Applicator for soft materials

In an applicator for dispensing a moldable soft material, comprising an elongated cartridge having a first end, a second end and a longitudinal through bore adapted to receive a charge of moldable soft material and having threads along a portion thereof inward from said second end;

• a cap threadably removable from said first end of said cartridge;
• an elongated body having a first open end, a second closed end and a longitudinal bore therebetween, said first open end adapted to receive said second end of said cartridge in relative rotational attachment, said cartridge and said body adapted for relative rotation about a common longitudinal axis;
• an elongated rod having a first end insertable into the bore of said cartridge from said second end of said cartridge and a second end extending from said second end of said cartridge into the bore of said body, said rod having threads cooperating with said threads within said cartridge bore and means at said second end of said rod cooperating with said bore of said body to cause said rod to rotate and move linearly in response to rotation of said body;
• the improvement comprising:
• said rod comprising a flared head at said first end, a reduced diameter mid-section, and a rear section adjacent said second end, said threads on said rod being limited to and covering less than the full length of said rear section from said cooperating means forward a distance of from 1/2 to 7/8 the length of said rear section, and resilient means within the bore of said body between the second end of said rod and the closed end of said body, said threads on said rod extending over only a portion of the length of said rod such that said threads will disengage from the threads of said cartridge bore when said rod is moved linearly into said body before the second end of said rod fully compresses said resilient means;
• whereby, rotation of said body in one direction advances said rod into said cartridge and rotation in an opposite direction retracts said rod from said cartridge into said body, whereby continued retraction of said rod into said body causes said second end of said rod to contact and compress said resilient means, said resilient means absorbing the linear force of retraction, and whereby the threads on said rod are of a length to disengage from the threads in the bore of said cartridge before said resilient means is fully compressed, the stored energy in said compressed resilient means tending to urge said rod forward to reestablish engagement of said threads.

In an applicator for dispensing a moldable soft material, comprising an elongated cartridge having a first end, a second end and a longitudinal through bore adapted to receive a charge of moldable soft material and having threads along a portion thereof inward from said second end;

• a cap threadably removable from said first end of said cartridge;
• an elongated body having a first open end, a second closed end and a longitudinal bore therebetween, said first open end adapted to receive said second end of said cartridge in relative rotational attachment, said cartridge and said body adapted for relative rotation about a common longitudinal axis;
• an elongated rod having a first end insertable into the bore of said cartridge from said second end of said cartridge and a second end extending from said second end of said cartridge into the bore of said body, said rod having threads cooperating with said threads within said cartridge bore and means at said second end cooperating with said bore of said body to cause said rod to rotate and move linearly in response to rotation of said body;
• the improvement comprising:
• a tension resilient means within the bore of said body between the second end of said cartridge and the second end of said rod and attached thereto, said resilient means being coaxial with and enclosing said rod within said body, and the threads on said rod extending over only a portion of the length of said rod such that said threads disengage from the threads of said cartridge bore when said rod is moved linearly into said body before said resilient means is placed under full tension and before the second end of said rod contacts the closed end of said body;
• whereby, rotation of said body in one direction advances said rod into said cartridge and rotation in an opposite direction retracts said rod from said cartridge into said body, such that continued retraction of said rod into said body places tension on said resilient means, said means absorbing the linear force of retraction, and whereby the threads on said rod are of a length to disengage from the threads in the bore of said cartridge before said resilient means is fully tensed and before said rod contacts the closed end of said body, the stored energy in said tensed resilient means tending to urge said rod forward to reestablish engagement of said threads.