washing cycle and draining the wash basket, can stick together and cause differences in the center of mass inside the wash basket. The vibration problem can also be caused by the introduction of relatively heavier articles into the wash basket, such as shoes.
In order to reduce vibration in washing machine appliances, various devices have been proposed. For example, washing machines have been equipped with counterweights, which are typically metal or concrete blocks mounted to the washing machine appliances' tub. The counterweights increase the tub's mass and provide mass damping of vibrations. However, securely mounting the counterweights on the tub can be difficult. In addition, the counterweights add to the overall cost of the appliance.
Accordingly, a washing machine appliance with features for reducing vibrations would be useful. In particular, an inexpensive device for reducing vibrations within a washing machine appliance would be useful.

BRIEF DESCRIPTION OF THE INVENTION

The present subject matter provides a washing machine appliance with a tub positioned within a cabinet. The tub has a wall and a plurality of ribs extending from the wall. A secondary wall is positioned on the plurality of ribs opposite the wall of the tub such that the secondary wall is spaced from the wall on the plurality of ribs. The wall of the tub, the plurality of ribs and the secondary wall define a plurality of cavities between the wall of the tub and the secondary wall. Each cavity of the plurality of cavities is filled or fillable with a liquid. Additional aspects and advantages of the invention will be set forth in part in the following description, or may be apparent from the description, or may be learned through practice of the invention.
In a first exemplary embodiment, a washing machine appliance is provided. The washing machine appliance includes a cabinet. A tub is positioned within the cabinet. The tub has an end wall and an annular side wall. The annular side wall extends from the end wall, and a plurality of ribs extends from the end wall. A basket is positioned within the tub such that the basket is rotatable within the tub. A secondary wall is positioned on the plurality of ribs opposite the end wall of the tub such that the secondary wall is spaced from the end wall on the plurality of ribs. The end wall, the plurality of ribs and the secondary wall define a plurality of cavities between the end wall and the secondary wall. Each cavity of the plurality of cavities is at least partially filled or fillable with a liquid.
In a second exemplary embodiment, a washing machine appliance is provided. The washing machine appliance includes a cabinet. A tub is positioned within the cabinet. The tub has a wall and a plurality of ribs extending from the wall. A basket is positioned within the tub such that the basket is rotatable within the tub. A secondary wall is positioned on the plurality of ribs opposite the wall of the tub such that the secondary wall is spaced from the wall on the plurality of ribs. The wall of the tub, the plurality of ribs and the secondary wall define a plurality of cavities between the wall of the tub and the secondary wall. Each cavity of the plurality of cavities is filled or fillable with a liquid.
In a third exemplary embodiment, a washing machine appliance is provided. The washing machine appliance includes a cabinet. A tub is positioned within the cabinet. A basket is positioned within the tub such that the basket is rotatable within the tub. The washing machine appliance also includes means for holding a sealed volume of filling on the tub. The sealed volume of filling weighs no less than two pounds and no more than sixty pounds.
These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures.

FIG. 1 provides a perspective view of a washing machine appliance according an exemplary embodiment of the present subject matter.

FIG. 2 provides a section view of the exemplary washing machine appliance of FIG. 1.

FIG. 3 provides a side, elevation view of a tub of the exemplary washing machine appliance of FIG. 1.

FIG. 4 provides a bottom, section view of the tub of FIG. 3 taken along the 4-4 line of FIG. 3.

FIG. 5 provides an exploded, section view of the tub of FIG. 3.

FIG. 6 provides a detail view of certain components of the tub of FIG. 5.

