US1531138A - Universal contact bar for electric circuits - Google Patents

Description

March 24, 1925. 1,531,138

F. sATTr-:RSTROM UNIVERSAL CONTACT BAR Foa ELECTRIC CIRCUITS Filed OCC. 29 1920 MF1 A v 56 56 :o .if

.Patented Mar. 24, 1925.

UNITED STATES FERDINAND sATTnnsrnoM, or IIAsTINes,

PATENT vOFFICE.

MINNESOTA, AssIeNon 'ro MAGNETIC POWER TRANSMITTER COMPANY, 0F FABIBAULT, MINNESOTA, A CORPORATION OF MINNESOTA.

uNIvnnsAI. coN'rAcr BAB. ron-ELECTRIC crnccms.

\ Application led October 29, 1920. Serial N0.420,484.

tain new and useful Improvements in Universal Contact Bars for Electric Circuits, of which the following is a specification.

This invention relates to improvements in contact means desi ed particularly for use in connection wit a series of electric circuits such as are providedwith electrically actuated typewriters, though capable of being used wherever a plurality of electrically controlled devices are arranged to be actuated from a single battery' orsource.

of electric power or energy.

The present application is in part generic to and in part a continuation of my Patent No. 1,395,599, issued November 1, 1921, for electrical actuating means for ltypewriter type bars and other devices.

It 4is well understood that when an electric current is broken a- Spark occurs which corrodes, burns or otherwise ruins'any contact excepting one made of platinum, thereby making such contact unreliable. Platinum has been found to be the only metal which will withstand, for a' long period of time, the eect produced by the breaking of an electric current.

In devices where many make and break contacts are to be used, as in a typewriter, the number of contacts varying from pos@ sibly 40 to 80, as may be theA case, the work and expense of supplying a separate pair of platinum. contact points for each key is necessarily expensive.

One of the objects of this invention is to make use of. only a single pair of ContactA points for operating levers, such as type keys, whatever their number ma be, acting with a universal contact formlng bar located in proper relation tothe other elements of the device.

The invention consists generally in a universal contact bar or connector arranged in operative relation to a contact point or pair of contact points, and a series of operating keys or levers, whereby an electric circuit may be closed through said pair of contactpoints upon the operation of any one of sald lkeys or levers.

' In the accompan in drawn formin part of this speciictii, gs g Flgure 1 is a plan view of a portion of a typewriter key-board, with my invention applied thereto.

Figure 2 is a vertical section of the key-V board showing one arrangement of the universal contact bar or-connectorand showing also the connection of the circuits to 'the magnets of an electrically actuated typewriter.

Figure 3 isa detail illustrating the operation -of the universal contact bar, or connector.

In the drawings, 2 represents a portion of the frame of a typewriter machine, whichv furnishes support for a series of type bars 3, each of which is provided with a suitable typ'e 4. The frame 2 is preferably provided with a plate 5 supporting lugs 6 tov which the type-bars 3 are pivoted. The type-bars are arranged to be operated by actuating levers 8, each pivoted to a bracket 9 on the frame of the machine and connected to the type-bar'by a link 10. A connecting member'12 is pivoted to each of the actuating levers 8 and the position of these members is controlled by the armature 21 of the selecting magnet 20. An actuating orjpower magnet 30 is provided with an armature`29`arranged to actuate a universal power bar 24.

These parts are arranged substantially as set forth in my said pending application whereby, when t e magnets are energized, the type-bars will be actuated to impress the type upon paper suitably placed in the machine, substantially las described in my said pending applicatiom I rovide a se ecting magnet 20 for each of t e type-bars and a key-board is employed having a key, or a key-lever 40, for eac selecting magnet. A Suitable arrangement of key-board with the key-levers 40, each provided with a suitable key-top 41, is illustrated'in Figures 1 and 2 of the drawings. As here s vi ed with a suitable frame 38 upon w ich the key-levers are pivoted by suitable pivotal supports 39.A kThese keys are arranged in any preferred manner.

Arranged beneath the key-levers, and extending transversely thereof is a rock shaft own the key-board is ro-v springs 46 are connected to said crank arms and to stationary points on the machine 42 mounted in suitable bearings 43, 43. Secured to this rock shaft' preferably near its end are crank arms 44 supporting or formed integrally with the universal contact bar or connector 45. The crank arms preferably extend to the rear of the rock shaft 42 and frame. Suitable stops 44 are preferably provided to limit the upward movement of the bar 45.v The springs 46 tend, at all times, to hold the universal contact bar at the upper limit of its movement, while permitting said bar to be moved downward when pressure is applied thereto at any point in itslength. V

Arranged beneath each of the key-levers is a contact arm or member 50 preferably pivoted to a suitable insulated stationary` support 51 on the frame of the key-board and arranged to, be held in an elevated 'position by a suitable spring 52. An insulating block 53 is preferably secured to the under side of each key-lever 40, and the contact arms 50 are normally held with their upper or forward ends resting against the under side of said insulating block.

