US1396030A - Variable condenser - Google Patents

Description

W. DUBILIER.

VARIABLE CONDENSER.

APPLICATION HLED JULY25, 1911. RENEWED FEB. 2, 1921,

i ,396,0.30. Patented Nov. 8, 1921.

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WILLIAM DUBILIER, OF NEW YORK, N. Y.

VARIABLE CONDENSER.

Specification of Letters Patent.

Application filed July 25, 1917, Serial K0. 182,796. Renewed February 2, 1921. Serial No. 441,992.

To all 20110111. 2'!- muy concern.

Be it known that I, VILLIAM DUBILIER, of Xew York, in the county of New York. and in the State of New York. have invented a certain new and useful Improvement in Variable Condensers. and do hereby declare that the following is a full. clear. and exact description thereof.

My invention relates tocondensers. and has for an object to produce such a device which shall possess extreme flexibility of adjustment to assume any capacity between any desired limits.

Another object of my invention is to design such a condenser to permit the adjustment to be made without breaking the circuit in which the condenser is contained.

Other objects of my invention are to provide such an apparatus which shall be light in weight. require but small space. be economical to manufacture. and in which there shall be but slight possibility of changes in the capacity of the elements of the condenser with continued use. 1

Other objects of my invention will be in part obvious and in part specifically mentioned hereinafter.

In the drawings. in which I have shown an embodiment of my invention which is to be considered merely as typical of the principle thereof, 1

igure 1 is a plan view of the condenser:

Fig. 2 is a section On line AA. Fig. 1, with the central portion of the base cut away. and

Fig. 3 is a diagrammatic representation of the circuit connections of the device.

The different elements of the condenser are supported upon an insulating base 1 which may be made of bakelite. or other similar material. [*pon this base 1 are mounted a series of contacts 2. which may conveniently be mounted in a circle thereupon. as shown in Fig. 1. A series of condensers 3. 4. 5. etc.. are located adjacent the shown in Fig. 2. may be supported from said base by means of a sector 6. later to be described. Condensers 3. 4 and 5. in the simple arrangement illustrated, are of fixed capacities, having a common difi'erence in capacity, and one terminal of each of said condensers is placed in circuit Y with a contact 2 by means of connections 7.

A contact arm 8 is mounted upon a s indle 9, and may be moved to engage any esired .etual to the length denser is positioned contact by means of a suitable handle 10. One terminal 11 of the condenser is electrically connected with the spindle 9. and through said spindle with contact arm 8, by wire 12. which wire is embedded in the insulating base 1. In this way terminal 11 of the condenser may placed in circuitwith any desired fixed condenser 3, 4, 5 by adjustment of the contact arm 8.

To obtain a capacity of the device which is intermediate the capacity values of the fixed condensers t and 5, I employ a variable condenser having as a stationary element,thesector 6. On the form shown in the drawings. this sector 6 is a semi-circular member made-of aluminum or similar material. and is slotted at 13 to accommodate the movable element of the variable condenser. This movable condenser element comprises a thin semi-circular plate 14. carried by a rotatable shaft 15. which shaft is suitably journaled in the insulating base 1. The variable condenser formed by elements 6 andH isdesignedto have a maximum capacity substantially equal'to the common Patented Nov. 8, 1921. i

ditl'erence in capacity between fixed conof the variable condenser makes one complete revolution each time the spindle 9 is turned to more contact arm 8 a distance of one of thecontacts 2. ovable element 14 of the variable conon the shaft 15 so as to be entirely removed from slot 13 when contact arm 8 has just passed from one contact 2 to the adjacent portion of the next contact. From this construction it follows that. as contact arm capacity of the variable condenser will increase from zero. reaching a maximum when arm 8 is engaging the central portion of the contact. and decreasing again to zero as arm 8 passes from such central position to the remaining edge of the contact. 7

The remaining condenser terminal 18 is mounted upon sector 6, which sector is alsoventr continuous tween terminal 11 and removable plate 8 pames over a contact 2, the

14. Intermittent connection between these elements is, however, provided by means of a switch arm 21 which is mounted upon shaft 15, and which engages a semi-circular fixed contact 22. This contact 22 is separated from sector 6 by insulation 23, and is in circuit with terminal 11 through a wire 24, and wire 12. Contact 22 is semi-circular so that switch arm 21 engages this contact as longas plate 14 is entering slot 13, but leaves contact 22 as soon as plate 14 begins toemerge from said slot, thus throwing the variable condenser out of circuit after it has reached its maximum capacity.

In the use of-my invention the base 1 may be marked adjacent the contacts 2, to indicate the capacities of the fixed condensers connectedrespectively to such contacts. To adjust the condenser to any desired capacity, contact arm 8 will be moved to engage the contact 2 which is connected to the condenser which has the fixed capacity next lower than the desired capacity; as the arm 8 is moved across the contact, gears 16 and 17 will be rotated to adjust the variable condenser to a capacity equal to the difference between the desiredcapacity and the capacity of the fixed condenser which is connected to the contact 2. If it is desired to increase the capacity still further, contact arm 8 will be moved toward the adjacent fixed contact which is connected to the condenser of next higher value, after which the variable condenser can be adjusted to obtain any desired capacity between the value of the corresponding fixed condenser and that of the fixed condenser of still higher capacity.

