US 3823547 A
In a timer comprising a dial, a progress pointer rotatably mounted about an axis generally perpendicular to the dial, a first manually adjustable stop means for limiting movement of the progress pointer in a first direction, spring means for driving the pointer in the first direction, and selectively actuable means for driving the pointer in a second direction opposite to the first direction, there is provided an improvement in the manually adjustable stop means. This improvement is a generally circular element having a periphery and a mounting element having a periphery, whereby the peripheries combine to form a generally cylindrical joint concentric with the axis. The circular element carries an abutment means for limiting movement of the pointer and the peripheral joint is spaced outwardly a substantial distance from the axis so that the dial and pointer may be easily viewed without obstruction. In addition, there is provided an improved progress counter having a means adjacent its hub for absorbing energy during impact of the pointer with the movable abutment.
Description (OCR text may contain errors)
United States Patent [191 Hulterstrum et al.
[ RESET TIMER  Assignee: Gulf Western Industries, lite, New
 Filed: Feb. 7, 11973  Appl. No.: 330,329
 US. Cl. 58/395, 200/38 A  int. Cl. G041) 29/00  Field of Search... 116/1365, 124.1 A, 124.1 R, 116/1242 R, 124.2 A, 124.3; 200/38 R, 38
F, 38 A; 58/395, 126 R, 126 D, 34
 References Cited UNITED STATES PATENTS 3,225,151 12/1965 Lagasse 200/38 A 3,568,429 3/1971 Lille 58/395 3,693,119 9/1972 Nakama et al 200/38 R 3,725,616 4/1973 Pearson 200/38 R FOREIGN PATENTS OR APPLICATIONS 1,269,706 1960 France 1l6/DIG. 6
1,392,416 1964 France l16/DIG. 6
I Primary Examiner-Richard B. Wilkinson Assistant Examiner-U. Weldon Attorney, Agent, or Firm-Meyer, Tilberry & Body [5 7] ABSTRACT In a timer comprising a dial, a progress pointer rotatably mounted about an axis generally perpendicular to the dial, a first manually adjustable stop means for limiting movement of the progress pointer in a first direction, spring means for driving the pointer in the first direction, and selectively actuable means for driving the pointer in a second direction opposite to the first direction, there is provided an improvement in the manually adjustable stop means. This improvement is a generally circular element having a periphery and a mounting element having a periphery, whereby the peripheries combine to form a generally cylindrical joint concentric with the axis. The circular element carries an abutment means for limiting movement of the pointer and the peripheral joint is spaced outwardly a substantial distance from the axis so that the dial and pointer may be easily viewed without obstruction. In addition, there is provided an improved progress counter having a means adjacent its hub for absorbing energy during impact of the pointer with the movable abutment.
ti- Claims, 7 Drawing Figures RETURN PAIENIED m I s we WH1M3 PATENIEnwswH 'a 'wszmm SHEET 3 BF 3 RESET TIMER This invention relates to the art of electrical timers of the type used in controlling manufacturing processes, and more particularly to an improved timer for this purpose.
The invention is particularly applicable for a reset timer of the type having a pointer indicating the set time of the timer and a progress pointer indicating the remaining time during a timing cycle, and it will be described with particular reference thereto; however, it is appreciated that the invention has broader applications and may be used in various reset timers of the type having a progress pointer for indicating the remaining time in the timing cycle.
When process or machine operations are to be timed, it is somewhat common practice to use a reset timer which includes a front dial having two pointers. A set pointer is manually adjusted to set the timing cycle of the timer, and a progress pointer is provided to indicate the remaining time for a given timing cycle. The position of the manually adjustable set pointer positions a stop against which the progress pointer comes to rest by a spring return action. When the timer is actuated to time a given cycle, a clutch engages a synchronous motor with the driving train of the progress pointer so that the progress pointer is driven in a direction away from the adjusted stop and against the spring action. When the progress pointer has progressed to a zero remaining time on the cycle, a switch is actuated to disengage the motor from the progress pointer so that the progress pointer can be again spring returned to a position determined by the adjusted position of the set pointer and its associated stop. I
Various reset timing mechanisms for providing the selective driving and spring return of the progress pointer have been developed and are now used. The present invention more closely relates to the reset timer shown in prior U.S. Pat. application Ser. No. 165,142 filed July 22, 1971 now U.S. Pat. No. 3,725,616. This prior application is incorporated by reference herein. When the progress pointer is spring biased into engagement with the adjustable stop controlled by the set pointer, the inertia of the drive train for the progress counter causes a relatively high impact between the progress pointer and the stop. This may shift the stop and somewhat change the timing cycle.
