The present invention relates to a bobbin holder assembly for a ring-spinning machine. The bobbin holder assembly may be of rotating or non-rotating type and are useful for smooth loading and unloading of bobbins in a textile spinning machinery.
Background of the Invention
Ring spinning machines are used to make yam, in the process of yam making. The feed material, which is in the form of roves, prepared in the previous process called roving, is wound on a bobbin. This bobbin with the roves is hung in the ring spinning machines frame creel with the aid of a bobbin holder assembly and these roves are fed to the drafting zone of the ring-spinning machine to make the yam.
Bobbin holder is a device, which helps the roving bobbin to unwind smoothly at a speed corresponding to the feed rate of the roving into the ring-spinning frame. A bobbin holder generally comprises of a head, which houses a bearing and a brake system and the lower portion, the stem, which houses the retainer device for the bobbin tube. Bobbin holders have a latch comprising of an actuator assembly with a pair of levers that holds on to the bobbin once they are fixed and prevent them from falling. Bobbins are hung from the bobbin holder with the help of the latch, which is basically a snap-fit type. When the bobbins are pushed onto the holder, the levers are shrunk inside the holder to allow passage of the bobbin into the stem of the holder. Once the bobbin passes the lever side then immediately the levers protrude out and prevent the bobbins from slipping out of the holder.
Bobbin holders are of two types: one is the rotating bobbin holder and the other being a non-rotating bobbin holder.

Rotating Bobbin Holder
The rotating bobbin holders hold the bobbins in a frame and ensure uniform unwinding of roving to be fed to the drafting system. The rotating bobbin holder is composed of two basic parts, one is the bearing mechanism and the other is the lever actuator mechanism, which ensures smooth unwinding of the roving yam and the other is the latch mechanism, which ensures loading and unloading of the bobbins.
The bearing mechanism is housed in a cover. There is a center screw, which passes through a corresponding hole in the upper part of the cover, a brake shoe, a brake spring, a washer, a nut, a cup, a washer and a special fastener. The washer and special fastener enable the bobbin holder to be fixed on the spinning frame. Inside the cup there is a brake shoe and a brake spring. The brake spring located between the brake shoe on one end and the washer on the other end is compressed enough to apply a brake force on the cover. The function of the spring is to give uniform performance and consistent quality of yam. The size of the spring determines the quality of the yam. Different springs are used to achieve different quality of the yam threads.
The second part of bobbin holder is a latch mechanism that ensures loading and unloading of the bobbin. The latch mechanism present in the stem is composed of a pair of free-swinging levers secured on the actuator by means of a pin. On top of the actuator the bottom clutch is secured by means of a snap fit arrangement. The arrangement is such that the bottom clutch can freely rotate in its position on top of the actuator. Seated on the bottom clutch is a compression spring. A top clutch is placed on the top end of the spring. The top clutch is fixed on the upper part of the stem by means of another pin. At the bottom of the stem the two levers protmde out of the stem with the aid of a dowel pin through the slots in the stem provided for that purpose. Just above the levers is placed a conical slide.

In the initial position before loading the bobbin, the bottom clutch is in its upper most position and the levers are shrunk inside the stem. The bottom clutch is secured in its upper most position by means of specially designed cam profiles provided on the outer surface of the bottom clutch and corresponding inner surface of the stem. The cam profiles are designed in a discontinuous manner. When the bobbin is pushed on the holder the conical slide moves up and pushes the actuator and thereby the bottom clutch. When the teeth on the bottom clutch interface with those of the fixed top clutch a rotational movement of the bottom clutch is initiated. The cam profile on the bottom clutch now moves out of the corresponding cam profile on the stem and it is positioned in the slot between the cam profiles and the stem. This enables the bottom clutch to fall down along with the actuator and the levers. The dowel pin helps to split the levers and make them protrude out of the stem thereby preventing the bobbin from slipping out of the holder.
Non-rotating Bobbin Holders
The Non-rotating bobbin holders are employed for transport system, loading and unloading of bobbins. These non-rotating bobbin holders are placed on the frame adjacent to rotating ones, such that adjacent to every four rotating bobbin holders there is a non-rotating one. The non-rotating bobbin holder has a spare bobbin on it at all times. The main function of the non-rotating is to save time during replacement of the bobbins when the yam gets exhausted.
A non-rotating holder does not contain the bearing mechanism and the brake, as it is not used for rotation. It has only a lever actuator mechanism.
The lever actuator mechanism present in the holder or the stem of the bobbin holder houses the retainer device for the bobbin tube. Bobbin holders have a latch that holds on to the bobbins once they are fixed and prevent them from falling. Bobbins are inserted into the bobbin holder with the help of a system that is basically a snap fit type. When the bobbins are pushed into the holder,

