US2042651A

US2042651A - Differential feeding mechanism for sewing machines

Info

Publication number: US2042651A
Application number: US17955A
Authority: US
Inventors: Andrew B Clayton
Original assignee: Singer Co
Current assignee: Singer Co
Priority date: 1935-04-24
Filing date: 1935-04-24
Publication date: 1936-06-02
Anticipated expiration: 1953-06-02

Description

June 2, 1936. A. B. CLAYTON DIFFERENTIAL FEEDING MECHANISM FOR SEWING MACHINES Filed April 24} 1935 5 Sheets-Sheet 1 rewB. Clayion June 2, 1936. A. B. CLAYTON 2,042,651

DIFFERENTIAL FEEDING MECHANISM FOR SEWING MACHINES Filed April 24, 1935 5 Sheets-Sheet 2 June 2, 1936. A. B. CLAYTON DIFFERENTIAL FEEDING MECHANISM FOR SEWING MACHINES Filed April 24, 1955 5 Sheets-Sheet 3 WWW Patented June 2, 1936 UNITED STATES PATENT orF eE DIFFERENTIAL FEEDING MECHANISM FOR SEWING MACHINES Application April 24, 1935, Serial No. 17,955

10 Claims.

This invention relates to differential feeding mechanisms for sewing machines and has for an object to provide a variable differential feeding mechanism of the treadle-controlled type which is of simplified and improved construction and which works smoothly and efficiently under high-speed operating conditions. A further object of the invention is the provision of a treadlecontrolled auxiliary or differential feeding mechanism which may be applied to a conventional sewing machine having a well known form of main feeding mechanism, with a minimum of additional parts and required alterations in the machine. The invention also aims to improve and simplify the feeding mechanism disclosed in my prior United States Patent No. 1,602,427, of Oct. 12, 1926, and adapt it for control by the operator without stopping the machine.

With the above and other objects in view, as will hereinafter appear, the invention comprises the devices, combinations, and arrangements of parts hereinafter set forth and illustrated in the accompanying drawings of a preferred embodiment of the invention, from which the several features of the invention and the advantages attained thereby will be readily understood by those skilled in the art.

In the accompanying drawings, Fig. 1 is a top plan view of the bed of a, sewing machine embodying the invention. Fig. 2 is a left end elevation of the machine bed with certain parts of the differential feed controlling mechanism removed. Fig. 3 is a similar view with the removed parts added. Fig. 4 is a rear side elevation of the feeding mechanism. Fig. 5 is a disassembled perspective view of the treadle controlled auxiliary-feed-adjusting lever and its supporting parts. Fig. 6 is a disassembled perspective view showing the reverse sides of the supporting parts shown in Fig. 5. Fig. 7 is a. section on the line l"l, Fig. 1, and Fig. 8 is a section on the line 8-8, Fig. 3.

l represents the bed of a sewing machine from which rises the lugs 2 and 3 fitted with bearing bushings 4 and 5 for the main shaft 6 which extends lengthwise of the bed i and includes the usual inclined actuating crank 1 for the conventional loopers B. The bed i carries at one end the usual bracket-arm standard I shown in section in Fig. l. Rising from the other end of the bed I are the supporting means or posts U, I for the usual throat-plate I having the feed-dog slots l The end-portion 6 of the main shaft 6 is journaled in the bearing bracket 9 which is detachably secured to the grooved seat I!) in the post I by means of a screw l2.

The main feeding mechanism is of usual construction and comprises the main feed-dog I3 carried by the main feed-bar l4 fulcrumed on the pin 15 carried by the feed-rocker it which, in turn, is carried by the fulcrum pin ll journaled in the base lugs E8. The main feed-bar M is disposed as usual at the inner side of the throatplate supporting posts l I, i. e., at the side of such posts nearer the frame-standard W. The feed-rocker I6 is connected by the pin I9 to one end of the pitman 2B which at its other end embraces the usual adjustable feed-advance eccentric 2| on the main shaft 6. Rising and falling movements are imparted to the main feedbar H! by means of the feed-lift eccentric 22 on the main shaft 6; the eccentric 22 being embraced by one strapped end of a pin 23 which is slidably received inthe apertured arm 2d of the feed-bar, The parts so far described are conventional and well known.

The auxiliary or differential feed mechanism comprises the auxiliary feed-dog 25 carried by ,the upstanding auxiliary feed-bar 26 which is fulcrumed at 21, substantially vertically below the auxiliary feed-dog 25, on the crank-arm 2i fixed to one end of the rock-shaft 29 journaled in the post 1 and the bearing lug 3!! on the bed I. The auxiliary feed-bar 26 is disposed at the outer side of the throat-plate supporting posts l t i. e., at the side of such posts more remote from the frame standard E The rock-shaft 29 has fixed .to its other end an arm 3! which is forked to embrace the slide-blocks 32 bearing upon the auxiliary feed-lift eccentric 33 on the main shaft 6. The feed-lift eccentrics 22 and 33 are timed to lift their respective feed-dogs l3 and 25 simultaneously.

