Patent Description:
The present invention relates to sewer cleaning machines for cleaning drains, pipes, or other conduits.

Sewer cleaning machines are used to clean clogs and debris out of drains, sewers, and the like. Smaller handheld drain cleaners may be used to clean household drains from sinks or shower drains. However, larger and heavier cleaning machines are often used to clean sewers and industrial drains. A sewer cleaning machine may have as much as <NUM>-<NUM> (<NUM>-<NUM> ft) of cable and a weight of <NUM>-<NUM> (<NUM>-<NUM> lbs). Accordingly, some sewer cleaning machines may be cumbersome to transport.

<CIT> discloses a drain cleaning machine. According to an abstract of this document, a drain cleaning machine is disclosed which is of the character comprising a frame supporting a rotatable drum which is driven by a motor through an endless belt. The drum contains a flexible drain cleaning snake which is rotatable with the drum and axially displaceable into and out of the drum, and the frame supports a snake feeding device through which the snake extends and by which the snake is displaced into and out of the drum. The frame is wheeled to facilitate transportation of the machine from one location to another. The drum, drum shaft and bearing are constructed as a unit removably mounted on the frame. The drive motor is pivotally mounted on the frame and spring biased to tension the drive belt and to facilitate separa- tion of the drive belt from the drum to facilitate removal of the drum unit from the frame. Stabilizer members are associated with the wheels on the frame and are pivotal between storage and use positions in which the wheels respectively engage an underlying surface and are elevated above the surface to stabilize the machine against rolling and tipping displacement during use. The snake feeding device includes three rollers which engage the snake to feed the latter inwardly and outwardly of the drum in response to rotation of the drum, and two of the rollers are radially adjustable relative to the snake through corresponding cam arrangements so that the feeding device can accommodate snakes having different diameters A biasing compression spring is provided between a radially outer end of body member and a radially inner end of an adjusting screw component having a handle for adjusting the compression of spring and thus the pressure exerted on the snake by the rollers.

<CIT> discloses a drum type sewer cleaner. According to an abstract of this document, a sewer cleaning machine includes a rotatable drum containing a coiled cable, a motor for rotating the drum, a balanced double cable guide rotatable with respect to the drum, a forward cable guide support which is pivotally mounted for tilting the drum forward to drain or remove the drum, an auxiliary handle for lifting the drum, and easily removed shrouding for the drum and motor. The drum is formed of sheet metal and includes a rearwardly extending annular wall which is driven by a roller coaxially attached to the motor shaft by an adjustable clutch. The clutch can be infinitely adjusted from total slip to total lock, and the motor stall torque is chosen to be less than the torque required to break the cable. A handle is bent to provide balance for the machine when it is moved and to support the machine when it is turned on its back.

<FIG> illustrate a sewer cleaning machine <NUM> including a frame <NUM>, a drum housing <NUM>, a motor housing <NUM>, a power supply <NUM>, and a track <NUM>. The frame <NUM> includes a handle <NUM>, a base <NUM> that supports the drum housing <NUM>, and wheels <NUM>. A drum <NUM> is rotatably supported within the drum housing <NUM> and includes a cable (not shown in <FIG>) that is extendable out of an opening <NUM> on the drum <NUM>. In some embodiments, the drum <NUM> is a cage-style drum that when the drum housing <NUM> is opened allows easy access to the cable so a user can inspect the cable. The cable is extendable out of the drum with a cable feed device <NUM>, which is discussed in more detail below. A first motor <NUM> is supported within the motor housing <NUM> and is coupled to the drum <NUM>. The first motor <NUM> is operable to rotate the drum <NUM>. Rotation of the drum <NUM> creates friction between an inner surface of the drum <NUM> and the cable, which causes the cable to spin to facilitate clearing debris from a drain pipe or another conduit.

The track <NUM> is configured to engage a surface, such as stairs or a ramp to help a user maneuver the sewer cleaning machine <NUM>. In the illustrated embodiment, the track <NUM> is positioned on the opposite side of the frame <NUM> as the drum <NUM>. For example, the drum <NUM> is positioned on a front side of the frame <NUM> and the track <NUM> is positioned on a back side of the frame <NUM>. In other embodiments the track <NUM> can be positioned on either the left or right side of the frame <NUM>.

