\version "2.19.3"

rightPianoII = \relative c'' {
  % Music follows here.
  r4 r8..
  \change Staff = "leftI"
  \acciaccatura cis8
  \change Staff = "rightII"
  <d gis>32
  r2
}

% keep staves alive
empty = { s1 }
rightPianoI = \empty
leftPianoI = \empty
leftPianoII = \empty

pianoIPart = \new PianoStaff \with {
  instrumentName = "Klavier I"
} <<
  \new Staff = "rightI" \rightPianoI
  \new Staff = "leftI" \leftPianoI
>>

pianoIIPart = \new PianoStaff \with {
  instrumentName = "Klavier II"
} <<
  \new Staff = "rightII"
    \rightPianoII

  \new Staff = "leftII"
    { \clef bass \leftPianoII }

>>

\score {
  <<
    \pianoIPart
    \pianoIIPart
  >>
  \layout { 
%{    \context {
      \Voice 
      \remove "Slur_engraver"
    }
    \context {
      \Score
      \consists Slur_engraver
    }
%}
  }
}