US3649057A

US3649057A - Easy pattern disc removal devices

Info

Publication number: US3649057A
Application number: US71169A
Authority: US
Inventors: John A Urciola
Original assignee: Singer Co
Current assignee: SSMC Inc
Priority date: 1970-09-10
Filing date: 1970-09-10
Publication date: 1972-03-14
Anticipated expiration: 1989-03-14

Abstract

In a cam controlled, needle jogging ornamental stitch sewing machine, a cam removal mechanism is provided for elevating a seated pattern cam from the interior portion of the sewing machine, to an accessible position. A trifurcated, resilient, bowed retaining means is slidable within an axial bore in a central hub and operatively connected to a spring biased plunger. When the pattern cam is in the seated position, the retaining means overlies the pattern cam. When the plunger is depressed, the retaining means is pushed below the seated cam until it underlies the cam, whereupon the spring biased plunger is released and the retaining means raises upwardly carrying the cam with it.

Description

United States Patent Urciola Mar. 14, 1972 [54] EASY PATTERN DISC REMOVAL DEVICES [72] inventor: John A. Urciola, South Bound Brook, NJ. [73] Assignee: The Singer Company, New York, NY.

[22] Filed: Sept. 10, 1970 21] Appl. No.: 71,169

Primary Examiner-Andrew V. Kundrat Attorney-Marshall J. Breen, Chester A. Williams, Jr. and Robert E. Smith [57] ABSTRACT In a cam controlled, needle jogging ornamental stitch sewing machine, a cam removal mechanism is provided for elevating a seated pattern cam from the interior portion of the sewing machine, to an accessible position. A trifurcated, resilient, bowed retaining means is slidable within an axial bore in a central hub and operatively connected to a spring biased plunger. When the pattern cam is in the seated'position, the retaining means overlies the pattern cam. When the plunger is depressed, the retaining means is pushed below the seated cam until it underlies the cam, whereupon the spring biased plunger is released and the retaining means raises upwardly carrying the cam with it.

3 Claims, 5 Drawing Figures Patented March 14, 1972 3,649,057

INVENTOR'. John A. UrcIoIa T ESS= ATTORNEY EASY PATTERN DISC REMOVAL DEVICES BACKGROUND OF THE INVENTION In an ornamental stitch sewing machine of the type described in US. Pat No. 2,862,468, Dec. 2, 1958, to R. E. Johnson for an Omamental Stitch Sewing Machine, the

stitch pattern is controlled by a stitch pattern cam which is housed within the sewing machine frame. The stitch pattern cam causes the lateral jogging of the needle bar and this forms a particular stitch pattern. It is desirable to be able to form a variety of different stitch patterns, and for this reason, there are different cams available which may be exchanged in the sewing machine frame with other stitch pattern cams so that the desired variety of stitch patterns may be formed.

The stitch pattern cam is usually mounted in the upper portion of the overhanging arm of a sewing machine frame fast on a rotating cam shaft. The pattern cam, therefore, must be tightly mounted on the cam shaft in order to rotate with the cam shaft without slipping. Access to the seated pattern cam is provided through a limited access opening in the top surface of the overhanging arm of the sewing machine frame. To exchange one pattern cam for another, the operator must reach through this limited access opening and pry the cam loose from its seated position. This procedure is often frustrating and may result in broken fingernails and soiled fingers.

The stitch pattern cam is typically a flat disc with a central boss rising therefrom so that the operator will be able to exchange the cam from the machine by grasping the boss portion of the pattern cam disc. This central boss adds to the height of the cam, making it approximately three times as high as the flat disc portion, thereby increasing the storage area requirements threefold.

