US 3749354 A
This invention deals with a push-push snap mechanism in an electrical switch, in a valve and other applications snap mechanism consisting of a stem and a resilient cup, with two related positions. The stem carries the moving contacts, which are bridging stationary contacts. The junction lines of stem with bottom of cup and of bottom of cup with walls of cup are undercut and form hinges. The valve stem carries flexible lips which seal the valve preventing fluid leakage, and also seals the valve ports until the snap occurs (when so programmed).
Claims available in
Description (OCR text may contain errors)
United States Patent 1 Raitport July 31, 1973 [5 SNAP MECHANISM FOR USE IN 3,264,884 8/1966 Brooker 267/159 x ELECTRICAL SWITCHES, FLUID: 3,609,266 9/1971 Raitport 200/ 159 B 3,582,594 6/1971 Twyford 267/ 159 X SWITCHES, VALVES, ETC.
Eli Raitport, 1807 Mower St., Philadelphia, Pa. 19152 Filed: Apr. 5, 1971 Appl. N0.: 130,939
Related U.S. Application Data Continuation-impart of Ser. No. 821,547, April 18, 1969, Pat. No. 3,609,266.
References Cited UNITED STATES PATENTS 9/1953 Engstrum 251/75 Primary Examiner-Henry T. Klinksiek  ABSTRACT This invention deals with a push-push snap mechanism in an electrical switch, in a valve and other applications snap mechanism consisting of a stem and a resilient cup, with two related positions. The stem carries the moving contacts, which are bridging stationary contacts. The junction lines of stem with bottom of cup and of bottom of cup with walls of cup are undercut and form hinges. The valve stem carries flexible lips which seal the valve preventing fluid leakage, and also seals the valve ports until the'snap occurs (when so programmed).
12 Claims, 21 Drawing Figures A PATENTHJ 3. 749 354 SHEET 1 BF 4 INVENTOR:
PATENIED JUL 31 I975 SHEET 4 [IF 4 IIIIIIIIVIAIIII 7/ III //IIIIIIIIIIIIII I68 INVENTOR SNAP MECHANISM FOR USE IN ELECTRICAL SWITCHES, FLUIDIC SWITCHES, VALVES, ETC.
This application is a continuation in part of application, Ser. No. 82l,547, filed Apr. I8, I96), now U.S. Pat. No. 3,609,266.
The purpose of these improvements is to provide full proofness for the double throw push-push switch of the original invention and provide longer life for its springs, and to provide sealing means for said snap mechanism when it is used in a valve. During pretravel times, the valve will stay closed or open, when opening the valve or closing it respectively.
FIG. 1 depicts a sectional view of hereby improved electrical switch with closed contacts.
FIG. 2 depicts a sectional view of same switch with open contacts. Both said views are in relaxed positions.
FIG. 3 is a section along lines 3-3 of FIG. 7.
vFIG. 4 is a section view along lines 4-4 of FIG. 7-7.
FIG. 5 depicts the switch of FIG. I just before it snaps from close to open position (FIG. 1 into FIG. 2).
FIG. 7 depicts the said switch just after it snapped from close to open; in other words, it is the subsequent position to that demonstrated in FIG. 5.
FIG. 6 depicts the switch in open position, subjected to aforce depressing the cup which eventually will cause the switch to snap into the closed-circuit posi- FIG. 8 depicts this switch in a position subsequent to FIG. 6 when it is ready to snap into close-circuit position.
FIG. 9 depicts the use of this innovated snap mechanism in a valve in the open circuit position.
FIG. 10 depicts this snap mechanism in a valve in the close-circuit position.
FIGS. 11 and I2 and I3 depict the valve in transition from open to close position demonstrating the flexing of the lips.
FIG. 14 depicts this snap mechanism in a valve just before snapping from open to close position.
F I68. 17, I5 and I6 depict the valve in transition position from close to open illustrating the flexing of lips and sealing of the ports'during pretravel.
FIG. 17 depicts'this snap mechanism in a valve just before snapping from-close to open position.
FIG. 18 depicts a modified design of the loop spring switch in a released position.
