DETAILED DESCRIPTION OF THE DISCLOSED EMBODIMENTS
 Referring first to FIGS. 1-5, there is shown an embodiment 20 of a rotatable gutter system of the present invention. FIG. 1 depicts one gutter section 22 that includes a trough 24 and an end piece 26 at each end of the trough. In use, the gutter 22 of FIG. 1 is mounted to a building's fascia by way of a pair of support members 30 (FIGS. 4 and 5) that both support the gutter 22 via its end pieces 26 and permit the gutter 22 to be rotated between an open position and a closed position. Referring briefly to FIGS. 6-8, the open position is the normal operative or working position in which the trough 24 opens upwardly such that it can collect rain water shed off the roof of the building upon which the gutter system 20 is installed. The closed position is a cleaning or storage position in which the gutter 22 is rotated from its open position through some large angle (normally 90° to 270°, and preferably 180°) so that leaves and other debris in the trough 24 will fall out and can be flushed out using a nozzle spray from a garden hose by a person on the ground. Only one of the two support members 30 used for a gutter section is shown in the drawings and it will be appreciated that the second support member would be substantially if not entirely identical to the one support member shown.
 As shown in FIG. 1, the gutter 22 is formed from the trough 24 and two end pieces 26 which are rigidly attached to the trough. Each end piece 26 includes a circular shoulder 32 on which its associated end of the trough 24 rests. At least one of the end pieces 26 includes a drive member 34 which, in the illustrated embodiment is in the form of a drive post 36. As will be described in greater detail below, the gutter 22 can be rotated via its drive post 36 using some drive mechanism such as the hand tool 40 of FIG. 3. This tool 40 has an aperture 42 that is keyed to fit over the drive post 36, and also includes a pivot link 44 to an elongated rod or handle 46. A housing 48 can be interconnected between the pivot link 44 and handle 46 and can be threaded to receive the top end of the handle 46. Using this handle, a person standing on the ground can slide the aperture 42 over the drive post 36 and then manipulate the handle 46 to rotate the gutter 22 through the desired angle to switch between the open and closed positions.
 The trough 24 and end pieces 26 can be made from PVC, with the end pieces being cemented (adhered) to the trough to make a single integral section of gutter, as shown. Of course, other suitable materials could be used, and screws and other means of fastening the end pieces 26 to the trough 24 could utilized to form the integral section of gutter. Alternatively, one or both of the end pieces 26 could be formed as a unitary part of the trough 24. Furthermore, although the illustrated embodiment utilizes a trough of circular cross-section, any other cross-sectional shape can be used as long as it is suitable for collecting water shed from the building roof. As shown, some of the end piece material located between its drive post 36 and outer periphery 38 can be eliminated to reduce weight and material costs.
 FIG. 2 depicts an exploded view of one end of the illustrated gutter system 20.
 As described above, the gutter 22 includes both the trough 24 and the end piece 26, with the latter being captively held by the support member 30 which, in the illustrated embodiment, includes an end cap 50 and a retaining ring 52. As shown in FIG. 4, each end cap 50 includes a base 54 and a unitary gutter support section 56. The base 54 has a flat mounting surface 58 and includes a pair of slide locks 60 that can be used to hang the end cap 50 from screws or posts on the building fascia. These slide locks 60 can be made as a unitary part of the end cap 50 or can be made separately and snap fit or otherwise attached to the end cap. In addition to or in lieu of using the slide locks 60, the end caps 50 can be attached to brackets (not shown) mounted on the building fascia, rather than the end caps being mounted directly to the fascia itself. Where slide locks 60 are used, it will be appreciated that the slot pattern for the other end cap will have the same orientation as that shown in FIG. 4 even though the remainder of the end cap will be inverted from the depicted orientation.
 Referring now to both FIGS. 4 and 5, the gutter support portion 56 of the end cap 50 comprises an annular flange 62 and annular end wall 64, with the flange providing the actual support for the end piece 26 of the gutter 22, and the end wall 64 preventing axial movement of the gutter. These components can also be made from PVC or some other suitable material. The end wall 64 includes a central opening 66 through which the drive post 36 extends to an exposed location where it can be accessed by the hand tool 40 or other drive mechanism. As best seen in FIG. 5, the retaining ring 52 attaches to the end cap 50 after insertion of the end piece 26 into the end cap. The retaining ring 52 is then fastened to the end cap 50 via removable fasteners such as screws 68, although it could be permanently attached as well. The inside diameter of the retaining ring 52 is the same as the outside diameter of the trough 24 which is smaller than the diameter of the end piece's circular shoulder 32. Consequently, the gutter 22 cannot move axially in either directly relative to the support members 30 due to interference of the end piece 26 with the retaining ring 52 and the end wall 64 of the end cap. Where the gutter is securely mounted between opposing end caps, the retaining rings may not be needed, as axial movement of the gutter in both directions will be limited by the two end caps.
 As is also best seen in FIG. 5, rotation of the drive post 36 causes concomitant rotation of the entire gutter 22 about a central axis of rotation 70. As will be appreciated by those skilled in the art, rather than using a drive post that is keyed for positive engagement with a drive mechanism, frictional engagement between the drive mechanism and drive post can be used. Furthermore, the drive member used on the gutter end piece need not comprise a drive post, but could be a keyed aperture in the end piece that is accessible at the end cap's opening by a drive post that is part of the drive mechanism itself.
