US2637051A - Feeding mechanism for nipple threading machines and the like - Google Patents

Description

y 5, 1953 G. B. MARSDEN 2,637,051

FEEDING MECHANISM FOR NIPPLE THREADING MACHINES AND THE LIKE 6 Sheets$heet 1 Filed May 27, 1949 May 5, 1953 cs. B. MARSDEN 2,637,051 FEEDING MECHANISM FOR NIPPLE THREADING MACHINES AND THE LIKE Filed May 27, 1949 6 Sheets-Sheet 2 Maw y 5, 1953 G. B. MARSDEN FEEDING MECHANISM FOR NIPPLE THREADING MACHINES AND THE LIKE s SheetsSheet 5 Filed May 27, 1949 May 5, 1953 G; a. MARSDEN FEEDING MECHANISM FOR NIPPLE THREADING MACHINES AND THE LIKE 6 Sheets-Sheet 4 Filed May 27, 3.949

G. B. MARSDEN FEEDING MECHANISM FOR NIPPLE THREADING May 5, 1953 MACHINES AND THE LIKE Filed May 27, 1949 6 Sheets-Sheet 5 y 1953 G. B. MARSDEN FEEDING MECHANISM FOR NIPPLE THREADING MACHINES AND THE LIKE 6 Sheets-Sheet 6 Filed May 27, 1949 "vzm an in horizontal alignment to the position of Figure 2 in which the chucks are parallel to each other and are aligned respectively with the chasers II.

The internal construction of one of the chucks is illustrated in Figure 5. From this figure it will be seen that the chuck comprises a main body |B having a conically tapered cavity in its outer end to receive a series of gripping jaws IS. The jaws are connected to a tube 2| which extends out of the chuck body and through which the jaws may be pulled into the body so that they will be cammed inward by the tapered recess to grip a nipple or other work piece. The tube has an internal diameter slightly in excess of the maximum diameter of a work piece to be handled by the machine so that the work pieces can pass straight through the chucks from one end to the other thereof.

The two carriages l5 are connected by a bracket 22 which is connected through a spring 23 to the piston of a fluid motor or air cylinder 24. When air is supplied to the rear end of the cylinder 24, the piston will move the carriages simultaneously toward the chasers to feed the nipples into the chasers, and when the air is supplied to the forward end of the cylinder 24, the carriages will be retracted. To turn the chucks on the carriages during movement thereof, a cam plate 25 is mounted on the bed Hi and may be adjusted longitudinally by screws 26. The cam plate is formed with a pair of similar cam tracks 21 extending generally longitudinally thereof and which receive cam rollers 28 formed on levers 29 which are rotatably mounted on the carriages. The cam tracks 2'! are so shaped as illustrated that when the carriages are retracted to their feeding position as shown in Figure l the levers 29 are substantially in alignment and when the carriages are advanced to their cutting position the levers will be rocked, as shown in Figure 2. Each of the levers is formed with a gear segment meshing with a similar gear segment 3| carried by the adjacent chuck so that during movement of the carriages the chucks will be turned through 90. By proper adjustment of the cam plate 25 alignment of the chucks in the feeding position can be assured and proper turning thereof to the cutting position can also be obtained accurately.

During turning movement of the chucks from the feeding to the cutting position the tubes 2| in the chucks are pulled away from the chucks to cause the jaws to grip a work piece. For this purpose each of the carriages carries a pair of cam members 32 pivoted at 33 on the carriages, there being an upper and lower cam member on each carriage, as best seen in Figures 3 and 4. The cam members 32 are formed with cam slots 34 which are curved about th pivotal centers of the respective chucks throughout approximately the first 30 of their lengths from the pivoted ends of the cam members. The remaining portions of the slots toward the free ends of the cam members are curved on an increasing radius so that during the final 60 the cam slots lie beyond a circle which is a continuation of the initial part of the cam tracks. The cam tracks receive rollers 35 which are carried by the tubes 2| as best seen in Figure 5 so that as the chucks turn from the position of Figure 1 to the position of Figure 2 the rollers 35 will travel throughout the length of the cam slots 34. During initial turning of the chucks from the position of Figure 1 tothat of Figure 2 the rollers will move through the circular portions of the tracks and will not affect the chucks. However, during the final 60 of movement the tubes 2| will be placed under tension to draw the gripping jaws into the chuck jaws so that they will be cammed into engaged position.

In order that the chucks may accommodate nipples of varying diameter, the cam members 32 are allowed to pivot about their mountings 33 so that the tubes 2| will not always be cammed to the same position as the chucks turn. The cam members are normally held in a predetermined position by heavy compression spring units 36 which are carried by the carriages and which have thrust rods 31 extending therefrom and are normally urged outward thereof by the springs. The rods 31 are connected through levers 38 to the cam members 32 and normally urge the cam members against stops 33 which determine the limit of travel of the cam members in one direction. In the event a nipple or work piece slightly over size is placed in the chuck, the cam members can move against the force of the spring units to insure a tight grip of the work piece without damage to any of the parts.

