US 2532052 A
Description (OCR text may contain errors)
Nov. 28, 1950 F. BERMAN 2,532,052
STRAINER Filed OCT.. 9, 1947 INVEN TOR. Ffm/VK BEF/VHN Patented Nov. 28, 1950 STRAINER Frank Berman, Brooklyn, N. Y.
Application October 9, 1947, Serial No. 778,901
This invention relates to new and useful improvements in strainers and the like, and, more particularly, aims to provide a novel and improved type of interlock between the strainer frame, the handle frame where it extends around the strainer frame, and the marginal portion of the foraminous member, as a bowl of gauze or netting woven from metal strands or the like.
The foraminous member, below called the strainer sheet, has previously been attempted to be interlocked with the two frames aforesaid, by reception of the marginal portion of the strainer sheet into a recess extending longitudinally of the strainer frame.
The latter is ordinarily a strip of metal, rolled over at both long edges to a C-shaped cross sec tion, and so to incorporate a longitudinal channel with the mouth of the C facing inwardly when the parts are assembled.
According to previous practice, the handle frame is entered into the lower Zone o said channel, and, with the marginal portion of the strainer sheet entered into the upper Zone of said channel, the strainer frame is laterally crimped with the object of gripping the strainer sheet with sufficient tightness to anchor the same against separation from the strainer frame at any point around the periphery of the strainer. The incidentially intended coupling of the two frames has presented no problem; the diiiiculty has been to properly anchor the marginal portion of the strainer sheet in the assemblage.
In an attempt to overcome this difculty, it has even been proposed, in addition to pocketing the handle frame in the lower zone of the strainer frames channel, to extend the marginal portion of the strainer sheet rollingly into the upper zone of said channel, and thereafter curl the upper portion of the strainer frame inwardly of the strainer and then down toward the handle frame and then inwardly of the channel. Here, however, the grip between the marginal portion of the strainer sheet and the handle frame has been merely a line-contact one, and backed at the strainer frame by a curled portion thereof and hence with that portion at best merely a somewhat resiliently acting pressure source.
A feature of the present invention is that advantage has been taken of the availability of the handle frame as a most important element, and not merely a secondary one, for absolutely dependably secure anchorage of the strainer sheet. Such availability of the handle frame is particularly augmented, when, as is the usual practice, the handle frame is made of round wire stock of a diameter which is many times a multiple of the thickness of the strip stock of which the strainer frame is made.
According to the present invention, the marginal portion of the strainer sheet is rolled outwardly over the handle frame and then downwardly and then inwardly under the same; and.
the strainer frame, preferably previously channeled to the aforesaid C-shaped cross section, is coupled to the strainer sheet and the handle frame in such manner that the upper marginal portion of the strainer frame, shaped to present a special structure, is squeezed down tightly onto the strainer sheet where the latter is curved around the lateral convexity of the handle frame, and accordingly to follow the lateral rotundity of the latter.
The said special structure of the strainer frame is such that it conforms its lowermost concavity to the convexity of the marginal portion of the strainer sheet where the latter follows the top area of the lateral rotundity oi the handle frame. Thereby, a band grip rather than a mere line-contact grip is established relative to the strainer sheet.
Also, a dense and compacted mass of metal, this mass the special structure aforesaid and composed of a plurality of plies of the strainer frame, acts against the handle frame, in applying said band grip on the strainer sheet.
At the same time, the lower marginal portion of the strainer frame is tightly squeezed aroundI the handle frame, with the result that a second band gripis obtained. Said second band grip is on the part of the marginal portion of the strainer sheet which follows the lateral rotundity of the handle frame at the bottom and outer areas thereof, and not only this, but also at the inner area of the lateral rotundity of the handle frame when the marginal portion of the strainer sheet is extended to such inner area in curling said marginal portion around the handle frame.
For further comprehension of the invention, and of the objects and advantages thereof, reference will be had to the following description and accompanying drawing, and to the appended claims in which the various novel features of the invention are more particularly set forth.
In the accompanying drawing forming a material part of this disclosure:
Fig. l is a top plan view of a strainer comprising a strainer sheet, a strainer frame and a handle frames` Fig. 2 shows said strainer in side elevation.
Fig. 3 is an enlarged detail view, being a transverse section taken through the rim of the strainer, as on the line 3 3 of Fig. l, illustrating one form of interlock in accordance with the present invention.
Fig. 4 shows the interlock of Fig. 3, at an intermediate stage in completing the same.
Fig. 5 shows a modification of the new interlock.
Fig. 6 shows the interlock of Fig. 5 at an intermediate stage in completing the same.
Fig. '7 shows a further modication of the new interlock.
Fig. 8 shows an interlock pursuant to the modifications of Figs. 7 and 5.
Referring to the drawing in detail, and preliminarily to Figs. 1 and 2, the type of strainer shown, the size oi which is immaterial as is also the shaping of the central portion of the strainer sheet, and as are also the formations carried by the handle frame for projection beyond the rim portion of the strainer, is one wherein the strainer sheet il is illustrated as shaped at its central portion to provide a spherically arched bowl, the strainer frame ii has three cut outs i2, and the handle frame Sii is, made from a length of relatively heavy round wire stock having its ends meeting at i5 and having shaped therefrom a handle it and opposite the latter a pair of iingers il.
When the parts are assembled, the handle I6, at its restricted neck I8, is accommodated in one of the cut outs l2, and the iingers Il, at their restricted necks E9, are accommodated in the other two of such cut outs.