The track <NUM> includes a substantially horizontal drive shaft <NUM> with a first drive roller <NUM> at one end and a second drive roller <NUM> at another end. A first endless belt <NUM> extends around the first drive roller <NUM> and a first idler roller <NUM>, and a second endless belt <NUM> extends around the second drive roller <NUM> and a second idler roller <NUM>. The endless belts <NUM>, <NUM> extend substantially vertically along a length of the frame <NUM>. In some embodiments, the track <NUM> may only include a first endless belt <NUM> and respective rollers <NUM>, <NUM> rather than including first and second endless belts <NUM>, <NUM>. In some embodiments, the endless belts <NUM>, <NUM> include traction elements that assists in gripping a surface, ledge, or other object. For example, in the illustrated embodiment, the endless belts <NUM>, <NUM> include castellations <NUM>, or projections, that help grip various surfaces. In further embodiments, the endless belts <NUM>, <NUM> include replaceable cleats that can be replaced when worn down instead of replacing the entire track <NUM>. In other embodiments, the track <NUM> can articulate or expand and retract to better climb stairs.

As shown in <FIG>, a second motor <NUM> is supported by the frame <NUM> and is coupled to the drive shaft <NUM> of the track <NUM>. The second motor <NUM> is operable to rotate the drive shaft <NUM> and thus the drive rollers <NUM>, <NUM> to facilitate rotation of the endless belts <NUM>, <NUM>. In other embodiments, the track <NUM> is passively driven rather than motor driven. For example, the endless belts <NUM>, <NUM> of the track <NUM> may be rotated by engagement with a surface, such as stairs or a ramp, as a user pulls the sewer cleaning machine <NUM>. Regardless of whether the track <NUM> is motor driven or passively driven, the track <NUM> is decoupled from the drum <NUM> in that the track <NUM> is independently rotated without affecting the rotation of the drum <NUM>.

In the illustrated embodiment, both the first and second motors <NUM>, <NUM> are powered by the power supply <NUM> that is supported on the frame <NUM>. The first and second motors <NUM>, <NUM> are, for example, brushless motors. In additional embodiments, the first and second motors <NUM>, <NUM> are variable two speed motors. In the illustrated embodiment, the power supply <NUM> includes a battery receptacle that receives a battery pack to provide D/C power to the sewer cleaning machine <NUM>. For example, the battery receptacle may removably receive a rechargeable power tool battery pack. In further embodiments, the power supply <NUM> may receive more than one battery pack to power the sewer cleaning machine <NUM>. In alternative embodiments, the power supply <NUM> may be coupled to a power outlet to provide A/C power to the sewer cleaning machine <NUM>.

The power supply <NUM> includes a controller that may control operation of the first and second motors <NUM>, <NUM>. In some embodiments, the controller ensures that when one motor is operating the other motor is locked out and cannot be run. As previously mentioned, the track <NUM> is decoupled from the drum <NUM> such that rotation of one is independent of the other. In some embodiments, the controller actively decouples the track <NUM> from the drum <NUM> so that they cannot operate at the same time. In other embodiments, the track <NUM> is decoupled from the drum <NUM> only by lack of mechanical connection to the drum <NUM>. Additionally, the sewer cleaning machine <NUM> may include switches, buttons, a user interface, or other control features that allow a user to selectively control the sewer cleaning machine <NUM>. Further, the power supply <NUM> or the battery may include a battery fuel gauge to indicate to a user how much longer the battery will last. In addition, the sewer cleaning machine <NUM> may include battery detection that indicates to a user if the sewer cleaning machine <NUM> has enough power to climb a standard set of stairs and, if not, lock out the tracks <NUM> from being operated.

As shown in <FIG>, the sewer cleaning machine <NUM> includes a handle <NUM>. The handle <NUM> may be an articulating handle that moves relative to the frame by, for example, depressing a pin <NUM> within a slot <NUM> and moving the handle <NUM> until the pin <NUM> aligns with another slot <NUM>. The handle <NUM> may further include a user interface <NUM> (e.g., actuators, indicators, a touchscreen, etc.) through which a user may control the sewer cleaning machine <NUM>.

