Patent Description:
A breaker work tool or hammer work tool is commonly used in construction and mining operations to break rock boulders. The hammer can be mounted onto an excavator, backhoe, utility loader, or similar machine via a mounting bracket and is one of many possible work tool attachments, including augers, buckets, trenchers, and the like. During operation, high pressure fluid accelerates a tool member of the hammer, causing the tool member to strike, singularly or repeatedly, with great force. When the striking tool member contacts a rock boulder, impact energy is transferred thereto, creating a shockwave across the boulder and breaking it into smaller pieces.

Repeated impacts from the hammer tends to generate dust and particulate matter in the vicinity of the impact site, which can infiltrate the hammer, entangle with its machinery, and lower the service life of the tool. In many hammers, an exterior housing encloses and protects an internal power cell, while a detachable dust cover provides discretionary access to the power cell's components. When attached, the dust cover blocks dust and other matter from entering the housing; and, when detached, the dust cover enables access for maintenance and repair of internal machinery. Unfortunately, existing dust cover designs suffer from several flaws. For example, they are costly to manufacture, cumbersome, and difficult to assemble and disassemble, a process often requiring specialized tools or experience. Due to the latter reasons, many users are discouraged from servicing the power cell or from reinstalling the dust cover thereafter.

One example of prior art is found in Japanese Publication No. <CIT>, which discloses a bracket for installation of a hydraulic breaker attachment, the bracket comprising a detachable top plate. While the top plate of Fukui provides access to the internal machinery of the hydraulic breaker, the design may fail to properly protect the power cell from either dust or more powerful impacts. Moreover, similar to the state of the art, the top plate of Fukui is unwieldy during the installation process and not sturdy when fully installed. Accordingly, there remains a need in the art for a dust cover capable of shielding a hammer work tool against particulate matter while remaining reliable accessible and easv to install and uninstall. <CIT> discloses a hammer work tool.

<CIT> discloses a method for attaching a dust cover onto a hammer work tool.

According to the invention, there is provided a hammer work tool according to claim <NUM>. The hammer work tool includes a housing with a housing opening, a housing rim defining the housing opening, and a locking tab protruding from the housing rim; a power cell enclosed inside the housing and comprising a valve body and an accumulator; a tool member operatively associated with the power cell; and a dust cover. The dust cover further includes a plate having an interior surface, an exterior surface, and a perimeter; a plurality of interior ribs extending from the interior surface; a handle extending from the exterior surface; a groove circumscribing a majority of the perimeter; and a locking tab receiver. The groove is configured to receive the housing rim and the locking tab receiver is configured to receive the locking tab.

According to the invention, there is also provided a method for attaching a dust cover onto a hammer work tool according to claim <NUM>. The method includes the steps of providing a dust cover and a hammer work tool in accordance with any embodiment of the present disclosure; inserting a lower portion of a housing rim of the hammer work tool into a lower portion of a groove of the dust cover; inserting a locking tab of the hammer work tool into a locking tab receiver of the dust cover; and inserting an upper portion of the housing rim into an upper portion of the groove. The method is carried out by a single user without the use of additional tools.

These and other aspects and features of the present disclosure will be more readily understood after reading the following detailed description in conjunction with the accompanying drawings.

Referring now to the drawings and with specific reference to <FIG>, a work machine in accordance with the present disclosure is generally referred to by a reference numeral <NUM>. The work machine <NUM> may be a stationary machine or work vehicle designed for construction and earthwork operations, such the excavator shown, or can be any number of other work machines such as but not limited to front loaders, backhoes, bulldozers, mini-excavators, skid steers, and the like. A boom, lift arm, or combination thereof may be attached to the machine <NUM> at a proximate end and attached to a work tool <NUM> at a distal end, the boom or lift arm being configured to move and operatively control one or more functions of the work tool <NUM> through pneumatic, hydraulic, or other means. For many such machines <NUM>, the work tool <NUM> is detachably mounted and can be exchanged for another tool depending on the specific job at hand. Common work tool attachments in the art may include a hammer work tool <NUM> such as the one shown in <FIG>, but may also include other implementations such as but not limited to augers, backhoes, buckets, grapples, compactors, and the like. According to an embodiment of the disclosure, the work tool <NUM> comprises a dust cover <NUM> configured to prevent particulate matter from entering and potentially damaging the tool.

Turning now to <FIG>, a detailed perspective view of the hammer work tool <NUM> from <FIG> is provided. The hammer work tool <NUM> includes a housing <NUM>, a power cell <NUM> enclosed inside the housing <NUM>, and a tool member <NUM> operatively associated with the power cell <NUM>. The power cell <NUM>, which generates the operating force of the tool member <NUM>, further includes a valve body and an accumulator, and may also include a front head, cylinder, piston, and one or more tie rods (not shown). In one embodiment, a spray nozzle <NUM> attached to the housing <NUM> and directed near a point of impact of the tool member <NUM> provides dust suppression during the hammer's <NUM> breaking action. And in another embodiment, the hammer work tool <NUM> is operatively connected to the work machine <NUM> through a mounting bracket <NUM>. While a hammer attachment is shown, it should be understood that the hammer work tool <NUM> may also be an independent tool, such as a standalone jackhammer or a pavement breaker.

