Patent Description:
Sprayers can be used to pump paint and/or other solutions such as water, oil, and solvents, among other solutions. These sprayers include a pump drive coupled to a pump assembly and enclosed by a housing and a front cover. The pump drive converts the motion produced by a motor to pumping motion. For example, pump drives typically convert rotary motion of a motor to reciprocating motion of a pump. In conventional sprayers, the only way to gain access to the pump assembly is to remove the front cover, which cooperates with structural features of the housing to support the pump drive components. Therefore, in order to service the pump, many components not needing service, such as components of the pump drive, are removed or at least exposed in order to gain access to the pump and/or release the pump assembly from the sprayer.

Because of the aforementioned issues, a need exists for a sprayer assembly that permits the pump assembly to be readily removed without disassembling and exposing components not in need of service, such as the pump drive.

<CIT> discloses an airless spray pump provided with a single-acting piston pump which allows the use of a low-cost yoke drive. The motor and pump shaft are offset for efficient force utilization This document does not disclose an end bell in the form of a plate and a door attached to the cover moveable between an open position and a closed position, wherein the door blocks the pump assembly from being removed from the end bell while in the closed position but permits the pump assembly to be removed from the end bell while in the open position.

A paint sprayer according to the invention is defined in claim <NUM>.

Embodiments described by the present disclosure make it easy to release a pump assembly, and thereby service a pump, via a door without disassembly of the sprayer housing and/or front cover which typically encloses an open end of the housing. Leaving the structural components of the sprayer in place permits components of the pump drive (e.

, gears, cranks, an eccentric element, a yoke, and/or various other components) to remain assembled and protected by the housing and front cover of the sprayer. These and other aspects are further discussed herein.

<FIG> is a perspective view of sprayer <NUM> used to dispense a solution, for example paint, through a handheld gun and hose assembly (not shown). Sprayer <NUM> is attached to frame <NUM> via shelf <NUM>. Frame <NUM> includes wheels <NUM> and legs <NUM> to facilitate support and manual transportation of sprayer <NUM>.

Sprayer <NUM> includes end bell <NUM>, motor housing <NUM>, front cover <NUM>, and door <NUM> that together form enclosure <NUM> housing components of sprayer <NUM> such as motor <NUM> (shown schematically in <FIG>) and components of the pump drive, which is described in further detail with respect to <FIG> and <FIG>. End bell <NUM> is a structural component that supports motor housing <NUM> and front cover <NUM> in addition to providing a mounting point for sprayer <NUM> to shelf <NUM>. For example, front cover <NUM> can be secured to end bell <NUM> with a plurality of screws which extend through front cover <NUM> and screw into end bell <NUM>. A similar attachment method can be used to affix motor housing <NUM> to end bell <NUM> and to affix end bell <NUM> to frame <NUM> via shelf <NUM>. End bell <NUM> also supports motor <NUM> disposed within motor housing <NUM> and at least partially supports the pump drive disposed on an opposite side of end bell <NUM> from motor <NUM> and arranged between front cover <NUM> and end bell <NUM>.

For example, end bell <NUM> can be a plate having first side 12a and second side 12b that is opposite first side 12a. Motor <NUM> and motor housing <NUM> are disposed on and are supported from first side 12a of end bell <NUM>. The pump assembly24 and associated pump drive are supported from second side 12b of end bell <NUM>. End bell <NUM> is connected to frame <NUM> via shelf <NUM>. Alternatively, end bell <NUM> can be a portion of a support frame (e.g., frame <NUM>) that is structurally fixed (i.e., restrained with respect to ground) while utilizing the features of end bell <NUM> described above.

Pump assembly <NUM> is partially or fully contained within enclosure <NUM>, and in <FIG> is shown protruding from enclosure <NUM>. Pump assembly <NUM> includes pressure control <NUM> and prime control <NUM>, however it is noted that not all embodiments of pump assembly <NUM> include pressure control <NUM> and/or prime control <NUM>. When pressure control <NUM> and prime control <NUM> are integrated into pump assembly <NUM>, pressure control <NUM> and prime control <NUM> control pressure regulation and priming of the pump of sprayer <NUM>, respectively. Pressure control <NUM> can be an electrically-driven control containing a sensor that is sensitive to the paint pressure generated by the pump, a user input for setting the paint pressure (e.g., a rotating knob connected to a potentiometer), or a circuit for closed loop pressure regulation based on the sensor and the setting of the user input. The circuit may control motor <NUM> within motor housing <NUM> to regulate pressure, such as by switching motor <NUM> on and off. Sprayer <NUM> further includes intake hose <NUM> for drawing paint out of a reservoir (not shown). The paint travels through a pump contained at least partially within pump assembly <NUM> and out of a hose and gun assembly (not shown) attached to outlet <NUM> as is known in the art.

