US3015860A

US3015860A - Load arm for pressure rollers of draw frames

Info

Publication number: US3015860A
Application number: US771800A
Authority: US
Inventors: Stahlecker Fritz
Original assignee: Wilhelm Stahlecker GmbH
Current assignee: Wilhelm Stahlecker GmbH
Priority date: 1957-11-05
Filing date: 1958-11-04
Publication date: 1962-01-09
Anticipated expiration: 1979-01-09
Also published as: FR1206521A

Description

INVENTOR FRITZ STAHLECKER LOAD ARM FOR PRESSURE ROLLERS OF DRAW FRAMES Jan. 9, 1962 ATTORNEYS 7 M W W W United States Patent 3,015,860 LOAD ARM FOR PRESSURE ROLLERS O DRAW FRAMES Fritz Stahlecker, Bad Uberkingen, Wurttemberg, Germany, assignor to Wilhelm Stahlecker G.m.b.H., Reichenbach im Tale, Germany Filed Nov. 4, 1958, Ser. No. 771,800 Claims priority, application Germany Nov. 5, 1957 9 Claims. (Cl. 19--135) The present invention relates to improvements in draw frames of spinning machines, and more particularly to a guide and load armfor depressing the spring-loaded pressure rollers of a draw frame which are guided within such a load arm so as to extend parallel to the axes of the lower rollers and to be movable in a direction substantially vertical to the drawing plane. a

For unlocking such a load arm, it is usually necessary to depress this arm slightly at its front end. Since the pressure rollers of modern draw frames are often subjected to considerable loads, such operation of depressing the front end of the load arm for releasing the same so as to permit the arm to be pivoted upwardly requires considerable strength.

It is an object of the present invention to provide a very simple and inexpensive means for supporting the load arm in the operative position and for easily releasing it from such position to permit it to be pivoted upwardly. For this purpose, the present invention provides the load arm with an additional arm which may be mounted on 3,015,860 Patented Jan. 9, 1962 ICC FIGURE 5 shows a cross section taken along line V-V in FIGURE 4; while FIGURE 6 shows a spring means for retaining the releasearm of FIGURE 3 in retracted position.

Referring to the drawings, and first particularly to FIGURES 1 and 2, the guide and load arm 1 has a plurality of guide members 2 adjustably secured thereto by bolts 3 which when loosened are slidable in slots 4. Pressure rollers 5 of the draw frame which are made in the form of twin rollers are guided by means of brackets 6 on guide members 2 and are capable of moving between these brackets 6 in a direction substantially vertical to the drawing plane and parallel to the lower rollers 7. The guide and load arm 1 is mounted in a known manner on a shaft 8 so as to be pivotable in an upward direction. When arm 1 is thus pivoted, the pressure rollers 5 are held withinguide members 2 by means of locking springs 9.

According to the present invention, the load arm- 1 further carries a load-release arm 10 which is pivotably mounted thereon. When in the operative position, release arm 10 will be pivoted backward and rest on load arm 1. For relieving the load on arm 1, the release arm 10 will be pivoted forward about a bolt 11 on load arm 1 so as to be in a position 10', as indicated in FIGURE 1 in dotted lines, whereby the leverage for depressing load arm 1 will be considerably increased. The operator of the loadarm so as to be either pivotable or slidable thereon and to be thus extensible relative to the load arm to increase the leverage of the latter. I

A feature of the invention consists in making the loadrelease arm of a U-shaped cross section. According to one preferred embodiment of the invention such U- shaped arm may be pivotably mounted at one end on the load arm so that, when the latter is in its operative position, the release arm will closely engage with and embrace the load arm. According to another preferred embodiment of the invention, the U-shaped release arm may form a slide member which embraces the side walls of the correspondingly U-shaped guide and lo'ad'arm and is slidable forwardly along the same to extend the leverage of the load arm. For limiting the extent of the movement of the release arm, the same may be provided with suitable stops which may, for example, consist of the heads of the bolts by which the guide brackets of the pressure rollers are mountedon the load arm and which engage in elongated slots in the release arm and are adapted to abut against the respective end walls of the slots when the release arm is pulled out or retracted.

