US2140541A - Chair tip - Google Patents

Description

c. w. MOORE Dec; A2o, 1938.

CHAIR TIP Filed July 12, 1937 ,'"UNITED STATES siblebearing surface.

' of soft (and cheap) material elsewhere.

vPatent-ed Dec. 20,1938 l PATENT QFFICE l*2,140,541" y y 1 V(immuun Charles W. Moore, Fullerton, Application July 12, 1937, Serial No. 153,173

n 4 Claims. My inventionrelates to tips 'forthe-lower extremities of furniture legs, land. particularly to f chair leg tips. Among its principal' objects are;

Y grst, to` provide an improved article of this na- A lfthestated purposes ina simple and relatively inexpensive construction, Which may be readily applied'without special tools.

, Itis well known to those familiar with this art,

. lthat the Vresilient cushioning member should be 420. relatively thick, andbe Aafforded the greatest pos- Otherwise it is difiicult to secure either sufficient yield, or satisfactory Y life. Moreover, the vresilient member should be evenlthough the cooperating chair leg is non-vervtical by a substantial angle. lUnless the tip is adaptedV to fully seat its bottom surface upon the v35y floor, pressure will be localized and intensified atv the contact area. 'I'he result is almost certain damage to soft floors, such as those covered with linoleum for example; and, since it localizes wear on the tip, the useful life of the device tends to 40v be proportionally reduced. Still further as to objects, it is highly desirable for devices of this class to possess sound absorbing qualities in a marked degree. In large rooms yfilled with people, the noise due to moving chairs, `particularly when they are slid over marble or cement' floors, may be very objectionable.

' In my improved construction, means have been adopted forattaining all of the objects which have been indicated as being desirable. Moreover, I

(and expensive)v metal where wear occurs, and This greatly reduces manufacturing cost when comparison is based upon quality and capacity for 55 Wear.

have made it feasible to make use of very hard' My objects are attained in the manner illustrated in the accompanying drawing, in which:

Figurefl is an elevation of an approvedembodiment of my device in axial section, and indicates its functional relationship to a co-operating chair Figure2 is a plan view of the tip construction shown in Fig. l, after the resilient cushioning member has been removed; this View being partly in section taken on the plane 2-2 of Fig. 1;

Figure 3 illustrates another approved embodiment of my invention in axial section; and is similar to Fig. 1;

Figure 4 is a plan view of the tip construction shown inl Fig. 3, after the resilient cushioning member has been removed; this view being partly in section taken onthe plane 4-4 of Fig. 3;

Figure 5 represents a slightly modified form of the construction shown in Figs. 1 and 2, this form being adapted for use when the utmost possible elimination of noise is not imperative; and

Figure 6 is a fragmentary elevation of the lower yend of a steel chair leg, indicating the manner in which tips of the general form shown in Figs. 3 and 4 may be attached thereto. l

Similar reference numerals refer to similar parts, throughout the several views; l My invention, in any of the forms it may preferably assume, comprises a circular base-cup II, which may be made of hardened steel. This has a flat sole'or bottom surface at I2, and a rounded periphery at I3. This form of base has been found to be much the easiest on floors, especiallyr'ela- Vtively soft floors such as those covered with linoleum, since it provides the maximum bearing surface. 'I'he sole or bottom surface is polished to reduce friction.

Within the base cup, and attached thereto, is a domed washer-like member, as at I4 and I4' of Figs. l and 3 respectively' These members take the general form of an inverted saucer; and,

, in co-operation with the base cup, afford a chamber I5 for loosely containing and conning the heads of whatever attachment means are to be employed, such as the part I6 of Fig. 1 or I6 of Fig. 3.

In Figs. l, 2, and 5, an ordinary nail I1 is employed for attaching my device to the lower extremity of a wooden chair leg I8. In Figs. 3 and 4, a square headed lag screw I9 is shown similarly employed. Fig. 6 shows a common form of lower extremity of a steel furniture leg at 2|, and here the attaching means comprises a bolt 22 and a nut 23.

