US2634607A - Strand testing machine - Google Patents

Description

April 14, 1953 R. H. LAWSON STRAND TESTING MACHINE 5 Sheets-Sheet 2 Filed Aug. 9, 1946 [wan/rm EZaeaZtZZZauavn April 1953 R. H. LAWSON 2,634,607

STRAND TESTING MACHINE Filed Aug. 9, 1946 5 Sheets-Sheet 3 INVENTOR. 220$e22ZZW April 14, 1953 R. H. LAWSON STRAND TESTING MACHINE 5 Sheets-Sheet 4 Filed Aug. 9, 1946 INVENTOR.

Patented Apr. 14, 1953 GFFHCE STRAND TESTING MACHINE Application August 9, 1946, Serial No. 689,559

6 Claims. (01. 73-460) This invention comprises a machine for testing textile strands in order that they may be subsequently used with assurance that they have the characteristic requirements of elongation, strength and elastic power necessary for their intended purpose.

The machine of my invention may be organized for testing strands by subjecting them either to a predetermined elongation or to a predetermined tension, and for testing strands that are either stretchable or non-stretchable. For example, in winding golf balls of rubber thread, an elongation of ten to one is often specified and it is therefore important to ascertain that all rubber thread delivered to the winding machine is capable of withstanding such elongation without breaking. If breakage occurs in the winding machine, the winding cost is increased and goods of inferior quality produced. The same problem is encountered in textile machinery where stretchable strands are to be employed in weaving and spinning. In addition to rubber thread, rubber covered thread and rayon and nylon thread are purposely or incidentally subjected to elongation, and in these instances it is Very desirable to employ strands which have been tested and proved capable of the required elongation with a comfortable margin of safety.

With these ends in view, the present invention in one aspect comprises a continuously operating machine through which the strand to be tested may be run at high speed and Without requiring any substantial amount of skill or attention on the part of the operator, and in which the strand is subjected to a definite predetermined amount of stretch by being elongated to a degree which thoroughly tests it, meanwhile continuously indicating the instantaneous tension of the strand and acting automatically to stop in case of breakage.

When organized for that purpose, the machine of my invention comprises a strand feeding head rotated at a predetermined peripheral speed in combination with means for feeding an elastic strand to the head at a rate of speed bearing a predetermined fractional ratio to the peripheral speed of the head. Preferably and as herein shown, I employ two rotary strand-feeding heads driven at different rates of linear speed. A weighted member may be employed for engaging the strand as it passes from one head to the other and indicating the instantaneous tension therein. Automatic stopping means are also provided which act upon the strand tensioned between the two heads for stopping the machine in case of breakage.

In another aspect my invention comprises a machine in which the rotation of one of the strand-feeding heads is retarded so that a controlled amount of tension is developed in the strand passing from one to the other. This result may be accomplished by gearing introduced between the two heads, in which case the strand is subjected to a controlled elongation and tension, or by a brake acting on the in-feeding head, in which case the strand is subjected to a controlled amount of tension.

Other features of the invention relate more specifically to features of the strand feeding heads. These are preferably of the capstan type disclosed in U. S. Letters Patent No. 1,847,161, March 1, 1932, Alden, and comprise a set of threaded spindles which rotate collectively with the head as well as individually, with the result that the various turns of the strand around the capstan are maintained out of engagement with each other during the pulling or advancing movement. I have found that the accuracy of operation and life of such strand feeding heads are substantially improved by providing a rotary member for supporting the outer ends of the threaded spindles thus holding them accurately against deflection from their proper axes of rotation and substantially reducing Wear on their bearings.

Going more into detail, I have found it also desirable to provide means for supporting the thread spindles against circumferential displacement. As herein shown,- such means may comprise radially projecting arms extending on both sides of each threaded spindle, being normally arranged to clear the spindle but located permanently in position to arrest and prevent any circumferential displacement, particularly such as might otherwise occur at the outer ends of' the spindles.

