TECHNICAL FIELD OF THE INVENTION

The present invention relates to novel , improved, disposable bags for cooking comestibles. More specifically, the present invention relates to bags of the foregoing character which: (1) are fabricated from a folded-in-t o sheet (or a flattened tube) of pliant sheet material, and (2) have witness or registration marks equidistantly spaced around the open upper end of the bag to facilitate the attachment of the bag to a cooking utensil accessory with which the bag is employed.

BACKGROUND OF THE INVENTION

Earlier issued Alexander P. Janssen patents Nos. : 3 ,946 ,654 dated March 30 , 1976 , and entitled COOKING UTENSILS; 4,00 ,645 dated February 1, 1977 , and entitled COOKING UTENSIL ACCESSORIES; and 4 ,215 ,629 dated August 5 , 1980 , and entitled COOKING UTENSILS are hereby incorporated in this specification by reference. Those patents disclose: (1) novel cooking utensils intended to be used with a disposable bag in which the comestibles are contained during the cooking process, and (2) novel accessories for giving conventional utensils the same capabilities as the utensils specifically designed for use with disposable bags. In cooking comestibles by the techniques described in the foregoing patents, the bag is surrounded by a cooking medium which transfers heat to the contents of the bag during the cooking cycle. The

cooking medium will typically be water in the case of εtovetop cookery and air for oven cookery.

Cooking in disposable bags as just described has a number of important advantages. First, this permits comestibles to be cooked in their own juices. The natural taste of the food is thereby preserved; and the loss of nutritional values which occurs when oods are cooked in water is avoided, along with the mushy or waterlogged texture which commonly results. Another virtue is that the utensil is not soiled during the cooking process. Thus, the inconvenience of cleaning the utensil after it is used is eliminated; only rinsing and drying are required.

-Furthermore, the bag in which the comestibles are cooked can be used to store them. This is a particular convenience if the bag is stored in a refrigerator container or the like as the latter will not become soiled.

Particularly useful embodiments of the previously disclosed Jans sen inventions have an arrangement for detachably securing the lower corners of the bag in place. This produces two important advantages.

.First, this keeps the bag from being buoyed upwardly in a liquid cooking medium and, ^" also, permits the cooking medium to more effectively collapse the bag against the comestibles. The result is that the bag is more uniformly surrounded by the cooking medium, producing more efficient and uniform cooking of the comestibles.

Second, by securing the lower end of the bag in place, corners are eliminated; and a rounded, more

open shape is given to the lower end of the bag. This significantly facilitates access to the comestibles in the bag and the removal of the comestibles from the bag. Novel, disposable, comestibles-containing bags for the cooking utensils and accessories just described are disclosed in U.S. Janεsen patents Nos.: 4,412,482 dated November 1, 1983, and entitled DISPOSABLE COOKING BAGS and 4,499,817 dated February 19, 1985, and also entitled DISPOSABLE COOKING BAGS. Those patents are also hereby incorporated in this specification by reference.

The disposable cooking bags disclosed in the foregoing patents have an open upper end; and the cooking utensil accessories with which they are used have a circular base and a set of concomitantly pivotable, bag-supporting elements that are spaced around the base and attached to the upper edge of the base. The inner ends of the pivotable elements are clipped or otherwise fixed to the upper edge of the disposable bag at intervals therearound. Those elements can consequently be pivoted: (1) upwardly and outwardly to open the upper end of the bag, and (2) downwardly and inwardly to close that end of the bag.

Thus, the upper end of the bag can be opened or spread to facilitate the loading of comestibles into the bag and the removal of cooked comestibles from the bag. And the just-described mechaniεm allows the upper end of -the disposable bag to be closed during the cooking cycle to the extent that a liquid cooking medium surrounding the bag is kept from entering the bag while gases and vapors evolved from the comestibles are allowed to escape. This permits the bag to collapse against its contents, considerably increasing the

-4- efficiency with which heat is transferred to the comestibles; it also maximizes the uniformity with which heat is transferred to the comestibles f om different directions. Furthermore, by permitting gases and vapors to escape, the tendency of the bag to float is minimized as is the possibility of the bag rupturing due to a build-up of internal pressure.