The strainer strip II is made Jfrom a sheet metal strip, ci a length to encircle the rim of the strainer, so that the two ends of said frame meet at some selected point around said rim, as at 2).
Referring to Fig. 3, the completed interlock here shown is one wherein the marginal portion oi the strainer sheet Iii is curled outwardly and down over the handle frame i Q- and then inwardly below the latter, with the strainer frame l I cornpressed tightly to have the parts postioned as here illustrated.
The strainer frame i! is C-snaped in cross section to incorporate a longitudinal channel, as is usual, but before said frame was arranged to pocket the handle frame I4 therein, said frame II was rolled, as shown in Fig. 4, to incorporate adjacent the upper limit of the frame i I not only a downwardly laterally curved portion 2! but below the latter a portion 22 curved upwardly and inwardly of said channel.
As a result, when the interlock is completed as in Fig. 3, with said portions E! and 22, now arranged as there shown, not only is the strainer sheet Hl clamped by a comparatively wide band grip between the upper part of the strainer frame II and the underlying part of the handle frame I4, but also by even a wider band grip between said frames opposite the band grip first-mentioned.
Saidv band grip inst-mentioned is as wide as the width of the bottom surface or the portion 22 as said portion iinally disposes itself as in Fig. 3 to conform to the lateral rotundity of the handle frame Iii; while the second-mentioned band grip is oi a width as great as nearly onehalf the cross sectional circumference of the handle frame I4, as graphically shown by the arc 23. /f
Also, the center oi the width of the band grip below the portion 22 of the strainer frame H is substantially diametrically opposite the center of the width of the band grip measured by the arc 23.
Moreover, the extra mass of metal of the strainer frame I I, provided at the rst-mentioned band grip by the two-ply special structure thereat made up of the portions 2I and 22 of said frame, one of said portions above the other, makes said band grip, although of less width than the other band grip, particularly stii and unyielding.
Further, the free end edge 24 of the portion 22 is forced to dig into the interstices of the strainer sheet I0.
Referring to Fig. 5, the completed interlock here shown is one wherein the marginal portion of the strainer sheet I is curled in the same way as in Fig. 3 outwardly and down over the handle frame i4 and then inwardly below the latter.
The strainer frame 25, corresponding to the strainer frame i I and also C-shaped in cross section to provide a longitudinal channel, was, before it was arranged to pocket the handle frame I5, therein, rolled, as shown in Fig. 6, to incorporate adjacent its upper limit a downwardly laterally curved portion 26, corresponding to the portion 2i, and therebelow a portion 2 extending inwardly of said channel; saidV portion 2'! differing from the portion 22, in that the latter was extended not only inwardly but also upwardly of said channel.
With the interlock completed yby compressing the parts to the nnal dispositions thereof as shown in Fig. 5, and with the portions 26 and 21 now arranged as there shown, all the advantages above pointed out in connection with Figs. 3 and 4, are present in Figs. 5 and 6. While the upper band grip in Fig. 5 is somewhat wider than the same means inFig. 3'. the lower band grip is, as a consequence, somewhat narrower; with the net result that an equally tight interlock is obtained in both the constructions of Figs. 3 and 5.
Referring to Figs. 7 and 8, the same tight engagement between the two frames is had in Fig. '7 as in Fig. 3, in both of which the strainer frame II is included, and in Fig. 8 as in Fig. 5, in both of which the strainer frame 25 is included. The main diiference between Figs. 3 and 7 is that in Fig. 7 the marginal portion of the strainer sheet I0 is extended over and down around the handle frame I4 so as to almost completely encircle the same. The main difference between Figs. 5 and 8 is that in Fig. 8, as in Fig. 7, the marginal portion of the strainer sheet substantially completely encircles or encloses the handle frame I4.
Consequently, in both Figs. 7 and 8, the lower band grip is of a width equal to considerably over one-half of the cross sectional circumference of the handle frame Ili, as graphically shown in Fig. 7 by the arc 28 and as graphically shown in Fig. 8 by the arc 29.
While I have illustrated and described the preferred embodiments of my invention, it is to be understood that I do not limit myself to the precise constructions herein disclosed and the right is reserved to all changes and modications coming within the scope of the invention as dened in the appended claim.
Having thus described my invention, what I claim as new, and desire to secure by United States Letters Patent is:
Means for securing a bowl-shaped strainer sheet in position with its top edge portions bent about a circular handle frame from the inside to the outside thereof and over the top thereof, comprising a circular strainer frame, said strainer frame being C-shaped in cross-section and engaged over the top edge portions of the strainer sheet from the outside of the handle frame, said strainer frame having its bottom edge bent to engage the handle frame beyond the peripheral edges of the strainer sheet torestrain movement of the strainer sheet relative to the handle frame in a direction tow-ard the bottom edge of the strainer frame, said strainer frame having its top edge portion bent under and inward and clamp between the adjacent faces of the strainer sheet and the strainer :frame so that the free edges of said bent under top edge portion engage 15 the interstices of the strainer sheet and secure The following references are of record in the le of this patent:
UNITED STATES PATENTS Number Name Date 1,392,383 Wills Oct. 4, 1921 1,906,603 Hungerford May 2, 1933 2,006,566 Zimmer July 2, 1935 FOREIGN PATENTS Number Country Date 477,129 Germany r of 1929