Theupstanding auxiliary feed-bar 25 is formed with an arcuate slot 34 which is freely entered by a stud-pin 35 on the forward end of the link 36, Fig. 2, which is disposed at the outer side of the posts P, I", and at its rearward end is connected to the fulcrum-pin A5 for the main feed-bar M. The arcuate slot 3 is concentric with the pin l5 at the beginning of the feed-stroke of the parts. The link 3.6 is disposed at the end of the sewing machine bed I and is in position for ready appli-- cation to and manipulation by the treadle-controlled mechanism to be described.

Secured to the bearing bracket 9 by means of the screw 12 and a key-piece 38 is the bracket 39 to which is fulcrumed at the point 48 adjacent the auxiliary feed-bar 26, the treadle-controlled lever 4| disposed substantially, horizontally at the outer side of the link 36 and having fixed to the inside face thereof the horizontally slotted block 42 embracing the roller-stud 31 on the outer side of the link 36. A down-pull on the treadlechain 43 connected to the rear end of the lever 4| adjacent the feed-rocker l6 lowers the front end of the link 36 in the arcuate slot 34 of the auxiliary feed-bar and increases the stroke of the auxiliary feed-dog 25 to effect a fulling in of i the work.

The lever 4| has a downwardly extending arm 44 adjacent its fulcrum 40 and this arm carries an adjustable stop screw 45 arranged to engage the bearing bracket 9, Fig. 3, and limit the recovery motion of the lever 4| under the influence of the recovery spring 46, when the pull on the treadle-chain is relieved; the spring 46 being connected at one end to the arm 44 and at its other end to a pin 41 on the bracket 39.

To hold the lever 4| closely alongside the bracket 39, the latter is formed with an arcuate slot 48 through which freely passes the screw 49 tight in the lever 4|.

The down-motion of the lever 4| may be arrested at any desired predetermined point by means of a stop-plate 50 ,held in any desired position of vertical adjustment by means of screws 5| passing through the vertical slot, 52 in the stop-plate 50.

From-the foregoing it will be seen that the auxiliary feeding mechanism comprises a simple addition to the conventional main feeding mechanism of the machine and that it is instantly responsive to the will of the operator to either full in the work or feed it to the same extent as the main feed mechanism. Due to the exposed position of the treadle-controlled lever 4| and its supporting bracket 39, these parts are readily applied to or removed from the machine, without disturbance of the feeding mechanism proper.

In the operation of the mechanism, the endwise movable link 36, which connects the main feed-bar l4 and feed-rocker Hi to the slotted auxiliary feed-bar 26, is guided in its movements by the slotted guide-block 42 on the treadle-controlled lever 4|. The slotted auxiliary feed-bar rises and falls relatively to the stud-screw 35 at the forward end of the link 36 which transmits the rocking feed-and-return movements of the feed-rocker Hi to the auxiliary feed-bar 26.

Having thus set forth the nature of the invention, what I claim herein is:

1. In a sewing machine, a main shaft, main and auxiliary feeding mechanisms including main and auxiliary feed-bars with separate. and independent supporting means therefor at opposite sides of said main shaft, one of said feed-bars having an arcuate slot, a link connection between said feed-bars, means at one end of said link freely received in said arcuate slot, and means for guiding said link. r

2. In a sewing machine, a main shaft, main and auxiliary feeding mechanisms including main and auxiliary feed-bars with separate and independent supporting means therefor at opposite sides of said main shaft, one of said feed-bars having an arcuate slot, a link connection between said feed-bars, means at one end of said link freely received in said arcuate slot, and manually controlled means for positioning and guiding said link.

3. In a sewing machine, a main shaft, main and auxiliary feeding mechanisms including main and auxiliary feed-bars with separate and independent supporting means therefor at opposite sides of said main shaft, one of said feed-bars having an arcuate slot, a link connection between said feed-bars, means at one end of said link freely received in said arcuate slot, and a manually controlled lever connected to said link intermediate the ends of the latter for operatively supporting and guiding the same.

4. A sewing machine having a standard, a bed, and a main shaft extending lengthwise of and journaled on said bed, throat-plate supporting means rising from said bed, a throat-plate mounted on said supporting means and formed with feed-dog slots, a main feed-bar at the inner side of said throat-plate supporting means nearer the sewing machine frame standard, a main feeddog carried by said main feed-bar, a feed-rocker to which said main feed-bar is pivotally connected, a feed-advance eccentric on the main shaft connected to actuate said feed-rocker, a main feed-lift eccentric on the main shaft connected to said main feed-bar, an upstanding slotted auxiliary feed-bar at the outer side of said supporting means more remote from the frame-standard, an auxiliary feed-lift eccentric on the main shaft and mechanism for imparting rising and falling movements to said auxiliary feed-bar, a link connection at the outer side of said supporting means between the slotted portion'of said auxiliary feed-bar and said main feed-rocker, and treadlecontrolled mechanism at the outer side of said link for shifting the latter relative to said auxiliary feed-bar.

