GB1574928A

GB1574928A - Guiding device for an endless apron

Info

Publication number: GB1574928A
Application number: GB4593377A
Authority: GB
Original assignee: NTN Toyo Bearing Co Ltd
Current assignee: NTN Corp
Priority date: 1977-11-04
Filing date: 1977-11-04
Publication date: 1980-09-10

Description

(54) GUIDING DEVICE FOR AN ENDLESS APRON (71) We, NTN TOYO BEARING COMPANY LIMITED, a Japanese Company of No. 25, I-chome, Kyommachibori, Nishi-ku, Osaka-shi, Osaka-fu, Japan, and ZENZABURO TSUKUMO, of Japanese nationality of No.

11-7, Masumi-cho, Ikeda-shi, Osaka-fu, Japan, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention primarily relates to a tensioning and guiding means for endless belt of the like, for example the apron provided in the drafting part of a spinning frame, and applicable to such diverse endless belt feeding mechanisms as are found in, for example, printing machines, duplicators, precision packaging machines, film processors, and the like.

Figure 1 is an illustration showing the typical apron zone of the long apron type drafting device, which comprises such components as a bottom roller BR and a top roller TR, both being disposed on the basis of the roller stand RS, which supports the roller part, and a cradle CR, a tensor bar TB, a tension guide TG pressed by a tension lever TL in the direction of the arrow, a top apron TA and a bottom apron BA, in addition to a weighting arm WA.

However, the performance of the above apron guiding device as regards tightening balancing and guiding the bottom apron, as well as the tensor bar itself has not hitherto been entirely satisfactory.

According to the invention there is provided a tensioning and guiding device for an endless belt or the like, comprising a first slide member slidably mounted between opposed guide surfaces on a support member, a second member movably mounted on the first slide member, spring means for biasing the first and second members, in a direction towards said endless belt or the like, latch means for limiting the range of movement of the first slide member between said guide means and stop means for limiting the range of movement of the second member relative to the first slide member, the end of the second slide member remote from the first slide member having a running surface adapted to bear upon the inner running surface of the endless belt or the like.

The apron guiding device according to this invention has been able to enhance the function of apron guiding devices by eliminating various kinds of drawbacks in the existing ones and, further, adding an automatic apron balancing and tightening means thereto.

Figure 1 is an illustration showing the typical apron zone of the long apron type drafting device in the spinning frame; Figure 2 shows perspective views of the relationship between the base plate, sliding plate, and locking lever, all of which compose the main part of the device according to this invention, (a) showing an open state and (b) a closed one; Figure 3 shows plan views of the same in Figure 2, (a) showing an open state and (b) a closed one; Figure 4 shows changes in position relationship between the spring latch of the sliding base and the locking lever; Figure 5 is a perspective view of the locking lever; Figure 6 shows the relationship between the sliding base and the tension slider; Figure 7 is an illustration showing a modification of the embodiment in Figure 6; Figure 8 is an illustration showing another modification of the embodiment in Figure 6; Figure 9 shows illustration of the device completely assembled according to this invention, (a) showing an open state and (b) a closed one; Figure 10 shows modifications of the embodiments in Figure 9, (a) showing an open state and (b) a closed one; Figure 11 shows a modification of the tension slider; Figure 12 shows a modification of the latch spring; and Figure 13 shows another modification of the latch spring.

In Figures 2 and 3, the sliding base B is equipped with a guiding means AT for automatically balancing, tightening, and guiding the apron at the lower end thereof, and, in addition, integrally incorporating a plate spring S forming a spring latch SL at the middle part of the surface thereof. The sliding base B is held between a pair of slide guides SG slidably only in the direction of Y-Y' line, said slide guides being provided on the surface of the base plate F which is shaped like an angle bar with acute angle and adapted to be a basic surface for movement of said sliding base.

On the other hand, a locking bar L of inverted channel-shaped section and guided through the guide grooves 1, 1 of a pair of said slide guides SG so as to be slidable only in the direction of X-X' axis with right angles to Y-Y' axis, is supported in such a way that it is in contact with the upper surface of said sliding base incorporating the plate spring S and adapted to be capable of, when required, catching and holding the spring latch SL inside the channel-shaped part thereof. Sliding of said locking bar L is controlled within a fixed range by an appropriate device, not shown herein. A pressing spring SP is arranged to press the sliding base B toward the lower side of the drawing and lies between the back of the sliding base B and the surface of the base plate F, in a condition such that both its ends are spring-biased outwards toward the spring-touching surfaces 2 and 3 of both the base plate and the sliding plate respectively; thereby serving as a source of energy for sliding the sliding base B. This pressing means may be replaced, when required, with either pneumatic, hydraulic, magnetic or electric devices.

