US2599714A - Swinging flap for tenter-frame clips - Google Patents

Description

June 10, 1952 K. KLOPFER L swrmcmc FLAP FOR TENTER-FRAME CLIPS Filed Dec. 21, 1950 2 SHEETSSHEET l INVENTOR. KA EL KLOPFEE. BY

6M5 W A ATTORNEYS.

June 10, 1952 K. KLOPFER SWINGING FLAP FOR TENTER-FRAME CLIPS 2 SHEETS-SHEET 2 Filed Dec. 21, 1950 INVENTOR.

w 35 KARL. KLoFF-ER.

7 ATTOE/VEKE.

Patented June 1952 SWIN GIN G FLAP FOR TENTER-FRAME CLIPS Karl Klopfer, Vogelsberg, Uzwil, Switzerland, as-

signor to Heberlein Patent Corporation, New York, N. Y., a corporation of New York Application December 21, 1950, Serial No. 202,029 In Switzerland February 11, 1950 This invention relates to tenter-frame clips, of the swinging flap type, and more especially to such swinging flaps for use in tenter-frame clips.

For the tensing of fabrics in tenter frames there are used in the textile industry tenter frames which have clips that are arranged along the tenter frame inchain form on a chain conveyor. The relatively stationary clips comprise a bed plate and a movable cooperating flap. The fabric web that is to be tensed is drawn through between the fixed bed plate and the movable flap, With concomitant lifting of the latter, and the flap is then lowered and pressed down upon the fabric web, as by a counter weight. The fabric web that is thus tensed now tries to turn the swingingly pivoted flap in the direction of the traction, in consequence whereof, however, the latter is only pressed all the more forcibly against the bed plate, since the distance of the axis of rotation of the flap from the bed plate is less than the distance from the axis to the edge of the flap.

Very great demands are made on such tenterframe clips, since the fabric webs held tensed by them often travel through drying chambers which have a temperature of over 150 C. The tenter-frame clips are therefore constantly subjected to comparatively great differences of temperature, which causes its parts constantly to undergo considerable expansions and contractions, in consequence whereof a faultless and firm support of the fabric web is easily rendered doubtful. Furthermore, the least inexactitude in the parallelism between the pressure edge of the flap and the bed plate causes the fabric web to be grasped only partially and accordingly pulls askew or tears. Therefore the manufacturing tolerances of the known tenter-frame clips must be kept very narrow, which has a detrimental effeet in the high price of these parts. In spite of the exact manufacture and close tolerances the deformation in consequence of heat cannot be entirely compensated, so that even though the clip has taken hold faultlessly in the cold state, that is by no means any longer the case in the hot state. A further disadvantage of the known clips lies in the fact that in case of a slight wear of the pressure edge of the flap the latter has to be refinished to insure at least normal parallelism. Since the difference between the distance of the axis of rotation of the flap from the bed plate and the distance from said axis to the edge of the flap is naturally comparatively small, only slight refinishing is possible. Thereafter the flaps of such devices have to be replaced.

8 Claims. (Cl. 2662) In accordance with this invention all these disadvantages are obviated by providing a clip having a swinging flap which comprises at least two movably arranged pressure blade members and means for mounting them so that grippin pressure of respectively individual blades will be equalized and intimate gripping contact enhanced.

An object of this invention is to provide a clip free from the disadvantages above referred to and possessing the desired advantages.

Another object is to provide a swinging fiap which may be used in clips of this type to provide the desired advantages.

Further objects, features and advantages of the invention will more fully appear from the detailed description given below taken. in conjunction with the accompanying drawings, illustrating by way of example preferred embodiments of the invention and in which:

Fig. 1 is a side view of tenter-frame clip, embodying my invention, viewed from the side of entrance of the fabric;

Fig. 2 is a top plan view of the device shown in Fig. 1;

Fig. 3 is a sectional view taken along line 3-3 of Fig. 1;

Fig. 4 is a longitudinal sectional view taken on line 4-4 of Fig. 3, showing further details of the flap with the plurality of blades in equalized clamping position and schematically showing an associated part of the clip body;

Fig. 5 is a cross-sectional view taken at line 5-5 of Fig. 4;

Figs. 6 and 7 are views similar to Fig. 4 showing the blade parts in different positions for illustration of the mode of operation of the pressure blades; and

Fig. 8 is a View similar to Fig. 4 but showing a modified embodiment of the invention wherein four pressure blades are used.