When the chucks start to turn from their loading to their cutting position as the carriages move forward, the chucks and the carriages develop a considerable amount of inertia which might damage the cam guiding mechanism and force the nipples against the threading dies with a considerable shock. It will be noted, however, that with the spring construction as shown a sub stantial part of this inertia will be absorbed by the springs so that damage to the parts is prevented and the carriages will move into the chasers at the proper speed. Thus the inertia of the parts can be utilized to assist in compressing the springs and to insure that the nipples or work pieces will be tightly gripped in the chucks.

In order further to reduce the speed of movement of the carriages as they approach the chasers, a cam 4! is connected to the carriages to move therewith and will engage a valve 42 when the carriages reach a position adjacent the chasers.

chasers at least to the point where the chasers themselves have cut a sumcient length of thread on the nipples to draw them into the chasers.

It may be noted that particularly in the threading of galvanized nipples an extremely heavy grip by the chucks is required to insure proper holding of the nipples during the thread cutting. In the construction shown two spring units 36 are employed for each of the chucks and these units may have a compression force of approximately one thousand pounds per inch and are preferably preloaded to approximately seventy-five per cent of that amount.

The levers 38 and the effective angle of the cam tracks 34 are such as to provide an overall mechanical advantage on the order of 18:1 between the chuck jaws and the springs so that a very heavy grip is provided on the nipples. At the same time a relatively small air cylinder operating on an air pressure on the order of 60 to 70 so that the unthreaded end of the first blank will be presented to the upper chaser by the upper chuck. Thus in the second and each succeeding operation the lower chaser threads one end of each blank while the upper chaser threads the other end of the blank just previously threaded by the lower chaser. Upon completion of this operation when a new blank is forced into the lower chuck it will force the completed blank from the upper chuck. Thus the only operation necessary with the mechanism of the present invention is the feeding of blanks into one of the chucks and initiation of the cycle, all other parts of operation being formed automatically by the feeding mechanism. It will be noted that the provision of an automatic feeding means to feed blanks into the lower chuck would make the entire operation fully automatic.

In handling relatively short or close nipples it is necessary to provide some means to transfer the nipples from one of the chucks to the other due to the fact that their length is not great enough to span the distance between the chucks. For this purpose a transfer mechanism of the type shown in Figures 9 and 10 may be provided and the upper or second chuck may be equipped with special jaws, as shown in Figure 5. In these jaws the outer end portions of the jaws are threaded, as shown at H, and the jaws are formed with stop shoulders 12 at the ends of the threaded portions thereof. With close nipples it is necessary to grip the nipple threads in order that there may be sufficient length of nipple projecting from the chuck for threading, and the threaded portions H of the jaws are threaded in the same manner as the nipples so that they can grip the nipple threads without damaging them. The stop shoulders 12 prevent the threaded ends of the nipples from extending too far into the chuck jaws and insure that the short nipples will be properly gripped by the chucks.

The transfer mechanism as shown in Figures 9 and 10 comprises a trough 13 pivoted on a horizontal pivot 74 adjacent the first or lower chuck. The trough 13 is moved between a horizontal position as shown in Figure 9 and a tilted position, as shown in Figure 10 by a control lever 15 which may be controlled by a suitable cam 151: on one of the carriages. The trough is of a size and length to receive a nipple and is positioned on the bed of the machine so that when the carriages are in their loading position it will be aligned with the chucks.

To prevent a nipple from falling out of the trough when it is tilted to the position of Figure 10 a pivoted stop arm 16 is carried by the trough and has a reduced tip TI to project up into the trough to engage and stop a nipple therein. The opposite end of the arm 16 carries a roller 18 slidable in a slot 19 formed in a plate 8| carried by the bed of the machine. When the trough is in its upper horizontal position, as shown in Figure 9, the lever 16 will be rocked to a position in which its upper tip end is withdrawn from the trough, while when the trough is tilted downwardly, the lever will be rocked to a position to move its tip end 1! into the trough.

Nipple blanks in the trough are adapted to be moved therefrom into the second chuck by a feeding arm 82 whose lower end normally projects into the trough and which is movable horizontally parallel to the axis of the chucks. When the chucks are in the feeding position, as shown in Figure 9, the trough is elevated and the feeding arm 82 is normally in the position shown in full lines. When a new blank is fed into the the chuck at the left, the feeding arm will move to the dotted position and will force the nipple which was in the trough into the chuck at the right. At the same time the new blank fed into the chuck at the left will force the nipple in that chuck into the trough. As the carriage is moved forward to threading position the trough will tilt down to the position of Figure 10 so that the nipple carried thereby is below the lower end of the feeding arm 82. The tip 11 of the lever 16 will prevent the nipple in the trough from falling out, and with the trough in this position the lever 82 may be moved to the left to its starting position. When the trough is again raised to the position of Figure 9, the feeding arm will be behind the nipple in the trough in a position to force it therefrom into the second chuck.

