MXPA01003075A - Gripper for strapping machine - Google Patents

Abstract

A strapping machine (10) comprising a frame (14) for supporting the load, a chute (16) positioned on the frame (14) for receiving the strap material (S), a strap supply (18), and a strapping head (12). The strapping head (12) includes a plurality of sealing elements (22) and a gripper (20). The gripper (20) is positioned at an upstream location from the plurality of sealing elements (22). The gripper (20) has a floating element (24) and a stationary element (26). The floating and stationary elements each include base surfaces (30,34). A plurality of teeth (28) extend from one of the floating and stationary elements (24,26) and a plurality of channels (32) is formed in the other of the elements (24,26). The teeth (28) and the channels (32) are configured to secure the strap (S) therebetween when the gripper (20) is actuated, such that when the gripper (20) is actuated, the teeth (28), in conjunction with the channels (32), form substantially centrally located, localized deformations (36) in the strap extending across its width.

Description

FIELD MACHINE CLAMP FIELD OF THE INVENTION The present invention relates to a fastener for a strapping machine. More particularly, the present invention relates to a fastener for use in the head of the felting machine of a strapping machine for steel strip material. BACKGROUND OF THE INVENTION Strapping machines are well known in the art. There are two main types of strapping machines. A type of strapping machine places and tightens a steel strap around a load to group or secure the load to, for example, a pallet. A typical strapping machine includes a support similar to a frame for the machine in general, a working area for, for example, supporting a load, a strapping head, a conduit around which the belt is fed, and one or more dispensers. to supply the strap material to the strapping head. The strapping head pulls the creping material from the jets, and feeds it around the duct until a guide portion of the strap returns to the strapping head. In the strapping head, the guide portion or guiding end is retained and the end portion or end of the strap is retracted and tensioned to provide proper compression on the felted load. The belt is then sealed with itself in an overlapped manner, then the end-end portion is cut off and the load is removed from the machine. Accordingly, the strapping head has several functions. These functions and the general arrangements of the strapping heads are described in U.S. Pat. No. 4,791,968 issued to Pearson, US Pat. No. 4,825,512 issued to Tremper and colleagues, and US Pat. No. 5,097,874 granted to Bobren. These patents, assigned to the assignee of the present invention, are hereby incorporated by reference. Two main functions of the strapping head are to secure the guiding end of the strap when it returns from its travel around the conduit, and to seal the strapping material on itself. The strip material is manufactured from a variety of materials and in a variety of sizes. Size ranges include both the width of the strap and the thickness or gauge of the strap. In known strapping heads, the effectiveness of the fastener, which is that portion of the machine that holds the guide end of the belt while it is tensioned, sealed on itself and cut, depends largely on the width and the caliber of the material of strap. For this purpose, when replacing the strap material, as when a new source of strap material is supplied from a spout, adjustments must often be made to the fastener so that it can provide an appropriate force on the strap for the strapping head to perform appropriately his remaining functions. In some known fasteners, the strap is attached at the edges of the strap. For this purpose, the use of the fastener is almost totally dependent on the width of the strip material. In other fastener arrangements, the fastener is dependent on the gauge of the strap material, and a wedge in the fastener may be necessary to compensate for changes in the gauge of the strap. Regardless of the type of fastener, consideration must be given to the force exerted on the strap, so that the integrity of the strap, such as cutting the strap material during fastening, is not compromised. In addition, attempts have been made to design strapping heads with fastener portions that can be separated from each other, such as in a pivoted frame, so that maintenance work can be performed on the strapping head. However, these design attempts have not been effective in designing an effective strapping head fastener, where the portions can be separated from one another and which can accommodate varying sizes of strip material.