These difficulties have been overcome in the prior art by providing selective locking devices on the adjustable stop or by increasing the force necessary to change the position of the stop. These arrangements either require an additional mechanism or a relatively high manual force necessary to reset the timing cycle of the timer. These disadvantages have been overcome by the present invention which relates to a reset timer wherein the adjustable stop is controlled by a one piece circular ele ment that holds the stop stationary and allows easy adjustment. In addition, the progress pointer incorporates an energy absorbing structure.
ln accordance with one aspect of the invention, the progress pointer has a base portion adjacent the pivotal axis and a tip portion at its free end. At the base portion, there is provided an arcuate groove surrounding the axis and defining a connecting bridge portion which is on the opposite side of the axis from the tip portion of the pointer. In this manner, the bridge portion between the portion of the pointer fixedly secured to the drive gear train and the portion of the pointer actually carrying the tip portion form a resilient interconnection between these two portions of the pointer. The progress pointer is an integral plastic structure which enhances the resiliency of the interconnecting bridge portion and reduces the weight of the pointer to reduce the inertia of the pointer during movement against the adjustable stop.
The prior reset timers generally included a knob in the center of the dial which supports the manually adjustable stop and the set pointer. By rotating the knob, the stop and set pointer are changed to set the cycle length of the timer. This knob is journalled on the structure which carries the progress pointer and required an opening in the clear lens over the timer dial. ln addition, the stop is spaced outwardly from the knob, generally on the outer portion of the set pointer. Consequently, there is a mechanical advantage between the center hub for the knob and the stop on the set pointer, which would magnify the torque created by engagement of the progress pointer with the stop during its spring return. To assure that the timing cycle was not changed, a strong frictional joint is provided or a positive lock is used to inhibit inadvertent movement of the stop by the returning progress pointer.
The present invention overcomes these disadvantages and greatly simplifies the manual adjusting mechanism of a reset timer. In accordance with the invention, the manually adjustable stop means includes a generally circular element having a periphery and a mounting element having a periphery, the peripheries combined to form a generally cylindrical bearing joint concentric with the axis of the progress pointer. The abutment or stop means is provided on the circular element for limiting movement of the progress pointer in the spring return direction. The circular element includes a wide area opening within the outer bearing joint to expose both the dial and the progress pointer. This greatly simplifies the setting structure and provides easy reading of the dial and progress pointer. To indicate the position of the stop, a lens over the opening inside the bearing joint may be provided with a set pointer outline corresponding to the position of the adjustable stop when the circular element is rotated to a selected timing cycle.
The primary object of the present invention is the provision of a timer of the type having a progress pointer movable in a first direction by a synchronous motor and a manually adjustable stop for limiting the movement of the progress pointer in the first direction, which timer reduces the shock when the pointer engages the stop and simplifies the manually adjusting structure.
Another object of the present invention is the provision of a timer of the type having a progress pointer movable in a first direction by a spring and driven in a second direction by a synchronous motor and a manually adjustable stop for limiting the movement of the progress pointer in the first direction, which timer has an energy absorbing progress pointer.
Another object of the present invention is the provision of a timer as defined above which has a manual adjusting structure that reduces the tendency of move ment of the stop without undue friction or a special mechanical lock.
Yet another object of the present invention is the provision of a timer as defined above which has a manually adjustable structure that allows clear reading of the dial and provides a mechanical advantage to the operator in the manual setting procedure.
