Field of the Invention
This invention generally relates to interval timers and particularly concerns an adjustment mechanism suited to be used with a spring wound interval timer for establishing a presettable period of runout to a timed-out position upon actuating a winding knob.
Background of the Invention
There are a number of types of different interval timer mechanisms. Such mechanisms may provide for a single output such as an audible sound or the closing or opening of a pair of electrical contacts upon expiration of a predetermined timed interval. Many of these mechanisms have been used in the past with a presettable period of runout to a timed-out position by initiating an operation to be timed by a push button release or a pointer on a manually actuated winding knob drivingly connected to the timer mechanism. To limit the period of runout to a timed-out position for controlling a given operation, it has been customary to provide different timers each presettable to different maximum timed intervals or which are simply adjustable by the user to variable dial settings. However, a user having a one hour or two hour timer and desiring to repeatedly and reliably preset a longer timing cycle, by simply actuating a winding knob against a stop, will have need for a different timer. Such need may be reflected, for example, in an operation such as changing an energy conservation program in a public or commercial building.
Summary of the Invention
This invention provides a new and improved stop adjustment mechanism for use with a spring wound interval timer. The stop adjustment mechanism of this invention is specifically designed to ensure that it is not easily changed by a user but is nonetheless adjustable for different applications requiring different given timing cycles to be repeatedly established by the timer. The timer includes a setting shaft extending through an aperture of a face plate attached to the timer. The face plate features a stud integrally fixed to protrude from an exposed side of the face plate. To adjust the timer for repeatedly establishing a desired time interval upon initiating operation of a given timing cycle, a stop member is mounted in overlying relation to the face plate with an aperture formed in the stop member corresponding to the face plate aperture for receiving the timer setting shaft. A plurality of stud receiving openings are formed in the stop member such that it may be positioned in different relative angular positions, whereby a protrusion formed to project from the stop member may be disposed in different preselected angular positions relative to the timed-out position of the setting shaft. A manual winding knob is mounted on the timer setting shaft and has an indicating pointer cooperating with a dial on the face plate for manually setting a desired timed cycle. The winding knob pointer is movable into interfering relation with the protrusion of the stop member, which is fixed in adjusted position, for initiating a desired preset runout cycle.
Other objects will be in part obvious and in part pointed out in more detail hereinafter.
A better understanding of the objects, advantages, features, properties and relations of the invention will be obtained from the following detailed description and accompanying drawings which set forth a certain illustrative embodiment and is indicative of the various way in which the principle of the invention is employed.
Brief Description of the Drawings
FIG. 1 is an exploded isometric view of an interval timer and time interval adjustment mechanism incorporating this invention;
FIG. 2 is a plan view of a face plate used in the mechanism of FIG. 1;
FIG. 3 is an enlarged sectional view taken generally along line 3--3 of FIG. 2;
FIG. 4 is an enlarged sectional view taken generally along line 4--4 of FIG. 2;
FIG. 5 is a side view, partly broken away and partly in section, of the plate of FIG. 2;
FIG. 6 is a plan view of a stop member used in the mechanism of FIG. 1;
FIG. 7 is a sectional view taken generally along line of 7--7 of FIG. 6;
FIG. 8 is a plan view of the mechanism of FIG. 1 in assembled relation shown in an adjusted setting for a maximum timing cycle; and
FIG. 9 is a view similar to FIG. 8 showing that mechanism in an adjusted setting different from that illustrated in FIG. 8.
Detailed Description of a Preferred Embodiment
FIG. 1 illustrates a timer 10 having a casing 12 within which is mounted a clock mechanism, not shown, which will be understood to have a conventional main spring and timer cam assembly which may be actuated by a setting shaft 14. Shaft 14 is rotatable clockwise from a timed-out position for winding the spring motor and is rotatable counter-clockwise by that spring motor during a period of runout to the timed-out position.
The timer mechanism may be provided for different purposes to serve as a time switch for a given operation. For example, a pair of electrical contacts, not shown, may be closed, upon clockwise movement of timer setting shaft 14 into a desired position for setting the clock mechanism, and remain closed during a period of runout. Upon reaching the timed-out position, the timer mechanism operates to move the contacts to an open position.
Casing 12 of the timer mechanism includes terminals, not shown, to which wires 16 and 18 are attached with terminal screws 20 and 22, and the wired timer 10 is then inserted into a suitable receptacle, such as the illustrated wall outlet box 24 and secured in position by a pair of screws 26, 28 extending through apertured straps 30, 32 on casing 12 and into openings 34, 36 in upper and lower ears 38, 40 on box 24.
To provide a time scale, a suitable dial is provided on an exposed side 42A of a wall or face plate 42 with time scale indicia, and plate 42 is provided with an aperture 44 to receive timer setting shaft 14.
To ensure that face plate 42 is positively maintained in properly aligned relation to outlet box 24 and timer casing 12, a plurality of openings 46, 46A and 48, 48A are formed in face plate 42 to provide detents extending in a direction opposite that of exposed side 42A of plate 42 for engagement with opposite sides of timer casing 12. As best seen in FIGS. 3 and 4, detents such as 48, 48A are formed to protrude and thus engage an adjacent side of casing 12 and restrain face plate 42 against undesired lateral movement relative to that casing such that face plate 42 is in retained properly aligned operative position relative to timer casing 12.
