US2704525A - Attachment for sewing machine - Google Patents

Description

March 22, 1955 B. F. RENN ATTACHMENT FOR SEWING MACHINE 2 Sheets-Sheet 1 Filed July 24, 1953 INVENTOR. fieizizz'efifiierzfz,

ATTEI R N EYS March 22, 1955 R ATTACHMENT FOR SEWING MACHINE 2 Sheets-Sheet 2 Filed July 24, 1953 I IN 'ENTO R. fiezzzzzemeizfz,

ATTD RN EYS United States Patent ATTACHMENT FOR SEWING MACHINE Bennie F. Renn, Jefferson City, Mo.

Application July 24, 1953, Serial No. 370,123

4 Claims. (Cl. 112-67) This invention relates to a sewing machine, and more particularly to a mechanism for automatically and s1- multaneously raising and lowering the presser foot and actuating the starting lever of a sewing machine.

The object of the invention is to provide a sewing machine wherein a single attachment is provided for raising the presser foot and tripping or starting the sewing machine.

Another object of the invention is to provide a labor saving attachment wherein a single foot treadle can be used to operate both the work clamp and to start the stitching cycle.

Another object of the invention is to provide a servo control for sewing machines, bar tackers, button sewers, fiy tackers, tick-tackers and the like, wherein a single pedal can be used for raising the presser foot and starting the sewing machine.

A further object of the invention is to provide a sew ing machine attachment which is extremely simple and inexpensive to manufacture.

Other objects and advantages will be apparent during the course of the following description.

In the accompanying drawings, forming a part of this application, and in which like numerals are used to designate like parts throughout the same:

Figure 1 is an end elevational view of the sewing machine attachment, and showing the position of the parts when the sewing machine is not running.

Figure 2 is a fragmentary top plan view of the attachment.

Figure 3 is a view similar to Figure 1, but showing the position of the parts when the sewing machine is working or running.

Figure 4 is a view showing the locking dog in normal position when the sewing machine is not running.

Figure 5 is a fragmentary elevational view showing the thread cutting arm.

Figure 6 is a horizontal sectional view taken through the shaft and showing the clamp with the case hardened p ate.

Figure 7 is a front elevational view of the clamp of Figure 6.

Figure 8 is an elevational view showing the equalizing arm in starting position.

Figure 9 is a view similar to Figure 8, but showing the initial position of the parts in the event that the chain leading to the presser foot stops moving.

Figure 10 is a view similar to Figure 8 but showing the position of the parts if the shaft stops moving first.

Figure 11 is a view showing the dog in latched or locking position with respect to the clamp.

Figure 12 is a view similar to Figure 11 but showing the parts in released position.

Referring in detail to the drawings, the numeral 10 designates the base or bed of the sewing machine which may be any type of sewing machine of conventional construction. The usual pulley 11 is provided, and the attachment of the present invention includes an L-shaped bracket 12 that may be made of any suitable material such as metal. The bracket 12 includes a vertically disposed portion 14 and a horizontally disposed portion 15, Figures 1 and 3, and an inclined brace'16 extends between the portions 14 and Hand is secured thereto in any suitable manner, as for example by welding. A bearing 17 is secured to the vertical portion 14 of the bracket 12 for a purpose to be later described.

Slidably mounted in the bearing 17 is a vertically 2,704,525 Patented Mar. 22, 1 955 shiftable shaft 18 which is provided with a head or cap 19 on its upper end. A coil spring 20 is circumposed on the shaft 18 and is interposed between the head 18 and the bearing 17 for normally urging the shaft 18 into its raised position as shown in Figure 1.

