BACKGROUND CONNECTOR BACKGROUND OF THE INVENTION The invention relates to suspended ceiling construction and in particular to an improved connector structure for grid members for suspended ceilings. PREVIOUS TECHNIQUE Suspended ceiling metal grid structures typically involve a structure of longitudinal and transverse sliding slides in the general inverted T shape. Conventionally, the transverse slides are provided with the connector structure at their ends. To assemble the grid, these connectors are inserted into holes or slots formed in the main or longitudinal slide frames. An important feature found in certain transverse slide end connectors is the so-called connector-to-connector interlock, which establishes a direct interconnection between end connectors inserted in the same slot from opposite sides of the longitudinal slider. A connector-to-connector interlock can produce a dimensionally more accurate grid and is capable of resisting tensile forces substantially greater than those ordinarily achieved with a connection to the longitudinal slider. In this way, when a high tensile load capacity is important, a connector-to-connector interlock is preferred. A common approach to producing a high-traction connector-to-connector interlock is to create a so-called lance interlock by punching a rigid projection away from the laminar metal material that forms the connector. The lance interlock typically has a generally backward-facing edge that travels laterally from the main plane of the connector and material forwardly at the edge, mostly remaining continuous with the surrounding air of the connector for resistance. As a result, the spear interlock itself essentially does not yield in a lateral direction. The connector is also made with a receiver edge directed backwards, in front of the locking lance edge. The interlocking lance edge of a connector corresponds to the receiving edge of the opposite connector. The connectors are laterally confined by the groove of the longitudinal slider in which they are assembled, in order to keep the projecting locking lance laterally engaged with the receiving edge. A problem may occur during the installation of the second connector in the slot. Since the slot is designed to laterally constrain the connectors, the slot resists the tendency of the second connector to move laterally away from the opposite connector, as the terminal ends meet the projecting interlocking lances and there is a potentially high interference condition between the connectors and slot. The resulting interference for example may involve undesirable slitting or cutting of any smooth coating on the connectors and / or bending of the edges of the slot, particularly when the metal gauge of the slot is relatively thin. These and other occurrences can lead to irregular and / or excessive installation forces that can make the installation work more difficult, frustrating and less precise. SUMMARY OF THE INVENTION The invention provides an improved roof grid connector, which has a connector-to-connector interlock feature, and which avoids an irregular assembly action by reducing or eliminating deflection by required bending, cutting or shearing elements of the grid or connectors. According to the invention, the connector geometry has a zone that is devoid of any material and is positioned to reduce interference with the front portion of the interlocking structure of a similar opposed connector, preferably identical to the one to which it is assembled. In the described embodiment, the interference reducing zone is in the form of a hole or compensation element punched out or otherwise formed in the front portion of the connector. More specifically, the material of the connector forming the compensation element is laterally deformed from a main plane of the connector, allowing it to strengthen an adjacent locking or receiving coupling surface. The reinforcement function of the compensation element area ensures that the connector will produce a connection of high tensile force. The connector structure described includes a first so-called end interlock, allowing it to be assembled in a slot and to be automatically retained there. Furthermore, the connector produces a connection with a high compression force capability between coupling connectors. The compensation element zone described has the effect of delaying the interference induced by connector-to-connector interlock between the pair of connected connectors and the slot in which they are received. Finally, the interference is delayed until the second connector is almost completely inserted into the groove of the transverse slider. This reduces the risk of extraordinary resistance or interference developing between the slot and connector due to a tendency of the connector to bite at the edge of the slot or bend the material forming the slot that may be of special interest, when the material The longitudinal slide is a material of relatively light caliber. The compensation element zone described once the coupling of the relevant surfaces is established, works in the form of a wedge or cam that can disperse the coupling forces over a large area in order to avoid concentrated compressive stresses. The interference reduction zone, represented by the compensation element area described, can produce a surprising reduction in the force required to assemble a pair of connectors and can produce a surprising improvement in the consistency of the required force levels. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a fragmentary perspective view of the ends of an opposite pair of transverse slides, with end connectors and aligned with a receiving slot in a main or longitudinal slider; Figure 2 is a side elevation view of a typical connector illustrated in Figure 1, and an associated portion of its slide; Figure 3 is a front end elevation view of the connector;
