US536891A - pearson - Google Patents

Description

( NoModeL) 2 Sheets-Sheet 1. M. H. PEARSON.

SEWING MACHINE.

No. 536,891. Patented A pr. Z, 1895.

. Q C 6 v (No Model.) 2 Sheets-Sheet 2. M. H. PEARSON.

' SEWING MACHINE.

No. 536,891. Patented Apr..2, 1895.

Z B c ItlT/VESSES Allow: e J,

. NITED STATES PATENT Orrin,

MARSHALL HENRY PEARSON, OF LEICESTER, ENGLAND, ASSIGNOR TO THE JOHN OFLAHERTY COMPANY, OF MONTREAL, CANADA.

SEWING-MACHINE.

SPECIFICATION forming part of Letters Patent No. 536,891, dated April 2, 1895.

Application filed August 1'7, 1894. Serial No. 520,593. (No model.) Patented in England March 29, 1893 1 To all whom it may concern.-

Be it known that I, MARSHALL HENRY PEAR- SON, a citizen of England, residing at Leicester, in the county of Leicester,England, have invented certain new and useful Improvements in Sewing-Machines, (for which I have received Letters, Patent of Great Britain, No. 6,656, dated March 29, 1893,) of which the following is a specification.

This invention is applicable to most kinds ofsewing machines, but being especially useful with machines employing a waxed thread, as in the stitching of leather or the like, I will now describe it in that connection, it being understood that I do not restrict the application of my invention to that particular type of my machine.

The invention deals with the treatment of the thread as to the tension, the taking-up'or tightening of the loop, the locating of the lock in or upon the material being stitched, and so far as waxed and similar threads are concerned, to the waxing of the thread.

The details of the invention will necessarily vary with the different types of machines to which the invention is applied, notwithstanding that the same features would be substantially present in all, and in the accompanying drawings I have merely shown as an example my invention as applied to a machine of the Thomas type.

In the drawings,Figures 1 and 2 are respectively an elevation and a plan of the upper portion of a sewing machine provided with my improvements, showing the needle thread nipping device operated by the shuttle lever. Figs. 3 and 4, Sheet 2, are views respectively similar to Figs. 1 and 2, showing alternative mechanism for operating the thread nipping device. Fig. 5 is a face view and Fig. 6, a plan of the shuttle; and Figs. 7

, and 8 are respectively a front elevation and a plan of the needle-thread waxing device.

Like letters indicate like parts throughout the drawings.

In applying my invention to a machine of, say, the Thomas type, as illustrated in the accompanying drawings, I place upon a suitable part of the frame work A, conveniently on top, a flat table A, conveniently a part of the frame casting, and of suitable dimensions vice 0 between them, are penetrated by a bolt 0 conveniently square, as indicated in dotted lines in Fig. 2, to prevent its turning and passing through the table A and other desired portion of the casting or frame work A of the machine. The bolt C may be provided with a head or equivalent 0 adapted to be engaged by any suitable moving part of the machine, by which the bolt (3 and its plates 0 O O can be drawn downward and thus grip the thread firmlybetween the plate 0 and the table A. In the Thomas machine this may be conveniently arranged by forming a lug or equivalent projection D upon the shuttle lever D, so that at the proper time it engages with the head (3 or other suitable part of the bolt 0 pulling it and the plates 0 O 0 down. Any suitable spring arrangement may be employed to adjust the pressure or take oif unnecessary shock orjar in the operation. When the pressure is relaxed the plates 0 C 0 lie upon the thread Band hold it between the lower plate 0 and the table A by their own weight, supplemented if desired by a small spring 0 the pressure of which can be adjusted, and which may be conveniently in the form of a helical spring, as shown placed around a small screw 0 passing through the plates 0 O C and screwing into the table A, the pressure of the spring 0 in this arrangement being adjusted by screwing C more or less into A.

The alternative mechanism for operating the needle thread nipping device, shown in Figs. 3 and 4, consists of a lever D pivoted at D to the frame work A, and at D to the bolt 0 and near its opposite or free end, provided with an antifriction roller D drawn by a spring E against a cam F on the shaft F, said cam effecting the raising of the lever D, bolt 0 plates O 0 O and spring E, drawing these parts downward whenever the cam F is turned into the position allowing their descent. It will be understood that the position of all the before described mechanism maybe altered but the same eifect obtained.