Door <NUM> is moveably attached to front cover <NUM>. Door <NUM> can be formed from a metal or polymer, and front cover <NUM> can be formed as a unitary piece of metal. As will be explained further herein, front cover <NUM> partially contains, covers, supports, and/or protects various components of the pump drive (e.g., gears, a crank, an eccentric element, and/or a yoke), which convert the rotational output motion of motor <NUM> to linear reciprocating motion that drives the pump.

In conventional sprayers, the only way to gain access to all pump components and/or remove pump assembly <NUM> is to remove front cover <NUM>. However, in such conventional sprayers, front cover <NUM> structurally supports the pump drive components. Therefore, in order to service the pump, many components not needing service, such as the pump drive components, are removed or at least exposed in order to gain access to the pump and/or release pump assembly <NUM>. However, embodiments of the present disclosure make it easy to release pump assembly <NUM> (and thereby service the pump) via door <NUM> without removal of front cover <NUM>. For example, when door <NUM> is in an open position, pump assembly <NUM> can be removed while leaving front cover <NUM> in place which leaves the pump drive components in place while the pump is serviced. Furthermore, when door <NUM> is in a closed and locked position, door <NUM> retains pump assembly <NUM> against end bell <NUM>, thus facilitating assembly and disassembly of pump assembly <NUM> without using tools. These and other aspects are further discussed herein.

<FIG> are detailed perspective views of front cover <NUM>, door <NUM>, and pump assembly <NUM> of sprayer <NUM>. <FIG> show the progression of opening door <NUM>. Specifically, <FIG> shows door <NUM> in a locked position, sometimes referred to as a closed position. <FIG> shows door <NUM> in an unlocked position. <FIG> shows door <NUM> in an open position exposing enclosure interior <NUM> and electrical connector part <NUM>. As demonstrated by <FIG>, door <NUM> opens by a sequential sliding-pivoting action explained as follows. First, sliding door <NUM> in direction <NUM> and within track <NUM> (not referenced by <FIG>) translates door <NUM> from the locked position in <FIG> to the unlocked position in <FIG>. Direction <NUM> is substantially parallel with track <NUM> (not referenced in <FIG>) and corresponds to the direction door <NUM> translates between the locked position and the unlocked position (see <FIG> and <FIG>). As shown in <FIG>, direction <NUM> is generally upwards. Although, direction <NUM> can be downwards, sideways, or another direction for other embodiments of door <NUM> and front cover <NUM>. Track <NUM> (not referenced in <FIG>) limits door <NUM> to a linear sliding motion and prevents pivoting motion until door <NUM> is fully slid into the unlocked position of <FIG>. Second, door <NUM> can pivot to transition from the unlocked position shown in <FIG> to the open position shown in <FIG>, exposing enclosure interior <NUM> and fully exposing pump assembly <NUM>. Thus, door <NUM> moves from the locked or closed position to the open position by sequential linear slide and pivot motions. To close door <NUM>, the reverse process can be used. First, door <NUM> pivots from the open position in <FIG> to the unlocked position in <FIG>. Second, door <NUM> slides in a direction opposite direction <NUM> from the unlocked position in <FIG> to the locked position in <FIG>. Thus, door <NUM> moves from the open to the closed or locked positions by sequential pivot and linear slide motions. Once door <NUM> is in the locked position, at least a portion of door <NUM> engages and/or blocks pump assembly <NUM> to prevent translation of pump assembly <NUM> in a direction away from end bell <NUM>. Details of door <NUM> and front cover <NUM> that facilitate the sliding and pivoting motion are discussed below.

