US3631690A

US3631690A - Latch needle knitting machines

Info

Publication number: US3631690A
Application number: US18532A
Authority: US
Inventors: Peter M Findlay; Raymond Henry Phillips
Original assignee: Bentley Engineering Co Ltd
Current assignee: Bentley Engineering Co Ltd
Priority date: 1970-03-11
Filing date: 1970-03-11
Publication date: 1972-01-04
Anticipated expiration: 1989-01-04

Abstract

The latch opener is in the form of a feelerlike member which is pointed and directed laterally of a needle. A wedge-shaped blade is inserted into the bent over point of the feelerlike member and is insulated therefrom. The blade forms an electrical connection by way of a wire upon contacting a latch. Engagement of a needle shank on the opposed side of the feeler member does not create an electrical circuit for stopping the machine. Alternatively the body of the feelerlike member can provide the electrical connection with an errant latch. The point of the feelerlike member is coated with or formed of an electrically insulative material.

Description

United States Patent [72] Inventors PeterM. Findlay [54] LATCH NEEDLE KNITTING MACHINES 6 Claims, 7 Drawing Figs.

[52] U.S. Cl 66/111, 66/165 [51] int. Cl 15/08, D04b 35/18 [50] Field ofSearch 66/157, 165, 111

Primary ExaminerWm. Carter Reynolds Attorney-Kenyon & Kenyon Reilly Carr & Chapin ABSTRACT: The latch opener is in the form of a feelerlike member which is pointed and directed laterally of a needle. A wedge-shaped blade is inserted into the bent over point of the feelerlike member and is insulated therefrom. The blade forms an electrical connection by way of a wire upon contacting a latch. Engagement of a needle shank on the opposed side of the feeler member does not create an electrical circuit for stopping the machine. Alternatively the body of the feelerlike member can provide the electrical connection with an errant latch. The point of the feelerlike member is coated with or formed of an electrically insulative material.

Pmamium 41922 3.631.890

SHEET 1 OF 2 uxye/v-rom PETER MICHAEL Fl ma RAYMOND HENRY PHILLIPS E 4 "OR/YE Y5 LATCH NEEDLE KNITTING MACHINES This invention is for improvements in latch needle knitting machines and is concerned with an improvement in or modification of the invention described and claimed in U.S. Pat. No. 3,397,556 issued Aug. 20, 1968. The said earlier invention is concerned with the provision of a combined latch detector and latch-opening device which at certain times is arranged to detect the presence of a wrongly positioned needle latch and initiate a signal to effect stoppage of the machine, and at other times to operate so as to open closed latches without stopping the machine. The device disclosed as an embodiment of said earlier invention comprises a pointed feelerlike member which is so shaped that it can enter into the small space between a closed latch and the stern of its needle just below the hook and which is so positioned as to be in registry with such space in respect of all needles which are at a predetermined height at the position at which the detector device encounters them. In said earlier device the feelerlike member is electrically energized for its fault-detecting function and when so operating will make electrical contact with a latch not held open by yarn because of a fault and so complete an electric circuit for stopping operation of the machine. When functioning as a latch opener the feeler device has its electrical circuit disconnected so that no electrical impulse will be given when it engages a closed latch specifically for the purpose of opening it.

It has been found in practice that under certain conditions, and particularly with high-speed working, the precise positioning of the feelerlike member of the detector device needed to permit it to perform the functions aforementioned does not enable it when operating as a fault detector to be kept entirely free from risk of being engaged by stem portions of needles immediately below their hooks for example by reason of some needles tending to lean outward to a slight extent. Consequently with the said earlier construction there is in such circumstances a tendency for the machine to be stopped unnecessarily due to contact of the feelerlike member with the needle stems when in fact no faulty latch positioning is present. The invention seeks to reduce or eliminate the tendency for unnecessary stoppage being caused to occur.

In accordance with the invention there is provided in a latch needle knitting machine having a latch opener for performing the two functions of (a) opening the latches and (b) detecting a fault consisting of a misplaced latch, means whereby the latch opener when operating as a fault detector is caused to initiate a signal for effecting stoppage only when the latch opener becomes engaged with a misplaced latch (and not if the latch opener becomes engaged with a needle stem or other part). To this end the latch opener may have only that part of it which can engage with a misplaced latch operative as an electrical contact which is connected in a circuit by means of which stoppage of the machine is initiated.

