I'm pretty sure huntertrw is right about Harwood Brothers being the maker of your pipe. The HB in the oval looks very similar if not identical to the logo they used in advertisements dating back at least to the twenties.
Harwood Brothers is pretty obscure. All I can tell you is that it was founded in Liverpool sometime between 1905 and 1911 by two brothers named Edwin Collier Harwood (1875-1929) and Thomas Harwood (1878-1923). They look to be the first of their family to enter the tobacco-related business; certainly their father, another Thomas (1841-1895), was a veterinary surgeon. He had married Maria Collier (1848-1928) in 1871.
In 1891, a few years before his father died, Edwin was listed as a clerk in an insurance office; by 1901 that had changed. Edwin was a dealer in fancy goods (i.e. pipes and related paraphernalia), and by 1911 he and his brother were both listed as tobacconists' sundrymen. I'm not sure when they made the move from importers to manufacturers, but believe it was no later than 1918.
Younger brother Thomas was the first to die, in 1923, while older brother Edwin passed away half a dozen years later. Fortunately for the business they had established Edwin married in 1912, and produced heirs to carry on. Edwin's wife's name was Frances Louise Farr (1882-1980), and they had at least four children together: Stephen Spender (1913-1993), Douglas Stuart (1917-1990), Clifford Collier (1919-1989), and Frances Jean (1922-?).
Of these apparently only Stephen Spender and Douglas Stuart entered the family business. Stephen married Veronica Ashton in 1954, and they had at least three children (Robert, Hazel, and Andrea). Douglas married Barbara Raws in 1949, and they appear to have had only had one children, Laurence.
The business still exists today, but evidently went dormant some time ago. It appears to have been active at least into the fifties. For the last twenty years, however, financials suggest residual assets but no revenue. Laurence is the key shareholder, and controls what's left of Harwood Brothers Ltd.
The company occupied several addresses in Liverpool over the years. Is there an address, or any other printing on the box the pipes are in? It might help narrow the date of manufacture for your pipes.
Best,
Jon