In each case, the shank of the attaching means passes through a hole 24 in the center of the domed members I4 or I4'. The diameter of this hole is much larger than that of the shank, to permit the latter and therchair leg to assume very substantial angularity with respect to the axis of the domed member. Such angularity with respect to the chair leg is shown by dotted lines 25.

The under surface of the central portion of domed members I4 and I4 is made spherical, as shown at 26 and 26. The head of the attaching means is either made circular, as indicated at I6, or a circular Washer 21 is employed Yabove the head. The entire peripheries of these cir,

cular heads or washers are adaptedto seat upon spherical surfaces 26 or 26' independently of the angular position.

Members I4 and I4', in my improved construc tion, usually are made of soft steel, and are'attached to the base cup by means of spot-welding. This may be accomplished very satisfactorily by forming these members with three equally spaced projections 28, on their under surfaces near the peripheries; corresponding depressions, above these projections, being shown von the drawing at 29. One electrode of an electric Welder may be made to engage the upper surfaces of members I4 or I4', andthe other electrodebeconnected to base cup I I. The welding current will then have to pass through the contacts at projections,

28, andthe welding will be greatly facilitated by reason of the -small area of these contacts and their relatively large contact resistances.

The cushioning member of my device comprises a circular rubber washer 3|. This has a iiat surface at the top, to seat against the lower extremity of the chair leg to which the device is attached. The loWer surface of the rubber washer is shaped to seat upon the entire upper surface of member I4 and I4 as the case may be, as well as upon rim II of the base member. Thus the duty imposed upon the rubber is spread over the largest possible area, and the life of the rubber is prolonged in consequence.

When the device is to .be screwed upon the extremity of a chair leg, as illustrated in Fig. 3; or is to be bolted thereto, as indicated in Fig. 6; the attaching means may have a square head which fits loosely'within a square recess 32 in member I 4'. In such case the fit should be close enough to prevent the head from turning in the recess, but loose enough to permit the necessary angularity of positioning that has been described above.

I prefer to make washers 21 of such material as indurated wood or asbestosbre, because of the very great sound-deadening qualities Vpossessed thereby. When this is done, although the device Will be rmly held in place at all times, there will be no metallic Vconnection whatever between the base cup and the chair leg. Sound vibrations, originating in the base cup, will be almost completely absorbed for this reason, and there will be a minimum of noise in using furniture thus equipped.

Having thus fully described my invention, I claim: Y Y

1. Adevice of the character described, comprising; a cupper base; a co-aXial washer with a Vsquare dome, within the base and aflixed thereto;

an attaching member, having a square head loosely confined Within the dome and prevented from substantial axial turning thereby, and a shankV extending through a substantially larger central hole in the domed Washer; and a coeaxial cushioning'pad seated upon the entire outer surfaceof the'domed washer; the central portion of the inner upper surface of the domed washer being spherical; and said head being adapted to engage said inner surface throughout the 'entire length of an annular area at the peripheryrof an interposed at washer which is co-axial with the head.,V

. 2. A device of the character described, comprising; a base; va domed washeraixed to the base; an attaching member, having a headV loosely confined Within, and a shank extending through a substantially larger central hole in, the domed Y washer; a co-axial cushioningr pad seated upon the entire 4outer surface of the domed washer;`

and a co-aXial circulariiat washer upon said shank just above said head; the central portion of the inner surface Vof the domed Vwasher being spherical; and said circular Washer being adapted to engage said inner surface throughout the entire length of theV periphery4 of theY circular washer.A Y l 3. A construction as defined in c1aim2, wherein the circular washer is of material adapted to greatly impede the transmission of soundvibrra-Y tions therethrough. Y

4. ,A construction as defined in claim 2, wherein the circular Washer is'of relatively incompressible material, and also adapted to greatly impede the transmission of sound vibrations therethrough.

l V.CHARLES W. MooRE.

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