US2643435A - Thread trimming machine - Google Patents

Description

J1me 1953 c. B. SCRANTCN ET AL THREAD TRIMMING MACHINE- 2 Sheets-Sheet 1 Filed July 18, 1949 INVENTORS C unono BRucE SCRANTON CARL T BREWER ATTORNEY June 30, 1953 c. B. SCRANTON ET AL 2,643,435

THREAD TRIMMING MACHINE Filed July 18, 1949 2 Sheets-Sheet 2 77 INVENTORS 7f Cunano BRUCE SCRANTON FIG. 8. CARL '1'. BREWER ATTORNEY Patented June 30, 1953 UNITED STATES PATENT OFFICE THREAD TRIMMING MACHINE Clifford Bruce Scranton and Carl T. Brewer, St. Louis, Mo.; said Scranton assignor, by decree of distribution, to Helen B. Scranton Application July 18, 1949, Serial No. 105,296

(Cl. 26-l0.i)

19 Claims. 1

This invention relates to improvements in thread trimming machines, and more particular ly to a relatively light weight, powered thread trimmer unit particularly designed for use in garment factories and in other textile production fields in which there is a requirement for trimming away unwanted or protuberant threads, as from the selvage edges or finished seams of various fabric articles.

These designers are fully aware that certain devices have heretofore been offered to the trade for thread trimming purposes; however as far as is known, such devices are large, high in cost and are designed for permanent, stationary installation. Many such devices require the use of one hand of the operator for manipulation or control of parts of the trimming machine, thus resulting in a slow, inefficient and ineffective result, often reflected in poor workmanship.

To summarize the present invention and to a motor for driving such device and the disc,

and an appropriate filter, such as a bag-type element for separating and entrapping thread clippings and other solids against discharge by the machine. The present improvements are directed particularly to such a combination, together with an improved rotary cutter and shear element coacting therewith, and thread gathering provisions of improved character, which materially increase the speed of operation and enhance the certainty and cleanness of thread clipping action.

Among the many objects and advantages of the present improvements may be noted the highly portable and self-contained character, since the parts of the assembly may be combined in a unit weighing no more than 30-35 lbs.; a low cost of operation, comparable to that of an ordinary electric fan; absolute cleanliness due to complete entrapment of clipped threads, lint and the like; lack of any installation expense; permanent lubrication provisions and increased production resulting from the fact that both hands of the operator are left free to manipulate the work incident to trimming unwanted threads from a garment or the like.

The foregoing and numerous other objects and advantages will more clearly appear from the following detailed description of a preferred embodiment of the improvements, particularly when considered in connection with the accompanying drawing, in which:

Fig. 1 is a vertical side elevational view of a thread trimmer unit embodying the present improvements;

Fig. 2 is a sectional view taken in a transverse vertical plane, and particularly located by line 2-2 of Fig. 1;

Fig. 3 is a somewhat enlarged elevational view looking inwardly of the open end of the suction nozzle or head, substantially in the plane of a rotary cutter element, Fig. 3 being particularly located by line 3-3 of Fig. 1;

Fig. 4 is a fragmentary sectional view of the cutter disc and adjacent elements together with portions of the suction head, as viewed along a staggered plane indicated by line 4- 3 of Fig. 3;

Fig. 5 is a fragmentary elevational view taken edgewise of a portion of the periphery of a cutter disc, embodying certain of the present features of improvement; 7

Fig. 6 is a fragmentary end view of a housing and nozzle portion of a somewhat modified form of thread trimmer assembly;

Fig. 7 is a sectional view, taken in a horizontal plane, through the suction head or nozzle of the machine, and particularly along line 1-1 of Fig. 6;

Fig. 8 is a fragmentary elevational view taken at one side of the nozzle to show a threadreceiving port, Fig. 8 being identified as to location with line 8-8 of Fig. 6, and

Fig. 9 is a somewhat enlarged, fragmentary, elevational view of aseries of thread-receiving suction openings in the face of the nozzle, and particularly at the left hand side of the shear plate structure shown as a whole by Fig. 6.

