US2908373A - Typewriters - Google Patents

Description

Oct. 13, 1959 E. ASCOLI 2,908,373

TYPEWRITERS Filed July 14, 1958 a 2"- 7 H H Y I 12 S a E INVENTOR ENZO ASCOL) ATTORNEY United States Patent TYPEWRITERS .Enzo Ascoli, verd0n, :Switzerland, assignor to Paillard S.A., Sainte-Croix, Vaud, Switzerland, a corporation .-of Switzerland Application July-14, 1958, Serial No. 748,496 Claims priority, applicationSwitzerland August 26, 1957 'S-Ciaims. (Cl. 197-139 ""This invention relates to a pageend indicator for ofiice machines, more particularly typewriters.

'Machin'es utilizing electric page end indicators are generallyknown and may be-divided into two groups; (a) :those'using current supplied by electric battery cells .and4(-b) thosewusingthe current from an outlet of a commercial sourceof supply. The first group has the disadvantages .of' the ready exhaustibility of the energy of the .cells .and the necessity of frequently replacing them. Machinesof the .second'group may also be divided into .two sub-groups; namely, those of .the type in which the electric signalpersi'sts during the typingof the last line, and those in whichthe electric signal is only momentary. The first type necessitates contact means which are en- .:gaged during :the entire sliding movement of the carriage :and have {the disadvantages that; when particles of foreign matter lodgebetween the sliding surfaces, the current to the indicator lamp is interrupted and caused to flicker;

andzalso, .that due to wear of the sliding contacting surhaving a shaft and whichis responsive'to movement of v the carriage .inan .escapement direction, said drum connected with the carriage by a conductive metal band which is a part of the electrical circuit of the apparatus, while the shaft or spindle has a line engagement with a blade in the remainder of the circuit.

A further object of the invention is to provide a page end indicator utilizing a commercial source of current to energize the signal lamp, and, wherein, the construction is such that both sections of the carriage may be readily removed or detached from the frame of the machine by simply releasing the fastenings connecting the fixed part of the carriage with the frame. In other words, since the drum is mounted on the fixed part of the carriage, the removal of the two-part carriage makes it possible also to lift the shaft out of engagement with a single resilient wiper type blade which is connected to a transformer feeding oif a commercial line.

In the accompanying drawing is shown diagrammatically and by way of example, one form of construction of the subject of the invention. The typewriter shown in the drawing comprises, in the known manner, a framework 1, a carriage constituted by a stationary part 2 detachably connected to said framework by fastenings 2a and a movable part 3, said latter carrying a platen 4. A drum 5 turning about a spindle 6 carried by a bearing bracket 7 applies a traction on the movable part 3 of the carriage through the medium of a metal band for moving said carriage in an escapement direction. One end of said band is secured, by means of a terminal rivet 9, to a plug 10 secured to the carriage 3. The plug 10 is of insulating material, so that the band 8'is insulated .electrically from the carriage. The other end of the band 8is attached to the drum 5. As will be seen, the bracket 7 'is' secured to the stationary part 2 of the carriage throughrthe medium of stays .11 and 12 of insulating ma- 1 4, is secured to the movable carriage 3, through the medium of insulating cross-pieces 15 and 16, and cooperates with the ring 13. Said blade 14 is connected,

through the medium of a conductor 17, to the band 8.

Another -flat spring contact blade 18, secured to the framework 1 through the medium of insulating stays 19 and 20, has a wiping engagement With the shaft or spindle 6. Said blade 18 is connected through the medium of 'an-indicating device constituted by a signal lamp 21, to one of the ends ofa secondary winding 22b of a transformer 22, the other end of the secondary winding 22b is connected to the framework 1. The primary winding 22:! of the transformer 22 is connected to the electric supply network.

The machine above-described with its indicator device for the end of the page, functions in the following manner:

Before'the introduction of a sheet of paper (the case shown in the-drawing), the blade 14 is in contact with secondary winding'22b. The signallamp 21 is therefore illuminated.

The introduction ,of a sheet of paper into the typewriter, in such a manner that it passes between the ring1 3 .andrthe'leaf-springcontact 14, has as a consequence the rupture-of the ele'ctriccircuit, so that the l-amp21 isextinguished. It remains extinguished whilst the sheet separates the blade 14 from the ring 13 and re-lights when the lower edge of the sheet has passed under the blade 14, whereby the electric circuit is closed. The blade 14 is placed in such a manner that the re-establishment of the circuit takes place when the last line is to be typed.