On the upper surface of the sliding base B, are upwardly protruding flanges 6 and 7, facing towards sides 4 and 5 of the locking bar L, which, accordingly, occupies a position between said protruding flanges 6 and 7 and limits the range of sliding distance of the sliding base B in the direction of Y Y' axis. For example, upward sliding is limited by contact of the lower flange 6 with the locking bar L, and, similarly, downward sliding by contact of the upper flange 7 with the same bar L.

Figures 2-(a) and 3-(a) show the sliding base B protruding from the base plate F, so that the apron engaged thereby is tightened, and the spring latch SL of the plate spring S incorporated in the sliding base B lies outside the channel of the locking bar L.

Figures 2-(b) and 3-(b) show the sliding base B drawn back into the base plate F, thereby compressing the pressing spring SP, so that the apron is loosened, and the spring latch SL lies inside the channel of the locking bar L being withheld by the side 4 of the locking bar L and thereby keeping the sliding base B in the state of withdrawal. A cut-out C is provided in the side 4 of the locking bar L, to allow the spring latch to pass therethrough. In the condition shown in Figure 3-(b) by shifting the locking bar L to the left side of the drawing and aligning the cut-out C of the locking bar L with the spring latch SL, the sliding base B protrudes from the base plate F under the action of the pressing spring SP and exerts the required tension on the apron, as shown in Figures 2-(a) and 3-(a). With the sliding base B protruding from the base plate, the end of the side 4 of the locking bar L is positioned on the line extending from the right side of the spring latch SL, by shifting the locking bar L to the right side by the drawing. In the condition shown in Figure 3 (a), with the sliding base B thrust upward in the direction of Y-Y' axis, against resilience of the pressing spring SP, the spring latch SL passes beneath the bottom end of the side 4 and is withheld therein, as shown in Figure 3-(b).

Figure 4 shows changes in the positional relationship between the locking bar L and the spring latch SL. In the state shown as a where the guiding means is functioning in normal state. If the sliding base B is thrust upward in the direction of Y-Y' axis against the pressing spring SP, the positional relationship between the three, (B), (S, SL) and (L), is changed in turn from (a) to (b) to (c), where the locking bar L is immovable in Y-Y' direction. Upon removal of upward thrust in the condition (c), the spring latch SL slides into the channel and is withheld by the side 4.

For releasing the latch, displacement of the locking bar L as shown in f is necessary. To this end, the locking bar L is shifted to the left by the Figure 3-(b), until the cut-out C of the bar L corresponds to the position of the spring latch SL. In this way, condition as shown in Figure 4-(f) occurs. With this procedure, changes in the positional relationship between the parts, (B) (S, SL) and (L), as shown in Figure 4, namely, two steps of relative displacement as (f)(e)(d) occur, finally returning to the initial condition where the guiding means functions normally. Insofar as the condition continues as shown in Figure 4-(d), the sliding base B does not fail to tighten and guide the apron correctly, offering resistance to compressive force of any nature generated by various types of casual phenomena and exerted upon the pressing spring SP.

Referring to Figure 6, showing a guiding means AT for tightening and guiding the endless apron fitted to the tip of the sliding base B, comprises the sliding base B serving as the foundation of the guiding means; the tension slider TS, U-shaped in section, advancing from the front end of said sliding base B and mounted on the front end portion thereof, and the spring 8 which resiliently protrudes said tension slider TS from the front end portion of the sliding base B and at the same time supports said slider TS against rotation. A circular cut-out 9 is provided at the middle of the front end of said sliding base B as shown in Figure 6 (a) and, on both sides of said cut-out guiding protuberances 10, 10 are provided for guiding and controlling sliding movement of the tension slider TS in the direction of Y Y' axis. As shown in Figure 6, control holes 11, 11 are provided on the tension slider TS and come into enggement with the guiding protuberances 10, 10 when said slider is coupled with the sliding base B. The spring 8 has a circularly curved portion 8' at the middle of the entire length thereof, serving as a center of turning in both directions, and expands both ends 8", 8" in the left and right directions. By means of this construction, the tension slider TS is kept resiliently protruding at all times from the front edge of the sliding base B by the spring 8 and turns around the curved portion 8' of said spring 8 with respect to the sliding base B for balancing, tightening, and guiding the apron.

