The present invention relates to cordless power tools and devices that use battery packs, and more particularly, an improved receptacle for battery packs.
Cordless power devices are useful in the concrete industry especially with respect to concrete finishing tools, such as floats, jointers, screeds, and the like. Concrete finishing tools provide a particular finished surface adjusted to a freshly poured concrete mass. In the conventional method of use of such concrete finishing tools, an operator moves the tool across the surface of the freshly poured concrete, usually in a back-and-forth manner, before the concrete mass cures or dries. Cordless concrete finishing tools use vibratory action to aid in the creation of a surface, characteristic, such as a smooth surface and in the case of a jointer, possesses a groove to control cracking of the finish concrete slab.
Vibration devices for concrete finishing tools include those where an external motor is mounted to a handle or shaft and linked to a remote vibration mechanism by the use of a cable or gear mechanism and where a power source is placed within the handle of the concrete finishing tool and provides power to vibrators that are located atop of the head of the finishing tool adjacent the concrete. Additionally, some concrete finishing tools include a vibrator that is placed within the handle structure of the tools and powered by a battery that is also found in the handle. Other vibration devices employ a vibrator mechanism between the handle and terminus of the concrete finishing tool and allows for optimum vibration of the vibrator mechanism and to automatically assist the operator in propelling the concrete finishing tool forward and backward.
For many cordless concrete finishing tools like other cordless tools and devices, a removable and often rechargeable battery pack supplies power to the tool via a battery receptacle. For some tools, the battery pack is a rail-style battery pack that slides into a rail-style battery receptacle. The rail-style interface system between the battery pack and receptacle is desirable for its advantages over a tower-style interface. For example, a rail-style interface provides separate mechanisms for supporting the weight of the battery back (e.g., rails) and securing the battery pack to the tool (e.g., a latch). Also, the terminal block area of a rail-style battery pack facilitates system expansion as there is space to add additional terminals. The battery cells are contained in the body of the battery pack and there is no need to locate a cell remotely as with a tower-style battery pack. The rail-style battery pack is also simpler to manufacture and more reliable than tower-style systems.
Unfortunately, because of the vibrations imparted by the tool, both rail-style and tower-style battery packs and the battery receptacles are susceptible to failure. When the tool vibrates, excess force and rapid movement causes repeated stress on the battery pack, the battery receptacle, and points of connection between the battery pack and receptacle. Accordingly, it would be desirable to provide a battery receptacle that includes features to reduce stress at the interface between the battery pack and battery receptacle when used with cordless concrete finishing tools. Moreover, it would be desirable to provide an improved rail-style battery receptacle for all tools or devices that vibrate to accommodate rail-style battery packs. Such a receptacle would be a notable advance in the construction arts.
In accordance with the present invention several embodiments of a novel and useful resilient rail-style battery interface system for vibrating tools and devices are herein provided. The battery interface system provides features to counteract any excess force and rapid movement caused by the vibrations of the power tool or device coupled to an improved battery receptacle that can receive removable and optionally rechargeable battery packs. The battery receptacle includes a base supporting two opposing lateral side walls and a third wall disposed between them. At one end of the base there is an opening and at the other end, near the third wall and between the lateral side walls, there is a terminal block that includes a terminal face from which contacts extend. The base also defines a groove along a portion of each side wall, and each side wall includes an arm that extends inward above the groove in the base. The area along each side wall that is under the arm and above the groove is a rail recess that receives cooperating rails on a battery pack. Positioned partly within each groove is a resilient member that provides resistance by imparting force against the battery pack rails when the battery pack rails are positioned in the battery receptacle rail recesses. In some embodiments, the grooves may be slots and an adapter plate may be used under the battery receptacle to provide a stable surface for mounting the battery receptacle to irregular and non-planar surfaces and to provide resistance for the resilient member. The battery receptacle also preferably includes additional features common to battery receptacles such as structures or openings to facilitate fastening the battery receptacle to a tool or device, leads couple to the contacts in the battery receptacle and to the power tool for establishing an electrical connection, latch recesses or members to lock a cooperating battery pack in place, and protection circuits.