These and other objects and advantages will become apparent from the following description taken together with the accompanying drawings in which:
FIG. 1 is a pictorial view illustrating the preferred embodiment of the present invention;
FIG. 2 is an enlarged cross-sectional view taken generally along line 22 of FIG. 1;
FIG. 2A is a partial cross-sectional view taken generally along line 2A-2A of FIG. 2;
FIG. 3 is a cross-sectional view taken generally along line 3-3 of FIG. 2;
FIG. 4 is a pictorial view of a progress pointer constructed in accordance with the present invention;
FIG. 5 is a view taken generally along line 5-5 of FIG. 4; and,
FIG. 6 is a view taken generally along line 6-6 of FIG. 2.
Referring now to the drawings wherein the showings are for the purpose of illustrating a preferred embodiment of the invention only and not for the purpose of limiting the same, FIG. ll illustrates a reset timer A including a casing 10, a mounting base 12, a manual setting mechanism 20, a progress pointer 22, an adjustable stop 24 carried by the setting mechanism, and a set pointer 26. As in standard reset timers, the progress pointer 22 is spring returned to the stop 24 for cycling. Thereafter, the progress pointer is driven by a motor away from stop 24 toward the timed out position. Pointer 22 moves over an arcuate segment or sector and stop 24 is positioned in this segment or sector to limit movement of the pointer in the spring return direction. The present invention relates to an improvement in this type of reset timer.
In accordance with the illustrated embodiment of the invention, the driving mechanism for progress pointer 22 is constructed substantially in accordance with prior US. Pat. application Ser. No. l65,l42 filed July 22, 1971 now US. Pat. No. 3,725,616. This description is incorporated by reference herein. In accordance with this prior disclosure, there is a motor 30 connected by a drive shaft 32 with a clutch mechanism 34 including a rotatable element 40 drivingly connected to shaft 32 and a journalled element 42 freely rotated about the axis of the motor drive shaft. Coil spring 44 coacts with a collar 46 for biasing the element 40 against clutch element 42. These elements each have a series of teeth 40a, 42a 0 which drivingly connect elements 40, 42 when a clutch operating solenoid 50 actuates its armature 52. A clutch arm 54 is pivoted by armature 52 for the purpose of engaging the clutch elements 40, 42. Switch 56 is a normal switch associated with the solenoid 50 and may be used for energizing motor 30 to initiate a cycle time when the solenoid 50 is actuated. Connected onto a movable clutch element 42 is an axially extending arm 60 having set screws 62, 64 adapted to engage sequentially operated switches 66, 68. These switches form the timed out point or position of the progress pointer 22 and can be used to de-energize solenoid 50 and motor 30. In essence, the switches limit the progress pointer movement in the motor driven direction and form a stop means for this movement. As so far described, the structure is substantially similar to the structure illustrated in the previously mentioned patent application.
A gear is joumalled about the motor axis and is connected to arm 60 by a connector 72. This gear is meshed with a pointer gear including a stop 82 which engages the motor shaft or clutch assembly to limit the maximum movement of the two gears in the direction which allows arm 80 to actuate switches 66, 68. A clock type spring 84 has one end secured onto the mounting base 12 and the opposite end secured to a spring plate 85 formed integrally with gear 80. This spring is the return spring for the progress pointer 22 and biases the progress pointer in the direction indicated in FIGS. 1 and 3, which is the direction of movement of the pointer 22 toward adjustable stop 24. Gear 80 and plate 85 are a one piece plastic structure which reduces the inertia of the drive train for progress pointer 22.
When clutch 34 is engaged and motor 30 is driven, clutch element 40 engages clutch element 42 to drive the arm 60 toward switches 66, 68. At that time, the gear 70 connected to arm 60 drives pointer gear 80 to rotate the pointer 22 from the adjustable stop 24 toward the timed out position of the timer. Thereafter, the clutch 34 is disengaged and spring 84 rotates gear 80 to return the pointer 22 to a position engaging adjustable stop 24. At the same time, spring 84 returns the arm 60, which is in the drive train of pointer 22, to its start position for a subsequent cycle.
In accordance with the illustrated embodiment of the invention, the mounting base 12 is formed from a plastic. To add rigidity to the structure, there is provided a metal plate within the recess formed in the mounting base. The outer surface of this metal plate includes the dial 92 which has a maximum range indicated by the numerals on the face of the dial.
