Backpack blower with improved starting mechanism

A starting assembly for a backpack blower may include a starting lever. The backpack blower may include an engine and a backpack harness configured to support the blower on a back of a user wearing the backpack harness. The starting lever may include a lever arm operably coupled to an axial member at a distal end of the axial member. The starting lever may be pivotable about an axis formed by the axial member by a user wearing the blower via the backpack harness to start the engine.

TECHNICAL FIELD

Example embodiments generally relate to outdoor power equipment and, more particularly, relate to a backpack blower with an improved starting mechanism.

BACKGROUND

Outdoor power equipment includes such devices as mowers, trimmers, edgers, chainsaws, blowers and the like. These devices are often used to perform tasks that inherently require the devices to be mobile. Accordingly, these devices are typically made to be relatively robust and capable of handling difficult work in hostile environments, while balancing the requirement for mobility.

Powering such devices could be accomplished in any number of ways. However, for outdoor power equipment that is intended to be carried by operators, petrol or gasoline engines are popular choices due to their power, range, and longevity. However, particularly for larger or more powerful engines, size and weight become important considerations. In this regard, for example, for blowers that are powered by gasoline or petrol engines it is common to place the blower on a backpack assembly so that the operator can carry the weight of the device on his/her back. This makes carrying the device much easier, and the blower tube is typically then able to be directed quite easily by the operator.

Although such backpack blower devices are very popular, those that are powered by gasoline or petrol engines have a distinct disadvantage when it comes to starting the engine. In this regard, engine starting is typically performed using a starter knob and recoil starter. The recoil starter includes a rope that is coiled on a reel and has the starter knob at a distal end of the rope. The operator pulls the starter knob and uncoils the rope. This uncoiling tensions a spring that is operably coupled to the reel, engages the clutch and turns the crank shaft to crank or start the engine.

This method of starting the engine (i.e., recoil starting) is very common, and is generally suggested to be accomplished while the blower is located on the ground. After the engine is started, the backpack may be put on the operators back and blowing operations may begin. For initial (cold) starting, the use of the recoil starter and starting before placing the blower on the operator's back may be both familiar, uncomplicated and not inconvenient. However, if the operator shuts down the blower for a short period of time (e.g., to reposition, to have a conversation or to take a short break), the use of a recoil starter may require removing the backpack before the blower can be restarted. This potential for repeated donning and doffing of the backpack to restart the blower can be very annoying and inefficient. Moreover, even if the operator could reach the recoil starter to attempt to start the engine with the backpack still donned, less than optimal results may be achieved. Thus, it may be desirable to develop an alternative starting method that could be performed without doffing the backpack.

BRIEF SUMMARY OF SOME EXAMPLES

Some example embodiments may therefore provide a relatively easy, convenient and effective starting mechanism that can be used without doffing the backpack.

In accordance with an example embodiment, a blower may be provided. The blower may include a housing, a backpack harness operably coupled to the housing to support the blower on a back of a user wearing the backpack harness, an engine operably coupled to the housing, a fan assembly operably coupled to the engine to force air through a blower tube responsive to operation of the engine, and a starting assembly comprising a starting lever that is pivotable by a user wearing the blower via the backpack harness to start the engine.

In another example embodiment, a starting assembly for a backpack blower may be provided. The starting assembly may include a starting lever. The backpack blower may include an engine and a backpack harness configured to support the blower on a back of a user wearing the backpack harness. The starting lever may include a lever arm operably coupled to an axial member at a distal end of the axial member. The starting lever may be pivotable about an axis formed by the axial member by a user wearing the blower via the backpack harness to start the engine.

DETAILED DESCRIPTION

Some example embodiments described herein provide an improved starting mechanism for a backpack blower. In this regard, some example embodiments may provide for the inclusion of a lever or other operable member that is easy to reach and operate while the blower remains on the back of the user. The user is therefore not required to doff the backpack blower before starting the engine. As a result, users may find operability of the backpack blower to be enhanced, and the user experience may also be improved.