Referring now by characters of reference to the drawing, first in description of the assembly shown by the first sheet of drawing, the improvements are embodied in an enclosed self-contained power unit for thread trimming purposes, which is of a portable, light weight type, the enclosure or housing of and for which is generally indicated at Ill, and as shown, may be comprised of a light weight aluminum alloy casting the shape and proportions of which are readily seen from Figs. 1 and 2. This casing or housing is characterized by a rounded upper portion, is of a length considerably exceeding its width, and is or may be as shown, of openbottcm form. The opposite end walls are indicated at H, which may be referred to as the back of the unit, and i2 considered for present purposes as the front or work end of the unit. The opposite side walls 53 and i i are below the rounded top portion, of substantially planar form, and located within and as a part of the wall I4,

is a removable closure in the form of a detachable plate l5. Securement means for the plate l5 are shown as a pair of keyhole slots IS with companion screws IT, a recess in the upper margin of plate i5, and a wing nut 2| engaging a fixed threaded stud in such manner that upon backing oif the nut 2| and screws H, the plate [5 is readily removed. Since the trimmer is preferably operated at a substantial speed, say of the order of 3750 R. P. M. but without limitation to any particular speed range, it has been found desirable to provide the lower margins of the walls of housing ill with extensions or feet 22 attached to each of Which is a resilient supporting pad 23 tending to dampen transmission of any vibration from the unit to a subjacent support such as a Work table.

Supported within and preferably dependently from the upper portion of the housing H3 is a motor M, the speed and other ratings of which will be dictated by available current and desired field of usage. The motor M is supported from the top of the housing by threaded studs 24 in the example shown. The motor M will usually be of single phase type characterized by so-called oilless bearings so as to minimize lubrication requirements and obviate any oil spoilage of the fabric in work. A dupl x current supply lead is indicated at 25, suitably bushed by element 26, the circuit including a microswitch or other onand-off control, as indicated at 21. Internally of the housing Hi, conventional conductors 28 complete the circuit to a terminal or junction box 39 of the motor.

The motor shaft S is connected through a coupling C to a shaft 3| journalled as through a ball-race assembly 32 carried by an internal partition 33. This latter forms a part of either a separate casting, or is a portion of the structure H) to constitute with a peripheral wall 34, a volute or fan housing enclosing a vane type centrifugal blower or fan, the vanes of which are indicated at 35, and each of which extends substantially inwardly to the hub portion of th fan which latter is secured to and carried by shaft 3|. It should be noted that the construction of the vanes 35 as well as the hub and other parts of this fan is such as to minimize, in fact virtually to preclude entrapment within the fan of pieces of cloth, thread trimmings or other similar foreign material such as lint. Otherwise expressed, the vanes and hub structure of the fan being characterized by no sharp corners or recesses, are self-clearing.

It is best seen from Fig. 2 that the stationary elements of the fan or blower are of volute form and that the air and solids carried thereby are displaced into a discharge conduit 36 directed through a detachable coupling 3? into a removable filter bag 40. This latter is provided with a removable end clamp ll' of a type which is well known and requires no specific description, so that upon removal of the door l5, the bag it, which may be in the form of a short conventional vacuum bag, may be readily cleared and emptied of its accumulated trimmings, lint, etc.

It will have been noted as a preference that the inlet eye of the fan or blower is immediately adjacent the outer wall l2. This latter is provided with an opening shown as circular and indicated at 2, and over such opening is detachably mounted a nozzle head in the nature of a hollow housing extension and generally indicated at 53, containing as will appear, the

cutting element proper. The head 43 is of a hollow chambered type and of a generally cuplike form. Its peripheral shape will best appear from Figs. 2 and 3, being in a preferred form. of a partly circular periphery but vertically protuberant to provide an inverted V-shape portion which is curved adjacent to and on opposite sides of a thread-receiving port to be described, the convex shoulder portions of the protuberance referred to, being indicated at M. The nozzle head 43 is provided with a planar flange extension 45 suitably apertured for the reception of attachment screws 38, if desired a suitable gasket (not shown) being employed between the flange 45 and the seat therefor about the open ing 42.

The nozzle head or hollow housing for the cutter may consist of a light weight casting of a material such as an aluminum alloy, and is provided in its uppermost portion with a relatively wide thread-receiving port of slot form and indicated at 41, the major dimension of which is along a horizontal median of the unit, and the width of which will best appear from Fig. 3, while its preferred length is shown by Fig. 1. The port for initial introduction of threads and the like into the cutting region, is thus horizontally presented to the operator at the top of head 43, and constitutes a horizontal leg of the thread passage considered as a whole, which is complemented by a vertical slot or passage 48 best seen from Fig. 3. The sides of the opening 61 forming the port passage are distinctly convergent toward, and lead into the 7 thread slot 48 which as noted, constitutes the vertical leg of the thread passage considered as a whole. Due to the thickness of the top wall of the member 43, it will appear that the sides of the port and port passage in the region distinctly converge toward and serve to direct the threads into the slot .8, whence they are fed by movement of the garment or fabric by the operator inwardly to the cutting zone, as will later better appear. The combination of the port and port passage with the slot results in a substantially Y shape opening as will appear from Fig. 3, from which it will also be seen that the slot Gil extends downwardly sub stantially along a produced radius of the cutter disc to be described, and is of an inward extent such as to direct the threads well into the serrate periphery of the cutter.

