US1221829A - Adding-machine. - Google Patents

Description

R. L. BURD.

ADDING MACHINE.

APPLICATION FILED AUG.8.1913.

1,221,829. Patented Apr. 10, 1917.

. v 2 SHEETS-SHEET l.

R. L. BURD.

ADDING MACHINE.

APPLICATION HLED AUG.8, 913. 1,221. ,829. Patented Apri 191? I 2 SHEETS SHEET 2.

UNITED STATES PATENT oFFIoE;

ROY I1. BURD, OF CHICAGO, ILLINGIS, ASSIG-NOR TU BURROUGHS ADDING MACHINE COMPANY, OF DETROIT, MICHIGAN,

A CORPORATION OF MICHIGAN.

ADDING-MACHINE.

To all whom e't may concern Be it known that I, ROY L. Born), a citizen of the United States residing at Chicago, in the county of Look and State of Illinois, have invented certain new and useful Improvements in Adding-Machines, of which the following is a specification.

' This invention relates to the type of adding machines shown in prior Patents Nos. 1,016,501, and 1,023,168 issued February 6, 1912, and April 16, 1912, respectively. In these machines the turning of wheels to effect registration is done by return of spring-actuated levers after displacement thereof by depressible keys and release of the latter. The keys are arranged in rows each row made up of nine keys numbered from 1 to 9 and constructed and arranged to act upon the associated registering lever at varying distances from its pivot, the 9- key' acting nearest the pivot, the S-key' a step farther away and soon. Upon reference to said prior patents it will be observed that the acting lugs of the keys are not normally in engagement with the lever, the latter being stopped in its return movement by contact of its forward end with a than the lugs of other keys.

cross bar, and will further be observed that the lugs of the lower denomination keys 1 and 2 are spaced farther from the lever This is so because of a purpose to arrange for uniform dip or extent of depression of all of the keys while at he same time preserving a compact arrangementof the keys with their.

tops spaced. slightly and uniformly from each other from front to rear. The keys are normally upheld by comparatively light springs and been found that, owing to the relatively slight resistance to depressionof the lower denomination keys prior to their striking the lever, there may be a failure to fully depress these keys against the considerably greater resistance offered by the relatively strong spring which upholds the lever, The lost motion between the lugs of the other keys and the lever is so slight that the variation in resistance to their depression does not have to be taken into account, the extent of their depression Specification of Letters Patent.

- end against a frame cross rod a Patented Apr. 10, 1917. Serial No. 783,701.

of depression against the lighter resistance 18 of such extent as to be distinctly notice able so that there is an inclination to relax the pressure when the heavier resistance is encountered.

The purpose of the present invention is to compensate for this greater extent of movement of the lower denoinination'keys against the light resistance so that there will be no noticeable increase in resistance such 'as to lncline the operator to relax the finger pres sure. It will of course be understood that failure to fully depress the key leads 'to erroneous registration. i

In the particular form of embodiment of my invention here illustrated, I interpose resistance to the depression of the lower denomination keys which, added to the re sistance offered by the light springs normally upholding the keys, substantially equals the resistance of the lever spring.

.111 the drawings which accompany and form part of this specification, Figure 1' represents in sectional right-side elevation a machine of the type shown in the aforesaid prior patents, having embodied therein means for carrying out the present invention; Fig, 2 is a similar view showing the lowest denomination key depressed; Fig. 3 a perspective view of one of the special parts employed to carry out my invention.

The machine proper requires no detailed description on account of its being fully explained in said patents. It will therefore suflice to designate only such elements of said machine as are immediately associated with the new parts introduced for carrying out the present'invention. D designates the stems of a row of keys and F the registering lever upon which these keys act through the medium of lugs d struck out from said stems and extending over the upper edge of the lever. 'Said lever is normall" uphe d by a relatively strong spring F -w1th its front as shown in Fig. l. The relatively slight spacing from the lever of the lugs d of seven of the ke stems-counting from the right of Fig, lwi be noted and the greater spacing from said lever of the lugs 03 of the other two keys which are ones bearing the numerals 1 and 9;;