Positioned on the shaft 18 below the bearing 17 is a clamp 21, there being a set screw 22 for maintaining the clamp in place on the shaft. A case hardened plate 23 is secured to the clamp 21 by suitable screws or bolts 24, Figures 6 and 7. The case hardened plate 23 is adapted to be engaged by a hook 25 on the upper end of a pivotally mounted dog 26, Figures 11 and 12. The dog 26 is pivotally connected to a bracket 28 by means of a bolt and nut assembly 27 which extends through the bracket 28 that is secured to the vertical portion 14, Figure 1. Formed integral with the lower end of the locking dog 26 or secured thereto is a yoke 29 of substantially U-shape, and the yoke 29 has a straight section or flat section 30 extending therefrom for a purpose to be later described, The flat portion 30 of the locking dog 26 is adapted to be engaged by a thread cutting arm 31 which is pivotally connected to the sewing machine by means of a pin 32, Figure 5. Thus, when the thread cutting arm 31 moves over to engage the portion 30 the locking dog 26 will move from the position shown in Figure 11 to the position shown in Figure 12 so that spring 20 can move the parts from the position shown in Figure 3 to the position shown in Figure 1.

The numeral 33 designates the trip lever for starting the sewing machine in the usual manner, and the numeral 34 indicates a chain which extends between the trip lever 33 and an end of an equalizing arm 35. The lower end of the vertically sliding shaft 18 is provided with a slot or cut-out 36 and an end of the equalizing arm 35 is pivotally mounted in the slot 36 by means of a pin 37. A pull down chain 38 is connected to the equalizing arm 35, and the pull down chain 38 may be manually actuated or it may be connected to a conventional foot treadle. Thus, by actuating such a foot treadle the pull down chain 38 can be moved to trip lever 33 to stop the sewing machine and also the presser foot can be lowered as later described in this application.

Mounted on the base of the sewing machine is a bracket 39 which has a bottom portion 40 secured to the sewing machine by a bolt or screw 41. A pair of spaced parallel apertured ears 42 extend upwardly from the bracket, and a lever 43 is pivotally mounted between the ears 42 by means of a pin 44. One end of the lever 43 is bifurcated as at 45 for slidably receiving the shaft 18, the bifurcated end 45 being interposed between the clamp 21 and the bearing 17. A chain 46 is connected to the other end of the lever 43, and the chain 46 may be connected to the usual presser foot or clamping foot of the sewing machine. When the lever 43 is in the position shown in Figure 1 the clamp or presser foot is raised from the work, and when the parts are in the position shown in Figure 3 the pivotal movement of the lever 43 permits the presser foot to lower or rest on the work being sewed.

From the foregoing it will be seen that there has been provided an attachment for a sewing machine whereby a single foot treadle connected to the chain 38 can be used for simultaneously lowering the presser foot which is operatively connected to the chain 46 and for also actuating the trip lever 33 which energizes the sewing machine or starts the cycle of stitching. In use by pressing down on the treadle connected to the chain 38, the equalizing arm 35 will be moved downwardly from the position shown in Figure 8 or from the position shown in Figure 1 to the position shown in Figure 3. As the arm 35 moves downwardly it pulls the shaft 18 downwardly and the shaft 18 carries the clamp 21 therewith. When the clamp 21 gets below the hook 25 of the lockmg dog 26, the spring 47 urges the locking dog 26 from the position shown in Figure 12 to the position shown in Figure 11 so that the shaft 18 is maintained in its downward position as shown in Figure 3 during the sewing operation. When the parts are in the position shown in Figure 1 the lever 43 is maintained in a substantially horizontal position, but when the shaft 18 moves downwardly, the lever 43 is permitted to pivot in a counterclockwise direction so that the chain 46 permits the presser foot to drop onto the work at the same time that the trip lever 33 actuates the sewin machine. The spring 47 is circumposed on the bolt and nut assembly 27, as shown in Figure 2 of the drawings, and one end of the spring 47 is arranged in engagement with a suitable aperture or opening in the bolt of the bolt and nut assembly 27. The other end of the coil spring 47 is arranged in engagement with a suitable aperture or opening in the locking dog 26 as shown in Figure 4 so that the coil spring exerts a constant pressure on the locking dog 26. After the completion of the sewing operation, the thread cutting arm 31 automatically moves over and engages the flat portion 30 on the yoke 29 to thereby pivot the dog 26 from the position shown in Figure 11 to the position shown in Figure 12 whereby the spring 20 returns the parts to the position shown in Figure 1. Thus, the lever 43 will be pivoted from the position shown in Figure 3 back to the position shown in Figure 1 so that the presser foot connected to the chain 46 will be automatically raised away from the work. Further, with the parts returned to the position shown in Figure 1 the trip lever 33 will de-energize the sewing machine at the same time.