The passage 48 heretofore described as to purpose and location,. is formed in a closure plate 58 of the nozzle head 43 such plate forming a detachable part thereof. The plate is preferably formed of a relatively hard spring metal such as steel, and lies in a plane immediately adjacent the plane of the cutter disc now gen erally indicated at 5!. The disc is characterized by peripheral sawlil;e teeth 52 which will be described later in further detail. The disc 51 is rotatively mounted so as to be powered by the motor M, so that the latter serves as a power source for both the centrifugal blower and the disc 5i. The shaft of the blower indicated at 3!, extends into the hub and a hub sleeve 35A of the blower, and extends outwardly beyond the hub sleeve to provide an integral trimmer disc shaft portion 53, the shaft 3! being detachably secured to the hub sleeve 35A as through a set screw 54. The shaft portion 53 is supported and journalled in an anti-friction bearing exemplified by a ball race assembly carried by a bearing arm 56 which may constitute an integral interior radial extension of the casting constituting the major element of the nozzle head 33. The outer end of shaft portion 53 extends into a hub 51 of the cutter disc, securement between the hub and shaft portion being effected in any suitable manner, for example, by a set screw 57'. This arrangement facilitates removal of the cutter disc for service or replacement purposes with easy access thereto upon removal of the plate 50.

It is greatly preferred that the cutter disc 5! present a substantially unobstructed outer face so as to enable the cutter disc to operate in close adjacence to the 'plate 5t, and to this end, attachment of the disc 5| to its hub ill is effected by a plurality, shown as three, or flat head screws 58 fitted into conforming plate recesses and in tapped openings therefor in the hub 5'].

The outer plate 50 clcsing the otherwise open end of the suction nozzle head 43 serves not only the purpose or a closure in this region, and further that or" defining the slot 48, but by reason of its proximity to the cutter disc 5!, the inner margins of the slot t8 coact with the periphery of the disc e i, in the manner of a shear plate. This arrangement results in a distinct scissors or shearing action on the threads introduced through the throat cl and slot 48. To this end one or both of the margins of the slot 48 may be ground or bevelled to provide an edge, if desired.

It has been found highly advantageous to maintain an optimum distance relation between the cutting regions of the plate 58 and the disc ill, and for this purpose to provide a precision space adjustment particularly between the slotted region of the plate 59 and the teeth of the disc. Such a space adjustment consists in the present disclosure, of an adjusting screw indicated at Elli, which extends through an aperture 65 in plate and into threaded connection with an inwardly extended lug or arm 62 provided with a tapped opening to receive the screw til. From this it will be apparent that upon tightening screw lit, the space relation between the plate till and cutter disc will be decreased, with an increase in such space relation by backing off the screw be, in coaction with the resilience of the plate.

Proceeding now to a more particularized description of a preferred form of cutter disc, this latter as above briefly noted, is preferably of a hardened or tool steel, in the interest of minimization of replacement and service attention. It is by preference so formed that its side nearest the slotted plate at is smooth and planar in character, this planar characteristic extending outwardly through the teeth 52. The opposite sides or" the several teeth are characterized by a distinct bevel, with a tooth angle preferably Within the range of fifty to seventy degrees, and in current commercial models are characterized by an angle of sixty degrees. Further, the teeth are so formed as to present a substantial helix angle which is regarded as important in materially increasing the life of the disc. The bevel and tooth angle as described'are best seen by reference to Fig. 5, showing an enlarged fragmentary portion of the periphery of the cutter disc.

A further feature of the cutter head assembly which may be said to include the suction nozzle or housing ts together with the spring steel plate at and immediately related parts, is found in the provision in this plate of one or more ports, shown as circular openings and indicated at 63. But for such provision, it will appear that when suction is applied solely through the port ll and slot 48, a dead space or pocket might under certain conditions result in the lower portion of the suction head chamber. Provision of one or more ports such as 63 opposite the thread port and passages, assures the entrance of a portion of the air to the h'ead :33 in a region opposite the thread apertures, and thus serves effectively to clear the entire head of any accumulation of trimmings or lint, at all times.