FIG.1illustrates a perspective side view of a backpack blower (hereinafter simply referred to as blower100) in accordance with an example embodiment. Referring toFIG.1, the blower100may include a housing110inside which various components of the blower100are housed. The blower100may further include a engine120or power unit for providing the driving force to move air through the blower100. In this regard, the operation of the engine120may in turn power a fan assembly that drives air out of the blower100. In some embodiments, the power unit may be a gasoline or petrol engine that may be housed in the housing110. The housing110may be worn on the operator's back and supported via a backpack harness130.

The housing110may be formed of plastic, composite materials, metals or any other desirable materials. The backpack harness130may include shoulder straps and support structures that integrate with, provide a support platform for, or otherwise enable the weight of the housing110and the engine120to be carried by the backpack harness130while the user has donned the blower100. The user can slip the shoulder straps of the backpack harness130off in order to doff the blower100.

In an example embodiment, the blower100may further include a blower tube140that is operably coupled to the fan assembly via a flexible hose. Air driven through the fan assembly may be output into the hose and then be directable via the blower tube140by manual pointing of the blower tube140by the user. In some cases, the blower tube140may include a handle145that, in some cases, may include a trigger that may be operated by a finger of the user while the user holds the handle145. Actuation of the trigger may cause power from the engine120to turn the fan assembly and drive air through the blower100.

As discussed above, starting of the blower100would normally require doffing the blower100and placing the blower100on the ground while pulling a recoil starter. Example embodiments may replace the recoil starter with a starting mechanism (e.g., starting assembly200) of an example embodiment. The starting assembly200includes a starting lever210that is reachable and operable by the user while the user is still wearing the blower100on his/her back. Thus, for example, the starting lever210may have a structure that enables operation while the blower100is being worn.

When being worn, the blower100may be oriented so that the backpack harness130contacts a back of the user. For referential purposes, the user's back may be against a front of the blower100and the starting assembly200may generally be located at the back of the blower100. Forward and rearward directions may therefore be determined in relation to this reference guide. The front portion of the backpack harness130may therefore be relatively flat while resting against the back of the user while the blower100is being worn. Thus, for example, the front portion of the backpack harness130may define an interface plane at which the user's back is encountered. In some cases, the starting lever210may pass through the interface plane to be reachable by the user while the user has donned the blower100.

FIG.2illustrates a block diagram of the starting assembly200of an example embodiment, andFIG.3illustrates a block diagram of a slightly modified version of the starting assembly200′, which is configured for easier starting. Various components of the example ofFIG.2are shown inFIGS.4-9. In this regard,FIG.4illustrates a perspective view of various components of the starting assembly200with some housing portions removed by taking a cross section through various cover components to enable viewing access to certain components inside.FIG.5illustrates a shift in perspective relative toFIG.4, but is otherwise a cross section view taken along the same cross section plane fromFIG.4.FIG.6illustrates a perspective view of the starting lever210of an example embodiment.FIG.7illustrates a perspective view of a bull gear from a gear assembly of the starting assembly200.FIG.8illustrates a perspective view of a pinion gear of the gear assembly, andFIG.9(which includesFIGS.9A and9B) illustrates perspective views of a hub of the starting assembly.

As shown inFIGS.2and3, the gear assembly220is operably coupled to a ratcheting assembly240via a spring assembly230or230′. The spring assembly230or230′ and the ratcheting assembly240are then operably coupled to crank shaft250to start the engine120as described in greater detail below. The spring assembly230′ ofFIG.3may differ from that ofFIG.2in that the spring assembly230ofFIG.2may include materials for the spring and other components that are sufficient to store enough energy to overcome compression for starting the engine120without additional assistance. However, the spring assembly230may include a button or other release mechanism to continue to store energy in the spring of the spring assembly until the button or release mechanism is activated. Activation may release the spring and the spring may be sufficient to overcome compression and start the engine120.

