US2981292A

US2981292A - Weaving with double wire motion

Info

Publication number: US2981292A
Application number: US718309A
Authority: US
Inventors: Frank W E Hoeselbarth
Original assignee: CH Masland and Sons
Current assignee: CH Masland and Sons
Priority date: 1958-02-28
Filing date: 1958-02-28
Publication date: 1961-04-25
Anticipated expiration: 1978-04-25

Description

, 1961 F. w. E. HOESELBARTH WEAVING WITH DOUBLE WIRE MOTION April 25 2 Sheets-Sheet 1 Filed Feb. 28, 1958 INVENTOR ATTORNEYS 1961 F. w. E. HOESELBARTH 2,981,292

WEAVING WITH DOUBLE WIRE MOTION April 25 2 Sheets-Sheet 2 Filed Feb. 28, 1958 INVENTOR flaw? wz/mesezadrfl United States Patent WEAVING WITH DOUBLE WIRE MOTION Frank W. E. Hoeselbarth, Carlisle, Pa., assignor to C. H.

Masland & Sons, Carlisle, Pa., a corporation of Pennsylvania Filed Feb. 28, 1958, Ser. No. 718,309

11 Claims. (Cl. 139 -39) The present invention relates to processes of weaving pile fabric, particularly carpets and rugs.

This application has been divided and the subject matter relating to the fabric is embodied in application Serial No. 825,099, filed July 6, 1959, for WovenFabric.

A purpose of the invention is to strengthen and support the pile of a pile fabric by providing interlocking of a plurality of staggered pile projections.

A further purpose is to strengthen and support a pile projection formed over a wire introduced with an upper Weft by a pile projection formed over a wire introduced with a lower weft and vice versa.

A further purpose is to stagger in the face of a pile fabric one set of piie projections raised over alternate upper wefts with another set of pile projections rising between adjoining pairs of adjoining upper wefts.

A further purpose is to stagger, in the pile of a pile fabric such as a caipet or rug, one set of pile projections raised over alternate upper wefts and bound beneath spaced upper wefts, another set of pile projections raised over intervening alternate upper wefts and bound beneath spaced upper wefts, and a third set of pile projections rising in the pile between pairs of adjoining upper wefts and bound beneath such adjoining upper wefts.

A further purpose is to provide mutual support in the pile of a pile fabric by one set of pile projections raised over alternate upper wefts and bound beneath spaced upper wefts, a second set of pile projections raised over intervening alternate upper wefts and bound beneath spaced upper wefts, and a third set of pile projections raised between spaced pairs of adjoining upper wefts and bound beneath such adjoining upper wefts, and desirably also a fourth set of pile projections rising between intervening spaced pairs of adjoining upper wefts and bound beneath such upper wefts.

A further purpose is to form in a particular pattern area one set of mutually supporting pattern projections rising between pairs of adjoining upper wefts and bound beneath such adjoining upper wefts, and pile projections which rise over at least two adjoining nip-per wefts and are bound beneath upper wefts on either side.

A further purpose in the above fabric is to make one set of pile projections cut and the others uncut.

A further purpose is to produce in the same pile fabric a first area having one set of pile projections rising over alternate upper wefts and bound beneath spaced upper wefts, and a second staggering set of pile projections rising over intervening alternate upper wefts and bound beneath spaced upper wefts, and in a second pattern area of the same fabric using the same pile warp ends to form one set of pile projections rising between spaced alternate pairs of adjoining upper wefts and bound beneath adjoining upper wefts, and a second set ofpile projections rising between intervening spaced alternate pairs of pile and bound beneath such adjoining pile projections.

A further purpose is to produce in the same pile fabric such as a carpet or rug, one pattern area having one set of pile projections which rise over spaced alternate upper 2,981,292 Patented Apr. 25, 1961 wefts and are bound beneath spaced upper wefts, and the second set of pile projections which rise over intervening alternate upper wefts and are bound beneath spaced upper wefts, and in the same fabric using the same pile neath upper wefts on either side thereof.

A further purpose is to produce in a pile fabric, such as a carpet or rug, a first pattern area having a first set of pile projections which rise in the pile between spaced intermediate pairs of adjoining upper wefts and are bound beneath such adjoining upper wefts, and a second set of pile projections which rise in the pile between intervening alternate pairs of adjoining upper wefts and are bound beneath such adjoining upper wefts, and using the same pile warp ends in another pattern area to produce a first set of pile projections which rise in the pile between pairs of adjoining upper wefts and are bound beneath upper wefts on either side thereof.