In accordance with the basic aspect of the present invention, there is provided an improved mechanism for adjusting the position of the stop 24 to change the arcuate distance travelled by the progress pointer 22 during the timing cycle. Although various structures could be used to practice the present invention, the preferred embodiment of the present invention includes a cupshaped member I60 formed of a clear plastic material and having an outer circular element or ring 102 terminating at a circular rim 104. By turning the cup-shaped member 164), which carries stop 24, the cycle length of the timer can be changed. Only the circular element or ring carrying stop 24 and its rotational mounting structure is required for this aspect of the invention; however, in accordance with the preferred embodiment of the present invention, the cup-shaped member includes a lens 106 which is formed of clear plastic and extends over the dial 92 so that the dial and pointer 22 are clearly visible to an operator. The lens covers the opening defined by the ring 102 and allows an unobstructed view of the dial 92. This improvement does not require a central knob which obstructs the view and requires a more complicated joumalling structure. The set pointer 26 is hot stamped onto lens 106 with the active side 109 of stop 24 corresponding to the tip 109a of the set pointer. Consequently, the set pointer formed in lens 106 points to the adjusted position of stop 24 at all times. This gives a visual representation of the cycle length for the timer and can be used in conjunction with the dial 92 for reading the adjusted cycle length of the timer A. Extending outwardly from rim 104 there is provided a stop 110, best shown in FIG. 6, that coacts with spaced abutments 112, 114 to limit the rotation of ring W2 to an angle less than 360. This prevents the setting of the set pointer to a position greater than the time on the dial. Stop llllfi engages abutments I112, lllldso that the stop 24 can be adjusted between the timed out position and the maximum position on dial 92. These two positions are spaced apart a few degrees at the top of the dial. Referring now more particularly to FIG. 6, there is provided a leaf spring 11% supported upon spaced abutments M2, Ill ll and engaging the outer periphery of rim MM. This spring prevents vibration of the cup-shaped member MM) and may add slightly to the holding force of the ring W2 when it is adjusted into a selected position.
To mount the cup-shaped member MW for rotation about the axis of pointer 22 and with respect to the dial of timer A, there is provided a bezel INT which has a circular, central opening engaging an outer periphery ring 1102. A plurality of holes I32 are used for securing the bezel onto mounting base 112. As shown in FIG. 2, the bezel includes an outer rim 11% having a square configuration matching the internal opening of the mounting base 12. A cylindrical bearing joint is formed between the generally cylindrical bearing surfaces M llt, M2 which are the cylindrical surfaces that define the opening within bezel 13b and an outer periphery for ring I02. Of course, the joint between the cylindrical bearing surfaces could be formed at various positions on cup-shaped member Iltltl without departing from the intended spirit and scope of the present invention. It is noted that the bearing joint for the manually adjustable mechanism is outwardly of the center hub W so that the opening within ring W2 has no mounting structure. An operator can grip a gripping means Wfi provided on the outer surface of ring W2 for rotation of the member ttltt to position the adjustable stop 24. The gripping means could take various forms; however, in accordance with the illustrated embodiment of the invention, it includes a plurality of serrations around the periphery of ring W2. Rotating force is applied at a position spaced outwardly from the center of cup-shaped member Iltltl; therefore, there is a mechanical advantage gained in moving the ring MP2. Also, the clear plastic lens 11% allows easy vision of the dial 92 and pointer 22, as previously mentioned. In accordance with the invention, the joint between bearing surface Mid, M2 is near the outer portion of dial 92. The stop M could be positioned radially inwardly from the bearing joint at various positions on lens or wall Iltlti. In accordance with the illustrated embodiment, the stop M is positioned adjacent to the bearing joint. Of course, if the pointer 22 is long enough, the stop could be slightly outside the bearing surfaces. The present invention clearly distinguishes over the prior art wherein the manually adjustable setting means is a knob at the center of the dial. Such an arrangement required a substantial amount of force to move the pointer 24 and also requires more friction force to prevent movement of the stop 2% during repetitive cycles.
