Heddle frame with vibration damper element
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a heddle frame with detachable edge connections between the side supports and the frame staves consisting of hollow profiles, where at each edge joint a projection extending laterally from the side support engages peg-like into a hollow space in the frame stave and is clamped down by means of a screw. 
     2. Description of the Related Art 
     Heddle frames, which are oscillatingly moved in a weaving machine, are as generally known subject to a very high loading due to the continuous reversals of stress. The stress levels increase with the continuously improved weaving machines operating at increased rotational speeds, such that ruptures caused by the high loading occur at the side supports, and specifically below the peg-like projection. For weight reasons, heddle frames are nowadays made preferably of light metal, which type of material has, however, the property that the flexural strength of this material, drawn as curve, decreases steeply over a number of load changes to a certain load change value and then less steeply, but continuously. However, this is not the case with steel after having reached a certain limit value. Thus, in view of the above mentioned continuously decreasing flexural strength curve of light metal the rupture of parts made from such material can happen at any time due to the higher loading. 
     SUMMARY OF THE INVENTION 
     Thus, the present invention has as an object to prevent ruptures of heddle frame material by structural measures. In order to meet this object the heddle frame includes side supports having projections that are received in hollow spaces in frame staves with which the side supports are connected, the projections and the side supports being spaced by vibration damper elements. 
     By a vibration damper element in each edge connection between a side support and the frame stave of the heddle frame the vibrations caused by the frequent load changes are counteracted and the load peaks are no longer transmitted directly from one part to the other part. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Various embodiments of the invention will be explained hereinbelow based on the drawings. There are illustrated in: 
     FIG. 1 and FIG. 2 show side views of two different embodiments of a side support with projection designed broken off; 
     FIG. 3 shows the side support according to FIG. 2 viewed from the left side as shown in FIG. 2; 
     FIG. 4 shows the edge connection of a heddle frame, consisting of the side support in a further embodiment with the frame stave only partially shown; 
     FIG. 5 and FIG. 6 show edge connections with modified embodiments of the side support and a non-planar vibration damper element; 
     FIG. 7 and FIG. 8 are top views of two different forms of the side support with projection. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     At the one narrow side of the side support 1 of which only the upper end portion is illustrated in FIG. 1, a projection 2 is mounted which serves for connecting the side support 1 to a frame stave (not shown), which connection is termed an edge connection. One form of edge connection is illustrated in FIG. 4. The projection 2 serving as part of the connection includes in the FIG. 1 embodiment a planar base part 2a extending in the direction of the longitudinal axis of the side support 1. The purpose of base part 2a is to increase the area over which projection 2 abuts the vibration damper element 3. Damper element 3 is connected in a preferred manner by bonding to the side support 1 and to the projection 2 along mutually adjacent surfaces. The larger this vibration damper element is, the better is the effect to be obtained therewith. Because the vibrations caused by the high revolution operation of the machine are dampened it is possible to avoid in this way ruptures of the side support 1, which have occurred predominantly at the level of the lower edge of the projection 2. Preferably, an elastomer such as rubber or a rubber like material is used as vibration damper element 3. Polyurethane can also be used. The vibration damper material is in the form of a strip having a substantially uniform cross-section and can be mounted by cementing. The projection 2 in FIG. 2 is somewhat shorter in the vertical direction, but the design is otherwise the same as in FIG. whereby the view according to FIG. 3 reveals that the base part 2a is broader than the projection 2 that serve for connection of side support 1 to the frame stave (not shown). 
     FIG. 4 illustrates the connection of a side support 1 with a frame stave 4 of a heddle frame. Frame stave 4 includes a hollow space 5 with which the projection 2 at the side support engages. The connection is effected by a clamping action by means of a clamping screw 6, which is illustrated by its center line only, and which passes obliquely through the frame stave 4, relative to the longitudinal axis of side support 1, and into the chamfered upper edge 7 of the projection 2. At the base part of projection 2 illustrated in FIG. 4 the vibration damper element 3 is not longer than the projection 2, which is received in the hollow space 5 of the frame stave 4. 
     Because, as mentioned initially, the effect attainable is better with a substantially larger area vibration damper element, various embodiments are possible in which a vibration damper element 3 which has a longer total length is arranged between the side support 1 and the projection 2. In such embodiments side support 1 and projection 2 do not have uninterrupted, opposed plane parallel surfaces that are separated by the vibration damper element 3. The side support 1 and the projection 2 are in the examples according to FIG. 5 and 6, in other words, designed to engage with each other so that side support 1 is received in projection 2. In the example according to FIG. 5 a V-shaped groove is defined between support 1 and projection 2, and in the example according to FIG. 6 a U-shaped groove is defined between the limiting surfaces of the side support 1 and the projection 2, in which is positioned the vibration damping element 3. 
     FIG. 7 and 8 illustrate views from above of a side support 1 and the projection 2 connected thereto, wherein projection 2 is narrower than the side support 1 such as to be able to be inserted into the hollow space 5 of the frame stave 4 (see FIGS. 4 and 5). The vibration damper element 3 in FIGS. 7 and 8 has the same width as the side support 1, which can have various profile shapes. The side support 1 acts at the same time as guide, whereby a U-shaped profile shape according to FIG. 7 embraces a guide rail (not shown) or according to FIG. 8 an L-shaped profile shape is received at one side by a guide groove (not shown).