In a convenient form of construction the latch opener is in the form of a feelerlike member which is pointed and directed laterally of a needle so as to be engageable in the space between a closed latch and the facing portion of the needle stem under the hook and in which an electric contact which is insulated from the remainder of the feelerlike member is positioned on the latch-engaging side only of the feelerlike member. Thus even through the opposite portion of the feelerlike member may engage with a needle stem it will not by so doing complete an electrical circuit for stopping the machine.

A convenient form of construction in accordance with the invention and some modifications thereof are illustrated by way of example in the accompanying drawings and will not be described with reference to the drawings in which FIG. 1 is a perspective view showing the latch opener in working relation to latch needles in a circular knitting machine parts of which are also shown;

FIG. 2 is a side view on a larger scale of the blade of the latch opener;

FIG. 3 is a sectional view on the line IIIIII in FIG. 2;

FIG. 4 is a perspective view of part of a latch opener of modified form;

FIg. 5 is view in cross section taken on the line VV in FIG. 4; and

FIGS. 6 and 7 are perspective views showing other alternative forms of the latch opener.

FIGS. 2 and 3 show a latch control member 1 in accordance with this invention made up of a wedge-shaped blade 1a and a main body part having a substantially right-angled bent over pointed end lb. The blade la is fixed into the bent over pointed end lb of the member 1 by means of a nonconductive fixing adhesive such as ARALDITE," this being necessary in order to insulate the two parts electrically from each other. In this specific embodiment a piece of finely knitted nylon 1d, is nonconductive, is first pushed into slot lc on the underside of the point lb so that it lies around the total internal surface of the slot, and ARALDITE" is then put inside the nylon on the slot followed by the top edge of blade 1a. In this way it is possible to ensure that the adhesive is evenly distributed between the blade and the point of the member, since it percolates easily through the mesh of the knitted nylon, thereby ensuring good electrical insulation between the said parts.

Other ways of making this latch control member are possible. One shown in FIGS. 4 and 5 is to make the main body 11 of the member out of a nonconductive material such as nylon, which, mainly due to the small size of the member, still requires that ARALDITE or another form of adhesive fixer be used to hold the wedge-shaped blade la, but in this in stance the slot itself can locate the blade in position without any lining material.

In another alternative form shown in FIG. 6 the point of a conductive main body of the latch opener 13 is covered with a hard nonconductive material 12 such as aluminum oxide to insulate it from electrical contact with a needle shank. In this form a wedge-type blade is not necessary, the inside face of the uncovered portion of the latch opener 13, adjacent to the tip serving to make electrical contact with a misplaced latch, for fault detection. As the tip of the point is the nearest part of the member to the needles this is the only part liable to touch the needle shank. Therefore the amount of the point covered by the ceramic need only be very small. Because of this it is possible as in FIG. 7 to replace about one-eighth inch of the end of the point of the latch opener 13 with sapphire as at 14 which is nonconductive, or the part 14 may be a metal tip which is insulated from the remainder of the latch detector 13.

The mounting and energization of the latch opener are very similar to those of the aforesaid earlier construction. Thus in the construction illustrated the stern 1e of the latch opener is fixed in a block 5 pivotally mounted on a post 4 secured to a bedplate 15 of the knitting machine. The main arm of the latch opener is insulated from the step 1e by an insulating connecting block 16 and it is yieldably urged into the operative position by a spring 6. Soldered to the back edge of blade la is a wire 3 having an insulating covering which runs along the arm 1 and is connected to the block 5 thence through spring 6, insulated terminal tag 17, wire 18 and electrical circuitry to the stopping means of the machine. Thus, upon contact of the blade with a malfunctioning latch the stopping means will be operated to cut off the electrical supply to the drive of the knitting machine. The terminal tag 17 is mounted and insulated from a post fixed to the bedplate 15 which is shown fixed to a pillar 19.

In FIG. 1 there is shown the general arrangement of the detector device with respect to the needles 2, with the latch opener and control member 1 set for operation at a position in the needle circle where the latches 2a of the needles 2 are normally held open by the knitted loops around the needle stems. The point of the latch control member 1 is set to project into the area just below the hook 2b of a raised needle above the normal latch guard 21 so that the insides of latches not held open will engage and make electrical contact with the wedgeshaped blade Ia to effect a stoppage of the machine. Such setting is effected by means of an adjustable stop screw 20 passing through and screwed into a lug 5a on the block 5 to abut against the post 18a under the action of spring 6.