These and other objects, features, and advantages of the present invention will be more apparent from the following detailed description thereof, particularly when read with reference to the accompanying drawings, in

which- FIGURE 1 shows a load arm according to the present invention in which the central and last pressure rollers which are supported in guide brackets are loaded by a common torsion spring, while the starting roller is loaded separately by another torsion spring;

FIGURE 2 shows a cross section taken along line lIII of FIGURE 1;

FIGURE 3 shows a modification of the load arm acthe spinning machine may then depress load arm 1 by acting upon the end of the extended release arm 10. In the embodiment of the invention as shown in FIGURE 1, release arm' 10 is made of a U-shape so as to engage closely with load arm 1 when pivoted to its rear or rest position. This has the advantage that the release arm 10 thus has an adequate bending resistance without increasing the thickness of load arm 1 since it does not extend above the heads of bolts 3 of guide members 2 of the pressure rollers 5.

The arm 10, especially if made of a U-shaped cross section, may, however, also be designed in the form of a slide member which is guided along the side arms of the correspondingly U-shaped load and guide arm 1 by means of corrugations or guide bolts so as to be extensirelease arm in the form of a slide member 12 of a cording to the invention, in which the release arm forms U-shaped cross section in the retracted or rest position on load arm 1, while FIGURE 4 shows slide member 12 in the extended position. On its upper surface, slide member 12 is provided with two

longitudinal slots

13 and 14 in which the heads of bolts 3 slid'ably engage which secure guide members 2 of the pressure rollers 5 (see FIGURE 1) to load arm 1. The forward movement of slide member 12 is limited by the rear end of slot 14 which engages with the head of the mounting bolt 3 of guide member 2 of the central pressure roller. The rear end of load arm 1 is preferably provided with a tension spring 16 which releasably engages an indented portion 17 of the rear end of releasearm 12 for normally retaining the same in the retracted or rest position.

Theembodiment of the invention according to FIG- URES 3 to 5 has the additional advantage that, when the release arm 12 is in the retracted or rest position for the normal operation of load arm 1, it may also serve to increase the bending strength of load arm 1. For this purpose and for a more secure connection of release arm 12 'on load arm 1, the free ends of the side walls of the U-shaped release arm 12 may be bent inwardly to engage underneath the lower edge of load arm 1, as indicated particularly at 15 in FIGURE 5. This embracing portion 15 may be made either of a narrow width as shown in FIGURES 3 and 4 or it may serve as a bracing member along a part or the entire length of load arm 1. Obviously, the release arm 10 according to the embodiment shown in FIGURE 1 may also be secured on load arm 1 when in the unpivo-ted position as shown in full lines so as to serve as an additional reinforcement of load arm 1 during the operation of the draw frame.

Although the invention has been illustrated and described with reference to the preferred embodiments thereof, it should be 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 claims.

The invention having been fully disclosed, that which is claimed is:

1. In a draw frame for spinning machines having parallel upper and lower pressure rollers, means for mounting said upper pressure roller-s so as to be adjustable in a substantially vertical direction relative to said lower pressure rollers, said means comprising a load arm, said upper pressure rollers being rotatably mounted on said load arm, means for mounting said load arm so as to be pivotable together with said upper pressure rollers relative to said lower pressure rollers, means for locking said load arm in the downward position, and means for releasing said load arm from its looked position, said last means including a second arm secured to said load arm but so as to be extensible therefrom to increase the leverage of said load arm, said second arm having a rest position on said load arm and comprising means embracing said load arm when said second arm is in said rest position.

2. A draw frame as defined in claim 1, wherein said second arm is pivotably mounted at one end on said load arm.

3. A draw frame as defined in claim 1, wherein said second arm is of an inverted U-shaped cross section and pivot-ably mounted at one end on said load arm so as to engage closely with and partly embrace said load arm when pivoted upon the same.