<FIG> is an exploded view showing features of front cover <NUM> that interface with door <NUM> as viewed from the interior of sprayer <NUM>. Front cover <NUM> includes opening <NUM> that extends through front cover <NUM> from exterior side <NUM> to interior side <NUM> of front cover <NUM>. In <FIG>, opening <NUM> is generally T-shaped and has the widest portion of the T positioned along a side of front plate <NUM>. Other embodiments can have different sizes, shapes, and positions of opening <NUM> in which the details are selected based on the desired access to enclosure interior <NUM>. Track <NUM> extends along opening <NUM> from first end <NUM> to second end <NUM> and includes channel <NUM>. In the <FIG> embodiment, track <NUM> does not extend along the entire extent of opening <NUM>, although other embodiments can include a track of this type.

Channel <NUM> forms a recess within front cover <NUM> that extends from second end <NUM> towards first end <NUM> and opens towards interior side <NUM> of front cover <NUM>. Although channel <NUM> can extend the entire length of track <NUM> from second end <NUM> to first end <NUM> in some embodiments, here channel <NUM> extends a partial distance towards first end <NUM> as shown in <FIG>. A partially-extending channel <NUM> retains the door within track <NUM>. For example, the ends of channel <NUM> can be used to prevent excessive translation of door <NUM> beyond first end <NUM> and second end <NUM>. Moreover, a portion of end bell <NUM> prevents door <NUM> from disengaging channel <NUM> in a direction generally perpendicular to track <NUM>. With this arrangement, door <NUM> is coupled to front cover <NUM>.

Track <NUM> can further include guiding surface <NUM> that extends from first end <NUM> to pivot bore <NUM> at or near second end <NUM>. Guiding surface <NUM> is a flat face positioned between channel <NUM> and opening <NUM> and, as will be described below, abuts a mating face of door <NUM>. Pivot bore <NUM> extends from channel <NUM> to opening <NUM> and has a cylindrical surface orientated to surround a pivoting portion of door <NUM> when it is in the unlocked and open positions. As configured, pivot bore <NUM> permits door <NUM> to pivot from the unlocked position to an open position and vice versa. Furthermore, a surface of door <NUM> abutting guiding surface <NUM> prevents rotation of door <NUM> along track <NUM> from the locked position (closed position) at first end <NUM> to a location near second end <NUM> where guiding surface <NUM> is adjacent pivot bore <NUM>.

Front cover <NUM> can include one or both of catch <NUM> and locking surface <NUM> to restrain door <NUM> in the locked position. Generally, catch <NUM> and locking surface <NUM> form lips protruding into portions of opening <NUM> that are adapted to interface with latch <NUM> and tab <NUM> of door <NUM>, respectively. Catch <NUM> interfaces with door <NUM> at inward-facing surface 54a (i.e., facing towards end bell <NUM> and enclosure interior <NUM>) while locking surface <NUM> is also inward-facing to engage tab <NUM> of door <NUM>. Catch <NUM> has width W that is perpendicular to a translation direction (i.e., direction <NUM>) of door <NUM> and length L that is parallel to a translation direction of door <NUM>, each being selected to interface with corresponding portions of door <NUM>. Length L is less than a distance door <NUM> translates along track <NUM> from the locked position depicted in <FIG> to the unlocked position depicted in <FIG> to permit door <NUM> to disengage catch <NUM>. In order to restrain an outward force imposed by door <NUM> on front cover <NUM> in the locked position, width W and length L are also selected based on shear and bending stresses calculated within catch <NUM> as is known in the art. Locking surface <NUM> mates with door <NUM> to restrain translation of door <NUM> from the locked position to the unlocked position as will be further explained in reference to tab <NUM> below.

Door <NUM> is adapted to be placed within opening <NUM> and, therefore, has a complimentary shape. More specifically, door <NUM> includes interior side <NUM> that faces towards enclosure interior <NUM> in the locked position and exterior side <NUM> facing in an opposite, outward direction. Side faces 64a-h extend from interior side <NUM> to exterior side <NUM> to define a body of door <NUM> and through which pivot axis P extends. Pivot axis P extends through door <NUM> adjacent to side face 64a which is adapted to interface with pivot bore <NUM> at second end <NUM> of track <NUM>.