After passing the above described tension and nipping device, the thread B may be passed through a solution box G, if liquid wax be used, and from there through a guide II, preferably in the form of a staple as shown, and then round a pulley or equivalent I upon the needle bar I, and from there through a suitable tension or guide device J to the needle K. The guide H may be formed in any desired manner, whether of stamped metal, wire or other material, so longas it is provided with an opening in which the thread can traverse when carried backward and forward by the needle bar, this feature being provided for by what is herein designated an elongated thread guide. The operation of these parts is as follows:-The needle K having under the influence of the needle bar 1 and needle bar lever L pivoted at L to I, made its downward stroke and drawn the thread B with it so far as necessary, returns, leaving the necessary loop through which the shuttle passes and then continues its upward journey. In ordinary machines during its upward movement, the eye of the needle K slides over the thread B, scraping the wax oif it and more or less damagingthethread. Inthe presentinstance the thread B travels up with the needle K while it passes through the Work this being accomplishedin the following manner: WVhen the sh uttlo has entered the needle thread loop at the proper moment the previously described nipping device A, O, C C 0 comes into play and holds the thread B so that no more can be drawn, and the needle bar I as it rises, has thus to take the thread B up with it and consequently it rises at the same speed as the needle K, and there is no movement of the thread through the eye of the needle. To effect this, it is desirable that the point at which the thread is held against upward movement should be as far as may conveniently be practicable from the needle bar I, or the pulley I over which it passes. In the present i11- stance this point would be the eye or opening G through which the thread B escapes from the solution box G. IVhen the needle has risen so high that it is clear of the work, and there is only a small portion of the thread left to be pulled in, it is desirable to pull up the thread more quickly through the work, and since the eye of the needle K is clear of the work, no damage will result to the thread if it now slips through the eye. This may be effected by the before mentioned staple guide II. The point at which the thread passes over the pulley I on the needle bar I having now risen to or above the top of the staple H the thread instead of having the long radius from the solution box G or other fixed point G as previously mentioned has now an extremely short one with the result that as the thread B cannot now accommodate itself to the movement of the needle bar I it slips past the pulley I and draws back through the eye of the needle K tightening the loop in the work in a direct pull from the pulley I to the work, thus pullingin and locking the shuttle thread.

The height of the top of the staple or equivalent guide l-I may be Varied after loosening a set screw or other device II, thereby causing more or less thread to be pulled backward past pulley I, and by this means the precise point within the work at which the locking of the two threads takes place can be varied so that the operator can regulate the depth into the Work at which the locking takes place.

During the whole of the lastdescribed operations the thread B has been locked or nipped, but so soon as the needle K has reached the highest point of its travel, the nip is relaxed and the thread can again be drawn whether by the needle K in its next downward stroke or to facilitate the removal of the work from the machine.

The tightness of the stitching is effected by the tension upon the shuttle thread itself, and this I regulate in a manner which, for waxed threads, is of considerable importance. The thread N from the shuttle 0, Figs. 5 and 6, passes through a slot 0 upon one side of the shuttle in the usual way and then through a single hole 0 upon the opposite side of the shuttle. Over this hole is a spring 0 the pressure of which can be regulated and so arranged to allow of the pull of the thread N at either end of the shuttle O with the same amount of tension upon the thread in all positions. The edge of the shuttle closing in one side of the slot 0 is deflected inward as shown in Fig. 5. By this means Iavoid passing the thread N through a number of holes and thus scraping it, and am able to satisfactorily control the tightness of the work.

For the purpose of supplying the wax to the work without waxing more of the thread than is necessary, a well known device is that set forth in Pearsons patent, No. 199,991, dated February 5, 1878, where the needle point dips into a cup kept supplied with melted wax, the cup being supported upon a lover or arm pivoted within a box and having an adjustment screw to regulate the depth to which the needle enters the Wax and thus to regulate the amount of wax taken up at each stroke.

In the present arrangementI employ a similar device,but I pivot the cup lever'or arm P outside the box Q and employ preferably in connection with the adjustment screw P a sliding cam plate B, so arranged that when moved in one direction to the leftit elevates the lever P and the cup P to the highest position, thus giving the needle K its full dip, and when moved in the opposite direction it allows the arm and cup to drop, so that the needle does not dip into the wax in the cup. By this means the supply of wax to the needle can be immediately checked, while the regulation by the screw P is just as perfect as before. If preferred, the screw P may be IIO entirely dispensed with, the cam plate R being so shaped as to afford the necessary amount of elevation to the armP and cup P more or less according to the position at which the cam plate R is placed. Any convenient means may be employed to render the plate R movable and prevent it from moving from its appointed position by the vibration of the machine. For example, it may be connected by clips R to the adjacent wall of the box Q, and be retained in position by a screw, spring tension device, rack and pawl or the like.

Having now particularlydescribed and ascertained the nature of my said invention and in what manner the same is to be performed, I declare-that what I claim is 1. In a sewing machine, the combination with the needle bar and the thread guide car-- ried thereby; of a fixed guiding eye G at a distance from the needle bar; a vertically elongated staple H between the needle bar and the fixed guiding eye; and a threaddocking device to act upon the thread prior to entering the fixed eye; whereby on the downward movement of the needle bar the thread can move freely through the staple from the eye G as a center; while on the upward movement of the needle bar the thread can move from the upper end of the staple as a center, substantially as shown and described.

2. In a sewing machine, the combination with a thread or needle-waxing device comprising a box such as Q and a cup arm such as P P, of an adjustable cam plate such as R, substantially as described and illustrated in the accompanying drawings.

Images