Further purposes appear in the specification and in the claims.

In the drawings I have chosen to illustrate a few only of the many embodiments in which the invention may appear, selecting the forms shown from the standpoints of convenience in illustration, satisfactory operation and clear demonstration of the principles involved.

Figure l is a standard waipwise weave diagram showing one fabric according to the invention.

Figures 2 to 5 are views similar to Figure 1 but showing variations.

Describing in illustration but not in limitation and referring to the drawings:

The features of the invention can be applied in Wilton or Brussels carpet, and also in some cases in velvet or tapestry. I

In the prior art, mutual support of pile projections has been obtained by using staggered sets of pile pro jections woven over adjoining wefts of similar character, such as upper wefts, and also by use of floats combined with normal pile;

By the present invention, however, it is possible to obtain much closer support by staggering a series of pile projections formed over upper wefts with a series of pile projections formed over the next lower wefts, so that two staggered pile projections or two mutually supporting pile projections occur in the same cycle, instead of in successive cycles.

It is also possible by the present invention to make uneven repeats in a staggered section of pile projections, for example two pile projections formed over upper wefts, then three pile projections formed over lower wefts, so that throughout the repeat a changing relation occurs between a pair of pile projections formed over lower wefts which have between them a pile projection formed over an upper weft and then a pair of pile projections formed over lower wefts which have no pile projection formed over an upper weft between them.

It is also possible according to the present invention to form a series of pile projections over lower wefts or, to express it another way, between adjoining upper wefts, and to raise between alternate pairs of such pile projections one set of pile warp ends, and between intervening alternate pairs of such pile projections another set of pile warp ends so'that the support is provided by pile warp ends which create different effects in different rows;

The contrast can be particularly pronounced where one In some cases a construction having excellent mutual support of pile projections with greater variety in effect is obtained by raising two staggered sets of pile projections between adjoining wefts, and then raising also two staggered sets of pile projections over staggered upper Watts and binding them beneath spaced upper wefts on either side.

I The invention makes it possible to obtain cut and uncut pile of widely different character in the same area. For example, it is possible to produce floats over two adjoining upper wefts which are uncut, and pile projections which may be cut rise between adjoining upper wefts and bound beneath such adjoining upper wefts.

It is also possible to provide combinations of effects by two sets of pile projections in different pattern areas, one of which may be cut and the other uncut, one of the pattern areas including staggered pile projections, one of which is raised over alternate upper wefts and the other over intervening alternate upper wefts, and in another area to provide staggered pile projections of two sets, one of which is raised between staggered spaced sets of adjoining upper wefts and bound beneath such upper wef-ts and the other between intervening staggered spaced sets of upper wefts and bound beneath such adjoining upper wefts.

It is possible according to the invention to combine in the same fabric one pattern area having a staggered first set of pile projections raised over alternate Upper wefts and bound beneath spaced upper wefts, and a staggered second set of pile projections raised over intervening alternate upper wefts and bound beneath spaced upper wefts, and in a second pattern area to provide a staggered relationship between one set of pile projections rising between adjoining pairs of adjoining upper wefts and another set of pile projections rising above two supporting upper wefts and bound beneath upper Wetts on either side.

Considering now the drawings in detail, in several of the forms of the invention I illustrate a first set of binder warp ends 20, a second set of binder warp ends 21, a set of stutter warp ends 22, pile warp ends 23 of one set, pile warp ends 24 of another set (and in some cases also pile warp ends 25 of a third set and pile warp ends 26 of a fourth set). The warp ends are interwoven by upper or binding wefts 27, which are above the stutter warp ends as well known in carpets and rugs, and lower or back watts/28 which are below the stufr'er warp ends.

The question of whether a single set of binder warp ends or two sets of binder warp ends are interwoven in the back of the fabric is unimportant from the standpoint of the present invention. It is also unimportant whether the wefts are inserted singly or in simultaneous pairs.

In the weave according to the invention, there are two essential steps in forming the backing and raising the pile, although more than two steps will usually be required to form a pile repeat.

