US3054159A - Combined tenter clip for cloth tentering devices - Google Patents

Description

G. MCBHRING Sept. 18, 1962 COMBINED TENTER CLIP FOR CLOTH TENTERING DEVICES Filed March 11, 1960 s Sheets-Sheet 1 Fig. 1

Sept. 18, 1962 G. MCjHRING 3,054,159

COMBINED TENTER CLIP FOR CLOTH TENTERING DEVICES Filed. March 11, 1960 3 Sheets-Sheet 2 Se t. 18, 1962 G. MOHRING 3,054,159

COMBINED TENTER CLIP FOR CLOTH TENTERING DEVICES Filed March 11, 1960 3 Sheets-Sheet 3 United States Patent 3,054,159 COMBINED TENTER CLIP FOR CLOTH TENTERING DEVICES Gustav Miihring, Salzmannweg 3, Stuttgart, Germany Filed Mar. 11, 1960, Ser. No. 14,464 Claims priority, application Germany Mar. 13, 1959 1 Claim. (Cl. 2662) The present invention relates to improvements in tentering apparatus, and more particularly to an automatically operated tenter clip. A plurality of such clips is mounted on a movable chain and comprises pivotable means for gripping a fabric or other material while the latter is subjected to a tenten'ng or heat treatment.

In a prior device of this kind, as disclosed in the United States Patent No. 2,350,961 to A.' F. Haskins, each tenter clip is provided with a pivotable hammerl ike gripping jaw terminating in a gripping edge, a spring for holding the jaw in the open position, and a pair ofelectromagnets for closing the-jaw. These electromagnets when energized have to-be of a strength so as to overcome the force of the spring and to press the jaw upon the material with such a force that it will clamp the same securely during the tentering operation. When the material is thereafter to be released, the electromagnets on each tenter clip have to be de-energized so that the gripping jaw can then again be opened by its spring. A mechanism of this type is obviously very complicated and expensive.

Although the present invention also involves the use of magnets, these magnets are to be used to accomplish an object entirely different from that of the mentioned patent. The magnets of this invention are not to be applied to tenter clips with hammer-like gripping jaws but to tenter clips provided with pivotable needle bars, either alone or in combination with clips which are provided with feeler devices. Such needle bars and clips are usually held in their end positions either merely by.

their own weight or by special spring catches.

It has now been found that in modern machines, with greatly increased chain speeds and greatly increased tem peratures during the heat treatment of the fabrics, it is necessary to secure the needle bars and clips more firmly in their respective end positions. These high speeds result in considerable vibrations as well as centrifugal forces at the reversing points of the chain so that the gripping means can no longer be safely held in engagement with their end stops merely by their own weight. Even if such an engagement by gravity is to be made more secure by spring catches, such securernent will soon become inadequate since the high temperatures applied during the heat treatment of the materials will soon impair the resilience of the springs and render them obsoletev In order to overcome these difficulties, the present invention provides the gripping means with additional locking elements which are adapted to secure the gripping means in their respective end positions Without exerting any additional gripping action upon the material to be treated. According to the invention, these locking elements are provided in the form of permanent magnets which do not require any special means for energization and deenergization.

These and other objects, features, and advantages of the present invention will become more apparent from the following detailed description thereof, particularly when the same is read with reference to the accompanying drawings, in which FIGURE 1 shows a top plan view of two adjacent tenter clips according to the invention which, togther with a plurality of the same kind, are connected to an endless chain;

FIGURE 2 shows a side view of a part of one of the "ice needle-bar bracket in the operative position and a clip bracket in the inoperative position;

FIGURE 3 shows another side view of the same tenter clip, with the pivotable needle-bar bracket in the inoperative position and the clip bracket in the operative position;

FIGURE 4 shows a side view of a tener clip according to a modification of the invention, with a pivotable needle-bar bracket in the operative position and the clip bracket in the inoperative position; while FIGURE 5 shows another side view of the tenter clip according to FIGURE 4, with the pivotable needle-bar bracket in the inoperative position but at the same time serving as a cloth-supporting surface, and with the clip bracket in the operative position.

A general view of a tentering apparatus which is somewhat similar to that of the invention is shown in FIG- URE 1 of the above-mentioned United States Patent No. 2,350,961 and a drawing with a similar view of the entire apparatus according to the invention is therefore considered unnecessary as the distinguishing differences between the two types of apparatus would hardly benoticeable therein.

- FIGURE 1 of the present invention illustrates the manner in which two of many adjacent tenter clips 1 are connected to an endless chain 21 and are guided by rollers 22 within a channel of a continuous rail 23. As shown in FIGURES 2 and 3, the body 1 of each tenter clip has a lower projecting arm 2 provided with a needlebar bracket 3 in the form of a two-arm lever pivotably secured to the outer end thereof on a pivot pin 24.

Arm 2 has mounted therein near its outer end a permanent magnet 4. Needle-bar bracket 3 has a lower arm 5 which, in the operative position of the bracket as shown in FIGURE 2, engages the lower side of arm 2 and lies against magnet 4. Needle-bar bracket 3 is further provided on its upper arm with a flat portion 6 which, in the inoperative position as shown in FIGURE 3, engages the upper side arm of 2 and likewise abuts against magnet 4. Arm 2 therefore serves as an end stop to determine the operative as well as the inoperative to be tentered is hooked upon the needles of needble bar 8 on bracket 3. If, however, during their return travel on the endless chain 21 the tenter clips 1 no longer carry any cloth on the needles, the needle-bar brackets must still remain in the upright position, as shown in FIGURE 2. Although ordinarily the weight of the arm of bracket 3 carrying needle bar 8 will be sufficient to maintain the bracket in this position, its being locked therein by magnet 4 will absolutely insure this.