DETAILED DESCRIPTION

Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.
FIG. 1 provides a perspective view partially broken away of a washing machine appliance 50 according to an exemplary embodiment of the present subject matter. As may be seen in FIG. 1, washing machine appliance 50 defines a vertical direction V, a lateral direction L and a transverse direction T. The vertical direction V, lateral direction L and transverse direction T are mutually perpendicular and form an orthogonal direction system.
Washing machine appliance 50 includes a cabinet or apron 52 and a top panel or cover 54. A backsplash 56 extends from cover 54, and a control panel 58 including a plurality of input selectors 60 is coupled to backsplash 56. Control panel 58 and input selectors 60 collectively form a user interface input for operator selection of machine cycles and features, and in one embodiment a display 61 indicates selected features, a countdown timer, and other items of interest to machine users. A lid 62 is mounted to cover 54 and is rotatable about a hinge (not shown) between an open position (not shown) facilitating access to a wash tub 64 located within apron 52, and a closed position (shown in FIG. 1) forming a sealed enclosure over wash tub 64.
As illustrated in FIG. 1, washing machine appliance 50 is a vertical axis washing machine appliance. While the present disclosure is discussed with reference to a vertical axis washing machine appliance, those of ordinary skill in the art, using the disclosures provided herein, should understand that the subject matter of the present disclosure is equally applicable to other washing machine appliances, such as horizontal axis washing machine appliances.
A sub-washer unit 65 is mounted within apron 52. Sub-washer unit 65 includes tub 64 and a basket 70. Tub 64 includes a bottom wall 66 and a cylindrical side wall 68, and basket 70 is rotatably mounted within wash tub 64. Bottom wall 66 of tub 64 is spaced, e.g., vertically, from an open end of cylindrical side wall 68. A pump assembly 72 is located beneath tub 64 and basket 70 for gravity assisted flow when draining tub 64. Pump assembly 72 includes a pump 74 and a motor 76. A pump inlet hose 80 extends from a wash tub outlet 82 in tub bottom wall 66 to a pump inlet 84, and a pump outlet hose 86 extends from a pump outlet 88 to an appliance washing machine water outlet 90 and ultimately to a building plumbing system discharge line (not shown) in flow communication with outlet 90.
FIG. 2 provides a front elevation schematic view of certain components washing machine appliance 50 including wash basket 70 movably disposed and rotatably mounted in wash tub 64 in a spaced apart relationship from tub side wall 68 and tub bottom 66. Basket 70 includes a plurality of perforations therein to facilitate fluid communication between an interior of basket 70 and wash tub 64.
A hot liquid valve 102 and a cold liquid valve 104 deliver fluid, such as water, to basket 70 and wash tub 64 through a respective hot liquid hose 106 and a cold liquid hose 108. Liquid valves 102, 104 and liquid hoses 106, 108 together form a liquid supply connection for washing machine appliance 50 and, when connected to a building plumbing system (not shown), provide a fresh water supply for use in washing machine appliance 50. Liquid valves 102, 104 and liquid hoses 106, 108 are connected to a basket inlet tube 110, and fluid is dispersed from inlet tube 110 through a nozzle assembly 112 having a number of openings therein to direct washing liquid into basket 70 at a given trajectory and velocity. A dispenser (not shown in FIG. 2), may also be provided to produce a wash solution by mixing fresh water with a known detergent or other composition for cleansing of articles in basket 70.
An agitation element 116, such as a vane agitator, impeller, auger, or oscillatory basket mechanism, or some combination thereof is disposed in basket 70 to impart an oscillatory motion to articles and liquid in basket 70. In various exemplary embodiments, agitation element 116 may be a single action element (oscillatory only), double action (oscillatory movement at one end, single direction rotation at the other end) or triple action (oscillatory movement plus single direction rotation at one end, single direction rotation at the other end). As illustrated in FIG. 2, agitation element 116 is oriented to rotate about a vertical axis 118.
Basket 70 and agitator 116 are driven by a motor 120 through a transmission and clutch system 122. The motor 120 drives shaft 126 to rotate basket 70 within wash tub 64. Clutch system 122 facilitates driving engagement of basket 70 and agitation element 116 for rotatable movement within wash tub 64, and clutch system 122 facilitates relative rotation of basket 70 and agitation element 116 for selected portions of wash cycles. Motor 120 and transmission and clutch system 122 collectively are referred herein as a motor assembly 148 and may be a component of sub-washer unit 65.
Sub-washer unit 65 further incudes a vibration damping suspension system or mount 92 for supporting sub-washer unit 65 within apron 52. One end of mount 92 may be connected to sub-washer unit 65 while an opposite end of mount 92 is receivable within and/or coupled to at least one bracket 98. Thus, mount 92 may extend between sub-washer unit 65 and bracket 98 in order to suspend sub-washer unit 65 within apron 52.
Mount 92 can include a plurality of damping elements, such as piston-cylinder damping elements, coupled to the wash tub 64. The damping suspension system 92 can include other elements, such as a balance ring 94 disposed around the upper circumferential surface of the wash basket 70. The balance ring 94 can be used to counterbalance an out of balance condition for the wash machine as the basket 70 rotates within the wash tub 64.
