Extension arm

July 12, 1955

M. MANSON ET AL

EXTENSION ARM

2,712,972

Filed Feb. 3, 1954

Sheets-Sheet 1

<img file="US2712972A_D0001.tif" />

July 12, 1955

M. MANSON ET AL

EXTENSION ARM

2,712,972

<img file="US2712972A_D0002.tif" />

United States Patent Office ²-⁷¹²’⁹⁷²

Patented July 12, 1955

2,712,972

EXTENSION ARM

Morris Manson, Brooklyn, N. Y., and Frederick Hafekost, Hopatcong, N. J., assignors, by mesne assignments, to Steel Slides, Inc., New Rochelle, N. Y., a corporation of New York

Application February 3,1954, Serial No. 407,964 ¹⁰

Claims. (Cl. 311—71)

This invention relates to extension arms and more 15 particularly to such arms for furniture, such as tables, thereby to permit easy separation of portions thereof as for the insertion of extra leaves.

The invention in one aspect thereof is constituted by the combination of a pair of slide elements which 20 are associated in longitudinally shiftable and nested relationship, each slide element comprising a main channel member having a flared outer portion which is adapted for engaging in nested relation with a base portion of the channel member of the next adjacent slide 25 element, a transverse inner dimension of the flared portion being substantially equal to but slightly greater than the transverse outer dimension of said base portion whereby a satisfactory frictional contact is obtained and a suitable load bearing function is achieved thereby. The channel memoers are held in nested relationship in a novel manner through the intermediary of a pair of oppositely and outwardly extending primary flanges for.each slide element, each flange being secured longitudinally along its respective edge of the flared portion of the channel member and preferably integral therewith. Connected to each of such flanges and extending longitudinally therealong is a channel which is, by such connection, held in spaced and parallel relationship thereto. Such channel member has a mouth extending longitudinally of the slide element which opens inwardly toward the main channel member, there thus being two opposed subchannel members having longitudinally extending mouths which open toward one another. Such opposed subchannel members are constructed and arranged for receiving the primary flanges of the next adjacent element, this being made possible by virtue of the spaced relationship of each subchannel member to its respective flange. Such spaced relationship in effect forms a pair of opposite and outwardly opening (exteriorly accessible) subchannel members into each of which there is received one side of the first mentioned subchannel member. In order for the primary subchannel members to receive the opposite edges of said flanges and thereby to be held to said main channel members in nested relationship, the dimension between the edges of said oppositely directed flanges is slightly less than the dimension as measured between the bottoms of said primary subchannel members. The maximum dimension of each slide element as measured from 60 opposite outer surfaces of said first mentioned subchannel members is uniform with respect to all of the slide elements. Consequently a plurality of said elements in nested relationship can be associated with, for example, the under surface of a table, said slide _e5elements being in a vertical attitude and the outer fold of each such subchannel member, if desired, engaging the under surface of the table.

One of the objects of the present invention is to provide an. extension arm which is impervious to humidity and which will not become jammed or stick.

A further object is to provide an extension arm which is of extraordinarily low cost and which is well adapted for mass production techniques, each slide element thereof being fabricatable from a single strip of metal by a relatively simple bending operation.

A further object is to provide an extension arm which is smoothly workable.

Another object is to provide such an extension arm which is of simple and light construction but with adequate rigidity in. both horizontal and vertical planus, Another object is to provide such an extension arm which, when fully extended, has a little or negligible degree of sag.

A further object is to provide a derice of this type particularly adapted for extension tables upon which a plurality of spare table leaves can be supported without sag and with easy registry of all leaves.

A further object is to provide an extension arm with a heretofore unattainable high range of extension commensurate with heretofore unattained low cost.

A further object is to provide a device of this character which eliminates complicated anti-friction structures, such as ball bearings.

The above and further objects and novel features of the invention will more fully appear from the following detailed description when the same is read in connection with the accompanying drawings. It is to be expressly understood, however, that the drawings are for purposes of illustration only and are not intended as a definition of the limits of the invention, reference for ³⁹ this latter purpose being had primarily to the appended claims.