In the specifically illustrated embodiment, a timed-out position is indicated by the numeral zero which in the illustrated embodiment is at a twelve o'clock position (FIG. 2). The time scale for selecting the runout cycle is indicated on the dial by suitable indicia which in the illustrated embodiment is provided by equally spaced apart radial lines which emanate from the center of face plate aperture 44 with suitable numerals identifying alternate lines. A maximum time setting is at an eleven o'clock position which will be understood to be identified by a radial line 50 midway between lines identified by the number ten and numeral zero.
In accordance with one feature of this invention, a locating stud 52 is fixed to protrude from face plate 42 in radially aligned relation with the center of face plate aperture 44 and with the numeral zero at a predetermined radial distance from the center of face plate aperture 44 as best seen in FIG. 2. To provide adjustment of a presettable time cycle, while at the same time ensuring that the time cycle is not readily user adjustable, a stop member is provided in the form of a disk 54 shown mounted in overlying relation to face plate 42 and having an aperture 56 corresponding to face plate 44 aperture for receiving timer setting shaft 14 which will be understood to extend through both apertures 44, 56. A plurality of stud receiving openings such as at 58 are illustrated as being formed in disk 54 with the centers of each of the openings being located on an arc spaced from the center of disk aperture 56 at a radial distance which corresponds precisely to that of the predetermined radial distance at which locating stud 52 is disposed relative to the center of face plate aperture 44.
More specifically, in the illustrated embodiment, ten openings such as at 58 are formed in disk 54 with the centers of the openings equiangularly spaced apart along the arc in predetermined corresponding relation to the time scale indicating dial of the face plate 42. As best seen in FIGS. 6 and 7, disk 54 includes a protrusion or stop 60 staked to a rim of disk 54. Stop 60 is spaced apart in a clockwise direction, as viewed in the drawings, a preselected angular distance A from the center of stud receiving opening 58A of disk 54. The centers of the other stud receiving openings of disk 54 (FIG. 6) are located along the above mentioned arc extending in a counter-clockwise direction between opening 58A and stop 60 at a common radial distance from the center of disk aperture 56 and with the center of each disk opening being spaced at a common predetermined angular distance from the next adjacent disk opening.
In accordance with this invention, the common predetermined angular distance between adjacent disk openings 58 corresponds to adjacent time scale indicia noted above as being provided on the face of plate 42. As described, stop 60 is fixed to project from the rim of disk 54 radially outwardly of the arc on which the stud receiving openings 58 are located.
By virtue of the above described construction, a winding knob 62 may be readily mounted on timer setting shaft 14 in overlying non-interfering relation to disk 54 and locating stud 52, the knob 62 being provided with an indicating pointer 64 which cooperates with the face plate dail for indicating time. Accordingly, disk 54 may be adjustably fixed relative to the face plate dial upon first fitting disk 54 on face plate 42 before assembling knob 62, and by aligning a preselected hole 58 in the movable disk 54 with locating stud 52 so as to position stop 60 in spaced relation to the zero or timed out position on the dial at a desired time setting as indicated by indicia on the dial of face plate 42. The stop 60 of disk 54 preferably is not precisely aligned with the indicia but rather is at an offset angular distance B (FIGS. 6, 8 and 9) which compensates for indicating pointer 64 of the setting shaft winding knob 62 which then may be directed precisely toward indicia establishing a preselected time cycle as determined by the adjusted position of disk 54, upon manually moving the winding knob pointer 64 into engagement with the protruding stop 60 of the adjustable disk 54. To provide such engagement, the winding knob pointer 64 is dimensioned to extend beyond the stud receiving openings formed in disk 54 such that upon moving pointer 64 into engagement with stop 60, the spring motor is wound to initiate a predetermined period of runout indicated by the face plate dial.
When the adjustable disk 54 is angularly positioned with stop 60 in a desired location, it will be seen that the face plate stud 52 cooperates with the setting shaft 14 received in apertures 44 and 56 of face plate 42 and disk 54, respectively, for affixing disk 54 and its stop 60 in a predetermined angular position relative to face plate 42 with stop 60 of disk 54 being in interfering relation to the winding knob pointer 64 for setting a predetermined time runout cycle. Thereafter, the above mentioned components are preferably secured in assembled relation to one another by a self-threading nut 66 (FIG. 1) which is threadably engaged with an inner shank 14A of the timer mechanism setting shaft 14, and the manual knob 62 is then simply pushed onto shaft 14 to engage it with a friction fit and in registration with the timed-out position indicia on face plate 42 with the timer mechanism in its off position.
Upon restoring power at a breaker or fuse panel, the timer 10 then may be operated. It will be noted that stop 60 and disk opening 58A, separated by the preselected angular distance A, cooperate to establish an adjusted minimum presettable period of runout when disk 54 is mounted with stud 52 received in disk 58A. Likewise, an adjusted maximum presettable period of runout is established when disk 54 is mounted with the face plate stud 52 received in disk opening 58B next adjacent stop 60. As illustrated, disk opening 58B is remotely disposed along the above mentioned arc from disk opening 58A (FIG. 8). Intermediate adjusted positions of disk 54 may be established to preset intermediate time runout cycles. For example, an intermediate setting is illustrated in FIG. 9 wherein disk opening 58C (FIG. 6) will be understood to receive stud 52 protruding from the face plate 42 such that stop 60 is in downstream adjacent relation to the time setting indicated by the numeral six whereby the winding knob 62 may be brought into engagement with stop 60, thereby to preset this particular desired period of runout.
As will be apparent to persons skilled in the art, various modifications, adaptations and variations of the foregoing specific disclosure can be made without departing from the teachings of this invention.