Door <NUM> further includes one or more trunnions <NUM> that can extend from one or more opposite side faces of door <NUM> that face track <NUM> in the locked and unlocked positions (e.g., side faces 64b and <NUM>). In some embodiments, trunnion <NUM> includes cylindrical portion 66a and cuboidal portion 66b that extend along pivot axis P. Cylindrical portion 66a is adapted to be received by channel <NUM> of front cover <NUM> while at least a surface of cuboidal portion 66b is adapted to abut guiding face <NUM> of front cover <NUM> in the locked and intermediate positions between the locked and unlocked positions. When door <NUM> is in the unlocked and open positions, pivot bore <NUM> surrounds cuboidal portion 66b to permit door <NUM> to rotate about pivot axis P. Trunnion <NUM> of some embodiments extends along and forms a side face of door <NUM> adapted to mate with second end <NUM> of track <NUM> (e.g., side face 64a). With such a configuration, cuboidal portion 66b extends between cylindrical portions 66a disposed at opposing ends of cuboidal portion 66b, each cylindrical portion 66a received by channels <NUM> disposed on opposite sides of opening <NUM>. Because cylindrical portions 66a are restrained within channels <NUM> of front plate <NUM>, door <NUM> is prevented from excessive side-to-side displacement (i.e., in a direction generally perpendicular and in the same plane as translation of door <NUM> along track <NUM>. Alternatively, door <NUM> can have the opposite trunnion configuration in which trunnion <NUM> has cylindrical portion 66a disposed between cuboidal portions 66b placed on opposing sides of door <NUM>. Moreover, instead of cuboidal portion 66b, door <NUM> can include a flat surface formed by removing material from a portion of cylindrical portion 66a that engages guiding surface <NUM>. In each embodiment of trunnion <NUM>, door <NUM> is restrained by mating surfaces of trunnion <NUM> and track <NUM>.

Door <NUM> can further include latch <NUM> formed by or protruding from at least one side face 66a-h. For example, latch <NUM> can be formed by side faces 64d and 64f of door <NUM>, where each of side faces 64d and 64f is positioned to face catch <NUM> of front panel <NUM>. Latch <NUM> has surface 58a that faces towards exterior side <NUM> and, thus, faces away from enclosure interior <NUM> in the locked position. Furthermore, surface 58a is adapted to abut inward facing catch surface 54a by having complimentary shapes and sizes that engage in the closed position. Latch <NUM> can include one or more ribs <NUM> extending from latch <NUM> towards interior side <NUM> of door <NUM> to increase the strength of latch <NUM> in bending.

Door <NUM> can include a locking mechanism to limit sliding of door <NUM> from the locked position. For example, tab <NUM> can be configured within a cutout extending through door <NUM> from interior side <NUM> to exterior side <NUM>. In this example, tab <NUM> is affixed to door <NUM> within the cutout at attachment end 72a and is unrestrained by door <NUM> at engagement end 72b, which extends beyond side face <NUM> of door <NUM>. Lip <NUM> projects from tab <NUM> between attachment end 72a and engagement end 72b and interfaces with locking surface <NUM> in front cover <NUM> (or alternatively lip <NUM> can project from locking surface <NUM> to engage a surface of tab <NUM>) in a locking manner. To slide door <NUM> from the locked position in <FIG> to the unlocked position in <FIG>, tab <NUM> disengages lip <NUM> from locking surface <NUM> and allows the sliding motion of door <NUM> along track <NUM>. To disengage lip <NUM> from locking surface <NUM>, tab <NUM> is lifted away from the front cover <NUM> by applying a force to engagement end 72b, whereas tab <NUM> is otherwise biased toward front cover <NUM> to keep lip <NUM> and locking surface <NUM> engaged. Some embodiments of tab <NUM> have an undeflected shape that interferes with locking surface <NUM> in the locked position of door <NUM>. By deflecting tab <NUM> in this manner, a restoring moment acts on tab <NUM> about attachment end 72a to bias tab <NUM> towards front plate <NUM> when door <NUM> is in the locked position. Moreover, door <NUM> can include one or more tabs <NUM> to restrain door <NUM> in the locked position. For example, the embodiment depicted by <FIG> includes two tabs <NUM> positioned on opposite sides of door <NUM>, each tab engaging locking surface <NUM> of front cover <NUM>.

<FIG> is a perspective view of front cover <NUM> and door <NUM> in the locked position as viewed from interior side <NUM> of front cover <NUM>. In the locked position, cylindrical portion 66a of trunnion <NUM> is received within channel <NUM> of front cover <NUM> and a face of cuboidal portion 66b abuts guiding surface <NUM>. The surface of cuboidal portion 66b that abuts guiding surface <NUM> resists rotation of door <NUM> about pivot axis P. Additionally, lip <NUM> of tab <NUM> engages locking surface <NUM> and thereby restrains translation of door <NUM> from first end <NUM> towards second end <NUM> of track <NUM>. When, catch <NUM> and latch <NUM> are engaged, mating surfaces 54a and 58a (see <FIG>) further restrain rotation of door <NUM> about pivot axis P.