Meanwhile, the spring assembly230′ ofFIG.3may incorporate an additional component or assembly (e.g., a compression release assembly260) that may be configured to assist in starting the engine120. The compression release assembly260may provide an “easy start” feature for the engine120, and may include, for example, a special cam that holds an engine valve open to avoid the need to overcome compression. The cam may be deactivated at the end of the rotation of the starting lever210so the engine120fires and then continues to run.

Referring now toFIGS.4-9, the starting lever210may include a lever handle or lever arm212that extends radially away from an axis formed by axial member214. A proximal end of the lever arm212may engage a distal end of the axial member214. Although shown inFIG.4to extend perpendicular to each other, the lever arm212and the axial member214need not necessarily form a right angle relative to each other. Moreover, in some cases, the lever arm212may be extendible or retractable so that the lever arm212only extends fully when positioned by the user for starting operations. For example, the lever arm212could telescopically extend or retract, or a portion of the lever arm212may be folded alternately (via a hinge) between an extended position (for starting operations) and a retracted position (for storage or during blower operation). In some cases, the lever arm212may not extend forward past the forward-most portions of the backpack harness130(or a plane thereof) when in the retracted position. However, the lever arm212may extend past the forward-most portions of the backpack harness130(or the plane thereof) when in the extended position.

As shown inFIGS.4-6, a proximal end of the axial member214may include a set of gear teeth provided as part of a bevel gear216. The bevel gear216provides the interface between the starting lever210and the gear assembly220. The gear assembly220may include a bull gear222shown in detail inFIG.7. The bull gear222includes a set of bevel gear teeth224that interface with the bevel gear216of the starting lever210. The bull gear222is operably coupled to a pinion gear226of the gear assembly220.

The pinion gear226, which is shown inFIG.8A, may include a ratchet interface228on an opposing side thereof, as shown inFIG.8B. The ratchet interface228may in turn interface with a spring holder232shown inFIGS.9A and9B. The ratchet interface228may include slots229via which pawls236(seeFIG.5) may interface with protrusions233located at an interior portion of a first annular projection235of the spring holder232. The pawls236and protrusions233may allow rotation of the spring holder232with the pinion gear226when moving in one direction (e.g., clockwise), but disengage to prevent any motion when moving in the opposite direction (e.g., counterclockwise). A second annular projection237of the spring holder232may include a spring anchor239to which the spring234of the spring assembly230is connected and anchored. The second annular projection237extends in an opposite direction with respect to the direction of extension of the first annular projection235and may have a smaller diameter than the first annular projection235.

A main shaft244may pass from the ratchet interface228through the spring holder232to a hub246shown inFIGS.10A and10B. In this regard, the hub246has a first side (shown inFIG.10A) that faces the spring holder232, and a second side (shown inFIG.10B) that faces a ratchet housing248. The hub246may interface with the ratchet housing248, which is operably coupled to the crank shaft250. The hub246may also interface with the spring holder232and the spring234(e.g., a clock spring), which may be disposed in a space located between the hub246and the spring holder232, and be anchored to each at opposing ends thereof. The spring holder232may include a one way bearing (e.g., provided by the interface between the pawls236and the protrusions233) so that the spring234can be would up in only one direction to store energy as described above. As the spring holder232is turned responsive to movement of the gear assembly220when the starting lever210is operated (i.e., pivoted about the axial member214) for starting, tension may be built up in the spring234and pawls236may engage the spring holder232(via protrusions233). Meanwhile, when the starting lever210is operated in the opposite direction to the normal direction achieved by pivoting the starting lever210, the spring holder232may not move. The tension continues to build up in the spring234during a single operation of the starting lever210or via multiple operations thereof until the tension accumulated overcomes compression for the engine120. At that point, the spring234unloads by spinning the hub246and the crank shaft250via operable coupling between the hub246and the ratchet housing248(e.g., via pawl249engaging one of the projections247on the second side of the hub246). The spinning of the crank shaft250then overcomes engine compression to start the engine120. Inertia created from spinning of the crank shaft250during operation then causes disengagement of the ratchet housing248from the hub246(e.g., by spring loaded disengagement of the pawl249due to the inertia of the spinning crank shaft250overcoming the force of the spring that loads the pawl249).