SUMMARY OF THE INVENTION In accordance with the present invention, a sewing machine having a jogging or laterally oscillatory needle controlled by a pattern cam mounted on a rotating cam shaft, is provided with a cam removal mechanism incorporated into the upper portion of the cam shaft. The cam removal mechanism, mounted on the cam shaft which may have a stack of permanently mounted cams thereon, includes a flange beyond which the cam shaft extends. Above the flange, the cam shaft is divided by radial slots into a plurality of vertical, spaced-apart sections comprising a central hub. Mounted within the cam shaft is a plunger which is spring biased into an up position. Cooperatively associated with the plunger, and axially slidable within the cam shaft, is a retaining means which has plurality of radially extending bowed fingers. Theses bowed fingers extend outwardly of the cam shaft in the slots between the plurality of spaced apart vertical sections in the cam shaft. A pattern cam may be mounted onto the cam shaft and seated on a cam seat supported by the flange when the bowed fingers of the retaining means overlie the cam. When the spring biased plunger is depressed, the retaining means is urged downwardly until its bowed fingers underlie the pattern cam, and then the plunger is released allowing the retaining means and the pattern cam to raise upwardly into an accessible position.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevational view of the cam removal mechanism of this invention as applied to a sewing machine cam shaft with the upper portion of the cam shaft cut away to show the inner portion of the cam removal mechanism, and also showing a pattern cam in its seated position'on the cam shaft.

FIG. 2 is an elevational view similar to that of FIG. 1, with the lower portion of the cam shaft partially omitted and showing the upper portion of the cam shaft with the plunger depressed and the retaining means underlying a pattern cam.

FIG. 3 is a view similar to that of FIG. 2, but showing the pattern cam raised on the cam shaft.

FIG. 4 is a top plan view showing the cam removal mechanism without a cam mounted thereon.

FIG. 5 is an exploded perspective view of the cam removal mechanism and the pattern cam.

DETAILED DESCRIPTION OF THE INVENTION In an-omamental stitch sewing machine, there may be provided means for laterally jogging the needle bar so that the needle will sew a zigzag pattern. The means provided is usually linkage which causes the needle bar to oscillate, a cam to program the lateral oscillations, and a cam follower to transmit the cam program tothe linkage connected to the needle bar. The present invention is useful in the above described embodiment in that it provides a simple and effective means for removing the pattern cam from a sewing machine so that a different pattern cam may be inserted for sewing a different pattern.

Only a sewing machine pattern cam shaft is illustrated in the drawings, it being understood that this cam shaft may be incorporated into any conventional pattern cam controlled zigzag sewing machine. It should also be noted that the cam shaft of this invention may also be formed with permanent cams incorporated thereon as is known in the prior art but not shown in the drawings.

An exchangeable pattern cam 11 may be mounted on a cam shaft 13-having an axial bore 15. The cam shaft is rotatable about an axle 17, which may be secured in a sewing machine frame (not shown). The top portion of the axle is formed with a screw head 19 for adjusting the axle position within the sewing machine. The cam shaft is caused to rotate by a driven gear 21 integral with the cam shaft and the cam shaft is retained on the axle by a C shaped clip 23.

The upper portion of the cam shaft is split into three spaced apart vertical sections constituting a central'hub 27, with radial slots 29 between each of the three vertical sections. A cam seat locator flange 31 is formed between the spaced apart vertical sections and the remainder of the cam shaft; the flange, supporting a cam seat 33. The cam seat is held to the flange by means of a pair of screws 35 which pass through a pair of arcuate apertures 37 and are threaded into holes 39 in the flange. The purpose of the arcuate apertures is to allow for angular adjustment of the cam seat. A vertical key 41 is integral with the cam seat and extends parallel to the central hub providing a means for aligning the pattern cam to the cam shaft.

A coil compression spring 43 is mounted within the axial bore of the cam shaft, having its lower extremity supported by and abutting the upper portion of the axle 17. Endwise slidable in a central bore 45 of a bushing 47 threaded into central hub portion of thecam shaft is a plunger including a button portion 49, and a shaft portion 51 terminating in a reduced shoulder portion 53. A cam retaining means 55 is fixed to the shoulder portion of the plunger shaft by a C" shaped clip 57 which engages an annular groove 58 in the shoulder portion 53 of the plunger.

The retaining means includes a washer-like central portion 59 having three equally spaced radially outwardly and upwardly extending resilient fingers 61. The .upper extremity of each resilient finger contains a cambered portion 63 which allows the resilient fingers to be smoothly urged inwardly into the central hub as a cam is being inserted onto the cam shaft or as the plunger is being depressed to actuate the cam removal. The washer-like central portion of the retaining means engages the plunger shaft at its shoulder portion. The effect of this construction is that the plunger and the retaining means both are permitted to travel within the axial bore of the central hub in the vertical direction. Clearance recesses 65 are formed in the flange 31 to allow maximum travel of the retaining means.

