US2151638A - Recording instrument - Google Patents

Description

March 21, K EN E RECORDING INSTRUMENT Filed July 20, 1958 C :mmQ r w h n oc r e .t v m T lm .6 U H K Patented UNITED STATES 563K111 ROC PATENT OFFICE RECORDING INSTRUMENT ration of New York Application July 20, 1938, Serial No. 220,403 In Germany July 30, 1937 3 Claims.

My invention relates to recording instruments and concerns particularly improved marking arrangements for such instruments and methods for producing marking members.

It is an object of my invention to provide a marking arrangement for a recorder which overcomes friction by eliminating contact between the marking member and the moving chart.

It is a further object of my invention to provide a marking arrangement which may be utilized with a highly sensitive instrument and which produces clear, legible records.

It is also an object of my invention to provide a recording instrument combining the advantages of ink type and spark type recorders.

Other and further objects and advantages will become apparent as the description proceeds.

The invention may be understood more readily from the following detailed description when considered in connection with the accompanying drawing, and those features of the invention which are believed to be novel and patentable will be pointed out in the claims appended hereto. In the drawing Figure 1 is a schematic diagram partially in perspective representing one embodiment of my invention. Figure 2 is a view of a cross section 'of the marking receptacle of Figure 1 cut by the planet-2', and Figure 3 is a fragmentary view of a longitudinal section of the marking receptacle cut by plane 33' indicated in Figure 2, and illustrating the method of manufacturing a marking receptacle. Like reference characters are utilized throughout the drawing to designate like parts.

In Figure 1 a sensitive recording instrument is represented by its moving element I I, which may be a current carrying coil, for example, and is mounted upon a shaft 12 co-operating with bearings, not shown. The shaft l2 carries also a pointer arm l3 at the end of which is supported a marker H in the form of a receptacle for suitable marking material, such as ink. The ink receptacle I4 is in the form of a small tapered glass or a bottle having a filling mouth I5 at the upper end and an orifice H5 at the lower tapered end for depositing marking material. In the lower tapered end of the receptacle M a re-entrant wall or hollow bulb i1 is provided having an opening l8, the edge of which is adjacent and substantially within the edge IQ of the lower end of the receptacle" (see Figure 3). The wall of the inner bulb I1 'and the portion of the outer wall of the receptacle I4 adjacent the edges of the openings I8 and 19 together form a substantially annular orifice represented by numeral 16 in Figure 1. I have found the operation to be improved by having the edge of the opening [8 slightly higher than the edge IQ of the receptacle ll. The bulb I! may be secured by means of rods .20 (see Figure 2) extending to the outer wall of the receptacle H.

Means are provided in the hollow space within the re-entrant wall or bulb I1 to produce repeatedly sudden expansion of the air within the hollow space, for example, by ionization. Such means may consist of a pair of electrodes 2| and 22 projecting into the hollow space .within the bulb H. A pair of conductors 23 and 24 are provided which are connected to the electrodes 2| and 22 at one end and are carried along the arm l3 to a suitable source of current. To prevent interference with the deflection of the coil H a pair of loosely and oppositely wound helices or spirals 25 and 26 may be provided through which the wires 23 and 24 are connected to a suitable electric energizing circuit. The energizing circuit may consist of a source of current such as a comparatively high voltage battery 21 in series with which an intermittent make-and-break contactor 28 is provided. The make-and-break contactor 28 may take the form of a commutator driven by a constant speed motor 29.

The receptacle l 4 for marking material may be composed of a suitable non-corroding viscous material which is rigid at normal temperatures and may be softened at elevated temperatures for the purpose of manipulation, such as glass, for example. The receptacle H may be blown from a globule of glass which has been inflated and drawn out to a tapered point approximately in the shape shown. Thereupon, the neck 30 may be formed by softening the material and pressing inward as the receptacle is being rotated in accordance with the common practice known to glass blowers. Likewise, the filling mouth I5 may be formed in the upper end of the receptacle in the usual manner after breaking away from the glass-blowers tube. The re-entrant wall or hollow bulb ll may be formed by sealing of! the lower end of the receptacle by fusion, for example, and while the material is soft, blowing the end of the receptacle inward, for example, by slipping a suction tube over the filling mouth l5. v While the material is sufficiently soft, the electrodes 2| and 22 may be inserted in place. If the electrodes 2| and 22 seal suitably to the glass it may not be necessary to provide the rods 20 for holding the bulb H in place. The orifice i6 is formed after the wall 11 has been blown inward by cutting oil the lower end of the receptacle l4. This may be done by fusion or any other suitable process. Preferably the edges of the material are so cut as to lie along the cone 3| represented in Figure 3. This makes the edges of the opening I! of the bulb I! slightly higher than the edges 19 of the main walls of the receptacle H, but substantially concentric therewith.

The method of operation of the apparatus will be apparent from the foregoing description as the rotation of the commutator 28 will cause the application of voltage repeatedly to the electrodes 2| and 22, thereby repeatedly ionizing the air in a. hollow space within the bulb l1. Each time the air is ionized it expands suddenly causing the expansion of ink or other marking material which has collected at the orifice I6 and across the opening H3 in the bulb H and which is held there by capillary attraction and surface tension. It will be understood that the orifice I6 is carried adjacent the surface of a record chart. not shown, and the ink expelled from the orifice I6 is deposited on the record chart in fine, rapidly drying dots which may be placed very close together upon the record chart so as to form a substantially continuous record curve.

In accordance with the provisions of the patent statutes, I have described the principle of operation of my invention together with the apparatus which I now consider to represent the best embodiment thereof but I desire to have it understood that the apparatus shown is only illustrative and that the invention may be carried out by other means.

What I claim as new and desire to secure by Letters Patent oi. the United States, is:

1. A marking arrangement ior recqrgll mnents Z'I u::

oi sparkmelectrodes, said receptacle a ng ari'an fiular orifice and having a re-entrant wall forming a hollow space, the inner edge of said annular orifice being set in from the outer. edge of said annular orifice and forming an outlet opening for said hollow space, said electrodes extending into said hollow space and forming a spark gap therein.

2. A marking arrangement for recording instruments comprising a receptacle for marking material with an opening therein, a bulb within said receptacle having an opening adjacent and substantially within said receptacle opening ing such end of the receptacle, blowing it inward to form a hollow bulb within the receptacle, fastening the bulb within the receptacle and cutting ofl the material at the end of the receptacle and the bulb to form an annular orifice in the receptacle.

KURT GENSCI-IMER.

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