US3185901A

US3185901A - Resonant reed adjusting means

Info

Publication number: US3185901A
Application number: US198822A
Authority: US
Inventors: Robert H Voigt
Original assignee: ASCCO Inc
Current assignee: ASCCO Inc
Priority date: 1962-05-31
Filing date: 1962-05-31
Publication date: 1965-05-25
Anticipated expiration: 1982-05-25

Description

May 25y 1965 R. H. volGT 3,185,901

RESONANT REED ADJUSTING MEANS Filed May 5l, 1962 25 {2f} zs/zsn 23A/24 27 -1-/ MM 25 I A 525H f/ 29 @3fm/23A INVEN TOR.

United States Patent O 3,185,901 RESONANT REED ADJUSTING MEANS Robert H. Voigt, Milford, Mich., assignor to Aseco, Incorporated, a corporation of Michigan Filed May 31, 1962, Ser. No. 198,822 6 Claims. (Cl. 317,-182) The present invention relates to resonant reed relays and more particularly to a means for selectively varying the natural resonant frequency of the resonant reed member of such a relay.

In certain copending applications Ser. No. 169,463, filed Ian. 29, 1962 and Ser. No. 179,058 filed Mar. 12, 1962, now Patent No. 3,148,365, issued September 8, 1964, certain signal receiving units are disclosed which employ resonant reed relays. Input signals for such devices have not been absolutely settled, and it might be necessary to adjust the resonant reed to respond to a different signal frequency than that initially decided upon. Also, it has been found in manufacturing these units that it is diicult to mass produce reeds which when installed in the device have the same resonant frequency. There are several reasons for this diiculty. First the Youngs modulus may vary from one heat to another. Secondly it is diicult to fabricate .the reed within the necessary close tolerances to produce precisely uniform results. Third, it is difficult to mount the reeds in a sensing device in such a way as to insure that the effective length of the reed from the clamped or mounted end to the free end will be the same in each unit.

Heretofore various means have been employed to vary the resonant frequency of the reed and thus overcome the above described difculties. One method has been to install a small band around the reed, preferably at the free end, and by moving this band toward or away from the clamped or mounted end the natural resonant frequency of the reed will be varied. This method has proven faulty since the band can readily vibrate out of position. Further such a method is time consuming and therefore expensive insofar as production costs are concerned.

Another method has been to fabricate the reed slightly' longer than the required length and then tile the excess portion away after the reed has been installed. Such a method is also time consuming and therefore unduly expensive.

It is an object of the present invention to reduce manufacturing costs for devices utilizing resonant reed relays by providing a means of quickly and easily adjusting the natural resonant frequency of the reed member of such a relay.

Another object of the present invention is to provide an improved means for varying the resonant frequency of a resonant reed member by providing clamping means which may readily be adjusted to vary the effective length of the reed.

Still another object of the present invention is to increase the utility of devices actuated by an input signal of a predetermined frequency by providing an improved resonant reed relay in which the natural resonant frequency may be adjusted to respond to different actuation signals.

Still further objects and advantages will readily occur to one skilled in the art to which the invention pertains upon reference to the following drawings in which like characters refer to like parts throughout the several views and in which FIG. 1 is a diagrammatic view of an electrical device illustrating one use of the resonant reed embodying the present invention.

FIG. 2 is an elevational side view of a preferred embodiment of the present invention, and

FIG. 3 is an elevational top view of the structure shown in FIG. 2.

Now referring to the drawings for a more detailed description of the persent invention, FIG. 1 illustrates diagrammatically a preferred receiving unit 10 embodying the present invention as comprising an input line plug 11 connected to a resonance circuit 12. The resonance circuit 12 preferably includes a capacitor 13 and an inductor coil 14 which form a series tuned LC circuit. The ca- .pacitive reactance of the capacitor 13 would be approximately the same as the inductive reactance of the inductor coil 14 at a predetermined signal frequency imposed on the supply line through the plug 11 and thus the reactances cancel one another and the circuit is resonant at that frequency.

A resonance relay 15 is disposed Within the magnetic field of the inductor coil 14 and preferably comprises a switch 16 having one contact 17 carried adjacent a resonance reed 1S with the other Contact 19 carried on a leaf 20 pivotally mounted on a hair spring 21.

