US3563281A

US3563281A - Apparatus and method for operating a weaving machine

Info

Publication number: US3563281A
Application number: US804813A
Authority: US
Inventors: Erwin Pfarrwaller
Original assignee: Sulzer AG
Current assignee: Sulzer AG
Priority date: 1968-03-08
Filing date: 1969-03-06
Publication date: 1971-02-16
Anticipated expiration: 1988-02-16
Also published as: AT290426B; CH469839A; DE1911456A1; FR2003491A1

Abstract

The actuation of various components such as a weft thread brake or weft thread stop motion are positively controlled in response to the arrival of the weft insertion element at a predetermined point in the catcher. The arrival of the weft insertion element can be determined mechanically, photoelectrically or magnetically and such determination is used to actuate the other machine components in dependence thereon.

Description

United States Patent Inventor Erwin Pfarrwaller Winterthur, Switzerland Appl. No. 804,813

Filed Mar. 6, 1969 Patented Feb. 16, 1971 Assignee Sulzer Brothers, Ltd.

Winterthur, Switzerland Priority Mar. 8, 1968 Switzerland 3522/68 APPARATUS AND METHOD FOR OPERATING A WEAVING MACHINE 1 Claim, 13 Drawing Figs.

11.8. CI 139/336, 139/3 42, 132/370 Int. Cl. ..1)03 d 51/113, D03d 51/34 Field of Search 139/ 1 22 56] References Cited UNITED STATES PATENTS 3,1 24, l 66 3/1964 Pfarrwaller 139/341 3,373,773 3/] 968 Balentine et al. 139/341 FORElGN PATENTS [,5 1 8,598 2/l968 France 139/125 399,354 9/1965 Switzerland 139/126 Primary Examiner-Henry S. Jaudon Attorney-Kenyon and Kenyon, Reilly, Carr & Chaplin ABSTRACT: The actuation of various components such as a weft thread brake or weft thread stop motion are positively controlled in response to the arrival of the weft insertion element at a predetermined point in the catcher. The arrival of the weft insertion element can be determined mechanically, photoelectrically or magnetically and such determination is 7 used to actuate the other machine components in dependence thereon.

PATENTEHFEBIBIHYI 3.563281 I saw 2 BF 6 In wen/0r PATENTEDFEmsmn SHEET 3 OF 6 80 53 ooooc/o oo APPARATUS AND METHOD FOR OPERATING A WEAVING MACHINE This invention relates to apparatus and method for operating a weaving machine, and more particularly, to looms having a weft insertion element to which the weft thread remains connected at the end of a pick until the weft insertion element comes to a halt.

Heretofore, weaving machines which have used weft inserting elements to which a weft thread remains connected until the element comes to a halt after passing through a shed, have had various components, particularly those concerned in picking operations, such as a weft stop motion and a weft thread brake, which have been caused to operate at a particular instant of time during the machine cycle. For instance, the weft stop motion which is usually on the weft insertion side has always come into the operative position when the main shaft of the machine is in a particular angular position. Similarly, the weft thread brake has always been made to operate when the main shaft is in a particular angular position (which is usually different from the other angular position for the weft stop motion). As has been known, these functions always occur at the same time, or at the same angular position of the main shaft, in each cycle of operation.

However, in various weaving machine, such as machines in which a gripper shuttle is shot from the weft insertion side and then travels freely and unpowered and automatic looms in which the shuttle takes the weft pirn through the shed, the weft insertion element, e.g. a shuttle, does not always arrive at the opposite catching side at exactly the same time, i.e. at exactly the same main shaft angle, in each cycle. With some picks, viz. picks which end relatively late, it is inadvisable for some components of the weaving machine, such as the weft stop motion and the weft thread brake on the weft insertion side, to move into the operative position relatively early, merely because there may be some picks which have ended or which may have ended earlier, i.e. at an earlier angular position of the main shaft.

Accordingly, it is an object of the invention to actuate various components of a weaving machine in dependence on the arrival of a weft insertion element at the catching side of the machine.

It is another object of the invention to sense the arrival of a weft insertion element at a predetermined point at the catching side of the machine in a relatively simple manner.

It is another object of the invention to automatically sense the arrival of a weft insertion element on the catching side of a weaving machine and to automatically actuate other machine components in response to the sensing of the weft insertion element.