<FIG> is a perspective view of front cover <NUM> and door <NUM> in the locked position as viewed from exterior side <NUM> of front cover <NUM>. Because door <NUM> is in the locked position, tabs <NUM> are engaged with locking surface <NUM> (see <FIG> and <FIG>). To extend the life of tabs <NUM> and to facilitate disengagement of tabs <NUM> from locking surface <NUM>, tabs <NUM> include thickened portion <NUM> at attachment end 72a. Because tabs <NUM> are disengaged from front cover <NUM> by applying a force to engagement end 72b and thereby displacing engagement end 72b away from front cover <NUM>, bending stress is imposed on tab <NUM> at attachment end 72a. Thickened portion <NUM> increases a nominal thickness of tab <NUM> at attachment end 72a which in turn tends to reduce bending stress at attachment end 72a.

Front cover <NUM> and door <NUM> can optionally include features for restraining rotation of door <NUM> about pivot axis P when door <NUM> is in the open position. For example, door <NUM> can include one or more grooves <NUM> that extend from exterior side <NUM> to interior side <NUM> of door <NUM> and transverse to a lengthwise direction of side surface 64a, a surface that forms a portion of trunnion <NUM>. As shown in <FIG>, a cross-sectional view taken along line <NUM>-<NUM>, surface 78a of each groove <NUM> is contoured to mate with a complimentary contour of one or more protuberances <NUM> (shown schematically) of front plate <NUM>. Protuberances <NUM> protrude from auxiliary plate <NUM>, and auxiliary plate <NUM> extends from interior side <NUM> (see <FIG>) of front plate <NUM>. When door <NUM> is positioned within opening <NUM> in the closed position, auxiliary plate <NUM> also extends along interior side <NUM> of door <NUM>. Accordingly, when door <NUM> is translated to the unlocked position (i.e., upwards relative to front plate <NUM> as shown in <FIG>) and subsequently rotated about pivot axis P into the open position, surface 78a of groove <NUM> engages protuberance <NUM> and thereby holds door <NUM> in the open position by restraining rotation of door <NUM> about pivot axis P.

<FIG> is a cross sectional view of tab <NUM> taken along line <NUM>-<NUM> in <FIG> when door <NUM> is in the locked position. With door <NUM> in the locked position, lip <NUM> protrudes from tab <NUM> to engage locking surface <NUM> of front plate <NUM>. Because tab <NUM> is affixed to door <NUM> at attachment end 72a and unrestrained by door <NUM> at engagement end 72b, tab <NUM> is flexible in bending about attachment end 72a. Applying a force to engagement end 72b displaces tab <NUM> away from front plate <NUM> and thereby disengages lip <NUM> from locking surface <NUM>. Typically, tabs <NUM> are actuated by hand. To facilitate actuation of tab <NUM>, tab <NUM> can include curved portion <NUM>. With curved portion <NUM>, tab <NUM> extends from attachment end 72a along front plate <NUM> and exterior side <NUM> of door <NUM> and is curved between intermediate location <NUM> and engagement end 72b such that tab <NUM> extends away from front plate <NUM>, providing additional access to tab <NUM> for hand operation.

<FIG> is a perspective view of sprayer <NUM> with front cover <NUM> removed to show pump assembly <NUM> mounted to end bell <NUM> within sprayer <NUM>. Pump assembly <NUM> includes mounting holes <NUM> which are formed by a component of pump assembly <NUM> (e.g., a housing) or an external component joined to pump assembly <NUM>. Mounting holes <NUM> are adapted to receive protrusions <NUM>, which are joined to and extend from end bell <NUM>. The number and configuration of mounting holes <NUM> and protrusions <NUM> are selected to restrain pump assembly <NUM> with respect to end bell <NUM>, and more particularly, to restrain a pumping motion of pump assembly <NUM> with respect to end bell <NUM> while permitting pump assembly <NUM> to translate freely for assembly and disassembly from sprayer <NUM>. Additionally, with front cover removed, various components of the pump drive can be accessed and removed for repair, cleaning, or other maintenance.