Referring to Figure 7 showing another modified embodiment of a guiding means AT; a semi-circular protuberance 16 is formed at the middle of the cutout 9 provided on the front edge of the sliding base B, and the curved portion 8"' between the other curved portions 8' and 8' of the spring 8 is adapted to be in contact with the outer edge of said protuberance 16 so that the tension slider TS may turn in both direction around said contact part.

Referring to Figure 8 showing a further modified guiding means AT; sliding movement of the tension slider TS in the direction of Y-Y' axis and repulsion thereof are arranged to depend on the sliding function of the sliding base B itself, and the tension plate TP, U-shaped in section is mounted on the tip of the sliding base B, and adapted for turning about the axis 12, (over a range limited by interengagement between the sides of the tension slider TS and the protruding ends of the sliding base B), for balancing, tightening, and guiding the apron.

Figure 9 shows a type of device for guiding the endless apron to running in the form of triangle, wherein one end of a bracket BKT secured to a frame GR forms the base plate F to be utilized as a foundation to which the sliding base is secured, and the tension slider TS is mounted onto the tip of the sliding base B, i.e., a point where the apron AP changes its running direction. The apron AP is guided in the form of triangle by the three parts, namely, the driving roller R that revolves around the center 01 provided on the bracket BKT secured to the frame GR, the guide roller N revolving around 02, and the balancing and tightening means AT, undergoing tension caused thereby. The guiding portions 13 are provided on both sides of the tip of the sliding base B, so as to move the apron sideways the guidance to a correct path that extends on both sides of a certain center line. The apron guide shown as 14 is in slight contact with the reverse side of the apron AP and separates the apron from the plate F, thereby mitigating acuteness of angle with which the running direction of the apron is changed and preventing the apron from having a permanent curving tendency as well as from sticking of dust to the reverse side thereof.

As shown in Fig. 9-(b), the balancing and tightening means AT at the tip of sliding base B is so constructed as to be received in a cut-out in the base plate F when the sliding base B is drawn back into the base plate F and retained at recess portion.

Therefore, each of a group of aprons that surrounds its respective base plate can freely be handled independent of the respective balancing means, which greatly facilitates maintenance of the balancing means.

In Figure 10, the apron encloses the driving roller R and the sliding base B, including the balancing means AT mounted on the base plate F, which is integrally secured to the frame GR.

Figure 11 shows the tension slider TS to the end of which the guide roller M is secured.

In an arrangement of spring latch on the spring plate S, an additional latch SLP is provided, as shown in Figure 12, opposite to and symmetrical with respect to the spring latch SLM, for limiting the distance of displacement of the device in the direction of Y-Y' axis during the period of normal operation. An experiment was performed with this arrangement, in an attempt to remove the major cause of apron breakage and, as a result, a significant effect has become apparent therefrom.

Further, as shown in Figure 13, latching operation may be performed, in the similar manner as above said by mounting the latch spring SL to the sliding base B and utilizing a hook portion 16 at the tip of the latch spring SL, instead of use of spring plate.

WHAT WE CLAIM IS: 1. A tensioning and guiding device for an endless belt or the like, comprising a first