It is another object of the invention to increase the speed of a weaving machine.

Briefly, the invention provides an apparatus and a method of operating various components of a weaving machine in dependence upon the arrival of a weft insertion element at the catching side of the weaving machine. The weaving machine is generally one which utilizes a picking motion assembly for propelling a weft insertion element through a shed of warp threads, a catching motion assembly for receiving and halting the weft insertion element, and a weft insertion element in which a weft thread remains connected until the element comes to a halt.

The apparatus of the invention constitutes a control system which includes a sensing means located outside the shed on the catching side of the weaving machine. The sensing means is adapted to detect the arrival of the weft insertion element at a predetermined point on the catching side of the machine and to produce a signal indicating the sensed arrival of the weft insertion element. Further, the sensing means is operably connected to at least one other component of the weaving machine, such as a weft thread stop motion or a weft thread brake, for delivering the produced signal to that component for actuation of that component. To this end, the control system can include an electronic control unit which is disposed to receive the signal from the sensing means and to emit a control signal in dependence upon the received signal to the controlled component of the weaving machine.

The method of operating a weaving machine consists in controlling at least one other element of the weaving machine in dependence upon the arrival of the weft insertion element at a predetermined location on the catching side of the machine.

By means of the invention, the time at which a component, such as the weft thread brake or a weft stop motion on the weft insertion side, starts to operate can be delayed in the case of picks which terminate later than is usual. For instance, the weft thread brake can be brought to the braking position just before the weft insertion element actually stops. The weft stop motion can continue operating until. immediately before the weft insertion element stops and thus can detect weft thread breakage which occur very near the end of the insertion element movement. The controlled components can also come into operation correspondingly sooner for picks which end sooner. A particular feature of delaying the operation of such components, such as the weft thread brake and the weft stop motion, is that the efficiency of the weaving machine can be increased, especially in cases in which the weft material is a relatively heavy yarn, such as wool or jute or a synthetic ribbonlike structure (strips of film or ribbons or the like). In such cases, the relatively heavy weft material causes the free-flying shuttle to reach the catching side relatively later, and if in such cases the weft thread brake is applied relatively early, as in the known machines, picking, which is slowed in any event, is slowed still further so that the individual cycle takes longer. If, therefore weft thread braking occurs only immediately before the end of picking, the time required for a single pick is reduced so that the machine speed and therefore performance can be increased.

It is clearly advantageous for the weft stop motion to continue operating until just before the end of each individual pick so as to detect any thread breakage or mispicks occurring near the end of the pick.

The invention also makes it possilble to alter the weaving width or the speed of operation of the machine (number of picks per minute) without having to alter the time of operation of the weft stop motion or of the weft thread brake by means of complicated adjustments such as by cam changing. These components are controlled in dependence upon the time of arrival of the weft insertion element on the catching side and so the time at which these other components operate is adapted automatically to the weaving width or machine speed.

These and other objects and advantages of the invention will become more apparent from the following detailed description and appended claims taken in conjunction with the accompanying drawings in which:

F IG. 1 illustrates a diagrammatic view from the cloth side of a gripper shuttle weaving machine embodying the invention;

FIG. 2 illustrates a diagrammatic view of some of the machine components of importance for the invention;

FIG. 3 illustrates a side view of a mechanical sensing means according to the invention;

FIG. 4 illustrates a side view of a modified mechanical sensing means according to the invention;

FIG. 5 illustrates a side view of a photoelectric sensing means according to the invention;

FIG. 6 illustrates a side view of a modified photoelectric sensing means according to the invention;

FlG. 7 illustrates a side view of a magnetic sensing means according to the invention;

FIG. 8 illustrates a side view of the magnetic sensing means of FIG. 7 with a weft insertion element in sensed position;

FlG. 9 illustrates a side view of a modified magnetic sensing means according to the invention;

F i6. 10 illustrates an end view of the sensing means of FlG.

FIG. 11 illustrates a top view of the sensing means of FlG. 9

. with a weft insertion element in a sens-ed phantom position;

FIG. 13 illustrates a further modified magnetic sensing means according to the invention.