In Fig. l, l signifies the clip body. For the forming of a chain with additional clip bodies there are provided on one end an eye 2 having a bore and at the other end two eyes 3 and 4, respectively, equipped with vertically aligned bores. In the mounting of the tenter-frame clips on the tenter frame the eye 2 is introduced between the eyes 311 and 4 a of one adjacent clip la (provided to the left of the tenter-frame clip I) and a pivot bolt is introduced through the three bores that are situated above one another; and the eye 2c of another adjacent clip lb (provided on the right of clip I) is similarly secured to the edges 3-4 of clip I On the part I there is provided a horizontally situated bed plate 5 upon which lies the edge of a fabric web that is to be stretched. The bed plate 5 lies on a correspondingly shaped support table 6, which forms one piece with the eyes 2 to d. From the rear of the table 6 two bearing yokes 1 and 8 extend upwardly and then toward the front in substantial parallelism one to the other. On their free ends I and 8' they are provided with aligned bores which serve as the bearing-supports for a flap axle 9 whose axis is substantially parallel to the bed plate 5. On the axle 9 a swinging flap I2 is rotatably supported by means of two bearings ID and H, respectively. The swinging flap l2 and the bed plate 5, in order to prevent rusting, are preferably made of bronze or rustless steel, but all the other parts, forming the body of the described contrivance may be made of bronze or of malleable pig iron. The flap axle 9, on its part, is made of steel or hard copper. On its rear'side the swinging flap [2 has a handle 13 (Figs. 2-3), :by means of which it is steered through the fabric web at the locking. Since this handle is directed downward, the bed plate 5 and the supporttable 6 have an aperture 14.

:Now in accordance with the invention the swinging flap [2 is not provided with a unitary blade therewith, but, as is more fully shown in 1 Fig. 4, is provided with a cavity l5 providing a slot in which a plurality of pressure blades, such as 16 and ll, are movably supported. The latter each have two longitudinally spaced vertically .elongated holes [8, ISland. 20, 2|, respectively,

through each of which respective pins 22-25 project, which pins are firmly supported in the A body of the swinging flap. The pressure blades l6, H, as a result of this expedient, are extensively movable in a direction up and down and are permitted a rocking motion, but are secured by the pins 22-25 from dropping out of the cavity l5 and are restrained ina lengthwise direc- 1 tion. Ontheir lower gripping edges the pressure blades I6, I! are obliquely ground, as is apparent from Figs. 3 and 5, while on their upper side they each have raised fulcrum points, preferably in the form of semi-circular elevations 26 and 21, respectively, upon which a fulcrum bar serving as'a pressure equalization crossbar 23 lies. The

latter is secured by two pins 29 and 39, respectively, against endwise displacement, but is otherwise supported in a completely free manner in the cavity-l5. The position of the bar 28 in re- ,lation to the pressure blades l 6, I! is fixed by an adjustment screw 31. By means of this arrangement both-pressure blades always act upon the clamped fabric with the same pressure independently of .the unevenness of the fabric that is to be clamped (indicated as F), since by way of the pressureequalization crossbar 28 a compensation .of the pressure takes place in any position of the pressure blades. Also, the rocking movement of the blades about their fulcrum points 2E21 enhances the gripping action of the blades. In Fig.

6.,the tenter-frame clip is shown with the blades in aposition illustrative of the position assumed when a clampedpiece of fabric F is first engaged by one pressure blade 16 only and the other blade I'Lisfree from engagement with the fabric; In

.thiscase the pressure blade [6 is raised solely to the extent of the thickness of the material that is tobe clamped, for instance of. a fabric web F, while the, pressure blade I"! remains lying on the bed plate 5. Owing to the pressure equalization crossbar '28, however, the pressure blade l 6 presses .againstthe. material: that is to be clamped with ment by pins such as 4!. of thebar 49 correspondingly engages the oppoturned somewhat in the counter-clockwise direction about its fulcrum point 26, while the pressure blade I! has turned to the extent of a similar amount in the clockwise direction about its fulcrum point 27. Both the pressure blades again exert an equally great application pressure upon the clamped material throughout the full length (the blades.