When the latch control member is used as a latch opener, the point of the member 1 enters just below the hook 2b of the needle and the blade la engages and earns open the needle latches 2a without operating the stopping means.

To enable the latch control member 1 to be operated as a latch opener, provision is for deenergizing the electrical circuit of the blade la or a circuit controller thereby during certain periods of knitting, such as when starting a stocking on bare needles after casting off the previous stocking. Provision is conveniently also made for moving the latch control member out of operative position and away from the needles during certain other periods, such as when transferring to make a turned welt. For the later purpose there may be pivoted on the bottom part of pivot post 4 a flat lever 22 acted on by return spring 24 and cooperating with a depending finger or post 23 on lug 5a of block 5. The lever 22 is coupled to a Bowden cable 25 having its sheath 26 adjustably fixed to a bracket 27 fixed to the bedplate 15. When the Bowden cable 25 is operated from an appropriate control on the knitting machine it will rock the lever 22 clockwise as seen in FIG. 1 to pick up and turn the block 5 so as to rock the latch opener and control member 1 away from the needles 2.

The latch modified latch opener 11 of FIG. 4 can obviously be mounted and connected up exactly as is the latch opener 1 in FIG. 1. The latch openers 13 of FIGS. 6 and 7 can be mounted in like manner but do not need the connecting wire 3 since electrical connection to the block 5 can be made directly through their stems.

What we claim is:

1. In stop motion apparatus of a latch needle knitting machine, the combination comprising a latch opener, means for mounting said latch opener on a machine for cooperation with needle latches thereof for opening any that are at least partly closed, electrical signal-sending means associated with the latch opener to produce a machine stop signal when the latch opener encounters a closed or partly closed latch, and control means for preventing production of such a signal when latch opening without machine stoppage is required, said signal-sending means including a contact means on the latch opener and exposed to engagement with a misplaced latch but incapable of contacting other needle parts, said latch opener being in the form of a feelerlike member which is pointed and for latch-opening and fault-detecting purposes is directed laterally of a needle so as to be engageable in the space between a closed latch and the facing portion of the needle stem under the hook, and including insulating means thereon insulating that part thereof exposedto possible contact with the needle stem electrically from said contact means engageable with a misplaced latch.

2. A combination as claimed in claim 1, wherein the contact means is provided only on that part of the latch opener which can engage with a misplaced latch.

3. A combination as claimed in claim 1 further having a separate electrical contact forming said contact means positioned on the latch-engaging side of said feelerlike member and mounting means for said contact forming said insulating means.

4. A combination as claimed in claim 3 wherein the said electric contact is of wedgelike form to converge towards the pointed end of the feelerlike device and is positioned in a slot therein.

5. A combination as set forth in claim I wherein said pointed end of said feelerlike member which is exposed to possible contact with the stem parts of needles is formed of electrical insulating material.

6. A combination as claimed in claim 1 wherein said pointed end of the feelerlike member which is exposed to possible contact with the stem parts of needles is electrically insulated from the remainder of said feelerlike member.

Claims

1. In stop motion apparatus of a latch needle knitting machine, the combination comprising a latch opener, means for mounting said latch opener on a machine for cooperation with needle latches thereof for opening any that are at least partly closed, electrical signal-sending means associated with the latch opener to produce a machine stop signal when the latch opener encounters a closed or partly closed latch, and control means for preventing production of such a signal when latch opening without machine stoppage is required, said signal-sending means including a contact means on the latch opener and exposed to engagement with a misplaced latch but incapable of contacting other needle parts, said latch opener being in the form of a feelerlike member which is pointed and for latch-opening and fault-detecting purposes is directed laterally of a needle so as to be engageable in the space between a closed latch and the facing portion of the needle stem under the hook, and including insulating means thereon insulating that part thereof exposed to possible contact with the needle stem electrically from said contact means engageable with a misplaced latch.

3. A combination as claimed in claim 1 further having a separate electric contact forming said contact means positioned on the latch-engaging side of said feelerlike member and mounting means for said contact forming said insulating means.

5. A combination as set forth in claim 1 wherein said pointed end of said feelerlike member which is exposed to possible contact with the stem parts of needles is formed of electrical insulating material.