Referring to FIG. I, a weaving machine includes a pair of upright side frame members 1, 2 which support in a known manner a cloth beam 3, a main shaft 5, which is driven by a suitable driving means 6, 7, a warp beam 21, a reed 8 and heald shafts 9 as well as a picking motion 13 and a catching motion 15 for a shuttle 12. The weaving machine also defines a shed 80 of a width 60. In addition, a sensing means 22 of a control system is disposed in the catching motion 15 along with a brake 23 comprising two brake shoes. During operation, a weft thread 10 is drawn off a bobbin 11 which is positioned outside the shed and after being inserted into the shuttle 12, for example, a gripper shuttle, is picked by the shuttle 12 into the shed by being pulled from the picking or weft insertion side 25 at station 13 to the catching side 55 at station 15.

Referring to FIG. 2, the weaving machinefurther includes other components such as, a weft thread brake 24 disposed on the weft picking side 25, a weft stop motion 26, and a weft thread draw-back device 28 which reciprocates vertically in the direction indicated by the arrow 27.

The weft thread brake 24 which serves to brake the delivery of thread upon completion of a pick comprises a bottom shoe 33 and a top shoe 32, the latter being biased by an adjustable spring 31 towards the former. The bottom shoe 33 is secured to an armature 34 of a solenoid 35 for reciprocating movement towards and away from the top shoe 32 upon actuation of the armature 34. The armature 34 is biased by a spring 36 which tends to maintain the armature 34 in its inoperative position, as shown. The solenoid 35 is in a circuit 37 connected toan electronic control and amplifier unit 38 which in turn is connected by lines 57 to a power source 58 for the whole control system. v

The weft stop motion 26 which serves to monitor the weft thread during picking comprises a feeler 42 which is pivotally mounted around a pivot 41 in the weaving machine and which has a free arm connected to a tension spring 44 which tends to pivot the feeler 42 clockwise as viewed in FIG. 2. The arm 45 also forms the armature of a coil 46 which is in a circuit 47 also connected to the amplifier and control unit 38.

The weft thread draw-back device 28 which serves to retract a picked weft thread just before release of the weft thread from the shuttle 12 on the catching side is mounted for reciprocating vertical motion to create a thread reserve for the picking operation.

Also shown in FIG. 2 are a number of shuttle-guiding teeth 51 which extend across the weaving shed width and through whose apertures 52 the shuttle 12 passes during picking. The FIG. shows warp threads 53 in the top shed position and warp threads 54 in the bottom shed position. In operation, after picking, the teeth 51 are moved out of the shed for beating up and shed changing; then, the teeth 51 again move up into the shed through the bottom warps 54, whereafter the next pick can be made.

The sensing means 22 is disposed ahead of the brake shoes 23 as considered in the picking direction. For the sake of simplicity, other items which are located at the edges of the shed and which cooperate with the weft thread have been omitted. In actual fact, the sensing means 22 and station 15 of the catching motion 55 are at some distance from the shed 86, i.e. the cloth width 60. The sensing means 22 includes a sensing head which is in a primary control circuit 56 connected to the unit 38 so as to activate the unit 38 upon arrival of the shuttle 12. A shuttle return slider 59 is also mounted on the catching side 55 which, when the shuttle 12 stops immediately after completion of the pick, moves the shuttle 12 back from the position in which it has stopped into another position which is further to the left and which is an unchanging thread release position.

The main shaft 5 which is shown in a diagrammatic perspective view has an annular disc 61 mounted thereon which includes two permanent magnets 62, 6.3. In addition, a switch 64 such as a reed switch which will be described in greater detail hereinafter is mounted adjacent the disc 61 so as to be switched on and off by the two magnets 62, 63. These elements 61 to 64 thus form a device for preparing the

control system

22, 38; 35, 46 for operation during a particular portion of each complete revolution of the main shaft 5. As shown, magnet 62 is offset from the 0 position of the main shaft 5 by an angle A, while the other magnet 63 is offset from the main shaft 5 by an angle A The operating range of the

control system

22, 38 35, 46 is thus the range covered by the distance between the angles A and A,.

Referring to FIG. 3, the head of the sensing means 22 comprises a feeler 66 which is pivotally mounted about a pivot 65 and which, upon arrival of the shuttle 12 at the catching side 55, pivots from the chain-dotted position 660 to a solid-line bottom and operative position 6612. The feeler 66 has a free arm 67 which cooperates with a switch 68 which moves a contact 69 in the circuit 56 from a chain-dotted position 69a into a solid-line bottom and closed position, to close the primary control circuit 56 when the shuttle 12 has reached the catching side 55 and has been braked in the motion 15. It is assumed that the electronic control unit 38 is prepared for operation as the magnet 62 passes by switch 64.