If the material that is to be clamped is particularly uneven, the swinging flap may also be equipped with a greater number of pressure blades. For example, in Fig, 8 a swinging flap having four pressure blades 32-85, inclusive, is illustrated. Certain features identical, or nearly so, to the device previously described will be designated with corresponding reference numerals with the prime suffix added. The blades 32-35 are similarly secured for limited movement in the cavity :5 by pins, such as 36,

which pass throughvertically elongated holes,

such as 31. In the middle of the upper edge of each pressure blade a semicircular elevation, such as 38, is similarly arranged. A supplementary fulcrum bar --39 lies upon elevations, such as 38, provided on one set of pressure blades 32 and -.33 and the bar 39 is secured against lateral displacement by a pair of spaced pins such as ll. The top of the fulcrum bar 39 is provided intermediate its ends with a knife edge which engages near one end amain fulcrum bar or pressure equalizing cross-bar 52. Likewisea similar supplementary fulcrum bar 4!) lies upon like elevations on the other set of pressure blades as and, 35 and is secured against lateral displace- The upper knife edge site end of the main fulcrum bar 42 which is prevented from v endwise displacement by pins, such. as-43. The common pressure equalization crossbar 42 is-likewise shaped with a knife-edge at the top and can press with this part against the adjustment; screw 3|. it. can readilyiibe realized that owing to the three pressure .equalizaticn Crossbars 39, 4B, and lfl each individual pressureblade under all-normal circumstances, i. e., as longas the unevennesses of the material that is'to be clamped. do .not exceed a certain admissible amount, alwayspresses withthe same force against the clamped material and the individual blades engage the material substantially throughout their lengths. vAs a rule, however, such an extensive subdivision of the pressure blades is not necessary. In practice, a subdivision into two pressure blades has proved to be sufficient.

From the described movable arrangement of the pressure blades there results the advantage that the clips no longer have to be manufactured with excessively great tolerances. Even incase of pronouncedly bad support of the flap axle 9 in the two bearing yokes 1,8 or in case of excessive play between the bearings in the-bearing eyes-ii), ll of the swinging-flap and the flap axle- 9, the contrivance works entirely satisfactorily. The flap axle afurthermore needs to be mounted only approximately parallel to the bed plate 5. Deformations in consequence of great differences of temperature remain ineffective. In case of wear of the pressure blades these are no longer refinished, but newly adjusted by turning of the adjustment screw 3|. Tests have shown that with the swinging flap in accordance with the invention not only all types of fabrics, but even metal foils of only several hundredths of a millimeter thickness can be clamped altogether faultlessly.

It will be obvious to those skilled in the art that instead of providing fulcrum edges on the upper surfaces of bars 28, 39, 4B, and 42 the limited zones of fulcrum engagement may be provided on the other members or portions engaged by these surfaces; and similarly, instead of providing the fulcrum points such as 26, 21, and 38 on the upper edges of the blades limited zones of contact may be provided by protuberances formed on the lower edges of the fulcrum bars at points where engagement with the blades is desired. ihe alternatives are so well understood as to require no illustration. Likewise where reference is made to fulcrum, or pivot points it is understood that this term is used in its general, and not in its restricted, sense as referring to a limited zone of contact-which preferably approaches a line contact.

Having thus described my invention with particularity with reference to presently preferred embodiments thereof it will be obvious to those skilled in the art, after understanding my invention, that various changes and modifications may be made therein without departing from the spirit and scope of my invention, and I aim in the appended claims to cover such changes and modifications as fall within the scope of the invention.

What I claim is:

1. A swinging flap for use in a tenter-frame clip comprising a body member, a plurality of blade members supported by said body and having engaging edges extending beyond the lower edge of said body, said blades being disposed in substantially coplanar relationship and supported for limited individual movement relative to said body in the plane of said blades, and pressure equalizing means positioned for joint engagement with said body and blades for transmitting transverse movement of one of said blades to another of said blades.

2. A swinging flap for use in a tenter-frame clip comprising a body member, a plurality of blade members supported by said body and having engaging edges extending beyond the lower edge of said body, said blades being disposed in substantially coplanar relationship and supported for limited individual movement in a direction transverse their edges and angularly relative to said body in the plane of said blades, and pressure equalizing means positioned for engagement with respective blades at localized areas intermediate their oppositely disposed ends and positioned for engagement with a portion integrally rigid with said body at a point disposed substantially centrally lengthwise of said plurality of blades for transmitting transverse movement of one of said blades to another of said blades.