In the drawings:

Fig. 1 is a transverse cross sectional view of a single slide element embodying one form of the invention;

⁰ Fig. 2 is a plan view of the slide element shown in Fig. 1;

Fig. 3 is a perspective view of a pair of the nestable slide elements shown in Fig. 1 in nested relationship and associated with, for example, one of the separable ⁴⁹ halves of a table top;

Fig. .4 is a perspective view of a pair of slide elements in nested relationship with one another, said elements embodying another but non-analogous form of the invention;

Fig. 5 is a transverse cross sectional view of one of the slide elements shown in Fig. 4; and

Fig. 6 is a fragmentary transverse cross sectional view of a feature of construction which may be employed in the embodiment of Fig. 4.

Referring to the drawings, with particular reference to rigs. 1—3, inclusive, the novel extension arm comprises a plurality of duplicate, nestable, slidably engageable slide elements, each of which may be fabricated with great ease and at low cost under mass production 55 techniques from a single strip of sheet metal or other suitable sheet material.

The basic slide element of the invention is well shown in cross section in Fig. 1 and is designated by the numeral 10 and consists, in this form of the invention, in a main channel member 11 having a depth 12. The main , channel member 11 is constructed and arranged especially for nesting engagement with a correspond-, mg channel member of the next adjacent element in. the manner well illustrated in Fig. 3. However, reverting again to Fig. 1, such channel member, in order to effect such nesting relationship, is formed in two portions, namely, a base portion 13 having a selected outer transverse dimension 14; and a top or flared portion 15 having a selected transverse inner dimension 16 which preferably is slightly greater than the dimension 14, for example, the dimension 16 may be .010 inch larger. Consequently, there is insured a satisfac8,712,972 elements may be so associated with one another successively in the relationship shown in Fig. 3.

Viewed from another point of view, the walls 24 and 25, together with their interconnecting bend 27, comprise a primary subchannel member which is secured to the primary flange 20 and spaced relative thereto, the wails of said subchannel member being substantially parallel to the primary flange and the interconnection between the subchannel .member and such flange, although in fact along the fold 28 (Fig. 1), is in a sense at the point of engagement of the fold or bend 26 with the adjacent surface of the flange 20, that is, along a line designated by the point 26α. Consequently the primary flange 20 protrudes sufficiently from said connecting point or line to provide a flange which may be engaged by the channel 29 of the next adjacent slide element, it being, of course, understood that analogous but oppositely disposed structure is associated with the opposite side of the slide element.

In order to facilitate the proper nesting relationship of the several slide elements, the dimension 39 .is slightly greater than the dimension 40 (Fig. 1). By way of example, dimension 39 may be of an inch and dimension 40 %4.

By way of example only, there are set forth on Fig. 1 a typical set of dimensions for the various parts of the channel member, although it is, of course understood that the invention is not limited to these dimensions and that the latter are shown only for the purpose of giving the relative sizes and disposition of the parts.

In order to limit the motion of one slide element, such as 36, with respect to another slide element, such as 10, as viewed in Fig. 3, a pair of limit-stop ears may be employed, one of which is shown at 41, formed in the floor Ila of the channel member 11. Such limit-stop ears 41 may be struck out of the surface of floor of the channel member at opposite extremities of its length ana there can cooperate with a limit-stop ear 42 which may be punched or struck from floor 43 of the next adjacent slide element 36.

Referring again to Fig. 1, reference is.made to relative dimensions 44 and 45 which respectively are the transverse dimension between the outer lips of the primary flanges 19 and 20, and the transverse dimension between the Opposite floors or bottoms of the opposite channels 29 and 31. In order to insure a proper fit of such primary flanges 19 and 21, together with the adjacent peak walls 23 and 35, within their respective channels 29 and 31 of the next adjacent slide element, the dimension 44 is 50 slightly less than the dimension 45.

The normal attitude for the slide elements, such as 10 and 36 (Fig. 3) is substantially vertical, as shown, thereby to insure necessary rigidity, both in the vertical and horizontal planes.