The present attachment provides a completely automatic mechanism so that the work clamp or presser foot and stitching cycle can be started by one treadle at the same time. The attachment can be used on Singer sewing machines, bar tackers, button sewers, fly tackers, tick-tackers and the like. Ordinarily these machines require two foot pedals for raising the foot and tripping or starting the machine but with the present attachment both operations are accomplished with the use of only one foot pedal. After the machine has completed the sewing operation and upon the thread cutting operation of the machine, the thread cutting bar 31 moves to release the catch or dog 25. The case hardened portion or plate 23 which is engaged by the hook 26 insures that there will be no excessive wear on this part.

After the completion of the sewing operation, the thread cutting bar 31 is moved to pivot or unlock the dog 26 from the clamp 21. The dog 26 when in the position shown in Figures 3 and 11 serves to maintain the parts down as shown in Figure 3 during the sewing cycle. After the completion of the sewing cycle, the thread cutting bar 31 moves over and trips the dog 26 to permit the spring 20 to move the shaft 18 and lever 43 back to the position shown in Figure 1. When the sewing machine is not operating, the equalizing arm 35 is horizontal as in Figure 8. In the event that the chain 46 resists downward movement while the shaft 18 moves downward as in Figure 9, continued downward pulling on the equalizing arm 35 by means of the chain 38 will then pull the chain 34 downward so that the presser foot and trip lever will eventually be actuated. Similarly, as shown in Figure if the chain 34 moves downward ahead of the shaft 18, continued downward pulling on the arm 35 by the chain 38 will result in eventual downward movement of the shaft 18. The trip lever 33 may be used for starting the motor that operates the sewing machine. The mechanism of the present invention can be used on various types of conventional sewing machines as for example the mechanism can be used on the following types of Singer sewing machines. Machines of the bar tacker Class 69-5; tacker Class 114 31; button sewerfly tacker Class 69 18669-26.

I claim:

1. In a sewing machine, a base, an L-shaped bracket secured to said base, a bearing secured to said bracket intermediate the ends thereof, a shaft slidably mounted in said bearing, a head mounted on the upper end of said shaft, a coil spring circumposed on said shaft and interposed between said head and bearing, a body member secured to said base, a lever pivotally connected to said body member and provided with a bifurcated end for slidably engaging said shaft, a clamp secured to said shaft and spaced below said lever, a chain connected to an end of said lever, and adapted to be connected to a presser foot, a pivotally mounted dog provided with a hook on its upper end mounted for movement into and out of engagement with said clamp, there being a slot in the lower end of said shaft, an equalizing arm extending into said slot and pivotally connected to said shaft, a chain having its lower end connected to said arm and its upper end adapted to be connected to a trip lever for starting the sewing machine, and a pull chain con nected to said arm intermediate its ends.

2. The apparatus as described in claim 1, and further (iincluding a spring arranged in engagement with said 3. The apparatus as described in claim 1, and further including a case hardened plate secured to said glamp and adapted to be engaged by the hook on said 4. In a sewing machine, a base, a bracket secured to said base, a bearing secured to said bracket intermediate the ends thereof, a shaft slidably mounted in said hearing, a head mounted on the upper end of said shaft, resilient means circumposed on said shaft and interposed between said head and bearing, a body member secured to said base, a lever pivotally connected to said body member and slidably engaging said shaft, a clamp secured to said shaft and spaced below said lever, a chain connected to an end of said lever, and adapted to be connected to a presser foot, a pivotally mounted dog provided with a hook on its upper end mounted for movement into and out of engagement with said clamp, there being a slot in said shaft, an equalizing arm extending into said slot and pivotally connected to said shaft, a chain having its lower end connected to said arm and its upper end adapted to be connected to a trip lever for starting the sewing machine, and a pull chain connected to said arm intermediate its ends.

References Cited in the file of this patent UNITED STATES PATENTS 806,231 Allen Dec. 5, 1905 1,221,254 Weis Apr. 3, 1917 1,822,854 Allen Sept. 8, 1931 2,540,730 Hayes Feb. 6, 1951

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