Figure 4 is a fragmentary bottom view of the connector; Figure 5 is a fragmentary perspective rear view of the connector; Figure 6 is a fragmentary elevation view of the connector assembled in the respective slot of the main slider as well as an adjacent slot without a connector; and Figure 7 is a view showing a pair of opposed connectors assembled and interlocked with each other in a main slider slot. DESCRIPTION OF THE PREFERRED MODALITY The description of the US patent. No. 5,517,796 here is fully incorporated by reference. Figure 1 illustrates a portion of a main or longitudinal slide 10, and transverse slides 11 forming intersections in a suspension ceiling grid system, in accordance with the present invention. In the illustrated embodiment, all of the slides 10 and 11 are T-beams formed with a central weft 13, a reinforcing bulb 14 on an edge of the weft 13, and panel support flanges extending opposite 16 over the lower edge u opposite of the plot. Ordinarily, the slides 10, 11 are assembled with their longitudinal axes arranged in a horizontal plane and their wefts 13 that lie in vertical planes. It should be understood, however, that according to the broader aspects of the invention, the connecting structure described can be applied to other forms of grid T-beams or beams and that the particular T-beam structure is illustrative of a preferred embodiment of the invention. this invention. It will further be understood that grid T's typically are formed of thin sheet metal that bends to the illustrated cross section. However, according to the invention, the grid T's can be formed in other ways, for example by extrusion or the like. In many grid systems for suspended ceilings, a horizontal set of laterally spaced parallel or sliding main T's is supported from the structure of the construction on the grid by wires or the like and transverse or sliding T's interconnect with the main slides, with two opposite transverse slide ends placed on opposite sides of the main slide at each intersection. However, this invention is also applicable to basket-type mesh grid systems where main and sliding crossways are not provided, strictly speaking. Both types of grating systems, however, provide intersections where a longitudinal slider extends beyond opposite slide ends that interconnect with the longitudinal slider at intersections. Therefore, as used herein, the term "longitudinal slide" is used instead of "main slide" to encompass basket weaving grid systems, main slide and cross slide lattice systems, and other types of systems. of grids the present invention can be incorporated. Typically, the slides of a suspension ceiling grid system are interconnected to form rectangular or square openings limited by flanges 16. With particular reference to Figures 1 and 6, the weft 13 of the longitudinal slider 10 is formed with a connecting aperture 18 and the ends of the two transverse slides 11 are provided with similar and preferably identical connectors 19. In the illustrated embodiment, the connectors 19 are formed of separate elements and are connected to the slots 13 of the slide ends by a type connection. rivet 21 known in the art. Figure 1 illustrates the slides before any connector is installed in the aperture 18. Figure 6 illustrates the condition after the connector 19 of the first slider end is installed in the aperture 18 and is held there by the first slider lock. extreme discussed below. Figure 7 illustrates an intersection completely assembled of two slides 11 and the longitudinal slider 10. A connector 19 is preferably punched from the sheet material of high strength steel. The main surface areas of the connector 19 retain their original planar configuration and represent the plane of the connector body while other areas described below are punched from the original plane. The connector 19 which is normally used in the vertical plane of its slide frame 13, has front end 26 with an irregular, somewhat angular profile. The front end 26 includes a generally vertical nose or leading edge 27, a lower lower bevel 28 and a larger upper bevel 29; the bevels 28, 29 facilitate the insertion of the connector 19 into the slot 18 of the longitudinal slider 10. A lower edge 31, which is in a vertical plane transverse to the plane of the connector, is adapted to buttly confine the weft 13 of the through slide 10. On its upper edge, the connector 19 includes a pair of projections 32, 33 that provide confinement to opposite stop or stop edges 34, 35 directed back and forth, respectively. The trailing edge 34 of the forward projection 32 is horizontally spaced from the lower vertical edge 31 a distance at least as large as the thickness of the weft 13 of the longitudinal slider 10. The leading edge 35 of the rear projection is slightly separated backwards of the lower edge 31, such that with respect to the forward projection 32, it also provides the thickness of the longitudinal slider frame 13. The height of the forward projection 32 on a lower edge 37 of the front end 26, is less than the height of the slot 18, such that the projection 32 does not prevent the insertion of the leading end into the slot. As will be apparent, when the connector 19 is installed, the frame 13 of a longitudinal slide is placed between the front projection 32 on one side and the bottom edge 31 and the rear projection 33 on the other side. An interlocking tongue or flag in the generally U 41 shape is ejected from the plane of the connector 19. The inner profile of the tongue 41 is formed by a D-shaped hole having a straight vertical edge 42 at a predetermined spacing. determined from the leading edge 27, to leave in the front connector area a material surface 45 between them of fixed horizontal width. The surface of the edge 42 is directed backwards. The tongue 41 extends backward and laterally outwardly (over the plane of the drawing of Figure 2) from a baseline or all that generally coincides with the edge of the orifice 42. The free end of the tongue 41, remote from its base adjacent the edge 42, has a lower edge upwardly angled 43 and a downwardly angled elbow line 44, mutually converging towards a vertical backward