In the threading of short nipples, instead of forcing the completed nipple completely through the second chuck the completed nipple is discharged forwardly from the chuck. As the carriage is returned from the threading position the cam member 64 will release the friction gripping jaws so that when the main chuck jaws are opened by operation of their cam control mechanism, the nipple being extremely short will fall freely from the chuck. Otherwise and except for the use of the transfer mechanism with short nipples the operation is identical on both short and long nipples and is fully automatic except for the feeding of the blanks into the first chuck.

While the mechanism of the invention has been particularly described in connection with the threading of pipe nipples, it will be apparent that many of the features of the invention are applicable to threading or other machining operations of other types. It will, therefore, be understood that the invention is not limited to the exact mechanism shown nor otherwise than by the terms of the appended claims.

What is claimed is:

1. Feeding mechanism for nipple threading machines and the like having a head rotatable on a horizontal axis comprising a carriage movable horizontally toward and away from the head, a chuck pivoted on the carriage on a vertical axis to swing from a position aligned with the head to a position at right angles thereto, movable gripping jaws in the chuck to grip a work piece, means to turn the chuck on the carriage as the carriage moves, means to move the gripping jaws to gripping p-osition as the chuck turns, auxiliary jaws on the chuck yieldingly urged into gripping engagement with a work piece in the chuck, and means to open the auxiliar jaws during movement of the chuck in one direction.

2. Feeding mechanism for nipple threading machines and the like having a head rotatable on a horizontal axis comprising a carriage movable horizontally toward and away from the head, a chuck pivoted on the carriage on a vertical axis to swing from a position aligned with the head to a position at right angles thereto, movable gripping jaws in the chuck to grip a work piece, means to turn the chuck on the carriage as the carriage moves, means to move the gripping jaws to gripping position as the chuck turns, auxiliary jaws on the chuck yieldingly urged into gripping engagement with a work piece in the chuck, and a cam movably mounted on the carriage and engageable with the auxiliary jaws to yield when the chuck turns in one direction and to cam the auxiliary jaws open when the chuck turns in the other direction.

3. Feeding mechanism for nipple threading machines and the like comprising a pair of carriages, means for moving the carriages simultaneously in parallel paths, a chuck pivoted. on a vertical axis on each of the carriages, movable jaws in the chucks to grip work pieces, guide means simultaneously to turn the chucks in opposite directions as the carriages move from a position in which the chucks are aligned to a position in which they are parallel to each other, the chucks having openings therethrough of a size to pass a work piece whereby a work piece can pass from one chuck to the other when the chucks are aligned, and a transfer mechanism between the chucks when the chucks are aligned to receive a work piece from said one of the chucks and feed it into the other chuck.

4. Feeding mechanism for nipple threading machines and the like comprising a pair of carriages, means for moving the carriages simultaneously in parallel paths, a chuck pivoted on a vertical axis on each of the carriages, movable jaws in the chucks to grip work pieces, guide means simultaneously to turn the chucks in opposite directions as the carriages move from a position in which the chucks are aligned to a position in which they are parallel to each other, the chucks having openings therethrough of a size to pass a work piece whereby a work piece can pass from one chuck to the other when the chucks are aligned, and a transfer mechanism between the chucks when the chucks are aligned to receive a work piece from said one of the chucks and feed 5. Feeding mechanism for nipple threading machines and the like comprising a pair of carriages, means for moving the carriages simultaneously in parallel paths, a chuck pivoted on a vertical axis on each of the carriages, movable jaws in the chucks to grip work pieces, guide means simultaneously to turn the chucks in opposite directions as the carriages move from a position in which the chucks are aligned to a position in which they are parallel to each other, the chucks having openings therethrough of a Size to pass a work piece whereby a work piece can pass from one chuck to the other when the chucks are aligned, and a transfer mechanism between the chucks when the chucks are aligned to receive a work piece from said one of the chucks and feed it into the other chuck, the transfer mechanism including a trough tiltable about a horizontal axis between a position horizontally aligned with the chuck jaws and a position tilted downward toward the other chuck, a stop projecting into the lower end of the trough when it is titlted downward and movable out of the trough when it is horizontal, and a feeder member movable horizontally through the trough to force a work piece therefrom into the other chuck when the trough is horizontal and to pass over a work piece in the trough When the trough is tilted.

GEORGE E. MARSDEN.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 409,786 Hartness Aug. 27, 1889 571,434 Fergusson Nov. 17, 1896 735,845 Vanderbeek Aug. 11, 1903 1,864,897 Ewing June 28, 1932 2,227,620 Armitage et al Jan. 7, 1941 2 514,775 Mackintosh July 11, 1950

Images