Although the operation of the machine is believed to have been rendered fully apparent from the foregoing description of its parts and their relation, it may be noted for completeness that, assuming switch ill to be closed and the motor M to be operating, there will obviously result a rotation of the centrifugal fan or blower rotor identified with the vane structure 35, with the eliect of inducing a high-speed flow of air into the ports and passages dl', and 63. With the machine thus in operation, the operator is free to use both hands, and grasps the seam, hem regions, selvage edge or the like in such manner that the threads to be trimmed are presented outwardly of the work, the line of such threads being usually presented outwardly of and along the line of the seam or edge of the fabric article. The line of excess threads is now brought downwardly into the thread receiving port ll, and as the supporting garment portion is moved downwardly along the nozzle or head is, the high speed stream of air entering at 4'7 and through the slot as serves to obviate any niceties of individual thread direction as the threads are introduced to the cutting region of the machine. The tapered port and port passage resulting in the throat in the region in and below the slot ll, will as now apparent, serve to bring the threads to be trimmed, into alignment due to the combined thread straightening elfect of the tapered throat in this region and the coacting effect of the powerful suction stream of air flowing inwardly of the nozzle Q3. As the line of threads is brought downwardly into the region of the teeth 52 of the cutter disc, they are neatly and quickly clipped, trimmed or severed between the sharp cutting edges of the teeth and the adjacent margin, sharpened if desired, of the slot ill. The threads now severed, will be carried rapidly into the suction eye of the blower, are thence entrained in the fast air stream through the blower, whence they are discharged with the air through the passage 3d and into the vacuum bag It will be understood of course that other forms of filtering medium may be employed, the bag having been selected for its light weight, ease of replacement, and ease of dumping and cleaning.

It should here be noted that the features of the cutting disc 5! have been arrived at as a result of numerous experiments not only for long life, but for specific adaptability to a clean severance of threads, as distinguished from material such as hair and the like. Furthermore, it has been found highly advantageous to provide for precision adjustment of the space relation between the slctted closure and shear plate 50 and the contiguous cutter disc. This spacing will usually be maintained within a range of one to five thousandths of an inch, and may advantageously be increased somewhat for heavier or coarser threads and fabric trimming. The precision adjustment in this zone is by preference and as now commercially practiced, held to accuracy of one thousand inch or less.

A somewhat modified embodiment of the present improvements is shown by the second sheet of drawing, particularly by Figs. 6 through 9. While the function and purposes of the modified assembly are generally similar to those shown by Figs. 1 et seq., certain structural differences exist, as will be described:

In Fig. 6, i indicates a planar front end wall of a housing structure generally indicated at H, and which is by preference formed or fabricated to include a lifting handle l2, facilitating transportation of the portable unit from place to place, incident to factory usage. Formed as an integral part of the end wall T6 is a fixed, substantially horizontal extension or boss 13, and diametrally opposite the boss 13 is a similar extension 14. As will later appear, these elements serve as parts of the enclosing body of the nozzle or suction head.

Laterally attached to elements 73 and M as through suitable tapped openings and attachment screws '1, is a fixed guide element 16 at the left, and a similar element :1 at the right hand side of the nozzle (Fig. 6). The members i6 and H serve with the bosses l3 and I4, and a front shear plate structure to be described. in completing the enclosure of the chamber within the suction head or nozzle which, as a unit, protrudes from the end wall it of the easing Ii. This casing is or may be identical with the casing or housing l8 shown by Fig. 1. As in the case of the structure shown by the first sheet of drawing, the modification of Figs. 6, et seq. includes a motor, a suction blower, a bag or other filter, and other elements which for present purposes may be considered as identical with these elements as shown by Fig. 1, but which in the interest of minimizing illustration, are omitted from Figs. 6 et seq. In the modified form, a shaft 80 is supported by a ball race 8|, the latter being carried by a bearing arm 82, only a portion of which is shown by Fig. '7, but which may be constituted as an upward integral extension of the boss 14.

A rotary cutter disc 83 is detachably secured to mounting plate 84, as by screws 85, all of which is or may be identical to the corresponding structure shown by a Fig. 4, the set screw 88 serving to attach the hub 84, and hence the rotary cutter disc 83 to the shaft 80.

in the structure of Figs. 6, 7, et seq. a combined end closure for the nozzle and shear plate for coaction with the rotary cutter disc 83, is of sectional character including in the example here selected, four sections numbered from left to right at 9%, Si, 92 and 93. The intermediate frontal area of the nozzle is closed by the plate 92, while the left hand portion of the cutter disc 33 is covered by the section 9| of the shear plate structure, and the otherwise remaining partial opening at the left of the nozzle or suction head is closed by the first section 90.