Operation of washing machine appliance 50 is controlled by a controller (not shown) which is operatively coupled to the user interface input located on washing machine backsplash 56 (shown in FIG. 1) for user manipulation to select washing machine cycles and features. In response to user manipulation of the user interface input, the controller operates the various components of washing machine appliance 50 to execute selected machine cycles and features.
In an illustrative embodiment, laundry items are loaded into basket 70, and washing operation is initiated through operator manipulation of control input selectors 60 (shown in FIG. 1). Tub 64 is filled with water and mixed with detergent to form a wash fluid, and basket 70 is agitated with agitation element 116 for cleansing of laundry items in basket 70. That is, agitation element is moved back and forth in an oscillatory back and forth motion. In the illustrated embodiment, agitation element 116 is rotated clockwise a specified amount about the vertical axis of the machine, and then rotated counterclockwise by a specified amount. The clockwise/counterclockwise reciprocating motion is sometimes referred to as a stroke, and the agitation phase of the wash cycle constitutes a number of strokes in sequence. Acceleration and deceleration of agitation element 116 during the strokes imparts mechanical energy to articles in basket 70 for cleansing action. The strokes may be obtained in different embodiments with a reversing motor, a reversible clutch, or other known reciprocating mechanism. After the agitation phase of the wash cycle is completed, tub 64 is drained with pump assembly 72. Laundry items are then rinsed and portions of the cycle may be repeated, including the agitation phase, depending on the particulars of the wash cycle selected by a user.
During a spin cycle, wash basket 70 is rotated at relatively high speeds. Such high speed rotation may cause vibration and/or relative movement of the sub-washer unit 65 with respect to apron 52. As discussed in greater detail below, tub 64 includes features for damping vibrations.
FIG. 3 provides a side, elevation view of tub 64. FIG. 4 provides a bottom, section view of tub 64. FIG. 5 provides an exploded, section view of tub 64. As may be seen in FIGS. 3 through 5, tub 64 includes a ballast or counterweight system 200, e.g., at or adjacent a bottom or end portion of tub 64. It will be understood that while described in the context of washing machine appliance 50 and tub 64, counterweight system 200 may be used in or with any suitable washing machine appliance in alternative exemplary embodiments. For example, counterweight system 200 may be used in or with a horizontal axis washing machine appliance.
Counterweight system 200 includes a plurality of ribs 210 and a secondary wall 220. Ribs 210 extend, e.g., downwardly along the vertical direction V, from bottom wall 66 of tub 64. Thus, ribs 210 may be mounted to or formed on bottom wall 66 of tub 64. As an example, bottom wall 66 of tub 64, side wall 68 of tub 64 and ribs 210 may be integrally formed from a single, seamless piece of material, such as molded plastic.
Secondary wall 220 is positioned on ribs 210 opposite bottom wall 66 of tub 64. Thus, secondary wall 220 and bottom wall 66 of tub 64 may be spaced apart, e.g., along the vertical direction V, and ribs 210 may extend between and connect secondary wall 220 and bottom wall 66 of tub 64. Secondary wall 220 may be mounted or connected to ribs 210 using any suitable method or mechanism. For example, secondary wall 220 may be spin-welded, ultra-sonically welded, hot-plate welded, snap-fit, or blow molded onto ribs 210. In alternative exemplary embodiments, secondary wall 220 may be integrally formed with bottom wall 66 of tub 64, side wall 68 of tub 64 and ribs 210.
Bottom wall 66 of tub 64, side wall 68 of tub 64 and ribs 210 collectively define a plurality of cavities 230. Cavities 230 may be positioned between bottom wall 66 of tub 64 and secondary wall 220, e.g., along the vertical direction V, and at least one of ribs 210 may be positioned between adjacent cavities 230 within tub 64. Cavities 230 are filled or fillable with a liquid. Cavities 230 may be filled with any suitable liquid, such as water or an electrolyte. In alternative, exemplary embodiments, any suitable filling may be used instead of or in addition to the liquid, e.g., such as solid particles that are flowable together into or within cavities 230. The solid particles may be sand, aggregate, scrap, offal, pellets, etc. that at least partially fill cavities 230. The solid particles may not be directly attached or mounted to tub 64, e.g. with fasteners or adhesive, but rather may be held on or against tub 64 by being disposed within cavities 230.
As may be seen in FIG. 4, cavities 230 may be distributed across about all (e.g., at least seventy percent) of a cross-section plane of tub 64, e.g., that is perpendicular to the vertical direction V. Thus, some of cavities 230 may be positioned at an outer edge of bottom wall 66 of tub 64 and/or directly below side wall 68 of tub 64, e.g., along the vertical direction V, and proximate a center of bottom wall. In addition, cavities 230 may be uniformly distributed about the vertical axis 118 of wash basket 70. Cavities 230 may also be sized to collectively hold no less than one gallon of the liquid or no less than two gallons of the liquid.