These and other features and advantages of the invention will be best understood and appreciated from the following description of a preferred embodiment thereof, selected for purposes of illustration and shown in the. accompanying drawings, in which:

t Fig. 1 is a View of the machine in front elevalOIl,

Fig. 2 is a view inelevation of the clamping device for the indicator as seen with its cover removed,

Fig. 3 is a sectional view on the line 3-3 of Fig. 2,

Fig. 4 is a plan view of the machine,

FEE? '5 is a sectional view on the line 55 of 1g.

head Fig. 6 is an end view of the machine showing a portion of the casing broken away,

Fig. 7 is a sectional view on the line 'I-'! of Fig. 5,

Fig. 8 is a wiring diagram of the machine,

Fig. 9 is a view in perspective of a winding head of modified construction,

Fig. 10 is a fragmentary view of the same,

Fig. 11 is an end view,

Fig. 12 is a view of the machine in front elevation modified to subject the strand to controlled tension, and

Fig. 13 is a sectional view on the line I3I3 of Fig. 12.

The machine in its illustrated embodiment comprises a rectangular base It] from which rises a front plate I I carrying the moving parts of the machine and being provided with a cover plate I2 which is removably secured to the base plate by bolts having knurled nuts I3. A drawing-in head I4 and a strand delivering head I5 project forwardly from the front plate I I at substantially the same level. These heads are identical in construction except that the head I5 is located further out from the face of the plate I I than the head It so that a strand passing from the outer ends of the spindles I6 of the head I4 will follow a straight path in reaching the inner ends of the spindles I6 of the head I5 without the necessity of a guide.

As shown in Fig. 5, each spindle It has a shaft of reduced diameter which is mounted in needle bearings I! in the head I4, and each shaft is provided with a pinion I 8 acting as one member of a planetary system including a central gear I9 which is held stationary by being pinned to a collar bolted to the front plate II. Ihe gear I 9 is provided on its rear face with a sleeve 2!! which fits into the stationary collar 25 which is bolted to the front plate II and supports the entire strand feeding head. Passing through the sleeve 20 is a central shaft 2| journaled in needle bearings 22 which are mounted in a bushing set in the front plate I I. The shaft 2] is fastened by a set screw 23 to a hub formed on the head I4 and drives the head with its six threaded spindles, the latter. being also individually rotated by the planetary gearing above described.

At its outer end the shaft 2I carries a supporting disk 24 contacting at its circumference with all of the spindles I6 and by rolling contact holding them positively against inward radial displacement, The provision of the supporting disk not only reduces wear on the spindle bearings but maintains them accurately in position and eliminates lost motion therein.

At its inner 'end the shaft 2I carries a driving pinion 2'I meshing with an idle pinion 28 rotatable with an intermediate shaft 29 journaled in the front plate and carrying also a large gear 30. The gear 30 in turn meshes with a gear 3I fast on a second intermediate shaft 32 projecting forwardly from a swing plate 33 pivotally mounted to swing about a horizontal axis provided by the shaft 2I' of the strand delivering I5. The shaft 32 projects outwardly through a segmental slot 35 described about the axis of the strand delivering head I5. The plate 33 carries also a short shaft on which is mounted a pinion 3I meshing with the pinion 3| and also with the pinion 38 upon the inner end of the' shaft 2I' of the head I5. This shaft carries also a larger pinion 39 meshing with the pinion no carried by a shaft of a. motor 4| which is supported by the rear portion of the base In as shown in Fig. 6.

The shaft 32 of the swing plate 33 is provided with a knurled nut 36 by means of which the plate may be clamped in any desired position of adjustment causing the gears of the train properly to mesh. It will be noted that the 'gear 30 is removably attached to its shaft 29, and thus the machine has provision for the convenient substitution of various sets of change gears by which the ratio of the linear speed of the two heads I4 and I5 may be varied and the strand passing between them subjected to varied amounts of stretch.