In the embodiment shown, pump assembly <NUM> includes piston <NUM> that reciprocates along a lengthwise direction of piston <NUM> (i.e., upward and downward directions as depicted in <FIG>). To restrain the reciprocating motion of piston <NUM>, pump assembly <NUM> includes a pair of mounting holes <NUM>, each mounting hole <NUM> disposed on opposing sides of piston <NUM>. Mounting holes <NUM> are spaced equally from piston <NUM> such that the load imposed on each mounting hole <NUM> is substantially equal. The centerline of piston <NUM> is equally spaced between mounting holes <NUM>, but is offset with respect to the centerline of the gear <NUM> of drive assembly <NUM>. This is done so that the load is centered on piston <NUM> during the downstroke, which is the highest pumping load. During the upstroke, piston <NUM> only has to overcome the drag of the packing assembly. The pair of mounting holes <NUM> is adapted to receive a pair of protrusions <NUM>. The pair of protrusions <NUM> extends in a longitudinal direction from a side of end bell <NUM> that is opposite electric motor <NUM>, and can be substantially perpendicular to a reciprocating direction of piston <NUM>. Furthermore, each protrusion <NUM> can be substantially parallel to each other protrusion <NUM> and thereby facilitate removing pump assembly <NUM> by sliding pump assembly <NUM> along the longitudinal direction away from end bell <NUM>.

Thus, the mounting interface between pump assembly <NUM> and end bell <NUM>, whether configured as a discrete component or integrated into a support frame, includes a pair of mounting holes <NUM> and a pair of protrusions <NUM> cantilevered from end bell <NUM>. As configured in <FIG>, the pairs of mounting holes <NUM> and protrusions <NUM> restrain pumping assembly <NUM> relative to end bell <NUM> against the reciprocating motion of piston <NUM> when pump assembly <NUM> is slid onto protrusions <NUM>. Additionally, the reception of protrusions <NUM> within mounting holes <NUM> permit pump assembly <NUM> to be mounted to or removed from sprayer <NUM> without tools when door <NUM> is in the open position. With the configuration depicted by <FIG>, the weight of pump assembly <NUM> is supported by end bell <NUM> via protrusions <NUM> and is not supported by front cover <NUM>.

In <FIG>, mounting holes <NUM> take the form of bores that extend through a component of pump assembly <NUM>. The bores form cylindrical bearing surfaces that are sized to form a sliding fit with protrusion <NUM>, which take the form of cylindrical pins. Protrusions <NUM>, particularly if protrusions <NUM> are formed by discrete pins, can be press fit into a recess within end bell <NUM>. Alternatively, protrusions <NUM> can be attached to end bell <NUM> using other methods such as welding or brazing, or protrusions <NUM> can be integrally machined into end bell <NUM>. Protrusions <NUM> extend a distance in the longitudinal direction that is less than the distance between front cover <NUM> and end bell <NUM>. In this instance, protrusions <NUM> do not contact and are not mechanically supported by front cover <NUM>.

Pump assembly <NUM> further includes collar <NUM> that is adapted to engage coupler <NUM> of pump drive <NUM>. Collar <NUM> is joined to piston <NUM> and is configured to permit installation and removal of pump assembly <NUM> from sprayer <NUM> without tools. For example, collar <NUM> can be integrally formed at a free end of piston <NUM> or joined to a free end of piston <NUM>. When pump assembly <NUM> is installed within sprayer <NUM>, such as <FIG> depicts, coupler <NUM> and output gear <NUM> restrain collar <NUM> in a reciprocating direction of piston <NUM>. To facilitate installation and disassembly of pump assembly <NUM> without tools, coupler <NUM> has open end <NUM> that faces away from end bell <NUM> (i.e., in an outward direction). In some embodiments, coupler <NUM> has a U-shaped cross-section, open end <NUM> being situated between side portions of the U-shaped coupler <NUM>. With this configuration, piston <NUM> of pump assembly <NUM> is received between side portions of U-shaped coupler <NUM> when pump assembly <NUM> is assembled within sprayer <NUM> by sliding mounting holes <NUM> on to protrusions <NUM>.