Operationally, the battery receptacle receives and holds a battery pack when a source of battery power is needed to operate the power tool or device coupled to the battery receptacle. When the rails on a battery pack are fully inserted into the rail recesses of the battery receptacle, contacts of the battery pack couple with the contacts on the battery receptacle to supply power to the attached power tool or device. At that time, each resilient member applies additional support for the battery pack rails and presses the rails against the arms on the battery receptacle to act as a snubber to counteract any excess force or rapid movement caused by the power tool or device.
For a better understanding of the invention reference is made to the following detailed description of the preferred embodiments of the invention which should be taken in conjunction with the above described drawings.
Various aspects of the present invention will evolve from the following detailed description of the preferred embodiments thereof which should be referenced to the prior described drawings.
Base 110 also supports a receptacle terminal block 130 that is preferably positioned between a portion of lateral side walls 120, at a distance for the base open end 114, and near the third wall 128. Receptacle terminal block 130 houses, supports, or accommodates any needed circuitry and electrical connections and is preferably integrally connected to base 110. Receptacle terminal block 130 includes a terminal end 130 defined by two opposite lateral terminal side walls 132 and a terminal face 134 extending generally perpendicular to and between the two opposite lateral terminal side walls 132. A terminal block recess 133 may be present if terminal block sidewalls 132 sit at a spaced distance from side walls 120 as shown in
Extending from the terminal face 134 toward the first end 114 of base 110 near terminal side walls 132 are positive and negative contacts 136 and 138. For example, a positive contact 136 can extend from terminal face 134 near one lateral terminal side walls 132, and a negative contact 138 can extend from terminal face 134 near the opposite lateral terminal side wall 132. Additional contacts can be included depending on the cooperating battery pack, as will be understood by those skilled in the art. The positive and negative contacts 136 and 138 are configured to receive contacts on a cooperating battery pack 200 to provide electrical connection therebetween. The contacts 136 and 138 are further coupled to positive and negative leads 166 and 168 within or at the terminal block 130, and the positive and negative terminal 166 and 168 leads exit terminal block 130 through third wall 128 as shown in
Base 110 also preferably includes a pair of opposing lateral grooves 112 adjacent to and along a portion of side walls 120 as shown in
Partially disposed in or through each groove 112 of battery receptacle 100 is a resilient member 140 that acts as a snubber to combat excess force or rapid movement caused by the vibrating of the tool or device when it is operating.
Preferably, the width W and thickness T of resilient member 140 is substantially consistent across its multiple sections. Thickness T is preferably about 0.031 inches but can be any thickness that provides adequate resistance and support when under pressure and that can be formed into the desired shape. Width W is preferably a width that can be inserted easily in groove 112 and more preferably is between 0.15 and 0.30 inches. More preferably, width W is 0.17 inches or 0.25 inches. The overall length L1 of resilient member 140 is preferably a length that can be inserted easily in groove 112. Preferably, L1 will be approximately the length of groove 112 or smaller. Preferably, length L1 is between 1.0 and 3 inches and more preferably is between 1.68 and 2.02 inches. A second length L2 corresponds to the portion of length L1 that is overlapped by the first and second bend sections 143 and 145 and the angled section 144 as shown in the
First and second bends 143 and 145 of resilient member 140 have a radius of R1 and R2 respectively, where preferably R1 and R2 have the same radius and more preferably it is about 0.19 inches. Radius R1 and R2 can differ and can be larger or smaller than 0.19 inches provided resilient member 140 provides adequate resistance and support when under pressure. The angles A1 and A2 between the base section 142 and angled section 144 and between the angled section 144 and the end section 146, respectively, are likewise preferably equal to one another. As shown in the Figures, A1 and A2 are about 40 degrees. Angles A1 and A2 can differ and can be larger or smaller than 40 degrees provided resilient member 140 continues to provide adequate resistance and support when under pressure. End section 146 is preferably of negligible length so that it does not prevent resilient member 140 from compressing when under pressure but can be longer if desired or if needed to prevent resilient member 140 from excessive compression when under pressure.
The following table includes examples of appropriate dimensions for three different configurations of resilient member 140 as used with a battery receptacle 100 configured to cooperate with a Makita brand rail-style battery (Resilient Member 1), a Milwaukee brand rail-style battery (Resilient Member 2), and a DeWalt brand rail-style battery (Resilient Member 3).