The tension of the strand passing between the two heads is measured and indicated by mechanism which will now be described. The front plate II is provided with a boss in which is journaled a short horizontal shaft 42. On the forward end of the shaft 42 is fixed a rod 43. The end of the rod is forwardly offset as shown in Fig. 4 and carries a grooved roll 44! which rides upon the strand passing between the two heads. From the outer end of the rod 43 is suspended a weight 45 and this is readily replaceable by weights graduated in accordance with the work in hand. The shaft 42 carries a hollow disk 46 having perforated radial bafiles 4? and containing a charge of mercury 48 or other heavy liquid. This disk acts to damp the oscillation of the rod 43 and prevent the disk M from dancing upon the strand. It will be understood that the charge of mercury tends to hold the disk 66 in whatever position it assumes and its retarded flow through the perforations of the bafiles 3! retards movement of the shaft 32 and its associated parts. The shaft 42 also carries a pointer 49 which, by its displacement, indicates on its segmental scale 50 the instantaneous tension in the strand. From the foregoing description it will be seen that the greater the sag made in the strand by the roll 44, the lower will be the reading of the scale and the lower will be the tension in the strand. If desired the movement of the pointer 49 may be recorded so as to provide a permanent record of each tested strand.

The shaft 42, in addition to its function in the indicating mechanism, is utilized also to operate an automatic stop. For this purpose it is provided at its end with a segment 52 whichnormally supports in elevated position a collar 53 upon the lower end of a plunger controlling an electric microswitch 54 which, as shown in Fig. 6, is secured to the top of the casing I I. The microswitch is interposed in the main line circuit to the motor as shown by the diagram of Fig. 8. Also included in this circuit is a stopping and starting switch controlled by a button 55 which projects through the upper lefthand portion of the front plate II.

In operation the strand is led through a fixed eye 56 set in the plate II and serving to guide it to the drawing-in head I4. It is passed several times about the groove of spindles I6, and then led to the delivering head I5, passed several times about the spindle I6, and from there led out of the machine. The change gears having been adjusted for the desired testing elongation, the roll M is rested upon the strand as running under tension between the two heads, and the machine set in action. Thereupon the strand is rapidly and continuously fed through the machine, subjected temporarily to the desired amount of elongation, and delivered after having been thus tested. Meanwhile the pointer 49 indicates the instantaneous amount of tension resulting from the elongation of the strand. In case of breakage the weighted rod 43, now unsupported, immediately rocks the shaft 52 carrying the segment 52 beyond the drop-off point. The switch plunger is thereupon permitted to move downwardly and the circuit to the motor is broken.

In Figs. 9-11 is illustrated a head of somewhat modified construction which may be substituted for either of the heads Hi and I5 above described. The principal difference is that in these heads the threaded spindles are afforded circumferential as well as radial support. To that end the head 60 is recessed in its outer face to receive a shouldered stud 6! having at its outer end a seriesof radial projections 62 arranged to fit into the spaces between the threaded spindles 63 and form a series of individual guide pockets for each spindle serving positively to prevent displacement of the inner end or intermediate portion of the spindle. The stud BI is secured to the head 60 by any suitable means such as axial screws, one of which is shown in Fig. 10. The stud 6| is bored axially to receive the center shaft 64, and upon its outer end this shaft carries a disk 65 which engages the spindles 63 near their outer ends and supplies radial support to them.

The spindles 63 as well as the spindles l6 and I6 are shown herein as carrying pinions which have a 1 to 2 ratio with respect to the large stationary gear 19. Accordingly, each spindle makes two individual rotations and is rotated once in its movement with the head for each complete revolution of the head. In other words, each spindle makes three complete rotations for one rotation of the head. The result is that the turns of the strand wound about the group of spindles are kept well separated while the machine is operating. This constructional feature has been found to be particularly advantageous and effective in guarding the strands against crossing or interference.

The machine has been heretofore described as it is organized for subjecting an elastic strand to a predetermined amount of elongation and when so operating it will be clear that the speed of rotation of the in-feeding head i4 is retarded and held back with respect to the speed of rotation of the delivering head l5 by the gearing which is interposed between these two heads.