<FIG> is an exploded view that shows pump assembly <NUM> after mounting holes <NUM> have been slid off of pin-shaped protrusions <NUM>. Such forward sliding motion (i.e., in a direction away from end bell <NUM>) allows piston <NUM> to be disengaged from coupler <NUM> and mounting holes <NUM> to slide off and disengage protrusions <NUM>. Once separated from the rest of the sprayer <NUM>, pump assembly <NUM> can be serviced. For example piston <NUM> can be removed and packing seals, check valves, and/or other components can be cleaned or replaced. As noted previously, the removal of the pump assembly <NUM> via the enclosure interior <NUM> being exposed by pivoting of the door <NUM> allows the servicing of the pump without removal of the front cover <NUM>. It is noted that the front cover <NUM> helps secure the components of pump drive <NUM> such as output gear <NUM> and coupler <NUM> among various other components such that pump assembly <NUM> can be removed through an open door <NUM> without detaching or otherwise exposing components of pump drive <NUM> contained between front cover <NUM> and end bell <NUM> and electric motor <NUM> (see <FIG>) within motor housing <NUM> (see <FIG>).

While the sliding action of door <NUM> from the locked position or closed position to the unlocked position and vice versa can serve as a mechanical lock that prevents door <NUM> from swinging open (the pivoting motion otherwise meeting minimal mechanical resistance), the sliding action can also establish and break an electrical connection. For example, as discussed previously, pressure control <NUM> can electrically control the state motor <NUM> within motor housing <NUM> (see <FIG>). However, if pump assembly <NUM> is to be removed, and the pressure control <NUM> is contained on the pump assembly <NUM>, then one or more wired connections extending from the pressure control <NUM> to motor <NUM> may need to be broken to remove pump assembly <NUM>. The sliding motion of the door <NUM> is a convenient motion for establishing and breaking a robust electrical connection. The electrical connection is established and broken in part using electrical connector part <NUM>, which is mounted on pump assembly <NUM>. One or more insulated wires can run along pump assembly <NUM> via a cable and between pressure control <NUM> and electrical connector part <NUM>. The electrical connection is further explained in connection with <FIG>.

<FIG> show a cross sectional view of sprayer <NUM> in the states shown in <FIG>, respectively. Specifically, <FIG> shows door <NUM> in a locked position or closed position, <FIG> shows door <NUM> in an unlocked position, and <FIG> shows door <NUM> in an open position. <FIG> also show electrical connector part <NUM> which is connected to and moves with the door <NUM>. Parts <NUM> and <NUM> of the electrical connector are separate parts that include interfacing electrical contacts. When engaged as shown in <FIG>, parts <NUM> and <NUM> establish an electrical connection that is used to conduct a signal from pump assembly <NUM> to a component within enclosure <NUM>. For example, parts <NUM> and <NUM> can conduct a signal from pressure control <NUM> to motor <NUM> when engaged. Contrastingly, an electrical connection is broken when parts <NUM> and <NUM> disengage, as in the unlocked state of <FIG> or the open state of <FIG>. When disengaged, signals from the pump assembly <NUM>, such as a pressure-control signal from pressure control <NUM>, are prevented from conducting through parts <NUM> and <NUM> of the electrical connector. Details of the electrical connector are described below.

As best shown in <FIG>, electrical connector part <NUM> includes one or more projections <NUM> that are received in one or more recesses <NUM> of electrical connector part <NUM>. Alternately, electrical connector part <NUM> could include one or more recesses that receive one or more projections of electrical connector part <NUM>. The reception of a projection in a recess can create an elongated seal to prevent paint, or another material dispensed from sprayer <NUM>, from reaching the electrical contacts within the electrical connector parts <NUM> and <NUM>. The sliding motion of door <NUM> relative to front cover <NUM> facilitates the reception of a long projection (e.g., projection <NUM>) within a deep recess (e.g., recess <NUM>), and therefore facilitates the electrical isolation of the electrical connection established between electrical connector parts <NUM> and <NUM> from paint.

The distance that parts <NUM> and <NUM> of electrical connector overlap defines an engagement length. In embodiments of front plate <NUM> and door <NUM> that include catch <NUM> and latch <NUM>, respectively, the engagement length is less than length L of catch <NUM>. With this arrangement, electrical connector parts <NUM> and <NUM> fully disengage before door <NUM> is in the unlocked position, which prevents damage to electrical connector parts <NUM> and <NUM> from premature pivoting of door <NUM> into the open position. In other embodiments, the engagement length is at least half the linear distance door <NUM> translates from the locked position to the unlocked position. In each embodiment, the engagement length forms a seal between parts <NUM> and <NUM> of the electrical connector by creating a tortuous path that prevents infiltration of debris and the material dispensed from sprayer <NUM>.

