US 3580535 A
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United States Patent  Inventor Christoph Naske Froschhausen, Germany 2! Appl. No. 31,583
 Filed Apr. 24, 1970  Patented May 25, 1971  Assignee WIIB-Anbaumobel von Poschinger K.G.
Murnau, Germany  Priority Apr. 24, 1969  Germany  CONNECTING FIXTURE 4 Claims, 7 Drawing Figs.
s2 u.s.c| 248/239, 108/107, 248/224, 287/2092 51 Int.Cl A47g29/02  References Cited UNITED STATES PATENTS 1,871,972 8/1932 Fenstermaker 248/243X 2,104,831 1/1938 Dauskardt 248/243X 3,270,996 9/1966 Churchill et al. 248/224 3,487,446 12/1969 Hero et al. 248/239X FOREIGN PATENTS 157,213 6/1954 Australia 211/134 370,567 4/1932 Great Britain 248/239 Primary Examiner-Roy D. Frazier Assistant Examiner-J. Franklin Foss AttorneyCraig, Antonelli, Stewart & Hill ABSTRACT: A two-piece fixture for connecting two shelf parts or the like at right angles to each other consisting of a headed locking pin projecting from one side of one shelf part, and a cup-shaped slotted element to be mounted in one end of the other shelf part and adapted to be hooked laterally over the headed projecting part of the locking pin and to draw the two shelf parts tightly together. The largest part of the periphery of the cup-shaped element has a double wall, while the remaining part is formed by a single thicker wall which is flat at its outer side and provided with an axially extending slot which has an open end at the open side of the cup. The inner wall surface at least of this single-wall portion is inclined, tapering from the open end of the slot toward its closed end.
Patented May 25, 1971 9 5 I 62 5 I mmnmi, 6 14 CONNECTING FIXTURE The present invention relates to a fixture for connecting two boards, preferably of wood, for example, of a shelf or the like, at right angles to each other, which consists of a cup-shaped element, preferably of plastic, which is adapted to be inserted into a blind-end bore in one board and the outer peripheral surface of which is provided with a flat portion and a slot in this portion, and ofa locking pin or the like which has a shank inserted in and secured to a bore in the other shelf part and a headed end which projects from this other shelf part and has a maximum diameter equal to or smaller than the shank. When the cup-shaped element and the locking pin are clamped together, the projecting head of the pin is located at the hollow inside of this element.
There is a known fixture of this kind in which the inner wall of the cup-shaped element is cylindrical and eccentrically offset relative to the cylindrical outer wall. A second cup-shaped member, preferably of metal is inserted into the outer element and provided with a slot which extends in the peripheral direction. Due to the eccentricity of the inner wall relative to the outer wall of the outer cup-shaped element, the distance between the inner wall and the outer wall increases in the peripheral direction of the slot so that, when the metallic member is turned relative to the outer element, the projecting head of the lockin pin will be tightened against the outer element. The outer wall of the outer element of this known fixture is also provided with axially extending projections of a relatively low height for locking this element in a blind-end bore of the respective shelf part merely by pressing it into this bore.
It is an object of the present invention to provide a connecting fixture of the type as described above which omits entirely the metallic member which previously had to be provided in the outer cup-shaped element, but still permits this cupshaped element not only to be properly secured in one shelf part but also to be tightly clamped to a locking pin which is secured to another shelf part, even if the latter differs slightly from its prescribed thickness.
For attaining this object, the present invention provides a single cup-shaped element which has an inner wall concentric to its outer wall, and is provided with a gap intermediate the inner and outer walls which is open at the bottom side of the cup and closed at the open side of the latter where the inner and outer walls are secured to each other and an outwardly projecting rim is provided. This gap between the two walls extends in the peripheral direction of the cup-shaped element to points near the two sides of the slot which extends in the axial direction of the element through the thicker remaining wall portion, the outer side of which is preferably flattened. The inner wall surface at least of this thicker wall portion at both sides of the slot tapers from the open end of the slot at the open end of the cup toward the closed end of the slot near the bottom of the cup so that this slotted wall portion gradually increases in thickness from the open to the closed end of the slot. Thus, when the end surface of the shelf part containing the cup-shaped element is placed in engagement with the side of the other shelf part from which the locking pin projects and the shelf parts are shifted relative to each other in the direction of the slot through which the locking pin then projects, the head of the locking pin will slide along the tapered inner wall surfaces at both sides of the slot until the two shelf parts are clamped tightly together. Like the known connecting element as previously described, the cup-shaped element according to the invention may be simply pressed into a blindend bore in one shelf part or the like, and it has the advantage that, due to the provision of the gap between its outer and inner walls, it possesses a certain resilience so that, when it is pressed into a blind-end bore of the proper diameter in one shelf part, it will be firmly secured therein. Since the inner wall surfaces at both sides of the slot along which the head of the locking pin slides when the two shelf parts are being connected to each other are tapered from the open end of the slot at the open side of the cup toward the closed end of the slot adjacent to the bottom of the cup, minor deviations from the prescribed thickness of the shelf part carrying the locking pin will also be compensated by the taper of the mentioned wall surfaces.