In operation, referring to FIGS. 2 and 3, approximately at or shortly before the beginning of picking, the magnet 62 passes the switch 64 to close the switch temporarily so that a signal is produced by the unit 38 which acts to deenergize the solenoids 35, 46 of the thread brake 24 and the weft thread stop motion 26 respectively. The spring 36 therefore releases the brake 24 by moving the bottom shoe 33 downwardly and the spring 44 moves the feeler 42 of the stop motion 26 from the chain-line inoperative position 42a shown in FIG. 2 into the solid-line sensing position 42. At about the start of picking, the drawback device 28 moves from the top position 28 into the chain-lineinoperative bottom position 28a. During the pick which then follows, the shuttle l2 and the weft thread 10 pulled thereby move to the right as viewed in FIG. 2 through the shed formed by the

warps

53, 54 and through the path 107 defined between the brake shoes 33.

When the nose 12a of the shuttle passes the feeler 66 of the sensing head 22 a signal is transmitted by the switch 69 along the leads 56 to the control unit 38 which then energizes the two solenoids 35, 46 so that the thread brake 24 returns to the on position (not shown) and the stop motion feeler 42 moves into the chain-line inoperative position 42a. Throughout picking, therefore, the stop motion 26 supervises the weft thread 10, since the gentle pull of the spring 44 keeps the feeler 42 in continuous engagement with the thread 10. The brake 24 goes right on" only right at the end of picking; similarly, the feeler 42 disengages from the weft thread 10 only right at the end of picking. The brake shoes 23 in the catching motion 55 then stop the shuttle 12 completely (stop position), whereafter the slider 59 moves the shuttle 12 to the left as viewed in FIG. 2 into precisely located thread release position. During this leftwards movement the draw-back device 28 moves upwards from the inoperative position 28a to draw back the slackened thread 10.

Should the weft thread 10 break or separate from the shuttle 12 (known as a mispick) during picking, the weft thread loses its tension and the spring 44 pivots the feeler 42 into the chain-dotted position 42b causing the arm 45 to bridge two contacts 82 of a stop circuit 81. The stop circuit 81 therefore closes so that the stop motion (not shown) operates as is known and stops the weaving machine, whereafter the loom minder can clear the weft thread breakage.

After the signal initiated by the shuttle 12 has been delivered by the head 22, the magnet 63 passes the switch 64 to close the switch 64. The control unit 38 therefore produces another signal as is known which is used to check whether the signal just referred to and produced by the head 22 and shuttle 12 has already been given. The control unit 38 is so devised that if a signal has been given, as is the case for normal operation, the machine is unaffected and therefore continues to operate. If, however, the head 22 fails to deliver a signal, this usually means that the shuttle 12 has not reached the catching side 55. In this case, i.e. while the magnet 63 is acting via the switch 64 to produce a signal in the unit 38, the unit stops the machine by way of an electrical connection 84 which extends from the unit 38 to the stop motion control circuit 81. It is therefore unnecessary to provide a special sensing pin which checks for arrival of the shuttle 12 in the mechanism 15, as the function formerly provided by such a pin is taken over by the head 22 and the magnetically operated switch 64.

In an alternative form, the control unit 38 is so devised that when the head 22 delivers a signal, the thread brake solenoid 35 is deenergized simultaneously whereas a brief time elapses before the stop motion solenoid 46 is deenergized, thus ensuring that, as may sometimes be desirable, the feeler 42 is pressed against the weft thread shortly after the start of picking.

In yet another alternative form, the control unit is so devised that a predetermined brief time interval elapses between the transmission of the sensing head signal and the transmission by the control unit 38 of the two signals for the solenoids 35 46. It may be convenient for these two signals to be delayed to ensure that the brake 24 is not applied immediately upon the shuttle head 12a reaching the feeler 66 but is applied only when most of the shuttle 12 is already between the brake shoes 23 and has almost stopped. Conveniently too, the solenoid 46 can be energized with a delay such that the feeler 42 continues to press against the thread 10 until the shuttle 12 has reached the position just referred to between the brake shoes 23.

