Clip for fixing male and female parts of ground glass joints

The invention serves to hold together the male and the female parts of ground glass joints. As can be seen from the FIGS. 1,2 and 3 this new device consists of two rings (1+2) concentrically placed one above the other. Both rings are connected on their outside by three bow-shaped retainers (5). The two rings (1+2) have one opening (3,4) each on one side. These allow the rings to be slid onto the male and female parts of a glass joint. Both rings then firmly grip the two parts of the joint and hold them together.

This invention refers to a device in the form of clips for holding together 
the male and female parts of ground glass joints. These clips consist of 2 
rings (1+2) concentrically placed one above the other and connected on the 
outside by 3 bow-shaped side-pieces (5). Both rings have one opening on 
one side. 
Devices for the connection of male and female parts of ground glass joints 
already exist. More than 26 years ago small spirals of steel wire were 
fixed on little glass hooks of the male and female parts in order to hold 
the joints together. However these glass hooks often broke and then it was 
impossible to hold the two parts of the joints together. More recently 
steel wire clips have been used. These have the disadvantage that they 
scratch the glass and can easily be bent out of shape. In addition it is 
difficult to apply them to the joints and to remove them. 
The submitted device according to claims 1 to 9 does not have the above 
mentioned disadvantages. Both rings are made of plastic material. They do 
not have any sharp edges which might scratch the glass. Furthermore they 
have a degree of elasticity but cannot be bent out of shape. These 
invented devices can be easily put onto the glass joint with only one hand 
and then they hold the two parts of the glass joints firmly together. The 
clips can easily be withdrawn from the joints with only one hand.

According to FIG. 1 the upper ring (1) has an opening (3) for inserting the 
male part of the glass joint. This opening covers preferably 1/3 of the 
periphery of the ring. Inside each of the rings cams (6) and grooves (7) 
are provided, thereby decreasing the contact area of the ring with the 
heated surface of the glass joints and thereby reducing effectively 
heating and possible softening of the thermoplastic material. The heat, 
radiating from the heated glass, as well as the hot air can pass through 
the grooves (7) thereby providing air circulation around this area which 
hinders overheating of this area. Additionally flexibility of the ring is 
increased by the grooves thereby resulting in easy handling of the device 
in use. 
As material any plastic material can be used, which has sufficient high 
temperature stability, preferably in the range of 150.degree. C. and which 
has as well high modulus of elasticity. Preferred material are 
polyoxymethylen (POM), polyamide (PA), polycarbonate (PC), polyester 
(PBTP, PETP), polyphenylenoxid (PPO), polysulfone and polyetherimide. 
Especially preferred are polyoxymethylen, for example "delrin", trademark 
for corresponding product of Dupont with melting point of about 
175.degree. C., since this product provides the extraordinarily good 
combination of temperature stability and elasticity which is needed with 
respect to the device according to the invention. 
Upper ring (1) and lower ring (2) are connected by bow-shaped side-pieces 
(5); preferably three bow-shaped side-pieces (5) are formed to connect the 
upper ring (1) and the lower ring (2); preferably three bow-shaped 
side-pieces (5) are formed and distributed regularily over an angular area 
of about 120.degree.. 
In order to put the clip onto the glass joints one holds the middle curved 
retainer (5) with two fingers and pushes the two rings (1+2) with their 
opening in front onto the glass joint. The small ring (1) must grip the 
upper male part and the larger ring (2) the lower female part of the 
joint. When the clip is pushed onto the joint, the openings (3+4) between 
the two ends of each ring are somewhat widened due to the elasticity of 
the device. In the final position both rings of the clip tightly span 
around the male and the female parts of the joint and hold them together.