A notched or grooved gland is one having a number of notches formed in its outer flange or belt, which is circular. This class are represented by Figs. 992 and 993. These are caused to operate upon the packing by means of the notches into which the end of a hook-spanner is placed when adjustment of the gland is to be effected. Notched glands resemble hexagonal ones in sometimes having stems which are screwed outside to fit the screwed holes of the packing-boxes. The one shown by Fig 992 has a stem of this sort; but the one denoted by Fig. 993 is screwed inside its stem, and the screw therefore fits the outside of the packing-box. A gland of this shape is shown connected with its cylinder-lid in Fig. 995.

The hook-spanners, with which notched glands are adjusted, are represented by Fig. 1002; and in Fig. 1003 a spanner of this shape is shown in position for advancing a gland upon its box.

Notched glands are used in conjunction with packing-bushes which operate like those of other glands. If the gland has the outside of its stem screwed, it requires but one bush, which is situated at the bottom of the box and is of the same shape as the one seen in Fig. 998. But a gland like the one in Fig. 995, requires an additional bush. This is necessary because the screwed hole of the gland is furnished with a flat bottom, which surface communicates the pressure to the packing in the box, and because this flat surface is always outside of the box. Therefore, to apply the pressure to the packing, a bush is put into the hole of the box, the outer end of the busH bearing against the bottom of the hole in the gland, while the inner end of the bush is in the box and squeezing the packing This inner end is therefore dished to properly grip the india-rubber, and acts in about the same manner as the dished end of any other gland.