As will be seen from the foregoing, the indicator device of the typewriter according to the invention permits'of obtaining an electric signal indicating the end of the page, said signal persisting during the typing of the last line (and the following ones if it is desired to continue) Without it being necessary for a contact to slide along the entire length of the carriage.

The existence of the elastic contact 18 co-operating with the spindle 6 of the drum 5 allows of an easy changing of the carriage.

I claim:

1. A page end indicator for the platen of a typewriter having a frame, comprising, in combination, a carriage including a movable part and a part detachably fixed relative to the typewriter frame, a platen rotatably mounted on the movable part of the carriage, a ring contact on the platen, a leaf spring contact insulatingly mounted on the movable part of the carriage and normally biased for engagement with said ring contact and disengageable therefrom by application of a sheet of paper on the platen to separate said contacts, a conductive terminal insulatingly mounted on and secured to the end of a 3 7 the movable part of the carriage opposite the leaf spring, a conductive metal band connected at one end to said terminal, a rotatable conductive drum about whose periphery the other end of the band is wound when the movable part of the carriage moves in the direction of escapement, a shaft on said drum and an electrical circuit including a signal lamp and a conductor making tangent contact with said shaft.

2. A page end indicator for the platen of a typewriter having a frame, comprising, in combination, a carriage including a movable part and a part fixed relative to the typewriter frame, a platen rotatably mounted on the movable part of the carriage, a ring contact on the platen, a

leaf spring contact insulatingly mounted on the movable part of the carriage and normally biased for engagement with said ring contact and disengageable therefrom by application of a sheet of paper on the platen to separate said contacts, a conductive terminal insulatingly mounted on and secured to the end of the movable part of the carriage, a conductor between said leaf spring contact on the movable'part of the carriage and said terminal, a conductive drum and shaft, a flexible conductive element connecting said terminal and the'periphery of said drum to move the carriage in an escapement direction, a conductive bearing bracket for said shaft, insulating means connecting the bracket with the part of the carriage fixed to the typewriter frame, and a conductor insulated from and carried by the frame of the typewriter and in tangential engagement with the drum shaft, said blade being part of a circuit communicating with a source of electrical energy and including a signal lamp adapted to glow when the said ring contact and leaf spring contact are engaged.

3. A page end indicator for sheets applied to a platen rotatably supported on the part of a carriage responsive to movement in an escapement direction in relation to the fixed part of the carriage detachably mounted on the frame of the machine, a contact ring on the platen, a leaf spring on the movable part of the carriage andrnormally biased to engage the ring except when a sheet is interposed between it and the leaf spring, a conductive terminal mounted in insulation on said movable part of the carriage and conductively connected to the said leaf spring,

- a conductive drum and shaft having an insulated mount- -'-ing on the fixed part of the carriage, a metal band connected at one end to said conductive terminal and its other end coiled about the periphery of said drum as the.

i carriage moves in said escapement direction, a spring contact blade having one end mounted on an insulating 'support on the frame and its other end making a line contact with said shaft, whereby, the entire carriage can be detached from and replaced on the frame, a transformer within the frame having its primary winding adapted for connection with a source of commercial electrical energy and its secondary winding in circuit with said contact blade and the frame of the machine, and a signal lamp in the secondary winding circuit. A

4. A page end indicator according to claim 3, wherein, the conductive terminal is mounted in the shank of an insulating plug having a head exposed at one end of the movable part of the carriage. i

5. A page end indicator for the platen of a typewriter having a frame, comprising, in combination, a carriage including a movable part and a part fixed relative to the typewriter frame, a platen rotatably mounted on the movable part of the carriage, a ring contact on the platen, a leaf spring contact insulatingly mounted on the movable part of the carriage and normally biased for engagement with said ring contact and disengageable therefrom by application of a sheet of paper on the platen to separate said contacts, a conductive terminal insulatingly mounted on and secured to the end of the movable part of the carriage opposite the leaf spring contact, a conductor between said leaf spring contact and said terminal, a conductive drum and shaft, a metal band connected to said terminal and to the periphery of said drum for shifting said movable part of the carriage in an escapement direc- 'tion, a conductive bearing bracket for said shaft, insulating means connecting the bracket with the part of the carriage fixed to the typewriter frame, and a leaf spring blade having an insulating mounting on the frame of the typewriter and in engagement with the drum shaft, said blade being included in a transformer circuit communicating with a source of electrical energy and-including a signal lamp in one leg of the circuit and adapted to glow when the said ring contact on the platen and its related leaf spring contact are engaged because of the lack of separation by said sheet of paper.

References Cited in the file of this patent UNITED STATES PATENTS

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