Accordingly, there is a need for a fastener arrangement that can be mounted on a strapping head, that has portions with pivot of easy access to the strapping head, and that can accommodate variable gauges and widths of strapping material. SUMMARY OF THE INVENTION A strapping machine places an associated strap material around an associated load and tapers the strap material around the load. The belt that is used with the machine has a width. The strapping machine includes a frame for supporting the load, a duct placed in the frame for receiving the strap material and orienting the strap material around the load, and a belt supply. A strapping head pulls the supply strap, feeds the strap through the conduit around the load, passes the strap from the conduit around the load, retracts and tapers the strap, and seals the strap on itself. The strapping head includes a plurality of sealing elements and a fastener. The fastener holds and holds the strap material when it is tensioned and sealed on itself. The fastener is placed in an upstream location from the plurality of sealing elements. The fastener has a floating element and a stationary element. The floating and stationary elements each include a base surface. A plurality of teeth extend from one of the floating or stationary member, and a plurality of channels are formed in the other floating or stationary member. In a preferred embodiment, the teeth extend from the stationary element, and the channels are formed in the floating element. More preferably, both the floating and the stationary element are formed with a base portion or surface defining a plane. In a preferred embodiment, the planes of the base surface are parallel to each other and are oriented at an angle of approximately 15 degrees with respect to the path through the strapping head through which the strip material passes. The teeth and channels are configured to ensure between these the strap when the fastener is activated, such that when the fastener is activated, the teeth, in conjunction with the channels, form localized deformations and located essentially in the center of the strap that is It extends across a portion of the width of the strap. More preferably, the sueder assembly includes two teeth and two channels, where each tooth corresponds to a respective channel. The teeth include a fastening face formed at an angle of about 75 degrees (ie, about 15 degrees from the perpendicular to the direction of travel of the strap through the strapping head.) Other features and advantages of the present invention will become apparent from the following detailed description, together with the appended claims BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective view of an exemplary strapping machine incorporating a strapping head in accordance with the principles of the present invention. Figure 2 is a partial cross-sectional view of a strapping head, showing the sealing elements and the fastener mounted on an inlet or upstream side of the sealing elements Figure 3 is a perspective view of a floating fastener element showing the bags or channels formed in the element Figure 4 is a top view of the fastener element float Figure 3. Figure 5 is a cross-sectional view of the floating fastener element, taken along line 5-5 of Figure 4. Figure 6 is a perspective view of the stationary fastener element, illustrating the fastener teeth. . Figure 7 is a side view of the stationary element, illustrating a profile of the clamping teeth. Figures 8a and 8b illustrate a portion of metal strapping material with a seal formed therein, and showing the localized deformation resulting from the use of the present holder, where Figure 8a is a top view of the strapping material, and Figure 8b is a side view of the strap. DETAILED DESCRIPTION OF THE INVENTION Although the present invention is susceptible to various modalities, in the drawings, what is currently considered to be the preferred embodiment will be described and described below, with the understanding that the present description will be considered an example of the present invention, and that it will not limit the present invention to the specific embodiment illustrated. Referring to the figures and in particular to Figure 1, there is shown an exemplary strapping machine 10 having a strapping head 12 which represents the principles of the present invention. The strapping machine 10 includes a frame 14 which may include a work surface (not shown) to support a load to be held or grouped. The strapping machine includes a conduit 16, the strapping head 12 and one or more jets 18 from which the strapping material S is fed to the strapping head 12.