Notwithstanding the foregoing, those systems or cooking comestibles that are described in the several patents cited above have a significant disadvantage. This is that it is somewhat difficult and time consuming to attach the upper edge of the disposable cooking bag to the inner ends of the pivotable elements with an equal chord — or length of upper bag edge — between -adjacent elements. It will be appreciated by those to whom this specification is - addressed that approximately equal spacing is required because the upper end of the disposable bag cannot otherwise be ully opened. Consequently, with uneven spacing, difficulty can be experienced in loading comestibles into the bag and in removing cooked comestibles therefrom. Alternatively, the user must tinker with the connections between the bag edge and' the elements to which that edge is attached until the spacing is more-or-less equal; and that can waste an appreciable amount of time.

SϋMHARΪ OF OBE INVENTION

I have now invented, and disclosed herein, certain new and novel disposable cooking bags which: (1) are designed for use with the cooking utensil accessories disclosed in my above-cited, earlier issued

patentε, but (2) allow the inner ends of the accessory' s pivotable, bag-supporting elements to be easily and quickly attached to the open, upper edge of the bag at precisely equal intervals therearound. Thus, the user can easily insure that the bag can be fully opened after it is assembled to the accessory.

To a large extent, the novel disposable cooking bags described briefly in the preceding paragraph and in more detail hereinafter are like those disclosed in my previously issued, above-cited U. S. patents Noε. 4 ,412 ,482 and 4 ,499 ,817.

Bags as disclosed in the foregoing patents can be made by: (1) folding a sheet of pliant material along its horizontal midline to form what will become a closed, lower bag end and the sides of the bag, and then (2) sealing the sides of the bag together along each of the two edges of the bag by seams extending from the closed lower end to the open ^" upper end of the bag. These seams keep fluids from leaking through those gaps between the sides . of the bag at the edges thereof . Alternatively, a bag of the character disclosed in the above-cited '482 and '817 patents can be fabricated by sealing together the two sides Of a flattened tube of pliant material at the lower end of the tube with a seam extending transversely from edge-to-edge of the tube to form a closed, lower bag end.

-The novel disposable cooking bags disclosed herein differ from those described in my earlier issued '482 and "817 patents most significantly in that equidistantly spaced witness or registration marks equalling the number of pivotable, bag-supporting elements of the cooking utensil accessory with which the

bag is to be employed are provided at the upper edge of the bag. By simply attaching the pivotable, bag-supported elements of the accessory to the upper bag edge at the locations designated by the witness marks, the user can ensure that the chords of the upper bag edge between each pair of adjacent, bag-supporting elements will be equal and that the bag can consequently be fully- opened.

THE PRIOR ART

Disposable bags as such are not new as shown by: U.S. patents Noε.2,323,623 issued July 6, 1943, to Porter; 2,912,336 issued November 10, 1959, to Perino; 3,008,837 issued November 14, 1961, -to Kaplan; 3,027,261 issued March 27, 9162, to Samara; 3,088,255 issued May 7, 1963, to Grie ; 3,117,875 issued January 14, 1964, to Burns; 3,547,660 issued December 15, 1970, to Weisberg; 3,615,711 issued October 26, 1971, to Markuε et al.; 3,716,369 issued February 13, 1973, to Perlman; 3,750,873 issued August 7, 1973, to Roman ^" ; and 3,935,810 issued February 13, 1976, to Milano; British Patent No. 965,498 published July 29, 1964;. the Dracket Products Co., pamphlet entitled "how to Use Cooking Magic Bags" copyrighted in 1971; and the Sears recipe and instruction book entitled "Meals in Minutes". However, none of the foregoing iteraε of prior art are relevant to the patentability of the present invention; none disclose bags which are designed for use with cooking accessories having pivotable, bag-supporting elements for opening and closing the upper end of the bag, let alone bags of that character which make it easy to quickly attach the inner ends of the pivotable elements

to the upper edge of the bag at equally spaced intervals therearound.

OBJECTS OP THE INVENTION

From the foregoing, it will be apparent to the reader that one important and primary object of the present invention resides in the provision of novel, improved,- disposable cooking bags. A second, primary object of the invention iε the provision of disposable bags which are particularly suited for use with cooking utensil accessories employing the principles of those utensils and accessories disclosed in my earlier issued and above-cited patents Noε. 3 ,946 ,654; 4 ,005 ,645; and 4 ,215 ,629.