The housing <NUM> of the hammer work tool <NUM> may further comprise a housing opening <NUM> providing access to the power cell <NUM>, a housing rim <NUM> defining the housing opening <NUM>, a locking tab <NUM> protruding from the housing rim <NUM> and, in some embodiments, a second, non-locking tab <NUM> protruding from the housing rim <NUM>. However, as seen in <FIG>, a dust cover <NUM> is removably attached to the hammer work tool <NUM> and fully covers the housing opening <NUM>. Accordingly, the dust cover <NUM> may be substantially similar in size and shape to that of the opening <NUM>. When the dust cover <NUM> is detached, the opening <NUM> provides access to at least the valve body and the accumulator of the power cell <NUM>; and, when attached, the dust cover <NUM> blocks the opening <NUM> and prevents particulate matter from entering the housing <NUM>. In an embodiment, the cover <NUM> further protects the hammer work tool <NUM> from higher energy impacts or projectiles that could be created during the breaking action. And in another embodiment, the cover <NUM> and the seal between the cover <NUM> and the housing <NUM> may be water-resistant or even water-proof, such that the hammer <NUM> is also protected against liquid incursions.

Turning now to <FIG>, a detailed perspective view of the dust cover <NUM> according to an embodiment of the present disclosure is shown. The dust cover <NUM> includes a plate having a predominantly arcuate and planar shape, with a length L and width W significantly greater than its thickness T. An exterior surface <NUM> faces the convex side of the cover <NUM> and the outside of the hammer work tool <NUM> when installed; an interior surface <NUM> faces the concave side of the cover <NUM> and the inside of the hammer work tool <NUM> when installed; and a perimeter <NUM> encircles the cover <NUM>. The cover <NUM> may be substantially symmetrical lengthwise (across a bisecting plane perpendicular to the width W), although important discrepancies may exist in some or all embodiments. In an embodiment, the cover <NUM> has a thickness of between <NUM> and <NUM>, preferably between <NUM> and <NUM>, and even more preferably <NUM>.

In an embodiment, the cover <NUM> may further include a rectilinear shelf <NUM> located at an upper end of the cover <NUM> with a circular channel <NUM> connecting the exterior surface <NUM> to the interior surface <NUM>. The circular channel <NUM> may be radiused to allow a hose associated with the hammer work tool <NUM> to pass through, for instance, to supply a pressurized working fluid (not shown). The channel <NUM> radius may be equal to or greater than the radius of the hose and designs with multiple channels <NUM> fitted for multiple hoses are also contemplated.

In another embodiment, a wire <NUM> is fully enclosed inside the dust cover <NUM> and provides structural support to the dust cover <NUM>. The wire <NUM> is preferably a steel wire, such as a carbon steel or low alloy steel commonly used in reinforcement applications, but other materials and composites may also be employed. Moreover, the wire <NUM> may be configured in any size, shape or orientation within the cover <NUM>, may be a singular wire or a plurality of wires, or may be configured as a mesh, such as a planar mesh or a three-dimensional mesh.

With continued reference to <FIG>, a handle <NUM> extends from the exterior surface <NUM> and may be any type or shape of handle suitable for grasping by one or both hands of a user. In addition, one or more exterior ribs <NUM> may be raised from the exterior surface <NUM> and provide structural support to the cover <NUM>. The handle <NUM> and the one or more exterior ribs <NUM> may be symmetrically centered across the bisecting plane and may be spaced evenly apart. In some embodiments, one of the exterior ribs <NUM> doubles as the handle <NUM> (e.g. acts as both an exterior rib <NUM> and a handle <NUM>) or vice versa, or multiple exterior ribs <NUM> double as multiple handles <NUM> or vice versa.

Turning now to <FIG>, the rear side and interior surface <NUM> of the cover <NUM> are shown in detail. A plurality of interior ribs <NUM> are raised from the interior surface <NUM> and provide structural support to the dust cover <NUM>. The plurality of interior ribs <NUM> may be arranged substantially symmetrically across the bisecting plane, with a single, center rib <NUM> running lengthwise and side ribs <NUM> extending outwards and spaced at regular intervals. It should be noted that the interior ribbing <NUM> may not be present in the vicinity of a locking tab receiver <NUM> associated with a locking mechanism of the cover <NUM>. Moreover, the arrangement of the interior ribs <NUM> may conform to the shape of the work tool to which the cover <NUM> is attached and, especially, to the shape of an internal machinery of the work tool, where said internal machinery may or may not abut against the interior surface <NUM>. Furthermore, while a center rib <NUM> and side ribs <NUM> are shown, other configurations are also contemplated and the number and arrangement of the plurality of interior ribs <NUM>, as well as the size and shape of each individual rib <NUM>, may be chosen according to specific applicational requirements. In an embodiment, each interior rib <NUM> has filleted edges and a thickness of between <NUM> and <NUM> square, preferably between <NUM> and <NUM> square, and even more preferably <NUM> square.