The upper edges of the folds 44 and 45 are coplanar when such slide elements in the vertical attitude of Fig. 3 and thereby such top bends both are capable, if desired, of being placed extremely close to and, if desired, in frictional contact with the underside of a table top 46. Thus GO all of the slide elements, including as many more as desired over and above those shown in Fig. 3, may be nestably associated therewith and ali of their upper edges will be coplanar, thereby avoiding problems of. registering the separable halves of table 47 of which the aforemen05 tioned top 46 is one of such halves.

The combination of the several extension arms may be secured to the table, as is well shown in Fig. 3. For example, one of the slide elements, such as 10, can be secured to a wooden block 48 which is rigidly secured 70 by suitable means to the under surface of the table top 46. The means for rigidly securing the slide element 10 to such block 48 may comprise a plurality of nut and bolt interconnections, one of which is shown at 49. It is, of course, understood that the slide element 36 or some 75 other slide element nestably.secured.in a succession of tory frictional engagement between the opposed inner surfaces of the flared portion 15 with the nesting 'or interfitting outer areas of the next adjacent slide element corresponding to the base portion 13.

The flared portion 15 of the main channel member 11 has a pair of opposite upper lips 17 and 18 which comprise corners from each of which there extends an outwardly directed primary flange. Consequently there are a pair of such primary flanges designated 19 and 20 which are respectively secured along the lips 10 17 and ‘18 and which are outwardly directed with respect to the main channel member 11.

-Such primary flanges 19 and 20, together with their associated means to appear dlerebelow, comprise the means for holding the several nested slide elements in 15 nesting relationship with one another in such a way that a novel bearing association therebetween is effected.

Said primary flanges 19 and 20 are preferably but not necessarily substantially coplanar and are integral 20 with the main channel 11.

Also the slide elements are preferably but not necessarily symmetrical with respect to a central plane passing longitudinally down the middle of the channel 11. Any asymmetrical characteristic should be common to 25 all slide elements to insure proper nesting and telescopic engagement.

Viewing the slide element 10 in a horizontal attitude, that is with the primary flanges 19 and 20 substantially horizontal, it is seen that there are secured 30 to the respective outer edges 19α and 20α thereof a pair of double subchannel members 21 and 22, respectively, which are in transverse cross section respectively in the shape of a reverse S and an S, such reverse S and S conformation being substantially flat- 35 tened.

The subchannel member 22 consists of a peak wall 23, a center wall 24 and a base wall 25 all extending longitudinally of the slide element. The peak and center walls 23 and 24 are interconnected by a fold or 40 bend 26 and the center and base walls 24 and 25 are interconnected by a fold or bend 27. The outer edge of the peak wall 23 is connected preferably throughout its entire length with the outer edge of the primary flange 20 by means of the bend or fold 28. 45

Consequently, it is seen that the center and base walls 24 and 25, together with their interconnecting fold or bend 27, define a subchannel 29 and the peak and center walls 23 and 24 define a subchannel 30.

The outer margin portion of the primary flange 20, together with the peak wall 23, which is adjacent thereto, form a double thickness which-is slightly less than the width of the channel 29. The reason for this is that'the channel 29 of the slide element 10 is designed for receiving such a double thickness of the next adjacent and nesting slide element, as is well shown in Fig. 3.

The conformation of the double subchannel member 21 -is analogous to but reversed with respect to the subchannel member 22 above described in detail. Thus the subchannel member 21 is provided with a channel 31 formed between a center wall 32 and a base wall 33; and also with a subchannel34 formed between the center wall 32 and a peak wall 35.

Referring now to Fig. 3, there are shown the abovedescribed slide element 10 in telescopically engaged and nesting relation with a duplicate slide element 36. In the opposed inturned channels 29 and 31 of the slide element 10, there are respectively received flanges 37 and 38 which are analogous respectively to the flanges 20 and 19 (Fig. 1), it being understood, of course, that the peak walls analogous to 23 and 35 are also received in channels 29 and 31, respectively, thereby forming the above-mentioned double thickness.

Any desired number of such ^identical nestable slide

2,712,972

Such elements, can be analogously secured to another wooden block analogous to 48 or secured to the cooperating and extendable element of the piece of furniture in any suitable manner.