A related and also important object of the present invention iε the. provision of disposable cooking bags as characterized in the preceding object with witness marks along the upper edge thereof .which allow the inner ends of pivotable, bag-supporting elements to be easily attached to the upper edge of the bag at equal intervals therearound, thereby ensuring that the upper - end of the bag can be fully opened to facilitate the loading of comestibles into the bag and the removal of cooked comestibles theref om.

A further important and primary object of the invention iε the provision of disposable bags for cooking comestibles which are so constructed as to: (1) provide rapid and uniform cooking of the comestibles in a manner which preserves their taste, texture, and nutritional value without soiling the utensil in which

the comestibles are cooked, and (2) provide a storage container for leftover contents of the bag.

Another important and primary object of the invention reεideε in the provision of disposable bagε in accord with the preceding object which can be inexpensively manufactured.

Other important objectε and featureε and additional advantages of the invention will be apparent to the reader from the foregoing and the appended claims and as the ensuing detailed description and discuεεion of the invention proceeds in conjunction with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING

In the drawing :

FIG. 1 iε a plan view of an attachment or accessory which iε designed to be used with a disposable bag embodying the principleε of the preεent invention and in a conventional pot or pan to cook .comestibles; FIG. 2 iε a vertical section through the accessory, the cooking utensil, and the disposable bag with the latter collapsed around the comestibles being cooked to promote the transfer of heat to the comestibles and the upper end of the bag cloεed to keep the cooking medium from entering the disposable bag during the cooking cycle while allowing gases and vapors to escape therefrom;

FIG. 3 iε a partial elevation of the acceεsory, showing a toggle mechanism incorporated in the accessory to open and close the upper end of the disposable bag in one of that mechanism' ε two operative configurations;

FIG. 4 is a section through the accessory, taken substantially along line 4-4 of FIG. 3;

FIG. 5 is a fragmentary vertical section through the accessory, showing its toggle mechanism in the second of the latter'ε two operative configurations; FIG. 6 is an elevation of the acceεsory and the disposable bag with the upper end of the latter open to facilitate the loading of comestibles into the bag and the removal of cooked comestibles therefrom; FIG. 7 is a side view of the disposable cooking bag shown in FIGS. 2 and 6;. that.bag embodies the principles of the present invention;

FIG. 8 iε a partial side view of a second embodiment of disposable cooking bag constructed in accord with the principles of the present invention;

FIG. 9 iε a second, in this case partial, side view of the bag of FIG. 8 with the two εideε of the bag flattened together; and

FIGS. 10 and U are views, similar to FIG. 8, of two more disposable cooking bags in which the principles of the present invention are incorporated.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawing, FIGS. 1-3 depict an accessory 20 which iε designed to be used: (1) with a disposable, cooking bag 22 of folded sheet construction and embodying the principles of the present invention, and (2) in a conventional cooking veεεel 24 to cook comestibles in the novel manner discussed above, i. e. , in- a way which preserves the taste, texture, and nutritional value of the comestibles, all without soiling the vessel 24 in which the comestibles are cooked.

Accessory 20 iε employed to keep disposable bag 22 submersed while the comestibles are cooking, to constrict opening 26 at the upper end or edge 27 of the bag during the cooking process, and to subsequently enlarge opening 26 so that comestibles can be easily loaded into and removed from the bag.

Among the major components of bag-associated accessory 20 are a cylindrical base 28 and a set of cooperating, inwardly extending elements 30 for supporting the upper end 27 of bag 22 from base 28.

As best shown in FIG. 1, each of the bag-supporting elements 30 has a V-shaped left-hand leg 32 and a similarly shaped right-hand leg 34 connected by a necked down, integral, U-shaped portion 36 at the inner end of the element.

Bag-supporting elements 30 are pivotally fixed to the εide wall 38 of baεe 28 at the upper edge 39 thereof. The pivotable connectionε to the baεe are provided by circular end portionε 40 of legs 32 and 34. These extend through apertures 42 in the εide wall .38 of baεe 28.