Referring to FIG. 4, the sensing head of the sensing means 22 can alternatively have two electrical contacts 85 which are connected in the control circuit 56 and which are biased upwards as viewed by springs 86. In operation, when the shuttle 12 has reached the catching side 55 and has entered the catcher or is moving between the two brake shoes 23, the contacts 85 are pressed down from the chain-dotted position 85a into the solid-line positions and electrically interconnected by the shuttle 12, which in this case must be made of an electrically conductive substance. Thus, upon completion of the circuit, the operation of the sensing means and control system functions as described above.

Referring to FIG. 5, the sensing head of the sensing means 22 can also be a photoelectric barrier 91 comprising a light source 92 whose light is converted into a parallel beam 94 by a lens 93. After passing through another lens 95 the light impinges on a photocell 96 connected in the control circuit 56. When the shuttle 12 reaches the catching side 55 or catcher 15, i.e. when the beam 94 is interrupted, a signal corresponding to the sensing head signals previously described is produced in the electronic control unit 38. Consequently, interruption of the beam 94 initiates the signals, hereinbefore described with references to FIG. 2, for the solenoids 35, 46 and triggers off other events as previously explained.

Referring to FIG. 6, a different form of photoelectric barrier 91 can alternatively be used. In the absence of a shuttle, the beam 94 is reflected back on itself from a reflecting surface 99 and is reflected by a semireflecting mirror 97 to a photocell 96 connected in the control circuit 56. When the shuttle has entered the catcher 1S, reflection is either suppressed or greatly reduced since, as is necessary for this example, the shuttle is made of a material, such as plastics, which reflects little, if at all. Consequently, when the shuttle 12 is present no light reaches the photocell 96. When the shuttle 12 has reached the catching side, i.e. when no light beam reaches the cell 96, the signals previously referred to for the solenoids 35, 46, are delivered by the unit 38 and the other events are initiated.

Referring to FIGS. 7 and 8, the sensing head of the sensing means 22 can also be of a magnetic type. In this case the sensing head has a permanent magnet 101 formed with two pole pairs 102, 103 and 104, 105 disposed perpendicularly of each other. In addition, a field plate 106 is disposed between the first pair of

poles

102, 103 within a magnetic field 108 created by these poles and is connected in the control circuit 56. This field plate 106 is, for example, a semiconductor such as germanium. The second pair of poles 104, is disposed on the path 107 of the shuttle 12 entering the catcher 15 to create a magnetic field 109 which passes through the shuttle path 107.

In operation, when no shuttle is present above the sensing head, as shown in FIG. 7, a relatively strong magnetic field 108 is formed between the two

poles

102, 103 and a relatively weak magnetic field 109 is formed between the

poles

104, 105; the

poles

104, 105 being further apart from one another than are the

poles

102, 103. When the shuttle 12 passes over the sensing head 22 on the catching side 55 as viewed in H0. 8 (in this example the shuttle is made preferably of steel and in any case of magnetically conductive substance), the magnetic reluctance between the

poles

104 and 105 is reduced considerably, so that a relatively weak field 106a exists between the

poles

102, 103 and a relatively strong field 1090 which passes through the shuttle 12 exists between the

poles

104, 105. Consequently, the magnetic field passing through the plate 106 is of low intensity. In order to utilize this reduction in the magnetic field, the field plate 106 is constructed so that its electrical resistance alters in dependence upon the strength of the external magnetic field. The resulting relatively weak field 108a then initiates a signal in the unit 38 to trigger the signals hereinbefore described for the solenoids 35, 46 and the other events.

Referring to FIGS. 9 to 12, a permanent magnet 111 can alternatively be disposed on the shuttle path 107 on the catching side 55 or in the catcher l5, and a reed switch 64a responsive to a strong external magnetic field can be disposed very near the magnet 111 to cooperate therewith. In such a case, for example, the magnet 111 has a pair of

poles

113, 114 which are spaced apart below the shuttle path 107 to create a magnetic field 115 which intercepts the shuttle path 107. Also, the switch 640 is positioned astride the: magnet 111 below the plane of the magnetic field 115 and parallel to the magnet 111 so as to intercept the magnetic field 116 of the magnet 111. The operation of the switch 64a now to be described also applies to the switch 64 in FIG. 2.