In addition to forming a component of counterweight system 200, ribs 210 may also stiffen bottom wall 66 of tub 64. Thus, ribs 210 may limit deflection of bottom wall 66 of tub 64, e.g., along the vertical direction V. In certain exemplary embodiments, ribs 210 may be a structural feature on tub 64, and cavities 230 may be formed within voids formed between ribs 210 at a bottom of tub 64. When secondary wall 220 is integrally formed with bottom wall 66 of tub 64, side wall 68 of tub 64 and ribs 210, cavities 230 may be formed with a gas-assist molding process.
The liquid disposed within cavities 230 increases a weight and/or mass of tub 64. Thus, during operation of washing machine appliance 50, the liquid within cavities 230 assists with mass dampening of vibrations within sub-washer unit 65. As an example, cavities 230 may be completely or almost completely filled with the liquid, e.g., at least ninety percent (90%) filled with the liquid, and a weight of the liquid within cavities 230 may be is no less than two pounds (2 lbs.) and no greater than sixty pounds (60 lbs.). As another example, the weight of the liquid within cavities 230 may be is no less than ten pounds (10 lbs.) and no greater than thirty pounds (30 lbs.). Thus, tub 64 may be significantly heavier and/or more massive, relative to a similar tub without liquid filled cavities.
In certain exemplary embodiments, the liquid may be flowable between adjacent cavities 230. Thus, e.g., each rib 210 may include a notch, a hole, a passage, etc. that allows the liquid to flow through ribs 210 between adjacent cavities 230. Thus, cavities 230 may be in fluid communication with one another such that the liquid is flowable between cavities 230. By flowing liquid between cavities 230, the liquid may provide dynamic damping in addition to mass damping.
The liquid may be significantly cheaper than other counterweights, such as steel or concrete counterweights. In addition, forming cavities 230 and holding the liquid within cavities 230 may be significantly more reliable than mounting steel or concrete counterweights on tub 64. In certain exemplary embodiments, tub 64 does not include metal or concrete counterweights and relies upon the liquid within cavities 230 to assist with mass dampening of vibrations within sub-washer unit 65. In other exemplary embodiments, the liquid within cavities 230 may supplement steel or concrete counterweights on tub 64 with mass dampening of vibrations within sub-washer unit 65.
As may be seen in FIGS. 3 and 4, secondary wall 220 may be positioned outside of the interior of tub 64. Thus, ribs 210 may extend, e.g., downwardly along the vertical direction V, from bottom wall 66 of tub 64 away from the interior of tub 64. In alternative exemplary embodiments, secondary wall 220 may be positioned within the interior of tub 64 and form the bottom of tub 64 for wash fluid therein. Thus, ribs 210 may extend, e.g., upwardly along the vertical direction V, from bottom wall 66 of tub 64 into the interior of tub 64. Positioning secondary wall 220 within tub 64 may be advantageous when bottom wall 66 of tub 64 and side wall 68 of tub 64 are integrally formed, e.g., of molded plastic, because leakage of the liquid from cavities 230 at an interface between ribs 210 and secondary wall 220 is contained within the interior tub 64 rather than spilling below tub 64.
It will be understood that secondary wall 220 may be mounted at other locations on tub 64 to form cavities 230. For example, as shown in FIG. 3, tub 64 also includes ribs 210 on side wall 68 of tub 64. Secondary wall 220 may be mounted to the ribs 210 on side wall 68 of tub 64 in alternative exemplary embodiments to form cavities 230 at side wall 68 of tub 64. Thus, secondary wall 220 may be mounted to ribs 210 at any suitable location on tub 64 to form liquid fillable cavities 230. As may be seen from the above, the present subject matter is not limited to any particular location on tub 64 for mounting secondary wall 220 on ribs 210 and forming liquid fillable cavities 230. Any feature of secondary wall 220 and cavities 230 discussed in the context of bottom wall 66 of tub 64 may also be used with or formed at any other location on tub 64.
FIG. 6 provides a detail view of certain components of tub 64. As may be seen in FIG. 6, bottom wall 66 of tub 64 defines at least one hole 250. Hole 250 extends, e.g., along the vertical direction V, through bottom wall 66 of tub 64 between the interior of tub 64 and one of cavities 230. In alternative exemplary embodiments, hole 250 may extend through secondary wall 220. Cavities 230 are fillable through hole 250. Thus, the liquid may flow through hole 250 into cavities 230. As an example, cavities 230 may be pre-filled with the liquid during assembly of washing machine appliance 50. Thus, a manufacturer of washing machine appliance 50 may fill cavities 230 with the liquid and may seal hole 250. As another example, cavities 230 may be filled in-situ after installation of washing machine appliance. In particular, during operation of washing machine appliance 50, the liquid may flow into cavities 230 from the interior of tub 64. The hole 250 may be left open or may be plugged. Alternatively, a check valve 252 may be positioned at hole 250. Check valve 252 is configured to allow the liquid to flow through hole 250 into cavities 230 and also to limit liquid flow out of cavities 230 through hole 250. Thus, cavities 230 may be filled with the liquid through check valve 252, and check valve 252 may block liquid flow out of cavities 230 through hole 250.
This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.

