diff --git a/CHANGELOG.md b/CHANGELOG.md
index b5a4c060..696569a7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,12 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [3.4.0] - Unreleased
+
+### Added
+
+- box.ASCII_DOUBLE_HEAD
+
 ## [3.3.0] - 2020-07-12
 
 ### Added
diff --git a/rich/box.py b/rich/box.py
index a4cf672d..f21e3b58 100644
--- a/rich/box.py
+++ b/rich/box.py
@@ -174,6 +174,19 @@ ASCII2: Box = Box(
 """
 )
 
+ASCII_DOUBLE_HEAD: Box = Box(
+    """\
++-++
+| ||
++=++
+| ||
++-++
++-++
+| ||
++-++
+"""
+)
+
 SQUARE: Box = Box(
     """\
 ┌─┬┐
@@ -412,6 +425,7 @@ if __name__ == "__main__":  # pragma: no cover
     BOXES = [
         "ASCII",
         "ASCII2",
+        "ASCII_DOUBLE_HEAD",
         "SQUARE",
         "MINIMAL",
         "MINIMAL_HEAVY_HEAD",
diff --git a/rich/table.py b/rich/table.py
index afe3b6de..f951e2f2 100644
--- a/rich/table.py
+++ b/rich/table.py
@@ -294,7 +294,7 @@ class Table(JupyterMixin):
             style (Union[str, Style], optional): Style for the column cells. Defaults to "none".
             justify (JustifyMethod, optional): Alignment for cells. Defaults to "left".
             width (int, optional): A minimum width in characters. Defaults to None.
-            ratio (int, optional): Flexible ratio for the column. Defaults to None.
+            ratio (int, optional): Flexible ratio for the column (requires ``Table.expand`` or ``Table.width``). Defaults to None.
             no_wrap (bool, optional): Set to ``True`` to disable wrapping of this column.
         """
 
@@ -652,13 +652,13 @@ class Table(JupyterMixin):
                 cells.append(lines)
 
             cells[:] = [
-                Segment.set_shape(_cell, width, max_height, style=table_style)
+                _Segment.set_shape(_cell, width, max_height, style=table_style)
                 for width, _cell in zip(widths, cells)
             ]
 
             if _box:
                 if last and show_footer:
-                    yield Segment(
+                    yield _Segment(
                         _box.get_row(widths, "foot", edge=show_edge), border_style
                     )
                     yield new_line