In the step are shown at the extreme left in Figure l, pile warp ends 24 are fully raised, and binder warp ends 21 are raised hall way, forming an upper shed 30, while all other ends are lowered, forming a lower shed. A shot of upper or binding weft 27 is inserted in the lower shed, and a wire 31 of one particular character is inserted in the upper shed. For the purpose of identification the wire 31 is generally referred to herein as the wire inserted with the upper or binding weft.

, In the next step of the cycle, binder warp ends 20 remain down, and all other warp ends are raised half way, forming a lower shed and any end to be placed over a Wire is fully raised at that point, forming an upper shed. A shot of lower weft 28 is inserted in the lower shed and a wire 32 is inserted in the upper shed. The wire 32 is referred to herein for identification usually as the wire inserted with the lower weft. However, in some cases the wire 32 is inserted with a mispick, and where elsewhere reference is made to a wire inserted with the lower 4 weft, it is intended to include a wire inserted with a mispick.

In order to make eiiective use of the invention, the wire 31 inserted with the upper weft is desirably of one character, and the wire inserted with the lower weft is of a distinctly different character, for example, one cutting and one noncutting, one high and one low, one wavy and one straight, one wavy of one height or character and another wavy of another height or character, one straight and one flag, or some combination of these. It is of course contemplated that successive wires inserted with the upper wefts may be of ditferent characters, as for example difiering in height or differing in curvature of waviness, and successive wires inserted with lower wefts may likewise be variant in some such manner. It will be evident, however, that for greatest advantage the difference between pile projections formed over wires inserted with upper wefts and pile projections formed over wires inserted with lower wefts should be aggravated by difference in characters of the Wires themselves.

The principles of the invention are applicable in some cases to weaving of velvet carpet, but in many cases it will be preferable to apply the invention to Wilton weaving where a jacquard mechanism is used. Thus in Figure 1, illustrating 21 Wilton carpet, there are three pattern areas shown, designated as A, B and C. It will be understood that each of these pattern areas will normally be much more extensive than that shown, but to economize on space only a limited number of pile projections is illustrated without attempting numerous repeats.

In area A, pile warp ends 23 rise over alternate wires 31' and 31 which are above alternate binding wefts 27' and 27 and these pile projections which in this case are shown as being uncut are bound beneath spaced binding wefts 27. Pile warp ends 24 rise in pile projections, in this case uncut, which are over intervening

alternate wires

31 and 31 which are above intervening

alternate binding wefts

27 and 27 and are bound beneath spaced binding wefts.

In the pattern area B, pile warp ends 23 rise above adjoining

wires

31 and 31 which were introduced with adjoining binding wefts 2.7 and 27", and are bound in on opposite sides of binding

wefts

27 and 27 beneath the next binding wefts. These pile projections, however, pass under the intervening wire 32' inserted with a lower weft, and thus are not cut by this cutting wire but form an uncut float in an area having cut pile. On the other hand, pile warp ends 24 rise between adjoining

binding wefts

27 and 27 and extend over cutting wires 32' in this area to form relatively high cut pile, since the cutting wires 32 are higher than the noncutting wires 3-1.

On the other hand, in pattern area C as determined by the jacquard mechanism, pile warp ends 23 rise between spaced pairs of adjoining binding wefts and extend over wires 32 in this case cutting wires, and pile warp ends 24 rise between intervening spaced pairs of adjoining binding wefts over wires 32 in this case cutting wires. Between each point where pile warp ends appear in the pile projections in pattern area C, they remain in the back beneath two upper wefts in a stretch 35.

In Figure 2 I illustrate a variation in a fabric according to the invention which has a Staggered relation between pile projections, and a repeat in the staggered relation. Thus in this case pile warp ends 24 pass over wires 32 introduced with the lower wefts, rising between and bound beneath adjoining binding wefts 27 throughout. The wires 32 are high cutting wires in this particular instance. Pile warp ends 23 on the other hand rise over alternate wires 31 introduced with the binding Wefts which are in this case low straight noncutting wires, and are bound beneath spaced binding wefts. Thus it will be seen that between two successive high pile projections 36 and 37 there Will be a staggered and supporting low pile projection 38 which crosses at points 40, but between pile projections 37 and the next pile projections 41 there are no crossed lower pile projections, tending to give firm support for some pile projections and not for others, and thus producing an alternating or repeat effect.