The upper end or edge 27 of disposable cooking bag 22 is attached to the inner ends of bag-supporting elements 30 by spring clips 46. These clips each have a flat, leaf spring portion 48 held against the necked down, distal or inner end portion 36 of the associated pivotable element 30 by a retainer portion 50 at the outer end of the clip. The retainer portion iε bent around the legs 32 and 34 of the associated pivotable element 30 to secure the clip in place. The upper edge 27 of the disposable bag 22 iε slipped between the spring portions 48 of clips 46 and the necked down portions 36 of pivotable elements 30, permitting spring portions 48 to clamp the upper end 27 of disposable bag 22 against the distal ends 36 of the pivotable elements 30.

In bag-associated accessory or attachment 20 , the pivotable, bag-supporting members 30 bearing bag-engaging spring clips 46 are alternated with concomitantly pivotable elements 52 having truncated legs 54 and 56 connected by an integral, lateral leg 58. The pivotable elements 52 are assembled to and around accessory baεe upper edge 39 in the same manner as bag-supporting elements 30 with the left-hand leg of each element 30 or 52 lying under the right-hand leg of the element to its left and the right-hand leg overlying the left-hand leg of the element to its right. Thus, each element 30 or 52 supports and is supported by the adjacent pivotable element. As a consequence, all of the elements 30 and 52 move in unison as one of them iε rotated either upwardly and outwardly to open bag 22 or downwardly and inwardly to close the opening 26 at the upper end 27 of the bag..

-12-

The arrangement just described has the advantage of reducing the number of the more complex bag engaging elements 30 and, therefore, the cost of accesory 20. 5 In one actual embodiment of my invention, intended or use with a three-quart saucepan, there are six bag-supporting elements of the character identified by reference character 30. There are five pivotable elements of the character identified b reference

10 character 52. The place of a sixth element of the latter type is taken by the pivotable member 60 of a retainer or toggle mechanism 62.

As best shown in FIGS. 3 and 4, toggle mechanism 62 also includes a flat, vertically extending

15 εpring 64 fixed to attachment baεe 28 adjacent itε lower end or edge 65 as by rivets 66. As its upper, free end, the εpring terminates in a downwardly opening hook or loop 68.

Member 60 of toggle mechanism 62 has inwardly

20 extending, outer legs 70 and 72 fay which the member iε pivotally attached to baεe 28 in -the εame manner as the pivotable elements 30 and 52 described previously. Integral with the outer legs 70 and 72 are two inner legs 74 and 76 connected by a transverεely extending

25 leg 77 at their lower and outer endε. The inner and outer legε of member 20 are also connected to the baεe 28 of accessory 20 in the εame manner that pivotable elements 30 and 52 are.

The configuration just described produces two

30 generally V-εhaped sections 78 and 80 defined respectively by legε 70 and 74 and by legε 72 and 76, the two legε in each section being connected at their distal ends. A fastener 82 inserted through the two

V-shaped sections 78 and 80 at these ends fixeε the two sections of the member together with one εection behind the other (εee FIG. 4) . The laterally acting spring tension of the two sections and head 84 on fastener 82 keep the two toggle mechanism sections 78 and 80 of toggle member 60 in place.

As shown in FIG. 3 , the outer, left-hand leg 70 of member 60 lies under the right-hand leg 34 of the bag-supporting element 30 to itε left; and -the right-hand leg 72 of member 60 overlies the left-band leg 32 of the element 30 to its right. Accordingly, member 60 pivots concomitantly with the bag-supporting elements 30 and the asεociated pivotable elements 52. When the bag-supporting elements 30 are rotated upwardly and outwardly to spread open the upper end 27 of bag 22 , element 60 is displaced to the generally vertical position shown in FIG. 4. In this position the lower end portions of inner -legε 74 and 76 are confined between εpring 64 of the toggle mechanism and the baεe 28 of attachment 20, maintaining pivotable member 60 in the illustrated position. Because of the interconnections between member 60 and the pivotable elements 30 and 52 discussed above, bag-supporting elements 30 are locked in the open position with the open end 27 of the bag spread and opening 26 enlarged to the maximun extent (εee FIG. 6) .

When the pivotable elements 30 and 52 are displaced to the position shown in FIG. 1 to close the opening 26 at the upper end. 27 of bag 22 and to collapse the bag around comestibles 86 (see FIG. 2) , the pivotable element 60 of toggle mechanism 62 moves f om the position shown in FIG. 4 to that shown in FIG. 5. As it does so, the tranεverεely extending leg 77 of

me ber 60 moves upwardly until it bottoms in the loop or hook 68 at the upper end of spring 64; and legε 74 and 76 of the member engage the upper edge 39 of baεe 28. This precludes further downward movement of element 60, bag-supporting elements 30, and pivotable elements 52.

