US544821A

US544821A - Arm-rest

Info

Publication number: US544821A
Authority: US
Publication date: 1895-08-20
Anticipated expiration: 1912-08-20

Description

(No Model.)

J. W. MORRISON. V ARM REST. No. 544,821.

Patented Aug. 20, 1895.

UNITED STATES PATENT OFFICE.

JACOB WORLEY MORRISON, OF ADAIRVILLE,-KENTUCKY.

ARM-REST.

QPECIFIGATION forming part of Letters Patent No. 544,821, dated August 20, 1895.

Application filed April 20, 1895. Serial No. 546,516. No model.)

To a whom it may concern:

Be it known that I, JACOB WORLEY MOR- RISON, a citizen of the United States, residing at Adairville, in the county of Logan and State of Kentucky, have invented a new and useful Arm'Rest, of which the following is a specification.

The present invention relates to that class of arm-rests which embody in their construction upper and lower boards or plates, interposed supports having pivotal or hinged con nections at their ends with the respective boards or plates, and a brace whereby the upper plate or board is held at the required elevation. In this class of devices as heretofore constructed the hinged or pivotal supports coming between the upper and lower boards prevent thelatter'folding into a compact form, thereby restricting the use thereof to comparatively thick books or high places. Moreover, the boards or plates, being of like width, preclude a close joint being obtained between the top board and the leaf or page to be written upon.

The object of the present invention is to provide a structure which will admit of the top or purchase board folding close upon the base or lower board, and which will enable the edge of the purchase-board to come close against and touch the end of the leaf or page to be written upon, thereby providing an unbroken surface between the said leaf or page and the arm -rest, which is of vital consequence to a penman.

A further purpose of the invention is to provide a structure which will be light, efficient,

and capable of withstanding a superimposed pressure without giving way, and which will be limited in its vertical adjustment, all of which will be more fully set forth hereinafter, claimed, and illustrated in the accompanying drawings, in which-' Figure 1 is a perspective view of the improved arm-rest Fig. 2 is an inverted perspective view showing the device folded. Fig. 3 is a side elevation showing the purchase-plate elevated to its highest position. The numeral 1 represents the base, which may have any required width and length according to the size of the required device, and

is preferably ashort length of comparatively thin wood of oblong form. The purchaseplate 2 is of similar construction to the base 1, and is connected therewith by four links 3, which have pivotal connection at their ends with the edges of the base and the purchaseplate 2, so thatin the folding of the plate 2 upon the base 1 the links 3 will not interfere with said parts coming closely together and the purchase-plate 2 resting directly upon the base 1. The purchase-plate 2 has its inner edge projected, as shown at 4, to extend over the binding of a book and come close against the end of theleaf or page tobe written upon, thereby providing an unbroken surface between the said page and purchase-plate for the fingers to glide upon in free-hand writing. The end portions of the extended part 4 are out away, as shown at 5, to provide clearance for the upper ends of the inner links 3, and in order to admit of the close folding of the purchase-plate upon the base a longitudinal groove 6 is formed in the inner side of the plate 2 on a line connecting the inner walls of the cut-away'parts 5, and this groove 6 decreases in depth from the outer to the in nor end to receive the edge portion of the link 3, which enters therein when the arm-rest is folded. The left-hand end of the purchase-plate is notched in its under side at 7 to receive and provide a finger-catch whereby the plate 2 can be elevated when it is required to raise the same from a folded position.

A rack-bar 8 is secured to the outer edge of the base 1, and its rear end is brought in close link to engage with a straight portion 9 thereof and limit the vertical movement of the plate 2 and prevent the links from passing beyond the perpendicular. A brace 10 is pivoted at its upper end to the edge of the purchase-plate 2, and has its lower edge curved and provided with a series of teeth 11, which are adapted to engage with the teeth of the rack-bar 8 and support the purchase-plate 2 in the adjusted position. By having the teeth 11 formed'on a curved line three or more can engage with a corresponding number of teeth of the rackbar, thereby preventing the cutting out and giving way of the teeth, which would occur if only one tooth of the brace 10 engaged a single tooth of the rack-bar 8. It must be readvisability of having as broad and extended engagingrsurfaces between the

parts

8 and 10 as possible to the life and usefulness of the device. In order to facilitate the operation of the brace 10, the latter is provided at its lower end with a lateral extension 12 to be grasped when moving the brace along the rack-bar 8.

From the foregoing it will be seen that the device is both simple and compact and can be economically constructed, and that the parts are disposed with the object of obtaining the best possible results.

The material from which the device is constructed is not essential to the spirit of the invention, and it will be understood that in providing the invention to meet the various needs, changes in the form, proportion, and

'the minor details of construction may be re sorted to without departing from the principle or sacrificing any of the advantages of this invention.

Having thus described the invention, what is claimed as new is 1. An arm rest comprising a base and a purchase plate of similar construction, the purchase plate having its inner edge portion extended to project over the binding of a book and touch the end of the-page to be written upon, whereby an unbroken surface is obtained between the said page and the purchase plate, the said extended edge portion having its ends cutaway and the purchase plate having a longitudinal groove on its under side corresponding in position with aline joining the said cutaway portions on their inner walls, links having pivotal connection at their ends with the edges of the base and purchase plate, one of the links adapted to have its edge portion enter the said longitudinal groove, and means for supporting the pur chase plate in the elevated position, substantially as set forth.

2. The herein-specified arm rest, comprising a base, a similarly-constructed purchase plate having its inner edge portion extended to come close against the end of the sheet to be written upon,and having its end portions cut away, said purchase plate having a longitudinal groove on its under side formed on a line corresponding with the prolongation of the inner walls of the said cut-away end portions of the extended part of the purchase plate, links having pivotal connection at their endswi-th the edges of the base and the purchase plate, one of the links adapted to have an edge portion enter the said longitudinal groove, a rack bar fastened to the edge of the base and having one end in proximate relation to a link to engage therewith and lily the vertical movement of the purchase plate and prevent the links from passing beyond the perpendicular, and a brace pivoted at its upper end to the edge of the purchase plate and having its lower end formed with a series of teeth extending on a curved line, whereby a number of the said teeth will engage with a corresponding number of teeth on the rack bar at all positions of the brace to provide a firm support for the purchase plate, and the latter having a notch at one end to form a finger catch, substantially as described for the purpose specified. v

In testimony that I claim the foregoing as my own I have hereto aflixed my signature in the presence of two witnesses.

JACOB WORLEY MORRISON. \Vitnesses:

O. P. N EAL, T. R. NEAL.