edge 46. A fin section 47 of the tongue 41, generally toward behind and on the elbow line 44 is bent inwardly to return to the plane of the connector 19. The free edge 46 of the tongue 41 is generally in the same imaginary vertical plane transverse to the connector plane 19, as is the edge rear 34 of the front projection 32. Spaced rearwardly of the locking tab 41 are a pair of opposite directed locking projections 51, 52 formed or passed from the plane of the connector 19 to a side opposite to that from which the tongue is projected. The projections 51, 52 are spaced apart by an hourglass-shaped hole 53. The projections 51, 53 are essentially mirror images of each other, with each having a configuration that loosely resembles three sides of a pyramid. The rearward projection 52 is somewhat larger in its lateral extent of the plane of the connector 19. The edges 56, 57 of the projections 51, 52 formed by the orifice 53 are out of aplomb or level with respect to a vertical line, of such that they form a point or cusp 58, 59 as seen for example in Figure 2 and Figure 4 and in such a way that they present a slight notch with reference to the backward and forward directions from their respective points 58 , 59. The edge surface 56 is generally oriented rearwardly and the edge surface 57 is oriented generally forward. Alternatively, the side projections 51, 52 can be passed from the connector body with slots to form the edges 56, 57 or their equivalents without producing the hole 53. The projections 51, 52 are relatively strong as a result of their structures being continuous with the surrounding parts of the connector except for their respective edges 56, 57. The horizontal spacing between the projection points 58, 59 is convenient, just slightly larger than the horizontal width of the flat 45. As illustrated, the hole 53 has the same elevation as the flat 45. area of compensating element 60 in the flat part 45 forming the front portion of the connector 19, they deform laterally outwardly from the plane of the connector on the same side to which the tongue 41 extends and at the same elevation or vertical location as the projections 51, 52. In the illustrated case, the compensation element area 60 has the shape of a chordal segment of a circle, such that it is larger in the vertical direction at the leading edge 27 that is close to the edge 42. More specifically, the illustrated compensation element area 60 is like a part of a plate or tray, with a section 61 corresponding to the center of the plate and a surrounding section 62 corresponding to a conical lip of the plate. The flat part 45 surrounding the compensation element area 60 and immediately surrounding portions of the front portion of the connector, preferably is continuous and free of holes, slots, notches or similar discontinuities to provide high strength in the flat part. Vertically aligned holes 66 are punched in the rear portion of the connector 19 to allow it to be attached to a slider end 11 in the rivet connections 21. Preferably, the end of each slider 11 is embossed with a shallow cavity 67 having dimensions large enough to receive the rear portion of the connector 19. The lateral depth of the cavity is sufficient to generally make the associated slider 11 laterally centered with the slot 18. The slot 18 that is elongated in the vertical direction, has a profile polygonal with a central plane of symmetry. At its upper and lower ends, the slot 18 has short ends or sides 71, 72, respectively. The spacing of the edges 70 and 82 respectively at each end of the slot 18 is provided to closely confine the thickness of the sheet material of two connectors 19. A middle section 74 represents the greater width area of the slot 18. While the slot illustrated 18 has its profile formed as a polygon, equivalent arched segments can be used to achieve the desired results. A first slide 11 is connected to a longitudinal slider 10 by inserting the front end 26 of its connector 19 into a selected slot 18 ideally with a snapping motion, essentially limited to translation on the longitudinal or horizontal axis of the slider 11. The connector 19 is pushed into the slot 18, until the leading edge 35 of the rear projection 33 abuts the frame 13 immediately on the slot end 71. During this movement, the tongue or flag 41 bears against the side of the frame. slot 18 in the middle section 74 and by the leverage action is compressed towards the main body plane of the connector 19, until it passes completely through the slot 18. At this point, the tongue 41 engages by rapid actuation backwards in its free configuration, emitting a click or audible click, essentially simultaneously with the support of the projection edge 35 against the longitudinal slider weft 13. The audible click helps the installer in evaluating that connector 19 has been completely installed. This condition is illustrated in Figure 6. As illustrated in Figure 6, the slot 18 and the tongue 41 are configured such that regardless of the lateral position of the first connector 19 in the slot, the vertical free edge 46 of the tab is laterally outside at least portions of the slot, such that the connector 19 is locked or trapped in the frame 13 of the longitudinal slider 10, because the tab 41 under ordinary axial forces can not simply move axially backward of the slot. A second slide 11 is connected to the longitudinal slide 10, when inserting its connector 19 into the slot 18 occupied by the first connector 19. In the illustrated design, the second connector 19 is inserted into the slot 18 to the left of the first connector 19 (when viewed from a reference point associated with the main part of this second slide installed). Again, this installation is ideally achieved by a nesting movement parallel to the longitudinal or horizontal axis of the installed slide. In addition to interlocking the associated tab 41 through the slot 18 (with an audible click) the assembly movement of the second connector 19 produces a connector-to-connector interlock