As shown in <FIG>, the sewer cleaning machine <NUM> may include a cable counter <NUM>. The cable counter <NUM> may be positioned adjacent the opening <NUM> on the drum <NUM> to determine the amount of cable that has been payed out from the drum <NUM>. The cable counter <NUM> includes a stationary roller <NUM>, a movable roller <NUM>, a gear system <NUM> coupled to the stationary roller <NUM>, and a counter <NUM> coupled to the gear system <NUM>. The cable is directed out of the drum <NUM> between the stationary roller <NUM> and the movable roller <NUM>. The movable roller <NUM> is biased toward the stationary roller <NUM> by one or more springs to maintain pressure on the cable between the rollers <NUM>, <NUM>. As the cable is payed out from the drum <NUM>, the cable rotates the stationary roller <NUM>, which transfers rotation to the gear system <NUM>. The gear system <NUM> uses a gear reduction mechanism to equate the amount of roller rotation to the amount of cable payed out for incrementing on the counter <NUM>. The counter <NUM> displays the increasing amount of cable payed out. Similarly, as the cable is returned to the drum <NUM>, the counter <NUM> reverses directions and counts down the amount of cable that has been payed out. In the illustrated embodiment, the counter <NUM> includes a mechanical meter having dials that rotate to display the amount of cable. In other embodiments, the counter <NUM> may include a digital screen or meter. The illustrated cable counter <NUM> uses an automated design, meaning no user input is required to operate. In some embodiments, the counter <NUM> may include a reset button or other means to reset (e.g., zero) the counter <NUM> anytime while the cable is being payed out.

<FIG> illustrates the cable feed device <NUM>, which is not according to the invention, as defined by the appended claims. The cable feed device <NUM> is removably coupled to the opening <NUM> with fasteners. The cable feed device <NUM> includes a housing <NUM> and a handle <NUM> with a trigger <NUM>. With reference to <FIG>, inside the housing <NUM>, the cable feed device <NUM> includes three forward bearings <NUM> and three reverse bearings <NUM>. The forwards bearings <NUM> assist in extending the cable out of the drum <NUM>, while the reverse bearings <NUM> assist in retracting the cable back into the drum <NUM>. The three forward bearings <NUM> are coupled to a first cam ring <NUM> that includes three cam surfaces <NUM> corresponding to the three forward bearings <NUM>. The three reverse bearings <NUM> are coupled to a second cam ring <NUM> that includes three cam surfaces <NUM> that correspond to the three reverse bearings <NUM>. The first and second cam rings <NUM>, <NUM> are coupled to the handle <NUM>. As seen in <FIG>, all the bearings <NUM>, <NUM> are spring loaded away from the cable. As seen in <FIG>, by rotating the handle <NUM> clockwise, the first and second cam rings <NUM>, <NUM> are rotated clockwise, and the cam surfaces <NUM> of the first cam ring <NUM> engage the three forward bearings <NUM> pushing them into contact with the cable to assist in paying out the cable. By rotating the handle <NUM> counter-clockwise, the first and second cam rings <NUM>, <NUM> are rotated counter-clockwise, and the cam surfaces <NUM> of the second cam ring <NUM> engage the three reverse bearings <NUM> pushing them into contact with the cable to assist in retracting the cable.

With reference to <FIG>, the cable feed device <NUM> further includes a locking element <NUM> that locks the handle <NUM> in place while either extending or retracting the cable from the drum <NUM>. The locking element <NUM> includes a first ratchet gear <NUM>, a second ratchet gear <NUM>, a first forward pawl <NUM>, and a second reverse pawl <NUM>. The first ratchet gear <NUM> is axially offset from the second ratchet gear <NUM> along an axis A defined by the cable. Similarly, the first forward pawl <NUM> is axially offset from the second reverse pawl <NUM> along the axis A defined by the cable. As such, the first forward pawl <NUM> corresponds to the first ratchet gear <NUM> and the second reverse pawl <NUM> corresponds to the second ratchet gear <NUM>. Both the first forward pawl <NUM> and the second reverse pawl <NUM> are rotationally coupled to the trigger <NUM>. The first forward pawl <NUM> and the second reverse pawl <NUM> are both resiliently biased towards each other so that when the handle <NUM> is moved in a clockwise direction teeth <NUM> on the first forward pawl <NUM> easily pass over teeth <NUM> on the first ratchet gear <NUM>, and when the handle <NUM> is moved in the counter-clockwise direction teeth <NUM> on the second reverse pawl <NUM> can easily pass over teeth <NUM> on the second ratchet gear <NUM>.

