초록 ▼

A dummy plug (20) is formed with only one lip (25) having a wide outer surface (26) with a fine undulated pattern (30) that has repeated projections (31) of short height. The projections (31) are disposed to be tangent to a plane. Inclined surfaces (27) are formed at opposite ends of the outer surf

A dummy plug (20) is formed with only one lip (25) having a wide outer surface (26) with a fine undulated pattern (30) that has repeated projections (31) of short height. The projections (31) are disposed to be tangent to a plane. Inclined surfaces (27) are formed at opposite ends of the outer surface (26). The inclined surface (27) guides the dummy plug (20) centrally into a cavity (11) while the outer surface (26) is compressed uniformly and resiliently over the entire circumference. The outer surface (26) closely contacts the inner surface of the cavity (11) due to a resilient force, thereby sealing the cavity (11). The fine undulated pattern (30) decreases the contact area and hence decreases the frictional resistance. Thus, the dummy plug (20) can be inserted smoothly inserted into the cavity (11) with a smaller force.

대표청구항 ▼

What is claimed is: 1. A seal made of a resilient material and used to hermetically seal a recess in a housing of a watertight connector by being inserted into the recess, the seal having opposite first and second ends, a cross-sectionally small portion adjacent the first end, a cross-sectionally l

What is claimed is: 1. A seal made of a resilient material and used to hermetically seal a recess in a housing of a watertight connector by being inserted into the recess, the seal having opposite first and second ends, a cross-sectionally small portion adjacent the first end, a cross-sectionally large portion extending from the cross-sectionally small portion towards the second end, the cross-sectionally large portion including an outer circumferential surface having an inclined region with a small diameter end in proximity to the cross-sectionally small portion of the seal and a large diameter end farther from the cross-sectionally small portion of the seal, a substantially cylindrical section extending from the inclined section towards the second end of the seal, the substantially cylindrical section being characterized by an array of fine undulations with alternating annular recesses and annular projections, the annular projections being configured so that a plane can be tangent to outer surfaces of the annular projections and so that the outer surfaces can closely contact an inner surface of the recess. 2. The seal of claim 1, wherein the small diameter end of the inclined surface is cross-sectionally smaller than the recess in the housing for facilitating insertion of the seal into the recess. 3. The seal of claim 2, wherein the seal is a substantially solid dummy plug for hermetically sealing a cavity in the housing and having no terminal fitting accommodated therein. 4. The seat of claim 2, wherein the seal is a waterproof resilient plug (70) used to seal an entrance side of a cavity (61F) in the housing (60F), the rubber plug (70) being secured to an end of a wire (W) by a terminal fitting (63F) inserted into the cavity (61F). 5. The seal of claim 2, wherein the seal is a packing (80) to provide hermetic sealing between a pair of housings (60F; 60M) that are connectable by engaging a projecting part (65) and a recessed part (66), the seal (80) being mounted on an outer surface of the projecting part (65) and being resiliently squeezed between an outer surface of the projecting part (65) and the inner surface of the recessed part (66). 6. The seal of claim 1, wherein a radial dimensional difference between the annular projections and the annular recesses is smaller than a radial dimensional difference between the large and small diameter ends of the inclined region. 7. The seal of claim 1, wherein the seal is symmetrical and has inclined surfaces at opposite longitudinal ends of the undulated surface. 8. The seal of claim 1, wherein the cross-sectionally large portion extends over more than about half the longitudinal extension of the seal. 9. The seal of claim 1, wherein the seal is substantially rotationally symmetric about a longitudinal axis. 10. The seal of claim 1, wherein a radial dimensional difference between the annular recesses and the annular projections of the undulations is approximately one-third of a radial dimensional difference between the small and large diameter ends of the inclined region. 11. The seal of claim 1, wherein the cross-sectionally large portion has a length greater than one-fourth of a distance between the first and second ends of the seal. 12. The seal of claim 1, wherein the cross-sectionally large portion has a length greater than one-third of a distance between the first and second ends of the seal. 13. The seal of claim 1, wherein the cross-sectionally large portion has a length greater than two-thirds of a distance between the first and second ends of the seal. 14. The seal of claim 1, wherein the inclined section defines an angle of between about 15�� and 30�� to an axis extending between the first and second ends of the seal. 15. A seal made of a resilient material and used to hermetically seal a recess in a housing of a watertight connector by being inserted into the recess, the seal having opposite first and second ends defining a length for the seal, first and second cross-sectionally small portions adjacent the first and second ends respectively, a cross-sectionally large portion extending continuously from the first cross-sectionally small portion to the second cross-sectionally small portion and defining a length more than about half of the length of the seal, the cross-sectionally large portion including first and second inclined regions adjacent the first and second cross-sectionally small portions respectively, each of the first and second inclined regions having a small diameter end in proximity to the adjacent cross-sectionally small portion of the seal and a large diameter end farther from the respective cross-sectionally small portion of the seal, a substantially cylindrical section extending continuously from the first inclined region to the second inclined region, the substantially cylindrical section being characterized by an array of fine undulations with alternating annular recesses and annular projections, the annular projections being configured so that a plane can be tangent to outer surfaces of the annular projections and so that the outer surfaces of the annular projections can closely contact an inner surface of the recess in the housing, the annular recesses defined by the array of fine undulations each having a diameter that exceeds diameters of the small diameter ends of the inclined regions. 16. The seal of claim 15, wherein a radial dimensional difference between the annular recesses and the annular projections of the undulations is approximately one-third of a radial dimensional difference between the small and large diameter ends of each inclined region. 17. The seal of claim 16, wherein the seal is a substantially solid dummy plug for hermetically sealing a cavity in the housing and having no terminal fitting accommodated therein. 18. The seal of claim 16, wherein the seal is substantially rotationally symmetric about a longitudinal axis. 19. The seal of claim 18, wherein each of the inclined sections defines an angle of between about 15�� and 30�� to an axis extending between the first and second ends of the seal.