In some cases it is desirable to have pile projections of a still different character appear between the pile projections 37 and 41 and at corresponding points throughout the fabric. With this in view an additional frame of pile warp ends 25 is inserted in Figure 3 which rise over wires 31 inserted with binding wefts which are alternating and intervening between the binding wefts over which the pile frame 23 rises in the pile.

Thus there are, successively in order throughout the repeat, pile projections 36, pile projections 38, pile projections 37 and pile projections 42 formed by the new frame 25. File projections 38 which are low and noncutting in this case stagger with respect to low and noncutting pile projections 42- and cross and support them at points 43 above the back of the pile. Likewise pile projections 38 and 42 together cross and support pile projections 36 and 37 which are relatively higher and in this case cut.

In some cases the high pile projections are to advantage provided by two different frames, which of course will suitably be of different color where desired. Thus in Figure 4-, pile warp ends 24 rise over wires 32 introduced with lower wefts to form pi-le projections 44 which are bound beneath two adjoining binding wefts 27 and which provide stretches 35 of pile buried in the back. In intervening staggered relation are pile projections 45 which are similarly raised over the intervening wires 32 introduced with the lower wefts, and bound beneath two spaced binding wefts at each side. The structure to this extent resembles the structure in area C of Figure 1. Superimposed on this however, are loops 38 suitably relatively lower, formed by pile warp ends 23, and staggered intervening loops 42 formed in this case by the additional frame 26. There is thus crossing at numerous points 46 which provide lateral support for the high pile projections.

In some cases, certain areas of the fabric of the present invention will be provided with high, low or intermediate floats as desired, subject to the jacquard control.

In order to illustrate that the weave of the invention can be produced on a one-shot basis and also that a single binder set 21 can weave in opposition to the stuifer warp 22, I illustrate in Figure 5 a one-shot weave which inserts the wires 31 with the binding wefts 27, and which inserts the wires 32 in a second shed'in which no pick is introduced, and which can be described as a mispick. Thus from the standpoint of shedding there are two steps in the cycle which are as follows:

In the first step binder warp ends 21 are raised half way, stuffer warp ends 22 are lowered and all pile warp ends to be bound are lowered, forming a lower shed. All pile warp ends to be raised over the wire inserted with the binding weft are raised. Wire 31 is inserted in the upper'shed and binding weft 27 is inserted in the lower shed. The lay beats up the weft and the wire.

In the second step all ends to be raised over the wire inserted between binding wefts are fully raised, and the other pile warp ends are lowered either half way or fully (it does not matter in this case). No weft is inserted. Wire 32 is inserted in the uppershed. The lay heats up the wire.

As shown in Figure 5, using wavy noncutting wires 32 inserted between binding wefts and straight noncutting wires inserted with the binding wefts, pile warp ends 24 form high :fioat loops 4-7 over five wires and two binding wefts, being bound between binding wefts on either side, while in the same area pile warp ends 23 rise only over a single wire 31 introduced with 'a binding weft to form loop 48, or extends below the wire and above the upper weft to form low float 51.

In another area pile warp ends 23 at some position across the fabric form high =fi0ats 52 over three wires and two binding wefts, bound beneath binding wefts at either side, or form low float loops 53 beneath the wires and above the two adjoining binding wefts as shown. In other areas normal pile loops 54 raised between the two adjoining binding wefts over a wire introduced between wefts stagger with loops 55 raised over a binding weft and over a wire introduced with a binding weft and bound beneath alternate binding wefts, in the manner shown in Figure 2.

It is unimportant from the standpoint of the present invention whether an end of each of the pile frames appears in every dent or in a special thread-in, for example with lateral variation in density or alternating of frames in various dents. It is also unimportant from the standpoint of the present invention whether each of the frames is of different color or different shade or whether the structural advantages of the invention are used even when the different frames are of the same color.

It will be evident of course, that where wires are to be introduced with every weft it is best to use a double wire motion loom introducing one wire from the left and one wire from the right or vice vers-a.