As shown in <FIG>, to pay out cable from the drum <NUM>, a user rotates the handle <NUM> clockwise, which engages the three forward bearings <NUM> with the cable. At this time, the first forward pawl <NUM> slides over the first ratchet gear <NUM>. Once the handle <NUM> is in the desired position, the user releases the handle <NUM>, causing the teeth <NUM> on the first forward pawl <NUM> to engage the teeth <NUM> on the first ratchet gear <NUM>, thereby locking the handle <NUM> in place due to the bias of the first forward pawl <NUM>. Similarly, to retract the cable back into the drum <NUM>, a user rotates the handle <NUM> clockwise, which engages the three reverse bearings <NUM> with the cable. The second reverse pawl <NUM> slides over the second ratchet gear <NUM> and once the user releases the handle <NUM>, the teeth <NUM> on the second reverse pawl <NUM> engage the teeth <NUM> on the second ratchet gear <NUM> to lock the handle <NUM> in place due to the bias of the second reverse pawl <NUM>.

In order to unlock the handle <NUM> and stop the cable from extending/retracting from the drum <NUM>, a user pulls the trigger <NUM> on the handle <NUM>, which will pull either the first or second pawl <NUM>, <NUM> out of engagement with either the first or second ratchet gear <NUM>, <NUM>. The handle <NUM> can then be rotated back to the neutral position. The cable feed device <NUM> allows for the cable to be payed out either manually (e.g., when the handle <NUM> is in a neutral position) or automatically by engaging either the three forward bearings <NUM> or the three reverse bearings <NUM>. The handle <NUM> and locking element provide quick means to easily transition the cable from being automatically payed out or manually payed out.

<FIG> illustrate an embodiment of a cable feed device <NUM>, according to the invention, for use with a sewer cleaning machine. The cable feed device <NUM> is coupled to a drum of the sewer cleaning machine by a mount <NUM>. In some embodiments, the mount <NUM> can be bolted to the drum. With reference to <FIG>, the cable feed device <NUM> includes a passageway <NUM> that is aligned with an opening of the drum and guides a cable <NUM> from the drum into the drain. The cable feed device <NUM> includes a plurality of bearings <NUM> for feeding the cable <NUM> into the drain, a first lever <NUM> for actuating the bearings <NUM>, a second lever <NUM> for controlling the feed direction (i.e., forward or reverse), and a locking assembly <NUM> for maintaining the bearings <NUM> in an actuated position. These components are supported by a housing <NUM>. In the illustrated embodiment, the housing <NUM> is divided into a main housing <NUM> that supports the first lever <NUM> and at least one of the bearings <NUM>, and a secondary housing <NUM> that supports the second lever <NUM> and at least one of the plurality of bearings <NUM>.

Referring to <FIG>, the bearings <NUM> are arranged circumferentially around the cable <NUM>. The illustrated embodiment includes three bearings <NUM>; however, in other embodiments, a greater or fewer number of bearings <NUM> may be used. Each of the bearings <NUM> includes a bearing carrier <NUM> and a roller <NUM>. The roller <NUM> is rotatably supported within the bearing carrier <NUM>. In the illustrated embodiment, a first bearing <NUM> is positioned within the main housing <NUM> and is located above the cable <NUM>. A second bearing <NUM> and a third bearing <NUM> are positioned within the secondary housing <NUM>. The second and third bearings <NUM> are located below the cable <NUM>. The first bearing <NUM> is movable within the main housing <NUM> to selectively engage the cable <NUM>. The second and third bearings <NUM> are fixed relative to the cable <NUM>.

With reference to <FIG>, the first lever <NUM> can selectively actuate the bearings <NUM> to engage the cable <NUM> so that the cable <NUM> may be fed into the drain. In the illustrated embodiment, the first lever <NUM> is a U-shaped lever with a handle portion <NUM> and two side portions <NUM> extending from opposite ends of the handle portion <NUM>. The first lever <NUM> also includes a lever arm <NUM> extending between the two side portions <NUM> on an opposite side as the handle portion <NUM>. In other embodiments, the first lever <NUM> can be different shapes and sizes.