From the above description it follows that any desired capacity between the limits of the capacities of the fixed condensers, may be obtained merely by movement of the arm 8 over the fixed contacts 2. As the variable condenser is of a small capacity relative to the range of the whole device, a fine adjustment' is also possible. Such adjustment may also be made without breaking the circuit in which the condenser is contained. since contact arm 8 is always in engagement with one or the other of the fixed contacts 2.

If a variable condenser alone is employed to furnish the desired variable capacity, it is liable to happen that, owing to the number of sectors and plates necessary to be employed, the capacity of the condenserfor a given position of the plates, does not remain constant. This is due to the fact that, during continued use. and handling or wear of the condenser, the lates and sectors shift or warp from their initial relation to each other. Furthermore, a fixed condenser, although not subject to the above disadvantage, has the disadvantage that only certain definite capacities can be obtained. In ap-' having a.

able condenser, and yet the capacity of the condenser is practically constant, since the 1112.]01 fraction of each capacity value is supplied by a fixed condenser, and a variable condenser with very few parts to get out of order is employed, and even if the plate of such condenser shifts or warps relative to the sector, only a very small error will be introduced, since only the capacity of the variable condenser is afiected, and such ca acity is relatively small in value.

The 'ypes of condensers and switches above described are not essential to the invention, and the preferable, are but illustrative.

I claim 1. In combination, a series of fixed condenser units having. a common difierence in capacity, a variable condenser having a maximum capacity substantially equal to said common difference, and means for inserting in circuit with any of said units any desired fraction of the capacity of said variable condenser, said variable condenser being of small capacity relative to the range of the ose of a variforms described, although whole condenser, and including but few rela- 2. In combination, a series of fixed con-.

denser unitshaving a common difference in capacity, a switch for selectively'throwing said units in circuit, a variable condenser having a maximum ca acity substantially equal to said common difierence, and means for inserting in said circuit any desired fraction of the capacity of said variable condenser, said variable condenser beinglof small capacity relative to the range of t e whole condenser, and including but few relatively movable parts, whereby errors due to changes in the variable condenser are minimized.

3. In combination, a series of fixed condenser unitshaving a common difference in capacity, spectively to said units, a switch member movable over said contacts to connect any desired unit in circuit, a variable condenser maximum capacity substantially equal to. said common difference, and means connected to said switch for inserting in circuit any desired fraction of the capacity of said variable condenser, as said switch moves 'over a contact, said variable condenser being a series of contacts connected reable over said contacts to connect any desired unit in circuit. a. variable condenser having an element angular-1y adjustable to a capacity equal to said common difference, and gearing connected to said rotary switch and element for inserting in circuit varying fractions of the capacity of said variable con denser, as said switch moves over a contact, said variable condenser being of small capacity relative to the range of the whole condenser, and including but few relatively movable parts. whereby errors due to changes in the variable condenser are minimized.

5. In combination, a series of fixed condenser units having a common difference in capacity, a series of contacts connected respectivelyto said units, a rotary switch movable over said contacts to connect any desired unit in circuit, a variable condenser comprising a slotted sector. a spindle carrying a sector-like plate movable in said slot, said spindle being geared to said rotary switch. said variable condenser being of small capacity relative to the range of the whole condenser, and including but few relatively movable parts. whereby errors due to changes in the variable condenser are minimized.

6. In combination, a pair of fixed condenser units of different capacities, a variable condenser, and means for throwing into circuit any one of said units and any desired fraction of the capacity of said variable condenser, while maintaining a closed circuit condition at all times, said variable condenser being of small capacity relative to the range of the whole condenser, and including but few relatively movable parts, whereby errors due to changes in the variable condenser are minimized.

7. In combination, a series of fixed condenser units having a common difference in capacity, a variable condenser having amaximum capacity substantially equal to said common difference, and means for throwing into circuit any one of said units and any desired fraction of the capacity of said variable condenser, while maintaining a closed circuit condition at all times. said variable condenser being of small capacity relative to the range of the whole condenser, and including but few relatively movable parts,

prising a plurality units having a common difference in capac capacity. a base whereby errors due to changes in the variable condenser are minimized.

8. In combination a fixed condenser comprising a plurality of separate and distinct units having a common difference in capacity, switchingmeans for selectively placing said units in circuit including contacts respectivelyconnected to said units and a contact arm selectively engageable with said contacts, a variable condenser in circuit with said fixed condenser, and a common operating means for shifting said variable condenser and said contact arm. I

9. In combination a fixed condenser comof separate and distinct ity, switching means for selectively placing said units in circuit including contacts arranged in circular fashion, a contact arm located centrally with regard to said contacts, said contact arm being selectively engageable with said units,.a variable condenser in circuit with said fixed condenser including a rotatable movable element, and a common rota-table opera-ting member for shifting said contact arm and the rotatable element of said variable condenser.

10. In combination a fixed condenser in eluding units having a common difference in plate carrying contacts respectively connected to said units, a rotary switch arm centrally disposed with respect to said contacts, a variable condenser secured to said base plate, and a rotary shaft journaled within said base plate adapted to actuate saidcontact arm and the movable element of said variable condenser.

11. In combination a fixed condenser including units having a common difference in capacity, a base plate carrying contacts respectively switch arm centrally disposed with respect to said contacts, a variable condenser secured to said base plate and interposed between the same and said fixed condenser, and a rotary shaft passing through said base late adapted to actuate said contact arm an the movable element'of said variable condenser. In testimony that I claim the foregoing I have hereunto set my hand.-

WILLIAM DUBILIER.

connected to said units, a rotary I

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