5. A sewing machine having a standard, a bed, and a main shaft extending lengthwise of and journaled on said bed, throat-plate supporting means rising from said bed, a throat-plate mounted on said supporting means and formed with feed-dog slots, a main feed-bar at the inner side of said throat-plate supporting means nearer the sewing machine frame standard, a main feeddog carried by said main feed-bar, a feed-rocker to which said main feed-bar is pivotally connected, a feed-advance eccentric on the main shaft connected to actuate said feed-rocker, a main feed-lift eccentric on the main shaft connected to said main feed-bar, an upstanding slotted auxiliary feed-bar at the outer side of said supporting means more remote from the frame-standard, an auxiliary-feed-lift eccentric on the main shaft and mechanism for imparting rising and falling movements to said auxiliary feed-bar, a link connection at the outer side of said supportingmeans between the slotted portion of said auxiliary feed-bar and said main feed-rocker, treadle-controlled mechanism at the outer side of said link for shifting the latter relative to said auxiliary feed-bar, said mechanism comprising aspring-biased lever disposed substantially horizontally alongside said link and connected to the latter, said lever having 'a fixed fulcrum adjacent said auxiliary feed-bar and a free end disposed rearwardly of said fixed fulcrum and adjacent said feed-rocker.

6. In a sewing machine, a main shaft, a main feed-rocker in rear of said main shaft, a main feed-bar connected to said feed-rocker, a main feed-eccentric on said main-shaft and connections for operating said main feed-rocker, a main feed-lift eccentric on said main shaft for imparting rising and falling movements to said main feed-bar, an auxiliary feed-lift rock-shaft disposed in front of said main shaft, an auxiliary feed-lift eccentric on said main shaft connected to actuate said rock-shaft, a crank-arm on said rock-shaft, an upstanding auxiliary feed-bar carried at its lower end by said crank-arm and formed with a slot, a direct link connection between the slotted portion of said auxiliary feedbar and said main feed-rocker, and manually controlled means for shifting one end of said link along said slot to vary the amplitude of motion imparted to the auxiliary feed-bar by said feedrocker, without stopping the machine.

7. The combination with a sewing machine bed and main feeding mechanism carried thereby and including a main feed-rocker, of auxiliary feeding mechanism including an auxiliary feeddog, a slotted auxiliary feed-bar, a direct linkconnection between the main feed-rocker and slotted auxiliary feed-bar, and means for shifting said link relative to said slotted auxiliary feed-bar comprising a treadle-controlled lever disposed alongside said link, a bracket on which said lever is fulcrumed at a point remote from said feed-rocker, and a connection between said link and treadle-controlled lever.

8. In a sewing machine, a bed casting a main shaft journaled in said bed casting, a bearing" block for one extreme end of the main shaft detachably mounted on said bed-casting, main and auxiliary feeding mechanisms driven by said main shaft, and treadle-controlled means for varying the feeding action of said auxiliary feeding mechanism comprising, a supporting bracket fixedly mounted on said detachable bearing block, and a treadle-controlled spring-biased lever fulcrumed on said bracket and connected to said auxiliary feeding mechanism.

9. In a sewing machine, a rectangular bed, a main shaft journaled lengthwise of said bed, main feeding mechanism including a main feedrocker fulcrumed on said bed in rear of the main shaft, a main feed-bar fulcrumed at its rear end on said feed-rocker, a main feed-dog mounted at the forward end of said main feed-bar, a slotted auxiliary feed-bar disposed in front of said main shaft, means for raising and lowering said auxiliary feed-bar, a link connected at its rear end to said main feed-rocker and shiftably connected at its front end to said slotted auxiliary feed-bar, a treadle-controlled lever disposed alongside said link and fulcrumed at its front end at a fixed point in front of the main shaft and interconnecting means between the ends of said lever and link.

10. In a. sewing machine, a main shaft, a main four-motion feeding mechanism, an auxiliary four-motion feeding mechanism, said mechanisms including substantially horizontal main and upstanding auxiliary feed-bars respectively supported independently of one another in rear and in front of said main shaft, a link pivotally connected at its rear end to said main feeding mechanism and at its front end freely connected to said auxiliary feed-bar to transmit feed-andreturn movements to the latter, a treadle-controlled lever having a fixed fulcrum, and a connection between said treadle-controlled lever and said link for supporting and guiding the latter in its endwise movements.

ANDREW B. CLAYTON.