In an embodiment, the dust cover <NUM> is manufactured using compression molding techniques and may be made from any number of compression moldable materials, including thermoset resins, thermoplastics, polyimide-based plastics, and others. Some or all of the components of the cover <NUM>, including the handle <NUM>, exterior ribs <NUM> and interior ribs <NUM>, may be formed in the same molding process or may be installed separately afterwards using various techniques known in the art. With all components included, the dust cover <NUM> may have a total weight of between <NUM> and <NUM>, preferably between <NUM> and <NUM>, and even more preferably <NUM>.

The locking mechanism whereby the cover <NUM> is attached to the hammer work tool <NUM> is best described in conjunction with <FIG>. <FIG> shows a transparent front view of a dust cover <NUM> attached to a hammer work tool <NUM> in accordance with the present disclosure. <FIG> is a cutaway view of the dust cover <NUM> and the hammer work tool <NUM> shown in <FIG> and <FIG> is a sectional view along a cutting plane <NUM>-<NUM> of the same. As seen in <FIG>, a groove <NUM> circumscribes a majority of the perimeter <NUM> of the dust cover <NUM>, with the exception of the rectilinear shelf <NUM> and recesses <NUM>. The groove <NUM> may further include an interior tab <NUM> proximal to the interior surface <NUM>, an exterior tab <NUM> proximal to the exterior surface <NUM>, and a valley <NUM> formed between the interior tab <NUM> and the exterior tab <NUM>. The recesses <NUM> may be defined by a segment of the perimeter <NUM> on which the exterior tab <NUM> and valley <NUM> are recessed, but on which the interior tab <NUM> is unaffected. Accordingly, no groove <NUM> can be formed therein. Moreover, the recesses <NUM> may divide the groove <NUM> into a lower portion, located lengthwise below the recesses <NUM>, and an upper portion, located lengthwise above the recesses <NUM>. The dust cover <NUM> also includes a locking tab receiver <NUM>, with may be an aperture perpendicular to the width dimension W and, in some embodiments, located in one of the recesses <NUM>.

As shown in <FIG>, the housing rim <NUM> of the housing <NUM> is configured to closely fit into the groove <NUM> of the dust cover <NUM> when installed, such that little to no movement is allowed between the two components. More specifically, the interior tab <NUM> may be configured to abut an inside of the housing rim <NUM> and the exterior tab <NUM> configured to abut an outside of the housing rim <NUM>. The overlap between either tab <NUM>, <NUM> and the housing rim <NUM> thereby prevents detachment of the cover <NUM> when there is no external user intervention. In an embodiment, the interior tab <NUM> may be longer than the exterior tab <NUM>. And in another embodiment, the interior tab <NUM> further comprises an entry chamfer <NUM>, which may be distal to the valley <NUM> and reduces the force necessary during an attachment procedure.

Turning now to <FIG>, the locking tab receiver <NUM> of the dust cover <NUM> is shown with greater clarity. The locking tab receiver <NUM>, which may be an aperture of the cover <NUM> perpendicular to the width dimension W, is configured to receive the locking tab <NUM> of the housing <NUM>. Furthermore, when fully installed, the locking tab <NUM> may penetrate and closely fit inside the locking tab receiver <NUM>, such that the cover <NUM> is restricted in all degrees of motion. In an embodiment where the locking tab receiver <NUM> is located in one of the recesses <NUM>, the locking tab <NUM> may also insert into the recess <NUM> with varying levels of tolerance. And in another embodiment, the non-locking tab <NUM> of the housing <NUM> may insert into a separate recess <NUM> opposite that accommodating the locking tab receiver <NUM>, further securing the cover <NUM> in place.

Referring back to <FIG>, on the interior surface <NUM> of the cover <NUM>, the plurality of interior ribs <NUM> may be suspended near the vicinity of the locking tab receiver <NUM> to allow space for the locking tab <NUM> after installation. Moreover, the size of the locking tab receiver <NUM> and the vacancy provided by the interior ribs <NUM> may be similar or identical to the dimensions of the locking tab <NUM>; or the size and shape of the locking tab <NUM> may be configured to closely fit into the locking tab receiver <NUM> and the vacancy formed by the interior ribs <NUM>. In short, the design of the two, interlocking components may be complementary. In an embodiment, the locking tab receiver <NUM> may be alternatively placed on an opposite side of the dust cover <NUM> or on both sides of the dust cover <NUM>, and the locking tab <NUM> moved or doubled accordingly.