Tenter clip 1 also comprises an upper projecting arm 11 with a second gripping element in the form of an upper clip bracket 13 which likewise forms a two-arm lever and is pivotably mounted on the end of arm 11 on a pivot pin 25. This bracket 13 carries on its lower heavier arm a cloth gripping plate 9 which, due to the weight of this arm, rests on the cloth-supporting surface 10, provided the edge of the cloth 7 has not been pushed so far upon this surface that a feeler roller 15 which is mounted on bracket 13 will rest on the cloth and thereby prevent the gripping plate 9 from engaging therewith. Gripping plate 9 can therefore not engage with the cloth 7 and clamp the same so firmly upon the supporting surface 10 that a further withdrawal .of the cloth will be impos- Patented .Sept. 18, 1962 sible until the cloth has first been slightly withdrawn from the surface 10. Consequently, the feeler roller 15 will disengage from the edge of the cloth and drop into a recess in the supporting surface 10 and thereby permit bracket 13 to pivot forwardly, that is, toward the left of FIGURE 3, and thus wedge the gripping plate against the cloth.

In order to move the clip bracket 13 from the operative position, as shown in FIGURE 3, to the inoperative position, as shown in FIGURE 2, the machine is provided with a suitable guide rail, not shown. During its movement on chain 21, the lower bracket 13 will slide along this guide rail and will thereby be pivoted counterclockwise until its flat surface 6 engages with the lower side of arm 11. After disengaging from the mentioned rail, bracket 13 which consists of magnetizable material will, without any additional spring action, be held arrested in this pivoted position by the attractive force of a permanent magnet 12 which is embedded in arm 11 opposite to the flat surface 6. The bracket 13 will remain in that position until its other arm 14 will engage with and slide along another guide rail, not shown, which will force that arm downwardly and thereby pull the lower bracket 13 off the permanent magnet 12 so that it can then pivot downwardly by its own gravity.

In the modified embodiment of the invention as illustrated in FIGURES 4 and 5, the lower projecting arm 2 on the body of tenter clip 1 carries on its end, and pivotable about a pin 24, a different kind of needle-bar bracket 16 than that shown in FIGURES 2 and 3. case the two-arm bracket 16 consists of nonmagnetic material, the arm thereof contains a magnetizable insert 17 at the point which is adapted to engage the lower side of the permanent magnet 4. Similarly, the other arm of bracket 16 which carries the needle bar 8 is provided with an insert 17 of magnetizable material which in the other end position, as illustrated in FIGURE 5, engages with the projecting upper end of magnet 4. Bracket 16 will therefore be securely arrested by magnet 4 in either of its two end positions.

The embodiment according to FIGURES 4 and 5 further differs from that according to FIGURES 2 and 3 by the fact that the cloth-supporting surface is not disposed directly on the body 1 of the tenter clip but on the back of the arm of bracket 16 which carries the needle bar 8, and in such a position that, when this arm is pivoted to the position as shown in FIGURE 5, the cloth-supporting surface 10 will be disposed at the same level at which the surface of needle bar 8 is located when it is pivoted to the position as shown in FIGURE 4. The cloth-supporting surface 10 is then operatively associated with the clip bracket 13 in the same manner as previously described with reference to FIGURES 2 and 3. However, since bracket 13 according to the embodiment shown in FIGURES 4 and 5 also consists of nonmagnetic Since in this material, this bracket is likewise provided with an insert 18 of magnetizable material in a lateral projection thereof. Through this insert 18, bracket 13 will act as an armature of the permanent magnet 12 which is mounted in arm 11 on the clip body 1, and will be so firmly attracted by the magnet that it will be securely locked in the position according to FIGURE 4 Without requiring any additional locking means.

The permanent magnets may also be mounted on the pivotable brackets instead of on the fixed arms on the clip bodies, in which event these arms or the magnetizable inserts therein would form the armatures of these magnets.

Although my invention has been illustrated and described with reference to the preferred embodiments thereof, I wish to have it understood that it is in no way limited to the details of such embodiments, but is capable of numerous modifications within the scope of the appended claim.

Having thus fully disclosed my invention, what I claim 1s:

A tenter clip comprising a body having a pair of projecting arms and adapted to be connected to a movable endless chain, each of said body arms having a pair of stop surfaces at opposite sides thereof, means pivotably secured to the end of each body arm for gripping a fabric to be tentered and pivotably movable in opposite directions between two limit positions defined by said stop surfaces, said gripping means constituting levers each having two arms, each of said levers having a pair of stop engaging surfaces each adapted to engage a corresponding one of said stop surfaces on the corresponding body arm when said lever is pivoted in one direction or the other, and a permanent magnet mounted on each body arm to be effective within the area of both stop surfaces of each body arm and forming an insert in each body arm near said end thereof for maintaining the corresponding gripping means when in operative position in engagement with one of said body arm stop surfaces without exerting any force upon said fabric, said magnets being effective at each of said sides of each of the body arms to hold said arms of the corresponding lever when moved into engagement with their corresponding stop surfaces on the respective sides of each said body arm.

References Cited in the file of this patent UNITED STATES PATENTS 1,119,824 Hayward Dec. 8, 1914 2,350,961 Haskins June 6, 1944 2,945,280 Liebert July 19, 1960 FOREIGN PATENTS 1,186,827 France Mar. 2, 1959 81 Great Britain of 1900

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