US397950A

US397950A - Vacuum-arrow

Info

Publication number: US397950A
Authority: US
Publication date: 1889-02-19
Anticipated expiration: 1906-02-19

Description

ill/670%? W4: %%mm aw iii/011$ 7? 012% hu A Patented Feb. 19'

(No Model.)

15. WHITE.

1 VACUUM ARROW.

UNTTED STATES PATENT OFFICE.

FRANK WHITE, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO PHILIP IV. PRATT, OF BOSTON, MASSACHUSETTS.

VACUUM-ARROW.

SPECIFICATION forming part of Letters Patent No. 397,950, dated February 19, 1889.

Application filed July 30, 1888. Serial No. 281,485. (No model.)

To aZZ 1117mm. it may concern:

Be it known that I, FRANK \VHITE, of Philadelphia, in the county of Philadelphia, in the State of Pennsylvania, have invented a new and useful Improvement in Vacuum-Arrows, of which the following is a specification.

This invention consists in an arrow composed of a shaft and an elastic or yielding tip or head suitably secured to the shaft and having a concave front surface, forming an elastic cup, from which the air is expelled, wholly or in part, by the forcible impact of the arrow-head against a flat smooth surface when the arrow is discharged, so that the arrow is held in contact with said surface by atmospheric pressure, as I will now proceed to describe.

Of the accompanying drawings, forming a part of this specification, Figure 1 represents a perspective view of an arrow embodying my invention. Fig. 2 represents a view of the same, partly in longitudinal section. Fig. 3 represents a perspective view of the wire shank whereby the arrow-shaft and its elastic cup-shaped head are connected.

The same letters of reference indicate the same parts in all the figures.

In the drawings, .9 represents the arrowshaft, and 72 represents the elastic head or tip thereof. Said head is composed of elastic rubber, and is of generally concavo-convex form in cross-section, its front surface being concave and its margin reduced to a thin flexible level edge, which yieldswhen the head, in the flight of the arrow, strikes a smooth flat surface, the momentum of the arrow acting to wholly or partly eject the air from the space between the concave front surface of the head 71 and the surface with which it comes in contact, so that the arrow is firmly held in contact with said surface by the pressure of the atmosphere on the rear surface of its head. The margin of the tip or cup is preferably circular.

I prefer to call the elastic tip or cup a vacuum or pneumatic arrow head, because it is caused to adhere to the surface against which it strikes by the exhaustion of the air from between its concave front and the said surface.

The vacuum arrow-head may be secured to the shaft in any suitable way. I have here shown as the securing device a wlre 3 shank, 0, having a disk, 0, formed on one end. 1 The material of the head is molded upon said disk, thus securing the shank to the head. The shank is inserted in one end of the arrow-shaft, as shown in Fig. 2, the shaft being provided with a sheet-metal ferrule, f, to prevent it from splitting where the shank is inserted. It is obvious, however, that my invention is not limited to the particular means here shown for securing the vacuum arrowhead to the shaft.

I prefer to make the arrow-shaft slightly tapering in form, its diameter decreasing from its head to its rear end, to reduce the weight of the shaft at its rear end, and thereby minimize the leverage exerted by the shaft on the vacuum arrow-head when the latter is in contact with the surface against which it is shot.

It will be found advantageous to moisten the margin of the vacuum-head before firing, the moisture preventing the admission of air between the head and the surface to which it adheres, to enable the edge of the head to conform more closely to the said surface.

The rear end of the shaft may have a notch to receive a bow-string.

I claim- 1. The combination of an arrowshaft and a vacuum (or pneumatic) arrow-head secured to one end thereof.

2. The combination of a vacuum arrowhead, an arrow-shaft, and a connecting-shank fixed in one end of the arrow-shaft and having a disk-head secured in the vacuum arrowhead, as set forth.

3. The combination of a vacuum arrowhead, an 21-110\ '-shaft, a shank connecting the same, and a ferrule surrounding the head of the arrow-shaft, as set forth.

l. An elastic arrow-head having a concave front side, a yielding level edge, and an at taching device whereby it may be secured to a shaft, as set forth.

FRANK WHITE.

'Witn esses:

EDWARD STROHMANN, THOMAS B. PARKE.