4. In a draw frame for spinning machines having parallel upper and lower pressure rollers, means for mounting said upper pressure rollers so as tobe adjustable in a substantially vertical direction relative to said lower pressure rollers, said means comprising a load arm, said upper pressure rollers being rotatably mounted on said load arm, means for mounting said load arm so as to be pivotable together with said upper pressure rollers relative to said lower pressure rollers, means for locking said load arm in the downward position, and means for releasing said load arm from its locked position, said last means including a second arm secured to said load arm but so as to be extensible therefrom to increase the leverage of said load arm, said second arm having a rest position on said load arm and comprising means embracing said load arm when said second arm is in rest position, said second arm being of an inverted U-shaped cross section and slidably mounted on said load arm so as to be movable thereon from said rest position to an extended position.

5. A draw frame as defined in claim 4, wherein said pressure rollers are guided within brackets, said bracket being secured to said load arm by bolts, the heads of at least some of said bolts projecting above the upper surface of said load arm, said U-shaped second arm having at least one elongated slot in its upper wall, said projecting bolt heads slidably fitting in said slot, the ends of said slot serving as stops to determine the fully extended and rest positions of said second arm relative to said load arm.

6. A draw frame as defined in claim 4, further comp-rising resilient means for normally maintaining said second arm in the said rest position.

7. In a draw frame for spinning machines having parallel upper and lower pressure rollers, means for mounting said upper pressure rollers so as to be adjustable in a substantially vertical direction relative to said lower pressure rollers, said means comprising a load arm, said upper pressure rollers being rotatably mounted on said load arm, means for mounting said load arm so as to be pivotable together with said upper pressure rollers relative to said lower pressure rollers, means for locking said load arm in the downward position, and means for releasing said load arm from its locked position, said last means including a second arm secured to said load arm but so as to be extensible therefrom to increase the leverage of said load arm, said second arm having a rest position on said load arm and comprising means embracing said load arm when said second arm is in rest position, said second arm being slidably mounted on said load arm.

8. In a draw frame for spinning machines having parallel upper and lower pressure rollers, means for mounting said upper pressure rollers so as to be adjustable in a substantially vertical direction relative to said lower pressure rollers, said means comprising a load arm, said upper pressure rollers being rotatably mounted on said load arm, means for mounting said load arm so as to be pivotable together with said upper pressure rollers relative to said lower pressure rollers, means for locking said load arm in the downward position, and means for releasing said load arm from its locked position, said last means including a second arm secured to said load arm but so as to be extensible therefrom to increase the leverage of said load arm, said second arm having a rest position on said load arm and comprising means embracing said load arm when said second arm is in rest position, means on said second arm for retaining said arm on said load arm at least in said rest position and for also reinforcing said load arm when the latter is in its operative position.

9. In a draw frame for spinning machines having parallel upper and lower pressure rollers, means for mounting said upper pressure rollers so as to be adjustable in a substantially vertical direction relative to said lower pressure rollers, said means comprising a load arm, said upper pressure rollers being rotatably mounted on said load arm, means for mounting said load arm so as to be pivotable together with said upper pressure rollers relative to said lower pressure rollers, means for locking said load arm in the downward position, and means for releasing said load arm from its locked position, said last means including a second arm secured to said load arm but so as to be extensible therefrom to increase the lever-age of said load arm, said second arm having a rest position on said load arm and comprising means embracing said load arm when said second arm is in rest position, said second arm being slidably mounted on said load arm so as to be movable thereon from said rest position to an extended position, said means embracing said load arm constituting means for retaining said arm on said load arm at least in said rest position and for also reinforcing said load arm when the latter is in its operative position, said second arm being of an inverted U-shaped cross section, said side walls of said second arm slidably engaging with the side walls of said load arm,-and inwardly bent extensions at the free lower end portions of said side walls of said second arm slidably engaging with the lower edge portions of said walls of said load arm.

References Cited in the file of this patent UNITED STATES PATENTS