The fourth section of the shear plate and closure serves to cover the remaining otherwise open and area of the nozzle, this plate being indicated at 93. Attachment of the shear plate sections is effected in the case of the section 92, as by screws 94 extended directly into the fixed boss members 13 and 74, this plate portion thus being shown as non-adjustable, while the remaining shear plate sections are susceptible of variationin their spacing to and from the cut- 8 ter disc in a manner and for reasons later to appear.

The guide member 16 is provided with an undercut or mortised groove for the slidable and accurately guided reception of a correspondingly mortised projection on a slide member 95, such mortise connection being indicated at 95. A similar or identical, except reversed relation prevails by reason of a mortise joint 91 between the fixed guide and closure portion i1, and a companion slide 98.

It is a preference as shown, to locate the two slides and 93 internally of the guide elements cooperating therewith, and to provide each of the latter with a shallow, horizontally extended chamber structure liil at the left (Figs. 6 and 7) and 84 at the right. Each of the slides 95 and 98 is provided with a lateral extension or lug, such elements being shown at )2 on the slide 95, and E23 on the slide 98. Rearwardly of each such extension is a coil compression spring, each of these springs being indicated at ltd, and there being one or a plurality thereof as desired. The outermost portion of each of the chambered parts lilo-482 is provided with a tapped aperture for the reception of an adjusting screw I625. These screws are preferably characterized by a relatively fine thread, and are of precision character so as to provide for an extreme nicety of adjusting move-- ment of the slides 95 and 98, each independently of the other. However, both slides are constrained to movement in directions, either in or out, parallel to the axis of rotation of the cutter disc 83 which of course is also the axis of the shaft to by which the disc is driven.

The outermost face of the slide 95 is so formed and proportioned as will appear from Fig. 6, as to carry the two left hand (Fig. 5) sections 3l9-9i of the shear plate, such attachment be ing effected as by screws Eta, while the right hand (Fig. 6) slide 98 is surmounted by a single shear plate section 93, attachment thereto bcing effected as by screws ifil'.

It will have been noted that the shear plate includes a pair of horizontally aligned thread ports, openings or passages, one of which is formed in adjacent margins of the juxtaposed pair of sections 88 and iii of the shear plate structure, while the other consists of a substantially Y-shape slot, with sides diverging toward the periphery of the cutter disc, this opening being indicated at 58. Although located in a plane at about a right angle to the opening E08, the peripheral portion of the nozzle or head just inwardly of its end face, is provided with a generally V shaped thread port Hi9. This really forms a part or at least a continuation of the opening I98, and since ports I68 and B9 are in right angled walls, they are similarly mutually related. This relation, it may be noted, is closely similar to that prevailing between the portions 4'! and 48 of the l..-shaped slot in the suction head as shown by Figs. 1, 3, and 4 above described.

The thread-receiving opening first generally referred to in respect to the modified structure, is shown in enlarged form by Fig. 9, and includes a linear row of V-shaped openings with inte vening tooth formations, these openings being indicated at Ho, and the intervening teeth at HI. A similar but oppositely arranged series of suction and thread passages is formed in the left hand margin (Fig. 9) of section 9| of the shear plate. In this group the openings, being convergent in form considered in the direction of normal thread movement toward the edge of the cutter disc 83, are indicated at M2 with intervening teeth lit. It will be noted from Fig. 6 that, but for the open area for reception of threads identified with the slots |H3-i!2, and the convergent thread passages Hit-J99, the end of the nozzle or suction head is otherwise imperforate, thus compelling air to be drawn in to the suction of the blower at these two diametrally related zones.

The function of the modified structure last described is now believed generally apparent from the earlier description, but it may be noted for completeness that to bring the shear plate sections 9t-9l closer to the cutting periphery of the cutting disc 83 (which may be considered the same as disc 5|), the left hand adjusting screw I95 will be rotated clockwise (Fig. 6) against the loading of the adjacent spring or springs it i. With the machine at rest, this adjustment may be carried to the extent of contact between these shear plate sections and the disc, the screw then being backed ofi or revcrsely threaded just enough to effect the requisite working clearance, which may be of the order of one half thousandth inch or less if desired. It has been found from experience that a somewhat larger clearance between the shear plate and disc is advisable for best action on coarser threads. It will now be obvious that upon a reverse or counterclockwise movement of the left hand screw I05, the loading of springs HM will urge outwardly the guide 95, and therewith the plate sections 9%! and BI.

