US71546A - sm-ith - Google Patents

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PATENTED Nov 2e 1867 W/TNESSES @einen tutrs getraut @frn 'rf s. SMITH, CE NEW HAVEN, CONNECTICUT. Letters .Patent No. 71,546, dated November 26, 136;?.

IMPROVED BALL GASTER.

TO ALL WHOM IT MAY CONCERN.:

Be it known that I, T. S. SMITH, of New Haven, in the county of New Haven, and State of Connecticut, i have invented a new Improvement in Ball Casters; and I do hereby declare the following, when taken in connection with theV accompanying drawings, and the letters of reference marked thereon, to be a full, clear, and exact description of the same, and which said-drawings constitute part of this specification, and represent, in

Figure 1, a side view Figure 2 a. central section, and in Figure 3 an under side view of the ball-seat. l This invention relates to an improvement in casters for furniture, and consists in the peculiar formation of the seat combined with the hall, whereby the driving-point is far above the centre, and near the point of bearing.

Bull casters of various forms have been constructed, but generally so great has 'heen the friction, that when attached to heavy articles the hall would not revolve, but in all such, the point of driving the ball, that is, the point which bears against the ball in the movement of the furniture, is so far below the centre and distant from the point of bearing, that thc leverage from the point of bearing to the point of driving and point of contact with the floor is so great' that the ball will not revolve.

' By my invention these diiiculties are entirely overcome, and in order to the better understanding of my l invention, as well as to enable others to construct the same, I will proceed to n description thereof. As illustrated in the accompanying drawings-- A is tue upper part or seat of the caster, formed with a recess, B,hav,ing straight sides, as seen in fig. 3. These may he three or four; I prefer four. The bottom of this recess is flat, so that the ball C will bear against thc surface of the recess with the least possible friction, and when so hearing, the sides of the recess are of such dimensions that, when bearing upon one side, the hall will'not quite touch the opposite side. Thus, when the seat A is fixed to'the furniture, and the rball C placed in the recess thereunder, the weight is supported upon the ball upon a. single point, and when` the furniture is moved, say to the left, the point a of one side of" the recess hears against the ball near the top, so that the leverage from the ordinary construction is reversed, and the longer arm of the lever being4 toward the floor, upon whichtis the greater amount of friction, and thus the ball will be driven, revolving upon the point of Contact upon the surface of the recessB. In order to prevent the ball from dropping from its seat, when the furniture is raised, I form a cup, D, which wholly or partially surrounds the ball belbw its centre, but sous not to touch the ball when the weight of the furniture rests uponv the ball. This cup is attached to` the sont in any convenient manner, so that, when the furniture is raised, the ball will drop into the cup, and be held in position-to return to its seat when the furniture is again set down. v

I Clonot broadly claim a ball caster, as such are common und well known; but What I do claim as new and useful, und desire to secure hy Letters Patent, is- The seat A, constructed with n recess, B, so as to form an angular recess, said recess forming a single bearing-point on the top, and two driving-points a near the top of the ball, ns set forth.

, VT. S. SMITH. Witnesses: I JOHN E. EAnLE,

A. J. Trnnus.

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