FIG. 19 depicts said switch of FIG. 18 in a pre-snap position. 1
FIG. 20 depicts said switch of FIG. 18 in actuated position after snap. All views are shown in sections.
FIG. 21 depicts the switch of FIG. 18 along lines 2I-2I.
In FIGS. 1-8, the improvement in this switch over that claimed in the original application filed on Apr. I8, I969, consists of slits (undercuts) I13 and 105 in conical cup shape I03; and recesses I21 and 102 in cup 101. The above splits would facilitate continuous flexing of I16 (bottom portion of conical shape) and prevent fatigue of material at junction points 112 and 117. Recesses 102 and 104 guides the top of conical shape I03 and junction 112 between walls or bottom of cup, respectively in such a way that cone 103 reaches cup 101 at one level when snap mechanism snaps from position shown in FIG. I to that shown in FIG. 2 and same cone I03 reaches cup IOI at another level when the mechanism snaps vice-vcrsa. In other words, in FIG. 1,
the bridge-contact 114 is bridging contacts 118 and 119. The conical shape I03 intimately supports cup 101. Whenforce is applied to the cup 101, it depresses the perimeter of the conical cup 103 down, causing the bottom 116 to pivot about the ring 106 and raise stem 110; bottom of cone 116 becomes compressed and buckles because there is not enough space in cup-cover 101 for developed area of I 16, when 116 is in the horizontal position (see FIGS. 5 and 7).
Therefore, I16 stores energy and as soon as stem I10 raises junction line 117 above the level ofjunction line 112, the stored energy in II6 snaps the stem 110 up, cutting the contact of bus I14, and also lifting up cup 101 (FIG. 2). Now the circuit between terminals 118 and 119 is open and the switch is stable. However, the snap mechanism reversed itself.
During its motion, the cover 101 is guided by means of projections 109 protruding from the body 120 into the slots 122 of the cover-cup 101.
In order to reverse the position of the switch back to closed contact as it was inFIG. I, the cup-cover 101 would be depressed in the same manner as in aforeexplained case. However, at this time, stem 110 would (FIG. 2) be depressed rather than cone 103. This would cause the bottom 116 of the cone 103 to pivot as well (FIG. 6). Then the horizontal projection of bottom 116 increases as the angle between the horizontal axis and bottom of cone I16 decreases. This causes the walls of cone 103 to interfere with high points 104 of cup-cover I01. Subsequently, said up-right walls fold at the thinned section and junction 112 moves into recess I21. Bottom 116 of cone 101 is also buckling (FIG. 6), storing energy. Further, the cover-cup 101, continues to depress item 110, so edge of up-right circumference of the cone 103 slips into recess 102 (FIG. 8). Further depression of cup-cover I01 causes folding and buckling of cone 103 due to the geometrical curve of recess I02. Simultaneously, stem continues its pretravel toward the downward snap (see FIG. 17). By that time, junction point I I7 is lower from the junction points 112; in other words, the snap mechanism crossed the center. Now, should the force on the switch be released, the conical shape I03 willsnap into a relaxed position such as in FIG. 1, closing the contacts 118 and 119; it would snap because of the built-up energy in elastic deformation of cone 103. It cannot snap back into position of FIG. 2, because forthat the junction line 117 would have to pass back through the plane in which junction line 112 is located. In that plane takes place maximum compression of diaphragm 116. Since after the actuating force is released, the cone 103 will snap only in such direction in which it will progressively relax, it will snap into position of FIG. 1. Note that until it snapped, the contact 114 did not reach contacts 118 and 119. In other words, the make of circuit takes place only after snap, and so is the break" of the circuit.
The travel of the cup-cover is limited by the upper limit 107 of the slot 122; when limit 107 reaches projection 109, the cup-cover I01 cannot move downward any more, thus preventing undesirable reverse of the through of the switch. 123 is a hole in cup 101 for cir-.
culation of air in order to prevent vacuum within the cup-cover I01. I24 is a projection from cup-cover 101; it makes the recess I02 deeper which so delays the contact of cup 101 with cone I03, while the projection 124 is maintaining intimate contact with stem I10.
