Woocommerce: Define quantity in cart

another question regarding woocommerce.

I want to declare the quantity of a product ONLY in the cart page. I defined an input and parsed the value of that inside ‘input_value’ put the value dont make the way into the cart_item it seems.

Thanks in regard fellow devs!

<td class="product-quantity">
    <input type="text" id="item-quantity"></input>
        <?php
            if ( $_product->is_sold_individually() ) {
                $product_quantity = sprintf( '1 <input type="hidden" name="cart[%s][qty]" value="1" />', $cart_item_key );
            } else {
                $product_quantity = woocommerce_quantity_input( array(
                    'input_name'  => "cart[{$cart_item_key}][qty]",
                    //'input_value' => $cart_item['quantity'],
                    'input_value' => document.getElementById("item-quantity").value,
                    'max_value'   => $_product->backorders_allowed() ? '' : $_product->get_stock_quantity(),
                    'min_value'   => '0'
                ), $_product, false );
            }   

            //echo apply_filters( 'woocommerce_cart_item_quantity', $product_quantity, $cart_item_key, $cart_item );
        ?>
    </td>