While a spring clip is shown and described herein as an appropriate configuration of resilient member 140, it is anticipated that resilient member 140 includes any resilient structure that can fit within or through groove 112 to provide resistance against the rail 224 of battery pack 200 when it is positioned in the rail recess 124 of battery receptacle 100.
Base 110 further preferably includes features necessary for connecting base 110 to other devices and tools, for cooperating with and securing the battery pack 200, and for protecting or facilitating the electrical connection between the battery pack 200 and receptacle 100 and between the receptacle 100 and the attached power tool or device. For example, base 110 may include mounting hardware extending from base 110 (not shown), or it may define openings configured to accept fasteners. For example, as shown in
Battery receptacle 100 further optionally includes features for protecting or facilitating the electrical connection between the battery pack 200 and receptacle 100 or between the receptacle 100 and the attached power tool or device. For example, battery receptacle 100 may include protection circuits (not shown) housed within the terminal block 130.
An exemplary battery pack is illustrated in
Along each terminal block lateral side 232 of the battery pack 200, a rail 224 extends outwardly. Rail 224 is configured to cooperate with the rail recess 124 the battery receptacle 100 and portions of rails 224 may extend into the battery receptacle's terminal block recesses 133 when present to allow the battery receptacle terminal block 130 to extend into the battery pack terminal recess 235.
Battery pack 200 also includes any necessary attachment and locking means such as a latch system for cooperating with a latch recess 150 on battery receptacle 100. As shown in FIG., 4, the latch system includes a pair of latch release buttons 250 that operate a pair of movable latch members 252 such that when latch release buttons 250 are engaged, latch members 252 withdraw into the battery terminal block 230 so the battery pack 200 can be easily slide on and be positioned in battery receptacle 100. Once the battery pack 200 is fully seated, the latch release buttons cease to be engaged and preferably the latch members 252 engage the latch recesses 150 on battery receptacle 100. To uncouple the battery pack 200 from battery receptacle, the latch release buttons 250 are engaged to withdraw the latch members 252 so that the battery pack can side out. Other latch arrangements can be used to lock battery pack 200 in battery receptacle 100 as will be known to those skilled in the art.
Where housing 320 has a circular or irregular surface or cross-section, such as the inline vibrator mechanism shown in
Operationally, battery receptacle 100 receives and holds battery pack 200 when a source of battery power is needed to operate the power tool or device coupled to battery receptacle 100. To establish a proper connection between battery receptacle 100 and battery pack 200, the rails 224 on battery pack 200 are introduced at the open end 114 of base 110 to the rail recesses 124. Rails 224 are then slid into the rail recesses 124, which applies force to resilient members 140 and causes them to compress. Once the rails 224 are fully inserted into rail recesses 124, the terminal face 134 of battery receptacle block terminal 130 and terminal face 234 of battery pack block terminal 230 should be positioned adjacent to each other and the battery receptacle contacts 136 and 138 couple to the battery pack contacts 238 and 236 to form an electrical connection. Once positioned so, resilient members 140 also apply additional support for rails 224 and press rails 224 against arms 122 on battery receptacle 100. Additionally, any latch members 252 on battery pack 200 become inserted in latch recesses 150 on battery receptacle 100 to lock battery pack 200 in place. When battery pack 200 is positioned correctly in battery receptacle 100 and locked in place, the associated power tool or device becomes coupled to battery pack 200 so that it can operate cordlessly. With the improved design of the battery receptacle, power tools or devices that vibrate benefit from battery receptacle's resilient members 140, which act as a snubber to counteract any excess force or rapid movement caused by the power tool or device. To remove battery pack 200 from receptacle 100, the latch release buttons can be engaged to withdraw the latch members 252 from latch recesses 150, and then battery pack 200 can slide out of rail recesses 113 and battery receptacle 100 at base opening 114.
While in the foregoing, embodiments of the present invention have been set forth in considerable detail for the purposes of making a complete disclosure of the invention, it may be apparent to those of skill in the art that numerous changes may be made in such detail without departing from the spirit and principles of the invention.