Claims

What is claimed is:

1. A washing machine appliance, comprising:

a cabinet;

a tub positioned within the cabinet, the tub having an end wall, an annular side wall and a plurality of ribs, the annular side wall extends from the end wall and the plurality of ribs extend from the end wall;

a basket positioned within the tub such that the basket is rotatable within the tub; and

a secondary wall positioned on the plurality of ribs opposite the end wall of the tub such that the secondary wall is spaced from the end wall on the plurality of ribs;

wherein the end wall, the plurality of ribs and the secondary wall define a plurality of cavities between the end wall and the secondary wall, each cavity of the plurality of cavities at least partially filled or fillable with a liquid.

2. The washing machine appliance of claim 1, wherein the tub defines an interior volume that is fillable with wash fluid, the basket positioned within the interior volume of the tub, the secondary wall positioned at the interior volume of the tub.

3. The washing machine appliance of claim 2, wherein the secondary wall defines at least one hole that extends between the interior volume of the tub and one of the plurality of cavities.

4. The washing machine appliance of claim 3, further comprising at least one check valve, each check valve of the at least one check valve positioned at a respective hole of the at least one hole, the at least one check valve configured to allow liquid flow into plurality of cavities and limit liquid flow out of the plurality of cavities.

5. The washing machine appliance of claim 1, wherein the tub defines an interior volume that is fillable with wash fluid, the basket positioned within the interior volume of the tub, the secondary wall positioned outside of the interior volume of the tub such that the plurality of ribs extend from the end wall away from the interior volume of the tub.

6. The washing machine appliance of claim 5, wherein the end wall defines at least one hole that extends between the interior volume of the tub and one of the plurality of cavities.

7. The washing machine appliance of claim 6, further comprising at least one check valve, each check valve of the at least one check valve positioned at a respective hole of the at least one hole, the at least one check valve configured to allow liquid flow into plurality of cavities and limit liquid flow out of the plurality of cavities.

8. The washing machine appliance of claim 1, wherein each cavity of the plurality of cavities is at least ninety percent filled with the liquid.

9. The washing machine appliance of claim 8, wherein a weight of the liquid within the plurality of cavities is no less than two pounds and no greater than sixty pounds.

10. The washing machine appliance of claim 1, wherein the liquid comprises water or an electrolyte.

11. The washing machine appliance of claim 1, wherein the plurality of ribs are molded with the end wall, the secondary wall spin-welded, ultrasonically-welded, snap-fit, hot-plate welded or blow molded onto the plurality of ribs.

12. The washing machine appliance of claim 1, wherein no concrete or metal counterweight is mounted to the tub.

13. The washing machine appliance of claim 1, wherein the basket is rotatable about a vertical axis within the tub, and the end wall is a bottom wall of the tub.

14. A washing machine appliance, comprising:

a cabinet;

a tub positioned within the cabinet, the tub having a wall and a plurality of ribs extending from the wall;

a secondary wall positioned on the plurality of ribs opposite the wall of the tub such that the secondary wall is spaced from the wall on the plurality of ribs;

wherein the wall of the tub, the plurality of ribs and the secondary wall define a plurality of cavities between the wall of the tub and the secondary wall, each cavity of the plurality of cavities filled or fillable with a liquid.

15. The washing machine appliance of claim 14, wherein the tub defines an interior volume that is fillable with wash fluid, the basket positioned within the interior volume of the tub, the secondary wall positioned outside of the interior volume of the tub such that the plurality of ribs extend from the wall away from the interior volume of the tub.

16. The washing machine appliance of claim 15, wherein the wall defines at least one hole that extends between the interior volume of the tub and one of the plurality of cavities.

17. The washing machine appliance of claim 14, wherein the wall of the tub is one of a cylindrical side wall and an end wall, the end wall positioned at an end of the cylindrical side wall.

18. The washing machine appliance of claim 14, wherein each cavity of the plurality of cavities is at least ninety percent filled with the liquid, and a weight of the liquid within the plurality of cavities is no less than ten pounds and no greater than thirty pounds.

19. The washing machine appliance of claim 14, wherein the liquid comprises one or more of water and a salt.

20. A washing machine appliance, comprising:

a cabinet;

a tub positioned within the cabinet;

means for holding a sealed volume of filling on the tub,

wherein the sealed volume of filling weighs no less than two pounds and no more than sixty pounds.