It should be understood that the design of the cover <NUM> prevents attachment and detachment from the hammer <NUM> without external human intervention. However, the cover <NUM> and, optionally, the housing rim <NUM> are flexible enough to allow a single user to install and uninstall the cover <NUM> from the housing <NUM> with little effort and without the use of additional tools.

The present disclosure may find industrial applicability in any number of hammer work tools and work tool attachments where it is desirable to shield the internal components of the work tool from particulate matter. The work tool may be one capable of operating independently, for example a standalone jackhammer, digger, rock drill, pavement breaker, rivet buster, or the like; or it may be an attachment on a larger work machine such as the one shown in <FIG>, for example an excavator, mini-excavator, backhoe, skid steer, utility loader, or the like.

Many of these tools operate in construction and mining environments heavily exposed to dust and debris. Consequently, the dust cover <NUM> prevents entry of particulate matter into the machine while also providing access to internal components for maintenance and repairs. By refining the locking mechanism, structural engineering and ergonomics of the dust cover <NUM>, the present disclosure simplifies the attachment/detachment process without sacrificing functionality. Users can more easily manipulate the dust cover <NUM> without the use of additional tools and the dust cover <NUM> can provide a same or greater level of reliability and strength. From a manufacturing standpoint, the dust cover <NUM> of the present disclosure requires cheaper tooling costs and thus cheaper production costs, especially at low volume.

In general, exposure to dust is particularly prevalent when it comes to hammer work tools <NUM>. Consequently, the effects of dust may be more detrimental and the design of the dust cover <NUM> more impactful. More specifically, the dust cover <NUM> is installed onto a housing <NUM> of the hammer <NUM> so as to protect a power cell <NUM> enclosed inside.

An exemplary installation process is outlined in <FIG>, wherein a method of attaching a dust cover <NUM> onto a hammer work tool <NUM> in accordance with the present disclosure is generally referred to by a reference numeral <NUM>. In a first step <NUM>, a hammer work tool <NUM> and a dust cover <NUM> according to any of the foregoing embodiments are provided. In a second step <NUM>, a lower portion of the housing rim <NUM> is inserted into a lower portion of the groove <NUM>, which may be the portion of the groove <NUM> lengthwise below the recesses <NUM>. Consequently, the interior tab <NUM> may abut the inside of the housing rim <NUM> and the exterior tab <NUM> may abut the outside of the housing rim <NUM>. In a third step <NUM>, the locking tab <NUM> of the housing <NUM> is inserted into the locking tab receiver <NUM> of the cover <NUM>. In some embodiments, the locking tab <NUM> is received by both the locking tab receiver <NUM> and one of the recesses <NUM>, and the non-locking tab <NUM> is received by a separate recess <NUM>. In a fourth step <NUM>, an upper portion of the housing rim <NUM> is inserted into the upper portion of the groove <NUM>. Specifically, the portion of the groove <NUM> above the recesses <NUM> and thus far unattached is now inserted, thereby completely installing the cover <NUM> onto the hammer work tool <NUM>.

It is worth mentioning that any and all of the foregoing procedure is carried out by a single user without the use of additional tools. Moreover, it should be understood that some or all of the steps may require the user to bend, squeeze, push, pull, twist or otherwise manipulate either the cover <NUM> or the housing <NUM> to properly affix the two components. The steps of method <NUM> may be executed in a different order from those delineated or additional steps may be included, so long as the dust cover <NUM> is securely installed onto the hammer work tool <NUM>. Lastly, in some embodiments, the steps of method <NUM> may be reversed and negated in a parallel detachment process.

Claim 1:
A hammer work tool (<NUM>), comprising:
a housing (<NUM>) having a housing opening (<NUM>), a housing rim (<NUM>) defining the housing opening (<NUM>), and a locking tab (<NUM>) protruding from the housing rim (<NUM>);
a power cell (<NUM>) enclosed inside the housing (<NUM>), the power cell (<NUM>) including a valve body and an accumulator;
a tool member (<NUM>) operatively associated with the power cell (<NUM>); and
a dust cover (<NUM>),
characterised in that the dust cover (<NUM>) further comprises:
a plate having an interior surface (<NUM>), an exterior surface (<NUM>), and a perimeter (<NUM>);
a plurality of interior ribs (<NUM>) extending from the interior surface (<NUM>);
a handle (<NUM>) extending from the exterior surface (<NUM>);
a groove (<NUM>) circumscribing a majority of the perimeter (<NUM>); and
a locking tab receiver (<NUM>);
wherein the groove (<NUM>) is configured to receive the housing rim (<NUM>) and the locking tab receiver (<NUM>) is configured to receive the locking tab (<NUM>).