 Turning now to FIGS. 6-8, the gutter system 20 can also include a rubber or other flexible drip edge 72 that can be mounted, for example, on the building fascia 74 above the gutter 22 underneath the lowest roof shingle 76. When the gutter 22 is in the open position, the drip edge 72 helps insure that water is deflected into the trough 24 so that no water gets between the gutter and building fascia. This is shown in FIG. 6. When the gutter 22 is rotated clockwise (using the orientation shown in the figures), the drip edge 72 contacts and seals against the outer (bottom) surface of the trough 24, as shown in FIG. 7. This not only prevents water from falling between the gutter and building fascia, but may also help prevent formation of ice dams during the winter. In this regard, it will be appreciated that, regardless of whether the drip edge 72 is used, the gutter 22 can be maintained in its closed position during the winter months which can help reduce the formation of ice dams due to the curved design of the trough. Moreover, in the event ice does begin to form, the gutter can be rotated 360° (closed to open to closed) to break off any ice forming.
 The drip edge 72 can extend the length of the trough 24 between the end pieces 26 and can terminate just inwardly of each end cap 50. Alternatively, the end caps 50 can be open at the upper portion of the annular flange 62 so that the drip edge 72 can extend all of the way axially to the ends of the trough 24.
 FIGS. 6 and 7 show rotation of the gutter 22 is a single direction—clockwise.
 This may be preferred where the drip edge 72 is used so that it properly seals in the manner shown in FIG. 7. Although not necessary, this uni-directional rotation can be incorporated into the design of the end piece 26 and/or end cap 50 so that reverse rotation is not possible. Alternatively, the drive mechanism used to rotate the gutter 22 could be designed to rotate in a single direction only. Those skilled in the art will be familiar with ratcheting and other such means of limiting rotation to one direction only. Regardless of whether uni-directional rotation is used, the end piece 26 or some other portion of the gutter 22, can include detents that indicate when the gutter has reached its open and/or closed positions. Also, as will be appreciated by those skilled in the art, the total amount of rotation can be limited using stops, for example, so that uni-directional rotation is not possible. In this way, the gutter will only rotate through some maximum angle, say 180°, between its open and closed positions, and must be rotated in the reverse direction to return it to its initial position.
 FIG. 9 depicts a corner cover or diverter 80 than can be used at valley intersections between different roof regions 82 to divert water away from the end caps 50 located at the comer and into the troughs 24. These comer covers 80 can be installed under the lower or lowest courses of shingles using known roofing techniques. If desired, a downspout (not shown) can be located under these valley intersections (either with or without the comer cover 80) to collect and route water not captured in the gutters.
 FIG. 10 shows one possible embodiment of an interface between the trough 24 and a downspout 90 that permits the gutter 22 to be rotated relative to the downspout 90 and that permits downspout 90 to provide additional support for the gutter, if desired. The trough 24 includes an opening 92 in its lower portion, and this opening is aligned with the upper opening 94 in the downspout 90 when the gutter is in its open position. The downspout 90 can have a pair of opposed upstanding extensions 96 that engage and cradle the bottom side of the trough 24. Alternatively, the top of the downspout 90 need not be in physical contact with the trough 24, as shown. The top portion of the downspout 90 illustrated in FIG. 10 can be a unitary portion of the entire downspout, or can be a separate piece that attaches to a standard or nonstandard downspout.
 Turning now to FIGS. 11-15, various drive mechanism embodiments are disclosed. Each of these embodiments is designed to mate with the drive post 36 used on the gutter end piece 26 so that these different drive mechanisms are interchangeable. Of course, the other drive topologies discussed above in connection with FIG. 5 can be used so that, for example, the drive mechanisms can be constructed with a drive post (instead of an aperture) that mates with a keyed aperture (instead of a drive post) in the end piece 26.
 FIG. 11 depicts a hand tool 100 such as that shown in FIG. 3, with the difference being that the hand tool 40 of FIG. 3 includes a fixed length handle 44 threaded into an upper housing 48, whereas that of FIG. 11 has an extendible (e.g., telescoping) handle 102. FIG. 12 depicts a pulley system 110 that uses and endless loop of rope 112 hanging from a pulley 114 enclosed in a housing 116 that attaches to the end cap 26 via screws 118. The center of the pulley 114 includes a keyed aperture 120 that mates with the drive post 36 of the gutter end piece 26. FIG. 13 depicts a hand grip tool 130 that includes an upper housing 132 that holds a ratchet device 134. Extending down from the housing 132 is a frame 136 terminating at a holding handle 138. A second, grip handle 140 is pivotally attached to the frame 136 near the holding handle 138 and a pair of links 142 extend from the grip handle 140 up to a pair of pins 144 that extend out of each axial side of the ratchet device 134. By squeezing the handles together, the links 142 pull on the pins 144, causing rotation of the ratchet device 134 and, thus the keyed aperture 146 at the center of the ratchet device. FIGS. 14 and 15 depict a motor drive 150 that attaches to the end cap 26 using screws 152. The motor drive 150 includes a housing 154 containing a drive gear 156 having a keyed aperture 158 for connecting to the drive post 36 of the gutter end piece 26. The drive gear teeth meshes with a worm gear 158 connected to the output shaft of a single drive or reversible drive motor 160 which can be battery operated or connectable to line voltage via a power cord 162. The unit 150 can be wired to a remote switch (not shown) or can include a wireless receiver 164 that receives commands from a remote transmitter (not shown) using r.f., i.r., or other types of signals.
 It will thus be apparent that there has been provided in accordance with the present invention a rotatable gutter system which achieves the aims and advantages specified herein. It will of course be understood that the foregoing description is of exemplary embodiments of the invention and that the invention is not limited to the specific embodiments shown. Various changes and modifications will become apparent to those skilled in the art. For example, additional supports could be installed at spaced locations between the end caps for longer sections of gutter. These could take the form of a bracket having a curved support surface against which the bottom of the trough rests. All such variations and modifications are intended to come within the scope of the appended claims.