The receiving unit 10 operates in the manner disclosed in my heretofore mentioned copending patent application Ser. No. 169,463. The actuation signal passes through the inductor coil 14 causing the resonance reed 18 to vibrate at its natural frequency, in turn causing the contact 17 to engage the contact 19. When so resonated, the motion of the Contact 19 is oscillatory at the same frequency due to the hair spring 21, so that the switch 16 remains closed, the contacts 17 and 19 moving together.

Upon the non-interrupting contact of the contacts 17 and 19 an electromagnet 126 is energized to cause an armature 127 and pin 128 to move to permit a uid cell diaphragm 129 to slowly expand. Expansion of the diaphragm 129 causes contacts 132-133-134 to engage, Engagement of the contacts 133-134 closes a circuit through resistors 107-108 and electromagnet 126 so that armature 127 is held in position. Engagement of the contacts 132-133' closes a circuit through the inductor coil 14 to cause a clapper 139 to vibrate to sound an alarm. Engagements of the contacts 132-133 also closes a circuit through a heater winding 140. Contact 134 is preferably a bi-metal heat responsive element so that as the winding heats up and after a predetermined time period the Contact 134 will Warp to the dotted line position illustrated in FIG. 1 to de-energize the

coils

14 and 126 and to return the receiver 10 to the standby condition.

Element 104 is a D.C. rectifier and element 109 is a lamp connected across plug 11 to indicate whether or not there is suiiicient line voltage `to operate the receiver.

The receiver 10 illustrated in FIG. 1 is just one of the several receivers disclosed in my aforementioned copending application and it Will be apparent as the description proceeds that the present invention is not intended to be limited to the particular receiver 10 illustrated but will find many uses in various electrical devices employing resonant circuits.

FIGS. 2 and 3 illustrate in detail the resonance relay 15 with portions removed for clarity. A support member 22 is secured to the unit 10 in any desired fashion and provides the means by which a pair of resilient clamp members 23 are carried. f Screws or bolts 23A are provided to secure the clamps 23 to the support 22.

The clamp members 23 are preferably provided with a longitudinal flat portion 24 and a substantially S-shaped portion 25 extending therefrom. The resonance reed 18 is sandwiched between the at portions 24 and secured by the screws 23A, and has a free end portion 25A extending outwardly away from the clamp members 23 into an air gap preferably left between the poles 14A of the inductor coil 14. A magnet 26 is carried on the end of the reed 18 opposite the free end 25A. The clamp members 23 arsenaal have a curved portion 27 engaging the reed member 1S at a point spaced from the portion of the reed 18 held by the flat portions 24 of the clamp members 23. A bolt 28 extends through the S-shaped portion 25 of the clamp members 23 and in combination with the nut 29 provides the means by which the curved portions 27 of the clamp members 23 may be moved longitudinally along the reed member 18 to vary the natural resonant frequency thereof. When the bolt 23 is tightened, the portions 25 tend to Hatten out, moving the portions 27 toward the free end of the reed. Thus a maximum effective reed length X and a minimum effective length Y are provided between which is a sufficient variation for producing a relatively wide range of natural frequencies.

It is apparent from the foregoing description that a resonant reed relay has been described in which difficulties heretofore experienced in providing a reed having the required natural resonant frequency are largely overcome. After the reed member 18 has been installed, the bolt or screw 28 may be tightened which causes the clamping members 23 to expand outwardly in the direction of the arrows in FIG. 2. This causes the effective length of reed member i8 to be shortened and would act to increase the natural resonant frequency of the reed. The head portion of screw 28 could extend through the cover of the unit 10 and thus permit the adjustment of the reed 18 with the cover in place. This permits the construction of a unit which can be easily adjusted to respond to a new actuation signal.

The polarizing magnet 26 is installed with the poles axially aligned with the reed 18 and serves to magnetically polarize the free end of the reed f8. In operation, the positive and negative cycles of the input signal would develop a magnetic north and a magnetic south attractive force which would cause the reed to respond since it would be polarized with either a north or south polarity.

Although I have described the present invention in cornbination with a specific receiving unit, it is apparent that it may be used in many other electrical and electronic devices and other changes and modifications may be made without departing from the spirit of the invention or the scope of the appended claims.