In Figs. 12 and 13 is shown the machine as organized for subjecting the strand to a controlled amount of tension. When so organized, the delivering head I5 with its threaded spindles l6 and center spindle 2| are driven directly by the motor ii through the gearing already described. The in-feeding head, however, is not driven but is under the control of a band brake. In the illustrated machine, the front plate l i is provided with a projecting circular bos 19 in which is mounted a stationary bushing H to which is attached the stationary central gear '12 of the planetary system. A spindle i3 is journaled in the bushing ll and in the boss l as shown in Fig. 13, and to this spindle is pinned the head 14. In the head is mounted a group of threaded spindle 15, each of which carries a small gear l6 meshing with the central gear 72. At its outer end the spindle 13 carries a support disk ll which makes rotary contact with the spindle l at their outer ends.

The head 74 is enclosed within a stationary segmental shield '58. Within the shield is located a band brake 19 which is V-shaped in cross section and fits into a circumferential groove of the same shape in the head 14. The brake is conn'ected at one end to a screw 80 projecting from the front plate II and at the other through a flexible cable 81 to the sha'ft '42 of the indicator. The shaft 42 carriesa'n arm 43 provided with a roller 44 having a weight '45 and arranged to run on the strand as it passes from one head to the other. The shaft 42 also carries a pointer which cooperates with the segmental scale 50 to indicate the'instantaneous tension in the strand.

It will be seen that themechanism above described operates to increase the drag of the brake as the tension in the strand decreases with the result that the tension of the strand is thereby increased. On the other hand, as the tension in the strand increases the arm 43 is lifted and the drag of the brake reduced, thereby reducin the tension in the strand. The brake and the weight may be adjusted so that a balanced operating condition is secured in which the strand is subjected to a substantially uniform tension in passing from one head to the other. If the strand is elastic the elongation may be variable, but whether or not the strand is elastic it is subjected to substantially uniform tension.

Having thus disclosed my invention and described in detail several illustrative embodiments thereof, I claim as new and desire to secure by Letters Patent:

1. A strand testing machine comprising a rotary strand-feeding head, a motor connected to the head for driving it at a uniform rate of speed, a second strand-feeding head spaced from the firstmentioned head, a train of gears interposed between the two heads for driving the second strandfeeding head at a slower rate of speed than the first-mentioned head, and a swing plate carrying one gear of the train whereby substitution may be made for adjusting the relative speeds of the two heads to vary the tension of a strand passing from one to the other.

2. A strand testing machine comprising a 1'0- tary head including a plurality of threaded strand-feeding spindles carried by the head and planetary gearing connecting said spindles, a second strand-feeding head similarly equipped with threaded spindles, means for driving the heads at different linear speeds to tension a strand passing from one head to the other, and means continuously indicating the tension of a strand passing from one set of spindles to the other.

3. A strand testing machine having a pair of rotary feeding devices geared to advance an elastic strand at diiferent linear rates of speed, a motor for driving said devices, a movable detector mounted to ride upon the strand as it passes from one feeding device to the other, a switch controlling said motor and a tension indicator, both the switch and the indicator being governed by said detector.

4. In a strand testing machine having a pair of spaced strand feeding heads located at substantially the same level and geared to rotate at different speeds, indicator mechanism comprising a movable arm carrying a roll arranged to ride on the strand in passing from one head to the other, and a hollow member having perforated bafiies therein and a partial filling of liquid and bein connected to said arm and turned therewith.

5. A strand testing machine comprising a frame carrying a pair of spaced strand-feeding heads, a motor connected to one of said heads, a swing plate mounted for movement about the axis of one head, and a gear train connecting said heads for rotating them positively at different speeds including gears mounted on said swing plate.

References Cited in the file of this patent UNITED STATES PATENTS Name Date Serrell 1 May 5, 1885 Number Number 772,090 1,742,953 1,786,917

Number 8 Name Date Duquett 11 Oct. 11, 1904 Gahlert et a1 Jan. 7, 1930 Oehmichen Dec. 30, 1930 Roller May 12, 1931 Alden Mar. 1, 1932 Cornet Mar. 29, 1932 Murphy June 5, 1934 Bouhuys Sept. 7, 1937 Jordan Dec. 24, 1940 Heinz Nov. 13, 1945 Henry July 22, 1947 Symmes Feb. 24, 1948 FOREIGN PATENTS Country Date Great Britain Nov. 6, 1863 Germany May 30, 1939 France Mar. 18, 1935

Images