Instead of merely making the parts of the inner wall surface of the cup-shaped element of a tapering shape along which the head of the locking pin is slidable, it is advisable to make the entire inner wall surface of this element of a conical shape since it may then be more easily manufactured.
The features and advantages of the present invention will become further apparent from the following detailed description thereof which is to be read with reference to the accompanying drawings, in which:
FIG. 1 shows a perspective view of an inverted cup-shaped connecting element according to the invention;
FIG. 2 shows a horizontal section of a vertical shelf part to which a locking pin is secured together with a bottom view of a connecting element according to FIG. I, as seen in the direction of the arrow C in FIG. 3;
FIG. 3 shows a vertical section which is taken along the line A-B in FIG. 2 of the connection between a vertical and a horizontal shelf part by means of the two parts of the fixture according to the invention;
FIG. 4 shows a horizontal section of a vertical shelf part together with a top view of the connecting element according to FIG. 1, as seen in the direction of the arrow D in FIG. 3;
FIG. 5 shows a front view of the connecting element, as seen in the direction of the arrow B in FIG. 3;
FIG. 6 shows a vertical section of a vertical shelf part containing a locking pin consisting of two parts; while FIG. 7 shows a vertical section of a vertical shelf part containing a locking pin which likewise consists of two parts but permits a second horizontal shelf board to be connected thereto.
As illustrated in the drawings, the connecting element 1 according to the invention has a substantially inverted cup shape like other fixtures of this type as previously known and it comprises a conical inner wall 7 which is integrally connected at the open end of the fitting to a substantially cylindrical outer wall 8, an outwardly projecting rim 2 on this open end of the cup, and a bottom 3 on the other end of the inner wall 7. The two walls 7 and 8 are further integrally combined at one lateral side into a single wall the outer side of which is provided with a flat surface 4 and a slot 5 in this surface which extends in the axial direction of the cup and through the thicker single wall portion to the inner surface of the inner wall 7. Slot 5 has an open end at the open end of the cup and a closed, preferably rounded end adjacent to the inner surface of the bottom 3. Since the inner wall 7 tapers in the direction toward the bottom 3, the cross-sectional size of the walls of slot 5 gradually increases from its open end toward its closed end. The inner and outer walls 7 and 8 are separated by a chamber 9 of a substantially U-shaped or horseshoelike cross section which is open at the bottom side of the cup and closed at the open side of the cup adjacent to the rim 2 and terminates in the peripheral direction of the cup at a certain distance from the two walls of slot 5.
The connecting element 1 is to be inserted into a blind-end bore in a horizontal shelf part 10, for example, a wooden shelf board, by being pressed into the same, and due to its chamber 9 its outer wall 8 will then be resiliently compressed so as to lock the connecting element 1 in a fixed position within this bore. If desired, the outer surface of the outer wall 8 may be additionally provided with longitudinally extending riblike serrations II or the like, as shown at one part of the outer wall 8 in FIG. I. These serrations 11 are preferably provided in the form of at least two groups.