In view of my invention and disclosure variations and modifications to meet individual whim or particular need will doubtless become evident to others skilled in the art, to obtain all or part of the benefits of my invention without copying the process shown, and I, therefore, claim all such insofar as they fall within the reasonable spirit and scope of my claims.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

l. The process of weaving a pile fabric, which comprises interweaving together binder warp ends, stuffer warp ends and pile warp ends with wefts at least some of which are binding wefts, inserting a wire with each binding weft and inserting a wire between binding wefts, raising one set of pile warp ends in a particular pattern area over each of the wires inserted between binding wefts and binding them beneath adjoining binding wefts on opposite sides of such wire, raising a second group of pile warp ends in the same pattern area over alternate wires inserted with binding wefts and binding them beneath alternate binding wefts on either side of such wires, and raising a third group of pile warp ends in the same pattern area over intervening alternate wires inserted with binding wefts and binding them beneath intervening alternate binding wefts on opposite sides of such wires, whereby a sequence of pile projections in staggered relation is formed consisting of a first pile projection, a second pile projection, a first pile projection and a third pile projection and then a repeat.

2. The process of weaving a pile fabric, which comprises interweaving binder warp ends, stulfer ends, pile warp ends and wefts at least some of which are binding wefts, inserting a wire with each binding weft, inserting a wire between binding wefts, the wires inserted with the binding wefts being of distinctly different character from the wires inserted between wefts, raising a first group of pile warp ends in a particular pattern area over each wire inserted between binding wefts, and binding them on op posite sides thereof beneath adjoining binding wefts, raising a second group of pile warp ends in the same pattern area over each alternate wire inserted with a binding weft and binding them beneath alternate binding wefts on opposite sides thereof, and raising a third group of pile warp ends in the same pattern area over each alternate intervening wire inserted with a binding weft and binding them beneath alternate intervening binding wefts on either side thereof, whereby a repeat sequence of staggered pile projections is formed consisting of a first pile projection, a second pile projection, a first pile projection and a third pile projection.

3. The process of weaving pile fabric, which comprises interweaving binder warp ends, stuifer warp ends, pile warp ends and wefts at least some of which are binding wefts, inserting a wire with each binding weft, inserting a wire between binding wefts, raising one set of pile warp ends in a particular area over each alternate wire inserted between binding wefts and binding each pile projection beneath binding wefts, in the same pattern area raising a second set of pile warp ends over each intervening alternate wire inserted between binding wefts and binding the pile projection beneath binding wefts, and in the same pattern area raising a third set of pile warp ends over alter nate wires inserted with binding wefts and binding them beneath alternate binding wefts on either side.

4. The process of weaving a pile fabric, which comprises interweaving binder warp ends, stufter warp ends, pile warp ends and wefts at least some of which are binding wefts, inserting a wire with each binding weft, inserting a wire between binding wefts, raising one set of pile warp ends in a particular pattern area over alternate wires inserted between binding wefts and binding the pile projections beneath adjoining binding wefts, in the same pattern area raising a second set of pile warp ends over intervening alternate wires inserted between binding wefts and binding the pile projections beneath adjoining bind ing wefts, and in the same pattern area raising a third set of pile Warp ends over alternate wires inserted with binding wefts and binding them beneath alternate binding wefts on either side.

5. The process of weaving a pile fabric, which comprises interweaving binder warp ends, stutter warp ends, pile warp ends and wefts at least some of which are binding wefts, inserting a wire with each binding weft, inserting a wire between binding wefts, raising one set of pile warp ends in a particular area over each alternate wire inserted between binding wefts and binding each pile projection beneath binding wefts, in the same pattern area raising a second set of pile warp ends over each intervening alternate wire inserted between binding wefts and binding the pile projection beneath binding wefts, in the same pattern area raising a third set of pile warp ends over alternate wires inserted with binding wefts and binding them beneath alternate binding wefts on either side, and in the same pattern area raising a. fourth set of pile warp ends over intervening alternate wires inserted with binding wefts and binding them beneath binding wefts on either side.

6. The process of Weaving a pile fabric, which comprises interweaving together binder warp ends, stutter warp ends, pile warp ends and wefts at least some of which are binding wefts, inserting a wire of one character with the binding wefts, inserting a wire of a different character between binding wefts, raising a first set of pile warp ends over alternate wires inserted between binding wefts and binding them beneath binding wefts, raising a second set of pile warp ends in the same pattern area over intervening alternate pile wires inserted between binding wefts and binding them beneath binding wefts, and raising a third set of pile warp ends in the same pattern area over alternate wires inserted with binding wefts and binding them beneath spaced alternate binding wefts.