As discussed above, this limiting of the downward movement of bag-supporting elements 30 iε important because it permits bag 22 to collapse around the comeεtibleε 86 in a manner which inεureε uniform and efficient cooking of the comeεtibleε and keepε the cooking medium from flowing into the bag in those applications where a liquid iε employed. Also, this limiting of downward movement keeps the various acceεsory components 30, and 52 , and 60 from pivoting downwardly to the extent that the element attaching loops at their outer ends can become unhooked from attachment- baεe 28. Accordingly, it iε not neceεεary to close theεe loops after the pivotable elements are assembled to base 28. Thus, the novel toggle mechanism 62 simplifies the assembly -of the attachment with a concomitant reduction in itε coεt.

Attachment 20 also has a latch 92 of sheet metal construction. At one end latch 92 iε pivotably mounted on the transverεe leg 58 of one of the truncated pivotable elements 52 , that leg 58 extending through a loop 94 formed at the end of the latch.

Subsequent portions of the latch extend upwardly, horizontally, and downwardly to clear the inner ends of pivotable members 30. Theεe are followed by a hook portion 96 which iε engageable with the transverse leg 58 of the element 52 facing ^, that to which the latch is connected to hold the two elements 52 in

the FIGS. 1 and 2 , "bag closed " positions. As these two elements are interconnected with the remaining pivotable elements 30 and 52 in the manner described previously, the bag-supporting elements 30 are likewise held in the illustrated "bag-closed" orientations.

As its free end, the latch terminates in a handle portion 98 by which the latch can be released and engaged.

Provision iε alεo made . in acceεsory 20 for stretching the lower end 100 of the diεpoεable cooking bag 22 acroεs the lower end 65 of the attachment base 28 and then securing the lower corners 102 and 104 of the bag to baεe 28 to keep it taut. As discussed previously, this eliminates the cornerε, facilitating the removal of comeεtibleε 86 frcm bag 22. Alεo, the lower end of the bag and itε contentε are kept from floating upwardly, promoting rapid and uniform cooking of the comestibles.

More specifically, bag 22 iε secured to the baεe 28 of attachment 20 by stretching itε cloεed end 100 acroεs the lower edge 65 of the base and then hooking the lower corners 102 and 104 of the bag over outwardly projecting studs 106 fixed to baεe 28 , the studs extending through holes 108 in the bag adjacent cornerε 102 and 104. Two diametrically opposed studs 106 are employed, one for each of the two corners 102 and 104 of the bag.

Studs 106 preferably have enlarged heads 110 over which bag 22 is stretched. The bag then relaxes to itε original configuration εo that the enlarged heads U0 of the studs keep the corners 102 and 104 of the bag in place..

-16-

The base 28 of attachment 20 can be made from sheet metal, for example. Legs 112 fixed to the base as by riveting support the base from the bottom wall 114 of the pan or vessel 24 with which attachment 20 iε employed. Spring arms 116, integral with legε 112, engage the vessel εide wall 118 and center accessory 20 in the vesεel. Bγ virtue of this and the supporting of the base in spaced relation to bottom wall 114 of vesεel 24, free circulation of the cooking medium 120 to promote uniform cooking of the cαnestibles 86 in bag 22 iε provided.

It iε preferred that buffers J22 of a εofter material be fixed to the upper, distal ends of εpring arms 116 to keep the εpring arms f om marring the pan. Thiε particularly important if the pan iε lined with Teflon or other eaεily damaged material.

Referring εtill to the drawing, FIG. 7 depictε, in more detail, the novel diεpoεable cooking bag 22 discussed above and constructed in accord with, and embodying, the principles of the present invention. Bag 22 iε of single fold construction as mentioned above. And, as was also pointed out previouεly, it haε a rectangular configuration with an upper edge (or open end) 27 and a closed lower end 100 provided by a horizontal fold midway between the ends of the pliant sheet of material from which the bag iε made. The holeε (or mounting apertures) 108 used in attaching the lower end 100 of the bag to the accessory 20 with which the bag iε employed are formed through the bag adjacent thiε lower end 100 and adjacent the two edges 138 and 140 of the bag. Apertures 108 are preferably surrounded with a black or other colored

ring 144 on βrβS b C s de 145 ap$ 1) of the bag to make the apertures easy to locate.