the levers are shrunk inside the holder to allow passage of the bobbin into the stem of the holder. Once the bobbins pass the lever side then immediately the lever protrudes out and prevents the bobbins from slipping out of the holder.
Object of the invention
The main object of the present invention is to provide smooth and trouble free operation of latch that holds on to the bobbin.
Summary of the Invention
The present invention provides a novel bobbin holder assembly to achieve the object of the invention as stated above.
In the convention bobbin holder assembly the latch mechanism houses a compression spring placed in between a top clutch and a bottom clutch such that, during operation, the compression spring is in constant contact with the bottom clutch in order to push the actuator assembly down once the bobbin tube is left free. In this conventional mechanism, the compression spring sits on the bottom clutch, thereby causing friction, resulting from the spring force on the bottom clutch during operation. This friction results in wear and tear of the bottom clutch and also prevents free and easy rotation of the bottom clutch during operation thereby preventing smooth operation of the latches.
In order to avoid the above-mentioned problem, the present invention provides a solution wherein a seater element is provided to pass through the bottom clutch into a modified actuator such that the compression spring is seated between the seater element and the top clutch. This arrangement makes the bottom clutch independent and can rotate freely during locking operation. The compression spring seats on the seater element and will only help to push the modified actuator down once the bobbin tube is left free.

Therefore, the present invention provides a bobbin holder assembly comprising a head assembly, a bearing mechanism and a stem assembly, said stem assembly comprising a modified actuator and a latch mechanism pivoted inside the actuator to hold the bobbin; a conical slide is slidably attached in grooves provided extemal to the stem, said conical slide adapted to assist in the longitudinal movement of the modified actuator; a clutch mechanism having a top clutch and a bottom clutch adapted to engage with the top clutch and a compression spring positioned between the top and bottom clutches; characterized in that, a seater element is provided in the bottom clutch extending through the bottom clutch into the modified actuator such that the compression spring rests in between the top clutch and the seater element thereby rendering the bottom clutch independent and free to rotate without the friction of the compression spring.
Brief Description of the Drawings
The invention is described fully and particularly, without restricting the scope of the invention in any manner, with reference to the accompanying drawings in which:
Figure 1 shows the assembled view of the conventional rotating bobbin holder;
Figure 2 shows the assembled view of the cup and cover assembly of the
conventional bobbin holder;
Figure 3 shows a exploded view of the cup and cover assembly of the
conventional bobbin holder;
Figure 4 shows the assembled view of the stem assembly of the conventional
bobbin holder;
Figure 5 shows the exploded view of the stem assembly of the conventional
bobbin holder;
Figure 6 shows an assembled view of the stem assembly of the present
invention;

Figure 7 shows an exploded view of the actuator assembly of the present
invention;
Figure 8 shows an exploded view of the stem assembly of the present
invention;
Figure 9 shows the modified actuator of the present invention;
Figure 10 shows the seater element according to the present invention;
Figure 11 shows a compression spring of the present invention.
Detailed Description of the invention
Figure 1 shows the sectional view of a conventional assembled bobbin holder assembly of the rotating type. The main components of the bobbin holder assembly will now be explained with reference to figure 1.
The bobbin holder assembly comprises a head assembly, a bearing mechanism (Fig, 2 and Fig. 3) and a stem assembly (Fig. 4 and Fig, 5),
The head assembly comprises a cover (05) provided externally and toward the top end of the actuator assembly (01) said cover comprises: a screw rod (14), which extends outside the top surface of the cover (05), a top bearing cup (06), a bottom-bearing cup (07), a separator (8) to house a plurality of steel balls (19) forming the ball bearing mechanism. The balls (19) sit flush with respect to the top bearing cup (06) and the bottom-bearing cup (07). The screw rod (14) extends outwards through the circular holes present in the top bearing cup (06) and the bottom-bearing cup (07) in the cover (05) as seen in figure 1. A brake spring (22) is mounted on a conical bush seat (10) and is placed on the top of the cover (05) through the extended screw rod (14) as shown in the figure 1. A cup or an outer cap (09) is placed through the screw rod (14) on top of the brake spring (22) such that it compresses said brake spring (22). The cup (09) is fixed using nuts, washers and special fasteners (12, 13, 20, 24, 26) in a known way as shown in figure 1.