For the purpose of carrying out my present invention, I pivot upon the lever F another lever or arm l0and form the latter with two raised portions or stepped shoulr be immediately resisted -slight additional resistance offered by ders 10" and 10 for engagement with the lugs of said 1 and 2-keys respectively as illustrated in Fig. l. Said lever or arm 10 is pivoted at its rear end to the lever F as shownat 10 and at a forward point has a depending finger 10 whose lower extremity is connected by a spring 11 with a forward portion of the lever F, said spring obviously tending to lift the arm or lever 10. This action is limited by the encounter against the under edge of the lever F of the lug l0 struck out from a .portion of the lever or arm 10.adjacent the fingerlO 'Normally the shoulders 10 and 10 are close up under the lugs of the 1 and 2-keys respectively as shown in Fig. 1, the stepped relation of said two shoulders being accommodated to the slightly greater spacing of the lug of the l-key above the lever F as compared with the spacing of the lug of the 2-key above said lever.

The keys are normally upheld as usual by light spring 0! surrounding the narrowed lower portions of their offered by these springs to depression of the keys being very slight as compared with the resistance offered by the spring F which uphplds the registering lever; However, as to the 1 and Q-keys it will be obvious that, with the new parts abov e described incorporated in the machine, their depression will by the spring 11 The character and disposition of this spring 11 is such however and the'relation of the lever 10 to the lever F of such character that said lever will move downwardly upon its pivot, the spring yielding, without any accompanying movement of the lever F. Obviously, therefore, depression of the l or Z-keys the distances necessary to bring its lug (Z into engagement with the upper edge of the lever F,-what may be termed the lost motion of the key, is resisted by the spring 11. This adds appreciably to the resistance offered by the light key-spring d so that the sum total of the'resistance approximates that encountered by the key when it strikes the lever F. Consequently there is no such sudden encounter of the key with the relatively heavy resistance of the registering lever as heretofore experienced and therefore no inclination on the part of the operator to relax finger pressure and so fail to completely depress the key. Of course when the lug of the key strikes the lever F there is no further movement of the arm or lever 10 about its pivot and no further stretching of the spring 11 so thatthe further depression of the key is against the resistance offered by the spring F and tlfie t e spring d, the same as in the prior structures.

While it will be seen that the above-described structure accomplishes the desired result in an exceedingly simple and efiicient stems, the resistance manner I wish it understood that my invention is not limited to embodiment in this particular form but may be embodied in a variety of forms.

I claim: 1. In a machine of the class described the combination of a reglstering lever; a serles 0 keys with stems constructed and arranged to act upon said lever atincreasing distances from the latters pivot and with lost motion between the lever and certain of said key stems which act at the greater distances; and compensating means for motion; between said certain key stems and the lever is being taken up, whereby to create substantiallyuniform resistance to the depression of said certain key stems though displacement of the lever by them is less proportionately to the extent of their depression than is displacement of said lever by other key stems proportionate to similar extent of depression of thelatter, such other key stems'acting independently of said compensating means.

2. In a machine of the class described the combination of a registering lever; a series of keys with stems constructed and arranged to act upon said lever at increasing distances from the latters pivot and with lost motion between the lever and certain of said key stems which act at the greater distances; and compensating means for the said certain key stems only, said means ofierin resistance thereto while said lost motion etween the said certain key stems and the lever is being taken up, whereby to create substantially uniform resistance of said certain key stems though displacement of the lever by them is less proportionately to the extent of their depression than is displacement of said lever by other key stems proportionate to similar extent of depression of the latter, such other key stems acting independently of said compensating means. .i

3. In a machine of the class described, the combination of a spring-held registering lever, a series of depressible spring-upheld keys with stems constructed and arranged to act upon said lever in opposition to its spring at increasing distances from its pivot and with lost motion between the levers and certain of said key stems which act at the greater distances, and compensating springmeans applied to such key stems only and offering resistance to their depression while the lost motion between them and the lever is being taken up, whereby to create substantially uniform resistance tothe depression of said certain key stems though displacement of the lever by them is less proportionately to the extent of their depression than is displacement of said lever by other key stems proportionate to similar the said certain key stems only, said means acting while said lost to the depression extent of depression of the latter, such other key stems acting independently of said compensating means.

e. In a machine of the class described, the combination of a spring-held registering le- Ver, a series of depressible spring-upheld keys with stems constructed and arranged to act upon said lever in opposition to its spring at increasing distances from its pivot 10 and With lost motion between the lever and certain of said key stems which act at the greater distances, an arm pivoted on said lever, and a spring upholding said arm for Witnesses:

FRANK PARKER DAVIS, ROBERT DOBBERMAN.

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