The strapping head 12 is the portion of the machine 10 that extracts strip material S from the jets 18, feeds the strap S around the conduit 16 and accepts a guide end L of the belt S when feeding around the conduit 16. The strapping heads that perform these, as well as other functions, are disclosed in patents No. 4,791,968 granted to Pearson, No. 4,825,512 granted to Tremper and colleagues, and No. 5,097,874 granted to Bobren. As the strapping head 12 feeds the strip material S around the conduit 16, the material that returns to the strapping head 12 and is secured by the sealing head 12 is designated guiding end L, and the portion of strapping material that resides inside the strapping head 12 when the guide end L returns to the head 12 is designated as the rear end portion T. Once the guide end L returns to the strapping head 12, it must be clamped so that the trailing end T can be properly tensioned to group or compress the load. A fastener assembly 20 in accordance with the present invention is placed immediately upstream of the sealing heads or elements 22 on the strapping head 12. Referring now to Figure 2, the fastener assembly 20 is positioned relative to the sealing elements 22. fastener assembly 20 includes a first floating fastener element 24 and a second stationary fastener element 26. The floating fastener element 24 is mounted on a stationary portion of the strapping head 12, while the stationary fastener element 26 is mounted on a movable portion of the securing head. the strapping head 12. The "movable portion" is that portion 12 which has movable sealing elements 22 mounted thereon. As will be understood by those skilled in the in order for the strap S to be sealed, one or more elements must be moved to engage contact with the belt, and therefore the "moving" portions or sealing elements 22. A further, the strapping head 12 can be configured to move by pivoting to, for example, open to allow access to the internal regions of the head 12. The fastening elements 24 and 26 cooperate with each other to secure the guide end L of the strap S inside the strapping head 12 as the belt S is tensioned and sealed on itself. The stationary fastener element 26 is configured to have a plurality of toothed projections 28 extending upwardly from a base surface 30 of the element. The floating fastener element 24 includes a plurality of channels or pockets 32 formed on a base surface 34 that are complementary to the teeth of the stationary portion 28. Referring now to Figures 5 and 7, the channels are formed with a width wc which is greater than the width wt of the teeth 28. In this configuration, the sides 36 of the channels 32 accommodate the belt S when bending or winding between the apex 38 and the sides 40 of the teeth 28, and the bottom 42 and sides 36 of the channels 32. As can be seen in Figure 7, the base surface 30 of the fastening portion 36 defines a plane Pg. Similarly, as can be seen in Figure 5, the base surface 34 of the floating fastener element 24 defines a plane Pf. Referring now to Figure 2, the plane of the floating element Pf is essentially parallel to, and is separate from, the plane of the base of the stationary fastener Ps. These planes Pf and Ps are formed at an angle to a path, indicated as 43, for the guide end L of the belt S as it passes through the strapping head 12. As can be seen in Figure 2, the leading ends 44 and 46 of the floating and stationary fastener elements 24 and 26 define an inlet, indicated as 48 for the guide end L of the belt. This inlet 48 is slightly larger than the distance d between the base planes Pf and PS and therefore provide a "window" for the belt S as the guide end L enters the strapping head 12. The inlet 48 can be formed as sections of arched wall, as indicated at 50, to further facilitate entry of the guide end L. From the inlet 48, the path 43 through the holder 20 tapers and rotates as the strip material S approaches the teeth 28 and the channels Complementary 32. This in turn defines the angle of inclination a of the base surface planes 30 and 34 with respect to the direction of the path 43. Preferably, the angle a is approximately 15 degrees. For this purpose, when the belt is tensioned, it is tensioned in a direction that is inclined at an angle to the base planes 30 and 34. Referring now to Figure 7, a side view of the stationary holding portion is shown. , with an illustration of the direction of the path 43 which is opposite to the direction of the force F of the strip material S when subjected to tension. The teeth 28 of the floating clamping portion are formed in such a way that each includes first and second surfaces 52 and 54. The teeth 28 can be formed essentially identical with one another. When they are placed on the strapping head 12, and with the strap S passing through the fastener 20, the clamping surfaces 52 of the teeth 28 define an angle β of approximately 75 degrees with respect to the direction of the force F. As will be appreciated by connoisseurs of In the art, the present fastener 20 provides several advantages over known fastener arrangements. First, and with reference to Figures 8a and 8b, since the belt S is held at approximately a central location C over the width of the belt S, the fastener 20 is generally insensitive to the width of the belt. That is, the present fastener can be used with strapping material having generally variable widths without the need for adjustments. In addition, and due to the arrangement of the floating fastener 24, the fastener assembly 20 is also generally insensitive to the thickness or gauge of the strapping material S. As such, and unlike the known strapping head fasteners, the present fastener 20 does not require adjustments to work properly with a variety of strapping materials. Another advantage enjoyed by the present fastener 20 is that the deformations, indicated as 56, which are formed on the belt S are well localized and do not apply excessive stresses on the strip material. Many known fasteners locally apply excessive stresses on the belt, particularly at the edges where these fasteners are attached to the belt, resulting in a weakened area of the belt. The present fastener 20 deforms locally, instead of cutting the strap material, and therefore does not compromise the integrity of the belt. In addition, the present configuration, which provides a space or spacing between the teeth 28 and the walls of the channel 32 when the fastener 20 joins the strip material S, together with the centralized and localized deformations 56, minimizes or eliminates the opportunity of cut the strap material during fastening. Accordingly, the integrity or strength of the strap material S is not compromised as a result of the fastener 20 being attached to the strap S. Also, since the fastening location and consequently the deformations 56 extend only over a portion of the strap. belt width S, this also results in a reduction or elimination of the opportunity to compromise the integrity of the belt. From the above it will be noted that numerous modifications and variations can be made without departing from the true spirit and scope of the new concepts of the present invention. It should be understood that no limitation is intended and should not be inferred from the specific modalities illustrated. It is intended that the disclosure cover all the modifications that fall within the scope of the claims by the appended claims.