7. The process of weaving a pile fabric, which comprises interweaving together binder warp 7 ends, stutter warp ends, pile warpends and wefts at least some of which are binding wefts, inserting a Wire of one charac ter with the binding wefts, inserting a wire of a different character etween binding wefts, raising a first set of pile warp ends over alternate wires inserted between binding wefts and binding them beneath binding wefts, raising a second set of pile warp ends in the same pattern area over intervening alternate pile wires inserted between binding wefts and binding them beneath binding wefts, raising a third set of pile warp ends in the same pattern area over alternate wires inserted with binding wefts and binding them beneath spaced alternate binding wefts, and

raising a fourth set of pile warp ends over intervening alternate wires inserted with binding wefts and binding thern beneath binding wefts on either side.

8. The process of weaving a pile fabric, which cornprises interweaving together binder warp ends, stutter warp ends, pile warp ends and wefts at least some of which are binding wefts, inserting a wire with each binding weft, inserting a wire between binding wefts, in one pattern area raising one set of pile warp ends over alternate wires inserted with binding wefts and binding them beneath spaced binding wefts, in the same pattern area raising another set of pile warp ends over intervening alternate wires inserted with binding wefts and binding them beneath intervening alternate binding wefts, in a second pattern area raising one set of pile warp ends over wires inserted between binding wefts and binding them beneath adjoining binding wefts, and in said second pattern area raising another set of pile warp ends over two adjoining wires inserted with binding wefts and under an intervening wire inserted between binding wefts and binding them beneath spaced binding wefts on either side of said adjoining wires.

9. The process of weaving a pile fabric, which comprises interweaving together binder warp ends, stuffer warp ends, pile warp ends and wefts at least some of which are binding wefts, inserting a wire with each binding weft, inserting a wire of a different character between binding wefts, in one pattern area raising one set of pile warp ends over alternate wires inserted with binding 1 wefts and binding them beneath spaced binding wefts, in the same pattern area raising another set of pile warp." ends over intervening alternate wires inserted with binding; wefts and binding them beneath intervening alternatei binding wefts, in a second pattern area raising one set of pile warp ends over wires inserted between binding wefts and binding them beneath adjoining binding wefts, and in said second pattern area raising another set of pile warp ends over two adjoining wires inserted with binding wefts, and under an intervening wire inserted between binding wefts and binding them beneath spaced binding wefts on either side of said adjoining wires.

10. The process of weaving a pile fabric, which coniprises interweaving binder warp ends, stuffer warp ends, pile warp ends and wefts at least some of which are binding wefts, inserting a wire with each binding weft, inserting a wire of different character between binding wefts, in one pattern area raising one set of pile warp ends over adjoining wires of one character and under an intervening wire of the other character and binding said pile warp ends beneath spaced binding wefts, in said pattern area raising another set of pile warp ends over successive wires of said other character and binding them beneath binding wefts on either side, in another pattern area raising one set of pile warp ends over alternate wires inserted between wefts and binding them beneath adjoining binding wefts and in said second pattern area raising another set of pile warp ends over intervening alternate \w'res inserted between binding wefts and binding them beneath adjoining binding wefts.

11. The process of claim 10, in which the wire of one character is cutting and the wire of the other character is noncutting.

References Cited in the file of this patent UNITED STATES PATENTS 2,685,894 Pariin Aug. 10, 1954 2,708,457 Gebert May 15, 1955 2,720,222 Hoeselbarth Oct. 11, 1955 2,759,495 Mosland Aug. 21, 1956 2,796,088 Hoeselbarth June 18, 1957 2,836,201 Hoeselbarth May 27, 1958 2,853.103 Mincher et a1. Sept. 23, 1958 UNHED STATES PATENT OFFICE QERTEFEQATYE OF CORRECTION Patent No e acuees April 25, 1961 Frank W E0 Hoesclicarth it is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected belowo Column 1, line 69 before "and" insert projections column line 5'7 for "are" read as 1 I Signed scaled this 10th day of October 1961.

(SEAL) Attest:

ERNEST W. SWIDER DAVID L. LADD Attesting Officer v Commissioner of Patents USCOMM-DC