As shown in Fig. 4 and Fig. 5, the stem assembly houses an actuator (01). Latches (11) are fitted inside the actuator (01) preferably by latch dowels (16). The stem (02) also houses a compression spring (21) and is placed in compression with the actuator (01) using a clutch arrangement having a top clutch (03) fixed to the bearing assembly using steel pins (18) and a bottom clutch (04) fixed to the top protruding end of the actuator assembly (01). The protrusion (P) in the top of the actuator (01) that fits into the base hole of the bottom clutch (04) is shown in Figure 5. In this conventional arrangement, the compression spring (21) directly rests on the surface of the bottom clutch (04) thereby causing friction during operation and hence preventing smooth operation of the latches (11). A conical slide (15) is attached externally to the stem (02). The conical slide (15) has two opposing projections in its inside surface such that it slides longitudinally on grooves provided in the sides of the stem (02) and its longitudinal movement is arrested after traveling a certain distance by a dowel pin (16) provided at the bottom of the stem (02). The bobbin that contains rove is fixed to the latches (11) and it is de-creeled from thereon.
Figures 6, 7 and 8 are detailed illustrations showing the sectional view of the bobbin holder assembly of the present invention. The reference numerals and the parts mentioned for all figures are consistent throughout the document.
The clutch mechanism enables the synchronous movement of the actuator mechanism by means of the compression spring (21). In the present invention, shown in figures 6, 7, 8 and 9, a seater element (23) is provided in the bottom clutch (04) such that the compression spring (23) rests in between the top clutch (03) and the seater element (23) provided in the bottom clutch (04) thereby rendering the bottom clutch (04) independent and free to rotate without the friction of the compression spring (21).

The seater element (23) is preferably shaped such that is has a tube-like bottom portion (R) that extends through the hole (H) provided in the bottom surface of the bottom clutch (04) into the top opening (U) of the modified actuator (27). The modified actuator (27) has a through hole (T) passing through its Z-axis, which is perpendicular to the axis of the top opening (U), at a pre-set distance from its top end through which a steel pin (17a) is passed into a corresponding hole (S) in the tube section (R) of the seater element (23) to hold the seater element (23) firmly with the modified actuator (27). The top portion (Q) of the seater element (23) is circular, corresponding to the base of the bottom clutch (04) such that the circular top portion (Q) of the seater element (23) aligns with the base of the bottom clutch (04). The seater element (23) is molded such that a further circular protrusion (P) of a diameter smaller than the circular top portion (Q) is made coaxially above the circular top portion such that a stepped circular groove (G) is formed on the top surface of the seater element (23). The compression spring (21) rests directly on this circular groove (G), and not on the bottom clutch (04), and thus transmits force to the modified actuator (27) to push the modified actuator (27) down once the bobbin holder is left free without disturbing the rotation of the bottom clutch (04).
Figure 7 shows the exploded view of the modified actuator assembly as per the present invention. Figure 9 shows the construction of the modified actuator (27) according to the present invention. The top opening (U), the through hole (T) in the Z-axis is clearly shown in this figure. Figure 10 clearly shows the construction of the seater element (23) as explained earlier and Figure 11 shows the construction of the compression spring that is to be positioned between the top clutch (03) and the seater element (23) of the present invention.
It has been observed during the test carried out on the bobbin holder of the present invention that the life of the latch actuator mechanism is considerably increased. There is also no interruption of the latch that holds onto the bobbin.

We Claim:
1. A bobbin holder assembly comprising a head assembly, a bearing
mechanism and a stem assembly, said stem assembly comprising
a modified actuator and a latch mechanism pivoted inside the said modified actuator to hold the rove;
a conical slide is slidably attached in grooves provided external to the stem, said conical slide adapted to assist in the longitudinal movement of the actuator;
a clutch mechanism having a top clutch and a bottom clutch adapted to engage with the top clutch and a compression spring positioned between the top and bottom clutches; characterized in that,
a seater element is provided in the bottom clutch extending through the bottom clutch into the modified actuator such that the compression spring rests in between the top clutch and the seater element thereby rendering the bottom clutch independent and free to rotate without the friction of the compression spring.
2. The bobbin holder assembly as claimed in claim 1, wherein the seater element has a circular top portion and a tube-like bottom portion said circular top portion corresponding to the base of the bottom clutch such that the circular top portion of the seater element aligns with the base of the bottom clutch, said tube-like bottom portion extending through a hole provided in the base of the bottom clutch into a top opening provided in the actuator,
3. The bobbin holder as claimed in claim 2, wherein a circular protrusion with a diameter smaller than the circular top portion is made coaxially above the circular top portion thereby forming a stepped circular groove on the top surface of the seater element such that the compression spring rests directly on this circular groove, and not on the bottom clutch.

4. The bobbin holder assembly as claimed in claim 2, wherein the modified actuator has a through hole perpendicular to the axis of its top opening at a preset distance from the top end of the modified actuator through which a fastener is passed into a corresponding hole in the tube section of the seater element to hold the seater element firmly with the actuator.
5. A ring-spinning machine comprising at least one of the bobbin holder assembly as claimed in any one of the preceding claims.
6. A bobbin holder assembly as described hereinabove with reference to the accompanying figures 6 to 11.
DATED THIS 21st DAY OF AUGUST 2007