A similar relation prevails between the plate section 93 and the disc 83, and the manner of adjustment of the section 93 is identical with that described for the sections 9ii9i. It may be observed that, assuming a clockwise rotation of the cutter dic (Fig. 6) the lowermost and innermost margins defining the passage 1538 may be bevelled or otherwise sharpened for coaction with the teeth of the disc The same is true as to the cutting sides of the teeth formed between the openings H2, such teeth being indicated at iiii, their sides being bevelled or otherwise sharpened as desired.

It will ha appeared that there is a particular advantage in the horizontal alignment of the two thread-receiving ports or, if a single such port be employed, in its location at the left or at the right hand side of the nozzle. This arrangement offers the advantage of enabling the operator to apply tension, between his hands, to a considerable length of scam, strip or like piece of fabric characterized by protuberant threads to be removed by the trimmer, and thus to pass the strip, hem or the like, say from left to right, across the nozzle so as to bring the threads in succession under the action of the infiowing air into the openings ilii-l 12, where they will be cleanly severed and carried through the blower to the bag or other form of filter. For coarser work or other types of fabric, a reverse action may be had by presenting the threads in succession by horizontal movement of the fabric margin, strip or hem, so as to bring same into the suction influence in the region of the opening iilii, thus resulting, as aforesaid, in the removal of the protuberant and unwanted threads.

It will now have appeared that the trimmer unit as described will serve fully to realize the several objectives and advantages above expressed, as well as others implied and stated in the description. Although only two embodiments of the improved machine have been described in considerable detail, it should be noted that such detail is presented in an instructive rather than in any limiting sense, numerous variants being possible and contemplated within the full intended scope of the claims hereunto appended.

We claim as our invention:

1. In a thread cutting machine, a supporting and frame structure, a motor, an air displacement device and a rotary cutter driven by the motor, a hollow head projecting outwardly of the frame structure and substantially free of peripheral obstruction, the head being connected to the air intake side of the displacement device and enclosing the cutter, the head including an end closure plate slotted to provide a tapered thread port converging into a narrow thread shearing slot directed toward and providing an air nozzle directed across the severance region of the cutter, the air displacement device acting to produce an inflow of air through the nozzle, and thread collecting means carried by the supporting and frame structure and connected into the discharge of the displacement device for entrapping and confining severed thread, the hollow head further provided with an open airintake area immediately adjacent the cutter, but spaced from the said thread slot and tending to equalize the flow of air through the space within the head.

2. In a thread cutting machine, a housing, a motor, an air displacement device and a rotary cutter driven by the motor, a hollow head constituting an extension of the housing and in communication with the air intake region of the air displacement device, the hollow head having a substantially planar outermost wall adjacent and parallel to the rotary cutter, said wall being provided with a slot, serving as a linear thread passage extended from the periphery of the hollow head, inwardly at least to the cutting region of the rotary cutter, the outer portion of said slot being formed as a convergent throat, and the inner end as a narrow even width portion forming an air nozzle directed across the edge of the rotary cutter, the air displacement device acting to produce an inflow of air through the nozzle, and the wall being provided with an additional opening in a region opposite the thread passage, serving to direct air inwardly across the edge of the cutter, and tending to equalize air flow into the space within the head and around the cutter.

3. In a thread trimming machine of portable type, a metal housing of elongate form and of a generally rectangular shape along a longitudinal median plane of the housing, the housing being provided with opposite substantially planar end closure portions, a hollow cup-like extension on an upper portion of one of said end closure portions, an electric motor in the housing, a centrifugal blower operatively connected to the motor shaft, a cutter of rotary type driven by the motor shaft and located beyond the blower, a filter bag in a lower portion of the housing and connected with the discharge side of the centrifugal blower, a removable access door in one side of the housing through which the bag may be removed for dumping and cleaning, said cup-like extension being substantially peripherally unobstructed and constituting a suction nozzle having a vertical planar end face closely adjacent the rotary cutter, said nozzle being provided with a slotted thread opening in its periphery, and with a linear thread-receiving port in its outermost end face portion, communicating with said thread opening, said nozzle or extension having a substantially peripheral surface adjacent and extended on both sides of said slotted thread opening, and said thread-receiving port serving as a thread positioning slot and an air jet extended toward the axis of the cutter from the periphery of the nozzle, at least to the actual severance region of the cutter.