This connecting element 1 is operatively associated with a locking pin 13 the shank part of which is to be secured in a bore 16 in a vertical shelf part, for example, another wooden board 12, and has a head 14 at one end which engages upon an outer surface of the shelf part 12, while on its other end it has a stud projecting from the opposite surface of the shelf part 12. This stud has a head 15 of a diameter equal to or smaller than the diameter of the shank of the locking pin 13 in the bore 16 of the shelf part 12. Intermediate this head 15 and the shank of pin 13, the projecting stud has a part 17 ofa reduced diameter of a thickness substantially equal to the width of slot 5 so that, when pin 13 is mounted in the shelf part 12 and the other shelf part containing the fitting l is moved downwardly so that the open end of slot 5 passes over the reduced stud portion 17, the walls of the slots will slide along the stud portion 17, while the head 15 overlaps the inner edges of the slot walls and its inner side adjacent to the reduced stud part 17 engages with the upwardly tapered inner surface of the thicker single wall portion at both sides of slot 5. By means of these tapered inner wall portions directly adjacent to both sides of slot 5 in fitting 1 it is possible to compensate for minor variations in the prescribed thickness of the vertical shelf part 12 and to draw the .end surface of the horizontal shelf part 10 tightly against the side of the vertical shelf part 12.
FIG. 3 illustrates a modification of the locking pin 18, in which the head 14 of the pin as shown in FIG. 1 is provided with a studlike projection 19 which is similar to that on the other end of the pin, as previously described and permits a further shelf part (not shown) similar to the part 10 to be connected to the other side of the shelf part 12 by means of another connecting element 1 which is mounted in this further shelf part in the same manner as previously described.
As illustrated in FIGS. 6 and 7, the locking pin may also consist of two parts. The head of the locking pin 20 according to FIG. 6 may consist of the head of a screw 21 which is screwed into a tapped bore in pin 20, while when a further horizontal shelf part (not shown) is to be connected to the side of the vertical shelf part 12 opposite to the side carrying the shelf part 10, screw 21 may be replaced by another screw 23, as shown in FIG. 7, which is provided with a flange which engages upon the outer side of the shelf part 12, while the head of this screw 23 is adapted to serve the same function as the head 15 for connecting the further horizontal shelf part by means of another connecting element 1 to the vertical shelf part 12.
Although my invention has been illustrated and described with reference to the preferred embodiments thereof, I wish to have it 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.
Having thus fully disclosed my invention, what I claim is:
l. A two-piece fixture for connecting two boards of a shelf or the like at right angles to each other comprising a substantially cup-shaped connecting element adapted to be mounted in a blind-end bore in a first of said boards adjacent to one end thereof and having a substantially round outer wall and a flat part on said wall adapted to abut against one side of the second board, said element further having an inner wall concentric to said outer wall and having a closed bottom at one end and an open other end, said two walls being integrally connected to each other adjacent to said other end of said element and being separated from each other by a chamber having a round substantially U-shaped cross section and an open end outwardly adjacent to said bottom and a closed end adjacent to said connected end of said walls, said chamber terminating in its peripheral direction into a single thicker wall portion having said flat part on its outer side, said wall portion having a central slot extending in the axial direction of said element and having an open end adjacent to the open end of said inner wall and a closed end adjacent to said bottom, at least the inner surface of said thicker wall portion directly adjacent to both walls of said slot being tapered from said open end to said closed end of said slot so that at least adjacent to said slot said wall portion gradually increases in thickness from said open end to said closed end of said slot, said fixture further comprising a locking pin having a shank adapted to be mounted ina transverse bore in said second board, and a thinner stud on one end of and coaxial to said shank and adapted to project from said side of said second board and havmg a head on its free end, said stud having a thickness substantially equal to the width of said slot and being adapted to be inserted into said slot, and said head having a thickness not larger than that of said shank but larger than the width of said slot and being adapted to engage upon said tapered inner surface when said stud in inserted into said slot.
2. A two-piece fixture as defined in claim 1, in which the entire inner wall surface of said element is conical and tapering from said open side of said inner wall to said bottom thereof.
3. A two-piece fixture as defined in claim 1, in which said shank of said locking pin has a tapped bore in its other end and a screw screwed into said bore and having a head adapted to abut against the other side of said second board.
4. A two-piece fixture as defined in claim 1, in which said shank of said locking pin has a tapped bore in its other end, and a screw screwed into said bore and having an annular flange adapted to abut against the other side of said second board, a head on the outer end of said screw, and a shank part intermediate said head and said flange, said shank part and said screw head being adapted to serve the same functions as said stud and its head for connecting another board by means of another cup-shaped connecting element to said other side of said second board.