FIGURE 16 is a view similar to FIGURE 4 depiotiig another  modified  arrangement  for the  groove slee-ze。

FIGURE  17 is  a view  similar to FIGURE  5  depicting a spooling drum  as  assembled  from  tire  sleeve depicted in  FIGURE  16。

FIGURE  18 is  a  sectional  view  taken  on  line 18—18

of  FIGURE  17。

FIGURE i9 is a sectional view taken on line 19—i9 of FIGURE  17。

Referring to the drawings in  detail, reference character 18 generally indicates a substantially cylindrical sleeve preferably of any suitable diameter corresponding to the diameter of  a drum core (not shown)  to be provid•。d   with a couiiterbalanc•»d peripheral grooving。 The outer pe- ripher( of the sleeve lfl is provident with a plurality of circumfer•ntially   parallel   grooves  13 extending through-

becomes a “ma。ster cylinder” which may be utilized for provid'mg a variety of counterbalanced  grooving systems on the core o:I a drum in a manner  as will be  hereinafter set forth。

6 Conventional  Rise  IS roo›•ing  5ystcm

One  type  of'  counterbalanced  grooving  is   common- ly known as the conventional rise system, and is partic- ularly disclosed in FIGURES 1 throup•h 7。 This type of drum   core   grooving    comprises   a   continuous    combined

10 helical  and parallel  groove on  the outer  periphery  of the

core, and th• length of the core is such With respect to the fiiametric size of the grooves that a full  number  of grooves, plus one-half groove are necessary to fill the en- tire  longitudinal  length  thereof。  For  example,  as shown in FIGURES 5 and 6, the length ct: the core beiwee'n the W•i  i flanges  14 and 16 is indicated as A。   The  grooving,

¿generally indicated at 18, extends across the drum be- tween the i1an;;es, but a half groove spacing, shown at 20, remains  between  the  grooving  and  the  drum  flange  16。

20 Of  course,  in per。tions  of  the  circumferential  grooving the

ha1f- OOve spacing 20 will be adjacent the flange 16, whereas in other portions of  'the  circumferential  groov- ing the half-groove spacing 2(I will be adjacent the drum flange 14, as •U1 be hereinaftei- s••t forth。 Arcuate  end inter bars 12 and 24 of any well known  type  are disposed in the half-grooves for facilitating the cable spooling op- eration,  as is  well i:no-an。

The con•/entiona1 rise grooving system ›comprises a parallel  pu-ooved   section  B  extending  around   substantial-

30 ly nalf  the  circumference  or the  drum  core and  in com-

munication with a sccond similar para11e1 section C tiiro'agh a pair of spaced helical portions D and E。 The groOY)ng 18 of the parallel section B extends from the flange 14 aci•osS the drum core to the end filler bar 22, Which is adjacent the flange ›16。 The groovinq• ,18 of the para11e1 section C extends from the 8ange 16 across the drum core to the end filler bar 24, which is adjacent the fiange 14。 Oi course, the helical section D, comeurinat- ing between the parallel sections B and C, is of: necessity provided with one less  groox•e  than  the parallel sections iii order to provide the  cross-over  action  of  tn’e  cable (not show)  duri:ig  the  winding  operation。  However, the helical or cross-over section E contains an equal min- ber of  grooves as th•。parallel sections B  and C。   Thus,  as