4. In a rotary thread cutter assembly, a housing, a nozzle communicating therewith, a rotary cutter element in the nozzle, power means for driving the rotary cutter element, a suction device in the housing, acting to produce an inflow of air in the region of the nozzle and about the rotary cutter, and the nozzle being formed to provide an inwardly tapering entrance throat adjacent the periphery of the cutter, and open- I ing exteriorly of the nozzle for the reception of threads, and converging toward the cutting region of the rotary cutter, thence merging into an even width, thread-holding slot traversing the said cutting region, the nozzle being provided with an open air-intake jet located to direct a stream of air onto the edge of the cutter element, but spaced from said throat so as substantially to equalize the inflow of air about the cutting element.

5. The combination and arrangement of elements as recited by claim 4, but further characterized in that the tapered throat is provided with an entrance port of elongate slotted character, and with its major axis at a substantial angle to the plane of rotation of the rotary cutter, the port having an innermost portion of even width constituting a thread erector and as a jet for intake air.

6. In a rotary thread trimmer, a housing, a power unit and a suction device in said housing, a nozzle head communicating with the suction device, and extended outwardly of the housing so as to be substantially free of peripheral obstruction, a rotary cutter in said head and adjacent an end wall thereof, said head forming a chamber of substantial size within which the cutter operates, the head being provided with a thread receiving slot in its perimeter, and with a converging thread guide below said slot merging into a thread-erecting air jet extended toward the axis of, and at least to the cutting zone of said rotary cutter, the head being further provided with a suction-equalizing opening in a zone opposite the thread guide and slot, and directed across the edge of the cutter.

'7. In a thread trimmer of portable power type, a rotary cutter, a vane-type rotary blower having its inlet in the region of the cutter, a powered shaft for driving the cutter and blower, and means forming an enclosing chamber for the cutter, said chamber having an outer wall closely parallel to the cutter and containing a Y-shaped slot, the upper portion of which forms a relatively wide, slotted, thread entrance port and air nozzle, the inner portion of the slot being formed to provide a second thread passage of narrow, uniform width, extended substantially radially of and closely adjacent the cutter.

8. In a rotary cutter for threads and like materials, an enclosure or housing, suction means in the housing, a rotary cutting element, power means for driving the cutter and suction means, the housing having a relatively wide thread slot of elongate character located to rece ve threads or the like presented thereinto by movement toward the axis of the cutting element, a plate element adjacent and parallel to the rotary cutter, said plate element being formed to provide a narrow, linear thread-straightening passage and air inlet, extended inwardly toward the severance region of the cutter.

9. The combination and arrangement of elements as recited by claim 8, but further characterized in that the thread passage as formed in the recited plate element, is of a substantially Y-shape and extends inwardly substantially through the severance region of the cutter.

10. In a rotary thread cutter of suction type, a suction device, a cutter disc, means for rotating the disc, a stationary enclosure for the disc including a substantially planar plate in parallel adjacence to the disc, there being a thread-receiving slot in the plate, the upper portion. of which is relatively wide constituting a thread holding and erecting device, the inner portion or" the slot being formed to provide a narrow airentrance opening traversing the edge of the cut ter disc, and precision screw-thread means coacting with the enclosure and enabling an accurate adjustment of the distance relation between the assembled cutter disc and the plate.

ll. In a rotary thread trimmer, a housing, a motor, a suction device, a rotary cutter disc, the housing enclosing the cutter disc, a plate detachably carried by the housing as a closure therefor adjacent the cutter disc, means by which the plate is yieldably positioned in parallel relation to the disc, the plate being slotted to provide a thread entrance port, and adjustment screw accessible externally of the housing and connected to the plate and coacting with said yieldable sitioning means to actuate same toward away from the cutter disc, a companion threaded element within the housing and coacting with the screw to enable a precision adjustment of the space relation of the plate and the cutter disc.

12. In a thread trimmer including a powered rotary cutter and a suction device, a combined suction nozzle and cutter head including a shear plate structure adjacent the rotary cutter, a thread-receiving port in the shear plate arranged for directing the thread into the rotary cutter, a slide by which the shear plate is carried, a flxer'i guide coacting with the slide, and screw thread means for actuating the shear plate toward and from therotary cutter.

13. In a thread trimmer including a powered rotary cutter and a suction device, a combined suction nozzle and cutter head including a pair of shear plate elements adjacent opposite peripheral portions of the rotary cutter, a threadue ceiving and thread-erecting port in each of the shear plate sections, arranged for directing the thread under the influence of said suction device into the rotary cutter, a horizontally movable slide individual to and by which each of the shear plate sections is carried, a fixed guide coacting with the slide, independent screw thread means for separately actuating the shear plate sections toward and from the severance region of the rotary cutter, the said ports in the shear piate sections being located in zones substantially di ametrically opposite each other in respect to the cutter.