Claims (10)

1. CLAIMS 1. A strapping machine for placing an associated strapping material around an associated load and tensioning the strapping material around the load, where the strap has a width, and where the strapping machine comprises: a frame for supporting the load; a duct placed on the frame to receive the strip material and orient the strip material around the load; a supply of strap; and a strapping head to remove the supply belt, feeding the belt through the conduit around the load, passing the belt from the conduit around the load, retracting and tensioning the belt and sealing the belt on itself, where the head The strapping machine includes a plurality of sealing elements and a fastener, wherein the fastener is placed at an upstream location from the plurality of sealing elements, where the fastener has a floating element and a stationary element, where the floating and stationary elements include base surfaces , wherein one of the floating and stationary elements has a plurality of teeth extending from the element, and the other of the floating and stationary elements has a plurality of channels formed in the element, where the teeth and channels are configured for secure the strap between these when the fastener is activated, and when the fastener is activated, the teeth, in together with the channels, they form in the belt localized deformations and essentially located in the center that extend through a portion of the width of the belt.
2. 2. The strapping machine according to claim 1, wherein the base surfaces of the floating and stationary elements each define a plane, wherein the planes of the base surfaces are essentially parallel with respect to each other, and are formed to a angle with respect to the direction of travel of the belt through the strapping head.
3. 3. The strapping machine according to claim 1, wherein the teeth extend from the stationary element, and where the channels are formed in the floating element.
4. The strapping machine according to claim 2, wherein the planes of the base surfaces of the floating and stationary elements are formed at an angle of approximately 15 degrees with respect to the direction of travel of the strap by the strapping head.
5. 5. The strapping machine according to claim 4, which includes two teeth and two channels, where each tooth corresponds to its respective channel.
6. The strapping machine according to claim 4, wherein the teeth extend from the stationary member, and wherein the teeth include a clamping face formed at an angle of approximately 75 degrees with respect to the direction of travel of the belt through the strapping head.
7. 7. In a strapping head for use in a strapping machine for positioning and tensioning an associated strap material around a load and sealing the strap material on itself, the strapping head defines a path therethrough, a clamping assembly for attaching a guide end of the strap material comprising: a floating fastener element having a base portion defining a base plane, wherein the floating fastener element has a plurality of channels formed in the base portion; and a stationary fastener element having a base portion defining a base plane, wherein the stationary fastener element has a plurality of teeth formed in the element extending from the base portion, where each of the plurality of teeth corresponds to one of the channels of the floating clamping portion, where the base plane of the stationary clamping portion and the base plane of the floating clamping portion are essentially parallel to each other, and where the planes of the bases are oriented to an angle of approximately 15 with respect to the path by which the strip material passes through the strapping head.
8. 8. The fastener assembly according to claim 7, where the teeth extend from the stationary element, and where the channels are formed in the floating element. The fastener assembly according to claim 7, which includes two teeth and two channels, where each tooth corresponds to a respective channel. The fastener assembly according to claim 7, wherein the teeth include a clamping face at an angle of approximately 75 relative to the path by which the strip material passes the strapping head. SUMMARY OF THE INVENTION A strapping machine for placing an associated strapping material around an associated load and tensioning the strapping material around the load, where the strap has a width, and where the strapping machine comprises a frame for supporting the load, a duct placed on the frame to receive the strip material and orient the strap material around the load, a supply of strap and a strapping head. The strapping head pulls the supply belt, feeds the belt through the duct around the load, passes the belt from the duct around the load, retracts and tightens the belt, and seals the belt on itself. The strapping head includes a plurality of sealing elements and a fastener. The fastener is placed in an upstream location from the plurality of sealing elements. The fastener has a floating element and a stationary element. The floating and stationary elements include base surfaces. One of the floating and stationary elements has a plurality of teeth extending from the element, and the other of the floating and stationary elements has a plurality of channels formed in the element. The teeth and channels are configured to secure the belt between them when the fastener is activated, and when the fastener is activated, the teeth, in conjunction with the channels, form in the belt localized deformations and essentially located in the center extending to through a portion of the belt width.