In essence, the stop 2d forms a manually adjustable stop and the switches or, 068 form what would be considered a somewhat fixed stop. The cycle length is defined by the spacing between these two stop means although they are not in juxtaposed relationship with each other.
Referring now to FIG. 4, another aspect of the present invention is illustrated. In accordance with this aspect, the progress pointer is an integral plastic structure which reduces the inertia of the pointer. In addition, the pointer includes a base portion having a square hub 152 for securing the pointer onto pointer drive shaft $6. A tip portion 11541 is the portion which indicates the position of the pointer. This portion engages the stop 2 for the purpose previously described. Of course, the tip portion may be extended so that the stop can be moved outwardly a slight distance. In that case, the pointer itself is basically that portion of the pointer which can be viewed with respect to the dial and through lens 11%. An arcuate slot llfitl defines a bridge 1162 which is diametrically opposite to the tip portion 1154i and allows an energy absorbing springing action when the tip portion of the pointer engages stop 24. In accordance with the preferred embodiment of the invention, the bridge portion is formed in a disc shaped section of the pointer having a thickness of approximately 0.09 inches and an outer diameter of approximately 0.75 inches. In this embodiment, slot has a thickness of approximately 1/16 inch. The bridge portion has a thickness of approximately /a inch. By using these dimensions, a sufficient energy absorbing arrangement is provided for the progress pointer 22.
Having thus defined our invention, we claim:
11. In a timer comprising a housing, a dial supported on said cover plate, a progress pointer rotatably mounted to rotate in a given plane and about an axis generally perpendicular to said dial, a first manually adjustable stop means for limiting movement of said progress pointer in a first direction, spring means for driving said pointer in said first direction, and selectively actuatable means for driving said pointer in a second direction opposite to said first direction, said manually adjustable stop means including a manually rotatable element, means for mounting said element on said housing for rotation about said axis, means for holding said element at any angular position with respect to said axis and a stop carried by said element and protruding into said given plane, the improvement comprising: said manually rotatable element includes a central opening concentric with said axis, a radially outwardly facing cylindrical surface concentric with said axis, a shoulder adjacent said radially outwardly facing cylindrical surface, said shoulder having an axially facing fiat surface lying in a plane perpendicular to said axis and facing away from said housing, and a cylindrical flange concentric with said axis, facing toward said housing and defining a rearwardly facing, cylindrical bearing surface concentric with said axis; said mounting means includes a cover plate having a rearwardly facing surface perpendicular to said axis and a circular opening defining a radially inwardly facing cylindrical surface matching said radially outwardly facing cylindrical surface and concentric with said axis, said radially inwardly facing cylindrical surface surrounding said radially outwardly facing cylindrical surface to define a bearing interface for rotatably supporting said manually rotatable element, and means for clamping said cover plate to said housing with said rearwardly facing surface of said cover plate engaging said axially facing flat plate and forcing said rearwardly facing, cylindrical bearing surface against said dial to secure said rotatable element in an axial direction; said stop means being an abutment extending from said rotatable element into said given plane; and said holding means including a spring means supported on said housing and biased against said manually rotatable element.
2. The improvement as defined in claim 1 wherein said pointer is an integral plastic structure having a base portion and a tip portion, said base portion of said pointer including a first section generally rigidly connected with respect to said pointer driving means, a second section generally rigidly connected to said tip portion, and a bridge portion connecting said two sections, said bridge portion being located solely on the side of said axis opposite to said tip portion to provide a resilient connection between said sections whereby energy is absorbed when said pointer contacts said abutment on said manually movable element.
3. The improvement as defined in claim 1 including a transparent wall covering said central opening and spaced axially from said progress pointer, and a set pointer on said transparent wall and adjacent said abutment whereby the angular adjusted setting of said manually adjustable element is visible.
4. The improvement as defined in claim 1 including a second abutment extending outwardly from said manually adjustable element and a third abutment fixed with respect to said cover plate, said second abutment means having a plane of movement as said adjustable element is rotated and means for mounting said third abutment means in said plane of movement of said second abutment means whereby said adjustable element can move through an arc of less than 360.
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