14. In a thread trimmer, a supporting frame, a motor, and a suction blower driven by the motor and carried by the supporting structure, a suction nozzle in communication with the inlet of the blower, a rotary cutter element in the nozzle operatively connected to the motor, a shear plate structure forming a closure for a frontal portion of the nozzle in the immediate region of the rotary cutter element, and provided with spaced thread-receiving and -positioning ports which constitute suction inlets to said nozzle, and independent adjusting means permitting a variation in space relation between the ported regions of the shear plate structure, each of said means including a slide to which one ported portion of the shear plate structure is attached, and a second slide to which a remote portion of such structure is attached, each of said slides being movable parallel to the axis of the cutter element, a guide coacting with each of said slides to restrain same to a linear movement, and an adjustment screw coacting with each slide and accessible for adjusting movement, externally of the suction nozzle.

15. In a thread trimmer, a housing, a motor in the housing, a suction blower in the housing driven by the motor, a suction nozzle on the housing, a rotary cutter element in the nozzle operatively connected 'to the motor, a shear plate elementforming a closure for at least a portion of the nozzle in the region of the rotary cutter element, a slide to which the shear plate element is attached, the slide being movable parallel to the axis of the cutter element, a guide coacting with the slide to restrain same to a linear movement, and an adjustment screw coacting with the slide for movement of same toward and away from the cutter element.

16. The combination and arrangement of elements as recited by claim 15, but further characterized by the provision of a pair of shear plate sections or elements located on diametrally opposite regions of the cutter disc, said shear plate sections being provided with oppositely convergent thread receiving ports forming suction openings into the nozzle, together with a pair of guides, slides and adjustment screws serving the respective shear plate elements whereby to enable independent adjustment thereof toward and from the cutter element.

17. The combination in a rotary thread trimmer of suction type, of a combined suction nozzle and cutter head to which the Work is presented for thread trimming action, the nozzle including a shear plate, a rotary cutter within the nozzle and adjacent the shear plate, the shear plate formed to provide a, series of thread-receiving suction openings arranged in a linear row and in lateral adjacence to each other, the openings being characterized by convergent sides, and the plate formed to include a companion series of openings juxtaposed to those of the first said series, and characterized by sides which converge in the direction of movement of threads toward the periphery of the cutter disc.

18. In a powered, rotary, suction-type thread trimmer, a casing, a motor, a suction blower and a rotary cutter disc, a nozzle forming an extension of the casing and having an end closure, the cutter disc being located within the nozzle and adjacent said closure, the closure being characterized by two horizontally aligned, thread-receiving suction and shear ports in diametrally opposite zones of the rotary cutter disc, the closure being formed to include two separate sections, each defining at least a part of the opposite suction ports, and means enabling independent adjustment of said sections toward and from the cutter disc.

19. In a thread trimmer of powered, rotary, suction type, a casing, amotor in said casing, a suction blower in the casing powered by the motor, a suction head or nozzle constituting an extension of the casing, a rotary cutter disc located within the nozzle, a sectional shear plate structure forming a closure for the nozzle and located close to the cutter disc, the shear plate structure consisting of four sections, said sections including a first pair provided with adjacent, oppositely tapered suction openings of toothed character, a third section of the shear plate structure constituting an imperforate intermediate closure over the central area of the cutter disc, and a fourth said section overlying a margin of the cutter disc and provided with a Y shape threadreceiving port converging toward the cutter disc; the nozzle being constituted of an upper and lower stationary boss, a guide element at each side of the bosses, a slide element bearing a mortise relation to each of said guide elements, the first pair of said shear plate sections being secured to one of said slide elements, and the said fourth section being secured to the other said slide element, a lateral extension on each said slide element, a compression spring coacting with each said projection, and a precision adjustment screw coacting with each of said extensions, whereby to enable an independent adjusting movement of each slide and the shear plate sections associated therewith, in a direction along the axis of the cutter disc.

C. BRUCE SCRANTON. CARL T. BREWER.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,666,969 James Apr. 24, 1928 1,669,481 Meylach May 15, 1928 1,764,202 Dreyfus June 17, 1930 1,812,645 Bergson June 30, 1931 1,835,308 Kelleher Dec. 8, 1931 2,226,130 Kinsella Dec. 24, 1940 2,372,788 Lombardo 1 Apr, 3, 1945 2,465,058 Burkett Mar. 22, 1949

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