Inwardly , of these apertures, the two εideε 145 and 146 of the bag 22 which are formed when the sheet of 5 pliant material iε folded in two are sealed together at edges 138 and 140 of the bag by seals 147 and 148 which extend from top to bottom of the bag. Theεe seals prevent leeikage at the two edges 138 and 140 through the gaps that appear between the facing εideε 145 and 146 of

10 the bag when the pliant sheet material iε folded to produce the intermediate structure which iε converted into bag 22 by seals 147 and 148. Those seals thereby keep cooking fluid from leaking into bag 22 and, alεo, keep fluid contents of bag 22 from leaking out of the

15 bag.

Witness . marks 150 are printed on the upper edge 27 of bag 22 at equal intervals around the periphery of the bag. The spring clips 46 at the inner ends of the pivotable, bag—supporting elements 30 of

20 cooking acceεεory 20 are attached to the upper edge 27 of bag 22 at the locations marked by witness marks 150. Thiε insures that the chords (or lengths of bag material) 151 between each pair of adjacent clips 46 (see FIG. 6) will be equal and that the bag can

25 accordingly be fully opened to load comestibles into bag 22 and to remove cooked comestibles theref rom. FIGS. 8 , 10 , and 11 disclose diεpoεable cooking bags 154 , 156 , and 158 which may be identical to juεt-diε cussed diεpoεable cooking bag 22 except as noted

30. hereinafter. To the extent that cooking bags 22 , 154 , 156 , and 158 are alike, the components of those bags have been identified by the same reference characters.

-18-

Ref erring now to FIGS. 8 and 9 , diεpoεable cooking bag 154 differ ε from the cooking bag 22 described above primarily in that the back εide 146 of the bag iε longer than the front εide 145 and protrudeε above the other a distance d as εhown in FIG. 9 (and alεo in FIG. 8 in which dotted line 160 is the uppe edge of front bag εide 145 projected onto back εide 146 of the bag) . Thiε has two advantages.

First, it permits both the registration marks 162 on the front εide 145 of bag 22 and the registration marks 164 on itε rear εide 146 to be printed on the εame εide of the bag. Thuε, only one print head iε required (or, alternatively, the step of turning the bag over can be eliminated) , thereby simplifying, and reducing the cost of manufacturing, the diεpoεable bag.

The second advantage of the diεpoεable cooking - bag 154 illustrated in FIGS 8 and 9 iε that the εkirt 166 of width d at the upper end of itε back - εide 146 can be eaεily grasped independently of front εide 145. Thiε makeε it easy to open the bag from the configuration in which it iε εupplied — i.e. , flat with the two εideε of the bag together and perhaps held in that relationship by surface tension and/or static electricity.

FIGS. 7-9 depict disposable cooking bags 22 and 154 with printed regiεtration markε. It iε not neceεsary that these be employed. Instead, the regiεtration markε may be perf orationε 168 near the upper edge 27 of the bag (FIG. 10) or notcheε 170 in that edge of the bag (FIG. 11) .

Bagε of the character deεcribed herein may be fabricated from a variety of materialε. One that iε

suitable and available in quantity and in the requisite pliant sheet form iε Eapran 63B, a Nylon-type film available from Allied Signal.

It iε of course not necessary that diεpoεable cooking bags embodying the principles of the present invention be used with the particular acceεεory illustrated in FIGS. 1-6 and described above to gain the benefits which such bags offer. Other accessories with εuch bags can equally well be employed are disclose -in my earlier issued .patent No. 4 ,005 ,645; and εuch bags can be used to equal advantage with the cooking utenεilε disclosed in my earlier issued patents Noε. 3 ,946 ,654 and 4 ,215 ,629 and specifically designed to be used with diεpoεable cooking bagε. Also, the invention may be embodied in still other specific forms without departing from the spirit or essential char act eriεticε thereof . The present embodiments are therefore to be considered in all reεpectε aε illuεtrative and not reεtrictive, the scope of the invention being indicated by the appended . clai ε rather than by the foregoing deεcription; and all changes which come within the meaning and range of eguivalency of the claims are therefore intended to be embraced therein.