As shown in the drawings each exchangeable pattern cam 11 is formed with a central opening 67 from which a radial cutout 69 extends. To seat the cam 11 on the cam seat, it is first necessary to align the central opening 67 and the radial cutout 69 of the pattern cam respectively with the central hub 27 and the vertical key 41 of the cam removal device. Once this is accomplished, a downward vertical force is exerted in the cam 11 which forces the plunger assembly including the retaining means downwardly. At some point in the downward movement of the pattern cam, the resilient arms of the retaining means will be urged radially inwardly into the central hub by the lower edge 71 of the pattern cam central opening until the cam slips over the cambered portion of the resilient arms causing the plunger and the retaining means to pop up and lock the pattern cam onto the cam seat. Because the resilient arms of the retaining means are bowed radially outwardly they will then overlie the seated cam. The preceding sequence of operation is best followed by viewing the drawing in the order of FIGS. 3, 2 and 1.

To unseat a seated pattern cam, the plunger is depressed against the action of the compression spring 43. As the plunger is depressed, the resilient arms of the retaining means bear against the upper edge 73 of the pattern cam central opening which causes the resilient arms to travel inwardly according to the curvature of the cambered portion until they slip below the seated pattern cam. At this point, the resilient arms again bow radially outwardly but now they underlie the pattern cam and as the plunger assembly including the retaining means is released against the force of the compression spring 43 the plunger assembly including the retaining means and the seated pattern cam are all carried upwardly on the cam shaft where the cam will be accessible to the operator. This operation is best followed in the sequence of FIGS. 1, 2 and 3.

It will be understood that various changes in the details, material, arrangement of parts and operating conditions, which have been herein described and illustrated in order to explain the nature of the invention, may be made by those skilled in the art without departing from the scope and principles of this invention.

The construction of this invention is thus of utmost simplicity requiring one moving assembly comprising the plunger 51 with the pattern cam retaining resilient fingers 61 attached thereto, and a coil spring 43 urging the assembly upwardly. The resilient fingers 61 are so outwardly bowed with the free ends inturned that the central opening 67 of pattern cam may be forced past the fingers readily, or vice versa. The fingers may readily be forced through the central opening of a pattern cam. The resilient fingers 61 thus either overlie a pattern cam to retain it in place, or they underlie a pattern cam and serve as an intermediate element in biasing the pattern cam into a raised position for convenient exchange of pattern cams.

Having thus set forth the nature of the invention what we claim as new:

1. A device for releasing and elevating an exchangeable pattern cam disc from a cam seat on a cam shaft in a sewing machine, including:

a. a hub portion on said cam shaft including a free extremity extending from said cam seat;

b. said cam shaft being formed with an axial bore extending through said hub portion with at least one radial slot opening from said bore to the exterior of said hub portion;

0. a plunger slidable in said axial bore;

d. spring means biasing said plunger toward the free extremity of said hub portion;

e. a resilient pattern cam retaining finger carried by said plunger and located in said radial slot in said hub portion;

f. said resilient pattern cam retaining finger extending through said hub portion to a position radially outwardly of said hub portion and including a free extremity bent inwardly and tenninating within said slot 2. The device as set forth in claim 1 wherein three pattern cam retaining fingers extend through three substantially equally spaced radial slots in the hub portion, the three retaining fingers being attached to a washer-like central portion which is carried by the plunger.

3. The device as set forth in claim 1 wherein the axial bore of the cam shaft hub portion accommodates a threaded bushing formed with an axial bore in which said plunger is slidably constrained.

Claims

1. A device for releasing and elevating an exchangeable pattern cam disc from a cam seat on a cam shaft in a sewing machine, including: a. a hub portion on said cam shaft including a free extremity extending from said cam seat; b. said cam shaft being formed with an axial bore extending through said hub portion with at least one radial slot opening from said bore to the exterior of said hub portion; c. a plunger slidable in said axial bore; d. spring means biasing said plunger toward the free extremity of said hub portion; e. a resilient pattern cam retaining finger carried by said plunger and located in said radial slot in said hub portion; f. said resilient pattern cam retaining finger extending through said hub portion to a position radially outwardly of said hub portion and including a free extremity bent inwardly and terminating within said slot.

2. The device as set forth in claim 1 wherein three pattern cam retaining fingers extend through three substantially equally spaced radial slots in the hub portion, the three retaining fingers being attached to a washer-like central portion which is carried by the plunger.