sometimes referred to as "hand greetings". This condition is illustrated in Figure 7, where it can be seen that upon complete assembly of both connectors 19 in a slot 18 (with its stop edges 35 bordering or abutting the faces of the frame 13), the flat part 45 of a connector 19 is received and interlocked between the projections 51, 52 of the other connector and vice versa. When the second connector 19 is inserted into the slot 18, the lateral displacement of the compensation element area 60, allows the front portions of each of the connectors to avoid interference with the forward projection 51 of the opposite connector. It is only when the back of the compensation element area 60 formed by the conical wall 62 engages the projection 51 of the opposite connector 19, that any significant interference develops between the connectors and the slot. The compensation element area 60 is provided in its vertical and lateral extension such that interference coupling with the opposite projection 51 does not occur until the second connector is almost completely received in the slot 18. The lateral angular orientation of the part The peripheral conical 62 of the compensation element area 60 is similar to and complementary to the lateral angular configuration of the projection 51. As a result, the conical or angled portion 62 works like a cam when engaged and is finally fully forced onto the projection 51 upon completion of the installation of the second connector in the slot 18. It will be understood that the front end of each of the connectors resiliently bends laterally away from the opposite connector, to allow interference developed by the projection 51. Once the rear edge of the flat part 45, represented by the edge 42, releases the projection point 58 of the pro 51, the flat part 45 engages by rapid actuation in the space between the set of projections 51, 52 of the opposite connector. The lateral extent of the rear projection 52 at its projection point 59 is at least as large as the displacement of the edge 27 at the vertical center of the compensation element area 60. This geometry ensures that the rear projection 52 serves to interlock the connectors in its assembled position against compression forces on the longitudinal direction of the respective slides 11. A study of Figure 6 reveals that when the contact between a rib 63 and the adjacent vertical slot edge is established, the connector 19 is laterally confined. In this way, when the two connectors 19 are assembled in the same slot 18, significant lateral movement is prevented and the connectors are kept laterally adjusted to each other and a precisely controlled module length is achieved through a ceiling grid. This confinement ensures that the flat parts 45 are maintained in the space between production pairs 51 and 52 for reliable connection. As previously discussed, the width of the flat portions 45 in the longitudinal direction of the slide 11 is only slightly smaller than the space between the points or cusps 58, 59 of the projections, such that the connectors 19 and their associated slides 11 are placed precisely among themselves. On each side of the longitudinal slide frame 13, a flat part 45 is restricted in tension and compression by the adjacent projections 51, 52. A high level of exceptional restraining force is achieved by the notch provided by the receding or non-vertical edges 56, 57. This force of High restriction results from the tongue and groove configuration, provided by the flat part 45 and the projections 51, 52, respectively. In particular, the flat part 45 acts as a tongue under a generally axial force between joined connectors extending in a generally vertical groove or notch, laterally underlying each of the projection points 58 or 59 resulting from angularity or outward orientation. of aplomb of the edges 56, 57. By extending into this groove or recess, the flat portion and adjacent portions of the connector are positively clamped and prevent them from bending laterally out of butt confinement contact with the opposite connector. It will be understood that each of the slides 11 ordinarily has a connector 19 identical to that described herein at the opposite end to that shown in the Figures. A connector 19 can be released or removed from the slot 18 by conveniently twisting the longitudinal slider 10 and manipulating the transverse slider to be released as described in U.S. Pat. No. 5,517,796 previously mentioned. It has been found that a compensation element area such as the described area 60 achieves a surprising reduction in the force required to insert the second connector into a slot and additionally achieves a surprising reduction in the variation of the required installation force. The compensation element area described 60, particularly with its angular portion 62, avoids any tendency for the leading edge 27 to engage the projection 51 and any coating thereon. Additionally, the compensation element area 60 retards any significant interference between the front portion or flat portion 45 of the connector and the opposite projection 51 of the opposite connector, until the second connector is almost completely received in the slot 18, such that there is little tendency for the longitudinal slider material surrounding the slot to be deformed or grooved such as by the beveled surface 29. As illustrated, the area of compensating element 60 is at least sufficiently large in the vertical and lateral direction, for avoid the front part of the projection 51 of the opposite connector. It should be evident that this description is by way of example and that various changes can be made by adding modify or delete details without departing from the just scope of the teaching contained in this description. For example with a slider made of appropriate material, the connector can be integrally formed with the slider web. The invention is therefore not limited to particular details of this description except an extension that the following claims are necessarily so limited.