FIGS. 9 to 17 illustrates the use of this innovated and improved snap mechanism in a valve. The valve has innovated seals such to keep the valve in the same functional position relative to the circuit (open or close) while pretravel and over-travel of the snap mechanism. It consists of several flexible lips molded integrally with the spool. The lips take up one position relative to the' of open position. In FIG. 10, lip 137 seals the ports 132 and 139 and so cuts off the flow.
In FIG. 9, the lip 135 is sealing off the bottom portion of the body preventing fluid spillage. O-ring 141 is sealing off the upper portion of the body. Lips 136 and 137 are inactive in this position.
In FIGS. 11, 12 and 13 and 14 this valve is shown in transition from its open to closed position. As the spool 130 is raising (in the same manner as stem 110 aforeexplained), the lip 135 gets caught in groove 133 while the spool 130 continues to rise and, therefore, lip 135 becomes inverted as shown in FIG. 12. As the spool 130 moves up, the lip 135 ceases to seal bottom portion of the body; however, simultaneously, lip 136 moves up from recess area 142, folds over the shank 140 and seals the gap between the shank 140 and walls of the body 143. Gradually, the flow passage is transferring itself from the top of lip 135 to underneath of lip 135. Note that the flow is not interrupted, since at some point, the flow passage is in both above and underneath the skirt 135, because lip 135 is narrower than groove 133.
In FIG. 14, the pre-snap position, the lip 135 almost moved out of the groove 133, and lips 136 and 137 are ready to move and seal the ports 132 and 139 and the groove 133, which causes the valve to actuate into the closed position as shown in FIG. 10. FIGS. 15 to 17 depict the various transition positions of this valve from closed to open of said ports 132, 139. In order to switch this valve into the open position, meaning from FIG. 10 into FIG. 9, the cup cover 101 is depressed also as explained before. Then the spool pulls down junction line 144 of the lip 137 by which the lip 137 is joined to the spool 130, while the free edge of lip 137 is caught by ring 134.
FIG. 15 illustrates the inverting of lip 137 which enables to keep the valve closed, the time of pretravel. Depression of cover 101 causes depression of spool 130; however, lip 137 is caught by ring 134 and therefore it starts to fold and invert as the spool 130 continues to pull down. FIGS. 15 and 16 are sectional views of the valve with the lips illustrating the consecutive positions of the lips and their inversion, until the valve snaps open.
Lip 136 caught by lip 137 in the groove 133, undergoes same process of inversion as previously lip 137 in FIGS. 11 and 12. Note that lip 137 gradually ceases to seal the ports 132 and 139 and groove I33 and it is replaced by lip 136, then by lip 135.
In FIG. 17 is illustrated the pre-snap position of this valve into the open position. Lips and 136 are scalers in this position. The other lip 137 has slipped down below the groove 133. Then the valve spool 130 will snap down; however, the lip 133 will be interfered with ring 134, and therefore will be reversed into the position shown in FIG. 9.
In FIGS. 18-20 depict a modified design of the switch with a loop spring claimed in the original application filed Apr. 18, I969. This modification is intended to improve the snap action of this switch. In this improved version of the invention, the spring-loop 156 is precompressed in assembly of the switch between projections of the body 157 and 158 which are sloped toward the bottom of the switch. Both sides of the generally rectangular loop spring are also inclined inwardly and are wedging against the sloped projections. So when the spring 156 is further depressed through actuations of the plunger 152, the spring becomes further compressed between projections 157 and 158 which means that the curves 167 and 168 become more compressed; therefore, arms 159 and 160 closing in more toward the center causing curves 172 and 171 also to compress more, as well as semi-loops and 166. The arms 162 and 163 pivot about projections 169 and respectively lifting semiloop 164 to the axis, thus causing curves 179 and 180 to compress (see FIG. 19) ans so is semi-loop 173. Consequently, semi-loops 164 and 165 and 166 and curves 167, 168, 179, 180 all become stressed and relatively a big amount of energy would be stored in so much material (approximately 10 times more than in conventional switches of the same size). When arms 162 and 163 go over center, the spring loop 156 would snap into position shown in FIG. 20. In this position, movable'contact 173 on semi-loop 164 is cut off from stationary contact 172. The moving contact 174 is engaged with stationary contact 176. Semi-loop 166 is just sliding along contact area 175 which is a common terminal. In this position, some of the constrained areas are released. However, since most of the above said semi-loops and curves are constrained, the switch will snap back as soon as the plunger is released. Note that all contacts in this new switch are sliding. During pretravel, the moving contact 173 and 174 are sliding along stationary contacts 172 and 176 respectively. Also, this causes the moving contacts to clean the stationary contacts twice each cycle.