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. base B, comprises the sliding base B serving as the foundation of the guiding means; the tension slider TS, U-shaped in section, advancing from the front end of said sliding base B and mounted on the front end portion thereof, and the spring 8 which resiliently protrudes said tension slider TS from the front end portion of the sliding base B and at the same time supports said slider TS against rotation. A circular cut-out 9 is provided at the middle of the front end of said sliding base B as shown in Figure 6 (a) and, on both sides of said cut-out guiding protuberances 10, 10 are provided for guiding and controlling sliding movement of the tension slider TS in the direction of Y Y' axis. As shown in Figure 6, control holes 11, 11 are provided on the tension slider TS and come into enggement with the guiding protuberances 10, 10 when said slider is coupled with the sliding base B. The spring 8 has a circularly curved portion 8' at the middle of the entire length thereof, serving as a center of turning in both directions, and expands both ends 8", 8" in the left and right directions. By means of this construction, the tension slider TS is kept resiliently protruding at all times from the front edge of the sliding base B by the spring 8 and turns around the curved portion 8' of said spring 8 with respect to the sliding base B for balancing, tightening, and guiding the apron. Referring to Figure 7 showing another modified embodiment of a guiding means AT; a semi-circular protuberance 16 is formed at the middle of the cutout 9 provided on the front edge of the sliding base B, and the curved portion 8"' between the other curved portions 8' and 8' of the spring 8 is adapted to be in contact with the outer edge of said protuberance 16 so that the tension slider TS may turn in both direction around said contact part. Referring to Figure 8 showing a further modified guiding means AT; sliding movement of the tension slider TS in the direction of Y-Y' axis and repulsion thereof are arranged to depend on the sliding function of the sliding base B itself, and the tension plate TP, U-shaped in section is mounted on the tip of the sliding base B, and adapted for turning about the axis 12, (over a range limited by interengagement between the sides of the tension slider TS and the protruding ends of the sliding base B), for balancing, tightening, and guiding the apron. Figure 9 shows a type of device for guiding the endless apron to running in the form of triangle, wherein one end of a bracket BKT secured to a frame GR forms the base plate F to be utilized as a foundation to which the sliding base is secured, and the tension slider TS is mounted onto the tip of the sliding base B, i.e., a point where the apron AP changes its running direction. The apron AP is guided in the form of triangle by the three parts, namely, the driving roller R that revolves around the center 01 provided on the bracket BKT secured to the frame GR, the guide roller N revolving around 02, and the balancing and tightening means AT, undergoing tension caused thereby. The guiding portions 13 are provided on both sides of the tip of the sliding base B, so as to move the apron sideways the guidance to a correct path that extends on both sides of a certain center line. The apron guide shown as 14 is in slight contact with the reverse side of the apron AP and separates the apron from the plate F, thereby mitigating acuteness of angle with which the running direction of the apron is changed and preventing the apron from having a permanent curving tendency as well as from sticking of dust to the reverse side thereof. As shown in Fig. 9-(b), the balancing and tightening means AT at the tip of sliding base B is so constructed as to be received in a cut-out in the base plate F when the sliding base B is drawn back into the base plate F and retained at recess portion. Therefore, each of a group of aprons that surrounds its respective base plate can freely be handled independent of the respective balancing means, which greatly facilitates maintenance of the balancing means. In Figure 10, the apron encloses the driving roller R and the sliding base B, including the balancing means AT mounted on the base plate F, which is integrally secured to the frame GR. Figure 11 shows the tension slider TS to the end of which the guide roller M is secured. In an arrangement of spring latch on the spring plate S, an additional latch SLP is provided, as shown in Figure 12, opposite to and symmetrical with respect to the spring latch SLM, for limiting the distance of displacement of the device in the direction of Y-Y' axis during the period of normal operation. An experiment was performed with this arrangement, in an attempt to remove the major cause of apron breakage and, as a result, a significant effect has become apparent therefrom. Further, as shown in Figure 13, latching operation may be performed, in the similar manner as above said by mounting the latch spring SL to the sliding base B and utilizing a hook portion 16 at the tip of the latch spring SL, instead of use of spring plate. WHAT WE CLAIM IS:

1. A tensioning and guiding device for an endless belt or the like, comprising a first

slidable member slidably mounted between opposed guide surfaces on a support member, a second member movably mounted on the first slide member, bias means for biasing the first and second members, in a direction towards said endless belt or the like, latch means for limiting the range of movement of the first slide member between said guide means and stop means for limiting the range and movement of the second member relative to the first slide member, the end of the second member remote from the first slide member having a running surface adapted to bear upon the inner running surface of the endless belt or the like.

2. A device as claimed in Claim I, in which the second member has a roller at the end remote from the first slide member for engaging the inner running surface of the endless belt or the like.

3. A device as claimed in either of the preceding claims, in which the latch means comprises a bar slidably fitted for movement at right angles to the movement of the first slide member and between said opposed guide surfaces, and with a recess for receiving a latch member fitted between said opposed guide members and mounted for movement with said first slide member relative to the support member.

4. A tensioning and guiding device for an endless belt or the like, substantially as hereinbefore described with reference to, and as shown in Figures 2 to 6, 9 or Figures 7 or 8 or 10 or 11 or 12 or 13 of the accompanying drawings.