Referring to the embodiment shown in Figs. 4 and 5, an extension arm 50 is provided comprising a- plurality of slide elements, for example, 51 and 52, each of which is substantially similar to the slide element 10 above described with the exception that the main channel 11 has been omitted from each and in lieu thereof the pri- l· mary.flanges thereof (analogous to 19 and 20, Fig. 1) are associated without the aforementioned intervening channel member (11, Fig. 1).

The basic element 51 of the extension arm 50 itself thus is in the form of a channel member having a floor i: or bottom 53 with sides 54 and 55 which have been partially collapsed, preferably by bending, to the form well shown in Fig. 5, the side 55 being collapsed in such a way that its transverse cross section is in the shape of a flattened S and wall 54 of a reverse S. Each of £' the elements 54 and 55 have peak walls 56 and 57 which preferably but not necessarily are held in spaced relationship from the floor 53 of the channel member.

Thus the embodiment or Figs. 4 and 5 comprises also a series of duplicate nestable slide elements, the basic ele- 2.; ment of which comprises a channel member having sides 54 and 55 shaped to form mturned lips 58, 59 and 60, 61. The inturned lips 59, 61 are each in the form of a channel having a mouth which opens outwardly of the overall channel member, that is, the mturned lips 59 and 61 form 3: channels 62 and 62α respectively which are exteriorly accessible, viz., the mouths thereof open exteriorly of the slide element. The inturned lips 59 and 61 are disposed in the same relative positions on opposite sides of the slide element but. pointing towards one another. The same is 35 true of the inturned lips 58 and 60 which also are preferably but not necessarily coplanar.

As shown in Fig. 5, the edge 63 is closer to the axis 64 than the edge 65. The same relative disposition is true cf the edges 66, 67. The edges 63 and 66, respectively, 43 comprise the outer longitudinal edges of the oppositely disposed and outwardly protruding primary flanges which are analogous to the primary flanges 20 and 19 (Fig. 1). Such outwardly protruding flanges are received by the inwardly.directed subchannel members 68 and 69 (Fig. 4) 45 of the slide element 52.

The reason for the difference in the disposition of the edges 63 and 65 with respect to the axis 64 is to permit the next slide element to nest easily thereupon and to permit each element to be a complete duplicate of all 50 of the others.

Reverting to Fig. 3, it is seen that each slide element, such as 10, engages each next adjacent nested slide element, such as 36, along four longitudinally extendin°· areas as follows: -. . 5a (a) the outer edge of the bend or fold 53 (Fig. 3) engages the inner edge or bottom surface of the channel 31 formed by the center and base walls 34 and 33 interconnected by bend 33α;

(έ) and (c) the opposite inner surfaces of the flared 60 portion of each channel member 11 engages the outer surface of the restricted or base portion of the next adjacent channel member; and (d) along the lower edge of the channel members shown (Fig. 3) there is an engagement analogous to that between the bend 53 and the bottom or inner surface of the channel 31.

If desired, face-to-face inner longitudinally extending edges of the base walls 25 and 33 (Fig. 1) may have „ beads secured thereto which may cooperate with and '° extend into a suitable passage formed in the channels 30 and 34 of the next adjacent slide element, such passages embracing the bead substantially throughout its periphery thereby providing a locking means for aiding in with- 75 standing loads upon the extension arm when in an extended condition.

There is thus provided a novel extension arm having a desirable and important characteristic in that the top &gt; edges of such elements when nested and vertically disposed are at a common level. This is of practical importance in the application of the extension arm, for example, to extension tables which have separable halves, because one side of the table must be secured to the 3 extension arm at one level and the other side of the extension table must be secured to such extension arm at the same level. Otherwise, the primary halves of the table top could be at different levels but secured to the same extension arm, the latter being extended, and thence 5 problems of placing the spare leaves in register would arise. In addition to the above, it is necessary to present a perfectly level top surface for the support of the spare leaves or cross bars of the table and this is accomplished by virtue of the common level of the top edges of ) the various slide elements.

Although only two modifications of the invention have been illustrated and described in detail, it is to be expressly understood that the invention is not limited thereto. Various changes may be made in the design and ari rangement of the parts illustrated as will be apparent to those skilled in the art. For a definition of the limits of the invention, reference will be had primarily to the appended claims.