Some embodiments of electrical connectors include sleeve <NUM> that encircles one of parts <NUM> and <NUM> of the electrical connector. Sleeve <NUM> extends from either part <NUM> or part <NUM> towards the other of parts <NUM> and <NUM> when viewing door <NUM> in the locked position. Interior surfaces of sleeve <NUM> are tapered inward from a distal end towards a proximal end for at least a portion of sleeve <NUM> to facilitate engagement of parts <NUM> and <NUM> when door <NUM> is translated into the locked position or closed position. For example, <FIG> show part <NUM> equipped with sleeve <NUM>. As best shown in <FIG>, the interior surfaces of sleeve <NUM> are tapered such that the open area cross-section of sleeve <NUM> at an end facing part <NUM> (i.e., the distal end) is larger than the open area cross-section of sleeve <NUM> at an end of sleeve <NUM> connected to part <NUM> of the electrical connector (i.e., the proximal end). Embodiments utilizing sleeve <NUM> tolerate small amounts of misalignment between door <NUM> and pump assembly <NUM> when door <NUM> translates into the locked position.

Part <NUM> of the electrical connector connects with one or more wires that extend along the pivoting connection between the door <NUM> and the front cover <NUM> and can further extend to the motor to relay control signals between the pressure control <NUM> and the motor (e.g., on and off signals). These wires can form cable <NUM>.

Some embodiments include cable support <NUM> to support cable <NUM> with respect to door <NUM>. In these embodiments, cable <NUM> extends from electrical connector part <NUM> through cable support <NUM>. Cable support <NUM> protrudes from a portion of door <NUM> adjacent to pivot axis P such that a gap is formed between an interior surface of door <NUM> and cable support <NUM>. In some embodiments, cable support <NUM> can be contoured to support cable <NUM> at a bend when door <NUM> is pivoted between the unlocked position and the open position as is generally depicted by <FIG> and <FIG>. By contouring cable support <NUM>, damage and wear to cable <NUM> caused by translating and pivoting door <NUM> can be reduced or eliminated. Other embodiments are further equipped with an aperture extending through door <NUM> and aligned with cable support <NUM> to facilitate threading cable <NUM> through the gap created by cable support <NUM>.

The perspective view of <FIG> and the cross sectional views of <FIG> show various additional components of sprayer <NUM>. For example, the views show that pump assembly <NUM> includes cylinder <NUM> within which piston <NUM> reciprocates, as driven by motor <NUM>, to pump paint. The cross sectional views of <FIG> also show that shaft <NUM> driven by motor <NUM> engages input gear <NUM>. Input gear <NUM> is affixed rotationally to shaft <NUM> and is rotatably coupled to output gear <NUM>, which is coupled to coupler <NUM> (sometimes referred to as a yoke). As best depicted by <FIG>, output gear <NUM> includes eccentric shaft <NUM> that is offset from a rotational axis of output gear <NUM> and extends into an egg-shaped bore of carrier <NUM>. Carrier <NUM> is allowed to slide along at least one rail <NUM>, which is restrained by one or both of end bell <NUM> and front cover <NUM>. A bearing <NUM> can be positioned between eccentric shaft <NUM> and carrier <NUM> to reduce frictional forces generated by the relative motion of carrier <NUM> and output gear <NUM>.

Claim 1:
A paint sprayer (<NUM>) comprising:
an end bell (<NUM>) in the form of a plate having a first side (12a) and a second side (12b) opposite to the first side (12a);
a motor (<NUM>) and a motor housing (<NUM>) connected to the first side (12a) of the end bell;
a pump drive connected to the second side (12b) of the end bell, the pump drive configured to convert rotational motion output by the motor to reciprocal motion;
a pump assembly (<NUM>) removably mounted on the second side of the end bell and containing a piston pump, wherein the piston pump is configured to pump paint when reciprocated by the pump drive while mounted on the end bell;
a cover (<NUM>), the cover mounted to the end bell such that the pump drive is located between the cover and the end bell; and
a door (<NUM>) attached to the cover (<NUM>), the door moveable between an open position and a closed position, wherein the door blocks the pump assembly (<NUM>) from being removed from the end bell while in the closed position but permits the pump assembly to be removed from the end bell while in the open position.