I claim:

1. In a resonant relay (a) a support member (b) a resonant reed member (c) mounting means securing one end of said reed member to said support member,

(d) said mounting means comprising a pair of clamp members, each of said clamp members comprising a first portion and a second portion engaging said reed member,

(e) said first portions of said clamp members engaging opposite sides of said reed member and said second portions being longitudinally spaced from said first portions and engaging opposite sides of said reed members,

(f) means fixing said first portions with respect to said reed member and means selectively operable to move said second portions longitudinally with respect to said reed member and Said first portions whereby to vary the natural frequency of said reed member.

2. In a resonant relay (a) a support member (b) a resonant reed member (c) mounting means securing one end of said reed member to said support member,

(d) said mounting means comprising a clamping means embracing said reed member,

(e) said clamping means comprising an end portion engaging opposite sides of said reed member and means fixing said end portion with respect to said reed member,

(f) said clamping means further comprising a second portion longitudinally spaced from said end portion iand engaging opposite sides of said reed member, and means selectively operable to move said second portion longitudinally with respect to said reed member whereby to vary the natural frequency of said reed member.

3. In a resonant relay (a) a support member (b) a resonant reed member (c) mounting means securing one end of said reed member to said support member,

(d) said mounting means comprising a pair of resilient clamp members carried on said support member,

(e) each of said clamp members comprising a straight portion, a medial curved portion and an end portion,

(f) said straight portions being fixed to opposite sides of said reed member, said curved portions being outwardly spaced from said reed member and said end portions engaging opposite sides of said reed members, and

(g) means selectively operable to urge said curved portions one toward the other and toward a flattened position whereby said end portions are displaced longitudinally with respect to said reed member to vary the resonance frequency thereof.

4. The relay as defined in claim 3 and in which said last mentioned means comprises a screw member passing through said curved portions and said reed member and threaded means receiving said screw member.

5. In a resonant relay (a) a support member (b) a resonant reed member (c) mounting means securing one end of said reed member to said support member,

(d) said mounting means comprising a pair of resilient clamp members and means securing said clamp members to said reed member and said support member,

(e) each of said clamp members comprising a straight portion, a medial curved portion connected with said straight portion and an end portion longitudinally spaced from said straight portion by said curved portion,

() said straight portions engaging opposite sides of said reed member and said securing means comprising at least one screw member passing through said straight portions, said reed member and said support member whereby axial movement of said straight portions with respect to said reed member is prevented,

(g) said curved portions being spaced from said reed member and said end portions engaging opposite sides of said reed member, and

(lz) means selectively operable to urge said curved portions one toward the other whereby said end portions are moved axially away from said straight portions to vary the resonance frequency of said reed member.

6. The resonance relay as defined in claim 5 and in which said last mentioned means comprises a screw member passing through said curved portions and said reed member and threaded means receiving said screw member.

References Cited by the Examiner UNITED STATES PATENTS 853,001 5/07 Bryant 200-90 2,953,726 9/ 60 Wunderlich 317-147 FOREIGN PATENTS 681,703 9/ 39 Germany.

JOHN F. BURNS, Primary Examiner.

WALTER L. CARLSON, Examiner.

Claims

1. IN A RESONANT RELAY (A) A SUPPORT MEMBER (B) A RESONANT REED MEMBER (C) MOUNTING MEANS SECURING ONE END OF SAID REED MEMBER TO SAID SUPPORT MEMBER, (D) SAID MOUNTING MEANS COMPRISING A PAIR OF CLAMP MEMBERS, EACH OF SAID CLAMP MEMBERS COMPRISING A FIRST PORTION AND A SECOND PORTION ENGAGING SAID REED MEMBER, (E) SAID FIRST PORTIONS OF SAID CLAMP MEMBERS ENGAGING OPPOSTE SIDES OF SAID REED MEMBER AND SAID SECOND PORTIONS BEING LONGITUDINALLY SPACED FROM SAID FIRST PORTIONS AND ENGAGING OPPOSITE SIDES OF SAID REED MEMBERS, (F) MEANS FIXING SAID FIRST PORTIONS WITH RESPECT TO SAID REED MEMBER AND MEANS SELECTIVELY OPERABLE TO MOVE SAID SECOND PORTIONS LONGITUDINALLY WITH RESPECT TO SAID REED MEMBER AND SAID FIRST PORTIONS WHEREBY TO VARY THE NATURAL FREQUENCY OF SAID REED MEMBER.