In this embodiment, the shuttle 12 is assumed to be made of a magnetically conductibe substance, such as steel. When the shuttle 12 has reached the catching side 55 or catcher 15, as has been assumed in FIGS. 9 to 11, a relatively strong mag netic field 115 is produced between the two

poles

113, 114 of the magnet 111, whereas a relatively weak field 116 passes through the switch 64a, with the result that the two resilient contacts 117 of the switch 640 open.

If, on the other hand, and as assumed in FIG. 12, there is no shuttle above the magnet 111, i.e. above

poles

113, 114, the strength of the magnetic field 1150 between the

poles

113, 114 becomes relatively weak, whereas the strength of the field 116a moving above the switch 64a is relatively large. Consequently, the contacts 117 move into the closed position as shown in FIG. 12. Thus, when the shuttle has reached the catching side, i.e. when the contacts 117 open as shown in FIG. 11, a corresponding signal is given in the electronic control unit 38 and the other signals hereinbefore described are transmitted to the solenoids 35, 46 to trigger the other events.

Referring finally to FIG. 13, the sensing head of the sensing means 22 can alternatively comprise an induction coil 121 having a soft iron core 122 which is connected in the control circuit 56. In use, when the shuttle 12, which, in this example, is made of steel, moves past the coil 121, the magnetic field formed by the coil 122 alters to produce a signal in the control circuit 56 which is transmitted to the control unit 30, so that the other signals hereinbefore described are transmitted to the solenoids 35, 46 and the other events are initiated.

If required, only the weft thread stop motion 26 or only the thread brake 24 can be controlled by the sensing means 22, or one or more other elements of the weaving machine can be controlled by the sensing means 22 either individually or together or in a fixed timing determined by the control unit 38. The elements thus controlled can be of the kind which can have only two positions and whEh are changed over from one position to the other by the sensing head control. If required, elements having more than two positions can be used, in which case, where applicable, the secondary control signal delivered by the control unit 38 can go to an element which prepares some other event dependent upon other operating factors or other parts of the weaving machine. The preparatory element can be in the nature of an unlocking device.

The word control is intended to denote every kind of supervision of or action on a weaving machine element which stops or starts in response to a signal from the sensing means 22 or which has a change made to some other operating parameter. What is always meant is the controlling of other elements, more particularly elements disposed on the picking side 25 and elements associated with picking, in dependence upon the instant of the time at which the weft insertion element eg the shuttle 12, reaches the catching side 55 or catching motion is. The instant of time at which the weft insertion element reaches the catching side differs from pick to pick, and so the timing of the operation of the other elements controlled by the sensing means 22 will also vary, i.e. be adapted to the times of arrival of the weft insertion element.

The sensing means 22 can be located either in the catching motion 15 or, as considered in the picking direction, im-

mediately ahead of the catching motion. The weft insertion elements can be, for example, free-flying gripper shuttles or weaving shuttles which carry a pirn with them through the shed, and particularly elements of the kind which do not always automatically reach the catching side at the same instant of time in the operating cycle.

Iclaim:

1. In combination with a weaving machine having a picking motion and a catching motion disposed on opposite sides of a shed for picking a weft thread insertion element through the shed and at least a weft thread stop having a movably mounted weft thread feeler for resiliently contacting a weft thread during the picking, said stop being disposed to stop the weaving machine in response to pivoting of said feeler towards a weft thread upon breakage of the weft thread during picking; a control system including a sensing means located outside the shed on the catching motion side for sensing the arrival of the weft insertion element at a predetermined point thereat and for emitting a first signal in response to the sensed arrival of the element, and second means connecting said sensing means to said weft thread stop for actuation of said stop in response to said signal to prevent pivoting of said feeler towards the weft thread.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,563 28l Dated February 16, 1971 Inventor(s) in Pfarrwaller It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Golumn 2, line 4?, insert "new" before --weaving-- Column 7, line 18, change "catching motion is" to ..catching motion 15-- Signed and sealed this 1 at day of June 1 971 (SEAL) Attest:

EDWARD M.FLE'I'CHER,J"R. WILLIAM E. SCHUYLER, JR. Attesting Officer Commissioner of Patents USCOMM-DC 60876-5 'ORM F'O-1 050 (10-69)