3. A swinging fiap for use in a tenter-frame clip comprising a body member adapted to be supported about a pivotal axis from a clip base and having a lower end provided with a slot extending in a direction substantially parallel to said axis, a plurality of blade members slidably disposed in said slot in tandem arrangement and having engaging edges movable outwardly beyond said slot, means individually restraining said blades for limited movement toward and away from said axis and for limited angular movement, a fulcrum bar movably disposed in said slot above said blades, and stops secured to said body member and disposed adjacent respectively opposite ends of said bar for limiting its endwise movement, said bar bein positioned for abutting engagement intermediate its ends with a portion provided on said body and about which said bar is adapted to pivot, the oppositely disposed ends of said bar being in force-transmitting connection with respectively corresponding oppositely disposed blades.

4. A swingin flap for use in a tenter-frame clip comprising a fiap body member having a cavity providing a blade slot extending in a direction lengthwise of said axis and opening outwardly through the lower edge of said flap body, a plurality of blades disposed in tandem within said slot with their lower edges extendable therethrough for gripping engagement, said blades each having a pair of vertically elongated holes spaced apart in a direction lengthwise of said blade, supporting pins passing through said holes and seated in said flap body, said blades each having an upwardly extending raised portion intermediate its ends providing a fulcrum 'point of limited area, a fulcrum bar movably disposed in said cavity above said blades with its opposite ends respectively positioned for engagement with said fulcrum points and being positioned for engagement intermediate its ends with a fulcrum about which said bar is pivotally movable, and means for maintaining said bar in operative engagement with said fulcrum points.

5. A swinging flap for use in a tenter-frame clip comprising a flap body member provided on its upper end with a pair of laterally spaced lugs having axially aligned bores for receiving an axle serving to pivotally support said flap from a clip body, said flap body having a cavity providing a blade slot extending in a direction lengthwise of said axle and opening outwardly through the lower edge of said flap body, a plurality of blades disposed in tandem within said slot with their lower edges extendable therethrough for gripping engagement, said blades each having a pair of vertically elongated holes spaced apart in a direction lengthwise of said blade, supporting pins passing through said holes and seated in said flap body, said blades each having an upwardly extending raised portion intermediate its ends providing a fulcrum point of limited area, a fulcrum bar movably disposed in said cavity above said blades with its opposite ends respective-1y positioned for engagement with said fulcrum points and being positioned for engagement intermediate its ends with a fulcrum about which said bar is pivotally movable, and means for maintaining said bar in operative engagement with said fulcrum points.

6. A swinging flap for use in a tenter-frame clip comprising a body member adapted to be supported about a pivotal axis from a clip base and having a lower end provided with a slot extending in a direction substantially parallel to said axis, a plurality of oppositely positioned blade members slidably disposed in said slot in tandem arrangement and having engaging edges movable outwardly beyond said slot, means individually restraining said blades for limited movement toward and away from said axis and for limited angular movement, a fulcrum bar movably disposed in' saidslot: above said blades, said bar 1 2 being disposed with its mid-portion engageable witn a fulcrum provided on said flap theoppositely disposedends of said bar being in body and force-transmitting connection with-respectively corresponding oppositely positioned blades.

TIA-swinging flap-foruse in atenter-frame clip comprising. a body member having an upperend adapted to be supported about a pivotal axis from .a clip base and having a lower end :provided with a slot extending in a direction substantially parallel to'said axis, two -blade members slidably disposed" in said'slot in: tandem arrangementand havingengaging edges disposed substantially in a common plane and movable outwardly beyond tion ofsaid bar, and. said bar having its opposite endsdisposed'for-operable contact with lim- -.ited zones intermediate the ends of respectively corresponding blades.

8.-A swinging flap for use in atenter-frame clip -i.comprising,a body member having an upper end I adapted to be supportedabout a pivotal axis from -aclip-base and having a lower endprovid'edwith aslot extending in a direction substantially parallel to said axis, two sets each comprising two blade members, said blades being slidably disposed in said slot in tandem arrangement and havin engaging edges movable outwardly beyond said slot, means individually restraining said blades 1 for limited movement toward and-away fromsaidaxis and for limited angular movement,

a main fulcrum bar movably disposed in said slot above said blades, said flap body having a fulcrum point engageable by an intermediate portion-of :saidmain bar intermediate its ends for rocking -movement about said fulcrum point, a pair of -supplemental fulcrum bars disposed in said slot between said main bar and respective sets-Jot blades. and being arranged for fulcrum engagement intermediate their ends with respectively corresponding ends of saidmain bar, said supplementalbars having their ends arranged'for con ltactwithlirnited zones intermediate the endsof respective corresponding individual blades, and

,- means for limiting endwise movement of said bars in said slot.

KARL KLOPF'ER.

No references cited.

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