I'm looking at the weak force from a different angle.
Let's start by looking at an example of the strong at work interaction as described in the modern picture of the Standard Model where quarks and leptons are considered elementary (left picture). In this particular example, we consider a proton and neutron which are converted into a neutron and a proton.
In the thirties of the previous century protons and neutrons (and electrons) were considered fundamental (right picture), and Yukawa had developed a theory that described this interaction by an exchange of massive ($E\approx{100}\frac{MeV}{c^2}$), spin 0 particles which he called mesons. When the muon was discovered in 1935 (which had a mass $E=106\frac{MeV}{c^2}$) it was thought that this was the meson involved in the strong force, but the muon turned out to be not involved in the strong force. The pion (as the meson was called) was discovered in 1947 and turned out to be endowed with an electric charge -1, 0, or +1 and has a mass of about $140\frac{Mev}{c^2}$. Later on, when the existence of quarks was established, the force mediated by pions was considered as a residual force that kept the protons and neutrons in an atomic nucleus together. This residual force is small in comparison with the strong color force between the quarks and rearranges the quark contents in the proton and neutron.
Now, why do I tell all this? Well, at first the protons, neutrons, and electrons (and muons) were considered to be fundamental. Thereafter, in the course of time, protons, neutrons, in short, the plethora of hadrons (mesons and baryons), were considered not to be fundamental particles, but to be composed of quarks.
And we can go a step further. Quarks and leptons can be considered as a composite. In the Rishon Model, there are only two (four when their anti-particles are included) truly elementary fermions (more economic it can't get!):
The T-rishon, with an electric charge unit of $\frac{1}{3}$, one unit of color charge, and one unit of hyper color charge.
The V-rishon, with zero electric charge, one unit of anti-color charge, and one unit of hyper color charge.
The associated force mediators are the photon, the gluon, and the hyper gluon (all long-range).
The down-quark $d$: $\overline T \overline V \overline V$
The up-quark $u$: $TTV$
The electron $e$: $\overline T \overline T \overline T$
The (electron)neutrino $\nu_e$: $VVV$
All families of quarks and leptons:
can be considered as excitations of these composed particles.
Note that the quarks get their color because the T- and V-rishons possess opposite color charge units. All quarks and fermions are colorless as far the hyper color charge is concerned (just as all combinations of three or two quarks are colorless). I won't get into more detail about the merits (and difficulties) of the model, but I want you to look at this picture:
This can be compared with the right picture on top (Fig:34). Now the $\pi^+$ has as rishon content:
$TTVTVV$, the u-quark and anti-down quark. Now if closeby a muon-anti-muon pair ($TTT\overline T\overline T\overline T$, expressed in rishons) and a muon-neutrino-anti-muon neutrino ($VVV\overline V\overline V\overline V$, expressed in rishons) appear, the rishons in the $\pi^+$ will annihilate with the anti-rishons in both pairs, leaving $TTTVVV$ (the $W^+$), which happily moves on as a $\mu^+$ ($TTT$) and its accompanying $\nu_{\mu}$ ($VVV$).
So in the light of the Rishon Model, the weak interaction is no force (as is the weak residue force of the strong force between protons and neutrons), but a residue of the compositeness (so not of a force) that only rearranges the rishon content of particles in an interaction. The number of V-, T-, anti-V-, and anti-T rishons must, of course, be the same on both sides of the interaction. In this case, a $TTV$ and $TVV$ are rearranged in a $TTT$ and $VVV$, just as an $uud$ and $udd$ are rearranged in a $udd$ and $uud$ in the first picture (where a force is present though).