153 and 154 are the stationary alternate terminals. 155 is the common stationary terminal. The body of this switch consists of two pieces 151 and 161. (See FIG. 21). Part 161 is L-shaped. This facilitiates the assembly of this switch. The assembly would be as follows: The Base 1 would be dropped into a cage into a 45 percent position with the vertical axis; then the stationary contacts 153, I54 and 155 would be forced in (or they could be molded in as inserts); then, the loop spring 156 would be dropped in freely. Then plunger 152 would be dropped in top of loop spring 156; then glue would be applied to the L-shaped 161 and it would be dropped in the reverse position also under 45 on top of plunger 152 and body 151. Then pressure would be applied to reversed L-shape 161 at two sides 90 apart. The chamfers on 151 and 161 will guide the pieces together. 161 will push the plunger 152; in turn, the plunger will set the spring 156 between projections 157 and 158 prestressing in it the predetermined amount. This will eliminate human error and experience presently necessary for prestressing springs in snap switches.
1. A valve comprising a body with a longitudinal bore,-a circumferentially extending groove in the bore by the wall of the groove so that the outer portion of 5 the lip trails the direction of movement of the stem thereby sealing the stem with the bore, and means between the stem and the body to reciprocate the stem therein.
2. A valve as in claim 1 including means spaced from the groove sealing the stem with the bore.
3. A valve as in claim 1 including a plurality of spaced flexible lipmeans, each adapted to be flexed by the wall of the groove as the lip means passes thereby.
4. A valve as in claim 1 including snap action means between the body and the stem to reciprocate the stem and means to limit travel of said stem in each direction.
5. A snap mechanism with one biased position comprising a body, a resilient spring-loop of generally rectangular shape a plunger-actuator extending into said body and resting against top of said spring-loop, two spaced projections extending into said body from one said and engaging bottom portion of said spring-loop, two opposite ends of said spring-loop wedging against two sloped projections extending into said body from opposite end walls, whereby movement of said plungeractuator toward said projections cams two spaced ends of said spring-loop toward each other and causes said loop to compress and two sides of said bottom portion of said spring-loop to pivot about said two projections extending into said body from one side lifting toward the top the center portion of bottom of said springloop.
6. A snap mechanism as defined in claim*5 whereas said opposite ends of said spring-loop extending downwardly from said top portion of said spring-loop are sloping down toward each other.
7. A snap mechanism as defined in claim 5 whereas said body comprises an integrally molded L-shaped piece with a cut out for the actuator, whereby said L- shaped piece simultaneously covers two sides of said mechanism.
8. A snap mechanism comprising a stem, a cup having an outer wall extending substantially parallel to the stem, a conical bottom connecting the wall to the stem, the connections adjacent said wall and said stem being of reduced thickness as compared to thickness of the bottom, whereby said bottom can be snapped over center from concave to convex and vice versa, whereby said connections and said bottom are compressed as the bottom goes over center.
9. A device as in claim 8 where said connection between the wall and the bottom is substantially entirely compressed by the wall portion.
10. A device as in claim 8 where the connection between said wall and said bottom is short so that the thicker portion of said bottom bears against said wall as said bottom goes over center.
11. An operator comprising a body portion, a pivot ring extending from one end of the body spaced from the outer edge of the body, a telescoping cover slidably attached to the body, an annular projection on the inner wall of the cover outwardly of the ring and within the outer edge of the body, a concave-convex spring member floatably placed between the ring and the cover, the spring member bearing on the projection.
12. A device in claim 11 wherein at least one recess is provided within the end of the cover opposite to the ring.