<FIG> illustrate the first lever <NUM> and the bearings <NUM> in a disengaged position, and <FIG> illustrate the first lever <NUM> and the bearings <NUM> in an engaged position. When the first lever <NUM> is in a disengaged position, the first lever <NUM> is oriented in an upward direction and the first bearing <NUM> is spaced apart from the cable <NUM> such that there is a clearance between the first bearing <NUM> and the cable <NUM>. When the first lever <NUM> is in the engaged position, the first lever <NUM> is oriented in a horizontal direction and the first bearing <NUM> engages the cable <NUM>. Specifically, the first lever <NUM> can be rotated about an axis B from the disengaged position to the engaged position. In the illustrated embodiment, the axis B is perpendicular to the axis A defined by the cable <NUM>. However, in other embodiments, the axis B can be arranged parallel to the axis A defined by the cable <NUM>. As the first lever <NUM> is rotated to the engaged position, the lever arm <NUM> forces a plunger <NUM> downward, which, in turn, forces the first bearing <NUM> downward and into engagement with the cable <NUM>.

The first lever <NUM>, the plunger <NUM>, and the first bearing <NUM> are biased toward the disengaged position by one or more springs. In the illustrated embodiment, a first return spring 1086a biases the plunger <NUM> and the first lever <NUM> toward the disengaged position, and a second return spring 1086b (<FIG>) biases the bearing <NUM> toward the disengaged position. When the first lever <NUM> is rotated to the engaged position, the springs <NUM>, create a clamping force on the cable <NUM>. The springs <NUM> also exert a return force on the first bearing <NUM>, the plunger <NUM>, and the first lever <NUM> to return to the disengaged position. The locking assembly <NUM> can selectively resist the force of the springs <NUM> to maintain the first roller <NUM> in the engaged position with the cable <NUM>.

Referring to <FIG> and <FIG>, the locking assembly <NUM> includes a ratchet gear <NUM>, at least one pawl <NUM>, and a release button <NUM>. In the illustrated embodiment, the ratchet gear <NUM> is an extension of the plunger <NUM>. As shown in <FIG>, the ratchet gear <NUM> includes a set of teeth <NUM> on each side of the gear. As previously mentioned, when the first lever <NUM> is rotated towards the engaged position, the plunger <NUM> and the first bearing <NUM> are moved in a downward direction, whereby the first bearing <NUM> engages the cable <NUM>. The pawls <NUM> engage the ratchet gear <NUM> and maintain the plunger <NUM> and the first bearing <NUM> in the downward position. In particular, the pawls <NUM> each have a set of teeth <NUM> that engage with the teeth <NUM> of the ratchet gear <NUM>. Therefore, when the first lever <NUM> is released, first bearing <NUM> will continue to engage the cable <NUM>.

To release the locking assembly <NUM>, a user actuates (e.g., depresses) the release button <NUM> to disengage the pawls <NUM> from the ratchet gear <NUM>. Specifically, pressing the release button <NUM> downward pivots two linkages <NUM>, one corresponding to each pawl <NUM>. Pivoting of the linkages causes the pawls <NUM> to rotate away from the ratchet gear <NUM> so that the teeth <NUM> of the pawls <NUM> disengage from the teeth <NUM> of the ratchet gear <NUM>. Once the pawls <NUM> are disengaged from the ratchet gear <NUM>, the return springs <NUM> bias the first bearing <NUM> and the plunger <NUM> upward and away from the cable <NUM>.

As previously mentioned, the cable feed device <NUM> includes a second lever <NUM> for controlling the feed direction (i.e., forward or reverse). Referring back to <FIG>, the second lever <NUM> has a control hub <NUM> and an elongated handle <NUM> extending from the control hub <NUM>. The control hub <NUM> engages with the bearings <NUM> and adjusts the bearings <NUM> to different orientations corresponding to different feed directions. The handle <NUM> rotates the control hub <NUM> to thereby adjust the bearings <NUM>. Specifically, in the illustrated embodiment, the control hub <NUM> includes a socket <NUM> corresponding to each of the bearings <NUM>. Furthermore, each bearing <NUM> includes a shaft <NUM> (<FIG>) extending from the bearing carrier <NUM> into the respective socket <NUM>. When the control hub <NUM> rotates, the sockets <NUM> engage the shafts <NUM>, causing the bearing carriers <NUM> to rotate and the rollers <NUM> to be oriented to different feed positions. In the illustrated embodiment, the control hub <NUM> also includes a series of guide slots <NUM> between the sockets <NUM>. Bolts or guide pins <NUM> extend from the housing <NUM> through the guide slots <NUM> to help guide the control hub <NUM> between different rotational positions.