Beneath the contact bar 45 is arranged a contact spring or member 54 having preferably `a platinum contact point 54 The spring 54'is secured upon a suitable insulating support and is preferably electrically connected to a circuit wire extending to the powerniagnet 30, said power magnet having ground connections at B.

A suitable plate of insulating material 55 is preferably arranged upon the frame of the key-board. On this plate the supports 51 for the .contact arms l50, the bearings 43 for vthe rock shaft 42, supporting the universal contact bar 45, and the contact spring or member 54, are al1 supported.

Each of the contact arms 50 is in electrical connection, through a circuit wire C, with the corresponding selecting magnet 20, and each selecting magnet has a ground connection C. Supported upon theiinsulating plate 55 beneath the contact spring or member 54 is a second contact` spring or member 56 also provided with a platinum contact point 56 adapted to make contact with the platinum 54 on the spring 54, when said last named spring is depressed by the universal contact bar.

The spring 56 is connected to an electric circuit wire D which is grounded at D', and

is connected to a suitable battery E.

It will be seen that'with this arrangement 'of the universal contact bar or connector and the co-o erating elements provided in the key-boar any number of circuits may be closed with a single pair of contact springs, and, therefore, it is ,only necessary to provide -a single pair .of contact points for any number of circuits. I

prefer this construction, but these air gaps A are not necessary to the operation of the device. The upper surface of the bar 45 may be normally in contact with the under surface of all of the contact arms 50, and its under surface normally'in contact with the spring .54. In this case the only air gap is between 'the contact points 54 and 56. When any one of the key-levers is depressed the corresponding arm 50 forces the bar 45 downward forming an air gap between the bar 45 and all of the other arms 50, and pressing the two contact points 54 and 56 of the springs 54 and 56 into electrical contact with each other.

The operation of the entire mechanism vwill be more fully seen by reference to my.

closing arms, and means for bringing any one of said arms into contact with said bar or connector to move the sameinto engagement with said contact spring for the purpose of vclosing lan electric circuit,

[through the selected and operated arm.

2. A universal contact bar or connector,

vin 'combination with a circuit closing mem-l ber, and a series of operating arms, each arranged to engage said bar, and move the same into position to close an electric circuit through said 'contact member and the operated arm.

3. A universal contact bar or connector in combination with a circuit closing member, and a series of operating arms or members by which said universal bar may be moved to engage said contact member and close a circuit through said contact members, the universal bar and the operated arm. y

4. The combination, with a plurality of electric circuits, and a source of electrical energy for all of said circuits, of a universal electric connector and a plurality of bars each movable into contact-with the connector tric energy.

5. The combination, with a plurality of'130 electric circuits, and a source of electrical energy common to all of said circuits, and provided with a single contact device, of a universal circuit connectorV means movable to be first connected to said connector, and

thereafter by further movement to be brought into electrical connection with said contact devices.`

6. The combination, with a plurality of electric circuit conductors, a source of electric energy, and a contact device connected therewith, of a `universal contact bar, means for first establishing an electric :contact between any selected circuit conductor, and said contact bar, and thereafter establishing an electrical contact between said bar and said contact device.

7. The combination, with a plurality of electric circuit conductors, a battery, an electric contact device connected with said battery, of a universal contact bar or connector, an actuating lever Afor each circuit conductor, having an electrical connection with said conductor, and arranged to rst engage said contact bar and thereafter to move said bar into electrical connection with said contact device. A

8. The combination, with a plurality of electric circuit conductors, a source of electric energy, and an electric contact device connecte therewith,` of a universal electric p connector, and means connected with each of said circuit conductors and arranged to engage and move said universal connector and, to establish an electric connection between said connector and said contact device, whereby a circuit may be closed through any one of said circuit conductors.

9. The combination, with a plurality of electric circuit conductors, a source of electric energy, and au electric `contact device connected therewith, of a universal electric connector, and means connected with each of said circuit conductors for establishin contact with said universalE connector and thereafter producing contact between said universal connector and said contact device. 10. The combination with a plurality of circiuit closing contactlsprings having an electric contact betweenA the springs, a movable contact bar or connector arranged to contact with one of said springs to close the contact between the springs, a' series of independent circuit closing arms, and means for bringing any one of said arms into contact with said bar, or connector to move the same into engagement with one of said sprin s to close the electric circuit through the se ected arm.

In witness whereof, I have hereunto set my hand this 15th day of October 1920.

FERDINAND SATTERSTROM.

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