US1462650A - Presser-foot latch - Google Patents

Description

Patented July 24, 1923.

innran stares earner errant HYMAN MAIMIN AND nastier rniironv, or roan, 1\T. Assieuous T0 H. MAIMIN 00.. Inc, a. CORPORATION or new YORK.

raassemom LATCH.

Application filed January 4, 1922. Serial No. 526,873.

To all whom it may concern:

Be it known that we, HYMAN Martin: and AUGUST FREDDY, citizens of the United States, residing at New York, county and State of New York, and whose post-oflice address is 251 West 19th Street, New York city, N. Y., have invented certain new and useful Improvements in PresserFoot Latches; and we do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it apper tains to make and use the same.

Our invention is an improvement in presser foot latches for cloth cutting machines, and relates particularly to machines of the reciprocating type.

, In machines of this character, the presser foot serves a double function, acting as a guard for the reciprocating knife or blade, in addition to holding the material against upward movement with the knife, that is stripping the cloth from the knife. Hence it is necessary that the foot be held against possibility of accidental displacement by the cloth clinging to thelmife. while on the other hand it may be easily and quickly adjusted, either to release the cloth, or to permit the insertion of different thickness of cloth between the foot and the base of the machine. It is also desirable, to facilitate the engagement of the cutting machine with the cloth, that the foot be supported against downward movement, and against accidental displacement from its lifted position, when it is lifted. It is desirable that the'means for holding the presser foot against movement in either direction be easily and quickly releasable, in order to facilitate the adjustment of the foot, and with a minimum of time, to prevent a diminution of efficiency in the machine. It is also desirable that the presser foot be under the control of the operator when the pawls are released. And above all, a positive lock is desired.

It is the object of the present invention to provide a presser foot latch which shall possess these desirable qualities. This object we have attained by mounting upon the presser foot a double pawl cooperating with a fixed rack on the frame of the machine, one pawl element locking the presser foot against upward movement and the other locking it against downward movement, and

both pawls being capable of simultaneous release by the operator;

In the accompanying drawings which illustrate a preferred embodiment of the invention- Figure 1 is a side elevation of a cloth cutting machine of the reciprocating type, equipped with a presser foot latch in accordance with the present invention.

Figure 2 is a front view of the presser foot and its mounting,

Figure 3 is a section on the line 33 of Figure '52,

Figure 4 is a section on Figure 3.

In the present embodiment of the inven- 70 tion, the cloth cutting machine comprises a base 1, from which arises a standard 2 havthe line -i- 1 or ing connected therewith a handle 3, and supporting a motor t. for reciprocating the knife indicated. at 5, in a well known manner.

As is usual in machines of this character, a

pair of knife guard members is provided, and each of the said members carries at its lower end a stripper foot or presser foot 7, the said members 7 being on opposite sides of the knife 5, the guards 6 are pivoted at their upper ends to a carriage or support 8, which is mounted to slide vertically on a track or guide 9 supported by the frame of the machine. The members 6 are normally pressed toward each other by a coil spring 10 arranged between them near their pivotal connection, and at each of the pivots 11 connecting the guards 6 to the carriage 8 a spur gear 12 is arranged, the said gears being rigid with the knife guards 6. The spur gears mesh with each other so that when either of the knife guard members is swung outwardly and upwardly, the other member will be swung in unison therewith, and the spring 10 is so arranged that it will press the guards members toward each other, whether the spring is above or below the pivotal connection. The spring 10 has its ends connected with pins on the respective spur gears 12.

A rack or ratchet bar 13 is held in a groove in the outer face of a T shaped track bar 141, which is supported by the frame, being connected thereto by screws 15, and the teeth of the rack bar are faced outwardly. The carriage 8 is longitudinally slotted from its upper end as indicated at 1.6, and a pair of pawls 17 and 18 is pivoted in the slots, the pawls cooperating with the teeth of the rack or ratchet'bar 13. The pawls are oppositely arranged, as shown in Figure 3, the pawls 17 inclining upwardly to engage the teeth of the rack bar to prevent downward movement of the carriage, while the pawl 18 inclines downwardly to engage the teeth to prevent upward movement of the carriage. Each of the pawls 17 and 18 has an angular extension 19 in the form of a finger piece, and these extensions lie alongside each other, so that they may be simultaneously grasped between the thumb and finger. A coil spring 20 is arranged between the finger pieces, passing through an opening in an extension 21 from the carriage, and the spring acts normally to press the pawls into engagement with the ratchet bar. The ends ot' the spring are held from displacement by pins 22 on the finger pieces. In practice the extension 21 is on a block 23 which is set in a transverse recess in the carriage.

In operation, when it is desired to adjust the presser foot, both pawls may be released, in which condition of affairs, the carriage may be moved in either direction. The operator by grasping the finger pieces of the pawls, supports the presser foot when the pawls are released. The presser foot, therefore, cannot drop and adiustment can be effected with one hand. By operating the pawls in alternation, either may be caused to act as a brake on the movement of the carriage in the opposite direction. The apparatus permits a very quick and easy adjustment of the presser foot, to any desired position, and is an absolute lock against the accidental movement of the foot. The machine is operated in the usual manner, by pushing it through the pile of goods to be out while the knife is being reciprocated by the motor. During the cutting operation, the knife guard members occupy a position on each side of the blade, and in front of the same, and with the stripper foot compressing the pile of goods with the required pressure.

e claim:

1. A cloth-cutting machine comprising the combination of a supporting frame, a rack fixed thereto, a presser toot movable relative to the frame, and a double pawl carried by the presser foot and cooperating with the rack.

2. In a cloth-cutting machine, a stripper and presser foot mounting, comprising double pawl and ratchet mechanism for holding the foot from movement in either direction, the pawls being arrangedadj acent,

.and in such manner that they may be operated simultaneously or in alternation, said mechanism comprising a fixed rack bar, and pawls on the presser foot inclining away from each other to engage the rack bar, said pawls having thumb pieces adjacent to each other, and spring between the thumb pieces pressing both into engagement with the rack bar.

In testimony whereof we aiiix our signatures.

HYMAN MAIMIN. AUGUST FREDDY.

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