<FIG> illustrate the second lever <NUM> and the bearings <NUM> in a neutral position (<FIG>), a forward position (<FIG>), and a reverse position (<FIG>). In the neutral position, the second lever <NUM> is oriented centrally such that the second lever <NUM> extends vertically upward and is centrally aligned relative to the main housing <NUM> and the first lever <NUM>. The bearings <NUM> are arranged with the roller <NUM> oriented generally perpendicular to the axis A defined by the cable <NUM>. When in the neutral position, the bearings <NUM> do not feed the cable <NUM> in either a forward or a reverse direction. Rather, the cable <NUM> rotates in place due to the rotation of the drum.

In the forward position, the second lever <NUM> is rotated clockwise (i.e., to the right when oriented as shown in <FIG>). In the illustrated embodiment, the guide pins <NUM> engage with first ends <NUM> of the guide slots <NUM> to limit rotation of the second lever <NUM>. The bearings <NUM> are arranged with the roller <NUM> oriented at a first acute angle relative to the axis A defined by the cable <NUM>. In the forward position, the bearings <NUM> are oriented at an angle that, when engaged with the cable <NUM>, pays out the cable <NUM> from the drum into the drain.

In the reverse position, the second lever <NUM> is rotated counter clockwise (i.e., to the left when oriented as shown in <FIG>). The guide pins <NUM> engage with second ends <NUM> of the guide slots <NUM> to limit rotation of the second lever <NUM>. The bearings <NUM> are arranged with the rollers <NUM> oriented at a second acute angle relative to the axis A defined by the cable <NUM>.

In operation, a user rotates the handle of the second lever <NUM> to orient the bearings <NUM> in the desired feed position (i.e., neutral, forward, or reverse). The user then rotates the first lever <NUM> to an engaged position, whereby the bearings <NUM> engage the cable <NUM>. As described in greater detail above, the plunger <NUM> and the first bearing <NUM> are translated downward towards the cable <NUM>. The first bearing <NUM> engages the cable <NUM> such that all three bearings <NUM> are compressed around the cable <NUM>. Accordingly, once engaged with the cable <NUM>, the bearings <NUM> will feed the cable <NUM> in the direction corresponding to the position of the second lever <NUM>. The locking assembly <NUM> locks the bearings <NUM> in the engaged position, which will continue to pay out the cable <NUM> until the locking assembly <NUM> is released. Specifically, the ratchet gear <NUM> and pawls <NUM> maintain the plunger <NUM> and the first bearing <NUM> in the engaged position. To unlock the cable feed device <NUM>, a user presses on the release button <NUM> to disengage the pawls <NUM> from the ratchet gear <NUM>. Once released, the return springs <NUM> bias the plunger <NUM> and the first bearing <NUM> away from the cable <NUM> towards the disengaged position.

Referring back to <FIG>, the sewer cleaning machine <NUM> is shown in a first operational position. In this position, the drum housing <NUM> of the sewer cleaning machine <NUM> is supported on a surface to facilitate the clearing of debris from a conduit. In operation, the power supply <NUM> supplies power to the first motor <NUM> to spin the drum <NUM>. The cable feed device <NUM> draws cable from inside the drum <NUM> so that a user may extend the cable into a drain. Rotation of the drum <NUM> causes the cable to spin, assisting in the removal of debris from the drain.

With reference to <FIG>, the sewer cleaning machine <NUM> is shown in a second transport position. A user may tilt the frame <NUM>, lifting the housing <NUM> off of a surface and allowing the wheels <NUM> to transport the sewer cleaning machine <NUM> along the surface. However, due to the weight, the sewer cleaning machine <NUM> may be difficult to lift. Specifically, a user may have difficulty transporting the sewer cleaning machine <NUM> on stairs. During transportation, the track <NUM> may assist in lifting the sewer cleaning machine <NUM> both up and down stairs. A user may first position the sewer cleaning device <NUM> so that the track <NUM> engages the stairs. Once the track <NUM> engages the stairs, the user can control the power supply <NUM> to operate the second motor <NUM>. The second motor <NUM> rotates the drive shaft <NUM>, thereby rotating the endless belts <NUM>, <NUM>. As the endless belts rotate <NUM>, <NUM>, the traction on the belts <NUM>, <NUM> assist in pulling the sewer cleaning machine <NUM> up the stairs. Meanwhile, the user can also assist by pulling on the handle <NUM> of the sewer cleaning device <NUM>. To transport the sewer cleaning device <NUM> down stairs, a user can control the second motor <NUM> to rotate the track <NUM> in the opposite direction.