As noted above, rather than having to doff the blower100to restart the engine120, the user can simply pivot the starting lever210while still wearing the blower100. In the example ofFIG.1, if it is assumed that the user can reach the starting lever210with his/her left hand, then the user would quickly push the starting lever downwardly (i.e., in the direction of arrow300) one or more times. The starting lever210can also (if needed) be pivoted upward (i.e., in the direction opposite the direction of arrow300) to reset the starting lever210for another crank or start attempt. The rotation of the starting lever210causes the bull gear222to rotate (via engagement of the bevel gear216) with bevel gear teeth224of the bull gear222. The rotation of the bull gear222causes rotation of the pinion gear226, which rotation is coupled to the spring holder232via the ratchet interface228and the pawls236. Rotation of the spring holder232causes tensioning of the spring234(via one or more downward pivots of the starting lever210) until the hub246is ultimately turned due to sufficient spring pressure being built up (e.g., when compression of the engine120is overcome) to unload the spring234and start the engine120by turning the crank shaft250. Example embodiments may therefore allow the user to easily start the engine120without doffing the blower100and by instead using an intuitive motion that is easy to repeat while the blower100is donned.

A blower of an example embodiment may therefore include a housing, a backpack harness operably coupled to the housing to support the blower on a back of a user wearing the backpack harness, an engine operably coupled to the housing, a fan assembly operably coupled to the engine to force air through a blower tube responsive to operation of the engine, and a starting assembly comprising a starting lever that is pivotable by a user wearing the blower via the backpack harness to start the engine.

The blower of some embodiments may additional features, modifications, augmentations and/or the like to achieve further objectives or enhance operation of the blower. Similarly, the starting system described above may include additional features, modifications, augmentations and/or the like. The additional features, modifications, augmentations and/or the like may be added in any combination with each other. For example, in some examples, the starting lever may include a lever arm operably coupled to an axial member at a distal end of the axial member, the backpack harness may meet the back of the user at an interface plane, and the lever arm may extend through the interface plane. In some cases, the lever arm is extendible and retractable through the interface plane. In an example embodiment, the starting lever is configured to interface with a gear assembly. The gear assembly may be operably coupled to the spring assembly and a ratcheting assembly, and the spring assembly may be configured to accumulate tension responsive to rotation of the gear assembly in response to pivoting of the lever arm based on operation of the ratcheting assembly. The spring assembly may also be configured to release the accumulated tension to turn a crank shaft of the engine and start the engine. In some examples, the spring assembly may be configured to release the accumulated tension automatically in response to the accumulated tension exceeding compression of the engine. In an example embodiment, the spring assembly may be operably coupled to a compression release assembly configured to assist starting the engine based on the accumulated tension. In some cases, the starting lever may include a lever arm operably coupled to an axial member at a distal end of the axial member, and a bevel gear may be disposed at a proximal end of the axial member to interface with beveled teeth on a bull gear of the gear assembly. In an example embodiment, the bull gear may be operably coupled to a pinion gear having a ratchet interface operably coupled to a spring holder that rotates to cause the accumulated tension to build up in a spring of the spring assembly. In some cases, the spring holder may be operably coupled to a hub of the ratchet assembly configured to release the accumulated tension from the spring through the hub to turn the crank shaft in response to the accumulated tension exceeding compression of the engine. In an example embodiment, the spring holder may be configured to be driven by movement in a first direction responsive to operation of the lever arm and disengage from the lever arm responsive to movement of the lever arm in a second direction, and the hub may be configured to be disengaged from the crank shaft responsive to rotation of the crank shaft during operation of the blower.