With reference to <FIG>, the center of gravity Xc of the sewer cleaning machine <NUM> is positioned on the track <NUM> while the sewer cleaning machine <NUM> is at an angle relative to the ground (i.e., horizontal). In some embodiments, the angle of the sewer cleaning machine <NUM> is between approximately <NUM> and <NUM> degrees with the horizontal. In other embodiments, the angle of the sewer cleaning machine <NUM> is between approximately <NUM> and <NUM> degrees with the horizontal. In further embodiments, the angle of the sewer cleaning machine <NUM> is <NUM> degrees with the horizontal, which correlates with the standard US code for the angle of stairs. Positioning the center of gravity Xc on the treads reduces the possibility of the sewer cleaning machine <NUM> tipping if a user were to release the sewer cleaning machine <NUM> while climbing or descending stairs. In some embodiments, when the sewer cleaning machine <NUM> is tilted at an angle less than <NUM> degrees relative to the horizontal, the center of gravity Xc of the sewer cleaning machine may be above the tracks in a vertical direction. In a further embodiment, when the sewer cleaning machine <NUM> is tilted at an angle of less than <NUM> degrees, the center of gravity Xc is above the treads in a vertical direction.

In some embodiments, the sewer cleaning machine <NUM> includes a variable speed trigger that allows for stair climbing at a user selectable speed. In further embodiments, the sewer cleaning machine <NUM> is capable of detecting the direction the sewer cleaning machine <NUM> is traveling (e.g., through a sensor, (e.g., gyroscope, accelerometer, etc.), or through an input, (e.g., button actuation by a user)). In this embodiment, the controller will automatically set the max pulse width modulation PWM to a lower value (e.g., <NUM>% of max) and maps the range of the speed trigger pull over the remaining PWM range.

In some embodiments, the sewer cleaning machine <NUM> only includes one motor and a gearbox that is capable of shifting between rotating the drum <NUM> and operating the track <NUM>. In further embodiments, the motors <NUM>, <NUM> may include a bevel drive. In even further embodiments, the motors <NUM>, <NUM> are capable of handling high voltage. In alternate embodiments, the motors <NUM>, <NUM> offer audible feedback that communicate with the controller to indicate to a user if the cable has encountered debris within a drain.

In some embodiments, the sewer cleaning machine <NUM> may include soft-braking with external power resistors that communicate with the controller to achieve a desired brake rate of the drum (e.g., dynamic brake). In some embodiments, the sewer cleaning machine <NUM> may include a remote control that communicates with the controller using a wireless connection. The controller would be capable of sending feedback on location, security, job completion, etc. of the sewer cleaning device <NUM>. In further embodiments, the sewer cleaning machine <NUM> may include a rapid soft start, membrane switches, or backlit switches. In even further embodiments, the sewer cleaning machine <NUM> includes hall sensors to detect the position of the rotors of the motors <NUM>, <NUM>.

Although the invention is described with reference to discrete embodiments of the sewer cleaning machines, variations of the sewer cleaning machines exist within the scope of the claims.

Claim 1:
A sewer cleaning machine (<NUM>) comprising:
a frame (<NUM>);
a drum (<NUM>) rotatably supported by the frame, the drum having an opening (<NUM>);
a cable (<NUM>) positioned at least partially within the drum, the cable configured to be extended from and retracted into the drum through the opening; and
a cable feed device (<NUM>) supported by the frame adjacent the opening of the drum, the cable feed device including
a plurality of bearings (<NUM>) selectively engagable with the cable to feed the cable in or out of the drum,
a first lever (<NUM>) configured to move at least one of the plurality of bearings into engagement with the cable,
a second lever (<NUM>) configured to adjust at least one of the plurality of bearings between a forward feed orientation and a reverse feed orientation, and
a locking assembly (<NUM>) having a ratchet gear (<NUM>) and a pawl (<NUM>) engagable with the ratchet gear to selectively hold the at least one of the plurality of bearings in the forward feed orientation or the reverse feed orientation.